Patent ID: 6064166
Filing Date: 2000-05-16
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;a vehicle speed sensor for sensing a vehicle speed; anda control circuit for switching a control mode between a first mode in which a first voltage V1 is applied to the electric motor and a second mode in which no voltage or a second voltage V2 lower than the first voltage V1 is applied to the electric motor;wherein the control circuit includes a threshold computation circuit for determining a threshold of a predetermined physical quantity as a function of the vehicle speed V sensed by the vehicle sensor, and comparison means for comparing a value of the physical quantity with the threshold determined by the threshold computation circuit, the control circuit being operative to switch the control mode from the first mode to the second mode on the basis of a comparison result obtained by the comparison means.