US3352545A - Carburetor construction - Google Patents

Description

N 1967 I J. F. DENINE 3,352,545

I CARBURETOR CONSTRUCTION Filed May 31, 1966 /2 i 2 Z Z7 7 g C/akn 0mm A 7'7'02/VEK United States Patent. Office 3,352,545 Patented Nov. 14, 1967 3,352,545 CARBURETGR CONSTRUCTION John F. Denine, 180 Lincoln St., Hudson, Mass. 01749 Filed May 31, 1966, Ser. No. 554,045 12 Claims. (Cl. 261-41) ABSTRACT OF THE DISCLOSURE A carburetor apparatus for improving the efilciency and performance of internal combustion engines. The carburetor comprises a fuel regulating idle screw formed of a relatively porous material which both disperses and aerates fuel delivered to the engine.

This invention relates generally to carburetors for use with internal combustion engines and more particularly to a novel fuel supply system for such carburetors.

A large variety of carburetor developments have resulted from attempts to improve the efiiciency and performance of internal combustion engines. These developments have included, for example, multi-stage fuel systerns, automatic chokes, fuel flow metering devices, economizing and enriching devices, etc. The "common object for many of the prior improvements was to obtain a more thoroughly mixed fuel and air charge which would result in a more complete combustion of the fuel upon ignition. Such a result would reduce or eliminate many of the inherent problems associated with internal combustion engines such as carbon deposition, relatively low efiiciency, poor cold weather operation, rough engine operation at low speeds and during acceleration, etc. However, the prior carburetor improvements have failed to fully satisfy the desired objective or to fully eliminate the problems.

The object of this invention, therefore, is to provide for use with internal combustion engines an improved carburetor which improves both the efiiciency and performance characteristics of internal combustion engines.

One feature of this invention is the provision for internal combustion engines of an improved carburetor having a primary-fuel supply system which discharges fuel from a fuel reservoir into a mixing conduit anterior to a throttle valve and an idle fuel system which discharges fuel from the fuel reservoir through an idle port into the mixing conduit posterior of the throttle valve and wherein the idle fuel system includes an adjustment element composed of a relatively porous material and adapted to regulate the rate of fuel flow through the idle port. The relatively porous adjustment element disperses and aerates the fuel which in turn improves engine efiiciency and performance.

Another feature of this invention is the provision for internal combustion engines of an improved carburetor having a primary fuel system adapted to discharge fuel from a fuel reservoir into a mixing conduit anterior to a throttling valve and including a fixed fuel nozzle composed of a relatively porous material and projecting into the mixing conduit adjacent a venturi. As above, the porous nozzle effects a greatly improved dispersion and aeration of the injected fuel to thereby improve engine efliciency and performance.

Another feature of this invention is the provision for internal combustion engines of a carburetor of the above featured type wherein an adjustable idle screw forms at least a part of the adjustment element.

Another feature of this invention is the provision of an internal combustion carburetor of the above featured types wherein the relatively porous material used for the fuel nozzle and idle adjustment is sintered metal.

Another feature of this invention is the provision for internal combustion engines of a carburetor of the above featured types wherein the relatively porous material utilized for the fuel nozzle and adjustment element possesses an open porosity of between 30 and percent.

Another feature of this invention is the provision for internal combustion engines of a carburetor of the above featured types wherein the relatively porous material used for the fuel nozzle and the adjustment element has an average pore size of between 2 and 50 microns.

These and other objects and features of the present invention will become more apparent upon a perusal of the following specification taken in conjunction with the accompanying drawing which is a schematic cross-section showing a preferred embodiment of the invention.

Referring now to the drawing there is shown the mixing conduit 11 including the air born 12, theventuri section 13 and the throttle bore 14. Positioned within the mixing conduit 11 is thethrottle valve 15 Which is mounted for rotation with thethrottle shaft 16. The fuel bowl 17 functions as a fuel reservoir for the device.

The primary fuel supply system 21 including thefuel well 22, the high speed fuel passage 23 and thefuel nozzle 24 provides a fuel discharge path between the fuel bowl 17 and the mixing conduit 11. Thefuel nozzle 24 projects into the mixing conduit 11 adjacent theventuri portion 13. Regulating the flow rate of fuel from the fuel bowl 17 is themetering orifice member 25 andfuel metering rod 26. Themetering rod 26 is actuated by a conventional mechanism (not shown) so as to provide a controlled fuel flow rate.

The idlefuel supply system 31 includes theidle fuel passage 32 which provides a fuel flow path between theidle ports 33 and 34 and theidle tube 35 which opens into the high speed fuel passage 23. Theupper idle port 33 opens into the mixing conduit 11 anterior to thethrottle valve 15 when in a closed position and thelower idle port 34 opens into the mixing conduit posterior to the throttle valve 17 when in the closed position. Supported by threads in the wall of the mixing conduit 11 is theidle screw 36 withvalve stem 37 which extends an ad justable distance into thelower idle port 34 so as to regulate fuel flow therethrough.

According to the invention thefuel nozzle 24 and theidle screw 36 are composed of a relatively porous material. During movement along the surfaces of the porous material and through the pores therein, fuel is broken up into an extremely fine dispersion and thoroughly aerated before injection into the mixing conduit 11. Also, because of the increased area of exposed fuel surface a substantial increase in the rate of fuel evaporation occurs. The fuel evaporation which occurs on the surfaces of the porous material and within the mixing conduit 11 provides a beneficial cooling of the entire carburetor body. As a result of the improved fuel dispersion and carburetor cooling a much more complete fuel combustion is obtained. Accordingly, there is obtained a reduction in fuel consumption, smoother engine performance, increased power, reduction of carbon depositions, improved cold weather engine performance, etc.

While sintered metals such as steel, nickel, and particularly bronze are preferable for use as the relatively porous material in thefuel nozzle 24 andidle screw 36, other porous materials are suitable. These can include, for example, composite materials formed by porous granules of alumina, silicon carbide, mulite, etc., bonded together with a suitable ceramic. It is important, however, that the material possess a relatively high open porosity so as to be permeable to both air and fuel. For example, it has been found extremely desirable for reasons of permeability and strength that the material possess an open .3 porosity of between 30 and 60 percent as established by the following formula:

where P represents the percentage of open porosity, W represents the weight of a material sample in air, W represents the weight of the same material sample after immersion in a given liquid, D represents the apparent density of the sample material and D represents the density of the given liquid. It has also been found desirable that the material have pores with an average size of between 2 and 50 microns.

Obviously, many modifications and variations of the present invention are possible in light of the above teachings. For example, thefuel nozzle 24 or theidle screw 36 can be composite units composed of both porous and solid materials. In that case, the portion of the element which is most effective in dispersing the fuel would preferably be composed of a porous substance. Thus, thevalve stem 37 could be porous and the threaded base of theidle screw 36 could be solid. Similarly, the end of thenozzle 24 which projects into the mixing conduit 11 could be porous and the nozzle base supported within the fuel passage 23 could be solid. It is, therefore, to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. A carburetor for use in an internal combustion engine and comprising a mixing conduit, a fuel reservoir, a rotatable throtle shaft extending into said mixing conduit, a throttle valve mounted on for rotation with said throttle shaft, venturi means in said mixing conduit anterior to said throttle valve, a primary (fuel supply system adapted to discharge fuel from said fuel reservoir to said mixing conduit adjacent said venturi means in response to engine demands, a metering means adapted to regulate the amount of fuel passing from said fuel reservoir to said main supply system, an idle fuel system adapted to discharge fuel from said fuel reservoir through an idle port which opens into said mixing conduit posterior tosaid throttle valve when in a substantially closed position, and said idle fuel system including an adjustment means extending into said idle port so as to regulate the .rate of fuel flow therethrough, and wherein said adjustment means is composed of a relatively porous material.

2. A carburetor according to claim 1 wherein said relatively porous material is sintered metal. 7

3. A carburetor according to claim 1 wherein said relatively porous material has an open porosity of between thirty and sixty percent.

4. A carburetor according to claim 3 wherein said relatively porous material is sintered metal.

5. A carburetor according to claim 1 wherein the pores in said relatively porous material have an average size of between two and fifty microns.

6. A carburetor according to claim 1 including an adjustable idle screw which comprises said adjustment means.

7. A carburetor according to claim 6 wherein said relatively porous material is sintered metal.

8. A carburetor according to claim 7 wherein said relatively porous material has an open porosity of between thirty and sixty percent.

9. A carburetor according to claim 1 wherein said primary fuel supply system includes a fixed fuel nozzle at least partly composed of a relatively porous material and projecting into said mixing conduit adjacent said venturi means.

10. A carburetor according to claim 9 wherein both said relatively porous materials comprise sintered metal,

11. A carburetor according to claim 9 wherein both said relatively porous materials have an open porosity of between thirty and sixty percent.

12. A carburetor according to claim 11 wherein both said relatively porous materials comprise sintered metal.

References Cited UNITED STATES PATENTS Re. 24,232 10/ 1956 Johnson 261-99 X 1,857,565 5/1932 Pahl et al. 261-99 2,530,716 11/ 1950 Meynier 261-99 X 2,551,114 5/1951 Goddard 261-99 X 2,711,885 6/ 1955 Moseley.

2,816,573 12/1957 Kaddis et al. 3,166,611 l/1965 Conant et al. 3,199,847 8/1965 Wahnish 261-99 X FOREIGN PATENTS 819,574 9/1959 Great Britain.

HARRY B. THORNTON, Primary Examiner. TIM R. MILES, Assistant Examiner, V

Claims (1)

1. A CARBURETOR FOR USE IN AN INTERNAL COMBUSTION ENGINE AND COMPRISING A MIXING CONDUIT, A FUEL RESERVOIR, A ROTATABLE THROTLE SHAFT EXTENDING INTO SAID MIXING CONDUIT, A THROTTLE VALVE MOUNTED ON FOR ROTATION WITH SAID THROTTLE SHAFT, VENTURI MEANS IN SAID MIXING CONDUIT ANTERIOR TO SAID THROTTLE VALVE, A PRIMARY FUEL SUPPLY SYSTEM ADAPTED TO DISCHARGE FUEL FROM SAID FUEL RESERVOIR TO SAID MIXING CONDUIT ADJACENT SAID VENTURI MEANS IN RESPONSE TO ENGINE DEMANDS, A METERING MEANS ADAPTED TO REGULATE THE AMOUNT OF FUEL PASSING FROM SAID FUEL RESERVOIR TO SAID MAIN SUPPLY SYSTEM, AN IDLE FUEL SYSTEM ADAPTED TO DISCHARGE FUEL FROM SAID FUEL RESERVOIR THROUGH AN IDLE PORT WHICH OPENS INTO SAID MIXING CONDUIT POSTERIOR TO SAID THROTTLE VALVE WHEN IN A SUBSTANTIALLY CLOSED POSITION, AND SAID IDLE FUEL SYSTEM INCLUDING AN ADJUSTMENT MEANS EXTENDING INTO SAID IDLE PORT SO AS TO REGULATE THE RATE OF FUEL FLOW THERETHROUGH, AND WHEREIN SAID ADJUSTMENT MEANS IS COMPOSED OF A RELATIVELY POROUS MATERIAL.

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