Engine Controller Pre-Ignition Prevention Injection Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In vehicle engines, pre-ignition occurs due to hotspots like the ignition plug and exhaust valve, causing abnormal combustion, which existing engine controllers attempt to mitigate by increasing fuel injection or advancing ignition timing, but these methods deteriorate fuel efficiency and discharge capability.
Innovation Solution
An engine controller with control circuitry that performs a pre-ignition prevention injection process by dividing the fuel injection period into a first and second injection period, avoiding the time when pre-ignition is likely to occur, based on engine torque, coolant temperature, and fuel injection pressure, to prevent fuel from being injected during high-risk periods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fuel injection amount is increased or ignition timing is advanced to suppress pre-ignition, then pre-ignition is reduced, but fuel efficiency and discharge capability deteriorate
Solution Approach 1:
The fuel injection period is divided into multiple injection periods (first injection period before compression stroke, second injection period after intake valve closes). This segmentation allows selective fuel injection in safe periods while avoiding the high-risk period when the intake valve is open during compression stroke, thus preventing pre-ignition without requiring excessive fuel injection that would harm fuel efficiency.
2Quantity of substance
If fuel is injected during the period from compression stroke start to intake valve close, then fuel injection amount is sufficient, but pre-ignition is likely to occur
Solution Approach 1:
Fuel injection is performed in advance during the first injection period (before compression stroke starts) and completed after the second injection period (after intake valve closes). This preliminary action ensures fuel is injected before the harmful period begins and after the harmful period ends, avoiding pre-ignition while maintaining sufficient fuel quantity.
3Productivity
If the intake valve closes after the compression stroke starts, then discharge capability is improved, but the period for fuel injection is reduced
Solution Approach 1:
The fuel injection process is segmented into two distinct periods: the first injection period before the compression stroke starts and the second injection period after the intake valve closes. This segmentation allows the intake valve to close after compression stroke start (improving discharge capability) while still providing sufficient fuel injection time through the first period, effectively resolving the conflict between valve timing and injection duration.
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 effectively prevents pre-ignition without deteriorating fuel efficiency or discharge capability, by accurately determining when pre-ignition is likely to occur and adjusting the injection timing accordingly, thereby maintaining engine performance.
Implementation Method 1
When the intake valve is open, the intake air in the cylinder is discharged to the intake port. This generates an upward air flow in the cylinder. When the fuel is injected from the injector during a period in which such an air flow is generated in the cylinder, the fuel spray rides on the air flow and is directed upward in the cylinder.
Implementation Method 2
If the temperatures of the exhaust valve, the ignition plug, and the like is relatively high, the fuel spray comes into contact with the exhaust valve, the ignition plug, and the like having a relatively high temperature to ignite the fuel spray, which may cause pre-ignition.
Data Source
AI summary
An engine controller, an engine control method, and a storage medium are provided. An intake valve closes after a compression stroke starts. One of a predetermined period before the compression stroke starts and a predetermined period after the intake valve closes is a first injection period and the other one is a second injection period. A pre-ignition prevention injection process controls an injector such that fuel corresponding to a requested injection amount is injected by dividing an injection period into the first injection period and the second injection period when a period required for fuel injection corresponding to the requested injection amount is longer than the first injection period.