| 摘要 |
PURPOSE:To reduce the variation of the resonance frequency to the temperature, by inserting the piston using a material haing a larger coefficient of thermal expansion than the cylinder having an open end into said cylinder and supporting a part of the piston. CONSTITUTION:The piston part 5 having a closed end and forming a wall surface of a resonator is inserted into the cylinder part 4 having an open end which functions as the main body of the resonator. The part 5 is fixed and supported by screw 6. The closed end of the piston 5 is positioned inside of the screw 6 within the cylinder 4, and the piston 5 uses a material having a larger coefficient of thermal expansion than the cylinder 4. The radius R of the cylinder 4 increases as the temperature increases to lower the resonance frequency. While the length S of the cylinder 4 is obtained by subtracting an extension of the piston 5 of length (d) from the extension S+d of the cylinder part. Thus the length S decreases to increase the resonance frequency. Thus the variation of the resonance frequency can be reduced. |
