| 摘要 |
PROBLEM TO BE SOLVED: To provide a lifting device that removes a problem in which the device cannot operate by the trip stop of an inverter device, prevents superheating in a damping resistor by decreasing an energization ratio per prescribed time or the amount of energization current (amount of integral current) to the damping resistor before the damping resistor is superheated, and can improve the operating efficiency of the device. SOLUTION: The lifting device comprises a lift mechanism consisting of a reduction mechanism 3 and a load winding device 4, an electric motor 2, an inverter device 1, and the damping resistor 9, and raises and lowers a load 5 at a predetermined set speed by the lifting mechanism, and supplies power generated by the electric motor 2 in descending to the damping resistor 9 for performing regeneration damping. In the lifting device, a means for detecting the energization ratio per predetermined time or the amount of energization current (amount of integral current) per predetermined time is provided, the rotational speed of the electric motor 2 is controlled via the inverter device 1 when the energization ratio or the amount of energization current exceeds a prescribed fixed value, and the descent speed is reduced or both the descent speed and ascent speed are reduced. COPYRIGHT: (C)2005,JPO&NCIPI
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