Multi-Cylinder Engine Intake Structure for Uniform EGR Distribution
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Solution Overview
Problem
In multi-cylinder engines performing EGR, insufficient diffusion of EGR gas leads to variations in EGR rates among cylinders, causing deterioration in exhaust emissions, and existing configurations are complex and costly.
Innovation Solution
A multi-cylinder engine intake structure with a fresh air distribution chamber and a gas collection chamber, where air and EGR gas are introduced to merge and form mixture gas, which is then distributed uniformly to intake ports, using a simple configuration that omits separate intake manifolds and utilizes a collector to facilitate mixing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If EGR gas is introduced into the intake chamber using a conventional exhaust distribution chamber, then mixing of air and EGR gas is facilitated, but the structure of the intake manifold becomes complex and cost increases
Solution Approach 1:
The patent combines the fresh air distribution chamber and gas collection chamber into a single integrated chamber structure. The side wall of the fresh air distribution chamber serves as the bottom wall of the gas collection chamber, eliminating the need for separate intake manifolds and complex distribution chambers while maintaining effective mixing of air and EGR gas.
Solution Approach 2:
The integrated chamber performs multiple functions simultaneously: it distributes fresh air to multiple cylinders through distribution openings, collects EGR gas through dedicated inlets, and facilitates mixing of air and EGR gas within the same space. This multi-functional design simplifies the overall intake system structure.
2Productivity
If air and EGR gas are merged in the intake chamber, then mixture gas is generated, but insufficiently-mixed mixture gas may flow into individual intake ports causing variation in EGR rates
Solution Approach 1:
The gas collection chamber is divided into distinct functional regions: a first mixture region where air and EGR gas initially mix, a communication region that distributes the mixture, and a second mixture region for further mixing. This segmentation ensures progressive and uniform mixing before gas reaches the distribution openings.
Solution Approach 2:
The chamber design ensures that air and EGR gas are pre-mixed in the first mixture region and communication region before reaching the fresh air distribution openings. EGR gas inlets are positioned to introduce exhaust gas into the mixture region upstream of the distribution openings, allowing sufficient mixing time and distance to achieve uniform composition.
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 ensures nearly uniform distribution of EGR gas to individual cylinders, reducing exhaust emission variations and simplifying the engine structure while maintaining effective mixing, thus suppressing deterioration in exhaust emissions.
Implementation Method 1
insufficient diffusion of EGR gas leads to variations in EGR rates
Implementation Method 2
air and EGR gas are introduced to merge and form mixture gas
Implementation Method 3
first mixture region being located on an upstream side relative to the communication region along a flowing direction of mixture gas, the second mixture region being located on a downstream side
Data Source
AI summary
This multi-cylinder engine intake structure is provided with a fresh air distribution chamber into which a plurality of fresh air distribution openings communicating with the individual intake ports are opened, and a gas collection chamber. The gas collection chamber includes a communication region into which a first communication opening communicating with the fresh air distribution chamber is opened, a first mixture region into which an air inlet and an EGR gas inlet are opened and which is positioned upstream of the communication region in a flow direction of a mixture gas of air and EGR gas, and a second mixture region positioned downstream of the communication region in the flow direction of the mixture gas.