PURPOSE: To obtain a control method for the damping force of a shock absorber with which the stop position of a shock objective aricle can be kept constant, by adjusting the damping force in correspondence with the collision speed and weight of the shock objective article.
CONSTITUTION: A laser displacement meter 60 detects the displacement quantity per time of a receiving surface 20, and a calculator 58 calculates the shift speed of the receiving surface 20 and inputs the signal into a controller 56. Then, the controller 56 calculates the damping force so that the receiving surface 20 stops at an equal accelerating speed within a previously set shift stroke L of a piston. Then, in order to allow the electric viscous fluid 14 to have the viscous resistance corresponding to the damping force, the voltage applied to a pair of eletrodes of a positive electrode 28 and a negative electrode 30 from a high voltage power source 32 is increased and decreased by an amplifier 52. Accordingly, in correspondence with the variation of the speed and weight of an objective article M, the characteristic of a shock absorber can be varied instantly, and the positioning precision for the objective article M can be improved.
ENDO SHIGEKI
OKAFUJI YUKITAKA
TANAKA SHUICHI
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