INJECTION FUEL PRESSURE INTENSIFIER

摘要

An injected fuel pressure boosting device (7) provided with a large diameter piston (18), a medium diameter piston (19), and a small diameter piston (20). A high pressure chamber (22) filled at high pressure at all times is formed at the outer end of the medium diameter piston (19), while a pressure boosting chamber (23) is formed at the outer end of the small diameter piston (20). A pressure control chamber (24) is formed on the end face of the large diameter piston (18) on the small diameter piston (20) side. When high pressure fuel is supplied to the pressure control chamber (24), the large diameter piston (18) moves to the medium diameter piston (19) side, that is, the pressure boosting preparation position. At this time, the leaked fuel outflow port (33) is closed by the end face of the large diameter piston (18).