Active D-Ring Seat Belt Anti-Bunching Lock
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Solution Overview
Problem
Conventional seat belt systems experience bunching of webbing in the D-ring during rapid deceleration events, leading to uneven load distribution and interference with smooth extraction and retraction, due to the D-ring's backward rotation under deceleration forces.
Innovation Solution
An active seat belt system with a controlled locking mechanism, such as a locking pin operated by an electric solenoid, restricts the backward rotation of the D-ring during deceleration events, ensuring even load distribution across the slotted opening and preventing bunching, while allowing free rotation for smooth retraction when the seat belt is unlatched.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the D-ring is allowed to rotate freely to accommodate webbing extraction and retraction, then ease of operation is improved, but webbing bunching occurs during rapid deceleration causing uneven load distribution and interference with smooth extraction
Solution Approach 1:
The D-ring rotation restriction mechanism transitions from a static fixed position to a dynamic state during rapid deceleration. The inertia-sensitive actuator detects deceleration forces and automatically locks the D-ring in its current position, preventing backward rotation that would cause webbing bunching. This dynamic response maintains reliability during crashes while allowing free rotation during normal operation for ease of use.
Solution Approach 2:
The system applies preliminary anti-action by preventing the harmful backward rotation of the D-ring before webbing bunching can occur. The inertia-sensitive actuator locks the D-ring upon detecting deceleration forces, proactively counteracting the tendency of the D-ring to rotate backward under load, thereby maintaining even webbing load distribution throughout the deceleration event.
2Reliability
If a locking mechanism is added to restrict D-ring backward rotation during deceleration, then webbing bunching is prevented and load distribution is improved, but device complexity increases
Solution Approach 1:
The locking mechanism is self-activating through an inertia-sensitive actuator that automatically detects deceleration forces and triggers the lock without requiring external control systems or additional sensors. The mechanism serves itself by using the deceleration force directly to activate the locking action, minimizing added complexity while achieving the reliability improvement of preventing webbing bunching.
3Shape
If the D-ring rotates backward during rapid deceleration, then the leading edge rotates downwards and backwards, but this causes tension forces to concentrate in the leading corner rather than distribute evenly across the slotted opening
Solution Approach 1:
The inertia-sensitive actuator locks the D-ring upon detecting deceleration forces, proactively counteracting the tendency of the D-ring to rotate backward under load, thereby maintaining even webbing load distribution throughout the deceleration event.
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 minimizes webbing bunching and ensures even load distribution across the D-ring, enhancing the seat belt's performance and comfort by preventing backward rotation during deceleration and allowing smooth retraction and extraction.
Implementation Method 1
the locking mechanism comprises a locking pin operated by an electric solenoid which engages the locking pin when signaled by a controller or electrical signal
Implementation Method 2
When the occupant unlatches the seat belt buckle in said embodiment, a spring disengages the locking pin thereby permitting the D-ring to rotate backwards and the webbing to retract smoothly into the retractor mechanism
Implementation Method 3
An inertia sensitive actuator locks the retractors when an impact or rollover event is detected, preventing extraction of webbing
Data Source
AI summary
A motor vehicle seat belt system having an active system for avoiding bunching of webbing in a D-ring during a rapid deceleration event. The system includes a controlled locking mechanism engageable with a rotatably mounted D-ring to restrict backward rotation of the D-ring.