PIEZOELECTRIC ELEMENT FOR INJECTOR

摘要

PROBLEM TO BE SOLVED: To provide a piezoelectric element usable for a long time and having excellent durability when used in an injector. SOLUTION: The piezoelectric element 1 is built into the injector and generates driving force for the injector. When a coercive electric field of the piezoelectric element 1 is Ec with a preset load of 500 N applied to the piezoelectric element, d(0.1 Ec)/d(1.2 Ec)>0.43 holds as a relationship between an apparent piezoelectric constant d(1.2 Ec) calculated from a static elongation obtained when an electric field of 1.2 Ec is applied in the same direction as a direction of polarization and an apparent piezoelectric constant d(0.1 Ec) calculated from a static elongation obtained when an electric field of 0.1 Ec is applied in the same direction as the direction of polarization.