Dual-Contact Welding Torch for Wire Preheating Without TCP Shift

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Solution Overview

Problem

Current welding techniques lack a regime to ensure the electrode is heated prior to the initiation of a welding operation, affecting initial welding performance.

Innovation Solution

A liquid-cooled welding torch with a design that includes a first contact tip for conducting welding current and a second contact tip for conducting preheating current, along with liquid cooling assemblies to provide cooling and preheat the electrode wire, allowing for resistive preheating and maintaining the same tool center point distance and angle as conventional torches.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a single contact tip is used in conventional welding torches, then the device complexity is reduced and ease of manufacture is improved, but the ability to preheat the electrode wire before welding cannot be achieved

Engineering Contradiction:
Improvewelding start performanceVSAvoidcontact tip configuration
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The single contact tip is segmented into two separate contact tips: a first contact tip for conducting welding current and a second contact tip for conducting preheating current. This segmentation allows independent control of welding and preheating functions, improving welding start performance while maintaining manageable device complexity through modular design

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The welding torch is designed with multi-functionality by incorporating both welding current conduction and preheating current conduction through separate contact tips. This allows the same torch to perform both welding and preheating operations, eliminating the need for separate equipment and improving overall system versatility

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

2Productivity

If a second contact tip for preheating current is added, then the electrode can be preheated before welding improving deposition rates, but the torch geometry and tool center point may change requiring robotic system reprogramming

Engineering Contradiction:
Improvedeposition rateVSAvoidcompatibility with existing robotic systems
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The second contact tip is positioned at a specific location that maintains the same tool center point distance and angle as conventional single-contact-tip torches. This localized positioning ensures compatibility with existing robotic welding systems while adding the preheating function, allowing improved deposition rates without requiring system reprogramming

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The preheating current is applied to the electrode wire before the welding operation begins, preparing the electrode in advance. This preliminary action increases the electrode temperature prior to welding, improving welding start performance and deposition rates while maintaining compatibility with standard robotic workflows

Inventive Principle:
Principle #10Preliminary action

3Temperature

If liquid cooling assemblies are added to manage heat from two contact tips, then thermal management is improved, but the device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improvecontact tip temperature controlVSAvoidtorch assembly complexity
Core Design Contradiction:
TemperatureVSEase of manufacture

Solution Approach 1:

The liquid cooling assemblies are integrated into the existing torch structure, merging the cooling function with the contact tip housing. This combination approach manages thermal loads from both contact tips while avoiding the need for separate cooling systems, reducing manufacturing complexity compared to adding entirely new cooling components

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

Liquid cooling assemblies serve as an intermediary thermal management system between the two contact tips and the environment. The cooling liquid acts as a mediator that absorbs excess heat from the contact tips and dissipates it through the torch structure, effectively managing temperatures without requiring complex active cooling mechanisms

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Improves welding starts and deposition rates by ensuring the electrode is preheated, reducing the risk of collisions and requiring minimal reprogramming of robotic systems.

Implementation Method 1

a first contact tip configured to conduct welding current to a consumable electrode

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

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

Methodology Applied
Scientific EffectArc welding: Electric Arc

Implementation Method 3

a second contact tip configured to conduct preheating current to the consumable electrode

Methodology Applied
Scientific EffectResistive heating: Joule Heating

Implementation Method 4

liquid cooling assemblies configured to: conduct the preheating current; conduct the welding current to the consumable electrode; and provide cooling liquid to the welding assembly

Methodology Applied
Scientific EffectLiquid cooling: Cooling

Data Source

PatentEP4151349A1Welding torch with two contact tips and same tool center point as torch with one contact tip
Publication Date: 2023.03.22 ILLINOIS TOOL WORKS INC
  • EP4151349A1 patent drawingFigure 1
  • EP4151349A1 patent drawingFigure 2
  • EP4151349A1 patent drawingFigure 3

AI summary

Systems, methods, and apparatus to preheat welding wire are disclosed. An example welding torch includes: a welding assembly comprising: a first contact tip configured to conduct welding current to a consumable electrode; and a second contact tip configured to conduct preheating current to the consumable electrode; a neck having a bend, the neck configured to hold the welding assembly and to deliver the consumable electrode to the welding assembly; a torch body configured to hold the neck opposite the welding assembly; and a torch mounting assembly; wherein the welding assembly, the neck, the bend, the torch body, and the torch mounting assembly are dimensioned such that the welding torch provides a same tool center point distance, a same bend angle, and a same approach angle when used to replace a second welding torch having a single contact tip.