Safety protecting method and safety protecting device for boarding bridge traveling system

Abstract

The invention relates to a safety protecting method and a safety protecting device for a boarding bridge travelling system. The boarding bridge traveling system comprises traveling wheels, a traveling motor, a frequency converter, an operating handle and a PLC (programmable logic controller) system. The safety protecting method is characterized by including the steps of setting a threshold current value in the frequency converter; arranging a signal element on the frequency converter; outputting an overcurrent signal to the PLC system by the signal element when the current value of the traveling motor reaches the threshold current value; judging that a brake of the traveling motor is not released if the overcurrent signal still exists within a period of time after the PLC system issues a brake releasing command to the travelling motor, and enabling the PLC system to issue stopping signals to stop the operation of the traveling motor and stop releasing the brake. The safety and the reliability of the boarding bridge traveling system can be increased by the PLC system.

Description

technical field [0001] The invention relates to a boarding bridge, in particular to a safety protection method and device for a walking system of a boarding bridge. Background technique [0002] At present, the walking is an electromechanical and hybrid boarding bridge driven by electromechanical. Its walking system usually includes walking wheels, walking motors, frequency converters, operating handles and PLC control systems, and its walking speed control is controlled by frequency converters. . The frequency converter has fault detection and judgment functions: it can detect faults such as phase loss, undervoltage, and overvoltage of the input line; it can detect transmission faults from the power output terminal of the frequency converter to the motor line, such as wrong phase, Fault without electricity; it can detect motor faults, such as motor coil burnout, short circuit, and open circuit faults. [0003] However, the limit value of the overcurrent protection in the ...

AI Technical Summary

Problems solved by technology

like Figure 2B As shown, it is a schematic diagram of the electromechanical four-wheel drive left left travel motor without releasing the brake. When the left left wheel motor is not released in time, the wheel frames 23 and 26 will walk left according to the left side of the brake. The wheel 21 rotates as the axis, and at this moment, the bridge that was originally advancing or retreating becomes a phenomenon that the left traveling wheel turns on the left side.

like Figure 2C As shown, it is a schematic diagram of an electromechanical four-wheel drive right side traveling motor that does not loosen the brake. The road wheel 24 rotates as the axis, and at this moment, the bridge that was originally advancing or retreating becomes a phenomenon that the right road wheel turns on the right side.

[0007] Therefore, although the phenomenon that the motor brake on one side cannot be released with the control is less likely or almost never occurs, the blind area of ​​the protection function of the frequency converter will still cause potential safety hazards in the walking system of the boarding bridge

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