Adaptive Lumbar Support in Vehicle Seats for Oscillation Stability

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Solution Overview

Problem

Existing vehicle seats struggle to maintain an appropriate sitting posture for occupants during vehicle oscillations, such as on bad roads, cornering, or acceleration, as they fail to effectively adjust the elastic forces in response to changing conditions.

Innovation Solution

The vehicle seat incorporates an elastic force adjustment unit that dynamically adjusts the tension of wires supporting the sacrum, lumbar spine, and thoracic spine regions, making the lumbar spine support's elastic force larger than the sacrum and thoracic spine supports during significant vehicle oscillations to stabilize the upper body and reduce head oscillation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the elastic force of the seat back is increased to curb upper body movement during vehicle oscillation, then the stability of the occupant's upper body is improved, but the comfort of the occupant is worsened due to excessive rigidity

Engineering Contradiction:
Improvestability of upper body postureVSAvoidoccupant discomfort
Core Design Contradiction:
Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The seat back structure transitions from a fixed rigid state to a dynamic adjustable state. The control unit receives vehicle state information and dynamically adjusts the elastic force of the seat back according to real-time vehicle conditions, enabling the seat back to adapt its stiffness characteristics to different operating scenarios rather than maintaining a constant rigid structure

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The elastic force parameter of the seat back is made variable through active control. The control unit modifies the elastic force parameter based on vehicle state inputs, changing the mechanical properties of the seat back to match different vehicle oscillation conditions, thereby optimizing both stability and comfort across varying operational contexts

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If the seat back structure is made more complex to dynamically adjust elastic force, then the adaptability to vehicle oscillation is improved, but the device complexity increases

Engineering Contradiction:
Improveadaptability to vehicle oscillationVSAvoidcomplexity of elastic force adjustment mechanism
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The control unit serves multiple functions: it receives various vehicle state information inputs, processes this information to determine appropriate elastic force adjustments, and controls the elastic force mechanism. This multi-functional approach consolidates what could be separate complex systems into a single integrated control unit, reducing overall system complexity while maintaining high adaptability

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

This adjustment ensures the upper body posture is maintained appropriately, and head oscillation is minimized by increasing the support load of the lumbar spine region, effectively curbing movement and inclination during vehicle shakes.

Implementation Method 1

wire springs with a resilience adjustment plate

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3632741B1Vehicle seat
Publication Date: 2024.10.16 TOYOTA JIDOSHA KK
  • EP3632741B1 patent drawingFigure 1
  • EP3632741B1 patent drawingFigure 2
  • EP3632741B1 patent drawingFigure 3

AI summary

A vehicle seat (10; 80; 90; 100) includes a seat cushion (14) configured to support the buttocks (67) of an occupant (60), a seat back (36) configured to support the back (61) of the occupant (60), an elastic force adjustment unit (40) configured to adjust elastic force of a lumbar spine support (36Y) of the seat back (36) configured to support the lumbar spine (64) of the occupant (60), in a longitudinal direction, and a controller (41) configured to operate the elastic force adjustment unit (40). The controller (41) is configured to make the elastic force larger in the case where oscillation of the vehicle is large, than that in the case where oscillation of the vehicle is small.