JPS61154709A - Device for controlling thickness profile of sheet stock - Google Patents

Abstract

PURPOSE:To control a sheet profile into an aimed one through the whole period of rolling by adjusting properly the shifting amount of a work roll in accordance with the variation of the sheet profile of a steel sheet to be rolled when the variation is produced, in case of rolling a steel sheet, etc. CONSTITUTION:In case of rolling a steel sheet 1, etc. by an ordinary rolling stand 3 and rolling stands 2-3-2-1 having each a work roll shifting device, the sheet-thickness profile in the width direction of stock 1 is detected by a sheet-thickness profile meter 4. The rolling-stock information 9 of the sheet width, sheet thickness, material, etc. of stock 1 and the information 10 of rolling time and rolling load, etc. inputted to a roll-profile arithmetic unit 5, and the obtained roll profile 11 is inputted to a roll-shifting amount arithmetic unit 6, and the operated shifting amounts 13-3-13-1 of work rolls are inputted to work-roll shifting devices, to adjust properly the shifting amounts Si of work roll the sheet into the profile having the flat central part and free from edge drop.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a thickness profile control device for a plate material, and the present invention relates to a thickness profile control device for a plate material. By appropriately adjusting the shift amount, the target plate profile is controlled over the entire rolling period.

<Prior Art> It is well known that when rolling a sheet metal material, the cross-sectional profile of the sheet is not necessarily rectangular, and the central portion of the sheet is usually thicker than the edge. In order to solve this problem and make the cross-sectional profile of the plate rectangular, 6 high mill was used.

Several methods have been considered, including work roll cross mills, double chock bender and work roll shifting devices.

Since these backward work roll shift devices can be installed by modifying the 4-high mill relatively easily, many examples of improvements have been proposed for this paralysis (Japanese Patent Publication No. 50-1185).
No. 9, No. 50-12385, No. 51-7635, and Japanese Unexamined Patent Publication No. 135855/1983).

In such a work roll shift device, by aligning the end face of the work roll with the edge of the plate, (1) prevention of edge drop by reducing the local load on the edge of the plate, and (2) improvement of controllability of the work roll bender. The aim is to increase the controllability of the sheet profile other than the edge portion (body crown) and improve the sheet profile using a roll bender.

Furthermore, in Japanese Patent Application Laid-open No. 55-77903,
One side of the shifting work roll is ground into a tapered trapezoid shape, and by effectively utilizing a portion of this taper, the control of the plate profile is even more effective. According to this method, it is also possible to finely control the profile of the edge of the plate by adjusting the roll shift m and the roll profile. However, conversely, there is also a risk that the plate profile may vary locally at the edge of the plate.

Conventionally, once the initial roll profile was determined, the amount of thermal expansion and amount of roll wear were calculated, and then the work roll shift amount and roll venting pressure were calculated to achieve the desired plate profile, and then the work roll shift amount and roll venting pressure were adjusted to those values. It was set.

In addition, in order to improve calculation accuracy, a method is also adopted in which the predicted error of the roll crown estimated from the actual body crown of the rolled plate material is calculated, and the set value is corrected for each rolled material based on this value. was.

(Problem to be solved by the invention) However, in actual operation, the thickness profile of the plate material varies depending on the shift position of the work roll, so the conventional prediction accuracy improvement method as described above is not suitable for dealing with it. was difficult, and improvements were desired.

The present invention was developed in view of the above-mentioned current situation, and an object of the present invention is to propose a novel control device that can accurately control the thickness profile of a plate material to a predetermined profile.

(Means for solving problems) The gist of the present invention is as follows.

That is, a roll profile calculation device that calculates the profile of a work roll in a rolling mill having a work roll shift mechanism from rolled material information and rolling information;
A roll shift start U device that calculates and outputs the shift amount of the work roll from the calculated roll profile, the target value of the thickness profile of the rolled material, and the rolled material information, and a pattern that determines the thickness profile of the rolled material into patterns. This is a plate material thickness profile control device η comprising a recognition device and a roll shift correction amount calculation device which calculates a shift correction amount of a work roll according to the II pattern and outputs it to a roll shift calculation device.

(for production) This invention will be explained in detail below.

First, the roll profile, roll gap profile, and thickness profile, which have important meaning in this invention, will be explained.

1) Roll profile C1 (X) The roll profile C1 (X) is calculated by the following formula (1), and the initial crown Co1 (x), thermal crown (heat crown) Ui (x), and roll wear Cw.
It is expressed as the sum of i(x).

Ci (x) = Cwi (x) + (Ji (
x) +C01(X)...(1) where X: Distance subscript from the roll center position in the trunk length direction 1: Stand No.

In addition, roll wear Cwi(x) and heat crown U
i(X) is determined by the rolling conditions after the roll change. Therefore, it is determined from rolling material information such as plate width, plate thickness, and type of plate, as well as rolling information such as rolling time and rolling load.

2) Roll gap profile Gi(X) Roll gap profile (distribution in sheet width direction) Gi(X)
is the rolling load Pi in the normal 4-high mill.

It is expressed by roll shift force P and roll crown C1 (X), but in a mill that can roll shift, it becomes a function of work roll shift ISi, and together with roll profile C1 (x-s) expressed by equation (1) listed in 1. is expressed as the following equation (2).

Gi (X)=fun (Pi (X)
, P(x).

Ci (x − s), 3i) ・
(2) Here, 81 Distance between the roll centers before and after the work roll shift The work roll shift amount is set so that the plate thickness profile old (×) described later becomes the desired value. However, since the roll gap profile Gi(x) is the main factor in determining the plate thickness profile, it is important to appropriately select the work roll shift MSi in equation (2).

3) Plate thickness profile hi(x) Plate thickness profile hi(x) is a function of the plate thickness profile of the base plate and the roll gap profile Qi(X) of its stand, but the plate thickness profile of the base plate is also Since it is also a function of the roll gap profile in the front stage stand and the plate thickness profile of the base plate, it is finally as shown in the following equation (3).

Old (x) = fun (Gi (x), G;-t
(x).

...) ...(3) Next, the positional relationship between the work roll and the rolled material during rolling when using a pillar type work roll shift device is shown in Fig. 2 a and b, and also by this device. Typical examples of the thickness profile of rolled plate materials are shown in FIGS. 3a to 3, respectively.

Figure 2 a shows the state where the work roll is not shifted,
In this case, there is no difference from conventional rolling, and as shown in Figure 3a, the rolled material usually draws a gentle curve (body crown) that is thicker in the center than the edges, and in addition, the edge part A so-called edge drop having a thickness of about 100 μm or more is generated. If the bender pressure is appropriately selected in this state, the body crown can be made smaller as shown in the figure, but edge drops still remain at the edges.

In this regard, if the work roll is shifted to position both edges of the plate on a part of the roll taper as shown in FIG. 2C, the edge drop can be reduced as shown in FIG. 3C. Then, when the roll shift position is adjusted to an appropriate position, that is, when the value of A is appropriately selected at the position shown in Figure 2, the edge drop is slight and the body crown is reduced, as shown in Figure 3. is the desired thickness profile.

When the roll is further shifted, the edge becomes thicker and takes on the shape shown in FIG. 3e.

In addition, the B [1 file shown in Fig. 3 f has a body crown although there is no edge drop; however, such a shape may be used when the roll shift amount is appropriate but the bender pressure is not appropriate. arise.

If the rolls were uniform as in the initial state, the thickness profile of the plate would match the above explanation, but as rolling actually progresses, local wear of the rolls and expansion due to heat, which is difficult to predict, would occur. It is difficult to set an accurate roll shift amount by calculation alone.

Now, FIG. 1 schematically shows the profile control device according to the present invention together with a rolling machine, and in the figure, number 1 is a rolled material, 2-1 to 2-1.
2-3 are rolling stands each having a work roll shift device, and 3 is a normal rolling stand. In this example, the case where the thickness profile of the rolled material 1 is controlled in the three rear stands is shown. 4 is a plate thickness profile meter that detects the thickness profile in the width direction of the plate at the exit side of the rolling mill.

5 is a roll profile calculation device, 6 is a roll shift amount calculation device, 7 is a thickness profile pattern recognition device, and 8 is a roll shift correction amount calculation device.

The roll profile calculation device 5 calculates the plate width and plate thickness.

Calculate a roll profile 11 from rolled material information 9 such as material and rolling information 10 such as rolling time and rolling load,
It is output to the roll shift amount calculation device 6.

The roll shift amount calculating device 6 calculates the shift lifting of the work roll from the input roll profile 11, thickness profile, roll target value 12, and rolled material information 9, and outputs it to the work roll shift device 13-1 to 13-. Do 3.

Further, the pattern recognition device 7 inputs the signal 14 from the plate thickness profile meter 4, determines which predetermined pattern it corresponds to, and outputs it to the roll shift correction amount calculation device 8.

The roll shift correction correction device 8 calculates a roll shift correction amount appropriate for obtaining a predetermined thickness profile based on the input pattern signal 15, and calculates this value into a roll shift amount calculation device. 6 and output 16 to shift the work roll to the appropriate position.

Next, a specific control method using the above-mentioned thickness profile control device will be explained.

Now, the rolled material 1 is rolled while passing through rolling stands 3.2-3.2-2 and 2-1, and then has a thickness profile meter 4.
The thickness profile in the width direction of the plate is measured by , but in each of the rolling stands 2-3 to 2-1, before the rolled material 1 bites into the stand, the rolling position of the rolling mill, the speed of the rolling motor, and the roll The work roll shift 1-threshold is calculated by the roll shift amount calculation device 6 along with the bend pressure, etc., and this calculated value is output to the roll shift device 13-1 to 13-1.
13-3 and set to a predetermined shift position.

The work roll shift amount is determined by rolling material information 9. It is calculated using the roll profile 11 and the thickness profile target value 12) using equations (1) to (3) above.

The roll shift correction amount 16 is calculated by the roll shift correction amount calculation device, but this calculation differs depending on the pattern recognized by the thickness profile pattern recognition device 7. If the recognition device 7 recognizes the thickness profile pattern as a to c in FIG. 3 above, it increases the work roll shift amount, whereas if it recognizes the thickness profile pattern as e in the same figure, it decreases it.

Since it is difficult to express the relationship between the thickness profile of the edge portion and the amount of roll shift theoretically using a mathematical formula, it is generally determined through experiments.

In addition, in determining the thickness profile, it is difficult to distinguish between those with no edge drops and large body crowns (Fig. 3 f) and those with small body crowns but edge drops (Fig. 3 b). Although both are the same when judged by the thickness of the edge portion and the thickness of the edge portion, the two can be distinguished by the gradient of the thickness of the edge portion.

If the profile pattern is recognized as that shown in FIG. 3(f), the bending pressure will be increased because the shift amount is appropriate.

(Effects of the Invention) Thus, according to the present invention, when rolling a plate material, local and fine thickness profile control can be effectively achieved over the entire rolling period, which greatly contributes to improving the quality of the product.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the method for controlling the thickness profile using the control device according to the present invention, and FIGS. 2 a and 2 b show the relationship between the work roll and the rolled material when using the savings type work roll shift device, respectively. The schematic diagrams illustrating the positional relationships, and Figures 3a to 3f, are all diagrams showing typical thickness profiles of the plate material. 5... Roll profile calculation device 6... Roll shift amount calculation device 7... Pattern recognition device 8... Roll shift correction amount calculation device 9... Rolled material information 10... Rolling information 11...
・Roll profile 12... Thickness profile target value Patent applicant: Kawasaki Steel Co., Ltd. Representative patent attorney Akira Sugimura Daido Patent attorney Ko Sugimura Diagram 3 Procedures Amendment C method) % formula % 1. Case Indication of Patent Application No. 279575 filed in 1982 2 Name of the invention Plate thickness profile control device 3 Relation to the case by the person making the amendment Patent applicant (125) Kawasaki Steel Corporation 4, agent 7 making the amendment Contents (as attached) 1. Lines 16-17 of page 18 of the specification are corrected as follows.

Claims (1)

[Claims] 1. A roll profile calculation device that calculates the profile of a work roll in a rolling mill having a work roll shift mechanism from rolled material information and rolling information, and the calculated roll profile, the thickness profile target value of the rolled material, and the rolling process. A roll shift amount display device that calculates and outputs the work roll shift amount from material information, a pattern recognition device that determines the thickness profile of the rolled material into a pattern, and a work roll shift correction amount according to the recognized pattern. A plate material thickness profile control device comprising a roll shift correction amount calculation device that calculates and outputs the calculated amount to a roll shift amount calculation device.