Welding gun for backing welding and backing welding method

Abstract

The invention relates to a welding gun for backing welding and a backing welding method. The welding gun is of an n-shaped structure, wherein a welding wire is arranged at one end of the welding gun; a gasket is arranged below the welding wire; a tungsten electrode or a laser fiber can also be arranged at one end of the welding gun; and the width of the welding gun is smaller than an assembly gap at the root of a welding groove, so that backing welding can be carried out on the back side of the welding groove through the gap in a penetrating manner. The whole welding seam of a pipeline is divided into a long section and a short section, the n-shaped welding gun penetrates through the assembly gap at the bottom of the welding groove to carry out backing welding on the back side of the welding groove of the long section, after backing welding of the long section is completed, the n-shaped welding gun is withdrawn from the short section, backing welding is conducted on the front side of the welding groove of the short section, and finally, welding of the whole backing welding seam is completed. According to the welding gun, the welding seam quality and the working efficiency of backing welding of the pipeline can be remarkably improved, and the cost of polishing treatment or purchasing inner hole welding, robot polishing and the like is reduced.

Description

technical field [0001] The invention belongs to the technical field of welding, and in particular relates to a back welding torch and a back welding method. Background technique [0002] In the welding production of equipment such as containers and pipes, single-sided welding and double-sided forming bottom welding are often encountered. Compared with the front weld, the appearance of the back of the bottom welding seam usually has uneven width and narrow shape, uneven height, and rough surface. The welds in the overhead welding position are prone to relatively low quality problems such as sags. For some welds with high quality requirements, it is often necessary to grind the back of the bottom welding seam, or use a special inner hole welding and grinding robot, resulting in work efficiency. Reduction and cost increase; for some important welding structures whose backside is not accessible, the poor formation of some weld backsides can easily lead to misjudgment of non-dest...

AI Technical Summary

Problems solved by technology

[0002] In the welding production of equipment such as containers and pipes, single-sided welding and double-sided forming bottom welding are often encountered. Compared with the front weld, the appearance of the back of the bottom welding seam usually has uneven width and narrow shape, uneven height, and rough surface. The welds in the overhead welding position are prone to relatively low quality problems such as sags. For some welds with high quality requirements, it is often necessary to grind the back of the bottom welding seam, or use a special inner hole welding and grinding robot, resulting in work efficiency. Reduction and cost increase; for some important welded structures that are not accessible on the back, some poorly formed welds on the back may easily lead to misjudgment of non-destructive testing false signals or stress concentration, which will become the source of defects and cause safety hazards during equipment operation

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