Plasma Gas Cleaning for Consistent Stud Joining on Coated Surfaces

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing joining methods, such as stud welding and stud gluing, face challenges with inconsistent joints due to irregular surface coatings and material properties, particularly with aluminum alloys, leading to issues with conductivity and porosity, which affect the quality and strength of the weld.

Innovation Solution

A joining device that uses a plasma arc to evaporate surface coatings without accumulation, employing a plasma gas nozzle with a conical plasma arc and gas pressure to ensure directional stability and effective cleaning, allowing for consistent joint formation without melting the surface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If an arc cleaning process is used before stud welding, then impurities are ionized and detached from the component surface, but impurities accumulate on the joining surface of the stud

Engineering Contradiction:
Improvesurface impuritiesVSAvoidjoint consistency
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

A plasma gas jet is introduced as an intermediary medium between the arc source and the joining surfaces. The plasma gas flows through a nozzle and directs the arc's energy toward the component surface while preventing impurity accumulation on the stud surface, thus mediating the cleaning process to achieve selective surface preparation

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The plasma arc cleaning process is made directional through the nozzle geometry, creating different cleaning effects on different surfaces. The component surface receives intensive cleaning while the stud surface is protected from impurity accumulation, achieving local quality differentiation in the cleaning action

Inventive Principle:
Principle #3Local quality

2Object-affected harmful factors

If surface coatings are removed by plasma arc, then surface purity is improved, but surface melting may occur

Engineering Contradiction:
Improvesurface coatingsVSAvoidsurface integrity
Core Design Contradiction:
Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The plasma arc cleaning is applied with controlled energy input that is sufficient to remove surface coatings and impurities but deliberately limited to avoid excessive heating that would cause melting. The process uses partial action - enough cleaning to achieve purity without crossing into damaging territory

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

Plasma gas flow is used to carry the arc energy and control the heating distribution. The gas flow dynamics help distribute the thermal energy evenly and prevent localized overheating that could lead to surface melting, using fluid dynamics to control thermal effects

Inventive Principle:
Principle #29Pneumatics and hydraulics

3Stability of the object's composition

If gas pressure is applied to stabilize plasma arc direction, then arc stability is improved, but energy consumption increases

Engineering Contradiction:
Improvearc directional stabilityVSAvoidplasma gas energy
Core Design Contradiction:
Stability of the object's compositionVSUse of energy by moving object

Solution Approach 1:

The mechanical system of high gas pressure is replaced with a plasma-based system where the arc itself generates the necessary flow dynamics. The plasma arc's own energy sustains the gas flow and directional stability without requiring external high-pressure gas supplies, substituting mechanical pressure with plasma kinetic energy

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

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 achieves high-quality, consistent joints by effectively removing surface impurities and coatings, maintaining surface integrity, and ensuring stable arc formation even with low electric currents, thereby enhancing the strength and reliability of the weld.

Implementation Method 1

the plasma or the plasma arc which is directed onto the joining surface causes any surface coatings on the joining surface to evaporate without these materials subsequently accumulating on the joining surface of the joining element

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 2

the plasma or the plasma arc which is directed onto the joining surface causes any surface coatings on the joining surface to evaporate

Methodology Applied
Scientific EffectGas pressure: Pressure Increase

Implementation Method 3

an arc is created between the joining element and component with alternating polarity before the welding process, causing impurities to be ionized and detached from the component surface

Methodology Applied
Scientific EffectPlasma: Plasma

Implementation Method 4

causing impurities to be ionized and detached from the component surface

Methodology Applied
Scientific EffectIonization: Ionisation

Data Source

PatentEP3988234B1Device for joining elements to components with a plasma gas cleaning device
Publication Date: 2023.10.18 NEWFREY LLC
  • EP3988234B1 patent drawingFigure 1~3
  • EP3988234B1 patent drawingFigure 4~7
  • EP3988234B1 patent drawingFigure 8a~8c

AI summary

The present application relates to a joining device for joining a joining element (24) to a component (28), with: a joining head (12), which comprises a retaining device (22) for a joining element (24) and by means of which the joining element (24) can be moved along a joining axis (20) in relation to a component (28), and a cleaning device (34) to carry out a cleaning process on a joining surface (26; 30) of the component (28) and/or on a joining surface (26) of the joining element (24), wherein the cleaning device (34) comprises a plasma gas cleaning device.