Will spot welding machine weld more points firmly?

In metal welding, when welding with a resistance spot welding machine, firm welding is a basic requirement. From a simple image, it seems that the more welding points, the stronger they are. Therefore, some people will say no, so they will weld more points, which must be firm. In fact, it is biased. In multi-point welding, there is a requirement for the spacing of the solder joints, and the closer to this requirement, the stronger the multiple solder joints. If the solder joint spacing does not meet the requirements, it may be counterproductive. The more irregular the spacing of the solder joints, the more irregular the quality of the solder joints may deteriorate.

The main reason for this problem is the shunt phenomenon of the solder joints. When the point distance is too small, it is easy to produce shunt, resulting in insufficient heating of the welding area. In spot welding, the current passing through the non-welded area is called shunt. The solder joint shunt is related to the material resistivity and conductive path of the welding workpiece. In fact, each weld formed by welding is a current path. When the spot welding machine is used for welding, one place is after formation, and the other is the adjacent area during welding. The resistance in the first place is much lower than the welding area, that is to say, the resistance in the second position is greater, and the current will flow from the first position, so the quality in the second position is lower than that in the first position.

The smaller the distance between the two solder joints, the worse the quality of the solder joints welded later. If the spacing is too small, the shunt is large enough and may even affect the formation of the next solder joint.

Therefore, in the welding work of spot welders, when multiple welding points need to be welded, the welding point spacing must be designed to meet the requirements, otherwise the welding effect will be affected. According to the size of the welding spot, welding material, workpiece geometry, different welding methods (collision, parallel), different welding head structures, etc., the appropriate spacing range is different and should be evaluated according to the actual situation.

At the same time, it should be noted that when using AC spot welding machine, the influence of welding spot spacing on welding quality is greater than that of DC spot welding machine with high frequency inverter, because the current is not concentrated enough, the welding time is long, and the shunt will be more serious.