Manufacturing method of rail vehicle body

Abstract

To provide a manufacturing method of a railway vehicle body structure which has a body structure with a large transmission loss capable of effectively suppressing intrusion of transmissive sound into a vehicle interior, while having high reliability and light weight.SOLUTION: In a manufacturing method of a railway vehicle body structure having an underframe forming a floor surface, side body structures erected at both end parts in a width direction of the underframe, and an upper floor panel constituting the underframe, the railway vehicle body structure has a ferrous face plate formed by a ferrous material and an aluminum bone member arranged on a vehicle interior side of the ferrous face plate and formed of an aluminum material, brings the ferrous face plate and the aluminum bone member into close contact, allows a tool of friction agitation to abut from a portion side of the closely contacted aluminum bone member, moves the tool so as to overlap a bonding line while being rotated around an axis of the tool, and performs friction stir welding on the ferrous face plate and the aluminum bone member.SELECTED DRAWING: Figure 10

Description

[Technical field]

[0001] The present invention relates to a method for manufacturing a rail car structure. [Background technology]

[0002] A railway vehicle has a hexahedral railway vehicle structure consisting of an underframe forming the floor surface, side structures erected at both ends of the underframe in the width direction, end structures erected at both ends of the underframe in the longitudinal direction, and a roof structure placed on the upper ends of the side structures and the end structures. In general, iron-based stainless steel plates have excellent weather resistance and corrosion resistance, but have the disadvantage of being relatively heavy in specific gravity. Therefore, in order to compensate for the disadvantages of stainless steel plates, railway vehicle structures have been developed that combine stainless steel outer plates with main parts made of aluminum alloys, which have a relatively low specific gravity, to provide strength.

[0003] Patent Document 1 discloses a method for manufacturing a railway car body structure by friction stir welding a stainless steel plate to an aluminum alloy extruded shape material. According to this technology, an aluminum alloy extruded hollow shape material is friction stir welded from the inside of the car, and a stainless steel plate is friction stir welded from the inside of the car to the butt joint of the hollow shape material on the outside of the side structure, thereby forming the side structure of the car body. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2008-55498 A Summary of the Invention [Problem to be solved by the invention]

[0005] In general, the thickness of the components constituting the rail car body structure used in high-speed railway cars and the like is reduced in order to reduce the weight. However, as a result of the emphasis on weight reduction, noise from outside the car is more likely to penetrate the roof body structure, side body structure, and underframe that constitute the hexahedral body structure of the rail car and enter the car interior, and this noise is perceived as transmitted sound, which may cause discomfort to passengers.

[0006] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a manufacturing method for a railway vehicle body structure that is highly reliable, lightweight, and has a large sound transmission loss that can effectively suppress the intrusion of transmitted sound into the vehicle interior. [Means for solving the problem]

[0007] In order to solve the above problems, one representative method for manufacturing a railway car body structure according to the present invention is as follows: A frame forming the floor surface; Side structures erected at both ends in a width direction of the frame; An upper floor panel that constitutes the underframe; A method for manufacturing a railway vehicle structure having The side structure includes: a ferrous face plate formed from a ferrous material; an aluminum-based frame member that is placed on the vehicle interior side of the iron-based panel and is made of an aluminum-based material; It has The aluminum-based frame member has a top hat-shaped cross section intersecting a longitudinal direction of the aluminum-based frame member and has a pair of edges, The iron-based face plate and the edge portion are brought into close contact with each other, A friction stir welding tool is brought into contact with the aluminum-based frame member from the side of the portion of the aluminum-based frame member that is in close contact with the aluminum-based frame member, and the tool is rotated around its axis while moving the tool so as to overlap the weld lines, thereby friction stir welding the iron-based face plate and the aluminum-based frame member. While rotating the tool around a counterclockwise axis, the tool is advanced along a first direction to form a first weld line by friction stir welding the edge portion to the ferrous face plate; While rotating the tool counterclockwise, the tool is advanced along a second direction opposite to the first direction, with the first weld line being seen to the left of the direction of advancement of the tool, to form a second weld line by friction stir welding the edge portion to the iron-based face plate; The hook defect caused by the friction stir welding to form the first weld line is a hook defect caused by the friction stir welding to form the second weld line. Defects and This is achieved by overlapping a part of the first joining line and a part of the second joining line in the width direction of the aluminum-based frame member. Effect of the Invention

[0008] According to the present invention, it is possible to provide a manufacturing method for a railway vehicle body structure that is highly reliable, lightweight, and has a body structure with a large transmission loss that can effectively suppress the intrusion of transmitted sound into the vehicle interior. Problems, configurations and effects other than those described above will become apparent from the following description of the embodiments. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a side view of a railway vehicle. [Diagram 2] FIG. 2 is a cross-sectional view (cross-section AA in FIG. 1) intersecting the longitudinal direction of the railway vehicle. [Diagram 3] FIG. 3 is a cross-sectional view (part B in FIG. 2) intersecting the longitudinal direction of the side structure of the railway vehicle. [Figure 4] FIG. 4 is a cross-sectional view (cross-section DD in FIG. 3) intersecting in the height direction of the side structure of the railway vehicle. [Diagram 5] FIG. 5 is a schematic diagram (view taken along the arrow C in FIG. 3) showing a process for manufacturing a side structure of a railway car. [Figure 6] FIG. 6 is a cross-sectional view of one edge of the frame member immediately after it has been joined at one joining line, in the process of joining the frame member to an exterior panel of a vehicle. [Figure 7] FIG. 7 is a cross-sectional view of the other edge of the frame member immediately after the edge has been joined at two joining lines in the process of joining the frame member to the vehicle exterior panel. [Figure 8] FIG. 8 is a schematic top view showing the configuration of the upper floor panel. [Figure 9] FIG. 9 is a cross-sectional view of the upper floor panel (cross-section GG in FIG. 8). [Figure 10] FIG. 10 is a flow chart showing the process of joining the side structure and the upper floor panel. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. First, the directions used in the description will be defined. The longitudinal direction of the rail vehicle or the rail direction is the x-direction, the width direction of the rail vehicle or the sleeper direction is the y-direction, and the height direction of the rail vehicle is the z-direction, and hereinafter, these will be simply referred to as the x-direction, y-direction, and z-direction.

[0011] Rail vehicles are vehicles that run along a laid track, and include railway cars, monorail cars, trams, new transit cars, etc. As a representative example of rail vehicles, an embodiment of the present invention will be described using a railway car. In this specification, "iron-based material" refers to a material that contains at least Fe, and preferably further contains C. In addition, "aluminum-based material" refers to a material that contains at least Al.

[0012] Fig. 1 is a side view of a railway vehicle, and Fig. 2 is a cross-sectional view (cross-section AA in Fig. 1) intersecting the longitudinal direction of the railway vehicle. The railway vehicle 1 has a hexahedral body structure 3, and both ends of the body structure 3 in the x direction are supported by bogies 2 having wheels that roll on tracks (rails) 90.

[0013] The structure 3 is a hexahedron made up of an underframe 7 forming the floor surface, side structures 6 erected at both ends in the y direction of the underframe 7, end structures 9 erected at both ends in the x direction of the underframe 7, and a roof structure 5 placed on the upper ends (ends in the z direction) of the side structures 6 and the end structure 9. A partition wall 69 is provided substantially parallel to the end structure 9, separating a deck section having an entrance where passengers etc. get on and off from a passenger compartment section where seats are located, and the partition wall 69 is provided with a partition door 76 for use in the movement of passengers etc.

[0014] The structure 3 connects a pair of side structures 6 extending along the y direction at a height position approximately equal to the height of the platform 92, and has a plurality of cross beams 12 provided discretely along the x direction. An upper floor panel 72 is provided above the cross beams 12 via support members (not shown), and seats 70 and the like are placed on the upper surface of the upper floor panel 72. Various electrical equipment such as the bogie 2, transformer, main circuit equipment, auxiliary power supply unit, and air compressor are provided below the cross beams 12 which support the upper floor panel 72 and constitute the underframe 7.

[0015] Fig. 3 is a cross-sectional view (part B in Fig. 2) intersecting in the longitudinal direction of the side structure of the railway car, and Fig. 4 is a cross-sectional view (section DD in Fig. 3) intersecting in the height direction of the side structure of the railway car. Since roof structure 5 and side structure 6 basically have the same configuration, the configuration of side structure 6 will be explained as a representative example with reference to Figs. 3 to 7, and an explanation of roof structure 5 will be omitted.

[0016] The side structure 6 is composed of a vehicle exterior panel 6a and a frame member (pillar) 6b that supports the vehicle exterior panel 6a from the vehicle interior side. The frame member 6b is a member with a top hat-shaped cross section intersecting the z direction, that is, a pair of plate-shaped edge portions 6bh extend oppositely from both side edges of a main body with a U-shaped cross section. The pair of edge portions 6bh that constitute the frame member 6b are placed in contact with the vehicle exterior panel 6a and then connected to the vehicle interior surface of the vehicle exterior panel 6a by friction stir welding using a method described below.

[0017] Fig. 5 is a schematic diagram (view taken along the C arrow in Fig. 3) showing the process of manufacturing the side structure of a railway car. The schematic diagram showing the manufacturing process of the side structure 6 shown in Fig. 5 shows the process of positioning the rib member 6b on the inner surface (upper surface) of the car exterior panel 6a placed on a surface plate, and then connecting the rib member 6b to the car exterior panel 6a by friction stir welding.

[0018] Although not shown, the tool T used for friction stir welding has a coaxial two-stage cylindrical shape with a cylindrical small diameter part at the tip of the large diameter part and on the same axis as the axis of the large diameter part. The small diameter part of the tool T is embedded in the edge part 6bh of the bone member 6b while rotating around its axis, and the bone member 6b is joined to the vehicle exterior panel 6a in the process of moving along the longitudinal direction of the edge part 6bh at a predetermined feed speed (joining speed) in a state in which the end face of the large diameter part of the tool T is located on the upper surface of the edge part 6bh. Along the trajectory of the movement of the tool T, a joining line L1 (L2) is generated as described below.

[0019] <Production method> Fig. 6 is a cross-sectional view of the edge of the bone member immediately after one edge of the bone member is joined with one joining line during the process of joining the bone member to the vehicle exterior panel. Fig. 7 is a cross-sectional view of the edge of the bone member immediately after the other edge of the bone member is joined with two joining lines during the process of joining the bone member to the vehicle exterior panel. One edge 6bh shown in Fig. 6 is also joined with two joining lines, like the other edge 6bh, but in order to explain the problems in joining and the process of solving the problems, a cross-sectional view immediately after joining with only one joining line L1 is shown as a comparative example.

[0020] 6 is a schematic diagram showing a process of joining one edge 6bh to the vehicle exterior panel 6a while advancing a tool T rotating in a counterclockwise direction 32 in a bird's-eye view in the x direction. At this time, in a cross section of the friction stir welded portion intersecting the x direction, when facing the advancing direction 30 of the tool T, a hooking defect F1 may occur on the left side of the advancing direction of the tool T (the side in the +y direction, a portion where the rotation direction 32 of the tool T and the advancing direction 30 of the tool T are opposite). This hooking defect F1 occurs because the stirring of the joint between the edge 6bh and the vehicle exterior panel 6a is insufficient, and therefore, although they are joined, they often do not satisfy the specified joining strength.

[0021] For this reason, when a force acts in a direction to peel the edge 6bh from the vehicle exterior panel 6a, there is a risk that the two will separate from each other, starting from a hooking defect F1 on the edge of the edge 6bh on the left side of the joining line L1 in the traveling direction (+y direction).The problem caused by the hooking defect F1 can be solved by friction stir welding the frame member 6b to the vehicle exterior panel 6a in a manner in which one edge of the joining line L1 partially overlaps with the joining line L2, as shown in Figure 7.

[0022] A method for solving the above problem will be described in detail. First, the tool T is rotated counterclockwise and advanced in the +x direction (first direction), and the bone member 6b is friction stir welded to the vehicle exterior panel 6a, thereby forming a weld line L1. Next, the same tool T is rotated counterclockwise and advanced in the -x direction (second direction) while viewing the weld line L1 to the left of the traveling direction of the tool T, and the bone member 6b is friction stir welded to the vehicle exterior panel 6a, thereby forming a weld line L2. At this time, the bone member 6b is friction stir welded to the vehicle exterior panel 6a such that a part of the weld line L2 in the width direction overlaps a part of the weld line L1. It is preferable that the weld line L2 and the weld line L1 overlap over the entire longitudinal direction.

[0023] By friction stir welding the frame member 6b to the vehicle exterior panel 6a along the weld lines L1 and L2 that are offset from each other using the above-mentioned method, a hooking Fl formed on the edge of the weld line L1 in the +y direction overlaps with a hooking defect F2 formed on the edge of the weld line L2 in the -y direction. Therefore, when the weld line F1 and the weld line L2 are macroscopically viewed as one weld line, welded parts with stable weld strength can be arranged on the edge of the weld line in the +y direction and the edge of the weld line in the -y direction (both sides of the weld line).

[0024] Therefore, even if a force is applied in a direction that pulls the frame member 6b away from the vehicle exterior panel 6a, neither side of the joint line viewed macroscopically is likely to become the starting point for separation, so the frame member 6b can be firmly connected to the vehicle exterior panel 6a.

[0025] If the frame members 6b are made of a lightweight alloy such as aluminum, and the car exterior panel 6a is made of a stainless steel plate (iron-based plate) having high strength and corrosion resistance and weather resistance, the weight of the entire side structure 6 can be reduced compared to when the entire structure is made of stainless steel plate. On the other hand, by arranging a material with a large mass in the car exterior panel 6a, a large transmission loss can be imparted to the side structure 6, so that the outside noise that penetrates the side structure 6 and enters the car interior can be reduced. Therefore, according to this embodiment, it is possible to provide a railway car structure that is highly reliable and lightweight, yet has a large transmission loss that can suppress the penetration of transmitted sound into the car interior.

[0026] Fig. 8 is a schematic top view showing the configuration of the upper floor panel, with a portion cut away. Fig. 9 is a cross-sectional view (GG cross section in Fig. 8) of the upper floor panel. The upper floor panel 72 is composed of a bone member 72b that forms an outer frame and has a substantially U-shaped cross section, an iron-based face plate 72a that is friction stir welded to one edge 72b1 of the bone member 72b, a back plate 72c that is fastened to the other edge 72b2 of the bone member 72b by a mechanical fastening part 72d, and a sound absorbing material 72e that is provided in the area surrounded by the bone member 72b, the face plate 72a, and the back plate 72c.

[0027] <Production method> For the upper floor panel 72, first, the face plate 72a cut into a predetermined shape is placed on a surface plate, and then the rib member 72b is positioned so that the edge portion 72b1 of the rib member 72b abuts against the face plate 72a.

[0028] Thereafter, a friction stir welding tool is brought into contact with the bone member 72b, rotated counterclockwise (around the left axis) when viewed from above, and advanced along the direction indicated by the tool advancement direction 30, thereby friction stir welding the bone member 72b and the face plate 72a together to form a joint line L1.

[0029] Next, a tool that rotates counterclockwise (around the left axis) when viewed from above is brought into contact with the bone member 72b and advanced in such a manner that the already joined weld line L1 is seen to the left of the moving direction of the tool, and the bone member 72b is friction stir welded to the face plate 72a to form the weld line L2. At this time, a part of the weld line L1 and a part of the weld line L2 overlap with each other, with the center line of the weld line L2 positioned outside the center line of the weld line L1.

[0030] By friction stir welding the bone member 72b to the face plate 72a along the joint line L1 and the joint line L2 using the above-mentioned method, the hooking Fl formed at the joint line L1 and the hooking F2 formed at the joint line L2 overlap each other. Therefore, when the joint line F1 and the joint line F2 are viewed macroscopically as a single joint line, joint portions with stable joint strength can be provided at both ends in the width direction of the joint line (both sides of the joint line).

[0031] Therefore, even if a force is applied in a direction that pulls the bone member 72b off the panel 72a, neither side of the joining line seen macroscopically is likely to become the starting point for separation, so the bone member 72b can be firmly connected to the panel 72a.

[0032] If necessary, sound-absorbing material 72e is provided in the area surrounded by face plate 72a and bone member 72b, and then back plate 72c is positioned on the upper surface of edge portion 72b2 of bone member 72b, and back plate 72c is joined to bone member 72b with mechanical fasteners 72d such as rivets.

[0033] If the frame members 72b are made of a lightweight alloy such as aluminum, and the face plate 72a is made of a stainless steel plate (iron-based plate) that has high strength and corrosion resistance and weather resistance, the weight of the entire upper floor panel 72 can be reduced compared to when the entire panel is made of stainless steel plate. On the other hand, by arranging a material with a large mass on the face plate 72a, a large transmission loss can be imparted to the upper floor panel 72, thereby reducing outside noise that penetrates the upper floor panel 72 and enters the vehicle interior.

[0034] Therefore, it is possible to provide a rail car structure that is highly reliable and lightweight, and yet has a structure with large transmission loss that can suppress the transmitted sound from the bogie 2 and various electrical equipment, which are likely to be sound sources, from entering the car interior even if they are located below the upper floor panel 72.

[0035] In addition, instead of the above-mentioned upper floor panel 72, an upper floor may be constructed by stacking an iron-based floor plate as an iron-based face plate on an aluminum alloy cross beam (floor beam) 12 as an aluminum-based frame member, and then inserting a friction stir welding tool T from the side of the cross beam 12, using a joining configuration similar to that of the upper floor panel 72.

[0036] More specifically, the cross beam 12 is brought into close contact with the steel-based floor plate, and the tool T is rotated counterclockwise while moving along a first direction to form a first weld line L1 where the cross beam 12 is friction stir welded to the steel-based face plate. The tool T is further rotated counterclockwise while moving along a second direction opposite to the first direction, with the first weld line L1 seen to the left of the moving direction of the tool T, to form a second weld line L2 where the cross beam 12 is friction stir welded to the steel-based face plate. At this time, a part of the first weld line L1 and a part of the second weld line L2 in the width direction are made to overlap.

[0037] FIG. 10 is a flow chart showing the process of joining the side structure and the upper floor panel. In step S10, the manufacturing process for joining the side structure 6 and the upper floor panel 72 is started. First, in step S20, the face plates 6a and 72a are placed on a surface plate. Next, in step S30, the frame members 6b and 72b are positioned on the face plates 6a and 72a.

[0038] Thereafter, in step S40, the tool rotating about the left axis is brought into contact with the bone members 6b, 72b and advanced in the direction of the tool advancement direction 30, thereby friction stir welding the face plates 6a, 72a and the bone members 6b, 72b together to form a first joint line L1. Furthermore, in step S50, the tool rotating about the left axis is brought into contact with the bone members 6b, 72b and advanced in a manner that the joint line L1 is seen to the left of the advancement direction (31), thereby friction stir welding the face plates 6a, 72a and the bone members 6b, 72b together to form a second joint line L2. In step S60, the joining process is completed.

[0039] A railway vehicle having a side structure or an upper panel manufactured by a manufacturing method including the above steps is characterized by being lightweight and having a large transmission loss that can suppress the intrusion of transmitted sound into the vehicle interior.

[0040] The present invention is not limited to the above embodiment. For example, the friction stir tool may be rotated clockwise, although the example in which the friction stir tool rotates counterclockwise has been given. In that case, however, when moving the tool along the second welding line, it is necessary to move the tool while viewing the first welding line to the right of the traveling direction. [Explanation of symbols]

[0041] 1...Railway vehicle, 2...Bogie, 3...structure, 5...roof structure, 6...Side structure, 6a...Vehicle exterior plate, 6b...Bone member (pillar), 6bh...Edge, 9...Gable structure, 12...Horizontal beam, 30, 31...Arrows showing the tool travel direction, 32...Arrow indicating the direction of tool rotation, 69…Partition wall, 70…Seat, 72...upper floor panel, 72a...face plate, 72b...bone member; 72b1, 72b2...edge portion; 72c...back plate, 72d...mechanical fastening part (rivet), 72e…sound absorbing material, 74…cabin partition wall, 76...Partition door, 90...Railway, 92...platform, L1, L2...joint line, F1, F2...hooking defect, T...tool, x...Longitudinal direction (rail direction), y...Width direction (sleeper direction), z: Height direction

Claims

[Claim 1] A frame forming the floor surface; Side structures erected at both ends in a width direction of the frame; An upper floor panel that constitutes the underframe; A method for manufacturing a railway vehicle structure having The side structure includes: a ferrous face plate formed from a ferrous material; an aluminum-based frame member that is placed on the vehicle interior side of the iron-based panel and is made of an aluminum-based material; It has The aluminum-based frame member has a top hat-shaped cross section intersecting a longitudinal direction of the aluminum-based frame member and has a pair of edges, The iron-based face plate and the edge portion are brought into close contact with each other, When a friction stir welding tool is brought into contact with the aluminum-based frame member from the side of the portion of the aluminum-based frame member that is in close contact with the steel-based face plate and the aluminum-based frame member, and the tool is rotated around its axis while moving the tool so as to overlap the welding lines, the steel-based face plate and the aluminum-based frame member are friction-stir-welded to each other, While rotating the tool around a counterclockwise axis, the tool is advanced along a first direction to form a first weld line by friction stir welding the edge portion to the ferrous face plate; While rotating the tool counterclockwise, the tool is advanced along a second direction opposite to the first direction while viewing the first welding line to the left of the traveling direction of the tool, thereby forming a second welding line by friction stir welding the edge portion to the iron-based face plate; A part of the first weld line and a part of the second weld line in the width direction of the aluminum-based frame member are overlapped so that a hook defect caused by the friction stir welding to form the first weld line overlaps with a hook defect caused by the friction stir welding to form the second weld line. A method for manufacturing a railway vehicle body structure comprising:

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