GB1198798A - Liquid Fuel Injection Pump Apparatus - Google Patents

Abstract

1,198,798. Fuel injection pumps. C.A.V. Ltd. Oct. 9, 1967 [Oct. 21, 1966], No.47246/66. Heading F1A. In a radial cylinder rotary distributer type fuel injection pump inward movement of the pistons 13 causes liquid to move a valve 21 to the right against the action of a spring 22 and so cause displacement of liquid from the spring chamber to an outlet port 19 which at this time is in alignment with one of the outlet passages 20. Further movement of the valve connects the pump cylinder through longitudinal and cross bores in the valve to the spring chamber and outlet port 19. The end of the discharge stroke is followed by a slight retraction of the pistons 13 so that the valve 21 moves to the left relieving the pressure in the outlet passages; this period of retraction is followed by a dwell during which the cylinder and valve bore are connected both to the inlet port 26 leading through a governor controlled throttle to the outlet of the feed pump, and to a drain passage 30 at low pressure. The drain passage then closes followed by closure of the delivery passage 20 and outward movement of the pistons 13. The pressure in the spring chamber and outlet port 19 is then adjusted by one of the ports 32 which comes into communication with a port 33 leading to the feed pump outlet passage 15. The delivery in relation to speed is adjusted by means of a spring loaded piston 41 in a chamber 40 which is brought into communication with the spring chamber and outlet port 19 by means of a port 46 with which one of the ports 32 communicates when outlet port 19 connects with an outlet passage 20. Movement of the piston 41 is limited by a stop, the position of which is adjusted in accordance with feed pump outlet pressure which is speed sensitive. Subsequently the chamber 41 returns liquid to the spring chamber through a port 46. The pump cam ring may be angularly-adjustable to vary timing.