JPWO2009035049A1 - Manufacturing method of honeycomb filter - Google Patents

Abstract

A honeycomb formed body 100 is formed by molding a clay containing a ceramic raw material, the honeycomb formed body 100 is fired to produce a honeycomb fired body, and an outer peripheral wall of the honeycomb fired body is ground to produce a ground honeycomb fired body. A method for manufacturing a honeycomb filter in which an outer peripheral coat wall is formed on the outer periphery of a ground honeycomb fired body to produce a honeycomb filter, and the honeycomb formed body 100 during firing has a center 11 in a cross section perpendicular to the central axis direction. The direction toward the outer peripheral wall 4 along the one partition wall 2 is defined as “0 ° direction”, and the portion where the straight line 12 extending in the 0 ° direction intersects with the outer peripheral wall 4 is defined as “0 ° direction portion” 13. Manufacturing method of a honeycomb filter having a ground portion 6 in which the outer peripheral wall 4 is ground in a range of 10 to 100 mm in width including a “45 ° direction portion” 15 with respect to the “0 ° direction” of the wall 4 . Provided is a method for manufacturing a honeycomb filter capable of suppressing the occurrence of cutting when a honeycomb formed body is fired.

Description

  The present invention relates to a method for manufacturing a honeycomb filter, and more particularly, to a method for manufacturing a honeycomb filter capable of suppressing the occurrence of cutting when a honeycomb formed body is fired.

  Particulate matters and harmful substances in exhaust gas emitted from internal combustion engines such as automobile engines, construction machinery engines, and stationary machinery for industrial machinery, and other combustion equipment, etc. There is a growing need for removal. In particular, regulations regarding the removal of particulate matter (hereinafter sometimes referred to as “PM”) emitted from diesel engines tend to be strengthened worldwide, and a collection filter (diesel particulates) for removing PM -The use of a honeycomb filter has attracted attention as a filter (hereinafter sometimes referred to as "DPF"), and various systems have been proposed. The DPF is usually provided with a predetermined partition (predetermined cell) having a porous partition wall that partitions and forms a plurality of cells serving as fluid flow paths, one end of which is open and the other end is plugged. Cell) and the remaining cells (residual cells) with one end plugged and the other end opened alternately, and flow from one end where a given cell opens The collected fluid (exhaust gas) permeates through the partition walls and flows out into the remaining cells as permeated fluid, and the permeated fluid flows out from the other end where the remaining cells open, thereby collecting and removing PM in the exhaust gas. To do.

  Among such honeycomb filters, cordierite honeycomb filters are preferably used as those having excellent thermal shock resistance. As a method for manufacturing a cordierite honeycomb filter, for example, a ceramic raw material, water and the like are kneaded to prepare a clay, and the resulting clay is extruded to prepare a honeycomb molded body. A method of obtaining a honeycomb filter by firing a honeycomb fired body, grinding an outer peripheral wall of the obtained honeycomb fired body, and disposing an outer peripheral coat wall on the outer periphery (for example, Patent Document 1). reference).

When the cordierite honeycomb filter is small, it was possible to manufacture the honeycomb filter by the above-described manufacturing method. When the body is fired, there is a problem that “cut” occurs in the honeycomb fired body.
Japanese Patent No. 2925893

  For example, as shown in FIGS. 12 and 13, in one end portion 209 of the fired honeycomb fired body 200, the direction from the center 205 toward the outer peripheral wall 203 along one partition wall 202 is defined as “0 ° direction”. When the portion where the straight line 206 extending in the “0 ° direction” intersects the outer peripheral wall 203 is the “0 ° direction portion” 207, from the vicinity of the “45 ° direction portion” 210 when the “0 ° direction” is the reference, There may be a problem that a “cut” 208 occurs toward the center 205. In this specification, “cut” means that a honeycomb-shaped structure (a honeycomb molded body, a honeycomb fired body, a honeycomb filter, etc.) has an outer peripheral wall and a part of each wall as shown in FIGS. A state that is broken like a tear. Here, FIG. 12 is a plan view schematically showing a state in which cutting has occurred near the “45 ° direction portion” of one end 209 of the honeycomb fired body in the conventional method for manufacturing a honeycomb filter, FIG. 13 is a perspective view schematically showing a state in which cutting has occurred in the vicinity of a “45 ° direction portion” of one end portion of a honeycomb fired body in a conventional method for manufacturing a honeycomb filter. The honeycomb fired body shown in FIGS. 12 and 13 includes a porous partition wall 202 that partitions and forms a plurality of cells 201, and an outer peripheral wall 203 disposed on the outer periphery of the partition wall 202. The pluggings 204 are alternately formed.

  Thus, when manufacturing a large honeycomb filter, the cut 208 is likely to occur in the vicinity of the “45 ° direction portion” 210 on both end faces of the honeycomb fired body 200. It was likely to occur at the corner portion on the lower end surface side in contact with a part of the baking apparatus. Further, when the honeycomb formed body is placed in the firing apparatus, it is usually placed on the Tochi with one end face facing down, so that the lower end face at that time is a part in contact with a part of the firing apparatus. . Here, in this specification, the “corner portion” means a portion where the outer peripheral surface and the end surface intersect in the honeycomb shape.

  The present invention has been made in view of such problems of the prior art, and in the process of manufacturing a large-sized honeycomb filter, a honeycomb capable of suppressing the occurrence of breakage when firing a honeycomb formed body. A method for manufacturing a filter is provided.

  The present invention provides the following honeycomb filter manufacturing method.

[1] Molding a clay containing a ceramic raw material to produce a honeycomb formed body having porous partition walls for partitioning a plurality of cells and an outer peripheral wall disposed on the outer periphery of the partition walls; The formed body is fired to prepare a honeycomb fired body, the outer peripheral wall of the honeycomb fired body is ground to prepare a ground honeycomb fired body, and the outer peripheral coat wall is formed on the outer periphery of the ground honeycomb fired body to form a honeycomb filter. A method for manufacturing a honeycomb filter to be manufactured, wherein the honeycomb formed body at the time of firing has a cross section perpendicular to the central axis direction, and a direction from the center toward the outer peripheral wall along one partition wall is defined as a “0 ° direction”. When the portion where the straight line extending in the 0 ° direction intersects the outer peripheral wall is defined as the “0 ° direction portion”, the “45 ° direction portion” of the outer peripheral wall with reference to the “0 ° direction”. Including width 10 In the range of 300 mm, a method for manufacturing a honeycomb filter having a grinding portion outer peripheral wall has been ground.

[2] The honeycomb molded body at the time of firing further has an outer peripheral wall in a range of 10 to 100 mm in width including a “135 ° direction portion” of the outer peripheral wall with reference to the “0 ° direction”. The method for manufacturing a honeycomb filter according to [1], including a ground portion that has been ground.

[3] The honeycomb molded body at the time of firing further has an outer peripheral wall in a range of a width of 10 to 100 mm including a “225 ° direction portion” with respect to the “0 ° direction” of the outer peripheral wall. The method for manufacturing a honeycomb filter according to [1] or [2], wherein the honeycomb filter has a ground portion.

[4] The honeycomb formed body at the time of firing further has an outer peripheral wall in a range of 10 to 100 mm in width including a “315 ° direction portion” of the outer peripheral wall with respect to the “0 ° direction”. The method for manufacturing a honeycomb filter according to [3], including a ground portion that has been ground.

[5] The ground portion is formed so as to extend in the central axis direction from one end of the honeycomb formed body at the time of firing, and the length of the ground portion in the central axis direction is in the range of 5 to 20 mm. The manufacturing method of the honey-comb filter in any one of 1]-[4].

[6] One end portion of the honeycomb formed body at the time of firing having the ground portion is an end portion on the side in contact with a part of the firing apparatus when the honeycomb formed body is placed in the firing apparatus [5]. ] The manufacturing method of the honey-comb filter of description.

[7] The ground portion is formed on one end side of the honeycomb formed body at the time of firing, and the other end portion side of the honeycomb formed body at the time of firing is in the direction of the central axis from the other end portion. The honeycomb filter according to [5] or [6], wherein a ground portion is formed so as to extend in a length, and a length in a central axis direction of the ground portion formed on the other end side is in a range of 5 to 20 mm. Production method.

[8] The honeycomb filter according to any one of [1] to [7], wherein the ground portion is formed after the kneaded material is formed to produce the honeycomb formed body and before the honeycomb formed body is fired. Manufacturing method.

[9] The honeycomb filter according to any one of [1] to [4], wherein the honeycomb formed body is formed while forming the ground portion when the kneaded material is formed to form the honeycomb formed body. Production method.

  According to the method for manufacturing a honeycomb filter of the present invention, when the honeycomb formed body is fired, the honeycomb formed body having a ground portion with the outer peripheral wall ground with a predetermined width including the “45 ° direction portion” is fired. As a result, the outer peripheral wall of the “45 ° direction portion” where stress (tensile stress) is likely to concentrate is removed. Therefore, even when a large honeycomb filter is manufactured, the “45 ° direction portion of the outer peripheral wall is reduced. It is possible to suppress the occurrence of “cuts” due to the stress concentration on the outer peripheral wall during firing.

1 is a perspective view schematically showing a honeycomb formed body at the time of firing in an embodiment of a method for manufacturing a honeycomb filter of the present invention. FIG. FIG. 4 is a cross-sectional view of a honeycomb molded body at the time of firing, at a position perpendicular to the central axis direction and including a ground portion, in an embodiment of the honeycomb filter manufacturing method of the present invention. FIG. 10 is a perspective view schematically showing a honeycomb formed body at the time of firing in still another embodiment of the method for manufacturing a honeycomb filter of the present invention. FIG. 10 is a perspective view schematically showing a honeycomb formed body at the time of firing in still another embodiment of the method for manufacturing a honeycomb filter of the present invention. FIG. 10 is a perspective view schematically showing a honeycomb formed body at the time of firing in still another embodiment of the method for manufacturing a honeycomb filter of the present invention. FIG. 10 is a perspective view schematically showing a honeycomb formed body at the time of firing in still another embodiment of the method for manufacturing a honeycomb filter of the present invention. FIG. 10 is a perspective view schematically showing a honeycomb formed body at the time of firing in still another embodiment of the method for manufacturing a honeycomb filter of the present invention. FIG. 10 is a perspective view schematically showing a honeycomb formed body at the time of firing in still another embodiment of the method for manufacturing a honeycomb filter of the present invention. FIG. 10 is a perspective view schematically showing a honeycomb formed body at the time of firing in still another embodiment of the method for manufacturing a honeycomb filter of the present invention. FIG. 6 is a perspective view schematically showing a honeycomb formed body at the time of firing in another embodiment of the method for manufacturing a honeycomb filter of the present invention. FIG. 3 is a cross-sectional view of a honeycomb molded body at the time of firing at a position that is orthogonal to the central axis direction and does not include a grinding portion in the honeycomb filter manufacturing method of the present invention. FIG. 6 is a plan view schematically showing a state in which a cut occurs in the vicinity of a “45 ° direction portion” of one end portion of a honeycomb fired body in a conventional honeycomb filter manufacturing method. FIG. 6 is a perspective view schematically showing a state in which a cut has occurred in the vicinity of a “45 ° direction portion” of one end portion of a honeycomb fired body in a conventional honeycomb filter manufacturing method. FIG. 3 is a plan view schematically showing a backing plate disposed on the upstream side of a die used for forming a honeycomb formed body in the method for manufacturing a honeycomb filter of the present invention.

Explanation of symbols

2: partition, 3: cell, 4: outer peripheral wall, 5: one end (lower end), 6, 6a, 6b, 6c, 6d, 6a ′, 6b ′, 6c ′, 6d ′: ground portion, 7 : Other end, 11: center, straight line extending in 12: 0 ° direction, 13: 0 ° direction portion, 14: straight line extending in 45 ° direction, 15: 45 ° direction portion, straight line extending in 16: 135 ° direction 17: 135 ° direction portion, 18: 225 ° direction straight line, 19: 225 ° direction portion, 20: 315 ° direction straight line, 21: 315 ° direction portion, 50: Back pressing plate, 51: Projection , 100, 110, 120, 130, 140, 150, 160, 170, 180, 190: honeycomb formed body, 200: honeycomb fired body, 201: cell, 202: partition wall, 203: outer peripheral wall, 204: plugging, 205: Center, 206: 0 Directly extending in the direction of 0 ° Line, 207: 0 ° portion, 208: Cut, 209: One end, 210: 45 ° portion, W: Width, L: Length.

  BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the best mode for carrying out the present invention will be specifically described. However, the present invention is not limited to the following embodiment, and is within the scope of the gist of the present invention. Based on this knowledge, it should be understood that design changes, improvements, etc. can be made as appropriate.

  One embodiment of a method for manufacturing a honeycomb filter according to the present invention includes forming a clay containing a ceramic raw material to form a porous partition wall defining a plurality of cells and an outer peripheral wall disposed on the outer periphery of the partition wall. The honeycomb formed body is manufactured, the honeycomb formed body is fired to prepare the honeycomb fired body, the outer peripheral wall of the honeycomb fired body is ground to prepare the ground honeycomb fired body, and the outer peripheral coat wall is formed on the outer periphery of the ground honeycomb fired body To form a honeycomb filter. In the cross section perpendicular to the central axis direction, the honeycomb formed body at the time of firing has a direction from the center along the one partition wall toward the outer peripheral wall as “0 ° direction”, and a straight line extending in the 0 ° direction is the outer peripheral wall. When the intersecting portion is defined as “0 ° direction portion”, the outer peripheral wall is ground within a range of 10 to 100 mm in width including the “45 ° direction portion” with respect to the “0 ° direction”. A method for manufacturing a honeycomb filter having a ground portion. Here, “45 ° direction portion” when “0 ° direction” is used as a reference ”means that the angle formed between the“ 0 ° direction ”and the 45 ° angle is 45 °. ”Means a portion where a straight line extending in the“ 45 ° direction ”from the center intersects the outer peripheral wall (“ 45 ° direction portion ”). This is not limited to the case of “45 °”, and the same meaning is applied to other angles (135 °, 225 °, 315 °, etc.) in this specification. Further, when an angle such as “45 °” is considered with respect to the “0 ° direction”, the angle may be a clockwise angle from the “0 ° direction” or a counterclockwise angle. When considering a plurality of angles for one honeycomb formed body, all the angles to be considered are angles around the same direction.

  In the method for manufacturing a honeycomb filter of the present invention, the positional relationship of “45 ° direction portion”, “135 ° direction portion”, “225 ° direction portion”, and “315 ° direction portion” of the honeycomb formed body during firing Is represented in a sectional view of the honeycomb formed body 190 at the time of firing shown in FIG. 11, for example. FIG. 11 is a cross-sectional view of the honeycomb molded body 190 at the time of firing at a position that is orthogonal to the central axis direction and does not include a grinding portion in the method for manufacturing a honeycomb filter of the present invention. FIG. 11 is a view seen from above when the honeycomb formed body at the time of firing is arranged so that the central axis is oriented in the vertical direction. As shown in FIG. 11, the direction from the center 11 along the one partition wall 2 toward the outer peripheral wall 4 is the “0 ° direction”, and the portion where the straight line 12 extending in the 0 ° direction intersects the outer peripheral wall 4 is “0 °. Directional portion 13. The “45 ° direction portion” 15 is a direction from the center 11 toward the outer peripheral wall 4 and is “45 °” counterclockwise with respect to the “0 ° direction” (based on the “0 ° direction”). A straight line 14 extending in the “45 ° direction” intersects the outer peripheral wall 4 when the direction forming the angle is “45 ° direction”. The “135 ° direction portion” 17 is a direction from the center 11 toward the outer peripheral wall 4 and is an angle of “135 °” counterclockwise with respect to the “0 ° direction” (based on the “0 ° direction”). A straight line 16 extending in the “135 ° direction” intersects with the outer peripheral wall 4 when the direction in which the angle is formed is “135 ° direction”. The “225 ° direction portion” 19 is a direction from the center 11 toward the outer peripheral wall 4 and is an angle of “225 °” counterclockwise with respect to the “0 ° direction” (based on the “0 ° direction”). The straight line 18 extending in the “225 ° direction” intersects with the outer peripheral wall 4 when the direction in which the angle is formed is “225 ° direction”. The “315 ° direction portion” 21 is a direction from the center 11 toward the outer peripheral wall 4 and is an angle of “315 °” counterclockwise with respect to the “0 ° direction” (based on the “0 ° direction”). The straight line 21 extending in the “315 ° direction” is a portion where the outer peripheral wall 4 intersects with the direction of forming 315 as the “315 ° direction”.

(Grinding part of honeycomb molded body during firing)
First, the ground portion of the honeycomb formed body during firing in the method for manufacturing a honeycomb filter of the present embodiment will be described. In the method for manufacturing a honeycomb filter of the present embodiment, when the honeycomb formed body is fired to form a honeycomb fired body, the honeycomb formed body at the time of firing has at least a part of the center as shown in FIGS. In the cross section perpendicular to the axial direction, the direction from the center 11 along the one partition wall 2 toward the outer peripheral wall 4 is defined as “0 ° direction”, and the portion where the straight line 12 extending in the 0 ° direction intersects the outer peripheral wall 4 is defined as “0 °. Grinding of the outer peripheral wall 4 in a range of a width W of 10 to 100 mm including the “45 ° direction portion” 15 with respect to the “0 ° direction” when the “direction portion” is “13”. It has a portion 6. The “45 °” is an angle counterclockwise from the “0 ° direction”. The width W of the ground portion 6 is preferably 20 to 80 m, and more preferably 30 to 70 mm. Further, the width W preferably has the “45 ° direction portion” 15 as the center of the width. By setting it as such a range, it becomes possible to prevent the occurrence of “cut” effectively. If it is smaller than 10 mm, the effect of preventing the occurrence of “cutting” cannot be sufficiently obtained. If it is larger than 100 mm, the surface of the partition wall exposed to the outside in the grinding portion 6 is scraped and dropped, and in the subsequent manufacturing process There arises a problem that the honeycomb formed body and the like are soiled and the surroundings are soiled. The ground portion 6 has exposed internal partition walls, and the exposed portions of the partition walls may be scraped and fall into the firing apparatus or the like, causing problems such as adhering to the end face of the honeycomb formed body or the honeycomb fired body. Therefore, it is preferable that the area of the grinding portion 6 is not too large. Therefore, for example, as shown in FIG. 10, the ground portion 6 of the honeycomb formed body 180 may be formed between both ends of the outer peripheral wall 4 in the central axis direction, but as shown in FIG. 1. The ground portion 6 is preferably formed with a predetermined length in the central axis direction from one end portion 5 (a length shorter than the length in the central axis direction of the honeycomb formed body). Moreover, as the depth for grinding the grinding portion 6, it is preferable that all the outer peripheral wall is removed by grinding and a part of the outermost peripheral portion of the inner partition wall is further ground and removed. It may be in a state in which only the outer peripheral wall is removed by grinding, or may be in a state in which the outer peripheral side of the outer peripheral wall is ground and removed while leaving the inner portion of the outer peripheral wall slightly. Here, FIG. 1 is a perspective view schematically showing a honeycomb formed body at the time of firing in one embodiment of the method for manufacturing a honeycomb filter of the present invention. FIG. 2 is a cross-sectional view of the honeycomb molded body at the time of firing in the embodiment of the honeycomb filter manufacturing method of the present invention at a position orthogonal to the central axis direction and including a ground portion. FIG. 10 is a perspective view schematically showing a honeycomb formed body at the time of firing in another embodiment of the method for manufacturing a honeycomb filter of the present invention.

  As shown in FIG. 1, the grinding portion 6 is formed so as to extend in the central axis direction from one end portion 5 of the honeycomb formed body 100 at the time of firing, and the length L in the central axis direction of the grinding portion 6 is 5 to 5. It is preferably in the range of 20 mm, more preferably in the range of 7 to 18 mm, and particularly preferably in the range of 10 to 15 mm. By setting it as such a range, it becomes possible to prevent the occurrence of “cut” effectively. When the length L is shorter than 5 mm, the effect of preventing the occurrence of “cutting” may not be sufficiently obtained. When the length L is larger than 15 mm, the amount of the surface of the partition wall exposed to the outside in the ground portion 6 is scraped. May increase.

  When firing the honeycomb formed body, the honeycomb formed body is usually placed on a predetermined tochi in the firing apparatus with one end face (lower end face) facing down. Then, the honeycomb formed body is fired in a state where the lower end surface is in contact with the surface of Tochi. Thus, when the honeycomb fired body is fired in a state where the lower end surface is in contact with the surface of the tochi, the temperature near the lower end surface becomes slightly lower due to contact with the surface of the tochi, Since the thermal stress increases, “cuts” are likely to occur at the corners on the lower end surface side of the honeycomb formed body. Therefore, one end portion 5 of the honeycomb formed body 100 at the time of firing having the grinding portion 6 shown in FIG. 1 is on the side in contact with a part of the firing apparatus when the honeycomb formed body 100 is placed in the firing apparatus. It is preferable that it is an edge part. As described above, “part of the firing device” is “Tochi” or the like for mounting the honeycomb formed body in the firing device, which may be integrated with the firing device or separated. It may be possible to insert the honeycomb formed body into the firing apparatus in a state where it is mounted. The “end on the side in contact with a part of the firing device” is the lower end when the honeycomb formed body is placed in the firing device with one end facing downward.

  As shown in FIG. 3, in yet another embodiment of the method for manufacturing a honeycomb filter of the present invention, a honeycomb molded body 110 at the time of firing is formed with a ground portion 6a on one end portion 5 side, A ground portion 6a ′ is formed on the other end portion 7 side of the honeycomb formed body 110 at the time of firing so as to extend from the other end portion 7 in the central axis direction, and a ground portion 6a formed on the other end portion 7 side. The length of 'in the central axis direction is in the range of 5 to 20 mm. The ground portion 6a 'is formed in the range of the width W10 to 100 mm (see FIGS. 1 and 2) including the “45 ° direction portion”. As described above, when the honeycomb formed body is fired, cutting is likely to occur on the lower end side, but it may also occur on the upper end side. For this reason, as in the present embodiment, by forming the ground portions on both the lower end portion side and the upper end portion side, it becomes possible to prevent cutting at either end portion. The width, the length in the central axis direction, the depth to be ground, and the like of the grinding portion 6a ′ are the honeycomb molded body 1 at the time of firing in the embodiment of the honeycomb filter manufacturing method of the present invention (see FIGS. 1 and 2). It is preferable to set the same conditions as the width W, the length L in the central axis direction, the depth to be ground, and the like. Here, FIG. 3 is a perspective view schematically showing a honeycomb formed body at the time of firing in another embodiment of the method for manufacturing a honeycomb filter of the present invention. FIG. 3 schematically shows the outer peripheral shape of the honeycomb formed body 100 during firing and the arrangement of the grinding portions 6a and 6a '.

  As shown in FIG. 4, in still another embodiment of the method for manufacturing a honeycomb filter of the present invention, the honeycomb formed body 120 at the time of firing has a “0 ° direction” of the outer peripheral wall 4 as a reference. The outer peripheral wall 4 has a ground portion 6a ground in a range of 10 to 100 mm in width including the “45 ° direction portion”, and the outer peripheral wall 4 is ground in a range of 10 to 100 mm in width including the “225 ° direction portion”. It has the grinding part 6b made. In the present embodiment, the ground portion is formed on one end (lower end) side of the outer peripheral wall 4. In this way, by forming the ground portion 6a and the ground portion 6b on the honeycomb formed body 120 at the time of firing so that they are positioned at 180 ° from each other, the honeycomb filter to be manufactured is further enlarged, Even when the “cut” is likely to occur, the occurrence of the “cut” can be prevented. The width, the length in the central axis direction, the depth to be ground, and the like of the grinding portion 6b are the honeycomb formed body 1 at the time of firing in one embodiment of the honeycomb filter manufacturing method of the present invention (see FIGS. 1 and 2). It is preferable that the same conditions as the width W, the length L in the central axis direction, the depth to be ground, and the like of the grinding portion 6 are set. Here, FIG. 4 is a perspective view schematically showing a honeycomb formed body at the time of firing in still another embodiment of the method for manufacturing a honeycomb filter of the present invention. In addition, the honeycomb molded body at the time of firing is a ground portion in which the outer peripheral wall is ground in a range of 10 to 100 mm in width including the “45 ° direction portion” with respect to the “0 ° direction” of the outer peripheral wall. In addition, the outer peripheral wall may be ground within a range of 10 to 100 mm in width including the “135 ° direction portion”.

  As shown in FIG. 5, in still another embodiment of the method for manufacturing a honeycomb filter of the present invention, a honeycomb molded body 130 at the time of firing is formed with ground portions 6a and 6b on one end portion 5 side. At the same time, ground portions 6a ′ and 6b ′ are formed on the other end 7 side of the honeycomb formed body 130 at the time of firing so as to extend from the other end 7 in the central axis direction, and formed on the other end 7 side. The lengths of the ground portions 6a ′ and 6b ′ in the central axis direction are in the range of 5 to 20 mm, respectively. The ground portion 6a ′ is formed in a range of the width W of 10 to 100 mm (see FIGS. 1 and 2) including the “45 ° direction portion”, and the ground portion 6b ′ is the “225 ° direction portion”. It is formed in a range of 10 to 100 mm in width (the same range as the ground portion 6b). As described above, by forming the ground portions on both the lower end side and the upper end side, it becomes possible to prevent the end portions from being cut. The width, the length in the central axis direction, the depth to be ground, and the like of the grinding portions 6a ′ and 6b ′ are the honeycomb molded body 1 at the time of firing in one embodiment of the honeycomb filter manufacturing method of the present invention (FIG. 1). 2), the same conditions as the width W, the length L in the central axis direction, the depth to be ground, and the like are preferable. Here, FIG. 5 is a perspective view schematically showing a honeycomb formed body at the time of firing in still another embodiment of the method for manufacturing a honeycomb filter of the present invention.

  As shown in FIG. 6, in still another embodiment of the method for manufacturing a honeycomb filter of the present invention, the honeycomb formed body 140 at the time of firing has a “0 ° direction” of the outer peripheral wall 4 as a reference. The outer peripheral wall 4 is ground in the range of 10 to 100 mm in width including the “45 ° direction portion”, and the outer peripheral wall 4 is ground in the range of 10 to 100 mm in width including the “135 ° direction portion”. The ground portion 6c is provided, and the ground portion 6b is obtained by grinding the outer peripheral wall 4 in a range of 10 to 100 mm in width including the “225 ° direction portion”. In the present embodiment, the ground portion is formed on one end (lower end) side of the outer peripheral wall 4. Thus, since the honeycomb formed body 140 at the time of firing has three ground portions (6a, 6b and 6c) at 45 ° intervals at the lower end portion of the outer peripheral wall 4, the honeycomb filter to be manufactured is further increased in size. Thus, even when the “cut” is more likely to occur, it is possible to prevent the “cut” from occurring. The width, the length in the central axis direction, the depth to be ground, and the like of the grinding portions 6a, 6b and 6c are the honeycomb molded body 1 at the time of firing in one embodiment of the honeycomb filter manufacturing method of the present invention (FIG. 1). 2), the same conditions as the width W, the length L in the central axis direction, the depth to be ground, and the like are preferable. Here, FIG. 6 is a perspective view schematically showing a honeycomb formed body at the time of firing in still another embodiment of the method for manufacturing a honeycomb filter of the present invention.

  As shown in FIG. 7, in still another embodiment of the method for manufacturing a honeycomb filter of the present invention, a honeycomb formed body 150 at the time of firing is formed with ground portions 6a, 6b and 6c on one end portion 5 side. In addition, ground portions 6a ′, 6b ′, and 6c ′ are formed on the other end 7 side of the honeycomb formed body 150 at the time of firing so as to extend from the other end 7 in the central axis direction. The lengths of the grinding portions 6a ′, 6b ′ and 6c ′ formed on the portion 7 side in the central axis direction are in the range of 5 to 20 mm, respectively. The ground portion 6a ′ is formed in a range of the width W of 10 to 100 mm (see FIGS. 1 and 2) including the “45 ° direction portion”, and the ground portion 6b ′ is the “225 ° direction portion”. The range including the width of 10 to 100 mm (the same range as the grinding portion 6b) is included, and the grinding portion 6c ′ is the range including the “135 ° direction portion” and the width of 10 to 100 mm (the same as the grinding portion 6c) Range). As described above, by forming the ground portions on both the lower end side and the upper end side, it becomes possible to prevent the end portions from being cut. The width, the length in the central axis direction, the depth to be ground, etc. of the grinding parts 6a ′, 6b ′ and 6c ′ are the honeycomb molded body 1 at the time of firing in one embodiment of the honeycomb filter manufacturing method of the present invention. It is preferable to use the same conditions as the width W, the length L in the central axis direction, the depth to be ground, and the like of the grinding portion 6 (see FIGS. 1 and 2). Here, FIG. 7 is a perspective view schematically showing a honeycomb formed body at the time of firing in still another embodiment of the method for manufacturing a honeycomb filter of the present invention.

  As shown in FIG. 8, in yet another embodiment of the method for manufacturing a honeycomb filter of the present invention, the honeycomb formed body 160 at the time of firing is “when the“ 0 ° direction ”of the outer peripheral wall 4 is used as a reference. The outer peripheral wall 4 is ground in the range of 10 to 100 mm in width including the “45 ° direction portion”, and the outer peripheral wall 4 is ground in the range of 10 to 100 mm in width including the “135 ° direction portion”. The outer peripheral wall 4 has a ground portion 6b that is ground in a range of 10 to 100 mm in width including the “225 ° direction portion”, and further includes the “315 ° direction portion”. The outer peripheral wall 4 has a ground portion 6d ground within a width range of 10 to 100 mm. In the present embodiment, the ground portion is formed on one end (lower end) side of the outer peripheral wall 4. Thus, since the honeycomb molded body 160 at the time of firing has four ground portions (6a, 6b, 6c, and 6d) at 45 ° intervals at the lower end portion of the outer peripheral wall 4, the honeycomb filter to be manufactured has a larger size. Therefore, even when “cut” is more likely to occur, the occurrence of “cut” can be prevented. The width, the length in the central axis direction, the depth to be ground, etc. of the grinding portions 6a, 6b, 6c and 6d are the honeycomb molded body 1 at the time of firing in one embodiment of the method for manufacturing a honeycomb filter of the present invention ( It is preferable that the conditions are the same as the width W, the length L in the central axis direction, the depth to be ground, and the like of the grinding portion 6 in FIGS. Here, FIG. 8 is a perspective view schematically showing a honeycomb formed body at the time of firing in still another embodiment of the method for manufacturing a honeycomb filter of the present invention.

  As shown in FIG. 9, in still another embodiment of the method for manufacturing a honeycomb filter of the present invention, a honeycomb formed body 170 at the time of firing has ground portions 6a, 6b, 6c and 6d on one end portion 5 side. Are formed, and ground portions 6a ′, 6b ′, 6c ′ and 6d ′ are formed on the other end 7 side of the honeycomb formed body 170 at the time of firing so as to extend from the other end 7 in the central axis direction. The lengths of the grinding portions 6a ′, 6b ′, 6c ′ and 6d ′ formed on the other end 7 side in the central axis direction are each in the range of 5 to 15 mm. The ground portion 6a ′ is formed in a range of the width W of 10 to 100 mm (see FIGS. 1 and 2) including the “45 ° direction portion”, and the ground portion 6b ′ is the “225 ° direction portion”. The range including the width of 10 to 100 mm (the same range as the grinding portion 6b) is included, and the grinding portion 6c ′ is the range including the “135 ° direction portion” and the width of 10 to 100 mm (similar to the grinding portion 6c). The grinding portion 6d ′ is formed in a range of 10 to 100 mm in width including the “315 ° direction portion” (the same range as the grinding portion 6d). As described above, by forming the ground portions on both the lower end side and the upper end side, it becomes possible to prevent the end portions from being cut. The width, the length in the central axis direction, the depth to be ground, etc. of the grinding portions 6a ′, 6b ′, 6c ′ and 6d ′ are the same as those of the honeycomb filter manufacturing method of the present invention. It is preferable that the ground portion 6 of the molded body 1 (see FIGS. 1 and 2) has the same conditions as the width W, the length L in the central axis direction, the depth to be ground, and the like. Here, FIG. 9 is a perspective view schematically showing a honeycomb formed body at the time of firing in still another embodiment of the method for manufacturing a honeycomb filter of the present invention.

  Hereinafter, an embodiment of a method for manufacturing a honeycomb filter of the present invention will be described in the order of manufacturing steps.

(Soil)
The clay used in one embodiment of the method for manufacturing a honeycomb filter of the present invention contains a ceramic raw material. As the ceramic raw material, cordierite forming raw material, silicon carbide, sialon, mullite, silicon nitride, zirconium phosphate, zirconia, titania, alumina, silica, etc. can be used, but cordierite with excellent thermal shock resistance can be used. Raw materials are preferred. The cordierite-forming raw material means a raw material that becomes cordierite by firing, and has a chemical composition in which silica is in the range of 42 to 56% by mass, alumina is in the range of 30 to 45% by mass, and magnesia is in the range of 12 to 16% by mass. It is the ceramic raw material mix | blended so that it may become. Specific examples include those containing a plurality of inorganic raw materials selected from talc, kaolin, calcined kaolin, alumina, aluminum hydroxide, and silica in a proportion such that the above chemical composition is obtained.

  The clay used in the present embodiment contains the ceramic raw material, and it is preferable that a dispersion medium such as water and a pore forming material are added, and an organic binder and a dispersant are included. And it is preferable to prepare clay-like clay by mixing and kneading these raw materials.

  As the pore former, any material that can be scattered and disappeared by the firing process may be used. An inorganic substance such as coke, a polymer compound such as foamed resin, an organic substance such as starch, etc. may be used alone or in combination. it can.

  As the organic binder, hydroxypropylmethylcellulose, methylcellulose, hydroxyethylcellulose, carboxymethylcellulose, polyvinyl alcohol and the like can be used. These may be used individually by 1 type, and may be used in combination of 2 or more type.

  As the dispersant, ethylene glycol, dextrin, fatty acid soap, polyalcohol and the like can be used. These may be used individually by 1 type, and may be used in combination of 2 or more type.

  There is no restriction | limiting in particular as a method of knead | mixing a ceramic raw material and preparing a kneaded material, For example, the method of using a kneader, a vacuum clay kneader, etc. can be mentioned.

(Formation of honeycomb molded body)
Next, a kneaded clay is formed to produce a honeycomb formed body having porous partition walls that define a plurality of cells and an outer peripheral wall disposed on the outer periphery of the partition walls. There is no restriction | limiting in particular as a method of producing a honeycomb molded object, Conventionally well-known shaping | molding methods, such as extrusion molding, injection molding, and press molding, can be used. Among them, a preferable example is a method of extruding the clay prepared as described above using a die having a desired cell shape, partition wall thickness, and cell density.

(Grinded part of honeycomb molded body)
The ground portion of the honeycomb formed body at the time of firing may be formed while forming the honeycomb formed body, or may be formed after forming the honeycomb formed body and before firing. When forming the ground portion while forming the honeycomb formed body, for example, as shown in FIG. 14, the back pressing plate 50 is disposed on the upstream side of the die for extrusion molding (the back hole side where the clay flows in). Can be used. The protrusion 51 of the back pressing plate 50 prevents the flow of the clay, and the ground portion 6 is formed at that portion. In this case, it is possible to obtain a honeycomb formed body having a structure like the honeycomb formed body 180 having the grinding portion 6 extending between both end portions shown in FIG. Although the material of the back pressing plate 50 is not particularly limited, for example, stainless steel or the like is preferable. Here, FIG. 14 is a plan view schematically showing a back pressing plate disposed on the upstream side of a die used for forming a honeycomb formed body in the method for manufacturing a honeycomb filter of the present invention. Moreover, before the honeycomb formed body is formed and dried, or after the formed honeycomb formed body is dried and fired, the above-described honeycomb formed body (100, 110, 120, 130) shown in FIGS. , 140, 150, 160, 170), a ground portion having a desired shape may be formed. In this case, it is preferable to form the ground portion by a method of processing the outer periphery with a grindstone.

(Plugged)
After forming the honeycomb formed body, it is preferable to plug both ends of the obtained honeycomb formed body. The method of plugging is not particularly limited. For example, first, one end face is alternately covered with cell openings and masked in a checkered pattern. Further, a plugging slurry containing a ceramic raw material such as a cordierite forming raw material, water or alcohol, and an organic binder is stored in a storage container. And the edge part by the side which gave the said mask is immersed in a storage container, a plugging slurry is filled into the opening part of the cell which is not giving the mask, and a plugging part is formed. For the other end, a mask is applied to the cells plugged at one end, and the plugged portion is formed in the same manner as the plugged portion is formed at the one end. As a result, the cells not plugged at the one end are plugged at the other end, and the cells are alternately closed in a checkered pattern at the other end. The plugging of the honeycomb formed body may be formed before the ground portion is formed, or may be formed after the ground portion is formed.

(Dry)
Next, it is preferable to dry the plugged honeycomb formed body. The drying method is not particularly limited, and conventionally known drying methods such as hot air drying, microwave drying, dielectric drying, reduced pressure drying, vacuum drying, freeze drying and the like can be used. Especially, the drying method which combined hot air drying, microwave drying, or dielectric drying is preferable at the point which can dry the whole molded object rapidly and uniformly.

(Baking)
Next, the honeycomb formed body is fired to produce a honeycomb fired body. By firing, the ceramic raw material of the honeycomb formed body can be sintered and densified to ensure a predetermined strength. Since the firing conditions (temperature and time) vary depending on the type of ceramic raw material, an appropriate condition may be selected according to the type. For example, in the case of firing a cordierite raw material, the temperature is 1410 to 1440 ° C. It is preferable to fire.

(Grinding of outer wall)
Next, the outer peripheral wall of the honeycomb fired body is ground to produce a ground honeycomb fired body. The method for grinding the outer peripheral wall of the honeycomb fired body is not particularly limited, and a known grinding method can be used. Examples of the grinding method include a cylindrical grinder.

(Outer periphery coat)
Next, an outer peripheral coat wall is formed on the outer periphery of the ground honeycomb fired body to produce a honeycomb filter. The outer peripheral coat wall is preferably formed by applying an outer peripheral coat material to the outer periphery of the ground honeycomb fired body. It does not specifically limit as an outer periphery coating material, A well-known outer periphery coating material can be used. Moreover, the coating method of an outer periphery coating material is not specifically limited, A well-known method can be used.

  The shape of the honeycomb filter manufactured by the method for manufacturing a honeycomb filter of the present invention is not particularly limited. For example, the shape is cylindrical, the bottom is a racetrack, the bottom is an oval, the square A columnar shape, a triangular prism shape, a cylindrical shape with a trapezoidal bottom shape, and other prismatic shapes can be exemplified. Furthermore, in the quadrangular prism shape, the triangular prism shape, the cylindrical shape having a trapezoidal bottom surface, and the other prismatic shapes, the corner portions in the cross section orthogonal to the central axis direction are preferably rounded shapes such as an arc shape. And as for the magnitude | size, it is preferable that the length of a central axis direction is 50-600 mm, and it is still more preferable that it is 100-500 mm. Here, the racetrack shape is an outer peripheral shape when two small circles arranged side by side are connected by two common tangents that do not intersect with a line segment connecting the centers of the small circles. The oval shape is obtained by connecting two small circles lined up so that they protrude outward with a great circle arc instead of connecting two common tangents that do not intersect the line connecting the centers of the small circles. It is a perimeter shape. Moreover, when the shape of the bottom face of the obtained honeycomb filter is, for example, a cylindrical shape, the radius is preferably 30 to 300 mm, more preferably 50 to 250 mm, and 75 to 250 mm. It is particularly preferred. Further, when the shape of the bottom surface of the obtained honeycomb filter is, for example, an oval shape or a race track shape, the major axis is preferably more than 1.0 times and less than 3.0 times the minor axis. More preferably, it is more than 0 times and 2.5 times or less. And it is preferable that a major axis is 150-300 mm and a minor axis is 50-250 mm. Moreover, when the shape of the bottom face of the obtained honeycomb filter is, for example, a square, the length of one side is preferably 30 to 500 mm, more preferably 50 to 400 mm, and 75 to 350 mm. It is particularly preferred that When such a large honeycomb filter is manufactured, “cutting” is likely to occur, so that the method for manufacturing a honeycomb filter of the present invention can be used effectively.

  Further, the cell shape of the honeycomb filter (cell shape in a cross section perpendicular to the direction in which the central axis of the honeycomb filter extends (cell extending direction)) is not particularly limited, and examples thereof include a quadrangle, a hexagon, and a triangle. be able to.

  In the honeycomb filter manufactured by the honeycomb filter manufacturing method of the present embodiment, the partition wall thickness is not particularly limited, but if the partition wall thickness is too thick, the pressure loss when the fluid permeates is large. If it is too thin, the strength may be insufficient. The thickness of the partition wall is preferably 30 to 2000 μm, more preferably 50 to 1500 μm, and particularly preferably 100 to 750 μm.

  The porosity of the porous partition walls constituting the honeycomb filter manufactured by the honeycomb filter manufacturing method of the present embodiment is not particularly limited. For example, the porosity is preferably 20 to 80%, and 30 More preferably, it is -70%. The porosity means volume% and is a value measured with a mercury porosimeter. The porosity of the partition walls can be set to a desired value by adjusting the pore former at the time of manufacturing the honeycomb filter.

In the honeycomb filter manufactured by the manufacturing method of the honeycomb filter of the present embodiment, the cell density is not particularly limited, preferably from 1.5 to 350 cells / cm ^2, at 7-300 cells / cm ² More preferably, it is more preferably 10 to 250 cells / cm ² .

  In the honeycomb filter manufactured by the method for manufacturing a honeycomb filter according to the present embodiment, the material of the plugging member for plugging each cell is not particularly limited, but may be mentioned as the partition wall material of the honeycomb filter described above. It is preferable that it is at least one selected from the above.

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

Example 1
Silica, talc, and alumina were used as cordierite forming raw materials. To 100 parts by weight of cordierite forming raw material, 25 parts by weight of water as a dispersion medium, 10 parts by weight of a pore former, 5 parts by weight of an organic binder, and 0.5 parts by weight of a dispersant are added, mixed and kneaded. Soil was prepared. Coke was used as the pore former, hydroxypropyl methylcellulose was used as the organic binder, and fatty acid soap was used as the dispersant. A pore former having an average particle diameter of 40 μm was used. As the mixing device, a Laedige mixer was used, and as the kneading device, a kneader and a vacuum kneader were used.

  The obtained kneaded material was extruded to produce a honeycomb formed body having a square cell cross-sectional shape and a cylindrical overall shape.

  Next, the obtained honeycomb formed body was plugged. The cell opening on one end face of the obtained honeycomb formed body is alternately masked in a checkered pattern, and the end on the masked side is immersed in a plugging slurry containing a cordierite forming raw material. Then, plugged portions alternately arranged in a checkered pattern were formed. Further, for the other end, a mask is applied to the cells plugged at one end, and the plugged portion is formed in the same manner as the plugged portion is formed at the one end. did.

  Next, as shown in FIGS. 1 and 2, the dried honeycomb molded body is ground with a width of 50 mm including a “45 ° direction portion” (position of the grinding portion) and a length of 10 mm in the central axis direction. Part was formed. The ground portion was formed so that the “45 ° direction portion” was positioned at the center of its width. Table 1 shows the “position of the grinding part” and the “dimension of the grinding part”. The “lower side” column of “position of the grinding portion” indicates the position of the grinding portion provided on the lower end side, and the “upper side” column indicates the position of the grinding portion provided on the upper end side. The “angle” shown in the column “Position of grinding part” indicates “the angular direction part” in the honeycomb formed body. Also, the “width” column of “dimension of the grinding part” indicates the circumferential length of the grinding part around the position indicated by “position of the grinding part”, and “length” of “dimension of the grinding part”. The column “” indicates the length of the ground portion in the central axis direction at “position of the ground portion”.

  Next, the honeycomb formed body was fired to obtain a honeycomb filter (Example 1). Twenty honeycomb filters were produced under the same conditions. At the time of firing, the honeycomb formed body was placed on the tochi in the firing apparatus with one end (lower end) facing downward. The firing temperature was 1410 to 1440 ° C. and 150 hours.

The obtained honeycomb filter had a cylindrical shape with a diameter of 300 mm and a length in the central axis direction of 300 mm, a partition wall thickness of 0.3 mm, a cell density cell of 47 / cm ² , and a partition wall porosity of 50%.

  About 20 obtained honey-comb filters, generation | occurrence | production of "cut" was confirmed visually. The obtained results are shown in Table 1. In Table 1, the “lower” column of “number of occurrences” indicates the state of the lower end portion of the honeycomb filter, and the “upper” column indicates the state of the upper end portion of the honeycomb filter. The “number of cut occurrences” column is indicated by “(number of cut occurrences) / (number of confirmed honeycomb filters)”. For example, when “3/20” is displayed, it indicates that “cut” has occurred in three of the 20 honeycomb filters. Pass / fail judgment for each honeycomb filter (determination of whether “cut” has occurred) passes when the number of cuts on the lower end side and upper end side is zero (“no cut” has occurred) It was. And the case where the number of honeycomb filters in which “cut” on the lower end side occurred was 5 or less was regarded as acceptable for the occurrence of “cut” on the lower end side. Furthermore, when the number of honeycomb filters in which “cut” on the upper end side occurred was 5 or less, the occurrence of “cut” on the upper end side was regarded as acceptable.

  Further, the “number of damaged defects” was confirmed for 20 honeycomb filters. The “damage defect” refers to scratches on the end face, dents, etc. that occur in the honeycomb filter at the partition walls of the ground part. The column “number of damaged defects” is indicated by “(number of damaged defects) / (number of confirmed honeycomb filters)”. For example, when “0/20” is displayed, it indicates that “damage failure” has occurred for 0 of the 20 honeycomb filters. In the pass / fail determination (determination of whether or not “damage failure” occurred), the case where “damage failure” did not occur on the end face was determined to be acceptable (no “damage failure” occurred). A case where the number of honeycomb filters in which “damage failure” occurred was 3 or less was regarded as acceptable for the occurrence of “damage failure”. And, when the occurrence of “cut” on the lower end side, the occurrence of “cut” on the upper end side, and the occurrence of “damage defect” are all acceptable, the honeycomb filter manufacturing method as a whole is acceptable. .

(Porosity)
The porosity was measured using a mercury porosimeter manufactured by MIC.

(Example 2)
As shown in FIG. 4, the dried honeycomb formed body has a width of 50 mm including a “45 ° direction portion”, a ground portion having a length of 10 mm in the central axis direction, and a width including a “225 ° direction portion”. A honeycomb filter (Example 2) was produced in the same manner as in Example 1 except that a ground part having a length of 50 mm and a central axis direction length of 10 mm was formed. The “45 ° direction portion” and the “225 ° direction portion” were formed so as to be positioned at the center of the width of each ground portion. In the same manner as in Example 1, the occurrence of “cut” and “damage” was confirmed. The results are shown in Table 1.

(Example 3)
As shown in FIG. 8, the dried honeycomb formed body has a width of 50 mm including a “45 ° direction portion”, a ground portion having a central axis length of 10 mm, and a width including a “135 ° direction portion”. 50 mm, grinding part with a central axis length of 10 mm, a width of 50 mm including a “225 ° direction part”, a grinding part with a central axis direction length of 10 mm, a width of 50 mm including a “315 ° direction part”, a central axis direction length A honeycomb filter (Example 3) was produced in the same manner as in Example 1 except that a 10 mm-long ground portion was formed. The “45 ° direction portion”, “135 ° direction portion”, “225 ° direction portion”, and “315 ° direction portion” were formed so as to be located at the center of the width of each grinding portion. In the same manner as in Example 1, the occurrence of “cut” and “damage” was confirmed. The results are shown in Table 1.

Example 4
Implementation was performed except that a dried portion of the honeycomb formed body was formed with a ground portion having a width of 50 mm including a “45 ° direction portion” and a length of 10 mm in the central axis direction as shown in FIG. In the same manner as in Example 1, a honeycomb filter (Example 4) was produced. The “45 ° direction portion” was formed so as to be located at the center of the width of the ground portion. In the same manner as in Example 1, the occurrence of “cut” and “damage” was confirmed. The results are shown in Table 1.

(Example 5)
As shown in FIG. 5, each of the dried honeycomb formed body has a ground portion having a width of 50 mm including a “45 ° direction portion” and a length of 10 mm in the central axis direction, and “225 °”. A honeycomb filter (Example 5) was produced in the same manner as in Example 1 except that a ground part having a width of 50 mm including the directional part and a length of 10 mm in the central axis direction was formed. The “45 ° direction portion” and the “225 ° direction portion” were formed so as to be positioned at the center of the width of each ground portion. In the same manner as in Example 1, the occurrence of “cut” and “damage” was confirmed. The results are shown in Table 1.

(Example 6)
As shown in FIG. 9, each of the dried honeycomb formed body has a ground portion having a width of 50 mm including a “45 ° direction portion” and a central axis direction length of 10 mm as shown in FIG. 50 mm wide including the directional portion and 10 mm long in the central axial direction, 50 mm wide including the 225 ° directional portion, 10 mm long grounded in the central axial direction, and 315 ° directional width. A honeycomb filter (Example 6) was produced in the same manner as in Example 1 except that a ground part having a length of 50 mm and a central axis direction length of 10 mm was formed. The “45 ° direction portion”, “135 ° direction portion”, “225 ° direction portion”, and “315 ° direction portion” were formed so as to be located at the center of the width of each grinding portion. In the same manner as in Example 1, the occurrence of “cut” and “damage” was confirmed. The results are shown in Table 1.

(Example 7)
Except that the width of the ground portion formed on the lower end side (upper end side) of the dried honeycomb molded body is 50 mm and the length in the central axis direction is the same as the length in the central axis direction of the honeycomb molded body In the same manner as in Example 6, a honeycomb filter (Example 7) was produced. In the present embodiment, the grinding portion on the upper end side and the grinding portion on the lower end side are in a state of being extended and connected in the central axis direction, for example, as the grinding portion 6 in FIG. In the same manner as in Example 1, the occurrence of “cut” and “damage” was confirmed. The results are shown in Table 1.

(Example 8)
A honeycomb filter (Example 8) was produced in the same manner as in Example 7 except that the width of the ground portion formed on the lower end side (upper end side) of the dried honeycomb formed body was 20 mm. In the present embodiment, the grinding portion on the upper end side and the grinding portion on the lower end side are in a state of being extended and connected in the central axis direction, for example, as the grinding portion 6 in FIG. In the same manner as in Example 1, the occurrence of “cut” and “damage” was confirmed. The results are shown in Table 1.

Example 9
A honeycomb filter (Example 9) was produced in the same manner as Example 3 except that the width of the ground portion formed on the lower end side of the dried honeycomb formed body was set to 100 mm. In the same manner as in Example 1, the occurrence of “cut” and “damage” was confirmed. The results are shown in Table 1.

(Example 10)
A honeycomb filter (Example 10) was produced in the same manner as in Example 3 except that the length in the central axis direction of the ground portion formed on the lower end side of the dried honeycomb formed body was 20 mm. In the same manner as in Example 1, the occurrence of “cut” and “damage” was confirmed. The results are shown in Table 1.

(Comparative Example 1)
A honeycomb filter (Comparative Example 1) was produced in the same manner as in Example 1 except that the ground portion was not formed on the dried honeycomb molded body. In the same manner as in Example 1, the occurrence of “cut” and “damage” was confirmed. The results are shown in Table 1.

(Comparative Example 2)
A honeycomb filter (Comparative Example 2) was produced in the same manner as in Example 6 except that the width of the ground portion formed on the dried honeycomb formed body was changed to 5 mm. In the same manner as in Example 1, the occurrence of “cut” and “damage” was confirmed. The results are shown in Table 1.

(Comparative Example 3)
A honeycomb filter (Comparative Example 3) was produced in the same manner as in Example 6 except that the width of the ground portion formed on the dried honeycomb molded body was 150 mm. In the same manner as in Example 1, the occurrence of “cut” and “damage” was confirmed. The results are shown in Table 1.

(Comparative Example 4)
A honeycomb filter (Comparative Example 4) was produced in the same manner as in Example 4 except that the ground portion formed on the dried honeycomb molded body was formed in a range of a width of 50 mm including the “0 ° direction portion”. In the same manner as in Example 1, the occurrence of “cut” and “damage” was confirmed. The results are shown in Table 1.

(Comparative Example 5)
The upper end side and the lower end side ground portions formed on the dried honeycomb formed body are respectively “0 ° direction portion”, “90 ° direction portion”, “180 ° direction portion”, and “270 ° direction portion”. A honeycomb filter (Comparative Example 5) was produced in the same manner as in Example 6 except that the position was changed to a position containing. The “0 ° direction portion”, “90 ° direction portion”, “180 ° direction portion”, and “270 ° direction portion” were formed so as to be positioned at the center of the width of each grinding portion. In the same manner as in Example 1, the occurrence of “cut” and “damage” was confirmed. The results are shown in Table 1.

  From Table 1, it can be seen that the ground portion including the “45 ° direction portion” is effective for cutting. Further, it can be seen that many “cuts” and “damage defects” occur even when the width of the ground portion is reduced or increased with respect to the range of 10 to 100 mm.

(Example 11)
The shape of the honeycomb formed body was the same as in Example 1 except that the cross-sectional shape perpendicular to the central axis direction was a cylindrical shape having an “oval shape with a major axis of 250 mm and a minor axis of 100 mm” and the partition wall porosity was 60%. 20 honeycomb filters were manufactured. In the obtained honeycomb filter, in the cross section orthogonal to the central axis direction, the cells are partitioned and formed by the partition walls parallel to the major axis and the partition walls parallel to the minor axis. About the obtained honeycomb filter, generation | occurrence | production of "cut" and "damage defect" was confirmed similarly to the case of Example 1. The results are shown in Table 2.

(Examples 12 to 20)
Twenty honeycomb filters were produced in the same manner as in Example 11 except that the position of the grinding part and the dimensions of the grinding part were changed as shown in Table 2. The position of the grinding part and the dimension of the grinding part in the manufacturing method of the honeycomb filter of Examples 12 to 20 are respectively the same as the position of the grinding part and the dimension of the grinding part in the manufacturing method of the honeycomb filter of Examples 2 to 10, respectively. is there. About the obtained honeycomb filter, generation | occurrence | production of "cut" and "damage defect" was confirmed similarly to the case of Example 1. The results are shown in Table 2.

(Comparative Examples 6 to 10)
Twenty honeycomb filters were produced in the same manner as in Example 11 except that the position of the grinding part and the dimensions of the grinding part were changed as shown in Table 2. The position of the grinding part and the size of the grinding part in the manufacturing method of the honeycomb filter of Comparative Examples 6 to 10 are respectively the same as the position of the grinding part and the dimension of the grinding part in the manufacturing method of the honeycomb filter of Comparative Examples 1 to 5, respectively. is there. About the obtained honeycomb filter, generation | occurrence | production of "cut" and "damage defect" was confirmed similarly to the case of Example 1. The results are shown in Table 2.

  From Table 2, it can be seen that the ground portion including the “45 ° direction portion” is effective for cutting. Further, it can be seen that many “cuts” and “damage defects” occur even when the width of the ground portion is reduced or increased with respect to the range of 10 to 100 mm.

  The method for manufacturing a honeycomb filter according to the present invention removes particulate matter in exhaust gas discharged from an internal combustion engine such as an automobile engine, a construction machine engine, an industrial engine stationary engine, or other combustion equipment. Therefore, it can be used for manufacturing a honeycomb filter used for the purpose.

Claims (9)

Forming a clay containing a ceramic raw material to produce a honeycomb molded body having a porous partition wall defining a plurality of cells and an outer peripheral wall disposed on the outer periphery of the partition wall; A honeycomb fired body is manufactured by firing, an outer peripheral wall of the honeycomb fired body is ground to prepare a ground honeycomb fired body, and an outer peripheral coat wall is formed on the outer periphery of the ground honeycomb fired body to prepare a honeycomb filter A method for manufacturing a filter, comprising:
The honeycomb formed body at the time of firing is
In a cross section perpendicular to the central axis direction, a direction from the center toward the outer peripheral wall along one partition wall is defined as “0 ° direction”, and a portion where a straight line extending in the 0 ° direction intersects the outer peripheral wall is defined as “0 ° direction”. "Part"
A method for manufacturing a honeycomb filter having a ground portion in which the outer peripheral wall is ground within a range of a width of 10 to 100 mm including a "45 ° direction portion" with respect to the "0 ° direction" of the outer peripheral wall. The honeycomb formed body at the time of firing is further
2. The honeycomb according to claim 1, wherein the outer peripheral wall has a ground portion in which the outer peripheral wall is ground within a range of 10 to 100 mm in width including a “135 ° direction portion” with respect to the “0 ° direction”. A method for manufacturing a filter. The honeycomb formed body at the time of firing is further
3. The ground portion according to claim 1, wherein the outer peripheral wall has a ground portion in which the outer peripheral wall is ground in a range of a width of 10 to 100 mm including a “225 ° direction portion” with respect to the “0 ° direction”. Method for manufacturing a honeycomb filter. The honeycomb formed body at the time of firing is further
The honeycomb according to claim 3, wherein the outer peripheral wall has a ground portion in which the outer peripheral wall is ground in a range of a width of 10 to 100 mm including a "315 ° direction portion" with respect to the "0 ° direction". A method for manufacturing a filter.   The ground portion is formed so as to extend in the central axis direction from one end of the honeycomb formed body at the time of firing, and the length of the ground portion in the central axis direction is in the range of 5 to 20 mm. 5. A method for manufacturing a honeycomb filter according to any one of 4 above.   The one end portion of the honeycomb formed body at the time of firing having the grinding portion is an end portion on a side in contact with a part of the firing apparatus when the honeycomb formed body is placed in the firing apparatus. Method for manufacturing a honeycomb filter.   The ground portion is formed on one end side of the honeycomb formed body at the time of firing, and extends from the other end portion in the central axis direction to the other end side of the honeycomb formed body at the time of firing. A method for manufacturing a honeycomb filter according to claim 5 or 6, wherein a ground portion is formed on the other end portion side, and a length in a central axis direction of the ground portion formed on the other end portion side is in a range of 5 to 20 mm.   The method for manufacturing a honeycomb filter according to any one of claims 1 to 7, wherein the ground portion is formed after the kneaded material is formed to produce the honeycomb formed body and before the honeycomb formed body is fired.   The method for manufacturing a honeycomb filter according to any one of claims 1 to 4, wherein when forming the kneaded material to manufacture the honeycomb formed body, the honeycomb formed body is formed while forming the ground portion.

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