Laminated Automobile Glass With Controlled Inner-Side Crack Initiation
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Solution Overview
Problem
Laminated glass for automobile windows needs to break appropriately to reduce impact on pedestrians during collisions without impeding the ability of occupants to see outside the vehicle.
Innovation Solution
The laminated glass features deformation parts with recesses and fissures on the inner surfaces of the glass plates, designed to initiate cracking from the inside upon impact, ensuring visibility and controlled breakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the laminated glass is made to break easily to reduce impact on pedestrians, then the safety for pedestrians is improved, but the visibility for occupants is impaired
Solution Approach 1:
The patent applies local quality by creating deformation parts (recesses with fissures) only at specific locations on the glass plates, rather than uniformly across the entire surface. These localized deformation parts are positioned to initiate controlled cracking patterns that redirect fracture energy away from the central viewing area, thereby maintaining visibility while achieving pedestrian protection at critical impact zones.
Solution Approach 2:
The patent segments the glass plate surface into multiple deformation parts distributed across the glass surface. Each deformation part acts as an independent crack initiation site, and the segmentation of cracking patterns ensures that fractures are distributed in a controlled manner rather than forming a single large fragment, thus maintaining visibility while reducing impact forces.
2Reliability
If deformation parts are added to the glass plates to control breakage, then the safety performance is improved, but the manufacturing complexity increases
Solution Approach 1:
The patent replaces complex mechanical processing methods with laser processing to create deformation parts. The laser processing method can precisely form recesses and fissures through thermal effects without requiring multiple mechanical steps, tool changes, or complex fixtures, thereby reducing manufacturing complexity while achieving reliable controlled breakage performance.
Solution Approach 2:
The patent utilizes parameter changes in the laser processing system (such as pulse duration, power, and scanning speed) to control the formation of deformation parts with specific geometric characteristics. By adjusting these parameters, the recess depth, diameter, and fissure patterns can be precisely controlled to achieve the desired crack initiation behavior without requiring complex post-processing or additional manufacturing steps.
Data Source
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AI summary
A laminated glass for an automobile, includes, in this order from a vehicle outer side to a vehicle inner side, a first glass plate, an interlayer film, and a second glass plate, wherein plural deformations parts are provided, at an interval in a planar direction, at a vehicle inner side surface of the first glass plate and/or the second glass plate, the deformation part includes a recess and a fissure formed peripherally to the recess, and a value of a ratio of a depth of the recess to a diameter of the recess at the surface is 2 or less.