Actuator for i.c. engine fuel injection valve has piezoelectric or magnetostrictive element provided with tensioning device fitting through its centre or around its outside

摘要

The actuator (1) has a piezoelectric or magnetostrictive element (14) with a number of stacked layers (2) and an associated tensioning device (12), fitting through the centre or around the outside of the piezoelectric or magnetostrictive element, for providing an axial bias force.