| 摘要 |
PROBLEM TO BE SOLVED: To provide a magnetic fluid which has excellent long term stability of fluid characteristics and excellent responsiveness of fluid characteristic changes to external magnetic fields, and to provide a damper which includes the magnetic fluid and accurately adjusts the damping force for a long term.SOLUTION: A damper 1 has: a cylinder 2 closed at upper and lower ends; a piston rod 31 provided so as to penetrate a ceiling part 21 of the cylinder 2 and extend into 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, the damper 1 is provided with magnetic field formation means providing a magnetic field to the magnetic fluid 10. Furthermore, the magnetic fluid contains particles composed of Fe-B based metal materials. The damper 1 adjusts the damping force by adjusting the presence and the strength of the magnetic field provided to the magnetic fluid 10. |
