Internal Combustion Engine Fuel Injection Control for PM Reduction
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Solution Overview
Problem
Existing fuel injection control devices for internal combustion engines struggle to effectively limit particulate matter (PM) generation at low temperatures, as current methods do not adequately account for temperature and load conditions, leading to increased PM formation due to fuel droplets entering the combustion chamber.
Innovation Solution
A control device that executes a multiple injection process, splitting the fuel injection into asynchronous and synchronous injections based on engine load and temperature, with the synchronous injection amount increasing and asynchronous injection amount decreasing at low temperatures to reduce fuel accumulation on the intake passage, thereby minimizing PM generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the requested injection amount is all injected with the intake asynchronous injection when the temperature of the internal combustion engine is low, then the fuel injection is simplified, but the number (PN) of particulate matter (PM) increases depending on load
Solution Approach 1:
The fuel injection is segmented into two distinct phases: intake asynchronous injection (injecting fuel before the intake valve opens) and intake synchronous injection (injecting fuel when the intake valve is open). This segmentation allows the system to reduce fuel accumulation on the intake passage by injecting some fuel directly into the combustion chamber, thereby reducing PM generation while maintaining manageable injection process complexity
Solution Approach 2:
The injection strategy dynamically adjusts based on engine temperature and load conditions. When engine temperature is low and load is high, the system switches from single asynchronous injection to dual injection mode, dynamically adapting the injection approach to environmental conditions to minimize PM generation
2Quantity of substance
If the amount of fuel collecting on the intake passage increases, then the fuel injection amount is increased, but shearing the collected fuel causes some of the collected fuel to flow into the combustion chamber in a state in which they remain droplets, thereby generating PM
Solution Approach 1:
The system extracts a portion of the requested injection amount from the asynchronous injection and transfers it to synchronous injection. By taking out this portion and injecting it directly into the combustion chamber when the intake valve is open, the system prevents fuel accumulation on the intake passage and eliminates the harmful effect of droplet formation from sheared fuel
Solution Approach 2:
The intake synchronous injection acts as an intermediary mechanism that bridges the gap between fuel delivery and combustion. By introducing this intermediate injection phase, the system provides a controlled pathway for fuel to enter the combustion chamber directly as atomized spray rather than as accumulated droplets on the intake passage
3Quantity of substance
If the synchronous injection amount increases, then the fuel accumulation on the intake passage is reduced, but PN increases on the contrary
Solution Approach 1:
The system changes the parameter of injection timing by introducing synchronous injection that occurs when the intake valve is open, as opposed to only asynchronous injection before valve opening. This parameter change in timing allows fuel to be injected directly into the combustion chamber under controlled conditions, optimizing the balance between reducing fuel accumulation and minimizing PM generation
Data Source
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AI summary
A port injection valve (16) injects fuel to an intake passage (12). In multiple injection processing, a demanded injection quantity (Qd) of the fuel is divided into a synchronous injection quantity (Qs) and a non-synchronous injection quantity (Qns) in accordance with at least one of: the load (Qd), which is a physical quantity having a correlation with the amount of air (NE, Ga) to be filled; and the temperature (THW) of an internal-combustion engine (10). The fuel is injected through intake non-synchronous injection and intake synchronous injection in this order. In the intake synchronous injection, the fuel is injected synchronously with a valve-open period of an intake valve (18). In the intake non-synchronous injection, the fuel is injected at a timing more advanced than in the intake synchronous injection.