| 摘要 |
PURPOSE:To detect acceleration in two orthogonal axes of X and Y by one sensor having a simple structure, by a method wherein a piezoelectric ceramic ring is subjected to a polarization processing by two terminals which connect band electrodes provided at positions dividing the outer peripheral surface of the ring equally by 4n, with one electrode left unconnected in between. CONSTITUTION:When a compressive force acts on the part of an output electrode 12 and a tensile force on the part of an output electrode 16, the directions of polarization for common earth electrodes of the output electrodes 12 and 16 are as indicated by arrows 20 of broken lines directed from the output electrodes to the earth electrodes likewise respectively, while the directions of the forces acting on the part of the output electrode 12 and on the part of the electrode 16 are reverse to each other as indicated by solid lines 21 and 22, respectively, and therefore voltages of reverse polarities are generated in the output electrode 12 and the output electrode 16. Accordingly, a differential output of these two output voltages turns to be proportional substantially with an applied acceleration. According to this constitution, an acceleration sensor for which angle adjustment at the time of setting is unnecessary is obtained by a simple structure using a piezoelectric ceramic ring of a single body. |
