JP6287868B2 - Straightening device for shape steel and method for producing shape steel - Google Patents

Description

  The present invention relates to a shape steel straightening device that can be suitably used for a shape steel including a web and a flange projecting from at least one end in the height direction of the web, such as an H-shaped steel and a T-shaped steel, and a straightening. The present invention relates to a method for producing a shape steel suitable for producing this type of shape steel.

Shaped steel with flanges, such as H-shaped steel and T-shaped steel, are manufactured by welding assembly and hot rolling of steel sheets, but due to non-uniform heating, cooling, and plastic deformation in the manufacturing process. In some cases, the whole or part of the longitudinal direction is bent or warped, and a straight product may not be obtained.
The bending and warping will be described by taking the H-shaped steel as an example. The bending refers to the bending of the H-shaped steel 100 in the height direction of the web 101 along the length direction of the H-shaped steel 100 as shown in FIG. Tell the state. In the example of FIG. 3, a bend of δ per length L occurs on the left flange 102 side in the figure.

Further, as shown in FIG. 4, the warp is a state in which there is a curvature S of the H-section steel 100 in the thickness direction (flange 102 width direction) of the web 101 along the length direction of the H-section steel 100. Say.
In addition, a defective product having a twist in which bending and warping are combined may occur. In order to remove such bends and warpage and make a straight product, cold correction is generally performed before product shipment.

As a method of straightening the shape steel, for example, a method of applying a bending stress to the shape steel using a press described in Patent Document 1, for example, a plurality of rollers arranged in a zigzag pattern described in Patent Document 2 A roller straightening method is generally used in which the web is crushed down.
However, although patent document 1 can correct | amend the bending of a shape steel effectively, after selecting the longitudinal direction position to which the shape steel is rolled down according to the situation of a bending, it reduces and corrects with an appropriate pressure. There is a need. Moreover, since Patent Document 1 often requires multiple times of reduction for correction, there is a problem that the time required for correction is long.

  Further, Patent Document 2 is a steel-efficient straightening method capable of removing warping of various sizes with a short time required for straightening. However, Patent Document 2 has a problem that correction ability is low with respect to bending. Further, Patent Document 2 discloses a roller straightening machine in which not only a horizontal roll but also a heel roll is installed, but even if a heel roll is added, it cannot be said that the bending straightening ability of the roller straightening machine is sufficient.

On the other hand, for example, a method described in Patent Document 3 is known as a method for correcting a shape steel having high bending correction efficiency and excellent processing ability.
The straightening method of the shape steel described in Patent Document 3 includes a support roll that presses the flange from the surface on the side opposite to the web, and a right that projects from both ends of the web in the height direction to both sides of the web. This is a bending correction method using a pair of straightening rolls that press the flange and the left flange from the surface on the web side and rolling the flange by applying a predetermined rolling force to the support roll and the pair of straightening rolls.

Since this patent document 3 can correct | amend, conveying the local bending of the shape steel shape, it is advantageous at the point of the processing efficiency of correction.
However, in the method of straightening the shape steel of Patent Document 3, the pair of straightening rolls pressing the web side surfaces (inner surfaces) of the right flange and the left flange are separated from the web in order to avoid interference with the web. As a result, a portion that is rolled with a straightening roll and a portion that is not rolled are generated on the inner surfaces of the right flange and the left flange, and a step is generated at the boundary between them, which is problematic in terms of the quality of the surface shape of the shaped steel.

Here, it is conceivable to prevent a step from occurring on the inner surfaces of the right flange and the left flange by rounding the outer periphery of the axial ends of the pair of straightening rolls.
However, the inventors have repeatedly investigated changes in the amount of reduction during straightening of the shape steel and generation of a step on the inner surface of the flange. As a result, a practical arc corresponding to the roll dimension is formed on the outer periphery of the axial end of the pair of straightening rolls. It was found that even when the radius is rounded, a step is likely to occur as the rolling reduction increases. Therefore, if the amount of reduction is made small in order to prevent the occurrence of a level difference, when the bending of the shape steel is large, the correction ability is insufficient and the bending cannot be sufficiently removed.

JP 2008-030090 A Japanese Patent Application Laid-Open No. H8-174069 JP2013-248640A

  Therefore, the present invention has been made paying attention to the above-mentioned unsolved problems of the conventional example, and can correct the shape steel efficiently, and even if the amount of reduction increases, the surface of the flange of the shape steel It is an object of the present invention to provide a shape steel straightening device and a method for producing a shape steel that can obtain a high-quality shape steel without any step difference.

In order to achieve the above object, a straightening device for structural steel according to an aspect of the present invention is used for a structural steel including a web and a flange projecting from at least one end in the height direction of the web. It is a shape steel straightening device that straightens the bending of the shape steel web in the height direction by rolling the flange while being conveyed cold. This device is rolled while pressing the flange between a support roll that is in contact with the outer surface of the flange and a correction roll that is in contact with the inner surface of the flange, and the roll end of the correction roll is on the inner surface of the flange. the end portion outer peripheral located, have a taper roll diameter decreases closer to the roll end, when the angle is theta relative to the axis of rotation of the straightening roll taper formed on the end outer circumference, 1 ° ≦ θ ≦ 3 The range was °.

Moreover, the manufacturing method of the shape steel which concerns on 1 aspect of this invention is used for the shape steel provided with the web and the flange which protrudes from the at least one end in the height direction of a web, conveying shape steel coldly. This is a method of manufacturing a shaped steel that corrects bending in the height direction of the web by rolling a flange. Then, rolling is performed while pressing the flange between the support roll that is in contact with the outer surface of the flange and the correction roll that is in contact with the inner surface of the flange, and the roll end of the correction roll is on the inner surface of the flange. The outer periphery of the end portion has a taper in which the roll diameter decreases as it approaches the end of the roll, and the angle of the taper formed on the outer periphery of the end portion with respect to the rotation axis of the straightening roll is 1 ° ≦ θ The range was ≦ 3 °.

  According to the shape steel straightening device and shape steel manufacturing method according to the present invention, the shape steel can be straightened efficiently, and even if the amount of reduction increases, a step is generated on the surface of the shape steel flange. High quality steel can be obtained.

It is a front view of the straightening apparatus of the rolling system which is one embodiment of the straightening apparatus for shape steel according to one aspect of the present invention. It is a figure which shows the shape of a pair of correction | amendment roll which comprises the straightening apparatus for steel shapes which concerns on this invention. It is a figure explaining the "bending" by rolling manufacture of a section steel, The figure (a) is a top view, (b) is a cross-sectional view. It is a figure explaining "warp" by rolling manufacture of a section steel, the figure (a) is a top view and (b) is a transverse section.

Hereinafter, modes for carrying out the present invention (hereinafter referred to as embodiments) will be described with reference to the drawings as appropriate.
The straightening device of the first embodiment shown in FIG. 1 corrects the bending in the height direction of the web by rolling while conveying the shape steel in a cold state.
The straightening apparatus 10 of 1st Embodiment is an example applied to the H-section steel 100 as a shape steel which correct | amends bending by rolling a flange. In this example, correction is performed with the H-section steel 100 cut into a product length, and the H-section steel 100 is placed on a plurality of table rollers (not shown) provided along the longitudinal direction. Then, it is transported in the longitudinal direction of the H-section steel 100 by a drive device (not shown).

  The H-section steel 100 includes a web 101 and two flanges 102 and 102 provided on both sides of the web 101 in the height direction. Each of the flanges 102 and 102 has a left flange portion 102a and a right flange portion 102b that protrude from the left and right sides in the thickness direction of the web 101 and form a pair. In other words, in this specification, the left and right flange portions 102a and 102b are referred to with respect to one flange 102 (the lower flange in the figure).

As shown in the figure, the straightening device 10 includes a roll 1 (hereinafter referred to as a support roll 1) opposed to the outer surface of the flange 102 (the surface on the side without the web 102c) and the inner surface of the flange 102 (the web 102c). 2 and 3 (hereinafter referred to as a pair of straightening rolls 2 and 3).
The support roll 1 is pivotally supported by a chock (not shown) with the axis extending in the horizontal direction in FIG. 1 as a rotation axis. In FIG. 1, the support roll 1 supports the lower flange 102 from the outer surface 102 c opposite to the web 101.

The pair of straightening rolls 2 and 3 are disposed so as to face the left and right flange portions 102a and 102b from the surface on the web 101 side with respect to the lower flange 102 in the figure. The straightening rolls 2 and 3 have the same configuration.
That is, each of the straightening rolls 2 and 3 is pivoted at the tips of the respective chocks 22 and 32 through the support shafts 21 and 31 with the shafts extending in the horizontal direction in FIG. It is supported.

Each chock 22, 32 is supported by a support mechanism whose base end is not shown so as to be slidable in a direction facing the support roll 1. And a pair of correction | amendment rolls 2 and 3 apply | subject pressing force as shown by the arrow in a figure by a pair of pressing force control means provided for every correction | amendment roll 2 and 3, The left and right flange parts 102a, 102b is clamped between the support rolls 1.
Then, the flange 102 is rolled by rotating the support roll 1 while sandwiching the left and right flange portions 102 a and 102 b between the straightening rolls 2 and 3 and the support roll 1.

Here, as shown in FIG. 2, the width of the support roll 1 (the length in the roll body length direction) is set to a value larger than the flange width of the H-section steel 100 to be straightened. Therefore, the end portion of the support roll 1 is not located on the flange surface. On the other hand, the side of the correction rolls 2 and 3 facing the web 101 is positioned on the surface (inner surface) of the flange 102.
In this embodiment, it is a roll which an edge part is located on the flange surface among the rolls which roll a flange.

As shown in FIG. 2, the pair of straightening rolls 2 and 3 includes an end outer periphery of the straightening roll 2 that contacts the inner surface 102a1 of the left flange portion 102a and a straightening roll that contacts the inner surface 102b1 of the right flange portion 102b. 3, tapers 28 and 38 having a uniform angle θ are formed so that the roll diameter decreases toward the end of the roll (hereinafter, θ is referred to as a taper angle).
The taper angle θ of the tapers 28 and 38 is inclined in the range of 1 ° ≦ θ ≦ 3 ° with respect to the rotation axes P1 and P2 of the pair of correction rolls 2 and 3.
The outer periphery other than the outer periphery of the end portion provided with the tapers 28 and 38 has a flat shape in which the roll diameter is made equal along the axial direction, and the taper roll width L of each taper 28 and 38 is determined by the left and right flanges. The width is designed so as not to affect the rolling of the portions 102a and 102b.

Next, a straightening device 10 according to the first embodiment, a method of manufacturing a shape steel that uses the same to correct the bending of the shape steel, and the function and effect thereof will be described.
Then, when manufacturing the shape steel by correcting the bending of the shape steel with the straightening device 10 of the first embodiment, first, only the bent H-shape steel 100 after cooling to a predetermined temperature in the cooling bed. Extract. Then, the bending of the H-shaped steel 100 in the height direction of the web 101 is measured on the entry side of the straightening device 10, and the measured values (the occurrence position of the bending and the bending amount δ (see FIG. 3A) ), The rolling force (rolling load) applied to the correction rolls 2 and 3 is set to a predetermined value set in advance.

  Next, the H-section steel 100 is placed on a plurality of table rollers that guide the straightening device 10. Then, the flange 102 (the lower side in FIG. 1) inside the bending direction is supported by the support roll 1 from the outer surface 102c opposite to the web 101, and the left and right flange portions 102a and 102b are supported on the web 101 side. The H-section steel 100 is driven by a driving device that rotationally drives the support roll 1 while pressing the support roll 1 in a direction opposite to the support roll 1 by pressing with a pair of straightening rolls 2 and 3 from the surface. The bending of the H-section steel 100 is corrected by rolling the flange while transporting in the longitudinal direction cold.

In the manufacturing method of the H-section steel 100 using the straightening device 10 of the first embodiment, the pressing force for pinching with the pair of straightening rolls 2 and 3 is bent in the height direction of the web 101 (FIG. 3 ( Since the control is individually performed so as to maintain the predetermined value set in accordance with the bending amount δ) of a), it is possible to reduce the reduction rate difference and the elongation rate difference between the left and right flange portions 102a and 102b that occur during rolling.
When the bending is large, the rolling reduction ratios of the left and right flange portions 102a and 102b are increased so as to increase the stretch amount. Here, in the conventional straightening method (for example, Patent Document 3), when the rolling reduction is increased, the inner surface 102a1 and 102b1 of the left and right flange portions 102a and 102b are generated with a portion that is rolled with a straightening roll and a portion that is not rolled. There is a step at the boundary.

  However, in the first embodiment, the taper 28 has a roll diameter that decreases toward the end of the pair of straightening rolls 2 and 3 that are in contact with the inner surfaces 102a1 and 102b1 of the left and right flange portions 102a and 102b. 38, the contact angle with respect to the left and right flange portions 102a and 102b is kept constant even when the rolling reduction is increased, so that the occurrence of a step on the inner surfaces 102a1 and 102b1 can be suppressed. it can.

  Further, when the taper angle θ of the tapers 28 and 38 provided on the outer periphery of the ends of the pair of straightening rolls 2 and 3 is less than 1 °, the taper roll width L becomes long and the left and right flange portions 102a and 102b are rolled. As a result, the width of the stretched portion is reduced and the correction effect is reduced. On the other hand, when the taper angle θ exceeds 3 °, the boundary between the indented portion and the non-indented portion tends to occur as a line extending in the length direction of the H-section steel 100.

Therefore, by setting the taper angle θ provided on the outer periphery of the end portions of the tapers 28, 38 to 1 ° ≦ θ ≦ 3 °, the correction effect by the pair of correction rolls 2, 3 can be enhanced, and the inner surfaces 102a1, A boundary line or the like is unlikely to occur between the lower portion of 102b1 and the non-lower portion.
As described above, the method for manufacturing a shaped steel using the straightening device 10 of the first embodiment can efficiently straighten the H-section steel 100, and even if the reduction amount increases, No step is generated on the inner surfaces 102a1 and 102b1 of the flange portions 102a and 102b, and a high-quality shaped steel can be obtained.
Note that the reduction ratio of the flange portion necessary for correcting the bending is often sufficient with a reduction ratio of 1% or less in view of the general bending size of the hot-rolled H-section steel.

Further, the taper roll width L of the tapers 28 and 38 is such that the surfaces of the left and right flange portions 102a and 102b are within the taper range even when rolling is performed at the maximum value Δh-max of the reduction amount of the flange 102 when correcting the bending. You just have to decide to stay. Specifically, the minimum value L-min of the taper roll width L is expressed by the following equation (1) using the taper angle θ and the maximum flange reduction amount Δh-max.
L-min = Δh-max / tan θ (1)

  The actual taper roll width L needs to be larger than the minimum value L-min, but if the taper roll width L is excessively large, the flatness of the pair of straightening rolls 2 and 3 for rolling the left and right flange portions 102a and 102b is flat. Since the width of the portion becomes small, it is desirable to design the smallest width that can tolerate variations in operation. Specifically, the taper roll width L is preferably the minimum value L-min + 50 mm or less.

In addition, the shape steel straightening device and the method for manufacturing the shape steel according to the present invention are not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention.
In the above-described embodiment, the roll end portions forming the tapers 28 and 38 are each one of the end portions of the correction rolls 2 and 3 on the side facing the web 101. For example, the correction roll 2 has a wide flange width. , 3 may be formed on both surfaces of the flange 102 when both ends thereof are positioned on the surface of the flange 102. At this time, the taper angles at both ends may be set individually. Furthermore, when rolling the shape steel whose flange width is wider than the width of the support roll 1, a taper may be formed at one end or both ends of the support roll 1.

In the first embodiment, the H-shaped steel 100 has been described as an example of the shape steel. However, the present invention is not limited to this, and the present invention includes a web and a flange protruding from at least one end in the height direction of the web. If it is a shape steel provided with, it is applicable to various shape steels.
Further, in the first embodiment of FIG. 1, the bending correction of the so-called I-shaped H-section steel 100 in which the pair of flanges 102 are vertically positioned has been described, but the so-called H-position in which the pair of flanges 102 are arranged in the horizontal direction. When the straightening of the H-shaped steel 100 is performed, the apparatus can be applied even to an apparatus in which the support roll 1 and the pair of straightening rolls 2 and 3 are rotated by 90 °.

The shape steel was manufactured by correcting the bending of the shape steel with the straightening device 10 shown in FIG.
The taper angle θ of the tapers 28 and 38 of the pair of straightening rolls 2 and 3 was set to 2 °.
The bending of the H-section steel 100 having a height of the web 101 of 600 mm, a width of the flange 102 of 300 mm, a web thickness of 12 mm, and a flange thickness of 22 mm was performed.
The overall length of this H-shaped steel 100 is 8m, and the entire bend is almost the same shape. The bend amount at the total length of 8m is 18mm, and the dimension crossing exceeds ± 8mm (1mm per 1m in length). It was. In addition, the standard value of the yield strength of this H-section steel 100 is 320 MPa.

And the rolling load was set to 115 tons as bending correction conditions, and the bending correction of the H-section steel 100 was performed.
The H-shaped steel 100 after bending correction has a total length of bending reduced to 1 mm, and an H-shaped steel having a bending amount within the dimension crossing could be manufactured.
Further, although the inner surfaces 102a1 and 102b1 of the H-shaped steel 100 after bending correction were observed, the boundary between the indented portion and the non-indented portion could not be clearly distinguished, and no step was generated on the inner surfaces 102a1 and 102b1.
In addition, when the flange was cut from the H-shaped steel 100 after straightening and the profile of the straightened inner surface of the flange was measured, an inclination of about 1.5 ° was formed at both ends of the portion rolled by straightening. However, both ends of the slope were smooth profiles, and it was confirmed that there were no steps.

  Next, as a comparative example, an H-section steel was manufactured by correcting the bending of the H-section steel with a pair of straightening rolls having an arcuate round end at the end of the roll as in the past. The radius of the round arc was 40 mm, and the bending of an H-section steel having the same dimensions and standard as the H-section steel 100 described above and a total length of 19 mm was corrected. And in order to give the rolling reduction of the same flange as the H-section steel 100, it similarly corrected with the rolling load of 115 tons. As a result, it was possible to correct the bend in a straight state, but the boundary line and step of the rounded roll end were formed on the flange inner surface after the bend correction, and it is necessary to scrape the step. Became.

Furthermore, as another comparative example, the straightening angle of the edge of the pair of straightening rolls is 4 [deg.] And the total bending amount is 16 mm. Was done. As a result, the amount of bending after correction could be reduced to 2 mm in total length. However, when the inner surface of the flange after bending correction was observed, the boundary line at the end of the roll remained so that it could be visually confirmed, and it was necessary to scrape the boundary line.
As described above, when the bending of the section steel is corrected by the straightening device 10 according to the present invention, no step or boundary line is formed on the inner surfaces 102a1 and 102b1 of the H-shaped steel 100 after the bending correction, and a good surface shape is maintained. Therefore, the bending of the shape steel can be effectively reduced.

DESCRIPTION OF SYMBOLS 1 ... Support roll 2, 3 ... Straightening roll 10 ... Straightening device 21, 31 ... Support shaft 22, 32 ... Chock 28, 38 ... Taper 100 ... H-section steel 101 ... Web 102 ... Flange 102a ... Left flange part 102b ... Right flange Portion 102a1 ... Inner surface 102b1 of the left flange ... Inner surface 102c of the right flange ... Outer surface L of the flange ... Taper roll widths P1 and P2 ... Rotation axis θ of the correction roll ... Taper angle (angle)

Claims (2)

It is used for a structural steel comprising a web and a flange extending from at least one end in the height direction of the web, and the flange of the web is rolled by rolling the flange while transporting the structural steel in a cold state. A shape steel straightening device that corrects bending in the height direction,
The support roll is in contact with the outer surface of the flange, and the correction roll is in contact with the inner surface of the flange, and is rolled while pressing the flange, and the roll end of the correction roll is the inner surface of the flange. the end portion outer peripheral located above, have a taper roll diameter decreases closer to the roll end,
The shape steel straightening device , wherein θ is an angle of the taper formed on the outer periphery of the end portion with respect to the rotation axis of the straightening roll, and the range is 1 ° ≦ θ ≦ 3 ° . Used in a structural steel having a web and a flange extending from at least one end in the height direction of the web, and rolling the flange while conveying the structural steel in the cold direction in the height direction of the web A method of manufacturing a shape steel that corrects the bending of
The support roll that is in contact with the outer surface of the flange and the correction roll that is in contact with the inner surface of the flange are rolled while pressing the flange. On the outer periphery of the end portion located above, there is a taper that the roll diameter becomes smaller as it approaches the roll end portion,
A method for manufacturing a shaped steel, wherein the angle of the taper formed on the outer periphery of the end portion with respect to the rotation axis of the straightening roll is θ, and the range is 1 ° ≦ θ ≦ 3 °.

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