Current Distribution Monitoring in Capacitor Discharge Welding

• Published in: 2020 25th IEEE International Conference on Emerging Technologies and Factory Automation (ETFA) Vol. 1; pp. 447 - 453
• Main Authors: Meiners, Moritz, Reichenstein, Tobias, Franke, Jorg, Hauenstein, Rainer
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.09.2020
• Subjects: capacitor discharge welding; Capacitors; current distribution monitoring; Electric potential; hall effect sensor; Heating systems; Process control; Process monitoring; resistance welding; sensor system; Thermal resistance; Welding
• ISSN: 1946-0759
• DOI: 10.1109/ETFA46521.2020.9212054

The capacitor discharge welding (CDW) is a resistance welding process that excels through brief process times, low thermal stress, and good automation potential. Nevertheless, potential industrial users hesitate to use the CDW process, owing mainly to the unavailability of automated process control to ensure cost-efficient production and high product quality. For quality assurance, representative values or process curves of the most critical process parameters such as capacitor energy, contact force, electric current, and sink-in depth are monitored. The lack of full significance of this monitoring is indicated by the regular destructive testing of random samples through load tests and cross-section analysis. The essential aspect of the process quality is heat development in the welding zone. The current distribution, as one crucial parameter influencing heat development, is missing. Therefore, this paper presents an in-situ qualitative, indirect current distribution measurement system. The new measurement supplements the process monitoring and analysis, and thus, gain new process knowledge. With better process monitoring and thus understanding, new application areas can be developed for CDW.