Patent ID: 6216814
Filing Date: 2001-04-17
Classification: B62D

Abstract:
A power steering apparatus, comprising:an electric motor;a pump to be driven by the electric motor for generating a hydraulic pressure for steering assist;an electric current sensor for sensing an electric current flowing through the electric motor; anda control circuit which is capable of switching a control mode between a first mode in which a first voltage is applied to the electric motor when a steering operation is performed and a second mode in which a second voltage lower than the first voltage is applied to the electric motor when a steering operation is not performed;wherein the control circuit includes means for judging (a) whether the electric current sensed by the electric current sensor is higher than a first threshold in the second mode and (b) whether a change rate of the electric current sensed by the electric current sensor is higher than a second threshold in the second mode, and the control circuit switches the control mode from the second mode to the first mode if at least one of the conditions (a) and (b) is satisfied.