Submerged Arc Welding Voltage Control for Stable Arc Length
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Solution Overview
Problem
Conventional submerged arc welding methods face challenges in maintaining accurate arc length control due to sensitive feed speed fluctuations and errors in welding voltage, leading to unstable welding states and improper setting and control of welding conditions.
Innovation Solution
A submerged arc welding control method and system that utilize a negative slope in external characteristics and variable speed control to converge the welding current and voltage at a set intersection point, ensuring proper arc length management and stable welding conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a large gain is set to sharply increase or decrease the feed speed to quickly reduce voltage error, then the response speed improves, but the feed speed fluctuates too sensitively causing unstable welding state
Solution Approach 1:
The control method dynamically adjusts the feed speed based on the magnitude of voltage error. When voltage error is large, a larger gain is applied for rapid correction; when voltage error is small, a smaller gain is applied to prevent oscillation. This dynamic gain adjustment enables both fast response and stable welding state.
Solution Approach 2:
The control system changes the control parameter (feed speed) in proportion to the voltage error magnitude. By setting the proportional gain appropriately, the system achieves a balance between response speed and stability, avoiding both slow convergence and excessive fluctuation.
2Measurement precision
If conventional variable speed control is used to maintain arc length, then the welding voltage can be controlled, but the welding voltage will have an error from the voltage set value causing issues in setting and control of welding conditions
Solution Approach 1:
The control system uses feedback control where the detected welding voltage is continuously compared with the voltage set value. The feed speed is adjusted based on the voltage error to maintain the arc length, ensuring both precise arc length control and accurate welding conditions.
Solution Approach 2:
The patent replaces conventional constant current control with a control system that incorporates voltage feedback and proportional control. This substitution enables simultaneous control of both welding current and welding voltage, improving manufacturing precision.
3Stability of the object's composition
If a small gain is set to maintain stable feed speed, then the welding state stability improves, but the convergence with error remaining between detected welding voltage and voltage set value
Solution Approach 1:
The control system changes the control parameter (feed speed) in proportion to the voltage error. By setting the proportional gain appropriately, the system achieves a balance between response speed and stability, avoiding both slow convergence and excessive fluctuation.
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 method and system effectively reduce steady-state deviations and enhance transient response, ensuring that the welding conditions are properly set and controlled, maintaining a stable welding state.
Implementation Method 1
a welding wire is fed into the flux to generate an arc between the tip of the welding wire and the base metal for welding
Data Source
AI summary
A submerged arc welding control method is provided for performing welding by feeding a welding wire and outputting a welding current and a welding voltage in accordance with set external characteristics. The method includes: setting a current set value and a voltage set value; setting the external characteristics so as to pass through an intersection point of the current set value and the voltage set value and have a negative slope at the intersection point; performing variable speed control of feed speed of the welding wire such that the welding voltage is equal to the voltage set value; and causing an operating point of the welding current and the welding voltage to converge at the intersection point of the external characteristics.