Method for segmented stretch forming molding of 2000-series aluminum alloy skin

Abstract

The invention relates to a method for molding aeronautic sheet metal parts, belongs to the technical field of aeronautic manufacturing and provides a method for segmented stretch forming molding of 2000-series aluminum alloy skin. The method for segmented stretch forming molding of the 2000-series aluminum alloy skin comprises the following steps that firstly, according to the radian characteristics of the skin stretch forming die profile, the skin stretch forming die profile is divided into multiple areas of a first area, a second area and the like; secondly, two ends of skin are clamped by jaws of a stretch forming machine; and thirdly, stretch forming molding is conducted on the first area, the second area and the like of the skin in sequence according to working procedures so that profiles, located in the first area, the second area and the like, of the skin and a skin stretch forming die are fitted completely, and namely, stretch forming molding of the skin is completed. The method for segmented stretch forming molding of the 2000-series aluminum alloy skin has the following advantages that firstly, the stretch forming molding uniformity is improved, and defects such as slip lines and cracks are prevented from being generated in partial areas of the skin; and secondly, the shape radian conformity after skin stretch forming is improved so that project drawing requirements are met by the shape radian conformity, and then the skin quality is improved so that more outstanding aircraft pneumatic shape can be achieved.

Description

technical field [0001] The invention relates to a forming method for aviation sheet metal parts, which belongs to the technical field of aviation manufacturing. Background technique [0002] Aircraft skin stretch forming technology is a forming technology for aircraft sheet metal parts. Compared with other sheet metal forming technologies, skin stretch forming technology has the technical advantage of small part springback, and is especially suitable for large multi-dimensional curvature masks. It is widely used in the aerospace industry for the molding of leather parts. However, limited by the forming performance of the skin material, in order to ensure that the skin material does not break and minimize the generation of slip lines on the outer surface when stretching large-curvature skin parts, there is often a problem after the skin is formed. The curvature of the shape does not meet the requirements of the engineering drawings, which affects the acceptance of the skin, ...

AI Technical Summary

Problems solved by technology

However, limited by the forming performance of the skin material, in order to ensure that the skin material does not break and minimize the generation of slip lines on the outer surface when stretching large-curvature skin parts, there is often a problem after the skin is formed. The curvature of the shape does not meet the requirements of the engineering drawings, which affects the acceptance of the skin, and the assembly stress caused by the poor conformity of the shape curvature seriously affects the flight safety of the aircraft

[0003] The traditional single-process skin stretching molding adopts the forming method of first contacting all the skin materials with the surface of the skin stretching mold and then stretching the radian of the skin shape at one time. This forming method cannot be based on the different parts of the skin. The radian of the shape requires independent adjustment of the process parameters of the deformation of different parts during stretch forming, and the stretch forming method of a single process requires that the skin needs to be plastically deformed under the condition of overcoming the friction force in the entire skin surface area, which is serious It affects the fluidity of the skin material during stretch forming, which will eventually lead to insufficient plastic deformation of the skin material when it reaches the maximum tensile deformation, resulting in unqualified skin radian

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