High-pressure fuel supply pump

摘要

A high-pressure fuel supply pump with high performance is capable of securely preventing a cylinder section from seizing up and also permits improved sealing performance to minimize the chance of fuel leakage. The high-pressure fuel supply pump has: a casing (48) having a cylindrical cavity (48a); a sleeve (40) which has a cylinder section (40a) and a fixing section (40c), one end thereof closer to the fixing section (40c) being abutted against the bottom of the cavity (48a); and a piston (53) which is disposed in the cylinder section (40a). The high-pressure fuel supply pump takes in fuel through an intake passage (36) by the reciprocation of the piston (53) into a fuel pressurizing chamber (52) to pressurize it, then discharges the pressurized fuel through a discharge passage (37) to forcibly feed it into a fuel injector of a cylinder injection engine. A cylindrical slit (40d) is provided between the cylinder section (40a) and the fixing section (40c) of the sleeve (40), and the fixing section (40c) is secured by being fastened toward the bottom of a cavity (48a) by a cylindrical fastening member (64) screwed to the cavity (48a).