Method for producing a honeycomb structure

Abstract

Method for producing a honeycomb structure (40, 100) for fine particle capture filters, wherein the honeycomb structure (40, 100) comprises several porous honeycomb structure segments (10, 50) connected to one another via binder material layers (54), each porous honeycomb structure segment (10, 50) comprising: partitions (52) made of a SiC material, the partitions (52) defining several cells (51) forming flow paths for a fluid, each of the cells (51) extending from an inlet surface, which is an end surface on the fluid inlet side, to a fluid outlet surface, which is an end surface on the fluid outlet side; and an outer circumferential wall (53) located at the outermost perimeter, wherein the method: the joining of each of the porous honeycomb segments (10, 50) via the binding material layers (54) by applying a binding material between the connecting surfaces of each of the porous honeycomb structure segments (10, 50) by means of a nozzle section of a binding material applicator, wherein the nozzle section (60) of the binding material applicator: a binding material inlet opening (61); a binding material outlet chamber (63) with a slot-shaped binding material outlet opening (64) for dispensing an introduced binding material; and a binding material flow path (62) with a curved section through which the binding material passes from the binding material inlet opening (61) to the binding material outlet space (63) and wherein the binder material flow path (62) of the nozzle section (60) includes a buffer space (68, 69) which is designed such that a flow path cross-section expands stepwise in the direction of the binder material outlet space (63) on a downstream side of the curved section.

Description

TECHNICAL AREA

[0001] The present invention relates to a method for producing a honeycomb structure. More precisely, it relates to a method for producing a honeycomb structure which improves the manufacturing efficiency of the honeycomb structure by preventing application unevenness that arises when applying a binding material to the surfaces of honeycomb segments and by preventing binding material from dripping from a binding material outlet opening of a nozzle section of a binding material applicator. BACKGROUND TECHNOLOGY

[0002] A typical internal combustion engine includes a diesel particulate filter (DPF) to trap fine particles contained in the exhaust gas from a diesel engine. It may also include a gasoline particulate filter (GPF) to trap fine particles contained in the exhaust gas from a gasoline engine. Both the DPF and GPF are formed by bonding multiple porous silicon carbide (SiC) honeycomb segments with a bonding agent. Their structure is created by grinding the outer circumference of a segmented composite body with the bonded honeycomb segments to form a honeycomb structure with a suitable shape, such as a circle or ellipse, and then coating the outer surface with a coating material.

[0003] Patent document 1 discloses a method for producing a honeycomb structure by joining several porous honeycomb segments using a binding material to create a segmented composite body. In the method for producing the honeycomb structure as described in patent document 1, as described in Fig. Figure 1 shows that several porous honeycomb segments 10 are stacked along an L-shaped receiving plate 30 over adhesive layers 20 to obtain a desired stacked structure, and then pressure is applied to the entire structure. In this way, a segmented composite body (honeycomb structure 40) is produced in which the porous honeycomb segments 10 are stacked vertically and horizontally.

[0004] Furthermore, CN 1 05 921 360 A describes a coating applicator with an inlet opening, a slotted outlet opening, and a material flow path with a curved section through which the material passes from the inlet opening to the outlet chamber. LIST OF LITERATURES Patent Literature

[0005] Patent document 1: Japanese patent application, publication number 2004-262670 A SUMMARY OF THE INVENTION Technical Problem

[0006] In the production of the composite body from the porous honeycomb segments 10, as described in Fig. As shown in Figure 1, the bonding material is typically applied between adjacent porous honeycomb segments 10 from the nozzle section of the bonding material applicator, forming the adhesive layers 20. However, due to recent regulations, replacing the bonding material with a refractory ceramic fiber (RCF)-free bonding material alters the properties of the conventional bonding material, leading to the problem that the bonding material cannot be applied uniformly. More precisely, when a bonding material with a more pronounced thixotropic property is applied, the bonding material's responsiveness is poor; for example, the bonding material does not react immediately to stress, resulting in uneven application of the bonding material.

[0007] Specifically, when the binding material is applied to the surfaces of the porous honeycomb segments through the nozzle section of the binding material applicator, there can be an application start point and an application end point for the binding material, as in Fig. Figure 1 shows that unevenness in the application can occur. Furthermore, vibration of the binding material between the application start point and the application end point can also lead to unevenness in the application.

[0008] As in Fig. As shown in Figure 3, the application width of the binding material can also be uneven. Increasing the application quantity to correct this unevenness will cause the problem that, if the honeycomb segments are as shown in Figure 3, the binding material will not be applied evenly. Fig. 4 shown, when connected, an excess amount of the binding material leaks out, thereby reducing the utilization efficiency of the binding material.

[0009] Furthermore, when the binding material is applied through the nozzle section of the binding material applicator, the binding material is not applied evenly through the nozzle section, and a larger amount of the binding material may drip from the binding material outlet opening of the nozzle section, as shown in Fig. Figure 5 shows that if a larger quantity of the binding material drips out, this leads to the problem that the nozzle section has to be cleaned frequently.

[0010] All the problems described above lead to a deterioration in the manufacturing efficiency of the honeycomb structure. In light of these circumstances, an object of the present invention is to prevent unevenness in the application of the binding material to the surfaces of the honeycomb segments and to prevent binding material from dripping from the binding material outlet opening of the nozzle section of the binding material applicator, thereby improving the manufacturing efficiency of the honeycomb structure. Solution to the problem

[0011] As a result of intensive studies, the inventors suspected that the uneven application of the binding material and the dripping of the binding material from the nozzle section of the binding material applicator were caused by pressure from the binding material generated within the nozzle section. The inventors then discovered that these problems could be solved by giving the nozzle section of the binding material applicator a specific structure. Therefore, the present invention is specified as follows: A method for producing a honeycomb structure for fine particle capture filters, wherein the honeycomb structure comprises several porous honeycomb structure segments connected to each other via layers of binder material, each porous honeycomb structure segment comprising: partitions made of a SiC material, the partitions defining several cells that form flow paths for a fluid, each of the cells extending from an inlet face, which is an end face on the fluid inlet side, to a fluid outlet face, which is an end face on the fluid outlet side; and an outer circumferential wall located at the outermost perimeter, wherein the method: The process involves connecting each of the porous honeycomb segments across the binding material layers by applying a binding material between the connecting surfaces of each of the porous honeycomb structure segments through a nozzle section of a binding material applicator. wherein the nozzle section of the binding material applicator: a binding material inlet opening; a binding material outlet chamber with a slot-shaped binding material outlet opening for dispensing introduced binding material; and a binding material flow path with a curved section through which the binding material travels from the binding material inlet opening to the binding material outlet space and wherein the binder material flow path of the nozzle section includes a buffer space which is designed such that a flow path cross-section expands stepwise in the direction of the binder material outlet space on an outflow side of the bent section. Advantageous effects of the invention

[0012] According to the present invention, unevenness in the application of the binding material to the surfaces of the honeycomb segments can be prevented, and binding material can be prevented from dripping out of the binding material outlet opening of the nozzle section of the binding material applicator, thereby improving the manufacturing efficiency of the honeycomb structure. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a schematic view showing a conventional honeycomb segment and a method of manufacturing a segmented composite body by connecting the honeycomb segments. Fig. Figure 2 is a photograph showing the appearance, which reveals uneven application and vibration of a binding material in the conventional honeycomb segment. Fig. Figure 3 is a photograph showing the appearance, which reveals a variation in the application width of a binding material in the conventional honeycomb segment. Fig. Figure 4 is a photograph showing the appearance of extrusions of a binding material in the conventional segmented composite body. Fig. Figure 5 is a photograph showing the appearance of a binding material being dispensed from a binding material outlet opening of a nozzle section of a conventional binding material applicator. Fig. Figure 6 is a schematic external view of a honeycomb structure according to an embodiment of the present invention. Fig. Figure 7 is a schematic external view of a porous honeycomb segment according to an embodiment of the present invention. Fig. Figure 8 is a photograph showing the appearance of a nozzle section 60 of a binding material applicator according to an embodiment of the present invention. Fig. Figure 9 is a photograph for viewing the appearance, which schematically shows an internal structure of the nozzle section 60 of the binding material applicator according to an embodiment of the present invention. Fig. Figure 10 is a photograph showing the appearance of a flat spacer dividing a binder outlet space of a nozzle section body according to an embodiment of the present invention. Fig. 11 (a), (b) and (c) are each photographs showing the appearance of flat spacers dividing a buffer space according to an embodiment of the present invention. DESCRIPTION OF PREFERRED EXECUTION FORMS

[0013] Embodiments of a honeycomb structure according to the present invention are described below, specifically with reference to the drawings. It is understood that the present invention is not limited to the following embodiments, and various design modifications and improvements can be made based on the ordinary knowledge of a person skilled in the art without departing from the scope of the present invention. (Method for producing a honeycomb structure)

[0014] Fig. Figure 6 is a schematic external view of a honeycomb structure 100 produced by a honeycomb structure production method according to an embodiment of the present invention. The honeycomb structure 100 is formed by bonding several porous honeycomb structure segments 50 together via bonding material layers 54, each porous honeycomb structure segment 50 comprising: partition walls 52 made of a SiC material, defining several cells 51, forming flow paths for a fluid and extending from an inlet face, which is an end face on the fluid inlet side, to an outlet face, which is an end face on the fluid outlet side; and an outer circumferential wall 53 located at the outermost perimeter.In this context, SiC material refers to a material primarily based on SiC (silicon carbide), including, for example, a material consisting only of SiC, such as recrystallized SiC, Si-SiC-based composite materials, cordierite-SiC-based composite materials, SiC impregnated with metallic silicon, and the like.

[0015] The honeycomb structure 100 is formed by grinding the outer circumference into a suitable shape, such as a circle or an elliptical shape, and then coating the outer surface with a coating material. It is used as a fine particle capture filter, such as a diesel particulate filter (DPF) or a gasoline particulate filter (GPF). The inlet or outlet surfaces of the cells 51, which serve as the flow paths for the fluid in the honeycomb structure 100, are provided with sealed sections, enabling the capture of fine particles (such as soot) in exhaust gas. Although the sealed sections can be created at any time, they are preferably created before the firing of the porous honeycomb segments 50, since the sealed sections and the partitions 52 are sintered by the firing process.

[0016] Regarding the honeycomb structure 100, a catalyst can further be provided on the surfaces or the inside of the partitions 52 made of a SiC material that define the multiple cells 51. The type of catalyst is not particularly restricted and can be chosen appropriately according to the intended use and application of the honeycomb structure 100. Examples of the catalyst include precious metal catalysts or catalysts other than these. Illustrative examples of precious metal catalysts include a three-way catalyst and an oxidation catalyst obtained by carrying a precious metal such as platinum (Pt), palladium (Pd), and rhodium (Rh) on the surfaces of pores made of aluminum oxide and incorporating a co-catalyst such as cerium and zirconium dioxide, or a lean NO₂ catalyst. x -Trap catalyst (LNT catalyst), which uses an alkaline earth metal and platinum as storage components for nitrogen oxides (NOx). x). Illustrative examples of a catalyst that does not use a precious metal include a catalyst for the selective catalytic reduction of NO. x (SCR catalyst) containing a copper-substituted or iron-substituted zeolite, and the like. Furthermore, two or more catalysts selected from the group consisting of these catalysts may be used. A method for carrying the catalyst is not particularly restricted and may be carried out according to a conventional method for carrying the catalyst on the honeycomb structure 100.

[0017] In the process for producing the honeycomb structure according to an embodiment of the present invention, porous honeycomb segments 50 are first produced, as in Fig. Figure 7 shows how to manufacture the porous honeycomb segments 50. As for the manufacturing step, a binder, a dispersant (surfactant), a pore-forming agent, water, and the like are first added to a ceramic raw material made of a SiC material. These are mixed and kneaded to produce a green body. The resulting green body is then extruded into a honeycomb shape, yielding a raw (unfired) columnar honeycomb body. The extruded columnar honeycomb body is cut to a suitable length. The extrusion process can be carried out using equipment such as a piston extruder, a biaxial continuous screw extruder, or the like. For forming the honeycomb shape, a method using a die with the desired cell shape, septum thickness, and cell density is preferred.This is how an unfired honeycomb molded body is produced.

[0018] The external shape of the unfired columnar honeycomb structure is not particularly restricted, and it can be a columnar shape with rectangular end faces as in the present embodiment, or a columnar shape with circular end faces (circular columnar shape), or a columnar shape with polygonal (triangular, pentagonal, hexagonal, heptagonal, octagonal, etc.) end faces, except for rectangular end faces.

[0019] The unfired honeycomb mold is then dried to produce a dried honeycomb body. Drying can be achieved by dielectric drying using high-frequency energy, generated by passing an electric current through the porous honeycomb segments 50, or by hot air drying, in which hot air is introduced into the porous honeycomb segments 50. Alternatively, natural drying at room temperature, microwave drying using microwaves, freeze-drying, or a combination of several drying methods can be used. The dried honeycomb body is then fired. In this process, sealed sections are created by sintering a sealing material onto both end faces of the dried honeycomb body, forming segments for filtering fine particles (soot, etc.) from exhaust gas. The sealed sections are formed on both end faces of each cell.If a cell is sealed at one end face, the opposite end face remains open. Such sealing can create a filtering effect. This is how the porous honeycomb segments 50 are produced.

[0020] The binding material is applied to each of the multiple porous honeycomb segments 50 between the connection surfaces using the binding material applicator to bond them across the binding material layers 54. In the bonding step, multiple porous honeycomb segments 50 can be bonded along an L-shaped receiving plate across the binding material layers 54 using the applicator. Fig. The components are stacked according to the method shown in section 1 to form the desired stacked structure, and then pressure can be applied to the entire structure to join them together. Thus, the components in the Fig. 6 honeycomb structures shown, 100 produced.

[0021] The binding material forming the binding material layers 54 is not particularly restricted, as long as it can bond the surfaces of the outer circumferential walls 53 made of the SiC material with good adhesive strength. The binding material forming the binding material layers 54 can, for example, contain inorganic particles, inorganic fibers, and colloidal oxides as other components. Furthermore, during the bonding of the porous honeycomb segments 50, in addition to these components, an organic binder such as methylcellulose and carboxymethylcellulose, a dispersant, water, and the like can optionally be added, and everything mixed and kneaded using a kneading machine such as a mixer to form a paste that can be used as a binding material.

[0022] Examples of materials for forming the inorganic particles contained in the binder material forming the binder material layers 54 include ceramics selected from the group consisting of silicon carbide, silicon nitride, cordierite, aluminum oxide, mullite, zirconium dioxide, zirconium phosphate, aluminum titanate, titanium dioxide and combinations thereof; Fe-Cr-Al-based metals; nickel-based metals; silicon-silicon carbide-based composite materials and the like.

[0023] Examples of inorganic fibers contained in the binder material forming the binder layers 54 include ceramic fibers such as aluminosilicate and silicon carbide, and metal fibers such as copper and iron. Suitable colloidal oxides include silica sol, aluminum oxide sol, and the like. The colloidal oxides are suitable for imparting appropriate adhesive strength to the binder material and can also be bonded to the inorganic fibers and particles by drying and degreasing, thus providing a strong binder material with improved heat resistance after drying.

[0024] In the method for producing the honeycomb structure according to one embodiment of the present invention, a nozzle section of the binding material applicator, which has the following structure, is used between the connecting surfaces when applying the binding material to each of the several porous honeycomb segments 50. This prevents unevenness in the application of the binding material to the surfaces of the honeycomb segments and prevents binding material from dripping from a binding material outlet opening of the nozzle section of the binding material applicator. As a result, the production efficiency of the honeycomb structure can be improved. (Structure of the nozzle section of the binding material applicator)

[0025] Fig. Figure 8 is a photograph showing the appearance of a nozzle section 60 of the binding material applicator according to an embodiment of the present invention. Fig. Figure 9 is a photograph for viewing the appearance, which schematically shows an internal structure of the nozzle section 60 of the binding material applicator according to an embodiment of the present invention.

[0026] The nozzle section 60 of the binding material applicator comprises a nozzle section base body 66 and a spacer 67. The nozzle section base body 66 includes: a binding material inlet opening 61 into which the binding material prepared in the binding material applicator is introduced; a binding material outlet chamber 63 with a slot-shaped binding material outlet opening 64 for releasing the introduced binding material; and a binding material flow path 62 with a curved section 65 through which the binding material passes from the binding material inlet opening 61 to the binding material outlet chamber 63. The spacer 67 is inserted into the binding material outlet chamber 63 of the nozzle section base body 66.

[0027] The nozzle section base body 66 can be formed from any material known for use in a binder application nozzle. For example, the nozzle section base body 66 can be formed from aluminum, iron, copper, or an alloy such as SUS, or from a resin such as polyethylene, vinyl chloride, fluorocarbon resin, and polycarbonate.

[0028] The cross-sections of the flow path for the binding material in the binding material inlet opening 61 and of the binding material flow path 62 can have any shape, including, for example, a circular, elliptical, or polygonal shape. The size of the cross-section of the flow path for the binding material can be designed to suit the size of the nozzle section 60 and the like; for example, the cross-section can be circular with a diameter of 5.0 to 20.0 mm.

[0029] The binding material flow path 62 has the curved section 65. Fig. Figure 9 illustrates a structure in which the binding material flow path 62, connected to the binding material inlet opening 61, runs straight ahead, bends approximately 90° at the curved section 65, and proceeds to the binding material outlet chamber 63 on the downstream side of the curved section 65. The binding material flow path 62 is not restricted to bending approximately 90° at the curved section 65 as described above and can bend at any angle. The binding material introduced from the binding material inlet opening 61 into the binding material flow path 62 is thinned in the binding material outlet chamber 63 by traversing the curved section 65 and is discharged through the binding material outlet opening 64.The curved section 65 can prevent a difference in flow velocity between both ends and the center of the slotted binding material outlet opening 64 when the binding material is thinned with the aid of the binding material outlet space 63.

[0030] The size of the slotted binding material outlet opening 64 of the binding material outlet chamber 63 can be designed to suit the size of the nozzle section 60, the application width, and the application quantity of the binding material. For example, the slotted binding material outlet opening 64 can be made rectangular with a length of 60 mm and a width of 25 to 45 mm. The binding material outlet chamber 63 can be modified by inserting a flat spacer, as shown in Fig. 10 shows that the binder material outlet chamber 63 of the nozzle section base body 66 is formed to divide it. In the process, using the in Fig. In the flat spacer shown in Figure 10, the divided binding material outlet chamber 63 has a chamber width 70 that increases towards the binding material outlet opening 64. Consequently, the binding material outlet chamber 63 can be configured such that the cross-sectional area of ​​the flow path for the binding material extends from the point where the binding material is introduced from the binding material flow path 62 to the point where it is discharged through the binding material outlet opening 64. This structure prevents a difference in flow velocity between the two ends and the center of the slot-shaped binding material outlet opening 64.

[0031] The binding material flow path 62 includes a buffer chamber 68, which adjoins the binding material outlet chamber 63 on the downstream side of the curved section 65 and is designed such that the flow path cross-section expands stepwise towards the binding material outlet chamber 63. Binding material that has traversed the binding material flow path 62 is introduced into the binding material outlet chamber 63 described above and then discharged through the slot-shaped binding material outlet opening 64 of the binding material outlet chamber 63. In this case, a constant cross-sectional area of ​​the binding material flow path 6 increases the pressure inside the nozzle section 60, for example, if the binding material has high thixotropy and poor reaction.In contrast, according to the embodiment of the present invention, a buffer chamber 68 is provided in the binding material flow path 62, whereby the cross-sectional area of ​​the flow path for the binding material expands before it is introduced into the binding material outlet chamber 63, thus preventing an increase in pressure inside the nozzle section 60. This satisfactorily prevents uneven application, for example, when applying the binding material to the surfaces of the porous honeycomb segments through the nozzle section 60 of the binding material applicator. Furthermore, since the binding material can be discharged smoothly through the slot-shaped binding material outlet opening 64 of the binding material outlet chamber 63, the application width of the binding material is uniform, thus satisfactorily preventing the binding material from dripping out of the binding material outlet opening 64 of the nozzle section 60.

[0032] The buffer space 68 can be formed by dividing it with the flat spacer. The flat spacer can be an integral spacer designed such that the cross-section of the flow path expands in stages.

[0033] The nozzle section 60 of the binding material applicator according to one embodiment of the present invention further comprises, in addition to the buffer chamber 68, a buffer chamber 69, which is configured such that it extends from the buffer chamber 68 into the binding material outlet chamber 63. The buffer chambers 68 and 69 can be formed such that several flat spacers, as in the Fig. 11(a), Fig. 11(b) and Fig. 11(c) shown, stacked sequentially starting from the side of the binding material flow path 62 and finally the one in Fig. Ten flat spacers are inserted. The spacers are... Fig. In sections 11(a) to 11(b) and 11(c), a section of an opening 71, corresponding to the flow path cross-section, is enlarged stepwise in this order. Therefore, the spacer of Fig. 11(a), which adjoins the binding material outlet chamber 63 and has the smallest area of ​​the opening 71, is provided, then the spacer of Fig. 11(b) and furthermore the spacer of Fig. 11 (c) with the largest area of ​​the opening 71 in the binding material outlet chamber, thereby forming a buffer structure in which the flow path of the binding material expands stepwise. According to such a structure, the flow path of the binding material can expand until it is narrowed by the binding material outlet opening 64, so that retention of the binding material in the nozzle section 60 can be satisfactorily prevented. Furthermore, such a structure allows the buffer space 69 of the binding material outlet chamber 63 to be expanded by 200 to 550%.

[0034] The thicknesses of the in the Fig. 11(a), Fig. 11(b) and Fig. The flat spacers shown in Figure 11(c) are not particularly restricted and can, for example, each be between 1.0 and 10 mm thick. Furthermore, the thicknesses of several spacers can be the same or different.

[0035] Likewise, at least one of the flat spacers can serve as a sieve insert by having a structure comprising partitions 72 that divide the opening 71 in the form of parallel slots, as in Fig. 11(b) shown. Such a structure can enable foreign substances contained in the binding material to be trapped, thus preventing clogging of the nozzle section 60.

[0036] The material for the spacer that divides the buffer chamber 68 is not particularly restricted. For example, the spacer can be made of aluminum, iron, copper, or an alloy such as SUS, or a resin such as polyethylene, vinyl chloride, fluorocarbon resin, or polycarbonate. EXAMPLES

[0037] Examples are provided below to better understand the present invention and its advantages; however, the present invention is not limited to these examples. (Test example 1)

[0038] As test example 1, porous honeycomb segments were produced from a SiC material. The length of each porous honeycomb segment in the cell orientation direction was 141 mm.

[0039] Separately, a binding material applicator was produced, featuring a nozzle section made of a SUS material and a fluorinated resin plate with the [material / component] described in the Fig. 8 and Fig. The structure shown in Figure 9 was produced. The buffer space of the binder flow path of the nozzle section was created by stacking and dividing the material in the Fig. 11(a), Fig. 11(b) and Fig. 11(c) formed flat spacers. That is, in the binding material outlet chamber 63, starting from the side of the binding material flow path, the spacers were formed by Fig. 11(a) with the smallest area of ​​the opening 71, the spacer of Fig. 11(b) and the spacer of Fig. 11(c) with the largest area of ​​opening 71 arranged in this order and finally the one in Fig. Ten flat spacers were inserted. The thicknesses of the spacers shown in the Fig. 11(a), Fig. 11(b) and Fig. The flat spacers shown in Figure 11(c) were 5 mm, 0.5 mm and 3 mm respectively. Fig. 11(a) and Fig. 11(c) were made of fluorinated resin and the spacer of Fig. 11(b) was made of SUS304. The thickness of the in Fig. The flat spacer shown in 10 had a diameter of 1 mm and was made of fluorinated resin.

[0040] The binding material contained inorganic fibers and utilized a slurry based primarily on silicon carbide as a ceramic powder, water as a dispersion medium, and colloidal silicon dioxide as a binder. A shear stress value, indicating the viscosity of the binding material, was 240 Pa.

[0041] The binding material was applied at a constant speed (100 mm / s) from one end of the bonding surface to the other end of each porous honeycomb segment, following the direction of cell orientation within the porous honeycomb segment through the nozzle section. The application width was 37.0 cm.

[0042] After application, the application surfaces of the binding material in the porous honeycomb segments were examined, and no unevenness was observed. Furthermore, dripping of the binding material from the binding material outlet opening of the nozzle section of the binding material applicator was also satisfactorily prevented. DESCRIPTION OF REFERENCE NUMBERS 10.50 porous honeycomb segment 20 adhesive layer 30 Mounting plate 40, 100 honeycomb structure 51 cells 52 Partition wall 53 Outer perimeter wall 54 Binding material layer 60 Nozzle section 61 Binding material inlet opening 62 Binding material flow path 63 Binding material outlet space 64 Binding material outlet opening 65 bending section 66 Nozzle section base body 67 spacers 68, 69 Buffer space 70 room width 71 Opening 72 Partition wall

Claims

[1] A method for manufacturing a honeycomb structure (40, 100) for fine particle trapping filters, the honeycomb structure (40, 100) comprising a plurality of porous honeycomb structure segments (10, 50) bonded together by bonding material layers (54), each porous honeycomb structure segment (10, 50) comprising: partition walls (52) made of a SiC material, the partition walls (52) defining a plurality of cells (51) forming flow paths for a fluid, each of the cells (51) extending from an inlet end face, which is an end face on the fluid inlet side, to a fluid outlet end face, which is an end face on the fluid outlet side; and comprising an outer peripheral wall (53) located at the outermost periphery, the method comprising: joining each of the porous honeycomb segments (10, 50) via the bonding material layers (54) by applying a bonding material between bonding surfaces of each of the porous honeycomb segments (10, 50) through a nozzle portion of a bonding material applicator, wherein the nozzle portion (60) of the binding material applicator: a binding material inlet opening (61); a binding material outlet chamber (63) with a slot-shaped binding material outlet opening (64) for discharging an introduced binding material; and a binding material flow path (62) with a curved section through which the binding material passes from the binding material inlet opening (61) to the binding material outlet space (63), and wherein the binding material flow path (62) of the nozzle section (60) comprises a buffer space (68, 69) which is formed such that a flow path cross section expands gradually towards the binding material outlet space (63) on a downstream side of the bent section. [2] A method for manufacturing the honeycomb structure according to claim 1, wherein the buffer space (68, 69) is formed to extend into the binder material outlet space (63). [3] A method for manufacturing the honeycomb structure according to claim 1 or 2, wherein the binder material outlet space (63) is formed to expand the flow path cross section of the binder material from the introduction of the binder material from the binder material flow path (62) to the discharge through the binder material outlet port (64). [4] A method for manufacturing the honeycomb structure according to any one of claims 1 to 3, wherein the binder material outlet space (63) is formed by dividing with a flat spacer (67). [5] A method for manufacturing the honeycomb structure according to any one of claims 1 to 4, wherein the buffer space (68, 69) is formed by dividing with a flat spacer (67). [6] A method for manufacturing the honeycomb structure according to claim 5, wherein the buffer space (68, 69) is formed by dividing with a plurality of stacked flat spacers (67). [7] A method for manufacturing the honeycomb structure according to claim 6, wherein the cross section of the flow path of the buffer space (68, 69) shared with the plurality of flat spacers (67) becomes larger as it approaches the binder material outlet space (63). [8] A method for producing the honeycomb structure according to claim 6 or 7, wherein at least one of the plurality of flat spacers (67) also serves as a screen insert.

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