Common-Rail Fuel Leakage Detection via Valve Operating-Point Calibration

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Solution Overview

Problem

Existing leakage detection methods in fuel paths of engines, particularly in high-pressure common rail fuel delivery systems, lack sufficient sensitivity and are prone to false negatives due to variance in volume control valves, leading to potential engine failure and safety hazards.

Innovation Solution

An electronic control unit adjusts reference values based on the actual operating point of the volume control valve, comparing the control variable with a calibrated reference value to detect leaks, eliminating the need for additional sensors and accounting for valve variance through online calibration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If fixed reference values are used for leakage detection, then device complexity is reduced, but measurement precision deteriorates due to variance in volume control valves

Engineering Contradiction:
Improveleakage detection systemVSAvoidleakage detection sensitivity
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The system performs preliminary calibration by determining the actual operating point of the volume control valve before normal leakage detection. This preliminary action establishes valve-specific reference values that account for manufacturing variances, enabling subsequent precise leak detection without requiring complex real-time adjustments during operation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system changes the reference value parameter dynamically based on the actual operating point of the volume control valve. Instead of using fixed reference values, the system adapts the reference values to match the specific characteristics of each valve, thereby maintaining high measurement precision while managing device complexity through parameter adaptation rather than structural complexity.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If higher threshold values are used to avoid false detections, then reliability improves, but measurement precision deteriorates by reducing detection sensitivity

Engineering Contradiction:
Improveleakage detectionVSAvoidleakage detection sensitivity
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The system adapts the reference values based on the actual operating point of the volume control valve, which allows for lower threshold values without causing false detections. By personalizing the reference values to each valve's characteristics, the system achieves both high reliability (no false alarms) and high sensitivity (detects small leaks), resolving the contradiction between these two requirements.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4632211A1Device for detecting a leakage in a fuel path of an engine
Publication Date: 2025.10.15 LIEBHERR COMPONENTS COLMAR SAS
  • EP4632211A1 patent drawingFigure 1~2
  • EP4632211A1 patent drawingFigure 3~4
  • EP4632211A1 patent drawingFigure 5~6

AI summary

The present invention shows a device for detecting a leakage in a fuel path of a fuel delivery system of an engine (1), the fuel delivery system preferably being a common rail fuel delivery system, the device comprising: a volume control valve (2) for controlling a flow of the fuel into the fuel path toward the engine, and an electronic control unit, the electronic control unit being configured to determine a fuel quantity (5) of the fuel to be injected into a combustion chamber of the engine (1), control the volume control valve (2) by providing a control variable for controlling the volume control valve (2) in a feedback loop to maintain a desired pressure inside the fuel path, and compare the control variable with a reference value, which is determined based on the fuel quantity, in order to detect a leakage in the fuel path, wherein the electronic control unit is configured to determine an actual operating point (4) of the volume control valve (2) for at least one fuel quantity (5) and to adjust and/or determine at least one reference value used for leakage detection based on the actual operating point (4).