| 摘要 |
PROBLEM TO BE SOLVED: To flexibly deal with various flow balances required for two actuators while suppressing unnecessary energy consumption due to throttle pressure loss of a pressure compensation valve during combined control for simultaneously driving the two actuators high in maximum required flow.SOLUTION: If a required flow of a boom cylinder 3a is lower than a predetermined flow, the boom cylinder 3a is driven only by pressure oil discharged from a single-flow main pump 202. If the required flow of the boom cylinder 3a is higher than the predetermined flow, the boom cylinder 3a is driven by the pressure oil and pressure oil discharged from a first discharge port 102a of a split-flow main pump 102 that are merged together. If a required flow of an arm cylinder 3b is lower than a predetermined flow, the arm cylinder 3b is driven only by pressure oil discharged from a second discharge port 102b of the split-flow main pump 102. If the required flow of the arm cylinder 3b is higher than the predetermined flow, the arm cylinder 3b is driven by the pressure oil discharged from the first discharge port 102a and that discharged from the second discharge port 102b that are merged together. |
