JP5331635B2 - Method for manufacturing plugged honeycomb structure - Google Patents

Description

  The present invention relates to a method for manufacturing a plugged honeycomb structure. More specifically, the present invention relates to a method for manufacturing a plugged honeycomb structure that can be used for a filter such as a diesel particulate filter and in which predetermined cells are sealed at an end face.

  A ceramic filter is used as a dust collection filter typified by a diesel particulate filter (DPF). This ceramic filter has a number of cells that are partitioned by partition walls to serve as fluid flow paths, and only one end of each cell is plugged by plugging. It has been known. Further, some plugged honeycomb structures have a checkered pattern in which end plugs are not continuously arranged.

  Since the plugging is arranged in a checkered pattern or the like in this way, the exhaust gas flowing in from one end face and exhausted from the other end face always has partition walls in the middle of flowing through the plugged honeycomb structure. pass. As a result, the plugged honeycomb structure can capture the particulates contained in the exhaust gas while allowing the exhaust gas flowing in from one end face to pass through the partition walls, remove the particulates, and discharge the purified gas.

  The arrangement of plugging, which is the key to the filter function of the plugged honeycomb structure, is performed by a step of filling plugging material into the end portions of predetermined cells. The plugging material is usually filled by immersing the end face of the honeycomb structure in the plugging material (see Patent Document 1). At this time, a mask is applied to the opening at the cell end not filled with the plugging material, and the plugging material is filled into the predetermined cell end.

  In addition, the filling of the plugging material is completed by supplying the plugging material into the cell and then separating the plugging material inside the cell from the plugging material outside the cell.

  However, in the prior art, the following two phenomena occur, and the sealing of the cell edge with the plugging material becomes incomplete.

  First, when the plugging material inside the cell and the plugging material outside the cell are separated, the plugging material inside the cell is pulled out to the outside of the cell along with the movement of the plugging material outside the cell. Incomplete filling of the sealing material. In order to cope with this, there are techniques described in Patent Documents 2 to 4 that forcibly cut the continuity between the plugging material outside the cell and the plugging material inside the cell.

  In Patent Documents 2 and 3, the inside of the cell is filled by sliding the edge of the storage container along the end face after immersing the end face of the honeycomb structure in the plugging material accommodated in the storage container. A method for manufacturing a plugged honeycomb structure in which the plugging material and the plugging material outside the cells are forcibly separated is disclosed.

  Further, in Patent Document 4, after immersing one end face of the honeycomb structure in the plugging material, air is supplied between the end face of the honeycomb structure and the plugging material outside the cell to form an air layer. A method of manufacturing a plugged honeycomb structure to be formed is disclosed. In this manufacturing method, the air layer forcibly cuts off the continuity between the plugging material inside the cell and the plugging material outside the cell.

  Next, even if the plugging material is once filled to close the cell edge, inward or outward pressure is applied to the plugging material along the cell penetration direction, and the cell edge is filled. Holes that allow the inside and outside of the cell to pass through are formed in the plugging material.

  Patent Document 5 discloses a method for manufacturing a plugged honeycomb structure, in which one end face of a honeycomb structure is immersed in a plugging material, and the cell end on the other end face side is opened. It is disclosed. As a result, the pressure repelling the inflow of the plugging material into the cell end is reduced, and the plugging material can easily flow into the cell end.

Japanese Patent Laid-Open No. 2001-300922 JP 2006-272183 A JP-A-2004-290766 JP 2004-25098 A JP 2008-55345 A

  However, in recent years, there is a tendency to reduce the porosity of the ceramic honeycomb structure in order to manufacture a DPF having high strength and high durability, or the honeycomb structure tends to be downsized as a DPF for a small vehicle. The technology of 5 cannot cope. This is because in a honeycomb structure having a reduced size or a reduced porosity, the pressure applied to the plugging material filled in the cell end portion to be discharged out of the cell is increased, and the plugging material filling itself In addition, even if the cell ends are filled, a hole that allows the inside and outside of the cell to pass through is formed in the plugging material.

  In the manufacturing method of patent document 5, since the process of removing the mask provided in the cell edge part on the opposite side to the side which immerses a plugging material is added, there exists a difficulty in productivity. Further, the manufacturing method of Patent Document 5 is premised on pressure leakage from the partition walls, and is not effective in the honeycomb structure having a reduced porosity as described above.

  In view of the above problems, an object of the present invention is to provide a plugging material in which a cell end portion of a honeycomb structure is filled with a plugging material so that the end portion of the cell can be sealed without communication between the inside and outside of the cell. An object of the present invention is to provide a method for manufacturing a stationary honeycomb structure.

  In order to solve the above-mentioned problems, the present inventors diligently studied the process of filling the plugging material into the cell end portion of the honeycomb structure, and completed the present invention. That is, according to the present invention, the following method for manufacturing a plugged honeycomb structure is provided.

[1] For a honeycomb structure having a porous partition wall and a plurality of cells penetrating from one end surface to the other end surface by the partition wall, the eyes on the one end surface and / or the other end surface The injection hole center of gravity, which has an injection hole formed so that 10 to 60% of the area of the opening of the cell is opened in the opening of the cell to be sealed, is the center of gravity of the injection hole. A masking step including a mask in which the injection hole is formed so as to be shifted with respect to a cell opening center of gravity which is a center of gravity of the opening of the cell, and a plugging material having fluidity is provided inside the cell. A plugging material filling step of supplying a plugging material to the inside of the cell from the injection hole while generating a repulsive pressure that is a pressure toward the opening.

[2] The method for manufacturing a plugged honeycomb structure according to [1], wherein the masking step includes providing the mask having the injection hole formed so as not to include the center of gravity of the cell opening.

[3] The eye according to [1] or [2], wherein the masking step includes providing the mask having the injection hole formed so that 20 to 50% of the area of the opening of the cell is opened. A method for manufacturing a sealed honeycomb structure.

[4] In the masking step, the mask having the injection hole formed so that the ratio of the length in the horizontal axis direction to the length in the vertical axis direction of the injection hole is 2.0 to 4.0. The method for manufacturing a plugged honeycomb structure according to any one of [1] to [3].

[5] The plugging material filling step is performed by holding the honeycomb structure in a state where the center of gravity of the injection hole is above the center of gravity of the cell opening. The manufacturing method of the plugged honeycomb structure as described.

[6] The [1] to [5], wherein the plugging material filling step is performed by holding the honeycomb structure so that a penetration direction of the cells from the one end face toward the other end face is horizontal. ] The manufacturing method of the plugged honeycomb structure in any one of.

[7] In the plugging material filling step, after the plugging material is supplied to the inside of the cell, the plugging material outside the cell is perpendicular to the penetrating direction with the mask interposed therebetween. The plugged honeycomb structure according to any one of [1] to [6], wherein the plugged material outside the cell is separated from the plugged material inside the cell. Body manufacturing method.

[8] The method for manufacturing a plugged honeycomb structure according to any one of [1] to [7], wherein the plugging material has a viscosity of 100 to 700 dPa · s.

  According to the method for manufacturing a plugged honeycomb structure of the present invention, the plugging material can be filled in the cell end portion of the honeycomb structure so that the end portion of the cell can be plugged without allowing the inside and outside of the cell to communicate.

It is a perspective view of a honeycomb structure. FIG. 2 is a partial cross-sectional view of a honeycomb structure taken along a line A-A ′ in FIG. 1. It is a perspective view of a plugged honeycomb structure. FIG. 2 is a view for illustrating an embodiment of a method for manufacturing a plugged honeycomb structure of the present invention, and illustrating how a plugging material is supplied from an injection hole into a cell. FIG. 5 is a diagram for illustrating an embodiment of a method for manufacturing a plugged honeycomb structure of the present invention in a step subsequent to FIG. 4 and illustrating a state in which a plugging material is held while being filled in a cell end portion. is there. It is a top view of the opening part of the cell provided with the mask which has the injection hole whose cell opening gravity center is not contained in the inside of an injection hole. It is a top view of the opening part of the cell provided with the mask which has the injection hole in which the cell opening centroid is included in the inside of the injection hole and the injection hole centroid is shifted from the cell opening centroid. It is a figure for demonstrating one Embodiment of the manufacturing method of the plugged honeycomb structure of this invention, and is a figure showing a mode that the mask which does not have an injection hole is provided in the both end surfaces of the honeycomb structure. . FIG. 9 is a diagram illustrating a process following FIG. 8 and illustrating a state in which injection holes are formed in masks provided on both end faces of the honeycomb structure. 9 represents a step following FIG. 9, and both end faces of the honeycomb structure held so that the penetration direction is horizontal are immersed in the plugging material accommodated in the storage container, so that the plugging material is placed inside the cell. It is a figure for demonstrating a mode that it supplies. 10 represents the process following FIG. 10, in which a part of the side wall is divided, and the end part of the divided side wall is slid on the end face of the honeycomb structure and moved downward while filling the plugging material outside the cell and the cell end part. It is a figure for demonstrating a mode that the made plugging material is isolate | separated.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the following embodiments, and changes, modifications, and improvements can be added without departing from the scope of the present invention.

  The method for manufacturing a plugged honeycomb structure of the present invention (hereinafter referred to as “the manufacturing method of the present invention”) is characterized by a method of filling a plugging material in a cell end portion of the honeycomb structure. First, prior to the description of the manufacturing method of the present invention, the honeycomb structure and the names of each part of the honeycomb structure will be described.

1. Honeycomb structure:
FIG. 1 shows an example of the honeycomb structure 1 in a perspective view. FIG. 2 is a cross-sectional view of the honeycomb structure 1 in the AA ′ cross section shown in FIG. The honeycomb structure 1 has porous partition walls 2, and a plurality of cells 3 penetrating from one end face 62 to the other end face 63 are partitioned by the partition walls 2.

  In the manufacture of a honeycomb structure made of ceramics used for DPF or the like, a kneaded body made of ceramic powder is formed into a honeycomb shape to form a formed body, and then the formed body is fired to obtain a fired body. The honeycomb structure referred to in the present specification corresponds to both the above-described formed body and fired body.

  In the case of the honeycomb structure 1 mainly composed of ceramics, the material is not particularly limited, but from the viewpoint of strength, heat resistance, corrosion resistance and the like, silicon carbide, silicon-silicon carbide based composite material, silicon nitride, alumina, mullite, Cordierite, aluminum titanate, silicon carbide-cordierite composite material, lithium aluminum silicate, or aluminum titanate is preferable. Among these, silicon carbide or silicon-silicon carbide based composite material is more preferable.

  Referring to FIG. 2, in this specification, a portion where the cell is open on the end face 4 of the honeycomb structure 1, that is, the end of the cell 3 is referred to as an opening 5. Further, the direction in which the cells 3 penetrate in the honeycomb structure 1 is referred to as a penetration direction 10, and the penetration direction 10 may be used for convenience when describing the posture of the honeycomb structure 1.

  When the cell end portion 7 of the honeycomb structure 1 shown in FIG. 1 is filled with the plugging material by the manufacturing method of the present invention, the plugging 64 in which the plugging 64 as shown in the perspective view of FIG. A stationary honeycomb structure 61 is obtained. In FIG. 3, when the end face 4 of the honeycomb structure 1 is viewed from the front, the plugging 64 is shown to have a checkered pattern. The manufacturing method of the present invention is not limited to the method of arranging the pluggings 64 in such a checkered pattern, and the manufacturing method of the present invention can arrange the pluggings 64 in any distribution manner as long as the pluggings 64 are arranged at the cell end 7. It can also be applied to.

2. Basic embodiment of a method for manufacturing a plugged honeycomb structure of the present invention:
In this description, for the sake of convenience, a schematic diagram in which one cell 3 and a partition wall 2 that forms the cell 3 are extracted and simplified is used. 4 and 5 are sectional views along the penetration direction 10 of the cell 3 and the partition wall 2 that defines the cell 3, and according to an embodiment of the manufacturing method of the present invention, the plugging material 31 is formed at the cell end 7. It shows how it is being supplied.

  The manufacturing method of the present invention includes a mask 11 having an injection hole 12 in the opening 5 of the cell 3, and supplies a plugging material 31 having fluidity into the cell 3 from the injection hole 12, thereby 7 is a method of filling the plugging material 31 with a masking step and a plugging material filling step, which will be described below.

2-1. Masking process:
The masking step in the manufacturing method of the present invention is a step including a mask 11 having an injection hole 12 in the opening 5 of the cell 3.

  6 and 7 represent the opening 5 of the cell 3 provided with a mask 11 having an injection hole 12 by a masking process. In these drawings, the end surface 4 of the honeycomb structure 1 is viewed from the penetration direction 10.

  In the mask 11 provided in the opening 55 by the masking process, the injection hole centroid 13 is shifted from the cell opening centroid 9.

  6 shows a form in which the cell opening centroid 9 is outside the injection hole 12, and FIG. 7 shows a form in which the cell opening centroid 9 is included in the injection hole 12.

2-1-1. Injection hole:
The injection hole 12 is a hole in the mask 11 provided in the opening 5 of the cell 3 and is formed so that the plugging material 31 can be supplied from the outside of the cell 3 to the inside of the cell 3.

  The area of the injection hole 12 corresponds to 10 to 60% of the area of the opening 5 of one cell 3. That is, in the opening 5, the plugging material 31 is supplied from the 10 to 60% portion in the area to the inside of the cell 3, and the remaining 40 to 90% in the area of the opening 5 is blocked. .

2-1-1-1. Definition of injection hole centroid and cell opening centroid and their positional relationship:
Referring to FIG. 4, when a flat film-like mask 11 is provided for the honeycomb structure 1 having a flat end face 4 perpendicular to the penetration direction 10, the injection hole center of gravity 13 is a plan view of the injection hole 12. The cell opening center of gravity 9 is determined as the center of gravity of the plane figure of the opening 5. In this case, since the opening 5 and the injection hole 12 are on the same plane, the deviation between the injection hole centroid 13 and the cell opening centroid 9 can be determined as it is.

  The honeycomb structure 1 may have an inclined structure in which a part of the end face 4 deviates from a plane perpendicular to the penetrating direction 10, and the mask 11 may have a curved shape instead of being flat. In the case of such an irregular form, in consideration of the fact that pressure along the penetration direction 10 is basically applied to the plugging material 31 filled in the cell end 7, the injection hole center of gravity is as follows: 13 and the cell opening center of gravity 9 and the positional relationship between them.

  In the case of the above-described irregular form, the injection hole center of gravity 13 is determined as the center of gravity of a plane figure obtained by projecting the injection hole 12 in the penetration direction 10 with respect to the projection plane that is a plane perpendicular to the penetration direction 10.

  Further, in the case of the above irregular form, the cell opening centroid 9 is determined as the centroid of the plane figure obtained by projecting the opening 5 in the penetration direction 10 with respect to the same projection plane as that obtained the injection hole centroid 13. .

  Therefore, when the mask 11 or the opening 5 has an irregular shape, the deviation between the injection hole centroid 13 and the cell opening centroid 9 determined on the same projection plane by the above-described method is determined.

2-1-2. Mask placement method:
As a method for disposing the mask 11, it is only necessary that the opening 5 is provided with the mask 11 having the injection hole 12 having the above-described form.

  8 and 9 show an embodiment in which the injection hole 12 is formed after the opening 5 is covered with the mask 11 having no hole. Specifically, FIG. 8 shows a longitudinal section along the penetration direction 10 of the honeycomb structure 1, and the entire end faces 4 on both sides of the honeycomb structure 1 are both covered with a mask 11 having no holes, The opening 5 is closed. FIG. 9 shows a state in which the injection hole 12 is formed in the mask 11 covering the predetermined opening 5 after the mask 11 having no holes is provided on both end faces 4 as shown in FIG.

  Alternatively, although not shown, a mask 11 in which holes serving as the injection holes 12 are formed in advance may be prepared, and the mask 11 may be provided in the opening 5 so as to have the features of the present invention.

2-2. Plugging material filling process:
Referring to FIG. 4, the plugging material filling step in the manufacturing method of the present invention is performed by supplying a flowable plugging material 13 from the injection hole 12 to the inside of the cell 3. 7 is a step of filling the plugging material 31 with 7.

2-2-1. Plugging material:
Any material can be used as the plugging material 31 used in the plugging process as long as it has fluidity and can seal the cell end 7. The specific plugging material 31 is prepared by mixing a ceramic powder and a dispersion medium such as water in which the ceramic powder is dispersed, for example, as used for plugging a conventional plugged honeycomb structure. Can be mentioned.

  When plugging the honeycomb structure 1 containing ceramic as a main component, it is preferable to use a ceramic slurry made of the same raw material as the raw material of the honeycomb structure as the plugging material 31. As a result, when the plugging material 31 is filled in the cell end portion 7 and fired, the thermal expansion coefficient between the honeycomb structure 1 and the plugging material 31 is the same, and the highly durable plugging is achieved. A stationary honeycomb structure 61 can be obtained.

2-2-2. Conditions that produce repulsive pressure:
In the plugging material filling step, when the plugging material 31 is supplied from the injection hole 12, as shown by the white arrow in FIG. 4, the repulsion is a pressure from the inside of the cell 3 toward the opening 5. Make sure pressure is generated.

  For example, as shown in FIG. 4, the opening 5 on the side opposite to the side where the plugging material 31 is supplied is closed with a mask 20 or the like so that the repulsive pressure is generated. There is a method of utilizing the repulsive force of the gas in the cell 3 that contracts by being supplied into the cell 3.

  Alternatively, although not shown here, plugging supplied to the inside of the cell 3 by sending a gas or liquid such as air into the cell from the opening 5 on the side opposite to the side on which the plugging material 31 is supplied. A repulsive pressure applied to the material 31 may be generated.

2-2-3. Method for supplying plugging material into the cell:
Any method can be used for supplying the plugging material 31 into the cell 3 from the injection hole 12 as long as the plugging material 31 can be supplied into the cell 3 against the repulsive pressure generated inside the cell 3. Can be used.

  The method of supplying the plugging material 31 into the cell 3 from the injection hole 12 is a method of continuously supplying the plugging material 31 into the cell 3 or the plugging material 31 is interrupted intermittently. Any of the methods of supplying to the inside may be used.

  For example, as shown in Patent Document 4, a method of pressing the plugging material 31 accommodated in a dish-shaped storage container against the end surface 4 of the honeycomb structure 1 and press-fitting the plugging material 31 into the cell 3. May be adopted.

  Alternatively, as in the method disclosed in Japanese Patent Application Laid-Open No. 2009-40046 by the applicant, a plugging device having a pressure member that helps supply the plugging material 31 to the inside of the cell 3 is used. The material 31 may be supplied into the cell 3.

2-3. Operation in the basic embodiment of the production method of the present invention:
FIG. 5 shows a state after the plugging material 31 is supplied to the cell end 7 by the process shown in FIG. As can be understood from the transition from FIG. 4 to FIG. 5, when the plugging material 31 is supplied to the cell end portion 7 by the manufacturing method of the present invention, the repulsive pressure is applied to the plugging material 31. A situation occurs in which the propulsive force of the plugging material 31 from the opening 5 side toward the cell center 6 antagonizes. In addition, due to the fluidity of the plugging material 31, the plugging material 31 spreads in the direction perpendicular to the penetrating direction 10 and spreads over the entire cell end 7, or inside and outside the cell 3. It is filled so that it can be shut off.

  As can be understood from FIG. 5, in the manufacturing method of the present invention, once the plugging material 31 is supplied to the cell end portion 7, it is supported by the inner surface 14 of the mask 11 and repulsive pressure is applied. However, it is not discharged outside the cell 3.

  Since the porous partition wall 2 absorbs the moisture of the plugging material 31 and the plugging material 31 is solidified from the vicinity of the partition wall 2 toward the center portion, the plugging material at the center of gravity 9 of the cell opening 31 is the slowest to solidify.

  Moreover, even if it considers that the plugging material 31 has viscosity at the injection hole center of gravity 13, it is difficult to prevent the discharge and deformation of the plugging material 31 from the vicinity.

  In the manufacturing method of the present invention, since the cell opening centroid 9 and the injection hole centroid 13 are deviated, once the plugging material 31 is filled in the cell end portion 7, the plugging material 31 is discharged or deformed. Due to the action of the mask 11 for suppressing the deformation, it is easily held without being deformed until it is solidified.

  While having the configuration of the basic embodiment of the manufacturing method of the present invention described so far, it is also possible to apply an embodiment provided with a masking step or a plugging material filling step as described below. is there.

3. Masking process:
3-1. Embodiment in which a mask is provided in which the injection hole does not include the cell opening center of gravity:
As shown in FIG. 6, the masking step preferably includes a mask 11 having an injection hole 12 formed so as not to include the cell opening center of gravity 9 therein.

  In this embodiment, when the cell opening centroid 9 and the injection hole centroid 13 are determined by the above irregular method, that is, when the injection hole centroid 13 and the cell opening centroid 9 are determined on the projection plane, the projection is performed from the injection hole 12. This means that the cell opening centroid 9 is not included in the figure projected on the plane.

  In the embodiment in which the injection hole 12 does not include the cell opening center of gravity 9, since the inner surface 14 of the mask 11 covers the plugging material 31 near the cell opening center of gravity 9 that is slowly solidified, the plugging material 31 is outside the cell 3. Is more difficult to be exhaled. Further, in this embodiment, the plugging material 31 is reliably prevented from being dented from the vicinity of the center of gravity 9 of the cell opening and coming into the interior before the plugging material 31 is completely solidified. No holes are formed in 31.

3-2. Embodiment comprising an injection hole in which 20-50% of the opening area is opened:
The masking step preferably includes a mask 11 having an injection hole 12 formed so that 20 to 50% of the area of the opening 5 of the cell 3 is opened. From such an injection hole 12, the plugging material 31 is easily supplied into the cell 3, and the plugging material 31 once filled in the cell end portion 7 is difficult to be discharged out of the cell 3.

3-3. Embodiment including an injection hole formed such that a ratio of a length in a horizontal axis direction to a length in a vertical axis direction of the injection hole is 2.0 to 4.0:
Referring to FIG. 6, in the masking step, the injection hole 12 is formed such that the ratio of the length 21 in the horizontal axis direction to the length 22 in the vertical axis direction of the injection hole 12 is 2.0 to 4.0. A mask 11 having holes 12 is preferably provided. From the injection hole 12 having such a configuration, the plugging material 31 is easily supplied into the cell 3, and the plugging material 31 once filled in the cell end 7 is difficult to be discharged out of the cell 3.

4). Plugging material filling process:
4-1. Embodiment in which the honeycomb structure is held in a state where the center of gravity of the injection hole is above the center of gravity of the cell opening:
As shown in FIG. 4, the plugging and filling step is preferably performed while holding the honeycomb structure 1 in a state where the injection hole center of gravity 13 is above the cell opening center of gravity 9. In this embodiment, the plugging material 31 supplied into the cell 3 receives the action of gravity in addition to the repulsive pressure. Therefore, in this embodiment, the plugging material 31 tends to spread over the entire cell end portion 7.

4-2. Embodiment in which the honeycomb structure is held so that the cell penetration direction is horizontal:
As shown in FIG. 4, the plugging and filling step is preferably performed by holding the honeycomb structure 1 so that the penetration direction 10 of the cells 3 is horizontal. In such a form, as illustrated in FIG. 10, it becomes easy to simultaneously fill the plugging material 31 with respect to the end faces 4 on both sides of the honeycomb structure 1, and the plugging material 31 on the both end faces 4 can be easily filled. Supply conditions can be the same.

4-3. Embodiment in which the plugging material outside the cell is moved perpendicularly to the penetration direction after continuously supplying the plugging material to the inside of the cell:
In the plugging material filling step, after the plugging material 31 is supplied to the inside of the cell 3, the plugging material 31 a outside the cell 3 is moved perpendicularly with respect to the penetration direction 10 across the mask 11, 3 The plugging material 31a outside and the plugging material 31b inside the cell 3 are preferably separated. A specific example of this embodiment will be described below with reference to FIGS.

  FIG. 10 is a longitudinal sectional view of the honeycomb structure 1 provided with the mask 11 and the dish-shaped storage container 41 containing the plugging material 31 along the penetration direction 10. This figure shows a state in which the plugging material 31 accommodated in the dish-shaped storage container 41 is pressed against the end face 4 of the honeycomb structure 1 and the plugging material 31 is continuously pressed into the cells 3. Represents.

  The storage container 41 shown in FIG. 10 is comprised from two parts so that a part of side wall 43 may isolate | separate. More specifically, the portion where the side wall 43 is partially separated includes a configuration in which an auxiliary wall 48 is added to the outside of the divided side wall 50 on the side where the plugging material 31 is accommodated. Further, in the side wall 43 with the auxiliary wall 48 added, the position of the tip 49 of the separation side wall 50 is in the middle part of the side wall 43 with the auxiliary wall 48 attached.

  Note that the position of the tip 49 of the separation side wall 50 is such that the end surface 4 of the honeycomb structure 1 is located on the inner bottom than the liquid level of the plugging material 31 when pressed against the plugging material 31 accommodated in the storage container 41. Preferably on the 42 side. Thereby, the separation side wall 50 and the auxiliary wall 48 can be separated while the end surface 4 of the honeycomb structure 1 is pressed against the plugging material 31.

  FIG. 11 shows a state where the plugging material 31 is press-fitted into the cell 3 by the method shown in FIG. 10 and then separated into the separation side wall 50 and the auxiliary side wall 48. Since there is the tip 49 of the separation side wall 50 at the position as described above, the separation side wall 50 separated from the auxiliary side wall 48 crosses over the end surface 4 without being caught by the outer peripheral wall of the honeycomb structure 1. It can move perpendicular to the penetration direction 10.

  At this time, it is preferable to move the front end portion 49 of the separation side wall 50 so as to slide on the end face 4 of the honeycomb structure 1 (see FIG. 11). The plugging material 31a outside the cell 3 and the plugging material 31b inside the cell can be forcibly separated by the tip 49 of the separation side wall 50, and the extra plugging remaining on the end face 4 The material 31 can also be scraped off.

  At this time, either the storage container 41 from which the auxiliary wall 48 is cut off or the honeycomb structure 1 may be moved, or both may be moved.

  Furthermore, it is more preferable that the plugging material 31a outside the cell 3 is moved along the direction from the injection hole center of gravity 13 to the cell opening center of gravity 9. By such relative movement of the plugging material 31a, the edge of the injection hole 12 easily acts like a blade, and the plugging material 31a outside the cell 3 is separated from the mask 3 with the mask 11 interposed therebetween. Can be smoothly separated from the plugging material 31b.

4-4. Embodiment in which the plugging material 31 is filled simultaneously from both end faces of the honeycomb structure:
In the plugging and filling step, it is preferable that the plugging material 31 is simultaneously supplied from the injection holes 12 on both the one end face 62 and the other end face 63. This increases productivity.

  When the plugging material 31 is a ceramic slurry, the honeycomb structure 1 in which the plugging material 31 is filled in the cell end portions 7 can be fired after the plugging material filling step.

  The viscosity of the plugging material 31 is 100 from the viewpoint of suppressing incomplete plugging such as the formation of holes in the plugging material 31 filled in the cell end 7 and reducing variation in the plugging depth. It is preferably ˜700 dPa · s, more preferably 200 to 600 dPa · s. When the viscosity of the plugging material 31 is 100 dPa · s or more, the plugging material 31 is reliably prevented from being filled more deeply than necessary or dripping into the cell 3. It will not be discharged outside the cell 3. Moreover, when the viscosity of the plugging material 31 is 700 dPa · s or less, the plugging material 31 can be reliably filled from the end face 4 to a desired depth. In addition, the viscosity of the plugging material 31 here is measured according to JIS K7117-1 using a single cylindrical rotational viscometer.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail based on an Example, this invention is not limited to these Examples.

(Examples 1-17, Comparative Examples 1-6)
(1) Honeycomb structure:
A raw material powder mainly composed of silicon carbide powder was kneaded to form a clay, and this was extruded to produce a honeycomb-shaped formed body. After drying this molded body, the both end surfaces of the molded body were cut into smooth surfaces, whereby a honeycomb structure 1 filled with the plugging material 31 was obtained. In this honeycomb structure 1, the cell 3 is composed of a cell 3 having a large cell diameter and a cell 3 having a small cell diameter. Specifically, the cell 3 having a large cell diameter is formed to be an octagon having a distance between opposite sides of 1.99 mm, and the cell having a small cell diameter is formed to be a square having a side of 1.27 mm. The cells 3 having small cell diameters were formed so as to be alternately arranged. Moreover, the honeycomb structure 1 manufactured here is a segment having an outer dimension of 36.9 mm × 36.9 mm × 127 mm, a partition wall thickness of 0.38 mm, and a cell density of 160 cells / inch ² .

(2) Masking process:
An adhesive film to be the mask 11 was attached to the entire end face 4 on both sides of the honeycomb structure 1 described above. In sticking the adhesive film, an adhesive was applied to one surface of a polyester film, and then the film surface to which the adhesive was applied was adhered to the end face 4 of the honeycomb structure 1 (see FIG. 8).

  Subsequently, the position of the cell 3 was calculated by image processing by a method usually used in a method for manufacturing a plugged honeycomb structure. Furthermore, the coordinate value corresponding to the position of the opening 5 of the cell 3 to be sealed, and the coordinate values of the inside and the contour of the injection hole 12 were calculated. Based on these coordinate values, the injection hole 12 was formed by irradiating only the coordinate value of the portion where the injection hole 12 was to be formed.

  In one end face 62 of the honeycomb structure 1, the injection hole 12 is formed only in the adhesive film covering the opening 5 of the large cell diameter cell 3, and in the other end face 63, the opening of the small cell diameter cell 3 is formed. The injection hole 12 was formed in the adhesive film covering the part 5. The injection hole 12 was formed so that its shape was an ellipse or a quadrangle. See FIGS. 6 and 7 for the elliptical injection hole 12.

  In Examples 1 to 17 and Comparative Examples 1 to 6, the form of the injection hole 12 of the mask 11 provided in the opening 5 of the cell 3 having a large cell diameter on one end face 62 is shown in Table 1. In addition, “contains the center of gravity” described in Table 1 refers to the presence of the center of gravity when the cell opening center of gravity 9 is inside the injection hole 12. The “opening area ratio” shown in Table 1 is a percentage ratio (%) of the area of the injection hole 12 to the area of the opening 5 of the cell 3.

(3) Plugging material filling step:
The plugging material 31 was prepared as a ceramic slurry having the same component as the honeycomb structure 1 and by adjusting the kind and amount of the binder to be added so as to have a viscosity of 50 to 800 dPa · s (Table 1). The viscosity was measured according to JIS K 7117-1 using a single cylindrical rotational viscometer.

  The plugging material 31 was supplied using a dish-shaped storage container 41 in which a part of the side wall 43 shown in FIGS. As shown in FIG. 10, the honeycomb structure 1 is held so that the penetration direction 10 is horizontal, and the liquid level of the plugging material 31 accommodated in the storage container 41 is substantially perpendicular to the penetration direction 10. After that, the distance between the inner bottom portion 42 of the storage container 41 and the end face 4 of the honeycomb structure 1 is pressed at a pressure of 0.2 MPa so as to shrink along the horizontal direction, thereby plugging the end face 4 of the honeycomb structure 1. It was immersed in the material 31. The time (press-in time) for immersing the end face 4 of the honeycomb structure 1 in the plugging material 31 was 1 second. The total amount of slurry filled in all large cells (diameter 1.99 mm) on one end face 62 was 11 g.

  After the plugging material supply 31, in Examples 1-9, 11-17 and Comparative Examples 1, 2, 4-6, the plugging material 31a outside the cell 3 and the plugging material 31b inside the cell 3 As shown in FIG. 11, the separation is performed by separating the auxiliary side wall 48 and the separation partition wall 50, and sliding the tip 49 of the separation partition wall 50 downward on the end face 4 of the honeycomb structure 1, that is, with respect to the penetration direction 10. And moved vertically ("Vertical" in Table 1).

  In Example 10 and Comparative Example 3, the storage container 41 is moved in the horizontal direction and separated from the honeycomb structure 1, thereby separating the plugging material 31 a outside the cell 3 and the plugging material 31 b inside the cell 3. ("Horizontal" in Table 1, not shown).

  As described above, the cell end portion 7 of the honeycomb structure 1 was filled with the plugging material 31, and after the plugging material 31 was dried and solidified, the evaluation described below was performed.

(4) Evaluation:
About the plugging material 31 filled in the cell end portion 7 of the cell 3 having a large cell diameter, the following three items are present: presence or absence of plugging omission, average value of plugging depth, and variation in plugging depth. The results are shown in Table 2. As for the presence or absence of plugging, the plugging material 31 flows out from the cell end 7 onto the end face 4 of the honeycomb structure 1 immediately after filling the cell end 7 or the plugging material 31 is insufficient. The determination was made based on whether or not a hole passing through the inside of the cell 3 and the outside of the cell 3 was formed in the plugging material 31 filled in the cell end 7 due to the filling of the amount. As the average value of the plugging depth, seven large cell diameters arbitrarily selected from the end face 4 of one honeycomb structure 1 were selected, and the cells 3 having these seven large cell diameters were filled. The average value of the depth of the plugging material 31 was calculated. The plugging depth is such that the metal rod is inserted into the cell 3 from the cell end 7 opposite to the side filled with the plugging material 31 toward the cell end 7 filled with the plugging material 31. Insertion was performed by subtracting the insertion length of the metal rod from the total length in the penetration direction 10 of the cell 3. The plugging depth variation was obtained by calculating the standard deviation σ with respect to the average value of the above-mentioned plugging depth.

  In Examples 1 to 17, no plugging was lost. On the other hand, in Comparative Examples 1 to 6, all occluded plugging occurred. Therefore, in Examples 1 to 17 belonging to the technical scope of the manufacturing method of the present invention, the cell end portion 7 of the honeycomb structure 1 is focused so that the cell end portion can be sealed without the inside and outside of the cell 3 being communicated. The sealing material 31 could be filled.

  From the evaluation results of Examples 1 to 4, 10 to 12, 15, and 16, the opening area ratio of the injection hole 12 is set to 20 to 50%, and the ratio of the length in the horizontal axis direction to the length in the vertical axis direction is set to 2. By setting it to 0-4.0, variation in plugging depth was suppressed (1.0 mm or less), and quality could be improved. When this ratio deviates from 2.0 to 4.0, even though plugging omission can be suppressed, it becomes difficult for the plugging material 31 to enter the cell 3, and the variation in the plugging depth becomes large ( Tables 1, 2).

  Further, Example 2 and Example 10, and Comparative Example 2 and Comparative Example 3 compare with respect to the direction of separation between the plugging material 31a outside the cell 3 and the plugging material 31b inside the cell 3. In Example 2 and Comparative Example 2, the plugging depth was deeper than in Example 10 and Comparative Example 3, which were compared with these, and the variation in the plugging depth was small (Tables 1 and 2). Therefore, the embodiment in which the direction of separation between the plugging material 31 a outside the cell 3 and the plugging material 31 b inside the cell 3 is perpendicular to the penetration direction 10 is more than the embodiment in which the separation direction is parallel to the penetration direction 10. However, the plugging material 31 was filled to an appropriate depth, and it was difficult for plugging omission and variation in the plugging depth to occur.

  Further, Example 2 and Example 11 compare whether or not the cell opening center of gravity 9 is included in the injection hole 12. In Example 2, the plugging depth was deeper than that in Example 11, and the variation in the plugging depth was small (Tables 1 and 2). Therefore, the embodiment in which the cell opening centroid 9 is not included in the injection hole 12 is filled with the plugging material 31 to an appropriate depth, compared to the embodiment in which the cell opening centroid 9 is included in the injection hole 12. It was difficult to cause omission of plugging and variations in plugging depth.

  Moreover, Examples 14-17 and Comparative Examples 5 and 6 differ only in the viscosity of the plugging material 31. Examples 15 and 16 in which the viscosity of the plugging material 31 is 200 to 600 dPa · s are plugged compared to Example 14 in which the viscosity is 100 dPa · s and Example 17 in which the viscosity is 700 dPa · s. The variation in depth was small (Tables 1 and 2). Further, in Comparative Example 5 having the same viscosity of less than 100 dPa · s, the plugging material 31 was discharged out of the cell 3 after plugging, and the plugging was lost. In Comparative Example 6 where the viscosity is greater than 700 dPa · s, plugging omission due to insufficient filling of the plugging material 31 occurred. Therefore, when the viscosity of the plugging material 31 is 100 to 700 dPa · s, the end of the cell 3 can be sealed without communication between the inside and outside of the cell, and when the viscosity is 200 to 600 dPa · s, the quality is higher. The plugged honeycomb structure was successfully manufactured.

  INDUSTRIAL APPLICABILITY The present invention can be used for a filter such as a diesel particulate filter, and can be used as a method for manufacturing a plugged honeycomb structure in which predetermined cells are sealed at an end surface.

1: honeycomb structure, 2: partition, 3: cell, 4: end face, 5: opening, 6: cell center, 7: cell end, 8: outer peripheral wall, 9: center of gravity of cell opening, 10: penetration direction, 11: mask, 12: injection hole, 13: gravity center of injection hole, 14: inner surface, 21: length in the horizontal axis direction, 22: length in the vertical axis direction, 31: plugging material, 31a: plugging Material: 31b: Plugging material, 41: Reservoir, 42: Inner bottom, 43: Side wall, 48: Supplementary side wall, 49: Tip side, 50: Divided side wall, 51: Vertical direction, 52: Up direction, 53: Downward direction, 55: Cell center direction, 56: Cell end direction, 60: Horizontal direction, 61: Plugged honeycomb structure, 62: One end face, 63: The other end face, 64: Plugged.

Claims (8)

For a honeycomb structure having a porous partition wall and a plurality of cells penetrating from one end surface to the other end surface by the partition wall,
There is an injection hole formed so that 10 to 60% of the area of the opening of the cell is opened in the opening of the cell that is scheduled to be plugged on the one end surface and / or the other end surface. And a masking step comprising a mask in which the injection hole is formed such that the injection hole centroid which is the center of gravity of the injection hole is shifted with respect to the cell opening centroid which is the center of gravity of the opening of the cell;
A plugging material filling step of supplying a plugging material having fluidity to the inside of the cell from the injection hole while generating a repulsive pressure that is a pressure directed from the inside of the cell toward the opening. A method for manufacturing a plugged honeycomb structure.   The method for manufacturing a plugged honeycomb structure according to claim 1, wherein the masking step includes providing the mask having the injection hole formed so as not to include the center of gravity of the cell opening.   The plugged honeycomb structure according to claim 1 or 2, wherein the masking step includes providing the mask having the injection hole formed so that 20 to 50% of the area of the opening of the cell is opened. Production method.   The said masking process provides the said mask which has the said injection hole formed so that the ratio of the length of the horizontal axis direction with respect to the length to the vertical axis direction of the said injection hole may be 2.0-4.0. The manufacturing method of the plugged honeycomb structure as described in any one of 1-3.   5. The plugging according to claim 1, wherein the plugging material filling step is performed by holding the honeycomb structure in a state where the center of gravity of the injection hole is above the center of gravity of the cell opening. A method for manufacturing a stationary honeycomb structure.   The plugging material filling step is performed by holding the honeycomb structure so that a penetrating direction of the cells from the one end surface toward the other end surface is horizontal. A method for producing a plugged honeycomb structure according to claim 1.   In the plugging material filling step, after the plugging material is supplied to the inside of the cell, the plugging material outside the cell is moved perpendicularly to the penetration direction with the mask interposed therebetween. The method for manufacturing a plugged honeycomb structure according to any one of claims 1 to 6, wherein the plugging material outside the cell and the plugging material inside the cell are separated. .   The method for manufacturing a plugged honeycomb structure according to any one of claims 1 to 7, wherein the plugging material has a viscosity of 100 to 700 dPa · s.

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