JPH08130817A - Louver fitting structure for electrical connection box - Google Patents

Abstract

PURPOSE: To improve an electrical connection box in radiating the heat generated in the box by forming openings in the side walls of upper and lower covers by notching the side walls and fitting a louver in parallel with insulating substrates with vents at the opening of the upper or lower cover. CONSTITUTION: An opening 5d is formed by notching the front side wall of an upper cover 5 having four side walls. Another opening 6d is also formed by similarly notching the front side wall of a lower cover 6. Insulating substrates 7 carrying electric circuits are housed in multiple stages at prescribed intervals in the covers 5 and 6 in parallel with the lid-side walls 5f and 6f of the covers 5 and 7. A louver 8 having the same shape as the opening 5d of the upper cover 5 has is put in and fixed to the opening 5d. The louver 8 has slit like vent holes which are elongated in parallel with each other and communicated with the gaps between the substrates 7 housed in the cases 5 and 6. Therefore, even when the substrates 7 are arranged in multiple stages, the air flow among the substrates 7 and, accordingly, the heat radiating property of an electrical connection box is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a louver mounting structure for an electric junction box, and more particularly to improving heat dissipation inside the electric junction box.

[0002]

2. Description of the Related Art An electrical junction box used for branching and connecting an automobile wire harness or the like to various electric components has branch connection points concentrated in one place to branch and connect wiring reasonably and economically. With the increasing density of wire harnesses, various types have been developed depending on the vehicle type or application.

An electric connection box such as the one shown in FIG.
As shown in (A) and (B), the insulating boards 3 and 3 having an electric circuit formed inside the upper cover 1 and the lower cover 2 in the form of a square box which are fitted to each other are provided on the side walls of the covers 1 and 2. It is housed at a right angle. As the electric circuit becomes higher in density, the amount of heat generated in each of the insulating substrates 3 and 3 tends to increase, but since the inside is sealed by the upper cover 1 and the lower cover 2, the insulating substrates 3 and 3 are formed. The heat generated by is dissipated only by the heat conduction of the covers 1 and 2 made of synthetic resin. Therefore, the upper cover 1 and the lower cover 2
There was a risk that heat would be trapped inside the product, adversely affecting the electric circuit.

Therefore, as shown in FIG. 5 (A), a large number of ventilation holes 1a, ... Are provided in at least one of the upper cover 1 and the lower cover 2 so that the ventilation causes heat inside the upper cover 1 and the lower cover 2. An electric connection box is provided that radiates heat to the outside. (See Japanese Utility Model Laid-Open No. 63-63021)

[0005]

However, in the above-mentioned conventional electric junction box, since the ventilation holes 1a are provided in the direction orthogonal to the insulating substrates 3 and 3, the insulating substrates 3 and 3 arranged in multiple stages are provided. Of these, only the heat of the upper surface of the insulating substrate 3 arranged in the uppermost stage or the lower surface of the insulating substrate 3 arranged in the lowermost stage is radiated, and the heat facing the gap between the insulating substrates 3 and 3 is difficult to radiate. However, there is a problem that the heat dissipation is not good.

The present invention has been made in order to solve the above-mentioned conventional problems, and provides a louver mounting structure for an electric junction box, which can improve the heat dissipation of the heat generated inside the electric junction box. The purpose is.

[0007]

In order to achieve the above object, a first aspect of the present invention is to provide an insulating substrate having an electric circuit formed inside an upper cover and a lower cover which are fitted with each other.
In an electrical connection box that is housed in a direction perpendicular to the side wall of each cover, the side walls on the same side of the upper cover and the lower cover are each cut out to form an opening, and the insulation is provided in one of the openings of each cover. The present invention provides a louver mounting structure for an electrical junction box, characterized in that a louver having a ventilation port parallel to the board is mounted.

It is preferable to provide a brim portion on the outer surface of the louver, which crosses the vent hole with a predetermined gap. (Claim 2) Further, it is preferable to provide a holding pin on the inner surface of the louver with a gap from the inner surface of the louver to fix the insulating substrate. (Claim 3)

[0009]

According to the first aspect of the present invention, the louver having the ventilation port parallel to the insulating substrate accommodated therein is attached to one of the openings formed by notching the side walls on the same side of the upper cover and the lower cover. When the insulating boards are arranged in multiple stages, the air permeability between the insulating boards is good,
The heat dissipation is greatly improved.

Further, as in claim 2, by providing the outer surface of the louver with a brim portion that traverses the ventilation hole, it is difficult for dust entering the inside of each cover from the ventilation hole to be directly applied to the electric circuit of the insulating substrate. Insulation is improved. Further, by providing the holding pin on the inner surface of the louver as in claim 3, a gap is formed between the inner surface of the louver and the end portion of the insulating substrate, so that the surface between the insulating substrates arranged in multiple stages is formed. Breathability is improved.

[0011]

The present invention will be described in detail below with reference to the embodiments shown in the drawings. The electrical junction box shown in FIG. 1 is made of a synthetic resin such as PPGT (polypropylene glass talc) or PPT (polyethylene terephthalate) and has a rectangular box-shaped upper cover 5.
And a lower cover 6. Above upper cover 5
Of the four side walls, the upper side wall is cut out to form an opening 5d, and has side walls 5a and 5b, a lower side wall 5c, and a lid side wall 5. The lower cover 6 has an opening 6d formed by cutting out an upper side wall out of the four side walls.
b, an upper side wall 6c and a lid side wall 6f.

The upper cover 5 has side walls 5a, 5
b, 5c, 5f to the side walls 6a, 6b, 6 of the lower cover 6
The lock claws 5e and 5e of the lateral side walls 5a and 5b of the upper cover 5 are fitted to the insides of the lower cover 6 and the lower cover 6a.
The upper cover 5 and the lower cover 6 are mutually locked by engaging with the lock holes 6e, 6e of the lateral side walls 6a, 6b. The side walls 5a, 5 of the upper cover 5 are
b, 5c, 5f to the side walls 6a, 6b, 6 of the lower cover 6
It may be a structure to be fitted on the outside of c and 6f.

Inside the upper cover 5 and the lower cover 6, as shown in FIG. 3, an insulating substrate 7, on which an electric circuit is formed, is formed in parallel with the lid side walls 5f and 6f with a predetermined gap t1 therebetween. , 7 are stored in multiple stages. In this embodiment, four insulating substrates 7 are housed in four stages.

A louver 8 having the same shape as the notched side wall is fitted into the opening 5d of the upper cover 5. The louver 8 has lock claws 8d, 8d on both sides, and lock holes 5g, 5 on the lateral side walls 5a, 5b of the upper cover 5.
It is fixed to the upper cover 5 by engaging with g. The louver 8 may be formed of the same synthetic resin as the upper cover 5 and the lower cover 6, but is preferably formed of a material having a high thermal conductivity (for example, nylon with glass). The louver 8 may have a structure in which the louver 8 is fitted and fixed in the opening 6d of the lower cover 6.

As shown in detail in FIG. 3, the louver 8 is
Are formed with slit-shaped vent holes 8a, ..., 8a that communicate with the gap t1 between the insulating substrates 7 housed in the cases 5 and 6 and extend parallel to the insulating substrates 7. . On the outer surface of the louver 8, there are formed brim portions 8b, ..., 8b which stand up diagonally upward in FIG. 3 so as to cross the respective vent holes 8a with a predetermined gap t2 therebetween.

Further, pressing pins 8c, ..., 8c are formed on the inner surface of the louver 8, and an insulating plate is provided with a gap t3 between the inner surface of the louver 8 and the rear end of each insulating plate 7. 7 is fixed. Side wall 5f of the lid of the upper cover 5
Are provided with insertion portions 5h, ... For connecting the electric circuit of each insulating substrate 7 and an external connector.

If the electrical junction box is constructed as described above, after setting each insulating substrate 7 inside the upper cover 5 and fixing the louver 8 to the opening 5d, the inside of each side wall 6a to 6c of the lower cover 6 will be described. Each side wall 5a of the upper cover 5
5c are fitted together, and the lock claw 5e of the upper cover 5 is attached.
By engaging with the lock hole 6e of the lower cover 6, the upper cover 5 and the lower cover 6 are mutually locked. When mounted on a car, as shown in Fig. 2,
The louver 8 is attached upward, and is attached to, for example, the inner wall surface on the driver's seat side in the vehicle interior.

When the insulating substrate 7 in the upper cover 5 and the lower cover 6 generates heat, this heat is conducted to the upper cover 5, the lower cover 6 and the louver 8 and radiated to the outside. Further, since the ventilation port 8a of the louver 8 is provided so as to communicate with the gap t1 of each insulating substrate 7, the air permeability of the portion facing the gap t1 between the insulating substrates 7 arranged in multiple stages becomes good, The heat generated by each insulating plate substrate 7 is radiated to the outside from the gap t1 through the ventilation port 8a. Further, when the heat generated by the insulating substrate 7 is radiated from the ventilation port 8a, the outside air (which is lower in temperature than the air in the upper cover 5 and the lower cover 6) is replaced with this and flows into the gap t1 from the ventilation port 8a. . As described above, in the present embodiment, convection that dissipates the heat inside the upper cover 5 and the lower cover 6 is generated, and the heat generated by the insulating substrate 7 is quickly dissipated to the outside of the electrical junction box.

Further, in this embodiment, since the pressing pin 8c of the louver 8 forms the gap t3 between the inner surface of the louver 8 and the rear end portion of each insulating substrate 7, it cooperates with the gap t1. As a result, the air permeability of the surface between the insulating substrates 7 becomes better, and the heat is radiated to the outside more quickly.

Further, as described above, since the vents 8a of the louver 8 are provided with the brim portions 8b, dust entering the insides of the covers 5 and 6 through the vents 8a can cause an electric circuit of the insulating substrate 7. Since it is difficult to directly contact with, the insulation is improved.

Although the gap t1 between the insulating substrates 7 is constant in FIG. 3, the gap t1 and the vent hole 8a may be different depending on the heat generation amount of each insulating substrate 7. That is, as shown in FIG. 4, insulating substrates 7-1, 7-2,
When the heat radiation amount of the insulating substrate 7-3 is considerably large as compared with the heat radiation amount of 7-4, the gap t between the insulating substrates 7-1 and 7-2.
Insulating substrate 7-3 and insulating substrates 7-2, 7- rather than 1-1
The gaps t1-2 and t1-3 between the three holes are set to be large, and accordingly, the vent holes 8a-2, 8a- rather than the vent hole 8a-1.
The width of 3 may be set large. Gap t1 and vent 8
By setting the dimension of a in this way, the heat generated by each insulating substrate 7 can be radiated more efficiently.

[0022]

As is apparent from the above description, in the louver mounting structure of the electric junction box according to the first aspect of the present invention, the insulating substrate housed inside is formed in one of the openings formed by notching the side walls of the upper cover and the lower cover. Since a louver with a ventilation port parallel to the louver is attached, even if the insulating substrates are arranged in multiple stages, the ventilation between the insulating substrates is good and the heat dissipation is greatly improved even if the insulating substrates are arranged in multiple stages. To do.

Further, when the outer surface of the louver is provided with a brim portion that traverses the ventilation hole as in claim 2, dust entering the inside of each cover from the ventilation hole is directly applied to the electric circuit of the insulating substrate. It becomes difficult and the insulation is improved.

Further, by providing a presser pin on the inner surface of the louver as in claim 3, a gap is formed between the inner surface of the louver and the end of the insulating substrate, so that the surface between the multi-stage insulating substrates is formed. Breathability is improved and heat dissipation is further improved.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of an electric junction box of the present invention.

FIG. 2 is a perspective view of an installed state of the electrical junction box of FIG.

3 is a cross-sectional view taken along the line AA of FIG.

FIG. 4 is a sectional view showing another example of the structure of the louver.

FIG. 5A is a perspective view of a conventional electric junction box, and FIG.
FIG. 3A is a sectional view of a main part of FIG.

[Explanation of symbols]

 5 Upper Cover 5a to 5c Side Wall 5d Opening 6 Lower Cover 6a to 6c Side Wall 6d Opening 7 Insulating Substrate 8 Louver 8a Vent 8b Flange 8c Presser Pin

Claims (3)

[Claims] 1. An electrical junction box in which an insulating substrate having an electric circuit formed therein is housed in an upper cover and a lower cover which are fitted to each other in a direction perpendicular to a side wall of each cover, and the same side of the upper cover and the lower cover. And a louver having a ventilation hole parallel to the insulating substrate is attached to either one of the openings of the respective covers to form an opening by notching each side wall of the louver attachment structure. . 2. The louver mounting structure for an electrical junction box according to claim 1, wherein the outer surface of the louver is provided with a brim portion that traverses the ventilation hole with a predetermined gap. 3. The louver mounting structure for an electrical junction box according to claim 1, wherein a holding pin for fixing the insulating substrate is provided on the inner surface of the louver with a gap from the inner surface of the louver.