| 摘要 |
PROBLEM TO BE SOLVED: To set preferable transmission ratio under the condition where antilock braking system(ABS) is operated by turning wheels according to steering, setting a transmission ratio between steering amount and turning amount in accordance with the running condition of the vehicle, and by prohibiting change of the transmission ratio while the wheels are controlled by ABS. SOLUTION: In this unit, an input shaft 20 and an output shaft 40 are connected via a transmission ratio variable mechanism 30. The input shaft 20 is connected to a steering wheel 10, and the output shaft 40 is connected to a rack shaft 51 via a rack and pinion-type gear unit 50. Wheels FW1, FW2 are connected to the both ends of the rack shaft 51. Driving of the transmission ratio variable mechanism 30 is controlled by a steering control unit 70. In addition to each of the detection signals, an input angle sensor 21, an output angle sensor 41, and a vehicle speed sensor 61, a signal indicating the operating condition of ABS is given to the steering control unit 70, from an ABS controller 62 for controlling braking fluid pressure so that the wheel will not lock while braking. Driving of the transmission ratio variable mechanism 30 is controlled with the transmission ratio as set with the above signals. |
