Device and method for handling mandrel rods in a tube rolling mill

A method of rolling seamless tubes (2′), comprising:

• inserting a tube blank (2) and a mandrel rod (3) into a rolling line (L), such that the mandrel rod (3) is located downstream of an inserter (11), the tube blank (2) is located downstream of the mandrel rod (3), and
• a first rolling stand (21) of a rolling mill (20) is located downstream of the tube blank (2),
• as a result of which the mandrel rod (3) is in an initial state;
• positioning a fixing unit (12a) of a retaining device (12) at a starting position (XA) that is located between two ends (3a, 3b) of the mandrel rod (3), wherein the fixing unit (12a) is released from the mandrel rod (3) in such a manner that the mandrel rod (3) is movable along the rolling line (L) relative to the fixing unit (12a);
• moving the inserter (11) in a rolling direction (R), as a result of which the inserter (11) pushes the mandrel rod (3) forward and into the tube blank (2), wherein a relative displacement takes place between the fixing unit (12a) and the mandrel rod (3);
• holding the mandrel rod (3) by the fixing unit (12a) if an action point (3c) of the mandrel rod (3) reaches the position of the fixing unit (12a), such that subsequently no relative movement takes place between the fixing unit (12a) and the mandrel rod (3);
• transporting the tube blank (2) with the mandrel rod (3) inserted through the rolling mill (20), such that the tube blank (2) is rolled out on the mandrel rod (3) to form a tube (2′);
• and subsequently
• retracting the mandrel rod (3) from the rolling mill (20) counter to the rolling direction (R) by the retaining device (12).