Seatbelt Guide Reduces Pretensioner Width via Webbing Folding
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Solution Overview
Problem
Conventional seatbelt pretensioners, such as pyrotechnic linear pretensioners, face challenges in reducing packaging size and mass while maintaining effective restraint performance, which is essential for enhancing occupant safety in vehicle crashes.
Innovation Solution
A seatbelt guide with a flattened funnel shape and a fin structure that reduces the seatbelt width by folding its lateral sides under the central portion, allowing the pretensioner to be compactly designed and reducing overall packaging size without compromising restraint effectiveness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the pretensioner is designed with conventional seatbelt routing, then the seatbelt can effectively restrain the occupant, but the packaging width and mass of the pretensioner increase
Solution Approach 1:
The patent applies dimensional change by routing the seatbelt through a three-dimensional path involving folding the lateral sides under the central portion, rather than a simple linear path. This creates a compact routing configuration that reduces the packaging width required while maintaining the belt's restraining function.
Solution Approach 2:
The patent implements nesting by folding the lateral sides of the seatbelt under the central portion, creating a nested configuration where the belt layers are compacted within a smaller spatial envelope. This allows the same restraining function to be achieved in a reduced packaging width.
2Force
If the piston stroke is increased to improve restraint performance, then the pretensioning force increases, but the packaging length of the pretensioner increases
Solution Approach 1:
The patent applies dimensional change by routing the seatbelt through a three-dimensional path involving folding the lateral sides under the central portion, rather than a simple linear path. This creates a compact routing configuration that reduces the packaging width required while maintaining the belt's restraining function.
Solution Approach 2:
The patent implements nesting by folding the lateral sides of the seatbelt under the central portion, creating a nested configuration where the belt layers are compacted within a smaller spatial envelope. This allows the same restraining function to be achieved in a reduced packaging width.
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 solution enables a reduced width and packaging size of the pretensioner while maintaining the ability to induce significant tension in the seatbelt, thereby enhancing occupant restraint during crashes and aligning with the goals of reducing component mass and cost.
Implementation Method 1
When a collision occurs, a pyrotechnic charge in the PLP is fired, producing an expanding gas that pressurizes a gas chamber. This pressure forces a piston to move.
Data Source
AI summary
A guide that can be included as part of a pretensioner for a motor vehicle belt restraint system. The pretensioner includes a frame having walls that define an interior compartment. Located within the interior compartment is a piston assembly having a gas generator in communication with a piston. The gas generator creates an expanding gas that causes movement of the piston and applies tension to a seatbelt of the belt restraint system. The guide includes an opening through which the seatbelt passes and that causes the seatbelt to form a reduced width configuration upon exiting the guide.