Crankcase Ventilation Line Leak Diagnosis Using Exhaust Sensors
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Solution Overview
Problem
Existing methods for diagnosing leaks in crankcase ventilation lines of internal combustion engines are inefficient and require additional components, leading to increased costs and complexity, while legislative requirements necessitate reliable leak-tightness monitoring.
Innovation Solution
A method utilizing existing exhaust-gas sensors and pressure sensors to analyze the influence of gas introduction into the crankcase through an aeration line, comparing actual measurement profiles with expected profiles to detect deviations indicative of leaks, without requiring additional components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If additional components are used for leakage diagnosis, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent applies multi-functionality by enabling existing exhaust-gas sensors and pressure sensors to serve dual purposes: their original functions for engine operation monitoring and the additional function of crankcase ventilation line leakage diagnosis. This eliminates the need for separate diagnostic components while maintaining detection capability.
Solution Approach 2:
The system uses its own existing sensors to perform self-diagnosis. The exhaust-gas sensor and pressure sensor, already deployed for engine monitoring, automatically detect leakage conditions without requiring external diagnostic equipment or additional components, achieving self-service leakage detection.
2Reliability
If additional components are installed for leakage monitoring, then reliability is improved, but manufacturing cost increases
Solution Approach 1:
Existing sensors are made multi-functional, allowing them to perform both their original engine monitoring tasks and crankcase ventilation leakage detection. This approach achieves reliable monitoring without the additional manufacturing costs associated with installing separate diagnostic components.
Solution Approach 2:
The engine control system performs self-diagnosis using existing sensors, eliminating the need for additional hardware installations. This self-service approach maintains high reliability for leakage monitoring while avoiding the increased manufacturing costs that would result from adding separate diagnostic components.
3Device complexity
If existing sensors are used for diagnosis, then device complexity is reduced, but measurement precision may worsen
Solution Approach 1:
The system dynamically adapts the usage of existing sensors for leakage diagnosis by controlling the aeration line valve to create specific pressure and flow conditions. This dynamic control enables the exhaust-gas sensor and pressure sensor to detect leakage accurately despite being designed for their original purposes, maintaining precision without additional components.
Solution Approach 2:
The patent changes operational parameters by controlling the aeration line valve to establish specific pressure differentials and gas flow patterns during diagnosis mode. These parameter changes enable existing sensors to detect leakage conditions with sufficient accuracy, transforming their measurement capabilities without requiring hardware modifications.
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 simple, reliable, and cost-effective leakage diagnosis of crankcase ventilation lines by using existing engine components, ensuring rapid and precise identification of leaks.
Implementation Method 1
an exhaust-gas sensor which is configured to acquire a measurement signal profile which is characteristic of at least one exhaust-gas property of the exhaust gas in the exhaust-gas tract
Implementation Method 2
a pressure sensor which is configured to acquire a pressure measurement signal profile which is characteristic of the pressure profile in the crankcase ventilation line
Implementation Method 3
Due to a pressure drop from the crankcase to the intake tract, a mass flow from the crankcase into the intake tract is generated
Implementation Method 4
the fuel evaporates again as operating temperatures rise
Data Source
AI summary
The disclosure relates to a method for leakage diagnosis. The method includes influencing the introduction of gas along a crankcase aeration line into a crankcase of an internal combustion engine and acquiring a measurement signal profile by an exhaust-gas sensor arranged in an exhaust-gas tract of an internal combustion engine. The measurement signal profile is characteristic of at least one exhaust-gas property of the exhaust gas. The method includes providing an expected measurement signal profile which is characteristic of the exhaust-gas property of the exhaust gas in the exhaust-gas tract based on the influence on the introduction of gas into the crankcase. Additionally, the method includes comparing the acquired measurement signal profile with the expected measurement signal profile and identifying that the crankcase ventilation line has a leak if, during the comparison, the acquired measurement signal profile deviates from the expected measurement signal profile by a predetermined threshold value.