Catalytic converter apparatus for purifying exhaust gas

Abstract

The present invention relates to a catalytic converter apparatus for purifying exhaust gas from an internal combustion engine for vehicles. The catalytic converter apparatus includes a first catalytic converter that holds a first catalyst and that is to be coupled to a side of the engine, and a second catalytic converter that holds a second catalyst and that is coupled to a rear of the first catalytic converter. Each of the first and second catalysts has a catalytic support on which a wash coat layer having a thickness equal to or less than 0.2 mm is formed. The wash coat layer includes a first wash coat layer and a second wash coat layer, and each of the first and second wash coat layers has voids therein. This catalytic converter apparatus achieves an improved purification property with a small number of cells and a small amount of noble metal.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

For more complete understanding of the present invention and the advantages hereof, reference is now made to the following description taken in conjunction with the accompanying drawings wherein:

FIG. 1 is a perspective view depicting a catalytic converter apparatus according to an embodiment of the present invention;

FIG. 2 is a cross-section view of a catalyst support and a wash coat layer formed thereon in a honeycomb structure of a catalyst that is supported by a catalytic converter in the catalytic converter apparatus;

FIG. 3 is a perspective view depicting an engine's exhaust system in a test vehicle Y;

FIG. 4 is a perspective view depicting an engine's exhaust system in a test vehicle Z;

FIG. 5 is graphs and a table which all show a comparative result of a purifying properties in a G type exhaust structure;

FIG. 6 is graphs and a table which all show a comparative result of a purifying properties in an H type exhaust structure;

FIG. 7 is a perspective view depicting an engine's exhaust system in a test vehicle X;

FIG. 8A is a perspective view depicting a catalyst supported by a catalytic converter apparatus; and

FIG. 8B is an enlarged cress-section view of an internal structure of the catalyst.

Claims

1. A catalytic converter apparatus for purifying exhaust gas from an internal combustion engine for vehicles, comprising: a first catalytic converter for holding a first catalyst, the first catalytic converter being to be coupled to a side of the internal combustion engine;a second catalytic converter for holding a second catalyst, the second catalytic converter being coupled to a rear of the first catalytic converter;each of the first and second catalysts having a catalytic support on which a wash coat layer having a thickness equal to or less than 0.2 mm is formed;the wash coat layer including a first wash coat layer and a second wash coat layer; andeach of the first and second wash coat layers having a plurality of voids therein.

2. The catalytic converter apparatus according to claim 1, wherein each of voids is 0.004 mm±0.002 mm in diameter.

3. The catalytic converter apparatus according to claim 1, wherein the voids occupy 10% to 60% of a whole volume of each of the first and second wash coat layers.

4. The catalytic converter apparatus according to claim 2, wherein the voids occupy 10% to 60% of a whole volume of each of the first and second wash coat layers.