JP2019118917A - Bend correction method of shape steel and manufacturing method of shape steel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correct the bending of a shaped steel more accurately.
A method of correcting a bend in a web height direction of a shaped steel 10 having a web and a flange provided at an end in the height direction of the web, the bent shape obtained in the bend shape measuring step A rolling condition determination step of determining a rolling condition of the flange based on the curve is provided. The rolling condition determination step sets a plurality of sections in the longitudinal direction of the shaped steel, and determines the rolling condition of the flange based on the average value of the bending amount per unit length of the shaped steel in each section. The sum of the errors between the amount of bending per unit length at each position in the longitudinal direction of the section and the average value of the amounts of bending per unit length for each section is the smallest. Determine the length of each section so that
[Selected figure] Figure 1

Description

  The present invention relates to a method of correcting bending of a shape steel and a method of manufacturing a shape steel, and in particular, a method of correcting curvature of a H-shaped steel having a web and a flange provided at the end in the height direction of the web The present invention relates to an effective technique applicable to a method of manufacturing a shaped steel provided with a bending correction process for carrying out the present invention.

  As shown in FIG. 12, the H-shaped steel 100 as a shaped steel has a web 101 and two flanges 102 and 102 respectively provided on both sides in the height direction of the web 101. Such H-shaped steel is generally manufactured by universal rolling after heating a material to be rolled, such as a beam blank and a bloom, in a heating furnace. The universal rolling mill is a rolling mill equipped with a pair of upper and lower horizontal rolls and a pair of vertical rolls on the left and right, and the product of H-shaped steel is produced by pressing the web portion and the flange portion of the material to be rolled with these rolls. I will shape it.

  The formed H-section steel may be bent or warped due to the difference in the rolling reduction of the flange at the time of hot rolling or the temperature difference at the time of cooling. That is, when the H-shaped steel is rolled and manufactured, as shown in FIG. 12A, the H-shaped steel 100 is bent in the height direction of the web 101 (the amount of bending is indicated by a symbol δ) Alternatively, as shown in (a) of FIG. 13, warpage in the thickness direction of the web 101 (the amount of warpage is indicated by the symbol Sw) may occur in all or part of the longitudinal direction. Therefore, after the formed H-shaped steel is cooled by the cooling bed, the bending and the warping are corrected to a desired shape to make a product.

As a method of reducing such bending or warping, a method of adjusting rolling conditions in universal rolling is known. However, the occurrence of bending or warping of H-shaped steel is affected by unbalance in reduction in universal rolling, shape defects of the material to be rolled, and the like. That is, the occurrence of bending or warping of the H-shaped steel is affected by the universal rolling mill and various asymmetric rolling elements in the vertical and horizontal directions of the material to be rolled. Therefore, it is very difficult to finely adjust the rolling conditions of the universal rolling mill in response to all these factors.
Therefore, if bending or warping can not be prevented even by adjusting the rolling conditions, it is indispensable to correct the H-shaped steel with warm or cold after rolling. For such warpage, correction is usually performed online by a roller straightening machine, but since the correction load for bending is greater compared to warpage, it is possible to use an off-line in the refinement process. We are making corrections with a press.

As a method of press-correcting bending, there is known a method of performing three-point bending on an H-shaped steel by a press machine to correct it (see, for example, Patent Document 1). However, in three-point bending correction with a press machine, it is said that local bending of the front end of H-section steel is difficult to be corrected due to the mechanical restriction between the supporting points of bending (the pitch between the receiver and the latch). There has been a problem that the dimensions may fall out of the standard due to a change in the height of the web due to bending correction or the like. In addition, since the three-point bending correction by the press machine is performed in a state in which the conveyance of the H-shaped steel is stopped, there is a problem that the processing efficiency of the bending correction is low.
On the other hand, the method of correcting a curve is known by rolling the flange of the curvature radius direction radial direction of bending among two flanges which H section steel has (for example, refer patent document 2).

  In this method, a support roll for supporting the flanges from the side opposite to the web, and both flanges (here, right flange and left flange) respectively projecting from the height direction end of the web to both sides of the web Using a pair of correction rolls which press the flange having the above from the surface on the web side and press the right flange portion and the left flange portion between the support rolls respectively, Is a bending correction method in which the flange is pinched by setting the distance of at a predetermined interval or applying a predetermined rolling load.

  This rolling correction method can correct bending while conveying an H-section steel, and therefore is advantageous in terms of processing efficiency of bending correction as compared to the above-described press correction method. That is, if this rolling correction equipment is incorporated into the on-line process of the existing H-shaped steel manufacturing equipment and the bending of the H-shaped steel is corrected, material intake and discharge, and other incidental materials compared to the offline equipment. Handling can be omitted and lead time can be shortened.

  Moreover, patent document 3 is mentioned as a more specific method of this rolling correction method. This is the rolling of the flange based on the curve shape measurement step of obtaining the curve shape curve of the shape steel in the web height direction along the longitudinal direction of the steel plate and the curve shape curve obtained in the curve shape measurement step. A method of correcting bending of a shaped steel comprising: a rolling condition determining step of determining the condition; and a rolling correcting step of rolling the flange of the shaped steel over the longitudinal direction according to the rolling conditions determined by the rolling condition determined step. It is.

Then, in the step of determining the rolling conditions, the curve curve dividing step of dividing the obtained curve of curve amount into a plurality of unit regions in the longitudinal direction, and calculating the average value of the amount of curve per unit length in each unit region. The rolling conditions for each unit area in the longitudinal direction are determined from the relationship between the above average value in each unit area, the pre-set bending amount, and the rolling conditions for correcting the bending amount. And a unit area rolling condition determining step.
Also, with regard to this “multiple unit area division in the longitudinal direction”,
(A1): The difference between the maximum value and the minimum value of the amount of bending per unit length in each unit area is made to be equal to or less than a predetermined reference value.
(A2): Divide each unit area equally according to the product length,
Is disclosed.

Japanese Patent Application Publication No. 2008-030090 Tokuhei 2-50812 JP 2014-140898

In the conventional press correction method described above, the operator visually determines the position (hereinafter, also referred to as "correction position") and the correction amount to be subjected to the bending correction in the H-shaped steel. Therefore, there were cases where it was not possible to perform accurate and efficient bend correction.
In addition, in the rolling correction method disclosed in Patent Document 1 described above, the bending correction can be performed while conveying the H-shaped steel by rolling the flange on the inner side in the curvature radius direction of the bending. There is no specifically disclosed example as to how to control the amount of reduction of the correction roll in the above, and further devising is necessary for realizing curving according to this method.
On the other hand, in the rolling correction method disclosed in Patent Document 3, a plurality of sections are provided in the longitudinal direction of the product to be corrected, and the correction conditions, that is, the rolling conditions are determined according to the actual state (average value) of bending in each section. It was a decision, and it was an efficient technology to correct the bending.

However, regarding the correction section length,
(B1): When the difference between the maximum value and the minimum value of the amount of bending per unit length in each unit area is equal to or less than a predetermined reference value, the number of sections is very large depending on the form of bending. And the correction machine often can not make this setting.
(B2): Even when the unit areas are equally divided according to the product length, depending on the form of bending, the difference between the average value in each section and the actual amount of bending at that point is large, With the necessary correction conditions in the part, the case of making a distant correction frequently occurs, and the correction effect of bending can not be exhibited.
There was a problem that.
Then, this invention was made paying attention to the subject of the said prior art, and the objective of this invention is providing the technique which can perform bending correction of a shaped steel more correctly.

  In order to achieve the above object, according to one aspect of the present invention, there is provided a method of correcting bending of a shaped steel, comprising a web and a flange provided at an end in a height direction of the web in the height direction of the shaped steel. A method of correcting a bend, comprising: a bend shape measuring step of obtaining a bend shape curve per unit length in the web height direction of the shape steel along the longitudinal direction of the shape steel; The flange is rolled along the longitudinal direction of the section steel according to the rolling condition determination step of determining the rolling condition of the flange based on the obtained curved shape curve and the rolling condition determined by the rolling condition determination step And a rolling correction process. The rolling condition determination step sets a plurality of sections in the longitudinal direction of the section steel, and the rolling conditions of the flange based on the average value of the bending amount per unit length of the section steel in each section. For the length of each section, an average value of the amount of bending per unit length at each position in the longitudinal direction of the section steel and the amount of bending per unit length in each section The length of each section is determined so as to minimize the sum of errors between

In addition, according to one aspect of the present invention, there is provided a method of correcting a bend in a web in a height direction of a web having a web and a flange provided at an end of the web in the height direction. A bending shape measuring step for obtaining a bending shape curve per unit length in the web height direction of the shape steel in the longitudinal direction of the shape steel, and the bending shape curve obtained in the bending shape measurement process A rolling condition determination step of determining the rolling condition of the flange, and a rolling correction step of rolling the flange over the longitudinal direction of the section according to the rolling conditions determined by the rolling condition determination step; Prepare. The rolling condition determination step sets a plurality of sections in the longitudinal direction of the section steel, and the rolling conditions of the flange based on the average value of the bending amount per unit length of the section steel in each section. For the length of each section, an average value of the amount of bending per unit length at each position in the longitudinal direction of the section steel and the amount of bending per unit length in each section The length of each section is determined so that the sum of the errors between
Moreover, the manufacturing method of the section steel which concerns on 1 aspect of this invention is equipped with the bending correction process of enforcing the bending correction method of the said section steel.

  According to one aspect of the present invention, it is possible to correct the bending of the shaped steel more accurately.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows schematic structure of the section steel manufacturing equipment provided with the curve correction installation which enforces the curve correction method of H section steel which concerns on one Embodiment of this invention. The figure which shows schematic structure of a bending correction machine ((a) is a figure along the plane of H section steel, (b) is a figure along the cross section of H section steel). It is a figure which shows the curve shape pattern and correction range (rolling area | region) of H section steel. It is a figure for demonstrating the curve correction method of the shaped steel which concerns on one Embodiment of this invention, Comprising: The figure which shows an example of the curve shape which measured H section steel over the full length in the longitudinal direction with bending measuring apparatus (A) is a figure which shows the curve | deflection profile of the full length of H section steel, (b) is a figure which shows the curve | deflection amount per unit length. It is the figure which divided the curve of the amount curve of Drawing 4 (b) into a plurality of sections at the beginning. It is a figure which shows an example of the error area in the initial length of each area of FIG. It is a figure which shows an example of an error area at the time of optimizing the length of each area of FIG. It is a figure which shows a comparative example with respect to the Example of one Embodiment of this invention, Comprising: It is a figure which shows the curve distribution per unit length before correction | amendment, and the curve profile after correction. FIG. 7 shows an example of an embodiment of the present invention, showing the distribution of bends per unit length before correction and the bend profile after correction. It is a figure which shows the correction result of the Example of one Embodiment of this invention, and a comparative example. It is a figure for demonstrating the bending correction method of H section steel which concerns on other embodiment of this invention, Comprising: Bending per unit length which measured H section steel over the full length in the longitudinal direction with bending measurement apparatus It is a figure which shows the state which optimized the quantity and the length of each area. Diagrams for explaining the bending of H-section steel ((a) is a plan view showing bending in the height direction of the web, (b) is a sectional view along the height direction of the web, (c) is the web It is a top view which shows the curve in the height direction. The figure for demonstrating the curvature of H section steel ((a) is a side view which shows the curvature in the thickness direction of a web, (b) is sectional drawing along the thickness direction of a web).

Hereinafter, with reference to the drawings, a method of correcting bending of a shaped steel according to an embodiment of the present invention and a method of manufacturing a shaped steel provided with a bending correction process for implementing the method of correcting bending will be described. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiments of the invention, and the repetitive description thereof will be omitted.
Before describing the method of correcting bending of H-section steel according to one embodiment of the present invention, an H-shaped steel manufacturing facility (H-shaped steel manufacturing line) equipped with a bending correction facility for implementing the method of correcting bending will be described.

<H-shaped steel manufacturing facility>
As shown in FIG. 1, H-shaped steel manufacturing equipment (production line) 1 used for manufacturing H-shaped steel which is a shaped steel is a shape of H-shaped steel 10 by rolling a material to be rolled such as bloom or beam blank. The apparatus includes a rolling and forming facility 1A for forming into and a bending and straightening facility 1B for correcting the bending of the H-shaped steel 10 formed by the rolling and forming facility 1A. In the method of manufacturing the H-shaped steel 10, the H-shaped steel manufacturing facility 1 implements a rolling and forming process in the rolling and forming facility 1A, and performs a bending and correcting process in the bending and straightening facility 1B. That is, in the method of manufacturing H-shaped steel 10 according to one embodiment of the present invention, a rolling and forming step of rolling a material to be rolled and forming it into the shape of H-shaped steel 10 and H-shaped formed in this rolling and forming step And a step of correcting the bending of the steel 10. And in the bending correction process, the bending correction method of H section steel 10 concerning one embodiment of the present invention is carried out.

<Rolling and forming equipment>
The rolling and forming equipment 1A includes a continuous heating furnace, an oxide film removing device, a rough rolling mill, a tongue cut, an intermediate rolling mill, a finish rolling mill, a hot saw, a cooling bed (cooling bed), and the like. The H-shaped steel 10 formed by the rolling and forming equipment 1A is cooled by the cooling bed and then introduced from the rolling and forming equipment 1A to the bending straightening equipment 1B by the transfer line 9 of the H-shaped steel manufacturing equipment 1. Then, the H-shaped steel 10 is, for example, cold and bent and corrected into a product having a desired shape in the bending correction equipment 1B, and is then sent to the equipment on the downstream side by the conveyance line 9. As an intermediate rolling mill and a finishing rolling mill, for example, a universal rolling mill is used.

<Curve correction equipment>
The bending correction equipment 1B is a equipment for correcting the bending in the height direction of the web of the H-shaped steel 10 having a web as a shaped steel and a flange provided at the end in the height direction of the web, the H-shaped steel 10 is incorporated into the on-line process of the H-shaped steel manufacturing facility 1 that manufactures 10. That is, bending correction equipment 1B is disposed in series with other equipment involved in the manufacture of H-shaped steel 10.
Bending correction equipment 1B is a bending measuring device 2 for measuring the bending of H-section steel 10 which is formed by the former rolling forming equipment and corrects the bending, and the calculation processing on the measurement result of this bending measuring device 2 Arithmetic processing unit 4 and two bend correctors 3A for correcting the bending of the H-shaped steel 10 by rolling the flange 12 (see FIG. 2) of the H-shaped steel 10 based on the arithmetic processing result by the arithmetic processing unit 4 , 3B.

<Curve measurement device>
The type and measuring method of the bending measuring device 2 are not particularly limited. For example, the flange side (flange outer surface) opposite to the web 11 of the H-shaped steel 10 during conveyance of the H-shaped steel 10 or H-shaped It can carry out by measuring the distance to the flange outer surface or the flange inner surface with a laser range finder disposed to face the flange side (flange inner surface) on the web 11 side of the steel 10.
With the H-section steel 10 stopped on the transfer line 9, the laser range finder is run in the longitudinal direction of the H-section steel 10 while the laser range finder is disposed opposite to the flange outer surface or flange inner surface of the H-section steel 10 Thus, the distance from the laser distance meter to the flange outer surface or the flange inner surface along the longitudinal direction of the H-shaped steel 10 may be measured. In the bending measuring device 2, the longitudinal area where the H-shaped steel 10 is bent, the bending direction, and the amount of bending are measured.

Here, the “bending” in the present invention is, as described with reference to FIG. 12, in a section steel having a web and a flange provided at the end in the height direction of the web, in the height direction of the web. It means a curve. The bending amount δ of the total length L of the H-shaped steel (product) is represented as shown in FIG. 12 (a). The amount of bending δ ₀ per unit length of the product is expressed as shown in FIG. 12 (c). In the present specification, positive and negative signs are given depending on the direction of bending.
In addition, the bending that occurs in the H-section steel 10 has various patterns, for example, as shown in FIG. 12 (a), when bending in one direction substantially uniformly along the entire length L of the H-section steel, As shown in c), when the direction of bending changes in the longitudinal direction and becomes an S-curve, or in addition, bending occurs in only a part of the longitudinal direction (for example, only the end) There is a curved shape pattern such as the case.

<Curve Corrector>
The type and bending method of the bend straighteners 3A and 3B may be a straightener of the type in which the flange is rolled in the longitudinal direction of the H-shaped steel using a roll. That is, as shown in FIGS. 2 (a) and 2 (b), the bending straighteners 3A and 3B are disposed on the surface (flange outer surface) opposite to the surface of the flange 12 on the web 11 side. Are disposed opposite to the support roll 21 supporting the flange from the outer surface side and the surface (flange inner surface) of the flange 12 on the web 11 side, and are perpendicular to the height direction of the web 11 from the end in the height direction of the web 11 And a pair of straightening rolls 22 and 22 for pressing both flange portions (here, referred to as right flange portion and left flange portion) overhanging. By pressing the flange 12 on the inner side of the curvature radius of curvature (the left side flange in FIG. 2) with the support roll 21 and the straightening roll 22.22 and rolling under a predetermined rolling condition, the flange 12 on the inner side of the curvature radius of curvature. Is stretched so that the bend is corrected.

  One of the two bend straightening machines 3A and 3B performs rolling on one of the two flanges 12 and 12, and the other bend straightening machine 3B includes the other flange 12 Rolling. As described above, there are various patterns in the bending that occurs in the H-shaped steel 10, but if it is an equipment configuration combining two bending straightening machines 3A and 3B as in this embodiment, what kind of bending shape Even in the case of a pattern H-shaped steel, the bending can be corrected.

For example, in the case of an H-shaped steel curved in an arch shape (dish shape, inverted dish shape) as shown in FIGS. 3 (a) and 3 (b), two bending corrections are made regardless of the direction of the bending. It is possible to correct using either one of the machines 3A and 3B, and in the case of an S-shaped curved H-section steel as shown in FIG. 3 (c), both of the two bending straightening machines 3A and 3B are used. It can be corrected using
In addition, if there is a reversing mechanism that flips the H-shaped steel in the longitudinal direction or flips it back to the front and back in addition to the bend corrector, by adding the reverse according to the form of the bend, only one bend corrector is required. You can also

  The posture of the H-shaped steel 10 in the bending correction equipment 1B and the rolling and forming equipment 1A is not particularly limited, but the web 11 is horizontal and the flanges 12 and 12 are vertical because of the stability during transportation. It is preferable that the posture be taken (hereinafter sometimes referred to as “H posture”). Therefore, it is preferable from the viewpoint of the reliability as an on-line facility to roll in the H posture also at the time of bending correction. However, the web 11 may be vertical and the flanges 12 and 12 may be horizontal (so-called I posture).

<H-shaped steel correction method>
Next, a method of correcting the bending of the H-shaped steel 10 manufactured in the rolling and forming equipment 1A (rolling and forming process) on-line by using the bending and straightening equipment 1B (bending correction process) will be described.
According to an embodiment of the present invention, a method of correcting bending of an H-section steel is to obtain a bending shape curve per unit length in the web height direction of the H-section steel 10 along the longitudinal direction of the H-section steel 10. In accordance with the rolling conditions determined in the rolling condition determination step of determining the rolling conditions of the flange 12 based on the step and the curved shape curve obtained in the curved shape measurement step, the longitudinal length of the H-shaped steel 10 A rolling correction process is provided which rolls the flange 12 along the direction. And the rolling correction process which determines the rolling conditions of flange 12 sets a plurality of correction sections in the longitudinal direction of H-section steel 10, and average value of the amount of bending per unit length of H-section steel 10 in each section The rolling conditions of the flange 12 are determined based on

  Specifically, the H-shaped steel 10 cooled by the cooling bed of the rolling and forming equipment 1A is conveyed by the conveyance line 9 of the H-shaped steel manufacturing equipment 1 to the bending straightening equipment 1B in the refining process. The H-shaped steel 10 conveyed to the bending correction facility 1B is first sent to the bending measurement device 2 installed on the entrance side of the bending correction machine 3A. Then, the bend of the entire area in the longitudinal direction (full length) is measured by the bend measuring device 2, and the longitudinal area where the bend is occurring, the direction of the bend, and the amount of bend are measured. Then, the arithmetic processing unit 4 performs arithmetic processing on the measurement result, and the arithmetic processing unit 4 sends the result of the arithmetic processing to the bending correctors 3A and 3B. The details of the arithmetic processing in the arithmetic processing unit 4 will be described later. The bending measurement and the bending correction are usually performed on the entire length of the H-section steel 10, but may be performed on only a part of the longitudinal direction (for example, only the end).

  When the measurement of the bending of the H-shaped steel 10 is finished, the H-shaped steel 10 is sent to the bending correction machine 3A, 3B, and one flange 12 is subjected to rolling in the bending correction machine 3A, and then the bending correction machine 3B The other flange 12 is rolled at. The rolling is performed under the correction conditions set based on the result of the arithmetic processing. That is, the longitudinal direction area where rolling is performed and the rolling conditions are successively changed according to the longitudinal direction area where the bending occurs, the bending direction, and the bending amount. Thus, rolling is not applied to longitudinal regions where no bending occurs. Further, even if bending occurs, rolling is not applied to the radially outer flange 12 of the bending.

The H-shaped steel 10 thus bent and corrected into a desired shaped product is sent to a subsequent process, for example, a roller correction process and an inspection process for correcting a warp.
As described above, the bending correction equipment 1B of this embodiment can be installed in the existing H-shaped steel manufacturing equipment 1, and can be incorporated into the on-line process of the H-shaped steel manufacturing equipment 1 to make the H-shaped steel 10 online. Since it is possible to correct the bend, the bend of the H-section steel 10 can be corrected efficiently. Moreover, compared with the case of correcting bending off-line, it is possible to omit loading and unloading of material (H-shaped steel) and material handling of other accessories (for example, crane operation) and shorten lead time to product shipment. it can. In addition, reliance associated with material handling can be reduced. Further, the setting of the correction position and the correction amount (rolling conditions) is not based on the judgment result of the bending amount by visual observation, but the correction position and the correction amount are determined based on the bending measurement using the bending measuring device 2 The accuracy and efficiency of bend correction are excellent.

<Method of Determining Correction Condition Based on Curved Shape>
Next, a method of determining the correction (rolling) condition by the arithmetic processing unit 4 based on the measurement result of the bending shape will be described.
FIG. 4 is a view showing an example of the bending shape in the longitudinal direction of the H-section steel 10 measured by the bending measurement device 2. (a) shows a bending profile of the full length of the H-section steel 10, (b) shows a unit length The amount of bending per unit time (in this example, the amount of bending per meter) is shown.
When the bending of the H-shaped steel 10 is measured by the bending measuring device 2, the longitudinal direction area where bending occurs, the bending direction, and the amount of bending are measured, and when this is processed by the processing unit 4, it is shown in FIG. The bend shape curve shown and the bend amount curve shown in FIG. 4 (b) are obtained. The curved shape curve is a curve obtained by copying the shape of the H-shaped steel 10, so-called profile data. In the example of FIG. 4 (a), the full length of the H-section steel 10 is 16 m, and the amount of bending in the full length is 24.5 mm. In addition, since an abnormal value etc. may be measured in the bending measurement by the bending measurement apparatus 2, it is preferable to obtain a bending shape curve, after removing the abnormal value etc. as needed.

  In the bend correction of this embodiment, a plurality of correction sections are set in the longitudinal direction of the H-shaped steel 10 with respect to the H-shaped steel 10 as a product to be corrected. In the example shown in FIG. 5, six sections are set. Then, for each section, an average value of the amount of bending per unit length in the section is determined. Based on the average value of the amount of bending per unit length, a correction target load for each section is calculated, and the condition is transferred to the bending straighteners 3A and 3B. It is possible to determine the correction target load by previously defining the relational expression of the correction load to the bending amount according to the size of the H-shaped steel to be corrected and the steel type as product information. The bending correctors 3A and 3B receive this condition and perform correction according to the target load for each section while tracking the longitudinal position of the H-shaped steel (shaped steel product) 10 being conveyed.

  Here, when the length of each correction section is set as in the example of FIG. 5, for a section where the change in the amount of bend per unit length is sharp, the average of the amount of bend per unit length in that section A large error occurs between the value and each individual value (the actual amount of bending). When the correction load is set from the average value in this section, a part where the correction load is excessive and a part where the correction load is too small are generated, and as a result, the correction of the bend may not be successfully performed.

As a way to avoid this problem
(C1): Increase the number of correction sections set in the longitudinal direction (ultimately, change the correction load in real time according to the bending of each part),
(C2): As disclosed in Japanese Patent Laid-Open No. 2014-140898, where the difference between the maximum value and the minimum value of the amount of bending per unit length in each unit area (that is, each section) exceeds the reference value Divide the interval,
The method is called.
However, in order to realize the above method (C1), it is necessary to set many correction sections in the longitudinal direction. And in order to realize this, a command (target load) is finely transmitted from the arithmetic processing unit to the straightening machine, and the straightening machine needs to receive this at any time to set the load. As a result, the equipment becomes very complicated and the amount of capital investment increases.

Further, in the method (C2) above, the number of sections to be divided changes depending on the form of bending, but depending on the form of bending, the number of sections that can be set by equipment may exceed the number of sections. There was a similar problem.
Therefore, in this embodiment, the correction section length is set as follows, for example.
First, as shown in FIG. 5, a plurality of correction sections are set in the longitudinal direction of the H-section steel 10. In the example of FIG. 5, the number of correction sections is six.
Next, the average value of the amount of bending per unit length in each section is calculated. Then, as shown in FIG. 6, the difference between the average value of the amount of bending per unit length calculated in each section and the amount of bending at each point is an error, and the error over the entire length of the H-section steel 10 The sum is obtained as an error area S. The shaded area in FIG.

The error area S can be expressed as a function having the lengths x1, x2,..., X6 of the sections as variables, as shown in the following equation (1).
S = f (x1, x2, ..., x6) ... (1)
That is, x1, x2,... X6 where the error area S is minimum are the lengths of the appropriate sections, and the values of x1, x2,. It can be determined by utilizing an algorithm such as a sudden drop method.

When using the steepest descent method, change amount of error area S when x1 is changed minutely is obtained as ∂S / ∂ × 1 and then change amount of error area S when x2 is changed minutely The variation amount of the error area S when x3 to x6 are minutely changed is determined sequentially as ∂S / ∂ × 2 to 6 similarly. The section lengths x1, x2,..., X6 are changed in accordance with the magnitudes of these partial derivatives.
In the initial section length of FIG. 6, the average value of errors (error area S / total section length) was about 0.16 mm. On the other hand, the average value of the errors could be reduced to about 0.12 mm by optimizing the section length as shown in FIG.

<Effect of one embodiment>
As mentioned above, in the correction method of H section steel 10 concerning one embodiment of the present invention, the amount of bending per unit length in each position of the longitudinal direction of H section steel 10, and unit length in each section Since the length of each section is determined so that the sum of the errors with the average value of the bending amount per hit is minimized, the average value of the errors can be reduced as shown in FIGS. 6 to 7. Therefore, the above-mentioned conventional method (C1) of "increase the number of correction sections set in the longitudinal direction" or the above-mentioned (C2) of "the maximum value of the amount of bending per unit length in each unit area" Compared with the method of "dividing the section where the difference with the minimum value exceeds the reference value", the average value of the amount of bending per unit length of the section also in the section where the change of the bending amount per unit length is sharp In addition, since the difference between the individual bending amounts can be reduced, the bending correction of the H-section steel 10 can be performed more accurately according to the actual state of the bending.

In addition, since the average value of errors can be reduced by optimizing the length of the pre-set correction section without intentionally increasing the number of correction sections, it is possible to correct the bending of H-section steel 10 as the actual state of bending. It can be done more efficiently accordingly.
In addition, since it is not necessary to increase the number of correction sections, it is possible to suppress the complication of the bend correction equipment.
Therefore, according to the method of correcting the H-shaped steel 10 according to the embodiment of the present invention, the bending correction of the H-shaped steel 10 can be performed more accurately and efficiently with a simple bending correction equipment.

Further, the method of correcting the bending of the H-shaped steel 10 according to the embodiment of the present invention is implemented in the bending correcting step of the method of manufacturing the H-shaped steel 10. Therefore, according to the method of manufacturing H-section steel 10 according to one embodiment of the present invention, since bending correction of H-section steel 10 can be performed more accurately and efficiently in the bending correction process, the yield of H-section steel 10 is obtained. (Product acquisition rate) can be improved.
In addition, when the length of the correction | amendment area is extremely short, the bending correction effect by rolling of bending correction machines 3A, 3B may become unable to be exhibited. Therefore, it is preferable to determine in advance the allowable value of the length at which the bend correction effect can be exhibited, and to determine the length of each section so as to be equal to or greater than the predetermined allowable value. The allowable value of the length is, for example, about 1000 mm, although it depends on the performance of the bending straighteners 3A and 3B.

(Example)
Below, the Example and comparative example of this embodiment are shown. In addition, this embodiment is not limited to the following example.
In this embodiment, the bending correction of the H-shaped steel in the above-described embodiment is performed for the H-shaped steel (nominal size H900 × 300 × 16 × 28, length 12 m) in which bending larger than the allowable value occurred during rolling. Corrected the bend according to the method. In this example, the number of correction sections was six, and the steepest descent method was used to determine the optimum length of each section length (conforming example). Further, in the comparative example, the correction was performed for the case where the six correction section lengths were fixed at equal intervals. The results of the distribution of bending per unit length before correction, the correction section, and the bending profile before and after correction are shown in FIG. 8 (comparative example) and FIG. 9 (example).

Both products of the example and the comparative example had an S-curved shape before correction, but in the example, the H-shaped steel can be corrected to a bending amount less than the tolerance, and it passed. On the other hand, in the comparative example, even after the correction, the bend more than the allowable value remained and became a rejection.
Next, with respect to H-shaped steels of the same size, bending correction was performed on 10 H-shaped steels in each of the example and the comparative example, and the results were compared. This is shown in FIG. In FIG. 10, the horizontal axis is the amount of bending before correction, and the vertical axis is the amount of bending after correction. Moreover, "(circle)" is data of an Example, "(square)" is data of a comparative example.
As shown in FIG. 10, in all of the ten samples in the example, the post-correction bending became less than the allowable value. On the other hand, in the comparative example, the bending after correction exceeded the allowable value in 5 out of 10, and these products were rejected.
From the above, the effects of the present invention are clear.

In the above embodiments and examples, the sum of the errors between the amount of bending per unit length at each position in the longitudinal direction of the section steel and the average value of the amounts of bending per unit length in each section is The case where the length of each section is determined so as to be the minimum has been described. However, calculation of the section length does not necessarily have to determine the section length at which the error is minimized. For example, in the process of calculation in which the tolerance of the error is set to 0.12 mm / m and the section length is changed, if this error becomes the tolerance, the correction condition is determined by each section length at that time You may That is, the sum of errors between the amount of bending per unit length at each position in the longitudinal direction of H-section steel 10 and the average value of the amounts of bending per unit length in each section is equal to or less than a preset allowable value As such, determine the length of this interval.
Also in this case, it is preferable to determine in advance the allowable value of the length at which the bend correction effect can be exhibited, and to determine the length of each section so as to be equal to or greater than the predetermined allowable value.

(Other embodiments)
In the above-described one embodiment and example, the sum of the errors between the amount of bending per unit length at each position in the longitudinal direction of the section steel and the average value of the amounts of bending per unit length in each section is minimum As described above, the case where the length of each section is determined is described. As a method of performing this more simply, there is also a method of setting a point at which the bending direction per unit length changes as a section division point as in this embodiment. For example, in the case of a bending distribution per unit length as shown in FIG. 11, a position of 6120 mm in the longitudinal direction in which the bending direction changes is taken as a section dividing point (point indicated by an arrow). Then, the front side of this division point is divided into a predetermined number of correction sections (three sections in the example of FIG. 11), and the sections of the three sections on the front side are the lengths of the sections in the same manner as FIG. Decide. And each section length is set up by the same method also about the back side. In the calculation of the section length, it is not necessary to obtain the section length at which the error is minimized. In the process of calculation in which the tolerance of the error is determined and the section length is changed, if this error becomes the tolerance, the correction condition may be determined by each section length at that time.

As mentioned above, although this invention was concretely demonstrated based on the said embodiment and Example, this invention is not limited to the said embodiment and Example, A various change is possible in the range which does not deviate from the summary. Of course.
For example, the size of the H-section steel to which the present invention can be applied is not particularly limited, and the present invention can be applied to any size H-section steel such as large or small. In addition, although the above-described embodiment and examples correct the bending of the H-shaped steel 10 formed by a rolling mill (for example, a universal rolling mill), the H cross-sectional shape can be obtained by welding a flange and a web. It is also applicable to bending correction of welded H-section steels.

  In the above-described embodiments and examples, although the method of correcting bending of shaped steel has been described by taking H-shaped steel as an example, shaped steel having a web and a flange provided at the end in the height direction of the web Therefore, the present invention can be applied, for example, to T-shaped steel. However, T-shaped steel is provided with a flange only at one end in the height direction of the web, and the present invention is to correct the bend by rolling the flange by rolling the inside flange in the curvature radius direction of the bend. Therefore, in the case of T-section steel, it is applicable only when the side with a flange is inside the curvature radius of curvature.

DESCRIPTION OF SYMBOLS 1 ... H-shaped steel manufacturing equipment 1A ... rolling shaping installation 1B ... bending correction apparatus 2 ... bending measurement apparatus 3A, 3B ... bending correction machine 4 ... arithmetic processing apparatus 10 ... H type steel 11 ... web 12 ... flange 21 ... support roll 22 ... Correction roll

Claims (5)

A method of correcting bending in a web height direction of a shaped steel having a web and a flange provided at a height end of the web, the method comprising:
A bending shape measuring step of obtaining a bending shape curve per unit length in the web height direction of the section steel in the longitudinal direction of the section steel;
A rolling condition determination step of determining rolling conditions of the flange based on the curved shape curve obtained in the curved shape measurement step;
And a rolling correction step of rolling the flange in the longitudinal direction of the shaped steel in accordance with the rolling conditions determined by the rolling condition determination step,
The rolling condition determination process is
A plurality of sections are set in the longitudinal direction of the section steel, and the rolling condition of the flange is determined based on the average value of the bending amount per unit length of the section steel in each section.
The total sum of the errors between the amount of bending per unit length at each position in the longitudinal direction of the section and the average value of the amounts of bending per unit length for the length of each section is minimum A method of correcting bending of a shaped steel, comprising determining the length of each section to be   2. The method according to claim 1, wherein the length of each section is determined to be equal to or greater than a predetermined allowable length. A method of correcting bending in a web height direction of a shaped steel having a web and a flange provided at a height end of the web, the method comprising:
A bending shape measuring step of obtaining a bending shape curve per unit length in the web height direction of the section steel in the longitudinal direction of the section steel;
A rolling condition determination step of determining rolling conditions of the flange based on the curved shape curve obtained in the curved shape measurement step;
And a rolling correction step of rolling the flange in the longitudinal direction of the shaped steel in accordance with the rolling conditions determined by the rolling condition determination step,
The rolling condition determination process is
A plurality of sections are set in the longitudinal direction of the section steel, and the rolling condition of the flange is determined based on the average value of the bending amount per unit length of the section steel in each section.
For the length of each section, the sum of the errors between the amount of bending per unit length at each position in the longitudinal direction of the section and the average value of the amounts of bending per unit length in each section is acceptable A method of correcting bending of a section steel, wherein the length of each section is determined so as to be equal to or less than a value.   The method according to claim 3, wherein the length of each of the sections is determined to be equal to or more than an allowable length.   A method for producing a shaped steel, comprising a bend correction step of performing the method for correcting the bend of the shaped steel according to any one of claims 1 to 4.

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