Study on whole hydroforming method of long annular thin-walled lip
In order to solve the problem of difficult forming of long annular thin-walled lip with large drawing ratio,a secondary passive hydroforming process scheme was designed to form the pneumatic shape area first and then the inner inlet area.By means of finite element model analysis and die trial optimization,the whole forming of long annular thin-walled lip was realized,and the wall thickness variation law was mastered by simulation and optimization of liquid chamber load-ing curve,blank holder condition,back expansion,and blank shape,the pressure of liquid chamber produced beneficial friction between sheet metal and punch,which effectively restrained the thin-ning of punch fillet.Under the condition of blank holder with constant clearance,the thinning rate of the hanging area at the flange root position increased with the increase of the maximum cham-ber pressure.Compared with traditional drawing,passive hydroforming could easily transfer the maximum thinning area from the punch rounded area to the die rounded area.
large drawing ratiomulti-pass hydroforminglarge lip partsnumerical simulation
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万方数据
维普
