Hybrid bus-bar for battery system

Abstract

The present invention relates to a busbar of a hybrid structure applied to a battery system, characterized by comprising: a rod member (20) forming a bent path on one side at a terminal portion (21) at one end; a flexible member (30) connected to the rod member (20) and forming a bent path on the other side at a terminal portion (35) at the other end; and a connecting member (40) connecting the connection portion of the rod member (20) and the flexible member (30). Accordingly, in electric vehicle battery systems subjected to external vibrations, it is flexibly positioned along relatively complex wiring paths while maintaining appropriate rigidity, thereby preventing interference and loosening and improving operational reliability.

Description

Technology Field

[0001] The present invention relates to a busbar of a battery system, and more specifically, to a hybrid busbar of a battery system that transmits power from a battery cell and a module to and from the inside and outside of the system. Background Technology

[0002] Batteries (rechargeable batteries) for electric vehicles and the like are mounted in the form of a battery pack, comprising multiple battery modules composed of connected battery cells housed within a case along with a Battery Management System (BMS). Busbars made of highly conductive materials such as aluminum and copper are used to electrically connect these multiple battery cells and modules. Typically, busbars, which are bent along wiring paths, are susceptible to interference with surrounding components or loosening of the connections due to external vibrations. Particularly in the case of automotive batteries, composite structures with partial flexibility are sometimes applied to prevent interference and loosening.

[0003] Korean Registered Patent Publication No. 2492980 (Prior Art 1) and Japanese Published Patent Publication No. 2021-136100 (Prior Art 2) are known as prior art documents that can be referenced in relation to a busbar with a composite structure.

[0004] Prior art document 1 includes a hollow braided wire; a thin plate laminated structure installed across the hollow of the braided wire; and a terminal portion fixed to both ends of the braided wire. The thin plate laminated structure is installed inside the braided wire and includes a main thin plate that is bent so that the exposed ends cover the upper and lower surfaces of the braided wire. Accordingly, the terminal portion is firmly fixed to prevent the ends from unraveling, and the effect of reducing electrical resistance is expected.

[0005] Prior art 2 describes a busbar for a vehicle comprising a plurality of wires, a flat flexible conductor, and a pair of connecting terminals each consisting of a metal plate of length connected to both ends of the flexible conductor, wherein the flexible conductor is characterized by a structure formed with an arc-shaped cross-section. Accordingly, as rigidity increases and the shape is easily maintained, an effect of suppressing interference with surrounding parts is expected.

[0006] However, according to the aforementioned prior art, there is room for improvement as it is insufficient to maintain adequate rigidity in relatively complex wiring paths. Prior art literature

[0007] Korean Registered Patent Publication No. 2492980 "Hybrid Flexible Busbar and Method for Manufacturing the Same" (Publication Date: September 15, 2021) Japanese Published Patent Publication No. 2021-136100 "Busbar for Vehicles" (Publication Date: September 13, 2021) The problem to be solved

[0008] The objective of the present invention, which aims to improve upon the aforementioned conventional problems, is to provide a hybrid busbar for a battery system that can maintain appropriate rigidity while being flexibly positioned along a relatively complex wiring path in an electric vehicle battery system subjected to external vibrations. means of solving the problem

[0009] To achieve the above objective, the present invention comprises a busbar of a hybrid structure applied to a battery system, characterized by comprising: a rod member forming a bent path on one side at a terminal portion of one end; a flexible member connected to the rod member and forming a bent path on the other side at a terminal portion of the other end; and a connecting member connecting the connection portion of the rod member and the flexible member.

[0010] As a detailed configuration of the present invention, the rod member is characterized by further comprising at least one of a gradient portion and an uneven portion at the end opposite to the terminal portion.

[0011] As a detailed configuration of the present invention, the flexible member is characterized by having a structure in which thin sheets with a thickness of 0.2 to 1 mm are laminated and compressed with a coating material.

[0012] As a detailed configuration of the present invention, the connecting member is characterized by forming a compression portion by electric resistance welding on a flexible member and selectively applying laser welding to the compression portion and its surroundings.

[0013] As a detailed configuration of the present invention, the connecting member is characterized by supporting the connecting portion by wrapping it with an insulating foil and further adding a low-melting-point conductive filler material to the connecting portion. Effects of the invention

[0014] As described above, according to the present invention, in an electric vehicle battery system subjected to external vibration, it is flexibly arranged along a relatively complex wiring path while maintaining appropriate rigidity, thereby preventing interference and loosening and improving operational reliability. Brief explanation of the drawing

[0015] FIG. 1 is a schematic diagram showing the application state of a busbar according to the present invention. FIG. 2 is a schematic diagram showing a rod member of a busbar according to the present invention. FIG. 3 is a schematic diagram showing the main configuration of a busbar according to the present invention. Specific details for implementing the invention

[0016] Hereinafter, embodiments of the present invention will be described in detail based on the attached drawings.

[0017] The present invention proposes a busbar of a hybrid structure applied to a battery system. It is intended for battery systems mounted as a power source for electric vehicles, but is not necessarily limited thereto. A battery system, in a narrow sense, refers to a battery pack accommodating a plurality of battery cells / cell modules. The busbar electrically connects one end and the other end of a wiring path allocated between battery cells or cell modules.

[0018] Referring to FIG. 1, a battery cell (13), a bus bar (15), etc., constituting a battery pack (10) are shown.

[0019] According to the present invention, the rod member (20) has a structure that forms a bent path on one side at one end of the terminal portion (21).

[0020] In FIG. 1, a terminal portion (21) and a coating material (23) constituting a rod member (20) of a busbar are shown. The rod member (20) uses highly conductive copper and has a structure bent at one side of the wiring path. The terminal portion (21) is formed to be connected to one end of the assigned wiring path by means such as bolting. The coating material (23) uses a resin having physical properties equal to or greater than epoxy and is formed in an area excluding both ends of the rod member (20).

[0021] As a detailed configuration of the present invention, the rod member (20) is characterized by further having at least one of a gradient portion (25) and an uneven portion (27) at the opposite end of the terminal portion (21).

[0022] Referring to FIG. 2, a gradient portion (25) and an uneven portion (27) constituting a rod member (20) are shown. The end opposite to the terminal portion (21) of the rod member (20) is a connection portion where the rod member (20) and the flexible member (30), which will be described later, are electrically contacted and connected. The gradient portion (25) is formed to have a constant slope on both sides of the connection portion. The uneven portion (27) is formed in the shape of a protrusion or a concave groove on the connection portion. The gradient portion (25) and the uneven portion (27) can be applied simultaneously to the connection portion of the rod member (20). In either case, the gradient portion (25) and the uneven portion (27) increase the mechanical connection strength along with the electrical conductivity of the connection portion.

[0023] In addition, according to the present invention, a flexible member (30) is connected to the rod member (20) and forms a structure that forms a bent path on the other side through the terminal portion (35) of the other end.

[0024] FIG. 1 shows a state in which a flexible member (30) equipped with a terminal portion (35) is connected to a rod member (20). The flexible member (30) uses highly conductive copper and has a structure that is bent at the other end of the wiring path. Since the flexible member (30) maintains higher flexibility than the rod member (20), it is placed in an area of ​​the wiring path that has relatively many bends. When the rod member (20) and the flexible member (30) are connected, a hybrid busbar can be formed. The terminal portion (35) is formed to be connected to the other end of the allocated wiring path by means such as bolting.

[0025] As a detailed configuration of the present invention, the flexible member (30) is characterized by having a structure in which a thin sheet material (31) with a thickness of 0.2 to 1 mm is laminated and compressed with a covering material (33).

[0026] Referring to FIG. 3, a thin sheet (31) and a covering material (33) constituting a flexible member (30) are shown. The thin sheet (31), which is stacked in multiple layers, maintains an overall thickness equal to or greater than that of the rod member (20). If the thin sheet (31) is too thin, strength and rigidity are weakened, and if it is too thick, flexibility is weakened. In connecting the flexible member (30) and the rod member (20), it is preferable to divide the thin sheet (31) evenly and connect the rod member (20) in the middle. Of course, this configuration is not limited to this and various variations are possible; for example, the flexible member (30) may be connected to only one side of the rod member (20). The covering material (33) uses an insulating heat-shrink tube to tightly bind the stacked thin sheet (31). In addition to the covering material (33), other means described later may be added to increase the compression force of the thin sheet (31).

[0027] Meanwhile, the thin sheet material (31) of the flexible member (30) can be applied differentially within a thickness range of 0.2 to 1 mm. Depending on the degree and number of bends in the wiring path, the thickness of the thin sheet material (31) can be applied differently on the inside and outside when arranging the flexible member (30). For example, to reduce deformation of the bent part, a thick thin sheet material (31) can be placed on the inside and a thin sheet material (31) on the outside.

[0028] In addition, according to the present invention, the connecting member (40) forms a structure that connects the connection portion of the rod member (20) and the flexible member (30).

[0029] In FIGS. 1 and 3, a connecting member (40) appears at the connection point between the rod member (20) and the flexible member (30). The connecting member (40) maintains the electrical / mechanical connection of the hybrid busbars arranged along a relatively complex wiring path. If the connection of the rod member (20), the flexible member (30), and the connecting member (40) provides appropriate rigidity, it is advantageous to prevent interference and loosening inside the battery pack (10).

[0030] As a detailed configuration of the present invention, the connecting member (40) is characterized by forming a compression portion (41) by electric resistance welding on a flexible member (30) and selectively applying laser welding to the compression portion (41) and its surroundings.

[0031] In FIG. 3, the compression portion (41) of the connecting member (40) is formed based on electric resistance welding. Electric resistance welding is advantageous for process automation when connecting the thin plate material (31) of the flexible member (30) and the rod member (20), and reduces contact resistance as well as deformation and residual stress. The compression portion (41) can be formed by large-diameter sputtering and seam welding. In addition, laser welding may be optionally added to increase the bonding strength. Laser welding can be extended not only to the area adjacent to the compression portion (41) but also to the middle area of ​​the flexible member (30).

[0032] Meanwhile, a compression portion (41) can be formed in the same manner on the terminal portion (35) of the flexible member (30). In particular, it is preferable to apply laser welding to the end region of the terminal portion (35) of the flexible member (30).

[0033] As a detailed configuration of the present invention, the connecting member (40) is characterized by supporting the connection portion by wrapping it with an insulating foil (45) and further adding a low-melting-point conductive filler material (43) to the connection portion.

[0034] In FIG. 3, the insulating foil (45) of the connecting member (40) appears at the connection portion between the rod member (20) and the flexible member (30). The insulating foil (45) uses a material that possesses flexural strength, heat resistance, flame retardancy, and flexibility based on electrical insulation. The filler material (43) is introduced into the gap of the connection portion without applying heat, thereby reducing contact resistance. The filler material (43) can be applied to the adjacent area of ​​the compression portion (41) as well as to the terminal portion (35) of the flexible member (30).

[0035] It is obvious to those skilled in the art that the present invention is not limited to the described embodiments and can be modified and varied in various ways without departing from the spirit and scope of the invention. Accordingly, such variations or modifications should be considered to fall within the scope of the claims of the present invention. Explanation of the symbols

[0036] 10: Battery pack 13: Battery cell 15: Busbar 20: Rod member 21: Terminal section 23: Coating material 25: Gradient 27: Uneven part 30: Flexible member 31: Thin sheet metal 33: Sheathing 35: Terminal part 40: Connecting member 41: Compression part 43: Filler material 45: Insulating foil

Claims

Claim 1 A hybrid busbar of a battery system having a hybrid structure, comprising: a rod member (20) forming a bent path on one side at a terminal portion (21) at one end; a flexible member (30) connected to the rod member (20) and forming a bent path on the other side at a terminal portion (35) at the other end; and a connecting member (40) connecting the connection portion of the rod member (20) and the flexible member (30); wherein the rod member (20) further comprises at least one of a gradient portion (25) and an uneven portion (27) at the opposite end of the terminal portion (21); the flexible member (30) has a structure formed by laminating a thin plate material (31) with a thickness of 0.2 to 1 mm and compressing it with a covering material (33); and the connecting member (40) supports the connection portion by wrapping it with an insulating foil (45) and further adds a low-melting-point conductive filler material (43) to the connection portion. Claim 2 delete Claim 3 delete Claim 4 A hybrid busbar of a battery system according to claim 1, wherein the connecting member (40) forms a compression portion (41) by electric resistance welding on a flexible member (30) and selectively applies laser welding to the compression portion (41) and its surroundings. Claim 5 delete

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