US3322406A - Carburetor - Google Patents

Description

May 30, 1967 F. J- MARSEE ETAL PAYMO/V A. JOETERS INVENTORS May 30, 1967 F. J. MARSEE ETAL 3,322,406

CARBURETOR Filed Nov. 24, 1964 2 Sheets-Sheet 2 FR'ER/C/f J.' MARSEE RA W40/V0 ,4. 50572-795 1N V EN TORS United States Patent Oiiee 3,322,406 CARBURETUR Frederick J. Marsee, Hazel Park, and Raymond A. Soeters,

Royal Oak, Mich., assignors to Holley Carburetor Company, Warren, Mich., a corporation of Michigan Filed Nov. 24, 1964, Ser. No. 413,423 8 Claims. (Cl. 261-34) This invention relates generally to internal combustion engine carburetors, and more particularly to an improved combined accelerating pump and power valve mechanism therefor.

In the past, accelerating pumps, whether mechanically operated or vacuum operated, have been combined with power enrichment systems or have been utilized in conjunction with separate vacuum operated power enrichment systems. While such combinations have been cornmercially acceptable, certain disadvantages have been experienced. For example, where an acceleration pump is combined with a power valve mechanism wherein the pump piston mechanically contacts a power valve at the end of the pump stroke, a time lag exists between the initial actuation of the accelerating pump and its contact with the power valve. Where independent accelerating pumps and power valve mechanisms are employed, the disadvantage lies in the added expense involved and in the additional space required.

Accordingly, a general object of the invention is to provide a combined accelerating pump and power enrichment system wherein the usual lag in initial operation of the two is eliminated.

A further object of the invention is to provide such a combined accelerating pump and power valve mechanism wherein the initial actuation of the pump, whether by vacuum or mechanical means, causes an immediate hydraulic signal to be transmitted to the power valve mechanism for simultaneous operation thereof.

A more specific object of the invention is to provide such a combined system wherein a pressure responsive device, suitably mounted between the pump chamber and the power valve chamber, serves to actuate the power valve upon receipt of a hydraulic signal created by initial actuation of the accelerating pump and to maintain opertion of the power valve until such time as the pump piston makes a mechanical contact with the power valve through the pressure responsive device.

Other objects and advantages of the invention will become more apparent when reference is made to the following specication and the accompanying drawings wherein: Y

FIGURE l is a cross-sectional view of a carburetor embodying the invention, the carburetor being mounted on an engine.

FIGURE 2 is a plan view of the carburetor shown in FIGURE 1.

FIGURE 3 is a cross-sectional view of the carburetor taken on the plane of line 3 3 of FIGURE l, as if FIG- URE l were a side elevational View, and looking in the direction of the arrows.

FIGURE 4 is a cross-sectional view taken on the plane of line 4--4 of FIGURE l, as if FIGURE 1 were a side elevational View, and looking in the direction of the arrows.

FIGURE 5 is a fragmentary portion of FIGURE l, but illustrating a modification of the invention.

Referring to the drawings in greater detail, FIGURE 1 illustrates a carburetor 10 mounted on an engine intake manifold 12 by :any suitable means, such as the mounting bracket 14 and -bolts 16. The carburetor illustrated is an updraft type carburetor; however, for purposes of the invention, it could just as well be a standard downdraft Patented May 30, 1967 type carburetor. The carburetor 10 comprises a body 18 and a fuel reservoir 20 separated by a gasket 22 therebetween and secured to each other in some suitable manner, such as by screws 24. The body 18 includes an inlet 26 to an induction passage 28 having a choke plate 30, a venturi 32, a fuel nozzle 34 and a throttle plate 36 there- 1n.

The body 18 further includes a fuel inlet 38 and a passage 40 communicating between the inlet 38 and the reservoir 20, with the usual fuel inlet valve 42 mounted in the passage 40 and actuated by means of the usual float mechanism 44 pivotally mounted within the reservoi-r in a suitable manner, as by a pin 46 and bracket 48. The bracket may be cast on an inner surface of the reservoir 20.

The body 18 may be cast so as to include the fuel metering system 50 as an integr-al extended part thereof, suitable for submersion in the fuel reservoir 20. A smaller body 52 may be mounted against the bottom face of the fuel metering system 50 and `be secured thereto by screws 54. A gasket S6 having an integrally formed diaphragm 58 is confined between the bodies 18 and S2. The smaller body portion 52 (FIGURE 4) comprises mounting holes 60, a constantly open fuel inlet port 62, an idle fuel cavity 64, a main fuel cavity 66, a second fuel inlet passage 68 (FIGURE 1) and a power valve chamber 70. The second fuel inlet passage 68 is formed to include a valve seat 72` (FIGURE 3), and a check valve such as ball valve 74 is retained in the passage by a suitable retaining ring 76.

An opening 78 (FIGURE l) formed in a wall of the power valve chamber 70 is normally closed off by a frustoconical Valve 80 having a stem 82 which extends through the chamber 70 and is secured to a cap 84, the latter being located adjacent the diaphragm 58. A spring 86 mounted between a wall of the smaller body 52 and the cap 84 urges the valve 80 closed and the cap 84 toward the diaphragm 58. The smaller body 52 further includes passages 88, 90 and 92 communicating, respectively, between the idle cavity 64 and the main fuel cavity 66, between the constantly open fuel inlet port 62 and the main fuel cavity 66, and between the chamber 70 and the main fuel cavity 66.

The fuel metering system 50 comprises a main fuel passage 94 (FIGURE 3) communicating between the cavity 66 (FIGURE 4) and a passage 96 (FIGURE 3) leading to the fuel nozzle 34. An idle passage 98 (FIGURE 3) communicates between the cavity 64 (FIGURE 4) and a passage 100` which leads to an opening 102 in the induction passage 28. A main -well tube 104 (FIGURE 3) may `be suspended in the main well 94 in the usual manner.

Referring again to FIGURE 1, the fuel metering system 50 further includes concentrically aligned chambers 106 and 108 with pistons 110 and 112 slidably mounted therein. A rigid member 114 may connect the pistons 110 and 112, anda spring 115 is confined between the piston 112 and a retainer 116 formed in the chamber 108.

A passage 117 communicates between the fuel inlet passage 68 and the chamber 108, while a plurality of connected passages 118, 119 .and 120 communicate between the lower end of the chamber 108 and the induction passage A28 downstream of the venturi 32. The passage 118 includes a valve seat 122, a valve 124, and a spring 126 urging the valve 124 against the valve seat 122. The passageway includes a pump shooter restriction 128 xedly secured therein. A passage 130 (FIGURE 2) communicates between the inlet 26 and a midpoint in the chamber 106, while another passage 132 (FIGURE 1) communicates between the intake manifold 12 and the upper end of the chamber 106.

Operation As is well known in the art, air drawn into the induction passage 28 Iby the operation of the engine 12 creates a vacuum in the venturi 32 area. The difference in pressure between the normal air pressure above the fuel in the fuel reservoir 20 and the vacuum at the venturi 32 forces a metered flow of fuel from the fuel reservoir 20 through the main fuel passages 94 and 96 and out the main nozzle 34. The fuel entering the main well passage 94 is metered by the inlet jet or port 62 as the fuel flows from the fuel reservoir 20 to the main well cavity 66 via the passage 90. Filtered air from the carburetor air inlet 26 passes through suitable conduitry (not shown) into the main well tube 104 and thence through the usual air bleed passages (not shown) extending through the wall of the tube. This air thus blends into the upwardly moving fuel as it flows through the passages 94 and 96 to the main nozzle, and the resulting fuel-air emulsion flows into the induction passage 28.

The operation of the idle fuel system is such that when the throttle plate 36 is closed, the manifold vacuum is sufiicient to draw idle fuel from the main well cavity 66 (FIGURE 4) through the passages 88, 66, 98 and 100, through the opening 102 and into the induction passage 28.

As is well known in the art, the purpose of an accelerating pump system is to supply additional quantities of fuel each time that the throttle plate 36 is suddenly opened. This is accomplished by virtue of the effect of vacuum on the piston 110, the vacuum entering the upper part of the chamber 106 via the passa-ge 132. During periods of high manifold vacuum or during closing movement of the throttle plate 36, the pistons 110 and 112 will rise in the chambers 106 and 108 against the force of the spring 115, thereby raising the ball valve 74 off the valve seat 72 in the passage 68 and admitting fuel from the reservoir 20 into the chamber 108 beneath the piston 112 via the passage 117. The combined forces of the spring 126 in the passage 119 and, at times, pressure difference across the valve 124 will maintain the valve 124 against the seat 122 during this stage of operation.

When the throttle plate 36 is suddenly opened and the vacuum decreases in the chamber 106, the pistons 110 and 112 will be forced downwardly in their respective chambers 106 and 108 by virtue of the expansion of the spring 115 in the chamber 108. This will cause the ball valve 74 to close against the seat 72 in the passage 68 and will force fuel from the chamber 108 beneath the piston 112 out through the passage 118, past the ball valve 124, up through the passages 119 and 120 and through the pump shooter restriction 128 into the induction passage 28.

The hydraulic pressure caused by the descending piston 112 in the chamber 108 is sufficient to force the diaphragm 58 downwardly against the cap 84 in the chamber 70, thereby causing the power valve 80 to open, admitting additional fuel into the chamber 70 from whence it is drawn by vacuum through the passage 92 (FIGURE 4) into the main fuel cavity 66 and upwardly through the passages 94 and 96 (FIGURE 3) and out `through the main fuel nozzle 34. Note that this is occurring simultaneously with the flow of fuel through the pump shooter restriction 128 and continues after the piston 112 bottoms against the diaphragm 58.

In prior systems, a lag occurred between the initial actuation of a piston comparable to the pistons 110 and 112 and the opening of a power valve similar to the valve 80, since, in the usual combined accelerating and power enrichment system, it would be necessary for the piston to move completely to the bottom of its chamber before coming physically into contact with the power valve mechanism. It is apparent that this inherent deficiency in prior art systems is corrected by the inclusion of the diaphragm 5S adjacent the power valve mechanism and that the in- CIN vention is particularly suited for those engines which require the substantially instantaneous injection of accelerating pump fuel and additional power enrichment fuel. For purposes of the invention, the diaphragm 58 could just as well -be a piston or any other pressure responsive device.

A mechanically operated accelerating pump system may be used in lieu of the vacuum actuated device of FIGURE 1. Such a modification is illustrated in FIGURE 5, wherein the vacuum passage 132 and the spring 115 have been replaced by a member 134 secured or operatively connected at one end thereof to the top of the piston 110. The member 134 extends through a guide opening 136 in the top of the chamber and may be pivotally connected at its other end to a link 13S which, in turn, is pivotally connected to a lever 140, the latter being secured to an end of the throttle shaft. In this embodiment, the pistons and 112 will be slidably moved in the chambers 106 and 108 in response to opening and closing movement of the throttle plate 36.

It is apparent also that the invention discloses a combined accelerating pump and power enrichment system which is much less expensive and less space-consuming than the usual separate systems and eliminates the inherent disadvantages thereof.

Although but two embodiments of the invention have been disclosed and discussed, it is apparent that other modifications of the invention are possible within the scope of the appended claims.

What we claim as our invention is:

1. An internal combustion engine carburetor, comprising an induction passage having a choke plate, a fuel nozzle, a venturi and a throttle plate therein, an idle fuel system, a main fuel metering system for supplying fuel through said fuel nozzle in response to vacuum, and isolated systems operated by a common means and including individual accelerating fuel and power enrichment fuel chambers separated by a common imperforate movable wall, each chamber having separate fuel inlet and outlet passages, for simultaneously supplying accelerating fuel to said induction passage and adding power enrichment fuel to said main fuel metering system, and valve means to control fiow through said power enrichment fuel chamber and actuated in response to movement of said movable wall.

2. The device as described in claim 1, wherein said common means is pressure responsive.

3. The device as described in claim 1, wherein said common means comprises both manually operated and pressure responsive elements.

4. An internal combustion engine carburetor, comprising an induction passage having a choke plate, a fuel nozzle, a venturi and a throttle therein, an idle fuel system, a main fuel metering system for supplying fuel through said fuel nozzle in response to vacuum, means including a piston movable in a first chamber for supplying accelerating fuel to said induction passage, means for actuating said piston and imperforate diaphragm means actuated by a pressure increase caused by movement of said piston in the discharge direction thereof for simultaneously supplying power enrichment fuel from a separate second chamber to said main fuel metering system, said diaphragm forming a movable wall between said chambers to isolate said accelerating fuel from said power enrichment fuel, and valve means to control flow through said second fuel chamber and actuated in response to movement of said movable wall.

5. A carburetor for an internal combustion engine having an intake manifold, said carburetor comprising an induction passage having a choke plate, a fuel nozzle, a venturi and a throttle plate therein, an idle fuel system, a main fuel metering system for supplying fuel through said fuel nozzle in response to vacuum, a fuel reservoir, and a combined accelerating pump and power enrichment system, said combined system comprising a first charnber, a piston slidably mounted in said chamber, a first passageway communicating between said intake manifold and one end of said first chamber, a second chamber adjacent the other end of said first chamber, a pressure responsive device forming a movable wall between said other end and said second chamber, valve means in said second chamber operatively connected to said pressure responsive device for controlling fuel fiow from said fuel reservoir into said second chamber, a second passageway communicating between said second chamber and said main fuel system, an inlet into said other end of said rst chamber, a valve for at times closing olf said inlet, a third passageway communicating between said other end of said first chamber and said induction passage, and valve means for at times closing off said third passageway.

6. An internal combustion engine carburetor comprising an induction passage having a choke plate, a fuel nozzle, a venturi and a throttle plate therein, an idle fuel system, a main fuel metering system for supplying fuel through said fuel nozzle in response to vacuum, and a combined accelerating pump and power enrichment system, said combined system comprising a first chamber, a piston slidably mounted in said chamber, mechanical means operatively connected between said piston and said throttle plate, a second chamber adjacent the other end of said first chamber, a pressure responsive device forming a movable wall between said other end and said second chamber, valve means in said second chamber operatively connected to said pressure responsive device for controlling fuel liow from said fuel reservoir into said second chamber, a first passageway communicating between said second chamber and said main fuel system, an inlet into said other end of said first chamber, a valve for at times closing olf said inlet, a second passageway communicating between said other end of said first chamber and said induction passage, and valve means for at times closing olf said second passageway.

7. A carburetor for an internal combustion engine having an intake manifold, said carburetor comprising an induction passage having a choke plate, a fuel nozzle, -a venturi and a throttle plate therein, an idle fuel system, a main fuel metering system for supplying fuel through said fuel nozzle in response to vacuum, and ya combined accelerating pump and power enrichment system, said combined system comprising a two-diameter chamber, a two-diameter piston slidably mounted in said chamber, a lfirst passageway communicating between said intake manifold and one end of said two-diameter chamber, a second chamber adjacent the other end of said two-diameter chamber, a pressure responsive device forming a movable Wall between said other end and said second chamber, an opening in said second chamber, a valve adjacent said opening, a spring retainer in said second chamber adjacent said pressure responsive device, a stem connecting said valve to said spring retainer, a spring surrounding said stem and confined between said spring retainer and a wall of said second chamber, a second passageway communicating between said second chamber and said main fuel system, an inlet into said other end of said twodiameter chamber, a valve for at times closing off said inlet, a third passageway communicating between said other end of said two-diameter chamber and said induction passage, and Valve means for at times closing off said third passageway.

8. An internal combustion engine carburetor, comprising an induction passage having a choke plate, a fuel nozzle, a venturi and a throttle therein, an idle fuel system, a main fuel metering system for supplying fuel through said fuel nozzle in response to vacuum, first pressure responsive means for supplying accelerating fuel to said induction passage, means for actuating said first pressure responsive means, and second pressure responsive means actuated by the pressure rise caused by movement of said iirst pressure responsive means for simultaneously supplying power enrichment fuel to said main fuel metering system, said second pressure responsive means comprising a common imperforate movable wall isolating said accelerating fuel from said power fuel and valve means to control the ow of power enrichment fuel and actuated in response to movement of said movable wall.

References Cited UNITED STATES PATENTS 2,025,504 Y 12/1935 Geiger 261-34 2,212,946 8/ 1940 Mock et al. 261-34 2,406,114 8/1946 Sloane et al. 261-34 2,478,613 8/ 1949 Weber 261-34 X 2,563,096 8/1951 Bicknell 261-34 2,601,975 7/1952 Hunt 261-34 2,619,333 11/1952 Carrey 261-34 2,775,435 12/ 1956 Kommer 261-34 HARRY B, THORNTON, Primary Examiner. T. MILES, Assistant Examiner,

Claims (1)

1. AN INTERNAL COMBUSTION ENGINE CARBURETOR, COMPRISING AND INDUCTION PASSAGE HAVING A CHOKE PLATE, A FUEL NOZZLE, A VENTURI AND A THROTTLE PLATE THEREIN, AN IDLE FUEL SYSTEM, A MAIN FUEL METERING SYSTEM FOR SUPPLYING FUEL THROUGH SAID FUEL NOZZLE IN RESPONSE TO VACCUM, AND ISOLATED SYSTEMS OPERATED BY A COMMON MEANS AND INCLUDING INDIVIDUAL ACCELERATING FUEL AND POWER ENRICHMENT FUEL CHAMBERS SEPARATED BY A COMMON IMPERFORATE MOVABLE WALL, EACH CHAMBER HAVING SEPARATE FUEL INLET AND OUTLET

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