Exhaust Protuberance Resonance Reduction Catalyst Converter

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Solution Overview

Problem

Existing methods to reduce resonance in catalyst converters due to exhaust gas flow, such as using Helmholtz resonators, rectification plates, or narrowing exhaust pipes, are not always feasible due to vehicle layout, manufacturing cost, or performance issues.

Innovation Solution

Incorporating a protuberance in the upstream exhaust gas pipe section of the catalyst converter to disturb the exhaust gas flow, reducing pressure pulsation and resonance noise without affecting vehicle layout or increasing manufacturing costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a Helmholtz resonator is used to cancel resonance noise, then resonance noise is reduced, but device complexity and manufacturing cost increase

Engineering Contradiction:
Improveresonance noiseVSAvoiddevice complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The invention extracts the noise-cancellation function from a separate Helmholtz resonator component and integrates it directly into the catalyst converter body. The catalyst converter is designed with a specific cavity structure that inherently functions as a Helmholtz resonator, eliminating the need for additional resonator components while maintaining the noise cancellation effect.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention merges the catalyst converter and Helmholtz resonator into a single integrated component. The catalyst converter body is designed with a specific cavity volume and opening configuration that allows it to simultaneously perform catalysis and acoustic resonance functions, thereby reducing device complexity and manufacturing cost.

Inventive Principle:
Principle #5Merging (Combining)

2Object-affected harmful factors

If a rectification plate is provided in the exhaust gas pipe to reduce pressure pulsation, then resonance is reduced, but device complexity and manufacturing cost increase

Engineering Contradiction:
Improvepressure pulsationVSAvoiddevice complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The invention removes the rectification plate component from the exhaust system and instead incorporates flow straightening features directly into the exhaust gas pipe structure. The pipe is designed with specific internal geometries that naturally reduce pressure pulsation without requiring separate rectification components.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention applies local flow control features at specific locations within the exhaust gas pipe rather than using a comprehensive rectification plate. The pipe cross-section is designed with varying local characteristics (such as stepped configurations or localized protrusions) that target specific pulsation frequencies while maintaining overall system simplicity.

Inventive Principle:
Principle #3Local quality

3Object-affected harmful factors

If the exhaust gas pipe inner diameter is reduced to reduce pressure pulsation, then resonance is reduced, but exhaust gas flow performance deteriorates

Engineering Contradiction:
Improvepressure pulsationVSAvoidexhaust gas flow
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The invention segments the exhaust gas pipe into multiple sections with different diameter characteristics rather than uniformly reducing the diameter throughout. Specific sections have reduced diameters or stepped configurations targeted at particular pulsation frequencies, while other sections maintain larger diameters to preserve overall exhaust flow performance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention changes the geometric parameters of the exhaust gas pipe in a controlled manner to reduce pressure pulsation. The pipe cross-sectional area is varied along its length with specific dimensional changes that target resonance frequencies without causing excessive flow resistance, balancing pulsation reduction with flow performance.

Inventive Principle:
Principle #35Parameter changes

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

Effectively reduces resonance noise in the catalyst converter by disturbing the exhaust gas flow, suppressing abnormal noise generation without adverse effects on vehicle layout or performance, and maintaining manufacturing efficiency.

Implementation Method 1

a protuberance for disturbing the flow of the exhaust gas in the exhaust flow channel so as to reduce a pressure pulsation of the exhaust gas

Methodology Applied
Scientific EffectFlow disturbance: Turbulence

Data Source

PatentEP2846016B1Internal combustion engine
Publication Date: 2019.06.12 ISUZU MOTORS LTD
  • EP2846016B1 patent drawingFigure 1~2A
  • EP2846016B1 patent drawingFigure 2B
  • EP2846016B1 patent drawingFigure 3~4

AI summary

The phenomenon of resonance in a catalyst converter due to a flow of an exhaust gas is reduced without causing problems with vehicle layout, problems with manufacturing (higher manufacturing cost), or adverse influences on other facets of performance. An internal combustion engine includes an internal combustion engine main body having a fuel chamber formed in an interior, and a catalyst converter arranged in an exhaust flow channel of the internal combustion engine main body and provided with a catalyst for purifying the exhaust gas. The exhaust flow channel, which is upstream of the catalyst of the catalyst converter, is provided with a protuberance for disturbing the flow of the exhaust gas in the exhaust flow channel to reduce pressure pulsations of the exhaust gas.