| 摘要 |
PROBLEM TO BE SOLVED: To reduce the wear of the leading ones of rear wheels in low-speed running and enhance the maneuvering stability in high-speed running. SOLUTION: A leading wheel steering means is controlled by a controller so that the leading ones 13 of rear wheels 13 are steered in the same direction as the front wheels 11 on the basis of the sensing outputs of a front steering angle sensor and vehicle speed sensor. When the vehicle speed sensor senses a vehicle speed between the first and the second specified value, the controller controls the leading rear wheel steering means so that the steering angle ratioδr/δf of the leading rear wheels relative to the front wheels 11 lessens gradually from the first steering angle ratio toward the second steering angle ratio with increasing vehicle speed; when the vehicle speed sensor senses a vehicle speed between zero and the first specified value, controls the leading rear wheel steering means so that the first steering angle ratio is generated; and when the sensor senses a vehicle speed over the second value, controls the leading rear wheel steering means so that the second steering angle ratio is established. |
