Patent ID: 7201149

Claim:
A fuel injector ( 3 ) for injecting fuel into the combustion chambers of an internal combustion engine, the fuel injector comprising an injection valve member ( 18 ) and a pressure booster ( 5 ) that has a working chamber ( 8 ), which is continuously connected to a common rail ( 1 ) and is separated from a differential pressure chamber ( 9 ) by a piston part ( 6 , 13 ), it being possible to either depressurize or pressurize the differential pressure chamber ( 9 ) of the pressure booster ( 5 ) by means of a valve ( 30 ), and a valve ( 30 ) operable to depressurize or pressurize the differential pressure chamber ( 9 ) of the pressure booster ( 5 ) and to control the injection valve member ( 18 ), the valve ( 30 ) having a control valve ( 32 ), which is equipped with a servo valve piston ( 35 ), and an actuator-triggered multistage actuating valve ( 31 ), wherein, in an intermediate position of a valve member ( 51 ) of the actuating valve ( 31 ), when an actuator ( 60 ) is supplied with a first current level ( 71 ), a throttle restriction ( 56 ) functioning as an outlet throttle is opened in order to depressurize the pressure chamber ( 39 ) of the control valve ( 32 ), and an additional throttle restriction ( 55 ), which is parallel to the throttle restriction ( 56 ), remains closed.