| 摘要 |
PROBLEM TO BE SOLVED: To improve the efficiency of the cargo lifting work of a cargo deck lifting device. SOLUTION: The cargo deck lifting device 10 has left and right lift valves 28 and 26 for controlling left and right lift cylinder devices 15L and 15R for lifting a lift arm 11 to which the cargo deck 12 is rotatably journaled, and left and right tilt valves 27 and 25 for controlling left and right tilt cylinder devices 14L and 14R for rotating the cargo deck 12. A speed increasing valve 29 is connected to the left lift valve 28 and the left tilt valve 27. The speed increasing valve 29 is structured to connect the left lift valve 28 and the left tilt valve 27 to a tank 18 via a tank oil path 47 when the cargo deck 12 is opened/closed or when no load is applied. Accordingly, as only the right tilt cylinder device or the right lift cylinder device is operated by switching the speed increasing valve when the cargo deck is opened/closed or when no load is applied to increase the speed, the redundant time in the work of the cargo deck lifting device is reduced and the efficiency of the cargo lifting work is improved. COPYRIGHT: (C)2003,JPO
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