TIG Welding Controller Waveform Selection for Arc Stability

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Solution Overview

Problem

TIG welding systems face challenges in consistently initiating and controlling the arc due to the numerous variables involved, making it difficult for users to tune the current, voltage, and other parameters effectively, especially in orbital welding applications with limited visibility.

Innovation Solution

A TIG welding system with a controller that selects pre-programmed waveforms based on user-selected amperage, preventing user control during the arc initiation stage and allowing control only after a steady state is achieved, simplifying the setup process and ensuring stable arc initiation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple parameters (current, voltage, frequency, pulse ratio) are made adjustable for arc initiation, then the system becomes more adaptable to different welding conditions, but the complexity of parameter tuning increases significantly

Engineering Contradiction:
Improveadaptability to different welding conditionsVSAvoidcomplexity of parameter tuning
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The controller stores multiple pre-configured waveforms in memory, each optimized for specific welding conditions. The system performs preliminary setup of all arc initiation parameters (current amplitude, voltage, frequency, pulse ratio) before the welding operation begins, allowing users to simply select from pre-optimized waveforms rather than tuning multiple parameters during operation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system automatically changes multiple parameters simultaneously based on the selected waveform and detected electrode diameter. When a user selects a waveform and inputs electrode diameter, the controller automatically adjusts current amplitude, voltage, frequency, and pulse ratio according to pre-programmed relationships, eliminating the need for manual tuning of each parameter.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If the system allows user control during arc initiation, then operational flexibility is improved, but arc stability and consistency deteriorate due to improper parameter settings

Engineering Contradiction:
Improveoperational flexibilityVSAvoidarc stability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The controller automatically controls all arc initiation parameters based on pre-stored waveforms before the user can interfere. During the arc initiation stage, the system executes pre-programmed sequences with automatically adjusted parameters, ensuring stable arc establishment before transferring control to the user.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system dynamically transfers control from automatic to manual mode. During arc initiation, the controller maintains automatic control to ensure stability, then automatically transitions to user control once the arc is established and parameters are optimized, providing both stability and operational flexibility at appropriate times.

Inventive Principle:
Principle #15Dynamics

3Manufacturing precision

If the system automatically selects waveforms based on amperage, then arc initiation consistency is improved, but user control over the welding process is reduced

Engineering Contradiction:
Improvearc initiation consistencyVSAvoiduser control
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The controller automatically selects and configures waveforms based on user input of amperage and electrode diameter before welding begins. This preliminary automatic configuration ensures consistent arc initiation parameters while still allowing users to select from multiple pre-programmed waveforms designed for different welding conditions and geometries.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system dynamically adjusts the balance between automatic and manual control. During arc initiation, automatic control ensures consistency, but users retain the ability to select from multiple waveforms and adjust parameters during the sequencing stage, providing both consistency and user control at appropriate phases of the welding process.

Inventive Principle:
Principle #15Dynamics

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 solution simplifies the arc initiation process by automating parameter adjustments, reducing user error and ensuring consistent arc establishment, thereby improving welding quality and efficiency, especially in complex geometries like orbital welding.

Implementation Method 1

the controller is programmed to select one of the at least one waveform based on the user-selected amperage and apply power from the power source to the electrode according to the selected at least one waveform

Methodology Applied
Scientific EffectElectrical Energy Transformation:

Implementation Method 2

TIG welding employs a tungsten electrode... A key stage in TIG welding is the initiation of the arc

Methodology Applied
Scientific EffectElectric Arc: Electric Arc

Data Source

PatentEP2991795B1TIG welding system
Publication Date: 2016.11.09 LINCOLN GLOBAL INC
  • EP2991795B1 patent drawingFigure 1
  • EP2991795B1 patent drawingFigure 2
  • EP2991795B1 patent drawingFigure 3

AI summary

A TIG welding system is provided including a power source having a controller in communication therewith, the controller having a memory storing at least one waveform; a welding torch including an electrode electrically connected to the controller, the electrode having a length and a diameter; an amperage input in communication with the controller and adapted to receive a user-selected welding amperage; wherein in the controller is programmed to select one of the at least one waveform based on the user-selected amperage and apply power from the power source to the electrode according to the selected at least one waveform; wherein the at least one waveform includes an arc initiation stage including at least one pulse, wherein during the arc initiation stage, the controller is configured to prevent user control of an arc current or voltage, wherein upon attaining a steady state at the user-selected welding amperage, the controller is configured to permit user control of the arc current or voltage applied to the electrode.