Method for molding short end of unequal angle steel, molding device, and method for manufacturing unequal angle steel

Abstract

To provide a method for molding the short end of unequal angle steel, a molding device, and a method for manufacturing an unequal angle steel capable of accurately molding the short end understanding that a binding force of the unequal angle steel is enough in a short end molding step even when upper bending, down bending, left bending, or right bending occurs in the unequal angle steel before the short end molding step.SOLUTION: The method for molding the short end of unequal angle steel comprises a short end molding step of molding the short end Sa1 of unequal angle steel S in the hot rolling step of the unequal angle steel S. In the short end molding step, by a press roller 12 the outer peripheral surface 12c of which has a shape similar to that of the outer surface SCS of a junction Sc of a short side Sa and a long side Sb of the unequal angle steel S, the short end Sa1 of the unequal angle steel S is molded by a molding roller 11 in a state where the junction Sc of the short side Sa and the long side Sb of the unequal angle steel S is held from the outer surface SCS.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a forming method and a forming device for forming the short side end portions of unequal angle steel, and a manufacturing method of unequal angle steel. [Background technology]

[0002] In general, unequal leg angle steel is manufactured by going through a hot rolling process including a heating process, a rough rolling process, an intermediate rolling process, and a finish rolling process. When the rolled material is finish-rolled into unequal angle steel in the finish rolling step of the hot rolling process, the short side ends of the unequal angle steel are also formed by the rolling rolls, but the shape precision obtained may be insufficient for the desired shape.

[0003] As a means for improving the shape accuracy of the short side end portions of this unequal leg angle steel, the means shown in Patent Documents 1 and 2, for example, have been proposed in the past. The method of forming the short side end of unequal angle steel shown in Patent Document 1 presses and forms the short side end of the rolled unequal angle steel in the hot rolling process of the unequal angle steel by the forming part of the forming roller, while guiding the short side end, and guides the long side end of the unequal angle steel by a guide roller arranged on the opposite side to the forming roller across the conveyance path of the unequal angle steel. Then, in the process of forming and guiding the short side end, the front side of the long side of the unequal angle steel is pressed by the pressing roller, and the back side of the unequal angle steel is supported by the receiving roller, and the outer circumferential surface of the receiving roller is in contact with the back side of each of the short side and long side of the unequal angle steel.

[0004] According to the method of shaping the short side end portions of unequal angle steel sheets shown in Patent Document 1, both the short side end portion of the front end portion of the unequal angle steel sheets in the conveying direction immediately after they come out of the rolling rolls, and the short side end portion of the rear end portion of the unequal angle steel sheets in the conveying direction after they have completely passed the rolling rolls, can be shaped by the forming rollers into a smooth, outwardly bulging arc-shaped curved surface with no edges along their entire length.

[0005] In addition, the method of forming the short side end of an unequal angle steel shown in Patent Document 2 presses and forms the short side end of a rolled unequal angle steel with a forming part of a forming roller having a rotation axis set in a width direction intersecting with the height direction of the short side as a rotation center, and during the forming process, the forming part facing the short side end can control the pressing force by adjusting the forming roller in the height direction, and can also control the width of the gap with the short side end by adjusting the forming roller in the width direction.

[0006] According to the method for forming the short side end of an unequal leg angle steel shown in Patent Document 2, in the process of forming the short side end, the pressing force of the forming part facing the short side end can be controlled by adjusting the forming roller in the height direction. Also, the width of the gap with the short side end can be controlled by adjusting the forming roller in the width direction, which enables stable forming work, realizes miniaturization of the forming device, and simplifies adjustment on the line, thereby shortening the work. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2015-77624 A [Patent Document 2] Patent Publication No. 2021-45788 Summary of the Invention [Problem to be solved by the invention]

[0008] However, the conventional methods for forming the short side end portions of unequal leg angle steels shown in Patent Document 1 and Patent Document 2 have the following problems. That is, in the case of the forming method of the short side end of the unequal angle steel shown in Patent Document 1, in the forming and guiding process of the unequal angle steel, in addition to the forming roller and the guide roller, the front side of the long side of the unequal angle steel is pressed by the pressing roller, the back side of the unequal angle steel is supported by the receiving roller, and the outer circumferential surface of the receiving roller is only in contact with the back side of each of the short side and long side of the unequal angle steel. Therefore, if the unequal angle steel is warped upward or downward with respect to the conveying direction from the rolling roll, or is bent left or right with respect to the conveying direction, the restraining force on the unequal angle steel is insufficient in the forming and guiding process of the short side end, and the forming roller may not be able to form the short side end well. Therefore, there are problems such as poor rounding of the short side end of the unequal angle steel, and scratches and steps are generated on the short side end.

[0009] Furthermore, in the case of the forming method of the short side end of an unequal angle steel shown in Patent Document 2, the support of the unequal angle steel in the process of forming the short side end is described only as follows: the long side end (not shown) of the unequal angle steel is guided while being restrained by a guide roller (not shown), and the short side end of the unequal angle steel advances while being pressed by a pressure roller (not shown). Therefore, no specific method of supporting the unequal angle steel is mentioned, and there is a concern that if the unequal angle steel warps upward or downward with respect to the conveying direction coming out of the rolling rolls, or bends left or right with respect to the conveying direction, the restraining force for the unequal angle steel will be insufficient in the process of forming and guiding the short side end.

[0010] Therefore, the present invention has been made to solve this conventional problem, and its object is to provide a method for forming the short side end of an unequal angle steel, a forming device, and a manufacturing method for an unequal angle steel, which can provide a sufficient restraining force for the unequal angle steel in the short side end forming process to form the short side end with high precision even if the unequal angle steel is bowed upward, bowed downward, left or right before the short side end forming process. [Means for solving the problem]

[0011] In order to solve the above problems, one embodiment of the present invention provides a method for shaping the short side end of unequal angle steel, which includes a short side end shaping process for shaping the short side end of the unequal angle steel in a hot rolling process of the unequal angle steel, and in the short side end shaping process, the short side end of the unequal angle steel is shaped by a shaping roller while holding the joint between the short side and long side of the unequal angle steel from the outside with a pressure roller whose outer peripheral surface has a shape that follows the shape of the outer surface of the joint between the short side and long side of the unequal angle steel.

[0012] In addition, a forming device for the short side end of unequal angle steel according to another aspect of the present invention is a forming device for the short side end of unequal angle steel used in a short side end forming process for forming the short side end of unequal angle steel in a hot rolling process of unequal angle steel, and is characterized in that it is equipped with a forming roller that forms the short side end of the unequal angle steel in the short side end forming process, and a pressure roller whose outer surface has a shape that follows the shape of the outer surface of the joint between the short side and long side of the unequal angle steel, and that in the short side end forming process holds the joint between the short side and long side of the unequal angle steel from the outer surface.

[0013] Furthermore, a manufacturing method for unequal leg angle steel according to another aspect of the present invention is characterized in that the short side end portion of the unequal leg angle steel is formed using the above-mentioned method for forming the short side end portion of the unequal leg angle steel. Effect of the Invention

[0014] According to the method for forming the short side end of unequal angle steel, forming device, and manufacturing method of unequal angle steel of the present invention, even if the unequal angle steel is curved upward, downward, left or right before the short side end forming process, the restraining force on the unequal angle steel can be sufficiently provided in the short side end forming process, so that the short side end can be formed with high precision. [Brief description of the drawings]

[0015] [Figure 1]1 is a schematic diagram of an unequal angle steel rolling production line to which a method for forming short side ends of unequal angle steel according to one embodiment of the present invention is applied. FIG. [Diagram 2] FIG. 2 is a front view of a rolling device for rolling short side ends in the rolling production line for unequal leg angle steel shown in FIG. [Diagram 3] This figure shows a state in which, in a short side end forming device, the joint between the long and short sides of the unequal angle iron is held from the outside by a pressure roller, while the short side end of the unequal angle iron is formed by a forming roller. [Figure 4] 5A and 5B are diagrams illustrating details of a pressure roller holding mechanism. [Diagram 5] It is a plan view from the exit side of the rolling roller to the rolling device of the short side end shown in Fig. 2. However, in Fig. 5, the rolling device of the short side end is shown as seen from above in the height direction of the unequal angle steel. [Figure 6] 13A and 13B are diagrams for explaining modified examples of the pressure roller and the forming roller in the short side end forming device. [Figure 7] FIG. [Figure 8] FIG. 13 is a diagram for explaining a forming device for a short side end portion of a comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiments shown below are merely examples of devices and methods for embodying the technical concept of the present invention, and the technical concept of the present invention is not limited to the following embodiments in terms of the materials, shapes, structures, arrangements, etc. of the components. In addition, the drawings are schematic, and therefore, it should be noted that the relationship between thickness and planar dimensions, ratios, etc. may differ from the actual relationship between thickness and planar dimensions, and the drawings may include parts in which the relationship between dimensions and ratios differ from one another.

[0017] The hot rolling production line 1 for unequal angle steel shown in Figure 1 is composed of a heating furnace 2, a first roughing rolling mill 3, a second roughing rolling mill 4, an intermediate rolling mill 5, a finishing rolling mill 6, and a forming device 7 for the short side ends of the unequal angle steel, arranged in sequence from the upstream side to the downstream side. The unequal angle steel S (see Figure 7) is manufactured by subjecting the steel material, which is the rolling material, to a hot rolling process including a heating process in a heating furnace 2, a rough rolling process in a first rough rolling mill 3 and a second rough rolling mill 4, an intermediate rolling process in an intermediate rolling mill 5, a finish rolling process in a finishing rolling mill 6, and a short side end shaping process in a short side end shaping device 7.

[0018] Here, the unequal leg angle steel S is a steel product having short sides Sa and long sides Sb joined at a joint Sc at one end of the short side Sa so as to extend at a right angle from the short side Sa, as shown in Fig. 7. In the example shown in Fig. 7, the unequal leg angle steel (NAB) is used in which the plate thickness of the short side Sa is thicker than the plate thickness of the long side Sb, but the present embodiment also covers unequal leg angle steel (ABS) in which the plate thickness of the short side Sa is the same as the plate thickness of the long side Sb.

[0019] In addition, the outer surface SCS of the joint Sc between the short side Sa and long side Sb of the unequal leg angle steel S is composed of a right-angled surface formed by the outer surface (left surface) SCS1 on the short side Sa side and the outer surface (top surface) SCS2 on the long side Sb side. The end of the short side Sa opposite to the joint Sc is referred to as a short side end Sa1, and the end of the long side Sb opposite to the joint Sc is referred to as a long side end Sb1.

[0020] Here, the short side end Sa1 of the unequal leg angle steel S that will become the product is required to be rounded with a specified radius of curvature, and this rounded portion must be free of steps, burrs, scratches, etc. For example, if the unequal leg angle steel S is an unequal leg unequal thickness angle steel (NAB) with a long side Sb of 200 mm, a short side Sa of 90 mm, a long side Sb of 8 mm, and a short side Sa of 14 mm, then the short side end Sa1 is required to be rounded with a radius of curvature of 2 mm or more.

[0021] In the heating process, the steel material to be rolled is heated, for example, in a batch or continuous heating furnace 2. The rolling material heated in the heating process is rough rolled in a rough rolling process using a first roughing rolling mill 3 and a second roughing rolling mill 4, intermediate rolled in an intermediate rolling process using an intermediate rolling mill 5, and finish rolled in a finish rolling process using a finish rolling mill 6, and is formed into the desired shape of unequal leg angle steel S.

[0022] However, when the rolled material is finish-rolled into unequal angle steel S in the finishing rolling process, the short side end portion Sa1 of the unequal angle steel S can also be formed by the rolling roll 61 (see Figure 5) in the finishing rolling mill 6, but the shape accuracy obtained may be insufficient for the desired shape. Therefore, after the finish rolling process in the hot rolling process of the unequal angle steel S, the short side end Sa1 of the finish rolled unequal angle steel S is shaped in a short side end shaping process by a short side end shaping device 7.

[0023] Here, the shaping device 7 for the short side end portions is installed on the downstream side of the finishing rolling mill 6, as shown in Fig. 1. Specifically, the shaping device 7 for the short side end portions is attached to the downstream (front) ends in the conveying direction of a left side guide 62 and a right side guide 63, which are located on the downstream (front) side in the conveying direction of a rolling roll 61 of the final stand of the finishing rolling mill 6, via a base plate 10, as shown in Fig. 5.

[0024] The finish-rolled unequal arm angle steel S is transported between a left side guide 62 and a right side guide 63 in the transport direction (rear to front direction) indicated by the arrow from the rolling rolls 61 of the finishing rolling mill 6, as shown in Fig. 5. Then, the unequal arm angle steel S passes from its tip through an opening 10a formed in the base plate 10 to reach the forming device 7 for the short side end portion. At this time, the unequal arm angle steel S is guided by a side guide roller 64 installed in the right side guide 63.

[0025] When transporting this unequal arm angle steel S, as shown in Figure 2, the unequal arm angle steel S is transported toward the forming device 7 at the short side end in a direction in which the height and width directions of the unequal arm angle steel S are inclined relative to the up-down and left-right directions of the forming device 7. As shown in FIG. 2, the short side end forming device 7 includes a forming roller 11, a pressure roller 12, a lower guide roller 13, and an upper guide roller 14.

[0026] The forming roller 11 forms the short side end Sa1 of the unequal angle steel S in the short side end forming process by the forming device 7 of the short side end. As shown in Figs. 2 and 3, the forming roller 11 is a cylindrical rotating body having a U-shaped forming recess 11a formed in an annular shape on the outer circumferential surface, and in the short side end forming process, the forming recess 11a receives the short side end Sa1 on the lower side in the height direction of the unequal angle steel S, and forms the short side end Sa1 into a rounded shape. The forming recess 11a is formed into a shape that gives the short side end Sa1 a roundness having a predetermined radius of curvature required for the short side end Sa1 of the unequal angle steel S to be a product. The forming roller 11 is fixed to a forming roller shaft 11b rotatably supported by a forming roller holder 15, and rotates together with the forming roller shaft 11b. The rotation axis CL11 of the forming roller 11 extends in the width direction of the long side Sb of the unequal leg angle iron S that is being conveyed.

[0027] The pressure roller 12 holds the joint Sc between the short side Sa and long side Sb of the unequal angle steel S from the outer surface SCS in the short side end forming process. As shown in Figs. 2 to 4, the pressure roller 12 is a stepped cylindrical rotor having a small diameter portion 12a and a large diameter portion 12b, and holds the outer surface SCS of the joint Sc from the upper side in the height direction of the unequal angle steel S with a step 12c formed by the small diameter portion 12a and the large diameter portion 12b in the short side end forming process. In other words, the pressure roller 12 holds the outer surface SCS of the joint Sc of the unequal angle steel S pressed from the lower side in the height direction of the unequal angle steel S by the forming roller 11 from the upper side in the height direction of the unequal angle steel S. The pressure roller 12 is fixed to a pressure roller shaft 12d rotatably supported by a pair of roller receivers 18b, 18c of a pressure roller holder 18 of a pressure roller holding mechanism 17 described later, and rotates together with the pressure roller shaft 12d. The rotation axis CL12 of the pressure roller 12 extends in the width direction of the long side Sb of the unequal leg angle steel S being conveyed.

[0028] The pressing roller 12 holds the joint Sc between the short side Sa and long side Sb of the unequal angle steel S from the outer surface SCS in the short side end forming process. As a result, even if the unequal angle steel S is warped upward, warped downward, bent left, or bent right during finish rolling, the unequal angle steel S is held in a predetermined position in the short side end forming process, and the binding force on the unequal angle steel S is sufficient to form the short side end Sa1 with high precision. Therefore, the short side end Sa1 can be reliably given a roundness with a predetermined radius of curvature required for the short side end Sa1 of the unequal angle steel S to be the product, and the occurrence of steps, burrs, scratches, etc. in the rounded portion can be prevented.

[0029] As shown in Figures 2 and 5, the forming roller 11 and the pressure roller 12 are arranged such that the rotation axis CL11 of the forming roller 11 and the rotation axis CL12 of the pressure roller 12 extend in the width direction of the long side Sb of the unequal angle steel S in the same plane (the same paper surface in Figure 2) and are parallel to each other, and are at the same distance l11 = l12 from the axis CL61 of the rolling roll 61 of the final stand of the finishing rolling mill 6 in the conveying direction of the unequal angle steel S (the rear-to-front direction shown by the arrow in Figure 5).

[0030] As a result, in the short side end forming step, when the forming roller 11 forms the short side end Sa1 of the unequal angle steel S, the pressing roller 12 can firmly hold the joint Sc between the short side Sa and long side Sb of the unequal angle steel S from the outer surface SCS, and the short side end Sa1 can be formed with high precision. If the rotation axis CL11 of the forming roller 11 and the rotation axis CL12 of the pressing roller 12 are not parallel to each other in the same plane, or if the rotation axis CL11 and the rotation axis CL12 are not at the same distance l11=l12 from the axis CL61 of the rolling roll 61 of the final stand of the finishing rolling mill 6 in the conveying direction of the unequal angle steel S, there is a possibility that the pressing roller 12 cannot properly hold the joint Sc when the forming roller 11 forms the short side end Sa1 of the unequal angle steel S.

[0031] In the short side end forming device 7 illustrated in Figures 2, 3 and 5, the lower guide rollers 13 and upper guide rollers 14 are attached to further improve the restraint of the unequal leg angle iron S in the short side end forming process. In this way, it is preferable that the lower guide rollers 13 and upper guide rollers 14 are attached to the short side end forming device 7. For example, the lower guide roller 13 guides while restraining the back surface (lower surface in the height direction) of the long side end Sb1 side of the long side Sb of the unequal angle steel S in the short side end forming process. As shown in Figs. 2 and 3, the lower guide roller 13 is a cylindrical rotating body, and during the short side end forming process, the outer circumferential surface of the lower guide roller 13 restrains while rotating the back surface (lower surface in the height direction) of the long side end Sb1 side of the long side Sb of the unequal angle steel S, and guides the conveyance of the unequal angle steel S. The lower guide roller 13 is fixed to a lower guide roller shaft 13a rotatably supported by the lower guide roller holder 22, and rotates together with the lower guide roller shaft 13a. The rotation axis CL13 of the lower guide roller 13 extends in the width direction of the long side Sb of the unequal angle steel S being conveyed.

[0032] In addition, the upper guide roller 14 guides while restraining the surface (upper surface in the height direction) of the long side Sb of the unequal angle steel S on the long side end Sb1 side in the short side end forming process. As shown in Figs. 2 and 3, the upper guide roller 14 is a cylindrical rotating body, and in the short side end forming process, the outer circumferential surface restrains while rotating the surface (upper surface in the height direction) of the long side Sb of the unequal angle steel S on the long side end Sb1 side, and guides the transportation of the unequal angle steel S. The upper guide roller 14 is fixed to an upper guide roller shaft 14a rotatably supported by an upper guide roller holder 24, and rotates together with the upper guide roller shaft 14a. The rotation axis CL14 of the upper guide roller 14 extends in the width direction of the long side Sb of the unequal angle steel S being transported.

[0033] 2 and 5, the lower guide roller 13 and the upper guide roller 14 are arranged at positions where the rotation axis CL13 of the lower guide roller 13 and the rotation axis CL14 of the upper guide roller 14 extend in the width direction of the long side Sb of the unequal angle steel S in the same plane (the same paper surface in FIG. 2) and are parallel to each other, and have the same distance l13=l14 from the axis CL61 of the rolling roll 61 of the final stand of the finishing mill 6 in the conveying direction of the unequal angle steel S (rear-to-front direction shown by the arrow in FIG. 5). The same distance l11 of the rotation axis CL11 of the forming roller 11 from the axis CL61 of the rolling roll 61 of the final stand in the finishing mill 6, the distance l12 of the rotation axis CL12 of the pressing roller 12, the distance l13 of the rotation axis CL13 of the lower guide roller 13, and the distance l14 of the rotation axis CL14 of the upper guide roller 14 are the same.

[0034] Next, the pressing of the short side end portion Sa1 of the unequal leg angle steel S upward in the height direction by the forming roller 11 will be described. In the example shown in Fig. 2, the forming roller holder 15 that holds the forming roller 11 is fitted into a forming roller holder guide box 16 and is capable of moving forward and backward toward the short side end Sa1 of the unequal side angle steel S. The forming roller holder guide box 16 is fixed to the base plate 10. The forward and backward positions of the forming roller 11 and the forming roller holder 15 relative to the short side end Sa1 of the unequal side angle steel S can be adjusted by a cylinder (not shown).

[0035] Regarding the pressing of the short side end portion Sa1 of the unequal leg angle steel S upward in the height direction by the forming roller 11, the method disclosed in Patent Document 2 can also be used. 2 and 4, the pressure roller 12 is held by a pressure roller holding mechanism 17. That is, the pressure roller holding mechanism 17 includes a pressure roller holder 18 that holds the pressure roller 12, and a pressure roller holder guide box 21 into which the pressure roller holder 18 is fitted.

[0036] The pressure roller holder 18 includes a top portion 18a and a pair of roller receiving portions 18b, 18c extending downward in the height direction from the top portion 18a. As described above, the pair of roller receiving portions 18b, 18c rotatably support both ends of the pressure roller shaft 12d that supports the pressure roller 12. The pressure roller holder guide box 21 has a top 21a and a pair of side parts 21b, 21c extending downward in the height direction from the top 21a, and is fixed to the base plate 10. The pressure roller holder 18 is disposed between the pair of side parts 21b, 21c along the sides 21b, 21c so as to be movable up and down in the height direction of the unequal leg angle iron S.

[0037] A connecting shaft 20 extending in the height direction of the unequal leg angle iron S and penetrating the top 21a of the pressure roller holder guide box 21 is fixed to the top 18a of the pressure roller holder 18 by height adjustment members 19a, 19b. The height position of the pressure roller 12 relative to the connecting shaft 20 can be adjusted by adjusting the fixed position of the pressure roller holder 18 relative to the connecting shaft 20 in the height direction by the height adjustment members 19a, 19b.

[0038] 2, the lower guide roller 13 is held by a lower guide roller holder 22. The lower guide roller holder 22 is fitted into a lower guide roller holder guide box 23. The lower guide roller holder 22 rotatably supports both ends of a lower guide roller shaft 13 a that supports the lower guide roller 13 .

[0039] The lower guide roller holder guide box 23 is fixed to the base plate 10. The lower guide roller holder 22 is disposed so as to be movable up and down in the height direction of the unequal leg angle iron S relative to the lower guide roller holder guide box 23. The lower guide roller holder 22 and the lower guide roller holder guide box 23 are connected by a connecting shaft (not shown) and a height adjustment member (not shown).

[0040] The height position of the lower guide roller 13 can be adjusted in the same manner as the height position of the pressure roller 12 is adjusted. 2, the upper guide roller 14 is held by an upper guide roller holder 24. The upper guide roller holder 24 is fitted into an upper guide roller holder guide box 25.

[0041] The upper guide roller holder 24 rotatably supports both ends of the upper guide roller shaft 14a that supports the upper guide roller 14. The upper guide roller holder guide box 25 is fixed to the base plate 10. The upper guide roller holder 24 is disposed so as to be movable up and down in the height direction of the unequal leg angle iron S relative to the upper guide roller holder guide box 25.

[0042] The upper guide roller holder 24 and the upper guide roller holder guide box 25 are connected by a connecting shaft (not shown) and a height adjustment member (not shown). The height position of the upper guide roller 14 can be adjusted in the same manner as the height position of the pressure roller 12 is adjusted. Next, a method for shaping the short side end Sa1 of the unequal angle steel S in the short side end shaping step by the short side end shaping device 7 will be described.

[0043] The finish-rolled unequal arm angle steel S is transported between a left side guide 62 and a right side guide 63 in the transport direction (rear to front direction) indicated by the arrow from the rolling rolls 61 of the finishing rolling mill 6, as shown in Fig. 5. Then, the unequal arm angle steel S passes from its tip through an opening 10a formed in the base plate 10 to reach the forming device 7 for the short side end portion. At this time, the unequal arm angle steel S is guided by a side guide roller 64 installed in the right side guide 63.

[0044] Then, in the short side end forming device 7, as shown in Figures 2 and 3, the joint Sc between the short side Sa and long side Sb of the unequal side angle steel S is held from the outer surface SCS by the step 12c of the pressure roller 12, and the short side end Sa1 of the unequal side angle steel S is formed by the forming recess 11a of the forming roller 11. When the short side end portion Sa1 is formed by the forming roller 11, the pressing roller 12 and the forming roller 11 rotate to guide the unequal leg angle iron S.

[0045] On the other hand, when the short side end Sa1 is formed by the forming roller 11, the back surface (lower surface in the height direction) of the long side Sb side of the unequal leg angle steel S can be restrained and guided by the lower guide roller 13, and the front surface (upper surface in the height direction) of the long side end Sb1 side can be restrained and guided by the upper guide roller 14. Then, in the short side end forming process by the short side end forming device 7, the short side end Sa1 of the unequal side angle steel S is formed from the longitudinal tip to the tail end of the unequal side angle steel S, and the short side end forming process is completed.

[0046] Thus, according to the method for forming the short side end Sa1 of the unequal arm angle steel S of this embodiment, in the short side end forming process, the short side end Sa1 of the unequal arm angle steel S is formed by the forming roller 11 while holding the joint Sc between the short side Sa and long side Sb of the unequal arm angle steel S from the outer surface SCS by the pressure roller 12, whose outer peripheral surface (step 12c) has a shape that follows the shape of the outer surface SCS of the joint Sc between the short side Sa and long side Sb of the unequal arm angle steel S.

[0047] In addition, according to the forming device 7 for the short side end Sa1 of the unequal angle steel S in this embodiment, in the short side end forming process, it is equipped with a forming roller 11 that forms the short side end Sa1 of the unequal angle steel S, and a pressing roller 12 whose outer peripheral surface (step 12c) has a shape that follows the shape of the outer surface SCS of the joint Sc between the short side Sa and long side Sb of the unequal angle steel S, and in the short side end forming process, holds the joint Sc between the short side Sa and long side Sb of the unequal angle steel S from the outer surface SCS.

[0048] As a result, even if the unequal angle steel S is warped upward, downward, left or right during finish rolling (the process before the short side end shaping process), the unequal angle steel S can be held in a specified position in the short side end shaping process, and the short side end Sa1 can be precisely shaped with sufficient restraining force on the unequal angle steel S. As a result, the short side end Sa1 can be reliably given a roundness with a specified radius of curvature required for the short side end Sa1 of the unequal angle steel S that will become the product, and steps, burrs, scratches, etc. can be prevented from occurring in the rounded portion.

[0049] In addition, according to the method for forming the short side end Sa1 of the unequal angle steel S of this embodiment, it is preferable to form the short side end Sa1 of the unequal angle steel S by the forming roller 11 in which the rotation axis CL11 of the forming roller 11 and the rotation axis CL12 of the pressure roller 12 are parallel to each other in the same plane (the same paper surface in Figure 2), and the forming roller 11 and the pressure roller 12 are positioned at the same distance l11 = l12 from the axis CL61 of the rolling roll 61 on the exit side of the finishing rolling mill 6 in the conveying direction of the unequal angle steel S (the rear-to-front direction indicated by the arrow in Figure 5).

[0050] Furthermore, according to the forming device 7 for the short side end portion Sa1 of the unequal angle steel S in this embodiment, it is preferable that the forming roller 11 and the pressure roller 12 are arranged such that the rotation axis CL11 of the forming roller 11 and the rotation axis CL12 of the pressure roller 12 extend in the width direction of the long side Sb of the unequal angle steel S in the same plane and are parallel to each other, and are positioned at the same distance l11 = l12 from the axis CL61 of the rolling roll 61 on the exit side of the finishing rolling mill 6 in the conveying direction of the unequal angle steel S (the rear-to-front direction indicated by the arrow in Figure 5).

[0051] As a result, in the short side end forming process, when the forming roller 11 forms the short side end Sa1 of the unequal angle steel S, the pressing roller 12 can firmly hold the joint Sc between the short side Sa and the long side Sb of the unequal angle steel S from the outer surface ScS, and the short side end Sa1 can be formed with high precision. If the rotation axis CL11 of the forming roller 11 and the rotation axis CL12 of the pressing roller 12 are not parallel to each other in the same plane, or if the rotation axis CL11 and the rotation axis CL12 are not at the same distance l11=l12 from the axis CL61 of the roll roll 61 on the exit side of the finishing rolling mill 6 in the conveying direction of the unequal angle steel S, there is a possibility that the pressing roller 12 cannot properly hold the joint Sc when the forming roller 11 forms the short side end Sa1 of the unequal angle steel S.

[0052] Although the embodiment of the present invention has been described above, the present invention is not limited to this and various modifications and improvements can be made. For example, the shape of the outer peripheral surface of the pressure roller 12 only needs to have a shape that imitates the shape of the outer surface SCS of the joint Sc between the short side Sa and long side Sb of the unequal arm angle steel S, and if the shape of the outer surface SCS of the joint Sc is configured as a shape other than a right angle surface formed by the outer surface (left side surface) SCS1 on the short side Sa side and the outer surface (top surface) SCS2 on the long side Sb side, the shape of the outer peripheral surface of the pressure roller 12 only needs to have a shape that imitates the shape of the other than the right angle surface, and does not necessarily need to be configured as a step 12c formed by the small diameter portion 12a and the large diameter portion 12b.

[0053] 2, the rotation axis CL11 of the forming roller 11 and the rotation axis CL12 of the pressure roller 12 extend parallel to the width direction of the long side Sb of the unequal side angle steel S, and are inclined with respect to the production line (not shown) of the unequal side angle steel S extending in the left-right direction (horizontal direction) in Fig. 2. In contrast, as in a modified example of the forming roller 11 and the pressure roller 12 in the forming device 7 of the short side end portion shown in Fig. 6, the forming roller 11 and the pressure roller 12 may be configured so that the rotation axis CL11 of the forming roller 11 and the rotation axis CL12 of the pressure roller 12 are parallel to the production line PL of the unequal side angle steel S extending horizontally.

[0054] A modified example of the forming roller 11 and the pressure roller 12 in the short side end forming device 7 shown in FIG. 6 will be described. The forming roller 11 is a cylindrical rotating body with a U-shaped cross section formed in an annular shape on the outer circumferential surface, and is rotatably supported by the forming roller holder 15 so that its rotation axis CL11 is parallel to the production line PL of the unequal angle steel S extending in the horizontal direction. The forming recess 11a is formed in a shape that gives a roundness having a predetermined radius of curvature required for the short side end Sa1 of the unequal angle steel S to be the product. As described above, the unequal angle steel S is transported toward the forming device 7 of the short side end in a direction in which the height direction and the width direction of the long side Sb of the unequal angle steel S are inclined with respect to the up-down direction and the left-right direction of the forming device 7.

[0055] On the other hand, the pressure roller 12 is a rotor having a first truncated cone-shaped portion 12e having an outer peripheral surface whose outer diameter gradually increases, and a second truncated cone-shaped portion 12f having an outer peripheral surface whose outer diameter increases at a steep incline with respect to the outer peripheral surface of the first truncated cone-shaped portion 12e, and is formed by joining the small-diameter end face of the first truncated cone-shaped portion 12e and the small-diameter end face of the second truncated cone-shaped portion 12f. The pressure roller 12 is rotatably supported by the roller receiving portions 18b and 18c so that its rotation axis CL12 is parallel to the manufacturing line PL of the unequal leg angle steel S extending in the horizontal direction. In the short side end forming process, the pressure roller 12 holds the outer surface SCS of the joint Sc of the unequal angle steel S from above the forming device 7 at a step 12g at the joint between the small diameter end face of the first truncated cone shaped portion 12e and the small diameter end face of the second truncated cone shaped portion 12f.

[0056] In this way, by configuring the forming roller 11 and the pressure roller 12 so that the rotation axis core CL11 of the forming roller 11 and the rotation axis core CL12 of the pressure roller 12 are parallel to the manufacturing line PL of the unequal angle steel S extending horizontally, even if the unequal angle steel S is curved upward, downward, left or right during finishing rolling (the process before the short side end forming process), the unequal angle steel S can be held in a predetermined position in the short side end forming process, and the restraining force on the unequal angle steel S can be sufficiently provided to form the short side end Sa1 with high precision.

[0057] 6 shows a case where the rotation axis CL11 of the forming roller 11 and the rotation axis CL12 of the pressure roller 12 are parallel to each other, but these rotation axis CL11, CL12 do not have to be parallel to each other. For example, as shown in FIG. 3, the rotation axis CL11 of the forming roller 11 may be parallel to the width direction of the long side Sb of the unequal arm angle steel S, and the rotation axis CL12 of the pressure roller 12 may be parallel to the manufacturing line PL of the unequal arm angle steel S that extends in the horizontal direction.

[0058] In the above example, a short side end forming process is provided by the short side end forming device 7 after the finish rolling process in the hot rolling process of the unequal angle steel S, and the short side end Sa1 of the finish rolled unequal angle steel S is formed. However, the short side end forming process is not limited to being provided after the finish rolling process. It is also possible to provide a short side end forming process after the intermediate rolling process or before the finish rolling process in accordance with the forming and rolling method of the unequal angle steel S. Even in this case, even if the unequal angle steel S is warped upward, warped downward, bent left, or bent right before the short side end forming process, the unequal angle steel S is held at a predetermined position in the short side end forming process, and the binding force for the unequal angle steel S is sufficient to form the short side end Sa1 with high precision. EXAMPLES

[0059] In order to verify the effects of the present invention, a short side end Sa1 of an unequal leg angle steel S having the following size was formed using a forming device 7 of an example of the present invention shown in Fig. 2 and a forming device 100 of a comparative example shown in Fig. 8. The forming device 100 of the comparative example shown in Fig. 8 has a similar configuration to the forming device for the short side end of an unequal leg angle steel shown in Patent Document 1. Size of unequal angle steel S: N200×90×8 / 14 (Length of long side Sb: 200 mm, length of short side Sa: 90 mm, thickness of long side Sb: 8 mm, thickness of short side Sa: 14 mm) Here, the forming apparatus 100 of the comparative example shown in Fig. 8 includes a forming roller 101 having a forming portion 101a for forming the short side end Sa1 of the unequal side angle steel S, a guide roller 102, a pressing roller 103, and a receiving roller 104. In the short side end forming process, the forming portion 101a of the forming roller 101 forms and guides the short side end Sa1, and the guide roller 102 guides the long side end Sb1 of the unequal side angle steel S. Also, in the short side end forming process, the pressing roller 103 presses the surface of the long side Sb of the unequal side angle steel S, and the receiving roller 104 supports the back surface of the long side Sb of the unequal side angle steel S.

[0060] Table 1 shows the evaluation results of forming the short side end portion Sa1 of the unequal leg angle steel S.

[0061] [Table 1]

[0062] As shown in Table 1, 30 short side ends Sa1 of unequal leg angle steel S were formed by the forming apparatus 7 of the present invention and the forming apparatus 100 of the comparative example. As a result, the number of short side ends Sa1 with defective rounding was zero in the case of the forming apparatus 7 of the present invention, which was a better result than the forming apparatus 100 of the comparative example, which had three defects. Also, the number of short side ends Sa1 with defects was zero in the case of the forming apparatus 7 of the present invention, which was a better result than the forming apparatus 100 of the comparative example, which had two defects.

[0063] Regarding the rounded shape of the short side end Sa1, a radius of the roundness given to the short side end Sa1 was judged to be defective if it was less than 2 mm, and regarding the scratches and steps of the short side end Sa1, a defect was judged to be defective if there was a scratch or step of 0.2 mm or more in depth at the short side end Sa1. From the above results, it was confirmed that the short side end portion Sa1 of the unequal leg angle steel S can be formed with high precision by the forming device 7 of the present invention. [Explanation of symbols]

[0064] 1. Unequal angle steel hot rolling production line 2 Furnace 3. Rough No. 1 Rolling Mill 4. No. 2 rough rolling mill 5. Intermediate rolling mill 6 Finishing rolling mill 7. Forming device for short side ends of unequal angle iron 10 Base plate 11 Forming roller 11a Molding recess 11b Forming roller shaft 12 Pressure roller 12a Small diameter section 12b Large diameter section 12c Step 12d Presser roller shaft 13 Lower guide roller 13a Lower guide roller shaft 14 Upper guide roller 14a Upper guide roller shaft 15 Forming roller holder 16 Forming roller holder guide box 17 Presser roller holding mechanism 18 Presser roller holder 18a top 18b Roller support 18c Roller support 19a Height adjustment member 19b Height adjustment member 20 Connecting shaft 21 Pressure roller holder guide box 21a Top 21b Side 21c Side 22 Lower guide roller holder 23 Lower guide roller holder guide box 24 Upper guide roller holder 25 Upper guide roller holder guide box 61 Final stand rolling mill roll 62 Left side guide 63 Right side guide 64 Side guide roller CL11 Forming roller rotation axis CL12 Rotation axis of pressure roller CL13 Rotation axis of lower guide roller CL14 Upper guide roller rotation axis CL61 Mill roll core S Unequal leg angle steel Sa Short side Sa1 Short side end Sb Long side Sb1 Long side end Sc junction SCS external surface

Claims

1. A method for forming short side ends of unequal angle steel, comprising a short side end forming step of forming short side ends of unequal angle steel in a hot rolling step of unequal angle steel, A method for forming the short side end of an unequal angle steel, characterized in that in the short side end forming process, the joint between the short side and long side of the unequal angle steel is held from the outside by a pressure roller whose outer surface has a shape that follows the shape of the outer surface of the joint between the short side and long side of the unequal angle steel, and the short side end of the unequal angle steel is formed by a forming roller.

2. The method for forming the short side end portion of unequal angle steel as described in claim 1, characterized in that the rotation axis of the forming roller and the rotation axis of the pressure roller are parallel to each other in the same plane, and the forming roller and the pressure roller are positioned at a position that is the same distance from the axis of the rolling roll of the final stand of the finishing rolling mill in the conveying direction of the unequal angle steel, and the short side end portion of the unequal angle steel is formed by the forming roller.

3. A forming device for the short side end of an unequal angle steel used in a short side end forming process for forming the short side end of an unequal angle steel in a hot rolling process of the unequal angle steel, A forming device for the short side end of unequal angle steel, characterized in that it comprises a forming roller that forms the short side end of the unequal angle steel in the short side end forming process, and a pressure roller whose outer surface has a shape that follows the shape of the outer surface of the joint between the short side and long side of the unequal angle steel and that holds the joint between the short side and long side of the unequal angle steel from the outer surface in the short side end forming process.

4. The forming device for the short side end portions of unequal angle steel as described in claim 3, characterized in that the forming roller and the pressure roller are positioned such that the rotation axis of the forming roller and the rotation axis of the pressure roller are parallel to each other in the same plane, and are the same distance from the axis of the rolling roll of the final stand of the finishing rolling mill in the conveying direction of the unequal angle steel.

5. A method for manufacturing unequal angle steel, comprising forming the short side end portion of unequal angle steel using the method for forming the short side end portion of unequal angle steel according to claim 1 or 2.

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