With the deep integration of the new generation of information and communication, new energy, new materials and other technologies with the automotive industry, the "new four modernizations" of the automotive industry - electrification, intelligence, networking, sharing - are leading the development trend of the industry. In this context, the field of wire harnesses will develop in five directions: lightweight, high-voltage, high-speed, platform-based and intelligent.
Automobile wiring harness is the main body of automobile circuit network, and there is no automobile circuit without wiring harness. Automotive wiring harness is mainly composed of wire, connector (connector), protective cover, buckle and so on. The wire is the carrier of the transmission of current, the connector is used to connect different wires and electrical equipment, the protective sleeve can protect the wire from wear and the influence of the external environment, the buckle is used to fix the position of the wire harness. The components of the car wiring harness work together to ensure the normal operation of the car circuit.
Composition of automotive wiring harness
1. Lightweight
1.1 Optimize the architecture and reduce the length of the wire harness
With the transformation of the vehicle network architecture from the traditional distributed architecture to the centralized domain architecture, the harness length is reduced by 50% compared to the traditional vehicle. This optimization not only reduces the weight of the wiring harness, but also reduces the material cost and assembly difficulty.
1.2 Application of new products such as aluminum wire and copper-clad aluminum alloy wire
Aluminum wire because of its density and price is 1/3 of copper, electrical conductivity is 64% of copper, by raising the wire specification 1-2 grades, can achieve replacement, conductor part 50% light, wire cost can be reduced by 40%. Large diameter aluminum wires have been used in batch power lines, and small diameter copper-clad aluminum alloy wires can directly replace the same diameter copper wires, applied in low-voltage wiring harness assembly, the cost of wires can be reduced by 10%.
1.3 Miniaturization of wires and connectors
The signal line can be replaced by a 0.22/0.13/0.08mm² ultra-thin wire, which has been widely used in the joint venture brand. Miniaturized terminals and connectors help reduce the overall size and weight of the harness.
1.4 Research and application of FFC flexible flat cable
Flexible Flat Cable (FFC) Flexible flat cable (FFC) Because of its thin, flexible, flexible and folding advantages, flexible flat cable is widely used in positions with high space requirements, such as ceiling cable harnesses and low-voltage cable harnesses in power battery packs.
1.5 Research and application of electronic fuse box
By replacing traditional fuses and relays with semiconductor chips, the volume of electronic fuse boxes is reduced by about 15%, the weight is reduced by about 20%, and it has the advantages of high reliability, programmable and maintenance-free.
Automotive electrical architecture development trend
2. High-pressure
2.1 Platform design of high voltage connectors
The high voltage system of new energy vehicles usually uses high voltage and high current above 300V, which has higher safety requirements for insulation and protection of connectors. High voltage connector platform design key items include temperature rise and derating curve, high voltage interlock design, protection level, electromagnetic shielding, connector material selection, etc.
2.2 Chip connector
The chip connector has a unique advantage in the field of high current, its contact points are linear, and the contact resistance can be reduced by increasing the width of the contact or arranging multiple contacts side by side.
2.3 High current Busbar
In order to achieve the goal of fast charging, Busbar came into being and can realize automatic assembly, which saves the process of drawing, annealing and twisting compared to cable forming.
2.4 High-voltage harness EMC performance development
High voltage wiring harness to solve the EMC three elements of the "road", using ground filtering and shielding; The high-voltage wire adopts double-layer shielding, and the high-voltage connector adopts shielding ring, shielding spring and other schemes.
High voltage connector development trend
3. Speed up
3.1 Research and application of vehicle Ethernet
In-vehicle Ethernet is a new LAN technology that uses Ethernet to connect the electronic unit in the car, which is mainly used in systems with high bandwidth requirements, such as automatic driving assistance systems (ADAS), in-vehicle diagnostic systems (OBD) and in-vehicle infotainment systems, etc., which can achieve data transmission rates of 100M/s or even 10G/s.
3.2 Special cables and special connectors
The diversity of high-frequency signals on the car brings the diversity of special wire types, such as FM/AM feeders, USB conversion cables, GPS antennas, TBOX antennas, camera cables, fakra coaxial lines, HSD video cables, Ethernet cables, etc. Special wire has the characteristics of high reliability, low electromagnetic radiation, low power consumption, low delay and synchronous real-time technology.
Automotive network development trend
4. Platform design
4.1 Configuring Platformization
Set up basic configurations by configuring combination packages and cover all configurations with the least amount of wiring harness state.
4.2 Principles Platform
The vehicle architecture is divided into subsystems with different functions, and each subsystem gradually realizes the principle platform.
4.3 Interface platformization
Coordinate the interface information of all electrical parts of the vehicle, and establish a database according to the interface solidification of the component end and the wiring harness end.
4.4 Layout Platforming
The wiring harness is divided into different modules according to the vehicle area, and the wiring harness 3D platform-based layout architecture is established according to the platform-based layout principle.
Principle of different sectional layout scheme
5. Intelligence
5.1 Modular design of wiring harness
Wiring harness modular design can be divided into different modules, according to the module development, can quickly achieve the diversification of wiring harness production, to achieve a car line, different vehicles, to meet the individual needs of customers.
5.2 Automation of production line
The promotion of flexible intelligent automated production lines is a strong support for Made in China 2025 and Industry 4.0, and the more important significance is to improve product consistency, improve enterprise production efficiency, and enhance industry competitiveness.
Wiring harness modular design and production
Through these detailed technical introduction and development trend analysis, we can see that the automotive wiring harness industry is developing rapidly in the direction of lightweight, high-voltage, high-speed, platform-based, and intelligent, in order to meet the "new four modernizations" needs of the automotive industry.