JPS58199611A - Rolling method of off-gauge part - Google Patents

Abstract

PURPOSE:To improve the accuracies of the length and thickness of an off-gauge part, by changing the sheet thickness at the top and bottom parts of a coil during rolling, and performing the rolling by combining a schedule calculation for obtaining the target sheet thickness and an AGC in absolute value of a whole stand. CONSTITUTION:The length of an outer peripheral portion of one turn is calculated by turns of rolled coils by inputting a coil information about the thickness, the width, the weight, and the coil thickness, etc. of a sheet to be rolled, and the result is used as the target off-gauge length. The off-gauge length is used in calculation as the length at the inlet side of one stand, and is used for a changing point of the sheet thickness during rolling. For changing the sheet thickness in actual rolling, a rolling draft, the number of revolutions, an AGC in absolute value are set up and a change of setting of a thickness gauge is performed by tracking the changing point of the sheet thickness during rolling. In a case when a sheet is free from tension at the front or rear side of each stand by the condition of biting or passing through of the sheet resulting from passing or run-out of the sheet at said stand, a schedule calculation is performed so as to obtain the target sheet thickness. Two kinis of the target sheet thickness at the middle and the off-gauge parts may be required.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an off-gauge rolling method for accurately rolling the first part and the second part of the bottom part of a coil.

Coil rolled in a cold tandem mill.

The bottom part and the bottom part are usually cut off in the final process of the outermost and innermost peripheries due to the occurrence of handling flaws or stains during annealing. Therefore, thick feathers are no good! , it is preferable in terms of trade to roll the metom part thinly. On the other hand, in the case of thin materials, if there is no thick off-glue 2 part in the trough 1 part, the inner diameter will collapse, so it is better in terms of total yield to make the t, f, z tom parts thicker.

By the way, the rolling schedule of a cold tandem mill is calculated for the middle part where forward or backward tension is generated in the rolled material, and the rolling amount and number of turns of each stand are determined. However, since no forward or backward tension is generated during sheet threading and ash removal, thick off-dage tends to occur.

Therefore, in the past, threading and ash removal were sometimes done by tightening the reduction based on a table calculated in advance.
Although attempts are made to prevent the occurrence of thick off-gauge, there is a problem with accuracy.

Since there is a relative variation in thickness at the top and bottom of the plate, an AGC device is used to control this. However, conventional AGC devices are lock-on types,
Control is carried out to ensure that the thickness is the same as when it is turned on, but there is no guarantee that this is the target thickness.

In other words, in the conventional technology, in order to improve yield, ! and-
There has been no technology for consciously and accurately controlling the thickness and length of the thin and thick off-ditch parts of the tom part.

The object of the present invention is to provide an off-dage rolling method that can accurately roll the length and thickness of the truncated off-durge parts of the coil (), 7'', &).

The off-dage rolling method of the present invention is characterized by changing the plate thickness during running at a predetermined length point at the top and tom parts of the coil, and changing the target plate thickness when there is no tension in the front or rear of the threading or tailing. Aim schedule calculation and absolute value of all stands A
It is rolled in combination with GO.

An embodiment of the method of the present invention will be described below using an apparatus shown in a block diagram. This device is composed of the following three products.

1) A professional who changes the running plate thickness at the length of one outer turn at the top and tom portions of a rolled coil.

2) Schedule calculation professional to aim for the target plate thickness tube in the on/off state of each stand for threading and K removal.

3) 10. Absolute value AGC device that has a full-stand plate thickness controller and controls toward the target plate thickness at the start of control. the law of nature.

In the rolling sheet thickness change pro, the coil information sound such as the thickness, width, weight, and winding thickness of the original sheet is input, and the length of one outer circumference is calculated in the order of the rolling coil. do. This target off-gauge length t - original plate thickness is calculated as the entry side length of one stand, and is used as the plate thickness change point during running. During actual rolling, the draft of each stand, advance rate, work roll diameter, work roll rotary cover, and plate thickness change point during rolling are checked, and the rolling and rotation speed settings are set to change the plate thickness. Door to absolute value AGC! and change the setting of the thickness needle.

Schedule calculation! The lock is used to calculate the schedule and rule so that the target thickness is achieved when there is no forward or backward tension in the stand engagement and extraction states for threading and shearing, and the target thickness is the thickness of the middle part of the plate. , stuttering occurs when there are two types of off-dage target thickness. The timing of threading and stripping is determined by each stand's cutting and stripping judgment. In the figure, the target thickness of the i, l+1 stand is scaled to the off-dage thickness.

BISRA AGC is a professional absolute value AGC device.
Using t as an example, the plate thickness is h = s + δ. , is ten δ. 1.・・・・・・
.........It is expressed as (1). ζS here;
Reduction position, P: electric charge, M: Le constant, δ ° oil film thickness,
δo22; offset o1t'' weight.

Therefore, the oil film thickness δ can be determined from the roll rotation speed. Estimate it.

The thickness ht of the plate during roll bite is determined from the detected load P, and control is performed so that the target plate thickness is achieved.

This target plate thickness can be changed between the off-goo 9 section and the middle section by changing the plate thickness during running.

Additionally, in this AGC device, an offset amount a is used to improve accuracy. 1. It has a learning function. The exit plate thickness of each stand is calculated from the mass flow set from the thickness gauge measurement value, work roll diameter, and roll rotation speed of the rolling performance data of the previous par or main par, and the rolling height tIt8 of the other rolling performance data is calculated.
, the offload weight δ is obtained from equation (1) using the load P'ft. F
Ft-Find. And this offset amount a. 2. The accuracy can be improved by correcting and controlling.

The off-dage rolling method of the present invention is as described above, and the length and thickness of the coil track f,'&)5 parts are cut off and the off-dage parts are cut off by 9 parts. # Can be rolled well. Therefore, the total yield can be improved.

[Brief explanation of drawings]

The drawing is a schematic diagram showing an embodiment of an apparatus for carrying out the method of the present invention.

Claims (1)

[Claims] In addition to changing the board thickness during running at a predetermined length at the tow and tom parts of the coil, schedule calculations to aim for the target board thickness when there is no forward or backward tension during threading and ash removal, and absolute standards for all stands. Rolling in combination with the value AGC
Off-gauge rolling method with % mold.