Manufacturing Process and Material Selection of High-voltage Wire Harness

Manufacturing Process 

First, the metal material is stretched into a single wire of a specified diameter through a wire drawing machine; then annealing is performed to increase its flexibility; and then multiple single wires are twisted into a single wire to enhance its mechanical strength. The insulation process includes wrapping the insulating material around the outside of the wire, using an extruder to ensure that the material is evenly distributed, and cooling and solidifying to form a solid insulation layer. The manufacturing of the shielding layer is to tightly wrap materials such as metal braided mesh or aluminum foil around the outside of the insulation layer. This step requires close contact between the shielding material and the wire to effectively reduce electromagnetic interference. Connectors are installed at both ends of the high-voltage wire harness to connect to other electrical systems of the vehicle. The manufacture of the connector relies on precision machining and injection molding technology, which can ensure its accuracy. During the assembly process, it is necessary to ensure that the contact between the wire and the connector is close and seamless, thereby reducing contact resistance and improving conductivity.

Material Selection

• Wire material: The high-voltage wiring harness design of new energy vehicles uses high-purity copper or aluminum as the main conductive material to meet the needs of high current and high voltage transmission. Copper wires are widely used due to their excellent conductivity and mechanical strength, while in some specific applications, lightweight and low-cost aluminum wires also show their advantages. In order to ensure the safe use of high-voltage wiring harnesses, the outer layer of the wire is wrapped with insulating materials. These insulating materials mainly include cross-linked polyethylene (XLPE), polyvinyl chloride (PVC) and ethylene propylene rubber (EPR). In the application of new energy vehicles, cross-linked polyethylene is particularly valued for its excellent electrical properties and heat resistance.

• Shielding material: In automobile manufacturing, in order to reduce the negative impact of electromagnetic interference (EMI) on vehicle electronic systems, high-voltage wiring harnesses are designed to use specific shielding materials. These materials can effectively absorb and block electromagnetic waves, thereby significantly reducing electromagnetic interference. Commonly used shielding materials include metal braided mesh, aluminum foil and conductive cloth, etc., each of which contributes to the minimization of electromagnetic interference in different ways to ensure the stability and reliability of vehicle electronic systems.

• Sheath material: The sheath is an important component of the high-voltage wire harness, and its main function is to protect the wire harness from the adverse effects of the external environment. In order to ensure its performance, the sheath should have a variety of characteristics, including weather resistance, abrasion resistance, oil resistance and flame retardancy. Common sheath materials on the market are mainly polyvinyl chloride (PVC), thermoplastic elastomer (TPE) and nylon. These materials have their own characteristics, but they are all designed to provide the necessary protection to maintain the normal operation of the high-voltage wire harness.