Rolling Mill Tail-End Control Using Separation Timing and Strip Velocity
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Solution Overview
Problem
Existing reverse-type rolling apparatuses face challenges in improving yield while minimizing the time required for rolling, particularly in accurately stopping the tail end of a strip at a suitable position for the next pass, which can lead to inefficiencies and losses.
Innovation Solution
A control device and method that includes a rotation control unit to stop mill rolls based on the detection of strip separation and velocity, using sensors to detect strip presence and separation, and a gripping control unit to release the strip at the appropriate time, ensuring smooth transitions between rolling passes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If rolling is continued even after the tail end of the strip separates from the unwinder, then yield is improved, but the time required for rolling increases due to the need to accurately stop and position the strip for the next pass
Solution Approach 1:
The control device performs preliminary actions by detecting strip separation timing and velocity before the actual stop is needed, calculating the optimal stop position in advance, and preparing the mill rolls for controlled deceleration. This allows the rolling process to continue maximizing yield while the system is already prepared for the necessary stop, reducing the overall time penalty.
Solution Approach 2:
The control device uses real-time feedback from strip separation detection and velocity measurement to dynamically adjust the stop timing and position. By continuously monitoring strip velocity and separation events, the system can optimize the stop point to minimize idle time while ensuring accurate positioning for the next pass, thus reducing the time loss associated with yield-improving continuous rolling.
2Ease of operation
If the tail end of the strip is stopped accurately at a suitable position for the next pass, then smooth transitions are achieved, but the complexity of the control system increases
Solution Approach 1:
The patent replaces complex mechanical positioning systems with a control-based approach using sensors and computational algorithms. Instead of mechanical devices to physically position the strip, the system uses velocity acquisition units and separation detection units to measure strip parameters, then computationally determines optimal stop positions and controls mill roll deceleration accordingly, reducing mechanical complexity while achieving smooth transitions.
Solution Approach 2:
The control device enables the rolling system to self-regulate its stopping and positioning operations autonomously. The system automatically detects strip separation, measures velocity, calculates optimal stop positions, and executes controlled deceleration without requiring external intervention or complex mechanical assistance, simplifying the overall control architecture while maintaining smooth transitions.
Data Source
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AI summary
A control device for a rolling apparatus is a control device for controlling a rolling apparatus including a pair of mill rolls for rolling a metal strip, an unwinder for unwinding the strip toward the pair of mill rolls, and a winder for winding the strip rolled by the pair of mill rolls, including a rotation control unit for controlling rotation of the mill rolls, a velocity acquisition unit configured to acquire velocity of the strip between the unwinder and the mill rolls, and a separation detection unit configured to detect separation of a tail end of the strip from the unwinder. The rotation control unit is configured to stop the rotation of the pair of mill rolls, based on a separation timing which is a timing when the separation of the tail end from the unwinder is detected by the separation detection unit and the velocity of the strip acquired by the velocity acquisition unit.