JP2010114962A - Electrical connection box - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrical connection box wherein the temperature of the interior of a case is suppressed from locally becoming too high. <P>SOLUTION: The electrical connection box 10 is provided with: the case 11; a fuse port 24, so provided that it is open in the upper wall of the case 11, through which a fuse 25 is installed; a terminal, provided in the fuse port 24, which can be electrically connected with the fuse 25; a circuit board 12 housed in the case 11 and electrically connected with the terminal; a ceiling wall 26 which is positioned under the port in the case 11 and covers the area positioned above the circuit board 12 and whose terminal is insert molded of a synthetic resin material; a heat radiation hole 35 so provided that it penetrates a side wall of the case 11; and an eaves 36 which is formed on the outer surface of the side wall of the case 11 so that it protrudes outward and covers the area positioned above the heat radiation hole 35. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electrical junction box.

2. Description of the Related Art Conventionally, an electric connection box mounted on a vehicle and energizing and de-energizing on-vehicle electrical components such as a lamp and a horn is disclosed in Patent Document 1. In this case, a circuit board on which electronic components are mounted is accommodated in a case. A fuse mounting portion in which a fuse can be mounted is opened on the upper wall of the case. A fuse terminal that is electrically connected to the fuse is accommodated in the fuse mounting portion. The fuse terminal extends inward of the case and is electrically connected to the circuit board. In the case, a wall portion for receiving water entering from the fuse attachment port is disposed at a position below the fuse attachment portion. This wall portion is formed by insert molding a fuse terminal with a synthetic resin material. Thus, the terminal and the synthetic resin are formed in a liquid-tight manner so that water that has entered the case from the fuse mounting opening does not reach the circuit board.
JP 2003-348732 A

  By the way, the heat generated in the circuit board and the electronic component by energizing the circuit board is transmitted to the air around the circuit board. When heat is transferred to the air, the density of the air becomes thin (small) and moves upward in the case. However, in the wall portion, the terminal and the synthetic resin are formed in a liquid-tight manner so that water that has entered the case from the fuse mounting opening does not reach the circuit board. For this reason, it is hindered that the heated air moves upward from the wall portion, and there is a concern that the heated air stays between the wall portion and the circuit board. Then, there is a concern that heat accumulates in the case and locally becomes high temperature. If the inside of the case becomes locally high in temperature, there may be a problem that, for example, an electronic component mounted on the circuit board malfunctions or a solder connection portion of the electronic component is cracked due to thermal stress.

  This invention is completed based on the above situations, Comprising: It aims at providing the electrical junction box by which the inside of a case was suppressed from becoming high temperature locally.

  The present invention is an electrical junction box, comprising a case, an opening provided in an upper wall of the case and capable of mounting a counterpart member, and an electrical connection box disposed in the attachment port and electrically connected to the counterpart member. A terminal that can be connected electrically, a circuit board that is housed in the case and electrically connected to the terminal, and is disposed at a position below the mounting opening in the case and of the circuit board A ceiling wall that covers the top and is formed by insert molding of the terminal with a synthetic resin material, a heat radiating port provided through the side wall of the case, and an outer surface of the side wall of the case project outward. And a ridge that covers the upper side of the heat radiating port.

  According to the present invention, the heat generated in the circuit board by energizing the circuit board is dissipated to the outside of the case from the heat radiation port provided through the side wall of the case. Thereby, it can suppress that heat is trapped in a case.

  Moreover, since the upper side of the heat radiation port is covered with the ridge, it is possible to suppress the water flowing down the outer surface of the side wall of the case from entering the case from the heat radiation port.

As embodiments of the present invention, the following embodiments are preferable.
A cover wall that hangs downward and covers the heat radiating port from the outside in the thickness direction of the side wall of the case may be formed at the edge of the flange.

  According to said structure, it can suppress that water penetrate | invades in a case through a radiation opening from the thickness direction outer side of the side wall of a case.

  The ceiling wall may be provided with an extending wall extending in the vertical direction. A bus bar may be embedded in the extending wall, and the bus bar may be disposed at a position corresponding to the heat radiation port.

  According to said structure, the heat which generate | occur | produces from a bus bar when it supplies with electricity to a bus bar is efficiently dissipated out of a case from the thermal radiation port distribute | arranged to the position corresponding to a bus bar.

  The extending wall is disposed between the heat radiation port and the circuit board in the case, and the extending wall is formed with a first through hole penetrating the extending wall. In the bus bar, a second through hole penetrating the bus bar may be formed at a position corresponding to the first through hole.

  According to said structure, the heat which generate | occur | produced in the circuit board by supplying with electricity to a circuit board is dissipated out of a case from a thermal radiation port through a 1st through-hole and a 2nd through-hole. Thereby, it can further suppress that heat is trapped in the case.

  The upper surface of the ceiling wall is formed with an inclined surface that is inclined downward toward the edge of the ceiling wall, and the side wall of the case is positioned at a position corresponding to the lower end edge of the inclined surface. A drainage hole penetrating the side wall may be formed.

  According to said structure, the water which infiltrated from the mounting opening flows down on the inclined surface formed in the upper surface of a ceiling wall. Thereafter, the water flows down the inclined surface and reaches the lower end edge of the inclined surface. The water that has reached the lower end edge of the inclined surface is discharged to the outside of the case through a drain outlet that penetrates the side wall of the case. Thereby, it can suppress that the water which infiltrated from the mounting opening flows into the circuit board arrange | positioned under the ceiling wall.

  The drain port may also serve as the heat radiating port.

  According to said structure, an opening part can be decreased compared with the case where both a drain port and a heat radiating port are provided in the side wall of a case. As a result, the intrusion of water into the case can be suppressed, and the waterproofness of the case can be improved.

  According to the present invention, it is possible to suppress the heat generated in the circuit board from being trapped in the case.

  An embodiment in which the present invention is applied to an electrical junction box 10 mounted on a vehicle (not shown) will be described with reference to FIGS. The electrical junction box 10 according to the present embodiment includes a circuit board 12 accommodated in a case 11. The electrical connection box 10 is arranged between a power source (not shown) and on-vehicle electrical components (not shown) such as a lamp and a horn, and performs energization and non-energization on the on-vehicle electrical components. . In the following description, the upper side in FIG. 1 is the upper side, and the lower side is the lower side. Further, the right side in FIG. 1 is the right side, and the left side is the left side. Further, the right side in FIG. 4 is the back side, and the left side is the front side.

(Case 11)
As shown in FIG. 4, the case 11 includes a first case 13 located on the back side (right side in FIG. 4), a second case 14 located on the front side (left side in FIG. 4), and the first case 13 in a state assembled with each other. And a cover 15 assembled on the upper side of the first case 13 and the second case 14.

  As shown in FIG. 4, the 1st case 13 insert-molds the metal heat sink 16 with a synthetic resin material, and has comprised the shallow dish shape opened to the front side (left side in FIG. 4). The space between the heat sink 16 and the synthetic resin material is liquid-tight. The heat radiating plate 16 is exposed on the front side surface of the first case 13 and is also exposed on the back side (right side in FIG. 4). The upper end portion of the heat radiating plate 16 is bent at a substantially right angle and protrudes toward the back side.

  The circuit board 12 is accommodated in the opening of the first case 13 and is screwed with a screw (not shown). The circuit board 12 may be adhered to the first case 13 with an adhesive or an adhesive sheet, and is engaged with an engaging portion (not shown) provided in the first case 13. Therefore, it may be assembled to the first case 13 or can be assembled to the first case 13 by any means.

  As shown in FIG. 4, the second case 14 is made of a synthetic resin and has a shallow dish shape that opens on the back side (the right side in FIG. 4). As shown in FIG. 3, the first case 13 and the second case 14 are arranged from the front side (upper side in FIG. 3) with respect to the first case 13 with the circuit board 12 assembled in the first case 13. A plurality of lock portions 17 provided on the side wall of the first case 13 with the two cases 14 approached, and a lock receiving portion 18A provided at a position corresponding to the lock portion 17 on the side wall of the second case 14; Are assembled by elastically engaging them.

  As shown in FIG. 4, the cover 15 is made of a synthetic resin and has a shallow dish shape that opens downward (downward in FIG. 4). As shown in FIG. 2, the cover 15 is made to approach the first case 13 and the second case 14 from above (the upper side in FIG. 2) after the first case 13 and the second case 14 are assembled as described above. Then, the plurality of lock portions 17 provided on the side wall of the first case 13 and the lock receiving portion 18B provided at a position corresponding to the lock portion 17 on the side wall of the cover 15 are elastically engaged. It is assembled by. The cover 15 covers the boundary portion between the first case 13 and the second case 14 from above in a state where the first case 13 and the second case 14 are assembled.

(Circuit board 12)
The circuit board 12 is formed by forming a conductive path (not shown) on an insulating substrate by a printed wiring technique. As shown in FIG. 4, an electronic component 19 such as a relay is mounted on the front side (left side in FIG. 4) of the circuit board 12 by a known method such as soldering. The circuit board 12 is provided with metal connector terminals 20 penetrating in the front-back direction (left-right direction in FIG. 4). The connector terminal 20 is electrically connected to the conductive path of the circuit board 12 by a known method such as soldering. An end of the front side (left side in FIG. 4) of the connector terminal 20 is bent downward (downward in FIG. 4) and is disposed in a connector housing 21 made of synthetic resin.

  As shown in FIG. 4, the connector housing 21 opens downward (downward in FIG. 4), and can be fitted to a mating connector (not shown). An end portion located on the front side of the connector terminal 20 is located in the opening of the connector housing 21 and can be electrically connected to the mating connector. Although not shown in detail, the connector housing 21 is screwed to the circuit board 12 with screws (not shown). Further, the connector housing 21 is disposed in a connector housing portion 22 that is provided in the lower end portion of the case 11 so as to open downward.

(Fuse 25 mounting structure)
As shown in FIG. 4, a metal fuse terminal 23 (corresponding to the terminal described in the claims) is located in the front and back direction (left and right direction in FIG. 4) at a position near the upper end of the circuit board 12. It is arranged through. The fuse terminal 23 is electrically connected to the conductive path of the circuit board 12 by a known method such as soldering. An end of the front side (left side in FIG. 4) of the fuse terminal 23 is bent upward (upward in FIG. 4), and a fuse mounting port 24 provided in the cover 15 (in the mounting port described in the claims). Equivalent).

  As shown in FIG. 4, a fuse mounting opening 24 in which a fuse 25 (corresponding to the counterpart member described in the claims) can be mounted is formed on the upper wall of the cover 15 in the vertical direction (vertical direction in FIG. 4). An opening is formed. The end portion located on the front side of the fuse terminal 23 is arranged in the opening of the fuse mounting opening 24 and is formed to be bifurcated to sandwich the lead terminal 27 of the fuse 25. Thus, it can be electrically connected to the fuse 25 (see FIG. 5).

  As shown in FIG. 4, the fuse terminal 23 is insert-molded with a synthetic resin material. The fuse terminal 23 that is insert-molded with a synthetic resin material is disposed at a position below the fuse mounting opening 24 of the cover 15 and serves as a ceiling wall 26 that covers the circuit board 12 from above. In the ceiling wall 26, the space between the fuse terminal 23 and the synthetic resin material is liquid-tight.

(Drainage structure)
As shown in FIG. 4, an inclined surface 28 is formed on the upper surface of the ceiling wall 26. The inclined surface 28 is inclined downward toward the edge on the front side (left side in FIG. 4) of the ceiling wall 26. A drain port 29 that penetrates the side wall of the second case 14 is formed on the side wall of the second case 14 at a position corresponding to the lower edge of the inclined surface 28.

(Heat dissipation structure)
As shown in FIG. 4, an extending wall 30 extending in the vertical direction (vertical direction in FIG. 4) is formed at a position near the front side (left side in FIG. 4) of the ceiling wall 26. In the present embodiment, the extension wall 30 is formed to hang downward from the lower surface of the ceiling wall 26. As shown in FIG. 5, a bus bar 31 is embedded in the extending wall 30 by insert molding with a synthetic resin material. The bus bar 31 extends in the left-right direction (left-right direction in FIG. 5). From the upper edge of the bus bar 31, a plurality of fuse connection portions 32 are formed protruding upward. The fuse connecting portion 32 is disposed in the fuse mounting opening 24 of the cover 15. The front end of the fuse connection portion 32 is divided into two portions, and can be electrically connected to the fuse 25 by sandwiching the lead terminal 27 of the fuse 25.

  As shown in FIG. 5, a power supply terminal 33 is formed at the right end edge of the bus bar 31 so as to hang downward and be electrically connected to a power supply (not shown). The power terminal 33 is disposed in a power connector housing portion 34 that is formed to hang downward from the ceiling wall 26 and open downward. A power connector (not shown) can be fitted in the power connector housing portion 34, and the power terminal 33 can be electrically connected to the power source by connecting to the power connector. .

  As shown in FIG. 4, a heat radiation port 35 penetrating the side wall of the second case 14 is formed on the side wall of the second case 14 at a position corresponding to the bus bar 31. As shown in FIG. 1, the heat radiation port 35 is formed on the side wall of the second case 14 so as to extend in the left-right direction (left-right direction in FIG. 1). In the present embodiment, the drainage port 29 also serves as the heat radiation port 35.

  As shown in FIG. 4, the outer surface of the side wall of the second case 14 protrudes outward (in the left direction in FIG. 4) in the thickness direction of the side wall of the second case 14 at a position above the heat radiation port 35. A flange 36 is formed. A cover wall 37 is formed at the edge of the flange 36 so as to hang downward and cover the heat radiation port 35 from the outside in the thickness direction of the side wall of the case 11 (left side in FIG. 4). As shown in FIG. 1, the cover wall 37 covers the heat radiation port 35 over the entire region in the left-right direction (left-right direction in FIG. 1).

  As shown in FIG. 4, the extension wall 30 is disposed between the heat radiation port 35 and the circuit board 12 in the case 11. The extension wall 30 is formed with a first through hole 38 that penetrates the extension wall 30.

  In the first through hole 38, the hole edge on the front side (left side in FIG. 4) is set smaller than the hole edge on the back side (right side in FIG. 4). As shown in FIG. 6, a plurality of (four in the present embodiment) first through holes 38 are formed side by side in the left-right direction (left-right direction in FIG. 6). The hole edge on the front side of the first through hole 38 has a rectangular shape. Moreover, as shown in FIG. 7, the hole edge on the back side of the first through hole 38 has a substantially rectangular shape with rounded corners.

  As shown in FIG. 4, a plurality of (four in the present embodiment) second through holes 39 penetrating the bus bar 31 are formed at positions corresponding to the first through holes 38 in the bus bar 31. As shown in FIGS. 6 and 7, the hole edge of the second through hole 39 has a rectangular shape, and has substantially the same shape as the hole edge on the front side of the first through hole 38.

  Then, the effect | action and effect of this embodiment are demonstrated. According to this embodiment, the heat generated in the circuit board 12 and the electronic component 19 by energizing the circuit board 12 is dissipated to the outside of the case 11 from the heat radiation port 35 provided through the side wall of the case 11. The Thereby, it is possible to suppress heat from being trapped in the case 11. As a result, since it is possible to suppress thermal stress from being applied to the connection portion between the electronic component 19 and the circuit board 12, problems such as cracks occurring at the connection portion between the electronic component 19 and the circuit board 12 occur. This can be suppressed.

  Moreover, since the upper side of the heat radiation port 35 is covered with the flange 36, it is possible to prevent water flowing down the outer surface of the side wall of the case 11 from entering the case 11 from the heat radiation port 35.

  Further, according to the present embodiment, the cover wall 37 is formed on the edge of the flange 36 so as to hang downward and cover the heat radiation port 35 from the outside in the thickness direction of the side wall of the case 11. Thereby, it is possible to prevent water from entering the case 11 through the heat radiation port 35 from the outside in the thickness direction of the side wall of the case 11.

  Further, according to the present embodiment, the ceiling wall 26 is provided with the extending wall 30 extending in the vertical direction, and the bus bar 31 is embedded in the extending wall 30, and the bus bar 31 has the heat radiation port 35. It is arranged at the position corresponding to. Thus, heat generated from the bus bar 31 when the bus bar 31 is energized is efficiently dissipated out of the case 11 from the heat radiation port 35 disposed at a position corresponding to the bus bar 31.

  Further, according to the present embodiment, the extension wall 30 is disposed between the heat radiation port 35 and the circuit board 12 in the case 11, and the extension wall 30 is provided with the extension wall 30. A first through hole 38 that penetrates is formed, and a second through hole 39 that penetrates the bus bar 31 is formed in the bus bar 31 at a position corresponding to the first through hole 38. Thereby, the heat generated in the circuit board 12 and the electronic component 19 by energizing the circuit board 12 is dissipated out of the case 11 from the heat radiation port 35 through the first through hole 38 and the second through hole 39. Thereby, it can further suppress that heat is trapped in the case 11.

  Further, according to the present embodiment, the inclined surface 28 is formed on the upper surface of the ceiling wall 26 so as to be inclined downward toward the edge of the ceiling wall 26, and the lower end of the inclined surface 28 is formed on the side wall of the case 11. A drainage port 29 penetrating the side wall of the case 11 is formed at a position corresponding to the edge. Thereby, the water that has entered from the fuse mounting opening 24 flows down on the inclined surface 28 formed on the upper surface of the ceiling wall 26. Thereafter, the water flows down the inclined surface 28 and reaches the lower end edge of the inclined surface 28. The water that has reached the lower end edge of the inclined surface 28 is discharged to the outside of the case 11 through a drain outlet 29 that penetrates the side wall of the case 11. Thereby, it is possible to suppress the water that has entered from the fuse mounting opening 24 from flowing into the circuit board 12 disposed below the ceiling wall 26.

  Further, in the present embodiment, the heat radiation port 35 is formed to extend in the left-right direction (left-right direction in FIG. 1) on the side wall of the second case 14, so that heat is more easily dissipated from within the case 11. It has become.

  Further, according to the present embodiment, the drain port 29 also serves as the heat radiating port 35. Thereby, compared with the case where both the drain outlet 29 and the thermal radiation port 35 are provided in the side wall of the case 11, an opening part can be decreased. As a result, water intrusion into the case 11 can be suppressed, so that the waterproofness of the case 11 can be improved.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.
(1) For example, in the case where the boundary portion between the first case 13 and the second case 14 in a state where the first case 13 and the second case 14 are assembled is not located on the upper surface of the case 11, The cover 15 can be omitted. In this case, the fuse mounting opening 24 can be provided on one of the upper wall of the first case 13 and the upper wall of the second case 14.
(2) In the present embodiment, a relay is used as the electronic component 19. However, the present invention is not limited to this, and any electronic component 19 such as a semiconductor relay or a resistor can be used as the electronic component 19.
(3) The first through hole 38 and the second through hole 39 may be one, or may be two, three, or a plurality of five or more.
(4) In the present embodiment, the cover wall 37 is formed on the flange 36, but the cover wall 37 may be omitted.
(5) In the present embodiment, the extended wall 30 is provided on the ceiling wall 26, but the extended wall 30 may be omitted.
(6) In the present embodiment, the counterpart member is the fuse 25. However, the fuse member 25 is not limited to this. For example, a connector may be used, and any member can be used as the counterpart member as necessary.

Front view showing an electrical junction box according to the present embodiment Exploded perspective view showing electrical junction box The exploded perspective view which shows the state before attaching the 2nd case to the 1st case which attached the circuit board. IV-IV line sectional view in FIG. Sectional drawing which shows the state by which the bus-bar is embed | buried in the extension wall Front view showing the ceiling wall Rear view showing the ceiling wall

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Electrical junction box 11 ... Case 12 ... Circuit board 13 ... 1st case (case)
14 ... Second case (case)
15 ... Cover (case)
23 ... Terminal for fuse (terminal)
24 ... Fuse mounting port (mounting port)
25 ... Fuse (mating member)
26 ... Ceiling wall 28 ... Inclined surface 29 ... Drainage port 35 ... Heat radiation port 36 ... ３７ 37 ... Cover wall 38 ... First through hole 39 ... Second through hole

Claims (6)

A case, a mounting opening provided in the upper wall of the case and capable of mounting a mating member; a terminal disposed in the mounting port and electrically connectable to the mating member; A circuit board that is electrically connected to the terminal, and is disposed at a position below the mounting opening in the case, covers the circuit board, and the terminal is made of synthetic resin. A ceiling wall formed by insert molding with a material, a heat radiating port provided through the side wall of the case, and an outer surface of the side wall of the case formed to protrude outward and above the heat radiating port. An electrical junction box comprising a covering gutter. 2. The electrical junction box according to claim 1, wherein a cover wall is formed on an end edge of the flange, the cover wall hanging downward and covering the heat radiating port from the outside in the thickness direction of the side wall of the case. The said ceiling wall is provided with the extended wall extended in an up-down direction, The bus bar is embed | buried under the said extended wall, The said bus bar is distribute | arranged to the position corresponding to the said heat radiating port. Or the electrical junction box of Claim 2. The extending wall is disposed between the heat radiation port and the circuit board in the case, and the extending wall is formed with a first through hole penetrating the extending wall. The electrical connection box according to claim 3, wherein the bus bar has a second through hole penetrating the bus bar at a position corresponding to the first through hole. The upper surface of the ceiling wall is formed with an inclined surface that is inclined downward toward the edge of the ceiling wall, and the side wall of the case is positioned at a position corresponding to the lower end edge of the inclined surface. The electrical junction box according to any one of claims 1 to 4, wherein a drain outlet penetrating the side wall is formed. The electrical junction box according to claim 5, wherein the drain port also serves as the heat radiating port.

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