Engine Expansion Stroke Fuel Injection Control
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Solution Overview
Problem
Existing engine devices face challenges in setting the appropriate fuel injection amount for the expansion stroke, leading to potential discharge issues or soot production due to inadequate fuel injection, especially during engine starting and catalyst warming up.
Innovation Solution
An engine device with a controller that adjusts the fuel injection amount for the last fuel injection in the expansion stroke based on coolant start temperature, post-start time, and volumetric efficiency, ensuring synchronization with ignition and varying the opening degree of the in-cylinder injection valve, while using air-fuel ratio feedback control for other injections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the fuel injection amount for the last fuel injection in the expansion stroke is set too small, then discharge may not be induced, but if set too large, fine particles such as soot may be produced from incomplete combustion
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the fuel injection amount for the last fuel injection in the expansion stroke based on operating conditions (engine load, temperature, catalyst state). This allows the system to optimize the fuel amount to ensure proper discharge induction while preventing excessive fuel that would cause soot formation from incomplete combustion.
2Quantity of substance
If more fuel is injected in the intake stroke or compression stroke, then the fuel injection amount for the last injection can be reduced, but this may affect the overall combustion efficiency and emissions
Solution Approach 1:
The patent applies dynamics by implementing dynamic fuel injection control that adjusts the distribution of fuel injection amounts across different strokes (intake, compression, and expansion) based on real-time operating conditions. The controller dynamically determines the optimal fuel amount for the last injection in the expansion stroke to maintain combustion efficiency and control emissions while achieving proper discharge induction.
3Temperature
If the ignition timing is retarded to supply more heat to the exhaust gas control device, then the catalyst warms up faster, but this may affect the combustion stability and increase emissions
Solution Approach 1:
The patent applies parameter changes by coordinating ignition timing retardation with adjusted fuel injection amounts. When ignition timing is retarded to increase exhaust gas temperature for catalyst warming, the system simultaneously optimizes the fuel injection amount for the last expansion stroke injection to maintain combustion stability and control emissions, preventing excessive soot formation while achieving the desired thermal effect on the catalyst.
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 optimal fuel injection amounts that reduce soot production and ensure proper combustion, maintaining emissions quality and engine performance by adjusting fuel injection dynamically based on temperature and efficiency conditions.
Implementation Method 1
an in-cylinder injection valve configured to spray fuel into a combustion chamber
Implementation Method 2
a spark plug configured to ignite the fuel sprayed from the in-cylinder injection valve
Implementation Method 3
an exhaust gas control device including an exhaust gas control catalyst configured to control exhaust gases from the engine
Data Source
AI summary
An engine device includes an engine including an in-cylinder injection valve and a spark plug, an exhaust gas control device, and a controller. The controller is configured to perform a last fuel injection from the in-cylinder injection valve in an expansion stroke and to set a fuel injection amount for the last fuel injection in expansion stroke injection driving, based on a coolant start temperature, post-start time, and volumetric efficiency. The expansion stroke injection driving is a control that is performed by performing the ignition by the spark plug in synchronization with the fuel injection in the expansion stroke.