Ultrasonic crimping technology of automotive high-voltage wire harness terminals

In order to shorten the charging time of the power battery of new energy electric vehicles, electric vehicle manufacturers urgently need to improve the ability of each circuit in the DC fast charging system to carry high voltage and large current, which relies on cables with large current carrying capacity. Therefore, wire harnesses with large cross-sectional areas are widely used to load larger currents, and at the same time have good heat dissipation performance, which is the most effective method to improve the charging efficiency of electric vehicle power batteries.

In the near future, the current-carrying capacity of high-voltage wiring harnesses for electric vehicles will be four to five times that of existing ordinary electric vehicle cables. In terms of wire harness size, if copper is selected as the conductor material, the required cross-sectional area of the automotive wire harness will increase from 50mm² to 200mm² or even higher.

However, how to reliably connect these larger cross-section cables is a major technical challenge for automakers. At the same time, the rapid update and iteration of electric vehicles has also brought about the exploration of technical points such as how to arrange and accommodate these cables, cable lengths, and low internal resistance connection processes inside the car. Ideally, the cable length should be as short as possible to obtain the performance of low internal resistance and low temperature rise. However, it is usually impossible to shorten the cable length inside the actual electric vehicle, so the cable diameter needs to be increased accordingly to ensure low internal resistance and good heat dissipation. As more and more battery modules are placed under the vehicle, larger cross-sectional wire harnesses or conductors need to be installed and routed around and under the passenger compartment. Therefore, the body structure must not only be insulated from cables and conductors, but must also safely dissipate the temperature rise that occurs in the wiring harness during fast charging.

In order to solve the above problems, Saichuan Electronics has introduced advanced ultrasonic welding equipment, which has a higher welding pressure, which can reach 6100N, and acts vertically on the wire harness to be welded; colleagues have a lower welding amplitude, which can improve welding with high energy. The slip phenomenon and the damage to the surface of the wire harness caused by the large amplitude. Soldering applications of high-voltage harness connectors can be easily handled to achieve excellent soldering quality.

The equipment is equipped with higher precision pressure sensor and displacement sensor, which can detect and control the welding process more accurately. The high-voltage wire harness terminal welding workstation is equipped with a terminal clamping tool specially designed for welding, which can firmly fix the workpiece to be welded, ensure the stability of the welding process, and finally provide customers with an efficient and reliable high-voltage wire harness welding solution.