METHOD FOR MAKING TUBULAR BLANKS WITH BOTTOM, NAMELY TIE RODS OF WINDSHIELD WIPERS Russian patent published in 2003 - IPC

FIELD: machine engineering, namely manufacture of tubular blanks with bottom of sheet blanks. SUBSTANCE: method comprises steps of blanking round blank in first die set; subjecting it to combination drawing and subsequent stretching in second die set; drawing without necking in third die set and then stretching; finally swaging blank in fifth die set by means of punch with cylindrical protrusion and lower die with inlet and sizing portions. Diameter of cylindrical protrusion of punch is equal to that of sizing portion of lower die; height of said protrusion is equal to that of inlet and sizing portions of lower die. EFFECT: enhanced quality of blanks, improved operational conditions of die tool. 2 dwg, 1 ex