JP4008835B2 - Metal strip rolling method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a metal strip rolling method for changing a running distance when continuously rolling a continuous metal strip to which a plurality of metal strips are connected.
[0002]
[Prior art]
Conventionally, in cold rolling of a metal strip, for example, a single metal strip wound in a coil shape is rewound, passed through a rolling stand, cold rolled, and then wound on a take-up reel. It was rolling. In rolling such a single metal band, the metal band is repeatedly mounted on a rewinding device and the rolling operation as described above is performed, or the metal band that has been rolled and wound is unwound in the reverse direction and rolled. Reverse type rolling was performed. Thereafter, a plurality of metal bands are connected by, for example, welding to form a continuous metal band, and the continuous metal band is passed through a so-called tandem rolling facility in which a plurality of rolling stands are arranged in the rolling direction. As a result, high efficiency was achieved by finishing multiple metal strips to the target thickness with a single pass.
[0003]
In addition, along with the performance improvement of various control systems, forming a continuous metal strip that connects different metal strips such as the type, rolling target plate thickness and rolling target plate width, and in the course of rolling this continuous metal strip, Change the running conditions to change the rolling conditions according to the type of metal strip that is the material to be rolled, the rolling target plate thickness, and the rolling target plate width. It has become possible to manufacture with the opportunity to pass the plate once.
[0004]
When rolling a continuous metal strip, the change point at which the rolling condition is changed in the setting of the running distance often changes the manufacturing specifications for each metal strip, and therefore often coincides with the connection between the metal strips. . Therefore, the prior art will be exemplified below with the connection part between the metal bands as a change point. In addition, a metal band that is currently rolled is referred to as a preceding metal band, and a metal band that is connected downstream of the preceding metal band in the rolling direction and is rolled following the preceding metal band is referred to as a trailing metal band.
[0005]
Rolling information relating to the rolling conditions determined for each metal band that is divided according to the change points is stored in advance in a memory of a process computer, for example. Hereinafter, this pre-stored rolling information is referred to as a preset value. In continuous rolling of a continuous metal strip, when the change point formed in the continuous metal strip reaches a predetermined position and the change point is detected by a sensor provided in the rolling equipment, the process computer responds to the detection output. Then, a setting change instruction signal is output so as to be a preset value to the shape control means for reading the preset value and setting the rolling conditions, and the shape control means is set to the preset value.
[0006]
The metal band that has started rolling with the shape control means set to the preset value becomes the preceding metal band, and the thickness, width, etc. of the sheet metal while the preceding metal band is being rolled, such as steepness, etc. The shape is detected by each sensor, the deviation between the detection output from each sensor and the control target value is obtained, and the control amount of the shape control means is feedback-controlled or manually operated so that this deviation approaches zero (0) Then, the preceding metal strip is rolled so as to have a predetermined size and shape. When the change point, which is the connecting portion between the preceding metal band and the subsequent metal band, reaches a predetermined position, a preset value corresponding to the subsequent metal band is read and the rolling control operation similar to the above is executed. . Each time such a change is detected, a preset value is read, and rolling operation control for setting rolling conditions based on the preset value is the same type and the same rolling target size / shape for the preceding metal band and the following metal band. Even so, it is executed without exception.
[0007]
FIG. 3 is a diagram for explaining a state of rolling operation control in a conventional change in running distance setting. In FIG. 3, when the preceding metal strip and the following metal strip are the same type of metal and the rolling target dimension and the rolling target shape are the same, the rolling setting is changed using the conventional preset value. The state of operation control is illustrated.
[0008]
The preceding metal strip 2 starts rolling based on the preset value, and then, for example, in response to the detection output from the sheet thickness detection sensor, the rolling position of the rolling roll and the rolling load are feedback-controlled to be in a stable state showing a constant value. Further, the amount of work roll bender is feedback controlled in response to the detection output from the shape detection roll 4 provided on the exit side of the rolling stand 3 of the rolling equipment 1, and after the preset value, the shape is passed through the stage I and the stage II. In the stage III where the deviation is small and close to the target shape, the stable state is reached, and the rolling is performed under the conditions indicating the stable state up to the rear end portion in the vicinity of the connecting portion with the subsequent metal band 5 of the preceding metal band 2.
[0009]
However, when the connecting portion between the preceding metal band 2 and the subsequent metal band 5 as the change point 6 reaches the rolling stand 3 at a predetermined position, the subsequent metal band 5 and the preceding metal band 2 are the same type of metal. Although the rolling target dimensions and shape are the same and the preceding metal strip 2 is rolled under stable rolling conditions close to the rolling target dimension and the rolling target shape, the rolling conditions are the following metal The setting is changed to a preset value that is predetermined and stored in accordance with the band 5.
[0010]
Therefore, in the rolling of the subsequent metal strip 5, the operation control process until the stable state is reached again in the rolling of the preceding metal strip 2 is repeated, so that the subsequent roll rolled in the time until the stable state is reached again. The size and shape of the metal strip 5 have a deviation from the target value. If this deviation is excessive, the dimensions and shape are out of specification and cannot be commercialized as poor quality, resulting in yield loss.
[0011]
The conventional technology that suppresses the yield loss at the tip of the subsequent rolled material in the change in the running distance has a shape in which the roll gap and the roll speed are set and changed in a short change time, and the long change time is required. The one-shape control device having the minimum required setting change time makes the setting change to correct the deterioration of the flatness of the material to be rolled by the control device, thereby shortening the setting change time of the roll gap and the roll speed, There is one that improves the yield by reducing the thickness deviation and shortening the range of the material to be rolled in which the shape defect occurs (see Patent Document 1).
[0012]
In another prior art, by reducing the belly stretch in the vicinity of the plate width change point of the wider plate width in the preceding plate or the following plate, the length of the defective shape section of the strip to be rolled is reduced. There are some which are shortened (see Patent Document 2).
[0013]
[Patent Document 1]
Japanese Patent Laid-Open No. 6-154821
[Patent Document 2]
JP-A-9-94606
[0014]
[Problems to be solved by the invention]
The prior art disclosed in Patent Document 1 and Patent Document 2 is basically based on the premise that the rolling condition of the succeeding metal strip is changed with respect to the rolling condition of the preceding metal strip, and until the desired rolling conditions are stabilized. By shortening this time, it is possible to suppress the occurrence of dimensional and shape defects that occur during the time required to stabilize the rolling conditions, thereby improving the yield. Therefore, even if the preceding metal band and the subsequent metal band are the same type of metal band and have the same rolling target dimensions and rolling target shape, the rolling conditions must be set at the start of rolling the subsequent metal band. Since the setting is changed, there is a problem that the time until the desired rolling conditions are stabilized cannot be zero, and some quality defects remain.
[0015]
The present invention has been made in view of such circumstances, and an object thereof is to provide a preceding metal band and a succeeding metal in rolling with a change in the running distance of a continuous metal band formed by connecting a plurality of metal bands. To provide a method for rolling a metal band that can reduce the occurrence of defects in size and shape when the band can be regarded as the same.
[0016]
[Means for Solving the Problems]
The present invention, when continuously rolling a continuous metal band to which a plurality of metal bands are connected, in the rolling method of the metal band to change the running distance,
The same group among the groups in which the preceding metal band that is rolled and the subsequent metal band that is connected downstream of the preceding metal band in the rolling direction and is rolled following the preceding metal band are classified according to a predetermined condition And whether it belongs to
Further, it is determined whether or not the rolling target plate thickness difference Δh between the preceding metal strip and the subsequent metal strip is equal to or less than a predetermined plate thickness difference reference value hs,
When the preceding metal strip and the subsequent metal strip belong to the same group, and the rolling target plate thickness difference Δh is equal to or less than the plate thickness difference reference value hs (Δh ≦ hs),
A rolling method for a metal strip, wherein rolling of the succeeding metal strip is started using the actual value of the rolling conditions used for the rolling control of the preceding metal strip as the rolling conditions for the succeeding metal strip.
[0017]
According to the present invention, the rolling of the preceding metal band is completed in the continuous rolling of the continuous metal band to which a plurality of metal bands are connected, and the change point that is the connecting portion between the preceding metal band and the subsequent metal band is a predetermined position. When the running distance setting is changed to roll the trailing metal strip after reaching the above, the leading metal strip and the trailing metal strip belong to the same group, and the rolling target plate thickness difference Δh is the plate thickness difference reference value hs. When the following is true (Δh ≦ hs), rolling of the succeeding metal strip is started using the actual value of the rolling condition used for the rolling control of the preceding metal strip as the rolling condition of the succeeding metal strip.
[0018]
Thus, when starting rolling of the succeeding metal strip that belongs to the same group and is regarded as identical to the preceding metal strip by Δh ≦ hs, the preset prepared as the rolling condition of the succeeding metal strip Since the rolling of the succeeding metal strip is started using the actual rolling condition value in a state where the preceding metal strip has been stably rolled to the rolling target size and the rolling target shape without using the value, the succeeding metal strip Can be built into the rolling target dimension and the rolling target shape from the start of rolling.
[0019]
That is, if the rolling condition is set to a preset value and the subsequent metal strip is started to be rolled, even in the subsequent metal strip that is considered to be the same as the preceding metal strip, the conditions for rolling to the rolling target dimension and the rolling target shape are Since the feedback control is performed and the rolling conditions in which the rolling target dimensions and the rolling target shape were stably built in the preceding metal band from the preset value are reached, the time from the preset value to the stable casting state is reached. The manufactured metal strip has a rolling dimension and a rolling shape that deviate from the target size and shape. However, as described above, by starting rolling of the succeeding metal strip using the actual rolling condition value of the preceding metal strip without using the preset value as described above, it is possible to prevent the occurrence of a defective portion that deviates from the target dimension and target shape. Is done. Therefore, it is possible to improve the quality yield in the rolling process.
[0020]
Further, the present invention further determines whether or not the rolling target plate width difference Δw between the preceding metal strip and the subsequent metal strip is equal to or less than a predetermined plate width difference reference value ws,
When the rolling target plate width difference Δw is equal to or less than the plate width difference reference value ws (Δw ≦ ws),
Rolling of the subsequent metal strip is started using the actual value of the rolling conditions used for the rolling control of the preceding metal strip as the rolling conditions of the subsequent metal strip.
[0021]
According to the present invention, the fact that the rolling target sheet width difference Δw is equal to or less than the sheet width difference reference value ws (Δw ≦ ws) is added as a determination condition that the preceding metal band and the subsequent metal band are regarded as the same. Then, rolling of the succeeding metal strip is started using the actual value of the rolling condition used for the rolling control of the preceding metal strip as the rolling condition of the succeeding metal strip. As a result, it is possible to determine the identity of the preceding metal band and the succeeding metal band with higher accuracy, so that the actual value of the rolling conditions that have been made to build the preceding metal band into the target dimensions and shape, The rolling conditions for building the trailing metal strip into the target dimensions and shape are matched with higher adaptability. Therefore, it becomes possible to build into the rolling target size and shape with higher accuracy from the start of rolling the subsequent metal strip.
[0022]
The present invention is characterized in that a ratio (K2 / K1) of a deformation resistance value K2 of the succeeding metal band to a deformation resistance value K1 of the preceding metal band is used as the predetermined condition.
[0023]
According to the present invention, the predetermined condition used as an index for determining whether or not the preceding metal band and the following metal band belong to the same group is the deformation resistance value K1 of the preceding metal band and the deformation of the following metal band. It is a ratio with the resistance value K2. The deformation resistance value of the metal strip is a mechanical property value related to the rolling load among the rolling conditions. By using the deformation resistance value as an index for attribute determination in the same group, the deformation resistance value is divided into the preceding metal strip and the subsequent metal strip. On the other hand, when rolling is performed by applying the same rolling conditions, the reproducibility that the preceding metal strip and the subsequent metal strip are rolled to the same size and shape can be further enhanced.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a diagram showing a simplified configuration of a cold rolling apparatus 10 that is preferably used in the practice of the present invention. The cold rolling apparatus 10 illustrated in the present embodiment is a so-called tandem type cold rolling facility provided with a plurality of rolling stands, and is used for cold rolling of a steel strip 11 which is a kind of metal strip.
[0025]
The cold rolling apparatus 10 includes a rewinding reel (not shown), a change point detector 13 that detects a change point 12 that is a connecting portion between the preceding steel strip 11a and the subsequent steel strip 11b, and first to fourth rolling. Stands 14, 15, 16, 17, a shape detection roll 18 provided on the exit side of the fourth rolling stand 17, a plate thickness detector 19 for detecting the plate thickness of the steel strip 11, and detecting the plate width of the steel strip A sheet width detector 20, a deflector roll 21 that controls the traveling direction of the steel strip 11 traveling in the apparatus, and a take-up reel that winds the rolled steel strip 11. Responding to a tension reel 22 for applying a rolling tension, a processing circuit 23 for outputting a rolling control instruction signal corresponding to a rolling condition applied to a steel strip to be rolled, and a control signal from the processing circuit 23, the first ~ 4th rolling stand 14, 15, 16, 1 And a shape control means 24 for performing operation control.
[0026]
The change point detector 13 optically detects, for example, a through hole formed in a connecting portion between the preceding steel strip 11a and the succeeding steel strip 11b, and gives a detection output to the processing circuit 23. In the present embodiment, the change point detector 13 also has an encoder function, and the processing circuit 23 is given the time when the change point detector 13 detects the change point and the travel distance of the steel strip 11. Thus, it is possible to detect the timing at which the change point 12 reaches each position of the cold rolling apparatus 10, for example, a rolling stand.
[0027]
Since the first to fourth rolling stands 14, 15, 16, and 17 have the same configuration, the configuration will be described using the fourth rolling stand 17 as a representative example. The fourth rolling stand 17 has a pair of work rolls 17a1 and 17a2, intermediate rolls 17b1 and 17b2, and backup rolls 17c1 and 17c2, respectively. These rolls are predetermined by a roll driving means 17d such as a roll reduction cylinder. It is moved to the reduction position.
[0028]
The shape detection roll 18 is provided with a load cell so that the load can be detected from a plurality of locations set in the width direction orthogonal to the traveling direction of the steel strip 11. The shape detection roll 18 detects a shape such as steepness based on the relative difference in the detected load in the width direction of the steel strip 11. The detection output from the shape detection roll 18 is given to the processing circuit 23. An X-ray thickness meter or a γ-ray thickness meter is used for the plate thickness detector 19, and a known optical detector is used for the plate width detector 20.
[0029]
The processing circuit 23 is realized by a process computer, for example, and includes a memory 25 and a determination unit 26. The memory 25 is a storage means composed of, for example, a ROM, a RAM, etc., and stores rolling information related to the steel strip to be rolled in advance. The rolling information relating to the steel strip to be rolled includes, for example, a steel type code representing the attributes of the steel strip, a deformation resistance value K, a rolling target plate thickness h, a rolling target plate width w, a target steepness, a rolling speed, a rolling load, a workpiece Roll vendor amount. This rolling information is input in advance for each steel strip to be rolled, stored in the memory 25, and becomes the aforementioned preset value. Considering a certain moment in the rolled state, the rolling information of the preceding steel strip 11a that is currently rolled and the subsequent steel strip 11b that is connected to the preceding steel strip 11a and rolled after the preceding steel strip 11a. In the sense that the information can be specified, the preceding steel strip information 27 and the trailing steel strip information 28 are shown in FIG. 1 from a lot of stored rolling information.
[0030]
When the processing circuit 23 outputs a signal for controlling the rolling operation of the cold rolling apparatus 10, the determination means 26 performs various calculations and determination operations and outputs the results. The judging means 26 judges whether the preceding steel strip 11a and the succeeding steel strip 11b can be regarded as the same. The determination means 26 first determines whether the preceding steel strip 11a and the succeeding steel strip 11b belong to the same group among groups classified according to a predetermined condition. In the present embodiment, the ratio (K2 / K1) of the deformation resistance value K2 of the subsequent steel strip 11b to the deformation resistance value K1 of the preceding steel strip 11a is used as a predetermined condition. For example, when the ratio (K2 / K1) is within a range of 0.90 to 1.10, the preceding steel strip 11a and the succeeding steel strip 11b are set to be determined to belong to the same group. .
[0031]
Further, in the determination means 26, the difference Δh (= h1−h2) between the rolling target plate thickness h1 of the preceding steel strip 11a and the rolling target plate thickness h2 of the succeeding steel strip 11b is equal to or less than a predetermined plate thickness difference reference value hs. It is determined whether or not. In the present embodiment, when the rolling target plate thickness h1 (= 0.1h1) of 0.1 × the preceding steel strip 11a is used as the plate thickness difference reference value hs, and the rolling target plate thickness difference Δh ≦ 0.1h1, It is determined that the preceding steel strip 11a and the succeeding steel strip 11b are the same with respect to the plate thickness. The plate thickness difference reference value hs is not limited to a value obtained by multiplying the rolling target plate thickness h1 of the preceding steel strip 11a by a predetermined magnification as described above. For example, hs = 0.05 mm or the like. Alternatively, a fixed value may be set.
[0032]
Further, in the determination means 26, the difference Δw (= w1−w2) between the rolling target plate width w1 of the preceding steel strip 11a and the rolling target plate width w2 of the succeeding steel strip 11b is equal to or less than a predetermined plate width difference reference value ws. It is determined whether or not. In the present embodiment, when 50 mm is used as the sheet width difference reference value ws and the rolling target sheet width difference Δw ≦ 50 mm, it is determined that the preceding steel strip 11a and the subsequent steel strip 11b are the same with respect to the sheet width. . Note that the plate width difference reference value ws is not limited to 50 mm, and other values may be used, and the plate width difference reference value ws is set to a predetermined roll target plate width w1 of the preceding steel strip 11a like the plate thickness reference value hs. A value obtained by multiplying the magnification may be used.
[0033]
The ratio of deformation resistance (K2 / K1) is in the range of 0.90 to 1.10, the rolling target plate thickness difference Δh ≦ 0.1h1, and the rolling target plate width difference Δw ≦ 50 mm. When it is determined, that is, when it is determined that the preceding steel strip 11a and the following steel strip 11b are the same, the processing circuit 23 responds to the output of the determination means 26 and the rear end portion of the preceding steel strip 11a. The rolling of the subsequent steel strip 11b is started under the same rolling conditions without changing the actual value of the rolling conditions used for the nearby rolling.
[0034]
On the other hand, when at least one of the deformation resistance ratio (K2 / K1), the rolling target plate thickness difference Δh, and the rolling target plate width difference Δw does not satisfy the above-described determination condition, that is, the preceding steel strip 11a and the subsequent steel strip. When it is determined that the change point 12 has not reached the same position, the processing circuit 23 responds to the output of the determination means 26 and corresponds to the succeeding steel strip 11b. Then, the preset value stored in advance in the memory 25 is read, and a rolling control instruction signal based on the preset value is output to the shape control means 24. The shape control means 24 responds to the signal from the processing circuit 23, executes the operation control of the rolling stand, and starts rolling the succeeding steel strip 11b according to the preset rolling conditions.
[0035]
In addition, after the rolling of the steel strip 11 is started, the determination unit 26 calculates a deviation between the detection output from the shape detection roll 18 and the plate thickness detector 19 and the target steepness and the target plate thickness read from the memory 25. Calculate and output the result. The processing circuit 23 responds to the output of the determination means 26, and controls the shape of the rolling control instruction signal so as to operate the rolling stand so that the deviation approaches 0 in accordance with the operation control program read from the ROM of the memory 25, for example. Output to the means 24. Thus, the processing circuit 23 performs feedback control based on the detection outputs from the shape detection roll 18 and the plate thickness detector 19 when the steel strip 11 is being rolled.
[0036]
FIG. 2 is a flowchart for explaining a rolling method using the cold rolling apparatus 10 shown in FIG. A rolling method according to an embodiment of the present invention will be described with reference to the flowchart of FIG.
[0037]
In step s0, the preceding steel strip 11a is rolled while receiving feedback control, and the trailing steel strip 11b is connected to the rear end of the preceding steel strip 11a. In step s1, whether or not the ratio of the deformation resistance value K2 of the succeeding steel strip 11b to the deformation resistance value K1 of the preceding steel strip 11a (= K2 / K1) is in the range of 0.90 to 1.10. Determined. When the determination result is affirmative, that is, when it is determined that the preceding steel strip 11a and the succeeding steel strip 11b belong to the same group, the process proceeds to step s2.
[0038]
In step s2, it is determined whether or not the rolling target plate thickness difference Δh is equal to or less than the rolling target plate thickness h1 of 0.1 × the preceding steel strip, which is the plate thickness difference reference value hs. When the determination result is affirmative, that is, when it is determined that the preceding steel strip 11a and the succeeding steel strip 11b are the same with respect to the plate thickness, the process proceeds to step s3. In step s3, it is determined whether or not the rolling target plate width difference Δw is 50 mm or less, which is the plate width difference reference value ws. When the determination result is affirmative, that is, when it is determined that the preceding steel strip 11a and the succeeding steel strip 11b are the same with respect to the plate width, the process proceeds to step s4.
[0039]
In step s4, it is judged by the processing circuit 23 whether or not the change point 12 which is the connecting portion between the preceding steel strip 11a and the succeeding steel strip 11b has reached a predetermined position, for example, the position of the first rolling stand 14. . When the determination result is affirmative and the change point 12 has reached the predetermined position, the process proceeds to step s5. When the determination result is negative and the change point 12 has not yet reached the predetermined position, step s4 is repeated. In step s5, as a result of the feedback control, the actual value of the rolling condition of the preceding steel strip 11a that realizes the rolling target size and shape and is in a stable rolling state is used as it is, and the rolling of the subsequent steel strip 11b is started. .
[0040]
When the determination results in the aforementioned steps s1, s2, and s3 are negative, that is, when it is determined that the preceding steel strip 11a and the following steel strip 11b are not the same, the process proceeds to step s6. In step s6, a preset value stored in advance in the memory 25 corresponding to the subsequent steel strip 11b is read. In step s7, it is determined whether or not the change point 12 has reached a predetermined position. When the determination result is affirmative and the change point 12 has reached the predetermined position, the process proceeds to step s8. When the determination result is negative and the change point 12 has not yet reached the predetermined position, step s7 is repeated.
[0041]
In step s8, in response to the determination result of the determination means 26, the processing circuit 23 outputs a rolling control instruction signal based on the preset value to the shape control means 24, and the rolling condition is set to the preset value. In step s9, rolling of the subsequent steel strip 11b is started according to the preset rolling conditions.
[0042]
After the rolling of the trailing steel strip 11b is started in step s5 or step s9, the process returns to step s1. At this time, although omitted in the flow, the replacement is performed with the succeeding steel strip as a new preceding steel strip and the steel strip connected to the new preceding steel strip as a new succeeding steel strip. In addition, when the succeeding steel strip is not connected after the new preceding steel strip, the series of rolling operations is completed.
[0043]
As described above, in the present embodiment, the deformation resistance value K of the steel strip is used to determine whether or not the preceding steel strip 11a and the following steel strip 11b belong to the same group. It will never be done. For example, X1 for weakly deoxidized steel, X2 for aluminum killed steel, X3 for titanium killed steel, and any one of the code numbers X1 to X3 of the steel types specified by the deoxidation form corresponding to the steel strip for each steel strip. In addition, the case where the code numbers of the preceding steel strip and the succeeding steel strip match may be determined as the same group. Also, instead of deoxidizing form, for example, a code number is defined for each type of symbol specified in Japanese Industrial Standard (JIS) G3101, and a corresponding code number is assigned to each steel strip. If the code numbers of the steel strips match, it may be determined that they belong to the same group.
[0044]
The metal strip is a cold-rolled steel strip, but is not limited to this, and may be a hot-rolled steel strip, and may be a metal other than the steel strip, such as a copper strip or an aluminum strip.
[0045]
【The invention's effect】
According to the present invention, when starting rolling of a succeeding metal strip that belongs to the same group and is considered to be the same as the preceding metal strip by satisfying the rolling target plate thickness difference Δh ≦ the plate thickness difference reference value hs, Without using preset values prepared as rolling conditions for the row metal strip, using the actual rolling condition values in the state where the preceding metal strip was stably rolled to the rolling target dimensions and rolling target shape, Since the strip rolling is started, the succeeding metal strip can be built in the rolling target dimension and the rolling target shape from the rolling start time. In this way, by starting rolling the succeeding metal strip using the actual rolling condition actual value of the preceding metal strip without using the preset value, it is possible to prevent the occurrence of a defective portion that deviates from the target dimension and the target shape. It becomes possible to improve the quality yield in the rolling process.
[0046]
Moreover, according to the present invention, as the determination condition that the rolling metal strip width difference Δw is equal to or less than the strip width difference reference value ws (Δw ≦ ws), the preceding metal strip and the following metal strip are regarded as the same. In addition, rolling of the succeeding metal strip is started using the actual value of the rolling condition used for the rolling control of the preceding metal strip as the rolling condition of the succeeding metal strip. As a result, it is possible to determine the identity of the preceding metal band and the succeeding metal band with higher accuracy, so that the actual value of the rolling conditions that have been made to build the preceding metal band into the target dimensions and shape, The rolling conditions for building the trailing metal strip into the target dimensions and shape are matched with higher adaptability. Therefore, it becomes possible to build into the rolling target size and shape with higher accuracy from the start of rolling the subsequent metal strip.
[0047]
Further, according to the present invention, the predetermined condition used as a determination index as to whether or not the preceding metal band and the following metal band belong to the same group is the deformation resistance value K1 of the preceding metal band and the following metal band. It is a ratio with the deformation resistance value K2. The deformation resistance value of the metal strip is a mechanical property value related to the rolling load among the rolling conditions. By using the deformation resistance value as an index for attribute determination in the same group, the deformation resistance value is divided into the preceding metal strip and the subsequent metal strip. On the other hand, when rolling is performed by applying the same rolling conditions, the reproducibility that the preceding metal strip and the subsequent metal strip are rolled to the same size and shape can be further enhanced.
[Brief description of the drawings]
FIG. 1 is a diagram showing a simplified configuration of a cold rolling apparatus 10 that is preferably used in the practice of the present invention.
FIG. 2 is a flowchart for explaining a rolling method using the cold rolling apparatus 10 shown in FIG.
FIG. 3 is a diagram illustrating a state of rolling control in a conventional change in running setting.
[Explanation of symbols]
10 Cold rolling equipment
11 Steel strip
12 Changes
13 Changed point detector
14, 15, 16, 17 Rolling stand
18 Shape detection roll
19 Thickness detector
20 Plate width detector
23 Processing circuit
24 Shape control means
25 memory
26 judgment means

Claims (3)

When continuously rolling a continuous metal band to which a plurality of metal bands are connected, in the rolling method of the metal band for changing the running distance,
The same group among the groups in which the preceding metal band that is rolled and the subsequent metal band that is connected downstream of the preceding metal band in the rolling direction and is rolled following the preceding metal band are classified according to a predetermined condition And whether it belongs to
Further, it is determined whether or not the rolling target plate thickness difference Δh between the preceding metal strip and the subsequent metal strip is equal to or less than a predetermined plate thickness difference reference value hs,
When the preceding metal strip and the subsequent metal strip belong to the same group, and the rolling target plate thickness difference Δh is equal to or less than the plate thickness difference reference value hs (Δh ≦ hs),
A rolling method for a metal strip, wherein rolling of the succeeding metal strip is started using the actual value of the rolling conditions used for the rolling control of the preceding metal strip as the rolling conditions for the succeeding metal strip. Furthermore, it is determined whether the rolling target plate width difference Δw between the preceding metal strip and the subsequent metal strip is equal to or less than a predetermined plate width difference reference value ws,
When the rolling target plate width difference Δw is equal to or less than the plate width difference reference value ws (Δw ≦ ws),
The rolling of the metal strip according to claim 1, wherein the rolling of the succeeding metal strip is started by using the actual value of the rolling condition used for the rolling control of the preceding metal strip as the rolling condition of the succeeding metal strip. Method. The predetermined condition includes:
The method of rolling a metal strip according to claim 1 or 2, wherein a ratio (K2 / K1) of the deformation resistance value K2 of the succeeding metal strip to the deformation resistance value K1 of the preceding metal strip is used.

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