Tether Actuation Unit Curved Sidewalls Airbag Deployment
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Solution Overview
Problem
Existing airbag deployment systems lack the ability to dynamically control deployment based on vehicle and occupant conditions, such as seat position and type of collision, which can result in inadequate protection during varied crash scenarios.
Innovation Solution
A tether actuation unit that secures and releases a tether connected to the airbag module, allowing for controlled deployment by selectively actuating the tether to manage airbag venting or chamber deployment based on sensed conditions, using a pyrotechnic actuator and a tether channel with curved sidewalls to prevent stress risers and accommodate various angles of tension.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the airbag deployment system uses a fixed tether connection, then the structure is simple and reliable, but it cannot adapt to different occupant conditions and collision types
Solution Approach 1:
The tether connection is changed from a fixed static state to a dynamically controllable state. The tether actuation unit can selectively release the tether based on sensed conditions (occupant size, seat position, collision type), allowing the system to adapt between different deployment scenarios without requiring multiple physical tether configurations.
Solution Approach 2:
The system changes the state parameter of the tether connection from locked to released based on detected conditions. By monitoring parameters such as seat position, occupant presence, and collision characteristics, the control system adjusts the tether release state to optimize airbag deployment for different scenarios.
2Reliability
If the tether channel has tight sidewalls to prevent tether movement, then the tether is securely constrained, but stress risers may damage the tether
Solution Approach 1:
The tether channel incorporates curved sidewalls instead of sharp corners or tight straight constraints. This curvature design allows the tether to follow a smooth path, distributing mechanical stresses along the tether length and preventing localized stress concentration that would lead to tether failure.
Solution Approach 2:
The tether channel design accommodates the flexible nature of the tether by providing a contoured passage that matches the tether's natural bending profile, allowing the tether to flex smoothly through the channel without sharp bends that would create stress risers.
3Adaptability or versatility
If the tether channel accommodates various angles of tension, then the system is more versatile, but the actuator may experience damaging non-orthogonal forces
Solution Approach 1:
The curved sidewalls of the tether channel guide the tether to apply forces primarily in the orthogonal direction to the actuator, even when the tether enters at various angles. The curvature geometry transforms angular variations into predominantly axial loading on the actuator, protecting it from damaging lateral or non-orthogonal forces.
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
Enables adaptive airbag deployment tailored to occupant size and collision type, enhancing occupant protection by ensuring appropriate deployment dynamics and preventing tether damage through controlled tension management.
Implementation Method 1
using a pyrotechnic actuator and a tether channel with curved sidewalls to prevent stress risers and accommodate various angles of tension
Data Source
AI summary
A tether actuation unit includes an actuator configured to form a connection with a tether that is releasable in response to actuation of the actuator, and a housing configured to receive the actuator. The housing includes a tether channel configured to allow the tether to extend therethrough. The tether channel includes sidewalls configured to receive and engage the tether along a portion of its length when the tether extends at an angle from the housing. The sidewalls of the tether channel are configured to limit movement of the tether in response to airbag deployment in order to limit tension applied to the actuator by the tether to a predetermined range of non-orthogonal directions with respect to a central axis of the actuator.