| 摘要 |
<p>PURPOSE:To improve running composite operability of running and a front work and to achieve the running composite operability without damaging steering performance during running alone. CONSTITUTION:Hydraulic pumps 200R and 200L are connected to first and third hydraulic circuits 301 and 303 through first and second feed lines 305 and 306. A third feed line 307 of a fourth hydraulic circuit 304 is connected to the first feed line 305 through a first confluence line 308 and connected to the second feed line 306 through a second confluence line 309. Confluence separating valves 500b and 500a are arranged to the first and second confluence lines 308 and 309. During running alone, the confluence separating valve 500a is brought into an ON-state and the confluence separating valve 500b is brought into an OFF-state. During composition operation of running and a front work, the confluence separating valve 500a is brought into an OFF-state and the confluence separating valve 500b is brought into an ON-state. Operation detectors 29a-34a to detect operation of an actuator are provided.</p> |
