| 摘要 |
<p>PURPOSE:To prevent the burning of a motor by restricting the max. value of the motor electric current according to the magnitude of the average electric current of the motor electric current at each prescribed time when electric current flows continuously for a prescribed time or more in the motor which is driven according to the magnitude of steering torque. CONSTITUTION:When a steering wheel 1 is operated, the motor electric current corresponding to the steering torque at this time is supplied into a motor 13 by a control unit 9 into which the output signals of a torque sensor 3 and a car speed sensor 10 are inputted. The power of the motor 13 is transmitted to a steering shaft 2c through the meshing of a worm shaft 15 and a worm wheel 16, and a steering power is assisted. At this time, the motor electric current is monitored periodically, and the average electric current is calculated at each prescribed time. When electric current flows continuously for a prescribed time or more in the motor 13, the max. value of the motor electric current is restricted according to the magnitude of the above-described average electric current. Therefore, the motor and the power element of the control unit 9 are protected from thermal destruction.</p> |
