Busbar fastening structure and electrical connection box

Abstract

To prevent a busbar from being deformed by the axial force applied during fastening.SOLUTION: A busbar fastening structure according to the present disclosure includes an electronic component having a terminal 33 and generating heat when electricity is passed through it, a fastening member, a fastening busbar 60 that is fastened to the terminal 33 by the fastening member and thereby electrically connected to the electronic component, and a connecting busbar 70 that is electrically connected to portion of the fastening busbar 60 excluding a fastened portion 61 that is fastened by the fastening member, and the fastening busbar 60 has a greater strength than connecting busbar 70.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure relates to a bus bar fastening structure and an electrical connection box.

Background Art

[0002] Conventionally, a fastening structure described in Japanese Unexamined Patent Application Publication No. 2023-82637 (Patent Document 1 below) is known. The fastening structure described in Patent Document 1 includes a first member to be fastened containing pure aluminum or an aluminum alloy, a second member to be fastened containing a metal, and a fastening member for fastening and fixing the first member to be fastened and the second member to be fastened to each other. On the surface of the first member to be fastened facing the second member to be fastened, a protrusion containing pure aluminum or an aluminum alloy and protruding toward the second member to be fastened is integrally formed. The pure aluminum or aluminum alloy in the protrusion of the first member to be fastened is in direct contact with the metal of the second member to be fastened.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] From the viewpoints of conductivity and weight reduction, it is desirable to use pure aluminum as in the above-described fastening structure. However, since the strength of pure aluminum is low, the first member to be fastened (bus bar) may be deformed by the axial force during fastening.

[0005] The present disclosure has been completed based on the above circumstances, and an object thereof is to suppress deformation of the bus bar due to the axial force during fastening.

Means for Solving the Problems

[0006] The bus bar fastening structure of the present disclosure includes an electronic component having a terminal and generating heat upon energization, a fastening member, a fastening bus bar electrically connected to the electronic component by being fastened to the terminal by the fastening member, and a connection bus bar electrically connected to a portion of the fastening bus bar excluding the fastened portion fastened by the fastening member. The fastening bus bar has a higher strength than the connection bus bar, and it is a bus bar fastening structure.

Advantages of the Invention

[0007] According to the present disclosure, it is possible to suppress deformation of the bus bar due to the axial force during fastening.

Brief Description of the Drawings

[0008]

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Modes for Carrying Out the Invention

[0009] [Description of Embodiments of the Present Disclosure] First, the embodiments of the present disclosure will be listed and described. [1] The bus bar fastening structure of the present disclosure includes an electronic component having terminals and generating heat upon energization, a fastening member, a fastening bus bar electrically connected to the electronic component by being fastened to the terminals by the fastening member, and a connection bus bar electrically connected to a portion of the fastening bus bar excluding the fastened portion fastened by the fastening member. The fastening bus bar has higher strength than the connection bus bar.

[0010] By fastening the fastening bus bar to the terminals of the electronic component with the fastening member, the fastening bus bar and the electronic component are electrically connected. Although the fastening bus bar receives an axial force from the fastening member during fastening, since the fastening bus bar has higher strength than the connection bus bar, deformation of the fastening bus bar due to the axial force during fastening can be suppressed.

[0011] Also, since the connection bus bar is electrically connected to a portion of the fastening bus bar excluding the fastened portion fastened by the fastening member, even if the fastening bus bar is slightly deformed, deformation of the connection bus bar can be suppressed thereby. As a result, for example, pure aluminum can be used as the material of the connection bus bar, and the bus bar fastening structure can be lightened.

[0012] [2] In the above [1], it is preferable that the fastening member has a bolt head, and the connection bus bar has a bolt escape hole for escaping the bolt head and a joined portion formed around the bolt escape hole and joined to the fastening bus bar. Since the joined portion is formed around the bolt escape hole, deformation of the joined portion can be suppressed.

[0013] [3] In the above [1] or [2], it is preferable that the fastening bus bar has a heat extraction portion formed in a non - energized region different from the energized region for conducting electricity between the fastening bus bar and the connection bus bar. Since the bus bar for fastening has a heat sink portion formed in a non-energized area, it is possible to gain heat capacity by the heat sink portion without affecting conductivity, and the heat generated in the electronic component can be released to the heat sink portion.

[0014] [4] In any one of the above [1] to [3], it is preferable that the heat sink portion is formed in a folded-back shape. Since the heat sink portion is formed in a folded-back shape, the bus bar fastening structure can be miniaturized compared to the case where the heat sink portion is formed in a straight line.

[0015] [5] In any one of the above [1] to [4], it is preferable to further include a heat sink bus bar that is co-fastened to the fastening bus bar. Heat capacity can be gained by the heat sink bus bar, and the heat generated in the electronic component can be released to the heat sink bus bar.

[0016] [6] In any one of the above [1] to [5], it is preferable that the fastening bus bar is subjected to a surface treatment. For example, by surface treatment such as plating, it is possible to suppress the formation of an oxide film on the surface of the fastening bus bar, and the contact resistance between the fastening bus bar and the connection bus bar can be reduced.

[0017] [7] In any one of the above [1] to [6], it is preferable that at least one of the fastening bus bar or the connection bus bar is thermally connected to a cooling surface. At least one of the fastening bus bar or the connection bus bar can be cooled by the cooling surface.

[0018] [8] In any one of the above [1] to [7], it is preferable that the thermal conductivity and electrical conductivity of the connection bus bar are higher than those of the fastening bus bar. Heat dissipation and conductivity can be ensured by the connection bus bar.

[0019] [9] In any one of the above [1] to [8], it is preferable that the joint portion between the connection bus bar and the fastening bus bar is at least on the side in the conductive path direction when viewed from the fastening direction of the fastening member. Since the joint position is at least on the side in the conductive path direction, good conductivity can be ensured.

[0020]

[10] In any one of the above [1] to [9], it is preferable that the joint position between the connection bus bar and the fastening bus bar is arranged along at least two sides around the fastening member. The joint strength of the connection bus bar to the fastening bus bar can be sufficiently ensured.

[0021]

[11] The electrical connection box of the present disclosure may include the bus bar fastening structure according to any one of the above [1] to

[10] , and another electronic component that is electrically connected to the electronic component via the fastening bus bar and the connection bus bar.

[0022] [Details of the Embodiment of the Present Disclosure] Hereinafter, embodiments of the present disclosure will be described. The present disclosure is not limited to these examples, and is indicated by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims. In each drawing, for convenience of explanation, a part of the configuration may be exaggerated or simplified. Also, the dimensional ratios of each part may be different in each drawing. "Orthogonal" in this specification includes not only the case of strict orthogonality but also the case of generally orthogonal within the range where the actions and effects in the present embodiment are exhibited.

[0023] Also, "opposite" in this specification means that surfaces or members are in a front-to-front position with respect to each other, and includes not only the case where they are completely in a front-to-front position with respect to each other but also the case where they are partially in a front-to-front position with respect to each other. Also, "opposite" in this specification includes both the case where a member different from the two parts is interposed between the two parts and the case where nothing is interposed between the two parts.

[0024] <Embodiment 1> Embodiment 1 of the present disclosure will be described with reference to FIGS. 1 to 4. In the following description, the direction indicated by the arrow Z is the upward direction, the direction indicated by the arrow X is the forward direction, and the direction indicated by the arrow Y is the leftward direction. Note that for a plurality of identical members, only some of the members may be labeled, and the labels of other members may be omitted.

[0025] (Electrical connection box JB) The electrical connection box JB of the present embodiment is mounted on a vehicle such as an electric vehicle or a hybrid vehicle and is arranged in a power supply path from a battery to a load such as a motor. As shown in FIG. 2, the electrical connection box JB is configured to be connected to external busbars 2 and 3. The external busbars 2 and 3 are for electrically connecting a device (including a battery) provided outside the electrical connection box JB and the electrical connection box JB. The external busbars 2 and 3 have portions arranged outside the electrical connection box JB. The external busbar 2 is electrically connected to the battery. The external busbar 3 is electrically connected to the load. The connection between the external busbars 2 and 3 and the electrical connection box JB is performed by bolt fastening. As shown in FIG. 1, the electrical connection box JB includes a case 10, a fuse 20 (an example of another electronic component), a relay 30 (an example of an electronic component), a first busbar 40, and a second busbar 50.

[0026] (Case 10) The case 10 is made of a synthetic resin and includes a lower case 11 and an upper case 12. The upper case 12 is assembled by being overlapped on the lower case 11. When bolts B1 and B3 are fastened from above when connecting the external busbars 2 and 3 and the electrical connection box JB by bolt fastening, as shown in FIGS. 1 to 3, the upper case 12 is arranged above the lower case 11. Hereinafter, assuming that the upper case 12 is arranged above the lower case 11, the configuration and arrangement of each member of the electrical connection box JB will be described.

[0027] (Lower case 11) As shown in FIG. 1, the lower case 11 is formed in a tray shape that is long in the front-rear direction. In the lower case 11, a fuse 20, a relay 30, a first bus bar 40, and a second bus bar 50 are arranged. The fuse 20 is disposed in the front portion of the lower case 11. Bolts B1 and B2 are respectively fastened to the terminal portions 22 formed on both the front and rear sides of the fuse 20. The relay 30 is disposed in the rear portion of the lower case 11. A bolt B3 is fastened to the rear end portion of the second bus bar 50.

[0028] (Upper case 12) As shown in FIG. 1, the upper case 12 is in a lid shape. The upper case 12 includes a first bus bar accommodating portion 12A that accommodates the first bus bar 40 and a second bus bar accommodating portion 12B that accommodates the second bus bar 50. Each of the bus bar accommodating portions 12A and 12B is provided in a groove shape that conforms to the shape of each of the bus bars 40 and 50. A window portion 12C for connecting the terminal portion 22 of the fuse 20 and the external bus bar 2 is provided at the front end portion of the upper case 12.

[0029] (Fuse 20) The fuse 20 includes a main body portion 21 and two terminal portions 22 extending from both the front and rear ends of the main body portion 21. The main body portion 21 is in a block shape. The terminal portion 22 is made of metal. The terminal portion 22 is in a thin plate shape in the vertical direction. The terminal portion 22 is fastened to a fixing nut (not shown) of the lower case 11 by bolts B1 and B2.

[0030] (Relay 30) Relay 30 is a large mechanical relay through which high current from the battery is conducted. As shown in FIGS. 3 and 4, relay 30 includes a main body 31 and a partition wall 32 extending from the right side surface of the main body 31. The main body 31 is in a block shape. Two terminals 33 are formed on the right side surface of the main body 31. The terminals 33 are arranged to protrude slightly to the right from the right side surface of the main body 31. Inside the terminal 33, a bottomed recess 34 that opens to the right and is recessed to the left is formed. A female thread is formed on the inner peripheral surface of the recess 34. A male thread is formed on the outer peripheral surface of the shaft portion B52 of bolts B4 and B5. The male threads of bolts B4 and B5 can enter the recess 34 of the terminal 33 and be screwed into the female thread. Thereby, bolts B4 and B5 are respectively fastened to each terminal 33. The two terminals 33 of relay 30 are arranged with the partition wall 32 therebetween.

[0031] (Bus bar fastening structure) The first bus bar 40 and the second bus bar 50 are members formed by punching and bending a metal plate material having conductivity. The second bus bar 50 includes a relay connection portion 51 connected to the terminal 33 of the relay 30 and an external connection portion 52 connected to the external bus bar 3. The relay connection portion 51 has an insertion hole through which bolt B4 is inserted. The external connection portion 52 has an insertion hole through which bolt B3 is inserted.

[0032] The first bus bar 40 includes a fuse connection portion 41 connected to the terminal portion 22 of the fuse 20, a relay connection portion 42 (an example of a bus bar fastening structure) connected to the terminal 33 of the relay 30, an intermediate portion 43 connecting the fuse connection portion 41 and the relay connection portion 42, and an extension portion 44 extending forward from the intermediate portion 43 more than the fuse connection portion 41. The fuse connection portion 41 has an insertion hole through which bolt B2 is inserted. The relay connection portion 42 has an insertion hole through which bolt B5 (an example of a fastening member) is inserted.

[0033] A bolt B2 is fastened to the fuse connection part 41, and a bolt B5 is fastened to the relay connection part 42. The fuse connection part 41 extends leftward from the front end part of the intermediate part 43. The intermediate part 43 is in a plate shape extending in the front-rear direction. The extension part 44 is arranged by utilizing the space on the right side of the fuse 20 and has a function of releasing the heat transmitted from the fuse 20 and the relay 30 to the first bus bar 40 to the case 10.

[0034] As shown in FIG. 4, the relay connection part 42 includes a fastening bus bar 60 that is electrically connected to the relay 30 by being fastened to the terminal 33 by a bolt B5, and a connection bus bar 70 that is electrically connected to a bus bar joining region 62 excluding a fastened part 61 fastened by the bolt B5 among the fastening bus bar 60. A joining part 45 is formed between the bus bar joining region 62 and the connection bus bar 70. The fastening bus bar 60 has higher strength than the connection bus bar 70.

[0035] The bolt B5 has a bolt head B51. The connection bus bar 70 has a bolt escape hole 71 for escaping the bolt head B51, and a joined part 72 that is formed around the bolt escape hole 71 and joined to the fastening bus bar 60. The joined part 72 is thermally connected to the heat dissipation member H. For example, the heat dissipation member H may be in contact with the surface of the joined part 72 on the side opposite to the fastening bus bar 60. The heat dissipation member H corresponds to the "cooling surface" of the present disclosure and is, for example, the case 10 of the electrical connection box JB or the housing of the battery pack.

[0036] As the fastening bus bar 60, it is preferable to use a strong bus bar (for example, high-strength aluminum such as 6000 series aluminum alloy, copper, etc.). By doing so, it is possible to suppress the deformation of the fastening bus bar 60 due to the axial force when the bolt B5 is fastened. On the other hand, as the connection bus bar 70, it is preferable to use pure aluminum (such as 1000 series aluminum) from the viewpoints of conductivity and weight reduction. The fastening bus bar 60 and the connection bus bar 70 are mechanically and electrically connected. It is preferable that the thermal conductivity and electrical conductivity of the connection bus bar 60 are higher than those of the fastening bus bar 70. By doing so, heat capacity can be accumulated in the vicinity of the relay 30.

[0037] The fastening bus bar 60 may be subjected to a surface treatment for reducing the contact resistance. Examples of the type of surface treatment include plating, anodizing, spraying, painting, etc. Examples of the type of plating include nickel plating, tin plating, etc. By doing so, the material of the fastening bus bar 60 can be selected without problems with the contact resistance.

[0038] Examples of the joining method of the joint portion 45 and the material of the fastening bus bar 60 used for the joining method include the following. 1. Ultrasonic welding: copper material, aluminum material 2. Laser welding: aluminum material (nickel plating may be applied) 3. Electromagnetic pulse: copper material 4. Mechanical caulking: copper material, aluminum material

[0039] According to ultrasonic welding, since dissimilar material joining is possible, copper material can be selected as the material of the fastening bus bar 60, but aluminum material may also be selected. According to laser welding, since dissimilar material joining is impossible, aluminum material is used as the material of the fastening bus bar 60. According to electromagnetic pulse, since dissimilar material joining is possible, copper material can be selected as the material of the fastening bus bar 60, but aluminum material may also be selected. According to mechanical caulking, if it is a caulking method enabling dissimilar material joining, copper material can be selected as the material of the fastening bus bar 60, but aluminum material may also be selected.

[0040] Since the joint portion 45 is formed by joining the joint portion 72 formed around the bolt clearance hole 71 to the fastening bus bar 60, it is possible to gain heat capacity by the fastening bus bar 60 while avoiding the buckling of the fastening of the connection bus bar 70. Further, since a wide joint portion 45 can be secured, the joint strength between the fastening bus bar 60 and the connection bus bar 70 can be increased. Further, since the joint portion 45 is at least on the side in the direction of the conductive path when viewed from the fastening direction, good conductivity can be ensured.

[0041] (Operational effects of Embodiment 1) The relay connection portion 42 according to Embodiment 1 includes a relay 30 having a terminal 33 that generates heat when energized, a bolt B5, a fastening bus bar 60 that is electrically connected to the relay 30 by being fastened to the terminal 33 by the bolt B5, and a connection bus bar 70 that is electrically connected to the bus bar joint region 62 of the fastening bus bar 60 excluding the fastened portion 61 fastened by the bolt B5. The fastening bus bar 60 has a higher strength than the connection bus bar 70. The relay 30 is electrically connected to the fuse 20 via the fastening bus bar 60 and the connection bus bar 70.

[0042] By fastening the fastening bus bar 60 to the terminal 33 of the relay 30 with the bolt B5, the fastening bus bar 60 and the relay 30 are electrically connected. Although the fastening bus bar 60 receives axial force from the bolt B5 during fastening, since the fastening bus bar 60 has a higher strength than the connection bus bar 70, it is possible to suppress deformation of the fastening bus bar 60 due to the axial force during fastening.

[0043] Further, since the connection bus bar 70 is electrically connected to the bus bar joint region 62 of the fastening bus bar 60 excluding the fastened portion 61 fastened by the bolt B5, even if the fastening bus bar 60 is slightly deformed, it is possible to suppress deformation of the connection bus bar 70 thereby. As a result, pure aluminum can be used as the material of the connection bus bar 70, and the relay connection portion 42 and thus the electrical connection box JB can be lightened.

[0044] The bolt B5 has a bolt head B51, and the connection bus bar 70 preferably has a bolt clearance hole 71 for passing the bolt head B51 and a joint portion 72 formed around the bolt clearance hole 71 and joined to the fastening bus bar 60. Since the joint portion 72 is formed around the bolt clearance hole 71, deformation of the joint portion 72 can be suppressed.

[0045] The fastening bus bar 60 is preferably subjected to a surface treatment. For example, by a surface treatment such as plating, formation of an oxide film on the surface of the fastening bus bar 60 can be suppressed, and the contact resistance between the fastening bus bar 60 and the connection bus bar 70 can be reduced.

[0046] <Embodiment 2> Embodiment 2 of the present disclosure will be described with reference to FIGS. 5 and 6. Since the electrical connection box JB2 according to Embodiment 2 is configured substantially the same as Embodiment 1 except for the configuration of the bus bar fastening structure (relay connection portions 42, 51) of Embodiment 1, descriptions of the same members, operations, and effects as those in Embodiment 1 may be omitted.

[0047] The electrical connection box JB2 includes relay connection portions 422, 512. The relay connection portions 422, 512 include a fastening bus bar 602 and a connection bus bar 70. A joint portion 45 is formed between the bus bar joint region 62 of the fastening bus bar 602 and the connection bus bar 70. The fastening bus bar 602 has a higher strength than the connection bus bar 70.

[0048] The fastening bus bar 602 has a heat extraction portion H2 formed in a non - energized region R2 different from the energized region R1. The heat extraction portion H2 extends upward from the bus bar joint region 62. The energized region R1 mainly corresponds to the region where the joint portion 45 is formed and the region extending rightward (in the direction of the conductive path) from this region. The non - energized region R2 corresponds to the region extending upward (in a direction different from the direction of the conductive path) from the region where the joint portion 45 is formed.

[0049] According to the present embodiment, the heat capacity can be increased by the heat dissipation portion H2 of the fastening bus bar 602. In particular, since the heat dissipation portion H2 is formed in the non-energized region R2, the heat capacity can be increased by the heat dissipation portion H2 without affecting the conductivity, and the heat generated in the relay 30 can be dissipated to the heat dissipation portion H2. Further, when viewed from the fastening direction, since the joint portion 45 is at least on the side in the conductive path direction, good conductivity can be ensured.

[0050] <Embodiment 3> Embodiment 3 of the present disclosure will be described with reference to FIGS. 7 and 8. The electrical connection box JB3 according to Embodiment 3 is configured substantially the same as Embodiment 1 except for the configuration of the bus bar fastening structure (relay connection portions 42, 51) of Embodiment 1. Therefore, the description of the same members, functions, and effects as those in Embodiment 1 may be omitted.

[0051] The electrical connection box JB3 includes relay connection portions 423, 513. The relay connection portions 423, 513 include a fastening bus bar 60, a connection bus bar 703, and a heat dissipation bus bar 80. A joint portion 453 is formed between the bus bar joint region 62 of the fastening bus bar 60 and the connection bus bar 703. The fastening bus bar 60 has higher strength than the connection bus bar 703. As the material of the heat dissipation bus bar 80, an inexpensive material (for example, iron, copper, strong aluminum, etc.) can be selected.

[0052] The connection bus bar 703 is formed shorter in the left-right direction than the connection bus bar 70 of Embodiment 1. The edge of the connection bus bar 703 is offset in the left-right direction so as not to overlap with the bolt B53. In the present embodiment, a bolt escape hole for escaping the bolt head of the bolt is not formed in the connection bus bar 703, and the heat dissipation bus bar 80 is fastened together with the fastening bus bar 60. By doing so, the heat capacity can be increased by the heat dissipation bus bar 80, and the heat generated in the relay 30 can be dissipated to the heat dissipation bus bar 80. Further, when viewed from the fastening direction, since the joint portion 453 is at least on the side in the conductive path direction, good conductivity can be ensured.

[0053] <Embodiment 4> Embodiment 4 of the present disclosure will be described with reference to FIGS. 9 and 10. Since the electrical connection box JB4 according to Embodiment 4 is configured substantially the same as Embodiment 1 except for the configuration of the bus bar fastening structure (relay connection portions 42, 51) of Embodiment 1, the description of the same members, functions, and effects as those of Embodiment 1 may be omitted.

[0054] The electrical connection box JB4 includes relay connection portions 424, 514. The relay connection portions 424, 514 include a fastening bus bar 604 and a connection bus bar 70. A joint portion 45 is formed between the bus bar joint region 62 of the fastening bus bar 604 and the connection bus bar 70. The fastening bus bar 604 has higher strength than the connection bus bar 70.

[0055] The fastening bus bar 604 has a heat extraction portion H4 formed in a non - energized region R4 different from the energized region R1. The heat extraction portion H4 extends upward from the bus bar joint region 62. The energized region R1 mainly corresponds to the region where the joint portion 45 is formed and the region extending rightward (in the direction of the conductive path) from this region. The non - energized region R4 corresponds to the region that extends upward (in a direction different from the direction of the conductive path) from the region where the joint portion 45 is formed and is folded back downward.

[0056] According to this embodiment, the heat capacity can be increased by the heat extraction portion H4 of the fastening bus bar 604. In particular, since the heat extraction portion H4 extends upward and then is folded back downward, the electrical connection box JB4 can be miniaturized in the vertical direction compared to the case where the heat extraction portion is formed linearly. The heat capacity can be increased by the heat extraction portion H4, and the heat generated by the relay 30 can be released to the heat extraction portion H4. Also, when viewed from the fastening direction, since the joint portion 45 is at least on the side in the direction of the conductive path, good conductivity can be ensured.

[0057] <Examples 1 to 9> Examples 1 to 9 of the present disclosure will be described with reference to FIGS. 11 to 19. Since the electrical connection box JB according to Examples 1 to 9 is configured substantially the same as that of Embodiment 1 except that the joining method of Embodiment 1 is more specific, the description of the same members, functions, and effects as those of Embodiment 1 may be omitted.

[0058] In Example 1 shown in FIG. 11, the connection bus bar 70 is joined to the fastening bus bar 60 by laser welding. The laser welding is performed annularly so as to surround the periphery of the fastening portions of the bolts B4 and B5. The laser welding may be performed a plurality of times, for example, in a manner in which welding lines having a rectangular shape and a gate shape do not overlap each other. The joining position is indicated by reference sign JP1.

[0059] In Example 2 shown in FIG. 12, the connection bus bar 70 is joined to the fastening bus bar 60 by laser welding. The laser welding is performed on both the upper and lower sides of the fastening portions of the bolts B4 and B5. The laser welding may be performed, for example, in a linear form in which the welding line extends in the left - right direction and in a form in which a plurality of them are arranged in the up - down direction. The joining position is indicated by reference sign JP2.

[0060] In Example 3 shown in FIG. 13, the connection bus bar 70 is joined to the fastening bus bar 60 by laser welding. The laser welding is performed in an L - shape on the lower side and the right side of the fastening portion of the bolt B4, and linearly on the lower side of the fastening portion of the bolt B5. The laser welding may be performed, for example, along two sides, i.e., the upper side and the right side of the fastening bus bar 60, so as to increase the joining area. Also, the laser welding may be performed, for example, in a linear form in which the welding line extends in the left - right direction between the lower side of the fastening bus bar 60 and the bolt B5 and in a state in which a plurality of them are arranged in the up - down direction so as to increase the joining area. The joining position is indicated by reference sign JP3. According to Example 3, since the joining position JP3 is arranged along at least two sides around the bolt B4, the joining strength of the connection bus bar 70 to the fastening bus bar 60 can be sufficiently ensured.

[0061] In Example 4 shown in FIG. 14, the connection bus bar 70 is joined to the fastening bus bar 60 by laser welding. The laser welding is performed on both the upper and lower sides of the fastening portions of bolts B4 and B5. The laser welding may be performed, for example, with the welding lines in an annular shape and arranged in a plurality in the left - right direction. The joining position is indicated by reference sign JP4.

[0062] In Example 5 shown in FIG. 15, the connection bus bar 70 is joined to the fastening bus bar 60 by laser welding. The laser welding is performed in an L - shape on the lower side and the right side of the fastening portion of bolt B4, and linearly on the lower side of the fastening portion of bolt B5. The laser welding may be performed, for example, in an annular shape and along two sides, namely the upper side and the right side of the fastening bus bar 60, to increase the joining area. Also, the laser welding may be performed, for example, with the welding lines in an annular shape and arranged in a plurality in the left - right and up - down directions between the lower side of the fastening bus bar 60 and bolt B5 to increase the joining area. The joining position is indicated by reference sign JP5. According to Example 5, since the joining position JP5 is arranged along at least two sides around bolt B4, sufficient joining strength of the connection bus bar 70 to the fastening bus bar 60 can be ensured.

[0063] In Example 6 shown in FIG. 16, the connection bus bar 70 is joined to the fastening bus bar 60 by ultrasonic welding. The ultrasonic welding is performed on both the upper and lower sides of the fastening portions of bolts B4 and B5. The ultrasonic welding may be performed, for example, with the welded portion in a rectangular shape that is long in the left - right direction. The joining position is indicated by reference sign JP6.

[0064] In Example 7 shown in FIG. 17, the connection bus bar 70 is joined to the fastening bus bar 60 by ultrasonic welding. The ultrasonic welding is performed in an L shape on the lower side and the right side of the fastening part of bolt B4, and is performed on the lower side of the fastening part of bolt B5. The ultrasonic welding may be performed, for example, along two sides of the upper side and the right side of the fastening bus bar 60 to increase the joint area. Further, the ultrasonic welding may be performed, for example, in a rectangular shape that is long in the left-right direction between the lower side of the fastening bus bar 60 and bolt B5 to increase the joint area. The joint position is indicated by reference sign JP7. According to Example 7, since the joint position JP7 is arranged along at least two sides around bolt B4, sufficient joint strength of the connection bus bar 70 to the fastening bus bar 60 can be ensured.

[0065] In Example 8 shown in FIG. 18, the connection bus bar 70 is joined to the fastening bus bar 60 by mechanical caulking. The mechanical caulking is performed at two corners sandwiching the fastening parts of bolts B4 and B5. The mechanical caulking may be performed, for example, in a rectangular shape that is long in the left-right direction at the upper right and lower left corners of the fastening bus bar 60 where the crimping part is located. Further, the mechanical caulking may be performed in a rectangular shape that is long in the left-right direction at the upper left and lower right corners of the fastening bus bar 60 where the crimping part is located. The joint position is indicated by reference sign JP8.

[0066] In Example 9 shown in FIG. 19, the connection bus bar 70 is joined to the fastening bus bar 60 by mechanical caulking. The mechanical caulking is performed on the lower side of the fastening parts of bolts B4 and B5. The mechanical caulking may be performed, for example, in a substantially square shape at the lower right and lower left corners of the fastening bus bar 60 where the crimping part is located. Further, the mechanical caulking may be performed in a rectangular shape that is long in the left-right direction between the lower side of the fastening bus bar 60 and bolt B5 to increase the joint area at one point. The joint position is indicated by reference sign JP9.

[0067] <Embodiment 5> Embodiment 5 of the present disclosure will be described with reference to FIGS. 20 to 22. Since the electrical connection box JB5 according to Embodiment 5 is configured substantially the same as Embodiment 1 except for the configuration of the lower case 11 and the fastening structure of the first bus bar 40, the description of the same members, functions, and effects as those in Embodiment 1 may be omitted.

[0068] (Electrical connection box JB5) The electrical connection box JB5 of the present embodiment includes a case 105, a fuse 20 (an example of an electronic component), a relay 30 (an example of another electronic component), a first bus bar 405, and a second bus bar 50.

[0069] (Case 105) The case 105 is made of synthetic resin and includes a lower case 115 and an upper case 12. The upper case 12 is assembled by being overlapped with the lower case 115. When bolts B1 and B3 are fastened from above when connecting the external bus bars 2 and 3 and the electrical connection box JB5 by bolt fastening, the upper case 12 is arranged above the lower case 115. Hereinafter, assuming that the upper case 12 is arranged above the lower case 115, the configuration and arrangement of the electrical connection box JB5 will be described.

[0070] (Lower case 115) As shown in FIGS. 20 and 21, the lower case 115 is formed in a tray shape that is long in the front-rear direction. The fuse 20, the relay 30, the first bus bar 405, and the second bus bar 50 are arranged in the lower case 115. As shown in FIG. 21, in the front portion of the lower case 115, a fuse arrangement portion 115A for arranging the fuse 20 is formed to open upward. The fuse arrangement portion 115A is a bottomed recess capable of accommodating the main body portion 21 of the fuse 20.

[0071] As shown in FIGS. 21 and 22, fastening portions N1 and N2 to which bolts B1 and B2 can be respectively fastened are provided on both the front and rear sides of the fuse arrangement portion 115A. As shown in FIG. 21, both the front and rear sides of the fuse arrangement portion 115A are terminal blocks 11B to which fastening portions N1 and N2 such as nuts are fixed. The terminal portions 22 (an example of the terminals of electronic components) of the fuse 20 are fastened to the fastening portions N1 and N2. A heat radiating member HM is placed on the front fastening portion N1 of the present embodiment, and the terminal portion 22 is connected to the fastening portion N1 via the heat radiating member HM, but the heat radiating member HM may not be provided.

[0072] As shown in FIG. 21, on the rear side portion of the lower case 115, a mounting surface 11C on which the relay 30 is mounted and a positioning portion 11D for positioning the relay 30 are formed. The positioning portion 11D is a recess that is recessed from a side wall portion 11E that rises upward from the right end edge of the mounting surface 11C. By engaging the partition wall 32 with the positioning portion 11D of the lower case 115, the relay 30 is positioned with respect to the lower case 115. A fastening portion N3 to which the bolt B3 can be fastened is fixed to the rear end portion of the lower case 115. In addition, a fixing portion (not shown) for fixing the relay 30 may be further provided on the mounting surface 11C of the lower case 115.

[0073] (Fastening Structure of the First Bus Bar 405) The first bus bar 405 is a member formed by punching and bending a metal plate material having conductivity. The first bus bar 405 includes an intermediate portion 435 extending in the front-rear direction, a relay connection portion 42 formed at the rear end portion of the intermediate portion 435, and a fuse connection portion 415 formed at the front end portion of the intermediate portion 435.

[0074] The relay connection portion 42 of the first bus bar 405 has an insertion hole 42A through which the bolt B5 is inserted, and the relay connection portion 51 of the second bus bar 50 has an insertion hole 51A through which the bolt B4 is inserted. The bolts B4 and B5 are inserted into the insertion holes 42A and 51A and fastened to the terminal 33 of the relay 30, whereby the first bus bar 405 and the second bus bar 50 are electrically connected via the relay 30.

[0075] The fuse connection part 415 is connected to the front-end lower edge of the intermediate part 435. As shown in FIG. 22, the fuse connection part 415 includes a fuse 20, fastening members (bolt B2, fastening part N2), a fastening bus bar 605, and a connection bus bar 705. As shown in FIG. 21, the connection bus bar 705 includes a first horizontal part 705A extending leftward from the front-end lower edge of the intermediate part 435, a first vertical part 705B extending downward from the left edge of the first horizontal part 705A, a second horizontal part 705C extending leftward from the lower edge of the first vertical part 705B, a second vertical part 705D extending upward from the rear edge of the second horizontal part 705C, and a third horizontal part 705E extending rearward from the upper edge of the second vertical part 705D. The fuse connection part 415 corresponds to the "bus bar fastening structure" of the present disclosure.

[0076] The second horizontal part 705C is arranged corresponding to the fuse arrangement part 115A, and the third horizontal part 705E of the connection bus bar 705 and the fastening bus bar 605 are arranged corresponding to the rear terminal block 11B. As shown in FIG. 22, the second horizontal part 705C is in contact with the bottom surface of the fuse arrangement part 115A. The second horizontal part 705C is thermally connected to the heat sink member H through the bottom surface of the fuse arrangement part 115A. A heat conductive sheet may be interposed between the second horizontal part 705C and the bottom surface of the fuse arrangement part 115A to enhance thermal conductivity. The bottom surface of the fuse arrangement part 115A and the heat sink member H correspond to the "cooling surface" of the present disclosure. On the other hand, the third horizontal part 705E of the connection bus bar 705 is not in contact with the terminal block 11B, and a predetermined clearance is formed between the third horizontal part 705E of the connection bus bar 705 and the terminal block 11B.

[0077] The third horizontal portion 705E of the connection bus bar 705 has a bolt relief hole 715 for passing the bolt B2 and the fastening portion N2, and a joint portion 725 formed around the bolt relief hole 715. A fastening bus bar 605 is joined to the joint portion 725. Among the fastening bus bar 605, the region excluding the fastened portion 615 fastened by the bolt B2 is defined as a bus bar joint region 625. The connection bus bar 705 is electrically connected to the bus bar joint region 625 by joining. A joint portion 455 is formed between the bus bar joint region 625 and the joint portion 725 of the connection bus bar 705. The joining method of the joint portion 455 is the same as that of the joint portion 45 in the first embodiment. The fastening bus bar 605 has a higher strength than the connection bus bar 705.

[0078] The fastened portion 615 of the fastening bus bar 605 and the terminal portion 22 of the fuse 20 are electrically connected by being fastened by the bolt B2 and the fastening portion N2. Therefore, the terminal portion 22 of the fuse 20 is electrically connected to the connection bus bar 705 via the fastening bus bar 605. On the other hand, the external connection bus bar 2 and the terminal portion 22 of the fuse 20 are electrically connected by being fastened by the bolt B1 and the fastening portion N1.

[0079] (Operation and effect of the fifth embodiment) The fuse connection portion 415 according to the fifth embodiment has a terminal portion 22, a fuse 20 that generates heat when energized, fastening members (bolts B1, B2 and fastening portions N1, N2), and a fastening bus bar 605 that is electrically connected to the fuse 20 by being fastened to the terminal portion 22 by the fastening members. The connection bus bar 705 is electrically connected to a location of the fastening bus bar 605 excluding the fastened portion 615 fastened by the fastening members. The fastening bus bar 605 has a higher strength than the connection bus bar 705. The fuse 20 is electrically connected to the relay 30 via the fastening bus bar 605 and the connection bus bar 705.

[0080] By fastening the fastening bus bar 605 to the terminal portion 22 of the fuse 20 with a fastening member, the fastening bus bar 605 and the fuse 20 are electrically connected. Although the fastening bus bar 605 receives an axial force from the fastening member during fastening, since the fastening bus bar 605 has a higher strength than the connection bus bar 705, it is possible to suppress deformation of the fastening bus bar 605 due to the axial force during fastening.

[0081] Also, since the connection bus bar 705 is electrically connected to a portion of the fastening bus bar 605 excluding the fastened portion 615 fastened by the fastening member, even if the fastening bus bar 605 is slightly deformed, it is possible to suppress deformation of the connection bus bar 705 thereby. As a result, for example, pure aluminum can be used as the material of the connection bus bar 705, and the fuse connection portion 415 and thus the electrical connection box JB5 can be lightened.

[0082] Further, according to the present embodiment, even when there is no space between the fastening member and the fuse 20 and heat dissipation can be achieved by utilizing the space below the fuse 20, the connection bus bar 705 can be brought into contact with the heat sink member H. In FIG. 22, the main body portion 21 of the fuse 20 is in contact with the second horizontal portion 705C, but the main body portion 21 may be separated from the second horizontal portion 705C. In that case, the heat generated by the fuse 20 is dissipated to the heat sink member H through the terminal portion 22, the fastening bus bar 605, the third horizontal portion 705E, the second vertical portion 705D, the second horizontal portion 705C, and the bottom surface of the fuse arrangement portion 115A.

[0083] <Examples 10 to 14> Examples 10 to 14 of the present disclosure will be described with reference to FIGS. 23 to 27. The electrical connection box JB5 according to Examples 10 to 14 is obtained by partially modifying the fastening structure of Embodiment 5 and is configured substantially the same as Embodiment 5. Therefore, descriptions of the same members, actions, and effects as those of Embodiment 5 may be omitted.

[0084] In Embodiment 10 shown in FIG. 23, a fastening bus bar 160 is disclosed as a configuration corresponding to the fastening bus bar 605 of Embodiment 5, a connection bus bar 170 is disclosed as a configuration corresponding to the connection bus bar 705 of Embodiment 5, and a fuse connection portion 141 is disclosed as a configuration corresponding to the fuse connection portion 415 of Embodiment 5. The fuse connection portion 141 includes a fuse 20, fastening members (bolt B2, fastening portion N2), a fastening bus bar 160, and a connection bus bar 170.

[0085] The fastening bus bar 160 includes a fastened portion 161 to which the terminal portion 22 of the fuse 20 is connected, a vertical portion 160B extending downward from the front edge of the fastened portion 161, a horizontal portion 160A extending forward from the lower edge of the vertical portion 160B, and a bus bar joining region 162 extending rearward from the rear of the fastened portion 161. The bus bar joining region 162 is located behind the rear end of the terminal portion 22. The region of the fastening bus bar 160 excluding the fastened portion 161 fastened by the bolt B2 is defined as the bus bar joining region 162. The connection bus bar 170 has a joined portion 172.

[0086] The horizontal portion 160A is in contact with the bottom surface of the fuse arrangement portion 115A. In FIG. 23, the main body portion 21 of the fuse 20 is in contact with the horizontal portion 160A, but the main body portion 21 may be spaced apart from the horizontal portion 160A. In that case, the heat generated by the fuse 20 is dissipated to the heat dissipation member H through the terminal portion 22, the fastened portion 161, the vertical portion 160B, the horizontal portion 160A, and the bottom surface of the fuse arrangement portion 115A. The bottom surface of the fuse arrangement portion 115A and the heat dissipation member H correspond to the "cooling surface" of the present disclosure. On the other hand, the bus bar joining region 162 of the fastening bus bar 160 is not in contact with the terminal block 11B, and a predetermined clearance is formed between the bus bar joining region 162 of the fastening bus bar 160 and the terminal block 11B.

[0087] The joint portion 172 of the connection bus bar 170 is electrically connected to the bus bar joint area 162 by joining. A joint portion 145 is formed between the bus bar joint area 162 and the joint portion 172 of the connection bus bar 170. The joining method of the joint portion 145 is the same as that of the joint portion 45 in the first embodiment. The fastening bus bar 160 has a higher strength than the connection bus bar 170.

[0088] The fastened portion 161 of the fastening bus bar 160 and the terminal portion 22 of the fuse 20 are electrically connected by being fastened by the bolt B2 and the fastening portion N2. Therefore, the terminal portion 22 of the fuse 20 is electrically connected to the connection bus bar 170 via the fastening bus bar 160. According to this embodiment, heat can be dissipated without passing through the joint portion 145.

[0089] In the eleventh embodiment shown in FIG. 24, a fastening bus bar 260 is disclosed as a configuration corresponding to the fastening bus bar 605 in the fifth embodiment, a connection bus bar 270 is disclosed as a configuration corresponding to the connection bus bar 705 in the fifth embodiment, and a fuse connection portion 241 is disclosed as a configuration corresponding to the fuse connection portion 415 in the fifth embodiment. The fuse connection portion 241 includes the fuse 20, fastening members (bolt B2, fastening portion N2), the fastening bus bar 260, and the connection bus bar 270.

[0090] The fastening bus bar 260 includes a fastened portion 261 to which the terminal portion 22 of the fuse 20 is connected, a bus bar joint area 262 extended rearward from the fastened portion 261, a vertical portion 260B extending downward from the rear edge of the bus bar joint area 262, and a horizontal portion 260A extending forward from the lower edge of the vertical portion 260B. The bus bar joint area 262 is located rearward of the rear end of the terminal portion 22. The area of the fastening bus bar 260 excluding the fastened portion 261 fastened by the bolt B2 is defined as the bus bar joint area 262. The connection bus bar 270 has a joint portion 272.

[0091] The horizontal portion 260A is in contact with the bottom surface of the fuse arrangement portion 115A. The heat generated by the fuse 20 is dissipated to the heat dissipation member H through the terminal portion 22, the fastened portion 261, the bus bar joining region 262, the vertical portion 260B, the horizontal portion 260A, and the bottom surface of the fuse arrangement portion 115A. The contact area between the horizontal portion 260A and the bottom surface of the fuse arrangement portion 115A is larger than the contact area between the horizontal portion 160A and the bottom surface of the fuse arrangement portion 115A in the tenth embodiment. Therefore, the heat dissipation effect of the eleventh embodiment is larger than the heat dissipation effect of the tenth embodiment.

[0092] The joined portion 272 of the connection bus bar 270 is electrically connected to the bus bar joining region 262 by joining. A joining portion 245 is formed between the bus bar joining region 262 and the joined portion 272 of the connection bus bar 270. The joining method of the joining portion 245 is the same as that of the joining portion 45 in the first embodiment. The fastening bus bar 260 has higher strength than the connection bus bar 270.

[0093] The fastened portion 261 of the fastening bus bar 260 and the terminal portion 22 of the fuse 20 are electrically connected by being fastened by the bolt B2 and the fastening portion N2. Therefore, the terminal portion 22 of the fuse 20 is electrically connected to the connection bus bar 270 via the fastening bus bar 260.

[0094] In the twelfth embodiment shown in FIG. 25, a fastening bus bar 360 is disclosed as a configuration corresponding to the fastening bus bar 605 in the fifth embodiment, a connection bus bar 370 is disclosed as a configuration corresponding to the connection bus bar 705 in the fifth embodiment, and a fuse connection portion 341 is disclosed as a configuration corresponding to the fuse connection portion 415 in the fifth embodiment. The fuse connection portion 341 includes the fuse 20, a fastening member (bolt B2, fastening portion N2), a fastening bus bar 360, and a connection bus bar 370.

[0095] The fastening bus bar 360 includes a fastened portion 361 to which the terminal portion 22 of the fuse 20 is connected, and a bus bar joining region 362 extending downward from the front edge of the fastened portion 361. Among the fastening bus bar 360, the region excluding the fastened portion 361 fastened by the bolt B2 is defined as the bus bar joining region 362. The connection bus bar 370 includes a joined portion 372 connected to the bus bar joining region 362 of the fastening bus bar 360, and a horizontal portion 370A extending forward from the lower edge of the joined portion 372.

[0096] The horizontal portion 370A of the connection bus bar 370 is in contact with the bottom surface of the fuse arrangement portion 115A. The heat generated by the fuse 20 is dissipated to the heat dissipation member H through the terminal portion 22, the fastened portion 361, the bus bar joining region 362, the joined portion 372, the horizontal portion 370A, and the bottom surface of the fuse arrangement portion 115A. On the other hand, the fastened portion 361 of the fastening bus bar 360 is not in contact with the terminal portion 11B, and a predetermined clearance is formed between the fastened portion 361 of the fastening bus bar 360 and the terminal portion 11B.

[0097] The joined portion 372 of the connection bus bar 370 is electrically connected to the bus bar joining region 362 by joining. A joint portion 345 is formed between the bus bar joining region 362 and the joined portion 372 of the connection bus bar 370. The joining method of the joint portion 345 is the same as that of the joint portion 45 in the first embodiment. The fastening bus bar 360 has higher strength than the connection bus bar 370.

[0098] The fastened portion 361 of the fastening bus bar 360 and the terminal portion 22 of the fuse 20 are electrically connected by being fastened by the bolt B2 and the fastening portion N2. Therefore, the terminal portion 22 of the fuse 20 is electrically connected to the connection bus bar 370 via the fastening bus bar 360.

[0099] In Embodiment 13 shown in FIG. 26, a fastening bus bar 460 is disclosed as a configuration corresponding to the fastening bus bar 605 of Embodiment 5, a connection bus bar 470 is disclosed as a configuration corresponding to the connection bus bar 705 of Embodiment 5, and a fuse connection portion 441 is disclosed as a configuration corresponding to the fuse connection portion 415 of Embodiment 5. The fuse connection portion 441 includes a fuse 20, fastening members (bolt B2, fastening portion N2), a fastening bus bar 460, and a connection bus bar 470.

[0100] The fastening bus bar 460 includes a fastened portion 461 to which the terminal portion 22 of the fuse 20 is connected, and a bus bar joining region 462 extending downward from the trailing edge of the fastened portion 461. Among the fastening bus bar 460, the region excluding the fastened portion 461 fastened by the bolt B2 is the bus bar joining region 462. The connection bus bar 470 includes a joined portion 472 connected to the bus bar joining region 462 of the fastening bus bar 460, and a horizontal portion 470A extending rearward from the lower edge of the joined portion 472.

[0101] The horizontal portion 470A of the connection bus bar 470 is in contact with the bottom surface of the fuse arrangement portion 115A. The heat generated by the fuse 20 is dissipated to the heat dissipation member H through the terminal portion 22, the fastened portion 461, the bus bar joining region 462, the joined portion 472, the horizontal portion 470A, and the bottom surface of the fuse arrangement portion 115A.

[0102] The joined portion 472 of the connection bus bar 470 is electrically connected to the bus bar joining region 462 by joining. A joint portion 445 is formed between the bus bar joining region 462 and the joined portion 472 of the connection bus bar 470. The joining method of the joint portion 445 is the same as that of the joint portion 45 of Embodiment 1. The fastening bus bar 460 has higher strength than the connection bus bar 470.

[0103] The fastened portion 461 of the fastening bus bar 460 and the terminal portion 22 of the fuse 20 are electrically connected by being fastened by the bolt B2 and the fastening portion N2. Therefore, the terminal portion 22 of the fuse 20 is electrically connected to the connection bus bar 470 via the fastening bus bar 460.

[0104] In Embodiment 14 shown in FIG. 27, a fastening bus bar 560 is disclosed as a configuration corresponding to the fastening bus bar 605 of Embodiment 5, a connection bus bar 570 is disclosed as a configuration corresponding to the connection bus bar 705 of Embodiment 5, and a fuse connection portion 541 is disclosed as a configuration corresponding to the fuse connection portion 415 of Embodiment 5. The fuse connection portion 541 includes the fuse 20, fastening members (bolt B2, fastening portion N2), the fastening bus bar 560, and the connection bus bar 570.

[0105] The fastening bus bar 560 includes a fastened portion 561 to which the terminal portion 22 of the fuse 20 is connected, a bus bar joining region 562 extending downward from the front edge of the fastened portion 561, and a horizontal portion 560A extending forward from the lower edge of the bus bar joining region 562. Among the fastening bus bar 560, the region excluding the fastened portion 561 fastened by the bolt B2 is the bus bar joining region 562. The connection bus bar 570 has a joined portion 572 extending in the vertical direction and a horizontal portion 570A extending rearward from the lower edge of the joined portion 572.

[0106] The horizontal portions 560A and 570A are in contact with the bottom surface of the fuse arrangement portion 115A. The heat generated in the fuse 20 is radiated to the heat dissipation member H through the terminal portion 22, the fastened portion 561, the bus bar joining region 562, the horizontal portion 560A, and the bottom surface of the fuse arrangement portion 115A. At the same time, it branches from the bus bar joining region 562 to the joined portion 572 and is radiated to the heat dissipation member H through the horizontal portion 570A and the bottom surface of the fuse arrangement portion 115A. The contact area between the horizontal portions 560A and 570A and the bottom surface of the fuse arrangement portion 115A is larger than the contact area between the horizontal portion 160A in Embodiment 10 and the bottom surface of the fuse arrangement portion 115A. Therefore, the heat dissipation effect of Embodiment 14 is greater than the heat dissipation effect of Embodiment 10.

[0107] The joined portion 572 of the connection bus bar 570 is electrically connected to the bus bar joining region 562 by joining. A joining portion 545 is formed between the bus bar joining region 562 and the joined portion 572 of the connection bus bar 570. The joining method of the joining portion 545 is the same as that of the joining portion 45 in the first embodiment. The fastening bus bar 560 has higher strength than the connection bus bar 570.

[0108] The fastened portion 561 of the fastening bus bar 560 and the terminal portion 22 of the fuse 20 are electrically connected by being fastened by the bolt B2 and the fastening portion N2. Therefore, the terminal portion 22 of the fuse 20 is electrically connected to the connection bus bar 570 via the fastening bus bar 560.

[0109] (Other embodiments) The above-described first to fifth embodiments can be implemented with the following modifications. The above-described first to fifth embodiments can be implemented in combination with each other within a technically non-contradictory range. · In the above-described first to fourth embodiments, a relay is exemplified as the electronic component, but the electronic component does not have to be a relay, and it may have the property of generating heat when energized. The electronic component may be, for example, a fuse, a resistor, a coil, a capacitor, a diode, an IC (Integrated Circuit), or a switching element such as an FET (Field Effect Transistor). Further, in the above-described fifth embodiment, a fuse is exemplified as the electronic component, but the electronic component does not have to be a fuse.

[0110] · In the above-described first to fifth embodiments, an example is given in which the connection bus bar is directly joined to the fastening bus bar, but the connection bus bar may be joined to the fastening bus bar via a conductive member such as solder.

[0111] · In the above-described second and fourth embodiments, a heat dissipation portion formed in the non-energized region is exemplified, but a heat dissipation portion may be formed in the energized region.

[0112] ·In the above-described Embodiment 4, the heat-drawing portion folded back in a U shape was exemplified, but a heat-drawing portion bent in an L shape may also be used.

[0113] ·In the above-described Embodiment 3, the one in which the heat-drawing busbar is clamped together with the fastening busbar was exemplified, but the heat-drawing portion folded back in a U shape as in Embodiment 4 may be clamped together with the fastening busbar.

[0114] ·In the above-described Embodiments 1 to 5, the electrical connection box in which both the fastening busbar and the connection busbar are housed inside the case was exemplified, but an electrical connection box in which at least one of the fastening busbar and the connection busbar is exposed outside the case may also be used.

[0115] ·The fastening busbar may be thicker than the connection busbar.

[0116] ·In the above-described Embodiment 5, heat is radiated from one terminal portion 22, but heat may be radiated from both terminal portions 22.

Explanation of Reference Numerals

[0117] JB, JB2, JB3, JB4, JB5: Electrical connection box 2, 3: External busbar 10, 105: Case 11, 115: Lower case 11A, 115A: Fuse installation portion (cooling surface) 11B: Terminal block 11C: Mounting surface 11D: Positioning portion 11E: Side wall portion 12: Upper case 12A: First busbar housing portion 12B: Second busbar housing portion 20: Fuse (other electronic component) 21: Main body portion 22: Terminal portion 30: Relay (electronic component) 31: Main body portion 32: Partition wall 33: Terminal 34: Recess 40,405: First bus bar 41: Fuse connection part 141,241,341,415,441,541: Fuse connection part (bus bar fastening structure) 42,422,423,424: Relay connection part (bus bar fastening structure) 42A: Insertion hole 43,435: Intermediate part 44: Extension part 45,145,245,345,445,453,545: Joint part 50: Second bus bar 51,512,513,514: Relay connection part 51A: Insertion hole 52: External connection part 60,160,260,360,460,560,602,604,605: Fastening bus bar 160A,260A,560A: Horizontal part 160B,260B: Vertical part 61,161,261,361,461,561,615: Part to be fastened 62,162,262,362,462,562,625: Bus bar joint area 70,170,270,370,470,570,702,703,705: Connecting bus bar 370A,470A,570A: Horizontal part 705A: First horizontal part 705B: First vertical part 705C: Second horizontal part 705D: Second vertical part 705E: Third horizontal part 71,715: Bolt relief hole 72,172,272,372,472,572,725: Part to be joined 80: Thermal extraction bus bar 81: Bolt relief hole B1,B2,B3,B4: Bolts B5,B53: Bolts (fastening members) B51: Bolt head B52: Shaft part H: Thermal extraction member (cooling surface) H2, H4: Heat drawing part HM: Heat dissipation member JP1, JP2, JP3, JP4, JP5, JP6, JP7, JP8, JP9: Joint position R1: Energized area R2, R4: Non-energized area

Claims

1. An electronic component having terminals and generating heat upon energization, A fastening member, A fastening bus bar that is electrically connected to the electronic component by being fastened to the terminals by the fastening member, A connection bus bar that is electrically connected to a portion of the fastening bus bar excluding the fastened portion fastened by the fastening member, and A bus bar fastening structure in which the fastening bus bar has higher strength than the connection bus bar.

2. The fastening member has a bolt head, The connection bus bar has a bolt escape hole for escaping the bolt head and a joined portion formed around the bolt escape hole and joined to the fastening bus bar. The bus bar fastening structure according to claim 1.

3. The bus bar fastening structure according to claim 1, wherein the fastening bus bar has a heat dissipation portion formed in a non-energized region different from an energized region where current flows between the fastening bus bar and the connection bus bar.

4. The bus bar fastening structure according to claim 3, wherein the heat dissipation portion is formed in a folded-back shape.

5. The bus bar fastening structure according to claim 1, further comprising a heat dissipation bus bar co-fastened to the fastening bus bar.

6. The bus bar fastening structure according to claim 1, wherein the fastening bus bar is subjected to surface treatment.

7. The bus bar fastening structure according to claim 1, wherein at least one of the fastening bus bar or the connection bus bar is thermally connected to a cooling surface.

8. The bus bar fastening structure according to claim 1, wherein the thermal conductivity and electrical conductivity of the connection bus bar are higher than those of the fastening bus bar.

9. The bus bar fastening structure according to claim 2, wherein the joint portion between the connection bus bar and the fastening bus bar is at least on the side in the conductive path direction when viewed from the fastening direction of the fastening member.

10. The bus bar fastening structure according to claim 2, wherein the joint position between the connection bus bar and the fastening bus bar is arranged along at least two sides around the fastening member.

11. A bus bar fastening structure according to any one of claims 1 to 10, and An electrical connection box including another electronic component electrically connected to the electronic component via the fastening bus bar and the connection bus bar.

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