STRETCH-REDUCING ROLLING MILL OPERATION METHOD AND STRETCH-REDUCING ROLLING MILL Russian patent published in 2007 - IPC B21B17/14 B21B37/78 

FIELD: tube production, namely operation method of stretch-reducing mill for rolling finite-length tubes.

SUBSTANCE: rolling mill includes at least two rolling stands arranged one after another along tube feed direction. Each rolling stand includes at least two mutually engaged rolls. Each roll rolls tube along predetermined peripheral zone of tube. Rolls of two different stands are driven by means at least of two drive units for enhancing quality of successive processes. Method comprises steps of determining time moment when rear end (along feed direction) of tube leaves last outlet rolling stand; setting time interval of predetermined duration including time moment when rear end of tube leaves outlet rolling stand; controlling drive unit of outlet rolling stand in such a way that to lower at said time interval revolution number of rolls of outlet rolling stand and to provide tube discharging at stable speed. Invention provides uniform motion of tube for achieving desired accuracy of process.

EFFECT: elimination of acceleration of tube at outlet of last rolling stand.

11 cl, 5 dwg