Fuel Injector Intake Exhaust Port Geometry
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Solution Overview
Problem
Existing fuel injectors face challenges in ensuring complete mixing of fuel with air in internal combustion engines due to differences in inner diameters of intake and exhaust injection ports, leading to uneven fuel distribution and reduced homogeneity of the mixed gas.
Innovation Solution
A fuel injector design with plural injection ports, including intake and exhaust ports, where the intake ports have a straight shape for high penetration and the exhaust ports have an enlarged tapered shape to reduce penetration, allowing for optimal fuel distribution and mixing across the combustion chamber.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the inner diameter of the intake injection port is reduced to improve fuel mixing with high-speed air, then the penetration of the fuel spray decreases, but the fuel cannot enter and mix completely with the air in the intake area
Solution Approach 1:
The fuel injection system is divided into two separate injection ports with different geometries: an intake injection port for injecting fuel into the intake area and an exhaust injection port for injecting fuel into the exhaust area. This segmentation allows each port to be optimized independently for its specific function, resolving the contradiction between spray penetration and fuel-air mixing.
Solution Approach 2:
Different local geometries are applied to different injection ports based on their specific requirements. The intake injection port has a smaller inner diameter and different angle to optimize mixing with high-speed intake air, while the exhaust injection port has a larger inner diameter and different angle to achieve sufficient penetration in the exhaust area. This local quality differentiation resolves the contradiction by allowing each port to have optimal characteristics for its specific operating conditions.
2Length of moving object
If the inner diameter of the exhaust injection port is increased to improve spray penetration, then the fuel can reach deeper into the combustion chamber, but the fuel may go through the air without complete mixing
Solution Approach 1:
The fuel injection system is divided into two separate injection ports with different geometries: an intake injection port for injecting fuel into the intake area and an exhaust injection port for injecting fuel into the exhaust area. This segmentation allows each port to be optimized independently for its specific function, resolving the contradiction between spray penetration and fuel-air mixing.
Solution Approach 2:
Different local geometries are applied to different injection ports based on their specific requirements. The intake injection port has a smaller inner diameter and different angle to optimize mixing with high-speed intake air, while the exhaust injection port has a larger inner diameter and different angle to achieve sufficient penetration in the exhaust area. This local quality differentiation resolves the contradiction by allowing each port to have optimal characteristics for its specific operating conditions.
3Quantity of substance
If the inner diameter of injection ports is adjusted to correct fuel quantity distribution, then the fuel flow quantity changes, but it remains difficult for each injection port to supply optimal fuel quantity in different pointing directions
Solution Approach 1:
Different local geometries are applied to different injection ports based on their specific requirements. The intake injection port has a smaller inner diameter and different angle to optimize mixing with high-speed intake air, while the exhaust injection port has a larger inner diameter and different angle to achieve sufficient penetration in the exhaust area. This local quality differentiation resolves the contradiction by allowing each port to have optimal characteristics for its specific operating conditions.
Solution Approach 2:
The injection ports are designed with asymmetric characteristics - different inner diameters, different pointing directions, and different geometries - to match the asymmetric requirements of the intake and exhaust areas. The intake injection port is optimized for high-speed mixing while the exhaust injection port is optimized for penetration, creating an asymmetric system that adapts to the different flow conditions in each area.
Data Source
AI summary
A fuel injector injecting a fuel toward a combustion chamber mounted to a gasoline engine is provided with plural injection ports through which the fuel is injected. Each injection port includes an injection-port axial line limiting a pointing direction of the injection port, and the injection-port axial lines point to different directions. The injection ports include at least one intake injection port the injection-port axial line of which points to an intake space in the combustion chamber between a top surface of a piston of the internal combustion engine and an intake valve of the internal combustion engine. The intake injection port is defined by an inner peripheral wall surface extending in the injection-port axial line of the intake injection port and having a straight shape. The injection ports further include at least one exhaust injection port the injection-port axial line of which points to an exhaust space in the combustion chamber between the top surface of the piston of the internal combustion engine and an exhaust valve of the internal combustion engine. The exhaust injection port is defined by an inner peripheral wall surface separated from the injection-port axial line of the exhaust injection port toward an outlet opening and having an enlarged shape toward the outlet opening.