Rotary distributor type fuel injection pump

In a fuel injection pump having a pump rotor with a pumping chamber at one end thereof and a distributor rotor at the other end thereof, the pumping chamber being provided by an annular arrangement of pumping plunger bores with axes extending generally radially outwardly from the axis of rotation of the pump rotor, a pumping plunger mounted in each pumping plunger bore for reciprocation, annular cam means surrounding the annular arrangement of pumping plunger bores for reciprocating the pumping plungers to provide alternating intake and pumping strokes thereof for respectively supplying intake charges of fuel to the pumping chamber and delivering high pressure charges of fuel from the pumping chamber for fuel injection, a distributor head having a plurality of distributor outlets, the distributor rotor being rotatably mounted within the distributor head for delivering the high pressure charges of fuel to the distributor outlets;

• the improvement wherein the pump rotor has a central coaxial throughbore providing a valve bore intersecting the annular arrangement of plunger bores, an annular, coaxial valve seat around the rotor throughbore between one end thereof away from the distributor rotor and the intersection of the valve bore and annular arrangement of plunger bores, a valve member having a sealing head at one end thereof engageable with the annular valve seat and extending axially from the sealing head toward the other end of the rotor throughbore, the valve member having an intermediate land in sealing engagement with the pump rotor to seal the pumping chamber from said other end of the rotor throughbore, a fuel supply chamber with a regulated fuel pressure connected to said one end of the rotor throughbore, 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 interconnecting said fuel supply chamber and the pumping chamber, valve actuating means at the other end of the valve member from the sealing head for selectively shifting the valve member between its open and closed positions.

In a fuel injection pump having a pump rotor with a pumping chamber at one end thereof and a distributor rotor at the other end thereof, the pumping chamber being provided by an annular arrangement of pumping plunger bores with axes extending generally radially outwardly from the axis of rotation of the rotor, a pumping plunger mounted in each pumping plunger bore for reciprocation, annular cam means surrounding the annular arrangement of pumping plunger bores for reciprocating the pumping plungers to provide alternating intake and pumping strokes thereof for respectively supplying intake charges of fuel to the pumping chamber and delivering high pressure charges of fuel from the pumping chamber for fuel injection, a distributor head having a plurality of distributor outlets, the distributor rotor being rotatably mounted within the distributor head for delivering the high pressure charges of fuel to the distributor outlets;

• the improvement wherein the pump rotor has a central coaxial throughbore providing a valve bore intersecting the annular arrangement of plunger bores, an annular, coaxial valve seat around the rotor throughbore between one end thereof away from the distributor rotor and the intersection of the valve bore and the annular arrangement of plunger bores, a valve member having a sealing head at one end thereof engageable with the annular valve seat and extending axially from the sealing head toward the other end of the rotor throughbore, the valve member having an intermediate land in sealing engagement with the pump rotor to seal the pumping chamber from said other end of the rotor throughbore, a fuel supply chamber connected to said one end of the rotor throughbore, a pressure regulator connected to said fuel supply chamber to regulate the pressure therein, 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 interconnecting said fuel supply chamber and the pumping chamber, valve actuating means for selectively shifting the valve member between its open and closed positions, the valve member having a coaxial bore with an end opening at said one end thereof in continuous communication with the fuel supply chamber, a fuel supply pump, and a fuel system for conducting fuel from the fuel supply pump to said fuel supply chamber via said coaxial bore in the valve member.