Railroad vehicle underframe structure, railroad vehicle, and backing plate

Abstract

To improve productivity of an underframe in an underframe structure having a chamfered portion at a corner portion connecting an end beam and a side beam.SOLUTION: An underframe 2 of a railway vehicle 1 is provided with a chamfered portion 233 at a corner portion C that joins a side beam 22L and an end beam 21. In the underframe 2, a corner member 23 having the chamfered portion 233 is butt-welded to the end beam 21 and the side beam 22L. The underframe 2 has a backing strip 41 partially welded to the back side of welded portions P1 and P2 of the corner member 23. The backing stip 41 has a recess 411 formed at a partial welding position.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a railway vehicle underframe structure having chamfered portions at corners where side sills and end sills are joined, a railway vehicle, and a backing metal. [Background technology]

[0002] For example, on a double-track railway, if a derailed railway vehicle runs onto the oncoming track, an offset collision accident may occur in which the corners of the derailed vehicle and a vehicle traveling on the oncoming track collide, causing damage.

[0003] For example, the railway vehicle described in Patent Document 1 has diagonally chamfered portions on the corner posts that join the side structure and the end structure, and on the corner parts of the underframe to which the corner posts are joined, which allows the vehicle to deflect oncoming vehicles in the event of an offset collision, mitigating the impact load and minimizing damage to the vehicle (see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2020-100198 Summary of the Invention [Problem to be solved by the invention]

[0005] The underframe described in Patent Document 1 requires, for example, that both ends of the end beam in the vehicle width direction be cut obliquely at a predetermined angle to provide chamfered portions, which results in poor productivity of the underframe.

[0006] Therefore, an underframe structure can be considered in which corner members with chamfered portions are manufactured separately from the side sills and end sills, and then butt-welded to the side sills and end sills to assemble the corner portions of the underframe.To ensure flatness at the welded portions between the corner members and side sills, and between the corner members and end sills, backing metals made of square flat material are welded to the backside of each welded portion of the underframe.

[0007] The backing metal is partially welded to the end beams and side beams to suppress welding distortion and maintain flatness. The welding position is determined in advance, taking into consideration factors such as lifting of the backing metal due to welding. The backing metal requires marking work to clearly indicate the welding position before welding. Therefore, with conventional underframe structures, assembling the corners of the underframe is time-consuming, which can reduce underframe productivity. [Means for solving the problem]

[0008] One aspect of the technology developed to solve the above-mentioned problems is (1) a railway vehicle underframe structure having chamfered portions at corner portions joining side beams and end beams, the structure comprising: corner members having the chamfered portions formed therein and butt-welded to the side beams and end beams to form the corner portions; and backing metals that are respectively placed and partially welded on the back sides of the welded portions between the corner member and the side beams and the back sides of the welded portions between the corner member and the end beams, the backing metals being formed from flat plates and having recesses at each partial weld position.

[0009] In the underframe structure for railway vehicles having the above configuration, the partial welding positions of the backing metal are clearly indicated by the recesses formed in the backing metal, so there is no need to perform marking work to clearly indicate the partial welding positions before welding the backing metal. Therefore, the underframe structure for railway vehicles having the above configuration simplifies the assembly work of the corner portions and can improve the productivity of the underframe.

[0010] (2) In the railway vehicle underframe structure described in (1), it is preferable that the backing metal is welded to a portion of the inner edge of the recess that is away from the opening.

[0011] In the railway vehicle underframe structure having the above configuration, a portion of the inner edge of the recess away from the opening is welded, so that a weld bead that occurs during partial welding of the backing metal is less likely to form outside the recess. Thus, with the railway vehicle underframe structure having the above configuration, weld beads that interfere with subsequent processes are less likely to occur during welding of the backing metal, and the effort required to remove the weld beads is reduced.

[0012] (3) In the railway vehicle underframe structure described in (1) or (2), it is preferable that the recess is formed in a rectangular shape, and the backing metal is welded to the bottom of the recess.

[0013] In the railway vehicle underframe structure having the above configuration, the backing metal is line-welded along the bottom of the rectangular recess, making it easy to manage the weld length so as to suppress distortion due to welding. Since the weld bead generated during partial welding of the backing metal is unlikely to form outside the recess, the effort required to remove the weld bead, which can interfere with subsequent processes, is reduced.

[0014] (4) In the underframe structure for a railway vehicle described in any one of (1) to (3), it is preferable to have a jack support plate fixed to the underside of the corner portion, and an L-shaped reinforcing member arranged above the jack support plate and connected to the end beam and the side beam at a position outside the recess of the backing metal.

[0015] The railway vehicle underframe structure having the above configuration allows the reinforcing member to be attached while avoiding the welded portion of the backing metal, reducing the effort required to remove the weld beads that are generated when the backing metal is welded.

[0016] Another aspect of the technology disclosed in this specification is (5) a railway vehicle comprising an underframe, side structures connected to both ends of the underframe in the vehicle width direction, end structures connected to both ends of the underframe in the vehicle length direction, and a roof structure connected to upper ends of the side structures and the end structures, wherein the underframe has side beams, end beams, corner members each having a chamfered portion and being butt-welded to the side beams and the end beams to form a corner portion of the underframe, and backing metals that are respectively arranged and partially welded to the back side of the welded portion between the corner member and the side beams and the back side of the welded portion between the corner member and the end beam, and the backing metals are formed from a flat plate and have a recess provided at each partial weld position.

[0017] Furthermore, another aspect of the technology disclosed in this specification is (6) a backing metal used in a railway vehicle underframe in which side beams and end beams are butt-welded to corner members, and which is placed and partially welded on the back side of the welded portion between the side beams and the corner members and the back side of the welded portion between the corner members and the end beams, and which is formed from a flat plate and has a recess at each partial welding position.

[0018] The railway vehicle and backing member having the above configuration can also realize the functions of the above underframe structure, and are novel and useful. [Effects of the Invention]

[0019] According to the technology disclosed in this specification, a technology can be realized that simplifies the assembly work of the corner portions and improves the productivity of the underframe in a frame structure that has corner portions that connect end beams and side beams. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a schematic perspective view of a body structure of a railway vehicle according to an embodiment of the present invention. [Figure 2] FIG. [Figure 3] 3 is a cross-sectional view taken along the line AA in FIG. 2. [Figure 4] FIG. 3 is an exploded perspective view of part B in FIG. 2. [Figure 5] 10A to 10C are diagrams illustrating the underframe assembly procedure. [Figure 6] 10A to 10C are diagrams illustrating the underframe assembly procedure. [Figure 7] 7 is an enlarged view of a backing metal welded portion shown in part D in FIG. 6. [Figure 8] 10A to 10C are diagrams illustrating the underframe assembly procedure. [Figure 9] FIG. 9 is a view of FIG. 8 as seen from the back. [Figure 10] 10A to 10C are diagrams illustrating the underframe assembly procedure. [Figure 11] 10A to 10C are diagrams illustrating the underframe assembly procedure. DETAILED DESCRIPTION OF THE INVENTION

[0021] The present specification discloses a railway vehicle using an underframe having corner portions that connect end sills and side sills.

[0022] (General configuration of railway vehicles) The schematic configuration of a railway vehicle 1 of this embodiment will be described with reference to Figures 1 to 4. X, Y, and Z shown in each drawing indicate the orientation of the railway vehicle 1. X indicates the vehicle length direction, Y indicates the vehicle width direction, and Z indicates the up-down direction. Front indicates the front side in the direction of vehicle travel, and rear indicates the rear side in the direction of vehicle travel. Left indicates the left side of the railway vehicle 1 when viewed from the rear of the vehicle, and right indicates the right side of the railway vehicle 1 when viewed from the rear of the vehicle. Up indicates the overhead side, and down indicates the ground side.

[0023] As shown in FIG. 1, a railway vehicle 1 has a carbody 6 configured to form a hexahedron by an underframe 2, side structures 3, end structures 4, and a roof structure 5. The underframe 2 is rectangular, and has floor panels (not shown) attached to it. The underframe 2 has the lower ends of the side structures 3 connected to both left and right ends, and the lower ends of the end structures 4 connected to both front and rear ends. The end structure 4 has corner posts 7 erected at both left and right ends, and is connected to the front ends of the side structures 3 via these corner posts 7. The roof structure 5 is connected to the upper ends of the side structures 3 and end structures 4.

[0024] The carbody 6 has carbody chamfered portions CH provided at each of the four corner portions C along the vertical direction Z. The carbody chamfered portions CH are formed by inclined surfaces that are inclined at an acute angle relative to the end body structure 4 and the side body structure 3. The carbody chamfered portions CH are composed of chamfered portions 71 provided on the corner posts 7 and chamfered portions 233 provided on the underframe 2.

[0025] (Outline of the underframe) As shown in Fig. 2, the underframe 2 includes a pair of side sills 22L, 22R extending in the vehicle length direction X, and an end sill 21 extending in the vehicle width direction Y. The underframe 2 has corner portions C formed by connecting the left and right end portions of the end sill 21 to the front ends of the side sills 22L, 22R via corner members 23, respectively. Although not shown, the corner portion provided at the rear end of the underframe is also configured in the same way. Since each corner portion C of the underframe 2 is configured in the same way, the left front corner portion C shown in part B of Fig. 2 will be described below as an example.

[0026] As shown in FIGS. 2 and 3, at the corner portion C of the underframe 2, the end beam 21 and the side beam 22L are butt-welded to the corner member 23.

[0027] As shown in Fig. 3, backing metals 41 are welded to the back side of welded portion P1 between the end beam 21 and the corner member 23, and to the back side of welded portion P2 between the side beam 22L and the corner member 23. The underframe 2 has a lower plate 32 attached along the lower surface of the end beam 21, and a jack receiving plate 33 attached to the lower surface of the corner portion C. In order to increase the rigidity of the underframe 2 when it is lifted via the jack receiving plate 33, L-shaped reinforcing members 42 are arranged in the corner portion C.

[0028] In this embodiment, the end beam 21, side beams 22L, 22R, corner members 23, backing metal 41, reinforcing member 42, lower plate 32, and jack support plate 33 are made of metal such as stainless steel or carbon steel.

[0029] The components that make up corner portion C will be described in detail with reference to Figure 4. End beam 21 has floor support portion 212 and lower plate mounting portion 213 that are bent rearward along the upper and lower edges of end surface portion 211 that extends in vehicle width direction Y. Lower plate mounting portion 213 has a smaller width in vehicle length direction X than floor support portion 212, since backing metal 41 is welded to it.

[0030] The side beam 22L has a side surface portion 221 extending in the vehicle length direction X. An upper surface portion 222T and a lower surface portion 222B are connected to the upper and lower ends of the side surface portion 221 via bent portions 224T, 224B. The upper surface portion 222T and the lower surface portion 222B are arranged horizontally. The upper surface portion 222T has an upper mounting portion 223T extending forward from the side surface portion 221. The lower surface portion 222B has a lower mounting portion 223B, similar to the upper surface portion 222T.

[0031] The corner member 23 includes a first joint portion 231, a second joint portion 232, and a chamfered portion 233. The first joint portion 231 extends in the vehicle width direction Y and is butt-welded to the end sill 21. The second joint portion 232 extends in the vehicle length direction X and is butt-welded to the side sill 22L. The first joint portion 231 and the second joint portion 232 are arranged in perpendicular directions. The chamfered portion 233 is interposed between the first joint portion 231 and the second joint portion 232 and is formed by an inclined surface that is inclined at an acute angle with respect to the first joint portion 231 and the second joint portion 232. The corner member 23 and the corner post 7 of this embodiment are formed by cutting an extrusion-molded product and have the same shape except for their height in the up-down direction Z.

[0032] The upper mounting portion 223T and the lower mounting portion 223B are each formed in a right-angled pentagon (a shape obtained by cutting each portion of a rectangle diagonally) so as to support the corner member 23 from the back side. For example, the upper mounting portion 223T extends from the left end of the upper surface portion 222T to an imaginary plane formed by extending the side surface portion 221 forward. The upper mounting portion 223T includes a first abutting portion 223a, a second abutting portion 223b, and a third abutting portion 223c. The first abutting portion 223a is butt-welded to the first joint portion 231 of the corner member 23. The second abutting portion 223b is butt-welded to the second joint portion 232 of the corner member 23. The third abutting portion 223c is butt-welded to the chamfered portion 233 of the corner member 23. The second contact portion 223b is located on an imaginary plane formed by extending forward the side surface portion 221. The lower attachment portion 223B is configured in the same manner as the upper attachment portion 223T.

[0033] The backing metal 41 is made of a rectangular flat plate, and is partially welded to the inner surface 211a of the end face portion 211 that constitutes the end beam 21 and the inner surface 221a of the side surface portion 221 that constitutes the side beam 22L. The partial welding positions of the backing metal 41 are determined in advance to suppress welding distortion, and a recess 411 is provided at each partial welding position. The backing metal 41 of this embodiment has two rectangular recesses 411 cut out at a long side end 412, which is one of the ends of the four sides. The backing metal 41 is formed, for example, by cutting it out from a plate material using laser processing.

[0034] The lower plate 32 has a rectangular shape. The lower plate 32 is disposed from the lower surface 222B of the side beam 22L to the lower surface 222B of the side beam 22R. The width of the lower plate 32 in the vehicle length direction X is larger than the lower plate mounting portion 213 of the end beam 21, and the lower plate 32 is disposed parallel to the floor support portion 212 of the end beam 21. Furthermore, the lower plate 32 is provided with a protruding portion 32a (approximately rectangular in this embodiment) that protrudes from the left end portion, and the protruding portion 32a is overlapped and joined from the underside of the lower mounting portion 223B of the side beam 22L.

[0035] The jack support plate 33 has a rectangular shape. The jack support plate 33 is joined to the lower plate 32 and its protruding portion 32a by welding or the like. The reinforcing member 42 has an L-shaped cross section, formed by bending a rectangular plate at a substantially right angle in the center. The reinforcing member 42 is disposed above the jack support plate 33 with the bent portion protruding on the side opposite the corner member 23. The reinforcing member 42 is welded to the end beam 21, the side beam 22L, and the lower plate 32, thereby increasing the rigidity of the mounting portion of the jack support plate 33.

[0036] (Frame assembly procedure) The procedure for assembling the underframe 2 will be described. As shown in Fig. 5, the end beam 21 has the side beam 22L joined to its left end. That is, for example, as shown in W11 in Fig. 5, the left edge of the floor support portion 212 of the end beam 21 is butt-welded to the right edges of the upper surface portion 222T and the upper mounting portion 223T that constitute the side beam 22L. As shown in W12 in Fig. 5, the left edge of the lower plate mounting portion 213 of the end beam 21 is butt-welded to the right edge of the lower mounting portion 223B that constitutes the side beam 22L.

[0037] 6, backing metals 41 are welded to the end beam 21 and the side beams 22L, respectively. Specifically, the backing metal 41 is partially welded to the inner surface 211a at the left end of the end face portion 211 constituting the end beam 21, and to the inner surface 221a at the front end of the side surface portion 221 constituting the side beam 22L, respectively.

[0038] 7, the backing metal 41 has recesses 411 formed at each partial welding position. In this embodiment, the backing metal 41 has a long side end 412 with a length L1 of 100 mm, an opening width L2 of 30 mm of the recesses 411, and a spacing L3 of 30 mm between the recesses 411. The recesses 411 serve as markers for identifying the partial welding positions of the backing metal 41, without the need for marking work to clearly indicate the welding positions before welding.

[0039] 7, the backing metal 41 protrudes leftward from the left end of the end surface portion 211, and the bottoms 411a of the recesses 411 are line-welded to the inner surface 211a of the end surface portion 211 with the recesses 411 positioned on the inner surface 211a of the end surface portion 211. Because the weld length of the backing metal 41 is determined by the bottoms 411a of the recesses 411, distortion due to welding heat is suppressed and a flat state can be ensured even after welding.

[0040] A weld bead is formed at the welded portion of backing metal 41. Because backing metal 41 is line-welded at bottom 411a of recess 411, the weld bead is contained within recess 411 and is not formed outside long side end 412. Therefore, the weld bead of backing metal 41 does not interfere with subsequent processes such as welding of reinforcing member 42, and there is no need to remove the weld bead.

[0041] As shown at W31 and W32 in Fig. 8, the corner member 23 is butt-welded to the end beam 21 and the side beam 22L. For example, as shown at W31 in Fig. 8, when the welded portion P1 between the end beam 21 and the corner member 23 is welded from the front side, the backing metal 41 arranged on the back side of the welded portion P1 melts into the gap between the end beam 21 and the corner member 23 due to the welding heat, firmly joining the end beam 21 and the corner member 23. The same applies to the backing metal 41 arranged on the back side of the welded portion P2 between the side beam 22L and the corner member 23.

[0042] The backing metal 41 ensures flatness during partial welding. The corner member 23 is positioned flush with the end face portion 211 of the end sill 21 and the side surface portion 221 of the side sill 22L by abutting against the backing metal 41. Therefore, the underframe 2 can be butt-welded to the end sill 21 and the side sill 22L with the corner member 23 positioned flush with the end sill 21 and the side sill 22L, and a corner portion C with a good appearance can be formed.

[0043] 9, corner member 23 welded to end beam 21 and side beam 22L has inner surfaces 231a, 232a, 233a of first joint portion 231, second joint portion 232, and chamfered portion 233 abutting against first abutment portion 223a, second abutment portion 223b, and third abutment portion 223c (see FIG. 6) of upper mounting portion 223T and lower mounting portion 223B that constitute side beam 22L. Corner member 23 is supported and reinforced from the back side by upper mounting portion 223T and lower mounting portion 223B.

[0044] 10, the lower plate 32 is disposed in the vehicle width direction Y along the end sill 21 and is welded to the lower plate mounting portion 213 of the end sill 21 and to the lower surface portion 222B and lower mounting portion 223B of the side sill 22L. The jack support plate 33 is welded to the left front corner and the protruding portion 32a of the lower plate 32. The welding method may be, for example, fillet welding along the joint surface or partial welding such as spot welding.

[0045] 11, the reinforcing member 42 is inserted between the floor support portion 212 and the lower plate mounting portion 213 with the bent portion protruding to the opposite side from the corner member 23, and abuts against the inner surface 211a of the end face portion 211 at a position to the right of the long side end portion 412 of the backing metal 41 welded to the end beam 21, and abuts against the inner surface 221a of the side face portion 221 at a position rearward of the long side end portion 412 of the backing metal 41 welded to the side beam 22L. As indicated by W41, W42, and W43 in FIG. 11, the reinforcing member 42 has butt portions welded to the inner surface 211a of the end face portion 211, the inner surface 221a of the side face portion 221, and the upper mounting portion 223T and the lower mounting portion 223B of the side beam 22L.

[0046] At this time, the weld bead of the backing metal 41 is not formed outside the recess 411. Therefore, the reinforcing member 42 can be joined to the end sill 21 and the side sill 22L without the need to remove the weld bead of the backing metal 41. This completes the assembly of the corner portion C of the underframe 2.

[0047] (Body assembly) The carbody 6 has end bodies 4, each having corner posts 7 fixed to its end in the vehicle width direction Y, connected to the front and rear ends of the underframe 2. The side bodies 3, for example, have their front ends connected to the end bodies 4 via the corner posts 7, and their lower ends connected to the underframe 2. The roof bodywork 5 is connected to the upper ends of the end bodies 4 and side bodies 3 connected to the underframe 2.

[0048] In this embodiment, the corner member 23 and the corner post 7 are formed by cutting a single extrusion molded product. Therefore, in the car body 6, the positions of the chamfered portion 71 of the corner post 7 and the chamfered portion 233 of the underframe 2 are aligned, and an attractive car body chamfered portion CH can be formed.

[0049] (Vehicle body destruction due to offset collision) For example, the railway vehicle 1 may derail while traveling on a double track, causing a corner of the carbody 6 to collide with an oncoming vehicle traveling on the opposite track. The carbody 6 can absorb the collision load during an offset collision by using the carbody chamfered portion CH, thereby suppressing deformation.

[0050] Even though the corner members 23 of the underframe 2 are separate members from the end beams 21 and the side beams 22L, the corner members 23 are firmly joined to the end beams 21 and the side beams 22L via the backing metals 41. Therefore, even if a collision load during an offset collision acts on the corner members 23, the underframe 2 is unlikely to break at the welded portions P1 between the end beams 21 and the corner members 23 or at the welded portions P2 between the corner members 23 and the side beams 22L.

[0051] The corner member 23 is supported from the back side by, for example, the upper mounting portion 223T and the lower mounting portion 223B of the side beam 22L. Therefore, even if a collision load acts on the corner member 23 during an offset collision, deformation of the corner member 23 is suppressed. Therefore, the corner portion C of the underframe 2 is less likely to deform during an offset collision.

[0052] 3, the underframe 2 has a space S between the corner member 23 and the reinforcing member 42. The space S allows the underframe 2 to absorb a collision load during an offset collision, and deformation of the corner portion C is suppressed.

[0053] In the railway vehicle 1, deformation of the corner portion C of the underframe 2 is suppressed during an offset collision, thereby suppressing fracture of the joint portion between the underframe 2 and the side structure 3 and the joint portion between the underframe 2 and the end structure 4. Therefore, the railway vehicle 1 can reduce compression of the interior space during an offset collision.

[0054] As described above, in the underframe structure for a railway vehicle of this embodiment, the partial welding positions of the backing metal 41 are clearly indicated by the recesses 411 formed in the backing metal 41, so there is no need to perform marking work to clearly indicate the partial welding positions before welding the backing metal 41. Therefore, according to the underframe structure for a railway vehicle of this embodiment, the assembly work of the corner portions C can be simplified and the productivity of the underframe 2 can be improved.

[0055] The embodiments disclosed herein are merely examples and do not limit the present invention in any way. Therefore, the technology disclosed herein can naturally be improved and modified in various ways without departing from the spirit and scope of the invention. For example, the corner member 23 may be joined to the end beam 21 and the side beam 22L by a method other than butt welding. For example, the shapes of the end beam 21, the side beams 22L and 22R, and the corner member 23 may differ from those of the above-described embodiment.

[0056] For example, the backing metal 41 may be partially welded along the entire inner edge of the recess 411. However, if the backing metal 41 is welded to a portion of the inner edge of the recess 411 that is distant from the opening, the weld bead that occurs during partial welding of the backing metal 41 is less likely to be formed outside the recess 411 (long side end 412). This makes it less likely that weld beads that interfere with subsequent processes will be generated when welding the backing metal 41, and reduces the effort required to remove the weld beads.

[0057] For example, the backing metal 41 may have a shape other than rectangular. The shape and number of the recesses 411 may differ from those in the above embodiment. For example, the recesses 411 may be formed in a shape other than rectangular, such as a semicircular shape. Also, for example, the backing metal 41 may be partially welded in a U-shape along the inner edge of the rectangular recess 411. However, by line-welding the backing metal 41 along the bottom 411a of the rectangular recess 411, it becomes easier to manage the weld length so as to suppress distortion due to welding. Since weld beads generated during partial welding of the backing metal 41 are unlikely to form outside the recess 411, the effort required to remove weld beads that interfere with subsequent processes is reduced.

[0058] For example, at least one or both of the lower plate 32 and the jack support plate 33 may be omitted. However, by attaching the lower plate 32 to the underside of the end beam 21, the rigidity of the front end portion of the underframe 2 can be increased. By attaching the jack support plate 33 to the underside of the corner portion C, the rigidity of the underframe 2 can be increased against a load acting on the corner portion C, for example, when a jack-up device is inserted into the corner portion C to lift the railway vehicle 1.

[0059] For example, the reinforcing member 42 may be omitted. However, by connecting the reinforcing member 42 to the end beam 21 and the side beam 22L above the jack receiving plate 33 and reinforcing the mounting portion of the jack receiving plate 33, it is possible to suppress deformation of the corner portion C when, for example, a jack-up device is inserted into the corner portion C to jack up the railway vehicle 1. Furthermore, by increasing the rigidity of the corner portion C with the reinforcing member 42, it is possible to suppress deformation of the corner portion C of the underframe 2 due to a collision load during an offset collision, etc.

[0060] The reinforcing member 42 may have a shape other than an L-shape, such as a rectangular pillar or other columnar shape. Multiple L-shaped reinforcing members 42 may be stacked or spaced apart at a predetermined interval and placed on the back side of the corner member 23. In this case, the bent portion of the reinforcing member 42 may be placed toward the corner member 23. However, if the reinforcing member 42 is L-shaped, placed above the jack support plate 33, and joined to the end beam 21 and the side beam 22L at a position outside the recess 411 of the backing metal 41, the reinforcing member 42 can be attached while avoiding the welded portion of the backing metal 41, reducing the effort required to remove the weld bead generated when welding the backing metal 41.

[0061] For example, the corner members 23 may be manufactured separately from the corner posts 7. The assembly procedure for the underframe 2 and the car body 6 may be different from that in the above embodiment. [Explanation of symbols]

[0062] 1. Railway vehicles 2 frame 3 Side structure 4 Wife structure 5 Roof structure 21 End beam 22L side beam 23 Corner member 33 Jack support plate 41 Backstop 411 recess 411a bottom 42 Reinforcement member 233 Chamfered part C corner part P1, P2 welded parts

Claims

1. In a railway vehicle underframe structure having chamfered portions at corners connecting side beams and end beams, a corner member that is formed with the chamfered portion and that is butt-welded to the side beam and the end beam to form the corner portion; backing metals that are respectively arranged and partially welded on the back side of the welded portion between the corner member and the side beam and the back side of the welded portion between the corner member and the end beam; and The backing metal is formed of a flat plate, and a recess is provided at each partial welding position. The underframe structure for a railway vehicle is configured as follows.

2. 2. The railway vehicle underframe structure according to claim 1, The backing metal is welded to a portion of the inner edge of the recess away from the opening. The underframe structure for a railway vehicle is configured as follows.

3. 2. The railway vehicle underframe structure according to claim 1, The recess is formed in a rectangular shape, The backing metal is welded to the bottom of the recess. The underframe structure for a railway vehicle is configured as follows.

4. 2. The railway vehicle underframe structure according to claim 1, a jack support plate fixed to the underside of the corner portion; an L-shaped reinforcing member disposed above the jack support plate and connected to the end beam and the side beam at a position outside the recess of the backing metal; having The underframe structure for a railway vehicle is configured as follows.

5. A railway vehicle comprising an underframe, side structures connected to both ends of the underframe in a vehicle width direction, end structures connected to both ends of the underframe in a vehicle length direction, and a roof structure connected to upper ends of the side structures and the end structures, The underframe is Side beams and Edge beam and corner members each having a chamfered portion and butt-welded to the side beam and the end beam to form a corner portion of the underframe; backing metals that are respectively arranged and partially welded on the back side of the welded portion between the corner member and the side beam and the back side of the welded portion between the corner member and the end beam; and The backing metal is formed of a flat plate, and a recess is provided at each partial welding position. A railway vehicle configured as follows:

6. A backing metal used in a railway vehicle underframe in which an end beam is butt-welded to the first joint and a side beam is butt-welded to the second joint for a corner member having a first joint and a second joint extending in directions perpendicular to each other when viewed from above, and a chamfered portion interposed between the first joint and the second joint so as to be inclined relative to the first joint and the second joint, and which is placed on the back side of the welded portion between the side beam and the second joint, or on the back side of the welded portion between the first joint and the end beam and partially welded, The welding groove is formed of a flat plate and has a recess at each partial welding position. A backing fund that is structured as follows:

Images