On-vehicle bus bar and method for manufacturing the same

Abstract

To surely prevent short circuit accompanied by contact of a metal bar with a metal structure in its periphery.SOLUTION: An on-vehicle bus bar 1 has a metal bar 10, a fireproof tape and an insulator layer 30. The one or two or more fireproof tapes are overlapped and wound around the metal bar 10, at least the one fireproof tape is longitudinally attached thereto and wound therearound, and the metal bar 10 and the fireproof tape are coated with the insulator layer 30.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a busbar suitable for in-vehicle use and a method for manufacturing the same. [Background technology]

[0002] 2. Description of the Related Art In electric vehicles such as BEVs (Battery Electric Vehicles) and HEVs (Hybrid Electric Vehicles), a "bus bar" may be used to supply power between a battery unit and an inverter. In recent years, electric vehicles are not only motor-driven, but also have electrically-driven brakes, steering wheels, and the opening and closing of doors and windows. Therefore, in the event of an emergency evacuation due to an accident or a fire caused by poor maintenance, the power supply system, including the battery unit and bus bar, is required to maintain a power supply for a certain period of time and keep the electrical equipment running in order to ensure evacuation and notification. Lithium-ion batteries are widely used as batteries. These batteries can deform and catch fire due to external heating or self-heating, so the unit is protected in a robust, fire-resistant container.

[0003] On the other hand, in addition to the battery unit, the bus bar also needs to have a fire-resistant structure. Patent Document 1 discloses a structure in which a bandage member (30A) is wound around a metal bar (10) and the outside of the bandage member is covered with an insulating tube (20). The bandage member is made of a metal wire coated with a coating material (31) that has electrical insulation and fire resistance. In this structure, even if the insulating tube of the bus bar is lost in the event of a fire, the bandage member does not disappear but remains bound to the metal bar, supporting the metal bar so that it does not come into contact with the surrounding metal structure (4), thereby preventing a short circuit (see paragraphs 0030-0036, 0047, Figures 3-4, and 7). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2022-545548 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the structure of Patent Document 1, the polymeric material that constitutes the insulating tube remains as charcoal in the event of a fire. Because charcoal has electrical conductivity, if the charcoal remains attached to the metal bar and comes into contact with the surrounding metal structure, it is not possible to prevent a short circuit. 5A and 5B, it is also possible to wrap the fire-resistant tape 20 transversely around the metal bar 10, or to spirally wind a first piece of fire-resistant tape 20 with a gap therebetween and then spirally wind a second piece of fire-resistant tape 20 along the gap. In such a case, when the metal bar 10 is curved or bent, gaps are generated between the side edges of the fire-resistant tape 20, and the char remaining therein may get mixed inside the fire-resistant tape 20, causing a short circuit. Therefore, a main object of the present invention is to provide a bus bar and a manufacturing method thereof that can reliably prevent a short circuit caused by contact between the metal bar and a surrounding metal structure. [Means for solving the problem]

[0006] In order to solve the above problem, according to one aspect of the present invention, A vehicle bus bar having a metal bar, a fire-resistant tape, and an insulating layer, One or more of the fire-resistant tapes are wound around the metal bar in an overlapping manner, with at least one of the fire-resistant tapes being wound vertically; The metal bar and the fire-resistant tape are covered with the insulating layer, thereby providing an in-vehicle bus bar.

[0007] According to another aspect of the present invention, A method for manufacturing an automotive bus bar having a metal bar, a fire-resistant tape, and an insulating layer, comprising the steps of: A step of overlapping and winding one or more pieces of the fire-resistant tape around the metal bar, at least one of the pieces being longitudinally wrapped around the metal bar; extruding a resin onto the metal bar and the fire resistant tape to coat them with the insulating layer; The present invention provides a method for manufacturing an in-vehicle bus bar, comprising: Effect of the Invention

[0008] According to the present invention, it is possible to reliably prevent a short circuit caused by contact between a metal bar and a surrounding metal structure. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a perspective view showing a schematic configuration of an in-vehicle bus bar. [Diagram 2] FIG. 2 is a cross-sectional view showing a schematic configuration of an in-vehicle bus bar. [Diagram 3] FIG. 2 is an exploded perspective view showing a schematic configuration of an in-vehicle bus bar. [Figure 4] FIG. 4 is a diagram showing a modification of FIG. 3. [Diagram 5] FIG. 1 is a diagram illustrating a conventional ideal structure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, a bus bar according to a preferred embodiment of the present invention will be described. In this specification, the use of "to" indicating a numerical range means that the numerical range includes the lower limit and the upper limit.

[0011] 1 and 2, an in-vehicle busbar 1 is mainly composed of a metal bar 10, a fire-resistant tape 20, and an insulating layer 30. One or more fire-resistant tapes 20 are overlap-wound around the metal bar 10, and these are covered with an insulating layer 30. "Overlap winding" includes both so-called vertical winding and horizontal winding, and at least one fire-resistant tape 20 is vertically wrapped around the metal bar 10 (see below).

[0012] The metal bar 10 is generally made of a single metal plate, and its thickness and width are determined according to the magnitude of the current flowing therethrough, and it is manufactured in various lengths according to the installation location or installation conditions. The metal bar 10 may be a laminate of multiple thin metal plates. For example, the metal bar 10 may have a flexible structure that can be twisted or bent by laminating thin metal plates of about 0.1 to 0.3 mm in thickness and welding both ends of the laminate together. The metal plate or sheet metal of the metal bar 10 is preferably made of copper or a copper alloy.

[0013] One of the ends of the metal bar 10 is connected to the (+) terminal of one of the batteries, and the other end is connected to the (-) terminal of the other battery. For example, if the battery terminals are bolt type, the connection between the battery and the vehicle bus bar 1 (metal bar 10) can be firmly fixed by fitting the terminals into the holes 12 at both ends of the metal bar 10 and fastening them with nuts.

[0014] The fire-resistant tape 20 is made of so-called mica tape, which exhibits insulating properties at high temperatures. Mica is a natural mineral that is dark green (called 'kika' in Japanese) and has excellent electrical insulation and heat resistance. Although mica itself is a mineral, when it is made into a tape, it has good flexibility and can be a material suitable for curving or bending. The mica tape may be a glass mica tape in which mica is bonded to a glass cloth, or a plastic mica tape in which mica is bonded to a plastic film made of polyethylene or the like.

[0015] 3A, the fire-resistant tape 20 is wrapped around the metal bar 10 in a longitudinal direction, and the glass yarn 22 is wrapped around the fire-resistant tape 20 (the glass yarn 22 is loosely wound and pressed down). "Longitudinal wrapping" means that the long tape is arranged along the length of the object to be wrapped and wrapped around the object in a cylindrical shape so that both side edges are wrapped inward. Instead of the glass yarn 22, as shown in FIG. 3B, a polyethylene terephthalate (PET) tape 24 may be wound around and fixed to the fire-resistant tape 20 with a certain gap therebetween, or as shown in FIG. 3C, an adhesive tape 26a may be applied along the surface of the side edge of the fire-resistant tape 20 to fix the fire-resistant tape 20, or as shown in FIG. 3D, an adhesive 26b may be applied to the back surface of the side edge of the fire-resistant tape 20 or an adhesive tape 26a may be applied to fix the fire-resistant tape 20.

[0016] The insulating layer 30 is formed by extruding a certain resin through the die of an extruder. The resin is preferably a flame-retardant resin, and may be, for example, polyamide (PA; PolyAmide), polyvinyl chloride (PVC; PolyVinyl Chloride), polyethylene (PE; PolyEthylene), polypropylene (PP; PolyPropylene), or the like.

[0017] Next, a method for manufacturing the vehicle-mounted bus bar 1 will be described.

[0018] First, a sheet of fire-resistant tape 20 is wrapped lengthwise around a metal bar 10, and then the glass yarn 22 is pressed and wrapped around the sheet to fix the fire-resistant tape 20 in place. Thereafter, a certain amount of resin is extruded onto the outside of the fire-resistant tape 20 to form an insulating layer 30, thereby forming a precursor of the vehicle-mounted bus bar 1. Finally, the precursor is curved or bent depending on the installation location or installation conditions, and the vehicle-mounted busbar 1 can be manufactured (completed).

[0019] According to the above-described vehicle-mounted busbar 1, the fire-resistant tape 20 is wound vertically directly around the metal bar 10. Therefore, even if a fire occurs due to an accident or poor maintenance and the insulating layer 30 remains as charcoal, the charcoal that remains will not adhere to the metal bar 10, and it is possible to prevent the charcoal from coming into contact with surrounding metal structures and causing a short circuit. Additionally, according to the vehicle-mounted busbar 1, the fire-resistant tape 20 contains mica and has a certain degree of flexibility. Therefore, when the precursor of the vehicle-mounted busbar 1 is curved or bent, the fire-resistant tape 20 follows the curve or bend without creating a gap between the fire-resistant tape 20 and the metal bar 10. In such a case, as in the above, even if a fire occurs due to an accident or poor maintenance and the insulator layer 30 remains as charcoal, the remaining charcoal will not adhere to the metal bar 10 and can be prevented from coming into contact with surrounding metal structures and causing a short circuit.

[0020] As described above, the vehicle-mounted bus bar 1 can reliably prevent a short circuit caused by contact between the metal bar 10 and a surrounding metal structure.

[0021] The overlapping and winding manner of the fire-resistant tape 20 of the vehicle-mounted busbar 1 is not limited to the structure shown in FIG. 3, and the number of layers and the winding method can be appropriately changed.

[0022] For example, as shown in Figures 4A and 4B, two pieces of fire-resistant tape 20 may be prepared and each may be overlapped and wrapped vertically around the metal bar 10. In such a case, it is preferable to wrap the first fire-resistant tape 20 vertically so that the side edge of the second fire-resistant tape 20 is inverted vertically or horizontally. As shown in FIG. 4A, a first fire-resistant tape 20 may be wound with a polypropylene yarn 28, and a second fire-resistant tape 20 may be wound with a glass yarn 22, and the fire-resistant tapes 20 may be fixed in place. As shown in FIG. 4B, the PET tape 24 may be wound around and fixed to the second fire-resistant tape 20 with a certain gap therebetween. 4C, two pieces of fire-resistant tape 20 may be prepared, and the first piece of fire-resistant tape 20 may be wrapped lengthwise around the metal bar 10, while the second piece of fire-resistant tape 20 may be wrapped widthwise around the first piece of fire-resistant tape 20. "Widthwise wrapping" refers to wrapping a long piece of tape in a spiral shape along the length of the object to be wrapped, with the side edge of the tape overlapping the previously wrapped tape. [Industrial Applicability]

[0023] The present invention relates to an in-vehicle bus bar and a manufacturing method thereof, and is particularly useful for providing a bus bar that can reliably prevent short circuits caused by contact between the metal bar and surrounding metal structures. [Explanation of symbols]

[0024] 1. Automotive Bus Bars 10 Metal Bar 12 holes 20 Fireproof Tape 22 Glass Yarn 24 PET tape 26a Adhesive tape 26b Adhesive 28 Polypropylene Yarn 30 Insulator layer

Claims

1. A vehicle bus bar having a metal bar, a fire-resistant tape, and an insulating layer, One or more of the fire-resistant tapes are wound around the metal bar in an overlapping manner, with at least one of the fire-resistant tapes being wound longitudinally; 13. An in-vehicle bus bar, comprising: the metal bar and the fire-resistant tape covered with the insulating layer.

2. The vehicle bus bar according to claim 1, The vehicle-mounted bus bar is characterized in that one or more pieces of the fire-resistant tape are wound vertically around the metal bar, or the vertical and horizontal windings are combined.

3. A method for manufacturing an automotive bus bar having a metal bar, a fire-resistant tape, and an insulating layer, comprising the steps of: A step of overlapping and winding one or more pieces of the fire-resistant tape around the metal bar, at least one of the pieces being longitudinally wrapped around the metal bar; extruding a resin onto the metal bar and the fire resistant tape to coat them with the insulating layer; A method for manufacturing an in-vehicle bus bar, comprising:

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