Arc Welding Current Timing for Low-Spatter Wire Feed Reversal

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In consumable electrode type arc welding, it is challenging to optimize the timing of switching the welding current to a small current value in the latter half of the arc period to minimize spatter generation, as predicting short circuits is difficult and incorrect timing can lead to unstable arcs or increased spatter.

Innovation Solution

An arc welding control method that alternately switches the welding wire's feeding rate between forward- and reverse-feeding periods, switches the welding current to a small value in the latter half of the arc period, and adjusts this timing based on average feeding rate and voltage setting values, using error amplification and reference voltage settings to optimize the switching time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the welding current is switched to a small current value after a predetermined time has elapsed from the reoccurrence of the arc, then the arc state remains stable, but the welding current switching timing may be too late to reduce spatter generation

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

Solution Approach 1:

The patent uses feedback control by detecting the actual arc period duration and using it to dynamically adjust the welding current switching timing. The control system measures the arc period and calculates the optimal switching point within the latter half of the arc period, creating a closed-loop system that adapts to varying welding conditions while maintaining both arc stability and spatter reduction.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent transitions from a fixed predetermined time delay to a dynamic switching mechanism that adapts to the actual arc period. By making the current switching timing dependent on the detected arc period characteristics, the system can optimize the switching moment for each specific welding condition, balancing arc stability with spatter prevention.

Inventive Principle:
Principle #15Dynamics

2Object-generated harmful factors

If the welding current is switched to a small current value immediately, then spatter generation is reduced, but the arc state becomes unstable

Engineering Contradiction:
Improvespatter generationVSAvoidarc state stability
Core Design Contradiction:
Object-generated harmful factorsVSReliability

Solution Approach 1:

The patent prepares for current switching by monitoring arc period characteristics in advance and calculating the optimal switching timing before the actual switch occurs. This preliminary analysis of the arc state allows the system to plan the current reduction timing to occur at the optimal moment in the latter half of the arc period, preventing both spatter and instability.

Inventive Principle:
Principle #10Preliminary action

3Manufacturing precision

If forward and reverse feeding control is implemented to stabilize the short circuit and arc period repetition, then welding quality improves, but the complexity of controlling the welding current timing increases

Engineering Contradiction:
Improvewelding qualityVSAvoidcontrol system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent combines the forward-reverse feeding control with the welding current timing control into an integrated system. By merging these control functions and using the arc period detection from the feeding control as the basis for current switching timing, the system achieves coordinated optimization of both wire feeding and current control without requiring entirely separate control mechanisms.

Inventive Principle:
Principle #5Merging (Combining)

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 method effectively reduces spatter generation by stabilizing the arc state and ensuring the welding current is reduced before a short circuit occurs, improving welding quality.

Implementation Method 1

generating an arc between the welding wire and a base metal

Methodology Applied
Scientific EffectElectric arc: Electric Arc

Data Source

PatentEP3495084B1Arc welding control method
Publication Date: 2021.03.31 DAIHEN CORP
  • EP3495084B1 patent drawingFigure 1
  • EP3495084B1 patent drawingFigure 2(A)~2(E)
  • EP3495084B1 patent drawingFigure 3

AI summary

The purpose of the present invention is to reduce the amount of sputtering in a welding method wherein a welding wire feed rate is alternately switched between a forward feed period and a reverse feed period. Provided is an arc welding control method that switches a feed rate Fw for welding wire alternately between a forward feed period and a reverse feed period, repeats a short period and an arc period, and electrifies with a welding current Iw switched to a small current value in the latter half of the arc period, wherein a basic voltage setting value is set according to an average feed rate setting value, the error amplitude value for a voltage setting value and the basic voltage setting value is calculated, and the timing (current reduction time Td) for switching the welding current Iw to the small current value is varied on the basis of the average feed rate setting value and the error amplitude value.