US2316300A

US2316300A - Control for fuel supplies

Info

Publication number: US2316300A
Application number: US353782A
Authority: US
Inventors: Stanley M Udale
Original assignee: Individual
Current assignee: Individual
Priority date: 1940-08-23
Filing date: 1940-08-23
Publication date: 1943-04-13
Anticipated expiration: 1960-04-13

Description

Patented Apia l3, i943 CQN'I'ROL FOR FUEL SUPPLIES Stanley M. Udale, Detroit, when, assignorto George M. Holley and Earl Holley Application August 23, 1940, Serial No. 353,782

3 Claims.

The object of this invention is to control the rate of fuel flow to either a carburetor or to a fuel injection system by means of the air flow through a venturi and the flow of the fuel through a fuel venturi.

In the drawing, the figure shows diagrammatically the application of the device to a carburetor.

In the figure, 1B is the air entrance controlled by two valves ii and it connected by linkage is. which valves in the position shown permit warm air to enter the air entrance l8. Associated with the air venturi M is an annular chamber i 5 communicating through the opening it with the throat of the venturi i l. 3? is the correspondlng fuel venturi which derives its fuel from the fuel pipe iii, the fuel flowing to the chamber l9 and down past the needle 213 through a passage 25 to the fuel outlet 22, which fuel outlet is controlled by a needle 23, which needle is controlled. by a bell crank lever 2 3 mounted on the pin '25. The needle 25 is connected through this bell crank lever with the rod ill and is kept in engagement by means of the compressed spring 26 which is adjusted by the threaded screw 27. The rod 28 carries an enlargement 352 located in the throat of the venturi ill The diaphragm 28 is responsive to the fuel pressure in the chamher it). The chamber 29 above the diaphragm 28 is therefore at the pressure existing in the throat of the fuel venturi ll, for the reason that the passage Jill connects the throat of the venturi ll with the chamber A rod 3i connects the diaphragm 28 and the rod at with another diaphragm 3?. which forms the upper wall of a chamber 33.

The pin 3i slides through an opening in the Wall 35 which forms the partition between the chamber l gand the chamber 33. A small quan tity of fuel therefore leaks past the pin' 3! into the chamber 33 and so finds its way to the annular chamber it and so to the passage 35, where it discharges through the openings 38 and 37. A chamber 39 is located above the diaphragm 32 and is connected through a passage all withthe annular chamber 9 and so with the openings ill in the outlet from the venturi M. An aneroid barometer 12 operates through a lever 43 with a valve 44 which at high altitude permits a flow of air from the chamber 39 to the chamber 33 This is the Well known altitude correction to correct for the changes of density in the air.

In order that the delay inevitable between the opening of the-throttle 38 and the opening of the needle valve 23 does not disturb the mixture of the delay above referred to.

Operation Assuming that the engine connected to this particular carburetor is already running, then the throttle 38 causes a suction at the outlet 3? located near the downstream lip of the throttle so as to cause air flow from the opening 36, causing the idle fuel to be drawn down the-passage from the annular chamber l5 and so from the chamber This causes a slight suction in the chamber 33 which increases as the throttle opens. Later when the throttle opens beyond the range of 35, ill, the suction in the throat of the venturi id increases still more and the diaphragln descends compressing the spring '25 and opening the needle 23. thereby causing'an increase in the fuel flow through the venturi ll.

which causes the diaphragm 28 to rise because I of the suction in the chamber 29. A balance is thus reached in which the mixture ratio is deterruined by the relative area of the. throats of the venturis ll and i i and therefore by the diameter of the rod 233 at the throat and the enlargement M32 is located here.

It is desirable at extremely low fuel flows and at extremely high fuel flows that the mixture ratio should be rich, richer by say 50%, than the cruising lean mixture ratio. To attain this result the rod at has a definite contour as, indicated by the enlargement 32. When the throat of the venturi ll is small a relatively small fuel flow will cause a great suction in the chamber 29 and therefore will balance a relatively great air flow through the venturi i4. In other words, a lean mixture will result. When the throat of the fuel venturi ll is large a relatively large flow through the venturi i! is required to balance a relatively smaller flow through the venturi it. In other words, a rich mixture results. Although it is not absolutely necessary a bumper spring M is provided above the diaphragm 32. The enlargement I02 in the rod 20 thus controls the trance a streamlined obstruction located in the throat of said fuel venturi, aventuri in said en-' trance, an outlet from said fuel venturi a valve located some distance away from said venturi in said outlet from said fuel venturi, a diaphragm responsive to the pressure difference created by the fuel venturi, a second diaphragm responsive to the pressure difference created by the air venturi, manual means for controlling the air throttle, means for rigidly connecting the two diaphragms together, said diaphragms being adapted to'be in equilibrium when subjected to the fuel and air pressures corresponding to the normal fuel and air flows, said connecting means being also connected to the fuel throttle valve and to the streamlined obstruction located in the a second diaphragmresponsive on one side to the auction in the throat of the air venturi, and on the other side to the normal pressure in the air e, means for rigidly. connecting the two diaphragms together, said diaphragms bein adapted to be in equilibrium when subjected to the fuel and air pressures corresponding to the normal fuel and air flowsJaid connecting means being also connected to the fuel throttle valve 10 and to the streamlined obstruction located in the throat of the said fuel venturi so as to form therev with an automatically variable throat and in which the maximum diameter of the obstruction is located at theminimum diameter of the venturi at a fuel flow intermediate the maximum and 0 through said venturi, said valve constituting the throat of the said fuel venturi so asto form therewith an automatically variable throat and ,a fuel entrance, 9. fuel passage conducting fuel to said engine, a fuel venturi therein, a streamlined obstruction located'in the thmat of said fuel venturi; an outlet orifice located in said fuel only movable obstruction in the air passage, a fuel entrance, a fuel venturi therein, an outlet from said venturi, a streamlined obstruction located in the throat of said venturi, a fuel throttle valve located some distance away from said venturi in said outlet from said venturi, a diaphragm responsive to the pressure drop in the throat of the fuel venturi, a second diaphragm responsive to the drop in the throat of the air venturi, means for rigidly connecting the two diaphragms topassage adapted to discharge fuel into said air passage, a fuel throttle valve regulating the size ofsaid orifice, a diaphragm responsive on one side to the fuel pressure and on the other side to the pressure in the throat of said fuel venturi,

gether, said diaphragms being adapted to be in equilibrium when subjected to the fuel and air pressures corresponding to the'normal fuel and air flows, said connecting means being also connected'to the fuel' throttle valve and to the streamlined obstruction located in the throat of said fuel venturi for moving said obstruction relative to said venturi for the purpose of varying the effective throat diameter of said fuel venturi.

STANLEY M. UDALE.