High-pressure forming method in pipe

Abstract

The invention discloses a high-pressure forming method a in pipe. The method comprises the steps that the pipe is firstly placed in a die cavity of a pipe element to be formed of a lower mold, a sealing punch is driven by a side push cylinder to enter two ends of the pipe, and the end sealing of the pipe is completed; an upper mold is driven by a slide block of a mold assembling press machine to descend to a position with a certain height from the lower mold, high-pressure liquid is introduced into the pipe, and in addition, the inner pressure of the pipe is matched with the upper mold stroke until the mold assembling is completed; the pressure maintaining is carried out or the pressure is properly increased for shaping the pipe. The method has the advantages that the mold assembling force is utilized for promoting straight edge section materials to move towards the round corner position of a forming mold, so the pressure required for forming the round corner position is obviously reduced, the thick-wall and high-intensity steel pipe element forming requirements are met, and meanwhile, the requirements on the maximum tonnage of the mold assembling press machine, the pressure bearing capability required by the mold, the reliability of a sealing structure and the pressure of a pressure booster are reduced, so the production cost is reduced, in addition, the uniform wall thickness of the pipe is favorably realized, and the excessive thinning and cracking of the thick wall in the forming process is avoided.

Description

technical field [0001] The invention belongs to the technical field of plastic forming of tubular parts, and in particular relates to a method for high-pressure forming in pipes. Background technique [0002] Tube hydroforming (also known as internal high pressure forming) is an advanced manufacturing technology for manufacturing hollow integral components. Compared with the traditional hollow component manufacturing process of stamping first and then welding, it has obvious advantages. It can reduce costs and improve the strength of parts and stiffness. According to the statistical analysis of the applied hydroforming parts by German Schuler Company, the production cost of hydroforming parts is 15% to 20% lower than that of stamping parts on average, and the mold cost is reduced by 20% to 30%. Therefore, it has been widely used in the fields of automobile, aviation and aerospace manufacturing. Especially in the production of automobiles, such as the sub-frame of the car a...

AI Technical Summary

Problems solved by technology

[0003] In the existing internal high pressure forming process, after the upper mold and the lower mold are completely closed, the sealing punch is used to seal the pipe end and then the internal pressure is applied to form. If the internal fillet of the part is very small, or the wall thickness of the part is very large, the part will be formed The required pressure will increase significantly. With the expansion of the application range of internal high pressure forming parts, the increase of pipe wall thickness and the application of high-strength pipes, the forming pressure will be further increased, so that the maximum tonnage of the clamping press, The pressure bearing capacity required by the mold, the reliability of the sealing structure, and the pressure of the supercharger put forward higher requirements, which will increase the production cost, and some parts will not be able to be produced under the existing equipment capacity.

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