Double-curved-surface skin opening frame forming method

Abstract

The invention relates to a double-curved-surface sawtooth skin opening frame forming method, and belongs to the technical field of aeronautical manufacturing metal plate forming. The double-curved-surface skin opening frame forming method comprises the following steps that (1) the two ends of the long edge of a skin plate are put in a jaw of drawing forming equipment, and the skin plate is kept tangent to a forming mold; (2) a hydraulic actuator cylinder of the jaw drives the jaw to move, the skin plate is in contact with a hollow area and a molded surface of the surface of the forming mold and is drawn to generate an opening frame R angle, and a semi-finished product of a to-be-formed part is obtained; (3) a square hole is formed in the drawn semi-finished product of the part to be formedon the forming mold, and meanwhile, edge bending operation is carried out on the square hole by an edge bending hole cover plate; and (4) the outer surface of the semi-finished product of the part tobe formed is covered with a glass fiber reinforced plastic scribing template for scribing, excess materials are removed along a line, and correcting is carried out on the trimmed semi-finished product on a mold until a product is completely formed. The double-curved-surface sawtooth skin opening frame forming method has the following advantages that 1, the forming defect of a typical fuselage hyperboloid skin opening frame structural part can be overcome; and 2, the production efficiency is obviously improved.

Description

technical field [0001] The invention relates to a method for forming a hyperboloid sawtooth skin mouth frame, which belongs to the technical field of aviation manufacturing sheet metal forming. Background technique [0002] With the development of overall assembly of aircraft, the size of the skin mouth frame increases accordingly. A certain type of fuselage skin mouth frame is used as a common type of structural part on the fuselage parts. Such structural parts are generally large in size and thick in material; they have complex shapes and structures, large longitudinal curvature, irregular curved surfaces, and the parts usually have part bending holes 1-1 and sunken areas 1-2. Such as figure 1 It is a schematic diagram of a typical part structure of a fuselage skin frame. [0003] Such structural parts are usually used as the support frame of the outer skin of the fuselage, and the profile is closely attached to the outer skin. At the same time, the parts are coordinate...

AI Technical Summary

Problems solved by technology

[0004] This kind of mouth frame structure involves theoretical shape and high precision requirements of the shape. There are the following difficulties in forming: 1. The single manual forming needs to be carried out separately on the shape surface, the curved edge frame and the sag, and the forming difficulty and strength are high, and The cycle is long; 2. Use the drawing die to form the surface of the part. The flanged mouth frame and the sinking are located in the surface area. Usually, the cover plate needs to be prepared after the surface is drawn to perform operations such as manual bending and trimming, and each needs to be customized. Set of drawing molds and hand molds, the cost of tooling manufacturing is relatively high

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