Vehicle Seat Longitudinal Adjuster Crash Force Distribution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing longitudinal adjusters for vehicle seats lack sufficient strength during crashes, as the lower and upper locking areas are normally spaced and fail to effectively distribute crash forces into the vehicle structure.
Innovation Solution
A longitudinal adjuster comprising a pair of slidable seat rails with a first staple element and a second clamp member that engage upon a predetermined force, featuring a connecting portion attachable to a rearward surface of the seat frame, allowing vertical forces to be directed into a reinforcing profile, thereby enhancing the adjuster's strength during crashes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the lower and upper locking areas are normally spaced apart, then the longitudinal adjuster allows normal movement and adjustment, but the strength and load distribution during crashes is insufficient
Solution Approach 1:
The connecting portion is divided into multiple functional segments: a first connecting section that attaches to the seat frame side part, a second connecting section that attaches to the reinforcing profile, and an intermediate section that provides structural continuity. This segmentation allows forces to be distributed to multiple attachment points while maintaining structural integrity during crashes.
Solution Approach 2:
The connecting portion extends in multiple spatial dimensions, connecting the seat frame side part to the reinforcing profile through both longitudinal and transverse pathways. This multi-dimensional force distribution enables crash forces to be redirected into the vehicle structure along multiple vectors, significantly enhancing load-bearing capacity without requiring a complete structural redesign.
2Reliability
If the first staple element and second clamp member are engaged during normal operation, then the rail pair is locked, but the longitudinal adjuster cannot be adjusted
Solution Approach 1:
The system transitions between two dynamic states: during normal operation, the first staple element and second clamp member are disengaged to allow rail adjustment; during crashes or when locked, they engage to provide secure positioning. This dynamic engagement mechanism maintains both adjustability and locking reliability without requiring permanent fixation.
Solution Approach 2:
The connecting portion is pre-configured with attachment points and geometric features that enable automatic engagement of the staple element and clamp member under crash forces. This preliminary configuration ensures that when a crash occurs, the components engage in the correct sequence and position to distribute forces effectively, without requiring active control or additional actuators.
3Force
If the connecting portion is rigidly connected, then force transmission is maximized, but the adjuster cannot accommodate normal movement
Solution Approach 1:
The connecting portion exhibits different mechanical properties in different regions: the first and second connecting sections provide rigid force transmission pathways to attachment points, while the intermediate section and overall geometry allow controlled deformation and movement. This local differentiation enables simultaneous force transmission and movement accommodation.
Solution Approach 2:
The connecting portion's effective stiffness changes based on operational conditions. During normal adjustment, the geometry and material properties allow greater flexibility and movement range. During crashes, the same structure transitions to a stiffer state where force transmission is maximized, effectively changing its mechanical parameters in response to applied loads without requiring active control.
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
The invention relates to a longitudinal adjuster (10) for a vehicle seat (1), in particular a motor-vehicle seat, comprising at least one rail pair (12), which is formed from a first seat rail (14), in particular for connecting to a seat frame side part (6), and a second seat rail (16), in particular for connecting to a vehicle structure, wherein the seat rails (14, 16) of the rail pair (12) can be slid relative to each other in the longitudinal direction (x) and engage around each other, wherein a first clamping element (20) is fastened to the first seat rail (14) and a second clamping element (22) is fastened to the second seat rail (16), wherein the first clamping element (20) and the second clamping element (22) are usually spaced apart from each other and hook together, in particular engage with each other, in response to a defined application of force, for example in the event of a crash, wherein the first clamping element (20) has a connection section (24), which can be connected to a surface (8) of a seat frame side part (6) directed toward the rear. The invention further relates to a vehicle seat (1) having such a longitudinal adjuster (10), wherein the vehicle seat (1) has a seat frame side part (6), which is connected to a first seat rail (4).