Webbing Take-Up Device Restricting Portion Pawl Displacement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing webbing take-up devices face complexity in assembly and inefficiency in suppressing rotation force transmission to the rotation force transmitting member when not required, leading to potential unintended load and vibration issues.
Innovation Solution
A webbing take-up device with a spool, lock section, pawl, and restricting member, where the restricting portion is positioned to prevent displacement of the pawl until the spool is rotated, allowing controlled transmission of rotation force to the rotation force transmitting member only when necessary, featuring engagement tooth portions and a wound section design to prevent unintended engagement and increase size efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a pin and guide hole structure is used to transmit rotation force from the spool to the lock ring, then rotation force transmission is achieved, but the assembly process becomes complex and requires additional processing steps
Solution Approach 1:
The patent merges the pin and guide hole into an integrated structure where the guide groove is directly formed on the lock base rather than being a separate component. This integration eliminates the need for separate pin insertion and guide hole processing steps, thereby reducing assembly complexity while maintaining rotation force transmission functionality.
Solution Approach 2:
The lock base is designed to serve multiple functions: it acts as both the locking mechanism support and the guide structure for the FL pawl. The guide groove formed on the lock base simultaneously provides guidance and structural support, reducing the need for separate guiding components and simplifying the overall assembly.
2Ease of operation
If the spool is allowed to rotate freely to transmit rotation force, then webbing payout is enabled, but unintended load and vibration occur when rotation force transmission is not required
Solution Approach 1:
The patent employs a dynamic locking mechanism where the FL pawl can freely move along the guide groove during normal operation, allowing the spool to rotate without restriction. When locking is required, the mechanism dynamically transitions to engage the lock ring, preventing unintended rotation and eliminating harmful loads and vibrations.
Solution Approach 2:
The FL pawl acts as an intermediary element between the spool and the lock ring. It can selectively engage with the lock ring to transmit or block rotation force as needed, serving as a mediator that controls the transmission path and prevents direct unwanted engagement between the spool and locking structure.
Data Source
AI summary
A webbing take-up device includes a spool taking up webbing worn by an occupant, that is rotated in a pull-out direction by the webbing being pulled-out; a base lock that is provided capable of rotating integrally with the spool and restricts rotation of the spool in the pull-out direction in vehicle-emergency; a pawl that is rotated together with the spool and, by being displaced, engages with a winding ring and transmits rotation force of the spool to the winding ring, and a trigger ring including a restricting portion that is disposed in a restricting position at which displacement of the pawl is restricted in a state prior to the spool being rotated with respect to the base lock, and is disposed in a permitting position at which displacement of the pawl is permitted when the spool has been rotated in the pull-out direction with respect to the base lock.