Ngk Insulators, Inc.

Tomohiro Iida

Kazuto Miura

Osamu Yasui

Takashi Aoki

Yukio Miyairi

Yukihisa Wada

Jun Okumura

Jiro Maeda

Provided is a honeycomb filter, including: a pillar-shaped honeycomb substrate having an inflow end face and an outflow end face and including a porous partition wall surrounding a plurality of cells; and a plugging portion disposed at any one of ends of the cells at the inflow end face and at the outflow end face. In a cross section orthogonal to an extending direction of the cells, inflow cells have a pentagonal or a hexagonal shape, and outflow cells have a square shape. The cells are configured that the inflow cells surround one outflow cell and one side of an inflow cell and one side of an adjacent outflow cell are parallel to each other. The partition wall is configured that thickness of a first partition wall disposed between the inflow cells and the outflow cells is larger than thickness of a second partition wall disposed between the inflow cells.

Honeycomb filter

Provided is a honeycomb filter, including: a pillar-shaped honeycomb substrate having an inflow end face and an outflow end face and including a porous partition wall surrounding a plurality of cells; and a plugging portion disposed at any one of ends of the cells at the inflow end face and at the outflow end face. In a cross section orthogonal to an extending direction of the cells, inflow cells have a pentagonal or a hexagonal shape, and outflow cells have a square shape. The cells are configured that the inflow cells surround one outflow cell and one side of an inflow cell and one side of an adjacent outflow cell are parallel to each other. The partition wall is configured that thickness of a first partition wall disposed between the inflow cells and the outflow cells is smaller than thickness of a second partition wall disposed between the inflow cells.

A honeycomb structure body is constituted of a circumferential region including the outermost circumference in a cross section of the honeycomb structure body which is perpendicular to an extending direction of cells, and a central region excluding the circumferential region. The circumferential region includes a specific circumferential region in which pressure loss with soot when an amount of the deposited soot is 4 g/L is higher than the pressure loss with soot of the central region as much as 15% or more and in which an open frontal area of the circumferential region is the same as or larger than an open frontal area of the central region. In the cross section of the honeycomb structure body, a ratio of an area of the specific circumferential region is 5% or more to a total area of the circumferential region and the central region.

Plugged honeycomb structure

A plugged honeycomb structure includes a plurality of honeycomb segments, a bonding layer, and plugging portions plugging open ends of cells of the honeycomb segments. The honeycomb segments include circumferential segments and central segments. The circumferential segments include at least one specific circumferential segment in which pressure loss with soot when an amount of the deposited soot is 4 g/L is higher than the pressure loss with soot of the central segment as much as 15% or more and in which an open frontal area of the circumferential segment is the same as or larger than an open frontal area of the central segment. In a cross section of a honeycomb structure body which is perpendicular to an extending direction of the cells, a ratio of an area of the specific circumferential segment is 4% or more to a total area of the circumferential segments and the central segments.

A honeycomb structure includes a porous partition wall defining a plurality of cells, wherein the plurality of cells include a first cell and a second cell, an open frontal area of the first cell on the first end face is larger than that of the second cell on the second end face, on the partition wall disposed to surround the at least one first cell, a protrusion which protrudes into the first cell is provided with, the first protrusion and the second protrusion are each disposed not to overlap with each other on extended lines in extending directions of the respective protrusions, and a protrusion height (H) of the first protrusion and a protrusion height (H) of the second protrusion are each equal to or more than 15% and equal to or less than 90% with respect to a mutual distance W of the partition walls facing each other.

Honeycomb structure

A plugged honeycomb structure including: a pillar-shaped honeycomb structure body having porous partition walls made of a material including silicon carbide, and plugging portions, wherein a porosity of the partition walls is from 42 to 52%, a thickness of the partition walls is from 0.15 to 0.36 mm, a ratio of a volume of pores having pore diameters of 10 &#x3bc;m or less to a total pore volume of the partition walls is 41% or less, a ratio of a volume of pores having pore diameters in a range of 18 to 36 &#x3bc;m to the total pore volume is 10% or less, the pore diameter indicating a maximum value of the log differential pore volume is in a range of 10 to 16 &#x3bc;m, and a half-value width of a peak including the maximum value of the log differential pore volume is 5 &#x3bc;m or less.

There is disclosed a honeycomb structure which is useful as a trapping filter for an exhaust gas, above all a diesel particulate filter (DPF) for trapping particulate matters (particulates) in an exhaust gas from a diesel engine and in which internal and external temperature rises are uniformed during use and during regeneration and in which there are effectively prevented generation of defects such as cracks due to a thermal stress and generation of an adverse influence on a carried catalyst. A honeycomb structureincludes: a bonded honeycomb segment articlein which bond surfaces of a plurality of honeycomb segmentsare integrally bonded to one another via bonding material layers; and an outer peripheral coating layerwhich coats an outer peripheral surface of the bonded honeycomb segment article. The honeycomb structure has a structure in which a plurality of cellsforming fluid channels are arranged in parallel with one another in a central axis direction. The honeycomb segmentsare bonded via the bonding material layers (partial bonding material layers)disposed only in predetermined portions of the honeycomb segments

A soot accumulation amount estimation method for an exhaust gas purification filter according to the present invention includes: a first step of burning soot collected in pores of the exhaust gas purification filter () to regenerate the filter (); a second step of detecting a temperature of exhaust gas flowing into the filter (), to judge whether or not the exhaust gas temperature is equal to or lower than a predetermined temperature at which a soot amount flowing into the filter () is substantially equal to a soot amount to be burnt in the filter (); a third step of adding up a period of time during which the exhaust gas temperature is equal to or lower than the predetermined temperature, when the exhaust gas temperature is equal to or lower than the predetermined temperature, when the a fourth step of judging whether or not the added up period of time is equal to or longer than a period of time during which a predetermined amount of soot is accumulated in the pores after the first step; and a fifth step of estimating a soot accumulation amount of the filter () based on a pressure loss through the filter (), when the added up period of time is equal to or longer than the period of time during which the predetermined amount of soot is accumulated.

Method of estimating soot accumulation amount of exhaust gas purification filter, and computer program product therefor

There is disclosed a die for forming a honeycomb structure and a method of manufacturing the honeycomb structure by use of the die, in which variations of cell pitches are suppressed in a central portion and the vicinity of an outer periphery after drying and firing an extruded honeycomb structure, and the honeycomb structure having a uniform cell pitch can be manufactured. A diefor forming a honeycomb structure has a front surface provided with groovy slitsformed between cell blocksand a back surface provided with back holescommunicating with the slits. The diehas a structure in which a pitch P of the adjacent cell blocksis enlarged from a central portion of the front surface toward an outer periphery in a stepwise manner.

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Nagoya, Japan

Tomohiro Iida