| 摘要 |
PROBLEM TO BE SOLVED: To shield a shock of a motor at the time of idling and to ensure an auxiliary reduction of a switchable rigidity level by forming a preventing device by an auxiliary supporting spring forming an auxiliary chamber closed or released at a fluid connecting portion and being capable of connecting the auxiliary chamber to a chamber. SOLUTION: A fluid connecting portion 5 is provided between a chamber 2 and an auxiliary chamber 4. The fluid connecting portion 5 is formed by a movable portion 7a and openings 8a, 8b of a fitting plate 7b. Here, the movable portion 7a and the fitting plate 7b are rotated in a reverse direction each other and the openings 8a, 8b can change a cross section of the fluid connecting portion 5 from a 'close' to a 'release' at a shape of a restriction of a hole. When a high frequency vibration in a fixed portion 12 enters at the state that the fluid connecting portion is opened, a chock absorbing fluid does not arrive at the chamber 3 and a demolition of the high frequency vibration in the chamber 2 occurs. When a low frequency vibration is introduced through the fixed portion 12, the shock absorbing fluid is fed from the auxiliary chamber 4 to the chamber 3 through the chamber 2 and a restriction groove 15 and is again counter-flowed. |
