WO2021230125A1

WO2021230125A1 - Circuit structure

Info

Publication number: WO2021230125A1
Application number: PCT/JP2021/017349
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: 2020-05-15
Filing date: 2021-05-06
Publication date: 2021-11-18

Abstract

Provided is a circuit structure comprising a heat-generating component which generates heat when electrically energized and which also includes a terminal 15, a metal busbar 20 which is connected to the terminal 15 and which includes an insulating resin layer 26 on the surface thereof, a heat transfer member 49 which contacts the portion of the busbar 20 where the resin layer 26 is formed and which absorbs heat transferred from the busbar 20 through the resin layer 26, and a case 40 having a metal portion that contacts the heat transfer member 49 and absorbs heat transferred from the heat transfer member 49.

Description

Circuit configuration

This disclosure relates to a circuit configuration.

According to the technique described in JP-A-2018-93711, the first bus bar connected to the relay terminal of the relay is heat-transferred to the metal case lower member via an insulating heat conductive sheet. Is in contact with. The heat generated by the relay during energization is transferred from the relay terminal to the first bus bar, and is transferred from the first bus bar to the lower member of the case via the heat conductive sheet. The heat transferred to the case lower member is rapidly conducted to the metal case lower member and dissipated to the outside from the lower surface of the case lower member. As a result, the heat generated by the relay during energization is quickly dissipated to the outside, so that the relay is prevented from becoming locally hot.

Japanese Unexamined Patent Publication No. 2018-93711

According to the above configuration, the first bus bar connected to the relay terminal of the relay and the metal case lower member are electrically insulated by a heat conductive sheet. However, when the voltage applied to the relay becomes high, there is a concern that the heat conductive sheet cannot sufficiently secure the insulating property between the first bus bar and the lower member of the case.

The present disclosure has been completed based on the above circumstances, and an object of the present disclosure is to provide a circuit configuration having further improved insulation.

In the present disclosure, a heat-generating component that generates heat when energized and has terminals, a metal bus bar that is connected to the terminals and has an insulating resin layer on the surface, and the resin layer of the bus bars are formed. The insulating heat transfer member that contacts the bus bar and transfers heat from the bus bar through the resin layer, and the portion that contacts the heat transfer member and transfers heat from the heat transfer member are metal. It is a case made of made and a circuit configuration provided.

According to the present disclosure, the insulation of the circuit structure can be improved.

FIG. 1 is a schematic diagram showing a configuration in which a storage pack according to the first embodiment is mounted on a vehicle. FIG. 2 is a schematic cross-sectional view showing a storage pack. FIG. 3 is a cross-sectional view showing an electrical junction box.

[Explanation of Embodiments of the present disclosure]
First, embodiments of the present disclosure will be listed and described.

(1) The present disclosure comprises a circuit structure, that is, a heat-generating component that generates heat when energized and has a terminal, a metal bus bar that is connected to the terminal and has an insulating resin layer on the surface, and the above-mentioned. A heat transfer member in which heat is transferred from the bus bar through the resin layer in contact with the portion of the bus bar on which the resin layer is formed, and a heat transfer member in contact with the heat transfer member to transfer heat from the heat transfer member. A case is provided in which the transmitted portion is made of metal.

The heat generated by the heat-generating parts when energized is transferred from the terminals to the bus bar. The heat transferred to the bus bar is transferred to the heat transfer member via the resin layer. The heat transferred to the transfer member is transferred to the case. As a result, it is possible to prevent the heat-generating component from being trapped in heat and the heat-generating component from becoming locally hot.

The bus bar and the case are electrically insulated by the resin layer on the surface of the bus bar.

(2) The heat transfer member is made of an insulating material.

Since the bus bar and the case are electrically insulated by the resin layer on the surface of the bus bar and the insulating heat transfer member, the insulating property between the bus bar and the case can be further improved.

(3) It is preferable that the resin layer has a heat radiating portion that does not come into contact with the heat transfer member, and the resin layer has higher heat radiating performance than the metal constituting the bus bar.

The resin layer can efficiently radiate the heat transferred from the heat generating component to the bus bar and the heat generated from the bus bar from the heat radiating part that does not come into contact with the heat transfer member.

(4) In the case, it is preferable that the bus bar is arranged at a distance from the heat generating component.

Since there is a gap between the heat-generating parts and the bus bar, the heat generated by the heat-generating parts is efficiently dissipated into the case. This improves the heat dissipation of the heat-generating parts.

(5) An inner case is arranged inside the case, and the heat generating component and the bus bar are housed in the inner case. The inner case has a through window portion penetrating the inner case. It is preferably formed.

From the through window part, the heat generated from the heat generating parts and the bus bar is dissipated to the outside of the inner case through the through window part.

(6) The inner case has an opening that opens in the wall portion on the heat transfer member side, and the bus bar or the heat transfer member is exposed from the opening to the outside of the inner case, and the heat transfer member. Is in contact with the case.

Heat is transferred to the bus bar, resin layer, heat transfer member, and case through the opening. As a result, it is possible to prevent the inside of the inner case from becoming locally hot.

(7) The heat transfer member is preferably an elastic sheet.

Since the heat transfer member is an elastic sheet, if the heat transfer member is sandwiched between the resin layer and the case in a compressed state, the sheet will be in close contact with the resin layer and the case. Therefore, the heat transfer member can come into contact with the resin layer and the case with a high degree of adhesion, and the heat of the bus bar can be efficiently transferred from the resin layer to the case.

[Details of Embodiments of the present disclosure]
Hereinafter, embodiments of the present disclosure will be described. 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>
The first embodiment of the present disclosure will be described with reference to FIGS. 1 to 3. The power storage pack 2 (an example of a circuit configuration) according to the present embodiment is mounted on a vehicle 1 such as an electric vehicle or a hybrid vehicle, and is used as a drive source for the vehicle 1. In the following description, with respect to a plurality of members, only some of the members may be designated with reference numerals, and the reference numerals of other members may be omitted.

[overall structure]
As shown in FIG. 1, a power storage pack 2 is arranged near the center of the vehicle 1. A PCU3 (Power Control Unit) is arranged at the front of the vehicle 1. The storage pack 2 and the PCU 3 are connected by a wire harness 4. The storage pack 2 and the wire harness 4 are connected by a connector (not shown). The power storage pack 2 has a plurality of power storage elements (not shown). The power storage element may be a secondary battery such as a nickel hydrogen secondary battery or a lithium ion secondary battery, or may be a capacitor.

[Storage pack 2]
As shown in FIG. 2, the storage pack 2 has a case 40. Inside the case 40, a power storage module 12 to which a plurality of power storage elements are electrically connected and a relay 14 (an example of a heat generating component) housed in the inner case 30 are connected via a bus bar 20. There is.

In the present embodiment, the power storage module 12 is configured by electrically connecting a plurality of power storage elements in series. The power storage module 12 may include a configuration in which some power storage elements are connected in parallel. The power storage module 12 is housed in the case 40.

As shown in FIG. 3, the case 40 has a metal case lower member 41. The case 40 is configured by connecting a case lower member 41 and a case upper member (not shown). The case lower member 41 includes a bottom plate portion 42 and an outer peripheral wall portion 43 projecting downward from the outer peripheral edge of the bottom plate portion 42. The case lower member 41 is formed of a metal such as iron, iron alloy, aluminum, or aluminum alloy. In this embodiment, for example, the case lower member 41 is formed by die-casting an aluminum alloy. As a result, the heat dissipation of the case lower member 41 can be improved. The case upper member may be made of metal or synthetic resin.

[Electrical junction box 13]
A bus bar 20 and a relay 14 are housed inside the inner case 30. The inner case 30 covers the bus bar 20 and the relay 14 from above and from the side. The inner case 30, the bus bar 20, and the relay 14 constitute an electrical connection box 13. The electric junction box 13 energizes or cuts off the current output from the storage pack 2 to the external circuit.

As shown in FIG. 3, the inner case 30 is mounted on the upper surface of the case lower member 41 and is fixed to the case lower member 41 by bolts 60. A gap 50 is formed between the case lower member 41 and the inner case 30 by the leg portions 37 extending downward from the inner case 30. The heat transfer member 49 is laminated in the gap 50, and the inner case 30 is arranged on the upper side of the heat transfer member 49. The heat transfer member 49 has a flat shape in the vertical direction. The heat transfer member 49 may be a solid formed in a plate shape or a sheet shape, or may be formed of a material having an irregular shape such as an adhesive, grease, gel, or a gap filler. The heat transfer member 49 is made of a material having higher thermal conductivity than air. When the heat transfer member 49 is a solid, at least the upper surface and the lower surface of the heat transfer member 49 are formed of an insulating synthetic resin. The heat transfer member 49 may be elastically deformable or plastically deformable.

The inner case 30 is formed of an insulating synthetic resin. The inner case 30 has an upper wall 31, a side wall 32 extending downward from the side edge of the upper wall 31, and a lower wall 33 that closes the lower end edge of the side wall 32. The lower wall 33 has an opening 36 that opens downward. Legs 37 are formed at the lower end of the inner case 30 so as to project downward. By screwing the bolt 60 into the leg portion 37 from above, the inner case 30 and the case lower member 41 are fixed.

The upper wall 31 of the inner case 30 is formed with a through window portion 34 having a slit shape that penetrates the upper wall 31 up and down. The number of through-window portions 34 is not particularly limited, and may be one or a plurality. Below the through window portion 34, the relay case 16 of the relay 14 and the bus bar 20 are located. When the upper wall 31 is viewed from above, the relay case 16 and the bus bar 20 can be visually recognized from the through window portion 34.

A pressing portion 35 extending downward is formed on the lower surface of the upper wall 31 of the inner case 30. The pressing portion 35 is formed in a wall shape extending in the vertical direction. As will be described later, the bus bar 20 is pressed from above the heat transfer member 49 by the pressing portion 35.

As shown in FIG. 3, a bus bar 20 and a relay 14 are arranged inside the inner case 30. The number of bus bars 20 arranged in the inner case 30 is not particularly limited, and may be one or a plurality of two or more. Further, the number of relays 14 arranged in the inner case 30 is not particularly limited, and may be one or a plurality of two or more. A mounting portion 39 for mounting the relay 14 is formed on the lower surface of the upper wall 31 of the inner case 30 so as to extend downward. A relay 14 is fixed to the lower end of the mounting portion 39 by bolts 61.

The relay 14 is configured by housing the relay body inside a relay case 16 made of an insulating material such as synthetic resin. The relay body has a fixed contact (not shown), a movable piece that can be attached to and detached from the fixed contact (not shown), and an exciting coil (not shown) that switches the connection state between the movable piece and the fixed contact. Have. A terminal 15 electrically connected to a fixed contact of the relay body is exposed on the outside of the relay case 16 of the relay 14.

In such a relay 14, heat is likely to be generated near the internal fixed contact. This internal contact is connected to a terminal 15, and a bus bar 20, which will be described later, is connected to the terminal 15 by a bolt 62. Therefore, in the embodiment, as will be described later, in the bus bar 20, the cooling property of the relay 14 is improved by facilitating heat dissipation in the portion close to the terminal 15.

Specifically, in the relay 14, one end of the bus bar 20 is connected to the terminal 15. Further, the other end of the bus bar 20 is led out from the inner case 30 and is electrically connected to the power storage module 12.

The bus bar 20 is covered with a resin layer 26 made of an insulating synthetic resin except for one end connected to the terminal 15. The resin layer 26 may be coated with a paint by a known method, or may be formed by immersing the resin layer 26 in a liquid synthetic resin. Further, a known heat-shrinkable tube may be fitted onto the bus bar 20 and formed by heating and shrinking the heat-shrinkable tube. As described above, the resin layer 26 can be formed by any method.

As the synthetic resin constituting the resin layer 26, one having excellent thermal radioactivity can be used. As such a synthetic resin, for example, a material capable of selectively radiating an electromagnetic wave having a wavelength of 2 μm to 50 μm is preferable. As the color of the resin layer 26, for example, black or orange is preferable because it has excellent thermal radioactivity.

The bus bar 20 has a connection end 25 connected to the terminal 15. As described above, the resin layer 26 is not formed on the connection end portion 25, and the metal constituting the bus bar 20 is exposed. The bus bar 20 and the relay 14 are spaced apart from each other.

The bus bar 20 has a descending portion 21 extending downward from the connecting end portion 25, a lateral portion 22 extending laterally from the lower end portion of the descending portion 21, and an ascending portion extending upward from the end portion of the lateral portion 22. It has a 23 and an external connection portion 24 extending laterally from the upper end portion of the ascending portion 23 toward the power storage module 12.

Of the bus bar 20, the portion near the lower end of the descending portion 21, the lower surface of the side row portion 22, and the portion near the lower end of the ascending portion 23 are openings 36 formed in the lower wall 33 of the inner case 30. It is led out from the inside of the inner case 30 to the outside through the inner case 30. Of the bus bar 20, a portion of the descending portion 21 near the lower end, a lower surface of the side row portion 22, and a portion of the ascending portion 23 near the lower end are exposed to the outside of the inner case 30. The portion of the descending portion 21 near the lower end, the lower surface of the side row portion 22, and the portion of the ascending portion 23 near the lower end project downward from the lower surface of the lower wall 33 of the inner case 30.

The portion of the bus bar 20 protruding below the lower surface of the lower wall 33 of the inner case 30 is covered with the heat transfer member 49. The portion of the descending portion 21 near the lower end, the lower surface of the side row portion 22, and the portion of the ascending portion 23 near the lower end are in heat transfer contact with the heat transfer member 49. Heat transfer contact means that the portion of the descending portion 21 near the lower end, the lower surface of the side row portion 22, and the portion of the ascending portion 23 near the lower end are in close contact with the heat transfer member 49. In addition to including the case of partial contact.

The lower end of the pressing portion 35 extending from the upper wall 31 of the inner case 30 is in contact with the upper surface of the lateral portion 22 of the bus bar 20 from above. As a result, the side portion 22 of the bus bar 20 is pressed from above the heat transfer member 49.

Of the resin layer 26 formed on the bus bar 20, the portion of the heat transfer member 49 that is not in heat transfer contact is referred to as a heat radiating portion 27 that radiates heat to the members arranged around the bus bar 20. Examples of the member arranged around the bus bar 20 include an inner case 30 and a case 40 capable of radiating heat through the through window portion 34. Further, although not shown in detail, electronic parts and the like arranged in the inner case 30 are also exemplified as members arranged around the bus bar 20.

The relay 14 switches the electrical connection state of the power storage module 12 by switching the energization of the exciting coil of the relay body and its stop. The switching of such a relay 14 is controlled by a control device (not shown).

[Action and effect of the embodiment]
Subsequently, the action and effect of this embodiment will be described. The electricity storage pack 2 according to the present embodiment generates heat when energized, and is connected to a relay 14 having a terminal 15, a metal bus bar 20 having an insulating resin layer 26 on the surface thereof, and a bus bar. Of the 20, the heat transfer member 49, which is in contact with the portion where the resin layer 26 is formed and heat is transferred from the bus bar 20 via the resin layer 26, and the heat transfer member 49 are in contact with heat from the heat transfer member 49. A metal case lower member 41 to which the bus is transmitted is provided.

The heat generated by the relay 14 when energized is transferred from the terminal 15 to the bus bar 20. The heat transferred to the bus bar 20 is transferred to the heat transfer member 49 via the resin layer 26. The heat transferred to the heat transfer member 49 is transferred to the case lower member 41. As a result, heat is trapped in the relay 14 and the relay 14 is prevented from becoming locally hot.

The metal bus bar 20 and the metal case lower member 41 are electrically insulated by the resin layer 26.

According to this embodiment, the heat transfer member 49 is made of an insulating material.

Since the bus bar 20 and the case lower member 41 are electrically insulated by the resin layer 26 on the surface of the bus bar 20 and the insulating heat transfer member 49, between the bus bar 20 and the case lower member 41. Insulation can be further improved.

According to the present embodiment, the resin layer 26 has a heat radiating portion 27 that does not come into contact with the heat transfer member 49, and the resin layer 26 has higher heat radiating performance than the metal constituting the bus bar 20.

The resin layer 26 can efficiently radiate heat from the heat radiating portion 27, which does not come into contact with the heat transfer member 49, to the parts located in the vicinity of the bus bar 20.

According to the present embodiment, the bus bars 20 are arranged at intervals from the relay 14 in the case 40.

Since there is a gap between the relay 14 and the bus bar 20, the heat generated from the relay 14 is efficiently dissipated into the case 40. This improves the heat dissipation of the relay 14.

According to the present embodiment, the inner case 30 is arranged inside the case 40, the relay 14 and the bus bar 20 are housed in the inner case 30, and the inner case 30 penetrates the inner case 30. A through window portion 34 is formed.

The heat generated from the relay 14 and the bus bar 20 is dissipated to the outside of the inner case 30 through the through window portion 34.

According to the present embodiment, the inner case 30 has an opening 36 that opens to the wall portion on the heat transfer member 49 side, and the bus bar 20 is led out from the opening 36 to the outside of the inner case 30 to transfer heat. The member 49 is in contact with the case lower member 41 of the case 40.

Heat is transferred to the bus bar 20, the resin layer 26, the heat transfer member 49, and the case 40 through the opening 36. As a result, it is possible to prevent the inside of the inner case 30 from becoming locally hot.

According to the present embodiment, in the bus bar 20, the portion of the bus bar 20 that protrudes downward from the opening 36 and is closer to the lower end of the descending portion 21, the side portion 22, and the portion of the ascending portion 23 that is closer to the lower end are heat transfer members. Covered by 49. This makes it possible to prevent the bus bar 20 from being damaged. Such a configuration is effective when a process of transferring the electric connection box 13 to a different place and assembling it to the case 40 after manufacturing the electric connection box 13 is adopted.

According to this embodiment, the heat transfer member 49 is an elastic sheet.

Since the heat transfer member 49 is an elastic sheet, the heat transfer member 49 can be sandwiched between the resin layer 26 and the case 40 in a compressed state. As a result, the heat transfer member 49 can come into contact with the resin layer 26 and the case 40 with a high degree of adhesion, and the heat of the bus bar 20 can be efficiently transferred from the resin layer 26 to the case 40.

<Other embodiments>
(1) In the first embodiment, the relay 14 is exemplified as the heat generating component, but the present invention is not limited to this, and a semiconductor switching element may be used.

(2) The storage pack 2 according to the first embodiment may be configured not to have the inner case 30.

(3) In the first embodiment, the upper wall 31 of the inner case 30 is configured to have the through window portion 34, but the present invention is not limited to this, and the upper wall 31 may be configured not to have the through window portion 34.

(4) In the first embodiment, a part of the bus bar 20 is located inside the opening 36 of the inner case 30, but the bus bar 20 is not limited to this, and the bus bar 20 is from the upper surface of the lower wall 33 of the inner case 30. May also be located above. In this case, the bus bar 20 is located above the opening 36.

(5) In the first embodiment, the heat transfer member 49 is formed of a material having an insulating property, but the heat transfer member 49 is not limited to this, and the heat transfer member 49 is formed of a material having a conductive property. May be good.

1: Vehicle 2: Storage pack 3: PCU
4: Wire harness 12: Power storage module 13: Electric connection box 14: Relay 15: Terminal 16: Relay case 20: Bus bar 21: Descending part 22: Side line part 23: Ascending part 24: External connection part 25: Connection end part 26 : Resin layer 27: Heat radiation part 30: Inner case 31: Upper wall 32: Side wall 33: Lower wall 34: Through window part 35: Pressing part 36: Opening part 37: Leg part 39: Mounting part 40: Case 41: Case Lower member 42: Bottom plate 43: Outer wall 49: Heat transfer member 50:

Gap

60, 61, 62 Bolts

Claims

Heat-generating parts that generate heat when energized and have terminals,
A metal bus bar that is connected to the terminal and has an insulating resin layer on the surface.
A heat transfer member that comes into contact with a portion of the bus bar on which the resin layer is formed and heat is transferred from the bus bar via the resin layer.
A case where the portion that comes into contact with the heat transfer member and transfers heat from the heat transfer member is made of metal, and
Circuit configuration with.
The circuit configuration according to claim 1, wherein the heat transfer member is made of an insulating material.
The resin layer has a heat radiating portion that does not come into contact with the heat transfer member.
The circuit configuration according to claim 1 or 2, wherein the resin layer has higher heat radiation performance than the metal constituting the bus bar.
The circuit configuration according to any one of claims 1 to 3, wherein the bus bar is arranged at a distance from the heat generating component in the case.
An inner case is arranged inside the case,
The heat generating component and the bus bar are housed in the inner case.
The circuit configuration according to any one of claims 1 to 4, wherein a through window portion penetrating the inner case is formed in the inner case.
The inner case has an opening that opens into the wall portion on the heat transfer member side.
The circuit configuration according to claim 5, wherein the bus bar or the heat transfer member is led out from the opening to the outside of the inner case, and the heat transfer member is in contact with the case.
The circuit configuration according to any one of claims 1 to 6, wherein the heat transfer member is made of an elastic sheet.