Design and Principles of Automotive Wiring Harness Layout

When designing the wiring harness layout, designers should fully consider the distribution and attribute characteristics of the vehicle's electronic equipment. The wiring harness can be roughly divided into: front cabin wiring harness assembly, engine wiring harness assembly, instrument wiring harness assembly, floor wiring harness assembly, door wiring harness assembly, roof wiring harness assembly, battery wiring harness assembly, etc.

(1) Easy installation of wiring harness assembly

When designing the configuration of automotive wiring harnesses, different design forms should be adopted according to the different regions, usually using "H-shaped" and "E-shaped" layouts. The diameter of the metal port must be greater than the maximum external component diameter passing through the port. If it cannot be reached, the wire harness cannot pass through. The configuration of automotive wiring harnesses should minimize the addition of too many steps in the assembly of the entire vehicle, as their planned positions and required structures are different. For the convenience of installation, designers need to prepare at least two or more schemes when formulating the plan, and study the actual possibilities, advantages and disadvantages of each scheme to determine whether the structure can meet the requirements of automotive circuits.

(2) The wiring harness fixing structure is easy to assemble

When designing the wiring harness fixing mode and structure, it is necessary to fully consider the assembly procedure of the components. In the absence of excessive increase, the reliability of the components should be sought. Simple, especially in narrow spaces such as side lines inside car doors, body and interior decoration lines, and due to limited space, plastic clips or adhesive tapes must be used to the maximum extent. When designing the fixed wiring harness structure and related functions, perforated rubber clips must be fully installed in the metal plate holes, with an installation force not exceeding 100N. In this case, normal standard components should be designed to use the type of standard components as much as possible, and the use of special tools for assembly and maintenance should be minimized through early design.

(3) Good maintainability

When a fault occurs in the power system, eliminate the fault as quickly as possible and prevent damage to other components caused by the fault. For the convenience of later maintenance, when there are many car connectors, the position of the fixed circuit should be carefully considered. If necessary, wire harness slots or wire harness brackets can be added, and the exposed parts should be protected with corrugated pipes to leave gaps between different areas and avoid unnecessary interference from parts. At the same time, the wiring harness layout needs to avoid high temperature areas, with a minimum gap distance of 160 millimeters. If it is not possible to avoid high temperature components, a heat shield needs to be added to protect the wiring harness from additional conflicts with the system, ensuring the convenience of wiring harness maintenance.

Selection and Aesthetic Design of Automotive Wire Harness Raw Materials

(1) Selection of raw materials for automotive wiring harnesses

In automotive circuit design, designers must fully understand and respect the principles of the circuit, such as whether to select wires that match the color during the selection process, because choosing the correct color of wires can minimize the occurrence of errors to the greatest extent possible. At the same time, a suitable cross-sectional area should be selected, and the shortest spacing must be chosen for wire connection. The ultimate goal is to correctly install wires on both sides of the plug connector, which can better analyze and study the overall wiring harness design of the car.

The most important aspect of design is the selection of fuses and wiring harnesses, and we know that choosing the right raw materials is crucial in automotive design. Fuses are protective components of automobiles, and their operating principle is to protect electronic devices during use. If the fuse selection is not reasonable, it will not be able to immediately melt at the predetermined current value, and it will not achieve the purpose of protecting electrical appliances. At present, most cars are composed of low-voltage wires insulated with vinyl resin or thin-walled low-voltage wires, which can be easily assembled by operators and have simple and easy maintenance and replacement in the later stage.

(2) Aesthetic design of automotive wiring harness

Regardless of the principles to be followed or the materials selected for the production of automotive wiring harnesses, the most important thing is to let nature take its course. The wiring should not be too forced, and aesthetic design should be added on this basis. The routing of the wiring harness should be in the same direction as the area where the electronic device is located, and a horizontal and vertical straight approach should be pursued as much as possible to avoid using diagonal design to save materials. If the wiring harness is found to be too messy in the layout, it is recommended to use wiring harness protective plates reasonably in this part. In the design scheme, it is necessary to comprehensively consider the overall components of the car, and combine the wiring harness layout to avoid potential risks as much as possible before the start, providing greater space for later manufacturing and assembly. Point it out, the designers should arrange the wiring harness direction reasonably, so as to choose the optimal method to ensure the operational performance of the electrical appliances.

Reliability analysis of automotive wiring harness system

China has always supported the implementation of promoting reliability and has invested a lot of effort in research to improve its reliability. The improvement of the reliability of automotive wiring harnesses mainly focuses on the following aspects:

(1) Reliability analysis of terminals and connectors

One of the main components of the reliability of the wiring harness system is the terminals and connectors, which are key components of the automotive wiring harness system and have significant importance in the wiring harness system. The damage to the wiring harness system is mostly caused by problems with the terminals and connectors, such as aging of the terminals and other issues such as looseness or damage in the middle of the connectors due to prolonged use. This issue is usually a minor detail, but it directly affects the reliability of the wiring harness system. So, in the design of wiring harnesses, it is necessary to take a series of measures to effectively improve the reliability of segments. It is worth noting that choosing the appropriate connectors and plugins is very important, and attention should be paid to the temperature of the connectors, as well as the maximum current allowed to pass through them, especially the working environment and temperature. The most important thing is to effectively prevent corrosive gases and liquids from causing damage to the terminals and connectors.

(2) Reliability of wire harness protection

Designers need to analyze the reliability of wire harness protection from the perspective of integrity, so it is necessary to develop a series of reliability measurements. In the selection process, packaging materials must undergo detailed and integrated testing, and then select the material with the highest integration performance, sample and inspect the specific content of each link, and remove non-conforming products. Wire harness fixing design generally uses cable ties, clamps, and bracket guards, etc. Their main function is to fix the direction of the wire harness, reduce friction, and avoid safety hazards.

Cable ties are the most commonly used material in fixed routes, and most of the fixing is done by using them. We often use Japanese style straps such as P66 material: long pull universal lifting type, T-shaped, plug-in connectors, pipe clamps, etc. Generally used in small spaces and areas where drilling is not possible, the bracket guard plate has poorer usability compared to the above two, and generally has higher manufacturing costs. The structural shape of each car is different, so the design of the bracket guard plate will also be different. In order to better enhance the reliability of wire harness protection, there is room for optimization for each type of material used to fix the wire harness. While improving the wire harness scheme, designers can further study the quality of the fixed wire harness, reduce costs, and improve economic benefits.

(3) Reasonable layout reliability

Reasonable configuration and distribution can improve the structure and reliability of the wiring harness. Reasonable configuration can effectively optimize the complexity of wiring harness design and avoid many risks in wiring harness manufacturing and installation. During the installation and testing process, optimizing the size and diameter of the wiring harness through reasonable configuration and improving human experience, good design affects the reliability of the entire vehicle system.

However, before installation, the length of the wiring harness is determined based on the actual configuration of the electrical appliances on the vehicle. In design, if the length of the wiring harness is too long, it will waste space and materials, making it impossible to make the harness vertical, resulting in collisions between the vehicle and the metal plate, and friction will produce sound when moving. Due to the above reasons, the actual fixing strength of the wire harness should be increased, which will help improve the reliability of the wire harness and provide a good foundation for the actual assembly process in the later stage.

conclusion

Automotive wiring harnesses are distributed throughout the structure, known as the "nerves" of automobiles, and have a direct impact on the safety and comfort of car use. Therefore, automotive wiring harnesses have very high requirements for design and the selection of their raw materials. In the process of wire harness design, targeted design of circuits, connectors, wires, and wire harness wrapping and fixation should be carried out based on the working conditions and functionality of the wire harness, in order to improve the feasibility of the design, ensure the maximum adaptation of wire harness raw materials to the working environment, and ensure the stability and reliability of the overall performance of the vehicle after it is put into use.