Self-Adjusting Welding Wire Feed for Stable Weld Pool Contact

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Solution Overview

Problem

Existing welding methods face challenges in maintaining optimal welding wire feed speed, leading to issues such as the wire dipping too deeply or losing contact with the weld pool, resulting in uneven weld seams and defects, especially when welding complex geometries or varying speeds.

Innovation Solution

The method involves tapping the electrical potential produced by the welding current around the electrode to control the welding wire feed speed, ensuring the wire maintains optimal contact with the molten pool by adjusting feed rates based on detected potential changes, preventing excessive immersion or disengagement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a constant wire feed speed is set depending on the set welding current level, then the welding process is simple to operate, but the welding wire dips too deeply into the weld pool or loses contact with the weld pool, resulting in uneven weld seams and defects

Engineering Contradiction:
Improvesimplicity of welding process operationVSAvoiduniformity of weld seam quality
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The patent implements feedback control by detecting the electrical potential between the welding wire and workpiece, then automatically adjusting the wire feed speed based on the detected potential signal. When the wire dips into the pool or loses contact, the potential changes trigger automatic feed speed correction, eliminating the need for manual intervention while maintaining weld quality consistency.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system transitions from static constant wire feed speed to dynamic adaptive wire feed speed. The wire feed mechanism continuously adjusts its speed according to real-time potential detection, allowing the system to adapt to varying welding conditions such as torch position changes, workpiece geometry variations, and pool condition changes.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If the welding torch is guided by hand, then the welding process is flexible for complex geometries, but the distance between the welding torch and the workpiece cannot be maintained exactly, causing wire immersion issues

Engineering Contradiction:
Improveflexibility for complex geometriesVSAvoiddistance control accuracy
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The welding system performs self-correction by using the potential signal as a feedback mechanism. The control system automatically adjusts wire feed speed in response to potential changes caused by distance variations, allowing the system to self-regulate without requiring precise manual distance control while maintaining weld quality.

Inventive Principle:
Principle #25Self-service

3Productivity

If robot-guided welding is used, then welding speed and precision are improved, but wire feed control becomes problematic at varying speeds and complex geometries

Engineering Contradiction:
Improvewelding speed and precisionVSAvoidwire feed control accuracy
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies feedback control specifically to the wire feed mechanism, where the detected potential signal continuously informs adjustments to wire feed speed. This feedback loop operates independently of robot motion control, allowing the wire feed system to adapt to speed variations and geometric complexities while the robot maintains its high-speed, high-precision positioning capabilities.

Inventive Principle:
Principle #23Feedback

4Measurement precision

If heating current is used to detect voltage changes for wire position control, then wire contact detection is possible, but the method only works for hot wire applications and within a narrow parameter range

Engineering Contradiction:
Improvewire position detection capabilityVSAvoidapplicability to different welding types and ranges
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent changes the detection parameter from voltage (used in hot wire methods) to electrical potential, which can be measured in both hot wire and cold wire applications. This parameter change expands the method's applicability across different welding types and operating ranges while maintaining detection precision.

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 automatically sets an optimal mean welding wire feed rate, simplifying the feeding process and adjusting the weld seam filling level, thereby improving weld quality and consistency across various welding conditions.

Implementation Method 1

an arc is maintained between the electrode and a workpiece to be welded by a welding current flowing through the electrode

Methodology Applied
Scientific EffectElectric Arc: Electric Arc

Implementation Method 2

A welding current is passed through the electrode to establish and maintain an arc between the electrode and a workpiece to be welded. The arc melts the workpiece material in a molten pool.

Methodology Applied
Scientific EffectJoule Heating: Joule Heating

Implementation Method 3

the electrical potential produced by the welding current around the electrode is tapped with the welding wire and the welding wire feed speed is controlled using the tapped potential

Methodology Applied
Scientific EffectElectrical Potential: Electric Field

Data Source

PatentEP3852963B1Welding device and method for welding with self-adjusting welding wire feed speed
Publication Date: 2022.04.27 FRONIUS INT GMBH
  • EP3852963B1 patent drawingFigure 1~2
  • EP3852963B1 patent drawingFigure 3~5
  • EP3852963B1 patent drawingFigure 4

AI summary

The aim of the invention is to control the feed of welding wire (8) to the weld (25) in a simple manner in a welding method. This aim is achieved, according to the invention, in that the electric potential (P) arising around the electrode (4) as a result of the welding current (IS) is tapped by means of the welding wire (8), the welding wire advancing speed (vD) is controlled on the basis of the tapped potential (P), and an average welding wire advancing speed (formula (I)) arises as a result of the control.