| 摘要 |
PURPOSE: An automatic transfer control system of a ladder truck is provided to perform safe and prompt work by minimizing manual operation dependent on the naked eyes and experience of a worker. CONSTITUTION: A ladder truck has a multi-stage boom(11) and a transfer stand(12) driven by winch units(10,20). A withdrawing unit has a pair of main wires connected to the winch unit by passing through the members of the boom and an auxiliary wire connected with upper and lower members. Limit switches(21,22) are installed in the uppermost member and the lowest member of the boom to detect the movement process of the transfer stand. A count switch(23) installed in the winch unit for driving the transfer stand detects the movement distance. A hydraulic drive unit having a hydraulic pump, a proportional control valve and a hydraulic motor provides the winch units with a driving force. A controller(30) inputs the signals of the limit switches and the count switches and varies the speed of the transfer stand by outputting signals to the proportional control valve. Herein, the transfer stand on the boom is driven smoothly in a predetermined mode.
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