Arc Welding Wire Feed Reversal for Low-Spatter Arc Start

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Solution Overview

Problem

Conventional arc welding methods generate excessive spatters at the start of the arc, which adhere to the base material, reducing productivity and product value, as they rely on pulse control that is ineffective in managing the electromagnetic pinch force.

Innovation Solution

The method involves periodically alternating the wire feed speed between forward and reverse feeding with predetermined frequency and amplitude at the start of welding, forcing the short-circuit open regardless of the electromagnetic pinch force, and then transitioning to a constant speed to control the welding output.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If pulse control is used at the start of arc welding to form a molten pool, then the arc stabilization time is reduced, but excessive spatters are generated due to ineffective management of electromagnetic pinch force

Engineering Contradiction:
Improvearc stabilizationVSAvoidspatter generation
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The wire feed speed is controlled to periodically alternate between forward feeding and reverse feeding at a predetermined frequency during the arc start phase. This periodic action creates controlled short-circuiting and arc formation cycles that prevent excessive spatter generation while ensuring stable molten pool formation, resolving the contradiction between arc stabilization and spatter reduction

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The wire feed speed is dynamically adjusted between forward and reverse directions during the arc start phase, then transitions to constant speed after molten pool formation. This dynamic control allows the system to manage electromagnetic pinch force effectively during the critical start phase while maintaining stable welding conditions afterward, reducing spatters without compromising arc stabilization

Inventive Principle:
Principle #15Dynamics

2Productivity

If the wire feed speed is constantly increased to improve welding speed, then productivity is improved, but spatter adhesion to the base material increases

Engineering Contradiction:
Improvewelding speedVSAvoidspatter adhesion
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

By implementing periodic forward and reverse wire feeding during the arc start phase, the system controls the formation and detachment of molten metal droplets. This prevents excessive spatter generation that would otherwise occur at high welding speeds, allowing high productivity to be maintained without increased spatter adhesion to the base material

Inventive Principle:
Principle #19Periodic action

3Manufacturing precision

If pulse control is applied to separate and shift droplets, then molten pool formation is accelerated, but the electromagnetic pinch force causes excessive spatter

Engineering Contradiction:
Improvemolten pool formation precisionVSAvoidspatter from electromagnetic pinch force
Core Design Contradiction:
Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

Instead of using pulse control that applies electromagnetic pinch force to separate droplets (which causes spatter), the invention inverts the approach by using reverse wire feeding to physically pull the wire away from the base material. This alternative mechanism achieves droplet separation and molten pool formation without relying on electromagnetic pinch force, thereby preventing spatter generation while maintaining manufacturing precision

Inventive Principle:
Principle #13The other way round (Inversion)

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 significantly reduces the generation and adhesion of spatters, improving welding productivity by ensuring a stable arc formation and minimizing spatter formation during the transition from short-circuit to arc states.

Implementation Method 1

generating an arc between a welding wire as a consumable electrode and a material to be welded

Methodology Applied
Scientific EffectArc: Electric Arc

Implementation Method 2

with which a molten pool is formed by separation and shift, and, after the pulse wave-like electric current is supplied, pulse control is changed from pulse control to short-circuit control

Methodology Applied
Scientific EffectElectromagnetic pinch force: Lorentz Force

Data Source

PatentEP2338628B2Arc welding control method and arc welding device
Publication Date: 2023.02.15 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP2338628B2 patent drawingFigure 1
  • EP2338628B2 patent drawingFigure 2
  • EP2338628B2 patent drawingFigure 3

AI summary

An arc welding control method for carrying out welding by generating an arc between a wire and a base material. The wire is fed at wire feed speed (Wf) of periodically repeating forward feeding and reverse feeding with predetermined frequency and amplitude from time point (100) at which start of the welding is instructed, or from a certain time point (141) after the start of the welding is instructed, and then the wire feed speed is changed to a constant speed. Since the wire feed speed is controlled by periodically repeating forward feeding and reverse feeding at the arc start, short-circuit can be opened regardless of the electromagnetic pinch force, and spatters, which are generated at the early stage of the arc start because a molten pool is not preset, can be reduced.