US2910056A

US2910056A - Fuel injection pump

Info

Publication number: US2910056A
Application number: US612391A
Authority: US
Inventors: Achilles C Sampietro
Original assignee: Thompson Ramo Wooldridge Inc
Current assignee: Northrop Grumman Space and Mission Systems Corp
Priority date: 1956-09-27
Filing date: 1956-09-27
Publication date: 1959-10-27
Anticipated expiration: 1976-10-27

Description

Oct- 27, 1959 A. c. sAMPlETRo FUEL INJECTION PUMP 4 Sheets-Shen 1 Filed Sept. 27, 1956 )MMIV l. 'wink alle.. In.

Y@ we? wyfrf Oct. 27, 1959 A. Q SAMPIETRQ 2,910,056

FUEL INJECTION PUMP Filed sept. 27. 195e 4 sheets-sheet z Of- 27,1959 A. c. sAMPlETRo 2,910,056

FUEL INJECTION PUMP Filed Sept. 27, 1956 4 Sheets-Sheet 3 f Z2-Wai@ Oct. 27, 1959 A Q SAMPlETRQ 2,910,056

FUEL INJECTION PUMP Filed Sept. 27, 1956 4 Sheets-Skaail 4 wam' 72M? il@ United States Patent C) FUEL INJECTION PUlWP Achilles C. Sampietro, Detroit, Mich., assgnor to Thompson Ramo Wooldridge Inc., a corporation of Ohio Application September 27, 1956, Serial No. 612,391

'12 Claims. (Cl. 123-140) The present invention relates -to improvements in fuel injection systems and more specifically to an improved fuel injector with an actuating pump which delivers a metered amount of fluid to control the amount of fuel delivered to the engine.

In internal combustion engines of the fuel injection type, a measured amount of fuel is injected into the cylinder for combustion. Among the factors that will insure successful injection and successful operation of the engine is a complete and thorough atomization of the fuel which requires an extremely high injection pressure. Since the injector has to be in close proximity to the cylinder, these high injection pressures are sometimes diicult to obtain because of operating space limitations that restrict the mechanism used. It is also important that the quantity of fuel injected at these high pressure be accurately controlled and it is desirable that the amounts delivered to each of the cylinders be uniform. Further, the uniformity of fuel delivery for each of the cylinders and high injection pressures must be maintained throughout the life of the engine and the mechanism to attain these objectives must be of such that it does not require frequent replacement to maintain high performance standards.

It is, therefore, an objective of the present invention to avoid the diiculties heretofore encountered with devices previously used and to provide an improved fuel injector and a pump for operating the injector whereby the uid delivered from `the pump operates the injector.

Another object of the invention is to provide an improved fuel injector system wherein accurately timed pressure discharge of the atomized fuel is possible.

Another object is to provide a fuel injection system wherein an accurate metered control of the amount of fuel injected into the engine is achieved and the amount of fuel can be varied over a range with an infinite degree of lcontrol of the amount.

Another object of the invention is to provide a fuel injection system wherein a plurality of injection units are employed and uniform amounts of fuel are delivered to ,the engine by each injector and the injection quantities of the injectors can be uniformly controlled.

` A still further object of the invention is to provide a .fuel injection system whereinl a plurality of injectors are -operated by fluid pressure delivered by a single pump unit.

Another object of the invention is to provide a fuel injection system capable of high pressure atomization of the fuel wherein the high pressures are encountered at the injection zone of the injector unit only.

Yet another object of the invention is to provide a fuel injection arrangement wherein the individual injectors are operated by iluid pressure `and wherein the fuel injected for each injector is a xed faction of the amount of actuating iluid delivered to the injector.

A still further object of the invention is to provide a fuel injector unit wherein an improved high pressure .atomization of fuel is achieved.

f `rltnotlier objectvof the invention is to provide an im- 2,910,056 Patented oct. `27, 1959 proved fuel injector which is operated by lluid pressure and wherein an improved fluid circulation arrangement for both the operating fluid and fuel is utilized.

A further object of the invention is to provide an improved pump capable of delivering metered quantities of fluid which may be used in fuel injection operation and the like. 1

, 4A further object of the invention is to provide an improved pressure pump which is capable of improved more accurate metering of the uid delivered.

Another object of the invention is to provide a uid pump for fuel injection operation or the like which employs a plurality of fluid delivering cylinders and wherein the amount of fluid delivered by the cylinders may be regulated and an accurate and uniform regulation of all the cylinders is obtainable. e v

Another object of the invention is to provide a Viluid injection system wherein the quantity of fuel delivered to the engine can be directly and immediately adjusted there.

Other objects and advantages of the invention will become more apparent with the teaching of the methods and apparatus of the invention as presented in conjunction with the complete disclosure ofthe preferred embodiments described in conection with the specification and claims and the accompanying drawingsLin which:

Figure 1 is a vertical sectional view taken through the injector;

Figure 2 is a vertical sectional view taken through the metering pump;

Figure 3 is a sectional view taken along the line III- III of Figure 2;

Figure 4 is a vertical 'sectional VView taken through a metering pump of a modified form; v

Figure 5 is a horizontal sectional view taken along the line V-V of Figure 4;

Figure 6 is a horizontal sectional view taken along the line VI-VI of Figure 4;

Figure 7 is a sectional view taken along the line VII- VII of Figure 4;

Figure 8 is a sectional view taken along the line VIII- VIII of Figure 4;

Figure 9 is a sectional View taken along the line IX- IX of Figure 4; and

Figures l0 and 10b are schematic illustrations showing the position of the inlet openings to the pump at various stages of operation of the pump and at various settings thereof.

The embodiments illustrated in the drawings show the preferred form of the invention as a fuel injector operated by metered actuating fluid delivered from a pump. It will be understood, however, that although the inventive features find particular advantage and utility in the embodiments shown, they may be adapted and their features utilized in other environments.

F uel injection system The system as a whole includes the fuel injector shown in Figure 1 and the metering pump of the form shown in Figures 2 and 3 or of the form shown in Figures 4 through 10b. The injector itself is mounted on the engine block 12 and has a discharge orifice 14 which injects the fuel in atomized form into the combustion zone. The injector is operated by fluid pressure delivered by the pump, such as that shown in Figure 2. The fluid delivered by the pump is metered and the quantity delivered determines the amount of fuel which will be injected into the combustion area. The tlui-d delivered by the metering pump is much larger in volume than the small amount of fuel injected, and the injector is constructed so that it will always deliver a fixed fraction of the quantity of fluid delivered. Therefore, by accurately determining the amount of uid which is delivered from the pump to the injector, the amount of fuel injected can be accurately controlled. Also the arrangement wherein the fuel injected is a xed fraction of the fluid delivered by the pump obtains a mechanical advantage whereby the pump and the lines carrying the fluid to the injector can measure the fluid out in larger quantities and, therefore, can obtain a high degree of accuracy in quantities injected at the injector with a smaller degree of accuracy in the quantities of fluid pumped. Also, the parts of the pump can be made larger and more durable than if the entire operating system were limited to delivering quantities of the small minute volume required for the injection of the fuel. The amount of fluid delivered from the pump and, hence, the amount of fuel delivered to the combustion zone is varied to obtain the speed of operation of the engine. The quantities are controlled, such as by control rod 16, as shown in association with the pump of Figure 2, to obtain the proper idling, running, acceleration, and top speeds. A mechanism is also provided to insert the factors of ternperature and pressure of the manifold of the engine into the control system as 'will later be described in detail in connection with the description of the preferred embodiments of the pump and the other individual elements of the machine. For convenience of reference, the elements will be described in individual sections, dividing the disclosure into the portions devoted to the injector, the pump of Figures 2 and 3, and the pump of Figures 4 through l0. It will be understood from the description, however, that the various elements operate in cooperation and that although certain features of the invention may be used individually in various environments it is necessary to obtain the coaction of the units as a whole to serve all objectives and purposes.

The fuel injector The injector includes a body portion 18 which is preferably cylindrical in shape and which is mounted in a mating cylindrical opening 20 inthe engine block 12. The body portion 18 of the injector may be mounted in any position, but for purposes of reference it will be referred to as the lower portion of the injector. The lower portion 18 receives an upper body portion 22 which is suitably clamped thereto by means not shown and which contains passageways for the supply of fuel, for the supply of actuating fluid, and for the removal of the actuating uid and fuel which leak past the operating parts. To isolate the various compartments and conduits, gaskets 24 `and 26 are provided which may be annular in form to seal the upper body portion 22 against the lower body portion 18.

The upper body portion has openings to receive threaded pipes, and the opening 28 receives a pipe or line 30 for the supply of actuating fluid from the pump, and the other end of the pipe 30 is shown in Figure 2 threaded into the opening 32 in the pump.

The actuating uid supply line 30 leads to drilled passageways 34 and 36 through the upper injector body 22 to communicate with an annular chamber 38 which is defined between a cylindrical opening in the lower body portion 18 and an annular sleeve 40. The sleeve 40 is a cylinder having an inner wall 42 in which slides the injector plunger 44. An annular groove 46 extends around the outer surface of the sleeveV in communication with the annular chamber 38 and a bored hole 48 leads actuatlng fluid from the annular chamber 38 into the actuation pressure chamber 50 within the cylinder 42. The actuation fluid in the pressure chamber 50 acts on the lower surface 52 of the injection plunger to force it upwardly or to the right as shown in Figure l.

The plunger 44 has a main body portion forming a piston sliding within the cylinder 42. The upper end of the b ody portion is reduced in diameter and a coil oompress1on spring 54 surrounds this end 56- Th@ alga between the end 56 of reduced diameter and the cylinder wall 42 may be termed a leakage chamber 58, since this chamber receives the leakage of actuating fluid from the pressure chamber 50 and the leakage of fuel from the intake chamber 60.

The compression spring 54 bottoms on a shoulder 62 on the upper injector body 22. Coaxially within the shoulder is a bore of smaller diameter which forms the intake chamber 60. The reduced end 56 of the injector plunger 44 slides within the intake chamber 60 and narrows to an end 64 of even smaller diameter and this end is tapered and will enter an opening 66 of smaller bore which communicates between the intake chamber and the intake port 68. The intake port is threaded to receive a supply line which is not shown but which supplies fuel to the small passageway 66 leading to the intake chamber 60.

It will be seen that as the plunger 44 moves upwardly or to the right as is shown n Figure l, the reduced sealing end 64 enters the passageway 66 effectively sealing the intake chamber. This intake chamber is filled with fuel and this fuel has been drawn in on the intake stroke of the plunger 44. When the plunger moves upwardly or to the right as is shown in Figure 1, in its discharge stroke, the intake chamber 60 is sealed and the fuel is compressed and forced through the center of the injection plunger. The plunger contains a central coaxial passageway 70 Iwhich communicates with the intake chamber 60 through several small lateral passageways 72. Fuel passing through the coaxial plunger passageway 70 discharges through a lateral passageway 74 at the injection end of the plunger. This fuel enters the injection chamber 76 and is forced out through the injection or .discharge nozzle 14.

The left end 77 of the plunger 44 is also reduced in size and is slidably mounted in a guide 78 mounted within the body 18. The guide contains a cylindrical opening to slidably receive the reduced discharge end 77, and the guide there forms a divider between the actuating fluid chamber 50 and the injection chamber 76. The reduced end 77 has a conically pointed end 80 which extends into the upper end of the injection nozzle 14 to seal it when the plunger is at the left end of its intake stroke and before starting its discharge stroke.

In the discharge stroke, since the area 52 at the top of the injection plunger is much larger than the area 82 at the reduced end of the injection plunger, the force on the uid can be greatly multiplied in the ratio of the difference of areas from the plunger.

The fluid in the actuation chamber 50 and the fuel in the intake chamber 60 will both be at a relatively high pressure. Although the tolerances of the relative parts are held very close, a small amount of leakage may occur past the sliding surfaces. This leakage flows into the leakage chamber 58 and passes out through the bored passageways 84 and out through the leakage port 86. 'Ihis port is shown threaded for purposes of connecting a lcakage line for receiving both the fuel and actuation flui While only one injector is shown in Figure 1, it will be understood that a plurality of identical or similar injectors are used with an individual injector being pro vided for each cylinder of the engine. Only one pump need be provided, however, as the pump is designed to sequentially deliver metered quantities of actuation fluid at the proper time for injection of fuel into the engine and the pump is designed to meter the amount of uid delivered to each injector in an equal amount.

The fluid metering pump of Figures 2 and 3 The pump, as illustrated in Figures 2 and 3, includes a main body portion which may be formed of a casting with a series of annularly arranged, evenly spaced cylindrical bores, shown at 92 through 106, which form pressure chambers in the casing or housing 90. Within each f the cylindrical chambers is mounted a piston with the pistons being shown at 108 through 122. The casing or housing thus is provided with eight cylindrical chambers, each having a piston slidably mounted therein. Eight chambers are provided in the particular embodiment shown since it will be used with an engine having eight cylinders and provided with eight injector units. It will beunderstood that different numbers of cylinder and chamber arrangements can be used in accordance with the number of pistons provided for the engine or in accordance with the number of injectors to be served. Each of the chambers is provided with a delivery opening, and chamber 92 is shown as provided with a delivery opening 32 while chamber 100 is shown as provided with a delivery opening 124. To these delivery openings are connected pressure lines leading to the individual injectors.

The chambers iill with actuating fluid on the intake stroke of the piston by drawing it through the delivery openings. To supply liuid lost through leakage, individual intake openings are provided as shown at 126 and 128 in Figure 2. The intake openings communicate with an annular groove 27 extending completely around the casing 90 and cut into an annular ring 129 which slides tightly over the cylindrical surface 130 of the casing 90. Actuating fluid is supplied to the annular groove 29 through a conduit 131. A gasket such as an O-ring seal 132 is provided to avoid leakage of actuating fluid from the annular chamber in one direction and an annular gasket 132 may be provided between the heavy flange 134 on the casing and the ring 128 to prevent leakage of actuating fluid in the other direction from the annular chamber 127.

Each of the intake openings is provided with a ball check valve including a ball 136 as is shown in the intake opening 128 held against a small insert having an opening 142 by compression spring 140. The check ball 136 will move away from the opening 142 in the retainer 138 when the piston 108 is moving upwardly in the intake stroke if insuicient fluid is available through the discharge opening. When the piston moves downwardly in the discharge stroke, the ball 136 moves against the opening 142 to seal the chamber and cause the actuating iluid to be formed downwardly through the discharge opening 32. Since the check valves are the same for each of the intake openings, only one need be described.

The controlled quantity of delivery is regulated from each of the piston and chamber assemblies by providing a relief orifice 144 in each of the pistons. This relief orifice 144 communicates with the pressure chamber 100 through a central bore 146 coaxial with the piston. The relief orifice, in combination with the central bore 146, permits a spill-over or escape of oil from the chamber 100 at a predetermined point of the delivery stroke of the piston 146. To accomplish this, the relief orice 144 becomes aligned with a control orifice 148. This control orifice is positioned in a cylindrical sleeve 150 surrounding the piston 116 and permits the piston to slide therethrough. The relief orifice 148 permits the oil to spill up through the piston and to escape into the annular channel 160 cut into the inner surface of the annular flange 162 in the cap 200 which forms the top of the casing, as is shown in Figures 2 and 3. The groove 160 communicates with a uid escape line 164 which is vented or at a low pressure to permit the ready escape of actuating fluid.

The sleeve 158 surrounding the piston 116 is slidably adjustable with respect to the piston. This will, of course, alter the position of the control orifice 148 relative to the relief orifice 144 in the piston. In other words, as the piston moves downwardly into the chamber in its discharge stroke, it will become aligned with the control orifice 148 at a location in its stroke depending upon the setting of the control sleeve 158.

Control sleeves are provided for each of the pistons With the sleeve 158 surrounding the piston 116 and sleeve "6 166 surrounding piston 108. As illustrated by the piston 108, the relief orifice in each of the pistons leads to the annular groove 168 to permit the ready escape of oil when this groove becomes aligned with the control orifice.

The control orifice also has a groove 169 extending around the inner surface of each ofthe sleeves 166.

The control sleeves are uniformly adjusted and simultaneously adjusted for all of the pistons by being attached to a grooved head `170 mounted on a control rod 172. The control sleeves, such as 158 and 166, contain an anuularly extending ange at their top ends and these anges 174 and 176 project into the groove 178 of the head 170. The control rod 172 is slidably mounted in a centrally bored hole located centrally with respect to each of the pistons. The control rod 172 is operated by a control rod extension 182 which is connected to it by an expansible bellows 184. The bellows is located in a sealed chamber 186 which is connected by lines 188 and 190 to members which create a pressure within the chamber 186 in accordance with the temperature and pressure of the manifold of the engine. The chamber housing the bellows 184 is threaded in a sealed manner to be connected to the casing 90 and has a gasket 192 sealing it to the control rod extension 182. The control rod extension carries a lateral cam follower 194 riding in a shaped groove 196 in a cam pivoted at 198. The cam is pivoted by the control rod 16 which will relatively move the groove 196 to slide the follower 194 therein. The position of the groove with respect to the follower will move the control rod extension 182 to position the control rod 172 and hence position the control sleeves such as 116 and 108. The expansible bellows 184 will influence the position of the control rod 172 regardless of the position of the cam slot 196 to thereby subject the position of the control sleeves to the parameters of the temperature and pressure of the manifold.

To the casing is attached a cap 200 secured by bolts such as 202 and 204. The cap carries bearings 206 and 208 rotatably supporting the drive shaft 210 for operating the pump. The pump is operated by moving the pistons in their intake and discharge stroke sequentially and this is achieved by a rotary cam 212 mountedv on the drive shaft 210. The axis 214 of the drive shaft is offset from the axis 216 of the control shaft 172, which marks the center of the casing 90 supporting the pistons, and this will cause the cam 212 to have relative lateral motion as it rotates. The cam actuates the piston by means of balls 218 and 220 mounted in sockets such as 222 in the top end of the pistons. The cam 212 is provided with an annular groove 222 and, since the axis of the cam is offset from the position of the pistons, the balls will work back and forth relative to the groove 222, creating equal Wear as the pistons are actuated. A very small lubricating passageway 224 is extended upwardly from the central bore 146 in each of the pistons to permit the escape of a small amount of actuating fluid for lubrieating the walls. When the pistons are being pushed downwardly in the discharge stroke, the lubricating passageway 224 will be sealed by the pressure on the balls, but when the pistons are released, a small amount of fluid will be permitted to escape. The pistons are returned on their intake stroke by coil compression springs 226 and 228 which bottom on the shoulders formed at the base of each of the cylindrically shaped

pressure chambers

92 and 100. As each piston is returned by its coil compression spring it withdraws the actuating fluid delivered to the individual injector and permits the spring of the injector to return the injector plunger to its normal position. r

Although the operation of the actuation iluid pump shown in Figure 2 and the injector shown in Figure l will be clear from the description of the structure and operation of the individual elements coacting with the other elements of the mechanism, a review of the operation of these devices will be helpful in reviewing the '7 attainments, advantages and objectives of the invention.

Metered amounts of actuating uid are delivered from the pump of Figure 2 by each of the pistons such as 108 and 116. The number of pistons chosen is determined by the number of fuel injectors to be used and, as illustrated in Figure 3, eight pistons are utilized for an eightcylinder engine having a fuel injector for each cylinder. The pistons are each slidably mounted in chambers in the casing 90. The pistons are molded in their intake stroke by coil compression springs such as 226 and 22S. The actuating fluid is returned through the delivery openings 32 and 124. The pistons are moved in their discharge stroke by the rotating operating cam 212 which successfully forces the pistons downwardly in their chambers. Each piston is provided with a relief orifice such as 144 in the piston 116. At a certain point in the delivery stroke of the piston the relief orifice 144 communicates with the control orice 148 to permit the actuating uid to escape from within the chamber 100, thus terminating any further delivery to the delivery opening 124.

The control orifices are adjustable in position by being located in the sleeves shown at 158 and 166. These sleeves are linked to the control rod 172 which is 0perated by the cam slot 196 to control the speed of operation of the engine. The factors of temperature and pressure of the manifold are fed into the control rod by means of the bellows 186.

The metered amounts of actuating uid are delivered to the individual injectors such as shown in Figure l. The pressurized metering fluid enters through the opening 128 to pass in through the pressure chamber 50. This forces the plunger 44 in the discharge direction whereupon the intake chamber will be sealed by the extension 64 of the plunger entering the passageway 66. Further movement of the plunger will force the fuel through the passageway 70 within the discharge plunger. This fuel then passes into the fuel injection chamber 76 to be forced out through the discharge port 14 into the cylinder of the engine.

The plunger 44 is returned by the compression spring 54 which aids in returning the actuating fluid to the pump. Since the intake chamber 60 is considerably smaller than the pressure chamber 50, a magnification of pressure is obtained and the injector delivers a fixed fraction of the actuating fluid delivered to it. Any of the actuating uid or fuel which leaks past the plunger 44 passes out through special leakage passageways 84 and 86.

Thus, the pump operates to sequentially deliver measured amounts of fluids through the delivery openings which are connected to the injectors of the engine. The amount of actuating tiuid delivered to each of the injectors is the same for each injector, thus achieving a uniform fuel injection for each injector. Further, the amount of fuel injected can be closely varied through an infinite variation of adjustment within the range of 'movement of the sleeves which carry the control orifices.

These variations in control and the delivery of metered amounts of actuating uid are provided by the pump illustrated in Figures 4 through 10.

The metering pump of Figures 4 through 10 The pump is illustrated with its working mechanism contained in a hollow cylindrically shaped housing 232. The housing is opened at the top for purposes of assembling the pump mechanism and the opening is closed by a cylindrical disk 234 which is locked in place by a split spring ring 236 which expands into a groove 238 in the housing 232. The disk is locked against rotation by a key 240 positioned in a key slot in the housing and in the disk 234.

The disk is shown from its underside by the sectional view of Figure 5. As illustrated in that figure, the disk is provided with a plurality of discharge openings 242 through 258. Each of the discharge openings are threaded as shown in Figure 4 for purposes of attaching a line leading to the fuel injector. Thus a separate discharge opening is provided for each injector, and the injectors of the type shown in Figure 1 may be used. The pump operates to successfully deliver a measured amount of aetuation nid to each injector, and each injector will in turn deliver a predetermined fractional amount of fuel to its respective cylinder. On the under surface of the cylindrical disk 234 are provided slots such as 260 and 262 leading to the

discharge openings

242 and 252. Individual slots are provided for each of the discharge openings to permit communication with the discharge outlet 254 of the pump rotor, as shown in Figure 4. The pump rotor 266 is rotationally positioned within the housing 232 of the pump and is mounted at the upper end of the rotational drive shaft 268. The rotor has a discharge outlet 254 and an inlet opening 270. These two openings communicate with the hollow transverse central bore 272 of the pump. The bore is cylindrical in shape and carries the pumping pistons shown in the preferred form in the form of

balls

274 and 276. The pumping pistons or

balls

274 and 276 reciprocate within the cylindrical pumping chamber 272 simultaneously toward and away from each other to cause a discharge and an intake stroke. This operation of the pumping balls is caused by an annular cam ring 278. The cam ring is stationary within the pump housing 232 and is keyed against rotation by key 230 positioned in keyways in the inside of the housing and in the peripheral edge of the cam ring 278. The inner surface of the annular cam ring 278 is provided with undulations and the series of rounded raised portions 282 force the balls inwardly on the discharge stroke. The depressions 284 between the raised portions permit the

balls

274 and 276 to move outwardly, causing an intake stroke of the pump. The rotor 266 is of course rotating at a speed sufiicient to cause the centrifugal force on the balls to carry them outwardly into the depressions 284 of the annular cam ring. The balls will be constructed to have suicient weight to draw actuating fluid into the pumping chamber through the intake opening 270 when they move outwardly. The discharge outlet 264 is sealed by being connected to the fuel injector, and each time the balls move away from each other a fresh charge of fluid will be drawn into the chamber 272 through the inlet 270. When the balls are forced inwardly toward each other, the inlet opening 270 is closed and the actuating fluid is forced outwardly through the discharge outlet 264.

As the rotor 266 rotates, the discharge openings 264 will be aligned with successive delivery openings 242 through 258 to successfully cause operation of different fuel injectors. The inlet opening 270 into the pump chamber 272 will also successfully communicate with inlet ports 286 through 300 in the circular control plate 302, as shown in Figures 4 and 8. The inlet ports in the control plate each are in communication with an annular channel 304 in the base of the housing 232. The channel 304 is fed a supply of actuating fluid through a passageway 306 from a gear pump which supplies oil thereto at a slight pressure which is insufficient to operate the fuel injector. The gear pump is shown at 308 and is supplied from a supply passageway (not shown). The gear pump includes gear element 310 rotatably journaled between the housing 232 and the base member 312 and also the gear pump member 314 which is connected to lbe driven by the pump drive shaft 268. The actuating `fluid supply passageway 366 leading from the gear pump has a ball relief valve 316. This valve consists of a ball 316 held in place by coil compression spring 318 in a chamber 320. The spring bottoms on a ring 322. The ball 316 is held in place over the lower end of the fluid passageway 306 with sufficient pressure that it will seal the passageway with ordinary pressures of the gear pump 308. Chamber 320 is connected to leak to a reservoir. Excessive pressures, such as are encountered when the discharge of the actuating fluid is controlled by 'permit- 9 ting the latter portion delivered therefrom to spill back into the inlet opening, will open the check valve 316 to permit the escape of liuid back to the reservoir.

To control the amount of fiuid discharged by the pump, the control plate 302 is adjustable in rotation and carries the elongated ports of orifices 286 through 300 which act as intake orifices and also as spill orifices. This action is illustrated in Figures 10a and 10b. Using the intake and spill orifices 286 and 28S for illustration, the intake opening 270 is seen positioned over the inlet orifice 286 when the pump is in the intake stroke and the

balls

274 and 276 are moving outwardly. As the rotor 266 rotates, the intake opening 270 will be positioned between the

intake orifice

286 and 288 when the pump is moving in its discharged stroke. This prevents the escape of any of the fluid in the pump chamber 272 and forces the actuating fiuid to be pushed out through the outlet 264.

1n Figure 10b, however, the control plate 382 has been advanced. This advancement moves the control plate opposite to the direction of rotation of the rotor 266 so that when the pump is on its intake stroke the intake opening 27) will be at the trailing end of the intake orifice 286. This does not interfere With the intake of actuating fiuid. When the pump is discharging near the end of the discharging stroke, the rotor 266 will have moved so that the intake opening 270 will have moved over the succeeding intake orifice 288 whereby it acts as a spill orifice. With the intake opening 270 shown in the dotted position of Figure 10b, the fluid within the pump can be pushed out through the intake orifice 288. This intake orifice is in communication with the annular channel 304 and the fiuid can thus be lpushed out against the ball check valve 316 'which has a lower resistance than the injector to which the pump delivers. Thus the pump will continue delivering fluid in its discharge stroke only until the in- .take .opening 270 reaches a point where it can spill through the next intake orifice.

, This action will follow for each of the succeeding intake orifices and the pump Will spill lthrough the orifice after the one which acts as an intake orifice if the control plate 302 is advanced.

The control plate has a central opening 324 and ismounted on the shaft 268 for rotation within its openings in the housing 232. Its position is controlled by an adjustment arm 326 which extends upwardly through an arcuate slot 328, Figure 9, in the housing 232. The vposition of the arm 326 is controlled by a lever 330 having an elongated slot 332 in its end and to push the arm 326 in either direction. The lever 330 is pivotal- 1y mounted in the frame by being secured to va pivotal support 334. It twill thus be seen from Figures 4 and 9 that rotation of the lever 330 will push the arm 326 inA either direction in the'slot 323 and will rotate the control plate 302. This will determine the position of the slotted

orifices

286 and 300, thus determining the quantity of, actuating fiuid delivered in each stroke of the pump. 'Since all of the intake orifices are moved concurrently and for an equal distance, the amount of acltuating fluid delivered by each successive stroke of the pump, or each successive injector mechanism, will be identically adjusted. n

` v Although the operation of the pump will be clear from the foregoing description and discussion of the co- Iaction of the individual elements, a brief description of the overall operation will be helpful in reviewing the objectives, advantages and attainments of the invention.

The pump rotor 266, which is housed in the housing 232, is driven by a supporting shaft 268. The pistons orballs 274 and 276 move simultaneously toward or away from each other in the discharge and intake stroke to ,force actuating fluid from the cylindrical lateral cham- .ber extendingV through the pump rotor 266. The fluid-is forced from the pump chamber 272 out through .the Voutlet 264 which sequentially communicates Vwith 10 the successive discharge openings 242 to 258, whichare in turn connected to individual fuel injectors.

Actuating fluid is drawn into the pump chamber 27 through an inlet opening 270 which communicates with the successive intake orifices 286 to 300. During at least a portion of the discharge stroke, the inlet opening 270 is positioned over the solid portion of the control plate 302 so that the actuating fiuid is forced out through the outlet 264. Depending upon the adjustment of the control plate 302, the inlet opening 270 may be moved over an inlet orifice such as 286 or 288 before the kpump has completed its discharge stroke. This 'will cause the inlet orifice to act as a spill orifice, permitting the rest of the actuating fluid to be forced out through the inlet opening 270 rather than being delivered to the fuel injector. Thus by rotational adjustment of the control plate 302, which is accomplished by the lever 330, the delivery of actuating fluid to each of the injectors will be simultaneously and uniformly varied.

Thus it Will be seen that I have provided a fuel injection system which meets the objectives and advantages hereinbefore set forth. The injector lis an improved simplified and compact unit which is capable of complete atomization of measured amounts ofl fuel. It is constructed as a small compact unit and the determination of the amount of fuel delivered will be made entirely by adjustment of the pump for delivering the actuating uid. Since the injector delivers a fixed fraction of the amount of actuating uid, very accurate fine adjustments of fuel delivered can be made by larger adjustments of actuating fiuid delivered by the metering pump. Also, the metering pump can operate at lower pressures and therefore high pressure operation of the injectors can be accomplished. The metering pump accurately delivers a measured equal amount to each of the injectors, and with a single adjustment equal amounts of delivery by each of the injectors can be precisely obtained.

The pump is illustrated in the preferred embodiments of the invention which attain the advantages of a compact simple unit which is capable of easy and precise accurate adjustment of the amount of fluid metered. i I have, in the drawings and specification, presented a detailed disclosure of the preferred embodiments of my invention, but it is to be understood that I do not in- (tend to limit the invention to the specified forms disclosed but intend to cover all modifications, changes 'and alternative constructions and methods falling within the scope of the principles taught by my invention.

I claim as my invention:

v 1. A device for fuel injection comprising a fuel injection plunger, a fuel injection housing having a chamber therein in which said plunger is movably mounted for movement in an intake stroke and a discharge stroke, said chamber terminating in a discharge port at one end and in an intake port at the other end, said plunger moving in a direction to force and trap fluid in said chamber out of said discharge port in said discharge stroke, a chamber in said housing for the receipt of plunger actuation fluid, an actuation surface movable in said chamber and operatively connected to the plunger to move it in a discharge stroke when pressurized actuating fiuid is admitted lto said chamber, an actuation Huid pump conlnected to be in communication with said actuation chamber to deliver the fluid thereto to cause the plunger to move in a discharge stroke, and means for varying the discharge of said pump to vary the stroke of said plunger to'obtain variable fuel discharge from the plunger in the discharge stroke.

2. A mechanism for injecting fuel into an internal combustion engine comprising a fuel injection housing having a fuel intake and a fuel discharge port, an injection plunger movably positioned in a fuel chamber in said housing to move in an intake and a discharge stroke, an actuation fluid chamber in said housing, an actuation surface on said injector movable in said actuation chamber to move the injectionvplunger in the discharge stroke in a direction to force fuel entrapped in 'said fuel chamber out through saiddischarge port when pressurized actuating fluid is admitted to said chamber, an actuation fluid pump in communication with said chamber to deliver an actuating fluid thereto, a movable pump plunger in said actuation pump, a chamber within the actuation pump within which the pump plunger moves, a conduit connecting between the pump chamber and the actuation fluid chamber in the injection housing, a pressure relief conduit associated with the pump plunger, a conduit through the pump plunger adapted to communicate with the pressure relief conduit when the plunger has reached a predetermined position to relieve the pressure of the actuating fluid delivered "by the pump at a certain point in the stroke of the pump plunger, and means for varying the time when said pressure relief conduit communicates with said plunger conduit relative to the position of the plunger in movement so that the quantity of discharge of the plunger is varied and the quantity of fuel delivered by said injection plunger is correspondingly varied.

3. A device for injecting fuel into an internal combustion engine comprising an injector housing having a fuel chamber a fuel intake port and a fuel discharge port to be connected to deliver fuel to an engine, an actuation fluid pressure chamber within the housing, a fuel injection plunger movable within the housing in a discharge stroke to force entrapped fuel to deliver fuel entrapped in said fuel chamber from the discharge port, a reaction surface movable in response to actuation fluid pressure within the fluid pressure chamber and operatively connected to the injection plunger to cause actuation thereof when actuating fluid is admitted to the actuation chamber, and an actuation pump positioned remotely from the injector housing of said pump adapted to intermittently deliver measured quantities of actuation fluid to the injector housing to cause a measured delivery of fuel from the injector` 4. A pump for intermittently discharging metered quantities of an actuating fluid to drive a fluid actuated fuel injector comprising a casing defining a cylinder therein for the pressure discharge of actuating fluid and having a discharge port communicating with said cylinder, a piston movable within said cylinder in an intake and a discharge stroke, means for reciprocating the piston within the cylinder, means dening a relief passageway communicating with the cylinder, means defining a second relief passageway to be aligned with the first passageway for the relief of fluid pressure within the cylinder near the end of said discharge stroke, means for giving relative movement to said passageway means with the movement of the piston to relieve the pressure at a predetermined point in the movement of the piston to thereby control the amount of fluid delivered by movement of the piston in a discharge stroke, and means for returning the discharged actuating fluid to said discharge port on the intake stroke of said piston to be used for a succeeding discharge stroke.

5. A pump for intermittently discharging metered quantities of an actuating fluid to drive a fluid actuated fuel injector or the like comprising a casing defining a fluid delivery cylinder therein communicating with a discharge port, a piston movable within said chamber in an intake stroke and a discharge stroke for the discharge of pressurized actuating fluid, a member defining a control orifice for conducting fluid away from the chamber at a predetermined point in the piston discharge stroke, a relief orifice movable with the piston and adapted to be in communication with the control orifice at a predetermined point in the discharge stroke of the piston to relieve the fluid pressure therein and limit the fluid discharged through the discharge port by the stroke of the piston, and means for returning the discharged actuating fluid through said discharge port on the intake stroke of said piston to be used for a succeeding discharge stroke.

6. A device for fuel injection comprising a fuel injector housing having a chamber therein with a fuel injection discharge port and fuel intake port, a fuel injection plunger movable within the housing chamber and operable to discharge an amount of fuel in movement in a discharge stroke, an actuator pump for delivering actuating fluid to the injector, and means connected to said actuator pump and operative to cause the injector plunger to move in the discharge stroke with a delivery of actuator fluid from the actuator pump, said injector plunger delivering an amount of fuel which is a fixed fraction of the amount of fluid delivered by the actuator pump.

7. A device for fuel injection comprising a fuel injector plunger having a discharge surface and an actuation surface and movable in a discharge stroke to deliver an amount of fuel to a combustion engine, a housing for said injector plunger having a fuel chamber therein defining a path of movement for the plunger in the discharge stroke, means defining a discharge port opening from said chamber, said plunger moving said discharge surface in a direction to force entrapped fuel out of said port in said discharge stroke, means defining an actuating chamber positioned so that said actuating surface of the plunger is exposed to said chamber, said discharge surface being smaller than said actuation surface whereby the discharge fluid is less than the quantity of actuation fluid for a discharge stroke, an actuator fluid pump delivering measured amounts of actuating fluid to said actuating chamber, and means to adjust the amount of actuating uid delivered rby the pump whereby the fuel discharged is a fractional function of the fluid delivered by said pump.

8. An actuation pump for delivery of a metered quantity of actuating fluid in a fuel injection operation, a piston movable in an intake stroke and in a discharge stroke to discharge a quantity of actuating fluid, a housing defining a chamber therein within which said piston is slidably mounted and having a discharge port, means for reciprocating the piston, a pressure relief orifice extending through the piston to be vented at a predetermined point in the stroke of the piston to determine the amount of fluid delivered by the piston in its stroke, a relief control orifice member having an orifice therein and positioned for the pressure relief orice inthe piston move into alignment therewith at a predetermined point in the piston stroke, and means for returning the delivered actuating fluid under pressure to said chamber during said intake stroke of the piston to be used for a succeeding delivery stroke.

9. An actuation pump for delivering a metered amount of fluid comprising a housing defining a fluid chamber therein, a piston movable within the chamber and operable to deliver a quantity of fluid through a discharge opening in the housing in communication with said chamber, an intake opening into said chamber extending through said housing, a cam actuator in engagement with said piston to force it into the chamber and cause a pressure discharge of fluid therefrom, and a leakage passageway from the chamber leading to the surfaces of engagement .between the cam and the piston to lubriacte the engaging surfaces with the uid being pumped by the piston.

l0. A housing having a plurality of pressure chambers arranged in a circle and discharge openings leading therefrom, a plurality of pistons each reciprocable in one of said chambers to force fluid therefrom, and a rotating cam for operatively engaging and moving the pistons in the reciprocable movement, said cam having a continuous annular surface for engaging and axially moving the pistons and having its axis offset from the center of said chamber arrangement so that the cam will engage the pistons with a changing radius to change the surface engaging with rotation and reduce the Wear.

11. A pump for delivering a' pressurized fluid for operating a fuel injector for an internal combustion or the like comprising a piston for delivering a charge of fluid for driving a fuel injector for a combustion chamber, a chamber for the piston provided with a delivery opening and an intake opening, a relief orilice in the piston for spilling the fluid from the chamber when the piston reaches a certain point in its discharge travel, an element having a metering relief control orifice adapted to be placed in alignment with the relief orifice to permit the uid to escape from the piston, a control member connected to the control orifice element and operative to change the position of the control oriiice member with movement, and an adjuster interposed in the control member and responsive to temperature and pressure of the engine manifold to vary the position of the control orifice irrespective of the setting of the control member.

12. A pump for delivering a pressurized fluid for operating a fuel injector for an internal combustion engine or the like comprising a housing defining a pressure chamber therein and a delivery opening in communication therewith, a piston movable Within said chamber to deliver a fluid through said delivery opening, a relief orifice in said piston in communication with the chamber, a control orifice element having a surface in slidable engagement With the piston and having a control orice therethrough to be aligned with the relief orifice of the piston for release of the pressure within the chamber, a control member operatively connected to the control surface element and operative to change the position thereof to control the output of the pump, sensing means responsive to operating conditions of an engine which aiect the desirable quantity of fuel to be delivered to the engine and adapted for connection to the engine, and means interposed in said control member and connected to said sensing means and operated thereby to enter a factor responsive to engine conditions for varying the speed thereof regardless of the setting of the control member.

References Cited in the file of this patent UNITED STATES PATENTS 2,245,562 Becker June 17, 1941 2,291,939 Amery Aug. 4, 1942 2,391,174 Lownsbery Dec. 18, 1945 2,401,579 Miller June 4, 1946 2,458,294 Parker Jan. 4', 1949 2,470,717 Palumbo May 17, 1949 2,473,412 BryantI June 14, 1949 2,588,481 Chandler Mar. 11, 1952 2,688,286 Friedlander Sept. 7, 1954 2,793,630 Halik May 28, 1957 2,810,376 Aldinger- Oct. 22, 1957