| 摘要 |
[Problem] To provide a large hydraulic excavator permitting an easy change from a machine mode corresponding to a backhoe excavator to a machine mode corresponding to a loader excavator, and vice versa. [MEANS for Solving the Problem] Arranged are a hydraulic circuit 1 provided with hydraulic pumps 11-18 and directional control valves 21-35, solenoid valves 41-43, 51-66 for controlling hydraulic pumps 11-18 and the directional control valves 21-35, and a controller 70 for controlling the solenoid valves 41-43, 51-66 in accordance with operation of control lever devices 80-83 and control pedal devices 84-87. The controller 70 performs control of the solenoid valves 41-43, 51-66 in a backhoe mode or loader mode selectively instructed by a mode instruction means 71. Control of the solenoid valves 41-43, 51-66 in the backhoe mode makes the hydraulic circuit 1 function as a hydraulic drive circuit for backhoe, while control of the solenoid valves 41-43, 51-66 in the loader mode makes the hydraulic circuit 1 function as a hydraulic drive circuit for the loader mode.
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