| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a power steering device giving no sense of incongruity to a driver by preventing a sudden change of steering force of a steering wheel in opening a fail-safe valve in failure. <P>SOLUTION: This power steering device is furnished with a by-pass passage 32 to communicate between two chambers 18, 20 of a power cylinder 12, the fail-safe valve 34 to open and close this by-pass passage 32 and a controller 36. The controller detects abnormality of the power steering device, makes the fail-safe valve in an opened state when detecting that a hydraulic pump 28 to give a hydraulic differential between the two chambers of the power cylinder is free to drive and actuates the hydraulic pump so as to discharge liquid to the chamber on the high pressure side of the two chambers of the power cylinder. <P>COPYRIGHT: (C)2007,JPO&INPIT |
