Vehicle Seat Headrest Locking Mechanism for Crash-Driven Extension
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Solution Overview
Problem
Existing headrest modules in motor vehicles do not effectively minimize the distance between the vehicle occupant's head and the headrest during a crash, as they rely on external mechanisms that may not engage promptly or consistently, potentially leading to inadequate protection.
Innovation Solution
A headrest module with a fixing mechanism featuring a first fixing element with teeth and a second movable fixing element that engages between adjacent teeth, allowing the headrest to extend under force and retract only upon activation of a release mechanism, ensuring optimal positioning during crashes without external assistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a separate locking device with a movement strip and pin is used to lock the headrest at a desired distance, then the headrest can be positioned at various distances from the base component, but the locking device may not engage promptly or consistently during a crash, potentially leading to inadequate protection
Solution Approach 1:
The fixing mechanism automatically engages without external assistance during a crash. The mass inertia of the headrest causes it to extend and engage the teeth of the fixing mechanism autonomously, eliminating the need for external locking devices or mechanisms to trigger the engagement action.
Solution Approach 2:
The invention removes the separate locking device (movement strip with slot and pin) from the system and replaces it with an integrated fixing mechanism that combines positioning and locking functions into a single autonomous system, simplifying the structure and improving reliability.
2Reliability
If the headrest is movable in the vehicle longitudinal direction to minimize distance during crashes, then protection is improved, but the headrest may retract before optimal positioning is achieved without a release mechanism
Solution Approach 1:
The invention combines the fixing mechanism and release mechanism into an integrated system where the second fixing element serves dual purposes: locking the headrest in position during normal operation and being movable to enable retraction when the release mechanism is activated. This merging reduces the number of separate components while maintaining both functions.
3Speed
If external mechanisms are used to extend the headrest during crashes, then the headrest can be moved forward, but the distance minimization may not be achieved promptly or consistently
Solution Approach 1:
The headrest extension during a crash is achieved through the mass inertia of the headrest itself, which autonomously overcomes the engagement force of the fixing mechanism's teeth. This self-service approach eliminates external mechanisms while achieving rapid extension driven by the physical principles of the crash event.
Solution Approach 2:
The invention converts the harmful force of the crash (mass inertia of the headrest moving forward) into a beneficial action that automatically extends the headrest to the optimal position. The crash force itself becomes the driving mechanism, eliminating the need for separate actuators or external systems.
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 headrest module provides enhanced protection by automatically extending under mass inertia during crashes and preventing retraction until the release mechanism is actuated, maintaining a minimized distance between the occupant's head and the headrest, thus offering improved safety without the need for external mechanisms.
Implementation Method 1
a second fixing element (7) which can be moved towards the first fixing element (5) for engagement between adjacent teeth (6)
Implementation Method 2
Contact faces of the two fixing elements are configured such that an extension of the headrest is possible under the action of a force on the headrest in an extension direction
Implementation Method 3
a movement of the headrest in a retraction direction is possible under action of a release mechanism of the headrest module configured to move the second fixing element out of the region between the teeth of the first fixing element
Implementation Method 4
an extension of the headrest is possible under the action of a force on the headrest in an extension direction
Data Source
AI summary
A headrest module for a motor vehicle seat includes a base component and a headrest mounted in the base component. The headrest is configured to be guided in a vehicle longitudinal direction so as to be extendable and retractable relative to the base component. The headrest further includes a fixing mechanism having a first fixing element with teeth and a second fixing element configured to be moved towards the first fixing element for engagement between adjacent teeth. Contact faces of the two fixing elements are configured such that an extension of the headrest is possible under the action of a force on the headrest in an extension direction. A movement of the headrest in a retraction direction is possible under action of a release mechanism of the headrest module configured to move the second fixing element out of the region between the teeth of the first fixing element.