Four-wheel steering device

Abstract

Abstract PURPOSE:To enhance the safety by prohibiting actuation of a rear wheel steering means if the output of a steering angle sensing means is smaller than a specified value near the neutral position and if the rear wheel steering actuation sensing condition has lasted over a certain period of time. CONSTITUTION:Through a cylinder the front wheels 1 are steered from a steering wheel 10, and a same-phase control valve 98 uses this oil pressure as a pilot pressure and supplies one chamber of a rear power cylinder 90 with a same-phase steering force oil pressure. Meantime a controller 126 determines the steering angle speed from a signal given by a steering angle sensor 128, supplies a control signal to an opposite phase control valve 100 on the basis of the determined steering angle speed and a signal given by a car speed sensor 127, applies the opposite phase steering force oil pressure to the other chamber of the rear power cylinder 90, and steers the rear wheels 82 with the synthesized steering force. If the output of the steering angle sensor 128 is smaller than a specified value near the neutral position and if the rear wheel steering operation sensed from a signal given by a same-phase and an opposite phase pressure sensing switch 131, 132 has lasted over a certain period of time, the steering operation by the control valves 89, 100 is prohibited by relief valves 135, 137.

Inventors

• 👤 Makoto Kishi
• 👤 誠 貴志
• 👤 Hiroshi Fujii
• 👤 啓史 藤井

Bibliographic Details