Line-Shaped Laser Welding for Uniform Bead Formation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional line-shaped laser welding of metal members faces challenges due to differences in heat input and joint width, leading to inconsistent welding quality, particularly with metal thicknesses requiring longer heating times and larger bead widths, resulting in heat loss at ends and quality variations.
Innovation Solution
A method involving a line-shaped laser beam with varying intensity and width, where the beam is longer and more intense at ends than in the central portion, and assist gas flow rates are adjusted to maintain consistent heat application, preventing metal oxidation and ensuring a bead without depressions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a line-shaped laser beam with uniform intensity is used for welding metal, then the welding process can be simplified, but the welding quality becomes inconsistent between the center and ends due to heat loss at the ends
Solution Approach 1:
The patent applies local quality by making the laser beam intensity non-uniform, specifically higher at the ends and lower in the center. This compensates for heat loss at the ends during welding, ensuring consistent melting and welding quality throughout the entire weld line, thereby resolving the contradiction between simplified process and consistent quality.
2Length of stationary object
If the laser beam is made longer to increase joint width, then more heat escapes at the ends, but if the beam is shorter, the joint width becomes too small to achieve sufficient joint strength
Solution Approach 1:
The patent changes the intensity distribution parameter of the laser beam, making it higher at the ends and lower in the center. This allows the use of a longer beam for sufficient joint width while compensating for end heat loss through increased intensity, thus resolving the contradiction between joint width and heat loss.
3Duration of action of moving object
If a pulsed laser on the μs order is used for heating, then the irradiation time is short, but welding cannot be performed for metal several hundred μm or more thick which requires heating time of several tens of ms or more
Solution Approach 1:
The patent applies local quality by concentrating higher laser intensity at the ends of the beam where heat loss is greatest. This allows for sufficient heating of thick metal sections at the ends without requiring extended irradiation time, enabling reliable welding of thick metal while maintaining short pulse duration.
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 enhances welding quality by maintaining consistent joint strength across the weld line, reducing heat loss, and preventing metal oxidation, resulting in stable and high-quality welds with improved reliability and cost-effectiveness.
Implementation Method 1
irradiating the first surface of the first member with a line-shaped laser beam
Implementation Method 2
causing a solidified portion formed by irradiation with the line-shaped laser beam to join the first member and the second member
Implementation Method 3
welding method of a metal member... irradiating the first surface of the first member with a line-shaped laser beam... causing a solidified portion formed by irradiation with the line-shaped laser beam to join the first member and the second member
Data Source
AI summary
In a metal member, a second member is overlaid on a second surface of a first member, the first member having a first surface and the second surface that face in opposite directions. A solidified portion is a portion produced by melting the first member from the first surface thereof as far as the second member via the second surface. The solidified portion has a bead protruding from the first surface. Defining a first direction and a second direction that intersect within the first surface, the bead has a line shape more elongated along the first direction than along the second direction, and the bead does not have depression.