| 摘要 |
PROBLEM TO BE SOLVED: To enhance the processing accuracy and to satisfy the surface roughness by parting a main liquid chamber from an auxiliary liquid chamber with a partition member made of a low moisture-absorbent material, and by forming a communication passage between the main liquid chamber and the auxiliary liquid chamber so that the communication passage is opened and closed by a valve element. SOLUTION: An outer cylinder 16 incorporates an intermediate cylinder and an intermediate block 24 made of a low moisture-absorbent material and serving as a partition member, a cut-out part 28A and the intermediate block 24 defining therebetween a main liquid chamber 30, and the intermediate block 24, a thin rubber layer 18 and a diaphragm 20 defining an auxiliary liquid chamber 32 surrounded thereby, and a communication passage 56 is formed between the main liquid chamber 30 and the auxiliary liquid chamber 56, and is adapted to be opened and closed by a rotor 36 which is a valve element inserted rotatably in a circular hole 34 and a cylindrical through-hole 35 and made of a low moisture-absorbent material. With this arrangement, it is possible to enhance the processing accuracy, to reduce the processing cost and to satisfy the surface roughness. |
