Fuel injector for common-rail fuel injection system, has control piston guided in valve unit, which divides control chamber into multiple pressure chambers, where former pressure chamber is arranged between shaft end and control piston

摘要

The injector has a nozzle needle (4) guided displaceably to a shaft end, while a control chamber located at front side of the shaft end is limited by the nozzle needle and a valve unit (3). The connection of a drain line to a return line (7) is opened or closed through a control valve (2). A control piston is slidably guided in the valve unit, which divides the control chamber into multiple pressure chambers. The former pressure chamber is arranged between the shaft end and the control piston, and is in communication with an inlet throttle.