Electrical junction box

Abstract

One embodiment provides an electrical connection box that can improve drainage and heat dissipation. [Solution] An electrical junction box according to one embodiment comprises an insulating case having a bottom plate portion having at least one drain hole formed therein, and a bus bar housed in the case, wherein the bus bar has a stepped portion that is convex in the thickness direction of the bottom plate portion toward the opposite side from the bottom plate portion, and the stepped portion overlaps with at least a part of the drain hole when viewed from the thickness direction, and a space communicating with at least a part of the drain hole is formed in the region partitioned by the bottom plate portion and the stepped portion.

Description

【Technical Field】 , , , 【0004】 , 【0006】 , , , , , , 【0005】 , , , , , , , , 【0001】 Embodiments of the present invention relate to an electrical connection box. 【Background Art】 【0002】 Electrical connection boxes that house busbars are known. In the electrical connection box disclosed in Patent Document 1, drain holes are formed in the lower case. In the electrical connection box disclosed in Patent Document 2, drain ports and heat dissipation ports are formed through the side wall of the case. 【Prior Art Documents】 【Patent Documents】 【0003】 【Patent Document 1】 Japanese Patent Application Laid-Open No. 08-251764 【Patent Document 2】 Japanese Patent Application Laid-Open No. 2010-114962 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0004】 By the way, when water intrusion occurs inside the electrical connection box, drainage may be difficult. Also, improvement in heat dissipation performance is required. 【0005】 One embodiment provides an electrical connection box capable of improving drainage and heat dissipation performance. 【Means for Solving the Problems】 H 【0006】 An electrical connection box according to one embodiment includes an insulating case having a bottom plate portion in which at least one drain hole is formed, and a busbar housed in the case. The busbar has a stepped portion that protrudes toward the side opposite to the bottom plate portion in the plate thickness direction of the bottom plate portion. The stepped portion overlaps at least a part of the drain hole when viewed from the plate thickness direction, and a space communicating with at least a part of the drain hole is formed in a region defined by the bottom plate portion and the stepped portion. 【Effects of the Invention】 【0007】 According to one embodiment, drainage and heat dissipation can be improved. [Brief explanation of the drawing] 【0008】 [Figure 1] A perspective view showing an electrical junction box of an embodiment. [Figure 2] A plan view showing the electrical junction box of the embodiment. [Figure 3] This is a view of the electrical junction box of the embodiment, seen from the opposite side to Figure 2. [Figure 4] A perspective view showing the inside of the electrical junction box of the embodiment. [Figure 5] Figure 4 is a perspective view showing a magnified view of the area around the stepped section of the busbar. [Figure 6] A cross-sectional view along the line VI-VI in Figure 5. [Figure 7] A cross-sectional view along the line VII-VII in Figure 5. [Modes for carrying out the invention] 【0009】 The embodiments will be described below with reference to the drawings. In the following description, expressions indicating relative or absolute arrangements such as "parallel," "orthogonal," "center," and "coaxial" will not only strictly mean such arrangements or states, but will also include arrangements or states that are relatively displaced by an angle or distance that allows for tolerances or the same function to be obtained. In the drawings used in the following description, the scale of each component may be changed as appropriate in order to make each component recognizable. 【0010】 <Electrical junction box> Figure 1 is a perspective view showing the electrical junction box 1 of the embodiment. Figure 2 is a plan view showing the electrical junction box 1 of the embodiment. Figure 3 is a view of the electrical junction box 1 of the embodiment from the opposite side to Figure 2. Figure 4 is a perspective view showing the interior of the electrical junction box 1 of the embodiment. Referring to Figures 1 to 4, the electrical junction box 1 comprises an insulating case 2 having a bottom plate portion 20 with at least one drainage hole 10, and a busbar 3 housed in the case 2. Note that components other than the busbar 3 inside the electrical junction box 1 are not shown in the figures. 【0011】 The electrical junction box 1 is installed in vehicles such as EVs (Electric Vehicles), HEVs (Hybrid Electric Vehicles), or PHEVs (Plug-in Hybrid Electric Vehicles). The electrical junction box 1 is positioned, for example, between a power source and an on-board electrical component, and controls the power supply and de-power supply to the on-board electrical component. 【0012】 In the following explanation, the X, Y, and Z orthogonal coordinate system will be used as needed. The Z direction corresponds to the thickness direction of the base plate 20. The XY direction corresponds to the in-plane direction of the base plate 20. The Y direction is perpendicular to the X and Z directions. In the following explanation, of the X, Y, and Z directions, the side indicated by the arrow in the diagram will be considered the positive (+) side, and the side opposite the arrow will be considered the negative (-) side. The Z direction coincides with the vertical direction. The +Z side corresponds to the upper side in the vertical direction. The -Z side corresponds to the lower side in the vertical direction. 【0013】 <Case> Case 2 is formed of an insulating material such as synthetic resin. Case 2 is formed in the shape of a bottomed box with an opening on the +Z side. The bottom plate portion 20 of Case 2 is formed in a rectangular shape with its longitudinal side in the X direction when viewed from the Z direction. The bottom plate portion 20 is formed in a plate shape parallel to the XY plane. Case 2 has a peripheral wall portion 21 extending from the outer edge of the bottom plate portion 20 towards the +Z side. In Case 2, the opening on the +Z side is covered with a cover 4 (see Figure 1). Note that the cover 4 and other components are not shown in Figures 2 to 4. 【0014】 In Case 2, when viewed from the Z direction, it includes a pair of partition wall portions 22 and 23 arranged outside in the X direction via the bus bar 3. The pair of partition wall portions 22 and 23 extend in the Y direction while bending along the outer shape of the bus bar 3 when viewed from the Z direction. A space S for accommodating the bus bar 3 is partitioned by the portion on the outer side in the Y direction in the peripheral wall portion 21 and the pair of partition wall portions 22 and 23. Among the pair of partition wall portions 22 and 23, the partition wall portion 22 on the -X side partitions the space S for accommodating the bus bar 3 and the -X side of this space S. The partition wall portion 23 on the +X side partitions the space S for accommodating the bus bar 3 and the +X side of this space S. 【0015】 <Bus bar> The bus bar 3 is, for example, made of metal. The bus bar 3 is formed, for example, by bending a single metal plate multiple times. The bus bar 3 is formed in a Y shape when viewed from the Z direction. The bus bar 3 has a stepped portion 30 that forms a convex shape (inverted U shape) toward the +Z side when viewed from the X direction. 【0016】 FIG. 5 is a perspective view showing an enlarged view of the periphery of the stepped portion 30 of the bus bar 3 in FIG. 4. FIG. 6 is a cross-sectional view taken along line VI-VI of FIG. 5. FIG. 7 is a cross-sectional view taken along line VII-VII of FIG. 5. Referring to FIGS. 4 to 7 together, the stepped portion 30 forms a convex shape (inverted U shape) toward the +Z side when viewed from the X direction. The stepped portion 30 overlaps at least a part of the drain hole 10 when viewed from the Z direction. 【0017】 The stepped portion 30 has a plate-like first surface portion 31 parallel to the XY plane, a second surface portion 32 extending from the -Y end portion of the first surface portion 31 to the -Z side, and a third surface portion 33 extending from the +Y end portion of the first surface portion 31 to the -Z side when viewed from the X direction. 【0018】 The first surface portion 31 extends with a uniform width from the -Y end side to the +Y side when viewed from the Z direction, and then extends so as to widen toward both outer sides in the X direction. The X-direction width of the second surface portion 32 is smaller than the X-direction width of the third surface portion 33. 【0019】 The busbar 3 further includes a first extension portion 35 extending along the bottom plate portion 20 from one end of the stepped portion 30, and a second extension portion 36 extending along the bottom plate portion 20 from the other end of the stepped portion 30. The first extension portion 35 extends from the -Z end of the second surface portion 32 of the stepped portion 30 toward the -Y side. When viewed from the Z direction, the first extension portion 35 bends from the +Y end toward the -Y and -X sides, then extends linearly toward the -Y side, and then extends toward the +X side. The -Z side of the first extension portion 35 is in contact with the +Z side of the bottom plate portion 20. 【0020】 The second extension portion 36 extends from the -Z end of the third surface portion 33 in the stepped portion 30 toward the +Y side. When viewed from the Z direction, the second extension portion 36 branches from the -Y end toward the X direction and extends toward the +Y side from both sides in the X direction. The -Z side surface of the second extension portion 36 is in contact with the +Z side surface of the bottom plate portion 20. 【0021】 The stepped portion 30 is positioned towards the center of case 2 in the XY direction. When viewed from the Z direction, the stepped portion 30 is positioned on the +X side (closer to the center than the +X end) relative to the center in the X direction, and on the +Y side (closer to the center than the +Y end) relative to the center in the Y direction. 【0022】 <Drain hole> Multiple drainage holes 10 are formed. The multiple drainage holes 10 include a first hole 11 formed in a position that avoids the stepped portion 30 when viewed from the Z direction, and a second hole 12 formed in a position that overlaps with the stepped portion 30. The first hole 11 is formed in a rectangular shape when viewed from the Z direction. Note that the plan view shape of the first hole 11 is not limited to the above and can be changed according to the design specifications. 【0023】 The first hole 11 is formed in a position that does not overlap with the stepped portion 30 when viewed from the Z direction. The first hole 11 is formed in region A of the bottom plate portion 20 adjacent to the stepped portion 30 when viewed from the Z direction. This region A is partitioned when viewed from the Z direction by the portion of the partition wall portion 22 on the -X side that is on the Y-direction central side and the -X-side outer edge of the stepped portion 30. 【0024】 Multiple first holes 11 are formed. In the illustrated example, two of the multiple first holes 11 are formed in region A adjacent to the stepped portion 30 in the bottom plate portion 20. The two first holes 11 are spaced apart from each other in the X and Y directions within region A. Note that the number and arrangement of the first holes 11 are not limited to the above and can be changed according to the design specifications. 【0025】 The second hole 12 is formed as a slit that points toward the first hole 11 when viewed from the Z direction. Multiple second holes 12 are formed. When viewed from the Z direction, the multiple second holes 12 are formed as elongated slits in the Y direction and are arranged at approximately equal intervals in the X direction. In the illustrated example, each of the multiple second holes 12 is formed at a position that overlaps with the stepped portion 30. 【0026】 At least two of the multiple second holes 12 are oriented toward the first hole 11. In the illustrated example, the second hole 12 closest to the -X end is oriented toward the first hole 11 on the -X side, and the second and third holes from the -X end are oriented toward the second hole 12 on the +X side. Viewed from the Y direction, the second hole 12 closest to the -X end is positioned to overlap with the first hole 11 on the -X side, and the second and third holes from the -X end are positioned to overlap with the second hole 12 on the +X side. Note that the number and arrangement of the second holes 12 oriented toward the first hole 11 are not limited to the above and can be changed according to the design specifications. 【0027】 The second hole 12 is located directly below the stepped portion 30 in the vertical direction. In the illustrated example, each of the multiple second holes 12 is located directly below the stepped portion 30 in the vertical direction. 【0028】 <Space connected to the drain hole> A space 40 is formed in the region demarcated by the bottom plate portion 20 and the stepped portion 30, and communicates with at least a part of the drain hole 10. The space 40 is formed in the region demarcated by the first surface portion 31, the second surface portion 32 and the third surface portion 33 of the stepped portion 30 and the portion of the bottom plate portion 20 facing the first surface portion 31, as viewed from the X direction. The space 40 communicates with each of the two first holes 11 located in region A adjacent to the stepped portion 30 of the bottom plate portion 20 and with each of the plurality of second holes 12 located directly below the stepped portion 30. 【0029】 Space 40 connects one end and the other end of the stepped portion 30. When viewed from the X direction, space 40 connects the second surface portion 32 and the third surface portion 33 of the stepped portion 30 in the X direction. 【0030】 The minimum dimension H of the space 40 in the Z direction is greater than the plate thickness t of the bottom plate portion 20 (H>t). The minimum dimension H of the space 40 in the Z direction corresponds to the distance between the -Z side of the first surface portion 31 in the stepped portion 30 and the +Z side of the portion of the bottom plate portion 20 facing the first surface portion 31, as viewed from the X direction. The plate thickness t of the bottom plate portion 20 corresponds to the maximum thickness in the Z direction of the portion of the bottom plate portion 20 facing the first surface portion 31, as viewed from the X direction. 【0031】 <Effects and Effects> As described above, the electrical junction box 1 of this embodiment comprises an insulating case 2 having a bottom plate portion 20 in which at least one drain hole 10 is formed, and a bus bar 3 housed in the case 2. The bus bar 3 has a stepped portion 30 that is convex in the direction opposite to the bottom plate portion 20 in the thickness direction of the bottom plate portion 20. When viewed from the thickness direction, the stepped portion 30 overlaps with at least a part of the drain hole 10. A space 40 that communicates with at least a part of the drain hole 10 is formed in the area partitioned by the bottom plate portion 20 and the stepped portion 30. With this configuration, if water ingress occurs inside the electrical junction box 1, it can be drained through the drain hole 10 in the bottom plate portion 20. In addition, the space 40 that communicates with at least a part of the drain hole 10 expands the space and path for drainage, thus improving drainage performance. Furthermore, the formation of a space 40 in the area partitioned by the bottom plate 20 and the stepped portion 30 makes it easier to draw in air from the outside, causing convection inside the electrical junction box 1 and improving heat dissipation. In addition, the convex shape of the stepped portion 30 of the busbar 3, which faces away from the bottom plate 20, increases the surface area of ​​the busbar 3, thereby reducing the amount of heat transferred per unit area and lowering the saturation temperature due to heat conduction within the busbar 3. Also, because the stepped portion 30 of the busbar 3 is floating relative to the bottom plate 20, the cooling effect due to heat radiation in that area is also improved. Therefore, drainage and heat dissipation can be improved. 【0032】 In this embodiment, multiple drainage holes 10 are formed. The multiple drainage holes 10 include a first hole 11 formed in a position that avoids the stepped portion 30 when viewed from the plate thickness direction, and a second hole 12 formed in a position that overlaps with the stepped portion 30. With this configuration, if water ingress occurs inside the electrical connection box 1, it can be drained through the first hole 11 and the second hole 12 of the bottom plate portion 20. Therefore, drainage performance can be further improved. 【0033】 In this embodiment, the first hole 11 is formed in region A adjacent to the stepped portion 30 in the bottom plate portion 20 when viewed from the plate thickness direction. With this configuration, the first hole 11 and the second hole 12 are closer together compared to the case where the first hole 11 is formed outside region A adjacent to the stepped portion 30 in the bottom plate portion 20. This arrangement allows for improved drainage through the first hole 11 and the second hole 12 in the bottom plate portion 20. 【0034】 In this embodiment, the second hole 12 is formed in a slit shape that faces toward the first hole 11 when viewed from the plate thickness direction. With this configuration, the slit-shaped second hole 12 facing toward the first hole 11 ensures a water flow path and enables efficient drainage. 【0035】 In this embodiment, multiple second holes 12 are formed. At least two of the multiple second holes 12 are directed toward the first hole 11. With this configuration, drainage can be further improved through the multiple second holes 12. In addition, by having at least two of the multiple second holes 12 directed toward the first hole 11, a water flow path is secured, and more efficient drainage can be achieved. 【0036】 In this embodiment, the second hole 12 is positioned directly below the stepped portion 30 in the vertical direction. With this configuration, if water ingress occurs inside the electrical junction box 1, it can be efficiently drained through the second hole 12 due to the action of gravity. In addition, the space 40 directly below the stepped portion 30 expands the space and path for drainage, thus improving drainage performance. 【0037】 In this embodiment, the busbar 3 further includes a first extended portion 35 extending from one end of the stepped portion 30 along the bottom plate portion 20, and a second extended portion 36 extending from the other end of the stepped portion 30 along the bottom plate portion 20. With this configuration, the surface area of ​​the busbar 3 is further increased, which further reduces the amount of heat transferred per unit area and further lowers the saturation temperature due to heat conduction within the busbar 3. 【0038】 In this embodiment, the stepped portion 30 is positioned towards the center of the case 2 in the in-plane direction of the bottom plate portion 20. With this configuration, convection is more likely to occur inside the electrical connection box 1, and heat dissipation is further improved, compared to the case where the stepped portion 30 is positioned towards the outer end of the case 2 in the in-plane direction of the bottom plate portion 20. 【0039】 In this embodiment, the space 40 connects one end and the other end of the stepped portion 30. With this configuration, convection is more likely to occur inside the electrical connection box 1 compared to the case where the space 40 is partitioned between one end and the other end of the stepped portion 30, and heat dissipation is further improved. 【0040】 In this embodiment, the minimum dimension H of the space 40 in the thickness direction is greater than the thickness t of the bottom plate 20 (H>t). With this configuration, compared to the case where the minimum dimension H of the space 40 in the thickness direction is less than or equal to the thickness t of the bottom plate 20 (H≦t), the space and path for drainage are expanded, thus improving drainage performance. 【0041】 <Variation> In the embodiments described above, an example was given in which multiple drainage holes are formed, but the invention is not limited to this example. For example, only one drainage hole may be formed. The number of drainage holes can be changed according to the design specifications. 【0042】 In the embodiments described above, the example of a plurality of drainage holes including a first hole formed at a position avoiding the stepped portion when viewed from the plate thickness direction, and a second hole formed at a position overlapping the stepped portion, was explained, but the invention is not limited to this example. For example, the plurality of drainage holes do not have to include a first hole formed at a position avoiding the stepped portion when viewed from the plate thickness direction. For example, at least a portion of the second hole (drainage hole) may be formed at a position overlapping the stepped portion when viewed from the plate thickness direction. The formation manner of the first and second holes can be changed according to the design specifications. 【0043】 In the embodiments described above, the first hole was explained as being formed in a region adjacent to the stepped portion in the bottom plate when viewed from the plate thickness direction, but the invention is not limited to this example. For example, the first hole may be formed outside the region adjacent to the stepped portion in the bottom plate when viewed from the plate thickness direction. The location of the first hole can be changed according to the design specifications. 【0044】 In the embodiments described above, the second hole was described as being formed in a slit shape that points toward the first hole when viewed from the plate thickness direction, but the invention is not limited to this example. For example, the second hole may be formed in a circular or rectangular shape when viewed from the plate thickness direction. The shape of the second hole can be changed according to the design specifications. 【0045】 In the embodiments described above, examples were given in which multiple second holes are formed, but the invention is not limited to this example. For example, only one second hole may be formed. The number of second holes can be changed according to the design specifications. 【0046】 In the embodiments described above, an example was given in which at least two of the plurality of second holes are directed toward the first hole, but the invention is not limited to this example. For example, only one of the plurality of second holes may be directed toward the first hole. The manner in which the plurality of second holes are directed toward the first hole can be changed according to the design specifications. 【0047】 In the embodiments described above, the second hole was described as being positioned directly below the stepped portion in the vertical direction, but the invention is not limited to this example. For example, the second hole does not have to be positioned directly below the stepped portion in the vertical direction. For example, the second hole may be positioned so as to overlap the stepped portion when viewed from a direction intersecting the vertical direction. The arrangement of the second hole can be changed according to the design specifications. 【0048】 In the above-described embodiment, the busbar was described as having a first extension portion extending along the bottom plate portion from one end of the stepped portion, and a second extension portion extending along the bottom plate portion from the other end of the stepped portion, but it is not limited to this example. For example, the busbar does not have to have at least one of the first extension portion and the second extension portion. For example, the busbar only needs to have a stepped portion that is convex in the direction opposite to the bottom plate portion in the thickness direction of the bottom plate portion. The configuration of the busbar can be changed according to the design specifications. 【0049】 In the embodiments described above, the stepped portion was explained as being located towards the center of the case in the in-plane direction of the bottom plate, but the invention is not limited to this example. For example, the stepped portion may be located towards the outer end of the case in the in-plane direction of the bottom plate. The arrangement of the stepped portion can be changed according to the design specifications. 【0050】 In the embodiments described above, the space was explained as being connected between one end and the other end of the stepped portion, but the invention is not limited to this example. For example, the space may be partitioned between one end and the other end of the stepped portion. The manner in which the space is opened can be changed according to the design specifications. 【0051】 In the embodiments described above, the minimum dimension of the space in the thickness direction was explained using an example where the minimum dimension was greater than the thickness of the bottom plate, but this is not the only example. For example, the minimum dimension of the space in the thickness direction may be less than or equal to the thickness of the bottom plate. The size of the space can be changed according to the design specifications. 【0052】 Although embodiments and modifications have been described above, embodiments and modifications are not limited to these examples. Embodiments and modifications can be added, omitted, substituted, and otherwise changed without departing from the spirit of the present invention, and can also be combined with each other. [Explanation of symbols] 【0053】 1. Electrical junction box 2 cases 3 bus bars 10 Drain hole 11 Hole 1 12 Hole 2 20. Base plate section 30-step section 35. The first extension is in the department. 36. The second extension is in the department. 40 spaces A field Minimum size method of H space t Plate thickness of bottom plate

Claims

[Claim 1] An insulating case having a bottom plate portion in which at least one drainage hole is formed, The case comprises a busbar housed in the aforementioned case, The bus bar has a stepped portion that is convex in the thickness direction of the bottom plate portion toward the opposite side from the bottom plate portion, The stepped portion overlaps with at least a part of the drain hole when viewed from the plate thickness direction, A space is formed in the region partitioned by the bottom plate portion and the stepped portion that communicates with at least a portion of the drain hole. Electrical junction box. [Claim 2] Multiple drainage holes are formed, The multiple drainage holes, when viewed from the plate thickness direction, A first hole formed at a position avoiding the aforementioned stepped portion, A second hole formed at a position overlapping with the stepped portion, The electrical junction box according to claim 1. [Claim 3] The first hole is formed in the area adjacent to the stepped portion of the bottom plate when viewed from the plate thickness direction. The electrical junction box according to claim 2. [Claim 4] The second hole is formed in the shape of a slit that is directed toward the first hole when viewed from the plate thickness direction. The electrical junction box according to claim 3. [Claim 5] Multiple second holes are formed, At least two of the plurality of second holes are directed toward the first hole. The electrical junction box according to claim 4. [Claim 6] The second hole is located directly below the stepped portion in the vertical direction. An electrical junction box according to any one of claims 2 to 5. [Claim 7] The aforementioned busbar is A first extending portion extends from one end of the stepped portion along the bottom plate portion, It further includes a second extending portion that extends from the other end of the stepped portion along the bottom plate portion, An electrical junction box according to any one of claims 1 to 5. [Claim 8] The stepped portion is positioned towards the center of the case in the in-plane direction of the bottom plate portion. An electrical junction box according to any one of claims 1 to 5. [Claim 9] The aforementioned space connects one end and the other end of the stepped portion. An electrical junction box according to any one of claims 1 to 5. [Claim 10] The minimum dimension of the space in the thickness direction is greater than the thickness of the bottom plate. An electrical junction box according to any one of claims 1 to 5.

Images