Side Airbag Cover Rupture Control via Segmented Design
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Solution Overview
Problem
Existing side airbag devices face difficulties in properly rupturing the thin portion of the cover during airbag inflation, leading to unpredictable deployment and potential contact between the airbag and cover, which interferes with the proper functioning of the side airbag device, especially as the thin portion becomes longer.
Innovation Solution
A side airbag device design where the thin portion of the outer cover is integrally molded and reinforced with ribs, and the inner cover is made of a soft resin material, allowing the airbag to inflate and rupture the outer cover at a predetermined timing, ensuring proper deployment without compromising the ornamentality or comfort of the vehicle interior.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the thin portion of the cover is made longer to cover more area, then the coverage area is improved, but the reliability of proper rupturing deteriorates
Solution Approach 1:
The cover is divided into two distinct parts: a thin portion for controlled rupturing and a thick portion for structural support and aesthetic purposes. This segmentation allows the thin portion to be optimized for reliable rupture at predetermined timing while the thick portion maintains the necessary coverage area and structural integrity, resolving the contradiction between coverage area and rupturing reliability.
Solution Approach 2:
Different regions of the cover are given different thickness qualities - the thin portion has reduced thickness to facilitate controlled rupturing, while the thick portion maintains sufficient thickness for structural support and aesthetic appearance. This local quality differentiation enables the cover to simultaneously achieve proper rupturing reliability and adequate coverage area.
2Ease of operation
If the thin portion is made thinner to facilitate easier rupturing, then the ease of operation is improved, but the strength of the cover deteriorates
Solution Approach 1:
The cover is segmented into thin and thick portions, allowing the thin portion to be optimized for easy rupturing while the thick portion maintains overall cover strength. This segmentation resolves the contradiction by distributing different functional requirements to different parts of the same component.
Solution Approach 2:
The cover exhibits local quality variation in thickness - thinner at the portion requiring rupturing for ease of operation, and thicker at other portions requiring structural strength. This localized property differentiation enables simultaneous achievement of easy rupturing and adequate cover strength.
3Strength
If the cover is made more robust to prevent unexpected contact, then the strength is improved, but the ease of manufacture deteriorates
Solution Approach 1:
The cover is manufactured as a single integrated component with built-in thickness variation, segmented into thin and thick portions. This approach achieves the desired strength distribution while simplifying manufacture compared to assembling multiple separate components, as the thickness variation can be achieved through standard molding techniques.
Solution Approach 2:
Multiple functions are merged into a single cover component - it provides coverage, structural support through the thick portion, and controlled rupturing through the thin portion. This merging reduces the number of parts and assembly steps, improving ease of manufacture while maintaining the necessary strength characteristics.
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 design ensures accurate and timely deployment of the airbag, preventing unexpected contact between the airbag and cover, enhancing the reliability of the side airbag device while maintaining the aesthetic and tactile integrity of the vehicle's interior.
Implementation Method 1
The thin portion is ruptured by pressure produced during inflation of the airbag to form an opening in the cover
Data Source
AI summary
A device includes an airbag and an outer cover. The airbag is accommodated between a body and a rear seat of a vehicle. The outer cover covers a space defined between the body and the rear seat from the passenger compartment and is exposed to the passenger compartment. When an impact greater than a predetermined level is applied to the vehicle body, a thin portion of the outer cover is ruptured by the pressure from inflation of the airbag. This forms an opening in the outer cover. The airbag is then inflated into the passenger compartment from the opening of the outer cover. The end at the part of the outer cover corresponding to the opening and facing toward the rear seat is entirely formed by the end of the outer cover.