JP5251618B2 - Heat dissipation structure for electrical junction box - Google Patents

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.

  In today's automobiles, as the number of in-vehicle systems increases, the number of circuits accommodated in an electrical junction box that handles power distribution increases, and the temperature inside the box increases due to heat generated by fuses, relays, and circuits themselves. 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. Since the shape is complicated, and from the viewpoint of cost, the electric junction box is molded with plastic. 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.

  The thing of patent document 1 is known as what performs the thermal radiation of an electrical junction box using a heat pipe. This is a base box for mounting electronic components, and an electric junction box with a heat pipe that dissipates heat generated from electronic components to the outside, with the heat absorbing portion side inside and the heat radiating portion side arranged outside. The box is provided with a conductive heat collecting member that collects the heat generated from the electronic components. The heat collecting member is connected to the heat absorption part of the heat pipe, and an earth current is passed between the heat pipe and the heat collecting member. A copper plate fixed to the heat radiation part side of the heat pipe is attached to the groove-shaped attachment part of the mounting bracket formed along the side wall of the base box and projecting outward in the width direction on the side wall. In this way, it is electrically connected to the vehicle body side to drop the ground current to the vehicle body.

JP 2007-151391 A

  In the thing of patent document 1, in order to provide a heat pipe for heat dissipation, parts increased, and it led to the raise of manufacture and assembly cost. Moreover, since it was made into the airtight structure for waterproofing, there also existed a problem that the temperature in an electrical junction box rose by the accumulation of air inside. Furthermore, since a resin-made main body case is used, an increase in internal temperature due to the low thermal conductivity of the case, the inside, and the outside air cannot be suppressed.

  An object of the present invention is to provide a heat dissipation structure for an electrical junction box that can efficiently radiate heat without using a heat pipe to efficiently cool the inside of the electrical junction box and can be downsized.

  In order to achieve the above-mentioned object, according to the present invention, an electrical junction box is disposed and fixed to a reinforcement downward via a metal bracket, both ends of the bracket are fixed to the reinforcement, and both ends of the bracket are connected. By passing the bracket connecting part through the inside of the electrical junction box and the bracket connecting part coming into contact with the inside of the electrical junction box, the heat inside the electrical junction box is dissipated from the reinforcement via the bracket. It is a thing.

  The electrical junction box is fixed to the bracket by forming a slit in the electrical junction box and inserting the bracket connection into this slit, or forming a lid on the top of the electrical junction box, and this lid is fixed. The connecting portion of the bracket is set so as to cross the opening at the upper portion of the electric connection box, and this connecting portion is fixed to the electric connection box with the lid portion.

  According to the present invention, the electrical junction box is disposed and fixed below the reinforcement via the metal bracket, and both ends of the bracket are fixed to the reinforcement, and the connecting portion of the bracket that connects both ends of the bracket is electrically connected. By passing through the inside of the connection box and the connecting part of this bracket comes into contact with the inside of the electrical connection box, the heat inside the electrical connection box is dissipated from the reinforcement through the bracket. There is no need to increase the number of parts, cost increase can be suppressed, and miniaturization can be achieved.

  When the slit is formed in the electrical junction box and the connecting portion of the bracket is inserted into the slit, it is easy to assemble. Also, a lid is formed at the top of the electrical junction box, and a bracket coupling is set across the opening at the top of the electrical junction box to which the lid is fixed. The junction is connected to the electrical junction box by the lid. In this case, the electrical connection box and the bracket are securely fixed.

The perspective view before fixation of an electric junction box. The perspective view after fixation. Sectional drawing at the time of penetration of a bracket. The perspective view which shows the other fixing method. Sectional drawing of the structure which aimed at waterproofing.

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

  In FIG. 1, a state immediately before fixing the electrical connection box 2 to the reinforcement 1 via the bracket 3 is shown, and continuous slits 4 are formed on both sides and the back of the electrical connection box 2. Is inserted into the electrical connection box 2 by being slid from the back side of the box 2 and fixed to the reinforcement 1. In FIG. 1, a cap 5 is attached to the slit 4 (the back surface of the electrical connection box 2) at an invisible position to prevent the bracket 3 from coming out of the electrical connection box 2 and to be waterproof.

  FIG. 2 shows a state in which the electrical junction box 2 is fixed to the reinforcement 1 via the bracket 3. Both ends 3 </ b> A of the bracket 3 are exposed to the outside, and the connecting portion 3 </ b> B connecting the both ends 3 </ b> A is in a state of penetrating the inside of the electrical connection box 2. The thickness of the slit 4 is formed to be slightly larger than the thickness of the bracket 3, and the gap is formed as small as possible so that water does not easily enter, and the back side is waterproofed by the cap 5.

  FIG. 3 is a cross-sectional view showing the location of the connecting portion 3B of the bracket 3 in the state of FIG. 2, and at this time, the upper surface of the electrical junction box 2 and the lower portion of the reinforcement 1 are brought into contact with or in close contact with each other. The electric junction box 2 can be directly cooled by the gas flowing in the reinforcement 1.

  The fluid flowing in the reinforcement 1 may be a fluid sent from an air conditioner. Since both ends 3A of the metal bracket 3 are fixed to the reinforcement 1, heat in the electric junction box 2 is transmitted from the connecting portion 3B of the bracket 3 to the reinforcement 1 through the both ends 3A. Heat is dissipated. And when it arrange | positions under the reinforcement 1 and the upper surface of the electrical junction box 2 is made to contact the lower part of the reinforcement 1, the heat | fever of the resin case itself of the electrical junction box 1 is radiated also in this contact part.

  FIG. 4 shows another embodiment, in which the upper part of the electrical connection box 2 is cut off to form a lid part 2A, the upper part becomes an opening part 2B, and the fitting notches 6 are formed on both sides of the opening part 2B. The connecting portion 3B of the bracket 3 is set (fitted) to the notch 6 so as to cross the opening 2B, and the lid portion 2A is fixed to the electrical junction box 2 from above the connecting portion 3B. The electric junction box 2 is fixed below the reinforcement 1 in a state where 3B is passed through the box 2.

  In FIG. 5, a groove portion 7 is formed between the both ends 3 </ b> A of the bracket 3 and the connecting portion 3 </ b> B, and water droplets are prevented from being collected in the groove portion 7 and entering the electric junction box 2. 4 and 5, the lid 2A is made of metal instead of resin, and the lid 2A is brought into contact with (contacted with) the reinforcement 1 so that the heat in the box 2 is transferred from the metal lid 2A to the reinforcement 1. It is possible to dissipate heat.

  In any of the above-described embodiments, the case main body of the electrical junction box 2 is formed by molding resin, and the reinforcement 1 and the bracket are formed of a material having good thermal conductivity. The reinforcement 1 is a long reinforcing member that supports various attachments such as a steering column and an instrument panel mounted on an automobile or the like and is applied with a load. The electrical junction box 2 houses various wiring boards, bus bars, semiconductor switches, and other electrical-related parts, and assembles a plurality of connectors, relays, fuses, etc., and parts that constitute a circuit from electric wires, etc. A block part in a closed state.

  It can be used for an electric junction box fixed to a reinforcement used in an automobile.

DESCRIPTION OF SYMBOLS 1 Reinforce 2 Electrical junction box 3 Bracket 3A Both ends 3B Connection part 4 Slit

Claims (4)

The electrical junction box is placed and fixed to the reinforcement through the metal bracket,
Fix both ends of the bracket to the reinforcement,
The bracket connecting part that connects both ends of the bracket passes through the inside of the electrical junction box,
A heat dissipation structure for an electrical junction box, wherein the connecting portion of the bracket comes into contact with the interior of the electrical junction box, whereby heat inside the electrical junction box is radiated from the reinforcement via the bracket.   The heat dissipation structure for an electrical junction box according to claim 1, wherein a slit is formed in the electrical junction box, and a connecting portion of a bracket is inserted into the slit.   Form a lid at the top of the electrical junction box, set the bracket coupling so that it crosses the opening at the top of the electrical junction box where the lid is fixed, and fix the junction to the electrical junction box with the lid The heat dissipation structure for an electrical junction box according to claim 1.   The heat dissipation structure for an electrical junction box according to claim 3, wherein the lid is made of metal and is brought into contact with reinforcement.

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