ADJUSTMENT OF DAMPING OF OSCILLATORY

PURPOSE:To adjust damping of a movable member which has a resonant system with a viscous liquid between, which is filled into a housing, for performing the damping by regulating a quantity of an air bubble which is intentionally remained in a part of the viscous liquid, thereby readily eliminating scatter of performance. CONSTITUTION:Oscillatory plates 2 are fit at both sides of a sealed housing 1 and a weight 4 is held by the inner faces of the plates via connecting rods 5. A seal member 8 is disposed on a through-hole 6 which is made through the upper wall of the sealed housing 1, and a voltage depending on a deflection of piezoelectric elements 3 caused by oscillation of the weight 4 appears at output terminals 9. In an apparatus mentioned above, when viscous oil is filled into a vacancy 7 of the sealed housing 1, an air 10 is remained in a part of the vacancy 7 and by regulating the quantity of the air 10, a viscous resistance produced by the viscous oil is controlled for performing mechanical Q. The mechanical Q is freely controlled at a final process of a finish regardless to the size of the vacancy 7 and precision of assembly or other factors, thereby providing the apparatus having stable characteristics.