Polyphase Arc Wire Preheating for Higher Deposition Welding

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Solution Overview

Problem

Conventional welding systems face inefficiencies in preheating welding wire, leading to low deposition rates and excess energy transfer to the workpiece, causing distortion and oxidation, especially in aluminum welding due to surface oxide layers and organic contaminants.

Innovation Solution

The use of an electric arc preheating system with multiple tungsten electrodes connected to a polyphase power source to preheat welding wire, reducing current requirements, maintaining efficiency across metals, and effectively removing oxide layers and contaminants through stable arcs and alternating current.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional preheating methods are used, then wire preheating is achieved, but deposition rates remain low and energy transfer to workpiece is excessive

Engineering Contradiction:
Improvedeposition rateVSAvoidenergy transfer to workpiece
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The patent applies preliminary action by preheating the welding wire before it reaches the weld zone using electric arc heating between contact tips. This preheating action occurs in advance, reducing the thermal load on the workpiece while maintaining high deposition rates through improved wire feed efficiency.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent replaces conventional resistive heating methods with electric arc heating. The electric arc generates intense localized heat through electrical discharge between contact tips, providing more efficient and controlled preheating compared to traditional mechanical or resistive heating systems.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Temperature

If high current is used for preheating, then wire heating is effective, but system complexity and current requirements increase

Engineering Contradiction:
Improvewire preheating temperatureVSAvoidpreheating system complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent segments the preheating function into multiple contact tips arranged in a polyphase configuration. Each contact tip handles a portion of the heating task, distributing the current load and enabling effective preheating without requiring excessive current through a single point, thus reducing overall system complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The contact tips serve multiple functions: they provide electric arc heating for wire preheating, maintain structural support for the wire feed system, and enable polyphase current distribution. This multi-functionality reduces the need for separate dedicated heating components, simplifying the overall system.

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

3Productivity

If aluminum welding wire is used, then welding capability is achieved, but surface oxide layers and contaminants cause quality issues

Engineering Contradiction:
Improvewelding capabilityVSAvoidsurface oxide layers and contaminants
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent uses electric arc heating to remove surface oxide layers and contaminants from aluminum welding wire. The intense localized heat of the electric arc effectively breaks down and vaporizes oxide layers and organic contaminants, cleaning the wire surface before welding without requiring separate mechanical cleaning operations.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The electric arc preheating process performs preliminary cleaning of the wire surface before the wire reaches the weld zone. This preliminary action removes harmful oxide layers and contaminants in advance, ensuring clean metal-to-metal contact during welding and improving weld quality.

Inventive Principle:
Principle #10Preliminary action

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 enhances deposition rates, reduces hydrogen porosity, and prevents re-oxidation of aluminum wires, achieving higher thermal efficiency and improved weld quality by maintaining consistent performance across various metals and alloys.

Implementation Method 1

an apparatus for preheating welding wire using a tungsten arc

Methodology Applied
Scientific EffectElectric arc: Electric Arc

Implementation Method 2

Electrical power is applied to the welding wire and a circuit is completed through the workpiece to sustain a welding arc

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP3799987B1Apparatus and system for wire preheating using polyphase electric arc preheating
Publication Date: 2024.02.21 ILLINOIS TOOL WORKS INC
  • EP3799987B1 patent drawingFigure 1a
  • EP3799987B1 patent drawingFigure 1b
  • EP3799987B1 patent drawingFigure 2a

AI summary

the present application relates to an apparatus and to a system (300) for preheating and removing surface oxidation of a welding wire using electric arcs (322, 324, 326) via three or more tungsten electrodes (302, 304, 306) connected to a polyphaser preheating power source (308). Electric arc preheating of welding wire allows increased efficiency and deposition rates.