Quick following control method for lifting motor and opening and closing motor of grabbing crane

Abstract

The invention relates to a quick following control method for a lifting motor and an opening and closing motor of a grabbing crane. The quick following control method includes steps that when a grab bucket fully grabs materials and is closed, the opening and closing motor is switched to a torque control mode with fixed torque so as to run in a deceleration manner at the set torque; simultaneously, the lifting motor works in a speed control mode with fixed rotation speed and is driven to accelerate to set speed; and when the running distance of a draw cord of the lifting motor is equal to that of a draw cord of the opening and closing motor, the opening and closing motor is switched to a speed control mode, and the lifting motor is switched to a torque control mode so as to follow the torque of the opening and closing motor. The working modes of the opening and closing motor and the lifting motor are controlled, accordingly, when the draw cord of the lifting motor is tensioned straightly to carry load, the opening and closing motor is in a torque limit state, overload of the opening and closing motor is avoided assuredly, the opening and closing motor is driven to run in the deceleration manner, and simultaneously, the lifting motor is in a quick acceleration state until the running distances of the two motors are identical.

Description

technical field [0001] The invention relates to a grab crane, in particular to a balanced control system and method for preventing overload of a switch motor. Background technique [0002] With the continuous popularization of frequency conversion technology, its various advantages have been gradually recognized by everyone, so frequency conversion control has also been applied to grab cranes in recent years. But there is a problem in use, that is, because the working efficiency of the grab crane is relatively high, after the material is grabbed in the past operation, the opening and closing motor will be stopped, and then the two handles will work together, which will greatly improve the efficiency. Therefore, in many cases, after the opening and closing mechanism of the grab completes the grabbing work, it does not stop, and directly starts the lifting motor to improve efficiency. [0003] However, in the existing control method, the switching motor and its mechanical tra...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a fast following control method for the lifting motor and the opening and closing motor of the grab crane, which is used to solve the problem that the opening and closing motor in the prior art is in an overload state during the lifting process, which is not conducive to safe operation

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