| 摘要 |
<p>PURPOSE:To simplify the construction of a hydraulic circuit by providing the first and second operation valve groups in the respective discharge paths of the first and second hydraulic pumps and providing a confluence valve for separating and joining the respective discharge paths from/to each other and joining the same to be communi cated to a service valve. CONSTITUTION:When a confluence valve 7 is put in a separate position (i), discharge paths Pa, Pb of the first and second pumps P1, P2 are respectively separated and adapted from/to each other to supply discharge hydraulic pressure to actuators by each valve operation of the operation valve groups A, B. When the valve is put in the first confluence position (ii), both discharge paths Pa, Pb are communication with each other through a check valve 9 and put together by switching a boom valve 3 to supply the discharge hydraulic pressure to a boom cylinder 3a. When it is put in the second confluence position (iii), the check valve 9 is turned reversely so that both discharge paths are put together to supply the discharge hydraulic pressure to an arm cylinder 4a, and when it is put in the third confluence position (iv), the paths are bidirectionally communicated. When it is put in the service position (v), the dis charge paths Pa, Pb are communicated with a service valve 8 to put together the discharge hydraulic pressures and supply the same. Thus, the construction of a hydrau lic circuit can be simplified.</p> |
