Fluid Level Sensor Mount Structure With Adjustable Grooves

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Solution Overview

Problem

Existing fluid level sensing apparatus mount structures for fuel tanks lack adjustability and are costly due to material constraints, with previous solutions either requiring difficult process control for soldering or limiting mounting orientations and material choices.

Innovation Solution

A mount structure featuring groove portions and engagement projections that allow adjustable vertical positioning of the fluid level sensing apparatus, using an electrically conductive holding member with an elastic portion for secure attachment and grounding, enabling flexible orientation and reduced material costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If direct soldering of the earth cable to the thermistor housing is used, then grounding is achieved, but the heat generated may break wiring inside the housing causing sensing failure

Engineering Contradiction:
Improvegrounding reliabilityVSAvoidheat damage to wiring
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a metal holding member as an intermediary between the earth cable and the thermistor housing. The earth cable is soldered to the holding member rather than directly to the housing, and the holding member provides the grounding connection. This intermediary structure prevents heat damage to the housing wiring while achieving reliable grounding through the holding member's electrical conductivity.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of manufacture

If the thermistor is held only by elastic force of a resin holder, then mounting is simplified, but the holding force weakens due to resin swelling

Engineering Contradiction:
Improvemounting simplicityVSAvoidholding force
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The patent employs a composite structure where a metal holding member provides both the holding force and grounding function. The metal material combines elastic properties for holding the thermistor securely with electrical conductivity for grounding, overcoming the limitations of resin materials that lack sufficient holding strength when swollen and do not provide inherent grounding capability.

Inventive Principle:
Principle #40Composite materials

3Reliability

If the holder is made of electrically conductive material to provide grounding, then grounding is achieved, but material choices are limited and costs increase

Engineering Contradiction:
Improvegrounding capabilityVSAvoidmaterial selection freedom
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent segments the functions by introducing a separate metal holding member specifically for grounding and holding purposes, while the resin cover member focuses on protection and structural support. This segmentation allows each component to be optimized for its specific function - the metal holding member provides grounding and elastic holding, while the resin cover provides environmental protection - without requiring the main housing material to have special electrical properties.

Inventive Principle:
Principle #1Segmentation

4Reliability

If a spring is used to ground the thermistor, then grounding is achieved, but the mounting orientation is limited to a specific order

Engineering Contradiction:
Improvegrounding connectionVSAvoidmounting orientation flexibility
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent uses an elastic holding member with engagement portions that can adapt to different orientations. The elastic portion allows the holding member to deform and maintain contact with the thermistor flange regardless of mounting orientation, while the engagement portions provide secure mechanical connection. This dynamic elastic structure replaces the rigid spring mechanism, enabling flexible mounting in any orientation while maintaining reliable grounding and holding.

Inventive Principle:
Principle #15Dynamics

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 allows for easy adjustment and secure mounting of the fluid level sensing apparatus at various positions, reducing material costs and preventing terminal damage, while allowing for multiple mounting orientations.

Implementation Method 1

an electrically conductive holding member (22) provided with an elastic portion (23) that elastically holds the fluid level sensing apparatus

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

the holding member (22) being connected with an earth cable (26)

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP2169363B1Fluid level sensing apparatus mount structure
Publication Date: 2011.05.04 KEIHIN CORP
  • EP2169363B1 patent drawingFigure 1
  • EP2169363B1 patent drawingFigure 2
  • EP2169363B1 patent drawingFigure 3

AI summary

The invention provides a fluid level sensing apparatus mount structure in which the level of the apparatus can easily be adjusted, and that is inexpensive and can easily mount the fluid level sensing apparatus. The mount structure includes a fluid level sensing apparatus mount portion 17 having a plurality of groove portions 20 to which a flange portion 19 provided on a thermistor 16 is to engage, the groove portions being provided at different vertical positions on the fluid level sensing apparatus mount portion, an engagement projection 21 provided on the fluid level sensing apparatus mount portion 17, an electrically conductive holding member 22 provided with an elastic portion 23 that elastically holds the thermistor 16, the holding member 22 being connected with an earth cable 26, and an engagement hole 25 provided on the holding member 22 and engaging with the engagement projection 21.