Engine Control Device Adjusting Injection Timing for High Compression Ratio
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In engines with a compression ratio variable mechanism and direct fuel injection, fuel easily adheres to the piston crown surface at high compression ratios, leading to increased particulate matter (PM) emissions due to the reduced distance between the piston and the fuel injector.
Innovation Solution
A control device and method that adjust the fuel injector's injection timing to be away from the top dead center as the compression ratio increases, using a controller to manage the compression ratio variable mechanism and fuel injector settings to maintain an adequate distance and reduce fuel adherence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the compression ratio is increased to improve engine efficiency, then power output is improved, but the distance between the piston and fuel injector is reduced causing fuel to adhere to the piston crown surface and increasing PM emissions
Solution Approach 1:
The patent applies dynamics by making the injection timing variable rather than fixed. The injection timing is dynamically adjusted based on the compression ratio, specifically being set away from the top dead center position when compression ratio increases. This dynamic adjustment prevents fuel from adhering to the piston crown surface while maintaining the benefits of high compression ratio operation.
Solution Approach 2:
The patent changes the injection timing parameter in response to compression ratio changes. By modifying the injection timing parameter to be away from the top dead center position when compression ratio increases, the system prevents fuel adherence to the piston crown surface, thereby reducing PM emissions while maintaining high compression ratio for improved power output.
2Use of energy by moving object
If the compression ratio is increased to improve combustion efficiency, then fuel economy is improved, but fuel adherence to the piston crown surface increases leading to higher PM emissions
Solution Approach 1:
The injection timing is dynamically adjusted based on compression ratio conditions. When compression ratio increases to improve fuel economy, the injection timing is simultaneously adjusted to be away from the top dead center position, preventing fuel adherence and the associated PM emissions while maintaining the fuel economy benefits.
Solution Approach 2:
The injection timing parameter is changed in response to compression ratio changes. By setting the injection timing away from the top dead center position when compression ratio increases, the system achieves improved fuel economy through higher compression ratio while preventing fuel adherence and PM emissions through parameter adjustment.
3Productivity
If the injection timing is set close to the top dead center to improve combustion efficiency, then combustion efficiency is improved, but fuel adheres to the piston crown surface increasing PM emissions
Solution Approach 1:
The injection timing parameter is adjusted based on compression ratio conditions. When compression ratio increases, the injection timing is set away from the top dead center position, preventing fuel adherence to the piston crown surface and reducing PM emissions while maintaining acceptable combustion efficiency.
Data Source
AI summary
The present invention relates to a control device and a control method for an engine that includes a compression ratio variable mechanism for changing a top dead center position of a piston and a fuel injector for directly injecting a fuel into a cylinder. In the control device and the control method for the engine according to the invention, when a compression ratio is increased by the compression ratio variable mechanism, an injection timing, a fuel pressure, the number of times of split injections, and the like, in a fuel injection of the fuel injector are changed, to reduce a fuel adhering to a piston crown surface.