What are the factors to cause unstable welding production? Gap between sheets is one of the causes. Understanding the effect of the gap would help to improve production stability and weld quality consistency. Here we present an idea to find optimal parameters for welding sheets with gaps.
The gap between sheets could happen due to alignment errors or stamping tolerances. When the sheets with gaps are spot welded, the gaps can lead to early splash or no weld.
The effect of gap on the weld lobe
We ran a set of simulation with different gaps (no gap, 0.2mm, 0.5mm, & 1.0mm) to investigate their effect on the weld lobe. The material used in this simulation is DP600 in 1.0mm. The AC machine is selected and weld time is set to 8 cycles. The weld lobes are generated by SORPAS 2D.welding v14.4.
By comparisons of weld lobes with different gaps simulated by SORPAS® 2d.welding, we can see the gap between sheets has significant effect on splash limit.
- To get a stable production, choose optimal parameters in the overlapped area of the lobes covering all possible gaps.
- In general, the process window is larger with higher force. But it should be compromised with consideration of electrode life.