Automotive Connecting cables Reliability Design

At present, modern science and technology have been effectively improved, and the automobile industry has also developed rapidly and become an indispensable part of people’s lives. At the same time, the electrical equipment inside the car can connect every electronic component. Wiring harness design plays an important role in automobile circuits, otherwise the functional requirements of the automobile cannot be met. Because of the improvement of automobile performance and the continuous application of new functions, different needs of automobiles can be met. As the internal structure of cars becomes more and more complex, the installation, maintenance and wiring of electrical appliances become more difficult. The weight that the crossbeam needs to carry will also increase with the increase in collar parts, thus reducing the reliability of the vehicle. This article analyzes the system design of automobile wiring harness and the selection of relevant raw materials, in order to provide a reference for the reliability of automobile wiring harness design.
Automotive wiring harness layout design and principles:
Designers must fully consider the distribution and attribute characteristics of the vehicle’s electronic equipment when designing the wiring harness layout. The wiring harness can be roughly summarized into: front cabin wiring harness assembly; engine wiring harness assembly; instrument wiring harness assembly; floor wiring harness assembly; door wiring harness assembly; ceiling wiring harness assembly; battery wiring harness assembly, etc.

Reliability design of automobile onnecting cables

(1) The wiring harness assembly is easy to install
When designing automotive wiring harnesses, different design forms should be adopted for wiring harness design according to different regions. Usually “H type” and “E type” arrangements are used. The diameter of the metal port must be larger than the diameter of the largest outer component passing through the port. If it cannot be reached, the wiring harness cannot pass. The configuration of the automotive wiring harness should minimize adding too many steps to the assembly of the entire vehicle, because their planned locations are different, so the required structures are also different. In order to facilitate installation, designers need to prepare at least two or more solutions when formulating the solution, and study the actual possibilities, advantages and disadvantages of each solution to determine that the structure can solve the automotive circuit requirements.

Automotive Connecting cables layout design

(2) The wire harness fixing structure is easy to assemble
The assembly process of the components must be fully considered when designing the wiring harness fixation mode and structure. The reliability of the components should be sought without excessive increase. Simple especially in places where the space is very narrow, such as the side lines inside the doors, body and interior trim lines, and since space is limited, maximize the use of plastic clips or adhesive tapes. When designing the fixed wiring harness structure and related functions, the perforated rubber clip must be completely installed in the metal plate hole, and the installation force does not exceed 100N. In this case, normal standard components should be designed to use standard component types wherever possible and minimize the use of special tools for assembly and maintenance through early design.

Selection of automotive wiring harness raw materials

(3) Good maintainability
When a fault occurs in the power system, the fault is eliminated in the shortest possible time and prevents the fault from causing damage to other components. For the convenience of later maintenance, when there are many connectors in the car, careful consideration should be given to the fixed position of the circuit. If necessary, wire harness slots or wire harness brackets can be added, and the exposed parts can be protected with corrugated tubes, so that there are gaps between each area to avoid unnecessary interference with parts. At the same time, the wiring harness layout needs to avoid high-temperature areas, and the gap distance must be at least 160 mm. If high-temperature components cannot be avoided, a heat shield needs to be added to protect the wire harness so as not to cause additional conflicts with the system and ensure the convenience of wire harness maintenance.

Reliability analysis of automobile wiring harness system

Selection and aesthetic design of automotive wiring harness raw materials:
(1) Selection of automotive wiring harness raw materials
Designers must fully understand and respect the principle issues of circuits in automotive circuit design, such as whether to select wires that match the color during the selection process, because choosing the correct color wire can minimize the occurrence of errors. . At the same time, the appropriate cross-sectional area should also be selected, and the shortest distance must be selected for connecting the wires. The ultimate goal is to correctly install the wires on both sides of the connector, so that the overall wiring harness design of the car can be better analyzed and studied.

The most important part of the design is the selection of fuses and wiring harnesses. We know how critical it is to choose the right raw materials when designing a car. Fuses are protective components of automobiles. Its operating principle is to protect electronic equipment during use. If the fuse is unreasonably selected, it will not be able to melt immediately at the predetermined current value, and the purpose of protecting the electrical appliance will not be achieved. At present, most cars are composed of low-voltage wires containing vinyl resin insulation, or thin-walled low-voltage wires for automobiles, which can be convenient for operators to assemble, and subsequent maintenance and replacement will be simple and easy.

(2) Beautiful design of automobile wiring harness
No matter what principles need to be followed or what materials are selected for automobile wiring harnesses, the most important thing is to let nature take its course, the wiring cannot be too far-fetched, and on this basis, add beautiful design. The wiring harness direction needs to be in the same direction as the area where the electronic equipment is located. Try to study the horizontal, vertical and horizontal methods and avoid using oblique designs to save materials. If the wiring harness is found to be too messy during the layout, it is recommended to use wiring harness guards reasonably in this part. In the design plan, the overall components of the car need to be comprehensively considered, and potential risks should be avoided as much as possible before starting, combined with the wiring harness layout, to provide greater room for later manufacturing and assembly. In this regard, designers should rationally arrange the wiring harness direction, so as to choose the best method to ensure the operating performance of electrical appliances.

Reliability analysis of automobile wiring harness system:
Our country has always supported the implementation of promoting reliability and invested a lot of energy in research in order to better improve reliability. The improvement of automotive wiring harness reliability is mainly carried out from 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. They are key components of the automotive wiring harness system and are of great significance in the wiring harness system. Damage to the wiring harness system is mostly caused by problems with the terminals and connectors. For example, the terminals appear to be aging, and the connectors have become loose or damaged due to too long time, and other problems. In normal times, this problem is a very small detail, but it will directly affect the reliability of the wiring harness system. Therefore, in the wiring harness design, how to effectively improve the reliability of the segment needs to be completed through a series of measures. It is worth noting that it is very important to choose the appropriate connectors and plug-ins, and you need to pay attention to the temperature of the connector, as well as the maximum current it allows to pass, especially the working environment and working temperature. The most important thing is to effectively prevent damage to terminals and connectors caused by corrosive gases and liquids.

(2) Wiring harness protection reliability
Designers need to analyze the reliability of wire harness protection from an integrity perspective. It is therefore necessary to develop a series of reliability measures. During the selection process, packaging materials must undergo detailed and integrated testing. Then materials with the highest integrated performance are selected, the specific content of each link is randomly checked, and unqualified products are removed. Wire harness fixation design generally uses cable ties, clips and bracket guards. Their main function is to fix the direction of the wiring harness, reduce friction, and avoid safety hazards.

Cable ties are the most commonly used material for fixing directions, and most of the fixings are done using cable ties. We often use Japanese-style belts made of P66 material, long-lasting universal lift-type, T-type, plug-in connectors, pipe clamps, etc. Generally used in places where space is small and holes cannot be drilled. Compared with the above two, the bracket guard is less usable and generally has a higher manufacturing cost. The structural shape of each car is different, so the bracket guard design will also be different. In order to better enhance the reliability of wire harness protection, each type of material used to fix the wire harness has room for optimization. While designers are improving the wiring harness plan, they can further study the quality of fixed wiring harnesses to reduce costs and improve economic benefits.

(3) Reasonable layout and reliability
Reasonable configuration and distribution can improve the structure and reliability of the wiring harness. Reasonable configuration can effectively optimize the complexity of wire harness design and avoid many risks in wire harness manufacturing and installation. During the installation and testing process, the size and diameter of the wire harness are optimized through reasonable configuration and improved humaneness. Good design affects the reliability of the entire vehicle system.

However, before placement, the length of the wiring harness is determined based on the actual configuration of the electrical appliances on the vehicle. In the design, if the length of the wire harness is too long, it wastes space and material to make the wire harness vertical, causing the vehicle to collide with the metal plate and causing friction 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 spread throughout the organization structure and are called the “nerves” of the car. It has a direct impact on the safety and comfort of automobile use. Therefore, automotive wiring harnesses have very high requirements for design and selection of raw materials. During the wire harness design process, it is necessary to carry out targeted design of lines, connectors, wires and wire harness wrapping and fixation based on the working conditions and functionality of the wire harness to improve the feasibility of the design. Ensure the maximum adaptability of the wiring harness raw materials and the working environment to ensure the stability and reliability of the overall performance after the car is put into use.