Welding Power Source Modulation for Consistent Bead Appearance

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Solution Overview

Problem

Conventional arc welding systems rely heavily on operator skill and experience to achieve a desired weld bead appearance, such as a stacked dime appearance, which is challenging to consistently produce and requires significant training, especially in applications like MIG welding of aluminum.

Innovation Solution

The modulation of one or more welding parameters, including electrode negative and positive portions of the welding output current, wire feed speed, and switching between different welding processes, is used to achieve a specified weld bead appearance. This is achieved through a system comprising a switching power supply, waveform generator, and controller that generate cyclical welding currents and adjust parameters based on modulation frequency and travel speed to affect the weld bead appearance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional arc welding systems are used with limited techniques, then the system complexity remains low, but the manufacturing precision of weld bead appearance deteriorates

Engineering Contradiction:
Improveweld bead appearance consistencyVSAvoidwelding system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies periodic action by modulating welding parameters (current amplitude, wire feed speed, travel speed) at specific frequencies during the welding process. This periodic modulation creates consistent weld bead appearances through controlled oscillations in parameter values, transforming the continuous welding process into a periodically controlled process that achieves precision through repetition and consistency.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent implements parameter changes by systematically varying multiple welding parameters including current amplitude, wire feed speed, and travel speed. These parameter changes are coordinated and modulated together to achieve the desired weld bead appearance, demonstrating how changing multiple parameters in concert can resolve the contradiction between precision and complexity.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If operator skill and experience are increased to achieve desired weld bead appearance, then the manufacturing precision improves, but the ease of operation deteriorates

Engineering Contradiction:
Improveweld bead appearance consistencyVSAvoidoperator skill requirement
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The patent applies self-service by implementing automated control systems that independently manage welding parameters without requiring operator intervention. The system automatically modulates current amplitude, wire feed speed, and travel speed based on pre-programmed sequences, enabling the welding process to self-regulate and achieve consistent results without relying on operator skill or experience.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent incorporates feedback mechanisms where the welding system monitors and adjusts parameters in real-time based on process conditions. This feedback control enables the system to automatically compensate for variations and maintain consistent weld bead appearance, reducing the need for skilled operators to manually adjust parameters during welding.

Inventive Principle:
Principle #23Feedback

3Manufacturing precision

If multiple welding parameters are modulated synergistically, then the manufacturing precision of weld bead appearance improves, but the device complexity increases

Engineering Contradiction:
Improveweld bead appearance controlVSAvoidparameter modulation system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies merging by combining multiple welding parameter control functions into a single integrated system. The current amplitude modulation, wire feed speed modulation, and travel speed modulation are merged into one coordinated control architecture that manages all parameters simultaneously, reducing the overall system complexity compared to having separate independent control systems for each parameter.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent implements universality by designing a multi-functional control system that can modulate multiple welding parameters (current, wire feed speed, travel speed) using a single control architecture. This universal system performs multiple functions through integrated control, avoiding the need for separate specialized control systems for each parameter and thereby managing complexity while achieving precision.

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

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

The modulation of welding parameters allows for consistent production of desired weld bead appearances, such as a stacked dime appearance, with improved metallurgical characteristics like reduced porosity and grain structure, reducing the need for extensive operator training and expertise.

Implementation Method 1

An arc welding power source for generating an arc between a consumable welding electrode and a welding workpiece is provided

Methodology Applied
Scientific EffectElectric arc: Electric Arc

Data Source

PatentEP2908975B8System and power source providing modulation schemes for achieving a consistent weld bead appearance
Publication Date: 2017.07.26 LINCOLN GLOBAL INC

AI summary

Systems and methods for affecting an appearance of a deposited weld bead by modulating one or more welding parameters. For example, an electrode negative portion of a welding output current may be modulated to affect the appearance of a deposited weld bead. Furthermore, a wire feed speed of a welding electrode (E) may be synergistically modulated with an electrode negative portion of a welding output current to affect a deposited weld bead appearance. Two or more welding processes may be interleaved with each other at a specified modulation frequency to affect a deposited weld bead appearance. One or more welding parameters may be modulated based on a welding travel speed to provide a consistent appearance of a deposited weld bead. The invention refers also to an arc welding power source comprising: a switching power supply (105); a waveform generator (120); and a controller (130).