| 摘要 |
A combined laser and plasma-arc welding torch, which joins features of separate laser and plasma-arc welding devices in a single tool. A laser beam is directed by an optic system to be co-linear with the central axis of a plasma-arc torch. The laser beam passes through a group of electrodes, whose longitudinal axes are disposed at acute angle to the torch central axis on the generatrix of a cone, the apex of which lies on the torch central axis close to the section plane of a constricting nozzle, and the base of which faces the main body of the torch. The distance between the central axis and the closest point of the electrode is less than the laser beam radius in a section which is perpendicular to the central axis and passes through this closest point. The distal ends of the electrodes are provided with heat accumulating bulbs and mechanism for individual protection by delivering a separate gas. The electrodes may be cathodes both, anodes, or, cathodes and anodes. The welding torch may be additionally provided with a mechanism for additional constricting and stabilization of a plasma jet. Such a mechanism includes grooves arranged on the conic outer surface of the constricting nozzle and also on the opposite conic surface, which is immediately adjacent or spaced from the constricting nozzle surface. Gas is forced through a chamber having the electrodes and nozzle at the chamber bottom end. Electrodes heated by the laser radiation cause the gas to be ionized, forming a plasma-arc in the constricting nozzle. The laser beam passing through the nozzle comes to a focus and interacts with the plasma-arc formed between the electrodes and a workpiece. The resulting interaction between the plasma-arc and the laser beam forms a plasma-laser discharge which acts to additionally constrict the laser beam and plasma-arc, causing an increase in the energy density of the welding spot formed on the workpiece.
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