Injector for fuel injection system of internal-combustion engine, has piezo-electric actuator formed as pipe and radially limiting coupling space in its interior in area of its actuator bases

摘要

The injector (1) has a nozzle needle (6) stroke adjustably supported at an injector body (2) for controlling injection of fuel through a spray hole (7). A piezo-electric actuator (11) controls pressure in a coupling space (13). The nozzle needle exhibits a control surface that limits a control space, which is hydraulically coupled with the coupling space. The piezo-electric actuator is formed as a pipe and radially limits the coupling space in its interior (21) in the area of its actuator bases (22).