The automotive wiring harness is the main network of the automotive circuit. At present, the wiring harness is generally composed of wires, connectors, wiring harness wrapping materials and body fixings. The automotive wiring harness must ensure the transmission of electrical signals and the reliability of the connection circuit, supply the specified current value to the electronic and electrical components, prevent electromagnetic interference to the surrounding circuits, and eliminate electrical short circuits.
The wrapping of automobile wiring harness plays the role of wear resistance, flame retardancy, corrosion resistance, interference prevention, noise reduction and beautification of appearance. Generally, the wrapping design plan is formulated according to the working environment and space size.
Ⅰ. Bandaging design
The working environment of the engine wiring harness is harsh, so it is wrapped with a corrugated tube that is highly flame retardant, waterproof, and has high mechanical strength;
The working environment of the front cabin line is relatively poor. Most branches are wrapped with corrugated tubes with good flame retardancy, and some branches are wrapped with PVC heat shrink tubes;
The instrument line has a small working space and a relatively good environment, so it can be fully wrapped or wrapped with tape;
The working space of the door line and the canopy line is small, so they can be fully wrapped with tape, and some branches can be wrapped with PET winding tubes;
Thinner roof lines can be attached to the body with sponge tape;
The chassis wire has many contact points with the vehicle body, so it is wrapped with a corrugated tube to prevent the wire harness from being worn;
Use sponge tape to wrap the doors and locations in the cab where shock and noise reduction requirements are high.
Ⅱ. Bandaging materials
Generally, corrugated tubes, heat shrink tubes, PET winding tubes, tapes, sponge tapes, etc. are used.
Bellows
The corrugated pipe generally occupies about 60% of the wiring harness wrapping position, and open corrugated pipes are mostly used. Its main characteristics are good wear resistance and high temperature resistance. The temperature resistance of the corrugated pipe is between -40-150℃, and the flame retardancy is relatively good. The corrugated pipe itself has good flexibility and good bending resistance. The corrugated pipe is most common in the cabin and the front and rear protective structures. The materials of the corrugated pipe include polypropylene (PP), nylon (PA), polypropylene modified (PPMOD), etc.
PA material is better than PP material in terms of flame retardancy and wear resistance; however, PP material is stronger than PA material in terms of bending fatigue resistance.
Heat shrink tubing
Heat shrink tubing has high temperature shrinkage, soft flame retardant, insulation and corrosion resistance, good softness and bending deformation resistance, low shrinkage temperature and fast shrinkage. It is widely used in various positions of various automotive wiring harnesses. It is generally closed, with average wear resistance and voltage level of 600V.
Heat shrink tubing is mainly used in the four-door and cab environments where the environment is relatively good, especially at the branch points where the wiring harness turns, so as to make the wires transition smoothly.
Heat shrink tubing can be divided into single-wall heat shrink tubing and double-wall heat shrink tubing (including glue) based on its structure.
Heat shrink tubing can be divided into PVC heat shrink tubing, cross-linked polyolefin (including PE, PP) heat shrink tubing, and cross-linked PET heat shrink tubing based on the material.
PET spiral tube, PET braided tube
The appearance of the spiral tube is a black mesh protective sheet, which is wrapped around the wire harness after curling. Its main features are good flexibility and easy bending. Due to its poor wear resistance, it is rarely seen. It can be seen in places where the trunk wire harness needs to be bent, or where thicker cables are branched. The main features of the PET braided tube are good flexibility and easy bending, and it is rarely used in automobiles.
Wiring tape
Tape winding is the most basic and most commonly used protective material for wire harnesses. The entire vehicle wire harness needs to be fixed and formed by tape. Tape has good corrosion resistance, oil resistance and insulation properties. It plays the role of bundling, wear resistance, insulation, flame retardancy, noise reduction, and marking in wire harnesses.
According to the protection level of the wire harness, the tape wrapping methods are divided into full wrapping, partial wrapping and flower wrapping.
According to the tape base material, it can be divided into PVC tape, high temperature resistant PVC tape, cloth-based tape, flannel tape, sponge tape, etc.
PVC tape
It has good wear resistance and flame retardancy; the temperature resistance is around 80°C, the noise reduction is poor, and the price is relatively cheap.
High temperature resistant PVC tape
Good wear resistance and flame retardancy; temperature resistance is around 105°C.
Such as: Yongle FC series
Cloth-based tapes can be divided into polyester cloth tapes, fiber cloth tapes, non-woven tapes, and flannel tapes. The base material is mostly PET.
Polyester cloth tape
The base material is PET polyester cloth. The temperature resistance is about 150℃, and it can be used for high temperature winding of wiring harnesses in the automobile engine area.
Fiber cloth tape
The base material is cotton fiber cloth or PET fiber cloth. It is high temperature resistant, can be torn by hand and has good flexibility. It is used for high temperature winding of automotive wiring harnesses.
Non-woven tape
The base material is PET non-woven fabric. It has a temperature resistance of about 125°C, has good noise reduction performance, is flexible, and can be torn by hand.
Flannel tape
The base material is PET flannel or polyamide flannel. It has good high resistance, wear resistance, oil resistance and aging resistance, temperature resistance of about 105℃, and outstanding wrapping performance and noise reduction performance.
Sponge tape
Its function and usage are similar to those of tape. Its main feature is good noise reduction and shock absorption performance. It is mostly used in car doors and cabs where shock absorption and noise reduction are required, and can eliminate abnormal noise from wiring harnesses.
