GB1404584A - Liquid fuel injection pumping apparatus for an internal combustion engine - Google Patents

Abstract

1404584 I C engine fuel supply, measuring valves CAV Ltd 6 Oct 1972 [15 Oct 1971] 48020/71 Heading F1B Fuel from an accumulator 10, supplied by a pump 9, e.g. engine driven, is fed to an outlet conduit 14 via valves 16, 17, 19, 20 and a cylinder 11 containing a shuttle 12. The valves are operated by a solenoid 25 and armature 26, the solenoid, when energized, permitting the valve member 19 to engage the seat 20 and causing the valve member 16 to move from its seat on the member 17. Fuel flows through the passage 22 in the member 17 to one end of the cylinder 11 and the shuttle 12 is moved against the bias of the spring 13 to deliver fuel to the conduit 14 and an injector 15. When the solenoid 25 is de-energized the valve member 16 closes the passage 22 and the valve member 19 is moved from the seat 20 to permit the shuttle 12 to be moved by the spring 13. The fuel delivery by the shuttle may be controlled by the time during which the solenoid is de-energized and thus the starting position of the shuttle. A piston 24 subject to accumulator pressure provides fuel pressure balancing of the valve member 16. The conduit 14 may be connected in turn to a plurality of injectors (31), Fig.2 (not shown). The effective delivery stroke of the shuttle (32), Fig.2, may be terminated by providing communication of the delivery end of the shuttle cylinder with the cylinder of a spring-biased pressure-relief piston (36) through a passage (33) in the shuttle. At a predetermined shuttle position the shuttle passage (33) allows fuel to flow into pressure-relief cylinder, the fuel being discharged from the cylinder to a drain through a groove (38) in the shuttle towards the end of a return stroke of the shuttle by the spring 13. An extension (39), Fig.2, of the valve member 19 is subject to accumulator pressure to provide fuel pressure balance of the member 17.