Research On System Of Thin-walled Tube Internal High-pressure Forming

In the fields of automobile industry and so on, weight reduction of structures is the goal that people have pursued for a long time in order to reduce the energy consumption. It is a trend in the development of advanced manufacturing technology too. Internal High-pressure Forming(IHF), as an advanced technology characterized by lightweight and integrity, which can be used to manufacture hollow structural components and variable cross-section parts, obtained more and more people's attention. At present, although a large number of domestic scholars study this technology, because of a late start and lack of experimental conditions, most studies are based on finite element analysis, which result in many research results could not be verified. Therefore, the development of IHF system and researches on forming process have become an important issue at present. And this will surelly bring great significance on the development of China's automobile industry and energy conservation.After consulting numerous related literatures and reference materials at home and abroad, the development and application and current trend of domestic and oversea of IHF is summarized in this paper. Later, according to the needs of experiment, a set of IHF dies is designed, which can be used to complete different experiment.Through uniaxial tensile test at room temperature, got the vaule of mechanical performance parameters of the tube and the laws that these performance parameters changes with the speed. Combined the laws and the IHF process and then through further analysis, serveal loading rules are put forward.Using the elastic-plastic mechanics theory, this paper has also carried on stress and strain analysis in the forming process. Thus got further understand of characteristics of deformation of the tube.On this basis, established the relationship between the various forming parameters. Defined the bulge coefficient of the solid of rotation and the rectangular cross-section component respectively. This bulge coefficient can be maked as an design criterian for IHF process. Through theoretical analysis, obtained the calculation formula used to estimate the internal high-pressure at the initial and the end of the IHF process.Finally, the requirements of hydraulic system design to IHF process are analyzed and the key questions involved in the IHF process are studyed. Eventually, established the design scheme of the forming hydraulic system and the electro-hydraulic control system.