A tension control method for preventing strip deviation in a looper

Abstract

The application discloses a tension control method for preventing strip deviation in a loop, which comprises the following steps: when starting production, an entry production speed range is 60-700 m / min; a tension control range is 228 kg-8355 kg; a loop amount of the loop is gradually increased from 5% of an empty loop to 85% of a full loop; a process section speed range is 30-270 m / min, and the loop amount is between 80% and 90%; when the strip on the entry uncoiler is lower than 30 m, entry tailing follow-up control is triggered, the speed of the entry section is reduced from the production speed to 60 m / min, and the tailing follow-up control is entered; when the tailing follow-up control is entered, the tailing tension is set to 95% of the set tension, the strip in the loop has no obvious shaking, the strip is stable and centered, and no deviation trend occurs. The application aims to provide a tension control method for preventing strip deviation in a loop, and realizes stable control of the strip in the loop.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of loop control of strip in cold rolling production rolling, and particularly relates to a tension control method for preventing strip deviation in a loop. BACKGROUND

[0002] The loop is an important equipment in cold rolling production, and its main function is to be used as a storage for the strip. The function of the inlet loop is to ensure the stable and continuous operation of the process section of the strip during welding by the welding machine, reduce the over pickling of the strip, and avoid defects such as parking spots. In the normal production process, in order to obtain a better pickling effect, the loop capacity should be as full as possible during production, and during the entry tailing period, the process section is normally operated, and there is almost no strip on the inlet uncoiler, so the tension in the loop will be reduced to 55% of the set tension, and during the tension reduction process, the strip in the loop is prone to deviation and edge scraping, causing accidents.

[0003] The cold rolling pickling mill group has various product specifications, and the loop filling control not only plays a role in adjusting the speed of the inlet speed, but also considers the influence of factors such as tension and deviation on the running stability of the strip. Therefore, the various product specifications increase the difficulty of loop deviation control, and thus a loop control method for preventing strip deviation is needed. SUMMARY

[0004] The purpose of the present application is to provide a tension control method for preventing strip deviation in a loop, and to realize stable control of the strip in the loop.

[0005] To solve the above technical problems, the present application adopts the following technical solutions:

[0006] The present application relates to a tension control method for preventing strip deviation in a loop, comprising:

[0007] When the vehicle is started, the inlet production speed range is 60-700 m / min with the speed command given;

[0008] The loop tension will quickly reach the set tension, and the tension control range is 228 kg-8355 kg, and the set tension is continuously and stably maintained;

[0009] As the inlet filling speed increases, the loop capacity gradually increases from 5% of the empty loop to 85% of the full loop;

[0010] The process section speed is increased, and the process section speed range is 30-270 m / min, the strip in the inlet loop is pulled out, and the loop capacity of the inlet loop is ensured to be a controllable nearly full loop position, and the loop capacity is between 80-90%;

[0011] When the strip on the inlet uncoiler is less than 30 m, the inlet tailing sequence control is triggered, the speed of the inlet section is reduced to 60 m / min from the production speed, and the tailing sequence control is entered.

[0012] The tailing tension is set to 95% of the set tension, the strip in the loop is not obviously shaken, the strip is stably centered, and the deviation trend does not appear.

[0013] Further, when the strip storage amount is ≥80% and the storage amount is ≤20%, the target state is the full load or empty load state of the strip loop.

[0014] Further, the strip steel is deep drawing steel, low carbon steel, medium carbon steel, low alloy high strength steel, dual-phase steel, zinc-aluminum-magnesium product.

[0015] Further, the strip specification is a finished product thickness of 0.25-2.5mm and a width of 800-1880mm.

[0016] Further, the main equipment involved includes an uncoiler, a laser welding machine, a loop, a loop car, a tension leveler, 1-3# tension rollers, 1-3# deviation correction rollers, and a turning roller.

[0017] Further, the process section speed range is 30-160m / min.

[0018] Further, the loop tension is stably kept at 4700kg during the stable speed production.

[0019] Compared with the prior art, the beneficial technical effects of the present application are:

[0020] The tension control method for preventing the strip deviation in the loop provided by the present application provides a means for preventing the strip deviation in the loop, the application range of the method basically covers most of the cold-rolled products (general steel, deep drawing steel, structural steel, low alloy high strength steel, zinc-aluminum-magnesium steel). By optimizing the tension control adjustment, the relaxation state of the strip in the loop during the entry tailing is effectively improved, the strip shaking caused by the strip fluctuation is reduced, the effective contact area of the strip on the loop roller is ensured, thereby the stability of the strip running is improved, and the production accidents are reduced. During the period, the loop and the matching equipment do not need to be modified or even replaced, the existing production conditions are utilized, the tension control of the loop during the production is optimized without changing the existing equipment, and thus the stable running of the strip in the loop is realized. BRIEF DESCRIPTION OF DRAWINGS

[0021] The present application will be further described below in combination with the description of the drawings.

[0022] Figure 1 is the deviation effect macroscopic morphology of the strip in the loop during the tailing in the prior art;

[0023] Figure 2 is the deviation effect macroscopic morphology of the strip in the loop during the tailing provided by the present application;

[0024] Figure 3 The curve feedback graph of the action of the loop correcting cylinder during the fishtailing in the prior art in the comparative example;

[0025] Figure 4 The curve feedback graph of the action of the loop correcting cylinder during the fishtailing provided by the application in the embodiment. DETAILED DESCRIPTION

[0026] The application will be further described in conjunction with the embodiments below, and the purpose is only to better understand the content of the application, and therefore, the examples do not limit the protection scope of the application.

[0027] The low carbon steel raw material with a thickness of 5.0 mm and a width of 1535 mm is uncoiled for production, specifically including the following steps:

[0028] (1) After uncoiling, automatic welding operation of the laser welding machine is performed.

[0029] (2) After welding, orderly acceleration is performed according to the interval of 100 meters / minute each time, until the speed is increased to 500 meters / minute for stable production.

[0030] (3) With the increase of the inlet loop filling speed, the loop volume gradually increases from 5% empty loop to 80% full loop.

[0031] (4) The loop tension is stabilized at 4700 kg during stable production.

[0032] (5) The process section speed is increased, and the process section speed range is 30~160 meters / minute, the strip steel in the inlet loop is pulled out, and it is ensured that the loop volume of the inlet loop is a controllable nearly full loop position volume≥80%.

[0033] (6) When the strip steel remaining on the inlet uncoiler is 30 meters, the inlet fishtailing sequence control is triggered, the speed of the inlet section is reduced from the production speed to 60 meters / minute, and the fishtailing sequence control is executed.

[0034] (7) The tension of the inlet loop during the fishtailing will be reduced. If the existing technology (comparative example) is used to set the tension to 55% of the production time, at this time, the strip steel in the loop starts to shake and the strip steel in the loop appears a deviation trend, the observation of the correction state is unstable, the correction shakes back and forth, see Figure 3 . The position deviation of the strip steel of 2# correction and 3# correction is distributed within ±1.5%, the oil cylinder position distribution range is large, and frequently reaches the limit value of the correction oil cylinder stroke, at this time, the correction ability is saturated, and the strip steel is prone to deviation problems.

[0035] According to the above (6) into the fishtailing sequence control. If the tension is set to 95% of the production time, at this time, the strip steel in the loop does not shake obviously, the strip steel is stable in the middle, and there is no deviation trend, and the observation of the correction state is stable. Figure 4 is the motion of the correction cylinder in this embodiment.

[0036] Compared with the comparative example, the strip position deviation of 2# correction and 3# correction is not much different from that before optimization, the cylinder displacement distribution is within 50 mm, which is greatly reduced compared with the previous one, and the cylinder stroke of correction is more stable than that before optimization, and the correction capacity is released.

[0037] The above-described embodiments are only to describe the preferred modes of the present application, and not to limit the scope of the present application. Without departing from the design spirit of the present application, various modifications and improvements to the technical solutions of the present application made by those skilled in the art shall fall within the protection scope determined by the claims of the present application.

Claims

1. A tension control method for preventing a strip from deviating in a loop, characterized by, It includes: When the production speed command is given, the entry production speed range is 60-700m / min; The loop tension will quickly reach the set tension, and the tension control range is 228kg-8355kg, and it will be kept at the set tension; With the increase of the entry loop speed, the loop volume gradually increases from 5% empty loop to 85% full loop; The process section speed is increased, the process section speed range is 30-270m / min, the strip in the entry loop is pulled out, and the loop volume is kept at a controllable nearly full loop position, the loop volume is between 80-90%; When the strip on the entry uncoiler is less than 30m, the entry tailing control is triggered, the speed of the entry section is reduced to 60m / min, and the tailing control is entered; When the tailing control is entered, the tailing tension is set to 95% of the set tension, the strip in the loop has no obvious shaking, the strip is stable in the center, and there is no tendency of running off.

2. The tension control method for preventing a strip from deviating in a loop according to claim 1, characterized by, The strip steel grade is deep drawing steel, low carbon steel, medium carbon steel, low alloy high strength steel and dual phase steel product.

3. The tension control method for preventing a strip from deviating in a loop according to claim 1, wherein The strip specification is finished thickness 0.25-2.5mm, width 800-1880mm.

4. The tension control method for preventing a strip from deviating in a loop according to claim 1, wherein The main equipment involved includes: uncoiler, laser welding machine, loop, loop car, straightening and leveling machine, 1-3# tension roller, 1-3# deviation correction roller, deflection roller.

5. The tension control method for preventing the strip from deviating in the looper according to claim 1, wherein The process section speed range is 30-160m / min.

6. The tension control method for preventing a strip from deviating in a looper according to claim 1, wherein The loop tension is stable at 4700kg during steady speed production.

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