Forming method of large bending angle and small bending radius for thick-walled and large-diameter pipes

Abstract

The invention discloses a method for forming a thick-wall large-diameter pipeline with a large bending angle and a small bending radius. The method for forming the thick-wall large-diameter pipeline with the large bending angle and the small bending radius comprises two aspects, namely design of a pipe blank and design of a mould, wherein the pipe blank is a straight pipe, a step is formed in the outer diametric plane and used for mounting and clamping; the mould is divided into a cross beam part, a connecting rod part, a bending die part and a core rod part; the connecting rod part comprises a left connecting rod and a right connecting rod, the bending die part comprises a left bending die and a right bending die, the core rod part comprises a left core rod and a right core rod, the left connecting rod is connected between the cross beam and the left bending die, the right connecting rod is connected between the cross beam and the right bending die, and the lower ends of the left bending die and the right bending die are jointly pivoted and rotate together by virtue of one supporting pin shaft; and the pipe blank is placed in pipe penetrating cavities of the left bending die and the right bending die, and the left core rod and the right core rod respectively penetrate through the pipe blank from the left end and the right end. The method for forming the thick-wall large-diameter pipeline with the large bending angle and the small bending radius has the advantages that a simple mould is adopted for converting a provided pressure into a bending forming force of an elbow and the related technology is applicable to a large-angle bent pipeline with a thick wall, a large diameter and a small bending diameter ratio.

Description

technical field [0001] The invention relates to a pipe forming technology, in particular to a bending method of the invention applied to a large-diameter, thick-walled pipe with a large bending angle and a small bending radius, and belongs to the technical field of material processing. Background technique [0002] High-strength, thick-walled, large-diameter steel pipes are important components of industrial equipment, especially in petrochemical and nuclear power fields. Existing pipe bending processes mainly include: press bending, push bending, winding, etc., all of which require special molds or large-scale professional equipment to realize clamping and provide bending forming force. However, the deformation of large-scale pipes is complicated during the bending process, and defects such as angle springback, wall thickness thinning, and ellipticity exceeding the standard are prone to occur, which leads to large investment in pipe bending equipment, long follow-up debuggi...

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