Exhaust gas purification filter

Patent metadata

Field	Value
Publication number	US-11878263-B2
Application number	US-202117487111-A
Country	US
Kind code	B2
Filing date	Sep 28, 2021
Priority date	Mar 29, 2019
Publication date	Jan 23, 2024
Grant date	Jan 23, 2024

Abstract

An exhaust gas purification filter is configured to he disposed in an exhaust passage in a gasoline engine. The exhaust gas purification filter includes partition walls including a plurality of pores, a plurality of cells partitioned by the partition walls, and sealing portions alternately sealing ends of a plurality of the cells in the exhaust gas purification filter. The partition walls each have an average pore diameter of more than 16 μm and less than 21 μm, and have a ratio of an average surface opening diameter of the pores in a partition wall surface to the average pore diameter of the partition wall of 0.66 or more and 0.94 or less.

First claim

What is claimed is:

1. An exhaust gas purification filter configured to be disposed in an exhaust passage in a gasoline engine, the exhaust gas purification filter comprising:
partition walls each comprising a plurality of pores;
a plurality of cells partitioned by the partition walls; and
sealing portions alternately sealing ends of the plurality of the cells in the exhaust gas purification filter, wherein
the partition walls each:
have an average pore diameter of more than 16 μm and less than 21 μm; and
have a ratio of an average surface opening diameter of the pores in a partition wall surface to the average pore diameter of the partition wall of 0.66 or more and 0.94 or less,

wherein:
a length of the exhaust gas purification filter is longer than 20 mm in a filter axial direction;
wherein the exhaust gas purification filter is configured and adapted so that, with accumulated ash components of 20 g/L to 40 g/L, an amount of the accumulated ash components is greater at a position of 10 mm from a filter end surface on an exhaust gas inflow side than at a central position between the filter end surface on the exhaust gas inflow side and a filter end surface on an exhaust gas outflow side; and
a gas permeability coefficient ratio k c /k 10 has a value in a range of 1.0 to 1.5, where k 10 is a gas permeability coefficient of the partition wall at the position of 10 mm from the filter end surface on the exhaust gas inflow side and k c is the permeability coefficient of the partition wall at the central position between the filter end surface on the exhaust gas inflow side and the filter end surface on the exhaust gas outflow side.

2. The exhaust gas purification filter according to claim 1 , wherein
a presence ratio of a surface opening diameter of 25 μm or more of the pores in the partition wall surface on the exhaust gas inflow side is 10% or more and 20% or less.

3. The exhaust gas purification filter according to claim 1 , wherein
a surface opening ratio of the pores in the partition wall surface on the exhaust gas inflow side is 30% or more and 40% or less.

4. The exhaust gas purification filter according to claim 1 , wherein
a porosity of the partition wall is 60% or more and 70% or less.

5. The exhaust gas purification filter according to claim 1 , wherein
a porosity of the partition wall is 63% or more and 66% or less.

Assignees

• Denso Corp

Inventors

• Mizutani Keisuke
• Koike Kazuhiko
• Ishihara Mikio

Classifications

• B01D46/2429 Primary

  of the honeycomb walls or cells · CPC title

• B01D46/249

  Quadrangular e.g. square or diamond · CPC title

• B01D46/24492

  Pore diameter · CPC title

• F01N3/022

  characterised by specially adapted filtering structure, e.g. honeycomb, mesh or fibrous · CPC title

• B01D2279/30

  for treatment of exhaust gases from IC Engines · CPC title