Automotive wiring harnesses (automotive electrical wiring harnesses) enable the physical connection of circuits for power sources and various electrical components on a vehicle. The wiring harnesses are distributed throughout the entire vehicle. If the engine is compared to the heart of a car, then the wiring harness is the neural network system of the car, which is responsible for the information transmission among various electrical parts of the entire vehicle.
The systems for manufacturing automotive wiring harnesses can be roughly divided into two categories:
(1) In terms of European and American countries, including China, the TS16949 system is used to control the manufacturing process.
(2) Mainly Japan: For instance, Toyota and Honda have their own systems to control the manufacturing process.
Automotive wiring harness manufacturers have their particularities and attach great importance to having experience in cable production and control over cable costs.
1. Wire (low-voltage wire, 60-600V)
Common specifications include wires with nominal cross-sectional areas of 0.5, 0.75, 1.0, 1.5, 2.0, 2.5, 4.0, 6.0 and other square millimeters.
2. Sheath
Types of wires:
Chinese standard lines: QVR, QFR, QVVR, QBV, QBVV, etc
Japanese standard lines: AV, AVS, AVSS, AEX, CAVUS, EB, TW, SHE-G, etc
German standard lines: FLY-A, FlY-B, etc
American standard lines: SXL, etc
The sheath (plastic shell), usually made of plastic, inserts the crimped terminal wires into it to ensure the reliability of the connection. The main materials include PA6, PA66, ABS, PBT, PP, etc
3. Terminal
A formed hardware component that is crimped onto wires to connect different wires and transmit signals, including male terminals, female terminals, ring terminals and round terminals, etc.
The main materials are brass and bronze (the hardness of brass is slightly lower than that of bronze), among which brass accounts for a larger proportion.
4. Cable ties (clips)
One component is usually made of plastic and is used to fix the wiring harness in the car. There are cable ties and corrugated pipe lock cable ties.
5. Pipe material
It is divided into corrugated pipes, PVC heat shrink pipes and glass fiber pipes. Braided tubes, wound tubes, etc. Used to protect the wiring harness. (Classified by different diameters)
① Corrugated pipe
Corrugated tubes generally account for about 60% or even more in the wiring harness wrapping. The main feature is its good wear resistance. It also has excellent high-temperature resistance, flame retardancy and heat resistance in high-temperature zones. The temperature resistance of corrugated pipes is between -40 ℃ and 150℃. Its material is generally divided into two types: PP and PA. PA material is superior to PP material in terms of flame retardancy and wear resistance. However, PP material is superior to PA material in terms of resistance to bending fatigue.
② The function of PVC heat shrink tubing is similar to that of corrugated tubing. PVC pipes have good flexibility and resistance to bending deformation. Moreover, PVC pipes are generally closed, so they are mainly used at the branch points where wire harnesses turn to ensure a smooth transition of the wires. The heat resistance temperature of PVC pipes is not high, generally below 80℃.
6. Tape
Production tape: Wound around the surface of the wire harness. It is divided into PVC, sponge tape, fabric tape, paper tape, etc. Quality marking tape: Used to mark the defects of the produced products.
Tape plays a role in binding, wear resistance, insulation, flame retardancy, noise reduction and marking in wire harnesses. It generally accounts for about 30% of the wrapping materials. Wire harness tapes are generally divided into three types: PVC tape, air-flannel tape and cloth-based tape. PVC tape has good wear resistance and flame retardancy. It can withstand temperatures around 80℃, has poor noise reduction performance and is relatively inexpensive. The material of flannel tape and cloth tape is PET. The flannel tape has the best wrapping and noise reduction properties, and its temperature resistance is around 105℃. The fabric tape has the best wear resistance and can withstand a maximum temperature of about 150℃. The common drawback of flannel tape and cloth tape is their poor flame retardancy and high price.