Patent ID: 7418949

Claim:
A common rail injector comprising an injector housing, a control chamber, a nozzle needle, a fuel inlet connected to a central high-pressure fuel source outside the injector housing and to a pressure chamber inside the injector housing, from which pressure chamber, depending on the pressure in the control chamber, highly pressurized fuel is injected into a combustion chamber of an internal combustion engine upon the nozzle needle lifting away from a sealing seat, a piezoelectric actuator controlling the pressure in the control chamber in a direct, inverse fashion, and a coupler sleeve having a nozzle needle guide section and an actuator guide section, an end of the actuator disposed toward the combustion chamber being guided in an actuator guide section end of the coupler sleeve, an end of the nozzle needle oriented away from the combustion chamber being guided in a nozzle needle guide section end of the coupler sleeve, wherein an inner diameter of the actuator guide section end is larger than an inner diameter of the nozzle needle guide section end, wherein the actuator guide section end is supported in an axial direction against a shoulder of the injector housing, and wherein the injector housing is embodied by a nozzle body disposed on an injector body, the nozzle body encompassing the nozzle needle and guiding the nozzle needle therein and the injector body encompassing the actuator.