摘要 |
PURPOSE:To prevent the wide-range transmission of vibration in a device to be used for the mount of an engine by keeping a dynamic spring constant and a damping coefficient together at a high level in the vibration-damping area of low frequency and at a low level in the vibration-proof area of high frequency. CONSTITUTION:On the basis of the output signal of a control device 12 receiving the signal of the relative displacement between an engine and a car body, a change-over switch 11 switches over a battery 10 connected to a coil 9 between positive and negative poles. In the vibration-damping area of low frequency, a partitionplate 5 composed of a permanent magnet is moved downward by a coil 9 when an elastic wall 1 is contracted, and upward when extended for increasing the pressure difference between fluid chambers A and B to increase the effect of damping. In the vibration-proof area of high frequency, the partition plate 5 is moved upward when the elastic wall 1 is contracted, and downward when extended for reducing the pressure difference between fluid chambers A and B to reduce the effect of damping. |