DE102016003157A1 - honeycomb structure - Google Patents

Abstract

There is disclosed a honeycomb structure of a segment structure which can be easily manufactured and can effectively inhibit the movement of the honeycomb segments due to vibration or exhaust pressure during use. In a first honeycomb segment 2a, the inlet end surface and the outlet end surface are quadrangular and at least a pair of side surfaces in two pairs of side surfaces where each pair of side surfaces face each other have concave side surfaces 6 bent in a concave state in a longitudinal direction of the honeycomb segment and in a second honeycomb segment 2b, the inlet end surface and the outlet end surface are quadrangular, and at least a pair of side surfaces in two pairs of side surfaces where each pair of side surfaces face each other have convex side surfaces 7 in the longitudinal direction of the honeycomb segment convex state, and the first honeycomb segments and the second honeycomb segments are alternately arranged so that the concave side surfaces 6 face the convex side surfaces 7 in at least one direction vertical to the longitudinal direction of the honeycomb segment.

Description

hONEYCOMB STRUCTURE

The present application is an application based on the JP 2015-052496 filed on Mar. 16, 2015 with the Japan Patent Office, the entire contents of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

Field of the invention

The present invention relates to a honeycomb structure for use in a filter for collecting particulates contained in an exhaust gas of a diesel engine or a gasoline engine, a catalyst carrier loaded with a catalyst for purifying the exhaust gas, or the like.

Description of the Related Art

Particulate matter (PM) is contained in the exhaust gas of a gasoline engine such as a diesel engine or a gasoline direct injection (GDI) engine. These PM mainly comprise carbon fines of carbon black and the like, and the PMs are known to be carcinogenic, so that the PMs must be prevented from being discharged into the atmosphere, and therefore strict emission regulations have been imposed on them.

In order to meet these stringent emission regulations, many studies have been made to reduce the amount of PM to be discharged, but the reduction in the amount of PM to be discharged by improving the combustion technology is limited, and the incorporation of a filter into an exhaust system is currently only one effective means for reducing the amount of PM to be discharged.

As the filter for trapping the PM, a wall-flow filter utilizing a honeycomb structure has been widely used since a high PM trapping efficiency can be achieved while suppressing the pressure drop to an allowable range. The honeycomb structure for use in the wall-flow type filter has porous partition walls defining a plurality of cells extending from an inlet end surface, which becomes the inlet side of the exhaust gas, to an outlet end surface, which becomes the outlet side of the exhaust gas. In this honeycomb structure, closure portions closing open ends of predetermined cells on the side of the outlet end surface and open ends of the remaining cells on the side of the inlet end surface are arranged, and thus the filter having a high PM trapping efficiency can be obtained.

That is, the honeycomb structure in which the sealing portions are arranged in this manner becomes a structure in which the exhaust gas flowing into the cells from the inlet end surface passes through the partition walls and then flows out from the outlet end surface to the outside of the cells, and When the exhaust gas passes through the partition walls, the partition walls function as a filtering layer, so that the PM contained in the exhaust gas is caught.

Moreover, in order to be able to use such a filter continuously for a long period of time, the filter must be regularly subjected to a regeneration treatment. That is, for the purpose of reducing the pressure drop which has increased due to the PM deposited in the filter over time, in order to return the filtering power to the initial state, the PM deposited in the filter must be burned and removed with a high-temperature gas. Further, during this regeneration, a high heat load due to the heat of combustion of the PM is generated in the filter, and therefore the filter may be damaged.

In addition, the honeycomb structure is widely used also in a catalyst carrier on which a catalyst for purifying the exhaust gas has been charged. In this case, the high thermal stress is generated by thermal shock due to the high-temperature exhaust gas, and therefore, the catalyst carrier may be damaged.

Heretofore, as a countermeasure for preventing such damage of the filter or the catalyst carrier, it has been proposed that the entire filter or catalyst carrier is not manufactured as a honeycomb structure, but a plurality of honeycomb segments for producing the honeycomb structure for the Filter or the catalyst support are connected. Specifically, a segment structure was made by integrally bonding the plurality of honeycomb segments to a binder material having a low modulus of elasticity and being easy to deform, thereby distributing and attenuating the thermal stress on the honeycomb structure during regeneration, thereby improving thermal shock resistance should be achieved.

When such a honeycomb structure of the segmental structure is used, the filter or catalyst carrier having high thermal shock resistance can be obtained, whereas a new problem typical of the honeycomb structure of the segmented structure occurs. That is, in the filter or the catalyst carrier in which the honeycomb structure of the segment structure is used, there is the problem that it is liable to cause movement (displacement) in the honeycomb segments constituting the honeycomb structure by vibration during use or by Pressure of the exhaust gas (the exhaust pressure) comes. The larger the cross section of each honeycomb segment or the honeycomb structure vertical to the cell passing direction, the larger the problem becomes.

As a means for eliminating this problem, it has been proposed in Patent Document 1 that a honeycomb segment is used which warps in a direction substantially vertical to the longitudinal direction, thereby increasing the resistance force for the exhaust pressure. In addition, it has been proposed in Patent Document 2 that the maximum thickness of a bonding material at a point distant from each end portion by a predetermined distance is set to be larger than the average thickness of the bonding material in a region at the end portion of a bonding material Honeycomb segment is positioned in a central axis direction is. The means described in Patent Document 2 does not have the purpose of eliminating the above problem, but a dented condition is formed in a side surface of the honeycomb segment to change the thickness of the bonding material, and as a result, the movement (displacement) of the bonding material is expected Honeycomb segment is suppressed to some extent. Further, in Patent Document 3, it has been proposed to use a honeycomb segment in which the area of the inlet end face is smaller than the area of the outlet end face, and the bonding width of the bonding material in the inlet end face is set to be larger than the bonding width of the bonding material in FIG the outlet end surface, thereby increasing the structural strength.
[Patent Document 1] WO 2005/047210
[Patent Document 2] WO 2006/126507
[Patent Document 3] WO 2008/096502

SUMMARY OF THE INVENTION

However, there is a limitation to enhancing the bonding force between the honeycomb segments by the means proposed in Patent Documents 1 to 3, and it is difficult to obtain a honeycomb structure having a stable structure to such an extent that movement (displacement) of the honeycomb segments due to vibration or exhaust pressure under the severe conditions of use can be sufficiently inhibited. In addition, in the means proposed in Patent Documents 1 to 3, the thickness (bonding width) of the bonding material in a longitudinal direction of the honeycomb structure must be changed, and therefore, there has been a problem that assembly of the honeycomb structure is difficult. That is, in a step of bonding the honeycomb segments, the control exercise was difficult, so that the thickness of the bonding material in a region changed in comparison with a case where the thickness of the bonding material was set uniformly.

The present invention has been developed in view of such situations, and an object thereof is to provide a honeycomb structure having a segment structure that can be easily assembled and effectively inhibited the movement (displacement) of the honeycomb segments due to vibration or exhaust pressure during use ,

• [1] Eine Wabenstruktur, umfassend mehrere Wabensegmente, die jeweils poröse Trennwände, die mehrere Zellen definieren, die von einer Einlassendfläche, welche eine Einlassseite für ein Fluid wird, zu einer Auslassendfläche, welche eine Auslassseite für das Fluid wird, verlaufen, und eine Außenumfangsfläche, welche die Einlassendfläche mit der Auslassendfläche verbindet, aufweisen, wobei die mehreren Wabensegmente integral über ein Bindematerial verbunden sind, wobei die mehreren Wabensegmente mehrere erste Wabensegmente und mehrere zweite Wabensegmente umfassen, und in dem ersten Wabensegment die Einlassendfläche und die Auslassendfläche viereckig sind und zumindest ein Paar von Seitenflächen bei zwei Paaren von Seitenflächen, bei denen jedes Paar von Seitenflächen einander zugewandt ist, konkave Seitenflächen sind, die in einer Längsrichtung des ersten Wabensegments in einen konkaven Zustand gebogen sind, und in dem zweiten Wabensegment die Einlassendfläche und die Auslassendfläche viereckig sind und zumindest ein Paar von Seitenflächen bei zwei Paaren von Seitenflächen, bei denen jedes Paar von Seitenflächen einander zugewandt ist, konvexe Seitenflächen sind, die in einer Längsrichtung des zweiten Wabensegments in einen konvexen Zustand gebogen sind, und die ersten Wabensegmente und die zweiten Wabensegmente abwechselnd angeordnet sind, so dass die konkaven Seitenflächen den konvexen Seitenflächen in zumindest einer Richtung vertikal zur Längsrichtung des Wabensegments zugewandt sind, und sich die Form der Zellen von zumindest Teilen der mehreren Zellen in einem Querschnitt des Wabensegments, der vertikal zur Längsrichtung des Wabensegments ist, in der Längsrichtung des Wabensegments verändert.
• [2] Die Wabenstruktur nach [1] oben, wobei alle beiden Paare der Seitenflächen der ersten Wabensegmente die konkaven Seitenflächen sind, die in den konkaven Zustand gebogen sind, alle beiden Paare der Seitenflächen der zweiten Wabensegmente die konvexen Seitenflächen sind, die in den konvexen Zustand gebogen sind, und die ersten Wabensegmente und die zweiten Wabensegmente abwechselnd angeordnet sind, so dass die konkaven Seitenflächen den konvexen Seitenflächen in zwei Richtungen vertikal zur Längsrichtung des Wabensegments zugewandt sind.
• [3] Eine Wabenstruktur, umfassend mehrere Wabensegmente, die jeweils poröse Trennwände, die mehrere Zellen definieren, die von einer Einlassendfläche, welche eine Einlassseite für ein Fluid wird, zu einer Auslassendfläche, welche eine Auslassseite für das Fluid wird, verlaufen, und eine Außenumfangsfläche, welche die Einlassendfläche mit der Auslassendfläche verbindet, aufweisen, wobei die mehreren Wabensegmente integral über ein Bindematerial verbunden sind, wobei die mehreren Wabensegmente mehrere Mischkrümmungs-Wabensegmente umfassen, wobei in jedem davon die Einlassendfläche und die Auslassendfläche viereckig sind, ein Paar von Seitenflächen bei zwei Paaren von Seitenflächen, bei denen jedes Paar von Seitenflächen einander zugewandt ist, konkave Seitenflächen sind, die in einer Längsrichtung des Wabensegments in einen konkaven Zustand gebogen sind, und das andere Paar der Seitenflächen konvexe Seitenflächen sind, die in der Längsrichtung des Wabensegments in einen konvexen Zustand gebogen sind, und die mehreren Mischkrümmungs-Wabensegmente so angeordnet sind, dass die konkaven Seitenflächen den konvexen Seitenflächen in zwei Richtungen vertikal zur Längsrichtung des Wabensegments zugewandt sind, und sich die Form der Zellen von zumindest Teilen der mehreren Zellen in einem Querschnitt des Wabensegments, der vertikal zur Längsrichtung des Wabensegments ist, in der Längsrichtung des Wabensegments verändert.
• [4] Die Wabenstruktur nach einem von [1] bis [3] oben, wobei der Krümmungswert sowohl der konkaven Seitenfläche als auch der konvexen Seitenfläche 0,2 bis 3,5 mm beträgt.
• [5] Die Wabenstruktur nach einem von [1] bis [4] oben, wobei die Wabensegmente Verschlussabschnitte aufweisen, die offene Enden der vorbestimmten Zellen auf der Seite der Einlassendfläche und offene Enden der verbleibenden Zellen auf der Seite der Auslassendfläche verschließen.
• [6] Die Wabenstruktur nach einem von [1] bis [5] oben, wobei eine Katalysatorkomponente auf die Trennwände geladen ist.
• [7] Die Wabenstruktur nach einem von [1] bis [6] oben, wobei die mehreren Wabensegmente integral über das Bindematerial verbunden sind und dann einer Umfangsschleifbearbeitung zur Bildung einer Umfangsdeckschicht auf der bearbeiteten Oberfläche unterzogen werden.
• [8] Die Wabenstruktur nach [2] oben, wobei zumindest ein Teil eines Kantenabschnitts, bei dem sich zwei benachbarte konkave Seitenflächen der ersten Wabensegmente schneiden, und zumindest ein Teil eines Kantenabschnitts, bei dem sich zwei benachbarte konvexe Seitenflächen der zweiten Wabensegmente schneiden, abgeschrägt sind.
• [9] Die Wabenstruktur nach einem von [1] bis [8] oben, wobei die Dicke des Bindematerials zwischen den Seitenflächen der benachbarten Wabensegmente einheitlich ist.
• [10] Die Wabenstruktur nach einem von [1] bis [9] oben, wobei die Dicke des Bindematerials das Zweifache oder mehr des Krümmungswertes sowohl der konkaven Seitenfläche als auch der konvexen Seitenfläche beträgt.
• [11] Die Wabenstruktur nach einem von [1] bis [10] oben, wobei der Querschnitt des Wabensegments vertikal zur Zellenverlaufsrichtung eine derartige Größe hat, dass er einen Kreis mit einem Durchmesser von 30 mm enthalten kann.
• [12] Die Wabenstruktur nach einem von [1] bis [11] oben, wobei der Querschnitt der Wabenstruktur vertikal zur Zellenverlaufsrichtung eine derartige Größe hat, dass er einen Kreis mit einem Durchmesser von 200 mm enthalten kann.

In order to achieve the above object, according to the invention, there is provided a honeycomb structure mentioned below.

• [1] A honeycomb structure comprising a plurality of honeycomb segments each having porous partition walls defining a plurality of cells extending from an inlet end surface which becomes an inlet side for a fluid to an outlet end surface which becomes an outlet side for the fluid, and an outer peripheral surface wherein the plurality of honeycomb segments comprise a plurality of first honeycomb segments and a plurality of second honeycomb segments, and in the first honeycomb segment the inlet end surface and the outlet end surface are quadrangular and at least one Pair of side surfaces at two pairs of side surfaces in which each pair of side surfaces face each other are concave side surfaces that are bent in a concave state in a longitudinal direction of the first honeycomb segment, and in the second honeycomb segment the inlet end surface and the outlet end surface are quadrangular and at least one pair of Side surfaces in two pairs of side surfaces in which each pair of side surfaces face each other are convex side surfaces that are bent in a convex state in a longitudinal direction of the second honeycomb segment, and the first honeycomb segments and the second honeycomb segments are alternately arranged, so that concave side surfaces facing the convex side surfaces in at least one direction vertical to the longitudinal direction of the honeycomb segment, and the shape of the cells of at least parts of the plurality of cells in a cross section of the honeycomb segment, which is vertical to the longitudinal direction of the honeycomb segment, in the longitudinal direction changed honeycomb segment.
• [2] The honeycomb structure of [1] above, wherein all two pairs of the side surfaces of the first honeycomb segments are the concave side surfaces bent in the concave state, all two pairs of the side surfaces of the second honeycomb segments are the convex side surfaces that are in the convex Condition are bent, and the first honeycomb segments and the second honeycomb segments are arranged alternately, so that the concave side surfaces facing the convex side surfaces in two directions vertical to the longitudinal direction of the honeycomb segment.
• [3] A honeycomb structure comprising a plurality of honeycomb segments each having porous partition walls defining a plurality of cells extending from an inlet end surface which becomes an inlet side for a fluid to an outlet end surface which becomes an outlet side for the fluid, and an outer peripheral surface having the inlet end surface joined to the outlet end surface, wherein the plurality of honeycomb segments are integrally connected via a binding material, the plurality of honeycomb segments comprising a plurality of composite honeycomb segments, in each of which the inlet end surface and the outlet end surface are quadrangular, a pair of side surfaces at two Pairs of side surfaces in which each pair of side surfaces face each other are concave side surfaces bent into a concave state in a longitudinal direction of the honeycomb segment, and the other pair of side surfaces are convex side surfaces extending in the longitudinal direction of the honeycomb segment in e in the convex state, and the plurality of mixed-curvature honeycomb segments are arranged so that the concave side surfaces face the convex side surfaces in two directions vertical to the longitudinal direction of the honeycomb segment, and the shape of the cells of at least parts of the plurality of cells in a cross section of the Honeycomb segment, which is vertical to the longitudinal direction of the honeycomb segment, changed in the longitudinal direction of the honeycomb segment.
• [4] The honeycomb structure according to any one of [1] to [3] above, wherein the curvature value of both the concave side surface and the convex side surface is 0.2 to 3.5 mm.
• [5] The honeycomb structure according to any one of [1] to [4] above, wherein the honeycomb segments have closure portions that close open ends of the predetermined cells on the inlet end surface side and open ends of the remaining cells on the outlet end surface side.
• [6] The honeycomb structure according to any one of [1] to [5] above, wherein a catalyst component is loaded on the partition walls.
• [7] The honeycomb structure according to any one of [1] to [6] above, wherein the plurality of honeycomb segments are integrally bonded via the bonding material and then subjected to peripheral grinding processing to form a peripheral cover layer on the machined surface.
• [8] The honeycomb structure according to [2] above, wherein at least a part of an edge portion where two adjacent concave side surfaces of the first honeycomb segments intersect, and at least a part of an edge portion where two adjacent convex side surfaces of the second honeycomb segments intersect, bevelled are.
• [9] The honeycomb structure according to any one of [1] to [8] above, wherein the thickness of the bonding material is uniform between the side surfaces of the adjacent honeycomb segments.
• [10] The honeycomb structure according to any one of [1] to [9] above, wherein the thickness of the bonding material is twice or more the curvature value of both the concave side surface and the convex side surface.
• [11] The honeycomb structure according to any one of [1] to [10] above, wherein the cross section of the honeycomb segment vertical to the cell passing direction has a size such that it may include a circle having a diameter of 30 mm.
• [12] The honeycomb structure according to any one of [1] to [11] above, wherein the cross section of the honeycomb structure vertical to the cell passing direction has a size such that it can include a circle having a diameter of 200 mm.

The honeycomb structure of the present invention is constructed such that the shape or arrangement of the honeycomb segments satisfies special conditions, and therefore has a stable structure. Consequently it comes, even when using this honeycomb structure in a filter or catalyst carrier to be installed in an exhaust system, not so easy to move (shift) the honeycomb segments due to vibration or exhaust pressure during use of the filter or the catalyst carrier. This effect is remarkable, especially when the cross section of each honeycomb segment or the honeycomb structure is large vertically to the cell running direction. In addition, the shape of the cells of at least parts of the cells in the cross section of the honeycomb segment varies in a longitudinal direction of the honeycomb segment in the longitudinal direction of the honeycomb segment, and therefore a fluid passing through the cells can easily interfere with the porous partition walls defining the cells Come in contact. Thus, when the honeycomb structure of the present invention is used as a PM trap filter, the PM in the exhaust gas is easily caught by the partition walls constituting a filter layer, and the trap efficiency of the PM improves. Further, when a catalyst component is charged on the partition walls, the exhaust gas can easily come into contact with the catalyst component, and the purification performance of the exhaust gas improves. In addition, in the production of the honeycomb structure of the present invention, no step is required in which the thickness of the bonding material is changed in the longitudinal direction of the honeycomb structure, whereby the assembling of the honeycomb structure would be difficult, and therefore, the honeycomb structure can be manufactured comparatively easily.

BRIEF DESCRIPTION OF THE DRAWINGS

1 Fig. 12 is a schematic perspective view showing an example of a basic structure of a honeycomb structure according to the present invention;

2 10 shows schematic views of a first honeycomb segment for use in an example of an embodiment of the honeycomb structure according to the present invention, (a) is a front view, (b) is a plan view (a top view), (c) is a side view, and (d) is a bottom view;

3 11 shows schematic views of a second honeycomb segment for use in the one example of the embodiment of the honeycomb structure according to the present invention, (a) is a front view, (b) is a plan view (a top view), (c) is a side view and (i ) is a bottom view;

4 10 shows schematic views of a first honeycomb segment for use in another example of the embodiment of the honeycomb structure according to the present invention, (a) is a front view, (b) is a plan view (a top view), (c) is a side view and (i ) is a bottom view;

5 10 shows schematic views of a second honeycomb segment for use in the other example of the embodiment of the honeycomb structure according to the present invention, (a) is a front view, (b) is a plan view (a top view), (c) is a side view and (i ) is a bottom view;

6 12 shows schematic views of a mixed-curvature honeycomb segment for use in still another example of the embodiment of the honeycomb structure according to the present invention, (a) is a front view, (b) is a plan view (a top view), (c) is a side view and FIG (d) is a bottom view;

7 Fig. 12 is a schematic cross-sectional view showing an arrangement state of the first honeycomb segments and the second honeycomb segments;

8th Fig. 12 is a schematic cross-sectional view showing an arrangement state of the mixed-curvature honeycomb segments;

9 Fig. 12 is a schematic explanatory view showing a method of measuring the curvature value of a concave side surface;

10 Fig. 12 is a schematic explanatory view showing a method of measuring the curvature value of a convex side surface;

11 is a schematic cross-sectional view of a honeycomb segment with the concave side surface;

12 is a schematic cross-sectional view of a honeycomb segment with the convex side surface;

13 Fig. 12 is a schematic cross-sectional view showing a state where shutter portions are formed in the honeycomb segment with the concave side surface;

14 Fig. 12 is a schematic cross-sectional view showing a state where closure portions are formed in the honeycomb segment with the convex side surface;

15 Fig. 12 is a schematic explanatory view showing a method of forming the concave side surface;

16 Fig. 12 is a schematic explanatory view showing another method of forming the concave side surface;

17 Fig. 12 is a schematic plan view showing the arrangement of the honeycomb segments in Examples 1 to 9;

18 Fig. 10 is a schematic plan view showing the arrangement of the honeycomb segments in Examples 10 and 11;

19 Fig. 12 is a schematic plan view showing the arrangement of the honeycomb segments in Examples 12 and 13;

20 Fig. 12 is a schematic plan view showing the arrangement of the honeycomb segments in Examples 14 to 27; and

21 FIG. 12 is a schematic plan view showing the arrangement of the honeycomb segments in Examples 28 to 36. FIG.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to the following embodiments, and design changes, improvements and the like may be made appropriately based on the ordinary knowledge of those skilled in the art without departing from the gist of the invention departing.

(1) honeycomb structure:

As in 1 shown comprises a honeycomb structure 1 according to the present invention, a plurality of honeycomb segments 2 that is integral over a binding material 12 are connected. Each of the honeycomb segments 2 has porous partitions 11 containing multiple cells 10 defining an inlet end surface which becomes an inlet side for a fluid, an outlet end surface which becomes an outlet side for the fluid, and an outer peripheral surface which connects the inlet end surface with the outlet end surface. It should be noted that in 1 has been dispensed with the drawing of the partition sections of the honeycomb segments, except for parts of the honeycomb segments.

In an example of an embodiment (hereinafter referred to as "the first embodiment") of the honeycomb structure according to the present invention, the plurality of honeycomb segments 2 that the honeycomb structure 1 form, several first honeycomb segments 2a and a plurality of second honeycomb segments 2 B , 2 and 3 are schematic views of the first honeycomb segment 2a or the second honeycomb segment 2 B for use in the first embodiment. In 2 and 3 (a) is a front view, (b) is a plan view (a top view), (c) is a side view, and (d) is a bottom view. As in 2 are shown in the first honeycomb segment 2a the inlet end surface 3 and the outlet end surface 4 quadrangular, a pair of side surfaces face each other and becomes the outer peripheral surface of two pairs of side surfaces (four side surfaces 5a to 5d in total). Further, in the first honeycomb segment 2a a pair of side surfaces 5a and 5b with two pairs of side surfaces, concave side surfaces 6 in a longitudinal direction of the first honeycomb segment 2a bent into a concave state. Besides, as in 3 shown, even in the second honeycomb segment 2 B , similar to the first honeycomb segment 2a , the inlet end surface 3 and the outlet end surface 4 quadrangular, a pair of side surfaces face each other and becomes the outer peripheral surface of two pairs of side surfaces (four side surfaces 5a to 5d in total). Further, in the second honeycomb segment 2 B a pair of side surfaces 5a and 5b with two pairs of side surfaces, convex side surfaces 7 in a longitudinal direction of the second honeycomb segment 2 B in a convex state are bent. It should be noted that in the present invention, "the concave state" is a state dented toward the inside of the honeycomb segment, and "the convex state" is a state protruding to the outside of the honeycomb segment. However, there is no limitation on a specific curved shape of the concave side surface and the convex side surface, a circular shape, an elliptical shape, a parabolic shape or the like is preferable, and the circular shape is particularly preferable because the honeycomb segment can be easily manufactured. In addition, the longitudinal direction of the honeycomb segment is a direction connecting both end surfaces of the honeycomb segment. In addition, the curvature of the concave side surface is preferably the same as the curvature of the convex side surface. In addition, when the side surface is "bent in the longitudinal direction in the concave state" means that the shape of a cut portion is such a shape that is bent in the concave state when the side surface "with a straight line parallel to the longitudinal direction, perpendicular to a virtual side surface, if it is assumed that the side surface is not bent "is cut. In addition, this also applies if the side surface "bent in the longitudinal direction in the convex state".

As in 7 shown are the first honeycomb segments 2a and the second honeycomb segments 2 B alternately arranged so that the concave side surfaces 6 the convex side surfaces 7 in one direction (an X direction or a Y direction of 1 ) are directed vertically to the longitudinal direction of the honeycomb segment. In this way, the honeycomb segments are arranged so that the concave side surface 6 of the first honeycomb segment 2a and the convex side surface 7 of the second honeycomb segment 2 B that is, side surfaces having complementary shapes face each other, thereby obtaining a state where the two side surfaces are precisely matched. In addition, the side surfaces which become joint surfaces between the honeycomb segments are bent, and therefore, the bonding area increased as compared with a case where the side surfaces are flat surfaces. As a result, the fixing force between the first honeycomb segment increases 2a and the second honeycomb segment 2 B which are juxtaposed, and the honeycomb structure is formed with a strong structure. Consequently, even if the honeycomb structure of the present invention is used in a filter or a catalyst carrier to be installed in an exhaust system of a diesel engine or a gasoline engine, the honeycomb segments hardly move (shift) due to vibration or exhaust pressure during use of the filter or catalyst support.

In addition, when the honeycomb segments are arranged so that the concave side surface 6 of the first honeycomb segment 2a and the convex side surface 7 of the second honeycomb segment 2 B that is, the side surfaces with the complementary shapes face each other, the binding material 12 have a uniform thickness. That is, in the production of the honeycomb structure, no step is required in which the thickness of the bonding material in the longitudinal direction of the honeycomb structure is changed, whereby the assembly of the honeycomb structure becomes difficult as in the honeycomb structures described in Patent Documents 1 to 3. and therefore, the honeycomb structure of the present invention can be manufactured comparatively easily.

Next, another example of the embodiment (hereinafter referred to as "the second embodiment") of the honeycomb structure according to the present invention will be described. 4 and 5 Fig. 3 are schematic views of a first honeycomb segment 2a or a second honeycomb segment 2 B for use in the second embodiment of the present invention. In 4 and 5 (a) is a front view, (b) is a plan view (a top view), (c) is a side view, and (d) is a bottom view. As in 4 are shown in the first honeycomb segment 2a the inlet end surface 3 and the outlet end surface 4 square and becomes the outer circumferential surface of two pairs of side surfaces (four side surfaces 5a to 5d overall) in which each pair of side surfaces face each other is formed. Further, in the first honeycomb segment 2a all two pairs of side surfaces 5a and 5b and 5c and 5d concave side surfaces 6 in a longitudinal direction of the first honeycomb segment 2a bent into a concave state. Besides, as in 5 shown, even in the second honeycomb segment 2 B , similar to the first honeycomb segment 2a , the inlet end surface 3 and the outlet end surface 4 square and becomes the outer circumferential surface of two pairs of side surfaces (four side surfaces 5a to 5d in total), in which each pair of side surfaces faces each other. Further, in the second honeycomb segment 2 B all two pairs of side surfaces 5a and 5b and 5c and 5d convex side surfaces 7 in a longitudinal direction of the second honeycomb segment 2 B bent into a convex state.

As in 7 shown are the first honeycomb segments 2a and the second honeycomb segments 2 B alternately arranged so that the concave side surfaces 6 the convex side surfaces 7 in two directions (the X direction and the Y direction of 1 ) are directed vertically to the longitudinal direction of the honeycomb segment. In this way, the honeycomb segments are arranged so that the concave side surface 6 of the first honeycomb segment 2a and the convex side surface 7 of the second honeycomb segment 2 B , ie, side surfaces with complementary shapes, facing each other, whereby a state is obtained in which the two side surfaces are precisely matched. Also in the second embodiment, an effect basically similar to that of the first embodiment can be obtained. In addition, in the second embodiment, the concave side surfaces 6 to the convex side surfaces 7 is exactly matched in the two directions vertical to the longitudinal direction of the honeycomb segment, and therefore, the honeycomb structure is formed with an even stronger structure as compared with the first embodiment.

It should be noted that if the arrangement space between the first honeycomb segment 2a and the second honeycomb segment 2 B is excessively small, the adjacent first honeycomb segments 2a or the adjacent second honeycomb segments 2 B can interfere with each other in an edge portion in a diagonal direction of each of the end surfaces of the honeycomb segments. In the case of the first honeycomb segments 2a For example, the "edge portion" mentioned herein is an area where two concave side surfaces 6 which are adjacent (but not facing each other), intersect (contact each other), and in the case of the second honeycomb segments 2 B the edge portion is an area where two convex side surfaces 7 which are adjacent (but not facing each other), intersect each other (come in contact with each other). In order to prevent such interference, in the second embodiment, the edge portion where the two adjacent concave side surfaces are 6 the first honeycomb segments 2a cut, and at least part of the edge portion, in which the two adjacent convex side surfaces 7 the second honeycomb segments 2 B cut, preferably bevelled. The chamfering of the edge portion may be R-chamfering or C-chamfering.

Next, still another example of the embodiment (hereinafter referred to as "the third embodiment") of the honeycomb structure according to the present invention will be described. In the third embodiment, a plurality of honeycomb segments 2 forming the honeycomb structure, a plurality of mixed curvature honeycomb segments 2c , 6 is a schematic view of the mixed curvature honeycomb segment 2c for use in the third embodiment. In 6 (a) is a front view, (b) is a plan view (a top view), (c) is a side view, and (d) is a bottom view. As in 6 are shown in the mixed curvature honeycomb segment 2c the inlet end surface 3 and the outlet end surface 4 square and becomes the outer circumferential surface of two pairs of side surfaces (four side surfaces 5a to 5d in total), in which each pair of side surfaces faces each other. Further, in the mixed-curvature honeycomb segment 2c a pair of side surfaces 5a and 5b with two pairs of side surfaces, concave side surfaces 6 in a longitudinal direction of the mixed-curvature honeycomb segment 2c bent into a concave state. In addition, in the mixed-curvature honeycomb segment 2c the other pair of side surfaces 5c and 5d convex side surfaces 7 in the longitudinal direction of the mixed-curvature honeycomb segment 2c bent into a convex state. That is, the mixed-curvature honeycomb segment 2c for use in this embodiment has both the concave side surface 6 as well as the convex side surface 7 on.

As in 8th Shown are the plurality of mixed curvature honeycomb segments 2c arranged so that the concave side surfaces 6 the convex side surfaces 7 in two directions vertical to the longitudinal direction of the honeycomb segment (the X direction and the Y direction of 1 ) are facing. That is, the honeycomb segments are arranged so that the concave side surface 6 a mixed curvature honeycomb segment 2c and the convex side surface 7 of the other mixed-curvature honeycomb segment 2c that is, the side surfaces having the complementary shapes face each other in a relationship between the adjacent mixed-curvature honeycomb segments. When the honeycomb segments are arranged in this way, the concave side surface is 6 of a mixed-curvature honeycomb segment 2c exactly matching the convex side surface 7 of the other mixed-curvature honeycomb segment 2c , Also in this third embodiment, an effect basically similar to that of the first embodiment can be obtained. In this third embodiment, however, similar to the second embodiment, the concave side surfaces 6 to the convex side surfaces 7 in two directions vertical to the longitudinal direction of the honeycomb segment is exactly matched, and therefore, the honeycomb structure is formed with an even stronger structure than the first embodiment. Moreover, in the third embodiment, only by the honeycomb segments having the same shape (the mixed-curvature honeycomb segments) instead of combinations of the honeycomb segments having different shapes (the first honeycomb segments and the second honeycomb segments), a similar effect as in the first and second embodiments can be obtained.

It should be noted that in the first and second embodiments, the plurality of honeycomb segments 2 that the honeycomb structure 1 form honeycomb segments other than the first honeycomb segments 2a and the second honeycomb segments 2 B may include. Similarly, in the third embodiment, the plurality of honeycomb segments 2 that the honeycomb structure 1 form honeycomb segments other than the mixed curvature honeycomb segments 2c include. For example, the outermost extent of the machined Honeycomb positioned honeycomb segments by a later-mentioned peripheral grinding processing process of the honeycomb structure have a shape that is different from that of the other honeycomb segments. In such a case, the outermost peripheral honeycomb segments are different from the first honeycomb segment, the second honeycomb segment, and the mixed-curvature honeycomb segment, however, a honeycomb-comprising honeycomb structure is also included in the present invention. In addition, parts of the honeycomb segments 2 that the honeycomb structure 1 form, ordinary quadrangular prismatic columnar honeycomb segments whose side surfaces are not bent.

When the honeycomb structure of the present invention is used in the filter or catalyst carrier to be installed in the exhaust system, the effect of inhibiting the movement (displacement) of the honeycomb segments due to vibration or exhaust pressure during use is remarkable, especially when the cross section of the honeycomb segment or the honeycomb structure is large vertically to the cell running direction. Consequently, in each of the embodiments, the cross section of the honeycomb segment 2 vertical to the direction of the cells 10 preferably such a size that a circle with a diameter of 30 mm may be included. In addition, the cross section of the honeycomb structure 1 vertical to the direction of the cells 10 preferably such a size that a circle with a diameter of 200 mm may be included.

In addition, in each of the embodiments, the shape of the cells of at least parts of the plurality of cells defined by the partition walls in the cross section of the honeycomb segment changes vertically to the longitudinal direction of the honeycomb segment (hereinafter referred to as the "cell shape") in the longitudinal direction of the honeycomb segment. That is, even with a honeycomb segment 2 with concave side surfaces 6 , as in 11 shown, and a honeycomb segment 2 with convex side surfaces 7 , as in 12 shown are at least parts of the partitions 11 bent. Consequently, the cell shape of at least the parts of the cells 10 not constant, but changes in the longitudinal direction of the honeycomb segment 2 , In this way, the cell shape of at least the parts of the cells changes 10 in the longitudinal direction of the honeycomb segment, and therefore, the fluid containing the cells 10 happens easily with the porous partitions 11 that the cells 10 define, be brought into contact. Consequently, in a case where the honeycomb structure of the present invention is used as a PM trap filter, PM in an exhaust gas is easily caught by the partition walls constituting a filter layer, and the PM trap efficiency improves. In addition, as described later, when a catalyst component is applied to the partitions 11 is charged, the exhaust gas easily come into contact with the catalyst component, and the purification performance of the exhaust gas is improved.

Further, in each of the embodiments, the curvature value of the concave side surface is 6 and the convex side surface 7 preferably 0.2 to 3.5 mm, more preferably 0.3 to 3 mm and particularly preferably 0.5 to 2 mm. Here, "the curvature value" is a value measured as follows when the honeycomb segment having the concave side surfaces and / or the convex side surfaces is mounted on a flat plate. For the curvature value of the concave side surface, as in 9 shown is the honeycomb segment 2 on a flat plate 15 mounted so that the concave side surface 6 of the honeycomb segment 2 the surface of the flat plate 15 is facing to the maximum distance D between the flat plate 15 and the concave side surface 6 to measure, and the maximum distance is the curvature value of the concave side surface 6 Are defined. Also, for the curvature value of the convex side surface, as in 10 shown the honeycomb segment 2 on the flat plate 15 mounted so that the convex side surface 7 of the honeycomb segment 2 the surface of the flat plate 15 is facing to the maximum distance D between the flat plate 15 and the convex side surface 7 to measure, and the maximum distance is calculated as the curvature value of the convex side surface 7 Are defined. Will the honeycomb segment 2 on the flat plate 15 mounted as in 9 and 10 shown, the honeycomb segment must be arranged so that the cell running direction of the honeycomb segment 2 parallel to the surface of the flat plate 15 is. It should be noted that, in a case where the edge portion where the two adjacent convex side surfaces intersect, R-beveled, or C-bevel, the measurement is performed in a portion corresponding to a boundary between the convex side surface and the surface R-chamfered section or the C-chamfered section. Is the curvature value of the concave side surface 6 and the convex side surface 7 smaller than 0.2 mm, the movement of the honeycomb segments sometimes can not be sufficiently inhibited due to vibration or exhaust pressure. In addition, when the curvature value of the concave side surface increases 6 and the convex side surface 7 Exceeds 3.5 mm, the pressure drop of the honeycomb structure 1 to, and there may be a reduction in engine performance when the honeycomb structure is used as a PM trap filter to be installed in the exhaust system of the engine.

The material of the honeycomb segments 2 that the honeycomb structure 1 of the present invention preferably comprises as a main component at least one selected from the group consisting of Cordierite, silicon carbide, mullite, aluminum titanate, zeolite, vanadium and alumina. Here, "major component" means a component that accounts for more than 50% by mass of the total material.

The average pore diameter of the partitions 11 of the honeycomb segment 2 is preferably 5 to 100 microns and more preferably 8 to 50 microns. Is the average pore diameter of the partitions 11 smaller than 5 μm, the pressure drop of the honeycomb structure increases 1 and engine power may be reduced when the honeycomb structure is used as the PM trap filter to be installed in the exhaust system of the engine. Also, if the average pore diameter of the partitions 11 Exceeds 100 μm, sometimes sufficient strength can not be obtained. It is understood that the "average pore diameter" mentioned herein is a value measured with a mercury porosimeter.

The porosity of the partitions 11 of the honeycomb segment 2 is preferably 30 to 80% and more preferably 35 to 75%. Is the porosity of the partitions 11 less than 30%, the pressure drop of the honeycomb structure increases 1 and engine power may be reduced when the honeycomb structure is used as the PM trap filter to be installed in the exhaust system of the engine. Besides, if the porosity of the partitions 11 80%, sometimes insufficient strength is obtained. It should be understood that the "porosity" referred to herein is a value measured with a mercury porosimeter.

The thickness of the partitions 11 of the honeycomb segment 2 is preferably 40 to 600 microns and more preferably 100 to 400 microns. Is the thickness of the partitions 11 less than 40 microns, may not be obtained sufficient strength. It also increases when the thickness of the partitions 11 Exceeds 600 μm, the pressure drop of the honeycomb structure 1 and engine power may be reduced when the honeycomb structure is used as the PM trap filter to be installed in the exhaust system of the engine.

In the present invention, the thickness of the binding material is 12 containing the several honeycomb segments 2 integrally connects, preferably 0.05 to 8.0 mm. In addition, the thickness of the binding material 12 preferably uniform between the side surfaces of the adjacent honeycomb segments. Furthermore, the thickness of the binding material is 12 preferably twice or more of the curvature value of both the concave side surface and the convex side surface. In this way, when the thickness of the binding material occur 12 greater than a certain degree, such interference of the honeycomb segments with each other in the edge portion as described above is hardly noticeable. The binding material 12 is not particularly limited to a material, but an example of the material is preferably a material in which ceramic particles or inorganic fibers of silicon carbide, alumina, silicon nitride or the like are bonded by colloidal silica or colloidal alumina. The bonding material of such a material can effectively alleviate thermal stress as the thermal stress is generated in the honeycomb structure.

There is no particular restriction on the shape (outer shape) of the honeycomb structure 1 of the present invention, and examples of the mold include a round columnar shape, an elliptic columnar shape, and a polygonal prismatic columnar shape. It is understood that in the honeycomb structure of the present invention to obtain the desired shape, the plurality of honeycomb segments are preferably bonded to the bonding material and then subjected to the peripheral grinding processing. By this peripheral grinding, the honeycomb segments positioned at the outermost circumference of the processed honeycomb structure have a different shape than the other honeycomb segments (hereinafter referred to as the "complete segments"). That is, a part of each honeycomb segment positioned at the outermost periphery of the honeycomb structure is removed by the peripheral grinding processing, and therefore the honeycomb segment has the shape of the complete honeycomb segment in which the removed part has been omitted. The machined surface after the peripheral grinding processing (the outer peripheral surface of the honeycomb structure) has such a state that the cells are exposed, and therefore, preferably, a peripheral cover layer 13 formed on the machined surface, as in 1 shown. As the molding material of the peripheral cover layer 13 it is preferable to use the same material as the molding material of the bonding material.

In the present invention, however, there is no particular limitation on the honeycomb segment cell shape, but the shape is a polygonal shape such as a quadrangular shape, a hexagonal shape or an octagonal shape or any combination of these shapes, and for example, the combination of the quadrangular shape and the octagonal shape preferred.

When the honeycomb structure of the present invention is used in the PM trap filter, as in FIG 13 and 14 Shown are preferably closure sections 14 formed, the open ends of predetermined cells 10a on the side of the inlet end surface 3 and open ends of remaining cells 10b on the side of the outlet end surface 4 close. In this way, the open end of each cell 10 of the honeycomb segment 2 with the closure section 14 closed, and therefore, the honeycomb structure is a wall-flow filter with a high PM collecting efficiency. In this wall-flow filter, an exhaust gas passes into the cells 10 ( 10b ) from the inlet end surface 3 flows, the partitions 11 and then flows out of the outlet end surface 4 to the outside of the cells 10 ( 10a ). Further, when the exhaust gas is the partition walls 11 happens, the partitions 11 as a filter layer, and the PM contained in the exhaust gas are collected. It is understood that the closure sections 14 are preferably formed in such an arrangement that the inlet end face 3 and the outlet end surface 4 have a mosaic-like pattern that passes through the cells 10 whose open ends with the closure sections 14 are closed, and the cells 10 whose open ends do not match the closure sections 14 are closed, is formed.

The material for the closure sections 14 is preferably a material that serves as a preferred material for the honeycomb segments 2 is looked at. The material for the closure sections 14 may be the same or different than the material for the honeycomb segments 2 be.

In the honeycomb segments 2 that the honeycomb structure 1 of the present invention, a catalyst component may be applied to the partition walls 11 be loaded. There is no particular limitation on the type of the catalyst component, but if the honeycomb structure is used in a utilization application for purifying an automobile exhaust gas, a noble metal is preferably used. The noble metal is preferably platinum, rhodium or palladium or any combination of these metals.

The catalyst component of the noble metal or the like is applied to the partition walls in a finely divided state 11 charged, and therefore, the catalyst component is once preferably preferably applied to a heat-resistant inorganic oxide having a large specific surface area, e.g. As alumina, and then on the partitions 11 the honeycomb structure 1 loaded. It is understood that, as the heat-resistant inorganic oxide to which the catalyst component has been charged, according to the use application, besides aluminum oxide, zeolite or the like is usable. In addition, the catalyst component of the noble metal or the like may be immobilized on an auxiliary catalyst of ceria, zirconia or a composite oxide thereof and then on the partition walls 11 the honeycomb structure 1 getting charged.

(2) Production Method of Honeycomb Structure:

An example of a manufacturing method for the honeycomb structure according to the present invention will be described. First, for the purpose of producing the honeycomb segment, a molding raw material containing a ceramic raw material is produced. The ceramic raw material contained in the molding raw material is preferably at least one selected from the group consisting of a cordierite-forming raw material, cordierite, silicon carbide, a silicon-silicon carbide-based composite material, mullite, aluminum titanate, zeolite and vanadium. It is understood that the cordierite-forming raw material is a ceramic raw material mixed into a chemical composition in which silica falls within a range of 42 to 56 mass%, alumina falls within a range of 30 to 45 mass% and magnesium oxide falls in a range of 12 to 16 mass%. The cordierite-forming raw material is fired to become cordierite.

The molding raw material is preferably prepared by mixing such a above-mentioned ceramic raw material with a dispersing medium, an organic binder, an inorganic binder, a pore former, a surface active agent, and the like. There is no specific restriction on the composition ratio of each raw material, and the composition ratio is preferably set according to the structure, material and the like of the honeycomb structure to be manufactured.

Next, the molding raw material is kneaded to form a kneaded material. There is no specific limitation on a method for kneading the molding raw material to form the kneaded material. An example of the method is preferably a method using a kneader, a vacuum kneader or the like.

Next, the kneaded material is extruded to produce a honeycomb formed body. Here, the honeycomb formed body to be extruded has a quadrangular prismatic columnar outer shape whose both end faces are consistently quadrangular. Subsequently, predetermined side surfaces of this honeycomb formed body are bent. For example, when the first honeycomb segment is manufactured in the above first embodiment, a pair of side surfaces are bent into a concave state in two pairs of side surfaces in which each pair of side surfaces face each other. When the second honeycomb segment is manufactured in the first embodiment, a pair of side surfaces are bent into a convex state in two pairs of side surfaces in which each pair of side surfaces face each other. When the first honeycomb segment is manufactured in the above second embodiment, all four side surfaces are bent into the concave state. When the second honeycomb segment is manufactured in the second embodiment, all four side surfaces are bent to the convex state. When the mixed-curvature honeycomb segment is manufactured in the above third embodiment, a pair of side surfaces are bent into the concave state with two pairs of side surfaces in which each pair of side surfaces face each other, and the other pair of side surfaces are bent into the convex state ,

There is no particular limitation to a method for bending the predetermined side surfaces of the honeycomb formed body. However, in the present invention, as described above, the cell shape of at least parts of the plurality of cells defined by the partition walls must change in the longitudinal direction of the honeycomb segment. Consequently, a method must be used in which also at least parts of the partition walls are bent when the side surfaces are bent, and as a result, the cell shape of at least the parts of the cells in the longitudinal direction of the honeycomb segment changes.

An example of a method for bending the predetermined side surface of the honeycomb formed body into the concave state is suitably a method of pressing a plate 18 with a convex surface 19 on a predetermined side surface 17 a honeycomb formed body 16 so that the side surface 17 is deformed in the concave state, as in 15 shown. It is understood that two plates each having a convex surface can be produced and the two plates can be pressed simultaneously on two facing side surfaces of the honeycomb formed body, so that these two side surfaces are simultaneously deformed into the concave state. Besides, as in 16 shown the side surface 17 in the concave state by moving a roller 20 while the roller is on the predetermined side surface 17 of the honeycomb formed body 16 is pressed, deformed. An example of a suitable method for bending the predetermined side surface of the honeycomb formed body into the convex state or a suitable method for bending the predetermined side surface of the honeycomb formed body into the concave state is a method of sucking the predetermined side surface of the honeycomb formed body. Specifically, the predetermined side surface of the honeycomb formed body is preferably covered with a lid-like box having a top in a convex state or a concave state, and the air in the box (air in a space defined between the predetermined side surface of the honeycomb formed body and the convex or concave top the lid-like box is formed) is preferably sucked with a vacuum pump or the like, whereby the side surface deforms in the convex state or the concave state. In addition, a resin plate may come into tight contact with the predetermined side surface of the honeycomb formed body, and the resin plate may be sucked by a vacuum pump or the like so that a middle portion or each end portion of the honeycomb formed body lifts in a direction opposite to the honeycomb formed body, thereby lifting the side surface deforms into the convex state or the concave state. It is understood that, in cases where the method of suctioning the predetermined side surface of the honeycomb formed body is used, air may be blown from a compressor or the like into the cells of the honeycomb formed body simultaneously with the suction. Consequently, the honeycomb formed body can be easily deformed. In addition, two boxes or resin plates as described above can be manufactured, and two side surfaces of the honeycomb formed body facing each other can be sucked simultaneously so that these two side surfaces are simultaneously deformed into the convex state or the concave state.

Therefore, the predetermined side surfaces are bent into the concave state or the convex state, and then the honeycomb formed body is dried. There is no particular restriction on the drying process. Examples of a suitable drying process include hot air drying, microwave drying, induction drying, decompression drying, vacuum drying and freeze drying. Among these methods, induction drying, microwave drying or hot air drying is preferably carried out alone, or preferably any combination of these methods is performed.

Next, the dried honeycomb formed body (the dried honeycomb) is fired to produce the honeycomb segment. It is understood that prior to this firing (main firing), calcining (degreasing) is preferably performed for removing the binder and the like contained in the honeycomb formed body. There is no particular restriction on calcination conditions, and the Conditions can be defined so that organic substances (the organic binder, the surfactant, the pore builder, etc.) contained in the honeycomb formed body can be removed. In general, the firing temperature of the organic binder is about 100 to 300 ° C, and the firing temperature of the pore-forming agent is about 200 to 800 ° C. Thus, as the calcining conditions, it is preferable to conduct heating at about 200 to 1000 ° C in an oxidizing atmosphere for about 3 to 100 hours. The conditions (temperature, time, atmosphere, etc.) for firing the honeycomb formed body (the main firing) vary with the kind of the molding raw material, and therefore suitable conditions can be selected according to its kind. For example, when the cordierite-forming raw material is used, the firing temperature is preferably 1,410 to 1,440 ° C. In addition, the burning time is preferably 4 to 8 hours, as the time for holding the highest temperature. There is no particular limitation on a device that performs calcining or firing. Examples of suitable apparatus include an electric furnace and a gas furnace.

In the manufacture of the honeycomb structure comprising the closure portions, the closure portions are formed in the honeycomb segment. The sealing portions are formed so as to close open ends of predetermined cells on one end surface side (inlet end surface) and open ends of the remaining cells on the other end surface side (outlet end surface). The closure portions are formed using a previously known method. As an example of a specific method, a film is first attached to the end surface of the honeycomb segment made by a method as described above. Next, holes are made at locations of this film corresponding to the cells in which the closure portions are to be formed. Next, in a state in which this film was still attached, the end surface of the honeycomb segment is immersed in a sealing slurry in which the molding material of the sealing portions is slurried, and the sealing slurry is passed through the holes formed in the film into each of the open ends filled the cells to be closed. The thus-filled closure slurry is dried and then fired to cure, thereby forming the closure portions. In the molding material of the sealing portions, it is preferable to use the same material as the molding material of the honeycomb segment. It will be understood that the closure portions may be formed at any stage after drying, calcining or firing (main firing) of the honeycomb formed body.

Thus, the first honeycomb segments having the concave side surfaces, the second honeycomb segments having the convex side surfaces, and the mixed curving honeycomb segments having the concave side surfaces and the convex side surfaces are manufactured.

Next, the side surfaces of each honeycomb segment obtained are coated with a slurried bonding material, and the plurality of honeycomb segments are combined so that the side surfaces of the honeycomb segments are bonded together with the bonding material. Here, when manufacturing the honeycomb structure of the above first embodiment, the first honeycomb segments and the second honeycomb segments are alternately combined so that the concave side surfaces face the convex side surfaces in a direction vertical to the longitudinal direction of each honeycomb segment. Further, when the honeycomb structure of the above second embodiment is manufactured, the first honeycomb segments and the second honeycomb segments are alternately combined so that the concave side surfaces face the convex side surfaces in two directions vertical to the longitudinal direction of the honeycomb segment. In addition, when the honeycomb structure of the above third embodiment is manufactured, the mixed-curvature honeycomb segments are combined with each other so that the concave side surfaces face the convex side surfaces in two directions vertical to the longitudinal direction of the honeycomb segment. The plural honeycomb segments are combined in this manner, and the bonding material is heated and dried, so that the honeycomb structure in which the plurality of honeycomb segments are integrally bonded via the bonding material can be obtained.

As the binder material, for example, a material may suitably be used in which additives such as an organic binder, a foamable resin and a dispersant and water are added to a inorganic inorganic fiber, colloidal silica, clay, ceramic particle or the like inorganic raw material to be kneaded and slurried becomes. There is no particular limitation to a method of coating the side surfaces of the honeycomb segments with the binding material, and a brush-brushing method or the like may be used.

The plural honeycomb segments are bonded to the bonding material, and then, as required, a peripheral portion of the obtained honeycomb structure is ground and worked to obtain a desired shape such as a round columnar shape. In this case, the peripheral cover layer is preferably formed on the ground and machined peripheral portion (the machined surface).

The peripheral cover layer is formed by coating the machined surface of the ground and finished honeycomb structure with the peripheral coating material. As the peripheral coating material, a material is suitably used in which additives such as an organic binder, a foamable resin and a dispersant and water were added to an inorganic inorganic fiber, colloidal silica, clay, ceramic particle or the like inorganic raw material to be kneaded and slurried. There is no particular limitation to a method of coating the processed surface of the honeycomb structure with the circumferential coating material. An example of a suitable method is a method in which the machined surface of the ground and processed honeycomb structure is coated with the circumferential coating material with a rubber spatula or the like while the honeycomb structure is being rotated on a lathe.

(Examples)

Hereinafter, the present invention will be described in detail based on examples, but the present invention is not limited to these examples.

(Example 1)

80 mass parts of SiC powder and 20 mass parts of metal Si powder were mixed to obtain a ceramic raw material. To the obtained ceramic raw material, a pore-forming agent, a binder, a surfactant and water were added, whereby a molding raw material was produced, and the molding raw material was kneaded to obtain a kneaded material. Starch was used as the pore former. In addition, methylcellulose and hydroxypropoxylmethylcellulose were used as the binder. As the surfactant, sodium laurate was used. The amounts of the respective raw materials to be added to 100 parts by mass of the ceramic raw material were 5 parts by weight of pore former, 3 parts by weight of methylcellulose, 3 parts by weight of hydroxypropoxylmethylcellulose, 1 part by mass of surface active agent and 32 parts by mass of water.

The obtained kneaded material was extruded using a die for the honeycomb body, thereby obtaining a honeycomb formed body having both end surfaces of a quadrangular prismatic columnar outer shape which was a matching quadrangular shape. In the honeycomb formed body thus obtained, a pair of side surfaces were sucked in two pairs of side surfaces in which each pair of side surfaces face each other by a method in which a lid-like box was used, as described above, whereby the side surfaces deformed into a concave state, and this shaped body was defined as a shaped body for a first honeycomb segment. In addition, in another honeycomb formed body obtained in the same manner, a pair of side surfaces in two pairs of side surfaces in which each pair of side surfaces face each other were sucked by the above method in which the lid-like box was used, thereby forming the side surfaces deformed into a convex state, and this shaped body was defined as a shaped body for a second honeycomb segment. Thereafter, these shaped bodies were dried with microwaves and hot air, whereby dried bodies for the first honeycomb segments were obtained from the moldings for the first honeycomb segments, and dried bodies for the second honeycomb segments were obtained from the moldings for the second honeycomb segments.

Next, a sealing portion was formed in one of the open ends of each cell of each of the dried bodies. The closure portions were formed so that both end surfaces of each dried body had a mosaic-like pattern due to cells in which the closure portions were formed in the open ends and cells in which the closure portions in the open ends were not formed. As a molding method for the sealing portion, a film was first attached to the end surface of the dried body, and holes were formed at positions of this film corresponding to the cells in which the sealing portions are to be formed. Then, in a state in which this film was still attached, the end surface of the dried body was immersed in a sealing slurry in which the molding material of the sealing portions was slurried, and the sealing slurry was passed through the holes formed in the film into each of the open ends filled the cells to be closed. In addition, in the molding material of the sealing portions, the same material as the above molding raw material was used.

Thus, the sealing slurry filled in the open ends of the cells was dried, and then these dried bodies were calcined (defatted) at about 400 ° C in the atmosphere. Thereafter, the dried bodies were fired at about 1450 ° C in an inert Ar atmosphere, whereby the first Honeycomb segments were obtained from the dried bodies for the first honeycomb segments and the second honeycomb segments were obtained from the dried bodies for the second honeycomb segments. Each of the first honeycomb segments thus obtained had the in 2 That is, a pair of side surfaces in two pairs of side surfaces in which each pair of side surfaces face each other were concave side surfaces bent in a concave state in a longitudinal direction of the first honeycomb segment and the other pair of side surfaces flat surfaces. In addition, every other honeycomb segment had the in 3 That is, a pair of side surfaces in two pairs of side surfaces in which each pair of side surfaces face each other were convex side surfaces bent in a convex state in a longitudinal direction of the second honeycomb segment and the other pair of side surfaces flat surfaces. In the first honeycomb segment, the cross section of its central portion in the longitudinal direction vertical to the longitudinal direction had a square shape of 45 mm × 45 mm, the thickness of the partition walls was 200 μm, the cell shape was square, and the cell density was 47 cells / cm ² . In the second honeycomb segment, both end surfaces (an inlet end surface and an outlet end surface) had a square shape of 45 mm x 45 mm, the thickness of the partition walls was 200 μm, the cell shape was square, and the cell density was 47 cells / cm ² . The curved shape of each concave side surface of the first honeycomb segment and the curved shape of each convex side surface of the second honeycomb segment had mutually complementary circular shapes, and the curvatures of these side surfaces were approximately the same. The circle centers of the circular concave side surface and convex side surface were in a plane vertical to the longitudinal direction of the honeycomb segment at a central position of the longitudinal direction of the honeycomb segment. In addition, both the curvature value of the concave side surface of the first honeycomb segment and the curvature value of the convex side surface of the second honeycomb segment were 1 mm. Further, the partitions of parts of these honeycomb segments were bent in the longitudinal direction of the honeycomb segment, and the cell shape of parts of the cells changed in the longitudinal direction of the honeycomb segment. The first honeycomb segments and the second honeycomb segments had a length of 215 mm, and the porosity of the partition walls was 50%. In addition, the thickness of each of the four side surfaces of the honeycomb segment was 0.5 mm.

Subsequently, silica fibers, an organic binder and water were added to an alumina powder to obtain a slurried binder. This binding material was applied to the side surfaces of the first honeycomb segment and the second honeycomb segment to give a thickness of about 1 mm. Next, the first honeycomb segments and the second honeycomb segments were alternately combined so that the concave side surfaces faced the convex side surfaces in a direction vertical to the longitudinal direction of the honeycomb segment. Thus, a honeycomb segment composite body was made comprising a total of 25 honeycomb segments attached as 5 segments x 5 segments. Further, the honeycomb segment composite body was dried at 120 ° C for 2 hours to obtain a joined honeycomb segment body, while the honeycomb segments constituting the honeycomb segment composite body were pressed together by, e.g. B. in a suitable external pressure was exerted on it. 17 Fig. 12 is a schematic plan view showing the arrangement of the honeycomb segments in this joined honeycomb segment body. As in 17 shown, the first honeycomb segments with the in 2 shown shape and the second honeycomb segments with the in 3 shown form arranged alternately in an X direction. In addition, the positions of the honeycomb segments adjacent to the Y direction corresponded to those in the X direction. It is understood that in 17 The honeycomb segments shown are portions of the honeycomb segments that form the joined honeycomb segment body, but the remaining honeycomb segments, not shown, are arranged in a similar pattern.

Next, the circumference of the joined honeycomb segment body was ground and worked so that its outer shape was a round columnar shape having a diameter of 220 mm. After the grinding work, the processed surface of the joined body was coated with a circumferential coating material of the same composition as the binding material with a thickness of 1 mm and dried to cure at 700 ° C for 2 hours to form a peripheral cover layer, whereby the honeycomb structure of Example 1 was obtained ,

(Examples 2 to 9)

The procedures of Example 1 were repeated except that the curvature value of the concave side surface of the first honeycomb segment, the curvature value of the convex side surface of the second honeycomb segment and the thickness of the binder material were changed as shown in Table 1, whereby the honeycomb structures of Examples 2 to 9 were obtained ,

(Examples 10 to 13)

The procedures of Example 1 were repeated except that the curvature value of the concave side surface of the first honeycomb segment, the curvature value of the convex side surface of the second honeycomb segment, the thickness of the bonding material, and the arrangement of the honeycomb segments were changed as shown in Table 1, whereby the honeycomb structures of Examples 10 to 13 were obtained. In Examples 10 and 11, however, the number of honeycomb segments in the X direction was increased to six. 18 FIG. 10 is a schematic plan view showing the arrangement of the honeycomb segments in a joined honeycomb segment body of each of Examples 10 and 11. FIG. At the in 18 shown arrangement of the honeycomb segments, the positions of the adjacent honeycomb segments in the Y direction to move in 17 shown arrangement of the honeycomb segments by 1/2 the width of the honeycomb segment in the X direction. 19 FIG. 12 is a schematic plan view showing the arrangement of honeycomb segments in a joined honeycomb segment body of each of Examples 12 and 13. FIG. At the in 19 shown arrangement of the honeycomb segments, the positions of the adjacent honeycomb segments in the Y direction to move in 17 shown arrangement of the honeycomb segments to the width of a honeycomb segment in the X direction. It is understood that in 18 and 19 however, the honeycomb segments shown are portions of the honeycomb segments that show the joined honeycomb segment body, but the remaining honeycomb segments, not shown, are also arranged in a similar pattern.

(Example 14)

All four side faces of a honeycomb formed body obtained in the same manner as in Example 1 were sucked and deformed into a concave state by a method using a lid-like box as described above, and this honeycomb formed body was used as a shaped body for defines a first honeycomb segment. In addition, all four side faces of another honeycomb formed body obtained in the same manner were sucked and deformed into a convex state by the above method using the lid-like box, and this honeycomb formed body was defined as a shaped body for a second honeycomb segment. Thereafter, these shaped bodies were dried with microwaves and hot air, whereby dried bodies for the first honeycomb segments were obtained from the moldings for the first honeycomb segments, and dried bodies for the second honeycomb segments were obtained from the moldings for the second honeycomb segments.

Next, on these dried bodies, the forming of the sealing portions, calcining (degreasing) and firing were successively conducted in the same manner as in Example 1, whereby the first honeycomb segments were obtained from the dried bodies for the first honeycomb segments and the second honeycomb segments were obtained from the dried bodies were obtained for the second honeycomb segments. The first honeycomb segments obtained in this way had the in 4 That is, all the pair of side surfaces in which each pair of side surfaces faced each other were concave side surfaces bent in the concave state in the longitudinal direction of each first honeycomb segment. In addition, the second honeycomb segments had the in 5 Shape, that is, both of the pair of side surfaces in which each pair of side surfaces faced each other were convex side surfaces bent in the convex state in the longitudinal direction of each second honeycomb segment. In the first honeycomb segment, the cross section of its central portion in the longitudinal direction vertical to the longitudinal direction had a square shape of 45 mm × 45 mm, the thickness of the partition walls was 200 μm, the cell shape was square, and the cell density was 47 cells / cm ² . In the second honeycomb segment, both end surfaces (an inlet end surface and an outlet end surface) had a square shape of 45 mm x 45 mm, the thickness of the partition walls was 200 μm, the cell shape was square, and the cell density was 47 cells / cm ² . The curved shape of each concave side surface of the first honeycomb segment and the curved shape of each convex side surface of the second honeycomb segment had mutually complementary circular shapes, and the curvatures of these side surfaces were approximately the same. The circle centers of the circular concave side surface and convex side surface were in a plane vertical to the longitudinal direction of the honeycomb segment at a central position of the longitudinal direction of the honeycomb segment. In addition, both the curvature value of the concave side surface of the first honeycomb segment and the curvature value of the convex side surface of the second honeycomb segment were 1 mm. Further, the partition walls of these honeycomb segments were bent in the longitudinal direction of the honeycomb segment, and the cell shape changed in the longitudinal direction of the honeycomb segment. The first honeycomb segments and second honeycomb segments had a length of 215 mm and the partitions had a porosity of 50%. In addition, the thickness of each of the four side surfaces of each honeycomb segment was 0.5 mm.

Subsequently, a binding material obtained in the same manner as in Example 1 was applied to the side surfaces of the first honeycomb segment and the second honeycomb segment, whereby a thickness of about 2 mm was obtained. Next, the first honeycomb segments and the second honeycomb segments were alternately combined so that the concave side surfaces faced the convex side surfaces in two directions vertical to the longitudinal direction of the honeycomb segment. Thus, a honeycomb segment composite body was made comprising a total of 25 honeycomb segments attached as 5 segments x 5 segments. Further, the honeycomb segment composite body was dried at 120 ° C for 2 hours to obtain a joined honeycomb segment body, while the honeycomb segments constituting the honeycomb segment composite body were pressed together by, e.g. B. in a suitable external pressure was exerted on it. 20 Fig. 12 is a schematic plan view showing the arrangement of the honeycomb segments in this joined honeycomb segment body. As in 20 shown, the first honeycomb segments with the in 4 shown shape and the second honeycomb segments with the in 5 shown alternately arranged in the X direction and the Y direction. It is understood that in 20 The honeycomb segments shown are portions of the honeycomb segments that form the joined honeycomb segment body, but the remaining honeycomb segments, not shown, are arranged in a similar pattern.

Next, the circumference of the joined honeycomb segment body was ground and worked so that its outer shape was a round columnar shape having a diameter of 220 mm. After the grinding work, the processed surface of the joined body was coated with a circumferential coating material of the same composition as the binding material with a thickness of 1 mm and dried to cure at 700 ° C for 2 hours to form a peripheral cover layer, thereby obtaining the honeycomb structure of Example 14 , It is understood that in Example 14, the thickness of the bonding material is twice the curvature value of both the concave side surface and the convex side surface, so that the side surfaces of the adjacent honeycomb segments do not interfere with each other.

(Examples 15 to 22)

The procedures of Example 14 were repeated except that the curvature value of the concave side surface of the first honeycomb segment, the curvature value of the convex side surface of the second honeycomb segment and the thickness of the binder material were changed as shown in Table 1, whereby the honeycomb structures of Examples 15 to 22 were obtained , It is understood that in Examples 15 to 22, the thickness of the bonding material is more than twice the curvature value of both the concave side surface and the convex side surface, so that the side surfaces of the honeycomb segments do not interfere with each other.

(Examples 23 to 27)

The edge portion at which two adjacent concave side surfaces of the first honeycomb segments used in each of Examples 18 to 22 intersect, and the edge portion at which two adjacent convex side surfaces of the second honeycomb segments shown in each of Examples 18 to 22 were used, cut, were bevelled. Specifically, the above edge portion was C-chamfered so that the first honeycomb segments or the second honeycomb segments that were adjacent in a diagonal direction of each end surface of the honeycomb segment did not interfere with each other, even if the thickness of the binding material at the in 20 shown arrangement of the honeycomb segments was set to 1 mm. The C-chamfering was performed by grinding the above edge portion of the honeycomb segments with a grinding wheel. The procedures of Examples 18 to 22 were repeated except that the first honeycomb segments and second honeycomb segments chamfered as described above were used and the thickness of the bonding material was set to 1 mm, thereby obtaining the honeycomb structures of Examples 23 to 27. In addition, parts of the side surfaces and cells of the honeycomb segments were cut by the above chamfering, but the binding material was applied thereto, and therefore no disadvantage such as gas leakage was generated.

(Example 28)

In a honeycomb formed body obtained in the same manner as in Example 1, a pair of side surfaces in two pairs of side surfaces in which each pair of side surfaces face each other was formed by a method in which a lid-like box was used as above described, sucked and deformed in a concave state. In addition, the remaining pair of side surfaces of the same honeycomb formed body was sucked by the above-mentioned method in which the lid-like box was used, and deformed into a convex state. Consequently, the honeycomb formed body whose Side surfaces were deformed, defined as a shaped body for a mixed curvature honeycomb segment. Thereafter, this shaped body was dried with microwaves and hot air, thereby obtaining a dried body for the mixed-curvature honeycomb segment.

Next, on this dried body, forming the sealing portions, calcining (degreasing) and firing successively was conducted in the same manner as in Example 1, whereby the mixed-curvature honeycomb segment was obtained. The mixed-curvature honeycomb segment thus obtained had the in 6 That is, a pair of side surfaces in two pairs of side surfaces in which each pair of side surfaces face each other were concave side surfaces bent in the concave state in the longitudinal direction of the mixed-curvature honeycomb segment. In addition, the other pair of side surfaces were convex side surfaces bent in the convex state in the longitudinal direction of the mixed-curvature honeycomb segment. The distance between the facing concave side surfaces was 45 mm in the narrowest portion, that is, a central portion of the mixed-curvature honeycomb segment in the longitudinal direction of the honeycomb segment. The distance between the mutually facing convex side surfaces was 45 mm in the narrowest portion, ie, both end surfaces (an inlet end surface and an outlet end surface) of the mixed-curvature honeycomb segment. In addition, the mixed-curvature honeycomb segment had a length of 215 mm. The curved shape of each concave side surface of this mixed-curvature honeycomb segment and the curved shape of each convex side surface had mutually complementary circular shapes, and the curvatures of these side surfaces were approximately the same. The circle centers of the circular concave side surface and convex side surface were in a plane vertical to the longitudinal direction of the honeycomb segment at a central position of the longitudinal direction of the honeycomb segment. In addition, both the curvature value of the concave side surface of this mixed curvature honeycomb segment and the curvature value of the convex side surface were 1 mm. Further, the partitions of this mixed-curvature honeycomb segment were bent in the longitudinal direction of the mixed-curvature honeycomb segment, and the cell shape changed in the longitudinal direction of the honeycomb segment. The partition walls of the mixed-curvature honeycomb segment had a porosity of 50%, the thickness of the partition walls was 200 μm, and the cell density was 45 cells / cm ² in both end surfaces (the inlet end surface and the outlet end surface) and the middle of the segment in the longitudinal direction of the segment. In addition, the thickness of each of the four side surfaces of the mixed-curvature honeycomb segment was 0.5 mm.

Subsequently, a binder material obtained in the same manner as in Example 1 was applied to the side surfaces of the mixed-curvature honeycomb segment, whereby a thickness of about 1 mm was obtained. Next, the mixed-curvature honeycomb segments were combined with each other so that the concave side surfaces faced the convex side surfaces in two directions vertical to the longitudinal direction of the mixed-curvature honeycomb segment. Thus, a honeycomb segment composite body was made comprising a total of 25 mixed curvature honeycomb segments attached as 5 segments x 5 segments. Further, the honeycomb segment composite body was dried at 120 ° C for 2 hours to obtain a joined honeycomb segment body, while the mixed-curvature honeycomb segments constituting the honeycomb segment composite body were pressed together by, e.g. B. in a suitable external pressure was exerted on it. 21 Fig. 12 is a schematic plan view showing the arrangement of the honeycomb segments in this joined honeycomb segment body. As in 21 The alignment of the mixed-curvature honeycomb segments with that shown in FIG 6 alternately changed by 90 ° so that the honeycomb segments were arranged in the X direction and the Y direction. It is understood that in 21 However, the honeycomb segments shown are portions of the honeycomb segments forming the joined honeycomb segment body, but the remaining honeycomb segments, not shown, are arranged in a similar pattern.

Next, the circumference of the joined honeycomb segment body was ground and worked so that its outer shape was a round columnar shape having a diameter of 220 mm. After the grinding work, the processed surface of the joined body was coated with a circumferential coating material of the same composition as the binding material with a thickness of 1 mm and dried to cure at 700 ° C for 2 hours to form a peripheral cover layer, whereby the honeycomb structure of Example 28 was obtained ,

(Examples 29 to 36)

The procedures of Example 28 were repeated except that the curvature value of both the concave side surface and the convex side surface of the mixed-curvature honeycomb segment, the thickness of the binder material and the cell density were changed as shown in Table 2, thereby obtaining the honeycomb structures of Examples 29-36 were.

Comparative Example 1

A honeycomb formed body obtained in the same manner as in Example 1 was dried with microwaves and hot air, thereby obtaining a dried body for a honeycomb segment. Next, on this dried body, the forming of the sealing portions, calcination (degreasing) and firing were successively conducted in the same manner as in Example 1, whereby the honeycomb segment was obtained, the four side surfaces of which were all flat. In this honeycomb segment, both end surfaces (one inlet end surface and one outlet end surface) had a square shape of 45 mm × 45 mm and the honeycomb segment had a length of 215 mm. In addition, the partition walls of this honeycomb segment were parallel to the longitudinal direction of the honeycomb segment, and the cell shape was square and constant in the longitudinal direction of the honeycomb segment. The partition walls of the honeycomb segment had a porosity of 50%, the thickness of the partition walls was 200 μm, and the cell density was 47 cells / cm ² . In addition, the thickness of each of the four side surfaces of each honeycomb segment was 0.5 mm.

Subsequently, a binder material obtained in the same manner as in Example 1 was applied to the side surfaces of the honeycomb segments, whereby a thickness of about 1 mm was obtained. Next, the honeycomb segments were combined with each other so that the side surfaces of the honeycomb segments face each other. Thus, a honeycomb segment composite body was made comprising a total of 25 honeycomb segments attached as 5 segments x 5 segments. Further, the honeycomb segment composite body was dried at 120 ° C for 2 hours to obtain a joined honeycomb segment body, while the honeycomb segments constituting the honeycomb segment composite body were pressed together by, e.g. B. in a suitable external pressure was exerted on it.

Next, the circumference of the joined honeycomb segment body was ground and worked so that its outer shape was a round columnar shape having a diameter of 220 mm. After the grinding work, the processed surface of the joined body was coated with a peripheral coating material of the same composition as the binding material with a thickness of 1 mm and dried to cure at 700 ° C for 2 hours to form a peripheral cover layer, whereby the honeycomb structure of Comparative Example 1 was obtained ,

(Comparative Example 2)

A binding material obtained in the same manner as in Example 1 was applied to the side surfaces of the first honeycomb segments used in Example 11. Next, the first honeycomb segments were combined with each other so that the concave side surfaces of the honeycomb segments face each other. Thus, a honeycomb segment composite body was made comprising a total of only 25 first honeycomb segments attached as 5 segments x 5 segments. Further, the honeycomb segment composite body was dried at 120 ° C for 2 hours to obtain a joined honeycomb segment body, while the honeycomb segments constituting the honeycomb segment composite body were pressed together by, e.g. B. in a suitable external pressure was exerted on it. In addition, the thickness of the binding material was set at the thinnest portion of 1 mm.

Next, the circumference of the joined honeycomb segment body was ground and worked so that its outer shape was a round columnar shape having a diameter of 220 mm. After the grinding work, the processed surface of the joined body was coated with a peripheral coating material of the same composition as the binding material with a thickness of 1 mm and dried to cure at 700 ° C for 2 hours to form a peripheral cover layer, whereby the honeycomb structure of Comparative Example 2 was obtained ,

(Comparative Example 3)

A binding material obtained in the same manner as in Example 1 was applied to the side surfaces of the second honeycomb segments used in Example 11. Next, the second honeycomb segments were combined with each other so that the convex side surfaces of the honeycomb segments face each other. Thus, a honeycomb segment composite body was made comprising a total of only 25 second honeycomb segments attached as 5 segments x 5 segments. Further, the honeycomb segment composite body was dried at 120 ° C for 2 hours to obtain a joined honeycomb segment body, while the honeycomb segments constituting the honeycomb segment composite body were pressed together by, e.g. B. in a suitable external pressure was exerted on it. In addition, the thickness of the binding material was set at the thinnest portion of 1 mm.

Next, the circumference of the joined honeycomb segment body was ground and worked so that its outer shape was a round columnar shape having a diameter of 220 mm. After the grinding work, the processed surface of the joined body was coated with a peripheral coating material of the same composition as the binding material with a thickness of 1 mm and dried to cure at 700 ° C for 2 hours to form a peripheral cover layer, whereby the honeycomb structure of Comparative Example 3 was obtained ,

(Comparative Example 4)

A binding material obtained in the same manner as in Example 1 was applied to the concave side surfaces of the first honeycomb segments used in Example 17. Next, the first honeycomb segments were combined with each other so that the concave side surfaces of the honeycomb segments face each other. Thus, a honeycomb segment composite body was made comprising a total of only 25 first honeycomb segments attached as 5 segments x 5 segments. Further, the honeycomb segment composite body was dried at 120 ° C for 2 hours to obtain a joined honeycomb segment body, while the honeycomb segments constituting the honeycomb segment composite body were pressed together by, e.g. B. in a suitable external pressure was exerted on it. In addition, the thickness of the binding material was set at the thinnest portion of 1 mm.

Next, the circumference of the joined honeycomb segment body was ground and worked so that its outer shape was a round columnar shape having a diameter of 220 mm. After the grinding work, the processed surface of the joined body was coated with a circumferential coating material of the same composition as the binding material with a thickness of 1 mm and dried to cure at 700 ° C for 2 hours to form a peripheral cover layer, whereby the honeycomb structure of Comparative Example 4 was obtained ,

(Comparative Example 5)

A binding material obtained in the same manner as in Example 1 was applied to the concave side surfaces of the first honeycomb segments used in Example 19. Next, the first honeycomb segments were combined with each other so that the concave side surfaces of the honeycomb segments face each other. Thus, a honeycomb segment composite body was made comprising a total of only 25 first honeycomb segments attached as 5 segments x 5 segments. Further, the honeycomb segment composite body was dried at 120 ° C for 2 hours to obtain a joined honeycomb segment body, while the honeycomb segments constituting the honeycomb segment composite body were pressed together by, e.g. B. in a suitable external pressure was exerted on it. In addition, the thickness of the binding material was set at the thinnest portion of 1 mm.

Next, the circumference of the joined honeycomb segment body was ground and worked so that its outer shape was a round columnar shape having a diameter of 220 mm. After the grinding work, the processed surface of the joined body was coated with a peripheral coating material of the same composition as the binding material with a thickness of 1 mm and dried to cure at 700 ° C for 2 hours to form a peripheral cover layer, whereby the honeycomb structure of Comparative Example 5 was obtained ,

(Comparative Example 6)

A binding material obtained in the same manner as in Example 1 was applied to the convex side surfaces of the second honeycomb segments used in Example 14. Next, the second honeycomb segments were combined with each other so that the convex side surfaces of the honeycomb segments face each other. Thus, a honeycomb segment composite body was made comprising a total of only 25 second honeycomb segments attached as 5 segments x 5 segments. Further, the honeycomb segment composite body was dried at 120 ° C for 2 hours to obtain a joined honeycomb segment body, while the honeycomb segments constituting the honeycomb segment composite body were pressed together by, e.g. B. in a suitable external pressure was exerted on it. In addition, the thickness of the binding material was set at the thinnest portion of 1 mm.

Next, the circumference of the joined honeycomb segment body was ground and worked so that its outer shape was a round columnar shape having a diameter of 220 mm. After grinding, the machined surface of the joined body was replaced with a The peripheral coating material of the same composition as that of the binding material was coated with a thickness of 1 mm and dried to cure at 700 ° C for 2 hours to form a peripheral cover layer, thereby obtaining the honeycomb structure of Comparative Example 6.

(Comparative Example 7)

A binding material obtained in the same manner as in Example 1 was applied to the convex side surfaces of the second honeycomb segments used in Example 19. Next, the second honeycomb segments were combined with each other so that the convex side surfaces of the honeycomb segments face each other. Thus, a honeycomb segment composite body was made comprising a total of only 25 second honeycomb segments attached as 5 segments x 5 segments. Further, the honeycomb segment composite body was dried at 120 ° C for 2 hours to obtain a joined honeycomb segment body, while the honeycomb segments constituting the honeycomb segment composite body were pressed together by, e.g. B. in a suitable external pressure was exerted on it. In addition, the thickness of the binding material was set at the thinnest portion of 1 mm.

Next, the circumference of the joined honeycomb segment body was ground and worked so that its outer shape was a round columnar shape having a diameter of 220 mm. After the grinding work, the processed surface of the joined body was coated with a circumferential coating material of the same composition as the binding material with a thickness of 1 mm and dried to cure at 700 ° C for 2 hours to form a peripheral cover layer, whereby the honeycomb structure of Comparative Example 7 was obtained , [Table 1] first honeycomb segment second honeycomb segment Arrangement of the honeycomb segments Thickness of the binding material (mm) shape Curvature value of the concave side surface (mm) Curvature value of the convex side surface (mm) shape Curvature value of the concave side surface (mm) Curvature value of the convex side surface (mm) example 1 Fig. 2 1.0 - Fig. 3 - 1.0 Fig. 17 1.0 Example 2 Fig. 2 0.2 - Fig. 3 - 0.2 Fig. 17 0.5 Example 3 Fig. 2 0.3 - Fig. 3 - 0.3 Fig. 17 0.5 Example 4 Fig. 2 0.5 - Fig. 3 - 0.5 Fig. 17 0.5 Example 5 Fig. 2 1.5 - Fig. 3 - 1.5 Fig. 17 1.0 Example 6 Fig. 2 2.0 - Fig. 3 - 2.0 Fig. 17 1.0 Example 7 Fig. 2 2.5 - Fig. 3 - 2.5 Fig. 17 1.0 Example 8 Fig. 2 3.0 - Fig. 3 - 3.0 Fig. 17 1.0 Example 9 Fig. 2 3.5 - Fig. 3 - 3.5 Fig. 17 1.0 Example 10 Fig. 2 0.2 - Fig. 3 - 0.2 Fig. 18 0.5 Example 11 Fig. 2 2.0 - Fig. 3 - 2.0 Fig. 18 1.0 Example 12 Fig. 2 0.5 - Fig. 3 - 0.5 Fig. 19 0.5 Example 13 Fig. 2 3.5 - Fig. 3 - 3.5 Fig. 19 1.0 Example 14 Fig. 4 1.0 - Fig. 5 - 1.0 Fig. 20 2.0 Example 15 Fig. 4 0.2 - Fig. 5 - 0.2 Fig. 20 0.5 Example 16 Fig. 4 0.3 - Fig. 5 - 0.3 Fig. 20 0.7 Example 17 Fig. 4 0.5 - Fig. 5 - 0.5 Fig. 20 1.2 Example 18 Fig. 4 1.5 - Fig. 5 - 1.5 Fig. 20 3.2 Example 19 Fig. 4 2.0 - Fig. 5 - 2.0 Fig. 20 4.2 Example 20 Fig. 4 2.5 - Fig. 5 - 2.5 Fig. 20 5.1 Example 21 Fig. 4 3.0 - Fig. 5 - 3.0 Fig. 20 6.1 Example 22 Fig. 4 3.5 - Fig. 5 - 3.5 Fig. 20 7.2 Example 23 Fig. 4 1.5 - Fig. 5 - 1.5 Fig. 20 1.0 Example 24 Fig. 4 2.0 - Fig. 5 - 2.0 Fig. 20 1.0 Example 25 Fig. 4 2.5 - Fig. 5 - 2.5 Fig. 20 1.0 Example 26 Fig. 4 3.0 - Fig. 5 - 3.0 Fig. 20 1.0 Example 27 Fig. 4 3.5 - Fig. 5 - 3.5 Fig. 20 1.0 [Table 2] Mixed curvature honeycomb segment Arrangement of the honeycomb segments Thickness of the binding material (mm) Cell density in both end faces of the mixed-curvature honeycomb segment and its longitudinal center (cells / cm ² ) shape Curvature value of the concave side surface (mm) Curvature value of the convex side surface (mm) Example 28 Fig. 6 1.0 1.0 Fig. 21 1.0 45 Example 29 Fig. 6 0.2 0.2 Fig. 21 0.5 46.6 Example 30 Fig. 6 0.3 0.3 Fig. 21 0.5 46.4 Example 31 Fig. 6 0.5 0.5 Fig. 21 0.5 46 Example 32 Fig. 6 1.5 1.5 Fig. 21 1.0 44.1 Example 33 Fig. 6 2.0 2.0 Fig. 21 1.0 43.2 Example 34 Fig. 6 2.5 2.5 Fig. 21 1.0 42.3 Example 35 Fig. 6 3.0 3.0 Fig. 21 1.0 41.5 Example 36 Fig. 6 3.5 3.5 Fig. 21 1.0 40.7 [Table 3] honeycomb segment Arrangement of the honeycomb segments Thickness of the binding material (mm) shape Curvature value of the concave side surface (mm) Curvature value of the convex side surface (mm) Comparative Example 1 - 0 0 - 1.0 Comparative Example 2 Fig. 2 2.0 - - 1.0 (thinnest section) Comparative Example 3 Fig. 3 - 2.0 - 1.0 (thinnest section) Comparative Example 4 Fig. 4 0.5 - - 1.0 (thinnest section) Comparative Example 5 Fig. 4 2.0 - - 1.0 (thinnest section) Comparative Example 6 Fig. 5 - 1.0 - 1.0 (thinnest section) Comparative Example 7 Fig. 5 - 2.0 - 1.0 (thinnest section)

(Rating)

As for the honeycomb structures of Examples 1 to 36 and Comparative Examples 1 to 7, a heat vibration test for evaluating vibration resistance was carried out by the following method. Further, as for the honeycomb structures of Examples 1 to 36 and Comparative Example 1, an electric furnace thermal shock resistance test for evaluation of thermal shock resistance, evaluation of PM recovery performance and measurement of pressure drop for evaluation of influence on engine performance or the like were carried out by the following methods carried out.

[Heat vibration test]

A:

Nach dem Wärmevibrationstest war, wenn die Wabenstruktur in dem Ummantelungselement ummantelt ist, bei keinem der Wabensegmente eine Bewegung (Verschiebung) von 0,1 mm oder mehr zu erkennen, und es gab keinerlei sich bewegende Wabensegmente, selbst wenn jedes Wabensegment mit einer Kraft von 5 kg in der Längsrichtung der Wabenstruktur gedrückt wurde.

B:

Nach dem Wärmevibrationstest war, wenn die Wabenstruktur in dem Ummantelungselement ummantelt ist, bei keinem der Wabensegmente eine Bewegung (Verschiebung) von 0,1 mm oder mehr zu erkennen, wenn jedoch jedes Wabensegment mit einer Kraft von 5 kg in der Längsrichtung der Wabenstruktur gedrückt wurde, bewegte sich das Wabensegment.

C:

Nach dem Wärmevibrationstest war, wenn die Wabenstruktur in dem Ummantelungselement ummantelt ist, bei zumindest einem Wabensegment eine Bewegung (Verschiebung) von 0,1 mm oder mehr und weniger als 0,5 mm erkennbar.

D:

Nach dem Wärmevibrationstest war, wenn die Wabenstruktur in dem Ummantelungselement ummantelt ist, bei zumindest einem Wabensegment eine Bewegung (Verschiebung) von 0,5 mm oder mehr erkennbar.

A non-thermally expandable ceramic mat was wrapped around the periphery of each honeycomb structure, and the honeycomb structure was pressed into a stainless steel sheath (SUS430) and encased in this sheath element. The honeycomb structure sheathed in the sheath member in this manner was placed on a device for the heat vibration test so that the longitudinal direction of the honeycomb structure was an upward-downward direction, and the heat vibration test was performed. As test conditions, the gas temperature in an end face of the honeycomb structure on an upstream side was set to 950 ° C, the vibration direction was set in the up-down direction, the vibration acceleration was set to 40 G, and the vibration frequency was set to 200 Hz, and vibration was continuously applied to the honeycomb structure for 200 hours while a propane combustion gas flowed into the honeycomb structure at a flow rate of 12 Nm ³ / minute. The evaluation criteria for this test are as follows.

A:

After the heat vibration test, when the honeycomb structure was encased in the sheath member, no movement (displacement) of 0.1 mm or more was seen on any of the honeycomb segments, and there were no moving honeycomb segments even if each honeycomb segment had a force of 5 kg was pressed in the longitudinal direction of the honeycomb structure.

B:

After the heat vibration test, when the honeycomb structure was sheathed in the sheath member, no movement (displacement) of 0.1 mm or more was seen on any of the honeycomb segments, but each honeycomb segment was pushed with a force of 5 kg in the longitudinal direction of the honeycomb structure , the honeycomb segment moved.

C:

After the heat vibration test, when the honeycomb structure is sheathed in the sheath member, at least one honeycomb segment has a movement (displacement) of 0.1 mm or more and less than 0.5 mm.

D:

After the heat vibration test, when the honeycomb structure is sheathed in the sheath member, at least one honeycomb segment could detect a movement (displacement) of 0.5 mm or more.

It is understood that in the evaluation of this heat vibration test in the "A" honeycomb structure, the movement of the honeycomb segments due to vibration or exhaust pressure can be inhibited exceptionally effectively, and the honeycomb structure has no problem in its usual use as a filter. The "B" weighted honeycomb structure is slightly inferior to the "A" rated honeycomb but does not pose any problems in its usual use as a filter. The honeycomb structure rated "C" is of limited use as a filter. On the other hand, in the honeycomb structure rated "D", the movement of the honeycomb segment due to vibration or exhaust pressure can not be sufficiently inhibited, and there is a high possibility that problems arise in the conventional use of the honeycomb structure as a filter.

Table 4 shows the results of this heat vibration test. That is, the honeycomb structures of Examples 1 to 36 were rated "A" to "C", whereas each of the honeycomb structures of Comparative Examples 1 to 7 was rated "D".

[Electric furnace thermal shock resistance test]

An evaluation of the thermal shock resistance by an electric furnace thermal shock resistance test was made on the basis of a method set forth in U.S. Pat JASO standards M505-87 as automotive standards, published by the Society of Automotive Engineers of Japan , carried out. Specifically, the honeycomb structure was placed at room temperature in an electric furnace kept at a temperature higher than room temperature by a predetermined temperature and kept for 20 minutes, and the honeycomb structure was taken out on a refractory stone in the natural state for 15 minutes or more was allowed to stand and cooled until the temperature reached room temperature, and then it was checked whether or not damage such as cracks had been generated. This process was repeated until damage such as cracks in the honeycomb structure was generated. In addition, the temperature in the electric furnace was raised by 25 ° C each time the above operation was repeated. The temperature in the electric furnace was defined as a safe temperature of the honeycomb structure in the process preceding the process of confirming that damage such as cracks were generated in the honeycomb structure. In a case where this safe temperature is obviously high as compared with the honeycomb structure of Comparative Example 1 having a structure equivalent to the honeycomb structure heretofore used in an ordinary PM trap filter, there is a possibility that the damage due to insufficient Thermal shock resistance can be generated when the honeycomb structure is installed in an exhaust system of an engine. The test was conducted with respect to three samples in both Comparative Example 1 and Examples 1 to 36.

Table 4 shows the results of this electric furnace thermal shock resistance test. That is, no significant differences were seen between the safe temperature of the honeycomb structure of Comparative Example 1 and the safe temperature of the honeycomb structure of Examples 1 to 36.

[PM trapping performance]

The honeycomb structure was attached to the exhaust system of a vehicle on which a four-cylinder diesel engine with a displacement of 2 liters was mounted. Further, when this vehicle was driving in a New European Driving Cycle (NEDC) mode, the number of PM particles (particles / km) to be discharged was measured on the exhaust side of the honeycomb structure. In a case where this number of PM particles to be ejected is obviously high as compared with the honeycomb structure of Comparative Example 1 having a structure equivalent to the honeycomb structure hitherto used in an ordinary PM trap filter, there is a possibility that there is a problem when used as a PM trap filter. The evaluation was made with respect to three samples in both of Comparative Example 1 and Examples 1 to 36.

Table 4 shows the evaluation results of this PM collecting performance. That is, no significant differences were seen between the number of PM particles to be discharged from the honeycomb structure of Comparative Example 1 and the number of PM particles to be discharged from the honeycomb structure of Examples 1 to 36.

[Pressure drop]

A:

Wenn der Druckabfall der Wabenstruktur von Vergleichsbeispiel 1 als eine Bezugsgröße 100% beträgt, beträgt der Druckabfall der Wabenstruktur eines Bewertungsgegenstandes 102% oder weniger.

B:

Wenn der Druckabfall der Wabenstruktur von Vergleichsbeispiel 1 als die Bezugsgröße 100% beträgt, beträgt der Druckabfall der Wabenstruktur des Bewertungsgegenstandes mehr als 102% und 105% oder weniger.

C:

Wenn der Druckabfall der Wabenstruktur von Vergleichsbeispiel 1 als die Bezugsgröße 100% beträgt, beträgt der Druckabfall der Wabenstruktur des Bewertungsgegenstandes mehr als 105% und 110% oder weniger.

D:

Wenn der Druckabfall der Wabenstruktur von Vergleichsbeispiel 1 als die Bezugsgröße 100% beträgt, beträgt der Druckabfall der Wabenstruktur des Bewertungsgegenstandes mehr als 110%.

When air at room temperature (25 ° C.) was passed through the honeycomb structure at a flow rate of 12 m ³ / minute, the pressures on the inlet side (upstream side) and outlet side (downstream side) of the honeycomb structure were measured, and the difference between the pressure was calculated, whereby the pressure drop was obtained. In a case where this pressure loss is apparently high as compared with the honeycomb structure of Comparative Example 1 having a structure equivalent to the honeycomb structure hitherto used in an ordinary PM trap filter, there is a possibility that the problem of reducing the Engine power or the like occurs when the honeycomb structure is installed in the exhaust system of the engine. The evaluation criteria for this test are as follows.

A:

When the pressure drop of the honeycomb structure of Comparative Example 1 as a reference is 100%, the pressure drop of the honeycomb structure of an evaluation article is 102% or less.

B:

When the pressure drop of the honeycomb structure of Comparative Example 1 as the reference is 100%, the pressure drop of the honeycomb structure of the evaluation subject is more than 102% and 105% or less.

C:

When the pressure drop of the honeycomb structure of Comparative Example 1 as the reference is 100%, the pressure drop of the honeycomb structure of the evaluation subject is more than 105% and 110% or less.

D:

When the pressure drop of the honeycomb structure of Comparative Example 1 as the reference is 100%, the pressure drop of the honeycomb structure of the evaluation subject is more than 110%.

It will be understood that when assessing the pressure drop in the case of the rating "A", the influence on the engine output can be ignored, and it can be considered that the honeycomb structure is particularly suitable. In the case of the rating of "B", the influence on the engine output is at a level where no practical problems occur, and it can be considered that the honeycomb structure is suitable. In the case of the rating of "C", the influence on the engine output is at a level where no large practical problem occurs, and it can be considered that the honeycomb structure is suitable. In the case of the rating of "D", the engine performance is affected and it can be considered that the honeycomb structure is defective.

Table 4 shows the evaluation results of the pressure drop. That is, the honeycomb structures of Examples 1 to 36 were rated "A" to "C", and no honeycomb structures were rated "D".

[General Rating]

A:

Selbst bei schwierigen Nutzungsbedingungen gibt es keinerlei Probleme in Bezug auf die Leistung, und die Wabenstruktur ist gut geeignet.

B:

Die Wabenstruktur weist keinerlei praktische Probleme auf und hat eine geeignete Leistung.

C:

Es gab keine großen praktischen Probleme, und bei der üblichen Verwendung treten keinerlei Probleme auf.

D:

Es gibt Probleme in Bezug auf die Leistung.

From the above results on the honeycomb structures of Examples 1 to 36 and Comparative Examples 1 to 7, general evaluations were made. The criteria of the general evaluation are as follows.

A:

Even in difficult conditions of use, there are no performance issues and the honeycomb structure is well suited.

B:

The honeycomb structure has no practical problems and has a suitable performance.

C:

There were no big practical problems, and there are no problems with the usual use.

D:

There are problems in terms of performance.

Table 4 shows the results of the general evaluation. That is, the honeycomb structures of Examples 1 to 36 were rated "A" to "C", and all honeycomb structures showed performances in which there were no practical problems. In addition, in the honeycomb structures of Examples 18 and 19, the thickness of the bonding material was increased so that the edge portion of the honeycomb segment did not interfere, the edge portion of the honeycomb segment was therefore C-chamfered to eliminate the disturbance of the edge portion of the honeycomb segment, and the pressure drop was easy but had a level at which no practical problems occurred, as compared with the honeycomb structures of Examples 23 and 24, in which the thickness of each bonding portion was 1 mm. In the honeycomb structure of Comparative Example 1, in which the honeycomb segments were arranged, each having four side surfaces, which were all planar, and the honeycomb structures of Comparative Examples 2 to 7, in which the honeycomb segments were arranged such that the concave side surfaces or the convex side surfaces No good results were obtained in the heat vibration test, therefore, it was considered that the use of these honeycomb structures was difficult, and the general rating was "D". [Table 4] Heat vibration test Electric furnace thermal shock resistance test PM trapping performance pressure drop General rating example 1 A no significant difference to Comparative Example 1 no significant difference to Comparative Example 1 A A Example 2 C no significant difference to Comparative Example 1 no significant difference to Comparative Example 1 A C Example 3 B no significant difference to Comparative Example 1 no significant difference to Comparative Example 1 A B Example 4 A no significant difference to Comparative Example 1 no significant difference to Comparative Example 1 A A Example 5 A no significant difference to Comparative Example 1 no significant difference to Comparative Example 1 A A Example 6 A no significant difference to Comparative Example 1 no significant difference to Comparative Example 1 A A Example 7 A no significant difference to Comparative Example 1 no significant difference to Comparative Example 1 B B Example 8 A no significant difference to Comparative Example 1 no significant difference to Comparative Example 1 B B Example 9 A no significant difference to Comparative Example 1 no significant difference to Comparative Example 1 C C Example 10 C no significant difference to Comparative Example 1 no significant difference to Comparative Example 1 A C Example 11 A no significant difference to Comparative Example 1 no significant difference to Comparative Example 1 A A Example 12 A no significant difference to Comparative Example 1 no significant difference to Comparative Example 1 A A Example 13 A no significant difference to Comparative Example 1 no significant difference to Comparative Example 1 C C Example 14 A no significant difference to Comparative Example 1 no significant difference to Comparative Example 1 A A Example 15 C no significant difference to Comparative Example 1 no significant difference to Comparative Example 1 A C Example 16 B no significant difference to Comparative Example 1 no significant difference to Comparative Example 1 A B Example 17 A no significant difference to Comparative Example 1 no significant difference to Comparative Example 1 A A Example 18 A no significant difference to Comparative Example 1 no significant difference to Comparative Example 1 B B Example 19 A no significant difference to Comparative Example 1 no significant difference to Comparative Example 1 B B Example 20 A no significant difference to Comparative Example 1 no significant difference to Comparative Example 1 B B Example 21 A no significant difference to Comparative Example 1 no significant difference to Comparative Example 1 B B Example 22 A no significant difference to Comparative Example 1 no significant difference to Comparative Example 1 C C Example 23 A no significant difference to Comparative Example 1 no significant difference to Comparative Example 1 A A Example 24 A no significant difference to Comparative Example 1 no significant difference to Comparative Example 1 A A Example 25 A no significant difference to Comparative Example 1 no significant difference to Comparative Example 1 B B Example 26 A no significant difference to Comparative Example 1 no significant difference to Comparative Example 1 B B Example 27 A no significant difference to Comparative Example 1 no significant difference to Comparative Example 1 C C Example 28 A no significant difference to Comparative Example 1 no significant difference to Comparative Example 1 A A Example 29 C no significant difference to Comparative Example 1 no significant difference to Comparative Example 1 A C Example 30 B no significant difference to Comparative Example 1 no significant difference to Comparative Example 1 A B Example 31 A no significant difference to Comparative Example 1 no significant difference to Comparative Example 1 A A Example 32 A no significant difference to Comparative Example 1 no significant difference to Comparative Example 1 A A Example 33 A no significant difference to Comparative Example 1 no significant difference to Comparative Example 1 A A Example 34 A no significant difference to Comparative Example 1 no significant difference to Comparative Example 1 B B Example 35 A no significant difference to Comparative Example 1 no significant difference to Comparative Example 1 B B Example 36 A no significant difference to Comparative Example 1 no significant difference to Comparative Example 1 C C Comparative Example 1 D - - - D Comparative Example 2 D not rated not rated not rated D Comparative Example 3 D not rated not rated not rated D Comparative Example 4 D not rated not rated not rated D Comparative Example 5 D not rated not rated not rated D Comparative Example 6 D not rated not rated not rated D Comparative Example 7 D not rated not rated not rated D

The present invention can be suitably used in a filter for collecting particulates contained in the exhaust gas of a diesel engine or a gasoline engine, a catalyst carrier loaded with a catalyst for purifying the exhaust gas, or the like.

Description of the reference numerals

• 1 : Honeycomb structure, 2 : Honeycomb segment, 2a : first honeycomb segment, 2 B : second honeycomb segment, 2c Photos: Mixed Curve Honeycomb Segment, 3 : Inlet end surface, 4 : Outlet end face, 5a to 5d : Side surface, 6 : concave side surface, 7 : convex side surface, 10 : Cell, 10a : predetermined cell, 10b : remaining cell, 11 : Partition wall, 12 : Binding material, 13 : Circumferential cover layer, 14 Image: Locking section, 15 Photos: flat plate, 16 : Honeycomb Moldings, 17 : Side surface, 18 Image: Plate, 19 : convex surface and 20 : Roller.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• JP 2015-052496 [0001]
• WO 2005/047210 [0011]
• WO 2006/126507 [0011]
• WO 2008/096502 [0011]

Cited non-patent literature

• JASO Standards M505-87 as Automotive Standards, published by the Society of Automotive Engineers of Japan [0115]

Claims (12)

A honeycomb structure comprising a plurality of honeycomb segments each having porous partition walls defining a plurality of cells extending from an inlet end surface which becomes an inlet side for a fluid to an outlet end surface which becomes an outlet side for the fluid, and an outer peripheral surface which surrounds the inlet end surface with the outlet end face connecting, wherein the plurality of honeycomb segments are integrally connected via a binding material, wherein the plurality of honeycomb segments comprises a plurality of first honeycomb segments and a plurality of second honeycomb segments, in the first honeycomb segment, the inlet end face and the outlet end face are quadrangular and at least a pair of side faces in two pairs of side faces where each pair of side faces of the outer peripheral face face each other are concave side faces which are in a concave state in a longitudinal direction of the first honeycomb segment are bent, in the second honeycomb segment, the inlet end surface and the outlet end surface are quadrangular, and at least a pair of side surfaces in two pairs of side surfaces where each pair of side surfaces of the outer peripheral surface face each other are convex side surfaces that are in a convex state in a longitudinal direction of the second honeycomb segment are bent, the first honeycomb segments and the second honeycomb segments are alternately arranged such that the concave side surfaces face the convex side surfaces in at least one direction vertical to the longitudinal direction of the honeycomb segment, and the shape of the cells of at least parts of the plurality of cells in a cross section of the honeycomb segment that is vertical to the longitudinal direction of the honeycomb segment changes in the longitudinal direction of the honeycomb segment. The honeycomb structure according to claim 1, wherein all two pairs of the side surfaces of the first honeycomb segments are the concave side surfaces bent into the concave state, all two pairs of the side surfaces of the second honeycomb segments are the convex side surfaces bent into the convex state, and first honeycomb segments and the second honeycomb segments are alternately arranged, so that the concave side surfaces facing the convex side surfaces in two directions vertical to the longitudinal direction of the honeycomb segment. A honeycomb structure comprising a plurality of honeycomb segments each having porous partition walls defining a plurality of cells extending from an inlet end surface which becomes an inlet side for a fluid to an outlet end surface which becomes an outlet side for the fluid, and an outer peripheral surface which surrounds the inlet end surface with the outlet end face connecting, wherein the plurality of honeycomb segments are integrally connected via a binding material, wherein the plurality of honeycomb segments comprise a plurality of mixed curvature honeycomb segments, wherein, in each of them, the inlet end surface and the outlet end surface are quadrangular, a pair of side surfaces in two pairs of side surfaces in which each pair of side surfaces of the outer peripheral surface face each other are concave side surfaces bent in a concave state in a longitudinal direction of the honeycomb segment and the other pair of side surfaces are convex side surfaces bent in a convex state in the longitudinal direction of the honeycomb segment, the plurality of mixed-curvature honeycomb segments are arranged such that the concave side surfaces face the convex side surfaces in two directions vertical to the longitudinal direction of the honeycomb segment, and the shape of the cells of at least parts of the plurality of cells in a cross section of the honeycomb segment that is vertical to the longitudinal direction of the honeycomb segment changes in the longitudinal direction of the honeycomb segment. The honeycomb structure according to any one of claims 1 to 3, wherein the curvature value of both the concave side surface and the convex side surface is 0.2 to 3.5 mm. The honeycomb structure according to any one of claims 1 to 4, wherein the honeycomb segments have closure portions that close open ends of the predetermined cells on the side of the inlet end surface and open ends of the remaining cells on the side of the outlet end surface. A honeycomb structure according to any one of claims 1 to 5, wherein a catalyst component is loaded on the partition walls. The honeycomb structure according to any one of claims 1 to 6, wherein the plurality of honeycomb segments are integrally bonded via the bonding material and then subjected to peripheral grinding processing to form a circumferential cover layer on the machined surface. The honeycomb structure according to claim 2, wherein at least a part of an edge portion where two adjacent concave side surfaces of the first honeycomb segments intersect and at least a part of an edge portion where two adjacent convex side surfaces of the second honeycomb segments intersect are chamfered. A honeycomb structure according to any one of claims 1 to 8, wherein the thickness of the bonding material is uniform between the side surfaces of the adjacent honeycomb segments. The honeycomb structure according to any one of claims 1 to 9, wherein the thickness of the bonding material is twice or more of the curvature value of both the concave side surface and the convex side surface. The honeycomb structure according to any one of claims 1 to 10, wherein the cross section of the honeycomb segment has a size vertical to the cell passing direction so as to include a circle having a diameter of 30 mm. The honeycomb structure according to any one of claims 1 to 11, wherein the cross section of the honeycomb structure vertical to the cell passing direction has a size such that it may include a circle having a diameter of 200 mm.

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