Vehicle Headrest Locking Mechanism Tolerance Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vehicle headrests face challenges in reducing production costs, minimizing disturbing noises, and accommodating large tolerances in their locking mechanisms.
Innovation Solution
The headrest features a vertically adjustable base part with a locking device that includes a slide and guide surfaces, allowing for precise movement and locking in various positions, and a handle articulated via a joint to compensate for tolerances, ensuring smooth operation and noise reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a locking device with slide and guide surfaces is used, then manufacturing precision can be reduced to accommodate large tolerances, but the complexity of the locking mechanism increases
Solution Approach 1:
A slide element is introduced as an intermediary component between the base part and support rod. The slide carries first holding means that interact with second holding means on the support rod, while being guided by guide surfaces on both components. This intermediary slide absorbs dimensional variations and misalignments, allowing large tolerances in the guide surfaces while maintaining reliable locking functionality.
Solution Approach 2:
The locking device is segmented into distinct functional components: the slide element, the first holding means on the slide, and the second holding means on the support rod. This segmentation allows each component to be manufactured independently with relaxed tolerances, while the assembly of these segments creates the complete locking function with inherent tolerance compensation.
2Object-generated harmful factors
If guide surfaces with large contact area are used, then noise is minimized, but the complexity of the guide structure increases
Solution Approach 1:
The guide surfaces on the base part and support rod automatically provide noise reduction functionality through their geometric design. The large contact area of the guide surfaces inherently dampens impact noises during locking and unlocking operations, without requiring additional noise-control components or complex mechanisms. The structure serves its primary guiding function while simultaneously providing noise mitigation.
3Ease of manufacture
If the slide is guided with large play on the support rod, then manufacturing costs are reduced, but the reliability of the locking mechanism deteriorates
Solution Approach 1:
The first holding means on the slide are pre-configured to engage with the second holding means on the support rod before the slide completes its full travel. This preliminary engagement ensures that locking reliability is maintained even when the slide has large play or dimensional variations, as the critical holding means interaction occurs early in the movement sequence, preventing unreliable locking.
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
This design reduces production costs, minimizes noise, and effectively accommodates manufacturing tolerances, providing a reliable and quiet headrest adjustment mechanism.
Implementation Method 1
The guide surfaces form an interference fit, e.g. between the slide and the base part and/or between the slide and the support rod
Implementation Method 2
The web can deform elastically. The escape space can be formed by a cavity. In this way, the slide is guided without play on the support rod and/or on the base part
Data Source
Figure 1a
Figure 1b
Figure 1c
AI summary
The invention relates to a headrest for a seat, in particular for a vehicle seat, with a base part (11) which is mounted on the seat by at least one support rod (12a, 12b) and is displaceable relative to the support rod, with a locking device (16) movable between a locking position and a release position, by means of which the base part can be locked in at least one position relative to the support rod, wherein the locking device has first retaining means (46) which are associated with the base part (11) and has second retaining means (47) which are associated with the support rod (12a, 12b), wherein the first retaining means are formed on a slide (19) which is movably mounted on the base part (11), such that in the locking position the first retaining means and the second retaining means are engaged and in the release position are disengaged.