| 摘要 |
<p>PURPOSE:To avoid the clutch shock by gradually starting an electric motor according to the increase of the detected torque when the detected torque reaches the first prescribed value before the detected torque reaches the second prescribed value with which power assistance is actually executed. CONSTITUTION:In a control circuit 60, when a car speed sensor 64 detects the low speed traveling, the steering torque detected by a torque sensor 66 reaches the first prescribed value lower than the second prescribed value with which power assistance is actually executed, a microcomputer 62 drives a power transistor 76 through an amplifier 74 by the duty ratio signal corresponding to the detected torque, and an electric motor 38 is started through the right or left revolution-drive circuits 54 or 56 corresponding to the steering direction, and the electric motor 38 is gradually started up with the number of revolution corresponding to the increase of the detected torque. When the detected torque reaches the second prescribed value, an electromagnetic clutch 28 is excited through an amplifier 72, with the duty ratio signal corresponding to the detected torque, and power assistance is executed. Therefore, the power assistance having the superior responsiveness can be executed free from clutch shock.</p> |
