Plasma Torch Electrode Pressure Equalization

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Solution Overview

Problem

The existing electrode structures for plasma cutting torches face issues with maintaining safety and operational reliability due to air-filled cavities that can lead to overpressure, loosening of joints, and potential hazards during prolonged operation, as well as corrosion and cavitation from moisture, which affect thermal and electrical conductivity.

Innovation Solution

The electrode structure incorporates pressure equalization channels between the cavity and the environment, allowing for gradual release of air during assembly and maintaining contact for thermal and electrical conductivity, with features like grooves, flattenings, and inclined channels to ensure effective pressure equalization and secure connections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If emission inserts are inserted into bores or recesses and fastened by cohesive soldered or welded connection, force-fitting by means of a press fit or form-fitting, then good thermal and electrical conductivity is achieved, but air-filled cavities are formed that can lead to overpressure and joint loosening

Engineering Contradiction:
Improvejoint stabilityVSAvoidoverpressure in cavity
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention extracts the harmful air-filled cavity from the system by creating pressure equalization channels that allow the cavity to communicate with the environment. This enables pressure equalization between the cavity and ambient pressure, preventing overpressure buildup that would otherwise cause joint loosening and reliability issues.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The pressure equalization channel acts as an intermediary pathway between the sealed cavity and the environment. This channel mediates the pressure differential by allowing controlled pressure equalization, thus protecting the joint connection from harmful overpressure while maintaining the sealed cavity structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If precise joint connections are made with narrow tolerances to ensure good thermal conduction, then thermal and electrical conductivity is improved, but the joint becomes susceptible to loosening due to pressure increases from air expansion during operation

Engineering Contradiction:
Improvethermal and electrical conductivityVSAvoidjoint connection stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The harmful effect of pressure buildup is extracted from the system through pressure equalization channels. These channels allow the air-filled cavity to communicate with the environment, enabling pressure equalization that prevents joint loosening while preserving the precise joint connections needed for good thermal and electrical conductivity.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention converts the potentially harmful air-filled cavity into a beneficial pressure-equalizing feature. By providing pressure equalization channels, the cavity's air content becomes useful for pressure balancing rather than harmful, thus protecting the precise joint connections from loosening during operational temperature increases.

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

3Productivity

If emission inserts protrude from the electrode holder to form tip electrodes for non-oxygen gases, then cutting performance with argon, hydrogen, or nitrogen is improved, but the structure becomes more complex with additional holding elements

Engineering Contradiction:
Improvecutting performanceVSAvoidelectrode structure
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The electrode structure is designed with multi-functionality to handle both flat electrode configurations for oxygen-containing gases and tip electrode configurations for non-oxygen gases. The emission insert can be positioned either flush with or protruding from the electrode holder, and the pressure equalization channel design accommodates both configurations, reducing the need for completely separate electrode structures for different gas types.

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

This design enhances the safety and reliability of the electrode structure by preventing joint loosening and corrosion, maintaining effective thermal and electrical conductivity over extended operation, and ensuring secure connections.

Implementation Method 1

Between a cavity formed in a recess or bore and the emission insert and the environment, there is at least one pressure equalization channel through the emission insert and/or between an outer lateral surface area of the emission insert and the inner wall of the recess or bore formed in the holding element or the electrode holder

Methodology Applied
Scientific EffectPressure equalization: Pressure Gradient

Implementation Method 2

It is important for the connection that it can be maintained permanently during operation, while maintaining a good and as homogeneous as possible thermally and electrically conductive connection

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

It is important for the connection that it can be maintained permanently during operation, while maintaining a good and as homogeneous as possible thermally and electrically conductive connection

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 4

Different gases, e.g. B. the monoatomic argon and / or the diatomic gases hydrogen, nitrogen, oxygen or air are used. These gases ionize and dissociate with the energy of the plasma arc.

Methodology Applied
Scientific EffectIonization: Ionisation

Implementation Method 5

Plasma is a thermally highly heated, electrically conductive gas that consists of positive and negative ions, electrons, and excited and neutral atoms and molecules.

Methodology Applied
Scientific EffectPlasma: Plasma

Data Source

PatentEP2849542B1Electrode structure for plasma cutting torches
Publication Date: 2018.08.22 KJELLBERG STIFTUNG
  • EP2849542B1 patent drawingFigure 1
  • EP2849542B1 patent drawingFigure 2.1~2.2
  • EP2849542B1 patent drawingFigure 2.3~2.4

AI summary

The invention relates to an electrode assembly for plasma cutting torches, in which a recess or bore, open on one side towards the workpiece to be processed, is formed in an electrode holder or a retaining element to accommodate an emission insert, in which the inserted emission insert can be fixed by force, form, and/or material bonding. At least one pressure equalization channel and/or at least a pressure equalization channel, effective at least temporarily, through the emission insert and/or between an outer surface area of ​​the emission insert and the inner wall of the recess or bore formed in the retaining element or the electrode holder (7.1) is provided between a cavity formed in a recess or bore and the emission insert and the surroundings.On its own or additionally, at least one pressure equalization channel and/or a temporarily effective pressure equalization channel may also be present between a cavity formed in a recess or bore and the retaining element and the environment through the retaining element and/or between an outer surface area of ​​the retaining element and the inner wall of the recess or bore formed in the electrode element or the retaining element.