Laser Welding Shield Gas Timing for Stable Weld Starts
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Solution Overview
Problem
Existing laser welding devices face inefficiencies in shield gas consumption and weld quality due to unstable gas feeding rates during the movement of the laser processing head to the welding position.
Innovation Solution
The laser welding method stabilizes the shield gas feeding rate by starting gas emission when the laser processing head reaches the starting position for welding, using a control device to calculate and optimize the gas emission timing based on travel path data and gas feeding rate stability tables, allowing for efficient and stable gas supply during welding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If shield gas is emitted from the beginning of movement to the starting position, then the feeding rate becomes stable at welding start, but shield gas consumption increases due to emission during movement
Solution Approach 1:
The control device calculates and determines the optimal gas emission start timing in advance, before the laser processing head reaches the starting position. Gas emission begins at a calculated timing that accounts for the time required to reach the starting position plus a predetermined margin, ensuring the feeding rate is stable when welding starts while minimizing unnecessary emission during movement.
2Reliability
If shield gas emission starts before reaching the starting position, then feeding rate stability is achieved, but weld quality deteriorates due to unstable feeding rate during movement
Solution Approach 1:
The control device performs preliminary calculation of the optimal gas emission start timing based on travel path data and gas feeding rate characteristics. This predetermined timing ensures that gas emission begins early enough to stabilize the feeding rate before welding, but not so early that instability occurs during movement, thereby ensuring both feeding rate stability and weld quality.
Solution Approach 2:
The control device uses predetermined gas feeding rate characteristic data to determine the optimal emission timing. This feedback mechanism ensures that the gas emission timing is adjusted based on the actual feeding rate characteristics, maintaining stable feeding rate and high weld quality.
3Loss of substance
If shield gas emission starts at the starting position, then gas consumption is reduced, but feeding rate instability occurs at welding start
Solution Approach 1:
The control device calculates the optimal emission start timing in advance, setting it to begin before the laser processing head reaches the starting position. This preliminary action ensures that the gas feeding rate has sufficient time to stabilize before welding begins, achieving both reduced consumption and stable feeding rate.
4Reliability
If shield gas emission is continuous during movement and welding, then feeding rate stability is maintained, but welding efficiency decreases due to wasted gas during non-welding movement
Solution Approach 1:
The control device determines the optimal gas emission start timing in advance, calculating when to begin emission based on the travel path and gas feeding characteristics. This ensures gas emission starts early enough to stabilize the feeding rate but stops or reduces when movement completes, eliminating waste during non-welding periods while maintaining stability during welding.
Solution Approach 2:
The control device manages gas emission as a periodic process, starting emission at the calculated timing before reaching the starting position and controlling it to stabilize before welding. This periodic control ensures gas is emitted only when necessary for stability, improving efficiency by eliminating continuous emission during entire movement cycles.
Data Source
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AI summary
A laser welding method is constituted of: emitting shield gas in advance through a laser nozzle provided on a laser processing head at a time of moving the laser processing head from a reference position to a starting position for welding the workpiece; and radiating laser light onto the workpiece through the laser nozzle at the starting position for welding when a feeding rate of the shield gas gets stabilized, whereby perfoming laser welding on the workpiece.