Method for automatically calibrating vertical rollers of a vertical roller frame and calibration arrangement for carrying out said method

A calibration arrangement on a vertical rolling stand in a rolling train for rolling metal products, having at least two vertical rolls which are each mounted in vertical roll units of a plurality of vertical roll units, wherein the plurality of vertical roll units define a rolling gap and wherein the plurality of vertical roll units are adjustable by at least one adjustment system and/or at least one return system with respect to a predetermined center line of several components arranged in the rolling train,

• wherein the calibration arrangement comprises at least one first reference surface of a defined position on one of:
• at least one vertical roll unit in the plurality of vertical roll units, or on a component which is movable with the at least one vertical roll unit,
• wherein the calibration arrangement comprises at least one second reference surface stationary with respect to the center line, and a control system (S) by which, with at least one position sensor (PG) of the at least one adjustment system and/or of the at least one return system, an adjustment of the plurality of vertical roll units is configured to be effected transversely to the center line against the at least one second reference surface as a stationary stop of the vertical rolling stand for determining a calibrated starting position and for calculating a calibrated initial distance (Akal) between an outer edge of a vertical roll in the at least two vertical rolls that is directed towards a rolled stock and the center line or between a center line of the vertical roll in the at least two vertical rolls and the center line, and for determining an adjustment of the plurality of vertical roll units into a defined rolling position.