Active Air Bag Vent With Inverting Tether Mechanism
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Solution Overview
Problem
Existing air bag systems lack efficient mechanisms to vent inflation fluid, which can impact ride-down characteristics and occupant protection, particularly in response to varying vehicle and occupant conditions.
Innovation Solution
The development of an adaptive venting system within air bags, utilizing a tether mechanism that adjusts between open and closed conditions based on vehicle and occupant conditions, allowing for controlled release or retention of inflation fluid through conical, tubular, or panel-based configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If the air bag includes vents to release inflation fluid, then ride-down characteristics are improved, but the air bag cannot maintain inflation pressure under all conditions
Solution Approach 1:
The vent system transitions from a static design to a dynamic one where the vent opening/closing is controlled based on real-time conditions. The controller actively manages the vent mechanism to open or close depending on whether inflation fluid release is needed, allowing the system to adapt its behavior to different operational phases and conditions.
Solution Approach 2:
The system changes the state parameter of the vent (open/closed) based on monitored conditions such as inflation pressure, vehicle deceleration rate, and occupant position. This parameter change allows the air bag to maintain pressure when needed and release pressure to improve ride-down characteristics when appropriate.
2Ease of operation
If vents are always open to release inflation fluid, then ride-down characteristics improve, but inflation pressure cannot be maintained for adequate protection
Solution Approach 1:
The controller receives feedback from sensors monitoring inflation pressure, vehicle conditions, and occupant position. Based on this feedback, the controller determines whether to open or close the vent mechanism, creating a closed-loop control system that maintains inflation pressure when needed while enabling pressure release for improved ride-down characteristics when appropriate.
Solution Approach 2:
The vent mechanism is designed to be dynamically controllable rather than fixed. The controller can switch the vent between open and closed states based on real-time conditions, allowing the system to maintain strength when protection is critical and enable ease of operation (ride-down control) when the threat has passed or pressure needs reduction.
3Device complexity
If a tether mechanism is used to control vent opening, then vent control is simplified, but the system requires additional components
Solution Approach 1:
The tether mechanism is designed to automatically open the vent based on physical conditions such as air bag expansion force or vehicle deceleration, without requiring complex electronic actuators. The tether's anchorage points and mechanical configuration allow it to respond autonomously to the inflation process and external forces, simplifying the control mechanism while maintaining reliability through passive mechanical action.
Solution Approach 2:
The tether acts as an intermediary mechanical element that translates physical conditions (inflation pressure, vehicle motion) into vent opening/closing action. This mechanical intermediary provides a reliable connection between the air bag system and the vent mechanism, ensuring dependable actuation without requiring complex electronic control systems.
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 system effectively vents inflation fluid when needed, enhancing ride-down characteristics and occupant protection by responding to specific vehicle and occupant conditions, thereby improving the performance and safety of air bag deployment.
Implementation Method 1
A vent for blocking inflation fluid from venting through the passage includes a sidewall that extends through the panel and defines a passage
Implementation Method 2
A tether has a first end portion connected to the first portion of the vent and a second end portion releasably anchored in the vehicle
Data Source
AI summary
An apparatus (10) for helping to protect an occupant (20) of a vehicle (12) includes an inflatable vehicle occupant protection device (14) comprising a panel (114) that at least partially defines an inflatable volume (54) of the protection device. A vent (100) includes a sidewall that extends through the panel (114) and defines a passage (134) for venting inflation fluid from the inflatable volume (54). The vent (100) includes a first portion (102) extendable inside the inflatable volume (54) and an opposite second portion (104) extendable outside the inflatable volume. The vent (100) has an open condition in which the first portion (102) is maintained inside the inflatable volume (54) and thereby permits venting of inflation fluid through the passage (134), and a closed condition in which the first portion (102) is inverted and positioned in the second portion (104) thereby blocking inflation fluid from venting through the passage (134).