Fuel pump having plunger and fuel supply system using the same

摘要

A delivery valve (80) is connected to a discharge passage (230), through which fuel in a compression chamber (220) is discharged. The delivery valve (80) is screwed to a mount hole (22) formed in the cylinder (12). A communication passage (240) is formed in a body (82) to extend through the sidewall between a screwed part, in which the mount hole (22) and the body (82) are screwed to each other, and a gasket (88). A small clearance (242) is formed between an inner peripheral surface (23) of the mount hole (22) and an outer peripheral surface (83) of the body (82). The communication passage (240) provides communication between a fuel passage (232) downstream of a valve seat member (87) and the clearance (242). The clearance (242) communicates with the suction chamber (210) through a return passage (240, 270, 290) formed in the cylinder (12).