Method for forming complex double-curvature skin part

Abstract

The invention discloses a method for forming a complex double-curvature skin part. The method comprises the following steps: firstly forming a double-curvature part in a range of 1 / 5-1 / 3 of the bottom of the part through a pre-forming die by adopting an active liquid-filling forming mode, and forming a side wall of the double-curvature part and local characteristics on the side wall through a final forming die by adopting a passive liquid-filling forming mode. According to the method, in the first step, the active liquid-filling forming mode is adopted, the stress state of the skin part in the skin drawing forming process is changed, and the problems that in the drawing process, stress is uneven, and the top is broken and a suspended area wrinkles due to the fact that the size of the cross section is greatly changed are solved; and in the second step,the active liquid-filling forming mode is adopted, soft draw beads are formed in the forming process so that wrinkling can be restrained, and meanwhile local complex characteristics such as pits and protrusions of the side wall of the double-curvature skin part can be formed.

Description

technical field [0001] The invention relates to the field of plastic forming of plates, and is especially suitable for the forming method of complex hyperbolic skin parts. Background technique [0002] The aircraft skin is a part that surrounds the aircraft skeleton structure and is fixed on the skeleton by bonding or riveting to form the aerodynamic shape of the aircraft, and plays the role of bearing and transmitting the starting load. Aluminum alloy skin parts are widely used in the field of aviation manufacturing. According to the shape of parts, they can be divided into two types: single-curvature skin parts and double-curvature skin parts. Traditional large-scale skin parts are usually , protrusions, and double-curvature skin parts with large changes in the cross-sectional size of the parts, especially parts with curvature changes in different directions at the ends of the skin parts, the drawing process will cause the pits, protrusions, etc. to be different from the s...

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Problems solved by technology

[0003] In order to overcome defects such as non-sticking, wrinkling, and cracking of complex hyperbolic skin parts during the drawing process, the present invention provides a forming method and mold structure for complex hyperbolic skin parts to solve the problem of large complex hyperbolic Forming problems of skinned parts

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