Pre-ignition Detection via Combustion Chamber Surface Temperature
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Solution Overview
Problem
Existing methods for preventing pre-ignition in internal combustion engines can only detect and prevent pre-ignition after it occurs, leading to potential engine damage, and do not effectively anticipate and prevent it before the event.
Innovation Solution
A method that determines the risk of pre-ignition by measuring the surface temperature of the combustion chamber and compares it to a limit value, initiating changes in operating parameters of the drive train to prevent pre-ignition before it occurs, without requiring additional sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If additional sensors are installed to detect pre-ignition, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent reuses existing sensors (crankshaft position sensor, cylinder pressure sensor) that serve multiple functions. The crankshaft position sensor not only monitors engine timing but also detects pre-ignition through angular velocity analysis. The pressure sensor serves both combustion monitoring and pre-ignition detection, eliminating the need for dedicated pre-ignition sensors.
Solution Approach 2:
The system uses the engine's own operational parameters and existing sensor data to detect pre-ignition conditions. By analyzing the angular velocity profile from the crankshaft position sensor and pressure data from the cylinder pressure sensor, the system self-diagnoses pre-ignition without requiring external detection devices.
2Device complexity
If pre-ignition detection is delayed until after occurrence, then device complexity is reduced, but reliability deteriorates
Solution Approach 1:
The system performs preliminary detection of pre-ignition by continuously monitoring the angular velocity profile of the crankshaft during the compression phase. By analyzing deviations in the angular velocity curve before top dead center, the system detects pre-ignition tendencies in advance, allowing preventive measures to be taken before actual pre-ignition occurs.
Solution Approach 2:
The system implements continuous feedback monitoring of engine operational parameters including angular velocity, cylinder pressure, and operating conditions. This real-time feedback enables the control unit to detect pre-ignition tendencies and adjust operating parameters dynamically to prevent pre-ignition before it causes damage.
3Productivity
If compression ratio is increased to improve efficiency, then productivity is improved, but the risk of pre-ignition increases
Solution Approach 1:
The system dynamically adjusts operating parameters including ignition timing, injection timing, and air-fuel ratio based on real-time detection of pre-ignition tendencies. By monitoring angular velocity deviations and cylinder pressure, the control unit modifies combustion parameters to prevent pre-ignition even at high compression ratios, enabling the engine to operate efficiently at higher compression ratios without excessive pre-ignition risk.
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 allows for the proactive prevention of pre-ignition, avoiding engine damage and enabling increased supercharging and compression ratios, while reducing fuel consumption, and does not need additional sensors for detection.
Implementation Method 1
The internal cylinder pressure is determined using the recorded angular velocity profile of the crankshaft
Implementation Method 2
a measure of the surface temperature being determined as a measure of the risk of pre-ignition tendency
Implementation Method 3
The increases in temperature and pressure caused by the pre-ignition are intensified by the compression in the combustion chamber
Implementation Method 4
without an ignition spark having been generated by the ignition system
Data Source
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AI summary
The method (4) involves determining measure of risk of premature ignition (1) of a portion of a combustion chamber. Measurement of the surface temperature is determined (2) as measure of the risk of the premature ignition for subsequent or later cycle and compared with a predetermined limit value. Alternation in an operating parameter of a drive train is initiated (3) for non-compliance with a threshold value (5) for a preceding cycle in current or following working phase. The parameter of fuel quality is determined from evaluation of activity of knocking control. An independent claim is also included for an engine control equipment.