Vortex Chamber EGR Layout for Stable Exhaust Oxygen Control

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Solution Overview

Problem

Existing engines face challenges in accurately controlling the oxygen concentration in exhaust gas recirculation due to variations in exhaust gas constituents, leading to potential engine misfires and nitrogen oxide generation.

Innovation Solution

The engine incorporates a vortex chamber where exhaust gas collides with a receiving surface to diffuse and average gas constituents, followed by recirculation through an EGR passage, utilizing an oxygen sensor and controller to regulate the exhaust gas flow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the EGR passage is connected directly to the exhaust manifold, then the structure is simple, but the oxygen concentration in the exhaust gas varies and cannot be controlled accurately

Engineering Contradiction:
ImproveEGR passage structureVSAvoidoxygen concentration detection accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

A vortex chamber is introduced as an intermediary component between the exhaust manifold and the EGR passage. The vortex chamber receives exhaust gas from the exhaust manifold and mixes it with fresh air before the gas enters the EGR passage. This intermediary mixing process stabilizes the oxygen concentration in the exhaust gas flowing through the EGR passage, enabling accurate detection and control by the oxygen sensor without requiring complex control mechanisms.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If exhaust gas is recirculated directly from the exhaust manifold, then the recirculation flow rate is high, but engine misfire occurs due to excessive exhaust gas recirculation

Engineering Contradiction:
Improveexhaust gas recirculation flow rateVSAvoidengine operation stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The vortex chamber serves as an intermediary mixing chamber that receives exhaust gas from the exhaust manifold and mixes it with fresh air before the gas enters the EGR passage. This intermediary mixing process stabilizes the oxygen concentration in the exhaust gas flowing through the EGR passage, enabling accurate detection and control by the oxygen sensor without requiring complex control mechanisms.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If the EGR valve is controlled to maintain stable oxygen concentration, then engine misfire is prevented, but the control becomes complex

Engineering Contradiction:
Improveengine operation stabilityVSAvoidEGR valve control complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The vortex chamber is positioned between the exhaust manifold and the EGR passage, creating a buffer zone where exhaust gas mixes with fresh air. This intermediary mixing process naturally stabilizes the oxygen concentration in the exhaust gas before it enters the EGR passage, reducing the control complexity of the EGR valve while maintaining engine operation stability and preventing misfire.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 approach stabilizes oxygen and carbon dioxide concentrations in the air-fuel mixture, preventing engine misfires and undesired nitrogen oxide production while simplifying EGR valve control.

Implementation Method 1

a vortex chamber to which the header pipe is connected; a receiving surface that is formed in the vortex chamber such that the exhaust gas flowing into the vortex chamber from the header pipe collides with the receiving surface to be diffused in the vortex chamber

Methodology Applied
Scientific EffectDiffusion: Diffusion

Data Source

PatentEP4656865A1Internal combustion engine
Publication Date: 2025.12.03 TOYOTA JIDOSHA KK
  • EP4656865A1 patent drawingFigure 1
  • EP4656865A1 patent drawingFigure 2A~2B
  • EP4656865A1 patent drawingFigure 3A~3B

AI summary

An engine configured to prevent a variation in constituents of exhaust gas flowing into an EGR passage. The engine comprises: a header pipe joined to a cylinder; an EGR passage through which exhaust gas emitted from the cylinder is recirculated to an intake pipe; a vortex chamber to which the header pipe is connected; a receiving surface with which the exhaust gas flowing into the vortex chamber collides; an exhaust gas purification device; and a connector pipe connecting the vortex chamber to the exhaust gas purification device. One end of the exhaust gas recirculation passage is joined to the connector pipe.