JPH06113428A - Method of fixing bus bar - Google Patents

Abstract

PURPOSE:To easily and surely fix a bus bar to an insulating board by a method wherein a metal chip for fixation use is inserted into, and molded to, the insulating board in advance and the bus bar is laser-welded to the metal chip for fixation use. CONSTITUTION:A bus bar 12 is inserted between one pair of ribs 13a, 13b, and it is positioned in such a way that the bottom face of the bus bar 12 is brought into contact with a metal chip 14. In this state, the bus bar 12 is irradiated with a laser by a laser irradiation apparatus 15 from the upper part of the bus bar 12. As a result, the bonding face of the bus bar 12 to the metal chip 14 is melted, and the bus bar 12 is welded to the metal chip 14. Since the metal chip 14 is fixed to an insulating board 11, the bus bar 12 is fixed to the insulating board 11 via the metal chip 14. Thereby, the bus bar 12 can be fixed to the insulating board 11 easily and surely.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a busbar fixing method suitable for application to an electric junction box or the like used for connecting a wire harness.

[0002]

2. Description of the Related Art An electric junction box (hereinafter simply referred to as "J / B") generally contains a circuit mainly having a joint absorbing function of a wire harness in a case, and has a large number of fuses and relays on the outer surface of the case. It is configured by mounting an electric component and a connector receiving portion. And a plurality of J
By disposing / B at appropriate positions in the vehicle, the wiring of the wire harness is facilitated and the wiring form thereof is simplified.

FIG. 17 shows an example of such J / B,
Wiring board assemblies e ₁ and e _{2 each} consisting of a plurality of bus bars C and an insulating substrate d are stacked and housed in the upper case a and the lower case b, and tabs formed upright above or below the bus bar c ( The connection terminal f is projected into the connector receiving portion g ₁ and the fuse inserting portion g ₂ provided in the case, and is connected to the terminal connector h of the wire harness W, the fuse i, the relay j, and the circuit breaker k. It has a structure that allows it.
In addition, 1 is a female-female relay terminal used for connecting the tab f to an external fuse terminal, and m is a tab insertion hole.

In the J / B structure, the bus bar is fixed to an insulating substrate for wiring such as synthetic resin, and the fixing structure is disclosed in JP-A-55-144710 and Japanese Utility Model Laid-Open No.
Although disclosed in Japanese Patent Application Laid-Open No. 8-7772, its outline will be described below. That is, in the structure shown in FIGS. 11 and 12, the bus bar 3 is inserted into the locking hole 2 formed in the insulating substrate 1.
The locking claw 4 formed on the above is press-fitted. Although the tip of the locking claw 4 is stopped in the locking hole 2 in the illustrated configuration, there is also a structure in which the tip of the locking claw 4 is projected from the locking hole 2 to the back side of the insulating substrate 1.

Further, in the structure shown in FIGS. 13 and 14, while the projection 5 is formed on the insulating substrate 1, the projection 5 is formed.
The engaging hole 6 formed in the bus bar 3 is inserted through the inner wall of the bus bar 3, and the tip of the projection 5 is further crushed to be caulked with resin. Further, in the structure shown in FIGS. 15 and 16, a pair of protrusions 5a and 5b are formed on the insulating substrate 1, the bus bar 3 is sandwiched between them, and the tips of the protrusions 5a and 5b are crushed and caulked with resin. It is a thing.

[0006]

However, in recent years, one of the technical trends of J / B is high density, and the number of bus bars tends to increase. However, in the structure shown in FIG. 11 and FIG. 12, the protrusion 4 is one of the factors that obstruct the circuit arrangement by interfering with the circuit arrangement. In the structure shown in FIGS. 13 to 16, the caulking projections 5 and 5 are used.
In addition to the fact that a and 5b were easily broken, there were many variations in the caulking of the resin, and these were combined to lack reliability. Further, in order to securely fix the bus bar 3 by caulking the resin, it is necessary to provide a large number of caulking projections.

Further, in the structure shown in FIGS. 13 and 14, since the locking hole 6 is formed in the buzz bar 3, the cross-sectional area is reduced, which electrically contributes to the increase in resistance. Therefore, when the number of the locking holes 6 is increased, an undesired phenomenon such as a decrease in current amount and heat generation occurs. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a busbar fixing method for easily and surely fixing a busbar to an insulating substrate.

[0008]

The above object of the present invention is to fix a fixing metal chip in advance at a desired position of a wiring path set on an insulating substrate, and dispose a bus bar on the fixing metal chip. Then, the fixing metal chip and the bus bar are laser-welded together to achieve a bus bar fixing method.

[0009]

That is, since the bus bar is laser-welded to the fixing metal chip which is insert-molded in advance on the insulating substrate, the bus bar is integrated with the fixing metal chip at a key point. Therefore, it is not necessary to provide a locking projection on the bus bar, and a projection for caulking the resin is not required, so that the density can be increased, the reliability can be improved, and the fixing work efficiency can be improved.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described in detail below with reference to FIGS. Needless to say, the present invention is not limited to this embodiment. Figure 1 is J
/ B is a perspective view showing an appearance of a main part, FIG. 2 is a cross-sectional view showing insert molding of a fixing metal chip, and FIGS. 3 to 5 are process diagrams showing a laser welding work procedure. In describing the embodiments, the structure of the main part of the J / B will be described with reference to FIGS. 1 and 2, and then laser welding will be described with reference to FIGS.

On the insulating substrate 11, a pair of ribs 13a and 13b forming a disposition path of the bus bar 12 are integrally formed, and a fixing metal chip 14 is insert-molded at a desired position of the disposition path. . The ribs 13a and 13b are for preventing a leak from the adjacent bus bar, and the bus bar 12 is preferably a metal such as brass that is easy to process and has excellent conductivity.

The fixing metal chip 14 (hereinafter, simply referred to as a metal chip) has a circular plane shape and the thickness thereof is the insulating substrate 1.
The thickness is set to be smaller than the thickness of 1 and the overall shape is, for example, a coin shape. Since the metal chip 14 is insert-molded at a desired position when the insulating substrate 11 is molded, the metal chip 14 is fixed at a desired position of the insulating substrate 11 so that the metal chip 14 does not come out.

Although illustration of the entire J / B is omitted, the J / B may be constructed by laminating an appropriate number of insulating substrates 11 shown in FIG. 1, and the insulating substrate is as described above. Relays, fuses, connection terminals, etc. are provided as necessary. Next, a method of fixing the bus bar 12 will be described with reference to FIGS. When the bus bar 12 is fixed, the bus bar 12 is inserted between the pair of ribs 13a and 13b as shown by the arrow in FIG. 3, and the bottom surface of the bus bar 12 contacts the metal chip 14 as shown in FIG. Position. In this state, the laser is applied to the bus bar 12 from above the bus bar 14 by the laser irradiation device 15.

As a result, the bus bar 12 and the metal chip 14
As shown in FIG.
Are welded to the metal tip 14. Since the metal chip 14 is fixed to the insulating substrate 11, the bus bar 12
Will also be fixed to the insulating substrate 11 via the metal chip 14. The fixing of the bus bar 12 is automatically and sequentially performed at the insert molding position of the metal tip 14 by NC control, for example. Therefore, the bus bar 12 is automatically and efficiently and surely fixed to the predetermined position of the insulating substrate 11.

Next, referring to FIGS. 6 to 9, the second embodiment of the present invention will be described.
An example will be described. The feature of this embodiment resides in that the metal chip is provided with a projection and the bus bar is provided with an insertion hole. Therefore, the same members as those described above are designated by the same reference numerals and the description thereof will be omitted. That is, as shown in FIGS. 6 and 7, the metal chip 21 in the present embodiment is integrally formed with the planar circular protrusion 22 in the central portion. On the other hand, an insertion hole 24 is formed in the bus bar 23 at a position corresponding to the protrusion 22, and when the bus bar 23 is positioned between the pair of ribs 13a and 13b, the protrusion 22 is inserted into the insertion hole 24. There is.

Next, referring to FIGS. 8 to 10, the bus bar 2 will be described.
The fixing method of No. 3 will be described. When the bus bar 23 is fixed, a pair of ribs 13a and 13b are provided as shown by arrows in FIG.
The bus bar 23 is inserted in between, and the projection 22 is inserted into the insertion hole 24 and positioned. As shown in FIG. 9, the bus bar 23 has a metal chip 21 at the bottom around the insertion hole 24.
The laser irradiation device 1 is placed on top of this
A laser is applied to the protrusion 22 by 5.

As a result, the contact surface between the projection 22 and the insertion hole 24 or the opposing surface is melted, and the bus bar 23 is welded to the metal chip 21. Since the metal chip 21 is fixed to the insulating substrate 11, the bus bar 23 is also fixed to the insulating substrate 11 via the metal chip 21. The fixing of the bus bar 23 is automatically and sequentially performed at the insert molding position of the metal tip 21 by NC control, for example. Therefore, the bus bar 23 is automatically, efficiently and surely fixed to the predetermined position of the insulating substrate 11.

Since the insertion hole 24 is formed in the bus bar 23, the cross-sectional area at the position of the hole is reduced and the electric resistance is increased in the conventional structure. However, in this embodiment, when the bus bar 23 is fixed, the insertion hole 24 is blocked by the projection 22 and welded together, so that the insertion hole 24 does not increase the electric resistance. Therefore, it is possible to prevent the decrease in the amount of current and the generation of heat due to the increase in resistance.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above, and various modifications can be made. For example, the planar shape of the metal chips 14 and 21 is not limited to a circular shape, and a metal piece can be cut into a rectangular shape and applied.
Further, in each of the above embodiments, the metal chips 14, 2
1 has been described as being insert-molded at a desired position when the insulating substrate 11 is molded, the present invention is not limited to such a configuration, and for example, a metal chip is press-fitted and fixed to the insulating substrate. It can also be provided.

[0020]

As described above, in the method of fixing a bus bar according to the present invention, a fixing metal chip is insert-molded in advance on an insulating substrate, and the bus bar is laser-welded to the fixing metal chip. Therefore, the bus bar is securely fixed to the insulating substrate through the fixing metal chip at a key portion. Therefore, there is no peeling of the bus bar from the insulating substrate, the reliability is significantly improved, and the structure of the insulating substrate is simplified, so that the thickness can be reduced.
It is possible to increase the density of an electrical junction box or the like using this insulating substrate.

[Brief description of drawings]

FIG. 1 is a perspective view of an essential part of an insulating substrate showing a first embodiment of the present invention.

FIG. 2 is a sectional view of an essential part showing the structure of an insulating substrate.

FIG. 3 is a cross-sectional view showing a welding process of a bus bar.

FIG. 4 is a cross-sectional view showing laser welding of a bus bar.

FIG. 5 is a cross-sectional view showing a welded state of a bus bar.

FIG. 6 is a perspective view of a main part of an insulating substrate showing a second embodiment of the present invention.

FIG. 7 is a sectional view of an essential part showing the structure of an insulating substrate.

FIG. 8 is a sectional view showing a step of welding a bus bar.

FIG. 9 is a cross-sectional view showing laser welding of a bus bar.

FIG. 10 is a cross-sectional view showing a welded state of a bus bar.

FIG. 11 is a perspective view showing a first example of a conventional fixing structure for a bus bar.

FIG. 12 is a sectional view of an essential part showing a conventional fixing structure for a bus bar.

FIG. 13 is a cross-sectional view showing a second example of a conventional bus bar fixing structure.

FIG. 14 is a plan view showing a conventional fixing structure for a bus bar.

FIG. 15 is a sectional view showing a third example of a conventional bus bar fixing structure.

FIG. 16 is a plan view showing a conventional fixing structure for a bus bar.

FIG. 17 is an exploded perspective view illustrating a conventional electric junction box.

[Explanation of symbols]

 11 Insulating Substrate 12, 23 Bus Bar 13a, 13b Rib 14, 21 Fixing Metal Chip 15 Laser Irradiator 22 Protrusion 24 Insertion Hole

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[Procedure amendment]

[Submission date] February 18, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction content]

[0004] According the configuration of J / B, the bus bar is a synthetic resin is fixed to the wiring insulating substrate such as, the fixing structure Sho 55-144710 discloses and real public Akira 5
Although disclosed in Japanese Patent Application Laid-Open No. 8-7772, its outline will be described below. That is, in the structure shown in FIGS. 11 and 12, the bus bar 3 is inserted into the locking hole 2 formed in the insulating substrate 1.
The locking claw 4 formed on the above is press-fitted. Although the tip of the locking claw 4 is stopped in the locking hole 2 in the illustrated configuration, there is also a structure in which the tip of the locking claw 4 is projected from the locking hole 2 to the back side of the insulating substrate 1.

Claims (1)

[Claims] 1. A fixing metal chip is previously fixed at a desired position of a wiring path set on an insulating substrate, a bus bar is arranged on the fixing metal chip, and then the fixing metal chip and the bus bar are arranged. A method for fixing a bus bar, which is characterized by laser welding.