Joint structure

Abstract

The second component (20) is made of a material that is difficult to weld to the first component (10). The third component (30) is welded to the first component (10) via a through-hole (21) in the second component (20). The fourth component (40) is made of a filler material that can be welded to the second component (20). The fourth component (40) covers the surface of the third component (30) and is welded to the second component (20).

Description

Technical Field

[0001] This invention relates to a joining structure. Background Technology

[0002] Patent document 1 discloses a joining structure in which a filler material (welding wire) is arc welded through a through-hole in a dissimilar material that is difficult to weld onto the first metal material while the first metal material is stacked together.

[0003] At this point, a flange portion is formed by using molten filler material to cover the outer periphery of the upper surface of the through-hole of the dissimilar material. In this way, the filler material solidifies and shrinks relative to the first metal material, thereby generating a compressive fixing force between the flange portion and the first metal material. Under the action of this compressive fixing force, the dissimilar material and the first metal material are fixed together.

[0004] Patent Document 1: International Publication No. 2018 / 030272 Summary of the Invention

[0005] -The technical problem the invention aims to solve-

[0006] In the invention of Patent Document 1, moisture may penetrate from the outside through the gap between the flange portion of the third metal material and the overlapping surface of the second metal material. Moreover, due to the infiltrated moisture, electro-corrosion may occur at the overlapping portion of the flange portion of the third metal material and the second metal material, which may lead to a decrease in the bonding strength.

[0007] This invention was made to solve the above-mentioned technical problems, and its purpose is to suppress electro-corrosion in the part where metal materials and dissimilar materials are superimposed.

[0008] -Technical solutions for solving technical problems-

[0009] This disclosure relates to a joining structure in which a first component made of a metallic material, a second component made of a material that is difficult to weld to the first component, and a third component made of a filler material that is welded to the first component are joined together. The technical solution adopted in this disclosure is as follows.

[0010] That is, in the first aspect, a through portion is formed on the second component that extends through the first component, and the third component is welded to the first component via the through portion. The joining structure includes a fourth component made of a filler material that can be welded to the second component, and covers the surface of the third component and is welded to the second component.

[0011] In the first aspect, the third component is welded to the first component via a through portion. The fourth component is made of a filler material capable of being welded to the second component. The fourth component covers the surface of the third component and is welded to the second component.

[0012] In this way, by covering the surface of the third component with the fourth component and welding the fourth component to the second component, the gap between the second and third components is blocked by the fourth component, thereby preventing moisture from entering the overlapping part of the second and third components from the outside.

[0013] This helps to suppress electro-corrosion at the point where the second and third components overlap, thereby ensuring the strength of the bond.

[0014] The second aspect, based on the first aspect, is that the third component has a flange portion that protrudes radially outward from the through portion on the surface of the second component opposite to the first component, and presses against the periphery of the through portion.

[0015] In the second aspect, by pressing the side of the second component opposite to the first component with the flange portion, the second component can be compressed and fixed between the flange portion and the first component.

[0016] This ensures that the overlapping parts of the second and third components are tightly attached, making it difficult for moisture to penetrate from the outside.

[0017] The third aspect, based on the first aspect, is that the through portion has a tapered portion that tapers toward the first component, and the third component presses the tapered portion.

[0018] In the third aspect, by providing a tapered portion in the through-hole and solidifying the third component into a shape extending along the tapered portion, the thickness of the third component protruding from the second component can be suppressed. In this way, the thickness of the fourth component protruding from the second component can also be suppressed.

[0019] Fourthly, based on the first aspect, the second component has a stepped portion and the through portion, the stepped portion opening on a side opposite to the first component, and the through portion forming on the bottom surface of the stepped portion.

[0020] In the fourth aspect, a through portion is formed on the bottom surface of the stepped portion of the second component. This allows the third component to be arranged within the stepped portion, thereby preventing the third component from protruding from the second component. Furthermore, it helps to reduce the thickness of the fourth component protruding from the second component.

[0021] The fifth aspect is based on the fourth aspect, wherein the bottom surface of the stepped portion is inclined toward the through portion.

[0022] In the fifth aspect, by tilting the bottom surface of the stepped portion toward the through portion, the filling material of the molten third component can easily flow toward the central side of the through portion.

[0023] The sixth aspect, based on the first aspect, is that the second component has a stepped portion and the through portion, the stepped portion having an opening on the overlapping surface where it overlaps with the first component, the through portion being formed on the bottom surface of the stepped portion, and the first component having a bulge portion that bulges toward the stepped portion.

[0024] In the sixth aspect, the bulge of the first component bulges toward the step of the second component. In this way, when the second component is stacked with the first component, the first component and the second component can be easily aligned simply by fitting the step with the bulge.

[0025] The seventh aspect, based on any one of the first to sixth aspects, wherein the third component has a first joint and a second joint, the first joint being welded to the first component, the second joint being welded to the first joint, and pressing the periphery of the through portion.

[0026] In the seventh aspect, by forming the third component from separate first and second joints, it is possible to take into account the material properties of the second component and to appropriately use welding methods or welding conditions.

[0027] For example, when welding the molten filler material of the third component to the first component through the through-hole, a short-circuit arc welding process with a small arc extension, involving repeated short-circuit and arc states, can be performed to form the first joint. Then, a second joint can be formed by performing pulse welding with positive polarity and alternating current, using a low heat input that will not melt the second component. This allows for the formation of the second joint while suppressing the amount of heat input to the second component.

[0028] Based on any one of the first to seventh aspects, the fourth component has a central portion and an outer peripheral portion, the central portion covering the central portion of the surface of the third component, and the outer peripheral portion being welded to the central portion and the second component along the outer peripheral edge of the central portion.

[0029] In the eighth aspect, the fourth component is formed by separate central and peripheral portions. For example, the central portion is formed by arc welding, covering the central part of the surface of the third component, and then arc welding is performed along the outer periphery of the central portion to form the peripheral portion, thereby fusing the central and peripheral portions together.

[0030] Alternatively, an outer periphery can be formed by arc welding, covering the outer periphery of the surface of the third component. Then, arc welding is performed on the central part of the surface of the third component to form a central part, and the central part is fused with the outer periphery.

[0031] -The Effects of the Invention-

[0032] According to various aspects of this disclosure, it is possible to suppress electro-corrosion in the portion where metallic materials and dissimilar materials are superimposed. Attached Figure Description

[0033] Figure 1 This is a side sectional view used to illustrate the joining structure involved in this first embodiment;

[0034] Figure 2 This is a side sectional view used to illustrate the joining structure involved in this second embodiment;

[0035] Figure 3 This is a side sectional view used to illustrate the joining structure involved in this third embodiment;

[0036] Figure 4 This is a side sectional view used to illustrate the joining structure involved in this fourth embodiment;

[0037] Figure 5 This is a side sectional view used to illustrate the joining structure involved in this fifth embodiment;

[0038] Figure 6 This is a side sectional view used to illustrate the joining structure involved in this sixth embodiment;

[0039] Figure 7 This is a side sectional view used to illustrate the joining structure involved in this seventh embodiment;

[0040] Figure 8 This is a side sectional view used to illustrate the joining structure involved in this eighth embodiment. Detailed Implementation

[0041] 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 present invention, its application, or its uses.

[0042] (First Implementation)

[0043] Figure 1 A joining structure is shown for joining a first component 10 made of a metallic material, a second component 20 made of a material that is difficult to weld to the first component 10, and a third component 30 made of a first filler material as a filler material to each other.

[0044] The first component 10 is a plate-shaped component made of metal.

[0045] The second component 20 is a plate-shaped component made of a material that is difficult to weld to the first component 10. The second component 20 is stacked on top of the first component 10. The second component 20 has a circular through-hole 21.

[0046] It should be noted that in this embodiment, the through-hole 21 is described as a circular through hole, but the through-hole 21 may also be an elliptical or elongated through hole.

[0047] The third component 30 is made of a filler material, which is a metallic material of the same type as the first component 10. Here, "metallic material of the same type" refers to metals that can be welded together. This includes not only metals of the same material but also metals that are ferrous or non-ferrous metals, etc., with good weldability. In other words, "metallic material of the same type" refers to the same kind of material with good weld compatibility.

[0048] Specifically, the combinations of the first component 10 and the third component 30 during welding can be listed as follows: Combinations of ferrous metal materials, such as low-carbon steel and low-carbon steel, stainless steel and stainless steel, low-carbon steel and high-tensile steel (high-strength steel), high-tensile steel and high-tensile steel, etc. Combinations of non-ferrous metal materials, such as aluminum and aluminum, aluminum and aluminum alloys, aluminum alloys and aluminum alloys, etc.

[0049] The second component 20, being a dissimilar material, is made of a material different from the first component 10 and the third component 30, which are made of the same type of metal, and is a material that is difficult to weld onto the first component 10 and the third component 30.

[0050] For example, if the first component 10 and the third component 30 are made of the same type of metal material, the second component 20, which is made of a different type of material, is made of a non-ferrous metal material such as copper or aluminum.

[0051] The third component 30 is welded to the first component 10 via the through portion 21. A flange portion 31 is provided on the third component 30, which presses against the periphery of the through portion 21. 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.

[0052] In the portion where the flange 31 of the third component 30 overlaps with the second component 20, electro-corrosion may occur due to the intrusion of moisture from the outside.

[0053] Therefore, in this embodiment, the fourth component 40 is used to block the gap between the overlapping portion of the second component 20 and the third component 30.

[0054] Specifically, the fourth component 40 is made of a second filler material, which is a metal of the same type that can be welded to the second component 20. The fourth component 40 covers the surface of the third component 30. The fourth component 40 is welded to the second component 20.

[0055] It should be noted that in the following description, the following cases are explained: the first component 10 is made of low-carbon steel, the second component 20 is made of aluminum, the third component 30, which is the filler material for the first component 10, is made of low-carbon steel, and the fourth component 40, which is the filler material for the second component 20, is made of aluminum.

[0056] The arc welding machine 1 includes a nozzle 2 and a contact tip 3. The nozzle 2 supplies shielding gas, etc., to the welding area of ​​the object being welded. The contact tip 3 supplies welding current to the third component 30.

[0057] The arc welding machine 1 generates an arc 5 by supplying welding current to the first component 10 while conveying the third component 30 through the through-hole 21. The third component 30, which is molten by arc welding, is fused with the first component 10 and stacked within the through-hole 21. Furthermore, after filling the through-hole 21, the molten third component 30 flows out to the peripheral portion on the upper surface side of the through-hole 21 and expands into a flange shape.

[0058] During the process of the third component 30 becoming a weld after melting, a flange 31 is provided on the third component 30, which presses against the periphery of the through portion 21. The flange 31 is located on the side of the second component 20 opposite to the first component 10. Figure 1 The upper surface (the middle part) protrudes radially outward from the through part 21.

[0059] Then, 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 31 and the first component 10.

[0060] As described above, by melting the welding wire, which serves as the third component 30 and the filler material, and supplying it to the first component 10 through the through-hole 21 of the second component 20, a weld seam in the shape of a flange for ensuring strength can be formed on the second component 20, and the second component 20 can be clamped by compression fixation.

[0061] It should be noted that the second component 20 and the third component 30 do not need to be fused together. Even if an intermetallic compound is formed by fusion bonding, it is for the purpose of using the flange shape for compression and fixation, so there is no problem.

[0062] The arc welding machine 1 covers the surface of the third component 30 with filler material (fourth component 40) that can be welded to the second component 20, and welds it to the second component 20. Specifically, when welding the filler material to the second component 20, the arc welding machine 1 performs pulse welding using a pulse waveform with alternating peak current and base current, in addition to DC welding with positive polarity and AC welding with switching polarity. In pulse welding, the arc 5 can be expanded with a low heat input that does not melt the second component 20, increasing the heat input to the filler material side, which serves as the welding electrode, thereby increasing the amount of fusion.

[0063] In pulse welding, a pulse consisting of a peak current and a base current is applied once to cause the molten droplet generated at the top of the filler material to detach from the filler material and transition to the flange 31 and the second component 20 side.

[0064] Here, positive polarity DC welding refers to welding using direct current by making the filler material, which serves as the welding electrode, the negative electrode side (negative pole) and the first component 10 and the second component 20, which serve as the base material, the positive electrode side (positive pole), thereby increasing the heat input to the filler material, which serves as the welding electrode, during welding. In this way, the heat input to the base material can be suppressed, and the melting of the filler material, which serves as the welding electrode, can be promoted.

[0065] Furthermore, in AC welding using alternating current with reverse polarity switching, for example, the peak current waveform is made to be the positive side with reverse polarity, and the base current waveform is made to be the negative side with positive polarity. In the case of the reverse polarity peak current, the first component 10 and the second component 20, serving as the base material, are on the negative side, and the filler material, serving as the welding electrode, is on the positive side. In the case of the positive polarity base current, the first component 10 and the second component 20, serving as the base material, are on the positive side, and the filler material, serving as the welding electrode, is on the negative side.

[0066] As described above, alternating current welding with switching polarity refers to welding by increasing the heat input to the first component 10 and the second component 20, which serve as the base material, during the peak current of the reverse polarity, and by increasing the heat input to the filler material, which serves as the welding electrode, during the base current of the positive polarity. In this way, the heat input to the base material can be suppressed compared to direct current welding, and the melting of the filler material, which serves as the welding electrode, can be promoted.

[0067] It should be noted that although pulse welding utilizing positive polarity is adopted, as a welding method that minimizes the expansion of arc 5 but suppresses heat input to the second component 20, short-circuit arc welding that repeatedly alternates between arc and short-circuit states can also be implemented.

[0068] The arc welding machine 1 generates an arc 5 by supplying welding current while feeding filler material (fourth component 40) onto the surface of the third component 30. The fourth component 40, which is molten by arc welding, is fused together with the second component 20 and overlaps the surface of the third component 30.

[0069] In summary, in the joining structure of this embodiment, by covering the surface of the third component 30 with the fourth component 40 and welding the fourth component 40 to the second component 20, the fourth component 40 blocks the gap between the second component 20 and the third component 30, thereby preventing moisture from entering from the outside. In this way, it is possible to suppress moisture from entering the overlapping portion of the second component 20 and the third component 30.

[0070] In this way, electro-corrosion can be suppressed at the point where the second component 20 and the third component 30 overlap, thereby ensuring the bonding strength.

[0071] As described above, a second welding is performed using a second filler material (fourth component 40) that is the same as the second component 20 but different from the third component 30, and the welding is performed by covering the weld with molten metal in a flange shape formed by the third component 30, forming a weld larger than the flange shape size. In this way, fusion bonding can be performed using the fourth component 40 that is the same as the second component 20.

[0072] In addition, by fusing the same materials together, it is possible to inhibit the intrusion of moisture from the outside without using commonly used adhesives, sealants, or sealing agents, thereby inhibiting electro-corrosion.

[0073] It should be noted that, basically, the first component 10 and the third component 30 are made of materials with higher melting points than the second component 20 and the fourth component 40. As a result, the interface between the third component 30 and the fourth component 40 is either not fused together or only slightly fused together.

[0074] In this way, even if the weld of the fourth component 40 is formed on the weld of the flange shape of the third component 30, the weld of the fourth component 40 can be formed without causing the flange shape of the third component 30 to be deformed.

[0075] (Second Implementation)

[0076] Hereinafter, the same symbols will be used to mark the parts that are the same as those in the first embodiment described above, and only the differences will be explained.

[0077] like Figure 2 As shown, the second component 20 has a through portion 21. The through portion 21 has a tapered portion 22 that tapers toward the first component 10.

[0078] 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, concentrates towards the central side of the through portion 21, and fuses with the first component 10.

[0079] Then, the molten third component 30 fills the through portion 21, thereby expanding into a flange shape on the upper surface of the tapered portion 22.

[0080] During the process of the molten third component 30 becoming a weld, a flange 31 is provided on the third component 30, which presses against the tapered portion 22 of the through portion 21.

[0081] Then, 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 31 and the first component 10.

[0082] Then, an electric arc 5 is generated by supplying welding current to the surface of the third component 30 while conveying the fourth component 40. The fourth component 40, which is molten by arc welding, is fused together with the second component 20 and overlaps the surface of the third component 30.

[0083] As described above, according to the joining structure of this embodiment, by providing a tapered portion 22 in the through portion 21 and solidifying the flange portion 31 into a shape extending along the tapered portion 22, the thickness of the flange portion 31 protruding from the second component 20 can be suppressed. In this way, the thickness of the fourth component 40 protruding from the second component 20 can also be suppressed.

[0084] (Third Implementation)

[0085] like Figure 3 As shown, the second component 20 has a stepped portion 25 and a through portion 21, the stepped portion 25 being on the side opposite to the first component 10. Figure 3 The upper surface is open, and the through portion 21 is formed on the bottom surface of the stepped portion 25.

[0086] The third component 30 is fused together by arc welding. The molten third component 30 is then fused together with the first component 10.

[0087] Furthermore, after the molten third component 30 fills the through portion 21, it flows out to the periphery of the upper surface side of the through portion 21, that is, the bottom surface of the step portion 25, and expands into a flange shape.

[0088] During the process of the molten third component 30 becoming a bead, a flange 31 is provided on the third component 30, which presses against the periphery of the through portion 21.

[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] Subsequently, an electric arc 5 is generated by supplying welding current to the surface of the third component 30 while conveying the fourth component 40. The fourth component 40, which is molten by arc welding, is fused together with the step portion 25 of the second component 20 and overlaps the surface of the third component 30.

[0091] As described above, according to the joining structure of this embodiment, the flange portion 31 of the third component 30 can be arranged within the stepped portion 25, thereby suppressing the flange portion 31 from protruding from the second component 20. Furthermore, the thickness of the fourth component 40 protruding from the second component 20 can be suppressed.

[0092] (Fourth Implementation)

[0093] like Figure 4 As shown, the second component 20 has a stepped portion 25 and a through portion 21, the stepped portion 25 being on the side opposite to the first component 10. Figure 4 The upper surface of the stepped portion 25 has an opening, and the 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.

[0094] The third component 30 is fused together by arc welding. The molten third component 30 is fused together with the first component 10. In addition, when the molten third component 30 contacts 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.

[0095] Furthermore, after the molten third component 30 fills the through portion 21, it flows out to the periphery of the upper surface side of the through portion 21, that is, the bottom surface of the step portion 25, and expands into a flange shape on the inclined surface of the step portion 25.

[0096] During the process of the molten third component 30 becoming a weld, a flange 31 is provided on the third component 30, which presses against the inclined surface of the step portion 25.

[0097] 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.

[0098] Subsequently, an electric arc 5 is generated by supplying welding current while conveying the fourth component 40 to the surface of the third component 30. The fourth component 40, molten by arc welding, flows along the inclined surface of the step portion 25. More specifically, it flows effectively in a manner that blocks the gap between the third component 30 and the second component 20 from the outer side. Moreover, the molten fourth component 40 fuses with the second component 20 and overlaps and covers the surface of the third component 30.

[0099] As described above, according to the joining structure of this embodiment, by tilting the bottom surface of the step portion 25 toward the through portion 21, the molten third component 30 can easily flow to the through portion 21.

[0100] In addition, the molten fourth component 40 flows along the inclined surface of the step portion 25, thereby effectively blocking the gap between the third component 30 and the second component 20 from the outer side, and moltenly bonding with the second component 20.

[0101] Furthermore, the flange portion 31 of the third component 30 can be arranged within the stepped portion 25, thereby suppressing the flange portion 31 from protruding from the second component 20. Additionally, the thickness of the fourth component 40 protruding from the second component 20 can be suppressed.

[0102] (Fifth Implementation)

[0103] like Figure 5 As shown, the second component 20 has a stepped portion 25 and a through portion 21, the stepped portion being on the overlapping surface with the first component 10 ( Figure 5 The lower surface is open, and the through portion 21 is formed on the bottom surface of the stepped portion 25.

[0104] The first component 10 has a bulge 15 that bulges toward the step portion 25. The bulge 15 is embedded in the step portion 25.

[0105] The third component 30 is fused together by arc welding. The molten third component 30 is then fused together with the first component 10.

[0106] Furthermore, after the molten third component 30 fills the through-hole 21, it flows out to the periphery of the upper surface side of the through-hole 21 and expands into a flange shape.

[0107] During the process of the molten third component 30 becoming a bead, a flange 31 is provided on the third component 30, which presses against the periphery of the through portion 21.

[0108] 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.

[0109] Then, an electric arc 5 is generated by supplying welding current to the surface of the third component 30 while conveying the fourth component 40. The fourth component 40, which is molten by arc welding, is fused together with the second component 20 and overlaps the surface of the third component 30.

[0110] As described above, according to the joining structure involved in this embodiment, the alignment of the first component 10 and the second component 20 can be easily achieved by inserting the bulge 15 into the step portion 25 when the second component 20 is stacked on the first component 10.

[0111] Furthermore, when the third component 30 is melted relative to the first component 10 by arc welding, the space (space) vacated on the back side of the bulge 15 on the first component 10 allows for a fully penetrating weld bead to be formed on the side opposite to the second component 20, i.e., the back side of the first component 10. In this way, the strength can be further improved by so-called penetration welding, which forms the weld bead as if it were also welded from the back side of the first component 10.

[0112] Furthermore, by providing an open space on the back side of the bulge 15 of the first component 10, it is possible to ensure space when the weld bead protrudes from the back side of the first component 10 as a partial penetration weld bead.

[0113] (Sixth Implementation Method)

[0114] like Figure 6 As shown, the second component 20 has a through portion 21.

[0115] The third component 30 is fused by arc welding. The third component 30 has a first joint 35 and a second joint 36, the first joint 35 being welded to the first component 10, and the second joint 36 being welded to the first joint 35, forming a flange 31.

[0116] Specifically, when welding the molten third component 30 to the first component 10 via the through-hole 21, a short-circuit arc welding process with a small arc extension and repeated short-circuit and arc states is performed with the heat input required for melting to form the first joint 35. Then, a pulse welding process using positive polarity, alternating current, is performed with a low heat input that does not melt the second component 20 to form the second joint 36. In this way, the flange 31 can be formed while suppressing the amount of heat input to the second component 20.

[0117] During the process of the molten third component 30 becoming a weld, a first joint 35 and a second joint 36 are provided on the third component 30. The first joint 35 is fused together with the first component 10. The second joint 36 is fused together with the first joint 35 and forms a flange 31, which presses against the periphery of the through portion 21.

[0118] The upper part of the first joint 35 is preferably welded in a shape that forms a central depression.

[0119] In this way, when welding the second joint 36 to the first joint 35, the welding position is easy to determine. In addition, the molten second joint 36 is easily concentrated towards the central recess of the first joint 35, thereby enabling further adjustment of the shape of the second joint 36.

[0120] 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.

[0121] Then, an electric arc 5 is generated by supplying welding current to the surface of the third component 30 while conveying the fourth component 40. The fourth component 40, which is molten by arc welding, is fused together with the second component 20 and overlaps the surface of the third component 30.

[0122] As described above, according to the joining structure involved in this embodiment, the third component 30 is formed by separating the first joining portion 35 and the second joining portion 36, thereby taking into account the material properties of the second component 20 and appropriately using welding methods or welding conditions.

[0123] It should be noted that the shapes of the first component 10 and the second component 20 are only examples and can be combinations of other shapes.

[0124] (Seventh Implementation)

[0125] like Figure 7 As shown, the second component 20 has a through portion 21.

[0126] The third component 30 is fused together by arc welding. The molten third component 30 is fused together with the first component 10. After filling the through portion 21, the molten third component 30 flows out to the peripheral portion on the upper surface side of the through portion 21 and expands into a flange shape.

[0127] During the process of the molten third component 30 becoming a bead, a flange 31 is provided on the third component 30, which presses against the periphery of the through portion 21.

[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] The fourth component 40 has a central portion 41 and an outer peripheral portion 42. The central portion 41 covers the central part of the surface of the third component 30. The outer peripheral portion 42 is welded to the central portion 41 and the second component 20 along the outer peripheral edge of the central portion 41.

[0130] Specifically, an electric arc 5 is generated by supplying welding current to the central portion of the surface of the third component 30 while conveying the fourth component 40 to it. The fourth component 40, molten by the electric arc welding, is layered and covers the surface of the third component 30. In this way, the central portion 41 of the fourth component 40 is formed.

[0131] Furthermore, by rotating the nozzle 2 of the arc welding machine 1 along the outer periphery of the central portion 41, molten fourth component 40 is supplied to the outer periphery of the central portion 41. The molten fourth component 40 is welded to the central portion 41 and the second component 20. In this way, the outer periphery 42 of the fourth component 40 is formed.

[0132] As described above, according to the joining structure of this embodiment, the central portion 41 is formed by arc welding, covering the central portion of the surface of the third component 30, and then arc welding is performed along the outer periphery of the central portion 41 to form the outer peripheral portion 42, thereby enabling the central portion 41 and the outer peripheral portion 42 to be fused together.

[0133] (Eighth Implementation Method)

[0134] like Figure 8 As shown, the second component 20 has a through portion 21.

[0135] The third component 30 is fused together by arc welding. The molten third component 30 is fused together with the first component 10. After filling the through portion 21, the molten third component 30 flows out to the peripheral portion on the upper surface side of the through portion 21 and expands into a flange shape.

[0136] During the process of the molten third component 30 becoming a bead, a flange 31 is provided on the third component 30, which presses against the periphery of the through portion 21.

[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] The fourth component 40 has a central portion 41 and an outer peripheral portion 42. The central portion 41 covers the central part of the surface of the third component 30. The outer peripheral portion 42 is welded to the central portion 41 and the second component 20 along the outer peripheral edge of the central portion 41.

[0139] Specifically, by rotating the nozzle 2 of the arc welding machine 1 along the outer periphery of the flange portion 31, molten fourth component 40 is supplied to the outer periphery of the flange portion 31. The molten fourth component 40 is welded to the second component 20 along the outer periphery of the flange portion 31. In this way, the outer periphery 42 of the fourth component 40 is formed.

[0140] Furthermore, an electric arc 5 is generated by supplying welding current to the central portion of the surface of the third component 30 while conveying the fourth component 40. The fourth component 40, molten by arc welding, fuses with the outer peripheral portion 42 and overlaps the surface of the third component 30. In this way, the central portion 41 of the fourth component 40 is formed.

[0141] As described above, according to the joining structure of this embodiment, an outer peripheral portion 42 is formed by arc welding to cover the outer peripheral portion of the surface of the third component 30. Then, arc welding is performed on the central portion of the surface of the third component 30 to form a central portion 41, thereby enabling the central portion 41 to be fused with the outer peripheral portion 42.

[0142] (Other implementation methods)

[0143] The above implementation method can also adopt the following structure.

[0144] In this embodiment, arc welding is performed on the first component 10, but the method is not limited to this. Specifically, the filler material for the third component 30 includes both solvent-electrode (consumable electrode) and non-solubilized (non-consumable electrode) filler materials. Therefore, for example, a filler wire that is a non-solubilized (non-consumable electrode) filler material can be used instead of the filler wire that is a solvent-electrode (consumable electrode) filler material used for the third component 30 to perform laser filler welding on the first component 10.

[0145] In laser filler welding, after the surface of the first component 10 is melted by irradiating it with a laser, the laser is irradiated only onto the supplied filler wire, thereby melting the filler wire, which serves as the third component 30. In this way, the penetration portion 21 can be filled with the third component 30 while suppressing the heat input to the second component 20.

[0146] Furthermore, to reduce the power density of the laser, the laser beam diameter is ensured to be large by defocusing the laser, thereby allowing the outer periphery of the laser beam diameter to be used for preheating of the second component 20. This facilitates the fusion of the molten filler wire, which serves as the third component 30, with the second component 20. Moreover, this effect prevents moisture from entering the overlapping portion of the second and third components 20 by sealing the gap between them.

[0147] Alternatively, a hybrid welding method using arc welding and laser welding can be used to form the third component 30 and the fourth component 40. Specifically, a hybrid welding method can be used to form the third component 30 by laser filler welding and the fourth component 40 by arc welding.

[0148] Alternatively, it can be formed by hybrid welding, in which a third component 30 is formed by arc welding using a solution-type filler material and a fourth component 40 is formed by laser filler welding using a filler wire as a non-solution-type filler material.

[0149] Furthermore, the laser welding described above can be combined. For example, at least one of the following locations can be preheated by irradiating a reduced-output laser onto the outer periphery of the penetration 21 of the second component 20 and the upper part of the third component 30. The reduced output can be achieved by, for example, defocusing the laser to reduce its power density, or by changing the continuous output of the laser to a pulsed oscillation output and reducing the duty cycle (on / off ratio) of the pulsed oscillation output. This improves the fusion of the second component 20, the third component 30, and the fourth component 40 during welding. Consequently, it is possible to suppress the intrusion of moisture from the outside into the overlapping portion of the second component 20, the third component 30, and the fourth component 40.

[0150] -Industry Applicability-

[0151] In summary, the present invention can achieve a highly practical effect of suppressing electro-corrosion in the part where metal materials and dissimilar materials are superimposed, and is therefore extremely useful and has high industrial applicability.

[0152] -Symbol Explanation 1

[0153] 10 First Component

[0154] 15. Drum section

[0155] 20 Second Component

[0156] 21 Penetrating section

[0157] 22. Conical part

[0158] 25 Steps

[0159] 30 Third Component

[0160] 31 Flange portion

[0161] 35 First joint

[0162] 36 Second joint

[0163] 40 Fourth Component

[0164] 41. Central Department

[0165] 42 Peripheral part

Claims

1. A joining structure in which a first component made of a metallic material, a second component made of a material difficult to weld to the first component, and a third component made of a filler material welded to the first component are joined together, characterized in that: A through portion is formed on the second component, extending through the first component. The third component is welded to the first component via the through portion. The joining structure includes a fourth component made of a filler material that can be welded to the second component, and covers the surface of the third component and is welded to the second component.

2. The joining structure according to claim 1, characterized in that: The third component has a flange that protrudes radially outward from the through portion on the surface of the second component opposite to the first component, and presses against the periphery of the through portion.

3. The joining structure according to claim 1, characterized in that: The through portion has a tapered portion that tapers toward the first component. The third component presses down on the tapered portion.

4. The joining structure according to claim 1, characterized in that: The second component has a stepped portion and the through portion, the stepped portion having an opening on a side opposite to the first component, and the through portion being formed on the bottom surface of the stepped portion.

5. The joining structure according to claim 4, characterized in that: The bottom surface of the stepped portion is inclined toward the through portion.

6. The joining structure according to claim 1, characterized in that: The second component has a stepped portion and a through portion, the stepped portion having an opening on the overlapping surface where it overlaps with the first component, and the through portion being formed on the bottom surface of the stepped portion. The first component has a bulge that bulges toward the stepped portion.

7. The joining structure according to any one of claims 1 to 6, characterized in that: The third component has a first joint and a second joint, the first joint being welded to the first component, the second joint being welded to the first joint, and pressing the periphery of the through portion.

8. The joining structure according to any one of claims 1 to 6, characterized in that: The fourth component has a central portion and an outer peripheral portion. The central portion covers the central part of the surface of the third component, and the outer peripheral portion is welded to the central portion and the second component along the outer peripheral edge of the central portion.

Images