Dual Contact Tip Welding Wire Preheating for Reliable Arc Starts

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current welding techniques lack effective methods for ensuring a heated electrode wire at the start of the welding process, which can impact the initiation and performance of welding arcs and welds.

Innovation Solution

A welding system with a contact tip assembly that includes two electrically isolated contact tip portions, where one supplies a preheat current to heat the electrode wire and the other supplies the welding current, ensuring the electrode is preheated before welding, with a temperature monitoring system to maintain optimal preheat temperatures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a single contact tip is used for welding current, then the device complexity is low, but the electrode wire cannot be preheated before welding

Engineering Contradiction:
Improveelectrode wire temperatureVSAvoidcontact tip assembly complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The contact tip assembly is divided into two electrically isolated contact tip portions: a first contact tip portion for receiving preheat current and a second contact tip portion for receiving welding current. This segmentation allows independent control of preheating and welding functions, enabling electrode wire preheating while maintaining clear functional separation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system performs preliminary preheating of the electrode wire before the actual welding operation. The first contact tip portion applies preheat current to heat the electrode wire to a desired temperature range, ensuring optimal welding conditions are established before welding current is applied through the second contact tip portion.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If dual contact tip portions are used for preheat and welding current, then the electrode wire can be preheated, but the device complexity increases

Engineering Contradiction:
Improvewelding arc initiation reliabilityVSAvoidcontact tip assembly complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The contact tip assembly is divided into two electrically isolated contact tip portions: a first contact tip portion for receiving preheat current and a second contact tip portion for receiving welding current. This segmentation allows independent control of preheating and welding functions, enabling electrode wire preheating while maintaining clear functional separation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system includes a control system that monitors welding parameters and adjusts the preheat current accordingly. This feedback mechanism ensures the electrode wire reaches the optimal temperature range for reliable arc initiation, improving welding reliability while automating the complex dual-contact-tip operation.

Inventive Principle:
Principle #23Feedback

3Reliability

If preheat current is applied before welding, then the welding arc initiation is improved, but the energy consumption increases

Engineering Contradiction:
Improvewelding arc initiation reliabilityVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system performs preliminary preheating of the electrode wire before the actual welding operation. The first contact tip portion applies preheat current to heat the electrode wire to a desired temperature range, ensuring optimal welding conditions are established before welding current is applied through the second contact tip portion.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The preheat current is applied periodically or in controlled intervals before welding, rather than continuously. The control system manages the timing and duration of preheating, applying energy only when needed to maintain optimal electrode temperature, thereby reducing overall energy consumption while preserving arc initiation reliability.

Inventive Principle:
Principle #19Periodic 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 improves weld performance by consistently initiating welding arcs with a heated electrode, enhancing the quality and reliability of welds by ensuring the electrode wire is at the desired temperature before welding.

Implementation Method 1

a first contact tip portion and a second contact tip portion that are electrically isolated from each other (except through the electrode wire extending between the first and second contact tip portions) and each of which makes electrical contact with a same electrode wire during a welding operation; a first power supply operably coupled to the first contact tip portion that provides a welding current to the first contact tip portion during the welding operation; and a second power supply operably coupled to the second contact tip portion that provides a preheat current during the welding operation, wherein the preheat current enters the electrode wire at the second contact tip portion and exits at the first contact tip portion

Methodology Applied
Scientific EffectResistive heating: Joule Heating

Data Source

PatentEP3386671B1Systems to preheat welding wire
Publication Date: 2021.10.06 ILLINOIS TOOL WORKS INC
  • EP3386671B1 patent drawingFigure 1
  • EP3386671B1 patent drawingFigure 2A
  • EP3386671B1 patent drawingFigure 2B

AI summary

A contact tip assembly with a preheating tip comprises a welding-type power source (302a, 302b) configured to provide welding-type current to a welding-type circuit, the welding-type circuit comprising a welding-type electrode and a first contact tip (318) of a welding torch. The assembly also includes an electrode preheating circuit configured to provide preheating current through a portion of the welding-type electrode via a second contact tip (308) of the welding torch, and a voltage sense circuit (1702, 1704, 1706) to monitor a voltage drop across the two contact tips (308, 318), and the electrode preheating circuit adjusts at least one of the first current or the preheating current based on the voltage drop.