| 摘要 |
PURPOSE:To reduce the consumption power of a hydraulic pump, by a method wherein, in a hydraulic type reduction reversing device which selectively shifts forward movement, backward movement, and a neutral state by means of a switch valve, a high relief valve is connected to the primary side of a check valve mounted to the discharge side of the hydraulic pump. CONSTITUTION:In a reduction reversing device in a switch valve 1 for shifting forward and backward movement is mounted in a piping on the discharge side of a working oil pump 8, and clutches 2 and 4 for forward and backward movement are connected to outlets 3 and 5, respectively, of said valve 1, a check valve 6 is located on the upper stream side of the switch valve 1 in the piping on the discharge side. A piping to which high and low pressure side valves 9 and 10 are connected in series, is connected to the primary side of the check valve 6, and a high pressure relief valve 11 is connected through a piping between the primary side of the check valve 6 and the primary side of a pressure regulating valve 10 for low pressure. A low pressure relief valve 18 is connected through a piping in parallel to said valve 11, and high-pressure and low-pressure pilot outlets 17 and 22 of the switch valve 1 are connected to pilot chambers 12 and 19 of the relief valves 11 and 18, respectively. |
