Abstract: A method for butt-welding of sheet metal, especially bodywork in the motor vehicle industry, where at least two flat workpieces with any desired contours are fed to a machining process. In a first sub-process, the workpieces are positioned in relation to one another forming a minimal gap and secured in place with holding means. In another sub-process, the position and width of the gap are measured continuously immediately before welding together and the measurements are used to control a laser welding head. The laser welding head is fit with a rotatable twin-spot lens, where the relative alignment of a main spot to an auxiliary spot is controlled depending on the absolute position of the gap and the gap width during the welding process while the processing lens of the laser welding head is rotated around the laser beam axis with the angle of rotation alpha.

Abstract: To increase cycle time, and therefore to lower production costs, in the industrial production of welded sheet metal parts—in particular tailored blanks for the automotive industry—the invention describes a method based on a constant-speed conveying system and a flying optics system, which method manages without complex cooling of the hot weld seam and uses means for holding the workpieces on one side with a high force on the conveyor belt. In this way it is possible greatly to reduce the negative influence the blank spacing has on the cycle time of the machine. Overall, fewer drives are required in the machine and it is possible for a simplified machine concept to be employed without detriment to the quality of the blanks to be welded.