JPH10334955A - Laser welding structure of bus bar - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize a bus bar and enhance the density thereof by touching a tub terminal to the pattern part of the bus bar, and welding the pattern part of the bus bar to the tub terminal by a laser beam. SOLUTION: The bent leg part 17b of a tub terminal 17a is put on the pattern part of a bus bar 17 on an insulating plate 17 from above, and a laser beam LB is emitted to the central position of the bent leg part 17b from directly the above. The bent leg part 17b is welded to the pattern part of the bus bar 17 by this emission in the state where the but terminal 17a is directed upwards. Since the bent leg part 17b has a wide surface area, the allowable range of precision error of the emitting position is also extended. Since the laser beam LB is emitted from directly above or directly under, the emitting distance becomes shortest with few obstructions. Further, since the laser beam LB can be easily emitted at the same time from the same direction to a plurality of welding positions, the space and cost can be saved and good mass productivity is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser welding structure most suitable for a bus bar housed in an electric junction box.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG.
A laser beam LB is applied to a crimping portion 3a of a crimping terminal 3 for crimping and connecting the conductor 2 to melt and weld the crimping portion 3a and the conductor 2 (Japanese Patent Application No. 2-1038).
No. 786).

[0003] As shown in FIG. 8 (B), a separate metal projection 5 for replenishing the molten volume is provided on the flat plate-shaped welding metal conductor 4, and a plurality of metal projections are provided below the projection 5. The conductor 2 composed of the element wire 2a is arranged, and the laser beam LB is
Irradiation is performed to fuse and weld the protruding portion 5 together with the conductor 2 (Japanese Patent Laid-Open No. 6-302).
No. 341).

By the way, in an electric junction box used for branch connection of an automobile wire harness or the like to various electric components, the branch connection points are concentrated at one place, and the wiring is rationally and economically connected. With the increase in the density of wire harnesses, various types have been developed according to vehicle types or applications.

[0005] As shown in FIG. 7, the electric connection box is formed by pressing a hoop material 6 with a bus bar 7A using a press die.
To 7C, and each of the bus bars 7A to 7C
The tab terminals 7a and 7b are cut and raised from the pattern portion in the vertical direction, and insulating plates 8A to 8C are interposed between the bus bars 7A to 7C, respectively. And a lower case 9B.

As shown in detail in FIG. 6 of the bus bars 7A to 7C, a tab terminal 7a cut upward from a middle bus bar 7B is connected to an upper insulating plate 8A.
The tab terminals 7a cut upward from the upper bus bar 7A are set so as to have the same height as the tab terminals 7a cut upward from the upper bus bar 7A. The board 8B and the upper insulating plate 8A are penetrated so that the tab terminals 7a cut and raised upward from the upper bus bar 7A are set to have the same height.

Similarly, the tab terminal 7b cut and raised from the middle bus bar 7B extends downward through the lower insulating plate 8C, and the height of the tab terminal 7b cut and raised from the lower bus bar 7C is lowered. The tab terminals 7 which are set so as to be aligned and cut and raised downward from the upper bus bar 7A.
“b” is set so as to penetrate the middle insulating plate 8B and the lower insulating plate 8C, and to have the same height as the tab terminals 7b cut and raised downward from the lower bus bar 7C.

[0010] As shown in FIG. 7, external components such as a fuse 11 and a relay 12 are inserted and connected to the tab terminals 7 a and 7 b via a relay terminal 10 and the like, and externally integrated. The connector on the side is directly inserted and connected.

When the circuit volume in the electric junction box 9 increases, the bus bars 7A (7
B, 7C), the pattern parts of the bus bars 7A to 7C of different levels, and the pattern parts of the bus bars 7A to 7C, and other wiring members (FPC, PC).
B or a conductor such as an electric wire) with a connector.

On the other hand, in recent years, a plurality of electric connection boxes dispersedly mounted in an automobile are integrated into one and arranged in a center cluster or the like, and a wire harness for connecting between the electric connection boxes is provided. Attempts have been made to simplify (line saving).

If the number of circuits in the electric junction box is about 40, a three-layer bus bar laminated structure as described above may be used. However, the number of circuits in the electric junction box is reduced by 80 to 100 due to integration.
When it is increased to the extent, a bus bar laminated structure of 8 to 10 layers is obtained.

With the bus bar laminated structure of eight to ten layers as described above, when the tab terminals are vertically cut from the bus bar pattern portion of each layer, the tab terminals cut and raised upward from the uppermost bus bar are formed. In order to set the height to be the same as the height of the tab terminal cut and raised from the lowermost bus bar, the maximum number of tab terminals is 8 to 1
It is necessary to set the length to penetrate as many as 0 layers of the insulating plate.

[0013]

However, in order to cut a long tab terminal from the bus bar pattern portion, a space for cutting and raising the tab terminal is required in the pattern portion, and this space is a dead space. As a result, the size and the density of the bus bars cannot be reduced, so that there is a problem that the number of stacked bus bars cannot be reduced.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and it is possible to reduce the size and density of a bus bar housed in an electric junction box by utilizing a laser welding technique. It is an object of the present invention to provide a laser welding structure.

[0015]

To solve the above-mentioned problems, a first aspect of the present invention is a laser welding structure for a bus bar housed in an electric junction box, wherein a tab terminal is applied to a pattern portion of the bus bar. Accordingly, the present invention provides a bus bar laser welding structure, wherein the bus bar pattern portion and the tab terminal are welded by a laser beam.

According to the first aspect, the tab terminals are not cut and raised in the vertical direction from the bus bar pattern portion, but the tab terminals are separated, and the separate tab terminals are directed upward or downward to the bus bar pattern portion. By irradiating a laser beam, and melting and welding the tab terminal and the pattern portion, a dead space for cutting and raising the tab terminal in the pattern portion of the bus bar becomes unnecessary.

When the relay terminal and the like are integrally formed with the tab terminal as described above, a separate relay terminal and the like become unnecessary, and the number of parts can be reduced.

A third aspect of the present invention relates to a laser welding structure for a bus bar housed in an electric junction box, wherein a jumper is applied across a pattern portion of the bus bar, and each pattern portion of the bus bar and the jumper are irradiated with a laser beam. An object of the present invention is to provide a laser welding structure for a bus bar, which is characterized by being welded.

According to the third aspect, a separate jumper is applied so as to straddle the pattern portion of the bus bar, and a laser beam is irradiated, and the jumper and the pattern portion are melted and welded. There is no need to connect the pattern sections with a connector.

A fourth aspect of the present invention is a laser welding structure for a bus bar housed in an electric junction box, wherein a conductor such as an FPC, a PCB, or an electric wire is applied to a pattern portion of the bus bar, and the bus bar pattern portion and the conductor are connected to each other. And a laser welding structure for a bus bar, wherein the laser beam is welded by a laser beam.

According to the fourth aspect, a conductor such as an FPC is applied to the pattern portion of the bus bar, and a laser beam is irradiated to melt and weld the conductor and the pattern portion. It is not necessary to connect a conductor such as an FPC with a connector.

[0022]

Embodiments of the present invention will be described below in detail with reference to the drawings. Note that the same components and operations as those of the prior art are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIGS. 1 and 2 show a laser welding structure according to the first embodiment. As shown in FIG. 2, the tab terminals 17 a are not cut and raised in the vertical direction from the pattern portion of the bus bar 17 as in the related art. Integrally formed.

Then, as shown in FIG.
The bent leg 17b of the bus bar 17 on the insulating plate 18
And the laser beam LB is applied to the center of the bent leg 17b from directly above.

By this irradiation, the bent leg portion 17b and the pattern portion of the bus bar 17 are melted and welded with the tab terminal 17a facing upward.

The bent leg 17 of the tab terminal 17a
b is applied to the pattern portion of the bus bar 17 from below,
When the laser beam LB is applied to the center of the bent leg 17b from directly below, the tab terminal 17a faces downward,
The bent leg portion 17b and the pattern portion of the bus bar 17 are melted and welded.

As described above, when the laser beam LB is applied to the central position of the bent leg 17b,
Since the surface area of 7b is large, the tolerance of the accuracy error of the irradiation position is widened. Also, the laser beam L from directly above or directly below
The irradiation with B reduces the number of obstacles and minimizes the irradiation distance, and it is easy to simultaneously irradiate a plurality of welding locations with the laser beam LB from the same direction, so that mass productivity is also good.

It should be noted that the laser beam LB can be viewed from directly above or directly below.
Alternatively, the laser beam LB may be applied to the joint interface between the bus bar 17 and the bent leg portion 17b of the tab terminal 17a for welding from an oblique or right side.

All the tab terminals 17a of the bus bar 17
Are not welded separately, but if necessary, the tab terminals 17a
Can be used in combination with each other.

Further, as shown in FIG.
When the relay terminal 17c is integrally formed with the 7a, a separate relay terminal is not required.

When the bus bar 17 is welded by the conventional resistance welding, a large jig is required for each bus bar in order to sandwich the bus bar between the electrodes. Not suitable for In the case of conventional arc welding, since the gap between the busbar and other circuits is narrow, it is necessary to insulate or widen the gap, so that the density cannot be increased, and it is necessary to ground each circuit to be welded. Therefore, processing man-hours and the like become expensive, which is not suitable for mass production. Furthermore, in ultrasonic welding, partial plating is necessary because welding cannot be performed on a portion of the bus bar that has plating, and the bus bar shape is different one by one, so jigs are required for the number of circuits, so processing man-hours and equipment are required. However, they are expensive and unsuitable for mass production.

On the other hand, in the case of the laser welding according to the present invention, the laser beam LB is not in contact with the above-described resistance welding, arc welding, ultrasonic welding, etc. The bus bar 17 can be welded to
Since the welding seconds per location are short, mass productivity is good, and since the laser beam LB has a small beam diameter, the pitch between the bus bar 17 and the tab terminal 17a can be narrowed to improve the degree of freedom in design wiring. There is an advantage of doing so.

Among various laser weldings, YAG laser welding is non-contact, has a small heat affected layer,
It has low power consumption, is small in size, can be easily used for three-dimensional welding due to the use of optical fibers, and can divide a beam into multiple parts for simultaneous multipoint welding.
It is optimal because the automation is easy and the production cost is significantly reduced.

FIG. 3 shows a laser welding structure according to the second embodiment. The bent legs 19a, 19a of the jumper 19 bent in a substantially Ω-shape are applied over the pattern portion of the bus bar 17 on the insulating plate 18 from above, and the center positions of the bent legs 19a, 19a from directly above. Is irradiated with a laser beam LB. In the second embodiment, the tab terminals 17a are vertically cut from the pattern portion of the bus bar 17 in the vertical direction as in the related art.

By this irradiation, each bent leg 19a,
19a and the pattern portion of the bus bar 17 are melted and welded to each other.

With this laser welding structure, it is not necessary to connect the pattern portions of the bus bar 17 with a connector as in the prior art, so that space and cost can be saved.

FIG. 4 shows a laser welding structure according to the third embodiment. FP is applied to the pattern of the bus bar 17 on the insulating plate 18.
The conductors 20a,... Of the C, PCB or electric wires 20 are applied from above, respectively, and the laser beam LB is applied to the central position of each conductor 20a,.

By this irradiation, the conductors 20a,... And the pattern portion of the bus bar 17 are melted and welded.

With this laser structure, as in the prior art,
The conductor 20a of the FPC or the like 20 is provided on the pattern portion of the bus bar 17.
It is no longer necessary to connect the devices with a connector, so that space and cost can be saved.

[0040]

As is clear from the above description, the laser welding structure of the bus bar of the present invention irradiates a laser beam by applying a separate tab terminal to the pattern portion of the bus bar. The parts are melted and welded.

Therefore, no dead space is required in the pattern portion of the bus bar to cut and raise the tab terminals. By increasing the pattern portion in this dead space, the size and density of the bus bar can be reduced. The number of stacked busbars can be reduced. As a result, the number of busbar layers is reduced, the number of press dies for punching the busbars from the hoop material and cutting the tab terminals is reduced, so that the die cost is reduced and the electrical connection box itself is reduced due to the reduced number of busbar layers. It can be downsized.

Further, by forming the relay terminal and the like integrally with the tab terminal as in the second aspect, a separate relay terminal and the like become unnecessary, so that the number of parts can be reduced.

Further, when a separate jumper is applied so as to straddle the pattern portion of the bus bar and a laser beam is applied thereto, and the jumper and the pattern portion are melted and welded, the pattern of the bus bar is obtained. Since there is no need to connect the parts with a connector, space and cost can be saved.

Furthermore, when a conductor such as an FPC is applied to each pattern portion of the bus bar and irradiated with a laser beam to melt and weld the conductor and the pattern portion, the pattern portion of the bus bar is formed. In addition, since it is not necessary to connect a conductor such as an FPC with a connector, it is possible to save space and cost.

[Brief description of the drawings]

FIG. 1 is a laser welding structure according to a first embodiment of the present invention, in which (A) is a perspective view in which a tab terminal is laser-welded to a bus bar, and (B) is a side sectional view.

FIG. 2 is an exploded perspective view before a tab terminal is laser-welded to a bus bar.

FIG. 3 is a perspective view of a laser welding structure according to a second embodiment, in which a jumper is laser-welded to a bus bar.

FIG. 4 is a perspective view of a laser welding structure according to a third embodiment, in which a conductor such as an FPC is laser-welded to a bus bar.

FIG. 5 is a perspective view of a tab terminal formed integrally with a relay terminal.

FIG. 6 is a perspective view of a conventional bus bar.

FIG. 7 is an exploded perspective view of a conventional bus bar processing and assembling procedure.

FIGS. 8A and 8B are perspective views of a conventional laser welding structure for a crimp terminal and the like.

[Explanation of symbols]

 9 Electrical connection box 17 Bus bar 17a Tab terminal 17b Bending leg 17c Relay terminal 18 Insulating plate 19 Jumper 20 FPC etc. 20a Conductor LB Laser beam a Welding

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Atsuhiko Fujii 1-7-10 Kikuzumi, Minami-ku, Nagoya City, Aichi Prefecture Inside Harness Research Institute, Inc. (72) Inventor Yoshifumi Saka 1-Kikuzumi, Minami-ku, Nagoya City, Aichi Prefecture 7-10 Harness Research Institute, Inc. (72) Inventor Atsuhiro Togawa 1-10 Kikuzumi, Minami-ku, Nagoya City, Aichi Prefecture Harness Research Institute, Inc.

Claims (4)

[Claims] 1. A laser welding structure for a bus bar housed in an electric connection box, wherein a tab terminal is applied to a pattern portion of the bus bar, and the bus bar pattern portion and the tab terminal are welded by a laser beam. Features a laser welding structure for bus bars. 2. The laser welding structure for a bus bar according to claim 1, wherein a relay terminal or the like is integrally formed with the tab terminal. 3. A laser welding structure for a bus bar housed in an electric connection box, wherein a jumper is applied across a pattern portion of the bus bar.
A laser welding structure for a bus bar, wherein each pattern portion of the bus bar and a jumper are welded by a laser beam. 4. A laser welding structure for a bus bar housed in an electric junction box, wherein a conductor such as an FPC, a PCB, or an electric wire is applied to a pattern portion of the bus bar, and the bus bar pattern portion and the conductor are welded by a laser beam. A laser welding structure for a bus bar, characterized in that: