GB870664A - Liquid fuel pumps for internal combustion engines - Google Patents

Abstract

870,664. Fuel injection pumps. C. A. V. Ltd. Sept. 11, 1959 [Sept. 25, 1958], No. 30634/58. Class 102(1). A fuel injection pump of the type comprising pump pistons 15, Fig. 1, in a rotary head 13 which is combined with a distributer 11. A feed pump 12 supplies fuel through passage 21, ports 22 and radial passages 23 to the pump chamber 14 and the fuel is delivered through a radial passage 19 to the passages 20 in turn leading to the engine cylinders. During each injection stroke of the pump one of the passages 23 communicates with a passage 25 leading to a cylinder 24 which houses a piston member 26 which is moved by the fuel to abut a stop 27. During each suction stroke a groove 29 in the distributer provides communication between the passage 25 and spill passage 30 and the piston is moved by a spring 28 to cause escape of fuel in the cylinder 24 through the passage 30, an axial passage in the piston and a radial port 33 until this port is closed by a sleeve 34. The position of the sleeve may be adjusted manually or automatically and its position determines the amount of return movement of the piston and hence the amount of fuel needed to move this piston against the stop on the subsequent injection stroke which thus determines the quantity of fuel delivered to the engine cylinders. In a modification shown in Fig. 3 the piston 26 is formed with a helical end which determines the end of the return stroke by the closing of the spill passage 30. The return movement of the piston is caused by fuel from the feed pump 12 acting on the left hand end of the piston.