WO2021230077A1

WO2021230077A1 - Circuit unit

Info

Publication number: WO2021230077A1
Application number: PCT/JP2021/016882
Authority: WO
Inventors: 昂士井倉; 洋樹下田; 泰次柳田
Original assignee: 株式会社オートネットワーク技術研究所; 住友電装株式会社; 住友電気工業株式会社
Priority date: 2020-05-13
Filing date: 2021-04-28
Publication date: 2021-11-18
Also published as: JP2021180233A

Abstract

Disclosed is a circuit unit having a novel structure that enables connector connection between said circuit unit and a wiring harness, suppression of increase in size of the circuit unit, and reduction of heat generation between connection terminals.　A circuit unit 10 is provided with: a case 14 that houses a circuit member 12; an external connection connector 16 that is provided to the case 14 and has a connection terminal 68; an energization bus bar 18 that constitutes the circuit member 12 and is electrically connected to the connection terminal 68; and a heat transfer part 20 that is provided to the energization bus bar 18 in a thermally transferable manner and is in thermal contact with the case 14.

Description

Circuit unit

This disclosure relates to a circuit unit.

Patent Document 1 discloses a power distribution system for a vehicle (circuit body for a vehicle) including a circuit unit such as an electric junction box mounted on the vehicle. In such a system, the circuit unit includes a connector to which a wire harness (wire bundle) is connected, and the circuit unit and various external devices are connected via the wire harness (wire bundle).

Japanese Unexamined Patent Publication No. 2019-155961

By the way, in recent electric vehicles and hybrid vehicles, high-voltage power is transferred from a high-voltage secondary battery mounted as a power source for driving to a circuit unit and various devices connected to the circuit unit via a high-voltage wire harness. Be supplied. Therefore, there has been a problem that heat generation increases at the contact portion between the connection terminal of the connector provided in the circuit unit and the connection terminal provided in the wire harness.

On the other hand, it is conceivable to increase the heat capacity by increasing the plate thickness of the connection terminal and the energizing bus bar that follows it, but this is not preferable because it causes the cost and size of the circuit unit to increase. Further, by bolting the connection terminal on the circuit unit side and the connection terminal on the harness side, it is conceivable to reduce the contact resistance between the connection terminals and suppress heat generation. However, compared to the case of connector connection, the connection work between the connection terminals becomes complicated, so it cannot be said that this is a preferable response.

Therefore, we will disclose a circuit unit with a new structure that enables connector connection between the circuit unit and the wire harness, suppresses the increase in size of the circuit unit, and reduces heat generation between the connection terminals.

The circuit unit of the present disclosure includes a case for accommodating a circuit member, an external connection connector provided in the case and having a connection terminal, and an energizing bus bar that constitutes the circuit member and electrically connects to the connection terminal. The bus bar for energization is provided with a heat transfer unit that is provided so as to be heat transferable and that is in thermal contact with the case.

According to the present disclosure, it is possible to suppress the increase in size of the circuit unit and reduce the heat generation between the connection terminals while enabling the connector connection between the circuit unit and the wire harness.

FIG. 1 is a vertical sectional view schematically showing a circuit unit according to the first embodiment. FIG. 2 is a vertical cross-sectional view schematically showing a state in which a harness-side connector is connected to an external connection connector of the circuit unit shown in FIG. FIG. 3 is a vertical sectional view schematically showing the circuit unit according to the second embodiment. FIG. 4 is a vertical sectional view schematically showing the circuit unit according to the third embodiment.

<Explanation of Embodiments of the present disclosure>
First, embodiments of the present disclosure will be listed and described.
The circuit unit of the present disclosure is
(1) A case for accommodating a circuit member, an external connection connector provided in the case and having a connection terminal, an energization bus bar constituting the circuit member and electrically connecting to the connection terminal, and the energization. The bus bar is provided with a heat transfer unit that is provided so as to be heat transferable and that is in thermal contact with the case.

According to the circuit unit of the present disclosure, the external connection connector provided on the case has a connection terminal, and the energization bus bar constituting the circuit member is electrically connected to the connection terminal. Thereby, the connection between the circuit unit and the external wire harness can be performed by the connector connection in which the harness side connector provided at the terminal of the wire harness is connected to the external connection connector. Moreover, it has a heat transfer section that is provided so that heat can be transferred to the energizing bus bar that is electrically connected to the connection terminal of the external connection connector, and the heat transfer section is in thermal contact with the case. ing. As a result, the heat generated at the connection terminal is transferred from the energizing bus bar to the case through the heat transfer section, and the heat generated at the connection terminal can be quickly dissipated, and the connection terminal of the external connection connector and the connection terminal of the harness side connector can be quickly dissipated. It is possible to reduce heat generation at the contact site with. As a result, it is possible to reduce heat generation between the connection terminals without requiring an increase in size of the connection terminals and the energizing bus bar.

Although the connection terminal and the energizing bus bar may be separate bodies, it is preferable that the connection terminal is a tab-shaped one integrally provided at the end of the energizing bus bar. This is because the number of parts can be reduced.

Further, the heat transfer unit may be integrally provided on the energizing bus bar, or may be configured by a member separate from the energizing bus bar and provided on the energizing bus bar so that heat can be transferred. May be good.

(2) It is preferable that the heat transfer unit is integrally provided with the energizing bus bar. This is because the heat transfer unit can be provided by using a part of the energizing bus bar, the number of parts can be reduced, and the handleability and assembling property of the parts can be improved.

(3) It is preferable that the heat transfer unit is provided separately from the current-carrying bus bar and is fixed to the current-carrying bus bar so as to be heat transferable. By providing the heat transfer unit as a separate component from the energization bus bar and fixing the heat transfer unit to any position on the energization bus bar so that heat can be transferred, the heat transfer unit can be provided on the energization bus bar. As a result, regardless of the wiring part of the energizing bus bar, the heat transfer part can be placed at any place in the case and thermally contacted with the case, and the heat transfer part can be connected to the circuit unit with a high degree of freedom in design. Can be provided.

(4) It is preferable that the heat transfer portion is in contact with the case via the first heat conduction member. By interposing the first heat conduction member between the heat transfer part and the case, the contact area between the heat transfer part and the case can be secured more stably, and the heat dissipation from the heat transfer part to the case is further improved. This is because it can be improved.

(5) The first heat conductive member is preferably an elastic heat conductive sheet. Since the first heat conductive member has elasticity, the adhesion between the heat transfer portion and the first heat conductive member and between the first heat conductive member and the case can be improved. Therefore, the heat transfer portion can be more reliably brought into contact with the case via the heat conductive sheet. Further, since the first heat conductive member has a sheet shape, it is easy to handle.

(6) It has a second heat conductive member arranged so as to face the heat transfer portion with the case sandwiched between them, and the case comes into contact with an external heat radiating body via the second heat conductive member. It is preferable that Since the portion of the case with which the heat transfer portion contacts is further contacted with the external heat radiating body via the second heat conductive member, the heat transferred from the heat transfer portion to the case is further passed through the second heat conductive member. Heat is transferred to the external radiator. As a result, heat generation between the connection terminals can be reduced more advantageously.

More preferably, it is desirable to use it in combination with the above (4) and (5) to arrange the first heat conductive member between the case and the heat transfer unit. This makes it possible to promote more reliable heat transfer from the heat transfer unit to the case and the external heat radiating body.

Examples of the external heat radiating body include a metal or resin housing having heat dissipation equal to or higher than that of the case, a vehicle body panel, and the like.

(7) The case contains a heat-generating component that constitutes the circuit member and that generates heat by energization that is separate from the connection terminal, and the heat-generating component is provided with the heat transfer unit. It is preferable that the bus bar for energization is in thermal contact with the bus bar. By energizing, not only the heat generated by the connection between the external connection connector and the harness side connector but also the heat generating parts housed in the case generate heat, but the heat generated from the heat generating parts accompanies the connection of both connectors. Along with the heat generation, heat is dissipated from the case through the heat transfer part. Therefore, it is not necessary to separately provide a heat dissipation mechanism for the heat generating component, and the structure of the circuit unit can be simplified or downsized.

<Details of Embodiments of the present disclosure>
Specific examples of the circuit unit of the present disclosure will be described below with reference to the drawings. It should be noted that the present disclosure is not limited to these examples, but is shown by the scope of claims and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

<Embodiment 1>
Hereinafter, Embodiment 1 of the present disclosure will be described with reference to FIGS. 1 and 2. The circuit unit 10 of the first embodiment is a junction box for high voltage in a battery pack housing mounted on a vehicle (not shown) such as an electric vehicle or a hybrid vehicle. In the following description, the X direction in the figure will be described as the right side and the Y direction as the upper side. The X direction (right direction) and the Y direction (upward direction) do not necessarily correspond to the directions of the circuit unit 10 in the mounted state on the vehicle. Further, FIGS. 1 to 4 shown below are schematic views, and do not limit the specific structure of the circuit unit according to the present disclosure. Further, for a plurality of the same members, a reference numeral may be added to only a part of the members, and the reference numeral may be omitted for other members.

<Circuit unit 10>
The circuit unit 10 includes a circuit member 12 and a case 14 for accommodating the circuit member 12. Further, the circuit unit 10 includes an external connection connector 16 provided in the case 14, an energizing bus bar 18 constituting the circuit member 12, and a heat transfer unit 20 provided in the energizing bus bar 18.

<Case 14>
In the first embodiment, the case 14 has a box shape as a whole. The case 14 can be divided in the vertical direction. That is, the case 14 is configured to include the upper upper case 22 and the lower lower case 24. Both the upper case 22 and the lower case 24 can be formed of a hard synthetic resin having an insulating property. As a result, in the first embodiment, the case 14 has an insulating property. Alternatively, at least one of the upper case 22 and the lower case 24 may be made of metal. Even when the upper case 22 and / or the lower case 24 is made of metal in this way, an insulating tube (insulation coating) having thermal conductivity is provided on the surface of the metal upper case 22 and / or the lower case 24. Therefore, the insulation of the entire case 14 is ensured.

The upper case 22 has a box shape that opens downward. The upper case 22 includes, for example, an upper bottom wall 26 having a rectangular shape in a plan view, and a peripheral wall 28 projecting downward from the outer peripheral edge portion of the upper bottom wall 26 and continuing over the entire circumference in the circumferential direction. ing.

The upper bottom wall 26 is provided with a relay fixing portion 30 to which the relay 42 described later is fixed and a fuse fixing portion 32 to which the fuse 44 is fixed. The relay fixing portion 30 and the fuse fixing portion 32 have a substantially cylindrical shape or a substantially columnar shape protruding downward from the upper bottom wall 26. Nuts (not shown) are arranged inside the relay fixing portion 30 and the fuse fixing portion 32.

Further, in the upper bottom wall 26, at a position (the right end portion in FIGS. 1 and 2) away from the relay fixing portion 30 and the fuse fixing portion 32, a substantially cylindrical shape protruding inward (downward). A cylinder wall portion 34 is provided. The inner hole of the cylinder wall portion 34 penetrates the upper bottom wall 26 in the plate thickness direction (vertical direction). As a result, the cylinder wall portion 34 opens outward (upward) on the upper surface of the upper bottom wall 26. Further, an annular bottom wall portion 36 projecting to the inner peripheral side is provided at the lower end portion of the cylinder wall portion 34. As a result, a through hole 38 is formed in the substantially center of the bottom wall portion 36. In the first embodiment, the cylinder wall portion 34 has a rectangular cylinder shape. Further, the through hole 38 has a rectangular shape in a plan view. The connector housing 40 of the external connection connector 16 is configured to include the cylinder wall portion 34 and the bottom wall portion 36.

The lower case 24 has a flat plate shape as a whole. The lower case 24 has a shape substantially corresponding to the upper bottom wall 26 of the upper case 22 in a plan view. That is, in the first embodiment, the lower case 24 has a rectangular shape in a plan view. The lower case 24 is superposed on the lower opening of the upper case 22 and fixed to each other by conventionally known fixing means such as bolt fixing, uneven fitting, adhesion and welding. As a result, the lower opening of the upper case 22 is covered with the lower case 24 to form the case 14.

<Circuit member 12>
In the first embodiment, the circuit member 12 includes a relay 42, a fuse 44, and a bus bar 18 for energization. The relay 42 and the fuse 44 are heat-generating components that generate heat when energized. The relay 42, the fuse 44, and the energizing bus bar 18 are housed in the case 14, and in the first embodiment, they are fixed to the upper case 22.

Specifically, the relay 42 includes a hollow relay body 46 having a substantially rectangular parallelepiped shape. From the relay main body 46, a plurality of leg portions 48 are provided so as to project to the outside of the relay main body 46. Each of these legs 48 is formed with a bolt insertion hole 50 that penetrates in the thickness direction (vertical direction). Then, the relay 42 is fixed to the upper case 22 by superimposing the relay fixing portion 30 in the upper case 22 and the leg portion 48 in the relay 42 and inserting and fastening the bolt 52.

A connection portion 54 of the relay 42 is formed in front of the relay 42 (on the left side in FIGS. 1 and 2). A pair of connecting

portions

54, 54 are provided in front of the relay 42. These pair of connecting

portions

54, 54 are arranged in the direction orthogonal to the paper surface in FIGS. 1 and 2. Although only one connection portion 54 is shown in FIGS. 1 and 2, the other connection portion (54) is provided on the front side or the back side of the paper in FIGS. 1 and 2.

Further, the fuse 44 includes a fuse body 56 having a rectangular parallelepiped shape. From the fuse main body 56, connecting

portions

58, 58 having a flat plate shape and having conductivity are projected on both sides in the left-right direction. Bolt insertion holes 60, 60 penetrating in the thickness direction (vertical direction) are formed in these

connection portions

58, 58. Then, the fuse 44 is fixed to the upper case 22 by superimposing the fuse fixing portion 32 on the upper case 22 and the connecting portion 58 on the fuse 44 and inserting and fastening the bolt 62.

<Bus bar 18 for energization>
The energizing bus bar 18 is made of a conductive metal plate material. The energizing bus bar 18 is formed by bending a metal plate material into a predetermined shape by pressing or the like. In the first embodiment, two energizing bus bars 18 (a first energizing bus bar 18a and a second energizing bus bar 18b) are provided. The first energizing bus bar 18a electrically and thermally connects the relay 42 and the fuse 44. Further, the second energizing bus bar 18b is electrically and thermally connected to the fuse 44.

Specifically, the first energizing bus bar 18a extends in the left-right direction as a whole. The left end of the first energizing bus bar 18a extends in the vertical direction. Further, the right end portion of the first energizing bus bar 18a extends in the left-right direction. Bolt insertion holes 64 and 64 are formed at both left and right ends of the first energizing bus bar 18a so as to penetrate in the thickness direction, respectively.

Then, one connection portion 54 of the relay 42 and the left bolt insertion hole 64 in the first energization bus bar 18a are overlapped with each other, and the bolt 66 is inserted and fastened to connect the relay 42 and the first energization. The bus bar 18a and the bus bar 18a are fixed to each other. Further, the bolt insertion hole 60 in the left connection portion 58 of the fuse 44 and the right bolt insertion hole 64 in the first energizing bus bar 18a are overlapped with each other, and the bolt 62 is inserted and fastened together to tighten the fuse. The left connection portion 58 of the 44 and the right end portion of the first energizing bus bar 18a are fixed to the upper case 22. As a result, the relay 42 and the fuse 44 are electrically and thermally connected to each other through the first energizing bus bar 18a. A wire harness connected to a battery (not shown) is electrically connected to the other connection portion (54) of the relay 42, for example.

Further, the left end portion of the second energizing bus bar 18b extends in the left-right direction. Further, the right end portion of the second energizing bus bar 18b extends in the vertical direction. A bolt insertion hole 67 is formed through the left end of the second energizing bus bar 18b in the thickness direction.

Then, the bolt insertion hole 60 in the connection portion 58 on the right side of the fuse 44 and the bolt insertion hole 67 in the second energizing bus bar 18b are overlapped with each other, and the bolt 62 is inserted and tightened together to the right of the fuse 44. The connecting portion 58 and the left end portion of the second energizing bus bar 18b are fixed to the upper case 22. As a result, the fuse 44 and the second energizing bus bar 18b are electrically and thermally connected.

<Connector for external connection 16>
The right end portion of the second energizing bus bar 18b extends from the lower side to the upper side by being bent. Then, by fixing the second energizing bus bar 18b to the upper case 22, the right end portion of the second energizing bus bar 18b is inserted into the through hole 38 provided in the upper case 22. As a result, the upper end portion of the second energizing bus bar 18b at the right end portion protrudes outward (upward) from the bottom wall portion 36 of the upper case 22. The portion of the second energizing bus bar 18b that protrudes outward from the bottom wall portion 36 is the connection terminal 68.

This connection terminal 68 can be electrically connected to the harness side connector 72 provided at the terminal of the external wire harness 70. Therefore, in the first embodiment, the connection terminal 68 is electrically connected to the second energizing bus bar 18b. Specifically, a male tab-shaped connection terminal 68 is configured by one end of the second energizing bus bar 18b in the length direction. The male tab-shaped connection terminal 68 can be electrically connected to the harness-side connector 72 having a female tab shape. The external connection connector 16 is configured to include the connection terminal 68 and the connector housing 40. That is, the external connection connector 16 has a connection terminal 68. The external connection connector 16 is provided on the case 14 (upper case 22).

In the first embodiment, the connection terminal 68 (second energizing bus bar 18b) is formed in a size that does not protrude outward (upward) from the upper case 22. That is, the connection terminal 68 is provided so as not to protrude outward (upward) from the upper case 22 and to be exposed to the outside. In other words, the connection terminal 68 is located inside the connector housing 40 (cylinder wall portion 34). As a result, the possibility that the user will unintentionally contact the connection terminal 68 is reduced, and the insulation of the circuit unit 10 can be ensured.

<Heat transfer unit 20>
As described above, one end (upper end of the right end) of the second energizing bus bar 18b in the length direction is the connection terminal 68. Further, the other end (left end) of the second energizing bus bar 18b in the length direction is fixed to the upper case 22 together with the connection portion 58 of the fuse 44. The intermediate portion in the length direction of the second energizing bus bar 18b between both ends in the length direction protrudes downward and extends horizontally with a predetermined dimension. In the first embodiment, in the intermediate portion in the length direction of the second energizing bus bar 18b, the portion protruding downward and extending in the horizontal direction is the heat transfer portion 20. Therefore, in the first embodiment, the heat transfer unit 20 is integrally provided with the second energizing bus bar 18b. The heat transfer unit 20 is in thermal contact with the case 14 (lower case 24). That is, heat can be transferred from the second energizing bus bar 18b to the case 14 (lower case 24) by the heat transfer unit 20.

<

Heat conduction sheet

74,76>
In the first embodiment, the heat transfer unit 20 is in contact with the lower case 24 via the first heat conduction member. Further, a second heat conduction member is provided on the side opposite to the heat transfer portion 20 with the case 14 (lower case 24) sandwiched between them. That is, in the first embodiment, the heat transfer portion 20 and the second heat conduction member are arranged to face each other with the lower case 24 interposed therebetween. In particular, in the first embodiment, the first and second heat conductive members are heat

conductive sheets

74 and 76, respectively. Then, the case 14 (lower case 24) is in contact with the external heat radiating body 78 via the second heat conductive member (heat conductive sheet 76).

The heat

conductive sheets

74 and 76 have a flat sheet shape in the vertical direction and are made of a synthetic resin having a higher thermal conductivity than air. Specifically, a silicone-based resin, a non-silicone-based acrylic resin, a ceramic-based resin, or the like can be used. More specifically, a heat conductive silicone rubber and the like can be mentioned. The heat

conductive sheets

74 and 76 have flexibility and elasticity, and can be elastically deformed so that the thickness dimension changes according to the force applied in the vertical direction. In the first embodiment, the heat

conductive sheets

74 and 76 are adopted as the first and second heat conductive members, respectively, but none of the first and second heat conductive members is limited to this embodiment and has an arbitrary shape. The heat conductive member of can be adopted. For example, a heat dissipation gap filler or a heat conductive grease made of a silicone-based resin may be used.

Further, the external heat radiating body 78 is not limited, but for example, a metal or synthetic resin housing, a body panel, or the like having heat dissipation equal to or higher than that of the case 14 (lower case 24) is adopted. obtain. In the first embodiment, the heat radiating body 78 is composed of a housing of a battery pack made of metal.

The first heat conductive member (heat conductive sheet 74) may be fixed to the heat transfer portion 20 and / or the lower case 24 with an adhesive or the like, or may not be fixed to either the heat transfer portion 20 or the lower case 24. You may. Further, the second heat conductive member (heat conductive sheet 76) may be fixed to the lower case 24 and / or the radiator 78 with an adhesive or the like, and may not be fixed to either the lower case 24 or the radiator 78. You may. The heat conductive sheet 74 is preferably sandwiched between the heat transfer unit 20 and the lower case 24 in a compressed state. By being compressed, the heat transfer sheet 74 can come into contact with the heat transfer portion 20 and the lower case 24 with a high degree of adhesion. Therefore, the heat conductive sheet 74 can efficiently transfer heat from the heat transfer unit 20 to the lower case 24. Similarly, the heat conductive sheet 76 is preferably sandwiched in a compressed state between the lower case 24 and the radiator 78 in the vertical direction. The heat conductive sheet 76 can be in contact with the lower case 24 and the radiator 78 with a high degree of adhesion by being compressed. Therefore, the heat conductive sheet 76 can efficiently transfer heat from the lower case 24 to the radiator 78.

<Assembly process of circuit unit 10>
Subsequently, a specific example of the assembly process of the circuit unit 10 will be described. The assembly process of the circuit unit 10 is not limited to the following description.

First, the upper and

lower cases

22, 24, the relay 42, the fuse 44, and the first and second energizing

bus bars

18a and 18b are prepared. Then, after fixing the first energizing bus bar 18a and the relay 42 with the bolt 66, the relay 42 is fixed to the upper bottom wall 26 of the upper case 22 in a state where the upper case 22 is turned upside down. The energizing bus bar 18a, the fuse 44, and the second energizing bus bar 18b are mounted. Subsequently,

bolts

52, 62, and 62 are inserted and fastened to the first energizing bus bar 18a to which these relays 42 are fixed, the fuse 44, and the second energizing bus bar 18b. As a result, the first energizing bus bar 18a to which the relay 42 is fixed, the fuse 44, and the second energizing bus bar 18b are fixed to the upper case 22. At the same time as fixing the second energizing bus bar 18b to the upper case 22, the upper end of the right end of the second energizing bus bar 18b is inserted into the through hole 38 in the upper case 22 to insert the connection terminal 68 (external). The connection connector 16) is configured.

After that, the lower case 24 in which the heat

conductive sheets

74 and 76 are fixed on both the upper and lower surfaces is covered and fixed to the opening of the upper case 22 from above. As a result, the circuit member 12 is housed in the case 14. Finally, it is turned upside down to complete the circuit unit 10. The heat conduction sheet 74 (first heat conduction member) may be fixed to the lower surface of the heat transfer portion 20 in the second energization bus bar 18b before the lower case 24 is fixed to the upper case 22. Further, the order of assembling the relay 42, the fuse 44, and the first and second energizing

bus bars

18a and 18b to the upper case 22 is not limited, and the relay 42 is fixed to, for example, the upper case 22. Later, the first energizing bus bar 18a may be fixed to the relay 42.

The circuit unit 10 assembled in this way is fixed to the heat radiating body 78 with the heat conductive sheet 76 (second heat conductive member) sandwiched between them, for example, with bolts or the like. Further, as shown in FIG. 2, by connecting the harness side connector 72 provided at the terminal of the external wire harness 70 to the external connection connector 16 provided in the case 14 (upper case 22), the connector 72 is connected. The circuit member 12 and various devices are electrically connected to each other through the wire harness 70.

In the circuit unit 10 of the first embodiment, the harness side connector 72 provided on the external wire harness 70 and the external connection connector 16 provided on the case 14 (upper case 22) can be connected to each other. .. That is, the electrical connection between the circuit member 12 and various devices is achieved by inserting the harness side connector 72 having a female tab shape into the connection terminal 68 of the external connection connector 16 having a male tab shape. Will be done. The heat generated at the contact portion between the

connectors

16 and 72 is dissipated through the case 14 (lower case 24) via the heat transfer portion 20 in the second energizing bus bar 18b. As a result, heat generation due to contact between both

connectors

16 and 72 is eliminated without increasing the thickness dimension of the connection terminal 68 (second energizing bus bar 18b), and the size of the external connection connector 16 is increased. Can be avoided. In particular, by adopting the structure of the first embodiment, the circuit unit 10 can be used as a junction box for high voltage, but the external connection connector 16 can be avoided from becoming large, and the circuit unit 10 (circuit member 12) and the external can be used. It is possible to achieve both electrical connection by the connector of the wire harness 70.

Further, if the heat dissipation structure of the present disclosure is not adopted, a certain amount of heat generation is expected when the circuit unit and the external wire harness are connected to the connector. Therefore, in order to improve the heat resistance of the external wire harness, the wire is used. It is also conceivable to increase the diameter of the harness or increase the thickness of the insulating coating in the wire harness. However, according to the circuit unit 10 of the first embodiment, the heat generated by the contact between the external connection connector 16 and the harness side connector 72 is eliminated or reduced, so that the diameter of the wire harness 70 is increased and the insulating coating is thickened. It is possible to reduce the possibility that a problem such as a problem will occur. That is, by adopting the heat dissipation structure of the present disclosure, not only the size of the external connection connector 16 and the circuit unit 10 can be reduced, but also the diameter of the wire harness 70 connected to the circuit unit 10 can be prevented from increasing. You can also do it.

Further, in the first embodiment, since the heat transfer unit 20 is provided in the second energizing bus bar 18b constituting the connection terminal 68, it is possible to avoid an increase in the number of parts and the structure of the circuit unit 10. Can also be made simpler. In particular, by providing the heat transfer unit 20 in the energization bus bar 18 (second energization bus bar 18b) constituting the heat generating portion, it is possible to improve the heat transfer efficiency, that is, the heat dissipation efficiency.

Further, in the first embodiment, since the first heat conduction member (heat conduction sheet 74) is provided between the heat transfer portion 20 and the case 14 (lower case 24), the heat transfer efficiency to the case 14 is further improved. Improvements can be made. In particular, since the first heat conductive member is composed of the heat conductive sheet 74, not only the handleability of the first heat conductive member can be improved, but also the heat transfer portion 20 and the case 14 can be more reliably thermally heated. Can be contacted with.

Furthermore, in the first embodiment, since the case 14 is in thermal contact with the radiator 78 via the second heat conductive member (heat conductive sheet 76), the heat transferred to the heat transfer unit 20 is transferred to the heat transfer unit 20. Heat can be dissipated from the radiator 78 via the heat conductive sheet 74, the lower case 24, and the heat conductive sheet 76. As a result, the heat dissipation efficiency can be further improved.

Further, in the first embodiment, a heat generating component (relay 42 and fuse 44) that generates heat by energization is provided inside the case 14. The heat of the relay 42 and the fuse 44 generated by energization can also be dissipated from the lower case 24 or the radiator 78 via the heat transfer portion 20 of the energization bus bar 18 (second energization bus bar 18b). That is, since the relay 42 and the fuse 44 are thermally connected by the first energizing bus bar 18a, the heat generated by the relay 42 can be transferred to the fuse 44. Further, since the fuse 44 is thermally connected to the second energizing bus bar 18b, the heat generated by the relay 42 and the heat generated by the fuse 44 are transferred to the second energizing bus bar 18b. Heat is dissipated through the section 20. Therefore, in the circuit unit 10 of the first embodiment, not only the heat generated between the

connectors

16 and 72 but also the heat generated in the circuit unit 10 can be transferred and dissipated.

<Embodiment 2>
Hereinafter, Embodiment 2 of the present disclosure will be described with reference to FIG. The circuit unit 80 of the second embodiment has the same structure as the circuit unit 10 of the first embodiment, but the heat transfer portion 82 provided in the second energization bus bar 18b is a case without using the first heat conduction member. It differs from the circuit unit 10 of the first embodiment in that it is in direct contact with 14 (lower case 24). In the following description, the members or parts substantially the same as those in the first embodiment are designated by the same reference numerals as those in the first embodiment in the drawings, and detailed description thereof will be omitted.

In the second embodiment, since the heat transfer unit 82 is in direct contact with the case 14 (lower case 24), the heat accompanying the contact between the connection terminal 68 and the harness side connector 72 is transferred to the case 14 via the heat transfer unit 82. Heat is transferred to and dissipated from the case 14. Further, also in the second embodiment, since the second heat conductive member (heat conductive sheet 76) is provided at a position facing the heat transfer portion 82 with the case 14 sandwiched between them, the heat transferred to the case 14 is transferred to the case 14. , Heat is transferred to the heat radiating body 78 via the second heat conductive member (heat conducting sheet 76), and heat is radiated from the heat radiating body 78.

Therefore, the circuit unit 80 in the second embodiment can exert the same effect as the circuit unit 10 in the first embodiment. In particular, in the second embodiment, since the first heat conductive member (heat conduction sheet 74) is not provided, the number of parts can be reduced.

<Embodiment 3>
Hereinafter, the third embodiment of the present disclosure will be described with reference to FIG. The circuit unit 90 of the third embodiment has the same structure as the circuit unit 10 of the first embodiment, but the heat transfer unit 92 is provided in the heat dissipation bus bar 94 which is separate from the second energization bus bar 18b. This is different from the circuit unit 10 of the first embodiment.

That is, in the third embodiment, the upper bottom wall 26 of the upper case 22 is provided with a bolt fixing portion 96 different from the relay fixing portion 30 and the fuse fixing portion 32. A nut (not shown) is also fixed inside the bolt fixing portion 96 in an embedded state. Further, in the second energizing bus bar 18b, a bolt is inserted between the right end portion constituting the connection terminal 68 and the left end portion overlapped with and fixed to the right connection portion 58 of the fuse 44. An insertion hole 98 is formed.

The heat radiating bus bar 94 is made of, for example, the same metal plate material as the first and second energizing

bus bars

18a and 18b. The heat dissipation bus bar 94 is formed by bending a metal plate material into a predetermined shape by press working or the like. In the third embodiment, the heat dissipation bus bar 94 extends in the vertical direction as a whole. Further, the upper end portion and the lower end portion of the heat dissipation bus bar 94 extend in the left-right direction, respectively. A bolt insertion hole 100 that penetrates in the thickness direction (vertical direction) is formed in the upper end portion of the heat radiating bus bar 94. Further, the lower end portion of the heat dissipation bus bar 94 is a heat transfer portion 92 extending in the left-right direction. The material of the heat radiating bus bar 94 does not have to be the same metal as the first and second energizing

bus bars

18a and 18b. That is, the heat dissipation bus bar 94 does not necessarily have to have conductivity, and may be made of a material having thermal conductivity. Therefore, as the material of the heat dissipation bus bar 94, it is possible to select a material having better heat dissipation than the first and second

energization bus bars

18a and 18b, and it is also possible to improve the heat dissipation.

The heat radiating bus bar 94 is overlapped with the intermediate portion in the length direction of the second energizing bus bar 18b, and is fixed to the upper case 22 by a bolt 102. Specifically, the bolt insertion hole 98 of the second energizing bus bar 18b and the bolt insertion hole 100 of the heat dissipation bus bar 94 are aligned, and the bolt 102 is inserted and fastened together to cause the second energization. The bus bar 18b for heat dissipation and the bus bar 94 for heat dissipation are fixed to the upper case 22. As a result, the heat dissipation bus bar 94 provided with the heat transfer unit 92 is fixed to the second energization bus bar 18b so that heat can be transferred. The heat transfer portion 92, which is the lower end portion of the heat dissipation bus bar 94, is in thermal contact with the case 14 (lower case 24) via the first heat conduction member (heat conduction sheet 74).

In the circuit unit 90 of the third embodiment, the second energizing bus bar 18b and the heat radiating bus bar 94 are integrally fixed by the bolt 102. Since the lower end portion of the heat radiating bus bar 94 is the heat transfer section 92, the heat transfer section 92 is provided on the second energization bus bar 18b via the heat radiating bus bar 94. Then, the heat generated by the contact between the connection terminal 68 and the harness side connector 72 is transferred to the heat transfer unit 92 through the second energization bus bar 18b and the heat dissipation bus bar 94. This heat is dissipated by the case 14 (lower case 24) and / or the radiator 78.

Therefore, the circuit unit 90 of the third embodiment can exhibit the same effect as the circuit unit 10 of the first embodiment. In particular, by providing the heat-dissipating bus bar 94 that is separate from the energizing bus bars 18 (first and second energizing

bus bars

18a, 18b) as in the third embodiment, the energizing bus bars 18 (first and second) are provided. The heat transfer portion can be provided at a desired position regardless of the wiring mode of the second energizing

bus bars

18a and 18b). Therefore, the degree of freedom in design can be improved, and the heat transfer unit 92 can be provided in the case 14 with high space efficiency.

<Other embodiments>
The techniques described herein are not limited to the embodiments described above and in the drawings, and for example, the following embodiments are also included in the technical scope of the techniques described herein.

(1) In the above embodiment, the case 14 is configured to include a box-shaped upper case 22 and a flat plate-shaped lower case 24, but includes, for example, a flat plate-shaped upper case and a box-shaped lower case. It may be composed of. Alternatively, both the upper case and the lower case may have a box shape. Further, in the above embodiment, the relay 42, the fuse 44, the energizing bus bars 18 (first and second energizing

bus bars

18a, 18b) and the like constituting the circuit member 12 are all fixed to the box-shaped upper case 22. However, the circuit member may be fixed to any of a flat plate-shaped upper case, a lower case, a box-shaped lower case, and the like.

(2) In the above embodiment, the connector housing 40 of the external connection connector 16 is configured by utilizing a part of the upper bottom wall 26 of the upper case 22, but the connector housing is formed separately from the case. It may be fixed to the case by post-assembly. Then, even if the connection terminal protrudes into the connector housing assembled to the case, the harness side connector is inserted into this connector housing, and the connection terminal and the harness side connector are connected inside the connector housing. good. Further, when the connector housing is separated from the case, it is preferable that the connector housing is attached to the case, for example, with one touch by utilizing, for example, uneven fitting.

(3) In the above embodiment, the connection terminal 68 is formed in a size that can be accommodated in the connector housing 40, but the connection terminal may protrude outward from the connector housing (or case). Alternatively, the connection terminal may be housed in the case without being exposed to the outside. For example, by inserting the harness side connector of the wire harness into the through hole penetrating the upper bottom wall of the upper case, the connection terminal is connected inside the case. The terminal and the connector on the harness side may be in contact with each other. That is, the cylinder wall portion 34 and the bottom wall portion 36 in the above embodiment may not be provided.

(4) In the above embodiment, the connection terminal 68 is configured by one end (right end) in the length direction of the second energization bus bar 18b, but the energization bus bar and the connection terminal are separate. It may be electrically connected. That is, the connection terminal does not have to be tab-shaped as in the above embodiment, and any conventionally known connection terminal in the connector can be adopted.

(5) In the above embodiment, the second heat conductive member (heat conductive sheet 76) is provided between the case 14 (lower case 24) and the radiator 78, but the second heat conductive member is not essential. No. That is, for example, the case and the radiator are arranged so close to each other that heat can be transferred via the air layer between them, and the heat transferred to the case is transferred to the radiator without passing through the second heat conductive member. Heat may be transferred to dissipate heat. In this case, it can be grasped that the heat transferred to the heat transfer unit is dissipated by the case.

(6) In the above embodiment, the relay 42 and the fuse 44 are provided, and these are members that generate heat in the

circuit units

10, 80, 90, but one or both of the relay and the fuse are the present. It is not essential for the circuit unit according to the disclosure. That is, a member that generates heat may be provided in the circuit unit other than the relay and the fuse, or a member that generates heat other than the contact between the connection terminal and the harness side connector may not be provided in the circuit unit. When a member (relay 42 and / or fuse 44) that generates heat other than the contact between the connection terminal 68 and the harness side connector 72 is provided as in the embodiment, the heat dissipation mechanism of these members is the embodiment. The heat transfer mechanism is not limited to the one using the

heat transfer portions

20, 82, 92 as described above, and a heat radiation mechanism other than the heat radiation mechanism using the heat transfer unit may be separately provided.

(7) In the above embodiment, as the energizing bus bar 18, the first energizing bus bar 18a and the second energizing bus bar 18b are provided, but the energizing bus bar may be one or three or more. But it may be. Further, in the third embodiment, the heat dissipation bus bar 94 is fixed to the second energizing bus bar 18b, but instead of or in addition to the second energizing bus bar, the first energizing bus bar is used. It may be fixed. That is, not only one bus bar for heat dissipation but also a plurality of bus bars may be provided. Further, in the above embodiment, the

heat transfer portions

20, 82, 92 are located on the electric path from the relay 42 to the connection terminal 68, but the part other than the electric path in the energization bus bar is used as a case. A heat transfer portion may be formed so as to project toward the case and thermally contact the case.

(8) The first and second heat conductive members are not limited to the mode of the heat conductive sheet as in the above embodiment, and any conventionally known mode such as gel or grease can be adopted.

(9) In the above embodiment, the

circuit units

10, 80, 90 have been exemplified as a junction box for high voltage in the battery pack, but the present invention is not limited to this embodiment.

(10) In the above embodiment, the insulation of the entire case is ensured by covering both or one of the upper case and the lower case with a synthetic resin, or covering the surfaces of the upper case and the lower case made of metal with an insulating coating. It was, but it is not limited to this. Both the upper case and the lower case may be made of metal. In this case, the insulation between the energizing bus bar and the case may be secured by using a heat conductive member having an insulating property, and the insulation may be individually secured by an insulating coating or the like for other parts requiring insulation.

10 Circuit unit 12 Circuit member 14 Case 16 External connection connector 18 Energizing bus bar 18a First energizing bus bar 18b Second energizing bus bar 20 Heat transfer part 22 Upper case 24 Lower case 26 Upper bottom wall 28 Peripheral wall 30 Relay fixing part 32 Fuse fixing part 34 Cylinder wall part 36 Bottom wall part 38 Through hole 40 Connector housing 42 Relay (heat generating part)
44 Fuse (heat generating part)
46 Relay body 48 Leg 50 Bolt insertion hole 52 Bolt 54 Connection 56 Fuse body 58 Connection 60 Bolt insertion hole 62 Bolt 64 Bolt insertion hole 66 Bolt 67 Bolt insertion hole 68 Connection terminal 70 Wire harness 72 Harness side connector 74 Heat conduction Sheet (first heat conductive member)
76 Heat conduction sheet (second heat conduction member)
78 Heat radiator 80 Circuit unit 82 Heat transfer unit 90 Circuit unit 92 Heat transfer unit 94 Heat transfer bus bar 96 Bolt fixing part 98,100 Bolt insertion hole 102 Bolt

Claims

A case for accommodating circuit members and
An external connection connector provided in the case and having a connection terminal,
An energizing bus bar that constitutes the circuit member and is electrically connected to the connection terminal,
A circuit unit including a heat transfer unit provided on the energization bus bar so as to be heat transferable and in thermal contact with the case.
The circuit unit according to claim 1, wherein the heat transfer unit is integrally provided with the energizing bus bar.
The circuit unit according to claim 1, wherein the heat transfer unit is provided separately from the current-carrying bus bar and is fixed to the current-carrying bus bar so as to transfer heat.
The circuit unit according to any one of claims 1 to 3, wherein the heat transfer unit is in contact with the case via the first heat conduction member.
The circuit unit according to claim 4, wherein the first heat conductive member is an elastic heat conductive sheet.
It has a second heat conduction member that is arranged to face the heat transfer portion with the case in between.
The circuit unit according to any one of claims 1 to 5, wherein the case comes into contact with an external heat radiating body via the second heat conductive member.
The case contains a heat-generating component that constitutes the circuit member and generates heat by energization that is separate from the connection terminal.
The circuit unit according to any one of claims 1 to 6, wherein the heat generating component is in thermal contact with the energizing bus bar provided with the heat transfer unit.