Rotary Connector Abnormality Detection Circuit for FFC Break Monitoring
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional rotary connector devices in vehicles face issues with break detection accuracy and reliability due to excessive rotation, leading to potential failures in the flexible flat cables, especially at the width direction end portions, and lack of a dedicated circuit for verifying breaks, which can result in safety concerns and unreliable connections.
Innovation Solution
The implementation of an abnormality detection circuit within the rotary connector device, utilizing conductors and busbars in the first flexible flat cable to form a closed circuit for detecting breaks, with busbars connected to both ends of the cable to ensure high accuracy and reliability, and providing additional FFCs with varying lengths to distribute stress and facilitate early detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the FFC is installed with sufficient length to accommodate multiple rotations, then the steering wheel can rotate clockwise or counterclockwise from neutral position, but excessive rotation may occur causing break of the FFC or connecting portion
Solution Approach 1:
The patent applies preliminary action by providing an abnormality detection circuit that monitors the FFC connection status before excessive rotation causes actual damage. The detection circuit enables early warning when the FFC approaches its rotation limit or shows signs of stress, allowing preventive measures to be taken before the connector breaks or the connection fails.
2Device complexity
If no dedicated break detection circuit is provided, then the device structure remains simple, but breaks in circuits can only be verified when functional failure occurs
Solution Approach 1:
The patent implements feedback by incorporating an abnormality detection circuit that continuously monitors the electrical continuity of the FFC and provides real-time feedback about connection status. The detection circuit uses the existing conductors and busbars to sense breaks or abnormalities and triggers a warning signal, enabling precise detection of connection issues before they lead to functional failure.
3Force
If the FFC width direction end portion is subjected to external force during excessive rotation, then stress concentrates at the end portion, but break detection becomes more difficult
Solution Approach 1:
The patent applies universality by designing the abnormality detection circuit to monitor all conductors in the FFC simultaneously using the existing busbar structure. The detection circuit can identify breaks in any conductor regardless of location or stress concentration point, making the detection system universally applicable to all circuit paths without requiring additional sensors or complex monitoring mechanisms.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Provided is a connection structure body capable of detecting a break with ease and high accuracy and achieving high connection reliability and safety. A connection structure body 2 includes a first FFC (41), a stator side primary molding body (50), and a rotator side primary molding body (60) which are attached to both end portions (41A) and (41B) of the first FFC respectively and are able to make an electrical connection between the first FFC and the outside. The rotator side primary molding body 60 includes busbars (61-1a), (61-1b), (61-1c), and (61-1d) arranged in parallel to each other corresponding to busbars (51-la to 51-1d), a conductive portion (61-2) that electrically connects a pair of busbars (61-1a) and (61-1d) positioned on both ends respectively in the alignment direction of the busbars (61-1a to 61-1d), and a busbar case (62) for holding the busbars (61-1a to 61-1d) in such a manner that the busbars (61-1a to 61-1d) are partly exposed. The busbars (61-1a) and (61-1d) and the conductive portion (61-2) constitute an abnormality detection circuit by forming a part of a closed circuit.