Multi-layer piezoelectric element, and piezoelectric actuator, injection device, and fuel injection system provided with same

Abstract

There are provided a multi-layer piezoelectric element which is capable of suppression of occurrence of an imperfect area, suffers from no development of leakage current even with moisture intrusion, has long-term freedom from variations in displacement and can achieve stable driving, as well as to provide a piezoelectric actuator, an injection device, and a fuel injection system provided with the multi-layer piezoelectric element. A multi-layer piezoelectric element includes a stacked body in which piezoelectric layers and internal electrodes acting as positive and negative internal electrodes are laminated; an inorganic coating attached to a side surface of the stacked body where ends of both the positive internal electrodes and the negative internal electrodes are exposed; and metal particles composed predominantly of a metal element contained in the internal electrodes, the metal particles dispersed in the inorganic coating.