JPH0649065Y2 - Electrical junction box - Google Patents

Description

[Detailed Description of the Invention] Purpose of the Invention [Industrial field of application] The present invention mainly relates to an electric connection box used for an electric circuit of an automobile, and is improved in terms of heat dissipation and prevention of leakage current. is there.

[Conventional technology]

Conventionally, as an electrical junction box used for this type of application,
There is one such as illustrated in FIG. 4 in a partially cutaway perspective view.
That is, in this electric junction box A ′, a plurality of bus bars 4 punched and formed in a predetermined circuit pattern in a box body 3 formed by combining an upper case 1 and a lower case 2 are arranged on both sides of an insulating substrate 5. In addition to accommodating the wiring board 6
A plurality of connectors 7 and fuse cases 8 are provided on the outer surfaces of the upper and lower parts 1 and 2, and the bus bar 4 is provided in the connection parts.
A group of tabs 4a, 4a ... Standing and linked to each other is projected, and reinforcing ribs 9 are vertically and horizontally combined to form a block 10 on the inner surfaces of the upper and lower cases 1 and 2.

[Problems to be solved by the invention]

However, in such a conventional electrical junction box, as shown in FIG. 5, a part of the rib 9 comes into contact with the bus bar 4 and the rib 9
The clearance C between the insulating substrate 5 and the insulating substrate 5 is extremely small, and the block 10 formed in the vertical and horizontal ribs 9 constitutes a closed chamber. Therefore, the heat generated by the current flowing through the bus bar 4 cannot be sufficiently dissipated. However, the deterioration of the constituent materials, especially the deformation and melting of the insulating substrate made of synthetic resin may occur. Further, if water once enters the box 3 or if dew condensation occurs due to a temperature difference, drainage cannot be performed due to the closed chamber structure, and a leak current is generated between the bus bars having a potential difference, and the bus bars There was also a large risk of poor insulation and corrosion.

The purpose of the present invention is to focus on the problems of the conventional electrical junction box, effectively dissipate the heat accumulated in the box body, and quickly drain the water even if water enters to suppress the occurrence of leak current. It is to provide an electrical junction box.

Configuration of the Invention [Means for Solving the Problems] The present invention will be described below with reference to the drawings illustrating an embodiment.

FIG. 1 is a schematic perspective view of the electric junction box of the present invention, FIG. 2 is a partially cutaway perspective view of the same with the upper case removed, and FIG. 3 is a sectional view taken along the line III-III.

As shown in these figures, an electric junction box A of the present invention is a box consisting of an upper case 1 and a lower case 2 with a wiring board 6 having a bus bar 4 formed in a predetermined circuit pattern on an insulating substrate 5. In an electrical junction box that is housed in a body 3 and has a plurality of reinforcing ribs 9 formed in blocks in the vertical and horizontal directions on the inner surfaces of the upper case 1 and / or the lower case 2, the uppermost layer and ( Or) sandwiching the busbar 4 of the lowermost layer, and providing ventilation grooves (or holes) 12 on both side walls of the upper case 1 and / or the lower case 2 which face each other and are orthogonal to the plate surface of the wiring board 6, The ribs 9 that sandwich the bus bar 4 are provided with cutouts 11 for ventilation and water communication that communicate with the ventilation grooves (or holes) 12 on the both side walls.

It is preferable that the notch 11 is as large as possible within the range in which the original reinforcing effect of the rib 9 is not impaired and is provided so as to reach the inner wall of the upper or lower case 1 or 2. In the example shown,
Since the electric junction box A is arranged with the longitudinal direction of the wiring board 6 being vertical, the notch 11 is provided only on the transverse portion 9a of the rib 9 so as to vertically penetrate the inside of the box body 3, but the longitudinal portion 9b. Alternatively, the blocks 10 adjacent to each other may be communicated with each other by the notch portion 11.

In addition, the box body 3 corresponding to the plurality of notches 11 that penetrate vertically
Ventilation grooves (or holes) 12 are provided on both upper and lower opposite side walls of the. In the illustrated example, the ventilation groove 12 is provided in the lower portion of the peripheral wall portion 2a of the lower case 2, and the escape groove 14 associated with the lock claw 13 that engages with the upper case 1 is provided in the upper portion. Therefore, the vent hole 12 is also used as the escape groove 14. As described above, in the case where the lock claw 13 and the escape groove 14 for the other are provided on one of the upper and lower cases, the vent hole is formed.
12 can be omitted.

The above electrical junction box A is an example in which a single wiring board 6 having bus bars 4 on both sides is housed in the box body 3, but is housed in a plurality of layers including a single-sided wiring board. In some cases, a spacer (not shown) may be interposed between the opposing wiring boards to form an appropriate ventilation space.

[Action]

When the electric junction box A of the present invention is used by vertically arranging it as shown in FIG. 2, for example, the heat generated by energizing the bus bar 4 heats the surrounding air and is shown by an arrow P in FIG. As a result, the ascending airflow passes through the notch 11 of the rib 9 in each block 10 and flows out from the escape groove 14 and the through hole (not shown) of the tab 4a in the connector 7. At the same time, since cold air flows in from the ventilation groove 12 at the bottom of the box body 3, a kind of chimney effect is produced, and the heat dissipation of the bus bar 4 is promoted.

On the other hand, even if water enters the box body 3, as shown by the arrow Q in the opposite direction, the water is sequentially flowed through the notch 11 and discharged from the ventilation groove 12, so that the water enters the box body 3. It is possible to suppress the generation of leak current between the bus bars 4 without staying.

Further, by providing the rib 9 with the notch 11, the rib 9
And the insulating substrate 5 or the bus bar 4 (fifth
Since it is possible to set the size such that the tip comes into contact with the insulating substrate 5 and the like, the bus bars 4 of the uppermost layer and the lowermost layer are respectively sandwiched by the upper and lower ribs 9, and the rattling or the like may occur. It is possible to prevent the generation of abnormal noise.

Advantageous Effects of Invention The present invention accommodates a wiring board, in which a bus bar formed in a predetermined circuit pattern is arranged on an insulating substrate, in a box body composed of an upper case and a lower case, and the inner surface of the upper case and / or the lower case. In an electric junction box in which a plurality of reinforcing ribs are vertically and horizontally block-formed, the uppermost and / or lowermost busbars are sandwiched by the plurality of ribs, and the upper case and / or the lower case are Ventilation grooves (or holes) are provided on the opposite side walls that are orthogonal to the board surface of the wiring board, and the ribs that sandwich the busbar are for ventilation and water communication that communicate with the ventilation grooves (or holes) on the side walls. Since it has a configuration in which the notch portion is provided, by arranging it vertically or inclined so that the both side walls are located vertically, the breathability and drainability are good, and It is possible to suppress deterioration of the constituent members due to heating and leakage current due to water, and effectively prevent deterioration of the insulating property, and it is also possible to prevent abnormal noise due to rattling of the internal wiring board and bus bar.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic perspective view showing an embodiment of the electrical junction box of the present invention, FIG. 2 is a partially cutaway perspective view of the same with the upper case removed, and FIG. Fig. 2 is a sectional view taken along line III-III, Fig. 4 is a partially cutaway perspective view of a conventional electric junction box, and Fig. 5 is a sectional view taken along line VV in Fig. 4. 1 ... upper case, 2 ... lower case, 3 ... box, 4
...... Bus bar, 5 ...... Insulation board, 6 ...... Wiring board, 9 ......
Ribs, 10 ... Blocks, 11 ... Notches, 12 ... Ventilation grooves (or holes), 14 ... Escape grooves.

 ─────────────────────────────────────────────────── ───Continued from the front page (56) References Microfilm (JP, U) taken from the detailed description and drawings attached to the application for Japanese Patent Application No. 60-35335 (No. 61-153427). )

Claims (1)

[Scope of utility model registration request] 1. A wiring board having bus bars formed in a predetermined circuit pattern arranged on an insulating substrate is housed in a box made up of an upper case and a lower case, and is reinforced on the inner surface of the upper case and / or the lower case. In an electrical connection box formed by vertically and horizontally block-forming a plurality of ribs, the bus bars of the uppermost layer and / or the lowermost layer are sandwiched by the plurality of ribs, and the wiring board in the upper case and / or the lower case is Ventilation grooves (or holes) are provided on both side walls facing each other orthogonal to the plate surface, and a rib for holding the busbar is provided with a cutout portion for ventilation and water communication communicating with the ventilation grooves (or holes) on the both side walls. An electric connection box characterized by being provided with.