Sheet Metal Preform Calibration With Excess Edge Material

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional deep drawing processes for sheet metal components face challenges such as springback, sensitivity to batch fluctuations, and the need for additional trimming operations, leading to dimensional inaccuracies and increased costs due to material wastage and complex tooling requirements.

Innovation Solution

A method and device that produce sheet metal preforms with a positive dimensional deviation near the edge, allowing for repeatable geometry and sufficient excess material for subsequent calibration, reducing the need for final edge trimming and minimizing the impact of batch changes and tool wear.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If conventional deep drawing is used to produce sheet metal components, then complex geometries can be formed with high material strength, but the component exhibits springback and sensitivity to batch fluctuations leading to dimensional inaccuracies

Engineering Contradiction:
Improvematerial strengthVSAvoiddimensional accuracy
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The method applies preliminary action by intentionally creating a positive dimensional deviation (excess material) in the preform edge area before the final calibration step. This pre-planned excess material compensates for the springback that will occur after forming, ensuring that the final component achieves the target dimensional accuracy despite the inherent springback behavior of high-strength materials.

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If straightening and/or calibration processes are added to compensate for springback, then dimensional accuracy improves, but process complexity and tooling requirements increase

Engineering Contradiction:
Improvedimensional accuracyVSAvoidtool complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The calibration tool is designed with a predetermined geometric deviation that matches the expected springback. This preliminary configuration allows the calibration step to simply press the component against the calibrated surface, automatically compensating for springback without requiring complex adaptive control systems or multiple adjustment steps.

Inventive Principle:
Principle #10Preliminary action

3Manufacturing precision

If edge trimming is performed separately after deep drawing, then the edge contour precision improves, but material utilization decreases and additional logistics systems are required

Engineering Contradiction:
Improveedge contour precisionVSAvoidmaterial utilization
Core Design Contradiction:
Manufacturing precisionVSLoss of substance

Solution Approach 1:

The method merges the trimming function into the calibration step. The calibration tool simultaneously performs two functions: (1) calibrates the component geometry by pressing it against the predetermined calibration surface, and (2) trims the excess material at the edges. This integration eliminates the need for a separate trimming operation, improving material utilization while maintaining edge contour precision.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The calibration tool is designed as a multi-functional device that performs both calibration and trimming operations in a single step. The calibration surface serves dual purposes: establishing the final geometry and defining the edge contour. This universal tool reduces device complexity and eliminates additional logistics systems that would be required for separate trimming operations.

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Loss of substance

If the preform edge area is trimmed to exact dimensions, then material waste is reduced, but insufficient excess material remains for subsequent calibration

Engineering Contradiction:
Improvematerial wasteVSAvoidcalibration accuracy
Core Design Contradiction:
Loss of substanceVSManufacturing precision

Solution Approach 1:

The method applies local quality by maintaining different material conditions in different areas of the preform. The central area is calibrated to precise dimensions, while the edge area intentionally retains a positive dimensional deviation (excess material). This localized differentiation ensures that sufficient material remains at the edges for the calibration process to work effectively, while minimizing overall material waste.

Inventive Principle:
Principle #3Local quality

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

Ensures reliable processing of sheet metal preforms with consistent geometry, reducing the need for additional shaping steps and maintaining dimensional accuracy, while minimizing material waste and tool complexity.

Implementation Method 1

a preferably flat blank is clamped between a blank holder or blank holder and a drawing ring or die support surface, and then drawn into a die via a punch

Methodology Applied
Scientific EffectPlastic deformation: Plasticity

Implementation Method 2

the friction between the sheet and the blank holder is adjusted using a coordinated blank holder force or other measures such as draw beads or similar

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3565677B1Method for producing sheet metal components and device therefor
Publication Date: 2024.07.24 THYSSENKRUPP AG
  • EP3565677B1 patent drawingFigure 1~4b
  • EP3565677B1 patent drawingFigure 5~6

AI summary

The present invention relates to a method for producing a dimensionally stable sheet metal component (3, 3', 3''), wherein the method comprises the following steps: - preforming sheet metal (1) into a sheet metal preform (2) having at least one base region (2.1), a frame region (2.2), a transitional region (2.4) between the base region and the frame region, optionally a flange region (2.3) and a transitional region (2.5) between the frame region and the flange region, wherein at least one of the regions (2.1, 2.2, 2.3, 2.4, 2.5) has at least in parts excess material (4, M); - cutting at least in parts the sheet metal preform (2) into a cut sheet metal preform (2') having a sheet metal preform edge (2'.31); and - swaging and/or calibrating the sheet metal preform (2') which has been cut at least in parts into a substantially finished formed sheet metal component (3, 3', 3'').