A dual-conductor, dual-insulation high-voltage connection aluminum busbar structure for electric vehicles and its fabrication process.

Abstract

This invention belongs to the field of high-voltage connecting aluminum busbar technology, and specifically relates to a dual-conductor, dual-insulation high-voltage connecting aluminum busbar structure for electric vehicles. It includes: two sets of flat aluminum conductors arranged parallel to each other vertically; a high-temperature resistant insulating tape wrapped around the flat aluminum conductors, allowing the two sets of flat aluminum conductors to form independent positive and negative connecting wires respectively; and an outer insulating layer wrapped around the entire outer side of the positive and negative connecting wires. The manufacturing process of the high-voltage connecting aluminum busbar structure includes the following steps: aluminum busbar extrusion, insulating tape winding, outer insulating layer extrusion, cutting, 3D bending, peeling, conductor punching, labeling, and packaging. The flattened design of this invention significantly reduces vertical space occupation, making it suitable for wiring in narrow areas such as the top and side walls of the battery pack, improving the overall vehicle space utilization. Furthermore, the production process is simplified from 17 steps to 9 steps, reducing carbon emissions and aligning with green manufacturing trends.

Description

Technical Field

[0001] This invention belongs to the field of high-voltage connection aluminum busbar technology, and in particular relates to a double-conductor, double-insulated high-voltage connection aluminum busbar structure for electric vehicles and its manufacturing process. Background Technology

[0002] With societal progress and development, people's demands for the driving experience of new energy vehicles are increasing, especially in terms of interior space utilization efficiency, driving range, and overall vehicle lightweighting. Against this backdrop, new energy vehicle charging systems and their high-voltage connection components face severe challenges: on the one hand, the high integration of battery packs, motors, and electronic control systems within a limited space results in extremely tight wiring space; on the other hand, traditional high-current cables generally use multi-strand copper conductor stranded structures, which, for the same current-carrying cross-sectional area, occupy a large vertical space and are heavy, not only limiting the compact design of the vehicle but also significantly increasing material costs and resource consumption.

[0003] The current mainstream high-voltage power cable manufacturing process is lengthy, typically involving 17 steps: copper wire drawing → copper stranding → cage stranding → insulation extrusion → insulation irradiation crosslinking → braided shielding → sheath extrusion → sheath irradiation crosslinking → wire cutting and stripping → shielding layer trimming → corrugated tube insertion → heat shrink tubing insertion → high-voltage connection terminal insertion → high-voltage connection terminal riveting → heat shrink tubing baking → labeling → packaging. This process not only requires large equipment investment and high energy consumption, but also involves many manual interventions, which can easily introduce quality fluctuations, resulting in poor product consistency, long production cycles, and high overall costs.

[0004] Therefore, the industry urgently needs a new type of high-voltage connection structure that can be efficiently laid in a confined space, while possessing excellent heat dissipation performance, flame retardant and fireproof capabilities, electromagnetic compatibility (EMC) and lightweight characteristics, in order to meet the comprehensive requirements of next-generation new energy vehicles and energy storage systems for high power density, high safety and low-cost manufacturing. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of traditional separate antenna designs mentioned in the background art, including interference between antennas and cumbersome assembly, by providing an integrated structure that integrates two types of antennas through a shared substrate. This structure reduces space occupation, simplifies the assembly process, and lowers the risk of interference. It is a dual-conductor, dual-insulated high-voltage connection aluminum busbar structure for electric vehicles and its manufacturing process.

[0006] To achieve the above objectives, the present invention adopts the following technical solutions: A double-conductor, double-insulated high-voltage connection aluminum busbar structure for electric vehicles, comprising: Two sets of flat aluminum conductors are arranged in parallel vertically, and the left and right ends of the flat aluminum conductors are rounded. High-temperature resistant insulating tape, which is wrapped around the outside of flat aluminum conductors, so that the two sets of flat aluminum conductors form independent positive and negative connecting wires respectively, and the positive and negative connecting wires still maintain the stacked combination. An outer insulation layer is provided, which wraps around the entire outer side of the positive and negative connecting wires.

[0007] Furthermore, the flat aluminum conductor is made of AL6101-T64 aluminum busbar with a thickness of 6.3 mm and a width of 35 mm.

[0008] Furthermore, the high-temperature resistant insulating tape is made of polyimide material.

[0009] Furthermore, the outer insulating layer is made of polydodecyl lactam or cross-linked polyolefin material.

[0010] A fabrication process for a double-conductor, double-insulated high-voltage connection aluminum busbar structure for electric vehicles includes the following steps: S1: Aluminum busbar extrusion, which involves forming high-purity aluminum ingots into flat aluminum busbars through a hot extrusion process; S2: Insulating tape wrapping: A CNC wrapping machine is used to wrap polyimide insulating tape around the surface of the aluminum busbar with constant tension and constant pitch. S3: Outer insulation layer extrusion, using a twin-screw extruder with precision molds to continuously coat the outer side of the dual conductor assembly with insulating material; S4: Cutting, the servo-controlled shearing machine precisely cuts the material to the specified length according to the drawing requirements; S5: 3D bending, using a five-axis CNC bending machine to cold-bend aluminum strips according to a three-dimensional wiring path; S6: Peeling, precisely removing the inner and outer insulation layers in the end connection area; S7: Conductor punching, pre-punching mounting holes or tapping threads at the connection end to facilitate reliable connection with battery modules or inverter terminals later; S8: Labeling, using high-temperature resistant ink for online printing of product model, batch number, and polarity information; S9: Packaging: Packed in rolls or boxes according to moisture-proof and scratch-proof requirements, with desiccant and humidity indicator card inside.

[0011] Compared with existing technologies, the advantages of this double-conductor, double-insulated high-voltage connection aluminum busbar structure for electric vehicles and its fabrication process are as follows: 1. The flattened structure design significantly reduces the vertical space occupied, making it suitable for wiring in narrow areas such as the top and side walls of the battery pack, thereby improving the overall space utilization of the vehicle.

[0012] 2. The inner layer uses polyimide insulating tape (temperature resistance 200℃ / instantaneous 400℃), and the outer layer uses PA12 (polydodecanoic acid) or XLPO (crosslinked polyolefin) sheath (temperature resistance 125℃ / instantaneous 175℃), providing high overall heat resistance and adaptability to high-power charging and discharging conditions.

[0013] 3. The entire structure meets the UL VW-1 fire rating, and the materials themselves are flame-retardant, low-smoke, and halogen-free, improving the vehicle's passive safety performance.

[0014] 4. The aluminum busbar with a large width-to-thickness ratio of 6.3×35 mm is used to effectively increase the heat dissipation surface area, reduce the temperature rise, and improve the current carrying capacity (the temperature rise is 15-20% lower than that of round copper cable under the same cross-sectional area).

[0015] 5. The positive and negative conductors are integrated into one piece to form a rigid or semi-flexible "busbar" cable, which simplifies the assembly process, improves connection reliability, and at the same time, the appearance is neat and beautiful, enhancing the user's perception of the quality of high-end electric vehicles.

[0016] 6. The production process has been streamlined from 17 steps to 9 steps, eliminating high-energy-consuming processes such as irradiation crosslinking, braided shielding, and heat shrink tubing baking, thereby reducing carbon emissions and conforming to the trend of green manufacturing; 7. Replacing copper with aluminum reduces material costs by about 40%, and aluminum resources are abundant, which is conducive to supply chain security and sustainable development. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the double-conductor, double-insulated high-voltage connection aluminum busbar structure for electric vehicles provided by the present invention. Figure 2 This is a process flow diagram of the fabrication process of the double-conductor, double-insulated high-voltage connection aluminum busbar structure for electric vehicles provided by the present invention.

[0018] In the diagram, 1 is a flat aluminum conductor, 2 is a high-temperature resistant insulating tape, and 3 is an outer insulating layer. Detailed Implementation

[0019] The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0020] Reference Figure 1 A double-conductor, double-insulated high-voltage connection aluminum busbar structure for electric vehicles, comprising: Two sets of flat aluminum conductors 1 are stacked parallel to each other, electrically isolated from each other but mechanically integrated. Each conductor uses AL6101-T64 aluminum alloy strip with a thickness of 6.3 mm and a width of 35 mm. This alloy has high strength, good conductivity (approximately 55% of copper), and excellent creep resistance, making it suitable for long-term high-current operation. The left and right edges of the conductors are rounded to effectively reduce the electric field concentration effect, increase the partial discharge initiation voltage, improve the heat dissipation path, and accelerate the conduction of heat to the surrounding medium. The high-temperature resistant insulating tape 2 is tightly wrapped around the outer surface of each set of flat aluminum conductors 1. It is wrapped in multiple layers using a fully automatic wrapping machine with an overlap rate of not less than 50%, ensuring that there are no exposed metal areas. The insulating tape is made of polyimide (PI) film, which has excellent thermal stability and dielectric strength. Its rated operating temperature can reach 200℃, and it can withstand instantaneous overload of 400℃ (such as short circuit or rapid acceleration conditions) for several minutes without significant carbonization or breakdown. It also has excellent flame retardancy (meeting UL94 V-0 rating) and low temperature toughness (not breaking at -200℃). The two sets of flat aluminum conductors 1 form independent positive and negative connecting wires, and the positive and negative connecting wires are still stacked on top of each other. The outer insulation layer 3 completely wraps around the insulated positive and negative connecting wires, forming an integrated sealed structure. Preferably, a high-speed dedicated extruder with a pressure die is used to uniformly extrude molten polydodecyl lactam (PA12) or cross-linked polyolefin (XLPO) material and tightly adhere it to the surface of the inner layer structure. Appropriate back pressure is applied during extrusion to eliminate interfacial air gaps and improve interlayer adhesion. Subsequently, the cable is rapidly cooled and shaped in a water bath to obtain a dimensionally stable, smooth-surfaced finished cable. This outer insulation layer has a rated temperature of up to 125°C and an instantaneous heat resistance of over 175°C. The entire cable passes the UL VW-1 vertical burning test, meeting the fire safety requirements for automotive high-voltage components.

[0021] Reference Figure 2 A fabrication process for a double-conductor, double-insulated high-voltage connection aluminum busbar structure for electric vehicles, characterized by comprising the following steps: S1: Aluminum busbar extrusion, which involves hot extruding high-purity aluminum ingots into AL6101-T64 flat aluminum busbars with dimensions of 6.3×35 mm; S2: Insulating tape wrapping: Using a CNC wrapping machine, polyimide insulating tape is wrapped around the surface of the aluminum busbar with constant tension and constant pitch. The wrapping tension is controlled within the range of 0.5–1.0 N to avoid conductor deformation or insulation wrinkles. S3: Outer insulation layer extrusion. A twin-screw extruder with precision molds is used to continuously coat the outside of the dual conductor assembly with PA12 or XLPO material. The extrusion speed is synchronized with the traction to ensure that the wall thickness tolerance is ≤ ±0.2 mm. S4: Cutting, the servo-controlled shearing machine precisely cuts the material to the specified length according to the customer's drawings; S5: 3D bending utilizes a five-axis CNC bending machine to cold-bend aluminum busbars according to the three-dimensional wiring path. The minimum bending radius can be ≤2 times the conductor thickness / width, without cracking or insulation damage. S6: Peeling, precisely removing the inner and outer insulation layers in the end connection area, using laser or mechanical milling methods to avoid damaging the aluminum conductor surface; S7: Conductor punching, pre-punching mounting holes or tapping threads at the connection end to facilitate reliable connection with battery modules or inverter terminals later; S8: Labeling, using high-temperature resistant ink for online printing of product model, batch number, polarity marking, and other information, supporting QR code traceability system integration; S9: Packaging: Packed in rolls or boxes according to moisture-proof and scratch-proof requirements, with desiccant and humidity indicator card inside to ensure safe transportation and storage.

[0022] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A double-conductor, double-insulated high-voltage connection aluminum busbar structure for electric vehicles, characterized in that, include: Two sets of flat aluminum conductors (1) are arranged in parallel vertically, and the left and right ends of the flat aluminum conductors (1) are rounded. High-temperature resistant insulating tape (2) is wrapped around the outside of flat aluminum conductor (1), so that the two sets of flat aluminum conductors (1) form independent positive and negative connecting wires respectively, and the positive and negative connecting wires are still stacked on top of each other. The outer insulation layer (3) is wrapped around the entire outer side of the positive electrode connecting wire and the negative electrode connecting wire.

2. A double-conductor, double-insulated high-voltage connection aluminum busbar structure for electric vehicles according to claim 1, characterized in that, The flat aluminum conductor (1) is made of AL6101-T64 aluminum busbar with a thickness of 6.3 mm and a width of 35 mm.

3. A double-conductor, double-insulated high-voltage connection aluminum busbar structure for electric vehicles according to claim 1, characterized in that, The high-temperature resistant insulating tape (2) is made of polyimide material.

4. A double-conductor, double-insulated high-voltage connection aluminum busbar structure for electric vehicles according to claim 1, characterized in that, The outer insulation layer (3) is made of polydodecyl lactam or cross-linked polyolefin material.

5. A fabrication process for a double-conductor, double-insulated high-voltage connection aluminum busbar structure for electric vehicles, characterized in that, Includes the following steps: S1: Aluminum busbar extrusion, which involves forming high-purity aluminum ingots into flat aluminum busbars through a hot extrusion process; S2: Insulating tape wrapping: A CNC wrapping machine is used to wrap polyimide insulating tape around the surface of the aluminum busbar with constant tension and constant pitch. S3: Outer insulation layer extrusion, using a twin-screw extruder with precision molds to continuously coat the outer side of the dual conductor assembly with insulating material; S4: Cutting, the servo-controlled shearing machine precisely cuts the material to the specified length according to the drawing requirements; S5: 3D bending, using a five-axis CNC bending machine to cold-bend aluminum strips according to a three-dimensional wiring path; S6: Peeling, precisely removing the inner and outer insulation layers in the end connection area; S7: Conductor punching, pre-punching mounting holes or tapping threads at the connection end to facilitate reliable connection with battery modules or inverter terminals later; S8: Labeling, using high-temperature resistant ink for online printing of product model, batch number, and polarity information; S9: Packaging: Packed in rolls or boxes according to moisture-proof and scratch-proof requirements, with desiccant and humidity indicator card inside.

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