Roll breakage protecting control method for working roll of heavy and medium plate mill

Abstract

The invention discloses a roll breakage protecting control method for a working roll of a heavy and medium plate mill, which comprises the following steps: additionally arranging two pressure sensors at a driving side and an operating side on an AGC control hydraulic valve stand; transmitting detected signals of pressure intensities to a mill control PLC; obtaining the pressures of an AGC cylinder by respectively multiplying the pressure intensities detected by the two pressure sensors by the area of the AGC hydraulic cylinder by the PLC, wherein the pressures of the AGC cylinder are respectively the pressures acting on two sides of the working roll; comparing the calculated two pressures of the two sides of the working roll respectively with force detected by a piezomagnetic head; and when the comparison result is larger than 800T, considering that the working roll of the mill is abnormal currently, immediately stopping the current action, and opening a roll gap quickly to protect the working roll. The invention takes the detected deviation value of actual forces of an upper roll and a lower roll as a controlled object, limits the actions of the upper roll and the lower roll, avoids breakage of the working roll, and can effectively protect the working roll when the mill has abnormal conditions, thereby preventing the roll breakage.

Description

technical field [0001] The invention relates to an equipment protection control method in a medium and thick plate rolling mill in the metallurgical industry, in particular to a protection control method for preventing work roll breakage of a medium and heavy plate rolling mill with an AGC cylinder placed below. Background technique [0002] At present, the AGC (automatic thickness control) hydraulic control of the medium and heavy plate mill is divided into two types: upper and lower. The roll gap control of the lower AGC cylinder is controlled by the position sensor of the upper roll (electric pressing) and the lower roll (hydraulic pressure). Below) the position sensor to feedback, and the pressure control is based on the principle of force interaction, mostly detected by the magnetic head at the end of the electric screw rod distributed on both sides. The disadvantage of this structure is: when there is a problem with any of the displacement sensor or the pressure head, ...

AI Technical Summary

Problems solved by technology

The disadvantage of this structure is: when there is a problem with any of the displacement sensor or the pressure head, the detection will be inaccurate, and the system will be controlled according to the wrong feedback, which will cause the work roll to move to the limit position and the load on the roll surface Excessive force and uneven force across the entire roll surface, resulting in breakage of the work roll

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