SHAPING OF CONVEXO-CONVEX SHELL THIN-SHEET PARTS BY STRETCH-WRAP FORMING Russian patent published in 2016 - IPC B21D11/20 

FIELD: process engineering.

SUBSTANCE: invention relates to metal forming and can be used for production of shells for aircraft at stretch-wrap NC machines. Claimed process includes two stretch-wrap steps that follow. Rectangular blank is stretched-wrapped after its wrapping to the complete coverage of stretch-wrap male die angle equal to 90 degrees. Then, the shell part is stretched-wrapped at its new position from the unbending angle by stretching of formed blank side sections free from the clamps. Between said steps shell surface is unloaded and unbent by the surface development through a definite angle to get the surface isometric shape relative to stretch-wrap surface shape. After second step, the shell part is subjected to reverse wrapping through said complete angle of 90 degrees owing to initial isometric shape of appropriate male die surface.

EFFECT: reduced irregular stretching in both directions of the sheet.

14 dwg