US3177860A - Liquid fuel injection pumps for internal combustion engines - Google Patents

Description

April 13, 1965 P. E. GLIKIN 3,177,860

LIQUID FUEL INJECTION PUMPS FOR INTERNAL COMBUSTION ENGINES Filed Aug. 1, 1963 2 Sheets- Sheet 1 5o 5 NA 6O 54 5e 5o" 7 as 55 {2 M 722 y 54 K F/G/O April 13, 1965 p, GLlKlN I 3,177,860

LIQUID FUEL INJECTION PUMPS FOR INTERNAL COMBUSTION ENGINES Filed Aug. 1, 1963 2 Sheets-Sheet 2 United States Patent O 29,698 Ulaims. (Cl. 123-439) This invention relates to liquid fuel injection pumps for internal combustion engines, and of the kind comprising a reciprocable plunger for effecting the injection in timed relationship to an engine with which the pump is associated, regulating means for varying the quality of fuel delivered at each injection stroke of the plunger, a feed pump adapted to be driven by the engine for feeding fuel to the injection pump, and a cylinder containing a fluid operable piston for varying the timing of the injection, said piston being subjected to a pressure dependent upon the pressure of fuel delivered by the feed pump.

The object of the invention is to provide such a pump in an improved form.

According to the invention in a pump of the kind specitied ,the cylinder is arranged to be supplied with fuel by the feed pump under the control of a valve member, movable axially in a chamber to control the flow of fuel through a passage and thereby modify the pressure acting on the piston, a spring acting between the valve member and an abutment, and means for varying the axial setting of the abutment in accordance with variations of the setting of said regulating means.

In the accompanying drawings: FIGURE 1 is a sectional side elevation of one example ofa liquid fuel injection pump to which the invention is applied,

FIGURE 2 is a section on the line 22 of FIGURE 1.

FIGURE 3 is a section on the line 33 of FIGURE 1.

FIGURE 4 is a section on the line 4-4 of FIGURE 1.

FIGURE 5 is a section on the line 5-5 of FIGURE 1.

FIGURE 6 is a modification of part of the pump shown in FIGURE 1.

FIGURE 7 is a modification of part of the pump shown in FIGURE 1.

FIGURE 8 is a modification of part of the pump shown in FIGURE 1.

FIGURE 9 is a modification of part of the pump shown in FIGURE 1, and

FIGURE 10 is also-a modification of part of the pump shown in FIGURE 1.

' regulating valve includes a spring loaded valve member 5 which, as shown in FIGURE 1, is able to close a passage Sa interconnecting the outlet 4 and inlet 3 of the feed pump. As the flow through the passage 5a increases (as the speed of-rotation of the impellor increases) the valve member will be lifted and the pressure at the outlet will increase because the spring has to be compressed more. Thus the pressure at the outlet of the pump is dependent upon the speed of the engine. It should be noted that the feed pump is arranged to deliver a much greater quantity of fuel than is required by the engine so that there is always fuel flowing in the passage 5a even when the engine is being cranked for starting purposes. At the other end of the body part is contained the fuel injection pump comprising a rotary head 6 formed at one end of a distributor 7 serving to interconnect the rotary parts of the-feed and injection pumps. Moreover the head is coupled to a drive shaft 12 which is adapted to be driven in synchronism with the engine with which the pump is associated. In the head is a transverse bore 8 containing a pair of reciprocatory plungers 9 which through rollers It? at their outer ends respectively co-operate with a surrounding annular cam 11.

In the body part I is a radially extending cylinder 13 the inner end of which is arranged to be placed in communication in turn as the distributor 7 rotates with a plurality of radially disposed-equi-angularly spaced inlet passages 14 in the distributor.. These passages are in communication with an axial passage 15 in the distributor which at one end is in communication with the bores in the head and atits other end is in communication with a radial passage 16 which is arranged to register in turn, as the distributor rotates, with a plurality of delivery ports 17 in the body part which are adapted for connection to the injection nozzles (not shown) of the engine cylinders.

The inner end of the cylinder 13 is arranged to register in turn, as the distributor rotates, with a plurality of equi- 21, in the body part and contained within the cylinder is an axially movable shuttle 22 the outward movement of which is controlled by an axially movable stop 23.

The arrangement is such that when the distributor rotates fuel from the feed pump flows through the passage 2d, the groove 19 and one of the grooves 18 to the inner end of the cylinderlS to move the shuttle 22 outwardly against the stop 23 during the time when the plungers 9 are moved inwardly by the cam 11 there being provided a further passage 24 in the body part which at one'end is in communication with the outer end of the cylinder 13 and at its other end is adapted to register in turn with a further set of equi-angularly spaced longiudinal grooves 25 in the distributor to permit the escape of fuel from the outer end of the cylinder to the inlet 3 of the feed pump. 7 v.As the-plungers 9 are moved inwardly fuel'is dispaced 'from the bore and flows through the passage. 15, and the delivery passage 16 to an outlet port 17. As the distributor further rotates fuel from the feed pump is feed to the outer end of. the cylinder 13 through the passage -20, the groove19, one of the grooves 18 and the passage 21 and the shuttle 22 is moved inwardly to cause the fuel previously feed to the inner end of the cylinder to be passed to the bore in the head, to more the plungers 9 outwardly via one of the plurality of inlet passages 14 and the axial A, passage 15. Thus by varying the axial setting'of the stop 23 the quantity of fuel deliveredby the pump to the engine can be varied. Conveniently the axial setting of the stop 23 is controlled by an angularly adjustable cam plate 26 the angular setting of which is controlled through an arm 27. by a mechanical governor (not shown) or by an attendantoperable throttle and the maximum movement of which is limited by a stop 26a.

A further cylinder 28 is formed in the body part adjacent the injection pump with its axis extending parallel to a tangent to the annular cam II. In the cylinder is a piston 29 which is loaded towards one end of the cylinder by a coiled compression spring 30 acting between the pis- Patented Apr. 13, 1965 28 via a .pipe 33 and at its other end with the circumfercntial groove 19; Located between the end of the pipe 33 and the cylinder is a non-return valve 33a which only "closes, to prevent flowof fuel from the cylinder to the pipe 33, when the piston 29 is moved owing to the reaction of the rollers with the annular cam. This valve drops open to allow fuel to flow out of the cylinder under the influenceof the spring, the rate of flow of fuel being insufiicient to hold. or move the valve member to the closed position. Thus theadjustment of the lining takes place between successive injection strokes. Within the chamber is an axially movable spool 34 and at the one end of the chamber is an axially movable abutment 35. The axial position of the abutment is controlled by the aforementioned cam plate 26 and interposed between the abutment and the spool is a coiled compression spring 36. In the wall of the chamber 32 is a port 37' which is in communication with the end of the chamber containing the spring and which when the spool is in a position of equilibrium is arranged to be covered by a land on the spool. Furthermore an annular groove in the spool is maintained in communication with the inlet of the feed pump via a passage 38 which leads into the space surrounding the head which is in communication via a passage 38a with the inlet of the feed pump.

In use if the cam plate 26 is moved to reduce the quantity of fuel delivered to the engine the abutment 35 will be moved to reduce the force applied by, the spring 36 to the spool and the fuel pressure applied to the end of the spool will move the spool to uncover the port 37 so as to permit fuel to flow from the groove 19 to the cylinder 28 to urge the piston 29 against the action of the spring 30,, thereby altering the timing of injection of fuel to the engine. As the pressure on the end of the spool adjacent the spring rises the spool will be moved to cover the port 37. The spool will remain in this position so long as the outlet pressure of the feed pump, and the setting of the abutment remain constant. If either of these change the forces on the spool will be unbalanced and the port 37 will again be uncovered to allow fuel to enter or leave the cylinder 28 depending upon the direction of movement of the spool. Thus in this example the timing of injection of fuel to the engine is responsive to both the speed of, and the quantity of fuel supplied at each injection stroke to the, engine. Under. normal operating conditions the rate at which fuel is supplied to an engine is roughlyproportioned to the torque developed by the engine, and since the torque developed by an engine is the same as the load on the engine it follows that in this example the timing of injection of fuel to the engine is responsive also to the load on the engine.

In apmodification as shown in FIGURE 6 the chamber 32 has a portion of reduced diameter at its end which is in communication with the circumferential groove 19. Within the chamber is a complementarily shaped valve member 40 through which extends a passage 40a incorporating a restricted orifice. The end of the wider portion of the chamber adjacent the narrow portion thereof is in communication with the space surrounding the head 'through the aforementioned passage 38 and is also in communication with a spill port 41 in the wall of the chamber. The spring 36, the abutment member 35 and the passage 33 are provided as in the previous example. The operation of this modification is as follows. Assuming the fuel pump is running at a constant speed and the setting of the cam member is fixed fuel will flow through awaseo the orifice and passage and the pressure in the portion of the chamber which is in communication with the cylinder 28 will be maintained at a value, by leakage of fuel through the port 41, so that the combined force due to the spring and said pressure acting on the wider end of the valve member will balance the force exerted by the pressure at the outlet of the feed pump acting on the narrower end of the valve member. If either the force applied by the spring or the force due to the fuel pressure exerted on the narrower end of the valve member changes when for instance there is a load change or a speed change respectively the valve member. will move to alter the efiective size of the port 41 and so alter the fuel pressure acting on the wider end of the valve member to maintain the equilibrium. Since the pressure acting .on the Wider end of the valve member is applied to the piston 29 the timing of injection of fuel to the engine will be varied.

In a modification of the above shown in FIGURE 7 the chamber is of cylindrical form and accommodates a valve member 42 in which is formed a restricted orifice 43. Moreover in this example the passage 38 terminates in a spill port 44 which is arranged to be partially covered, to vary its effective size, by a part of the valve member. The mode of operation of this example is the same as the previous example.

In a still further example illustrated in FIGURE 8 the chamber is again cylindrical and incorporates a baffle 46 in which is formed a restricted orifice 47. The valve member 45 as in the previous example is arranged to uncover a port 48 formed in the wall of the chamber and which is in communication with the passage 38. The operation of this example is slightly different from the previous examples in that the valve member is not subjected to the outlet pressure of the fuel pump but only to the pressure which is applied to the piston. Consequently the pressure applied to the piston is a function of the amount of fuel supplied to the engine only.

In a modified form of the pump part of which is shown in. FIGURE 9 the cam plate 26 is replaced by a plunger 50 which is slidably mounted in a cylinder 51. One end of the cylinder is in communication with the outlet 4 of the feed pump with the result that the plunger is urged away from the one end of the cylinder by the pressure of fuel from the feed pump. For resisting this movement there is provided a governor spring 52 which is mounted between the plunger and a pivoted control lever 53 the setting of whichis controlled by an operator. Formed on the plunger at diametrically opposite points are a pair of cam forms 54, .55. and bearing against one of the cam forms 54 is the shuttle 22. The other cam form 55 controls the setting of the abutment 35 of the valve the construction and operation of which, is thesame as the .valve shown in FIGURE 1. i The plunger in conjunction with the governor springs acts as an hydraulic governor to control the quantity of fuel delivered to the engine in accordance with the requirements thereof. Moreover for limiting the maximum quantity of fuel which can be delivered by the pump a stop 50a is provided.

In a further modification of the valve'as shown in FIG- URE 10 which also usesthe hydraulic governor shown in FIGURE 9 the valve member is provided with three lands. The centre land is arranged to cover a port 56 in the wall of the cylinder containing the valve member when the latter is ina state of equilibrium. Moreover the spaces on each side of the centre land are arranged to be in communication with the feed pump outlet and inlet through passages 57 and 58 respectively. The port 56 is in communication with the cylinder 28 and is also in communication with the space between the valve member and the abutment 35 which space contains a spring 59. Furthermore located between the end of the valve member remote from the spring 59 and the adjacent end of the chamber is a further spring 60 and the arrangement is such that when the setting of the abutment is altered the valve member will move to uncover the port 56 to allow fluid to flow to or from the end ofthe chamber containing the spring 59 to restore the balance of the forces acting on the valve member and since the port 56 is also in communication with the cylinder 28 the timing of injection of fuel to the engine will also be varied.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. Liquid fuel pumping apparatus for supplying fuel to an internal combustion engine and comprising a pump body, an injection pump mounted within the body for effecting the injection of fuel in timed relationship to an engine with which the apparatus is associated, a feed pump mounted within the body for supplying fuel from a source to the injection pump, a relief valve for controlling the output pressure of said feed pump so that said pressure is dependent upon the speed of the engine, regulating means for controlling the quantity of fuel delivered by the injection pump, a member associated with said regulating means, said member being adjustable to determine the setting of said regulating means, a cylinder formed in the body, a fluid pressure operable piston mounted in said cylinder, said piston being movable to control the ti ning of injection of fuel to the engine, a passage through which fuel from the feed pump is fed to one end of said cylinder, a chamber in the body part one end of said chamber being open to the fluid pressure developed at the outlet of the feed pump, an abutment slidable in said chamber, the setting of said abutment being determined by said member, a valve member slidable in said chamber for controlling the flow of fuel to said cylinder said valve member being acted upon by the fluid pressure in said one end of the chamber, and resilient means mounted intermediate the abutment and the valve member, whereby the flow of fuel to said cylinder is determined by the pressure of fuel developed at the outlet of the feed pump and the setting of said member.

2. Liquid fuel pumping apparatus for supplying fuel to an internal combustion engine and comprising a pump body, an injection pump mounted within the body for effecting the injection of fuel in timed relationship to an engine with which the apparatus is associated, a feed pump mounted Within the body for supplying fuel from a source to the injection pump, a relief valve for controlling the output pressure of said feed pump so that said pressure is dependent upon the speed of the engine, regulating means for controlling the quantity of fuel delivered by the injection pump, a member associated with said regulating means, said member being adjustable to determine the setting of said regulating means, a cylinder formed in the body, a fluid pressure operable piston mounted in said cylinder, said piston being movable to control the timing of injection of fuel to the engine, a passage through which fuel from the feed pump is fed to one end of said cylinder, a chamber in the body part one end of said chamber being open to the fluid pressure developed at the outlet of the feed pump, an abutment slidable in said chamber, said abutment being acted upon by said member to determine the axial setting thereof, and having one end exposed to the pressure of fuel in said one end of the chamber, a spool slidable in said chamber, a spring interposed intermediate the spool and the abutment, a pair of axially spaced lands formed on the spool, a port formed in the wall of the chamber, said port forming part of said passage means and being arranged to be covered by one of said lands when the valve member is in an equilibrium position, as determined by the force exerted by the spring and the pressure of fuel acting on the spool, a conduit connecting the position of the chamber containing the spring with said port, and a further conduit connecting the space intermediate the lands with a source of fuel at a lower pressure than that of the outlet of the feed pump, the arrangement being that if the setting of the abutment and hence the amount of fuel supplied to the engine is varied and/or the outlet pressure of the feed pump varies the spool will move to uncover the port and 7 allow fuel to flow therethrough thereby varying the pressure of fuel in the cylinder and the portion of the charm: 7 her containing the spring, until the spool is restored to the elfecting the injection offuel in timed relationship to an enginerwith which the apparatus. is associated, a feed pump mounted Within the body for supplying fuel from a source to the injection pump, a relief valve for controlling the output pressure of said feed pump so that said pressure is dependent upon the speed of the engine, regulating means for controlling the quantity of fuel delivered by the injection pump, a member associated with said regulating means, said member being adjustable to determine the setting of said regulating means, a cylinder formed in the body, a fluid pressure operable piston mounted in said cylinder, said piston being movable to control the timing of injection of fuel to the engine, a

passage throughwhich fuel from the feed pump is fed to,

one end of said cylinder, a chamber in the body part one end of said chamber being open to the fluid pressure developed at the outlet of the feed pump, an abutment slidable in said chamber, said abutment being acted upon by said member to determine the axial setting thereof, a. 7

piston slidable in said chamber and having one end exposed to the pressure of fuel in said oneend of the chamber, a spring interposed intermediate the piston and said abutment, a restriction in said passage means, and a spill port, the size of which is controlled by the setting of the piston, communicating with said passage means at a position intermediate the restriction and the cylinder, the portion of the chamber housing the spring being in communication with said cylinder, whereby in the event of the setting of the abutment and/ or the outlet pressure of the feed pump varying the piston will move to vary the size of the spill port to maintain the forces acting on the piston in equilibrium.

4. Liquid fuel pumping apparatus for supplying fuel to an internal combustion engine and comprising a pump 'body, an injection pump mounted Within the body for effecting the injection of fuel in timed relationship to an engine with which the apparatus is associated, a feed pump mounted Within the body for supplying fuel from a source to the injection pump, a relief valve for controlling the output pressure of said feed pump so that said pressure is dependent upon the speed of the engine, regulating means for controlling the quantity of fuel delivered by the injection pump, a member associated with said regulating means, said member being adjustable to determine the setting of said regulating means, a cylinder formed in the body, a fluid pressure operable piston mounted in said cylinder, said piston being movable to control the timing of injection of fuel to the engine, a passage through which fuel from the feed pump is fed to one end of said cylinder,

a chamber in the body part one end of said chamber being open to the fluid pressure developed at the outlet of the feed pump, an abutment slidable in said chamber, said abutment being acted upon by said member to determine the axial setting thereof, a spool slidable in the chamber, a first spring interposed between the spool and the abutrnent, said spool having two outer lands and an inner land, a port in communication with said cylinder, the inner land of the spool being disposed to control the flow of fuel through said port, a conduit serving to interconnect the portion of the chamber containing the first spring and the cylinder, a second spring mounted at said one end of the chamber and disposed to act on the spool in opposition to said first spring, the reduced portion of the spool intermediate the inner land and the outer land adjacent the second spring being in communication with a source of fuel at a lower pressure than the outlet of the feed pump and the other reduced portion of the spool 'being'in communication with the outlet'of the feed pump, -whereby When'thesetting of the abutment and/or the pressure or fuel deliveredbyuthe feed pump varies the 1 in which the member is in the form of a fluid pressure operable plunger, one end of which is exposed to the outis acted upon by a governor-spring, the strength-of the spring being variedin accordance with the fuel requirementof the engine, the plunger being provided with-a cam face against which the abutment bears.

j References Cited by theExaminer I UNITED STATES PATENTS 2,699,766 1/55 Fodor et a1. 123-139 let pressure of the feed pump and the other end of which 10 RICHARD B. WILKINSON, Primary Examiner.

Claims (1)

1. LIQUID FUEL PUMPING APPARATUS FOR SUPPLYING FUEL TO AN INTERNAL COMBUSTION ENGINE AND COMPRISING A PUMP BODY, AN INJECTION PUMP MOUNTED WITHIN THE BODY FOR EFFECTING THE INJECTION OF FUEL IN TIMED RELATIONSHIP TO AN ENGINE WITH WHICH THE APPARATUS IS ASSOCIATED, A FEED PUMP MOUNTED WITHIN THE BODY FOR SUPPLYING FUEL FROM A SOURCE TO THE INJECTION PUMP, A RELIEF VALVE FOR CONTROLLING THE OUTPUT PRESSURE OF SAID FEED PUMP SO THAT SAID PRESSURE IS DEPENDENT UPON THE SPEED OF THE ENGINE, REGULATING MEANS FOR CONTROLLING THE QUANTITY OF FUEL DELIVERED BY THE INJECTION PUMP, A MEMBER ASSOCIATED WITH SAID REGULATING MEANS, SAID MEMBER BEING ADJUSTABLE TO DETERMINE THE SETTING OF SAID REGULATING MEANS, A CYLINDER FORMED IN THE BODY, A FLUID PRESSURE OPERABLE PISTON MOUNTED IN SAID CYLINDER, SAID PISTON BEING MOVABLE TO CONTROL THE TIMING OF INJECTION OF FUEL TO THE ENGINE, A PASSAGE THROUGH WHICH FUEL FROM THE FEED PUMP IS FED TO ONE END OF SAID CYLINDER, A CHAMBER IN THE BODY PART ONE END OF SAID CHAMBER BEING OPEN TO THE FLUID PRESSURE DEVELOPED AT THE OUTLET OF THE FEED PUMP, AN ABUTMENT SLIDABLE IN SAID CHAMBER, THE SETTING OF SAID ABUTMENT BEING DETERMINED BY SAID MEMBER, A VALVE MEMBER SLIDABLE IN SAID CHAMBER FOR CONTROLLING THE FLOW OF FUEL TO SAID CYLINDER SAID VALVE MEMBER BEING ACTED UPON BY THE FLUID PRESSURE IN SAID ONE END OF THE CHAMBER, AND RESILIENT MEANS MOUNTED INTERMEDIATE THE ABUTMENT AND THE VALVE MEMBER, WHEREBY THE FLOW OF FUEL TO SAID CYLINDER IS DETERMINED BY THE PRESSURE OF FUEL DEVELOPED AT THE OUTLET OF THE FEED PUMP AND THE SETTING OF SAID MEMBER.

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