Bus bar routing structure

Abstract

A bus bar routing structure 100 according to the present disclosure comprises: a heat-generating component that generates heat when energized; a first fastening member; a fastening bus bar 70 that is electrically connected to the heat-generating component by being fastened by the first fastening member; and conductive bus bars 80, 90 that are electrically connected to the fastening bus bar 70. The fastening bus bar 70 comprises: a first connection portion 71 that is connected to the heat-generating component; a second connection portion 72 that is connected to the conductive bus bars 80, 90; and a fastening bus bar body 73 that connects the first connection portion 71 and the second connection portion 72. The conductive bus bars 80, 90 comprise: third connection portions 81, 91 that face the second connection portion 72 in a first direction and are connected thereto; and conductive bus bar bodies 82, 92 that extend from the third connection portions 81, 91.

Description

Busbar Wiring Structure

[0001] The present disclosure relates to a busbar wiring structure.

[0002] Conventionally, a fastening structure described in Japanese Patent Application Laid-Open No. 2023-82637 (hereinafter referred to as Patent Document 1) is known. This fastening structure includes a first fastened member made of metal, a second fastened member made of metal, and a fastening member that fastens and fixes the first fastened member and the second fastened member to each other.

[0003] Japanese Patent Application Laid-Open No. 2023-82637

[0004] In the above fastening structure, heat generated from a heat-generating component such as a relay is transmitted from the first fastened member to the fastening part, and not only to the fastening part but also to the second fastened member, which may result in a high-temperature state. When the second fastened member is in a high-temperature state, it leads to an increase in conductor resistance.

[0005] The busbar wiring structure of the present disclosure includes a heat-generating component that generates heat upon energization, a first fastening member, a fastening busbar that is electrically connected to the heat-generating component by being fastened by the first fastening member, and a conductive busbar that is electrically connected to the fastening busbar. The fastening busbar includes a first connection part connected to the heat-generating component, a second connection part connected to the conductive busbar, and a fastening busbar body that connects the first connection part and the second connection part. The conductive busbar includes a third connection part that faces and is connected to the second connection part in a first direction, and a conductive busbar body extending from the third connection part.

[0006] According to the present disclosure, an increase in the conductor resistance of the conductive busbar can be suppressed.

[0007] Figure 1 is a perspective view showing an electrical junction box according to Embodiment 1-1. Figure 2 is an exploded perspective view showing the electrical junction box according to Embodiment 1-1 with the upper case removed. Figure 3 is an exploded perspective view of the electrical junction box according to Embodiment 1-1 viewed from diagonally above. Figure 4 is an exploded perspective view of the electrical junction box according to Embodiment 1-1 viewed from diagonally below. Figure 5 is a bottom view showing the internal configuration of the electrical junction box according to Embodiment 1-1. Figure 6 is a cross-sectional view taken along line A-A in Figure 5. Figure 7 is an enlarged cross-sectional view of a part of Figure 6, showing the busbar wiring structure. Figure 8 is a cross-sectional view corresponding to Figure 7, showing the busbar wiring structure according to Embodiment 1-2. Figure 9 is a cross-sectional view corresponding to Figure 7, showing the busbar wiring structure according to Embodiment 1-3. Figure 10 is a perspective view showing an electrical junction box according to Embodiment 2-1. Figure 11 is an exploded perspective view showing the electrical junction box according to Embodiment 2-1 with the upper case removed. Figure 12 is an exploded perspective view of the electrical junction box according to Embodiment 2-1 viewed from diagonally above. Figure 13 is a front view showing the internal configuration of an electrical junction box according to Embodiment 2-1. Figure 14 is a cross-sectional view taken along line B-B of Figure 13. Figure 15 is an enlarged cross-sectional view of a part of Figure 14, showing a busbar wiring structure. Figure 16 is a cross-sectional view corresponding to Figure 15, showing a busbar wiring structure according to Embodiment 2-2. Figure 17 is a cross-sectional view corresponding to Figure 15, showing a busbar wiring structure according to Embodiment 2-3. Figure 18 is a cross-sectional view corresponding to Figure 15, showing a busbar wiring structure according to Embodiment 2-4. Figure 19 is a cross-sectional view corresponding to Figure 15, showing a busbar wiring structure according to Embodiment 2-5. Figure 20 is a cross-sectional view corresponding to Figure 15, showing a busbar wiring structure according to Embodiment 2-6. Figure 21 is a cross-sectional view corresponding to Figure 7, showing a busbar wiring structure according to Modification 1-4. Figure 22 is a cross-sectional view corresponding to Figure 8, showing a busbar wiring structure according to Modification 1-5. Figure 23 is an enlarged cross-sectional view showing part C of Figure 7. Figure 24 is an enlarged cross-sectional view of section D in Figure 7. Figure 25 is an enlarged cross-sectional view of section E in Figure 8. Figure 26 is an enlarged cross-sectional view of section F in Figure 8.Figure 27 is an enlarged cross-sectional view of section G in Figure 9. Figure 28 is an enlarged cross-sectional view of section H in Figure 16. Figure 29 is an enlarged cross-sectional view of section I in Figure 18.

[0008] [Description of Embodiments of the Disclosure] First, embodiments of the disclosure will be listed and described.

[0009] [1] The busbar routing structure of the present disclosure comprises a heat-generating component that generates heat when energized, a first fastening member, a fastening busbar that is electrically connected to the heat-generating component by being fastened by the first fastening member, and a conductive busbar that is electrically connected to the fastening busbar, wherein the fastening busbar comprises a first connection portion connected to the heat-generating component, a second connection portion connected to the conductive busbar, and a fastening busbar body connecting the first connection portion and the second connection portion, wherein the conductive busbar comprises a third connection portion that faces and is connected to the second connection portion in a first direction, and a conductive busbar body extending from the third connection portion.

[0010] The fastening busbar is fastened to the heat-generating component by a first fastening member. The first connection point and the heat-generating component are electrically connected via the first fastening member, and the heat generated in the heat-generating component is transferred to the first connection point via the first fastening member. The heat transferred to the first connection point is then transferred to the second connection point via the fastening busbar body. Since the second and third connection points face each other in the first direction and are electrically connected, the heat transferred to the second connection point is transferred to the third connection point. In other words, a conductive path is formed from the heat-generating component to the fastening busbar, and from the fastening busbar to the conductive busbar, and at the same time, a heat transfer path is also formed.

[0011] It is generally known that the conductivity resistance of metal materials increases and their physical strength decreases as the temperature rises. In the busbar wiring structure described above, the second connection point is connected to the third connection point at a position isolated from the heat-generating component, making it difficult for heat to be transferred from the heat-generating component to the conductive busbar. As a result, it is possible to make it difficult for heat to be transferred from the third connection point to the conductive busbar body in the conductive busbar. Therefore, the conductivity of the conductive busbar can be ensured.

[0012] Metallic materials, each possessing its own unique thermal and electrical conductivity, expand as the temperature rises, causing their conductive resistance to increase and their conductivity to decrease. Furthermore, high temperatures can lead to insufficient physical strength. Therefore, by designing the busbar routing structure so that the second connection point of the fastening busbar is connected to the third connection point of the conductive busbar at a position away from the heat-generating component, the fastening busbar itself can increase its heat capacity, dissipating the heat generated by the heat-generating component. This dissipation suppresses the increase in the busbar's conductive resistance, maintaining normal conductivity. It also contributes to resolving the insufficient physical strength of the busbar due to high temperatures. Thus, according to this disclosure, the increase in the busbar's conductive resistance can be suppressed by designing the busbar routing structure.

[0013] [2] In [1] above, it is preferable that at least one of the second connection portion or the third connection portion is thermally connected to the heat dissipation portion in the first direction. Since at least one of the second connection portion or the third connection portion is thermally connected to the heat dissipation portion, heat can be easily dissipated from the second connection portion or the third connection portion to the heat dissipation portion.

[0014] [3] In the above [1] or [2], it is preferable that the heat dissipation portion includes a heat conductive member made of a heat conductive material and a case in which the busbar wiring structure is housed.

[0015] The heat conduction member and case are specifically illustrated as examples of heat dissipation sections. For example, a heat conduction member is generally made of a thermal interface material that is inserted between a heat-generating electronic component and a cooling component (such as a heat sink) and plays the role of efficiently conducting and dissipating the generated heat.

[0016] [4] In any of the above [1] to [3], it is preferable that the second connection portion of the fastening busbar and the third connection portion of the conductive busbar are fastened together by the second fastening member.

[0017] The second fastening member allows the second and third connection points to be electrically and thermally connected. This method of connection using a fastening member allows for free combination of fastening busbars and conductive busbars regardless of their material. The second connection point of the fastening busbar and the third connection point of the conductive busbar are electrically connected by the second fastening member. For example, the fastening busbar and the conductive busbar can be mechanically and electrically connected via a second fastening member such as a bolt or nut.

[0018] [5] In any of the above [1] to [4], it is preferable that the fastening busbar is L-shaped and that the second connection portion and the heat-generating component do not overlap in the first direction.

[0019] The fastening busbar is L-shaped, and the heat-generating component connected to the fastening busbar and the second connection point do not overlap in the connection direction, making it easy to access from the first direction. This simplifies the assembly of the busbars and leads to improved work efficiency.

[0020] [6] In any of the above [1] to [5], it is preferable that the conductive busbar is made of aluminum or an aluminum alloy, and that at least one surface of the fastening busbar or the conductive busbar is subjected to a conductive surface treatment.

[0021] The conductive busbar is made of surface-treated aluminum or aluminum alloy. From the viewpoint of conductivity, pure aluminum can be used as the material for the conductive busbar, and from the viewpoint of strength, high-strength aluminum alloy can be used. Surface treatment such as plating can suppress the formation of an oxide film on at least one surface of the fastening busbar or the conductive busbar, thereby suppressing an increase in contact resistance between the fastening busbar and the conductive busbar.

[0022] [7] In any of the above [1] to [6], it is preferable that the busbar routing structure further comprises fastening washers made of a high-strength metal which has higher strength than pure aluminum, and which are electrically and thermally connected to the conductive busbars.

[0023] A fastening washer is sandwiched between the second connection point of the fastening busbar and the third connection point of the conductive busbar, and each busbar is electrically and thermally connected via the fastening washer. Although the busbars are subjected to axial force from the fastening members when fastened, the fastening washer is made of high-strength metal, so deformation of the fastening washer due to the axial force during fastening can be suppressed.

[0024] [8] In any of the above [1] to [7], it is preferable that at least one surface of the fastening bus bar or the fastening washer is subjected to a conductive surface treatment.

[0025] The fastening busbar is preferably made of a high-strength metal such as a copper alloy. The fastening washer is made of a high-strength metal that has higher strength than pure aluminum. From the viewpoint of conductivity, for example, pure aluminum can be used as the material for the fastening washer, and from the viewpoint of strength, for example, a high-strength aluminum alloy can be used. Surface treatment such as plating can suppress the formation of an oxide film on at least one surface of the fastening busbar or fastening washer, and can suppress an increase in contact resistance between the fastening busbar and the fastening washer.

[0026] [9] In any of the above [1] to [8], it is preferable that at least one surface of the conductive busbar or the fastening washer is subjected to a conductive surface treatment.

[0027] The conductive busbar is preferably made of surface-treated aluminum or an aluminum alloy. The fastening washer is made of a high-strength metal that has higher strength than pure aluminum. From the viewpoint of conductivity, for example, pure aluminum can be used as the material for the fastening washer, and from the viewpoint of strength, for example, a high-strength aluminum alloy can be used. Surface treatment such as plating can suppress the formation of an oxide film on at least one surface of the conductive busbar or the fastening washer, and can suppress an increase in contact resistance between the conductive busbar and the fastening washer.

[0028]

[10] In any of the above [1] to [9], it is preferable that the busbar routing structure further comprises fastening bolts that are electrically and thermally connected to the conductive busbars and are made of a high-strength metal that has higher strength than pure aluminum.

[0029]

[11] In any of the above [1] to

[10] , it is preferable that the fastening bolt is connected to the conductive busbar by welding or mechanical riveting.

[0030] The fastening bolts can be thermally and electrically connected to the conductive busbars, for example, by ultrasonic welding.

[0031]

[12] In any of the above [1] to

[11] , it is preferable that at least one surface of the fastening bus bar or the fastening bolt is subjected to a conductive surface treatment.

[0032] The fastening busbar is preferably made of a high-strength metal such as a copper alloy. The fastening bolt is made of a high-strength metal that has higher strength than pure aluminum. From the viewpoint of conductivity, for example, pure aluminum can be used as the material for the fastening bolt, and from the viewpoint of strength, for example, a high-strength aluminum alloy can be used. Surface treatment such as plating can suppress the formation of an oxide film on at least one surface of the fastening busbar or the fastening bolt, and can suppress an increase in contact resistance between the fastening busbar and the fastening bolt.

[0033]

[13] In any of the above [1] to

[12] , it is preferable that at least one surface of the conductive busbar or the fastening bolt is subjected to a conductive surface treatment.

[0034] The conductive busbar is preferably made of surface-treated aluminum or an aluminum alloy. The fastening bolt is made of a high-strength metal that has higher strength than pure aluminum. From the viewpoint of conductivity, for example, pure aluminum can be used as the material for the fastening bolt, and from the viewpoint of strength, for example, a high-strength aluminum alloy can be used. Surface treatment such as plating can suppress the formation of an oxide film on at least one surface of the conductive busbar or the fastening bolt, and can suppress an increase in contact resistance between the conductive busbar and the fastening bolt.

[0035]

[14] In any of the above [1] to

[13] , it is preferable that the busbar routing structure further comprises fastening nuts made of a high-strength metal which has higher strength than pure aluminum, and which are electrically and thermally connected to the conductive busbars.

[0036]

[15] In any of the above [1] to

[14] , it is preferable that the fastening nut is connected to the conductive bus bar by welding or mechanical riveting.

[0037] The fastening nuts can be thermally and electrically connected to the conductive busbars, for example, by ultrasonic welding.

[0038]

[16] In any of the above [1] to

[15] , it is preferable that at least one surface of the fastening bus bar or the fastening nut is subjected to a conductive surface treatment.

[0039] The fastening busbar is preferably made of a high-strength metal such as a copper alloy. The fastening nut is made of a high-strength metal that has higher strength than pure aluminum. From the viewpoint of conductivity, for example, pure aluminum can be used as the material for the fastening nut, and from the viewpoint of strength, for example, a high-strength aluminum alloy can be used. Surface treatment such as plating can suppress the formation of an oxide film on at least one surface of the fastening busbar or the fastening nut, thereby suppressing an increase in contact resistance between the fastening busbar and the fastening nut.

[0040]

[17] In any one of [1] to

[16] above, it is preferable that a conductive surface treatment is applied to at least one surface of the conductive bus bar or the fastening nut.

[0041] The conductive bus bar preferably consists of, for example, aluminum or an aluminum alloy that has been surface-treated. The fastening nut is formed of a high-strength metal that is stronger than pure aluminum. From the perspective of conductivity, for example, pure aluminum can be used as the material for the fastening nut, and from the perspective of strength, for example, a high-strength aluminum alloy can be used. Surface treatment such as plating can suppress the formation of an oxide film on at least one surface of the conductive bus bar or the fastening nut, and can suppress an increase in the contact resistance between the conductive bus bar and the fastening nut.

[0042]

[18] In any one of [1] to

[17] above, it is preferable that the bus bar wiring structure further includes a collar that is electrically and thermally connected to the conductive bus bar and is formed of a high-strength metal that is stronger than pure aluminum.

[0043]

[19] In any one of [1] to

[18] above, it is preferable that a conductive surface treatment is applied to at least one surface of the fastening bus bar or the collar.

[0044] The fastening bus bar preferably consists of, for example, a copper alloy which is a high-strength metal. The collar is formed of a high-strength metal that is stronger than pure aluminum. From the perspective of conductivity, for example, pure aluminum can be used as the material for the collar, and from the perspective of strength, for example, a high-strength aluminum alloy can be used. Surface treatment such as plating can suppress the formation of an oxide film on at least one surface of the fastening bus bar or the collar, and can suppress an increase in the contact resistance between the fastening bus bar and the collar.

[0045]

[20] In any one of [1] to

[19] above, it is preferable that a conductive surface treatment is applied to at least one surface of the conductive bus bar or the collar.

[0046] The bus bar for conduction is preferably made of, for example, aluminum or an aluminum alloy with a surface treatment. The collar is formed of a high-strength metal having higher strength than pure aluminum. From the viewpoint of conductivity, for example, pure aluminum can be used as the material, and from the viewpoint of strength, for example, a high-strength aluminum alloy can be used. By means of a surface treatment such as plating, it is possible to suppress the formation of an oxide film on at least one surface of the bus bar for conduction or the collar, and it is possible to suppress an increase in the contact resistance between the bus bar for conduction and the collar.

[0047]

[21] In any one of the above [1] to

[20] , it is preferable that the fastening bus bar is connected to the conduction bus bar by welding or mechanical caulking.

[0048] The fastening bus bar can be thermally and electrically connected to the conduction bus bar by, for example, ultrasonic welding.

[0049]

[22] In any one of the above [1] to

[21] , it is preferable that the fastening bus bar is configured such that the first connection portion and the second connection portion have different heights in the first direction, and the second connection portion and the heat-generating component do not overlap in the first direction.

[0050] The fastening bus bar is configured such that the first connection portion and the second connection portion have different heights in the first direction, and the heat-generating component connected to the fastening bus bar and the second connection portion do not overlap in the connection direction. Thus, access from the first direction is easy, so that the assembly work of the bus bars becomes easy, leading to an improvement in work efficiency.

[0051] [Details of Embodiments of the Disclosure] Embodiments of the Disclosure are described below. The Disclosure is not limited to these examples, but is indicated by the claims, and all modifications within the meaning and scope of equivalence to the claims are intended. In the drawings, some parts of the configuration may be exaggerated or simplified for illustrative purposes. Also, the dimensional ratios of the parts may differ in the drawings. In this specification, "orthogonal" includes not only strictly orthogonal surfaces but also surfaces that are approximately orthogonal to the extent that they function and have the effect of the embodiment. In Figures 1 to 22, for illustrative purposes, the surface treatment status described later is omitted on each surface of the illustrated configuration, with some exceptions, but each configuration is assumed to be appropriately surface-treated to allow conductivity.

[0052] Furthermore, in this specification, "facing" refers to the position where two surfaces or members are directly in front of each other, and includes not only cases where they are completely in front of each other, but also cases where they are partially in front of each other. Furthermore, in this specification, "facing" includes both cases where a member other than the two parts is interposed between the two parts, and cases where nothing is interposed between the two parts. In the following description, the direction indicated by arrow Z is described as upward, the direction indicated by arrow X is described as forward, and the direction indicated by arrow Y is described as to the right. The Z-axis direction is an example of the first direction. Note that in the case of multiple identical members, reference numerals may be assigned to only some of the members, and the reference numerals of the other members may be omitted.

[0053] <Embodiment 1-1> Embodiment 1-1 of the present disclosure will be described with reference to Figures 1 to 7 and Figures 23 to 24.

[0054] (Electrical junction box JB) The electrical junction box JB of this embodiment is mounted on a vehicle such as an electric vehicle or a hybrid vehicle and is placed in the power supply path from the battery to a load such as a motor. As shown in Figures 1 and 2, the electrical junction box JB is connected to external connection busbars 2 and 3. The external connection busbars 2 and 3 are for electrically connecting the electrical junction box JB to equipment (including a battery) located outside the electrical junction box JB. The external connection busbars 2 and 3 have portions that are located outside the electrical junction box JB.

[0055] External busbar 2 is electrically connected to the battery. External busbar 3 is electrically connected to the load. The connection between external busbars 2 and 3 and the electrical junction box JB is made by inserting bolts (not shown) into the respective bolt insertion holes BI1 and BI6 and fastening them together. As shown in Figures 2 to 4, the electrical junction box JB comprises a case 10, a first busbar 50, a first electronic component 4, an inter-electronic component busbar 6, a second electronic component 5, a first conductive busbar 80, a pair of fastening busbars 70, a relay 40, a second conductive busbar 90, and bolts (B2 to B5, B7 to B10).

[0056] The first electronic component 4 is a current sensor and the second electronic component 5 is a fuse, but the invention is not limited to these and may be a relay. The inter-electronic component busbar 6 is placed between the first electronic component 4 and the second electronic component 5 to form an electrical circuit. The case 10 corresponds to the heat dissipation section of this disclosure, and the relay 40 corresponds to the heat generating component of this disclosure. Bolts B2 to B5, B7 to B10 and each bolt (not shown) inserted through each bolt insertion hole BI1, BI6 are fastened together with nuts. Bolts B2 to B5, B7 to B10 and each bolt (not shown) inserted through each bolt insertion hole BI1, BI6, and each nut N, each washer M, and each collar S fastened to these bolts may be made of copper alloy or aluminum alloy, or they may have a surface treatment applied to the entire surface or to a part thereof to allow conductivity. The bolts B9 and B10, and the nuts N, N1, and N2 that are screwed onto each of the bolts B9 and B10, correspond to the second fastening member of this disclosure.

[0057] (Inter-electronic component busbar 6) As shown in Figures 3 and 4, the inter-electronic component busbar 6 is a component made by punching and bending a conductive metal plate. The inter-electronic component busbar 6 comprises a first electronic component side terminal 60 connected to the terminal portion 22 of the first electronic component 4 by a bolt B3, a second electronic component side terminal 61 connected to the terminal portion 32 of the second electronic component 5 by a bolt B4, and a main body portion 62 connecting the first electronic component side terminal 60 and the second electronic component side terminal 61. The main body portion 62 is housed in contact with the lower case 11 so that excess heat can be dissipated to the lower case 11.

[0058] (Case 10) Case 10 is made of synthetic resin and comprises a lower case 11 and an upper case 12. The upper case 12 is assembled on top of the lower case 11. When connecting the external connection busbars 2 and 3 to the electrical connection box JB by bolting, and the bolts are fastened from above, the upper case 12 is positioned above the lower case 11, as shown in Figures 1 to 4. Case 10 houses the busbar routing structure 100, which will be described later. The configuration and arrangement of each component of the electrical connection box JB will be described below.

[0059] As shown in Figures 2 to 4, the lower case 11 is formed in a tray shape that is long in the left-right direction. Inside the lower case 11, the first bus bar 50, the first electronic component 4, the inter-electronic component bus bar 6, the second electronic component 5, the first conductive bus bar 80, the pair of fastening bus bars 70, the relay 40, and the second conductive bus bar 90 are arranged in order from left to right. In Figures 2 to 4, the heat conductive members 14 such as heat dissipation sheets, which will be described later, are omitted, but the electrical junction box JB has heat conductive members 14 (see Figures 6, 7, 8, 9, 21, 22, 23, 26, and 27). Heat conductive members 14 may be placed on the entire surface or a part of the surface at the positions where the inner wall of the lower case 11 and the respective members 50, 4, 6, 5, 80, 70, 40, 90 of the electrical junction box JB and the respective fastening members of those members come into contact.

[0060] Bolts B2 and B3 are fastened from above to the terminal portions 22 formed on both the left and right sides of the first electronic component 4. Bolts B4 and B5 are fastened from above to the terminal portions 32 formed on both the left and right sides of the second electronic component 5. Bolts B7 and B8 are fastened from below to the terminals 42 of the relay 40, which will be described later.

[0061] As shown in Figures 1 to 4, the upper case 12 is lid-shaped. The upper case 12 comprises a housing section 12A, a first window section 12B, and a second window section 12C. The housing section 12A houses a first bus bar 50, a first electronic component 4, an inter-electronic component bus bar 6, a second electronic component 5, a first conductive bus bar 80, a pair of fastening bus bars 70, a relay 40, and a second conductive bus bar 90. The left end of the first bus bar 50 is connected to the external connection bus bar 2 in the first window section 12B. The right end of the second conductive bus bar 90 is connected to the external connection bus bar 3 in the second window section 12C.

[0062] (First Electronic Component 4) As shown in Figures 3 and 4, the first electronic component 4 comprises a main body portion 20, a cylindrical second main body portion 21 located on the upper surface of the main body portion 20 and opening upward, and two terminal portions 22 extending from both the left and right ends of the main body portion 20 in a rear view. The main body portion 20 is block-shaped. The terminal portions 22 are made of metal. The terminal portions 22 are thin plates in the vertical direction.

[0063] (Second electronic component 5) As shown in Figures 3 and 4, the second electronic component 5 comprises a main body 30, a pair of second main body parts 31 located at both the left and right ends of the main body 30, and two terminal parts 32 extending from both the left and right ends of the pair of second main body parts 31 in a rear view. The main body 30 is block-shaped. The terminal parts 32 are made of metal. The terminal parts 32 are thin plates in the vertical direction.

[0064] (First busbar 50) As shown in Figures 2 to 4, the first busbar 50 is a component made by punching and bending a conductive metal plate. The first busbar 50 includes a first electronic component side connection part 51 which is connected to the terminal part 22 of the first electronic component 4 by a bolt B2, a main body part 52, and an external connection part 53 which is electrically connected to the external connection busbar 3 via a bolt (not shown). The external connection part 53 and the main body part 52 are housed in contact with the lower case 11 so that excess heat can be dissipated to the lower case 11.

[0065] (Relay 40) Relay 40 is a large mechanical relay through which a large current from the battery is passed. Relay 40 is a heat-generating component that generates heat when energized. As shown in Figures 2 to 4, 6 and 7, relay 40 comprises a main body 41, a partition wall 43 extending downward from approximately the center of the lower surface of the main body 41 in the left-right direction, and a pair of left and right terminals 42 separated by the partition wall 43. The main body 41 is block-shaped. As shown in Figures 6 and 7, each terminal 42 is positioned so as to protrude slightly downward from the lower surface of the main body 41, and its protruding end face is a seating surface 44. Inside the terminal 42, a bottomed recess 45 is formed that opens downward and is recessed upward. A female screw is formed on the inner circumferential surface of the recess 45.

[0066] Each terminal 42 is designed to be fastened with bolts B7 and B8. Male threads are formed on the outer circumferential surface of the shafts of bolts B7 and B8. The male threads of bolts B7 and B8 are designed to enter the recesses 45 of terminal 42 and be screwed into the female threads. In this way, bolts B7 and B8 are fastened to each terminal 42. The first connecting portion 71, described below, is thermally and electrically connected to terminal 42 when bolt B7 is fastened to terminal 42. Bolts B7 and B8 correspond to the first fastening members of this disclosure.

[0067] (Fastening busbar 70) As shown in Figure 4, the fastening busbar 70 is a member made by punching and bending a conductive metal plate. A pair of fastening busbars 70 are arranged on the lower surface of the relay 40. The fastening busbar 70 comprises a first connection part 71 connected to the relay 40, a second connection part 72 connected to the conductive busbars 80 and 90 described below, and a fastening busbar body 73 (hereinafter referred to as "body 73") that connects the first connection part 71 and the second connection part 72. The first connection part 71 and the second connection part 72 are each arranged at different heights in the Z-axis direction (an example of the first direction).

[0068] The first connecting portion 71 and the second connecting portion 72 of the fastening bus bar 70 are arranged to be approximately perpendicular to the main body 73 in a side view in the Y-axis direction. That is, the fastening bus bar 70 has approximately perpendicular portions at two locations: between the first connecting portion 71 and the main body 73, and between the second connecting portion 72 and the main body 73 (see Figure 6). Therefore, the fastening bus bar 70 has a crank shape, and the second connecting portion 72 and the relay 40 do not overlap in the first direction (vertical direction). Here, not overlapping in the first direction means that when viewed from the first direction, the second connecting portion 72 and the relay 40 are not arranged to overlap.

[0069] In this embodiment, as an example of the shape of the fastening busbar 70, the first connecting portion 71 and the second connecting portion 72 are configured to have different heights in the Z-axis direction (an example of the first direction), and the shape of the fastening busbar 70 is shown to be crank-shaped. In addition to this, for example, the shape of the fastening busbar 70 may be such that the angle between the first connecting portion 71 and the main body 73 in the first direction is 120 degrees, or the angle between the second connecting portion 72 and the main body 73 in the first direction is 120 degrees, and the first connecting portion 71 and the second connecting portion 72 are configured to have different heights in the Z-axis direction (an example of the first direction). The fastening busbar 70 is configured such that the first connecting portion 71 and the second connecting portion 72 have different heights in the first direction, and since the relay 40 and the second connecting portion 72 do not overlap in the first direction, access from the first direction is easily made, which simplifies the assembly work of the fastening busbar 70 and the first conductive busbar 80, leading to improved work efficiency. In this specification, the size and shape of each fastening busbar 70 are substantially the same, so their description is omitted.

[0070] (Conductive busbars 80, 90) As shown in Figure 4, the first conductive busbar 80 and the second conductive busbar 90 are components made by punching and bending conductive metal plate material.

[0071] The first conductive busbar 80 includes a third connection portion 81 connected to the fastening busbar 70, a fourth connection portion 83 connected to the terminal portion 32 of the second electronic component 5, and a first conductive busbar body 82 (hereinafter referred to as "body 82") connecting the third connection portion 81 and the fourth connection portion 83. The second conductive busbar 90 includes a third connection portion 91 connected to the fastening busbar 70, an external connection portion 93 connected to the external connection busbar 3, and a second conductive busbar body 92 (hereinafter referred to as "body 92") connecting the third connection portion 91 and the external connection portion 93. The first conductive busbar 80 and the second conductive busbar 90 correspond to the conductive busbars of this disclosure. The bodies 82 and 92 correspond to the conductive busbar bodies of this disclosure.

[0072] (Busbar routing structure 100) In the following description, the busbar routing structure 100 for connecting the fastening busbar 70 and the first conductive busbar 80 will be explained. The busbar routing structure for connecting the second conductive busbar 90 and the fastening busbar 70 has a similar configuration, so its explanation will be omitted.

[0073] As shown in Figure 5, the relay 40 is located between the first conductive busbar 80 and the second conductive busbar 90. The first conductive busbar 80 is fastened to the second electronic component 5 by bolt B5. The second conductive busbar 90 is fastened to the external connection busbar 3 by inserting a bolt (not shown) through the bolt insertion hole BI6.

[0074] The busbar wiring structure 100 comprises a relay 40, a pair of fastening busbars 70, a terminal 42, a bolt B7, a first conductive busbar 80, a second conductive busbar 90, a fastening bolt B9 made of a high-strength metal with higher strength than pure aluminum, a fastening nut N, and a heat conductive member 14. The nut N corresponds to the fastening nut of this disclosure. As shown in Figures 6 and 7, the fastening busbar 70 is arranged on the lower surface of the main body 41 of the relay 40. The first connection portion 71 of the fastening busbar 70 has an insertion hole through which the bolt B7 is inserted. As shown in Figure 24, the bolt B7, the terminal 42, and the first connection portion 71 are surface-treated on all outer surfaces of each member so that they can conduct electricity with one another, and the bolt B7 is electrically and thermally connected to the terminal 42 and the first connection portion 71. The bolt B9 has a bolt head BX9. The third connecting portion 81 has a bolt insertion hole through which the bolt head BX9 is inserted. With the bolt head BX9 housed in this bolt insertion hole, the bolt head BX9 is joined to the third connecting portion 81 by mechanical riveting or welding. The connection portion JP100 between the bolt head BX9 and the third connecting portion 81 may be surface-treated, such as by plating, to make it electrically conductive, or it may be connected by mechanical riveting, welding, or other dissimilar material connection methods. Examples of surface treatments include plating, anodizing, thermal spraying, and painting. Examples of plating include nickel plating and tin plating. Therefore, the fastening bolt B9 is surface-treated or welded at the connection portion JP100 to be electrically conductive to the third connecting portion 81, and is electrically and thermally connected to the third connecting portion 81 (see Figure 23).

[0075] The second connecting portion 72 has a bolt insertion hole through which the bolt B9 is inserted and a nut connection portion that connects to the nut N. The nut N is electrically conductive. As shown in Figure 23, the fastening bolt B9, nut N, second connecting portion 72, and third connecting portion 81 are all surface-treated so that they are electrically conductive to each other, and the fastening bolt B9 is electrically and thermally connected to the nut N, second connecting portion 72, and third connecting portion 81 at the bolt insertion hole and nut connection portion. Note that the surface treatment of these members may be applied only to a portion of them as long as they are electrically conductive. The space SP1 between the bolt B9 and the second connecting portion 72 is the space through which the threads pass when the bolt B9 is inserted.

[0076] The second connection portion 72 and the third connection portion 81 face each other in the first direction. By fastening the nut N to the bolt B9, the second connection portion 72 and the third connection portion 81 are electrically connected and also thermally connected. The connection point between the fastening busbar 70 and the first conductive busbar 80 forms a conductive path, and good conductivity can be ensured by dissipating excess heat to the lower case 11. Although a bolt B9 and a nut N are given as an example of the second fastening members, the invention is not limited to these.

[0077] Heat from the relay 40 is transferred to the lower case 11 via the terminal 42, the first connection part 71, the main body 73, the second connection part 72, the bolt B9, and the third connection part 81. That is, heat is dissipated at the third connection part 81, reducing the amount of heat transferred from the first conductive busbar 80 to the second electronic component 5. A heat conduction member 14, made of a thermal conductive material such as a heat dissipation sheet or thermal grease, is interposed between the bolt head BX9, the third connection part 81, and the lower case 11. The heat conduction member 14 and the lower case 11 correspond to the heat dissipation portion of this disclosure. In this embodiment, the heat conduction member 14 is arranged between the bolt head BX9, the third connection part 81, and the lower case 11, but it is not necessarily required.

[0078] As an alternative configuration, for example, the second connection portion 72 of the fastening busbar 70 may be in contact with a heat-discharged portion other than the lower case 11. Alternatively, for example, the heat-discharged portion may be in contact with the side of the nut N opposite to the fastening busbar 70. The heat-discharged portion may have an insulating function. The heat-discharged portion may also be, for example, the case 10 of the electrical junction box JB or the housing of the battery pack. Alternatively, cooling may be performed by an air-cooling method without a heat-discharged portion.

[0079] (Material of fastening busbar 70) Here, it is preferable that the fastening busbar 70 has a high strength such that it is difficult to deform by axial force when bolted. Both the fastening busbar 70 and the first conductive busbar 80 are conductive, and it is preferable that the fastening busbar 70 has higher strength than the first conductive busbar 80. It is preferable that the fastening busbar 70 is made of a copper alloy, for example, which is a high-strength metal.

[0080] (Material of conductive busbars 80, 90) It is preferable to use aluminum busbars such as A1000 series or A6000 series for the conductive busbars 80, 90. Each conductive busbar 80, 90 is formed from aluminum or an aluminum alloy and is conductive. It is preferable that the surface of each conductive busbar 80, 90 is treated with a conductive surface treatment. For example, surface treatment such as plating can suppress the formation of an oxide film on the surface of the conductive busbars 80, 90, and can reduce the contact resistance between the fastening busbar 70 and the conductive busbars 80, 90. The surface of the fastening busbar 70 may also be treated with a conductive surface treatment. Furthermore, the entire surface or a part of the surface of each conductive busbar 80, 90 and the fastening busbar 70 may be treated with a surface treatment.

[0081] (Other connection methods between busbars) In this embodiment, bolts B9 were used as the connection method between the busbars, but the fastening busbar 70 and the first conductive busbar 80 may be connected by mechanical crimping, welding, or other dissimilar material connection methods. Examples of connection methods between busbars and the material of the first conductive busbar 80 used in such connection methods include the following: In the case of ultrasonic welding, copper or aluminum material; in the case of laser welding, aluminum material (which may be nickel-plated); in the case of electromagnetic pulse, copper or aluminum material; and in the case of mechanical crimping, copper or aluminum material can be selected as long as the mechanical crimping method is capable of joining dissimilar materials.

[0082] <Embodiment 1-2> Embodiment 1-2 of the present disclosure will be described with reference to Figures 8, 25, and 26. The electrical junction box JB according to Embodiment 1-2 is configured substantially the same as that of Embodiment 1-1, except for the busbar routing structure of Embodiment 1-1. Therefore, explanations of the same components and effects as in Embodiment 1-1 may be omitted.

[0083] (Busbar Routing Structure 101) The busbar routing structure 101 of this embodiment comprises a relay 40, a pair of fastening busbars 170, a terminal 42, a bolt B7, a first conductive busbar 80, a second conductive busbar 90, a fastening nut N1 made of a high-strength metal with higher strength than pure aluminum, a bolt B9, and a heat conductive member 14. The fastening busbar 170 is arranged on the lower surface of the main body 41 of the relay 40, as shown in Figure 8. The heat conductive member 14 is arranged between the nut N1 and the third connection part 81 and the lower case 11.

[0084] The fastening busbar 170 comprises a first connection portion 171 connected to the relay 40, a second connection portion 172 connected to the conductive busbars 80 and 90, and a fastening busbar body 173 (hereinafter referred to as "body 173") connecting the first connection portion 171 and the second connection portion 172.

[0085] The nut N1 is electrically conductive. For example, the nut N1 may be made of a copper alloy or an aluminum alloy, or it may be surface-treated in whole or in part to allow for electrical conductivity.

[0086] The second connecting portion 172 of the fastening busbar 70 has a through hole through which a bolt B9 is inserted and a nut connecting portion that connects to a nut N1. As shown in Figure 25, the bolt B9, nut N1, and second connecting portion 172 are surface-treated on all outer surfaces of each component so that they can be electrically connected to each other, and the second connecting portion 172 is electrically and thermally connected to the bolt B9 and nut N1 at the bolt through hole and nut connecting portion, respectively. The space SP2 between the bolt B9 and the second connecting portion 172 is the space through which the threads pass when the bolt B9 is inserted.

[0087] As shown in Figure 8, the third connecting portion 81 has a connection portion JP101 that connects to the nut N1. The connection portion JP101 between the nut N1 and the third connecting portion 81 may be surface-treated to be electrically conductive, or it may be connected by mechanical crimping, welding, or other dissimilar material connection methods. Examples of surface treatments include plating, anodizing, thermal spraying, and painting. Examples of platings include nickel plating and tin plating. Thus, the nut N1 is surface-treated or welded at the connection portion JP101 so as to be electrically conductive to the third connecting portion 81, and is electrically and thermally connected to the third connecting portion 81 (see Figure 26). As shown in Figure 26, the nut N1 and the third connecting portion 81 have surface treatments on their entire outer surface so as to be electrically conductive, but the surface treatment of these members may be applied only to a part of them as long as they are electrically conductive.

[0088] The second connection portion 172 and the third connection portion 81 face each other in the first direction. By interposing a nut N1 between the second connection portion 172 and the third connection portion 81 and fastening a bolt B9 to the nut N1, the second connection portion 172 and the third connection portion 81 are electrically connected and also thermally connected. Heat from the relay 40 is transmitted to the lower case 11 via the terminal 42, the first connection portion 171, the main body 173, the second connection portion 172, the nut N1, and the third connection portion 81. In other words, the connection point between the fastening busbar 170 and the first conductive busbar 80 forms a conductive path, and good conductivity can be ensured by releasing excess heat to the lower case 11. Heat is dissipated at the third connection portion 81, reducing the amount of heat transmitted from the first conductive busbar 80 to the second electronic component 5.

[0089] <Embodiment 1-3> Embodiment 1-3 of the present disclosure will be described with reference to Figures 9 and 27. The electrical junction box JB according to Embodiment 1-3 is configured substantially the same as that of Embodiment 1-1, except for the busbar routing structure of Embodiment 1-1. Therefore, explanations of the same components and effects as in Embodiment 1-1 may be omitted.

[0090] (Bus bar routing structure 102) The bus bar routing structure 102 of this embodiment comprises a relay 40, a pair of fastening bus bars 70, a bolt B7, a terminal 42, a first conductive bus bar 80, a second conductive bus bar 90, a square collar S made of a high-strength metal with higher strength than pure aluminum, a bolt B9, and a heat conductive member 14. The fastening bus bars 70 are arranged along the lower surface of the main body 41 of the relay 40, as shown in Figure 9. The bolt head BX9 is fixed embedded in the heat conductive member 14, and its upper surface is connected to the square collar S. The heat conductive member 14 and the lower case 11 correspond to the heat dissipation portion of this disclosure.

[0091] The square collar S is conductive. The square collar S is connected to the third connecting portion 81 in the radial direction of the bolt B9 and has a surface that connects to the second connecting portion 72 in the axial direction of the bolt B9. The second connecting portion 72 has a surface that connects to the nut N. The square collar S and the second connecting portion 72 have a bolt insertion hole for the bolt B9. The second connecting portion 72 and the third connecting portion 81 are electrically connected via the square collar S. In detail, as shown in Figure 27, the bolt B9, the nut N, the second connecting portion 72, the square collar S, and the third connecting portion 81 have surface treatment applied to their entire outer surfaces so that they are electrically conductive to each other in the insertion hole and each connecting surface. The spaces SP3 and SP4 between the bolt B9 and the second connecting portion 72 and between the bolt B9 and the square collar S are spaces through which the threads pass when the bolt B9 is inserted.

[0092] The second connection portion 72 and the third connection portion 81 face each other in the first direction. By fastening the nut N to the bolt B9, the second connection portion 72 and the third connection portion 81 are electrically connected and also thermally connected. Heat from the relay 40 is transmitted to the lower case 11 via the terminal 42, the first connection portion 71, the main body 73, the second connection portion 72, the square collar S, the bolt head BX9, and the heat conductive member 14, or from the square collar S to the lower case 11 via the third connection portion 81 and the heat conductive member 14. In other words, the connection point between the fastening busbar 70 and the first conductive busbar 80 forms a conductive path, and good conductivity can be ensured by releasing excess heat to the lower case 11. Heat is dissipated at the third connection portion 81, reducing the amount of heat transmitted from the first conductive busbar 80 to the second electronic component 5.

[0093] For example, the square collar S is made of a high-strength metal such as a copper alloy, or high-strength aluminum with a plating on its surface. Therefore, deformation of the square collar S due to the axial force during fastening can be suppressed. Also, as shown in Figure 9, the square collar S shown has a surface treatment such as plating applied to the connection portion JP102 with the third connection portion 81 of the first conductive busbar 80 to reduce contact resistance, but the connection portion JP102 may also be formed by welding. Examples of surface treatments include plating, anodizing, thermal spraying, and painting. Examples of plating types include nickel plating and tin plating. Note that the square collar S corresponds to the color of this disclosure.

[0094] <Embodiment 2-1> In Embodiment 1-1, the terminals 42 of the relay 40 were arranged vertically with the terminals 42 facing downwards. However, in the electrical junction box JB2 according to Embodiment 2-1, the terminals 42 of the relay 40 are arranged with the terminals 42 facing forward, which is different from Embodiment 1-1. In addition, the configuration of the upper case 12 has been partially changed accordingly, but other aspects are the same as in Embodiment 1-1, so their explanation will be omitted. In the upper case 13 of Embodiment 2-1, the position corresponding to the relay 40 does not protrude upwards and is formed flat (see Figures 10 to 13). In Figures 11 and 12, the illustration of the heat conductive member 14 such as a heat dissipation sheet is omitted, but the electrical junction box JB2 has a heat conductive member 14 (see Figures 14, 15, 16, 17, 18, 19, 20, 28, and 29).

[0095] (Busbar wiring structure 200) As shown in Figure 14, the busbar wiring structure 200 of this embodiment includes a relay 40, a pair of fastening busbars 270, a terminal 42, a bolt B7, a first conductive busbar 80, a second conductive busbar 90, a fastening bolt B9 made of a high-strength metal with higher strength than pure aluminum, a nut N, and a heat conductive member 14.

[0096] As shown in Figures 14 and 15, the fastening busbar 270 is positioned on the front surface of the main body 41 of the relay 40. The first connecting portion 271 of the fastening busbar 270 has a through hole through which a bolt B7 is inserted. The bolt B9 has a bolt head BX9. The third connecting portion 81 has a bolt insertion hole through which the bolt head BX9 is inserted. With the bolt head BX9 housed in this bolt insertion hole, the bolt head BX9 is joined to the third connecting portion 81 by mechanical riveting or welding. The connection portion JP200 between the bolt head BX9 and the third connecting portion 81 may be surface-treated with plating or other methods to make it conductive, or it may be connected by mechanical riveting, welding or other dissimilar material connection methods. Examples of surface treatments include plating, anodizing, thermal spraying, and painting. Examples of plating include nickel plating and tin plating. Therefore, the fastening bolt B9 is surface-treated or welded at the connection point JP200 so as to be electrically conductive to the third connection point 81, and is electrically and thermally connected to the third connection point 81. Note that the surface treatment of these components may be applied to the entire outer surface or only a part of it, as long as it is electrically conductive.

[0097] The fastening busbar 270 includes a first connection portion 271 connected to the relay 40 and a second connection portion 272 connected to the first conductive busbar 80. The first connection portion 271 and the second connection portion 272 are arranged orthogonally in a side view. That is, the fastening busbar 270 is L-shaped, and the second connection portion 272 and the relay 40 do not overlap in the first direction (vertical direction).

[0098] The second connection portion 272 and the third connection portion 81 face each other in the first direction. By fastening the nut N to the bolt B9, the second connection portion 272 and the third connection portion 81 are electrically connected and also thermally connected. The connection point between the fastening busbar 270 and the first conductive busbar 80 forms a conductive path, and good conductivity can be ensured by dissipating excess heat to the lower case 11. Heat from the relay 40 is transmitted to the lower case 11 via the terminal 42, the first connection portion 271, the second connection portion 272, and the third connection portion 81. That is, heat is dissipated at the third connection portion 81, and the heat transmitted from the first conductive busbar 80 to the second electronic component 5 is reduced.

[0099] The fastening busbar 270 is L-shaped, and the relay 40 and the second connection part 272 do not overlap in the first direction, making it easy to access from the first direction. This simplifies the assembly work between the fastening busbar 270 and the first conductive busbar 80, leading to improved work efficiency.

[0100] <Embodiment 2-2> Embodiment 2-2 of the present disclosure will be described with reference to Figures 16 and 28. Since the electrical junction box JB2 according to Embodiment 2-2 is configured substantially the same as that of Embodiments 1-1, 1-2, and 2-1, explanations of the same components and effects as those of Embodiments 1-1, 1-2, and 2-1 may be omitted.

[0101] (Busbar Routing Structure 201) The busbar routing structure 201 of this embodiment comprises a relay 40, a pair of fastening busbars 270, a terminal 42, a bolt B7, a first conductive busbar 80, a second conductive busbar 90, a fastening nut N2 made of a high-strength metal with higher strength than pure aluminum, a bolt B9, and a heat conductive member 14. The fastening busbars 270 are arranged on the front surface of the main body 41 of the relay 40, as shown in Figure 16. The length of the nut N2 is shorter than that of the nut N1 in Figure 8. The material of the nut N2 is the same as that of the nut N1, and the nut N2 is conductive. For example, the material of the nut N2 may be a copper alloy or an aluminum alloy, or it may be surface-treated on all or part of the surface to allow conductivity.

[0102] The fastening busbar 270 includes a first connection portion 271 connected to the relay 40 and a second connection portion 272 connected to the first conductive busbar 80. The first connection portion 271 and the second connection portion 272 are arranged orthogonally in a side view. That is, the fastening busbar 270 is L-shaped, and the second connection portion 272 and the relay 40 do not overlap in the Z-axis direction (an example of the first direction).

[0103] The second connecting portion 272 of the fastening busbar 270 has a through hole through which the bolt B9 is inserted and a nut connecting portion for connecting to the nut N2. The third connecting portion 81 has a connecting portion JP201 for connecting to the nut N2. As shown in Figure 28, the bolt B9, nut N2, second connecting portion 272, and third connecting portion 81 are all surface-treated to enable electrical conductivity between them. At the nut connecting portion and the connecting portion JP201 for connecting to the nut N2, the second connecting portion 272 is electrically and thermally connected to the bolt B9, nut N2, and third connecting portion 81, respectively. The space SP5 between the bolt B9 and the second connecting portion 272 is the space through which the threads of the bolt B9 pass when it is inserted. Furthermore, the bolt B9, nut N2, second connecting portion 272, and third connecting portion 81 may be connected at the nut connecting portion and the connecting portion JP201 by surface treatment, mechanical crimping, welding, or other dissimilar material connection methods. Examples of surface treatments include plating, anodizing, thermal spraying, and painting. Examples of plating include nickel plating and tin plating. Thus, the nut N2 is surface-treated or welded to the third connecting portion 81 so as to be electrically conductive, and is electrically and thermally connected to the third connecting portion 81 at the connecting portion JP201 (see Figure 28). Note that the surface treatment of these components may be applied only to a portion of them as long as they are electrically conductive. Furthermore, the space SP5 between the bolt B9 and the second connecting portion 272 is the space through which the threads pass when the bolt B9 is inserted.

[0104] The second connection portion 272 and the third connection portion 81 face each other in the first direction. By interposing a nut N2 between the second connection portion 272 and the third connection portion 81 and fastening a bolt B9 to the nut N2, the second connection portion 272 and the third connection portion 81 are electrically connected and also thermally connected. Heat from the relay 40 is transmitted to the lower case 11 via the terminal 42, the first connection portion 271, the second connection portion 272, the nut N2, and the third connection portion 81. In other words, heat is dissipated at the third connection portion 81, reducing the amount of heat transmitted from the first conductive busbar 80 to the second electronic component 5.

[0105] <Embodiment 2-3> Embodiment 2-3 of the present disclosure will be described with reference to Figure 17. Since the electrical junction box JB2 according to Embodiment 2-3 is configured substantially the same as that of Embodiments 1-1, 1-3, and 2-1, explanations of the same components and effects as those of Embodiments 1-1, 1-3, and 2-1 may be omitted.

[0106] (Busbar routing structure 202) The busbar routing structure 202 of this embodiment comprises a relay 40, a pair of fastening busbars 270, a bolt B7, a terminal 42, a first conductive busbar 80, a second conductive busbar 90, and a square collar S made of a high-strength metal that has greater strength than pure aluminum. The bolt head BX9 is fixed embedded in the heat conductive member 14, and its upper surface is connected to the square collar S. The fastening busbars 270 are arranged on the front surface of the main body 41 of the relay 40, as shown in Figure 17.

[0107] The fastening busbar 270 includes a first connection portion 271 connected to the relay 40 and a second connection portion 272 connected to the first conductive busbar 80. The first connection portion 271 and the second connection portion 272 are arranged orthogonally in a side view. That is, the fastening busbar 270 is L-shaped, and the second connection portion 272 and the relay 40 do not overlap in the first direction.

[0108] The square collar S is conductive. The square collar S has a connection portion JP202 that connects to the third connection portion 81 in the radial direction of the bolt B9, and a surface that connects to the second connection portion 272 in the axial direction of the bolt B9. The second connection portion 272 and the third connection portion 81 are electrically connected via the square collar S. In detail, as in Embodiment 1-3, the bolt B9, nut N, second connection portion 272, square collar S, and third connection portion 81 are surface-treated to be electrically conductive to each other. It is preferable that the connection portion JP202 of the square collar S with the third connection portion 81 be surface-treated, such as plating, or welded to reduce contact resistance. Examples of surface treatments include plating, anodizing, thermal spraying, and painting. Examples of plating include nickel plating and tin plating. Note that the surface treatment of these components may be applied to the entire outer surface or to a part thereof, as long as it is electrically conductive.

[0109] The second connection portion 272 and the third connection portion 81 face each other in the first direction. By fastening the nut N to the bolt B9, the second connection portion 272 and the third connection portion 81 are electrically connected and also thermally connected. Heat from the relay 40 is transmitted to the lower case 11 via the terminal 42, the first connection portion 271, the second connection portion 272, the square collar S, the bolt head BX9, and the heat conductive member 14, or from the square collar S to the lower case 11 via the third connection portion 81 and the heat conductive member 14. In other words, the connection point between the fastening busbar 270 and the first conductive busbar 80 forms a conductive path, and good conductivity can be ensured by releasing excess heat to the lower case 11. Heat is dissipated at the third connection portion 81, reducing the amount of heat transmitted from the first conductive busbar 80 to the second electronic component 5.

[0110] <Embodiment 2-4> Embodiment 2-4 of the present disclosure will be described with reference to Figures 18 and 29. Since the electrical junction box JB2 according to Embodiment 2-4 is configured substantially the same as that of Embodiments 1-1 and 2-1, explanations of the same components and effects as those of Embodiments 1-1 and 2-1 may be omitted.

[0111] (Busbar Routing Structure 203) The busbar routing structure 203 of this embodiment comprises a relay 40, a pair of fastening busbars 270, a bolt B7, a terminal 42, a first conductive busbar 80, a second conductive busbar 90, a fastening washer M made of a high-strength metal with higher strength than pure aluminum, a bolt B9, and a heat conductive member 14. The bolt head BX9 is fixed embedded in the heat conductive member 14, and its upper surface is connected to the fastening washer M. The fastening busbar 270 is arranged on the front surface of the main body 41 of the relay 40, as shown in Figure 18.

[0112] The fastening busbar 270 includes a first connection portion 271 connected to the relay 40 and a second connection portion 272 connected to the first conductive busbar 80. The first connection portion 271 and the second connection portion 272 are arranged orthogonally in a side view. That is, the fastening busbar 270 is L-shaped, and the second connection portion 272 and the relay 40 do not overlap in the first direction.

[0113] The fastening washer M is electrically conductive. The fastening washer M is connected to the second connecting portion 272 axially above the bolt B9 and has a surface that connects to the third connecting portion 81 axially below the bolt B9. The second connecting portion 272 has a surface that connects to the nut N. The fastening washer M, the second connecting portion 272, and the third connecting portion 81 all have a bolt insertion hole for the bolt B9. The second connecting portion 272 and the third connecting portion 81 are electrically connected to the bolt B9 via the fastening washer M. In detail, as shown in Figure 29, the bolt B9, the nut N, the second connecting portion 272, the fastening washer M, and the third connecting portion 81 have surface treatment applied to their entire outer surfaces so that they are electrically conductive to each other. Furthermore, the spaces SP6, SP7, and SP8 between the second connecting portion 272, the fastening washer M, and the third connecting portion 81 and the bolt B9 are spaces through which the threads pass when the bolt B9 is inserted.

[0114] The second connection portion 272 and the third connection portion 81 face each other in the first direction. By placing a fastening washer M between the second connection portion 272 and the third connection portion 81 and fastening a nut N to the bolt B9, the second connection portion 272 and the third connection portion 81 are electrically connected via the fastening washer M and are also thermally connected. Heat from the relay 40 is transmitted to the lower case 11 via the terminal 42, the first connection portion 271, the second connection portion 272, the fastening washer M, the third connection portion 81, the bolt head BX9, and the heat conductive member 14, or from the third connection portion 81 to the lower case 11 via the heat conductive member 14. In other words, the part where the fastening busbar 270 and the first conductive busbar 80 are connected forms a conductive path, and good conductivity can be ensured by releasing excess heat to the lower case 11. At the third connection point 81, heat is dissipated, reducing the heat transferred from the first conductive busbar 80 to the second electronic component 5.

[0115] For example, the fastening washer M may be a washer with a round outer shape. Such a fastening washer M is made of a high-strength metal such as a copper alloy, or high-strength aluminum with a plating on its surface. Therefore, deformation of the fastening washer M due to the axial force during fastening can be suppressed. Also, as shown in Figure 18, the connection portion JP203 of the third connection portion 81 of the first conductive busbar 80 of the fastening washer M is subjected to surface treatment such as plating or welding to reduce contact resistance. Examples of surface treatments include plating, anodizing, thermal spraying, and painting. Examples of plating types include nickel plating and tin plating.

[0116] <Embodiment 2-5> Embodiment 2-5 of the present disclosure will be described with reference to Figure 19. Since the electrical junction box JB2 according to Embodiment 2-5 is configured substantially the same as that of Embodiments 1-1, 2-1, and 2-4, explanations of the same components and effects as those of Embodiments 1-1, 2-1, and 2-4 may be omitted.

[0117] (Busbar routing structure 204) The busbar routing structure 204 comprises a relay 40, a pair of fastening busbars 270, a bolt B7, a terminal 42, a first conductive busbar 80, a second conductive busbar 90, a bolt B9, and a heat conductive member 14. The bolt head BX9 is fixed embedded in the heat conductive member 14, and its upper surface is connected to the lower surface of the third connection part 81. The fastening busbars 270 are arranged on the front surface of the main body 41 of the relay 40, as shown in Figure 19.

[0118] The fastening busbar 270 includes a first connection portion 271 connected to the relay 40 and a second connection portion 272 connected to the first conductive busbar 80. The first connection portion 271 and the second connection portion 272 are arranged orthogonally in a side view. That is, the fastening busbar 270 is L-shaped, and the second connection portion 272 and the relay 40 do not overlap in the first direction.

[0119] At least one surface of the fastening busbar 270 or the first conductive busbar 80 is treated with a conductive surface treatment. In this embodiment, the entire circumference of the surface of the first conductive busbar 80 is plated as surface treatment JP204. In this embodiment, the first conductive busbar 80 is plated or welded with a type of surface treatment JP204 that reduces contact resistance at the connection point with the second connecting part 272. In this embodiment, the first conductive busbar 80 is made of high-strength aluminum or a high-strength metal that is stronger than pure aluminum. Examples of plating types include nickel plating and tin plating. The surface treatment JP204 may be applied or welded in a conductive manner to a part of the connection point with the second connecting part 272 rather than the entire circumference of the surface of the first conductive busbar 80. The spaces SP9 and SP10 between the second connecting part 272, the third connecting part 81, and the bolt B9 are spaces through which the threads pass when the bolt B9 is inserted.

[0120] The second connection portion 272 and the third connection portion 81 face each other in the first direction. By fastening the nut N to the bolt B9, the second connection portion 272 and the third connection portion 81 are electrically connected and also thermally connected. Heat from the relay 40 is transmitted to the lower case 11 via the terminal 42, the first connection portion 271, the second connection portion 272, the bolt head BX9, and the heat conductive member 14, or from the third connection portion 81 to the lower case 11 via the heat conductive member 14. In other words, the connection point between the fastening busbar 270 and the first conductive busbar 80 forms a conductive path, and good conductivity can be ensured by releasing excess heat to the lower case 11. Heat is dissipated at the third connection portion 81, reducing the amount of heat transmitted from the first conductive busbar 80 to the second electronic component 5.

[0121] <Embodiment 2-6> Embodiment 2-6 of the present disclosure will be described with reference to Figures 10 to 13 and Figure 20. Since the electrical junction box JB2 according to Embodiment 2-6 is configured substantially the same as that of Embodiments 1-1, 2-1, and 2-5, explanations of the same components and effects as those of Embodiments 1-1, 2-1, and 2-5 may be omitted.

[0122] (Busbar routing structure 205) The busbar routing structure 205 comprises a relay 40, a pair of fastening busbars 270, a bolt B7, a terminal 42, a first conductive busbar 80, a second conductive busbar 90, and a heat conductive member 14. The fastening busbars 270 are arranged on the front surface of the main body 41 of the relay 40, as shown in Figure 20.

[0123] The fastening busbar 270 includes a first connection portion 271 connected to the relay 40 and a second connection portion 272 connected to the first conductive busbar 80. The first connection portion 271 and the second connection portion 272 are arranged orthogonally in a side view. That is, the fastening busbar 270 is L-shaped, and the second connection portion 272 and the relay 40 do not overlap in the first direction.

[0124] The second connection portion 272 and the third connection portion 81 face each other in the first direction. The fastening busbar 270 and the first conductive busbar 80 are connected between the second connection portion 272 and the third connection portion 81 by mechanical crimping or welding. The connection portion is indicated by JP205. That is, the fastening busbar 270 is connected to the first conductive busbar 80 by a dissimilar material connection method such as welding or mechanical crimping. Thus, the second connection portion 272 and the third connection portion 81 are electrically connected and also thermally connected. Heat from the relay 40 is transmitted to the lower case 11 via the terminal 42, the first connection portion 271, the second connection portion 272, the third connection portion 81, and the heat conductive member 14. That is, the connection portion between the fastening busbar 270 and the first conductive busbar 80 forms a conductive path, and good conductivity can be ensured by releasing excess heat to the lower case 11. At the third connection point 81, heat is dissipated, reducing the heat transferred from the first conductive busbar 80 to the second electronic component 5.

[0125] Furthermore, the busbar routing structure 205 of this embodiment differs from the busbar routing structures 100, 101, 102, 200, 201, 202, 203, and 204 of other embodiments in that it does not use bolts B9 or nuts N to connect the second connection parts 72, 172, and 272 of the fastening busbars 70, 170, and 270 to the third connection part 81 of the first conductive busbar 80.

[0126] <Modification 1-4> Modification 1-4 of the present disclosure will be described with reference to Figure 21. The electrical junction box JB according to Modification 1-4 is configured substantially the same as that of Embodiment 1-1, except for the configuration of the busbar wiring structure of Embodiment 1-1. Therefore, explanations of the same components and effects as in Embodiment 1-1 may be omitted.

[0127] (Busbar routing structure 103) The busbar routing structure 103 of this embodiment includes a relay 40, a pair of fastening busbars 70, a terminal 42, a bolt B7, a first conductive busbar 180, a second conductive busbar 190, a fastening bolt B9 made of a high-strength metal with higher strength than pure aluminum, a fastening nut N, and a heat conductive member 14. The fastening busbars 70 are arranged on the lower surface of the main body 41 of the relay 40, as shown in Figure 21.

[0128] The second connecting portion 72 of the fastening busbar 70 has a through hole through which a bolt B9 is inserted. The bolt B9 has a bolt head BX9. More specifically, the bolt head BX9 has a connection portion JP103A with the second connecting portion 72 and a connection portion JP103B with the third connecting portion 181 in the vertical direction (an example of the first direction in this disclosure).

[0129] The connection portion JP103A between the bolt head BX9 and the second connection portion 72, and the connection portion JP103B between the bolt head BX9 and the third connection portion 181, may be surface-treated with plating or other methods to make them electrically conductive, and may be connected by mechanical riveting, welding or other dissimilar material connection methods. That is, at connection portion JP103A, at least one surface of the second connection portion 72 of the fastening busbar 70 and the bolt head BX9 of the fastening bolt B9 is treated with a conductive surface treatment. At connection portion JP103B, at least one surface of the third connection portion 181 of the first conductive busbar 180 and the bolt head BX9 of the fastening bolt B9 is treated with a conductive surface treatment. Examples of surface treatments include plating, anodizing, thermal spraying, and painting. Examples of plating include nickel plating and tin plating. In this embodiment, a case is shown where a part of the bolt B9 is surface-treated to be electrically conductive, but the entire circumference of the surface of the bolt B9 may be surface-treated. The space SP11 between bolt B9 and the second connecting portion 72 is the space through which the threads pass when bolt B9 is inserted.

[0130] The second connection portion 72 and the third connection portion 181 face each other in the first direction. With the bolt B9 inserted through the bolt insertion hole in the second connection portion 72, the nut N is fastened to the bolt B9, thereby electrically connecting the second connection portion 72 and the third connection portion 181 via the bolt B9, and also thermally connecting them. Heat from the relay 40 is transmitted to the lower case 11 via the terminal 42, the first connection portion 71, the main body 73, the second connection portion 72, the bolt head BX9 of the bolt B9, the third connection portion 181, and the heat conductive member 14. In other words, the connection point between the fastening busbar 70 and the first conductive busbar 180 forms a conductive path, and good conductivity can be ensured by releasing excess heat to the lower case 11. Heat is dissipated at the third connection portion 181, reducing the amount of heat transmitted from the first conductive busbar 180 to the second electronic component 5.

[0131] The heat from the relay 40 is transferred to the lower case 11 via the terminal 42, the first connection part 71, the main body 73, the second connection part 72, the bolt head BX9 of bolt B9, and the third connection part 81. In other words, heat is dissipated at the third connection part 81, reducing the amount of heat transferred from the first conductive busbar 80 to the second electronic component 5. A heat transfer material such as a heat dissipation sheet or heat dissipation grease may be interposed between the third connection part 81 and the lower case 11.

[0132] <Modification 1-5> Modification 1-5 of the present disclosure will be described with reference to Figure 22. The electrical junction box JB according to Modification 1-5 is configured substantially the same as embodiments 1-1, 1-2 and modification 1-4, except for the busbar routing structure of embodiment 1-1. Therefore, explanations of the same components and effects as embodiments 1-1, 1-2 and modification 1-4 may be omitted.

[0133] (Busbar Routing Structure 104) The busbar routing structure 104 of this embodiment comprises a relay 40, a pair of fastening busbars 170, a terminal 42, a bolt B7, a first conductive busbar 180, a second conductive busbar 190, a fastening nut N1 made of a high-strength metal with higher strength than pure aluminum, a bolt B9, and a heat conductive member 14. The heat conductive member 14 is arranged between the third connection part 181 and the lower case 11. The fastening busbars 170 are arranged on the lower surface of the main body 41 of the relay 40, as shown in Figure 22.

[0134] The fastening busbar 170 comprises a first connection portion 171 connected to the relay 40, a second connection portion 172 connected to the conductive busbars 180 and 190, and a fastening busbar body 173 (hereinafter referred to as "body 173") connecting the first connection portion 171 and the second connection portion 172.

[0135] The first connecting portion 171 of the fastening busbar 170 has a through hole through which a bolt B7 is inserted. The second connecting portion 172 of the fastening busbar 170 has a through hole through which a bolt B9 is inserted. The bolt B9 has a bolt head BX9. The nut N1 is conductive. For example, the nut N1 may be made of a copper alloy or an aluminum alloy, or it may be surface-treated on all or part of its surface to allow conductivity. In the vertical direction (an example of the first direction of this disclosure), the nut N1 has a connection portion JP104A above the nut N1 for connection with the second connecting portion 172, and a connection portion JP104B below the nut N1 for connection with the third connecting portion 181.

[0136] The connection portion JP104A between the nut N1 and the second connecting portion 72, and the connection portion JP104B between the nut N1 and the third connecting portion 181, may be surface-treated to be electrically conductive, or they may be connected by mechanical crimping, welding, or other dissimilar material connection methods. That is, at connection portion JP104A, at least one surface of the second connecting portion 172 of the fastening busbar 170 and the fastening nut N1 is surface-treated to be electrically conductive. At connection portion JP104B, at least one surface of the third connecting portion 181 of the first conductive busbar 180 and the fastening nut N1 is surface-treated to be electrically conductive. Examples of surface treatments include plating, anodizing, thermal spraying, and painting. Examples of plating include nickel plating and tin plating. In this embodiment, a case is shown where a part of the fastening nut N1 is surface-treated to be electrically conductive, but the entire circumference of the surface of the fastening nut N1 may be surface-treated. The space SP12 between bolt B9 and the second connecting portion 72 is the space through which the threads pass when bolt B9 is inserted.

[0137] The second connection portion 172 and the third connection portion 181 face each other in the first direction. By interposing a nut N1 between the second connection portion 172 and the third connection portion 181 and fastening a bolt B9 to the nut N1, the second connection portion 172 and the third connection portion 181 are electrically connected via the nut N1 and are also thermally connected. Heat from the relay 40 is transmitted to the lower case 11 via the terminal 42, the first connection portion 171, the main body 173, the second connection portion 172, the nut N1, the third connection portion 181, and the heat conductive member 14. In other words, the connection point between the fastening busbar 170 and the first conductive busbar 180 forms a conductive path, and good conductivity can be ensured by releasing excess heat to the lower case 11. Heat is dissipated at the third connection portion 181, reducing the amount of heat transmitted from the first conductive busbar 180 to the second electronic component 5.

[0138] (Other embodiments) The thickness of the fastening busbar and the conductive busbar may be different. For example, the fastening busbar may be thicker than the conductive busbar.

[0139] In the above embodiment, a relay was given as an example of a heat-generating component that generates heat when energized, but other components may be used as long as they have the property of generating heat when energized. Heat-generating components may be, for example, fuses, resistors, coils, capacitors, diodes, ICs (Integrated Circuits), or switching elements such as FETs (Field Effect Transistors).

[0140] In the above embodiment, the number of electronic components, the first electronic component 4 and the second electronic component 5, is set to two components, but the number of these electronic components may be increased or decreased.

[0141] In the above embodiment, a bolt B9 is shown as an example of a second fastening member fastened by screwing it onto nuts N, N1, and N2. However, in this case, the bolt B9 may be fastened to nuts N, N1, and N2 in an inverted manner.

[0142] In the above embodiment, bolts B7 and B8 were given as examples of first fastening members, but the first fastening members are not limited to these.

[0143] The shapes of the square collar S and fastening washer M shown in the above embodiment may be other shapes, sizes, and arrangements as long as electrical conductivity is maintained.

[0144] JB, JB2: Electrical junction box 2, 3: External connection busbar 4: First electronic component 5: Second electronic component 6: Inter-electronic component busbar 10: Case (example of heat dissipation section) 11: Lower case (example of heat dissipation section) 12, 13: Upper case (example of heat dissipation section) 12A: Housing section 12B: First window section 12C: Second window section 14: Heat conductive member (example of heat dissipation section) 20: Main body section 21: Second main body section 22: Terminal section 30: Main body section 31: Second main body section 32: Terminal section 40: Relay 41: Main body section 42: Terminal 43: Partition wall 44: Seat surface 45: Recess 50: First busbar 51: First electronic component side connection section 52: Main body section 53: External connection section 60: First electronic component side terminal 61: Second electronic component side terminal 62: Main body 70, 170, 270: Fastening busbars 71, 171, 271: First connection part 72, 172, 272: Second connection part 73, 173: Fastening busbar body 80, 180: First conductive busbar 81, 181: Third connection part 82: First conductive busbar body 83: Fourth connection part 90, 190: Second conductive busbar 91: Third connection part 92: Second conductive busbar body 93: External connection part 100, 101, 102, 103, 104: Busbar routing structure 200, 201, 202, 203, 204, 205: Busbar routing structure BI1, BI6: Bolt insertion hole B2, B3, B4, B5, B7, B8, B9, B10: Bolt BX9: Bolt head S: Square collar M: Fastening washer JP100, JP101, JP102, JP103A, JP103B, JP104A, JP104B, JP200, JP201, JP202, JP203, JP205: Connection part JP204: Surface treatment N, N1, N2: Nut SP1, SP2, SP3, SP4, SP5, SP6, SP7, SP8, SP9, SP10, SP11, SP12: Space

Claims

A heat-generating component that generates heat when power is applied, First fastening member and A fastening busbar, which is electrically connected to the heat-generating component by being fastened by the first fastening member, The fastening busbar is electrically connected to a conductive busbar, The fastening busbar comprises a first connection portion connected to the heat-generating component, a second connection portion connected to the conductive busbar, and a fastening busbar body connecting the first connection portion and the second connection portion. The busbar routing structure comprises a conductive busbar having a third connecting portion that faces and is connected to the second connecting portion in a first direction, and a conductive busbar body extending from the third connecting portion. 　 The busbar cable arrangement structure according to claim 1, wherein at least one of the second connection portion or the third connection portion is thermally connected to the heat dissipation portion in the first direction. 　 The busbar wiring structure according to claim 2, wherein the heat dissipation portion includes a heat conductive member made of a heat conductive material and a case in which the busbar wiring structure is housed. 　 The busbar routing structure according to claim 1 or claim 2, wherein the second connection portion of the fastening busbar and the third connection portion of the conductive busbar are fastened together by a second fastening member. 　 The busbar routing structure according to claim 1 or claim 2, wherein the fastening busbar is L-shaped, and the second connection portion and the heat-generating component do not overlap in the first direction. 　 The conductive busbar is made of aluminum or an aluminum alloy. The busbar routing structure according to claim 1 or claim 2, wherein at least one surface of the fastening busbar or the conductive busbar is subjected to a conductive surface treatment. 　 The busbar routing structure according to claim 1 or claim 2, further comprising fastening washers made of a high-strength metal having greater strength than pure aluminum, which are electrically and thermally connected to the conductive busbars. 　 The busbar routing structure according to claim 7, wherein at least one surface of the fastening busbar or the fastening washer is subjected to a conductive surface treatment. 　 The busbar routing structure according to claim 7, wherein at least one surface of the conductive busbar or the fastening washer is subjected to a conductive surface treatment. 　 The busbar routing structure according to claim 1 or claim 2, further comprising fastening bolts that are electrically and thermally connected to the conductive busbars and are made of a high-strength metal with higher strength than pure aluminum. 　 The busbar wiring structure according to claim 10, wherein the fastening bolts are connected to the conductive busbar by welding or mechanical riveting. 　 The busbar wiring structure according to claim 10, wherein at least one surface of the fastening busbar or the fastening bolt is subjected to a conductive surface treatment. 　 The busbar routing structure according to claim 10, wherein at least one surface of the conductive busbar or the fastening bolt is subjected to a conductive surface treatment. 　 The busbar routing structure according to claim 1 or claim 2, further comprising fastening nuts made of a high-strength metal having greater strength than pure aluminum, which are electrically and thermally connected to the conductive busbars. 　 The busbar routing structure according to claim 14, wherein the fastening nut is connected to the conductive busbar by welding or mechanical crimping. 　 The busbar routing structure according to claim 14, wherein at least one surface of the fastening busbar or the fastening nut is subjected to a conductive surface treatment. 　 The busbar routing structure according to claim 14, wherein at least one surface of the conductive busbar or the fastening nut is subjected to a conductive surface treatment. 　 The busbar routing structure according to claim 1 or claim 2, further comprising a collar made of a high-strength metal having higher strength than pure aluminum, which is electrically and thermally connected to the conductive busbar. 　 The busbar routing structure according to claim 18, wherein at least one surface of the fastening busbar or the collar is subjected to a conductive surface treatment. 　 The busbar routing structure according to claim 18, wherein at least one surface of the conductive busbar or the collar is subjected to a conductive surface treatment. 　 The busbar routing structure according to claim 1 or claim 2, wherein the fastening busbar is connected to the conductive busbar by welding or mechanical crimping. 　 The busbar routing structure according to claim 1 or claim 2, wherein the fastening busbar is configured such that the first connecting portion and the second connecting portion have different heights in the first direction, and the second connecting portion and the heat-generating component do not overlap in the first direction.

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