JP2001333519A - Circuit body and junction box housing the circuit body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new circuit body and a junction box housing this circuit body, which solve the problem in the conventional bodies that the points of a bus-bar system and a pressure welding system, even though bus-bars formed by punching a conductive metallic board into those having required circuit shapes are mainly used in a junction box for cars as its internal circuit, and electric wires and substances obtained by pressure-welding and connecting pressure-welding terminals to the electric wires are also used in some cases, and there are also cases where both the bus-bar system and the pressure-welding system are used together. SOLUTION: A conductive board 20 for constituting a required circuit in the shape of a bus-bar is made from highly conductive resin. Holes 20a are formed at required spots of the conductive board, and the base parts 21b of terminal metal fixtures 21 are press-fitted into the holes and fixed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit body and a junction box containing the circuit body.
It is suitably used in a shunt box connected to an automobile wire harness.

[0002]

2. Description of the Related Art In a junction box for an automobile, a bus bar formed by stamping a conductive metal plate into a required circuit shape is mainly used as an internal circuit. In addition, an electric wire and an electric wire in which a press contact terminal is press-connected to the electric wire may be used, and the bus bar system and the press-welding system described later may be used together.

On the other hand, in the case of the pressure welding method described later, as shown in FIG. 4 or FIG. 5, the wiring guide portion 1a is provided on the inner surface of the upper case 6 of the junction box 4, the inner surface of the lower case, or the insulating plate 1 housed inside the case. A wire (often a single core wire) w is laid in a single stroke using a wiring robot along the wiring guide portion 1a, and then the press-fit terminal 2 of a terminal fitting is attached to the laid wire w. To form a connection with another internal circuit or an external circuit.

[0004]

In the case of the bus bar system, since the conductive metal plate is punched in an expanded shape and bent at a required position to form a tab, when the tabs overlap in the expanded shape. In such a case, it is necessary to provide a bus bar having tabs projecting from another layer, and there is a problem that the number of bus bar layers tends to increase.

In the case of the pressure welding method described later, the wiring efficiency is increased, but there is a problem that large and complicated automatic pressure welding equipment is required and equipment cost is required, and the wiring process by the wiring robot and the pressure welding process are further performed. A terminal driving step is required. Further, in order to hold the electric wire at a predetermined position, it is necessary to provide a wiring guide portion on the insulating plate. Therefore, when the circuit is changed, the insulating plate also needs to be changed to a shape following the circuit change. Therefore, it is necessary to change the mold for the insulating plate, and there is a problem that the cost is increased also in this aspect. In addition, the bus bar method and the pressure welding method are used in combination, the bus bar layer and the layer composed of the electric wire and the pressure welding terminal are arranged in layers, and there are cases where each is connected to an external circuit. Also in this case, the above cost is required, and there is a problem that it is difficult to adopt it in a model of a mass-market vehicle which aims at low cost.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a novel circuit body which solves the problems of the conventional bus bar system and pressure welding system, and a junction box containing the circuit body. . That is,
Changing the internal circuit of the junction box to a circuit composed of the bus bar and the electric wire and the press-connecting terminal while enabling high-density wiring, or reducing the bus bar and the like by using the same in combination, reducing the above problem, It is an object to provide a low-cost circuit body suitable for mass sales and a junction box containing the circuit body.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a circuit body housed in a junction box, wherein a conductive plate constituting a required circuit having a busbar shape is made of a highly conductive resin. The present invention provides a circuit body characterized in that it is formed, a hole is formed in a required portion of the conductive plate, and a base of a terminal fitting is press-fitted and fixed in the hole.

That is, a conductive plate having a shape similar to that of a bus bar formed by punching a conductive metal plate is molded using a highly conductive resin. The conductive plate has a narrow and long plate shape and is bent according to the shape of the circuit.

In the above-mentioned circuit body, a hole is provided in a required portion of the conductive plate, and the base of the terminal fitting is press-fitted and fixed in the hole to be integrated. With this configuration, the terminal portion can be provided at a position close to an adjacent circuit body, and as a result, the number of layers of the circuit body can be suppressed from being increased as compared with a conventional bus bar.
Also, since the circuit body and the insulating plate can be integrated with either the male terminal or the female terminal as a terminal fitting, the male terminal consisting of the connector, the fuse or the tab of the relay mounted on the junction box and the relay terminal can be used directly. Can be connected.

Further, the present invention provides a junction box in which the above-mentioned circuit is disposed on an upper surface of a lower case of the junction box or on an insulating plate disposed inside a box composed of a lower case and an upper case.

[0011] In the case of the conventional crimping method comprising an electric wire and a crimping terminal, it is necessary to form a wiring guide portion on the inner surface of the case or on the insulating plate. However, the circuit body of the present invention has a shape holding ability. Therefore, there is no need to provide a guide portion for positioning and holding, and a substantially flat insulating plate can be used in common.

The above-mentioned highly conductive resin is disclosed in JP-A-10-237.
No. 331, JP-A-11-342522, thermoplastic resin mixed with metal fibers made of copper, nickel, iron, etc., lead-free solder (low melting point solder) and Cu It is made of a conductive resin composition in which a low melting point alloy such as powder is dispersed.

The thermoplastic resin to which conductive metal fibers are blended includes propylene, polyethylene, polystyrene, acrylonitrile / butadiene / styrene resin, modified polyphenylene oxide resin, polybutylene terephthalate resin, polyethylene terephthalate resin, polyamide resin, aromatic resin Polyamide resin, polyphenylene sulfide resin, liquid crystal polymer, polyetherimide,
Resins such as polybenzimidazole, polyetherketone, and polyethersulfone can be used alone or as a blend, and acrylonitrile-butadiene-styrene resin and polybutylene terephthalate resin are particularly preferably used.

As the low melting point alloy to be mixed and dispersed in the thermoplastic resin and to be joined in a network, an alloy having a melting point of 100 ° C. or higher, preferably 200 ° C. or higher and melting at the time of injection molding is used. System, Sn-Ag
-Pb system, Sn-Bi system, Sn-Bi-In system, Bi-
Pb-based, Bi-Sn-based, Sn-Cu-based, Sn-Cu-N
i-Pb system, Sn-Ag system, Sn-Bi-Pb system, Sn
—In-based ones.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 and 2 show an embodiment of the present invention, in which a first circuit body 11A is arranged on the inner surface of a lower case 10 of a junction box, an insulating plate 12 is laminated on the upper surface thereof, and a first circuit body 11A is formed on the upper surface of the insulating plate 12. 2 circuits 1
1B is arranged, and an upper case 13 is placed on the top of the upper case 1B.

The first circuit body 11A and the second circuit body 11B
As shown in FIG. 2, the circuit body 11 includes a conductive plate 20 molded by using a highly conductive resin and a conductive plate 20.
Terminal fitting 21 for press-fitting and fixing into a hole 20a provided in advance
Consists of

The conductive plate 20 has a shape similar to that of a conventional bus bar formed by stamping a metal plate. The conductive plate 20 is narrow and long and thin, and is bent according to the circuit shape. Of course,
Some circuit shapes are not refracted.

The terminal fitting 21 is formed by bending a metal plate in the same manner as in the prior art, and has a tab-shaped male terminal portion 21a on one side and a stepped-down press-fit portion 2 on the other end.
1b is provided. In addition, instead of the male terminal portion 21a,
As shown in FIG. 3, a female terminal 21a 'may be provided.

The base 21b of the terminal fitting 21 is slightly larger in diameter than the hole 20a of the conductive plate 20 so that the base 21b is fixed to the hole 20a by press fitting.

When assembling a junction box using the circuit body 11 including the conductive plate 20 and the terminal fittings 21, first, the conductive plate 20 is set on the upper surface of the lower case 10. Next, the base 21b of the terminal fitting 21 is press-fitted into the hole 20a of the conductive plate 20 to form the first circuit body 11A.

An insulating plate 12 is provided on the upper surface of the first circuit body 11A.
Place. The insulating plate 12 has an opening 12a through which the terminal fitting 21 of the first circuit body 11A passes. Then, the conductive plate 20 is set on the upper surface of the insulating plate 12, and the base of the terminal fitting 21 is press-fitted and fixed in the hole 20a of the conductive plate 20, thereby forming the second circuit body 11B. After the second circuit body 11B is formed, the upper case 13 is covered. The male terminal portion 21a of the terminal fitting 21 of the circuit body 11 protrudes into a terminal hole 13b of the connector accommodating portion 13a provided in the upper case 13, and a terminal of a connector (not shown) fitted to the connector accommodating portion. Fitted and connected.

In the case where a circuit body is further provided, an insulating plate and a circuit body are alternately laminated. When the circuit body is formed as a single layer, the circuit body 11 is provided on the lower case 10 and then the upper case 13 is covered.

It is needless to say that a circuit body may be formed in advance by press-fitting and fixing a terminal fitting into the hole of the conductive plate, and this circuit body may be arranged on the inner surface of the case or on the insulating plate.

[0024]

As is apparent from the above description, in the circuit body of the present invention, a bus bar-shaped conductor having a required circuit is formed of a highly conductive resin, and a terminal fitting is press-fitted and fixed to the conductor. Since it is provided, the terminal fitting can be provided also in the proximity position. Therefore, unlike the conventional bus bar, it is not necessary to layer the bus bars in relation to the terminal positions, and it is possible to prevent the junction box from being enlarged.

Further, when the circuit body of the present invention is used, large-scale equipment required for forming an internal circuit by laying electric wires becomes unnecessary, and the equipment cost can be reduced. In addition, there is no need to provide a wiring guide or the like on the inner surface of the case where the circuit body is arranged or on the insulating plate, and the shapes of the case and the insulating plate can be simplified.

[Brief description of the drawings]

FIG. 1A is a cross-sectional view of a junction box according to an embodiment of the present invention, and FIG. 1B is an enlarged cross-sectional view of a fixed portion between a conductive plate and terminal fittings. It is.

FIG. 2 is an exploded perspective view of a circuit body.

FIG. 3 is a perspective view showing another embodiment of the terminal fitting.

FIG. 4 is a schematic perspective view showing an assembling procedure in a conventional press contact method.

FIG. 5 is an enlarged sectional view taken along line AA in FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Lower case 11 (11A, 11B) circuit body 12 Insulating plate 13 Upper case 20 Conductive plate 20a Hole 21 Terminal fitting 21a Base

Claims (2)

[Claims] 1. A circuit body housed in a junction box, wherein a conductive plate constituting a required circuit having a bus bar shape is formed of a highly conductive resin, and a hole is formed in a required portion of the conductive plate. A circuit body, wherein a base of a terminal fitting is press-fitted and fixed in a hole. 2. A junction box, wherein the circuit body according to claim 1 is disposed on an upper surface of a lower case of the junction box or on an insulating plate housed in a box formed by the lower case and the upper case.