Arc Welding Control for Thin Plate Burn-Through Prevention
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Solution Overview
Problem
Conventional arc welding control methods fail to reduce energy input during welding of thin plates with thicknesses of 0.6 mm or less, leading to burn-through issues.
Innovation Solution
An arc welding control method and apparatus that alternately generate short circuit and arc states by controlling wire feeding speed and welding current, using a system with a primary side rectifying unit, switching unit, main transformer, and polarity inversion setting unit to manage the welding process, thereby reducing energy input to the base metal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional arc welding control method is used with cyclic wire feeding speed control, then stable welding can be carried out on plates with thickness of 0.8 mm or more, but burn-through occurs on thin plates with thickness of 0.6 mm or less due to large energy input amount
Solution Approach 1:
The patent applies periodic action by controlling the wire feeding speed to cyclically repeat forward feeding and backward feeding, which causes the welding current to periodically vary between short circuit state and arc state. This periodic control reduces the average energy input to the base metal, enabling welding of thin plates (0.6 mm or less) without burn-through while maintaining stable welding through controlled short circuit frequency
Solution Approach 2:
The patent changes the wire feeding speed parameter dynamically during the welding process. By controlling the wire feeding motor to vary the wire feeding speed between forward and backward directions, the welding current parameters are automatically adjusted, transitioning between high current short circuit state and lower current arc state, thereby reducing overall energy input to prevent burn-through on thin plates
2Use of energy by stationary object
If wire feeding speed is controlled to cyclically repeat forward feeding and backward feeding, then energy input to base metal is reduced, but welding process complexity increases due to need for precise control of short circuit frequency and timing
Solution Approach 1:
The patent employs feedback control by detecting the welding current state and adjusting the wire feeding speed accordingly. The control system monitors whether the welding current is in short circuit state or arc state and automatically adjusts the wire feeding motor to maintain the desired cyclic pattern, ensuring stable short circuit frequency without requiring complex manual coordination of multiple parameters
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 successful welding of thin plates without burn-through by reducing energy input to the base metal, improving welding efficiency and preventing damage.
Implementation Method 1
an arc welding control method of repeating a short circuit and an arc to perform welding
Data Source
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AI summary
In an arc welding control method of repeating a short circuit and an arc to perform welding, control is carried out to conduct a welding current having a first polarity for a short circuit period, and a first commutation to commutate the welding current from the first polarity to be a polarity of the welding current for the short circuit period to a second polarity to be opposite to the first polarity is carried out for an arc period subsequent to the short circuit period. Furthermore, control is performed to carry out a second commutation to commutate the welding current from the second polarity to the first polarity for the arc period in which the first commutation is executed. Consequently, it is possible to reduce an energy input amount to a base metal, thereby suppressing burn-through in welding of a thin plate.