Flexible Rolling of Wide Metal Strips With Force-Based Roll Bending

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Solution Overview

Problem

Existing methods struggle to efficiently manufacture metal strips with widths over 650 mm, as conventional mills face difficulties in achieving precise thickness profiles and flatness control, especially in achieving varying thicknesses over the length of the strip.

Innovation Solution

The method involves a two-step process: a 'learning phase' where parameter values for thickness and flatness are stored during rolling, and a 'program-loop' phase where these values are used to optimize the rolling process, allowing for flexible rolling with the bending of work rolls based on rolling forces rather than roll gap settings, enabling the production of metal strips with varying thicknesses and widths up to 1600 mm.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional mills are used to manufacture metal strips with width over 650 mm, then the manufacturing capability is limited, but the production efficiency and precision are insufficient

Engineering Contradiction:
Improvemanufacturing capability for wide stripsVSAvoidthickness profile precision
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The invention applies dynamic control of rolling forces and work roll bending during the rolling process. The rolling forces are continuously adjusted based on real-time measurements of thickness and flatness, allowing the system to adapt to varying strip properties and achieve precise thickness profiles for wide strips (over 650 mm) that conventional static mills cannot handle

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention implements a closed-loop feedback control system using laser measurements to continuously monitor thickness and flatness during rolling. The measured values are fed back to adjust rolling forces and work roll bending in real-time, enabling precise control of thickness profiles for wide strips and resolving the contradiction between manufacturing capability and precision

Inventive Principle:
Principle #23Feedback

2Ease of operation

If the rolling process uses fixed roll gap settings, then the control is simple, but the ability to achieve varying thicknesses over strip length is limited

Engineering Contradiction:
Improvecontrol simplicityVSAvoidthickness variation capability
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The invention transitions from static roll gap settings to dynamic control where rolling forces and work roll bending are continuously adjusted during the rolling process. This allows the system to achieve varying thicknesses over the strip length while maintaining operational simplicity through automated control based on laser measurements

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the control parameter from fixed roll gap setting to variable rolling forces and work roll bending. By adjusting these parameters in real-time based on measured thickness and flatness, the system can achieve complex thickness profiles while keeping the control system manageable through automated feedback

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If the work roll bending is based on roll gap setting, then the process is straightforward, but the flatness control precision is insufficient

Engineering Contradiction:
Improveprocess simplicityVSAvoidflatness control precision
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The invention replaces roll gap-based work roll bending with a feedback-controlled system that uses laser measurements of thickness and flatness to determine the required bending. This closed-loop approach achieves high flatness control precision while maintaining process simplicity through automated control algorithms

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The invention substitutes the mechanical roll gap setting system with an optical measurement and force-based control system. Laser measurements replace mechanical gauges, and controlled rolling forces replace mechanical adjustment mechanisms, achieving superior flatness precision while keeping the overall process straightforward

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Device complexity

If conventional rolling methods are used for wide strips, then the equipment is simple, but the production efficiency and scrap rate are problematic

Engineering Contradiction:
Improveequipment simplicityVSAvoidproduction efficiency
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The invention implements real-time laser measurement and feedback control during rolling of wide strips, enabling immediate detection and correction of thickness deviations. This prevents scrap generation and improves production efficiency without requiring significantly more complex equipment than conventional mills

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system uses automated feedback control to self-correct thickness and flatness deviations during the rolling process, eliminating the need for manual intervention and reducing scrap rates. The equipment remains relatively simple while achieving high productivity through intelligent control

Inventive Principle:
Principle #25Self-service

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach enhances production efficiency by reducing scrap, enabling better nesting and shorter processing times, and allows for the production of metal strips with complex profiles, suitable for weight reduction in automotive and transportation industries, while maintaining high quality and strength.

Implementation Method 1

at least one upper and at least one lower roll adjoin the upper and the lower surface of the metal strip under the influence of pressure

Methodology Applied
Scientific EffectPressure: Pressure Increase

Implementation Method 2

The method involves a two-step process: a 'learning phase' where parameter values for thickness and flatness are stored during rolling

Methodology Applied
Scientific EffectDeformation: Deformation

Implementation Method 3

The invention is based on the bending of the work rolls, which is depending on the forces like it is mentioned in Patent JP 61-172603 and likewise not on the setting of the rolling gap

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3342494B1Method and device for flexible rolling metal strips
Publication Date: 2023.06.07 OUTOKUMPU OY
  • EP3342494B1 patent drawingFigure 1~2

AI summary

The invention relates to a method for manufacturing flexible rolling of metal strips, in which a metal strip with predefinable material thickness consisting is guided through a mill stand by at least two operating steps, which is containing several rolls, the metallic strip is during the rolling operation set to lead through a roll gap, where the curve bending line is steered to achieve a defined profiles.