Vehicle Seat Rail Pair with Planar Support Face for Torsional Rigidity
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Solution Overview
Problem
Existing seat rail pairs for vehicle seats lack sufficient stability and loadability, particularly in crash scenarios, due to inadequate design features that limit displacement and absorb loads effectively.
Innovation Solution
A seat rail pair design featuring a lower rail with a C-shaped profile and an upper rail with a U-shaped profile, where roller members are arranged in raceways, with a planar support face on the upper rail's end portions contacting the roller members, enhancing strength, tolerance compensation, and stability by increasing torsional rigidity and transverse and vertical stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If roller members are arranged in raceways between the lower rail and upper rail, then the seat rail pair achieves smooth displacement and load distribution, but the stability and torsional rigidity are insufficient without additional structural features
Solution Approach 1:
The upper rail features a planar support face on its end portions that contacts the roller members, creating a defined geometric relationship between the curved roller paths and the rail structure. This planar face provides a stable reference surface that prevents lateral deviation while allowing smooth rolling motion.
Solution Approach 2:
The C-shaped profile of the lower rail with downwardly bent end portions and the U-shaped profile of the upper rail with upwardly bent end portions create a three-dimensional interlocking structure. This multi-dimensional geometry provides stability in both transverse and vertical directions while accommodating the roller members' movement.
2Manufacturing precision
If the upper rail has upwardly bent end portions guided in the lower rail's external profile portions, then the displacement path is limited and positioning is defined, but the loadability in crash scenarios is insufficient
Solution Approach 1:
The planar support face on the upper rail's end portions provides a large surface area for contact with the roller members, distributing crash loads across multiple contact points rather than concentrating them at single points. This geometric feature enhances the structure's ability to absorb and dissipate impact energy.
Solution Approach 2:
The C-shaped and U-shaped profiles with bent end portions create a three-dimensional load path that distributes forces in multiple directions. The interlocking geometry provides structural reinforcement that enhances loadability during crash scenarios while maintaining precise positioning during normal operation.
3Strength
If the lower rail has a C-shaped profile with downwardly bent end portions and the upper rail has a U-shaped profile with upwardly bent end portions, then the structural strength is improved, but the tolerance compensation capability is limited
Solution Approach 1:
The planar support face on the upper rail provides a forgiving contact surface that can accommodate variations in roller member positioning and rail alignment. This geometric feature compensates for manufacturing tolerances by providing a stable contact interface that maintains proper function even with slight dimensional variations.
Solution Approach 2:
The three-dimensional C-shaped and U-shaped profiles with bent end portions create an interlocking structure that accommodates tolerance variations through its geometric design. The multi-dimensional geometry allows for adjustment and compensation in multiple directions, ensuring proper assembly and function despite manufacturing variations.
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 design achieves high strength and stability by allowing for improved tolerance compensation and load distribution, preventing the upper rail from sliding off during torsion and minimizing deformation under vertical loads, thus enhancing overall stability and loadability during crashes.
Implementation Method 1
roller members are arranged in two lower roller member raceways and two upper roller member raceways between the lower rail and the upper rail
Data Source
AI summary
A seat rail pair for a vehicle seat is disclosed. The seat rail pair may have a lower rail and an upper rail. The upper rail may be moved relative to the lower rail via mutually engaged profiles. The lower rail may have a substantially C-shaped profile and the upper rail may have a substantially U-shaped profile. Roller members may be arranged between the upper rail and the lower rail to facilitate relative movement.