| 摘要 |
PROBLEM TO BE SOLVED: To provide an electric power steering device capable of effectively suppressing generation of tooth hitting sound in a gear reduction gear for reducing speed and transmitting rotation of a motor for steering assistance to a steering mechanism without a mechanical backlash adjustment. SOLUTION: In this electric power steering device, steering torque added to a steering wheel 30 is detected by a torque sensor 4 arranged in the middle of a steering shaft 3, and steering is assisted by transmitting the rotation of the motor 6 for steering assistance driven based on the detected torque to the steering shaft 3 via a worm gear speed reducer 60. In the electric power steering device, the detected torque of the torque sensor 4 is imparted to an assist control part 7 via a frequency analysis part 8. The assist control part 7 decides whether or not a torque component having a frequency of a prescribed value or more is contained in the detected torque of the torque sensor 4 based on an analysis result by the frequency analysis part 8. When the torque component is contained, the motor 6 is driven and controlled so that rotary torque fixed in advance may be generated in one direction. COPYRIGHT: (C)2009,JPO&INPIT |
