Engine Combustion Mode Switching Control for Torque Stability
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Solution Overview
Problem
Existing internal combustion engine technologies face challenges in suppressing torque variation and exhaust emission deterioration when switching from spark ignition to compression ignition combustion modes, leading to increased NOx emissions.
Innovation Solution
A control apparatus and method that sets specific operation areas for spark ignition and compression ignition modes, using combustion state detection and variable valve mechanisms to selectively switch between modes based on operation conditions, ensuring stable combustion and minimizing torque variation and emission deterioration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the combustion mode is switched from spark ignition to compression ignition, then fuel efficiency is improved, but torque variation occurs and exhaust emission deteriorates
Solution Approach 1:
The patent changes the operational parameters by defining specific switching criteria based on engine speed and load conditions. The ECU monitors these parameters and only switches from spark ignition to compression ignition when predetermined conditions are met, thereby maintaining torque stability while achieving fuel efficiency improvements.
Solution Approach 2:
The system dynamically adjusts the combustion mode based on real-time engine operating conditions. The ECU continuously monitors engine speed and load, and selectively switches between spark ignition and compression ignition modes to optimize both fuel efficiency and torque stability according to the current operational state.
2Use of energy by moving object
If the combustion mode is switched from spark ignition to compression ignition, then fuel efficiency is improved, but NOx emissions increase
Solution Approach 1:
The patent controls NOx emissions by changing the operational parameters of combustion mode selection. The ECU monitors engine speed and load conditions and only switches to compression ignition mode when predetermined conditions are satisfied, thereby reducing NOx emissions while maintaining fuel efficiency benefits.
3Reliability
If stratified charge combustion mode is used during switching, then torque variation is suppressed, but NOx emissions increase
Solution Approach 1:
The patent resolves this contradiction by changing the control parameters for mode switching. Instead of always using stratified charge combustion during switching, the ECU selectively switches between combustion modes based on monitored engine speed and load conditions, thereby suppressing torque variation while controlling NOx emissions.
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
The solution effectively reduces torque variation and suppresses exhaust emission deterioration by continuously controlling the spark ignition mode within defined operation conditions, even when switching to compression ignition, thereby maintaining efficient engine operation.
Implementation Method 1
a compression ignition combustion mode in which the air-fuel mixture is self-ignited by piston compression
Implementation Method 2
a spark ignition combustion mode in which an air-fuel mixture is spark-ignited by means of an igniter
Data Source
AI summary
A control apparatus of an engine having a compression ignition combustion mode and a spark ignition combustion mode selects the spark ignition combustion mode when operation conditions fall within a spark ignition operation area set in a spark ignition operation area/compression ignition operation area setting map memory part and selects the compression ignition combustion mode when the operation conditions fall within a switching stable area set in the memory part upon operation by the spark ignition combustion mode. The control apparatus controls to continue the compression ignition combustion mode as long as the operation conditions fall within a compression ignition operation area set in the memory part upon operation by the compression ignition combustion mode.