Title:
MOTOR DRIVEN POWER STEERING DEVICE
Document Type and Number:
Japanese Patent JP3517715
Kind Code:
B2
Abstract:
PURPOSE: To provide a motor driven power steering device in which a failure in a driving current detection circuit of a steering force assisting motor can be detected in a short time so as to prevent excessive steering assisting force.
CONSTITUTION: In a motor driven power steering device, in which a motor current target value of a steering force assisting motor 5 determined based on a detection value of steering torque is adopted as a target value of automatic control and a detection value of a driving current of the motor 5 is adopted as a feedback value of the automatic control to drive-control the motor 5, and when a state wherein the target value and the feedback value are different from each other more than a specified value continues for a specific time, generation of a failure is judged so as to output a fail-safe signal for operation to a safe side, a steering torque comparing means 20 for comparing a steering torque value detected by a steering torque sensor 2 with a specified steering torque value is provided. Further, an abnormality detecting means 21 is provided, which outputs the fail-safe signal when the motor current target value is within a range of the specified motor current target value and a detection value of the driving current of the motor 5 is within a range of the specified driving current, in the case where the steering torque value is not more than the specified steering torque value.
Inventors:
Nishimoto, Mitsuhiko
Application Number:
JP12643194A
Publication Date:
April 12, 2004
Filing Date:
June 08, 1994
Export Citation:
Assignee:
KOYO SEIKO CO LTD
International Classes:
B62D6/00; B62D5/04; (IPC1-7): B62D6/00; B62D5/04
Attorney, Agent or Firm:
河野 登夫
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