Adaption of the ultrasonic welding technique to the process of joining insulated copper wires with standardized tubular cable lugs

Within the manufacturing of electric drives, the joining of resin insulated copper wires with standardized tubular cable lugs has to be seen as an important manufacturing step, as this process is one major reason for drive malfunctions - especially in case of mobile devices. Currently, the thermo-crimping technique is commonly used, because it combines high process stability with short tact times. However, the thermo-crimping tools show strong wearing within short periods, as the required heat to skin the insulated copper wires has to be supplied from the electrodes themselves. Therefore, the electrode materials have to face simultaneously high pressures and temperatures up to 650°C, resulting in highly frequent setup processes and corresponding costs. For this reason, a new technique to join insulated copper wires with cable lugs, based on the ultrasonic welding procedure, was investigated at the department FAPS. The following paper describes the explored results regarding the technique of ultrasonic welding. Hereby, the new technology is compared with the thermo-crimping process concerning the joint quality, tact time and tool wearing.