| 摘要 |
PROBLEM TO BE SOLVED: To provide a control device of a hydraulic drive winch capable of preventing slack of a rope when a lifted load is landed on a floor. SOLUTION: In the control device of the hydraulic drive winch W, a first pressure oil supply/discharge passage 2 and a second pressure oil supply/discharge passage 4 are respectively communicated with a first port 1a and a second port 1b of a hydraulic motor 1 driving a drum D of the hydraulic drive winch W from a switching valve 7 switching pressure oil discharged from a hydraulic pump 8. Furthermore, the control device of the hydraulic drive winch W includes a first pressure sensor GP<SB>1</SB>detecting the rope hoisting pressure of the first pressure oil supply/discharge passage 2, a second pressure sensor GP<SB>2</SB>detecting the rope lowering pressure of the second pressure oil supply/discharge passage 4, and moreover, a switching valve operation detector detecting the operation of hoisting/lowering of the switching valve 7. It further includes a controller calculating a difference in pressure detected by the first and second pressure sensors GP1, GP2 when the hydraulic motor 1 is rotated in the rope lowering direction by the switching valve operation detector, time-differentiating the pressure difference, and moreover, issuing a winch stop signal when a time differential value exceeds a preset reference value. COPYRIGHT: (C)2011,JPO&INPIT
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