| 摘要 |
PURPOSE:To reduce the size of the whole device by bending only sub centering springs whose spring force is small to steer rear wheels at the time of a normal condition, and maintaining the rear wheels at neutral positions through the large spring force of a main centering spring at the time of a failed condition. CONSTITUTION:At the normal condition where lock pins 27, 28 are in unlocking conditions, only sub centering springs 25, 26 whose spring force is small are bent with the movement of a rack 2 based on steering force from a motor 11 to steer the rear wheels, and while feeding back a control signal obtained by detecting its steering condition, the rear wheels are controlled to be returned at neutral positions. At the time of a failed condition during steering the rear wheels, on the other hand, the rack 2 is returned to its neutral position through the spring force by sub centering springs 25, 26 to absorb the influence by external disturbance from rear wheel side through large spring force of the main centering spring 23 by the engagement of the lock pins 27, 28 with spring receiving members 21, 22 on rack 2 side and maintain the rear wheels in locking conditions at neutral positions. |
