JP7773706B2 - Electrical Equipment - Google Patents

Description

This disclosure relates to electrical equipment.

Electrical equipment installed in vehicles such as electric vehicles and hybrid vehicles includes components that easily generate heat, such as relays, and is equipped with a structure for dissipating heat from these components. A known example of such electrical equipment is the circuit assembly described in Japanese Patent Laid-Open No. 2020-88087 (Patent Document 1 below). The circuit assembly described in Patent Document 1 includes a main relay as a heat-generating component, a first bus bar, a base member on which the main relay and first bus bar are disposed, an insulating plate superimposed on the underside of the base member, and a metal heat dissipation plate superimposed on the underside of the insulating plate. The first bus bar includes a first electrical connection portion electrically connected to the main relay, a first thermally conductive connection portion, and a first bypass portion connecting the first electrical connection portion and the first thermally conductive connection portion. The first thermally conductive connection portion contacts the insulating plate through a first through-hole provided in the base member. This thermally conductive connection portion is thermally connected to the heat dissipation member via the insulating plate. By providing the first detour portion, the first thermally conductive connection portion can be provided at a position separated from the main relay, thereby enabling heat from the main relay to be dissipated.

Japanese Patent Application Laid-Open No. 2020-88087

In the above configuration, an insulating plate is provided to prevent the bus bar from conducting to the heat dissipation member. Furthermore, to prevent the top surface of the bus bar from being exposed to the outside, a separate upper case or similar must be provided to cover the bus bar from above. In this way, a structure for insulating the bus bar must be provided in the circuit structure, which tends to increase the number of components.

In addition, in the above configuration, the first bus bar is provided with a first thermally conductive connection portion and a first bypass portion to dissipate heat from the main relay. This raises concerns that the first bus bar may become larger.

The electrical device disclosed herein comprises a heat-generating component, a bus bar connected to the heat-generating component, and a holding member that holds the heat-generating component and the bus bar, wherein the bus bar comprises a conductor portion and an insulating member that has a higher emissivity than the conductor portion and covers at least a portion of the outer surface of the conductor portion.

This disclosure enables electrical equipment to reduce the number of components used to insulate bus bars, and also enables heat-generating components to be dissipated while preventing the bus bars from becoming larger.

FIG. 1 is a plan view of an electrical device according to a first embodiment. FIG. 2 is a bottom view of the electrical device. FIG. 3 is a perspective view of an electrical device mounted in a metal housing. FIG. 4 is a perspective view of the electrical device attached to the metal housing, with the holding member omitted. FIG. 5 is a schematic diagram of the circuit configuration of the electrical device. FIG. 6 is a perspective view of the holding member. FIG. 7 is a perspective view of the first bus bar. FIG. 8 is a perspective view of the first bus bar as viewed from a different direction than that of FIG. FIG. 9 is a perspective view of the second bus bar. FIG. 10 is a cross-sectional view taken along line AA in FIG. FIG. 11 is a perspective view of the fifth bus bar. FIG. 12 is a cross-sectional view taken along the line BB in FIG. FIG. 13 is a perspective view of the sixth bus bar. FIG. 14 is a diagram showing the connection between the sixth bus bar and the precharge resistor. FIG. 15 is a perspective view of the eighth bus bar. FIG. 16 is a perspective view showing the arrangement of the eighth bus bar and the ninth bus bar. FIG. 17 is an explanatory diagram showing a manufacturing process of the first bus bar. FIG. 18 is a plan view of the electrical device according to the second embodiment. FIG. 19 is a bottom view of the electrical device. FIG. 20 is a cross-sectional view taken along the line CC in FIG. FIG. 21 is a perspective view of an electrical device attached to a metal housing. FIG. 22 is a perspective view of an electrical device attached to a metal housing, with the holding member omitted.

Description of the embodiments of the present disclosure
First, embodiments of the present disclosure will be listed and described.
[1] The electrical device of the present disclosure includes a heat-generating component, a bus bar connected to the heat-generating component, and a holding member that holds the heat-generating component and the bus bar, wherein the bus bar includes a conductor portion and an insulating member that has a higher emissivity than the conductor portion and covers at least a portion of an outer surface of the conductor portion.

With this configuration, at least a portion of the outer surface of the conductor portion of the busbar is covered with an insulating material, making it easier to ensure insulation of the busbar from the outside. Furthermore, because the insulating material has a higher emissivity than the conductor portion, heat transferred from the heat-generating component to the busbar is more easily dissipated to the outside by radiation. In other words, heat is more easily dissipated from the heat-generating component. Therefore, heat can be dissipated from the heat-generating component without the need to make the busbar large.

[2] In the above [1], it is preferable that a portion of the busbar is exposed to the outside.

With this configuration, it is possible to eliminate the need for components to cover the busbar from the outside.

[3] It is preferable that the electrical device of [1] or [2] above is an electrical device mounted in a metal housing, and that a portion of the bus bar is in contact with the metal housing.

This configuration makes it easier to dissipate heat transferred from heat-generating components to the busbar.

[Details of the embodiment of the present disclosure]
The following describes embodiments of the present disclosure. The present disclosure is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims. In the drawings, for the sake of convenience, some components may be exaggerated or simplified. Furthermore, the dimensional ratios of the components may differ between drawings. In this specification, "orthogonal" does not only refer to a strict orthogonal relationship, but also includes a roughly orthogonal relationship within the scope of the operation and effect of the present embodiment.

<Embodiment 1>
A first embodiment of the present disclosure will be described with reference to FIGS. 1 to 17 . An electrical device 1 of this embodiment is mounted on a vehicle such as an electric vehicle or a hybrid vehicle, and is disposed in a power supply path connecting a power source such as a battery and a load such as a motor. The electrical device 1 can be disposed in any orientation, but in the following description, the direction indicated by arrow Z will be described as upward, the direction indicated by arrow X as forward, and the direction indicated by arrow Y as leftward. Note that, for multiple identical components, only some of the components will be designated by reference numerals, and the reference numerals for the other components may be omitted.

(Electrical equipment 1)
1 and 3 , the electrical device 1 includes a main relay 2 (an example of a heat-generating component), a pre-charge relay 3 (an example of a heat-generating component), a pre-charge resistor 4 (an example of a heat-generating component), a plurality of bus bars 20, and a holding member 10. The holding member 10 holds the main relay 2, the pre-charge relay 3, the pre-charge resistor 4, and the plurality of bus bars 20. As shown in Fig. 4 , the plurality of bus bars 20 include a first bus bar 21, a second bus bar 22, a third bus bar 23, a fourth bus bar 24, a fifth bus bar 25, a sixth bus bar 26, a seventh bus bar 27, an eighth bus bar 28, and a ninth bus bar 29.

(Holding member 10)
The holding member 10 is made of insulating synthetic resin. As shown in FIG. 6 , the holding member 10 has an overall shape that is flat in the vertical direction. A main relay housing 11 is formed in the left-right center of the holding member 10. The main relay housing 11 is generally frame-shaped. Nut attachment portions 11A, on which nuts N1 (see FIG. 4 ) are disposed, are formed in the front right corner and the rear left corner of the main relay housing 11. As shown in FIG. 1 , the main relay 2 is housed in the main relay housing 11. A mounting bolt B1 is inserted into a mounting hole in a mounting piece 2C provided on the main relay 2 and fastened to the nut N1 (see FIG. 4 ) of the nut attachment portion 11A of the main relay housing 11, thereby fixing the main relay 2 to the main relay housing 11.

As shown in FIG. 6, the holding member 10 has a precharge relay housing 12. The precharge relay housing 12 is disposed in front of the main relay housing 11. The precharge relay housing 12 is generally frame-shaped. A flexible lock receiving portion 12A is formed on the side wall of the precharge relay housing 12. A first insertion hole 12B and a second insertion hole 12C are formed on the bottom of the precharge relay housing 12. As shown in FIG. 3, the precharge relay 3 is housed in the precharge relay housing 12, and the lock receiving portion 12A is adapted to engage with the lock portion 3D of the precharge relay 3. As shown in FIG. 12, the first terminal portion 3B of the precharge relay 3 is inserted into the first insertion hole 12B. Although not shown in detail, the second terminal portion 3C of the precharge relay 3 is inserted into the second insertion hole 12C.

As shown in Figure 6, the holding member 10 has a connector fitting portion 13. The connector fitting portion 13 is arranged in front of the precharge relay accommodating portion 12. The connector fitting portion 13 is generally cylindrical with a bottom. A terminal hole 13A is formed at the bottom of the connector fitting portion 13. As shown in Figure 3, the connector 5 is adapted to fit into the connector fitting portion 13. Although not shown in detail, the end of the eighth bus bar 28 and the end of the ninth bus bar 29 are inserted into the terminal hole 13A.

As shown in FIG. 6, the holding member 10 has a pre-charge resistor housing 14. The pre-charge resistor housing 14 is arranged to the left of the main relay housing 11 and the pre-charge relay housing 12. The pre-charge resistor housing 14 is long in the front-to-rear direction and is generally frame-shaped. Deformable locking portions 14A are formed on the front and rear walls of the pre-charge resistor housing 14. A third insertion hole 14B is formed in the bottom of the pre-charge resistor housing 14. As shown in FIG. 3, the pre-charge resistor 4 is housed in the pre-charge resistor housing 14, and the locking portion 14A is adapted to lock onto the main body 4A of the pre-charge resistor 4. Although not shown in detail, the terminal portion 4B of the pre-charge resistor 4 is inserted into the third insertion hole 14B.

As shown in Figure 6, busbar engagement holes 15A, 15B are formed at both the left and right ends of the holding member 10. As shown in Figure 3, the second busbar 22 is inserted into the left busbar engagement hole 15A. The fourth busbar 24 is inserted into the right busbar engagement hole 15B. The busbar engagement holes 15A, 15B position the second busbar 22 and the fourth busbar 24 relative to the holding member 10. As shown in Figure 6, the holding member 10 has a nut mounting portion 16 recessed from the top surface. The nut mounting portion 16 is located to the right of the busbar engagement hole 15A and to the left of the busbar engagement hole 15B. As shown in Figure 10, a nut N2 is disposed in the nut mounting portion 16.

As shown in FIG. 6, the holding member 10 includes mounting posts 17A, 17B, 17C, and 17D extending upward from the top surface of the holding member 10. Mounting post 17B is disposed between the pre-charge resistor housing 14 and the nut mounting portion 16 located on the left side in the left-right direction. Mounting post 17A is disposed in front of mounting post 17B. Mounting post 17C is disposed between the main relay housing 11 and the nut mounting portion 16 located on the right side in the left-right direction. Mounting post 17D is disposed behind mounting post 17C. Mounting posts 17A, 17B, 17C, and 17D respectively have nut mounting portions 17A1, 17B1, 17C1, and 17D1 on which nut N3 (see FIG. 10) is disposed. Busbar insertion holes 18 are formed near the base ends of mounting posts 17A and 17D on the holding member 10.

(Main relay 2)
The main relay 2 is a mechanical relay having a contact portion and a coil portion therein. As shown in FIG. 1 , the main relay 2 has a rectangular parallelepiped main body 2A, a terminal portion (not shown) and a partition wall 2B disposed on the rear surface of the main body 2A, a mounting piece 2C protruding from the main body 2A, and a connector fitting portion 2D (see FIG. 4 ) disposed on the left surface of the main body 2A. The terminal portion of the main relay 2 is nut-shaped and fastened to a bolt B2. The partition wall 2B is disposed between the two terminal portions. The partition wall 2B determines the creepage distance between the two terminal portions. The mounting piece 2C has a mounting hole (not shown) through which a mounting bolt B1 is inserted. The main relay 2 is turned on and off by a signal transmitted from an external device via a connector (not shown) fitted to the connector fitting portion 2D.

(Precharge relay 3, precharge resistor 4)
The precharge relay 3 is a mechanical relay smaller than the main relay 2 and has a contact portion and a coil portion therein. The precharge relay 3 has a rectangular parallelepiped main body 3A, a first terminal portion 3B (see FIG. 12) and a second terminal portion 3C (see FIG. 16) protruding from the bottom surface of the main body 3A, and a lock portion 3D (see FIG. 4) protruding from the main body 3A. Here, the first terminal portion 3B and the second terminal portion 3C are examples of terminal portions. As shown in FIG. 4, the precharge resistor 4 has a rectangular parallelepiped main body 4A and a terminal portion 4B protruding from the bottom surface of the main body 4A. The precharge relay 3 and the precharge resistor 4 are components of a precharge circuit.

Figure 5 is a schematic diagram of the circuit configuration of the electrical device 1, showing the electrical connections between each component and each bus bar 20. The precharge circuit is connected in parallel to the main relay 2. The precharge relay 3 is turned on and off by a signal transmitted from the outside via the connector 5 (see Figure 3) mated to the connector mating portion 13. The second terminal portion 3C is connected to this connector 5 via the eighth bus bar 28 and the ninth bus bar 29 (see Figure 16). After the precharge relay 3 is turned on, the main relay 2 is turned on, thereby suppressing the flow of inrush current through the main relay 2.

(Bus bar 20)
Each of the multiple bus bars 20 has the following common feature: As shown in Fig. 4 , each bus bar 20 is connected directly to components that generate heat when energized (main relay 2, pre-charge relay 3, pre-charge resistor 4) or indirectly via another bus bar 20. This allows heat to be transferred from the heat-generating components to each bus bar 20.

Each bus bar 20 comprises a conductor portion CP and an insulating member NP that covers at least a portion of the outer surface of the conductor portion CP (see, for example, the first bus bar 21 in Figure 7). The insulating member NP has a thickness (e.g., several tens of μm) that ensures insulation from the conductor portion CP connected to a battery, etc., even when in contact with the surface of the insulating member NP. In the drawings, the insulating member NP corresponds to the shaded area. The conductor portion CP is made of a metal such as copper, copper alloy, aluminum, or aluminum alloy, and is plate-shaped. The insulating member NP has a higher emissivity than the conductor portion CP. For example, an insulating resin material such as polyimide, fluororesin, or epoxy resin can be used as the insulating member NP.

It is preferable that the insulating member NP covers the portion of the outer surface of the conductor portion CP that is not hidden by other members (such as the holding member 10). This prevents contact with the conductor portion CP from the outside.

Each busbar 20 is short in the short-side direction and has a shape that is bent at at least one point. The bent edges BE of each busbar 20 extend in the short-side direction. The above are the common features of multiple busbars 20, and the configuration of each busbar 20 will be described in detail below. In the following description, the conductor portions CP, insulating members NP, and bent edges BE are given the same reference numerals. However, the shape of the conductor portions CP, the area where the insulating members NP are formed relative to the conductor portions CP, the number of bent edges BE, etc. may differ between busbars 20.

(First bus bar 21)
As shown in Fig. 1, the first bus bar 21 is generally L-shaped in a plan view. As shown in Figs. 7 and 8, the first bus bar 21 includes a first portion 21A and a second portion 21B bent relative to the first portion 21A. The first portion 21A extends in the left-right direction. The second portion 21B extends in the front-rear direction. A bent edge BE is formed between the left end of the first portion 21A and the rear end of the second portion 21B. The bent edge BE of the first bus bar 21 extends in the direction of the short side of the first bus bar 21 (the up-down direction).

As shown in FIG. 7, the outer surface of the conductor portion CP of the first bus bar 21 is covered with an insulating member NP, except for two cut surfaces 21C and 21D and three connection portions 21E, 21F, and 21G. In other words, the conductor portion CP is exposed to the outside at cut surfaces 21C and 21D and connection portions 21E, 21F, and 21G. Cut surfaces 21C and 21D are located on the right end surface of the first portion 21A and the front end surface of the second portion 21B, respectively. As shown in FIG. 1, cut surface 21C is located adjacent to and facing partition wall 2B of the main relay 2. Cut surface 21D is accommodated in groove portion 17A2 provided in mounting post 17A of holding member 10. This prevents contact with cut surfaces 21C and 21D from the outside.

As shown in FIG. 7, the first portion 21A has a connection portion 21E at its right end. The connection portion 21E has a through hole 21E1 that penetrates the conductor portion CP in the front-to-rear direction, and a connection surface 21E2 formed on the edge of the through hole 21E1. Although not shown in detail, a bolt B2 (see FIG. 1) is inserted into the through hole 21E1 and fastened to the terminal portion of the main relay 2, bringing the connection surface 21E2 into contact with the terminal portion of the main relay 2. This electrically connects the main relay 2 and the first bus bar 21. The bolt B2 is configured similarly to the bolt B3, which will be described later.

As shown in Figure 7, the second portion 21B has a connection portion 21F in its front-to-rear center. The connection portion 21F is the portion that connects to the second bus bar 22, which will be described later. The connection portion 21F has a through hole 21F1 that passes through the conductor portion CP in the left-right direction, and a connection surface 21F2 formed on the edge of the through hole 21F1. The right connection surface 21F2 provided on the connection portion 21F has a rectangular shape that matches the size of the second bus bar 22, which will be described later.

The second portion 21B has a connection portion 21G at its front end. The connection portion 21G is the portion that connects to the fifth bus bar 25, which will be described later. The connection portion 21G is configured substantially the same as the connection portion 21F, and has a through hole 21G1 and a connection surface 21G2. The right connection surface 21G2 provided on the connection portion 21G has a rectangular shape that matches the size of the fifth bus bar 25.

(Second bus bar 22)
As shown in Fig. 10 , the second bus bar 22 has a crank shape when viewed from the front-rear direction. As shown in Fig. 9 , the second bus bar 22 includes a first portion 22A, a second portion 22B bent relative to the first portion 22A, and a third portion 22C bent relative to the second portion 22B. The first portion 22A extends in the up-down direction. The second portion 22B extends in the left-right direction. The third portion 22C extends in the up-down direction. The bent edge BE of the second bus bar 22 includes a first bent edge BE1 and a second bent edge BE2. The first bent edge BE1 is formed between the lower end of the first portion 22A and the right end of the second portion 22B. The second bent edge BE2 is formed between the left end of the second portion 22B and the upper end of the third portion 22C. The bent edges BE (first bent edge BE1 and second bent edge BE2) of the second bus bar 22 extend in the short side direction (front-rear direction) of the second bus bar 22.

The outer surface of the conductor portion CP of the second bus bar 22 is covered with an insulating member NP, except for two cut surfaces 22D, 22E and two connection portions 22F, 22G. In other words, the conductor portion CP is exposed to the outside at cut surfaces 22D, 22E and connection portions 22F, 22G. Cut surfaces 22D, 22E are located on the upper end surface of the first portion 22A and the lower end surface of the third portion 22C, respectively. As shown in FIG. 10 , the third portion 22C is inserted into the bus bar engagement hole 15A of the holding member 10. As a result, cut surface 22E of the lower end surface of the third portion 22C is located inside the bus bar engagement hole 15A. Furthermore, the first portion 22A is connected to the first bus bar 21, and cut surface 22D of the upper end surface of the first portion 22A is located below the upper end surface of the first bus bar 21 and the upper end of the mounting post 17B. In this way, the cut surfaces 22D and 22E are arranged at positions that make it difficult to contact them from the outside.

As shown in FIG. 9, the first portion 22A has a connection portion 22F. The connection portion 22F has a through hole 22F1 that penetrates the conductor portion CP in the left-right direction, and a connection surface 22F2 formed on the edge of the through hole 22F1. As shown in FIG. 10, a bolt B3 is inserted through the through hole 22F1 and the through hole 21F1 of the first bus bar 21, and the bolt B3 is fastened to a nut N3 of the nut mounting portion 17B1 of the mounting column 17B, thereby bringing the connection surface 22F2 into contact with the connection surface 21F2 of the first bus bar 21. This electrically connects the second bus bar 22 and the first bus bar 21.

Bolt B3 has a head large enough to conceal connection surface 21F2 (see Figure 8) that comes into contact with bolt B3. The head is the portion formed at the end of the shank that is inserted into through holes 21F1 and 22F1 and that expands in diameter from the shank. Bolt B3 has a head with at least an insulated surface. For example, the portion of bolt B3 other than the surface of the head may be made of metal. Alternatively, bolt B3 may be entirely made of insulating resin. This prevents electrical connection with conductor portions CP of first bus bar 21 and second bus bar 22 when the head of bolt B3 is contacted from the outside.

As shown in FIG. 9, the second portion 22B has a connection portion 22G. The connection portion 22G has a through hole 22G1 that passes through the conductor portion CP in the vertical direction and a connection surface 22G2 formed on the edge of the through hole 22G1. The connection portion 22G is connected to a first external connection bus bar (not shown). The first external connection bus bar is electrically connected to a load, such as a motor. As shown in FIG. 10, a bolt (not shown) is inserted through the through hole 22G1 and the through hole of the first external connection bus bar (not shown). The bolt is then tightened into the nut N2 of the nut mounting portion 16, bringing the connection surface 22G2 into contact with the first external connection bus bar. This electrically connects the second bus bar 22 and the first external connection bus bar.

(Third bus bar 23)
1, the third bus bar 23 is generally L-shaped in a plan view and is configured in a manner similar to that of the first bus bar 21. A bent edge BE of the third bus bar 23 extends in the direction of the short side (vertical direction) of the third bus bar 23. Although not shown in detail, the third bus bar 23 includes a connection portion connected to a terminal portion of the main relay 2, a connection portion connected to the fourth bus bar 24, and a connection portion connected to the seventh bus bar 27 (see FIG. 4).

(Fourth bus bar 24)
4 , the fourth bus bar 24 is crank-shaped when viewed from the front-rear direction and is configured substantially similarly to the second bus bar 22. The bent edge BE of the fourth bus bar 24 includes a first bent edge BE1 and a second bent edge BE2 and extends in the direction of the short side of the fourth bus bar 24 (front-rear direction). The fourth bus bar 24 has a connection portion (not shown) connected to the third bus bar 23 and a connection portion 24A connected to a second external connection bus bar (not shown). This second external connection bus bar is electrically connected to a power source such as a battery.

(Fifth bus bar 25)
As shown in FIG. 11 , the fifth bus bar 25 has a generally angular U-shape when viewed from the front-to-rear direction. The fifth bus bar 25 includes a first portion 25A, a second portion 25B bent relative to the first portion 25A, and a third portion 25C bent relative to the second portion 25B. The first portion 25A extends in the vertical direction. The second portion 25B extends in the horizontal direction. The third portion 25C extends in the vertical direction. The bent edge BE of the fifth bus bar 25 includes a first bent edge BE1 and a second bent edge BE2. The first bent edge BE1 is formed between the lower end of the first portion 25A and the right end of the second portion 25B. The second bent edge BE2 is formed between the left end of the second portion 25B and the lower end of the third portion 25C. The bent edges BE (first bent edge BE1 and second bent edge BE2) of the fifth bus bar 25 extend in the short side direction (front-rear direction) of the fifth bus bar 25.

The outer surface of the conductor portion CP of the fifth bus bar 25 is covered with an insulating member NP, except for one cut surface 25D and two connection portions 25E and 25F. In other words, the conductor portion CP is exposed to the outside at cut surface 25D and connection portions 25E and 25F. Cut surface 25D is located on the upper end surface of the third portion 25C. The third portion 25C is connected to the first bus bar 21. Although not shown in detail, cut surface 25D is located below the upper end surface of the first bus bar 21 and the upper end of the mounting post 17A. In this way, cut surface 25D is located in a position that makes it difficult to contact from the outside. The first portion 25A has a tab-shaped connection portion 25E at its upper end. The conductor portion CP is exposed on the entire outer surface of connection portion 25E. Connection portion 25E is electrically connected to the first terminal portion 3B of the precharge relay 3 via an intermediate terminal 30, described below.

(Intermediate terminal 30)
As shown in FIG. 12 , the intermediate terminal 30 includes a connecting tubular portion 31 (see FIG. 4 ), a first contact portion 32, and a second contact portion 33. The connecting tubular portion 31 is rectangular and open at the top and bottom. The first contact portion 32 and the second contact portion 33 are disposed inside the connecting tubular portion 31. The first contact portion 32 is an elastic piece that extends obliquely downward from the upper end of the right wall portion of the connecting tubular portion 31. The second contact portion 33 is an elastic piece that extends obliquely upward from the lower end of the first contact portion 32. The second contact portion 33 is disposed between the first contact portion 32 and the right wall portion of the connecting tubular portion 31.

The first terminal portion 3B of the precharge relay 3 is inserted into the connecting tube portion 31 from above and comes into contact with the first contact portion 32. The connecting portion 25E of the fifth bus bar 25 is inserted into the connecting tube portion 31 from below and comes into contact with the second contact portion 33. This electrically connects the first terminal portion 3B of the precharge relay 3 and the fifth bus bar 25.

As shown in FIG. 11, the connection portion 25F of the third portion 25C has a through hole 25F1 that passes through the conductor portion CP in the left-right direction and a connection surface 25F2 formed on the edge of the through hole 25F1. The left connection surface 25F2 provided on the connection portion 25F has a rectangular shape that matches the size of the first bus bar 21. The third portion 25C is inserted into the bus bar insertion hole 18 (see FIG. 6) of the holding member 10 and is positioned so as to overlap the first bus bar 21. The fifth bus bar 25 and the first bus bar 21 are electrically connected in a manner similar to the connection between the second bus bar 22 and the first bus bar 21 (see FIG. 10). That is, bolt B4 (see FIG. 1) is inserted through through hole 25F1 and through hole 21G1 of first bus bar 21, and this bolt B4 is fastened to nut N3 of nut attachment portion 17A1 of mounting post 17A, thereby bringing connection surface 25F2 into contact with connection surface 21G2 of first bus bar 21. Bolt B4 has the same configuration as bolt B3 described above.

(Sixth bus bar 26)
As shown in FIG. 13 , the sixth bus bar 26 has a generally angular U-shape when viewed from the front-to-rear direction. The sixth bus bar 26 includes a first portion 26A, a second portion 26B bent relative to the first portion 26A, and a third portion 26C bent relative to the second portion 26B. The first portion 26A extends in the vertical direction. The second portion 26B extends in the horizontal direction. The third portion 26C extends in the vertical direction. The bent edge BE of the sixth bus bar 26 includes a first bent edge BE1 and a second bent edge BE2. The first bent edge BE1 is formed between the lower end of the first portion 26A and the right end of the second portion 26B. The second bent edge BE2 is formed between the left end of the second portion 26B and the lower end of the third portion 26C. The bent edges BE (first bent edge BE1 and second bent edge BE2) of the sixth bus bar 26 extend in the short side direction (front-rear direction) of the sixth bus bar 26.

The outer surface of the conductor portion CP of the sixth bus bar 26 is covered with insulating material NP, except for the cut surface 26D and the connection portion 26E. In other words, the conductor portion CP is exposed to the outside at the cut surface 26D and the connection portion 26E. The cut surface 26D includes the end surface of the tuning fork terminal 40, which will be described below. The first portion 26A has a tab-shaped connection portion 26E at its upper end. The conductor portion CP is exposed over the entire outer surface of the connection portion 26E. The connection portion 26E is electrically connected to the first terminal portion 3B of the pre-charge relay 3 via the intermediate terminal 30 (see Figure 4).

(Tuning fork terminal 40)
The third portion 26C includes a tuning fork terminal 40. The tuning fork terminal 40 is generally U-shaped when viewed from the left and right. The tuning fork terminal 40 includes a base 41 and a pair of clamping pieces 42 extending upward from the front and rear ends of the base 41. A protrusion 43 is formed at the tip (upper end) of each clamping piece 42. Each protrusion 43 protrudes from each clamping piece 42 in a direction that narrows the space between the pair of clamping pieces 42. The left and right surfaces of the tuning fork terminal 40 are covered with an insulating member NP. Meanwhile, the cut surface 26D created during the formation of the tuning fork terminal 40 is not covered with the insulating member NP, and the conductor portion CP is exposed. As a result, when the terminal portion 4B of the precharge resistor 4 is inserted between the pair of clamping pieces 42 of the tuning fork terminal 40, the terminal portion 4B of the precharge resistor 4 is clamped by the pair of protrusions 43, as shown in FIG. 14 . The cut surface 26D arranged on the protrusion 43 comes into contact with the terminal portion 4B of the pre-charge resistor 4. This electrically connects the sixth bus bar 26 and the pre-charge resistor 4. By providing the tuning fork terminal 40 in this manner, it is possible to easily connect the end of the sixth bus bar 26, whose plate thickness directions are perpendicular to each other, to the terminal portion 4B of the pre-charge resistor 4. Furthermore, because the cut surface 26D of the third portion 26C is arranged inside the holding member 10, it is possible to prevent external contact with the conductor portion CP of the sixth bus bar 26.

(7th bus bar 27)
4 , the seventh bus bar 27 has a generally angular U-shape when viewed from the front-to-rear direction. The bent edge BE of the seventh bus bar 27 includes a first bent edge BE1 and a second bent edge BE2, and extends in the direction of the short side (front-to-rear direction) of the seventh bus bar 27. The seventh bus bar 27 is configured generally similarly to the connection portion 25F of the fifth bus bar 25, and includes a connection portion (not shown) connected to the third bus bar 23 and a tuning fork terminal 40 connected to the terminal portion 4B of the pre-charge resistor 4.

(8th bus bar 28)
15 , the eighth bus bar 28 includes a first portion 28A, a second portion 28B bent relative to the first portion 28A, a third portion 28C bent relative to the second portion 28B, a fourth portion 28D bent relative to the third portion 28C, and a fifth portion 28E bent relative to the fourth portion 28D. The first portion 28A extends in the vertical direction. The second portion 28B extends in the front-rear direction. The third portion 28C extends in the vertical direction. The fourth portion 28D extends diagonally forward and upward from the third portion 28C. The fifth portion 28E extends in the vertical direction. The third portion 28C includes a wide portion 28C1 connected to the second portion 28B, and a narrow portion 28C2 extending upward from the wide portion 28C1 and formed narrower than the wide portion 28C1. The narrow portion 28C2 is disposed to the left of the center of the wide portion 28C1. The narrow portion 28C2 is connected to the fourth portion 28D. The fourth portion 28D and the fifth portion 28E are configured to have substantially the same width dimension (dimension in the left-right direction) as the narrow portion 28C2.

The bending edges BE of the eighth bus bar 28 include a first bending edge BE1, a second bending edge BE2, a third bending edge BE3, and a fourth bending edge BE4. The first bending edge BE1 is formed between the lower end of the first portion 28A and the rear end of the second portion 28B. The second bending edge BE2 is formed between the front end of the second portion 28B and the lower end of the third portion 28C (wide portion 28C1). The third bending edge BE3 is formed between the upper end of the third portion 28C (narrow portion 28C2) and the lower end of the fourth portion 28D. The fourth bending edge BE4 is formed between the upper end of the fourth portion 28D and the lower end of the fifth portion 28E. The bending edges BE (first bending edge BE1, second bending edge BE2, third bending edge BE3, and fourth bending edge BE4) of the eighth bus bar 28 extend in the short side direction (left-right direction) of the eighth bus bar 28.

The first portion 28A has a tuning fork terminal 40. The fifth portion 28E has a tab-shaped connection portion 28F at its upper end. The conductor portion CP is exposed on the entire outer surface of the connection portion 28F. As shown in Figure 16, the tuning fork terminal 40 is connected to the second terminal portion 3C of the precharge relay 3. The connection portion 28F is inserted into the terminal hole 13A of the connector fitting portion 13 of the holding member 10 and is disposed within the connector fitting portion 13 (see Figure 6). The connection portion 28F is connected to the connector 5 fitted into the connector fitting portion 13.

(9th bus bar 29)
The ninth bus bar 29 has a configuration substantially similar to the eighth bus bar 28. As shown in FIG. 4 , the ninth bus bar 29 includes a first portion 29A, a second portion 29B bent relative to the first portion 29A, and a third portion 29C bent relative to the second portion 29B. The first portion 29A extends in the vertical direction and includes a tuning fork terminal 40. The second portion 29B extends in the front-rear direction. The third portion 29C extends in the vertical direction. The bent edge BE of the ninth bus bar 29 includes only a first bent edge BE1 and a second bent edge BE2. The first bent edge BE1 is formed between the lower end of the first portion 29A and the rear end of the second portion 29B. The second bent edge BE2 is formed between the front end of the second portion 29B and the lower end of the third portion 29C.

As shown in FIG. 16, the second portion 29B is longer in the front-to-rear direction than the second portion 28B of the eighth bus bar 28. The third portion 29C comprises a wide portion 29C1 connected to the second portion 29B, and a narrow portion 29C2 extending upward from the wide portion 29C1 and formed narrower than the wide portion 29C1. The narrow portion 29C2 is located to the right of the center of the wide portion 29C1. A tab-shaped connection portion 29D is formed at the upper end of the narrow portion 29C2. The connection portion 29D is configured to be connected to the connector 5.

The second portion 28B of the eighth bus bar 28 is arranged overlapping the second portion 29B of the ninth bus bar 29. The connection portion 28F of the eighth bus bar 28 and the connection portion 29D of the ninth bus bar 29 are arranged side by side in the left-right direction. The cut surfaces 28G and 29E that appear as a result of the formation of the connection portions 28F and 29D, respectively, expose the conductor portion CP, but these cut surfaces 28G and 29E are arranged at a spatial distance that allows insulation from each other. By arranging the eighth bus bar 28 and the ninth bus bar 29 overlapping in this way, the installation space for the eighth bus bar 28 and the ninth bus bar 29 can be reduced.

In this embodiment, as shown in FIG. 3 , at least a portion of the first bus bar 21, the second bus bar 22, the third bus bar 23, and the fourth bus bar 24 is exposed to the outside on the upper surface of the holding member 10. Because the bus bar 20 includes the insulating member NP, the bus bar 20 is insulated from the outside even when a portion of the bus bar 20 is exposed to the outside in the electric device 1. Therefore, the electric device 1 does not need an insulating member to entirely cover the bus bar 20, thereby reducing the number of components in the electric device 1. Furthermore, because the bus bar 20 is not entirely covered in the electric device 1, heat buildup in the bus bar 20 within the electric device 1 can be alleviated. Furthermore, because the exposed portion of the bus bar 20 is covered with the insulating member NP, which has a higher emissivity than the conductor portion CP, heat from the bus bar 20 can be efficiently radiated to the outside. This improves the heat dissipation of the bus bar 20.

In this embodiment, the electrical device 1 is attached to a metal housing 6. Only a portion of the metal housing 6 where the electrical device 1 is installed is shown in the figure. The metal housing 6 may house a battery, for example. As shown in FIG. 2 , in the electrical device 1, the fifth bus bar 25, the sixth bus bar 26, the seventh bus bar 27, the eighth bus bar 28, and the ninth bus bar 29 are attached to the underside of the holding member 10. When the electrical device 1 is attached to the metal housing 6, the fifth bus bar 25, the sixth bus bar 26, the seventh bus bar 27, the eighth bus bar 28, and the ninth bus bar 29 are not exposed to the outside but contact the metal housing 6 inside the holding member 10 (see FIGS. 3 and 4 ). The eighth bus bar 28 is connected to the metal housing 6 via the ninth bus bar 29. The portions of these bus bars 20 that contact the metal housing 6 are insulating members NP, preventing electrical conduction between the bus bars 20 and the metal housing 6. When the bus bar 20 comes into contact with the metal housing 6, the heat of the bus bar 20 can be transferred to the metal housing 6. Therefore, the heat dissipation property of the bus bar 20 can be improved.

(Method for manufacturing electrical device 1)
The above is the configuration of the electric device 1. Below, we will explain an example of a method for manufacturing the electric device 1. The method for manufacturing the electric device 1 includes a process for manufacturing the busbar 20, a process for manufacturing the holding member 10, and a process for assembling each component.

(Busbar 20 Manufacturing Process)
An example of a manufacturing process for the busbar 20 will be described below with reference to FIG. 17 . Here, the manufacturing process (manufacturing method) for the first busbar 21 will be described as a representative of the busbar 20. First, a strip-shaped metal plate 50 extending in one direction is prepared (first process). This metal plate 50 will become the conductor portion CP of the busbar 20. The short-side direction of the metal plate 50 (the vertical direction in FIG. 17 ) corresponds to the short-side direction of the busbar 20.

Next, the outer surface of the metal plate 50 is coated with insulating material NP to obtain a coated plate 51 (step 2). Because the metal plate 50 is a strip extending in one direction, in step 2, an extruder can be used to form the insulating material NP on the outer surface of the metal plate 50. That is, the extruder can feed the metal plate 50 in its extension direction (long side direction) while adhering the insulating material NP to the outer surface of the metal plate 50. The short side direction of the metal plate 50 is perpendicular to the direction in which the extruder feeds the metal plate 50. Using an extruder can improve the work efficiency of step 2 and reduce the manufacturing costs of the busbar 20.

The covering plate material 51 is cut and holes are drilled to obtain the first molded body 52 (step 3). When manufacturing the first bus bar 21, the cutting line is straight, but the cutting line may be changed as appropriate depending on the shape of the bus bar 20 to be manufactured. For example, when manufacturing the sixth bus bar 26, the portion corresponding to the tuning fork terminal 40 is formed using a curved cutting line. Also, depending on the shape of the bus bar 20, drilling may not be required.

Next, a portion of the insulating member NP of the first molded body 52 (the portion surrounded by the dashed line) is removed to obtain the second molded body 53 (step 4). This forms the connection portions 21E, 21F, and 21G.

Finally, the second molded body 53 is bent at the bending line 54 indicated by the dashed dotted line to obtain the first bus bar 21 (see Figure 7) (step 5). In step 5, the second molded body 53 is bent so that the bending edge BE of the first bus bar 21 extends in the direction of the short side of the first bus bar 21. The bending line 54 corresponds to the bending edge BE. By specifying the direction of the bending line 54 in this manner, the bending process of the second molded body 53 becomes easier. Furthermore, the insulating member NP is less likely to be damaged at the bending edge BE. This completes the manufacturing of the first bus bar 21.

The retaining member 10 can be formed by injection molding or the like. As mentioned above, the retaining member 10 is formed with accommodation sections for each component and holes for engagement. The assembly process for each component is carried out by placing each component on the retaining member 10 and connecting them by bolting or the like. This completes the manufacturing of the electrical device 1.

(Effects of the First Embodiment)
(1) The electrical device 1 according to the first embodiment includes heat-generating components (a main relay 2, a precharge relay 3, and a precharge resistor 4), a bus bar 20 connected to the heat-generating components, and a holding member 10 that holds the heat-generating components and the bus bar 20. The bus bar 20 includes a conductor portion CP and an insulating member NP that has a higher emissivity than the conductor portion CP and covers at least a portion of the outer surface of the conductor portion CP.

With this configuration, at least a portion of the outer surface of the conductor portion CP of the busbar 20 is covered with the insulating member NP, making it easier to ensure insulation of the busbar 20 from the outside. Furthermore, because the insulating member NP has a higher emissivity than the conductor portion CP, heat transferred from heat-generating components to the busbar 20 can be more easily dissipated to the outside by radiation. In other words, heat-generating components can be more easily dissipated. Therefore, heat can be dissipated from heat-generating components without the need to make the busbar 20 large.

(2) In embodiment 1, a portion of the busbar 20 is exposed to the outside.

With this configuration, it is possible to omit the need for a member to cover the bus bar 20 from the outside.

(3) The electrical device 1 in embodiment 1 is an electrical device 1 that is attached to a metal housing 6, and a portion of the bus bar 20 is in contact with the metal housing 6.

This configuration makes it easier to dissipate heat transferred from heat-generating components to the bus bar 20.

<Embodiment 2>
A second embodiment of the present disclosure will be described with reference to Fig. 18 to Fig. 22. An electric device 101 according to the second embodiment is configured substantially similarly to the electric device 1 according to the first embodiment. Therefore, hereinafter, substantially the same components as those in the first embodiment will be denoted by the same reference numerals, and descriptions thereof may be omitted.

Each bus bar 20 in embodiment 2 may differ from each bus bar 20 in embodiment 1 in terms of the shape of the conductor portion CP, the area in which the insulating member NP is formed relative to the conductor portion CP, the number of bent edges BE, etc., but is configured in approximately the same way as each bus bar 20 in embodiment 1.

As shown in FIG. 19 , the holding member 110 according to the second embodiment differs from the holding member 10 according to the first embodiment in that it holds the main relay 2, the first bus bar 21, and the third bus bar 23 on the underside of the holding member 110. The main relay 2, the first bus bar 21, and the third bus bar 23 are disposed inside the holding member 110 and are not exposed to the outside (see FIGS. 21 and 22 ). As shown in FIGS. 18 and 21 , the precharge relay 3, the precharge resistor 4, the second bus bar 22, and the fourth bus bar 24 are held on the upper side of the holding member 110. As shown in FIGS. 20 and 22 , when the electrical device 101 is attached to the metal housing 6, the first bus bar 21 and the third bus bar 23 are in contact with the metal housing 6. Therefore, in the second embodiment, unlike the first embodiment, heat transfer from the first bus bar 21 and the third bus bar 23 to the metal housing 6 is possible.

As shown in Figure 20, the holding member 110 has a tool hole 119 that penetrates its right wall in the left-right direction. A tool (not shown) can be inserted into the tool hole 119 to bolt the connection portion of the first bus bar 21 to the terminal portion of the main relay 2 from the outside. As shown in Figure 19, the holding member 110 also has a tool hole 119 for bolting the connection portion of the third bus bar 23 to the terminal portion of the main relay 2.

The effects of embodiment 2 are substantially the same as those of embodiment 1, so explanation will be omitted.

(Other embodiments)
The above-described first and second embodiments can be modified as follows: The above-described first and second embodiments and the following modifications can be combined and implemented within the scope of technical compatibility.

- In the above embodiments 1 and 2, the main relay 2, precharge relay 3, and precharge resistor 4 are given as examples of heat-generating components, but the heat-generating components include any component that can generate heat when current is applied. Heat-generating components may be, for example, resistors, coils, capacitors, fuses, diodes, ICs (Integrated Circuits), switching elements such as FETs (Field Effect Transistors), etc.

- In the above embodiments 1 and 2, the electrical equipment 1, 101 was equipped with nine bus bars 20, but the electrical equipment only needs to be equipped with at least one bus bar.

- In the above-described first and second embodiments, the busbar 20 has a bent shape, but the shape of the busbar is not particularly limited. For example, the busbar does not have to be bent. Furthermore, if the busbar is bent, the direction in which the bent edge of the busbar extends may be set arbitrarily.

- In the above embodiment 1, in the manufacturing process of the busbar 20, an extruder was used to coat the outer surface of the conductor portion CP with the insulating material NP, but the insulating material may also be formed by, for example, electroplating or coating.

1: Electrical equipment 2: Main relay 2A: Main body 2B: Partition wall 2C: Mounting piece 2D: Connector fitting portion 3: Pre-charge relay 3A: Main body 3B: First terminal portion 3C: Second terminal portion 3D: Lock portion 4: Pre-charge resistor 4A: Main body 4B: Terminal portion 5: Connector 6: Metal housing 10: Holding member 11: Main relay accommodating portion 11A: Nut mounting portion 12: Pre-charge relay accommodating portion 12A: Lock receiving portion 12B: First insertion hole 12C: Second insertion hole 13: Connector fitting portion 13A: Terminal hole 14: Pre-charge resistor accommodating portion 14A: Locking portion 14B: Third insertion holes 15A, 15B : Busbar engagement hole 16: Nut mounting portions 17A, 17B, 17C, 17D: Mounting column 18: Busbar insertion hole 20: Busbar 21: First busbar 21A: First portion 21B: Second portions 21C, 21D: Cutting surface 21E: Connection portion 21E1: Through hole 21E2: Connection surface 21F: Connection portion 21F1: Through hole 21F2: Connection surface 21G: Connection portion 21G1: Through hole 21G2: Connection surface 22: Second busbar 22A: First portion 22B: Second portion 22C: Third portion 22D, 22E: Cutting surface 22F: Connection portion 22F1: Through hole 22F2: Connection surface 22G: Connection portion 22G1: Through hole 22G 2: Connection surface 23: Third bus bar 24: Fourth bus bar 24A: Connection portion 25: Fifth bus bar 25A: First portion 25B: Second portion 25C: Third portion 25D: Cut surface 25E: Connection portion 25F: Connection portion 25F1: Through hole 25F2: Connection surface 26: Sixth bus bar 26A: First portion 26B: Second portion 26C: Third portion 26D: Cut surface 26E: Connection portion 27: Seventh bus bar 28: Eighth bus bar 28A: First portion 28B: Second portion 28C: Third portion 28C1: Wide portion 28C2: Narrow portion 28D: Fourth portion 28E: Fifth portion 28F: Connection portion 28G: Cut surface 29: Ninth bus bar - 29A: First portion 29B: Second portion 29C: Third portion 29C1: Wide portion 29C2: Narrow portion 29D: Connection portion 29E: Cut surface 30: Intermediate terminal 31: Connection tube portion 32: First contact portion 33: Second contact portion 40: Tuning fork terminal 41: Base portion 42: Clamping piece 43: Protrusion portion 50: Metal plate material 51: Covering plate material 52: First molded body 53: Second molded body 54: Bending line 101: Electrical equipment B1: Mounting bolts B2, B3, B4: Bolt BE: Bending edge BE1: First bending edge BE2: Second bending edge BE3: Third bending edge BE4: Fourth bending edge CP: Conductor portions N1, N2, N3: Nut NP: Insulating member

Claims (3)

A heat-generating component;
a bus bar connected to the heat-generating component;
a holding member that holds the heat generating component and the bus bar,
the bus bar includes a conductor portion and an insulating member having a higher emissivity than the conductor portion and covering at least a portion of an outer surface of the conductor portion;
the bus bars include a first bus bar connected to the heat-generating component and a second bus bar connected to the first bus bar,
the first bus bar is L-shaped when viewed from a first direction, and the second bus bar has a first portion extending in the first direction and a second portion extending in a second direction perpendicular to the first direction and connected to an external connection bus bar. The electrical device according to claim 1 , wherein a portion of the bus bar is exposed to the outside. An electrical device that is attached to a metal housing,
The electrical device according to claim 1 , wherein a portion of the bus bar is in contact with the metal housing.