Welding Waveform Phase Control for Stable Short-Circuit Arc Transfer

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Solution Overview

Problem

Conventional pulsed and short circuit welding regimes face issues such as excessive spatter, suboptimal penetration, and energy inefficiencies, particularly with cored wire electrodes, which affect weld quality and flexibility.

Innovation Solution

The system regulates waveform phases based on preceding short circuit events to control subsequent short circuits, adjusting duration and current levels to achieve stable arc welding with reduced spatter and lower currents, employing a controller to calculate and adjust phases of short circuit and arc events for optimal wire feed speed and current management.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If pulsed welding processes are used to control short circuits between electrode and weld puddle, then weld quality and flexibility improve, but excessive energy is added to the weld causing wire sheath melting and arc flaring

Engineering Contradiction:
Improveweld qualityVSAvoidenergy added to weld
Core Design Contradiction:
Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The system dynamically adjusts welding parameters including pulse frequency, duty cycle, and current levels based on real-time monitoring of wire feed speed, arc voltage, and short circuit detection. This dynamic control allows the system to optimize energy input for each specific welding condition, preventing excessive energy accumulation that causes wire sheath melting while maintaining weld quality.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system incorporates feedback mechanisms that monitor welding parameters and adjust pulse characteristics accordingly. By detecting short circuits and measuring arc voltage, the control system modifies subsequent pulse timing and magnitude to prevent excessive energy input, thereby eliminating wire sheath melting and arc flaring while preserving weld quality improvements.

Inventive Principle:
Principle #23Feedback

2Length of moving object

If high power outputs are generated to clear short circuits, then arc length is maintained at minimum, but wire sheath heating increases causing arc flaring

Engineering Contradiction:
Improvearc lengthVSAvoidwire sheath temperature
Core Design Contradiction:
Length of moving objectVSTemperature

Solution Approach 1:

The system employs periodic pulsed current instead of continuous high power output. By delivering current in controlled pulses with appropriate frequency and duty cycle, the system maintains arc length at minimum while allowing wire sheath cooling between pulses, preventing excessive temperature buildup and arc flaring.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system performs preliminary control of current magnitude and pulse timing before short circuit clearance is needed. By anticipating short circuit conditions and adjusting pulse parameters in advance, the system prepares optimal current levels that clear short circuits effectively without causing wire sheath overheating.

Inventive Principle:
Principle #10Preliminary action

3Speed

If conventional short circuit welding is used, then travel speed is limited, but spatter is excessive requiring cleanup

Engineering Contradiction:
Improvetravel speedVSAvoidspatter
Core Design Contradiction:
SpeedVSObject-generated harmful factors

Solution Approach 1:

The system dynamically adjusts pulse frequency and current magnitude based on travel speed and welding conditions. By optimizing these parameters in real-time, the system enables faster travel speeds while controlling spatter generation through precise current control that prevents excessive molten metal ejection.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes key welding parameters including pulse frequency, duty cycle, and current magnitude to optimize the balance between travel speed and spatter control. By adjusting these parameters according to specific welding applications, the system achieves faster speeds with reduced spatter compared to conventional short circuit welding.

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

This approach enhances weld quality by reducing spatter and improving stability, allowing for faster travel speeds and better penetration while maintaining arc length, thus improving the overall efficiency and responsiveness to dynamic welding variables.

Implementation Method 1

Conventional short circuit gas metal arc welding (GMAW), also referred to as metal inert gas (MIG) welding, is a welding process in which an electric arc forms between an electrode and pieces of metal that are to be welded. The electric arc generates heat that causes the pieces of metal to melt.

Methodology Applied
Scientific EffectElectric arc: Electric Arc

Implementation Method 2

For example, with cored wire electrodes, the electrode may be heated by excessive current added to the wire, particularly insomuch as the weld current tends to flow through the wire sheath

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP3705219B1Systems for controlled arc and short phase time adjustment
Publication Date: 2021.12.15 ILLINOIS TOOL WORKS INC
  • EP3705219B1 patent drawingFigure 1
  • EP3705219B1 patent drawingFigure 2
  • EP3705219B1 patent drawingFigure 3

AI summary

The present application relates to a welding-type system (100), which includes a welding-type power supply (10) configured to generate output power for an arc welding process and a controller (72). The controller (72) calculates a representative duration of a plurality of short circuit events and/or arc events during the arc welding process. Each short circuit event and/or arc event comprises a transitional phase, an intermediate phase, and an end phase. The controller (72) calculates a sum of a duration of the transitional phase, a duration of the intermediate phase, and a duration of a ramp down time from a target current of the intermediate phase to a target current of the end phase associated with a given short circuit or arc event. The controller (72) controls the welding-type power supply (10) to adjust a duration of the transitional phase, the intermediate phase or the ramp down time associated with the given short circuit event such that the sum is within the threshold range of the representative duration. And the controller (72) maintain a duration of the end phase less than a predetermined value.