| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a power steering device capable of suppressing a torque variation when a steering wheel is turned back. <P>SOLUTION: The power steering device is equipped with exhaust passages to exhaust to a reserver tank 60c the liquid pressure in the first cylinder chamber 18 and second cylinder chamber 20 of a power cylinder 12, return check valves 64 installed in the respective exhaust passages and having a free piston 70 to make relative open-close changeover of each exhaust passage in accordance with the difference in the liquid pressure between the two chambers of the power cylinder 12 owing to the operation of an oil pump 28, and a back pressure valve 66 to admit passing of the liquid pressure equal to or over the set pressure P<SB>SET</SB>only to the reserver tank 60c from each return check valve 64, wherein the output drive force of an electric motor 30 is limited when the motion of the free piston 70 after turning-back of the steering wheel by the driver is sensed. <P>COPYRIGHT: (C)2007,JPO&INPIT |
