Flat Conductor Lap Joint Using Friction Stir Welding

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Solution Overview

Problem

Joining different metallic materials, particularly when aluminum is involved, results in problematic contact resistance and damage to previously formed intermetallic bonds during ultrasonic welding of electrical connections in flat conductors.

Innovation Solution

A connection arrangement using friction stir welding to form a continuous metallurgical bond between a flat conductor and connecting tabs, ensuring stable and permanent connections by plasticizing the materials and forming an intermetallic bond through a friction stir welding zone that extends along the longitudinal axis of the conductor, allowing multiple connections to be made simultaneously.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If ultrasonic welding is used to form intermetallic joints between different metals, then electrical connection quality is improved, but subsequent welding operations damage previously formed bonds

Engineering Contradiction:
Improveelectrical connection qualityVSAvoidintegrity of previously formed welds
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent segments the welding process into distinct spatial zones by positioning multiple terminal tabs at different locations along the flat conductor, allowing sequential welding without mutual interference. Each weld zone is separated from others, preventing vibration-induced damage to adjacent welds.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies preliminary protective measures by designing the welding fixture and tooling to isolate and dampen ultrasonic vibrations during each welding operation. This preliminary protection prevents vibration transmission to previously formed welds, maintaining their integrity throughout the multi-step process.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If multiple terminal tabs are welded sequentially along the flat conductor, then electrical connections are established, but welding vibrations compromise previous welds

Engineering Contradiction:
Improvenumber of connections per conductorVSAvoidweld bond integrity
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent introduces intermediary elements including vibration-damping fixtures, clamping mechanisms, and tooling designs that act as mediators between the ultrasonic welding source and previously formed welds. These intermediaries absorb or isolate vibration energy, allowing multiple tabs to be welded sequentially without compromising bond integrity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent implements beforehand cushioning by incorporating vibration-damping features and protective fixtures before the welding process begins. These measures cushion against the harmful effects of ultrasonic vibrations on previously formed welds, enabling high productivity while maintaining reliability.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Adaptability or versatility

If different metallic materials are joined to create mixed-material flat conductors, then electrical power distribution capability is improved, but contact resistance at connection points increases

Engineering Contradiction:
Improveelectrical power distribution capabilityVSAvoidcontact resistance at connection points
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies parameter changes by optimizing the ultrasonic welding parameters (amplitude, pressure, time, temperature) specifically for joining different metallic materials. By adjusting these parameters, the process achieves low-contact-resistance intermetallic bonds between dissimilar metals, enabling versatile power distribution while maintaining connection reliability.

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

The solution provides a stable and permanent intermetallic bond between different metallic materials, preventing damage to previous welds and ensuring low contact resistance, enabling multiple connections to be made efficiently and reliably.

Implementation Method 1

friction stir welding to form a continuous metallurgical bond between a flat conductor and connecting tabs

Methodology Applied
Scientific EffectFriction stir welding: Friction Welding

Implementation Method 2

plasticizing the materials and forming an intermetallic bond through a friction stir welding zone

Methodology Applied
Scientific EffectPlasticization: Plasticity

Data Source

PatentEP4147305B1Connection arrangement and method for producing a connection arrangement
Publication Date: 2026.06.24 ONE MOBILITY AUTOKABEL GMBH
  • EP4147305B1 patent drawingFigure 1a~1b
  • EP4147305B1 patent drawingFigure 2a~2d
  • EP4147305B1 patent drawingFigure 3

AI summary

The invention relates to a connection arrangement comprising a metal flat conductor having an at least quadrangular cross-sectional profile and at least two opposing first and second surfaces which extend in parallel with each other at least in part in the longitudinal direction, and at least two parts which are formed as connection lugs, are flat in the region of overlap, rest on the first surface with a lap joint and protrude beyond one or both long edges of the flat conductor, characterised in that a metal friction stir welding joining zone is formed starting from the second surface, extending through the flat conductor towards the first surface and protruding into the connection lugs.