| 摘要 |
PROBLEM TO BE SOLVED: To provide a piezoelectric type three-axle acceleration sensor capable of setting optionally the magnitude of a Z-axis acceleration signal without using a signal amplification circuit. SOLUTION: In this acceleration sensor, board extension parts 13D, 13E extending to the outside of a base 5, and a diaphragm extension part 1b are installed on a piezoelectric ceramics board 9a and a diaphragm 1 respectively, and an additional deadweight 7 is installed on the outside end part on the back of the diaphragm extension part 1b. One-side electrodes DZ1, DZ3 between two pairs of Z-axis acceleration detection electrodes DZ1, DZ2 and DZ3, DZ4 are arranged adjacently to the base 5 and other-side electrodes DZ2, DZ4 are arranged adjacently to the additional deadweight 7. Each part of the piezoelectric ceramics board 9a corresponding to each electrode DZ1-DZ4 is polarized at the time when the same kind of stress is generated on each part, so that spontaneously-polarized charges having reverse polarities will be generated on the one-side electrodes DZ1, DZ3 and the other-side electrodes DZ2, DZ4. |
