JP5531765B2 - Electrical junction box - Google Patents

Description

  The present invention relates to an electrical junction box.

  Conventionally, as an example of an electrical connection box that is mounted on a vehicle and executes energization or disconnection of an in-vehicle electrical component such as a lamp or an audio device, one described in Patent Document 1 is known. In this electrical junction box, a circuit casing that houses a circuit board is divided into a back cover body that covers the back side of the circuit board and a front cover body that covers the front side of the circuit board. And the joint surface of both cover bodies is closed by carrying out the vibration welding of both cover bodies. Moreover, in this thing, the drain hole is formed in the surrounding wall of a back surface side cover body, and it has the structure which drains the water droplet in a circuit casing outside.

JP 2009-291043 A

  In the vibration welding, the workpiece is vibrated in the horizontal direction while applying pressure, thereby melting the resin with the frictional heat at that time and welding the joint surfaces. When the peripheral wall is notched as described above, the friction becomes non-uniform, so that joining of the mating surfaces becomes incomplete and water may enter from the mating surfaces. In addition to waterproofness, the circuit casing needs to be breathable, and it is necessary to achieve both waterproofness and breathability.

  The present invention has been created in view of the above circumstances, and an object thereof is to provide an electrical junction box that is excellent in air permeability and waterproofness.

The present invention includes a circuit board on which an electronic component is mounted, a base plate and an annular peripheral wall formed on the entire periphery of the base plate, and a synthetic resin container for housing the circuit board, and an opening of the container A synthetic resin closing body for closing the surface, and a connector having a bus bar formed integrally with the closing body and electrically connected to a conductive path of the circuit board. Is formed so that the mating surface of the container and the closing body is sealed over the entire circumference, and the circuit board is directed vertically with respect to a predetermined mounting location. And the lower shape of the container is a V-shape inclined from both sides in the width direction toward the center, and the V-shaped top portion of the outer surface of the bottom plate in response to lower low surface than other surfaces Is formed, the formed corresponding to the top of the V-shape on the lower surface portion, having characterized in that the formation of the vent holes through the low surface portion. The term “lower than the other surface” as used herein means the level of the step in the thickness direction of the electrical junction box, and the surface that recedes from the other surface is called the lower surface. On the other hand, the protruding surface is called the high surface.

According to this configuration, the peripheral wall is formed on the entire periphery of the bottom plate. Therefore, when vibration welding is performed, friction does not become non-uniform, and the mating surfaces of the container and the closing body can be reliably joined. Therefore, waterproofness is enhanced. Further, according to this configuration, the vent hole penetrating the plate surface is formed in the bottom plate of the container. Moreover, since the periphery of the vent hole is a lower surface part lower than the other surfaces, the mating wall does not block the vent hole when the electric junction box is attached. Moreover, since the lower shape of the container is V-shaped, it is possible to take out water droplets in the electrical connection box through the vent hole, and the vent hole can also function as a drain hole. .

As an embodiment of the present invention, the following configuration is preferable.
A water blocking wall that prevents water droplets traveling on the outer surface of the bottom plate from flowing into the vent hole side is formed on the low surface portion around the vent hole. If it does in this way, it can control that the water drop which propagates a baseplate flows into a vent hole.

-Form the water blocking wall twice. If it does in this way, even if a water droplet gets over the 1st-stage still water wall and is transmitted to the vent hole side, it will be distributed to the side of the vent hole by the 2nd-stage water stop wall. Therefore, it becomes more difficult for water droplets to flow into the vent hole.

· Said to form a partition wall for partitioning a formation region of the vent hole and the housing area of the circuit board in the housing body. In this way, even when water enters the electrical junction box through the vents, such as when the vehicle is flooded, it becomes possible to dam the water for a short time at the partition wall, and the circuit board is filled with water. It becomes possible to earn time to reach.

  ADVANTAGE OF THE INVENTION According to this invention, the electrical junction box excellent in air permeability and waterproofness can be provided.

The exploded perspective view of the electric junction box applied to one embodiment of the present invention Perspective view of electrical junction box View of electrical junction box viewed from the front AA line sectional view in FIG. The figure which expanded the B section of FIG. View of electrical junction box viewed from the back side CC sectional view of FIG. DD sectional view in FIG. Perspective view of container

1. Overall Structure of Electrical Junction Box An embodiment in which the present invention is applied to an electrical junction box 10 for a vehicle will be described with reference to FIGS. 1 is an exploded perspective view of the electrical junction box, FIG. 2 is a perspective view of the electrical junction box, FIG. 3 is a diagram of the electrical junction box viewed from the front side, FIG. 4 is a cross-sectional view taken along line AA in FIG. These are the figures which expanded the B section of FIG.

  As shown in FIG. 1, the electrical junction box 10 includes a circuit board 20 and a circuit casing 30. The circuit board 20 is obtained by mounting an electronic component Z such as a semiconductor relay on a rectangular printed board formed with a conductive path (not shown) by a printed wiring technique. The circuit board 20 is provided with a moisture-proof insulating coating (a liquid resin is applied by spraying or the like to form a thin film) after mounting electronic components, and water droplets adhere to the circuit board 20 due to condensation. However, the electrical performance is not affected.

  The circuit casing 30 accommodates the circuit board 20 therein, and includes a housing 31 and a closing body 51. The container 31 is made of a synthetic resin (for example, a thermoplastic resin such as polybutylene terephthalate or polypropylene), and includes a plate-like bottom plate 32 and a peripheral wall 41 erected along the periphery of the bottom plate 32. As a whole, it has a box shape (tray type) with a shallow bottom. The bottom plate 32 of the housing 31 has a shape that is slightly larger than the circuit board 20. The bottom plate 32 protrudes downward from the center of the lower end, and has a pentagonal shape as a whole.

  The peripheral wall 41 is formed over the entire periphery of the bottom plate 32, and a flange 42 is provided at the end of the wall. The flange 42 projects outward and is formed over the entire circumference of the peripheral wall 41. Further, a protrusion 43 is integrally formed on the flange 42. The ridge 43 is continuously formed over the entire circumference of the peripheral wall 41 and has an annular shape. The peripheral wall 41 functions as a side wall that covers four sides of the outer periphery of the circuit board.

  The closing body 51 is made of a synthetic resin (for example, a thermoplastic resin such as polybutylene terephthalate or polypropylene), and has a pentagonal plate shape that can close the opening surface of the housing 31. The closing body 51 is slightly larger than the outer shape of the housing body 31, and when the closure body 51 is overlapped with the opening surface of the housing body 31, the tip of the protrusion 43 of the housing body 31 is slightly inside the periphery of the back surface of the closing body 51. It has a configuration that hits the position. In the closing body 51, two support bosses 59 formed with screw holes are provided on both sides in the width direction on the inner surface side facing the bottom plate 32 of the housing body 31. The board 20 can be screwed.

  Further, on the surface of the closing body 51, a pair of seat surface portions 53 and 54 are formed on the left and right sides in the width direction from the back side to the near side in FIG. 1, and on the upper surface of the closing body 51, A horizontally long connector block 100 is integrally formed over the entire width. This connector block 100 is provided with six hood portions 115 to 165 arranged in the width direction, and constitutes six connectors 110 to 160. The hood portions 115 to 165 of each of these six connectors 110 to 160 are each provided with a fitting port for fitting the mating connector on the front side in FIG. 1 (lower side when the electric connection box 10 is mounted on the vehicle). The mating connector is fitted by an assembling operation from the lower side.

  Moreover, the bus bar B is insert-molded in the connector block 100 so as to correspond to the hood portions 115 to 165. Each bus bar B is formed by bending a metal plate into an L shape, and has one end protruding into the corresponding hood portion 115 to 165 as shown in FIG. Further, the other end side of each bus bar B is drawn out to the circuit board 20 side and is configured to be inserted into the through hole SH of the circuit board 20.

  The closing body 51 is placed on the opening of the housing 31 while the circuit board 20 attached to the back surface is housed in the housing 31, and closes the housing 31. Further, the closing body 51 is vibration welded to a protrusion 43 formed on the peripheral wall 41 of the housing 31, and the mating surface F of the housing 31 and the closing body 51 has a sealed structure. And in this thing, since the protrusion part 43 used as a joining edge is formed without a cut | interruption over the perimeter of the container 31, the joint surface F of the container 31 and the closing body 51 is in a perimeter. It has a completely sealed structure. The tip of the ridge 43 is formed in a taper shape so that it can be easily melted during vibration welding.

2. Air Vent FIG. 6 is a view of the electrical junction box 10 as seen from the back side. As shown in FIG. 6, a guide slope 34 and a low surface portion 35 are formed on the outer surface side of the bottom plate 32 of the container 31. The guide slope 34 is intermittently formed along the outer peripheral edge 32 a of the bottom plate 32. The guide slope 34 is an invitation for setting the electrical junction box on an attachment (a mounting tool, not shown) of the vibration welding apparatus. Further, a gentle taper P is formed on the outer peripheral edge 32a of the bottom plate 32 on the entire circumference except for the formation position of a vent hole 37 described below.

  The low surface portion 35 is formed at the center of the lower portion of the outer surface of the bottom plate 32. As shown in FIGS. 4 and 5, the low surface portion 35 is one step lower than the general surface G of the bottom plate 32. In other words, in the thickness direction of the electrical junction box 10, the surface is set back from the general surface G to the right in FIG. As shown in FIG. 6, the low surface portion 35 has a V-shaped pentagon formed at the bottom, and penetrates the bottom plate 32 of the container 31 at the vertex of the V-shape. Thus, a ventilation hole 37 is formed. By forming the air holes 37, the electrical junction box 10 can be ventilated. Therefore, it is difficult for condensation to occur, and generation of water droplets in the electrical junction box 10 can be prevented.

  Further, by forming the air holes 37 on the lower surface portion 35, when the electrical connection box 10 is attached to a box (corresponding to an attachment location, not shown) installed in the vehicle engine room, FIG. As shown, a gap δ corresponding to a step is secured between the tip 37 a of the air hole 37 and the inner wall 200 on the box side, and the air hole 37 is not blocked by the inner wall 200.

  Further, a water blocking wall 39 having the same height as the general surface G is formed on the lower surface portion 35 so as to surround the vent hole 37. More specifically, as shown in FIG. 6, the water blocking wall 39 has an arc shape and extends downward while surrounding the upper side of the vent hole 37. The water blocking wall 39 extends downward through the left and right sides of the vent hole 37, and the lower end reaches the lower edge of the bottom plate 32. By providing such a water blocking wall 39, it is possible to distribute the water droplets W transmitted on the outer surface of the container 31 to both sides of the vent hole 37 and prevent the water droplets from being transmitted to the vent hole 37 side. Further, in this embodiment, the water blocking walls 39 are formed in double, and even if the water droplets W get over the outer water blocking walls 39a, the water droplets W are separated from both sides of the vent hole 37 by the inner water blocking walls 39b. Can be distributed to.

  In addition, the vent hole 37 functions as a discharge hole, and when a water droplet enters the inside of the container, it is discharged. That is, the lower shape of the container 31 has a gentle V-shape inclined from both sides in the width direction toward the center, and water droplets inside the container are transmitted toward the top of the V-shape. Since the air hole 37 is formed at the top of the V shape, these water droplets can be discharged to the outside of the container 31 through the air hole 37.

  Further, as shown in FIG. 5, a concave water droplet pool 57 is formed on the back surface of the closing body 51 and in front of the air hole 37, and water droplets inside the container are likely to collect on the front surface of the air hole 37. It has a structure. By doing so, the inner water droplets can easily flow into the vent hole 37. Further, as shown in FIGS. 5 and 7, the vent hole 37 is formed narrower as the hole diameter goes outward (outlet side). By doing in this way, it becomes difficult for water droplets to enter from the outside.

  Further, the air hole 37 has a function as an inspection hole. If it demonstrates concretely, in order to confirm the airtightness of the circuit casing 30, the electrical connection box 10 performs a pressurization test | inspection. In the pressure test, the pressure hole of the test head (not shown) is pressed against the test hole of the electrical connection box 10 and the pressure at that time is inspected. The airtight state can be confirmed.

  Since the pressure inspection is performed in a state where the inspection head is abutted against the hole edge of the inspection hole, in order to perform the inspection reliably, the inspection head ( (Not shown) is preferably performed in close contact with the hole edge of the inspection hole. In this respect, in the embodiment, the water blocking walls 39 a and 39 b are formed at a certain distance from the air hole 37, and a flat contact surface U for abutting the inspection head around the air hole 37 is secured. . Therefore, the inspection head can be brought into close contact with the contact surface U, and air leakage hardly occurs during the pressure inspection.

3. Partition Wall Structure As shown in FIGS. 8 and 9, a partition wall 45 is formed at a position near the lower portion of the bottom plate 32 of the container 31. The partition wall 45 extends horizontally in the width direction of the container 31. Both ends of the partition wall 45 reach the peripheral wall 41 and are continuous with the inner surfaces of the peripheral walls 41a and 41b forming the V shape. The partition wall 45 functions to vertically partition the accommodation area H1 of the circuit board 20 and the formation area H2 of the vent hole 37. In FIG. 8, the ventilation hole 37 is not shown in the formation region H2, but this is because the cut line of the cross section does not pass through the ventilation hole 37, and the ventilation hole 37 has a height range of the formation region H2. Is formed inside.

  A backflow prevention wall 46 is formed at the center of the partition wall 45. The backflow prevention wall 46 is located just above the formation position of the vent hole 37 and has an arc shape. The backflow prevention wall 46 protrudes toward the closing body 51 as compared with the partition wall 45. Further, as shown in FIG. 5, a concave concave portion 56 is formed on the back surface side of the closing body 51 so as to be positioned in front of the reverse flow prevention wall 46, and the reverse flow prevention wall 46 has a concave portion 56 at the wall tip. Facing inside. By doing in this way, the path | route which goes to the inner side of the circuit casing 30 through the ventilation hole 37 becomes a labyrinth structure, and the water droplet which entered from the ventilation hole 37 cannot enter into the inside (upper) of the circuit casing 30, and It has become.

  The partition wall 45 and the backflow prevention wall 46 have a taper that descends downward toward the front end of the wall, and water droplets in the circuit casing 30 are transmitted downward along the taper. As a result, the air is discharged from the air hole 37.

4). Description of assembly procedure The structure of each member 20, 31, 51 constituting the electrical junction box 10 is as described above. Next, the assembly procedure of the electrical junction box 10 will be described. In order to perform assembly, it is first necessary to fix the circuit board 20 to the closing body 51. In order to do this, as shown in FIG. 1, the surface 21 on which the electronic component Z is mounted is directed to the closing body 51 side, and each insertion hole 25 on the substrate is positioned on a support boss 59 provided in the closing body 51. In this state, the circuit board 20 may be screwed to the support boss 59, whereby the circuit board 20 is fixed to the closing body 51 in a state of being lifted by the height of the support boss 59. . In this state, the bus bars B1 to B6 of the connectors 110 to 160 formed integrally with the closing body 51 are inserted into the through holes SH on the circuit board 20.

  Thereafter, the inserted bus bars B1 to B6 are soldered to the through holes SH of the circuit board 20, and the bus bars B1 to B6 are electrically connected to conductive paths (not shown) of the circuit board 20.

  After that, the closing body 51 is put on the container 31 from above. Thereby, the circuit board 20 mounted on the back surface of the closing body 51 is accommodated in the housing 31, and the opening of the housing 31 is closed by the closing body 51.

  After that, the electrical connection box 10 is set horizontally with respect to the attachment (mounting device, not shown), and then the outer peripheral portion is pressurized by a tool horn of a vibration welding device (not shown), and further, vibration is generated in the horizontal direction. Added. Thereby, the front-end | tip part of the protrusion 43 of the container 31 melts | dissolves by the frictional heat by vibration, and is joined to the back surface of the closing body 51. FIG. Thereby, the mating surface F of the container 31 and the closing body 51 is joined over the entire circumference, and the assembly of the electrical junction box 10 is completed.

  The electrical connection box 10 is vertically oriented with the circuit board 20 housed inside in a vertical direction (FIG. 3) with respect to a box (which corresponds to an attachment location, not shown) installed in the vehicle engine room. , In the direction of FIG. At the same time as or before and after the electrical connection box 10 is attached to the box, the mating connectors connected to the power supply, electrical components, etc. are attached to the hoods 115 to 165 of the connectors 110 to 160 from below. Then, the electric power supplied from the power source can be distributed and supplied to each electrical component through the electric connection box 10, and switching of the electric power supply can be controlled by the electric connection box 10.

Then, the effect | action and effect of this embodiment are demonstrated.
According to the electrical junction box 10, the peripheral wall 41 and the protrusion 43 are formed on the entire circumference of the bottom plate 32 of the container 31. Therefore, when vibration welding is performed, friction does not become non-uniform, and the mating surface F of the container 31 and the closing body 51 can be reliably joined over the entire circumference. In addition, since the connector block 100 is integrally formed with the closing body 51, there is almost no gap for water drops to enter the circuit casing 30, and high waterproof performance can be exhibited. Therefore, waterproofness is enhanced.

  Further, in the electrical junction box 10, a vent hole 37 penetrating the plate surface is formed in the bottom plate 32 of the container 31. In addition, since the periphery of the air hole 37 is the lower surface portion 35 lower than the general surface G, the air hole 37 is not blocked by the mating wall 200 when the electric junction box 10 is attached. Therefore, the air permeability can be reliably ensured.

  Further, since the air hole 37 also serves as a drain hole, even if condensation occurs, water droplets generated by the condensation can be drained to the outside, and the water droplets do not stay in the circuit casing 30.

  In the present embodiment, a partition wall 45 is formed in the lower part of the housing 31 so that the housing area H1 of the circuit board 20 and the formation area H2 of the air holes 37 are partitioned vertically. Therefore, even when water enters the electrical junction box 10 through the air holes 37, such as when the vehicle is flooded, the partition wall 45 can dam the water for a short time, and the circuit board 20 has water. It is possible to earn time until it reaches.

  In this embodiment, a backflow prevention wall 46 is provided immediately above the vent hole 37. Therefore, even when the high-pressure washing water flows back into the circuit casing through the vent hole 37 when the vehicle is washed at high pressure, the washing water can be blocked by the backflow prevention wall 46.

<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, an example in which the vent hole 37 is formed in the lower part of the bottom plate 32 of the container 31 is illustrated. However, the bottom plate 32 does not necessarily need to be the lower part, and is positioned closer to the center in the vertical direction. It is also possible to form it.

  (2) In the above embodiment, an example in which the six connectors 110 to 160 are aggregated as the connector block 100 is illustrated, but it is needless to say that the connectors 110 to 160 are provided separately from the circuit casing 30. Is possible.

DESCRIPTION OF SYMBOLS 10 ... Electrical junction box 20 ... Circuit board 30 ... Circuit casing 31 ... Housing 32 ... Bottom wall 35 ... Low surface part 37 ... Vent hole 39 ... Water stop wall 41 ... Perimeter wall 42 ... Flange 43 ... Projection part 51 ... Closure body 100 ... Connector block 110-160 ... Connector B ... Bus bar F ... Mating surface G ... General surface (corresponding to "other surface" of the present invention)

Claims (4)

A circuit board on which electronic components are mounted;
A synthetic resin container having a bottom plate and an annular peripheral wall formed on the entire circumference of the bottom plate, and containing the circuit board;
A synthetic resin closing body for closing the opening of the container;
A connector having a bus bar formed integrally with the closing body and electrically connected to a conductive path of the circuit board, and vibration welding the peripheral wall of the housing to the closing body An electrical connection box having a structure in which a mating surface of the container and the closing body is hermetically sealed over the entire circumference, and the circuit board is vertically mounted with respect to a predetermined mounting location in a vertical direction. ,
The lower shape of the container is a V-shape that is inclined from both sides in the width direction toward the center, and a lower surface portion that is lower than the other surfaces corresponds to the V-shaped top portion of the outer surface of the bottom plate. Formed,
An electrical junction box , wherein a vent hole penetrating the low surface portion is formed on the low surface portion formed corresponding to the top of the V shape .   The electrical junction box according to claim 1, wherein a water blocking wall that prevents water droplets traveling on the outer surface of the bottom plate from flowing into the vent hole side is formed on the lower surface portion around the vent hole. .   The electrical junction box according to claim 2, wherein the water blocking wall is doubled. The electrical junction box according to any one of claims 1 to 3, wherein a partition wall is formed in the housing body for partitioning the formation region of the vent hole and the housing region of the circuit board.

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