JP3308874B2 - Busbar structure of 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 improved technique of a bus bar structure used for connecting a wiring board and a main cover in an electric junction box mounted on an automobile or the like.

[0002]

2. Description of the Related Art Conventionally, many electric parts are used in electric equipment and automobiles having complicated electric elements, and electric circuits for exchanging information, signals or electric power between these electric parts are provided. Centrally interconnected electrical junction boxes are commonly used. In this electric connection box, a wiring board is housed in a case, and the wiring board and the main cover are connected by a bus bar. In general, a structure is used in which the end of the bus bar is exposed to the surface of the main cover and used as a connector terminal. For this reason, these bus bars are inserted and fixed on the wiring board.

FIGS. 4 and 5 show the mounting relationship between a conventional vertical bus bar 1 and a wiring board 2. FIG. The two bus bars 1 shown in the figure are formed in a plurality of bent shapes in the thickness direction according to the wiring patterns. Further, on the surface of the wiring board 2, shallow grooves 3 corresponding to the respective bending patterns are formed, and receiving grooves 4 having a substantially U-shaped cross section are formed at places of the shallow grooves 3. The receiving groove 4 is formed at a position that avoids interference with components arranged on an under cover (not shown) arranged below the wiring board 2 and components arranged on a lower wiring board.

A plurality of projections 1a are provided on the lower edge of each bus bar 1 in accordance with the shape of the receiving groove 4, and these projections 1a are inserted into the receiving groove 4 so that the wiring board 2 is formed. Each bus bar 1 is stably fitted and fixed upward. Reference numeral 1b in FIG. 4 denotes a terminal portion protruding from the upper edge of each bus bar 1.

[0005]

In the bus bar structure having the above-described structure, the height dimension of each bus bar 1 is larger than the height b of the non-formed portion shown in FIG. 5B. As shown in the figure, the height a of the portion where the projection 1a is formed is large. If the bus bar 1 and the part projecting from the undercover cannot cross each other, in order to avoid mutual interference, the lower edge of the non-formed portion may also be cut out in the concave portion, so that the height dimension is reduced. In some cases, it was unavoidable. Therefore, the amount of heat generated by energization of a bus bar having a constant plate thickness is inversely proportional to the height of the bus bar through which the current passes.
Resistance heat is generated in a portion having a small height dimension. Therefore, the heat generated in a portion having a small height dimension causes an increase in the internal temperature, which may cause other components that are sensitive to high temperature to not operate normally or impair the original function. In some cases, the cover or the wiring board may be damaged. There is a problem of causing melting.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and a predetermined vertical cross-sectional area can be ensured even when a concave portion is formed to avoid interference with an undercover or a lower wiring board. An object of the present invention is to provide a bus bar structure of an electric junction box.

[0007]

The object of the present invention is to dispose a wiring board in a main cover, cover a lower portion of the wiring board with an undercover, and project a lower edge side projection on the wiring board.
Parts are in electrical connection boxes used the ends of the vertical bus bars that are plug-in lock as is allowed by the connector terminals exposed on the main cover, the longitudinal bus bars, to avoid interference with parts protruding to the wiring board An upper edge convex portion corresponding to the shape of the concave portion is formed on the upper edge side immediately above the concave portion formed on the lower edge.
And the height of the convex portion is the same as that of the concave portion,
Upper edge side corners of the recess and lower edge side corners of the upper edge protrusion
Is the length connecting the parts equal to the reference height of the vertical busbar?
Or, by setting it to be more than that, the problem can be solved by the bus bar structure of the electric junction box, wherein the vertical cross-sectional area of the vertical bus bar is made substantially uniform.

[0008]

In the bus bar structure of the electric junction box having the above-described structure, the vertical bus bar corresponds to the concave portion formed on the lower edge in order to avoid interference with components protruding on the wiring board, and the concave portion is formed on the upper edge side. A protrusion having a height and a length corresponding to the shape is formed. In addition, the length connecting the lower edge both side corners of the convex portion and the upper edge both side corners of the concave portion is set to be equal to or more than the reference height dimension of the vertical bus bar which can suppress the generated resistance heat to the allowable temperature or less. I have. Therefore, it is possible to reliably eliminate a portion where the width dimension of the vertical bus bar becomes smaller than the reference dimension, generate resistance heat higher than the allowable temperature, and increase the temperature in the electric connection box, thereby damaging temperature sensitive components. Such a situation can be reliably prevented.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a bus bar structure of an electric junction box according to the present invention will be described below in detail with reference to FIGS. FIG. 1 is an exploded perspective view of an electric connection box to which the bus bar structure of the electric connection box of the present invention is applied, FIG. 2 is a plan view showing a main part of the bus bar in FIG. 1, and FIG. It is a perspective view which shows an attachment structure.

As shown in FIG. 1, the electric connection box according to the present embodiment is divided into a plurality of parts, an under cover 10 for accommodating electric connection parts in each of the divided parts, and a cover over the under cover 10. The main cover 14 includes a main cover 14 having a plurality of connector portions protruding from the upper surface thereof, and a wiring board 12 housed in the main cover 14. Further, the lower edge is inserted into and fixed to the wiring board 12, and a pair of vertical bus bars 16 connecting the wiring board 12 and the main cover 14 are assembled on the wiring board 12.

The vertical bus bar 16 is formed by bending a plurality of portions of a metal having good conductivity in accordance with its wiring shape, and a connector terminal 18 inserted into a connector portion of the main cover 14 protrudes from a part of an upper edge. Is formed. At the lower edge of the bus bar 16, a plurality of projections to be inserted into receiving grooves formed in the wiring board 12 and recesses for avoiding interference with parts protruding above the wiring board 12 are formed. I have. However, a convex portion is formed on the upper edge corresponding to the concave portion forming portion on the lower edge, and the height L is formed to be substantially constant regardless of the unevenness on the lower edge side.

As shown in FIG. 2, the reference height L of the bus bar 16 is determined according to the value of the current to be conducted.
Therefore, in the design process, if it becomes necessary to form a recess 20 having a width b and a height a at the lower edge,
At the upper edge of the bus bar 16, a projection 22 having the same height a is formed so as to protrude. However, if the height is simply increased, the width dimension connecting the corners of the lower edges on both sides thereof and the corners of the upper edges on both sides of the concave portion 20 is reduced.

Therefore, both corners of the upper edge of the concave portion 20 and the convex portion 2
2 The convex portion 22 is formed so that a line segment C connecting the lower edge with both side corners is at least equal to or greater than the reference height L.
You need to set the length. For example, when the height a is equal to the reference height L, the length D of the protrusion 22 is
It is set at least (b + 2Ccosθ) or more.

As shown in FIG. 3, a protrusion 20a is formed before and after the formation of the recess 20 on the lower edge side of the bus bar 16. Therefore, when the concave portions 20 are formed at a predetermined pitch, the convex portions 2 are formed on the surface of the wiring board 12.
By forming the insertion groove 24 corresponding to the pitch of 0a, the bus bar 16 can be stably fixed without forming the receiving groove 4 (see FIG. 4). Therefore, the occurrence of sink marks or the like due to the provision of the receiving groove on the wiring board 12 can be reliably prevented.

[0016]

As described above, according to the bus bar structure of the electric junction box of the present invention, the vertical bus bar is located just above the recess formed on the lower edge to avoid interference with the parts protruding on the wiring board. The upper edge side convex part corresponding to the shape of the concave part is formed on the edge side.
The height of the projection is the same as the height of the recess,
That connects the upper edge both side corners and the lower edge both side corners of the upper edge protrusion
Is equal to or greater than the reference height of the vertical busbar
By setting, the longitudinal area of the vertical bus bar is substantially uniform. Therefore, it is possible to eliminate a portion where the width dimension of the vertical bus bar is equal to or smaller than the reference dimension, and it is possible to surely prevent the generation of resistance heat exceeding the allowable temperature. Therefore, it is possible to obtain a highly reliable bus bar without increasing the temperature in the electric connection box to damage the temperature-sensitive components.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a bus bar structure of an electric junction box according to the present invention.

FIG. 2 is a partial plan view showing a main part of the bus bar structure in FIG.

FIG. 3 is a perspective view showing an attachment structure between a bus bar and a wiring board in FIG. 1;

FIG. 4 is a perspective view showing a conventional mounting structure of a bus bar and a wiring board.

5 is a partial sectional view of FIG. 4, (a) is a sectional view taken along line AA of FIG. 4, and (b) is a sectional view taken along line BB of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Under cover 12 Wiring board 14 Main cover 16 Vertical bus bar 18 Connector terminal 20 Depression 22 Convex part D Length of convex part L Reference height dimension

Claims (1)

(57) [Claims] 1. A wiring board is arranged in a main cover, and a lower portion thereof is covered with an under cover.
In an electric connection box used as a connector terminal by exposing an end portion of a vertical bus bar to which a convex portion on a lower edge side is inserted and fixed on the main cover, the vertical bus bar includes a component protruding on the wiring board. An upper edge side convex portion corresponding to the shape of the concave portion is formed on the upper edge side immediately above the concave portion formed on the lower edge to avoid interference, and the height of the convex portion is adjusted.
Is the same size as the recess, and the upper edge of the recess
Length connecting both corners and the lower edge both corners of the upper edge projection
Is equal to or greater than the reference height of the vertical busbar.
By setting, the bus bar structure of an electrical connection box, characterized in that the vertical area of the vertical bus bar is substantially uniform.