Elastomeric Stamp Forming Tools for Uniform Pressure on Large Parts

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Solution Overview

Problem

Current stamp forming technologies using metal die sets face challenges in achieving uniform pressure distribution for large-scale parts, leading to material consolidation issues and void formation, with elastomeric inserts deteriorating quickly under thermal and mechanical stress, requiring frequent and costly replacements.

Innovation Solution

The use of a tooling set with an elastomeric layer positioned between stamping tools to deform and balance pressures during the stamp forming process, allowing for more uniform pressure distribution and improved part quality, while the elastomeric layer can be removably secured and designed for different stamping tool geometries and materials.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If matched metal die sets are used for stamp forming large-scale parts, then structural strength and rigidity are improved, but uniform pressure distribution deteriorates leading to material consolidation issues and void formation

Engineering Contradiction:
Improvestructural strengthVSAvoiduniform pressure distribution
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The patent replaces rigid metal die sets with flexible elastomeric stamping tools that can conform to the workpiece surface. The elastomeric material deforms under compression to distribute pressure uniformly across the part surface, eliminating void formation and material consolidation issues while maintaining the necessary forming capability for large-scale parts

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The patent changes the material parameter of the stamping tool from rigid metal to compliant elastomeric material. This parameter change allows the tool to adapt its surface geometry and pressure distribution characteristics, transforming the pressure application mechanism from fixed and non-uniform to dynamic and uniform across the contact surface

Inventive Principle:
Principle #35Parameter changes

2Reliability

If stamping pressure is increased to overcome nonuniform pressure distribution, then material consolidation is improved, but part thinning becomes excessive

Engineering Contradiction:
Improvematerial consolidationVSAvoidpart thinning
Core Design Contradiction:
ReliabilityVSShape

Solution Approach 1:

The elastomeric stamping tool inherently provides uniform pressure distribution through its compliant nature, achieving adequate material consolidation without requiring excessive stamping pressure. This eliminates the need to trade off between consolidation quality and part thinning, as the flexible tool naturally adapts to the workpiece geometry and applies pressure evenly throughout the forming process

Inventive Principle:
Principle #30Flexible shells and thin films

3Manufacturing precision

If elastomeric inserts are used in stamp forming tools, then uniform surface pressures are achieved, but insert lifespan deteriorates due to rapid deterioration under thermal and mechanical environment

Engineering Contradiction:
Improveuniform surface pressureVSAvoidinsert lifespan
Core Design Contradiction:
Manufacturing precisionVSDuration of action of stationary object

Solution Approach 1:

The patent modifies the operational parameters of the elastomeric material by pre-heating it to above its glass transition temperature before stamping. This parameter change transforms the material from a rigid state to a more compliant state that better distributes pressure uniformly while reducing stress concentrations that lead to deterioration, thereby extending insert lifespan

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies preliminary heating to the elastomeric insert before the actual stamping operation. This preliminary action prepares the material by raising its temperature above the glass transition point, making it more compliant and durable during the subsequent forming process, thus preventing rapid deterioration and extending service life

Inventive Principle:
Principle #10Preliminary action

4Manufacturing precision

If elastomeric inserts are replaced frequently to maintain part quality, then manufacturing precision is maintained, but productivity decreases due to time-consuming and expensive replacements

Engineering Contradiction:
Improvepart qualityVSAvoidmanufacturing efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

By pre-heating the elastomeric insert above its glass transition temperature, the material becomes more compliant and durable, maintaining uniform pressure distribution and part quality over extended periods. This parameter change reduces the frequency of insert replacement, thereby improving productivity without sacrificing manufacturing precision

Inventive Principle:
Principle #35Parameter changes

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 the producibility of large-scale parts by maintaining uniform pressure, reducing void formation, and extending the lifespan of elastomeric inserts, thereby improving manufacturing efficiency and reducing replacement costs.

Implementation Method 1

an elastomeric layer that deforms during compression of a workpiece. The elastomeric layer(s) balancing pressures on the workpiece

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

The demanding thermal and mechanical environment encountered during part consolidation results in rapid deterioration of the elastomeric inserts

Methodology Applied
Scientific EffectViscoelasticity: Viscoelasticity

Data Source

PatentEP4461518A1Tooling sets, systems and methods for stamp forming a workpiece
Publication Date: 2024.11.13 THE BOEING CO
  • EP4461518A1 patent drawingFigure 1
  • EP4461518A1 patent drawingFigure 2
  • EP4461518A1 patent drawingFigure 3~5

AI summary

A tooling set (100) for stamp forming a workpiece (102) includes a first stamping tool (104), a second stamping tool (110) and an elastomeric layer (114) between the first and second stamping tools. The first stamping tool (104) defines a first forming face (108). The second stamping tool (110) defines a second forming face (112). The elastomeric layer (114) defines first and second compliant stamping surfaces (116, 118). A method for stamp forming a workpiece includes positioning a workpiece between the first stamping tool and the elastomeric layer and compressing the workpiece between the first forming face and the first compliant stamping surface in response to the first and second stamping tools being approximated. A system for stamp forming a workpiece includes the tooling set.