Mitsubishi Jidosha Kogyo Kabushiki Kaisha

Koyo Seiko Kabushiki Kaisha

Masao Murai

Hajime Kozuka

Hiroshi Yoshida

A power steering system including an input shaft coupled to a steering wheel, a torsion bar for transmitting rotation of the input shaft to an output shaft, a power cylinder coupled to the output shaft, an oil path switching valve for switching oil paths to the power cylinder in accordance with the difference of turning angle between the input shaft and the output shaft, a high pressure oil path for supplying working oil delivered from an oil pump to the power cylinder via the oil path switching valve, a low pressure oil path for returning the working oil from the power cylinder to an oil tank via the oil path switching valve, a reaction piston for exerting a restraining force between the input shaft and the output shaft to limit the difference of turning angle therebetween, a control oil path extending from the midway of the high pressure oil path to the reaction piston, a pressure control valve for controlling oil pressure in the control oil path extending to the reaction piston to a level not higher than a predetermined highest pressure, a return side orifice for communicating the control oil path between the pressure control valve and the reaction piston with the low pressure oil path, and a solenoid for actuating the pressure control valve by means of its plunger for generating an axial force which varies in accordance with a car speed and takes substantially a certain strength at every given car speed.

Growing community of inventors

Okazaki, Japan

Masao Murai