Lubricant Application Device for Metal Strip Flatness Control

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Solution Overview

Problem

Existing methods for regulating the flatness and roughness of metal strips in cold rolling stands do not allow for precise control over lubricant application, leading to suboptimal quality in the final product and potential issues like rust or strip misalignment.

Innovation Solution

A method and device for metering lubricant application across the width of the metal strip at the inlet of the cold rolling stand, using a nozzle bar with individually adjustable nozzles and a mixer to control the lubricant composition, ensuring precise distribution based on actual and target flatness and roughness deviations, with minimal residual lubricant to prevent rust and misalignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If lubricant is applied as a lump sum to the inlet side of the cold rolling stand, then the application process is simple, but the flatness and roughness control of the metal strip is imprecise

Engineering Contradiction:
Improveflatness and roughness controlVSAvoidlubricant application system
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The lubricant application device is divided into multiple individually controllable nozzles arranged across the width of the metal strip. Each nozzle can be independently controlled to apply lubricant at different rates, enabling precise local adjustment of friction coefficients to achieve desired flatness and roughness distribution across the strip width.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different sections of the metal strip width receive different amounts of lubricant based on their specific requirements. The system applies lubricant non-uniformly across the width, with each width section receiving a customized amount to achieve predetermined target flatness and roughness values for that specific location.

Inventive Principle:
Principle #3Local quality

2Manufacturing precision

If more lubricant is applied to improve flatness and roughness, then the quality of cold-rolled metal strip improves, but the risk of rust formation increases due to higher residual lubricant content

Engineering Contradiction:
Improveflatness and roughness qualityVSAvoidrust formation risk
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The system incorporates feedback control by measuring the actual flatness and roughness of the metal strip and comparing it with target values. Based on the deviations detected, the system automatically adjusts the lubricant application rate at different width sections to achieve the desired quality while minimizing excess lubricant application that would lead to rust formation.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

Instead of applying lubricant uniformly across the entire width, the system applies lubricant selectively and only in the amounts needed for each specific width section. This partial action approach ensures sufficient lubrication for quality control while avoiding excessive lubricant application that would remain as residue and cause rust.

Inventive Principle:
Principle #16Partial or excessive action

3Manufacturing precision

If lubricant application is increased to control friction in the roll gap, then the flatness improves, but the residual lubricant causes the metal strip to run sideways on the roller table

Engineering Contradiction:
Improveflatness controlVSAvoidstrip handling stability
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The lubricant application is segmented into multiple independently controlled nozzles across the strip width. This allows the system to apply lubricant only where needed for friction control during rolling, rather than applying it uniformly across the entire width, thereby preventing excess lubricant from causing the strip to slide on the roller table downstream.

Inventive Principle:
Principle #1Segmentation

4Manufacturing precision

If the amount of lubricant applied is increased, then the coefficient of friction in the roll gap is better controlled for desired flatness, but the quantity of lubricant waste increases

Engineering Contradiction:
Improvecoefficient of friction controlVSAvoidlubricant waste
Core Design Contradiction:
Manufacturing precisionVSLoss of substance

Solution Approach 1:

The system applies lubricant in the minimum necessary amounts at each width section to achieve the desired friction control and flatness. By avoiding excessive lubricant application, the system prevents waste while maintaining effective friction control in the roll gap for quality production.

Inventive Principle:
Principle #16Partial or excessive action

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 allows for targeted adjustment of the coefficient of friction, improving the flatness and roughness of the metal strip, minimizing waste and ensuring the lubricant level remains within safe thresholds to prevent rust and misalignment, thus enhancing the quality and safety of the rolled metal.

Implementation Method 1

the amount of at least one lubricant applied to the metal strip per unit of time at the inlet of the cold rolling stand

Methodology Applied
Scientific EffectLubrication: Lubrication

Data Source

PatentEP2125257B1Method and lubricant application device for regulating the planarity and/or roughness of a metal strip
Publication Date: 2013.03.27 SMS GROUP GMBH
  • EP2125257B1 patent drawingFigure 1
  • EP2125257B1 patent drawingFigure 2
  • EP2125257B1 patent drawingFigure 3

AI summary

The invention relates to a method and a lubricant application device (100) for regulating the planarity and/or roughness of a metal strip (400) in the run-out of a cold rolling stand by suitable metering of the amount of at least one lubricant per unit of time applied to the metal strip (400) in the run-in of the cold rolling stand. To further improve the quality of cold-rolled metal strip with regard to its planarity and/or roughness, it is proposed according to the invention that the applied amount of lubricant is metered in the form of a distribution of the quantity over the width of the metal strip per unit of time in accordance with an established deviation between an actual planarity distribution and a set planarity distribution over the width of the metal strip in the run-out of the cold rolling stand or a deviation between an actual roughness distribution and a set roughness distribution over the width of the metal strip in the run-out of the cold rolling stand (100) or a combination of the two deviations.