Engine Fuel Injection Control for Stable Combustion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In internal combustion engines with both port and cylinder injection valves, the intake-air port cools more than the cylinder during a fuel cut, leading to unstable combustion when the same fuel increase amount is used for both, as the port injection and cylinder injection after the fuel cut.
Innovation Solution
A control apparatus that adjusts the fuel increase amount corrections for the port and cylinder injection valves differently based on the duration of the fuel cut, with the port increase amount correction being greater than the cylinder increase amount correction, and switching between these corrections over time as the injection mode changes, to stabilize combustion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the same fuel increase amount correction is used for both port injection and cylinder injection after fuel cut, then the control is simplified, but combustion becomes unstable due to temperature differences between the intake-air port and cylinder
Solution Approach 1:
The patent applies different fuel increase amount corrections to the port injection and cylinder injection based on their respective temperature characteristics. The port injection receives a larger correction value because the intake-air port cools more than the cylinder during fuel cut. This local differentiation of control parameters resolves the contradiction by maintaining combustion stability through customized control for each injection type.
2Reliability
If the fuel increase amount correction is increased for longer fuel cut duration, then combustion stability is improved, but the risk of excessive fuel injection and misfire increases
Solution Approach 1:
The patent dynamically adjusts the fuel increase amount correction based on the fuel cut duration parameter. As the fuel cut duration increases, the correction value increases to compensate for greater cooling effects. This parameter-based adjustment resolves the contradiction by providing adaptive control that maintains combustion stability without causing excessive fuel injection, as the correction is precisely tailored to the actual operating conditions.
3Reliability
If the port increase amount correction is set greater than the cylinder increase amount correction, then combustion stability is improved by compensating for port cooling, but the control logic becomes more complex
Solution Approach 1:
The patent implements different correction values for port and cylinder injections by establishing separate correction maps or calculation formulas. The port injection correction is set greater than the cylinder injection correction to account for the larger temperature drop in the intake-air port. This local quality approach resolves the contradiction by providing targeted compensation for each injection type's specific thermal characteristics.
Solution Approach 2:
The patent pre-calculates and stores the fuel increase amount corrections in lookup tables or maps before actual fuel injection occurs. These correction values are determined based on anticipated fuel cut durations and injection types. This preliminary preparation resolves the contradiction by simplifying real-time control logic while maintaining accurate, stability-oriented correction values.
Data Source
AI summary
A control apparatus of an internal combustion engine is provided. The internal combustion engine includes a port injection valve that injects fuel into an intake-air port, and a cylinder injection valve that injects fuel into a cylinder. The control apparatus includes an electronic control unit that controls the port injection valve and the cylinder injection valve such that when returning from a fuel cut, a value of a port increase amount correction, which is a fuel increase amount correction in which a fuel amount is decreased with a lapse of time during a port injection, differs from a value of a cylinder increase amount correction, which is a fuel increase amount correction in which a fuel amount is decreased with a lapse of time during a cylinder injection.