JP2011056463A - Honeycomb structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a honeycomb structure capable of preventing the formation of cracks and embers upon operation (regeneration) for burning collected particulates. <P>SOLUTION: The honeycomb structure 100 includes honeycomb segments 5 each comprising a plurality of separation walls demarcating and forming a plurality of cells that extend from one end surface to the other end surface to serve as flow passages under conditions where side faces are mutually bonded. At the cross-sectional surface that is perpendicular to the direction along which cells extend, the honeycomb segment 5a located in an interior region is formed in a longitudinal direction so that the both ends are formed thick and the segment 5a is tapered toward the central portion and in the segment 5a located in the interior region in the cross section perpendicular to the direction in which the cell extends the width T1 at the central portion and the width T2 at the end portion satisfy the relationship represented by the following formula (1): 1.3≤T2/T1≤4.0. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a honeycomb structure, and more particularly to a honeycomb structure that can prevent generation of cracks in an operation (regeneration) of burning collected particulate matter.

  Ceramic honeycomb structure with excellent heat resistance and corrosion resistance is used as a carrier or filter for catalyst devices used for environmental measures and recovery of specific materials in various fields such as chemistry, electric power, steel, etc. Has been. In particular, recently, a honeycomb structure has a plugged honeycomb structure by alternately plugging the cell openings on both end faces, and particulate matter (PM: particulate matter) discharged from a diesel engine or the like. It is actively used as a diesel particulate filter (DPF) that collects water. As a material for the honeycomb structure used in a high temperature and corrosive gas atmosphere, silicon carbide (SiC), cordierite, aluminum titanate (AT), etc. excellent in heat resistance and chemical stability are suitable. It is used for.

  Since silicon carbide has a relatively high coefficient of thermal expansion, a honeycomb structure formed using silicon carbide as an aggregate may have a defect due to thermal shock during use when a large structure is formed. In addition, defects may occur due to thermal shock when the collected particulate matter is removed by combustion. For this reason, in the case of manufacturing a honeycomb structure formed of silicon carbide as an aggregate, a plurality of small plugged honeycomb structures (honeycomb segments) are usually manufactured and the segments are manufactured. Are joined to each other to produce one large joined body, and the outer periphery thereof is roughly processed and ground to form a honeycomb structure having a desired shape such as a cylindrical shape (see, for example, Patent Document 1).

JP 2007-260530 A

  Such a honeycomb structure formed by bonding the honeycomb segments on the respective side surfaces (bonded honeycomb structure) is used as a DPF, and an operation (regeneration) for burning the collected particulate matter is performed. Used while doing. In the bonded honeycomb structure, when the particulate matter is collected, the particulate matter is easily collected at the central portion of each segment (the central portion in the cross section perpendicular to the cell extending direction). For this reason, the temperature of the central part of the honeycomb segment becomes high during regeneration, and the temperature difference from the outer peripheral part of the honeycomb segment (the outer peripheral part in the cross section perpendicular to the cell extending direction) increases. There was a problem that occurred.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a honeycomb structure capable of preventing the occurrence of cracks in an operation (regeneration) of burning the collected particulate matter. To do.

  In order to solve the above-described problems, the present invention provides the following honeycomb structure.

[1] A plurality of honeycomb segments having partition walls for partitioning a plurality of cells extending from one end face to the other end face to be a fluid flow path in a state in which the side faces are joined to each other, In the cross section perpendicular to the cross section, the honeycomb segment located in the inner region is formed such that both end portions are thick in the longitudinal direction and gradually narrow toward the central portion, and in the cross section perpendicular to the cell extending direction. In the honeycomb segment located in the inner region, a honeycomb structure in which a width T1 at the central portion and a width T2 at the end satisfy the relationship of the following formula (1).
1.3 ≦ T2 / T1 ≦ 4.0 (1)

[2] In the honeycomb segment located in the inner region in the cross section orthogonal to the cell extending direction, each end edge of the both end portions in the longitudinal direction is formed in a convex shape or a straight shape toward the outer side. The honeycomb structure according to [1], wherein the two side edge portions connecting the both end edges are recessed inward.

[3] In the honeycomb segment located in the inner region in the cross section orthogonal to the cell extending direction, the two side edges are linear or curved in the center [2]. The honeycomb structure according to 1.

[4] In a cross section orthogonal to the cell extending direction, the honeycomb segment located in the inner region is line-symmetric with a straight line passing through the central portion in the longitudinal direction and orthogonal to the longitudinal direction as an axis of symmetry. The honeycomb structure according to any one of [1] to [3], which has a shape.

[5] The honeycomb structure according to any one of [1] to [4], wherein a cross-sectional area of the honeycomb segment located in the inner region in a cross section orthogonal to the cell extending direction is 1100 to 1600 mm ² .

[6] The honeycomb structure according to any one of [1] to [5], wherein a material of the honeycomb segment is silicon carbide.

  In the honeycomb structure of the present invention, in the cross section orthogonal to the cell extending direction, the honeycomb segment located in the inner region is formed such that both end portions are formed thick in the longitudinal direction and gradually become thinner toward the central portion. In the honeycomb segment formed in the cross section perpendicular to the cell extending direction and positioned in the inner region, the width T1 at the center portion and the width T2 at the end portion are expressed by the following expression (1): 1.3 ≦ The relationship of “T2 / T1 ≦ 4.0” is satisfied. Therefore, in the cross section orthogonal to the cell extending direction, each of the honeycomb segments located in the inner region is divided into two regions (intra-segment regions) by a straight line passing through the central portion in the longitudinal direction and orthogonal to the longitudinal direction. Sometimes, a large amount of particulate matter is collected at the central position in each “intra-segment region”, and two high-temperature regions are formed in each segment during regeneration. In each segment area, compared to the prior art, apparently, a high-temperature area with the same maximum temperature is formed with a small cross-sectional area. The temperature difference at the outer periphery of the honeycomb segment is reduced. That is, the temperature of the entire honeycomb segment can be made more uniform during regeneration, thereby preventing cracks from occurring on the end face of the honeycomb structure during regeneration, and the temperature of the outer peripheral portion of the honeycomb segment. Is raised to a sufficient height, so that the particulate matter can be prevented from remaining unburned.

1 is a perspective view schematically showing an embodiment of a honeycomb structure of the present invention. 1 is a plan view schematically showing one embodiment of a honeycomb structure of the present invention. 1 is a plan view schematically showing a honeycomb segment constituting one embodiment of a honeycomb structure of the present invention. 1 is a plan view schematically showing one embodiment of a honeycomb structure of the present invention. It is a top view which shows typically other embodiment of the honeycomb structure of this invention. FIG. 6 is a plan view schematically showing a honeycomb segment constituting another embodiment of the honeycomb structure of the present invention. FIG. 6 is a plan view schematically showing still another embodiment of the honeycomb structure of the present invention. FIG. 5 is a plan view schematically showing a honeycomb segment constituting still another embodiment of the honeycomb structure of the present invention. [Fig. 3] Fig. 3 is a perspective view schematically showing a honeycomb formed body produced in the process of manufacturing an embodiment of the honeycomb structure of the present invention. 1 is a perspective view schematically showing a honeycomb segment constituting one embodiment of a honeycomb structure of the present invention. [Fig. 3] Fig. 3 is a plan view schematically showing a joined honeycomb segment assembly formed by joining a plurality of honeycomb segments, which is manufactured in the process of manufacturing an embodiment of the honeycomb structure of the present invention. [Fig. 5] Fig. 5 is a plan view schematically showing a joined honeycomb segment assembly formed by joining a plurality of honeycomb segments, which is manufactured in the process of manufacturing another embodiment of the honeycomb structure of the present invention.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments for carrying out the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiments, and those skilled in the art do not depart from the spirit of the present invention. It should be understood that design changes, improvements, and the like can be made as appropriate based on ordinary knowledge.

(1) Honeycomb structure:
As shown in FIGS. 1 to 3, an embodiment of the honeycomb structure of the present invention includes a partition wall 1 that partitions and forms a plurality of cells 2 extending from one end face 3 to the other end face 4 serving as a fluid flow path. In the cross section perpendicular to the direction in which the cells 2 extend, the honeycomb segment 5a located in the inner region has two end portions 10 in the longitudinal direction L. , 10 are formed to be thicker and gradually narrower toward the central portion 11, and in the honeycomb segment 5a located in the inner region in the cross section orthogonal to the extending direction of the cell 2, the width T1 in the central portion 11 And the width T2 at the end portion 10 satisfy the relationship of “Expression (1): 1.3 ≦ T2 / T1 ≦ 4.0”. Here, “the honeycomb segment 5a located in the inner region in the cross section orthogonal to the extending direction of the cell 2” is a honeycomb segment that does not constitute the outermost periphery of the honeycomb structure, and all the side surfaces are other honeycombs. It is a honeycomb segment that is in contact with the segment (in contact with a bonding material). In the honeycomb structure 100 of the present embodiment, the outer peripheral portion 8 is disposed on the outermost periphery. FIG. 1 is a perspective view schematically showing one embodiment of a honeycomb structure of the present invention. FIG. 2 is a plan view schematically showing one embodiment of the honeycomb structure of the present invention. FIG. 3 is a plan view schematically showing a honeycomb segment constituting one embodiment of the honeycomb structure of the present invention. In FIG. 2, partition walls and plugging portions constituting each honeycomb segment are omitted. Further, in FIG. 3, the plugging portion is omitted.

  As described above, in the honeycomb structure 100 of the present embodiment, the honeycomb segment 5a located in the inner region in the cross section orthogonal to the extending direction of the cells 2 is formed such that both end portions 10 are thick in the longitudinal direction L. In addition, in the honeycomb segment 5a which is formed so as to become gradually thinner toward the central portion 11 and is located in the inner region in the cross section orthogonal to the extending direction of the cell 2, the width T1 in the central portion 11 and the end portion 10 satisfies the relationship of “formula (1): 1.3 ≦ T2 / T1 ≦ 4.0”. Therefore, in the cross section orthogonal to the extending direction of the cells 2, each of the honeycomb segments 5a located in the inner region is divided into two regions (inside the segment by a straight line passing through the central portion 11 in the longitudinal direction L and orthogonal to the longitudinal direction L. When divided into (regions), a large amount of particulate matter is collected at the central position in each “intra-segment region”, and two high-temperature regions 12 (see FIG. 4) are formed in each segment during regeneration. . In each segment region, a high temperature region having the same maximum temperature is formed with a small cross-sectional area apparently compared with the prior art. Therefore, the temperature increase rate at the outer peripheral portion of the honeycomb segment 5a is improved and the high temperature region at the time of regeneration is increased. 12 and the temperature difference between the outer periphery of the honeycomb segment 5a is reduced. That is, the temperature of the entire honeycomb segment 5a can be made more uniform during regeneration, whereby cracks can be prevented from occurring on the end face of the honeycomb structure 100 during regeneration, and the outer periphery of the honeycomb segment 5a can be prevented. Since the temperature of the part rises to a sufficiently high level, it is possible to prevent the particulate matter from remaining unburned. FIG. 4 is a plan view schematically showing one embodiment of the honeycomb structure of the present invention. In FIG. 4, partition walls and plugging portions constituting each honeycomb segment are omitted.

  In the honeycomb structure 100 of the present embodiment, the honeycomb segment 5a located in the inner region in the cross section orthogonal to the extending direction of the cells 2 has both end portions 10 and 10 formed thick in the longitudinal direction L and the central portion. 11 is formed so as to become thinner gradually, and the central portion 11 is formed to be the thinnest. In the honeycomb structure of the present embodiment, in the honeycomb segment 5a located in the inner region in the cross section orthogonal to the extending direction of the cells 2, the width T1 in the central portion 11 and the width T2 in the end portion 10 are It satisfies the relationship of “Expression (1): 1.3 ≦ T2 / T1 ≦ 4.0”, and satisfies the relationship of “Expression (1): 2.0 ≦ T2 / T1 ≦ 3.0”. Preferably there is. When “T2 / T1” is smaller than 1.3, the shape is similar to that of the conventional product, so that the high temperature region 12 is formed only at one central portion of the honeycomb segment 5a during regeneration. It is not preferable because cracks cannot be prevented. When “T2 / T1” is larger than 4.0, the central portion 11 works as a “notch” (the central portion 11 has a shape that is largely cut away), and stress concentration occurs during reproduction. Since it becomes easy to generate | occur | produce a crack starting from the center part 11, it is not preferable. Further, in the cross section orthogonal to the extending direction of the cells 2, the length T3 in the longitudinal direction L of the honeycomb segment 5a located in the inner region is preferably 30 to 80 mm, and more preferably 35 to 75 mm. . If it is shorter than 30 mm, the pressure loss when treating the exhaust gas may increase. If it is longer than 80 mm, the effect of preventing damage during reproduction may be reduced.

  Here, the “center portion 11” means a set of center points in the longitudinal direction in the honeycomb segment 5a located in the inner region in the cross section orthogonal to the extending direction of the cells 2, and the center point in the longitudinal direction is It can also be called a center line orthogonal to the longitudinal direction. The “width T1 in the central portion 11” means the length in the direction perpendicular to the longitudinal direction L in the central portion 11 in the honeycomb segment 5a located in the inner region in the cross section perpendicular to the extending direction of the cells 2. means. “Width T2 at end portion 10” means the longest portion of end portion 10 in the direction orthogonal to longitudinal direction L in honeycomb segment 5a located in the inner region in the cross section orthogonal to the extending direction of cells 2 ( It means the length of the widest part). In the honeycomb structure 100 of the present embodiment, the most distal portion in the longitudinal direction L is the widest portion in the honeycomb segment 5a located in the inner region in the cross section orthogonal to the cell 2 extending direction. It is not limited to this. For example, as in another embodiment of the honeycomb structure of the present invention shown in FIGS. 5 and 6, in the honeycomb segment 5 a located in the inner region in the cross section orthogonal to the extending direction of the cells 2, in the longitudinal direction L When the end edges 10a and 10a of the both end portions 10 and 10 are convex outward, the most distal portion in the longitudinal direction L is not the widest portion and is slightly closer to the center portion 11 side than the most distal portion. The position close to is the widest part. The width of this portion is “width T2 at the end portion 10”. Note that “the end portion 10 in the longitudinal direction L of the honeycomb segment 5a located in the inner region in the cross section orthogonal to the cell 2 extending direction” is the longitudinal length from the most distal portion of the honeycomb segment 5a in the cross section. 20% of the thickness. The “widest region” may be in the range of the end 10, and the position in the end 10 is not limited.

The honeycomb structure 100 of the present embodiment, in a cross section perpendicular to the extending direction of the cells 2, the area of the honeycomb segment 5a which is located inside the region is preferably 1100～1600Mm ^2, is 1200～1500Mm ² More preferably. If it is smaller than 1100 mm ² , the pressure loss when treating the exhaust gas may increase. When it is larger than 1600 mm ² , the damage prevention effect may be lowered.

  In the honeycomb structure 100 of the present embodiment, in a cross section orthogonal to the extending direction of the cells 2, the honeycomb segment 5a located in the inner region passes through a central portion in the longitudinal direction L and a straight line orthogonal to the longitudinal direction L is an axis of symmetry. A line-symmetric shape is preferable. Thereby, a some honeycomb segment can be arrange | positioned so that each side surface may become parallel, and can be joined. Further, in the honeycomb structure 100 of the present embodiment, the honeycomb segment 5a located in the inner region has a line-symmetric shape having an axis of symmetry parallel to the longitudinal direction L in a cross section orthogonal to the extending direction of the cells 2. It is preferable. The honeycomb structure 100 of the present embodiment more preferably has both a symmetry axis perpendicular to the longitudinal direction L and a symmetry axis parallel to the longitudinal direction L. This makes it easier to arrange and join the plurality of honeycomb segments so that the side surfaces are parallel to each other.

  In the honeycomb structure 100 of the present embodiment, in the honeycomb segment 5a located in the inner region in the cross section orthogonal to the extending direction of the cells 2, the end edges 10a and 10a of the both end portions 10 and 10 in the longitudinal direction L are It is formed in a straight line shape so that the two side edge portions 13, 13 connecting the respective end edges (both end edges) 10a, 10a are recessed inward. Thus, when the honeycomb segments 5a are joined, as shown in FIGS. 1 and 2, the honeycomb segments 5a are opposed to each other in the longitudinal direction L with the edges 10a facing each other in a cross section perpendicular to the extending direction of the cells 2. It can join so that it may extend.

  Further, as shown in FIGS. 5 and 6, in the honeycomb segment 205 a located in the inner region in the cross section orthogonal to the cell extending direction, the respective edges 10 a and 10 a of the both end portions 10 and 10 in the longitudinal direction L. It is also a preferable aspect that the shape of is convex outward. In the honeycomb structure 200 shown in FIG. 5, the edge 10a of the honeycomb segment 205a has a linear shape bent at the center. FIG. 5 is a plan view schematically showing another embodiment of the honeycomb structure of the present invention. Fig. 6 is a plan view schematically showing a honeycomb segment constituting another embodiment of the honeycomb structure of the present invention. In FIG. 5 and FIG. 6, partition walls and plugging portions constituting each honeycomb segment are omitted.

  Further, as shown in FIGS. 7 and 8, still another embodiment (honeycomb structure 300) of the honeycomb structure of the present invention is a honeycomb segment located in an inner region in a cross section orthogonal to the cell extending direction. In 305a, the shape of each edge 10a, 10a of the both ends 10, 10 in the longitudinal direction L is convex toward the outside and is curved. Thus, the shape of the edge 10a may be an outwardly convex curve. FIG. 7 is a plan view schematically showing still another embodiment of the honeycomb structure of the present invention. FIG. 8 is a plan view schematically showing a honeycomb segment constituting still another embodiment of the honeycomb structure of the present invention. In FIGS. 7 and 8, the partition walls and plugging portions constituting each honeycomb segment are omitted.

  As shown in FIGS. 1 and 2, the honeycomb structure 100 of the present embodiment has two side edge portions 13 and 13 in the honeycomb segment 5 a located in the inner region in the cross section orthogonal to the cell extending direction. However, it is a straight line bent at the center. Therefore, in the honeycomb structure 100 of the present embodiment, in the honeycomb segment 5a located in the inner region in the cross section orthogonal to the cell extending direction, the edge 10a is linear and the side edge 13 is bent at the center. It is straight. Further, the honeycomb structure 100 of the present embodiment has a symmetry axis that is perpendicular to the longitudinal direction L and a symmetry that is parallel to the longitudinal direction L in the honeycomb segment 5a located in the inner region in a cross section perpendicular to the cell extending direction. It has both axes. Thereby, in the honeycomb structure 100 of the present embodiment, in the cross section orthogonal to the cell extending direction, the edge of one honeycomb segment is joined to the edge of another honeycomb segment, and the side of one honeycomb segment The edges are formed so as to be joined to the side edges of other honeycomb segments. In the honeycomb segment in which the side edges are joined, the central portion of one honeycomb segment is in contact with the “widest portion at the end” of the other honeycomb segment. Thereby, each honeycomb segment in the honeycomb structure 100 is joined without forming a gap between the honeycomb segments. Note that the gap between the honeycomb segments means a gap formed by a mismatch in the shape of the joint surfaces of adjacent honeycomb segments. For example, in the case where the planar joining surfaces (side surfaces) are joined so as to be parallel to each other, no gap is formed, but the planar joining surface (side surface) and the curved joining surface (side surface) When joining the two, a gap is formed.

  Further, another embodiment (honeycomb structure 200) of the honeycomb structure of the present invention, as shown in FIGS. 5 and 6, is a honeycomb segment 205a located in an inner region in a cross section orthogonal to the cell extending direction. The two side edge portions 13 and 13 are linearly bent at the center. The honeycomb structure 200 of the present embodiment is a straight line bent at the center so that the end edge 10a is convex outward in the honeycomb segment 205a located in the inner region in the cross section orthogonal to the cell extending direction. The side edge 13 is a straight line bent at the center so as to be recessed inward. Further, the honeycomb segment 205a in the honeycomb structure 200 of the present embodiment has both a symmetry axis perpendicular to the longitudinal direction L and a symmetry axis parallel to the longitudinal direction L in a cross section perpendicular to the cell extending direction. is there. Furthermore, the honeycomb segment 205a in the honeycomb structure 200 of the present embodiment has a shape in which the edge 10a and the side edge 13 are complementary in a cross section perpendicular to the cell extending direction, and one honeycomb segment 205a. It is possible to join the end edge 10a of this and the side edge part 13 of the other honeycomb segment 205a without gap. Thereby, in the honeycomb structure 200 of the present embodiment, in the cross section orthogonal to the cell extending direction, the edge of one honeycomb segment abuts on the side edge of the adjacent honeycomb segment, and the one honeycomb Each honeycomb segment is arranged so that the side edge portion of the segment contacts the edge of the adjacent honeycomb segment. Thereby, each honeycomb segment in the honeycomb structure 200 is joined without forming a gap between the honeycomb segments.

  Moreover, as shown in FIGS. 7 and 8, the honeycomb structure of the present invention (honeycomb structure 300) has a honeycomb segment located in an inner region in a cross section orthogonal to the cell extending direction. In 305a, the two side edge portions 13, 13 have a curved shape recessed inward. In the honeycomb structure 300 of the present embodiment, the honeycomb segment 305a located in the inner region in the cross section orthogonal to the cell extending direction has a curved shape in which the edge 10a is convex outward, and the side edge 13 is It is a curved shape that is recessed inward. The edge 10a has a shape with the most protruding center, and the side edge 13 has a shape with the most recessed center. Further, the honeycomb segment 305a in the honeycomb structure 300 of the present embodiment has both a symmetry axis perpendicular to the longitudinal direction L and a symmetry axis parallel to the longitudinal direction L in a cross section perpendicular to the cell extending direction. is there. Furthermore, the honeycomb segment 305a in the honeycomb structure 300 of the present embodiment has a shape in which the edge 10a and the side edge 13 are complementary in a cross section perpendicular to the cell extending direction, and one honeycomb segment 305a. It is possible to join the end edge 10a of this and the side edge part 13 of the other honeycomb segment 305a without gap. Thereby, in the honeycomb structure 300 of the present embodiment, in the cross section orthogonal to the cell extending direction, the edge of one honeycomb segment abuts on the side edge of the adjacent honeycomb segment, and the one honeycomb Each honeycomb segment is arranged so that the side edge portion of the segment contacts the edge of another adjacent honeycomb segment. Thereby, each honeycomb segment in the honeycomb structure 300 is joined without forming a gap between the honeycomb segments. Thereby, each honeycomb segment in the honeycomb structure 300 is joined without forming a gap between the honeycomb segments.

  Among the honeycomb segments constituting one embodiment (honeycomb structure 100) of the honeycomb structure of the present invention shown in FIG. 1, the honeycomb segment located in the inner region in the cross section orthogonal to the cell extending direction The honeycomb segments excluding 5a are honeycomb segments constituting the outermost periphery. The honeycomb segment constituting the outermost periphery has a shape that matches the shape of the outermost periphery of the honeycomb structure, but the surface in contact with the honeycomb segment 5a located in the inner region is the honeycomb segment located in the inner region. It is preferable to be joined to the side surface (contact surface) of 5a without forming a gap. In the honeycomb structure 100 of the present embodiment, the honeycomb segment constituting the outermost periphery is bonded to the periphery of the honeycomb segment 5a located in the inner region, and the honeycomb segment having the same shape as the honeycomb segment 5a is joined. Partly ground and formed in accordance with the outer peripheral shape (cylindrical shape).

  As a material of the honeycomb segment constituting one embodiment of the honeycomb structure of the present invention (honeycomb structure 100), ceramic is preferable, and since it is excellent in strength and heat resistance, silicon carbide, silicon-silicon carbide based composite material More preferably, at least one selected from the group consisting of cordierite, mullite, alumina, spinel, silicon carbide cordierite composite material, lithium aluminum silicate, aluminum titanate, and iron-chromium-aluminum alloy. . Among these, silicon carbide is particularly preferable. Since silicon carbide has a relatively high coefficient of thermal expansion, a honeycomb structure formed using silicon carbide as an aggregate may cause defects due to thermal shock when used, but the honeycomb structure of the present invention The structure is a structure in which a plurality of honeycomb segments are arranged adjacent to each other so that the side surfaces thereof are opposed to each other, and the opposing side surfaces are bonded together by a bonded portion, so that stress due to thermal expansion of silicon carbide is bonded. It is relieved by the part, and the occurrence of defects in the honeycomb structure can be prevented. Further, the outer peripheral portion 8 constituting the outermost periphery of the honeycomb structure of the present embodiment is a mixture of inorganic fibers, colloidal silica, clay, SiC particles, organic binder, foamed resin, dispersant, water, etc. on the outer periphery. It is preferably formed by coating.

  The honeycomb segment constituting the honeycomb structure of the present embodiment (partition walls constituting the honeycomb segment) is preferably porous. The porosity of the honeycomb segment is 30 to 70%, preferably 40 to 60%. By setting the porosity in such a range, the pressure loss can be reduced while maintaining the strength. If the porosity is less than 30%, the pressure loss may increase. When the porosity exceeds 70%, the strength may decrease or the thermal conductivity may decrease. The porosity is a value measured with a mercury porosimeter.

  The honeycomb segment constituting the honeycomb structure of the present embodiment preferably has an average pore diameter of 5 to 30 μm, and more preferably 10 to 25 μm. By setting the average pore diameter in such a range, particulate matter (PM) can be effectively collected. When the average pore diameter is less than 5 μm, the honeycomb structure may be easily clogged with particulate matter (PM). When the average pore diameter exceeds 30 μm, particulate matter (PM) may pass through the honeycomb structure without being collected. The average pore diameter is a value measured with a mercury porosimeter.

  When the material of the honeycomb segment constituting the honeycomb structure of the present embodiment is silicon carbide, the average particle diameter of the silicon carbide particles is preferably 5 to 40 μm. By setting such an average particle diameter, there is an advantage that a honeycomb segment (honeycomb structure) having a porosity and a pore diameter suitable for a filter can be easily formed. When the average particle size is smaller than 5 μm, the pore size becomes too small, and when larger than 40 μm, the porosity becomes too large. If the pore diameter is too small, clogging may be easily caused by the particulate matter (PM), and if the porosity is too large, the strength may decrease. The average particle diameter of the raw material is a value measured according to JIS R 1629.

  The cell shape of the honeycomb segment constituting the honeycomb structure of the present embodiment (cell shape in a cross section orthogonal to the central axis direction of the honeycomb structure (cell extending direction)) is not particularly limited. , Hexagons, octagons, circles, or combinations thereof.

  The partition wall thickness of the honeycomb segment constituting the honeycomb structure of the present embodiment is preferably 2.0 to 4.5 mm, and more preferably 2.5 to 4.0 mm. If it is thinner than 2.0 mm, the strength of the honeycomb structure may be lowered. If it is thicker than 4.5 mm, the pressure loss when gas flows through the honeycomb structure may increase. Moreover, it is preferable that the thickness of the outer peripheral part 8 which comprises the outermost periphery of the honeycomb structure of this embodiment is 0.1-3.0 mm. If it is thinner than 0.1 mm, the strength of the honeycomb structure may be lowered. If it is thicker than 3.0 mm, the collection area for collecting the particulate matter may be small.

Further, the cell density of the honeycomb segment constituting the honeycomb structure of the present embodiment is not particularly limited, but is preferably 20 to 90 cells / cm ² , and more preferably 30 to 70 cells / cm ^2. . If it is less than 20 cells / cm ² , the pressure loss when gas flows through the honeycomb structure may increase. When it is larger than 90 cells / cm ² , the collection area for collecting the particulate matter may be small.

  Further, in the cross section perpendicular to the central axis direction of the honeycomb structure of the present embodiment, the number of honeycomb segments arranged is preferably 4 to 60, and more preferably 9 to 40. The number of honeycomb segments located in the inner region in the cross section perpendicular to the cell extending direction is preferably 1 to 40, and more preferably 4 to 25.

  In the honeycomb structure of the present embodiment, as shown in FIG. 1, plugged portions are formed at one end of a predetermined cell and the other end of the remaining cells of the honeycomb segment 5, Predetermined cells and the remaining cells are alternately arranged. Thereby, as for the honeycomb structure 100 of this Embodiment, the checkered pattern is formed in the both end surfaces by the plugging part and the opening part of a cell. Note that the plugging portion formation pattern (arrangement pattern of the predetermined cells and the remaining cells) is not limited to a pattern in which a checkered pattern is formed on both end faces of the honeycomb structure 100 as described above. Other patterns may be used. The material of the plugging portion is preferably the same as the material forming the honeycomb segment.

  The honeycomb structure of the present embodiment is preferably formed by bonding a plurality of honeycomb segments with a bonding material (a bonding material is disposed between adjacent honeycomb segments). The bonding material functions to bond the honeycomb segments, and also functions as a buffer material when the honeycomb segments undergo deformation such as thermal expansion and contraction, or when a force is applied from the outside. The thickness of the bonding material is preferably 0.1 to 3.0 mm. If it is thinner than 0.1 mm, the bonding strength may be lowered, and the function as a buffer material may be lowered. If it is thicker than 3.0 mm, the pressure loss when flowing exhaust gas through the honeycomb structure may decrease. Examples of the material of the bonding material include colloidal silica.

  The overall shape of the honeycomb structure of the present embodiment is not particularly limited, and can be a desired shape such as a cylindrical shape or an oval shape. Moreover, as for the magnitude | size of a honeycomb structure, it is preferable that the diameter of a bottom face is 80-300 mm in the case of a cylindrical shape, for example, and it is still more preferable that it is 100-280 mm. The length of the honeycomb structure in the central axis direction is preferably 100 to 350 mm, and more preferably 100 to 300 mm.

(2) Manufacturing method of honeycomb structure:
Next, the manufacturing method of one embodiment of the honeycomb structure of the present invention will be described.

(2-1) Preparation of honeycomb segment:
First, a forming raw material is prepared by adding a binder, a surfactant, a pore former, water, and the like to the ceramic raw material. Ceramic raw materials include silicon carbide, silicon-silicon carbide composite material, cordierite, mullite, alumina, spinel, silicon carbide-cordierite composite material, lithium aluminum silicate, aluminum titanate, iron-chromium-aluminum alloy It is preferably at least one selected from the group consisting of Among these, silicon carbide is preferable. The content of the ceramic raw material is preferably 40 to 90% by mass with respect to the entire forming raw material.

  Examples of the binder include methyl cellulose, hydroxypropoxyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, and polyvinyl alcohol. Among these, it is preferable to use methyl cellulose and hydroxypropoxyl cellulose in combination. The binder content is preferably 3 to 15% by mass with respect to the entire forming raw material.

  The water content is preferably 7 to 45 mass% with respect to the entire forming raw material.

  As the surfactant, ethylene glycol, dextrin, fatty acid soap, polyalcohol and the like can be used. These may be used individually by 1 type and may be used in combination of 2 or more type. The content of the surfactant is preferably 5% by mass or less with respect to the entire forming raw material.

  The pore former is not particularly limited as long as it becomes pores after firing, and examples thereof include starch, foamed resin, water absorbent resin, silica gel and the like. The pore former content is preferably 15% by mass or less based on the entire forming raw material.

  Next, a kneaded material is kneaded to form a clay. There is no restriction | limiting in particular as a method of kneading | mixing a shaping | molding raw material and forming a clay, For example, the method of using a kneader, a vacuum clay kneader, etc. can be mentioned.

  Next, the kneaded material is extruded to form 14 honeycomb molded bodies 21 as shown in FIG. The number of honeycomb formed bodies to be manufactured can be appropriately determined according to the size of the honeycomb structure to be manufactured. The honeycomb formed bodies 21 can all have the same shape, and there is no need to form a plurality of types of honeycomb formed bodies. When the honeycomb structure is manufactured, it is necessary that at least one honeycomb segment does not form the outermost periphery. In extrusion molding, it is preferable to use a die having a desired segment shape, segment arrangement, cell shape, partition wall thickness, cell density, and the like. As the material of the die, a cemented carbide which does not easily wear is preferable. The honeycomb formed body 21 has a structure having a porous partition wall 1 for partitioning and forming a plurality of cells 2 serving as fluid flow paths and an outer peripheral wall 7 located at the outermost periphery. The shape of the cross section orthogonal to the cell extending direction of the honeycomb formed body 21 is the shape of the honeycomb segment located in the inner region in the cross section orthogonal to the cell extending direction of one embodiment of the honeycomb structure of the present invention. The shape is preferably the same. FIG. 9 is a perspective view schematically showing a honeycomb formed body 21 produced in the process of manufacturing an embodiment of the honeycomb structure of the present invention.

  The partition wall thickness, cell density, outer peripheral wall thickness and the like of the honeycomb formed body 21 can be appropriately determined in accordance with the structure of the honeycomb structure of the present invention to be manufactured in consideration of shrinkage during drying and firing. .

  The obtained honeycomb formed body 21 is preferably dried before firing. The drying method is not particularly limited, and examples thereof include an electromagnetic heating method such as microwave heating drying and high-frequency dielectric heating drying, and an external heating method such as hot air drying and superheated steam drying. Among these, the entire molded body can be dried quickly and uniformly without cracks, and after drying a certain amount of moisture with an electromagnetic heating method, the remaining moisture is dried with an external heating method. It is preferable to make it. As drying conditions, it is preferable to remove moisture of 30 to 90% by mass with respect to the amount of moisture before drying by an electromagnetic heating method, and then to make the moisture to 3% by mass or less by an external heating method. As the electromagnetic heating method, dielectric heating drying is preferable, and as the external heating method, hot air drying is preferable.

  Next, when the length in the central axis direction of the honeycomb formed body 21 is not a desired length, it is preferable to cut both ends to obtain a desired length. The cutting method is not particularly limited, and examples thereof include a method using a circular saw cutting machine.

  Next, the honeycomb formed body 21 is preferably fired to produce a honeycomb fired body. In order to remove the binder or the like before firing, it is preferable to perform temporary firing. Pre-baking is preferably performed at 400 to 500 ° C. for 0.5 to 20 hours in an air atmosphere. The method of temporary baking and baking is not particularly limited, and baking can be performed using an electric furnace, a gas furnace, or the like. Firing conditions are preferably heated at 1300 to 1500 ° C. for 1 to 20 hours in an inert atmosphere such as nitrogen or argon.

  Next, in the obtained honeycomb fired body, plugged portions are formed at one end portion of a predetermined cell and the other end portion of the remaining cells, and the honeycomb segment 22 shown in FIG. 10 is manufactured. A method for forming the plugged portion is not particularly limited, and examples thereof include the following methods. After the sheet is attached to one end face of the honeycomb fired body, a hole is opened at a position corresponding to a cell (predetermined cell) where a plugging portion of the sheet is to be formed. In addition, a plugging slurry obtained by slurrying the constituent material of the plugging portion is stored in a container. Then, the end of the honeycomb fired body on which the sheet is pasted is press-fitted into a container in which the plugging slurry is stored, and a cell in which a plugging portion is to be formed through a hole formed in the sheet ( The plugging slurry is filled in the opening of the predetermined cell). For the other end face of the honeycomb fired body, the cells that were not plugged on one end face (remaining cells) were plugged in the same manner as the method in which the plugged portions were formed on the one end face. A sealing portion is formed (filled with a plugging slurry). As the constituent material of the plugged portion, the same material as that of the honeycomb formed body is preferably used. After forming the plugged portion, it is preferable to perform baking under the same conditions as the above baking conditions. The plugging portion may be formed before firing the honeycomb formed body. FIG. 10 is a perspective view schematically showing a honeycomb segment 22 constituting one embodiment of the honeycomb structure of the present invention.

(2-2) Production of honeycomb structure:
Next, the manufactured honeycomb segments are joined with a joining material, and as shown in FIG. 11, 14 honeycomb segments 22 are arranged adjacent to each other so that the side faces face each other, and the side faces facing each other. A honeycomb segment bonded body 23 in which the members are bonded together by a bonding material is produced. The number of honeycomb formed bodies to be joined is preferably a number according to the size of the honeycomb structure to be manufactured. It is preferable that the bonding material is disposed on the entire opposing side surface, that is, the entire bonding surface. The bonding material plays a role of buffering (absorbing) the volume change when the honeycomb segments are thermally expanded and contracted, and also functions of bonding the honeycomb segments. FIG. 11 is a plan view schematically showing a joined honeycomb segment assembly formed by joining a plurality of honeycomb segments, which is manufactured in the process of manufacturing an embodiment of the honeycomb structure of the present invention. In FIG. 11, partition walls and plugging portions constituting each honeycomb segment are omitted.

  When joining the honeycomb segments 22, the edge of one honeycomb segment 22 is joined to the edge of one honeycomb segment 22 in the cross section orthogonal to the cell extending direction, and the side edge of the one honeycomb segment 22 is joined. It is preferable to join the side edges of other honeycomb segments. In the honeycomb segment in which the side edge portions are joined to each other, in the cross section orthogonal to the cell extending direction, the central portion in the longitudinal direction of one honeycomb segment and the “most end portion in the longitudinal direction” of the other honeycomb segment. It is preferable that the “wide portion” is in contact. Thereby, the honeycomb segments in the honeycomb structure 100 can be joined without forming a gap between the honeycomb segments.

  Examples of the bonding material include a slurry obtained by adding water to an inorganic raw material such as inorganic fiber, colloidal silica, clay, and SiC particles and adding an additive such as an organic binder, a foamed resin, and a dispersant, and kneading. it can.

  In the case of manufacturing another embodiment (honeycomb structure 200) (see FIG. 5) of the honeycomb structure of the present invention, when the honeycomb segment bonded body 33 is manufactured by bonding the honeycomb segments 22, As shown in FIG. 12, in the cross section orthogonal to the cell extending direction, the edge of one honeycomb segment 32 abuts on the side edge of the adjacent honeycomb segment 32, and the side edge of the one honeycomb segment. However, it is preferable to arrange each honeycomb segment so as to contact the edge of the adjacent honeycomb segment. The honeycomb segment 32 is formed so that the end edge and the side edge portion have a complementary shape in a cross section orthogonal to the cell extending direction. Fig. 12 is a plan view schematically showing a joined honeycomb segment assembly 33 formed by joining a plurality of honeycomb segments 32, which is manufactured in the process of manufacturing another embodiment of the honeycomb structure of the present invention. . In FIG. 12, partition walls and plugging portions constituting each honeycomb segment are omitted.

  Next, it is preferable that the outer peripheral portion of the honeycomb segment bonded body 23 is cut along the cutting line 24 to obtain the cut honeycomb segment bonded body. For example, when the honeycomb structure 100 shown in FIG. 1 is manufactured, 14 honeycomb segments 22 are joined to produce a honeycomb segment joined body 23, and the outer periphery of the honeycomb segment joined body is cut along the cutting line 24. Thus, a cylindrical “joined honeycomb segment assembly that has been cut” is used. When manufacturing another embodiment of the honeycomb structure of the present invention (honeycomb structure 200) (see FIG. 5), the outer peripheral portion of the joined honeycomb segment assembly 33 shown in FIG. It is preferable to obtain a joined honeycomb segment assembly that has been cut along and cut.

  Next, it is preferable to obtain the honeycomb structure 100 by disposing the outer peripheral portion 8 on the outermost periphery (side surface) of the “cut honeycomb segment bonded body” by performing an outer periphery coating treatment. Examples of the outer periphery coating treatment include a method in which an outer periphery coating material is applied to the outermost periphery of the joined honeycomb segment assembly and dried. As the outer periphery coating material, a mixture of inorganic fiber, colloidal silica, clay, SiC particles, organic binder, foamed resin, dispersant, water, or the like can be used. The content of each raw material is preferably in the same range as the preferable range of the content of the raw material of the bonding material. Moreover, the method of applying the outer periphery coating material is not particularly limited, and examples thereof include a method of coating a bonded honeycomb segment assembly that has been cut with a rubber spatula while rotating it on a potter's wheel.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

Example 1
As ceramic raw materials, SiC powder and metal Si powder are mixed at a mass ratio of 80:20. To this, methylcellulose and hydroxypropoxymethylcellulose are formed as molding aids, starch and water-absorbing resin, surfactant and water are used as pore formers. The kneaded material was added and kneaded, and a square columnar kneaded material was produced with a vacuum kneader.

  The obtained square columnar clay is extruded using a molding machine and a porous partition wall 1 for partitioning a plurality of cells 2 as fluid flow paths and an outer peripheral wall located at the outermost periphery as shown in FIG. 7, each end edge in the longitudinal direction is formed in a straight line in a cross section perpendicular to the extending direction of the cell, and two side edges connecting the respective end edges are inward. And a honeycomb formed body (segment shape: A shape) formed in a linear shape bent at the center. The obtained honeycomb formed body was dried by high-frequency dielectric heating and then dried at 120 ° C. for 2 hours using a hot air dryer, and both end surfaces were cut by a predetermined amount.

  The obtained honeycomb formed body was further dried at 120 ° C. for 5 hours using a hot air dryer, and then degreased for 5 hours at about 450 ° C. using an air furnace equipped with a deodorizing device in an air atmosphere, and then Then, firing was performed at about 1450 ° C. for 5 hours in an Ar inert atmosphere to obtain a porous honeycomb fired body in which SiC crystal particles were bonded with Si. The honeycomb fired body had an average pore diameter of 20 μm and a porosity of 50%. The average pore diameter and porosity are values measured with a mercury porosimeter.

About the obtained honeycomb fired body, plugging portions were formed at one end of a predetermined cell and the other end of the remaining cell so as to form a checkered pattern on both end faces of the honeycomb fired body. . As the plugging filler, the same material as that of the honeycomb formed body was used. After plugging portions were formed on the honeycomb fired body, the honeycomb fired body was fired under the same conditions as the above firing conditions, and honeycomb segments 22 as shown in FIG. 10 were formed. Fourteen honeycomb segments were produced. In the obtained honeycomb segment, the width T1 of the central portion in the longitudinal direction of the cross section perpendicular to the cell extending direction is 17.5 mm, the width T2 of the end portion in the longitudinal direction is 35.0 mm, and the length T3 in the longitudinal direction is 46. 0.7 mm. The area (segment area) of the cross section perpendicular to the cell extending direction of the honeycomb segment was 1225 mm ² . The length of the honeycomb segment in the cell extending direction was 152.4 mm. The partition wall thickness of the honeycomb segment was 0.3 mm, and the cell density was 46.5 cells / cm ² . Table 1 shows the segment shape, T1, T2, T3 and the segment area.

  As shown in FIG. 11, in the cross section perpendicular to the cell extending direction, the obtained 14 honeycomb segments were joined to the edge of one honeycomb segment 22 with the edge of another honeycomb segment. A honeycomb segment bonded body 23 was fabricated by assembling so that the side edge of another honeycomb segment was bonded to the side edge of the honeycomb segment 22. The bonded honeycomb segment assembly 23 has a cross section perpendicular to the cell extending direction in which the central portion in the longitudinal direction of one honeycomb segment and the “widest portion at the end in the longitudinal direction” of another honeycomb segment are in contact. It has become a state. More specifically, the honeycomb segment bonded body 23 includes a “block (2)” in which two honeycomb segments are bonded at edges, and a “block (3)” in which three honeycomb segments are bonded at edges. “Block (4)” in which four honeycomb segments are joined together at the edges is “block (2), block (3), block (4), block (3), block (2)” in this order. These are joined so that the side edges are in contact with each other. As a bonding material, a mixture of aluminosilicate inorganic fibers and SiC particles was used.

  The outer periphery of the joined honeycomb segment assembly was roughly processed and ground to obtain a desired cylindrical shape. An outer periphery coating process was performed on the honeycomb segment bonded body after the outer periphery processing, and an outer peripheral portion was disposed on the outermost periphery of the honeycomb segment bonded body to obtain a honeycomb structure having a diameter of 143.8 mm as shown in FIG. As the outer periphery coating material, a mixture of SiC particles, colloidal silica and the like was used.

  The obtained honeycomb structure had four “honeycomb segments located in the inner region” as shown in FIG.

  The obtained honeycomb structure was evaluated for “regeneration limit”, “pressure loss”, and “regeneration efficiency” by the following methods.

(Reproduction limit)
First, a predetermined amount of soot (unit: g / L (amount of soot deposited per liter of honeycomb structure)) is deposited on the honeycomb structure, and maintained at an engine speed of 1800 rpm and an engine torque of 90 N · m. Then, injecting the exhaust gas from the engine into the honeycomb structure, post injection is performed. Then, when the pressure difference (pressure loss) between one end and the other end of the honeycomb structure starts to decrease, the post-injection is turned off and the engine is switched to the idle state. At that time, the maximum temperature in the honeycomb structure and the maximum temperature gradient at the end face on the outlet side of the honeycomb structure are measured, and whether or not cracks are generated on the end face on the outlet side of the honeycomb structure is confirmed. When cracks are not generated in the honeycomb structure, the above test was repeated by further increasing the initial soot accumulation amount by 1 g / L, and when cracks occurred on the end face on the outlet side of the honeycomb structure, The maximum temperature gradient of the outlet side end face is defined as an end face crack limit temperature gradient (crack limit) (° C./cm).

(Pressure loss)
The pressure difference (pressure loss) (kPa) between one end and the other end of the honeycomb structure is measured when exhaust gas discharged from the engine flows through the honeycomb structure at an engine speed of 1800 rpm. . The test is performed with no soot deposited on the honeycomb structure.

(Reproduction efficiency)
First, the mass of the honeycomb structure is measured, and then 8 g / L of soot (unit: g / L (the amount of soot deposited per liter of honeycomb structure)) is deposited on the honeycomb structure. Post injection is performed for 10 minutes while exhaust gas from the engine is allowed to flow through the honeycomb structure while maintaining several 1800 rpm and an engine torque of 90 N · m. Then, the remaining soot mass in the honeycomb structure is calculated by measuring the mass of the honeycomb structure, and the soot mass burned during post-injection is calculated compared with the initial soot deposition mass, The ratio of the burned soot mass is the regeneration efficiency (%).

(Examples 2-34, Comparative Examples 1-16)
A honeycomb structure was manufactured in the same manner as in Example 1 except that the segment shape, T1, T2, T3, and the segment cross-sectional area were changed as shown in Table 1. In the same manner as in Example 1, “regeneration limit”, “pressure loss”, and “regeneration efficiency” were evaluated.

  In Table 1, “B shape” in the “Segment shape” column is the shape of the honeycomb segment 205a constituting the honeycomb structure 200 shown in FIG. 5, and in the inner region in the cross section orthogonal to the cell extending direction. The honeycomb segment 205a is positioned as follows: "The edge 10a is formed in a straight line bent at the center so as to be convex outward, and the side edge 13 is formed in a straight line bent at the center so as to be recessed inward. It is a shape. And the edge 10a is the shape which the center protruded most, and the side edge part 13 is the shape where the center was dented most. The honeycomb segment 205a has both a symmetry axis perpendicular to the longitudinal direction and a symmetry axis parallel to the longitudinal direction in a cross section perpendicular to the cell extending direction. The honeycomb segment 205a has a shape in which the edge 10a and the side edge 13 are complementary in a cross section orthogonal to the cell extending direction, and the honeycomb structure 200 includes the edge of one honeycomb segment 205a. 10a and the side edge 13 of the other honeycomb segment 205a are joined.

  In Table 1, “C shape” in the “Segment shape” column is the shape of the honeycomb segment 305a constituting the honeycomb structure 300 shown in FIG. 7, and is in the inner region in the cross section orthogonal to the cell extending direction. The positioned honeycomb segment 305a has a curved shape in which the edge 10a is convex outward, and the side edge 13 is curved inward. And the edge 10a is the shape which the center protruded most, and the side edge part 13 is the shape where the center was dented most. The honeycomb segment 305a has both a symmetry axis perpendicular to the longitudinal direction and a symmetry axis parallel to the longitudinal direction in a cross section perpendicular to the cell extending direction. In the cross section perpendicular to the cell extending direction, the honeycomb segment 305a has a shape in which the edge 10a and the side edge 13 are complementary, and the honeycomb structure 300 includes the edge 10a of one honeycomb segment 205a. The shape is such that the side edge 13 of the other honeycomb segment 205a is joined.

  In Table 1, “Rectangle” in the “Segment shape” column indicates that the shape of the cross section perpendicular to the cell extending direction of the “honeycomb segment located in the inner region” constituting the honeycomb structure is square. Means. The number of “honeycomb segments located in the inner region” was four.

  Table 2 shows the change in the regeneration limit when “T2 / T1” is made constant and the mass of the bag is changed in each segment shape (Examples 1, 2, 3, and Comparative Example 1). Table 3 shows “changes in the regeneration limit when the mass of the bag is constant and the value of“ T2 / T1 ”is changed” in each segment shape. Table 4 shows changes in the regeneration limit when the mass of the soot is changed in the honeycomb structures having the segment shape A and different values of “T2 / T1”. Table 5 shows the “change in the regeneration limit when the mass of the ridge is constant and the segment cross-sectional area is changed” in each segment shape. Table 6 shows “the rate of increase in pressure loss (the rate of increase in pressure loss) when the mass of the bag is constant and the cross-sectional area of the segment is changed” in each segment shape. In Table 6, the pressure loss increase rate is a value based on the pressure loss of Comparative Example 1. Table 7 shows changes in the regeneration limit when the mass of the soot is changed in the honeycomb structures having the segment shape A and different segment cross-sectional areas. Table 8 shows “change in regeneration efficiency when the mass of the soot and the gas temperature are changed” in each segment shape (T2 / T1 = 1.3). Table 9 shows “change in regeneration efficiency when the mass of the soot and the gas temperature are changed” in each segment shape (T2 / T1 = 4.0).

  From Table 1 to Table 9, it can be seen that the honeycomb structures of Examples 1 to 34 have good results for each evaluation of the regeneration limit and regeneration efficiency, and the pressure loss is equivalent to that of the prior art. It can be seen that it is secured. In contrast, in the honeycomb structures of Comparative Examples 1 to 7, it can be seen that the evaluation results of the regeneration limit and regeneration efficiency are poor because the honeycomb segment has a quadrangular cross-sectional shape.

  The method for manufacturing a honeycomb structure of the present invention is suitably used as a carrier for a catalytic device or a filter used for environmental measures or recovery of specific materials in various fields such as chemistry, electric power, and steel. be able to.

1: partition, 2: cell, 3: one end, 4: other end, 5: honeycomb segment, 5a: honeycomb segment located in the inner region, 6: side surface, 7: outer peripheral wall, 8: outer periphery Part: 10: end part, 10a: edge, 11: center part, 12: high temperature region, 13: side edge part, 21: honeycomb formed body, 22: honeycomb segment, 23: joined honeycomb segment, 24: cutting line , 32: honeycomb segment, 33: joined honeycomb segment, 34: cutting line, 100: honeycomb structure.

Claims (6)

A plurality of honeycomb segments having partition walls for partitioning a plurality of cells extending from one end face to the other end face to be a fluid flow path in a state where the side faces are joined,
In the cross section perpendicular to the cell extending direction, the honeycomb segment located in the inner region is formed such that both end portions are formed thicker and gradually become thinner toward the central portion in the longitudinal direction,
In the honeycomb segment located in the inner region in the cross section orthogonal to the cell extending direction, the honeycomb structure satisfying the relationship of the following formula (1) in which the width T1 at the central portion and the width T2 at the end portion .
1.3 ≦ T2 / T1 ≦ 4.0 (1)   In the honeycomb segment located in the inner region in the cross section perpendicular to the cell extending direction, each edge of the both end portions in the longitudinal direction is formed in a convex shape or a straight shape toward the outside, The honeycomb structure according to claim 1, wherein two side edge portions connecting both end edges are formed to be recessed inward.   The honeycomb segment located in the inner region in a cross section perpendicular to the cell extending direction, the two side edge portions are linear or curved at the center. Honeycomb structure.   In a cross section orthogonal to the cell extending direction, the honeycomb segment located in the inner region has a line-symmetric shape with a straight line passing through the central portion in the longitudinal direction and orthogonal to the longitudinal direction as an axis of symmetry. The honeycomb structure according to any one of claims 1 to 3. In a cross section perpendicular to the cell extending direction, the cross-sectional area of the honeycomb segments positioned in the inner region is, the honeycomb structure according to any one of claims 1 to 4 is 1100~1600mm ^2.   The honeycomb structure according to any one of claims 1 to 5, wherein a material of the honeycomb segment is silicon carbide.

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