JP2012100476A - Electrical connection box - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrical connection box in which the flow of air is smooth for improved heat dissipation characteristics, with entrance of water being prevented.SOLUTION: An electrical connection box 10 includes a case 11 which has air flow outlets 12A and 13A on an upper wall, a circuit board 20, and a holding member 30 which holds the circuit board 20 and partitions a space in the case 11 into a substrate housing space K1 and another space K2. The holding member 30 is provided with a first ventilation opening 43 which allows communication between the substrate housing space K1 and another space K2 in the case 11. A common distribution path 15 is provided in another space K2 in the case 11, which acts as a ventilation path for ventilating the air in the case to down the air flow outlet 12A, and also acts as a drain path for discharging the water entering from the air flow outlets 12A and 13A. In the common distribution path 15, at least one second ventilation opening 55 is formed at a position that does not form a straight line with the first ventilation opening 43 and the air flow outlets 12A and 13A, above the first ventilation opening 43.

Description

  The present invention relates to an electrical junction box.

  As an electrical junction box for energizing and disconnecting an in-vehicle electrical component, there is a case in which a circuit board on which an electronic component such as a relay is mounted is accommodated in a case.

  In recent years, electrical connection boxes have been required to be smaller and higher in density. In the electrical junction box, the number of electronic components accommodated in the case has increased with higher functionality, and the mounting space of the electrical junction box has become narrower due to the increase in the number of mounted components, etc. While the amount of heat generated from electronic components increases, the volume of the case tends to decrease.

  Therefore, in an electrical junction box that meets the demands for miniaturization and high density, the heat generation density is high, and heat generated from electronic components tends to stay in the case, causing the case to become hot. There is a possibility that the performance of the electronic component housed in the case may deteriorate.

  In order to discharge the heat generated in the case to the outside, it is conceivable to provide an opening on the upper surface of the case. However, for example, when the electrical junction box is housed in the engine room of a vehicle, if water falls on the electrical junction box during rainfall or car wash, the opening is provided on the top surface of the case. There is concern about the ingress of water.

  In view of this, an electrical junction box described in Patent Document 1 has been proposed as a solution to the above problem.

JP 2010-22161 A

  Patent Document 1 proposes a ventilation structure that radiates heat generated by a circuit board on which a relay is mounted and prevents water from entering the board.

  The electrical junction box is provided with a water blocking wall that prevents water from entering the circuit board and has an inclined surface formed on the upper frame portion that covers the circuit board. When water enters from the opening (for example, the fuse mounting hole), the intruded water is prevented from entering the circuit board by the water blocking wall, and flows down the inclined surface of the upper frame portion covering the circuit board. (See FIG. 3 of Patent Document 1).

  However, in the electrical junction box, the air heated by the heat generated by the relay moves up the case and hits the upper wall of the case, and then is guided downward by the case side wall through the ventilation gap. Then, it comes out from the upper opening part (refer FIG. 11 of patent document 1). That is, in the electrical junction box, there is a problem that smooth ventilation is hindered because the warmed air is guided downward while being discharged to the outside of the case.

  The present invention has been completed based on the above circumstances, and an object thereof is to provide an electrical junction box that improves heat dissipation by making air flow smooth and prevents water from entering. And

  In order to solve the above problems, the present invention provides a case having an air outlet on the upper wall through which internal air can flow out, a circuit board accommodated in the case, and a circuit board surface of the circuit board. And holding the circuit board and partitioning the space inside the case into a board housing space in which the circuit board is housed and a space other than the board housing space. A first ventilation port that communicates the substrate housing space and the other space in the case, and is disposed in the other space in the case. There is provided a common flow path that serves both as a ventilation path for venting the air in the case to the air outlet and a drainage path for draining water flowing in from the air outlet, and the common flow path includes the first flow path. The first above the vent. A position not aligned to outlet port and the air outlet and a straight line, a second vent port communicating with said first vent is an electrical connection box, characterized in that it is formed one or more.

  In the present invention, the air in the board housing space in which the circuit board is arranged passes through the first vent formed in the holding member, moves to another space, and then the second vent formed in the common flow passage. Is exhausted from the air outlet through the common flow passage. Here, since the second vent is formed above the first vent and the air outlet is formed on the case upper wall above the second vent, the air in the substrate housing space is smoothly It is guided upward and discharged out of the case.

  On the other hand, in the present invention, when water flows into the air outlet formed in the upper wall of the case, the water flowing in from the air outlet flows into the common flow path arranged in the other space of the holding member in the case, and then Drained out of the case. In other words, in the present invention, the water flowing in from the air outlet is drained outside the case after flowing into the common flow path arranged in the space (other space) opposite to the substrate housing space. It is difficult for water to enter the substrate.

Here, for example, even if the water flowing in from the air outlet has entered the second vent formed in the common flow path due to the inclination of the entire electrical junction box, the second vent is connected to the first vent and the air. Since it is formed at a position that does not line up with the outflow port, the water that has entered the second vent hole is unlikely to move toward the first vent port, so that the water will not enter the board housing space (circuit board side). Intrusion can be prevented.
As a result, according to the present invention, it is possible to provide an electrical junction box that has a smooth air flow to improve heat dissipation and prevent water from entering.

The present invention may have the following configurations.
An air inlet for introducing air from the outside of the case into the case may be formed at the lower end of the holding member. With such a configuration, since the air flow in the case becomes smooth, heat dissipation can be further improved.

  A concave portion projecting downward may be formed on the upper wall of the case, and the air outlet may be formed on a side wall of the concave portion. With such a configuration, water is less likely to flow in than the air outlet opening upward, so that the effect of preventing water entry is enhanced. In the above configuration, the common flow passage has a cylindrical side wall portion extending downward, and the side wall portion serves as a side wall of the recess portion and is provided adjacent to the recess portion. Since the outflow port is formed in the side wall portion of the common flow passage, the structure can be simplified.

The common flow passage has a cylindrical shape extending downward, and a lower end thereof is opened. The holding member is formed with a partition wall that partitions the substrate housing space from the other space. A second drainage channel having an inclined surface that is disposed below the lower end portion of the common flow passage and is inclined downward as the distance from the lower end portion of the common flow passage is formed on the surface on the other space side. It may be.
With such a configuration, the water flowing in from the air outlet flows through the common flow passage, and then flows through the inclined surface inclined downward of the second drainage channel to be drained outside the case. It drains promptly without accumulating.

  In the above configuration, when a water stop wall is formed at the upper end of the inclined surface up to a position above the lower end portion of the common flow path and prevents water from entering the substrate housing space, Even if water splashes from the lower end portion of the common flow passage due to the inclination of the electric junction box, the water blocking wall can prevent water from entering the substrate housing space.

  In the above configuration, when the first vent is provided at a position above the lower end of the common flow path of the water blocking wall, not only prevents the water from entering the substrate housing space, One vent can be arranged in the vicinity of the common flow path, so that the air vented from the first vent passes through the common flow path from the second vent or the opening at the lower end of the common flow path. The air is quickly exhausted from the air outlet. As a result, water can be prevented from entering the substrate housing space, and the heat dissipation can be further enhanced.

  In the above configuration, when the end surface of the lower end portion of the common flow passage is formed so as to be inclined downward as it is away from the first vent, the direction in which water flowing through the common flow passage moves away from the first vent Intrusion of water into the first vent can be prevented.

  In the above configuration, when the second vent is formed in a region of the common flow path that does not face the first vent, entry of water into the first vent can be prevented. it can.

  According to the present invention, it is possible to provide an electrical junction box that has a smooth air flow, improves heat dissipation, and prevents water from entering.

The perspective view of the electrical junction box of Embodiment 1 Top view of electrical junction box Case perspective view Bottom view of electrical junction box Perspective view of holding member The exploded perspective view which disassembled the circuit board from the holding member Sectional drawing in the AA line of FIG. Enlarged sectional view of FIG. Sectional drawing in the BB line of FIG. Sectional drawing of the electrical junction box of Embodiment 2 Enlarged sectional view of FIG.

<Embodiment 1>
A first 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. 1 to 9. The electrical junction box 10 of this embodiment includes a case 11, a circuit board 20 accommodated in the case 11, and a holding member 30. The electrical connection box 10 of the present embodiment is disposed between, for example, a power source (not shown) and in-vehicle electrical components (not shown) such as a lamp and a horn, and energizes the in-vehicle electrical components, and Execute power interruption. In the following description, the upper side in FIG. 7 is the upper side, and the lower side in FIG. 7 is the lower side.

(Case 11)
As shown in FIGS. 1 to 3, the case 11 is made of synthetic resin and opens downward. The case 11 has a flat shape in which the dimension (thickness dimension) in the direction from the left front side to the right back side is set smaller than the dimension (width dimension) in the direction from the right front side to the left back side in FIG. I am doing. As shown in FIGS. 1 and 2, a plurality of (seven) fuse mounting portions 13 to which fuses (not shown) are mounted are provided on the upper wall of the case 11 so as to open upward. A substantially square-shaped recess 12 (a recess 12 protruding downward) is formed in a substantially central portion of the upper wall of the case 11 along with the fuse mounting portion 13. A cylindrical member 15 (details will be described later) having a side wall 16 integrated with the side wall of the recess 12 is provided at a position adjacent to the recess 12.

  Inside the fuse mounting portion 13, a fuse housing 37 that houses a terminal fitting 38 </ b> C protruding from the holding member 30 is provided. The end of the terminal fitting 38C protruding from the holding member 30 is bent in the direction of the board, and is inserted into the insertion hole 20C formed in the circuit board 20 to be connected to the conductive path formed in the circuit board 20 with, for example, soldering Etc. are connected.

  Of the side walls of the case 11, a pair of side walls 11A and 11A (FIG. 1) arranged substantially parallel to a substrate surface (a surface having a large area and a surface on which the electronic component 21 and the like are mounted) of the circuit board 20 described later. A locking hole 14 for locking the holding member 30 is formed at the lower end of the front side wall and the side wall at a position facing the side wall.

(Circuit board 20)
As shown in FIG. 5, the circuit board 20 is accommodated in the case 11 in a posture substantially perpendicular to the upper wall of the case 11 (in a so-called vertical arrangement). A conductive path (not shown) is formed on the surface of the circuit board 20 by a printed wiring technique, and an electronic component 21 such as a relay is mounted. The electronic component 21 is connected to the conductive path by a known method such as soldering. Connected by.

  As shown in FIG. 6, a cutout portion 22 into which a substrate holding portion 31 formed on the holding member 30 can be fitted is formed at the upper end portion of the circuit board 20. A screw insertion hole 23 through which a screw member (not shown) for attaching the substrate 20 to the holding member 30 is inserted is formed.

(Holding member 30)
The holding member 30 housed inside the case 11 is a synthetic resin member, and is arranged along the board surface of the circuit board 20 to hold the circuit board 20 as shown in FIGS. 5 and 6. It has a function. The holding member 30 is accommodated in the case 11 in a state of being arranged along the substrate surface of the circuit board 20, and as a result, as shown in FIG. 9, as shown in FIG. And the other space K2 on the opposite side across the holding member 30.

  On the surface of the holding member 30 on which the circuit board 20 is disposed (board side face 30A), the upper end of the holding member 30 is fitted into the notch 22 of the circuit board 20 as shown in FIG. A board holding portion 31 is provided, and a screw hole 32 into which a screw member can be screwed is provided corresponding to the screw insertion hole 23 of the circuit board 20. Further, a component housing portion 33 for housing the electronic component 21 mounted on the circuit board 20 is formed on the surface of the holding member 30 on the side where the circuit board 20 is disposed.

  At the lower end of the holding member 30, as shown in FIG. 5, a locking projection that is locked in a locking hole 14 formed in a pair of side walls 11A and 11A that are arranged substantially parallel to the substrate surface of the case 11. The part 34 is formed to protrude.

  A plurality of connector housings 35 and 36 that can be fitted to a mating connector (not shown) are formed at the lower end of the holding member 30 so as to open downward. The portion of the holding member 30 that is arranged on the back side shown in FIG. 5 is set such that the position of the lower end portion is higher (upward) than the other portions. A connector housing 35 (first connector housing 35) that can be fitted to the connector is formed to open downward, and can be fitted to a mating connector (not shown) in a portion arranged on the front side shown in FIG. A plurality (five) of connector housings 36 (second connector housings 36) are formed to open downward. Also, among the opening edges of the first connector housing 35, the opening edge on the side where the circuit board 20 is disposed is provided with a board receiving portion 39 for receiving the end of the circuit board 20, as shown in FIG. Is formed to protrude.

As shown in FIG. 6, terminal fittings 38 </ b> B are arranged inside the plurality of second connector housings 36 so as to penetrate the inner wall of the second connector housing 36 in the vertical direction. The upper end portion of the terminal fitting 38B is bent to the circuit board 20 side (the right side in FIG. 5) and is inserted into the insertion hole 20B formed in the circuit board 20 to form a conductive path (see FIG. For example, by soldering.
As shown in FIG. 7, terminal fittings 38 </ b> A are arranged inside the first connector housing 35 so as to penetrate the back wall of the first connector housing 35 in the vertical direction.

  A fuse housing accommodating portion 48 in which a terminal fitting 38 </ b> C protrudes is provided at a position corresponding to the lower portion of the fuse mounting portion 13 of the case 11 in the upper end portion of the holding member 30. The fuse housing accommodating portion 48 includes a lower wall portion 48A from which the terminal fitting 38C protrudes upward, and a pair of wall portions 46 and 47 that are cut upward from the lower wall portion 48A. Of the terminal fittings 38C attached to the lower wall portion 48A of the fuse housing accommodating portion 48, the terminal fitting 38C protruding outward from the holding member 30 is formed in the circuit board 20 by being bent toward the board. The conductive path is inserted into the insertion hole 20C and connected to the conductive path formed on the circuit board 20, for example, by soldering.

  In the holding member 30, the terminal fittings 38A and 38B arranged in the connector housings 35 and 36 are respectively molded. A terminal fitting 38 </ b> C disposed in the fuse housing 37 of the case 11 is also molded in the holding member 30. Thereby, each terminal metal fitting 38A, 38B, 38C penetrates the holding member 30 in a liquid-tight manner.

  A side wall portion (the right side wall portion 40 in FIG. 7, hereinafter referred to as “right side wall portion 40”) of the holding member 30 that extends from the fuse housing accommodating portion 48 is spaced from the inner wall surface of the case 11 in the case 11. Are arranged.

  Except for the lower end portion of the right side wall portion 40 of the holding member 30, a flange 45 is formed on the lower end portion of the holding member 30 so as to protrude outward in the circumferential direction of the second connector housing 36, as shown in FIG. Yes. When the lower end edge of the case 11 abuts on the flange 45 from above, the case 11 is restricted from moving downward relative to the holding member 30.

  Since the flange 45 is not formed at the lower end portion of the right side wall portion 40 of the holding member 30, the upper end portion of the right side wall portion 40 is between the right side wall portion 40 of the holding member 30 and the inner wall of the case 11. A space S1 is formed from the bottom to the bottom (see FIG. 7).

(Drainage structure and ventilation structure)
In the present embodiment, as shown in FIG. 7, an air outlet 12 </ b> A for discharging the air in the case 11 to the outside of the case 11 is provided on the side wall portion 16 of the recessed portion 12 provided on the upper wall of the case 11. Is provided. Although water flows into the dent 12, water is less likely to enter the case 11 than those provided with an air outlet opening in the upward direction.

  A cylindrical member 15 is provided adjacent to the recessed portion 12 on the inner side surface of the upper wall of the case 11, and the cylindrical member 15 is disposed in another space K <b> 2 in the case 11. The cylindrical member 15 has a rectangular cylindrical shape with an open lower end, and has a cylindrical side wall portion 16 extending downward. A part of the side wall portion 16 of the cylindrical member 15 is integrated with the side wall provided with the air outlet 12 </ b> A of the recessed portion 12. That is, the side wall portion 16 of the cylindrical member 15 is provided adjacent to the dent portion 12 so as to serve as a side wall provided with the air outlet 12A of the dent portion 12, thereby simplifying the structure. .

  The cylindrical member 15 functions as a drainage path for draining water flowing in from the air outlets 12A and 13A, and vents the air in the case 11 to the air outlets 12A and 13A and exhausts it outside the case 11. It is a member that also functions as an air passage (an example of the common flow passage 15). The air outlet 13A will be described later.

  The end surface of the lower end portion of the common flow passage 15 (the lower end surface of the side wall portion 16) is formed so that the fuse housing 37 side (the right side in FIG. 7) is inclined downward.

  On the lower side of the common flow passage 15, an inclined surface 41 </ b> A is arranged that extends from directly below the common flow passage 15 to the lower surface wall portion 48 </ b> A of the fuse housing accommodating portion 48 of the holding member 30. The inclined surface 41 </ b> A is a descending surface that is inclined downward as it is away from the lower end portion of the common flow passage 15, and is formed to the right end portion of the holding member 30 in FIG. 7. Water flowing from the common flow passage 15 flows through the inclined surface 41A and functions as the second drainage channel 41 together with the pair of wall portions 46 and 47 of the fuse housing accommodating portion 48. Of the pair of wall portions 46 and 47, the substrate-side wall portion 46 functions as a part of a partition wall that partitions the space in the case 11 into the substrate housing space K1 and the other space K2. In the following description, the space S2 partitioned by the inclined surface 41A and the pair of walls 46 and 47 in the case 11 is defined as a drainage space S2. The drainage space S2 is a space partitioned by an inclined surface 41A disposed in another space K2 in the case 11 and a pair of wall portions 46 and 47, and the common flow passage 15 is also disposed in the drainage space S2. Will be.

  At the upper end of the inclined surface 41A, a water blocking wall 42 protruding upward is provided up to a position above the lower end portion of the common flow passage 15, and the lower end of the common flow passage 15 is provided at the water blocking wall 42. A first ventilation port 43 that communicates the substrate housing space K1 and the other space K2 on the opposite side is provided at a position above the portion.

  The inclined surface 41A is continuous with the right side wall portion 40 of the holding member 30, and the right side wall portion 40 of the holding member 30 is arranged with a space between the case 11 as described above. The water that has flowed to the lower end portion of the holding member 30 flows down the space S <b> 1 formed by the right side wall portion 40 of the holding member 30 and the inner wall of the case 11, and is drained out of the case 11 from the lower end portion of the holding member 30. (See arrow Y in FIG. 7).

  As described above, in the present embodiment, the air outlet 12 </ b> A is provided on the side wall of the recessed portion 12, but the fuse housing 37 among the cylindrical side wall portions 16 of the common flow path 15 that also functions as a ventilation path. The side wall 16 on the side is also provided with an air outlet 13A. Specifically, in the side wall portion 16 of the common flow passage 15, the upper end of the side wall portion 16 on the fuse housing 37 side is at a position facing the air outlet 12 </ b> A (first air outlet 12 </ b> A) of the recess 12. An air outlet 13A (second air outlet 13A) for discharging the air in the case 11 to the outside of the case 11 is formed.

  A slit-like vent 18 is provided at the lower end of the side wall 16 on the fuse housing 37 side in the side wall 16 of the common flow passage 15. The vent 18 is the second vent 18 that communicates with the air outlets 12 </ b> A and 13 </ b> A and the first vent 43. The second vent 18, the first vent 43, the first air outlet 12A, and the second air outlet 13A are formed at positions that do not line up in a straight line as shown in FIG.

  As shown in FIG. 4, the lower end of the holding member 30 is located on the left side of the second connector housing 36 at the left end and the left side of the second connector housing 36 at the right end in FIG. An air inflow port 44 for introducing air into the case 11 is formed. In the present embodiment, the air introduced from the air inlet 44 is introduced into the substrate housing space K1.

(Operation and effect of this embodiment)
In the present embodiment, when current flows through the electronic component 21 mounted on the circuit board 20 and heat is generated, the air around the electronic component 21 is warmed. Here, the flow of air in the present embodiment will be described with reference to FIG. After the air heated in the substrate housing space K1 moves from the substrate housing space K1 to the other space K2 through the first vent 43 formed in the holding member 30, as indicated by the arrow X in FIG. The air is exhausted from the two air outlets 12A and 13A (the first air outlet 12A and the second air outlet 13A) through the common air passage 15 from the second vent 18 formed in the common air passage 15. . Here, the second vent 18 is formed above the first vent 43, and the air outlets 12A and 13A are formed on the upper wall of the case 11 above the second vent 18, The air in the substrate housing space K1 is smoothly guided upward and discharged out of the case 11. As a result, according to this embodiment, heat dissipation can be improved.

  In particular, in the present embodiment, the air inlet 44 for introducing air from the outside of the case 11 into the case 11 is formed at the lower end portion of the holding member 30, so that air circulation in the case 11 is smooth and heat dissipation. Can be improved with certainty. Furthermore, in this embodiment, since the two air outlets 12A and 13A are provided, the air in the case 11 is efficiently discharged out of the case 11.

  By the way, when the air outlets 12A and 13A are formed on the upper wall of the case 11 as in the electrical junction box 10 of the present embodiment, each air outlet 12A, There is concern about the intrusion of water from 13A.

  In the present embodiment, the first air outlet 12 </ b> A is formed on the side wall of the recess 12 formed on the upper wall of the case 11, and the second air outlet 13 </ b> A is formed on the side wall 16 of the common flow passage 15. Therefore, water is less likely to flow in than the air outlet opening in the upward direction.

  Still, water may flow into the case 11 from the air outlets 12A and 13A, but in this embodiment, the water that flows from the air outlets 12A and 13A is indicated by the arrow Y in FIGS. As shown in Fig. 5, after flowing into the common flow passage 15 arranged in the drainage space S2 in the case 11 and flowing through the inclined surface 41A (second drainage channel 41), the right side wall portion 40 of the holding member 30 and the case 11 The space S <b> 1 formed by the inner wall of the holding member 30 flows down and is drained out of the case 11 from the lower end portion of the holding member 30. That is, according to the present embodiment, even if water flows in from each of the air outlets 12A and 13A, the water that has flowed in is connected to the common flow passage 15 provided in the drainage space S2 (the space included in the other space K2) and the first flow passage. Since the water is drained out of the case 11 after flowing through the second drainage channel 41, water does not enter the circuit board 20.

Here, for example, even if the wall surface of the cover 11 is inclined with the first air vent 43 down because the entire electrical junction box 10 is inclined, the common flow passage 15 is introduced after flowing in from the air outlets 12A and 13A. The water that has entered the second vent 18 formed in the second vent 18 is not aligned with the first vent 43, the first air outlet 12A, and the second air outlet 13A. Therefore, it is difficult to move toward the first vent 43. As a result, according to the present embodiment, water can be prevented from entering the board housing space K1 (circuit board 20 side).
Therefore, according to the present embodiment, it is possible to provide the electrical junction box 10 in which the air flow is smooth to improve heat dissipation and to prevent water from entering.

  In addition, according to the present embodiment, the inclined surface 41A is inclined downward as it moves away from the lower end of the common flow passage 15, so that the water flowing in from the air outlets 12A and 13A flows through the common flow passage 15. After that, the water flows out of the case 11 through the inclined surface 41 inclined downward, so that the water is quickly drained without accumulating in the case 11.

  Further, according to the present embodiment, the water blocking wall 42 that is formed at the upper end of the inclined surface 41 to a position above the lower end portion of the common flow passage 15 and prevents water from entering the substrate housing space K1. Even if water is scattered from the lower end portion of the common flow passage 15 due to the inclination of the electrical junction box 10 or the like, the water blocking wall 42 can prevent water from entering the substrate housing space.

  Moreover, according to this embodiment, since the 1st ventilation port 43 is provided in the position above the lower end part of the common flow path 15 of the water stop wall 42, permeation of water to the board | substrate accommodation space K1 is carried out. In addition to preventing, the first vent 43 can be disposed in the vicinity of the common flow passage 15, so that the air vented from the first vent 43 can be passed through the second vent 18 or the common flow passage 15. The air is quickly exhausted from the air outlets 12A and 13A through the common flow passage 15 from the opening at the lower end. As a result, it is possible to prevent water from entering and further improve the heat dissipation.

  Further, according to the present embodiment, the end surface of the lower end portion of the common flow passage 15 is formed so that the fuse housing 37 side (the right side in FIG. 7) is inclined downward. That is, the end surface of the lower end portion of the common flow passage 15 is formed so as to be inclined downward as it is away from the first vent 43, so that the water flowing through the common flow passage 15 moves away from the first vent 43. Be guided.

  Moreover, according to this embodiment, since the 2nd ventilation hole 18 is formed in the area | region which does not face the 1st ventilation hole 43 among the common flow paths 15, the water to the 1st ventilation hole 43 is provided. Intrusion can be prevented.

<Embodiment 2>
Next, a second embodiment of the present invention will be described with reference to FIGS.
The electrical junction box 50 of the present embodiment is different from that of the first embodiment in that the air outlet 52 is provided only in the recessed portion 12 and the position of the second vent 55. Other configurations are generally the same as those of the first embodiment. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  In the present embodiment, as shown in FIGS. 10 and 11, a slit-like second vent 55 is provided at the lower end of the side wall 54 on the water blocking wall 42 side of the side wall 54 of the common flow passage 53. It has been. Also in the present embodiment, as in the first embodiment, the second vent 55 is formed at a position that is not aligned with the first vent 43 and the air outlet 52, as shown in FIG. .

  In the present embodiment, when current flows through the electronic component 21 mounted on the circuit board 20 and heat is generated, the air around the electronic component 21 is warmed. Here, the flow of air in the present embodiment will be described with reference to FIG. After the air heated in the substrate housing space K1 moves to the other space K2 through the first vent 43 formed in the holding member 51 as shown by an arrow P in FIG. The air is discharged from the air outlet 52 through the common flow passage 53 from the second vent 55 formed in 53. Here, since the second vent 55 is formed above the first vent 43 and the air outlet 52 is formed on the upper wall of the case 11 above the second vent 55, the substrate housing space The air of K1 is smoothly guided upward and discharged out of the case 11. As a result, according to this embodiment, heat dissipation can be improved.

  In particular, according to the present embodiment, since the second ventilation hole 55 is formed in the vicinity of the first ventilation hole 43, the discharge of air to the outside of the case 11 is smoother.

Also in the present embodiment, the air outlet 52 is formed on the side wall of the recessed portion 12 formed on the upper wall of the case 11, so that it is difficult for water to flow in. In particular, in the present embodiment, since only one air outlet 52 is provided, the possibility of water flowing into the case 11 is low.
Still, water may flow into the case 11 from the air outlet 52, but the water that flows in from the air outlet 52 is drained in the case 11 as indicated by the arrow Q in FIGS. After flowing into the common flow passage 53 arranged in S2 and flowing through the inclined surface 41A (second drainage channel 41), it flows down the space S1 formed by the right side wall portion 56 of the holding member 51 and the inner wall of the case 11. Then, the water is drained out of the case 11 from the lower end of the holding member 51. That is, according to the present embodiment, even if water flows in from the air outlet 52, the flow-in water flows into the common flow passage 53 and the second drainage provided in the drainage space S2 (the space included in the other space K2). Since the water is drained outside the case 11 after flowing through the path 41, it is difficult for water to enter the circuit board 20.

<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) In the above embodiment, the air inlet is formed at the lower end of the holding member. However, the air inlet may not be formed.
(2) In the above embodiment, one second vent is formed, but two or more second vents may be formed.
(3) In the above-described embodiment, the air outlet is formed on the side wall of the recess. However, the air outlet may be configured to open in the directly upward direction.
(4) In the above-described embodiment, the configuration in which the structure serving as the side wall of the recess and the side wall of the common flow path is provided, but the recess and the common flow path may be provided separately.
(5) In the above-described embodiment, the case upper wall is provided with the recess and the rectangular common flow passage. However, the common flow passage may be provided in the holding member. The common flow passage may have a cylindrical shape.
(6) In the above-described embodiment, the common flow passage and the second drainage channel are provided. However, the second drainage channel may not be provided, and the drainage may be performed only from the common flow passage.
(7) In the above embodiment, the second drainage channel having an inclined surface is shown, but a flat surface may be provided.
(8) In the above embodiment, the water stop wall is provided. However, the water stop wall may not be provided.
(9) In the above embodiment, the first vent is formed in the water blocking wall, but the first vent may be formed in a member other than the water blocking wall.
(10) In the above-described embodiment, the end surface of the lower end portion of the common flow path is formed so as to be inclined downward as the distance from the first vent hole is increased. May be formed to have the same height.

DESCRIPTION OF SYMBOLS 10,50 ... Electric junction box 11 ... Case 12 ... Recessed part 12A, 52 ... 1st air outflow port (air outflow port)
13A ... Second air outlet (air outlet)
15, 53 ... cylindrical member (common flow passage)
16, 54 ... Side wall portion of common flow path 18, 55 ... Second vent 20 ... Circuit board 21 ... Electronic component 30, 51 ... Holding member 30A ... Side surface of board (surface on which circuit board of holding member is arranged)
30B ... Opposite side surface (surface opposite to the surface on which the circuit board of the holding member is disposed)
40, 56 ... right side wall portion of holding member 41 ... second drainage channel 41A ... inclined surface 42 ... water blocking wall 43 ... first vent 44 ... air inflow port 46 ... wall portion (substrate side)
47 ... Wall (opposite side of substrate)
K1 ... Substrate accommodation space K2 ... Other space S1 ... Space between right side wall and case inner wall S2 ... Drainage space X, P ... Arrows indicating air flow Y, Q ... Arrows indicating water flow

Claims (9)

A case having an air outlet on the upper wall through which the internal air can flow out to the outside;
A circuit board housed in the case;
The circuit board is disposed along the board surface of the circuit board to hold the circuit board, and is housed in the case so that the space in the case is housed in the board housing space and the board housing space. A holding member for partitioning with other spaces,
The holding member is provided with a first ventilation hole that communicates the substrate housing space and the other space in the case.
There is provided a common flow passage that is arranged in the other space in the case and serves as a ventilation passage that vents the air in the case to the air outlet and a drainage passage that drains water flowing in from the air outlet. And
In the common flow passage, there is a second ventilation port that communicates with the first ventilation port at a position that is above the first ventilation port and is not aligned with the first ventilation port and the air flow outlet. An electrical junction box formed as described above. The electrical connection box according to claim 1, wherein an air inflow port for introducing air from outside the case into the case is formed at a lower end portion of the holding member. The upper wall of the case is formed with a recess protruding downward.
The electrical connection box according to claim 1, wherein the air outlet is formed on a side wall of the recess. The common flow passage has a cylindrical side wall portion extending downward, and the side wall portion serves as a side wall of the recess portion and is provided adjacent to the recess portion. 3. The electrical junction box according to 3. The common flow passage has a cylindrical shape extending downward and its lower end is open,
The holding member is formed with a partition wall that partitions the substrate housing space and the other space,
A second drainage having an inclined surface that is disposed on a lower side of the lower end of the common flow passage and is inclined downward as the distance from the lower end of the common flow passage is reduced on the other space side surface of the partition wall. The electrical junction box according to any one of claims 1 to 4, wherein a path is formed. The upper end of the inclined surface is formed up to a position above the lower end of the common flow passage, and a water blocking wall is formed to prevent water from entering the substrate housing space. The electrical junction box according to claim 5. The electrical connection box according to claim 6, wherein the first ventilation port is provided at a position above the lower end portion of the common flow path of the water blocking wall. The electrical junction box according to claim 7, wherein an end surface of a lower end portion of the common flow passage is formed so as to be inclined downward as the distance from the first ventilation port increases. 9. The electrical connection box according to claim 7, wherein the second vent is formed in a region of the common flow passage that does not face the first vent. 9.

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