| 摘要 |
PURPOSE:To enhance the reliability of rear wheel steering operation, by detecting the steering hydraulic pressure so as to detect the cornering force of front wheels which is equivalent thereto, and by driving rear wheels by means of a motor in accordance with thus detected cornering force. CONSTITUTION:A power cylinder 13 is fed with hydraulic oil discharged from a hydraulic pump 7 so as to generate steering assist force. A right side hydraulic pressure sensor 16 is adapted to detect the hydraulic pressure in a hydraulic pressure line through which the right side hydraulic chamber 13a of the hydraulic power cylinder 13 is communicated with a control valve 9. Similarly, a left side hydraulic pressure sensor 17 is adapted to detect the hydraulic pressure in a hydraulic pressure line 15 through which the left side hydraulic chamber 13b of the hydraulic power cylinder 13 is communicated with the control valve 9. A steering hydraulic pressure difference computing and amplifying device 18 receives electric signals which are obtained by converting signals from the hydraulic pressure sensors, and computes the difference between the signals from both sensors. A control unit 24 receives thus computed difference, and controls an electric motor 25 which therefore drives rear wheels for steering operation. |
