Toyoda Koki Kabushiki Kaisha

Kimio Yamaguchi

Kunihiko Eto

Kazumasa Kodama

Yuzo Kubota

Hisashi Koba

A control apparatus for a power-assisted steering system which includes a servo valve associated with a hydraulic power cylinder to selectively direct the flow of fluid under pressure from a source of hydraulic pressure to opposite fluid chambers of the power cylinder in response to operation of a steering wheel and an electrically operated control valve arranged to control hydraulic pressure for power assist applied to the servo valve in accordance with a control current applied thereto. The control apparatus is arranged to control the value of the control current in such a manner that the hydraulic pressure for power assist is decreased when the steering wheel is returned to its neutral position from its steered position during low speed travel of the vehicle and that the hydraulic pressure for power assist is increased when the steering wheel is returned to its neutral position from its steered position during high speed travel of the vehicle.

Growing community of inventors

Gotenba, Japan

Kimio Yamaguchi