Variable-Focus Laser Welding for Complex Joint Penetration Control
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Solution Overview
Problem
Conventional laser welding methods struggle to ensure adequate bonding strength and penetration shape when welding complex-shaped workpieces, often resulting in impaired outer appearances due to spatter and insufficient penetration.
Innovation Solution
A laser welding device and method that includes a controller to adjust the focal position of the laser beam in accordance with the shape of the welded portion, allowing for two- or three-dimensional scanning and precise control of penetration depth and shape.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the focal position of the laser beam is fixed on the surface of the workpiece, then the welding process is simple to control, but the penetration shape and bonding strength cannot be ensured for complex-shaped workpieces
Solution Approach 1:
The patent applies dynamics by making the focal position of the laser beam variable rather than fixed. The controller dynamically adjusts the focal position along the welding trajectory to match the three-dimensional shape of the welded portion, enabling the penetration depth to adapt to varying workpiece geometries and ensuring consistent bonding strength across complex surfaces
Solution Approach 2:
The patent changes the focal position parameter of the laser beam according to the workpiece shape. By modifying this critical parameter in response to the three-dimensional profile of the welded portion, the system achieves precise control over penetration shape and depth without requiring complex mechanical adjustments to the welding head position
2Strength
If the focal position is adjusted to match complex workpiece shapes, then bonding strength and penetration shape are improved, but the control system becomes more complex
Solution Approach 1:
The patent implements feedback control where the controller receives information about the three-dimensional shape of the welded portion and automatically adjusts the focal position accordingly. This closed-loop approach ensures optimal bonding strength is achieved by continuously adapting the focal position to match the actual workpiece geometry, eliminating the need for manual intervention or complex mechanical systems
3Object-affected harmful factors
If conventional focal position control is used, then the welding process is simple, but spatter occurs and outer appearance is impaired
Solution Approach 1:
The patent uses dynamic focal position adjustment to prevent spatter by adapting the focal position to the workpiece surface profile. This dynamic control ensures the laser energy is consistently focused at the optimal depth throughout the welding process, preventing the formation of spatter and maintaining smooth outer appearance of the welded portion
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 effectively controls the penetration shape and depth of the workpiece, enhancing bonding strength and preventing spatter, thereby improving the overall quality of the welded portion.
Implementation Method 1
a laser oscillator that generates a laser beam
Implementation Method 2
an optical fiber that transmits the laser beam generated in the laser oscillator
Implementation Method 3
A long-focus condensing lens is mounted on the scanner
Implementation Method 4
a laser welding step of emitting the laser beam toward the workpiece while scanning the laser beam two-dimensionally or three-dimensionally to weld the workpiece
Implementation Method 5
a molten pool and a keyhole are formed in the workpiece
Data Source
AI summary
Laser welding device (1000) includes: laser oscillator (100); optical fiber (300) that transmits a laser beam (LB) generated in laser oscillator (100); laser beam emitting head (400) that is attached to the emission end of optical fiber (300) and emits laser beam (LB) toward workpiece (600); manipulator (500) with laser beam emitting head (400) attached thereto; and controller (200) that controls laser beam emitting head (400) so as to cause laser beam (LB) to be scanned three-dimensionally on the surface of workpiece (600). Controller (200) controls laser beam emitting head (400) so as to change a focal position of laser beam (LB) in accordance with a shape of a welded portion in workpiece (600).