JP2006008078A - Railway vehicle body and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a railway vehicle body and its manufacturing method capable of securing sufficient rigidity while enhancing assembling efficiency. <P>SOLUTION: In the railway vehicle body 1, a first outer plate panel 18 having a first joint piece 18b projected from a peripheral edge toward an inner surface side of the vehicle and a second outer plate panel 20 having a second joint piece 20a projected from the peripheral edge toward the inner surface side of the vehicle are joined in the state that the first and second joint pieces 18a, 20a are abutted. The abutment joint parts are welded by an inner welding part W1, an outer welding part W2 and an intermediate connection part W3. Thereby, the abutted and joined joint pieces 18b, 20a can functions by themselves as a bone member extending to the joint part of the outer plate panels 18, 20 each other and the rigidity can be sufficiently secured while making the assembling efficiency of the railway vehicle body 1 well. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a railway vehicle structure formed by joining outer panel panels and a manufacturing method thereof.

Conventionally, as a technology in such a field, for example, there is a method for manufacturing a side structure of a railway vehicle disclosed in Patent Document 1. In this method of manufacturing a railway vehicle, an intermediate window block, a side entrance block, and the like are formed by a bone member and an outer panel, and a side structure of the railway vehicle is formed by joining these blocks by welding. . In this way, the blocks constituting the side structure are individually manufactured, so that the size of each outer panel is reduced and the handling thereof is facilitated.
JP 2002-104180 A

  However, in the above-described method for manufacturing a side structure of a railway vehicle, since the bone part is joined as a separate body to the outer panel, an increase in man-hours required for assembling the side structure is inevitable. On the other hand, it is difficult to obtain sufficient rigidity as a railway vehicle structure unless a bone portion is provided on the outer panel. Therefore, there has been a demand for a technique that can satisfy the improvement of assembly workability and the guarantee of rigidity at the same time.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a railway vehicle structure that can ensure sufficient rigidity while improving assembly workability and a method for manufacturing the same.

  In order to solve the above-described problems, a railway vehicle structure according to the present invention is adjacent to a first outer plate panel having a first joining piece that protrudes from the peripheral edge toward the inner surface of the vehicle, and the first outer plate panel. And a second outer panel having a second joining piece projecting from the peripheral portion toward the vehicle inner surface side, and a joining portion where the first and second joining pieces are butted against each other Between the inner welded portion formed at the end of the butt joint portion on the inner surface of the vehicle, the outer welded portion formed at the end of the butt joint portion on the outer surface of the vehicle, and the inner welded portion and the outer welded portion. And an intermediate connecting portion formed.

  This railway vehicle structure has a first outer panel having a first joint piece projecting from the peripheral portion toward the vehicle inner surface side, and a second joint piece projecting from the peripheral portion toward the vehicle inner surface side. The 2nd outer panel is joined in the state where the 1st and 2nd joined piece was abutted. As a result, the first and second joining pieces that are abutted and joined to each other can function as they are as the bone members extending to the joining portions of the first and second outer panel panels. It is possible to sufficiently ensure the rigidity while improving the assembly workability of the. On the other hand, since the butt joint portion of the first and second joint pieces is welded by the inner welded portion and the outer welded portion, the first and second outer plate panels can be firmly joined to each other. Become. In addition, since there is no need for a stacking margin that would cause a stepped portion on the outer surface of the outer panel, no design restrictions arise. Furthermore, the 1st and 2nd joining piece is connected by the intermediate | middle connection part, and generation | occurrence | production of the space | gap in a butt-joining part is suppressed. As a result, it is possible to increase the bonding strength between the bonding pieces.

  Moreover, it is preferable that the inner side welding part is continuously formed in the longitudinal direction along the edge part at the vehicle inner surface side. Thereby, the joining of the butt joint portions in the first and second joining pieces becomes stronger, and the rigidity of the railway vehicle structure can be further increased.

  Further, it is preferable that the outer welded portion is continuously formed in the longitudinal direction along the end portion on the vehicle outer surface side. Thereby, the joint strength of the butt joint part in the first and second joint pieces can be further increased, and the rigidity of the railway vehicle structure can be further increased. Moreover, since the end portion on the vehicle outer surface side is continuously welded at the butt joint portion, the joint portion of the first and second outer panel is cut off from the outside of the vehicle. High rail vehicle structure can be created.

  Moreover, the manufacturing method of the railway vehicle structure according to the present invention includes the first joining piece protruding from the peripheral portion of the first outer plate panel toward the vehicle inner surface planned side, and the peripheral portion of the second outer plate panel. Arranged so as to abut the second joining piece projecting toward the vehicle inner surface planned side, temporarily fixing the abutting portion between the joining pieces, and after the temporary fixing step, the vehicle inner surface plan of the abutting portion An inner welding step of welding the end portion on the side, and an outer welding step of welding the end portion on the vehicle outer surface planned side of the butted portion after the temporary fixing step.

  In this method of manufacturing a railway vehicle structure, the first and second joining pieces of the first and second outer plate panels are temporarily fixed at the abutting portion, and then the end portion of the abutting portion on the vehicle inner surface side and the vehicle outer surface The end on the planned side is joined by welding. As a result, the first and second joining pieces that are abutted and joined to each other can function as they are as the bone members extending to the joining portions of the first and second outer panel panels. It is possible to sufficiently ensure the rigidity while improving the assembly workability of the. On the other hand, since the end portion on the vehicle inner surface planned side and the end portion on the vehicle outer surface planned side of the butted portion of the first and second joining pieces are joined by welding, the first and second outer plate panels are firmly strengthened. It becomes possible to join to. Moreover, according to such a manufacturing method, since the overlap allowance which a level | step-difference part arises on the surface of an outer panel is unnecessary, design restrictions do not arise. Furthermore, when manufacturing the railway vehicle structure, the inner side and the outer side of the joint portion between the first outer panel and the second outer panel are not welded suddenly, but the inner welding process and the outer welding process are performed. As a pre-process to be performed, a temporary fixing process such as welding or a fastening member is adopted, so that the alignment between the first outer panel and the second outer panel can be ensured, and firmly Inner and outer welding can be performed. In addition, since the temporary fixing step suppresses the generation of voids at the abutting portion between the first and second joining pieces, the joining strength between the joining pieces can be increased.

  Moreover, it is preferable that an outer side welding process is performed after an inner side welding process. In this case, the outer panel can be installed flat on the surface plate in the inner welding process. Thereby, while being able to suppress distortion of the outer panel on the surface plate, it is possible to improve the welding workability of the end portion on the vehicle inner surface planned side. In addition, since heat generated by welding is dissipated to the surface plate side through the planned vehicle outer surface side of the outer panel, good welding can be realized.

  Moreover, it is preferable that at least one of an inner side welding process and an outer side welding process is continuous welding of the butt | matching part. Thereby, the joining of the first and second joining pieces can be further ensured, and the rigidity of the railway vehicle structure can be further increased. Moreover, since the joint portion of the first and second outer panel can be cut off from the outside of the vehicle by continuously welding the end portion of the butted portion on the vehicle outer surface planned side, the railway is highly watertight and airtight. A vehicle structure can be created.

  As described above, according to the present invention, sufficient rigidity can be ensured while improving the assembly workability of the railway vehicle structure.

  Hereinafter, a preferred embodiment of a railway vehicle structure according to the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view showing a railway vehicle structure 1 according to the present invention. This railcar structure 1 has a floor structure 2 that constitutes a floor, a side structure 4 that constitutes a side, a roof structure 6 that constitutes a roof, and a wife structure 8 that constitutes a front part and a rear part. And each structure 2-8 is welded mutually.

  The side structure 4 includes four door units 10 and five window units 12, and a door block 14 surrounding the door unit 10 and a window block 16 surrounding the window unit 12 are welded to each other. Yes. Further, the door block 14 has waist panels 18 and 19, blowing panels 20 and 21, and a curtain panel 22. The window block 16 includes a waist panel 23, a window frame panel 24, and a curtain panel 25.

  The waist panels 18, 19, and 23 are panels that are positioned below the lower edge of the window unit 12 and are welded to the floor structure 2. The blowing panels 20 and 21 are panels positioned between the door unit 10 and the window unit 12. Further, in the door block 14, the waist panels 18 and 19 and the blowing panels 20 and 21 are arranged symmetrically with the door unit 10 interposed therebetween.

  The curtain panels 22 and 25 are panels that are positioned above the upper edge portions of the door unit 10 and the window unit 12 and are welded to the roof structure 6. The window frame panel 24 is a panel located between the waist panel 23 and the curtain panel 25 in the window block 16, and has an opening 24c (see FIG. 5) for fitting the window unit 12 into the center portion. Is formed.

  Next, the door block 14 and the window block 16 described above will be described in more detail. Each panel 18-25 which comprises the door block 14 and the window block 16 is comprised as various outer-plate panels formed, for example from stainless steel. The material of the outer panel may be aluminum alloy, high-tensile steel, or other general steel in addition to stainless steel.

  As shown in FIGS. 2 and 3, in the door block 14, long joint pieces 18 a and 19 a having an L-shaped cross section are horizontally provided at the lower edge portions of the waist panels (outer panel panels) 18 and 19. Long joint pieces 18b and 19b each having an L-shaped cross section extend in the horizontal direction at the upper edge of each. Further, long joining pieces 18c and 19c having an L-shaped cross section extend in the vertical direction at the edge of the waist panels 18 and 19 on the door unit 10 side.

  In addition, flat joint pieces 20a, 21a extend in the horizontal direction at the lower edge of each of the blowing panels (outer panel) 20, 21, and at each upper edge, The flat joining pieces 20b and 21b extend in the horizontal direction. In addition, long joining pieces 20c and 21c each having an L-shaped cross section extend in the vertical direction at the edge of the blowing panels 20 and 21 on the door unit 10 side. Further, a long joining piece 22 a having an L-shaped cross section extends in the horizontal direction at the lower edge portion of the curtain panel (outer panel) 22, and an L-shaped cross section is formed at the upper edge portion. The long joining piece 22b which has has extended in the horizontal direction.

  The waist panel 18 is welded to the blowing panel 20 in a state where the joining piece 18b formed on the upper edge portion is abutted against the joining piece 20a formed on the lower edge portion of the blowing panel 20. Further, the blowing panel 20 is welded to the curtain panel 22 in a state in which the joining piece 20b formed on the upper edge portion is abutted against the joining piece 22a formed on the lower edge portion of the curtain panel 22.

  Here, the joint piece (first joint piece) 18b of the waist panel (first outer panel) 18 and the joint piece (second joint piece) 20a of the blowing panel (second outer panel) 20 are provided. The welding will be described in detail.

  As shown in FIG. 4, the joining pieces 18 b and 20 a at the joining portion of the waist panel 18 and the blowing panel 20 are continuously welded to the end portion 26 a on the vehicle inner surface side at the abutting portion 26 between the joining piece 18 b and the joining piece 20 a. The inner welded portion W1 and the outer welded portion W2 obtained by continuously welding the end portion 26b on the vehicle outer surface side are firmly connected. Furthermore, the joining pieces 18b and 20a are welded by an intermediate connecting portion W3 at an intermediate portion 26c of the butt portion 26 between the inner welded portion W1 and the outer welded portion W2. And joining piece 18b, 20a welded by welding part W1, W2 and the connection part W3 is functioning as a bone member extended in a horizontal direction along the welding part of the waist panel 18 and the blowing panel 20 ( (See FIG. 2).

  When performing such welding, first, the waist panel 18 and the blowing panel 20 are arranged on a surface plate (not shown) so that the side surfaces 18d and 20d on the planned vehicle outer surface side are on the lower side. Next, the waist panel 18 and the blowing panel 20 are adjacent to each other so that the joining piece 20a is brought into contact with the joining piece 18b, and an intermediate portion 26c of the joining portion 26 of the joining pieces 18b and 20a is formed by spot welding. Temporarily fixed by the intermediate connecting portion W3 (temporary fixing step).

  After the temporary fixing, the end portion 26a on the vehicle inner surface planned side of the butted portion 26 is continuously welded along the longitudinal direction to form the inner welded portion W1 (inner welding step). Thereafter, the waist panel 18 and the blowing panel 20 are rearranged on the surface plate so that the side surfaces 18e, 20e on the vehicle inner surface planned side are on the lower side. And the end part 26b by the side of the vehicle outer surface planned side of the butting | matching part 26 is continuously welded along a longitudinal direction, and the outer side welding part W2 is formed (outside welding process).

  According to such a welding method, the panels 18 and 20 can be installed flat on the surface plate in the inner welding process. Thereby, distortion of each panel 18 and 20 on a surface plate can be suppressed, and it becomes possible to improve the workability | operativity of welding in the edge part 26a by the side of a vehicle inner surface plan. In addition, since heat generated by welding is smoothly radiated to the surface plate side through the side surfaces 18d and 20d on the vehicle outer surface side of the panels 18 and 20, good welding can be realized.

  As a welding method used for forming the welds W1 and W2, it is preferable to use friction stir welding (FSW), laser welding, hybrid laser welding, tandem MIG, or brazing. According to these welding methods, the amount of heat input to the panel can be reduced, so that continuous welding with suppressed heat distortion is possible. Moreover, as a method of temporary fixing by the intermediate connecting portion W3, it is preferable to use spot welding, but rivet fastening, arc welding, or fixing by bolts may be used.

  Hereinafter, as shown in FIG.2 and FIG.3, the joining piece (1st joining piece) 19b and the blowing panel (2nd outside plate) of the other waist panel (1st outside plate panel) 19 in the door block 14 are shown. Also in the welding of the panel) 21 to the joining piece (second joining piece) 21a, the joining pieces 19b and 21a are welded by the welded portions W1 and W2 and the connecting portion W3 formed according to the above-described method. The welded joint pieces 19b and 21a function as bone members extending in the horizontal direction along the welded portion between the waist panel 19 and the blowing panel 20.

  Further, also in welding of the blowing panels (first outer panel) 20, 21 and the curtain panel (second outer panel) 22, the welded portions W1, W2 and the connecting portion W3 formed according to the above-described method are used. The joining piece (first joining piece) 20b, joining piece (second joining piece) 22a, joining piece (first joining piece) 21b, and joining piece (second joining piece) 22a are welded. The welded joint pieces 20b and 22a and the joint pieces 21b and 22a function as bone members that extend in the horizontal direction along the welded portions between the blowing panels 20 and 21 and the curtain panel 22.

  Further, as shown in FIG. 2, the joining pieces 18 f projecting larger than the joining pieces 18 a to 22 a and the joining pieces 18 b to 22 b are formed on the edge portions of the panels 18 to 22 located on the end side of the door block 14. 20f, 22f and joining pieces 19g, 21g, 22g extend in the vertical direction. The joining pieces 18f, 20f, 22f and 19g, 21g, 22g are connected to each other by continuous welds W4, whereby the inter-block joints extending in the vertical direction at the front and rear ends of the door block 14. Pieces 14a and 14b are formed.

  On the other hand, as shown in FIGS. 5 and 6, in the window block 16, a long joining piece 23 a having an L-shaped cross section extends in the horizontal direction at the lower edge portion of the waist panel (outer panel) 23. In the upper edge portion, a long joining piece 23b having an L-shaped cross section extends in the horizontal direction. Further, a long joining piece 24a having an L-shaped cross section extends in the horizontal direction at the lower edge of the window frame panel (outer panel) 24, and an L-shaped cross section at the upper edge. A long joining piece 24b having a portion extends in the horizontal direction. Further, a long joining piece 25a having an L-shaped cross section extends in the horizontal direction at the lower edge of the curtain panel (outer panel) 25, and an L-shaped cross section at the upper edge. The long joining piece 25b which has has extended in the horizontal direction.

  The waist panel 23 is welded to the window frame panel 24 in a state where the joining piece 23b formed on the upper edge portion is abutted against the joining piece 24a formed on the lower edge portion of the window frame panel 24. Yes. Further, the window frame panel 24 is welded to the curtain panel 25 in a state where the joining piece 24b formed on the upper edge portion is abutted against the joining piece 25a formed on the lower edge portion of the curtain panel 25. .

  Here, in welding the waist panel 23 and the window frame panel 24, the first outer plate panel and the second outer plate panel are sequentially welded according to the above-described welding method. That is, as shown in FIG. 7, a joining piece (second joining panel) of a waist panel (first outside panel) 23 (first joining piece) 23 b and a window frame panel (second outside panel) 24 (second joining). 24a means an inner welded portion W1 obtained by continuously welding the end portion 27a on the inner surface side of the vehicle in the butt portion 27 between the joined piece 23b and the joined piece 24a, and an outer side obtained by continuously welding the end portion 27b on the outer surface side of the vehicle. It is firmly connected to the welded portion W2. Furthermore, the joining pieces 23b and 24a are welded by an intermediate connecting portion W3 at an intermediate portion 27c of the butted portion 27 between the inner welded portion W1 and the outer welded portion W2. The welded joining pieces 23b and 24a function as bone members extending in the horizontal direction along the welded portion between the waist panel 23 and the window frame panel 24 (see FIG. 5).

  Further, as shown in FIGS. 5 and 6, the same method is adopted for welding the window frame panel 24 and the curtain panel 25. That is, the joint piece (first joint piece) 24b of the window frame panel (first outer panel) 24 and the joint piece (second joint piece) 25a of the curtain panel (second outer panel) 25 are as follows. The welded portions W1 and W2 and the connecting portion W3 are welded. The welded pieces 24b and 25a function as bone members extending in the horizontal direction along the welded portion between the window frame panel 24 and the curtain panel 25.

  As shown in FIG. 5, each of the panels 23, 24, and 25 constituting the window block 16 has a shape that extends in the horizontal direction, so that the rigidity of the bone member is particularly required. For this reason, the joining pieces 24a and 24b of the window frame panel 24 have an L-shaped cross section in the upper and lower sides. That is, at the joint portion between the panels 23, 24, 25 in the window block 16, a highly rigid bone member is created by joining the joint pieces 23b, 24a and 24b, 25a having L-shaped cross sections, The window block 16 is reinforced.

  Further, as shown in FIG. 5, in each panel 23, 24, 25, a cross section that protrudes larger than the joining pieces 23 a to 25 a and the joining pieces 23 b to 25 b at the edge located on the end side of the window block 16. L-shaped joining pieces 23d, 24d, and 25d extend in the vertical direction. The joining pieces 23d, 24d, and 25d are connected to each other by a continuous welding portion W5, thereby forming an inter-block joining piece 16a that extends in the vertical direction at the front and rear ends of the window block 16. .

  As shown in FIG. 8, the door block 14 and the window block 16 are welded to each other according to the above-described welding method in a state in which the inter-block joining pieces 14a and 16a are abutted. That is, when the door block 14 and the window block 16 are welded, the inter-block joint piece (first joint piece) 14a of the door block (first outer panel) 14 and the window block (second outer panel) 16 are connected. The inter-block joint piece (second joint piece) 16a is welded by the welded portions W1 and W2 and the connecting portion W3 similar to those described above. The welded inter-block joint pieces 14 a and 16 a function as bone members extending in the vertical direction along the welded portion between the door block 14 and the window block 16.

  As described above, in this railway vehicle structure 1, the first and second joining pieces that are butted against each other are welded as they are as bone members that extend to the welded portions of the first and second outer panel panels. It is functioning. Thereby, the process of joining a bone member to an outer panel separately becomes unnecessary, and rigidity can be sufficiently secured while improving the assembly workability of the railway vehicle structure 1.

  On the other hand, since the butted portions 26 and 27 between the joining pieces are continuously welded by the inner welded portion W1 and the outer welded portion W2, it is possible to firmly join the outer plate panels. In addition, since there is no need for an overlapping margin that would cause a stepped portion on the outer surface of the outer panel, no design restrictions arise.

  Further, the welded portion of the outer panel is blocked from the outside of the vehicle by the outer welded portion W2. For this reason, a railway vehicle structure 1 with high watertightness and airtightness that can withstand sudden pressure changes and wind and rain when entering the tunnel is created.

  Furthermore, each joining piece is joined by the intermediate | middle connection part W3, and generation | occurrence | production of the space | gap is suppressed in the butt | matching parts 26 and 27. FIG. As a result, it is possible to increase the bonding strength between the bonding pieces.

  The present invention is not limited to the above embodiment. For example, various modifications can be applied to the combination of the joining pieces used for joining the outer panel, according to the design of the railway vehicle structure 1. For example, as shown in FIG. 9, a waist panel 18A having a flat joint piece 18h and a blowing panel 20A having a flat joint piece 20h that is the same length as the joint piece 18h may be combined. As shown in FIG. 10, you may combine the waist panel 18B which has the flat joint piece 18i, and the blowing panel 20B which has the flat joint piece 20i shorter than the joint piece 18i. Moreover, as shown in FIG. 11, you may combine the waist panel 18C which has the joining piece 18j of L-shaped cross section, and the blowing panel 20C which has the joining piece 20j of L-shaped cross section longer than the joining piece 18j.

  Furthermore, as shown in FIG. 12, a waist panel 18D having a flat plate-like joining piece 18k and a blowing panel 20D having a joining piece 20k having an L-shaped cross section shorter than the joining piece 18k may be combined. As shown in FIG. 5, a waist panel 18E having a flat joint piece 18l and a blowing panel 20E having a joint piece 20l having an L-shaped cross section longer than the joint piece 18l may be combined. Any combination has the same effect as the embodiment shown in FIG.

1 is a perspective view showing an embodiment of a railway vehicle structure according to the present invention. It is a perspective view of the door block seen from the vehicle inner surface side. It is the III-III sectional view taken on the line in FIG. It is a principal part expanded sectional view which shows the welding state of the joining pieces of the waist panel and blowing panel in a door block. It is a perspective view of the window block seen from the vehicle inner surface side. It is sectional drawing which follows the VI-VI line of FIG. It is a principal part expanded sectional view which shows the welding state of the joining piece of the waist panel in a window block, and the joining piece of a window frame panel. It is a perspective view which shows the connection state of a door block and a window block. It is a principal part expanded sectional view which shows another embodiment of a joining piece. It is a principal part expanded sectional view which shows another embodiment of a joining piece. It is a principal part expanded sectional view which shows another embodiment of a joining piece. It is a principal part expanded sectional view which shows another embodiment of a joining piece. It is a principal part expanded sectional view which shows another embodiment of a joining piece.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Railway vehicle structure, 18, 18A-18E, 19 ... Lumbar panel (outer panel), 20, 20A-20E, 21 ... Blowing panel (outer panel), 22, 25 ... Curtain panel (outer panel), 24 ... Window frame panels (outer panel), 18a to 25a, 18b to 25b, 18f to 18l, 20f to 20l, 22f, 19g, 21g, 22g, 23d to 25d ... Joining pieces, 26, 27 ... Butting parts (butting) Joined portion), 26a, 27a ... end on the vehicle inner surface side, 26b, 27b ... end on the vehicle outer surface side, 14a, 14b, 16a ... inter-block joint piece (joint piece), W1 ... inner welded portion, W2 ... outer side Welded part, W3 ... intermediate connecting part.

Claims (6)

A first outer panel having a first joining piece projecting from the peripheral edge toward the vehicle inner surface side;
A second outer panel adjacent to the first outer panel and having a second joining piece projecting from a peripheral edge toward the inner surface of the vehicle,
In the joint portion where the first and second joint pieces are butted against each other,
An inner weld formed at an end of the butt joint portion on the vehicle inner surface side;
An outer weld formed at an end of the butt joint portion on the vehicle outer surface side;
An intermediate connecting portion formed between the inner welded portion and the outer welded portion is provided.   The railway vehicle structure according to claim 1, wherein the inner welded portion is continuously formed in the longitudinal direction along the end portion on the vehicle inner surface side.   3. The railway vehicle structure according to claim 2, wherein the outer welded portion is continuously formed in the longitudinal direction along the end portion on the vehicle outer surface side. The 1st joining piece which protrudes toward the vehicle inner surface scheduled side from the peripheral part of a 1st outer plate panel, and the 2nd joining which protrudes toward the said vehicle inner surface planned side from the peripheral part of a 2nd outer plate panel A temporary fixing step of arranging the pieces so as to abut each other, and temporarily attaching the abutting portion between the joining pieces;
After the temporary fixing step, an inner welding step of welding the end portion of the butted portion on the vehicle inner surface planned side;
An outer welding step of welding the end portion of the butted portion on the vehicle outer surface planned side after the temporary fixing step, and a method for manufacturing a railway vehicle structure.   5. The method for manufacturing a railway vehicle structure according to claim 4, wherein the outer welding step is performed after the inner welding step.   6. The method for manufacturing a railway vehicle structure according to claim 4, wherein at least one of the inner welding step and the outer welding step, the welding of the butt portion is continuous welding.

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