Friction-Welded Connection Element for Drill-Free Composite Fastening

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Solution Overview

Problem

Existing methods for attaching components made of fiber-reinforced composite materials, such as CFRP, face challenges like fiber disruption and delamination due to drilling, and adhesive fastening technologies are inefficient for automated series production.

Innovation Solution

A two-part connecting element with a base part and a functional part, where the base part has an annular bead for friction welding, allowing for hole-less attachment and flexible adaptation to various fastening tasks, using a base part with a bead for friction welding and a functional part with a shaft and head for tensile force transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If drilling is used to attach fasteners to fiber-reinforced composite components, then fastening is achieved, but fiber disruption and delamination occur reducing load-bearing capacity

Engineering Contradiction:
Improvefastening processVSAvoidload-bearing capacity
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The patent replaces the mechanical drilling system with a friction welding system that uses rotational friction heat to join the base part to the composite component surface, eliminating fiber disruption and delamination while achieving strong attachment

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

Solution Approach 2:

The patent changes the joining parameters from mechanical removal (drilling) to thermal-mechanical bonding (friction welding), where the bead material undergoes phase change and flow during welding to create a strong bond without damaging the composite structure

Inventive Principle:
Principle #35Parameter changes

2Strength

If adhesive bonding is used to attach fasteners to avoid drilling, then fiber disruption is avoided, but curing time is long and automation is difficult

Engineering Contradiction:
Improvefiber integrityVSAvoidcuring time
Core Design Contradiction:
StrengthVSProductivity

Solution Approach 1:

The patent replaces the chemical adhesive bonding process with a mechanical-thermal friction welding process, eliminating long curing times and enabling automated production while maintaining fiber integrity

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

Solution Approach 2:

The patent utilizes phase transition of the bead material during friction welding, where friction heat melts and flows the thermoplastic material to create bonding, replacing the chemical curing process with a rapid thermal-mechanical process suitable for automation

Inventive Principle:
Principle #36Phase transitions

3Adaptability or versatility

If a two-part design with base part and functional part is used, then adaptability to various fastening tasks is improved, but device complexity increases

Engineering Contradiction:
Improvefastening task adaptabilityVSAvoidconnecting element structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent divides the connecting element into a base part for friction welding attachment and a functional part for various fastening functions, allowing independent optimization of each part and enabling multiple fastening applications with a single base part design

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent creates a universal base part that can be combined with different functional parts (snap connection, screw connection, etc.) to achieve multiple fastening tasks, reducing overall system complexity through standardization

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

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

Enables process-reliable, automated, and cost-effective attachment of components without material restrictions, allowing for flexible design and adaptation to different applications, ensuring high strength and resilience while avoiding fiber disruption and delamination.

Implementation Method 1

for fastening to the surface of a component by friction welding

Methodology Applied
Scientific EffectFriction welding: Friction Welding

Implementation Method 2

The bead 'provides' the welding allowance during friction welding

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4077953B1Connection element for securing to a component via friction welding
Publication Date: 2024.11.06 EJOT SE & CO KG
  • EP4077953B1 patent drawingFigure 1a
  • EP4077953B1 patent drawingFigure 1b
  • EP4077953B1 patent drawingFigure 2~3

AI summary

The invention relates to a connection element for securing to a component, in particular a component made of a fibre composite material, comprising a main part, a functional part and a friction welding inlay, which in turn comprises a thermoplastic material. A tool application point is formed on an upper side of the main part. The friction welding inlay is interlockingly and/or force-lockingly connected to the main part.