Timepiece Case Laser Welding to Prevent Reflected-Light Damage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods of laser welding small components for timepieces, such as a main case body and an exterior member, face challenges with laser light reflection causing surface roughness and misalignment, leading to inaccurate positioning and contamination.
Innovation Solution
The welding part is formed on the inner periphery surface perpendicular to the incident laser light, preventing reflected light from melting adjacent surfaces and ensuring precise alignment and adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If laser light is irradiated at a slant onto the welding part from the inner side of the case, then the external appearance is not affected and fewer components are required, but the reflected laser light melts adjacent surfaces causing surface roughness and positioning errors
Solution Approach 1:
The patent applies asymmetry by designing the welding part with a specific inclination angle (α) that is not symmetric with respect to the laser beam direction. The welding part is inclined such that the laser beam irradiates it at an angle that minimizes harmful reflections while maintaining effective welding, creating an asymmetric geometry that resolves the contradiction between appearance preservation and surface accuracy
Solution Approach 2:
The patent changes the geometric parameters of the welding part, specifically the inclination angle (α), to optimize the laser beam interaction. By adjusting this parameter, the system achieves both aesthetic appearance (no visible welds from outside) and manufacturing precision (no harmful reflections affecting adjacent surfaces), resolving the technical contradiction
2Ease of manufacture
If laser light is irradiated at a slant onto the welding part, then it is possible to weld from the inner side without affecting external appearance, but the reflected light causes adjacent surfaces to melt and become rough
Solution Approach 1:
The patent converts the harmful reflection into a beneficial outcome by carefully designing the inclination angle of the welding part. The reflection that would normally cause damage is redirected away from adjacent surfaces, and the same geometric configuration that creates the reflection also ensures complete welding penetration and strong bonding, thus converting a harmful effect into a beneficial one
Solution Approach 2:
By changing the inclination angle parameter (α) of the welding part, the system controls the direction and intensity of reflected laser light. This parameter optimization ensures that reflections are directed away from sensitive adjacent surfaces while maintaining effective welding, thereby reducing harmful effects while preserving manufacturing ease
3Productivity
If the irradiation surface is not perpendicular to the incident laser light, then welding can be performed from the inner side, but the reflected light arrives at adjacent surfaces causing melting and roughness
Solution Approach 1:
The patent uses asymmetric design of the welding part inclination to differentiate between the welding function and the reflection control function. The asymmetric angle allows the surface to be non-perpendicular to the laser beam, enabling inner-side welding access, while simultaneously directing reflections away from adjacent surfaces, thus maintaining positioning accuracy
Solution Approach 2:
The patent optimizes the inclination angle parameter (α) of the welding part to balance welding efficiency and positioning accuracy. By selecting an appropriate angle range, the system achieves effective welding from the inner side while preventing reflected light from affecting adjacent surfaces, thereby resolving the contradiction between productivity and manufacturing precision
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 maintains high surface accuracy, prevents contamination, and allows for precise positioning of internal components, resulting in a thinner, more accurately assembled timepiece case.
Implementation Method 1
The exterior member is welded to the main case body with laser light
Implementation Method 2
from the welding part irradiated with the laser light, the laser light is reflected, and a part on which the reflected light has arrived might be melt
Implementation Method 3
from the welding part irradiated with the laser light, the laser light is reflected, and a part on which the reflected light has arrived might be melt
Data Source
AI summary
A case includes a main case body and an exterior member. The exterior member is welded to the main case body with laser light. The laser light is irradiated onto an irradiation surface. A welding part of the main case body and the exterior member is formed on the inner periphery surface extending along a height direction of the case and is formed such that the irradiation surface is perpendicular to the incident laser light.