Gimbaled Vehicle Sensor Damping in Seat Belt Retractor
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Gimbaled vehicle sensors in seat belt retractors often result in nuisance locks due to excessive motion during vehicle deceleration or acceleration, leading to spurious engagements of the seat belt locking mechanism.
Innovation Solution
A seat belt retractor with a gimbaled vehicle sensor that incorporates a force generator, such as a spring steel engagement arm, to create a retarding torque on the gimbal, reducing its motion and the likelihood of nuisance locks by maintaining the basket's orientation and preventing spurious engagements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the gimbal is made freely rotatable to maintain vertical orientation during seat movement, then the basket maintains proper orientation, but the gimbal undergoes excessive motion during vehicle deceleration causing nuisance locks
Solution Approach 1:
A dashpot is introduced as an intermediary damping element between the gimbal and housing. This dashpot provides controlled resistance to gimbal rotation, allowing the basket to maintain vertical orientation during normal seat movement while preventing excessive motion during vehicle deceleration that would cause nuisance locks
Solution Approach 2:
The damping coefficient of the dashpot is specifically tuned to provide appropriate resistance across different motion conditions. By adjusting the dashpot parameters, the system achieves the optimal balance between allowing necessary gimbal rotation for orientation maintenance and restricting excessive motion that leads to spurious engagements
2Object-affected harmful factors
If the force generator applies strong damping force to reduce gimbal motion, then nuisance locks are reduced, but the gimbal motion is overly restricted affecting orientation maintenance
Solution Approach 1:
The dashpot parameters are precisely calibrated to provide velocity-dependent damping. This ensures that during normal seat movement the gimbal can rotate sufficiently to maintain vertical orientation, while during rapid deceleration events the damping force increases to prevent nuisance locks
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 effectively reduces the occurrence of nuisance locks by damping the gimbal's motion relative to the housing, ensuring the seat belt retractor engages only during emergency conditions, thereby enhancing user comfort and reducing unnecessary seat belt activation.
Implementation Method 1
the force generator comprises a length of spring steel with an engagement end that is one of curved or flat
Implementation Method 2
create a retarding torque on the axles or axle to slow or damp the motion of the gimbal relative to the housing
Data Source
Figure 1~3
Figure 4
Figure 5~14
AI summary
A seat belt retractor comprising a gimbaled vehicle sensor (100) having a gimbal (160) rotationally movable relative to a housing (120) fixed to a portion of the retractor, the retractor including a force generator (70) generating a radial force which upon movement of the gimbal creates a tangential torque to slow or damp the motion of the gimbal relative to the housing.