Variable-delivery high-pressure fuel pump

摘要

Disclosed a variable-delivery high-pressure fuel pump of pre-stroke control system with a small-sized control valve. According to the variable-delivery high-pressure fuel pump, an inlet port valve to intermittently allow and block the inflow of fuel into a pump chamber is controlled by a hydraulic action of a low-pressure fuel in a control chamber, which is opened and closed with a control valve. The inlet port valve (30) to control the admission of the fuel into the pump chamber(16) forms on its own top end in a bore(44) inside a valve cap(42). The control valve(50) of a solenoid-actuated valve makes open and block a fluid communication to the control chamber(45). Where control valve(50) is left open even during a pump plunger(10) is moving upwardly, the fuel in the pump chamber(16) is allowed to flow backwards through the still-opened inlet port valve(30). A metered amount of fuel to be delivered through a delivery valve(15) may be regulated in the pump chamber(16).