Method and arrangement for automatic build-up welding

摘要

The invention relates to a method and an arrangement for automatic build-up welding which permits material build-up up to a preselected layer thickness irrespective of the local degree of wear of a workpiece. According to the invention, the welding torch is guided parallel to the required workpiece surface, and the feed rate of the welding torch is controlled by a signal which corresponds to the difference between the desired height of the build-up weld and the instantaneous value reached. The signal itself is obtained from the arc. The setting values for the welding current and the welding voltage are readjusted for constancy during the welding of a layer after they are set, and the instantaneous working point is detected by simultaneous current/voltage measurement. The deviations from the predetermined straight working lines are analysed by division and subtraction, after which an absolute-value adjustment is made. The analogue information signal available, of positive or negative sign, is used to control the feed rate of the welding torch in the welding direction. Parameter fluctuations due to the equipment technology are compensated for in the process by changing the distance.