Air Bag Variable Venting Tether Mechanism
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Solution Overview
Problem
Existing vehicle air bag systems face challenges in adapting to varying occupant sizes, seat positions, and vehicle conditions during deployment, leading to inconsistent protection and potential strikethrough issues due to the complexity of determining these factors in real-time.
Innovation Solution
An adaptive air bag system with a tether and guide configuration that throttles the venting mechanism based on occupant penetration, allowing for passive adjustment of inflation and deployment in response to vehicle and occupant conditions, ensuring effective cushioning and ride-down characteristics without the need for active sensors or actuators.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a fixed vent opening is used in the air bag, then the manufacturing is simple, but the protection effectiveness varies for different occupant sizes and conditions
Solution Approach 1:
The vent opening is made dynamically adjustable through a tether mechanism that changes the vent opening area based on air bag inflation pressure and occupant penetration depth. The tether connects the vent to the air bag, and as the air bag inflates and the occupant penetrates, the tether adjusts the vent opening from fully open to progressively more restricted, providing adaptive protection without complex sensors or actuators.
2Adaptability or versatility
If active sensors and actuators are used to adjust venting, then the adaptability to occupant conditions improves, but the device complexity and cost increase
Solution Approach 1:
The venting system is self-regulating through the tether mechanism that automatically adjusts the vent opening based on physical interactions during deployment. The tether uses the natural forces of air bag inflation and occupant penetration to control vent opening area, eliminating the need for external sensors, actuators, or control systems while maintaining adaptive protection.
Solution Approach 2:
The tether mechanism provides passive feedback control where the vent opening area is continuously adjusted based on the state of air bag inflation and occupant penetration. As the occupant penetrates deeper into the air bag, the tether progressively restricts the vent opening, creating a feedback loop that adapts protection levels to actual deployment conditions without requiring active sensing.
3Speed
If the vent remains fully open during deployment, then the inflation speed is fast, but the ride-down effect and protection quality deteriorate
Solution Approach 1:
The vent opening undergoes periodic modulation during the deployment sequence. Initially, the vent is fully open to enable rapid inflation. As deployment progresses and the occupant penetrates the air bag, the tether progressively restricts the vent opening in stages, creating a time-varying venting action that provides both rapid initial inflation and controlled ride-down effect for improved protection quality.
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 system provides tailored protection by throttling the venting mechanism in response to occupant penetration, enhancing the air bag's ability to absorb impact forces and prevent strikethrough, thereby improving occupant safety across a range of conditions.
Implementation Method 1
A tether has a first connection with the vent and a second connection with the protection device. The second connection of the tether is positioned on the protection device such that deployment of the protection device throttles the vent toward an actuated condition, and occupant penetration into the protection device throttles the vent toward a non-actuated condition.
Data Source
AI summary
An apparatus (10) for helping to protect an occupant (20) of a vehicle (12) comprises an inflatable vehicle occupant protection device (14) inflatable between a vehicle surface (36) and the vehicle occupant. A vent (160) releases inflation fluid from the protection device (14). The vent (160) includes a vent opening with a flow area that can be adjusted to throttle inflation fluid flow through the vent. A tether (150) has a first connection with the vent (160) and a second connection with the protection device (14). Tension on the tether (150) throttles the vent (160). The second connection of the tether is positioned on the protection device (14) such that deployment of the protection device throttles the vent (160) toward an actuated condition, and occupant (20) penetration into the protection device throttles the vent toward a non-actuated condition.