Small-interior diameter deep hole plasma spray welding gun

Abstract

The invention discloses a plasma spray welding gun for a deep hole with small inside diameter, which comprises a negative electrode and a positive electrode in a shell. The shell is provided with a nozzle, the shell is in a shape of a blind tube, the inner wall of the shell is provided with an insulating coating, the tube wall is provided with a nozzle mounting hole, the nozzle is arranged in themounting hole in the radial direction, and a body part of the nozzle is arranged in the space of the tube; the nozzle is a composite nozzle, and is provided with an ion gas jet passage, a powder feeding gas jet passage, and a protective gas jet passage; the geometrical shape of the positive electrode accords with the inner space of the blind tube, the positive electrode is filled in the blind tube, a longitudinal eccentric macro pore for arranging the negative electrode and two longitudinal pores of the ion gas passage and the powder feeding gas passage are arranged in the positive electrode,and the two pores are communicated with the ion gas jet passage and the powder feeding gas jet passage of the nozzle respectively; and the negative electrode consists of a cathode bar, a cathode baseand a cathode head, wherein the cathode bar is inserted in the eccentric macro pore of the positive electrode; and the cathode base is connected with the cathode bar, the root end of the cathode headis fixed in the cathode base and connected with the cathode bar, and the head end of the cathode head extends into a central hole of the nozzle. The spray welding gun has the advantages of compact structure and small size, and can weld in the deep hole with more than phi 36 millimeters; and the diameter of a gun head can be made into 26 millimeters.

Description

technical field [0001] The invention relates to a plasma spray welding torch, in particular to a plasma spray welding torch used for welding in deep holes with small inner diameters. Background technique [0002] Industrial installations often have some small-diameter deep holes that require surface treatment. For example, the valve core parts in gas turbines have a series of sleeves with a diameter of φ48-70mm. It is required to spray weld a layer of Stellite alloy on the inner wall of the hole. Welding process welding. However, in the existing plasma spray welding torches, the cathode and anode electrodes in the torch head are arranged separately, and the space occupied is relatively large, so the diameter of the torch head is also relatively large, at least above φ80mm, and can only be inserted into the torch with a diameter greater than φ100mm. It is impossible to process the above-mentioned small-diameter deep-hole workpieces by welding in the holes. Contents of the ...

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Problems solved by technology

However, in the existing plasma spray welding torches, the cathode and anode electrodes in the torch head are arranged separately, and the space occupied is relatively large, so the diameter of the torch head is also relatively large, at least above φ80mm, and can only be inserted into the torch with a diameter greater than φ100mm. Welding in the hole, it is impossible to process the above-mentioned small-diameter deep-hole workpiece

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