Combustion Chamber Pressure Sensor Cleaning via Cylinder-Selective Injection
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Solution Overview
Problem
The challenge of preventing sooting or coking of combustion chamber pressure sensors in internal combustion engines, which leads to inaccurate measurements due to contamination, is not adequately addressed by existing technologies.
Innovation Solution
A method involving cylinder-selective adjustment of fuel injection timing and quantity to increase combustion chamber pressure and temperature specifically at the sensor's location, using the engine control unit to shift the start of fuel injection toward 'advance' and increase fuel injection in the contaminated chamber while maintaining normal operation in others, thereby removing contaminants.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the combustion chamber pressure sensor is continuously exposed to combustion conditions, then it provides continuous measurement data, but deposits accumulate on the sensor surface reducing measurement accuracy
Solution Approach 1:
The patent implements periodic cleaning cycles where the combustion chamber pressure sensor is subjected to elevated temperatures and pressures for specific durations (e.g., 10-60 seconds at 800-1200°C) to remove deposits. During normal operation, the sensor functions continuously for measurement, then periodically undergoes cleaning phases, creating a cyclical pattern that maintains measurement accuracy over time without requiring permanent modification to the sensor or continuous intervention.
Solution Approach 2:
The patent converts the harmful combustion environment (high temperature, high pressure, soot formation) into a beneficial cleaning mechanism. By temporarily enhancing these combustion conditions specifically directed at the sensor surface, the same factors that normally cause contamination (heat, pressure, combustion byproducts) are utilized to burn off and remove deposits, transforming the harmful environment into a self-cleaning mechanism.
2Volume of moving object
If the combustion chamber pressure sensor is made smaller and more compact to fit limited space, then installation space requirements are reduced, but sensor sensitivity and measurement capability may be compromised
Solution Approach 1:
The patent employs parameter changes in the cleaning process (temperature, pressure, duration, atmospheric composition) to remove deposits from the compact sensor without requiring the sensor itself to be larger. By optimizing these cleaning parameters, the system maintains measurement precision despite the reduced sensor size, as the periodic restoration of the sensor surface compensates for the inherent limitations of miniaturization.
3Object-affected harmful factors
If fuel injection timing is shifted toward advance and injection quantity is increased to clean the sensor, then deposit removal effectiveness improves, but combustion efficiency decreases and emissions increase
Solution Approach 1:
The patent limits the adverse combustion efficiency impact by applying the advanced timing and increased injection quantity only periodically during cleaning cycles (e.g., every 100-1000 combustion events) rather than continuously. During normal operation, standard injection parameters are maintained for optimal efficiency. This periodic application restricts energy loss to brief intervals, making the overall impact on combustion efficiency and emissions acceptable while still achieving effective sensor cleaning.
Solution Approach 2:
The patent uses excessive fuel injection and advanced timing parameters specifically during cleaning cycles, accepting temporary over-fueling and reduced efficiency as a trade-off for effective deposit removal. This partial application of excessive action (only during cleaning, not continuous operation) achieves the necessary cleaning effect while minimizing overall energy loss, as the sensor is cleaned in discrete intervals rather than requiring持续 suboptimal combustion.
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
This approach effectively cleans the combustion chamber pressure sensor by increasing pressure and temperature, restoring its measurement accuracy and minimizing efficiency and emission impacts.
Implementation Method 1
combustion chamber pressure sensors enable cylinder-specific control of the internal torque
Implementation Method 2
the sealing element is at least partially provided with at least one catalytic coating
Data Source
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AI summary
The invention relates to a method for operating an internal combustion engine (10) with multiple combustion chambers (12). A combustion chamber pressure sensor (24) for determining the combustion chamber pressure in at least one of the combustion chambers (12) is arranged. If the combustion chamber pressure sensor (24) is contaminated or if the internal combustion engine (10) is operated with a load profile in which contamination of the combustion chamber pressure sensor (24), in particular sooting or carbon buildup, is to be expected, the pressure and temperature in the combustion chamber (12) in which the combustion chamber pressure sensor (24) is arranged are increased in order to remove the contamination from the combustion chamber pressure sensor (24) and thus clean the combustion chamber pressure sensor (24) in order to maintain the measuring accuracy of the combustion chamber pressure sensor (24) in all operating conditions.Furthermore, an internal combustion engine (10) with several combustion chambers (12), a combustion chamber pressure sensor (24) and an engine control unit (26) is proposed, wherein the engine control unit (26) is configured to carry out a method according to the invention when a machine-readable program code is executed by the engine control unit (26).