JPH10263705A - Roll straightening method for wide-flange shape steel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a straightening method for a wide-flange shape steel capable of simply constructing a reduction correcting control system by following the same plastic deforming history even in the case of changing the size and the kind of steel. SOLUTION: A web crack generating limit road Pc is obtained from the cross section shape data of the wide flange shape steel to be a straightening object (step S3), the optimal roll pitch L* not generating the web crack is calculated based on this (step S4), the rolling reduction applying to the flange is determined based on the basic reduction pattern of respective straightening rolls set so that the optimal roll pitch and the camber quantity after straightening become zero (step S5), the rolling reduction of the web equivalent to the determined rolling reduction applying to the flange is determined using the rolling reduction ration of the web and the flange obtained from the straightening load and the cross section shape of the wide flange shape steel to be straightened, i.e., the flange reduction ratio function α (step S7), and reduction control of the straightening roll is executed with the determined rolling reduction of the web (step S8, S9).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roller straightening method for an H-section steel, in which a plurality of straightening rolls are arranged at a variable pitch to correct an H-section steel to be straightened.

[0002]

2. Description of the Related Art In general, roller straightening of an H-section steel is performed using a roll pitch variable type roller straightening machine in which a plurality of rolls are arranged in a zigzag pattern and the roll pitch can be changed. Since the sagging occurs when the rolling is performed, the web is reduced and the flange is indirectly elastically and plastically deformed to perform the correction.

[0003] There are two correction conditions for a variable roll pitch roller straightening machine: roll pitch and roll reduction. Each of these parameters does not mean that can be set independently, it neither correctable. Therefore when having it is both related affect straightening effect is in fact well known to empirically On the contrary, this is a difficult point of correction.

[0004] Conventional methods for straightening rollers for H-section steel include:
For example, there is one described in JP-A-54-57460. In this conventional example, the bending curvature to be given to the material to be straightened at each roller position is determined from the relationship between the bending distribution of the H-section steel before straightening, that is, the initial warpage amount and the bending distribution allowed for the product after straightening, that is, the allowable warpage tolerance. From the relationship between the web height elongation amount and the processing curvature using the roll pitch ratio as a parameter, a correction roller interval, that is, a roll pitch capable of keeping the cross-sectional dimensional accuracy within a target range is estimated, and the processing curvature and the estimated correction are estimated. The position of the correction roller is determined by obtaining the set coordinates of the correction roller from the roller interval.

[0005]

However, in the above-described conventional H-section roller straightening method, the index for determining the roll pitch is the web height increase occurring during straightening. The web height increase amount uses the ratio of the front-stage roll pitch and the rear-stage roll pitch as a parameter and is associated with the processing curvature.Therefore, in the roller straightening machine, the size change naturally occurs, but the steel type change also occurs. In many cases, when the steel type is changed, the yield stress changes even for the same size, so the straightening curvature is different under the same straightening conditions, and conversely, when the same working curvature is applied, the straightening load increases as the yield stress increases. However, there is an unsolved problem that the shape of the product deteriorates due to the increase in the web height and the elongation of the web.

Further, in the conventional example, the plastic deformation history of the flange at the time of straightening is determined from the amount of reduction and the roll pitch, and a different processing curvature is determined for each size. There is also an unsolved problem that the plastic deformation history determined from the balance with the rolling reduction differs. Here, an error always occurs between the model and the actual straightening machine. In such a case, a method is generally adopted in which the amount of warpage is reduced to zero by adjusting an appropriate roll reduction amount, but the plastic deformation history is different at the time of warpage adjustment which cannot be avoided in an actual line. Since the influence coefficient of each roll differs for each size, there is an unsolved problem that the adjustment requires a lot of effort.

Therefore, the present invention has been made by focusing on the unsolved problems of the above-mentioned conventional example. Even when the size or the steel type is changed, the same plastic deformation history is traced.
It is an object of the present invention to provide a roller straightening method for an H-section steel in which the rolling reduction control system can be easily constructed.

[0008]

According to a first aspect of the present invention, there is provided a roller straightening method for an H-section steel, wherein a plurality of straightening rolls are arranged at a variable pitch. In a method of straightening an H-section steel to be straightened, the straightening roller is set in such a manner that an optimum roll pitch is determined from a web cracking limit and the straightening roll pitch is set. The reduction amount to be applied to the flange is determined according to the basic reduction pattern of each correction roll set so that the amount of warpage becomes zero, and the reduction control of the correction roll is performed based on the determined reduction amount. And

According to a second aspect of the present invention, there is provided a roller straightening method for an H-section steel, wherein the web of the H-section steel is pressed down by a roller straightening machine having a plurality of straightening rollers arranged at variable pitches. In the method of straightening a H-section steel roller by performing elasto-plastic deformation on the H-shaped steel, an optimum roll pitch is determined from a web cracking limit, the pitch of the straightening roll is set, and then straightening is performed from the determined roll pitch. The amount of reduction to be applied to the flange is determined according to the basic reduction pattern of each correction roll set so that the amount of warpage becomes zero, and the reduction amount of the web corresponding to the determined amount of reduction to be applied to the flange is determined by the correction load and the correction target H. Determined using the ratio of the reduction amount of the web and flange obtained from the cross-sectional shape of the shape steel,
The straightening roll is controlled by the determined web reduction amount.

[0010] Further, in the roller straightening method for an H-section steel according to claim 3, the H-section steel web is reduced by a roller straightening machine in which a plurality of straightening rolls are arranged at a variable pitch. In the method of straightening a H-section steel roller by performing elasto-plastic deformation on the H-shaped steel, an optimum roll pitch is determined from a web cracking limit, the pitch of the straightening roll is set, and then straightening is performed from the determined roll pitch. The reduction amount to be applied to the flange is determined in accordance with the basic reduction pattern of each correction roll set so that the amount of warpage becomes zero, and the reduction amount of the web corresponding to the determined reduction amount to be applied to the flange is determined by the correction load and the correction target. It is determined on the basis of the difference in the amount of reduction between the web and the flange obtained from the cross-sectional shape of the H-section steel, and the straightening roll is controlled with the determined amount of reduction of the web. It is a symptom.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram showing a roller straightening machine 2 for straightening an H-section steel 1. The roller straightening machine 2 has nine straightening rolls R ₁ to 9 in which the roller pitch is adjustable and arranged in a staggered manner. R ₉ , the roll pitch L between these straightening rolls R _{1 to} R ₉ is adjusted to a uniform pitch by the roll pitch adjusting device RP, and an odd-numbered straightening roll R _j among the straightening rolls R _{1 to} R _9. (J = 1,
Reduction ratio of 3, 5, 7, 9) is adjusted by the rolling reduction adjusting device PA _j consists of an electric motor or the like.

Here, the H-section steel 1 to be corrected is shown in FIG.
As shown in FIG. 2, a web 1a extending in the left-right direction and left and right flanges 1b, 1c extending vertically at both ends of the web 1a are formed in an H shape.
Flange width B, web thickness t _W , flange thickness t
_F and corner radius are represented as r.

[0013] Then, Each of the respective rolling reduction adjusting device PA _j, is controlled by a composed controller 3 by a microcomputer or the like. An input device 4 such as a keyboard is connected to the controller 3 and a CRT
A display device 5 such as a display is connected, and a predetermined calculation process is performed based on the cross-sectional shape and standard of the H-section steel input from the input device 4 to prevent web cracking of each of the straightening rolls R _{1 to} R _9. In addition to calculating the optimum roll pitch, the optimum roll amount to be applied to the flange is calculated according to the basic rolling pattern of each straightening roll set so that the amount of warpage after straightening becomes zero based on the optimum roll pitch. The web reduction amount is calculated, and a value obtained by adding the relief amount of the straightening roll to the calculated web reduction amount is used as the web reduction amount. Based on this, each of the reduction amount adjusting devices _PAj is controlled.

Here, the correction principle will be described below.
First, the elastic limit curvature κ _y when the flange end reaches the yield stress is represented by the following equation (1).

Κ _y = 2σ _y / (E · B) (1) where σ _y is the yield stress, E is the Young's modulus, and B is the flange width. Similarly, the elastic limit bending moment M _y when the flange end reaches the yield stress can be expressed by the following equation (2).

M _y = Z · σ _y = (1/3) t _F B ² σ _y (2) where Z is a section modulus and t _F is a flange thickness. Further, the curvature κ and the bending moment M are respectively referred to as elastic limit curvature κ.
_The curvature coefficient λ and the moment coefficient μ, which are obtained by dividing _y by the elastic limit bending moment M _y and are dimensionless, are defined by the following equations (3) and (4).

Λ = κ / κ _y (3) μ = M / M _y (4) The amount of warpage after correction is determined by the curvature coefficient λ and the moment coefficient μ. Is a deformation history expressed by the following relationship.
An example of the relationship between the curvature coefficient λ and the moment coefficient μ representing this deformation history is represented by simulation as shown in FIG. That is, the starting point is the curvature coefficient λ ₁ and the moment coefficient M ₁ at the straightening roll R ₁ on the entry side,
From now on, it is converged so that the curvature coefficient λ gradually becomes zero while drawing a hysteresis curve, and is determined from the curvature coefficient λ ₈ and the moment coefficient M ₈ at the straightening roll R ₈ just before the final straightening roll R ₉ on the delivery side. Final straightening roll R ₉
Curvature factor lambda ₉ becomes less bending amount allowed in.

Therefore, in order to reduce the amount of warpage after correction to "0", it is important to select a basic rolling pattern in consideration of the deformation history. On the other hand, the amount of warpage on the entry side usually varies during rolling and cooling in the preceding process, and the rolling pattern is not adjusted according to the curvature on the entry side, and the variation Δκ _{0 of the} entry-side warpage. On the other hand, it is possible to reduce the variation of the outgoing-side warpage by giving a large curvature in the first bending as shown in FIG.

A roll straightening machine 1 for giving elasto-plastic deformation
In the case of, the same bending process as when corrected with the flange width B ₀ , the yield stress σ _y0 , the roll pitch L ₀ and the reduction amount δ ₀ when the basic rolling pattern is determined is obtained at a different roll pitch L ′. For this purpose, the roll reduction amount δ ′ of each roll is determined according to the similarity rule of the roll straightening machine 1 by the elastic limit curvature κ _y expressed by the above equation (1) and the elastic limit bending moment M expressed by the above equation (2). _{When y} is set, the operation of the following equation (5) should be performed.

Δ ′ = (κ _y ′ / κ _y0 ) (L ′ / L ₀ ) ² δ ₀ (5) Therefore, the warpage amount after fixing the roll pitch for a certain cross-sectional series and correcting it By determining experimentally the basic rolling pattern representing the amount of reduction of each of the straightening rolls R _{1 to} R ₉ such that “0” becomes “0”, the amount of reduction given to the flange even when the series is changed to a cross-sectional series is determined. If determined according to the above equation (5), the same bending process, that is, substantially the same deformation history can be performed, and the warpage after correction can be set to “0”.

[0021] Then, correction load P _i of each roll R _i when the roll pitches was L (i = 1,2, ...... 9 ) can be expressed by the following equation (6). _{P i = (M y / L} ) p i ............ (6) where, p _i is a dimensionless constant determined during basic pressure pattern selected represents the basic load pattern, in particular the following equation (7) It is represented by a function as shown in

P _i = p _i [(δ ₁ / κ _y L ² ),..., (Δ _k / κ _y L ² )] (7) where k ≦ i. On the other hand, the critical load P of cracks generated at the roots of the web 1a and the flanges 1b and 1c by the load applied to the web 1a during straightening through various H-sections.
_C was determined by experiment. Limit expression prepared from the experimental results is expressed by the following equation (8), the crack critical load P _C is H
Depends on the series section of the section steel, qualitatively the web thickness B
Is a limit load P _C as higher corner radius r is large large increases.

P _C = f (t _W , H, t _F , B, r) (8) At this time, in order to prevent the web from cracking, the maximum value P _MAX of the straightening load is as follows: limit load P _C as represented by) formula
Must be:

[0024] determined according to _{P MAX = (M y / L} ) p MAX ≦ P C ............ (9) Then, the equation (9) below (10) the roll pitch L ^* so as to satisfy the condition of Formula I do.

[0025] ^{_{L * = M y · p MAX}} / P C ............ (10) As a result, the above-described on the basis of the roll pitch L ^* between the straightening rolls (5) below (11) corresponding to the formula calculating an optimum reduction ratio [delta] _Fj 'providing the flange of each straightening roll R _j in accordance.

Δ _Fj ′ = (κ _y ′ / κ _y0 ) (L ^* / L ₀ ) ² δ _0j (11) By the way, the amount of reduction given by the above equation (11) is
b, 1c, not the reduction applied to the web 1a, but the straightening δ _{Wj applied} to the web 1a and the reduction δ _{Fj applied} to the flange in the straightening of the H-section steel, which _{lowers the} web 1a. Does not match.

Therefore, the relationship between the two reduction amounts is expressed by the following (12)
As shown in the equation, the reduction ratio function α was obtained, and the reduction ratio function α was obtained as a function of the series cross-sectional shape of the H-section steel and the correction load P as shown in the following equation (13).

Δ _Wj ′ = (1 / α) δ _Fj ′ (12) α = α (t _W , H, t _F , B, r, P) (13) The operation of the above embodiment will be described with reference to a flowchart of FIG.

First, a reference flange width B (for example, 300 mm) and a flange thickness t _F (for example, 15 mm) are set in advance.
The basic H-section steel having a yield stress σ _y0 (for example, 30 kg / mm ² ) is corrected by the roller straightening machine 2 in which the reference roll pitch L ₀ is adjusted to, for example, 1400 mm, for example, by following the deformation history of FIG. There was corrected so that "0", to measure the reduction amount [delta] _0j of each straightening roll R _j at this time, as shown in FIG. 7, at the same time, dimensionless constant p of each straightening roll R _j
The basic load pattern _i is calculated by performing the above-described equation (7), the maximum value of the calculated dimensionless constants p _i is set as p _MAX , and the elastic limit is determined according to the above equation (1). The curvature κ _y0 is calculated, and these are calculated by the controller 3
Is stored in the memory 6 inside.

In this state, the arithmetic processing shown in FIG. 5 is executed. First, in step S1, the sectional shape data of the H-section steel as the material to be corrected and the steel type data thereof are input. Here, the web height H, flange width B, web thickness t _W , flange thickness t _F and corner radius r of the H-section steel are set as the sectional shape data, and the yield stress σ of the H-section steel is set as the steel type data. _y is set.

Then, the process proceeds to step S2, where the equations (1) and (2) are calculated based on the input shape data and steel type data, and the elastic limit curvature κ _y ′ and the elastic limit bending moment are calculated. calculates M _y ', stores them in a predetermined storage area of the memory 6.

[0032] Then, the processing proceeds to step S3, and calculates the web cracking limit load P _C by performing the calculation of the empirical formula of the equation (8) based on the cross-sectional shape data. Next, the process proceeds to step S4 to calculate the optimum roll pitch L ^* that does not cause web cracking by performing the calculation of the above equation (10).

[0033] Then, the processing proceeds to step S5, the elastic limit curvature kappa _y0 basic H-shaped steel, which is stored in the memory 6, the roll pitch L _0, the corrected target reduction amount [delta] _0j of each straightening roll R _j The equation (11) is calculated based on the elastic limit curvature κ _y ′ of the H-section steel and the optimum roll pitch L ^*, and the flange reduction amount δ _Fj ′ given to the flanges 1b and 1c in each straightening roll _Rj is calculated. calculate.

Then, the process proceeds to step S6 to calculate the flange reduction ratio function α by performing the calculation of the above equation (12) based on the sectional shape data of the H-section steel to be corrected and the correction load P. Then, the process proceeds to step S7, where the calculation of the above equation (13) is performed based on the flange reduction amount δ _Fj ′ calculated in step S5 and the flange reduction ratio function α, so that the optimum web reduction amount given to the web 1a is obtained. δ _Wj ′
Then, the process proceeds to step S8, and the following (1)
4) Calculate the straightening roll R _i a correction web rolling reduction and the corrected backlash or roll supporting members corrective roller displacement caused by the rigidity of the straightening machine such as a bearing for supporting [delta] _Wj ^* according formula.

Δ _Wj ^* = β · δ _Wj '+ γ (14) where β is a coefficient related to the rigidity of the roller straightening machine 2 and the straightening roll, and γ is a constant related to backlash. Is determined by the characteristics of

[0036] Then, the processing proceeds to step S9, and outputs the calculated optimum roll pitch L ^* a roll pitch adjustment device RP, and outputs the corrected web rolling reduction [delta] _Wj ^* the rolling reduction adjusting device PA _j.

[0037] Thus, the roller straightener 2 roll pitch corresponding to H-beams to be corrected target is adjusted to the optimum roll pitch L ^*, reduction rate of each straightening roll R _j correction reduction amount [delta] _Wj ^* It is adjusted to.

[0038] At this time, the optimum roll pitch L ^*, calculates the web cracking limit load P _C on the basis of the limit equation determined experimentally, roll pitch L ^* so as not to exceed this web crack critical load P _C Therefore, it is possible to reliably prevent the occurrence of web cracks during straightening by the roller straightening machine 2 and to set the optimum roll pitch L ^* and elastic limit curvature of the set H-section steel to be straightened. κ _y ′
When reduction ratio [delta] _Fi that gives the flange of each straightening roll R _j in accordance similarity law of roller straightening machine based on the roll pitch L ₀ and elastic limit curvature kappa _y0 of the basic pressure pattern preset basic H-shaped steel ' Roller straightening machine 2
Is substantially the same as the deformation history of the basic H-shaped steel shown in FIG. 3, and stable warpage correction can be performed on the H-shaped steel having any steel type and cross-sectional shape.

[0039] Moreover, the straightening rollers R _j web rolling reduction [delta] _Wj flange from rolling reduction [delta] _Fi 'given to the H-beam to be corrected object by using the reduction ratio function α based on the cross-sectional shape data and correcting load determined ′, So that
From the amount of reduction δ _Fi ′ applied to the flange, the amount of web reduction δ _Wj ′
It is possible to accurately and easily carry out the conversion to, and to perform more stable warpage correction.

Further, for the change of the size and the steel type of the H-section steel, the roll pitch is determined based on the web crack limit load, and the reduction amount applied to the flange is determined based on the determined roll pitch and the basic reduction pattern. Therefore, a reduction amount correction control system can be easily constructed.

The warping before and after the straightening of the H-shaped steel of standard size H300 × 300 × 10/15 and H900 × 300 × 16/28 using the straightening method of the first embodiment. The measurement results of the amounts are shown in FIG. The basic rolling pattern used at this time is, as shown in FIG.
Roll pitch L is 14 for H-section steel with flange width of 300mm.
This is a rolling pattern when the warping amount after correction is set to be 0 mm as “0 mm”, and the reduction amount of the _first correction roll R ₁ is 4 mm, and the reduction amount of the third correction roll R ₃ is 1 .8Mm, fifth straightening roll rolling reduction R ₅ is 0.8 mm, amount of reduction seventh straightening roll R ₇ is 0.5 mm, amount of reduction ninth straightening roll R ₉ is 0m
m.

During the straightening of these H-section steels, no web cracks occurred, and the amount of warpage after straightening was -20 m as shown in FIG.
Even when the variation was within the range of m to +20 mm, the amount of warpage after the correction was all within the allowable range of -4 mm to +4 mm, and a good correction result could be obtained.

Next, a second embodiment of the present invention will be described with reference to FIG. The second embodiment is different from the first embodiment in that the conversion from the reduction amount δ _Fj ′ given to the flange to the web reduction amount δ _Wj ′ is performed by using the flange relief function δ instead of using the flange reduction ratio function α. _This is converted using a.

In the second embodiment, the controller 3
Then, as shown in FIG. 8, in the first embodiment described above,
The processing of steps S6 and S7 in FIG.
Based on the sectional shape data of the section steel and the correction load P, the following (1)
Calculate equation 5) to calculate the amount of flange relief, ie, flange pressure.
Flange relief function δ representing the difference between the amount of reduction and the amount of web reduction _a
Is calculated in step S11, and
Released flange relief function δ_aAnd calculated in step S5
Reduction δ given to the flange_Fj′ And the following (1
6) Perform the calculation of the equation to obtain the web draft δ_Wj′
Except for replacing with step S12,
5 are executed, and the processes corresponding to FIG.
One step number is added, and the detailed description is omitted.
You.

Δ_a= Δ_a(T_W, H, t_F, B, r, P) ... (15) δ_wj'= Δ_Fj'+ Δ_a (16) According to the second embodiment, the first embodiment described above is used.
Web crack limit load P_CLow so as not to exceed
L pitch L^*Is set, the correction by the roller straightening machine 2 is performed.
Ensure that web breaks do not occur in the middle
And at the same time the set H-shaped steel
Suitable roll pitch L^*And elastic limit curvature κ _y'And preset
Pitch of basic H-section steel in basic rolling pattern
L₀And elastic limit curvature κ_y0And based on roller straightening machine
Each straightening roll R according to the similarity rule_jPressure applied to flange
Lower volume δ_Fi′ Is determined, so the deformed
The history is almost the same as the deformation history of the basic H-section steel shown in FIG.
Stable warpage for H-beams of any steel type and cross-section
Correction becomes possible.

Thereafter, the calculated reduction applied to the flange is
Quantity δ_Fj′ Indicates the cross-sectional shape data of the H-section steel to be straightened and straightening
Flange clearance relation indicating the amount of flange clearance based on the load P
Number δ _aAnd the web draft δ_Wj′
Reduction amount given to flange δ_Fi′ To web reduction δ_Wj′
Conversion to accurate and easy, and more stable warpage correction
Positive can be done.

Using the second embodiment, a standard size
H300 × 300 × 10/15 (σ _y= 30kg / mm^Two)
And H900 × 300 × 16/28 (σ_y= 30kg / mm^Two)
Of the amount of warpage before and after straightening when straightening H-section steel
FIG. 9 shows the results. Basic rolling pattern used at this time
Used the basic rolling pattern shown in FIG.

During the straightening of these H-section steels, no web crack was generated at all, and the warpage after straightening was -20 m as shown in FIG.
Even if it varies within the range of m to +20 mm, the warpage after straightening is all within the allowable range of -4 mm to +4 mm for all H-beams having different yield stresses, and a good straightening result can be obtained. Was.

In the first and second embodiments, the case where the roller straightening machine 2 has nine straightening rolls has been described. However, the present invention is not limited to this. Needless to say, the present invention can also be applied to a roller straightening machine having the same.

[0050]

As described above, according to the first aspect of the present invention, the optimum roll pitch is determined from the web cracking limit, the pitch of the straightening roll is set, and the straightened roll pitch is determined from the determined roll pitch. Since the amount of warping applied to the flange is determined in accordance with the basic rolling pattern of each straightening roll set so that the amount of warpage of the straightening roll becomes zero, the reduction roll of the straightening roll is controlled based on the determined amount of rolling. The roll pitch is set so as not to exceed the limit load, so that it is possible to reliably prevent the occurrence of web cracks during straightening by the roller straightening machine, and to set the H-shape to be straightened. Based on the optimum roll pitch of the steel and the basic rolling pattern of the basic H-section steel, the amount of reduction to be applied to the flange of each straightening roll is determined according to the similar rule of the roller straightening machine. As a result, the deformation history of the roller straightening machine is almost the same as the deformation history of the basic H-shaped steel, enabling stable warpage correction of H-shaped steel of any steel type and cross-section without depending on the operator. Moreover, since the rolling amount correction control system for this only needs to determine the roll pitch based on the web crack limit load and determine the rolling amount to be applied to the flange based on the determined roll pitch and the basic rolling pattern, it is simple. The effect that it can be constructed in is obtained.

According to the second aspect of the present invention, the optimum roll pitch is determined from the web crack occurrence limit, and the pitch of the straightening roll is set. Then, from the determined roll pitch, the amount of warpage after straightening is reduced to zero. The reduction amount to be applied to the flange is determined in accordance with the basic reduction pattern of each correction roll set to be as follows, and the reduction amount of the web corresponding to the determined reduction amount to be applied to the flange is determined from the correction load and the sectional shape of the H-shaped steel to be corrected. The reduction amount of the straightening roll is determined by using the ratio of the reduction amount of the web and the flange, and the reduction amount of the straightening roll is controlled by the determined reduction amount of the web. Thus, the effect of accurately and easily performing the conversion into the web reduction amount can be obtained, and more stable warpage correction can be performed.

Further, according to the third aspect of the invention, the pitch of the straightening roll is set by obtaining the optimum roll pitch from the web cracking limit, and the warpage after straightening is determined to be zero from the determined roll pitch. Determine the amount of reduction given to the flange according to the basic reduction pattern of each straightening roll set to be, the web reduction amount corresponding to the determined amount of reduction given to the flange straightening load, the cross-sectional shape of the H-shaped steel to be corrected and It is determined based on the difference between the reduction amount of the web and the flange obtained from the correction load, and the reduction roll of the correction roll is controlled by the determined reduction amount of the web, in addition to the effect of the invention of claim 1, The effect of accurately and easily converting the amount of reduction applied to the flange to the amount of reduction of the web, and thereby performing more stable warpage correction can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a sectional view showing a sectional shape of an H-section steel.

FIG. 3 is an explanatory diagram showing a deformation history represented by a relationship between a curvature coefficient and a moment coefficient at the time of correction.

FIG. 4 is an explanatory diagram illustrating a relationship between a curvature coefficient and a moment coefficient for explaining a decrease in the amount of warpage due to a first large bending with respect to the incoming side warpage.

FIG. 5 is a flowchart illustrating an example of a correction processing procedure in a controller.

FIG. 6 shows H corrected by the correction method of the first embodiment.
It is explanatory drawing which shows the amount of curvature before and after straightening of a shape steel.

FIG. 7 is an explanatory diagram showing a basic rolling pattern used for straightening the H-section steel of FIG. 6;

FIG. 8 is a flowchart illustrating an example of a correction processing procedure in a controller according to the second embodiment of the present invention.

FIG. 9 is an explanatory diagram showing the amount of warpage of an H-shaped steel straightened by the straightening method according to the second embodiment before and after straightening.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 H-section steel 2 Roller straightening machine R _{1 to} R ₉ Straightening roll RP Roll pitch adjusting device PA _j Reduction amount adjusting device 3 Controller

Claims (3)

[Claims] 1. A method for correcting an H-shaped steel to be corrected by a roller straightening machine having a plurality of straightening rolls arranged at variable pitches, wherein the optimum roll is selected from the limit of web cracking. Determine the pitch of the straightening roll to determine the pitch, then determine the amount of rolling given to the flange according to the basic rolling pattern of each straightening roll set so that the amount of warpage after straightening from the determined roll pitch is zero. A method for straightening an H-section steel roller, wherein the straightening roll is controlled to be reduced based on the determined amount of reduction. 2. An H-shaped steel having a plurality of straightening rolls arranged at variable pitches, wherein a web of the H-shaped steel is pressed down to apply elasto-plastic deformation to a flange to perform the straightening. In the roller straightening method, the optimum roll pitch is determined from the web crack occurrence limit, the pitch of the straightening roll is set, and then the basis of each straightening roll set so that the amount of warpage after straightening from the determined roll pitch becomes zero. The amount of reduction to be applied to the flange is determined according to the reduction pattern, and the reduction amount of the web corresponding to the determined amount of reduction to be applied to the flange is determined by using the correction load, the ratio of the reduction amount of the web and the flange obtained from the sectional shape of the H-shaped steel to be corrected. And decide
A method for straightening a roller of an H-section steel, wherein the straightening roll is controlled to be reduced with the determined web reduction amount. 3. An H-shape steel having a plurality of straightening rolls arranged at variable pitches, wherein the H-shape steel is straightened by rolling down an H-shape web to apply elasto-plastic deformation to a flange. In the roller straightening method, the optimum roll pitch is determined from the web crack occurrence limit, the pitch of the straightening roll is set, and then the basis of each straightening roll set so that the amount of warpage after straightening from the determined roll pitch becomes zero. Determine the amount of reduction to be applied to the flange according to the reduction pattern, and correct the web reduction amount corresponding to the determined amount of reduction to be applied to the flange, and the difference between the reduction amount of the web and the flange determined from the cross-sectional shape of the H-shaped steel to be corrected. A method for straightening a roller of an H-section steel, wherein the straightening roll is reduced with the determined web reduction amount.