Muffler With Crossed Intermediate Tubes For Exhaust Noise Reduction

Solution Overview

Problem

In multi-cylinder internal combustion engines, the collision and mixing of exhaust streams from different cylinder banks within the muffler lead to increased backpressure and exhaust noise due to undesired interactions, which existing muffler designs fail to adequately address.

Innovation Solution

The muffler design features first and second tubes with distinct inlet and outlet portions aligned along different axial planes, with intermediate portions that cross and are partially stacked, creating separate flow paths for each exhaust stream, reducing direct collision and mixing, and incorporating a common chamber for limited interaction, thereby reducing noise and backpressure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If exhaust streams from different cylinder banks are allowed to collide and mix within the muffler, then noise damping can occur, but backpressure increases and exhaust noise is amplified

Engineering Contradiction:

Improveexhaust noiseVSAvoidbackpressure

Core Design Contradiction:

Object-affected harmful factorsVSStress or pressure

Solution Approach 1:

The muffler is divided into multiple flow paths (first flow path and second flow path) that are substantially separate from each other. Each flow path handles exhaust streams from different cylinder banks independently, preventing collision and mixing while maintaining noise damping functionality through segmented treatment of exhaust gases.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent uses three-dimensional spatial arrangement with intermediate portions that cross and stack vertically. The first intermediate portion extends between first axial planes while the second intermediate portion extends between second axial planes at different vertical levels, utilizing vertical dimension to separate flow paths and eliminate harmful interactions.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Object-affected harmful factors

If exhaust streams from different cylinder banks are allowed to collide and mix within the muffler, then some noise damping can occur, but exhaust noise within the muffler increases

Engineering Contradiction:

Improveexhaust noiseVSAvoidexhaust noise within muffler

Core Design Contradiction:

Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The muffler is divided into multiple flow paths (first flow path and second flow path) that are substantially separate from each other. Each flow path handles exhaust streams from different cylinder banks independently, preventing collision and mixing while maintaining noise damping functionality through segmented treatment of exhaust gases.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The intermediate portions (first intermediate portion and second intermediate portion) act as mediators that guide exhaust streams through crossing paths without allowing direct interaction. These portions are fluidly coupled to inlet and outlet portions while maintaining separation, enabling noise damping without harmful noise generation.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Stress or pressure

If separate flow paths are created for exhaust streams, then backpressure is reduced, but device complexity increases

Engineering Contradiction:

ImprovebackpressureVSAvoidmuffler structure

Core Design Contradiction:

Stress or pressureVSDevice complexity

Solution Approach 1:

The first and second flow paths are merged into a single muffler housing, sharing common inlet and outlet portions. The intermediate portions cross and stack within the same structure, combining multiple functions (separation, noise damping, flow guidance) into one integrated device rather than using separate components.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent uses three-dimensional spatial arrangement with intermediate portions that cross and stack vertically. The first intermediate portion extends between first axial planes while the second intermediate portion extends between second axial planes at different vertical levels, utilizing vertical dimension to separate flow paths without increasing horizontal footprint or overall complexity.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Data Source

PatentUS11692470B2Exhaust system and muffler

Publication Date: 2023.07.04 TENNECO AUTOMOTIVE OPERATING COMPANY INC

AI summary

A muffler for use with an internal combustion engine is provided. The muffler includes a first tube configured to receive a first exhaust stream. The first tube includes a first inlet portion, a first outlet portion spaced apart from the first inlet portion, and a first intermediate portion extending between the first inlet portion and the first outlet portion. The muffler also includes a second tube configured to receive a second exhaust stream. The second tube includes a second inlet portion, a second outlet portion spaced apart from the second inlet portion, and a second intermediate portion extending between the second inlet portion and the second outlet portion. The first intermediate portion and the second intermediate portion cross each other, are at least partially stacked on each other, and are in fluid communication with each other.