Motor Vehicle Seat Frame Hinge Shaft Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Seat frames in motor vehicles face challenges in minimizing bending moments in side parts due to reaction forces from adjustment devices, which also limits space for additional components and compromises stability.
Innovation Solution
A motor vehicle seat design featuring a pivotal bridge with a motor-driven drive unit and a hinge shaft that is shorter than the distance between side parts, forming a four-bar linkage to distribute forces and prevent bending moments, while allowing additional space for other components between the side parts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a motor-driven adjustment device is integrated into the seat frame, then seat adjustment functionality is achieved, but bending moments are introduced into the side parts causing deformation
Solution Approach 1:
A hinge shaft is introduced as an intermediary component between the adjustment device and the side parts. The hinge shaft is positioned such that it does not contact or minimally contacts the side parts, acting as a mediator that transfers adjustment forces while preventing direct transmission of bending moments to the side parts, thus resolving the contradiction between achieving adjustment functionality and maintaining side part stability
2Strength
If the hinge shaft extends across the full distance between side parts, then structural support is maximized, but space for additional components is reduced
Solution Approach 1:
The hinge shaft is segmented in length, extending only over part of the distance between the two side parts rather than spanning the full distance. This segmentation maintains sufficient structural support for the adjustment device while creating free space between the hinge shaft and the side parts, allowing accommodation of additional components such as vibration motors or heating elements
3Adaptability or versatility
If the side parts are designed to accommodate adjustment devices, then adjustment functionality is enabled, but bending moments cause the side parts to bulge outward or inward
Solution Approach 1:
The hinge shaft serves as a mediator that decouples the adjustment device from direct contact with the side parts. By positioning the hinge shaft such that it does not contact or minimally contacts the side parts, the transmission of forces is optimized to prevent bending moments from causing shape deformation, while still enabling full adjustment functionality
Solution Approach 2:
Instead of designing the side parts to directly support the adjustment device (which causes bending), the design is inverted by using a separate hinge shaft structure that supports the adjustment device while minimizing interaction with the side parts. This inversion of the support structure eliminates the shape deformation problem while maintaining adjustment capability
Data Source
AI summary
The invention relates to a seat frame of a motor vehicle seat with a seat carrier having two side parts that are oriented transverse to a front axis and to a rear axis, a pivotal bridge being pivotal about at least one of said axes, said bridge comprising a tie bar and two side arms, and with an adjustment device having a motor-driven drive unit. The drive unit is arranged for pivotal movement about a hinge shaft that is substantially centered on that axis of the two axes about which said pivotal bridge is pivotal. Said hinge shaft is shorter than the distance between the two seat parts and is not in contact with said two seat parts, but if at all with only one side part. There is provided at least one inner arm that connects said tie bar to said hinge shaft and is located in proximity to said drive unit.