Fuel injector with direct needle control for an internal combustion engine

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;
• a booster chamber in the form of 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.