JPH11178159A - Waterproofing structure of electrical connection box - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a waterproofing structure which prevents water from entering an electrical connection box. SOLUTION: An electrical connection box 21 is hermetically sealed by mating a lower cover 12 with an upper cover 23. In the electrical connection box 21, a terminal connecting section 15 where infiltration of external water is encircled with a raised waterproofing wall 16 formed inside the lower cover, and further a cap 27 is installed inside the upper cover the cap which is superposed on the waterproofing wall in the direction of the height, thereby shielding the interior of the waterproofing wall when the lower cover is mated with the upper cover.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waterproof structure for an electric junction box mounted in an engine room or the like of an automobile.

[0002]

2. Description of the Related Art FIGS. 2 and 3 show an example of a conventional electric connection box (see Japanese Utility Model Laid-Open No. 2-7717). The electric junction box 1 is composed of a lower cover 2 and an upper cover 3 which are sealed together to seal the inside, and a vent hole 5 for heat radiation is opened in the upper cover 3.

In another conventional electric connection box 11 shown in FIGS. 4 (a) and 4 (b), an LA terminal (wire end portion) 14 of an electric wire terminal drawn from the outside and an internal circuit of the electric connection box are connected. The terminal connection portion 15 to be connected is surrounded by a waterproof wall 16 provided inside the lower cover 12. The waterproof wall 16 is formed at the same height as the peripheral wall 12 a of the lower cover 12, and a space inside the waterproof wall 16 communicates with a notch 17 provided on the peripheral wall 12 a of the lower cover 12 for passing electric wires. Then, with the upper cover 13 fitted to the lower cover 12 and the electric connection box 11 sealed,
Even if rainwater enters the terminal connection part 15 through the wire 7 or the electric wire, the rainwater is stopped by the waterproof wall 16, and inside the electric connection box 11 (the outside of the waterproof wall 16 corresponds to the actual inside of the electric connection box 11). Water droplets are prevented from entering.

[0004]

However, FIG.
Since the electric junction box 1 shown in FIG. 3 has the ventilation holes 5, the heat radiation effect is improved, but water droplets W penetrate through the ventilation holes 5 in consideration of an actual mounting environment (engine room). It was likely.

In the electric junction box 11 shown in FIG. 4, the terminal connection portion 15 is surrounded by the waterproof wall 16 so that some water intrusion can be prevented.
However, there is a problem that waterproofing is not perfect. If the ingress of water droplets is allowed, there is a risk of leaking between the busbars arranged in the electric connection box and corrosion of the busbars. Therefore, improvement in waterproof performance has been desired.

The present invention has been made in view of the above circumstances, and has as its object to provide a waterproof structure of an electric junction box that can more completely prevent water from entering.

[0007]

According to the first aspect of the present invention, in an electric junction box for sealing the inside by combining a lower cover and an upper cover, a portion where water can enter from the outside is set up inside the lower cover. In addition to being surrounded by the raised waterproof wall, a cap is provided inside the upper cover so as to overlap the waterproof wall in the height direction when the lower cover and the upper cover are combined, thereby shielding the inside of the waterproof wall. And

In this structure, the cap provided on the upper cover overlaps the waterproof wall in the height direction, so that the inside of the waterproof wall is reliably shut off. Therefore, even if the water droplets enter the inside of the waterproof wall, they do not reach the inside of the electrical junction box over the waterproof wall. Further, since the cap is merely provided inside the upper cover so as to overlap the waterproof wall of the lower cover, the structure is simple and can be realized at low cost. Further, since the space inside the waterproof wall is isolated from the outside by the waterproof wall and the cap, heat is hardly transmitted inside and outside the waterproof wall.

According to a second aspect of the present invention, there is provided the waterproof structure of the electric junction box according to the first aspect, wherein the portion which is apt to infiltrate water from the outside has a wire terminal portion and an internal circuit drawn from the outside. The terminal end portion of the waterproof cover is drawn into the inside of the lower cover through a notch provided in the peripheral wall of the lower cover, and both ends of the waterproof wall in the circumferential direction are connected to both ends of the notch. The space and the notch communicate with each other.

[0010] In this structure, there is a notch in the peripheral wall of the lower cover in order to guide the electric wire from the outside into the electric connection box, and there is a possibility that rainwater or the like may enter the terminal connection portion from this notch. Even if it enters the part, the terminal connection part is securely shielded by the waterproof wall and the cap,
It does not reach the inside of the electrical junction box. Also,
Even if heat is generated at the terminal connection portion, the heat is blocked by the waterproof wall and the cap, so that the heat is not easily transmitted to the inside.

According to a third aspect of the present invention, in the structure for preventing an electric junction box according to the first or second aspect, the cap is fitted inside the waterproof wall.

In this structure, since the cap on the upper cover side is fitted inside the waterproof wall on the lower cover side,
Even if a water droplet hits the cap, the water droplet flows down inside the waterproof wall and does not enter the outside of the waterproof wall, that is, the inside of the electrical junction box.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a waterproof structure of an electric junction box according to an embodiment. FIG. 1A shows an upper cover 23 and a lower cover 12.
(B) shows the state before the upper cover 23 is set.
In the lower cover 12.

The electric connection box 21 can be hermetically sealed by putting an upper cover 23 on the upper part of the lower cover 12, but a portion where electric wires are drawn in from outside, that is, a peripheral wall of the lower cover 12. LA of electric wire terminal drawn from outside through notch 17 provided in 12a
Rainwater or the like may enter the terminal connection portion 15 between the terminal 14 and the internal circuit from the outside.

Therefore, first, inside the lower cover 12,
A cylindrical waterproof wall 16 is raised and formed so as to surround the terminal connection portion 15, and both ends of the waterproof wall 16 in the circumferential direction are cutouts 17.
The space inside the waterproof wall 16 is communicated with the notch 17 by connecting to both ends of the waterproof wall 16. Further, a cap 27 is provided inside the upper cover 23 so as to cover the inside of the waterproof wall 16 by overlapping the waterproof wall 16 in the height direction when the lower cover 12 and the upper cover 23 are combined.

The cap 27 has a cylindrical wall 27a and a connecting wall 27b, and is integrated with the inner surface of the side wall of the upper cover 23 by the connecting wall 27b.
6 are formed to have dimensions slightly smaller than the waterproof wall 16 so as to fit inside of the waterproof wall 16. Further, the height of the cap 27 is set so as to reliably wrap the waterproof wall 16 by a predetermined dimension H.

As described above, when the upper cover 23 having the cap 27 formed therein is locked with the lower cover 12, the lower end of the cap 27 is fitted inside the waterproof wall 16 and thereby the upper portion of the waterproof wall 16 is fitted. The space is closed.

Therefore, even when the water droplet W enters the terminal connection portion 15 inside the waterproof wall 16, it does not reach the inside of the electric connection box 21 beyond the upper end of the waterproof wall 16. In particular, since the cap 27 on the upper cover 23 side is fitted inside the waterproof wall 16 on the lower cover 12 side,
Water droplets hitting the cap 27 flow down into the waterproof wall 16, and do not enter the outside of the waterproof wall 16, that is, the inside of the electric connection box 21.

Further, since the cap 27 is merely provided inside the upper cover 23, the structure is simple and the cost can be reduced. Further, since the space inside the waterproof wall 16 is blocked by the waterproof wall 16 and the cap 27, even if heat is generated in the terminal connection portion 15, the heat is generated by the electric connection box 2.
1 becomes difficult to be transmitted.

The cap 27 is attached to the upper cover 23.
It is good to continue to the ceiling wall of
May be open at the top.

[0022]

As described above, according to the first aspect of the present invention, the cap provided on the upper cover blocks the waterproof wall on the lower cover side, so that even if water drops enter the inside of the waterproof wall, It can be prevented from intruding inside the electric connection box beyond the waterproof wall. In addition, in terms of structure, since only the cap on the upper cover side is added to the conventional one, the structure is simple and can be realized at low cost. In addition, since the degree of shielding of the space inside the waterproof wall increases, heat is hardly transmitted inside and outside the waterproof wall.

According to the second aspect of the present invention, even if rainwater or the like enters the terminal connection portion through the notch in the peripheral wall of the lower cover, the waterproof wall and the cap prevent water droplets from entering the inside of the electric connection box. Can be. Further, since the heat insulating property is enhanced by the waterproof wall and the cap, even if the terminal connection portion generates heat, the heat is less likely to be transmitted to the electric connection box.

According to the third aspect of the present invention, since the cap is fitted on the inside of the waterproof wall, even if the cap is hit with water droplets, the water droplets flow down inside the waterproof wall and leak outside the waterproof wall. Does not appear.

[Brief description of the drawings]

FIG. 1 is an explanatory view of an embodiment of the present invention, in which (a) is a perspective view showing a state before an upper cover and a lower cover are combined;
(B) is a perspective view showing the combined state.

FIG. 2 is a perspective view of a conventional electric junction box.

FIG. 3 is a sectional view taken along the line III-III of FIG. 2;

FIG. 4 is a configuration diagram of a main part of another conventional electric connection box;
FIG. 3A is a perspective view showing a state before the upper cover and the lower cover are combined, and FIG.

[Explanation of symbols]

 12 Lower Cover 14 Wire Terminal 15 Terminal Connection 16 Waterproof Wall 17 Notch 21 Electrical Connection Box 23 Upper Cover 27 Cap

Claims (3)

[Claims] 1. An electrical junction box for hermetically sealing an interior by combining a lower cover and an upper cover, wherein a portion where water can enter from outside is surrounded by a waterproof wall rising up inside the lower cover, and the upper A waterproof structure for an electric junction box, wherein a cap is provided inside the cover so as to overlap the waterproof wall in the height direction when the lower cover and the upper cover are fitted together to shield the inside of the waterproof wall. 2. The waterproof structure for an electric junction box according to claim 1, wherein a portion where water can enter from the outside is:
A terminal connection portion between an electric wire terminal portion and an internal circuit drawn in from the outside, wherein the electric wire terminal portion is drawn into the lower cover through a notch provided in a peripheral wall of the lower cover, and both ends in the circumferential direction of the waterproof wall are both ends of the notch. By being connected to
A waterproof structure for an electrical junction box, wherein a cutout communicates with a space inside a waterproof wall. 3. The waterproof structure for an electric junction box according to claim 1, wherein the cap is fitted inside the waterproof wall.