Protection method and system for lifting device band-brake failure

Abstract

The invention discloses a protection method for lifting device band-brake failure. The method comprises the steps that a feedback signal which characterizes a band-brake state of a band brake is received; whether the feedback signal is normal or not is judged, if yes, a first control signal is output, a zero servo is started, and a load is held by outputting moment of force at zero speed; whether time for starting the zero servo reaches a first preset value or not is judged, if yes, a second control signal is output, the zero servo is stopped, and the load is dropped down at a certain speed; whether a dropping height meets a second preset value or not is judged, if yes, the step of outputting the first control signal is returned, the steps are repeated till it is judged that the loaded dropping height does not meet the second preset value, and control is finished. According to the protection method for the lifting device band-brake failure, weight dropping can be avoided, a weight can be slowly put on a safe position, and excessive impact to damage the weight is avoided. The invention further discloses a protection system for the lifting device band-brake failure.

Description

technical field [0001] The invention relates to the technical field of brake safety protection for a lifting device, in particular to a protection method and system for a brake failure of a lifting device. Background technique [0002] At present, in the lifting industry, such as cranes, tower cranes, etc., heavy objects (such as goods) are often lifted. After reaching a certain height, the brake will be controlled to suspend the heavy object in the air, and then move in the horizontal direction . The holding brake is the guarantee of system safety. Once the holding brake fails, the phenomenon of sliding hook will occur, causing heavy objects to slide down, which poses a great safety hazard and directly threatens the lives of surrounding staff. Therefore, in order to improve the safety of the system, there must be a reasonable and effective method to prevent the hook from slipping and the heavy objects from falling quickly after the brake brake fails. [0003] As for the p...

AI Technical Summary

Problems solved by technology

[0003] As for the protection method for the failure of the brake brake, some manufacturers have proposed at present. If the method of some manufacturers is that when the brake fails, the inverter is used to control the motor to go down at a low speed, and at the same time output a certain torque. Shutdown, this method can play a protective role to a certain extent, but because the heavy object is lowered at a certain speed, when the heavy object is lowered to a certain end position (such as the ground), a certain impact cannot be avoided. When the weight is heavy, the inertia will be greater, and the impact may be too large to cause damage to the item; there is also a manufacturer's method that when the brake fails, the inverter directly uses the zero-servo function to hang the heavy object in the air. Although this method can be used immediately Prevent the hook from slipping when the brake brake fails, but you can’t hang the heavy object in the air all the time, there will be safety hazards. At the same time, considering the heat dissipation of the low-frequency inverter and the motor, the zero-servo running time cannot last too long. If it continues Zero servo output to drag heavy objects, it is likely to burn out the inverter or motor

Images