| 摘要 |
PROBLEM TO BE SOLVED: To prevent occurrences of impact during starting and stoppage of a cargo receiving platform. SOLUTION: This cargo receiving platform elevating device 10 is provided with a lift member 11 supported by a load-carrying platform 2, a load receiving platform 12 supported by the lift member 11, a lift cylinder device 15 elevating the lift member 11, and an oil passage 19 supplying pressure oil of a hydraulic pump 17 to the lift cylinder device 15 and draining it therefrom, and a valve 23 for lifting controlling the lift cylinder device 15 is interposed in the oil passage 19 to the lift cylinder device 15. A drain oil passage 27 conducting the pressure oil of the hydraulic pump 17 and the pressure oil of the lift cylinder device 15 to a tank 18 is branched from the oil passage 19, and a flow proportional valve 28 is interposed in the drain oil passage 27. By this, a drain flow rate of the lift cylinder device is gradually increased by the flow proportional valve for gently starting in a lowering operation initial stage and a supply flow rate of the lift cylinder device is gradually decreased by the flow proportional valve for gently stopping in an operation terminal stage for preventing impacts during starting and stoppage of lowering of the load receiving platform.
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