US2446497A

US2446497A - Fuel injection apparatus

Info

Publication number: US2446497A
Application number: US500329A
Authority: US
Inventors: Alden P Thomas
Original assignee: Timken Roller Bearing Co
Current assignee: Timken Co
Priority date: 1943-08-28
Filing date: 1943-08-28
Publication date: 1948-08-03
Anticipated expiration: 1965-08-03

Description

A118- 3, 1948- A. P. THOMAS 2,446,497

FUEL INJECTION APPARATUS Filed Aug. 28, 1945 5 Sheets-Sheet 1 Aug. 3, 1948. A. P. THOMAS FUEL INJECTION APPARATUS 5 Sheets-Sheet 2 Filed Aug. 28, 1945 WN. NN

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Aug- 3, 1943- A. P. THOMAS 2,446,497

FUEL INJECTION APPARATUS Filed Aug. 2B, 1945 5 Sheets-Sheet 3 5 sheets-sheet 4 Aug. 3, 1948. A. P. THOMAS FUEL INJECTION APPARATUS Filed Aug. 2s, 194s Aug. 3, 1948. i A. P. THOMAS 2,446,497

FUEL INJECTION APPARATUS Filed Aug. 28, 1943 5 Sheets-Sheet 5 Patented Aug. 3, 1948 UNITED STATES PATENT OFFICE Timken Roller Company, Canton.

h10, a corporation of Ohio Application August 2.8, 1943. Serial No. 500.329

claims. (0l. 123-140 This invention relates principally to fuel in- .lection apparatus for multi-cylinder compression ignition engines. and more particularly to fuel in- Jection apparatus of the common rail type Wherein a pump delivers fuel under pressure to an accumulator or pressure chamber common to all cylinders of the engine and the fuel is directed from said chamber to the engine cylinders in proper sequence by a distributing valve operating in synchronism with the engine.

The principal objects of the present invention are to provide a simple and economical fuel injection apparatus of the above type that will deliver a correct quantity of fuel to the proper engine cylinder at the proper time and at the proper rate for efficient combustion: that will provide manual and/or automatic control over the quantity and/or timing of the fuel injection according to working conditions and requirements: that will maintain a constant or variable pressure in the accumulator chamber; that will prevent drib ble of the fuel from the injection nozzles at the termination of the injection: and that will dampen or smooth out pressure fluctuations or surging of the fuel in the accumulator chamber or reservoir due to the pressure impulses of the fuel pump. The invention consists in the fuel injection apparatus and in the construction. combinations and arrangements of parts hereinafter described and claimed.

In the accompanying drawings. which form part of this specification and wherein like symbols refer to like parts wherever they occur,

Fig. 1 is an end elevational view of one end oi' a fuel injection apparatus embodying my invention,

Fig. 2 is an end elevation of the opposite end of said apparatus,

Fig. 3 is a central vertical longitudinal sectional view through said apparatus on the line I-l in Fig. l.

Figs. 4, 5, 6, 'L B. 9 and 10 are vertical crosssectional views on the line #-4, I-l. l-I. 1 1. l-I. O-l. and il-Il. respectively. in Fis. 3.

Figs. li and 12 are horizontal cross-sectional views on the lines Ii-I I and i2-I2. respectively. in Fig. 3. V

Fig. 13 is a central vertical longitudinal sectional view through a modiiied form of fuel injection apparatus.

Fig. 14 is a vertical cross-sectional view on the line lt--Il in Fig. 13,

Fig. 15 is an enlarged fragmentary vertical longitudinal sectional view through the modified fuel injection apparatus in the region of the pressure regulating valve,

Fig. 16 is a horizontal cross-sectional view on the line Il-Il in Fig. i5,

Figs. 17 and 18 are vertical cross-sectional views on the lines Il-il and iI--Il. respectively, in Fig. 13,

Fig. 19 is a fragmentary horizontal section on the line Il-Il in Fig. 18,

Fig, 20 is a. vertical cross-sectional view on the line II-ll in Fig. 13,

Fig. 21 is a fragmentary longitudinal sectional view showing a distributing valve with a metering notch of modified form,

Fig. 22 is a fragmentary vertical sectional view showing a further. modification of the distributing valve; and

Fig. 23 is a central vertical longitudinal section through a modified form of distributor. showing the pressure regulating valve mounted in the outer end of thedistributor valve.

The fuel injection apparatus shown in Pigs. 1 to 12, inclusive. of the accompanying drawings. comprises any suitable fuel pump A and a fuel distributor B for directing fuel received from said pump to the dierent cylinders of a multi-cylinder internal combustion engine (not shown) The fuel pump A illustrated in the drawings is a high pressure. double-plunger type pump comprising a housing made up of a main or lower section l and an upper section 2 seated on and detachably secured to the top of said main section. The main housing section I of the pump has a chamber I at one end thereof and a horizontal bore 4 leading from said chamber to the opposite end of said section.

Each of the pump units oi' the double-plunger fuel pump A preferably comprises a tappet cup l reciprocable ln a vertical bore 6 that leads downwardly through the top of the main section i of the pump housing and opens into the horizontal bore l therein. Each tappet cup t is actuated preferably by means of a double-lobed cam 1 formed on a cam shaft l that extends through the horizontal bore l and is rotatably supported therein adjacent to the ends thereof by means of suitable anti-friction bearings 9. The two doublelobed cams 1 are disposed in out-of-phase relation; and the cam shaft l is adapted to be driven from its outer end by the multi-cylinder internal combustion engine that is to be supplied with fuel by the present fuel injection apparatus. The pump plungers Il. however, need not operate in timed relation to the firing cycle of the engine cylinders.

The upper housing section 2 of the pump A has two downwardly opening bores lli therein that register with the respective tappet cup receiving bores of the lower housing section of said pump. Mounted in each of the bores N of the upper housing section 2 is a cylindrical barrel Il which is held in said bore against axial movement therein between a shoulder I2 at the upper end thereof and a sleeve nut I2 which surrounds said barrel and is threaded into the lower end of said bore beneath an external annular shoulder il on said barrel. Reciprocable in each of the pump barrels Il is a pump plunger or piston Il whose lower end is urged downwardly into engagement with the bottom of the tappet cup i therebelow by means of a coil compression spring It that surrounds said plunger. The spring il seats against the underside of the pump barrel retaining sleeve nut Il and its lower end rests on a spring seat member l1 which is held in the lower end of the pump plunger Il by means of a snap ring is that seats in a groove provided therefor in said plunger. By this arrangement. the upward or pressure stroke is imparted to the pump plunger i through the tappet cup I by the double-lobed cam I on the cam shaft l and the return or suction stroke is imparted to the plunger by means of the coil spring Il which serves to hold said pump plunger in contact with the bottom of said tappet cup and the latter in engagement with said cam.

The pump barrels or cylinders ii have radially disposed inlet ports il therein near the upper ends thereof, which ports are uncovered in the lowermost positions of the plungers I5 and are covered during the upward travel or delivery strokes thereof. The upper pump housing section 2 has an inlet chamber 2l formed therein common to the inlet ports or both pump barrels l I. The fuel inlet chamber 2l is supplied with fuel from a suitable supply tank (not shown) through a suitable fuel supply pipe or conduit 2| that opens into said chamber through the end of the upper pump housing section 2. Both pump cylinders i I open at their upper ends into a common high pressure chamber 22 formed in the upper pump housing section 2; and communication between the upper end of each of said pump barrels and said high pressure chamber is controlled by a one-way discharge valve comprising a disk or other suitable valve 22 which is Yieldably held seated on the upper end of said pump barrel by means of a coil compression spring 2l interposed between the upper end of said chamber and the upper face of the disk valve.

By the arrangement described, the two pump plungers are reciprocated in out-of-phase relation by the cam shaft l, fuel being drawn on the down or suction strokes of the plungers I5 from the fuel inlet or supply chamber 2li through the radial inlet ports Il of the pump barrels into the space therein between the working ends of said plungers and the undersides of the discharge valves 22 and then forced into the high pressure chamber 22 when the plungers cover said radial inlet ports and develop suillcient pressure to lift said discharge valves oil' their seats.

The high pressure chamber 22 of the fuel pump unit A communicates through a conduit or passageway 2l with the fuel distributor unit B which directs the fuel received from said chamber to the engine cylinders in proper timed relation to the ring cycle thereof. This fuel distributor unit preferably comprises a body or housing 26 that is secured to the end of the main v charge passageways section I of the pump housing remote from the pump plunger end thereof and has a horiaontal bore 21 therethrough that opens into the chamher 2 and is disposed in axial alinement with the cam shaft l. The high pressure fuel conduit 2i opens into the horizontal bore 21 of the fuel distributor housing 26 through a radial bore or passageway 2l therein; and said housing has a plurality of radially disposed fuel delivery or dis- 22, one for each engine cylinder, that lead from said horizontal bore inwardly of the passageway 2l and communicate with the respective engine cylinders through fuel injection lines or conduits III that terminate in fuel injection nozzles (not shown) preferably of the normally closed hydraulically opened type. As shown in Fig. 3, the horizontal bore 21 of the distributor housing 26 opens at its outer end into a low pressure return chamber 2| and a fuel return pipe or conduit 22 leads from said chamber to the fuel supply tank.- Direct communication may be established between the low pressure chamber 2| and the high pressure inlet passageway 28 of thedistributor unit B through a bypass passageway 22 that extends from said high pressure fuel inlet passageway to said low pressure chamber. 'I'he by-pass passageway II has a cylindrical pressure regulating valve 24 reciprocable therein that is yieldably held in closed position by a coil compression spring 2i that seats at one end against the outer end wall of the low pressure chamber 2| and at the other end against the adjacent end of said valve. The pressure regulating valve Il has an axial bore Il that leads from the high pressure passageway end thereof and terminates at its other end in a series ofradial ports Ila adapted, when the valve 24 is moved axially against the pressure of the valve spring II by the pressure in the high pressure passageway 28. to open into the low pressure chamber 2| and thus establish direct communication between said passageway and chamber.

Mounted in the bore 21 of the valve casing or housing 2l of the distributor B for rotary movement with an axial sliding movement relative to the cam shaft l is a cylindrical distributing valve 21 for directing fuel from the high pressure passageway 28 to the discharge conduits 2li in proper sequence and in proper timed relation to the tiring cycle of the engine. The axially shiftable rotary distributor valve 21 has two annular grooves 2l and I! formed therein that are spaced apart longitudinally thereof, the outermost annular groove 38 communicating with the high pressure fuel inlet port 28 of the distributor in all axially adjusted positions oi' said valve, The innermost annular groove 28 of the distributor valve is in continuous communication with the low pressure chamber 2| through a T-bore or passageway Il in the distributor valve 31, the inner end of this passageway opening into said annular groove and the outer end of said passageway opening into said low pressure chamber through the outer end face of said valve.

Formed in the peripheral surface of the distributor valve 31 between the

annular grooves

22 and 29 is a fuel metering notch or recess 4I that extends rearwardly from the rear end of the outermost annular groove 2l and terminates short of the innermost annular groove 2l and is adapted to be brought into successive register with the fuel injection or discharge ports 29 of the distributor during the rotary movement of said valve. As shown in the drawings. the metering notch Il is disposed at an oblique angle to the rotary axis of the distributor valve 31 and is o! substantially V-shape: that is. the notch is of gradually increasing width from its blind or inner end to the point where it opens into the inner end of the annular groove 33. The length of the outermost annular groove '3l in the distributor valve 31 is such that said groove is in communication with the high pressure inlet port 23 whenever any portion of the metering notch 4| is in position to register with the fuel injection or discharge ports. By this arrangement, the quantity of fuel passing from the high pressure inlet port 23 to the delivery ports 29 through the` annular groove 3l and the V-shaped metering notch Il may be varied according to the width of the portion of the notch opposite said discharge ports. Thus, the duration and quantity of the fuel discharge are a maximum when the wide end of the tapered metering notch in the distributor valve 31 is opposite the discharge ports 29 and are a minimum when the small end of said notch is opposite said discharge ports, and the fuel discharge is shut off completely when said distributor valve is shifted outwardly far enough so that said notch does not touch said discharge ports. As shown in Fig. 3 ofthe drawings, the metering notch 4l has its leading and trailing edges disposed at oblique angles to the rotary axis of the distributor valve 31, thereby providing an earlier start and end of fuel injection when the wide end of the obliquely disposed notch is opposite the fuel metering or discharge ports 28 than when the narrow end of said notch is opposite said ports.

For high speed engines, the distributor valve 31 may be provided between the annular grooves 3l and 39 with an oblique pressure relief groove 43. As shown in Fig. 3, the pressure relief groove is located adjacent to and substantially parallel with the trailing edge of the metering notch ll and extends from the innermost annular groove 39 to a point Just short of the outermost annular groove 3l. The oblique groove or channel 43 follows the metering notch Il and, by coming into communication with the nozzle or discharge ports 23 immediately after said metering notch has cleared the same. operates to relieve the pressure in the injection lines by connecting them with the low pressure chamber 3| through the annular groove 38 and the T-bore III, thus preventing pressure surges in said injection lines and nozzle dribble and secondary combustion resulting therefrom.

The distributing valve or rotor 31 extends into the chamber 3 in the distributor supporting end portion of the tubular housing section i of the pump A in axial alinement with the cam shaft B, which also extends into said chamber and ls operatively connected to said distributing valve to drive the same. Thus, in the arrangement illustrated, the pump A drives the distributing valve 31 and must necessarily be timed in place with the engine. However, the pump may be driven out of phase with the engine when not used as the driving means for the distributor valve. For some types of engines the driving connection between the cam shaft 3 and the distributor valve 31 may comprise governors C and D for automatically controlling the quantity and time, respectively, of the fuel injection in accordance with the speed of the engine, both governors being enclosed within the chamber 3. which is adapted to contain oil for lubricating the gov ernor parts and has a breather opening Il and a suitable filter cap Il therefor.

The fuel metering governor C cnprises a thrust cup Il fixed to the inner end of the distributing valve 3l and having an axially slidable driving connection with a member I1 driven from. the cam shaft I. The thrust cup Il is keyed to the reduced inner end portion of the distributing valve 31 between a thrust washer a and a retaining ring "b, said thrust washer abutting against the shoulder formed by said reduced end portions of said valve. The axially slidable drivlng connection between the member 41 and the thrust cup II comprises a series of circumferentially spaced outwardly inclined fingers or wings Il on one end of the hub of the thrust cup Il and a series of similarly spaced radially disposed grooves lll that are formed in the opposing end face of the driving member 4l and are adapted to snugly receive at their outer ends the outer ends of the respective fingers or wings on said thrust cup. Mounted in the radial grooves u in an enlarged end portion iii of the driving member I1 in position to engage the opposing faces of the inclined fingers I8 of the thrust member or cup Il are fly weights in the form of governor balls ll that are adapted to move outwardly in said grooves due to centrifugal force when the speed of the engine driven cam shaft l increases and thus shift said thrust cup and the distributor valve 31 rigid ther'ewith axially in the direction that will bring the narrower portion of the metering slot 4| opposite the metering ports 33 and thereby reduce the quantity of fuel delivery.

As shown in Fig. 3, the distributor valve il is normally urged in the direction of increased fuel and the fingers I of the thrust member 4B held in contact with the governor balls Il in the radial grooves Il in the enlarged end of the member Il by means of a coil compression spring $3 that is sleeved on a supporting link 53a between two washer or spring seat members 53h also sleeved on said linkl said spring supporting link being located in the chamber 3 above the inner end of the distributor valve 3l. The spring supporting link 63a has a slot-and-pln connection 53e at one end with the free outer end of an internal throttle arm 54 and the other end of said link is pivotally connected. as at 53d, to the upper arm of a yoke lever 55, said throttle arm and yoke lever being mounted in the chamber 3 on shafts i8 and 51, respectively, for swinging movement longitudinally of the distributor valve and cam shaft axes. The two spring seat members 53h are held seated against the free ends of the throttle arm Sl and the upper yoke lever arm 55, respectively, by the pressure of the spring 53. The yoke lever 56 has a depending yoke arm 58 having pins 53a that project into an annular groove 53 formed by washers sleeved on the hub of the thrust cap I between an annular shoulder thereon and' the thrust washer 46a, whereby the governor spring Il tends to shift the distributor valve 31 in the direction of increased fuel feed, while the gover nor balls 5I are adapted to operate against the pressure of said governor spring to shift said distributor valve in the direction of decreased fuel feed when the speed of the engine driven cam shaft I increases. The throttle shaft 56 extends outside the chamber 3 where it is provided with a throttle lever Ill, the adjustment of which varies the compressive pressure of the free end of the throttle arm 5I on the spring 53 and the position of the yoke lever 55, thus holding the distributor andas? valve I1 in the position required to hold the engine at the speed determined by the position of said throttle lever regardless of the load applied to the engine. The maximum fuel feed position of the distributor valve l1 is determined by an adjustable stop in the form of a screw Il that is threaded through the outer end wall of the chamber 3 in position to be engaged by the upper arm of the yoke lever 55 and is provided with a lock nut l2 for securing said screw in the proper position of adjustment. The above governor is primarily an industrial type governor, which automatically maintains any constant engine speed selected by the operator regardless of the load applied. The governor could, however. be used for automotive purposes due to the fact that the pressure of the spring 5I on the throttle lever Il will not prevent automotive accelerator pedal pressure operation thereof.

The device D for varying the moment of commencement of the fuel injection comprises two weights Il arranged one on each side of the cam shaft B and each pivotally secured at one end by means of a pivot pin I5 to a driving member that is keyed or otherwise rigidly secured to said cam shaft for rotation therewith, whereby said weights are adapted for swinging movement towards and away from each other transverse to the cam shaft in response to the speed thereof. The free end of each weight B4 is pivotally connected by means of a pivot pin I1 to one end of a link Il whose opposite end is connected by means of a pivot il! to the enlarged governor ball receiving end portion of the member 41 for driving the thrust cup 46 of the fuel feed quantity control governor C. As shown in the drawingsl the thrust cup driving member l1 has a hub portion 'III mounted for rotary but nonaxial sliding movement on the cam shaft I; and the links I8. which form the driving connection between the centrifugal governor weights Il and the member 41. are disposed between said weights and the radial wall of said member. Outward swinging movement of each governor weight Bl is yieldably resisted by means of a coil compression spring 1I, which is mounted in a pocket 12 provided therefor in the outer peripheral surface of said weight between the

pivots

66 and 81 with its outer end seating against the inner peripheral surface of an outer peripheral flange 'il on the driving member 88. By this arrangement, the drive is transmitted from the cam shaft 8 to the member l1 for driving the thrust cup 46 through the governor weights 64 and links 88 and, as said weights move outwardly due to centrifugal force when the speed of the cam shaft increases, or inwardly with decreasing speed, the phase relationship between the cam shaft and the distributor valve Il is altered so that the amount of injection is advanced as the cam shaft speed rises and is retarded when the speed of the cam shaft is reduced.

The hereinbefore described fuel injection apparatus operates as follows: Fuel is drawn from the supply tank (not shown) into the inlet chamber of the pump A through the fuel supply or conduit 2i by the suction stroke of the high pressure pump piungers i5. These plungers 'may operate in phase or out of phase and they need not operate in timed relation with the engine. In the present arrangement, however. the cam shaft I drives the distributor valve Il and must necessarily operate ln unison with the engine so that the metering notch Il of said valve will register with the discharge or injection ports 29 of the fuel the engine cylinders.

During the pressure stroke of the pump plunger: Il. the fuel is forced under high pressure through the one-way discharge valves I8 into the high pressure outlet chamber 22 of the pump. said outlet chamber, together with the inlet passageway Il of the distributor B and the conduit 2l leading from said outlet chamber to said inlet passageway. constituting a common or single high pressure chamber. The fuel is held under constant pressure in this common high pressure chamber Il, Il, 2l by means of the pressure regulating valve t4 in the distributor. this valve being lifted off its seat to permit flow of surplus fuel into the low pressure chamber Il and thence through the conduit I2 to the supply tank when the fuel in said high pressure chamber reaches a predetermined maximum pressure, whereby the rate of fuel flow from said high pressure chamber to the engine cylinders remains the same at all engine speeds. The valve I4 also acts as a piston to smooth out pressure fluctuations created by the high speed plunger pump A. The distributing valve Il is rotated by the engine driven cam shaft l of the high pressure pump A and thus operates in proper timed relation to the firing cycle of the engine. During the rotation of the distributor valve Il. the metering notch li thereof is brought into successive register with the injection ports Il leading to the different engine cylinders through the fuel injection lines lil. the fuel from the constant high pressure chamber Il, 2B, 2l reaching these lines through the annular space provided by the outermost annular groove Il in said distributor valve. said metering notch Il and said injection ports.

The quantity of fuel permitted to enter the fuel discharge lines lil depends upon the width of that portion of the V-shaped metering notch Il presented to the discharge ports 20, the effective width of said notch being varied by axially adjusting said valve, which adjustment is controlled by the governor C which operates in response to the speed of the engine so that the distributing valve is moved axially to supply more or less fuel per injection as required for proper operation of the engine. When the distributing valve 31 is shifted axially far enough to move `the small end of the metering notch 4i clear of the ports 2l, no injection can take place and the engine will stop. At the same time, the timing of the moment of the fuel injection may be varied in accordance with the speed of the engine by means of the timing governor D which operates to change the phase relationship between the engine driven cam shaft Il and the distributing valve ll driven thereby in accordance with the speed of the engine. The shape and inclination of the leading and trailing edges of the metering notch Il may be varied to give a fixed or variable start or ending of the injection for engines having different injection requirements.

The transfer channel or pressure relief groove 4l in the distributing valve I1 is in communication at all times with the low pressure chamber 3l through the T-bore I0 in said valve. Thus, the transfer groove or channel Il, by coming into register with the fuel injection ports 2! immediately after the metering notch 4l clears said ports, operates to release the pressure in the fuel injection lines I0 after each fuel injection and thus prevents pressure surges in the injection lines and the secondary nozzle discharge or dribble which results in secondary combustion.

As above pointed out. the pressure regulating valve 34 operates to maintain a constant pressure in the high pressure chamber 22, 2l. 28, whereby the injection pressure and the rate oi' flow through the high pressure lines 30 to the injection nozzles will remain the same at all engine speeds. As pointed out above. the fue] quantity control governor C is primarily of the industrial type which operates to maintain any constant engine speed selected by the operator regardless of the load applied. 'I'he governor C may, however, also be used as an automotive governor. due to the fact that the pull of the governor spring 53 on the throttle lever Bil is not suilicient to adversely effect ordinary accelerator pedal pressure thereon.

The modified form of fuel injection apparatus shown in Figs. i3 to 20, inclusive, includes a double-plunger high pressure fuel pump AI, like the pump A, and also the chamber 3 formed in the lower or main pump housing section I. The fuel distributor Bi of the modified construction comprises a body or housing 28a which is secured to the end wall of the chamber 3 and has a fuel inlet passegeway or port 28a that opens into a horizontal bore 21a in said body and is adapted to be supplied with fuel from the discharge chamber 22a of the pump A through the conduit 25a, the inlet passageway or port 28a, the pump chamber 22 and the connecting conduit 25 constituting a common high pressure chamber. The distributor body 26a has a plurality of circumferentially spaced fuel delivery or discharge ports or passageways 29a that lead from the bore 21a outwardly of the inlet port 28a and communicate through discharge pipes or conduits 30a with the respective cylinders.

The horizontal bore 21a opens at its inner end into the chamber 3 and at its outer end into a low pressure return chamber 3io. A horizontal passageway or bore 33a leads from the high pressure inlet chamber 28a to the low pressure chamber 3io and is provided with' a pressure regulating valve 34a which is held to its seat by a spring 35a when the pump is nonoperative. When the pump starts to operate, high pressure fuel is forced into the high pressure inlet chamber 28a by the high' pressure pump Ai, allowing a certain portion of such high pressure fue] to escape at a lower pressure into the low pressure chamber 3Ia, from whence it is returned as excess fuel to the supply tank (not shown) through the fuel return pipe 32a leading from said low pressure chamber. When the valve 31a is forced ofi' its seat, communleation is established between the high pressure inlet chamber 28a and the low pressure chamber 3io preferably through a restricted passageway in the form of a longitudinal peripheral groove 36a formed in said valve. The passageway 38a is adapted to restrict the iiow of fuel past the valve 34a so that. for small deliveries of high pressure fuel from the high pressure pump AI, a relatively large proportion of fuel will iiow past said valve into the low pressure chamber 3 la, thereby producing a comparatively low pressure in the high pressure chamber 22a, 25a., 28a. As the amount of fuel delivery from the high pressure pump increases with speed, a relatively small proportion of the fuel is by-passed through the restricted passageway 30a, whereby a much higher pressure is built up in the high pressure chamber 22a, 25a. 28a. 'This variable pressure valve Ila alsoacts yas a piston which tends to smooth out pressure fluctuations in the high pressure chamber 22a. Ila, 2li: due to the impulses received from the high pressure pump. As the double-lobed cams 1a of the high pressure pump give four impulses for each revolution of the' cam shaft 8, such impulses will be comparatively easy to smooth out by the high pressure regulating valve lla.

Mounted in the bore 21a or the distributor Bi is a rotary and axially slidabledistributor valve 31a having an annular fuel groove 38a adapted to be brought into register with the high pressure fuel inlet 20a, a fuel metering notch or port Ila opening into the outer end of said annular groove. and a fuel transfer groove or channel 3a adjacent to the trailing edge of said metering notch. The leading edge of the metering notch a is disposed parallel to the axis of rotation of th'e distributing valve so as to provide a fixed start of fuel injection, while the trailing edge of said notch is inclined to provide a variable end of fuel injection as said valve is shifted axially to vary the quantity of fuel delivery.. The transfer channel 43a operates to reduce the pressure in the injection lines 30a after each injection by connecting said lines with the low pressure chamber 3 la. With the form of pressure regulating valve 24a shown iin li'ig.` 13, variable injection pressure is produced, but the amount of fuel delivered by the injection lines 30a for any particular distributor valve position will remain the same regardless of the pump speed. The actual time during which each injection port 28a is in communication with the metering notch I la is greater at lower pump speeds, but th'e pressure will also be lower so that the amount of fuel iiow is the same as for a shorter communication of the metering port and the -injection port with the fuel at a higher pressure.

The modified fuel injection apparatus shown in Fig. 13 is provided with a hydraulic governor CI for adjusting the distributor valve 31a axially to vary the quantity of fuel delivery. This hydraulic governor comprises a control shaft III that is disposed crosswise of the chamber 3 and extends outside thereof where it is provided with a throttle lever Il. Located in the chamber 3 is an internal throttle link 32 having one end fixed `to the control shaft and the other end pivotally secured, as at l2, to one section Il of a telescopic y link. the other section 85 of which is pivotally supported, as at It, on the upper arm o! a yoke lever B1 that is supported for vertical swinging movement lengthwise of the distributor valve axis on a horizontal cross shaft Il located in the chamber 3. Th'e two sections of the telescopic link are connected by a coil tension spring l! that yieldably resists endwise separation of .said sections. The lower or yoke arm Oil of the yoke lever cooperates with a saddle 80a seated in an annular groove 9| provided therefor in a thrust member or sleeve 92 that is fixed to the inner end of the distributor valve 31a, whereby said valve is adapted to be shifted axially in the direction of increased fuel feed by the pull of the tension spring 8l on the upper arm of th'e yoke lever 81. By this arrangement, the distributor valve 3Ia is shifted axially against the tension 0f the spring I9 in the direction of decreased fuel by the varying pressure of the fuel in low pressure return chamber 3 la, the tension of said spring being adjusted for dierent speeds by means of the throttle lever Il. Proper operation of the hydraulic governor Ci requires a restricted passageway in the fuel return line 32a, such passageway preferably comprising a narrow groove 93 in a plug I4 located in said return line. Mounted in a hollow screw 62a in the outer end wall of the chamber l is an adjustable bumper or surge spring ila, which, when engaged by the upper arm of the yoke lever l1, serves to control the idling speed of the engine in all speed settings of the throttle lever Il.

The thrust member or sleeve 82 projects beyond the inner end of the distributor valve Ila and has an axially slidable but non-rotary notchand-tongue connection l! with the adjacent end of a member mounted for rotary but nonaxial sliding movement on the adjacent end of the crank shaft l. The member may constitute one element of a manually operable mechanism DI for altering the relative angular positions of the cam shaft l and the distributor valve 31a to thereby vary the movement of commencement of fuel injection. The member Il has external inclined or helical splines I1 thereon that cooperate with straight internal splines SI in one end of a surrounding axially slidable member BI. The opposite end of this axial slidable member 99 is formed with straight internal splines that cooperate with straight external splines lili on a member |02 that is keyed or otherwise rigidly secured to the cam shaft I for rotation therewith. The internally splined slide member 80 is actuated by a yoke arm In that has its upper end splined or otherwise rigidly secured to a bushing or sleeve IM which surrounds the control shaft Iii and constitutes a bearing therefor and projects outside of the chamber l where it is provided with a manually adjustable timing lever lill. As shown in Figs. 13 and 18, the connection between the yoke arm ill and the slide member Il comprises a saddle member 98a that is straddled by said yoke arm and seats in an annular groove IIb provided therefor in said slide member and has outstanding pins 99e that are received in downwardly opening notches ila provided therefor in the lower ends of the branches of said yoke arm.

The variable pressure type fuel injection apparatus shown in Figs. i3 to 20, inclusive, operates as follows: The fuel is forced by the high pressure pump into the common high pressure chamber 22a, 25a, 28a and the pressure of the fuel in said chamber lifts the pressure regulating valve Ila off its seat, thus allowing a certain portion of the fuel to pass from the high pressure inlet port 28o of the distributor Bi into the low pressure chamber Sia and return through the conduit 32a to the source of fuel supply for the double plunger high pressure pump AI. This surplus or by-passed fuel flows from the high pressure inlet port 20a into the low pressure chamber Bia through the restricted passageway 18a in the pressure regulating valve lla. The cross-sectional area of the restricted by-pass passageway 36a is calculated to so restrict the flow of fuel past the valve a that, for small deliveries of fuel from the high pressure pump, a relatively large quantity of fuel will escape past the valve, while for large deliveries of fuel from said pump a relatively small quantity of fuel will escape past said valve. Thus, the pressure and rate of injection varies with the speed oi the pump Al. The amount of fuel injected, however, remains the same in any particular speed setting of the distributor valve 31a due to the fact that the actual time during which the metering notch lla is in communication with an injection port 29a is longer and the injection pressure is lower at lower pump speeds, while at higher pump speeds, the injection pressure is greater, but the length of time of registering of i2 said metering notch with said injection port is shorter.

During the rotation of the distributor valve 31a, the fuel passes from the inlet port Ila into the annular fuel channel Ila of said valve and thence through the fuel metering slot lia and discharge ports 28a and injection lines Illa to the respective engine cylinders, the quantity of fuel injected depending upon the width of the metering slot presented to the injection ports 29a. During the rotation of the distributor valve the relief groove or channel a comes into communication with the injection ports Ila immediately after the metering slot lia passes such ports, at which time communication is established between the injection ports and the low pressure chamber Ila, thus relieving the pressure in the fuel injection lines lla and thereby preventing pressure surges and nozzle dribble.

The distributing valve IIa is adjusted axially to vary the quantity of fuel delivery by means of the throttle lever Il, which may be set for any desired speed or to cut oif the fuel injection entirely and thus stop the engine. The governoring action is obtained in each speed adjustment of the throttle lever il by means of the variable pressure created in the low pressure chamber lla by the restricted passageway Ila for bjr-passing excess fuel from the high pressure chamber 22a, Ila, 28a to said low pressure chamber and by the restricted passageway $3 in the threaded plug I4 in the fuel return line IIa. In operation. the pressure regulating valve 14a by-passes various amounts of fuel into the low pressure chamber Ila, depending on the amount being pumped to said low pressure chamber by the high pressure pump. As the speed of rotation of the injection pump increases, more fuel will be delivered thereby to the low pressure chamber ila. The pressure regulating valve 34a is so designed that it will allow the pressure. in the high pressure chamber to vary between fixed limits in relation to the speed of rotation of the engine. At low speed a smaller quantity of fuel will be bypassed by the pressure regulating valve than at high speed and larger quantities of fuel will be by-passed into the low pressure chamber at high speed than at low speed. The varying pressure in the low pressure chamber is directly dependent upon the speed of the injection pump, whereby a varying pressure is created in the low pressure chamber Ila tending to force the distributor valve lla axially towards the high pressure pump. This movement of the distributor valve is resisted by the tension spring B9, whose tension is regulated by the throttle lever Il. Thus. for any selected position of the throttle lever Il and a resulting tension on the spring Il. the distributor valve a will tend to assume a position in balance between the pressure from said spring and the pressure in the low pressure chamber l la. For any speed position, when the distributor valve Ila is in balance at some certain speed, should the load on the engine drop, and the speed tend to increase. the pressure in the low pressure chamber I la will immediately increase. said valve will be forced to the right. and the amount of fuel being injected will be cut down, thereby automatically governoring the engine. To change speed, the tension on the spring Il is increased or decreased accord ing to the setting of the throttle lever ll, whereby the distributing valve Ila assumes a new position of balance between the pressure in the chamber Ila and said spring thus slowing down or speeding up the engine as desired. The purpose 13 of the 'throttling passageway 93 in the return pipe 3! leading from the low pressure chamber to the sou'rce of fuel supply is to build up the desired pressure in the low pressure chamber lia.

A phase change in the relation of the distributor valve I'la and the cam shaft l to advance or retard the timing or moment of the commencement of the fuel injection is obtained by manually adjusting the timing control lever lill. peration of this timing lever |05 causes the sleeve member 99 to move axially of the members II and IIII that are coupled together by said sleeve. This coupling member 99, when slid axially of the member 9G brings about a relative angular adjustment of the distributor valve 31a relative to the cam shaft l due to the action of the helical internal splines 91 of said member on the straight external splines 9B on the member 96 that drives said distributor valve.

As stated above, the quantity of fuel delivery depends on the width of the portion of the tapered metering notch that is presented to the discharge ports, While the moment of the beginning and ending of the fuel delivery depends on the angularity and shape of the portions of the leading and trailing edges of said notch that are presented to said ports. Thus, the shape and arrangement of the metering notch may be changed to meet the injection requirements of different types of engines. With the form of metering notch Il shown in Fig. 3, a maximum quantity and an early start and end of fuel delivery is obtained when the wide end of said notch is presented to the discharge ports 29, while a minimum quantity and late start and end of fuel injection is provided when the narrow end of said notch is presented to said discharge ports. A reverse timing of the fuel injection may be obtained by reversing the direction of rotation of the distributing valve 31. The metering notch lla shown in Fig. 13 provides a fixed start and a variable end of fuel injection. The notch Ila will provide a variable start and a fixed end of injection by reversing the direction of rotation of the valve 31a. Fig. 2l shows a distributing valve 31h with a metering notch lib having an inclined edge with portions disposed at different angles, thereby providing a very irregular start or end of fuel injection, depending on the direction of rotation of said valve.

Fig, 22 shows a distributing valve 31e wherein the pressure relief groove "c is formed merely by flattening ofl' one side of said valve, and the metering notch lic has its leading edge flattened or beveled as at lid, so that a restricted passage is provided between the metering notchand the discharge port before the main portion of said notch registers with said port, thereby providing a variable rate of fuel injection, that is, a small quantity of fuel at the start of the fuel injection and an increased quantity at the end thereof. In some instances, it might be desirable to provide the trailing edge of the metering notch with the beveled surface lid, whereby the rate of each injection would decrease towards the end thereof; that is, the injection would start with a large quantity of fuel and the amount of fuel would gradually decrease near the end of each injection.

In the modification shown in Fig. 23, the high pressure fuel inlet port 28h of the distributor opens into the annular fuel groove 38h in the rotary distributor valve 31h and the fuel metering groove IIb thereof leads from said annular groove and successively registers with the fuel discharge ports 29h. The pressure regulating valve Nb is mounted in an axial bore l provided therefor in the outer end of the distributor valve I'Ib, which bore leads from the low pressure chamber lib and opens into the annular fuel groove 38h in said distributor valve through a dlametral bore |01 therein. By this arrangement, when the pump is operating. the valve b is lifted oil its seat by the pressure transmitted thereto from the high pressure inlet port 2lb. annular fuel groove 38h and Vdiametral bore 101, thereby permitting the fuel to be lay-passed from said high pressure inlet port past said pressure regulating valve into the low pressure chamber lib, from which the fuel flows through the restricted passageway 93 in the return pipe 32h to the source of fuel supply. A valve closing spring lib is located in the outer end of the bore |06 in the distributor valve iilb between the pressure regulating valve 34h and a seat lill provided therefor in said bore. This location of the pressure regulating valve may be used with either a mechanical or a hydraulic governor.

Obviously. the hereinbefore described fuel injection apparatus admits of considerable modiflcation without departing from the invention. Therefore, I do not wish to be limited to the precise arrangements shown and described.

What I claim is:

1. In a fuel injection apparatus for a multi-cylinder internal combustion engine, a fuel distributor adapted to communicate with the respective engine cylinders, a pump operable by said engine for supplying fuel to said fuel distributor, a rotary valve for successively placing said distributor in communication with the engine cylinders, said valve being shiftable axially to vary the quantity of fuel supplied to said fuel discharge passageway. a shaft operating in timed relation to the engine, and a driving connection between said shaft and valve comprising means responsive to the speed 0i said shaft for axially shifting said valve and means responsive to the speed of the shaft for changing the phase relationship between said shaft and valve.

2. In a fuel injection apparatus for a multicylinder internal combustion engine. a fuel distributor adapted to communicate with the respective engine cylinders, a pump operable by said engine for supplying fuel to said fuel distributor, a rotary valve for successively placing said distributor in communication with the engine cylinders, said valve being shiftable axially to vary the quantity of fuel supplied to said fuel discharge passageway, a shaft operating in timed relation to the engine, a driving connection between said shaft and valve comprising means responsive to the speed of said shaft for axially shifting said valve in one direction, and means for urging said valve in the other direction including a thrust member on said valve, a lever pivotal on an axis disposed crosswise of the rotary axis of said valve and operatively engaging said thrust member, a pivotally mounted throttle arm, a link connecting said throttle arm and lever, and a coil compression spring mounted on said link in abutting relation to said lever and throttle arm.

3. In a fuel injection apparatus for a multicylinder internal combustion engine, a fuel distributor adapted to communicate with the respective engine cylinders, a. pump operable by said engine for supplying fuel to said fuel distributor, a rotary valve for successively placing said distributor in communication with the engine cylinders, said valve being shiftable axially to vary the quantity of i'uel supplied to said fuel discharge passageways, a shaft axially alined with said valve and operating in timed relation to the engine. and a driving connection between adjacent ends of said shaft and said valve comprising means responsive to the speed of said shaft for axially shifting said valve and means responsive to the speed of said shaft for changing the phase relationship between said shaft and valve, said first mentioned speed responsive means comprising a member journaled on said shaftl a thrust member fixed to said valve and having an axially slidable but non-rotary connection with the member journaled on said shaft, governor balls interposed between said members and adapted to move outwardly under centrifugal force to shift said thrust member and said valve axially in one direction, and a spring for urging said thrust-member in the other direction, said second mentioned speed responsive means comprising a driving member fixed to said shaft, centrifugal weights arranged on opposite sides of said shaft and plvotally secured at one end to said driving member, and a link connected at one end to the other end of each of said weights and at its other end to the member journaled on said shaft.

4. In a fuel injection apparatus for a multivalve comprising means for axially shifting said 4 valve relative thereto and means for changing 16 the phase relationship between the latter and said valve.

5. In a fuel injection apparatus for a multicylinder internal combustion engine. a fuel dis- 5 tributor adapted to communicate with the respective engine cylinders. a multi-cylinder pump for supplying fuel to said fuel distributor, a rotary valve for successively placing said distributor in communication with the engine cylinders, said valve being shiftable axially to ,vary

driving connection between said pump shaft and valve comprising means responsive to the speed of said pump shaft for axially shifting said valve relative thereto and means responsive to the speed of said pump shaft for changing the phase relationship between the latter and said valve.

ALBEN P. THOMAS.

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

UNITED STATES PATENTS Number Name Date 1,311,504 Ford July 29, 1919 1,614,498 Rochefort Jan. 19, 1927 1,825,443 Chormann et al. Sept. 29, 1931 1,893,980 Lang Oct. 25, 1932 2,031,825 Wild et al Feb. 25, 1936 2,165,447 Browne July i1, 1939 2,233,934 Backhouse Mar. 4, 194i FOREIGN PA'I'E'NTS Number Country Date 15,962 England July 10, 1913 404,252 England Jan. 11. 1934 172,164 Switzerland Dec. 17. i934 Certificate of Correction Patent N o. 2,446,497.

August 3, 1948.

ALDEN I. THOMAS It is hereby certified that errors appear in the rinted specification of the above numbered patent requiring correction as follows:

olumn 6, line 61, for cap read cup; column 10, line 26, for iin" read in; line 65, for 31a read 37a; column 16,

line 30, list of references cited, for Jan. l said Letters Patent should be read with th 9, 1927 read Jan. 18, 1.927; and that the ese correctins therein that the same may conform to the record of the case in the Patent Oilice.

Signed and sealed this 2nd day of November, A. D. 1948.

THOMAS F. MURPHY,

Assistant Commissioner of Patents.

to vary the quantity of i'uel supplied to said fuel discharge passageways, a shaft axially alined with said valve and operating in timed relation to the engine. and a driving connection between adjacent ends of said shaft and said valve comprising means responsive to the speed of said shaft for axially shifting said valve and means responsive to the speed of said shaft for changing the phase relationship between said shaft and valve, said first mentioned speed responsive means comprising a member journaled on said shaftl a thrust member fixed to said valve and having an axially slidable but non-rotary connection with the member journaled on said shaft, governor balls interposed between said members and adapted to move outwardly under centrifugal force to shift said thrust member and said valve axially in one direction, and a spring for urging said thrust-member in the other direction, said second mentioned speed responsive means comprising a driving member fixed to said shaft, centrifugal weights arranged on opposite sides of said shaft and plvotally secured at one end to said driving member, and a link connected at one end to the other end of each of said weights and at its other end to the member journaled on said shaft.

ALBEN P. THOMAS.

August 3, 1948.

Signed and sealed this 2nd day of November, A. D. 1948.

THOMAS F. MURPHY,

Assistant Commissioner of Patents.