Factors Affecting the Transmission Capacity of Automobile Connector Terminals and Prevention Methods (3)

4. Positive pressure of terminal shrapnel

The positive pressure of the connector terminal refers to the force generated on the contact surface of the connector plug terminal and the socket terminal and perpendicular to the contact surface, and it is an important index that affects the performance of the connector. This factor directly affects the insertion force and electrical performance of the terminal.

In the process of using the terminal, the main problem is that the insertion force control between the terminal and the terminal are unstable. The reason is that the positive pressure of the terminal shrapnel is unstable, resulting in an increase in the resistance of the terminal contact surface, resulting in an increase in the temperature rise of automotive terminals, causing ablation of the connector and loss of conductive function. Increased and burned cars and other serious consequences.

The positive pressure of the terminal mainly affects the contact resistance of the connector. According to the QC / T417 regulations, the contact resistance refers to the resistance value between the contact points of military grade electrical connectors. It includes the inherent resistance of the terminal, the resistance generated by the conductor crimping, the resistance of the reference point wire, and the resistance generated by the contact between the plug terminal and the socket terminal spring.

The inherent resistance is mainly determined by the terminal material, the crimping resistance is controlled by the crimping quality of the product, the resistance of the reference point wire is determined by the wire itself, the resistance generated by the contact between the plug terminal and the socket terminal spring, the conductive characteristics of the terminal The temperature rise value has a serious influence and should be considered in the design.

The positive pressure of the terminal depends on the elasticity of the terminal spring tongue. This value is directly affected by the bending radius R and the cantilever length L of the spring tongue. Special attention should be paid during the design process.

5. Tail crimping

The crimping quality directly affects the transmission quality of the terminal. The crimping engagement length and crimping height have a great influence on the crimping quality. The mechanical strength and electrical performance of tighter crimping is better than that of looser crimping, so the size of the crimping section should be strictly controlled.

There are many factors that affect the crimping effect of terminals and wires. Any type of terminal has a certain range of wire diameter, and the wire diameter is an important factor that affects the quality of crimping.

Secondly, the wire itself is also worth studying. The products at home and abroad have different characteristics. In actual production, the following principles should be followed:
1. The wire diameter of the wire should conform to the tail of the terminal
2. The length of the wire stripping part should be moderate
3. Choose the right crimping mold
4. After the crimping of the terminal, a test shall be carried out

The crimping method of the inspection terminal is to inspect the crimping profile of the terminal and the pull-out force of the terminal. The profile can intuitively judge the effect of crimping. The crimping result must not have defects such as copper leakage and bottoming. The pull-off force can judge the reliability of crimping.

Through the above analysis of the factors of the electrical performance of the terminal, it is not difficult to see that there are many factors that affect the electrical performance of the terminal, including the material selection in the early stage of the design, the rationality of the structural design, and the subsequent product crimping. Therefore, in the design process of such products, the problem should be analyzed from multiple angles to find the optimal design plan.

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