Abstract: An electro-rheological fluid comprising an electrically insulating liquid as the dispersion medium, porous solid particles as the dispersed phase, a dispersant, and a polyhydric alcohol having a boiling point of not lower than 250.degree. C., a melting point of not higher than 15.degree. C. and a viscosity of not higher than 300 cp (as measured at 20.degree. C.), or comprising an electrically insulating liquid as the dispersion medium, porous solid particles as the dispersed phase, a polyhydric alcohol and/or water, and an ashless dispersant.

Abstract: A damper device for a suspension device for a vehicle in which the damping fluid is an electro-viscosity fluid and an electric control unit is provided for controlling the electric field in the electro-viscosity fluid, to thereby control the damping factor of the damper device. A sensor is used for detecting vibration at the wheels, such as an acceleration rate of the suspension device, and the detected vibration is used for controlling the strength of the electric field, to thereby control the damping characteristic of the damper.

Abstract: A viscous damper wherein the viscosity of a fluid, such as an oil, is used to generate damping effect when the fluid is passed through a restricted orifice or slit. Electrodes are arranged to face each other across the orifice or slit so that an electric field is created in a direction which is transverse to the direction of the fluid flow in the orifice or slit. The voltage applied to the electrodes is controlled in accordance with a frequency of vibration of a vibrating member to be damped. The viscosity of the fluid is controlled by applying a voltage thereto, so that a desired damping effect is obtained within a wide range of the frequency of the vibrating body.

Abstract: A viscous damper wherein the viscosity of a fluid, such as an oil, is used to generate damping effect when the fluid is passed through a restricted orifice or slit. Electrodes are arranged to face each other across the orifice or slit so that an electric field is created in a direction which is transverse to the direction of the fluid flow in the orifice or slit. The voltage applied to the electrodes is controlled in accordance with a frequency of vibration of a vibrating member to be damped. The viscosity of the fluid is controlled by applying a voltage thereto, so that a desired damping effect is obtained within a wide range of the frequency of the vibrating body.