Vehicle Seat Rail Load Absorption for Reclined Crash Protection
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Solution Overview
Problem
Reclined seating positions in vehicles increase the risk of unfavorable interactions between occupants and restraint systems during accidents, leading to high head accelerations, neck extensions, submarining, and increased spine and pelvis forces.
Innovation Solution
A load absorption device comprising a rail arrangement with an upper and lower rail connected by a strip with a curved portion, allowing for longitudinal displacement of the rails to absorb inertial energy during a crash, thereby reducing forces on the occupant.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a reclined seating position is used, then comfort and relaxation of the occupant is improved, but the risk of unfavorable interactions with restraint systems during accidents increases
Solution Approach 1:
The seat is designed to dynamically change its position during a crash event. The rail arrangement allows the seat to slide forward from a reclined position to a more upright position, adapting to the crash conditions and reducing harmful interactions with restraint systems
Solution Approach 2:
The load absorption device acts as an intermediary mechanism between the seat and the vehicle structure. It controls the seat's movement during a crash, mediating the transition from reclined to forward position while managing the forces involved
2Loss of energy
If the upper rail is allowed to displace longitudinally relative to the lower rail, then inertial energy is absorbed by strip deformation, but the device complexity increases
Solution Approach 1:
The strip is designed as a flexible element with a curved portion that deforms during rail displacement. This flexible component absorbs inertial energy through controlled deformation, providing an effective energy absorption mechanism
Solution Approach 2:
The load absorption device is segmented into distinct functional components: the upper rail, lower rail, and strip with curved portion. This segmentation allows each component to perform its specific function while simplifying the overall design and analysis
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 device effectively absorbs inertial energy by deforming the strip, reducing the risk of submarining and minimizing forces on the spine and pelvis area during a crash.
Implementation Method 1
The curved portion is configured to translate in the same direction as the upper rail during a mutual displacement between the upper rail and the lower rail
Implementation Method 2
The energy is absorbed by causing a deformation of a strip which is arranged in a limited interspace between two parallel rails
Data Source
Figure 1~2
Figure 3~4
Figure 5A~5B
AI summary
A load absorption device to be used with a vehicle seat is provided. The device comprises a rail arrangement comprising an upper rail (1) configured to be connected to a lower side of the vehicle seat and a lower rail (2) configured to be fixedly connected to a top surface of a vehicle floor. The upper and the lower rails (1, 2) are slidingly connected to each other to allow a longitudinal mutual displacement between the upper rail (1) and the lower rail (2). The device further comprises a strip (3) having first leg (15A) having a first end (16A), a second leg (15B) having a second end (16B), and a curved portion (15C) intermediate the first and second legs. The first end (16A) is fixedly connected to the lower rail (2) and the second end (16B) is fixedly connected to the upper rail (1). The curved portion (15C) is configured to translate in the same direction as the upper rail (1) during a mutual displacement between the upper rail (1) and the lower rail (2). Further a vehicle occupant protection system (1000) and a method of operating such system is provided.