Tube drawing forming method and forming mould

Abstract

The invention discloses a tube drawing forming method and forming mould. In the forming method, extrusion-bulging deformation is performed on a tube by using a drawing torsion variable-section core to realize combination of various deformation modes in a primary forming process. The tube wall of the formed tube is subjected to the extrusion-bulging of the core and is in a strong three-way compressive stress state due to the limitation of a polyurethane filling layer; at a deformation stage of circular-elliptical-circular and elliptical torsion change, the tube enters a torsion shearing deformation zone of a metal transition region; under the action of shearing stress, the internal organization of the material is subjected to rotation and shear strain to cause the orientation of a materialorganization structure, namely a new texture is formed, thereby improving deformation texture under the equivalent deformation degree. The drawing variable-section core extrusion-bulging tube deformsto achieve larger deformation degree compared with that of the conventional forming process, so that strain distribution and stress distribution in the tube are improved, the casting organization remained in the broken tube is facilitated, the form and the distribution of inclusion are changed, and the defects of the internal organization of the tube are overcome.

Description

Technical field [0001] The invention relates to the forming field of metal pipes such as aluminum, copper, steel, etc., in particular to a method and a forming die for drawing and forming pipes. Background technique [0002] In the fields of aviation, aerospace, automobile and machinery equipment, all involve the use of pipe fittings and pipe sleeves. Take an airplane as an example. The pipeline system is the lifeline of the airplane. Its performance directly affects the overall performance of the airplane. If the engine is compared to the heart of the airplane, the pipeline is like the blood vessel of the airplane. Therefore, improving the technical level of the pipeline system is very important for improving the performance of the aircraft. [0003] At present, the metal pipes used in piping systems on the market mostly adopt traditional forming methods, and most of them are seamless pipes (Baogang Technology, 2002, 2:21). The characteristic of this kind of pipe is that the thi...

AI Technical Summary

Problems solved by technology

A variable-channel extrusion die proposed by Northwestern Polytechnical University in a patent application with a publication number of CN201371172, and a tire mold for long-axis forging blanks proposed in a patent application with a publication number of CN201711480U, and the publication number A device for preparing variable-channel ultra-fine-grained copper-aluminum wires proposed in the patent application of CN201862645U is formed by a variable-section torsional mold cavity that changes from a circular cross-section to an elliptical cross-section, and then from an elliptical cross-section to a circular cross-section. The prefabricated workpiece has the characteristics of simple structure, small load, low cost and high efficiency. It can be widely used in the production of bars and wires of steel and non-ferrous metals, as well as the production of large shaft parts, high-speed steel and powder metallurgy and other hard-to-deform materials. billet, but no one has used this simple subsequent processing method for pipes

[0006] The above-mentioned traditional pipe-making process is difficult to meet the needs of the growing aviation industry. Due to insufficient strength and the influence of deformation texture, cracking will occur during use, which will affect the safety and reliability of aircraft pipelines in severe cases.

Images