Honeycomb structural body

Patent metadata

Field	Value
Publication number	US-9586195-B2
Application number	US-201314373824-A
Country	US
Kind code	B2
Filing date	Jan 17, 2013
Priority date	Jan 27, 2012
Publication date	Mar 7, 2017
Grant date	Mar 7, 2017

Abstract

A honeycomb structural body is made of cordierite ceramic and composed of partition walls and cells. A cell density is changed continuously or step by step from a central section to an outer peripheral section in a radial direction. The honeycomb structural body has a relationship of M1>M2>M3, and a relationship of K1<K2. M1 is an average cell density of a first section formed from a center to not more than ⅓ R from the center. M2 is an average cell density of a second section formed within a range from ⅓ R to ⅔ R. M3 is an average cell density of a third section formed of more than ⅔ R from the center to an outer peripheral surface. K1 and K2 are average cell density change rates of the first and second sections, respectively. R is a radius of the honeycomb structural body.

First claim

The invention claimed is:

1. A honeycomb structural body made of cordierite ceramic and composed of a plurality of partition walls and cells, each cell being surrounded by the partition walls and arranged in a lattice shape in a cross section perpendicular to an axial direction of the honeycomb structural body,
wherein a cell density of the cells is changed step by step from a central section to an outer peripheral section in a cross section which is perpendicular to an axial direction of the honeycomb structural body,
the honeycomb structural body is divided to a first section, a second section and a third section, which are radially concentric from a center to an outer periphery of the honeycomb structural body,
the first section is formed within a range from the center of the honeycomb structural body to a distance of not more than ⅓ R from the center, the second section is formed within a range from a distance of more than ⅓ R from the center to a distance of not more than ⅔ R from the center, the third section is within a range of more than ⅔ R from the center to an outer peripheral surface of the honeycomb structural body, where R is a radius of the honeycomb structural body,
the honeycomb structural body has a relationship of M1>M2>M3, where M1 is an average cell density of the first section, M2 is an average cell density of the second section, and M3 is an average cell density of the third section, the cell density of the first section does not change, and the cell density of the third section does not change,
the honeycomb structural body further has a relationship of K1<K2, where K1 is an average cell density change rate of the first section, and K2 is an average cell density change rate of the second section, and
the honeycomb structural body has a relationship of K2>K3, where K3 is an average cell density change rate of the third section.

2. The honeycomb structural body according to claim 1 , wherein the honeycomb structural body further has a relationship of 1.1≦D1/D2≦2, where D1 is an average cell density of a central section, D2 is an average cell density of an outer peripheral section, the center section is formed within a range from the center to a distance of not more than ⅕ R from the center, and the outer peripheral section is formed within a range from a distance outward from of ⅘ R from the center to the outer peripheral surface of the honeycomb structural body.

3. The honeycomb structural body according to claim 2 , wherein the honeycomb structural body has a relationship of 1.15≦D1/D2≦1.5.

4. The honeycomb structural body according to claim 1 , wherein the honeycomb structural body is a single molded module having a monolithic form.

5. The honeycomb structural body according to claim 1 , wherein an average cell density of an outermost peripheral section is greater than an average cell density of the third section excepting the outermost peripheral section, where the outermost peripheral section is formed in a radial direction within a range from the outer peripheral surface to a distance of 5% of an outer diameter of the honeycomb structural body from the outer peripheral surface.

Assignees

• Denso Corp
• Toyota Motor Co Ltd

Inventors

• Hayashi Naohiro
• Murata Masakazu
• Kuno Oji
• Suzuki Hiromasa
• Matsubara Hiroyuki

Classifications

• B01J29/70 Primary

  of types characterised by their specific structure not provided for in groups B01J29/08 - B01J29/65 · CPC title

• B01D2046/2481

  Operations & Transport · mapped topic

• C04B2235/775

  Products showing a density-gradient · CPC title

• C04B2235/3206

  Magnesium oxides or oxide-forming salts thereof · CPC title

• C04B38/0009

  characterised by features relating to the cell walls, e.g. wall thickness or distribution of pores in the walls · CPC title