JP3508681B2 - Connection structure of internal circuit of junction box - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connection structure for an internal circuit of a shunt box connected to an automobile wire harness.

[0002]

2. Description of the Related Art Recently, with the rapid increase in electrical components mounted on automobiles, the number of circuits contained in automobile electrical junction boxes, especially junction boxes, has increased rapidly to form branch circuits with high density. Moreover, the number of parts is extremely large, and the number of assembling steps is also very large.

In the junction box 1 shown in FIG. 6 among the electric connection boxes for automobiles, bus bars 5A to 5D are laminated between upper case 2 and lower case 3 with insulating plates 4A to 4E interposed. Further, the insulating plate 15 provided with the wire guide grooves at both upper and lower ends is arranged, and the insulating plate 1
The wires 5A and 6B are wired and housed on the housing 5, and the connector housing, the relay housing, and the relay 8, which is fitted in the fuse housing, provided in the upper case 2 and the lower housing 3, the fuse, and the terminal of the connector are connected to the bus bar. Tab 7 protruding from
The electric wires 6A and 6B are press-fitted to a press-contact terminal (not shown), and the press-connect terminals are connected to terminals of a connector, a relay, and a fuse.

[0004]

As described above, the internal circuit of the junction box is mainly of the bus bar type, but there are also cases where both the electric wire and the pressure welding method in which the pressure welding terminal is connected to the electric wire are used together. In any of the above methods, the busbars to be stacked or the connection between the busbar and the electric wire are provided with tabs on the busbar, and the electric wires are connected with pressure contact terminals having tabs, and these tabs are connected to both ends by females. It is necessary to connect via a relay terminal having a terminal portion. As described above, there is a problem that the relay box is required, the assembling work is troublesome, the space for installing the relay terminal is required, and the junction box becomes large.

Further, in the case of the bus bar system, if the number of circuits to be taken into the junction box is increased, the number of wiring circuits per layer is reduced due to the relationship of the positions where the tabs are provided and the positions where the relay terminals are arranged. There is a problem that the number of layers increases and the junction box becomes large and complicated. Also, many busbars are required,
Since it has to be formed from a mold according to the circuit change, the cost is very high. In addition, an insulating plate must be interposed between the bus bars, which increases the number of parts and the number of assembly steps.

The present invention has been made in view of the above problems, and it is an object of the present invention to connect internal circuits of a junction box to each other without using a relay terminal.

[0007]

In order to solve the above problems, the present invention comprises a circuit body housed in a junction box, wherein the circuit body is a first injection molding (1) of an insulating resin by a mold. The substrate part is molded with different colors, and this substrate part is moved into another mold and metal fiber or low melting point alloy is dispersed in the thermoplastic resin to inject a highly conductive resin that is joined in a network form. Molding (second color), and in these two steps, the substrate part made of insulating resin is embedded with the surface of the conductive part made of highly conductive resin exposed, and integrally molded into a flat plate shape. Is formed in a desired circuit, and the junction boxes are formed by stacking the above-mentioned circuit bodies on top of each other and directly contacting the required circuits made of the above-mentioned conductive parts formed on the upper and lower circuit bodies by surface contact. Internal circuit connection It provides a structure.

More specifically, one surface of the circuit body having a substantially flat plate shape is provided with a circuit formed of the conductive portion in a planar shape, and the other surface is an insulating surface formed of an insulating resin layer. The portion is formed into a three-dimensional shape and exposed on the other surface of the insulating surface to form a connection portion, and the connection portion is brought into surface contact with a circuit provided on one surface of the circuit body to be laminated to electrically connect.

Alternatively, a convex portion or a concave portion is provided at a connecting portion of the above-mentioned vertically laminated circuit bodies, and the concave portion and the convex portion are fitted to each other, or the tip surfaces of the convex portions are in contact with each other.

As described above, according to the present invention, by using a new circuit body different from the bus bar, the electric wire and the pressure contact terminal, or the FPC used so far, as the internal circuit body accommodated in the electric connection box, It is possible to stack and arrange the circuit bodies without interposing an insulating plate, and it is possible to achieve electrical connection by bringing the circuits of the adjacent circuit bodies into surface contact with each other. As a result, there is no need for a relay terminal,
In addition, since it is not necessary to interpose an insulating plate, it is possible to reduce the number of parts, and at the same time, it is possible to reduce the size and weight of the junction box as the space is reduced.

As described above, in the circuit body using the highly conductive resin as the conductive portion, the first injection molding (first color) by the mold is performed with the insulating resin to mold the substrate portion,
This substrate part is another mold and the second injection molding (second color)
Is performed with a highly conductive resin to form a conductive portion, and a circuit body in which the substrate portion and the conductive portion are integrated into a flat plate shape is formed in two steps.

Since the conductive portion is formed by injection molding as described above, it is possible to mold the conductive portion into an arbitrary shape. Therefore, the conductive portion can be provided three-dimensionally inside the substrate portion, and one surface side can be provided. It is possible to provide a conductive portion having a required circuit pattern and to form a connection portion which is continuous with the conductive portion and exposed on the other surface side. Further, the convex portion and the concave portion for connection can be formed in advance in the circuit portion.

The conductive resin forming the above circuit pattern is disclosed in JP-A-10-237331 and JP-A-11-342.
As disclosed in No. 522, in a thermoplastic resin,
It is composed of a mixture of metal fibers made of copper, nickel, iron or the like, and a conductive resin composition in which lead-free solder (low melting point solder) and a low melting point alloy such as Cu powder are dispersed.

Examples of the thermoplastic resin to which the conductive metal fibers are mixed include propylene, polyethylene, polystyrene, acrylonitrile butadiene styrene resin, modified polyphenylene oxide resin, polybutylene terephthalate resin, polyethylene terephthalate resin, polyamide resin, and aromatic resin. Polyamide resin, polyphenylene sulfide resin, liquid crystal polymer, polyetherimide,
Resins such as polybenzimidazole, polyether ether ketone, and polyether sulfone can be used alone or in a blend, and acrylonitrile / butadiene / styrene resin and polybutylene terephthalate resin are particularly preferably used.

As the low melting point alloy which is mixed with the thermoplastic resin and dispersed and bonded in a network form, an alloy having a melting point of 100 ° C. or higher, preferably 200 ° C. or higher, which melts during injection molding is used. Sn-Pb System, Sn-Ag
-Pb system, Sn-Bi system, Sn-Bi-In system, Bi-
Pb type, Bi-Sn type, Sn-Cu type, Sn-Cu-N
i-P system, Sn-Ag system, Sn-Bi-Pb system, Sn-
In-based ones are mentioned.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an exploded perspective view of a junction box 10 connected to an automobile wire harness.
1 is an upper case, 12 is a lower case, 13 (13
A, 13B) is a circuit body, 14 is a bus bar, 15 is a single core wire for pressure contact, 16 is a pressure contact terminal, and 17 is a conductive pin. Although not shown, an insulating plate is interposed between the circuit body 13A and the bus bar 14 which are adjacently stacked.

As described above, the junction box 1
In No. 0, the internal circuit including the bus bar 14, the single core wire 15 and the pressure contact terminal 16 is used together with the circuit body 13, but the internal circuit may be configured by only the circuit body 13. Further, although the circuit body 13 has two layers in the drawing, it goes without saying that the circuit body 13 may have two or more layers.

The circuit body 13 (13A, 13B) is embedded in a substrate portion 20 made of an insulating resin with a surface of a conductive portion 21 (indicated by diagonal lines in the drawing) made of a highly conductive resin exposed. And is integrally molded into a flat plate shape.

The surface 21a of the conductive portion 21 is the substrate portion 2
A circuit portion C is formed so as to be flush with the upper surface 20a of the substrate 0 in a circuit pattern. Thus, the circuit C having the required shape is provided on the upper surface X side of the circuit body 13, while the lower surface Y side is the insulating surface 20b made of the insulating resin layer.

Further, depending on the circuit configuration, FIG.
The cross-sectional shapes shown in (B) and (C) are formed. Figure 2
In (A), one end of the circuit C formed on the upper surface X of the circuit body 13 is provided three-dimensionally and exposed at a part of the lower surface Y serving as an insulating surface to form the connection portion 18A. In FIG. 2 (B),
The circuit C is formed only on the upper surface X side of the circuit body 13. In FIG. 2C, both ends of the circuit C formed on the upper surface X of the circuit body 13 are provided three-dimensionally and exposed on the lower surface Y serving as an insulating surface to form the connection portions 18B and 18C. The cross-sectional shape is not limited to the above, and the connecting portion has a required shape according to the circuit design.

The method of manufacturing the circuit body 13 will be described with reference to FIG.
As shown in (A), an insulating resin is injected into the cavities of the upper and lower molds 30A and 30B, and a primary molded product including only the substrate portion 20 is injection molded. In this state, the conductive portion 21 is not provided on the substrate portion 20 and a part that penetrates through is formed. Then, as shown in FIG. 3 (B), the upper die 30A is changed to another die 30C, and the lower die 30B is formed.
Cavity 32 is formed between the substrate portion 20 and the mold 30C by joining and clamping. The cavity 32 has a portion 32a between the upper and lower molds 30C and 30B where the above-mentioned connecting portion is formed. As shown in FIG. 3C, a highly conductive resin is injected into the cavity 32 to injection-mold the conductive portion 21. As a result, the circuit body 13 including the conductive portion 21 having a desired circuit shape is integrally formed on the surface of the substrate portion 20.
The conductive portion 21 is integrally provided with a connecting portion 18 exposed on the lower surface.

As shown in FIG. 1, the circuit body 13 is stacked and housed inside a case composed of an upper case 11 and a lower case 12, and is used as an internal circuit of a junction box.

In the laminated circuit bodies 13A and 13B, as shown in FIG. 4A, the lower surface Y serving as an insulating surface of the upper layer circuit body 13A is provided with the circuit C of the lower layer circuit body 13B. Since it contacts the upper surface X, it is not necessary to interpose an insulating plate. Further, the connecting portion 18A exposed on the lower surface Y of the upper layer circuit body 13A has the circuit C on the upper surface X of the lower layer circuit body 13B.
It is in surface contact with and electrically connected to each other, so that circuits of different circuit bodies can be directly connected to each other. Further, as shown in FIG. 4B, the connection portions 18B and 18C exposed on the lower surface Y of the upper layer circuit body 13A are in surface contact with the circuits C1 and C2 on the upper surface X of the lower layer circuit body 13B, respectively. Electrically connected.

The conductive portion 21 of the circuit 13 and the connector housing portion 11 provided in the upper case 11 and the lower case 12
The terminals connected to the electric wire terminals accommodated in a and 12 a, and the terminals of the relay and the fuse are connected via the conductive pin 17.

The connection between the circuits of the laminated circuit bodies is not limited to the above embodiment, and as shown in FIG. 5 (A), the upper layer circuit body 13A is provided with the concave portion 18a in the connecting portion 18,
You may provide the convex part 18b in the connection part of the circuit body 13B of a lower layer, and may electrically connect it by uneven | corrugated fitting. Further, as shown in FIG. 5 (B), convex portions 18b may be provided on the connecting portions 18 of the upper and lower circuit bodies 13A and 13B, and the tip surfaces of these convex portions 18b may be brought into contact with each other for electrical connection. Further, as shown in FIG. 5 (C), the upper layer circuit body 13A is provided with a convex portion 18b at a pair of connection portions at a close position, and the lower layer circuit body 13B is also provided with a convex portion 18b. The lower layer convex portion 18b is inserted between the upper layer convex portions 18b to connect two circuits of the upper layer circuit body 13A to one circuit of the lower layer circuit body 13B.

[0026]

As is clear from the above description, according to the present invention, the circuit body used as the internal circuit of the junction box is integrally formed with the conductive portion made of the highly conductive resin and the substrate made of the insulating resin. Therefore, when the circuit bodies are laminated, the adjacent circuit bodies can be directly laminated without interposing the insulating plate, and the conductive portion forming the circuit between the adjacent circuit bodies can be directly formed. The circuit connection can be made by making surface contact.

As described above, since the insulating plate and the relay terminal are not required between the circuit bodies, it is possible to reduce the number of parts and the number of assembling steps, and the cost can be reduced accordingly. . At the same time, it is possible to reduce the size and weight of the junction box by reducing the space.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a junction box according to an embodiment of the present invention.

2A, 2B, and 2C are cross-sectional views of a circuit body.

3A, 3B, and 3C are cross-sectional views showing a manufacturing process of a circuit body, and FIG. 3D is a cross-sectional view in a direction orthogonal to the cross-section.

4A and 4B are cross-sectional views showing a state in which circuits of circuit bodies to be stacked are connected.

5 (A), (B), and (C) are cross-sectional views showing a modified example of the connection structure of the circuit body.

FIG. 6 is an exploded perspective view of a conventional junction box.

[Explanation of symbols]

10 junction box 11 upper case 12 lower case 13 (13A, 13B) Circuit body 14 Busbar 18 Connection 20 board part 21 Conductive part C circuit

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Nobufumi Kobayashi No. 14 Nishisuehiro-cho, Yokkaichi-shi, Mie Sumitomo Wiring Systems, Ltd. (56) Reference JP-A-2-139216 (JP, A) JP-A 9-92987 (JP, A) JP-A-11-126972 (JP, A) JP-A-53-100468 (JP, A) JP-A-11-261182 (JP, A) JP-A-7-170077 (JP, A) A) Japanese Unexamined Patent Publication No. 11-46064 (JP, A) Japanese Unexamined Patent Publication No. 2-130892 (JP, A) Japanese Unexamined Patent Publication No. 3-104614 (JP, A) Areas (Int.Cl. ⁷ , DB name) H02G 3/16 B60R 16/02 H05K 5/00

Claims (3)

(57) [Claims] 1. A case of being housed in a junction box
A circuit body is provided, and the circuit body is formed by a first injection molding of insulating resin by a mold.
The board part is molded in the shape (first color), and this board part is
Move it into the mold and add metal fibers or low melting
A high-performance structure in which point alloys are dispersed and joined in a network.
Conductive resin is injection-molded (second color), and in these two steps, it is embedded in the substrate portion made of insulating resin with the surface of the conductive portion made of highly conductive resin exposed, and integrally formed into a flat plate shape.
Molded, the conductive portion is formed in a required circuit, and the circuit bodies are vertically stacked to form the upper and lower circuit bodies.
The connection structure of the internal circuit of the junction box in which the required circuit composed of the above-mentioned conductive portion is directly brought into surface contact for electrical connection. 2. The circuit body has a substantially flat plate shape, and a circuit including the conductive portion is provided on one surface of the circuit body in a planar shape.
The other surface is an insulating surface made of an insulating resin layer, and a part of the planar circuit is three-dimensionally exposed on the other surface of the insulating surface to form a connection portion, and the connection portion is formed on one surface of the circuit body to be laminated. The connection structure of the internal circuit of the junction box according to claim 1, wherein the circuit is provided in surface contact with the circuit for electrical connection. 3. The above-mentioned vertically stacked circuit bodies have a substantially flat plate shape, and a convex portion or a concave portion is provided at a connecting portion thereof, and the concave portion and the convex portion are fitted to each other, or the tip end surfaces of the convex portions are connected to each other. The connection structure of the internal circuit of the junction box according to claim 1, wherein the contact boxes are in contact with each other.