Measurement device for roll gap control and process for its operation

A rolling or continuous casting and rolling mill facility, comprising:

• a roll set comprising working rolls defining a roll gap therebetween and support rolls, at least one of the working rolls and the support rolls having coaxial reduced diameter barrel portions defining measurement surfaces thereon;
• measuring means for determining the roll gap by measuring a distance between the measurement surfaces, comprising a measurement bracket and at least one contact-free sensor mounted on the measurement bracket;
• means for moving the measurement bracket between a working position wherein the at least one sensor is positioned in a rolling plane drawn through axes of rotation of the working rolls and aligned with at least one of the measurement surfaces and a rest position wherein the measurement bracket and the at least one sensor are withdrawn from the rolling plane;
• and
• wherein the measurement bracket has substantially symmetrical chamfers for centering the measurement bracket relative to the measurement surfaces.

A process for centering a measurement device relative to a roll gap of a rolling or continuous casting and rolling mill, comprising the steps of:

• providing the facility having a roll set comprising working rolls defining a roll gap therebetween and support rolls, at least one of the working rolls and the support rolls having coaxial reduced diameter barrel portions defining measurement surfaces thereon;
• measuring means for determining the roll gap by measuring a distance between the measurement surfaces, comprising a measurement head and a contact-free double sensor positioned on the measurement head;
• and means for moving the measurement head between a working position wherein the double sensor is positioned in a rolling plane drawn through axes of rotation of the reduced diameter barrel portions and aligned with the measurement surfaces and a rest position wherein the measurement head and double sensor are withdrawn from the rolling plane, wherein the measurement head has substantially symmetrical chamfers;
• moving the measurement head from the rest position into the roll gap until the chamfers contact the measurement surfaces;
• applying pressure to the measurement head against the measurement surfaces so that the chamfers urge the measurement head to a centered position relative to the measurement surfaces;
• fixing the measurement head in the centered position;
• and
• returning the measurement head toward the rest position.