JP2018024220A - Honeycomb structure forming die - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a honeycomb structure forming die capable of forming a honeycomb molded body having a different cell structure between a central portion and an outer peripheral portion with high quality.SOLUTION: A honeycomb structure forming die includes a first die 10 having a projection 16 where a central portion 15 on a clay discharge surface 18 side is projected toward the downstream side in a clay extrusion direction X, an annular second die 20 having a shape complementary to the projection 16 of the first die 10, and a mesh member 30 disposed between the first die 10 and the second die 20. The first die 10 is formed with first clay introduction holes 12 and formed with lattice-shaped first slits 11 on the clay discharge surface 18 side of the projection 16, and the second die 20 is formed with second clay introduction holes 22 and lattice-shaped second slits 21 communicating with the second clay introduction holes 22. Clay is moved between the first clay introduction holes 12 and the second clay introduction holes 22 via the mesh of the mesh member 30.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a die for forming a honeycomb structure. More specifically, the present invention relates to a die for forming a honeycomb structure capable of forming a honeycomb formed body having a different cell structure between a central portion and an outer peripheral portion with high quality.

  2. Description of the Related Art Conventionally, a honeycomb structure carrying a catalyst is used for purification treatment of harmful substances such as HC, CO and NOx contained in exhaust gas discharged from an engine such as an automobile. The honeycomb structure is also used as an exhaust gas purifying filter by plugging the openings of the cells defined by the porous partition walls.

  The honeycomb structure is a columnar structure having partition walls that partition and form a plurality of cells serving as exhaust gas flow paths. Such a honeycomb structure has a cell structure in which a plurality of cells are regularly arranged at a predetermined cycle on a plane orthogonal to the cell extending direction. Conventionally, one honeycomb structure has one type of cell structure in the plane, but recently, for the purpose of improving exhaust gas purification efficiency, the cell has two or more types of cell structures in the plane. Honeycomb structures have been proposed. For example, a honeycomb structure having two types of cell structures in the plane has been proposed by making the cell density and cell shape different in the central portion and the outer peripheral portion of the plane orthogonal to the cell extending direction. .

  Such a honeycomb structure is manufactured by forming a kneaded material containing a ceramic forming raw material with a die for extrusion molding to manufacture a honeycomb formed body, and drying and firing the manufactured honeycomb formed body. The die for forming a honeycomb structure is produced, for example, by forming a back hole for introducing clay and a slit communicating with the back hole in a metal base material (for example, (See Patent Documents 1 to 4). Hereinafter, the honeycomb structure forming die may be simply referred to as “forming die” or “die”.

Japanese Patent Laying-Open No. 2015-096310 JP2013-132879A JP2013-132881A JP-A-4-332604

  For example, the die described in Patent Document 1 includes a first die located on the upstream side in the raw material extrusion direction and a second die located on the downstream side. The first mold has a convex portion protruding from the periphery on the downstream side in the extrusion direction, and the second mold has a through-hole that fits into the convex portion. And in the nozzle | cap | die of patent document 1, the convex part of a 1st metal mold | die is inserted in the through-hole of a 2nd metal mold | die, and the 1st metal mold | die and the 2nd metal mold | die are integrated.

  However, the die described in Patent Document 1 has a problem in that there are design restrictions when the die for forming a honeycomb formed body for producing a honeycomb structure having two types of cell structures is used. It was. That is, normally, in a die for forming a honeycomb formed body, “grid-like slits” corresponding to the cell structure of the honeycomb formed body are formed on the clay discharge surface side of the base substrate. And in such a nozzle | cap | die, the back hole as a raw material supply hole is formed so that it may connect with the intersection part of a grid | lattice-like slit. In the die described in Patent Document 1, when the shapes of the slits are different between the first mold and the second mold, all the back holes in the first mold (that is, the first raw material supply holes). It is difficult to completely match all the back holes (that is, the second raw material supply holes) in the second mold. If all the back holes do not match, when the first mold and the second mold are integrated, the movement of the clay in the die is hindered, and uniform extrusion molding becomes difficult. For this reason, in the die described in Patent Document 1, it is necessary to select the shape of each slit formed in the first die and the second die so that the movement of the clay as described above is not hindered. Yes, the design freedom was very low.

  The die described in Patent Documents 2 and 3 is not a die for forming a honeycomb formed body having two types of cell structures, but a die intended to improve cell quality only in the outermost peripheral part. The bases described in Patent Documents 2 and 3 have a problem that they cannot cope with the formation of various honeycomb molded bodies in which the shapes of the two types of cell structures and the formation range thereof change over a wide range. . For example, a honeycomb structure having two types of cell structures may have a boundary wall disposed so as to surround the cell structure in the central portion at the boundary between the cell structure in the central portion and the cell structure in the outer peripheral portion. is there. The boundary wall requires a large amount of clay as a forming raw material as compared with the partition walls constituting the cell structure of the central portion and the outer peripheral portion at the time of extrusion molding. When forming the honeycomb formed body having the boundary wall as described above by the die described in Patent Documents 2 and 3, supply of the clay for forming the boundary wall cannot catch up, and in the boundary wall and the vicinity thereof, May cause molding defects. In addition, since the caps described in Patent Documents 2 and 3 are intended to improve the cell quality only in the outermost peripheral portion, there is a problem in the strength of the shell portion. There are concerns about problems such as deformation of the part.

  The base described in Patent Document 4 has a structure in which an extrusion die is used to wedge-tighten or mesh with an adjacent die body, so that the pressure resistance to the clay is low and the base is easily damaged. There was a problem. Further, the die described in Patent Document 4 has a problem that it is easy to induce a positional deviation of the back hole and easily causes a molding defect.

  In addition, a honeycomb formed body having two types of cell structures may have a boundary wall that partitions the two types of cell structures at the boundary between the central portion and the outer peripheral portion of the honeycomb formed body. Such a boundary wall differs in the amount of clay consumed at the time of extrusion molding as compared with a partition wall formed around the boundary wall. For this reason, the honeycomb molded body having two types of cell structures has a problem that molding defects are likely to occur particularly around the boundary wall. In addition, for example, when extrusion molding is performed by changing the type of clay as a forming raw material, the fluidity of the clay changes, so the honeycomb molded body having a boundary wall is extruded. The base was very poor in versatility.

  The present invention has been made in view of the above-described problems. The present invention provides a die for forming a honeycomb structure capable of forming a honeycomb formed body having different cell structures at the central portion and the outer peripheral portion with high quality.

  According to the present invention, the following honeycomb structure forming die is provided.

[1] A first die having a convex portion that is disposed on the upstream side in the extrusion direction of the clay as a forming raw material, and the central portion on the clay discharge surface side protrudes toward the downstream side in the extrusion direction;
An annular second base disposed on the downstream side of the first base and having a shape complementary to the convex portion;
In the central portion of the first base, a first clay introduction hole and a lattice-shaped first slit communicating with the first clay introduction hole are formed,
In the outer peripheral portion surrounding the central portion of the first base, the first clay introduction hole is formed so as to penetrate the outer peripheral portion of the first base,
In the annular second base, a second clay introduction hole into which the clay discharged from the first clay introduction hole formed in the outer peripheral portion of the first base is introduced, and the first A grid-like second slit communicated with the double clay introduction hole, and
Between the outer peripheral surface of the convex portion of the first base and the inner peripheral surface of the annular second base, there is a gap portion for extruding the clay in an annular shape,
A net member disposed between the first base and the second base; and through the mesh of the net member, the first clay introduction hole and the second clay introduction hole A die for forming a honeycomb structure configured to move the clay between each other.

[2] The honeycomb structure forming die according to [1], wherein the shape of the first slit is different from the shape of the second slit.

[3] The die for forming a honeycomb structure according to the above [1] or [2], wherein the wire constituting the mesh member has a diameter of 0.030 to 0.500 mm.

[4] The die for forming a honeycomb structure according to any one of [1] to [3], wherein the number of meshes per 1 cm of the mesh member is 3.9 to 130.

[5] Two or more mesh members are provided, and the mesh member disposed between the first die and the second die is exchanged, whereby the first die and the die in the extrusion direction are exchanged. The die for forming a honeycomb structure according to any one of [1] to [4], wherein the distance between the second die is changeable.

[6] The honeycomb according to any one of [1] to [5], including two or more types of the second bases having different shapes of the second slits and configured to be able to exchange the second bases. Base for structure molding.

[7] The ratio of the area of the central portion of the first die to the area of the end face of the honeycomb formed body to be extruded is 30 to 70%, according to any one of [1] to [6]. A die for forming a honeycomb structure.

[8] The slits surrounding one cell of the first slit and the slit surrounding one cell of the second slit extend in a direction crossing each other. 7] The die for forming a honeycomb structure according to any one of [7].

[9] The arrangement direction of the cell structure of the honeycomb molded body extruded by the first slit and the arrangement direction of the cell structure of the honeycomb molded body extruded by the second slit extend in directions intersecting each other. The honeycomb structure forming die according to any one of [1] to [8].

[10] An annular space securing member disposed between the first mouthpiece and the second mouthpiece is further provided, and the mesh member is disposed on an inner portion of the annular space securing member. The die for forming a honeycomb structure according to any one of [1] to [9].

[11] In the first base, the opening diameter of the first clay introduction hole and the interval between the first clay introduction holes are the same in the central portion and the outer peripheral portion. The die for forming a honeycomb structure according to any one of [1] to [10].

  The die for forming a honeycomb structure of the present invention includes a first die having a convex portion whose central portion on the clay discharge surface side protrudes toward the downstream side in the extrusion direction of the clay, and a convex portion of the first die. And an annular second base having a complementary shape. The honeycomb structure forming die of the present invention is further characterized by further comprising a “net-like member” disposed between the first die and the second die. By disposing such a mesh member, the first clay is formed between the downstream surface of the outer periphery of the first base and the upstream surface of the second base due to the mesh of the mesh member. A flow path is formed in which the clay is moved between the introduction hole and the second clay introduction hole.

  According to the die for forming a honeycomb structure of the present invention, a honeycomb formed body in which the cell structure is different between the central portion and the outer peripheral portion can be formed with high quality. That is, in the honeycomb structure forming die of the present invention, the first clay introduction hole and the second clay introduction hole communicate with each other through the mesh of the mesh member. Therefore, even if the positions of the first clay introduction hole of the first die and the second clay introduction hole of the second die do not coincide with each other in the extrusion direction, The clay is moved between the first clay introduction hole and the second clay introduction hole. In particular, since the movement of the clay is also performed between the meshes of the mesh member except for the portion where the wire rods of the mesh member are overlapped, when the clay is moved via the mesh, the second clay introduction hole is provided. The flow distribution of dredged soil introduced can be equalized. Therefore, according to the honeycomb structure forming die of the present invention, the discharge amount of the clay from the second slit of the second die is equalized, and the honeycomb formed body can be formed with high quality.

  Moreover, according to the die for forming a honeycomb structure of the present invention, even when back pressure (Back Pressure) is generated in the die when the die is changed or when ram molding is stopped, deformation of the second die is effective. Can be suppressed.

  Furthermore, in the die for forming a honeycomb structure of the present invention, since the mesh member is a separate member independent of the first die and the second die, the size of the space formed by the mesh member is easily changed. be able to. That is, the distance in the extrusion direction of the space can be adjusted by changing the thickness of the mesh member. And the quantity of the clay introduced into the clearance gap part for extruding a boundary wall can be adjusted by adjusting the distance of the extrusion direction of space. For example, when the type of clay is changed, or when the second base is replaced with another second base having a different shape of the second slit, the amount of clay introduced into the gap is appropriately set. By adjusting, the honeycomb formed body can be formed with high quality. The die for forming a honeycomb structure of the present invention is extremely excellent in versatility.

1 is a plan view schematically showing a clay discharge surface side of one embodiment of a die for forming a honeycomb structure of the present invention. FIG. 2 is a plan view of the honeycomb structure forming die shown in FIG. FIG. 2 is a plan view of the first base constituting the honeycomb structure forming die shown in FIG. 1 on the clay discharge surface side. FIG. 3 is a plan view of the second base constituting the honeycomb structure forming base shown in FIG. 1 on the side of the clay discharge surface. FIG. 2 is a plan view of the second die constituting the honeycomb structure forming die shown in FIG. FIG. 2 is a plan view of a mesh member constituting the honeycomb structure forming die shown in FIG. 1. FIG. 2 is a cross-sectional view schematically showing an A-A ′ cross section of the die for forming a honeycomb structure shown in FIG. 1. It is the expanded sectional view which expanded a part of FIG. FIG. 9 is an enlarged cross-sectional view illustrating a state in which the mesh member is replaced in the honeycomb structure forming die illustrated in FIG. 8. FIG. 3 is a perspective view schematically showing an example of a honeycomb structure manufactured by the die for forming a honeycomb structure of the present invention. It is a top view which shows typically the inflow end surface of the honeycomb structure shown in FIG. It is sectional drawing which shows typically the B-B 'cross section of FIG. FIG. 6 is a plan view schematically showing a clay discharge surface side of another embodiment of a die for forming a honeycomb structure of the present invention. FIG. 5 is a plan view schematically showing a net-like member and a space securing member used in still another embodiment of a die for forming a honeycomb structure of the present invention.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be specifically described with reference to the drawings. The present invention is not limited to the following embodiments, and it is understood that design changes, improvements, and the like can be added as appropriate based on the ordinary knowledge of those skilled in the art without departing from the spirit of the present invention. Should.

(1) Die for forming honeycomb structure:
An embodiment of a die for forming a honeycomb structure of the present invention will be described. Here, FIG. 1 is a plan view schematically showing the clay discharge surface side of one embodiment of the die for forming a honeycomb structure of the present invention. FIG. 2 is a plan view of the honeycomb structure forming die shown in FIG. FIG. 3 is a plan view of the first base constituting the honeycomb structure forming die shown in FIG. Fig. 4 is a plan view of the second die constituting the honeycomb structure forming die shown in Fig. 1 on the side of the clay discharge surface. FIG. 5 is a plan view of the second die constituting the honeycomb structure forming die shown in FIG. FIG. 6 is a plan view of a mesh member constituting the die for forming a honeycomb structure shown in FIG. FIG. 7 is a cross-sectional view schematically showing an AA ′ cross section of the honeycomb structure forming die shown in FIG. 1. FIG. 8 is an enlarged cross-sectional view in which a part of FIG. 7 is enlarged. In FIGS. 3, 5, and 6, the surfaces of the first base, the second base, and the mesh member are indicated by hatching.

  As shown in FIGS. 1 to 8, the honeycomb structure forming die 100 of this embodiment includes a first die 10, a second die 20, and a mesh member 30. The first die 10 is disposed on the upstream side in the extrusion direction X of the clay as a forming raw material, and the central portion 15 on the clay discharge surface 18 side has a convex portion 16 protruding toward the downstream side in the extrusion direction. . The second base 20 is an annular base disposed on the downstream side of the first base 10 and having a shape complementary to the convex portion 16 of the first base 10. The mesh member 30 is disposed between the first base 10 and the second base 20. The mesh member 30 is used to form a space between a downstream surface (downstream surface 14) in the outer peripheral portion 17 of the first base 10 and an upstream surface (upstream surface 24) of the second base 20. It functions as a spacer. Hereinafter, the honeycomb structure forming die 100 of the present embodiment may be simply referred to as “die 100”. The extrusion direction X of the clay is an extrusion direction at the time of extrusion molding using the die 100 of the present embodiment, and is a direction from the clay introduction surface 19 toward the clay discharge surface 18.

  In the base 100 of the present embodiment, a first clay introduction hole 12 and a lattice-shaped first slit 11 communicating with the first clay introduction hole 12 are formed in the central portion 15 of the first base 10. Has been. The first clay introduction hole 12 is formed coaxially with the intersection of the lattice-shaped first slits 11 and the extrusion direction X. That is, the first clay introduction hole 12 communicates with the intersection of the lattice-shaped first slits 11. A first clay introduction hole 12 is formed in the outer peripheral portion 17 surrounding the central portion 15 of the first base 10 so as to penetrate the outer peripheral portion 17 of the first base 10.

  In the annular second base 20, a second clay introduction hole 22 into which the clay discharged from the first clay introduction hole 12 formed in the outer peripheral portion 17 of the first base 10 is introduced, and the first A grid-like second slit 21 communicating with the birch soil introduction hole 22 is formed. The second clay introduction hole 22 is formed coaxially with the intersection of the grid-like second slits 21 and the extrusion direction X. That is, the second clay introduction hole 22 communicates with the intersection of the grid-like second slits 21. In the base 100 of the present embodiment, the opening position of the first clay introduction hole 12 in the outer peripheral portion 17 of the first base 10 and the opening position of the second clay introduction hole 22 in the second base 20 are as follows. , At least partly does not match.

  In the base 100 of this embodiment, the first base 10 and the second base 20 are combined so as to sandwich the mesh member 30. Hereinafter, the downstream end face in the extrusion direction X of the outer peripheral portion 17 of the first base 10 is referred to as “downstream surface 14 in the outer peripheral portion 17 of the first base 10”, and the extrusion direction X of the annular second base 20. The upstream end face of the base plate may be referred to as “upstream face 24 of the second cap 20”. Further, hereinafter, the term “upstream” simply means the upstream side in the extrusion direction X, and the term “south” simply means the downstream side in the extrusion direction X.

  The base 100 of the present embodiment includes a first clay introduction hole 12 and a second clay introduction hole between the downstream surface 14 of the outer peripheral portion 17 of the first base 10 and the upstream surface 24 of the second base 20. 22, a flow path 31 formed by the mesh of the mesh member 30 for moving the clay is provided. 6-8, the code | symbol 33 shows the wire 33 which comprises the net-like member 30. FIG. As shown in FIG. 6, a central portion of the mesh member 30 has a gap portion 36 in which a portion corresponding to the convex portion 16 of the first base 10 is hollowed out in a circular shape.

  The base 100 of the present embodiment has a gap portion 55 for extruding the clay in an annular shape between the outer peripheral surface of the convex portion 16 of the first base 10 and the inner peripheral surface of the annular second base 20. Have That is, in the base 100 of the present embodiment, the gap portion 26 in the central portion 25 of the second base 20 is formed slightly larger than the peripheral edge of the convex portion 16 of the first base 10. With this configuration, when the convex portion 16 of the first base 10 is combined so as to be inserted into the gap portion 26 of the annular second base 20, An annular gap 55 is formed between the two caps 20. The annular gap portion 55 becomes a gap portion 55 for forming the boundary wall of the honeycomb formed body. In the present invention, the “annular second base 20 having a shape complementary to the convex portion 16 of the first base 10” means an annular shape having a gap 26 slightly larger than the convex portion 16 of the first base 10. It means a clasp.

  In the base 100 of this embodiment, the end face on the upstream side in the extrusion direction X of the first base 10 is a clay introduction surface 19 of the whole base 100. Therefore, at the time of extrusion molding, the clay as a forming raw material is first introduced into the first clay introduction hole 12 opened in the clay introduction surface 19 of the first base 10. The clay introduced into the first clay introduction hole 12 in the central portion 15 of the first base 10 moves to the lattice-shaped first slit 11 communicating with the first clay introduction hole 12, and the first mouth From the gold clay discharge surface 18, it is discharged as a molded body corresponding to the shape of the first slit 11. On the other hand, the clay introduced into the first clay introduction hole 12 of the outer peripheral portion 17 of the first base 10 is discharged from the downstream surface 14 side of the first base 10 and passes through the mesh of the mesh member 30. The second base 20 is introduced into the second clay introduction hole 22. For this reason, even if the positions of the first clay introduction hole 12 of the first base 10 and the second clay introduction hole 22 of the second base 20 do not coincide with each other, the first clay introduction hole 12 and the second clay introduction hole 12 are the same. The clay is moved well between the clay introduction holes 22. The mesh member 30 is formed, for example, by knitting the wire material 33 extending in the horizontal direction and the wire material 33 extending in the vertical direction, and therefore the mesh of the mesh member 30 except for the portion where the knitted wire material 33 overlaps. The clay is also moved between the two. For this reason, when the clay is moved through the mesh of the mesh member 30, the flow rate distribution of the clay introduced into the second clay introduction hole 22 can be equalized. The clay introduced into the second clay introduction hole 22 of the second base 20 moves to the grid-like second slit 21 communicating with the second clay introduction hole 22, and the clay discharge surface of the second base 20 28, the molded product corresponding to the shape of the second slit 21 is discharged. Therefore, according to the die 100 of the present embodiment, the amount of clay discharged from the second slit 21 of the second die 20 is equalized, and the honeycomb formed body can be formed with high quality. Further, since the flow path 31 formed by the mesh of the mesh member 30 is also communicated with the gap portion 55 for extruding the clay in an annular shape, the first rib of the outer peripheral portion 17 of the first base 10 is formed. The clay introduced into the soil introduction hole 12 is also introduced into the gap portion 55 via the mesh of the mesh member 30. Therefore, the flow rate distribution of the clay introduced into the gap portion 55 can be equalized, and the occurrence of molding defects around the boundary wall of the honeycomb formed body to be extruded can be particularly effectively suppressed. For this reason, the die 100 according to the present embodiment can form a high-quality honeycomb molded body having a different cell structure between the central portion and the outer peripheral portion and having a boundary wall at the boundary between the central portion and the outer peripheral portion. .

  In the present specification, the “cell structure” means a structure of a honeycomb structure defined by partition wall thickness, cell density, and cell shape. Further, the “slit shape” means the shape of the slit defined by the width, depth, length of the slit formed in the die and the connection form of the slits.

  Further, if a net member 30 is not provided between the first base 10 and the second base 20 and a space is provided between the first base 10 and the second base 20, the second base 20 becomes a state like a cantilever. As described above, if the second base 20 is in a cantilever state, the second base 20 is deformed when back pressure is generated in the base 100 when the base is replaced or when the ram molding is stopped. May end up. In the base 100 of the present embodiment, since the mesh member 30 is disposed between the first nozzle 10 and the second nozzle 20, the back pressure generated in the second nozzle 20 is received by the mesh member 30, and the back The pressure can be dispersed.

  Further, although not shown, in the base of this embodiment, several types of second bases having different second slit shapes are separately prepared, and the second base is replaced in accordance with the cell structure of the honeycomb formed body to be formed. Can also be used. Since the second clay introduction hole of the second die is formed coaxially with the intersection of the grid-like second slit and the extrusion direction, the opening of the second clay introduction hole on the upstream surface of the second die The position differs depending on the shape of the second slit of the second base. Even when a second base having a different shape of the second slit is used, the movement of the clay in the base is hindered by disposing a mesh member between the first base and the second base. Therefore, it is possible to always achieve uniform extrusion molding between the central portion and the outer peripheral portion.

  Further, in the base 100 of the present embodiment, since the mesh member 30 is a separate member independent of the first nozzle 10 and the second nozzle 20, the thickness of the mesh member 30 can be changed by replacing the mesh member 30. The mesh size can be easily changed. For example, the distance in the extrusion direction X between the first die 10 and the second die 20 can be adjusted by changing the thickness of the mesh member 30 in the extrusion direction X. The amount of clay introduced into the gap 55 can be adjusted by adjusting the distance in the extrusion direction X described above. For example, using a mesh member 30A as shown in FIG. 9, the distance between the first die 10 and the second die 20 and the extrusion direction X can be adjusted. A mesh member 30A shown in FIG. 9 is a mesh member 30A formed using a wire 33A having a diameter larger than that of the wire 33 of the mesh member 30 shown in FIG. Here, FIG. 9 is an enlarged cross-sectional view showing a state in which the mesh member is replaced in the honeycomb structure forming die shown in FIG. In the base 100 shown in FIG. 9, the same components as those of the base 100 shown in FIG. 8 are denoted by the same reference numerals as those in FIG. In FIG. 9, reference numeral 31A indicates a flow path formed by the mesh of the mesh member 30A.

  For example, when the base 100 shown in FIG. 8 is used, if the type of the clay as a forming raw material is changed, the fluidity of the clay changes, and the flow rate distribution of the clay introduced into the gap 55 changes. There is. For this reason, when the kind of clay is changed, the balance of the clay consumption of the second slit 21 and the gap 55 may be lost. In addition, when the second base 20 is replaced with another second base (not shown) having a different shape of the second slit, the amount of clay discharged from the second slit 21 of the second base 20 is reduced. The balance of the clay consumption of the second slit 21 and the gap 55 may be lost. When the balance of the clay consumption of the second slit 21 and the gap portion 55 is lost, the thickness of the mesh member 30 is adjusted, and the amount of clay introduced into the gap portion 55 is adjusted. In addition, it is possible to effectively suppress the occurrence of molding defects around the boundary wall of the honeycomb formed body. In addition to adjusting the thickness of the mesh member 30, for example, the size of the mesh of the mesh member 30 can be adjusted to adjust the amount of clay introduced into the gap portion 55. The base 100 according to the present embodiment can adjust the thickness of the mesh member 30 and the size of the mesh, even when changing the type of clay or changing the second base. The soil flow distribution can be made appropriate. Therefore, the base 100 of the present embodiment has not only the effect of allowing the second base to be changed, but also a particularly remarkable effect of being extremely versatile.

  Here, the honeycomb structure manufactured by the die for forming a honeycomb structure of the present embodiment will be described. FIG. 10 is a perspective view schematically showing an example of a honeycomb structure manufactured by the honeycomb structure forming die of the present invention. FIG. 11 is a plan view schematically showing the inflow end face of the honeycomb structure shown in FIG. 12 is a cross-sectional view schematically showing a B-B ′ cross section of FIG. 11.

  A honeycomb structure 200 shown in FIGS. 10 to 12 includes a columnar honeycomb structure 204 having a porous partition wall 201 and an outer peripheral wall 203 disposed so as to surround the outer periphery of the partition wall 201. Is. The partition walls 201 of the honeycomb structure portion 204 partition and form a plurality of cells 202 serving as fluid flow paths extending from the inflow end surface 211 to the outflow end surface 212. The honeycomb structure portion 204 includes a central cell structure 215, an outer peripheral cell structure 216, and a boundary wall 208 disposed at a boundary portion between the outer peripheral cell structure 216 and the central cell structure 215. In the honeycomb structure portion 204, the central cell structure 215 and the peripheral cell structure 216 are different cell structures.

  Here, the central cell structure 215 is a cell structure constituted by a plurality of cells 202a formed in the central portion of the honeycomb structure portion 204 in a plane orthogonal to the extending direction of the cells 202 of the honeycomb structure portion 204. is there. The peripheral cell structure 216 is a cell structure constituted by a plurality of cells 202b formed closer to the outer periphery than the central portion of the honeycomb structure portion 204 in the above surface.

  The “cell structure” means that one of the cells 202 or a combination of a plurality of cells 202 partitioned by the partition wall 201 is one repeating unit in a plane orthogonal to the extending direction of the cells 202, A structure formed by a set. For example, when cells having the same shape are regularly arranged on the above surface, a range in which cells having the same shape exist becomes one cell structure. In addition, even in the case of cells having different cell shapes, when a combination of a plurality of cells becomes one repeating unit, a range where the repeating unit exists becomes one cell structure.

The two cell structures being “different cell structures” means that any one of the partition wall thickness, cell density, and cell shape is different when the two cell structures are compared. Here, “different partition wall thicknesses” means having a difference of 25 μm or more when the partition wall thicknesses of two cell structures are compared. Further, “different cell densities” means having a difference of 7 cells / cm ² or more when the cell densities of two cell structures are compared.

  The die of the present embodiment can be suitably used for forming a honeycomb formed body for manufacturing a honeycomb structure 200 as shown in FIGS. Hereinafter, the more suitable form of the nozzle | cap | die of this embodiment is demonstrated.

  As shown in FIGS. 1 to 8, the base of the present embodiment is preferably such that the shape of the first slit 11 and the shape of the second slit 21 are different. There is no restriction | limiting in particular about the shape of the 1st slit 11, and the shape of the 2nd slit 21, According to the cell structure of the honeycomb molded object to shape | mold, it can select suitably. Moreover, the 2nd nozzle | cap | die 20 from which the shape of the 2nd slit 21 differs may be provided, and the 2nd nozzle | cap | die 20 may be comprised so that replacement | exchange is possible. Further, two or more first caps 10 having different shapes of the first slits 11 may be provided, and the first cap 10 may be configured to be replaceable.

  The mesh member 30 can include a mesh member formed by knitting a plurality of wire rods 33. However, the mesh member 30 may be a mesh member configured such that the portion where the mesh intersects is thick and the other portion is relatively thinner than the intersecting portion. For example, the mesh member 30 may be a mesh member in which a plurality of wires 33 are integrally formed in advance by molding or the like. As a substitute for the mesh member, a perforated member such as a punching plate having a plurality of holes perforated on the plate member can be used. However, since such a perforated member is a hole in which each hole is independently formed, it is difficult to move the clay between the plurality of holes. For this reason, a perforated member such as a punching plate is less likely to achieve the effect of equalizing the flow distribution of the clay than the mesh member 30 of the base 100 of the present embodiment.

  There is no restriction | limiting in particular about the diameter of the wire 33 which comprises the net-like member 30, For example, it is preferable that it is 0.030-0.500 mm. If the diameter of the wire rod 33 is less than 0.030 mm, the thickness of the mesh member 30 becomes too thin, and it may be difficult to equalize the flow distribution of the clay. Moreover, the wire 33 may become thin and the strength of the mesh member 30 may decrease. When the diameter of the wire 33 exceeds 0.500 mm, the mesh becomes too large with respect to the clay introduction hole, and thus a flow velocity difference is generated in each introduction hole, which is not preferable in terms of deterioration of moldability. Note that the thickness of the mesh member 30 is approximately twice the diameter of the wire 33 described above.

  There is no particular limitation on the size of the mesh of the mesh member 30. For example, the number of meshes per cm is preferably 3.9 to 130. When the number of meshes per 1 cm is less than 3.9, the strength of the mesh member 30 is lowered, and the mesh member 30 may be easily deformed. In particular, when the diameter of the wire 33 is small, the deformation of the mesh member 30 becomes more remarkable. On the other hand, when the number of meshes per 1 cm exceeds 130, the mesh of the mesh member 30 becomes too dense, and the resistance when the clay passes may increase. Further, as the number of meshes per 1 cm increases, the diameter of the wire 33 that can be used is limited, and accordingly, the upper limit of the thickness of the mesh member 30 is limited.

  The base 100 of this embodiment may be provided with two or more mesh members 30. For example, as shown in FIGS. 8 and 9, two or more mesh members 30, 30A having different thicknesses may be prepared in advance. And according to the molding conditions at the time of extrusion molding, the one having the optimum distance between the first die 10 and the second die 20 and the extrusion direction X is appropriately selected from the two or more mesh members 30 and 30A. May be used. Moreover, although illustration is abbreviate | omitted, two or more mesh members may differ in the number of meshes per cm, in other words, the size of the meshes.

  Regarding the ratio of the area of the central portion 15 of the first die 10 to the area of the end face of the honeycomb molded body to be extruded, the cell structure (for example, FIGS. 10 to 12) It can be appropriately determined according to the reference). In the base of the present embodiment, the ratio is preferably 30 to 70%, particularly preferably 40 to 60%.

  As described above, in the base 100, the gap portion 26 in the central portion 25 of the second base 20 is formed slightly larger than the peripheral edge of the convex portion 16 of the first base 10, and the convex portion of the first base 10. An annular gap 55 is formed between 16 and the second cap 20. There is no restriction | limiting in particular about the space | interval of the cyclic | annular clearance gap 55 mentioned above, According to the thickness of the boundary wall of the honeycomb molded object to shape | mold, it can select suitably. For example, the interval between the annular gaps 55 is preferably 0.04 to 0.50 mm.

  As for the 1st nozzle | cap | die 10, it is preferable in the center part 15 and the outer peripheral part 17 that the opening diameter of the 1st clay introduction hole 12 and the space | interval between each 1st clay introduction hole 12 are the same. . By comprising in this way, the 1st nozzle | cap | die 10 can be manufactured simply and at low cost, for example.

  The base of the present embodiment may extend in a direction in which a slit surrounding one cell of the first slit and a slit surrounding one cell of the second slit intersect each other. . Here, the “cell” means a space defined by partition walls in the honeycomb formed body to be formed. For example, the base 300 shown in FIG. 13 is manufactured such that the first slit 11 of the first base 10 is rotated 45 ° clockwise with respect to the base 100 shown in FIG. For this reason, in the base 300, the slit surrounding one cell of the first slit 11 and the slit surrounding one cell of the second slit 21 do not have a parallel positional relationship. As described above, the base of the present embodiment can equalize the flow rate distribution of the clay even when the slits surrounding each cell intersect each other in the first slit and the second slit. Therefore, the discharge amount of the clay from the second slit of the second die is equalized, and the honeycomb formed body can be formed with high quality.

  As shown in FIG. 1, the die 100 of the present embodiment includes an arrangement direction of the cell structure of the honeycomb formed body extruded by the first slit 11 and an arrangement of the cell structure of the honeycomb formed body extruded by the second slit 21. The direction is parallel. That is, the direction in which the first slit 11 of the first base 10 extends and the direction in which the second slit 21 of the second base 20 extends are parallel to each other. However, as in the base 300 shown in FIG. 13, the arrangement direction of the cell structure of the honeycomb formed body extruded by the first slit 11 and the arrangement direction of the cell structure of the honeycomb formed body extruded by the second slit 21 , And may extend in directions crossing each other. FIG. 13 is a plan view schematically showing the clay discharge surface side of another embodiment of the die for forming a honeycomb structure of the present invention. In the base 300 shown in FIG. 13, the same components as those of the base 100 shown in FIG.

  Also in the base 300 shown in FIG. 13, a mesh member 30 (see FIG. 8) is provided between the first base 10 and the second base 20. Therefore, even when the direction in which the first slit 11 of the first base 10 extends and the direction in which the second slit 21 of the second base 20 extends intersect each other as in the base 300 shown in FIG. The flow distribution of dredged soil can be equalized. Therefore, the discharge amount of the clay from the second slit 21 of the second base 20 is equalized, and the honeycomb formed body can be formed with high quality.

  A base 300 shown in FIG. 13 is manufactured in advance so that the first slit 11 of the first base 10 is rotated 45 ° clockwise. However, for example, in the base 100 shown in FIG. 1, the first base 10 can be rotated 45 ° clockwise and used. Even when the first base 10 of the base 100 shown in FIG. 1 is rotated clockwise by 45 °, as shown in FIGS. 7 and 8, a mesh member is provided between the first base 10 and the second base 20. Since 30 exists, the movement of the clay in the base 100 is not hindered. For example, in the conventional base that does not include the mesh member 30, the first clay introduction hole of the first base and the second clay introduction hole of the second base coincide with each other in the extrusion direction of the clay. Designed. For this reason, when only the 1st nozzle | cap | die is rotated and used, the movement of the clay in a nozzle | cap | die will be inhibited.

  In the base of the present embodiment as shown in FIGS. 1 to 8, the thickness of the first base 10, the protruding height of the convex portion 16 of the first base 10, and the thickness of the second base 20 are particularly important. There is no limit. As thickness of the 1st nozzle | cap | die 10, it is preferable that it is 10-50 mm. The protruding height of the convex portion 16 of the first base 10 is preferably 10 to 30 mm. The thickness of the second base 20 is preferably 10 to 30 mm. In addition, the protrusion height of the convex part 16 of the 1st nozzle | cap | die 10, and the thickness of the 2nd nozzle | cap | die 20 may be the same, and may differ. For example, when the convex portion 16 of the first base 10 is inserted into the gap portion 26 of the annular second base 20, the position of the clay discharge surface 18 of the first base 10, and the second base 20 The position of the clay discharge surface 28 may or may not match.

  The base of the present invention may further include an annular space securing member 40 as shown in FIG. Here, FIG. 14 is a plan view schematically showing a net-like member and a space securing member used in still another embodiment of the honeycomb structure forming die of the present invention. The space securing member 40 has a space 41 formed in the central portion of the space securing member 40 by hollowing out the central portion of the base material 43 in a circular shape. The space securing member 40 is disposed and used between the first base 10 (see FIG. 8) and the second base 20 (see FIG. 8). Therefore, the space securing member 40 is a spacer (a spacer for forming a space between the downstream surface (downstream surface) and the upstream surface (upstream surface) of the second base. function as a spacer). In the inner portion of the space securing member 40, that is, in the space 41 formed in the base material 43, the mesh member 30 as described above is preferably disposed. The mesh member 30 shown in FIG. 14 has, for example, a donut shape in which the outer peripheral portion of the mesh member 30 shown in FIG. 6 is circular. In FIG. 14, the donut-shaped mesh member 30 is accommodated in the space 41 of the space securing member 40, and both the mesh member 30 and the space securing member 40 are connected to the first cap 10 (FIG. 8). And the second base 20 (see FIG. 8).

  By further providing a space securing member 40 as shown in FIG. 14, the compressive stress applied to the mesh member 30 at the time of extrusion molding can be relaxed, and deformation and breakage of the mesh member 30 can be effectively suppressed. . The mesh member 30 shown in FIG. 14 is preferably configured in the same manner as the mesh member 30 shown in FIG. 6 except that the mesh member 30 shown in FIG. 6 has a circular donut shape. In the mesh member 30 shown in FIG. 14, the same components as those of the mesh member 30 shown in FIG.

  As the material of the first die base 13 constituting the first die 10 and the second die base 23 constituting the second die 20, it is generally used as a die material for forming a honeycomb structure. Mention may be made of metals or alloys. Hereinafter, the first base material and the second base material may be collectively referred to simply as “base material”. For example, as a base material, a metal containing at least one metal selected from the group consisting of iron (Fe), titanium (Ti), nickel (Ni), copper (Cu), and aluminum (Al) or Mention may be made of alloys.

  As an example of the alloy used as the material of the die base material, a stainless alloy, more specifically, SUS630 can be given. Such a stainless alloy is an inexpensive material that is relatively easy to process. Further, other examples of the alloy constituting the die base material include a tungsten carbide base cemented carbide having excellent wear resistance. By using a base material made of a tungsten carbide base cemented carbide or the like, a die for forming a honeycomb structure with less wear of the slit can be manufactured.

  The material of the mesh member 30 is not particularly limited, and examples thereof include various metals or alloys.

  There is no restriction | limiting in particular about the method of manufacturing the nozzle | cap | die of this embodiment. For example, the base of the present embodiment can be manufactured according to a conventionally known base manufacturing method.

  For the first clay introduction hole and the second clay introduction hole, known machining such as drilling, electric discharge machining, electrolytic machining, and laser machining is used for the first die base material and the second die base material. Can be formed.

  About a 1st slit base and a 2nd slit, it can form using well-known machining processes, such as grinding, electrical discharge machining, electrolytic processing, and laser processing, with respect to a 1st base material and a 2nd base material.

  The convex part which comprises the center part of a 1st nozzle | cap | die can be formed by grinding, electric discharge machining, or joining of 2 members.

  The mesh member is manufactured, for example, by preparing a wire mesh produced by knitting a plurality of wire rods, and drilling a hole having a size corresponding to the convex portion of the first die in the central portion of the prepared wire mesh. be able to.

  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
In Example 1, a die for manufacturing a honeycomb structure 200 having a cell structure in which the central cell structure 215 and the peripheral cell structure 216 of the honeycomb structure portion 204 as shown in FIGS. 10 to 12 are different was manufactured. More specifically, in Example 1, a die was manufactured so that the honeycomb structure as a final product was a honeycomb structure configured as follows. The honeycomb structure as a final product has a columnar shape with an end face diameter of 100 mm, and the central cell structure on the end face has a diameter of 70 mm. A boundary wall having a thickness of 0.1 mm is provided at the boundary between the central cell structure and the peripheral cell structure. The central cell structure has a square cell shape, a partition wall thickness of 0.09 mm, and a cell density of 93 cells / cm ² . The peripheral cell structure has a square cell shape, a partition wall thickness of 0.11 mm, and a cell density of 62 cells / cm ² . In addition, manufacturing tolerance is not included about each dimension in said honeycomb structure.

  First, in Example 1, a plate-shaped first die base material having a length of 200 mm, a width of 200 mm, and a thickness of 20 mm was prepared. The base material for the base was made of stainless steel. One surface of the prepared first die base material was used as a clay discharge surface, and a convex portion was formed in the central portion on the clay discharge surface side by an electric discharge machining so that the protrusion length was 10 mm.

  Next, a grid-like first slit was formed on the clay discharge surface of the convex portion of the first die base. The lattice-shaped first slit was formed into a slit shape capable of extruding the partition walls constituting the central cell structure of the honeycomb structure as the final product described above. The first slit was formed by grinding.

  Next, a first clay introduction hole having an opening diameter of 1.2 mm was formed on the clay introduction surface of the first die base so as to communicate with the intersection of the first slits. Moreover, about the 1st nozzle | cap | die base material, the 1st clay introduction hole was formed with the same pitch as the center part which has a convex part also about the outer peripheral part which does not have a convex part. The first clay introduction hole in the outer peripheral portion of the first base material was a through hole that communicated from the clay introduction surface of the first base material to the downstream surface of the outer periphery. As described above, the first die in the die of Example 1 was produced.

  Next, a plate-shaped second die base material having a length of 200 mm, a width of 200 mm, and a thickness of 10 mm was prepared. The base material for the base was made of stainless steel. The central portion of the prepared second base material was cut into a circular shape, so that the second base material was annular.

  Next, a grid-like second slit was formed on the clay discharge surface of the convex portion of the second die base material. The grid-like second slit was formed into a slit shape capable of extruding the partition walls constituting the peripheral cell structure of the honeycomb structure as the final product described above. The formation of the second slit was performed by grinding.

  Next, a second clay introduction hole having an opening diameter of 1.2 mm was formed on the surface of the second die base material opposite to the clay discharge surface so as to communicate with the intersection of the second slits.

  Next, a wire net produced by knitting a wire rod having a diameter of 0.2 mm so that the number of meshes per cm was 7 was prepared. This wire mesh was made of stainless steel. A central portion of the prepared wire mesh was cut into a circular shape having a diameter of 80 mm, and a mesh member having a space in a portion corresponding to the central portion of the first base was produced.

  Next, in a state where the mesh member is arranged on the clay discharge surface side outside the outer peripheral part of the first base, the convex part of the central part of the first base is formed in the gap part of the central part of the second base. The base of Example 1 was manufactured such that the mesh member was sandwiched between the first base and the second base as inserted.

  Table 1 shows “the base structure”, “the pitch of the second slit (mm)”, and “the interval between the gaps for forming the boundary part (mm)”. Table 1 shows the “presence / absence” of the mesh member, the “diameter (mm) of wire” constituting the mesh member, and the “number of meshes per 1 cm” of the mesh member. In addition, in the “base structure” column, the “two-body assembly” is used for manufacturing one base by combining the first base and the second base so that the net-like member is sandwiched as in the base of Example 1. ". On the other hand, a base manufactured by making the slit shape different between the central portion and the outer peripheral portion with respect to one base material is referred to as “integrated structure” in the “base structure” column.

  The total work time required for manufacturing the die of Example 1 was 70 hours. Using the die of Example 1, “molded product quality” and “presence / absence of deformation of the second die” were evaluated by the following methods. The results are shown in Table 1.

[Molded product quality]
A honeycomb structure having a cordierite composition was extruded using the produced die. The extruded honeycomb structure was visually confirmed, and the quality of the honeycomb structure was evaluated according to the following evaluation criteria. A case where there is no appearance defect is defined as “good”. The case where the appearance is poor or the case where molding is impossible is defined as “impossible”. Here, “exterior appearance” means that the partition walls constituting the honeycomb structure are curved due to variations in extrusion speed at each part of the die.

[The presence or absence of deformation of the second cap]
Using the produced die, extrusion molding under the same conditions as the evaluation of the molded product quality was performed three times, and when the extrusion molding was completed, the presence or absence of deformation of the second die was visually confirmed. The case where deformation is confirmed in the second base is “present”, and the case where deformation is not confirmed in the second base is “not present”.

(Examples 2 and 3)
In the same manner as in Example 1, except that the “wire diameter (mm)” and “number of meshes per 1 cm (pieces)” of the mesh member were changed to values as shown in Table 1. Manufactured. Using the caps of Examples 2 and 3, evaluation of “molded product quality” and “presence / absence of deformation of second cap” was performed in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Example 1)
In Comparative Example 1, a plate-shaped die base material having a length of 200 mm, a width of 200 mm, and a thickness of 20 mm was prepared. The base material for the base was made of stainless steel. One surface of the prepared base material was used as a clay discharge surface, and a slit having the same shape as the first slit of the base of Example 1 was formed in the central portion on the clay discharge surface side. Next, a slit having the same shape as the second slit of the base of Example 1 was formed on the outer peripheral portion of the base material on the clay discharge surface side. Next, an annular slit was formed at the position corresponding to the gap in Example 1 to join the ends of the first slit and the second slit. Next, a clay introduction hole having an opening diameter of 1.2 mm was formed so as to communicate with the intersection portion of each slit from the clay introduction surface side of the base material. The die of Comparative Example 1 was manufactured as described above.

  The total work time required for manufacturing the base of Comparative Example 1 was 100 hours. Using the die of Comparative Example 1, “molded product quality” and “presence / absence of deformation of second die” were evaluated in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Example 2)
In Comparative Example 2, first and second caps that were configured in the same manner as the first and second caps of the cap of Example 1 were prepared. Next, in Comparative Example 2, the convex portion of the central portion of the first base is inserted into the gap portion of the central portion of the manufactured second base, and the second base and the first base are combined. The base of Comparative Example 2 was manufactured. That is, in Comparative Example 2, the die was manufactured without arranging the mesh member between the first die and the second die.

  The total work time required for manufacturing the base of Comparative Example 2 was 70 hours. Using the die of Comparative Example 2, “molded product quality” and “presence / absence of deformation of second die” were evaluated in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Example 3)
In Comparative Example 3, first, a first base configured similarly to the first base of the base of Example 1 was produced. Next, in Comparative Example 3, a second die was prepared by removing a range of 0.1 mm in the extrusion direction from the upstream surface of the second die base material by grinding. The base part of Comparative Example 3 is manufactured by combining the second base part and the first base part so that the convex part of the central part of the first base part is inserted into the gap part of the central part of the second base part. did. The base of Comparative Example 3 is combined with the first base in a state where the downstream face of the outer periphery of the first base and the upstream face of the second base are not in contact with each other and the second base is like a cantilever. It was.

  The total work time required for manufacturing the base of Comparative Example 3 was 80 hours. Using the die of Comparative Example 3, “molded product quality” and “presence / absence of deformation of second die” were evaluated in the same manner as in Example 1. The results are shown in Table 1.

(result)
The bases of Examples 1 to 3 were able to shorten the manufacturing time as compared with the base of Comparative Example 1, and the evaluation of the quality of the molded product was also good. Moreover, the deformation | transformation of the 2nd nozzle | cap | die was not confirmed for the nozzle | cap | die of Examples 1-3.

  The base of Comparative Example 1 was not possible in the evaluation of the quality of the molded product. The reason for this is that if the shape of the slit is different between the central part and the outer peripheral part of the base, the distribution of the flow rate of the clay in the base is likely to be uneven, and the discharge amount of the clay from the slit is not uniform. It is presumed that. In particular, when extrusion molding was performed using the die of Comparative Example 1, the supply of clay for forming the boundary wall did not catch up, and many molding defects were confirmed at the boundary wall and its vicinity.

  In the base of Comparative Example 2, the movement of the clay is obstructed at a location where the positions of the first clay introduction hole of the first die and the second clay introduction hole of the second die do not match. In the evaluation of the quality of the molded product, it was impossible. Moreover, when extrusion molding was performed using the die of Comparative Example 2, the supply of the clay for forming the boundary wall could not catch up, and a molding defect was remarkably confirmed at the boundary wall and its vicinity.

  The base of Comparative Example 3 was good in evaluation of the quality of the molded product, but deformation of the second base was confirmed in the evaluation of the presence or absence of deformation of the second base. If the deformation of the second die becomes prominent, the quality of the molded product may be affected. Further, if the deformation of the second base is likely to occur, there is a concern that the manufacturing cost of the product increases with the replacement of the base.

  The die for forming a honeycomb structure of the present invention can be used for manufacturing a honeycomb formed body in which the cell structure is different between the central portion and the outer peripheral portion.

10: first base, 11: first slit, 12: first clay introduction hole, 13: first base material, 14: downstream surface (downstream surface of the outer periphery of the first base), 15: center portion , 16: convex part, 17: outer peripheral part, 18: clay discharge surface (soil discharge surface of the first base), 19: clay introduction surface, 20: second base, 21: second slit, 22: Second clay introduction hole, 23: second base material, 24: upstream surface (upstream surface of the second base), 25: central portion, 26: gap portion, 27: outer peripheral portion, 28: clay discharge surface ( (Soil discharge surface of second cap), 30, 30A: mesh member, 31, 31A: flow path, 33, 33A: wire rod, 36: gap portion, 40: space securing member, 41: space, 43: base material 55: Crevice part (gap part for forming boundary wall), 100, 300: Die for forming honeycomb structure (die), 201: partition wall, 202: cell, 202a: 202 (cell of central cell structure), 202b: cell (cell of outer peripheral cell structure), 203: outer peripheral wall, 204: honeycomb structure, 208: boundary wall, 211: inflow end surface, 212: outflow end surface, 215: central cell Structure: 216: peripheral cell structure, 200: honeycomb structure, X: extrusion direction.

Claims (11)

A first die having a convex portion that is disposed upstream of the extrusion direction of the clay as a forming raw material, and a central portion of the clay discharge surface side protrudes toward the downstream side of the extrusion direction;
An annular second base disposed on the downstream side of the first base and having a shape complementary to the convex portion;
In the central portion of the first base, a first clay introduction hole and a lattice-shaped first slit communicating with the first clay introduction hole are formed,
In the outer peripheral portion surrounding the central portion of the first base, the first clay introduction hole is formed so as to penetrate the outer peripheral portion of the first base,
In the annular second base, a second clay introduction hole into which the clay discharged from the first clay introduction hole formed in the outer peripheral portion of the first base is introduced, and the first A grid-like second slit communicated with the double clay introduction hole, and
Between the outer peripheral surface of the convex portion of the first base and the inner peripheral surface of the annular second base, there is a gap portion for extruding the clay in an annular shape,
A net member disposed between the first base and the second base; and through the mesh of the net member, the first clay introduction hole and the second clay introduction hole A die for forming a honeycomb structure configured to move the clay between each other.   The die for forming a honeycomb structure according to claim 1, wherein the shape of the first slit is different from the shape of the second slit.   The die for forming a honeycomb structure according to claim 1 or 2, wherein the wire constituting the mesh member has a diameter of 0.030 to 0.500 mm.   The die for forming a honeycomb structure according to any one of claims 1 to 3, wherein the number of meshes per 1 cm of the mesh member is 3.9 to 130.   The first cap and the second cap in the extruding direction are provided by exchanging the net member provided between the first cap and the second cap by providing two or more of the mesh members. The die for forming a honeycomb structure according to any one of claims 1 to 4, wherein a distance between the two can be changed.   The honeycomb structure molding according to any one of claims 1 to 5, comprising two or more types of the second bases having different shapes of the second slits, wherein the second bases are configured to be replaceable. Base.   The honeycomb structure according to any one of claims 1 to 6, wherein a ratio of an area of the central portion of the first die to an area of an end face of the honeycomb formed body to be extruded is 30 to 70%. Base for molding.   The slit surrounding one cell of the first slit and the slit surrounding one cell of the second slit extend in directions intersecting each other. A die for forming a honeycomb structure according to the item.   The arrangement direction of the cell structure of the honeycomb formed body extruded by the first slit and the arrangement direction of the cell structure of the honeycomb formed body extruded by the second slit extend in directions intersecting each other. Item 9. A die for forming a honeycomb structure according to any one of Items 1 to 8.   An annular space securing member disposed between the first mouthpiece and the second mouthpiece is further provided, and the mesh member is disposed on an inner portion of the annular space securing member. Item 10. A die for forming a honeycomb structure according to any one of Items 1 to 9.   The first base has an opening diameter of the first clay introduction hole and an interval between the first clay introduction holes in the central portion and the outer peripheral portion, respectively. The die for forming a honeycomb structure according to any one of 1 to 10.

Images