| 摘要 |
PROBLEM TO BE SOLVED: To enable a resonance frequency to be further easily controlled by making a first orifice and another second orifice independent to each other.SOLUTION: A partition member 11 for parting a main liquid chamber 12 and a sub-liquid chamber 13 is provided with a first orifice 14 and an elastic partition member 30. A valve part 35 is integrally protruded and formed with the lower surface of a pressure receiving part 31 provided at the central part of the elastic partition member 30. The valve part is pushed against a valve seat part 46a that is an upper surface of a bottom part 46 of a frame member 40 so as to open or close a central opening 47 provided at the bottom part 46. A third liquid chamber 37 is formed between the outer periphery of the valve part 35 and a supporting wall 44 and communicated with a recess space 48a provided at the frame member 40 to form a second orifice 50. The second orifice 50 is communicated with the main liquid chamber 12 through a second opening 25 provided above the recess space 48a and communicated with the sub-liquid chamber 13 through the central opening 47. Since the second opening 25 is separately provided inside a first opening 24 of the first orifice 14, it is possible to shorten a length of the second orifice 50. |
