Control method for preventing hook from slipping when electric hoist stops

Abstract

The invention discloses a control method for preventing a hook from slipping when an electric hoist stops. The electric hoist is driven by a tapered motor, a control system of the tapered motor is a frequency converter comprising an inversion unit and a control unit, and the control unit comprises a magnetic chain controller and a torque / torque current controller. The tapered motor also comprisesan electromagnetic contacting brake device. The control unit controls the inversion unit to stop output, so that the control unit controls the inversion unit to carry out demagnetization processing on the tapered motor after the tapered motor is powered off. With the control method, remanent magnet in the tapered motor is reduced to a degree that the action of the electromagnetic contacting brakedevice in the tapered motor cannot be hindered, the hook slip phenomena of the electric hoist can be effectively avoided, the locating accuracy of heavy objects in the air is improved during the use of the electric hoist, the standard requirements of the electric hoist industry are met, and the use safety is improved.

Description

technical field [0001] The invention relates to a control method of an electric hoist, in particular to a control method for preventing the hook from slipping when the electric hoist driven by a conical motor stops. Background technique [0002] With the development of frequency conversion technology, frequency converters have been gradually applied to lifting equipment due to their energy-saving and high-efficiency features, among which there are more typical electric hoists for lifting. [0003] The electric hoist has a simple structure and is widely used. Most of the existing electric hoists use conical motors with special structures. The characteristic of the conical motor is that it integrates power and braking force. The inner circle of the stator core and the outer circle of the rotor core of the motor are designed as conical surfaces. The electromagnetic brake is the brake ring on the inner circle of the motor fan, which is located on the motor shaft. At one end, th...

AI Technical Summary

Problems solved by technology

Therefore, the electromagnetic force between the stator and the rotor in the motor will not disappear immediately, but will gradually decay according to a certain time constant, which will inevitably hinder the braking action of the brake, resulting in the hook slip phenomenon

The sliding hook phenomenon not only reduces the accuracy of the positioning of heavy objects in the air, but also sometimes causes serious safety problems. Therefore, anti-slipping hook is a key issue for the application of frequency converters in conical motor electric hoists.

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