US2508312A - Manifold injection carburetor - Google Patents

Description

- May 16, 1950 s, M, UDALE 2,508,312 X' MANIFOLD INJECTION CARBURETOR Filed May 18, 1946 /lZ//Gn INVENTOR.

Patented May 16, 1950 OFFICE MANIFDLD `INJ'ECTION (JiARBURETQR 'Stanley MfUda'le, Detroit, .Mich., ,assignor 5to VGeorge Mflolley andEarl Holley Application May'lS, 1946, Serial 1510.670594 (Cl. 12S-119) 2 Claims.

Y'ill-1e object fof .this invention is to :simplify ythe means shawn .in -my Patent ,-No. 2,3995'077 `issued April 23, 1946, for aircraft and to :appl-y them to canburetors for t.ordinary automotive vehicles, boats, and stationary engines.

The idea is'brieflyto throttle on the fuel and not on theair so that the problem of acceleration is largely eliminated.

Another object is to correct for temperature.

Another :object `is vto provide means whereby the fuelis discharged simultaneously at all ports .and liniformly distributed without the use of a distributor." "During vthe interval between `in- ;duction strokes in the combustion chamber .95 the fuelis caught on a screen and removed .from :the screen .when 'it is the inlet Kvalvefs ytinzn to npen; By 'this means it is possible to obtain the result Vheretofore only vobtainableV by the -use of a distributor. Fig. l shows in partial cross-sectional elevation a view of the fuel/air ratio controlling means. Fig. 2 shows a cross-sectional elevation through an inlet manifold and one cylinder of a multicylinder engine.

I8 is the air entrance, I2 is a venturi therein,

I4 is a small venturi discharging into the throat of the larger venturi, I6 is a pipe connecting the throat of the small venturi I4 with the chamber 22, 24 are impact tubes carried by the venturi |2, is a pipe connecting the chamber 28 to the chamber |8, 28 is a diaphragm separating the chamber 22 from the chamber I8, 38 is a small rod engaging with and connected to the large diaphragm 28 and to the smaller diaphragm 32 which forms the right-hand wall of a chamber 34, which is connected through a pipe 36 with a fuel manifold 38, which discharges fuel into the ports 49-42-44-46 through the orifices 48-58-52-54 To the right of the diaphragm 32 is a chamber 56 connected through a pipe 58 with an in let passage '69 on the engine side of a throttle 82. A throttle lever 64 is rotated anti-clockwise by a compression spring 86 and engages with the cam 68, which is moved anti-clockwise to open by a manually-controlled lever l0. A valve 'l2 controls the ilow of fuel through e, passage 14. 16 and 'I1 are inlet fuel passages which deliver fuel to a chamber 'I8 past a balanced valve 89. The valve 89 is supported at both ends by two diaphragms 82 and 84. A relatively weak spring |94 is provided to open the valve 89 slightly so that at low fuel iiows the full fuel pressure is applied to the manually operated valve 12 when this valve 12 is in the position shown, that is, when 4the lever 88.

closed sposi-tion. The valve `89 is perforated with openings 9|.

In Fig. 2, the :fuel inlet manifold 38 is shown discharging fuel against a perforated screen 88. The air inlet manifold :99, which is shown in cross-section, delivers air both iacross the perforatedscreen 88 and'through the Aperforated screen y88. Vaporized fuel therefore arrives at the openit is almost closed. A rod 88, which is pushed ing around the engine inlet valve 92 and thus enters the combustion chamber 95 in condition to be exploded.

In order to make some correction for temperature, no correction being made for pressure, a passage |02 is provided connecting the chamber 22 and I8 together. A passage 93 with a restricted outlet I I0 acts as Aa, drain for both chambers I8 and 22. The valve .94 is controlled by a lever 96 which is moved by the thermostatic bimetal element 98. A restriction |00 in the passage 29 renders the valve 94 effective at high temperature to vary the pressure in the chamber I8 so that when the air density falls by reason of an increase in temperature the mixture tends to remain approximately constant. The thermostat 98 thus prevents the mixture becoming rich at high temperature. At high temperatures the density of the air falls and without a thermostat the mixture would become rich. If the valve 94 is made to open at high temperature then there is less pressure difference acting on diaphragm 28 at any given air flow, which thus calls for less fuel so that the fuel/air ratio is maintained constant. The passage 93 maintains air flow over the thermostat 98 so that the temperature in the chamber I8 is approximately the temperature in the air entrance I8.

Operation The fuel valve 89 is a balanced valve, hence when it is moved to the right, due to a reduction in airflow, a reduction in fuel flow to balance the reduced air flow causes valve 89 to move to the left in response to an increase in suction in the small venturi |4 so that then the valve 89 admits more fuel to balance the increase fi 2,508,312 e' f in air flow. Generally speaking these are the mechanical and aerodynamic means now in almost universal use for controlling the fuel/air ratio at a predetermined value for airplanes using reciprocating engines. The drop in pressure between the fuel chamber 34 and the inlet manifold 60 causes a now through the restricted orifices 48-50-52-54. This drop in pressure also acts on the diaphragm 32 which diaphragm 32 is moved thereby to oppose the motion referred to of the airflow responsive diaphragm 28.

At idle the cam 68 determines the opening of the air throttle 62. Another purpose for the cam 68 is to open the air throttle 62 when the fuel throttle 12 is first opened. The air throttle 62 should only be opened slightly under this condition as it is necessary to give the fuel time to get ahead of the air during acceleration.

Once the fuel throttle 12 stops moving the air throttle continues to move under the influence of the increased fuel pressure in the chamber 34. The air throttle '62 is thus moving at the moment When the automatic means take over and it continues to move until checked by the suction in the air chamber 22 -acting on the d-iaphragm 28. During the interval when the inlet valve 94 is closed the fuel continues to discharge Von to the screen 88. When the valve 94 opens the fuel deposited on the screen 88 is picked up and vaporized. The valve 89 admits fuel through openings 9| from pipes 'I6 and 'I1 to the pipe 'M 'Ihe restriction formed to the right of the lip of the valve 89 restricts the flow of fuel automatically once the empirical control responsive to the valve 12 admits sufficient fuel to allow the diaphragms 28, 32, 82 and 84 to function.

What I claim is:

1. Means for fuel distribution in an internal combustion engine 0f the multi-cylinder type having a plurality of intermittently opened inlet valves and inlet ports associated therewith comprising means for continuously injecting a metered quantity of fuel into each port, a screen adjacent to each port adapted to absorb the fuel deposited thereon, said screens being so located that the air flowing through and over the screens absorbs the fuel deposited on said screens in the periods when the inlet valves are closed and the screen permits the air to 'respray the fuel back into the air stream during the periods when the inlet valves are open.

2. A multi-cylinder internal combustion engine, an air inlet, an air inlet manifold connected thereto having a plurality of air ports, a fuel inlet manifold having fuel discharge ports continuously open and discharging into each air port, a source of fuel under pressure, a venturi in the air inlet, automatic fuel ow restricting means responsive to the suction in said venturi and in which there is a screen in each air inlet port so located that the fuel discharged during the period that the engine inlet valve is closed is caught on said screen.

STANLEY M. UDALE.

REFERENCES CITED The following references .are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,359,314 Barto Nov. 16, 1920 1,597,882 Hackethal Aug. 31, 1926 2,330,650 Weiche Sept. 28, 1943 2,382,625 Garretson Aug. 14, 1945 2,399,077 Udale Apr. 23, 1946 2,406,115 Stephan Aug. 20, 1946

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