Vehicle Seat Latch Shock Absorbing Member Noise Suppression
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Solution Overview
Problem
Existing vehicle seat reclining devices generate undesirable rattling noise due to vibrations, and reducing clearance between the slider hole and latch projection to minimize noise can lead to engagement issues, increasing production costs and complexity.
Innovation Solution
Incorporating shock absorbing members between the slider hole and latch projection to absorb forces caused by vibrations, allowing for increased clearance without compromising smooth engagement and reducing noise, while maintaining structural integrity and cost-effectiveness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a clearance is provided between the latch projection and slider hole to enable smooth engagement, then the latch projection can easily slide within the slider hole, but the slider reciprocally shakes relative to the rail due to vibrations, causing rattling noise
Solution Approach 1:
A cushioning member is introduced as an intermediary element between the latch projection and the slider hole. This cushioning member absorbs vibrations and prevents direct contact between the latch projection and slider hole during normal operation, thereby eliminating rattling noise while still allowing smooth engagement when needed.
Solution Approach 2:
The cushioning member is pre-installed in the slider hole to provide advance protection against vibrations. By having the cushioning element in place before vibrations occur, the system prevents the transmission of vibrational forces that would cause the latch projection to shake and generate noise.
2Object-generated harmful factors
If the clearance between the slider hole and latch projection is reduced to minimize noise, then rattling noise is suppressed, but the latch projection may be caught on or blocked by the slider hole, impairing smooth engagement
Solution Approach 1:
The cushioning member serves as a mediator that fills the clearance between the latch projection and slider hole. It maintains a small effective gap that prevents noise-generating contact while being compressible enough to allow the latch projection to pass through smoothly during engagement.
Solution Approach 2:
The cushioning member changes its physical parameters (compression, expansion) dynamically. During normal operation, it maintains a compact form to minimize clearance and prevent noise. During engagement, it compresses to allow the latch projection to pass through, then expands to maintain the noise-preventing clearance.
3Object-generated harmful factors
If dimensional tolerance control during manufacturing of the clearance is implemented to reduce noise, then rattling noise is minimized, but production time increases and production costs sharply increase
Solution Approach 1:
The noise control function is extracted from the dimensional tolerance requirements and transferred to a separate cushioning member component. This allows the main slider and latch projection to be manufactured with standard tolerances, while the cushioning member (a simple elastic element) handles the noise suppression function.
Solution Approach 2:
The cushioning member is implemented as a simple, inexpensive elastic element (such as a rubber or foam component) that can be easily manufactured and replaced if needed. This replaces the need for expensive precision machining and tight tolerance control.
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 suppresses rattling noise and ensures smooth engagement of the latch projection into latch holes at a lower cost, with improved durability and simplified manufacturing processes.
Implementation Method 1
a shock absorbing member provided between a first inner surface of the slider hole and a second inner surface of the slider hole in a direction in which the slider hole penetrates the slider, the shock absorbing member being resiliently deformed between the latch projection and the first inner surface of the slider hole or between the latch projection and the second inner surface of the slider hole
Data Source
AI summary
A latch mechanism of a vehicle seat reclining device includes a plurality of latch holes formed in a rail along a central axial line, a slider hole penetrating through a slider so as to face the respective latch holes, a support portion provided on the slider, and a movable portion displaceably supported by the support portion and having a latch projection that is engageable with the respective latch holes while passing through the slider hole. A clearance is defined in the direction of the central axial line between the slider hole and the latch projection. One or more shock absorbing members is (are) provided on opposing first and second inner surfaces of the slider hole and abut against the latch projection while being resiliently deformed to suppress the generation of undesirable rattling noise in case a force causes the latch projection to oscillate within the engaged latch hole.