US2984232A - Fuel injection control - Google Patents

Description

May 16, 1961 D. N. ARNDT EIAL FUEL INJECTION CONTROL 3 Sheets-Sheet 2! Filed March 26, 1959 [Kl/67520715" Donald M Qrncii Etna? J. .Dahl

Gfimyefi LczMcwiers 1 Charles Z'dffag 2 2 6'. a

Fl/fL TANK L y 1961 D. N. ARNDT ETAL 2,984,232

FUEL INJECTION CONTROL Filed March 26, 1959 3 Sheets-Sheet 8 RN Rw fnz/eni rs .Domld 6772.037. final? 5 DQfLZ @6071'962 Laffczaiers 1 Charles ZZZ Nagy United States Patent 1 2,984,232 FUEL INJECTION CONTROL Donald N. Arndt, Einar S. Dahl, George D. La Masters,

and Charles W. May, all of Decatur, Ill., assignors to Borg-Warner Corporation, Chicago, Ill., a corporation of Illinois Filed Mar. 26, 1959, Ser. No. 802,251 18 Claims. (Cl. 123-179) This invention relates to a control system for a fuel injection mechanism adapted to be used with the engine of an automotive vehicle.

It is an object of the present invention to provide an improved control system for a fuel injection pump adapted to provide the correct amount of fuel to meet engine demand or the correct fuel to air ratio for all conditions of operation of the engine.

In particular, it is an object to provide an improved fuel injection control system for a fuel injection pump that supplies metering forces to the injection pump in accordance with engine demand for measuring each charge of fuel supplied to the engine cylinders.

It is a more particular object to provide metering forces to a fuel injection control mechanism, one of the forces being developed by manifold vacuum supplied from the air intake manifold, which vacuum is modified by adjustable air bleed or bypass means for adjusting engine idling conditions.

It is another object to provide an additional improved air bleed mechanism for modifying the manifold vacuum supplied to the control mechanism automatically in accordance with changes of temperature of the engine, particularly during engine warm-up.

It is still another object to provide an improved warmup control valve including a tapered needle element which is acted upon by a thermostatic element and by manifold vacuum, which needle element is effective to bleed or bypass a small amount of air into the manifold vacuum line of the control mechanism for modifying the manifold vacuum in accordance with engine warm-up temperature conditions and varying load conditions.

It is an object to provide optional electrically operated switch means interconnected with said air bleed mechanism for supplying additional starting fuel when the engine is comparatively cold.

It is another object to provide additional fuel enrichment for starting of the engine, the amount of starting fuel being automatically controlled in accordance with engine temperature.

It is an additional object to provide a fuel injection control system that is independent of the force of gravity for its operation and consequently can be mounted in any position with respect to the engine.

It is still another object to provide an improved com puter mechanism adapted to transform metering forces supplied from the engine into mechanical motion for metering each charge of fuel supplied by the fuel injection pump.

It is a more particular object to provide a computer mechanism having a two-dimensional cam which is acted upon by a vacuum motor for metering the charges of fuel in accordance with engine load conditions, and also including an atmospheric pressure responsive device for automatically modifying the position of said cam in accordance with changes in atmospheric pressure.

In addition to the preceding object, it is an object to provide vacuum operated power amplifying means that is responsive to atmospheric pressure for moving the cam.

More particularly, it isan object to provide a double diaphragm arrangement acted upon by manifold vacuum, an expansible bellows responsive to atmospheric pressure, a sliding valve mechanism connected to the bellows, and a lever mechanism connected with the diaphragm arrangement for automatically repositioning the bellows with changes in atmospheric pressure. i

The invention consists of the novel constructions, arrangements, and devices to be hereinafter described and claimed for carrying out the above stated objects and such other objects as will appear from the following description of a preferred form of the invention, illustrated with reference to the accompanying drawings, wherein:

Fig. 1 is a schematic diagram of the control and fuel supply system of the present invention, including a fuel injection pump, a computer mechanism, a throttle body, and a warm-up enrichment valve;

Fig. 2 is an enlarged sectional view showing details of constructions of the computer mechanism of Fig. 1;

Fig. 3 is a cross-sectional view of the throttle body taken online 33 of Fig. 1;

Fig. 4 is an enlarged sectional view of the improved warm-up valve taken on line 44 of Fig. l; and

Fig. 5 is a view of the control linkage for the throttle body, and includes a modified version of the starting fuel supply system.

Like characters of reference designate like parts in the several views.

Referring to Fig. 1, there is illustrated a schematic diagram of the complete control system for afuel injection pump 10. The system includes acomputer mechanism 11, athrottle body 12, a warm-up enrichment valve 13, a solenoid operated starting valve 14, a starting fuel regulator valve 15, and a fuelpressure regulator valve 16.

The fuel supply system for thepump 10 also includes afuel tank 17, a primaryfuel supply pump 18, and afilter 19, which are connected through aconduit 20 to animput port 21 of thepump 10.

Thesupply pump 18 is preferably electrically driven and supplies fuel under pressure to thepump 10 whenever the engine ignition switch is on.

Theinjection pump 10 supplies metered charges of fuel in sequence to a plurality ofnozzles 22 mounted in or adjacent to the cylinders of the internal combustion engine. Each of thenozzles 22 is connected by means of aconduit 23 to an outlet port 24 of thepump 10. Ametering control arm 25 is mounted on thepump 10 and is operated by thecomputer mechanism 11, for metering each charge of fuel delivered by thepump 10.

Thepump 10 is driven through a rotatable drive shaft 24 which is connected to be driven at a fixed speed ratio with respect to the crankshaft of the internal combustion engine.

Thepump 10 may be of the type described in copending application of Einar S. Dahl, entitled Fuel Injection Pump, Serial No. 791,081, filed February 4, 1959, and will not be further described.

The fuel supply system also includes an auxiliaryfuel supply line 26 connected to aport 27 of thepump 10, and a leakagefuel return line 28 which is connected to aport 29 of thepump 10. Theauxiliary supply line 26 is connected through thepressure regulator valve 16 to theleakage return line 28 which returns fuel back to thetank 17.

Thepressure regulator valve 16 comprises ahollow casing portion 30 formed with aninlet port 31 and an outlet port 32, aball 33, and a spring 34. Theinlet port 31 is connected to theconduit 26 and the outlet port 32 is connected to theconduit 28. The spring 34 tends to force theball 33 into a fluid sealing position against theinlet port 31, and functions to maintain the pressure within theconduit 26 at predetermined maximum.

The starting fuel regulator valve 15 comprises 2.casing 40 formed with aninlet port 41 and anoutlet port 42, avalve stem 43, a temperature responsive element 44, and aspring 45. Theinlet port 41 is connected at a point above therestriction 70.

through abranch conduit 46 to theauxiliary supply line 26. Thevalve stem 43 is attached to the temperature responsive element 44 and is positioned within the eas- "ing 40 so as to partially restrict theinlet port 41. The

valve stem 43 is formed with asmall passage 47 which always permits a minimum amount of fuel to flow from theport 41 to theport 42. Thespring 45 tends to lift thevalve stem 43 away from theinlet port 41. The temperature responsive element 44 is mounted within the casing 40' and extends into aliquid conduit 48 which is connected to the engine liquid cooling system. The temperature responsive element 44 may be of the Vernitherm type manufactured by Detroit Controls, Inc. The element 44 responds to the temperature of the cooling liquid so that thevalve stem 43 tends to open the port 41 a greater amount when the engine is cold and to restrict theport 41 to a greater extent when the engine is warm, thereby providing the correct amount of additional startingfuel for any given engine temperature.

The solenoid-operated starting valve 14 comprises acasing 50 formed with aninlet port 51 and an outlet port 52, asolenoid 53, a valve armature 54, and aspring 55. Theinlet port 51 is connected through aconduit 56 to theoutlet port 42 of the regulator valve 15. The outlet port 52 opens into achannel 57 which terminates atjets 58 formed in thethrottle body 12. Thespring 55 forces the valve armature 54 into a fluid sealing position against the outlet port 52 except when thesolenoid 53 is energized. Thesolenoid 53 is connected in series with the starting circuit of the engine.

In operation, the auxiliary fuel supply system for the fuel injection pump functions as follows:

When the ignition switch for the engine is turned on, the electrically drivensupply pump 18 delivers fuel from thetank 17 to the inlet port 2-1 of thefuel injection pump 10. A portion of this fuel is also supplied through theport 27 andconduit 26 to theinlet port 41 of the regulator valve 15. Fuel under pressure passes through theoutlet port 42 to theinlet port 51 of the starting valve 14. When the starting switch is closed, thesolenoid 53 is energized and opens the valve armature 54, allowing fuel to pass through the port 52,conduit 57, andjets 58 into the air stream of thethrottle body 12. The amount of fuel so passing through thejets 58 for starting is determined by the valve which, as previously stated, is responsive to the temperature of the liquid present within theconduit 48.

Thecomputer mechanism 11 comprises acasing 60 formed with an inlet port ororifice 61 which is connected through aconduit 62 to anorifice 63 formed in thethrottle body 12. Thecasing 60 also has a port ororifice 64 which is connected through aconduit 65 to anorifice 66 formed in the warm-upenrichment valve 13. Theconduit 65 is also connected by means of abranch conduit 67 to anorifice 68 formed in thethrottle body 12.

Theorifice 68 constitutes a bleed orifice and is adapted to be restricted by means of aneedle valve 69 threaded in the wall of thethrottle body 12. Theconduit 62 is formed with arestriction 70 at a point near theport 61. Thecasing 60 is also formed with aport 71 which is connected by means of a conduit 72fto theconduit 62 Theconduits 62, 65, and .72 are allsubjected to pressure existing within theintake manifold 73 of the engine.

Referring to Fig. 2, thecomputer mechanism 11 in general comprises a two-dimensional cam 80, a vacuum operatedservo motor 81 and anatmospheric pressure compensatingdevice 82. Theservo motor 81 comprises a diaphragm 83- mounted within acasing portion 60a and aspring 84. Thediaphragm 83 is connected to the "washer 86 and aspring retaining cup 87 which are attached to the connecting rod 85 by means of a nut 88. An

extension 89 of" the connecting rod 85 is guided within acylindrical cavity 90 formed in one end of thecasing portion 60a. Thespring 84 tends to force thediaphragm 83 to the right as shown in the figure. The motion of thediaphragm 83 to the right is limited by means of an annular abutment 'orcasing portion 91 formed within thecasing 60. Theports 61 and 64 open into the interior of the.casing portion 60a, and the diaphragm 8-3 is subjected to the pressure existing within theconduits 62 and 65.

Thecam 80 is formed with a slantingcam surface 92 and with pivot or contact points 93 and 94. Thecam 80 is formed with aslot 95 and is attached to the connecting rod 85 by means of apin 96 extending through theslot 95. A roller orcam follower 97 is in contact with thecam surface 92 and is carried by aroller arm 98 whichis pivotally mounted on apin 99 within thecasing 60. Thecontrol arm link 100 in turn acts against thecontrol arm 25 mounted on the exterior of thepump 10 which in turn acts against a metering pin or element within the pump 10 (not shown). Aspring 101 is disposed under com pression between thecasing 60 and thecontrol arm 25 and acts to reduce the force reflected back to theroller arm 98 from thepump 10.

Alever arm 102, designated as the low load guide arm, is pivotally mounted on apin 103 within thecasing 60. Thecontact point 93 of thecam 80 is in sliding contact with a surface 104cm theguide arm 102. An adjustingscrew 105 is attached to theguide arm 102 and extends through the wall of thecasing 60 and functions to adjust the initial position of theguide arm 102.

An L-shapedlever arm 106 is pivotally mounted upon apin 107 within thecasing 60 and is designated generally as the high load guide arm. Thecontact point 94 is in sliding contact with asurface 108 on theguide arm 106. Theguide arm 106 also carries a knuckle 109 which is in contact with a connectingrod 110 attached to thepressure compensator 82. The connectingrod 110 abuts against apin 111 mounted within thecasing 60, and is formed with awedge surface 112 in contact with the knuckle 109.

Thealtitude compensating mechanism 82, in general, comprises a casing portion attached to thecasing 60, an expansible bellows 121, two vacuumresponsive diaphragms 122 and 123, and a slidingvalve mechanism 124. The bellows 121 is carried by acentral shaft 125, one end of which is pivotally attached by means of apin 126 to one end of alever arm 127, called the repositioning lever. The other end of thelever arm 127 is pivotally attached to the connectingrod 110 by means of a pin 128. Thelever arm 127 is pivotally mounted on a fulcrum by means of apin 129. The other end of the shaft is pivotally attached to alever arm 130, called the co'ntrol valve lever, by means of a pin-131. Thelever 130 is pivoted on apin 132 and the other end thereof is pivotally attached to a sliding valve block 133 by means of apin 134.

Thediaphragms 122 and 123 are attached to the connectingrod 110 and are mounted in cavities and 141, respectively, formed in thecasing portion 120, and separated by a partition 142. Thediaphragm 122 separates thecavity 140 into two parts designated as 140a and 14012. Similarly, thediaphragm 123 separates thecavity 141 into two compartments designated as 141a and 141b. Theport 71, which is formed through the wall of thecasing portion 120, opens into both of thecompartments 140a and 141a. The compartments 14012 and 141b are both open to atmospheric pressure through ports 143 and 144, respectively.

The slidingvalve 124 comprises the sliding blo'ck 133 which is attached to thelever arm 130, a slidingplate 150, and afixed plate 151. The sliding plate is formed with a central port oropening 152 and is attached to the block 133 by means of aspring washer 153. A piece of felt 154 covers theopening 152 and prevents entry of-dirt therein. The .fixedplate 151 is, formed with twoopenings 155 and 156 with which theport 152 is adapted to communicate at times. Twocross-over channels 157 and 158 are formed through thecasing portion 120 and terminates at theopenings 155 and 156. Thechannel 157 connects thecavity 140a with theport 156 and thechannel 158 connects thecavity 141a with theport 155.

Referring to Fig. 3, thethrottle body 12 is mounted on theair intake manifold 73, and comprisescontiguous casing portions 160 and 161, a choke valve orvalves 162, and a plurality ofthrottle valves 163 and 164. Thechoke valves 162 are attached to ashaft 165 which is rotatably mounted through the walls of thecasing portion 160. Thethrottle valves 163 and 164 are attached toshafts 166 and 167, respectively, which are rotatably mounted through the walls of thecasing portion 161. Theshafts 166 and 167 are interconnected through a suitable mechanical linkage as shown in Fig. 5. Thecasing portion 160 is formed with thejets 58 which open into the air stream at a point below thechoke valves 162, and is also formed with anorifice 168 which opens into the air stream above thechoke valve 162. Thecasing portion 161 is formed with theorifice 63 which opens into the air stream at a point below thethrottle valve 163 so as to be subject to manifold vacuum. Thebleed orifice 63 opens into the air stream at a point substantially parallel with an edge of thethrottle blade 163 in a closed throttle position.

Referring to Fig. 4, the warm-upenrichment valve 13 comprises acasing 170, athermostatic element 171 and a tapered or needlevalve piston assembly 172. Thethermostatic element 171 is disposed within acavity 173 formed in thecasing 170, and one end thereof is connected to thevalve piston 172 through a bell crank 174 and a link 175. The other end of thethermostatic element 171 is attached to the interior of acover 176 mounted over thecavity 173. Thecover 176 is rotatably mounted on thecasing 170 for adjusting the tension of the thermostatic element'171. Thebell crank 174 is rigidly attached to one end of thechoke valve shaft 165.

Thevalve piston assembly 172 is formed with asmall land 177 and alarge land 178, a tapered orneedle portion 179, and a flaredportion 180. Thelands 177 and 178 are interconnected by the taperedportion 179 and are slidably disposed within co-linearcylindrical cavities 181 and 182, respectively, formed in thecasing 170. Thecylindrical cavities 181 and 182 are separated by means of awasher 183 which carries an ring 184. The O ring 184 serves as a valve seat for the flaredportion 180 of thevalve piston 172. Thecasing portion 170 is formed with theorifice 66 which opens into thecylindrical cavity 182 and with anorifice 185 which opens into thecylindrical cavity 181. Theorifice 185 is connected through achannel 186 to the orifice 168' in thethrottle body 12.

Thecasing 170 is also formed with anorifice 190 which opens into thecavity 173 and which is connected through aconduit 191 to a manifold stove (not shown), mounted in the exhaust manifold of the engine. The manifold stove may be of the type conventionally used with the automatic chokes of existing vehicles. Thecasing 170 is also formed with anorifice 192 which opens into thecavity 173 and which is connected through aconduit 193 to theair intake manifold 73.

Theconduit 193 connected to theair intake manifold 73 functions to draw air from thecavity 173 and atmospheric pressure forces air heated by the manifold stove through theconduit 191 andport 190 into thecavity 173. The air heated by the manifold stove acts on thethermostatic element 171 as will be described hereinafter.

Thecasing 170 is formed with achamber 194 on the lower end of theland 178 which is sealed from atmospheric pressure by means of acover plate 195. Aport 196 opens into thechamber 194 and is connected through aconduit 197 to theair intake manifold 73. The pressure within thechamber 194 which acts upon the lower end of theland 178, therefore is substantially manifold vacuum.

Referring to Fig. 5, there is illustrated amechanical linkage 200 that may be utilized with thethrottle body 12. Thelinkage 200 comprises afirst throttle lever 201, asecond throttle lever 202, athird throttle lever 203, a fast idle stop arm 204, a fastidle choke lever 205, and achoke cam lever 206. Thefirst throttle lever 201 is fixedly attached to thethrottle valve shaft 166 and is operated by athrottle rod 207 which is connected to a conventional accelerator pedal (not shown). Thesecond throttle lever 202 has abushing portion 208 formed integrally therewith which is journalled on thethrottle valve shaft 166. Aspring 209 surrounds and is wound on thebushing portion 208. Thefirst throttle lever 201 is formed with atab 210 which is adapted to make a lost motion connection with one end of thespring 209. Thesecond throttle lever 202 is connected to thethird throttle lever 203 by means of atie rod 211. Thethird throttle lever 203 is fixedly attached to thethrottle valve shaft 167. Thethrottle lever 201 is adapted to be rotated clockwise by means of thethrottle rod 207 for opening thethrottle valve 163 and this clockwise motion is transmitted through thespring 209, thesecond throttle lever 202 andtie rod 211 to thethird throttle lever 203 for opening thethrottle valve 164.

The fast idle stop arm 204 is pivotally mounted on a fixedpin 212, and is interconnected with thechoke cam lever 206 by means of a connectingrod 213. Thefirst throttle lever 201 is formed with a tab 214 which carries an adjusting screw 215 which is adapted to make contact with a stepped cam surface 216 formed on the arm 204. Thefirst throttle lever 201 is also formed with atab Q 217 which carries athrottle stop screw 218.

Thechoke cam lever 206 is journalled on the choke valve shaft and is formed with atab 219 andcam surface 220. Thetab 219 makes a lost motion connection with the fastidle choke lever 205 which is fixedly attached to thechoke valve shaft 165.

Thethird throttle lever 203 is formed with atab 221 which is adapted to make contact with the fast idle stop arm 204 through anotch 222 formed thereon. Thetab 221 in making contact with the fast idle stop arm 204 functions to lock thethrottle valve 164 in a closed position when thechoke valve 162 is closed.

A schematic diagram of an optional circuit for supplying additional starting fuel at low engine temperature is also included on Fig. 5. This circuit comprises a normallyopen switch 230, a normally closedswitch 231, the solenoid operated starting valve 14, and a startingcircuit 232. Theswitch 230 has anarm 233 carrying aroller 234 which is in contact with thecam surface 220 of thecam lever 206. Theswitch 231 has anarm 235 which carries aroller 236 adapted to make contact with a knuckle 237 formed on thethrottle rod 207.

In operation, the starting circuit functions as follows: The solenoid valve 14 is connected in series with the normally openedswitch 230 and the normally closedswitch 231 to the starting circuit of the engine. Theswitch 230 is closed by thechoke cam lever 206 acting against theroller 234 when thechoke valve 162 is substantially closed. The circuit through theswitches 231 and 230 is then complete and during starting of the engine, the valve 14 is energized for supplying additional starting fuel to thethrottle body 12 as previously described. Theswitch 231 is adapted to be opened by the knuckle 237 of thethrottle rod 207 acting against theroller 236 in an open throttle condition, thereby cutting off the starting fuel supplied from the valve 14 for starting the engine under flooded conditions.

In the optional starting circuit shown in Fig. 5, the regulator valve 15 is eliminated, and the auxiliaryfuel supply conduit 26 is connected directly to the conduit 7 In operation: Thediaphragm 83 andcam 80, in Fig. 2, are in position for providing the maximum fuel output from thefuel injection pump 10. Theroller 97 is in contact with the camsurface '92 of thecam 80 at a point c orresponding to the maximum output position. Thespring 84 acting against thediaphragm 83 holds thecam 80 in this position until the force of thespring 84 is overcome by a differential in pressure developed across the diaphragm 83.v

When the engine is started, the manifold vacuum connected through theconduit 62 and.port 61 reduces the pressure within thecasing portion 60a and atmospheric pressure tends to force thediaphragm 83 to the left against the action of thespring 84. Thediaphragm 83 in turn moves theco'nnecting rod 85 andcam 80 to the left, and theroller 97 takes a position on thecam surface 92 corresponding to a lower output position for thefuel injection pump 10. The distance of travel of thecam 80 and the slope of thecam surface 92 are such that force exerted by thepump 10 does not produce movement of thecam 80. The manifold vacuum is a function of throttle valve opening, and as the pressure within thecasing 60a varies with variations in throttle position, thecam 80 moves, to the right or to the left indirect relationship to load demand of the engine. The

starting and operating conditions just described would correspond to normal warm engine operating conditions.

For cold engine starting, and for engine warm-up conditions, the warm-upenrichment valve 13 functions to modify the manifold vacuum supplied to the interior of the casing 6001. It is desirable that additional fuel or a richer ratio of fuel to air be supplied for starting the cold engine. When the engine is cold, thethermostatic element 171 functions to pull thepiston 172 upward, as shown, permitting air from theorifice 168 to bleed through thechannel 186, theport 185, theport 66, theconduit 65, and into thecasing 60a for modifying or decreasing the manifold vacuum acting on thediaphragm 83. Therestriction 70 in theconduit 62 prevents the manifold vacuum in theline 62 from nullifying the air bleed effect from theconduit 65. The lowered differential in pressure across thediaphragm 83 produced by the air bled into thecasing 60a causes thecam 80 to take a higher than normal output position. Therestriction 70 also prevents the manifold vacuum in theconduit 62 from nullifying the effect ofidle adelement 171 and tends to warm it so as to reduce the tension or force that lifts thevalve piston 172 away from the seat 184. As thethermostatic element 171 is warmed, manifold vacuum supplied throughconduit 197 andport 196 acts on the lower end ofland 178 of thepiston 172, tending to pull it downward so that the flaredportion 180 tends to seal against the seat 184, thereby tending to cut off the air bled from theport 185. While thethermostatic element 171 is being warmed and thepiston 172 moves downward, the taperedportion 179 gradually decreases the amount of air bled past the seat 184. The configuration of the taperedportion 179 is predetermined so as to decrease the air bled corresponding to engine warm-up, and consequently corresponding to engine fuel requirements during warm-up. In addition, as thepiston 172 moves downward during warm- 'up, the force supplied by manifold vacuum on theland 177 acts through the link 175 and bell crank 174 so as to turn thechoke shaft 165 and thereby open thechoke valve 162.

Thevalve piston 172 operates as a function of engine load condition to provide greater enrichment during high load conditions than at low load conditions. This operation is produced as follows: At low load, the manifold vacuum acting on the lower end of theland 178 is comparatively high. The pressure on the upper side of theland 178 is substantially greater because of the air bled through theorifice 185; therefore, the differential in pressure acting on theland 17 8 tends to move thepiston 172 downward and thereby acts through the link 175, crank 174, and choke shaft 165'so as to open thechoke valve 162. During high load conditions, the manifold vacuum acting on the lower end of theland 178 is comparatively low; consequently, the differential in .pressure across theland 178 is very low, and the force tending to open thechoke valve 162, therefore, is comparatively low. The warm-upenrichment valve 13, therefore, not only modifies the output of the fuel injection pump but also modifies the amount of air being supplied to the engine, thereby further controlling the fuel-air ratio in accordance with engine demand during warm-up.

It should be noted that theswitch 230 of the optional starting circuit shown on Fig. 5 is operated by thelever 206 attached to thechoke valve shaft 165, which in turn is attached to thethermostatic element 171. Thethermostatic element 171, therefore, is also utilized for providing additional starting fuel in addition to the enrichment previously described during warm-up.

It is contemplated that thevalve piston 172 may be separated into two separate pistons for performing the same desirable functions as described above. For this purpose, theland 178 should be connected to thechoke valve 162 through a suitable linkage so as to tend to open the choke valve with increased differential in pressure across theland 178. Theland 177 should carry thetapered portion 179 and be connected to thethermostatic element 171 for performing the air bleed function as previously described.

The output of thefuel injection pump 10 is modified in accordance with atmospheric pressure conditions by the compensatingmechanism 82. The connectingrod 110 is adapted to be moved to the right or to the left, as shown on Fig. 2, so that thewedge surface 112 acts against the knuckle 109 andarm 106 for moving the cam into a higher output or lower output position with variations in atmospheric pressure, The distance of travel of therod 110 and the slope of thesurface 112 is such that force exerted by the arm 1116 does not produce movement in themechanism 82. The expansible bellows 121 is directly responsive to absolute atmospheric pressure and expands or contracts in direct relation therewith. The amount of power developed by thebellows 121 is relatively small; consequently, the power amplifying means comprising thediaphragms 122 and 123, and the slidingvalve mechanism 124 are provided. Manifold vacuum is supplied through theport 71 to the interlor ofthechambers 140a and 141a. Thediaphragms 122 and 123, being of the same size, are in a balanced position when no air-is bled into either of thechambers 140a and 141a.

Assuming the atmospheric pressure to decrease,thebellows 121 expands and, in expanding, this motion is transmitted through the lever arm and sliding valve block 133 so as to the move theport 152 into communition with theport 155. This communication permits air to be bled through theports 152 and 155, andchannel 158 into thechamber 141a. The differential in pressure across thediaphragm 123 therefore would be substantially decreased; whereas, the differential in pressure across thediaphragm 122 would remain the same. 'The differential in pressure across thediaphragm 122, therefore would tend to move the connectingrod 110 to the right, which motion would be transmitted through the knuckle 109 andarm 106 for lowering the output position ofthecam 80. The fuel output of the injection air ratio for operating at a lower atmospheric pressure.

The motion of the connectingrod 110 is also transmitted through thelever arm 127 to theshaft 125 of thebellows 121 for moving it to the left as shown. This motion in turn is transmitted through thelever arm 130 so as to move the valve block 133 to the right and center theport 152 in a non-communicating position between theports 155 and 156. Thebellows 121 and sliding valve block 133, therefore, are repositioned so as to be operative fora subsequent change in atmospheric pressure.

For an increase in atmospheric pressure, thebellows 121 contracts and the valve block 133 moves to the right as shown so as to bleed air through theport 152 andport 156 into the chamber 14th: for increasing the pressure therein. Thebellows 121 and valve block 133 are repositioned by means of thelever 127 as previously described, for a subsequent change in atmospheric pressure. The compensatingmechanism 82 thereby provides means for automatically compensating for changes in atmospheric pressure for meeting engine fuel demands. It is contemplated that the slidingvalve mechanism 12 may be replaced by a corresponding rotatable device which would perform the same desirable function.

We wish it to be understood that this invention is not to be limited to the specific constructions and arrangements shown and described except only insofar as the appended claims may be so limited, as it will be apparent to those skilled in the art that changes may be made without departing from the principles of the invention.

We claim:

1. In a control system for a fuel injection pump adapted to supply fuel to an internal combustion engine having an air intake manifold, the combination of choke valve means adapted to restrict the flow of air into said manifold, vacuum responsive means for controlling the output of said pump, conduit means interconnecting the manifold with said vacuum responsive means for supplying manifold vacuum thereto, means defining a restriction in said conduit for limiting the flow of air therethrough, temperature responsive valve means for bleeding air into said vacuum responsive means, and means interconnecting said temperature responsive valve means with said choke valve means and operable thereon for restricting the flow of air into the manifold for thereby providing an optimum fuel-air ratio to the engine during warm-up.

2. In a control mechanism for a fuel injection pump adapted to supply fuel to an internal combustion engine having an air intake manifold, the combination of a vacuum responsive motor for controlling the output of the pump; conduit means for interconnecting said manifold with said vacuum responsive motor for supplying manifold vacuum thereto; and air bleed means for supplying a limited amount of air to said motor for modifying the effect of the manifold vacuum acting thereon, said last named means including a valve piston having a tapered portion adapted to restrict the flow of air through said bleed means, and temperature responsive means attached to one end of said valve piston for moving it longitudinally and thereby progressively decreasing the amount of air bled through said valve with increasing temperature.

3. in a control mechanism for a fuel injection pump adapted to supply fuel to an internal combustion engine having an air intake manifold, the combination of a vacuum responsive motor for controlling the output of the pump; conduit means for interconnecting said manifold with said vacuum responsive motor for supplying manifold vacuum thereto; and air bleed means for supplying a limited amount of air to said motor for modifying the effect of the manifold vacuum acting thereon, said last named means including a valve piston having a tapered portion adapted to restrict the flow of air through said air bleed means and vacuum responsive means including a land formed on one end of said valve piston and means for supplying manifold vacuum to one end of said land for thereby moving said valve piston longitudinally so as to decrease the amount of air flowing through said air bleed means with increased manifold vacuum,

4. In a control mechanism for a fuel. injection pump adapted to supply fuel to an internal combustion engine having an air intake manifold, the combination of a vacuum responsive motor for controlling the output of the pump; conduit means for interconnecting said manifold with said vacuum responsive motor for supplying manifold vacuum thereto; and air bleed means for supplying a limited amount of air to said motor for modifying the effect of the manifold vacuum acting thereon, said last named means including a valve piston having a tapered portion adapted to restrict the flow of air through said bleed means, temperature responsive means attached to said valve piston and adapted to move it longitudinally so as to decrease gradually the amount of air flowing through said valve with increasing temperature and vacuum responsive means including a land formed on one end of said valve piston and means for supplying manifold vacuum thereto for moving said valve piston in opposition to said temperature responsive means for thereby reducing the amount of air bled through said valve means with increased manifold vacuum.

5. In a control system for a fuel injection pump adapted to supply fuel to an internal combustion engine having an air intake manifold, the combination of a choke valve adapted to restrict the amount of air flowing into the manifold; a manifold vacuum responsive motor adapted to control the fuel output of the pump; and an air bleed valve mechanism adapted to supply a limited amount of air to said vacuum responsive motor for modifying the output of said pump, said valve mechanism comprising a longitudinally movable valve piston having a land and a tapered portion for restricting the air bled through said valve, means for interconnecting said valve piston with said choke valve, temperature responsive means connected to said piston and adapted to increase the amount of air flow through said valve mechanism, and means for supplying manifold vacuum to said valve piston so as to act on said land for moving said piston in opposition to said temperature responsive means for restricting the amount of air bled through said valve and increasing the air flow through said choke valve.

6. In a control mechanism for fuel injection pump adapted to supply fuel to an internal combustion engine having an air intake manifold in which the pressure varies with load conditions, the combination of a choke valve adapted to restrict the flow of air into the manifold; manifold vacuum responsive means for controlling the fuel output of the pump; and air bleed valve means for supplying a limited amount of air to said vacuum responsive means for modifying the output of said pump, said last named means including a valve piston having a tapered portion and a land portion, means interconnecting said valve piston with said choke valve, and means for supplying manifold vacuum to said valve for acting on said land and thereby move said valve piston into an air flow restrictive position for thereby controlling the amount of air bled to said vacuum responsive means and also controlling the amount of air flowing past said choke valve, for thereby providing an optimum fuel air ratio in accordance with load conditions of the engine.

7. In a control mechanism for a fuel injection pump adapted to supply fuel to an internal combustion engine having an air intake manifold, the combination of manifold vacuum responsive means for controlling the output of said pump; air bleed valve means for modifying the effect of said vacuum responsive means; thermostatic means adapted to control the amount of air bleed through said valve means; and auxiliary fuel supply means for supplying additional fuel for starting the engine, said last named means includingan electrical starting circuit, a solenoid-operated valve interconnected with said circuit, and switch means also interconnected with said circuit and operated by said thermostatic means for rendering said solenoid valve means inoperative above a predetermined temperature.

8. In a control mechanism for a fuel injection pump adapted to supply fuel to an internal combustion engine having an air intake manifold, the combination of a choke valve means adapted to restrict the flow of air into the manifold; a manifold vacuum responsive motor for controlling the output of said pump; air bleed valve means for bleeding a limited amount of air into said vacuum responsive motor for modifying the output of said pump; and thermostatic means operable to control the amount of air bled through said valve and also operable to progressively open said choke valve with increasing temperature for thereby providing an optimum fuel-air ratio to the engine.

9. In a control mechanism for a fuel injection pump adapted to supply fuel to an engine having an air intake manifold, the combination of a choke valve adapted to restrict the flow of air into the manifold; thermostatic means connected to said choke valve for progressively opening said valve with increasing temperature; and auxiliary fuel supply means adapted to supply additional starting fuel into said manifold, said last named means including electrically operated valve means and switch means adapted to render said electrically operated valve means inoperative above a predetermined opening of said choke valve.

10. In a control mechanism for a fuel injection pump adapted to supply fuel to an engine having an air intake manifold and having an electrical starting circuit, the combination of manifold vacuum responsive means for controlling the output of the pump; air bleed means for modifying the effect of said vacuum responsive means; and auxiliary fuel supply means for supplying fuel in addition to the output of the pump, said last named means including solenoid-operated valve means interconnected with the engine starting circuit and temperature responsive means for regulating the amount of additional starting fuel in accordance with engine temperature.

11. In a control mechanism for a fuel injection pump adapted to supply fuel to an engine having an air intake manifold, the combination of a manifold vacuum responsive diaphragm, a cam movable in two directions and connected to said diaphragm, means for interconnecting said cam with the purrrp for controlling the output thereof in accordance with the position of said cam, a first lever mechanism for positioning said earn, a second lever mechanism for also positioning said cam, and pressure responsive means interconnected with said second lever mechanism for modifying the position of said cam in accordance with pressure changes.

12. In a control mechanism for a fuel injection pump, the combination of a vacuum responsive motor; a cam movable in two directions and connected to said vacuum responsive motor, said cam being formed with a cam surface and two pivot points; a cam follower in contact with said cam surface and connected to the pump for controlling the output thereof; a first guide arm in contact with one of said pivot points for positioning said cam; adjustable means for determining the position of said guide arm; a second guide arm in contact with said second pivot point for further positioning said cam; and atmospheric pressure responsive means connected to said second guide arm for adjusting the position thereof in accordance with variations in atmospheric pressure.

13. In a control mechanism for a fuel injection pump, the combination of a movable cam for controlling the output of the pump; a vacuum responsive diaphragm for moving said cam; and atmospheric pressure responsive means for further moving-said'cam, said last named means including an expansible bellows responsive to atmospheric pressure, vacuum responsive means interconnected with said cam, valve means for bleeding air into said vacuum responsive means, means for interconnecting said valve means with said bellows, and repositioning means for interconnecting said vacuum responsive means with said bellows.

14-. In a control mechanism for a fuel injection pump for an internal combustion engine having an air intake manifold, the combination of a movable cam for contro the output of the pump; a manifold vacuum responsive motor for moving said cam; and atmospheric pressure responsive means for further moving said cam, said last named means including an atmospheric pressure responsive device, power amplifying means interconnecting said atmospheric pressure responsive device with said cam, and repositioning means interconnecting said power amplifying means with said atmospheric pressure responsive device so as to position it for a subsequent change in atmospheric pressure.

15. In a control mechanism for compensating for changes in atmospheric pressure, the combination of an output shaft, power amplifying means .for moving said shaft, movable control means for controlling said power amplifying means, atmospheric pressure responsive means for operating said control means, and repositioning means interconnecting said output shaft with said pressure responsive means.

16. In a control mechanism for compensating for changes in atmospheric pressure, the combination of an output shaft, power amplifying means including two vacuum responsive diaphragms connected to and adapted to move said shaft, movable valve means for bleeding air to one or the other of said vacuum responsive diaphragms, an expansible bellows for moving said valve, and repositioning means connecting said bellows with said output shaft for repositioning said bellows and rendering it operative for a subsequent change in atmospheric pressure.

17. In a control mechanism for a fuel injection pump adapted to supply fuel to an engine having an air-intake manifold and having an electrical starting'circuit, the combination of a throttle valve for restricting the flow of air into the manifold; manifold vacuum responsive means for controlling the ouput of the pump; and auxiliary fuel supply means for supplying fuel in addition to the output of the pump, said last-named means including an electrically operated valve interconnected with the engine starting circuit for supplying additional starting fuel, and electrical switch means interconnected with said throttle for rendering said valve inoperative when said throttle valve is substantially wide open.

18. In a control mechanism for a fuel injection pump adapted to supply fuel to an engine having an air-intake manifold and having an electrical starting circuit, the combination of a throttle valve adapted to restrict the flow of air into the manifold; means responsive to manifold vacuum for controlling the output of the pump; and auxiliary fuel supply means for supplying fuel in addition to the output of the pump, said last-named means including an electrically operated valve interconnected with the engine starting circuit for delivering starting fuel into the manifold while the engine is being started, first switch means for rendering said valve inoperative above some predetermined temperature, temperature responsive means for actuating said switch, and second switch means interconnected with said throttle and operable to render said valve inoperative for substantially wide open throttle condition.

References Cited in the file of this patent UNITED STATES PATENTS 2,821,184 Groezinger Jan. 28, 1958 2,851,026 Dahl et al. Sept. 9, 1958 2,893,367 Druzynski July 7, 1959

Images