METHOD FOR MAKING PARTS SUCH AS SLEEVES HAVING THROUGH CAVITY AND OUTER SURFACE WITH AXIALLY VARIABLE CROSS SECTION Russian patent published in 2007 - IPC B21K21/08 

FIELD: plastic working of metals, possibly manufacture of sleeve type parts.

SUBSTANCE: method comprises steps of forming semi-finished product at deforming initial blank and calibrating it along outer lateral surface; pressing out cone cavity in semi-finished product by means of punch while providing displacement of excess metal occurred due to volume error of initial blank to end of semi-finished product; during one technological transition performing intermediate deforming of semi-finished product and finally forming part. In order to realize it, semi-finished product is placed in die of die set in such a way that its cone cavity is turned downwards and lower end of semi-finished product is placed with gap relative to bottom of die. With use of deforming punch cavity is pierced in semi-finished product in direction opposite to narrowing direction of cone cavity. Gap between lower end of semi-finished product and bottom of die is filled with material of semi-finished product and cone cavity is opened for forming metal scrap in front of deforming punch. Simultaneously metal scrap is removed and part cavity is calibrated.

EFFECT: lowered energy consumption of process.

10 cl, 11 dwg, 1 ex