Hydraulisch-betätigtes Kraftstoffeinspritzventil mit direkt gesteuerter Ventilnadel

An hydraulically actuated fuel injector (14') includes an injector body (105) having at least one actuation fluid inlet (106), a needle control chamber (118), a nozzle chamber (114), and a nozzle outlet (117) that opens to the nozzle chamber (114). A hydraulic means within the injector pressurizes fuel in the nozzle chamber (114). The hydraulic means includes an actuation fluid control valve having a first solenoid (131) and is moveable between an open position in which the actuation fluid inlet (106) is open and a closed position in which the actuation fluid inlet (106) is closed. A needle valve member (160) is positioned to reciprocate in the nozzle chamber (114) between an open position in which the nozzle outlet (117) is open and a closed position in which the nozzle outlet (117) is closed. A needle valve member (160) includes a closing hydraulic surface (167) exposed to pressure in the needle control chamber (118). A needle control valve having a second solenoid (130) is mounted within the injector body (105) and is moveable between an off position in which the needle control chamber (118) is opened to a source of high pressure fluid and an on position in which the needle control chamber (118) is opened to a low pressure passage.