Friction Stir Welding Tool Housing With Discharge Hole

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Solution Overview

Problem

Friction stir welding tools face excessive heat and degradation due to material accumulation between the pin and shoulder, leading to shortened service life, as excess material from workpieces contacts the rotating pin during continuous welding, causing frictional heat and potential damage.

Innovation Solution

Incorporating a housing with a discharge hole connected to the outside, which allows excess material to be continuously discharged, preventing excessive frictional heating and material accumulation, thus minimizing pin degradation and extending tool life.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the pin and shoulder are separate from each other in friction stir welding tool, then the welding process can be implemented without melting the workpieces, but material pieces may be left in the space between the pin and the shoulder causing excessive frictional heat and pin degradation

Engineering Contradiction:
Improvepin strength maintenanceVSAvoidfrictional heat from material accumulation
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention extracts and removes the harmful material accumulation from the system by providing a discharge hole that allows material pieces to be ejected from the housing. This prevents the material pieces from remaining in the space between the pin and shoulder, thereby eliminating the source of excessive frictional heat and pin degradation.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention converts the potentially harmful material accumulation into a beneficial dischargeable flow by designing the housing with a discharge hole. The material pieces that would otherwise cause harm are instead channeled through the discharge hole, transforming them from a harmful factor into a controlled ejection process that prevents damage to the pin.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

2Productivity

If continuous welding is performed with separate pin and shoulder, then productivity is improved, but material accumulation between pin and shoulder causes pin damage and shortens service life

Engineering Contradiction:
Improvecontinuous welding capabilityVSAvoidtool service life
Core Design Contradiction:
ProductivityVSDuration of action of stationary object

Solution Approach 1:

The discharge hole extracts material pieces from the housing interior, preventing accumulation that would otherwise occur during continuous welding operations. This allows continuous welding to proceed without the detrimental effects of material buildup, maintaining both high productivity and extended tool service life.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention implements a discarding mechanism where material pieces are continuously removed through the discharge hole during the welding process. This prevents the accumulation of material that would lead to pin damage, thereby enabling continuous welding operations to maintain both high productivity and extended tool lifespan.

Inventive Principle:
Principle #34Discarding and recovering

3Reliability

If material pieces are discharged through the discharge hole, then pin degradation is prevented, but the housing structure becomes more complex

Engineering Contradiction:
Improvepin protection from excessive heatVSAvoidhousing structure with discharge hole
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The housing is segmented by introducing a discharge hole that divides the housing interior into regions that facilitate material flow toward the discharge opening. This segmentation allows material pieces to be directed and removed efficiently, providing pin protection while adding minimal structural complexity.

Inventive Principle:
Principle #1Segmentation

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 discharge hole configuration effectively prevents excessive heat and material accumulation, reducing pin degradation and extending the service life of the friction stir welding tool by efficiently removing excess material during continuous welding processes.

Implementation Method 1

the pin is inserted into the workpieces, causing frictional heat between the rotating tool and the workpieces

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

The frictional heat causes a plastic flow of the workpieces, causing the workpieces to be welded together

Methodology Applied
Scientific EffectPlastic flow: Plasticity

Implementation Method 3

a workpiece entering the space between the stir pin and the housing hole of the housing is discharged through the discharge hole

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP3616826B1Tool for friction stir welding and device for friction stir welding
Publication Date: 2022.01.12 YAMAZAKI MAZAK KK
  • EP3616826B1 patent drawingFigure 1
  • EP3616826B1 patent drawingFigure 2A~2C
  • EP3616826B1 patent drawingFigure 3

AI summary

The present invention provides a friction stir welding tool and a friction stir welder to which the friction stir welding tool is applied. The friction stir welding tool according to the present invention includes a stir pin and a housing. The stir pin includes a rotation axis. The housing includes a first surface. The housing contains the stir pin rotatably about the rotation axis relative to the housing. The housing includes a housing hole opening on the first surface. The stir pin includes a stir portion that is located at one end of the rotation axis, that is contained in the housing hole with a part of the stir portion protruding through and beyond the first surface, and that is to be inserted into a workpiece. The housing includes a discharge hole through which the housing hole is connected to an outside of the housing.