A Repair Welding Process for Threaded Blind Hole Depth Out of Tolerance

Abstract

The invention relates to a repair welding process used after thread blind hole depth difference exceeding, and belongs to the technical field of transformer production. According to the technical scheme, as for through-top, protruding and too-thin thread blind holes, a pointed cone (4) is used for knocking through-top, protruding and too-thin parts at the back face of workpieces, the knocking force enables the parts to form conical grooves, and conical tips of the conical grooves cannot exceed conical ends of bottom holes; and the thread blind holes are filled with copper bars or asbestos cords, repair welding is carried out at the conical grooves, the repair welding thickness is slightly larger than that of the surfaces of the back faces of the workpieces, and then rubdown is carried out. The repair welding process has the beneficial effects that repairing after the bottom holes of the thread blind holes of the parts are too deep is achieved, the parts can be rapidly desterilized while the original reliable sealing thickness of the parts is recovered, the material cost and the maintaining cost for flange replacement are reduced, and the repair welding process is particularly suitable for the transformer production process.

Description

technical field [0001] The invention relates to a repair welding process after the depth of a threaded blind hole is out of tolerance, and belongs to the technical field of transformer production. Background technique [0002] Many workpieces such as flanges and bottom plates with threaded blind holes are used in the manufacture of transformer oil tanks. For the form of threaded blind holes, see the attached figure 1 . In the process of processing, sometimes there is a deviation in the control of the depth of the bottom hole. If the bottom hole is too deep, there will be quality problems such as too thin steel plate at the bottom of the bottom hole, bulging at the bottom of the bottom hole, and penetration at the bottom of the bottom hole. For details, see the attached figure 2 hint. If the bottom hole is too deep, the reliability of the oil tightness (or air tightness) at the bottom of the threaded blind hole will be reduced, or it will directly cause oil (gas) leakage. ...

AI Technical Summary

Problems solved by technology

If the bottom hole is too deep, the reliability of the oil tightness (or air tightness) at the bottom of the threaded blind hole will be reduced, or it will directly cause oil (gas) leakage. Therefore, the flange (or other parts) with the problem of too deep bottom hole cannot be use

If the bottom hole is too deep, the repair method in the prior art is to re-drill and process the threaded holes after repairing all the screw holes; (or bottom plate and other parts) gas cutting or gas explosion, after removing it, replace it with a new one, and re-weld. There will be a lot of welding and post-welding shaping work during repair, and there will be a risk of irreparable post-welding deformation, which is very labor-intensive and time-consuming

At present, in the production of transformers, there are a large number of parts such as threaded blind hole flanges and bottom plates, and such quality problems will occur during processing. The existing technical repair methods need to waste a lot of labor and material costs, and there will be irreparable post-weld defects. Deformation risk, unable to meet production requirements

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