Arc Welding Wire Tip Control via Inverted Feeding Speed

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Solution Overview

Problem

Conventional arc welding methods face challenges in achieving consistent and efficient arc-starting performance, particularly in forming a small globule at the tip of the welding wire, which can be absorbed into the molten metal pool, leading to variations in weld quality and increased welding time.

Innovation Solution

The method involves accelerating the welding wire feeding speed to initiate shorting, retracting the wire backward at a controlled speed to maintain a predetermined distance, and terminating the welding power output after a predetermined duration, ensuring a consistent wire tip shape and preventing absorption into the molten pool.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the wire feeding speed is decelerated at a predetermined inclination toward stop at the end of welding, then the wire tip shape can be controlled to be uniform, but the welding end time becomes too long (100-200msec)

Engineering Contradiction:
Improvewire tip shape uniformityVSAvoidwelding end time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

Instead of decelerating the wire feeding speed toward stop as in conventional methods, the invention accelerates the wire feeding speed at a predetermined inclination toward a predetermined value at the end of welding. This inverted approach quickly forms a uniform wire tip shape and globule, then terminates power output, reducing welding end time to 30-50msec while maintaining shape uniformity.

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

Solution Approach 2:

The invention performs preliminary acceleration of wire feeding speed before power termination to ensure the wire tip achieves the desired uniform shape and globule formation in advance. This preliminary action allows the system to quickly prepare the wire tip configuration needed for good arc-starting performance, then immediately terminate power, avoiding prolonged welding end time.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If a small globule is formed at the wire tip to improve arc-starting performance, then arc-starting performance improves, but the globule may be absorbed into the molten metal pool causing variations in weld quality

Engineering Contradiction:
Improvearc-starting performanceVSAvoidweld quality consistency
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The invention dynamically adjusts wire feeding speed by accelerating at a predetermined inclination toward a predetermined value, creating controlled shorting and globule formation. This dynamic control ensures the globule achieves optimal size and shape for arc-starting performance while maintaining stability through controlled shorting conditions, preventing absorption into the molten pool and ensuring consistent weld quality.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention uses short/arc detection feedback to determine when to terminate power output. The system continuously monitors welding conditions and terminates power at the precise moment when shorting opens during backward retraction, ensuring the wire tip has achieved the desired uniform shape and globule configuration. This feedback control guarantees both excellent arc-starting performance and consistent weld quality.

Inventive Principle:
Principle #23Feedback

3Manufacturing precision

If the welding power output is terminated after integrated welding current reaches a threshold value, then the wire tip shape can be controlled, but the process complexity increases

Engineering Contradiction:
Improvewire tip shape controlVSAvoidcontrol process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The invention changes the wire feeding speed parameter by accelerating at a predetermined inclination toward a predetermined value, replacing complex integrated current threshold control. This parameter change simplifies the control process while achieving the same wire tip shape control objective, reducing system complexity while maintaining manufacturing 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 allows for the formation of a uniform wire tip shape without variations, improving arc-starting performance and significantly reducing the welding end time from 100msec to 200msec to 30msec to 50msec, thereby enhancing productivity and weld quality.

Implementation Method 1

generating arc between a welding wire serving as a consumable electrode and a base metal as an object to be welded

Methodology Applied
Scientific EffectArc: Electric Arc

Implementation Method 2

supplying a predetermined amount of welding current for a predetermined duration of welding time

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP2402105B1Arc welding method and arc welding device
Publication Date: 2016.02.10 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP2402105B1 patent drawingFigure 1
  • EP2402105B1 patent drawingFigure 2
  • EP2402105B1 patent drawingFigure 3~4

AI summary

An arc welding method comprising the steps of accelerating a feeding speed of a welding wire to cause shorting between the welding wire and a base metal when a welding end signal is input during a period of arcing, retracting the welding wire backward thereafter until a wire retracting speed reaches a predetermined rate, controlling the wire retracting speed constant at this speed for a predetermined duration of time, then stopping the backward retraction of the welding wire, and then terminating a welding power output after supplying a predetermined amount of welding current for a predetermined duration of time starting from a time when opening of the shorting occurs during the backward retraction of the welding wire.