| 摘要 |
PURPOSE:To prevent an engine from being stopped during operation by disposing a variable relief valve in which a pressure variable device interlocks with an operating device of a variable capacity hydraulic pump between main circuits. CONSTITUTION:Variable relief valves 5, 6 for short-circuiting main circuits 15, 16 are disposed between main circuits 15, 16, and pressure variable devices of variable relief valves 5, 6 interlock with an operating device 7 of a variable capacity hydraulic pump 2 in such a manner that as the discharge quantity of the variable capacity hydraulic pump 2 increases, the preset pressure of the variable relief valves 5, 6 are decreased. In this arrangement, load more than engine horsepower can not be applied to the variable capacity hydraulic pump 2 to prevent stopping of an engine during operation. |
