Insert Welding Joint With Decoupling Zone for Multi-Material Assembly

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Solution Overview

Problem

Existing methods for multi-material assemblies, such as those in land and air transport, face challenges in efficiently joining components with different properties due to high material costs, weight, and complexity, particularly with electric resistance welding and welding patches, which are large and weaken the parts, and require complex drilling.

Innovation Solution

A method involving an insert with a head and body for electric resistance welding, where a decoupling zone is created around the end part to limit heat transfer and material damage, using a process that includes shaping and integrating the insert into the first part to facilitate multi-material assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If welding patches are used to join multi-material assemblies, then the assembly can be created with different materials, but the heat dissipates before reaching the workpiece and material costs and weight increase

Engineering Contradiction:
Improvemulti-material assembly capabilityVSAvoidheat dissipation
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The welding system is segmented into two distinct components: the welding patch attached to the workpiece and the separate anvil that receives the electrode. This segmentation allows the anvil to be positioned close to the workpiece without requiring the patch to be large, thereby reducing heat dissipation while maintaining multi-material assembly capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The anvil acts as an intermediary component between the electrode and the workpiece. It receives the welding electrode's heat and transfers it directly to the workpiece through close positioning, eliminating the need for large welding patches and reducing heat loss to the surrounding environment.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If welding patches are used to join multi-material assemblies, then the assembly can be created with different materials, but material costs and weight increase

Engineering Contradiction:
Improvemulti-material assembly capabilityVSAvoidassembly weight
Core Design Contradiction:
Adaptability or versatilityVSWeight of moving object

Solution Approach 1:

By separating the welding patch from the anvil, the system allows using smaller, lighter patches that are attached only to the workpiece. The anvil can be a separate, potentially reusable component, reducing the overall weight of the assembly while maintaining the ability to join different materials.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The welding patch can be designed as a simple, inexpensive, and potentially disposable component attached to the workpiece, while the anvil serves as a reusable tool. This approach reduces material costs and assembly weight compared to using large, permanent welding patches.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Adaptability or versatility

If welding patches are integrated into parts, then multi-material assemblies can be created, but large holes must be drilled which weakens the part

Engineering Contradiction:
Improvemulti-material assembly capabilityVSAvoidpart strength
Core Design Contradiction:
Adaptability or versatilityVSStrength

Solution Approach 1:

The system separates the welding patch from the anvil, allowing the patch to be small and attached to the workpiece without requiring large holes. The anvil provides the necessary support structure externally, enabling smaller insertion holes that preserve part strength while maintaining multi-material assembly capability.

Inventive Principle:
Principle #1Segmentation

4Ease of manufacture

If spot welding is used to join metal elements, then the assembly is economical and mechanically efficient, but it is limited to joining elements of the same material

Engineering Contradiction:
Improveassembly economyVSAvoidmaterial compatibility
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The welding patch acts as an intermediary that enables spot welding between dissimilar materials. One patch is attached to each workpiece, and the anvil positions the electrodes to create welds through these patches, allowing economical spot welding of multi-material assemblies by mediating the electrical and thermal connection between different materials.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 robust, fast, and economical multi-material assembly with reduced material costs and weight, using existing resistance welding equipment, while minimizing damage to plastic or composite materials.

Implementation Method 1

the thermal decoupling zone around the end piece, i.e., around the melting point, limits heat transfer to the first part

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 2

electric resistance welding

Methodology Applied
Scientific EffectElectric resistance heating: Joule Heating

Data Source

PatentEP4729224A2Method for joining a first part and a second part via an insert
Publication Date: 2026.04.22 GROJEAN MAXIME
  • EP4729224A2 patent drawingFigure 1A~1C
  • EP4729224A2 patent drawingFigure 2A~2C
  • EP4729224A2 patent drawingFigure 3A~4

AI summary

This method allows the assembly of a first part (10) and a second part by means of an insert (30) comprising a head (31) intended to bear against the first part (10) and a body (32) comprising an end portion (322) intended to be welded to the second part. Before attaching the end portion (322) of the body (32) of the insert (30) to the second part, the method includes a shaping step of the first or second part (10) to create a decoupling zone (50) around this end portion (322).