Airbag Tether Length Adjustment for Variable Protrusion
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Solution Overview
Problem
Existing occupant protection devices face challenges in adjusting the amount of airbag protrusion without increasing the airbag volume, which requires corresponding inflator output or base fabric capacity adjustments.
Innovation Solution
An occupant protection device with an airbag that can be inflated in two modes (small and large protrusion amounts) using a tether connected to a length adjustment unit, allowing the tether connection distance to be adjusted between two modes, thereby controlling the shape of the tubular inflation portions to maintain volume consistency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the amount of protrusion of the airbag is increased to protect different occupant sizes, then the adaptability is improved, but the volume of the airbag increases requiring larger inflator output or base fabric capacity
Solution Approach 1:
The patent applies dynamics by making the tether length adjustable between two modes (short and long) depending on occupant size detection. The airbag system transitions between different deployment configurations dynamically, allowing the same airbag to adapt to different occupant sizes without changing its physical volume or requiring different inflators.
Solution Approach 2:
The patent changes the parameter of tether length to control the deployment mode. By adjusting the tether length between two specific modes, the airbag can protect different occupant sizes (small occupant head protection vs. large occupant abdomen protection) while maintaining consistent airbag volume and using the same inflator capacity.
2Reliability
If the airbag volume is increased to accommodate larger protrusion amounts, then the protection capability for large occupants is improved, but the inflator output requirement increases
Solution Approach 1:
The system dynamically adjusts tether length based on detected occupant size, allowing the same airbag volume to serve different protection needs. Small occupants receive head protection with shorter tether, while large occupants receive abdomen protection with longer tether, eliminating the need to increase airbag volume or inflator output for different occupant types.
Solution Approach 2:
The airbag system achieves multi-functionality by using a single airbag volume and inflator configuration to protect both small and large occupants effectively. The universal design uses tether length adjustment rather than different airbag sizes, allowing one system to fulfill multiple protection functions.
3Strength
If the airbag base fabric capacity is increased to support larger volume, then the structural strength is improved, but the manufacturing cost and material usage increase
Solution Approach 1:
The patent uses dynamic tether length adjustment rather than increasing base fabric capacity. The same base fabric supports both short and long deployment modes, eliminating the need to manufacture larger or stronger airbags for different occupant sizes.
Solution Approach 2:
The patent changes the tether length parameter to achieve different protection modes without changing the base fabric capacity. This allows the airbag to maintain consistent material usage and structural strength while adapting to different occupant sizes through configuration changes rather than material increases.
Data Source
AI summary
An occupant protection device includes an airbag which is deployed and inflated with an amount of protrusion from a storage position to a rear side in an inflation completed state in a large protrusion amount mode and a small protrusion amount mode, and the airbag includes a bag body and a tether. The tether is connected to a length adjustment unit. The bag body has a tubular inflation portion curved in a substantially U shape from the storage position toward the tether connection portion. A shape of the bag body in the large protrusion amount mode is defined such that the tether connection portion is further moved rearward with respect to the inlet port on the inner peripheral surface side, as compared with the case of the small protrusion amount mode.