JP3229437B2 - Shape control method in sheet rolling - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shape control method in sheet rolling, and more particularly to a method of controlling a sheet shape by adjusting a shape control means in a sheet size changing process during cold rolling.

[0002]

2. Description of the Related Art In general, it is needless to say that a rolled plate preferably has good shape, especially flatness, but in recent years, in particular, demands on the shape of a rolled plate have become more severe. . Generally, the plate shape control method is as follows:
It is mainly performed by adjusting the bending, bending, or crown of the roll. As the control means, for example, various methods such as a work roll bender, an intermediate roll bender, a shift of an intermediate roll, and a flow rate adjustment of a roll coolant have been proposed. Usually, these control means detect the plate shape on the exit side of the rolling mill during rolling, and perform feedback control based on the information.

When the thickness or width of a rolled material (for example, a hot-rolled coil) is changed in cold rolling, an operation amount (for example, a roll bending force or the like) is determined based on the material or rolling conditions of the rolled material. Presetting of the intermediate roll shift amount). In particular, a rolling mill having a cubic or sine curve profile in the intermediate roll (for example, CVC (Continuous Variable Cr)
In the case of a TC mill (trade name of Kawasaki Heavy Industries, Ltd.) that makes full use of the technology called “own”, various mechanical crowns can be continuously formed by controlling the position of one type of unique crown roll in the axial direction. Utilizing the fact that it can be generated, presetting is mainly performed using the shift of the intermediate roll.

That is, when changing the thickness or width of a rolled material (for example, a hot rolled coil), the operation amount of the intermediate roll shift amount is preset based on the material of the rolled material and the rolling conditions. However, at the time of this preset, since the speed of the intermediate roll shift is slow, the shift needs to be started gradually before the plate size is changed.

[0005]

However, by performing the intermediate roll shift as described above, there is a problem in that the sheet shape of the rolled material before the preceding sheet size change is disturbed. As means for preventing such shape disturbance due to the intermediate roll shift at the time of presetting, for example, Japanese Patent Application Laid-Open No. Sho 54-21948 uses the fact that the intermediate roll shift position and the work roll bending force are in a linear proportional relationship. Then, a method of operating the work roll bending force according to the shift position of the intermediate roll, and JP-A-62-158512 predicts a change in shape caused by the intermediate roll shift by a model formula. 0 change
A method for adjusting the bending force of the work roll vendor and the intermediate roll vendor has been proposed.

However, the intermediate rolls used in these conventional examples all have a flat profile, and are intended for intermediate rolls provided with a cubic or sine curve profile which is the object of the present invention. Therefore, the change in the plate shape due to the preset roll shift is not clarified, and therefore, a method of correcting the change in the shape cannot be determined.

[0007] An object of the present invention is to provide a shape control method in sheet rolling that solves the above-mentioned problems of the prior art.

[0008]

SUMMARY OF THE INVENTION According to the present invention, there is provided a method for controlling a sheet thickness or a thickness during rolling using a cold rolling mill in which an intermediate roll having a cubic or sine curve profile is disposed between a work roll and a backup roll. In the method of controlling the plate shape by adjusting the shape control means in the process of changing the plate size of the plate width, utilizing the characteristics of the change in the shift amount of the intermediate roll and the change exerted on the plate shape by the intermediate roll bending, It is characterized in that the change in the plate shape that occurs when performing the intermediate roll shift before the plate size change is corrected in advance using the intermediate roll bending force, and then control is performed so that the shape after the plate size change becomes the target value. This is a shape control method in sheet rolling.

[0009]

The present inventors used a rolling mill in which an intermediate roll having the above-mentioned cubic curve or sine curve profile was arranged, to change the plate shape caused by the intermediate roll shift amount, the intermediate roll bending force, and the like. As a result of conducting an experiment and comparing the change in the plate shape caused by the work roll bending force, the pattern of the shape change caused by the intermediate roll shift and the pattern of the shape change caused by the intermediate roll bending force are extremely similar. Was found.

That is, the shift amount S of the intermediate roll is set to ΔS
It was found that, when only the variation was made, the variation ΔF _I of the intermediate roll bending force F _I required to obtain the same shape had a one-to-one linear relationship as shown in FIG. Therefore, if control is performed so as to correct the change ΔS in the shape at the time of presetting the intermediate roll shift using only the intermediate roll bending force F _I using the relationship of FIG. 3, a rolled material having a good flatness is rolled. be able to.

Therefore, according to the present invention, the disturbance of the shape generated in the preceding rolled material due to the presetting of the intermediate roll shift when the plate size is changed is corrected by operating the intermediate roll bending force in advance. It is possible to roll a plate having a good shape over the entire length of the rolled material.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a schematic configuration of a cold rolling mill for carrying out the present invention, and the rolling mill comprises a pair of upper and lower work rolls 1 and 2 and a pair of upper and lower backup rolls 3 and 4. A pair of upper and lower intermediate rolls 5 and 6 that can move in the direction and have a cubic curve or sine curve profile are arranged.

[0013] axial movement device (not shown) at one end of each of the upper and lower intermediate rolls 5 and 6 are connected, and for applying roll bending force F _I to both intermediate rolls in between its ends A roll bender (not shown) is provided. Further, a roll bender (not shown) for applying a roll bending force _FW to both work rolls is provided between both ends of the upper and lower work rolls 1 and 2. On the other hand, a rolling device (not shown) for applying a rolling load P / 2 to both ends of the upper and lower backup rolls 3 and 4 is attached to a roll housing (not shown).

In this type of rolling mill, the roll crowns of the work rolls 1 and 2 can be arbitrarily changed by changing the upper and lower intermediate rolls 5 and 6 by the position S with respect to the center line of the rolling mill. The flatness can be obtained for the rolled material 7 having various widths. Now, a case of rolling the next rolling material subsequent to the rolling of the rolled material for example a plate width W _B of the plate width W _A, will be described with reference to FIG.

As shown in FIG. 1, a rolled material having a sheet width W _A has a rolling load P _A , a work roll bending force F _WA ,
Also, intermediate roll shift S _A , roll bending force F _IA
Are rolled by the conditions during its rolling, rolling load P _B of the next rolling material made plate width W _B, the work roll bending force F _WB, intermediate roll shift position S _B, the intermediate roll bending force F _IC is deformed It is calculated in consideration of resistance, plate size (plate width, plate thickness), roll rolling distance, thermal crown, etc.

[0016] Thus, at time t ₁ the rolling of the rolled material in the plate width W _A is close to end, the output control signal to the mill from a control device (not shown) is, intermediate rolls 5 and 6 on the roll shift position S _B Start shifting toward At this time, the shape change caused by the intermediate roll shift is canceled simultaneously with the start of the movement of the intermediate roll shift according to the relationship of FIG. _Operate in direction F _IB .

[0017] In time t _2, the next intermediate roll shift position S _B, and intermediate roll bending force F _IB
When the intermediate roll shifting and intermediate roll bending force is temporarily each S _B, it is held in the F _IB. And at the same time, the rear end of the rolled material having the width W _A and the width W _B
Of the rolled material passes through the rolling mill.

Time t immediately after the weld passes through the rolling mill
In _3, is operated and the roll gap control device and the roll vendors, the target value of the shape with respect to the rolled material in the plate width W _B, i.e. rolling load in P _B, the intermediate roll bending force F
_{The IC} and work roll bending force are changed to _FWB . Then, it carried out subsequently is rolled in the rolling material in the plate width W _B.

[0019]

As described above, according to the present invention,
Good shape accuracy of the rolled sheet can be ensured over almost the entire length of the rolled material, and cut-off portions due to defective shapes at the leading and trailing ends of the rolled material are reduced, and the yield can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a schematic configuration of a cold rolling mill for carrying out the present invention.

FIG. 2 is a characteristic diagram illustrating the operation of each part of a rolling mill when the method of the present invention is performed.

FIG. 3 is a characteristic diagram showing a relationship between an intermediate roll bending force change amount and an intermediate roll shift amount change amount.

[Explanation of symbols]

 1,2 Work roll 3,4 Backup roll 5,6 Intermediate roll 7 Rolled material

──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Tomio Komatsu 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Kawasaki Steel Corporation Chiba Works (72) Inventor Eisuke Kawasumi 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Kawasaki Steel (56) References JP-A-63-177909 (JP, A) JP-A-6-55208 (JP, A) JP-A-62-158512 (JP, A) JP-A-54-21948 (JP) JP, A) JP-A-6-154821 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B21B 37/00-37/78

Claims (1)

(57) [Claims] 1. A method of changing a sheet thickness or a sheet width during rolling using a cold rolling mill in which an intermediate roll having a cubic or sine curve profile is arranged between a work roll and a backup roll. In the method of controlling the plate shape by adjusting the shape control means in the process, the change of the shift amount of the intermediate roll and the characteristics of the change on the plate shape due to the intermediate roll bending are used to change the intermediate roll shift before the plate size is changed. A shape control method in strip rolling, wherein a change in the shape of the sheet generated when performing the above is corrected in advance using the intermediate roll bending force, and then the shape after the change in the sheet size is controlled so as to be a target value. .