Method for forming the short end of an unequal-sided angle steel, forming apparatus, and method for manufacturing an unequal-sided 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, a forming apparatus, and a method for producing unequal-leg angle steel for forming the short leg end of unequal-leg angle steel.

Background Art

[0002] In general, unequal-leg angle steel is manufactured through a hot rolling process including a heating step, a rough rolling step, an intermediate rolling step, and a finish rolling step. When finish-rolling a material to be rolled into unequal-leg angle steel in the finish rolling step of the hot rolling process, the short leg end of the unequal-leg angle steel is also formed by rolling rolls, but the shape accuracy obtained for the target shape may be insufficient in some cases.

[0003] Conventionally, for example, those disclosed in Patent Documents 1 and 2 have been proposed to improve the shape accuracy of the short leg end of this unequal-leg angle steel. In the method for forming the short leg end of unequal-leg angle steel disclosed in Patent Document 1, the short leg end of the unequal-leg angle steel rolled in the hot rolling process of unequal-leg angle steel is press-formed by the forming portion of a forming roller, and the short leg end is guided; the long leg end of the unequal-leg angle steel is guided by a guide roller disposed on the opposite side of the forming roller across the conveying path of the unequal-leg angle steel. Then, in the forming and guiding process of the short leg end, the surface side of the long leg of the unequal-leg angle steel is pressed by a pressing roller, the back side surface of the unequal-leg angle steel is supported by a receiving roller, and the outer peripheral surface of the receiving roller is in contact with the respective back side surfaces of the short leg and the long leg of the unequal-leg angle steel.

[0004] According to the method for forming the short leg end of unequal-leg angle steel disclosed in Patent Document 1, both the short leg end of the leading end portion of the unequal-leg angle steel in the conveying direction immediately after exiting the rolling roll and the short leg end of the trailing end portion of the unequal-leg angle steel in the conveying direction that has completely passed through the rolling roll can be formed over the entire length into a smoothly outwardly bulging arc-shaped curved surface without edges by the forming roller.

[0005] Furthermore, the method for forming the short end of an unequal-sided angle steel shown in Patent Document 2 involves pressing and forming the short end of the rolled unequal-sided angle steel with a forming section of a forming roller whose rotation axis is set in the width direction intersecting the height direction of the short end. During the forming process, the forming section facing the short end can control the pressing force by adjusting the forming roller in the height direction, and the width of the gap with the short end can be controlled by adjusting the forming roller in the width direction.

[0006] According to the method for forming the short end of an unequal-sided angle steel shown in Patent Document 2, in the forming process of the short end, the forming part facing the short end can have its pressing force controlled by adjusting the forming roller in the height direction. Furthermore, by adjusting the forming roller in the width direction, the width of the gap with the short end can be controlled, enabling stable forming work, miniaturizing the forming apparatus, simplifying adjustments on the line, and shortening the work time. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2015-77624 [Patent Document 2] Japanese Patent Publication No. 2021-45788 [Overview of the project] [Problems that the invention aims to solve]

[0008] However, the conventional methods for forming the short end of an unequal-sided angle steel, as shown in Patent Documents 1 and 2, had the following problems. In other words, in the method for forming the short end of an unequal-sided angle steel shown in Patent Document 1, during the forming guidance process of the unequal-sided angle steel, in addition to the forming roller and guide roller, a pressing roller presses the surface side of the long side of the unequal-sided angle steel, and a receiving roller supports the back side of the unequal-sided angle steel, with the outer surface of the receiving roller only in contact with the back sides of the short and long sides of the unequal-sided angle steel. Therefore, if the unequal-sided angle steel bends upward or downward relative to the conveying direction from the rolling roll, or bends to the left or right relative to the conveying direction, the restraining force on the unequal-sided angle steel during the forming guidance process of the short end may be insufficient, and the forming of the short end by the forming roller may not be performed properly. As a result, problems such as poor rounding of the short end of the unequal-sided angle steel or the occurrence of scratches or steps on the short end have occurred.

[0009] Furthermore, in the case of the forming method for the short-side end of an unequal-side angle steel shown in Patent Document 2, the support of the unequal-side angle steel during the forming process of the short-side end is only described as follows: the long-side end (not shown) of the unequal-side angle steel is guided while being restrained by a guide roller (not shown), and the short-side end of the unequal-side angle steel is pressed by a pressing roller (not shown) as it progresses. Therefore, the specific method of supporting the unequal-side angle steel is not mentioned, and concerns remain that if the unequal-side angle steel bends upward or downward in the direction of transport after exiting the rolling roll, or bends to the left or right in the direction of transport, the restraining force on the unequal-side angle steel during the forming guide process of the short-side end may be insufficient.

[0010] Accordingly, the present invention has been made to solve this conventional problem, and its objective is to provide a method for forming the short end of an unequal-sided angle steel, a forming apparatus, and a method for manufacturing an unequal-sided angle steel, which enable the short end to be formed with high precision by providing sufficient restraining force on the unequal-sided angle steel during the short end forming process, even if upward curvature, downward curvature, leftward curvature, or rightward curvature occurs in the unequal-sided angle steel before the short end forming process. [Means for solving the problem]

[0011] To solve the above problems, a method for forming the short end of an unequal-sided angle steel according to one aspect of the present invention is a method for forming the short end of an unequal-sided angle steel, comprising a short end forming step for forming the short end of an unequal-sided angle steel in a hot rolling process of the unequal-sided angle steel, wherein in the short end forming step, the short end of the unequal-sided angle steel is formed by forming rollers while the joint between the short and long sides of the unequal-sided angle steel is held from the outside by a pressing roller whose outer surface is shaped to conform to the shape of the outer surface of the joint between the short and long sides of the unequal-sided angle steel.

[0012] Furthermore, another embodiment of the present invention provides a forming apparatus for the short end of an unequal-sided angle steel, which is used in a short-end forming process for forming the short end of an unequal-sided angle steel in a hot rolling process of the unequal-sided angle steel, and comprises a forming roller for forming the short end of the unequal-sided angle steel in the short-end forming process, and a pressing roller whose outer surface has a shape that conforms to the shape of the outer surface of the joint between the short and long sides of the unequal-sided angle steel, and which holds the joint between the short and long sides of the unequal-sided angle steel from the outside in the short-end forming process.

[0013] Furthermore, another embodiment of the present invention provides a method for manufacturing unequal-sided angle steel, which involves forming the short-side end of the unequal-sided angle steel using the method for forming the short-side end of the unequal-sided angle steel described above. [Effects of the Invention]

[0014] According to the method, apparatus, and method for forming the short end of an unequal-sided angle steel according to the present invention, even if the unequal-sided angle steel is curved upward, downward, leftward, or rightward before the short end forming process, the short end can be formed with high precision by providing sufficient restraining force on the unequal-sided angle steel during the short end forming process. [Brief explanation of the drawing]

[0015] [Figure 1]It is a schematic configuration diagram of a rolling production line for unequal-angle angle steel to which the method for forming the short-side end portion of unequal-angle angle steel according to an embodiment of the present invention is applied. [Figure 2] It is a front view of a rolling apparatus for a short-side end portion in the rolling production line for unequal-angle angle steel shown in FIG. 1. [Figure 3] It is a diagram showing a state where, in a forming apparatus for a short-side end portion, the joint between the long side and the short side of unequal-angle angle steel is held from the outer surface by a pressing roller, and the short-side end portion of the unequal-angle angle steel is being formed by a forming roller. [Figure 4] It is a diagram showing details of a pressing roller holding mechanism. [Figure 5] It is a plan view from the exit side of a rolling roller to the rolling apparatus for the short-side end portion shown in FIG. 2. However, in FIG. 5, the rolling apparatus for the short-side end portion is shown as viewed from the upper side in the height direction of the unequal-angle angle steel. [Figure 6] It is a diagram for explaining modified examples of the pressing roller and the forming roller in the forming apparatus for the short-side end portion. [Figure 7] It is a front view of unequal-angle angle steel. [Figure 8] It is a diagram for explaining a forming apparatus for a short-side end portion according to a comparative example.

Description of Embodiments

[0016] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiments shown below exemplify apparatuses and methods for embodying the technical idea of the present invention, and the technical idea of the present invention does not limit the material, shape, structure, arrangement, etc. of components to the following embodiments. In addition, the drawings are schematic. Therefore, it should be noted that the relationship and ratio between thickness and planar dimensions are different from actual ones, and the drawings also include portions where the relationship and ratio of dimensions are different between each other.

[0017] The hot-rolling production line 1 for unequal-angle angle steel shown in FIG. 1 is provided with a heating furnace 2, a first roughing mill 3, a second roughing mill 4, an intermediate rolling mill 5, a finishing mill 6, and a forming device 7 for the short-side end of unequal-angle angle steel, which are sequentially arranged from the upstream side to the downstream side. Then, the unequal-angle angle steel S (see FIG. 7) is manufactured from a steel material as a rolling blank through a hot rolling process including a heating step by the heating furnace 2, a rough rolling step by the first roughing mill 3 and the second roughing mill 4, an intermediate rolling step by the intermediate rolling mill 5, a finish rolling step by the finishing mill 6, and a short-side end forming step by the forming device 7 for the short-side end.

[0018] Here, as shown in FIG. 7, the unequal-angle angle steel S is a steel product provided with a short side Sa and a long side Sb joined to extend perpendicularly from the short side Sa at a joint Sc located at one end of the short side Sa. In the example shown in FIG. 7, it is an unequal-leg unequal-thickness angle steel (NAB) in which the plate thickness of the short side Sa is thicker than the plate thickness of the long side Sb, but this embodiment also targets unequal-leg equal-thickness 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] Note that the outer surface SCS of the joint Sc between the short side Sa and the long side Sb of the unequal-angle angle steel S is formed by a right-angled surface formed by the outer surface (left side surface) SCS1 on the short side Sa side and the outer surface (upper surface) SCS2 on the long side Sb side. Further, the end of the short side Sa opposite to the joint Sc is defined as a short-side end Sa1, and the end of the long side Sb opposite to the joint Sc is defined as a long-side end Sb1.

[0020] Here, for the short-side end Sa1 of the unequal-angle angle steel S as a product, a roundness with a predetermined radius of curvature is required, and this rounded portion must not have steps, burrs, flaws, or the like. For example, when the unequal-angle angle steel S is an unequal-leg unequal-thickness angle steel (NAB) in which the length of the long side Sb is 200 mm, the length of the short side Sa is 90 mm, the thickness of the long side Sb is 8 mm, and the thickness of the short side Sa is 14 mm, a roundness with a radius of curvature of 2 mm or more is required for the short-side end Sa1.

[0021] In the heating process, the steel material, which is the rolling material, is heated in a batch-type or continuous-type heating furnace 2, for example. The rolling material heated in the heating process is then roughly rolled in a rough rolling process using a rough first rolling mill 3 and a rough second rolling mill 4, intermediate rolling in an intermediate rolling process using an intermediate rolling mill 5, and finish rolling in a finish rolling process using a finish rolling mill 6 to form the desired unequal-sided angle steel S shape.

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

[0023] Here, the forming device 7 at the short end is installed downstream of the finishing rolling mill 6, as shown in Figure 1. More specifically, as shown in Figure 5, the forming device 7 at the short end is attached via a base plate 10 to the downstream (front) ends in the transport direction of the left side guide 62 and the right side guide 63, which are located downstream (front) in the transport direction of the rolling roll 61 of the final stand of the finishing rolling mill 6.

[0024] As shown in Figure 5, the finished-rolled unequal-leg angle steel S is transported from the rolling roll 61 of the finishing rolling mill 6 in the transport direction indicated by the arrow (rear to front) between the left side guide 62 and the right side guide 63. The unequal-leg angle steel S then passes from its tip through the opening 10a formed in the base plate 10 to the forming device 7 at the short end. During this process, the unequal-leg angle steel S is guided by the side guide roller 64 installed on the right side guide 63.

[0025] During the transport of the unequal-sided angle steel S, as shown in Figure 2, the unequal-sided angle steel S is transported toward the forming device 7 at the short end in a direction in which the height and width directions of the unequal-sided angle steel S are inclined with respect to the vertical and horizontal directions of the forming device 7. As shown in Figure 2, the molding device 7 at the short end includes a molding roller 11, a pressing roller 12, a lower guide roller 13, and an upper guide roller 14.

[0026] The forming roller 11 forms the short end Sa1 of the unequal-sided angle steel S in the short end forming process by the short end forming device 7. As shown in Figures 2 and 3, the forming roller 11 is a cylindrical rotating body with a U-shaped forming recess 11a formed in an annular shape on its outer surface. In the short end forming process, the forming recess 11a receives the short end Sa1 on the lower side in the height direction of the unequal-sided angle steel S, forming the short end Sa1 into a rounded shape. The forming recess 11a is formed to impart a rounded shape to the short end Sa1 of the unequal-sided angle steel S that has a predetermined radius of curvature required for the final product. The forming roller 11 is fixed to a forming roller shaft 11b that is 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-sided angle steel S being conveyed.

[0027] Furthermore, the pressing roller 12 holds the joint portion Sc between the short side Sa and the long side Sb of the unequal-sided angle steel S from the outer surface SCS during the short-side end forming process. As shown in Figures 2 to 4, the pressing roller 12 is a stepped cylindrical rotating body having a small diameter portion 12a and a large diameter portion 12b, and during the short-side end forming process, the step 12c formed by the small diameter portion 12a and the large diameter portion 12b holds the outer surface SCS of the joint portion Sc from the upper side in the height direction of the unequal-sided angle steel S. In other words, the pressing roller 12 holds the outer surface SCS of the joint portion Sc of the unequal-sided angle steel S, which is pressed from the lower side in the height direction of the unequal-sided angle steel S by the forming roller 11, from the upper side in the height direction of the unequal-sided angle steel S. The press roller 12 is fixed to a press roller shaft 12d, which is rotatably supported by a pair of roller receiving parts 18b and 18c of a press roller holder 18 of a press roller holding mechanism 17 (described later), and rotates together with the press roller shaft 12d. The rotation axis CL12 of the press roller 12 extends in the width direction of the long side Sb of the unequal-sided angle steel S being transported.

[0028] The press roller 12 holds the joint Sc between the short side Sa and the long side Sb of the unequal-sided angle steel S from the outer surface SCS during the short-side end forming process. As a result, even if the unequal-sided angle steel S warps upward, downward, leftward, or rightward during the finish rolling process, the unequal-sided angle steel S is held in the predetermined position during the short-side end forming process, and the restraining force on the unequal-sided angle steel S is sufficient to form the short-side end Sa1 with high precision. Therefore, the short-side end Sa1 of the unequal-sided angle steel S that will become the product can be reliably given a curve with the required predetermined radius of curvature, and steps, burrs, scratches, etc. can be prevented from occurring in the curved portion.

[0029] As shown in Figures 2 and 5, the forming roller 11 and the pressing roller 12 are positioned such that the rotation axis CL11 of the forming roller 11 and the rotation axis CL12 of the pressing roller 12 are parallel to each other and extend in the width direction of the long side Sb of the unequal-sided angle steel S within the same plane (same plane of paper in Figure 2), and are positioned 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 transport direction of the unequal-sided angle steel S (rear to front direction as indicated by the arrow in Figure 5).

[0030] As a result, in the short-side end forming process, when forming the short-side end Sa1 of the unequal-sided angle steel S with the forming roller 11, the pressing roller 12 can firmly hold the joint Sc between the short side Sa and the long side Sb of the unequal-sided angle steel S from the outer surface SCS, allowing the short-side end Sa1 to be formed with high precision. However, 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-sided angle steel S, then the pressing roller 12 may not be able to properly hold the joint Sc when forming the short-side end Sa1 of the unequal-sided angle steel S with the forming roller 11.

[0031] In the short-side end forming apparatus 7 illustrated in Figures 2, 3, and 5, the restraint of the unequal-sided angle steel S in the short-side end forming process is further improved by including a lower guide roller 13 and an upper guide roller 14. Thus, it is preferable to include a lower guide roller 13 and an upper guide roller 14 in the short-side end forming apparatus 7. For example, the lower guide roller 13 guides the long side end Sb1 side of the unequal-sided angle steel S while restraining it during the short-side end forming process. As shown in Figures 2 and 3, the lower guide roller 13 is a cylindrical rotating body and guides the transport of the unequal-sided angle steel S by restraining the long side end Sb1 side of the unequal-sided angle steel S with its outer circumferential surface while rotating it during the short-side end forming process. The lower guide roller 13 is fixed to a lower guide roller shaft 13a that is rotatably supported in a 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-sided angle steel S being transported.

[0032] Furthermore, the upper guide roller 14 guides the surface (upper surface in the height direction) of the long side end Sb1 of the long side Sb of the unequal-sided angle steel S while constraining it during the short-side end forming process. As shown in Figures 2 and 3, the upper guide roller 14 is a cylindrical rotating body, and during the short-side end forming process, it rotates and constrains the surface (upper surface in the height direction) of the long side end Sb1 of the long side Sb of the unequal-sided angle steel S with its outer circumferential surface, guiding the transport of the unequal-sided angle steel S. The upper guide roller 14 is fixed to an upper guide roller shaft 14a that is rotatably supported in the 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-sided angle steel S being transported.

[0033] As shown in Figures 2 and 5, the lower guide roller 13 and the upper guide roller 14 are positioned such that the rotation axis CL13 of the lower guide roller 13 and the rotation axis CL14 of the upper guide roller 14 are parallel to each other in the width direction of the long side Sb of the unequal-sided angle steel S within the same plane (same plane of paper in Figure 2), and are at the same distance l13=l14 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-sided angle steel S (rear to front direction as indicated by the arrow in Figure 5). The rotation axis CL11 of the forming roller 11 is the same distance l11 from the axis CL61 of the rolling roll 61 of the final stand of the finishing rolling mill 6, the rotation axis CL12 of the press roller 12 is the same distance l12, the rotation axis CL13 of the lower guide roller 13 is the same distance l13, and the rotation axis CL14 of the upper guide roller 14 is the same distance l14.

[0034] Next, we will describe the upward pressure applied by the forming roller 11 to the short end Sa1 of the unequal-sided angle steel S in the height direction. In the example shown in Figure 2, the forming roller holder 15, which holds the forming roller 11, is fitted into the forming roller holder guide box 16 and is able to move forward and backward toward the short end Sa1 of the unequal-sided 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 end Sa1 of the unequal-sided angle steel S can be adjusted by a cylinder (not shown).

[0035] Regarding the upward pressure applied by the forming roller 11 to the short end Sa1 of the unequal-sided angle steel S in the height direction, the method disclosed in Patent Document 2 can also be used. Furthermore, as shown in Figures 2 and 4, the press roller 12 is held by a press roller holding mechanism 17. Specifically, the press roller holding mechanism 17 comprises a press roller holder 18 that holds the press roller 12, and a press roller holder guide box 21 into which the press roller holder 18 is fitted.

[0036] The press roller holder 18 comprises a top portion 18a and a pair of roller receiving portions 18b and 18c extending downward in the height direction from the top portion 18a. As described above, the pair of roller receiving portions 18b and 18c rotatably support both ends of the press roller shaft 12d that supports the press roller 12. The press roller holder guide box 21 comprises a top portion 21a and a pair of side portions 21b and 21c extending downward in the height direction from the top portion 21a, and is fixed to the base plate 10. The press roller holder 18 is positioned to move up and down in the height direction along the side portions 21b and 21c between the pair of side portions 21b and 21c.

[0037] Furthermore, a connecting shaft 20, which extends in the height direction of the unequal-sided angle steel S and passes through the top 21a of the press roller holder guide box 21, is fixed to the top 18a of the press roller holder 18 by height adjustment members 19a and 19b. The height position of the press roller 12 with respect to the connecting shaft 20 can be adjusted by adjusting the height fixing position of the press roller holder 18 with respect to the connecting shaft 20 using the height adjustment members 19a and 19b.

[0038] Furthermore, the lower guide roller 13 is held by the lower guide roller holder 22, as shown in Figure 2. The lower guide roller holder 22 is fitted into the lower guide roller holder guide box 23. The lower guide roller holder 22 rotatably supports both ends of the lower guide roller shaft 13a, which 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 positioned to move up and down in the height direction of the unequal-sided angle steel 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 way as the height position of the press roller 12. Furthermore, the upper guide roller 14 is held by the upper guide roller holder 24, as shown in Figure 2. The upper guide roller holder 24 is fitted into the 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, which 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 positioned to move up and down in the height direction 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 way as the height position of the press roller 12. Next, a method for forming the short end Sa1 of the unequal-sided angle steel S in the short end forming process using the short end forming apparatus 7 will be described.

[0043] As shown in Figure 5, the finished-rolled unequal-leg angle steel S is transported from the rolling roll 61 of the finishing rolling mill 6 in the transport direction indicated by the arrow (rear to front) between the left side guide 62 and the right side guide 63. The unequal-leg angle steel S then passes from its tip through the opening 10a formed in the base plate 10 to the forming device 7 at the short end. During this process, the unequal-leg angle steel S is guided by the side guide roller 64 installed on the right side guide 63.

[0044] Then, in the forming apparatus 7 for the short side end, as shown in Figures 2 and 3, the step 12c of the pressing roller 12 holds the joint Sc between the short side Sa and the long side Sb of the unequal-sided angle steel S from the outer surface SCS, and the forming recess 11a of the forming roller 11 forms the short side end Sa1 of the unequal-sided angle steel S. During the forming of the short end Sa1 by the forming roller 11, the pressing roller 12 and the forming roller 11 rotate to guide the unequal-sided angle steel S.

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

[0046] Thus, according to the forming method for the short end Sa1 of the unequal-sided angle steel S according to this embodiment, in the short end forming step, the short end Sa1 of the unequal-sided angle steel S is formed by a forming roller 11 while the joint Sc between the short side Sa and the long side Sb of the unequal-sided angle steel S is held from the outer surface SCS by a pressing roller 12 whose outer surface (step 12c) conforms to the shape of the outer surface SCS of the joint Sc between the short side Sa and the long side Sb of the unequal-sided angle steel S.

[0047] Furthermore, according to the forming apparatus 7 for the short side end Sa1 of the unequal-sided angle steel S as described in this embodiment, the forming apparatus 7 includes a forming roller 11 for forming the short side end Sa1 of the unequal-sided angle steel S in the short side end forming process, and a pressing roller 12 whose outer surface (step 12c) has a shape that conforms to the shape of the outer surface SCS of the joint Sc between the short side Sa and the long side Sb of the unequal-sided angle steel S, and which holds the joint Sc between the short side Sa and the long side Sb of the unequal-sided angle steel S from the outer surface SCS in the short side end forming process.

[0048] As a result, even if the unequal-sided angle steel S is warped upward, downward, leftward, or rightward during the finish rolling process (the process before the short-side end forming process), the unequal-sided angle steel S is held in the predetermined position during the short-side end forming process, and the short-side end Sa1 can be formed with high precision by providing sufficient restraining force to the unequal-sided angle steel S. Therefore, the short-side end Sa1 of the unequal-sided angle steel S that will become the product can be reliably given a curve with the required predetermined radius of curvature, and steps, burrs, defects, etc., can be prevented from occurring in the curved portion.

[0049] Furthermore, according to the forming method for the short end Sa1 of the unequal-sided angle steel S according to this embodiment, it is preferable to form the short end Sa1 of the unequal-sided angle steel S by forming roller 11 such that the rotation axis CL11 of the forming roller 11 and the rotation axis CL12 of the pressing roller 12 are parallel to each other in the same plane (same plane of paper in Figure 2), and the forming roller 11 and pressing 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 transport direction of the unequal-sided angle steel S (from back to front direction as indicated by the arrow in Figure 5).

[0050] Furthermore, according to the forming apparatus 7 for the short side end Sa1 of the unequal-sided angle steel S according to this embodiment, it is preferable that the forming roller 11 and the pressing roller 12 are positioned such that the rotation axis CL11 of the forming roller 11 and the rotation axis CL12 of the pressing roller 12 are parallel to each other in the width direction of the long side Sb of the unequal-sided angle steel S within the same plane, and that they are 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 transport direction of the unequal-sided angle steel S (from back to front as indicated by the arrow in Figure 5).

[0051] As a result, in the short-side end forming process, when forming the short-side end Sa1 of the unequal-sided angle steel S with the forming roller 11, the pressing roller 12 can firmly hold the joint Sc between the short side Sa and the long side Sb of the unequal-sided angle steel S from the outer surface ScS, allowing the short-side end Sa1 to be formed with high precision. However, 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 on the exit side of the finishing rolling mill 6 in the conveying direction of the unequal-sided angle steel S, then the pressing roller 12 may not be able to properly hold the joint Sc when forming the short-side end Sa1 of the unequal-sided angle steel S with the forming roller 11.

[0052] Although embodiments of the present invention have been described above, the present invention is not limited thereto and can be modified and improved in various ways. For example, the shape of the outer surface of the press roller 12 only needs to be similar to the shape of the outer surface SCS of the joint Sc between the short side Sa and the long side Sb of the unequal-sided angle steel S. If the shape of the outer surface SCS of the joint Sc is composed of a shape other than the right-angle plane formed by the outer surface (left side) 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 surface of the press roller 12 only needs to be similar to the shape other than the right-angle plane, and it does not necessarily need to be composed of a step 12c formed by the small diameter portion 12a and the large diameter portion 12b.

[0053] Furthermore, as shown in Figure 2, the rotation axis CL11 of the forming roller 11 and the rotation axis CL12 of the pressing roller 12 extend parallel to the width direction of the long side Sb of the unequal-sided angle steel S, and are inclined with respect to the manufacturing line (not shown) of the unequal-sided angle steel S that extends in the left-right direction (horizontal direction) in Figure 2. In contrast, as shown in the modified example of the forming roller 11 and pressing roller 12 in the forming apparatus 7 at the short side end in Figure 6, the forming roller 11 and the pressing roller 12 may be configured such that the rotation axis CL11 of the forming roller 11 and the rotation axis CL12 of the pressing roller 12 are parallel to the manufacturing line PL of the unequal-sided angle steel S that extends in the horizontal direction.

[0054] A modified example of the molding roller 11 and press roller 12 in the molding apparatus 7 at the short end shown in Figure 6 will be described. The forming roller 11 is a cylindrical rotating body with a U-shaped forming recess 11a formed in an annular shape on its outer circumferential surface. It is rotatably supported on the forming roller holder 15 such that its rotation axis CL11 is parallel to the manufacturing line PL of the unequal-sided angle steel S extending horizontally. The forming recess 11a is shaped to impart a rounded shape to the short-side end Sa1 of the unequal-sided angle steel S, which will become the product, having a predetermined radius of curvature. As described above, the unequal-sided angle steel S is conveyed toward the forming device 7 at the short-side end in a direction in which the height direction and the width direction of the long side Sb of the unequal-sided angle steel S are inclined with respect to the vertical and horizontal directions of the forming device 7.

[0055] On the other hand, the pressing roller 12 comprises a first frustoconical portion 12e having an outer circumferential surface whose outer diameter gradually increases, and a second frustoconical portion 12f having an outer circumferential surface whose outer diameter increases at a steep incline relative to the outer circumferential surface of the first frustoconical portion 12e, and is a rotating body formed by joining the small-diameter end face of the first frustoconical portion 12e and the small-diameter end face of the second frustoconical portion 12f. The pressing roller 12 is rotatably supported on roller receiving portions 18b and 18c such that its rotation axis CL12 is parallel to the manufacturing line PL of the unequal-sided angle steel S extending in the horizontal direction. Furthermore, in the short-side end forming process, the pressing roller 12 holds the outer surface SCS of the joint Sc of the unequal-sided angle steel S from above the forming apparatus 7 at the step 12g where the end face on the smaller diameter side of the first frustoconical portion 12e and the end face on the smaller diameter side of the second frustoconical portion 12f are joined.

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

[0057] Furthermore, while the example in Figure 6 shows the case where the rotation axis CL11 of the forming roller 11 and the rotation axis CL12 of the press roller 12 are parallel to each other, it is not necessary for these rotation axes CL11 and CL12 to be parallel to each other. For example, the rotation axis CL11 of the forming roller 11 may be made parallel to the width direction of the long side Sb of the unequal-sided angle steel S, as shown in Figure 3, and the rotation axis CL12 of the press roller 12 may be made parallel to the manufacturing line PL of the unequal-sided angle steel S that extends horizontally.

[0058] Furthermore, the above example shows a case in which a short-side end forming process is provided after the finish rolling process in the hot rolling process of the unequal-sided angle steel S, using a short-side end forming device 7 to form the short-side end Sa1 of the finish-rolled unequal-sided angle steel S. However, this short-side end forming process is not limited to after the finish rolling process. Depending on the forming rolling method of the unequal-sided angle steel S, it is also possible to provide the short-side end forming process after the intermediate rolling process or before the finish rolling process. Even in this case, even if the unequal-sided angle steel S has warped upwards, downwards, to the left, or to the right before the short-side end forming process, the unequal-sided angle steel S can be held in a predetermined position during the short-side end forming process, and the short-side end Sa1 can be formed with high precision by providing sufficient restraining force on the unequal-sided angle steel S. [Examples]

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

[0060] Table 1 shows the evaluation results of forming the short end Sa1 of the unequal-sided angle steel S.

[0061] [Table 1]

[0062] As shown in Table 1, 30 short-side ends Sa1 of unequal-sided angle steel S were formed using the forming apparatus 7 of the present invention example and the forming apparatus 100 of the comparative example. As a result, the number of short-side end Sa1 defects with rounded shape was 0 for the forming apparatus 7 of the present invention example, which was a better result than the forming apparatus 100 of the comparative example which had 3 defects. Furthermore, the number of short-side end Sa1 defects with scratches and steps was 0 for the forming apparatus 7 of the present invention example, which was a better result than the forming apparatus 100 of the comparative example which had 2 defects.

[0063] Furthermore, a defect in the rounded shape of the short edge Sa1 was determined if the radius of the rounding applied to the short edge Sa1 was less than 2 mm, and a defect in the scratches or steps of the short edge Sa1 was determined if there were scratches or steps of 0.2 mm or more in depth. From the above results, it was confirmed that the forming apparatus 7 of the present invention can form the short end Sa1 of the unequal-sided angle steel S with high precision. [Explanation of symbols]

[0064] 1. Hot rolling production line for unequal-sided angle steel. 2 Furnace 3. First rough rolling mill 4. Rough Rolling Mill No. 2 5. Intermediate Rolling Mill 6. Finishing Rolling Mill 7. Forming apparatus for the short end of an unequal-sided angle steel. 10 base plate 11. Molding rollers 11a Recess for molding 11b Molding roller shaft 12 Pressing rollers 12a Small diameter section 12b Large diameter section 12c step 12d Pressing roller shaft 13 Lower guide roller 13a Lower guide roller shaft 14 Upper guide roller 14a Upper guide roller shaft 15. Molding roller holder 16. Molding roller holder guide box 17. Presser roller holding mechanism 18 Presser roller holder 18a top 18b Roller support section 18c Roller support section 19a Height adjustment member 19b Height adjustment member 20 Connecting shaft 21 Presser 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 Rolling rolls at the final stand 62 Left side guide 63 Right-side guide 64 Side Guide Rollers CL11 Rotation axis of the molding roller CL12 Rotation axis of the presser roller CL13 Lower guide roller rotation axis CL14 Upper guide roller rotation axis CL61 Rolling Roll Axle S Unequal-sided 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 the short end of an unequal-sided angle steel, comprising a short end forming step for forming the short end of the finished-rolled unequal-sided angle steel after the finish-rolling step in the hot-rolling process of the unequal-sided angle steel, In the short-side end forming process, the joint between the short and long sides of the unequal-side angle steel is held from the outside by a pressing roller whose outer surface conforms to the shape of the outer surface of the joint between the short and long sides of the unequal-side angle steel, and the short-side end of the unequal-side angle steel is formed by a forming roller. A method for forming the short end of an unequal-sided angle steel, characterized in that the forming roller and the pressing roller are positioned at 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-sided angle steel.

2. The method for forming the short end of an unequal-sided angle steel according to claim 1, characterized in that the forming roller and the pressing roller are arranged such that the rotation axis of the forming roller and the rotation axis of the pressing roller are parallel to each other in the same plane.

3. A short-side end forming apparatus for unequal-sided angle steel, used in a short-side end forming process that forms the short-side end of the finished-rolled unequal-sided angle steel after the finish-rolling process in the hot-rolling process of unequal-sided angle steel, In the short-side end forming step, the system includes a forming roller for forming the short-side end of the unequal-sided angle steel, and a pressing roller whose outer surface has a shape that conforms to the shape of the outer surface of the joint between the short and long sides of the unequal-sided angle steel, and which holds the joint between the short and long sides of the unequal-sided angle steel from the outside during the short-side end forming step. A forming device for the short end of an unequal-sided angle steel, characterized in that the forming roller and the pressing roller are positioned at 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-sided angle steel.

4. The forming apparatus for the short end of an unequal-sided angle steel according to claim 3, characterized in that the forming roller and the pressing roller are arranged such that the rotation axis of the forming roller and the rotation axis of the pressing roller are parallel to each other in the same plane.

5. A method for manufacturing unequal-sided angle steel, characterized by forming the short end of the unequal-sided angle steel using the method for forming the short end of the unequal-sided angle steel described in claim 1 or 2.

Images