JP2010241223A - Heat radiation structure for electric connection box - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To attain heat release of the whole of the inside of an electric connection box at low cost by convecting the whole of air in the electric connection box to exchange it with air in a reinforcement. <P>SOLUTION: The electric connection box is arranged at a lower side relative to the reinforcement and is fixed, a ventilation hole surrounded by a cylinder part for communicating the reinforcement with the inside of the box is formed on the electric connection box, and the cylinder part of the ventilation hole is inserted to the reinforcement. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a heat dissipation structure for an electrical junction box that is assembled to a reinforcement such as an automobile.

  As shown in FIG. 5, the conventional heat dissipation structure includes a reinforcement 10, a case 11 assembled to the reinforcement 10, and a semiconductor switch 12 attached to the case 11. A heat radiating plate 13 for dissipating the generated heat protrudes from the semiconductor switch 12, and the semiconductor switch 12 is installed adjacent to the reinforce 10. A fluid having a temperature lower than the temperature of the semiconductor switch 12 is generated in the reinforce 10. It is known that the temperature of the semiconductor switch 12 is configured to be maintained at a low temperature (see Patent Document 1). The heat radiating plate 13 protruding from the inside of the electric connection box 14 to the semiconductor switch 12 is exposed to the outside, the metal heat radiating plate 13 is located in the reinforcement 10, and the electric connection box 14 is made into the reinforcement 10 by the bracket 15. It is fixed.

JP 2003-219537 A

  In the conventional example disclosed in Patent Document 1, a semiconductor component (switch) is disposed outside the electrical junction box, and a heat sink provided in the switch is protruded into the reinforcement, and the air that has flowed into the reinforcement is used. This is not to cool the switch through the heat sink, but to convect the air in the electrical connection box and send the hot air in the box to the reinforcement to dissipate the heat in the box. Therefore, even if only the heat sink fixed to the semiconductor component (switch) and protruded into the reinforcement is cooled by the air in the reinforcement, the entire hot air inside the electrical junction box cannot be radiated. . Further, as the number of on-board systems increases, the number of circuits accommodated in the electrical junction box responsible for power distribution increases, and the temperature rise inside the electrical junction box increases due to the heat generated by the fuses and relays and the circuit itself. On the other hand, in order to accommodate many systems in the vehicle, the electrical junction box is also required to be downsized. Although it is possible to downsize the electrical junction box using a special cooling device such as a heat pipe, there is a problem that the cost increases.

  In addition, in the present automobile, as the in-vehicle system increases, the number of circuits accommodated in the electrical connection box 1 responsible for power distribution increases, and the temperature rise in the box increases due to the heat generated by the fuse, relay, and circuit itself. . On the other hand, in order to accommodate many systems in the vehicle, it is required to reduce the size of the electrical junction box. However, if the size is reduced by using a special cooling device, there is a disadvantage that the cost increases. And since the shape is complicated, the electrical junction box 1 is plastic-molded from the viewpoint of cost. In the case of a plastic case, there is a disadvantage that the temperature inside the case rises due to the low thermal conductivity of the case, inside, and outside air, and there is an increasing need for heat dissipation in the case.

  Accordingly, an object of the present invention is to radiate heat in the entire electrical connection box at low cost by convection of the entire air in the electrical connection box and replacing it with air in the reinforcement.

  In order to achieve the above-mentioned object, the present invention forms and arranges a vent hole surrounded by a cylindrical portion that communicates the reinforcement and the inside of the box with the electrical connection box arranged and fixed to the reinforcement downward. The cylindrical portion of the ventilation hole is inserted into the reinforcement.

  In addition, an electrical junction box is disposed below and fixed to the reinforcement, and a first air passage for feeding the air in the reinforcement into the electrical junction box between the reinforcement and the electrical junction box, A second air passage for sending the air in the junction box into the reinforcement, and the opening end on the reinforcement side of the first air passage is located lower than the opening end on the reinforcement side of the second air passage As described above, the first and second air passages are connected to the reinforcement, and the inside of the electrical junction box is radiated by convection of the air in the electrical junction box and replacing the air in the reinforcement. is there. In addition, a shielding member is provided at a location inside the reinforcement where the first ventilation path and the second ventilation path communicate with the reinforcement, respectively, and the reinforcement communication location between the first passage and the second passage is separated.

  According to the present invention, an electric connection box is disposed and fixed below the reinforcement, and a ventilation hole surrounded by a cylinder portion that allows the reinforcement to communicate with the inside of the box is formed in the electric connection box. Is inserted into the reinforce, so that the heat accumulated in the electrical junction box is efficiently dissipated, and the structure is simple and advantageous in terms of cost. In particular, the heat can be radiated using the reinforcement without a significant design change for radiating heat such as disposing the high temperature portion outside the electric junction box.

  In the present invention, the electric connection box is disposed below and fixed to the reinforce, and the first ventilation for sending the air in the reinforce into the electric connection box between the reinforce and the electric connection box. A second air passage for sending air in the electrical junction box into the reinforcement, and the opening end on the reinforcement side of the first air passage is lower than the opening end on the reinforcement side of the second air passage The first and second air passages are connected to the reinforce so as to be disposed at the position, and the inside of the electric connection box is radiated by replacing the air in the reinforce with the convection of the air in the electric connection box. As a result, the heat dissipation effect is further enhanced.

FIG. Sectional drawing which shows suitable embodiment of this invention. Sectional drawing which shows other embodiment of this invention. Sectional drawing which shows another embodiment of this invention. The perspective view which shows a prior art example.

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

  FIG. 1 shows the overall appearance, in which an electrical junction box 1 is arranged below and fixed to a reinforcement 10. FIG. 2 shows a cross-section of the connection point between the reinforcement 10 and the electrical junction box 1, and the cylindrical portion 3 forming the ventilation hole 2 is inserted into the opening 10 </ b> A opened in the reinforcement 10, and the interior 10 of the reinforcement and the electrical junction box 1 are inserted. The interior 1A is communicated.

  The fluid sent into the reinforce 10 is wind sent from an air conditioning device of an automobile, and the reinforce 10 may also serve as a duct through which this wind is circulated. In the case of an automobile, an instrument panel is assembled to the reinforcement 10. Although it is possible to radiate heat in the electrical junction box and reduce the size of the box using a special cooling device such as a heat pipe, the cost increases, so it is not adopted in the present invention. The opening area of the ventilation hole 2 may be very small as compared with a large opening from which a conventional heat radiating plate protrudes (Patent Document 1). This means that water droplets may enter the electrical connection box 1 at a large opening and short circuit, whereas the ventilation hole 2 having a small opening reduces the risk of water droplets entering.

  FIG. 3 shows another embodiment. The electrical connection box 1 is arranged below the reinforcement 10 in the same manner as described above, and the reinforcement 10 is between the reinforcement 10 and the electrical connection box 1. A first air passage 4 for sending the air inside the electric connection box 1 into the interior 1A and a second air passage 5 for sending the air inside the electric connection box 1 into the reinforcement 10 are provided. A cylindrical portion 4A for communicating the first air passage 4 with the reinforcement 10 via the opening 10A and a cylindrical portion 5A for communicating the second air passage 5 with the reinforcement 10 via the opening 10A are arranged concentrically. is there. The lower part of the cylindrical part 5A is formed so as to extend along the outer shape of the electric junction box 1, so that it becomes a double box, and the outer space 1B and the inner part 1A communicate with each other through a hole or the like. .

  The opening end on the reinforcement 10 side of the first air passage 4 is disposed at a position lower than the opening end on the reinforcement side of the second air passage 5. That is, the cylinder part 4A is lower than the cylinder part 5A. Since the space 1B following the first air passage 4 and the interior 1A of the electric junction box 10 following the second air passage 5 are in communication with each other, the air in the electric junction box 1 is convected, and the inside of the reinforcement 10 It is possible to dissipate heat in the electrical junction box 1 by replacing the air.

  In another embodiment shown in FIG. 4, an example in which the first air passage 4 and the second air passage 5 are separated from each other is shown. The electrical connection box 1 is disposed below the reinforcement 10, and a first air passage (duct) is provided between the reinforcement 10 and the electrical connection box 1 to send air in the reinforcement 10 into the interior 1 </ b> A of the electrical connection box 1. ) 4 is provided on one side of the electrical junction box 1, and the first air passage 4 communicates with the interior 1A (not shown). Air in the reinforcement 10 is sent from the first air passage 4 into the interior 1A of the electrical junction box 1, the temperature of the interior 1A is lowered, and the air in the interior 1A is sent out from the second air passage 5 into the reinforcement 10. The point that the cylinder part 4A is lower than the cylinder part 5B is the same as the embodiment of FIG. These cylindrical portions 4 </ b> B and 5 </ b> B protrude into the reinforcement 10 from the two openings 10 </ b> A of the reinforcement 10.

DESCRIPTION OF SYMBOLS 1 Electrical connection box 1A Interior 1B Space 2 Ventilation hole 3 Cylinder part 4 1st ventilation path 5 2nd ventilation path 4A, 5A Cylinder part 10 Reinforce 10A Opening 11 Case 12 Semiconductor switch 13 Heat sink 14 Electrical connection box

Claims (2)

Place and fix the electrical junction box below the reinforcement,
A ventilation hole surrounded by a cylindrical portion that allows the reinforcement to communicate with the inside of the box is formed in the electrical connection box,
A heat dissipation structure for an electrical junction box in which the cylindrical part of this ventilation hole is inserted into the reinforcement. Place and fix the electrical junction box below the reinforcement,
Between the reinforcement and the electrical junction box, a first air passage for sending air in the reinforcement into the electrical junction box, and a second air passage for sending air in the electrical junction box into the reinforcement Provided,
Connecting the first and second ventilation paths to the reinforcement so that the opening end on the reinforcement side of the first ventilation path is disposed at a position lower than the opening end on the reinforcement side of the second ventilation path;
A heat dissipation structure for an electrical junction box that radiates heat in the electrical junction box by convection of the air in the electrical junction box and replacing the air in the reinforcement.

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