| 摘要 |
PURPOSE:To prevent the rise of a dynamic spring during switching of an orifice. 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. A large orifice having the one end communicated to the main liquid chamber 3 and the other end communicated with the auxiliary chamber 5 and a small orifice 10 having the one end communicated with the main liquid chamber and the other end communicated with a large orifice 7 are formed in a partition wall 1. Anon-off valve 12 to open and close a communication state between the large orifice 7 and the main liquid chamber 3 and between the small orifice 10 and the main liquid chamber 3 is rotatably arranged to the partition wall. When a communication state between the main liquid chamber 3 and the auxiliary liquid chamber 5 is switched from the large orifice 7 to the small orifice 10 through the on-off valve 12, the section of the flow passage of the communicating part between the main liquid chamber 3 and the large orifice 7 is kept at a constant value within the given rotation range of the on-off valve 12 and the length of the large orifice is also kept at a constant value. |
