TIG Welding Cycle Control for Reliable Arc Re-Ignition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In interval welding, non-consumable tungsten electrodes can cool down during pauses, leading to ignition problems when re-establishing the welding arc, and there is a need for optimizing energy input to ensure reliable arc ignition and precise control of the welding process.
Innovation Solution
A method and apparatus that utilize settable welding cycles with high-current and low-current phases, including current pulses and high-frequency ignition pulses for contactless arc ignition, allowing for adjustable parameters such as time durations, current amplitudes, and pulse frequencies to optimize energy input and ensure reliable arc ignition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by stationary object
If the welding current is reduced during pause time to prevent excessive energy input, then the energy input into the workpiece is controlled, but the welding electrode cools down and causes ignition problems
Solution Approach 1:
The patent applies periodic action by using pulsed welding current with alternating high-current and low-current phases. During the low-current phase, the electrode temperature is maintained at a level sufficient for arc ignition, while during the high-current phase, welding proceeds normally. This periodic modulation resolves the contradiction by preventing continuous cooling that would prevent ignition, while still controlling overall energy input through the low-current pause periods.
Solution Approach 2:
The patent employs parameter changes by dynamically adjusting the welding current between two distinct levels (high and low) rather than maintaining a constant current. The low-current parameter during pause time prevents excessive energy input, while the high-current parameter during welding phases ensures reliable arc ignition and welding progress. This parameter modulation allows the system to satisfy both contradictory requirements at different time intervals.
2Reliability
If the welding current is maintained at high level to ensure reliable arc ignition, then the arc ignites reliably, but excessive energy input occurs during pause time
Solution Approach 1:
The pulsed welding current with periodic high-current and low-current phases allows the system to maintain high current only when needed for arc ignition and welding, while using low current during pause periods to reduce energy input. This temporal separation of functions resolves the contradiction between ensuring ignition reliability and controlling energy consumption.
Solution Approach 2:
The patent applies dynamics by making the welding current variable rather than static. The current dynamically switches between high and low levels based on the welding cycle phase, allowing the system to adapt energy input to the actual welding needs. This dynamic control prevents continuous high energy input during pauses while ensuring high current availability when arc ignition is required.
3Use of energy by stationary object
If interval welding is used to control energy input, then excessive energy input is prevented, but the non-consumable welding electrode cools down and causes ignition problems
Solution Approach 1:
The patent uses parameter changes by establishing a specific relationship between the low-current level and pulse duration that maintains the electrode temperature within a suitable range. The low-current parameter is set high enough to prevent excessive cooling during pauses, while the pulse duration is controlled to limit overall energy input. This parameter optimization resolves the contradiction between energy control and temperature maintenance.
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 enables reliable ignition of the welding arc and precise control of energy input, improving the quality of the welding seam by preventing excessive energy input and ensuring consistent arc establishment, even during pauses.
Implementation Method 1
at the beginning of the high-current welding phase, with the relevant welding cycle being set accordingly, high-frequency ignition pulses are applied for the contactless ignition of the welding arc
Implementation Method 2
an electric arc or welding arc SLB burns between a workpiece and a welding electrode
Implementation Method 3
After ignition of the welding arc, the non-consumable welding electrode is supplied with energy from a current source of the welding apparatus
Data Source
AI summary
A welding apparatus for welding workpieces by means of a welding arc which is ignited between a non-consumable welding electrode and the workpieces and produces a molten pool, wherein the welding is performed in a welding process including a plurality of welding cycles, the parameters of which can be set via an interface of the welding apparatus. Each welding cycle of the welding process has a high-current welding phase, during which a high welding current flows, and a low-current welding phase, during which a low welding current flows. In the high-current welding phase and/or in the low-current welding phase of, with the relevant welding cycle being set accordingly, current pulses can be applied, and at the beginning of the high-current welding phase, with the relevant welding cycle being set accordingly, high-frequency ignition pulses can be applied for the contactless ignition of the welding arc.