Distributor type fuel injection pump

Abstract

A fuel injection pump having a fixed pump body with a pumping chamber having a plurality of plunger bores, a plunger mounted in each plunger bore for reciprocation, a cam rotatable for reciprocating the plungers to periodically supply an intake charge of fuel to the pumping chamber and deliver a high pressure charge of fuel from the pumping chamber for fuel injection and to sequentially position the plungers in distributor valve positions thereof to deliver the high pressure charges of fuel, via distributor ports in the plunger bores, to a plurality of distributor outlets. In one version of the pump, the plunger bores are angularly spaced about and extend radially inwardly to a central coaxial bore, the rotary cam is an annular cam which actuates the plungers inwardly to deliver the high pressure charges of fuel, and a poppet valve is mounted in the central coaxial bore to supply fuel to and spill fuel from the pumping chamber. A pressure regulator has a fuel inlet opening in axial alignment with the poppet valve and which is closed by the poppet valve in its open position to increase the rate of fuel supply to the pumping chamber.

I claim: 
     
       1. In a fuel injection pump having a pump body with a pumping chamber with a plurality of plunger bores, a plunger mounted in each plunger bore for reciprocation.Iadd., with one end face of the plunger facing toward the pumping chamber, .Iaddend.rotary cam means rotatable about a cam axis for reciprocating the plungers to provide alternating intake and pumping phases of operation for respectively supplying an intake charge of fuel to the pumping chamber and delivering a charge of fuel from the pumping chamber at high pressure for fuel injection, valve means for supplying intake charges of fuel to the pumping chamber during the intake phases, a plurality of distributor outlets and a delivery system for delivering the high pressure charges of fuel from the pumping chamber to the distributor outlets; the improvement wherein a plurality of the plungers serve as distributor valves in sequence.Iadd., connecting the distributor outlets in sequence directly to the pumping chamber; .Iaddend.wherein the delivery system comprises a plurality of distributor ports for the plurality of distributor outlets respectively, each in a distributor valve bore, for connecting the bore to the respective distributor outlet; each distributor valve having a distributor position for each respective distributor port .[.for.]. .Iadd.and forming the sole means, in each distributor position thereof, .Iaddend.opening the distributor port .Iadd.to the pumping chamber adjacent said one end face of the distributor valve for connecting the respective distributor outlet directly to the pumping chamber .Iaddend.for delivering a high pressure charge of fuel from the pumping chamber.Iadd., .Iaddend.via the .Iadd.distributor valve bore and .Iaddend.distributor port.Iadd., directly .Iaddend.to the respective distributor outlet; wherein a plurality of the plungers serve as pumping plungers; and wherein the rotary cam means is operable during each pumping phase to actuate at least one pumping plunger to deliver a high pressure charge of fuel from the pumping chamber and to position one distributor valve in a distributor position thereof to distribute the high pressure charge of fuel to the respective distributor outlet. 
     
     
       2. A fuel injection pump according to claim 1 wherein the plunger bores are angularly spaced around .Iadd.and .Iaddend.have axes extending generally radially outwardly from the cam axis, and wherein the rotary cam means comprises annular cam means surrounding the plungers for actuating the pumping plungers radially inwardly during the pumping phases for delivering the high pressure charges of fuel. 
     
     
       3. A fuel injection pump according to claim 1 wherein the plunger bores are angularly spaced around and have axes extending generally radially outwardly from the cam axis, wherein the rotary cam means is mounted radially inwardly of the plungers for actuating the pumping plungers radially outwardly during the pumping phases for delivering the high pressure charges of fuel and wherein the pumping chamber in the pump body comprises a passage connecting the outer ends of the plunger bores. 
     
     
       4. A fuel injection pump according to claim 1, wherein all of the plungers serve as distributor valves in sequence and wherein during each pumping phase, all of the plungers except the acting distributor valve are actuated by the cam means for delivering a high pressure charge of fuel for fuel injection. 
     
     
       5. A fuel injection pump according to claim 2 wherein the pump body has a central coaxial valve bore .Iadd.between the inner ends of the plunger bores.Iaddend., wherein the plunger bores extend radially inwardly to the central valve bore, and wherein the valve means comprises a valve member .Iadd.mounted in the valve bore between the inner ends of the plunger bores and .Iaddend.axially shiftable in the valve bore between open and closed axial positions thereof. 
     
     
       6. A fuel injection pump according to claim 5 further comprising a fuel supply pump, a supply chamber connected to receive fuel continuously from the supply pump, a pressure regulator having a regulator chamber and operable for regulating the fuel pressure in said regulator chamber, and a pair of fuel passages connected in parallel between the supply chamber and regulator chamber, the valve member being operable in its open position to at least partly block one of said pair of passages downstream of said valve member to supply fuel via said one passage and the open valve member to the pumping chamber, the other of said passages being restricted to increase the flow through said one passage and the open valve member to the pumping chamber. 
     
     
       7. A fuel injection pump according to claim 5 further comprising a fuel supply pump, a supply chamber connected to receive fuel continuously from the supply pump, a pressure regulator having a regulator chamber and operable for regulating the fuel pressure in said regulator chamber, and fuel passage means connected between the supply chamber and regulator chamber, the valve member being operable in its open position to at least partly block said passage means downstream of the valve member to increase the rate of supply of fuel via the passage means and open valve member to the pump chamber. 
     
     
       8. A fuel injection pump according to claim 7 wherein said passage means comprises a passage opening downstream of and in alignment with the valve member and closed by the valve member in the open position thereof. 
     
     
       9. A fuel injection pump according to claim 5 wherein the plunger bores intersect at their inner ends to form ports in the pump body interconnecting the plunger bores. 
     
     
       10. A fuel injection pump according to claim 9 wherein the pumping chamber in the pump body is formed substantially entirely by the plunger bores. 
     
     
       11. A fuel injection pump according to claim 5 wherein the valve member is a poppet valve having a peripheral annulus for supplying fuel to and spilling fuel from the pumping chamber in the open position of the valve member, the peripheral annulus continuously overlapping at least some of the plunger bores as the valve member is axially shifted between its open and closed positions. 
     
     
       12. A fuel injection pump according to claim 5 wherein the valve means comprises an electromagnetic actuator having a stator in axial alignment with the valve member and an armature fixed to the valve member, the stator being operable when the electromagnetic actuator is energized to attract the armature .Iadd.and valve member .Iaddend.in one axial direction toward the stator to axially shift the valve member to one of its said positions and spring means operable for axially shifting the valve member in the opposite axial direction to its other position when the electromagnetic actuator is deenergized. 
     
     
       13. A fuel injection pump according to claim 12 wherein the .[.electromagnetic actuator.]..Iadd.armature .Iaddend.comprises .[.an.]. .Iadd.a transverse .Iaddend.armature plate .[.fixed to the valve member.]. and .Iadd.the stator comprises .Iaddend.an E-shaped stator core to attract the armature plate and .Iadd.plate and valve member .Iaddend.toward the stator core to axially shift the valve member to its said one position when the electromagnetic actuator is energized. 
     
     
       14. A fuel injection pump according to claim 1 wherein the delivery system comprises two axially spaced distributor ports in each distributor valve bore, wherein each distributor valve has two axially spaced distributor positions for the two respective distributor ports, and wherein the cam means is operable to position the distributor valves in the distributor positions thereof in sequence. 
     
     
       15. A fuel injection pump according to claim 2 wherein the pump body has a central, axially extending valve bore between the inner ends of the plunger bores, wherein the plunger bores extend radially inwardly to the central valve bore, and wherein the valve means comprises a valve member .Iadd.mounted in the valve bore between the plunger bores and .Iaddend.shiftable in the valve bore between open and closed positions thereof, the valve member in its open position being operable to supply fuel to the pumping chamber via the inner ends of at least some of the plunger bores. 
     
     
       16. A fuel injection pump according to claim 15 wherein the plunger bores are provided in two axially offset banks of alternating plunger bores and wherein the plunger bores of each bank intersect the adjacent plunger bores of the other bank at their inner radial ends to form a plurality of ports in the pump body interconnecting the plunger bores. 
     
     
       17. A fuel injection pump according to claim 1 wherein less than all of the plungers serve as distributor valves and all of the plungers serve as pumping plungers. 
     
     
       18. A fuel injection pump according to claim 1 wherein all of the plungers serve as both distributor valves and pumping plungers. 
     
     
       19. A fuel injection pump according to claim .[.5.]. .Iadd.2 .Iaddend.wherein the pump comprises a distributor head having a generally cylindrical bore .Iadd.coaxial with the rotary cam means, .Iaddend.wherein the pump body has an outer.Iadd., coaxial, .Iaddend.generally cylindrical surface received within the distributor head bore .Iadd.to provide a coaxial, generally cylindrical interface between the pump body and distributor head, .Iaddend.wherein the distributor outlets are provided in the distributor head angularly spaced around .Iadd.the generally cylindrical interface .Iaddend..[.the pump body.]., and wherein the .[.distributor.]. .Iadd.delivery .Iaddend.system comprises connecting bores in the pump body and distributor head connecting the distributor ports to the distributor outlets respectively .Iadd.across the generally cylindrical interface.Iaddend.. 
     
     
       20. A fuel injection pump according to claim 1 wherein each distributor valve has a peripheral annulus and an internal passage connecting the peripheral annulus to the pumping chamber .[.the peripheral annulus of.]. .Iadd.adjacent said one end face of the distributor valve.Iaddend., each distributor valve, in each distributor position thereof, opening the respective distributor port .Iadd.to the pumping chamber via the peripheral annulus and internal passage of the distributor valve for connecting the respective distributor outlet directly to the pumping chamber .Iaddend.for delivering a high pressure charge of fuel from the pumping chamber.Iadd., via the distributor valve bore, the internal passage and peripheral annulus of the distributor valve and the distributor port, directly .Iaddend.to the respective distributor outlet. 
     
     
       21. A fuel injection pump according to claim 4 wherein the cam means comprises at least one recessed cam section for sequentially positioning the distributor valves in their distributor positions. 
     
     
       22. A fuel injection pump according to claim 21 wherein the cam means comprises sloping cam sections, with the same slope, at opposite ends of said one recessed cam section. 
     
     
       23. A fuel injection pump according to claim 4 wherein the cam means comprises at least one raised cam section for sequentially positioning the distributor valves in their distributor positions. 
     
     
       24. In a fuel injection pump having a fixed pump body with a pumping chamber with a plurality of plunger bores angularly spaced around and having axes extending generally radially outwardly from a cam axis, a plunger mounted in each plunger bore for reciprocation.Iadd., with an inner end face of the plunger facing inwardly toward the pumping chamber.Iaddend., annular cam means surrounding the plungers and rotatable about the cam axis for reciprocating the plungers to provide alternating intake and pumping phases of operation for respectively supplying an intake charge of fuel to the pumping chamber and delivering a charge of fuel from the pumping chamber at high pressure for fuel injection, .Iadd.a .Iaddend.valve .[.means.]. .Iadd.member .Iaddend.selectively operable for supplying an intake charge of fuel to the pumping chamber during the intake phase and spilling fuel from the pumping chamber during the pumping phase, a plurality of distributor outlets and a delivery system for delivering the high pressure charges of fuel from the pumping chamber to the distributor outlets; the improvement wherein a plurality of the plungers serve as distributor valves in sequence.Iadd., connecting the distributor outlets in sequence directly to the pumping chamber.Iaddend.; wherein the delivery system comprises a plurality of distributor ports for the plurality of distributor outlets respectively, each in a distributor valve bore, for connecting the bore to the respective distributor outlet; each distributor valve having a distributor position for each respective distributor port .[.for.]. .Iadd.and forming the sole means, in each distributor position thereof, .Iaddend.opening the distributor port .Iadd.to the pumping chamber adjacent said inner end face of the distributor valve for connecting the respective distributor outlet directly to the pumping chamber .Iaddend.for delivering a high pressure charge of fuel from the .[.pump chamber.]. .Iadd.pumping chamber, .Iaddend.via the .Iadd.distributor valve bore and .Iaddend.distributor port.Iadd., directly .Iaddend.to the respective distributor outlet; wherein the annular cam means and plungers cooperate to distribute the high pressure charges of fuel .[.form.]. .Iadd.from .Iaddend.the pumping chamber via the .Iadd.distributor valve bores and the .Iaddend.distributor ports to the distributor outlets .Iadd.in sequence.Iaddend.; wherein the pump body has a central coaxial valve bore .Iadd.between the plunger bores.Iaddend., wherein the plunger bores extend radially inwardly to the central valve bore, wherein the plunger bores intersect at their inner ends to form ports in the pump body interconnecting the plunger bores, wherein the pumping chamber .Iadd.in the pump body .Iaddend.is formed substantially entirely by the plunger bores and wherein the valve .[.means comprises a.]. valve member .Iadd.is mounted in the valve bore between the inner ends of the plunger bores and is .Iaddend.axially shiftable in the valve bore between open and closed axial .[.position.]. .Iadd.positions .Iaddend.thereof. 
     
     
       25. A fuel injection pump according to claim 24 wherein the valve member is a poppet valve having a peripheral annulus for supplying fuel to and spilling fuel from the pumping chamber in the open position of the valve member, the peripheral annulus continuously overlapping at least some of the plunger bores as the valve member is axially shifted between its open and closed positions. 
     
     
       26. A fuel injection pump according to claim 24 further comprising a fuel supply pump, a supply chamber connected to receive fuel continuously from the supply pump, a pressure regulator having a regulator chamber and operable for regulating the fuel pressure in said regulator chamber, and fuel passage means connected between the supply chamber and regulator chamber, the valve member being operable in its open position to at least partly block said passage means downstream of the valve member to increase the rate of supply of fuel via the passage means and open valve member to the pumping chamber. 
     
     
       27. In a fuel injection pump having a pump body with a pumping chamber with a plurality of plunger bores angularly spaced around and having axes extending generally radially outwardly from a central axis, a plunger mounted in each plunger bore for reciprocation, annular cam means surrounding the plungers, the annular cam means and pump body being relatively rotatable about the central axis for reciprocating the plungers to provide alternating intake and pumping phases of operation for respectively supplying an intake charge of fuel to the pumping chamber and delivering a charge of fuel from the pumping chamber at high pressure for fuel injection, a plurality of distributor outlets and a system for delivering the high pressure charges of fuel from the pumping chamber to the distributor outlets, the pump body having a central coaxial bore providing a valve bore intersecting the angularly spaced plunger bores and an annular, coaxial valve seat between the intersection of the valve bore and plunger bores and one end of the central coaxial bore, a valve member having a sealing head at one end thereof and extending axially toward the other end of the central coaxial bore, the valve member being axially shiftable in the valve bore between a closed position thereof with its sealing head in engagement with the valve seat and an open position thereof with its sealing head spaced from the valve seat to form an annular valve opening therebetween, and valve actuating means for shifting the valve member between its open and closed .[.position.]. .Iadd.positions.Iaddend.; the improvement wherein the central coaxial bore is a throughbore, wherein the valve actuating means comprises an electromagnet having a transverse armature plate fixed to the valve member at the other end of the valve member from the sealing head and a stator contiguous to and in axial alignment with the armature plate, the stator being operable when the electromagnet is energized to attract the armature plate in one axial direction toward the stator to shift the valve member to one of its said positions and spring means biasing the valve member in the opposite axial direction to shift the valve member to its other position when the electromagnet is deenergized. 
     
     
       28. A fuel injection pump according to claim 27 wherein the valve member is a poppet type valve member engageable with the valve seat and axially shiftable away from the stator to its open position. 
     
     
       29. A fuel injection pump according to claim 28, further comprising abutment means, at said one end of the valve member, engageable by the valve member to establish the open position of the valve member. 
     
     
       30. A fuel injection pump according to claim 28 wherein the spring means biases the poppet valve member to its open position and wherein the stator, when the electromagnet is energized, attracts the armature plate to shift the poppet valve member against the bias of the spring means into engagement with the valve seat. 
     
     
       31. A fuel injection pump according to claim 27 wherein the fuel injection pump comprises a fuel chamber, with a regulated fuel pressure, in axial alignment with the valve member at said one end of the valve member, .[.wherein the valve inlet opening is in continuous communication with the fuel chamber,.]. wherein the valve member comprises a valve sleeve having said sealing head and a coaxial bore with an end opening at said one end of the valve member in continuous communication with said fuel chamber, wherein, in the open position of the valve member, the .[.sealing head is spaced from the valve seat to form an.]. annular .[.fuel passage therebetween connecting the pumping chamber via said axial.]. valve opening .Iadd.connects the pumping chamber .Iaddend.to said fuel chamber, and wherein the plurality of plunger bores intersect the valve bore between the ends of the coaxial bore in the valve sleeve. 
     
     
       32. In a fuel injection pump having a pump body with a pumping chamber with a plurality of plunger bores angularly spaced around and having axes extending generally radially outwardly from a central axis, a plunger mounted in each plunger bore for reciprocation, annular cam means surrounding the plungers, the annular cam means and pump body being relatively rotatable about the central axis for reciprocating the plungers to provide alternating intake and pumping phases of operation for respectively supplying an intake charge of fuel to the pumping chamber and delivering a charge of fuel from the pumping chamber at high pressure for fuel injection, a plurality of distributor outlets and a system for delivering the high pressure charges of fuel from the pumping chamber to the distributor outlets, the pump body having a central coaxial bore providing a valve bore intersecting the angularly spaced plunger bores and an annular, coaxial valve seat between the intersection of the valve bore and plunger bores and one end of the central coaxial bore, a valve member having a sealing head at one end thereof and extending axially toward the other end of the central coaxial bore, the valve member being axially shiftable in the valve bore between a closed position thereof with its sealing head in engagement with the valve seat and an open position thereof with its sealing head spaced from the valve seat to form an annular valve opening therebetween, and valve actuating means for shifting the valve member between its open and closed positions; the improvement wherein the central coaxial bore is a throughbore, wherein the fuel injection pump comprises a fuel chamber, with a regulated fuel pressure, in axial alignment with the valve member axially outwardly of said one end of the valve member, wherein the valve member has a coaxial bore with an end opening at said one end thereof in continuous communication with said fuel chamber, wherein said annular valve opening, with the valve member in is open position, connects the pumping chamber to said fuel chamber, and wherein the valve actuating means is mounted at the other end of the valve member from said sealing head. 
     
     
       33. In a fuel injection pump according to claim 32 wherein the valve actuating means comprises an electromagnet having a transverse armature plate fixed to the valve member at the other end of the valve member from the sealing head and a stator contiguous to and in axial alignment with the armature plate, the stator being operable when the electromagnet is energized to attract the armature plate in one axial direction toward the stator to shift the valve member to one of its said positions and spring means biasing the valve member in the opposite axial direction to shift the valve member to its other position when the electromagnet is deenergized.