METHOD FOR MAKING TUBES BY COLD PILGERING AND EQUIPMENT FOR PERFORMING THE SAME Russian patent published in 2003 - IPC

FIELD: manufacture of tubes of high-strength steels or special alloys in two rolling stands performing periodical mutually opposite reciprocation motion by means of crank mechanisms in rolling direction between narrowed-groove rolls rolling around article at changing direction through gear wheels driven by toothed racks. SUBSTANCE: method comprises steps of performing in first rolling stand main part of plastic deformation and in second rolling stand remained non-significant part of plastic deformation process; performing in both stands rolling at reduction by means of mandrel corresponding to roll grooved pass; providing reciprocation motion of both stands in accordance one with another in such a way that deformation zone of first stand does not coincide with deformation zone of second stand. Equipment for performing the method includes first rolling stand in the form of cogging stand whose rolls have only working grooves. Rolls of second stand have working grooves and ironing grooves. Rolls of both stands are mounted with possibility of engaging with respectively calibrated mandrels. Crank mechanisms having mutual angular shift for driving rolling stands include for each stand separate connecting rod with vertical rotation axes. EFFECT: enhanced efficiency of pilger mill. 13 cl, 2 dwg, 2 tbl