Fuel Leakage Detection Arrangement With Resettable Indicator

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Solution Overview

Problem

Existing leakage detection arrangements for fuel injection systems require disassembly to reset the indicator pin after detecting a leak, which is inconvenient and poses a risk of fuel spillage, especially with toxic fuels like methanol.

Innovation Solution

A leakage detection arrangement featuring a fluid chamber, an indicator element, and a retaining element with a groove that allows the indicator element to move from a retracted to a protruding position due to fuel pressure, and a groove in a holding element to keep the retaining element in place, enabling easy resetting without dismounting parts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the indicator pin is provided with a snap ring to prevent unintentional movement, then the reliability of the indicator position is improved, but the ease of operation for resetting the indicator deteriorates

Engineering Contradiction:
Improveindicator position stabilityVSAvoidresetting operation
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The holding element is divided into a groove for the retaining element and a tapered section. The retaining element (snap ring) is segmented from the indicator pin, allowing it to be independently positioned in the groove. This segmentation enables the snap ring to provide reliable retention while allowing easy resetting by simply pushing the indicator pin, as the snap ring remains in the groove and does not require removal.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The groove in the holding element acts as an intermediary structure that accommodates the retaining element. This groove mediates between the need for secure retention (holding the snap ring in place) and the need for easy resetting (allowing the indicator pin to move freely while the snap ring stays in the groove). The tapered section of the groove serves as a guide that facilitates the snap ring's positioning without requiring disassembly.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the indicator pin requires disassembly for resetting, then the retaining element can be properly positioned, but the risk of fuel spillage increases

Engineering Contradiction:
Improveretaining element positioningVSAvoidfuel spillage risk
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The groove is pre-formed in the holding element during manufacturing, with the tapered section already in place. This preliminary action ensures that when the retaining element is installed, it will be properly positioned and guided by the tapered section. This eliminates the need for disassembly during resetting operations, as the groove structure is already prepared to accommodate the snap ring, thereby preventing fuel spillage risk.

Inventive Principle:
Principle #10Preliminary action

3Ease of repair

If the indicator element can be easily removed for maintenance, then the ease of repair is improved, but the device complexity increases

Engineering Contradiction:
Improveindicator element removalVSAvoidholding element structure
Core Design Contradiction:
Ease of repairVSDevice complexity

Solution Approach 1:

The holding element is segmented into distinct functional zones: a groove for retaining element accommodation and a tapered section for guiding. This segmentation allows the indicator pin to be easily removed and reinstalled by simply pushing it through the holding element, while the groove structure remains as a simple guiding feature. The segmentation enables easy repair operations without requiring complex disassembly procedures.

Inventive Principle:
Principle #1Segmentation

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

Enables quick and safe resetting of the indicator element to its retracted position without disassembly, preventing fuel spillage and facilitating maintenance, especially in systems using toxic fuels.

Implementation Method 1

the indicator element being configured to move due to fuel pressure in the fluid chamber from the retracted position to the protruding position

Methodology Applied
Scientific EffectFuel pressure: Pressure Increase

Data Source

PatentEP3359801B1Leakage detection arrangement
Publication Date: 2019.07.17 WARTSILA FINLAND OY
  • EP3359801B1 patent drawingFigure 1~3

AI summary

The leakage detection arrangement for detecting a leakage in a fuel injection system comprises a fluid chamber (1) arrangeable in fluid communication with a leakage channel (2, 3), an indicator element (5) that is configured to move due to fuel pressure in the fluid chamber (1) from a retracted position to a protruding position thus indicating a leakage, and a retaining element (6), which is arranged around the indicator element (5) and configured to keep the indicator element (5) in the retracted position and allow movement of the indicator element (5) to the protruding position when the force applied to the indicator element (5) by the fuel pressure in the fluid chamber (1) exceeds a predetermined threshold. The arrangement comprises a groove (7) which is arranged in a part (8) surrounding the indicator element (5) and which is configured to accommodate the retaining element (6).