Manufacturing method of small-bending-radius ultrathin-wall pipe

Abstract

The invention discloses a manufacturing method of a small-bending-radius ultrathin-wall pipe. The method includes the steps of: customizing a mold according to the boundary dimension of a to-be-manufactured pipe; cutting a straight pipe of which the outer diameter is smaller than that of the to-be-manufactured pipe to form a pipe blank, placing the pipe blank in a static die cavity of the mold, and fixing the two ends of the pipe blank; before bending, sealing one end of the pipe blank, and filling the pipe blank with liquid from the other end to reach a preset pressure; in a process from the beginning of a bending process to a mold assembling process, gradually increasing the liquid filling pressure from the preset pressure to a forming pressure; after mold assembly, increasing the liquid filling pressure in the pipe blank to an expansion pressure and maintaining the expansion pressure for a set time; and taking out the manufactured pipe. According to the manufacturing method, by virtue of the matching relation between a mold assembling force loading route and an internal pressure loading route, technological parameters such as different axial thrust routes, reference loading rates, waveforms and the like in a loading process are optimized, and therefore green, accurate and intelligent manufacturing of an ultrathin-wall complex pipe, which develops from nothing, is achieved.

Description

technical field [0001] The invention relates to the technical field of manufacturing ultra-thin-walled pipe fittings, in particular to a method for manufacturing ultra-thin-walled pipe fittings with a small bending radius. Background technique [0002] With the rise of a large number of high-tech industries represented by aviation and aerospace, the rapid development of advanced manufacturing technology has been promoted, especially the progress of pipe bending technology is the most obvious. In recent years, pipe bending technology has not only been widely used in pipeline equipment in chemical industry, petroleum, hydropower and other departments, but also has been widely used in aerospace, nuclear power industry, automobile industry, shipbuilding and other fields, playing an increasingly important role. effect. [0003] Using a hollow member similar to an elbow can not only reduce weight, but also maximize the strength and rigidity of the material. The pipe bending part...

AI Technical Summary

Problems solved by technology

[0004] For pipes with thin wall thickness (D / t≥20), especially ultra-thin wall pipes with a ratio of diameter to wall thickness greater than 100, bending will cause a large amount of deformation of the tube blank, and then the inner ring of the bending part Defects such as wrinkles will appear, and defects such as cracks will appear on the outer ring of the bent part. Various common defects are very easy to appear, resulting in a high product rejection rate

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