The Reduction of Welding Current Asymmetry in Multispot Welding Machines by Differentiating the Cross-Section of Welding Machine Arms

The article discusses the analysis of the propagation of current in resistance multispot welding machines and the adjustment of the cross-section of the welding machine arms aimed to compensate the asymmetry of welding current in individual welds. The analysis involved the effect of the length of multispot welding machines where the span of the arms (distance between welds) amounted up to 2 m, the arms were characterised by various cross-sections and the structural material was characterised by various resistivity (resulting from changes in temperature). The analysis was performed in relation to welding machines using a nominal welding current of 5 kA. The tests made it possible to determine the effect of changes in the value of current on the cross-section of the weld nugget.