Control method for dynamic falling of loop of hot continuous rolling mill

Abstract

The invention discloses a control method for dynamic falling of a loop of a hot continuous rolling mill. The control method comprises the following steps: 1, calculating the tail length of strip steel in front of the loop; step 2, performing secondary correction on the height of the loop, controlling matrix time, and tracking the accumulated length of strip steel operation; and 3, judging a dynamic loop falling starting point, and carrying out loop falling after conditions are met. According to the method, different loop heights are combined, loop dynamic loop falling control is adopted, and the loop stability of the strip steel in the steel throwing process is greatly improved through the strip steel operation accumulated length control technology, the loop height secondary correction technology and the matrix time control technology.

Description

technical field [0001] The invention relates to a control technology for looper drop-off of a hot continuous rolling mill, and more specifically relates to a dynamic drop-off control method of a hot continuous rolling mill looper. Background technique [0002] Loopers are installed between the finishing mills of today's hot continuous rolling production line, and its purpose is to ensure that the strip steel between every two rolling mills has a specific tension. The looper uses an extra tension to prevent the narrowing of the strip. Excessive tension will cause the strip to break. This situation occurs when the flow of the rear rack is greater than that of the front rack, that is, the speed of the rear rack Greater than the front frame, when the flow of the rear frame is smaller than that of the front frame, the strip will be folded, and the looper will be lifted at this time, otherwise it will cause abnormal belt threading. [0003] In this way, it is necessary to install...

AI Technical Summary

Problems solved by technology

However, when the upstream frame throws steel, the overall tension of the strip decreases, and the magnitude of the decrease increases with the increase of the steel throwing frame. The increase in the speed at the rear of the frame further aggravates the loss of tension, causing the strip steel to flick, unfinished, or even deviate from the pile of steel in the rear frame.

The existing looper control is often unable to fully compensate for the loss of tension caused by various reasons, resulting in the drifting, unfinished, or even deviation of the steel strip in the rear rack;

[0010] 2) The tail of the strip steel is narrowed

When the tension between the racks is too large due to abnormal factors, the main control speed intervenes to adjust the speed increase of the front rack, resulting in a rapid increase in the metal second flow of the front rack, and the rapid adjustment of the looper causes the angle to be too low after the overshoot. It will cause the tail of the strip to fail to form an effective transition, resulting in the phenomenon of the tail flicking after the front rack throws steel, which will have a serious negative impact on the stable rolling of the rear rack, and easily cause the tail to be broken;

[0012] 4) Scratches on the lower surface of the strip steel tail

Severe looper angle control at the tail of the strip will cause scratches on the lower surface of the strip;

[0013] 5) Roller surface damage and abnormal wear of the looper roller

Tail tension caused the tail to fold into the rear frame, causing scrap in the rear frame

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