Friction Stir Welding Butt Joint Alignment via Toggle Lever Deformation

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Solution Overview

Problem

Existing methods for friction stir welding of rotationally symmetrical hollow bodies, such as flange-pipe-flange connections, face challenges with deviations in roundness and straightness, leading to quality issues and increased production time due to complex setups and maintenance-intensive equipment.

Innovation Solution

A method and system that utilize a centering, internal shaping, and clamping disk with toggle-lever-like power amplification to deform and maintain the joint area, ensuring precise alignment and contact pressure for friction stir welding, allowing for the production of high-quality butt joints with reduced setup time and material savings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional friction stir welding equipment is used for rotationally symmetrical hollow bodies, then welding can be performed, but deviations in roundness and straightness occur leading to quality issues

Engineering Contradiction:
Improvejoint qualityVSAvoidsetup complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The method performs preliminary centering and alignment of the rotationally symmetrical bodies before the welding process begins. The bodies are centered on a common axis and aligned in the longitudinal direction prior to applying contact pressure and performing friction stir welding, ensuring that roundness and straightness deviations are corrected in advance.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention replaces complex mechanical alignment and support devices with a controlled process involving centralized rotational positioning and axial clamping. Instead of using multiple supporting devices to maintain alignment, the system rotates the bodies on a common axis and applies controlled contact pressure to maintain alignment during welding.

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

2Productivity

If conventional friction stir welding equipment is used, then welding can be performed, but production time increases due to complex setups and maintenance

Engineering Contradiction:
Improveproduction timeVSAvoidequipment complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The method performs preliminary centering and alignment of the rotationally symmetrical bodies before the welding process begins. The bodies are centered on a common axis and aligned in the longitudinal direction prior to applying contact pressure and performing friction stir welding, ensuring that roundness and straightness deviations are corrected in advance.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention controls and optimizes process parameters including rotational speed, contact pressure, and feed rate to improve welding efficiency. By centrally controlling these parameters and maintaining optimal values throughout the process, the method reduces production time while ensuring consistent joint quality.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If conventional welding equipment is used, then welding can be performed, but alignment precision and contact pressure control are insufficient

Engineering Contradiction:
Improvealignment precisionVSAvoidprocess simplicity
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The invention replaces complex mechanical alignment and support devices with a controlled process involving centralized rotational positioning and axial clamping. Instead of using multiple supporting devices to maintain alignment, the system rotates the bodies on a common axis and applies controlled contact pressure to maintain alignment during welding.

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

Solution Approach 2:

The invention controls and optimizes process parameters including rotational speed, contact pressure, and feed rate to improve welding efficiency. By centrally controlling these parameters and maintaining optimal values throughout the process, the method reduces production time while ensuring consistent joint quality.

Inventive Principle:
Principle #35Parameter changes

4Manufacturing precision

If conventional friction stir welding is used on rotating bodies, then welding can be performed, but the position and shape of the butt joint directly influence contact forces requiring precise preparation

Engineering Contradiction:
Improvebutt joint qualityVSAvoidpreparation complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The method performs preliminary centering and alignment of the rotationally symmetrical bodies before the welding process begins. The bodies are centered on a common axis and aligned in the longitudinal direction prior to applying contact pressure and performing friction stir welding, ensuring that roundness and straightness deviations are corrected in advance.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention controls and optimizes process parameters including rotational speed, contact pressure, and feed rate to improve welding efficiency. By centrally controlling these parameters and maintaining optimal values throughout the process, the method reduces production time while ensuring consistent joint quality.

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 effectively eliminates deviations in roundness and straightness, improving the quality of friction stir welded joints, reducing production time, and saving material by maintaining precise alignment and contact pressure during the welding process.

Implementation Method 1

a rotating shaft that can be lowered onto each butt joint with contact pressure with a rotating pin of a friction stir welding tool that can be advanced or retracted in relation to the shaft into or out of the butt joint and that can be advanced in the x, y and z direction the material areas of the joint softens, stirs and connects with each other within one revolution

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2747932B1Method and system for the creation of a butt joint between rotationally symmetrical members using frictionstir welding with locally forming of the butt region of the members
Publication Date: 2016.06.08 WARTMANN TECH
  • EP2747932B1 patent drawingFigure 1
  • EP2747932B1 patent drawingFigure 2
  • EP2747932B1 patent drawingFigure 3a~3b

AI summary

The invention relates to a method and a system for creating a butt joint between rotationally symmetrical members (2, 3), e.g. flange-pipe-flange, flange-pipe or pipe arrangements, using friction stir welding. The aim of the invention is to improve the butt joint of friction stir welded rotationally symmetrical members (2, 3) in such a way that differences in the out-of-roundness and straightness in the butt region of the rotationally symmetrical members (2, 3) are eliminated, measurement and set-up processes can be dispensed with, the quality is improved, production times are reduced, and less material is required. Said aim is achieved in that following the centering process, the butt region of the members (2, 3) that are retained using axial clamping forces is locally deformed by radially pressing the members to obtain the inner shape thereof and straightening the members using a centering, inner-shape-forming, straightening and clamping disk, the centering force being boosted in the manner of a toggle lever to an inner-shape-forming force causing the local deformation, and said inner-shape-forming force being maintained in the butt region of the members (2, 3) until the end of the friction stir welding process.