Method for switching positive roller and negative roller of working roll

Abstract

The invention discloses a method for switching a positive roller and a negative roller of working rolls. A plurality of roller cylinders are arranged between roller bearings at the left side and the right side of an upper working roll and a lower working roll, a bearing block is movably connected with the roller cylinders, and a gap is kept between the heads of the roller cylinders and T-shaped slots in the roller bearings; the roller cylinders at the left side and the right side of the working rolls are classified into two groups, each group of working rolls are respectively controlled by an independent roller regulator, the two groups of roller cylinders and respective roller regulators form two regulating loops; and set values are selected for the two roller regulators to guarantee that at least one group of roller cylinders are in 'opening' or 'tensioning' state and the total roller force is equal to a process set value as required in the whole working range of the roller force. By adopting the method disclosed by the invention, the roller cylinders can be ensured to be tightly contacted with the bearing block, and uncertain 'free' state between the upper and lower working rolls can be eliminated. Meanwhile, gapless smooth switching between the positive roller and the negative roller is realized.

Description

technical field [0001] The invention relates to a metallurgical technology, in particular to a method for switching positive and negative bending rolls of work rolls. Background technique [0002] In various rolling mills of metallurgical factories, in order to control the shape of strip steel or steel plate, the common method is positive and negative roll bending control of work rolls, among which, the positive and negative bending switch function of work rolls is essential. [0003] The existing positive and negative bending roll switching device includes a group of bending roll oil cylinders, and the roll bending oil cylinders are arranged between the bearing seats on the left and right sides of the upper and lower work rolls. Usually, four bending oil cylinders are respectively arranged on the left and right sides of the work roll, and the four bending oil cylinders are respectively located on the four corners of the bearing housing. [0004] When the cylinder heads of ...

AI Technical Summary

Problems solved by technology

When the oil cylinder is in the idle stroke period, because the cylinder head of the bending roll cylinder is separated from the bearing seat at this time, the upper and lower work rolls are in a "free" uncertain state. At this time, the oil pressure in the bending roll oil cylinder cannot represent the bending roll. As a result, the bending force cannot be measured correctly, and the bending regulator cannot be normally closed-loop controlled.

In addition, due to the existence of gaps, the bending force of the work rolls still has impact after switching, which causes mechanical damage to the cylinder head of the bending cylinder

These often lead to strip deviation and broken strip accidents during steel rolling.

Also the same problem occurs when the work rolls are switched from negative to positive bend

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