WO2022050161A1

WO2022050161A1 - Joint structure

Info

Publication number: WO2022050161A1
Application number: PCT/JP2021/031301
Authority: WO
Inventors: 潤司藤原; 龍幸中川
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2020-09-01
Filing date: 2021-08-26
Publication date: 2022-03-10
Also published as: CN116096522A; JPWO2022050161A1

Abstract

A second member 20 is composed of a material that is difficult to weld to a first member 10. A third member 30 is welded to the first member 10 through a perforation 21 in the second member 20. A fourth member 40 is composed of a filler material that can be welded to the second member 20. The fourth member 40 covers the surface of the third member 30 and is welded to the second member 20.

Description

Joined structure

The present invention relates to a bonded structure.

In Patent Document 1, a first metal material and a dissimilar material that is difficult to weld to the first metal material are superposed, and a fillering material (welding wire) is provided through a penetration portion of the dissimilar material. Is disclosed as a joint structure in which the metal is arc-welded.

At this time, the molten filler material forms a brim portion so as to cover the outer peripheral portion on the upper surface side of the penetrating portion of the dissimilar material. As a result, the dissimilar material and the first metal material are fixed by the compressive fixing force between the brim portion and the first metal material due to the solidification shrinkage of the filler material with respect to the first metal material.

International Publication No. 2018/0302722

By the way, in the invention of Patent Document 1, there is a possibility that moisture may enter from the outside through the gap between the brim portion of the third metal material and the overlapping surface of the second metal material. Then, due to the invading moisture, electrolytic corrosion may occur at the portion where the brim portion of the third metal material and the second metal material overlap, and the bonding strength may decrease.

The present invention has been made in view of this point, and an object thereof is to suppress galvanic corrosion at a portion where a metal material and a dissimilar material overlap.

Aspects of the present disclosure are a first member made of a metal material, a second member made of a material that is difficult to weld to the first member, and a first member welded to the first member. The following solutions were taken for the joint structure in which the third member made of the filler metal was joined to each other.

That is, in the first aspect, the second member is formed with a penetrating portion penetrating toward the first member.
The third member is welded to the first member via the penetration portion.
It is composed of a filler material that can be welded to the second member, covers the surface of the third member, and has a fourth member welded to the second member.

In the first aspect, the third member is welded to the first member via the penetration portion. The fourth member is composed of a filler material that can be welded to the second member. The fourth member covers the surface of the third member and is welded to the second member.

In this way, the surface of the third member is covered with the fourth member, the fourth member is welded to the second member, and the gap between the second member and the third member is formed in the fourth member. By closing with, it is possible to suppress the invasion of moisture from the outside into the overlapped portion of the second member and the third member.

As a result, it is possible to suppress the occurrence of electrolytic corrosion at the portion where the second member and the third member overlap, and to secure the joint strength.

The second aspect is, in the first aspect,
The third member has a flange portion on the surface of the second member opposite to the first member, which projects radially outward from the penetration portion and presses the peripheral edge portion of the penetration portion. ..

In the second aspect, the flange portion presses the surface of the second member opposite to the first member to compress and fix the second member between the flange portion and the first member. be able to.

As a result, the overlapped portion of the second member and the third member are brought into close contact with each other, and it becomes difficult for moisture to enter from the outside.

The third aspect is, in the first aspect,
The penetrating portion has a tapered portion that tapers toward the first member.
The third member holds down the tapered portion.

In the third aspect, the thickness of the third member protruding from the second member can be suppressed by providing the tapered portion in the penetrating portion and solidifying the third member in a shape along the tapered portion. Thereby, the thickness of the fourth member protruding from the second member can also be suppressed.

The fourth aspect is, in the first aspect,
The second member has a stepped portion that opens on a surface opposite to the first member, and the penetrating portion formed on the bottom surface of the stepped portion.

In the fourth aspect, a penetration portion is formed on the bottom surface of the stepped portion of the second member. As a result, the third member can be arranged in the step portion to prevent the third member from popping out from the second member. In addition, the thickness of the fourth member protruding from the second member can be suppressed.

The fifth aspect is the fourth aspect in the fourth aspect.
The bottom surface of the step portion is inclined toward the penetration portion.

In the fifth aspect, by inclining the bottom surface of the stepped portion toward the penetrating portion, the filler material of the melted third member can easily flow toward the center side of the penetrating portion.

The sixth aspect is the first aspect.
The second member has a stepped portion that opens in the overlapping surface with the first member, and the penetrating portion formed on the bottom surface of the stepped portion.
The first member has a bulging portion that bulges toward the stepped portion.

In the sixth aspect, the bulging portion of the first member bulges toward the stepped portion of the second member. As a result, when the second member is superposed on the first member, if the stepped portion is fitted to the bulging portion, the positioning of the first member and the second member can be easily performed. be able to.

The seventh aspect is, in any one of the first to sixth aspects,
The third member has a first joint portion welded to the first member and a second joint portion welded to the first joint portion to hold the peripheral edge portion of the penetration portion.

In the seventh aspect, the third member is formed separately in the first joint portion and the second joint portion, so that the welding method or welding conditions can be properly used in consideration of the material characteristics of the second member. Can be done.

For example, when the welded material of the melted third member is welded to the first member through the penetration portion, the short-circuit state and the arc state in which the arc spread is small due to the heat input required for melting can be obtained. Repeated short-circuit arc welding may be performed to form the first joint. After that, the second member may be formed by performing pulse welding with a positive electrode property or alternating current, which has a large arc spread, with a low heat input that does not melt the second member. As a result, the second joint can be formed while suppressing the amount of heat input to the second member.

The eighth aspect is in any one of the first to seventh aspects.
The fourth member includes a central portion that covers the central portion of the surface of the third member, and an outer peripheral portion that is welded to the central portion and the second member along the outer peripheral edge of the central portion. Have.

In the eighth aspect, the fourth member is formed separately in the central portion and the outer peripheral portion. For example, a central portion is formed by arc welding to cover the central portion of the surface of the third member, and then arc welding is performed along the outer peripheral edge of the central portion to form an outer peripheral portion, and the central portion and the outer peripheral portion are formed. You just have to make it familiar.

Further, an outer peripheral portion is formed by arc welding to cover the outer peripheral portion of the surface of the third member, and then arc welding is performed on the central portion of the surface of the third member to form the central portion, and the central portion and the outer peripheral portion are formed. You may try to make it familiar with the part.

According to the aspect of the present disclosure, it is possible to suppress the occurrence of electrolytic corrosion at the portion where the metal material and the dissimilar material overlap.

FIG. 1 is a side sectional view for explaining the joining structure according to the first embodiment. FIG. 2 is a side sectional view for explaining the joining structure according to the second embodiment. FIG. 3 is a side sectional view for explaining the joining structure according to the third embodiment. FIG. 4 is a side sectional view for explaining the joining structure according to the fourth embodiment. FIG. 5 is a side sectional view for explaining the joining structure according to the fifth embodiment. FIG. 6 is a side sectional view for explaining the joining structure according to the sixth embodiment. FIG. 7 is a side sectional view for explaining the joining structure according to the seventh embodiment. FIG. 8 is a side sectional view for explaining the joining structure according to the eighth embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that the following description of the preferred embodiment is essentially merely an example and is not intended to limit the present invention, its application or its use.

<< Embodiment 1 >>
FIG. 1 shows a first member 10 made of a metal material, a second member 20 made of a material difficult to weld to the first member 10, and a first fillering material. It shows a joining structure for joining a third member 30 made of a material to each other.

The first member 10 is a plate-shaped member made of a metal material.

The second member 20 is a plate-shaped member made of a material that is difficult to weld to the first member 10. The second member 20 is superposed on the upper side of the first member 10. The second member 20 has a circular penetrating portion 21.

Although the penetrating portion 21 is described as a circular through hole in the present embodiment, it may be an elliptical or elongated through hole.

The third member 30 is made of a filler material which is a metal material of the same type as the first member 10. Here, the metal materials of the same type are metals that can be welded to each other, and are not only the same materials but also metal materials having good weld bondability such as iron-based metal materials and non-iron-based metal materials. .. In other words, a similar metal material is a similar material that is compatible with welding.

Specifically, examples of the combination of the first member 10 and the third member 30 at the time of welding include the following. For example, as a combination of iron-based metal materials, there are mild steel and mild steel, stainless steel and stainless steel, mild steel and high-tensile steel (high-strength steel), high-tensile steel and high-tensile steel, and the like. Examples of non-ferrous metal materials include aluminum and aluminum, aluminum and aluminum alloys, and aluminum alloys and aluminum alloys.

Further, the second member 20 as a dissimilar material is a material of a material different from that of the first member 10 and the third member 30 as a metal material of the same type, and the first member 10 and the third member 20 are used. It is a material that is difficult to weld to the member 30.

For example, when the first member 10 and the third member 30 as the same type of metal material are made of an iron-based metal material, the second member 20 as a dissimilar material is a non-iron-based metal such as a copper material or an aluminum material. It is a material.

The third member 30 is welded to the first member 10 via the penetration portion 21. The third member 30 is provided with a flange portion 31 that presses the peripheral edge portion of the penetrating portion 21. Then, the third member 30 solidifies and contracts with respect to the first member 10, so that the second member 20, which is a different material, is compressed and fixed between the flange portion 31 and the first member 10. ..

By the way, in the portion where the flange portion 31 of the third member 30 and the second member 20 overlap, there is a possibility that electrolytic corrosion may occur due to the intrusion of moisture from the outside.

Therefore, in the present embodiment, the gap of the portion where the second member 20 and the third member 30 overlap is closed by the fourth member 40.

Specifically, the fourth member 40 is composed of a second filler material as a filler material which is a metal material of the same type that can be welded to the second member 20. The fourth member 40 covers the surface of the third member 30. The fourth member 40 is welded to the second member 20.

In the following description, the first member 10 is a mild steel material, the second member 20 is an aluminum material, the third member 30 which is a filler material for the first member 10 is a mild steel material, and the second member 20. A case where an aluminum material is used as the fourth member 40, which is a filler material for the above, will be described.

The arc welder 1 includes a nozzle 2 and a tip 3. The nozzle 2 supplies a shield gas or the like to the welded portion of the object to be welded. The tip 3 supplies a welding current to the third member 30.

The arc welder 1 generates an arc 5 by supplying a welding current while supplying a third member 30 to the first member 10 via the penetration portion 21. The third member 30 melted by arc welding is melt-bonded to the first member 10 and laminated in the penetrating portion 21. Then, the melted third member 30 fills the inside of the penetrating portion 21 and then flows out to the peripheral edge portion on the upper surface side of the penetrating portion 21 and spreads like a flange.

In the process in which the melted third member 30 becomes a bead, the third member 30 is provided with a flange portion 31 that presses the peripheral edge portion of the penetrating portion 21. The flange portion 31 projects radially outward from the penetration portion 21 on the surface of the second member 20 opposite to the first member 10 (upper surface in FIG. 1).

Then, the third member 30 solidifies and contracts with respect to the first member 10, so that the second member 20, which is a different material, is compressed and fixed between the flange portion 31 and the first member 10. ..

In this way, the welding wire as the filler material, which is the third member 30, is melted and supplied to the first member 10 via the penetrating portion 21 of the second member 20, thereby ensuring the strength. A flange-shaped bead is formed on the second member 20 so that the second member 20 can be sandwiched by compression fixing.

It is not necessary that the second member 20 and the third member 30 are melt-bonded. Even if an intermetallic compound is formed by melt-bonding, there is no problem because the purpose is compression fixing by the flange shape.

The arc welder 1 covers the surface of the third member 30 and welds the filler metal (fourth member 40) that can be welded to the second member 20 to the second member 20. Specifically, the arc welder 1 uses a pulse waveform that alternately repeats a peak current and a base current in DC welding due to positive electrode properties and AC welding in which the polarity is switched when the filler metal is welded to the second member 20. Perform pulse welding. In pulse welding, the spread of the arc 5 can be increased and the heat input to the filler metal side as a welding electrode can be increased with a low heat input that does not melt the second member 20, and the amount of welding can be increased.

In pulse welding, the droplets generated at the tip of the filler material are separated from the filler metal at a rate of once per pulse consisting of the peak current and the base current, and the flange portion 31 and the second member 20 side are separated. Move to withdrawal.

Here, DC welding based on positive electrode means that in welding by DC, the filler metal as the welding electrode is on the negative electrode side (negative electrode), and the first member 10 and the second member 20 as the base metal are on the positive electrode side. By setting it to the side (positive electrode), the heat input to the filler metal as a welding electrode is increased to perform welding. As a result, the heat input of the base metal is suppressed, and the melting of the filler metal as the welding electrode is promoted.

Further, in the AC welding by switching the polarity, in the AC welding, for example, the waveform of the peak current is set to the opposite polarity on the positive electrode side, and the waveform of the base current is set to the positive electrode side on the negative electrode side. At the peak current of the opposite polarity, the first member 10 and the second member 20 as the base material are on the negative electrode side, and the filler metal as the welding electrode is on the positive electrode side. At the time of the positive electrode base current, the first member 10 and the second member 20 as the base metal are on the positive electrode side, and the filler metal as the welding electrode is on the negative electrode side.

In this way, AC welding by AC that switches the polarity is performed by increasing the heat input to the first member 10 and the second member 20 as the base material at the peak current of the opposite polarity, and welding is performed with a positive electrode property base. Welding is performed by increasing the heat input to the filler metal as a welding electrode when an electric current is applied. As a result, the heat input of the base metal is suppressed as compared with the DC welding, and the melting of the filler metal as the welding electrode is promoted.

Although pulse welding is performed due to the positive electrode property, short-circuit arc welding that repeats an arc state and a short-circuit state may be performed as a welding method that suppresses heat input to the second member 20 although the spread of the arc 5 is small. ..

The arc welder 1 generates an arc 5 by supplying a welding current while supplying a filler material (fourth member 40) to the surface of the third member 30. The fourth member 40 melted by arc welding is melt-bonded to the second member 20 and laminated so as to cover the surface of the third member 30.

As described above, in the joint structure according to the present embodiment, the surface of the third member 30 is covered with the fourth member 40, and the fourth member 40 is welded to the second member 20 to form a second member. The gap between the member 20 and the third member 30 is closed with a fourth member 40 so as to prevent moisture from entering from the outside. By doing so, it is possible to prevent moisture from entering the overlapping portion of the second member 20 and the third member 30 from the outside.

As a result, it is possible to suppress the occurrence of electrolytic corrosion at the portion where the second member 20 and the third member 30 overlap, and to secure the joint strength.

In this way, unlike the third member 30, the second welding material (fourth member 40) as the filler material of the same material as the second member 20 is used for the second welding, and the third member is welded. A bead having a flange shape formed by the member 30 is welded so as to cover the molten metal to form a bead larger than the flange shape size. This enables melt bonding by the fourth member 40 made of the same material as the second member 20.

In addition, by melt-bonding the same materials together, it suppresses the intrusion of moisture from the outside and prevents electrolytic corrosion without using different construction methods such as commonly used adhesives, sealants, and sealants. It can be suppressed.

Basically, the first member 10 and the third member 30 are made of a material having a higher melting point than the second member 20 and the fourth member 40. Therefore, the interface between the third member 30 and the fourth member 40 is not melt-bonded or is slightly melt-bonded.

As a result, even if the fourth member 40 is beaded on the flange-shaped bead of the third member 30, there is no influence such as deformation of the flange shape of the third member 30, and the fourth member 40 A bead can be formed.

<< Embodiment 2 >>
Hereinafter, the same parts as those in the first embodiment are designated by the same reference numerals, and only the differences will be described.

As shown in FIG. 2, the second member 20 has a penetration portion 21. The penetrating portion 21 has a tapered portion 22 that tapers toward the first member 10.

The third member 30 is melted by arc welding. The melted third member 30 flows along the tapered portion 22 of the penetrating portion 21 so as to gather toward the center side of the penetrating portion 21, and is melt-bonded to the first member 10.

Then, the melted third member 30 fills the inside of the penetrating portion 21 and spreads like a flange on the upper surface of the tapered portion 22.

In the process of the melted third member 30 becoming a bead, the third member 30 is provided with a flange portion 31 for pressing the tapered portion 22 of the penetrating portion 21.

After that, the arc 5 is generated by supplying a welding current while supplying the fourth member 40 to the surface of the third member 30. The fourth member 40 melted by arc welding is melt-bonded to the second member 20 and laminated so as to cover the surface of the third member 30.

As described above, according to the joining structure according to the present embodiment, the tapered portion 22 is provided in the penetrating portion 21, and the flange portion 31 is solidified into a shape along the tapered portion 22 so as to protrude from the second member 20. The thickness of the flange portion 31 can be suppressed. As a result, the thickness of the fourth member 40 protruding from the second member 20 can also be suppressed.

<< Embodiment 3 >>
As shown in FIG. 3, the second member 20 has a stepped portion 25 that opens on a surface (upper surface in FIG. 3) opposite to the first member 10 and a penetrating portion formed on the bottom surface of the stepped portion 25. 21 and.

The third member 30 is melted by arc welding. The melted third member 30 is melt-bonded to the first member 10.

Then, after the melted third member 30 fills the inside of the penetrating portion 21, it flows out to the peripheral edge portion on the upper surface side of the penetrating portion 21, that is, the bottom surface of the stepped portion 25, and spreads like a flange.

In the process in which the melted third member 30 becomes a bead, the third member 30 is provided with a flange portion 31 that presses the peripheral edge portion of the penetrating portion 21.

After that, the arc 5 is generated by supplying a welding current while supplying the fourth member 40 to the surface of the third member 30. The fourth member 40 melted by arc welding is melt-bonded to the stepped portion 25 of the second member 20 and laminated so as to cover the surface of the third member 30.

As described above, according to the joining structure according to the present embodiment, the flange portion 31 of the third member 30 is arranged in the step portion 25 to prevent the flange portion 31 from popping out from the second member 20. Can be done. In addition, the thickness of the fourth member 40 protruding from the second member 20 can be suppressed.

<< Embodiment 4 >>
As shown in FIG. 4, the second member 20 has a stepped portion 25 that opens on a surface (upper surface in FIG. 4) opposite to the first member 10 and a penetrating portion formed on the bottom surface of the stepped portion 25. 21 and. The bottom surface of the step portion 25 is inclined toward the penetration portion 21.

The third member 30 is melted by arc welding. The melted third member 30 is melt-bonded to the first member 10. When the melted third member 30 touches the inclined surface of the stepped portion 25, it flows toward the penetrating portion 21 along the inclined surface of the stepped portion 25 and is melt-bonded toward the first member 10. To.

Then, the melted third member 30 fills the inside of the penetrating portion 21 and then flows out to the peripheral edge portion on the upper surface side of the penetrating portion 21, that is, the bottom surface of the stepped portion 25, and has a flange shape on the inclined surface of the stepped portion 25. Spread to.

In the process of the melted third member 30 becoming a bead, the third member 30 is provided with a flange portion 31 for pressing the inclined surface of the stepped portion 25.

After that, the arc 5 is generated by supplying a welding current while supplying the fourth member 40 to the surface of the third member 30. The fourth member 40 melted by arc welding flows along the inclined surface of the stepped portion 25. More specifically, it effectively flows so as to close the gap between the third member 30 and the second member 20 from the outside. Then, the melted fourth member 40 is melt-bonded to the second member 20 and laminated so as to cover the surface of the third member 30.

As described above, according to the joining structure according to the present embodiment, by inclining the bottom surface of the stepped portion 25 toward the penetrating portion 21, the melted third member 30 can easily flow toward the penetrating portion 21. ..

Further, the melted fourth member 40 flows along the inclined surface of the stepped portion 25, thereby effectively closing the gap between the third member 30 and the second member 20 from the outside side, and at the same time, the second member. It can be melt-bonded to the member 20 of 2.

Further, the flange portion 31 of the third member 30 can be arranged in the step portion 25 to prevent the flange portion 31 from popping out from the second member 20. In addition, the thickness of the fourth member 40 protruding from the second member 20 can be suppressed.

<< Embodiment 5 >>
As shown in FIG. 5, the second member 20 has a stepped portion 25 that opens on the overlapping surface (lower surface in FIG. 5) with the first member 10, and a penetrating portion 21 formed on the bottom surface of the stepped portion 25. And have.

The first member 10 has a bulging portion 15 that bulges toward the stepped portion 25. The bulging portion 15 is fitted in the stepped portion 25.

Then, the melted third member 30 fills the inside of the penetrating portion 21 and then flows out to the peripheral edge portion on the upper surface side of the penetrating portion 21 and spreads like a flange.

As described above, according to the joining structure according to the present embodiment, when the second member 20 is superposed on the first member 10, the stepped portion 25 is fitted to the bulging portion 15. , The first member 10 and the second member 20 can be easily aligned.

Further, when the third member 30 is melted by arc welding with respect to the first member 10, the vacant space portion on the back side of the bulging portion 15 in the first member 10 is used. A back wave can be sufficiently formed on the back surface of the first member 10, which is the surface opposite to the member 20 of 2. As a result, the strength can be further increased by so-called back wave welding, in which a weld bead is formed as if welded from the back side of the first member 10.

Further, by providing an empty space portion on the back side of the bulging portion 15 of the first member 10, a space is secured when the weld bead partially overhangs as a back wave from the back surface side of the first member 10. Can be done.

<< Embodiment 6 >>
As shown in FIG. 6, the second member 20 has a penetration portion 21.

The third member 30 is melted by arc welding. The third member 30 has a first joint portion 35 welded to the first member 10 and a second joint portion 36 welded to the first joint portion 35 to form the flange portion 31.

Specifically, when the molten third member 30 is welded to the first member 10 via the penetration portion 21, the short-circuit state and the arc in which the spread of the arc 5 is small due to the heat input required for melting. Short-circuit arc welding that repeats the state is performed to form the first joint portion 35. After that, the second member 20 is subjected to pulse welding with a positive electrode property having a large spread of the arc 5 and alternating current with a low heat input that does not melt, to form the second joint portion 36. As a result, the flange portion 31 can be formed while suppressing the amount of heat input to the second member 20.

In the process in which the melted third member 30 becomes a bead, the third member 30 is provided with a first joint portion 35 and a second joint portion 36. The first joint portion 35 is melt-bonded to the first member 10. The second joint portion 36 is melt-bonded to the first joint portion 35 to form a flange portion 31 that presses the peripheral edge portion of the penetration portion 21.

It is preferable to weld the upper part of the first joint portion 35 so that the center is recessed.

This makes it easier to determine the welding position when the second joint portion 36 is welded to the first joint portion 35. Further, the melted second joint portion 36 can easily gather on the recessed center side of the first joint portion 35, and the shape of the second joint portion 36 can be further adjusted.

As described above, according to the joint structure according to the present embodiment, the material of the second member 20 is formed by separately forming the third member 30 into the first joint portion 35 and the second joint portion 36. Welding methods or welding conditions can be selected in consideration of the characteristics.

The shapes of the first member 10 and the second member 20 are merely examples, and may be other combinations.

<< Embodiment 7 >>
As shown in FIG. 7, the second member 20 has a penetration portion 21.

The third member 30 is melted by arc welding. The melted third member 30 is melt-bonded to the first member 10. The melted third member 30 fills the inside of the penetrating portion 21 and then flows out to the peripheral edge portion on the upper surface side of the penetrating portion 21 and spreads like a flange.

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

Specifically, the arc 5 is generated by supplying a welding current while supplying the fourth member 40 to the central portion of the surface of the third member 30. The fourth member 40 melted by arc welding is laminated so as to cover the surface of the third member 30. As a result, the central portion 41 of the fourth member 40 is formed.

Then, by turning the nozzle 2 of the arc welder 1 along the outer peripheral edge of the central portion 41, the molten fourth member 40 is supplied to the outer peripheral edge of the central portion 41. The melted fourth member 40 is welded to the central portion 41 and the second member 20. As a result, the outer peripheral portion 42 of the fourth member 40 is formed.

As described above, according to the joining structure according to the present embodiment, the central portion 41 is formed by arc welding to cover the central portion of the surface of the third member 30, and then along the outer peripheral edge of the central portion 41. By performing arc welding to form the outer peripheral portion 42, the central portion 41 and the outer peripheral portion 42 can be made familiar with each other.

<< Embodiment 8 >>
As shown in FIG. 8, the second member 20 has a penetration portion 21.

Specifically, by turning the nozzle 2 of the arc welder 1 along the outer peripheral edge of the flange portion 31, the molten fourth member 40 is supplied to the outer peripheral edge of the flange portion 31. The melted fourth member 40 is welded to the second member 20 along the outer peripheral edge of the flange portion 31. As a result, the outer peripheral portion 42 of the fourth member 40 is formed.

Then, the arc 5 is generated by supplying the welding current while supplying the fourth member 40 to the central portion of the surface of the third member 30. The fourth member 40 melted by arc welding is melt-bonded to the outer peripheral portion 42 and laminated so as to cover the surface of the third member 30. As a result, the central portion 41 of the fourth member 40 is formed.

As described above, according to the joining structure according to the present embodiment, the outer peripheral portion 42 is formed by arc welding to cover the outer peripheral portion of the surface of the third member 30, and then the center of the surface of the third member 30. By performing arc welding on the portion to form the central portion 41, the central portion 41 and the outer peripheral portion 42 can be made familiar with each other.

<< Other Embodiments >>
The embodiment may have the following configuration.

In the present embodiment, arc welding is performed on the first member 10, but the present invention is not limited to this embodiment. Specifically, the fillering material as the third member 30 includes a melting electrode type (consumable electrode type) and a non-melting electrode type (non-consumable electrode type). Therefore, for example, instead of the welding wire as the filler wire of the molten electrode type (consumable electrode type) used as the third member 30, the filler wire as the filler wire of the non-melting type (non-consumable electrode type). May be used to perform laser filler welding to perform laser welding on the first member 10.

In the laser filler welding, the first member 10 is irradiated with a laser to ensure the penetration of the surface of the first member 10 firmly, and then only the supplied filler wire is irradiated with the laser to obtain a third member. The filler wire, which is the member 30, can be melted. As a result, the inside of the penetrating portion 21 can be filled with the third member 30 while suppressing the heat input to the second member 20.

Further, by defocusing to secure a large beam diameter in order to reduce the power density of the laser, it is possible to apply preheating to the second member 20 by utilizing the outer peripheral portion of the beam diameter of the laser. As a result, the molten filler wire, which is the third member 30, can be easily adapted to the second member 20. Then, by this effect, the gap between the second member 20 and the third member 30 is closed so as to prevent moisture from entering from the outside, so that the second member 20 and the third member 30 can be combined with each other. It is possible to prevent moisture from entering the overlapping portion of the above.

Further, the third member 30 and the fourth member 40 may be formed by hybrid welding using arc welding and laser welding. Specifically, the third member 30 may be formed by laser filler welding, and the fourth member 40 may be formed by hybrid welding, which is formed by arc welding.

Further, the third member 30 is formed by arc welding using a melt-type filler material, and the fourth member 40 is formed by laser filler welding using a filler wire as a non-melt-type filler material. It may be formed by hybrid welding to be formed.

Further, a configuration in which these laser weldings are combined may be used. For example, the duty (Duty), which is the ratio of ON and OFF of the pulse oscillation output, which defocuses to reduce the power density of the laser and reduces the output relatively, or changes the continuous output of the laser to the pulse oscillation output. At least one or more points on the outer peripheral side of the penetrating portion 21 of the second member 20 and the upper side of the third member 30 are preheated by irradiating a laser having a reduced output such as lowering the voltage. May be good. By doing so, it is possible to improve the familiarity of the second member 20, the third member 30, and the fourth member 40 during welding. As a result, it is possible to prevent moisture from entering the overlapping portion of the second member 20, the third member 30, and the fourth member 40 from the outside.

As described above, the present invention is extremely useful and industrially applicable because it has a highly practical effect of suppressing the occurrence of electrolytic corrosion at the portion where the metal material and the dissimilar material overlap each other. The possibility is high.

10 1st member 15 bulging part 20 2nd member 21 penetration part 22 taper part 25 step part 30 3rd member 31 flange part 35 1st joint part 36 2nd joint part 40 4th member 41 central part 42 The outer periphery

Claims

It is composed of a first member made of a metal material, a second member made of a material that is difficult to weld to the first member, and a filler metal welded to the first member. It is a joint structure in which the third member is joined to each other.
The second member is formed with a penetrating portion penetrating toward the first member.
The third member is welded to the first member via the penetration portion.
A joining structure composed of a filler material that can be welded to the second member, covering the surface of the third member, and having a fourth member welded to the second member.
In claim 1,
The third member has a flange portion on the surface of the second member opposite to the first member, which projects radially outward from the penetration portion and presses the peripheral edge portion of the penetration portion. Joined structure.
In claim 1,
The penetrating portion has a tapered portion that tapers toward the first member.
The third member has a joint structure that holds down the tapered portion.
In claim 1,
The second member has a joint structure having a stepped portion opened on a surface opposite to the first member and the penetrating portion formed on the bottom surface of the stepped portion.
In claim 4,
The bottom surface of the stepped portion is a joint structure inclined toward the penetrating portion.
In claim 1,
The second member has a stepped portion that opens in the overlapping surface with the first member, and the penetrating portion formed on the bottom surface of the stepped portion.
The first member has a joint structure having a bulging portion that bulges toward the stepped portion.
In any one of claims 1 to 6,
The third member has a joint structure having a first joint portion welded to the first member and a second joint portion welded to the first joint portion to press the peripheral edge portion of the penetration portion.
In any one of claims 1 to 7,
The fourth member has a central portion that covers the central portion of the surface of the third member, and an outer peripheral portion that is welded to the central portion and the second member along the outer peripheral edge of the central portion. Welding structure to have.