METHOD FOR MAKING HOLLOW ARTICLES Russian patent published in 2001 - IPC

FIELD: plastic working of sheet materials, namely manufacture of hollow products with bottom and constant outer diameter. SUBSTANCE: method for making hollow articles having high strength in zone of transition of walls to bottom without increased thickness of bottom comprises steps of drawing metallic sheet; necking drawn sheet and shaping bottom. Punch used for drawing with necking has terminal portion narrowed from main part of punch towards its end portion. Size of terminal portion of punch is selected according to conditions providing (after operation of bottom shaping) thickness value of wall of article in zone of wall-to-bottom transition no less than thickness value of its lateral walls. EFFECT: possibility for making hollow products with high strength of wall-to-bottom transition zone. 3 cl, 3 dwg