| 摘要 |
PURPOSE:To prevent an excessive change of the current due to the abnormality of a vehicle speed sensor by continuously setting the previously set current value when the detected vehicle speed is abruptly changed. CONSTITUTION:When the vehicle speed is a predetermined value or less, the current to a solenoid valve 14 is kept at the maximum value, and the discharge oil from a pump is wholly returned to a tank. Under this condition, extension quantities of output rods of power cylinders are medium and equal, and rear wheels 18A, 18B are kept at a straight advance position. Subsequently, as the vehicle speed is increased, the current to the solenoid valve 14 is decreased, and the steering quantity of the rear wheels 18A, 18B against front wheels 17A, 17B is increased. When the detected vehicle speed is abruptly changed from the previously detected vehicle speed, the current is continuously set to the value set at a predetermined time ago. |
