| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a fluid pressure control device of a construction machine capable of increasing a flow rate of working fluid for a control valve arranged in the second circuit system.SOLUTION: A fluid pressure control device 100 of a construction machine comprises a first circuit system 10 connected to a first pump P1; a second circuit system 20 connected to a second pump P2; a change-over valve 25 having a normal position, a straight forwarding position, and a merging position where working fluid at a branch part 13a is merged with a second intermediate passage 21; and an opening or closing mechanism 14 for opening or closing a first intermediate passage 11. When at least one control valve 222 of control valves where it is desired to merge with a downstream side control valve of a second running control valve 221 is changed over to a position other than the intermediate position, the first intermediate passage 11 is closed by the opening or closing mechanism 14 and the changing-over valve 25 is changed over to the merging position to cause the working fluid of the first pump P1 to be merged with the working fluid of the second pump P2.</p> |
