Design principles of spot welding heads

The spot welding head process is to use solder joints to connect two or more sections of equal thickness or unequal thickness to form a joint. Spot welding heads generally use lap joint and flange joints.When designing the structure of a spot welding head, it is necessary to consider the reachability of the electrode, the margin, the amount of overlap, the assembly gap of the parts, the spot distance, the indentation and the indentation, the different plate thickness, the strength of the solder joint, etc.

1.The reachability of the electrode means that the electrode must be able to easily reach the welding part of the component. Because the shape of the weldment is different from the welding position, in order to obtain a satisfactory welded joint, the accessibility of the electrode must be considered, otherwise, the welding cannot be carried out at all.

2.Margin refers to the distance from the center of the nugget to the edge of the plate. The base metal at this distance should be able to withstand the pressure generated by the inside of the nugget during  the welding cycle. The smaller margin is related to the composition and strength of the base metal, the thickness of the section, the shape of the electrode surface and the welding cycle.

3.The overlap of the joint allows the smaller overlap of the joint to be twice the margin. However due to the influence of certain factors, it is necessary to increase the amount of overlap. If the overlap is too small, the margins must be insufficient.