JP7215943B2 - Honeycomb structure manufacturing method - Google Patents

Description

The present invention relates to a method for manufacturing a honeycomb structure. More specifically, it relates to a method for manufacturing a honeycomb structure capable of improving the bonding strength of a bonding layer that bonds a plurality of honeycomb segments.

In recent years, society as a whole has become more aware of environmental issues, and in the field of technology that burns fuel to generate power, there are various technologies that remove harmful components such as nitrogen oxides from the exhaust gas generated when fuel is burned. is being developed. For example, various techniques have been developed to remove harmful components such as nitrogen oxides from exhaust gases emitted from automobile engines. When removing such harmful components from the exhaust gas, it is common to use a catalyst to chemically react the harmful components to change them into other relatively harmless components. A honeycomb structure is used as a catalyst carrier for carrying a catalyst for exhaust gas purification.

Exhaust gas emitted by combustion of an internal combustion engine contains particulate matter such as soot together with toxic gases such as nitrogen oxides. Hereinafter, particulate matter may be referred to as "PM". PM is an abbreviation for "Particulate Matter". For example, regulations regarding the removal of PM emitted from gasoline engines are becoming stricter worldwide, and honeycomb structures are used as filters for removing PM.

Conventionally, as such a honeycomb structure, a honeycomb structure in which a plurality of honeycomb segments are joined by a joining layer has been disclosed (see, for example, Patent Document 1). Hereinafter, such a honeycomb structure may be referred to as a "segment structure honeycomb structure". A honeycomb structure having a segment structure has a structure in which one honeycomb structure is divided by a plurality of honeycomb segments, so that thermal stress generated in the honeycomb structure can be dispersed. Moreover, in a honeycomb structure having a segment structure, a bonding layer that bonds a plurality of honeycomb segments may serve as a cushioning member that relaxes thermal stress.

A honeycomb structure having a segment structure is manufactured, for example, by the following method. First, a plurality of honeycomb segments are produced. Next, a paste-like bonding material is applied to the sides of the manufactured honeycomb segment. Next, the honeycomb segments to which the bonding material has been applied are combined so that the side faces face each other to produce a honeycomb segment assembly. Next, the honeycomb segment assembly is dried, and the side faces of the plurality of honeycomb segments are joined with a joining material to produce a joined body of honeycomb segments. Next, if necessary, the peripheral portion of the bonded body of honeycomb segments is processed into a desired shape to manufacture a honeycomb structure. Hereinafter, in the present specification, the term “joining material” means a paste-like fluid substance before drying, and the term “joining layer” means a solid substance after the drying of the jointing material. . The bonding layer after drying the bonding material is usually a porous structure.

JP 2015-187044 A

In the method for manufacturing a honeycomb structure having a segment structure, examples of the bonding material for bonding the side surfaces of the honeycomb segments include inorganic materials such as inorganic fibers, colloidal silica, clay, and SiC particles, organic binders, foamed resins, and dispersions. Paste-like bonding materials prepared by adding additives such as adhesive agents are used. As a method for drying the assembly of honeycomb segments, for example, there is a method of drying with hot air using a continuous drying furnace, and the maximum temperature during drying is, for example, 120°C.

In drying the honeycomb segment assembly described above, it takes a longer time to dry the bonding material inside the assembly than in the outer peripheral portion of the assembly. A conventional honeycomb structure having a segment structure has a problem that the bonding strength of the bonding layer inside the assembly is lower than that of the bonding layer on the outer periphery of the assembly with respect to the bonding strength for bonding the honeycomb segments. there were. In particular, this tendency tends to become more pronounced as the size of the honeycomb segment assembly increases. As described above, since it takes a long time to dry the bonding material inside the assembly, the bonding layer after drying tends to have a rough structure due to the connection of the pores of the porous body. It is presumed that the bonding strength of the bonding layer inside the three-dimensional body is lowered. The time required for drying can be shortened by increasing the maximum temperature during drying. However, rapid drying shrinkage occurs from the surface of the bonding material, and the honeycomb segment assembly tends to crack, resulting in a poor yield. Therefore, when drying the honeycomb segment assembly, it is necessary to heat slowly so as to reduce the drying difference between the inside and outside of the honeycomb segment assembly.

The present invention has been made in view of such problems of the prior art. According to the present invention, there is provided a method for manufacturing a honeycomb structure that can improve the bonding strength of a bonding layer in a honeycomb structure having a segment structure.

According to the present invention, the following method for manufacturing a honeycomb structure is provided.

[1] a honeycomb segment manufacturing step of manufacturing a plurality of prismatic honeycomb segments having porous partition walls arranged to surround a plurality of cells and segment outer walls arranged to surround the partition walls;
A bonding paste is applied to the side surfaces of the honeycomb segments, and a plurality of the honeycomb segments are combined in a lattice with the bonding paste interposed between the side surfaces of the plurality of honeycomb segments. an assembly manufacturing step of manufacturing an assembly of honeycomb segments;
a bonded body manufacturing step of drying the assembly of the honeycomb segments and bonding the side faces of a plurality of the honeycomb segments together with the bonding paste to manufacture a bonded body of the honeycomb segments;
In the assembly manufacturing step, a fibrous or net-like heat transfer auxiliary member is provided on a side portion of at least one of the honeycomb segments, and a plurality of the honeycomb segments including the honeycomb segment provided with the heat transfer auxiliary member are arranged. A method for manufacturing a honeycomb structure, comprising combining honeycomb segments to manufacture the assembly of the honeycomb segments.

[2] The method for manufacturing a honeycomb structure according to [1], wherein the auxiliary heat transfer member is made of metal or alloy fibers.

[3] The honeycomb structure according to [2], wherein the thickness of the metal or alloy fiber is 10 to 50% of the distance between the side surfaces of the two honeycomb segments to be joined. Production method.

[4] The honeycomb structure according to [2] or [3], wherein the heat transfer auxiliary member is arranged by winding the metal or alloy fiber around the side portion of at least one of the honeycomb segments. manufacturing method.

[5] The method for manufacturing a honeycomb structure according to [1], wherein the auxiliary heat transfer member is a mesh member made of metal or alloy.

[6] the end faces of the honeycomb segments are square, and the end faces of the assembly obtained by combining the honeycomb segments in a lattice shape are square;
In the assembly manufacturing step, a range surrounded by 50% of the length of one side of the end face of the assembly centered on the center of gravity of one end face side of the assembly of the honeycomb segment (2) The method for manufacturing a honeycomb structure according to any one of [1] to [5], wherein at least the honeycomb segment provided with the heat transfer auxiliary member is disposed.

[7] The method for manufacturing a honeycomb structure according to any one of [1] to [6], wherein in the joined body manufacturing step, the assembly of the honeycomb segments is heated to 100° C. or higher.

[8] Any one of the above [1] to [7], further comprising a bonded body grinding step, which is a step performed after the bonded body manufacturing step, in which the outer periphery of the bonded body is ground into a desired shape. A method for manufacturing the honeycomb structure described above.

According to the method for manufacturing a honeycomb structure of the present invention, it is possible to improve the bonding strength of the bonding layer that bonds a plurality of honeycomb segments. That is, in the assembly manufacturing process, by disposing a fibrous or net-like heat transfer auxiliary member on the side portion of at least one honeycomb segment, the drying of the bonding paste is accelerated when the honeycomb segment assembly is dried. can be made Therefore, the bonding layer formed by drying the bonding paste becomes a dense porous body, and the bonding strength of the bonding layer can be improved.

1 is a perspective view schematically showing a honeycomb structure manufactured by one embodiment of the method for manufacturing a honeycomb structure of the present invention; FIG. Fig. 2 is a plan view showing the first end face side of the honeycomb structure shown in Fig. 1; FIG. 3 is a cross-sectional view schematically showing an A-A′ cross section of FIG. 2; 3 is a cross-sectional view schematically showing a B-B' cross section of FIG. 2; FIG. Fig. 2 is a perspective view schematically showing a honeycomb segment produced by a honeycomb segment producing step in one embodiment of the method for producing a honeycomb structure of the present invention; FIG. 4 is a schematic diagram illustrating a part of the assembly manufacturing process in one embodiment of the method for manufacturing a honeycomb structure of the present invention. FIG. 4 is a schematic diagram illustrating a part of the assembly manufacturing process in one embodiment of the method for manufacturing a honeycomb structure of the present invention. FIG. 4 is a schematic diagram illustrating a part of the assembly manufacturing process in one embodiment of the method for manufacturing a honeycomb structure of the present invention. FIG. 4 is a schematic diagram illustrating a part of the assembly manufacturing process in one embodiment of the method for manufacturing a honeycomb structure of the present invention. FIG. 5 is a plan view for explaining an example of an arrangement location of a heat transfer auxiliary member in an assembly manufacturing process; FIG. 11 is a plan view for explaining another example of the location where the heat transfer auxiliary member is arranged in the assembly manufacturing process; FIG. 10 is a plan view for explaining still another example of the location where the heat transfer auxiliary member is arranged in the assembly manufacturing process; FIG. 10 is a plan view for explaining still another example of the location where the heat transfer auxiliary member is arranged in the assembly manufacturing process;

Embodiments of the present invention will be described below, but the present invention is not limited to the following embodiments. Therefore, it is understood that the following modifications, improvements, etc., to the following embodiments are also included in the scope of the present invention without departing from the spirit of the present invention, based on the ordinary knowledge of those skilled in the art. should.

(1) Manufacturing method of honeycomb structure:
One embodiment of the method for manufacturing a honeycomb structure of the present invention is a method for manufacturing a honeycomb structure 100 as shown in FIGS. 1 to 4. FIG. Here, FIG. 1 is a perspective view schematically showing a honeycomb structure manufactured by one embodiment of the method for manufacturing a honeycomb structure of the present invention. 2 is a plan view showing the first end face side of the honeycomb structure shown in FIG. 1. FIG. FIG. 3 is a cross-sectional view schematically showing the AA' cross section of FIG. FIG. 4 is a cross-sectional view schematically showing the BB' cross section of FIG.

The honeycomb structure 100 shown in FIGS. 1 to 4 is a honeycomb structure 100 including a plurality of honeycomb segments 4 and a joining layer 14 that joins side surfaces of the plurality of honeycomb segments 4 to each other. In the honeycomb structure 100, the side surfaces of a plurality of honeycomb segments 4 are joined together by the joining layers 14 to form one honeycomb-shaped structure.

The honeycomb segment 4 is prismatic and has porous partition walls 1 arranged to surround a plurality of cells 2 and segment outer walls 3 (see FIG. 5) arranged to surround the partition walls 1. . Hereinafter, one end face of the prismatic honeycomb segment 4 is referred to as "first end face 11", and the other end face of the prismatic honeycomb segment 4 is referred to as "second end face 12". The segment outer wall 3 of the honeycomb segment 4 constitutes the side surface of the prismatic honeycomb segment 4 . The honeycomb structure 100 shown in FIGS. 1 to 4 further has an outer peripheral wall 13 arranged so as to surround the plurality of honeycomb segments 4 joined by the joining layer.

The method for manufacturing a honeycomb structure of the present embodiment includes a "honeycomb segment manufacturing process", an "assembly manufacturing process", and a "bonded body manufacturing process".

In the honeycomb segment manufacturing process, as shown in FIG. This is the step of producing a plurality of segments 4 . FIG. 5 is a perspective view schematically showing a honeycomb segment produced by a honeycomb segment producing step in one embodiment of the method for producing a honeycomb structure of the present invention.

As shown in FIGS. 6 to 9, the assembly production step is a step of producing an assembly 10 of honeycomb segments 4 by combining a plurality of honeycomb segments 4 in a lattice. More specifically, in the assembly manufacturing process, first, the bonding paste 14a is applied to the side surface of the honeycomb segment 4 (in other words, the "segment outer wall 3"). Next, a plurality of honeycomb segments 4 are combined in a grid pattern with the bonding paste 14a interposed between the side surfaces of the honeycomb segments 4 to produce an assembly 10 of the honeycomb segments 4 . 6 to 9 are schematic diagrams explaining a part of the assembly manufacturing process in one embodiment of the method for manufacturing a honeycomb structure of the present invention.

The bonded body manufacturing step is a step of drying the assembly 10 of the honeycomb segments 4 and bonding the side surfaces of the plurality of honeycomb segments 4 with the bonding paste 14a to manufacture a bonded body of the honeycomb segments 4 . The bonded body manufacturing process is mainly a process for drying and solidifying the bonding paste 14a for bonding the side surfaces of the honeycomb segments 4. The dried and solidified bonding paste 14a is shown in FIGS. 1 to 4. It becomes the bonding layer 14 in the honeycomb structure 100 , and a desired bonding force is developed in the bonding layer 14 by drying and solidification.

In the manufacturing method of the honeycomb structure of the present embodiment, the main configuration is that the “assembly manufacturing step” further includes the following operations. That is, as shown in FIG. 6, in the assembly manufacturing process, a fibrous or net-like heat transfer auxiliary member 15 is arranged on the side portion of at least one honeycomb segment 4 (in other words, the surface of the segment outer wall 3). It further includes the operation of setting. The operation of disposing the heat transfer auxiliary member 15 is preferably performed before applying the bonding paste 14 a to the side surface of the honeycomb segment 4 . Even if the auxiliary heat transfer member 15 is arranged before the bonding paste 14a is applied, the bonding paste 14a reaches the side surfaces of the honeycomb segments 4 through the fibers or meshes of the heat transfer auxiliary member 15, It does not interfere with subsequent assembly fabrication steps.

After the auxiliary heat transfer member 15 is arranged on the side surface of at least one honeycomb segment 4, as shown in FIG. ) is coated with a bonding paste 14a. After that, a plurality of honeycomb segments 4 are combined in a grid pattern with the bonding paste 14a interposed between the side surfaces of the honeycomb segments 4 to produce an assembly 10 of the honeycomb segments 4 .

In the manufacturing method of the honeycomb structure of the present embodiment, after disposing the auxiliary heat transfer member 15 as described above on the side surface portion of the honeycomb segment 4 in the "assembly manufacturing process", in the joined body manufacturing process, The bonding paste 14a is dried. According to the honeycomb structure manufacturing method configured in this way, it is possible to accelerate the drying of the bonding paste 14a when the assembly 10 of the honeycomb segments 4 is dried. Therefore, the bonding layer 14 (see FIG. 1) formed by drying the bonding paste 14a becomes a dense porous body, and the bonding strength of the bonding layer 14 (see FIG. 1) can be improved.

Each step of the manufacturing method of the honeycomb structure of the present embodiment will be described in more detail below.

(1-1) Honeycomb segment manufacturing process:
The honeycomb segment manufacturing step is a step of manufacturing a plurality of honeycomb segments 4 as shown in FIG. The honeycomb segment producing step can be carried out according to a method for producing a honeycomb segment in a conventionally known method for producing a honeycomb structure having a segmented structure. For example, the following methods can be mentioned.

First, a plastic clay for producing honeycomb segments is prepared. Clay for making honeycomb segments can be prepared by adding additives such as a binder, a pore-forming material, and water to raw material powders. The raw material powder is, for example, at least one selected from the group consisting of silicon carbide, cordierite, silicon-silicon carbide composite material, cordierite-silicon carbide composite material, silicon nitride, mullite, alumina and aluminum titanate. and ceramic powder containing.

Next, by extruding the clay thus obtained, a formed honeycomb segment body having partition walls defining a plurality of cells and outer segment walls surrounding the partition walls is formed. make.

Next, a honeycomb segment is manufactured by firing the formed honeycomb segment body. The firing temperature and firing atmosphere vary depending on the raw material, and those skilled in the art can select the optimal firing temperature and firing atmosphere for the selected material. There is no limit to the number of honeycomb segments 4 to be manufactured in the honeycomb segment manufacturing process, and the number necessary for manufacturing the honeycomb structure 100 (see FIG. 1) having a segment structure may be appropriately manufactured. In the honeycomb segment manufacturing step, if necessary, the openings of the cells 2 of the honeycomb segments 4 are alternately plugged at the ends on the first end surface 11 side or the second end surface 12 side. Plugging portions (not shown) may be provided.

(1-2) Assembly manufacturing process:
As shown in FIGS. 7 and 8, the assembly production process is a process of producing an assembly 10 of honeycomb segments 4 by combining a plurality of honeycomb segments 4 produced in the honeycomb segment production process in a grid pattern. . In the assembly manufacturing process, as shown in FIG. 6, first, a fibrous or net-like heat transfer auxiliary member 15 is arranged on the side portion of at least one honeycomb segment 4 . At least one honeycomb segment 4 on which the heat transfer auxiliary member 15 is arranged is sufficient. In particular, it is preferable that the honeycomb segments 4 on which the heat transfer auxiliary members 15 are arranged are arranged toward the inner side of the assembly 10 when the assembly 10 of the honeycomb segments 4 is produced.

The auxiliary heat transfer member 15 may be, for example, a fibrous auxiliary heat transfer member 15 made of metal or alloy fibers. The thickness of the metal or alloy fiber is preferably 10 to 50%, more preferably 20 to 40%, of the distance between the side surfaces of the two honeycomb segments 4 to be joined. The auxiliary heat transfer member 15 made of such fibers can favorably promote the drying of the bonding paste 14a. There are no particular restrictions on the density of the metal fibers, and the density is such that it has little effect on the bonding strength of the bonding layer 14 (see FIG. 1) formed by drying the bonding paste 14a and ensures good heat conduction. density. The distance between the side surfaces of the two honeycomb segments 4 to be joined is the distance between the sides when the honeycomb structure 100 (see FIG. 1, for example) is completed, taking into account the drying shrinkage of the joining paste 14a. .

The auxiliary heat transfer member 15 made of metal or alloy fibers can be arranged by winding metal or alloy fibers around the side portion of at least one honeycomb segment 4 . Therefore, the auxiliary heat transfer member 15 can be firmly arranged on the side surface portion of the honeycomb segment 4 .

Further, as the heat transfer auxiliary member 15, for example, a mesh-like heat transfer auxiliary member 15 configured by a mesh member made of metal or alloy can be used. Note that the net-like member is not limited to a knitted metal wire or the like, and may be, for example, a punching plate obtained by subjecting a plate-like member made of metal to a punching press. The thickness of the mesh member is not particularly limited, but for example, it is preferably 5 to 40%, more preferably 5 to 20%, of the distance between the side surfaces of the two honeycomb segments 4 to be joined. More preferred. When arranging the net-like members, it is possible to prepare a net-like member having approximately the same size as the side surface of the honeycomb segment 4, and to dispose the net-like member individually for each side portion of the honeycomb segment 4. . Alternatively, for example, the mesh member may be L-shaped, and the L-shaped mesh member may be arranged along the side surface of the honeycomb segment 4 . The distance between the side surfaces of the two honeycomb segments 4 to be joined is the distance between the sides when the honeycomb structure 100 (see FIG. 1, for example) is completed, taking into account the drying shrinkage of the joining paste 14a. .

The heat transfer auxiliary member preferably has a melting point of 700° C. or higher and a thermal conductivity of 15 W/mK or higher. Examples of materials that constitute the heat transfer auxiliary member include copper and stainless steel such as SUS304. Copper has a melting point of 1085° C. and a thermal conductivity of 385 W/mK. SUS304 has a melting point of 1400° C. and a thermal conductivity of 16 W/mK. Copper has excellent heat conductivity and corrosion resistance, and is available at low cost. For example, as the heat transfer auxiliary member 15 having a mesh structure made of copper, general-purpose products made of fine wires can be obtained. SUS304 is particularly excellent in corrosion resistance, and general-purpose products made of fine wires are available.

Also, in the assembly manufacturing process, the bonding paste 14a is separately prepared. A method for preparing the bonding paste 14a is not particularly limited, and it can be performed according to a method for preparing a bonding paste in a conventionally known method for manufacturing a honeycomb structure having a segment structure. For example, the bonding paste can be prepared by appropriately adding an additive such as a binder, a pore-forming material, and water to raw material powder for manufacturing the bonding paste.

Next, the prepared bonding paste 14a is applied to the surface of the segment outer wall 3, which is the side surface of the honeycomb segment 4. Next, as shown in FIG. As for the method of applying the bonding paste 14a and the like, the same methods as those used in conventionally known methods for manufacturing a honeycomb structure having a segment structure can be employed. The honeycomb segment 4 to which the honeycomb segment 4 is coated includes the honeycomb segment 4 having the heat transfer auxiliary member 15 arranged on the side surface portion as described above.

Next, a plurality of honeycomb segments 4 are combined in a grid pattern with the bonding paste 14a interposed between the side surfaces of the honeycomb segments 4 to produce an assembly 10 of the honeycomb segments 4 . The distance between the side surfaces of the honeycomb segments 4 (in other words, the thickness of the bonding paste 14a including the auxiliary heat transfer member 15) is not particularly limited, but considering the thickness of the auxiliary heat transfer member 15, It can be determined as appropriate. For example, the distance between the side surfaces of two honeycomb segments 4 to be joined is preferably 0.5 to 3.0 mm, more preferably 0.5 to 2.0 mm.

When fabricating the assembly 10 of the honeycomb segments 4 , it is preferable that the honeycomb segments 4 having the heat transfer auxiliary member 15 arranged inside the assembly 10 as much as possible. For example, the honeycomb segment 4 on which the heat transfer auxiliary member 15 is arranged has a length of 50% of the length of one side of the assembly 10 centered on the center of gravity of the assembly 10 of the honeycomb segments 4 on the first end face 11 side. It is preferably located at least within the range bounded by the length. By configuring in this way, the drying of the bonding paste 14a inside the assembly 10 can be accelerated.

(1-3) Joined body production process:
The bonded body manufacturing step is a step of drying the assembly 10 of the honeycomb segments 4 and bonding the side surfaces of the plurality of honeycomb segments 4 with the bonding paste 14a to manufacture a bonded body of the honeycomb segments 4 . In the manufacturing method of the honeycomb structure of the present embodiment, since the cylindrical heat transfer auxiliary member 15 is disposed at the intersection of the bonding paste 14a, the heat during drying reaches the inside of the assembly 10 in the axial direction. It is easy to transfer and can accelerate the drying of the joining paste 14a. Therefore, the bonding layer 14 (see FIG. 1) formed by drying the bonding paste 14a becomes a dense porous body, and the bonding strength of the bonding layer 14 (see FIG. 1) can be improved.

The drying method is not particularly limited, and examples thereof include electromagnetic heating methods such as microwave heating drying and high frequency dielectric heating drying, and external heating methods such as hot air drying and superheated steam drying. Among these, the entire molded body can be dried quickly and uniformly without cracks. It is preferable to let As for the drying conditions, it is preferable to remove 30 to 95% by mass of moisture with respect to the moisture content before drying by an electromagnetic wave heating method, and then reduce the moisture content to 3% by mass or less by an external heating method. As the electromagnetic wave heating method, dielectric heating drying is preferable, and as the external heating method, hot air drying is preferable. The drying temperature is preferably 90 to 180°C. The drying time is preferably 1 to 10 hours. In addition, it is also one of preferable modes to heat the assembly of the honeycomb segments to 100° C. or higher so that the moisture evaporates.

After the joined body of the honeycomb segments 4 is produced by the joined body producing step, the peripheral portion of the joined body thus obtained may be ground into a desired shape. Further, after grinding the outer peripheral portion of the joined body, an outer peripheral coat layer may be provided on the outer peripheral surface to produce the outer peripheral wall 13 (see FIG. 1) of the honeycomb structure 100 (see FIG. 1). . Each manufacturing process after such a joined body manufacturing process can be performed, for example, according to a conventionally known method for manufacturing a honeycomb structure having a segment structure. For example, there may be further provided a bonded body grinding step, which is a step that is performed after the bonded body manufacturing step and grinds the outer periphery of the bonded body of honeycomb segments into a desired shape. A honeycomb structure having a desired shape can be easily manufactured by further providing such a joined body grinding step.

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

(Example 1)
First, as raw material powder for preparing clay for manufacturing honeycomb segments, a mixed raw material was prepared by mixing silicon carbide (SiC) powder and metal silicon (Si) powder. Appropriate amounts of a binder, a pore-forming material, and water were added to the prepared mixed raw material to prepare a plastic clay.

Next, the obtained clay was molded using an extruder to produce 49 rectangular prism-shaped honeycomb molded bodies. Next, the obtained honeycomb formed body was dried by high-frequency dielectric heating, and then further dried by using a hot air dryer. Next, plugging portions were provided at the end portions of the cells of the dried honeycomb segment formed body so that the opening portions of the cells were alternately plugged on the first end face side and the second end face side. .

Next, the honeycomb segment molded body was degreased and fired to produce 49 honeycomb segments. The size of the end face of each honeycomb segment was a square with one side of 40 mm, and the axial length from the first end face to the second end face of each honeycomb segment was 300 mm.

Next, a fibrous heat transfer auxiliary member made of copper fibers was wound around the side surface of one honeycomb segment. The thickness of the copper fiber forming the heat transfer auxiliary member was 0.3 mm. The heat transfer used in Example 1 is shown in the columns of "arrangement method", "material", "fiber diameter or plate thickness (mm)" and "arrangement (reference diagram)" of "heat transfer auxiliary member" in Table 1. Shows information about auxiliary members. In the column of "arrangement method" of "heat transfer auxiliary member" in Table 1, when the fibrous heat transfer auxiliary member is wound around the side portion of the honeycomb segment as in Example 1, " winding of the fibrous member”. As will be described later, when the heat transfer auxiliary member made of the L-shaped net member is arranged on the side surface of the honeycomb segment, it is described as "arrangement of L-shaped net member". The "(mm)" column of "fiber diameter or plate thickness" in Table 1 indicates the diameter (mm) when the heat transfer auxiliary member is fibrous, and the mesh member or punching plate ( In the case of punching plate), the thickness (mm) is indicated. The column of "ratio (%) to bonding width" of "fiber diameter or plate thickness" in Table 1 shows the ratio of the thickness (mm) to the distance (mm) between the side surfaces of two honeycomb segments to be bonded ( percentage). In addition, the column of "arrangement (reference diagram)" of "heat transfer auxiliary member" in Table 1 shows reference diagrams related to the arrangement location of the heat transfer auxiliary member.

Next, a bonding paste, which is an SiC-based mortar adhesive, is applied to the side surfaces of the honeycomb segments, and the bonding paste is applied so that 49 honeycomb segments are arranged in each of the vertical and horizontal directions. An assembly of honeycomb segments was produced by combining them in a grid-like manner. The arrangement and the number of honeycomb segments in manufacturing a honeycomb segment assembly are shown in the columns of "arrangement" and "total number (pieces)" in "honeycomb segment" in Table 1. For example, when seven honeycomb segments are arranged in each of the vertical and horizontal directions as described above, "7×7" is indicated in the "arrangement" column. In Example 1, the honeycomb segments provided with the auxiliary heat transfer members were arranged so as to be positioned at the centers of the assembly in the vertical and horizontal directions. The distance between the side surfaces of the two honeycomb segments to be joined was 1 mm.

Next, the assembly in which the auxiliary heat transfer members were arranged at the intersections of the bonding paste was dried in an air atmosphere at 100° C. for 1 hour to produce a bonded body of honeycomb segments.

Next, the outer periphery of the manufactured joined body of honeycomb segments was ground into a cylindrical shape, and an outer peripheral coat layer was provided on the outer peripheral surface to manufacture a honeycomb structure. The honeycomb structure manufactured in Example 1 was a honeycomb structure 200 in which 49 honeycomb segments 4 were joined by a joining layer 14 like the honeycomb structure 200 shown in FIG. The honeycomb segment 4 located exactly in the center of the first end surface 11 of the honeycomb structure 200 had the fibrous heat transfer auxiliary member 15 wound around its side surface portion. Here, FIGS. 10 to 13 are plan views for explaining an example of locations where heat transfer auxiliary members are arranged in the assembly manufacturing process. In the honeycomb structures 200, 300, 400, 500 shown in FIGS. 10 to 13, the same components as those of the honeycomb structure 100 shown in FIGS. 1 to 4 are denoted by the same reference numerals, and descriptions thereof are omitted. .

For the honeycomb structure manufactured in Example 1, "evaluation of bonding strength of bonding layer" was performed by the following method. Table 1 shows the results.

[Evaluation of Bonding Strength of Bonding Layer]
First, the bonding strength of the bonding layer of the honeycomb structure manufactured in each example and comparative example was measured by the following method. First, for the honeycomb structures of each example and comparative example, a bonding layer to be evaluated for bonding strength was determined, and two honeycomb segments including the bonding layer to be evaluated were cut out by machining and used for bonding strength evaluation. A test piece was produced. The two honeycomb segments including the bonding layer to be evaluated are two honeycomb segments bonded by the bonding layer to be evaluated. Next, the prepared test piece was placed and fixed on a test table. When fixing the test piece, only the bottom surface of one honeycomb segment included in the test piece was placed on the test table, and the test piece was firmly fixed on the test table so that it would not fall over. Next, a compression tester was used to apply a load to the top surface of the honeycomb segment of the test piece which was not placed on the test stand, and the load at which the bonding layer was destroyed was measured. The load at which the bonding layer broke was taken as the bonding strength of the bonding layer. In the evaluation of the bonding strength of the bonding layer, the bonding strength of the bonding layer of the honeycomb structure manufactured in Comparative Examples 1 and 2 described later was used as a reference value, and the ratio of the bonding strength of the bonding layer of the honeycomb structure to be evaluated was obtained. rice field. Comparative Example 1 was used as a reference for Examples 1 to 4, 9 to 12, and 17 to 20. Comparative Example 2 was used as a reference for Examples 5 to 8, 13 to 16, and 21 to 24.

(Examples 2-6)
In Examples 2 to 6, the "material", "fiber diameter (mm)", and "arrangement (reference diagram)" of the heat transfer auxiliary member were changed as shown in Table 1 to fabricate a honeycomb structure. bottom. Regarding the manufacturing process other than those shown in the columns of "Material", "Fiber diameter or plate thickness (mm)", and "Arrangement (reference diagram)" of "Heat transfer auxiliary member" in Table 1, see Example 1 A honeycomb structure was manufactured by the same manufacturing process as in the above. In Examples 5 and 6, a stainless steel SUS304 member was used as the heat transfer auxiliary member.

(Comparative example 1)
In Comparative Example 1, a honeycomb structure was produced by the same manufacturing process as in Example 1, except that the auxiliary heat transfer member was not arranged on the side surface portion of the honeycomb segment.

(Examples 7-10)
In Examples 7 to 10, honeycomb structures were produced by changing the size and the number of honeycomb segments used. The size of the end faces of the honeycomb segments produced in Examples 7 to 10 was a square with one side of 40 mm, and the axial length from the first end face to the second end face of each honeycomb segment was 230 mm. rice field. Thirty-six of such honeycomb segments were produced, and were combined in a grid pattern with bonding paste interposed so that six each were arranged in the vertical and horizontal directions to produce a honeycomb segment assembly. In Examples 7 to 10, the method of arranging the auxiliary heat transfer member and the material thereof are as shown in Table 1.

(Comparative example 2)
In Comparative Example 2, a honeycomb structure was produced by the same manufacturing process as in Example 7, except that the auxiliary heat transfer member was not arranged on the side surface portion of the honeycomb segment.

(Examples 11 to 14)
In Examples 11 to 14, a mesh member made of tough pitch copper (“C1100” in JIS H 3100) having a Cu purity of 99.90% by mass or more was prepared as a heat transfer auxiliary member. Then, this mesh member was L-shaped, and a heat transfer auxiliary member made of the L-shaped mesh member was used. In addition, regarding the manufacturing process other than those shown in the columns of "arrangement method", "material", "fiber diameter or plate thickness (mm)", and "arrangement (reference diagram)" of "heat transfer auxiliary member" in Table 2 manufactured a honeycomb structure by the same manufacturing process as in Example 1.

(Examples 15-18)
Also in Examples 15-18, a heat transfer auxiliary member having the same structure as that used in Examples 11-14 was used. In addition, regarding the manufacturing process other than those shown in the columns of "arrangement method", "material", "fiber diameter or plate thickness (mm)", and "arrangement (reference diagram)" of "heat transfer auxiliary member" in Table 2 manufactured a honeycomb structure by the same manufacturing process as in Example 7.

(Examples 19-27)
In Examples 19 to 27, punching plates made of materials shown in Table 2 were prepared as heat transfer auxiliary members. Then, this punching plate was arranged on the side surface portion of the honeycomb segment in the arrangement shown in Table 2, "Arrangement (reference diagram)", to fabricate a honeycomb structure. In addition, regarding the manufacturing process other than those shown in the columns of "arrangement method", "material", "fiber diameter or plate thickness (mm)" and "arrangement (reference diagram)" of "heat transfer auxiliary member" in Table 2 , a honeycomb structure was produced by the same manufacturing process as in Example 1.

The honeycomb structures manufactured in Examples 2 to 27 and Comparative Examples 1 and 2 were also subjected to the "bonding strength evaluation of the bonding layer" by the method described above. Table 1 shows the results.

(result)
It was confirmed that the honeycomb structures manufactured in Examples 1 to 6, 11 to 14, and 19 to 23 had improved bonding strength of the bonding layers compared to the honeycomb structure manufactured in Comparative Example 1. was done. It was confirmed that the honeycomb structures manufactured in Examples 7 to 10, 15 to 18, and 24 to 27 also had improved bonding strength of the bonding layers compared to the honeycomb structure manufactured in Comparative Example 2. was done.

As for the material of the heat transfer auxiliary member, it was found that the bonding strength of the bonding layer was improved more when copper was used than when SUS304 was used. Moreover, the result was obtained that the bonding strength of the bonding layer was improved as the number of honeycomb segments in which the heat transfer auxiliary members were arranged was increased.

The method for manufacturing a honeycomb structure of the present invention can be used as a method for manufacturing a honeycomb structure as a purification member for purifying exhaust gas.

1: partition wall, 2: cell, 3: segment outer wall, 4: honeycomb segment, 10: honeycomb segment assembly, 11: first end face, 12: second end face, 13: outer peripheral wall, 14: bonding layer, 14a: Joining paste, 15: heat transfer auxiliary member, 100, 200, 300, 400, 500: honeycomb structure.

Claims (8)

a honeycomb segment manufacturing step of manufacturing a plurality of prismatic honeycomb segments having porous partition walls arranged to surround a plurality of cells and segment outer walls arranged to surround the partition walls;
A bonding paste is applied to the side surfaces of the honeycomb segments, and a plurality of the honeycomb segments are combined in a lattice with the bonding paste interposed between the side surfaces of the plurality of honeycomb segments. an assembly manufacturing step of manufacturing an assembly of honeycomb segments;
a bonded body manufacturing step of drying the assembly of the honeycomb segments and bonding the side faces of a plurality of the honeycomb segments together with the bonding paste to manufacture a bonded body of the honeycomb segments;
In the assembly manufacturing step, a fibrous or net-like heat transfer auxiliary member is provided on a side portion of at least one of the honeycomb segments, and a plurality of the honeycomb segments including the honeycomb segment provided with the heat transfer auxiliary member are arranged. A method for manufacturing a honeycomb structure, comprising combining honeycomb segments to manufacture the assembly of the honeycomb segments. The method for manufacturing a honeycomb structure according to claim 1, wherein the heat transfer auxiliary member is made of metal or alloy fibers. 3. The method for manufacturing a honeycomb structure according to claim 2, wherein the thickness of said metal or alloy fiber is 10 to 50% of the distance between the side surfaces of said two honeycomb segments to be joined. 4. The method for manufacturing a honeycomb structure according to claim 2, wherein the heat transfer auxiliary member is arranged by winding the metal or alloy fiber around the side portion of at least one of the honeycomb segments. The method for manufacturing a honeycomb structure according to claim 1, wherein the heat transfer auxiliary member is a mesh member made of metal or alloy. end faces of the honeycomb segments are square, and an end face of the assembly obtained by combining the honeycomb segments in a lattice shape is square;
In the assembly manufacturing step, a range surrounded by 50% of the length of one side of the end face of the assembly centered on the center of gravity of one end face side of the assembly of the honeycomb segment 6. The method for manufacturing a honeycomb structure according to any one of claims 1 to 5, wherein at least the honeycomb segments provided with the heat transfer auxiliary members are arranged in the. The method for manufacturing a honeycomb structure according to any one of claims 1 to 6, wherein in the bonded body manufacturing step, the assembly of the honeycomb segments is heated to 100°C or higher. The honeycomb structure according to any one of claims 1 to 7, further comprising a joined body grinding step, which is a step that is performed after the joined body manufacturing step and grinds the outer periphery of the joined body into a desired shape. body manufacturing method.

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