| 摘要 |
A piezoelectric control valve (30) for a servo injector (10) has a piezoelectric actuator (32) which comprises an encapsulating tube (54) extending along a main axis (X) from a first extremity (56) to a second extremity closed by a closing member (58) and, a piezoelectric stack (76) axially compressed inside the encapsulating tube (54) between an upper extremity in contact with the inner face (60) of the closing member (58) and, a lower extremity in contact with a pusher member (78) adapted to cooperate with a valve member (36) in order to open or close a return orifice. The piezoelectric control valve (30) further comprises an adjusting member (64) adapted, in use, to permanently maintain a compression force (Fl) in the encapsulating tube (54) independently of the energizing state of the piezoelectric stack (76) and of the thermal expansion of the injector (10). |
