Airbag Vent Flap Tether Actuation for Gas Flow Control
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Solution Overview
Problem
Current airbag vent assemblies do not effectively control the flow of inflation gas during deployment, leading to inefficient gas venting and potential risks for vehicle occupants.
Innovation Solution
An airbag vent assembly featuring a flexible vent flap and tether system, where the vent flap is initially positioned to restrict gas escape and is actuated by a sensor-activated tether to interpose between vent openings, preventing gas escape during deployment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If vent openings are provided in the airbag to vent inflation gas, then gas venting capability is improved, but uncontrolled gas flow may cause harmful effects on occupants
Solution Approach 1:
The vent flap is designed to be movable rather than fixed, allowing it to dynamically adjust its position based on inflation pressure. During deployment, the flap moves to block the vent opening when pressure is high, and opens when pressure decreases, providing dynamic control over gas flow to prevent harmful effects while maintaining venting capability
Solution Approach 2:
The vent flap acts as an intermediary element between the inflation gas and the vent opening. It mediates the gas flow by selectively blocking or allowing passage based on deployment conditions, preventing direct uncontrolled discharge of gas toward occupants while maintaining the venting function
2Ease of operation
If a vent flap is used to control gas flow through vent openings, then gas flow control is improved, but device complexity increases
Solution Approach 1:
The vent flap is designed to automatically respond to inflation pressure changes without external control mechanisms. The high inflation pressure directly moves the flap to the blocked position, and when pressure decreases, the flap returns to its open position, providing self-service gas flow control that avoids additional complex actuation systems
Solution Approach 2:
The vent flap is constructed from flexible material that can deform and move in response to pressure differential. This flexible construction allows for simple, lightweight implementation of the control function without requiring rigid mechanical structures or complex linkages
3Object-affected harmful factors
If the vent flap is positioned to restrict gas escape during deployment, then occupant safety is improved, but gas venting efficiency decreases
Solution Approach 1:
The vent flap operates in a periodic manner during the inflation process: initially blocking the vent opening during the high-pressure deployment phase to protect occupants, then opening during the lower-pressure deflation phase to allow controlled venting. This periodic action resolves the contradiction by providing safety when needed and efficiency when safe
Data Source
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AI summary
An airbag cushion (15) of flexible sheet material has a vent opening (31) therein with a vent cover (40) of flexible sheet material stitched to an interior surface of the airbag cushion aligned with the vent opening in the airbag cushion to form a pocket. A vent flap (32) of flexible sheet material is disposed at least partially within the pocket and inboard of the vent openings in the airbag cushion and vent cover. The vent flap is fixed to at least one tether (33) that extends outboard from the vent flap through an opening in the vent cover to a tether end that is permanently attached to the airbag cushion outboard of the vent cover. A tether extends (17) inboard from vent flap to a tether end that is fixed in a releasable manner to a tether end securing device fixed to a module housing.