Direct Injection Engine Fuel Distribution and Intake Timing Control
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Solution Overview
Problem
Existing direct injection engines face challenges in reducing cooling loss due to contact of combustion gas with the wall surface of the combustion chamber, which complicates the engine structure and increases costs, and fail to effectively avoid contact of the fuel-air mixture with the wall surface during low engine load conditions.
Innovation Solution
A direct injection engine design featuring an intake port on the ceiling surface of the combustion chamber, an intake valve, a fuel injection valve, and a control system that adjusts the intake valve's closing timing and fuel injection pattern to create a higher fuel concentration in the middle portion of the combustion chamber than the outer peripheral portion during low load conditions, and advances the intake valve closing timing as engine speed increases, directing intake air back towards the intake port.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If ozone generation device is installed in intake pipe to add ozone to intake air, then combustion speed is increased and cooling loss is reduced, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent removes the ozone generation device from the intake system and instead extracts the essential function of rapid combustion through direct fuel injection into the combustion chamber. The fuel injection valve directly introduces fuel near the ceiling surface, eliminating the need for external ozone generation equipment while achieving fast combustion rates.
Solution Approach 2:
The patent replaces the mechanical/chemical ozone generation system with a controlled fuel injection system. By injecting fuel directly into the combustion chamber in a specific location and timing, the system achieves rapid combustion without requiring ozone generation equipment, substituting a simpler mechanical injection system for a complex chemical generation system.
2Power
If fuel-air mixture is generated in the vicinity of the wall surface of the combustion chamber, then combustion can occur, but contact of combustion gas with the wall surface increases cooling loss
Solution Approach 1:
The patent applies local quality by creating different fuel concentration zones within the combustion chamber. Fuel is injected to create a high-concentration zone in the central region away from wall surfaces, while peripheral regions near the walls maintain lower fuel concentrations. This spatial differentiation ensures combustion occurs in the fuel-rich central zone while minimizing combustion gas contact with cooler wall surfaces.
Solution Approach 2:
The patent utilizes the spatial dimension within the combustion chamber by positioning the fuel injection point and creating a three-dimensional fuel distribution pattern. Fuel is introduced from the ceiling surface area and distributes downward and outward, creating a volumetric combustion zone that is spatially separated from the wall surfaces, thereby reducing heat transfer to walls while maintaining combustion.
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 configuration effectively reduces cooling loss by minimizing contact between combustion gas and the wall surface, enhancing fuel economy while maintaining a simplified engine structure and reducing energy wastage.
Implementation Method 1
a fuel injection valve mounted on the ceiling surface of the combustion chamber, and configured to inject fuel toward a crown surface of the piston
Implementation Method 2
an intake valve configured to open and close an opening portion of the intake port
Implementation Method 3
cooling loss accompanied by release of heat energy of combustion gas from a wall surface of a combustion chamber to the outside of the engine
Data Source
AI summary
A fuel injection valve is caused to inject fuel in a latter half of a compression stroke in such a manner that a fuel concentration immediately before start of combustion is higher in a middle portion of a combustion chamber than in an outer peripheral portion thereof in a low load range where the engine load is lower than a predetermined set reference load. An intake valve driving device is controlled in such a manner that an intake valve closing timing in the low load range is advanced on a retard side with respect to an intake bottom dead center in a case where the engine speed is high, as compared with a case where the engine speed is low, and intake air within a cylinder is blown back toward an intake port at least in a range where the engine speed is low.