| 摘要 |
PURPOSE:To definitely obtain responses when a handle is rotated by controlling the control pressure applied to a reaction force mechanism according to the car speed and such, corresponding to the steering pressure only at high speed running. CONSTITUTION:A power steering device is provided with a servo valve 20 that controls the supply and exhaust of pressurized oil into a power cylinder according to the relative rotation of output shafts 24 and 11. In this case, the exhaust pressure of a supply pump 50 is guided to the supply port 26 of the servo valve 20 through a first flowrate control valve 51 that always constantly keeps the pressure before and behind an orifice 52 and the excessive flow of the pressurized oil passing through the pertinent valve 51 is guided to the introduction port 40 for a reaction force cylinder chamber 33 in the reaction force mechanism through the same second flowrate control valve 55. Besides, the introduction port 40 is connected to a reservoir through an electromagnetic relief valve 60 and a variable throttle control valve 80 that are controlled corresponding to the car speed and such. The control valve 80 is controlled in the close section by the steering pressure signals of an electromagnetic switching valve 90 only at high speed running. |
