As a key component of automotive electronic systems, the design and manufacturing process of automotive wiring harnesses directly affect the normal operation of the entire automotive electrical system. The development of electronics and information technology has put forward increasing requirements for the design and manufacturing process of automotive wiring harnesses, especially the quality of transmission signals. Therefore, simply using shielded wires, twisted pair cables, and gold-plated terminals in the production of automotive wiring harnesses is far from meeting these requirements. In fact, ultrasonic welding technology is also the main measure to improve the quality of transmission signals and currents.
Ultrasonic welding machines are mainly used to weld wire harnesses at large areas. Combine multiple or single stranded copper wires of different sizes together. Initially, crimping was done using a terminal machine. Long term use not only consumes the terminals, leading to unstable quality, but also affects the quality of the vehicle wiring harness. Nowadays, new energy vehicles use ultrasonic welding of car wiring harnesses.
1、Welding principle
The principle of ultrasonic welding for automotive wire harnesses is to weld the wire harness through high-frequency mechanical vibration. During the welding process, three directions are simultaneously tightened to the ultrasonic welding end face and subjected to cyclic vibration at a frequency of 20kHz on its surface. At the same time, apply pressure to the workpiece to form a strong bond between them, thereby achieving the welding effect. The entire welding process can be effectively controlled without generating excess heat on the metal surface, resulting in strong welding stability.
2、Welding precautions
When ultrasonic welding car wire harnesses, relevant parameters need to be set, such as wire cross-sectional area, pressure, welding spacing, amplitude, energy, etc. During the welding process, the wires should be arranged vertically overlapping, and large cross-sectional lines should be placed below the welding head to ensure sufficient welding; Welding wires should be placed close to the surface of the anvil and tightly connected to each other to ensure sufficient strength after welding; The length of wire overlap is usually set to 13-15mm. If the overlap length is too short, it is difficult to ensure welding strength. If the overlap length is too long, the welding end is prone to curling, which is not convenient for the next process operation. The surface of the welded joint shall not have oxidation, wire breakage, defects, or melting of the insulation layer.
3、Welding advantages
High fusion strength, superior conductivity after welding, and extremely low or almost zero resistance coefficient;
Short welding time, greatly improved efficiency, fast and energy-saving;
No gas, solder, or flux required;
Improving welding quality ensures the reliability of product conductor performance.
