US2949903A

US2949903A - Charge forming device

Info

Publication number: US2949903A
Application number: US675699A
Authority: US
Inventors: Howard H Dietrich
Original assignee: Motors Liquidation Co
Current assignee: Motors Liquidation Co
Priority date: 1957-08-01
Filing date: 1957-08-01
Publication date: 1960-08-23
Anticipated expiration: 1977-08-23

Description

Aug' 23, 1950 H. H. DIETRICH v2,949,903

CHARGE FORMING DEVICE Filed Aug. l. 1957 eff 3 Sheets-Sheet 1 Q CDCQD) A T TORNEY.

Aug. 23, 1960 H. H. DIETRICH CHARGE FORMING DEVICE Filed Aug. 1, 1957 3 Sheets-Sheet 2 ugo 2?9 1960 H. H. DIETRICH 2,949,903

CHARGE FORMING DEVICE Filed Aug. l, 1957 3 Sheets-Sheet 3 T ROTTLE THROTTLE "THRO E Hmm-ME 20 rf/RorrL/s /0 THEO y INVENTOR. #59 J 299999119099999 BY o f i Z'/ 4 TTORNE Y- Unitd Sie@ Patent 0 2,949,903 cHARGEroRMmG DEVICE Howard H. Dietrich, Rochester, N.Y., assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware FiledAng. 1, v19e/aser. No. 615,699l

zo claims. (c1. '12s-119) The present device relates to a charge forming mechanism for an internal combustion engine and which mechanisrn may be utilized as a carburetor by employing only one fuel nozzle or asa fuel injection system in which event individual fuel nozzlesare provided for each of the cylinders of the engine. In the present description the system will be described as a fuel injection system in which the individual fuelnozzles are provided.

The presentvcharge forming vdevice is of they closed or non-vented type which renders it highly desirable for use with high vapor pressure fuels. In utilizing the present non-vented system the lfuel is maintained under pressure preventing vaporiza-tion and the attendant vafpor` lock potential as well as the loss of fuel which accompanics boiling.

It is a further purpose ofthe present invention to provide la charge .forming device in which the quantity of fuel supplied. is determined solely by the position of the throttle and engine speed. The present charge forming device has certain advantages over fuel injection systems of the speed-density or mass air flow types in which the quantity of fuelmetered to the engiues cylinders is determined by such variables as manifold vacuum or venturi vacuum. Systems controlling the flow of fuel through manifold or venturi vacuum forces have the inherent disadvantage of imposing a hysteresis or time lag in supplying fuel. As a result of the inability of the vacuum controlled systems to respond-immediately to changes in demand certain undesirable transient operating conditions arise particularly during idle, olf-idle and accelerating operationgiving rise to flat spots on the power curve otherwise m-anifested as -a slight -lag in power under certain demand conditions.

In the present charge forming device, a mechanical control system has been developed which insures immediate response to changes in either or both operator or engine demand. In the present system a fuel metering valve is directly controlled by aplunal-ity of levers 'and cams which combine to-tailor the -fuel supply to the exact needs of the engine and desires of the operator. By

the unique utilization of levers and cams the present fuel injection system' may be easily adapted for use with different engines by merely-regulating 4the levers or by the simple interchange of cams which will tailor'the engines fuel supply to 'the particular engine operating characteristics. In this way a higblyversatile fuel injection system is provided and which additionally is capable of relatively inexpensive manufacture when contrasted with present fuel injection systems.

The details of the present invention as well as other objects and advantages fare set forth in the description which follows.

In the drawings:

`Figures 1, 2 and 2a are diagrammatic representations of the subject fuel system;

Figure 3 shows a portion of the lever control SYStetIll as shifted fromthe position of Figure 1; and

Figure 4 is a graph indicating fuel requirements engine speed.

In order to simply illustrate the present fuel injection system the various components have been shown diagrammatically. A low pressure make-up fuel pump 12 draws fuel from a fuel reservoir indicated at 10 and supplies it through a conduit 14 to the inlet side of an engine speed responsive high pressure pump 16 disposed in casing 17. High pressure pump .16 is driven by a shaft is delivered through a conduit 24 to a fuel metering valve 26.

a spindle type member 30 is slidably-disposed.r A spring element 3-2 is adapted tobias the valve member 30 to thel right, however, the output pressure from pump 16 is conveyed through a branch conduit 34 to the opposite'. end of-the valve element -and normally biases'the element to a

position communicating conduits

20 and 24 for the delivery of high pressurefuel to the metering valve 26.-v A lowpressure branch conduit 36 also com- A. municates with casing 28 through

ports

38 and 40. `Duri ing cranking when the output of high pressure pump 16 Y, is low, the pressure lof the pump 12 usuallyexceeds that of the high pressure pump and spring 32l will bias element 30 to the right, as shown, in which event fuel will be supplied to the metering valve throughiconduit 36.l It

of the element.

ing the pump pulsations. A stop in casing 28 to limit the travel of spindle 30.

The fuel metering valve 26 includes a casing 44 having a bore 46 formed therethrough and slidably receiving a valve element 48. Valve element 48 includes a longituf'4 dinally extending diametrical slot 50 formed therein and which slot variously extends into chambers 52 and 54 formed in the casing member 44 and separated by'a'partition or wall 56. Conduit 24 supplies fuel under pressure to chamber S2 while a conduit A58`delivers fuel from` chamber 54 to the individual cylinder fuel nozzles 60 disposed in cylinder intake passages 61, only one of which is shown. The quantity of fuel metered to the nozzles 60 is determined by the longitudinal position of -slot 50 relative `to bore' chambers 52 and S4. The prin-v ciple of operation of the metering valve l26 is based on the concept of changing the area of the metering slot 50 exposed to fuel inlet chamber 52 in accordance with engine speed and throttle position As the slot 5t)l moves to the left with the valve element 48 increasing the slot area exposed to the inlet fuel chamber, an increasedl quantity* of fuel will flow from chamber 52 to output chamber 54 and hence to the nozzles 60. It is the area' of slot 50 in chamber 52 that determines the quantity of flow since the slot Iarea in chamber 54 is always large enough to pass any fuel quantity metered from chamber 52 i The precise form ofthe slot50 is not limited to that shown in the drawings but may be of any configuration consistent with Vthe basic premise that the area of the slot will be capable of varying as a function of engine speed and operator demand by actuating means to be subsequentlyfdiscussed. In order to insure relatively frictionless operation of the slidable valve element -48` a conduits 62 Iand 64, which respectively branch olf from the fuel inlet and outlet passages 24sand'58, commun- Patented Aug.. 23,7 1

Valve mechanism 22 includes a casing 28 within which? pair o f- Y 3 cateY with casing ports 66'and` 68 to deliver small quantities of fuel to the casing bore 46 enabling a small amount of fuel to flow between the valve element 48 and the borefor lubrication purposes and to purge the sliding surfaces of any impurities insuring relativelyfric.- tionless movement of the valveelement. Fuelfrom passages 62 and 64 flow-s in both directions along the valve element 48 and the controlled leakage from the. valve is returned to the metering casing 70 and back to the fuel supply tank through drain passage 72.

It is intended that thev quantity of fuel metered by the valve 26 be solely determined by the change of area of the metering slot 52 as described. To preclude pressure changes acrossY the metering valve 26 from aifecting the quantity of fuel metered, valve device 80 isl provided for maintaining thepressure drop across the metering valve at a controlled or determinate value. pressure drop control valve includes a casing having an enlarged portion 84 vwithin which. a diaphragm member 86 is peripherally clamped. A reduced portion 88 of thecasing is adapted to slidably supporta needle type valve element 90 having an enlarged end 92 adapted to rabuttingly engage the `diaphragm 86. It is imperative that the valve element 90 be mountedsubstantially without friction` in the casing portion 88. Accordingly, the valve 'element supporting Walls 94 and 96 have suiciently large needle valve supporting openings to insure relatively lfrictionless support of valve element 90. Further, the enlarged end 92 of the valve element merely abuts the diaphragm 86 and is not fixed thereto preventing the diaphragm `from otherwise cooking the valve element 90 which Would add frictionalY resistance to its movement.

The other end 98 of the valve element 90 is tapered and coacts with an orifice or opening 100 in casing wall 102 to provide an adjustable oriiice. A spring element 104V isdisposed intermediate the head portion 92 of the valve element 90 and the casing portion 84 biasing the valve element into engagement with the diaphragm 86. An additional spring element 106 is biased between the diaphragm 86 and adjustable seat 108 supported within casing portion 84' biasing thediaphragm and valve element Iin a direction restricting ow through orifice 100. Fuel under pressure from the input side of the metering valve 26 is delivered through a conduit 110 .to the pressure drop control valve casing at ports 112 and 114.

Thev fuel under pressure from the output side of' theV metering valve 26' is conducted to casing portion 84 through a conduit 116 which through a por-t 118 admits this fuel to the chamber 120 defined by the casing 84 and the diaphragm 86. Thus the output' pressure from the metering valve 2'6 and the spring 106 tend to urge the needle valve 90 to the right or flow restricting direction while the input metering valve pressure tends to urge the valve in a leftw'ard or flow increasing direction. 'Ihus as either the metering valve input or output 'pressure changes, the pressure drop control valve will insure a corresponding change'v in the other pressure. To illustrate, if the output pressure in conduit 1116 increases, the pressure increase in chamber 120 will cause diaphragm 86 tom0vethe needle valve 90 to the right to restrict flow through'the'orice 100 which in turn increases the pressure in conduits 110" and 24. While the pressure dropv across the metering valve device 80 need not necessarily be constant, the pressure drop control valve will insure that the pressure drop across the valve will in some fixed proportion toother control yforces and in this way insures that themetering of fuel through the va-lve 26 Will be determined solely by throttle position and' engine speed as will subsequently be discussed. The fuel flow through the orifice -100 will v member 126 and; a. nur. 12s provides. means torvariabyi Theadjusting the pressure drop across the valve device and since liow is proportional to this pressure drop on a percentage basis, the adjustment serves to raise percentagewise the value of ow under any condition of operation. This fuel flow can be increased 'for -a large engine or decreased for a smaller engine on -a percent basis by adjusting the nut and` screw 128 and 126.

The individual cylinder fuel nozzles 60 are of the atmospheric type' shown generally in copending application Serial No. 512,175, Homfeld et'al., filed May 3l, 1955, and now abandoned.

Consistent with the desire to provide a closed or nonvented fuel system nozzles 60 are provided with a solenoid controlled valve 126 which will block the drainage of fuel through the nozzles after the engine is shut olf. In this manner the fuel systemremains charged with fuel for rapid restarting. A spring 131 normally biases valve 126 in a ilow blocking direction.- A solenoid 130 is connected in the ignition circuit sucli that Lwhen the ignition is closed the solenoid -i's energized to retract valve 127 permitting normal fuel flow; In lieu of the individual nozzle solenoid valves 127 a single valve may be utilized in conduit 58` .to perform the' same function.

As already noted, the 'quantity of'fuel supplied by the metering valve 26 to the atmospheric nozzles 60 is determined by the axialv position of the valve element 48 within Ithe casing 4'4 and as furtherVV noted as the valve element 48 isV moved to the left the quantity of. fuel supplied is increased. The remainderof the description will be devoted to the mechanism' whereby the longitudinal movement of the valve element 48A is tailored to the demands of the operatoras well' as engine speed.

Before proceeding to a description of the metering valve control mechanism it would'be well to first refer to the curves shown on the graph of Figure 4; The family of curves shown on the' graph represent the fuel requirements for given engine speedswith regard to various degrees of throttle opening' for a typical engine. These fuel requirements are well established values and it is the purpose of the present invention to provide a control mechanism capable of tailoring the quantity of fuel supplied by the metering valve-to the various requirements represented by such' curves.Y With the exception of the 10 throttle opening curve where the fuel requirements remain substantially constant, it is apparent that on the remaining curves that the fuel requirements increase with engine rpm'.I up to an engine speed beyond which the fuel requirements remain substantially constant. To illustrate in 'referringto the 30 throttle curve it will be seen'- that asV the engine reaches approximately 240 rpm. 'the fuel requirements of the engine remain substantially constant as the engine rpm. increases. The fact that the fuel curves lfor the various throttle positions Atend to ilatten out or become essentially constant beyond-a given. engine rpm. indicates one important requirement of suclra fuel control sys'- tem and that-is. that such acontrol cannot be solely dependent upon throttlewpositionialone. Accordingly, it is necessary that such control` system include a means responsive to engine Yspeedfor modifying the throttle actuation of the fuel meteringzv'alve.; 1 y

Referring nowl to the' metering valve control mechanism, it Will .be seen thatf the-slidable valve element 48 includes a portion 129 extendingfromfthe metering' valve casing 44 and which portion-is connected through a threaded coupling. '132,- Figure ll', to a lever section 134. For the present purposes portion 129-s kcoupling 132 and portion 134fwil1'be considered as a single' element. This element is pivotally connectedpto a lever 136 intermedia-te its ends and end 138 of which will for the present purposes be considered as a -iixed pivot point. The other end-of'lever 1361is` articulated tofa l'ever 140, the other end of which lis connected through alpin-and slot connection 142 to a lever 144i A connected through pin and slot connections 146'and 148l respectively to levers 150 and 152. Lever 152 has a lever 154 articulated thereto through a pin and slot connection 156 and which latter lever is slidably mounted in a supporting casing 158. Lever 154 terminates 'at its other end in a cam follower or roller member 160. Cam roller 160 is adapted to coact with a rotatable cam member 162 lixed upon a shaft 164 which is controlled by the position of the carburetor air throttle 166 disposed in air induction passage 167. For the present, end 168 of the lever 152' will be considered as a xed pivot.

Thus as the air throttle 166 is opened the cam 162 is rotated in a counterclockwise direction shifting lever 154 to the left similarly pivoting the

levers

152 and 144 in a counterclockwise direction about

pivotal connections

168 and 146 respectively. Lever 140 is in turn carried to the left rotating lever 136 about pivot 138 causing element 130-134 to move valve element 48 to the left to increase the area of the slot 50 exposed to the fuel input chamber 52. The throttle controlled cam 162 is thus adapted to increase the fuel supply in proportion to the degree of throttle opening. As may be seen on the curves of Figure 4, however, the relationship of fuel to throttle opening must be modified by other control forces to insure the proper fuel-air ratio under all engine speed conditions.

As thus far described, the fuel injection control system is responsive only to throttle position. In order to make the system function in accordance with the illustrative curves of Figure 4, an engine speed controlling device is provided generally at 170 and includes a plurality of speed responsive centn'fugally operated weights 172 pivotally mounted on the engine speed responsive shaft 18 also utilized to drive pump 16. The speed controlling mechanism 170 is disposed in an enlarged portion 174 of the pump casing 17. The engine speed responsive shaft 18 terminates within a recess in a co axially disposed lever 176 slidably supported at one end in the casing portion 174. Lever 176 connects with the speed responsive elements 172 through a flange 178, antifriction bearing members 180 and an intermediate plate 182 slidably mounted on shaft 18.

As engine speed increases the centrifugal weights 172 are thrown radially outwardly causing the inner cam surfaces 184 to move plate 182, bearings 180 and lever 176 axially to the left against the force of a spring 186 biasing these elements in the opposite direction.

Referring particularly to Figures 1 and 3, lever 176 includes a piu 188 adapted to coact with a slot 190 formed in leg 192 of lever 150 such that when the levers 176 and 192 are axially aligned, as shown in Figure 1, the axial movement of the pin 188 toward the leg 192 of lever 150 will cause the pin to move in the slot 190 resulting in the speed responsive mechanism 170 having no elfect on the fuel metering control. The purpose of this lost motion connection can best be understood by referring to the throttle curve of Figure 4 which, as noted, has substantially no slope and is a straight line. Thus with a 10 throttle opening it is not desired to perceptibly increase the quantity of fuel supplied to the engine with increases in engine speed. It is therefore possible to shape the cam 162 to set olf an increase in fuel flow to correspond with the values shown on the 10 throttle curve.

Since each curve for a particular throttle opening has a different slope it is necessary to provide means for adjusting the fuel controlled linkage mechanism for each degree of throttle opening. To this end, a fanning or slope determining cam 200 is provided. Cam 200 like cam 162 is eccentrically mounted on the air throttle shaft 164 and rotates in accordance with the various positions of the air throttle. The fanning cam 200 is connected to the metering control mechanism through a lever 202 which is xedly pivoted Iat end 204 and articulated at its other end to the L-shaped lever 150 at 206. As

noted, the fanning cam 200 is eccentrically mounted and' in' general is adapted to cause the lever 202 to be pivoted in a clockwise direction about pivot point 204 as.

is caused to pivot about pin 188 of lever 176. In so,

inclining the levers 150 and 176, Figure 3, it will be seen that as engine speed increases pin 188 is adapted to now engage the side of slot 190 imparting a counterclockwise movement to lever 150. In this way an addi-- tional leftward or metering valve flow increasing movement is imparted to the valve element 48.

As already noted, it is desired when -the throttle 166 is open between the 0 and the 10 positions that engine speed have no effect on the quantity of fuel supplied. Accordingly, the fanning cam surface has a substantially constant radius of curvature from its zero degree position to the 10 position. In this way with the throttle opened between the zero and 10 positions the

levers

176, 192 and 204 are Iaxially aligned in which event engine speed will not affect the quantity of fuel supplied to the nozzles 60. The surface of cam 200 is suitably contoured, in accordance with the curves of Figure 4,

so that throttle opening beyond 10 progressively in? creases the clockwise movement of the lever 202 thereby, at least initially, increasingthe slope of the fuel r.p.m. -curve as the degree of throttle opening increases.

As already 'noted in referring to the curves of Figure 4, as engine speed increases for any given throttle opening the fuel Vrequirements of the engine 4become substantially constant after a given speed. It is therefore necessary to provide means to insure this type of operation. Accordingly, the pin and slot connection 146 between the lower end of lever 144 and L-shaped lever is :formed to provide a run-out slot or cam surface 210. As engine speed increases with increased throttle opening, the L-shapedlever pin 212l will move the lower end of lever 144 in a' leftwardly direction, supra, and in so doing will approach the run-out slot 210. The

radius of curvature of the run-out slot or cam surface 210 is such that as the pin 212 enters this portion of the slot the radius of curvature of the slot is substantially concentric with the arcuate path of movement of the pinv about its pivot point 206 as rotated by the speed responsive device 170. Hence as the pin 212 moves within slot 210 substantially no further leftward movement of the lower end of the lever 144 will take place with increase in speed. Therefore, even though engine speed continues to increase and rotate the lever 150 in a counterclockwise direction, the run-out cam 210 will insure that no further increase in the fuel supplied will take place for a given throttle opening. In this way the fuel-r.p.m. curves for the various Idegrees of throttle opening areattened, e.g. slope made to approach zero,

conforming to the engine requirements as indicated in the y curves of Figure 4.

In order to vary the movement of pin 212-relative to cam slot 210 in accordance with throttle opening and hence the period through which the speed responsive mechanism is operative to increase the fuel supply with increase in engine speed, an additional or peel-olf cam 216 is provided. Like

cams

162 and 200, cam 216 is connected lto the air throttle` shaft 164. The peel-off cam 216 is articulated through a lever 218 and intermediate link 220 to metering control lever 144. Lever 218 is xedlly pivoted at one end and is adapted to be rota-ted in a counterclockwise direction by cam 216 with The counterclockwise vmovement of lever 218

lift levers

220 and 144 thereby increases inthrottle opening.

moving the cam slot 210 relatively away fromvpin 212 of lever 150. The result of this typevof actuation is to maintain the pin 212 in ,the straight portion of slot 222 ,for @longer Period 0f Haabaa@ aannemers them- '.'fl A charge forming device for an internal combus tion engine comprising a fuel source, pump means for pressurizing-the fuel from said fuel source, a fuel metering valve, conduit means connecting said pump means and said fuel metering valve whereby said pressurized fuel is delivered to said valve, said metering valve including an adjustable valve element for varying the quantity of fuel' owing through said valve, a fuel nozzle for supplyingv toincrease the fuel ow through said metering valve beyond a given engine speed.

f 2. A charge forming device for an internal combustion engine comprising a fuel source, pump means for pressurizing the-fuel from said fuel source, a fuel metering valve, conduit means connecting said pump means and said fuel metering valve whereby said pressurized fuel is delivered to said valve, said metering valve including an adjustable valve element for varying the quantity of fuel liowing through'said valve, a fuel nozzle for supplyiri'gf uel to each cylinder of the engine, conduit means communicating said metering valve with each of said fuel nozzles, a throttle valve for controlling the quantity of airfiiowV to the cylinders of the engine, lever means operatively connecting said throttle valve and said metering valve Vfor increasing the quantity of fuel flow through said nietringvalve as said throttle valve opens, engine speed responsive means connected to said lever means for increasing the flow of fuel through said metering-valve as engine speed increases, and throttle control means for rendering said engine speed responsive means inoperative to increase the fuel oW through said metering valve beyond a given engine speed, said throttle control means being adapted to vary the engine speed at which said engine speed responsive means is rendered inoperative.

t 3. A charge forming device for an internal combustion engine comprising a fuel source, pump means for pressurizing the fuel from said fuel source, a fuel metering valve, conduit means connecting said pump means and said metering valve whereby said pressurized fuel is deliyered tov said valve, said metering valve including an adjustable valve element for varying the quantity of fuel flowing through said valve, a fuel nozzle for supplying fuel to'eachrcylinder of the engine, conduit means communicating said metering valve with each of said fuel nozzles, a throttle valve for controlling the quantity of air ow to the cylinders of the engine, lever means `operatively connecting said throttle valve and said metering valvefor increasing the quantity of fuel flow through said metering valve Vas said throttle valve opens, engine speed responsive means connected to said lever means for increasing the flow of fuel through said metering valve as engine speed increases, throttle control means for rendering said engine speed responsive means inoperative to increase the fuel flow through said metering valve beyond a given engine speed, said throttle control means being adapted to vary the engine speed at which said engine' speed responsive means is rendered inoperative, and means for maintaining a controlled pressure drop across said metering valve.

T4., A charge forming device for an internal combustion engine comprising a fuel source, pump means for pressurizing the fuel from said fuel source, a fuel metering valve, conduit means connecting said pump means and said fuel metering valve whereby said pressurized fuel is deliveredtosaid valve, said metering valve including an'.` adjustable valve element for varying the'quantityoffueb valve as said throttle valve opens, engine speed responsive means connected to said lever means for increasing 'the flow of fuel through said metering valve as engine speed increases, and throttle control means for rendering said engine speed responsive means inoperative to increase the fuel ow through saidmetering valve beyond a given engine speed, and means for controlling the pressure drop across said metering valve to preclude fuel pressure variations from affecting the quantity of fuel supplied to the nozzles.

5. A charge forming device for an internal combustion i engine comprising a fuel source, first pump means for pressurizing the fuel from said fuel source, second pump means for supplying low pressure fuel to said irst pump' means, av fuel metering valve, conduit means adapted to connect said first orsecond pump means with said fuel metering valve, valve means in said conduit means for selectively connecting saidpfirst or second pump means with said metering valve, said metering valve including 1 an adjustable valve elementfor varying the quantity of vfuel flowing through said valve, a plurality of fuel nozzles for supplying fuel to the individual cylinders of the engine, conduit means communicating said metering valve with said fuel nozzles, a throttle valve 'for controlling the quantity-of air flow to the cylinders of the engine, lever means operatively connecting said throttle valve and said metering valve for increasing the quantity of fuel flow through Asaid metering valve as said throttle valve opens, engine Aspeed responsive means connected to said lever means for-increasing the flow of fuel through said metering valve as engine speed increases, andthrottle control means for rendering said engine speed responsive means inoperative to increase the fuel flow through said metering valve beyond a given engine speed.

-6. charge forming device as set forth in claim 5 in which said valve means is differentially responsive to the ypressures from said first and second pump means whereby said'valve will connect said second pump means with said fuel metering valve when the fuel pressure from saidfirst pump means drops below a given value.

V7 A charge forming device for an internal combustion engine comprising a fuel source, rst pump means for pressurizing the fuel from said fuel source, second pump means for supplying low pressure fuel to said first pump means, a fuel metering valve, conduit means adapted to ,connect said first or second pump means and said fuel lmeteringvalve, valve means in said conduit means for selectively connecting 'said iirst or second pump means with lsaid metering valve, said metering valve including an adjustable valve element for varying the quantity of fuel flowingthrough said valve, a plurality of fuel nozzles for supplying fuel to the individual cylinders of the engine, conduit means communicating said metering valve with said fuel nozzles, a throttle valve for controlling the quantity of air ow to the cylinders of the engine, lever meansoperatively connecting said throttle valve and said metering valve for increasing the quantity of fuel ow through said metering valve as said throttle' valve opens. engine speed responsive means connected to said lever means for increasing the flow of fuel through said metering valve as engine speed increases, throttle control means for rendering said engine speed responsive means inop erative to increase the fuel flow through said metering valve beyond a given engine speed, said throttle control means being adapted to vary the engine speed at which 1said lengine speed responsive means Lis rendered'inoper-a- 1 l tive, and means for controlling the' pressure drop across said metering valve.

8. A charge forming device as set forth iny claim 3 in which said pressure drop controlling means comprises a casing, a diaphragml dividing said casing into two chambers, a valve element fixed to said diaphragm for 4movement therewith and in communication with one of said chambers, passage means communicating said one charnber with the fuel source, an orifice in said passage means with which the valve element coacts, a first conduit connecting the output side of said fuel metering valve with said one chamber, and a second conduit for connecting the input side of the metering valve with the other chamber, the fuel pressure differential in said chambers acting on said diaphragm to cause the valve element to vary the orifice opening and tothereby maintain a controlled pressure drop across said metering valve.

9. A charge forming device for an internal combustion engine comprising air intake passage means for supplying air to the individual cylinders of the engine, a throttle valve disposed in said intake passage for controlling the quantity of air supplied to said cylinders, a nozzle disposed in said intake passage proximate each cylinder of the engine, a source of fuel, pump means for pressurizing the fuel from said fuel source, a metering valve, conduit means communicating said pump means with said metering valve for supplying pressurized fuel thereto, conduit means communicating said metering valve with each of said fuel nozzles, said metering valve` including an adjustable element for controlling the quantity of fuel sup` plied to said fuel nozzle means, a device for controlling the pressure drop across said metering valve, lever means connected to said slidable metering valve element, means operatively connecting said throttle valve yand said lever means for increasing the quantity of fuel flow through said metering valve as said throttle valve opens, engine speed responsive means operatively connected to said lever means for increasing the quantity of fuel flow through said metering valve as engine speed increases, throttle control means for rendering said engine` speed responsive means inoperative to increase fuel iiow above agiven engine speed, said throttle control means being adaptedY to vary the engine speed at which said engine speed responsive means is rendered inoperative in accordance with the various positions of said throttle valve, and temperature responsiven means fordlimiting the opening of said throttle valve until said engine is sufliciently warm.

10. A charge forming device for an internal combustion engine comprising air intake passage means for supplying air to the individual cylinders ofthe engine, a throttle valve disposed in said intak'e` passage for controlling the quantity of air supplied to said cylinders, a'nozzle disposed in said intake passage proximate each cylinder of the engine, a source of fuel, pump means for pressurizing the fuel from said fuel source, a metering valve, conduit means communicating said pump means' with said metering valve forV supplying pressurized fuel thereto, conduit means communicating said metering valve with said fuel nozzle means, said metering valve including an adjustable element for controlling the quantity of fuel supplied to said fuel nozzle means, a device for controlling the pressure drop across said metering valve, vlever meansjonf nected to said slidable metering valve element, -means operatively connecting said throttle valve andsaidlever means for increasing the quantity of fuel ow` through said metering valve as said throttleval'v'el opens, enginev speed responsive means operatively connected to said lever means for increasing the' quantity of fuel flow through said metering valve as engine'speed increases, throttle control means" for rendering said engine speed responsive meansinop'erativ'e to increase fuel iiow above a given engine speed, said throttle control means being adapted to vary the engineY speed at whic,li said engineA speed responsive means is"rendered'inoperative in accord?` ance with-- the various :positions` of said "throttlev'alve, and

engine temperature responsive means coacting said lever means for limiting the opening of said throttle valve u'ntil said engine is sufficiently Warm.

l ll. A charge forming device as set forth in claiml l0` in which` said temperature responsive means includes means for controlling idle fuel and air flow respectively.

1,2. A charge forming device for an internal combustion engine comprising a source of fuel under pressure," a fuel nozzle for each cylinder of the engine, a valve for supplying a metered quantity of fuel to each of said fuel nozzles, a throttle valve for controlling the quantity of air ow to said cylinders, control means operatively con'- nected intermediate said throttle valve and said metering' valve for controlling the quantity of fuel supplied to said nozzles in accordance with the position of said throttle,v engine speed responsive means for modifying the actua-v tion of said control means to increase the quantity of fuel,v

supplied to said nozzles as engine speed increases, ,and

throttle controlled means for rendering said engine ,speed responsive means inoperative to increase the fuel vflow through said metering valve beyond a given engine speed.V

13. A charge forming device for an internal combustion engine comprising a source of fuel under pressure, a fuel g nozzle for each cylinder of the engine, a valve for supplying a metered quantity of fuel to each of said fuel nozzles,'

a throttle valve for controlling the quantity of air ilow to said cylinders, control means operatively connectedl intermediate said throttle valve and said metering valve for controlling the quantity of fuel supplied to said nozzles in accordance with the position of said throttle,

engine speed responsive means for modifying the actua# tion of said control means to increase the quantity of fuel supplied to said nozzles as engine speed increases, throttle controlled means for rendering said engine speed respon-Y sive means inoperative to increase the fuel W through said metering valve beyond a xgiven engine speed,yand

means for controlling the pressure drop across said meter" nozzles in accordance with the position of said throttle,'

engine speed responsive means for modifying the actuation of said control means lto increase the quantity of fuel l supplied to said nozzles as engine speed increases,y throttle controlled means for rendering said engine speed' responsive means inoperative to increase the fuel flow through said metering valve beyond a given engine speed,

and engine temperature responsive means for iirniting the, opening movement of said throttle until said temperature reaches a given value.

l5. A charge forming device for `an internal combus-` tion engine comprising la source of fuel, high and lowy pressure pumps communicating with said fuel source, a'

fuel nozzle for each cylinder of the engine,v a valve'fo'r"y supplying va metered quantity of fuel to e-ach of said fuel nozzles, conduit means adapted to communicate said pumps and said valve, valve means in said conduit means for selectively communicating the high or low pressure pump with the fuel metering valve in accordance with the pressure of Ithe high pressure pump, a throttle valve for controlling the quantity of air flow to said cylinders,

control means operatively connected intermediate saidA throttle valve and said metering valve for controllingthe quantity of fuel supplied to said nozzles in accordance with vthe position of said throttle, engine speed responsive means for modifying the actuation of said control means.' to increase the quantity of fuel supplied to said nozzlesI ias engine speed increases, and throttle controlled means forA renderingsaid engine speed resp'onsive'nians inopera-i tive to increase the fuel flow through said metering valve beyond a given engine speed.

16. A charge forming device as set forth in claim l2 in which said control means comprises a rst cam member fixed for rotation with said throttle valve, Ia lever system operatively interconnecting said cam member and said metering valve to increase the flow of fuel through the metering valve as said throttle is moved in an opening direction, said engine speed 'responsive means being connected `to said lever system through a lost motion connection, a second cam means operatively connected to said throttle and adapted to shift said lever system to `a position in which said engine speed responsive means will increase the fuel ow through said metering valve yas said throttle opens beyond a given point, a second lost motion connection between said engine speed responsive means and said lever system and which second lost 4motion connection will for a given throttle position yand engine speed render said speed responsive means inoperative to increase the flow of fuel through the metering valve with further increases in engine speed, and a third cam means means operatively connected to said throttle Valve for varying the engi-ne speed at which said second lost motion connection renders said engine speed responsive means inoperative to modify the fuel ow through said metering valve.

17. A charge forming device as set forth in claim 12 in which said control means comprises a rst cam member fixed for rotation with said throttle valve, a lever system operatively interconnecting said cam member land said metering valve to increase the flow of fuel through the metering valve as said throttle is moved in an opening direction, said engine speed responsive means being connected to said lever system through a lost motion connection, a second cam means operatively connected to said throttle and adapted to shift said lever system to a position in which said engine speed responsive means will increase the fuel flow through said metering valve as said throttle opens beyond a given point, a second lost motion connection between said engine speed responsive means and said lever system and which second lost motion connection will for a given throttle position and engine speed render said speed responsive means inoperative to increase the ow of fuel through the metering valve with further increases in engine speed, a third cam means operatively connected to said throttle valve for varying the engine speed at which said second lost motion connection renders said engine speed responsive means inoperative to modify the fuel flow through said metering valve, and means operatively connected to said lever system for compensating fuel flow for changes in ambient pressure.

18. A charge forming device as set forth in claim 12 in which said control means comprises a yfirst cam member fixed for rotation with said throttle valve, a lever system operatively interconnecting said cam member and said metering valve to increase the ow of fuel through the metering valve as said throttle is moved in an opening direction, said engine speed responsive means being connected to said lever system through a lost motion connection, a second cam means operatively connected to said throttle and adapted to shift said lever system to a position in which said engine speed responsive means will increase the fuel flow through said metering valve as said throttle opens beyond a given point, a second lost motion connection between said engine speed responsive means and said lever system and which second lost motion connection will for a given throttle position land engine speed render said speed responsive means inoperative to increase the flow of fuel through the metering valve with further increases in engine speed, a third cam means operatively connected to said throttle valve for varying the engine speed at which said second lost motion connection renders said engine speed responsive means inoperative to modify the fuel flow through said metering valve, a servo device connected to the lever system, a spring member biasing said servo and lever system in a fuel ilow increasing direction to provide power enrichment, manifold vacuum acting on said servo device and normally biasing said device land lever system in a direction providing more economical use of fuel.

19. A charge forming device for Ian internal combustion engine comprising a source of fuel under pressure, a fuel nozzle for each cylinder of the engine, a valve for supplying a metered quantity of fuel to each of said fuel nozzles, a throttle valve for controlling the quantity of air flow to said cylinders, control means operatively connected intermediate said throttle valve and said metering valve for controlling the quantity of fuel supplied to said nozzles in `accordance with the position of said throttle, engine speed responsive means for modifying the actuation of said control means to increase the quantity of fuel supplied to said nozzles as engine speed increases, and throttle controlled means for rendering said engine speed responsive means inoperative to increase the fuel flow through said metering valve beyond a given engine speed, and ambient pressure responsive means for modifying the operation of said control means to vary the fuel supplied by the metering valve in accordance with variations in barometric pressure.

20. A charge forming device for an internal combustion engine comprising a source of fuel under pressure, a fuel nozzle for each cylinder of the engine, a valve for supplying -a metered quantity of fuel to each of said fuel nozzles, a throttle valve for controlling the quantity of air flow to said cylinders, control means operatively connected intermediate said throttle valve and said metering valve for controlling the quantity of fuel supplied to said nozzles in accordance with the position of said throttle, engine speed responsive means for modifying the actuation of said control means to increase the quantity of fuel supplied to said nozzles as engi-ne speed increases, and throttle controlled means for rendering said engine sp eed responsive means inoperative lto increase the fuel ow through said metering valve beyond a given engine speed, a manifold vacuum actuated servo device operatively connected to the control means and normally positioning said control means to provide a lean fuel-air ratio, and spring means urging said control means to enrich the fuel-air ratio when manifold vacuum drops below -a given value.

References Cited in the file of this patent UNITED STATES PATENTS 2,193,927 Jivkovitch Mar. 19, 1940