FRONT AND REAR WHEEL STEERING DEVICE

摘要

In a front and rear wheel steering device control for a vehicle in which the steering angle ratio of the rear wheels relative to the front wheels is variable according to the vehicle speed, provision of a manual selection means for fixing the steering angle ratio to certain fixed values which may be either positive or negative can greatly improve the maneuverability of the vehicle in both high speed and low speed ranges. However, inadvertent manual selection of the steering angle ratio is not desirable since it may cause a sudden change in the steering angle of the rear wheels. Therefore, this invention provides means for preventing the manual selection of the steering angle ratio when it is not proper. This means may be an active prohibition control of manual steering angle ratio selection means, an alarm to warn the driver or a vehicle speed control which limits the vehicle speed. The situations in which the manual selection of the steering angle ratio is not proper may be determined from such factors as vehicle acceleration, transmission shift position, steering action and so on.