Three-Roller Sheet Bending Control for Springback Prediction

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Solution Overview

Problem

Three-roll bending machines face the challenge of material springback after rolling, requiring time-consuming posterior corrections or pre-treatment calibrations, which are costly and wasteful, as they necessitate additional material usage.

Innovation Solution

A method to determine the number of passages and successive positioning of lower rollers in a three-roll bending machine based on the desired radius of curvature, material characteristics, and thickness, using a simulation table and regression processing to predict and achieve the desired curvature without pre-treatment calibration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If pre-treatment calibration is performed to predict curvature, then manufacturing precision is improved, but loss of time and loss of substance increase due to sacrificing material sheets

Engineering Contradiction:
Improvecurvature prediction accuracyVSAvoidcalibration time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent performs preliminary simulation and calculation of roller positioning based on material characteristics and desired curvature before actual rolling. The control unit pre-determines the optimal positions of lower rollers using simulation data, eliminating the need for time-consuming trial-and-error calibration passes.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent replaces physical trial-and-error calibration with computational simulation and mathematical calculation. Instead of using actual material sheets to calibrate the machine through successive rolls, the system uses simulation tables and regression analysis to calculate precise roller positions directly.

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

2Manufacturing precision

If posterior correction is performed after rolling, then manufacturing precision is improved, but loss of time and loss of substance increase due to requiring additional passes and material

Engineering Contradiction:
Improveradius of curvature accuracyVSAvoidrolling efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent performs preliminary simulation and calculation of roller positioning based on material characteristics and desired curvature before actual rolling. The control unit pre-determines the optimal positions of lower rollers using simulation data, eliminating the need for time-consuming trial-and-error calibration passes.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent incorporates feedback from simulation results and measured springback characteristics to automatically adjust roller positioning calculations. The system uses regression analysis of simulation data to refine predictions and compensate for material-specific springback behavior without requiring physical trial passes.

Inventive Principle:
Principle #23Feedback

3Manufacturing precision

If calibration positions are determined through successive rolls, then manufacturing precision is improved, but loss of substance increases due to sacrificing each calibration sheet

Engineering Contradiction:
Improvespringback prediction accuracyVSAvoidmaterial waste
Core Design Contradiction:
Manufacturing precisionVSLoss of substance

Solution Approach 1:

The patent replaces physical trial-and-error calibration with computational simulation and mathematical calculation. Instead of using actual material sheets to calibrate the machine through successive rolls, the system uses simulation tables and regression analysis to calculate precise roller positions directly.

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

Solution Approach 2:

The patent creates virtual copies of the rolling process through finite element simulation to predict material behavior. The simulation model replicates the physical rolling process and springback characteristics without consuming actual material, allowing virtual calibration that can be applied to real production.

Inventive Principle:
Principle #26Copying

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 precise control of the bending process, reducing material waste and time consumption by directly calculating the necessary roller positions to achieve the desired radius of curvature, thus minimizing springback and optimizing the rolling process.

Implementation Method 1

a sheet, for example of steel, is introduced between an upper roller and two lower rollers... The more the lower rollers are adjusted in the high position, the more the radius of curvature of the sheet decreases

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

One of the main technical problems encountered by the users of such installations lies in the phenomenon of elastic return of the sheet, after having undergone the rolling step

Methodology Applied
Scientific EffectSpringback: Elastic Recovery

Data Source

PatentEP3502816B1Method for adjusting a rolling machine with three rollers
Publication Date: 2021.11.24 AMB PICOT
  • EP3502816B1 patent drawingFigure 1
  • EP3502816B1 patent drawingFigure 2
  • EP3502816B1 patent drawingFigure 3

AI summary

This method for determining the number of passes as well as the successive positionings of the two lower rollers (5, 6) in relation to the fixed central upper roller (4) of a three-roller rolling machine as a function of the desired radius of curvature, the nature and thickness of a sheet to be bent, in order to obtain said radius of curvature, or to determine the bending radius or rolling diameter of a metal sheet as a function of the nature and thickness of the sheet, after passing through such a rolling machine, consists of: - generating a finite element simulation table as a function of the characteristics of the rolling machine, the elastic limit of the material constituting the sheet to be bent, and the thickness of said sheet, for a determined number of positions of the lower rollers, allowing the rolled diameter of the sheet to be defined for each of said positions;- then, to introduce into a processing and control unit of said three-roll rolling machine, among the adjustment parameters of the rolling machine, the positioning of the lower rollers resulting from this table after mathematical processing, in particular by regression of the function D = f(p), in which D designates the rolled diameter of the sheet and p the positioning of the lower rollers (5, 6), in order to define for the last passage of the sheet considered in the rolling machine, the desired radius of curvature of the sheet.;