Connectors are an important part of the wiring harness for connecting and protecting the wiring harness. To ensure the normal transmission of power and signals, the selection of connectors is critical. The automobile wiring harness connector is an important component used to connect the automobile electrical circuit. Its function is to connect the various circuits in the vehicle electrical circuit to provide a good way for current flow and electrical signal transmission, so as to realize the normal and stable operation of the circuit. In the assembly of the whole vehicle, the connector plays a vital role in it.
1 Electrical properties
The connector is a component used to connect electrical lines, so its electrical performance should be considered first.
Electrical performance mainly considers aspects such as voltage, current, resistance and insulation.
Under normal circumstances, the rated current of the connector is to test its heat resistance performance at room temperature. When the temperature exceeds the set value, it will cause electrical circuit failure. Generally, the rated current is provided in the product manual, which is the highest working current at room temperature. For multi-hole connectors, especially for large currents, the actual selection should be derated according to the number of holes in the connector. In addition, from the perspective of connector contact resistance, the contact resistance measured under the test conditions of low-level contact resistance should be considered for small-signal circuits. For those small-signal circuit connectors that cannot be satisfied by normal tin-plated terminals, consider Use precious metal coatings such as silver or gold to solve.
Finally, for the insulation performance of the connector, it mainly refers to the insulation resistance and insulation dielectric strength. The specific value can be obtained by measurement. It is necessary to make a selection based on the insulating material used in the connector and the working environment.
2 Mechanical properties
The mechanical properties of the connector mainly include insertion force, mechanical life, and the mating force and separation force between the terminal and the sheath, which are higher than 75N in the connector. Therefore, under the premise of ensuring normal power-on, the smaller the insertion force, the better. Mechanical life refers to the number of times it can be plugged and unplugged.
The mechanical life of the general electrical connector is usually 500-1000 times, while the car connector generally meets the requirements of normal conductivity after 10 times of plugging and unplugging, and the conductive performance of silver-plated terminals is normal after 30 times of plugging and unplugging. After the electrical conductivity is normal. The mating force between the terminal and the sheath is affected by the crimping wire diameter of the terminal. When it is less than 1mm2, the mating force is not less than 15N, and when it is larger than 1mm2, the mating force is not less than 30N. The separation force between the terminal and the sheath is related to the size of the connector. For connectors with specifications below 2.8 and above 2.8, the separation force should be greater than 40N and 60N.
3 Environmental performance
Vehicle connectors are widely used, and different parts of the car often have very different environments. Therefore, in the selection of automotive connectors, environmental factors play a crucial reference role. Environmental factors mainly include temperature, humidity, waterproof and dustproof, etc. The ambient temperature is divided into 5 grades, and the test temperature is generally slightly higher than the ambient temperature.
When selecting, first determine the corresponding temperature grade according to the location, and then make the most reasonable choice according to the sheath and terminal material. The humidity of the connector should not be too high, and it is easy to cause a short circuit problem in a humid environment. Therefore, sealed connectors should be used in humid environments.
Different positions on the car have different air humidity and water interference levels, and the required waterproof level is also different. The engine compartment, the chassis and the lower part of the engine, the seat and the bottom part of the door near the chassis should generally choose a waterproof sheath. For parts such as the interior of the cab, doors, and the upper part of the seat, non-waterproof connectors can be considered. Generally, with the improvement of waterproof performance, the dustproof performance will also increase accordingly.
Post time: Sep-30-2022