GB1190617A - Fuel Injection Pumps for Internal Combustion Engines. - Google Patents

Abstract

1,190,617. Fuel injection pump. ROBERT BOSCH G. m. b. H. June 27, 1967 [June 28, 1966], No.29489/67. Heading F1A. The quantity of fuel delivered by a fuel injection pump is regulated by a throttle in the inlet and injection is terminated by the opening of a spill passage which is also throttled, the resulting pressure being used to regulate the inlet throttle. A reciprocating and rotating piston 12 draws through an inlet passage 23 and delivers through a valve 27 and port 28 to a plurality of outputs 29 and subsequently spills through a radial bore 31 to a groove 30 and passage 32. The passages 23, 32 are intersected by a throttle valve 34, the passage 32 communicating with the under side of the throttle valve to control its position against an adjustable spring 35. The throttle valve is also axially adjustable by means of a lever 40. The spill passage throttle portion of the throttle valve may be such that change of the throttle area is only made by rotating the throttle valve. A valve 49 closes the spill passage 32 when the pressure from the feed pump 7, which is regulated by the valve 22, is low i.e. on starting up, the provide excess fuel. The drive cam is angularly adjustable by means of a piston 9 subjected to the feed pump pressure and the pressure on the piston may be regulated by a further edge on the throttle valve 34. Movement of the valve 34 is damped by a throttle 47. The quantity spilled is negotiated by axial adjustment of the cylinder 14 by means of screw 18.