摘要 |
It is an object of the present invention to make a damping force variable in a damping device that uses a magnetic fluid. In a damping device using a magnetic fluid as an operating oil, the present invention includes a groove portion 34a as a leakage magnetic field generating portion that is provided in one appropriate place or more of a pair of flow path forming members forming a fluid flow path 22b and that generates a strong leakage magnetic field to the fluid flow path 22b. Accordingly, the use of only a permanent magnet enables the behavior of magnetic particles in the magnetic fluid to be changed according to a relative position of a casing 20 and a movable portion 30 and enables a damping force to be variable, without using an electromagnet. Further, a magnetic fluid in which a specific gravity of a base liquid and that of the magnetic particles approximate each other is used so that the settlement of the magnetic particles is reduced to accelerate the behavior change of the magnetic particles, and therefore, the present invention is excellent in responsiveness at the time when the damping force is varied. <IMAGE> |