Connection structure and electrical junction box

Abstract

The objective is to obtain a connection structure and electrical junction box that can efficiently dissipate the heat generated by the busbars and relays that constitute the electrical circuit. [Solution] A connection structure 1 for multiple relays and busbars, wherein the relays include a first relay 10 that switches a first circuit C1, which is a predetermined electrical circuit, to an energized state or an unenergized state, and a second relay 40 that switches a second circuit C2, which is different from the first circuit C1, to an energized state or an unenergized state. The busbars include a first busbar 20 connected to the first relay 10 and constituting the first circuit C1, and a second busbar 60 connected to the second relay 40 and constituting the second circuit C2. The first busbar 20 and the second busbar 60 are connected in a way that allows for heat dissipation, and when the first circuit C1 is energized, the second busbar 60 is unenergized.

Description

Technical Field

[0001] The present invention relates to a connection structure and an electrical connection box.

Background Art

[0002] Conventionally, an electrical connection box having a plurality of electrical circuits has been known (see, for example, Patent Document 1). As shown in FIG. 2 of Patent Document 1, the electronic unit box (electrical connection box) described in Patent Document 1 includes a housing case 3 and a housing case 4, a plurality of relays 7 disposed in the housing case 3 and the housing case 4, and a bus bar 9 connecting the relays 7 to each other. Further, the electronic unit box includes a heat dissipation plate 6 integrated with the bus bar 9 via a heat conduction sheet 10. The heat dissipation plate 6 diffuses the heat generated by the relays 7 and the bus bar 9 to the outside when the electronic unit box is energized.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the electronic unit box of Patent Document 1 mentioned above, as shown in Figure 4 of Reference Document 1, multiple relay terminal holes 17 are formed on a single busbar 9, and multiple relays 7 are connected together via these relay terminal holes 17. In such a connection structure, even if one relay 7 is turned off, the other relays 7 turn on, and the heat generated by the other relays 7 is constantly conducted to the busbar 9, causing the relays 7 and busbar 9 to constantly overheat. This overheating is particularly noticeable when the electronic unit box is used in a high-power circuit. To improve the heat dissipation effect of the relays 7 and busbar 9, measures such as enlarging the heat sink 6 or increasing the mass of the busbar 9 can be considered, but these measures are not easy due to layout constraints within the housing cases 3 and 4.

[0005] The objective of the present invention is to provide a connection structure and an electrical junction box that can efficiently dissipate the heat generated by busbars and relays that constitute an electrical circuit. [Means for solving the problem]

[0006] To solve the aforementioned problems and achieve the objective, the connection structure is a connection structure of relays and busbars constituting a plurality of electrical circuits, wherein the relays include a first relay that switches a first circuit, which is a predetermined electrical circuit, to a state of energized or de-energized, and a second relay that switches a second circuit, which is an electrical circuit different from the first circuit, to a state of energized or de-energized, and the busbars include a first busbar connected to the first relay and constituting the first circuit, and a second busbar connected to the second relay and constituting the second circuit, wherein the first busbar and the second busbar are connected in a manner that allows for heat dissipation, and the second busbar is de-energized when the first circuit is energized.

[0007] Furthermore, the electrical junction box is characterized by comprising the above-mentioned connection structure and a case that houses the connection structure. [Effects of the Invention]

[0008] According to the present invention, it is possible to obtain a connection structure and an electrical connection box that can efficiently dissipate the heat generated by the busbars and relays constituting the electrical circuit. [Brief explanation of the drawing]

[0009] [Figure 1] A perspective view showing a part of an electrical junction box equipped with a connection structure according to one embodiment. [Figure 2] A cross-sectional view showing a portion of the cross-section as seen by the arrow AA in Figure 1. [Figure 3] A perspective view showing a part of an electrical junction box equipped with a modified connection structure. [Figure 4] A cross-sectional view showing a portion of the cross-section as seen through the line BB in Figure 3. [Modes for carrying out the invention]

[0010] The connection structure 1 and the electrical junction box 100 equipped with the connection structure 1 will be described below. In the figure, the symbols X, Y, and Z indicate directions and are orthogonal to each other. The direction indicated by the symbol X is called the "front-to-back direction X," with one side of the front-to-back direction X being called the "front side X1" and the other side being called the "rear side X2." The direction indicated by the symbol Y is called the "width direction Y," with one side of the width direction Y being called the "right side Y1" and the other side being called the "left side Y2." The direction indicated by the symbol Z is called the "up-down direction Z," with one side of the up-down direction Z being called the "upper side Z1" and the other side being called the "downward side Z2." These definitions of directions are for the sake of explanation only and do not limit the directions in which the connection structure 1 and the electrical junction box 100 are manufactured or used. In addition, in the figure, when there are multiple configurations with similar functions, such as the configurations of the second busbar 60 described later, some symbols may be omitted to avoid making the figure more complex.

[0011] The electrical junction box 100 is installed in vehicles such as hybrid vehicles, electric vehicles, or fuel cell vehicles, and constitutes multiple electrical circuits between the battery and the inverter, etc. The electrical junction box 100 houses a connection structure 1 in a case (not shown). The connection structure 1 is a structure in which multiple electronic components constituting an electrical circuit and multiple conductors are connected to each other. The connection structure 1 includes a first relay 10, a second relay 40, and a fuse 50 as multiple electronic components. The connection structure 1 also includes busbars as conductors connecting the electronic components, and the busbars consist of a first busbar 20, a second busbar 60, a third busbar 70, and a fourth busbar 80.

[0012] Furthermore, there are two of each of the second relay 40, the second busbar 60, the third busbar 70, and the fourth busbar 80, which are directly or indirectly connected to the second relay 40, and the fuse 50. These are symmetrical with respect to a virtual line L that extends in the front-to-back direction X through the center of the width direction Y of the first relay 10. The structures of the second relay 40, the second busbar 60, the third busbar 70, the fourth busbar 80, and the fuse 50 are almost identical. For this reason, in the following description, the structures of the second relay 40, the second busbar 60, the third busbar 70, the fourth busbar 80, and the fuse 50 located to the left of the virtual line L (Y2) will be described in detail. Detailed descriptions of the structures located to the right of the virtual line L (Y1) will be omitted or simplified.

[0013] The first relay 10 and the first busbar 20 will now be described. The first relay 10 includes a first main body 11 formed in a substantially rectangular box shape using a material such as resin. As shown in Figure 2, a projection 12 is formed on the end face of the first main body 11 facing the front side X1, projecting toward the front side X1. As shown in Figure 1, a partition wall 13 is formed in the center of the surface of the first main body 11 facing the front side X1, projecting toward the front side X1 and extending in the vertical direction Z, with projections 12 formed on the right side Y1 and left side Y2 of this partition wall 13, respectively. As shown in Figure 2, the first busbar 20 is attached to the end face of the projection 12 facing the front side X1. The first busbar 20 is a conductor formed by bending a conductive metal plate material such as copper or a copper alloy, and is formed in an overall plate shape. The first busbar 20 includes a first relay side connection part 21 (extended part) that constitutes the front side X1 portion.

[0014] The first relay-side connection portion 21 is formed in a rectangular shape and extends in the vertical direction Z (a predetermined direction) along the end face of the front X1 of the protrusion 12 of the first relay 10. The surface of the first relay-side connection portion 21 facing the front X1 constitutes the first-side connection portion 22 (connection portion) which is connected in contact with the second busbar 60, which will be described later. A bolt hole 21a is formed in the center of the first relay-side connection portion 21, penetrating in the direction of the plate thickness. The first relay-side connection portion 21 is fixed to the protrusion 12 of the first relay 10 and the first relay-side connection portion 61 of the second busbar 60, which will be described later, by conductive first flange bolts 30 (fastening members). The upper end Z1 of the first relay-side connection portion 21 is bent to the rear X2 (a bending direction different from the predetermined direction) to constitute a bent portion 23. An upper plate portion 24 is continuously formed on the bent portion 23. The upper plate portion 24 is formed in a rectangular plate shape and extends to the rear side X2 along the wall surface facing the upper side Z1 of the first relay 10.

[0015] The rear X2 end of the upper plate portion 24 constitutes a connection portion 25 for other components, which has a smaller width dimension than the rest of the upper plate portion 24. As shown in Figure 1, a through hole 26 is formed in the rear X2 portion of the connection portion 25 for other components, penetrating in the plate thickness direction, and the connection portion 25 for other components is connected to an object other than the first relay 10 by a fastening member (not shown) inserted through the through hole 26. In this way, the first busbar 20 has the first relay-side connection portion 21 at one end screwed to the first relay 10, and the connection portion 25 at the other end is connected to an object other than the first relay 10. In the first relay 10 and first busbar 20 configured in this way, although not shown, a switch with a fixed contact and a movable contact is arranged inside the first main body portion 11 of the first relay 10. For example, a part of the circuit on the fixed contact side inside the first main body portion 11 is composed of the first flange bolt 30 on the right side Y1 and the first busbar 20 on the right side Y1 in Figure 1.

[0016] Furthermore, a portion of the circuit on the movable contact side within the first main body 11 is composed of the first flange bolt 30 on the left side Y2 and the first busbar 20 on the left side Y2 in Figure 1. The operation of the movable contact is controlled by a computer such as an ECU, thereby switching the switch on and off.

[0017] Next, the second relay 40, fuse 50, second busbar 60, third busbar 70, and fourth busbar 80 will be described. The second relay 40 includes a second main body 41 formed in a roughly rectangular box shape using a material such as resin. As shown in Figure 1, a second partition wall 42 is formed in the center of the left end face of the second main body 41 facing left Y2, projecting to the left Y2 and extending in the vertical direction Z. Inside the second main body 41 of the second relay 40, similar to the first relay 10, a switch (not shown) is installed that allows the operation of the movable contacts to be controlled by a computer such as an ECU. The fuse 50 prevents overcurrent by melting or other means when a current exceeding a predetermined amount flows through the second circuit C2 in the electrical connection box 100, which will be described later, and includes a box-shaped fuse body 51. The fuse body 51 is positioned between the first relay 10 and the second relay 40. Flange-shaped connecting plate portions 52 are formed on both the left and right end faces of the fuse body 51, each projecting outward in the width direction Y.

[0018] The second busbar 60 connects the first relay 10 and the fuse 50, and is also indirectly connected to the second relay 40 via the fuse 50 and the fourth busbar 80, forming a busbar that constitutes the second circuit C2 described later. As shown in Figure 2, the second busbar 60 includes a first relay side connection portion 61 (extended portion), a rear bent portion 63, an upper wall portion 64, a front bent portion 65, and a fuse side connection portion 66. The first relay side connection portion 61 is formed in a rectangular shape and is located on the front side X1 of the first relay side connection portion 21 of the first busbar 20. The first relay side connection portion 61 extends in the vertical direction Z (a predetermined direction) along the surface of the first relay side connection portion 21 facing the front side X1. The end face of the first relay side connection portion 61 facing the rear side X2 constitutes a second side connection portion 62 (connection portion) that is connected in contact with the first relay side connection portion 21 of the first busbar 20. A bolt hole 61a is formed in the center of the first relay-side connection portion 61, extending through in the thickness direction of the plate, through which the first flange bolt 30 described above passes.

[0019] The rear bent portion 63 is bent forward to the front side X1 from the end portion on the upper side Z1 of the first relay side connection portion 61. The upper wall portion 64 is formed in a rectangular shape and extends to the front side X1 continuously with the rear bent portion 63. As shown in FIG. 1, the front bent portion 65 is bent downward to the lower side Z2 from the left half Y2 of the end portion on the front side X1 of the upper wall portion 64. The fuse side connection portion 66 is formed in a rectangular shape and extends to the lower side Z2 continuously with the front bent portion 65. The surface facing the rear side X2 of the fuse side connection portion 66 abuts against the surface facing the front side X1 of the connection plate portion 52 on the right side Y1 of the fuse 50.

[0020] In the second bus bar 60 formed as described above, as shown in FIG. 2, the first relay side connection portion 61 is screwed to the first relay side connection portion 21 by the first flange bolt 30 inserted through the bolt hole 61a and the bolt hole 21a. Thereby, the first bus bar 20 and the second bus bar 60 are connected by the conductive first flange bolt 30 (fastening member). At the time of this connection, as shown in FIG. 2, the first relay side connection portion 21 and the first relay side connection portion 61 overlap in the plate thickness direction, and substantially the entire surface of the first side connection portion 22 of the first bus bar 20 and substantially the entire surface of the second side connection portion 62 of the second bus bar 60 are in contact. Therefore, for example, when one of the first relay side connection portion 21 and the first relay side connection portion 61 generates heat, the heat is likely to diffuse toward the other. That is, the first bus bar 20 and the second bus bar 60 are connected so as to be able to radiate heat to each other.

[0021] Further, since the first relay side connection portion 21 and the first relay side connection portion 61 overlap in the plate thickness direction, the plate thickness as a bus bar at this overlapping portion is large, and it is difficult for this portion to generate heat compared to a bus bar with a small plate thickness. Note that the first relay side connection portion 21 and the first relay side connection portion 61 having such a heat dissipation function are set to have substantially the same plate thickness as shown in FIG. 2, but it is not necessarily required to have the same plate thickness, and they may be set arbitrarily.

[0022] For example, the plate thickness of one of the first relay side connection portions 21 and the first relay side connection portion 61 may be set larger or smaller than the plate thickness of the other. According to this, since the plate thickness of the portions having a heat dissipation function can be adjusted between the first relay side connection portion 21 and the first relay side connection portion 61, compared with the case of increasing the plate thickness with a single bus bar to enhance the heat dissipation function, the following can be achieved. That is, it is possible to make it difficult for the layout in the electrical connection box 100 to be restricted with respect to the shape and arrangement of the bus bars (the first bus bar 20, the second bus bar 60). For this reason, the degree of freedom in the design of the first bus bar 20 and the second bus bar 60 can be improved. Also, the plate thickness per bus bar can be made smaller, and the manufacturing cost of one bus bar can be reduced.

[0023] On the other hand, as shown in FIG. 1, in the second bus bar 60, the fuse side connection portion 66 is connected to the fuse 50 by a fifth flange bolt 67 that inserts the connection plate portion 52 on the right side Y1 of the fuse 50 in the plate thickness direction.

[0024] The third bus bar 70 is a bus bar that connects the second relay 40 and a target other than the second relay 40. The third bus bar 70 includes a second relay side connection portion 71 (extension portion), a bent portion 72, a first flat plate portion 73, and a second flat plate portion 74. The second relay side connection portion 71 is formed in a rectangular shape and rises upward Z1 (predetermined direction) from a portion on the rear side X2 of the second partition wall 42 of the end face facing the left side Y2 of the second main body portion 41. The bent portion 72 is bent to the right side Y1 (a bending direction different from the predetermined direction) from the upper end portion Z1 of the second relay side connection portion 71.

[0025] The first flat plate portion 73 is formed in a rectangular shape and extends to the right Y1 along the upper wall surface Z1 of the second main body portion 41, continuous with the bent portion 72. The second flat plate portion 74 is formed in a rectangular shape and extends to the rear X2 from the right Y1 end of the first flat plate portion 73. A through hole 74a is formed in the rear X2 portion of the second flat plate portion 74, penetrating in the thickness direction. In the third busbar 70 formed in this way, the second flat plate portion 74 is connected to an object other than the second relay 40 by a fastening member (not shown) inserted through the through hole 74a. On the other hand, in the third busbar 70, the second relay side connection portion 71 is screwed to the second relay 40 by a second flange bolt 75 which is inserted in the thickness direction of the second relay side connection portion 71 and fastened to the second main body portion 41.

[0026] The fourth busbar 80 is a busbar that connects the second relay 40 and the fuse 50. The fourth busbar 80 comprises a second relay side connection portion 81 (extended portion), a first bent portion 82, a ceiling portion 83, a second bent portion 84, and a fuse side connection portion 85. The second relay side connection portion 81 is formed in a rectangular shape and rises upward Z1 from the portion X1 in front of the second partition wall 42 on the left side Y2 end face of the second main body portion 41. The first bent portion 82 bends to the right Y1 from the upper Z1 end of the second relay side connection portion 81. The ceiling portion 83 is formed in a roughly L-shape with a portion that extends to the right Y1 in continuity with the first bent portion 82 and a portion that extends to the front X1.

[0027] The second bend 84 bends downward Z2 from the front end X1 of the ceiling portion 83. The fuse-side connection portion 85 is formed in a rectangular shape and extends downward Z2 in continuity with the second bend 84. The rear-facing surface of the fuse-side connection portion 85 abuts against the front-facing surface X1 of the connection plate portion 52 on the left side Y2 of the fuse 50. In the fourth busbar 80 formed in this way, the second relay-side connection portion 81 is screwed to the second relay 40 by a third flange bolt 86 that is inserted in the thickness direction of the second relay-side connection portion 81 and fastened to the second main body portion 41. On the other hand, in the fourth busbar 80, the fuse-side connection portion 85 is screwed to the connection plate portion 52 on the left side Y2 by a fourth flange bolt 87 that is inserted in the thickness direction of both the fuse-side connection portion 85 and the connection plate portion 52 on the left side Y2 of the fuse 50.

[0028] In the second relay 40, fuse 50, and second busbar 60 configured as described above, although not shown in the diagram, a switch with fixed contacts and movable contacts is arranged inside the second body 41 of the second relay 40. For example, the second flange bolt 75 and the third busbar 70 constitute a part of the circuit on the fixed contact side within the second body 41. The third flange bolt 86 and the third busbar 70, among others, constitute a part of the circuit on the movable contact side within the second body 41. The switch is turned on and off by controlling the operation of the movable contacts with a computer such as an ECU.

[0029] Next, the operation of the electrical junction box 100 equipped with connection structure 1 will be described. In the state shown in Figure 1, first the switch of the first relay 10 is turned on, and the switch of the second relay 40 is turned off. As a result, the first circuit C1 (a predetermined electrical circuit) through which current flows is energized as follows. When the first circuit C1 is energized, current flows in the following order to the other component side connection part 25, the upper plate part 24, the bent part 23, the first relay side connection part 21 of the first busbar 20 on the right side Y1, the first flange bolt 30 on the right side Y1, and the fixed contact (not shown) inside the first main body part 11. The current that has flowed up to the fixed contact (not shown) then flows in the following order to the movable contact (not shown), the first flange bolt 30 on the left side Y2, the first relay side connection part 21, the bent part 23, the upper plate part 24, and the other component side connection part 25 of the first busbar 20 on the left side Y2.

[0030] On the other hand, with the switch of the second relay 40 turned off, the second circuit C2, which consists of the first busbar 20, the first flange bolt 30, the second busbar 60, the fuse 50, the fourth busbar 80, the second relay 40, and the third busbar 70, is de-energized. In this state, if a relatively large current flows through the first circuit C1, the first relay 10 and the first busbar 20, which constitute the first circuit C1, will generate heat. However, as described above, when the first circuit C1 is energized, the second circuit C2 is de-energized, so the second busbar 60 is de-energized and does not generate heat like the first busbar 20. The first relay-side connection portion 21 of the first busbar 20 is screwed to the first relay-side connection portion 61 of the second busbar 60 via the first flange bolt 30. Therefore, the heat from the first busbar 20 is dissipated to the second busbar 60 via the first relay side connection 21 and the first flange bolt 30. In other words, the second busbar 60 functions as a heat dissipation part for the first relay 10 and the first busbar 20. On the other hand, when the switch of the first relay 10 is turned off and the switch of the second relay 40 is turned on, the first circuit C1 switches to a non-energized state, and the second circuit C2 switches to an energized state.

[0031] As explained above, the connection structure 1 is provided with a first circuit C1 consisting of a first relay 10 and a first busbar 20, which can be switched between energized and de-energized by the first relay 10. The connection structure 1 is also provided with a second circuit C2 consisting of a second relay 40, a fuse 50, a first busbar 20, a second busbar 60, a third busbar 70, and a fourth busbar 80, which can be switched between energized and de-energized by the second relay 40. In other words, the connection structure 1 is provided with at least two electrical circuits. When the first circuit C1 is energized, the second busbar 60, which is connected to the first busbar 20 in a way that allows heat dissipation, is de-energized.

[0032] As described above, according to the embodiment described, for example, when a large current flows through the first circuit C1 and the first relay 10 and the first busbar 20 generate heat, the second busbar 60 becomes de-energized, making it difficult for the second busbar 60 to generate heat. Furthermore, since the second busbar 60 is connected to the first busbar 20 in a way that allows for heat dissipation, the second busbar 60 functions as a heat dissipation part for the first busbar 20. Therefore, a connection structure 1 can be obtained that can efficiently dissipate the heat generated in the first busbar 20 (busbar) and the first relay 10 (relay) that constitute the first circuit C1 (electrical circuit).

[0033] Furthermore, according to this embodiment, the first busbar 20 and the second busbar 60 can be easily connected using the first flange bolt 30 (fastening member).

[0034] Furthermore, according to this embodiment, heat can be efficiently dissipated at the connection portion (first side connection portion 22, second side connection portion 62) where the first busbar 20 and the second busbar 60 are overlapped in the thickness direction. In addition, since the thickness of the connection portion can be set arbitrarily, a wide variety of thicknesses can be used for the connection portion between the first busbar 20 and the second busbar 60. For this reason, when mounting the connection structure 1 inside the electrical connection box 100, the shape and size of the first busbar 20 and the second busbar 60 are less affected by layout constraints. Moreover, the heat dissipation function described above tends to increase with increasing busbar thickness, and this thickness can be the sum of the thicknesses of the connection portions of the first busbar 20 and the second busbar 60. Therefore, the thickness of each busbar can be reduced compared to a heat dissipation section constructed by increasing the thickness of individual busbars. For this reason, the processability of each busbar can be improved.

[0035] Furthermore, according to this embodiment, the degree of design freedom for the first busbar 20 and the second busbar 60 can be easily improved by combining an extended portion such as the first relay-side connection portion 21 with a bent portion such as the bent portion 23.

[0036] Furthermore, according to this embodiment, an electrical junction box 100 can be obtained that can efficiently dissipate the heat generated by the first busbar 20 and the first relay 10 that constitute the first circuit C1.

[0037] Next, a modified example will be described. Figure 3 is a perspective view showing a part of an electrical junction box 100A equipped with a modified connection structure 1A. Figure 4 is a cross-sectional view showing a part of the cross section in the direction of the arrow BB in Figure 3. In the modified example, the connection structure 1A of the electrical junction box 100A includes a fourth busbar 80A and a second busbar 60A. The fourth busbar 80A corresponds to the fourth busbar 80 described above, and the second busbar 60A corresponds to the second busbar 60. The second busbar 60A is formed with a larger plate thickness compared to the first busbar 20. The second busbar 60A includes a first relay side connection portion 68a, a rear bent portion 68b, a side wall portion 68c, a front bent portion 68d, and a fuse side connection portion 68e.

[0038] The first relay-side connector 68a is formed in a rectangular shape and is positioned on the front side X1 of the first busbar 20's first relay-side connector 21. The first relay-side connector 68a extends in the width direction Y along the surface of the first relay-side connector 21 facing the front side X1, and also protrudes from the first relay-side connector 21 to the left side Y2.

[0039] As shown in Figure 4, the end face of the first relay-side connection portion 68a facing the rear side X2 constitutes a second-side connection portion 69 (connection portion) that is connected in contact with the first relay-side connection portion 21 of the first busbar 20. A bolt hole 68a1 is formed in the center of the first relay-side connection portion 68a, penetrating in the thickness direction of the plate, and the first flange bolt 30 described above passes through it. In this way, the first relay-side connection portion 68a is screwed to the first relay-side connection portion 21. As shown in Figure 3, the rear bend portion 68b bends from the left side Y2 end of the first relay-side connection portion 68a toward the front side X1. The side wall portion 68c is formed in a rectangular plate shape and extends toward the front side X1, continuous with the rear bend portion 68b.

[0040] The forward bend portion 68d is bent to the right Y1 from the front end X1 of the side wall portion 68c. The fuse-side connection portion 68e is formed in a rectangular plate shape and extends to the right Y1, continuous with the forward bend portion 68d. The rear X2-facing surface of the fuse-side connection portion 68e abuts against the front X1-facing surface of the left Y2 connection plate portion 52 of the fuse 50. The fuse-side connection portion 68e is then screwed to the left Y2 connection plate portion 52 by a fifth flange bolt 67 that passes through the fuse-side connection portion 68e and the left Y2 connection plate portion 52 of the fuse 50 in the thickness direction.

[0041] The fourth busbar 80A includes a second relay-side connection portion 81, a first bent portion 82, a first ceiling portion 88a, a second ceiling portion 88b, a third ceiling portion 88c, a second bent portion 88d, and a fuse-side connection portion 88e. The structure of the second relay-side connection portion 81 and the first bent portion 82 is the same as in the embodiment described above, so a detailed explanation is omitted. The first ceiling portion 88a is formed in the shape of a rectangular plate and extends to the right Y1, continuous with the first bent portion 82. The second ceiling portion 88b is formed in the shape of a rectangular plate and extends to the front X1, continuous with the right Y1 end of the first ceiling portion 88a. The third ceiling portion 88c is formed in the shape of a rectangular plate and extends to the right Y1, continuous with the front X1 end of the second ceiling portion 88b.

[0042] The second bent portion 88d is continuous with the front end X1 of the third ceiling portion 88c and bends downward Z2. The fuse-side connection portion 88e is formed in a rectangular plate shape and extends downward Z2, continuous with the second bent portion 88d. The rear-facing surface of the fuse-side connection portion 88e is in contact with the front-facing surface of the connection plate portion 52 on the right side Y1 of the fuse 50. In the fourth busbar 80A formed in this way, the second relay-side connection portion 81 is screwed to the second relay 40 by a third flange bolt 86 which is inserted in the thickness direction of the second relay-side connection portion 81 and fastened to the second main body portion 41. On the other hand, in the fourth busbar 80A, the fuse-side connection portion 88e is screwed to the connection plate portion 52 on the right side Y1 by a fourth flange bolt 87 which is inserted in the thickness direction of both the fuse-side connection portion 88e and the connection plate portion 52 on the right side Y1 of the fuse 50.

[0043] As described above, the modified version can achieve the same functions and effects as the embodiment described above. Furthermore, this modified version can also be applied when the first relay-side connection portion 68a of the second busbar 60A extends in the width direction Y. In other words, the present invention can be applied to connection structures that include busbars of various shapes.

[0044] It should be noted that the embodiment and modifications described above merely represent one aspect of the connection structure 1 and the electrical connection box 100, and the embodiment is not limited to these. For example, the first relay 10, the second relay 40, and the fuse 50 mentioned in this embodiment are merely examples of electronic components, and other electronic components may be appropriately selected and added. The fuse 50 may also be omitted. Furthermore, electrical circuits other than the first circuit C1 and the second circuit C2 may be provided within the electrical connection box 100. Also, the fastening member does not have to be the first flange bolt 30; for example, the fastening member may be made of conductive bolts and washers. In addition, connections between busbars and relays, or between busbars, may be made using members other than fastening members, or connections between busbars and relays, or between busbars, may be made without using such members, for example, by soldering. [Explanation of Symbols]

[0045] C1 1st circuit C2 2nd circuit 1. Connection structure 10. 1st Relay 20 First bus 40. 2nd Relay 60 Second bus

Claims

1. A connection structure for relays and busbars that constitute multiple electrical circuits, The relay comprises a first relay that switches a predetermined electrical circuit, a first circuit, to a state of energized or de-energized state, and a second relay that switches a second circuit, which is an electrical circuit different from the first circuit, to a state of energized or de-energized state. The busbar comprises a first busbar connected to the first relay and constituting the first circuit, and a second busbar connected to the second relay and constituting the second circuit. The first busbar and the second busbar are connected in a way that allows for heat dissipation. A connection structure characterized in that the second busbar is de-energized when the first circuit is energized.

2. The connection structure according to claim 1, characterized in that the first busbar and the second busbar are connected by a conductive fastening member.

3. The connection structure according to claim 2, characterized in that the connection portion of the first busbar and the second busbar is made of a plate thickness that is arbitrarily set and is connected in a state of contact in the plate thickness direction.

4. The connection structure according to claim 1, characterized in that the first busbar and the second busbar each include an extended portion extending in a predetermined direction and a bent portion bending in a bending direction different from the predetermined direction.

5. An electrical connection box comprising the connection structure described in claim 1 and a case for housing the connection structure.

Images