JP2009248184A - Welded joint, and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a welded joint wherein the remaining of blowholes is suppressed in a weld bead without increasing cost and stages, and to provide a method for producing the same. <P>SOLUTION: This invention relates to the welded joint 10 obtained by welding the superimposed parts of the first member 1 and the second member 2, wherein a melting width W3 is larger than the sheet width W1 in the superimposed part, of the first member or the second member. In the method for producing the welded joint, when the superimposed first member and second member are welded, the melting width is made larger than the sheet width in the superimposed part, of the first member or the second member. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a welded joint that can be preferably used, for example, when a member having a component having a boiling point lower than that of a main component is used, such as a plate having a surface treatment layer such as plating or a coating film, and a manufacturing method thereof. Is.

  If the surface treated layer has a lower boiling point than that of the plate when the surface treated plate and non-surface treated plate are welded together by non-contact welding such as electron beam welding or laser welding, the surface treated layer The components of vaporize. In the melting part, pressure is applied toward the center bottom, and when the vaporized vapor is generated near the center of the melting part, it is pushed down to the center bottom by the pressure and pushed up to the upper surface along the wall surface of the melting part. If it occurs near the wall surface, it is exhausted along the wall surface. Therefore, at the time of solidification where the exhaust path is long and no pressure is applied, the steam is not pushed out to the upper surface but remains in the melted portion to become a blow hole, and the welding quality is deteriorated. In order to reduce the influence of such low boiling point material vapor, there is a method in which protrusions and grooves are provided on the overlapping surfaces of the plate material, and the vapor is exhausted from a gap formed between the upper member and the lower member. (For example, refer to Patent Document 1).

JP 2001-162388 A (2nd page, FIG. 2)

  However, when the protrusions and grooves are provided, if the gap amount cannot be properly controlled, welding is poor when it is large, and steam is not exhausted when it is small. When high accuracy is required for the management of the gap due to welding of a thin plate or the like, there is a problem that it is not applicable if the management cost increases or the adjustment amount exceeds the limit performance of the apparatus. In addition, a bending process or the like is required to provide the protrusion, and a cutting process or the like is required to provide the groove, resulting in a problem that productivity is reduced by adding a process.

  The present invention has been made to solve the above-described problems of the prior art, and an object thereof is to provide a welded joint that suppresses residual blowholes without increasing costs and processes and a method for manufacturing the same. Is.

The welded joint according to the present invention is a welded joint in which the overlapped portion of the first member and the second member is welded, and the melt width (width of the melt bead) is the plate width in the overlapped portion of the first member and the second member. It is characterized by being larger.
In the method for manufacturing a welded joint according to the present invention, when the superposed first member and the second member are welded, the melt width is made larger than the plate width in the superposed portion of the first member or the second member. It is characterized by that.

In the welded joint of the present invention, steam in the width direction in the melting process acts so as to be pushed out into the outside air without being constrained in the width direction by the pressure pushing down the melted portion, so that the weld bead of the obtained joint Has suppressed blowhole residue and has high welding quality and reliability. Further, there is no cost increase.
Further, in the method for manufacturing a welded joint according to the present invention, the steam generated in the melted portion is restrained in the plate width direction by making the melt width larger than the plate width in the overlapped portion of the first member or the second member. Since it is pushed out into the outside air, the exhaust effect is enhanced, and a welded joint in which the remaining blowholes are suppressed can be obtained. Further, there is no increase in cost or process.

Embodiment 1 FIG.
1 and 2 are diagrams for explaining a welded joint and a manufacturing method thereof according to Embodiment 1 of the present invention. FIG. 1 (a) is a top view schematically showing the welded joint, and FIG. 2 is a cross-sectional view of the welded joint a) viewed from the width direction, and FIG. 2 is a diagram schematically illustrating a cross-section of the welded joint shown in FIG. 1 viewed from the longitudinal direction during welding. In the figure, a plate member 1 as a first member and a plate member 2 as a second member, which are welded materials, are superposed in the plate thickness direction so as to face each other. A surface treatment layer 1 a described later is formed on the front surface and the back surface of the plate material 1, and the surface treatment layer 1 a contains components whose boiling points are lower than those of the plate material 1 and the plate material 2. Heat input H by non-contact welding is applied to the upper surface side of the plate material 1 to form a molten bead 3 and the plate material 1 and the plate material 2 are welded. As the heat input H, for example, laser welding, plasma arc welding, or electron beam welding having a small heat-affected region is preferably used. A typical characteristic portion of the welded joint 10 according to the present invention is that the melt width W3 of the melt bead 3 is larger than the plate widths W1 and W2 of the plate members 1 and 2 (in this example, W1 = W2) as shown in the figure. It is configured as follows.

  If the irradiation spot diameter of the heat input H is too small compared to the plate width W1, it is difficult to increase the melt width W3. Therefore, the diameter of the irradiation spot diameter is desirably about 30% or more of the plate width W1. Further, when the energy of the heat input H is small, the sheet material cannot be melted to the width W1 or more, and conversely, when the energy is large, the melted part is blown off or the melted part is blown off due to excessive pressure, resulting in a decrease in quality. The energy suitable for each is selected according to conditions such as the materials 1 and 2, the plate width, the plate thickness, the surface treatment method, the thickness of the surface treatment layer 1a, and the irradiation spot diameter. Here, energy is the product of irradiation peak power and irradiation time. The irradiation peak power is likely to affect the penetration depth direction, and the irradiation time is likely to affect the melting width. In order to increase the melting width W3, It is preferable to lengthen the irradiation time. In particular, when the heat input H is a laser, if the reflectance of the plate material 1 is high, the required energy increases and the melted portion tends to blow away in the width direction. Therefore, the reflectance is preferably less than about 75%. . In the case where the reflectance of the plate 1 is higher than about 75%, for example, a plating process with a low reflectance may be performed to lower the reflectance.

  In the welded joint configured as described above, a component having a lower boiling point than the base material constituting the surface treatment layer 1a is vaporized during melting in the welding process, but as shown in FIG. By making the width W3 larger than the plate widths W1 and W2 at the overlapping portions of the plate materials 1 and 2, both side surfaces of the molten bead 3 in the width direction (vertical direction in FIG. 1A) are exposed to the outside air. In the melting part, the pressure is applied toward the center bottom part and escapes from both side surfaces in the width direction. Therefore, as shown in FIG. 2, the steam 4 generated in the melting portion 31 is pushed out into the surrounding outside air without being restricted in the width direction (left and right direction in FIG. 2), so that the exhaust effect is enhanced. . As a result, the occurrence of blow holes is suppressed. In addition, the material of the plate materials 1 and 2 which are to-be-welded materials is not particularly limited. For example, in the case of a current-carrying conductor in an electronic device or the like, copper or a copper alloy is preferably used. As the surface treatment layer 1a, for example, a plating treatment of tin, nickel, silver, gold or the like is performed in order to ensure adhesion of a fitting portion (not shown) for constituting a connector or to obtain solder wettability, etc. Is often applied.

  Of these, tin and the like have a lower boiling point than the base material of the material to be welded, so the plating on the irradiated part and the overlapped surface is melted and stirred by the melting part 31. Cause blowholes. Further, surface treatment agents such as components in the plating bath and brightener remaining during plating are also involved in melting and cause blow holes, but in the first embodiment as described above, due to the exhaust improvement effect, Blow holes are suppressed. Furthermore, when the material to be welded is a copper alloy, if the composition contains a component having a boiling point lower than that of the main component, the component having a lower boiling point is vaporized during welding. is there. In particular, when the plate materials 1 and 2 that are materials to be welded are used as conductors for electronic equipment and the cross-sectional area is small with respect to the energized current, blow holes due to steam generation increase the electrical resistance and reduce the efficiency of the electronic equipment. In addition, there is a risk that the temperature inside the electronic device is increased due to heat generation in the welded portion and the reliability of the electronic component is reduced. However, the present invention is suitable for welding a member that is a conductor inside the electronic device. Remarkable effects are obtained, reliability and durability are improved, and it contributes to energy saving.

  Further, when the plate materials 1 and 2 are building materials, home appliance structural materials, automobile materials, etc., steel plates are often used. In this case, the surface treatment layer 1a is galvanized or the like in order to obtain corrosion resistance. Zinc has a remarkably lower boiling point than steel and is likely to cause blowholes. However, applying the invention of Embodiment 1 has an effect of improving the exhaust of steam generated in the melting process. If the melt width W3 is formed by dividing the heat input frequency into several times, it is difficult to exhaust steam when the melt width W3 is smaller than the plate width W1 (W2). It is desirable that Even when heat is input a plurality of times, it is desirable that the melt width W3 be larger than the plate width W1 by a single heat input. In addition, although the surface treatment layer 1a illustrated about the case where it provided in one board | plate material 1, even if it is given to the board | plate material 2 side or both the board | plate material 1 and the board | plate material 2, the same exhaust effect is obtained. is there.

As described above, according to the first embodiment, in the welded joint in which the plate member 1 having the surface treatment layer 1a subjected to the plating treatment as the polymerized first member and the plate member 2 as the second member are welded, Since the melt width W3 is configured to be larger than the plate width W1 of the plate material 1 and the plate width W2 of the plate material 2, the number of surfaces where the melted portion 31 in contact with the outside air in the welding process is increased, and thus the surface treatment layer 1a is derived. The effect of exhausting steam by the low boiling point component is enhanced, and there is an effect that the blowhole is suppressed and the joint has no defect. Moreover, there is an exhaust effect not only when the surface treatment layer 1a applied to the material to be welded is a metal film such as plating, but also when the surface treatment layer 1a is a non-metal film such as a paint film. An exhaust effect is also obtained for the vapor of the component.
Further, according to the welded joint manufacturing method of the first embodiment, in the welding process, the melt width W3 is made larger than the plate width W1 of the plate material 1 and the plate width W2 of the plate material 2, so that the melted portion 31 is outside air. Since the area in contact with the surface treatment layer 1a is increased, the exhaust effect of the steam 4 due to the low boiling point component derived from the surface treatment layer 1a is particularly enhanced, and a defect-free welded joint with suppressed blowholes can be obtained. Moreover, the durability and reliability of the obtained welded joint 10 are improved, and the yield is also improved by suppressing blowholes.

Embodiment 2. FIG.
3A and 3B are diagrams schematically illustrating a welded joint according to Embodiment 2 of the present invention. FIG. 3A is a top view, and FIG. 3B is a cross-sectional view of the welded joint of FIG. FIG. Note that the same reference numerals denote the same or corresponding parts throughout the drawings, and redundant description is omitted. In the second embodiment, when the plate thickness of the material to be welded is thin, the molten bead becomes a through bead, and pressure is prevented from being released from the through portion during penetration. In the figure, the total thickness D of the plates 1 and 2 is configured to be larger than the melting depth D3.

In the case of a penetrating bead, since the pressure is released from the penetrating part at the time of penetrating, the vapor generated near the side surface is difficult to be exhausted, but at the same time as the pressure released at the time of penetrating, the melt is easily discharged from the penetrating part. The melt may adhere to other places and degrade the quality. However, in the second embodiment configured as described above, the total thickness D of the plate members 1 and 2 is made larger than the melting depth D3 to form a non-penetrating bead, so that the exhaust effect is achieved at the end of welding, that is, before solidification. Can be obtained. At least from the top surface to the mating surface of the joint, the side surface in the plate width direction is melted to greatly reduce the effects of blowholes and explosions due to the low boiling point components of the surface treatment layer on the mating surface. Can be eliminated.
The melt width W3 may be made smaller than the melt depth D3. In that case, the distance from the center bottom of the melted portion is shorter on the side surface than on the upper surface, so that the exhaust effect can be further enhanced.

Embodiment 3 FIG.
FIG. 4 is a cross-sectional view schematically illustrating a welded joint according to Embodiment 3 of the present invention. As shown in FIG. 4, in the third embodiment, the plate material 1 and the plate material 2 are superposed with a small allowance in the abutting direction, and the edges 1b and 2a of the superposed portion are welded together with the width direction. is there. When the edge portions 1b and 2a of the overlapping portions of the plate material 1 and the plate material 2 are melted as shown in the figure, the melted portion 31 can also contact the outside air in the longitudinal direction (left and right direction in the figure). In addition to the width direction, the number of surfaces in contact with the surface further increases, and the exhaust effect can be further enhanced. In addition, although the thing which both edge parts of the board | plate material 1 and the board | plate material 2 were welded was illustrated, the improvement effect of exhaust_gas | exhaustion is acquired even if it melt | dissolves straddling arbitrary one edge part over the width direction.

Embodiment 4 FIG.
5A and 5B are diagrams schematically illustrating a welded joint according to Embodiment 4 of the present invention. FIG. 5A is a top view, and FIG. 5B is a cross-sectional view of the welded joint of FIG. FIG. In the drawing, the plate width in the overlapping portion of the plate member 1 as the first member and the plate member 2 as the second member has a plurality of strip-like tooth portions 11 and 21 so as to be less than about twice the plate thickness. The tooth portions 11 and 21 are divided into comb teeth, and the melting width W3 is the width W11 and W21 of the tooth portions 11 and 21 (W11 = W21 in this example) as in the first embodiment. Here, it is welded so that the width of the tooth portion becomes larger than the plate width. In addition, in order to process the superposition | polymerization part of a to-be-welded material in a comb-tooth shape, it can form easily by pressing using a desired type | mold. Further, for example, by preparing a plurality of dies having different widths W11 (W21), a desired welded joint can be obtained by changing the dies according to the plate widths, plate thicknesses, and the like of the plate members 1 and 2.

When the plate width is large compared to the plate thickness, increasing the energy causes blowout of the melted portion before melting to the end in the width direction and the quality deteriorates. Therefore, the plate width is preferably less than about twice the plate thickness. . However, in order to ensure the strength, thermal conductivity, or conductivity of the welded joint, a plate width of about twice or more the plate thickness may be required, but this Embodiment 4 also meets such a requirement. As shown in FIG. 5, the vicinity of the welded portion is formed by dividing it into comb teeth, and the plate width of each welded portion, that is, the widths W11 and W21 of the tooth portions 11 and 21 are the plate thicknesses. Therefore, it is possible to suppress the blowout (explosion) and blowhole of the melted portion during welding.
As described above, according to the fourth embodiment, the overlapping width of the plate material 1 and the plate material 2 is formed in a comb shape so that the plate width is less than about twice the plate thickness, and the melting width is larger than the width of the tooth portion. Since welding is performed so as to increase, the exhaust effect can be enhanced while maintaining the strength, thermal conductivity, or conductivity of the welded joint, and a high-quality welded joint without blowholes can be obtained.

  In the first to fourth embodiments, the case where the plate width W1 of the plate member 1 as the first member and the plate width W2 of the plate member 2 as the second member are made equal is described. The widths may not be equal. Even in that case, the same effect can be expected by making the melt width larger than the plate width. In addition, when a welded material having a component having a lower boiling point than that of the base material is used for at least one of the welded materials to be polymerized, a welded material that does not contain such a low-boiling component is used. It can also be applied to welded joints. Furthermore, although illustrated about the case where two members, the 1st member and the 2nd member, are welded, it is not necessarily limited to this, For example, 3 or more board | plate materials can also be welded.

It is a figure which illustrates the welded joint by Embodiment 1 of this invention typically, (a) is a top view, (b) is sectional drawing seen from the width direction. It is a figure which illustrates typically the cross section which looked at the fusion | melting part at the time of welding of the welded joint shown by FIG. 1 from the longitudinal direction. It is a figure which illustrates the welded joint by Embodiment 2 of this invention typically, (a) is a top view, (b) is sectional drawing which looked at the welded joint of FIG. 3 (a) from the width direction. It is sectional drawing which illustrates typically the welded joint by Embodiment 3 of this invention. It is a figure which illustrates typically the weld joint by Embodiment 4 of this invention, (a) is a top view, (b) is sectional drawing which looked at the weld joint of FIG. 5 (a) from the width direction.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 board | plate material (1st member), 1a surface treatment layer, 1b edge part, 2 board | plate material (2nd member), 2a edge part, 11, 21 tooth part, 3 fusion | melting bead, 31 fusion | melting part, 4 steam, 10 weld joint, D Total thickness of plate materials 1 and 2; D3 melt depth; W1 plate width of plate material 1; W2 plate width of plate material 2; W11 width of tooth portion 11; W21 width of tooth portion 21; W3 melt width of melt bead 3; H Heat input.

Claims (9)

  A welded joint obtained by welding overlapping portions of a first member and a second member, wherein the melt width is larger than the plate width in the overlapping portion of the first member or the second member.   The weld joint according to claim 1, wherein the melt width is smaller than the melt depth.   The weld joint according to claim 1 or 2, wherein a melting depth is smaller than a total dimension of a plate thickness of the first member and the second member.   The weld joint according to any one of claims 1 to 3, wherein a plate width at a welded portion of the first member and the second member is less than about twice the plate thickness.   The welded joint according to any one of claims 1 to 4, wherein the overlapping portions of the first member and the second member are each formed in a comb-like shape, and the tooth portions are welded to each other. .   The welded joint according to any one of claims 1 to 5, wherein an edge of the overlapped portion of the first member or the second member is welded.   The welded joint according to any one of claims 1 to 6, wherein at least one of the first member and the second member is provided with a surface treatment layer containing a material having a boiling point lower than that of the base material. .   A method for producing a welded joint, comprising: welding a superposed first member and a second member to make a melt width larger than a plate width in a superposed portion of the first member or the second member.   The method for manufacturing a welded joint according to claim 8, wherein welding is performed by one heat input by non-contact welding.

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