Intake Stroke Fuel Injection for Early Catalyst Activation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Internal combustion engines face challenges in activating exhaust purifying catalysts early without the need for direct-injection injectors, which are expensive and prone to high-temperature and high-pressure issues, and result in power loss and carbon deposits.
Innovation Solution
An internal combustion engine design that injects fuel into the intake passage using an injector during the intake stroke, forming a stratified air-fuel mixture and controlling the injection to ensure the catalyst is activated early without a direct-injection injector, utilizing the latent heat of vaporization for cooling and promoting oxidization reactions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a direct-injection injector is mounted within a cylinder to enable stratified lean burn and early catalyst activation, then fuel consumption is reduced and catalyst activation is improved, but the injector is exposed to high-temperature and high-pressure combustion gas requiring expensive temperature and pressure resistance measures
Solution Approach 1:
The injection device is extracted from the cylinder interior and relocated to the intake passage. This removes the injector from the high-temperature and high-pressure combustion environment while maintaining its fuel injection function. The intake passage location provides a cooler, lower-pressure environment that eliminates the need for expensive temperature and pressure resistance measures.
Solution Approach 2:
The intake passage serves as an intermediary medium to deliver fuel to the cylinder. Instead of injecting fuel directly into the combustion chamber, the system uses the intake passage as a buffer zone where fuel can be injected under milder conditions and then carried into the cylinder by the intake air flow.
2Productivity
If high-pressure fuel injection is used from a direct-injection injector to achieve stratified lean burn, then combustion efficiency is improved, but power loss from the high-pressure pump affects performance
Solution Approach 1:
The high-pressure fuel injection system is extracted and replaced with a lower-pressure injection system in the intake passage. The fuel injection device in the intake passage operates at lower pressure, eliminating the need for a high-pressure pump and its associated power losses.
Solution Approach 2:
The system uses pneumatic principles by utilizing the intake air flow to carry fuel into the cylinder. The kinetic energy of the intake air serves as the driving force for fuel delivery, replacing the need for high-pressure mechanical pumping.
3Productivity
If fuel is injected directly into the cylinder to form a stratified air-fuel mixture, then combustion performance is improved, but carbon deposits accumulate inside the cylinder requiring maintenance measures
Solution Approach 1:
The fuel injection location is extracted from the cylinder interior and moved to the intake passage. This prevents direct contact between injected fuel and the cylinder walls, thereby preventing carbon deposit formation on piston crowns and cylinder surfaces.
Solution Approach 2:
The system converts the potential harm of fuel contact with cylinder surfaces into a benefit by using the intake passage as an injection location. The fuel is atomized and mixed with intake air before entering the cylinder, ensuring complete combustion and preventing deposit formation.
4Productivity
If fuel injection timing is delayed to allow intake valve closing, then fuel is trapped in the cylinder for combustion, but fuel adhesion to intake valve and port occurs reducing efficiency
Solution Approach 1:
Fuel injection is performed preliminarily during the intake stroke before the intake valve closes. The fuel is injected early and carried into the cylinder by the continuing intake air flow, ensuring complete fuel delivery before valve closure without requiring delayed injection timing.
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 solution allows early activation of the exhaust purifying catalyst, reduces the need for high-pressure fuel injection, minimizes power loss, and prevents fuel adhesion, thereby enhancing engine performance and reducing carbon deposits.
Implementation Method 1
the latent heat of vaporization of the fuel can be utilized for cooling the intake air
Implementation Method 2
combusts the fuel through the sub-injection, utilizing the spark propagation of the main combustion, to raise the temperature of the exhaust gas
Implementation Method 3
an oxidization reaction in the latter half of an expansion stroke within a cylinder, an oxidization reaction within an exhaust pipe, and an oxidization reaction of the exhaust purifying catalyst are promoted
Data Source
Figure 1
Figure 2
Figure 3
AI summary
In an internal combustion engine, an injector injects fuel into an intake passage, an intake opening communicates the intake passage an inside of a cylinder, a fuel injection means includes at least an intake stroke injection means which causes the injector to inject fuel during an intake stroke, and an injection control means controls the intake stroke injection means to inject fuel from the injector during the intake stroke and introduce fuel into the cylinder from the intake opening, thereby forming a stratified air-fuel mixture within the cylinder, in a state where a temperature of an exhaust purifying catalyst is lower than or equal to a predetermined temperature. The control means operates the intake stroke injection means to inject fuel such that a center of a fuel injection period from the injector is located before displacement speed of an intake valve in a closing direction occurs.