JPH0985341A - Method and device for separately controlling elongation of tension leveler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the method and device for separately controlling the elongation of a tension leveler capable of reducing the whole line by estimating the intermediate tension of a skin pass mill and the tension leveler. SOLUTION: Laser Doppler meters 11a, 11b, 11c to measure the skin pass mill inlet side velocity V0, the skin pass mill outlet side velocity V1, and the inlet side velocity V2 of an outlet side bridle roll, deflector rolls 13a, 13b to measure the skin pass mill inlet side tension T0, and the inlet side tension T2 of the outlet side bridle roll, and a control device 20 to control the mill elongation percentage εM, the tension T2, the leveler elongation εL, and the intermediate tension T1 are provided. The mill elongation and the leveler elongation percentage are calculated from the differential velocity by the control device, the intermediate tension T1 is estimated from the leveler elongation, the intermesh quantity I.M and the tension T2, and the mill roll rotational speed is changed to control the intermediate tension to the prescribed value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for controlling elongation rate separation of a tension leveler attached to a skin pass mill.

[0002]

2. Description of the Related Art In a cold rolling line for steel sheets, a temper rolling mill (skin pass mill) and a tension leveler may be used together in order to adjust the material of the steel sheet and improve the flatness. In the skin pass mill, one sheet of four-high rolling mill is generally used for sheet materials such as steel sheets for automobiles, and usually elongation of about 0.2% is added in order to avoid elongation at the yield point during press working. The tension leveler continuously imparts plastic elongation to the steel sheet, and is composed of a bridle roll that applies tension and a leveling roll unit that repeatedly applies bending deformation, and the elongation is 0.2 to 0.5% or more. Is to be added.

In recent years, in order to further improve the quality of cold-rolled steel sheets, it has been required to use a skin pass mill and a tension leveler in combination and optimally control each of them, as disclosed in Japanese Examined Patent Publication No. 3-14527. Applications such as 63-10003 and JP-A-2-179320 have already been made.

[0004]

[Problems to be Solved by the Invention] Japanese Patent Publication No. 3-14527
"How to determine the operating conditions of tension leveler"
Although the flatness is improved by the amount of intermesh shown in (A) and the tension of the steel plate, it relates to the independent operation of the tension leveler, and when used in combination with the skin pass mill, it reduces the influence between the two. In addition, it is necessary to perform processing such as keeping the intermediate tension constant, and there is a problem that the total length of the line becomes long.

Further, in Japanese Patent Laid-Open No. 63-10003, “Method and apparatus for temper-rolling shape correction of cold-rolled steel strip”, a tension leveler is provided between a plurality of skin pass mills, and a steel sheet is provided by applying tension by the skin pass mills. Since the shape is corrected and two or more skin pass mills are required, the whole line becomes long and there is a problem that the elongation rates of the skin pass mill and the tension leveler cannot be separately controlled.

Further, in the "tension leveler control system" of Japanese Patent Laid-Open No. 2-179320, an entrance side bridle roll, a skin pass mill, a tension detector and a speed detector, a leveler and an exit side bridle roll are arranged in this order, and a skin pass mill is used. Although the elongation rate and the elongation rate by the tension leveler are separately controlled, the tension detector and the speed detector are placed between the skin pass mill and the tension leveler, so the problem between the skin pass mill and the exit bridle roll becomes longer. There was a point.

Therefore, especially when the tension leveler is attached to the existing temper rolling line (without the tension leveler), the tension roll for detecting the tension cannot be attached, so that the elongation separation of the skin pass mill and the tension leveler is separated. I couldn't control it.

The present invention has been made to solve the various problems described above. That is, the object of the present invention is to detect the elongation ratio of the skin level mill and the tension leveler without detecting the intermediate tension of the skin level mill and the tension leveler, and to control the elongation level of the tension leveler separately, and to shorten the entire line. And to provide a device.

[0009]

According to the present invention, an entrance bridle roll, a skin pass mill, a tension leveler,
The exit side bridle rolls are arranged in order, the speed V0 and the tension T0 on the skin pass mill entrance side, and the speed V on the skin pass mill exit side V
1. Velocity V2 and tension T2 at the exit side bridle roll are measured respectively, and the mill elongation rate εM by the skin pass mill is calculated from the difference between the speeds V0 and V1, and the mill reduction rate of the skin pass mill is adjusted to control the mill elongation rate. εM is controlled, tension T2 is controlled by the rotation speed of the exit side bridle roll, the leveler elongation rate εL by the tension leveler is calculated from the difference between the speeds V1 and V2, and the intermesh amount and tension T2 are adjusted to adjust the leveler elongation rate. By controlling εL, the intermediate tension T1 is estimated from the leveler elongation εL, the intermesh amount, and the tension T2, and the mill roll rotation speed is changed to change the intermediate tension T1.
Is controlled to a predetermined set value, and an elongation rate separation control method for a tension leveler is provided.

According to the preferred embodiment of the present invention, the relationship between the average leveler tension and the leveler elongation εL is obtained in advance, and the intermediate tension T1 is estimated based on the measured tension T2 and the leveler elongation εL. . Further, the speeds V0, V1,
It is better to measure V2 with a laser Doppler meter. Furthermore, it is preferable to set the leveler elongation εL to at least 0.5% or more.

Further, according to the present invention, the elongation separation control device for the tension leveler arranged on the outlet side of the skin pass mill of the temper rolling line in which the inlet bridle roll, the skin pass mill, and the outlet bridle roll are arranged in this order. In addition, the speed V0 at the skin pass mill entrance side, the speed V1 at the skin pass mill exit side, and the exit side bridle roll entrance side speed V
2 and a laser Doppler meter, a deflector roll that measures the tension T0 on the skin path mill entrance side and a tension T2 on the exit side bridle roll entrance side, a mill elongation rate εM, a tension T2, a leveler elongation rate εL, and an intermediate Tension T
And a control device for controlling 1 to calculate the mill elongation rate εM by the skin pass mill from the difference between the speeds V0 and V1, and control the mill elongation rate εM by adjusting the mill reduction amount of the skin pass mill. , The tension T2 is controlled by the rotation speed of the exit side bridle roll, the leveler elongation εL by the tension leveler is calculated from the difference between the speeds V1 and V2, and the leveler elongation ε is adjusted by adjusting the intermesh amount and the tension T2.
By controlling L, leveler elongation εL, intermesh amount,
And an intermediate tension T1 from the tension T2, and the mill roll rotation speed is changed to control the intermediate tension T1 to a predetermined set value.

[0012]

According to the research conducted by the inventors of the present invention, it was revealed that there is a substantially linear relationship between the leveler average tension and the leveler elongation εL in at least the same material. The present invention is based on such a new finding. That is, according to the control method and apparatus of the present invention described above,
Speed V on the skin pass mill entrance side with a laser Doppler meter
0, the speed V1 on the exit side of the skin pass mill, and the speed V2 on the exit side of the bridle roll are directly measured.
Each speed can be measured accurately, and the mill elongation εM and the leveler elongation εL can be accurately calculated from this.

Further, the amount of mill reduction of the skin pass mill is adjusted to control the mill elongation rate εM, the tension T2 is controlled by the rotation speed of the exit side bridle roll, and the leveler elongation rate by the tension leveler is calculated from the difference between the speeds V1 and V2. By calculating εL and controlling the leveler elongation εL by adjusting the intermesh amount and the tension T2, the mill elongation εM and the leveler elongation εL can be separately controlled separately.

Further, based on a linear relationship previously obtained from the leveler elongation εL, the amount of intermesh, and the tension T2,
It is possible to estimate the intermediate tension T1 without actually measuring the intermediate tension, and further change the mill roll rotation speed to control the intermediate tension T1 to a predetermined set value. Moreover, even when the skin pass mill has a sharpness of 3% or less and an edge stretch or a middle stretch, as a result of the test study, the steepness is sufficiently small by setting the leveler elongation εL to at least 0.5% or more. It was found that the value can be reduced.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. In the drawings, common parts are denoted by the same reference numerals. FIG. 1 is a configuration diagram of a temper rolling line equipped with a tension leveler elongation separation control device 10 according to the present invention. In this figure, the temper rolling line is arranged in the order of an inlet side bridle roll 12, a skin pass mill 14, and an outlet side bridle roll 18,
A tension leveler 16 is arranged on the exit side of the skin pass mill 14.

In this figure, the entrance side bridle roll 12 and the exit side bridle roll 18 are provided with independent drive devices, but the present invention is not limited to this, and they are mechanically connected to each other. It may be a mechanical tie rod type drive. Also, skin pass mill 14
Is a single four-high rolling mill in this figure, and has a rolling capacity capable of adding elongation of at least 0.2% or more in order to avoid elongation at yield during press working. The skin pass mill 14 can adjust the rotation speed and the amount of reduction like the conventional mill. Further, the tension leveler 16 can freely adjust the intermesh amount (hereinafter, referred to as IM) shown in FIG.

The tension level separation control device 10 of the tension leveler of FIG.
And a delivery speed V1 and a delivery speed V2 of the exit bridle roll 18 are measured by a laser Doppler meter 11a,
11b, 11c and the tension T on the entry side of the skin pass mill 14
0, the deflector rolls 13a and 13b for measuring the entrance tension T2 of the exit bridle roll 18, respectively, and the controller 20 for controlling the mill elongation εM, the tension T2, the leveler elongation εL, and the intermediate tension T1. There is.

Incidentally, in this figure, there is no deflector roll for measuring the tension T1 on the exit side of the skin pass mill, so that the existing temper rolling line (without the tension leveler) can be provided with the tension leveler. Yes, the entire line can be shortened.

FIG. 2 is an explanatory diagram of a control method by the control device 20. Laser Doppler meter 11a, 1 shown in FIG.
By 1b and 11c, the speed V0 on the skin pass mill entrance side,
The speed V1 on the exit side of the skin pass mill and the entrance speed V2 of the exit bridle roll are respectively measured, and at the same time, the tension T0 and the tension T2 are respectively measured by the deflector rolls 13a and 13b. 20
Is input to

In the control device 20, first, (A) speed V0
From the difference between V1 and V1
M is calculated and the mill reduction of the skin pass mill 14 is adjusted to control the mill elongation εM. With this, the mill elongation εM can be controlled independently, and for example, the mill elongation ε
By maintaining M at about 0.2%, it is possible to avoid yield point elongation during press working of the steel sheet.

Next, (B) the tension T2 is controlled by the rotation speed of the exit side bridle roll 18, and (C) the speeds V1 and V.
From the difference of 2, the leveler elongation ε by the tension leveler 16 is ε
L, and the intermesh amount I.L. The leveler elongation εL is controlled by adjusting M and the tension T2. By this control,
The leveler elongation εL can be controlled independently of the mill elongation εM. For example, the leveler elongation εL is about 0.2.
It can be set to about 0.5% to secure the flatness of the steel sheet and prevent an excessive elongation rate.

Next, as shown in (C), the leveler elongation εL, the intermesh amount I.D. The intermediate tension T1 is estimated from M and the tension T2, and the mill roll rotation speed is changed to control the intermediate tension T1 to a predetermined set value. By this control, the intermediate tension T1 can be controlled to a free setting value suitable for the skin pass mill 14 and the tension leveler 16, and optimal control of both the skin pass mill 14 and the tension leveler 16 can be performed. Further, by estimating the intermediate tension T1, a deflector roll for measuring the tension T1 on the exit side of the skin pass mill becomes unnecessary, and the existing temper rolling line (without the tension leveler) can be provided with the tension leveler. Yes, you can shorten the whole line.

The controls (A) to (C) shown in FIG. 2 may be sequentially performed at appropriate time intervals, or may be substantially simultaneously performed.

FIG. 3 shows test results showing the relationship between the leveler average tension T _s and the leveler elongation εL. As shown in this figure, between the leveler average tension T _s = (T1 + T2) / 2 and the leveler elongation εL, εL = aT _s + b (when the entrance tension T1 is constant for the same steel plate. There is a linear relationship represented by the general formula (a and b are constants). Therefore, the relationship between the leveler average tension T _s and the leveler elongation εL can be obtained in advance for the target steel sheet, and the intermediate tension T1 can be estimated based on the measured tension T2 and the leveler elongation εL.

FIG. 4 shows the test results showing the relationship between the leveler elongation and the steepness. Here, the steepness is one of the criteria for evaluating the flatness, and when the pitch of the unevenness is p and the wave height is h as shown in FIG. 5B, h / p is the steepness. λ
Call it. It is desirable that the steepness λ be 0.5% or less, but in normal cold rolling (without a leveler), a maximum of about 2-3% may occur.

As is clear from FIG. 4, when medium elongation occurs in the cold rolling on the upstream side, the steepness can be made zero by setting the leveler elongation to about 0.4% or more,
If ear growth occurs, increase the leveler growth by 0.5%.
By setting the above, the steepness can be made a sufficiently small value (about 0.3% in this figure), and by setting the leveler elongation to be 0.57% or more, the steepness can be made zero. Recognize. That is, regardless of whether middle stretch or edge stretch occurs in the cold rolling on the upstream side, the steepness can be reduced to a sufficiently small value by setting the leveler elongation εL to at least 0.5%. With such control, the flatness of the steel sheet can be maintained constantly.

As described above, according to the control method and apparatus of the present invention, the speed V0 on the skin pass mill entrance side, the speed V1 on the skin pass mill exit side, and the exit side bridle roll entrance speed V2 are measured by the laser Doppler meter. Is directly measured, each speed can be precisely measured, and the mill elongation εM and the leveler elongation εL can be accurately calculated from this.

Further, the amount of mill reduction of the skin pass mill is adjusted to control the mill elongation rate εM, the tension T2 is controlled by the rotation speed of the exit side bridle roll, and the leveler elongation rate by the tension leveler is calculated from the difference between the speeds V1 and V2. By calculating εL and controlling the leveler elongation εL by adjusting the intermesh amount and the tension T2, the mill elongation εM and the leveler elongation εL can be separately controlled separately.

Further, based on the linear relationship previously obtained from the leveler elongation εL, the amount of intermesh, and the tension T2,
It is possible to estimate the intermediate tension T1 without detecting the intermediate tension, and further change the mill roll rotation speed to control the intermediate tension T1 to a predetermined set value. Moreover, even when the skin pass mill has a sharpness of 3% or less and an edge stretch or a middle stretch, as a result of the test study, the steepness is sufficiently small by setting the leveler elongation εL to at least 0.5% or more. It can be reduced to a value.

The present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

[0031]

As described above, the method and apparatus for controlling the elongation separation of the tension leveler of the present invention separately control the elongation rate of the skin level mill and the tension leveler without detecting the intermediate tension between the skin level mill and the tension leveler. It has excellent effects such as being able to shorten the whole line.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a temper rolling line equipped with a tension leveler elongation separation control device according to the present invention.

FIG. 2 is an explanatory diagram of a control method by a control device.

FIG. 3 is a test result showing the relationship between the leveler average tension and the leveler elongation.

FIG. 4 is a test result showing a relationship between leveler elongation and steepness.

5 (A) Intermesh amount (IM) and (B)
It is explanatory drawing of steepness.

[Explanation of symbols]

 10 Extension level separation control device for tension leveler 11a, 11b, 11c Laser Doppler meter 12 Bridle roll for entry side 13a, 13b Deflector roll 14 Skin pass mill (temper rolling mill) 16 Tension leveler 18 Outgoing bridle roll 20 Control device V0 Skin pass mill Inlet speed V1 Skin pass mill Outlet speed V2 Outlet bridle roll Inlet speed T0 Skin pass mill Inlet tension T1 Skin pass mill Outlet tension T2 Outgoing bridle roll Inlet tension εM Mill elongation εL Leveler elongation Rate I. M intermesh amount λ steepness (= h / p)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Reiji Kizaki 1 Shinshinarahara-cho, Isogo-ku, Yokohama-shi, Kanagawa Ishi Kawashima Harima Heavy Industries Ltd. Yokohama Engineering Center (72) Kazuyuki Sato Isogo, Yokohama-shi, Kanagawa Shin-Nakahara-cho 1-ku, Ishikawajima-Harima Heavy Industry Co., Ltd. Yokohama Engineering Center (72) Inventor Hisashi Honjo Shin-Nakahara-cho, Isogo-ku, Yokohama, Kanagawa Prefecture 1 Kawaishijima Harima Heavy Industries Co., Ltd. Yokohama Engineering Center ( 72) Inventor Masao Mikami, 1 Shinshinarahara-cho, Isogo-ku, Yokohama-shi, Kanagawa, Ishikawajima-Harima Heavy Industries Co., Ltd. Technical Research Institute (72) Seikan Kuchihiro Shin-Nakahara-cho, Isoko-ku, Yokohama, Kanagawa Corporate Research Laboratory (72) Inventor Shogo Tomita Steel, Fukuyama City, Hiroshima Prefecture One address NKK stock company Fukuyama the laboratory town

Claims (5)

[Claims] 1. An entrance side bridle roll, a skin pass mill, a tension leveler, and an exit side bridle roll are arranged in order, and a speed V0 and a tension T0 on the entrance side of the skin pass mill, a speed V1 on the exit side of the skin path mill, and an exit side bridle roll entrance side. The speed V2 and the tension T2 of each are measured, the mill elongation εM by the skin pass mill is calculated from the difference between the speeds V0 and V1, and the mill elongation εM is controlled by adjusting the mill reduction of the skin pass mill. The tension T2 is controlled by the rotation speed of the roll, the leveler elongation rate εL by the tension leveler is calculated from the difference between the speeds V1 and V2, and the leveler elongation rate εL is controlled by adjusting the intermesh amount and the tension T2. εL, intermesh amount, and tension T
2. The tension level separation control method for a tension leveler, wherein the intermediate tension T1 is estimated from 2 and the mill roll rotation speed is changed to control the intermediate tension T1 to a predetermined set value. 2. The intermediate tension T1 is estimated based on the tension T2 and the leveler elongation εL actually measured from the relationship between the leveler average tension and the leveler elongation εL. 2. The tension level separation elongation control method according to 1. 3. The elongation level separation control method for a tension leveler according to claim 1, wherein the speeds V0, V1 and V2 are measured by a laser Doppler meter. 4. The leveler elongation εL is at least 0.
The elongation level separation control method of the tension leveler according to claim 1, wherein the elongation level separation control method is set to 5% or more. 5. An elongation separation control device for a tension leveler arranged on the outlet side of a skin pass mill of a temper rolling line in which an inlet side bridle roll, a skin pass mill, and an outlet side bridle roll are arranged in that order. Laser Doppler meter for measuring the speed V0 on the entrance side, the speed V1 on the exit side of the skin pass mill, and the speed V2 on the entrance side of the exit bridle roll, and the tension T0 on the entrance side of the skin pass mill and the tension T2 on the exit side of the bridle roll. And a controller for controlling the mill elongation rate εM, the tension T2, the leveler elongation rate εL, and the intermediate tension T1. The control apparatus controls the difference between the speeds V0 and V1 by the skin pass mill. Elongation rate εM is calculated, and the mill reduction rate of the skin pass mill is adjusted to control the mill extension rate εM. The tension T2 is controlled by the rotation speed of the roll, the leveler elongation rate εL by the tension leveler is calculated from the difference between the speeds V1 and V2, and the leveler elongation rate εL is controlled by adjusting the intermesh amount and the tension T2, and the leveler elongation rate is controlled. The intermediate tension T1 is estimated from εL, the amount of intermesh, and the tension T2, and the intermediate tension T1 is changed by changing the mill roll rotation speed.
Is controlled to a predetermined set value, an elongation rate separation control device for a tension leveler.