| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an electrohydaulic power steering device which maintains good steering feeling and has a highly reliable failsafe function. <P>SOLUTION: This power steering device comprises: a pump 18 which always operates in response to the operation of a driving source; an open center type control valve 20 connected to the pump 18; a hydraulic cylinder 26 of which one chamber 26a is connected to the control valve 20 through a first communicating path 25 and of which the other chamber 26b is connected though a second communicating path 28; a solenoid valve 31 which connects a first communicating path 25 with a second communicating path 28, communicates them with each other, and shuts down the communication; a torque sensor 40 for detecting steering torque; a controller C which controls the switching position of the control valve 20 based on a torque signal of the torque sensor 40; and a sensor which detects failure in the system. The controller C keeps the solenoid valve 31 at a closed position 31a regardless of a steering status while the system is working properly. <P>COPYRIGHT: (C)2004,JPO |
