| 摘要 |
PURPOSE:To prevent rise of a dynamic spring when an orifice is switched. CONSTITUTION:A main liquid chamber 3 surrounded with a resilient body 2 is formed on the upper surface side of a partition wall 1 and an auxiliary liquid chamber 5 surrounded with a diaphragm 4 is formed on the under surface side thereof. A large orifice 7 having the one end communicated to the main liquid chamber 3 and the other end communicated to the auxiliary liquid chamber 5 and a small orifice 10 having the one end communicated with the main liquid chamber 3 and the other end communicated with the large orifice 7, and an opening part 27 for intercommunicating the main and auxiliary liquid chambers 3 and 5 are formed in the partition wall 1. The opening part 27 is closed with a subdiaphragm 28. An on-off valve 12 is rotatably arranged to the partition wall 1 and a communicating state between the large orifice 7 and the main liquid chamber 3 and between the small orifice 10 and the main liquid chamber 3 and the opening part 27 are brought into an openable state. The section of the flow passage of a communicating part 20 between the main liquid chamber 3 and the large orifice 7 is kept at an initial value in the given rotation range of the on-off valve 12. Thereafter, the opening part 27 is gradually started to open following rotation of the on-off valve 12 and the communicating part 20 is gradually closed. |
