To provide damping characteristics with relativity in a working direction by a simple structure in which a check valve and a switching valve are not used in a magnetic viscous fluid damper A in which a piston head 2 is fitted to a cylinder body 1 having a hollow part filled with magnetic viscous fluid F, first and second fluid chambers 3 and 4 are demarcated in the moving direction, a magnetic field is formed in a fluid passage 7 across the fluid chambers 3 and 4 to increase the viscous resistance of the magnetic viscous fluid F so as to increase damping force.
A passage width change part 7a in which its radial passage width gradually decreases from the first fluid chamber 3 toward the second fluid chamber 4 is formed in an annular fluid passage 7 to change the intensity of magnetic field. By this, the flow resistance of the magnetic viscous fluid F flowing from the fluid chamber 3 to the fluid chamber 4 is increased in operating the damper in the retracting side. On the other hand, the flow resistance of the magnetic viscous fluid F flowing in the opposite direction is decreased in operating the damper in the extending direction.
OKUDA KAORU
SHINKO SANGYO TRADING
Hiroshi Koyama
Hiroshi Takeuchi
Takahisa Shimada
Yuji Takeuchi
Katsumi Imae
Atsushi Fujita
Kazunari Ninomiya
Tomoo Harada
Takashi Goto
Iseki Katsumori