| 摘要 |
PURPOSE:To eliminate a crack or a damage due to a stress concentration by inverting the polarity in the vicinity of the end that a displacement becomes maximum with respect to the polarity in the vicinity of a support. CONSTITUTION:Two ring-shaped piezoelectric elements 6, 7 are bonded so that the polarizing directions become the same to form a parallel bimorphs 8, and electrodes are formed at both surfaces of the elements 6, 7. When the inner diameter of the element 6 is represented by (d), the polarities of the l portion (l=1/3d-d) and the end l1 portions of both except the l portion are reverse. The intermediate electrodes 13, 13' of the elements 6, 7 are divided, the bimorphs 8 is supported by supports 15, 15' at the dividing positions 14, 14', thereby forming two cantilever beams. |
