Arc Welding Current Control Using Integrated Power Detection
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Solution Overview
Problem
When using welding wires with low resistance materials like copper or aluminum, the small variation in welding voltage can lead to erroneous constriction detection, resulting in increased heat input and spatter generation during short-circuit opening.
Innovation Solution
An arc welding method that calculates an integrated power value after the welding wire is short-circuited and reduces the welding current if the integrated power exceeds a predetermined threshold, thereby reducing heat input and preventing spatters before the short-circuit is opened.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If welding voltage variation is used to detect constriction, then constriction detection is achieved, but detection precision deteriorates when using low resistance materials like copper or aluminum
Solution Approach 1:
The patent changes the detection parameter from voltage variation to integrated power value. By integrating power (P=VI) over a predetermined time period after short-circuit, the system accumulates enough signal to detect constriction reliably even with low resistance materials where voltage variation is minimal. This parameter transformation resolves the measurement precision issue while maintaining detection reliability.
2Productivity
If welding current is not reduced before short-circuit opening, then welding process continuity is maintained, but spatter generation increases due to excessive heat input
Solution Approach 1:
The patent applies preliminary action by reducing welding current before the short-circuit opens. The controller detects constriction through integrated power value and proactively reduces current to a reduced value before opening occurs. This preliminary current reduction prevents excessive heat input and spatter generation while maintaining process continuity through controlled transitions.
Solution Approach 2:
The system uses feedback by continuously monitoring the integrated power value during the short-circuit period and using this information to control welding current. When the integrated power exceeds a threshold indicating constriction, the feedback loop triggers current reduction. This closed-loop control balances productivity and spatter prevention dynamically.
3Loss of time
If integrated power value is calculated immediately after short-circuit, then response time is reduced, but calculation accuracy deteriorates due to unstable short-circuit state
Solution Approach 1:
The patent applies preliminary action by waiting for the short-circuit to stabilize before starting integrated power calculation. The controller waits for a predetermined time period after short-circuit occurrence, ensuring the welding wire and base material are in a stable contact state. This preliminary stabilization period improves calculation accuracy while the predetermined time threshold keeps the overall response time acceptable.
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 effectively reduces spatter occurrence by accurately controlling the welding current based on the integrated power supplied, even when constriction detection is erroneous due to low resistance materials, ensuring stable heat application and minimizing defects.
Implementation Method 1
an arc period provided with an arc state where an arc is generated between the welding wire and the base material
Implementation Method 2
a short-circuit period provided with a short-circuit state where a welding wire and a base material are short-circuited
Implementation Method 3
power supplied to the welding wire within a predetermined period after the welding wire is short-circuited
Data Source
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AI summary
Provided is an arc welding device that performs welding by alternately repeating a short-circuit period provided with a short-circuit state in which a welding wire and a base material are short-circuited, and an arc period provided with an arc state in which an arc is generated between the welding wire and the base material. A calculation unit calculates an integrated power value by integrating power supplied to the welding wire within a predetermined period, after the welding wire is short-circuited. A controller reduces a welding current to be supplied to welding wire when the integrated power value is larger than a predetermined threshold.