Joint structure

Abstract

A recess (11) is formed in the first member (10). The third member (30) is welded to the first member (10) via a through portion (21) of the second member (20). The third member (30) has a protrusion (32) extending radially outward from the interior of the recess (11). The second member (20) is compressed and fixed between the first member (10) and the third member (30) by the solidification shrinkage of the third member (30).

Description

Technical Field

[0001] This invention relates to joining structures. Background Technology

[0002] Patent Document 1 discloses a joint structure obtained by arc welding of a solder (welding wire) through a through portion of a dissimilar material, in which a first metal material is overlapped with a dissimilar material that is difficult to weld relative to the first metal material.

[0003] At this point, molten solder is used to form an overhang on the outer periphery of the upper surface of the through-hole of the dissimilar material. Thus, under the compressive force of the overhang, generated by the solidification and shrinkage of the solder relative to the first metal material, the dissimilar material and the first metal material are fixed together.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: International Publication No. 2018 / 030272 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] However, in the invention of Patent Document 1, for example, when the aperture of the through portion is small, the bonding area of ​​the solder in the first metal material also becomes small, and the bonding strength may be insufficient.

[0009] The present invention was made in view of this point, and its purpose is to increase the bonding area of ​​the solder and thus ensure the bonding strength.

[0010] Solution for solving the problem

[0011] The first invention is a joining structure formed by joining a first component made of a metallic material, a second component made of a material that is difficult to weld relative to the first component, and a third component made of solder welded to the first component. The structure is characterized in that at least one of the first component and the second component has a recess formed on the overlapping surface of the first component and the second component; the second component has a through portion that opens at a position corresponding to the recess and has an inner diameter smaller than the opening width of the recess; the third component has a protrusion welded to the first component via the through portion and extending radially outward from the through portion inside the recess; and the second component is compressed and fixed between the first component and the third component by the solidification shrinkage of the third component relative to the first component.

[0012] In the first invention, a recess is formed in at least one of the first member and the second member. A third member is welded to the first member via a through portion of the second member. The third member has a protrusion extending radially outward from the interior of the recess. The second member is compressed and fixed between the first member and the third member by the solidification shrinkage of the third member.

[0013] Thus, by providing a recess in at least one of the first and second components, and welding the molten third component to the first component while extending radially outward within the recess, the joint area of ​​the third component can be increased. This ensures the joint strength of the first, second, and third components.

[0014] In the second invention, based on the first invention, the recess is formed in the first member.

[0015] In the second invention, a recess is formed in the first member. This allows for a reduction in the thickness of the first member, thereby obtaining the heat input required for the melting depth of the first member.

[0016] In the third invention, based on the first or second invention, the recess is formed in the second member.

[0017] In the third invention, a recess is formed in the second member. Thus, even if the thickness of the first member is so thin that it is difficult to form a recess in the first member, by providing a recess in the second member and expanding the molten third member inside the recess, the bonding area of ​​the third member can be increased.

[0018] In the fourth invention, based on any of the first to third inventions, the recess has a curved portion that bends toward the bottom of the recess.

[0019] In the fourth invention, a curved portion is provided in the recessed portion. The curved portion bends towards the bottom of the recessed portion. As a result, the contact area of ​​the third member can be increased compared to the case where the bottom of the recessed portion is a flat surface. In addition, the molten third member can easily flow towards the central side of the through portion.

[0020] In the fifth invention, based on any of the first to third inventions, the recess has an inclined portion that slopes toward the bottom of the recess.

[0021] In the fifth invention, an inclined portion is provided in the recessed portion. The inclined portion slopes towards the bottom of the recessed portion. As a result, compared to the case where the bottom of the recessed portion is a flat surface, the contact area of ​​the third member can be increased. In addition, the molten third member can more easily flow towards the central side of the through portion.

[0022] In the sixth invention, based on any one of the first to third inventions, the recess has a first recess and a second recess formed at the bottom of the first recess.

[0023] In the sixth invention, a second recess is formed at the bottom of the first recess. This increases the contact area of ​​the third member compared to the case where the bottom of the first recess is flat.

[0024] Invention Effects

[0025] According to the present invention, the bonding area of ​​the solder can be increased to ensure the bonding strength. Attached Figure Description

[0026] Figure 1 This is a side sectional view used to illustrate the joining structure of Embodiment 1.

[0027] Figure 2 This is a side sectional view used to illustrate the joining structure of Embodiment 2.

[0028] Figure 3 This is a side sectional view used to illustrate the joining structure of Embodiment 3.

[0029] Figure 4 This is a side sectional view used to illustrate the joining structure of Embodiment 4.

[0030] Figure 5 This is a side sectional view used to illustrate the joining structure of Embodiment 5.

[0031] Figure 6 This is a side sectional view used to illustrate the joining structure of Embodiment 6.

[0032] Figure 7 This is a side sectional view used to illustrate the joining structure of Embodiment 7.

[0033] Figure 8 This is a side sectional view used to illustrate the joining structure of Embodiment 8.

[0034] Figure 9 This is a side sectional view used to illustrate the joining structure of Embodiment 9.

[0035] Figure 10 This is a top view showing the structure of the first component of this embodiment 10.

[0036] Figure 11 This is a side sectional view used to illustrate the joint structure.

[0037] Figure 12 This is a top view showing the structure of the first component of this embodiment 11.

[0038] Figure 13 This is a side sectional view used to illustrate the joint structure. Detailed Implementation

[0039] The embodiments of the present invention will now be described with reference to the accompanying drawings. It should be noted that the following description of preferred embodiments is merely illustrative and is not intended to limit the invention, its applicability, or its uses.

[0040] Implementation Method 1

[0041] Figure 1 A joining structure is shown for joining a first component 10 made of metallic material, a second component 20 made of a material that is difficult to weld relative to the first component 10, and a third component 30 made of solder together.

[0042] The first component 10 is a plate-shaped component made of metallic material. The first component 10 has a recess 11 formed with a depth that does not penetrate in the thickness direction. The recess 11 is formed at the overlapping surface of the first component 10 and the second component 20. Figure 1 In the example shown, the recess 11 is formed by a circular recess that opens upwards. The opening width of the recess 11 is larger than the inner diameter of the through portion 21 of the second member 20, which will be described later. The recess 11 is formed, for example, by lathe machining or laser machining.

[0043] The second component 20 is a plate-shaped component made of a material that is more difficult to weld than the first component 10. The upper side of the second component 20 coincides with that of the first component 10. The second component 20 has a circular through-hole 21. The through-hole 21 opens at a position corresponding to the recess 11 of the first component 10. The inner diameter of the through-hole 21 is smaller than the opening width of the recess 11.

[0044] It should be noted that in this embodiment, the through portion 21 is described as a circular through hole, but it can also be a through groove. Alternatively, it can be an elliptical or elongated through hole.

[0045] The third component 30 is made of solder, which is a metal material of the same type as the first component 10. Here, "metal material of the same type" means metals that can be welded together, not only between metals of the same material, but also between ferrous metals, non-ferrous metals, and other metal materials with good weldability. In other words, "metal material of the same type" means metals of the same type with good weldability.

[0046] Specifically, the combinations of the first component 10 and the third component 30 during welding can be listed below. For example, combinations of ferrous metal materials include mild steel and mild steel, stainless steel and stainless steel, mild steel and high-strength steel (high-tensile steel), high-strength steel and high-strength steel, etc. In addition, combinations of non-ferrous metal materials include aluminum and aluminum, aluminum and aluminum alloys, aluminum alloys and aluminum alloys, etc.

[0047] Furthermore, the second component 20, being a dissimilar material, is made of a different material than the first component 10 and the third component 30, which are made of the same type of metal, and is a material that is more difficult to weld than the first component 10 and the third component 30.

[0048] For example, if the first component 10 and the third component 30, which are metal materials of the same type, are ferrous metal materials, the second component 20, which is a dissimilar material, is a non-ferrous metal material such as copper or aluminum.

[0049] It should be noted that the following description refers to the case where mild steel is used as the first component 10, aluminum is used as the second component 20, and mild steel is used as the third component 30 as solder.

[0050] The arc welding machine 1 includes a nozzle 2 and a welding nozzle 3. The nozzle 2 supplies shielding gas, etc., to the welding position of the object being welded. The welding nozzle 3 supplies welding current to the third component 30.

[0051] The arc welding machine 1 generates an arc 5 by simultaneously feeding a third member 30, which serves as a welding electrode, into the recess 11 via the through section 21. The third member 30, molten by arc welding, is fused to the first member 10 and stacked within the through section 21. Inside the recess 11, the molten third member 30 extends radially outward beyond the through section 21.

[0052] Furthermore, after the molten third component 30 fills the through portion 21, it flows out toward the periphery of the upper surface side of the through portion 21 and expands in a flange shape.

[0053] During the process of the molten third component 30 becoming a weld bead, a flange portion 31 and a protrusion portion 32 are provided on the third component 30.

[0054] The flange portion 31 is located on the side of the second member 20 opposite to the first member 10. Figure 1 The upper surface (the middle part) extends radially outward from the through part 21. The flange part 31 presses against the periphery of the through part 21.

[0055] The protrusion 32 extends radially outward from the recess 11 of the first member 10 compared to the through portion 21. The protrusion 32 is welded to the first member 10.

[0056] In this embodiment, the first member 10 has an inner peripheral surface 11a that defines a recess 11 formed on the overlapping surface of the first member 10 and the second member 20, and defines the area of ​​the recess 11 that contacts the overlapping surface of the first member 10 and the second member 20, and a bottom surface 11b that defines the bottom side of the recess 11. A protrusion 32 is located within the recess 11. A gap 11c is formed between the protrusion 32 and the inner peripheral surface 11a.

[0057] Furthermore, the third component 30 solidifies and shrinks relative to the first component 10, thereby compressing and fixing the second component 20, which is a dissimilar material, between the flange portion 31 and the first component 10.

[0058] It should be noted that the molten third component 30 becomes a weld bead, and the part that becomes the flange 31 slightly melts and combines with the second component 20 to form an intermetallic compound. There may be some brittle parts, but the strength is not ensured by the molten surface that is the contact part, but by using the rigidity of the flange 31 to press the periphery of the through part 21 to ensure the strength.

[0059] As described above, according to the joining structure of this embodiment, a recess 11 is provided in the first member 10, and the molten third member 30 is welded to the first member 10 while extending radially outward inside the recess 11, thereby increasing the joining area of ​​the third member 30. In particular, when the thickness of the first member 10 is greater than that of the second member 20, the thermal impact on the second member 20 can be minimized while ensuring the penetration depth of the first member 10.

[0060] This ensures the strength of the connection between the first component 10, the second component 20, and the third component 30.

[0061] Implementation Method 2

[0062] Hereinafter, the same reference numerals will be used to mark the same parts as in Embodiment 1, and only the differences will be explained.

[0063] like Figure 2 As shown, the second member 20 has a through portion 21 that opens at a position corresponding to the recess 11 of the first member 10. The through portion 21 has a tapered portion 22 that tapers toward the front end of the first member 10. The inner diameter of the lower end side of the through portion 21 is smaller than the opening width of the recess 11.

[0064] The third component 30 is fused by arc welding. The molten third component 30 flows along the tapered portion 22 of the through portion 21 toward the recess 11 and is fused together with the first component 10. Inside the recess 11, the molten third component 30 extends radially outward from the through portion 21.

[0065] Furthermore, the molten third component 30 fills the through portion 21, thereby extending in a flange shape on the upper surface of the cone portion 22.

[0066] During the process of forming a weld bead in the molten third component 30, a flange portion 31 and a protrusion portion 32 are provided on the third component 30. The flange portion 31 presses against the tapered portion 22 of the through portion 21. The protrusion portion 32 extends radially outward from the recess 11 of the first component 10. The protrusion portion 32 is welded to the first component 10.

[0067] Furthermore, the third component 30 solidifies and shrinks relative to the first component 10, thereby compressing and fixing the second component 20, which is a dissimilar material, between the flange portion 31 and the first component 10.

[0068] As described above, according to the joining structure of this embodiment, a tapered portion 22 is provided in the through portion 21, so that the molten third member 30 can easily flow toward the recessed portion 11. In addition, by solidifying the flange portion 31 into a shape along the tapered portion 22, the thickness of the flange portion 31 protruding from the second member 20 can be suppressed.

[0069] Implementation Method 3

[0070] like Figure 3 As shown, the second member 20 has a surface on the side opposite to the first member 10 (in... Figure 3 The stepped portion 25 (with the upper surface in the middle) has an opening, and a through portion 21 is formed on the bottom surface of the stepped portion 25. The inner diameter of the through portion 21 is smaller than the opening width of the recessed portion 11.

[0071] The third component 30 is fused together by arc welding. The molten third component 30 is fused together with the first component 10. Inside the recess 11, the molten third component 30 extends radially outward compared to the through portion 21.

[0072] Furthermore, after the molten third component 30 fills the through portion 21, it flows out toward the periphery of the upper surface side of the through portion 21, that is, the bottom surface of the step portion 25, and expands in a flange shape.

[0073] During the process of forming a weld bead in the molten third component 30, a flange portion 31 and a protrusion portion 32 are provided on the third component 30. The flange portion 31 presses against the periphery of the through portion 21. The protrusion portion 32 extends radially outward from the recess 11 of the first component 10. The protrusion portion 32 is welded to the first component 10.

[0074] Furthermore, the third component 30 solidifies and shrinks relative to the first component 10, thereby compressing and fixing the second component 20, which is a dissimilar material, between the flange portion 31 and the first component 10.

[0075] As described above, according to the joining structure of this embodiment, the flange portion 31 of the third member 30 is disposed within the step portion 25, thereby preventing the flange portion 31 from protruding from the second member 20.

[0076] Implementation Method 4

[0077] like Figure 4 As shown, the second member 20 has a surface on the side opposite to the first member 10 (in... Figure 4 The stepped portion 25 (with the upper surface in the middle) has an opening, and a through portion 21 is formed on the bottom surface of the stepped portion 25. The bottom surface of the stepped portion 25 is inclined toward the through portion 21. The inner diameter of the through portion 21 is smaller than the opening width of the recessed portion 11.

[0078] The third component 30 is fused together by arc welding. The molten third component 30 is fused together with the first component 10. Furthermore, when the molten third component 30 is engaged with the inclined surface of the step portion 25, it flows along the inclined surface of the step portion 25 toward the through portion 21 and is fused together with the first component 10. Inside the recess 11, the molten third component 30 extends radially outward beyond the through portion 21.

[0079] Furthermore, after the molten third component 30 fills the through portion 21, it flows out toward the periphery of the upper surface side of the through portion 21, i.e., the bottom surface of the step portion 25, and extends in a flange shape on the inclined surface of the step portion 25.

[0080] During the process of forming a weld bead in the molten third component 30, a flange portion 31 and a protrusion portion 32 are provided on the third component 30. The flange portion 31 presses against the inclined surface of the stepped portion 25. The protrusion portion 32 extends radially outward from the recess 11 of the first component 10 compared to the through portion 21. The protrusion portion 32 is welded to the first component 10.

[0081] Furthermore, the third component 30 solidifies and shrinks relative to the first component 10, thereby compressing and fixing the second component 20, which is a dissimilar material, between the flange portion 31 and the first component 10.

[0082] As described above, according to the joining structure of this embodiment, the bottom surface of the step portion 25 is inclined toward the through portion 21, so that the molten third component 30 can easily flow toward the through portion 21.

[0083] In addition, by placing the flange portion 31 of the third member 30 within the stepped portion 25, it is possible to suppress the flange portion 31 from protruding from the second member 20.

[0084] Implementation Method 5

[0085] like Figure 5As shown, the second member 20 has a through portion 21 that opens at a position corresponding to the recess 11 of the first member 10. The inner diameter of the through portion 21 is smaller than the opening width of the recess 11.

[0086] The third component 30 is fused together by arc welding. The molten third component 30 is fused together with the first component 10. Inside the recess 11, the molten third component 30 extends radially outward compared to the through portion 21.

[0087] Furthermore, the nozzle 2 of the arc welding machine 1 is rotated along the periphery of the through section 21, thereby supplying the periphery of the through section 21 with molten third component 30. As a result, the molten third component 30 fills the through section 21 and extends in a flange shape on the periphery of the upper surface side of the through section 21.

[0088] During the process of forming a weld bead in the molten third component 30, a flange portion 31 and a protrusion portion 32 are provided on the third component 30. The flange portion 31 presses against the periphery of the through portion 21. The protrusion portion 32 extends radially outward from the recess 11 of the first component 10. The protrusion portion 32 is welded to the first component 10.

[0089] Furthermore, the third component 30 solidifies and shrinks relative to the first component 10, thereby compressing and fixing the second component 20, which is a dissimilar material, between the flange portion 31 and the first component 10.

[0090] As described above, according to the joining structure of this embodiment, the nozzle 2 of the arc welding machine 1 is rotated to perform arc welding on the periphery of the through portion 21 in a spiral trajectory based on AC welding and short-circuit welding with low heat input, thereby suppressing heat input while forming the flange portion 31.

[0091] Implementation Method 6

[0092] like Figure 6 As shown, the second member 20 has a through portion 21 that opens at a position corresponding to the recess 11 of the first member 10. The inner diameter of the through portion 21 is smaller than the opening width of the recess 11.

[0093] The third component 30 is fused by arc welding. The third component 30 has a first joint 35 welded to the first component 10 and a second joint 36 welded to the first joint 35 to form a flange 31.

[0094] Specifically, when the molten third component 30 is welded to the first component 10 via the through portion 21, a short-circuit arc welding with a small arc extension of the arc 5 is performed with the heat input required for the penetration depth to form a first joint portion 35. The first joint portion 35 has a protrusion portion 32. The protrusion portion 32 is formed by the molten third component 30 extending radially outward from the inside of the recess 11 than the through portion 21.

[0095] Subsequently, in both positive polarity DC welding and polarity-switched AC welding, pulse welding based on alternating peak current and base current pulse waveforms is performed. This allows for low heat input without melting the second component 20, resulting in a larger arc 5 expansion and increased heat input to the solder side, which serves as the welding electrode, thereby increasing the amount of fusion. In pulse welding, droplets generated at the tip of the solder detach from the solder and transfer towards the flange 31 and the second component 20 side, at a ratio of one pulse consisting of the peak current and the base current.

[0096] Here, positive polarity-based DC welding refers to a DC welding process in which the solder, serving as the welding electrode, is set to the negative electrode side (negative), and the first component 10 and the second component 20, serving as the base material, are set to the positive electrode side (positive), thereby increasing the heat input to the solder serving as the welding electrode for welding. As a result, the heat input to the base material is suppressed, promoting the melting of the solder serving as the welding electrode.

[0097] Furthermore, AC welding based on switching polarity refers to an AC welding process in which, for example, the peak current is set to the negative side and the base current is set to the positive side. This results in the solder, serving as the welding electrode, being set to the negative side, while the first component 10 and the second component 20, serving as the base material, are set to the positive side. This increases the heat input to the solder serving as the welding electrode during peak current welding. Consequently, the heat input to the base material is suppressed, promoting the melting of the solder serving as the welding electrode.

[0098] It should be noted that, although the method is designed to perform pulse welding based on positive polarity, as a welding method that minimizes the extension of the arc 5 and suppresses heat input to the second component 20, short-circuit arc welding with repeated arc state and short-circuit state can also be performed.

[0099] During the process of the molten third component 30 forming a weld bead, a first joint 35 and a second joint 36 are provided on the third component 30. The first joint 35 is fused to the first component 10 inside the recess 11. The second joint 36 is fused to the first joint 35, thus forming the peripheral flange 31 of the pressing through portion 21.

[0100] The upper part of the first joint 35 is preferably welded in a shape with a central depression. This makes it easier to determine the welding position when welding the second joint 36 to the first joint 35. In addition, the molten second joint 36 tends to gather towards the central depression of the first joint 35, making the shape of the second joint 36 more regular.

[0101] Furthermore, the third component 30 solidifies and shrinks relative to the first component 10, thereby compressing and fixing the second component 20, which is a dissimilar material, between the flange portion 31 and the first component 10.

[0102] As described above, according to the joining structure of this embodiment, by dividing the third member 30 into a first joining portion 35 and a second joining portion 36, it is possible to flexibly apply welding methods or welding conditions that take into account the material properties of the second member 20.

[0103] Implementation Method 7

[0104] like Figure 7 As shown, the second member 20 has a surface on the side opposite to the first member 10 (in... Figure 7 The stepped portion 25 (with the upper surface in the middle) has an opening, and a through portion 21 is formed on the bottom surface of the stepped portion 25. The inner diameter of the through portion 21 is smaller than the opening width of the recessed portion 11.

[0105] The third component 30 is fused by arc welding. The third component 30 has a first joint 35 welded to the first component 10 and a second joint 36 welded to the first joint 35 to form a flange 31.

[0106] The first joint 35 is fused to the first member 10. Inside the recess 11, the molten third member 30 extends radially outward beyond the through portion 21. The first joint 35 has a protrusion 32 welded to the first member 10.

[0107] The second joint 36 is fused to the first joint 35. The second joint 36 flows out toward the peripheral portion of the upper surface side of the through portion 21, i.e., the bottom surface of the stepped portion 25, and extends in a flange shape. The second joint 36 has a flange portion 31 that presses against the peripheral portion of the through portion 21.

[0108] During the process of the molten third component 30 forming a weld bead, a first joint 35 and a second joint 36 are provided on the third component 30. The first joint 35 is fused to the first component 10 inside the recess 11. The second joint 36 is fused to the first joint 35, forming the flange 31 of the peripheral portion of the pressing through portion 21.

[0109] Furthermore, the third component 30 solidifies and shrinks relative to the first component 10, thereby compressing and fixing the second component 20, which is a dissimilar material, between the flange portion 31 and the first component 10.

[0110] As described above, according to the joining structure of this embodiment, the flange portion 31 of the third member 30 is disposed within the step portion 25, thereby preventing the flange portion 31 from protruding from the second member 20.

[0111] Implementation Method 8

[0112] like Figure 8 As shown, the first member 10 has a recess 11 formed with a depth that does not penetrate in the thickness direction. The recess 11 is formed on the overlapping surface of the first member 10 and the second member 20. Figure 8 In the example shown, the recess 11 is formed by a circular recess that opens upwards.

[0113] The second member 20 has a recess 11 and a through portion 21 formed with a depth that does not extend through in the thickness direction. The recess 11 is formed on the overlapping surface of the first member 10 and the second member 20. Figure 8 In the example shown, the recess 11 is formed by a circular recess that opens downwards. The recess 11 of the first member 10 and the recess 11 of the second member 20 are formed with the same opening width.

[0114] The through portion 21 opens at a position corresponding to the recess 11 of the first member 10 and the second member 20. The inner diameter of the through portion 21 is smaller than the opening width of the recess 11.

[0115] The third component 30 is fused together by arc welding. The molten third component 30 is fused together with the first component 10. Inside the recess 11, the molten third component 30 extends radially outward compared to the through portion 21.

[0116] Furthermore, after the molten third component 30 fills the through portion 21, it flows out toward the periphery of the upper surface side of the through portion 21 and expands in a flange shape.

[0117] During the process of forming a weld bead in the molten third component 30, a flange portion 31 and a protrusion portion 32 are provided on the third component 30. The flange portion 31 presses against the periphery of the through portion 21. The protrusion portion 32 extends radially outward from the recess 11 of the first component 10 and the second component 20. The protrusion portion 32 is welded to the first component 10.

[0118] Furthermore, the third component 30 solidifies and shrinks relative to the first component 10, thereby compressing and fixing the second component 20, which is a dissimilar material, between the flange portion 31 and the first component 10.

[0119] As described above, according to the joining structure of this embodiment, a recess 11 is provided in the first member 10 and the second member 20, and the molten third member 30 is extended inside the recess 11, thereby increasing the joining area of ​​the third member 30.

[0120] It should be noted that if the thickness of the first component 10 is so thin that it is difficult to form a recess 11 in the first component 10, the recess 11 may be provided only in the second component 20.

[0121] Implementation Method 9

[0122] like Figure 9 As shown, the first member 10 has a recess 11 formed to a depth that does not extend through the thickness direction. The recess 11 has a curved portion 12 that bends toward the bottom of the recess 11.

[0123] The second member 20 has a through portion 21 that opens at a position corresponding to the recess 11 of the first member 10. The inner diameter of the through portion 21 is smaller than the opening width of the recess 11.

[0124] The third component 30 is fused by arc welding. The molten third component 30 flows along the bend 12 of the recess 11 and is fused to the first component 10. Inside the recess 11, the molten third component 30 extends radially outward than the through portion 21.

[0125] In this embodiment, the first member 10 has an inner peripheral surface 11a that defines the recessed portion 11 formed on the overlapping surface of the first member 10 and the second member 20, and defines the area of ​​the recessed portion 11 in contact with the overlapping surface of the first member 10 and the second member 20, and a bottom surface 11b (inner surface of the curved portion) that defines the bottom side of the recessed portion 11. It should be noted that when the inner peripheral surface 11a and the bottom surface 11b defining the recessed portion 11 form a curved curve, the inner peripheral surface 11a and the bottom surface 11b can be represented by a single surface, or the inner peripheral surface 11a and the bottom surface 11b can be combined to form the inner peripheral surface 11a to define the recessed portion 11. Specifically, the area of ​​the recessed portion 11 in contact with the overlapping surface of the first member 10 and the second member 20 is defined by the boundary where the recessed portion 11 contacts the overlapping surface of the first member 10 and the second member 20. The protrusion 32 is located within the recessed portion 11. The gap 11c is formed between the protrusion 32 and the inner peripheral surface 11a.

[0126] Furthermore, the molten third component 30 fills the through portion 21, thereby extending in a flange shape on the upper surface of the second component 20.

[0127] During the process of forming a weld bead in the molten third component 30, a flange portion 31 and a protrusion portion 32 are provided on the third component 30. The flange portion 31 presses against the tapered portion 22 of the through portion 21. The protrusion portion 32 extends radially outward from the recess 11 of the first component 10. The protrusion portion 32 is welded to the first component 10.

[0128] Furthermore, the third component 30 solidifies and shrinks relative to the first component 10, thereby compressing and fixing the second component 20, which is a dissimilar material, between the flange portion 31 and the first component 10.

[0129] As described above, according to the joining structure of this embodiment, by providing a curved portion 12 in the recessed portion 11, the joining area of ​​the third member 30 can be increased compared to the case where the bottom of the recessed portion 11 is a flat surface.

[0130] Implementation Method 10

[0131] like Figure 10 as well as Figure 11 As shown, the first member 10 has a recess 11 formed to a depth that does not extend through the thickness direction. The recess 11 has an inclined portion 13 that slopes toward the bottom of the recess 11.

[0132] The second member 20 has a through portion 21 that opens at a position corresponding to the recess 11 of the first member 10. The inner diameter of the through portion 21 is smaller than the opening width of the recess 11.

[0133] The third component 30 is fused by arc welding. The molten third component 30 flows along the inclined portion 13 of the recess 11 and is fused to the first component 10. Inside the recess 11, the molten third component 30 extends radially outward than the through portion 21.

[0134] In this embodiment, the first member 10 has an inner peripheral surface 11a that defines the recess 11 and serves as the inner surface of the inclined portion, defining the area of ​​the recess 11 that contacts the overlapping surfaces of the first member 10 and the second member 20, and a bottom surface 11b that defines the bottom surface of the recess 11. It should be noted that when the inner peripheral surface 11a and the bottom surface 11b defining the recess 11 are composed of continuously inclined surfaces with a predetermined angle, either the inner peripheral surface 11a and the bottom surface 11b can be represented by a single inclined surface, or the inner peripheral surface 11a and the bottom surface 11b can be combined and used as the inner peripheral surface 11a to define the recess 11. Specifically, the area of ​​the recess 11 that contacts the overlapping surfaces of the first member 10 and the second member 20 is defined by the boundary where the recess 11 contacts the overlapping surfaces of the first member 10 and the second member 20. The protrusion 32 is located within the recess 11. The gap 11c is formed between the protrusion 32 and the inner peripheral surface 11a.

[0135] Furthermore, the molten third component 30 fills the through portion 21, thereby extending in a flange shape on the upper surface of the second component 20.

[0136] During the process of forming a weld bead in the molten third component 30, a flange portion 31 and a protrusion portion 32 are provided on the third component 30. The flange portion 31 presses against the tapered portion 22 of the through portion 21. The protrusion portion 32 extends radially outward from the recess 11 of the first component 10. The protrusion portion 32 is welded to the first component 10.

[0137] Furthermore, the third component 30 solidifies and shrinks relative to the first component 10, thereby compressing and fixing the second component 20, which is a dissimilar material, between the flange portion 31 and the first component 10.

[0138] As described above, according to the joining structure of this embodiment, by providing an inclined portion 13 in the recessed portion 11, the joining area of ​​the third member 30 can be increased compared to the case where the bottom of the recessed portion 11 is a flat surface.

[0139] Implementation Method 11

[0140] like Figure 12 as well as Figure 13 As shown, the first member 10 has a recess 11 formed with a depth that does not extend through the thickness direction. The recess 11 has a first recess 14 that opens upward and a plurality of second recesses 15 formed at the bottom of the first recess 14. The second recesses 15 are formed in a cone shape that tapers downward at the front end.

[0141] The second member 20 has a through portion 21 that opens at a position corresponding to the recess 11 of the first member 10. The inner diameter of the through portion 21 is smaller than the opening width of the recess 11.

[0142] The third component 30 is molten by arc welding. The molten third component 30 flows toward the bottom of the first recess 14 and disperses into the plurality of second recesses 15, where it is moltenly bonded to the first component 10. Inside the recess 11, the molten third component 30 extends radially outward than the through portion 21.

[0143] Furthermore, the molten third component 30 fills the through portion 21, thereby extending in a flange shape on the upper surface of the second component 20.

[0144] During the process of forming a weld bead in the molten third component 30, a flange portion 31 and a protrusion portion 32 are provided on the third component 30. The flange portion 31 presses against the tapered portion 22 of the through portion 21. The protrusion portion 32 extends radially outward from the recess 11 of the first component 10. The protrusion portion 32 is welded to the first component 10.

[0145] Furthermore, the third component 30 solidifies and shrinks relative to the first component 10, thereby compressing and fixing the second component 20, which is a dissimilar material, between the flange portion 31 and the first component 10.

[0146] As described above, according to the joining structure of this embodiment, by providing a plurality of second recesses 15 at the bottom of the first recess 14, the joining area of ​​the third member 30 can be increased compared to the case where the bottom of the first recess 14 is a flat surface.

[0147] Other Implementation Methods

[0148] The implementation method described above can also be configured as follows.

[0149] In this embodiment, the first component 10 is subjected to arc welding, but the method is not limited to this. Specifically, the solder used as the third component 30 includes both molten electrode type (consumable electrode type) and non-molten electrode type (non-consumable electrode type). Therefore, for example, instead of the welding wire used as the molten electrode type (consumable electrode type) solder used as the third component 30, laser filler welding can be performed on the first component 10 using a filler wire that is a non-molten electrode type (non-consumable electrode type) solder.

[0150] In laser filler welding, after the first component 10 is irradiated with a laser and sufficient penetration depth on its surface is ensured, the laser is irradiated only on the supplied filler wire, causing the third component 30, i.e., the filler wire, to melt. This allows for the suppression of heat input to the second component 20 while simultaneously filling the through portion 21 with the third component 30.

[0151] Furthermore, by defocusing the laser to reduce its energy density and ensuring a larger beam diameter, the outer periphery of the laser beam diameter can be used to preheat the second component 20. This allows the third component 30, i.e., the molten filler wire, to easily fuse with the second component 20.

[0152] Furthermore, the combination of the shape of the recessed portion 11 of the first member 10 and the shape of the through portion 21 of the second member 20 described in this embodiment is ultimately one example, but other combinations are also possible.

[0153] Industrial applicability

[0154] As explained above, the present invention achieves a highly practical effect by increasing the bonding area of ​​the solder and ensuring bonding strength, and is therefore extremely useful and industrially applicable.

[0155] Explanation of reference numerals in the attached figures

[0156] 10 First Component

[0157] 11. Depression

[0158] 12. Bend

[0159] 13 Inclined section

[0160] 14 First Depression

[0161] 15 Second Depression

[0162] 20 Second component

[0163] 21. Through Section

[0164] 30 Third component

[0165] 32. Protrusion.

Claims

1. A joining structure comprising a first member made of a metallic material, a second member made of a dissimilar material that is difficult to weld relative to the first member, and a third member made of solder welded to the first member, joined together. The joining structure is characterized in that... At least one of the first component and the second component has a recess formed on the overlapping surface of the first component and the second component. The second component has a through portion that opens at a position corresponding to the recess and has an inner diameter smaller than the opening width of the recess. The third component has a protrusion welded to the first component via the through portion and extending radially outward from inside the recessed portion. The second component is compressed and fixed between the first component and the third component by the solidification shrinkage of the third component relative to the first component.

2. The joining structure according to claim 1, characterized in that, The recess is formed in the first component.

3. The joining structure according to claim 1 or 2, characterized in that, The recess is formed in the second member.

4. The joining structure according to claim 1 or 2, characterized in that, The recessed portion has a curved portion that bends toward the bottom of the recessed portion.

5. The joining structure according to claim 1 or 2, characterized in that, The recessed portion has an inclined portion that slopes toward the bottom of the recessed portion.

6. The joining structure according to claim 1 or 2, characterized in that, The recessed portion has a first recessed portion and a second recessed portion formed at the bottom of the first recessed portion.

7. The joining structure according to claim 1 or 2, characterized in that, The third component is a metallic material of the same type as the first component.

8. The joining structure according to claim 1 or 2, characterized in that, At least one of the first component and the second component has an inner peripheral surface and a bottom surface defining the recess. The protruding part is located within the recessed part. A gap is formed between the protrusion and the inner circumferential surface.

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