Engine Restart Fuel Injection Control for Combustion Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
When an engine is restarted after automatic stop, the combustion state in the cylinder to which fuel is supplied becomes unstable, leading to deteriorated emissions.
Innovation Solution
An engine system with a control device that acquires engine temperature and stop time, adjusts fuel injection amount in non-cut cylinders by correction coefficients for non-contributing fuel and NOx suppression, and controls ignition timing and throttle opening to stabilize combustion and reduce emissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If fuel cut is executed for a specific cylinder during engine restart, then fuel consumption is reduced, but combustion state becomes unstable and emission deteriorates
Solution Approach 1:
The patent applies parameter changes by adjusting the fuel injection amount in non-cut cylinders based on engine temperature and stop time. The control device calculates a correction coefficient that increases fuel injection in active cylinders when the engine has been stopped for a long duration or at low temperatures, ensuring stable combustion while maintaining fuel cut benefits. This dynamic parameter adjustment resolves the contradiction between fuel savings and combustion stability.
2Reliability
If fuel injection amount is increased in non-cut cylinders, then combustion stability is improved, but NOx emission may increase
Solution Approach 1:
The patent uses parameter changes by implementing a correction coefficient that simultaneously addresses combustion stability and NOx suppression. The control device adjusts fuel injection amount and ignition timing in coordination, modifying combustion parameters to achieve stable combustion while controlling peak temperatures that lead to NOx formation. This coordinated parameter adjustment resolves the trade-off between combustion stability and emission quality.
3Reliability
If ignition timing is adjusted according to rotational speed and torque fluctuation, then combustion stability is improved during restart, but control complexity increases
Solution Approach 1:
The patent applies feedback control by continuously monitoring rotational speed and torque fluctuations during engine restart and adjusting ignition timing accordingly. The control device uses real-time feedback from engine operation to dynamically optimize combustion timing, ensuring stable restart performance. This feedback mechanism manages control complexity through algorithmic processing of sensor data to achieve optimal combustion control.
Data Source
AI summary
An engine system includes an engine including first and second cylinders, and a control device configured to execute automatic stop of the engine and restart of the engine. The control device includes an acquisition unit configured to acquire a temperature of the engine and a time during the automatic stop of the engine, a fuel cut control unit configured to execute a specific cylinder fuel cut process for stopping supply of fuel to the first cylinder and for supplying fuel to the second cylinder when there is a request to restart the engine, and an injection amount control unit configured to increase a fuel injection amount in the second cylinder as the time during the automatic stop of the engine is longer and as the temperature of the engine is lower, during execution of the specific cylinder fuel cut process.