Method for manufacturing reinforced tube and reinforced tube

Abstract

The present invention provides a method for manufacturing a reinforced tube and a reinforced tube, wherein the method for manufacturing a reinforced tube can manufacture a highly rigid and lightweight reinforced tube with good working efficiency. The method comprises: a raised bead forming step, wherein a welding torch (30) is inserted into the interior of the tube (10) from an open end (11) of the tube (10), and a raised bead (20) is formed on at least a portion of the circumferential direction of the inner wall surface (12) of the tube (10) by brazing with a brazing filler metal or welding with a welding material; a reinforcing plate arranging step, wherein after the welding torch (30) is removed from the tube (10), a reinforcing plate (25) is inserted into the interior of the tube (10), and the reinforcing plate (25) is arranged in a manner connected to the raised bead (20); and a reinforcing plate welding step, wherein an edge portion (26) of the reinforcing plate (25) and at least a portion of the inner wall surface (12) of the tube (10) are fillet welded.

Description

Technical Field

[0001] The present invention relates to a method for producing a reinforcing tube and the reinforcing tube, and in particular to a method for producing a reinforcing tube suitable for a body frame for an automobile having a closed cross-sectional structure and the reinforcing tube. Background Art

[0002] Hollow tube structure is an ideal structural style that has both lightness and high rigidity. It is used as a component in various industries regardless of the raw materials such as steel, aluminum alloy, resin, concrete, etc. However, if the tube length becomes too large relative to the tube cross-sectional size, the rigidity decreases, so it is known to improve it by inserting reinforcing plates at appropriate intervals like "bamboo joints". Such reinforcing plates arranged perpendicular to the length direction are called various names such as bulkhead, diaphragm, and stiffener in various industries.

[0003] In the construction and civil engineering industries, it is known that Fig.16 As shown, the H-shaped steel 101 as a structural member is welded with reinforcing plates 102 at certain intervals to improve strength. In this structure, since the reinforcing plates 102 and the welding torch 30 can be freely inserted from the opening side, the reinforcing plates 102 can be fillet-welded with the weld metal 21, and even multiple reinforcing plates 102 can be easily welded.

[0004] However, if Fig.17A , Fig. 17B As shown, when the structural member is a pipe 111, although it is theoretically possible to insert the welding torch 30 from the open ends 113 on both sides for welding, it is difficult to position the reinforcing plate 112. In particular, if the pipe 111 is in a horizontal position, the position of the reinforcing plate 112 standing vertically is unstable, and positioning is actually very difficult.

[0005] like Fig.18 As shown, if the tube 111 is erected in the vertical direction, the reinforcing plate 112 becomes horizontal, so the insertion of the reinforcing plate 112 becomes easy. However, since the reinforcing plate 112 may fall due to gravity, it is still difficult to position the reinforcing plate 112. In addition, although the welding of the reinforcing plate 112 located at the lowest level can be handled by placing the reinforcing plate 112 on the positioning stand 115 inserted from the open end 113 of the lower surface, the positioning stand 115 cannot be used for the reinforcing plates 112 after the second piece arranged above the lowest level. If the positioning stand 115 is also applied to the reinforcing plates 112 after the second piece, the positioning stand 115 cannot be removed after welding. Therefore, it is substantially impossible to position the reinforcing plates 112 after the second piece, and multiple reinforcing plates 112 cannot be welded.

[0006] Patent Documents 1 and 2 describe that wall plates are welded to upper and lower and left and right side surfaces of a plurality of reinforcing plates called ribs or bulkheads to form a tubular structural member reinforced by the reinforcing plates.

[0007] In particular, Patent Document 1 states that by welding the welding parts located on the diagonal lines of multiple reinforcing plates at the same time, the heat input to the reinforcing plates can be suppressed and the influence of heat can be suppressed to a minimum. In addition, Patent Document 2 states that even if the reinforcing plates are arranged in an inclined state relative to the wall plates, the molten metal is evenly melted into each corner of the welding groove. Furthermore, Patent Document 3 states that a welding wire is inserted into the BOX column from a nozzle insertion hole formed in a skin plate of a BOX column, and a partition plate and a skin plate provided with a backing plate are electroslag welded in a non-melting nozzle manner to produce a BOX column reinforced with a partition plate. This welding method is generally referred to as an internal partition method, which is a high-cost method that requires a lot of effort and time, although it can obtain higher joint reliability.

[0008] In addition, Patent Document 4 further describes: a method for processing a metal plate into a cylindrical shape with a roughly circular or polygonal cross-section by press working, roll forming, etc. and joining the ends of the plate to each other by welding, caulking, etc., and for accurately arranging reinforcing parts such as isolation plates and reinforcements at specified positions inside the part.

[0009] Prior art literature

[0010] Patent Literature

[0011] Patent Document 1: Japanese Patent Publication No. 60-16312

[0012] Patent Document 2: Japanese Patent Publication No. 7-103634

[0013] Patent Document 3: Japanese Patent No. 4467364

[0014] Patent document 4: Japanese Patent No. 5412980. Summary of the invention

[0015] Problems to be solved by the invention

[0016] However, all previous technologies have problems such as low working efficiency and dimensional accuracy, loss of homogeneity, and increased weight due to reinforced parts, and there is room for improvement.

[0017] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a method for manufacturing a reinforcing tube capable of manufacturing a highly rigid and lightweight reinforcing tube with good work efficiency, and a highly rigid and lightweight reinforcing tube.

[0018] Means used to solve problems

[0019] Therefore, the above-mentioned object of the present invention is achieved by the following structure [1] regarding the manufacturing method of the reinforced tube.

[0020] [1] A method for manufacturing a reinforced tube, wherein at least one reinforcing plate made of the same material as the tube is welded inside a tube made of metal at a position intersecting with the longitudinal direction of the tube, the method comprising: a raised bead forming step, wherein a welding torch is inserted into the tube from an open end thereof, and a raised bead is formed on at least a portion of the circumferential direction of the inner wall surface of the tube by brazing with a brazing filler metal or welding with a welding material; a reinforcing plate arranging step, wherein after removing the welding torch from the tube, the reinforcing plate is inserted into the tube and arranged so as to be in contact with the raised bead; and a reinforcing plate welding step, wherein an edge portion of the reinforcing plate is fillet-welded to at least a portion of the inner wall surface of the tube.

[0021] In addition, the above-mentioned object of the present invention is achieved by means of the following [2] structure related to the reinforcement pipe.

[0022] [2] A reinforced pipe, wherein at least one reinforcing plate made of the same material as the pipe is welded inside a pipe made of metal at a position intersecting with the longitudinal direction of the pipe, and a raised weld bead is formed on at least a portion of the circumferential direction of the inner wall surface of the pipe at a position adjacent to the reinforcing plate on the opposite side to the side where weld metal is formed with respect to the reinforcing plate.

[0023] Effects of the Invention

[0024] According to the manufacturing method of the reinforcement tube of the present invention, a highly rigid and lightweight reinforcement tube can be manufactured with good work efficiency. In addition, according to the reinforcement tube of the present invention, a highly rigid and lightweight reinforcement tube can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1A It is a perspective view showing the first half of the process of the method for manufacturing the reinforcement tube according to the first embodiment of the present invention.

[0026] Figure 1B It is a perspective view showing the second half of the process of the method for manufacturing the reinforcement tube according to the first embodiment of the present invention.

[0027] Figure 2 This is an enlarged cross-sectional view of a welded portion where a reinforcing plate is welded to the inner wall surface of a pipe.

[0028] Figure 3 It is an enlarged cross-sectional view of a welded portion where a reinforcing plate having a レ-shaped groove is welded to the inner wall surface of a pipe.

[0029] Figure 4A This is an enlarged cross-sectional view showing a state where weld metal falls from a gap between a reinforcing plate and an inner wall surface of a pipe.

[0030] Figure 4B This is an enlarged cross-sectional view showing a state where burn-through is prevented by a raised weld bead.

[0031] Figure 5 This is a cross-sectional view showing a state in which a reinforcing plate is welded to the inner wall surface of a horizontally arranged pipe.

[0032] Figure 6 This is a cross-sectional view showing a state in which a reinforcing plate is welded to the inner wall surface of a pipe arranged at an oblique angle.

[0033] Fig. 7A It is a perspective view showing the first half of the process of the method for manufacturing the reinforcement tube according to the second embodiment of the present invention.

[0034] Figure 7B It is a perspective view showing the second half of the process of the method for manufacturing the reinforcement tube according to the second embodiment of the present invention.

[0035] Figure 8 It is a perspective view of a reinforcement pipe according to a third embodiment of the present invention.

[0036] Fig. 9A It means in Figure 8 A cross-sectional view of a state in which a second reinforcing plate is placed, positioned, and welded to a first reinforcing plate in the reinforcing pipe shown.

[0037] Fig. 9B It means in Figure 8 The cross-sectional view shows a state in which a second reinforcing plate is placed and positioned on weld metal to which a first reinforcing plate is welded in a reinforcing pipe.

[0038] Fig. 10A It is a plan view showing an example of the shape of a raised weld bead.

[0039] Fig. 10B It is a side view showing an example of the shape of a raised weld bead.

[0040] Fig. 10C It is a plan view schematically showing the deviation between the planned arrangement position of the reinforcing plate and the position where the reinforcing plate is actually arranged.

[0041] Fig. 10D It is a plan view showing a preferred method for forming a raised weld bead.

[0042] Fig.11A It is a plan view showing an example of the shape of a raised weld bead.

[0043] Fig. 11B It is a side view showing an example of the shape of a raised weld bead.

[0044] Fig. 11C It is a plan view showing a more preferable method of forming a raised bead.

[0045] Fig.12 It is a cross-sectional view of each tube having a closed cross section.

[0046] Fig.13 is a cross-sectional view of each tube having another closed cross section.

[0047] Fig.14 is a cross-sectional view of each tube having yet another closed cross section.

[0048] Fig.15 This is a perspective view of a side sill of a vehicle to which a reinforcement plate is welded by the method for manufacturing a reinforcement pipe according to the present invention.

[0049] Fig.16 This is a perspective view showing the process of welding a reinforcing plate to an H-shaped steel using a conventional welding method.

[0050] Fig.17A It is a perspective view showing a state where a reinforcing plate is inserted into a horizontally arranged pipe.

[0051] Fig. 17B This is a cross-sectional view showing a state in which a reinforcing plate is welded to the inner wall of a horizontally arranged pipe by a conventional welding method.

[0052] Fig.18 This is a cross-sectional view showing a state in which a reinforcing plate is welded to the inner wall of a vertically arranged pipe by a conventional welding method. DETAILED DESCRIPTION

[0053] Hereinafter, each embodiment of the method for producing a reinforced tube according to the present invention will be described in detail with reference to the drawings.

[0054] <First Embodiment>

[0055] Figure 1A is a perspective view showing the first half of the process of the method for manufacturing the reinforcement tube according to the first embodiment. Figure 1B 1 is a perspective view showing the second half of the manufacturing method of the reinforcement tube according to the first embodiment. Figure 2 This is an enlarged cross-sectional view of a welded portion where a reinforcing plate is welded to the inner wall surface of a pipe.

[0056] The method for manufacturing a reinforced tube according to the present embodiment is a method for obtaining a reinforced tube by welding a plurality of reinforcing plates made of the same material as the tube in a direction intersecting the longitudinal direction (axial direction) of a metal tube such as steel, aluminum alloy, or copper alloy.

[0057] The method for manufacturing the reinforced tube according to the first embodiment is first as follows. Figure 1A As shown, in step 1, a metal tube (in Figure 1A In the embodiment shown, the square tube 10 is arranged with its axial direction facing upward in the vertical direction. Thus, one open end 11 of the tube 10 is opened upward.

[0058] In step 2, the welding torch 30 is inserted into the interior of the pipe 10 from the upper open end 11 of the pipe 10, and the molten metal is raised and stacked on at least a portion of the circumference of the inner wall surface 12 of the pipe 10 by means of metal arc welding or non-metal arc welding using a molten material, or laser welding to form a raised weld bead 20 (raised weld bead forming step).

[0059] Here, the position where the raised bead 20 is formed is the position where the reinforcing plate 25 described later is provided. Figure 1A As shown in step 2, when the plurality of raised weld beads 20 are formed by being divided into a plurality of parts and welded by raised stacking, it is preferred that the positions of the raised weld beads 20 are in the same plane so that the reinforcing plate 25 is stable when placed on the raised weld beads 20. Figure 1A In the embodiment, the raised bead 20 is provided at one location on each of the four sides of the inner wall surface 12 of the square tube, for a total of four locations, but it may also be provided at one location on each of the inner wall surfaces 12 on two opposing sides, for a total of two locations, or may be formed over the entire circumference.

[0060] In addition, the raised bead 20 is not particularly limited as long as it has a strength capable of stably supporting the placed reinforcing plate 25, and the raised bead 20 may be formed by brazing (brazing) using a brazing filler metal instead of cladding. That is, the raised bead 20 may be formed by MIG spot welding (MIG brazing) using a welding torch 30 while supplying a brazing filler metal. As the MIG spot welding technique, either normal MIG welding or CMT (Cold Metal Transfer) welding may be used.

[0061] In step 3, after the welding torch 30 is removed, i.e., pulled out from the pipe 10, the reinforcing plate 25 is inserted into the pipe 10 and placed so as to be in contact with the raised bead 20. At this time, the reinforcing plate 25 is placed only on the raised bead 20 and is not joined to the pipe 10 (reinforcing plate placement step).

[0062] In addition, the reinforcing plate 25 and the pipe 10 are preferably made of the same material. That is, when the pipe 10 is made of iron or an iron alloy, the reinforcing plate 25 is preferably also made of iron or an iron alloy, and when the pipe 10 is made of aluminum or an aluminum alloy, the reinforcing plate 25 is preferably also made of aluminum or an aluminum alloy. Furthermore, when the pipe 10 is made of copper or a copper alloy, the reinforcing plate 25 is preferably also made of copper or a copper alloy.

[0063] The reinforcing plate 25 can be freely dropped from above in the reinforcing plate arranging process, but it is also possible to carefully place the reinforcing plate 25 while holding it using a magnet if the reinforcing plate 25 is made of steel, or using a vacuum adsorption device if the reinforcing plate 25 is made of stainless steel or non-ferrous material. In addition, the shape of the reinforcing plate 25 is similar to the shape of the hole of the pipe 10, and is preferably set to a size slightly smaller than the hole of the pipe 10. This makes the reinforcing plate arranging operation easy.

[0064] In step 4, the welding torch 30 is inserted into the interior of the pipe 10 from the open end 11 of the pipe 10 again, and the edge portion 26 of the reinforcing plate 25 and the inner wall surface 12 of the pipe 10 are fillet welded, for example, by arc welding or laser welding, at a position where the reinforcing plate 25 intersects with the longitudinal direction of the pipe 10, i.e., at a plurality of positions including the peripheral surface facing the edge portion 26 of the reinforcing plate 25, or very near them, among the reinforcing plate 25 placed and positioned on the raised weld bead 20 and the inner wall surface 12 of the pipe 10 (reinforcing plate welding step).

[0065] In addition, it is simple and reasonable to use the same welding torch 30 as the welding torch 30 used when forming the uplift weld bead 20 in step 2 as the uplift weld bead forming process as the welding torch 30 used in step 4 as the reinforcement plate welding process, but another type of welding torch 30 may be used as needed.

[0066] Therefore, if Figure 2 As shown, one reinforcing plate 25 is welded to the inner wall surface 12 of the pipe 10 via the weld metal 21. The raised bead 20 and the weld metal 21 formed in the raised bead forming step do not necessarily need to be melted.

[0067] The weld metal 21 for welding the edge portion 26 of the reinforcing plate 25 to the inner wall surface 12 of the pipe 10 may be provided intermittently in the circumferential direction of the pipe 10. However, in order to firmly weld the reinforcing plate 25 to the pipe 10, the weld portion is as long as possible, and is preferably formed over the entire circumference of the pipe 10. In addition, in order to firmly weld, it is preferred to adjust the current, voltage, welding speed, etc. during welding so that the cross section of the weld portion is deeply melted.

[0068] In addition, the edge portion 26 of the reinforcing plate 25 may also be formed at a right angle to the surface of the reinforcing plate 25, but Figure 3As shown, when the thickness t of the reinforcing plate 25 is relatively thick, in order to facilitate increasing the penetration depth, it is preferred to chamfer the edge portion 26 of the reinforcing plate 25 to form a レ-shaped groove between the reinforcing plate 25 and the inner wall surface 12 of the pipe 10 and perform welding.

[0069] In addition, if Figure 4A As shown, when the reinforcing plate 25 is welded to the inner wall surface 12, the welding heat input may be too much, and if a gap is generated between the edge portion 26 of the reinforcing plate 25 and the inner wall surface 12 of the pipe 10 or the edge portion 26 of the reinforcing plate 25 melts, the weld metal 21 may fall through the generated gap. Figure 4B As shown, if the raised bead 20 is formed over the entire circumference of the pipe 10 in advance in step 2, the raised bead 20 serves as a receiving portion and can prevent burn-through, which is more preferable.

[0070] Next, a process of welding the second reinforcing plate 25 to the inner wall surface 12 of the pipe 10 will be described.

[0071] When the welding torch used in the uplift bead forming step and the welding torch used in the reinforcement plate welding step are different welding torches (for example, when the uplift bead 20 is formed by brazing), the welding torch 30 used in the welding of the first reinforcement plate 25 is pulled out from the pipe 10, and the welding torch 30 used in the uplift bead forming step is inserted into the pipe 10, and the uplift bead 20 is formed in the same manner as step 2 at the position where the second reinforcement plate 25 is provided. That is, between the welding of the first reinforcement plate 25 and the welding of the second reinforcement plate 25, the welding torch replacement operation is required.

[0072] On the other hand, Figure 1B As shown, when the welding torch used in the raised bead forming process is the same as the welding torch used in the reinforcement plate welding process, in step 5, the welding torch 30 is not pulled out after the welding operation of the first reinforcement plate 25 is completed, but it is only necessary to move it to the position (height) where the second reinforcement plate 25 is set, and the second level raised bead 20 is formed in the same way as step 2.

[0073] In step 6 , similarly to step 3 , after the welding torch 30 is pulled out from the pipe 10 , the reinforcing plate 25 is inserted into the pipe 10 and placed on the second-stage raised bead 20 .

[0074] In step 7, similarly to step 4, the welding torch 30 is again inserted into the interior of the tube 10 from the open end 11 of the tube 10, and the edge portion 26 of the reinforcing plate 25 and the inner wall surface 12 of the tube 10 are fillet-welded at the intersection of the reinforcing plate 25 and the inner wall surface 12 of the tube 10 or at a position very close thereto, for example, by means of arc welding or laser welding.

[0075] In step 8 , the welding torch 30 is pulled out from the pipe 10 to which the second reinforcing plate 25 is welded, and the welding of the second reinforcing plate 25 is completed.

[0076] Thereafter, the operations of steps 5 to 8 are repeated as needed, and the third and subsequent reinforcing plates 25 are welded one by one at predetermined positions, thereby manufacturing a highly rigid and lightweight reinforcing tube 100 with enhanced strength due to the plurality of reinforcing plates 25 .

[0077] The most important point of the present technology is that in the uplift bead forming step (step 2, step 5), the uplift bead 20 formed of weld metal is provided in advance on the inner wall surface 12 of the pipe 10 where the reinforcing plate 25 is provided before the reinforcing plate 25 is provided.

[0078] In this case, the production efficiency is highest when the pipe 10 is vertically erected. Therefore, the ridge bead forming step is a horizontal welding performed on the vertical wall, so it is preferably performed under low current conditions to prevent the molten metal from dripping.

[0079] The raised weld bead 20 may be either a plurality of point-shaped raised bead or a full-circle raised bead. However, if the welding heat input is too much during the reinforcing plate welding process or the gap between the inner wall surface 12 and the edge portion 26 of the reinforcing plate 25 is large, burn-through is likely to occur. Therefore, in order to prevent burn-through, it is preferably set to a full-circle raised bead.

[0080] As described above, according to the method for manufacturing a reinforced tube according to the present embodiment, it is possible to manufacture the reinforced tube 100 having a plurality of reinforcing plates 25 welded inside the tube 10 to enhance strength, which has been difficult to manufacture so far, with a simple device and structure.

[0081] Furthermore, the method for manufacturing the reinforcement tube according to the present embodiment has the following advantages.

[0082] (1) Small equipment investment.

[0083] (2) The operating cost is relatively low.

[0084] (3) No need to cut or drill holes in the pipe.

[0085] (4) If a welding robot is combined with a material handling robot, almost all processes can be automated.

[0086] (5) Since the reinforcing plate can be welded over almost the entire cross section, there is no anisotropy with respect to compression and tension, and the rigidity is high.

[0087] (6) High rigidity can be achieved with minimal weight increase.

[0088] (7) It will not deteriorate the original linearity of the tube.

[0089] As described above, the bulge bead forming step, the reinforcing plate arranging step, and the reinforcing plate welding step are performed with the open end 11 of the pipe 10 directed vertically upward at the highest working efficiency.

[0090] However, if the pipe 10 cannot be erected vertically upward due to space limitations of a building or the like, the pipe 10 may be erected vertically upwardly. Figure 5 , Figure 6 As shown, the pipe 10 is placed in a horizontal direction or in a direction inclined relative to the horizontal direction in its longitudinal direction. However, if the pipe 10 is placed in a horizontal direction or in a direction inclined relative to the horizontal direction in its longitudinal direction, welding operations such as vertical welding and overhead welding with a high degree of welding difficulty are required. Therefore, it is preferable to carefully design the welding so that the front end of the welding torch 30 is always facing downward while rotating the pipe 10 around its axis by a rotating roller device (rotating mechanism) not shown in the figure.

[0091] In addition, Figure 5 When the pipe 10 is placed in a horizontal direction in the longitudinal direction as shown in FIG. 1 , the reinforcing plate 25 inserted in the pipe 10 is easy to fall down. Therefore, it is preferable to perform the ridge bead forming step, the reinforcing plate arranging step, and the reinforcing plate welding step while pressing the reinforcing plate 25 with the pressing device 35 which serves as a falling prevention portion of the reinforcing plate 25. Figure 6 As shown, if the pipe 10 is placed in a state where the longitudinal direction is inclined obliquely, the reinforcing plate 25 abuts against the raised bead 20 by its own weight, so that the pressing device 35 is no longer required, and the welding operation becomes easy.

[0092] <Second Embodiment>

[0093] In the first embodiment, the case where welding is performed in a manner in which the plane of the reinforcing plate 25 is perpendicular to the longitudinal direction of the tube 10 is described as an example, but the reinforcing plate 25 does not necessarily need to be perpendicular to the longitudinal direction of the tube 10, and can also be welded while being inclined at an acute angle or an obtuse angle relative to the longitudinal direction of the tube 10.

[0094] Fig. 7A is a perspective view showing the first half of the process of the method for manufacturing a reinforcement tube according to the second embodiment. Figure 7B 1 is a perspective view showing the second half of the manufacturing method of the reinforcement tube according to the second embodiment. Figure 7BAs shown, the reinforcing plate 25 of the reinforcing tube 100A of the second embodiment is welded with its reinforcing plate 25 tilted relative to the longitudinal direction of the tube 10. The other structures and functions of the reinforcing tube 100A are the same as those of the reinforcing tube 100 of the first embodiment, so the same reference numerals or corresponding reference numerals are given to the same parts, and the description is simplified or omitted.

[0095] In step 1 , the reinforcing pipe 100A of the present embodiment is arranged with its axial direction directed vertically upward so that the open end 11 of the pipe 10 faces upward.

[0096] In step 2, the welding torch 30 is inserted into the pipe 10, and the uplift bead 20 is formed by tilting it relative to the longitudinal direction of the pipe 10 while controlling the movement of the welding torch 30 (uplift bead forming step). The uplift bead 20 is preferably formed in the same plane (inclined surface) so that when the reinforcing plate 25 is placed on the uplift bead 20, the reinforcing plate 25 is stably tilted.

[0097] In step 3, after the welding torch 30 is pulled out from the pipe 10, the reinforcing plate 25 is inserted into the pipe 10 and is placed obliquely on the inclined raised bead 20 (reinforcing plate placement step).

[0098] In step 4, the welding torch 30 is inserted into the interior of the pipe 10 again, and the edge portion 26 of the reinforcing plate 25 and the inner wall surface 12 of the pipe 10 are welded by means of the weld metal 21 at a position where the reinforcing plate 25 intersects with the longitudinal direction of the pipe 10, that is, at a plurality of positions including the peripheral surface facing the edge portion 26 of the reinforcing plate 25, or very close thereto, among the reinforcing plate 25 placed and positioned on the raised weld bead 20 and the inner wall surface 12 of the pipe 10 (reinforcing plate welding step).

[0099] In step 5 , after the welding torch 30 is moved to the position where the second reinforcing plate 25 is provided, the second raised bead 20 is formed while being inclined with respect to the longitudinal direction of the pipe 10 while controlling the movement of the welding torch 30 in the same manner as in step 2 .

[0100] In step 6 , similarly to step 3 , after the welding torch 30 is pulled out from the pipe 10 , the second reinforcing plate 25 is placed obliquely on the second-stage raised bead 20 .

[0101] In step 7, similarly to step 4, the welding torch 30 is again inserted into the interior of the tube 10, and the edge portion 26 of the reinforcing plate 25 and the inner wall surface 12 of the tube 10 are fillet welded at the intersection of the inclined reinforcing plate 25 and the inner wall surface 12 of the tube 10 or very close thereto.

[0102] In step 8 , the welding torch 30 is pulled out from the pipe 10 to which the second reinforcing plate 25 is welded, and the welding of the second reinforcing plate 25 is completed.

[0103] Thereafter, the operations of steps 5 to 8 are repeated as needed, and the third and subsequent reinforcing plates 25 are welded one by one at specified positions, thereby manufacturing a highly rigid and lightweight reinforced tube 100A in which a plurality of reinforcing plates 25 are obliquely welded to the inner wall surface 12 of the tube 10 to be reinforced.

[0104] <Third Embodiment>

[0105] Figure 8 2 is a perspective view of a reinforcement tube according to the third embodiment. Figure 8 As shown in FIG. 1 , the reinforced tube 100B of the third embodiment is welded with a plurality of reinforced plates 25 that are tilted obliquely with respect to the axis of the tube 10 so that their directions are opposite at each stage. Here, the manufacturing method of the reinforced tube of the third embodiment is characterized in that, in the reinforcing plate arrangement step, the next reinforcing plate 25 is arranged so as to be in contact with the reinforcing plate 25 welded in the previous reinforcing plate welding step or the weld metal 21 formed in the previous reinforcing plate welding step. In addition, the welding method of the reinforcing plate 25 is the same as that of the reinforced tube 100A of the second embodiment, except that the inclination angle of the ridge weld bead 20 with respect to the axis of the tube 10 is different, so the description thereof is omitted.

[0106] In the case of the reinforcing tube 100B of the third embodiment, Fig. 9A As shown in the figure, the reinforcement plate 25a welded at the lower level (previous) is used as the foothold and positioning of the upper level (next) reinforcement plate 25b, and the raised weld bead 20 for the upper level reinforcement plate 25b is omitted and the upper level reinforcement plate 25b is welded. Fig. 9B As shown, the upper (next) reinforcing plate 25b is positioned by using the weld metal 21 to which the lower (previous) reinforcing plate 25a is welded as a foothold, and the raised bead 20 for the upper reinforcing plate 25b is omitted.

[0107] In either case, the reinforcing plate 25a welded at the lower stage or the weld metal 21 to which the lower reinforcing plate 25a is welded functions to prevent burn-through in the reinforcing plate welding process, so a part of the overlay welding can be omitted.

[0108] Next, a method for forming a raised bead which is more preferable in the above-mentioned first to third embodiments will be described below.

[0109] like Fig. 10A and Fig. 10BAs shown in FIG. 1 , when the welding torch is moved from the starting portion 40 where the formation of the uplift bead 20 starts toward the ending portion 41 in the direction indicated by the arrow 42 to form the uplift bead 20, the starting portion 40 often has a three-dimensionally bulging shape. This is because, at the time when the formation of the uplift bead 20 starts, the welding progress speed is slow relative to the supply speed of the welding material, and the volume of the molten pool inevitably increases.

[0110] Furthermore, if the raised bead 20 is formed in a shape in which the starting portion 40 is raised, Fig. 10C As shown, an angle deviation 45 occurs between the planned position (planned arrangement position 43 ) at which the reinforcing plate 25 is to be arranged and the position 44 at which the reinforcing plate 25 is actually arranged.

[0111] Therefore, in the process of forming the raised bead in step 2, it is preferable to form the raised bead 20 so that the tangent line 46 of the raised bead 20 to the reinforcing plate 25 coincides with the predetermined arrangement position 43 of the reinforcing plate 25. The tangent line 46 of the raised bead 20 to the reinforcing plate 25 is a line where the surface (lower surface) of the reinforcing plate 25 on the raised bead 20 side intersects the inner wall surface 12 of the pipe 10 when the reinforcing plate 25 is inserted and arranged from the open end 11 side of the pipe 10 after the raised bead 20 is formed. Fig. 10C As shown in FIG. 1 , when the reinforcing plate 25 is disposed, when the reinforcing plate 25 and the raised bead 20 are in contact at a plurality of points (e.g., contact points 47a and 47b), a line connecting the contact points 47a and 47b may be used as the tangent line 46. Furthermore, when the reinforcing plate 25 and the raised bead 20 are in contact with a line, the line may be used as the tangent line 46.

[0112] Thus, the position 44 where the reinforcing plate 25 is actually arranged coincides with the tangent line 46, so if the raised bead 20 is formed so that the tangent line 46 coincides with the planned arrangement position 43, the reinforcing plate 25 can be arranged at a desired position. In addition, the tangent line 46 and the planned arrangement position 43 do not necessarily have to be completely consistent. For example, in the case where a slight deviation is allowed between the planned arrangement position 43 and the position 44 where the reinforcing plate 25 is actually arranged, there may be a slight deviation between the tangent line 46 and the planned arrangement position 43.

[0113] As a specific method for forming the raised bead 20 so that the tangent line 46 coincides with the predetermined arrangement position 43, the following can be cited. Fig. 10DAs shown in FIG. 1 , in the uplift bead forming step, a position away from the predetermined arrangement position 43 of the reinforcing plate 25 in the direction opposite to the open end 11 of the pipe 10 is set as the starting portion 48 to start the formation of the uplift bead 20. Then, it is preferable to move the welding torch in the circumferential direction of the inner wall surface 12 of the pipe 10 while approaching the predetermined arrangement position 43 of the reinforcing plate 25. However, if the tip of the welding torch is aligned with the predetermined arrangement position and is moved in the circumferential direction, the tangent line on the open end 11 side of the obtained uplift bead 20 does not coincide with the predetermined arrangement position 43, so it is preferable to appropriately adjust the position of the welding torch.

[0114] When the formation of the ridge weld bead 20 is completed, the supply of the welding wire and the welding rod is generally stopped, while the molten pool is pulled in the opposite direction of the advancing direction by the surface tension. Fig.11A and Fig. 11B As shown in FIG. 1 , the volume of the end portion 41 decreases and the end portion 41 often has a thin bead shape. In the case of such a shape, although there is no adverse effect on the positioning of the reinforcing plate 25, due to the inevitable control of the welding machine model or the setting of the welding conditions, even if the supply of the welding material is stopped, the arc may not be stopped immediately and may become a long arc. Since the arc is a roughly conical shape in a microscopic sense, the range of the arc is expanded in the inner wall surface 12 of the pipe 10. In this case, the volume of the molten pool at the end portion 41 is small, but it is in an expanded shape. Although it is not as large as the start portion 40, it may be a bulging shape when viewed from above.

[0115] In such a case, the position of the reinforcing plate 25 may become unstable, so it is preferable to move the welding torch along the circumferential direction of the inner wall surface 12 of the pipe 10 while forming the raised weld bead, and then move the welding torch away from the opening end 11 to end the welding process. Fig. 11C As shown in FIG. 1 , it is preferable to set the position away from the planned arrangement position 43 of the reinforcing plate 25 in the opposite direction to the open end 11 of the pipe 10 as the end portion 49 to end the formation of the raised bead 20. Thus, even if the end portion 49 is a bulging shape, the reinforcing plate 25 can be arranged at a desired position without affecting the position where the reinforcing plate 25 is arranged.

[0116] When the raised bead 20 is formed by the preferred forming method as described above, the start portion (starting end portion) 48 and the end portion (terminating end portion) 49 of the obtained raised bead 20 are shaped so as to be away from the position where the reinforcing plate 25 is arranged in the direction opposite to the opening end 11 side of the pipe 10. In addition, depending on various conditions, only one of the start portion 48 and the terminating end portion 49 may affect the predetermined arrangement position 43, so the end portion of the start portion 48 and the terminating end portion 49 that affects the predetermined arrangement position 43 may be shaped so as to be away from the position of the reinforcing plate 25.

[0117] The first to third embodiments of the present invention and a preferred method for forming a raised bead have been described in detail above.

[0118] In the above description, a square tube with a rectangular cross section and a round tube with a round cross section are described as the tube 10, but the invention is not limited to square tubes and round tubes, and can be applied to tubes with any cross-sectional shape. Fig.12 As shown, in addition to the circular tube 10A and the square tube 10B, a hexagonal tube 10C may also be used.

[0119] In addition, if Fig.13 As shown, it can also be a hexagonal aluminum extrusion material 10D with ribs 10a, a hexagonal tube 10E with ribs formed by welding the ribs 10c of two pressure-formed products formed into a ribbed U-shape by pressure forming, or a hexagonal tube 10F with ribs provided with ribs 10e by forming a circular tube by hydraulic forming, extrusion processing, etc.

[0120] Furthermore, if Fig.14 As shown, it can also be applied to an asymmetrical tube 10G formed by welding a so-called hat-shaped part formed by pressure and a flat plate, a tube 10H such as an aluminum extruded material with multiple holes, and a ribbed hexagonal tube 10I formed by sandwiching a flat plate between two hat-shaped parts and welding them.

[0121] In any of the tubes 10A to 10I, it is preferable that the reinforcing plate 25 used has a similar shape slightly smaller than the hole of each tube 10A to 10I and is made of the same material as that of each tube 10A to 10I.

[0122] As a structure in which a plurality of bamboo-shaped reinforcing plates 25 are provided inside such a metal pipe 10, for example, Fig.15As shown, it is preferably applicable to a member called a rocker or a side sill 15, which is one of the frame members of the automobile body. By arranging and welding a plurality of reinforcing plates 25 at appropriate intervals inside the rocker or the side sill 15, it is possible to achieve high rigidity and light weight. Thus, it is possible to take into account both the improvement in fuel consumption due to the reduction in vehicle weight and the protection of passengers during a side collision, which are generally of opposite natures. Furthermore, the above-mentioned structure can also be applied to frame members for construction, and can be made into a frame member that is high in strength and light in weight, which helps to improve workability.

[0123] In addition, the present invention is not limited to the above-mentioned embodiments, and can be appropriately modified, improved, etc. For example, in the above-mentioned embodiment, the inner wall surface of the tube and the reinforcing plate are welded to form a reinforced tube, but brazing using brazing filler metal may be used instead of welding.

[0124] As described above, the following matters are disclosed in this specification.

[0125] (1) A method for manufacturing a reinforced tube, wherein at least one reinforcing plate made of the same material as the tube is welded inside a tube made of metal at a position intersecting with the longitudinal direction of the tube, the method comprising: a raised bead forming step, in which a welding torch is inserted into the tube from an open end thereof, and a raised bead is formed on at least a portion of the circumferential direction of the inner wall surface of the tube by brazing with a brazing filler metal or welding with a welding material; a reinforcing plate arranging step, in which, after removing the welding torch from the tube, the reinforcing plate is inserted into the tube and arranged so as to be in contact with the raised bead; and a reinforcing plate welding step, in which an edge portion of the reinforcing plate is fillet-welded to at least a portion of the inner wall surface of the tube.

[0126] According to this structure, a highly rigid and lightweight reinforcing pipe can be manufactured with good work efficiency.

[0127] (2) In the method for manufacturing a reinforced pipe according to (1), the reinforcing plate welding step is performed by inserting the welding torch used in the bump bead forming step again into the pipe from the open end of the pipe.

[0128] According to this configuration, by reusing the welding torch used in the bump bead forming step in the reinforcing plate welding step, a simple and rational method for manufacturing the reinforcing pipe can be provided.

[0129] (3) In the method for manufacturing a reinforced pipe according to (1) or (2), the raised bead is formed so as to be inclined with respect to the longitudinal direction of the pipe.

[0130] According to this structure, a highly rigid and lightweight reinforcing pipe can be manufactured with good work efficiency.

[0131] (4) The method for manufacturing a reinforced tube according to any one of (1) to (3), wherein the raised bead forming step, the reinforcing plate arranging step, and the reinforcing plate welding step are repeatedly performed according to the number of the reinforcing plates.

[0132] According to this structure, a plurality of reinforcing plates can be welded inside the pipe, and a reinforced pipe reinforced by a plurality of reinforcing plates can be manufactured with good work efficiency.

[0133] (5) In the method for manufacturing a reinforcing tube as described in (4), in the reinforcing plate arrangement step, the next reinforcing plate is arranged in such a manner as to be in contact with the reinforcing plate previously welded in the reinforcing plate welding step or with the weld metal previously formed in the reinforcing plate welding step.

[0134] According to this structure, the raised bead for arranging the next reinforcing plate can be omitted, and the reinforcing pipe can be manufactured with higher working efficiency.

[0135] (6) In the method for manufacturing a reinforced tube according to any one of (1) to (5), the edge portion of the reinforcing plate is chamfered, and a groove is formed between the reinforcing plate and the inner wall surface of the tube in the reinforcing plate welding step.

[0136] According to this configuration, even if the reinforcing plate has a large plate thickness, the penetration depth can be increased and the reinforcing plate can be firmly welded to the inner wall surface of the pipe.

[0137] (7) In the method for producing a reinforced tube according to any one of (1) to (6), the raised bead is formed over the entire circumference of the tube.

[0138] According to this configuration, the raised bead formed over the entire circumference of the pipe serves as a receiving portion, and burn-through can be prevented.

[0139] (8) In the method for manufacturing a reinforced tube according to any one of (1) to (7), the raised bead forming step, the reinforcing plate arranging step, and the reinforcing plate welding step are performed with the tube arranged with the open end facing vertically upward.

[0140] According to this structure, the plurality of reinforcing plates can be welded to the inner wall surface of the pipe with particularly good work efficiency.

[0141] (9) The method for producing a reinforced tube according to any one of (1) to (8), wherein the cross-sectional shape of the tube perpendicular to the longitudinal direction is a closed cross-sectional shape such as a circle, an ellipse, or a polygon.

[0142] According to this configuration, it is possible to manufacture a reinforced pipe having an arbitrary closed cross-sectional shape and a reinforcing plate welded to the inner wall surface of the pipe.

[0143] (10) In the method for manufacturing a reinforced tube according to any one of (1) to (9), in the raised bead forming step, the raised bead is formed so that a tangent line of the raised bead to the reinforcing plate coincides with a predetermined position for arranging the reinforcing plate.

[0144] According to this structure, the positioning accuracy of the reinforcing plate can be improved.

[0145] (11) In the method for manufacturing a reinforced tube as described in (10), in the aforementioned raised weld bead forming step, the formation of the aforementioned raised weld bead is started from a position away from a predetermined position for configuring the aforementioned reinforcing plate in a direction opposite to the open end of the aforementioned tube, and the aforementioned welding torch is moved along the circumferential direction of the inner wall surface of the aforementioned tube while approaching the position for configuring the aforementioned reinforcing plate.

[0146] According to this structure, the positioning accuracy of the reinforcing plate can be improved by an easy method.

[0147] (12) In the method for manufacturing a reinforced tube as described in (10) or (11), in the step of forming the raised weld bead, after the raised weld bead is formed while the welding torch is moved circumferentially along the inner wall surface of the tube, the formation of the raised weld bead is terminated at a position away from a predetermined position for arranging the reinforcing plate in a direction opposite to the opening end of the tube.

[0148] According to this structure, the positioning accuracy of the reinforcing plate can be further improved by an easy method.

[0149] (13) A reinforced pipe, wherein at least one reinforcing plate made of the same material as the pipe is welded inside a pipe made of metal at a position intersecting with the longitudinal direction of the pipe, and a raised weld bead is formed on at least a portion of the circumferential direction of the inner wall surface of the pipe at a position adjacent to the reinforcing plate on the side opposite to the side where weld metal is formed with respect to the reinforcing plate.

[0150] According to this structure, since the reinforcement plate is stably positioned, a highly rigid and lightweight reinforcement pipe can be obtained.

[0151] (14) In the reinforced pipe according to (13), the raised bead is formed over the entire circumference of the pipe.

[0152] According to this configuration, the raised bead formed over the entire circumference of the pipe serves as a receiving portion, and burn-through can be prevented.

[0153] (15) In the reinforced pipe described in (13) or (14), the raised weld has a starting end and a terminal end, and at least one of the starting end and the terminal end is away from the position where the reinforcing plate is arranged in the direction opposite to the opening end side of the pipe.

[0154] According to this structure, a reinforcement pipe having a reinforcement plate at a desired position can be obtained.

[0155] (16) The reinforcing pipe according to any one of (13) to (15) is used for a frame member for an automobile or a building.

[0156] According to this structure, the strength of the frame member for automobiles or buildings can be enhanced by the reinforcing plate.

[0157] Description of Reference Numerals

[0158] 10 tubes

[0159] 11 Open end

[0160] 12Inner wall surface

[0161] 20 raised weld

[0162] 15 Lower longitudinal beam (frame component for automobile)

[0163] 21 Weld Metal

[0164] 25 reinforcement plate

[0165] 26 Edge of reinforcement plate

[0166] 30 welding torch

[0167] 35 Pushing device

[0168] 40 Start

[0169] 41 End

[0170] 100, 100A, 100B reinforced tubes.

Claims

1. A method for manufacturing a reinforced tube, wherein at least one reinforcing plate made of the same material as the tube is welded inside a tube made of metal at a position intersecting with the longitudinal direction of the tube, the method for manufacturing the reinforced tube being characterized by: have: a raised bead forming step of inserting a welding torch into the interior of the tube from the open end of the tube, and forming a raised bead on at least a portion of the inner wall surface of the tube in a circumferential direction by brazing with a brazing filler metal or welding with a welding material; a reinforcing plate arranging step of inserting the reinforcing plate into the interior of the pipe after removing the welding torch from the pipe, and arranging the reinforcing plate so as to be in contact with the raised weld bead; and The reinforcing plate welding step is to fillet weld the edge of the reinforcing plate and at least a portion of the inner wall of the tube. The ridge bead forming step, the reinforcing plate arrangement step and the reinforcing plate welding step are repeatedly performed according to the number of reinforcing plates. In the reinforcing plate arranging step, the next reinforcing plate is arranged so as to be in contact with the reinforcing plate welded previously in the reinforcing plate welding step or with weld metal formed previously in the reinforcing plate welding step.

2. The method for manufacturing a reinforced tube according to claim 1, characterized in that: In the raised bead forming step, the raised bead is formed so that a tangent line of the raised bead to the reinforcing plate coincides with a planned position at which the reinforcing plate is to be arranged.

3. The method for manufacturing a reinforced tube according to claim 2, characterized in that: In the raised bead forming step, the raised bead is formed from a position away from a predetermined position for arranging the reinforcing plate in a direction opposite to the opening end of the pipe, and the welding torch is moved along the circumferential direction of the inner wall surface of the pipe while approaching the position for arranging the reinforcing plate.

4. The method for manufacturing a reinforced tube according to claim 2 or 3, characterized in that: In the raised bead forming step, after the raised bead is formed while the welding torch is moved in the circumferential direction of the inner wall surface of the pipe, the formation of the raised bead is completed at a position away from a predetermined position for arranging the reinforcing plate in a direction opposite to the opening end of the pipe.

5. A method for manufacturing a reinforced tube, wherein at least one reinforcing plate made of the same material as the tube is welded inside a tube made of metal at a position intersecting with the longitudinal direction of the tube, the method for manufacturing the reinforced tube being characterized by: have: a raised bead forming step of inserting a welding torch into the interior of the tube from the open end of the tube, and forming a raised bead on at least a portion of the circumferential direction of the inner wall surface of the tube by brazing with a brazing filler metal or welding with a welding material; a reinforcing plate arranging step of inserting the reinforcing plate into the interior of the tube after removing the welding torch from the tube, and arranging the reinforcing plate so as to be in contact with the raised bead; and The reinforcing plate welding step is to fillet weld the edge of the reinforcing plate and at least a portion of the inner wall of the tube. In the raised bead forming step, the raised bead is formed so that a tangent line of the raised bead to the reinforcing plate coincides with a predetermined position at which the reinforcing plate is to be disposed. In the raised bead forming step, the raised bead is formed from a position away from a predetermined position for arranging the reinforcing plate in a direction opposite to the opening end of the pipe, and the welding torch is moved along the circumferential direction of the inner wall surface of the pipe while approaching the position for arranging the reinforcing plate.

6. The method for manufacturing a reinforced tube according to claim 5, characterized in that: In the raised bead forming step, after the raised bead is formed while the welding torch is moved in the circumferential direction of the inner wall surface of the pipe, the formation of the raised bead is completed at a position away from a predetermined position for arranging the reinforcing plate in a direction opposite to the opening end of the pipe.

7. A method for manufacturing a reinforced tube, wherein at least one reinforcing plate made of the same material as the tube is welded inside a tube made of metal at a position intersecting with the longitudinal direction of the tube, the method for manufacturing the reinforced tube being characterized by: have: a raised bead forming step of inserting a welding torch into the interior of the tube from the open end of the tube, and forming a raised bead on at least a portion of the inner wall surface of the tube in a circumferential direction by brazing with a brazing filler metal or welding with a welding material; a reinforcing plate arranging step of inserting the reinforcing plate into the interior of the pipe after removing the welding torch from the pipe, and arranging the reinforcing plate so as to be in contact with the raised weld bead; and The reinforcing plate welding step is to fillet weld the edge of the reinforcing plate and at least a portion of the inner wall of the tube. In the raised bead forming step, the raised bead is formed so that a tangent line of the raised bead to the reinforcing plate coincides with a predetermined position at which the reinforcing plate is to be disposed. In the raised bead forming step, after the raised bead is formed while the welding torch is moved in the circumferential direction of the inner wall surface of the pipe, the formation of the raised bead is completed at a position away from a predetermined position for arranging the reinforcing plate in a direction opposite to the opening end of the pipe.

8. The method for manufacturing a reinforced tube according to any one of claims 5 to 7, characterized in that: The raised bead forming step, the reinforcing plate arranging step, and the reinforcing plate welding step are repeatedly performed according to the number of the reinforcing plates.

9. The method for manufacturing a reinforced tube according to claim 8, characterized in that: In the reinforcing plate arranging step, the next reinforcing plate is arranged so as to be in contact with the reinforcing plate welded previously in the reinforcing plate welding step or with weld metal formed previously in the reinforcing plate welding step.

10. The method for manufacturing a reinforced tube according to any one of claims 1 to 9, characterized in that: The reinforcing plate welding step is performed by inserting the welding torch used in the raised bead forming step again into the inside of the pipe from the open end of the pipe.

11. The method for manufacturing a reinforced tube according to any one of claims 1 to 10, characterized in that: The raised bead is formed so as to be inclined with respect to the longitudinal direction of the pipe.

12. The method for manufacturing a reinforced tube according to any one of claims 1 to 11, characterized in that: The edge portion of the reinforcing plate is chamfered, and a レ-shaped groove is formed between the reinforcing plate and the inner wall surface of the pipe in the reinforcing plate welding step.

13. The method for manufacturing a reinforced tube according to any one of claims 1 to 12, characterized in that: The raised bead is formed over the entire circumference of the pipe.

14. The method for manufacturing a reinforced tube according to any one of claims 1 to 13, characterized in that: The raised bead forming step, the reinforcing plate arranging step, and the reinforcing plate welding step are performed in a state where the pipe is arranged with the opening end facing vertically upward.

15. The method for manufacturing a reinforced tube according to any one of claims 1 to 14, characterized in that: The cross-sectional shape of the tube perpendicular to the longitudinal direction is a closed cross-sectional shape such as a circle, an ellipse or a polygon.

16. A reinforcing pipe, wherein at least one reinforcing plate made of the same material as the pipe is welded inside a pipe made of metal at a position intersecting with the longitudinal direction of the pipe, characterized in that: A raised weld bead is formed on the inner wall surface of the pipe at a position adjacent to the reinforcing plate on the opposite side to the side where the weld metal is formed with respect to the reinforcing plate, and at least a portion of the inner wall surface of the pipe in the circumferential direction. The raised bead has a starting end portion and a terminal portion, and at least one of the starting end portion and the terminal portion is separated from a position where the reinforcing plate is arranged in a direction opposite to an opening end side of the pipe.

17. The reinforced tube according to claim 16, characterized in that The raised bead is formed over the entire circumference of the pipe.

18. The reinforced tube according to claim 16 or 17, characterized in that: Used in automotive and construction frame parts.

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