A device for rounding the inside of a thin-walled metal pipe

Abstract

The invention discloses a rounding device for the inner side of a thin-walled metal pipe, which comprises a rotatable camshaft body and a plurality of ejector rod assemblies extending and contracting along the camshaft body; The camshaft body includes a rotating shaft arranged in the middle, and a "windmill" cam with a plurality of fan blades evenly distributed in the circumferential direction is respectively arranged on both sides of the rotating shaft, and the two cams on both sides are dislocated at a certain angle, so Each ejector rod assembly is covered with a spring and the shell is provided with a return spring slot, the return spring slot makes the spring always in a compressed state and then drives one end of each ejector rod assembly to always be against the corresponding fan blade , the outer side of the shell is provided with a hydraulic cylinder that provides power for the rotation of the camshaft body. The present invention is ingenious in design, easy to use, and high in accuracy, and can be applied to anti-deformation of the inner side during welding of metal pipes in areas that are not accessible on the inner side of various paths. The support ensures the inner diameter and roundness of the pipeline.

Description

technical field [0001] The invention relates to the field of metal thin-walled pipeline welding, in particular to an inner rounding device for thin-walled metal pipelines, which is used for controlling the welding deformation outside the unreachable inner side of the pressure-bearing pipeline of petrochemical containers and nuclear power equipment. Background technique [0002] Metal pipes are widely used in petrochemical and nuclear power manufacturing fields as fluid-carrying shells. The heat exchange pipes of nuclear island pressure vessel equipment in nuclear power plants operate in the environment of high temperature, high pressure and high-speed flow of internal media, and their roundness and diameter have an important impact on the pressure life and flow rate. However, in the process of pipe connection, the butt welding of pipes and the welding of pipe outer wall parts will cause problems such as thermal shrinkage deformation, resulting in pipe ellipse and smaller dia...

AI Technical Summary

Problems solved by technology

However, in the process of pipe connection, pipe butt welding and pipe outer wall parts welding will produce heat shrinkage deformation, which will lead to problems such as pipe ellipse and diameter reduction, and affect the positioning size of pipe wall welding parts

Usually, for the butt welding of pipes with larger diameters that can enter people, the welding deformation can be balanced by alternating welding on both sides of the pipe inside and outside, and before welding, personnel can use tools to support the inside of the pipe to control the roundness of the pipe; When welding small pipes, its own rigidity can prevent welding shrinkage and deformation; when welding thin-walled pipes with an inner diameter of about 100-400mm, the diameter of the pipe cannot meet the requirements for personnel to enter, and after butt jointing, only the outer side can be welded, and the rigidity of the pipe is low. Its own strength cannot resist the shrinkage and deformation caused by the outer welding, and the weld seam will collapse unevenly inward during the welding high-temperature cooling process, resulting in elliptical roundness and smaller diameter

For the above problems, there is no good way to control the welding deformation of thin-walled pipes in the prior art

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