Damping force generation system and vehicle suspension system constructed by including the same

Abstract

It is an object of the invention to improve the utility of an electromagnetic absorber system which is disposed in a suspension system of a vehicle and which generates a damping force by a generation force of a motor. The electromagnetic absorber systemis equipped with high-speed-motion responding means, thereby obviating an insufficiency of the damping force and a deterioration of the controllability in a high-speed stroke motion. More specifically, a hydraulic absorberis provided in combination with the electromagnetic absorber system such that the hydraulic absorberoperates in the high-speed motion in which an electromotive force of the motorexceeds a power source voltage Further, two motors having mutually different T-N characteristics are provided, and the two motors are selectively operated depending upon a stroke speed. Further, a variable resistor is interposed between the motor and the power source, and a resistance value of the variable resistor is increased in the high-speed motion to realize a decrease in a time constant of the motor, etc. Moreover, to cope with a large extent of unevenness of a road surface, an active stroke motion is performed by a drive force of the motor, thereby preventing the high-speed motion from being performed.