| 摘要 |
PROBLEM TO BE SOLVED: To change over characteristics of a communication passage communicating a sub liquid chamber with a main liquid chamber of an active vibration control device without requiring a special actuator. SOLUTION: The active vibration control device M arranged between an engine E which is a vibration source and a body frame F which is a support part is provided with an elastic body 14 deforming in response to vibration of the engine E, the main liquid chamber 22 with at least one part partitioned by the elastic body 14, the sub liquid chamber 23 communicated with the main liquid chamber 22 via an orifice 16, a movable member 20 facing the main liquid chamber 22, an actuator A vibrating the movable member 20, and an orifice characteristic varying means 26 facing the orifice 16. When the movable member 20 is not vibrated by actuator A, a coil 31 is continuously energized, a normally opened opening and closing valve 36 is forcibly closed by a shaft part 20a of the movable member 20, a negative pressure acting on the orifice characteristic varying means 26 is cut off, and a substantial length of the orifice 16 is changed. |
