US3179100A - Liquid fuel pumping apparatus for internal combustion engines - Google Patents

Description

April 20, 1965 P. E. GLIKIN 3, 7 1

LIQUID FUEL PUMPING APPARATUS,FOR INTERNAL COMBUSTION ENGINES Filed Feb. 14, 1964 r 764 W 2 t 1 22b /63 2 Claims. (Cl. 123-139) This invention relates to liquid fuel pumping apparatus for internal combustion engines, and of the kind comprising in combination a rotary distributor adapted to be driven by the engine, a head at one end of the distributor said head having therein a bore, at least one plunger in the bore, a feed pump for feeding fuel intermittently as the distributor rotates, at a pressure dependent on the speed of the engine, to the bore in the head so as to move the plunger outwardly, a metering valve for controlling the supply of fuel from the feed pump to the bore, a cam for imparting inward movement to the plunger as the head rotates, and thereby deliver fuel through the distributor to the engine cylinders in turn and a fluid operable piston contained in a timing cylinder and for imparting angular movements to the cam to vary the timing of the delivery of fuel to the engine.

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

According to the invention a liquid fuel pumping apparatus of the kind specified is characterised in that one end of the timing cylinder is connected to a point downstream of a restriction disposed intermediate the feed pump and the metering valve, only during the time when fuel is being supplied to the bore, so that the pressure of fuel applied to the cylinder is dependent upon the rate of flow of fuel through the metering valve and therefore upon the speed of, and load on, the engine with which the apparatus is associated.

in the accompanying drawings:

FIGURE 1 is a sectional side elevation of one example of a liquid fuel pumping apparatus in accordance with the invention,

FIGURE 2 is a section on the line 2-2 of FIGURE 1,

FIGURE 3 is a section on the line 3-3 of FIGURE 1 and FIGURE 4 is a view similar to FIGURE 2 showing a modification.

Referring to the drawings there is provided a body part 1 in which is mounted a rotary distributor 2 adapted to be driven in timed relationship with the engine with which the pumping apparatus is associated. Formed on one end of the distributor is a head 3 having therein a transverse bore 4 whilst on the other end of the distributor is mounted a feed pump 5, conveniently of the vane type, having a fuel inlet 6 and a fuel outlet '7 in the body part and arranged to deliver fuel at a pressure dependent on the speed of rotation thereof by means of a regulating valve interconnecting the inlet and the outlet. The regulating valve includes a spring loaded valve member 8 which, as shown in FIGURE 1, is able to close a passage 8* interconnecting the outlet 7 and inlet 6 of the feed pump. As the flow through the passage 3* increases (as the speed of rotation of the feed pump 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 S even when the engine is being cranked for starting purposes. Within the transverse bore is a pair of plungers 9 and piston.

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fuel is fed to the space between the plungers, to move the latter outwardly, through a longitudinal. passage 14) in the distributor. Fuel is fed to this passage, through one of four equi-angularly spaced radial inlet passages 11 which at their inner ends are in communication with the longitudinal passage 10 and which at their outer ends, register in turn as the distributor rotates with an inlet port 12 in the body part. The inlet port 12 communicates with the outlet port 7 of the feed pump via a retricted orifice 13 contained in a longitudinal passage in the body part and a metering valve 14 arranged in series and the arrangement is such that when the inlet port 12 is in register with one of the inlet passages 11 a controlled quantity of fuel will be delivered to the transverse bore 4 to move the plungers 9 outwardly. I

The plungers 9 are moved inwardly, during at least a portion of the time when the inlet port 12 is out of register with one of the inlet passages 11, by the action of an annular cam 15, surrounding the head 3, and the lobes of which act on the plungers through a pair of rollers 16 disposed between the plungers 9 and the cam 15 respectively. The fuel displaced from the transverse bore by the plungers is delivered via the longitudinal passage 10 to a radial delivery passage 17 which registers in turn, as the distributor rotates, with one of four equi-angularly spaced delivery ports 18 in communication with the cylinders of the engine respectively.

In order to vary the timing of injection of fuel into the engine cylinders the annular cam is angularly movable by a fluid operable spring loaded piston 19 which is contained within a cylinder 20 the axis of which is parallel to a tangent to the annular cam 15. Fluid pressure is applied to the end of the cylinder 20 remote from the spring only during the time when fuel is being delivered to the transverse bore, this being achieved through one of four equi-angularly spaced recesses 21 formed in the periphery of the distributor which communicate with a point intermediate the orifice 13 and the metering valve 14 and which are arranged to register in turn with a port 22 which is in communication through conduit 22 with said end of the cylinder. The arrangement is such that the locked off quantity of fuel in the cylinder 20 will resist the torque applied to the annular cam 15 by the plungers 9. Moreover since the flow through the orifice 13, and hence the pressure downstream thereof, is determined by the setting of the metering valve 14, the timing of the injection will be determined by the load on, and the speed of, the engine. The load on an engine at a steady speed is the same as the torque developed by the engine and it is known that in normal operating conditions the rate at which fuel is delivered to an engine is roughly proportional to the torque developed by the engine.

In a modification, illustrated in FIGURE 4 of the drawings, the piston 23 which moves the cam 15 is of stepped form and is mounted in a stepped cylinder 24 the narrower end of which contains the spring acting on the The wider end of the cylinder is intermittently supplied with fuel by way of the port 22 and conduit 22*, and the narrower end of the cylinder is supplied with fuel from a point upstream of the orifice 13 through conduit 22*. By this means the effect of speed, as compared to the effect of load, on the amount of movement imparted to the cam is reduced.

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 internal combustion engines and comprising, in combination, a body part, a rotary distributor adapted to be driven in timed relationship to an engine with which the apparatus is associated, a bore defined in the distributor, a plunger slidable in said bore, a delivery passage in the distributor, a plurality of outlet ports in the body part s; 7 arranged to be in communication with the engine cylinders respectively, and with which the delivery passage registers in turn, a cam for imparting inward movements to the plunger as the distributor rotates, said inward movement of the plunger taking place whilst the delivery passage is in communication with an outlet port, a feed pump mounted in the body part and arranged to'be driven by the distributor, said feed pump having an inlet and an outlet, a relief valve for controlling the output pressure of the feed pump in a manner such that the pressure is dependent upon the speedof rotation or" the distributor, a'plurality of inlet passages formed in the distributor and communicating with said bore, an inlet port in the body part and with which the inlet passages register in turn as the distributor rotates, passage means in the body part serving to interconnect the output of the feed pump with said inlet port, said inlet port being arranged to register with an inlet passage so as to allow fuel to flow to the bore to move the plunger outwardly during the time when the delivery passage is out of register with an outlet port, a cylinder defined in the body part, a fluid operable piston mounted within the cylinder, means interconnecting the piston and said cam so that as the piston is moved the cam will be moved to vary the instant at which the plunger is moved inwardly, a metering valve mounted in said 7 passage means for controlling the quantity of fuel delivered by the feed pump to the bore, a restriction located in said passage means intermediate the feed pump outlet and the metering valve, conduit means interconnecting a point in said passage means intermediate the metering valve and the restriction with one end of said cylinder, resilient means accommodated in said cylinder for opposing the movement of the piston by the fuel pressure flowing through said conduit means, and rotary valve means for controlling the ilow of fuel through said conduit 2. Liquid fuelpumping apparatus for supplying fuel to internal combustion engines and comprising, in combination, a bodypart, a rotary distributor adapted to be driven in timed relationship to an engine with which the apparatus is associated, a bore defined in the distributor, a plunger slidable in said here, a delivery passage in the distributor, a plurality of outlet ports in the body part arranged to be in communication with the engine cylinders respectively, and with which the delivery passage registers in turn, a cam for imparting inward movements to the plunger as the distributor rotates, said inward movement or" the piunger taking place whilst the delivery passage is in communication with an outlet port, a feed pump mounted in the body part and arranged to be driven by the distributor, said feed pump having an inlet and an outlet, a relief valve for controlling the output pressure of the feed pump in a manner such that the pressure is dependent upon the speed of rotation of the distributor, a plurality of inlet passages formed in the distributor and commanicatinz with said bore, an inlet port in the body part and with which the inlet passages register in turn as the distributor rotates, passage means in the body part serving to interconnect the output of the feed pump with said inlet port, said inlet port being arranged to register with an inlet passage so as to allow fuel to flow to the bore to move the plunger outwardly during the time when the delivery passage is out of register with an outlet port, a stepped cylinder defined in the body'part, a stepped fluid operable piston occupying said stepped cylinder, means interconnecting said piston and the cam, so that as the piston is moved the cam will be moved to vary the instant at which the plunger is moved inwardly, a metering valve mounted in said passage means for controlling the quantity of fuel delivered by the feed pump to the bore, a restriction located in said passage means intermediate the feed pump outlet and the metering valve, first conduit means interconnecting a point in said passage means intermediate the metering valve and the restriction with the wider end of said cylinder, second conduit means interconnecting the outlet of the feed pump with the narrower end of said stepped cylinder, resilient means accommodatedwithin said stepped cylinder for opposing the movementof the stepped piston towards said narrower end of the cylinder, and rotary valve means for controlling the flow of fuel through said first conduit means.

FOREIGN PATENTS 10/57 Great Britain.

RICHARD B. WILKINSON, Primary Examiner.

Claims (1)

1. LIQUID FUEL PUMPING APPARATUS FOR SUPPLYING FUEL TO INTERNAL COMBUSTION ENGINES AND COMPRISING, IN COMBINATION, A BODY PART, A ROTARY DISTRIBUTOR ADAPTED TO BE DRIVEN IN TIMED RELATIONSHIP TO AN ENGINE WITH WHICH THE APPARATUS IS ASSOCIATED, A BORE DEFINED IN THE DISTRIBUTOR, A PLUNGER SLIDABLE IN SAID BORE, A DELIVERY PASSAGE IN THE DISTRIBUTOR, A PLURALITY OF OUTLET PORTS IN THE BODY PART ARRANGED TO BE IN COMMUNICATION WITH THE ENGINE CYLINDERS RESPECTIVELY, AND WITH WHICH THE DELIVERY PASSAGE REGISTERS IN TURN, A CAM FOR IMPARTING INWARD MOVEMENTS TO THE PLUNGER AS THE DISTRIBUTOR ROTATES, SAID INWARD MOVEMENT OF THE PLUNGER TAKING PLACE WHILST THE DELIVERY PASSAGE IS IN COMMUNICATION WITH AN OUTLET PORT, A FEED PUMP MOUNTED IN THE BODY PART AND ARRANGED TO BE DRIVEN BY THE DISTRIBUTOR, SAID FEED PUMP HAVING AN INLET AND AN OUTLET, A RELIEF VALVE FOR CONTROLLING THE OUTPUT PRESSURE OF THE FEED PUMP IN A MANNER SUCH THAT THE PRESSURE IS DEPENDENT UPON THE SPEED OF ROTATION OF THE DISTRIBUTOR, A PLURALITY OF INLET PASSAGES FORMED IN THE DISTRIBUTOR AND COMMUNICATING WITH SAID BORE, AN INLET PORT IN THE BODY PART AND WITH WHICH THE INLET PASSAGES REGISTER IN TURN AS THE DISTRIBUTOR ROTATES, PASSAGE MEANS IN THE BODY PART SERVING TO INTERCONNECT THE OUTPUT OF THE FEED PUMP WITH SAID INLET PORT, SAID INLET PORT BEING ARRANGED TO REGISTER

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