| 摘要 |
PROBLEM TO BE SOLVED: To provide a hydraulic circuit of a construction machine in which pressure losses of pressure oil passing through a center bypass passage and of pressure oil fed to a cylinder port are reduced.SOLUTION: This hydraulic circuit has: a group of directional control valves including a plurality of directional control valves arranged in tandem in a center bypass passage; and a bleed-off valve Vbo arranged in a center bypass passage downstream of the group of directional control valves. Each of the directional control valves has a first inner passage RV1 for flowing out pressure oil to the center bypass passage and a second inner passage RV2 for feeding pressure oil to a hydraulic actuator, the first inner passage flows out the pressure oil discharged from a hydraulic pump to the center bypass passage downstream of the directional control valves, thereby parallel passages are formed by the center bypass passage and the first inner passage. The second inner passage feeds pressure oil from the center bypass passage to a cylinder port through an opening of a spool and/or a bypass passage. |
