Load detection sensor

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Load detection sensors face issues with adhesive layer variations due to temperature changes, leading to inconsistent load measurements, especially in extreme environments, and creep deformation causing distance changes between electrodes.

Innovation Solution

Incorporating an annular member without adhesion to the electrodes, which supports the electrodes and maintains a constant distance, reducing the impact of adhesive layer variations and creep deformation, and using a vent to prevent air-induced deflection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If an adhesive layer is used to bond the first electrode sheet and the second electrode sheet, then the electrodes are securely connected, but the adhesive layer softens at high temperatures and hardens at low temperatures, causing variation in the load necessary for electrode contact

Engineering Contradiction:
Improvebonding strengthVSAvoidload detection consistency
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent introduces an annular member as an intermediary component between the first and second electrode sheets. This annular member provides a stable supporting structure that is not affected by temperature-induced adhesive property changes, thereby mediating the connection and eliminating the reliability issues caused by adhesive layer variation

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent divides the bonding structure into separate functional components: the adhesive layer for basic bonding and the annular member for structural support and spacing. This segmentation allows each component to perform its specific function without interfering with the other, preventing the adhesive's temperature sensitivity from affecting overall sensor performance

Inventive Principle:
Principle #1Segmentation

2Strength

If glue is used to bond the resin films, then the films are securely attached, but long-term pressing causes the glue to creep-deform, varying the distance between the films and causing load detection variation

Engineering Contradiction:
Improvebonding strengthVSAvoiddistance between films
Core Design Contradiction:
StrengthVSStability of the object's composition

Solution Approach 1:

The annular member acts as an intermediary structural element that maintains the spacing between electrode sheets independently of the adhesive layer. By providing rigid support and defined spacing, it mediates the mechanical relationship between films, preventing creep deformation from affecting the distance stability

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the mechanical parameters of the bonding system by introducing the annular member with specific dimensional properties (thickness, outer diameter, inner diameter). These parameter changes create a stable geometric constraint that prevents film displacement and maintains consistent spacing under long-term loading conditions

Inventive Principle:
Principle #35Parameter changes

3Strength

If the annular member adheres to the electrode sheets through an adhesive layer, then the structure is more rigid, but the adhesive layer varies with temperature, causing variation in the degree of inward deflection and load necessary for contact

Engineering Contradiction:
Improvestructural rigidityVSAvoiddeflection consistency
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The annular member serves as an intermediary support structure that provides rigidity without relying on temperature-sensitive adhesive bonds to the electrode sheets. By being non-adhesive, it eliminates the source of deflection variation while still providing the necessary structural support through its geometric form and material properties

Inventive Principle:
Principle #24Intermediary (Mediator)

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

The solution ensures stable and consistent load detection across varying temperatures, reducing false detections and maintaining accurate measurements even under high-temperature and low-temperature conditions and long-term pressing.

Implementation Method 1

the annular member has a vent for deflation of air in the opening of the spacer

Methodology Applied
Scientific EffectAir pressure release: Depressurisation

Data Source

PatentEP3591682B1Load detection sensor
Publication Date: 2024.11.20 FUJIKURA LTD
  • EP3591682B1 patent drawingFigure 1
  • EP3591682B1 patent drawingFigure 2~3
  • EP3591682B1 patent drawingFigure 4

AI summary

A load detection sensor (5A) includes: a first electrode sheet (6) including a first electrode (62); a second electrode sheet (7) including a second electrode (72) opposed to the first electrode (62); a spacer (8) interposed between the first electrode sheet (6) and the second electrode sheet (7), the spacer (8) having an opening (81) between the first electrode (62) and the second electrode (72); an annular member (9) disposed in the opening (81); and an adhesive layer (10) disposed at least either between the spacer (8) and the first electrode sheet (6) or between the spacer (8) and the second electrode sheet (7). The annular member (9) is in contact with at least one of the first electrode sheet (6) exposed at the opening (81) and the second electrode sheet (7) exposed at the opening (81), and has no adhesion to both of the first electrode sheet (6) and the second electrode sheet (7).