摘要 |
A piezoelectric actuator, comprising an electrostrictive effect element, a metal case and a metal member, each of the metal case and the metal member being provided with a flanged mounting portion on the periphery thereof, either of the metal case or the metal member being provided with an expansion and contraction portion. The element is received in the metal case and is hermetically sealed in such a state that a compressive force is previously applied to the element.
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