Busbar heat dissipation structure

Abstract

To provide a busbar heat dissipation structure that enables efficient dissipation of heat occurring in a busbar.SOLUTION: A busbar heat dissipation structure 1 includes a busbar 10 formed in a tubular shape, an insulating inner coating layer 20 covering an inner circumferential surface 11 of the busbar 10, and an insulating outer coating layer 30 covering an outer circumferential surface 12 of the busbar 10. Inside the inner coating layer 20, a cooling flow path 50 is provided so that a coolant C flows therethrough, and an outer wall of the cooling flow path 50 is formed by the inner coating layer 20.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a bus bar heat dissipation structure. [Background technology]

[0002] As the performance of electric vehicles, such as electric vehicles and plug-in hybrid vehicles, improves, there is a demand for an increased amount of current flowing through wire harnesses. To increase the amount of current flowing through a wire harness, it is conceivable to increase the diameter of the wires to reduce heat generation and current loss when current flows through the wire harness. However, increasing the diameter of the wires may increase the weight of the wire harness. Meanwhile, an integrated busbar that uses a cylindrical solid core and is capable of carrying a large current is known.

[0003] Patent Document 1 discloses an electric vehicle power distribution system including an integrated busbar, a first connection point configured to electrically connect to a molded connector on the busbar, and a second connection point electrically coupled to the busbar at an end opposite the molded connector. The integrated busbar includes a solid core conductor, an insulating layer, a shielding layer, and at least one molded connector formed from the solid core conductor. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2023-517714 Summary of the Invention [Problem to be solved by the invention]

[0005] By using bus bars instead of electric wires, it is possible to suppress temperature rise when the amount of current is increased and to make the wiring material thinner. However, when preparing bus bars that can carry large currents, the bus bars must be made thicker to suppress heat generation in the bus bars. In such cases, there is a risk that the vehicle installation space will be compressed.

[0006] The present invention has been made in view of the problems inherent in the conventional technology, and an object of the present invention is to provide a bus bar heat dissipation structure that can efficiently dissipate heat generated in the bus bar. [Means for solving the problem]

[0007] A busbar heat dissipation structure according to one aspect of the present invention includes a cylindrical busbar, an insulating inner coating layer that coats the inner peripheral surface of the busbar, and an insulating outer coating layer that coats the outer peripheral surface of the busbar. The busbar heat dissipation structure has a cooling flow path provided inside the inner coating layer and configured to allow a coolant to flow, and the outer wall of the cooling flow path is formed by the inner coating layer. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a bus bar heat dissipation structure that can efficiently dissipate heat generated in a bus bar. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view illustrating a bus bar heat dissipation structure according to an embodiment. [Figure 2] FIG. 1 is a cross-sectional view showing a bus bar heat dissipation structure according to an embodiment. [Figure 3] FIG. 1 is a perspective view illustrating a bus bar heat dissipation structure according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] The bus bar heat dissipation structure according to this embodiment will be described in detail below with reference to the drawings. Note that the dimensional proportions in the drawings are exaggerated for the sake of convenience and may differ from the actual proportions.

[0011] Fig. 1 is a perspective view showing a busbar heat dissipation structure 1 according to one embodiment. Fig. 2 is a cross-sectional view showing the busbar heat dissipation structure 1 according to one embodiment. As shown in Figs. 1 and 2, the busbar heat dissipation structure 1 according to this embodiment includes a busbar 10, a terminal joint portion 15, an inner coating layer 20, and an outer coating layer 30.

[0012] The busbar 10 is formed in a cylindrical shape. In this embodiment, the busbar 10 is formed in a rectangular cylindrical shape. The busbar 10 may be formed as a seamless, integral piece, or may be formed by bending a single flat plate into a cylindrical shape. The busbar 10 is disposed between an inner coating layer 20 and an outer coating layer 30. The cylindrical busbar 10 has an inner circumferential surface 11 and an outer circumferential surface 12. The inner circumferential surface 11 of the busbar 10 is coated and contacted with the inner coating layer 20. The outer circumferential surface 12 of the busbar 10 is coated and contacted with the outer coating layer 30.

[0013] At the longitudinal end of the busbar heat dissipation structure 1, the outer peripheral surface 12 of the busbar 10 is exposed. Because the outer peripheral surface 12 of the busbar 10 is exposed, a terminal joint 15 can be connected to the outer peripheral surface 12 of the busbar 10. This allows electrical connection to a mating member (not shown). The terminal joint 15 is connected to the exposed outer peripheral surface 12 of the busbar 10.

[0014] The busbar 10 may contain copper or aluminum as a primary component. The term "primary component" refers to the metal with the highest molar ratio among the metals contained in the busbar 10. The metal with the highest molar ratio among the metals contained in the busbar 10 may be contained in a molar ratio of 50% or more, 60% or more, 70% or more, 80% or more, 90% or more, or 95% or more. The material of the busbar 10 may be, for example, copper, aluminum, or an alloy containing these metals. From the viewpoint of electrical conductivity, the busbar 10 is preferably formed from copper or a copper alloy. From the viewpoint of weight reduction, the busbar 10 is preferably formed from aluminum or an aluminum alloy. While the material of the busbar 10 has been described above, the terminal joint 15 may also be made of the same material as that of the busbar 10. Specifically, the terminal joint 15 may contain copper or aluminum as a primary component. The busbar 10 and the terminal joint 15 may be made of the same material or different materials.

[0015] The inner coating layer 20 covers the inner circumferential surface 11 of the busbar 10. In this embodiment, the inner coating layer 20 is formed in a rectangular tubular shape. The inner coating layer 20 covers the entire inner circumferential surface 11 of the busbar 10. The inner coating layer 20 covers the entire inner circumferential surface 11 of the busbar 10 continuously in the circumferential direction. The inner coating layer 20 extends continuously in the longitudinal direction on the inner circumferential surface 11 of the busbar 10. The surface of the inner coating layer 20 opposite the busbar 10 forms the outer wall of the cooling flow path 50. At the longitudinal ends of the busbar heat dissipation structure 1, the outer circumferential surface 21 of the inner coating layer 20 is exposed.

[0016] The outer coating layer 30 covers the outer peripheral surface 12 of the busbar 10. In this embodiment, the outer coating layer 30 is formed in a rectangular tubular shape. The outer coating layer 30 covers the entire outer peripheral surface 12 of the busbar 10 continuously in the circumferential direction. The outer coating layer 30 extends continuously in the length direction of the outer peripheral surface 12 of the busbar 10. The surface of the outer coating layer 30 opposite to the busbar 10 is exposed and forms the outer wall of the busbar heat dissipation structure 1.

[0017] The inner coating layer 20 and the outer coating layer 30 are insulating and contain a resin. The inner coating layer 20 and the outer coating layer 30 contain a resin, thereby insulating the bus bar 10. The material for the inner coating layer 20 and the outer coating layer 30 can be a thermoplastic resin that ensures electrical insulation. The material for the inner coating layer 20 and the outer coating layer 30 may contain, for example, at least one of polyolefin and polyvinyl chloride. The polyolefin may contain, for example, at least one resin selected from the group consisting of polyethylene (PE), polypropylene (PP), ethylene copolymers, and propylene copolymers. The material for the inner coating layer 20 and the material for the outer coating layer 30 may be the same as or different from each other.

[0018] The cooling flow passage 50 is provided inside the inner coating layer 20 and configured to allow a coolant C to flow through it. The outer wall of the cooling flow passage 50 is formed by the inner coating layer 20. The bus bar 10 is cooled by the coolant C passing through the cooling flow passage 50. Specifically, the coolant C cools the inner coating layer 20, and heat is exchanged between the inner coating layer 20 and the bus bar 10, thereby cooling the bus bar 10. The coolant C may be cooling water or cooling oil.

[0019] The bus bar heat dissipation structure 1 according to this embodiment can be formed by insert molding, powder coating, liquid coating, or blow molding.

[0020] In insert molding, for example, the cylindrical busbar 10 is set in a mold, and resin is injection-molded onto the inside of the cylindrical busbar 10 to form the inner coating layer 20. Alternatively, resin is injection-molded onto the outside of the cylindrical busbar 10 to form the outer coating layer 30. In powder coating and liquid coating, resin is applied to the inside of the busbar 10 and cured to form the inner coating layer 20. Alternatively, resin is applied to the outside of the busbar 10 and cured to form the outer coating layer 30.

[0021] At the end of the busbar heat dissipation structure 1, by peeling off the end of the outer coating layer 30, it is possible to obtain a busbar heat dissipation structure 1 in which the outer peripheral surface 12 of the busbar 10 is exposed. Furthermore, at the end of the busbar heat dissipation structure 1 in which the outer peripheral surface 12 of the busbar 10 is exposed, by peeling off the end of the busbar 10, it is possible to obtain a busbar heat dissipation structure 1 in which the outer peripheral surface 21 of the inner coating layer 20 is exposed.

[0022] There are no particular limitations on the method for joining terminal joint portion 15 to outer peripheral surface 12 of bus bar 10. Terminal joint portion 15 may be joined to outer peripheral surface 12 of bus bar 10 by, for example, ultrasonic welding, welding, crimping, laser welding, or the like.

[0023] As described above, the busbar heat dissipation structure 1 according to this embodiment includes a cylindrical busbar 10, an insulating inner coating layer 20 that coats the inner circumferential surface 11 of the busbar 10, and an insulating outer coating layer 30 that coats the outer circumferential surface 12 of the busbar 10. The busbar heat dissipation structure 1 has a cooling flow path 50 that is provided inside the inner coating layer 20 and configured to allow a coolant C to flow therethrough, and the outer wall of the cooling flow path 50 is formed by the inner coating layer 20.

[0024] The busbar heat dissipation structure 1 according to this embodiment uses the busbar 10, so that the busbar heat dissipation structure 1 can be thinner than when an electric wire is used, even when used for applications in which a large current flows. Therefore, the busbar heat dissipation structure 1 can be lighter than when an electric wire is used.

[0025] Furthermore, the busbar heat dissipation structure 1 according to this embodiment has cooling channels 50 inside the cylindrical busbar 10, and the cooling channels 50 are arranged along the entire inner circumferential surface of the busbar 10, so that heat generated in the busbar 10 can be efficiently dissipated. Heat generation in the busbar 10 can be suppressed by flowing the coolant C through the cooling channels 50. Therefore, heat generation can be suppressed without increasing the thickness of the busbar 10, and the busbar 10 can be made thinner, contributing to cost reduction and weight reduction.

[0026] Furthermore, the busbar heat dissipation structure 1 according to this embodiment is easy to process because the routing path of the busbar 10 and the cooling flow passage 50 are integrated. That is, if the busbar 10 and the cooling flow passage 50 were separate and distinct, the busbar 10 and the cooling flow passage 50 would each need to be processed by bending or other processes. On the other hand, the busbar heat dissipation structure 1 according to this embodiment is easy to process because the routing path of the busbar 10 and the cooling flow passage 50 are integrated. Therefore, by bending the busbar 10, the cooling flow passage 50 is also formed accordingly. Therefore, the busbar heat dissipation structure 1 according to this embodiment is easy to process.

[0027] At the longitudinal end of the busbar 10, the outer peripheral surface 12 of the busbar 10 is exposed, and the busbar heat dissipation structure 1 may include a terminal joint 15 connected to the exposed outer peripheral surface 12 of the busbar 10. Because the outer peripheral surface 12 of the busbar 10 is exposed, the terminal joint 15 can be easily connected to the outer peripheral surface 12 of the busbar 10, and the busbar 10 can be electrically connected to a mating member (not shown).

[0028] The outer peripheral surface 21 of the inner covering layer 20 may be exposed at the longitudinal ends of the busbar heat dissipation structure 1. This configuration reduces the amount of busbar 10 used, thereby contributing to further weight reduction and cost reduction of the busbar heat dissipation structure 1.

[0029] In the above embodiment, an example has been described in which the cooling channel 50 has a rectangular shape in a cross section cut along the short side. However, the shape of the cooling channel 50 is not particularly limited, and for example, as shown in Fig. 3, the cooling channel 50 may have a circular shape in a cross section cut along the short side.

[0030] Although the present embodiment has been described above, the present embodiment is not limited to this, and various modifications are possible within the scope of the gist of the present embodiment. [Explanation of symbols]

[0031] 1 Busbar heat dissipation structure 10 Busbar 11 Inner surface 12 Outer surface 15 Terminal joint 20 Inner coating layer 21 Outer surface 30 Outer coating layer 50 Cooling Channel C Coolant

Claims

1. a cylindrical bus bar; an insulating inner coating layer that coats an inner peripheral surface of the bus bar; an insulating outer coating layer that coats an outer peripheral surface of the bus bar; Equipped with a cooling flow path provided inside the inner coating layer and configured to allow a coolant to flow therethrough, the outer wall of the cooling flow path being formed by the inner coating layer.

2. an outer circumferential surface of the bus bar is exposed at an end portion of the bus bar in a longitudinal direction; The bus bar heat dissipation structure according to claim 1 , further comprising a terminal joint portion connected to an exposed outer peripheral surface of the bus bar.

3. The bus bar heat dissipation structure according to claim 1 or 2, wherein an outer peripheral surface of the inner covering layer is exposed at longitudinal end portions of the bus bar heat dissipation structure.

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