Seat Belt Retractor Ring Structure for Stable Energy Absorption
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Solution Overview
Problem
Existing seat belt retractors face challenges in stabilizing impact energy absorption and reducing the axial dimension of the winding drum, leading to potential instability in webbing pull-out loads and increased device size.
Innovation Solution
A seat belt retractor design that incorporates a stopper member, an impact energy absorbing wire, and a ring configured for relative rotation, allowing the impact energy absorbing wire to be wound around the ring, thereby stabilizing impact energy absorption and reducing the axial dimension of the winding drum.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the impact energy absorbing wire is wound around the locking base, then the impact energy absorption is stable, but the axial dimension of the winding drum increases
Solution Approach 1:
A ring is introduced as an intermediary component between the locking base and the impact energy absorbing wire. The ring serves as a dedicated winding surface for the wire, allowing it to be wound around the ring rather than directly around the locking base. This intermediary structure enables the wire to maintain its winding configuration for stable energy absorption while the ring itself is designed to fit within the axial space constraints of the winding drum, thus resolving the contradiction between absorption stability and compact dimensions.
2Device complexity
If the stopper member is positioned radially outside the ring, then the structure is simpler, but the axial dimension increases
Solution Approach 1:
The stopper member is repositioned from a radial arrangement (outside the ring) to an axial arrangement (inside the ring). By changing the spatial dimension in which the stopper member is positioned, the design achieves compact axial dimensions while maintaining structural functionality. The stopper member remains radially inside the ring but is axially positioned to engage with the winding drum, effectively using dimensional reconfiguration to resolve the space constraint.
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 stable absorption of impact energy while reducing the axial size of the seat belt retractor, enhancing its compactness and operational efficiency.
Implementation Method 1
the impact energy absorbing wire being configured to be pulled out from the opening while being plastically deformed in a case where the winding drum and the locking base are relatively rotated, so as to absorb the impact energy
Implementation Method 2
The torsion bar 130 is configured to absorb impact energy by plastic deformation caused by twisting in that time
Data Source
AI summary
A seat belt retractor includes a housing including a pair of side walls facing each other, a winding drum configured to wind up a webbing, a locking base being prevented from being rotated in the pull-out direction, in an emergency of a vehicle, an impact energy absorbing member connecting the winding drum and the locking base so as to be integrally rotatable in a normal state, an impact energy absorbing wire housed in a slot provided in the winding drum so as to form an opening in the first end surface of the winding drum, a ring provided integrally with or separately from the locking base, and a stopper member being configured to define an allowable amount of relative rotation between the winding drum and the locking base in a case where the impact energy absorbing member absorbs the impact energy.