Integral forming method for large-diameter storage tank bottom with flanged-hole structure

Abstract

The invention provides an integral forming method for the large-diameter storage tank bottom with a flanged-hole structure. The integral forming method comprises the following steps of 1) pressing forming, 2) spinning forming, 3) hole-flanging forming, 4) heat treatment, and 5) shape correction. According to the integral forming method, a circular plate blank is gradually pressed into a shallow dish-shaped workpiece by using a pressing die on a pressing machine, and a through hole is formed in the center position of the shallow dish-shaped workpiece by adopting a turning or plasma cutting mode; the shallow dish-shaped workpiece obtained in the step 1) is fixed on a spinning machine, and the side edge of the shallow dish-shaped workpiece is subjected to spinning forming through spinning rotating wheels until the molded surface requirement is met; and the shallow dish-shaped workpiece obtained in the step 2) is fixed on a hydraulic machine, and hole-flanging forming of the whole tank bottom of a storage tank is achieved through a hole-flanging die on the hydraulic machine. The integral forming method has the advantages that flexible integral forming of the tank bottom of the storagetank can be realized, equipment and process equipment requirements are low, the production cycle of the tank bottom is greatly shortened, the labor intensity of the tank bottom is greatly reduced, andthe manufacturing precision and reliability of the tank bottom are effectively improved.

Description

technical field [0001] The invention relates to the technical field of launch vehicle tanks, in particular to a method for integrally forming the bottom of a large-diameter tank with a hole-turning structure. Background technique [0002] The bottom of the carrier rocket tank is a large-diameter thin-walled ellipsoid shell, and its material is generally made of heat-treatable aluminum alloy plate, such as the Chinese patent CN109798203B, which discloses a tank bottom structure and a connection structure between the tank bottom and the engine , wherein the tank bottom structure is connected together by tailor welding. [0003] It can be seen that most of the bottoms of the launch vehicle tanks currently in service in my country are processed by the process of tailor-welding of melon petals and top covers. figure 1 shown. The following problems exist in the process of tailor welding forming: 1) the number of welds is large, which affects the overall strength and reliability ...

AI Technical Summary

Problems solved by technology

The following problems exist in the process of tailor welding forming: 1) the number of welds is large, which affects the overall strength and reliability of the box bottom; 2) deformation is easy to occur during tailor welding, which affects the final shape accuracy of the box bottom; The thickening area is set, which limits the weight loss of the structure; 4) A large number of calibration and repair work are required before the tailor welding of the melon petals and the top cover, which is labor-intensive and the manufacturing cycle of the tailor-welded box bottom is long

At present, the overall box bottom of foreign launch vehicles adopts liquid-filled deep drawing and "one-step" spinning process schemes. The former has high requirements for equipment, and the development of equipment is difficult, and the forming process is prone to instability and wrinkling; the latter belongs to local plastic forming. For liquid-filled deep drawing, the investment in equipment and tooling is less, but the flexible processing of head parts cannot be realized

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