| 摘要 |
PROBLEM TO BE SOLVED: To provide a magnetic fluid which is excellent in the long term stability of fluid characteristics and the responsiveness of changes of the fluid characteristics to external magnetic fields, and to provide a damper which includes the magnetic fluid and accurately adjusts the attenuation force over a long period.SOLUTION: A damper 1 includes: a circular cylinder 2 having closed upper and lower ends; a piston rod 31 provided so as to penetrate through a ceiling part 21 of the cylinder 2 and extend in the cylinder 2; a piston 3 provided at a lower end of the piston rod 31 and vertically sliding in the cylinder 2; and a magnetic fluid 10 housed in the cylinder 2. Further, magnetic field formation means, providing the magnetic field to the magnetic fluid 10, is provided at the damper 1. Further, the magnetic fluid 10 contains particles composed of an Fe-Cr group metal material. In the damper 1, the attenuation force is adjusted by adjusting the presence and the strength of the magnetic field provided to the magnetic fluid 10. |
