Internal Combustion Engine Injector Nozzle Hole Diameter Configuration
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Solution Overview
Problem
In conventional direct injection-type internal combustion engines, fuel is injected above the center of the vortex in the cylinder, leading to fuel adhesion to the piston and soot generation due to collision with the cylinder sleeve end.
Innovation Solution
The engine design includes an injector with nozzle holes arranged such that the sixth nozzle hole, most deflected toward the piston, has a larger diameter than others, and all nozzle holes are positioned to ensure a specific angle and distance ratio, allowing fuel to stagnate around the vortex center and inhibit adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If fuel is injected above the center of the vortex in the cylinder, then fuel can be delivered to the combustion chamber, but fuel adheres to the piston and causes soot generation due to collision with the cylinder sleeve end
Solution Approach 1:
The patent applies local quality by differentiating the nozzle hole diameters within the injector. Specifically, among multiple nozzle holes, one nozzle hole has a larger diameter than the others, creating localized variation in fuel injection characteristics. This allows different regions of the fuel spray to have different penetration depths and distribution patterns, enabling precise control over where fuel deposits in the combustion chamber while avoiding piston adhesion.
Solution Approach 2:
The patent changes the physical parameter of nozzle hole diameter to optimize fuel injection behavior. By setting one nozzle hole diameter to be larger than others (with the larger diameter corresponding to at least 20% of the total of all nozzle hole diameters), the fuel spray characteristics are modified. This parameter change enables the fuel to be injected more effectively toward the vortex center rather than being carried away by the tumble flow to the piston surface.
2Ease of manufacture
If all nozzle holes have the same diameter, then manufacturing is simplified, but fuel injection distribution cannot be optimized to prevent piston adhesion
Solution Approach 1:
The patent resolves this contradiction by implementing local quality through differentiated nozzle hole diameters. Instead of making all nozzle holes identical (which would be easier to manufacture), one nozzle hole is designed with a larger diameter. This localized variation provides precise control over fuel injection distribution and prevents piston adhesion, while still maintaining relative manufacturing simplicity by having only one different nozzle hole among several.
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 significantly reduces fuel adhesion to the piston and soot generation by directing fuel into the vortex center, preventing it from being carried away by the intake tumble flow.
Implementation Method 1
fuel is injected to a position above the center of a vortex of a swirl flow in the vertical direction (hereinafter referred to as the intake tumble flow) in the cylinder
Implementation Method 2
fuel is directly injected into the cylinder from the fuel injection nozzle
Data Source
AI summary
The present disclosure is intended to provide an internal combustion engine that can inhibit fuel from adhering to a piston and can reduce generation of soot. An internal combustion engine includes a piston, a cylinder accommodating the piston, and an injector including a nozzle that has a plurality of nozzle holes configured to inject fuel into the cylinder from above the cylinder. Among the plurality of nozzle holes, a sixth nozzle hole an axial direction of which is the most deflected toward the piston has a nozzle hole diameter larger than nozzle hole diameters of the other nozzle holes, and the nozzle hole diameter of the sixth nozzle hole corresponds to at least 20% of the total of the nozzle hole diameters of the other nozzle holes.