Foam Part with Integrated Sensor Recesses for Occupancy Detection

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Solution Overview

Problem

Current seat occupancy detection systems in motor vehicles face challenges in reliably detecting the presence of vehicle occupants due to component tolerances and the need for precise sensor alignment, while also requiring expensive and complex manufacturing processes.

Innovation Solution

A foam part for motor vehicle seats with integrated seat occupancy detection sensors is developed, where sensors are positioned on the underside of the foam part within recesses, allowing for a defined distance from the seat surface and accommodating component tolerances, and can be either foamed in or glued during production, simplifying the manufacturing process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If sensors are positioned on the seat surface with precise alignment, then detection reliability is improved, but manufacturing complexity and cost increase

Engineering Contradiction:
Improveseat occupancy detection reliabilityVSAvoidsensor alignment complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The foam part is pre-formed with integrated sensor recesses and holding elements during the foaming process. This preliminary structuring ensures that sensors are automatically positioned at the correct depth and orientation relative to the seat surface, eliminating the need for complex post-assembly alignment procedures while maintaining reliable detection.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The foam part serves as an intermediary element that integrates both the structural support function and the sensor mounting function. By incorporating holding elements directly into the foam structure, the patent creates a mediating component that simplifies the connection between sensors and the seat frame, reducing overall system complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If sensors are positioned close to the seat surface for accurate detection, then measurement precision is improved, but component tolerances cause misalignment

Engineering Contradiction:
Improveoccupant detection precisionVSAvoidsensor positioning precision
Core Design Contradiction:
Measurement precisionVSManufacturing precision

Solution Approach 1:

The foam part features localized recesses with specific geometric characteristics (depth, width, shape) that are tailored to each sensor's requirements. These locally optimized holding elements ensure that each sensor is positioned at the precise depth and orientation needed for accurate detection, compensating for variations in overall component tolerances.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent utilizes the foamable material's adjustable parameters (viscosity, expansion ratio, curing time) to create holding elements with precise dimensional characteristics. By controlling the foaming process parameters, the sensor recesses can be formed with high dimensional accuracy, ensuring consistent sensor positioning despite variations in other component tolerances.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If sensors are integrated into the foam part structure, then manufacturing simplicity is improved, but additional processing steps are required

Engineering Contradiction:
Improveassembly simplicityVSAvoidfoaming process complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent combines multiple functions into the foam part: structural support, comfort cushioning, and sensor mounting. By merging the holding elements for sensors directly into the foam structure during the foaming process, the patent eliminates separate mounting brackets or fastening mechanisms, simplifying the overall manufacturing process despite the added complexity in the foaming step.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The foam part is designed as a universal component that performs multiple functions: it provides the structural framework for the seat, offers comfort through its cushioning properties, and serves as the mounting substrate for occupancy detection sensors. This multi-functionality reduces the total number of separate components needed, simplifying manufacturing and assembly.

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

Data Source

PatentEP3746329B1Foam part of a motor vehicle seat having seat occupancy detection, and method for the production thereof
Publication Date: 2021.10.06 AUDI AG
  • EP3746329B1 patent drawingFigure 1~3

AI summary

The invention relates to a foam part (14) of a motor vehicle seat having seat occupancy detection, wherein the foam part (14) comprises a seat surface (11) and an underside (12) opposite the seat surface, and wherein a number of seat occupancy detection sensors (2) are arranged in the region of the underside (12) and these are secured to the foam part (14) via a number of retaining profiles (20) for detecting a weight force acting on the seat surface (11). The invention also relates to a method for producing a foam part (14) of this type and to a motor vehicle seat having the foam part (14).