PIEZO-ACTUATOR

PURPOSE:To realize a piezo-actuator free from a leakage of liquid and excellent in handling properties, safety, and maintainability. CONSTITUTION:A displacement magnifying rubber 4 provided with a recessed part 4a located at its upper center and provided to the upside of a piezo-device 3, a displacement magnifying part 2 provided onto the displacement magnifying rubber 4 enveloping it, and a pushing rod 7 which is inserted into the recessed part 4a of the displacement magnifying rubber 4 penetrating through the upper part of the displacement magnifying part 2 are provided. The displacement of the piezo-device 3 is magnified and transmitted through the pushing rod 7, wherein a rubber is used as an operating medium in place of operating fluid, so that a sealing mechanism which prevents liquid from leaking out of a device can be dispensed with, and a piezo-actuator which is remarkably simplified in structure, lessened in size and weight, and improved in handling properties, maintainability, and safety, and accurate in displacemetn can be realized.