Arc Welding Current Control for Low-Spatter Wire Reversal

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Solution Overview

Problem

Conventional arc welding methods require constriction detection control to reduce spatter, which is time-consuming, prone to detection line issues, and difficult in large structures, and lacks effectiveness without extra detection lines.

Innovation Solution

An arc welding apparatus that alternates wire feeding between forward and rearward directions while repeating short circuit and arc periods, using a voltage detection circuit to determine periods without extra detection lines, controlling welding current to suppress spatter by maintaining a low current during short circuits.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If constriction detection control is performed to reduce spatter, then welding quality is improved, but detection lines must be provided which increases device complexity and installation time

Engineering Contradiction:
Improvewelding qualityVSAvoiddetection lines
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent extracts the voltage detection function from the arc generation site and relocates it to the welding power supply unit. Only two simple output terminals are needed at the power supply, eliminating the need for complex dedicated detection lines at the torch and base metal interface. This resolves the contradiction by maintaining welding quality control while dramatically simplifying the detection system structure.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The welding power supply unit performs dual functions: it generates the welding current and simultaneously detects the voltage for constriction control. By making the power supply multi-functional, the patent eliminates the need for separate detection lines, thus improving welding quality without increasing device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Manufacturing precision

If dedicated detection lines are provided for constriction detection, then spatter is reduced, but the detection lines may be broken when the welding torch is moved

Engineering Contradiction:
Improvewelding qualityVSAvoiddetection lines
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent removes the vulnerable detection lines from the mobile welding torch and relocates the voltage detection function to the stationary power supply unit. This extraction eliminates the reliability issue of broken detection lines during torch movement while maintaining constriction detection capability for spatter reduction.

Inventive Principle:
Principle #2Taking out (Extraction)

3Manufacturing precision

If constriction detection is performed at the arc generation site, then spatter is reduced, but it is difficult to detect voltage in large structures

Engineering Contradiction:
Improvewelding qualityVSAvoidvoltage detection
Core Design Contradiction:
Manufacturing precisionVSDifficulty of detecting and measuring

Solution Approach 1:

The patent extracts the voltage measurement point from the difficult-to-access arc generation site on large structures and relocates it to the welding power supply unit where voltage can be easily measured at the output terminals. This resolves the detection difficulty while maintaining the ability to control spatter through constriction detection.

Inventive Principle:
Principle #2Taking out (Extraction)

4Productivity

If forward/rearward feeding control is performed to repeat short circuit and arc periods, then welding is achieved, but spatter occurs without proper constriction control

Engineering Contradiction:
Improvewelding processVSAvoidspatter
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent implements feedback control by detecting the voltage at the power supply output and using this information to control the welding current. The detected voltage provides feedback about the droplet constriction state, allowing the system to adjust current to reduce spatter while maintaining the forward/rearward feeding welding process.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent changes the welding current parameter based on detected voltage conditions. By adjusting the current level in response to voltage feedback from the droplet constriction state, the system reduces spatter while maintaining productive welding through alternating short circuit and arc periods.

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

Significantly reduces spatter occurrence without constriction detection control, stabilizes droplet absorption, and maintains arc stability by controlling welding current and feed speed patterns, eliminating the need for dedicated detection lines.

Implementation Method 1

the welding is performed with an arc being generated between a welding wire (consumable electrode) and a base metal

Methodology Applied
Scientific EffectElectric arc: Electric Arc

Data Source

PatentEP4052831B1Arc welding apparatus
Publication Date: 2024.04.17 DAIHEN CORP
  • EP4052831B1 patent drawingFigure 1
  • EP4052831B1 patent drawingFigure 2

AI summary

An arc welding apparatus is configured to perform welding by repeating a short circuit period and an arc period. The welding apparatus is provided with a feeding motor (WM) configured to feed a welding wire (1) by alternately switching between forward feed and rearward feed, and a power controller configured to supply welding voltage (Vw) and welding current (Iw) between the welding wire (1) and a base metal (2). The power controller is configured to cause the instantaneous value of the welding current (Iw) during the short-circuit period to be equal to or less than the average value of the welding current (Iw).