Method of regulating tension/compression in a multi-frame hot rolling mill, and a corresponding control system
AssigneeAlstom
InventorJoseph Schwedt
Life of this patent
Estimating the term…
Abstract
The value of the rolling torque is measured at each frame through which a metal product passes, and the measurement is performed at the moment when said product reaches the following frame, at which point the frame at which the measurement is performed is switched over to torque regulation. The last frame reached by the product remains in speed regulation and it acts as a controlling frame for all other frames situated upstream therefrom so as to enable them to conserve torque equal to their respective reference torques by adapting their speeds. Once the reference torque measurements have been stored in the control system, regulation is obtained by making use of a distribution key for the stresses between the frames.
Claims4
A method of regulating tension/compression in a multi-frame rolling mill working on hot metal products, wherein, starting from an initial situation while a product is being passed into the various frames of the run, torque is measured at each frame through which the product passes at the moment when said product reaches the following frame downstream therefrom, the measured value is stored as a reference value, and the frame for which the measurement is made is switched from speed regulation to torque regulation, and wherein the last frame into which the product enters acts as a speed controlling frame for all other frames situated upstream therefrom, thereby retaining torque equal to the reference torque by varying the speed.
A control system for a multi-frame rolling mill working on hot metal products, in which the frames are controlled by programmed logic control units, the control units being controlled by at least one common supervisor unit, the system including hardware and software for:
- measuring the value of the torque, at each frame through which a product passes, at the moment when said product reaches the following frame downstream therefrom;
- switching from speed regulation to torque regulation for the frame through which said product is passing when the product reaches the following frame downstream therefrom;
- and
- activating the last frame through which the product passes as a speed-controlling frame for all other frames situated upstream therefrom.
Dependencies are inferred from the claim text.