FUEL INJECTION DEVICE

摘要

A check valve (8) and a booster (9) are inserted in parallel in a supplied fuel line (6) connecting a common rail (5) and an injection valve (7), a piston (10E) of a hydraulic circuit (10) is driven for positioning by a piezoelectric actuator (PA-1), the pressures in a chamber (9Db) of the booster( 9) and the pressure in a fuel chamber (7G) of the injection valve (7) are selectively lowered by controlling the alignment state between ports (10Eb), (10Ec) provided in the piston (10E) to communicate with a low-pressure portion and an opening 10Aa of a first chamber 10A and an opening (10Ba) of a second chamber (10B) of cylinder (10C), whereby the pressure of the fuel supplied to the fuel reservoir (7B) of the injection valve (7) is rapidly switched to one or the other of high-pressure fuel from the common rail (5) and pressure-boosted high-pressure fuel from the booster (9).