Patent ID: 7905470

Claim:
A vibration damper comprising: a first mounting member connected to one of a vibration generating portion and a vibration receiving portion; a second mounting member connected to the other of the vibration generating portion and the vibration receiving portion; an elastic body provided between the first mounting member and the second mounting member to connect the first mounting member and the second mounting member in an elastically deformable manner; a pressure-receiving liquid chamber filled with a magnetism responsive fluid, at least a portion of an inner wall of the pressure-receiving liquid chamber being formed of the elastic body; a secondary liquid chamber, a portion of a partition wall thereof being formed deformable such that an inner volume of the secondary liquid chamber can be increased/decreased in accordance with change in an inner pressure; an orifice communicating between the pressure-receiving liquid chamber and the secondary liquid chamber to allow the magnetism responsive fluid to pass therethrough; a coil provided around the orifice, for magnetizing the magnetism responsive fluid inside the orifice when the coil is electrically activated; and a control unit for controlling electric activation of the coil, wherein a yoke is provided in the orifice, separately therefrom, such that the yoke is situated on a magnetic path which is generated when the coil is electrically activated, and wherein a yoke forming member including a yoke as a portion thereof is formed in a tube-like shape and the orifice is formed such that it penetrates through the yoke forming member.