Method for manufacturing powder-filled tubular welding electrodes and a device for performing the method

摘要

A method for manufacturing powder-filled tubular welding electrodes made from a continuously fed metallic gutter (16) in which the powder is introduced through a powder conveyor (17) opening in the gutter, which conveyor via a filling conduit (19) arranged inside the gutter will transfer the powder past a welding station (23) for welding the longitudinal edges (25) of the gutter which is formed to a tube (21). The purpose of the invention is to provide a method and a device for manufacturing powder-filled tubular welding electrodes without the powder damaged when it passes the welding station and that the filling of a tube is made under controlled conditions thus that the tube is completely filled concurrently with its feeding through the welding station. This has been solved thereby that a pressurized gas is introduced in the filling conduit (19) for accelerated transport of the powder through the conduit, and that the pressurized gas is evacuated through an evacuation duct (31) provided in the tube (21) the inlet (30) of said duct governing the feeding of the powder, therein that the inlet at too big a powder volume is blocked by the powder, whereupon a counter pressure will be achieved in the filling conduit causing the powder feed to be reduced or completely prevented.