JP2002126811A - Cold rolling equipment and cold rolling method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cold rolling equipment and a cold rolling method therefore capable of manufacturing a product having a prescribed plate thickness distribution and a less edge drop of the plate even in inexpensive equipment. SOLUTION: A cold rolling equipment is provided sequentially with a delivery reel 6 for a steel strip 1, a welding machine 2, a looper 3 and a continuous type cold rolling mill 5 and has the cold rolling equipment and the cold rolling method using the same equipment having a plate profile measuring device 7 to measure the plate thickness distribution in the width direction of the steel strip provided between the delivery reel and the looper, a crown converting device 8 to calculate a plate crown value based on the measurement value by the plate profile measuring device, a computing device 11 of the control output to control one or more among a roll cross angle of the rolling mill, a roll shift volume, a roll bender volume and a roll crown volume based on the output from the converting device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cold rolling equipment capable of producing a product having a predetermined thickness distribution with a small edge drop of a steel strip even if the equipment is inexpensive, and a cold rolling equipment for a steel strip using the same. To a hot rolling method.

[0002]

2. Description of the Related Art In recent years, various developments or improvements have been made in various fields for the purpose of increasing the precision of steel product dimensions or improving the yield in the steel product manufacturing process. Also in the field of cold rolling, a profile control technique for the purpose of improving the thickness accuracy in the strip width direction has been actively developed.

[0003] Japanese Patent Application Laid-Open No. 11-244920 discloses that, in an upstream stand in which the overall profile of a rolled material can be easily controlled, the center plate thickness is accurately controlled, and that the rolled material on the exit side of the upstream stand is predicted by predicting the rolling in the downstream. A technique for forming a profile is disclosed. According to the present technology, the edge drop amount at the intermediate stand can be appropriately adjusted, and the elongation distribution of the rolled material at the final stand can be appropriately controlled.

Further, by controlling the thickness in cooperation with each other while predicting the influence of the control devices, it is possible to perform good profile control. Japanese Patent Application Laid-Open No. 10-5837 discloses a mechanical plate crown for realizing a desired plate shape at the exit side of each cold rolling mill based on the distribution of the plate thickness of the material supplied to the rolling equipment in the plate width direction. There is disclosed a technique of obtaining a target value and performing shape control based on a measured value of a roll profile and a measured value of a rolling load of each cold rolling mill. In the present technology, an example is shown in which a sheet profile measuring device capable of measuring a sheet thickness distribution in a width direction of a steel strip is installed on an inlet side of a cold rolling mill, and a sheet thickness measuring device is installed between all stands. .

Japanese Unexamined Patent Publication No. Hei 2-37908 discloses a timing for outputting a work roll bending force based on a sheet crown or the like detected by a sheet crown detector installed on the entry side of a rolling mill, and controlling the timing in accordance with this timing. A method for doing so is disclosed. According to the present technology, feedforward control becomes possible, and high-accuracy sheet crown control is made possible.

[0006]

However, any of the techniques disclosed in the above publications requires a sheet profile measuring device immediately before the rolling mill, and if the thickness distribution or the sheet crown is to be measured, the entire width of the steel strip is required. It is necessary to install a continuous plate profile measuring device capable of measuring the plate thickness over the entire area or measuring the plate thickness of at least the central portion and one plate end. Alternatively, there is a method of temporarily stopping the feeding of the steel strip, moving the sheet profile measuring device in the width direction of the steel strip, and measuring the thickness distribution in the width direction. However, a plate profile measuring device that continuously measures the thickness of the center and the end of the steel strip is expensive, and in the case of a method of temporarily stopping the feeding of the steel strip on the upstream side of the rolling mill, There is a problem that the plate thickness of the product does not fall within the dimensional tolerance, resulting in deterioration of the yield.

Further, in order to manufacture a product having high plate thickness accuracy, the influence of the wedge of the steel strip cannot be ignored. However, the technology disclosed in any of the publications does not deal with the wedge of the base material. Not considered. In order to measure and control the wedge, a device that can measure the thickness of both ends of the strip in the width direction of the steel strip and a control to match the reduction amount at both ends of the rolling roll based on the measured value by the device It is necessary to activate the means. However, in the same way as the above-described plate profile measuring device, a profile measuring device capable of continuously measuring the plate thickness of both plate ends is required, and at least three points of measurement are required together with the measurement of the plate thickness distribution. Yes, the problem of equipment costs is even greater.

[0008] Here, the plate crown refers to the difference in plate thickness between the plate center and the plate end (average value of one plate end or both plate ends). The wedge refers to a thickness difference within a certain distance from both ends of the steel sheet, and usually refers to a thickness difference at a position of about 25 mm from both ends of the steel sheet. The wedge may be generated due to a difference in the amount of reduction between the left and right rolls, or may be generated due to a difference in a gap between the left and right rolls due to abrasion of the roll. In cold rolling, in addition to the difference between the left and right rolling reductions, if there is a wedge in the base material, this remains in the product after cold rolling, and quality problems are particularly problematic in products requiring high plate thickness accuracy. Becomes
The present invention has been made in order to solve the above-described problems in the related art, and by installing a plate profile measuring device at an appropriate position, even if the equipment is inexpensive, the edge drop is reduced to a predetermined value. An object of the present invention is to provide a cold rolling facility capable of manufacturing a product having a thickness distribution and to provide an appropriate cold rolling method for a steel strip using the same.

[0009]

The gist of the present invention is as follows.
The present invention relates to the cold rolling equipment of (1) to (3) and the method of cold rolling a steel strip described in (4) to (6).

(1) In a cold rolling facility in which a steel strip take-out reel, a welding machine for connecting the steel strip, a looper for storing the steel strip, and a continuous cold rolling mill are sequentially arranged, the carry-out reel and the looper are provided. Provided between the, a plate profile measuring device that measures the thickness distribution of the steel strip in the width direction, a crown conversion device that calculates the crown value of the plate based on the measurement value by the plate profile measuring device, Based on the output from the crown conversion device, the roll cross angle of the rolling mill,
A cold rolling mill having a control output arithmetic unit for controlling one or more of a roll shift amount, a roll bender amount, and a roll crown amount.

(2) A plate profile measuring device for measuring the thickness distribution of a steel strip in the width direction is provided between a welding machine for connecting the steel strip and a looper for storing the steel strip. The cold rolling equipment according to 1. (3) The cold plate according to (1), wherein the plate profile measuring device for measuring the thickness distribution in the width direction of the steel strip is provided between the steel strip take-out reel and the welding machine connecting the steel strip. Rolling equipment.

(4) Using the cold rolling equipment described in (1), (2) or (3) above, measuring the thickness distribution in the width direction of the steel strip while the feeding of the steel strip is stopped. A cold rolling method for a steel strip, wherein a thickness distribution in a width direction of the steel strip is measured by a sheet profile measuring device.

(5) In addition to the measurement of the thickness distribution of the steel strip in the width direction, the strip crown of the steel strip is measured continuously, and the crown control range is larger at the time of set-up than the control means at the time of steady rolling. The cold rolling method for a steel strip according to the above (4), wherein the control means uses a control means having a smaller crown control range at the time of steady rolling than the control means at the time of set-up.

(6) In addition to the measurement of the thickness distribution in the width direction of the steel strip, the strip crown of the steel strip is continuously measured, and the response speed of the crown control is higher than that of the control means at the time of steady rolling during setup. (4) The cold rolling method for a steel strip according to the above (4), wherein a control means having a fast response time is used at the time of steady rolling, and a control means having a slower response speed of the crown control than the control means at the time of set-up is used.

Incidentally, the roll crown amount in the above (1) means:
The crown amount of a roll having a function of changing the crown of the roll itself by means such as hydraulic pressure.

The present invention has been made by paying attention to the characteristics of a rolling facility having a welding machine for connecting a steel strip to the entry side of a rolling mill and the installation position of a plate profile measuring device.
By providing the plate profile measuring device at an appropriate position, the plate crown is measured in a state where the line is stopped and without causing a change in the plate thickness of the product, and the control means is controlled based on the crown, so that the edge drop is reduced to a predetermined value. Manufacture products with thickness distribution. For that purpose, it is necessary to install the sheet profile measuring device on the entry side according to the purpose at a place where the sheet profile measuring device can be installed at low cost with respect to the existing continuous cold rolling mill, and measure the sheet crown. There is.

The present inventors have found the following facts and completed the present invention.

(A) In order to satisfy the above requirements, it is optimal to install the plate profile measuring device between the take-out reel and the looper.

(B) As a result of investigating the steel plate profile in detail after installing the plate profile measuring device at the optimum position, the crown of the base metal may differ greatly from steel band to steel band. Changes slowly in a relatively narrow range.

Here, the steel strip means a base material for cold rolling, particularly a hot-rolled steel sheet. Further, each steel strip means one coil of the base material for cold rolling, and inside the steel strip means one coil.

(C) A control means having a relatively large control range is used for controlling the product crown at the time of setup, and a control means having a relatively small control range is used for controlling the sheet crown during steady rolling. As a result, a steel strip having a sufficiently small edge drop and a predetermined thickness distribution can be manufactured without excessive capital investment.

(D) The change of the base material sheet crown is sufficiently gentle in the steel strip, and a control means having a relatively fast response is used at the time of set-up, and a control means having a slow response is used at the time of steady rolling. This makes it possible to produce a steel strip having a predetermined thickness distribution with a small off-gauge and a sufficiently small edge drop at the front and rear ends of the steel strip.

[0023]

Embodiments of the present invention will be described below.

FIG. 1 is a schematic view of a first embodiment of the rolling equipment having a plate profile measuring device between a welding machine and a looper according to the present invention. A welding machine 2 for connecting a steel strip to the entry side of a rolling mill 5 and a looper 3 for storing the steel strip are provided, and a thickness distribution in the width direction of the steel strip is measured between the looper and the welding machine. 1 shows a cold rolling facility provided with a plate profile measuring device 7 to be used.

The steel strip 1 carried out from the steel strip take-out reel 6 is supplied to the looper 3 after being welded by the welding machine 2. By restricting the speed of the looper 3, the feeding of the steel strip 1 upstream of the looper 3 to the looper 3 can be reduced or stopped during rolling. The measurement device 7 measures the thickness distribution in the width direction.

The sheet profile measuring apparatus is a method in which the measuring apparatus is run in the width direction of the steel strip to measure the thickness of the steel strip 1 at a plurality of positions in the sheet width direction, or at one position in the sheet width direction. May be installed at a plurality of locations in the board width direction. Further, any of a contact method in which measurement is performed by bringing a measurement roller or the like into contact with a steel strip or a non-contact method in which measurement is performed using radiation or the like may be used. The measured value of the thickness distribution is sent to the crown converter 8, and based on the difference in the width direction between the measured thickness values near both ends of the steel strip,
A wedge is detected. In addition, the plate profile measuring device 7
When traveling in the width direction, the distribution of the thickness in the entire width direction is measured, and the difference in thickness between the central portion and the edge portion (the thickness difference between the central portion and one end portion or the central portion thickness and both ends) Difference from the average thickness of the parts)
Is used to calculate the plate crown. As described above, by installing the plate profile measuring device 7 capable of measuring the plate thickness in the width direction of the steel strip upstream of the looper 3 of the continuous rolling mill, both the wedge and the crown of the steel strip can be accurately measured. be able to.

Further, by providing the plate profile measuring device 7 between the looper 3 and the welding machine 2, sufficient time can be taken for the steel strip 1 to reach the rolling mill 5. It is possible to reflect the plate crown value measured by the above.

FIG. 2 is a schematic view of a rolling equipment having a plate profile measuring device 7 between a steel strip take-out reel 6 and a welding machine 2 according to a second embodiment of the present invention. Steel strip 1 is welder 2
During the waiting time until the connection is established, the sheet profile measuring device 7 is run in the steel strip width direction, the thickness distribution of the steel strip in the sheet width direction is measured, and the measured value is sent to the crown conversion device 8, The wedge is detected from the thickness difference near both ends of the steel strip. In addition, the ability to accurately measure the sheet crown value and the ability to reflect the sheet crown value on the setup of rolling conditions are the same as in the first embodiment.

The sheet crown value used for setting (measured when the steel strip is stopped near the coil tip) and a sheet profile measuring device 7 (for example, a sheet crown measuring device) capable of measuring the sheet thickness distribution in the sheet width direction. The strip crown values of the steel strip continuously measured in the stationary part are sent to the crown conversion device 8, respectively. Based on the difference between the two, the control output arithmetic unit 11 issues operation commands to control means of the rolling mill, such as the roll cross angle, roll shift amount, roll bender amount, and variable roll crown of the rolling mill 5. A known method can be used to calculate these control amounts and control the operation sequence. In the case of the first and second embodiments, a plate profile value provided between the welding machine 2 and the looper 3 or between the steel strip unloading reel 6 and the welding machine 2 is used as the set sheet crown value. The value (setup value) obtained when the steel strip 1 is stopped by the device 7 is applied. This is because the plate crown value may vary greatly from coil to coil, but there is no significant change within the coil.

The same applies to the wedge reduction. That is, the wedge value measured by the plate profile measuring device 7 in the stopped state of the steel strip 1 and the wedge value continuously measured in the plate width direction by the plate profile measuring device 7 in the plate width direction in the steady portion. , A correction operation command is issued to control means such as the roll shift amount, the roll bender amount, and the leveling of the rolling mill 5.

FIG. 3 shows another rolling method according to the present invention, which has a mechanism for comparing a measured value obtained by a plate profile measuring device between a steel strip take-out reel and a welding machine and a measured value obtained by a plate thickness measuring device immediately before a rolling mill. It is a schematic diagram of equipment.

The continuous measurement method using the plate profile measuring device 7 includes a plate profile measuring device 7 near the end of the steel strip 1.
There is a method in which the thickness is fixed and the thickness is measured continuously. In this case, the sheet crown value may be obtained from the deviation of the sheet thickness at the center portion of the steel strip from the set value of the sheet thickness, or may be provided immediately before the rolling mill 5 as shown in FIG. The same value in the longitudinal direction of the steel strip by tracking the thickness measured at the center of the strip width measured by the strip thickness measuring device 4 and the thickness measured by the strip profile measuring device 7 with the movement of the steel strip. May be obtained by collation.

Further, a description will be given of a third embodiment of the present invention in which a plurality of control means are appropriately operated according to their control characteristics.

FIG. 4 is a schematic diagram of a rolling facility that performs control according to the characteristics of the control means. In a rolling mill having a plurality of control means, a sheet crown value continuously measured by a sheet profile measuring device 7 during steady rolling and converted into a crown value by a sheet crown converting device 8 is provided at a tip end of the steel strip 1. When the control is performed based on the deviation from the sheet crown value measured during the stop of the steel strip and used during the setup, it is desirable to perform the following. Here, the sheet crown conversion device has a function of continuously calculating a measured value of the sheet crown while the steel strip is stopped over the entire length of the steel strip. As the simplest method, there is a method in which the initially measured plate crown value is held as it is.

The control command output via the sheet crown converting device 8 and the control output calculating device 11 is sent to the control means characteristic comparing device 10 to select an appropriate control means and determine the control amount. For example, it is desirable to use a control means having a large crown control range at the time of set-up, and a control means having a small crown control range at the time of steady rolling. The specific usage is as follows.

In a rolling mill 5 having a cross rolling mechanism (for example, a pair cross rolling mechanism) and a roll bender mechanism (for example, a work roll bender mechanism) capable of crossing the roll axis, when the cross rolling mechanism has a larger crown control range, It is desirable to use a cross-rolling mechanism during setup, and to use a work-roll bender mechanism for sheet crown control during steady rolling.

Here, the magnitude of the control range can be compared and determined as follows. In the present invention, the roll crown amount when the control means is operated so as to maximize the mechanical gap formed between the rolls (hereinafter referred to as the mechanical crown amount) is referred to as a control range.

For example, in a cross rolling mill, the operating range of the roll cross angle is 0 ° to 1 °, and the maximum is 1 °.
The amount of the mechanical crown formed when
μm. On the other hand, the operation range of the work roll vendor is 0 to 50 tons / chock, and the maximum
Assuming that the mechanical crown amount formed when turning on / chock is 200 μm, the roll cross angle control has a larger control range in this case.

When focusing on the response speed, it is desirable to perform the following. Here, the fast response speed means that the time until the same mechanical crown amount is obtained is short, and the slow response speed means that the same time is long.

For example, in a rolling mill having a cross-rolling mechanism that can cross the roll axis and a roll-shift mechanism that can shift the roll in the axial direction, a cross-rolling mechanism in which the amount of change in the mechanical crown formed on the roll is fast is set up. A roll shift mechanism having a relatively slow change rate of the crown amount is used for controlling the sheet crown during steady rolling. By using the control means having a high response speed at the time of set-up, it is possible to quickly cope with the difference in the sheet crown between the steel strips, and it is possible to reduce the thickness deviation of the steel strip tip.

As described above, by using the control means having a high response speed at the time of set-up, when the steel strip having a different crown change of the base material is continuously rolled, it is possible to cope with the crown change near the welded portion of the steel strip. The control amount can be quickly corrected.

[0042]

As described above in detail, according to the cold rolling equipment and the method of rolling a steel strip of the present invention, a predetermined plate having a small edge drop with a low cost can be obtained over the entire length of the rolled steel strip. It is possible to manufacture a steel sheet having a thickness distribution, which greatly contributes to a reduction in manufacturing cost and an improvement in quality of the steel sheet.

[Brief description of the drawings]

FIG. 1 is a schematic view of a rolling facility of the present invention having a plate profile measuring device between a welding machine and a looper.

FIG. 2 is a schematic view of another rolling plant of the present invention having a plate profile measuring device between a steel strip take-out reel and a welding machine.

FIG. 3 is a schematic view of another rolling facility of the present invention for comparing a measured value obtained by a plate profile measuring device between a steel strip carrying reel and a welding machine with a measured value obtained by a plate thickness measuring device immediately before a rolling mill. is there.

FIG. 4 is a schematic diagram of another rolling facility of the present invention that performs control according to control characteristics of a control means.

[Explanation of symbols]

 1: Steel strip, 2: Welding machine, 3: Looper, 4: Plate thickness measuring device, 5: Rolling mill, 6: Steel strip carrying reel, 7: Plate profile measuring device, 8: Crown conversion device, 9: Rolling mill control Your computer, 10: control means characteristic comparison device, 11: control output operation device

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B21B 37/00 117B 117C (72) Inventor Manabu Manabu 4-33 Kitahama, Chuo-ku, Osaka-shi, Osaka Sumitomo Inside the Metal Industry Co., Ltd. (72) Inventor Yasunori Kakutani 4-5-33 Kitahama, Chuo-ku, Osaka-shi, Osaka Sumitomo Metal Industries Co., Ltd. F-term (reference) 4E024 AA03 AA07 DD02 DD03 DD09 EE01 FF01

Claims (6)

[Claims] 1. A cold rolling facility in which a steel strip take-out reel, a welding machine for connecting the steel strip, a looper for storing the steel strip, and a continuous cold rolling mill are sequentially arranged, wherein A plate profile measuring device provided between the looper and the steel strip to measure a thickness distribution in a width direction of the steel strip; a crown converting device for calculating a crown value of the plate based on a measured value by the plate profile measuring device; A cold rolling plant having a control output arithmetic unit for controlling one or more of a roll cross angle, a roll shift amount, a roll bender amount, and a roll crown amount of the rolling mill based on an output from the crown conversion device. 2. A steel sheet profile measuring apparatus for measuring the thickness distribution of a steel strip in the width direction is provided between a welding machine for connecting the steel strip and a looper for storing the steel strip. Cold rolling equipment. 3. The cooling device according to claim 1, wherein a plate profile measuring device for measuring the thickness distribution of the steel strip in the width direction is provided between the steel strip unloading reel and a welding machine connecting the steel strip. Rolling equipment. 4. The method according to claim 1, wherein the feed of the steel strip is stopped using the cold rolling equipment according to claim 1,
A cold rolling method for a steel strip, wherein the thickness distribution in the width direction of the steel strip is measured by a sheet profile measuring device for measuring the thickness distribution in the width direction of the steel strip. 5. In addition to measuring the thickness distribution in the width direction of the steel strip,
In addition, the steel strip crown of the steel strip is continuously measured, and a control means having a larger crown control range than the control means at the time of steady rolling is used at the time of setup, and a crown control range which is smaller than the control means at the time of setup at the time of steady rolling. 5. The method for cold rolling a steel strip according to claim 4, wherein the method comprises using means. 6. In addition to measuring the thickness distribution in the width direction of the steel strip,
Furthermore, the crown of the steel strip is continuously measured, and the control means having a faster crown control response speed than the control means at the time of steady rolling is used at the time of set-up. The cold rolling method for a steel strip according to claim 4, wherein a control means having a low speed is used.