GB997414A - Liquid fuel pumps - Google Patents

Abstract

997,414. Fuel injection pumps. C.A.V. Ltd. April 5, 1962 [April 25, 1961], No. 14867/61. Heading F1A. [Also in Division G3P]. A liquid fuel pump has a rotary distributer 9 driven by the engine, a head 8 at one end of the distributer with a transversely extending bore 10, at least one plunger 11 in the bore, means such as passages 7, 14 for feeding fuel intermittently to the bore, an annular cam 13 surrounding the head to impart inward movement to the plunger as the head rotates and thereby deliver fuel through the distributer to the engine cylinder in turn, a fluid operable piston 19, a cylindrical valve member 21, a compression spring 22 between the piston and valve member, a supply passage 23 through which fuel at a pressure at least in part dependent upon the speed of the engine can enter one end of a chamber 18 to act on the valve member, a further passage 24 controlled by the valve member whereby the other end of the chamber can be placed in communication with a source of liquid under pressure and with exhaust when the pressure in the supply passage rises and falls, respectively. The supply passage 23 is connected to the outlet of a feed pump 5 having its outlet and inlet connected by a relief valve which regulates the delivery pressure in accordance with speed. With increasing speed, the valve member 21 is displaced to the left allowing fluid from passage 23 to flow through a bore 27 and a non-return valve 28 to the passage 24 and displace the piston 19 to the right, the spring 22 returning the valve member to its original position. The spring also moves the valve member to the right when the speed decreases to connect the space at the left of the piston 19 to exhaust through a port 22. Fuel is discharged to the engine cylinders in turn through the ports 16, 17. In a modification, fluid for actuating the piston 19 is supplied through a non-return valve from the oil pump of the engine.