| 摘要 |
PURPOSE:To roll up a hose by operating an arm only by a method in which a circuit to shorten an arm having a clamshell bucket at its tip is branched, and an oil-pressure motor to roll up a hose and to operate the bucket is operated at the branched circuit. CONSTITUTION:When a switch valve 19 is switched from neutral position to right position by an operator and an expandible arm 2 is contracted, an oil- pressure cylinder 5 and he expandilbe arm 2 are contracted through a pipeline 20. In this case, working oil flows from a port P1 even into an oil-pressure motor 16 through a pipeline 24 with a check valve 23, the oil-pressue motor 16 turns in the direction of winding the hose, and the hoses 11 and 12 of the working cylinder 10 of a bucket 8 are rolled up, whereby preventing the loosening of the hoses. On the contrary, when the oil-pressure cylinder 5 and the expandible arm 2 extend, the oil-pressure motor 16 serves as a pump, oil is circulated in a close circuit of the pipeline 26 with an oil tank 27, the pipeline 28, the oil-pressure motor 16, the pipeline 24, and a relief valve 25, and the inertial rotation of the stoppage of the motor 16 is prevented by the valve 25. |
