Crankcase Ventilation Blockage Detection Using Nitrogen Oxide Sensing
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Solution Overview
Problem
Existing methods for monitoring the ventilation of a crankcase in internal combustion engines are not cost-effective and fail to reliably detect blockages or malfunctions in the ventilation system, leading to potential contamination and wear of internal components.
Innovation Solution
Utilizing a nitrogen oxide sensor in the exhaust tract to monitor crankcase ventilation by detecting nitrogen oxide levels during predetermined operating modes, such as an overrun fuel cut-off phase, to determine if the ventilation path is clear or blocked.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a nitrogen oxide sensor is used to monitor crankcase ventilation during predetermined operating modes, then the monitoring becomes cost-effective and simple, but the monitoring can only be performed during specific operating conditions
Solution Approach 1:
The monitoring system dynamically adapts to different operating modes by detecting the current engine state and selecting appropriate monitoring strategies. The control unit determines whether the engine is in a predetermined operating mode (such as overrun fuel cut-off phase) and activates monitoring only during these specific conditions, making the system both cost-effective and adaptable to varying operational requirements
Solution Approach 2:
The system changes its monitoring parameters based on operating conditions. During predetermined operating modes, the nitrogen oxide sensor uses specific threshold values and evaluation criteria that are optimized for those conditions. The control unit adjusts the monitoring sensitivity and threshold levels according to the detected operating mode, enabling cost-effective monitoring while maintaining accuracy across different engine states
2Device complexity
If the crankcase ventilation system is not monitored, then the system remains simple and low-cost, but blockages and malfunctions go undetected leading to contamination and wear
Solution Approach 1:
The nitrogen oxide sensor, which is already present in the exhaust tract for other purposes, serves a dual function by also monitoring crankcase ventilation. This self-service approach allows the system to gain monitoring capability without adding dedicated sensors or complex diagnostic systems, maintaining simplicity while improving reliability through continuous ventilation status detection
Solution Approach 2:
The control unit continuously evaluates the nitrogen oxide sensor signals and provides feedback about the ventilation system status. When the sensor detects nitrogen oxide levels above predetermined thresholds during predetermined operating modes, the system generates diagnostic information indicating potential blockages or malfunctions, enabling timely maintenance while keeping the overall system simple
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 and cost-effective monitoring of crankcase ventilation, ensuring proper functioning and preventing contamination by detecting blockages or malfunctions, thereby reducing wear on internal components.
Implementation Method 1
a nitrogen oxide sensor provided in the exhaust tract of the internal combustion engine, in particular designed to detect the nitrogen oxide content in the exhaust gas of the internal combustion engine
Data Source
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AI summary
The present invention relates to a method for monitoring the ventilation of a crankcase (120) of an internal combustion engine (100), and to an internal combustion engine (100). The internal combustion engine (100) has combustion chambers (110) and a nitrogen oxide sensor (140) which is arranged in the exhaust gas tract (130) of the internal combustion engine (100) and designed to detect the nitrogen oxide content in the exhaust gas of the internal combustion engine (100). The method according to the invention comprises determining a predefined operating mode of the internal combustion engine (100) during which essentially no combustion takes place inside the combustion chambers (110), determining a nitrogen oxide content in the exhaust gas of the internal combustion engine (100) during the predefined operating mode of the internal combustion engine (100) by means of the exhaust gas sensor (140), and determining an operational ventilation of the crankcase (120) if the nitrogen oxide value determined during the predefined operating mode of the internal combustion engine (100) exceeds a predetermined nitrogen oxide threshold value.