Box-Section Rolling Profile Control for Stable Thickness Uniformity
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Solution Overview
Problem
Existing methods struggle to produce box profiles with consistent thickness across the width of rolled metal products while maintaining production stability, often leading to unstable rolling processes and material loss due to concave contours.
Innovation Solution
An operating method that approximates the contour profile of rolled metal products to an ideal profile within an initial central region, ignoring edge drops and adjusting setpoints to ensure stability, using a control device to determine and transmit setpoints to rolling stands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the contour profile is adjusted across the entire width to achieve a box profile, then the thickness consistency is improved, but the rolling process stability deteriorates due to concave contours
Solution Approach 1:
The patent divides the strip width into a central region and edge regions, applying different contour control strategies to each segment. The central region is optimized for box profile (constant thickness) while the edge regions are allowed to have natural thickness variation, preventing concave contours and maintaining rolling stability.
Solution Approach 2:
Different quality requirements are applied to different regions: the central region requires high thickness consistency for box profile, while the edge regions accept natural thickness variation. This localized approach allows box profile production without compromising overall process stability.
2Manufacturing precision
If the desired profile value is reduced to produce box profiles, then the thickness uniformity is improved, but the production stability worsens due to material loss and equipment damage
Solution Approach 1:
The control strategy segments the strip width into central and edge zones, applying box profile control only to the central region where it is most beneficial, while allowing edge regions to maintain natural thickness profiles, thereby avoiding the instability and damage associated with extreme profile control.
Solution Approach 2:
Instead of applying full contour control across the entire width, the patent applies partial action by limiting box profile control to the central region only. This partial approach achieves sufficient thickness uniformity for box profiles while avoiding the excessive control that leads to concave contours and production instability.
Data Source
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AI summary
According to the invention, a control device (3) receives actual variables (I) of a flat rolled product (2) before rolling and target variables (Z) of the rolled product (2) after rolling in a rolling mill. The target variables (Z) comprise at least one profile value (C) of the rolled product (2), which relates to a predetermined spacing (a) from the edges of the rolled product (2). The control device (3) determines an ideal contour shape (ci) on the basis of the target variables (Z). On the basis of the actual variables (I) and the ideal contour shape (ci), said device uses a model (6) of the rolling mill to determine target values (COM) for manipulated variables for the roll stands (1) of the rolling mill. The device transfers the target values (COM) to the roll stands (1), such that the rolled product (2) is rolled in the rolling mill in consideration of the target values (COM). The control device (3) determines the target values (COM) such that an expected contour shape (ce) of the rolled product (2) after rolling is approximated as far as possible to the ideal contour shape (ci) exclusively or at least primarily in a central region (11) as viewed over the rolled product width (b). The central region (11) extends towards the edges of the rolled product (2) up to region boundaries (12) which have a greater spacing from the edges of the rolled product (2) than the predetermined spacing (a).