초록 ▼

A piezoelectric actuator for moving an object member by utilizing a volume change of a piezoelectric element. The piezoelectric actuator includes a piezoelectric element, an envelope having a bellows or the like at least as a part of the wall, and a pressure chamber in which work oil is hermetically

A piezoelectric actuator for moving an object member by utilizing a volume change of a piezoelectric element. The piezoelectric actuator includes a piezoelectric element, an envelope having a bellows or the like at least as a part of the wall, and a pressure chamber in which work oil is hermetically enclosed. Resiliency of the bellows or the like prevents breakdown of the piezoelectric element due to the supply of biased counter force, and highly improved sealing performance of the pressure chamber prevents leakage of the control oil.

대표청구항 ▼

A piezoelectric actuator for moving an object member by utilizing a dimensional change of a piezoelectric element, comprising an envelope between the piezoelectric element and the object member, said envelope comprising a cylinder having a bellows in a side wall of the cylinder, one end of the cylin

A piezoelectric actuator for moving an object member by utilizing a dimensional change of a piezoelectric element, comprising an envelope between the piezoelectric element and the object member, said envelope comprising a cylinder having a bellows in a side wall of the cylinder, one end of the cylinder being abutted on the piezoelectric element and the other end of the cylinder being closed by a cap member having a hole, said object member being slidably disposed in said hole, and said envelope hermetically containing a fluid, wherein said cylinder is contracted or expanded responsive to a dimensional increase or decrease in the piezoelectric element.