| 摘要 |
PURPOSE:To miniaturize a sub-pump by providing a vehicle speed response valve on one of a feed passage between said sub-pump for feeding pressure oil to a hydraulic reaction chamber and said hydraulic reaction chamber and a discharge passage between said hydraulic reaction chamber and a tank, and a pressure response valve on the other. CONSTITUTION:A power steering device has a servo valve 1 which distributingly feeds oil pressure from a main pump 14 to a power cylinder 15 by means of the relative rotations of a pair of valve members. It also has a reaction mechanism 2 for generating a steering reaction in accordance with the feeding oil pressure from a sub-pump 37 to an oil pressure reaction chamber 27, and a pressure controlling mechanism 3 for controlling a feeding oil pressure to the oil pressure reaction chamber 27. In this case, the pressure controlling mechanism 3 has a vehicle speed response valve 30 which is provided in a feed passage 40 to the reaction chamber 27 and which includes a solenoid 34 which is controlled in its electrification based on the detected signal of a vehicle speed, and a pressure response valve 31 which is provided in a discharge passage 56 from the reaction chamber 27 and which includes a sleeve 43 which is displaced by the delivery pressure of the main pump 14 introduced to a pressure chamber 57.
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