Weld structure

Abstract

To provide a weld structure in which stress concentration of a root part can be reduced regardless of a metal material to be welded.SOLUTION: A connection member 30 includes a projection part 34 projecting further from a first end surface 32. The projection part 34 includes a first surface 34A formed so as to extend along a direction continuous from the first end surface 32 and orthogonal to the first end surface 32. A pillar skeleton member 40 includes: a second surface 42A overlapped with the first surface 34A; and a second end surface 44 arranged so as to face the first end surface 32 and formed so as to be continuous from the second surface 42A. The second end surface 44 is joined to the first end surface 32 of the connection member 30 by arc welding. The first surface 34A of the projection part 34 is formed with a recess 38 facing at least a part between the first end surface 32 and the second end surface 44. Among opening edges 38A, 38B of the recess 38, the opening edge 38B being a portion located opposite to the first end surface 32 side contacts a boundary between the second end surface 44 and the second surface 42A. The recess 38 is filled with a part 60A of a weld metal 60.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a welded structure. [Background technology]

[0002] Patent Document 1 below discloses a technique related to lap fillet arc welded joints. Briefly, in this prior art, a region on one end of one steel plate is bent, and the region on that end of the other steel plate is arranged non-parallel and facing each other, and a weld bead is formed between these regions. The bend angle on the one end of the one steel plate is limited to prevent molten metal from flowing out of the gap during fillet arc welding, and an appropriate weld bead is formed to alleviate stress concentration in the root portion on the one end of the other steel plate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6278291 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the above-mentioned prior art is for welding steel plates together, but does not anticipate welding of metal materials other than steel. If another metal plate is used instead of the steel plate of the above-mentioned prior art and the viscosity of the metal to be used as the weld bead is low, the molten metal will flow out, making it difficult to properly form the weld bead. In this respect, there is room for improvement.

[0005] In consideration of the above, an object of the present invention is to provide a welded structure capable of reducing stress concentration at the root regardless of the metal materials to be welded. [Means for solving the problem]

[0006] A first aspect of the welded structure includes a first member having a convex portion that further protrudes from a first end face, which is a predetermined end face, in a direction toward the first end face, the convex portion having a first surface that is continuous with the first end face and formed along a direction perpendicular to the first end face; and a second member having a second surface that overlaps the first surface of the first member and has a second end surface that is arranged opposite the first end face of the first member and is continuous with the second surface, the second end surface being joined to the first end face by arc welding. A concave portion is formed in the first surface of the convex portion so as to face at least between the first end face and the second end face, and a portion of the opening edge of the concave portion that is located opposite the first end face is formed so as to contact the boundary between the second end face and the second surface or the second surface, and a portion of the concave portion is filled with weld metal.

[0007] According to the first aspect of the welded structure, the first member has a protrusion that protrudes further from a first end face, which is a predetermined end face, in a direction toward the first end face, and the protrusion of the first member has a first surface that is continuous with the first end face and formed along a direction perpendicular to the first end face. In contrast, the second member has a second surface that overlaps the first surface of the first member and has a second end face that is disposed opposite the first end face of the first member and is formed continuous with the second surface, and the second end face of the second member is joined to the first end face of the first member by arc welding.

[0008] Here, a recess is formed in the first surface of the convex portion so as to face at least between the first end surface and the second end surface, and a portion of the opening edge of the recess located on the opposite side from the first end surface is formed so as to contact the boundary between the second end surface and the second surface or the second surface, and a portion of the weld metal is filled in the recess. Therefore, another portion of the weld metal can be favorably arranged (without poor penetration) between the second end surface of the second member and the first end surface of the first member, and the joining area of ​​the second end surface of the second member can be maximized, thereby mitigating stress concentration at the second end surface of the second member (in other words, the root portion).

[0009] A welded structure of a second aspect is the welded structure of the first aspect, wherein the first member is a casting.

[0010] According to the welded structure of the second aspect, the first member is a casting, so that the recess can be easily formed.

[0011] A welded structure of a third aspect is the welded structure of the first or second aspect, wherein the second member has a fitted portion into which a convex portion of the first member is fitted and which forms the second surface; The first surface of the first member is formed in multiple locations on the outer peripheral surface of the convex portion, and the second surface of the second member is formed in multiple locations corresponding to the multiple first surfaces, and the recesses are formed on all of the multiple first surfaces, and a portion of the weld metal is filled in all of the recesses.

[0012] According to a third aspect of the welded structure, the second member has a fitted portion that includes the second surface, and the protruding portion of the first member is fitted into the fitted portion of the second member. Furthermore, the first member has a plurality of first surfaces formed on the outer peripheral surface of the protruding portion, and the second member has a plurality of second surfaces formed corresponding to the plurality of first surfaces, with recesses formed in all of the plurality of first surfaces and with a portion of the weld metal filling all of the recesses. Therefore, in a configuration in which the protruding portion of the first member is fitted into the fitted portion of the second member, it is possible to alleviate stress concentration on the second end face (in other words, the root portion) of the second member. [Effects of the Invention]

[0013] As described above, the welded structure according to the present invention has the excellent effect of being able to alleviate stress concentration at the root regardless of the metal materials to be welded. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a perspective view showing a portion of a welded structure according to an embodiment of the present invention. [Figure 2] 2 is an enlarged cross-sectional view of the upper part of the welded structure of FIG. 1 taken along line 2-2. FIG. [Figure 3] 2 is an exploded perspective view showing the members constituting the welded structure of FIG. 1 in a state before welding. FIG. [Figure 4] 2 is a side view schematically showing a vehicle to which the welded structure of FIG. 1 is applied. DETAILED DESCRIPTION OF THE INVENTION

[0015] A welded structure according to one embodiment of the present invention will be described with reference to Figures 1 to 4. Figure 4 schematically shows a vehicle (automobile) 10 to which the welded structure according to this embodiment is applied. Note that the arrow FR shown in Figure 4 indicates the front side of the vehicle, and the arrow UP indicates the upper side of the vehicle.

[0016] (Configuration of the embodiment) 4, the welded structure 20 has a connecting member 30 as a first member arranged near the front end of the outer portion of the roof portion 12 of the vehicle 10 in the vehicle width direction, and a pillar framework member 40 as a second member provided on the outer portion of the front end of the cabin in the vehicle width direction, with the rear end side of the pillar framework member 40 and the front end side of the connecting member 30 joined by arc welding. The pillar framework member 40 is configured as a columnar vehicle body framework member with a hollow closed cross-section structure, and is also called a front pillar.

[0017] Furthermore, as an example, the welded structure 20 has a roof frame member 50 as a second member arranged along the vehicle front-rear direction on the outer side in the vehicle width direction of the roof portion 12 of the vehicle 10, and the front end side of the roof frame member 50 and the rear end side of the connecting member 30 are joined by arc welding. The roof frame member 50 is configured as a beam-shaped vehicle body frame member with a hollow closed cross-section structure, and is also called a roof side rail.

[0018] The connecting member 30, the pillar frame member 40, and the roof frame member 50 are all made of metal (aluminum alloy, for example). The connecting member 30 is a casting, and the pillar frame member 40 and the roof frame member 50 are all made of extruded material. The structure of the welded portion between the rear end of the pillar frame member 40 and the front end of the connecting member 30 is substantially the same as the structure of the welded portion between the front end of the roof frame member 50 and the rear end of the connecting member 30.

[0019] Fig. 1 shows a perspective view of a portion of the welded structure 20, and Fig. 2 shows an enlarged cross-sectional view of the upper part of the welded structure 20 shown in Fig. 1 taken along line 2-2. Also, Fig. 3 shows an exploded perspective view of the pillar frame member 40 and the connecting member 30 that constitute the welded structure 20 shown in Fig. 1 before arc welding.

[0020] 3, the connecting member 30 is formed, for example, in a substantially rectangular cylindrical shape, and includes a protrusion 34 that protrudes further from a first end face 32, which is a predetermined end face, in the direction in which the first end face 32 faces. The first end face 32 is formed in a rectangular frame shape, and the protrusion 34 is formed in a square cylindrical shape. The protrusion 34 includes a first surface 34A that is continuous with the first end face 32 and is formed along a direction perpendicular to the first end face 32, and a plurality of first surfaces 34A (four, for example) are formed on the outer circumferential surface of the protrusion 34.

[0021] As an example, the pillar frame member 40 is formed in a substantially rectangular cylindrical shape and has, at its end in the axial direction of the cylinder, a fitted portion 42 into which the protrusion 34 of the connecting member 30 is fitted. As shown in FIG. 2, the pillar frame member 40 has a second surface 42A overlapping the first surface 34A of the connecting member 30. The second surface 42A is a component of the fitted portion 42 (see FIG. 3), and a plurality of second surfaces 42A (four in this example) are formed corresponding to the plurality of first surfaces 34A shown in FIG. 3. As shown in FIG. 2, the pillar frame member 40 has a second end surface 44 arranged to face the first end surface 32 of the connecting member 30, and the second end surface 44 is formed contiguous with the second surface 42A. The second end surface 44 of the pillar frame member 40 is joined to the first end surface 32 of the connecting member 30 by arc welding (with weld metal 60).

[0022] Furthermore, a recess 38 (a recessed portion below the two-dot chain line L in the drawing) is formed on the first surface 34A of the protruding portion 34 of the connecting member 30 so as to face at least between the first end surface 32 of the connecting member 30 and the second end surface 44 of the pillar frame member 40, and a portion 60A of the weld metal 60 is filled in the recess 38. The portion of the recess 38 filled with the portion 60A of the weld metal 60 can be understood as a molten pool. The recess 38 shown in FIG. 3 is formed in a groove shape around the entire outer periphery of the protruding portion 34 of the connecting member 30, and is formed on all of the multiple (four) first surfaces 34A. Furthermore, in the welded structure 20 shown in FIG. 1, all of the recesses 38 are filled with a portion 60A of the weld metal 60 (see FIG. 2).

[0023] 2, the recess 38 is formed, for example, in an inverted triangular shape that is most recessed in the center in the width direction (left-right direction in the figure). Note that the recess 38 shown in Fig. 2 can have a depth 38D that is set to, for example, about 1 / 4 (20% to 30%) of the plate thickness 42T of the fitted portion 42 of the pillar frame member 40.

[0024] Furthermore, the width dimension (the dimension in the left-right direction in the drawing) of the recess 38 is, for example, the same as the distance between the first end face 32 of the connecting member 30 and the second end face 44 of the pillar frame member 40. Of the opening edges 38A, 38B of the recess 38, the portion 38A located on the first end face 32 side is formed so as to be continuous with the first end face 32. Of the opening edges 38A, 38B of the recess 38, the portion 38B located on the opposite side from the first end face 32 side (the left side in the drawing) is formed so as to contact the boundary between the second end face 44 and the second surface 42A.

[0025] Here, to briefly explain the arrangement state before arc welding, in the initial state in which the second surface 42A of the pillar skeleton member 40 is overlapped on the first surface 34A of the connecting member 30 in order to arc-weld the connecting member 30 and the pillar skeleton member 40 together, the tip end of the pillar skeleton member 40 has not yet melted due to the heat of arc welding, and therefore the position of the tip end surface of the pillar skeleton member 40, although not shown, is located to the right in the figure of the second end surface 44 of the pillar skeleton member 40 shown in Fig. 2. In other words, the width dimension (the dimension in the left-right direction in the figure) of the recess 38 is set to a dimension such that part of the recess 38 is blocked by the pillar skeleton member 40 in the initial state in which the second surface 42A of the pillar skeleton member 40 is overlapped on the first surface 34A of the connecting member 30 in order to arc-weld the connecting member 30 and the pillar skeleton member 40 together.

[0026] (Actions and Effects of the Embodiments) Next, the operation and effects of this embodiment will be described.

[0027] 2 , the connecting member 30 has a protrusion 34 that protrudes further from the first end face 32 in the direction in which the first end face 32 faces, and the protrusion 34 of the connecting member 30 has a first surface 34A that is continuous with the first end face 32 and is formed along a direction perpendicular to the first end face 32. In contrast, the pillar frame member 40 has a second surface 42A that overlaps the first surface 34A of the connecting member 30, and has a second end surface 44 that is disposed so as to face the first end face 32 of the connecting member 30 and is formed so as to be continuous with the second surface 42A, and the second end surface 44 of the pillar frame member 40 is joined to the first end face 32 of the connecting member 30 by arc welding (with weld metal 60).

[0028] Here, a recess 38 is formed in the first surface 34A of the protrusion 34 so as to face at least between the first end surface 32 of the connecting member 30 and the second end surface 44 of the pillar frame member 40, and a portion 38B of the opening edges 38A, 38B of the recess 38, which is located on the opposite side from the first end surface 32, is formed so as to contact the boundary between the second end surface 44 and the second surface 42A, and a portion 60A of the weld metal 60 is filled in the recess 38. Therefore, the other portion 60B of the weld metal 60 can be disposed favorably (without insufficient penetration) between the second end surface 44 of the pillar frame member 40 and the first end surface 32 of the connecting member 30. This maximizes the joining area of ​​the second end surface 44 of the pillar frame member 40, thereby alleviating stress concentration on the second end surface 44 of the pillar frame member 40 (in other words, the root portion) and improving the strength of the joint portion at the root portion.

[0029] As a supplementary explanation, when arc welding is performed using a welding torch, it is not possible to pinpoint the portion to be welded, and therefore, for example, in a comparative structure in which the recess 38 is not formed, when arc welding is performed using a welding torch, poor arc welding penetration is likely to occur in a portion of the root portion, which is the portion on the tip side of the pillar frame member 40, adjacent to the first surface 34A of the convex portion 34 of the connecting member 30. In contrast, in the present embodiment, the recess 38 is formed, and therefore, during arc welding, the molten metal first fills the recess 38 and then fills the space between the second end surface 44 of the pillar frame member 40 and the first end surface 32 of the connecting member 30, and therefore the portion of the root portion on the tip side of the pillar frame member 40 adjacent to the first surface 34A of the convex portion 34 of the connecting member 30 can also be well welded.

[0030] Furthermore, in this embodiment, the second surface 42A of the pillar frame member 40 is a component of the fitted portion 42 shown in Fig. 3, and the protruding portion 34 of the connecting member 30 is fitted into the fitted portion 42 of the pillar frame member 40. Furthermore, a plurality of first surfaces 34A of the connecting member 30 are formed on the outer peripheral surface of the protruding portion 34, and a plurality of second surfaces 42A of the pillar frame member 40 shown in Fig. 2 are formed corresponding to the plurality of first surfaces 34A, and recesses 38 are formed on all of the plurality of first surfaces 34A, and a portion of the weld metal 60 is filled in all of the recesses 38. Therefore, in a configuration (spigot joint structure) in which the protruding portion 34 of the connecting member 30 shown in Fig. 1 is fitted into the fitted portion 42 of the pillar frame member 40 (see Fig. 3), it is possible to alleviate stress concentration on the second end surface 44 (in other words, the root portion) of the pillar frame member 40 shown in Fig. 2.

[0031] Furthermore, although detailed explanation will be omitted, the structure of the welded portion between the rear end side of the connecting member 30 and the front end side of the roof frame member 50 shown in FIG. 4 is substantially the same as the structure of the welded portion between the front end side of the connecting member 30 and the rear end side of the pillar frame member 40 described above, and therefore, the same effect can be obtained as with the structure of the welded portion between the rear end side of the pillar frame member 40 and the front end side of the connecting member 30 described above.

[0032] As described above, according to this embodiment, stress concentration at the root can be reduced regardless of the metal material to be welded.

[0033] Furthermore, according to this embodiment, since the connecting member 30 is a casting, the recesses 38 shown in FIGS. 1 to 3 can be easily formed.

[0034] (Supplementary explanation of the embodiment) In the above embodiment, as shown in FIG. 2, the portion 38B of the opening edges 38A, 38B of the recess 38 that is located on the opposite side to the first end face 32 is formed so as to contact the boundary between the second end face 44 and the second surface 42A. However, as a variation of the above embodiment, the portion (38B) of the opening edges (38A, 38B) of the recess (38) that is located on the opposite side to the first end face (32) may be formed so as to contact the second surface (42A).

[0035] 1 to 4, as an example, a case has been described in which the welded structure 20 is provided in a portion including a front pillar portion and a roof side portion, the first member being a connecting member 30, and the second member being a pillar frame member 40 and a roof frame member 50. However, the arrangement position of the welded structure of the present invention and the first and second members are not limited thereto. For example, the configuration of the welded structure of the present invention may be applied to a vehicle body structure 70 (schematically illustrated in the figure) in which a plurality of members are arranged to extend along the vehicle front-rear direction near the inner side of the front fender portion 14 in the vehicle width direction and arc-welded together. The vehicle body structure 70 may include, for example, a front member 72 formed as a cast product, a rear member 74 also formed as a cast product, and an intermediate member 76 formed as an extruded material and connecting the front member 72 and the rear member 74, with the front member 72 and the rear member 74 functioning as the first member and the intermediate member 76 functioning as the second member.

[0036] Furthermore, in the above embodiment shown in Figures 1 to 4, as an example, the connecting member 30 as the first member is a cast product, but as a variation of the above embodiment, a configuration in which the first member is other than a cast product may also be adopted.

[0037] Furthermore, in the above embodiment, as an example, the pillar frame member 40 and the roof frame member 50 as the second member are both made of extruded material, but as a variation of the above embodiment, the second member may also be made of a material other than an extruded material, such as a panel material that is not an extruded material.

[0038] Furthermore, in the above embodiment, the pillar frame member 40 as the second member has an insertable portion 42 into which the convex portion 34 of the connecting member 30 as the first member is inserted, but as a variation of the above embodiment, the second member may be configured not to have an insertable portion into which the convex portion of the first member is inserted.

[0039] Furthermore, in the above embodiment, the connecting member 30 as the first member, and the pillar frame member 40 and the roof frame member 50 as the second members are all made of an aluminum alloy, for example, but the first member and the second member may also be made of a metal other than an aluminum alloy, such as steel.

[0040] The above-described embodiment and the above-described modifications can be implemented in appropriate combinations.

[0041] The above describes one example of the present invention, but the present invention is not limited to the above, and it goes without saying that the present invention can be implemented in various modified forms within the scope of the gist of the present invention. [Explanation of symbols]

[0042] 20 Welded Structure 30 Connecting member (first member) 32 First end surface 34 Convex part 34A Front page 38 Recess 38A Recessed opening edge 38B: Opening edge of recess (portion of opening edge of recess located on the opposite side to the first end face) 40 Pillar frame member (second member) 42 Inserted part 42A Second side 44 Second end face 50 Roof frame member (second member) 60 Weld Metal 60A Part of weld metal

Claims

1. a first member including a convex portion that further protrudes from a first end face that is a predetermined end face in a direction in which the first end face faces, the convex portion having a first surface that is continuous with the first end face and is formed along a direction perpendicular to the first end face; a second member including a second surface overlapping the first surface of the first member, and a second end surface disposed opposite the first end surface of the first member and formed continuously with the second surface, the second end surface being joined to the first end surface by arc welding; and a recess is formed on the first surface of the convex portion so as to face at least between the first end surface and the second end surface, a portion of an opening edge of the recess located on the opposite side to the first end surface is formed so as to contact the boundary between the second end surface and the second surface or the second surface, and a portion of the weld metal is filled in the recess.

2. The welded structure of claim 1 , wherein the first member is a casting.

3. the second member includes a fitted portion into which the convex portion of the first member is fitted and which constitutes the second surface; 2. The welded structure according to claim 1, wherein the first surface of the first member is formed on an outer peripheral surface of the convex portion, the second surface of the second member is formed on a plurality of surfaces corresponding to the plurality of first surfaces, the recesses are formed on all of the plurality of first surfaces, and all of the recesses are filled with a portion of the weld metal.

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