| 摘要 |
PURPOSE:To improve the drivability on the slippery road face in particular by freely changing the width of the dead zone maintaining rear wheels in the neutral state in response to the state of the running road face when the steering quantity of front wheels is smaller than the preset quantity. CONSTITUTION:A rear wheel steering device B has a power cylinder 35 fed with the pressure oil from a hydraulic pump 22 via a flow dividing valve 23, and the power cylinder 35 is operated and controlled to steer rear wheels in the reverse phase so that the steering quantity of the rear wheels is increased as the steering quantity of front wheels is increased by a spool valve interlocked with a built-in cam plate. The rear wheels are kept in the neutral state in the dead zone region where the steering quantity of the front wheels is smaller than the preset value. In this case, an electromagnetic flow control valve 51 is provided on a conduit pipe P4, and it is controlled by a control circuit 53 so that the width of the dead zone is increased when the nonslippery state of the running road face is detected by a road face state detector 52 and the width of the dead zone is decreased when the slippery state is detected. |
