JPH11104738A - Roller leveler rigidity-measuring method and positioning method for each roll - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily grasp a rigidity of a roller leveler and decide a setting position of each roll based on a relief volume foreseeable from the rigidity grasped. SOLUTION: This method expresses a rigidity of the roller leveler by a rigidity matrix and an original position amended volume of each roll 1 setting position based on the setting positions of each roll, an actual relative position of each roll 1, and each roll load under the plural roll load patterns. The actual relative position of each roll 1 can also be obtained by inserting an object 8 between the upper and the bottom roll groups. Further, each roll load can also be obtained from a depth of a depressed mark left on the object 8 inserted between the upper and the bottom roll groups 3 and 4. The relief volume of each roll 1 is to be foreseen from the rigidity thus grasped, and the setting position of each roll 1 is decided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to flattening or curving of a material to be corrected by arranging a plurality of rolls vertically in a staggered manner and repeatedly bending the material between the rolls. In a roller leveler that corrects the shape, using the rigidity of the roller leveler, a method of predicting the displacement of each roll generated due to the roll reaction force due to the correction, and a method of measuring the rigidity of the roller leveler necessary for that, and setting the roll position It is about the method.

[0002] The roller leveler referred to in this specification is
In addition to those that simply bend by a roll, those that bend by a roll after applying tension to the material to be corrected are also included. Also, in this specification, when simply called a role,
A “work roll” that directly contacts the material to be corrected and bends the work is referred to as a work roll only when it is distinguished from a backup roll that supports the work roll.

[0003]

2. Description of the Related Art A roller leveler in which a plurality of rolls are arranged vertically in a staggered manner in order to flatten warpage generated in a rolling process or a cooling process of a plate material, a shape material, a tube material, a wire material, or the like, or to correct a wave shape. Is used. The correction action by the roller leveler is to flatten the material to be corrected or to give a desired warp or corrugation by repeatedly bending the material to be corrected.

Japanese Unexamined Patent Application Publication No. 53-87962 discloses an indentation amount of an upper roll group, which is a roll set value, based on a maximum working degree on an inlet side, a working degree on an outlet side, a sheet thickness, a sheet width and a yield point stress. And a method for determining the outlet pushing amount.

However, when the bending rigidity of the material to be corrected is large, the reaction force generated by the correction is large, so that the roll is deformed, or the housing of the roller leveler is bent or elongated, and the material to be corrected is passed through the roller leveler. The actual roll position when it is present differs from the set roll position by these deformations.

To prevent such roll displacement, each straightening roll is supported by a backup roll,
Although measures such as increasing the rigidity of the housing have been taken, it is difficult to completely eliminate the displacement of each roll because the equipment becomes huge.

In order to correct the roll displacement, Japanese Patent Application Laid-Open No.
Japanese Patent Application Laid-Open No. 2-173027 discloses a method in which the displacement of each roll is detected online, the amount of correction of each roll position is calculated, and control is performed so that each set roll position is equal to each roll position during correction work. It is shown.

[0008]

Generally, a roller leveler has about 10 or more straightening rolls, and a backup roll for reducing the displacement of the rolls is provided above the upper roll and below the lower roll. Because of this, it is usually difficult to incorporate a sensor for accurately grasping the displacement of each roll online, and the technique disclosed in Japanese Patent Application Laid-Open No. 62-173027 can be a practical solution. Absent.

As an alternative technique for directly measuring the displacement of each roll, a technique of accurately predicting the displacement of each roll using a relational expression between the load of each roll and the displacement of each roll can be considered. Hereinafter, in this specification, constants such as coefficients included in the relational expression between each roll load and the displacement of each roll are referred to as “rigidity”.
I will call it.

In order to obtain the rigidity of a rolling mill or the like, a measured value of a dimensional index such as a set value of a rolling load, a roll gap, and a thickness after rolling is used, or a so-called so-called contact between upper and lower rolls is used. It is a common practice to perform tightening by a kiss roll to determine the relationship between the load and the displacement of the roll. However, in a roller leveler, only bending is applied to a material to be corrected, and a dimension index such as a thickness of the material to be corrected does not change. In addition, since the upper and lower rolls are opposed to each other in the rolling mill, the magnitude of the amount of tightening of the roll by the kiss roll is equal to the magnitude of the displacement of the roll, whereas the rolls are arranged in a staggered manner in the roller leveler. Therefore, it is impossible to take a kiss roll state.

A roller leveler is generally composed of an upper roll group,
Since each lower roll group is held by an integral housing, the displacement of each roll is affected by not only the roll load but also other roll loads. On the other hand, conventionally, the displacement of each roll of the roller leveler has been handled simply by a load applied to the entire upper roll group or the lower roll group, or only the roll load is affected. The accuracy in estimating the displacement of was insufficient.

The present invention provides a method of accurately predicting the position of each roll during straightening of a roller leveler in which a plurality of rolls are arranged in a staggered manner. It is an object of the present invention to provide a method for easily and accurately measuring. It is still another object of the present invention to provide a roll setting method for determining the set position of each roll after predicting the displacement of each roll using the stiffness obtained by the present stiffness measuring method.

[0013]

In order to achieve the above object, according to the invention of claim 1, a plurality of rolls are arranged in a staggered manner vertically and repeatedly bent through the material to be corrected between the rolls. By flattening the warp of the material to be corrected,
Or, in a roller leveler that corrects the wave shape, under a plurality of roll load patterns in which the load distribution applied to each roll is changed, the set position of each roll, the position of each roll at the time of loading, and the roll load In addition, a stiffness matrix that relates the load applied to each roll and the displacement of each roll is obtained. This rigidity matrix can be used as an index of the rigidity of the roller leveler.

According to a second aspect of the present invention, in the method of the first aspect, not only the rigidity matrix relating the load applied to each roll and the displacement of each roll, but also the origin correction amount of the set position of each roll. The feature is that it is also required. The rigidity matrix and the origin correction amount of the set position of each roll can be used as an index of the rigidity of the roller leveler. According to the second aspect of the present invention, even if the origin of the set position of each roll is not accurately adjusted, the position of each roll under load can be accurately obtained.

According to a third aspect of the present invention, in the method according to the first aspect, a load is applied to the upper and lower rolls with the reference test piece interposed between the upper roll group and the lower roll group, and the reference test piece is rigid. It is characterized in that the displacement of each roll under the load is obtained by ignoring the deformation and correcting the elastic deformation by elasticity calculation. According to the third aspect of the invention, when the displacement of each roll cannot be directly measured, the displacement can be easily and accurately measured.

According to a fourth aspect of the present invention, in the method according to the first aspect, a load is applied to the upper and lower rolls with a reference test piece interposed between the upper roll group and the lower roll group via a plastic body.
The method is characterized in that a dimensional index of an impression of a roll remaining on the plastic body is measured, and each roll load is obtained based on the measured index.

According to a fifth aspect of the present invention, in the method according to the first aspect, a load is applied to the upper and lower rolls with a reference test piece having a strain gauge attached between the upper roll group and the lower roll group, It is characterized in that each roll load is obtained by elasticity calculation from the measured value of the strain gauge. According to the fourth and fifth aspects of the invention, when the applied load of each roll cannot be directly measured, the applied load can be measured easily and accurately.

According to a sixth aspect of the present invention, the displacement of each roll is predicted using the rigidity of the roller leveler measured by the method described in the first aspect and each roll load predicted in advance, and the predicted displacement of each roll is estimated. The setting position of each roll is determined on the basis of. According to the invention of claim 6, since the displacement of each roll can be predicted using the rigidity of the right roller leveler obtained by the above method, the optimum setting position of each roll can be determined. Thereby, it is possible to perform the correction at each roll position that is optimal for the purpose of the correction, such as flattening the material to be corrected or giving a desired warp or corrugation to the material to be corrected.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, the rigidity of a roller leveler is expressed by using a rigidity matrix. That is, the displacement △ _i of each roll and the load P _{i of} each roll are related by the following equation using the rigidity matrix K _ij .

(Equation 1) Here, the subscript i indicates a value related to the i-th role, and n is the total number of rolls considered. The stiffness matrix K _ij represents the effect of the j-th roll load on the i-th roll displacement. In addition, in the equation (1), when the elastic deformation of the roller leveler includes nonlinearity,
Preferably, the relationship between the displacement △ _i of each roll and the load P _{i of} each roll is expressed using a higher-order equation as in the following equation.

(Equation 2) In the equation (2), m is A arbitrarily selected according to the order of the relational expression between the displacement △ _i of each roll and the load P _{i of} each roll.
To the sum of B. In the equation (1), preferably, the stiffness of the roller leveler is expressed using not only the stiffness matrix but also the origin correction amount of the roll set position. That is, the displacement △ _{i of} each roll is calculated by the rigidity matrix K
Using a _ij, the origin correction value (ye) g _i of the set position of the rolls is expressed by the following equation.

(Equation 3) As shown in FIG. 3, the displacement △ _i of each roll is defined by a deviation between the position y _i of each roll under load and the set position s _{i of} each roll. Δ _i = y _i −s _i (4) For the position y _i of each roll, the following equation is obtained from the equations (1) and (4).

(Equation 4)

[0020] Now, in order to measure the stiffness of the roller leveler, a load of correction the reaction force in the same direction and loaded on the roll before the straightening work start, setting positions s _i for each role in this case, each roll under load position y _i of collecting each roll load P _i under load. Here, instead of using the measured values as they are, each roll load P _i is determined by the method of least squares or final determination so as to satisfy the condition equation (6) for balancing the force and the condition equation (7) for including the moment. It is preferable to use one obtained by correcting the measured value using a coefficient method or the like.

(Equation 5) x _i indicates the longitudinal coordinate of the position of the i-th roll as shown in FIG.

The set position s _i of each roll, the position y _i of each roll when loaded, and each roll load P _i when loaded are sampled, and these measured values, preferably, for each roll load P _i , are: By substituting a value corrected so as to satisfy the force balance condition expression (6) and the moment balance condition expression (7) into the expression (5), and solving the expression (5) with respect to the stiffness matrix K _ij , Identify the matrix K _ij . In order to solve the equation (5) for the stiffness matrix K _ij , it is necessary to collect and substitute the above data for at least n types of load patterns. However, the stiffness matrix K _ij is indefinite, and cannot be obtained. . this is,
For n rolls, the set position s _i and the actual roll position y _i each have n degrees of freedom, whereas for each roll load P _i , the force balance condition equation (6) and the moment balance condition This is because the constraint condition that the correction is made so as to satisfy the expression (7) works, and the degree of freedom becomes n-2. This problem can be solved, for example, as follows.

In general, a rigid displacement component such as movement or rotation that does not accompany the deformation of the entire roller leveler among the positions of the rolls is meaningless for the correction bending deformation.
Since only the relative position excluding the rigid displacement component is significant,
The displacement △ _{i of} each roll calculated by the equation (1) may be specified under an arbitrary condition with respect to the rigid body displacement component. For example, any two rolls (for example, the most-entry-side roll and the most-outmost-roll) ) Is selected, or the displacement △ _{i of} each roll is determined by the least squares method using a linear expression (ax _i + b) relating to the coordinates in the length direction and the deviation (△ _i ^ref ), that is, △ _i = ax _i + b + △
When expressed as _i ^ref , the linear expression component (ax _i ten b)
Is newly set to zero, the stiffness matrix K _ij can be obtained from equation (5).

For the position y _i of each roll under load,
It is generally difficult to measure directly online,
It is possible to measure directly or indirectly off-line, and thus the stiffness may be determined. Preferably, the position _yi of each roll under this load is determined by sandwiching a reference test piece between the upper roll group and the lower roll group, and ignoring the deformation by regarding the reference test piece sandwiched between the upper and lower roll groups as a rigid body. Alternatively, the position _{yi of} each roll is determined by regarding the reference test piece as an elastic body and correcting the amount of elastic deformation by elasticity calculation.

Each roll load can be directly measured when each roll has a load cell. If each roll does not have a load cell, for example, a reference test piece is sandwiched between the upper roll group and the lower roll group via a plastic body, and each roll load is applied to the depth of eaves remaining on the plastic body or It is determined by dimensional index such as area. In another method, a reference test piece made of an elastic body having a strain gauge attached thereto is sandwiched between an upper roll group and a lower roll group, and the deformation of the reference test piece is obtained from the measured value of the strain gauge. Each roll load at the time is obtained by elasticity calculation.

Hereinafter, the method of the present invention will be described in detail with reference to the drawings. FIG. 2 is a side view showing the outline of the roller leveler. The roller leveler includes an upper roll group 3 having one or a plurality of work rolls 1, one or a plurality of backup rolls 2 above and below, a lower roll group 4, a housing 5 holding the upper roll group 3, and a lower roll group. , And a housing post 7. FIG.
In the example of the roller leveler shown in (1), the work roll 1 has a backup roll 2 in order to reduce the displacement and deflection of the work roll 1 due to the roll reaction force generated by the straightening, but there is also a case where the backup roll 2 is not provided. . Also, at the time of straightening, the upper roll group 3 or the lower roll group 4
In addition to the roller leveler that can change the set position of the work roll 1 by tilting and pushing the roll, the set position of each work roll 1 can be changed directly or the position of the backup roll 2 can be changed indirectly. There is also a roller leveler that can change the setting position of the work roll 1 in a general manner. In addition, as shown in FIG. 6, a pressing roll 11 supported by a housing 13 may be provided outside the housings 5 and 6 of the roller leveler main body 12 to contribute to deformation of the material to be corrected. In the present invention, in addition to the roll installed in the integral housing, the pressing roll 11 installed separately from such an integral housing is also required when it is related to the deformation of the material to be corrected. And rolls.

The set position s _i of each roll in a plurality of load patterns in which the distribution of the load applied to each roll is changed in equation (5), the position y _i of each roll when loaded, and each roll load P when loaded. _{If i} is sampled and substituted, a stiffness matrix K _ij can be obtained. In addition, each roll load P _i at the time of load
It is preferable to use a value obtained by correcting the measured value using the least square method, the undetermined coefficient method, or the like so as to satisfy the force balance condition expression (6) and the moment balance condition expression (7). Further, each roll position does not need to be an individual absolute position, but may be a relative position. In the following, a description will be given assuming that a coordinate system in which the displacement of any two rolls, for example, the innermost roll and the outermost roll is zero, is selected as a condition to be given in order to remove the rigid displacement component. . When a coordinate system in which the displacements of the innermost roll and the outermost roll are set to zero is selected, as shown in Expression (8), the stiffness matrix K _ij includes the first column, the last column, the first row, and the last The row component becomes zero.

(Equation 6) Thus, the unknown in equation (5) is (n−2) × (n
-2) K _ij components. Thus, the number of unknowns is (n−2) ² , that is, (n ² −4n + 4).

The number of load patterns used in the experiment for measuring the stiffness matrix K _ij should be at least independent condition numbers, that is, (n−2). At this time, the number of equations obtained in the experiment is (n−2) × (n−2), that is, (n ² −4n + 4). Set position s _i of each roll obtained per each load pattern, the position y _i of each roll under load, and by substituting the respective roll load P _i in expression (5) relates to the unknowns K _ij (n ² - 4n + 4) The simultaneous equations are obtained, and the stiffness matrix K _ij can be obtained by solving the equations.

The position y _i of each roll under load is directly measured using a sensor or the like, and the measured value is used. But,
When it is difficult to directly measure using a sensor or the like, for example, a reference test piece 8 is placed between the upper roll group 3 and the lower roll group 4 as shown in FIG. A load is applied to each roll by pushing it in, and the set position s _i of each roll and the load P _i of each roll at that time are measured. It is desirable that the cross-sectional shape of the reference test piece 8 be uniform in the longitudinal direction so that the amount of elastic deformation (deflection) can be easily calculated.

That is, the amount of elastic deformation at the position of each roll of the reference test piece 8 sandwiched between the upper and lower roll groups 3 and 4 is represented by δ.
_i , where x _i is the longitudinal coordinate of the position of each roll, the following equation is obtained between each roll and the position y _{i under} load. y _i = δ _i + α to βx _i (9) Here, α and β are unknown constants representing unknown rigid body displacement components, and are different for each load pattern of an experiment performed for measuring rigidity. When the reference test piece 8 sandwiched between the upper and lower roll groups 3 and 4 is regarded as a rigid body, the amount of elastic deformation (deflection) δ _{i at} each roll position is zero, while the reference test piece 8 is regarded as an elastic body. If the the elastic deformation amount at each roll position (deflection) [delta] _i, because each roll load P _i is sought indefinite linear expression component (alpha
Except for ββx _i ), it can be obtained from the beam bending theory. The dent of each roll 1 due to the contact load at the point of contact with the reference test piece 8 can be easily obtained by calculation, but usually the dent amount is small and can be ignored. Thus, by applying a load to each roll 1 with the reference test piece 8 interposed between the upper and lower roll groups 3 and 4,
The position y _i of each roll under load is defined as an indefinite rigid displacement component α
Can be obtained except for the ten .beta.x _i, in this case, from equation (5) and equation (9), the following equation is obtained.

(Equation 7) From this, the unknown in equation (10) is (n−2) ×
In addition to the (n−2) K _ij components, unknown constants α and β that are different for each roll load pattern of an experiment performed to measure the stiffness are also unknowns. It can be obtained immediately from the condition of Δ ₁ = △ _n = 0.

Each roll load can be measured directly when each roll has a load cell. However, if each roll does not have a load cell,
For example, a reference test piece is sandwiched between the upper roll group and the lower roll group via a plastic body, and the correlation with each roll load such as the depth or area of an indentation remaining on the plastic body is determined by a clear dimensional index. Each roll load can be determined. For example,
As shown in FIG. 8, an aluminum layer was attached to the surface layer and the back layer of the reference test piece 8 made of ordinary steel, sandwiched between the upper and lower roll groups 3 and 4, and a load was applied. Then, the aluminum layer is taken out, and the depth of the impression of the roll 1 remaining on the surface of the aluminum layer is measured. The relationship between the depth of the indentation and the applied roll load is determined in advance using a generally used compression tester, and the depth of the indentation when the reference test piece 8 is pushed in by the work roll 1 is determined. Find the load from. However, in the case of this method, with respect to the position y _i of each roll, not only the correction of the elastic deformation [delta] _i of the center layer of the reference test piece 8 was attached to the surface layer and the backing layer of the reference specimen 8 It is also necessary to correct the depth of the roll impression left on the aluminum layer. In addition, a load is applied between the upper roll group 3 and the lower roll group 4 with the upper and lower rolls sandwiching a reference test piece made of an elastic body to which a strain gauge is attached, and each roll load is obtained from this strain by elasticity calculation. be able to. For example, as shown in FIG.
An elastic plate is sandwiched between the upper and lower roll groups 3 and 4 as a reference test piece 8, and a strain gauge is attached to the surface of the reference test piece 8 opposite to the point of contact with each roll 1 to apply a load using the rolls. The curvature immediately below each roll of the test piece 8 can be obtained. The plate thickness of the reference test piece 8 is t, the longitudinal strain value by a strain gauge attached to the surface of the reference test piece 8 opposite to the contact point with each roll 1 is ε _i , and the curvature given by each roll is κ _i. Then, there is the following relationship. _{ε i = tκ i / 2 (} i = 1~n) (11) than the curvature kappa _i at each roll, the bending moment M _i acting on the reference test piece 8 at a point of contact with each roll, reference specimens 8
Is E and the plate width is b, it can be obtained by the following equation. Relationship between ^{_{M i = Ebt 3 κ i /}} 12 (12) the bending moment M _i and the roll load P _i acting on the reference test piece 8 at a point of contact with each roll is given by the following equation.

(Equation 8) Using equation (11) to (13), the strain calculated deformation by roll load reference specimen 8 pasted gauge, than this can be determined the roll load P _i.

In this manner, the rigidity of the roller leveler, that is, the rigidity matrix K _ij in consideration of the fact that not only the load of the roll but also the load of the other rolls influence the displacement of each roll, In addition, if the rigidity is used, by substituting the expected value of each roll reaction force generated by the correction into the equation (1), the displacement of each roll generated by the correction can be accurately calculated. It is possible to predict well. Various formulas for predicting each roll reaction force when actually passing through the material to be corrected have been proposed, for example, in “Mitsubishi Heavy Industries Technical Report”, Vol. 25, No. 4, (1988), pages 321 to 326. It can be obtained by calculation as shown. Further, by predicting the displacement of each roll by such a method, by determining the set position of each roll, each roll position when passing through the material to be corrected, the plate material of the target shape, the shape material , Pipes, wires, etc.

Once the stiffness matrix K _ij has been determined, as in the subsequent roll wear and roll change,
In a case where the origin of the roll setting position is assumed to have changed, by making each component of the stiffness matrix K _ij known, the unknown in Equation (10) becomes the origin correction amount g _i of the roll setting position and the experimental roll. different makes of n unknown constants α and β for each load pattern, whereas, since the n simultaneous equations is derived by a single experiment, immediately determine the origin correction amount g _i of the roll setting position by solving this Can also be modified.

[0033]

【Example】

(Embodiment 1) Next, an embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 7 is a side view showing an outline of a roller leveler without a backup roll used in the present embodiment. The roll diameter is 120 mm, the roll body length is 320 mm, and the roll pitch is 125 mm. It has four upper rolls and three lower rolls, and the upper rolls can be pushed independently.
Each roll has a load cell 10, and the load cell 10 measures each roll load. The upper and lower roll groups 3 and 4 are fixed to housings 5 and 6 of the roller leveler, respectively, and the housings 5 and 6 are connected to the housing posts 7. Since the roller leveler used in this embodiment is for correcting a plate material, the reference test piece 8 sandwiched between the upper and lower roll groups 3 and 4 has a thickness of 15 mm.
mm, a width of 250 mm, and a length of 500 mm were used.

Each work roll 1 is pushed in by using the roll pushing-in device 9 while holding the reference test piece 8 therebetween, thereby setting each roll set position s _i and each roll load P _i under 36 kinds of load patterns. Was measured. Reference specimen 8
The elastic deformation amount (bending) [delta] _i, was determined with the exception of the indefinite linear expression component by an elastic calculation. By substituting these into the equation (10), a simultaneous equation was established, and the rigidity was obtained by solving this simultaneous equation. Here, it is assumed that the deformation of the roller leveler is linear, but since the origin adjustment of the roll setting position was not accurately performed, not only the rigidity matrix K _ij as an index indicating the rigidity of the roller leveler, but also
The origin correction amount g _i of the roll setting position was also obtained.

The displacement of each roll predicted by using the rigidity matrix K _ij obtained by the present embodiment and the origin correction amount g _i of the roll set position, and the displacement of each roll obtained from the directly measured roll position. The comparison is shown in FIG. As a conventional example, it is calculated based on the idea that all lower rolls show an equal amount of displacement in proportion to the total roll load, and the idea that each lower roll shows its own displacement in proportion to each roll load. The displacement of each roll is also shown. According to the present invention, it can be seen that the displacement of each roll is accurately determined.

(Embodiment 2) In this embodiment, there is provided a roll set separately from the housing of the roller leveler, which contributes to the deformation of the material to be corrected. FIG. 7 shows a schematic view of the roller leveler used in this embodiment.
This is because the roller leveler main body 12 is the same as FIG.
The pressing roll 11 is provided on the front surface and the rear surface. As the reference test piece 8 sandwiched between the upper and lower roll groups 3 and 4 and the holding roll 11, a normal steel plate having a thickness of 15 mm, a width of 250 mm, and a length of 1200 mm was used.

Using the same method as in the first embodiment, the roll 1 incorporated in the roller leveler main body and the pressing roll 1
By calculating the stiffness matrix K _ij and the origin correction amount g _i of the roll set position for all the roll systems by adding 1, the displacement △ _{i of} each roll can be accurately obtained.

(Embodiment 3) This embodiment shows the result when the position of each roll is set after the displacement of each roll is accurately predicted by the method of the first embodiment. As a material to be corrected, width 250mm, thickness 10mm, length 1000mm
Was used. As a conventional example, the correction was performed under the empirical operating conditions used so far. FIG. 10 shows the relationship between the curvature of the material to be corrected at the front of the roller leveler and the curvature (residual curvature) of the material to be corrected at the rear of the roller leveler. According to the present invention, for the curvature amplitude at the front of the roller leveler, the curvature amplitude at the rear of the roller leveler converges to a narrow range,
It can be seen that the roll setting is optimal for the purpose of obtaining a flat plate even if the curvature of the material to be corrected in front of the roller leveler changes variously.

In the roller leveler used in this embodiment, the upper rolls could be pushed in independently of each other, so that the roll was set to a position where each roll was pushed in advance by an amount corresponding to the displacement of each roll in advance with respect to the optimum roll position. In the case of a roller leveler, where each roll was straightened, but each roll could not be pushed independently, it was possible to determine the optimal set position of each roll for the purpose of straightening after predicting the displacement of each roll. is there.

[0040]

According to the method of the present invention in which the stiffness of a roller leveler in which a plurality of rolls are arranged in a zigzag pattern is represented by a stiffness matrix, the displacement of each roll can be accurately predicted, and the roll setting accuracy is greatly increased. To improve. In addition, by using the stiffness obtained by this measurement method, by predicting the displacement of each roll, and determining the set position of each roll, the material to be corrected is flattened, or a desired warp or wave shape is given. It is possible to perform the correction under the optimum roll setting condition for the purpose of the correction.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a method for measuring the rigidity of a roller leveler according to the present invention.

FIG. 2 is a side view showing an outline of a roller leveler.

FIG. 3 is a conceptual diagram showing a relationship between a roll displacement, a set roll position, and an actual roll position.

FIG. 4 is a side view showing an outline of a roller leveler used in Examples 1 and 3 of the present invention.

FIG. 5 is a graph showing a prediction accuracy of the rigidity of the roller leveler according to the first embodiment of the present invention.

FIG. 6 is a side view showing an outline of an example of a roller leveler having a holding roll set separately from an integral housing.

FIG. 7 is a schematic diagram of a roller leveler used in the second embodiment of the present invention.

FIG. 8 is a drawing showing an example of a cross-sectional structure of a reference test piece and an aluminum layer sandwiched between upper and lower roll groups used for measuring a roll load of a roller leveler having no load cell in each roll in the present invention.

FIG. 9 is a drawing showing an example of a method of attaching a strain gauge to a reference test piece made of an elastic body sandwiched between upper and lower roll groups used for measuring a roll load of a roller leveler having no load cell in each roll in the present invention. It is.

FIG. 10 is a graph showing an effect when correction is performed by applying the prediction method according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Work roll 2 Back-up roll 3 Upper roll group 4 Lower roll group 5 Housing holding upper roll group 6 Housing holding lower roll group 7 Housing post 8 Reference test piece sandwiched between upper and lower roll groups 9 Roll pushing device 10 Load cell 11 Holding Roll 12 Roller Leveler Main Body 13 Housing Supporting Holding Roll 14 Strain Gauge

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Keishiro Ikeda 1 Nishi-nosu, Oita-shi, Oita Prefecture Nippon Steel Corporation Oita Works

Claims (6)

[Claims] 1. A roller leveler for arranging a plurality of rolls vertically in a zigzag pattern and repeatedly bending the rolls between the rolls to flatten the warp of the straightened material or to correct the wave shape. A load in the same direction as the straightening reaction force is applied to each roll, the displacement of each roll due to the load is measured, and the load and the data of the displacement are applied to each roll to change the distribution of the load applied to each roll. A method for measuring the stiffness of a roller leveler, comprising: obtaining a stiffness matrix of the roller leveler that associates a load and a displacement of each roll with a plurality of data of the load and the displacement obtained by the above procedure, with respect to the pattern. . 2. The method according to claim 1, wherein a stiffness matrix for obtaining the displacement of each roll from the load applied to each roll is obtained as an index of the stiffness of the roller leveler, and an origin correction amount of a set position of each roll is also obtained. The method for measuring the rigidity of the described roller leveler. 3. A reference test piece is sandwiched between an upper roll group and a lower roll group, a load is applied to the upper and lower rolls, and the reference test piece is regarded as a rigid body and its deformation is ignored, or the reference test is performed. 2. The method for measuring the rigidity of a roller leveler according to claim 1, wherein the piece is regarded as an elastic body, and the amount of elastic deformation thereof is corrected by elasticity calculation to determine the displacement of each roll under the load. 4. A load is applied to upper and lower rolls with a reference test piece interposed between the upper roll group and the lower roll group via a plastic body, and a dimensional index of an impression of the roll remaining on the plastic body is measured. 2. The method for measuring the rigidity of a roller leveler according to claim 1, wherein each roll load is determined based on the obtained values. 5. A load is applied to the upper and lower rolls with a reference test piece having a strain gauge attached between the upper roll group and the lower roll group, and each roll is subjected to elasticity calculation based on the strain measured by the strain gauge. The method for measuring the rigidity of a roller leveler according to claim 1, wherein the load is determined. 6. The displacement of each roll is predicted using the stiffness of the roller leveler measured by the method according to claim 1 and each roll load predicted in advance, and each roll is predicted based on the predicted displacement of each roll. A method for setting each roll position of the roller leveler, wherein the setting position is determined.