| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a power steering device enabling 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 is provided with a reversible type pump having a pair of outlets for supplying an oil pressure to both of pressure chambers of a hydraulic power cylinder through first and second passages, an electric motor for normally and reversely rotating the reversible type pump, an electric motor control means for outputting a drive signal with respect to the electric motor based on necessary steering assist force in order to make the electric motor generate the required oil pressure, a communication passage for communicating the first and the second passages, a solenoid valve provided in the communication passage and cutting off the communication passage when the electric current is supplied and communicating the communication passage when the power supply is cut off, and a first relay provided between the solenoid valve and the power supply and a second relay provided between the solenoid valve and the ground on an electric current supply circuit of the solenoid valve. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
