Internal Combustion Engine Cylinder Deactivation Substoichiometric Ratio
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Solution Overview
Problem
Existing methods for reducing drive torque in internal combustion engines, such as adjusting ignition time and cylinder deactivation, lead to excessive oxygen in exhaust gases, which reduces the effectiveness of exhaust gas purification devices like catalytic converters, particularly in reducing nitrogen oxide emissions.
Innovation Solution
Implementing a substoichiometric fuel/oxygen ratio by increasing the fuel supply to remaining operational cylinders during cylinder deactivation, while maintaining a stoichiometric composition over time by adjusting fuel and oxygen supply, to create a deficiency of oxygen in exhaust gases, thereby enhancing the conversion efficiency of pollutants in purification devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If cylinder deactivation is performed by suspending fuel injection, then drive torque is reduced, but oxygen content in exhaust gas increases excessively
Solution Approach 1:
The invention changes the fuel-to-oxygen ratio parameter in the operational cylinders from stoichiometric to substoichiometric during cylinder deactivation. This parameter change ensures that while one or more cylinders are deactivated (reducing drive torque), the remaining operational cylinders produce exhaust gas with reduced oxygen content, maintaining effectiveness of the catalytic converter.
2Object-generated harmful factors
If excess oxygen is present in exhaust gas during cylinder deactivation, then catalytic converter effectiveness is reduced
Solution Approach 1:
The invention applies parameter changes by adjusting the fuel injection quantity in operational cylinders to create a substoichiometric air-fuel ratio. This reduces the oxygen content in exhaust gas from deactivated cylinders, thereby maintaining the catalytic converter's ability to effectively reduce nitrogen oxide emissions.
Solution Approach 2:
The invention uses the operational cylinders as intermediaries to compensate for the oxygen excess from deactivated cylinders. By adjusting the fuel injection in these intermediary operational cylinders, the overall exhaust gas composition is controlled to maintain catalytic converter effectiveness.
3Power
If fuel injection is suspended in deactivated cylinders, then drive torque reduction is achieved, but pollutant conversion efficiency decreases
Solution Approach 1:
The invention changes the operating parameter of the remaining cylinders from stoichiometric to substoichiometric fuel/oxygen ratio. This ensures that even though some cylinders are deactivated for torque reduction, the exhaust gas from active cylinders has optimized composition for catalytic conversion, maintaining pollutant conversion efficiency.
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 reduces nitrogen oxide emissions and ensures effective conversion of pollutants in exhaust gas purification devices by maintaining a balanced fuel/oxygen ratio, even during cylinder deactivation, thereby improving the overall emission control and operational stability of the internal combustion engine.
Implementation Method 1
an internal combustion engine with a plurality of cylinders... in order to reduce the drive torque further, at least one cylinder, which is to be deactivated, of the plurality of cylinders is deactivated by suspending a fuel injection into the cylinder
Implementation Method 2
exhaust gas purification devices like catalytic converters... ensures effective conversion of pollutants in purification devices
Data Source
AI summary
An internal combustion engine with a plurality of cylinders is a drive device in which the drive torque available can be reduced. The ignition timing which is set at the internal combustion engine is adjusted in the retarded direction starting from an initial ignition timing until the ignition timing corresponds to a threshold ignition timing. To reduce the drive torque further, at least one cylinder, among the plurality of cylinders, is deactivated by suspending fuel injection into the cylinder, and the remaining cylinder(s) continue to be operated with fuel injection using the ignition timing. The remaining cylinders of the internal combustion engine which continue to be operated are supplied with a quantity of fuel which is larger in comparison with an initial quantity of fuel present before the cylinder deactivation, to set a substoichiometric fuel/oxygen ratio.