| 摘要 |
PURPOSE:To change over and control a vibrationproofing characteristic in accordance with input vibration by constituting a part of a fluid chamber wall part of a diaphragm supporting it free to displace through an elastic support member, holding a magnetostrictive element on the back of the diaphragm by way of adding a preload in the expansive direction and changing the magnetic field of the magnetic distortion element. CONSTITUTION:A yoke 60 is pressure welded on the back surface of a diaphragm 32, the diaphragm 32 is pushed up and thereby, a preload in the axial direction in accordance with elastic force of a support rubber 38 is given to a magnetostrictive element 58. By electrifying an alternating electric current to a coil 68, the magnetostrictive element 58 is influenced by a magnetic field roughly in proportion to the electrified electric current, the magnetostrictive element 58 is expansively deformed, deformation influences on the diaphragm 32, and the diaphrag, 32 changes capacity of a pressure chamber 42. By controlling electrification in accordance with a driving state of a power unit, a vibration transmission state to the side of a car body and others and by excitating the diaphragm 32 in accordance with change of internal pressure of the pressure chamber 42, it is possible to control the internal pressure of the pressure chamber 42 and to properly vary a vibrationproofing characteristic in accordance with vibration to isolate. |
