METHOD OF PRODUCING HOLLOW ARTICLES Russian patent published in 2011 - IPC B21D51/10 B21D22/28 B21D28/16 

FIELD: process engineering.

SUBSTANCE: invention relates to sheet metal forming and may be used for producing hollow articles with constant OD and height. Sheet blanks is produced from sheet material by extruding and blanking by appropriate tool. Sad tool has face surface between its ID and OD representing a cone with apex angle of 120°-160°. Proposed blank is subjected to drawing, drawing with wall thickening and article bottom forming, all said jobs being performed sequentially. Drawing and drawing with wall thickening are performed using cupping punch arranged aligned with blanking punch. Cupping punch features taper of 2-4° at height equal to that of article cavity. In compliance with another version, cupping punch features taper of 10-20° at the height equal to 20-30% of article cavity height.

EFFECT: precise article height and edge shape.

3 cl, 5 dwg