Optimization of Cutting Condition for Spot Welding Electrodes

Abstract

Currently, spot welding must satisfy requirements not only on weld strength but also on dust control. A study made last year succeeded in using energy evaluation to calculate welding coriditions that were robust under different machining conditions. The present study extends this functionality (energy evaluation) to the optimization of peripheral devices. Repetitive welding degrades the end of a spot weld electrode, lowering the energy supplied through the end to the base material. The end is therefore periodically recut and renewed with a chip cutter, but this process is not entirely beneficial: the dimensional accuracy target tends not to be obtained, resulting in variations in weld quality. Parameter design was therefore enlisted to optimize the electrode cutting conditions,and two orthogonal array experiments were conducted, from which a high gain and reproducibility were obtained. A feature of this study is that the results were evaluated not from the power consumed by the cutter motor, but by carrying out the welding process using the renewed electrodes, and evaluating the change in cumulative energy supplied to the material being welded.