JP2503316B2 - Bus bar wiring board - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a busbar wiring board constituting an internal circuit of an electric connection box used for connecting an electric circuit of an automobile and a method of forming the busbar wiring board.

[0002]

2. Description of the Related Art FIG. 4 shows an example of a conventional electrical junction box.
A busbar wiring board 6 including a plurality of busbars 4 and an insulating substrate 5 is stacked and accommodated in a box body 3 including an upper case 1 and a lower case 2. Each bus bar has an upward or downward tab 7, and these groups of tabs 7 are led out to the connector insertion portion 8 of the upper case 1 (or the lower case 2), the fuse connector 9 and the like as connector terminals.

The bus bar group 4 is conventionally made of the same material (plate thickness,
A conductive metal plate having the same conductivity and the same material) is punched and formed in a band shape having a desired pattern.

The width of each bus bar of each layer is determined from the value obtained by determining the cross-sectional area from the value of the current applied and the electrical conductivity of the material. At this time, the thickness of the bus bar is determined by the plate thickness required for the tab 7 in terms of strength, and the minimum width of the bus bar is determined after punching the material.

On the other hand, the number of bus bars arranged on one insulating substrate 5 is limited due to the number of circuits required for the electrical junction box and the rising position of the tab 7. Occurs. Therefore, the conventional bus bar is often formed by punching the same material wider than the minimum bus bar width.

[0006]

Generally, a material used for punching a bus bar has a low conductivity and a low material cost. However, in the conventional method of punching and forming the busbars from the same material, an excessive quality (a material with high conductivity and high cost) is formed due to the punching process of the busbars or the arrangement of the busbars.
Therefore, it was regarded as a problem in terms of resource saving and material cost.

The present invention has been made by paying attention to the above-mentioned points, and it is possible to reduce the waste of materials while satisfying the heat radiation safety.
An object is to provide a bus bar wiring board that can reduce costs.

[0008]

In order to achieve the above object, the busbar wiring board of the present invention has a plurality of busbars having a desired pattern arranged on an insulating substrate as described in claim 1. In this busbar wiring board, the plurality of busbars are selectively punched from two or more kinds of conductive metal plates having different conductivity.

[0009]

According to the present invention, with respect to each bus bar constituting the bus bar wiring board of each layer, the bus bar is determined by the energizing current value from the heat dissipation property, that is, the pattern shape of the bus bar itself, the arrangement density of the bus bars, the stacking position, and the like. At this time, two or more kinds of materials having different electric conductivity can be arbitrarily selected and formed.

Therefore, the bus bar can be formed of a material suitable for the required quality such as the value of current flowing through the bus bar and the heat dissipation property, and the waste of the high quality of conventional materials can be eliminated.
The material cost can be reduced.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, reference numerals 10 ₁ and 10 ₂ are
First and second layer busbar wiring boards are shown, each of which is formed by disposing a plurality of busbars 12 having tabs 13 on an insulating substrate 11. These busbars 12 have a conductivity of 30%,
65%, 85% three different materials a, b, c
It is stamped and formed. In addition, 11a shows a bus bar arrangement groove, and 11b shows a tab insertion hole.

That is, in the bus bar indicated by reference numeral 12a ₁ in the figure, a is a material, and the subscript number ₁ has a current value of 1
A, the number in parentheses (0.9 → 2.0) is 0.9 on the left side
Indicates the minimum busbar width of 0.9 mm, and the number 2.0 on the right side indicates the actual busbar width of 2.0 mm. Similarly, 12b ₁₂ (6.9 → 6.
9) is material b, current value 12A, minimum busbar width 6.
9 mm, showing that the actual busbar width is 6.9 mm.

The low-current busbars 12a ₁ and 12a ₂ having a current value of 1A and 2A ensure a busbar width corresponding to the current value even if a material having the lowest electrical conductivity is used, and the strength of the busbar is increased. , Can be increased.

As described above, by changing the punching material of the bus bar according to the value of the energized current, it is possible to save the material waste (excessive quality), reduce the material cost, and improve the punching workability of the bus bar. it can.

The above is the first and second layer bus bar wiring board 10.
₁ and 10 ₂ bus bars 12 (12a ₁ , 12a ₂ ...)
Although it is formed by punching from different materials individually,
As shown in FIGS. 2 and 3, it is possible to use materials having different electric conductivity for each layer and to form the busbars in the same layer by punching from the same material at once.

That is, the busbar wiring boards 6 ₁ ′, 6 ₂ ′, and 6 ₃ ′ of the first, second, and third layers shown in FIG. 3 are all stamped and formed from the same material c (conductivity 85%). It is composed of a plurality of bus bars 4 (4c ₁ , 4c ₂ , 4c ₁₂ ...).

FIG. 2 shows a first and a circuit having the same circuit configuration as that of FIG.
Bus bar wiring boards 10 ₁ ′, 10 ₂ ′, 1 of the second and third layers
0 ₃ ′, and the group of bus bars 12 in each layer are formed by punching the materials c, b, and a collectively.

The first layer bus bars 12c ₁₂ , 12c ₂₀ ...
Is a bus bar 4c _12, 4c ₂₀ ... of the same material of FIG. 3 have the same bus bar width, the same as conventional. The second layer bus bars 12b ₁ , 12b ₂ , 12b ₁₂ ... Are stamped and formed from the material b, and the bus bars 4c ₁ , 4c ₂ , 4c _{12 of} FIG.
Compared with ..., the busbar width is wider and easier to process, and the minimum busbar width and the actual busbar width are almost equal. The same applies to the bus bar 12a ₁ , 12a ₂ ... Group of the third layer.

As described above, in place of the conventional high-quality material c, the materials b and a having low electric conductivity are used for the second and third layer busbar wiring boards 10 ₂ ′ and 10 ₃ ′. It can be seen that the required bus bar width is secured.

[0020]

As described above, according to the present invention,
When forming the busbar wiring board that constitutes the internal circuit of the electrical junction box, waste of the material used for punching the busbar can be eliminated, cost can be reduced, and punching workability is also improved.

[Brief description of drawings]

FIG. 1 is a perspective view of a bus bar wiring board showing an embodiment of the present invention.

FIG. 2 is a perspective view of a bus bar wiring board showing another embodiment of the present invention.

FIG. 3 is a perspective view of a conventional bus bar wiring board having the same circuit configuration as that of FIG.

FIG. 4 is a partially cutaway perspective view showing a conventional electric junction box.

[Explanation of symbols]

10 ₁ , 10 ₂ Busbar Wiring Board 10 ₁ ′ -10 ₃ ′ Busbar Wiring Board 11 Insulating Substrate 12, 12 a ₁ ~ Busbar 13 Tabs a, b, c Conductive Metal Plates with Different Conductivities

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Shin Nakayama 252 Kawashimada, Gotemba City, Shizuoka Prefecture Yazaki Parts Co., Ltd. (56) Reference JP 56-67981 (JP, A) , U) Showa 63-77272 (JP, U)

Claims (1)

(57) [Claims] 1. A busbar wiring board comprising a plurality of busbars having a desired pattern arranged on an insulating substrate, wherein the plurality of busbars are selectively punched from two or more kinds of conductive metal plates having different conductivity. Busbar wiring board characterized by being.