GB2318226A - Junction box with wire interconnection - Google Patents

Abstract

A junction box with bus-bars 3,39,40,41,50,51 and wiring boards 2,38 sandwiched between casing parts 31,43 has at least two busbars 40,51 or 41,50 joined by a wire 54 or 53, with the wire being connected to a press connecting blade 40B,51B or 41B,50B on each bus bars. The box is intended for various models of vehicle.

Description

ELECTRICAL JUNCTION BOX This is a divisional application based upon application number 9513517.4 (publication number 2293052).

This invention relates to an electrical junction box, and more particularly to an electrical junction box provided for wiring up an automobile.

In wiring up an automobile, in order to simplify the wiring of the wire harnesses, an electrical junction box is used which is to collectively arrange relays and fuses. In the electrical junction box, circuits made up of bus bars formed by pressing copper or brass plates are provided in a plurality of layers.

In the electrical junction box, a wiring board which is an insulated substrate is provided, and a tab raised at one end of a bus bar arranged on the wiring board is inserted in a connector mounting section of a main cover, and another tab raised at the other end of the bus bar is passed through the wiring board and inserted in a connected mounting section of an under cover.

Recently, automobiles have been markedly improved in performance, and accordingly increased in the number of electrical components, and in the number of circuits to be held in an electrical junction box. Hence, depending on the model or grade of an automobile, it is often necessary to change the electrical circuit of the electrical junction box. In such a case, heretofore an electrical junction box is newly prepared which has bus bars specially designed for the circuit thus changed.

However, the above-described conventional electrical junction box suffers from the following difficulties: That is, in order to form the required electrical junction box, components for realizing the given circuit must be newly arranged, and particularly the bus bars specially designed therefor must be newly manufactured. Thus, the employment of the conventional electrical junction box is not practical in the saving of cost and time.

On the other hand, a technique is known in the art that a main electrical junction box having a fundamental circuit is connected to an auxiliary electrical junction box, to increase the electrical function thereof. However, the technique is disadvantageous in that the electrical junction boxes each has a relatively large unwanted space, and occupy a relatively large installation space.

Accordingly, an object of the invention is to eliminate the above-described difficulties accompanying a conventional electrical junction box. More particularly, an object of the invention is to provide an electrical junction box for wiring up an automobile of which the electrical circuit can be increased or decreased in function with components used in common so that the electrical junction box is applicable to a different model of an automobile having a different electrical circuit.

In order to attain the above object, the invention provides an electrical junction box comprising: a wiring board; a plurality of bus bars arranged on said wiring board and each having at least one tab raised from the bus bar; a main cover having a connector mounting frame into which the tab of at least one of said plurality of bus bars is inserted; and an under cover having a connector mounting frame into which the tab of another of said plurality of bus bars is inserted, wherein at least two of said plurality of bus bars each has at least one press-connecting blade, said pressconnecting blades of said bus bars being electrically connected to each other by a coupling wire.

In the drawings: Fig. 1 is an exploded perspective view showing an example of -he electrical junction box, which constitutes an embodiment of the invention; and Fig. 2 is an explanatory diagram showing an extended circuit in the electrical junction box shown in Fig. 1.

Preferred embodiments of the intention will be described with reference to FIGS. 1 and 2.

Fig. 1 is an exploded perspective view showing an example of the electrical junction box, which constitutes an embodiment of the invention. The electrical junction box 31, as shown in Fig. 1, includes: a wiring board 2; bus bars 3 over the wiring board 2, and bus bars 50, 51 and 52 under the wiring board 2; a special wiring board 38; special bus bars 39 over the special wiring board 38, and special bus bars 40 and 41 under the special wiring board 38; and a main cover 37 and an under cover 43 accommodating those wiring boards and bus bars.

Those bus bars 3, 39, 40, 41, 50, 51 and 52 are independent of one another, and have tabs 3A, 39A, 40A, 41A, 50A, 51A, and 52A raised respectively at the ends.

Those tabs are inserted into connector mounting frames 36 and 42 formed on the main cover 37 and the under cover 43.

At least two of the bus bars each has at least a press-connecting blade. The press-connecting blades are electrically connected to each other by a coupling wire.

In the electrical junction box shown in Fig. 1, for instance the bus bar 50 and the special bus bar 41 have press-connecting blades 50B and 41B, respectively, which are extended downwardly. An electrically conductive coupling wire 53 is pressed against the press-connecting blades 50B and 41B, so that the bus bars 50 and 41 are electrically connected to each other. Similarly, the bus bar 51 and the special bus bar 40 have press-connecting blades 51B and 40B, respectively, which are extended downwardly. An electrically conductive coupling wire 54 is pressed against the press-connecting blades 51B and 40B, so that the bus bars 51 and 40 are electrically connected to each other.

As was described above, the bus bars separated from each other can be electrically connected to each other through the press-connecting blades and the coupling wire.

This means that the combination of the common bus bars and the special bus bar has a markedly increased degree of freedom, and accordingly an electrical circuit more intricate in arrangement and higher in efficiency can be formed with ease. In addition, the electrical circuit thus formed can be readily modified, where necessary.

Fig. 2 is an explanatory diagram showing an extended electrical circuit which is formed in the electrical junction box by using the press-connecting blades and the coupling wires.

In Fig. 2, reference characters S1 through S7 designate the outputs of the common circuit, which include DEF, STOP, ECU-B, TAIL, ECU-IG, GAUGE, WIPER, TURN, CIG, RADIO, IGN and ST outputs.

Further in Fig. 2, reference characters El through E4 designate the outputs of the extended circuit, which include P/W, D/L, FOG, TRC, HTR, NAVI, SEAT HTR and CRT outputs.

As shown in Fig. 2, the output El is obtained through the coupling wire 35 from the output S2 or S3 of the common circuit, and the output E2 is obtained through the coupling wire 35 from the output S5 of the common circuit.

As was described above, with the electrical junction box of the invention, the electrical circuit can be readily extended in function by use of the press-connecting blades and the coupling wires. Hence, the electrical junction box can be readily applied to a different model of an automobile having a different electrical circuit, which reduces the manufacturing cost.

In assembling the electrical junction box, the common bus bars, the common main cover, and the common under cover are used, which contributes to a reduction in the number of components. As a result, the assembling work is greatly improved in work efficiency, and is free form a difficulty that inappropriate components are assembled. Accordingly, the probability that defective electrical junction boxes are manufactured is greatly decreased.

In the above-described embodiment, for convenience in description, only the selected bus bars have the pressconnecting blades; that is, the bus bars 50 and 51 and the special bus bars 40 and 41 on the side of the under cover 43 have the press-connecting blades 50B, 51B, 40B and 41B.

However, the invention is not limited thereto or thereby.

That is, the electrical junction box may be so modified that the bus bars 3 and the special bus bars 39 on the side of the main cover 37 have the press-connecting blades.

As is apparent from the above description, with the electrical junction box of the invention, the bus bars and the wiring board can be applied, as they are, to a different model of an automobile having a different electrical circuit, markedly reducing the manufacturing cost of the latter.

In assembling the electrical junction box, the common components (i.e., the bus bars and the wiring board) are used, so that the number of components is reduced as much.

As a result, the difficulty is eliminated that inappropriate components are assembled. Accordingly, the probability that defective electrical junction boxes are manufactured is greatly decreased, and the assembling work is markedly improved in work efficiency.

Claims (2)

1. An electrical junction box comprising: a wiring board; a plurality of bus bars arranged on said wiring board and each having at least one tab raised from the bus bar; a main cover having a connector mounting frame into which the tab of at least one of said plurality of bus bars is inserted; and an under cover having a connector mounting frame into which the tab of another of said plurality of bus bars is inserted, wherein at least two of said plurality of bus bars each has at least one press-connecting blade, said pressconnecting blades of said bus bars being electrically connected to each other by a coupling wire.

2. The electrical junction box according to claim 1, wherein said bus bars having the press-connecting blades are arranged on a lower surface side of said wiring board.