| 摘要 |
PURPOSE:To simplify the arrangement of a power steering unit and to aim at reducing the cost of the power steering unit, by forming, in a reaction mechanism in the power steering unit, two pressure chambers for applying fluid pressure to the front and rear of a movable piston, and by communicating both chambers with sections upstream and downstream of a control restrictor valve. CONSTITUTION:A power steering unit 10 has a pinion shaft 21 to which steering force is transmitted from an input shaft 23 through a torsion bar 24, in a housing body 11, and a servo-valve 30 is disposed in a hole in a valve housing 12 within the housing body 11. Further, a reaction mechanism 50 is disposed between the rotary valve member 31 of the servo-valve 30 and the pinion shaft 21, and has a movable piston 51 and a ball 52 as main component members. In this arrangement first and second reaction chambers 54, 55 are defined between the movable piston 51 and the pinion shaft 21 as well as the input shaft 23. Further, these reaction chambers 54, 55 are communicated with sections upstream and downstream of a control restrictor valve 79 disposed in a supply passage 72 for the servo-valve 30, through introduction passages 80, 81. |
