Vehicle Seat Adjusting Device with Toggle Lever Kinematics
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Solution Overview
Problem
Existing seat adjusting devices for vehicle seats face issues with inconsistent torque and rotational speed requirements, inefficient motor usage, and unwanted displacement of contact points, leading to suboptimal adaptation to passenger body shapes and increased noise and space requirements.
Innovation Solution
An adjusting device with a modular design that transforms linear movement into a curved or circular path, using a support lever and toggle lever system with adjustable kinematics, allowing for constant torque and speed over the adjustment path, reducing motor power needs, and maintaining consistent contact points, enabling efficient and quiet operation with minimal space.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional lumbar support adjusting devices are used with fixed wire and spindle mechanism, then the backrest can be adjusted for lumbar support, but the contact points migrate inwardly and outwardly causing pressure points to change in undesired manner
Solution Approach 1:
The adjusting device is divided into multiple independent components: a support element with first and second support portions, a cable running between them, and a housing containing the adjusting mechanism. This segmentation allows each component to maintain its function while preventing unwanted migration of contact points through the cable tensioning system.
Solution Approach 2:
The first and second support portions are positioned at different locations on the backrest to provide localized support in specific regions. The cable is tensioned to maintain consistent contact pressure at these specific locations, ensuring pressure points remain consistent without migrating during adjustment.
2Power
If the adjusting device uses a spindle mechanism with opposing threads and connecting arms, then lumbar support adjustment is achieved, but the transmission ratio is unfavorable requiring high loads on the drive
Solution Approach 1:
The complex spindle mechanism with opposing threads and multiple connecting arms is replaced with a cable-based tensioning system. The cable runs between the first and second support portions and can be tensioned by a simpler adjusting mechanism, eliminating the need for complex gear stages and reducing drive loads while maintaining adjustment functionality.
3Speed
If gear stages are added to reduce rotational speed of drive motors, then the adjusting arms can be lifted and lowered, but the efficiency of the overall system is reduced and higher motor power class is required
Solution Approach 1:
The cable-based tensioning system directly translates motor rotation into linear movement of the support portions without requiring intermediate gear stages. This direct mechanical transmission maintains system efficiency while achieving the required adjusting arm movement speed, eliminating energy losses associated with multiple gear reductions.
4Strength
If the adjusting device uses a fixed wire integrated into the strength structure, then the support structure is reinforced, but the adjusting elements cannot be easily replaced or maintained
Solution Approach 1:
The adjusting device is designed as a separate, modular unit with the cable, housing, and support portions as distinct components. This segmentation allows the adjusting elements to be independently replaced or maintained without compromising the integrated strength structure of the backrest, while the cable itself provides the necessary structural reinforcement.
Data Source
AI summary
It is provided an adjusting device for a seat element of a vehicle seat, the strength structure of said seat element being connected to a guide device which substantially oriented in a first spatial direction and on which a support and a slide are arranged in a longitudinally adjustable manner relative to each other by means of a first drive device. A support lever which changes the contour of the seat element and which is hinged to the support and a toggle lever which is hinged to the slide and to the support lever via a connection joint are pivotable about axes which are oriented in a second spatial direction running perpendicularly to the first spatial direction and pivot on a plane defined by the first spatial direction and a third spatial direction running perpendicularly to the first and second spatial direction when the first drive device is actuated.