JP4568156B2 - Method for identifying roll profile of sheet rolling mill - Google Patents

Description

  The present invention relates to a roll profile identification method for a sheet rolling mill, and in particular, a split backup having a mechanism in which at least one of the upper and lower roll assemblies supports a work roll by a split backup roll divided into three or more in the roll axial direction. The present invention relates to a roll profile identification method for a roll type plate mill.

  Recently, split backup roll type plate rolling mill that can measure the load distribution of the split backup roll and estimate the load distribution between the rolled material and the work roll, and can estimate the plate crown and plate shape after finish rolling with high accuracy. Has attracted attention (see, for example, Patent Document 1).

In order to control the plate shape with high accuracy in the split backup roll type plate rolling mill, accurate profiles of the work roll and the split backup roll are required. As a method for identifying the roll profile, it is known that the upper and lower work rolls are tightened until the entire body part comes into contact, and the work roll profile is identified from the measured load of each divided backup roll at this time (for example, , See Patent Document 2).
JP 05-69010 A (page 3, FIG. 1 and FIG. 3) JP 06-262226 A (page 3, paragraph [0012])

  In the roll profile identification method, each divided backup roll constituting the divided backup roll is in contact with a divided backup roll having an independent reduction device and a load measuring device, only the lower work roll, or upper, lower Only profiles with split backup rolls could be identified.

  When only the load of one of the upper and lower divided backup rolls can be measured, each divided backup roll constituting the divided backup roll is in contact with the divided backup roll having an independent reduction device and load measuring device. Only one of the upper or lower work roll and the upper or lower split backup roll can identify the profile. In general, the upper and lower work rolls and the upper and lower divided backup rolls have different thermal expansion and wear depending on the respective rolls.

  Therefore, in order to identify the profile of each roll with sufficient accuracy for shape control, a work roll having a known roll profile is often incorporated, and the roll profile is identified by tightening the kiss roll before starting rolling. There is a need to. However, if the work rolls are frequently incorporated (recombined) in this way, it is necessary to stop the line for that purpose, so that the productivity is lowered, and the basic unit of the work rolls is deteriorated to raise the manufacturing cost. Thus, the conventional identification method cannot identify the profile of each roll with sufficient accuracy for shape control without impeding productivity.

  The present invention solves the above-mentioned problems of the prior art, and is capable of identifying a roll profile with high accuracy for two or more rolls without impeding productivity in a split backup roll type plate rolling mill. A roll profile identification method is provided.

Roll profile identification method of a plate rolling mill of the first aspect of the present invention, the either one above or below the upper or split backup rolls either one of the roll assembly lower is divided into 3 or more in the roll axial direction work In a roll profile identification method of a split backup roll type plate rolling mill, which has a mechanism for supporting a roll and each of the split backup rolls constituting the split backup roll has an independent reduction device and a load measuring device, the work roll axis Assuming that the direction shift amount is one pitch of the distance between the centers in the width direction of the rolls adjacent to each other in the divided backup roll axis direction, the work rolls are kiss-rolled at the work roll axial shift positions of two or more levels during idle. , Each split backup at each work roll shift position level The load of Prowl measured, is characterized by identifying the roll profile respectively for two or more rolls of the work roll and the split backup rolls on the basis of the measured load.

Roll profile identification method of a plate rolling mill of the second invention has a mechanism for supporting the upper and lower work rolls by split backup rolls roll assembly of upper and lower is divided into 3 or more in the axial direction, Each split backup roll constituting the split type backup roll is divided and backed up in the work roll axial shift amount in the roll profile identification method of a split backup roll type plate rolling mill having a vertically symmetrical structure having an independent reduction device and load measuring device. Each work roll shift position is a kiss roll tightened at a work roll axial shift position of two or more levels during idling as it is one pitch of the distance between the centers in the width direction of the rolls adjacent in the roll axial direction. Measure the load on each split backup roll at It is characterized by identifying each roll profile on the basis of crawling and the measured load for at least three or more rolls of the split backup rolls.

Roll profile identification method of the third invention of the plate rolling mill, on, on the split backup rolls roll assembly below is divided into three or more in the roll axial direction, have a mechanism for supporting the lower work roll and, in the roll profile identification method of the split backup rolls template rolling mill each divided backup rolls which constitute the upper or the lower one of the split mold backup roll having an independent pressure device and the load measuring device, the work roll axial direction Assuming that the shift amount is one pitch between the centers in the width direction of the rolls adjacent in the divided backup roll axial direction , the work rolls are kiss-rolled at the work roll axial shift position of two or more levels during idle, Measure the load of each split backup roll at the work roll shift position level. It is characterized by identifying the role profile based on the measured load on at least two or more rolls of the work roll and the split backup rolls, respectively.

  In the first, second and third inventions, as the work roll shift position level, the upper and lower work rolls are both at the mill center position, the upper and lower work rolls are both shifted in the same direction, and the upper The work roll may be tightened at a work roll shift position of three or more levels including a level at which the lower work roll shifts in the opposite direction.

  In the first, second, and third inventions, a work roll having a known roll profile is incorporated into at least one of the upper and lower work rolls, and a kiss roll is tightened before starting rolling, so that the roll profile is known. You may make it identify a roll profile about two or more rolls other than this work roll.

  Furthermore, in the first, second and third inventions, and the invention in which the kiss roll is tightened before the start of rolling, at least one of the upper and lower parts above or below a known roll profile other than a flat shape A roll may be incorporated, and a kiss roll may be tightened before starting rolling to identify the profiles of the upper and lower split type backup rolls.

Roll profile identification method of the fourth plate rolling mill of the invention, the either one above or below the split has been split backup rolls in at least the upper or the lower one of the rolls assembly than 3 in the roll axial direction work A roll of a split backup roll type plate rolling mill having a mechanism for supporting a roll, and each of the split backup rolls constituting at least one of the upper and lower split backup rolls having an independent reduction device and a load measuring device. In the profile identification method, all work rolls with known roll profiles and split backup rolls are clamped before starting rolling, and the load of each split backup roll is measured with this as the reference state, and the work roll axial shift is performed. Split the amount back up As it is one pitch of the distance between the rolls in the width direction center adjacent to the roll axial direction, and kiss tightened in the work roll shift position oversupply of 2 levels in idle after rolling, the load of each divided backup rolls Is measured for each work roll shift position level, and a change in roll profile from the reference state is obtained for each of two or more rolls based on the load measurement of the divided backup roll at each reference roll state and each work roll shift position level. The profile of each roll is identified based on the change of the roll profile.

  In the first aspect of the invention, the work rolls are kiss-rolled at the work roll axial shift positions of two or more levels during idling, and the load of each divided backup roll is measured at each work roll shift position level. This results in a large number of load measurements and identifies the roll profile based on these measurements. Therefore, the profile can be identified with high accuracy for two or more rolls. Further, since the load is measured for either one of the upper and lower divided backup rolls, the apparatus becomes simple.

In the second invention, a load measuring device is provided in each of the upper and lower divided backup rolls to measure the load of each divided backup roll. As a result, three or more roll profiles can be identified with high accuracy at two or more work roll shift position levels.

  As in the first invention, the third invention can identify the profiles of two or more rolls with high accuracy, and the load measuring device is simplified.

  In the above invention, when profiles are identified at three or more work roll shift position levels, profiles of two or more rolls can be identified with higher accuracy.

  In the above invention, by incorporating a work roll having a known profile, the identification work of the low profile is simplified and the identification time is shortened.

  The fourth invention identifies the profile by the roll profile change from the reference state of each roll based on the load measurement of the split backup roll at the reference state and each work roll shift position level. As a result, roll profile identification is accurate and simple.

(Best Mode 1)
In this form, the plate rolling mill has a mechanism for supporting the upper and lower work rolls with a split backup roll composed of divided backup rolls in which the upper and lower roll assemblies are both divided into three or more in the roll axis direction, Each of the divided backup rolls is a divided backup roll type plate rolling machine having a vertically symmetrical structure having an independent reduction device and a load measuring device. During idle, the work rolls are tightened at kiss rolls at the work roll axial shift positions of two or more levels, and the load of each split backup roll is measured at each work roll shift position level. A roll profile is identified based on the load measurement value for at least three of the rolls. The roll axis direction shift of the work roll is preferably performed in units of the arrangement pitch of the divided backup rolls in the roll axis direction.

  Fig.1 (a) is a side view of the division | segmentation backup roll type plate rolling machine which implements the roll profile identification method of this invention, FIG.1 (b) is a top view which shows roll arrangement | positioning of an upper roll assembly.

  The split backup roll type plate rolling machine includes an upper roll assembly 10 and a lower roll assembly 40. The upper and lower roll assemblies 10 and 40 have upper and lower work rolls 13 and 43 and upper and lower split-type backup rolls 20 and 50, respectively. Upper and lower inner housings 15 and 45 are attached to the housing 5 so as to be movable up and down. The upper and lower work rolls 13 and 43 are supported by upper and lower work roll chocks 12 and 42 provided on the upper and lower inner housings 15 and 45, respectively. The upper and lower split type backup rolls 20 and 50 are attached to the upper and lower inner housings 15 and 45. An upper main reduction device 17 and an upper main load measuring device 18 are provided between the housing 5 and the upper inner housing 15.

  The upper division type backup roll 20 includes seven upper division backup rolls 21 to 27. As shown in FIG. 1 (b), the upper divided backup rolls 22, 24, 26 are alternately arranged on the rolling mill entrance side, and the upper divided backup rolls 21, 23, 25, 27 are alternately arranged on the outlet side in the roll axis direction. ing. The upper divided backup rolls 21 to 27 are provided with reduction devices 301 to 307, load measurement devices 321 to 327, and reduction position measurement devices 341 to 347, respectively.

  The lower division type backup roll 50 is configured in the same manner as the upper division type backup roll 20, and each of the lower division backup rolls 51 to 57 is also a reduction device 601 to 607, a load measurement device 621 to 627, and a reduction position measurement device 641 to 647. It has. The upper and lower divided backup rolls 21 to 27 and 51 to 57 are arranged symmetrically on the upper and lower sides.

  Here, in the divided backup roll type plate rolling machine configured as described above, a method for identifying the roll profile of the work roll and the n divided divided backup roll will be described.

  The profile of the work roll is represented by the position in the roll axial direction immediately below the center of the width of each divided backup roll that compresses the work roll and the deflection of the work roll axis. The profile of the split-type backup roll is expressed by the roll axial position and the displacement at the width center of each split backup roll on the contact surface with the work roll.

The load acting on the i-th divided backup roll detected by the load measuring device provided in the divided backup roll is q _i (known number), and the load between the rolled material and the work roll corresponding to the position is p _i (unknown number). , The deformation matrix of the work roll axis deflection is K ^W _ij (a known number), the deformation matrix of the split type backup roll is the K ^B _ij (the number of deflections that are applied to the element of i when a load is applied to the element of the known number, j Influence), C ^w _i (unknown number) for the work roll profile expressed in the form of a roll crown, C ^B _i (unknown number) for the split-type backup roll profile, and y ^w _i for the work roll axial deflection. Equation (1) is obtained from the matching condition that no gap is generated between the backup roll and the work roll.
y ^W _i = K ^B _ij q _j + C ^W _i + C ^B _i (1)
In addition, in the mathematical expression of this specification, when there is repetition of the subscript, it is expressed using Einstein's sum rules. K ^B _ij is an influence coefficient matrix representing the displacement of the i-th divided backup roll when a unit load is applied to the j-th divided backup roll. Here, the housing variables and the work roll to the divided-type backup roll are used. The deformation | transformation matrix including the flat deformation of both rolls by contact of this is represented. Further, since the formula (1) is common to the upper and lower sides, the subscripts T and B are omitted.

On the other hand, the work roll axis deflection y ^W _i acts between the deformation matrix K ^W _ij (a known number, the effect of deflection on the element i when a load is applied to the element j) and the rolled material to the work roll. Using the rolling load distribution p _i (unknown number), it is expressed by equation (2).
_{^{y W i = K W ij (}} p j -q j) ...... (2)
Equation (1), erase the more ^y _{W i} Equation (2), Equation (3) is obtained and arranging.
p _i = q _i + [K ^W ] ⁻¹ _ij (K ^B _jk q _k + C ^W _j + C ^B _j ) (3)
In the above right hand side, [K ^W ] ⁻¹ _ij is an inverse matrix of K ^W _ij and is a known amount by calculation or measurement together with K ^B _jk . Since q _i can be measured, p _i , C ^W _j , and C ^B _j are unknowns.

Here, during idling, the upper and lower work rolls are brought into contact with each other and tightened until the entire body part comes into contact (kiss roll tightening), and the load and displacement of each divided backup roll are measured. The profile of the split-type backup roll is C ^B _i , the displacement u _i of each split backup roll (the side pushed into the rolled material is positive), and the variables related to the upper roll system and the lower roll system are the superscripts T, B (T: upper roll side, B: lower roll side). When two upper subscripts are arranged, the first subscript represents the roll type (W: work roll, B: backup roll), and the second subscript represents the distinction between the upper and lower roll systems. FIG. 2A shows a case where both the upper and lower work rolls are in the mill center.

From the compatibility condition between the split backup roll and work roll shown in Equation (1),
Upper roll _{^{system: y WT i = C WT i}} + K BT ij q T j + C BT i -u T i ...... (4)
Lower roll _{^{system: y WB i = -C WB i}} -K BB ij q B j -C BB i + u B i ...... (5)
From the work roll deflection calculation formula: Upper roll system: y ^WT _i = K ^WT _ij (p _j −q ^T _j ) ...... (6)
Lower roll system: y ^WB _i = −K ^WB _ij (p _j −q ^B _j ) ...... (7)
From the conformity conditions of the upper and lower work rolls,
y ^WT _i + C ^WT _i -y ^WB _i + C ^WB _i + K ^fW _ij p _j = 0 (8)
The above formulas (4) to (8) all extract only the relative displacement from the mill center, and roll profiles ^CWT _i , ^CWB _i , ^CBT _i , ^CBB _i , split backup roll displacement u ^T _i , u ^B _i and deformation matrix K ^BT _ij , K ^BB _ij , K ^WT _ij , K ^WB _ij , and flat deformation matrix K ^fW _ij of the upper and lower work rolls are all set to zero displacement of the mill center. It is assumed that the zero point is corrected.

When the number of roll divisions is n, Equations (4) to (8) seem to form 5n equations, but it is substantially clear if y ^WT _i and y ^WB _i are eliminated. Consists of 3n equations (4), (5) and (8). The number of unknowns corresponding to this is 5n of C ^WT _i , C ^WB _i , C ^BT _i , C ^BB _i , and p _j .

Therefore, this equation alone cannot be solved. That is, 2n equations are lacking. In order to make up for this missing equation, a condition is employed in which the work rolls are kiss-rolled at each work roll axial shift position of one level or more and the load of each divided backup roll is measured at each work roll shift position level. . For example, as shown in FIG. 2B, when the upper work roll is shifted to the drive side by one pitch of the divided backup roll and the lower work roll is shifted in the direction opposite to the upper work roll, that is, the work side, the divided backup is performed. New matching conditions between the roll and the work roll, that is, equations (9) and (10) are newly obtained.
Upper roll _{^{system: y WT i = C WT i}} + 1 + K BT ij q T j + C BT i -u T i ...... (9)
Lower roll _{^{system: y WB i = -C WB i}} -1 -K BB ij q B j -C BB i + u B i ... (10)
Becomes 5n number of equations by using Equations (9) and (10), ^C _WT i by solving the simultaneous _{^{equations, C WB i, C BT i}} , C BB i, obtains the 5n unknowns of _{p j} be able to.

(Best Mode 2)
In this embodiment, the plate rolling mill shown in FIG. 1 is provided with an independent reduction device and a load measurement device on each of the divided backup rolls only on the upper side or the lower side. During idle, the work roll is tightened at the work roll axial shift position of two or more levels, and the load of each divided backup roll is measured at each work roll shift position level. A profile is identified for each of at least two or more rolls based on the load measurements.

In this case, the load q _j and the displacement u _i of each split backup roll of the split backup roll that is not provided with the independent reduction device and load measuring device are unknown. Each split backup roll displacement of the split type backup roll that is not provided with an independent reduction device and load measuring device is not movable, that is, if it is fixed, zero, even if it has only a reduction device Can be treated as known from known or other measurement or estimation methods. Therefore, when the roll division number is n. There are 6n unknowns: ^CWT _i , C ^WB _i , C ^BT _i , C ^BB _i , p _j, q _j (q ^T _j or q ^B _j ). Because there are 5n equations mentioned earlier. This alone cannot be solved.

Therefore, in order to make up for this missing equation, the work rolls are kiss-rolled at each work roll axial shift position of two or more levels, and the load of each divided backup roll is measured at each work roll shift position level. Is used. For example, when the upper work roll is shifted to the drive side and work side by one pitch of the split backup roll and the lower work roll is shifted in the opposite direction to the upper work roll, that is, the work side and drive side, New equations (11) and (12) are obtained for the new matching conditions between the rolls, that is, the equations (9) and (10) described above.
Upper roll _{^{system: y WT i = C WT i}} -1 + K BT ij q T j + C BT i -u T i ... (11)
Lower roll _{^{system: y WB i = -C WB i}} + 1 -K BB ij q B j -C BB i + u B i ... (12)
Equation (11) and becomes 7n number of equations by using the equation (12), ^C _WT i by solving the simultaneous _{^{equations, C WB i, C BT i}} , C BB i, p j, of _{q j} 6n number of An unknown number can be obtained.

  In the above embodiment, the upper and lower sides are split-type backup rolls, but one may be a non-split-type backup roll (for example, a backup roll 60 of a four-high plate rolling mill) as shown in FIG. .

(Best Mode 3)
In this form, as shown in FIG. 4, in the form 1 or 2, the work roll shift position level is the level (a) in which the upper and lower work rolls are both at the mill center position, and the upper and lower work rolls are both in the same direction. The work roll is tightened at a work roll shift position of three or more levels including the level that shifts to (3) and the levels (b) and (c) where the upper and lower work rolls shift in opposite directions. When both the upper and lower work rolls are at the level at the mill center position, the above-described equations (4) and (5) are used. Furthermore, in the case of level lower work rolls are shifted in the same direction together, for example, upper roll _{^{system: y WT i = C WT i}} + 1 + K BT ij q T j + C BT i -u T i ... (13)
Lower roll _{^{system: y WB i = -C WB i}} + 1 -K BB ij q B j -C BB i + u B i ... (14)
When the upper and lower work rolls are at a level that shifts in the opposite direction, the above formulas (11) and (12) are used.

(Best Mode 4)
In this form, in the above-mentioned forms 1, 2, or 3, the roll profile is known, and either one of the lower work rolls is incorporated into the roll assembly, and the kiss roll is tightened before starting rolling, so that the roll profile is known. Each roll profile is identified for two or more rolls other than work rolls.

(Best Mode 5)
In this form, in the above-mentioned form 1, 2 or 3, the profile of one work roll is a known roll profile shape other than the flat shape, and the lower work roll is incorporated, and the kiss roll is tightened before starting rolling, Identify each of the lower split backup roll profiles.

(Best Mode 6)
In this embodiment, the plate rolling machine is a split backup roll type plate rolling machine shown in FIG. Then, all work rolls and split-type backup rolls whose roll profiles are known are clamped before starting rolling, and the load of each split backup roll is measured using this as a reference state. The kiss roll is tightened at a work roll shift position level of 2 levels or more during idle after rolling, and the load of each divided backup roll is measured for each work roll shift position level. A roll profile change from the reference state is obtained for each of two or more rolls based on the load measurement value of the divided backup roll at the reference state and each work roll shift position level, and each roll profile is determined based on the roll profile change. Is identified. In this case, since the work roll profiles C ^WT _i and C ^WB _i are known, the 5n equation systems of the equations (4) to (10) are expressed as C ^BT _i , C ^BB _i , y ^WT _i , y ^WB _i. , P _j to solve for the 5n unknowns, the profile of the split backup roll can be determined.

  Examples of the present invention are shown below. The intelligent rolling mill used is the same as the rolling mill shown in FIG. The divided backup rolls 21 to 27 and 51 to 57 are seven divided backup rolls having a diameter of 500 mm, and the width of each divided backup roll has a length of 220 mm. Further, lower upper work rolls 13 and 43 having the same length of 1540 mm and a diameter of 300 mm are arranged.

After rolling a sheet material of a general steel (S45C) having a plate thickness of 4 mm, a plate width of 1.5 to 1.0 m, and a length of 50 m to about 5000 sheets at a rolling reduction of 0.2 to 0.5%, each roll has a room temperature. The profiles of the upper and lower backup rolls and work rolls were estimated by the method described above, and each roll was pulled out to measure the profiles. Both rolls have an initial crown of zero. The result is shown in FIG. In FIG. 5, the difference between the measured and estimated roll profiles from the initial roll profile, that is, the wear amount is shown.
It was confirmed that the roll profiles of the work roll and the divided backup roll were obtained with high accuracy according to the present invention.

It is a side view which shows the division | segmentation backup roll type plate rolling machine which enforces the method of this invention. It is a top view which shows arrangement | positioning of the upper division | segmentation backup roll of the plate rolling machine shown to Fig.1 (a). It is a front view which shows the state which shifted the work roll of the division | segmentation backup roll type | mold plate rolling machine shown in FIG. 1 to the reverse direction. It is the front view and side view which show the upper division | segmentation backup roll lower non-partition type backup roll type plate rolling machine which enforces the method of this invention. It is a front view when a work roll is shifted in the reverse direction up and down in the split backup roll type plate rolling machine shown in FIG. It is a diagram which shows the profile measurement result by this invention.

Explanation of symbols

5 Housing 10, 40 Roll assembly 12, 42 Work roll chock 13, 43 Work roll 15, 45 Inner housing 17 Upper main reduction device 18 Upper main load measuring device
20, 50 Split type backup roll 21-27 Upper split backup roll 301-307 Upper split backup roll reduction device 321-327 Upper split backup roll load measuring device 341-347 Upper split backup roll down position measuring device 51-57 Lower split backup Rolls 601 to 607 Lower divided backup roll reduction device 621 to 627 Lower divided backup roll load measuring device 641 to 647 Lower divided backup roll reduction position measuring device P Rolled material

Claims (7)

One of the roll assemblies of the upper or lower has a mechanism for supporting the upper or the lower one of the work rolls by split backup roll which is divided into 3 or more in the roll axial direction, the split backup rolls In the roll profile identification method of a divided backup roll type plate rolling mill, each of the divided backup rolls constituting the roll has an independent reduction device and load measuring device, and the work roll axial shift amount is adjacent to the divided backup roll axial direction. It is assumed that the pitch is one pitch between the center in the width direction of the machine, and the work rolls are kiss-rolled at the work roll axial shift position of 2 levels or more during idling, and the load of each divided backup roll at each work roll shift position level. Based on the load measurement value. Roll profile identification method of a plate rolling mill, characterized in that the two or more rolls of crawling and split backup rolls identifying roll profile, respectively. A mechanism in which the roll assemblies of the upper and lower supports the upper and lower work rolls by split backup roll which is divided into 3 or more in the axial direction, each divided backup rolls constituting the split backup rolls are each independently In a roll profile identification method for a split backup roll type plate rolling mill having a vertically symmetrical structure having a reduced reduction device and a load measuring device, the shift amount in the work roll axial direction is determined between the widthwise centers of the rolls adjacent to each other in the split backup roll axial direction. As the pitch is 1 pitch, the work roll is tightened at each work roll axial shift position of 2 levels or more during idle, and the load of each divided backup roll is measured at each work roll shift position level. And a small number of split backup roles Roll profile identification method of a plate rolling mill, characterized in that Kutomo three for more rolls identifying each roll profile based on the measured load. Moreover, on the bottom of the split backup rolls roll assembly is divided into 3 or more in the roll axial direction, it has a mechanism for supporting the lower work roll, the upper or the lower one of the split backup rolls In a roll profile identification method for a divided backup roll type plate rolling mill, in which each divided backup roll constituting has an independent reduction device and load measuring device, the shift amount in the work roll axial direction is determined for the roll adjacent to the divided backup roll axial direction. Measures the load of each split backup roll at each work roll shift position level by tightening the work roll at the work roll axial shift position of 2 levels or more during idling as it is 1 pitch of the distance between the centers in the width direction. Of work roles and split backup roles Roll profile identification method of a plate rolling mill, characterized by identifying each roll profile on the basis of the load measurements for at least two or more rolls.   As the work roll shift position level, the upper and lower work rolls are both at the mill center position, the upper and lower work rolls are both shifted in the same direction, and the upper and lower work rolls are shifted in opposite directions. The roll profile identification method for a plate rolling mill according to claim 1, 2 or 3, wherein the work roll is tightened at a work roll shift position including three or more levels.   At least one of the upper and lower work rolls is assembled with a work roll having a known roll profile, kiss roll tightened before the start of rolling, and the roll profile is set for two or more rolls other than the known work roll. The roll profile identification method of the plate rolling machine according to any one of claims 1 to 4, wherein each is identified.   A lower work roll is incorporated on a known roll profile having at least one of the upper and lower sides other than the flat shape, the kiss roll is tightened before starting rolling, and the profiles of the upper and lower split type backup rolls are respectively identified. The roll profile identification method of the plate rolling machine of any one of 1-4. A mechanism at least above or below one of the rolls assembly for supporting the upper or the lower one of the work rolls by 3 or more divided by the split backup rolls in the roll axial direction, either at least above or below Each of the divided backup rolls constituting the one of the divided backup rolls is a roll profile identification method for a divided backup roll type plate rolling mill having an independent reduction device and a load measuring device. Tighten the roll and split backup roll before starting rolling, measure the load of each split backup roll with this as the reference state, and determine the work roll axial shift amount as the width of the roll adjacent to the split backup roll axial direction. Distance between center of direction 1 as it is the pitch, and kiss tightened in the work roll shift position oversupply of two levels during idle after rolling, to measure the load of each of the divided backup rolls for each work roll shift position level, the reference state And based on the load measurement value of the divided backup roll at each work roll shift position level, the roll profile change from the reference state is obtained for each of two or more rolls, and the profile of each roll is identified based on this roll profile change. A roll profile identification method for a plate rolling machine.