JP2013248640A - Bend straightening apparatus for shape steel and method of straightening bend of shape steel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of straightening bend of a shape steel and a straightening apparatus for a shape steel by which even if there is difference in plate thickness between right and left flanges when web height-direction bend of the shape steel is straightened by rolling while the shape steel is conveyed in cold, degradation in other forms (camber, twist or the like) of the shape steel can be prevented or suppressed.SOLUTION: There is provided a bend straightening method by which a flange 102 is supported with a supporting roll 1 from a surface on a side opposite from a web 101, respective right and left flanges 102a, 102b are pressurized with a pair of straightening rolls 2, 3 from surfaces on the side of the web 101 thereby sandwiched by compression between the supporting roll 1 and the straightening rolls 2, 3 in a direction opposite to the supporting roll 1, and the pressuring forces to the respective right and left flanges 102a, 102b sandwiched by compression are controlled individually so as to maintain at a predetermined value which is set according to the bend or the camber of a wide flange beam 100.

Description

  INDUSTRIAL APPLICABILITY The present invention is suitably used for a shape steel having a web and a flange having a right flange portion and a left flange portion projecting from the left and right from at least one end in the height direction of the web, such as an H-shape steel and a T-shape steel. The present invention relates to a bending straightening apparatus for a shaped steel, and a method for straightening a curved shape suitable for straightening such a shaped steel.

  This type of shape steel is manufactured by a method of welding and assembling steel plates or a method of hot rolling after removing the scale of a material to be rolled heated in a heating furnace. A universal rolling mill used in hot rolling is a rolling mill provided with a pair of upper and lower horizontal rolls and a pair of left and right vertical rolls. By rolling down, the shape of the steel product is made.

  By the way, a shape steel formed by hot rolling is warped or bent due to a difference in the rolling reduction of the flange during hot rolling or a temperature difference during cooling. Therefore, the shaped steel is corrected after cooling in the cooling bed to obtain a product with a desired shape. That is, taking the case of the H-section steel as an example, as shown in FIG. 2, for example, the H-section steel 100 includes a web 101 and two flanges 102 respectively provided on both sides in the height direction of the web 101. It is comprised. When the H-section steel 100 is produced by rolling, as shown in FIG. 5A, the H-section steel 100 is bent in the height direction of the web 101 (the amount of bending is indicated by δ), Alternatively, as shown in FIG. 3A, the warp in the thickness direction of the web 101 (the amount of warpage is indicated by a symbol S) may occur entirely or locally. As a method of reducing such “bend” and “warp”, a method of adjusting rolling conditions in universal rolling is known.

However, the occurrence of bending and warping of H-shaped steel is caused by unbalance in rolling in universal rolling and defective shape of the material to be rolled, that is, various asymmetric rolling elements on the universal rolling mill and material to be rolled in various directions. It is very difficult to finely adjust the rolling conditions of the universal rolling mill corresponding to all these factors.
Therefore, when bending or warping cannot be prevented even by adjusting the rolling conditions, a method of correcting the rolled H-section steel warmly or coldly becomes indispensable. With regard to such a method, although correction is usually performed online with a roller straightening machine for warping, the effect of the roller straightening machine is less effective for bending than with warping. Correction is performed in the purification process.

  As a method for correcting the bending of a shaped steel in the refining process, a correction method by three-point bending using a press machine is known (for example, see Patent Document 1). However, in the three-point bending correction by the press machine, there is a problem that the local bending of the leading end of the shaped steel cannot be corrected due to a mechanical restriction between the fulcrums of bending. In addition, the three-point bending correction by the press machine has a problem that the processing efficiency is low because it is a bending process in a state where conveyance of the shape steel is stopped.

  On the other hand, there is also a method of correcting the bending by rolling the flange surface on the bent side with a roller to extend the flange surface (see, for example, Patent Document 2). In the conventional rolling method, the straightening of the web side between the outer surface roll that presses the flange from the surface opposite to the web, and the flange having the right flange portion and the left flange portion projecting to the left and right, and the outer surface roll. And a pair of straightening rolls that support and clamp the left and right flanges, and apply a predetermined rolling force to the opposing rolls inside and outside the flanges to clamp the flanges. Such a rolling correction method can correct local bending of the shaped steel, and is also advantageous in terms of processing efficiency because it is straightened while the steel is being conveyed.

JP 2008-030090 A JP 2002-282934 A

However, when there is a difference in the plate thickness between the right and left flanges of the shape steel to be straightened, the conventional rolling method bend straightening method causes the shape steel There was a problem that other shapes (warping, twisting, etc.) deteriorated.
As shown in FIG. 4, in the case of correcting a shape steel having different flange thicknesses on the left and right sides, that is, a shape steel 100 having a thickness different from the flange thickness of the left flange portion 102b and the flange thickness of the right flange portion 102a, In the rolling method of bending correction, since the mechanism rolls down the outer roll of the flange, the roll gap cannot be changed according to the respective flange thicknesses of the left flange portion 102b and the right flange portion 102a, resulting in large warping and twisting. Will occur. In the shape steel formed by hot rolling, the flange thickness is often different depending on the part to be rolled, so that it has been difficult to apply the conventional bending correction technology by rolling.

  Therefore, the present invention has been made paying attention to such problems, and corrects the bending in the height direction of the web or the warping in the thickness direction by rolling while conveying the shape steel cold. In this case, even when there is a difference in plate thickness between the left and right flanges, it is possible to prevent or suppress the deterioration of other shapes (such as warping and twisting) of the shape steel, and for the shape steel bending correction method and shape steel Another object is to provide a correction device.

  In order to solve the above-described problem, a shape steel bending straightening device according to an aspect of the present invention includes a web, and a right flange portion and a left flange portion that project left and right from at least one end in the height direction of the web. A shape straightening device for a shape steel, which is used for a shape steel having a flange, and corrects the bending in the height direction of the web or the warpage in the thickness direction of the web by rolling while conveying the shape steel in a cold state. A support roll for supporting the flange from the surface opposite to the web, and the left and right flange portions by pressing the left and right flange portions from the web side surface between the support rolls. Each of the pair of straightening rolls and a pair of pressing force control means for individually controlling the pressing force of each of the pair of correction rolls. Bend It is characterized in that individually controlled to maintain a predetermined value set in accordance with the warp.

  In the bend straightening device for a shaped steel according to one aspect of the present invention, each straightening roll has a chock that supports each straightening roll so as to be slidable along a direction facing the support roll, and each pressing force control The means includes a hydraulic cylinder that presses the chock of each of the correction rolls in a direction opposite to the support roll, a direction control valve that switches between applying and releasing the pressing force of the hydraulic cylinder, the direction control valve, and the hydraulic pressure Pressure that is interposed in an oil passage between the cylinders and that allows the pressure of the hydraulic cylinder to be set to the predetermined value and to supply and discharge the pressure oil so that the pressure of the oil passage is maintained at the predetermined value. It is preferable to have a control valve.

  In addition, a method for correcting the bending of a shaped steel according to one aspect of the present invention includes a web and a flange having a right flange portion and a left flange portion projecting left and right from at least one end in the height direction of the web. A method of correcting the bending in the height direction of the web or the warp in the thickness direction of the web by rolling while transporting the shape steel in a cold state, the flange being the web The left and right flange portions are supported by a pair of straightening rolls by pressing the left and right flange portions from the web-side surface in a direction opposite to the support roll, and the left and right flanges that sandwich the left and right are supported by the support roll from the opposite surface. The pressing force for each flange portion is individually controlled so as to be maintained at a predetermined value set in accordance with the bending or the warping.

  According to the present invention, the pressing force on the left and right flange portions sandwiched between the support roll and the pair of straightening rolls is set to a predetermined value set according to the bending in the height direction of the web or the warping in the thickness direction. Since it is controlled individually so as to maintain it, even if there is a difference in plate thickness between the left and right flanges of the shape steel to be straightened, the difference in rolling reduction and elongation between the left and right flanges during rolling is reduced. can do. Therefore, it is possible to prevent or suppress the deterioration of other shapes (such as warpage and twist) after the straightening.

BRIEF DESCRIPTION OF THE DRAWINGS It is a front view of the bending correction apparatus of the rolling system which is one Embodiment of the bending correction apparatus for steel shapes which concerns on 1 aspect of this invention, In the same figure, the hydraulic circuit is also shown in figure. 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. It is a transverse cross section which shows the shape steel from which flange thickness differs on right and left.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings as appropriate. Here, this bending correction apparatus corrects the bending in the height direction of the web by rolling while conveying the shape steel in a cold state.
As shown in FIG. 1, this bending straightening device 10 is an example applied to an H-shaped steel 100 as a shaped steel to be straightened by rolling. 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 right flange portion 102 a and a left flange portion 102 b 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 FIG. 1, the bending correction device 10 includes a support roll 1 and a pair of correction rolls 2 and 3. The support roll 1 is pivotally supported by a chock (not shown) so as to support a lower flange 102 from a surface 102c opposite to the web 101 in the figure.

  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 correction rolls 2 and 3 is pivotally supported by the tips of the respective chocks 22 and 32 via the support shafts 21 and 31. Each chock 22, 32 is supported by a support mechanism 23, 33 so that the base end portion of the chock 22, 32 can slide in the direction facing the support roll 1. The pair of straightening rolls 2 and 3 are applied with pressing force by a pair of pressing force control means provided for each of the straightening rolls 2 and 3, so that the left and right flange portions 102 a and 102 b are supported on the support roll 1. It is designed to pinch between.

Hereinafter, a pair of pressing force control means will be described. Since the configuration of the pair of pressing force control means is the same, description will be made side by side as in the case of the pair of straightening rolls 2 and 3 described above.
Each pressing force control means includes hydraulic cylinders 24 and 34 that press the chocks 22 and 32 of the correction rolls 2 and 3 in the direction facing the support roll 1. Each hydraulic cylinder 24, 34 is a direction control valve 27 that pushes and pulls the piston of each hydraulic cylinder 24, 34 so that the application and release of the pressing force to the chocks 22, 32 by the respective hydraulic cylinders 24, 34 can be switched. It is connected to the. Further, pressure control valves 26 and 36 are connected to the oil passages between the hydraulic cylinders 24 and 34 and the direction control valve 27, respectively. The pressure control valves 26 and 36 are interposed in the oil passages on the side where the pistons of the hydraulic cylinders 24 and 34 are pushed out.

  The pressure control valves 26 and 36 maintain the hydraulic pressure set by the adjustment valves (relief valves) 26b and 36b and the adjustment valves 26b and 36b that can adjust the pressure of the pressure oil supplied to the hydraulic cylinders 24 and 34, respectively. Pilot oil passages 26p and 36p. That is, when the pistons of the hydraulic cylinders 24 and 34 are pushed to the side exceeding the set hydraulic pressure (piston retracting direction), the pressure from the flow rate adjusting valves 25 and 35 is increased by the operation of the pilot oil passages 26p and 36p. It is released to the side and maintains the set hydraulic pressure.

  On the other hand, when the pistons of the hydraulic cylinders 24 and 34 are further pushed out to lower the set hydraulic pressure, the oil path to the tank side is closed so as to return to the set hydraulic pressure by the operation of the pilot oil paths 26p and 36p. Maintain the oil path pressure at the set oil pressure. Here, the hydraulic pressure set by the adjusting valves 26b and 36b is determined based on the measured value of the bending of the web 101 of the H-shaped steel 100 in the height direction (bending amount δ (see FIG. 2A)). The predetermined value is set in advance from the data obtained by the above. As a result, each pressing force control means applies the pressing force for pressing the pair of straightening rolls 2 and 3 and the support roll 1 by rolling in accordance with the bending in the height direction of the web 101 (bending amount δ). Can be controlled individually so as to maintain the predetermined value.

Next, the bend straightening device 10, the method of straightening the shape steel using the same, and the function and effect thereof will be described.
When correcting the bending of the shape steel by the bending correction device 10, first, only the bent ones of the H-section steel 100 after cooling to a predetermined temperature in the cooling bed were extracted. Then, the bend in the height direction of the web 101 of the H-shaped steel 100 is measured on the entry side of the bend straightening device 10, and the measured values (the occurrence position of the bend and the bend amount δ (FIG. 2A) Based on the reference)), the adjustment valves 26b and 36b of the pressure control valves 26 and 36 are adjusted so that the pressure of the pressure oil to be applied is set to a predetermined value. In this embodiment, the adjustment valves 26b and 36b have the same set value.

  Next, the H-section steel 100 is placed on a plurality of table rollers that lead to the bend correction device 10. And while supporting the flange 102 (lower side in FIG. 1) which has a concave curvature with the support roll 1 from the surface 102c on the opposite side to the web 101, each of the left and right flange portions 102a, 102b is the surface on the web 101 side. By rolling the flange while conveying the H-shaped steel 100 cold in the longitudinal direction by the driving device while pressing in the direction facing the support roll 1 by pressing with a pair of straightening rolls 2 and 3, Correct the bending of the H-section steel 100.

Here, in the method for correcting the bending of the shape steel using the bending correction device 10, the pressing force control means described above applies the pressing force for clamping between the correcting rolls 2 and 3 in the height direction of the web 101. In this case, the left and right flanges 102a and 102b of the H-section steel 100 to be corrected have a difference in plate thickness. In addition, it is possible to reduce the difference in rolling reduction and the difference in elongation between the left and right flanges 102a and 102b that occur during rolling. Therefore, deterioration of other shapes (warp, twist, etc.) of the H-shaped steel 100 after straightening can be prevented or suppressed. Note that the reduction rate of the flange portion necessary for correcting the bending is often sufficient with a reduction rate of 1% or less in view of the general bending size of the hot-rolled H-section steel.
According to the present embodiment, the straightness rate of the product is improved from 65% to 80% by correcting the bending of the shape steel by the bending correction device 10. In addition, by correcting the local large bend, it was possible to reduce the disqualification caused by the bend (improved the disqualification rate from 1.5% to 0.3%).

In addition, the bending correction apparatus for shape steel and the method for correcting bending of a 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.
For example, although the said embodiment is an example which mainly correct | amends the bending | flexion in the height direction of a web, and also demonstrated with the example which set each adjustment valve 26b, 36b as the same setting value, it is not limited to this, When the H-shaped steel 100 has a warp (see FIG. 3A), the left and right adjustment valves 26b and 36b are adjusted based on the measured warpage amount (the symbol S shown in FIG. 3A). By making the left and right flanges 102a and 102b different, it is possible to correct “curvature” as well as “curvature.” In this case, the set value of the flange on the warped side (concave side) is set to that on the other side. Warpage can be corrected by making it larger than the set value.
Moreover, in the said embodiment, although the H-section steel 100 was demonstrated to the example as a shape steel, it is not restricted to this, The present invention is right and left projecting right and left from at least one end in the height direction of the web. If it is a shape steel provided with the flange which has this flange part, it is applicable to various shape steels.

DESCRIPTION OF SYMBOLS 1 Support roll 2, 3 Straightening roll 10 Curvature straightening device (Bending straightening device for shape steel)
22, 32 Chock 23, 33 Support mechanism 24, 34 Hydraulic cylinder 26, 36 Pressure control valve

Claims (3)

Used in a structural steel comprising a web and a flange having a right flange portion and a left flange portion projecting to the left and right from at least one end in the height direction of the web. A bend straightening device for shape steel that corrects bending in the height direction or warping in the thickness direction of the web by rolling,
A pair of support rolls that support the flange from a surface opposite to the web, and a pair of pressing the left and right flange portions between the support rolls by pressing the left and right flange portions from the web side surface. A pair of pressing force control means for individually controlling the pressing force of each of the pair of correction rolls,
Each of the pressing force control means individually controls the pressing force for clamping so as to maintain a predetermined value set in accordance with the bending or the warping. Each straightening roll has a chock that supports each straightening roll so as to be slidable along the direction facing the support roll,
The pressing force control means includes a hydraulic cylinder that presses the chocks of the correction rolls in a direction facing the support roll, a direction control valve that switches between applying and releasing the pressing force of the hydraulic cylinder, and the direction Pressure oil interposed in an oil passage between a control valve and the hydraulic cylinder so that the pressing force of the hydraulic cylinder can be set to the predetermined value and the pressure of the oil passage is maintained at the set predetermined value. The shape straightening device according to claim 1, further comprising a pressure control valve for supplying and discharging gas. Used in a structural steel comprising a web and a flange having a right flange portion and a left flange portion projecting to the left and right from at least one end in the height direction of the web. A method of correcting bending in the height direction or warping in the thickness direction of the web by rolling,
The flange is supported by a support roll from the surface opposite to the web, and the left and right flange portions are pressed by a pair of straightening rolls from the web side surface in a direction opposite to the support roll. A method for correcting the bending of a shaped steel, wherein the pressing force to each of the left and right flange portions to be pressed is individually controlled so as to maintain a predetermined value set in accordance with the bending or the warping.

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