Vehicle seat structure
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Solution Overview
Problem
Conventional vehicle seat designs fail to adequately reduce occupant incongruity during vehicle acceleration while maintaining holdability, as they struggle to suppress backward inclination of the upper body and head, leading to discomfort and impaired steering operations.
Innovation Solution
A vehicle seat structure with a backward movement adjustment mechanism, featuring support sections with varying spring constants, specifically designed to individually adjust the backward movement of skeletal parts, including a head inclination suppressing function and upper arm support, aligning with the physiological lordosis to maintain spinal curve and enhance holdability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the spring constant of the seat back is lowered to allow backward inclination of the upper body during acceleration, then the occupant's head backward inclination is reduced, but the holdability of the seat deteriorates
Solution Approach 1:
The seat back is divided into multiple support sections (upper thoracic support section and lower thoracic support section) with different spring constants. The upper thoracic support section has a lower spring constant to allow controlled backward movement and reduce head inclination, while the lower thoracic support section has a higher spring constant to maintain holdability and support the occupant's weight effectively.
Solution Approach 2:
Different regions of the seat back are assigned different mechanical properties (spring constants) according to their specific functional requirements. The upper portion uses a softer spring constant for comfort and head inclination reduction, while the lower portion uses a stiffer spring constant for stability and holdability, creating a non-uniform local quality distribution.
2Stability of the object's composition
If the seat back is formed to align with the physiological lordosis, then the spinal curve can be maintained during steady traveling, but the occupant may feel incongruity during acceleration traveling
Solution Approach 1:
The seat back transitions from a static, rigid structure aligned with physiological lordosis to a dynamic structure with multiple support sections having different spring constants. This allows the seat back to adapt its support characteristics based on vehicle acceleration conditions, maintaining spinal alignment during steady travel while accommodating head backward inclination during acceleration to prevent occupant incongruity.
Solution Approach 2:
The mechanical parameters (spring constants) of different support sections are specifically designed to change the overall support characteristics of the seat back. By adjusting the spring constants of individual sections rather than the entire seat back uniformly, the system can maintain spinal curve alignment under normal conditions while allowing controlled deviations during acceleration to eliminate occupant discomfort.
3Object-affected harmful factors
If the lower thoracic support section is configured to displace backward greatly during acceleration, then the upper thoracic spine is inclined forward to suppress head backward inclination, but the structure becomes more complex
Solution Approach 1:
The seat back is segmented into multiple independent support sections (upper thoracic support section and lower thoracic support section) that can move relative to each other. This segmentation allows the lower thoracic support section to displace backward independently during acceleration, which in turn inclines the upper thoracic spine forward to suppress head backward inclination, while keeping each segment's structure relatively simple.
Solution Approach 2:
Multiple support sections with different spring constants are combined within a single seat back structure to achieve the desired differential movement. By merging these sections into one integrated assembly, the patent avoids the need for separate complex mechanisms while still enabling the lower section to move backward relative to the upper section during acceleration.
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 head and upper body backward inclination during acceleration, reduces occupant incongruity, and secures holdability and steering comfort by modulating the spring constants of the seat back's support sections, ensuring a stable and comfortable seating experience.
Implementation Method 1
support sections with varying spring constants, specifically designed to individually adjust the backward movement of skeletal parts
Implementation Method 2
when backward inertia force acts on the seated occupant, the lower thoracic support section is configured to displace backward greatly
Data Source
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AI summary
A seat back (20) includes an upper thoracic support section (20a) for supporting at least a portion corresponding to a lower part of the upper thoracic spine of a seated occupant, and a lower thoracic support section (20b) disposed on a front side with respect to the upper thoracic support section (20a) and configured to support a portion corresponding to the lower thoracic spine of the seated occupant. The lower thoracic support section (20b) is configured to displace backward greatly, as compared with the upper thoracic support section (20a) in such a way that the upper thoracic spine of the seated occupant is inclined forward, when backward inertia force acts on the seated occupant.