Engine Fuel Injector Control for Soot Adhesion
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Solution Overview
Problem
In direct-injection internal combustion engines, existing control apparatuses struggle to effectively suppress soot adhesion to the piston crown surface at low engine temperatures, despite attempts to inject fuel near the theoretical mixing ratio in the latter half of the compression stroke and retarding ignition timing.
Innovation Solution
A control apparatus with an electronic control unit that divides fuel injection into multiple stages at predetermined time intervals from the start of the intake stroke to the end of the compression stroke, adjusting the spray length to be shorter than a single injection, thereby reducing soot adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If fuel is injected at once in the latter half of the compression stroke, then the injection process is simple, but soot adhesion to the piston crown surface increases
Solution Approach 1:
The patent divides the single fuel injection into multiple injections (first injection and second injection) during the compression stroke. The first injection occurs earlier in the compression stroke, and the second injection occurs later, allowing the spray lengths to differ and preventing soot adhesion to the piston crown surface while maintaining injection system simplicity.
2Object-generated harmful factors
If fuel injection is divided into multiple times, then soot adhesion is suppressed, but the control complexity increases
Solution Approach 1:
The patent segments the fuel injection into multiple distinct phases (first injection and second injection) with different timing and spray length characteristics, effectively suppressing soot adhesion while managing control complexity through structured injection control.
Solution Approach 2:
The patent implements periodic fuel injection actions during the compression stroke, with the first injection occurring at an earlier phase and the second injection occurring at a later phase, creating a rhythmic injection pattern that prevents soot formation while maintaining manageable control complexity.
3Stability of the object's composition
If spray length is made longer, then fuel mixing is improved, but soot adhesion to piston crown surface increases
Solution Approach 1:
The patent applies different spray length characteristics to different injection phases: the first injection has a longer spray length for improved fuel mixing, while the second injection has a shorter spray length to prevent soot adhesion to the piston crown surface, achieving both goals through localized quality differentiation.
Solution Approach 2:
The patent segments the fuel injection process into distinct phases with different spray length characteristics, allowing the first injection to achieve good mixing with longer spray while the second injection prevents soot adhesion with shorter spray, resolving the contradiction between mixing and soot prevention.
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 suppresses soot adhesion to the piston crown surface by optimizing fuel injection timing and frequency, improving engine operation and reducing soot formation at low temperatures.
Implementation Method 1
fuel injected from the injector may adhere to the piston crown surface
Implementation Method 2
spray length from a tip of the fuel injector to tip of a spray of the fuel injected from the fuel injector
Data Source
AI summary
An internal combustion engine control apparatus including a microprocessor. The microprocessor is configured to perform controlling a fuel injector so as to inject a fuel of a target injection amount by dividing into a plurality of times at a predetermined time interval in an area from a first crank angle at which an intake stroke is started to a second crank angle at which a compression stroke is ended, and setting the predetermined time interval. The microprocessor is configured to perform the setting including setting the predetermined time interval so that a spray length from a tip of the fuel injector to a tip of a spray of the fuel injected from the fuel injector becomes shorter than the spray length when the fuel of the target injection amount is injected at once in the area by a predetermined rate.