JPH08215753A - Method of roller-straightening h-section and device therefor - Google Patents

Abstract

PURPOSE: To provide a method of roller-straightening an H-section and a device therefor, where vertical bend of a H-section is straightened, change of the height of web is restricted, crack on a fillet part is decreased, the residual stress in the fillet part is decreased, and the remarkable effect of straightening against flange out of square and flange-warp is also achieved. CONSTITUTION: This device has at least one set of a pair of tapered horizontal rolls 10 each having tapered face in order to apply the plastic deformation on flanges 2 of an H-section 1 in the external side face part and pressing the internal side faces of a web 3 and a flange 2 of the H-section and a pair of vertical rolls 20 which are installed respectively corresponding to the tapered horizontal rolls 10 and each having a side part in a shape corresponding to the tapered face and pressing the external side face of the flange 2 of the H- section. Then, the plastic deformation of falling is given on the flange 2 of the H-section, vertical bending in the direction of web height is applied and the compressive stress is applied on the fillet part of the H-section.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an H-section roller straightening method and apparatus for straightening a bend by rolling down an H-section steel web, and in particular, it is manufactured by hot rolling or welding. It relates to the straightening of H-section steel.

[0002]

2. Description of the Related Art Since H-section steel as manufactured by hot rolling or welding has a bend or a warp as a whole or locally, it is usually shipped straight after being cold straightened. Is. As a cold straightening method, press straightening or roller straightening is often used. However, the former is not efficient and is not suitable for mass production because it is appropriately deformed by a pressing metal fitting while observing the shape before straightening. On the other hand, the latter (roller straightening method) is a method of straightening H-section steel by repeatedly bending it with a large number of rollers, which is efficient and is installed as an online facility at the factory.
It is used.

FIGS. 10 and 11 show a part of the contact state between the straightening roller and the H-section steel in the conventional roller straightening method in a partially extracted manner. As can be seen in these figures, the conventional roller straightening machine load method is shown in FIG.
0, a web reduction method in which the surface of the web 3 of the H-section steel 1 is loaded by the outer peripheral surface of the roller 4, and the end surface of the flange 3 of the H-section steel 1 is loaded by the outer peripheral surface of the roller 5, as shown in FIG. There are two types of monkey flange reduction method. However, whichever rolling method is adopted, the problems described below cannot be avoided.

That is, the drawback of the web reduction method is that, in the case of H-section steel having a wider flange width than the web plate thickness, the load by the roller 4 is converted into the radius of the web 3 and the flange 2 is sufficiently bent. Not only does it not deform, but roller 2
That is, only the local contact portion of the web 3 is plastically deformed, and in extreme cases, the root of the flange 2 and the web 3 (hereinafter referred to as a fillet portion) may even be cracked. Japanese Examined Patent Publication No. 57-61488 proposes to devise the shape of the roll for pressing the web 3 in order to suppress such local deformation, but in consideration of the situation where a thinner web product is required, Such a method cannot solve the essential problem.

A disadvantage of the flange reduction method is that when the flange width is wide and a large bending load is required, the end surface of the flange 2 which is in contact with the roller 5 is crushed and the width of the flange 2 is greatly increased. Is to decrease. Such a problem is that, as proposed in Japanese Patent Publication No. 56-40646 and Japanese Patent Application Laid-Open No. 53-141158, the load is reduced by increasing the distance between the rollers, and the diameter of the roller 5 is increased to increase the diameter of the roller 5 and the flange. Although it can be reduced to some extent by increasing the contact area with 3, the above-mentioned means not only inevitably increases the size of equipment and raises the construction cost, but also increases the distance between the rollers 5 to form an H shape. Since the length of the uncorrectable portion at both ends of the steel becomes long, these means naturally have a limit.

[0006]

As described above, it is obvious that the H-section steel having a large cross section cannot be effectively corrected by either the web reduction method or the flange reduction method, but it is unavoidable. The current situation is to use the web reduction method. In order to solve the drawbacks of the above two methods, FIG.
As shown in (for example, Japanese Examined Patent Publication No. 57-11728), a method of simultaneously pressing down the flange 2 and the web 3 by the rollers 4 and 5 has been proposed, but this method is also distributed to the flange 2 and the web 3. It is difficult to set the load to
If the height of the web 3 is expanded, the toes of the flange 2 may be crushed, the mechanism is complicated, and the web thickness is further reduced, it is inevitable that the above-mentioned problems are exposed.

Further, Japanese Patent Publication No. 56-45684 proposes a rather clever method for lowering the surface pressure applied to the flange when the flange is pressed down. However, in this method, the circumference of the portion in contact with the flange is proposed. Since the speeds are different, deformation is induced in the direction of the tilt of the flange, the load at the part where the flange starts contacting and the part that comes out of the contact of the flange becomes high, and as a straightening machine, it is a dedicated H-section steel machine. There are problems such as becoming.

Further, in Japanese Patent Application Laid-Open No. 4-59124,
By providing a vertical roll for web reduction and restraining the flange, the bending rigidity of the web is increased and local deformation of the web is attempted to be solved by suppressing the deformation. When a large reduction force for straightening is applied to the web, the flange is actually constrained by the web reduction roll as shown in FIG. 5 (see the circled portion in the figure). Therefore, the flexural rigidity of the web is almost the same as the usual method. Therefore, by simply restraining the movement of the flange with a vertical roll, there is no great difference in the deformation of the H-section steel compared to the conventional method, and it is not possible to suppress the change in the height of the web. It is impossible to solve.

Another major problem in the conventional method is that it cannot effectively correct a fall of the flange or a broken umbrella. In the above-mentioned JP-A-4-59124, JP-A-56-30027, JP-A-56-119624, etc., a vertical roll is provided, which is effective for tilting the flange and breaking the umbrella. However, since it is not based on the principle of correction, it cannot be said to be an effective correction method.

The present invention has been made to solve the above-mentioned problems, and corrects the vertical bending of the H-section steel, suppresses the change in web height, reduces cracks in the fillet portion, and An object of the present invention is to provide a roller straightening method for H-section steel and a device therefor which can reduce residual stress in the fillet portion and have a large straightening effect even against flange collapse and umbrella breakage.

[0011]

A roller straightening method for H-section steel according to an aspect of the present invention is such that a flange of H-section steel is pinched by a horizontal roll and a vertical roll to cause a plastic deformation by falling on the flange. Is applied repeatedly to bend the web in the height direction, and a compressive stress is applied to the fillet portion by the pressing force of the vertical roll. A roller straightening device for H-section steel according to another aspect of the present invention has a taper surface for giving plastic deformation to a flange of H-section steel on an outer side surface portion, and at least an inner side surface of the flange of the H-section steel. It is provided corresponding to each of the pair of horizontal rolls with taper to press and the horizontal roll with taper, and the side part has a shape corresponding to the taper surface, and presses the outer surface of the flange of H-section steel respectively. At least one pair of vertical rolls, and the flange of H-section steel is subjected to plastic deformation by tilting to bend up and down in the web height direction, and the fillet portion of H-section steel is provided. It applies a compressive stress. A roller straightening device for H-section steel according to another aspect of the present invention is a roller straightening device for H-section steel, in which horizontal rollers for pressing a web of H-section steel are provided alternately in the vertical direction along the traveling direction of the H-section steel. ,
A pair of horizontal rolls with a taper and a horizontal roll with a taper on the outer side surface, which have a tapered surface for plastically deforming the flange of the H-section steel, and press the wedge of the H-section steel and the inner side surface of the flange, respectively. At least one pair of vertical rolls, each of which has a shape corresponding to its tapered surface, is provided corresponding to each of the rolls, and presses the outer surface of the H-section steel flange, and , The flange of the H-section steel is subjected to tilting plastic deformation to bend up and down in the web height direction, and compressive stress is applied to the fillet portion of the H-section steel. An H-section steel straightening device according to still another aspect of the present invention is the above-mentioned straightening device, wherein the horizontal rolls provided at the final stage are arranged so as to have a gap with respect to the H-section web surface. . That is, the present invention relates to a horizontal roll having an outer side surface tapered (or a shape similar thereto), and a taper (or a shape similar thereto) corresponding to the taper of the horizontal roll (or a shape similar thereto). ) With the vertical roll, the plastic deformation is repeatedly applied from the outer surface of the flange of the H steel to the fall and umbrella break of the flange, and the vertical bending is repeatedly applied to the H-section steel to correct it, and The above object is achieved by applying compressive stress to the fillet portion by the roll.

[0012]

Next, the operation of the present invention will be described. FIG. 1 is a configuration diagram showing the basic configuration of the present invention. The figure (a) is the side view, the figure (b) is operation | movement explanatory drawing seen from the front, and the figure (c) is a top view. In this straightening device, horizontal rollers 10 that press the web along the traveling direction of the H-shaped steel are alternately arranged vertically, and a pair of vertical rolls 20 are provided corresponding to each horizontal roller 10. Has been. A taper is provided on the outer side surface portion of the horizontal roller 10 as shown in the drawing. The taper includes a taper inclined toward the center side and a taper inclined outward.
These are arranged alternately along the traveling direction of the H-section steel.
The vertical roller 20 also has a side portion corresponding to the side portion of the horizontal roller 10 corresponding thereto. The horizontal roller 10 arranged in the upper portion forms a tapered surface that expands outward as shown in FIG. 3B, but is inclined inward by the negative taper angle of the horizontal roller 10 arranged in the lower portion. To form a tapered surface. The vertical roll 20 has a concave shape or a convex shape in its side portion corresponding to the shape of the outer side portion of the corresponding horizontal roll 10.

This straightening device applies a rolling force to the inner surface of the flange 2 of the H-section steel 1 by means of the tapered surface provided on the outer side surface of the horizontal roll 10 when straightening the bending of the H-section steel. From the outer surface of the flange 2, the horizontal roll 10
By vertically pinching the flange 2 with a vertical roll 20 having a tapered side portion corresponding to the tapered surface of the H-shaped steel 1, the H-shaped steel 1 is repeatedly bent, and a fillet portion is formed from the outer surface of the flange 2 by the vertical roll 20. By applying compressive stress to the, there is no change in the height of the web, and correction is performed without causing fillet cracks.

Although FIG. 1 shows an example in which a horizontal roller 10 and a vertical roll 20 each having a taper are arranged on all stands, at least one horizontal roll 10 having a taper and a taper corresponding thereto are provided. If the vertical roll 20 that it has is installed, the effect can be exhibited.

FIG. 2 is an explanatory view showing the basic principle of correcting the shape by repeated bending. This repeated bending makes it possible to correct the shape whatever the initial shape. For example, the initial shape is κ01, κ02
Repeated bending of κ1, κ2, κ3, and κ4 should be applied to either κ03 (these shapes are bent or tilted in the opposite directions) or κ03 (in the same direction as κ01 but the degree of shape is different). For example, the shape converges to 0 point. Looking at an example of the initial shape κ01, it can be seen that by adding ± bending moments, the final shape converges to 0 point, that is, a state without distortion, through the history as shown by the solid line in the figure. The same applies to the initial shapes κ02 and κ03.

In view of the above-mentioned basic principle of correction, the following three points of problem awareness were obtained. Since a large bending moment must be applied in the initial stage of repeated bending to correct vertical bending, in the conventional web reduction method, the reduction force applied to the web increases and the web height changes. And the fillet portion may be cracked.
FIG. 9 is a diagram showing a stress state in an H-section steel cross section by a conventional web reduction method. The web is subjected to compressive and tensile stress due to bending by a roll, and the same stress is also applied to the fillet portion. Bending is applied to the flange by pressing this web, and compressive and tensile stresses are applied to the toes in the longitudinal direction. This tensile stress is the main cause of the change in the height of the web and the cracking of the fillet portion, and it is necessary to reduce it in some way. No method and device for correcting various degrees of flange collapse and umbrella break based on the above-mentioned basic principle of correction have been proposed. The fillet part is hot rolled to finish the shape of the H-shaped steel and is cooled at the end in the cooling process, and a large tensile residual stress remains.

The inventor of the present invention has found that the following method is effective for the above three points. On the other hand, it is necessary to positively apply compressive stress to the fillet portion in order to reduce the change in web height and the crack in the fillet portion due to the tensile stress. It was found that the compressive stress can be effectively applied to the fillet part by combining the horizontal roll with a taper on the outer side surface and a vertical roll having a corresponding taper angle.

FIG. 3 is a diagram showing the stress state at this time. It can be seen that the compressive stress on the fillet portion reduces the harmful tensile stress of the fillet portion within the elastic range. The taper angles θ1 and θ2 at this time are as shown in FIG. 4, but from the above, in order to positively apply compressive stress to the fillet portion, the sum of these angles must be 90 degrees or less. Is desirable. At this time,
θ2> θ1.

In contrast, it is necessary to repeatedly bend the flange as shown in the arrangement of FIG. 1 (c). FIG. 3 is a diagram showing a stress state at this time, and it is understood that the flange 2 is repeatedly plastically deformed by being repeatedly bent. In the combination of the vertical roll 20 and the horizontal roll 10 for the repeated bending of the flange 2, the taper angles are sequentially converged to 90 degrees and 0 degrees, respectively. Further, when the web 2 is pushed into the final stage horizontal roll, the web 2 is bent and affects the perpendicularity to the flange 3. Therefore, it is desirable that the horizontal roll 10 and the vertical roll 20 are not pressed down. The perpendicularity of the flange 3 is realized only by the pinch. Convergence of this angle is suitable for winds where a large amount of vertical bending is applied to the fillet portion, and a small amount of downward compression of the fillet portion is required at a later stage where the vertical bending is small. It is a thing. On the other hand, the reduction of the fillet portion is effective for reducing the residual stress.

By the way, the installation interval and the number of the vertical rolls 20 which apply the compressive stress to the fillet while repeatedly bending the flange 2 in combination with the horizontal roll 10 described above correspond to each stage of the conventional web pressing roller. It is desirable to install them separately, and the effect is exhibited regardless of whether they are driven or not. Further, the horizontal roll 10 of the present invention and the vertical roll 20 combined with the horizontal roll 10 of the present invention may be provided only in the front stage portion where the load is large, and the rear stage portion may adopt a normal roller straightening of the flange 2 or the web 3. . Of course, it can be applied to both a cantilever type and a double-sided type straightener. Then, by properly laying a guide for properly inserting the straightening device according to the present invention, an interval adjusting device for the vertical roller set, a vertical position adjusting device, and a driving device, continuous H-section steel of various cross-sectional dimensions can be formed. Effective correction is possible.

Although the side surface of the horizontal roll and the shape of the vertical roll are tapered here, any shape may be used as long as the flange can be repeatedly bent and the fillet portion can be given compressive stress. . For example,
A parabola or a trigonometric function can be considered as this shape, and a function that can be mathematically described is not necessarily used.

[0022]

【Example】

Example 1. FIG. 6 is a diagram showing the configuration of an H-section steel roll straightening device according to an embodiment of the present invention, in which the components shown in FIGS. 6A and 6B are alternately arranged. In this embodiment, a hydraulic cylinder 30 is provided as a mechanism for pressing the vertical roll 20 against the flange 2. Table 1 is a table showing the dimensions of the material to be straightened and the specifications of the actual straightening machine. In addition, Table 2 is a table showing a rolling setting for applying a compressive force to the fillet portion by the intermesh and the vertical roll as compared with the conventional web straightening method. Table 3 is a table showing a combination of the taper angles of the horizontal roll and the vertical roll. By this combination, it becomes possible to repeatedly bend the flange and efficiently apply compressive stress to the fillet portion. Table 4 compares the correction effect of the method of the present invention with the conventional method.

[0023]

[Table 1]

[0024]

[Table 2]

[0025]

[Table 3]

[0026]

[Table 4]

Therefore, it can be seen that the straightening according to this embodiment eliminates the change in the web height as compared with the conventional straightening web.

FIG. 7 is a characteristic diagram showing a change in web height due to vertical roll pressure. From this characteristic, it is also understood that the web height itself can be controlled by the vertical roll reduction load. In FIG. 7, the data points for flange restraint are all vertical rolls with no vertical rolls and horizontal rolls with no taper. From this characteristic, it is not effective to simply restrain the flanges with vertical rolls. I understand. The data in FIG. 7 all show average values.

FIG. 8 is a characteristic diagram of the hardness distribution of the fillet portion. From this characteristic, it is understood that the hardness of the fillet portion is increased by the reduction of the vertical roll and the residual stress of this portion is reduced.

Example 2. In this example, the vertical roll was installed only on the upper roll. Table 5 is a table showing the dimensions of the material to be straightened and the specifications of the actual straightening machine. Further, Table 6 is a table showing the intermesh as compared with the conventional web straightening method. Table 7 is a table showing combinations of the taper angles of the horizontal roll and the vertical roll. Here, it was shown that the bending was repeated in the same direction, and the effect was exhibited even if the number of applied rolls was small. Table 8 shows the effect of the present invention compared with the conventional method.

[0031]

[Table 5]

[0032]

[Table 6]

[0033]

[Table 7]

[0034]

[Table 8]

It can be seen that the straightening according to this embodiment eliminates the change in web height as compared with the conventional straightening web.

Example 3. In this example, the vertical roll was installed only on the # 2 roll which was given the maximum straightening bending. Table 9 is a table showing the dimensions of the material to be straightened and the specifications of the actual straightening machine. Table 10 is a table showing the intermesh compared with the conventional web straightening method. Table 11 is a table showing combinations of horizontal rolls and vertical rolls, and the main purpose here is to apply compressive stress to the fillet portion. Table 12 is a table showing the effect of the method of the present invention in comparison with the conventional method.

[0037]

[Table 9]

[0038]

[Table 10]

[0039]

[Table 11]

[0040]

[Table 12]

It can be seen that the straightening according to this embodiment eliminates the change in the web height as compared with the conventional straightening web.

[0042]

As described above, according to the present invention, the flange of the H-section steel is pinched by the horizontal roll and the vertical roll, and the flange is subjected to plastic deformation by tilting to repeatedly bend in the web height direction. Since the H-section steel is straightened by applying a compressive stress to the fillet portion by applying the pressing force of the vertical roll, the vertical bending of the H-section steel is straightened, the change in the web height is suppressed, and the fillet is suppressed. The cracks in the portion are reduced, the residual stress in the fillet portion is reduced, and a large correction effect is obtained even when the flange falls or the umbrella is broken. Therefore, since there is no correct method, it is possible to efficiently correct the shape of the H-shaped steel that has been straightened by a press with reduced productivity, and it is possible to exert an excellent effect of improving product quality.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a basic configuration of the present invention,
(A) is the side view, (b) is the front operation explanatory view,
(C) is a plan view.

FIG. 2 is an explanatory diagram showing the principle of shape correction by repeated bending in the present invention.

FIG. 3 is an explanatory diagram showing a stress situation that changes depending on a load of a compressive force applied by a vertical roll in the present invention.

FIG. 4 is an explanatory view showing the definitions of the taper angle of the horizontal roll and the taper angle of the vertical roll in the method of the present invention.

FIG. 5 is an explanatory diagram showing a restrained state of a flange in the conventional method.

FIG. 6 is a diagram showing a configuration of an H-section steel straightening device according to an embodiment of the present invention.

FIG. 7 is a characteristic diagram showing changes in web height due to vertical roll reduction of the present invention.

FIG. 8 is a characteristic diagram showing a change in hardness distribution of a fillet portion due to vertical roll rolling according to the present invention.

FIG. 9 is a diagram showing a stress state in a conventional correction method.

FIG. 10 is an explanatory view of a conventionally proposed method for straightening H-section steel (No. 1).

FIG. 11 is an explanatory view of a conventionally proposed straightening method for H-section steel (No. 2).

FIG. 12 is an explanatory view of a conventionally proposed straightening method for H-section steel (No. 3).

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Makoto Watanabe 1-2-2 Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd. Inside the Steel Pipe Corporation (72) Inventor Atsushi Watanabe 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Inside Nihon Steel Pipe Corporation

Claims (4)

[Claims] 1. A flange of H-shaped steel is pinched by a horizontal roll and a vertical roll, and plastic deformation of tilting is applied to the flange to repeatedly bend up and down in the web height direction,
A roller straightening method for H-section steel, wherein compressive stress is applied to the fillet portion by the pressing force of the vertical roll. 2. A pair of horizontal rolls with a taper, each of which has a taper surface on the outer side surface for giving plastic deformation to the flange of the H-section steel and presses the web of the H-section steel and the inner side surface of the flange, respectively. And a pair of vertical rolls provided corresponding to the respective taper-equipped horizontal rolls, the side portions of which have a shape corresponding to the taper surface, and which respectively press the outer surface of the flange of the H-section steel. At least one set, and subjecting the flange of the H-section steel to tilt plastic deformation to provide vertical bending in the web height direction, and applying compressive stress to the fillet portion of the H-section steel. An H-section steel straightening device. 3. A roller straightening device for H-section steel, in which horizontal bars for pressing the web of H-section steel are alternately provided in the vertical direction along the traveling direction of the H-section steel. A pair of horizontal rolls with a taper for pressing the inner surface of the web and the flange of the H-section steel, and taper surfaces for giving plastic deformation to the A side portion has a shape corresponding to the tapered surface, and has at least one pair with a pair of vertical rolls for pressing the outer surface of the flange of the H-section steel, and Give the flange a plastic deformation of tilting to give a vertical bending in the web height direction,
A roller straightening device for H-section steel, wherein compressive stress is applied to the fillet portion of the H-section steel. 4. The roller straightening device for H-section steel according to claim 3, wherein the horizontal rolls provided at the final stage are arranged so as to have a gap with respect to the web surface of the H-section steel.