Research On Upsetting-rolling-hydroforming Process Of The Parallel Double Branch Tube

In the past,welding and flanging technology was mainly used for the forming of parallel double branch tubes,and the forming parts produced by welding and flanging technology had poor forming quality and short service life.For these shortcomings,the tube hydroforming technology should be carried out.Nowadays,tube hydroforming technology is widely used in modern manufacturing,and its formed parts have the advantages of good forming quality,stable product quality and high production efficiency;At the same time,the tube hydroforming technology produces less waste,which is in line with contemporary near net forming technology and green manufacturing concept.So many colleges and enterprises have conducted in depth research on the tube hydroforming technology.In this paper,based on the traditional tube hydroforming technology process,the Upsetting-Rolling-Hydroforming(URH)technology of parallel double-branch tubes is proposed.The Upsetting-Rolling-Hydroforming(URH)technology mainly use the variable diameter tube,and by the mandrel to roll the local thickening area of tube to improve the fluidity of materials,so that improving the forming performance of the tube.By independently designing the Upsetting-Rolling-Hydroforming(URH)forming device,realized the purpose of loading three loads of upsetting,rolling and hydroforming at the same time.Therefore a series of studies are carried out around the Upsetting-Rolling-Hydroforming(URH)technology of parallel double branch tube.(1)In exploring the Upsetting-Rolling-Hydroforming(URH)technology of parallel double branch tubes,The Upsetting-Rolling-Hydroforming(URH)forming devices were designed independently in this paper,and finally met the requirements required for the experiment.(2)In the process of finite element analysis,in order to obtain the real stress and strain of annealed copper,the engineering stress and strain of annealed copper are obtained by tensile test,and the true stress-strain of the annealed copper is drawn finally,which provides real and reliable data for the setting of material properties of finite element method.(3)In this paper,based on numerical simulation and experiment,starting from the tube branch height,wall thickness reduction rate and metal flowability aspect,comparative analysis the traditional hydroforming technology and the Upsetting-Rolling-Hydroforming(URH)technology for parallel double-tube forming performance influeNces,and analysis the tube free forming technology and the Upsetting-Rolling-Hydroforming(URH) technology for parallel double-tube forming performance influences.(4)Through the surface response method established the surface response model,analyzed the forming performance of parallel double branch tube among internal pressure loading rate,mandrel rolling angle and local thickness increment,Finally,prediction of tube forming results by surface response fitting formula.In this paper,the numerical simulation and experimental method are combined to explore the Upsetting-Rolling-Hydroforming(URH)technology on the forming perforrmance of the parallel double branch tube,and through the comparative analysis of comparative analysis free forming process of parallel double branch tubes,traditional hydroforming technology and the Upsetting-Rolling-Hydroforming(URH)technology for parallel double-tube forming performance influences.Finally,draw a general conclusion and provides the actual production provides some reference.