Tapered Fuel Injector Insert Device for Combustion Mixing
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Solution Overview
Problem
Compression ignition engines face challenges with soot production due to sub-optimal fuel-and-air mix ratios and mechanical stress on insert devices caused by thermal expansion differences, leading to reduced engine performance and potential emissions issues.
Innovation Solution
The development of insert devices that mix fuel and air before injection into engine cylinders, featuring a tapered design to reduce thermal stress and include conduits for precise alignment with fuel injectors, which also act as a heat sink to delay ignition and reduce soot formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If insert devices are placed between fuel injectors and combustion chambers to mix fuel and air, then fuel-and-air mixing is improved and soot production is reduced, but mechanical stress increases due to thermal expansion differences
Solution Approach 1:
The insert device incorporates a tapered portion that utilizes differential thermal expansion between the insert device material and cylinder head material. As temperature increases, the tapered geometry allows the insert device to expand differently than the cylinder head, creating a self-adjusting interference fit that maintains connection while accommodating thermal stresses.
Solution Approach 2:
The insert device changes its dimensional parameters through thermal expansion, with the tapered portion's geometry allowing for controlled expansion that reduces mechanical stress. The interference fit parameters are designed to accommodate thermal growth while maintaining secure connection.
2Volume of moving object
If the insert device is positioned close to the fuel injector, then compact design is achieved, but alignment between conduits and fuel injector holes becomes difficult
Solution Approach 1:
The insert device employs an asymmetric tapered portion with specific geometric features that provide natural alignment cues. The non-uniform taper creates a unique orientation that guides the conduits into proper alignment with the fuel injector holes during installation, eliminating the need for complex alignment procedures.
Solution Approach 2:
The tapered geometry of the insert device provides self-aligning features that automatically orient the conduits correctly with the fuel injector holes. The asymmetric shape ensures proper positioning without requiring external alignment tools or complex installation procedures.
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 insert devices improve fuel-and-air mixing, delay ignition, reduce soot production, and extend the lifespan of engine components by mitigating thermal stress, thereby enhancing engine performance and compliance with emissions regulations.
Implementation Method 1
These insert devices can be exposed to extreme temperatures, which can introduce mechanical stress to the insert devices due to these devices having different coefficients of thermal expansion (CTE) than the cylinder heads to which the insert devices are coupled
Implementation Method 2
The second mixing body includes conduits configured to receive fuel output by the fuel injector and air from the combustion chamber, combine the fuel with the air into a fuel-air mixture
Implementation Method 3
The conduits can be difficult to align with holes in the fuel injectors from which the fuel is ejected due to the small distances between the fuel injectors and the insert devices
Data Source
AI summary
An insert device includes a first coupling body inserted into an engine cylinder head. The first coupling body extends around a center axis to define a first interior volume of the first coupling body that is shaped to receive a distal tip of a fuel injector. The insert device includes a second mixing body coupled with the first coupling body and extending around the center axis. The second mixing body includes conduits that receive fuel from the fuel injector and air from a combustion chamber, combine the fuel with the air, and direct the fuel-air mixture into the combustion chamber. The first coupling body has a first end surface positioned to face the cylinder head and the first coupling body is tapered such that an outer diameter of the first coupling body is larger toward the first end surface than toward the second mixing body.