| 摘要 |
PURPOSE:To provide a titled hydraulic control device with which aux. horse- power controlling function is in effect when an electric control device goes in failure. CONSTITUTION:An aux. working oil chamber 8c is provided in a compen. piston mechanism 8 of a regulator 5 of a variable displacement type oil hydraulic pump 1, and discharge pressure is introduced to this chamber 8c via selector valves 19, 17 when a control device goes in failure to enable discharge from the oil pressure pump. Also when the control device is in failure, a specified current for setting a specific large discharge amount is supplied to a solenoid proportional decompression valve 9 so that it is possible to make horse-power control (discharge amount control) with the command pressure of a working oil chamber 8b and the discharge pressure of the aux. chamber 8c. |
