JPH07314024A - Method for controlling edge drop of metal sheet in cold rolling - Google Patents

Abstract

PURPOSE:To effectively reduce an edge drop, to improve a quality, and a yield by measuring the profile of a metal sheet on an inlet side of a first stand, and shifting the work roll of a rolling mill in the roll shaft direction according to a measured result. CONSTITUTION:Crowns tapering by at least three steps toward edges, are given at edge parts on one side of work rolls 2 and 3, and a pair is made by the upper and the lower into which these tapered edges are assembled alternately so that they are in point symmetry. When a metallic sheet l is cold-rolled, the profile of a base material is measured by an edge profile meter 6 installed on the inlet side of a first stand. Also, the shift position of the roll, is calculated by a shift position arithmetic unit 7 according to the signal of a position detector 8. Based on this result, a shift device 12 is allowed to work. Consequently, a product with high accuracy, can be attained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is intended to improve quality and yield by effectively reducing edge drops which may occur during cold rolling of thin steel sheets.

[0002]

2. Description of the Related Art In cold rolling, a phenomenon in which the plate thickness sharply becomes thinner at the edge portion of a plate material than at the central portion due to a rapid recovery of work roll flatness and a metal flow in the width direction of the rolled material The so-called edge drop occurs.
If this edge drop is large, it is not possible to obtain a uniform plate thickness in the plate width direction, so it is necessary to increase the edge cutting margin in order to ensure the desired quality, and as a result, the yield and production efficiency are reduced. To be forced.

Conventionally, in order to reduce the edge drop, a roll bending method, a method of giving an initial crown to a work roll, or the like has been adopted. In addition, a method in which a simple tapered crown is applied to the end of the roll, the work roll is shifted in the axial direction of the roll, and the edge of the plate is rolled by this taper (Japanese Patent Laid-Open No. Sho 5)
No. 5-77903), a method in which a two-step taper or two-step large and small crowns are provided at the end of the roll, which is an improvement of this method (JP-A-61-186003), and a mother plate coil ( A method (Japanese Patent Publication No. 62-244506) of adjusting a work roll shift amount and a roll bender force which are tapered based on a profile measurement value of a hot coil is known.

[0004]

When the edge drop of the sheet material is controlled by applying the above-mentioned conventional method, it occurs in cold rolling under the condition that the crown of the mother sheet (hot coil) is relatively small. It was possible to control the edge drop to some extent. However, in hot rolling, the profile of the plate changes for each coil (1 cycle) due to the thermal crown of the roll, wear of the roll, etc., and a small plate crown (for example, a plate thickness difference between the edge 25 mm position and the plate width center) Since it is not possible to supply a defined amount of coils, there were the following problems.

For example, a coil with a large hot crown (a crown with a 25 mm edge is 40 μm or more) is used in a conventional work roll having a one-step or two-step taper, and the edge drop is controlled under the condition that the shift amount is relatively small. When this is done, a gouged portion is generated at the starting point of the tapered portion, and the ear from the inside including this gouged portion is forced to be cut, and the yield is reduced.

Further, in order to control the inner profile of the plate material, if the work roll shift amount is increased and the edge drop control is performed, the internal mother plate crown can be controlled, but the linear expression The one-step taper indicated by means has a drawback that the edge-up amount at a position slightly inside the both edges is large, and a uniform profile cannot be obtained in the plate width direction. Further, when a work roll having a two-step taper was used and rolling was performed with a large shift amount, the controllability of the edge portion was insufficient, and thus a uniform profile could not be obtained in the strip width direction. .

Further, in the longitudinal direction of the hot coil as well, the rolling load changes due to changes in deformation resistance due to temperature changes due to skid marks on the sheet bar in the hot finish rolling mill, plate thickness deviations, changes in rolling speed, etc. Changes greatly. It is extremely difficult for a normal cold rolling mill to correct the profile change caused by these hot rolling.

Using a conventional work roll having a one-stage or two-stage roll crown, the work roll is shifted based on the measurement result of the edge profile meter on the entry side of the cold rolling mill to control the profile over the entire width of the strip. In the case of, even though the profile of the central region of the plate material can be controlled, it is not possible to control the vicinity of the edge as described above, therefore, it becomes difficult to obtain a product having a uniform plate thickness distribution in the coil, It was unavoidable that the margin for ear cutting was large. Furthermore, even with the method of performing so-called feedback control based on the measurement result by the edge profilometer installed on the output side of the rolling mill, the crown shape given to the end of the work roll is not appropriate, so a uniform product in the width direction is obtained. I couldn't get it.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to propose an edge drop control method in cold rolling which can reduce the edge drop caused by cold rolling of a sheet material and improve the quality and yield. It is in.

[0010]

That is, the gist of the present invention is as follows. 1. A rolling roll is provided on one end of the rolling roll, which is tapered in at least three steps toward the outermost end, and the work rolls are paired up and down in a staggered manner so that the tapered ends are point-symmetrical. When performing cold rolling of a strip using a row of tandem rolling mills, measure the profile of the strip at the entry side of the first stand, and shift the work roll of the rolling mill in the roll axis direction based on the measurement result. A method for controlling edge drop of a plate material in cold rolling (first invention), comprising:

2. In the above-mentioned first invention, the shape of the crown applied to one end of the rolling roll is represented by a taper represented by a three-stage linear expression, and the second taper angle is the inner first And an outer third taper angle that is smaller than the third taper angle (second invention).

3. In the first invention, the shape of the crown applied to one end of the rolling roll is represented by a higher-order function of a cubic expression or higher or a triangular function and a linear expression. 3 invention).

4. In the above first, second or third invention, the shift change amount (ΔS ₁ ) of the work roll is expressed by the following equation (1),
An edge drop control method (fourth invention) for minimizing the value of J ₁ shown in (2). _{eh n (X) / h n} = (P (X, T) × G (X, S 1 + ΔS 1) + EH (X)) / H --- (1) J 1 = | Ec (X) - ( eh _n (X)) | ² --- (2) where Ec (X): target edge drop amount, eh _n (X)
: Predicted edge drop amount, X: board width direction coordinate,
P: Transfer rate, EH: Mother plate edge drop amount, G: First stand taper amount, H: Mother plate width center plate thickness,
h _n : product width center thickness, S ₁ : current shift amount,
ΔS ₁ : Shift change amount, eh _n : Product edge drop amount

5. A rolling roll is provided on one end of the rolling roll, which is tapered in at least three steps toward the outermost end, and the work rolls are paired up and down in a staggered manner so that the tapered ends are point-symmetrical. When performing cold rolling of the plate material using the tandem rolling mill row, the profile of the plate material is measured at the entry side of the first stand, and the work roll of the rolling mill is shifted in the roll axis direction based on the measurement result. Further, a method of edge-drop control of a plate material in cold rolling, characterized in that the profile of the plate material is measured even on the exit side of the final stand, and the work roll shift amount is corrected based on the measurement result (fifth invention).

6. In the fifth aspect of the invention, the shape of the crown applied to one end of the rolling roll is represented by a taper represented by a three-stage linear equation, and the second taper angle is the first inner side. And an edge drop control method that is smaller than the third taper angle on the outer side (sixth invention).

7. In the fifth invention, the shape of the crown applied to one end of the rolling roll is represented by a higher-order function of a cubic expression or higher or a triangular function and a linear expression. 7 invention).

8. In the fifth, sixth or seventh invention, the work roll shift amount (S) is a shift change amount ΔS ₁ that minimizes the value of J _{1 represented by} the following equations (1) and (2).
The amount of shift change Δ that minimizes the value of J ₂ expressed by equation (3)
An edge drop control method that is the sum of S ₂ (eighth invention). _{eh n (X) / h n} = (P (X, T) × G (X, S 1 + ΔS 1) + EH (X)) / H --- (1) J 1 = | Ec (X) - ( eh _n (X)) | ² --- (2) where Ec (X): target edge drop amount, eh _n (X)
: Predicted edge drop amount, X: board width direction coordinate,
P: Transfer rate, EH: Mother plate edge drop amount, G: First stand taper amount, H: Mother plate width center plate thickness,
h _n : product width center thickness, S ₁ : current shift amount,
[Delta] S _1: shift variation, eh _n: Product edge drop amount _{J 2 = | Ec (X)} - (Ea (X) + ΔE (ΔS 2)) | 2 --- (3) where, Delta] E: Any Edge drop change amount in the width direction, ΔS ₂ : shift change amount

In each of the above inventions, instead of measuring the profile of the plate material on the inlet side of the first stand, the profile of the plate material measured on the outlet side of the hot finish rolling mill can be used.

First, the first to fourth inventions will be described.
FIG. 1 shows a configuration of a cold rolling facility suitable for carrying out the first to fourth inventions, particularly by taking out only the first stand. In the figure, reference numeral 1 is a plate material, and 2 and 3 are Work rolls that sandwich the plate material 1 between the upper and lower sides. These work rolls 2 and 3 are shown in FIG. 2 (a) or FIG. 2 (b) ((a) is a roll having a three-step taper, (b) is a COS curve and 1) As shown in the following formula), a crown that is tapered in three steps toward the outermost end of the roll is provided, and when the plate material 1 is rolled, the edge portion is rolled down at this portion. Further, 4 is an intermediate roll, 5 is a backup roll, and 6 is an edge profile meter installed on the entrance side of the first stand. The edge profile meter 6 measures the profile of the mother board.

Reference numeral 7 is a work roll shift position calculating device, and 8 is a work roll position detector. The shift position calculating device 7 calculates the roll shift position based on the signal from the position detector 8. To do. Reference numeral 9 is a position control device that operates a shift device 12 that is hydraulic or electric based on the result of the arithmetic device 7.

FIG. 3 shows an example of equipment in the case where the profile of the plate material 1 is measured on the outlet side of the hot finish rolling mill 10.

[0022]

In the rolling using the work roll having the tapered crown, the crown of the roll is transferred to the plate, so that the edge drop can be controlled by transferring the crown to the plate.

FIG. 4 shows the transfer rate (the rate at which the roll shape is transferred to the plate) obtained by an experiment. The conditions of this experiment are that the thickness of the base plate is finished from 2.4 mm to 1.5 mm in one pass, and the taper shape is expressed by a linear equation. The taper size is 4 levels (tan θ = 1/300, 1/400, 1/1 / 600, 1 /
800).

As is clear from FIG. 4, the greater the degree of taper applied to the work roll, the greater the transfer rate, and the smaller the transfer rate toward the center in the plate width direction, the smaller the transfer rate. .

Further, from FIG. 4 above, as a region where the transfer rate changes, a range where the transfer rate from the edge of the plate material to 20 mm sharply decreases, and a range where the transfer rate of the edge 20 to 60 mm is almost constant It can be seen that there are three areas in which the transfer rate decreases from the edge 60 mm to the center in the plate width direction.

Therefore, a high-precision product can be obtained by controlling the edge drop using rolls having different crowns in these three regions.

That is, in the case of controlling the mother plate profile in the central region in the width direction of the plate material, it is advantageous to carry out rolling at a portion having a crown having a large taper angle (first tapered region).

Further, in the range of 20 to 60 mm from the edge of the plate material, it is larger than the transfer rate of the first tapered area,
Moreover, since the profile formed in the 1st pass is sufficiently inherited to the downstream, it is appropriate to roll this region (the 2nd tapering region) with a crown having a small taper angle of the 1st tapering region. Is. Further, although the transfer rate is large in the area of the edge to 20 mm, edge drop occurs in the downstream stand due to the metal flow particularly in the plate width direction at the edge portion. In order to prevent such edge drop, it is preferable to roll with a roll crown having a taper angle larger than that of the second tapered region.

Incidentally, the COS as shown in FIG.
A roll crown made of a curve is the same as a Sin curve, and since these curves can be series-expanded by a higher-order function of a cubic expression or higher, even if approximated by a function of a cubic expression or higher. I don't care.

FIG. 5 shows an example of a profile of a base material (hot rolled sheet) having a large crown. Usually from the edge
The crown ratio before and after hot rolling hardly changes inside about 50 mm, so that the starting point of the taper of the work roll should be set to a position of the plate thickness ratio within the target edge drop. In the case of the plate material having the profile shown in FIG. 5, the plate thickness ratio deviation is 1
It is necessary to set the shift position to approx.

By the way, since the profile of the mother plate varies not only in each coil but also in each coil, it is necessary to set and correct the position of the work roll by applying the present invention. The method of setting and correcting the work roll shift position will be described below. (a) Profile profile of No. 1 stand or hot rolling finishing mill
Work roll shift of the 1st stand based on the measurement result of
Method of setting the transfer position The transfer rate (P) shown in FIG. 3 is a function of the coordinate X in the plate direction and the taper angle (T). Further, as the taper angle (T) increases, the transfer rate increases almost in proportion to the taper angle. Therefore, the edge drop ratio eh on the delivery side of the first stand (the profile is divided by the sheet thickness h ₁ on the delivery side of the first stand) eh can be expressed by the following equation from the profile measurement of P and the mother plate. Here, the transfer rate P can be obtained by an empirical formula or calculation.

Therefore, after all, the edge drop (eh _n ) of the product in the cold rolling mill consisting of n stands is expressed by the following equation:
(1) eh _n (X) / h _n = (P (X, T) × G (X, S ₁ + ΔS ₁ ) + EH (X)) / H --- (1) where X: plate width Directional coordinates, P: Transfer rate, EH:
Mother plate edge drop amount, G: First stand taper amount, H: Mother plate width center plate thickness, h _n : Product plate width center plate thickness, S ₁ : Current shift amount, ΔS ₁ : Shift change amount,
eh _n : will be represented by the product edge drop amount,
For the product edge drop, eh _n (X) can be obtained excluding the edge portion.

Therefore, in this case, the target edge drop (Ec (X)) and the predicted edge drop amount (eh _n (X))
It is sufficient to determine ΔS ₁ so that the difference with
That is, ΔS ₁ exists to minimize J ₁ in the following equation (2). _{J 1 = | Ec (X)} - (eh n (X)) | 2 --- (2)

Next, the fifth to eighth inventions will be described. FIG. 6 shows the configuration of a cold rolling facility suitable for use in carrying out the fifth to eighth inventions, particularly by taking out only the first stand. Since the skeleton of the configuration is common to that in FIG. 1 above, the same reference numerals are given and shown, and numeral 11 in the drawing is an edge profilometer installed on the exit side of the rolling mill train. In the fifth to eighth inventions,
The edge profile meter 6 installed on the entrance side of the first stand measures the profile of the mother plate, and the shift position of the work roll is set based on the measurement result, while the edge profile meter 11 installed on the exit side of the rolling mill train 11 However, the edge profile after rolling is measured, and the shift position of the work roll is corrected by the computer 7 based on the measurement result. Thus, more highly accurate edge drop control is realized.

A method of setting the work roll shift position according to the fifth to eighth inventions will be described below. (a) Profile profile of No. 1 stand or hot rolling finishing mill
Work roll shift of the 1st stand based on the measurement result of
For this method how to configure the door position is the same as has been described for the case of the first to fourth invention prior.

(B) The cold rolling mill train is equipped with a plug on the exit side of the final stand.
Based on the measurement results of the lofil meter, the 1st stand work
How to set the crawl shift position From the measurement results of the plate profile installed on the rolling mill side,
A method of correcting the shift position will be described. According to the rolling experiment, when the work roll shift amount is moved by ΔS _2, the edge profile meter on the outlet side of the rolling mill measures the profile change of the edge part, and the influence of the shift amount on the profile change on the outlet side of the rolling mill. In advance. The effect of the shift amount on the profile change on the delivery side of the rolling mill can be easily obtained from the experiment of the actual mill as shown in FIG. That is, when the shift amount ΔS ₂ is changed, the edge drop change amount (ΔE) at any position in the width direction can be obtained from FIG. 7. The edge drop change amount (ΔE) is the width direction coordinate X and the shift change amount (ΔS).
₂ ) function.

Next, assuming that the measurement result of the edge profilometer installed on the exit side of the final stand is Ea and the target edge drop amount is Ec, these deviations are (Ec (X)-
Ea (X)). In order to minimize this deviation, for example, the optimum shift change amount (Δ) that minimizes J ₂ is calculated from the difference between the target edge drop amount and the following equation (3).
S ₂ ) can be decided. J ₂ = | Ec (X)-(Ea (X) + ΔE (ΔS ₂ )) | ² --- (3)

(C) The first stand or the hot rolling finishing mill
Based on the measurement results of the lofil meter, the 1st stand work
While setting the crawl shift position,
Based on the measurement result of the profile meter on the stand output side,
Method of correcting the work roll shift position of one stand This method is a case where both the above-mentioned (a) and (b) are used in combination, and further highly accurate edge drop control becomes possible. As shown in FIG. 8, this method shows a calculation flow that minimizes the deviation between the measured profile in the width direction and the target profile, and uses the equations (1) and (2) for the first stand. The work roll shift amount is changed.
According to this control method, the plate thickness deviation after the first pass can be reduced by the method (a) above, and the work roll shift position can be corrected by the method (b) above. It is possible to further control the plate thickness deviation, which could not be controlled only by the method a), and it is possible to realize highly accurate edge drop control.

Specific preferred conditions for the three-step taper imparted to the roll end or the crown represented by (trigonal function + first-order equation) or third-order equation will be described below. (1) 1st stage taper angle and length Only the work rolls of the 1st stand of the tandem rolling mill train consisting of 4 stands are provided with primary taper at various angles, and this rolling mill train is used. The product profile when a coil with a base plate thickness of 2.4 mm is rolled to a finish thickness of 0.5 mm,
It shows in FIG. According to the figure, the larger the taper angle, the more the edge drop can be controlled to the inside.
When a 300 taper roll is used, a gouged portion is generated in the vicinity of the taper starting position of the work roll, and the widthwise thickness accuracy of the final product is reduced. In this respect, the 1/350 has a relatively small gouging part. In the case of the 1/400 taper roll, it becomes almost flat, and at 1/450, the control amount of the taper in the first stage slightly decreases, but this is not a problem. Therefore, the 1st taper is 1/350 to 1/450
The degree is preferable, and the length is as shown in FIG.
It is good to set it to about 60 mm.

(2) Taper angle and length of the second step The taper angle of the second step is 1/600 as shown in FIG.
In the case of rolling with the taper of No. 2, the change of the plate thickness is the smallest in the second 40 mm area. The change is also small at 1/450 and 1/700, so the taper angle of the second stage is 1/4.
It is preferable that the length is about 50 to 1/700 and the length is about 40 mm.

(3) Third stage taper angle and length Similarly, the third stage taper for rolling the plate edge portion shows the largest change in sheet thickness when rolling at 1/400 except for the outermost edge. It is small and good, but 1/350 and 1/450 can be expected to have the same effect. Therefore, the taper angle of the 3rd step is
About 1/350 to 1/450, and its length is preferably about 50 mm.

(4) Suitable conditions for taper length The taper angle and its length are determined from the results shown in FIG. 9, but as shown in FIG. 4, the transfer rate increases as the taper angle increases, so edge drop control is performed. In order to carry out the above, it is preferable to apply in a range where the transfer rate is large. Assuming that the range in which the transfer rate is greater than 0 is the taper transfer limit, the transfer limit is determined by the taper size and the mother plate thickness, as shown in FIG. Note that FIG. 10 was obtained in the same manner as the conditions of FIG. 4, and is the result of rolling from each plate thickness at a rolling reduction of 37.5%. According to FIG. 10, in the cold rolling, the mother plate rolling is about 4 mm at most, so
If the taper angle of the step is 1/400, taper shape is 15
It is sufficient to add up to about 0 mm.

When the crown to be applied to the end of the work roll has a shape of a cubic expression or a trigonometric function and a linear expression, a shape close to a taper of these three steps is given and its length is set. It is preferably about 150 mm. That is, the lower limit and the upper limit of the optimum range of the above-mentioned three-step taper shape are as shown in FIG. 11. Therefore, it is expressed by a cubic expression or a trigonometric function and a linear expression so as to be within this range. It may be given a shape.

[0044]

【Example】

Example 1 A 4-stand rolling mill train (a cold rolling mill train, which is a cold rolling mill train, which is composed of 6-high rolling mills as shown in FIG. 12 in which an edge profile meter capable of measuring the profile of the base material is arranged on the inlet side.
The diameter of the work roll is 400 mm, the roll length of the work roll is 1500 mm, the rolling speed of the final stand is 500 m / min, and the reduction ratio of each stand is evenly distributed. Plate thickness) A 2.4 mm coil was finished up to 0.5 mm, and the change in edge drop in the longitudinal direction of the obtained plate material was investigated.

Conformance example 1 ---- No. 1 in FIG. 13 is attached to the first stand.
Apply a roll that has the shape of 1 (three-step taper represented by a linear equation), calculate the shift amount by the method of (a) above based on the measurement result of the edge profilometer, and calculate it. The work rolls are shifted based on the value and rolled (flat rolls for the second to fourth stands). Conformance example 2 --- Apply a roll (having a COS curve and a taper consisting of a linear equation) of No. 2 in Fig. 13 to the first stand, and based on the measurement result of the edge profilometer, The amount of shift is calculated by the method described in (a) above, and the work roll is shifted based on the calculated value to perform rolling (the second to fourth stands are flat rolls). Comparative Example 1 --- A roll having a No. 3 shape in FIG. 13 (having a two-step taper) was applied, the starting point of the taper was positioned 70 mm from the edge, and the roll position was kept constant (2 The fourth stand is a flat roll). Comparative Example 2 --- A roll having the shape of No. 3 in FIG. 13 is applied, and the work roll is shifted and rolled based on the measurement result of the edge profilometer (the second to fourth stands are flat rolls).

FIG. 14 shows the survey results. As is clear from FIG. 14, in the conforming examples 1 and 2, the change in the edge drop was small even if the crown of the mother board was changed, and a good product was obtained, whereas in the comparative example 1, the edge drop of 25 mm in the edge was obtained. In the comparative example 2, when the crown at the hot side becomes smaller, the edge-up becomes larger. In Comparative Example 2, the edge drop at the edge of 25 mm can be controlled, but the edge drop at the position of 50 mm is 10.
It was confirmed to be as large as μm.

Example 2 An edge profilometer for measuring the profile of a mother plate is arranged on the exit side of a hot-finish rolling mill train, and a 4-stand rolling mill train consisting of 6-high rolling mills (work roll The diameter is 400 mm, the roll body length is 1500 mm, the rolling speed of the final stand is 500 m / min, and the rolling ratio of each stand is evenly distributed. The side (mother plate pressure) coil of 2.4 mm was finished to 0.5 mm, and the edge drop condition of the obtained plate material was investigated.

Conformance Example 1 ---- No. 1 in FIG. 13 is attached to the first stand.
Apply the roll having the shape of 1 and calculate the shift amount by the method of (a) above based on the measurement result of the edge profilometer, and shift the work roll based on the calculated value to perform rolling (second to second). The fourth stand is a flat roll). Conformance example 2 ---- Applying a roll with the shape of No. 2 in Fig. 10 and based on the measurement result of the edge profilometer.
The shift amount is calculated by the method of (a), and the roll roll is shifted based on the calculated value to perform rolling (the second to fourth stands are flat rolls). Comparative Example 1 --- A roll having the shape of No. 3 in FIG. 13 was applied and rolling was performed with the starting point of the taper positioned at 70 mm from the edge to keep the roll position constant (the second to fourth stands were flat rolls). Comparative Example 2 --- A roll having the shape of No. 3 in FIG. 13 is applied, and the work roll is shifted and rolled based on the measurement result of the edge profilometer (the second to fourth stands are flat rolls).

The results are shown in FIG. In the conformity examples 1 and 2, the change of the edge drop was small even if the crown of the mother board was changed, and a good product was obtained, whereas in the comparative example 1, the edge drop of the edge 25 mm has a small hot crown. Then, the edge-up becomes large, and Comparative Example 2
Then, although you can control the edge drop of 25 mm edge,
The edge drop at the position of 50 mm was as large as about 10 μm.

Example 3 An edge profile meter capable of measuring the profile of the base material was installed on the inlet side of the first stand of the cold rolling mill and the outlet side of the row of the cold rolling mill. Six stages as shown in FIG. 4 stand rolling mill row (work roll diameter: 400
mm, work roll barrel: 1500 mm, rolling speed of final stand: 500 m / min, reduction ratio of each stand is equally distributed), plate width: 1000 mm, inlet side (mother plate thickness): 2.
The 4 mm coil was finished to 0.5 mm, and the edge drop condition of the obtained plate material was investigated.

Adaptation example 1 ---- No. 1 in FIG. 13 is attached to the first stand.
The amount of shift is calculated by the method of (a) to (c) above based on the measurement results of the edge profilometers that are applied to the 1st roll and the 1st stand entrance side and the rolling mill exit side. Then, the work roll is shifted based on the calculated value and rolled (the second to fourth stands are flat rolls). Conformance example 2 --- Based on the measurement results of the edge profilometers, which are arranged on the inlet side of the first stand and the outlet side of the rolling mill, by applying the roll having the shape of No. 2 in Fig. 13, (a).
The amount of shift is calculated by the method of (c), and the roll roll is shifted based on the calculated value to perform rolling (the second to fourth stands are flat rolls). Comparative Example 1 --- A roll having the shape of No. 3 in FIG. 13 is applied, and the roll starting point is located at 50 mm from the edge, and the roll position is kept constant (the second to fourth stands are flat rolls). Comparative Example 2 ---- Work rolls were shifted based on the measurement results of the edge profilometers arranged on the first stand entrance side and the rolling mill row exit side by applying the rolls having the No. 3 shape in FIG. Rolling (the second to fourth stands are flat rolls).

FIG. 18 shows the investigation result. As is clear from the figure, in the conforming examples 1 and 2, even if the crown of the mother plate changed, the change in edge drop was small, and good products were obtained. On the other hand, in Comparative Example 1, although the edge drop at the edge of 25 mm could be controlled, the edge drop at the position of 50 mm was as large as about 5 to 10 μm, and it was difficult to control the edge drop in the plate width direction. In Comparative Example 2, Comparative Example 1
On the contrary, although it was possible to control the edge drop at the edge of 50 mm, it was difficult to control the edge drop at the position of the edge of 25 mm. Thus, even if a high-precision control method is applied, a good profile cannot be obtained unless the taper shape given to the work roll is inappropriate as in the conventional method. The profile of the mother board is the first
It has been confirmed that the same effect can be obtained even when the measurement is performed on the outlet side of the hot finish rolling mill row instead of on the inlet side of the stand.

[0053]

As described above, according to the present invention, the edge drop can be reduced even when the hot crown is large, and the profile in the plate width direction can be made uniform. As a result, yield and production efficiency can be improved.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a cold rolling facility suitable for carrying out the first to fourth inventions.

FIG. 2 is a diagram showing a roll profile of a work roll.

FIG. 3 is a diagram showing a configuration when a profile of a base material is measured on the outlet side of a hot rolling facility.

FIG. 4 is a diagram showing a transfer state of a roll profile.

FIG. 5 is a diagram showing a state of an edge profile of a plate material.

FIG. 6 is a diagram showing a configuration of a cold rolling facility suitable for carrying out the fifth to eighth inventions.

FIG. 7: Roll shift change amount ΔS ₂ and edge up amount Δ
It is the figure which showed the relationship with E.

FIG. 8 is a flowchart showing a procedure for calculating a roll shift amount according to fifth to eighth inventions.

FIG. 9 is a diagram showing a comparison of differences in plate thickness profile when various sizes of taper angles are changed.

FIG. 10 is a diagram showing a transfer limit at each plate thickness.

FIG. 11 is a diagram showing a preferable range of a shape represented by a cubic expression or a triangular function and a linear expression.

FIG. 12 is a schematic view of a cold tandem rolling mill including an edge profilometer on the entrance side of the first stand.

FIG. 13 is a diagram showing a crown shape of a roll end portion.

FIG. 14 is a diagram showing a result of investigating the state of edge drop in the longitudinal direction of the plate material.

FIG. 15 is a diagram showing a configuration of equipment suitable for carrying out the present invention.

FIG. 16 is a diagram showing a result of investigating the state of edge drop in the longitudinal direction of the plate material.

FIG. 17 is a schematic view of a cold tandem rolling mill provided with an edge profilometer on the inlet side of the first stand and the outlet side of the rolling mill.

FIG. 18 is a diagram showing a result of investigating the state of edge drop in the longitudinal direction of the plate material.

[Explanation of symbols]

 1 Plate Material 2 Work Roll 3 Low Roll 4 Intermediate Roll 5 Backup Roll 6 Edge Profil Meter (Inlet Side) 7 Work Roll Shift Position Calculator 8 Work Roll Position Detector 9 Work Roll Position Controller 10 Hot Finishing Rolling Mill 11 Edge profile meter (outgoing side) 12 Shift device C coiler

Front page continued (72) Inventor Isao Akagi 1-chome, Mizushima Kawasaki-dori, Kurashiki City, Okayama Prefecture (no address) Inside Kawashima Steel Co., Ltd. (72) Inventor Naoki Hayase 1-chome, Mizushima Kawasaki-dori, Kurashiki City, Okayama Prefecture None) Mizushima Steel Works, Ltd., Kawasaki Steel Co., Ltd. (72) Takahiro Ueda, Takashima Ueda, Kurashiki City, Okayama Pref. 1, Kawashima-dori, Mizushima Kawashima Steel Co., Ltd., Mizushima Steel Works, Ltd. (72) Toshio Nakanishi, Kurashiki City, Okayama Prefecture Mizushima Kawasaki Dori 1-chome (without street number) Kawasaki Steel Works Mizushima Steel Works

Claims (8)

[Claims] 1. A rolling roll is provided with a crown which is tapered in at least three steps toward one end of a rolling roll, and the tapered ends are alternately assembled so as to be point-symmetrical, and a pair of upper and lower rolls are installed. When cold rolling a plate using a tandem rolling mill row equipped with the work rolls, the profile of the plate is measured at the entry side of the first stand, and the work roll of the rolling mill is rolled based on the measurement result. A method for controlling edge drop of a plate material in cold rolling, which comprises shifting in a direction. 2. The shape of the crown applied to one end of the rolling roll according to claim 1, is represented by a taper represented by a three-stage linear equation, and the second taper angle has an inner side. Is smaller than the first and outer third taper angles of the edge drop control method. 3. The edge drop according to claim 1, wherein the shape of the crown applied to one end of the rolling roll is represented by a higher-order function of a cubic expression or higher or a triangular function and a linear expression. Control method. 4. The edge according to claim 1, wherein the work roll shift change amount (ΔS ₁ ) minimizes the value of J _{1 represented by} the following equations (1) and (2). Drop control method. _{eh n (X) / h n} = (P (X, T) × G (X, S 1 + ΔS 1) + EH (X)) / H --- (1) J 1 = | Ec (X) - ( eh _n (X)) | ² --- (2) where Ec (X): target edge drop amount, eh _n (X): predicted edge drop amount, X: board width direction coordinate, P: transfer rate, EH: Mother plate edge drop amount, G: First stand taper amount, H: Mother plate width center plate thickness, h _n : Product plate width center plate thickness, S ₁ : Current shift amount, ΔS ₁ : Shift change Amount, eh _n : Product edge drop amount 5. A rolling roll is provided with a crown that is tapered in at least three steps toward one end of the rolling roll, and the tapered ends are alternately assembled so as to be point-symmetrical, so that a pair of upper and lower crowns are provided. When cold rolling a plate using a tandem rolling mill row equipped with the work rolls, the profile of the plate is measured at the entry side of the first stand, and the work roll of the rolling mill is rolled based on the measurement result. A method for edge-drop control of a plate material in cold rolling, comprising: shifting in a direction, measuring the profile of the plate material even on the exit side of the final stand, and correcting the work roll shift amount based on the measurement result. 6. The shape of a crown applied to one end of a rolling roll according to claim 5, is represented by a taper represented by a three-stage linear equation, and a second taper angle has an inner side. Is smaller than the first and outer third taper angles of the edge drop control method. 7. The edge drop according to claim 5, wherein the shape of the crown applied to one end of the rolling roll is represented by a higher-order function of a cubic expression or higher or a triangular function and a linear expression. Control method. 8. The work roll shift amount (S) according to claim 5, 6 or 7, wherein J is represented by the following equations (1) and (2).
A shift amount of change [Delta] S ₁ to a value of ₁ and the minimum, edge drop control method is the sum of the shift change amount [Delta] S ₂ to minimize the value of J ₂ represented by equation (3). _{eh n (X) / h n} = (P (X, T) × G (X, S 1 + ΔS 1) + EH (X)) / H --- (1) J 1 = | Ec (X) - ( eh _n (X)) | ² --- (2) where Ec (X): target edge drop amount, eh _n (X): predicted edge drop amount, X: board width direction coordinate, P: transfer rate, EH: Mother plate edge drop amount, G: First stand taper amount, H: Mother plate width center plate thickness, h _n : Product plate width center plate thickness, S ₁ : Current shift amount, ΔS ₁ : Shift change Amount, eh _n : product edge drop amount J ₂ = | Ec (X) − (Ea (X) + ΔE (ΔS ₂ )) | ² --- (3) where ΔE: at any position in the width direction Edge drop change amount, ΔS ₂ : Shift change amount