Arc Welder Heat Control via Segmented AC Waveforms
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Solution Overview
Problem
Conventional electric arc welding methods struggle to accurately control heat input during weave welding due to noisy electrode position tracking, especially with pulsed and AC waveforms, leading to inadequate determination of welding parameters for varying gap widths.
Innovation Solution
An electric arc welder with a power source providing distinct AC waveforms for different regions along the weld seam, using a controller to oscillate the welding torch and determine stickout values and seam tracking based on specific portions of the waveforms, allowing for precise heat control and parameter adjustment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional electrode position tracking is used during arc welding, then the welding process can be monitored, but the tracking is too noisy and not responsive enough to accurately determine when to change welding parameters
Solution Approach 1:
The welding waveform is segmented into distinct positive and negative half-cycles, with different functions assigned to each. The positive half-cycle is used for seam tracking while the negative half-cycle is used for stickout determination, allowing each segment to be optimized for its specific purpose and reducing noise interference
Solution Approach 2:
The system changes the functional parameter being measured during different phases of the AC waveform. By switching between using positive and negative half-cycles for different measurements (seam tracking vs. stickout), the system adapts to varying conditions and maintains accuracy throughout the welding process
2Ease of operation
If a fixed heat input level is selected for welding, then the welding process is simple to control, but it cannot account for varying gap widths and workpiece depths at different locations
Solution Approach 1:
The welding system transitions from static fixed heat input to dynamic adaptive heat control. The controller continuously adjusts welding parameters based on real-time electrode position and seam tracking data, allowing the heat input to vary dynamically throughout the welding process to match local workpiece conditions
Solution Approach 2:
The system implements feedback control by continuously monitoring electrode position through seam tracking and using this information to adjust welding parameters. The controller receives feedback from the welding process and automatically modifies heat input to maintain optimal welding conditions across varying gap widths
3Strength
If the electrode is paused at outermost lateral extent to increase penetration, then heat input to that portion increases, but the electrode must remain in motion at seam locations to avoid burning through
Solution Approach 1:
The system uses periodic oscillation of the electrode in a weave pattern throughout the welding process. This continuous periodic motion prevents burning through at the seam while the control system strategically pauses or extends pause duration at outermost lateral positions to maximize penetration where workpiece depth permits
Solution Approach 2:
The control system applies different motion control strategies to different locations along the weld seam. At outermost lateral extents where workpiece depth tolerates high heat, the system pauses to maximize penetration. At seam locations between workpieces, the system maintains continuous motion to prevent burning through, creating location-specific motion patterns
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
Enables accurate determination of weld current and voltage for heat control, improving the precision of welding parameters and preventing burn-through by adapting heat input based on the location along the weld seam.
Implementation Method 1
a power source that provides a welding waveform to a welding electrode to generate an arc to achieve a desired heat for welding
Implementation Method 2
an oscillator configured to oscillate the welding torch to generate the weave pattern along the weld seam
Data Source
AI summary
An arc welder produces a weave pattern between workpieces. Each weld run comprises a center portion including a joining region between the workpieces and edge regions spaced apart from the joining region. The welder includes a power source that provides a welding waveform to a welding electrode to generate an arc to achieve a desired heat for welding, a welding torch, and an oscillator for oscillating the torch between the welding edge regions. A controller causes the power source to operate in a first mode utilizing a first waveform during welding within the joining region, and in a second mode using a second waveform, having a greater positive component than the first waveform, during welding within the edge regions. The controller determines a stickout value based on the first waveform but not the second waveform, and performs seam tracking based the second waveform but not the first waveform.