| 摘要 |
<p>PURPOSE:To avoid the delay of power assistance by starting an electric motor when the detected torque by a torque sensor reaches the first prescribed value before said detected torque becomes over the second prescribed value and power assistance is actually executed. CONSTITUTION:A controller 60 receives the signals of a car speed sensor 64 and a torque sensor 69 for detecting the steering torque of a steering wheel 10 and judges the steering direction, and when the detected torque exceeds the second set value in the low speed traveling, an electric motor 38 is driven in the same direction through a polarity selecting circuit 52, and an electromagnetic powder clutch 28 is excited according to the detected torque, and power assistance is executed. In this case, in order to dissolve the delay of the power assistance due to the starting-up of the electric motor 38, when the detected torque reaches the first set value which is set lower than the second set value, the electric motor 38 is previously started with the electromagnetic powder clutch 28 in OFF-state. Therefore, the proper power assistance having the high responsiveness is permitted.</p> |
