Stratified-Charge SI Engine With Outward-Opening Injector Control
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Solution Overview
Problem
Existing spark-ignition internal combustion engines face challenges in achieving high combustion efficiency and reducing harmful emissions across various operating conditions, particularly due to losses from air/fuel mixture contact with cylinder walls.
Innovation Solution
A spark-ignition engine design with central fuel injection and variable intake valve actuation, utilizing outwardly opening injectors and swirl/tumble motions to create a stoichiometric mixture near the spark plug and an ultra-lean mixture near the cylinder walls, minimizing wall contact and optimizing combustion efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional fuel injection systems are used, then fuel can be injected into the combustion chamber, but the injector must be positioned deep within the combustion chamber requiring a long piston stroke and complex positioning mechanisms
Solution Approach 1:
Instead of positioning the injector deep within the combustion chamber and moving it along a complex trajectory, the patent inverts the approach by placing the injector in the normal combustion position and using a long piston stroke to deliver fuel directly into the combustion chamber. This eliminates the need for complex injector positioning mechanisms while maintaining effective fuel injection.
2Ease of operation
If the piston stroke is made longer to accommodate deep injector positioning, then fuel injection can be achieved, but the engine displacement increases
Solution Approach 1:
The patent avoids increasing engine displacement by inverting the conventional approach. Rather than using a long piston stroke to reach deep injectors, the system uses a standard piston stroke with the injector positioned normally in the combustion chamber, achieving fuel injection without the volume penalty of extended piston travel.
3Extent of automation
If conventional fuel injection timing is used, then fuel can be injected, but precise control of fuel injection timing relative to spark ignition is difficult
Solution Approach 1:
The patent implements feedback control by using a crankshaft position sensor to detect the precise position of the crankshaft and camshaft, and a spark plug position sensor to detect the position of the spark plug. This feedback information is fed to the control unit, which adjusts the fuel injection timing accordingly, enabling precise control of fuel injection relative to spark ignition.
Solution Approach 2:
The patent replaces mechanical timing mechanisms with electronic control. Instead of relying on mechanical linkages to synchronize fuel injection with the combustion cycle, the system uses electronic sensors and a control unit to precisely timing fuel injection based on real-time position data from the crankshaft and spark plug sensors.
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 engine achieves high combustion efficiency and reduced emissions by minimizing heat losses and particulate formation, ensuring robust combustion across all operating conditions with optimized fuel distribution and intake valve control.
Implementation Method 1
the fuel injector is positioned in a normal position in the combustion chamber and a long piston stroke is used to deliver the fuel into the combustion chamber
Implementation Method 2
the spark plug is positioned such that the tip of the spark plug is positioned closer to the combustion chamber wall than the tip of the fuel injector
Implementation Method 3
Stratified-charge, spark-ignition internal combustion engine
Data Source
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AI summary
A spark-ignition internal combustion engine includes, for each cylinder, two intake valves (VA, VB), at least one fuel injector and a spark plug. The two inlet valves (VA, VB) are actuated by an electronically controlled hydraulic actuation device (8) or by a device with electromagnetic or electropneumatic actuators. The actuation device is configured to carry out, in each operating cycle of the cylinder, at least under certain operating conditions of the engine, a first opening period, in which both the intake valves (VA, VB) open when the piston of the respective cylinder is in proximity of the TDC and close when the piston is at an intermediate point in the descent from TDC to BDC, and a second opening period, in which only one intake valve (VA) opens when the piston of the respective cylinder is in proximity of the BDC and closes when the piston is ascending from BDC to TDC. In the second opening period, the second intake valve (VB) remains closed. The fuel supply system is configured to perform at least one fuel injection, in each operating cycle of each cylinder, through an injector arranged in the center of the combustion chamber and having an injector needle (109) with a cone-shaped terminal head (109A) cooperating with an outlet (108) of the injector nozzle (103) and movable outwardly, away from the outlet (108) to allow fuel injection into the cylinder.