Electrical junction box
The electrical junction box design with inner and outer ribs balances thermal expansion to prevent warping, ensuring structural integrity and compactness.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- SUMITOMO WIRING SYSTEMS LTD
- Filing Date
- 2022-06-01
- Publication Date
- 2026-07-22
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
The increase in the number of electronic components in vehicles leads to larger electrical connection boxes, which are susceptible to warpage due to heat generation, causing thermal expansion differences.
An electrical junction box design featuring inner and outer ribs on opposing walls, with the outer rib protruding from the second wall, canceling out thermal expansion differences to suppress warping, and incorporating inclined ends and constant dimensions to enhance cooling and structural integrity.
The design effectively suppresses warping by balancing thermal expansion, maintains structural integrity, and allows for a more compact electrical junction box.
Smart Images
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Abstract
Description
Technical Field
[0001] The present disclosure relates to an electrical connection box including a substrate.
Background Art
[0002] Conventionally, an electrical connection box for housing electronic components such as fuses and relays has been mounted on a vehicle.
[0003] The electrical connection box includes a housing. For example, the housing includes a first case having one side open for housing the electronic components, and a second case covering the open side of the first case (see Patent Document 1).
Prior Art Documents
Patent Documents
[0004]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0005] Due to the diversification of functions in vehicles, as the number of electronic components to be housed increases, the electrical connection box has also become larger. However, with the increase in the number of electronic components and the enlargement of the electrical connection box, it has become more susceptible to the influence of heat generation of the electronic components during energization. That is, there has been a problem that warpage occurs at the end in the longitudinal direction in the electrical connection box due to the difference in the amount of thermal expansion (contraction) caused by the heat generation of the electronic components.
[0006] However, the electrical connection box of Patent Document 1 does not consider such problems and cannot cope with them.
[0007] The present invention has been made in view of such circumstances, and an object thereof is to provide an electrical connection box capable of suppressing warpage caused by heat generation of electronic components.
Means for Solving the Problems
[0008] An electrical junction box according to the embodiment of the present disclosure is an electrical junction box having a first wall in contact with an object to be mounted and a second wall on which an inner rib protrudes from the surface opposite to the first wall, wherein an outer rib protrudes from the opposite surface of the second wall opposite to the surface opposite to the opposing surface. [Effects of the Invention]
[0009] According to this disclosure, it is possible to provide an electrical connection box that can suppress warping caused by heat generation in electronic components. [Brief explanation of the drawing]
[0010] [Figure 1] This is a perspective view of an electrical junction box according to an embodiment. [Figure 2] These are a plan view and a side view of an electrical junction box according to an embodiment. [Figure 3] This is an exploded view of an electrical junction box according to an embodiment. [Figure 4] This is a partial perspective view showing a second outer rib provided at one end of the ceiling wall in an electrical junction box according to an embodiment. [Figure 5] Figure 4 is a longitudinal cross-section taken along the line V-V. [Figure 6] This is a schematic partial cross-sectional view showing one end of a ceiling wall provided with a second outer rib in an electrical junction box according to the embodiment. [Figure 7] This figure shows the results of a simulation of the warping of an electrical junction box caused by differences in thermal expansion. [Modes for carrying out the invention]
[0011] [Description of Embodiments of the Invention] First, embodiments of this disclosure will be listed and described. Furthermore, at least some of the embodiments described below may be combined in any way.
[0012] (1) An electrical junction box according to the embodiment of the present disclosure is an electrical junction box having a first wall in contact with an object to be mounted and a second wall on which an inner rib is provided protruding from the surface opposite to the first wall, wherein an outer rib is provided protruding from the opposite surface of the second wall opposite to the surface opposite to the opposing surface.
[0013] In this embodiment, an inner rib is provided on the opposing surface of the second wall, and an outer rib is provided on the opposite surface opposite to the opposing surface. Therefore, the difference in shrinkage between the second wall and the inner rib, caused by the difference in the amount of heat generated during operation, is canceled out by the difference in shrinkage between the second wall and the outer rib, thereby suppressing warping of the second wall.
[0014] (2) In the electrical junction box according to the embodiment of the present disclosure, the inner rib and the outer rib are in the shape of a plate, and the thickness of the second wall is greater than the thickness of the inner rib and the outer rib.
[0015] In this embodiment, since the thickness of the second wall is greater than the thickness of the inner rib and the outer rib, heat generated during operation tends to accumulate more easily in the second wall than in the inner rib and the outer rib. This difference in the amount of accumulated heat causes a difference in shrinkage that leads to warping. However, the difference in shrinkage that occurs between the second wall and the inner rib is canceled out by the difference in shrinkage that occurs between the second wall and the outer rib, thereby suppressing warping of the second wall.
[0016] (3) In the electrical junction box according to the embodiment of the present disclosure, the end of the second wall is inclined in the longitudinal direction so that it approaches the first wall as it approaches the tip, and there are multiple outer ribs, and the dimensions of the outer ribs in the opposing direction of the first wall and the second wall are longer as they approach the tip in the longitudinal direction.
[0017] In this embodiment, the end of the second wall is inclined so as to approach the first wall as it gets closer to the tip, and the dimension of the outer rib in the facing direction of the first wall and the second wall becomes longer as it gets closer to the tip in the longitudinal direction. Therefore, by making the shrinkage difference generated between the second wall and the inner rib and the shrinkage difference generated between the second wall and the outer rib equal to each other, they cancel each other out, and the occurrence of warping of the second wall is suppressed.
[0018] (4) In the electrical connection box according to the embodiment of the present disclosure, the outer rib is provided at the end of the second wall in the longitudinal direction.
[0019] In this embodiment, the outer rib is provided at the end of the second wall where a large amount of warping occurs. Therefore, the occurrence of warping of the second wall can be suppressed more efficiently.
[0020] (5) In the electrical connection box according to the embodiment of the present disclosure, side walls extending in the facing direction are provided around the edge of the second wall, and the dimension from the first wall to the tip of the side wall in the facing direction is constant.
[0021] In this embodiment, the dimension from the first wall to the tip of the side wall in the facing direction is constant. Therefore, it is possible to prevent the strength from locally decreasing at the end of the second wall due to the inclination of the end of the second wall so as to approach the first wall.
[0022] [Details of Embodiments of the Present Invention] The electrical connection box according to the embodiment of the present disclosure will be described below with reference to the drawings. Note that the present invention is not limited to these examples, and is shown by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.
[0023] Figure 1 is a perspective view of the electrical junction box 100 according to the embodiment, Figure 2 is a plan view and a side view of the electrical junction box 100 according to the embodiment, and Figure 3 is an exploded view of the electrical junction box 100 according to the embodiment. Figure 2A is a plan view of the electrical junction box 100, and Figure 2B is a side view of the electrical junction box 100. The electrical junction box 100 is mounted on the outside of the object to be installed, for example, the battery pack 200 of an EV (Electric Vehicle) (see Figure 2). For ease of explanation, Figure 2B shows the electrical junction box 100 mounted on the battery pack 200.
[0024] The electrical junction box 100 includes a housing 50 that houses, for example, a fuse, a circuit board, etc. The housing 50 is a flat housing, approximately rectangular in plan view, with one corner of one end in the longitudinal direction cut out in a stepped shape. The housing 50 is made of, for example, resin and consists of a lower case 30 that is attached to the mounting object and an upper case 20 that covers the lower case 30. For the sake of explanation, the upper case 20 side will be referred to as the top and the lower case 30 side as the bottom.
[0025] The lower case 30 has the shape of a box with one side open on the side facing the upper case 20. The lower case 30 has a bottom wall 31 (first wall) whose outer surface is in contact with the mounting object, and a side wall 33 that extends perpendicularly from the edge of the bottom wall 31 toward the upper case 20. Multiple ribs are formed on the inside of the lower case 30 (see Figure 3).
[0026] The bottom wall 31 of the lower case 30 has recesses 32b formed at both ends in the longitudinal direction and a recess 32a formed in the middle. The recesses 32a and 32b are formed at positions corresponding to the fastening portion 23 of the upper case 20, which will be described later.
[0027] More specifically, recesses 32b are formed at both corners of both ends of the lower case 30. Each recess 32b is roughly rectangular in plan view, and the side wall 33 is bent at approximately a right angle at each recess 32b, with the recessed corners being chamfered (see Figure 3).
[0028] Furthermore, a recess 32a is formed in the middle of the long side of the lower case 30. The recess 32a is approximately rectangular in plan view. The side wall 33 is recessed inward of the lower case 30 at the recess 32a, and the recessed corners are chamfered (see Figure 3).
[0029] The upper case 20 has the shape of a box with one side facing the lower case 30 open. The upper case 20 is slightly larger than the lower case 30 in both its length and width (perpendicular to the length), and covers the lower case 30.
[0030] Furthermore, the upper case 20 has a ceiling wall 21 (second wall) facing the bottom wall 31 of the lower case 30, and side walls 22 that are provided around the edge of the ceiling wall 21 and extend in the vertical direction. The upper case 20 is provided with fastening parts 23 at both ends and in the middle of its length for attaching the upper case 20 to the mounting object.
[0031] More specifically, the fastening portions 23 are provided at both corners of one end in the longitudinal direction, and at both corners and between both corners of the other end. Furthermore, in the upper case 20, three fastening portions 23 are arranged in parallel in the width direction in the middle of the longitudinal direction. Each fastening portion 23 protrudes from the inner surface 214 (opposing surface) of the ceiling wall 21 facing the bottom wall 31 (see Figure 5), and all fastening portions 23 except for one fastening portion 23 located approximately in the center of the ceiling wall 21 are provided near the side wall 22 (see Figure 2A).
[0032] Multiple inner ribs 25 are provided protruding from the inner surface 214 of the ceiling wall 21 (see Figure 5). The multiple inner ribs 25 are arranged in parallel in the longitudinal direction, and each inner rib 25 is plate-shaped and extends in the width direction. Furthermore, the thickness of each inner rib 25 is thinner than the thickness of the ceiling wall 21.
[0033] Each fastening portion 23 has a bottomed cylindrical shape, with the ceiling wall 21 side open. In addition, a fixing through hole 231 is formed at the bottom of each fastening portion 23, which is used when attaching the housing 50 to the mounting object (see Figure 5). The housing 50 (electrical connection box 100) can be attached to the mounting object by inserting a screw from the mounting object into the fixing through hole 231 of the fastening portion 23 and screwing it into a nut (not shown) provided inside the fastening portion 23.
[0034] As described above, the fastening portion 23 of the upper case 20 is positioned inside the recesses 32a and 32b of the lower case 30.
[0035] Multiple connection points 212 for connecting to other devices are provided at various locations on the outer surface 211 (opposite side) of the ceiling wall 21, opposite to the inner surface 214. In addition, multiple mounting seats 213 for relays 400 are provided approximately in the center of the outer surface 211 of the ceiling wall 21, and multiple relays 400 are mounted there. For convenience, the relays 400 are not shown in Figure 3.
[0036] Furthermore, multiple outer ribs 24 are provided protruding from the outer surface 211 of the ceiling wall 21. The outer ribs 24 include a first outer rib 24a to prevent warping caused by gravity, and a second outer rib 24b to prevent warping caused by differences in thermal expansion, as will be described later.
[0037] The first outer rib 24a has a triangular plate shape and is mainly provided on the edge of the ceiling wall 21. That is, the vertical dimension of each first outer rib 24a decreases as it moves from the center of the ceiling wall 21 closer to the edge. As described above, the first outer rib 24a suppresses warping of the ceiling wall 21 caused by the weight of the relay 400 (see Figures 1 and 2) mounted in the center.
[0038] The second outer rib 24b is plate-shaped and is provided at the end of the ceiling wall 21 in the longitudinal direction. For convenience, this embodiment will be described using the example where the second outer rib 24b is provided at only one end of the ceiling wall 21, but it is not limited to this and may be provided at both ends. The thickness of each second outer rib 24b is thinner than the thickness of the ceiling wall 21.
[0039] Figure 4 is a partial perspective view showing a second outer rib 24b provided on one end 21a of the ceiling wall 21 in the electrical junction box 100 according to the embodiment, and Figure 5 is a longitudinal cross-sectional view taken along the line V-V in Figure 4.
[0040] As described above, the second outer rib 24b is provided on one end 21a of the ceiling wall 21. The second outer rib 24b is provided in the vertical direction at a position corresponding to the inner rib 25, or near the said corresponding position. The vertical dimension (hereinafter also referred to as height) of the second outer rib 24b is larger the closer it is to the edge of the ceiling wall 21.
[0041] As shown in Figure 5, the ceiling wall 21 is inclined downward at one end 21a in the longitudinal direction. That is, the end 21a of the ceiling wall 21 on which the second outer rib 24b is provided is inclined so that it approaches the bottom wall 31 of the lower case 30 as it gets closer to the edge, while the other parts excluding the end 21a maintain a constant distance from the bottom wall 31. Furthermore, the dimension L from the bottom wall 31 to the top (hereinafter referred to as the top dimension L) is approximately the same for all second outer ribs 24b.
[0042] As described above, while the upper end dimension L of multiple second outer ribs 24b is the same, one end 21a of the ceiling wall 21 is inclined downwards as it approaches the edge. Therefore, the vertical dimension of the second outer rib 24b itself increases as it approaches the edge of the ceiling wall 21.
[0043] Furthermore, as described above, although one end 21a of the ceiling wall 21 is inclined downwards as it approaches the edge, the dimension from the bottom wall 31 of the lower case 30 to the tip of the side wall 22 of the upper case 20, that is, to the upper end of the side wall 22, is constant in the vertical direction.
[0044] That is, as shown in Figure 4, the edge of one end 21a of the ceiling wall 21 in the longitudinal direction, i.e., the dimension H1 from the bottom wall 31 to the upper end of the side wall 22 on the short side of the ceiling wall 21, is the same as the dimension H2 from the bottom wall 31 to the upper end of the side wall 22 on the long side of the ceiling wall 21.
[0045] As the electrical junction box 100 according to this embodiment has such a configuration, the second outer rib 24b can suppress the occurrence of warping in the ceiling wall 21 due to the difference in thermal expansion, as described above. This will be explained in detail below.
[0046] Figure 6 is a schematic partial cross-sectional view showing one end 21a of the ceiling wall 21 provided with the second outer rib 24b in the electrical junction box 100 according to the embodiment, and Figure 7 is a diagram showing the results of a simulation of the warping of the electrical junction box 100 caused by the difference in thermal expansion. For convenience, only the outline of the electrical junction box is shown in Figure 7. Figure 7A shows the case where one end 21a of the ceiling wall 21 is not inclined and the second outer rib 24b is not provided, and Figure 7B shows the case where one end 21a of the ceiling wall 21 is inclined and the second outer rib 24b is provided, i.e., the case of the electrical junction box 100 according to this embodiment.
[0047] If one end 21a of the ceiling wall 21 is not inclined and only the inner rib 25 and the first outer rib 24a are provided (see the dashed line in Figure 6), when the electrical junction box 100 is operating, heat is generated in the relay 400, etc., causing the end of the ceiling wall 21 to bend upwards where the inner rib 25 is not provided (see Figure 7A).
[0048] This is because the ceiling wall 21 is thicker than the inner rib 25 and is in direct contact with a heat source (e.g., relay 400), so it holds a large amount of heat, while the inner rib 25 is thin and easily cooled by air, resulting in a difference in contraction (thermal expansion) between the ceiling wall 21 and the inner rib 25.
[0049] In contrast, in the electrical junction box 100 according to this embodiment, as described above, a second outer rib 24b is formed on the outer surface 211 of the ceiling wall 21. Therefore, the difference in shrinkage that occurs between the ceiling wall 21 and the inner rib 25 is canceled out by the difference in shrinkage that occurs between the ceiling wall 21 and the second outer rib 24b, thereby suppressing warping of the ceiling wall 21.
[0050] As shown in Figure 7B, in the electrical junction box 100 according to this embodiment, the formation of a second outer rib 24b on the outer surface 211 of the ceiling wall 21 suppresses the occurrence of warping in the ceiling wall 21.
[0051] Furthermore, in the electrical junction box 100 according to this embodiment, as described above, the end portion 21a of the ceiling wall 21 on which the second outer rib 24b is provided is inclined downwards as it approaches the edge. Therefore, the height of the second outer rib 24b increases as it approaches the edge of the ceiling wall 21 (see the dashed line portion in Figure 6), which enhances the air cooling effect. Thus, warping of the ceiling wall 21 can be suppressed more effectively.
[0052] Thus, in the electrical junction box 100 according to this embodiment, the height of the second outer rib 24b is secured by inclining one end 21a of the ceiling wall 21 downwards, thereby suppressing the height of the second outer rib 24b and making the electrical junction box 100 more compact.
[0053] Furthermore, in the electrical junction box 100 according to this embodiment, as described above, the second outer rib 24b is provided at the end of the ceiling wall 21 where warping occurs. By providing the second outer rib 24b intensively at the locations where warping occurs in the ceiling wall 21, the electrical junction box 100 according to this embodiment can be made more compact while more efficiently suppressing the occurrence of warping in the ceiling wall 21.
[0054] In the electrical junction box 100 according to this embodiment, as described above, one end 21a of the ceiling wall 21 is inclined downwards as it approaches the edge, whereas the dimension from the bottom wall 31 to the tip of the side wall 22 of the upper case 20 in the vertical direction is constant. Therefore, it is possible to prevent a localized decrease in the strength of the upper case 20 at one end 21a of the ceiling wall 21.
[0055] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the invention is indicated by the claims, not in the sense described above, and all modifications within the sense and scope equivalent to the claims are intended.
[0056] The matters described in each embodiment can be combined with each other. Furthermore, the independent and dependent claims described in the claims can be combined with each other in any combination, regardless of the form of reference. In addition, the claims use a form in which claims referencing two or more other claims (multi-claim form), but are not limited to this. A form in which multi-claims referencing at least one multi-claim (multi-multi-claim) may also be used. [Explanation of symbols]
[0057] 20 Upper Case 21 Ceiling and Wall (Second Wall) 21a One end 22 Side wall 23 Fastening section 24 Outer Ribs 24a First outer rib 24b Second outer rib 25 Inner Rib 30 Lower Cases 31 Bottom wall (First wall) 32a Recess 32b Recess 33 Side wall 50 cabinets 100 Electrical junction box 200 Battery Pack 211 Outer surface (opposite side) 212 Connection part 213 Mounting Seat 214 Inner surface (opposing surface) 231 Fixed through hole 400 relays
Claims
1. An electrical junction box having a first wall that contacts the object to be mounted, and a second wall on which an inner rib is provided protruding from the surface opposite to the first wall, On the opposite side of the second wall, opposite to the opposing surface, an outer rib is provided at a position corresponding to the inner rib, or near said corresponding position. In the longitudinal direction, the end of the second wall is inclined such that it approaches the first wall as it gets closer to the tip. The aforementioned outer ribs are numerous, An electrical junction box in which the dimensions of the outer ribs in the opposing directions of the first and second walls are longer as they approach the end in the longitudinal direction.
2. The electrical junction box according to claim 1, wherein the outer rib is provided at the end of the second wall in the longitudinal direction.
3. The electrical junction box according to claim 1, wherein a side wall extending in the opposing direction is provided around the edge of the second wall, and the dimension from the first wall to the tip of the side wall is constant in the opposing direction.