High-Frequency Negative Polarity Welder for Stacked Dime Beads
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Gas metal arc welding (GMAW) struggles to achieve a 'stacked dime' weld appearance at speeds comparable to steady state GMAW processes, often resulting in inconsistent results and issues like spattering and stubbing due to the need for significant differences in pulse parameters.
Innovation Solution
An electric arc welder with a high-speed switching power supply and controller generating high-frequency current pulses, including negative polarity components, to modulate heat effectively and achieve the 'stacked dime' appearance at faster speeds without spattering or stubbing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If significant differences in pulse parameters are used to achieve stacked dime appearance, then the desired bead appearance is achieved, but spattering and stubbing occur
Solution Approach 1:
The patent applies periodic action by using high-frequency current pulses (e.g., 100-1000 Hz) to create rapid alternating high and low energy portions within the weld cycle. This periodic modulation allows the weld puddle to repeatedly expand and cool, forming stacked dime ridges while maintaining stable arc characteristics that prevent spattering and stubbing. The high-frequency pulsing creates many small, controlled thermal cycles rather than large, uncontrolled parameter swings.
Solution Approach 2:
The patent implements parameter changes by dynamically modulating current amplitude and polarity at high frequencies during the welding process. The controller varies these parameters periodically to create the desired stacked dime appearance while keeping the average parameters within a stable range that prevents harmful effects like spattering. The wave shape generator defines the specific temporal profile of these parameter variations.
2Manufacturing precision
If wire feed speed is modulated to achieve stacked dime appearance, then the desired bead shape is achieved, but travel speed must be slowed down
Solution Approach 1:
The patent uses high-frequency periodic action in the current pulses to achieve bead shaping without requiring slow modulation of wire feed speed. The rapid thermal cycles created by high-frequency pulsing allow the weld puddle to form stacked dime ridges while the wire feed speed can maintain a more constant, higher rate, thus preserving travel speed and productivity.
Solution Approach 2:
The patent replaces the mechanical approach of modulating wire feed speed with an electrical approach of modulating current parameters. Instead of physically varying the wire feed mechanism at low frequencies (which limits travel speed), the invention uses high-frequency electrical pulse modulation to achieve the same bead shaping effect, allowing faster overall welding speeds.
3Manufacturing precision
If torch shuffling is performed to achieve stacked dime appearance, then the desired appearance is achieved, but operator manipulation complexity increases and results become inconsistent
Solution Approach 1:
The patent replaces the manual mechanical operation of torch shuffling with an automated electrical control system. The controller generates precise high-frequency current pulses with defined wave shapes, eliminating the need for operator skill in manual torch manipulation. This automation ensures consistent stacked dime appearance without requiring complex operator actions, thereby improving ease of operation and result consistency.
Solution Approach 2:
The welding system performs the bead shaping function through automated current modulation rather than requiring operator intervention. The controller and wave shape generator automatically create the necessary thermal cycles in the weld puddle, allowing the process to self-regulate the bead formation without operator manipulation, thus simplifying operation and ensuring consistency.
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 the production of a 'stacked dime' weld appearance at speeds similar to steady state GMAW processes while minimizing spattering and stubbing, by effectively controlling heat through alternating high and low energy portions of the weld cycle using high-frequency current pulses with negative polarity components.
Implementation Method 1
The high energy portion delivers high heat to the weld puddle/pool, whereas the low energy portion delivers relatively low heat to the weld puddle
Implementation Method 2
the modulation of current in the process serves to alternately expand and cool the puddle
Implementation Method 3
high frequency pulses between a workpiece and a welding wire advancing toward the workpiece
Data Source
AI summary
An electric arc welder including a high speed switching power supply with a controller for creating high frequency current pulses with negative polarity components through the gap between a workpiece and a welding wire advancing toward the workpiece, where the pulses and a background current defining a series of weld cycles. A wave shape generator defines the shape of the pulses and the background current including a controlled ramp up and/or ramp down in each of said cycles, and a circuit to change the shapes of the pulses and/or background current in a repeating pattern in each of the weld cycles, including a negative current in at one of said pulses. The shape change in a cycle can be between first and second shapes or by a rhythmic AC modulation.