Plate width control device for reversible rolling mill

Abstract

The present invention relates to a strip width control device applied to a reversing mill, the reversing mill being provided with a edger mill having a pair of edger rolls that performs width rolling on a rolled material, and a horizontal mill disposed downstream of the edger mill, having a pair of horizontal rolls that performs horizontal rolling on the rolled material. The strip width control device of the present invention is provided with a reduction control device, a reduction position detector, a tracking device, and a strip width actual value calculation device. The reduction control device is configured to operate the edger mill in a manner that the pair of edger rolls contacts the rolled material in a reverse pass rolling. The reduction position detector is configured to detect a reduction position of the edger mill when the pair of edger rolls contacts the rolled material in the reverse pass rolling. The tracking device is configured to track a position in a length direction of the rolled material in the reverse pass rolling. The strip width actual value calculation device is configured to calculate strip width actual values of a plurality of positions in the length direction of the rolled material based on an output of the reduction position detector and an output of the tracking device.

Description

Technical Field

[0001] This invention relates to a plate width control device for a reversible rolling mill. Background Technology

[0002] In a hot rolling line, the rolled material is processed into product dimensions through roughing and finishing processes. The roughing process is performed using a reversible rolling mill equipped with a horizontal mill and an edge mill. The edge mill is located upstream of the horizontal mill. The edge mill has a pair of edge rolls for width rolling of the rolled material. The horizontal mill has a pair of horizontal rolls for horizontal rolling of the rolled material. In the roughing process, forward passes that direct the rolled material in the forward direction and reverse passes that direct the rolled material in the reverse direction are performed alternately and repeatedly. In the roughing process, while repeatedly performing forward and reverse passes, width rolling based on the edge rolls and horizontal rolling based on the horizontal rolls are repeatedly performed, and the rolled material is processed into a sheet width suitable for the start of finishing rolling. Prior art related to reversible rolling mills includes, for example, Patent Document 1 and Patent Document 2.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 58-070910

[0006] Patent Document 2: International Publication No. 2016 / 185583 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] The plate width can be limited in the finishing rolling process, therefore it is necessary to establish the plate width during the roughing rolling process. For this purpose, the plate width of the rolled material needs to be obtained along its entire length during roughing. In particular, in order to finish the plate width in the final forward rolling pass, the plate width needs to be obtained from the reverse rolling pass to the final forward rolling pass.

[0009] However, width gauges capable of measuring the width of rolled material are usually located in hot rolling lines at a position far from the inlet side of the reversible mill. To measure the width of the rolled material along its entire length using this width gauge, the rolled material must be conveyed to the gauge's location after exiting the edging mill, resulting in a time loss. Depending on the location of the width gauge on the inlet side, sometimes the rolled material reaches the gauge during the reverse pass rolling. However, to improve productivity, the rolling operation is quickly reversed after the rolled material exits the edging mill to begin the forward pass rolling. Therefore, the measurable width is limited to a portion of the rear end of the rolled material, and it is impossible to measure the width along its entire length.

[0010] One object of the present invention is to provide a plate width control device for a reversible rolling mill that can avoid a decrease in productivity due to time loss and can obtain the plate width of the rolled material along the entire length.

[0011] Methods for solving problems

[0012] The plate width control device of the present invention is applied to a reversible rolling mill, which includes: an edge rolling mill having a pair of edge rolling rolls for width rolling of the workpiece; and a horizontal rolling mill disposed downstream of the edge rolling mill having a pair of horizontal rolling rolls for horizontal rolling of the workpiece. The plate width control device of the present invention includes a reduction control device, a reduction position detector, a tracking device, and a plate width actual value calculation device. The reduction control device is configured to operate the edge rolling mill in a manner such that the pair of edge rolling rolls contact the workpiece during a reverse pass rolling. The reduction position detector is configured to detect the reduction position of the edge rolling mill when the pair of edge rolling rolls contact the workpiece during a reverse pass rolling. The tracking device is configured to track the position of the workpiece in the length direction during a reverse pass rolling. Then, the plate width actual value calculation device is configured to calculate the actual plate width value at multiple positions in the length direction of the workpiece based on the output of the reduction position detector and the output of the tracking device.

[0013] In the plate width control device of the present invention, the reduction control device may also be configured to apply constant load control to the edging mill during reverse rolling to maintain the contact between a pair of edging rolls and the rolled material. Alternatively, the reduction control device may be configured to repeatedly perform the following processes during reverse rolling: The first process is to operate the edging mill by reducing the distance between the pair of edging rolls, starting from a state where the pair of edging rolls are not in contact with the rolled material. The second process is to detect the contact between the pair of edging rolls and the rolled material based on the load measurement value of the edging mill. Then, the third process is to operate the edging mill by increasing the distance between the pair of edging rolls if contact between the pair of edging rolls and the rolled material is detected.

[0014] The plate width control device of the present invention may further include a plate width meter disposed downstream of the edging mill and configured to measure the plate width of the rolled material. In this case, the actual plate width calculation device may also be configured to correct the actual plate width value using the measured value of the plate width meter and the plate width predicted by the width expansion generated by horizontal rolling. Alternatively, the plate width control device of the present invention may further include a plate width meter disposed upstream of the edging mill and configured to measure the plate width of the rolled material. In this case, the actual plate width calculation device may also be configured to correct the actual plate width value using the measured value of the plate width meter.

[0015] The plate width control device of the present invention may further include a pressing position correction calculation device. The pressing position correction calculation device may also be configured to calculate the correction amount of the pressing position of the edging mill in the next forward rolling pass after the reverse rolling pass, based on the actual plate width value. More specifically, the correction amount of the pressing position may be calculated for each position in the length direction in accordance with the distribution of the actual plate width value in the length direction, or the correction amount of the pressing position as a whole in the length direction may be calculated based on the average value of the actual plate width value in the length direction.

[0016] The effects of the invention

[0017] According to the plate width control device of the present invention, the actual plate width values ​​at multiple positions along the length of the rolled material are calculated based on the pressing position of the edging mill when the edging roll contacts the rolled material during the reverse rolling process, and the position of the rolled material along its length direction tracked during the reverse rolling process. Accordingly, it is not necessary to transport the rolled material beyond the distance required for the reverse rolling process, thus avoiding a decrease in productivity due to time loss, and enabling the plate width of the rolled material to be obtained along its entire length. Attached Figure Description

[0018] Figure 1 The diagram illustrates the configuration of the plate width control device according to the first embodiment of the present invention, the reversible rolling mill using the plate width control device, and the processing during reverse rolling performed by the plate width control device.

[0019] Figure 2 This diagram illustrates the operation of the edge rolling rolls in the reverse rolling process according to the first embodiment of the present invention.

[0020] Figure 3 The diagram illustrates the configuration of the plate width control device according to the first embodiment of the present invention and the reversible rolling mill using the plate width control device, as well as the processing during the forward rolling operation performed by the plate width control device.

[0021] Figure 4 This diagram illustrates the configuration of a first modified example of the plate width control device according to the first embodiment of the present invention, and the processing during reverse rolling performed by the plate width control device.

[0022] Figure 5 This diagram illustrates the configuration of a second variation of the plate width control device according to the first embodiment of the present invention, and the processing during reverse rolling performed by the plate width control device.

[0023] Figure 6 This is a diagram illustrating the operation of the edge rolling rolls in the reverse pass rolling of the second embodiment of the present invention. Detailed Implementation

[0024] 1. First Implementation Method

[0025] 1-1. Composition of a reversible rolling mill

[0026] The following is for reference Figure 1 The configuration of the reversible rolling mill 10 according to the first embodiment of the present invention will be described.

[0027] The reversible rolling mill 10 includes a roller table 80 for conveying the rolled material (slab) 90. The roller table 80 has multiple rollers capable of being driven in both the forward and reverse directions. A speed detector 81 is installed on the roller table 80 to detect its conveying speed. The reversible rolling mill 10 includes an edge rolling mill 20 for width rolling and a horizontal rolling mill 30 for horizontal rolling on the conveying line of the rolled material 90 via the roller table 80. The horizontal rolling mill 30 is positioned downstream of the edge rolling mill 20 on the conveying line.

[0028] The edging mill 20 includes a pair of edging rolls 25 arranged to clamp the workpiece 90 from the left and right. The edging rolls 25 are supported by roll bearing housings 26, i.e., a shaft box equipped with bearings. The edging mill 20 includes a pressing device 22 that moves the edging rolls 25 supported by the roll bearing housings 26 in the width direction of the workpiece 90. The pressing device 22 includes a hydraulic cylinder, enabling high-speed pressing action.

[0029] The edging mill 20 includes a load cell 24 for detecting the rolling load of the pressing device 22. Specifically, the load cell 24 is a force sensor installed in the roll bearing housing 26. Alternatively, a hydraulic detector installed in the hydraulic cylinder of the pressing device 22 can also be used as the load cell 24. Furthermore, the edging mill 20 includes a pressing position detector 23 for detecting the pressing position of the pressing device 22. The pressing position detector 23 outputs the length of the hydraulic column in the hydraulic cylinder as the detected value of the pressing position. Here, the pressing position represents the value of the gap between the pair of edging rolls 25 when there is no load (not during rolling). The pressing position detector 23 calculates and outputs the pressing position based on the measured values ​​of the lengths of the hydraulic columns in the hydraulic cylinders on both sides. For example, the gap of the actual edge rolling roll 25 is measured in advance at a certain reference liquid column length (this process is called zeroing), and the value obtained by subtracting the change in liquid column length relative to the zeroing time from the measured value (roller gap at zeroing time) is used as the detection value of the pressing position.

[0030] The horizontal rolling mill 30 includes a pair of horizontal rolls 31 arranged to clamp the rolled material 90 from above and below. A speed detector 32 is mounted on each horizontal roll 31 to detect its rotational speed. Additionally, a hot strip detector (HMD) 100 is located on the exit side of the horizontal rolling mill 30. However, the hot strip detector 100 located on the reversible rolling mill 10 is not the only one; multiple hot strip detectors 100 are located at various points along the conveyor line of the rolled material 90.

[0031] 1-2. Composition of the plate width control device

[0032] Next, continue to refer to Figure 1 The configuration of the plate width control device 200 used in the reversible rolling mill 10 configured as described above will be explained.

[0033] The board width control device 200 comprises a pressing control device 21, a board width actual calculation device 40, a setting calculation device 50, a pressing position correction calculation device 60, and a tracking device 70. These devices 21, 40, 50, 60, and 70 constituting the board width control device 200 can be application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), central processing units (CPUs), or other processing devices. One or more of devices 21, 40, 50, 60, and 70 can also be a combination of two or more ASICs, FPGAs, CPUs, or other processing devices. The ASICs, FPGAs, CPUs, and other processing devices constituting the board width control device 200 include a series of executable commands. When these commands are executed, the corresponding ASICs, FPGAs, CPUs, and other processing devices are triggered to perform the functions of the devices 21, 40, 50, 60, and 70 described later.

[0034] The setting calculation device 50 is configured to assign various setting calculation values ​​51 to the pressing control device 21. The setting calculation values ​​51 include a target value 51a for the width of the rolled material 90. The target load value 51a is a value predetermined within the range of minimum load to maximum load. The minimum load is the lower limit of the load that can be stably measured, and the maximum load is the mechanically permissible upper limit of the edging mill 20.

[0035] The roll reduction control device 21 operates based on various preset calculation values ​​51 assigned by the setting calculation device 50. Additionally, the rolling load detected by the load gauge 24 and the roll reduction position detected by the roll reduction position detector 23 are input to the roll reduction control device 21. The roll reduction control device 21 is configured to send the detected value of the roll reduction position input by the roll reduction position detector 23 during the reverse rolling pass as the actual roll reduction position value 21a to the actual plate width calculation device 40.

[0036] The tracking device 70 acquires the rotational speed of the horizontal roll 31 detected by the speed detector 32, the conveying speed of the roller table 80 detected by the speed detector 81, and the output of the hot-rolled strip detector 100. The tracking device 70 is configured to use this information acquired during the reverse rolling pass to generate tracking information 71 indicating the position of the rolled material 90 in the length direction. The generated tracking information 71 is sent to the actual plate width calculation device 40.

[0037] The actual plate width calculation device 40 includes a storage device 41 and an actual plate width calculation unit 42. The actual pressing position value 21a sent from the pressing control device 21 is stored in the storage device 41. In addition, the tracking information 71 generated by the tracking device 70 is also stored in the storage device 41. Both the actual pressing position value 21a and the tracking information 71 are information obtained during the reverse rolling of the rolled material 90, and are correlated with each other through the timing of acquisition. The timing of acquisition of this information is predetermined based on a fixed or variable sampling time interval, or the position of the rolled material 90 in the length direction.

[0038] The total length plate width actual calculation unit 42 is configured to calculate the actual value of the plate width of the rolled material 90 at multiple positions along the length direction based on the information stored in the storage device 41. Details regarding the calculation method for the actual plate width will be described later. The actual plate width value calculated by the total length plate width actual calculation unit 42 is input to the pressing position correction calculation device.

[0039] The pressing position correction calculation device 60 is configured to calculate the correction amount for the pressing position of the pressing device 22 based on the actual value of the plate width calculated by the total plate width calculation unit 42. The correction amount for the pressing position calculated by the pressing position correction calculation device 60 is used by the pressing control device 21 to control the edge rolling mill 20 in the next forward rolling pass after the reverse rolling pass where the actual plate width value is calculated. Details regarding the calculation method for the pressing position correction amount will be described later.

[0040] 1-3. Handling of reverse rolling in plate width control device

[0041] In the reverse pass rolling, the workpiece 90 is conveyed from the roller table 80 in the direction of the arrow, during which a pair of edge rolling rolls 25 clamp the workpiece 90 from the left and right. In the reverse pass rolling, the edge rolling mill 20 is subjected to constant load control via the pressing control device 21. In constant load control, the pressing device 22 is operated such that the rolling load detected by the load gauge 24 matches the target load value 51a.

[0042] Figure 2 This diagram illustrates the movement of the edge rolls 25 during reverse rolling. By maintaining a constant load, the gap 28 between the edge rolls 25 is controlled so that the edge rolls 25 maintain contact with the workpiece 90 along its entire length. Then, during the relative movement of the edge rolls 25 along the side of the workpiece 90, the actual value 21a of the pressing position corresponding to the width direction position of the edge rolls 25 is obtained by the pressing position detector 23.

[0043] After the reverse rolling pass is completed, the actual width calculation device 40 calculates the actual width value of the rolled material 90. The calculation of the actual width value is performed by the total length actual width calculation unit 42. The total length actual width calculation unit 42 uses the actual value 21a of the pressing position stored in the storage device 41 to calculate the actual width value of the entire length of the plate using the following formula.

[0044]

Number 1

[0045]

[0046] The meanings of the parameters in the above formula are as follows.

[0047]

Number 2

[0048] The actual width of the plate at position j in the longitudinal direction (reverse pass i-1) [mm]

[0049]

Number 3

[0050] Actual value of the pressing position at position j in the length direction (reverse pass i-1) [mm]

[0051]

Number 4

[0052] ΔS mEi-1 Edge mill elongation in the reverse pass (i-1 pass) [mm]

[0053]

Number 5

[0054] ΔS weari-1 Wear of the edge rolling rolls in the reverse pass (i-1 pass) [mm]

[0055]

Number 6

[0056] ΔS thermi-1 Thermal expansion of the edge rolls in the reverse pass (i-1 pass) [mm]

[0057] The elongation of the edge rolling mill is calculated using a mill curve expressed as a quadratic equation, based on the rolling load. The wear and thermal expansion of the edge rolling rolls are considered as changes in the roll diameter relative to zeroing. The wear is calculated and accumulated periodically over several seconds based on predicted or measured rolling loads and rolling lengths. The thermal expansion is calculated and accumulated periodically over several seconds based on predicted or measured roll temperatures. The wear becomes positive during edge rolling roll wear, and the thermal expansion becomes positive during thermal expansion.

[0058] In this embodiment, during reverse rolling, the contact between the edge roll 25 and the rolled material 90 is maintained by constant load control. Therefore, the actual value of the pressing position 21a can be obtained at any position along the length. For obtaining the actual value of the plate width over the entire length with high accuracy, the more measurement points used to obtain the actual value of the pressing position 21a and the tracking information 71, the more preferred.

[0059] Furthermore, in this embodiment, the target load value 51a for constant load control is set to a sufficiently small value within a range where the load can be stably measured. This allows the width reduction during the reverse rolling pass to be kept small enough to negligible the formation of bone in the rolled material 90 and the width variation (plastic deformation) caused by its width return. As a result, the actual width of the entire length of the plate, especially the front and rear ends, can be obtained with high accuracy.

[0060] As explained above, in this embodiment, the actual width of the rolled material 90 along its entire length is calculated based on the pressing position of the edging mill 20 obtained through constant load control during the reverse rolling process, and the position of the rolled material 90 along its length tracked during the reverse rolling process. Therefore, it is not necessary to transport the rolled material 90 more than the distance required for the reverse rolling process. Thus, the width control device 200 according to this embodiment can avoid productivity reduction due to time loss and can obtain the width of the rolled material 90 along its entire length.

[0061] 1-4. Handling during the positive pass rolling of the plate width control device

[0062] Then, reverse rolling is performed in the forward rolling process. Figure 3 This indicates the processing during the main rolling pass by the plate width control device 200. During the main rolling pass, the workpiece 90 is conveyed by the roller table 80 in the direction of the arrow, and is rolled from left to right by the edge rolling mill 20. The edge rolling mill 20 rolls the workpiece 90 in a manner that the plate width at the end of the main rolling pass covers the entire length.

[0063] Before the start of the forward rolling pass, the correction amount for the pressing position of the edge rolling mill 20 is calculated by the pressing position correction calculation device 60. The pressing position correction amount is calculated using the actual value of the full-length plate width calculated during the reverse rolling pass. Alternatively, the pressing position correction amount can be calculated for each position along the length direction, matching the distribution of the actual plate width values ​​along the length direction, or it can be calculated as a whole along the length direction based on the average value of the actual plate width values ​​along the length direction. The following formula is an example of a formula for calculating the pressing position correction amount.

[0064]

Number 7

[0065]

[0066]

Number 8

[0067]

[0068]

Number 9

[0069]

[0070] The meanings of the parameters in the above formula are as follows.

[0071]

Number 10

[0072] ΔS i (j): Correction amount for the pressing position of the edge rolling mill at position j in the length direction, for pass i [mm]

[0073]

Number 11

[0074] ΔB i-1 (j): Deviation of pass i-1 at position j in the length direction relative to the reference width [mm]

[0075]

Number 12

[0076] η i The rolling mill reduction efficiency for the i-th pass [-]

[0077]

Number 13

[0078] G i : i-th pass's pressure position correction gain [-]

[0079]

Number 14

[0080] The actual width of the plate at position j in the longitudinal direction (reverse pass i-1) [mm]

[0081]

Number 15

[0082] Reference value for plate width [mm] for the reverse pass (i-1 pass)

[0083]

Number 16

[0084] L start : Starting position of the average interval [m]

[0085]

Number 17

[0086] L end : End position of the average interval [m]

[0087] The rolling mill's reduction efficiency is expressed as a function of the thickness-to-width ratio, typically around 0.2 to 0.8. The baseline width value for the reverse pass (i-1 pass) uses the average of the actual width values ​​within a specified range. However, a calculated width setting can be used instead of the average.

[0088] The pressing position correction calculation device 60 inputs the pressing position correction amount 61 of the edging mill, calculated according to the above formula, to the pressing control device 21. The pressing position correction amount 61 of the edging mill is calculated according to each position in the length direction, matching the distribution of the actual value of the plate width in the length direction. In addition, the setting calculation device 50 inputs the load target value 51a to the pressing control device 21. The pressing control device 21 controls the gap between the edging rolls 25 to match the timing between these input information and the tracking information 71 input from the tracking device 70. As a result, the width accuracy of the rolled material 90 fed to the downstream finishing rolling process is improved, and the product yield is improved.

[0089] 1-5. The configuration of the first modified example of the plate width control device and the correction process for the actual plate width value

[0090] Figure 4 This describes a first variation of the plate width control device 200. In this first variation, the plate width control device 200 includes a plate width meter 110 located downstream of the reversible rolling mill 10. Furthermore, the actual plate width calculation unit 40 of the plate width control device 200 comprises a storage device 41, a total length plate width calculation unit 42, and a plate width correction unit 43.

[0091] In the first variation, during the forward rolling before the reverse rolling, the rolled material 90, having passed through the horizontal mill 30, reaches the plate width meter 110, where its width is measured. However, after confirming that the rear end of the rolled material 90 (the rear end in the direction of travel of the rolling line) has passed through the horizontal mill 30, the conveying direction of the roller table 80 is rapidly switched from the forward to the reverse. Therefore, instead of measuring the entire length of the rolled material 90, only the width of a portion 91 of the front end of the rolled material 90 that reaches the plate width meter 110 before the rear end of the rolled material 90 passes through the horizontal mill 30 is measured. The plate width measurement value 111 obtained by the plate width meter 110 is sent to the plate width actual calculation device 40 and stored in the storage device 41.

[0092] In the first modified example, the actual plate width correction unit 43 corrects the actual plate width value of the entire length obtained by the actual plate width calculation unit 42. The correction amount of the actual plate width value is calculated using the plate width measurement value obtained by the plate width gauge 110 during the main rolling pass, by the following formula.

[0093]

Number 18

[0094]

[0095]

Number 19

[0096]

[0097]

Number 20

[0098]

[0099]

Number 21

[0100] j′=j·λ i-1

[0101]

Number 22

[0102]

[0103] The meanings of the parameters in the above formula are as follows.

[0104]

Number 23

[0105] The actual width of the reverse pass (i-1 pass) at position j along the length direction after correction [mm].

[0106]

Number 24

[0107] Correction amount for actual plate width [mm]

[0108]

Number 25

[0109] Begin calculating the length direction position [m] of the rolled material for the correction amount.

[0110]

Number 26

[0111] The length-direction position [m] of the starting point of the interval capable of measuring the width of the plate.

[0112]

[0113]

Number 27

[0114] The lengthwise position of the rolled material at the end of the correction calculation [m]

[0115]

Number 28

[0116] The length-direction position [m] of the end point of the interval capable of measuring the width of the plate.

[0117]

[0118]

Number 29

[0119] The predicted plate width [mm] after the reverse pass is based on the plate width measurement at position j along the length direction.

[0120]

Number 30

[0121] The measured value [m] of the plate width at position j along the length direction on the mill exit side of the first pass (i-2 passes).

[0122] Where j satisfies the following conditions.

[0123]

Number 31

[0124]

[0125]

Number 32

[0126] Predicted width extension [mm] caused by horizontal rolling in the reverse pass (i-1 pass).

[0127]

Number 33

[0128] j′: Considering the position of the length extension caused by horizontal rolling in the reverse pass (i-1 pass) [mm]

[0129]

Number 34

[0130] λ i-1 : The elongation in the length direction produced by horizontal rolling in the reverse pass (i-1 pass) [m]

[0131]

Number 35

[0132] h i-2 Side plate thickness for the first pass (i-2 passes) [mm]

[0133]

Number 36

[0134] h i-1 Side plate thickness of the reverse pass (i-2 pass) [mm]

[0135] Generally, the plate width gauge 110 downstream of the reversible rolling mill 10 is located at a position approximately 5 meters or more away from the reversible rolling mill 10 to avoid measurement interference caused by factors such as roll cooling water. In cases where a reverse pass is performed after a forward pass, the process quickly switches to reverse pass rolling after the forward pass is completed. Therefore, an unmeasurable interval (equivalent to the distance from the horizontal rolling mill 30 to the plate width gauge 110) is generated in the plate width gauge 110 downstream of the reversible rolling mill 10. The actual plate width correction amount can be calculated in any interval within the interval where the plate width measurement value can be determined.

[0136] 1-6. The second variation of the plate width control device and the correction process for the actual plate width value

[0137] Figure 5 This represents a second variation of the plate width control device 200. In this second variation, the plate width control device 200 includes a plate width meter 110 located upstream of the reversible rolling mill 10. Furthermore, the plate width actual calculation unit 40 of the plate width control device 200 comprises a storage device 41, a total length plate width actual calculation unit 42, and a plate width actual correction unit 43.

[0138] In the second variation, during the reverse rolling pass, the rolled material 90, having passed through the edge mill 20, reaches the plate width meter 110, where its width is measured. However, after confirming that the front end of the rolled material 90 (the front end in the direction of travel of the rolling line) has passed through the horizontal mill 30, the conveying direction of the roller table 80 is rapidly switched from the reverse pass to the forward pass. Therefore, instead of measuring the width along the entire length of the rolled material 90, only the width of the portion 92 at the rear end of the rolled material 90 before its front end passes through the edge mill 20 and reaches the plate width meter 110 is measured. The plate width measurement value 111 obtained by the plate width meter 110 is sent to the plate width actual calculation device 40 and stored in the storage device 41.

[0139] In the second variation, the actual plate width correction unit 43 corrects the actual plate width value of the entire length obtained by the actual plate width calculation unit 42. The correction amount of the actual plate width value is calculated using the plate width measurement value obtained by the plate width gauge 110 during the reverse rolling process, according to the following formula.

[0140]

Number 37

[0141]

[0142]

Number 38

[0143]

[0144] The meanings of the parameters in the above formulas are as follows. Parameters shared with those in the first variation are omitted from the explanation.

[0145]

Number 39

[0146] The measured value [mm] of the plate width at position j along the length direction on the mill exit side of the first pass (i-2 passes).

[0147] Generally, the plate width gauge 110 upstream of the reversible rolling mill 10 is located near the exit side of the upstream mill. After the reverse pass rolling, the mill quickly switches to the forward pass rolling, thus creating an unmeasurable interval in the plate width gauge 110 upstream of the reversible rolling mill 10 (equivalent to the distance from the plate width gauge 110 to the edge mill 20). The actual plate width correction amount can be calculated in any interval within the interval where the plate width measurement value can be determined.

[0148] In rolling mills, zeroing is performed whenever rolls are changed or the equipment is stopped to improve dimensional accuracy by correcting for changes in mechanical wear and roll diameter over time. Horizontal rolling mills 30 can perform zeroing by bringing the rolls into contact (roll contact), thus allowing zeroing under conditions close to actual rolling loads. On the other hand, a pair of edge rolls 25 are separated, making zeroing by bringing the rolls into contact impossible. Therefore, conventional methods have involved indirectly measuring the edge roll gap, such as measuring the gap of edge rolls in a stopped state or measuring by clamping a test piece of known size. However, indirect methods introduce measurement errors, sometimes making it impossible to accurately zero the edge roll gap.

[0149] In this regard, the aforementioned plate width control device can correct errors in the edge rolling roll gap caused by inaccurate zeroing and prediction errors due to roll wear, thereby obtaining a high-precision actual plate width value and improving the width rolling accuracy.

[0150] 2. Second Implementation Method

[0151] Next, the board width control device according to the second embodiment of the present invention will be described. The basic structure of the board width control device in this embodiment is the same as that in the first embodiment. That is, the board width control device in this embodiment has the same features as in the first embodiment. Figure 1 The configuration is shown. The difference between the plate width control device of this embodiment and the plate width control device of the first embodiment lies in the control of the edge rolling mill 20 by the pressing control device 21, which operates during the reverse rolling pass. Specifically, the operation of the edge rolling roll 25 controlled by the pressing control device 21 is different.

[0152] Figure 6 This diagram illustrates the operation of the edge roll 25 during the reverse pass rolling in this embodiment. Figure 6 The dashed line represents the movement relative to the edging roll 25 of the rolled material 90, i.e., the movement of the edging mill 20 at its pressing position. In the second embodiment, multiple measuring points are predetermined along the length of the rolled material 90, and the actual width of the plate is obtained at each measuring point. Figure 6In the example shown, the point where the moving line contacts the rolled material 90 is the measurement point for obtaining the actual value of the plate width. The measurement point is determined based on a fixed or variable sampling time interval and length interval.

[0153] The pressing position of the edge rolling mill 20 before the start of the reverse rolling process is such that the edge rolling roll 25 does not contact the rolled material 90. Then, based on the tracking information 71, the position of the predetermined measuring point of the rolled material 90 reaching the edge rolling roll 25 is detected (time t0).

[0154] Next, the edging mill 20 is operated in the direction of narrowing the gap 28 between the edging rolls 25 (Action 1). At this time, the pressing speed of the edging mill 20 is predetermined before the start of the reverse rolling pass, taking into account the response characteristics of the pressing device 22 and the load cell 24, as well as the control cycle of the pressing control device 21. Specifically, the pressing speed of the edging mill 20 is either a constant speed or a speed determined according to the pressing position.

[0155] In controlling the reduction speed, the rolling load and the change in rolling load per unit time are monitored. Then, when the edging roll 25 contacts the workpiece 90 and the rolling load reaches the target load value (time t1), the reduction position of the edging mill 20 and the longitudinal position of the workpiece 90 at that moment are stored in the storage device 41. In addition, the target load value is a predetermined value that allows for stable load measurement and that the width reduction or dogbone protrusion does not exceed the upper limit of the allowable range.

[0156] Then, the edge mill 20 is operated in such a way that the gap 28 between the edge rolling rolls 25 is expanded by a predetermined distance (Action 2). Then, the edge rolling rolls 25 are kept in standby while maintaining the gap 28 until the next measuring point of the pre-determined rolled material 90 reaches the position of the edge rolling rolls 25 (Action 3).

[0157] In the first embodiment, the hydraulic cylinder of the pressing device 22 is opened or closed by performing constant load control, and the direction of sliding friction of the hydraulic cylinder changes each time. When a hydraulic detector is used as a load cell 24, the change in the direction of sliding friction becomes a disturbance in the constant load control, deteriorating the controllability of the constant load control. Therefore, in the first embodiment, it may not be possible to maintain the contact state between the rolled material 90 and the edge roll 25 equally along the entire length of the rolled material 90.

[0158] In contrast, in the second embodiment, the direction of motion of the hydraulic cylinder during the pressing position measurement is always the direction that closes the gap 28 between the rolling rolls 25. Therefore, the direction of sliding friction of the hydraulic cylinder does not change, and the measurement conditions for measuring the pressing position remain constant. Therefore, according to the second embodiment, the measurement accuracy of the width of the rolled material 90 can be further improved.

[0159] Furthermore, the correction method for the actual value of the plate width using the plate width measurement value described in the first and second modifications of the first embodiment can also be applied to the plate width control device of the second embodiment.

[0160] Explanation of symbols

[0161] 10 Reversible rolling mill

[0162] 20 Edge Rolling Machine

[0163] 22 Pressing device

[0164] 21 Press-down control device

[0165] 23 Press-down position detector

[0166] 24 Load measuring instrument

[0167] 25 Edge Roller

[0168] 30 Horizontal Rolling Mill

[0169] 40 Plate Width Actual Calculation Device

[0170] 50 Setting up a computing device

[0171] 60 Pressing position correction calculation device

[0172] 70 Tracking Device

[0173] 31 Horizontal Roller

[0174] 90 Rolled material

[0175] 110 Plate Width Meter

[0176] 200 Plate Width Control Device

Claims

1. A plate width control device for a reversible rolling mill, the reversible rolling mill comprising: an edging mill having a pair of edging rolls for width rolling of a workpiece; and a horizontal rolling mill disposed downstream of the edging mill having a pair of horizontal rolls for horizontal rolling of the workpiece, the plate width control device being characterized in that it comprises: The pressing control device is configured to activate the edging mill in a reverse rolling process in which the width rolling is not performed by the pair of edging mills but only by the horizontal rolling mill, in such a way that the pair of edging rolls contact the rolled material. The pressing position detector is configured to detect the pressing position of the edging mill when the pair of edging rolls come into contact with the rolled material during the reverse rolling process; A tracking device configured to track the position of the rolled material along its length during the reverse rolling pass; and The actual width calculation device is configured to calculate the actual width of the rolled material at multiple positions along its length based on the output of the pressing position detector and the output of the tracking device. The reduction control device is configured to be repeatedly performed during the reverse rolling pass: The edging machine is activated by reducing the distance between the pair of edging rolls from a state where the pair of edging rolls are not in contact with the material being rolled. Monitor the load measurement value of the edging mill, and detect when the load measurement value reaches the load target value as contact between the pair of edging rolls and the rolled material; and If contact between the pair of edge rolling rollers and the rolled material is detected, the edge rolling machine is activated by increasing the distance between the pair of edge rolling rollers.

2. A plate width control device for a reversible rolling mill, the reversible rolling mill comprising: an edge rolling mill having a pair of edge rolling rolls for width rolling of a workpiece; and a horizontal rolling mill disposed downstream of the edge rolling mill having a pair of horizontal rolling rolls for horizontal rolling of the workpiece, the plate width control device being characterized in that it comprises: The pressing control device is configured to activate the edging mill in a reverse rolling process in which the width rolling is not performed by the pair of edging mills but only by the horizontal rolling mill, in such a way that the pair of edging rolls contact the rolled material. The pressing position detector is configured to detect the pressing position of the edging mill when the pair of edging rolls come into contact with the rolled material during the reverse rolling process; The tracking device is configured to track the position of the rolled material along its length direction during the reverse rolling pass. A plate width actual value calculation device is configured to calculate the actual plate width at multiple positions along the length direction of the rolled material based on the output of the pressing position detector and the output of the tracking device; and A plate width gauge is located downstream of the edge rolling mill and is configured to measure the plate width of the rolled material in the forward rolling pass preceding the reverse rolling pass. The actual plate width calculation device is configured to correct the actual plate width value using the plate width predicted based on the measured value of the plate width gauge and the width expansion amount generated by the horizontal rolling.

3. A plate width control device for a reversible rolling mill, the reversible rolling mill comprising: an edge rolling mill having a pair of edge rolling rolls for width rolling of a workpiece; and a horizontal rolling mill disposed downstream of the edge rolling mill having a pair of horizontal rolling rolls for horizontal rolling of the workpiece, the plate width control device being characterized in that it comprises: The pressing control device is configured to activate the edging mill in a reverse rolling process in which the width rolling is not performed by the pair of edging mills but only by the horizontal rolling mill, in such a way that the pair of edging rolls contact the rolled material. The pressing position detector is configured to detect the pressing position of the edging mill when the pair of edging rolls come into contact with the rolled material during the reverse rolling process; The tracking device is configured to track the position of the rolled material along its length direction during the reverse rolling pass. A plate width actual value calculation device is configured to calculate the actual plate width at multiple positions along the length direction of the rolled material based on the output of the pressing position detector and the output of the tracking device; and A plate width gauge is disposed upstream of the edge rolling mill and configured to measure the plate width of the rolled material during the reverse rolling pass. The actual plate width calculation device is configured to correct the actual plate width value using the measured value of the plate width meter.

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