| 摘要 |
PURPOSE:To realize a compact piezoelectric actuator by a method wherein more than one piezoelectric device is arranged concentrically in a multiple manner and the individual piezoelectric devices are coupled in series in an axial direction by using a coupling frame. CONSTITUTION:A second ring-shaped device and a third ring-shaped device 2, 3 which are arranged in succession concentrically at the outside of a first pillar-shaped device 1 are formed by laminating respective ring-shaped piezoelectric materials. The lower end of the first device 2 as well as the lower end of the second device 2 and the upper end of the third device 3 are coupled by using respective coupling frames 4, 5 in an axial direction to compress the respective piezoelectric materials; a reinforcing plate 6 is fixed to the lower end of the third device 3. Accordingly, if a voltage is impressed on the individual devices 1-3 and the devices 1-3 are elongated by X1-X3, an overall length L' after the impression of the voltage becomes L+X1+X2+X3 with reference to a reference position 7; if a length of the individual devices 1-3 is equal, X1=X2=X3=X and, therefore, L'=L+3X. By this setup, a compact piezoelectric actuator is realized. |
