To always obtain an optimum steering characteristic according to the change of vehicle speed and the change of a steering wheel steering angle in a vehicle of such constitution as to steer by changing the rotating speed of lateral travel driving wheels in addition to steering steered wheels.
Lateral travel driving wheels Wr independently driven being respectively connected to a pair of continuously variable transmissions are increased/reduced in speed at the same rotating speed by the operation of a change lever 10 so as to move a vehicle forward and backward, and when the steering angle of a steering wheel 8 exceeds the specified value, the turning inside travel driving wheel speed is reduced, and the turning outside travel driving wheel speed is increased to turn the vehicle. When the steering wheel steering angle becomes the specified value or more during low speed forward travel, the turning inside travel driving wheel stops to make a pivotal turn, but during high speed forward travel and backward travel, a pivotal turn is not made even if the steering wheel steering angle becomes the specified value or more.
ICHIKAWA KATSUHISA
SHINOKAWA MASAHIDE
YAMAZAKI NOBUO
