Dual-Contact Welding Torch for Preheated Wire Starts

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current welding techniques lack a method to ensure the electrode is heated prior to initiating welding operations, affecting the consistency and efficiency of the welding process, particularly in cold electrode starts.

Innovation Solution

A liquid-cooled welding torch with a power and liquid transfer assembly that conducts preheating current to the electrode, allowing for resistive heating of the electrode wire before forming a welding arc, while maintaining the same tool center point distance and torch neck angle as conventional torches.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a cold electrode start is used in welding operations, then the welding process can be initiated without preheating equipment, but the welding performance and consistency are compromised

Engineering Contradiction:
Improveease of welding initiationVSAvoidwelding performance consistency
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies preliminary action by incorporating a preheating contact tip that heats the electrode wire before welding begins. This preheating action occurs in advance of the main welding process, ensuring the electrode is at the optimal temperature for consistent welding performance without requiring external preheating equipment.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The contact tip is segmented into two distinct functional parts: a preheating contact tip and a welding contact tip. The preheating contact tip delivers current to heat the electrode, while the welding contact tip delivers current for the actual welding arc. This segmentation allows each tip to be optimized for its specific function, improving overall welding consistency.

Inventive Principle:
Principle #1Segmentation

2Reliability

If a preheating contact tip is added to the welding torch, then electrode preheating is achieved, but the device complexity increases

Engineering Contradiction:
Improvewelding start consistencyVSAvoidtorch structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the preheating and welding contact tips into a single integrated contact tip assembly that attaches to the welding torch in one piece. This merging approach consolidates multiple functions into a single component, reducing the overall device complexity compared to having separate preheating and welding torches or multiple detachable components.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The contact tip assembly serves multiple functions: it acts as both a preheating contact tip and a welding contact tip. This multi-functionality reduces the number of separate components needed, thereby simplifying the overall device structure while maintaining the benefits of electrode preheating.

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

3Device complexity

If the contact tip is designed to accept both preheating and welding currents, then the torch design is simplified, but the contact tip geometry becomes more complex

Engineering Contradiction:
Improvetorch assembly complexityVSAvoidcontact tip geometry
Core Design Contradiction:
Device complexityVSShape

Solution Approach 1:

The contact tip is designed with local quality variations: the preheating contact tip has a larger diameter and different surface characteristics optimized for delivering preheating current, while the welding contact tip has a smaller diameter and geometry optimized for arc initiation. Each local region of the contact tip assembly has properties tailored to its specific function, resolving the geometric complexity issue through functional specialization.

Inventive Principle:
Principle #3Local quality

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 solution enables improved welding starts and higher deposition rates by preheating the electrode wire, reducing the risk of collisions and requiring minimal reprogramming of robotic systems.

Implementation Method 1

a liquid cooling assembly configured to deliver the cooling liquid to the welding assembly

Methodology Applied
Scientific EffectForced Convection: Forced Convection

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

PatentEP3634684B1Welding torch with a first contact tip to preheat welding wire and a second contact tip
Publication Date: 2022.10.05 ILLINOIS TOOL WORKS INC
  • EP3634684B1 patent drawingFigure 1
  • EP3634684B1 patent drawingFigure 2
  • EP3634684B1 patent drawingFigure 3

AI summary

The present application relates to welding torches (1500). A 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 (1500) provides a same tool center point distance, a same bend angle, and a same approach angle when used to replace a second welding torch (1500) having a single contact tip.