Electrical Junction Box
The electrical junction box design uses a partially high-thermal-conductivity second case member and a stacked heat dissipation member to efficiently dissipate heat, addressing cost concerns associated with high-thermal-conductivity materials and reducing manufacturing costs.
Patent Information
- Application Number
- JP2021020795
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2021-02-12
- Publication Date
- 2025-01-22
- Estimated Expiration
- 2041-02-12
AI Technical Summary
The use of synthetic resin materials with high thermal conductivity in electrical junction boxes increases manufacturing costs due to their expense.
The electrical junction box design incorporates a case with a first case member and a second case member, where the second case member has a first portion made of a material with higher thermal conductivity than the second portion, and includes a heat dissipation member stacked on the second case member to efficiently dissipate heat while reducing material costs.
This configuration allows for efficient heat dissipation while minimizing manufacturing costs by utilizing a partially high-thermal-conductivity material in the second case member, enhancing heat transfer efficiency and reducing overall production expenses.
Smart Images
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Abstract
Description
[Technical field]
[0001] The present disclosure relates to an electrical junction box. [Background technology]
[0002] For example, in an automobile, in order to supply power from a battery to multiple on-board devices, electric wires from the battery are first connected to an electrical connection box (also called a "junction box"), and then connected from the electrical connection box to each of the on-board devices (see, for example, Patent Document 1).
[0003] The electrical junction box described in Patent Document 1 is housed in a battery case and includes an equipment cover having an upper cover member and a lower cover member, a relay housed in the equipment cover, and a bus bar connected to a terminal of the relay. One end of the bus bar is connected to the terminal of the relay and the other end is connected to a connector terminal attached to the equipment cover, and this connector terminal is connected to another device such as a battery via a cable.
[0004] A relay generates heat by repeatedly opening and closing contacts. Therefore, in this type of electrical connection box, heat dissipation to the outside of the equipment cover is necessary. In the electrical connection box described in Patent Document 1, heat dissipation sheets are provided between an intermediate portion located between one end and the other end of the bus bar and the lower cover member, and between the lower cover member and the battery case, and the bus bar, one heat dissipation sheet, the lower cover member, and the other heat dissipation sheet are stacked vertically. Heat transferred from the terminal of the relay to the bus bar is transferred to the battery case via the two heat dissipation sheets and the lower cover member, and dissipated. [Prior art documents] [Patent documents]
[0005] [Patent Document 1] JP 2018-93713 A Summary of the Invention [Problem to be solved by the invention]
[0006] In the technology described in Patent Document 1, the lower cover member, which is a heat dissipation path, of the device cover is made of a synthetic resin material with a higher thermal conductivity than the upper cover member. However, since synthetic resin materials with high thermal conductivity are expensive, the lower cover member causes the manufacturing cost of the electrical junction box to rise.
[0007] An object of the present disclosure is to provide an electrical junction box that can reduce manufacturing costs. [Means for solving the problem]
[0008] The electrical connection box of the present disclosure Case and a relay attached to the case; a heat dissipation member connected to the relay in a heat-transferable manner, the case includes a first case member and a second case member connected to the first case member and forming an accommodation space between the first case member and a second case member; the heat dissipation member is disposed in the accommodation space by being stacked on the second case member, the second case member has a first portion that is laminated on the heat dissipation member and a second portion other than the first portion, The first portion is formed from a material having a higher thermal conductivity than the second portion. Effect of the Invention
[0009] According to the present disclosure, the manufacturing costs of the electrical junction box can be reduced. [Brief description of the drawings]
[0010] [Figure 1] FIG. 2 is a perspective view of an electrical junction box according to the embodiment; [Diagram 2] FIG. 2 is a plan view of the electrical junction box according to the embodiment. [Diagram 3]FIG. 2 is a front view showing the relays and bus bars of the electrical junction box. [Figure 4] 4 is a perspective view of a portion of a lower case member of the case, as viewed obliquely from above. FIG. [Diagram 5] 1 is a perspective view of a portion of an upper case member of the case, seen obliquely from above. [Figure 6] 1 is a perspective view of a portion of an upper case member of the case, seen obliquely from below. [Figure 7] 3 is a cross-sectional view taken along line AA in FIG. 2. [Figure 8] FIG. 3 is a cross-sectional view taken along line BB in FIG. [Figure 9] FIG. 2 is a perspective view showing components of the bus bar and heat dissipation structure. [Figure 10] FIG. 2 is an exploded perspective view showing components of the bus bar and the heat dissipation structure. [Figure 11] 3 is a cross-sectional view taken along line CC in FIG. 2. [Figure 12] FIG. 9 is an enlarged view of part D in FIG. [Figure 13] 8 is an enlarged view of an electric junction box according to a modified example, the view corresponding to a portion E in FIG. 7. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0011] [Overview of the embodiment of the present disclosure] The gist of an embodiment of the present disclosure includes at least the following.
[0012] (1) An electrical junction box according to an embodiment of the present disclosure includes: Case and a relay attached to the case; a heat dissipation member connected to the relay in a heat-transferable manner, the case includes a first case member and a second case member connected to the first case member and forming an accommodation space between the first case member and a second case member; the heat dissipation member is disposed in the accommodation space by being stacked on the second case member, the second case member has a first portion that is laminated on the heat dissipation member and a second portion other than the first portion, The first portion is formed from a material having a higher thermal conductivity than the second portion.
[0013] According to the above configuration, the second case member has a first portion and a second portion, and the first portion is made of a material having a higher thermal conductivity than the second portion. Therefore, heat generated in the relay is transferred to the first portion of the second case member via the heat dissipation member, and is conducted through the first portion with high efficiency. Therefore, the heat can be efficiently dissipated from the first portion to the outside. Furthermore, since the second case member is partially formed of a material having a high thermal conductivity, the second case member can be manufactured more inexpensively than when the entire second case member is formed of a material having a high thermal conductivity, and the manufacturing cost of the electrical connection box can be reduced.
[0014] (2) Preferably, the heat dissipation member includes a first heat dissipation member made of metal connected to the relay in a manner capable of transferring heat, and a second heat dissipation member made of synthetic resin arranged between the first heat dissipation member and the first portion and laminated on the first heat dissipation member and the first portion. With this configuration, heat generated in the relay is transferred to the first part of the second case member via the first heat dissipation member made of metal and the second heat dissipation member made of synthetic resin, conducts through the first part with high efficiency, and is dissipated to the outside. The first heat dissipation member may be a member dedicated to heat dissipation, or may be a bus bar connected to the relay.
[0015] (3) Preferably, the first portion is recessed more than the second portion on a surface of the second case member opposite to the heat dissipation member, A third heat dissipation member is laminated on a surface of the first portion opposite to the heat dissipation member side. According to this configuration, the third heat dissipation member is laminated in the recessed portion of the surface of the second case member opposite to the heat dissipation member side, so that the third heat dissipation member can be laminated without being misaligned with respect to the first portion. Furthermore, when the third heat dissipation member is adhered to the first portion, the adhesive surface can be positioned in the recessed portion, so that peeling of the third heat dissipation member from the first portion can be suppressed, for example, during transportation of the electrical junction box.
[0016] (4) Preferably, the first portion is restricted from moving relative to the second portion toward an opposite side to the heat dissipation member. With this configuration, the heat dissipation member can be sandwiched and compressed between the first case member and the first portion of the second case member, thereby bringing the heat dissipation member and the first portion into close contact with each other, allowing efficient heat transfer between the two.
[0017] (5) Preferably, the first case member has a positioning portion that protrudes toward the heat dissipation member and is inserted into the heat dissipation member and the first portion. According to this configuration, the heat dissipation member and the first portion can be reliably positioned relative to the first case member.
[0018] [Details of the embodiment of the present disclosure] Hereinafter, the details of the embodiments of the present disclosure will be described with reference to the drawings.
[0019] [Overall configuration of electrical junction box] Fig. 1 is a perspective view of an electric junction box according to an embodiment. Fig. 2 is a plan view of an electric junction box according to an embodiment. In the following description, the descriptions of up, down, front, rear, left, and right follow the arrows shown in the drawings. For example, in Fig. 1, among the mutually orthogonal arrows X, Y, and Z, the direction indicated by the arrow X (third direction) is the left-right direction, the direction indicated by the arrow Y (second direction) is the front-rear direction, and the direction indicated by the arrow Z (first direction) is the up-down direction. However, these descriptions are merely examples, and for example, the direction X may be read as the front-rear direction or the up-down direction, the direction Y as the left-right direction or the up-down direction, and the direction Z as the front-rear direction or the left-right direction.
[0020] The electrical connection box 10 is a component that is connected between an automobile battery and multiple in-vehicle devices. The electrical connection box 10 is also called a junction box (JB). The electrical connection box 10 includes a case 11, a relay 12, and a bus bar 13.
[0021] The case 11 has an uneven upper surface, but is generally formed in a box shape that is flat in the up-down direction Z. The case 11 is formed in a substantially rectangular shape in a plan view. In this embodiment, the long side L1 of the case 11 is arranged along the left-right direction X, and the short side L2 is arranged along the front-rear direction Y. The front and rear surfaces of the case 11 are provided with protrusions 25 that protrude in the front-rear direction Y. Bosses 11a are provided at the four corners of the case 11 and at the middle of the long side L1. The bosses 11a are used to attach the case 11 to a mounting member 100 (see FIG. 7), such as a vehicle chassis or a battery box, with fasteners such as bolts.
[0022] The relay 12 is a component electrically connected between the battery and the in-vehicle device, and controls the on / off of an electric signal from the battery to the in-vehicle device. The relay 12 is, for example, a mechanical relay, and contains a coil, a spring, and the like inside. The relay 12 is attached to the upper surface side of the case 11, and the upper side is exposed. In this embodiment, as shown in FIG. 2, two relays 12 are attached to the case 11. Specifically, the two relays 12 are attached to the case 11 side by side in the left-right direction X. The relay 12 arranged on the left side has two terminals 12a on the front end surface. The relay 12 arranged on the right side has two terminals 12a on the rear end surface. In each relay 12, the two terminals 12a are arranged side by side in the left-right direction X. The number of relays 12 attached to the case 11 is not particularly limited, and may be one or three or more.
[0023] The relay 12 of this embodiment is a high-voltage relay that can operate at a voltage (e.g., 30 V or higher) higher than a normal voltage (e.g., 12 V, 24 V, etc.). The relay 12 is prone to becoming hot due to the application of a high voltage. For this reason, the electrical junction box 10 is provided with a heat dissipation structure 50, which will be described later.
[0024] 3 is a front view showing the relays and bus bars of the electrical junction box, in particular, the relay 12 and bus bar 13 on the left side in FIG. 1 to 3, bus bar 13 is a conductive member having one end 14 electrically connected to relay 12 and the other end 15 electrically connected to an in-vehicle device or another device such as the battery. Bus bar 13 is made of a metal such as copper, a copper alloy, aluminum, or an aluminum alloy. When relay 12 is turned on, a current flows through bus bar 13.
[0025] One bus bar 13 is attached to each of the two terminals 12a of relay 12. Bus bar 13 is formed by bending a single strip into an L shape. Bus bar 13 has a first piece 14 and a second piece 15 that are perpendicular to each other. First piece 14 is connected to relay 12, and second piece 15 is connected to another device. First piece 14 is formed with a connection hole 14a (see FIG. 8) for connection to relay 12. Second piece 15 is formed with a connection hole 15a for connecting an electric wire to another device.
[0026] FIG. 8 is a cross-sectional view taken along line BB in FIG. One end (first piece 14) of busbar 13 is attached to terminal 12a of relay 12 by connecting member 16. In this embodiment, connecting member 16 is a screw. Connecting member 16 is inserted into connecting hole 14a of first piece 14 of busbar 13, and attached to female screw hole 12b provided in terminal 12a of relay 12. Connecting member 16 is also used to attach a heat sink (first heat sink member) 51, which will be described later, to terminal 12a of relay 12. That is, connecting member 16 fixes both busbar 13 and heat sink 51 to terminal 12a of relay 12.
[0027] 3, second pieces 15 of busbars 13 arranged side by side on the left and right have different heights in the up-down direction Z. Specifically, second piece 15 of busbar 13 on the right side is arranged at a higher position than second piece 15 of busbar 13 on the left side.
[0028] [Case structure] Fig. 4 is a perspective view of a part of the lower case member of the case, seen from diagonally above. Fig. 5 is a perspective view of a part of the upper case member of the case, seen from diagonally above. Fig. 6 is a perspective view of a part of the upper case member of the case, seen from diagonally below. Figs. 4 to 6 show the shape of case 11 in the vicinity of relay 12 and bus bar 13 on the left side in Fig. 2. The structure of case 11 in the vicinity of relay 12 and bus bar 13 will be described below.
[0029] The case 11 is made of an insulating material, such as a synthetic resin material. The case 11 has an upper case member (first case member) 21 and a lower case member (second case member) 22. As shown in Fig. 5, upper case member 21 has top plate 21a and outer peripheral wall 21b provided on the outer periphery of top plate 21a. Relay stand 23 and busbar stand 24 are formed on the upper surface of top plate 21a. Relay 12 is placed and fixed on relay stand 23. Second piece 15 of busbar 13 is disposed on busbar stand 24 (see Fig. 3). First piece 14 of busbar 13 is connected to terminal 12a of relay 12 fixed to relay stand 23. The upper surface of protrusion 25 of case 11 is used as busbar stand 24.
[0030] 6, the lower surface of the top plate 21a of the upper case member 21 is provided with a plurality of ridges 44 and positioning protrusions (positioning portions) 45. The plurality of ridges 44 extend in the front-rear direction Y and are arranged side by side in the left-right direction X. The plurality of ridges 44 function as ribs for increasing the rigidity of the upper case member 21 against bending deformation.
[0031] The positioning protrusion 45 extends downward from the lower surface of the top plate 21a. The positioning protrusion 45 is formed in a cylindrical shape. The positioning protrusion 45 is used to position a plurality of members constituting a heat dissipation structure 50 (described later) relative to the case 11. The specific functions of the ribs 44 and the positioning protrusion 45 will be described later.
[0032] As shown in Fig. 4, the lower case member 22 has a bottom plate 22a and an outer peripheral wall 22b provided on the outer periphery of the bottom plate 22a. The lower case member 22 also has a first portion 58 and a second portion 59. The first portion 58 is disposed in an opening 22c formed in the bottom plate 22a. The second portion 59 refers to a portion of the lower case member 22 other than the first portion 58. The opening 22c and the first portion 58 are formed in a rectangular shape in a plan view. A protrusion 58c extending in the front-rear direction Y is formed in the center of an upper surface 58a of the first portion 58 in the left-right direction X.
[0033] The first portion 58 is formed of a material having a higher thermal conductivity than the second portion 59. For example, the first portion 58 is formed of a synthetic resin material such as nylon that contains an additive for increasing thermal conductivity. The second portion 59 is formed of a synthetic resin material such as polypropylene that contains glass fiber and talc. The upper case member 21 is also formed of the same synthetic resin material as the second portion 59.
[0034] 8, the bottom plate 22a of the lower case member 22 is disposed with the first portion 58 slightly misaligned upward. Therefore, an upper surface 58a of the first portion 58 protrudes upward from an upper surface of the surrounding second portion 59. A lower surface 58b of the first portion 58 is recessed upward from the lower surface of the surrounding second portion 59.
[0035] An upper heat dissipation sheet (second heat dissipation member) 52 of the heat dissipation structure 50 described below is disposed on an upper surface 58a of the first portion 58. A lower heat dissipation sheet (third heat dissipation member) 53 of the heat dissipation structure 50 is disposed on a lower surface 58b of the first portion 58.
[0036] 2, case 11 has a plurality of connecting portions 28-31 that connect upper case member 21 and lower case member 22. Hereinafter, the first to fourth connecting portions 28-31 in the vicinity of two bus bars 13 connected to relay 12 on the left side will be described.
[0037] The first connecting portion 28 connects the upper case member 21 and the lower case member 22 at the tip of the protruding portion 25 of the case 11. The second connecting portion 29 connects the upper case member 21 and the lower case member 22 at a position spaced apart from the first connecting portion 28 in the front-rear direction Y. The second connecting portion 29 is disposed on the inner side relative to the outer periphery of the case 11. The third connecting portion 30 and the fourth connecting portion 31 connect the upper case member 21 and the lower case member 22 on both sides of the protruding portion 25 in the left-right direction X.
[0038] The first connecting portion 28, the third connecting portion 30, and the fourth connecting portion 31 have the same configuration but differ in orientation, so in the following, the configuration of the first connecting portion 28 will be described as a representative.
[0039] As shown in FIG. 3, the first connecting portion 28 has an engaging portion 34 provided on the upper case member 21 and an engaged portion 35 provided on the lower case member 22. 5 and 6, the engaging portion 34 is formed in a substantially U-shape when viewed from the front. The engaging portion 34 has a claw receiving portion 34a extending in the left-right direction X at its lower end.
[0040] 4, the engaged portion 35 has a claw portion 35a that protrudes outward from the outer peripheral wall 22b of the lower case member 22. The claw portion 35a engages with the claw receiving portion 34a from above. This engagement connects the upper case member 21 and the lower case member 22 so that they do not separate in the vertical direction Z.
[0041] The third connecting portion 30 is provided on the left side surface of the protruding portion 25, and has a structure in which the first connecting portion 28 is rotated 90° to the left. The fourth connecting portion 31 is provided on the right side surface of the protruding portion 25, and has a structure in which the first connecting portion 28 is rotated 90° to the right.
[0042] As shown in Fig. 2, the second connecting portions 29 are provided at two locations aligned on the left and right so as to correspond to the two bus bars 13. As shown in Fig. 8, the second connecting portions 29 have an engaging portion 37 provided on the upper case member 21 and an engaged portion 38 provided on the lower case member 22. As also shown in Fig. 6, the engaging portion 37 protrudes downward from the lower surface of the top plate 21a of the upper case member 21. The engaging portion 37 is plate-shaped and disposed perpendicular to the front-rear direction Y. As also shown in Fig. 4, the engaged portion 38 protrudes upward from the bottom plate 22a of the lower case member 22.
[0043] FIG. 12 is an enlarged view of a portion D in FIG. A hook portion 37a that bends backward is formed at the lower end of the engaging portion 37. A hook portion 38a that bends forward is formed at the upper end of the engaged portion 38. The hook portion 37a of the engaging portion 37 and the hook portion 38a of the engaged portion 38 are engaged in the up-down direction Z. The engaging portion 37 is inserted into an opening 41 formed in the bottom plate 22a of the lower case member 22. The engaged portion 38 is inserted into an opening 40 formed in the upper case member 21. The engaging portion 37 is formed on the front edge of the opening 40, and the engaged portion 38 is formed on the rear edge of the opening 41.
[0044] An upper surface 37b of the hook portion 37a of the engaging portion 37 and a lower surface 38b of the hook portion 38a of the engaged portion 38 respectively constitute an engaging surface. The two engaging surfaces 37b, 38b are in contact with each other vertically. The two engaging surfaces 37b, 38b are inclined downward toward the front. Therefore, when a force is applied to the upper case member 21 and the lower case member 22 in a state where the engaging portion 37 and the engaged portion 38 are engaged with each other in a vertical direction, the engaging portion 37 and the engaged portion 38 are pulled toward each other in the front-rear direction due to the inclination of the engaging surfaces 37b, 38b. Therefore, the engaging portion 37 and the engaged portion 38 are engaged with each other more firmly, and the connection between the upper case member 21 and the lower case member 22 is maintained.
[0045] [Heat dissipation structure configuration] Fig. 7 is a cross-sectional view taken along line AA in Fig. 2. Fig. 9 is a perspective view showing components of the bus bar and heat dissipation structure. Fig. 10 is an exploded perspective view showing components of the bus bar and heat dissipation structure. 7 and 8, the heat dissipation structure 50 has a heat dissipation plate (first heat dissipation member) 51, an upper heat dissipation sheet (second heat dissipation member) 52, and a lower heat dissipation sheet (third heat dissipation member) 53. As shown in FIG. 10, two heat dissipation plates 51 and two upper heat dissipation sheets 52 are provided corresponding to the two bus bars 13. One lower heat dissipation sheet 53 is provided corresponding to the two heat dissipation plates 51 and the two upper heat dissipation sheets 52 arranged side by side on the left and right. As shown in FIG. 7 and 8, the lower part of the heat dissipation plate 51 and the upper heat dissipation sheet 52 are arranged in the accommodation space 27 formed between the upper case member 21 and the lower case member 22.
[0046] The heat sink 51 is made of metal. Specifically, the heat sink 51 is formed of the same material as the bus bar 13, for example, copper, a copper alloy, aluminum, or an aluminum alloy. The heat sink 51 is formed by bending a strip of plate into an L shape. The heat sink 51 has a first piece 55 and a second piece 56 that are perpendicular to each other.
[0047] 8, first piece 55 of heat sink 51 is attached to terminal 12a of relay 12 by connecting member 16. Specifically, first piece 55 has a connection hole 55a formed therethrough, into which connecting member 16 is inserted. First piece 55 of heat sink 51 is overlapped with first piece 14 of bus bar 13. First piece 55 of heat sink 51 is disposed between first piece 14 of bus bar 13 and relay 12. Heat generated in relay 12 is transferred from terminal 12a to both heat sink 51 and bus bar 13.
[0048] The lower end of the first piece 55 of the heat sink 51 passes through a slit 26 formed in the top plate 21 a of the upper case member 21 and is disposed within the case 11 . The second piece 56 of the heat sink 51 is disposed below the second piece 15 of the bus bar 13. The top plate 21a of the upper case member 21 is disposed between the second piece 56 of the heat sink 51 and the second piece 15 of the bus bar 13. Therefore, the second piece 15 of the bus bar 13, the top plate 21a of the upper case member 21, and the second piece 56 of the heat sink 51 are stacked from top to bottom in this order. The second piece 56 of the heat sink 51 constitutes a first laminated portion that is stacked on the top plate 21a of the upper case member 21. The second piece 15 of the bus bar 13 constitutes a second laminated portion that is stacked on the top plate 21a of the upper case member 21 and the first laminated portion 56.
[0049] As shown in FIG. 7, a plurality of ridges 44 are formed on the lower surface of the top plate 21a of the upper case member 21, and the lower ends of the ridges 44 contact the upper surface of the second piece 56 of the heat sink 51.
[0050] As shown in Figs. 7 and 8, the upper heat dissipation sheet 52 is laminated on the lower side of the second piece 56 of the heat dissipation plate 51. As shown in Fig. 10, the upper heat dissipation sheet 52 is a sheet material formed in a rectangular shape in a plan view. The upper heat dissipation sheet 52 is formed of a synthetic resin material having thermal conductivity, such as acrylic, other acrylic materials, silicone materials, etc. The upper heat dissipation sheet 52 is adhered to the lower surface of the second piece 56 of the heat dissipation plate 51. The upper heat dissipation sheet 52 is placed on the first portion 58 of the lower case member 22. Therefore, the upper heat dissipation sheet 52 is sandwiched between the second piece 56 of the heat dissipation plate 51 and the first portion 58 of the lower case member 22.
[0051] 7 and 8, the lower heat dissipation sheet 53 is laminated on the lower side of the first portion 58 of the lower case member 22. Therefore, the lower heat dissipation sheet 53 is disposed in an upwardly recessed portion of the lower surface of the bottom plate 22a of the lower case member 22. The lower heat dissipation sheet 53 is a sheet material formed in a rectangular shape in a plan view, as shown in Fig. 10. The lower heat dissipation sheet 53 is formed of a synthetic resin material having thermal conductivity, such as acrylic, other acrylic materials, silicone materials, etc.
[0052] 7 and 8, the lower surface of the lower heat dissipation sheet 53 is in contact with the upper surface of the mounting member 100 to which the electrical connection box 10 is to be attached. The heat dissipation plate 51, the upper heat dissipation sheet 52, the first portion 58, and the lower heat dissipation sheet 53 are sandwiched between the top plate 21a of the upper case member 21 and the mounting member 100 by attaching the boss portion 11a (see FIG. 1) of the case 11 to the mounting member 100 with a bolt or the like. In particular, the upper heat dissipation sheet 52 and the lower heat dissipation sheet 53 are compressed between the heat dissipation plate 51 and the first portion 58 of the lower case member 22, and between the first portion 58 and the mounting member 100, respectively. As a result, the heat dissipation plate 51, the upper heat dissipation sheet 52, the first portion 58, and the lower heat dissipation sheet 53 are in close contact with each other at their contact surfaces.
[0053] The relay 12 generates heat by opening and closing the internal contacts. The heat generated in the relay 12 is transferred from the terminal 12a to the heat sink 51 and the bus bar 13. The heat sink 51 has an upper heat sink sheet 52, a lower case member 22, and a lower heat sink sheet 53 laminated thereon, and has a larger heat capacity than the bus bar 13, so that the heat generated in the relay 12 is transferred to the heat sink 51 side rather than the bus bar 13. The heat transferred to the heat sink 51 is transferred to the mounting member 100 via the upper heat sink sheet 52, the lower case member 22 (first portion 58), and the lower heat sink sheet 53, and is dissipated from the mounting member 100 to the outside.
[0054] The upper heat dissipation sheet 52 is softer than the heat dissipation plate 51, and therefore adheres strongly to the heat dissipation plate 51 when compressed in the vertical direction Z. This allows efficient heat transfer between the heat dissipation plate 51 and the upper heat dissipation sheet 52. The upper heat dissipation sheet 52 and the lower heat dissipation sheet 53 are softer than the lower case member 22, and adhere strongly to the lower case member 22 (first portion 58) when compressed in the vertical direction Z. This allows efficient heat transfer between the lower case member 22 and the upper heat dissipation sheet 52 and the lower heat dissipation sheet 53.
[0055] The first portion 58 constituting the lower case member 22 is formed of a material having a higher thermal conductivity than the second portion 59. Therefore, the heat transferred from the upper heat dissipation sheet 52 to the first portion 58 is conducted through the first portion 58 with high efficiency and transferred to the lower heat dissipation sheet 53. Therefore, heat is efficiently transferred from the upper heat dissipation sheet 52 to the lower heat dissipation sheet 53, and the heat dissipation performance can be improved.
[0056] Furthermore, since only the first portion 58 of the lower case member 22 is formed from a material with high thermal conductivity, it can be manufactured more cheaply than if the entire lower case member 22 were formed from a material with high thermal conductivity, and the manufacturing cost of the electrical junction box 10 can be reduced.
[0057] Upper case member 21 is disposed between second piece 15 of busbar 13 and second piece 56 of heat sink 51, and upper case member 21 separates a power supply path on the busbar 13 side from a heat dissipation path on the heat sink 51 side into upper and lower sections. Therefore, heat generated in relay 12 can be efficiently transferred to the heat sink 51 side and dissipated.
[0058] The upper case member 21 has ridges 44 on the underside of the top plate 21a, and these ridges 44 suppress bending deformation such as warping of the top plate 21a. Therefore, the top plate 21a can uniformly press the heat dissipation plate 51 against the upper heat dissipation sheet 52, and the entire upper heat dissipation sheet 52 can be brought into close contact with the heat dissipation plate 51.
[0059] The protrusions 44 of the top plate 21a extend along the front-rear direction Y, which is the protruding direction of the protrusions 25. Since the tip (front end) of the protrusions 25 is easily bent and deformed in the up-down direction Z, by having the protrusions 44 extend along the front-rear direction Y, the bending deformation of the protrusions 25 can be effectively suppressed.
[0060] Since the top plate 21a is in contact with the heat sink 51 at the tip end faces of the ridges 44, it is possible to reduce the contact area with the heat sink 51. This makes it possible to suppress heat transfer from the heat sink 51 to the top plate 21a and promote heat dissipation to the upper heat sink sheet 52 side.
[0061] 8 and 12, in the bottom plate 22a of the lower case member 22, the engaged portion 38 of the second connecting portion 29 is formed in the vicinity of an opening 41 penetrating the bottom plate 22a in the up-down direction Z. In addition, as also shown in FIG. 4, the lower case member 22 has a wall portion 43 between the opening 41 and the heat sink 51, which protrudes upward toward the upper case member 21. This wall portion 43 is located on the front edge of the opening 41. A gap t is formed between the upper end of the wall portion 43 and the top plate 21a of the upper case member 21.
[0062] In this embodiment, the second connecting portion 29 is disposed behind the heat sink 51, and an opening 41 for inserting the engagement portion 37 of the second connecting portion 29 is formed in the lower case member 22. Therefore, the heat sink 51 and the mounting member 100 are disposed close to each other through a space. The heat sink 51 is a conductive member, and a voltage is applied from the terminal 12a of the relay 12, so that there is a possibility of short-circuiting to the mounting member 100 through the space. In this embodiment, a wall portion 43 is provided between the heat sink 51 and the mounting member 100, so that the insulation distance (creepage distance) between the heat sink 51 and the mounting member 100 can be extended, and the insulation between the heat sink 51 and the mounting member 100 can be improved.
[0063] FIG. 11 is a cross-sectional view taken along line CC in FIG. As shown in Fig. 8 and Fig. 11, the positioning protrusion 45 provided on the top plate 21a of the upper case member 21 penetrates the heat dissipation plate 51, the upper heat dissipation sheet 52, the first portion 58 of the lower case member 22, and the lower heat dissipation sheet 53 in the vertical direction Z. As also shown in Fig. 10, positioning holes 56a, 52a, 58d, and 53a penetrating in the vertical direction Z are formed in the second piece 56 of the heat dissipation plate 51, the upper heat dissipation sheet 52, the first portion 58, and the lower heat dissipation sheet 53. The positioning protrusion 45 of the upper case member 21 is inserted into these positioning holes 56a, 52a, 58d, and 53a to perform relative positioning of the upper case member 21, the heat dissipation plate 51, the upper heat dissipation sheet 52, the first portion 58, and the lower heat dissipation sheet 53. As a result, these members are disposed at appropriate positions.
[0064] The lower end 45a of the positioning protrusion 45 may simply be inserted into the lower heat dissipation sheet 53 without penetrating it. The lower end 45a of the positioning protrusion 45 may protrude downward from the lower heat dissipation sheet 53, as shown by an imaginary line in Fig. 8. In this case, the positioning of the electrical junction box 10 relative to the mounting base 100 can also be performed using the positioning protrusion 45 by fitting the lower end 45a of the positioning protrusion 45 into a recess (not shown) formed in the mounting base 100.
[0065] As shown in FIG. 10, the two heat sinks 51 arranged side by side have substantially the same external shape, so there is a risk of them being assembled in reverse when assembled to the case 11. The two heat sinks 51 of this embodiment have positioning holes 56a formed at different positions. For example, the left heat sink 51 has the positioning hole 56a arranged biased to the right, and the right heat sink 51 has the positioning hole 56a arranged biased to the left. Therefore, even if one tries to assemble the left and right heat sinks 51 in reverse, the positioning protrusions 45 of the upper case member 21 cannot be inserted into the positioning holes 56a, so that erroneous assembly of the left and right heat sinks 51 can be suppressed.
[0066] The positioning protrusion 45 may be provided on the lower case member 22. In this case, a positioning protrusion protruding upward from the first portion 58 of the lower case member 22 and inserted into the upper heat dissipation sheet 52, the heat dissipation plate 51, and the upper case member 21, and a positioning protrusion protruding downward from the first portion 58 and inserted into the lower heat dissipation sheet 53 may be provided.
[0067] 8, the heat sink 51 is connected to the terminal 12a of the relay 12. Therefore, heat generated at the contact points in the relay 12 can be efficiently transferred from the terminal 12a to the heat sink 51.
[0068] 8, heat sink 51 and bus bar 13 are overlapped at the position of terminal 12a of relay 12. Therefore, a voltage can be applied from terminal 12a to bus bar 13, and heat can be transferred from terminal 12a to heat sink 51.
[0069] [Variations] FIG. 13 is a cross-sectional view of an electric junction box according to a modified example, corresponding to a portion E in FIG. In the above-described embodiment, the first portion 58 of the lower case member 22 is disposed in the opening 22c formed in the second portion 59, and can freely move in the vertical direction Z within the opening 22c. In this modified example, the downward movement of the first portion 58 relative to the second portion 59 is restricted. Specifically, a recess 22e is formed on the upper side of the inner peripheral edge of the opening 22c formed in the bottom plate 22a. Meanwhile, a protrusion 58e protruding outward is formed on the upper side of the outer peripheral edge of the first portion 58, and the protrusion 58e is fitted into the recess 22e. As a result, the first portion 58 cannot pass downward through the opening 22c, and the downward movement is restricted.
[0070] The recess 22e and the protrusion 58e may be formed around the entire periphery of the opening 22c and the first portion 58, respectively, or may be formed on two opposing sides.
[0071] Moreover, the first portion 58 is formed thinner in the up-down direction Z than the second portion 59. An upper surface 58a of the first portion 58 and an upper surface 59a of the second portion 59 are disposed on the same plane. A lower surface 58b of the first portion 58 is disposed at a position recessed upward relative to a lower surface 59b of the second portion 59.
[0072] In this modification, the downward movement of first portion 58 relative to second portion 59 is restricted, so that when upper case member 21 and lower case member 22 are connected by first to fourth connecting portions 28 to 31, second piece 56 of heat sink 51 and upper heat sink sheet 52 are sandwiched and compressed between upper case member 21 and lower case member 22. This allows second piece 56 of heat sink 51 and upper heat sink sheet 52 to be tightly attached to each other, allowing efficient heat transfer between them.
[0073] In addition, since the first portion 58 is formed thinner than the second portion 59, heat can be transferred from the upper heat-dissipating sheet 52 to the lower heat-dissipating sheet 53 more efficiently.
[0074] 《Addendum》 In addition, at least a part of the above-mentioned embodiment and various modified examples may be arbitrarily combined with each other. In addition, the embodiment disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present disclosure is defined by the claims, and it is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]
[0075] 10: Electrical junction box 11: Case 11a: Boss section L1: Long side L2: Short side 12: Relay 12a: Terminal 12b: Female thread hole 13: Busbar 14: 1st piece 14a: Connection hole 15: Second piece (second laminated part) 15a: Connection hole 16: Connection parts 21: Upper case member (first case member) 21a: Tabletop 21b: Outer wall 22: Lower case member (second case member) 22a: Bottom plate 22b: Outer wall 22c: opening 22e: Recess 23: Relay stand 24: Busbar stand 25:Protrusion 26: Slit 28: 1st connection part 29:Second connection part 30:Third connection part 31: 4th connection part 34: Engagement part 34a: Claw receiving part 35: Engaged part 35a: Claw part 37: Engagement portion (second connecting portion) 37a: Hook part 37b: Engagement surface 38: Engaged part 38a: Hook part 38b: Engagement surface 40:Aperture 41:Aperture 43:Wall part 44: Projection 45: Positioning protrusion (positioning part) 50: Heat dissipation structure 51: Heat dissipation plate (first heat dissipation member) 52: Upper heat dissipation sheet (second heat dissipation member) 52a: Positioning hole 53: Lower heat dissipation sheet (third heat dissipation member) 53a: Positioning hole 55: 1st piece 55a: Connection hole 56: Second piece (first laminated part) 56a: Positioning hole 58: Part 1 58a:Top surface 58b: Bottom surface 58c: Projection 58d: Positioning hole 58e: Projection 59:Second part 59a:Top surface 59b: Bottom surface
Claims
1. Case and a relay attached to the case; a heat dissipation member connected to the relay in a heat-transferable manner, the case includes a first case member and a second case member connected to the first case member and forming an accommodation space between the first case member and a second case member, the heat dissipation member is disposed in the accommodation space by being stacked on the second case member, the second case member has a first portion that is laminated on the heat dissipation member and a second portion other than the first portion, The first portion is formed of a material having a higher thermal conductivity than the second portion, the first portion is recessed more than the second portion on a surface of the second case member opposite to the heat dissipation member, the electrical junction box further comprising a third heat dissipation member laminated on a surface of the first portion opposite to the heat dissipation member side.
2. Case and a relay attached to the case; a heat dissipation member connected to the relay in a heat-transferable manner, the case includes a first case member and a second case member connected to the first case member and forming an accommodation space between the first case member and a second case member, the heat dissipation member is disposed in the accommodation space by being stacked on the second case member, the second case member has a first portion that is laminated on the heat dissipation member and a second portion other than the first portion, The first portion is formed of a material having a higher thermal conductivity than the second portion, the first case member has a positioning portion that protrudes toward the heat dissipation member and is inserted into the heat dissipation member and the first portion.
3. The heat dissipation member includes a first heat dissipation member made of metal and connected to the relay in a heat-transferable manner; 3. The electrical junction box according to claim 1, further comprising: a second heat dissipation member made of a synthetic resin, the second heat dissipation member being arranged between the first heat dissipation member and the first portion and being laminated on the first heat dissipation member and the first portion.
4. 4. The electrical junction box according to claim 1, wherein the first portion is restricted from moving relative to the second portion in a direction opposite to the heat dissipation member.
Citation Information
Patent Citations
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