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Suggestions for Improving the Quality of Automotive Wiring Harnesses

Suggestions for Improving the Quality of Automotive Wiring Harnesses

2020/02/08 10:15:46

Automotive Wire Harness is composed of wires, connectors, and wrapping tape. It is an important component that connects various electrical and electronic equipment in the car, and is the main body of the network of the car circuit. With the increase of automotive electrical systems directly leading to the increase in terminal appliances, signal transmission capabilities have also been challenged. The solution is to increase the wire loop, which inevitably increases the number of wires, connectors, sensors, etc., and the weight and volume of the circuit harness has reached the range that the car cannot bear. Therefore, improving the signal transmission capability and reducing weight of automobile cable harnesses is the development direction of automobile circuit harnesses.

Automotive Wire Harness

Automotive Wire Harness

1. Analysis of common failure causes of automotive circuit wiring harness

The product design development process and production process of automotive circuit wiring harnesses will affect the quality of the wiring harnesses. The following analyzes the common faults and causes of automotive circuit wiring harnesses:

(1) When a vehicle presses the accelerator pedal, the accelerator does not respond, the vehicle speed cannot be increased, the engine shakes and black smoke is emitted from the exhaust pipe. It is determined that the wiring harness is in poor contact. After replacing the engine wiring harness, various faults are eliminated. After investigation, it is because the internal terminal of the engine ECU connector in the engine harness is poorly crimped, and the copper wire leaks out and contacts the terminals in adjacent holes, causing the short circuit and causing the above-mentioned failure. The first reason is the short circuit of the wiring harness. Second, the root cause is that the production process of the wiring harness is not well controlled, and the terminals are not crimped properly.

(2) During the test of a test vehicle, the vehicle suddenly fails to start, the key is in the ON position, and the EMS main relay does not engage. After investigation, it was because the wiring harness was unreasonably arranged, interfered with the peripheral parts, the protective layer of the wiring harness was worn out, and the circuit power wire of a wiring harness was grounded, which caused the above-mentioned failure.

2. Suggestions for improving the quality of automotive circuit wiring harnesses

(1) Wire inspection. Among the raw materials used in automotive circuit wiring harnesses, wires are used the most, and the entire manufacturing process and operation process of wiring harnesses involves wires, so the quality control of wires is the most critical. The main parameters and performance indicators of the wire are: appearance structure, initial elongation, high temperature aging elongation, high temperature resistance, cold bending resistance, flame resistance, oil resistance, abrasion resistance, and extrusion resistance. Wire parameters of different standards, such as structure size and insulation layer material and thickness, are different. The purpose of controlling the appearance structure is to control the wires to meet the corresponding standards and color requirements. When a certain performance index of the wire does not meet the requirements (failure), the related performance of the wiring harness will decrease.

(2) Connector inspection. Automotive connectors (including terminals and jackets) are the most basic unit of a wiring harness and the core of reliable electrical signal transmission and connection. It can also be said that a wiring harness is a connector connected by a wire, and it can be seen that the quality of the connector is important to the quality of the automobile circuit wiring harness.

(3) Inspection of rubber parts. The electric wire passes through the hole of the rubber part and fits tightly with the hole. The rubber part is externally threaded and installed on a hard plastic or metal part to play a fixing role. This not only fixes the wires and rubber parts together, but also prevents rain and oil from leaking. The design tension of the elastic connection in the middle to the outside forms a certain damping characteristic, which can greatly reduce the vibration damage during movement and protect the circuit. When designing a good rubber part, you should consider insulation, strong internal and external fit, excellent elasticity, excellent aging resistance and ozone resistance. This shows the importance of rubber parts in automotive wiring harnesses. The full performance test of rubber parts includes hardness, breaking strength, breaking elongation, hardness change, breaking strength change and breaking elongation change.

The above is the relevant information introduced by Wire Harness Factory to improve the quality of automotive wiring harnesses. Hope to help you.