US 7,582,266 B2 · Honeycomb body, exhaust system having the honeycomb body and method for muffling sound in the exhaust system of an internal combustion engine

Abstract

A honeycomb body for an exhaust system of an internal combustion engine has an axial length and channels which are substantially separated from each other and through which an exhaust gas can flow. The honeycomb body includes at least one first and one second subset of channels. At least the cross-sectional areas of one of the subsets of channels differs along the axial length of the honeycomb body, so that a transient time of the exhaust gas in the different subsets of channels is different. The difference in transient time of the exhaust gas between the different subsets of channels can be used for damping sound waves having one or more wavelengths, so that noise is reduced in the exhaust system in order to purify the exhaust gas without needing additional components in the exhaust system. An exhaust system and a method for muffling sound therein are also provided.

Claims33

Dependent claims

A honeycomb body for an exhaust system of an internal combustion engine, the honeycomb body comprising:

an axial length having a first end and second end opposite said first end;
channels through which exhaust gas can flow, said channels being substantially separate from one another, each of said channels extending from said first end to said second end and opening at both of said ends, the exhaust gas flowing through said channels in a main direction of flow;
said channels including at least a first subset of channels and a second subset of channels, and at least one of said subsets of channels having cross-sectional areas changing over said axial length, causing a transient time of the exhaust gas to be different in said first and second subsets of channels, said cross-sectional area of at least one of said subsets of channels decreasing in said main direction of flow.

An exhaust system of an internal combustion engine, the exhaust system comprising:

at least one honeycomb body having channels through which exhaust gas can flow and having an axial length with a first end and second end opposite said first end, each of said channels extending from said first end to said second end and opening at both of said ends, the exhaust gas flowing through said channels in a main direction of flow;
said channels including a first subset of channels and a second subset of channels, said first subset of channels forming a flow path for a first partial quantity of the exhaust gas, and said second subset of channels forming a flow path for a second partial quantity of the exhaust gas;
and at least one of said first and second subsets of channels having cross-sectional areas changing over said axial length of said at least one honeycomb body, causing a transient time of the exhaust gas to be different in said first and second subsets of channels, said cross-sectional area of at least one of said subsets of channels decreasing in said main direction of flow.

A method for muffling sound in an exhaust system of an internal combustion engine, the method which comprises:

providing the exhaust system with at least one honeycomb body having an axial length with a first end and second end opposite said first end and having first and second subsets of channels through which the exhaust gas can flow, each of said channels extending from said first end to said second end and opening at both of said ends;
passing a first partial quantity of the exhaust gas through the first subset of channels and passing a second partial quantity of the exhaust gas through the second subset of channels;
providing at least one of the first and second subsets of channels with cross-sectional areas changing over the axial length of the honeycomb body, resulting in a difference in transient time of the exhaust gas in the first and second subsets of channels;
providing at least one of the subsets of channels with a cross-sectional area decreasing in a main direction of flow;
and combining the partial quantities of the exhaust gas again downstream of the at least one honeycomb body.

2 more elements

Dependencies are inferred from the claim text.

Honeycomb body, exhaust system having the honeycomb body and method for muffling sound in the exhaust system of an internal combustion engine

Life of this patent

Honeycomb body, exhaust system having the honeycomb body and method for muffling sound in the exhaust system of an internal combustion engine

Life of this patent

Abstract

Claims33