Crankcase Ventilation Leak Detection Using Single Pressure Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing closed crankcase ventilation (CCV) systems lack accurate and reliable diagnostic methods to detect small leaks and defects, which are critical for maintaining low emissions from internal combustion engines.
Innovation Solution
A diagnostic system using a single pressure sensor to measure pressure in the blow-by line relative to atmospheric pressure, calculating delta pressure and average pressure over a defined time period, and comparing these values to calibrated thresholds to detect leaks, with optional dual pressure sensors for additional sections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If traditional open crankcase ventilation systems are used, then the system structure is simple, but emissions increase due to direct atmospheric release
Solution Approach 1:
The patent converts the harmful blow-by gases that would otherwise be released into the atmosphere into a beneficial resource by routing them through the blow-by line back into the air intake system, where they are reused in the combustion process, thereby reducing emissions while maintaining system feasibility
2Object-generated harmful factors
If closed crankcase ventilation systems are implemented, then emissions are reduced, but diagnostic accuracy for detecting small leaks deteriorates
Solution Approach 1:
The patent replaces complex mechanical diagnostic systems with an electronic pressure sensor-based diagnostic system that continuously monitors pressure in the blow-by line and uses electronic signal processing to detect leaks, thereby improving measurement precision while maintaining system simplicity
Solution Approach 2:
The patent implements a feedback mechanism where the pressure sensor continuously monitors the blow-by line pressure and feeds this information back to the control unit, which compares the pressure against threshold values to detect leaks, enabling continuous diagnostic monitoring without increasing system complexity
3Measurement precision
If differential pressure measurement with two sensors is used, then measurement precision improves, but device complexity increases
Solution Approach 1:
The patent extracts and eliminates the unnecessary second pressure sensor from the system, demonstrating that a single pressure sensor measuring absolute or gauge pressure in the blow-by line is sufficient for accurate leak detection when combined with appropriate threshold comparison logic, thereby reducing device complexity while maintaining measurement precision
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
Enhances the sensitivity and accuracy of leak detection in CCV systems without increasing sensor complexity, ensuring timely maintenance and reducing emissions.
Implementation Method 1
When the internal combustion engine is running, the air intake line provides a vacuum source for drawing blow-by gases from the crankcase through the blow-by line
Implementation Method 2
One or more pressure sensors of the system are each arranged for measuring a pressure in the blow-by line relative to atmospheric pressure
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A closed crankcase ventilation system for removing blow-by gases, leaking from a combustion chamber, from a crankcase of an internal combustion engine. The system comprises a blow-by line extending between the crankcase and an air intake line of the internal combustion engine. When the engine is running, the air intake line provides a vacuum source for drawing blow-by gases from the crankcase through the blow-by line. A crankcase depression regulator is arranged in the blow-by line for regulating a level of vacuum inside the crankcase. At least one pressure sensor is arranged for measuring a pressure in the blow-by line relative to atmospheric pressure. A control unit is arranged for detecting leakages in the blow-by line by performing a diagnostic test based on a pressure measurement signal from a single pressure sensor.