| 摘要 |
PURPOSE:To obtain a desired vibration isolating characteristic selectively according to inputted vibration by forming an orifice passage of three orifice passages, mutually different in the cross-sectional area/length ratio, provided at partition members, as well as providing a multi-stage switching valve means. CONSTITUTION:In the state of a valve body 64 being held in a protruding position, a pressure receiving chamber 34 and a balance chamber 36 are communicated through a first and a second orifice passages 56, 58, but because of the cross sectional area/length ratio of the passage 56 being small and its flow resistance being large compared to those of the passage 58, the vibration of a fluid between the chambers 34, 36 at the time of vibration input is solely generated in the passage 58, thereby displaying low-moving spring effect on the inputted vibration in an intermediate frequency band: In the state of the valve body 64 being held in an intermediate position, the chambers 34, 36 are communicated only through the passage 56, thus displaying damping effect on inputted vibration in a low frequency band. In the state of the valve body 64 being held in a contracting position, the chambers 34, 36 are communicated through the passage 56 and a third orifice passage 62, and vibration is damped by the passage 62 because of the above mentioned ratio. |
