Laser Welding Joint Structure with Annular Seal
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Solution Overview
Problem
Existing methods for laser transmission welding, such as those using a glass plate for pressurization, face issues like contamination, breakage, and decreased welding strength due to insufficient laser beam penetration, and suction methods can lead to thermal deformation and air leakage, affecting adhesiveness.
Innovation Solution
A joint structure comprising a light-absorbable member with an opening portion covered by a light-permeable member, forming an annular weld part with a specific area ratio and using suction to deform the light-permeable member for adherence, eliminating the need for a glass plate and enhancing adhesiveness by controlling pressure and thermal influence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a glass plate is used for pressurization in laser transmission welding, then the members can be adhered to each other, but the glass plate is contaminated with soot and volatile ingredients, causing breakage and shielding the laser beam
Solution Approach 1:
The invention removes the glass plate from the welding system entirely. Instead of using a glass plate for pressurization, the patent forms an annular weld part that directly joins the light-absorbable and light-permeable members without any intermediate pressurization medium, thereby eliminating contamination and breakage issues
Solution Approach 2:
The annular weld part acts as an intermediary structure that provides both the joining function and the pressurization function. By forming this weld part with specific area ratios, the invention achieves reliable adhesion without requiring a separate glass plate mediator
2Strength
If the light-permeable member is heated by laser beam irradiation, then welding occurs, but thermal deformation is caused generating gaps that decrease adhesiveness by sucking
Solution Approach 1:
The invention concentrates the laser beam heating in a specific annular region to form the weld part, while the central opening portion remains unheated. This localized heating approach prevents thermal deformation in the central area that would otherwise generate gaps and reduce adhesiveness
Solution Approach 2:
The welding process is segmented into two distinct zones: an annular weld part for joining and a central opening portion for maintaining adhesiveness. This segmentation allows different thermal conditions in different regions, solving the contradiction between welding strength and adhesiveness stability
3Strength
If the area ratio of the light-absorbable member portion to the light-permeable member portion is not controlled, then welding may occur, but uniform adherence cannot be achieved
Solution Approach 1:
The invention specifies precise parameter ranges for the area ratio (15-35%) and thickness ratio (0.01-0.5mm) of the weld part. By controlling these parameters, the patent achieves both sufficient joining strength and uniform adherence across the joint structure
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 ensures strong and uniform adherence between members without a glass plate, reducing thermal strain and maintaining high joining strength while preventing air leakage and thermal deformation.
Implementation Method 1
a member having a permeability to a laser beam (light-permeable member) is used as a joining member and a member having an absorbability to a laser beam (light-absorbable member) is used as the other joining member and these members are superposed to each other and exposed to a laser beam from the light-permeable member at a pressurized state, whereby energy of the irradiated laser beam is absorbed by the light-absorbable member in the neighborhood of a boundary face thereof to cause heat generation
Implementation Method 2
the generated heat is transferred to the light-permeable member to fuse the both members, and finally the fused portions are cooled and solidified to join the both members to each other
Implementation Method 3
a groove portion is formed in one of the members to be joined and the both members are adhered to each other by depressurizing a space of the groove portion
Implementation Method 4
the both members are adhered to each other by depressurizing a space of the groove portion
Data Source
AI summary
A joint structure comprising a light-absorbable member having at least one opening portion and a light-permeable member superposed on the light-absorbable member so as to cover the opening portion, wherein an annular weld part is formed so as to enclose the opening portion and join the light-absorbable member and the light-permeable member, and an area ratio of a portion at the side of the light-absorbable member to a portion at the side of the light-permeable member side is in a range of 12-35 viewing a section perpendicular to the extending direction of the annular weld part.