Friction Stir Welding Shoe for Workpiece Height Differences

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Solution Overview

Problem

Friction stir welding devices struggle with height differences in workpieces due to manufacturing tolerances, leading to edge burrs and electrical flashovers when subjected to high electrical voltage, particularly in underground power line and flat structure welding.

Innovation Solution

A device with a welding shoe featuring a trapezoidal smoothing surface and material guide channels, which reduces edge burrs by smoothing the plasticized material and diverting metal chips, and optionally coated with chromium nitride layers for enhanced performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional friction stir welding devices are used to weld workpieces with height differences, then the welding process can be performed, but edge burrs form and electrical flashovers occur reducing reliability

Engineering Contradiction:
Improvewelding reliabilityVSAvoidedge burrs and electrical flashovers
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The welding shoe is pre-adjusted to compensate for height differences between workpieces before welding begins. The adjustable support surface is positioned to accommodate the thickness variation, preventing edge burr formation and electrical flashovers during the welding process

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The welding shoe parameters (position, angle, support surface height) are adjusted to match the specific height difference between workpieces. This allows the welding process to accommodate varying workpiece dimensions while maintaining weld quality and preventing harmful effects

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If welding is performed on workpieces with height differences up to 2 mm, then manufacturing tolerances are accommodated, but welding quality deteriorates due to edge burrs and flashovers

Engineering Contradiction:
Improveaccommodation of manufacturing tolerancesVSAvoidweld seam quality
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The welding shoe is pre-adjusted to compensate for height differences between workpieces before welding begins. The adjustable support surface is positioned to accommodate the thickness variation, preventing edge burr formation and electrical flashovers during the welding process

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The welding shoe parameters (position, angle, support surface height) are adjusted to match the specific height difference between workpieces. This allows the welding process to accommodate varying workpiece dimensions while maintaining weld quality and preventing harmful effects

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If the welding shoe is fixed in position, then device complexity is reduced, but it cannot accommodate height differences in workpieces

Engineering Contradiction:
Improvewelding device structureVSAvoidaccommodation of workpiece height differences
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The welding shoe is designed with adjustable components that allow dynamic adaptation to different workpiece heights. The support surface can be repositioned vertically and the shoe angle can be adjusted, providing flexibility without requiring a completely complex reconfigurable system

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The welding shoe serves multiple functions: it provides support for the workpiece, compensates for height differences, and maintains proper welding geometry. By integrating these functions into a single adjustable component, device complexity is minimized while adaptability is maximized

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

The solution effectively minimizes edge burrs and prevents electrical flashovers by ensuring a smooth weld seam and efficient material transport, improving the quality and reliability of friction stir welding.

Implementation Method 1

friction heat is generated in the joining area of the materials to be welded by means of the friction between a rotating tool that is simultaneously moved in translation and applied with pressure

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

optionally coated with chromium nitride layers for enhanced performance

Methodology Applied
Scientific EffectFriction reduction through coating: Coatings

Data Source

PatentEP3433047B1Device and method for friction stir welding of workpieces with height differences of joining partner
Publication Date: 2023.07.19 GRENZEBACH MASCHINENBAU GMBH
  • EP3433047B1 patent drawingFigure 1
  • EP3433047B1 patent drawingFigure 2a~2b
  • EP3433047B1 patent drawingFigure 3

AI summary

The invention relates to a method and a device for the residue-free friction stir welding of workpieces with different thicknesses, having the following method steps: a) two workpieces (6) to be welded are mounted such that the workpieces can be approached by a holding bell (3) for the friction stir welding tool and the drive head (2) thereof, b) after the welding device is started up, a welding pin tip (5) is immersed into the plastified material of the two workpieces (6) to be connected, wherein a welding shoe (4) is used which has a trapezoidal structure that extends in the diagonal direction of the welding shoe (4) for receiving the welding pin tip (5), and a circular opening (14) is mounted in a web with a smoothing surface (13) which has a front edge (12) that is part of a stepped Spahn guide stage (11), c) in order to improve the method, a welding shoe (4) is used in which the stepped Spahn guide stage (11) has material conducting channels on the front edge (12).