| 摘要 |
PURPOSE:To ensure traveling stability by changing a steering ratio characteristic from a first characteristic at the time of ordinary traveling to a second characteristic on a stable side and setting a lock control at the time of wheel lock and returning to the first characteristic when a vehicle speed signal except the vehicle speed of zero is continuously outputted for a certain time. CONSTITUTION:A rear wheel steering mechanism 10 has a steering ratio control mechanism 64 whose input shaft is a rear steering shaft 60 interlocked with a front wheel steering device 14 and, by controlling the control motor 100 of the mechanism 64 by means of a controller 132, a control valve 46 is controlled via an output rod. In this case, when wheel lock is detected from the outputs of a first vehicle speed sensor 122 and a brake switch, a steering ratio is changed from a first characteristic at the time of ordinary traveling to a second characteristic on a stable side to set a lock control condition. At the point of time when a vehicle speed signal except the vehicle speed of zero is continuously outputted for a certain time, the steering ratio is changed from the second characteristic to the first characteristic to remove the lock control condition. |
