| 摘要 |
PROBLEM TO BE SOLVED: To provide a hydraulic shovel capable of restraining over-revolution of an engine.SOLUTION: The working machine comprises: an engine 7; a closed circuit 108 having a second hydraulic pump 10 in the engine 7, an arm cylinder 3 driven by working oil emitted from the second hydraulic pump 10, a proportional control valve 34 for generating load pressure to an emission side of the second hydraulic pump 10, an accumulator 36, and a flow passage switch part 109 for switching a flow passage of the working oil emitted from the second hydraulic pump 10 to any of the arm cylinder 3, the proportional control valve 34, and the accumulator 36; a closed circuit 107 having a first hydraulic pump 9 that is driven by the engine 7 and whose emission flow rate and emission direction can be controlled, and a boom cylinder 1 driven by the working oil emitted from the first hydraulic pump 9; and a power transmission device 8 for transmitting power of the first hydraulic pump 9 to the second hydraulic pump 10. |
