| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a power steering device allowing a driver to achieve non-assisted steering by securely cutting off power supply to a fail-safe valve in failure to eliminate a pressure difference in power cylinder chambers. <P>SOLUTION: This power steering device comprises a steering assist means having a hydraulic system for performing steering assist by leading the delivery pressure of a pump to two chambers of a power cylinder partitioned by a piston, an assisted steering control means outputting control instructions to the hydraulic system, a bypass circuit communicating two power cylinder chambers with each other, and the fail-safe valve installed in the bypass circuit and capable of electronically switching the communicated-non-communicated state of the bypass circuit based on instruction signals from the assisted steering control means. A plurality of power switching means capable of turning ON/OFF the power supply are installed in series in a power supply line to the fail-safe valve. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
