METHOD OF FORMING BY RESILIENT MEDIUM Russian patent published in 2014 - IPC B21D22/10 

FIELD: process engineering.

SUBSTANCE: invention relates to metal forming, particularly, to cold forming of thin metal sheets by resilient medium by performing deep drawing in several passes. At first pass, stack of several thin-sheet blanks is subjected to deep drawing at male die, its profile making a mirror reflection of the part required profile. At second step, stack of billets is turned over to carry out the next passes at the same stack at male die with profile the mirror reflection of the part required profile. Forming pressure at every pass increases while final pass is performed at every single stack of billets at rigid male die with profile the mirror reflection of the part required profile. Note here that after every pass at all steps the blanks are subjected to thermal treatment.

EFFECT: higher quality and efficiency.