| 摘要 |
The invention relates to a fuel injector having an injector housing containing a pressure chamber from which highly pressurized fuel is injected into a combustion chamber of an internal combustion engine. A nozzle needle control chamber is provided in the housing such that a nozzle needle has its first end disposed in the nozzle needle control chamber. A second end of the nozzle needle lifts away from its seat as a function of the pressure in the nozzle needle control chamber. The pressure in the nozzle needle control chamber is controlled by a switching valve device which is equipped with a piezoelectric actuator that expands longitudinally when supplied with current. A valve piston is coupled to the piezoelectric actuator and has its free end of the disposed in a valve piston control chamber. The valve piston control chamber communicates with the nozzle needle control chamber. In the charged state of the piezoelectric actuator, the free end of the valve piston interrupts a hydraulic pressure-relief connection between the valve piston control chamber and a pressure-relief chamber.
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