| 摘要 |
<p>PURPOSE:To prevent a handle operation from becoming heavy when a drive unit fails by providing a switch means between an electric motor and its drive unit and closing the switch means if the handle torque becomes a predetermined value or more. CONSTITUTION:When a switch of a vehicle is turned on, the coil 32 of a relay 30 is energized by a control unit 24, the normally-opened contact 31 of the relay 30 is closed, and the output of a generator 23 is fed to an electric motor 16. This electric motor 16 is energized and controlled in response to the difference between a target current value calculated based on outputs of a torque sensor 15 and a vehicle speed detector 25 and a load current value through a resistor R1 detecting the load current Id flowing through the electric motor 16. If such a failure occurs that the generator 23 is stopped to operate due to an open circuit of the field winding of the generator 23 and the handle torque exceeds the preset torque, the relay 30 is deenergized and its normally-opened contact 31 is opened, thus a steering device is set to a manual condition.</p> |
