Reverse molding necked-in transferring drill rocker end upsetting method

Abstract

The invention relates to a method for thickening the tube end of a drill stem through reverse molding and diameter reducing and transferring. The method adopts a multi-pass inner and outer thickening process. When one certain thickening pass begins to adopt inner and outer thickening, the length of an outer thickening transition section is 130 mm; the inner thickening occurs in initial quantity; a change point of an inner thickening transition section is consistent with an outer thickening change point of a first pass; after two thickening passes, firstly, the thickening part of the tube end is subjected to flattening; secondly, a diameter reducing mould is used for carrying out diameter reducing on the flattened tube end; after the diameter reducing, a control ring of an inner thickeningconical surface is formed in the smallest diameter part of the inner thickening transition conical surface; and when the subsequent thickening pass is used for thickening for upset forging, the control ring of the inner thickening conical surface and the outer wall of a punch are fully contacted to ensure the molded inner transition conical surface is not influenced by upset forging and produces deformation. The method changes the inner thickening conical surface regular, stable, flat and smooth under the strict control condition, evenly distributes the stress of the thickening transition part of the tube end of the drill stem, makes a stress change gradient more smooth, and substantially reduces piercing probability caused by stress concentration in the use of the drill stem.

Description

Technical field [0001] The present invention involves oil and natural gas diamonds using drilling rods, oil pipes, and tube tubes, especially the deepening method of reverse molding diameter transfer rod pipe end. Background technique [0002] The drill rod is the main component of the oil and gas drilling tool. The drill rod consists of the tube and the connector with a thread.The connection method of the thread joint and the tube is friction welding.In order to improve the carrying capacity of the welding diameter, the two ends of the tube should be thickened before welding.Use performance.At present, my country's drilling rod production is mainly based on the US API SPEC 5D standard. This standard requires the requirements for internal and external thickened drill rods: thickened pipe end must have internal thickened transition segments (MIU) and internal thickness segments (LiU) (see the figure in the figure) (see the figure in the figure. 1), the length of the transition sec...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a method for thickening the pipe end of the drill pipe with reverse forming reducing diameter transfer. The shrinkage fluctuation causes the technical problem of the mechanism of stacking and pits in the inner thickening transition section. It can make the inner thickening cone surface become regular, stable, smooth and smooth under strict control conditions, and the disappearance of the inner thickening cone surface is round. The radius of curvature of the arc (R) increases, the minimum length of the inner thickening transition section (Miu) increases to 130mm, the stress distribution of the thickened transition part of the drill pipe end is more uniform, the stress gradient is more gentle, and the stress of the drill pipe during use The probability of concentration causing piercing is greatly reduced

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