JP3006673B2 - Electrical 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 an electric connection box used for electric wiring in a vehicle, and to increase the density of bus bars on a bus bar wiring board constituting an internal circuit of the electric connection box to reduce the size and weight of the electric connection box itself. It was made.

[0002]

2. Description of the Related Art FIG. 7 is an exploded perspective view showing an example of a conventional electric junction box. The electric connection box A is configured by housing a stacked bus bar wiring board in which a plurality of bus bar wiring boards 3, 4, and 5 are stacked in an upper case 1 and a lower case 2. Bus bar wiring board of each layer is obtained by arranging a plurality of bus bars 7 having a desired circuit pattern on the insulating substrate 6 (7 _1, 7 ₂ ...). Each bus bar 7 has tabs 7a, 7b, 7c,... As connector terminals at end portions and intermediate portions, and these tab groups penetrate or do not penetrate the terminal holes 6a of the insulating substrate 6; It is led out to the connector housing 8, the fuse housing 9, the circuit breaker housing 9 ', the relay housing 10, and the like, where it is fitted with the connector 13, the fuse 11, the circuit breaker 11', the relay 12, etc. of the terminal of the wire harness W. Connected. Reference numeral 14 denotes a female-female relay terminal.

A plurality of bus bars 7 ₁ ,
7 ₂ ... are usually stamped from a single conductive metal plate, it is formed collectively by bending process (hereinafter, referred to as B method).
However, tabs 7a, 7b,... Are required to be erected in each bus bar. In the B method, the degree of freedom of the bus bar circuit is limited in order to avoid the expanded tabs. The punching yield is low. In addition, since it is necessary to manufacture another mold even for a partial change of the circuit, there has been a problem that a rapid response cannot be performed and a large cost is required.

Therefore, in order to improve the arrangement density of the bus bars,
Japanese Utility Model Laid-Open Publication No. 3-284111 discloses a busbar forming method as shown in FIGS. In FIG. 8, among the bus bars 15 ₁ , 15 ₂ , 15 ₃ , 15 ₄ ..., A group of opposed tabs 16 a and 16 a ′, 16 b and 1
Attention is paid to the combination of 6b '. That is, bus bars 15 ₁ and 15 ₂ and tabs 15 ₃ and 1
5 ₄ ,... Focusing on the group, bus bars 15 ₁ ,
15 ₃ ... and white bus bar 15 _2, 15 ₄ ... as in the two groups B deployment shaped tabs do not interfere, divided into C. Then, as shown in FIG. 9, the bus bar groups of groups B and C are punched and formed from different metal plates, respectively, and combined as shown in FIG. As still another method for improving the arrangement density, there is a method in which all bus bars are individually punched and formed, and are placed on one insulating substrate to form a pattern (hereinafter, both are referred to as an A method).

[0005] According to the above-mentioned method A, the arrangement density of the bus bars on the insulating substrate is improved, but in addition to requiring two or more dies to form one bus bar circuit board, the bus bars are individually or in groups. Since the number of steps for mounting on the insulating substrate increases, the cost as a whole increases. As described above, each of the methods A and B has its own interests and disadvantages, and it is not always satisfactory.

[0006]

SUMMARY OF THE INVENTION The present invention is not limited to these two types of busbars in view of the advantages and disadvantages involved in forming a bus bar by both the above types A and B. It is an object to provide an electric junction box having a structure that can be manufactured at low cost.

[0007]

In order to achieve the above object, the present inventor has proposed the bus bar wiring boards 3, 4, 5 in FIG.
Observe the arrangement of the bus bars 7 (7 ₁ , 7 ₂ ...) With respect to the insulating substrate 6 of FIG.
Was used to the maximum extent, and it was found that there was considerable free space V. At the same time, when the upper case 1 is divided into left and right areas (P ₁ , P ₂ ) by a virtual line P,
Among all bus bar 7 constituting the bus bar wiring board 3-5 of the layers, the tab of the circuit pattern or at both ends, for example by extracting the bus bars present only in one of the zones P _1, these bus bar group first centrally disposed layer or the uppermost layer of the bus bar wiring board 3, and the installation space is conceived to be limited to the area P ₁ half.

The electric junction box of the present invention has been made based on the above idea, and includes a lower case and an upper case.
A busbar wiring board consisting of a plurality of busbars arranged on an insulating substrate is stacked and accommodated, and various connector housings such as a fuse housing, a relay housing, and a wire harness connection housing are provided on the outer surface of the case. An electrical connection box in which connector terminals derived from busbars of the busbar wiring board are housed and arranged, wherein the uppermost (or lowermost) busbar wiring board comprises:
A bus bar having a connector terminal led out to only one of the two regions of the lower case and the upper case, and an insulating substrate having a space corresponding to the one region for disposing the bus bar And a step is formed between itself and another bus bar wiring board.

According to the first aspect of the present invention, the size of the outermost layer (eg, the first layer) of the insulating substrate is formed to be approximately half the size of the other layer of the insulating substrate (hereinafter, one-sided insulating substrate). ). Accordingly, there is a step between the one-sided insulating substrate of the first layer and the insulating substrate of the second and subsequent layers, and the tab is raised from the bus bar in the insulating substrate of the second and subsequent layers by an amount corresponding to the step. The length can be shortened, and the electrical junction box can be made thinner. In addition, since the length of the expanded tab is shortened by the shortening of the tab, the arrangement density and the punching yield of the entire tab group formed by punching from one metal plate are improved. This makes it possible to reduce the size and weight of the entire electric junction box and reduce costs.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A specific example of an embodiment of the present invention will be described below with reference to FIGS. FIG. 1 (A),
FIG. 2B is a plan view of an upper case and a plan view of a lower case constituting the electric connection box, FIG. 2 is a plan view of a first-layer bus bar wiring board of the electric connection box of FIG. 1, and FIG. FIG. 4 shows a plan view of the board, and FIG. 4 shows a plan view of the third-layer bus bar wiring board. In FIG. 1, reference numeral 21 denotes a lower case made of a synthetic resin insulator constituting an electric junction box according to the present invention, and reference numeral 22 denotes an upper case. The symbol Q is an imaginary line that bisects the two cases 21 and 22 into upper and lower (or left and right) sections Q ₁ and Q ₂ . In the lower case 21, the connector housing a in the upper zone Q _1, b, c, d and relay housing e are arranged, the housing connector is in the lower zone Q ₂ a '
Is arranged. On the other hand, in the upper case 22, the fuse block f and circuit breaker housing g with a housing f ₀ for a number of fuses are arranged in the upper section Q _1, the connector housing h is the lower region Q _2, i, j, k and l (ells) are arranged, and fusible link housings f ′ and f ″ are arranged so as to straddle both areas Q ₁ and Q ₂ .

In FIG. 2 to FIG. 4, the first-layer bus bar wiring board 23 is a second- and third-layer bus bar wiring board 24,2.
5 and approximately half the size of the upper section Q _1.
It is a size that fits in. This first-layer busbar wiring board 2
3 denotes a plurality of bus bars 27 ₁ , 2 on the insulating substrate 26 _1.
7 ₂ , 27 ₃ (27 in the representative case). In other words, these bus bars 27 are provided on the corresponding bus bar mounting grooves 26a ₁ , 26a ₂ , 2 provided on the insulating substrate 26 _1.
6a ₃ ... And are fixed by welding bosses 28 protruding from key portions of each groove edge. Further, each bus bar 27 has tabs 27a, 27 as connector terminals at an end or an intermediate portion.
b, 27c,...
_1-26 a terminal hole 26b provided in the ₃ to penetrate or through non in the upper zone Q ₁ connector housing in a, b, deriving c, d, relay housing e, the fuse block f or circuit breaker housing g Is done.

The bus bar wiring board 24 of the second layer is also
Wherein the 6 ₂ at a point which is formed by arranging a plurality of bus bar 27 first
Has the same basic configuration as the bus bar wiring board 23, and a detailed description thereof will be omitted. However, the second-layer bus bar wiring board 24
Each bus bar 27, the distribution設区gamut insulating substrate 26 ₂ throughout, i.e. the and extends over the upper section Q _1, the lower section Q _2, the bus bar wiring board 4 and 5 of FIG. 7 showing a conventional example Similarly, it is arranged using the whole space. Therefore, the tabs 27a ', 2 of each bus bar 27 in the bus bar wiring board 24
7b ', 27c' ... group, said upper section Q connector housing a in ₁ is not limited to b like, lower region Q
_2, the connector housings a ', h, i, j, k and l,
Further, it is led out to _{one of} the fusible link housings f 'and f "which straddles both areas Q ₁ and Q _2. The third-layer bus bar wiring board 25 is the same as the second-layer bus bar wiring board 24. The description is omitted.

[0013] Figure 5 shows the main part of the circuit formed by lamination of the bus bar wiring board 23 to 25, the circuit 29 shown by a solid line in the first layer of the bus bar wiring board 23, which is limited to the upper zone Q ₁ The bus bar 27 is connected to a circuit 30 indicated by a broken line.
Indicates bus bars 27 of the second and third layers. That is, in the upper zone Q _1, the connector housing a lower case 21 of the first layer once through the bus bar 27 of the bus bar wiring board 23 enters the fuse block f, the same first layer therefrom busbar wiring board 23 busbar Housing b via 27
Connected to. The housing c is similarly connected to the housing a. However, since the housing j is in the lower region Q _2, housing a by a second, bus bar 27 of the third layer
Connected to Further, in the lower region Q _2, housing l (el) is connected to the housing a by the second, bus bar 27 of the third layer, housing a, c, busbars 27 of the first layer is d, the housing h, k Are connected to each other by bus bars 27 of the second and third layers.

FIG. 6 shows the bus bar wiring board 2 of FIGS.
It is sectional drawing of the state which laminated | stacked 3,24 and 25. As is clear from the figure, the busbar wiring board 2 of the first and second layers
Between 3 and 24 there is a step D in correspondence with the upper zone Q _1, the lower section Q _2. Therefore, the tab 27a and the tab 27a '
Assuming that the rising lengths L from the plate surfaces (the insulating substrates 26 ₁ and 26 ₂ ) are equal, the lower section Q ₂ can be reduced by an amount corresponding to the step 30. As a result, the length of the expanded tab is also reduced, so that the punching yield and arrangement density are improved, and the entire electrical junction box can be made thinner and lighter.

The above is the uppermost first-layer bus bar wiring board 2
3 has been described as an example in which the space is half that of the busbar wiring boards 24 and 25 of the second and third layers. However, the space can be replaced with the busbar 25 of the lowermost third layer. It may be applied to the outermost layer. Also,
If the space can be reduced to 1/3 to 3/4 the size of the other layers, there is an advantage of applying the present invention.

[0016]

As described above, according to the present invention,
The size of the insulating substrate of the outermost layer (for example, the first layer) is formed to be approximately half the size of the insulating substrate of the other layers. There is a step. The upright length of the tab from the bus bar in the insulating substrate of the second layer and thereafter can be shortened by the amount corresponding to the step, and the electric connection box is thinned. Moreover, since the length of the expanded tabs is shortened by the shortening of the tabs, the arrangement density and the punching yield of the entire tab group formed by punching from a single metal plate are improved, whereby the electrical connection is improved. The entire box can be reduced in size and weight and cost can be reduced.

[Brief description of the drawings]

FIG. 1A is a plan view of an upper case constituting an electric junction box according to the present invention, and FIG. 1B is a plan view of the lower case.

FIG. 2 is a plan view of a first-layer busbar wiring board of the electric junction box of FIG. 1;

FIG. 3 is a plan view of the second-layer bus bar wiring board.

FIG. 4 is a plan view of the third-layer bus bar wiring board.

FIG. 5 is an explanatory view of a main part of a circuit obtained by the bus bar wiring board of FIGS. 2 to 4;

FIG. 6 is an explanatory diagram of a stacked state of the bus bar wiring boards of FIGS. 2 to 4;

FIG. 7 is an exploded perspective view showing an example of a conventional electric junction box.

FIG. 8 is a perspective view showing another example of a conventional bus bar circuit.

FIG. 9 is an explanatory view showing a step of forming the bus bar circuit of FIG. 8;

[Explanation of symbols]

D step Q _1, Q ₂ regions a, b, c ... housing 21 lower case 22 upper case 23 to 25 busbar wiring board 26 _1, 26 ₂ ... insulating substrate 27 (27 ₁ ...) bus bars 27a, 27b ... tab (connector terminals )

Claims (1)

(57) [Claims] 1. A busbar wiring board comprising a plurality of busbars arranged on an insulating substrate in a lower case and an upper case. The busbar wiring board is housed in a fuse housing, a relay housing, and a wire harness connection on the outer surface of the case. An electrical connection box provided with various connector housings such as housings, and housing terminals arranged in each housing to accommodate connector terminals derived from busbars of the busbar wiring board, wherein the uppermost (or lowermost) busbar wiring board is provided. Has a bus bar having connector terminals led out only in one of the two divided areas of the lower case and the upper case, and a space corresponding to the one area for disposing these bus bars. An electrical junction box comprising an insulating substrate and a step formed between the busbar and another busbar.