JPS62296904A - Method for controlling sheet width - Google Patents

Abstract

PURPOSE:To control the width of a metallic sheet so that said width coincides with a target value and to improve the yield of said sheet by measuring or calculating the amt. of crown of the metallic sheet after rolling and controlling the width thereof in accordance with the measured or calculated amt. of crown and the change rate of the sheet width with respect to the preliminarily determined change of the amt. of crown. CONSTITUTION:A profile meter 5 is provided on the outlet side of a finishing mill 4. The meter 5 measures the difference in the thickness between the transverse end of the steel sheet after the finish rolling and the position of the prescribed size from said end and the transverse central part and applies the measured value to an arithmetic control unit 6. The arithmetic control unit 6, when inputted with the signal from the profile meter 5, reads out the thickness and width of the steel sheet intended to the rolled preset in a host computer and reads a coefft. K in accordance with the readout thickness and width. Said unit calculates the width change DELTAW in accordance with the coefft. K, the readout thickness and width, the measured value of the thickness difference which is the input signal, and the thickness difference which is the input signal, and the prescribed equation. The arithmetic control unit 6 controls the roll gap of vertical rolls 2 in order to eliminate the calculated DELTAW.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method for controlling the rolling of a metal sheet to a target width.

[Prior Art] As a method of rolling a metal plate, many methods have been proposed in the past for controlling the width of the metal plate to a target value (for example, JP-A-60-37206).

These controls are performed by various combinations of measurement items and control items, which will be described later.The control items include the opening of the horizontal rolling rolls, the opening of the rolling rolls, the tension of the metal plate between the stands, and the rolling Cargo m.

There is bending in the axial direction of the rolling roll, and the force measurement items include the width of the metal plate, rolling temperature, and rolling reaction force.

These include the opening of the rolling rolls, the tension of the metal plate between the stands, etc.

[Problem that the invention seeks to solve]

In this way, there are a large number of measurement items and control items. This is due to the fact that it is affected by the thickness, material, temperature, etc. of the metal plate.

However, with conventional control methods, it is difficult to control the tension of a metal plate between stands accurately in accordance with the position of the metal plate, and it is difficult to accurately adjust the plate width. Ta. For this reason, even if the plate width changes, the minimum width must be greater than or equal to the product width, and the target width must be adjusted so that there is a surplus.
Therefore, when a product is obtained by slitting both ends of a rolled metal plate in the width direction, a large number of cut-off portions are produced, resulting in poor yield.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a method for controlling the rolling width of a metal sheet, which allows the sheet width to be adjusted to a target value with high accuracy, thereby improving the yield. .

[Means for solving problems]

The present invention utilizes the fact that there is a relationship between the crown amount and the plate width as will be described in detail later, and controls the plate width based on the crown amount.

The sheet width control method according to the present invention determines the amount of crown of a rolled metal sheet by measurement or calculation, and sets the width of the metal sheet as a target based on the determined amount of crown and the amount of change in sheet width with respect to the change in the amount of crown determined in advance. It is characterized by controlling rolling to a certain value.

[Function] In the present invention, since the rolling control of the slope width is performed based on the amount of crown of the metal plate, which has a strong relationship with the width of the metal plate after rolling, the plate width can be controlled with high accuracy.

In addition, yield can be improved by highly accurate sheet width control.

[Principle of the invention]

First, the principle of the present invention will be explained. FIG. 1 is an explanatory diagram of width dimension changes when the amount of crown differs. 0 Metal plate with standard crown shape when rolled under normal operating conditions.
For example, the thickness at the center of the width of a steel plate (solid line) is a rolled steel plate (where W is the plate width, the thickness at the end face in the width direction is thinner than that of a standard crown-shaped steel plate, and the thickness t at the center of the width is the same). (line break), the width is increased by ΔW. Figure 2 shows the 25 fl crown amount (difference in thickness between the position 25 mm from one width direction end and the width center) (horizontal axis) of a hot rolled steel plate with a width of 1236 m and a thickness of 3 Jma after finish rolling. )and,
It is a graph showing the relationship between the width expansion amount (vertical axis) and the plate width dimension of the reference crown shape.

As can be understood from this figure, there is a linear relationship between the crown amount and the width spread amount. The coefficient K (>0) of the slope of the straight line representing this relationship is expressed by the following equation (1), and is 0.069 fi/μ in this example.

k-Δε-/Δεt...(1) However, Δε-change in double width spread (>0) Δεt: 2
5m Amount of change in crown amount (>0) This k varies depending on the target width and thickness of the hot rolled steel sheet. Figure 3 shows width: 9
Figure 4 shows the relationship for a hot-rolled steel plate of 14ts, thickness: 2.3mm, width: 1100m, thickness: 4mm. The relationship is shown in the case of a hot rolled steel plate with Qm, and the value of k is 0.059 *■/μ, respectively.

It becomes 0.037 dragon/μ.

Considering the influence of the value of thickness 1 width itself, the following equation (2) is determined in order to normalize the coefficient k (coefficient K after normalization).

W: However, CR: 25■1 crown amount C after rolling of the material to be controlled
o: Amount of 251111 crowns after rolling under normal operation 1 condition If the above equation (2) is rearranged with respect to ΔW, the following equation (3) is obtained.

ΔW=to-W・1/l・(CRCO) −
f3) Figure 5 is a plot of the coefficient K for multiple steel plates with different target thicknesses and widths, with the horizontal axis representing the sheet width (■a) and the vertical axis representing the normalized coefficient K. It is. As can be understood from this figure, if we look at the relationship between the plate width and the coefficient for steel plates with a plate thickness of 4.0 to 4.3 mm (△) in the figure, if the plate width is wide, the value of K is large and the plate width is narrow, the value of K will be small. Also, if we look at steel plates with different thicknesses around 1100 mm in width, we find that steel Fi (
), the value of K is large for thin steel plates (marked with ○) of 3.211, and on the contrary, the value of K is small for thicker plates with mFi of 8.9 fins (marked), and It is smaller than the K value of a steel plate with an intermediate thickness of 4.0 to 4.3 fi.

The coefficients after normalization have a smaller amount of change than the coefficients before normalization, and also have a certain tendency.

Therefore, using a profile maker or the like, measure the thickness at a position 25 feet from the end in the width direction and the thickness at the center of the width, calculate cR from the difference, and calculate K from the relationship shown in FIG. 5 as an example. This is stored for each plate thickness and plate width, and the value is read out from this, and the CH2F is the W of the steel plate after rolling, (and c
ΔW is calculated by substituting it into equation (3) together with o, and rolling control is performed so as to eliminate the ΔW. Thereby, it becomes possible to make the width of the steel plate after rolling match the target value over the entire length.

In addition, when rolling using a variable crown roll, a roll bender, or a work roll shift, the above cR is as follows:
The correlation between the amount of bending (Vc amount) of each roll and the amount of crown of the steel plate may be determined in advance, for example, in the form of equation (4) below, and the calculation may be performed using this.

CR= A °Vc + B - (41 However, A
, B: constant In addition, when carrying out width control rolling by installing a vertical roll on the entry side or in the middle of the finishing rolling mill and adjusting the roll opening degree to perform width reduction, instead of the above formula (3), Then, control is performed using the following equation (5), which takes into account the width return due to subsequent horizontal rolling of the steel plate, which has become a narrow tongue pawn shape due to the vertical rolls.

D: @Return coefficient, as shown in Fig. 6, due to width reduction, the steel plate before rolling ((a) in the same figure) becomes a tongue bone shape with a narrow width of 4w1 as shown in Fig. 6. This is because the width returns by ΔW2 as shown in FIG.

〔Example〕

The present invention will be specifically explained below based on the drawings.

FIG. 7 is a schematic diagram showing the implementation state when the present invention is applied to a hot rolling process equipped with vertical rolls, and 1 in the figure indicates a strip-shaped steel plate. After the steel plate 1 is roughly rolled in a rough rolling mill (not shown), it is rolled down in width by a vertical roll 2, and then rolled in a horizontal rolling mill 3 and 6 stands (Fl to Fs) provided at the subsequent stage.
It is horizontally rolled down to a desired thickness 1 by a finishing mill 4 consisting of
It is designed to be finish rolled to width.

Each stand of finishing rolling mill 4 is a roll bender.

It is equipped with a work roll shift (WR5) and a variable crown roll <VC), and the tension of the steel plate between each stand is automatically controlled.

A profilometer 5 is provided on the exit side of the finish rolling mill 4, and the profilometer 5 measures the difference in thickness between the width end of the steel plate after finish rolling, a position 2511 from the end, and the width center. , the measured value is given to the arithmetic and control unit 6.

The above equation (5) is set in the arithmetic and control device 6, and when the arithmetic and control device 6 receives a signal from the profile meter 5, the arithmetic and control device 6 calculates the thickness and width of the steel plate to be rolled, which are preset in a host computer (not shown). Read out and calculate K based on the plate thickness and plate width.
is read, and the plate width change ΔW is calculated based on this K, the read plate thickness and plate width, the constant thickness difference value as the input signal, and equation (5).

Then, the arithmetic and control device 6 controlled the roll opening degree of the vertical roll 2 in order to eliminate the calculated ΔW. In addition, the actual width of the steel plate after finish rolling and the looper tension.

The roll opening degree of the vertical rolls 2 may be controlled by taking into consideration the rolling schedule, the width of the hVi plate after rough rolling, temperature information, etc.

Figure 8 shows that when the method of the present invention is applied from the middle of rolling,
This is a graph showing the average value of the rolling surplus width of the truncated portion over the entire length when a finish-rolled strip-shaped steel plate is slit to obtain a product (hot coil) with a predetermined width, before and after it is applicable to the present invention. The average rolling margin width (1) is plotted on the axis. In the figure, the white circles indicate the average value of the rolling margin when using the method of the present invention, and the black circles indicate the average value when using the conventional method.

As can be understood from this figure, in the &Wi board immediately after the application of the present invention begins, there is an uncontrolled part due to the distance from the vertical roll to the profile meter, so the yield is somewhat better than before, and the subsequent With steel plates, this problem is resolved, so the amount of cut-off parts can be significantly reduced.

Figure 9 shows the rolling margin standard deviation (vertical axis) of the truncated portion over the entire length of a product taken from a cold rolled steel sheet when the present invention is applied to the cold rolling process from the middle of rolling as before. This is a graph similarly shown, in which white circles indicate the rolling margin standard deviation in the case of the method of the present invention, and black circles indicate that in the case of the conventional method. As can be understood from this figure, even when the present invention is applied to a cold rolling process, the cut-off portion can be reduced compared to the conventional method as before.

Therefore, in the case of the present invention, the width of the plate after finish rolling could be adjusted to the target width over substantially the entire length.

Note that in the above embodiment, since rolling is performed in the width direction using vertical rolls, equation (5) is used; however, the present invention is not limited to this, and when rolling is performed without using vertical rolls, equation (3) above is used. It is also possible to carry out the rolling control by controlling the rolling.

Furthermore, in the above explanation, the crown amount is determined at the end face and at a position closer to the center of the end face, but the present invention is not limited to this, and the crown amount is determined in a linear manner as shown in Fig. 2.3.4. Of course, the position where the relationship is obtained may be used as the crown amount determination position.

Further, in the above embodiment, the 25fi crown amount is actually measured using a profilometer, but the present invention is not limited to this, but calculates cR using the above formula (4) and calculates the difference between this cR and the known co. Find the value by 25■■
Of course, rolling control may be performed as the amount of crown.

Further, in the above description, a steel plate is used as an object to be rolled, but the present invention is not limited to this, and it goes without saying that plate-shaped metal materials in general can be rolled.

〔effect〕

As described in detail above, the present invention measures or calculates the crown amount of a gold plate after rolling, and controls the sheet width based on the crown amount and a predetermined amount of change in sheet width with respect to the change in crown amount. Therefore, the width of the metal plate can be made to match the target value,
For this reason, excellent effects can be achieved, such as reducing the amount of discarded portions when producing products and improving yield.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the control principle of the present invention, Fig. 2.3.4 is a graph showing the relationship between the amount of 25-tsuru crown and the amount of finished width spread, and Fig. 5 is a graph showing the coefficients used when implementing the present invention. A diagram showing the relationship between sheet width and sheet thickness, FIG. 6 is an explanatory diagram of the width return of a steel sheet after width control rolling, FIG. 7 is a schematic diagram showing the implementation state of the present invention, and FIG. 8 is a diagram showing the present invention FIG. 9 is an explanatory diagram of the effect when the present invention is applied to a hot rolling process, and FIG. 9 is an explanatory diagram of the effect when the present invention is applied to a cold rolling process. 1... Steel plate 2... Vertical roll 4... Finishing rolling mill 5... Profile meter 6... Arithmetic control unit Applicant Sumitomo Kinku Industries Co., Ltd. Agent Patent attorney Noboru Kono No. 1 Fig. 25mm 7 pieces 1 ohm → Fig. 2 25mm ri'y 1L (・le") Fig. 3 25mm 7 tsutsuzu % (F) Plate turtle (mm) Fig. 5 (turtle cut) W) Fig. 6 1 d] Figure 8 (chi 1) Figure 9

Claims (1)

[Claims] 1. The crown amount of the rolled metal sheet is determined by measurement or calculation, and the width of the metal sheet is controlled to a target value based on the determined crown amount and the amount of change in sheet width with respect to the change in the amount of crown determined in advance. A method for controlling plate width.