JPH10322849A - Electric connection box - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the temperature rise inside a case, by providing an electronic connection box with an opening for heat radiation on top of the upper case, providing it with a heat radiation part, and projecting a part of the bus bar for a large current accommodated in the case through the opening. SOLUTION: Bus bars 3a, 3b, and 3c, which has desired circuit patterns, and insulating boards 4a and 4b are stacked alternately in the interior 7 of the case consisting of a lower case 1 and an upper case 2. Then, this electric connection box is provided with an opening 5 for heat radiation in the shape of a thin rectangle on top of the upper case 2, while at a bus bar 3c for a large current arranged in the uppermost layer a heat radiation part 6 bent upward is made in the position corresponding to the opening 5 for heat radiation. This heat radiation part 6 is covered with an upper case 2 while being passed through the opening 5, and further the upper case 2 is covered with an upper case 10 on one hand, and the lower case 1 is covered with a lower case on the other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric junction box mounted on a motor vehicle, and more particularly to an electric junction box for radiating heat inside a case and suppressing an increase in temperature inside the electric junction box.

[0002]

2. Description of the Related Art An electric junction box such as a junction box mounted on an automobile is, as shown in FIG.
Bus bars 43a to 43d and insulating plates 44a to 44c are alternately stacked and arranged alternately from the lower case 41 side to the upper case 42 side inside a case including the first case 1 and the upper case 42. Further, the lower case 41 and the upper case 42 are protected by covering them with a lower cover and an upper cover (not shown).

[0003]

When the bus bars 43a to 43d are arranged in multiple layers inside the case as described above, the bus bars may be heated to increase the temperature inside the case and cause malfunction of the electric circuit. was there. That is, since the lower case 41 and the upper case 42 are locked and locked inside the case, the heat generated in the bus bars 43a to 43d for supplying current is confined inside the case, and the temperature inside the case rises. It's easy to do. In this case, there is a problem that the heat generated by the bus bar through which a large current flows is particularly large.

[0004] In view of the above problems, an object of the present invention is to suppress a rise in temperature inside a case.

[0005]

According to a first aspect of the present invention, a bus bar and an insulating plate are stacked and arranged inside a case formed by combining a lower case and an upper case. In the electric junction box in which the upper case is covered with the upper cover, an opening for heat dissipation is provided on the upper surface of the upper case, and a part of the large current bus bar housed inside the case is protruded to provide a heat dissipation portion. An electric connection box is provided in which a heat radiating portion of a bus bar is projected through the opening.

With the above configuration, a part of the high-current bus bar projects outside the case from the opening on the upper surface of the upper case, so that heat generated in the bus bar inside the case is efficiently dispersed to the outside of the case. To dissipate heat. Therefore, it is possible to prevent a rise in the temperature inside the case without keeping the heat inside the case.

It is preferable that the heat radiating portion of the large current bus bar protrudes into an upper cover that covers the upper case. With this configuration, the bus bar protruding outside the case is protected by the upper cover.

It is preferable that a duct is protruded from a peripheral edge of the opening, a radiating port is provided on a side surface on a tip side of the duct, and a radiating portion of the bus bar is projected to the duct.

By projecting the heat radiating portion of the large current bus bar into the duct portion as described above, it is possible to maintain good insulation and to prevent adhesion of dust and the like, and to reduce the heat generated in the bus bar by the heat radiating opening. Heat can be efficiently radiated outside the case.

It is preferable to provide a large number of small holes for heat radiation on the wall of the duct. With this configuration, heat generated in the bus bar can be more efficiently radiated to the outside of the case.

Further, it is preferable that the high-current bus bar is arranged on the uppermost layer inside the case. With this configuration,
It is possible to efficiently dissipate heat from the large-current bus bar that generates a large amount of heat.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment of the present invention, in which a bus bar 3a having a desired circuit pattern is provided inside a case 7 composed of a lower case 1 and an upper case 2.
3b, 3c and insulating plates 4a, 4b are alternately stacked. Among them, the bus bar 3c arranged on the uppermost layer is a bus bar for a large current connected to a power supply circuit.

On the upper surface of the upper case 2, a narrow rectangular heat-radiating opening 5 is provided. On the other hand, the large current bus bar 3c disposed in the uppermost layer has a heat radiation portion bent upward at a position corresponding to the opening 5.

In the electric junction box, after the bus bars 3a, 3b, 3c and the insulating plates 4a, 4b are stacked and accommodated on the lower case 1, the upper case 2 is inserted while the heat radiation portion 6 of the bus bar 3c is inserted into the opening 5. I'm covering it. The lower case 1 and the upper case 2 assembled in this manner lock a lock claw (not shown) protruding from the peripheral wall of the lower case 1 and a lock claw (not shown) protruding from the peripheral wall of the upper case 2. Locked. Thereafter, the upper case 2 is covered with the upper cover 10 while the lower case 1 is covered with a lower cover (not shown).

In such an electric junction box, the heat generated inside the case is released from the opening 5. Further, since the heat radiating portion 6 refracted from the large current bus bar 3c protrudes from the opening 5, heat of the large current bus bar 3c having a large calorific value is radiated from the heat radiating portion 6 to the outside, and the lower case 1 and the upper case 2 prevents the temperature inside of the case 7 from rising, without keeping heat inside the case 7 sealed.

FIG. 2 shows a second embodiment, in which the same members as those in the first embodiment have the same reference numerals. Opening 5 of upper case 2
A duct portion 8 composed of a hollow body surrounding the heat radiating portion 6 of the bus bar 3c for large current is protruded upward from the peripheral edge of the bus bar 3c. A heat radiation opening 9 is provided at the upper end of the side surface of the duct portion 8.

Since the heat radiating portion 6 of the large current bus bar 3c protruding to the outside of the case is protruded into the duct portion 8 and protected by the duct portion 8, the insulating property of the bus bar can be maintained well and dust and the like can be maintained. Can be prevented from adhering. Further, since the heat radiation opening 9 is provided at the tip of the duct portion 8, heat can be radiated inside the case 7 and the large current bus bar 3c
Can be efficiently radiated to the outside of the case through the radiator 6.

FIG. 4 shows a third embodiment, which is different from the second embodiment in that a large number of small heat radiation holes 8a are formed in the wall of the duct portion 8.
Is provided. With this configuration, the heat generated inside the case 7 and the heat of the large-current bus bar can be more efficiently radiated.

In the above embodiment, the high-current bus bar is arranged on the uppermost layer inside the case. However, the busbar is not necessarily limited to the uppermost layer. It may be projected to the second opening 5.

[0020]

As is apparent from the above description, according to the electric connection box of the present invention, the heat radiating portion formed by bending a part of the large current bus bar is provided on the upper surface of the upper case. Since it protrudes from the opening to the outside of the case, the heat generated inside the case and the heat generated in the high-current bus bar can be efficiently dispersed and radiated outside the case. Therefore, it is possible to prevent a rise in temperature inside the case without retaining the above-mentioned heat inside the case, and it is possible to eliminate a risk of malfunction of an electric circuit due to a rise in temperature inside the case.

When the duct portion is provided to extend from the periphery of the opening, the insulation of the heat radiating portion of the large current bus bar protruding to the outside of the case can be maintained well, and adhesion of dust and the like can be prevented.

Further, when a large number of small heat radiation holes are provided in the wall of the duct portion, the heat generated in the bus bar and the heat generated in the case can be more efficiently radiated to the outside of the case.

[Brief description of the drawings]

FIG. 1 is a partial schematic cross-sectional view of an electric junction box according to a first embodiment of the present invention.

FIG. 2 is a partial schematic cross-sectional view of an electric junction box according to a second embodiment of the present invention.

FIG. 3 is a perspective view of a main part of FIG. 2;

FIG. 4 is a perspective view of a main part showing a third embodiment of the present invention.

FIG. 5 is a schematic sectional view showing a conventional electric junction box.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lower case 2 Upper case 3a, 3b Bus bar 3c Bus bar for large current 4a, 4b Insulating plate 5 Opening 6 Heat radiating part 8 Duct part 8a Small heat radiating hole 9 Heat radiating opening 10 Upper cover

Claims (5)

[Claims] 1. An electric connection box in which a bus bar and an insulating plate are laminated and arranged inside a case formed by combining a lower case and an upper case, and an upper cover is placed on the upper case. And an electric connection box in which a heat radiating portion is provided by projecting a part of the large current bus bar housed inside the case, and the heat radiating portion of the bus bar is projected through the opening. 2. The electric connection box according to claim 1, wherein the heat radiating portion of the high-current bus bar protrudes into an upper cover that covers the upper case. 3. A duct portion protrudes from a peripheral edge of the opening,
The electrical junction box according to claim 1, wherein a heat radiation port is provided on a side surface on a distal end side of the duct portion, and a heat radiation portion of the bus bar projects from the duct portion. 4. The electric junction box according to claim 3, wherein a large number of small holes for heat radiation are provided in the wall of the duct portion. 5. The electric junction box according to claim 1, wherein the high-current bus bar is disposed on an uppermost layer inside the case.