US3207140A

US3207140A - Fuel pump

Info

Publication number: US3207140A
Application number: US222576A
Authority: US
Inventors: Vernon D Roosa
Original assignee: HARTFORD MACHINE SCREW CO
Current assignee: HARTFORD MACHINE SCREW CO
Priority date: 1962-09-10
Filing date: 1962-09-10
Publication date: 1965-09-21
Anticipated expiration: 1982-09-21
Also published as: GB1061764A; ES291505A1

Description

V. D. ROOSA Sept. 21, 1965 FUEL PUMP 2 Sheets-Sheet 1 Filed Sept. 10, 1962 INVENTOR.

VERNON D. ROOSA BYM7. Wm M ATTORNEYS Sept. 21, 1965 v. D. ROOSA 3,207,140

FUEL PUMP Filed Sept. 10, 1962 2 Sheets-Sheet 2 W INVENTOR.

VERNON D. ROOSA E m/My, WM 574 ATTORNEYS United States Patent 3,207,140 FUEL PUMP Vernon D. Roosa, Hartford Machine Screw Co., Box 1440, West Hartford, Conn. Filed Sept. 10, 1962, Ser. No. 222,576 20 Claims. (Cl. 123-140) The present invention relates to fuel injection pumps for delivering a uniform and consistent measured charge of fuel to each of the cylinders of an internal combustion engine and more particularly to a novel arrangement for varying the rate of fuel delivery by the pump to obtain the desired engine speed and for automatically maintaining a substantially constant relationship between the timing of the injection of the fuel into the several cylinders of the engine and the engine speed throughout the life of the fuel pump.

An object of this invention is to provide a fuel pump incorporating an improved adjustable speed governor having no mechanical flyweights.

Another object of this invention is to provide an improved fuel injection pump incorporating means for adjustably controlling the fueloutput of the pump of the associated engine and is adapted to provide an accurate control of speed for a given speed setting over a long period of time without the need for maintenance or adjustment.

A further object of this invention is to provide a fuel injection pump having a hydraulically controlled metering valve which is easily and simply adjusted to provide the desired engine speed. Included within this object is the provision of means for providing a hydraulic pressure signal which is substantially constant for a given pump speed throughout the life of the pump regardless of Wear of the parts thereof which generate the signal.

A still further object of this invention is the provision of a fuel injection pump incorporating improved means for maintaining a substantially constant relationship between the timing of the injection of fuel into the several cylinders of the engine and the speed of the engine throughout the life of the pump.

Still another object of this invention is to provide a fuel injection pump incorporating an improved remote throttle control mechanism which is insensitive to vibrations and to relative movement between the associated engine and the operator for the throttle.

Other objects will be in part obvious and in part pointed out more in detail hereinafter.

The invention accordingly consists in the features of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereafter set forth and the scope of the application which will be indicated in the appended claims.

In the drawings:

FIG. 1 is a cross-sectional view, partly broken away, of a fuel pump embodying the present invention;

FIG. 2 is an enlarged left end view of the fuel pump of FIG. 1 with the end plate thereof removed;

FIG. 3 is a still further enlarged fragmentary crosssectional view taken along lines 3-3 of FIG. 2;

FIG. 4 is an enlarged cross-sectional view of the fuel pump in FIG. 1 taken along the lines 4-4 of FIG. 1;

FIG. 5 is an enlarged fragmentary cross-sectional View taken along the lines 5-5 of FIG. 1;

FIG. 6 is an enlarged fragmentary cross-sectional view of the metering valve of the fuel pump of FIG. 1;

FIG. 7 is a fragmentary sectional view taken along line 7-7 of FIG. 6;

FIG. 8 is a fragmentary sectional view similar to FIG. 6 showing a modified form of the metering valve of this invention; and

FIG. 9 is another fragmentary sectional view similar 3 ,207,140 Patented Sept. 21, 1965 to FIG. 8 showing still another modified form of the metering valve of this invention.

Referring to FIG. 1 of the drawing, there is shown an exemplary fuel pump having a generally cylindrical pump casing or stator 10 having a relatively large axial opening or bore 12. The left end of the casing, as viewed in FIG. 1, is provided with an enlarged counterbore 22 which is closed by an end plate 24 fastened to the end of the pump casing 10 by any suitable means such as the threaded engagement shown at 26. End plate 24 is provided with a tapered end portion which is sealed to the pump casing 10 by an O ring 28. The right end of the casing 10, as viewed in FIG. 1, is also provided with an enlarged counterbore 30' which is closed by an end plate 32 which engages the end of the bore 30 with a rabbet fit as indicated at 34, and is sealed thereto by O ring 36. End plate 32 may be secured to the casing 10 by any suitable means (not shown).

Disposed within the central bore 12 and rotatably mounted therein is a cylindrical fuel distributing rotor 40 having a fuel pickup or transfer pump 42 on one end thereof and a charge or injection pump 44 on the other end thereof. Fixed to one end of the fuel distributing rotor 40 is a splined coupling 46 for connection to a shaft 48 which may be driven by the engine with which the fuel pump is associated. Shaft 48 is provided with annular grooves 50 which are sealed to end plate 32 by annular sealing members 52.

A fuel inlet to the transfer pump 42 is supplied through the fitting 58 which is connected to a supply of fuel, not shown, and communicates with the transfer pump by a passageway 60 disposed in the casing 10 as indicated by the arrows. The transfer pump increases the pressure on the fuel in proportion to the speed of the rotor and discharges it into passageway 62 which communicates with an annular channel 66 surrounding the fuel distributing rotor 40. A spring-biased pressure regulating valve, generally indicated at 68, is interposed between annular channel 66 and the inlet 60 of the transfer pump 42 to regulate the outlet pressure of the fuel being discharged by the transfer pump to provide a pressure-speed curve of the desired characteristics for the particular application.

The fuel flows from annular channel 66 to longitudinal passageway 64, into radial passageway 72, past a metering valve generally indicated at 76, and into passageways 74 and 75 which communicate with an annular groove 78 provided in the bore 12. Annular groove 78 is axially aligned with inlet port 80 of the fuel distributing rotor.40 so as to continuously communicate with the annular passage 78 as the fuel distributing member is rotated. Inlet port 80 communicates with axial rotor passageway 86 to deliver fuel to charge pump 44.

High pressure fuel discharged from charge pump 44 enters axial passageways 88 and 90 which terminate in ports on the cylindrical surface of the fuel distributing rotor 40. These ports lie in the same radial plane in bore 12 as the ports of the diagonal passageways 92 of the casing 10 which are positioned about the periphery of the bore 12 to communicate in sequence with the outlet ports of the passageway 90 of the fuel distributing rotor 40 as the rotor is rotated. Each of the diagonal passageways 92 are respectively connected to the several cylinders (not shown) of the engine to which fuel is being pumped by means of axial passageways 95 and external tubes 97. While only one diagonal passageway 92 is shown in FIG. 1, it will be apparent that one such pas sageway will be provided for each cylinder of the associated engine and the respective ports thereof are uniformly spaced about the bore 12 so as to be in registry with ports of passageways 90 as the rotor is rotated in timed relation with the engine.

. movement.

In the illustrated embodiment, the transverse rotor passageway 90 is shown as having two discharge ports positioned at diametrically opposed points on the periphery of the fuel distributing rotor 40. It will be apparent that the use of these two ports will result in communication between the passageway 90 and each of the outlet passageways 92 twice during each revolution of the fuel distributing rotor 40. Thus, it is only necessary to rotate the fuel distributing rotor 40 at one-half the speed required if only one such port were utilized.

A nipple 108 is provided for the installation of a hand priming pump (not shown) which is used to provide fuel for injection into the cylinders of the associated engine during the starting of the engine.

In order to provide a unidirectional flow of the inlet fuel to the charge pump, there is provided a check valve 110. As shown, the check valve 110 comprises a ball which is mounted in the rotor 40 to engage a tapered valve seat 112. In axial alignment with the valve seat is a threaded opening 114 which is adapted to receive an adjustable stop screw 116. The amount of longitudinal movement of the ball 110 with respect to valve seat 112 may be varied by adjusting the clearance of the stop screw 116 and the ball 110.

The stop screw 116 may be locked in place by placing a quantity of initially fiowable, settable material 118, such as an epoxy resin, in the threaded opening. After using a sec-nd screw 120 as a hydraulic press to force the resin in between the threads of stop screw 116, the resin 118 thus positioned in the threads sets, or is treated so as to cause it to set, to lock the stop screw 116 in place.

As indicated above, the transfer pump 42 is positioned on one end of the fuel distributing rotor 40. Referring specifically to FIGS. 2 and 3, the transfer pump 42 has a solid cylindrical hub 130 having a pair of radial slots 132 in which are slidably positioned a pair of pump vanes 134. An eccentric liner 136 surrounds the hub 130 and is nonrotatably secured in counterbore 22 by a pin 138 which is positioned in an axial slot 140. Each of the pump vanes 134 is segmented laterally to provide two segments 134a and 13412. The adjacent edges of each pair of segments 134a and 134b are provided with aligned bores 142 in which a coil spring 144 is positioned to urge the segments apart and into engagement with the inner peripheral wall of eccentric liner 136.

Referring especially to FIG. 1, it will be observed that the cylindrical hub 130 of the transfer pump is larger in diameter than the bore 12. It will further be observed that the enlarged hub 130 is provided with a generally radially disposed annular shoulder 146 which is adapted to engage a mating annular wall 148 formed by the bottom of counterbore 22. It will be apparent that these mating annular shoulders form a close-running seal to separate the outlet port 62 and the annular channel 66 from the interior of transfer pump 42.

As previously stated, a charge pump 44 is provided on the right end of fuel distributing rotor 40, as viewed in FIG. 1. As shown, the charge pump comprises an enlarged cylindrical carrier 82 positioned around the end of fuel distributing rotor 40 and secured and indexed thereto by a lock screw 41. The charge pump is provided with a pair of radial passages 84 forming cylinders in which a pair of pistons 94 are positioned for radial Cylinders 84 are aligned to communicate with passageway 86 which in turn discharges high pressure fuel into rotor passageway 88.

Pistons 94 are actuated inwardly as the fuel distributing rotor 40 is rotated in timed relation with the associated engine and the actuation of the pistons is eifected by means of an annular cam 96 through intermediate rollers 98 which are positioned in roller shoes 100. As best hhown in FIG. 4, shoes 100 are slidably mounted in radial slots 102 in the carrier 82 and the cam 96 is seated in the annular recess provided by counterbore 30 and is so constructed and arranged that the pair of pistons 94 and the associated rollers 98 and shoes move inwardly and outwardly simultaneously.

Referring now to FIGS. 4 and 5, there is shown an arrangement for changing the timing of the injection of fuel into the several cylinders of the engine by the charge pump 44. It will be abserved that pressure in the chamher 154 will urge the piston 156 to the right, as viewed in FIG. 4, against the bias of the spring 158. By properly selecting the spring rate of spring 158, the desired amount of advance in the timing of the injection of fuel may be obtained. The chamber 154, as shown in FIG. 4, communicates with the passage 64 through the passageway 152. Thus, the hydraulic force exerted on the piston 156 is proportional to the pressure in the passageway 64, which, as previously stated, is determined by the outlet pressure of transfer pump 42.

A spring-biased ball check valve 162 is positioned in passageway 152 to serve as a hydraulic lock to prevent reverse flow of fuel as a result of the repetitive impulses of torque tending to rotate cam 96 in counterbore 30 as the rollers 98 are urged inwardly by the cam lobes of cam 96. A slight clearance is provided between piston 156 and the walls of chamber 154 to provide a controlled passage of the fuel out of chamber 154 so that the timing of the injection will be retarded as the pressure in chamber 64 decreases.

As indicated above, the metering valve 76 is provided to regulate the effective size of the metering orifice of the pump. Referring particularly to FIG. 6, the metering valve comprises a sleeve having a shank 164 which is slidably positioned in passageway 72. The sleeve is apertured as indicated at 166 and is provided with an enlarged head 178 which is axially slidable in an enlarged portion of the passageway 72. Disposed in the annular cavity surrounding the shank 164 is a pressure regulating spring 168 which engages the lower surface of the head 178 to urge the metering valve 76 in a direction to increase the size of the metering orifice 180. A bleed port 182 communicates between the annular cavity provided by the enlarged portion of passageway 72 and the fuel inlet port 60.

Threaded into the end of passageway 72 is an apertured nipple 184, the threaded end 186 of which engages head 178 of sleeve valve 76 to limit the maximum effective size of the metering orifice 180.

It will be observed that the aperture of the nipple 184 provides a sealed chamber 188 in which a second compression spring 190 is positioned with one end engaging head 178 of the metering valve and the other end engaging an axially movable washer 192 which is sealed with respect to the wall of the nipple 184 to prevent the leakage of fuel. An axially movable throttle control rod 194, which may be depressed in any desired manner, is provided to move the washer axially within the chamber 188 to modify the biasing force of spring 190 for purposes hereinafter more fully described.

An operating piston 193 engages the aperture of movable washer 192, as best shown in FIG. 6, and is provided with a tapered surface which is engaged by the spherical end of the control rod 194 so as to be self-aligning. Surrounding the upper end of control rod 194 (as shown in FIG. 6) is a threaded apertured guide member 195. It will be readily apparent that the axial position of apertured guide member 195 may be adjusted to limit the maximum downward position of sleeve valve 76 to provide a maximum speed adjustment for the fuel pump.

The spring 190 is selected to have a spring rate which is the same or less than the spring rate of spring 168. Thus, when the control rod 194 is depressed to compress.

spring 190, the regulating spring 168 will continue tohold the metering valve 76 in an open position. It will be understood that if the spring 190 is completely depressed so as to be, in effect, a solid column, the control rod 194 may then be depressed to urge the metering valve 76 inwardly to completely close the metering valve to stop the engine.

Alternatively, and as shown, the control rod 194 may have fixed thereto an external stop member 196. It will be apparent that when the control rod 194 is depressed a sufiicient distance, stop member 196 will engage an apertured fitting 198 which is threadedly engaged over the end of nipple 184. It will be readily apparent that by regulating the axial position of the apertured fitting or nut 198 on nipple 184, the maximum amount which the control rod 194 can be depressed may be fixed to provide an idle adjustment for the engine. The apertured fitting 198 may be fixed in its adjusted position by a threaded lock nut 200. A second longitudinal stop, or snap ring 202, may be provided on control rod 194 to limit the downward movement of the control rod so as to prevent it from becoming disassembled from the metering valve.

Where the metering valve control rod 194 is provided with an idling adjustment stop 196, as best shown in FIG. 6, it is necessary to provide a separate positive shutoff for shutting ofi the supply of fuel to the engine. In the illustrated embodiment such a shutoff is provided at the intersection of passageways 74 and 75 between the metering orifice 180 and the charge pump 44. As best shown in FIG. 7, the positive shutoff comprises an axially slidable valve 206, which may be longitudinally actuated by any suitable means, in a passageway 204. As shown in FIG. 7, the slidable valve 206 is positioned so that passageway 74 communicates with passageway 75. It will be readily apparent, however, that when valve 206 is moved to the right (as shown in FIG. 7), it will interrupt the flow of fuel from passageway 74 to 75 and hence provide a positive shutoff for the fuel pump regardless of the position of metering valve 76.

In operation, the transfer pump 42 rotates at a speed proportional to engine speed and increases the pressure of the fuel as engine speed increases. The spring-biased pressure regulating valve 68 modifies the outlet pressure of the fuel from the transfer pump 42 to pressurize the fuel in passageway 64 according to the pressure-speed; curve required by the engine with which the fuel pump is associated.

As will be observed in FIG. 6, the pressure of the fuel in passageway 64 is transmitted into the chamber 188 through aperture 166 to exert a pressure on the head 178 of the metering valve 76. The force resulting from this pressure is in a direction opposite to that of the regulating spring 168 and thus tends to close the metering orifice 180. As the fuel pressure increases due to increased engine speed, the hydraulic and spring forces acting on the metering valve reach a condition of equilibrium and constant speed operation of the engine is achieved. If the speed of the engine should increase or decrease, the pressure of the fuel in passageway 64 will likewise change and the metering valve will assume a new equilibrium position to change the amount of fuel provided to the engine so that the preselected engine speed is resumed.

As best shown in FIG. 6, a restriction 167 may be provided in the passageway 166 to throttle the passage of fuel therethrough to achieve a sensitive regulation of the metering valve 76 without hunting due to pressure surges.

It will be apparent that by changing the axial position of control rod 194, the amount of spring force exerted by spring 190 in a direction in opposition to the force exerted on the metering valve 76 by regulating spring 168 will vary the amount of pressure required to move the metering valve 76 to a position of equilibrium. Thus, in effect, the spring 190 serves to modify the effective spring force of regulatingspring 168 without the movement of the surface on which spring 168 rests.

Referring now particularly to FIG. 8 in which a modified form of the metering valve is illustrated, there is added .a spring-biased check valve 208 which is positioned in the passageway 182 between the annular chamher and the low pressure fuel inlet port 60. Since the fuel pressure in chamber 188 and in passageway 72 is greater than the pressure in chamber 165, and the metering valve is arranged so as to move freely axially in response to the hydraulic and spring forces imposed thereon, some fuel will pass into chamber 165 between the metering valve 76 and the walls of passageway 72 and also from chamber 188 past the head of the metering valve 178. Accordingly, it will be apparent that by regulating the spring force on valve 208, the effective force of regulating spring 168 may be modified.

Referring now to FIG. 9, there is shown another modification of this invention in which a remote throttle control mechanism, which is insensitive to vibrations and to relative movement between the engine with which the injection pump is associated and the operating mechanism for the throttle, is provided. In this modified form of the invention, the passageway 182, as shown in FIG. 6, is plugged or eliminated and a passageway 182a, communicating with chamber 165, is provided. As shown, passageway 182a communicates through an external tube 210 and connects with an external hydraulic control unit 212. The hydraulic control unit 212 is provided with an internal cavity 214 in which is positioned a spring-biased valve 216. Discharge tubing 218 provides communication between cavity 214 of the hydraulic control unit 212 and the low pressure fuel inlet port 60. An axially slidable control rod 220 engages the free end of the spring 222 which biases the valve 216 and is sealed with respect to the hydraulic control unit 212. It will be readily apparent that by controlling the axial position of control rod 220 by any suitable means (not shown) the hydraulic pressure in chamber 165 may be controlled or varied as desired to modify the effective force of regulating spring 168 to control the fuel passing the metering valve, and, hence, the speed of the associated engine.

It will be readily apparent that with the modification of FIG. 9 the axially movable washer 192 of the metering valve may be positioned in a fixed position in which a slight biasing force is produced by spring to provide a low-speed adjustment when control rod 226 is in its downward position since the speed of the engine may be controlled entirely by changing the hydraulic pressure in chamber 165 by the axial position of control rod 220 to change the biasing of spring 222. Moreover, to provide a maximum speed adjustment, an adjustable, collar 223 may be provided on control rod 220 to limit the force exerted by spring 222.

Since the hydraulic control unit 212 may be remotely mounted, say, in the cab of the vehicle incorporating the fuel pump without the use of mechanical throttle linkages to the engine, it is readily apparent that the modification of FIG. 9 provides a hydraulic throttle control for a fuel injection pump which is insensitive to vibrations and relative movement of the engine on which the associated fuel pump is mounted.

As previously discussed, the regulated outlet pressure of the transfer pump 42 controls not only the metering valve 76 but also the hydraulic advance mechanism 150 of the pump. However, it will also be apparent that the metering valve 76 is also controlled by the compression of the adjusting spring 190. Thus, it will be apparent that the relationship of the metering valve and the advance mechanism may be changed in the event of a change in the pressure in the passageway 64 as, for example, due to the result of the wear of the vanes 134 of the transfer pump. It is, therefore, important that means be provided to prevent any substantial change in the pressure in the passageway 64 during the life of the pump. As previously stated, and as best shown in FIG. 3, the vanes 134 are segmented and are spring-biased outwardly to compensate, particularly at low speeds, for any shortening due to wear of the ends of the vanes. Slots 132 communicate with channel 66 to permit transfer pump output pressure to pass from channel 66 into the space between the segments 134a and 1341) of each vane to provide a hydraulic force to assist, particularly at high speeds, in holding the vanes against the eccentric surface of the liner 136. In this manner, the pressure in passageway 64 is maintained at substantially a constant value for any given speed throughout the life of the pump.

From the foregoing, it will be apparent that this invention provides a fuel pump having a novel arrangement for regulating its output and for adjusting the rate of output to different levels and, in addition, incorporates an arrangement whereby the operation of the fuel metering valve and the injection timing advance mechanism are co-ordinated throughout the life of the ump. Finally, the use of spring and hydraulically biased vanes in the fuel transfer pump reduces the viscosity sensitivity of the pump and assures that the output of the transfer pump will be sufiicient at low speeds to provide sufficient fuel pressure for low speed operation.

As will be apparent to persons skilled in the art, various modification and adaptations of the structure above described will become readily apparent without departure from the spirit and scope of the invention, the scope of which is defined in the appended claims.

I claim:

ll. In a fuel injection system for internal combustion engines of the type comprising a charge pump driven by the engine and supplying fuel to the engine and a transfer pump driven by the engine for supplying fuel to the charge pump, a fuel metering valve disposed between the charge and transfer pumps for varying the amount of fuel delivered to the charge pump and thereby controlling the speed of the engine comprising a body having a passageway communicating with the transfer pump and a metering outlet port communicating with the charge pump, a valve member movable in said passageway for increasing and decreasing the effective size of the metering outlet port dependent upon the position of the valve member, the valve member being apertured from end to end and having an outer surface subjected to the pressure of fuel in the passageway tending to move the valve member so as to decrease the effective size of the metering outlet port, a first spring opposing movement of the valve member in response to said pressure and a second spring acting in opposition to the first spring for modifying the spring force acting on the valve member.

2. For use in a fuel injection system for internal combustion engines of the type having a charge pump driven by the engine and supplying fuel to the engine and a transfer pump driven by the engine for supplying fuel to the charge pump, a fuel metering valve disposed between the charge and transfer pumps for varying the amount of fuel delivered to the charge pump and thereby controlling the speed of the engine comprising a body having a passageway communicating with the transfer pump and a metering outlet port communicating with the charge pump, a valve member movable in said passageway for increasing and decreasing the effective size of the metering outlet port dependent upon the position of the valve member, the valve member being apertured and having a surface subjected to the pressure of fuel in the passageway tending to move the valve member so as to decrease the effective size of the metering outlet port, a first spring opposing movement of the valve member in response to said pressure, a second spring acting on the valve member in opposition to first spring and means for adjusting the spring force of said second spring for modifying the spring force acting on the Valve member.

3. In a fuel injection system for an internal combustion engine of the type comprising a charge pump driven by the engine and supplying fuel to the engine and a transfer pump driven by the engine for supplying fuel to the charge pump, a fuel metering valve disposed between the charge and transfer pumps for varying the amount of fuel delivered to the charge pump and thereby controlling the speed of the engine comprising a body having a passageway communicating with the transfer pump and a metering outlet port communicating with the charge pump, a valve member movable in said passageway outwardly of said metering outlet port for increasing and decreasing the effective size of the metering outlet port dependent upon the position of the valve member, the valve member being apertured and having an outer surface subjected to the pressure of fuel in the passageway tending to move the valve member so as to decrease the effective size of the metering outlet port, a first spring opposing movement of the valve member in response to said pressure, a second spring acting on the valve member in opposition to the first spring for modifying the spring force acting on the valve member.

4. In a fuel injection system for an internal combustion engine of the type comprising a charge pump driven by the engine and supplying fuel to the engine and a transfer pump driven by the engine for supplying fuel to the charge pump, a fuel metering valve disposed between the charge and transfer pumps for varying the amount of fuel delivered to the charge pump and thereby controlling the speed of the engine comprising a body having a passageway communicating with the transfer pump and a metering outlet port in one side of the passageway communicating with the charge pump, a valve member movable endwise in said passageway for increasing and decreasing the effective size of the metering outlet port dependent upon the position of the valve member, the valve member being apertured and having a surface subjected to the pressure of fuel in the passageway tending to move the valve member so as to decrease the effective size of the metering outlet port, a first spring opposing movement of the valve member in response to said pressure, a second spring acting on the valve memher in opposition to the first spring and means for compressing said second spring to adjust the differential spring force acting on the valve member, said transfer pump comprising a hub positioned in an eccentric recess, said hub having a radial slot therein for slidably receiving a pumping vane, said pumping vane being laterally segmented, and means for biasing said segments apart to compensate for vane wear.

5. For use in a fuel injection system for an internal combustion engine of the type having a charge pump driven by the engine and supplying fuel to the engine and a transfer pump driven by the engine for supplying fuel to the charge pump, a fuel metering valve disposed between the charge and transfer pumps for varying the amount of fuel delivered to the charge pump and thereby controlling the speed of the engine comprising a body having a passageway communicating with the transfer pump and a metering outlet port in one side of the passageway communicating with the charge pump, a valve member movable endwise in said passageway for increasing and decreasing the effective size of the metering outlet port dependent upon the position of the valve member, the valve member having a shank portion and an enlarged head, the passageway having an enlarged portion to slidably receive the head of the valve member and to provide an annular cavity about the shank thereof, the valve member further being apertured to subject the end surface of the head to the pressure of fuel in the passageway to tend to move the valve member in a direction so as to decrease the effective size of the metering outlet port, a first spring positioned in the annular cavity opposing movement of the valve in response to said pressure and a second spring acting on the valve member in opposition to said first spring to provide an adjustable biasing force to assist thepressure in urging the valve member in a direction to decrease the effective size of the metering outlet port.

6. In a fuel injection system for an internal combustion engine ofthe type comprising a charge pump driven by the engine for injecting discrete charges of fuel into the several cylinders of the engine in timed relation therewith and a transfer pump driven by the engine for supplying fuel to the charge pump at a pressure which increases with increased engine speed, a fuel metering valve disposed between the charge and transfer pumps for varying the amount of fuel delivered to the charge pump in response to the outlet pressure of the transfer pump, and means responsive to the outlet pressure of the transfer pump to advance the time of injection of fuel by the charge pump into each of the several cylinders of the engine, said transfer pump comprising a hub positioned in an eccentric recess, said hub having a radial slot therein for slidably receiving a pumping vane, said pumping vane being laterally segmented, and means for biasing said segments apart to compensate for vane wear and to maintain a substantially uniform transfer pump outlet pressure for a given engine speed throughout the life of the pump.

7. in a fuel injection system for an internal combustion engine of the type comprising a charge pump driven by the engine for injecting discrete charges of fuel into the several cylinders of the engine in timed relation therewith and a transfer pump driven by the engine for supplying fuel to the charge pump at a pressure which increases with increased engine speed, a fuel metering valve disposed between the charge and transfer pumps for varying the amount of fuel delivered to the charge pump in response to the outlet pressure of the transfer pump, and means responsive to the outlet pressure of the transfer pump to advance the time of injection of fuel by the charge pump into each of the several cyinders of the engine, said transfer pump comprising an annular hub positioned within an eccentric recess and having radial slots therein for slidably receiving pumping vanes, each of said vanes being laterally segmented, and a spring for biasing the two segments of each vane apart whereby the ends of the blades are urged toward the wall of the eccentric recess thereby to compensate for vane wear during use and to maintain a substantially uniform outlet pressure for the transfer pump at any given speed throughout the life of the pum 8. In a fuel injection system for an internal combustion engine of the type comprising a charge pump driven by the engine for injecting discrete charges of fuel into the several cylinders of the engine in timed relation therewith and a transfer pump driven by the engine for supplying fuel to the charge pump at a pressure which increases with increased engine speed, a fuel metering valve disposed between the charge and transfer pumps for varying the amount of fuel delivered to the charge pump in response to the outlet pressure of the trans-fer pump, and means responsive to the outlet pressure of the transfer pump to advance the time of injection said transfer pump comprising a cylindrical hub positioned within an eccentric recess and having a radial slot therein for slidably receiving a pumping vane, said pumping vane being laterally segmented, the adjacent sides of the segments of each vane having aligned recesses for receiving a spring for biasing the segments apart toward the wall of said eccentric recess, and means for communicating outlet pressure from said transfer pump to the space between the segments to assist the spring in urging the segments outwardly to compensate for vane wear occurring during use and to maintain a substantially uniform transfer pump outlet pressure for a given engine speed throughout the life of the pump.

9. In a fuel injection system for an internal combustion engine of the type comprising a charge pump driven by the engine for injecting discrete charges of fuel into the several cylinders of the engine in timed relation therewith and a transfer pump driven by the engine for supplying fuel to the charge pump at a pressure increase with increased engine speed, a fuel metering valve disposed between the charge and transfer pumps for varying the amount of fuel delivered to the charge pump and thereby controlling the speed of the engine comprising a body having a passageway communicating with the out let of the transfer pump and a metering port communicating with the inlet of the charge pump, a valve member movable in said passageway for increasing and decreasing the effective size of the metering port dependent upon the position of the valve member, the valve member having a surface subjected to the pressure of fuel in the passageway tending to move the valve member so as to decrease the effective size of the metering port, a spring opposing the movement of the valve member in response to said pressure, means communicating with said passageway for advancing the relative time at which the charge pump injects the charges of fuel into each of several cylinders of the engine, and means for compensating for wear in said transfer pump to maintain a substantially uniform outlet transfer pump pressure for a given engine speed throughout the life of the pump.

110. In a fuel injection system for internal combustion engines of the type comprising a charge pump driven by the engine and supplying fuel to the engine and a trans-fer pump driven by the engine for supplying fuel to the charge pump, a fuel metering valve disposed between the charge and transfer pumps for varying the amount of fuel delivered to the charge pump and thereby controlling the speed of the engine comprising a body having a passageway communicating with the transfer pump and a metering outlet port communicating with the charge pump, a valve member movable in said passageway for increasing and decreasing the effective size of the metering outlet port dependent upon the positon of the valve mem her, the valve member being apertured and having a surface subjected to the pressure of fuel in the passageway tending to move the valve member so as to decrease the effective size of the metering outlet port, a first spring opposing movement of the valve member in response to said pressure and means acting in opposition to the first spring for modifying the spring force acting on the valve member.

11. 'In a fuel injection system for an internal combustion engine of the type comprising a charge pump driven by the engine and supplying fuel to the engine and a transfer pump driven by the engine for supplying fuel to the charge pump, a 'fuel metering valve disposed between the charge and trans-fer pumps for varying the amount of fuel delivered to the charge pump and thereby controlling the speed of the engine comprising a body having a passageway communicating with the transfer pump and a metering outlet port communicating with the charge pump, a valve member movable in said passageway for increasing and decreasing the efiective size of the metering outlet port dependent upon the position of the valve member, the valve member being apertured and having a surface subjected to the pressure of fuel in the passageway tending to move the valve member so as to decrease the effective size of the metering outlet port, a first spring opposing movement of the valve member in response to said pressure, a second spring acting on the valve member in opposition to the first spring for modifying the spring force acting on the valve member, said valve member having a second surface subjected to a variable hydraulic pressure acting so as to assist said first spring member to modify the biasing force acting on said valve member.

12. In a fuel injection system for an internal combustion engine of the type comprising a charge pump driven by the engine and supplying fuel to the engine and a transfer pump driven by the engine for supplying fuel to the charge pump, a fuel metering valve disposed between the charge and transfer pumps for varying the amount of fuel delivered to the charge pump and thereby controlling the speed of the engine comprising a body having a passageway communicating with the transfer pump and a metering outlet port in one side of the passageway communicating with the charge pump, a valve member movable endwise in said passageway for increasing and decreasing the effective size of the metering outlet port dependent upon the position of the valve member, the valve member being apertured and having a surface subjected to the pressure of fuel in the passageway tending to move the valve member so as to decrease the effective size of the metering outlet port, a first spring positioned in an annular recess surrounding said valve member and acting on a surface thereof in a direction to oppose the movement of the valve member in response to said pressure, a drain communicating with said annular recess for draining any fuel leaking past said valve member into said annular recess, and adjustable means for closing said drain to modify the pressure in said annular recess, a second spring acting on said valve member in opposition to said first spring, and means for compressing said second spring to adjust the differential spring force acting on said valve member.

13. In a fuel injection system for an internal combustion engine of the type comprising a charge pump driven by the engine and supplying fuel to the engine and a transfer pump driven by the engine for supplying fuel to the charge pump, a fuel metering valve disposed between the charge and transfer pumps for varying the amount of fuel delivered to the charge pump and thereby controlling the speed of the engine comprising a body having a passageway communicating with the transfer pump and a metering outlet port in one side of the passageway communicating with the charge pump, a valve member movable endwise in said passageway for increasing and decreasing the effective size of the metering outlet port dependent upon the position of the valve member, the valve member being apertured and having a surface subjected to the pressure of fuel in the passageway tending to move the valve member so as to decrease the effective size of the metering outlet port, a first spring positioned in an annular recess surrounding said valve member and acting on a surface of the valve member in a direction to oppose the movement of the valve member in response to said pressure and means for modifying the effective spring force of said first spring comprising a second spring acting on said valve member in opposition to said first spring and a drain communicating with said annular recess for discharging the fuel leaking past said valve member into said annular recess, said drain being provided with an outlet valve for controlling the pressure in said annular recess, and means for adjusting the effective spring force modifying means.

14. For use in a fuel injection system for internal combustion engines of the type having a charge pump driven by the engine and supplying fuel to the engine and a transfer pump driven by the engine for supplying fuel to the charge pump, a fuel metering valve disposed between the charge and transfer pumps for varying the amount of fuel delivered to the charge pump and thereby controlling the speed of the engine comprising a body having a passageway communicating with the transfer pump and a metering outlet port communicating with the charge pump, a valve member movable in said passageway for increasing and decreasing the effective size of the metering outlet port dependent upon the position of the valve member, the valve member being apertured and having a surface subjected to the pressure of fuel in the passageway tending to move the valve member so as to decrease the effective size of the metering outlet port, a first spring opposing movement of the valve member in response to said pressure, and means providing a restriction in the aperture of said valve member to dampen the speed of movement of said valve member in the event of a sudden change of fuel pressure acting thereon.

15. In a fuel. injection system for internal combustion engines of the type comprising a charge pump driven by the engine and supplying fuel to the engine and a transfer pump driven by the engine for supplying fuel to the charge pump, a fuel metering valve disposed between the charge and transfer pumps for varying the amount of fuel delivered to the charge pump and thereby controlling the speed of the engine comprising a body having a passageway communicating with the transfer pump and a metering outlet port communicating with the charge pump, a valve member movable in said passageway for increasing and decreasing the effective size of the metering outlet port dependent upon the position of the valve member, the valve member being apertured and having a surface subjected to the pressure of fuel in the passageway tending to move the valve member so as to decrease the eifective size of the metering outlet port, a first spring opposing movement of the valve member in response to said pressure, a second spring acting in opposition to the first spring for modifying the spring force acting on the valve member, and means in the passageway between the valve member and the charge pump for shuttting off the flow of fuel therebetween.

16. In a fuel injection system for internal combustion engines of the type comprising a charge pump driven by the engine and supplying fuel-to the engine and a transfer pump driven by the engine for supplying fuel to the charge pump, a fuel metering valve disposed between the charge and transfer pumps for varying the amount of fuel delivered to the charge pump and thereby controlling the speed of the engine comprising a body having a passageway communicating with the transfer pump and a metering outlet port communicating with the charge pump, a valve member movable in said passageway for increasing and decreasing the effective size of the metering outlet port dependent upon the position of the valve member, the valve member being apertured and having a surface subjected to the pressure of fuel in the passageway tending to move the valve member so as to decrease the effective size of the metering outlet port, a first spring opposing movement of the valve member in response to said pressure, a second spring acting in opposition to the first spring for modifying the spring force acting on the valve member, and a transverse passageway intersecting the passageway providing communication between the transfer pump and the charge pump and an axially movable sleeve valve therein, said sleeve valve being effective to stop the flow of fuel to the charge pump when it is positioned at the intersection of said passageways.

17. In a fuel injection system for an internal combustion engine of the type comprising a charge pump driven by the engine and supplying fuel to the engine and a transfer pump driven by the engine for supplying fuel to the charge pump, a fuel metering valve disposed between the charge and transfer pumps for varing the amount of fuel delivered to the charge pump and thereby controlling the speed of the engine comprising a body having a passageway communicatiing with the transfer pump and a metering outlet port communicating with the charge pump, a valve member movable in said passageway for increasing and decreasing the effective size of the metering outlet port dependent upon the position of the valve member, the valve member being apertured and having a surface subjected to the pressure of fuel in the passageway tending to move the valve member so as to decrease the effective size of the metering outlet port, a first spring opposing movement of the valve member in response to said pressure, a second spring acting on the valve member in opposition to the first spring for modifying the spring force acting on the valve member, means for compressing said second spring to adjust the differential spring force acting on the valve member and adjustable limit means for setting the minimum spring force of said second spring thereby to provide an idle adjustment.

18. In a fuel injection system for internal combustion engines of the type comprising a charge pump driven by the engine and supplying fuel to the engine and a transfer pump driven by the engine for supplying fuel to the charge pump, a fuel metering valve disposed between the charge and transfer pumps for varying the amount of fuel delivered to the charge pump and thereby controlling the speed of the engine comprising a body having a passageway communicating with the transfer pump and a metering outlet port communicating with the charge pump, a valve member movable in said passageway for increasing and decreasing the effective size of the metering outlet port dependent upon the position of the valve member, the valve member being apertured and having a first surface subjected to the pressure of fuel in the passageway tending to move the valve member so as to decrease the effective size of the metering outlet port, a first spring opposing movement of the valve member in response to said pressure and means actiing in opposition to the first spring for modifying the spring force acting on the valve member, said means including a remotely positioned hydraulic control unit communicating with said valve member, and being constructed and arranged to provide a variable hydraulic pressure acting on a second surface of said valve member so as to tend to move the valve member in a direction to increase the effective size of the metering outlet port.

19. In a fuel injection system for internal combustion engines of the type comprising a charge pump driven by the engine and supplying fuel to the engine and a transfer pump driven by the engine for supplying fuel to the charge pump, a fuel metering valve disposed between the charge and transfer pumps for varying the amount of fuel delivered to the charge pump and thereby controlling the speed of the engine comprising a body having a passageway communicating with the transfer pump and a metering outlet port communicating with the charge pump, a valve member movable in said passageway for increasing and decreasing the effective size of the metering outlet port dependent upon the position of the valve member, the valve member being apertured and having a first surface subject to the pressure of fuel in the passageway tending to move the valve member so as to decrease the effective size of the metering outlet port and a second surface providing an end for a chamber of variable length surrounding the shank of the valve member, a first spring positioned in the chamber surrounding the shank of the valve member and providing a force opposing movement of the valve member in response to said pressure, a second spring acting in opposition to said first spring for modifying the effective spring force acting on said valve member, and a remotely positioned hydraulic control unit communicating with said chamber surrounding the shank of said valve member including spring biased means for modifying the pressure in said chamber whereby the pressure on the fuel leaking past said valve member into said chamber may be regulated by said remote control unit for controlling the effective size of the metering outlet port.

20. In a fuel injection system for internal combustion engines of the type comprising a charge pump driven by the engine and supplying fuel to the engine and a transfer pump driven by the the engine for supplying fuel to the charge pump, a fuel metering valve disposed between the charge and transfer pumps for varying the amount of fuel delivered to the charge pump and thereby controlling the speed of the engine comprising a body having a passageway communicating with the transfer pump and a metering outlet port communicating with the charge pump, a valve member movable in said passageway for increasing and decreasing the effective size of the metering outlet port dependent upon the position of the valve member, the valve member being apertured and having a surface subjected to the pressure of fuel in the passageway tending to move the valve member so as to decrease the effective size of the metering outlet port, a first spring opposing movement of the valve member in response to said pressure, a second spring acting in opposition to the first spring for modifying the spring force acting on the valve member, and means providing a restriction in the aperture of said valve member to dampen the speed of movement of said valve member in the event of a sudden change of fuel pressure acting thereon.

References Cited by the Examiner UNITED STATES PATENTS 2,222,919 11/40 Trapp 123-139 2,877,754 3/59 Roosa l23l39 2,883,934 4/59 Roosa 1035 OTHER REFERENCES C.A.V., German application No. 1,100,382, printed February 23, 1961.

The Oil Engine and Gas Turbine, December 1958, pages 292, 293 and 294.

RICHARD B. WILKINSON, Primary Examiner.

Claims

1. IN A FUEL INJECTION SYSTEM FOR INTERNAL COMBUSTION ENGINES OF THE TYPES COMPRISING A CHANGE PUMP DRIVEN BY THE ENGINE AND SUPPLYING FUEL TO THE ENGINE AND A TRANSFER PUMP DRIVEN BY THE ENGINE FOR SUPPLYING FUEL TO THE CHANGE PUMP, A FUEL METERING VALVE DISPOSED BETWEEN THE CHANGE AND TRANSFER PUMPS FOR VARYING THE AMOUNT OF FUEL DELIVERED TO THE CHARGE PUMP AND THEREBY CONTROLLING THE SPEED OF THE ENGINE COMPRISING A BODY HAVING A PASSAGEWARY COMMUNICATING WITH THE TRANSFER PUMP AND A METERING OUTLET PORT COMMUNICATING WITH THE CHARGE PUMP, A VALVE MEMBER MOVABLE IN SAID PASSAGEWAY FOR INCREASING AND DECREASING THE EFFECTIVE SIZE OF THE METERING OUTLET PORT DEPENDENT UPON THE POSITION OF THE VALVE MEMBER, THE VALVE MEMBER BEING APERTURED FROM END TO END AND HAVING AN OUTER SURFACE SUBJECTED TO THE PRESSURE OF FUEL IN THE PASSAGEWAY TENDING TO MOVE THE VALVE MEMBER SO AS TO DECREASE THE EFFECTIVE SIZE OF THE METERING OUTLET PORT, A FIRST SPRING OPPOSING MOVEMENT OF THE VALVE MEMBER IN RESPONSE TO SAID PRESSURE AND A SECOND SPRING ACTING IN OPPOSITION TO THE FIRST SPRING FOR MODIFYING THE SPRING FORCE ACTING ON THE VALVE MEMBER.