Patent ID: 7258283

Claim:
A fuel injector for an internal combustion engine, the injector comprising a nozzle needle that is guided in a nozzle body and acts on a nozzle needle sealing seat, an actuator, a hydraulic booster equipped with an actuator booster piston connected to the actuator and a nozzle needle booster piston connected to the nozzle needle; the actuator booster piston and the nozzle needle booster piston act on at least one booster chamber; said at least one booster chamber including an actuator coupler chamber associated with a pressure surface of the actuator booster piston; the nozzle needle being lifted away from the nozzle needle sealing seat, depending on the pressure in the actuator coupler chamber, thus initiating the injection of highly pressurized fuel, in addition to the actuator booster piston, a control element is provided that is able to execute a stroke motion, the control element being hydraulically coupled to the actuator coupler chamber by means of a first control surface, and being associated with a control chamber by means of a second control surface; and a second actuator surface on the actuator booster piston which, as an additional control surface, is associated with the control chamber.