Support structure

Abstract

To provide a support structure that is suitable for conveying a plurality of curved plate materials and enables the curved plate materials to be properly positioned at predetermined positions when assembling and welding the curved plate materials so as to manufacture a steel pipe with high roundness.SOLUTION: A support structure 10 according to one embodiment comprises: a center member 16 arranged inside a steel pipe 12; first stay members 18 that are provided on curved plate materials respectively; and a plurality of first arm members 22 that are detachably attached to the center member to extend from the center member 16 to butting parts of the curved plate materials, the first arm members each having strong a back member 26 provided on a tip thereof. The strong back members 26 are detachably attached so as to connect the first stay members 18 of the first curved plate material to the first stay members 18 of the second curved plate material.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a support structure that can be applied when manufacturing a steel pipe by connecting multiple curved plate materials by welding. [Background technology]

[0002] Conventionally, large-diameter steel pipes have been manufactured by forming steel plates into a U-shape or an O-shape using a UOE method or the like, and then welding the seam extending in the longitudinal direction, and various research and development efforts have been carried out (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 63-33942 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, bridges and offshore wind power generation facilities have tended to become larger, and there is a demand for even larger diameter steel pipes, for example, 10m or more in diameter. When the diameter of large-diameter steel pipes becomes larger than a certain level, it becomes necessary to prepare the steel pipes in multiple pieces circumferentially, taking into account the manufacturing and transportation of the steel pipes in factories, and to assemble and weld these curved plate materials at the construction site.

[0005] However, due to the bending of the curved plate material under its own weight, for example, the steel pipes can be crushed during welding work, reducing their roundness, and welding them together presents challenges. Furthermore, the series of processes, including the manufacturing and transportation of steel pipes, is carried out by a consortium of multiple companies and organizations, including steel pipe manufacturers, transport companies, and construction companies, and there are concerns that each of these processes can reduce the precision of the steel pipes, increasing the impact on their roundness, for example.

[0006] Therefore, the present disclosure aims to provide a configuration that is suitable for transporting multiple curved plate materials, and that, when assembling and welding the curved plate materials, allows the curved plate materials to be properly positioned in a predetermined position, enabling the production of steel pipes with higher precision. [Means for solving the problem]

[0007] One aspect of the present disclosure is A support structure used when manufacturing a steel pipe by welding a plurality of curved plate materials, a center member disposed inside the steel pipe; A first stay member provided on each of the curved plate materials, the first stay member being provided on each of the first curved plate material and the second curved plate material that are butt-welded; a plurality of first arm members detachably attached to the center member so as to extend from the center member to the butted portions of the curved plate members, each of the first arm members having a strong-back member at its tip; and Equipped with The strong-back member is removably attached to connect the first stay member of the first curved plate member and the first stay member of the second curved plate member. support structure to provide.

[0008] The support structure has the above configuration, that is, it includes the center member, the first stay member, and the first arm member. The strong-back member at the tip of the first arm member is removably attached to connect the first stay member of the first curved plate member to the first stay member of the second curved plate member. Therefore, the support structure can be attached to and detached from multiple curved plate members with high reproducibility, making this support structure suitable for transporting multiple curved plate members. Furthermore, according to the support structure with the above configuration, the first stay member of the first curved plate member can be connected to the first stay member of the second curved plate member using the first arm member removably attached to the center member. Therefore, by using the support structure, when assembling and welding multiple curved plate members, the curved plate members can be appropriately positioned and held in their predetermined positions, thereby enabling the production of steel pipes with higher precision.

[0009] Preferably, the center member is disposed so as to extend along the central axis of the steel pipe, which makes it possible to produce a steel pipe with higher roundness.

[0010] Preferably, the first arm member is removably attached to the center member and the first stay member using a connecting member having a tapered shape. With this configuration, by attaching the first arm member to the center member and the first stay member, the relative positions of the center member, first arm member, and first stay member can be more accurately positioned, and the reproducibility of the positioning can be more reliably achieved.

[0011] Preferably, the center member includes a central support portion disposed so as to extend along the central axis of the steel pipe, and an intermediate member attached to the central support portion and on which the plurality of first arm members are provided. This configuration allows the center member to be divided into more than one portion, thereby further improving the transportability of the support structure.

[0012] Preferably, the relay member includes a first relay member on which a plurality of the first arm members are provided and a second relay member on which a plurality of the first arm members are provided, and the first relay member is attached to the central support part offset from the second relay member in the direction of the central axis. This makes it possible to use the support structure to manufacture steel pipes that are longer in the direction of the central axis, i.e., in the axial direction.

[0013] Preferably, the support structure further includes a second stay member provided at a concavely curved portion of the curved plate away from the end of the curved plate in the circumferential direction, and a second arm member extending from the center member toward the second stay member, the second arm member being removably attached to the center member and the second stay member. Using this second arm member can more effectively prevent or suppress unintended bending of the curved plate, thereby enabling the production of steel pipes with higher precision. Furthermore, because the second arm member is removably attached to the center member and the second stay member, the support structure can be easily transported. [Effects of the Invention]

[0014] According to the support structure of the above-mentioned embodiment, the above configuration makes it possible to maintain favorable transportability of multiple curved plate materials, while also allowing the curved plate materials to be appropriately positioned in a predetermined position when assembling and welding the multiple curved plate materials, thereby enabling the production of steel pipes with higher precision. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a perspective view of a steel pipe assembled using a support structure according to one embodiment. [Figure 2] FIG. 2 is a plan view of a steel pipe having the support structure of FIG. [Figure 3] 3 is a cross-sectional view of the steel pipe shown in FIG. 1 taken along line III-III in FIG. 2. FIG. [Figure 4] FIG. 4 is an exploded perspective view of the support structure of FIG. 1 prior to initial connection to the steel pipe. [Figure 5] FIG. 5 is a perspective view of a curved plate material that will become part of a steel pipe. [Figure 6] FIG. 6 is a perspective view of a steel pipe in a state where the curved plate material of FIG. 5 is placed at a predetermined position on the steel pipe and a first stay member and a second stay member for one relay member are provided on the inner surface thereof. [Figure 7] 7 is a plan view of the vicinity of the tip of the first arm member of the support structure of FIG. 1 connected to the first stay member of the steel pipe. [Figure 8] FIG. 8 is a plan view of the vicinity of the tip of the second arm member of the support structure of FIG. 1 connected to the second stay member of the steel pipe. [Figure 9] 9 is a perspective view showing one relay member and a part of an arm member extending radially therefrom in the support structure of FIG. 1. FIG. [Figure 10] 10 is an enlarged view of a portion of FIG. 2, and is a plan view showing one relay member in the support structure of FIG. 1 and a portion of an arm member extending radially therefrom. [Figure 11] FIG. 11 is a cross-sectional view taken along line XI-XI in FIG. [Figure 12] FIG. 12 is a perspective view showing the base end of the arm member. [Figure 13] 13 is a perspective view of a relay member of the center member in the support structure of FIG. [Figure 14] 14 is a perspective view of the central support portion of the center member in the support structure of FIG. [Figure 15] FIG. 15 is a diagram for explaining the welding operation of steel pipes assembled using the support structure of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0016] A support structure according to an embodiment of the present disclosure will be described below with reference to the drawings.

[0017] FIG. 1 shows a perspective view of a steel pipe 12 assembled using a support structure 10 according to one embodiment. FIG. 2 shows a plan view of the steel pipe 12 having the support structure 10 of FIG. 1. FIG. 3 shows a cross-sectional view of the steel pipe 12 shown in FIG. 1 taken along line III-III in FIG. 2. FIG. 4 shows an exploded perspective view of the support structure 10 of FIG. 1 prior to initial connection to the steel pipe 12. FIG. 5 shows a perspective view of a curved plate material 12D that will form part of the steel pipe 12. Note that in the drawings, weld beads at the butt joints of the curved plate material 12D, i.e., at the seam S, etc., are omitted from the illustration.

[0018] The steel pipe 12 is a substantially cylindrical steel pipe having a predetermined length along the axis 12A. The steel pipe 12 includes multiple curved plate members 12D, i.e., multiple curved plate members 12D divided in the circumferential direction, i.e., n curved plate members 12D. Here, as shown in Figures 1, 2, and 4, the steel pipe 12 is fabricated by welding three curved plate members 12D together. Each curved plate member 12D is curved in an arc shape such that the central angle around the axis 12A corresponds to an arc of 360° / n. Since n = 3 as described above, the curved plate member 12D is curved in an arc shape such that the central angle corresponds to an arc of 120° (= 360° / 3). The outer diameter of the steel pipe 12 may be any number of meters, but is preferably 1 m (1,000 mm) or more, and particularly preferably several meters or more. For example, the outer diameter of the steel pipe 12 may be 10 m. In this embodiment, the curved plate members 12D of the steel pipe 12 are all formed to have the same dimensions and shape, but they may also have different dimensions and shapes. For example, when a steel pipe 12 is manufactured using three curved plate materials 12D, the first to third curved plate material 12D may have a circumferential length equivalent to an arc with a central angle of 100° around the axis 12A, the second curved plate material 12D may have a circumferential length equivalent to an arc with a central angle of 120° around the axis 12A, and the third curved plate material 12D may have a circumferential length equivalent to an arc with a central angle of 140° around the axis 12A.

[0019] The support structure 10 is used to position and support multiple curved plate members 12D at predetermined positions on the corresponding steel pipes 12. In other words, the support structure 10 is used when manufacturing a steel pipe 12 by welding multiple curved plate members 12D together. The support structure 10 includes a center member 16 positioned inside the steel pipe 12, stay members 18, 20 attached to each of the curved plate members 12D, and multiple arm members 22, 24 detachably attached to the center member 16 so as to extend from the center member 16 to the curved plate members 12D. Note that one of the stay members 18, 20, the stay member 18, is hereinafter referred to as the first stay member, and the other stay member 20, the second stay member. Also, one of the arm members 22, 24, the arm member 22, is hereinafter referred to as the first arm member, and the other arm member 24, the second arm member.

[0020] In the support structure 10, the steel pipes 12 are designed to have a circular cross section, so the center member 16 is positioned along the central axis 12A of the steel pipes 12. A first arm member 22 and a second arm member 24 are removably attached to the center member 16 so as to extend radially from the center member 16 toward the curved plate member 12D. Each arm member 22, 24 is then removably attached to a corresponding stay member 18, 20 of the curved plate member 12D. As shown in Figure 6, the stay members 18, 20 are each flat plate-shaped members that are arranged on the concavely curved inner surface of the curved plate member 12D so as to extend perpendicular to the central axis 12A and are fixed by welding.

[0021] As shown in FIG. 6 , the first stay members 18 are provided in pairs at the circumferential ends 12E of two adjacent curved plate members 12D to be butt-welded. These two adjacent curved plate members 12D correspond to the first curved plate member and the second curved plate member. A first arm member 22 is used to connect the two first stay members 18 at the ends 12E of the butt-welded butt joint of the adjacent curved plate members 12D. As shown in FIGS. 1 to 3 and 7 , the first arm member 22 has a strongback member 26, an example of a connecting member, at one end, i.e., the tip end 22a. This strongback member 26 connects the two first stay members 18 at the ends 12E of the butt-welded butt joint of the adjacent curved plate members 12D.

[0022] 6, the other, second stay member 20 is provided at the concave curved portion 12C away from the end portion 12E of the curved plate material 12D in the circumferential direction of the steel pipe 12, i.e., the curved plate material 12D. As shown in FIGS. 1 to 3 and 8, the second arm member 24 has a connecting member 28 at one end thereof, i.e., the tip end portion 24a. The connecting member 28 is removably attached to the second stay member 20.

[0023] 2, the arm members 22, 24 are members that extend straight in the longitudinal direction, with one end being the aforementioned tip ends 22a, 24a and the other end being the base ends 22b, 24b. The first arm member 22 has a rod member 22r with a substantially square cross section, a strong-back member 26 provided on the tip end 22a side of the rod member 22r, and a connecting member 22c (described later) provided on the base end 22b side of the rod member 22r. Similarly, the second arm member 24 has a rod member 24r with a substantially square cross section, a connecting member 28 provided on the tip end 24a side of the rod member 24r, and a connecting member 24c (described later) provided on the base end 24b side of the rod member 24r.

[0024] 9 to 14, the configuration of the center member 16 and the detachable attachment of the base ends 22b, 24b of the first and second arm members 22, 24 extending therefrom will be described.

[0025] The center member 16 includes a central support part 30 arranged to extend along the central axis 12A of the steel pipe 12, and an intermediary member 32 attached to the central support part 30. The intermediary member 32 is provided with a plurality of first arm members 22. The intermediary member 32 is also provided with a plurality of second arm members 24. The support structure 10 uses two intermediary members 32. One intermediary member 32 corresponds to the first intermediary member 32A, and the other intermediary member 32 corresponds to the second intermediary member 32B. As shown in FIG. 1 , the first intermediary member 32A is attached to the central support part 30 away from the second intermediary member 32B in the direction of the central axis 12A. In the following, since the first relay member 32A has the same configuration as the second relay member 32B and the first and second arm members 22, 24 are provided in the same manner, only the first relay member 32A will be described as a representative and a detailed description of the second relay member 32B will be omitted. Note that the stay members 18, 20 shown in Fig. 6 correspond to the arm members 22, 24 provided on the first relay member 32A, respectively, and the curved plate member 12D of the steel pipe 12 shown in Fig. 6 shows the state before the attachment of the stay members 18, 20 corresponding to the arm members 22, 24 provided on the second relay member 32B, respectively.

[0026] In this embodiment, the steel pipe 12 has three identical curved plate members 12D. A first stay member 18 is disposed at each of the circumferential end portions 12E of each curved plate member 12D. One second stay member 20 is disposed at approximately the circumferential center of the concavely curved portion 12C of each curved plate member 12D, away from the end portion 12E. Therefore, in the support structure 10, for each relay member 32, for example, three first arm members 22 and three second arm members 24 are alternately disposed in the circumferential direction relative to the first relay member 32A. As shown in FIG. 12 , at the base ends 22b and 24b of each arm member 22 and 24, connecting members (hereinafter referred to as second connecting members) 22c and 24c are welded to rod members 22r and 24r. The second connecting members 22c and 24c are each flat plate-shaped members having the same configuration and are welded to the same side of the corresponding arm member in the direction of the axis 12A.

[0027] 13, the first relay member 32A is a substantially hexagonal, flat-plate member having a substantially hexagonal hole 32c at its center. Around the hole 32c, a substantially hexagonal frame portion 32d extending in the thickness direction of the first relay member 32A and extension portions 32f extending radially from the frame portion 32d toward corners 32e of the first relay member 32A are provided.

[0028] As shown in Figures 9 and 10, the second connecting member 22c, 24c of one of the arm members 22, 24 is disposed between adjacent extension portions 32f of the first relay member 32A. The second connecting member 22c, 24c is attached to the first relay member 32A using a bolt B1 and a tapered pin P. As shown in the cross-sectional view of Figure 11, the bolt B1 is threaded into a nut N1, and the tapered pin P is a connecting member having a tapered shape. As shown in Figure 12, three holes H1, H2, and H3 are formed on both sides of the rod members 22r, 24r of the arm members 22, 24 of the second connecting member 22c, 24c along the longitudinal direction of the arm members 22, 24, and the central hole H2 of the three holes H1, H2, and H3 is a tapered pin hole corresponding to the tapered pin P. Similarly, as shown in FIG. 13 , holes H4, H5, and H6 corresponding to holes H1, H2, and H3 of the second connecting members 22c and 24c are provided in the relay members 32 and 32A. Bolts B1 or tapered pins P are inserted into these holes to attach the second connecting members 22c and 24c of the arm members 22 and 24 to the first relay member 32A. Therefore, the second connecting members 22c and 24c can be detachably attached to the first relay member 32A, and the use of tapered pins P improves their positioning accuracy. Note that instead of the tapered pins P, other connecting members having a tapered shape, such as tapered screws with threads, may be used, and the corresponding holes may have a configuration appropriate for the tapered pins. This also applies to the other tapered pins P described below.

[0029] The central support part 30 shown in FIG. 14 is inserted into the central hole 32c of the first relay member 32A. The central support part 30 has a base part 34 and three linear members 36. The base part 34 is a generally hexagonal flat member, and each linear member 36 extends perpendicularly from the base part 34 and has a generally L-shaped cross section. The three linear members 36 are spaced apart from one another and, in this example, are arranged at 120° intervals around the central axis 12A in the assembled support structure 10 shown in FIGS. 1 and 2, with one end of each linear member 36 welded to the base part 34. The linear members 36 are connected to the frame part 32d near the base end 22b of the first arm member 22 using bolts B2 and nuts N2, with a spacer SP interposed between the linear members 36 and the frame part 32d (see FIG. 10). Therefore, the central support part 30 is removably attached to the first relay member 32A.

[0030] FIG. 7 shows a plan view of the vicinity of the tip 22a of the first arm member 22 in the support structure 10 provided on the steel pipe 12. As described above, the tip 22a of the first arm member 22 has the strongback member 26. The strongback member 26 is a flat, approximately rectangular member with multiple holes on each side of the rod member 22r of the first arm member 22. The first stay member 18 of one curved plate material 12D to be butt-welded is connected to one side of the rod member 22r of the first arm member 22 of the strongback member 26 using a bolt B1 (and a nut N1, not shown in FIG. 7) and a tapered pin P. Similarly, the first stay member 18 of the other curved plate material 12D to be butt-welded is connected to the other side of the rod member 22r of the first arm member 22 of the strongback member 26 using a bolt B1 (and a nut N1, not shown in FIG. 7) and a tapered pin P. By attaching this bolt B1 and tapered pin P, the first arm member 22, which extends radially from the center member 16 toward the butt portion of the curved plate material 12D, can be fixed to the curved plate material 12D so as to support the curved plate material 12D from the inside of the steel pipe 12. Therefore, by providing the first arm member 22, the curved plate material 12D can be reliably positioned at a predetermined position on the steel pipe 12, and on the other hand, by removing the first arm member 22, the curved plate material 12D can be easily disassembled and carried.

[0031] Figure 8 shows a plan view of the vicinity of the tip 24a of the second arm member 24 in the support structure 10 provided on the steel pipe 12. As described above, the tip 24a of the second arm member 24 has the connecting member 28. The connecting member 28 is a flat, approximately rectangular member that is narrower than the strong-back member 26 and has multiple screw holes, three screw holes in this example, on each side of the rod member 24r of the second arm member 24. The second stay member 20 of the curved plate material 12D is connected to the connecting member 28 of the second arm member 24 using a bolt B1 (and a nut N1, not shown in Figure 8) and a tapered pin P. By attaching this bolt B1 (and nut N1 not shown in FIG. 8) and tapered pin P, the second arm member 24 extending radially from the center member 16 toward the concavely curved portion 12C of the curved plate material 12D can be fixed to the curved plate material 12D so as to support the curved plate material 12D from the inside of the steel pipe 12. Therefore, by providing the second arm member 24, an appropriate support force can be applied to the concavely curved portion 12C away from the end portion 12E of the curved plate material 12D, thereby suppressing deformation of the concavely curved portion 12C. Note that each tapered pin P has the same configuration, but may have different configurations. Also, the above bolts B1 have the same configuration, but may have different configurations.

[0032] When the support structure 10 assembled in this manner supports three curved plate members 12D of the steel pipe 12, the roundness of the steel pipe 12 can be sufficiently maintained. Therefore, as shown in FIG. 15, when the steel pipe 12 is positioned on the welding table 40 so that the central axis 12A is approximately horizontal, the steel pipe 12 can maintain a highly round, approximately cylindrical shape. On the welding table 40, the steel pipe 12 can be rotated around the central axis 12A by rotating rollers 42, 44. Therefore, when welding the joint portion, i.e., the seam portion S, of the curved plate member 12D to be butt-welded from the outside, the pipe can be positioned directly above as shown by arrow A1 in FIG. 15, allowing for more efficient welding from directly above. Furthermore, when welding the joint portion, i.e., the seam portion S, of the curved plate member 12D to be butt-welded from the inside, the pipe can be more efficiently welded downward from the inside of the central axis 12A of the steel pipe 12, i.e., directly above.

[0033] Here, an example of initial attachment of the support structure 10 to the curved plate member 12D of the steel pipe 12 will be described. As shown in Fig. 12, the second connecting member 22c is fixed to the base end portion 22b of the first arm member 22 by welding, and the second connecting member 24c is fixed to the base end portion 24b of the second arm member 24 by welding. Then, the second connecting member 22c of the first arm member 22 and the second connecting member 24c of the second arm member 24 are removably fixed to the relay member 32 (32A, 32B) with a bolt B1, a nut N1, and a tapered pin P. Meanwhile, with the curved plate member 12D placed at a predetermined position on the steel pipe 12 so that the central axis 12A extends vertically, stay members 18 and 20 are welded to the inside of the curved plate member 12D of the steel pipe 12. The strong-back members 26 and connecting members 28 corresponding to the stay members 18, 20 are then removably attached using bolts B1, nuts N1, and tapered pins P. This state is shown in FIG. 4. The central support portion 30 of the center member 16 is then positioned so as to extend along the central axis 12A of the steel pipe 12. An intermediate member 32 having arm members 22, 24 is attached to the central support portion 30. The distal ends 22a, 24a of the arm members 22, 24 are then placed on the corresponding stay members 18, 20. In this state, the distal end 22a of the first arm member 22 is welded to the strong-back member 26, and the distal end 24a of the second arm member 24 is welded to the connecting member 28. This determines the relative positions of the components of the support structure 10, allowing the curved plate member 12D to be positioned at a predetermined position on the steel pipe 12 with nearly ideal roundness. This also enables the support structure 10 to be disassembled and reassembled, and the curved plate member 12 to be transported independently.

[0034] The configuration of a portion of the support structure 10 having the above-described structure and the resulting effects will be described below.

[0035] The support structure 10 is used when manufacturing a steel pipe 12 by welding multiple curved plate materials 12D. The support structure 10 includes a center member 16 disposed inside the steel pipe 12, first stay members 18 provided on each of the curved plate materials 12D, the first stay members 18 being provided on each of the curved plate materials to be butt-welded, and multiple first arm members 22 removably attached to the center member 16 so as to extend from the center member 16 to a seam portion S where the curved plate materials 12D butt together, each of the first arm members 22 having a strong-back member 26 at its tip end 22a. The strong-back members 26 are removably attached so as to connect the first stay members 18 provided on the pair of curved plate materials 12D to be butt-welded. Therefore, the support structure 10 can be attached to and detached from multiple curved plate materials 12D with high reproducibility, making the support structure 10 suitable for transporting multiple curved plate materials 12D. Furthermore, with the support structure 10 configured as described above, the first stay member 18 of the curved plate material to be butt-welded can be connected using the first arm member 22 removably attached to the center member 16. Therefore, by using the support structure 10, when assembling and welding multiple curved plate materials 12D, the curved plate materials 12D can be appropriately positioned and held in their predetermined positions, thereby enabling the production of steel pipes 12 with higher precision. In this way, the support structure 10 can be used when welding multiple curved plate materials 12D to produce steel pipes 12 and may be referred to as, for example, an assembled structure.

[0036] In particular, in the support structure 10, the center member 16 is disposed so as to extend along the central axis 12A of the steel pipe 12. This allows the first arm members 22 to extend radially from the central axis 12A and more suitably support the curved plate material 12D as a radial member, thereby enabling the production of a steel pipe 12 with higher roundness.

[0037] Furthermore, in the support structure 10, the first arm member 22 is removably attached to each of the center member 16 and the first stay member 18 using a connecting member having a tapered shape, specifically a tapered pin P. With this configuration, by connecting the first arm member 22 to the center member 16 and the first stay member 18, the center member 16, the first arm member 22, and the first stay member 18 can be positioned more accurately relative to each other. This also further improves the reproducibility when the support structure 10 is repeatedly assembled and disassembled.

[0038] The center member 16 also includes a central support portion 30 that is disposed so as to extend along the central axis 12A of the steel pipe 12, and an intermediary member 32 that is attached to the central support portion 30 and on which a plurality of first arm members 11 are provided. This configuration makes it possible to divide the center member 16 into more than one portion, thereby further improving the transportability of the support structure 10. Note that the center member 16 is not limited to being configured to include and be divisible into the central support portion 30 and the intermediary member 32, but it is preferable that the center member 16 include the central support portion 30 and the intermediary member 32.

[0039] Furthermore, the relay member 32 includes a first relay member 32A on which a plurality of first arm members 22 are provided, and a second relay member 32B on which a plurality of first arm members 22 are provided, and the first relay member 32A is attached to the central support part 30 at a distance, particularly in this case, from the second relay member 32B in the direction of the central axis 12A. This makes it possible to use the support structure 10 to manufacture steel pipes 12 that are longer in the direction of the central axis 12A, i.e., in the axial direction. The number of relay members 32 in the support structure is not limited to two, and may be one, or three or more.

[0040] The support structure 10 further includes a second stay member 20 provided at the concavely curved portion 12C away from the end 12E of the curved plate material 12D, and a second arm member 24 extending from the center member 16 toward the second stay member 20. Use of the second arm member 24 can more effectively prevent or suppress unintended bending of the curved plate material 12D, thereby enabling the production of steel pipes 12 with higher precision. In particular, in the above embodiment, the second arm member 24 is provided on the center member 16 so as to extend radially from the central axis 12A of the steel pipe 12. This allows the production of steel pipes 12 with higher roundness. The second arm member 24 is removably provided on the center member 16 and removably attached to the second stay member 20. The support structure 10 can maintain high transportability even with the second arm member 24.

[0041] While typical embodiments of the present disclosure have been described above, the present disclosure is not limited thereto and various modifications are possible. Various substitutions and modifications are possible without departing from the spirit and scope of the present disclosure as defined by the claims of the present application.

[0042] For example, in the above embodiment, one support structure 10 includes two relay members 32A, 32B, but it may include only one relay member 32. Also, the support structure 10 may not include the second arm member 24. The support structure according to the present disclosure may have various configurations to enable welding of the steel pipes 12 with higher precision, particularly with improved roundness. [Explanation of symbols]

[0043] 10 Support structure 12 Steel pipe 12D curved plate 16 Center member 18 Stay member (first stay member) 20 Stay member (second stay member) 22 arm member (first arm member) 24 arm member (second arm member) 26 Strongback member 28 Connecting member 30 Center support 32 Relay parts P Tapered pin

Claims

1. A support structure used when manufacturing a steel pipe by welding a plurality of curved plate materials, a center member disposed inside the steel pipe; A first stay member provided on each of the curved plate materials, the first stay member being provided on each of the first curved plate material and the second curved plate material that are butt-welded; a plurality of first arm members detachably attached to the center member so as to extend from the center member to the butted portions of the curved plate members, each of the first arm members having a strong-back member at its distal end; and Equipped with The strong-back member is removably attached to connect the first stay member of the first curved plate member and the first stay member of the second curved plate member. Support structure.

2. The center member is disposed so as to extend along the central axis of the steel pipe. The support structure of claim 1 .

3. The first arm member is removably attached to the center member and the first stay member using a connecting member having a tapered shape. A support structure according to claim 1 or 2.

4. The center member is a central support portion disposed to extend along the central axis of the steel pipe; a relay member attached to the central support portion and on which a plurality of the first arm members are provided; Equipped with The support structure of claim 1 .

5. the relay member includes a first relay member on which a plurality of the first arm members are provided, and a second relay member on which a plurality of the first arm members are provided, the first relay member is attached to the central support portion so as to be shifted in the direction of the central axis from the second relay member; The support structure of claim 4.

6. a second stay member provided in a concave curved portion away from an end of the curved plate material in a circumferential direction of the curved plate material; a second arm member extending from the center member toward the second stay member; Further comprising: the second arm member is removably attached to the center member and is removably attached to the second stay member; A support structure according to claim 1 or 2.

Images