Seating Sensor Fitting Portion Breakage Prevention

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Solution Overview

Problem

Existing seating sensors face challenges in maintaining assemblability and preventing fitting piece breakage due to stress concentration when loaded, as thin fitting pieces are prone to breaking under deformation, while thick pieces hinder elastic deformation and assembly.

Innovation Solution

The seating sensor design features a fitting portion with a first fitting piece that is easily deformed to widen the space between pieces, allowing a second thicker fitting piece to absorb stress, and includes arm portions and slip-off preventing features to limit positional deviation and enhance rigidity, reducing the risk of breakage and improving assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the fitting pieces are thinned to be easily elastically deformed for improved assemblability, then the assemblability is improved, but the fitting pieces may be broken due to stress concentration when the holder is deformed under load

Engineering Contradiction:
ImproveassemblabilityVSAvoidfitting piece breakage resistance
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The holder is divided into multiple fitting pieces (first fitting piece and second fitting piece) that are arranged side by side. This segmentation allows the load to be distributed across multiple pieces rather than concentrating stress on a single thin piece, enabling the use of thinner, more easily deformable pieces while maintaining breakage resistance through collective load bearing.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The first and second fitting pieces are positioned at specific locations (end portion and vicinity behind the first fitting piece) of the holder. This local arrangement creates a distributed support structure where each piece handles localized stress, allowing thin pieces to be used at critical assembly locations while maintaining overall structural reliability under load.

Inventive Principle:
Principle #3Local quality

2Reliability

If the fitting pieces are made thick to enhance rigidity and prevent breakage, then the breakage resistance is improved, but the fitting pieces become difficult to be elastically deformed, deteriorating the assemblability

Engineering Contradiction:
Improvefitting piece breakage resistanceVSAvoidassemblability
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

Instead of using a single thick fitting piece, the structure employs multiple thinner fitting pieces arranged side by side. The collective rigidity of multiple pieces provides sufficient load-bearing capacity while each individual piece remains thin enough to be easily elastically deformed during assembly, resolving the contradiction between thickness for rigidity and thinness for assemblability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Multiple fitting pieces are merged into a single functional unit that works together to support the holder. The combined effect of several thin pieces provides the necessary rigidity and load distribution, while each piece maintains the flexibility needed for easy elastic deformation during assembly operations.

Inventive Principle:
Principle #5Merging (Combining)

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 design effectively suppresses fitting piece breakage without compromising assemblability, enhances load information detection performance, and improves the sensor's robustness and durability.

Implementation Method 1

when the first fitting piece is mainly elastically deformed at the time of mounting the fitting portion on the support member, the space between the first and second fitting pieces is widened

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

the second fitting piece may be suppressed from being broken

Methodology Applied
Scientific EffectStress absorption:

Implementation Method 3

the rigidity of the second fitting piece may be enhanced by making the second fitting piece thick

Methodology Applied
Scientific EffectRigidity:

Implementation Method 4

a slip-off preventing portion protruding from a tip end of the first fitting piece toward the second fitting piece

Methodology Applied
Scientific EffectMechanical constraint: Mechanical Fastener

Implementation Method 5

an arm portion protruding downward from the holder; and a second slip-off preventing portion protruding from a tip end of the arm portion and configured to be brought into contact with or located close to the support member

Methodology Applied
Scientific EffectMechanical constraint: Mechanical Fastener

Data Source

PatentEP3381740B1Seating sensor
Publication Date: 2019.12.25 AISIN SEIKI KK
  • EP3381740B1 patent drawingFigure 1
  • EP3381740B1 patent drawingFigure 2
  • EP3381740B1 patent drawingFigure 3

AI summary

A seating sensor (30) includes: a holder (31) configured to be placed, in a state of being sandwiched between a cushion member (20) of a seat cushion (6) and a support member (SU) supporting the cushion member, on the support member; a sensor body (40) placed on the holder and configured to detect information of a load applied from the cushion member; a fitting portion (34) including a first fitting piece (34a) protruding downward from an end portion of the holder and a second fitting piece (34b) adjacent to an opposite side to the end portion of the first fitting piece and protruding downward from the holder, and mounted on the support member in a state where the support member is fitted between the first and second fitting pieces; and a slip-off preventing portion (35) protruding from a tip end of the first fitting piece toward the second fitting piece.