| 摘要 |
PURPOSE:To obtain a steep pulse characteristic, by providing a diaphragm at the center of pasted type piezoelectric element, elastically fixing the surrounding of the diaphragm to a case with a buffer member and arranging a sound absorbing member at the bottom of the case. CONSTITUTION:A diaphragm 13 formed with a metal or a resin is fitted to a coupling shaft 12 located at the center of a pasted type piezoelectric element 11 made of a piezoelectric ceramic. The surrounding of the diaphragm 13 is elastically fixed to the inside surface of a cylindrical case 17 with a buffer member 20 such as elastic rubber formed to circular ring shape so as to suppress mechanical vibration. A sound absorbing member 21 is arranged at the bottom of the case 17. The element 11 and lead wires 19, 19' are electrically connected with terminals 16, 16'. Thus, the leading and trailing time of pulses can show 0.1 millisecond or below. |
