US2472734A - Fuel control system - Google Patents

Description

June 1949- M. J. THOMAS ETAL 2,472,734 FUEL com-nor SYSTEM Filed ne 27. 1946 2 Sheets-Sheet 1 A TTOP/VE') June 7,1949.

M. J. THOMAS ETAL 2,412,734

FUEL CONTROL SYS TE! 2 Sheets-Sheet 2 Filed June 27. 1946 -Figurel;

Patented June 7,1949 7 FUEL CONTBOLISYSTEM Michael J. Thomas, Birmingham, and Guy 0.

Fricke, Pleasantridge, Mich... assign orsto Bendix AviationiCorpor'ation, South Bend, Ind.,

acorporation of Delaware Application June 27, 1946, Serial No. war-14' -11 Claims. (01.123-119) 1 a This invention relates to fuel supply systems or devices for internal combustion engines and more a rotor is operatively disposed. The rotor is *attached to a shaft 22 by a key 24, said shaft particularly to devices or systems in which liquid fuel is supplied under positive pressure.

An important. object ,of the invention is to provide a fuel fceding'system in which thefuel flow is automatically regulated in accordance with certain engine variables such as, for example engine speed and engine charging pressure.

Another object of the invention is to provide a device of this character that comprises a simple unit which is effective and'reliable in operation.

This fuel supply system, while especially .applicable to fuel supply systems of the character hereinafter particularly described, is not limited to such uses, but is obviously available, with or 'without modification, in a great variety of cases 'where fuel is intended to be supplied under more or less analogous conditions in an internal compreferably being driven by the engine although it maybe otherwise operated.- Vanes 26 and 21 are slidably received in recesses; 28 and 28 provided therefor and the inner ends of'said vanes are adapted to engage the periphery of the rotor, the rotor being mounted on shaft 22 and having three equally spaced longitudinal portions for Further objects and advantages of. the inven- I tion will be apparent, to those skilled inthe art,

' from the following detailed description, taken in connection with the accompanying drawings. From thedisclosed embodiments, skilled persons will understand that many variations may be made without departing from the principles disclosed, and we contemplate the employment of any structures, arrangements, or modes of operation that are properly within the scope of the appended claims. I I

In the drawings:

Figure 1 is a schematic view of a fuel system embodying the present invention;

Figure 2 is a section taken on line 2-2 of casethey are given a further differing reference character.

Referring first to Figure 1, there is shown a 'fuel pump indicatedgenerally at ID in a housing l2 to one end of which is secured an extension I 4. The pump, Figures 1 and 2, includes a pump stator it having an interior chamber ill in which operatively engaging the peripheral wall of said chamber l8. The vanesare urged against the surface of the rotor by springs 88 and 3|. Fuel enters the pump through the inlet 32' which communicates with the interior of chamber I8 by way of passages 34 and 35, and fuel is discharged from chamber l8 by way of passages 38 and 31.

The passages 34 and 35 are located adjacent one side of the vanes 28 and 21 and the inlets 38 and 39 of passages 36 and 31 are located adjacent the other side of said vanes. As shown, the passages 36 and 31 communicate with a passage 48 which communicates with a chamber 42 through a port 43 controlled by a valve 44. The upper wall of chamber 42 is closed by a flexible diaphragm 46 which has spring retainers 48 and 50 secured thereto, adjacent the central portion thereof, by a rivet 52. A spring 54 reacts between the spring retainers 48 and a flange 58 of the valve 44 and a spring 58 reacts between the spring retainers 58 and a flanged spring retainer 88 of a plunger 62 which is slidably received in an extension 84 of a housing 66. The housing 88, together with the diaphragm 48, defines a chamber 68. Chamber 42 is connected with the passage 34 by a passage 12 comprising a by-pass from the discharge side having orifice 13 therein to the intake side of the pump.

Fuel discharged by the pump and conveyed by passages 38 and 31 passes through passage 40 into a chamber 18 in a housing l2 through which shaft 22 extends. Within thechamber I6 is a sleeve 18 which is keyed at 88 to said shaft to prevent rotation between the sleeve and shaft,

but said sleeve has a limited amount of longitudinal movement on the shaft which is permitted by a groove 82 in which said key is disposed. The sleeve is provided with an annular flange 84 against which one end of a spring 86 reacts to urge said sleeve to the left, as shown in Figure 1. The opposite end of the spring 88 reacts against a spring retainer 88 which is limited in its movement to the right, as shown in Figure 1, by a spring clip 90 received in an annular groove provided therefor in the shaft 22. A fixed orifice plate 82, Figures -1 and 3, is secured to the extens ion I4 by any suitable means such as screws 04 received in countersunk holes 06 in said plate 02. v

Rotatable on shaft 22, between the plate 02 and the sleeve 18 is a baffle plate 08 which has a serrated or toothed peripheral edge I00, Figures 4 and 5, and a flange portion I02 which has a toothed end portion I04. The teeth I04 are adapted to be engaged by corresponding teeth in the adjacent face of the flange 84 of sleeve 18. This arrangement permits rotatable adjustment of the plate 08 relative to the sleeve 18 for varying the timing of the passage of fuel through orifices I06 in the plate 08 which are in subs antially the same circumferential plane as orifices I08 in the fixed plate 02. However this arrangement prevents accidental rotation of plate 08 on the shaft. Adjustment of the plate 08 relative to sleeve 18 may be effected by any suitable instrument which may be inserted in an opening into chamber 16, said opening being normally closed by a threaded plu H0. The orifices I08 are in constant communication with fuel discharge passages II2 which communicate with conduits I I4 leading to fuel discharge nozzles, indicated generally at I I6.

The nozzles II6 include a fitting H8 and a lateral, externally threaded extension I20 which is screwed into an opening in a boss I22 of intake manifold I24 of the engine, not shown. The fitting II8 has a longitudinal extending fuel passage I26 and a branch passage I28 which is controlled by a ball valve I30 urged in the closing direction by a spring I32 which reacts between said ball and a difiusing cup I34 which has discharge passages I36 therein. A gasket I38 is provided between the fitting H8 and the boss I22 to seal same against leakage between the parts. If one discharge nozzle is adapted to supply fuel to more than one cylinder the nozzle may be provided with a plurality of fuel conduits for supplying the required amount of fuel for the additional cylinders. In the drawings, supply nozzle I I6 is provided with conduits H4 and I30, the latter conduit being connected to the source of fuel through another conduit II 4, discharge passage H2 and orifice I08. As shown in Figure 1, one conduit I I4 leads to one side of the manifold and the other conduit 4 may lead to the opposite side of the manifold for connection for fuel nozzles disposed therein. Preferably, though not necessarily, the nozzles discharge adjacent mixture outlets I40 of the manifold to thereby effect improved mixture distribution to the engine in which the manifold I24 has an inlet section I 42 which is controlled by throttle valve I44 mounted on a shaft I46 to which a throttle lever I48 is attached. The free end of lever I48 is connected by a rod I50 with the conventional accelerator pedal mechanism, not shown.

Control of the effective pump discharge pressure is regulated in accordance with manifold vacuum or engine charging pressure and engine speed. The manifold vacuum is transmitted from the manifold I 24, posterior to the throttle valve I44, by a conduit I52 which communicates with the chamber 68 thereby subjecting thediaphragm 46 to said manifold vacuum on said engine charging pressure to thereby vary the effective closing force of the valve 44.

The speed responsive device for controlling the effective closing force of valve 44 in cooperation with the manifold vacuum comprises a fiy ball governor having a yoke comprising arms I in the central collar I62 secured to the shaft 22' by a pin I64. To each arm I60 is attached a lever I65 pivoted at I66 to said arms and having weighted free ends I68, said levers I65 being adapted to move outwardly in response to centrifugal force when the shaft 22 is rotated; each lever is provided with a laterally extending arm I10 which is adapted to engage the adjacent face of a flange I12 formed on a sleeve I14 slidable on the. shaft 22, said sleeve being adapted to be moved to the left, as shown in Figure 1, by the arms I65. The opposite end of sleeve I14 is adapted to engage a bifurcated arm I16 secured to a collar I 18 which is fixed to a shaft I by a set screw I82. The shaft I80 is journalled in the walls of a housing I84 which encloses the governor mechanism and is attached to the extension I4 by any suitable means such as screws, not shown. Also attached to the shaft I80 is a lever I85 connected to an arm I86 of a bell crank by means of a rod I88. The bell crank is pivoted at I00 and has an arm or cam I02 adapted to engage the plunger 62 to effect longitudinal movement thereof. The cam surface of the bell crank may be contoured to provide an economical fuel-to-air ratio for normal engine operation and an enriched mixture when the engine is under heavy load. A spring I94 has a connection with lever I85 and another connection with a fixed arm I06 and urges the lever I85"in a counterclockwise direction, as shown in Figure 1. When the shaft 22 is rotated to cause the arms I64 to move outwardly the lever I85 is moved in a clockwise direction, as shown in Figure 1, thereby effecting inward movement of the plunger 62.

It is to be noted that suitable bearings are provided for the shaft 22, there being a bearing I05 in the housing I2, bearing 200 in the extension I4 and a bearing 202 in the closed end of the housing I84. In order to prevent the escape of fuel past the shaft 22, seals 204 and 206 are provided in the housing I2 and extension I4 respectively.

- Operation During operation of the device the rotor 25 pumps fuel into the passages 36 and 31 through the passage 40 and into the chamber 16. A portion of said fuel however is by-passed through 0 tion determines the amount of fuel by-passed and consequently determines the discharge pressure of the fuel conveyed to the chamber 16. As the shaft rotates, the orifices I06 in the plate 08 intermittently communicate or register with the orifices I08 in a fixed plate 02. During the periods said orifices I06 and I08 are in register, fuel passes therethrough and into the conduits II2, thence through the conduits II4 to the fuel nozzles II6. Such fuel is then discharged into the intake manifold I24 by way of the orifices I36 in the diffuser cup I34. It is to be noted that for every revolution of the shaft 22 the orifices I06 and I08 are in register or communication for passing fuel throughout a fixed portion of each revolution regardless of the speed'of rotation of said shaft 22. Thus a fixed quantity of fuel will flow through said orifices for a given pump pres- Sure. I

By varying the effective pressure of springs 54 and 58 urging the valve 44 in the closing direction variations in the effective pump discharge pressure are secured. With high suction in the manifold I24, the diaphragm will be urged outof the effective forces tendingto close valve 44.

Conversely a drop in manifold suction will permit said springs to exert a greater effective closing force on said valve. Thus with the throttle in a substantially closed or idling position, at which time the manifold vacuum is high, the valve 44 will permit a relatively large quantity of fuel to be by-passed, and thus the fuel pressure in chamber 16 will be relatively low for providing the proper quantity of fuel for the desired fuel mixture. Should the throttle valve I be opened, as for acceleration of the engine, the vacuum in chamber 68 will drop, in other words, the pressure in said chamber will rise, permitting the springs 54 and 58 to exert a greater effective closing force on the valve 44, thereby effecting a rise in the pressure of fuel in chamber 16 and effecting a greater quantity of fuel to be discharged from the nozzles Iii, thus providing an increase in fuel flow corresponding to an increase in air air flow accompanying an acceleration.

At the same time, as the shaft 22 is rotated, the free ends of the levers I will move outwardly under the influence of centrifugal force and effect clockwise movement of the lever I85 which in turn will effect an inward movement of the plunger 62. At relatively low speeds the influence of the governor will be relatively slight. As the speed of the engine increases the arms I64 move outwardly and effect inward movement of the plunger 82 thereby increasing the effective valve closing force of springs 54 and 50 thereby increasing the fuel pressure in chamber "I6 and providing for an increase in fuel flow as required by the increase in air flow accompanying the increased engine speed.

Figure 6 In the arrangement shown in Figure 6 a governor throttle 2 III is provided in the air inlet passage ll2; the valve Ill is mounted on a shaft M2 which has a lever Ill secured thereto adjacent one end. The free end of lever 2 is connected by a rod II to the free end of the lever I85.

With this arrangement the top speed of the engine may be limited by action of the gover tages, the arrangements hereinabove described being merely preferred embodiments.

We claim:

1'. In a fuel supply system for an internal combustion engine having an intake manifold: a fuel pump for receiving fuel from a source and for delivering'the fuel to said manifold; apassage from the outlet side ofthe pump for said fuel: a'fuel nozzle connected with said'passage; a bypass from the outlet side to the inlet side of the pump; a valve for controlling the flow of. fuel through said by-pass, a yieldable means for urgingthe valve toward the closed position; and

means operative throughout .the engine operating range for varying the effective force tending to close said valve in accordance with engine speed and. charging pressure. I

2. In a fuel system for an internal combustion connected with said passage; a by-pass from the outlet side to the inlet side of the pump; a valve controlling said by-pass'; yielding means urging the valve in the closing direction; means for varying the effective force of said yielding means in accordance with engine charging pressure; and means responsive to engine speed for increasing the valve closing force of said yielding means on increase in engine speed, said pressure and speed responsive means being operative throughout substantially the full engine operating range.

3. The invention defined by claim 2 wherein there is a fixed orifice and a rotatable plate having openings therein adapted to register with the fixed orifice upon rotation of said plate.

4. In a fuel system for an internal combustion engine: a sliding vane type of pump having an inlet and an outlet; said pump receiving fuel from a suitable source; a by-pass from the outlet to the inlet side of the pump; a valve controlling said by-pass; yielding means urging the valve in the closing direction; a shaft for driving said pump and adapted to be operatively connected with the engine; a fuel passage from the outlet side of the pump and having a plurality of connections with the engine; a fixed orifice for each of said connections, said orifices being circumferentially arranged about the shaft in radially spaced relationship; a rotatable disc mounted on the shaft and having at least one opening therein adapted to intermittently register with said orifices upon rotation of the shaft; a. device connected with the shaft and responsive to the speed 7 thereof; means connecting said device with the yielding means for varying the effective force thereof; and means responsive to engine charging pressure for modifying the effect of the device on said yielding means.

5. The invention defined by claim 4 wherein thegdisc-is rotatably adjustable on the shaft.

6. The invention defined by claim 4 wherein there is a clutch interposed between the shaft and the disc whereby the rotational position of the plate on the shaft is adjustable.

'7. The invention defined by claim 4 wherein the device comprises a fiyball governor.

8. The invention defined by claim 4 wherein the engine includes an intake manifold having an inlet; a. valve controlling said inlet; and means connecting said valve with said device whereby the quantity. of fluid entering the manifold is controlled in accordance with engine speed.

'9. In a fuel system for an internal combustion engine: a variable output fuel pump; a fuel conduit connecting the pump with the engine; a device responsive to engine speed for varying the output of the pump; and means responsive to engine charging pressure for modifying the effect of the speed responsive device in varying the pump output, .said speed responsive device and pressure responsive means being operative throughout the engine operating range.

10. In a fluid metering device: a shaft; a fixed member on the shaft, said shaft being rotatable therein; a plurality of metering orifices in the member disposed annularly about the shaft in spaced relation with each other; a plate mounted on the shaft and adapted to move longitudinally thereon, said plate having at least one orifice in substantially the same annular plane as the first mentioned orifices; peripheral teeth on the plate: a plurality of teeth on one face of the plate;

7 engine having an intake manifold: a fuel pump 76 a sleeve on the shaft held against rotation thereon but having limited longitudinal movement:

teeth adjacent one end of the sleeve adapted to engage the teeth on the side of the plate; and yielding means urging the sleeve toward the plate.

11. In a fuel system for an internal combustion engine: a variable output fuel pump having an inlet and an outlet; means for connecting the pump with the engine for operation thereby: a device responsive to engine speed operative throughout the engine operating range for varying the output of the pump; a device responsive to manifold vacuum for varying the output of the pump; a fuel conduit leading from the pump to the engine intake manifold; a fuel nozzle with pressedwvalve closing the nozzle fuel passage.

MICHAEL J. THOMAS. GUY C; FRICKE.

8 REFERENCES crrEn The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,267,460 Salfeld Ma 28, 1918 1,597,787 Hausser et a1. Aug. 31, 1926 2,136,959 Winfield Nov. 15, 1938 2,414,617 Summers Jan. 21, 1947 OTHER REFERENCES Ser. No. 314,190, Hurst (A. P. C.), pub. May which the conduit is connected and a spring- 11,1943.

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