JPH07211181A - Welding method for plate-shaped conductor and weld structure - Google Patents

Abstract

PURPOSE:To establish a method and structure for welding a plate-shaped conductor which can certainly weld a plurality of such conductors, for example, bus bar, terminal plate, etc. CONSTITUTION:A plurality of plate-shaped conductors 1, 2 are piled one over another, and a cut-rise part 6 is formed upright using press dies 4, 5 in the overlapping part, and the formost 6a of this part 6 is irradiated with a laser beam 7. In the overlapping part of the plate-shaped conductors 1, a cut-rise part 6 is formed consisting of a plurality of rising pieces 61, 62 which are in tight attachment, and these pieces 61, 62 are welded together by laser irradiation. At the base board part of a terminal, a fold-back plate is provided in continuity confrontingly, and plate-shaped conductors are arranged between the base board part and fold-back plate, and a cut-rise part 6 is formed in the overlapping part 3 of the base board part, fold-back plate, and plate-shaped conductors.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welding method and a welding structure for a plate-shaped conductor capable of reliably welding a plurality of plate-shaped conductors such as a bus bar and a terminal plate.

[0002]

2. Description of the Related Art FIG. 4 shows a conventional method for welding a plate-shaped conductor described in Japanese Patent Laid-Open No. 57-170419. This welding method uses the contact member 28 under the terminal plate 27.
And a metal member 29 having good heat conductivity such as copper alloy is laid under the contact member 28, and the terminal plate 27 is attached to the mold 30.
The laser beam 31 is radiated from above the terminal plate 27 toward the contact member 28 to weld the two together. According to this method, the fusion zone 32 is formed to be shallow and wide, excessive welding is prevented, and a good structure
Strength is obtained.

However, in the above-mentioned conventional method, the tangent line 33 of the fusion zone 32 and the joint surface 34 are formed because the aspect ratio (melting depth H / melting diameter D) becomes small as shown in FIG. When the angle θ varies, the contact member 28
There was a concern that the melt-in amount h on the side would decrease and the welding strength would decrease. In addition, the fact that the melting diameter D becomes large is obviously disadvantageous for electronic devices and the like that are required to be downsized. Further, since the molten state of the contact member 28 cannot be visually confirmed, a destructive inspection such as a macrostructure inspection of the fused portion 32 and a strength test must be performed, which requires a lot of inspection man-hours.

[0004]

SUMMARY OF THE INVENTION In view of the above points, the present invention is capable of reliably welding a plurality of plate-shaped conductors, prevents enlargement of the melted portion, and makes it easy to visually check the melted portion. An object of the present invention is to provide a welding method and a welding structure of a plate-shaped conductor that can be inspected.

[0005]

In order to achieve the above object, the present invention is directed to stacking a plurality of plate-shaped conductors, forming a cut-and-raised part on the overlapped part by a press die, and cutting the cut-and-raised part. A method of welding a plate-shaped conductor in which the tip of the raised portion is irradiated with a laser beam, and a cut-raised portion formed by a plurality of cut-and-raised pieces that are in close contact with each other is formed at the overlapping portion of the plurality of plate-shaped conductors. We also employ a welded structure of plate-shaped conductors in which cut-and-raised pieces are welded together by laser irradiation or the like.

[0006]

The overlapping portions of the plate-shaped conductors are punched or formed in a compressed state by a press die to form cut-and-raised portions composed of a plurality of closely-cut cut-and-raised pieces. The cut-and-raised portion projects outside the plate-shaped conductor,
A plurality of cut-and-raised pieces are welded to each other due to laser beam irradiation or the like.

[0007]

EXAMPLES FIGS. 1 (a) to 1 (c) show the melting of a plate conductor according to the present invention.
1 illustrates an example of a contact method. That is, first, in FIG.
As shown in (a), the bus bar is a plate-shaped conductor made of two conductive metals.
ー Overlap the terminal parts of 1 and 2, and overlap this overlapping part 3.
It is punched with the metal upper and lower press dies 4 and 5, and is shown in Fig. 1 (b).
As shown in FIG.
Form on the body. Then, as shown in FIG. 1 (c), the cut-and-raised part
The front end 6a of 6 is irradiated with the laser beam 7 from the front,
Two cut and raised pieces 6 of the cut and raised portion 6₁, 6 ₂The mutual
Weld to. When the plate thickness T of the cut and raised portion 6 is thin
Laser beam from the direction perpendicular to the tip of the cut-and-raised part 6
You may irradiate 7 '.

As shown in FIG. 1 (a), the upper press die 4 has a sloped wall 8 which is raised from the substrate portion 11 in a quadratic curve and curved.
And a vertical wall 9 which is erected straight from the apex 8a of the inclined wall
The lower press die 5 has a concave inclined wall 10 along the inclined wall 8, and a vertical wall 13 facing the substrate portion 12 from the tip apex 10a and the lowest point 10b of the inclined wall 10, 14 and. The bus bars 1 and 2 are cut at both the tip apex 10a of the lower press die 5 and both edges of the inclined wall 10 to form the inclined walls 8 and 10 of the upper and lower dies 4 and 5 with the apex 8a of the upper press die 4 as a fulcrum. The two bus bars 1 and 2 are compressed and cut along the curved line.

It should be noted that slits (not shown) in the shape of cut-and-raised parts are previously formed in the overlapping portions 3 of the bus bars 1 and 2 and the cut-and-raised portions 6 are raised without punching with the press dies 4 and 5. Alternatively, only contact molding may be performed.

Two cut-and-raised parts forming the cut-and-raised part 6
Strain piece 6₁, 6₂Is compressed by the upper and lower press dies 4 and 5
As shown in Fig. 1 (b), they are firmly attached. Therefore,
Good penetration and reproducibility in laser welding of (c)
It enables high-level welding. The tip of the cut-and-raised part 6
Since the ends project outward from the bus bar 1, the fusion zone 15
Can be confirmed visually or with a CCD camera. Further cut and raised
The base 6 has a small area for the bus bars 1 and 2
Since it is coupled with b, it can be connected to the bus bars 1 and 2 during welding.
Low heat transfer (heat loss) and high melting efficiency. In addition, cut
Raised piece 6₁, 6 ₂Is not limited to two, but three or more
It is possible.

FIG. 2 shows three cut and raised pieces 16.₁, 1
6₂, 16₃Welding of plate conductors 17, 18 and 19 having
1 shows an example of a structure. This structure is
Fold the terminal 21 having the touch portion 20 from one end of the substrate portion 19.
The return plate 17 is formed in series to face the substrate portion 19, and
The terminal portion of the bus bar 18 is provided between the portion 19 and the folding plate 17.
18a is inserted and sandwiched, and the board portion 19 and the bus bar terminal portion
18a and the folding plate 17 in front of the overlapping portion 22
Press with the upper and lower press dies 4 and 5 in the welding method.
3 pieces of cut and raised pieces that adhere to each other₁~ 16 ₃More successful
The cut-and-raised portion 16 is formed.

The cut-and-raised portion 16 is irradiated with the laser beam 7 on the tip 16a as shown in FIG.
Depending on the strength of the cut, the cut-and-raised part 16 as shown in Fig. 3 (b)
The whole is melted and the melting portion 24 is accommodated in the hole 23. Also in this case, the state of the fusion zone 24 can be easily observed from the outside.

[0013]

As described above, according to the present invention, since the cut-and-raised portion which is the welded portion projects outward from the plate-shaped conductor which is the base material, and the tip of the cut-raised portion is irradiated with the laser beam, The cut-and-raised portion is melted in the entire plate thickness direction, that is, each cut-and-raised piece is surely melted, and reliable welding with no penetration failure is achieved. Here, since the cut-and-raised pieces are pressed against each other by the pressing process and are in close contact with each other, more reliable welding is possible.

Further, since the melted portion does not expand in diameter unlike the conventional nugget, that is, it does not become larger than the cut-and-raised portion, it can be applied to small electronic devices and the like. Furthermore, since the welding state can be confirmed from the outside,
Destructive inspection such as macro structure inspection and strength test of welded parts can be simplified, and inspection man-hours can be reduced.

[Brief description of drawings]

1 (a) to 1 (c) are side views showing an embodiment of a method for welding a plate-shaped conductor according to the present invention in the order of steps.

FIG. 2 is a perspective view showing an example of a welded structure of a plate-shaped conductor according to the present invention.

FIG. 3A is a vertical cross-sectional view showing a state in which a cut-and-raised portion is irradiated with a laser, and FIG. 3B is a vertical cross-sectional view after welding.

FIG. 4 is a vertical sectional view showing a conventional example.

FIG. 5 is a vertical sectional view showing one conventional problem.

[Explanation of symbols]

1,2,18 Bus bar (plate conductor) 3,22 Stacking part 4,5 Press type 6,16 Cut and raised part 6 _{1 to} 6 ₂ , 16 _{1 to} 16 ₃ Cut and raised piece 7,7 'Laser beam 17 Folded back Plate (plate conductor) 19 Substrate (plate conductor)

Claims (3)

[Claims] 1. A plurality of plate-shaped conductors are superposed on each other, and a cut-and-raised portion is formed on the superposed portion by a press die.
A welding method for a plate-shaped conductor, characterized in that the tip of the cut-and-raised portion is irradiated with a laser beam. 2. A cut-and-raised portion composed of a plurality of cut-and-raised pieces that are in close contact with each other is formed in an overlapping portion of a plurality of plate-shaped conductors, and the plurality of cut-and-raised pieces are welded to each other by laser irradiation or the like. Characteristic plate-shaped conductor welding structure. 3. A fold-back plate is formed opposite to and connected to a substrate portion of the terminal, a plate-shaped conductor is arranged between the substrate portion and the fold-back plate, and the substrate portion, the fold-back plate and the plate-shaped conductor are overlapped with each other. The welded structure for a plate-shaped conductor according to claim 2, wherein the cut-and-raised portion is formed at a mating portion.