MULTI-LAYER PIEZOELECTRIC ELEMENT AND INJECTION APPARATUS EMPLOYING THE SAME

摘要

A multi-layer piezoelectric element includes a stack having metal layers and piezoelectric layers stacked one on another, and a pair of external electrodes formed on the side faces of the stack. At least one of the metal layers is a stress relieving layer having partial metal layers scattered between the two piezoelectric layers and voids. Junction sections are formed between the two piezoelectric layers to join and are disposed on both sides of an imaginary straight line drawn to connect the center of width of one of the external electrodes and the center of width of the other of the external electrodes in a plane including the stress relieving perpendicular to the stacking direction.