USRE44082E1 - Fuel injector having dual mode capabilities and engine using same - Google Patents

Abstract

A solitary fuel injector for a diesel engine that is capable of injecting fuel for a homogeneous charge compression ignition injection event, a conventional injection event. The solitary fuel injector also has a mixed mode that includes a homogeneous charge compression ignition injection and a conventional injection in a single compression stroke for the engine.

Description

Relation to other patent application

This application claims priority to provisional application No. 60/327,984, filed Oct. 9, 2001, with the same title.

TECHNICAL FIELD

This invention relates generally to nozzle assemblies, and more particularly to fuel injectors having dual mode capabilities.

BACKGROUND ART

In an effort to reduce emissions and to comply with more strict clean air standards, manufacturers of various diesel engine components have begun exploring alternative engine strategies. One such strategy that appears to have promise is the alteration of the manner in which fuel is injected. For instance, in a traditional diesel engine, fuel injection is timed to occur when the cylinder piston is near a top dead center position for its compression stroke. When the fuel and air reach an auto-ignition point, combustion occurs. This can be virtually instantaneous or after some ignition delay.

Engineers have learned that it is possible to reduce engine emissions if a small amount of fuel is injected while the cylinder piston is at the beginning of the compression stroke. In other words, when the piston is closer to a bottom dead center position than the top dead center position for the compression stroke. The injected fuel mixes with the air as it is being compressed to form a relatively homogeneous mixture that combusts when the piston is near its top dead center position. This mode of operation is typically referred to as homogeneous charge compression ignition. Because the fuel mixture is relatively homogeneous when combustion occurs, fewer emissions are produced during this type of injection event than a typical injection event. In other words, uniform air/fuel distribution and associated lower combustion temperatures contribute to significant NO_x, and particulate reductions.

One example of an engine utilizing the homogeneous charge compression ignition is described in U.S. Pat. No. 5,875,743, which issued to Dickey on Mar. 2, 1999 and is entitled Apparatus and Method For Reducing Emissions in a Dual Combustion Mode Diesel Engine. The apparatus disclosed by Dickey includes a port diesel fuel injector that is capable of delivering fuel to an engine cylinder for a homogeneous charge compression ignition injection event in addition to a fuel injector positioned to perform a more traditional injection event. While the fuel injection system of Dickey is capable of reducing emissions, there is still room for improvement.

For instance, engineers have determined that a reduction in the number of engine components can result in a more robust operating system. As indicated, the fuel injection system taught by Dickey includes multiple fuel injectors for the performance of two distinct injection events. However, it should be appreciated that the fuel injection system could be more robust if there was only a single fuel injector which had a limited number of components. In other words, a reduction in the number of fuel injectors, and/or fuel injector components, could make the system more robust because there would be less components that could fail or malfunction. In addition, in contradiction to the teachings of Dickey, engineers have learned that for certain engine load conditions, homogeneous charge compression ignition events may not be desirable.

The present invention is directed to overcoming one or more of the problems set forth above.

DISCLOSURE OF THE INVENTION

In one aspect of the present invention, a nozzle assembly includes a nozzle body that has a centerline and defines a plurality of nozzle outlets. A first portion of the plurality of nozzle outlets are oriented at a first angle with respect to the centerline. A second portion of the plurality of nozzle outlets are oriented at a second angle with respect to the centerline. A needle valve is positioned adjacent the plurality of nozzle outlets.

In another aspect of the present invention, an engine that has at least two modes of operation includes an engine housing defining a plurality of cylinders. A solitary fuel injector is provided for each of the cylinders and each has a tip at least partially positioned in one of the plurality of cylinders. The fuel injector has a first configuration for a homogeneous charge compression ignition mode of operation. The fuel injector has a second configuration for a conventional mode of operation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1a is a schematic representation of an engine according to the present invention;

FIG. 1b is a diagrammatic representation of fuel spray from the HCCI nozzles of the fuel injector ofFIG. 1;

FIG. 1c is a diagrammatic representation of fuel spray from the conventional nozzles of the fuel injector ofFIG. 1;

FIG. 2a is a diagrammatic sectioned side view of a fuel injector according to the present invention;

FIG. 2b is a diagrammatic sectioned side view of the top portion of the fuel injector ofFIG. 2a, illustrating only a first portion of injector fluid lines;

FIG. 2c is a diagrammatic sectioned side view of the top portion of the fuel injector ofFIG. 2a, illustrating only a second portion of injector fluid lines;

FIG. 3 is a diagrammatic sectioned side view of the nozzle portion of the fuel injector ofFIG. 2;

FIG. 4 is a schematic representation of the fuel injector ofFIG. 2;

FIG. 5 is a diagrammatic sectioned side view of an alternative needle valve nozzle portion for use with the fuel injector ofFIG. 2;

FIG. 6 is a schematic representation of a fuel injector according to an alternate embodiment of the present invention;

FIG. 7 is a diagrammatic sectioned side view of a needle valve nozzle portion of the fuel injector ofFIG. 6;

FIG. 8 is a schematic representation of a fuel injector according to an another alternate embodiment of the present invention;

FIG. 9 is a diagrammatic sectioned side view of a nested needle valve nozzle portion of fuel injector ofFIG. 8;

FIG. 10 is a schematic representation of a fuel injector according to yet another embodiment of the present invention;

FIG. 11 is a diagrammatic sectioned side view of a nested needle valve nozzle portion of the fuel injector ofFIG. 10;

FIG. 12 is a diagrammatic sectioned side view of still another needle valve nozzle portion having a dual concentric needle according to the present invention;

FIG. 13 is a schematic representation of a fuel injector including the nozzle portion ofFIG. 12;

FIG. 14 is a schematic representation of another fuel injector including the nozzle portion ofFIG. 12;

FIG. 15 is a schematic representation of yet another fuel injector including the nozzle portion ofFIG. 12;

FIG. 16 is a schematic representation of a fuel injector according to still another embodiment of the present invention;

FIG. 17 is a diagrammatic sectioned side view an alternate actuator portion for use with the fuel injector ofFIG. 16; and

FIGS. 18a-c are diagrammatic sectioned side views of a single needle valve nozzle tip portion for use with the fuel injector ofFIG. 16.

BEST MODE FOR CARRYING OUT THE INVENTION

Referring now toFIG. 1a there is illustrated anengine10 according to the present invention.Engine10 provides alow pressure reservoir12 that preferably includes an amount of engine lubricating oil. However, it should be appreciated that any suitable fluid could be contained therein, such as coolant, transmission fluid or fuel. Ahigh pressure pump13 pumps oil fromlow pressure reservoir12 and delivers the same to high pressure manifold orcommon rail14. High pressure oil flowing out ofhigh pressure manifold14 is delivered via high pressurefluid supply line15 as part of ahydraulic system21 provided inengine10, and oil is returned tolow pressure reservoir12 via lowpressure return line16 after it has performed work inhydraulic system21.Engine10 also has anengine housing11 that defines a plurality ofcylinders25.

Each of thecylinders25 defined byengine housing11 has amovable piston26. Eachpiston26 is movable between a bottom dead center (BDC) position and a top dead center (TDC) position. For a typical fourcycle diesel engine10, the advancing and retracting strokes ofpiston26 correspond to the four stages ofengine10 operation. Whenpiston26 retracts from its top dead center position to its bottom dead center position for the first time, it is undergoing its intake stroke, and air can be drawn intocylinder25 via an intake valve (not shown). Whenpiston26 advances from its bottom dead center position to its top dead center position for the first time it is undergoing its compression stroke and the contents ofcylinder25 are compressed. At an appropriate time during the compression stroke, fuel can be injected intocylinder25 by afuel injector30, and combustion withincylinder25 can occur in a conventional manner. This combustion drivespiston26 downward toward its bottom dead center position, for the power stroke ofpiston26. Finally, whenpiston26 once again advances from its bottom dead center position to its top dead center position, post combustion products remaining incylinder25 can be vented via an exhaust valve (not shown), corresponding to the exhaust stroke ofpiston26. Whileengine10 has been illustrated as a four cycle, four-cylinder engine, it should be appreciated that any desired number of cylinders could be defined byengine housing11. In addition,engine10 could be a two stroke engine or have the ability to operate in both two stroke and four stroke modes.

Returning toengine10, asolitary fuel injector30 is provided for eachcylinder25 and is positioned such that atip portion95 is at least partially positioned incylinder25 as in a typical diesel engine.Fuel injector30 is fluidly connected to afuel tank19 via afuel supply line20 and delivers fuel tocylinder25 for combustion.Fuel injector30 has afuel injector centerline29. Attached tofuel injector30 are a firstelectrical actuator32 and a secondelectrical actuator42. Together, firstelectrical actuator32 and secondelectrical actuator42 control fuel pressurization withinfuel injector30 and the timing of injection events.Activators32 and42 are controlled in their respective energizations by anelectronic control module17 in a conventional manner, via communication line(s)18.

Referring in addition toFIGS. 1b and 1c, there are shown diagrammatic illustrations of fuel spray fromHCCI nozzle outlets126 andconventional nozzle outlets128, respectively. Whilefuel injector30 could be any type of fuel injector, such as a cam actuated or common rail fuel injector, it preferably is a hydraulically actuated fuel injector having at least two modes of operation, and preferably also includes mixed mode capabilities. Therefore,fuel injector30 preferably has a first configuration that allows for fuel spray via a first portion of nozzle outlets that include one or more Homogeneous Charge Compression Ignition (HCCI)nozzle outlets126, and a second configuration that allows for fuel spray via a second portion of nozzle outlets that include one or moreconventional nozzle outlets128. In other words, several components offuel injector30 are moved to, and positioned in, a first arrangement whenfuel injector30 injects fuel viaHCCI nozzle outlets126 and are moved to, and positioned in, a second arrangement whenfuel injector30 injects fuel viaconventional nozzle outlets128. The configurations might also have a dynamic aspect in which certain components move, do not move, or move differently depending on the configuration.

As illustrated inFIG. 1b, injection fromHCCI nozzle outlets126 preferably produces fuel spray intocylinder25 that is directed in a first spray pattern relative tocylinder centerline27 andfuel injector centerline29. The present invention also contemplates instances in whichinjector centerline29 is not co-linear withcylinder centerline27, such as wheninjector30 is at an angle with respect tocylinder centerline27, or wheninjector30 is offset fromcylinder centerline27. Preferably, each of the one ormore nozzle outlets126 is at a first angle θ with respect tocenterlines27 and29. This first angle is preferably relatively small as illustrated inFIG. 1b, such as on the order of less than or equal to 30 degrees but could be oriented directly alongcenterline27. This fuel spray pattern is preferable for a number of reasons. First, becausepiston26 is nearer its bottom dead center position when injection fromHCCI nozzle outlets126 occurs, the entire volume ofcylinder25 can be used to mix the fuel with air incylinder25. Therefore, when combustion occurs aspiston26 approaches the top dead center position of its compression stroke, preferably a homogeneous mixture will have been created which is believed to combust cleaner than a combustion which results from a typical lean heterogeneous diesel fuel injection. In other words, it is believed that the best mixing of fuel and air into a homogeneous charge over a range of engine speeds will be achieved by spraying fuel intocylinder25 in this spray pattern. In addition, because the fuel spray is generally directed downward, as opposed to toward the sides ofcylinder25, wetting of these surfaces can be avoided. This is desirable because contact of the pressurized fuel with the cylinder walls can produce smoke or other undesirable emissions. The present invention also contemplates the injection of fuel at two or more angles, including at conventional angles, during an HCCI injection event.

Referring toFIG. 1c, injection fromconventional nozzle outlets128 preferably produces fuel spray that is directed in a second spray pattern relative tocylinder centerline27 andinjector centerline29. Preferably, each of the one ormore nozzle outlets128 is at a second angle a with respect tocenterlines27 and29. This second angle is preferably relatively large, as illustrated inFIG. 1c, such as on the order of greater than 60 degrees. This fuel spray pattern is preferable becausepiston26 is at or near top dead center position and usable space withincylinder25 is limited in height. Further, because the air withincylinder25 is compressed, injection of pressurized fuel should cause a near instantaneous combustion event, thus avoiding cylinder wetting, which could lead to undesirable emission production.

I.FIGS. 2-4

Referring in addition toFIGS. 2a-c and4, there is shown a sectioned side view offuel injector30 according to the preferred embodiment of the present invention, as well as a schematic representation offuel injector30.Fuel injector30 provides aninjector body31 made up of various components attached to one another in a manner well known in the art, and a number of movable parts positioned as they would be prior to an injection event.Fuel injector30 preferably provides a firstelectrical actuator32 and a secondelectrical actuator42 which control the timing and duration of HCCI injection events via a three-way valve. Preferably,actuator32 is a two-position solenoid that includes a biasingspring33, acoil34 and an armature35 that is attached to avalve member37. Likewise,actuator42 is also preferably a two-position solenoid that includes a biasingspring43, acoil44 and anarmature45 that is attached to avalve member47, which is part of another three-way valve.Valve members37 and47 are preferably poppet valve members, however, it should be appreciated that other suitable valve members, such as spool or ball valve members, could be substituted. Further, while actuators32 and42 are preferably solenoids, it should be appreciated that it could instead be any suitable electrical actuator, such as but not limited to a piezoelectric actuator or a stepper motor.

Referring specifically toFIG. 2b and the injector schematic ofFIG. 4,valve member37 is movable between a low pressure seat38 (as shown) and ahigh pressure seat39. Whensolenoid32 is de-energized,valve member37 is biased toward an advanced position closinglow pressure seat38 by biasingspring33. Whenvalve member37 is in this position, avariable pressure passage67 and apressure communication passage88, both defined byinjector body31, are fluidly connected to ahigh pressure passage51.Passage88 is connected topassage67 via a restricted orifice to slow the opening movement of one of the needle valve members discussed infra. Whensolenoid32 is energized, armature35moves valve member37 upward to closehigh pressure seat39. Whenvalve member37 is in this retracted position,variable pressure passage67 andpressure communication passage88 are fluidly connected to alow pressure passage40.

Referring toFIG. 2c andFIG. 4,valve member47 is movable between alow pressure seat48 and ahigh pressure seat49. When actuator42 is de-energized,valve member47 is biased toward an advanced position closing low pressure seat48 (as shown) by biasingspring43. Whenvalve member47 is in this position, acontrol line77, shown inFIG. 3, which is defined byinjector body31, is fluidly connected to fuel pressure in acontrol supply line76.Control supply line76 is fluidly connected to afuel pressurization chamber85. When asupply check valve87 is seated andvalve member47 is in this downward position, high pressure infuel pressurization chamber85 andcontrol supply line76 prevails incontrol line77. Between injection events, fuel is at low pressure throughoutinjector30. When actuator42 is energized,armature45moves valve member47 upward to closehigh pressure seat49. Whenvalve member47 is in this position,control line77 is fluidly connected to low or medium pressurefuel supply line20.

Returning tofuel injector30 and referring again toFIG. 2b and the schematic ofFIG. 4, aspool valve member55 is also positioned ininjector body31 and is movable between an upward position as shown, and a downward position.Spool valve member55 is biased toward its upward position by a biasingspring60.Spool valve member55 defines ahigh pressure annulus57 that is always open tohigh pressure passage51 via a plurality of radial holes.Passage51 is positioned such that it can open anactuation fluid passage68 tohigh pressure passage51 whenspool valve member55 is in its downward position. Alow pressure annulus58 is also provided onspool valve member55 that connectsactuation fluid passage68 to a lowpressure drain passage52 defined byinjector body31 whenspool valve member55 is in its upward position as shown.Spool valve member55 has a controlhydraulic surface63 that is exposed to fluid pressure in aspool cavity65, and ahigh pressure surface56 that is continuously exposed to high pressure inhigh pressure passage51.Surfaces56 and63 preferably are about equal in effective surface area, but could be different if desired, such as to produce hydraulic biasing in place of biasingspring60.Spool cavity65 is fluidly connected tovariable pressure passage67.

Whenvariable pressure passage67 is fluidly connected tohigh pressure manifold14, such as whenvalve member37 is in its advanced position, pressure withinspool cavity65 is high andspool valve member55 is preferably hydraulically balanced and maintained in its retracted position by biasingspring60. Whenspool valve member55 is in this position,actuation fluid passage68 is blocked from fluid communication withhigh pressure passage51 but fluidly connected tolow pressure passage52 vialow pressure annulus58. Conversely, whenvariable pressure passage67 is fluidly connected tolow pressure reservoir12, such as whenvalve member37 is in its retracted position (activator32 energized), pressure withinspool cavity65 is sufficiently low that the high pressure acting onhigh pressure surface56 can overcome the force of biasingspring60, andspool valve member55 can move to its downward position. Whenspool valve member55 is in this downward position,actuation fluid passage68 is blocked fromlow pressure passage52 but open tohigh pressure passage51 viahigh pressure annulus57.

Returning again tofuel injector30, anintensifier piston80 is movably positioned ininjector body31 and has ahydraulic surface81 that is exposed to fluid pressure inactuation fluid passage68.Piston80 is biased toward a retracted, upward position by a biasingspring84. However, when pressure withinactuation fluid passage68 is sufficiently high, such as when it is open tohigh pressure passage51,piston80 can move to an advanced, downward position against the action of biasingspring84. Aplunger83 is also movably positioned ininjector body31 and moves in a corresponding manner withpiston80. Whenpiston80 is moved toward its advanced position,plunger83 also advances and acts to pressurize fuel within afuel pressurization chamber85. Whenplunger83 is undergoing its retracting stroke, new fuel enterschamber85 via afuel inlet86 past asupply check valve87. Depending on the area ratio ofpiston80 toplunger83, fuel is raised to some multiple of the actuation fluid pressure.Fuel inlet86 is in fluid communication withfuel source19 viafuel supply line20. During an injection event asplunger83 moves toward its downward position,check valve87 is closed andplunger83 can act to compress fuel withinfuel pressurization chamber85. Whenplunger83 is returning to its upward position, fuel is drawn intofuel pressurization chamber85past check valve87.

Apressure relief valve70 is movably positioned ininjector body31 to vent pressure spikes fromactuation fluid passage68. Pressure spikes can be created whenpiston80 andplunger83 abruptly stop their downward movement due to the abrupt closure of eitherHCCI nozzle outlet126 orconventional nozzle outlets128. Because pressure spikes can sometimes cause an uncontrolled and undesirable secondary injection due to an interaction of components and passageways over a brief instant after main injection has ended, apressure relief passage75 extends betweenactuation fluid passage68 and a low pressure vent. Whenspool valve member55 is in its downward position, such as during an injection event, apin71 holds pressure reliefball valve member70 downward to close aseat72. Whenpressure relief valve70 is in this position,actuation fluid passage68 is closed to pressurerelief passage75 and pressure can build withinactuation fluid passage68. However, immediately after injection events, whenpiston80 andplunger83 are hydraulically slowed and stopped, residual high pressure inactuation fluid passage68 can act againstpressure relief valve70. Because pressure withinspool cavity65 is high,spool valve member55 is hydraulically balanced and can move toward its upward position under the action of biasingspring60.Pressure relief valve70 can then lift off ofseat72 to openactuation fluid passage68 to pressurerelief passage75, thus allowing pressure withinactuation fluid passage68 to be vented. At the same time, upward movement ofpressure relief valve70, and therefore pin71 can aid in the movement ofspool valve member55 toward its upward position.

Referring toFIG. 3,fuel injector30 includes anozzle assembly90 with aneedle valve109. As illustrated,needle valve100 preferably includes an HCCIneedle valve member107 and a conventionalneedle valve member117. HCCIneedle valve member107 is movable between an open position fluidly connectingfuel pressurization chamber85 toHCCI nozzle outlet126, and a closed position.Valve member107 is biased toward its closed position by a biasingspring101. HCCIneedle valve member107 preferably includes astop pin105 that defines the travel distance between its open and closed positions. HCCIneedle valve member107 also includes apiston portion103 that provides a closinghydraulic surface106 exposed to fluid pressure in an HCCIneedle control chamber102, which is fluidly connected to pressurecommunication passage88. Aneedle portion104 is also included on HCCIneedle valve member107 that provides an openinghydraulic surface110 exposed to fluid pressure in anHCCI nozzle chamber109. Preferably,nozzle chamber109 is defined in part by HCCIneedle valve member107 and conventionalneedle valve member117 and is fluidly connected to fuelpressurization chamber85 via an HCCInozzle supply passage108, defined by conventionalneedle valve member117.

Preferably, openinghydraulic surface110 and closinghydraulic surface106 are sized and positioned such that whenneedle control chamber102 is open tohigh pressure passage51 viapressure communication passage88,needle valve member107 will remain in, or move toward, its downward closed position, regardless of the fuel pressure acting on openinghydraulic surface110. Whenneedle valve member107 is in its closed position, a conical orspherical valve surface121 provided onneedle portion104 closes aconical valve seat122 provided onneedle valve member117 to blocknozzle supply passage108 from fluid communication with HCCI nozzle outlet(s)126. However, whenneedle control chamber102 is open tolow pressure passage40 and fuel pressure withinnozzle chamber109 reaches an HCCI valve opening pressure,needle valve member107 can be lifted against the bias of biasingspring101 toward its open position, thus liftingvalve surface121 fromvalve seat122. It should be appreciated that the HCCI valve opening pressure is a function of the force of biasingspring101 as well as the size of openinghydraulic surface110. Fuel can now spray intocylinder25 viaHCCI nozzle outlet126 whenseat122 is open. Recall that when fuel injection is occurring viaHCCI nozzle outlet126,fuel injector30 is in its first configuration, as indicated above. Whenfuel injector30 is in this configuration, fuel spray intocylinder25 is at a relatively small angle θ with respect toinjector centerline29 andcylinder centerline27. As best illustrated inFIG. 3,HCCI nozzle outlet126 is preferably defined such that θ is zero for this embodiment of the present invention.

Returning tonozzle assembly90,needle valve109 also includes a conventionalneedle valve member117 that provides anouter check member115.Needle valve member117 has a closinghydraulic surface116, provided onouter check member115, that is exposed to fluid pressure in a conventionalneedle control chamber112 which is defined at least in part byinjector body31.Needle valve member117 also preferably includes an openinghydraulic surface120 that is exposed to fluid pressure in anozzle supply passage118, defined byinjector body31. Conventionalneedle valve member117 is biased toward a closed position by a biasingspring111. As with HCCIneedle valve member107, preferably the respective surfaces and strengths of springs, closinghydraulic surface116, openinghydraulic surface120 and biasingspring111 are such thatneedle valve member117 will remain in its downward position when high pressure is acting on closinghydraulic surface116, regardless of the fuel pressure acting on openinghydraulic surface120.

When the fuel pressure force acting on closinghydraulic surface116 and the biasing force of biasingspring111 exceed the fuel pressure force acting on openinghydraulic surface120,needle valve member117 remains in its biased, closed position, blockingconventional nozzle outlets128. In other words,valve surface123 is in contact to closeseat124. When the fuel pressure force acting on openinghydraulic surface120 exceeds the fluid pressure acting on closinghydraulic surface116, the biasing force of biasing spring111 (i.e. conventional valve opening pressure), the biasing force ofspring101 and the hydraulic force on closinghydraulic surface106,needle valve member117 is lifted to an open position fluidly connectingnozzle supply passage118 withconventional nozzle outlets128. When fuel injection is occurring viaconventional nozzle outlets128, recall thatfuel injector30 is in its second configuration, as indicated above. It should be appreciated that a guide clearance preferably exists betweenneedle valve member117 andinjector body31, such that fuel substantially cannot migrate aroundneedle valve member117 and spray out ofHCCI nozzle outlet126 during the conventional injection event. Whenfuel injector30 is in this second configuration, fuel spray intocylinder25 is in a second spray pattern corresponding to the relatively large angle α ofconventional nozzle outlets128 with respect tocenterlines27 and29.

Note that whileneedle valve member107 is also lifted by the upward movement ofneedle valve member117,HCCI nozzle outlet126 remains closed during the conventional injection event. This is due to a number of factors. First, the valve opening pressure of conventionalneedle valve member117 is less than the valve opening pressure of HCCIneedle valve member107. In other words, when low pressure is acting on both HCCI closinghydraulic surface106 and conventional closinghydraulic surface116 in their respectiveneedle control chambers102,112, conventionalneedle valve member117 the conventional valve opening pressure will be reached prior to the HCCI valve opening pressure being reached. It should be appreciated that because conventionalneedle valve member117 must overcome the spring force of bothHCCI biasing spring101 andconventional biasing spring111, openinghydraulic surface120 should be sized appropriately with respect to openinghydraulic surface110 to allow for a lower conventional valve opening pressure than the HCCI valve opening pressure. Thus, conventionalneedle valve member117 will begin to move toward its open position, moving HCCIneedle valve member107 upward, before HCCIneedle valve member107 can move upward on its own. In addition,stop pin105 of HCCIneedle valve member107 also limits the upward movement of conventionalneedle valve member117. Thus, once conventionalneedle valve member117 reaches its upward position, stoppin105 prevents HCCIneedle valve member107 from lifting away from conventionalneedle valve member117. Those skilled in the art will recognize that the respective HCCI valve opening pressure and conventional valve opening pressure can be set somewhat independently by appropriate sizing ofsurfaces110,120,106 and116 as well as choosing appropriate preloads onsprings101 and111.

II.FIG. 5

Referring now toFIG. 5, there is shown another embodiment of anozzle assembly190 for use with the present invention.Nozzle assembly190 includes a nestedneedle valve200 that provides an inner HCCIneedle valve member207 and an outer or conventionalneedle valve member217. It should be appreciated that with minor modifications tofuel injector30,needle valve200 could be inserted intoinjector body31 to create a complete injector. Thus, the majority offuel injector30 components described for theFIGS. 1-4 embodiment of the present invention remain unchanged whennozzle assembly190 is substituted intofuel injector30. For instance, when utilized withnozzle assembly190,fuel injector30 continues to include a firstelectrical actuator32 that controls the flow of hydraulic fluid to acontrol surface63 ofspool valve member55 and the closinghydraulic surface206 of HCCIneedle valve member207. In addition,fuel injector30 also preferably continues to provide a secondelectrical actuator42 that controls the pressure on the closinghydraulic surface216 of conventionalneedle valve member217. Further,fuel injector30 also provides a piston/plunger assembly for pressurization of fuel withinfuel injector30 to injection levels. While these like components will not be described in detail, those components offuel injector30 andnozzle assembly190 that differ from the previous embodiment of the present invention will be discussed.

HCCI valve member207 is movable between a downward, closed position and an upward, open position, and is biased toward its closed position by a biasingspring201. Astop pin205 limits the upward movement ofneedle valve member207. HCCIneedle valve member207 provides a closinghydraulic surface206 that is exposed to fluid pressure in an HCCIneedle control chamber202 which is fluidly connected to pressure communication passage88 (FIG. 22b). Also provided onneedle valve member207 is an openinghydraulic surface210 that is exposed to fluid pressure in anozzle chamber209.Nozzle chamber209 is fluidly connected to fuel pressurization chamber85 (FIG. 2c) via anozzle supply passage218 and anozzle connection passage208. Preferably, the relative sizes and strengths of closinghydraulic surface206, openinghydraulic surface210 and biasingspring201 are such thatneedle valve member207 remains in, or moves toward, its downward position when closinghydraulic surface206 is exposed to high pressure actuation fluid, regardless of whether fuel pressure at injection levels is being exerted on openinghydraulic surface210. Whenneedle valve member207 is in its closed position, a set ofHCCI nozzle outlets226 are blocked from anozzle supply passage218. Whenneedle valve member207 is in its open position, corresponding to the first configuration offuel injector30,HCCI nozzle outlets226 are open tonozzle supply passage218 via anozzle supply passage208 andnozzle chamber209. Whenfuel injector30 is in this configuration, fuel spray intocylinder25 viaHCCI nozzle outlets226 is at a relatively small angle θ with respect toinjector centerline29 andcylinder centerline27. However, in contrast with the previously illustrated embodiment, note that θ is greater than zero for this embodiment. It should, however, be appreciated that one or more HCCI nozzle outlet(s) being oriented at a zero angle, as in the previous embodiment, could instead be provided.

As illustrated, HCCIneedle valve member207 is movable within a bore defined by a conventionalneedle valve member217. Conventionalneedle valve member217 includes a closinghydraulic surface216 that is exposed to fluid pressure in a conventionalneedle control chamber212, which is in fluid communication with control pressure line77 (FIG. 2c). Fluid pressure in conventionalneedle control chamber212 is controlled by secondelectrical actuator42, in the same manner described for the previous embodiment of the present invention. Also provided on conventionalneedle valve member217 is an openinghydraulic surface220 that is exposed to fluid pressure in anozzle chamber219.Nozzle chamber219 is fluidly connected to fuel pressurization chamber85 (FIG. 2c) vianozzle supply passage218. Preferably, as with HCCIneedle valve member207, the relative sizes and strengths of closinghydraulic surface216, openinghydraulic surface220 and biasingsprings201 and211 are such that conventionalneedle valve member217 remains in, or moves toward its downward, closed position when high pressure fuel is acting on closinghydraulic surface216, regardless of whether fuel pressure acting on openinghydraulic surface220 has reached injection levels. Whenneedle valve member217 is in its closed position, a set ofconventional nozzle outlets228 are blocked fromnozzle chamber219. In other words,valve surface221 is seated inseat222. Whenneedle valve member217 is in its open position, corresponding to the second configuration offuel injector30,nozzle outlets228 are open tonozzle chamber219, and pressurized fuel can spray intocylinder25. Whenfuel injector30 is in this second configuration, fuel spray intocylinder25 is in a second spray pattern corresponding to the relatively large angle α ofconventional nozzle outlets228 with respect tocenterlines27 and29.

Note that whileneedle valve member207 is also lifted by the upward movement ofneedle valve member217,HCCI nozzle outlets226 remains closed during the conventional injection event. This is due to a number of factors, similar to those discussed for the previous embodiment of the present invention. First, the valve opening pressure of conventionalneedle valve member217 is less than the valve opening pressure of HCCIneedle valve member207. In other words, when low pressure is acting on both HCCI closinghydraulic surface206 and conventional closinghydraulic surface216 in their respectiveneedle control chambers202,212, conventionalneedle valve member217 the conventional valve opening pressure will be reached prior to the HCCI valve opening pressure being reached. It should be appreciated that because conventionalneedle valve member217 must overcome the spring force of bothHCCI biasing spring201 andconventional biasing spring211, openinghydraulic surface220 should be sized appropriately for a desired conventional valve opening pressure that is preferably lower than the HCCI valve opening pressure. Thus, conventionalneedle valve member217 will begin to move toward its open position, moving HCCIneedle valve member207 upward, before HCCIneedle valve member207 can move upward on its own. In addition, upward movement of HCCIneedle valve member207 and conventionalneedle valve member217 are limited bystop pin205. Thus, once conventionalneedle valve member217 reaches its upward position, stoppin205 prevents HCCIneedle valve member207 from lifting away from conventionalneedle valve member217.

III.FIGS. 6-7

Referring now toFIGS. 6 and 7, there is illustrated a schematic representation of afuel injector230 as well as anothernozzle assembly290 for use with the present invention. Note thatfuel injector230 is very similar tofuel injector30, and contains a number of similar components. For instance,fuel injector230 also provides two electrical actuators that control pressure and fluid flow within the injector. However, in this embodiment, firstelectrical actuator232 controls the pressure of hydraulic fluid acting on a control hydraulic surface ofspool valve member255, which controls flow of high pressure actuation fluid tointensifier piston280. The secondelectrical actuator242 controls the pressure of hydraulic fluid acting on the closing surface of the HCCIneedle valve member307. It should be appreciated that firstelectrical actuator232 and secondelectrical actuator242 are preferably similar to firstelectrical actuator32 and secondelectrical actuator42 disclosed for theFIGS. 2-4 embodiment of the present invention. However, it should be appreciated that they could instead be any suitable actuators, including but not limited to piezo-electric actuators voice coils or possibly even stepper motors. In addition, as best illustrated inFIG. 6,fuel injector230 also provides an intensifier piston/plunger assembly, which is preferably similar to that shown inFIG. 2a, for the pressurization of fuel within the injector to injection levels. This embodiment differs in thatouter needle317 is biased closed by aspring311, but is not directly controlled. In other words, outer needle valve member does not include a closing hydraulic surface exposed to different pressures based upon the energization state ofactuators32 and42.

Returning toFIGS. 6 and 7,nozzle assembly290 provides aneedle valve300 having an HCCIneedle valve member307, a conventional or outerneedle valve member317 and aninner sealing member315. As illustrated inFIG. 7, inner sealingmember315 is preferably biased to a downward position by abellville spring325 to block anannular sac323 from asac324. Preferably,spring325 will holdinner sealing member315 in this downward position continuously, regardless of whetherouter check member317 is in its upward, open position or its downward, closed position. It should be appreciated that while a bellville spring has been illustrated, any other biasing means could be included to maintaininner sealing member315 in its downward position.

HCCIneedle valve member307 is movable between an upward, open position and a downward, closed position and is biased toward its closed position (as shown) by a biasingspring301. HCCIneedle valve member307 includes a closinghydraulic surface306 that is exposed to fluid pressure in an HCCIneedle control chamber302. When secondelectrical actuator242 is energized,needle control chamber302 is preferably fluidly connected to highpressure oil rail14 via a high pressure passage and a pressure control line defined byfuel injector230. Alternatively, when secondelectrical actuator242 is de-energized,needle control chamber302 is preferably fluidly connected tolow pressure reservoir12 by the pressure control line and a low pressure passage defined byfuel injector230.Needle valve member307 also preferably includes an openinghydraulic surface310 that is exposed to fuel pressure in a first,HCCI nozzle chamber309. Preferably,HCCI nozzle chamber309 is fluidly connected to a fuel pressurization chamber (such asfuel pressurization chamber85, illustrated inFIG. 2b) via anozzle supply passage318, defined byinjector body231. The relative sizes and strengths of openinghydraulic surface310, closinghydraulic surface306 and biasingspring301 are preferably such thatneedle valve member307 will remain in, or move towards, its downward, closed position whenneedle control chamber302 is open tohigh pressure rail14.

Needle valve member307 includes a knifeedge valve surface321 that closes aplanar valve seat322 that is included on outerneedle valve member317 whenneedle valve member307 is in its downward, closed position. Whenvalve seat322 is closed,nozzle chamber309 is blocked from anHCCI nozzle outlet326 defined byinjector body231. Whenvalve seat322 is open, such as whenneedle valve member307 is away fromvalve seat322,nozzle chamber309 is fluidly connected to HCCI nozzle outlet(s)326 via anozzle connection passage308 defined by conventionalneedle valve member317 and aspray passage305 defined by inner sealingmember315. Whenvalve seat322 is open,fuel injector230 is in its first configuration. Whenfuel injector230 is in this configuration, fuel spray intocylinder25 is at a relatively small angle θ with respect toinjector centerline229 andcylinder centerline27. As best illustrated inFIG. 7,HCCI nozzle outlet126 is preferably defined such that θ is zero for this embodiment of the present invention.

Returning now toneedle valve300, also included is conventionalneedle valve member317 which is movable between an upward, open position and a downward, closed position.Needle valve member317 is biased toward its downward position by a biasingspring311.Needle valve member317 includes an openinghydraulic surface320 that is exposed to fuel pressure in a second orconventional nozzle chamber319. Preferably,nozzle chamber319 is fluidly connected to a fuel pressurization chamber vianozzle supply passage318. Whenneedle valve member317 is in its downward position,conventional nozzle outlets328 are blocked fromnozzle chamber319. Whenneedle valve member317 is away from its closed position,fuel injector230 is in its second configuration andconventional nozzle outlets328 are open tonozzle chamber319 to allow fuel spray fromconventional nozzle outlets328 to commence. When fuel injection is occurring viaconventional nozzle outlets328, recall thatfuel injector230 is in its second configuration, as indicated above. Whenfuel injector230 is in this second configuration, fuel spray intocylinder25 is in a second spray pattern corresponding to the relatively large angle α ofconventional nozzle outlets328 with respect tocenterlines27 and229.

Note that whileneedle valve member307 is also lifted by the upward movement ofneedle valve member317,HCCI nozzle outlet326 remains closed during the conventional injection event. This is due to the fact that high pressure actuation fluid acting on closinghydraulic surface306 preventsvalve member307 from lifting off itsseat322. The respective valve opening pressures can be set with some independence by setting appropriate preloads forsprings301 and311, as well as by appropriately sizing closinghydraulic surface306 and openinghydraulic surfaces310 and320. However, the HCCI valve opening pressure is preferably lower than the conventional valve opening pressure to avoid simultaneously opening both sets of outlets. When high pressure is acting on HCCI closinghydraulic surface306, the conventional valve opening pressure will be reached before a pressure sufficient to lift HCCIneedle valve member307 against the force of both hydraulic fluid acting on closinghydraulic surface306 and the downward force of biasingspring301. It should be appreciated that because conventionalneedle valve member317 must overcome the spring force of bothHCCI biasing spring301 andconventional biasing spring311, as well as the hydraulic force being exerted on closinghydraulic surface302, openinghydraulic surface320 should be sized appropriately with respect to openinghydraulic surface310 to allow for a higher conventional valve opening pressure than the HCCI valve opening pressure. Thus, conventionalneedle valve member317 will begin to move toward its open position, moving HCCIneedle valve member307 upward, before HCCIneedle valve member307 can move upward on its own. It should be noted that, when operating in an HCCI mode, fuel pressure should be maintained below the conventional valve opening pressure to avoid opening both sets of outlets simultaneously. However, simultaneous opening may be desirable in some instances.

IV.FIGS. 8-9

Referring now toFIGS. 8 and 9, there is shown a schematic representation of afuel injector330 according to another embodiment of the present invention, as well as anozzle assembly390 for use withfuel injector330. The fuel injector ofFIGS. 8 and 9 is similar to that ofFIGS. 6 and 7 in that the outer orHCCI needle407 is not directly controlled via the application of high ore low pressure to a closing hydraulic surface. Instead,needle407 is merely spring biased closed. In theFIGS. 6 and 7 embodiment, the HCCI needle was directly controlled while the conventional needle was merely spring biased. Note also thatfuel injector330 is very similar tofuel injector30, and contains a number of similar components. For instance,fuel injector330 also provides two electrical actuators that control pressure and fluid flow within the injector. It should be appreciated that firstelectrical actuator332 and secondelectrical actuator342 are preferably similar to firstelectrical actuator32 and secondelectrical actuator42 disclosed for theFIGS. 2-4 embodiment of the present invention, however, it should be appreciated that they could instead be any suitable actuators, such as piezoelectric actuators voice coils, or stepper motors. In addition, as best illustrated inFIG. 8,fuel injector330 also provides apiston380/plunger383 assembly for the pressurization of fuel within the injector to injection levels. As withactuator32 discussed previously, firstelectrical actuator332 controls fluid pressure to a control surface onspool valve member355, which in turn controls the movement of the same. When spool valve member is moved from a first, biased position to a second, advanced position, ahydraulic surface381 of anintensifier piston380 is exposed to high pressure actuation fluid. Preferably, this actuation fluid is an amount of high pressure engine lubricating oil, however, it should be appreciated that any suitable actuation fluid could be substituted, such as fuel or coolant fluid. When high pressure acts onhydraulic surface381,piston380, together with aplunger381, advance to pressurize fuel withinfuel injector330 for an injection event.

Returning now tonozzle assembly390, a nestedneedle valve400 is provided that includes an HCCIneedle valve member407 and a conventionalneedle valve member417. Unlike the previous embodiments that have been illustrated, note that HCCIneedle valve member407 is the outer needle valve member, while the conventionalneedle valve member417 is the inner needle valve member in this embodiment. Outer HCCIneedle valve member407 is movable between a downward closed position and an upward open position, openingHCCI nozzle outlets426, and is limited in its upward movement by asleeve406. HCCIneedle valve member407 is biased toward its downward position by a biasingspring401, closingHCCI nozzle outlets426. Included on HCCIneedle valve member407 is an openinghydraulic surface410 that is exposed to fluid pressure in anozzle supply passage418. As with previously disclosed embodiments of the present invention, preferably the relative size and strength of biasingspring401 and openinghydraulic surface410 are such thatneedle valve member407 remains in its closed position when fuel pressure innozzle supply passage418 is below a predetermined HCCI valve opening pressure.

When HCCIneedle valve member407 is in its closed position, such as when firstelectrical actuator332 is de-energized andpiston380 andplunger383 have not moved to pressurize fuel withininjector330, avalve surface421 included onneedle valve member407 is in contact with aflat valve seat422, included on conventionalneedle valve member417. Whenvalve seat422 is closed,valve surface421 ofvalve member407 blocksnozzle supply passage418 from fluid communication with anHCCI nozzle outlet426. Whenvalve seat422 is open, such as whenneedle valve member407 is in its upward position,HCCI nozzle outlet426 is open tonozzle supply passage418 via anannulus404 and aspray passage405, both defined byneedle valve member407. Whenneedle valve member407 is in this position, corresponding to a first configuration offuel injector330, pressurized fuel can flow throughannulus404 andspray passage405 and spray intocylinder25 viaHCCI nozzle outlet426. Whenfuel injector330 is in this configuration, fuel spray intocylinder25 is at a relatively small angle θ with respect toinjector centerline329 andcylinder centerline27. As best illustrated inFIG. 3,HCCI nozzle outlet426 is preferably defined such that θ is small and maybe even zero for this embodiment of the present invention. It should be appreciated that while only oneHCCI nozzle outlet426 has been illustrated,tip portion395 could define any practical number of HCCI nozzle outlets sized and positioned to direct the spray of fuel at a desired, and likely relatively small, angle with respect toinjector centerline29 orcylinder centerline27. In addition, it should be appreciated that when HCCIneedle valve member407 lifts to its upward position, an amount of fuel can migrate into aspring chamber402 located aboveneedle valve member407. Therefore, a low pressurefuel return line427 preferably fluidly connectsspring chamber402 to a fuel drain to allow this migrating fuel to be displaced asneedle valve member407 lifts to its upward position, as shown.

Returning again toneedle valve400, inner conventionalneedle valve member417 is movable between an upward, open position and a downward, closed position.Needle valve member417 preferably includes anupper guide portion403 and alower guide portion423. In addition to guidingneedle valve member417 in its movement, these matched clearances preferably help stop the migration of various injector fluids past the guide surfaces. A biasingspring411 preferably biases conventionalneedle valve member417 toward its downward, closed position.Needle valve member417 includes a closinghydraulic surface416 that is exposed to fluid pressure in aneedle control chamber412. Fluid pressure inneedle control chamber412 is preferably controlled by secondelectrical actuator342. Preferably, when secondelectrical actuator342 is de-energized, closinghydraulic surface416 is exposed to an amount of high pressure actuation fluid, such as engine lubricating oil. When secondelectrical actuator342 is energized, closinghydraulic surface416 is then exposed to low pressure. While engine lubricating oil is preferably utilized as the actuation fluid exposed to closinghydraulic surface416, it should be appreciated that any suitable actuation fluid, such as fuel, could also be utilized.

Also provided onneedle valve member417 is an openinghydraulic surface420 that is exposed to fluid pressure innozzle chamber409. When pressure withinnozzle supply passage418 is below a conventional valve opening pressure,needle valve member417 remains in its downward, biased position, closing a set ofconventional nozzle outlets428. It should be appreciated that the valve opening pressure ofneedle valve member417 should be lower than the valve opening pressure ofneedle valve member407. This will help to ensure thatneedle valve member407 does not move to its upward, open position as conventionalneedle valve member417 lifts for a conventional injection event. Thus, as a result of the relatively high valve opening pressure ofneedle valve member407, biasingspring401 will holdvalve member407 in a downward position with respect toneedle valve member417 such thatvalve seat422 is not opened during a conventional injection event. In other words, fuel pressure preferably remains below the HCCI valve opening pressure at least until HCCI needle valvemember contacts sleeve406, which acts to holdFlat seat422 closed during a conventional injection event. In addition,lower guide portion423 is positioned such thatnozzle outlet426 remains blocked fromnozzle chamber409 whenneedle valve member417 is in its open position.

Whenneedle valve member417 is in its closed position,conventional nozzle outlets428 are closed, blocking fuel spray intocylinder25 via these orifices. However, when fuel pressure acting on openinghydraulic surface420 exceeds a valve opening pressure,needle valve member417 is lifted to its open position, corresponding to the second configuration offuel injector330. Pressurized fuel in nozzle supply passage408 can then spray intocylinder25 viaconventional nozzle outlets428. When fuel injection is occurring viaconventional nozzle outlets428, recall thatfuel injector330 is in its second configuration, as indicated above. Whenfuel injector330 is in this second configuration, fuel spray intocylinder25 is in a second spray pattern corresponding to the relatively large angle α ofconventional nozzle outlets428 with respect tocenterlines27 and329.

Note that whileneedle valve member407 is also lifted by the upward movement ofneedle valve member417,HCCI nozzle outlet426 remains closed during the conventional injection event. This is due to a number of reasons. First, the difference in the valve opening pressures of HCCIneedle valve member407 and conventionalneedle valve member417. The conventional valve opening pressure required to lift conventionalneedle valve member417 from its closed position is less than the HCCI valve opening pressure required to lift HCCIneedle valve member307 from its closed position. It should be appreciated that because conventionalneedle valve member417 must overcome the spring force of bothHCCI biasing spring401 andconventional biasing spring411, openinghydraulic surface420 should be sized appropriately with respect to openinghydraulic surface410 to allow for a lower conventional valve opening pressure than the HCCI valve opening pressure. Thus, conventionalneedle valve member417 will begin to move toward its open position, moving HCCIneedle valve member407 upward, before HCCIneedle valve member407 can move upward on its own. In addition,sleeve406 also limits the upward movement of conventionalneedle valve member417. Thus, once conventionalneedle valve member417 reaches its upward position,sleeve406 prevents HCCIneedle valve member407 from lifting away from conventionalneedle valve member417.

V.FIGS. 10-11

Referring now toFIGS. 10 and 11, there is illustrated a schematic representation of afuel injector430 according to another embodiment of the present invention, as well as anozzle assembly490 for use withfuel injector430.Fuel injector430 is similar tofuel injector330, discussed previously and illustrated inFIGS. 8 and 9. However, whereas secondelectrical actuator342 of fuel injector330 (FIG. 8) controlled the flow of hydraulic fluid to the top of conventionalneedle valve member417, secondelectrical actuator442 of fuel injector430 (FIG. 10) controls the flow of actuation fluid exposed to the top of an HCCIneedle valve member507. However, as illustrated, firstelectrical actuator432 performs in a similar manner to firstelectrical actuator332, discussed previously. For instance, firstelectrical actuator432 controls the flow of actuation fluid, preferably engine lubricating oil, to a control hydraulic surface on aspool valve member455. Whenspool valve member455 moves from its first, biased position to a second position, high pressure actuation fluid can act on ahydraulic surface481 of anintensifier piston480.Piston480, together withplunger483, can then act to pressurize fuel withinfuel injector430. Whilefuel injector430 preferably utilizes engine lubricating oil as an actuation fluid, it should be appreciated that other fluids, such as fuel or coolant fluid, could also be utilized. For instance, it should be appreciated that with modifications to various fluid passages,fuel injector430 could be part of an all fuel system in which fuel is used as both the working fluid and the injection fluid.

Returning now tofuel injector430, a nestedneedle valve500 includes an inner, HCCIneedle valve member507 and an outer, conventionalneedle valve member517.Needle valve member507, which is preferably a pin, provides a closinghydraulic surface506 that is exposed to fluid pressure in an HCCIneedle control chamber502 that is connected to apressure control passage501. When secondelectrical actuator442 is de-energized, closinghydraulic surface506 is exposed to high pressure actuation fluid in apressure control passage501. It should be appreciated that if secondelectrical actuator442 is similar to second electrical actuator42 (FIG. 2c),pressure control passage501 will be open to high pressure by a valve member attached to secondelectrical actuator442. When secondelectrical actuator442 is energized, closinghydraulic surface506 is exposed to low pressure inpressure control passage501. Once again it should be appreciated that if secondelectrical actuator442 is similar to second electrical actuator42 (FIG. 2c), the actuator valve member will be moved byactuator442 to blockpressure control passage501 from high pressure fluid and open the same to a low pressure drain passage.

Needle valve member507 also provides an openinghydraulic surface510 that is exposed to fluid pressure in anozzle chamber509.Nozzle chamber509 is fluidly connected to anozzle supply passage518 defined byinjector body431 by aconnection passage508 that is defined by conventionalneedle valve member517. Closinghydraulic surface506 and openinghydraulic surface510 are preferably sized such that when high pressure is acting on closinghydraulic surface506 inneedle control chamber502,needle valve member507 will remain in, or move toward, a downward closed position, as shown. Similarly, these surfaces are preferably sized such thatneedle valve member507 will be lifted to its open position by the fuel pressure innozzle chamber509 is above an HCCI valve opening pressure, and low pressure is acting on closinghydraulic surface506.

Whenneedle valve member507 is in its downward position, an angular knifeedge valve surface521 ofneedle valve member507 closes aflat valve seat522 provided onneedle valve member517 to blockHCCI nozzle outlets526 fromnozzle supply passage518. Whenpressure control passage501 is open to low pressure, an HCCI valve opening fuel pressure acting on openinghydraulic surface510 innozzle chamber509 will liftneedle valve member507 to an open position. However, it should be appreciated that for this embodiment of the present invention, fuel is preferably supplied at a supply pressure higher than the HCCI valve opening pressure. Thus, injection pressure for an HCCI injection event can be equal to a medium fuel supply pressure.

Whenneedle valve member507 is in its open position, corresponding to the first configuration offuel injector430,valve surface521 is away fromvalve seat522 to openconnection passage508 toHCCI nozzle outlets526 viaspray passage504. Whenneedle valve member507 is in this position, fuel spray viaHCCI nozzle outlets526 intocylinder25 can commence. Whenfuel injector430 is in this configuration, fuel spray intocylinder25 is at a relatively small angle θ with respect toinjector centerline429 andcylinder centerline27. As best illustrated inFIG. 11, the centerlines ofHCCI nozzle outlets526 preferably intersect. This orientation ofHCCI nozzle outlets526 is preferable because it is believed that collision of the flow streams intocylinder25 could be beneficial in the atomization and mixing of fuel with air. However, it should be appreciated that the centerlines of these nozzle outlets need not intersect. In addition, it should be appreciated that while more than oneHCCI nozzle outlet526 has been illustrated,injector430 could instead include only a single HCCI nozzle outlet.

Returning now toneedle valve500, conventionalneedle valve member517 includes an openinghydraulic surface520 that is exposed to fluid pressure innozzle chamber519.Needle valve member517 is biased toward its downward, closed position by a biasingspring511. Preferably, the relative sizes and strength of openinghydraulic surface520, biasingspring511 and closinghydraulic surface506 ofneedle valve member507 are such thatneedle valve member517 will be lifted to its upward, open position when openinghydraulic surface520 is exposed to intensified high pressure fuel innozzle chamber519, that corresponds to a conventional valve opening pressure, which is preferably substantially higher than both the fuel supply pressure and the HCCI valve opening pressure. In other words, the valve opening pressure ofneedle valve member517 should be greater than that ofneedle valve member507 such thatneedle valve member507 will lift for the lower HCCI injection pressures. In addition, the conventional valve opening pressure will be relatively high to overcome the downward force of both biasingspring511 and the high pressure fluid force acting on closinghydraulic surface506 ofneedle valve member507. Thus, the conventional injection event can occur without secondelectrical actuator442 being activated. Whenneedle valve member517 is in its downward, biased position,nozzle outlets528 are blocked. However, whenneedle valve member517 is in its upward, open position,conventional nozzle outlets528 are open and fuel spray intocylinder25 can commence. When fuel injection is occurring viaconventional nozzle outlets528, recall thatfuel injector430 is in its second configuration. Whenfuel injector430 is in this second configuration, fuel spray intocylinder25 is in a second spray pattern corresponding to the relatively large angle α ofconventional nozzle outlets528 with respect tocenterlines27 and429.

Note that whileneedle valve member507 is also lifted by the upward movement ofneedle valve member517,HCCI nozzle outlets526 remains closed during the conventional injection event. This is due to a number of factors. When high pressure is acting on HCCI closinghydraulic surface506, the HCCIneedle valve member507 will remain seated. It should be appreciated that because conventionalneedle valve member517 must overcome the spring force ofconventional biasing spring111, as well as the fluid force acting on closinghydraulic surface506 ofneedle valve member507, openinghydraulic surface520 should be sized appropriately so that conventional injection events only occur when fuel pressure is intensified by movement ofintensifier piston480. Thus, conventionalneedle valve member517 will begin to move toward its open position, moving HCCIneedle valve member507 upward, while HCCIneedle valve member507 remains seated. In addition, the upward movement of HCCIneedle valve member507, and thus the upward movement of conventionalneedle valve member117, is limited byinjector body431. Thus, once conventionalneedle valve member517 reaches its upward position, HCCIneedle valve member507 is prevented from lifting away from conventionalneedle valve member517. This embodiment permits HCCI injection events at a medium supply pressure, and conventional injection events at a high intensified pressure.

VI.FIGS. 12-15

Referring now toFIG. 12 there is illustrated anozzle assembly590 according to yet another embodiment of the present invention.Nozzle assembly590 provides aneedle valve assembly600 that includes an HCCIneedle valve member607, a conventionalneedle valve member617 and an innersealing sleeve member615.Needle valve600 has been illustrated in a first position in which a set ofHCCI nozzle outlets626 and a set ofconventional nozzle outlets628, both of which are defined byinjector body531, are blocked.Needle valve600 is movable from this first position to a second position in whichHCCI nozzle outlets626 are open andconventional nozzle outlets628 are blocked.Needle valve600 is also movable to a third position in whichHCCI nozzle outlets626 are blocked andconventional nozzle outlets628 are open. As best illustrated inFIG. 12, inner sealingmember615 is biased toward a downward position by a biasingspring614. Inner sealingmember615 is preferably maintained in this position throughout the operation offuel injector530, such that avalve surface625 ofinner sealing member615 closes aconical valve seat627 defined byinjector body530 to separateHCCI nozzle outlets626 fromconventional nozzle outlets628.

Whenneedle valve600 is in its first position, HCCIneedle valve member607 and conventionalneedle valve member617 are both in downward, closed positions, as shown. Whenneedle valve member607 is in its closed position, avalve surface621 provided onneedle valve member607 closes aconical valve seat622 defined byinjector body531. Similarly, whenneedle valve member617 is in its closed position, avalve surface623 provided onneedle valve member617 closes aconical valve seat624 defined byinjector body531.Needle valve member607 andneedle valve member617 are biased toward their closed positions by a biasingspring601 and abiasing spring611, respectively.Needle valve member607 includes an openinghydraulic surface610 that is exposed to fuel pressure innozzle chamber609.Nozzle chamber609 is fluidly connected to a source of pressurized fuel via anozzle supply passage608. When fuel pressure acting on openinghydraulic surfaces610A and610B withinnozzle supply chamber609 exceeds the first valve opening pressure defined by the downward bias of biasingspring601,needle valve member607 is lifted to its open position, corresponding to the second position ofneedle valve600. Recall that this second position ofneedle valve600 corresponds to a first configuration offuel injector530. Whenfuel injector30 is in this configuration, fuel spray intocylinder25 is at a relatively small angle θ with respect toinjector centerline529 andcylinder centerline29. However, depending upon the control strategy utilized forneedle valve600, the valve opening pressures forneedle valve member607 andneedle valve member617 could be the same or different, as illustrated below.

In addition to HCCIneedle valve member607,needle valve600 also provides a conventionalneedle valve member617.Needle valve member617 is movable between a downward, closed position and an upward, open position, and is biased toward its closed position by a biasingspring611.Needle valve member617 provides an openinghydraulic surface620 that is exposed to fuel pressure in anozzle chamber619.Nozzle chamber619 is fluidly connected to fuel pressurization chamber585 via anozzle supply passage618. When the fuel pressure acting on openinghydraulic surface620 exceeds the downward force of biasingspring611,needle valve member617 is lifted to its open position, corresponding to the third position ofneedle valve600. This third position ofneedle valve600 corresponds to a second configuration offuel injector530. Whenfuel injector530 is in this second configuration, fuel spray intocylinder25 is in a second spray pattern corresponding to the relatively large angle α ofconventional nozzle outlets628 with respect tocenterlines27 and529.

It should be appreciated that control ofneedle valve600 can be carried out in a number of different manners. For instance, referring in addition toFIG. 13 there is shown a schematic representation of afuel injector530 according to a first control strategy forneedle valve600. It should be appreciated that only those components offuel injector530 that are integral to the control ofneedle valve600 have been represented.Injector530 includes a firstelectrical actuator532 and a secondelectrical actuator542. Firstelectrical actuator532 is preferably a two-position solenoid and secondelectrical actuator542 is preferably a three-position check control actuator. However, it should be appreciated that other suitable actuators, such as piezoelectric actuators, could be substituted.

Firstelectrical actuator532 controls actuation fluid pressure on a control surface of aspool valve member555. It should be appreciated thatspool valve member555 could be similar tospool valve member55, as illustrated inFIG. 2. In this case,spool valve member555 could be movable between a biased, upward position and a downward position. Ahydraulic surface581 ofpiston580 could be exposed to low pressure whenspool valve member555 is in its upward position and it could be exposed to high pressure actuation fluid whenspool valve member555 is in its downward position. It should be appreciated thatspool valve member555 could also be oriented in a different manner, such thathydraulic surface581 ofpiston580 is exposed to high pressure actuation fluid whenspool valve member555 is in its upward position and exposed to low pressure whenspool valve member555 is in its downward position.

Regardless of the orientation ofspool valve member555, it should be appreciated thatpiston580 andplunger583 move toward their advanced positions whenhydraulic surface581 is exposed to high pressure actuation fluid. Whenpiston580 andplunger583 advance, fuel withinfuel injector530 is pressurized. Pressurized fuel can be blocked by secondelectrical actuator542 or directed to one of HCCInozzle control chamber609 or conventionalnozzle control chamber619. In other words, when secondelectrical actuator542 is in a first position, pressurized fuel is blocked from exitingfuel injector530 via eitherHCCI nozzle outlets626 orconventional nozzle outlets628. When secondelectrical actuator542 is in a second position, pressurized fuel can flow intoHCCI nozzle chamber609 via HCCInozzle supply passage608. When the pressure of fuel inHCCI nozzle chamber609 exceeds the downward force of biasingspring601, HCCIneedle valve member607 is lifted to its upward position. Pressurized fuel can now spray out offuel injector530 viaHCCI nozzle outlets626. When secondelectrical actuator542 is in a third position, pressurized fuel can flow intoconventional nozzle chamber619 vianozzle supply passage618. When the pressure of fuel inconventional nozzle chamber619 exceeds the downward force of biasingspring611, conventionalneedle valve member617 is lifted to its upward position allowing fuel spray intocylinder25 viaconventional nozzle outlets628.

Referring now toFIG. 14 there is illustrated a schematic representation of afuel injector530′ according to another control strategy.Fuel injector530′ includes a firstelectrical actuator532 and a secondelectrical actuator542′. Firstelectrical actuator532 is a two-position actuator that controls intensified injection viaconventional nozzles628. Secondelectrical actuator542′ is a two-position actuator that controls injection viaHCCI nozzles626. As with theFIG. 13 control strategy, firstelectrical actuator532 controls the pressure of hydraulic fluid acting on a control surface ofspool valve555. However, unlike theFIG. 13 embodiment, fuel injection viaHCCI nozzles626 is controlled only by fuel transfer pump pressure, as directed by secondelectrical actuator542′. Thus, when secondelectrical actuator542′ is de-activated, such as between HCCI injection events, openinghydraulic surface610 of HCCIneedle valve member607 is blocked fromfuel line20, and no injection viaHCCI nozzle outlets626 can occur. However, when secondelectrical actuator542′ is activated, openinghydraulic surface610 of HCCIneedle valve member607 is exposed to fuel pressure in fuel line20 (FIG. 1a), which is sufficient to move HCCIneedle valve member607 to its upward, open position to allow fuel injection viaHCCI nozzle outlets626. It should be appreciated that because fuel injected during the HCCI injection event is being supplied directly fromfuel line20, this will be a relatively low pressure injection event. In other words, because fuel for this injection event is being supplied directly fromfuel line20,needle valve member607 preferably has a relatively low valve opening pressure, such thatneedle valve member607 will be lifted to its open position against the spring bias force whennozzle chamber609 is fluidly connected to fuelline20.

Returning to firstelectrical actuator532, and the conventional injection event, when firstelectrical actuator532 is de-energized, such as between conventional injection events,spool valve member555 is in a first position fluidly connecting a hydraulic surface ofpiston580 to low pressure. In this condition,piston580 andplunger583 are in their retracted positions and fuel acting on openinghydraulic surface620 is not sufficient to move conventionalneedle valve member617 to its upward, open position. When firstelectrical actuator532 is energized, however,spool valve member555 is in a second position exposing the hydraulic surface ofpiston580 to high pressure, to allowpiston580 andplunger583 to move to their advanced positions to pressurize fuel withinfuel injector530′. When fuel pressure exceeds a valve opening pressure, conventionalneedle valve member617 is lifted to its open position and fuel injection viaconventional nozzle outlets628 can commence. The conventional valve opening pressure is thus preferably substantially higher than fuel transfer pressure.

Referring now toFIG. 15, there is illustrated yet another schematic representation of a control strategy forfuel injector530″. Note that in this embodiment, injection viaHCCI nozzle outlets626 is controlled by two-position actuator542′ as described for theFIG. 14 control strategy. However, this embodiment differs from theFIG. 14 embodiment in that conventionalneedle valve member617 now includes a closinghydraulic surface616 that is exposed to fluid pressure in a conventionalneedle control chamber612. Fluid pressure inneedle control chamber612 is controlled by firstelectrical actuator532. Thus, when firstelectrical actuator532 is de-energized, such as between conventional injection events, high pressure actuation fluid is applied to both a control surface onspool valve member555 and closinghydraulic surface616. Whilefuel injector530″ preferably utilizes oil as an actuation fluid, it should be appreciated that other fluids, such as fuel, could instead be used. Preferably,spool valve member555 is in a position exposinghydraulic surface581 ofpiston580 to low pressure when firstelectrical actuator532 is de-energized, thus preventing pressurization of fuel within fuel pressurization chamber85 (FIG. 2). In addition, however, it is preferable that closinghydraulic surface616 and biasingspring611 be sized and positioned such that conventionalneedle valve member617 will remain in, or move toward, its downward, closed position when closinghydraulic surface616 is exposed to high pressure, regardless whether the fuel pressure acting on openinghydraulic surface620 is at injection levels. When firstelectrical actuator532 is energized,spool valve member555 and closinghydraulic surface616 are exposed to low pressure. Once the pressure of fuel acting on openinghydraulic surface620 exceeds a valve opening pressure, fuel injection viaconventional nozzle outlets626 can commence. It should be appreciated that this injection event is a relatively high pressure injection event in comparison with the HCCI injection event, as with theFIG. 14 embodiment. In other words, because the fuel being injected viaconventional nozzle outlets628 has been pressure intensified bypiston580 andplunger583, the injection pressure of fuel being injected during the conventional injection event will be greater than the injection pressure of fuel being injected during the HCCI injection event, which is at a medium fuel supply pressure fromsource619, which could be a common fuel rail.

VII.FIGS. 16-18

Referring now toFIGS. 16-18, there is illustrated afuel injector630 according to yet another embodiment of the present invention, as well as anozzle valve assembly690 for use withfuel injector630. Once again,fuel injector630 preferably includes a number of components similar tofuel injector30, as illustrated inFIG. 2. For instance,fuel injector630 includes a firstelectrical actuator632 that controls fluid pressure in both avariable pressure passage667 and apressure communication passage688. As illustrated inFIG. 16, fluid pressure invariable pressure passage667 acts on a control surface ofspool valve member655, while fluid pressure inpressure communication passage688 acts on a closinghydraulic surface706 ofneedle valve member707. Preferably, firstelectrical actuator632 is a two-position actuator which controls the flow of pressurized engine lubricating oil to act on these components. However, it should be appreciated that firstelectrical actuator632 could be another suitable actuator, such as a piezo-electric actuator. In addition, it should be further appreciated that another suitable actuation fluid, such as fuel, could be used. When firstelectrical actuator632 is de-energized, such as between injection events,spool valve member655 is in a first position exposing ahydraulic surface681 of anintensifier piston680 to low pressure actuation fluid. In addition,pressure communication passage688 is open to high pressure actuation fluid, such that high pressure is acting on closinghydraulic surface706. When firstelectrical actuator632 is energized,spool valve member655 is moved to a second position in which high pressure actuation fluid can act onhydraulic surface681. When this occurs,piston681, as well as aplunger683, can move to advanced positions to pressurize fuel withinfuel injector630. Additionally, when firstelectrical actuator632 is energized, closinghydraulic surface706 is exposed to low pressure viapressure communication passage688.

Returning tofuel injector630, a secondelectrical actuator642 is included which controls fluid pressure acting on ahydraulic surface669 of astop component670, which is exposed to fluid pressure in astop control chamber671 viafluid transfer passage672. Secondelectrical actuator642 is also preferably a two-position actuator, however, once again another suitable actuator, such as a piezo-electric actuator, could be substituted. Preferably, secondelectrical actuator642 controls the flow of fuel from a fuel pressurization chamber85 (FIG. 2) to stopcontrol chamber671, however, another suitable actuation fluid could be utilized, such as pressurized engine lubricating oil. When secondelectrical actuator642 is de-energized, such as between injection events, stopcontrol chamber671 is open to low pressure viafluid transfer passage672. When low pressure is acting onhydraulic surface669,stop component670 is in a retracted position, as illustrated.Stop component670 is biased toward this retracted position by a biasingspring673. When secondelectrical actuator632 is energized, stopcontrol chamber671 is open to high pressure viafluid transfer passage672. When high pressure is acting onhydraulic surface669,stop component670 can move to an advanced position against the force of biasingspring673. As illustrated inFIG. 17, adrain passage675 is provided to allow evacuation of fluid that has migrated fromstop control chamber671 aroundstop component670.

Returning tonozzle assembly690, aneedle valve700 is provided that is preferably a three-position needle valve and includes a singleneedle valve member707.Needle valve member707 includes an openinghydraulic surface710 that is exposed to fuel pressure in anozzle chamber709 that is fluidly connected to fuelpressurization chamber85 via anozzle supply passage708. In addition,needle valve member707 defines a T-shapednozzle supply passage713, that can fluidly connectnozzle supply passage708 to either a set ofHCCI nozzle outlets726 or a set ofconventional nozzle outlets728, that are defined bytip795.Needle valve member707 is movable between a first, downward position (FIG. 18a), a second, maximum lift position (FIG. 18b), and a third, intermediate position (FIG. 18c). Whenneedle valve member707 is in its first position, as illustrated, it is out of contact withstop component670. Whenneedle valve member707 is in its second position, however, it is in contact withstop component670, which is in its retracted position. Similarly, whenneedle valve member707 is in its third position, it is also in contact withstop component670, which is in its advanced position.Needle valve member707 is preferably biased toward its first position by a biasingspring701. In addition, the relative sizes and strength of closinghydraulic surface706, openinghydraulic surface710 and biasingspring701 are preferably such thatneedle valve member707 will remain in its first position when closinghydraulic surface706 is exposed to high pressure fluid inneedle control chamber702, regardless of the pressure of fuel acting on openinghydraulic surface710.

Whenneedle valve member707 is in its downward, closed position, such as when firstelectrical actuator632 is de-energized,nozzle supply passage713 is blocked from fluid communication withnozzle supply passage708 due to the closure ofseat722 byvalve surface721. Thus, fuel injection via eitherHCCI nozzle outlets726 orconventional nozzle outlets728 is prevented. Whenneedle valve member707 is in its maximum lift position, such as when firstelectrical actuator632 is energized and secondelectrical actuator642 is de-energized to maintainstop component670 in its retracted position,HCCI nozzle outlets726 are open tonozzle supply passage708 vianozzle supply passage713. Whenneedle valve member707 is in its maximum lift position, this corresponds to a first configuration offuel injector630. Whenfuel injector630 is in this configuration, fuel spray intocylinder25 is at a relatively small angle θ with respect toinjector centerline629 andcylinder centerline27. As best illustrated inFIG. 18c,HCCI nozzle outlets726 are preferably defined such that θ is relatively small for this embodiment of the present invention. It should be appreciated fromFIG. 17 thatconventional nozzle outlets728 are briefly opened tonozzle supply passage708 via anannulus711 that is defined byneedle valve member707 whenneedle valve member707 is moving toward its maximum lift position.

Whenneedle valve member707 is in its intermediate lift position, such as when firstelectrical actuator632 is energized and secondelectrical actuator642 is energized such thatstop component670 is moved to its advanced position,annulus711 is open tonozzle supply passage708, such that fuel can spray out ofconventional nozzle outlets728 intocylinder25. However, whileneedle supply passage713 is open tonozzle supply passage708 whenneedle valve member707 is in this position,HCCI nozzle outlets726 remain blocked byneedle valve member707, such that fuel spray intocylinder25 viaHCCI nozzle outlets726 does not occur. Whenneedle valve member707 is in this intermediate lift position, this corresponds to a second configuration offuel injector630. Whenfuel injector630 is in this second configuration, fuel spray intocylinder25 is in a second spray pattern corresponding to the relatively large angle α ofconventional nozzle outlets128 with respect tocenterline629, as best illustrated inFIG. 18c.

Industrial Applicability

I.FIGS. 2-4

Referring toFIGS. 1-4, prior to an injection event,first actuator32 andsecond actuator42 are de-energized, low pressure infuel injector30 prevails at most locations andspool valve55 is in its upward position openingactuation fluid passage68 tolow pressure passage52, vialow pressure annulus58. With low pressure acting onhydraulic surface81,piston80 andplunger83 are in their retracted positions. HCCIneedle control chamber102 is exposed to high pressure viapressure communication passage88 such that HCCIneedle valve member107 is in its downward, closed position closingHCCI nozzle outlet126. Conventionalneedle valve member117 is in its downward biased position closingconventional nozzle outlets128.

Prior to the compression stroke ofpiston26,electronic control module17 evaluatesengine10 operating conditions to determine ifengine10 is operating in a conventional mode, an HCCI mode or a transitional mode.Engine10 can operate in a HCCI mode, such asunder a low load condition. In other words,injector30 will only perform an HCCI injection event, preferably at or near the beginning of the compression stroke ofpiston26. Ifengine10 is operating under a high load condition,injector30 will preferably operate in a conventional mode. In other words,injector30 will perform only a conventional injection, preferably at or near the end of the compression stroke ofpiston26. Finally, ifengine10 is determined to be operating under a transitional load condition,injector30 will operate in a mixed mode. Wheninjector30 is operating in the mixed mode, both an HCCI injection and the conventional injection will be performed during the compression stroke ofpiston26. In other words,injector30 will perform an HCCI injection whenpiston26 is relatively close to the bottom dead center position of its compression stroke and will then perform a conventional injection whenpiston26 is relatively close to the top dead center position of the same compression stroke. The remainder of operation of this embodiment ofinjector30 will be described for a transitional load operating condition ofengine10, corresponding to operation offuel injector30 in a mixed mode.

Referring toFIG. 2B, just prior to the beginning of the HCCI injection event, whenengine cylinder26 is relatively far from its top dead center position, firstelectrical actuator32 is energized andvalve member37 is moved upward by armature35 against the force of biasingspring33 to closehigh pressure seat39.Variable pressure passage67 andpressure communication passage88 are now fluidly connected tolow pressure passage40. With fluid pressure acting oncontrol surface65 inspool cavity65 now low, the high pressure acting onhigh pressure surface56 is sufficient to overcome the force of biasingspring60, andspool valve member55 moves to its advanced position blockingactuation fluid passage68 fromlow pressure passage52 and opening it tohigh pressure passage51 viahigh pressure annulus57. High pressure acting onhydraulic surface81 inactuation fluid passage68causes piston80 to begin to move toward its advanced position. Aspiston80 advances,plunger83 moves in a corresponding manner. This advancing movement ofpiston80 andplunger83 is sufficient to pressurize the fuel infuel pressurization chamber85 and HCCInozzle supply passage108 to injection levels.

Recall thatpressure communication passage88 is also open tolow pressure passage40, thus exposing closinghydraulic surface106 of HCCIneedle valve member107 to low pressure inneedle control chamber102. Therefore, once the pressure of fuel withinnozzle chamber109 exceeds an HCCI valve opening pressure, HCCIneedle valve member107 is lifted to its open position, corresponding to the first configuration offuel injector30.HCCI nozzle outlet126 is now fluidly connected tonozzle supply passage108 andnozzle chamber109. However, because high pressure fuel is acting on closinghydraulic surface116, conventionalneedle valve member117 remains in its downward, closed position. Pressurized fuel can now spray intocylinder25 viaHCCI nozzle outlet126. Referring again toFIG. 1a, recall that fuel will be sprayed intocylinder25 in a first spray pattern with respect tocylinder centerline27 whenfuel injector30 is injecting fuel viaHCCI nozzle outlet26. This fuel spray is preferably at a relatively small angle, here zero degrees, with respect tocylinder centerline27.

When the desired amount of fuel has been injected for the HCCI injection event, firstelectrical actuator32 is de-energized andvalve member37 is returned to its advanced position under the force of biasingspring33.Variable pressure passage67 andpressure communication passage88 are now opened tohigh pressure passage51. With high pressure acting on closinghydraulic surface106,needle valve member107 is returned to its closed position to blocknozzle outlet126 fromnozzle supply passage108 and end fuel spray intocylinder25.

Oncenozzle outlet126 is closed, residual high pressure inactuation fluid passage68 is sufficient to movepressure relief valve70 upward away fromseat72 to fluidly connectactuation fluid passage68 to pressurerelief passage75.Pressure relief valve70 can therefore help vent high pressure actuation fluid fromactuation fluid passage68 to prevent pressure spikes from causing undesired secondary injections. At the same time, the upward movement ofpressure relief valve70 causespin71 to aidspool valve member55 in returning to its upward position. Recall thatcontrol surface63 is again exposed to high pressure inspool cavity65, causingspool valve member55 to once again be hydraulically balanced such that it can return to its upward position under the force of biasingspring60, in addition to the upward force ofpin71. Whenspool valve member55 begins to retract,piston80 andplunger83 end their downward movement. However, as a result of hydraulic locking, they do not immediately begin to retract. Oncespool valve member55 is returned to its upward position,actuation fluid passage68 is blocked from fluid communication withhigh pressure passage51 and fluidly connected tolow pressure passage52, which further reduces the pressure withinactuation fluid passage68.Piston80 andplunger83 can now move toward their retracted positions. Asplunger83 retracts, fuel fromfuel source19 can be drawn intofuel pressurization chamber85 viafuel inlet86past check valve87. Used actuation fluid is displaced into thedrain52.

With the HCCI injection event now complete,piston26 continues to advance toward its top dead center position. Fuel and air withincylinder25 begin to combine into a homogeneous mixture. In addition,fuel injector30 prepares for the conventional injection event. Recall thatfuel injector30 will preferably only perform both the HCCI injection event and the conventional injection event during the same piston stroke whenengine10 is operating in a mixed mode, such as during a medium load condition. To initiate the conventional injection event, ascylinder piston26 approaches its top dead center position, secondelectrical actuator42 is energized andvalve member47 is moved to its retracted position byarmature45 to closehigh pressure seat49 and open conventionalneedle control chamber112 to relatively low pressure infuel line20 viapressure control line77. However, conventionalneedle valve member117 remains in its downward, closed position under the force of biasingspring111. Firstelectrical actuator32 is re-energized, andvalve member37 is once again moved to its retracted position by armature35 closinghigh pressure seat39.Spool cavity65 is again open tolow pressure passage40 viavariable pressure passage67. In addition,pressure communication passage88 is also opened tolow pressure passage40, thus exposing HCCI closinghydraulic surface106 to low pressure in HCCIneedle control chamber102. However, as with conventionalneedle valve member117, HCCIneedle valve member107 remains in its downward, closed position under the force of biasingspring101.

Whenspool cavity65 is opened tolow pressure passage40,spool valve member55 is no longer hydraulically balanced and is moved to its advanced position under the force of high pressure fluid acting onhigh pressure surface56.Actuation fluid passage68 is now open tohigh pressure passage51 viahigh pressure annulus57. With high pressure acting onhydraulic surface81 inactuation fluid passage68,piston80 andplunger83 begin to move toward their advanced positions. This movement, however raises the pressure of fuel withinfuel pressurization chamber85 andnozzle supply passage118 to injection pressure levels for the conventional injection event.

Once the pressure of fuel withinnozzle supply passage118 andnozzle chamber119 reaches the conventional valve opening pressure, which is less than the HCCI valve opening pressure, conventionalneedle valve member117 is lifted to its upward position to openconventional nozzle outlets128, corresponding to the second configuration offuel injector30. When conventionalneedle valve member117 is lifted, HCCIneedle valve member107 is also moved to its upward position. However, becauseneedle valve member107 is lifted withneedle valve member117, rather than being lifted away fromHCCI valve seat122,HCCI nozzle outlet126 remains blocked. HCCIneedle valve member107 is not lifted independently of conventionalneedle valve member117 because the conventional valve opening pressure heeded to lift conventionalneedle valve member117 to its upward position is lower than the valve opening pressure required to lift HCCIneedle valve member107 against the force of biasingspring101. Recall that the differing valve opening pressures is preferably a result of the difference in the preloads and strengths of biasingsprings101,111, as well as from a difference in the relative sizes of openinghydraulic surfaces110,120. In addition, once conventionalneedle valve member117 reaches its upward position, HCCIneedle valve member107 is prevented from lifting away fromHCCI valve scat122 bystop pin105. In order to ensure thatHCCI nozzle outlet126 remains closed during a conventional injection event, conventionalneedle valve member117 reaches its fully open position before fuel pressure reaches the HCCI valve opening pressure. Thus, fuel can spray intocylinder25 viaconventional nozzle outlets128, but not fromHCCI nozzle outlet126. Recall that this fuel injection occurs whencylinder piston26 is relatively close to its top dead center position. Referring again toFIG. 1b, recall that fuel injection viaconventional nozzle outlets128 occurs in a second spray pattern with respect tocylinder centerline27. As illustrated, this second spray pattern corresponds to fuel spray at a relatively large angle with respect tocylinder centerline27.

When the desired amount of fuel has been injected viaconventional nozzle outlets128, firstelectrical actuator32 is de-energized andvalve member37 is returned to its advanced position by biasingspring33 closinglow pressure seat38. This exposes closinghydraulic surface116 of conventional needle valve member to high pressure activation fluid. HCCIneedle control chamber102 remains open to high pressure fuel viapressure communication passage88. The downward force exerted onneedle valve members107 and117, by pressurized fuel inneedle control chamber102 pressured activation fluid inchamber112, and the biasing forces fromsprings101 and111, is sufficient to move HCCIneedle valve member107 and conventionalneedle valve member117 downward to their closed positions to end the injection event. Secondelectrical actuator42 remains de-energized to allowvalve member47 to return to its advanced position under the force of biasingspring43, opening conventionalneedle control chamber112 to high pressure incontrol supply line76 viacontrol pressure line77, thus exposing conventional closinghydraulic surface116 to high pressure.

Oncenozzle outlet126 is closed, residual high pressure inactuation fluid passage68 is sufficient to movepressure relief valve70 upward away fromseat72 to fluidly connectactuation fluid passage68 to pressurerelief passage75.Pressure relief valve70 can therefore help vent high pressure actuation fluid fromactuation fluid passage68 to prevent pressure spikes from causing undesired secondary injections. At the same time, the upward movement ofpressure relief valve70 causespin71 to aidspool valve member55 in returning to its upward position. Recall thatcontrol surface63 is again exposed to high pressure inspool cavity65, causingspool valve member55 to once again be hydraulically balanced such that it can return to its upward position under the force of biasingspring60, in addition to the upward force ofpin71. Whenspool valve member55 begins to retract,piston80 andplunger83 end their downward movement, however, as a result of hydraulic locking they do not immediately begin to retract. Oncespool valve member55 is returned to its upward position,actuation fluid passage68 is blocked from fluid communication withhigh pressure passage51 and fluidly connected tolow pressure passage52, which further reduces the pressure withinactuation fluid passage68.Piston80 andplunger83 can now move toward their retracted positions. Asplunger83 retracts, fuel fromfuel source19 can be drawn intofuel pressurization chamber85 viafuel inlet86past check valve87. Used actuation fluid is displaced into thedrain52.

Upon conclusion of the conventional injection event,engine10 prepares for the subsequent fuel injection event. Combustion incylinder25drives piston26 downward for its power stroke.Piston26 then performs its exhaust and intake strokes in preparation for the next injection event in a conventional manner.Electronic control module17 evaluates the operation condition ofengine10 to determine a desired mode of operation forfuel injector30 during the subsequent injection event. If the operating condition ofengine10 has changed,fuel injector30 could instead operate in either an HCCI mode or a conventional mode for the subsequent injection event.

II.FIG. 5

Referring now to theFIG. 5, operation offuel injector30 will be described for this alternate embodiment ofneedle valve200 for a mixed mode fuel injection event. Prior to an injection event, firstelectrical actuator32 is de-energized such thatvalve member37 is closinglow pressure seat38 and secondelectrical actuator42 is de-energized such thatvalve member47 is closinglow pressure seat48. Low pressure in most locations offuel injector30 prevails andspool valve member55 is in its upward position openingactuation fluid passage68 tolow pressure passage52 vialow pressure annulus58,piston80 andplunger83 are in their retracted positions, and HCCIneedle valve member207 and conventionalneedle valve member217 are in their respective downward closed positions. Aspiston26 begins to retract from its bottom dead center position of its compression stroke, the injection event is initiated.

To initiate the HCCI injection event, firstelectrical actuator32 is energized andvalve member37 is moved to closehigh pressure seat39 by armature35.Variable pressure passage67 andpressure communication passage88 are now fluidly connected tolow pressure passage40. With pressure inspool cavity65 now low, the high pressure acting onhigh pressure surface56 is sufficient to overcome the force of biasingspring60, andspool valve member55 moves to its advanced position blockingactuation fluid passage68 fromlow pressure passage52 and opening it tohigh pressure passage51 viahigh pressure annulus57. High pressure acting onhydraulic surface81 inactuation fluid passage68causes piston80 to begin to move toward its advanced position. Aspiston80 advances,plunger83 moves in a corresponding manner. It should be appreciated that becauseHCCI nozzle outlets226 are still closed,piston80 andplunger83 only advance a small distance at this time. However, this advancing movement ofpiston80 andplunger83 is sufficient to pressurize the fuel infuel pressurization chamber85 andnozzle supply passage218.

Recall thatpressure communication passage88 is also open tolow pressure passage40, thus exposing closinghydraulic surface206 of HCCIneedle valve member207 to low pressure inneedle control chamber202. Openinghydraulic surface210 is exposed to fuel pressure innozzle chamber209 which is fluidly connected tonozzle supply passage218 vianozzle supply passage208. Once the pressure of fuel withinnozzle chamber209 exceeds a valve opening pressure, HCCIneedle valve member207 is lifted to its open position, fluidly connectingHCCI nozzle outlets226 withnozzle supply passage208. Pressurized fuel can now spray intocylinder25 viaHCCI nozzle outlets226 in a first spray pattern with respect to cylinder centerline27 (FIG. 1a). Recall that this spray pattern corresponds to fuel spray at a small angle, with respect tocylinder centerline27. As Illustrated,piston26 is still relatively far from its top dead center position when this HCCI injection event occurs.

When the desired amount of fuel has been injected for the HCCI injection event, firstelectrical actuator32 is de-energized andvalve member37 is returned to its advanced position under the force of biasingspring33.Variable pressure passage67 andpressure communication passage88 are now opened tohigh pressure passage51. With high pressure acting on closinghydraulic surface206,needle valve member207 is returned to its closed position to blocknozzle outlets226 fromnozzle supply passage208 and end the injection event. At the conclusion of the HCCI injection event, various components offuel injector30 reset themselves in preparation for the next injection event, as described for the previous embodiment of the present invention. However, if a subsequent injection event is close in time, the injector may not reset itself.Piston80 andplunger83 return to their retracted positions and fuel is drawn intofuel pressurization chamber85 with the retracting movement ofplunger83 for the next injection event. In addition,piston26 continues to advance toward its top dead center position while fuel and air withincylinder25 begin to combine into a homogeneous mixture.

Recall that the HCCI injection event preferably occurs whilepiston26 is at or near bottom dead center position of its compression stroke. Whenengine10 is operating in a mixed mode condition,injector30 also performs a conventional injection event whenpiston26 is at or near its top dead center position. Just prior to the desired start of the conventional injection event, whenpiston26 is approaching its top dead center position, secondelectrical actuator42 is energized andvalve member47 is moved to closehigh pressure seat49 and open conventionalneedle control chamber212 to low pressure. Firstelectrical actuator32 is then re-energized andvalve member37 is moved to closehigh pressure seat39.Spool cavity65 is now re-opened tolow pressure passage40 viavariable pressure passage67. With low pressure acting oncontrol surface63, the high pressure acting onhigh pressure surface56 is sufficient to movespool valve member55 to its downward position.Actuation fluid passage68 is now blocked fromlow pressure passage52 and open tohigh pressure passage51 vialow pressure annulus58.

With high pressure again acting onhydraulic surface81,piston80 andplunger83 begin to move toward their advanced positions. However, becauseHCCI nozzle outlets226 andconventional nozzle outlets228 are closed,piston80 andplunger83 only move a slight distance. As with the HCCI injection event, this distance is sufficient to pressurize the fuel withinfuel pressurization chamber85,nozzle chamber209 andnozzle chamber219 to injection pressures. With low pressure now acting on closinghydraulic surface216, conventionalneedle valve member217 is raised to its open position once fuel pressure withinnozzle chamber209 exceeds its valve opening pressure. Recall that the various sizes and strengths of conventional openinghydraulic surface220, HCCI openinghydraulic surface210, conventional closinghydraulic surface216, HCCI closinghydraulic surface206,conventional biasing spring211 andHCCI biasing spring201 are preferably such that the conventional valve opening pressure will be reached before the HCCI valve opening pressure when low pressure is acting on both closinghydraulic surface206 and closinghydraulic surface216. In addition, recall that stoppin205 prevents HCCIneedle valve member207 from lifting away from conventionalneedle valve member217 once conventional needle valve member reaches its upward position. This will preventHCCI nozzle outlets226 from opening during the conventional injection event. Thus, whileHCCI needle valve207 will be lifted to its upward position when conventionalneedle valve member217 opens,HCCI nozzle outlets226 will remain closed because HCCIneedle valve member207 does not lift upward independently of conventionalneedle valve member217 to openvalve seat222.

Recall that fuel injection viaconventional nozzle outlets228 occurs in a second spray pattern with respect to cylinder centerline27 (FIG. 1b). This second spray pattern is at a relatively large angle with respect tocylinder centerline27. Once the desired amount of fuel has been injected for the conventional injection event, firstelectrical actuator32 is de-energized andvalve member37 is returned to its biased position closinglow pressure seat38. Oncepressure communication passage88 is open tohigh pressure passage51, the high pressure acting on HCCI closinghydraulic surface206, in combination with the respective forces of biasingsprings201 and211, is sufficient to move both HCCIneedle valve member207 and conventionalneedle valve member217 to their downward positions to end the injection event. It should be appreciated that injection viaHCCI nozzle outlets226 is not preferable during the conventional injection event. Therefore, the various hydraulic surfaces and biasing spring forces should be such that fuel forces exerted on conventionalneedle valve member207 will cause it to lift before HCCIneedle valve member217 is capable of lifting on its own. In addition, it should be appreciated that HCCI closinghydraulic surface206 should be exposed to high pressure prior to exposure of conventional closinghydraulic surface216 to high pressure, such that HCCIneedle valve member207 will return to its downward position concurrently with conventionalneedle valve member217.

Once the conventional injection event is ended, the various remaining components offuel injector30 reset themselves in preparation for the next injection event. Secondelectrical actuator42 is de-energized such that conventionalneedle control chamber212 is once again connected to high pressure. In addition, high pressure acting inspool cavity56, as a result of the de-activation of firstelectrical actuator32, allowsspool valve member55 to once again be hydraulically balanced and returned to its upward, biased position under the force of biasingspring60.Actuation fluid passage68 is open tolow pressure passage52, andpiston80 andplunger83 return to their retracted positions in a manner similar to that described for the previous embodiment.

III.FIGS. 6-7

Referring now toFIGS. 6 and 7, operation of this embodiment of the present invention will be described for a mixed mode injection event. Ifengine10 is operating under a low load condition,fuel injector230 will preferably operate in an HCCI mode, performing only an HCCI injection event during the compression stroke ofpiston26. Ifengine10 is operating under a high load condition,fuel injector230 will preferably operate in a conventional mode, performing only a conventional injection event during the compression stroke ofpiston26.

Prior to an injection event, low pressure prevails infuel injector230 andpiston280 andplunger283 are in their retracted positions. Firstelectrical actuator232 and secondelectrical actuator242 are de-energized, such that spool cavity256 is open to high pressure andspool valve member255 is hydraulically balanced and held in its upward, retracted position by biasing spring260. Additionally, high pressure is acting on closinghydraulic surface306 of HCCIneedle valve member307, and holding the same in its downward, closed position.

Just prior to the desired start of the HCCI injection event, whenpiston26 is returning from its bottom dead center position, firstelectrical actuator232 is energized. Low pressure now acts onspool valve member255, such thatspool valve member255 is no longer hydraulically balanced.Spool valve member255 then moves to its second position exposing hydraulic surface281 ofpiston280 to high pressure. Secondelectrical actuator242 is also energized to openneedle control chamber302 to low pressure. However, HCCIneedle valve member307 remains in its closed position at this point under the force of biasingspring301.

With high pressure now acting on hydraulic surface281,piston280 andplunger283 begin to move toward their advanced positions. BecauseHCCI nozzle outlet326 is still closed,piston280 andplunger283 advance only a slight distance. However,piston280 andplunger283 do travel a sufficient distance to raise the pressure of fuel within fuel pressurization chamber285,nozzle supply passages318,308 andnozzle chamber309 to injection pressure. When fuel pressure withinnozzle chamber309 is sufficient to overcome the downward force of biasingspring301,needle valve member307 is lifted to its upward position openingHCCI nozzle outlet326 to commence fuel spray intocylinder25 viaHCCI nozzle outlet326. Recall that the HCCI valve opening pressure ofneedle valve member307 is lower than the conventional valve opening pressure ofneedle valve member317, thus only HCCIneedle valve member307 will open at this time.

Fuel injection viaHCCI nozzle outlets326 occurs whenpiston26 is still relatively far from its top dead center position. Fuel spray intocylinder25 is in a first spray pattern with respect tocylinder centerline27. This first spray pattern corresponds to fuel spray at a relatively small angle, here zero degrees, with respect tocylinder centerline27. When the desired amount of fuel has been injected viaHCCI nozzle outlet326, firstelectrical actuator232 is de-energized. Closinghydraulic surface306 is again exposed to high pressure inneedle control chamber302. With high pressure now acting on closinghydraulic surface306, HCCIneedle valve member307 is returned to its downward, closed position blockingHCCI nozzle outlet326 and ending the injection event.Piston280 andplunger283 stop their downward movement, but do not retract as a result of continued high pressure acting on hydraulic surface281. Because the HCCI injection event resulted in injection of only a small amount of fuel, corresponding to plunger283 traveling less than a full stroke, a sufficient amount of fuel remains infuel injector230 to perform another injection event. It should be appreciated that these components could be allowed to reset if ample time is available before the next injection event. Further, recall that HCCIneedle valve member307 will return to its closed position, even with relatively high pressure fuel acting on openinghydraulic surface310 due to the relative size and strength of closinghydraulic surface306 and biasingspring301.

After the HCCI injection event,piston26 continues moving toward its top dead center position. The fuel that was injected during the HCCI injection event is mixing with air that was drawn intocylinder25 during the intake stroke ofpiston26 via the intake valve (not shown). Aspiston26 approaches its top dead center position,fuel injector230 prepares for the conventional injection event.Electrical actuator232 is again energized to initiate downward movement ofpiston280 andplunger283.Actuator242 remains de-energized to maintain high fluid pressure on closinghydraulic surface306 ofneedle307. Once the pressure of fuel withinnozzle chamber319 reaches a conventional valve opening pressure, conventionalneedle valve member317 is raised to its upward, open position, and fuel spray intocylinder25 viaconventional nozzle outlets328 can commence. Note that because high pressure is still acting on closinghydraulic surface306 of HCCIneedle valve member307, HCCIneedle valve member307 remains in its downward position with respect to conventionalneedle valve member317. In other words, while HCCIneedle valve member307 is moved upward by the upward movement of conventionalneedle valve member317,valve surface321 remains in contact withvalve seat322, and therefore,HCCI nozzle outlet326 remains blocked fromnozzle supply passage308.

Recall that fuel spray viaconventional nozzle outlets328 occurs in a second spray pattern with respect to cylinder centerline27 (FIG. 1b). This second spray pattern is at a relatively large angle with respect tocylinder centerline27. When the desired amount of fuel has been injected fromconventional nozzle outlets326, firstelectrical actuator232 is de-energized.Spool valve member255 is returned to its first position to expose hydraulic surface281 to low pressure.Piston280 andplunger283 once again end their advancing movement, but do not immediately return to their retracted positions as a result of residual high pressure acting onhydraulic surface231. Withpiston280 andplunger283 no longer advancing, fuel pressure innozzle supply passage318 andnozzle chamber319 begins to drop. When fuel pressure innozzle chamber319 falls below a valve closing pressure, conventionalneedle valve member317 is returned to its closed position to end the conventional injection event.

Once the conventional injection event has ended the various components offuel injector230 andengine10 again reset themselves in preparation for the next fuel injection event.Piston280 andplunger283 return to their retracted positions and fuel is drawn intofuel injector230 as a result of the retracting movement ofplunger283. If the operating condition ofengine10 changes,fuel injector230 could instead operate in either an HCCI mode or a conventional mode for the subsequent injection event.

IV.FIGS. 8-9

Referring now to theFIGS. 8 and 9 embodiment of the present invention, operation offuel injector330 will be described for a mixed mode injection event. As with the previous embodiment, it should be appreciated thatfuel injector330 could instead be operating in an HCCI mode or a conventional mode, such as in a low engine load condition or a high engine load condition, respectively.

Just prior to an injection event, HCCIneedle valve member407 and conventionalneedle valve member417 are in their downward positions closingHCCI nozzle outlet426 andconventional nozzle outlets428, respectively. To initiate an injection event, firstelectrical actuator332 is energized such that pressure acting on a control surface ofspool valve member355 is now low.Spool valve member355 moves to its second position exposinghydraulic surface381 to high pressure actuation fluid. High pressure acting onhydraulic surface381 causespiston380 to begin to move toward its advanced position. Aspiston380 advances,plunger383 moves in a corresponding manner. It should be appreciated that becauseHCCI nozzle outlet426 is still closed,piston380 andplunger383 only advance a small distance at this time. However, this advancing movement ofpiston380 andplunger383 is sufficient to pressurize the fuel withinfuel injector330 to injection levels.

When fuel pressure in nozzle supply passage408 exceeds the downward pressure exerted onneedle valve member407 by biasingspring401,needle valve member307 is lifted to its upward position to openHCCI nozzle outlet426 to nozzle supply passage408 vianozzle supply passage405. It should be appreciated that the HCCI valve opening pressure required to lift HCCIneedle valve member407 to its open position is preferably less than the force that would be required to lift conventionalneedle valve member417 against the downward force of both biasingspring411 and the hydraulic force acting on closinghydraulic surface416. Thus, conventionalneedle valve member417 remains in its closed position at this time. Recall that this HCCI injection event occurs aspiston26 is still relatively far from its top dead center position. Fuel spray for this HCCI injection event occurs in a first spray pattern with respect to cylinder centerline27 (FIG. 1a). This first spray pattern corresponds to a relatively small spray angle, here zero degrees, with respect tocylinder centerline27.

When the desired amount of fuel has been injected, firstelectrical actuator332 is de-energized andspool valve member355 is returned to its first position.Hydraulic surface381 is once again exposed to low pressure andpiston380 andplunger383 stop their advancing movement. However, residual high pressure acting onhydraulic surface381 prevents them from immediately returning to their retracted positions. Whilepiston380 andplunger383 are ending downward movement toward their advanced positions, pressure within nuzzle supply passage408 begins to decrease. When fuel pressure in nozzle supply passage408 no longer exceeds the downward pressure exerted by biasingspring401,needle valve member407 is returned to its downward, closed position blockingHCCI nozzle outlet426 from nozzle supply passage408 and ending the HCCI injection event.

After the HCCI injection event,piston26 continues moving toward its top dead center position. Fuel withincylinder25 mixes with air to create a homogeneous mixture. At this time, various components offuel injector330 reset themselves in preparation for the conventional injection event, assuming that sufficient time is available. Fuel for the next injection event is either already in the injector, or drawn intofuel injector330 by the retracting movement ofplunger383.

Aspiston26 approaches its top dead center position, and just prior to the start of the conventional injection event, secondelectrical actuator342 is energized. Low pressure actuation fluid is now acting on closinghydraulic surface416 of conventionalneedle valve member417. However, conventionalneedle valve member417 remains in its closed position under the force of biasingspring411. Firstelectrical actuator332 is re-energized andspool valve member355 begins to move toward its second position.Hydraulic surface381 is once again open to high pressure actuation fluid andpiston380 andplunger383 again begin to move toward their advanced positions to pressurize fuel withinfuel injector330. Once fuel pressure acting on openinghydraulic surface420 in nozzle supply passage408 exceeds a conventional valve opening pressure,needle valve member417 is moved to its upward position to openconventional nozzle outlets428. HCCIneedle valve member407 is lifted with conventionalneedle valve member417, howeverHCCI nozzle outlet426 remains closed becausevalve surface421 does not openvalve seat422. Recall that this is due to conventional valve opening pressure being less than the HCCI valve opening pressure when low pressure is acting on closinghydraulic surface416. In addition, recall that onceneedle valve member417 reaches is upward position,sleeve406 preventsneedle valve member407 from further upward movement. Thus, fuel spray viaconventional nozzle outlets428 commences while fuel spray viaHCCI nozzle outlet426 is prevented. Recall that this conventional fuel injection event occurs whenpiston26 is relatively close to its top dead center position and results in fuel spray intocylinder25 in a second spray pattern (FIG. 1b). This second spray pattern is at a relatively large angle with respect tocylinder centerline27, as illustrated.

When the desired amount of fuel has been injected byfuel injector330 viaconventional nozzle outlets428, firstelectrical actuator332 and secondelectrical actuator342 are de-energized. With high pressure now acting on closinghydraulic surface416 inneedle control chamber412,needle valve member417 returns to its downward position, blockingconventional nozzle outlets428 and ending the injection event. Once the injection event is over, the various components offuel injector330 begin to reset themselves in preparation for the next injection event.Piston380 andplunger383 return to their retracted positions and fuel for the subsequent injection event is drawn intofuel injector330 with the retracting movement ofplunger383. In addition,engine10 prepares for the subsequent fuel injection event as well.Piston26 performs its power stroke, as a result of combustion withincylinder25 following the conventional injection event, and then undergoes its exhaust and intake strokes, in a conventional manner.Electronic control module17 evaluates the operation condition ofengine10 to determine a desired mode of operation forfuel injector330 during the subsequent injection event.

V.FIGS. 10-11

Referring now to theFIGS. 10 and 11 embodiment of the present invention, operation offuel injector430 will be described for a mixed mode fuel injection event. It should be appreciated that this embodiment of the present invention can perform a mixed mode injection event at any desired operating condition. As with the previous embodiment, preferably only an HCCI injection will be performed whenengine10 is operating under a low load conditions.

Just prior to the desired start of the HCCI injection event, whenpiston26 is relatively far from its top dead center position,actuator442 is energized. Closinghydraulic surface506 ofneedle valve member507 is now exposed to low pressure actuation fluid inneedle control chamber502. With high pressure no longer holdingneedle valve member507 in its downward position, the pressure of fuel withinnozzle supply passage508 andnozzle chamber509, while being at medium fuel transfer pressure, is sufficient to liftneedle valve member507 to its upward position. Fuel can now spray out offuel injector430 viaHCCI nozzle outlets526. As fuel spray is occurring, fresh fuel is being drawn intofuel injector430 via a fuel inlet.

Recall that fuel spray viaHCCI nozzle outlets526 will occur in a first spray pattern with respect to cylinder centerline27 (FIG. 1a). This first spray pattern corresponds to a relatively small spray angle with respect tocylinder centerline27. When the desired amount of fuel has been injected viaHCCI nozzle outlets526, secondelectrical actuator442 is de-energized, and high pressure actuation fluid can once again act on closinghydraulic surface506.Needle valve member507 is then returned to its downward, closed position, and fuel injection viaHCCI nozzle outlets526 is ended.

Ascylinder piston26 advances toward its top dead center position, the fuel withincylinder25 mixes with the air contained therein to create a homogeneous mixture. Concurrently,fuel injector430 prepares for the conventional injection event. Just prior to the desired start of fuel injection, firstelectrical actuator432 is energized andspool valve member455 is moved to its second position exposinghydraulic surface481 ofpiston480 to high pressure actuation fluid.Piston480 andplunger483 thus begin to advance to pressurize fuel withinfuel injector430. When the pressure of fuel withinnozzle chamber519 is sufficient to overcome the force of biasingspring511 and the high pressure force acting on closinghydraulic surface506 ofneedle valve member507,needle valve member517 is lifted to its upward position. Fuel spray viaconventional nozzle outlets528 can now commence. However, with high pressure is still acting on closinghydraulic surface506,needle valve member507 will remain in its downward position with respect toneedle valve member517, such thatvalve surface521 continues to closevalve seat522 as a result of the differing valve opening pressures of the two needle valve members, which is preferably due to appropriate sizing of the various hydraulic surfaces and biasing strengths of the respective biasing springs. Thus,HCCI nozzle outlets526 will remain closed during the conventional injection event.

Fuel spray viaconventional nozzle outlets528 occurs in a second spray pattern with respect to cylinder centerline27 (FIG. 1b). This second spray pattern corresponds to a relatively large spray angle with respect tocylinder centerline27. When the desired amount of fuel has been injected viaconventional nozzle outlets528, firstelectrical actuator432 is de-energized andspool valve member455 is returned to its first position. With high pressure no longer acting onhydraulic surface481,piston480 andplunger483 end their advancing movement. Fuel pressure withinnozzle chamber519 then begins to drop, such that it is no longer sufficient to overcome the force of biasingspring511 and the hydraulic force acting on closing hydraulic surface516.Needle valve member517 then returns to its downward, closed position under the force of biasingspring511. In addition,needle valve member507 moves to its corresponding downward position under the hydraulic force exerted on closinghydraulic surface506.

Between injection events, the various components offuel injector430 reset themselves for the next injection event.Piston480 andplunger483 return to their retracted positions and fuel for the subsequent injection event is drawn intofuel injector430 with the retracting movement of these components. In addition,engine10 prepares for the subsequent fuel injection event as well.Piston26 performs its power stroke, as a result of combustion withincylinder25 following the conventional injection event, and then undergoes its exhaust and intake strokes, in a conventional manner.Electronic control module17 evaluates the operation condition ofengine10 to determine a desired mode of operation forfuel injector430 during the subsequent injection event.

VI.FIGS. 12-15

Referring now to theFIGS. 12 and 13 embodiment of the present invention, prior to an injection event, low pressure prevails infuel injector530. As with previous embodiments, operation offuel injector530 will be described for a mixed mode injection event, corresponding to mixed mode operation offuel injector530. However, it should be appreciated that ifengine10 is operating in a different condition,fuel injector530 might operate in an HCCI mode, performing only an HCCI injection event during the engine cycle. Similarly, ifengine10 is operating in still another condition,fuel injector530 will preferably operate in a conventional mode, performing only a conventional injection event during the engine cycle.

Prior to an injection event, firstelectrical actuator532 and secondelectrical actuator542 are de-energized and HCCIneedle valve member607 and conventionalneedle valve member617 are in their downward positions blocking fuel injection fromHCCI nozzle outlets626 andconventional nozzle outlets628, respectively. Just prior to a desired injection event, firstelectrical actuator532 is energized and a control surface ofspool valve member555 is exposed to low pressure.Spool valve member555 now moves to a position exposinghydraulic surface581 ofpiston580 to high pressure.Piston580 andplunger583 begin to move toward their advanced positions. Because secondelectrical actuator542 is still de-energized, fuel flow to HCCInozzle supply passage608 and conventionalnozzle supply passage618 is blocked and thereforepiston580 andplunger583 can only advance a slight distance. However, this slight movement is sufficient to raise the pressure of fuel withinfuel injector530 to injection pressure.

To initiate the HCCI injection event, whenpiston26 is relatively far from its top dead center position, secondelectrical actuator542 is moved to its first position, openingnozzle supply passage608 to pressurized fuel. As this pressurized fuel flows intonozzle chamber609 vianozzle supply passage608, it acts on openinghydraulic surface610 of HCCIneedle valve member607 and lifts the same to its open position. Fuel spray intocylinder25 viaHCCI nozzle outlets626 in a first spray pattern can now commence. Recall that this first spray pattern corresponds to a relatively small spray angle with respect to cylinder centerline27 (FIG. 1a). When the desired amount of fuel has been injected, secondelectrical actuator542 is de-energized, andnozzle supply passage608 is again blocked. With pressurized fuel no longer acting on openinghydraulic surface610,needle valve member607 is returned to its downward, closed position to end the injection event under the force of biasingspring601.

Just prior to the start of the conventional injection event, whencylinder piston26 is relatively close to its top dead center position, secondelectrical actuator542 is moved to its third position, openingnozzle supply passage618. Pressurized fuel can now act on openinghydraulic surface620 innozzle chamber619.Needle valve member617 is now lifted to its open position, and fuel spray viaconventional nozzle outlets628 can commence in a second spray pattern. Recall that this second spray pattern corresponds to a relatively large spray angle with respect to cylinder centerline27 (FIG. 1b).

To end the conventional injection event, secondelectrical actuator542 is again de-energized and fuel flow tonozzle chamber619 is ended. Conventionalneedle valve member617 is then returned to its downward, closed position under the force of biasingspring611. Fuel spray tocylinder25 viaconventional nozzle outlets628 is thus ended. Firstelectrical actuator532 is then de-energized, andspool valve member555 is returned to is first position exposinghydraulic surface581 to low pressure. Those skilled in the art will also recognize that injection events can also be ended by de-energizingactuator532 whileactuator542 remains energized.Piston580 andplunger583 end their advancing movement. Between injection events, the various components offuel injector530 once again begin to reset themselves in preparation for the subsequent injection event.Piston580 andplunger583 return to their retracted positions while drawing fresh fuelinjector fuel injector530 for the next injection event. In addition,engine10 prepares for the subsequent fuel injection event as well.Piston26 performs its combustion stroke, as a result of combustion withincylinder25 following the conventional injection event, and then undergoes its exhaust and intake strokes.Electronic control module17 evaluates the operation condition ofengine10 to determine the desired mode of operation forfuel injector530 during the subsequent injection event.

Referring now to theFIG. 14 embodiment of the present invention, fuel injection viaconventional nozzle outlets628 is similar to that in theFIG. 14 embodiment. However, in this embodiment, the HCCI injection event is controlled by fuel rail pressure via secondelectrical actuator542′. The HCCI injection event is initiated whenpiston26 is still relatively far from its top dead center position. To initiate the HCCI injection event, secondelectrical actuator542′ is activated andHCCI nozzle chamber609 is opened to a medium pressure fuel rail (not shown). The fuel acting on openinghydraulic surface610 of HCCIneedle valve member607 is at a medium level, however, it is sufficient to overcome the downward bias of biasingspring601. HCCIneedle valve member607 is then lifted and fuel spray intocylinder25 viaHCCI nozzle outlets626 can commence in a first spray pattern. Recall that this first spray pattern corresponds to a relatively small spray angle with respect to cylinder centerline27 (FIG. 1a). When the desired amount of fuel has been injected viaHCCI nozzle outlets626, secondelectrical actuator542′ is de-energized and the fuel rail is again blocked fromHCCI nozzle chamber609. HCCIneedle valve member607 is then returned to its downward position under the force of biasingspring601, and the HCCI injection event is ended.

Just prior to the desired start of the conventional injection event, whenpiston26 is relatively close to its top dead center position, firstelectrical actuator532 is energized andspool valve member555 is moved to its second position exposinghydraulic surface581 ofpiston580 to high pressure.Piston580 andplunger583 now begin moving toward their advanced positions. While these components can only move a slight distance becauseconventional nozzle outlets628 remain blocked, this movement is sufficient to raise the pressure of fuel withinfuel injector530 to injection pressure. When the pressure of fuel innozzle chamber619 exceeds the downward force of biasingspring611, conventionalneedle valve member617 is lifted to its upward position. Fuel spray intocylinder25 viaconventional nozzle outlets628 can commence in a second spray pattern. Recall that this second spray pattern corresponds to a relatively large spray angle with respect to cylinder centerline27 (FIG. 1).

When the desired amount of fuel has been injected viaconventional nozzle outlets628, firstelectrical actuator532 is de-energized.Spool valve member555 is now returned to its first position exposinghydraulic surface581 to low pressure.Piston580 andplunger583 end their downward movement, but do not immediately start their retracting movement as a result of residual high pressure exposed tohydraulic surface581. Once the pressure of fuel acting on openinghydraulic surface620 falls below the force of biasingspring611, conventionalneedle valve member617 is returned to its downward position to end fuel spray viaconventional nozzle outlets628.Engine10 prepares for the subsequent fuel injection event as well.Piston26 performs its combustion stroke, as a result of combustion withincylinder25 following the conventional injection event, and then undergoes its exhaust and intake strokes.Electronic control module17 evaluates the operation condition ofengine10 to determine the desired mode of operation forfuel injector530 during the subsequent injection event.

Referring now to theFIG. 15 embodiment of the present invention, recall that the HCCI injection event is carried out in a manner similar to that disclosed for theFIG. 14 embodiment. Therefore, only the conventional injection event will be described. Just prior to the desired start of the conventional injection event, firstelectrical actuator532 is energized andspool valve member555 is moved to its second position exposinghydraulic surface581 ofpiston580 to high pressure actuation fluid.Piston580 andplunger583 now move toward their advanced positions, pressurizing fuel infuel injector530″. In addition, activation of firstelectrical actuator532 also results in conventionalneedle control chamber612 being blocked from high pressure and being fluidly connected tolow pressure reservoir12. With low pressure acting on closinghydraulic surface616, fuel pressure acting on openinghydraulic surface620 is now sufficient to lift conventionalneedle valve member617 to its upward position. Fuel spray viaconventional nozzle outlets628 can now commence in the second spray pattern, as described for theFIG. 14 embodiment.

When the desired amount of fuel has been injected viaconventional nozzle outlets628, firstelectrical actuator532 is de-energized. Closinghydraulic surface616 is once again exposed to high pressure inneedle control chamber612. The downward force acting on conventionalneedle valve member617 is now sufficient to return conventionalneedle valve member617 to its downward, closed position. Withconventional nozzle outlets628 now blocked,piston580 andplunger583 end their downward movement. At about the same time,spool valve member555 is returned to its first position exposinghydraulic surface581 to low pressure. Between injection events,piston580 andplunger583 return to their retracted positions. The retracting movement ofplunger583 draws fuel intofuel injector530″ for the next injection event. In addition,engine10 prepares for the subsequent fuel injection event as well.Piston26 performs its power stroke, as a result of combustion withincylinder25 following the conventional injection event, and then undergoes its exhaust and intake strokes in a conventional manner.Electronic control module17 evaluates the operation condition ofengine10 to determine the desired mode of operation forfuel injector530 during the subsequent injection event.

VII.FIGS. 16-18

Referring now toFIGS. 16-18, operation offuel injector630 will now be described for a mixed mode injection event. Prior to the injection event, firstelectrical actuator632 and secondelectrical actuator642 are de-energized and spool valve member is positioned to exposehydraulic surface681 ofpiston680 to low pressure actuation fluid.Needle valve member707 is in its downward, closed position out of contact withslop component670. In addition, low pressure fuel is acting onhydraulic surface669 ofstop component670 such thatstop component670 is in its biased, retracted position. Just prior to the desired start of the HCCI injection event, whilepiston26 is relatively close to the bottom dead center position of its compression stroke, firstelectrical actuator632 is energized.

Once firstelectrical actuator632 is energized, closinghydraulic surface706 is exposed to low pressure inneedle control chamber702 viapressure communication passage688. In addition,spool valve member655 is moved to its second position exposinghydraulic surface681 ofpiston680 to high pressure actuation fluid.Piston680 andplunger683 now begin to advance to pressurize fuel withinfuel injector630. However, becauseHCCI nozzle outlet726 andconventional nozzle outlets728 remain closed at this time,piston680 andplunger683 advance only a slight distance. However, this slight advance is sufficient to raise the pressure of fuel within fuel pressurization chamber685 andnozzle supply passage708 to injection pressures. Once the fuel pressure acting on openinghydraulic surface710 exceeds the downward bias of biasingspring701,needle valve member707 is moved to its maximum lift position, in contact withstop component670, thus allowing fuel spray intocylinder25 viaHCCI nozzle outlets726 in a first spray pattern (seeFIG. 18b). Recall that this first spray pattern corresponds to a relatively small spray angle with respect to cylinder centerline27 (FIG. 1a). In addition, asneedle valve member707 is moving toward its maximum lift position,conventional nozzle outlets728 are briefly opened byannulus711, thus producing a short fuel spray viaconventional nozzle outlets728 intocylinder25.

When the desired amount of fuel has been injected viaHCCI nozzle outlets726, firstelectrical actuator632 is energized andhydraulic surface706 is exposed to high pressure inneedle control chamber702. The pressure inneedle control chamber702 along with the force of biasingspring701 moveneedle valve member707 to its advanced closed position.

If a conventional injection event is desired, bothactuators632 and642 are energized. Energization ofactuator632 acts to pressurize fuel ininjector630 as previously described. Energization ofactuator642 connectfluid transfer passage672 to high pressure actuation fluid to produce a high pressure force onsurface669 ofstop component670. This causes stop component to move downward against the action ofspring673. When fuel pressure exceeds the value opening pressure,needle valve member707 will lift into contact withstop component670 to assume its intermediate position as shown inFIG. 18c.

Needle valve member707 is now moved to its intermediate position, still in contact withstop component670, blockingHCCI nozzle outlets726 and openingconventional nozzle outlets728 viaannulus711. Fuel spray intocylinder25 viaconventional nozzle outlets728 can now commence in a second spray pattern. Recall that this second spray pattern corresponds to a relatively large spray angle with respect to cylinder centerline27 (FIG. 1b). When the desired amount of fuel has been injected viaconventional nozzle outlets728, firstelectrical actuator632 is de-energized.Pressure communication passage688 is once again open to high pressure actuation fluid. With high pressure again acting on closinghydraulic surface706,needle valve member707 is returned to its downward, closed position to end the injection event. Once the injection event has ended, various components offuel injector630 reset themselves for the next injection event. After fuel pressure drops,actuator642 can be de-energized. Withconventional nozzle outlets728 closed,piston680 andplunger683 end their advancing movement. However, they do not immediately begin to retract as a result of residual high pressure acting onhydraulic surface681. Withhydraulic surface669 again exposed to low pressure instop control chamber671,stop component670 can once again return to its retracted position under the force of biasingspring673.

It should be appreciated that a number of modifications could be made tofuel injector630 without departing from the spirit of this invention. For instance, secondelectrical actuator642 could be eliminated, and fuel pressure instop control chamber671 could be controlled by a fuel supply passage that is a portion ofnozzle supply passage708. In that instance, stopcomponent670 would remain in its upward position until fuel pressure withinstop control chamber671 is increased to a sufficient level to overcome the force of biasingspring673. At that point, stopcomponent670 would be moved to its advanced position, thus movingneedle valve700 to its intermediate position. In addition,stop component670 could be modified such that biasingspring673 biases stop component650 to its downward position. In that instance,fluid transfer passage672 could be a portion ofnozzle supply passage708 and could fluidly connect astop control chamber671 located below a shoulder portion ofstop component670. Here the high fluid pressure would act against the force of biasing spring to keepstop component670 in its upward position whileinjector630 was undergoing its HCCI injection event. As the pressure withinstop control chamber671 decreases over the injection event, the force of biasingspring673 becomes sufficient to overcome the force of fuel instop control chamber671. Once that fluid pressure force could be overcome, stopcomponent670 would be moved to its downward position under the force of biasingspring673, thus movingneedle valve member700 downward to its intermediate position. It should be appreciated that both of these alternative embodiments require the adjustment of fuel pressure over time during the injection event. In the first instance, fuel pressure must be able to increase over the injection event to allow the conventional injection event to occur. In the second instance, fuel pressure must be able to decrease over the injection event for the conventional injection event to occur. In addition to these modifications, it should be appreciated thatstop component670 need not be included in a fuel injector that has mixed mode capabilities. Rather, stopcomponent670 could be included in any nozzle assembly having a valve member that is movable to three positions.

It should be appreciated that a number of additional modifications could be made to the present invention, in addition to those illustrated and described herein. For instance, while only a hydraulically actuated fuel injector has been illustrated, it should be appreciated that a cam driven fuel injector could also benefit from use of the present invention. For instance, a fuel injector operating in conjunction with a two lobed cam could be modified to include any of the embodiment of the nozzle assembly described above. In addition, the nozzle assembly of the present invention could also be incorporated into a pump and line fuel injector. With minor modifications to the injector plumbing, the pump and line fuel injector could also operate as a dual mode fuel injector according to the present invention. For instance, while the present invention has been illustrated in the context of a hydraulically actuated fuel injector using oil as the actuation fluid, one skilled in the art will recognize that this invention is equally applicable to other fuel systems such as the single fluid amplifier piston common rail system (APCRS) illustrated in the paper “Heavy Duty Diesel Engines—The Potential of Injection Rate Shaping for Optimizing Emissions and Fuel Consumption”, presented by Messrs. Bernd Mahr, Manfred Dumholz, Wilhelm Polach and Hermann Grieshaber; Robert Bosch GmbH, Stuttgart, Germany, at the 21^stInternational Engine Symposium, May 4-5, 2000, Vienna, Austria. With some minor modifications, the Bosch APCRS system could be made in accordance with the present invention.

Those skilled in the art will recognize that all of the disclosed embodiments include a plurality of assembled components that define homogenous charge nozzle outlets and conventional nozzle outlets. These outlets may be defined by one or more body components, be defined by a needle valve member, or possibly be defined by a space between a body component and a valve member. With regard to the latter, a nozzle outlet according to the present invention could be an annular opening between an outwardly opening pin valve member and a body component. In addition, in all embodiments the homogenous charge and conventional nozzle outlets have different spray patterns.

It should be understood that the above description is intended for illustrative purposes only, and is not intended to limit the scope of the present invention in any way. For instance, while each of the fuel injectors have been illustrated having two separate actuators that are attached to the injector body, this is not necessary. One alternative to this would be the use of actuators positioned in the fluid lines that are not attached to the injector body. Further, these actuators could be either linear or rotary actuators. Thus, those skilled in the art will appreciate that other aspects, objects and advantages of this invention can be obtained from a study of the drawings, the disclosure and the appended claims.

Claims (70)

1. A nozzle assembly comprising:

a plurality of assembled components having a centerline and defining a plurality of nozzle outlets;

a homogenous charge compression ignition portion of said plurality of nozzle outlets including at least one nozzle outlet oriented at a first angle with respect to said centerline;

a conventional portion of said plurality of nozzle outlets including at least one nozzle outlet oriented at a second angle with respect to said centerline;

said assembled components including a needle valve being positioned to move between positions that open and close said plurality of nuzzle outlets, and being moveable between a first position in which said first portion are open but said second portion are closed, and a second position in which said second portion are open but said first portion are closed; and

at least one electrical actuator operably coupled to said needle valve

said needle valve including a first needle valve member with a first closing hydraulic surface and a second needle valve member with a second closing hydraulic surface; and

said first closing hydraulic surface is exposed to fluid pressure in a first needle control chamber and said second closing hydraulic surface is exposed to fluid pressure in a second needle control chamber

said first needle control chamber contains a first fluid and said second needle control chamber contains a second fluid that is different from said first fluid.

2. The nozzle assembly ofclaim 1 wherein said first angle is relatively small and said second angle is relatively large.

3. The nozzle assembly ofclaim 2 wherein said first angle is less than or equal to 30 degrees; and

said second angle is greater than or equal to 60 degrees.

4. The nozzle assembly ofclaim 1 wherein said second needle valve member is at least partially positioned within said first needle valve member.

5. The nozzle assembly ofclaim 4 wherein said first needle valve member includes a valve seat and said second needle valve member includes a valve surface;

a nozzle supply passage being blocked when said valve surface is in contact with said valve seat; and

said nozzle supply passage being open when said valve surface is out of contact with said valve seat.

6. The nozzle assembly ofclaim 1 wherein a nozzle body includes a first valve seat and a second valve seat; and

a number of said plurality of nozzle outlets are located between said first valve seat and said second valve seat.

7. The nozzle assembly ofclaim 1 wherein said needle valve includes a solitary needle valve member; and

said needle valve member defines a portion of at least one nozzle supply passage.

8. The nozzle assembly ofclaim 7 wherein said needle valve is movable to a first position in which said first portion of said plurality of nozzle outlets and said second portion of said plurality of nozzle outlets are blocked;

said needle valve is movable to a second position in which said first portion of said plurality of nozzle outlets is open; and

said needle valve being movable to a third position in which said second portion of said plurality of nozzle outlets is open.

9. The nozzle assembly ofclaim 1 wherein said homogenous charge portion and said conventional portion are mutually exclusive.

10. An engine having at least two modes of operation comprising:

an engine housing defining a plurality of cylinders;

a solitary fuel injector for each of said plurality of cylinders, each said fuel injector having at least one electrical actuator and including a tip at least partially positioned in one of said plurality of cylinders;

each said fuel injector having a first configuration for a homogeneous charge compression ignition mode of operation in which fuel is injected relatively early in a compression stroke when a piston is nearer a bottom dead center position than a top dead center position in a first spray pattern with a relatively small average angle to an injector centerline; and

each said fuel injector having a second configuration for a conventional mode of operation in which fuel is injected relatively late in a compression stroke when said piston is nearer said top dead center position than said bottom dead center position in a second spray pattern with a relatively large average angle to said injector centerline.

11. The engine ofclaim 10 wherein each said fuel injector includes a plurality of nozzle outlets disposed therein;

a first portion of said plurality of nozzle outlets being open when said fuel injector is in said first configuration; and

a second portion of said plurality of nozzle outlets being open when said fuel injector is in said second configuration.

12. The engine ofclaim 11 wherein each said fuel injector includes a needle valve that is biased toward a first position blocking said plurality of nozzle outlets;

said needle valve having a second position that opens said first portion of said plurality of nozzle outlets while blocking said second portion when said fuel injector is in said first configuration; and

said needle valve having a third position that opens said second portion of said plurality of nozzle outlets while blocking said first portion when said fuel injector is in said second configuration.

13. The engine ofclaim 11 wherein each of said first portion of said plurality of nozzle outlets are oriented at first angles with respect to a centerline of said cylinder;

each of said second portion of said plurality of nozzle outlets are oriented at a second angles with respect to said centerline; and

said first angles being different from said second angles.

14. The engine ofclaim 13 wherein said first angle is relatively small and said second angle is relatively large.

15. The engine ofclaim 14 wherein said first angle is less than or equal to 30 degrees; and

said second angle is greater than or equal to 60 degrees.

16. The engine ofclaim 10 wherein said needle valve includes a first needle valve member and a second needle valve member; and

the at least one electrical actuator includes a first electrical actuator being operably coupled to said first needle valve member and a second electrical actuator being operably coupled to said second needle valve member.

17. The engine ofclaim 10 wherein said fuel injector includes a first needle valve member and a second needle valve member;

said first needle valve member includes a first closing hydraulic surface exposed to fluid pressure in a first needle control chamber; and

said second needle valve member includes a second closing hydraulic surface exposed to fluid pressure in a second needle control chamber.

18. The engine ofclaim 17 wherein said first needle control chamber is fluidly isolated from said second needle control chamber.

19. The engine ofclaim 10 wherein said fuel injector includes a first needle valve member and a second needle valve member; and

said second needle valve member is at least partially positioned within said first needle valve member.

20. The engine ofclaim 19 wherein said first needle valve member includes a valve seat, said second needle valve member includes a valve surface;

a nozzle supply passage being blocked when said valve surface is in contact with said valve seat; and

said nozzle supply passage being open when said valve surface is out of contact with said valve seam.

21. The engine ofclaim 10 wherein said needle valve includes a solitary needle valve member; and

said needle valve member defines a portion of at least one nozzle supply passage

22. The engine ofclaim 21 wherein said needle valve includes a stop component positioned in said injector body and movable between a retracted position and an advanced position;

said needle valve member is out of contact with said stop component when said needle valve is in a first position;

said needle valve member being in contact with said stop component when said needle valve is in a second position; and

said needle valve member being in contact with said stop component when said needle valve is in a third position.

23. A method of operating an engine comprising the steps of:

providing an engine having an engine housing defining a plurality of engine cylinders, each of said engine cylinders including a piston;

positioning a solitary fuel injector for each of said plurality of engine cylinders, at least in part by positioning a tip of each said fuel injector at least partially within one of said engine cylinders;

if said fuel injector is operating in a homogeneous charge compression ignition mode, injecting fuel in a first spray pattern from said fuel injector when said piston is nearer a bottom dead center position than a top dead center position; and

if said fuel injector is operating in a conventional mode, injecting fuel in a second spray pattern from said fuel injector when said piston is nearer to said top dead center position than said bottom dead center position; and

at least one of the injecting steps includes energizing an electrical actuator of the fuel injector.

24. The method ofclaim 23 wherein said step of injecting fuel when said piston is nearer a bottom dead center position includes a step of opening a first portion of fuel injector nozzle outlets; and

said step of injecting fuel when said piston is nearer to said top dead center position includes a step of opening a second portion of said fuel injector nozzle outlets.

25. The method ofclaim 23 wherein said step of injecting fuel from said fuel injector when said piston is nearer a bottom dead center position includes a step of moving a needle valve from a first position to a second position; and

said step of injecting fuel from said fuel injector when said piston is nearer to said top dead center position includes a step of moving said needle valve to a third position.

26. The method ofclaim 23 wherein said step of injecting fuel when said piston is nearer a bottom dead center position includes a step of injecting fuel in a first spray pattern with respect to a centerline of said cylinder; and

said step of injecting fuel when said piston is nearer to said top dead center position includes a step of injecting fuel in a second spray pattern with respect to said centerline.

27. The method ofclaim 23 wherein said step of injecting fuel in a first spray pattern includes a step of injecting fuel at a relatively small average angle with respect to said centerline; and

said step of injecting fuel in a second spray pattern includes a step of injecting fuel at a relatively large average angle with respect to said centerline.

28. The method ofclaim 23 including a step of closing at least one fuel injector nozzle outlet at least in part by applying high pressure to a closing hydraulic surface of a needle valve member movably positioned in said fuel injector.

29. The method ofclaim 23 including the steps of operating said fuel injector in said homogeneous charge compression ignition mode when said engine is operating in a low load condition; and

operating said fuel injector in said conventional mode when said engine is operating in a high load condition.

30. The method ofclaim 23 including the step of operating said fuel injector in a mixed mode, at least in part by injecting fuel when said piston is relatively far from its top dead center position and injecting fuel when said piston is relatively close to its top dead center position in a same piston stroke.

31. A fuel injector comprising:

a plurality of assembled components having a centerline and defining a plurality of nozzle outlets;

a homogenous charge compression ignition portion of said plurality of nozzle outlets being oriented at a first average angle with respect to said centerline;

a conventional portion of said plurality of nozzle outlets being oriented at a second average angle with respect to said centerline;

said assembled components including at least one needle valve member being positioned adjacent said plurality of nozzle outlets;

said at least one needle valve member having a first position in which said homogenous charge portion is open but said conventional portion is closed, and a second position in which said conventional portion is open but said homogenous charge portion is closed;

said at least one needle valve member including a closing hydraulic surface exposed to fluid pressure in a needle control chamber;

said assembled components including at least one electrical actuator attached to said injector body; and

said assembled components also including a three-way needle control valve operably coupled to said electrical actuator, and being movable between a first position in which said needle control chamber is fluidly connected to a source of high pressure fluid but fluidly disconnected from a low pressure passage, and a second position in which said needle control chamber is fluidly connected to said low pressure passage but fluidly disconnected from said source of high pressure fluid.

32. The fuel injector ofclaim 31 wherein said first average angle is relatively small and said second average angle is relatively large.

33. The fuel injector ofclaim 32 wherein said first average angle is less than or equal to 30 degrees; and

said second average angle is greater than or equal to 60 degrees.

34. The fuel injector ofclaim 33 wherein said needle valve includes a first needle valve member and a second needle valve member.

35. The fuel injector ofclaim 34 wherein said second needle valve member is at least partially positioned within said first needle valve member.

36. The fuel injector ofclaim 35 wherein said first needle valve member includes a valve seal, said second needle valve member includes a valve surface;

a nozzle supply passage being blocked when said valve surface is in contact with said valve seat; and

said nozzle supply passage being open when said valve surface is out of contact with said valve seat.

37. The fuel injector ofclaim 36 wherein said first needle valve member includes a first closing hydraulic surface and said second needle valve member includes a second closing hydraulic surface; and

said first closing hydraulic surface is exposed to fluid pressure in a first needle control chamber and said second closing hydraulic surface is exposed to fluid pressure in a second needle control chamber.

38. The fuel injector ofclaim 37 wherein said first needle control chamber is fluidly isolated from said second needle control chamber.

39. A fuel injector comprising:

a plurality of assembled components having a centerline and defining a plurality of nozzle outlets;

a homogenous charge compression ignition portion of said plurality of nozzle outlets being oriented at a first average angle with respect to said centerline;

a conventional portion of said plurality of nozzle outlets being oriented at a second average angle with respect to said centerline;

said assembled components including at least one needle valve member being positioned adjacent said plurality of nozzle outlets;

said at least one needle valve member having a first position in which said homogenous charge portion is open but said conventional portion is closed, and a second position in which said conventional portion is open but said homogenous charge portion is closed;

said at least one needle valve member including a first needle valve member with a first closing hydraulic surface exposed to fluid pressure in a first needle control chamber, and a second needle valve member with a second closing hydraulic surface exposed to fluid pressure in a second needle control chamber;

said first needle control chamber contains a first fluid and said second needle control chamber contains a second fluid that is different from said first fluid.

40. An engine having at least two modes of operation comprising:

an engine housing defining a plurality of cylinders;

at least one common rail attached to said engine housing;

a solitary fuel injector for each of said plurality of cylinders, each said fuel injector having a tip at least partially positioned in one of said plurality of cylinders, and including a plunger that partially defines a fuel pressurization chamber;

each said fuel injector being fluidly connected to said at least one common rail;

each said fuel injector having a first configuration corresponding to a homogeneous charge compression ignition mode of operation in which fuel is injected in a first spray pattern with a small average angle with respect to an injector centerline relatively early in a compression stroke when a piston is nearer a bottom dead center position than a top dead center position; and

each said fuel injector having a second configuration corresponding to a conventional mode of operation in which fuel is injected in a second spray pattern with a large average angle with respect to said injector centerline relatively late in a compression stroke when said piston is nearer said top dead center position than said bottom dead center position.

41. The engine ofclaim 40 wherein each said fuel injector includes an injector body that defines a plurality of nozzle outlets:

a first portion of said plurality of nozzle outlets being open when said fuel injector is in said first configuration; and

a second portion of said plurality of nozzle outlets being open when said fuel injector is in said second configuration.

42. The engine ofclaim 41 wherein each said fuel injector includes a needle valve that is biased toward a first position blocking said plurality of nozzle outlets;

said needle valve having a second position that opens said first portion of said plurality of nozzle outlets when said fuel injector is in said first configuration; and

said needle valve having a third position that opens said second portion of said plurality of nozzle outlets when said fuel injector is in said second configuration.

43. The engine ofclaim 42 wherein said small average angle is less than or equal to 30 degrees; and

said large average angle is greater than or equal to 60 degrees.

44. The engine ofclaim 43 wherein said needle valve includes a first needle valve member and a second needle valve member; and

a first electrical actuator being operably coupled to said first needle valve member and a second electrical actuator being operably coupled to said second needle valve member.

45. The engine ofclaim 44 wherein said first needle valve member includes a first closing hydraulic surface exposed to fluid pressure in a first needle control chamber; and

said second needle valve member includes a second closing hydraulic surface exposed to fluid pressure in a second needle control chamber.

46. The engine ofclaim 45 wherein said first needle control chamber is fluidly isolated from said second needle control chamber.

47. The engine ofclaim 46 wherein said first needle valve member is at least partially positioned within said second needle valve member.

48. The engine ofclaim 47 wherein said second needle valve member includes a valve scat, said first needle valve member includes a valve surface;

a nozzle supply passage being blocked when said valve surface is in contact with said valve seat; and

said nozzle supply passage being open when said valve surface is out of contact with said valve seat.

49. The engine ofclaim 48 wherein said at least one common rail includes an amount of oil; and

each said fuel injector includes a fuel inlet fluidly connected to a source of fuel that is different from said oil.

50. A method of operating an engine comprising:

providing an engine having an engine housing defining a plurality of engine cylinders, each of said engine cylinders including a piston;

positioning a solitary fuel injector for each of said plurality of engine cylinders, at least in part by positioning a tip of each of said solitary fuel injectors at least partially within one of said engine cylinders;

if said fuel injector is operating in a homogeneous charge compression ignition mode, injecting fuel in a first spray pattern from said fuel injector when said piston is nearer a bottom dead center position than a top dead center position;

if said fuel injector is operating in a conventional mode, injecting fuel in a second spray pattern from said fuel injector when said piston is nearer to said top dead center position than said bottom dead center position; and

applying high pressure to a closing hydraulic surface of at least one needle valve member movably positioned in said fuel injector; and

at least one of the injecting steps includes energizing an electrical actuator of the fuel injector.

51. The method ofclaim 50 wherein said step of injecting fuel when said piston is nearer a bottom dead center position includes a step of opening a first portion of fuel injector nozzle outlets; and

said step of injecting fuel when said piston is nearer to said top dead center position includes a step of opening a second portion of said fuel injector nozzle outlets.

52. The method ofclaim 50 wherein said step of injecting fuel from said fuel injector when said piston is nearer a bottom dead center position includes a step of moving said at least one needle valve member from a first position to a second position; and

said step of injecting fuel from said fuel injector when said piston is nearer to said top dead center position includes a step of moving said at least one needle valve member to a third position.

53. The method ofclaim 50 wherein said step of injecting fuel when said piston is nearer a bottom dead center position includes a step of injecting fuel in a first spray pattern with respect to a centerline of said cylinder; and

said step of injecting fuel when said piston is nearer to said top dead center position includes a step of injecting fuel in a second spray pattern with respect to said centerline.

54. The method ofclaim 50 wherein said step of injecting fuel in a first spray pattern includes a step of injecting fuel at a relatively small angle with respect to said centerline; and

said step of injecting fuel in a second spray pattern includes a step of injecting fuel at a relatively large angle with respect to said centerline.

55. The method ofclaim 50 including the steps of operating said fuel injector in said homogeneous charge compression ignition mode when said engine is operating in a low load condition; and

operating said fuel injector in said conventional mode when said engine is operating in a high load condition.

56. The method ofclaim 50 including the step of operating said fuel injector in a mixed mode, at least in part by injecting fuel when said piston is nearer a bottom dead center position and injecting fuel when said piston is relatively close to its top dead center position in a same piston stroke.

57. A fuel injector comprising:

a plurality of assembled components having a centerline and defining a plurality of nozzle outlets;

a homogeneous charge subset of said plurality of nozzle outlets being oriented at a relatively small average angle with respect to said centerline;

a conventional subset of said plurality of nozzle outlets being oriented at a relatively large average angle with respect to said centerline;

said assembled components including at least one needle valve member movable between a first configuration in which said plurality of nozzle outlets are closed, a second configuration in which said homogeneous charge subset is open but said conventional subset is closed, and a third configuration in which said homogeneous charge subset is closed but said conventional subset is open;

said plurality of assembled components including a plunger that defines a portion of a fuel pressurization chamber that is fluidly connected to one of said homogeneous charge subset and said conventional subset when a portion of said plurality of nozzle outlets is open; and

said plurality of assembled components including an electronically operated pressure control valve and at least one electronically operated needle control valve.

58. The fuel injector ofclaim 57 wherein said plurality of assembled components include an intensifier piston operably coupled to said plunger.

59. The fuel injector ofclaim 57 wherein said needle control valve includes a three-way valve member trapped to move between a first seat and a second seat.

60. The fuel injector ofclaim 57 wherein said homogeneous charge subset and said conventional subset are mutually exclusive.

61. The nozzle assembly ofclaim 1 wherein said homogeneous charge compression ignition portion of said plurality of nozzle outlets is separated from said conventional portion of said plurality of nozzle outlets by a sealing member; and

said sealing member is continuously biased toward a position separating said homogeneous charge compression ignition portion of said plurality of nozzle outlets from said conventional portion of said plurality of nozzle outlets.

62. A method of operating an engine, comprising the steps of:

injecting fuel from a fuel injector via a first at least one nozzle outlet in a first spray pattern directly into an engine cylinder;

mixing the fuel with air in the cylinder;

combusting the fuel after the mixing step;

injecting additional fuel from the fuel injector via a second at least one nozzle outlet in a second spray pattern directly into the engine cylinder when a piston of the engine cylinder is nearer top dead center than bottom dead center; and

at least one of the fuel injecting step and the additional fuel injecting step includes energizing at least one electrical actuator of the fuel injector.

63. The method of claim 62 wherein the first at least one nozzle outlet has a relatively small average angle with respect to a centerline; and

the at least one second nozzle outlet has a relatively large average angle with respect to the centerline.

64. The method of claim 62 wherein the at least one electrical actuator includes a first electrical actuator and a second electrical actuator;

the step of injecting fuel includes energizing the first electrical actuator; and

the step of injecting additional fuel includes energizing the second electrical actuator.

65. The method of claim 62 wherein the step of injecting fuel in the first spray pattern occurs during a compression stroke.

66. A nozzle assembly comprising: a plurality of assembled components defining a plurality of nozzle outlets;

a homogenous charge compression ignition portion of said plurality of assembled outlets being oriented at a first average angle with respect to a centerline;

a conventional portion of said plurality of nozzle outlets being oriented a second average angle with respect to said centerline;

said assembled components including a needle valve being positioned to move between positions that open and close said plurality of nozzle outlets, and being moveable between a first configuration in which said first portion are open but said second portion are closed, and a second configuration in which said second portion are open but said first portion are closed;

said assembled components also including at least one control valve member positioned to move between a high pressure seat and a low pressure seat; and

said assembled components further including at least one electrical actuator operably coupled to said needle valve via said at least one control valve member.

67. The nozzle assembly of claim 66 wherein said first average angle is relatively small and said second average angle is relatively large.

68. The nozzle assembly of claim 66 wherein at least one of a first needle valve member and a second needle valve member of the needle valve includes a closing hydraulic surface exposed to fluid pressure in a needle control chamber.

69. An engine having at least two modes of operation comprising: an engine housing defining a plurality of cylinders;

a solitary fuel injector for each of said plurality of cylinders, each said fuel injector having a tip at least partially positioned in one of said plurality of cylinders;

each said fuel injector having a first configuration for a homogeneous charge compression ignition mode of operation in which fuel is injected in a first spray pattern; and

each said fuel injector having a second configuration for a conventional mode of operation in which fuel is injected in a second spray pattern; and

each said fuel injector including at least one control valve member positioned to move between a high pressure seat and a low pressure seat.

70. A fuel injector comprising:

a plurality of assembly components having a centerline and defining a plurality of nozzle outlets;

a homogenous charge compression ignition portion of said plurality of nozzle outlets being oriented at a first average angle with respect to said centerline;

a conventional portion of said plurality of nozzle outlets being oriented at a second average angle with respect to said centerline;

said assembled components including at least one needle valve member being positioned adjacent said plurality of nozzle outlets;

said at least one needle valve member having a first position in which said homogenous charge portion is open but said conventional portion is closed, and a second position in which said conventional portion is open but said homogenous charge portion is closed;

said at least one needle valve member including a closing hydraulic surface exposed to fluid pressure in a needle control chamber;

said assembled components includes at least one control valve member positioned to move between a high pressure seat and a low pressure seat; and

said assembled components further includes at least one electrical actuator.

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