JP7567686B2 - Mold and method for manufacturing mold - Google Patents

Description

The present invention relates to a molding die and a manufacturing method for manufacturing the molding die.

The following Patent Document 1 discloses a molding die of this type, called a honeycomb structure molding die. This honeycomb structure molding die comprises a first plate-shaped member having a back hole penetrating in the thickness direction, and a second plate-shaped member joined to the first plate-shaped member by a brazing material and having lattice-shaped slits communicating with the back hole. Each of the two plate-shaped members is configured to have a uniform thickness.

When manufacturing a ceramic honeycomb structure, the forming raw material supplied from the extrusion molding machine is introduced into the back hole of the first plate-shaped member, and extrusion molding is performed by pushing this forming raw material through the lattice-shaped slits. At this time, in order to prevent the slits from being worn down by the forming raw material, which is a hard ceramic material, the second plate-shaped member is made of a cemented carbide.

JP 2009-184237 A

The molding raw material supplied from the extrusion molding machine forms a flow velocity distribution in which the speed in the center is faster than that in the peripheral portion just before it is introduced into the back hole of the first plate-like member. This causes wear to progress more easily in the center of the molding die than in the peripheral portion. As wear progresses in the center, resistance decreases, making it easier for the molding raw material to flow than in the peripheral portion. As a result, the flow velocity in the center of the molded body extruded from the slit also becomes faster than that in the peripheral portion, which can cause problems such as unstable quality of the honeycomb structure. This problem becomes more pronounced as the hardness of the molding raw material increases.

The present invention was made in consideration of these problems, and aims to provide an extrusion molding technology that is effective in stabilizing the quality of ceramic honeycomb structures.

One aspect of the present invention is
A molding die (1, 101, 201) used for extrusion molding of a ceramic honeycomb structure (H),
A first plate-shaped portion (10) made of a first metal material;
a second plate-shaped portion (20) made of a second metal material having a hardness greater than that of the first metal material and joined to the first plate-shaped portion;
Equipped with
The first plate-shaped portion is provided with a first joint surface (11) which is a joint surface with the second plate-shaped portion, and a raw material supply surface (12) opposite to the first joint surface, and a plurality of raw material supply holes (13) extend from the raw material supply surface in a raw material extrusion direction (D);
The second plate-shaped portion is provided with a second joint surface (21) which is a joint surface with the first plate-shaped portion, and an extrusion surface (22) opposite to the second joint surface, and a lattice-shaped slit (23) communicating with the plurality of raw material supply holes is opened in the extrusion surface,
a molding die (1, 101, 201), wherein the second plate-shaped portion has a high flow rate portion (24) having the slit communicating with a first supply hole (13A) having a relatively high introduction rate of the molding raw material (Ma) among the plurality of raw material supply holes, and a low flow rate portion (25) having the slit communicating with a second supply hole (13B) having a relatively low introduction flow rate of the molding raw material (Ma) among the plurality of raw material supply holes, and is configured such that the high flow rate portion exceeds the low flow rate portion in terms of thickness in the raw material extrusion direction;
is located.

The molding die of the above-mentioned embodiment is used for extrusion molding of a ceramic honeycomb structure, and has a first plate-shaped part on the side where the molding raw material is supplied, and a second plate-shaped part on the side where the honeycomb structure is extruded. This molding die is integrated by bonding the first joint surface of the first plate-shaped part and the second joint surface of the second plate-shaped part to each other. The molding raw material that will become the honeycomb structure is introduced into the molding die through a plurality of raw material supply holes extending from the raw material supply surface of the first plate-shaped part in the raw material extrusion direction. This molding raw material passes through lattice-shaped slits that communicate with the plurality of raw material supply holes, and is extruded as a honeycomb structure from the extrusion surface of the second plate-shaped part.

The high flow rate portion of the second plate-shaped portion is a portion having a slit that communicates with a first supply hole, which has a relatively high introduction rate of the molding raw material among the multiple raw material supply holes. In contrast, the low flow rate portion of the second plate-shaped portion is a portion having a slit that communicates with a second supply hole, which has a relatively low introduction rate of the molding raw material among the multiple raw material supply holes. The slit wear portion, in which the width of the slit has expanded due to wear caused by the introduced molding raw material, extends until it reaches the second plate-shaped portion made of a second metal material that is harder than the first metal material.

Here, the second plate-shaped portion is configured so that the thickness of the high flow rate portion in the raw material extrusion direction is thicker than the thickness of the low flow rate portion in the raw material extrusion direction. According to this configuration, as a result of wear of each slit, the slit connected to the second supply hole has a slit wear length in the raw material extrusion direction longer than the slit connected to the first supply hole, and the slit connect to the first supply hole has a slit wear length in the raw material extrusion direction shorter than the slit connected to the second supply hole. Therefore, it is possible to increase the flow resistance of the forming raw material in the first supply hole to make it difficult for the forming raw material to flow to the first supply hole, while it is possible to decrease the flow resistance of the forming raw material in the second supply hole to make it easier for the forming raw material to flow to the second supply hole. As a result, it is possible to uniformly control the speed distribution of the honeycomb structure extruded from the slit.

As described above, the above-mentioned embodiment provides an extrusion molding technique that is effective in stabilizing the quality of ceramic honeycomb structures.

The reference characters in parentheses in the claims and the means for solving the problems indicate the corresponding relationship with the specific means described in the embodiments described below, and do not limit the technical scope of the present invention.

FIG. 2 is a plan view of the molding die of the first embodiment. FIG. 2 is a partial cross-sectional view of the molding die of FIG. 1 . FIG. 2 is a perspective view of a honeycomb structure formed by the forming die of FIG. 1 . FIG. 2 is a diagram showing the flow rate distribution of the molding raw material before being introduced into the raw material supply hole of the molding die of FIG. 1 . FIG. 5 is a diagram showing a flow velocity distribution of a molded body extruded from the molding die in FIG. 4 . 2 is a flowchart of a molding process of a honeycomb structure using the molding die of FIG. 1 . FIG. 7 is a perspective view of a first metal plate material in a first step of the joining process in FIG. 6 . FIG. 7 is a diagram showing a schematic view of a first step of the bonding process in FIG. 6 . 7 is a perspective view showing how a raw material supply hole is machined in the first plate-shaped portion of the workpiece in the second step of the hole machining process in FIG. 6 . FIG. 10 is a cross-sectional view of the workpiece taken along line X-X in FIG. 7 is a perspective view showing how slits are formed in the second plate-shaped portion of the workpiece in the third step of the slit processing process in FIG. 6 . 12 is a cross-sectional view of the workpiece taken along line XII-XII in FIG. 11 . FIG. 11 is a partial cross-sectional view of a molding die according to a fourth embodiment. FIG. 13 is a partial cross-sectional view of a molding die according to a fifth embodiment.

Below, an embodiment of the molding die and an embodiment of the manufacturing method of the molding die will be described with reference to the drawings. This molding die is suitable for use as a honeycomb structure molding die for manufacturing ceramic honeycomb structures used, for example, in exhaust gas purification catalysts for automobiles, by extrusion molding of ceramic raw materials.

In the drawings of this specification, unless otherwise specified, the first direction, which is the horizontal direction of the molding die, is indicated by arrow X, the second direction, which is the vertical direction of the molding die, is indicated by arrow Y, and the third direction, which is the thickness direction of the molding die (a direction perpendicular to both the first and second directions), is indicated by arrow Z.

(Embodiment 1)
As shown in Fig. 1, the molding die 1 of the first embodiment is configured so that the outer shape in a plan view in the third direction Z is generally rectangular. As shown in Fig. 2, the molding die 1 includes a first plate-shaped portion 10 and a second plate-shaped portion 20 (see also Fig. 1) joined to the first plate-shaped portion 10. At this time, the third direction Z, which is the thickness direction of the molding die 1, is also the thickness direction of each of the first plate-shaped portion 10 and the second plate-shaped portion 20.

As shown in FIG. 2, the first plate-shaped portion 10 has a first joint surface 11 which is a joint surface with the second plate-shaped portion, and a raw material supply surface 12 which is an exposed surface opposite to the first joint surface 11. A plurality of raw material supply holes 13 extend from the raw material supply surface 12 in the raw material extrusion direction D. The raw material extrusion direction D generally coincides with the third direction Z. The multiple raw material supply holes 13 have the same shape, are parallel to each other, and are arranged at equal intervals.

The second plate-shaped portion 20 has a second joining surface 21, which is a joining surface with the first plate-shaped portion 10, and an extrusion surface 22, which is an exposed surface on the opposite side to the second joining surface 21. The extrusion surface 22 is a surface that is generally parallel to the raw material supply surface 12 of the first plate-shaped portion 10. The extrusion surface 22 has lattice-shaped slits 23 (see Figures 1 and 2) that communicate with the multiple raw material supply holes 13. The slit width of the slits 23 is configured to be smaller than the hole diameter of the raw material supply holes 13. The slits 23 are connected to the tapered portions 13a of the raw material supply holes 13, where the hole diameter is tapered.

In this embodiment, the multiple raw material supply holes 13 do not reach the second plate-shaped portion 20, while the slits 23 reach the first plate-shaped portion 10. The boundary between the raw material supply holes 13 and the slits 23 does not coincide with the boundary between the first plate-shaped portion 10 and the second plate-shaped portion 20. Therefore, the first plate-shaped portion 10 has both an area where the raw material supply holes 13 are formed and an area where a portion of the slits 23 is formed. In contrast, the second plate-shaped portion 20 does not have an area where the raw material supply holes 13 are formed.

If necessary, this molding die 1 can be designed so that the boundary between the raw material supply hole 13 and the slit 23 coincides with the boundary between the first plate-shaped portion 10 and the second plate-shaped portion 20.

The second plate-shaped portion 20 is made of a second metal material having a hardness greater than that of the first metal material of the first plate-shaped portion 10. As an example, in this embodiment, the first metal material is carbon steel or stainless steel, and the second metal material is a super-hard metal material containing tungsten carbide.

For example, Vickers hardness can be used as an index of hardness of metal materials. Vickers hardness is a known index of indentation hardness, and is generally calculated by pressing a rigid body into a test object and using the area of the indentation formed in the test object. Based on this Vickers hardness, it is determined whether the test object is hard or soft. In addition to Vickers hardness, other indices such as Rockwell hardness can be used as an index of hardness.

The first metal material, carbon steel or stainless steel, is a material that is easy to process and has excellent processing performance. By using such a first metal material, it is possible to realize a molding die 1 that has high processing accuracy and reduces processing costs.

The second metal material, a super-hard metal material containing tungsten carbide, is a material that is hard and has excellent wear resistance. By using such a second metal material, a molding die 1 can be realized in which metal wear of the slit 23 is suppressed. Note that this super-hard metal material may contain cobalt or nickel as a binder metal. Also, instead of tungsten carbide, materials such as stellite and colmonoy, which have excellent wear resistance and corrosion resistance, may be used.

As shown in FIG. 3, the honeycomb structure H is, for example, cylindrical, and is configured by dividing the inside of the cylindrical outer shell into a large number of cells C by honeycomb-shaped cell walls H1. The shape and size of the cells C can be selected arbitrarily. In this embodiment, as an example, the shape of the cells C is a square, and the size is set to the same size in the entire region. If necessary, the shape of the cells C can be a polygon with a triangle or more sides or a combination of multiple shapes, and the size of the cells C can be changed for each of the multiple regions divided in the circumferential direction, for example, to have different cell densities on the inner and outer sides.

The slits 23 of the second plate-shaped portion 20 are in the shape of a rectangular lattice corresponding to the square cells C of the honeycomb structure H. The shape of the slits 23 is constant in the raw material extrusion direction D and determines the final shape of the honeycomb structure H. For example, the lattice spacing and slit width of the slits 31 are set according to the pitch of the cells C and the thickness of the cell walls H1. The height of the slits 31 is not particularly limited and can be set to, for example, approximately the same as the lattice spacing of the slits 23.

As shown in FIG. 4, when extruding a honeycomb structure H using the molding die 1, the clay-like molding raw material Ma is extruded from the extrusion molding machine A toward the raw material supply surface 12 of the first plate-shaped portion 10. As a result, the molding raw material Ma is introduced into the multiple raw material supply holes 13 and flows continuously inside the molding die 1 in one direction, which is the raw material extrusion direction D. Then, the molding raw material Ma that passes through the slits 23 is extruded from the extrusion surface 22 as the honeycomb structure H.

The forming raw material Ma is not particularly limited, but as an example, a ceramic raw material that produces cordierite, SiC, etc. after firing can be used.

Here, when the raw material Ma is extruded from the extrusion molding machine A, that is, immediately before being introduced into the multiple raw material supply holes 13, it is assumed that the flow velocity distribution is such that the flow velocity Va is faster in the center than in the outer periphery due to the influence of the wall surface of the molding machine A and the influence of the screw used for extrusion. Then, due to the influence of this flow velocity distribution, the first supply hole 13A, which has a relatively high introduction speed of the raw material Ma among the multiple raw material supply holes 13, and the second supply hole 13B, which has a relatively low introduction speed of the raw material Ma among the multiple raw material supply holes 13 (lower introduction speed than the first supply hole 13A) are formed. For this reason, the second plate-shaped portion 20 has a high flow velocity portion 24 located downstream of the first supply hole 13A in the raw material extrusion direction D, and a low flow velocity portion 25 located downstream of the second supply hole 13B in the raw material extrusion direction D (see Figures 2 and 4). The high flow rate section 24 has a slit 23 that communicates with the first supply hole 13A, and the low flow rate section 25 has a slit 23 that communicates with the second supply hole 13B.

When the forming raw material Ma forms a flow velocity distribution as described above, if the thickness of the second plate-shaped portion 20 in the third direction Z is made uniform, the first supply hole 13A in the center will wear more easily than the second supply hole 13B in the outer periphery, and the flow resistance of the forming raw material Ma will be lower than that of the second supply hole 13B. As a result, the forming raw material Ma will flow more easily toward the first supply hole 13A, and the forming body Mb extruded from the slit 23 will also form a flow velocity distribution in which the flow velocity is faster in the center than in the outer periphery. In this case, if the forming body Mb is extruded so that its center is raised in the raw material extrusion direction D relative to the outer periphery, it will be difficult to stabilize the quality of the honeycomb structure H.

Therefore, in this embodiment, the second plate-shaped portion 20 is configured so that the high flow rate portion 24 exceeds the low flow rate portion 25 in terms of thickness in the raw material extrusion direction D. That is, in accordance with the flow rate distribution of the molding raw material Ma before being introduced into the multiple raw material supply holes 13, the central portion when the second plate-shaped portion 20 is viewed from the raw material extrusion direction D is the high flow rate portion 24, and the outer periphery surrounding the outside of the central portion in an annular shape is the low flow rate portion 25, and the thickness in the raw material extrusion direction D becomes thicker from the outer periphery toward the central portion, that is, the thickness in the raw material extrusion direction D becomes thinner from the central portion toward the outer periphery.

The effects of this configuration are explained with reference to Figure 5.

As shown in FIG. 5, the region of the slit 23 formed in the first plate-shaped portion 10 of each raw material supply hole 13 is worn by the introduced molding raw material Ma. At this time, since the second metal material of the second plate-shaped portion 20 is harder than the first metal material of the first plate-shaped portion 10, the narrowed portion 13a of each raw material supply hole 13 (the downstream portion of each raw material supply hole 13 in the raw material extrusion direction D) is expanded downstream in the raw material extrusion direction D compared to the initial state until it reaches the second joint surface 21, which is the boundary with the second plate-shaped portion 20. As a result, each raw material supply hole 13 changes from the initial state shown by the two-dot chain line in FIG. 5 to the worn state shown by the solid line.

In this embodiment, the second plate-shaped portion 20 is configured so that the low flow velocity portion 25 is thinner in the third direction Z than the high flow velocity portion 24. This makes it possible to suppress wear in the center of the first plate-shaped portion 10 compared to wear in the outer periphery, and to prevent uneven wear in the center.

The second supply hole 13B has a hole length in the raw material extrusion direction D longer than the first supply hole 13A, and the slit 23 communicating with this second supply hole 13B has a slit depth in the raw material extrusion direction D shorter than the slit 23 communicating with the first supply hole 13A. On the other hand, the first supply hole 13A has a hole length in the raw material extrusion direction D shorter than the second supply hole 13B, and the slit 23 communicating with this first supply hole 13A has a slit depth in the raw material extrusion direction D longer than the slit 23 communicating with the second supply hole 13B.

At this time, since the flow resistance of the forming raw material Ma is greater in the first supply hole 13A than in the second supply hole 13B, the forming raw material Ma flows less easily in the first supply hole 13A than in the second supply hole 13B. On the other hand, since the flow resistance of the forming raw material Ma is smaller in the second supply hole 13B than in the first supply hole 13A, the forming raw material Ma flows more easily in the second supply hole 13B than in the first supply hole 13A. This makes it possible to form a velocity distribution in which the flow velocity Vb of the forming body Mb is roughly constant in the center and the outer periphery. By uniformly controlling the velocity distribution of the forming body Mb (honeycomb structure H) extruded from the slit 23, it becomes possible to stabilize the quality of the honeycomb structure H.

Next, a method for manufacturing the molding die 1 having the above configuration will be described with reference to Figures 6 to 12.

As shown in FIG. 6, the manufacturing method of the first embodiment is a method in which the first step S101 to the third step S103 are executed in sequence. Note that, if necessary, at least one step may be divided into multiple steps, or another step or multiple steps may be added.

The first step S101 is a joining process for joining the second plate-shaped portion 20 to the first plate-shaped portion 10. The second step S102 is a hole processing process for processing a plurality of raw material supply holes 13 in the raw material supply surface 12 of the first plate-shaped portion 10 joined in the first step S101. The third step S103 is a slit processing process for processing slits 23 in the extrusion surface 22 of the second plate-shaped portion 20 joined in the first step S101.

(Joining process)
7, the joining process in the first step S101 utilizes a technique called "metal additive manufacturing." Powder of a second metal material is melted and solidified by the metal additive manufacturing method on the first joining surface 11 of the first plate-shaped portion 10, which is a plate-shaped member, to form the second plate-shaped portion 20.

As shown in FIG. 8, in more detail, in this joining process, the first process (P1) and the second process (P2) are alternately and repeatedly performed.

The first process (P1) is a process in which the first plate-shaped portion 10 is set on the upper surface of the base 300 with the first joining surface 11 facing up, and powder 301 of the second metal material is filled so as to cover the entire first plate-shaped portion 10. The second process (P2) is a process in which a laser irradiation device 302 is used to scan laser light at desired locations of the powder 301, causing the powder 301 to melt and solidify.

According to the second process (P2), a metal layer made of a second metal material is formed on the first joining surface 11 of the first plate-shaped portion 10. At this time, the thickness of the metal layer formed by one laser irradiation of the laser irradiation device 302 is, for example, about 0.05 mm.
After the powder 301 has melted and solidified, the first process (P1) is carried out again.

Then, the first process (P1) and the second process (P2) are alternately repeated until the metal layer reaches the desired thickness. This forms a workpiece W in which the second plate-shaped portion 20 is joined to the first plate-shaped portion 10. This workpiece W is the honeycomb structure H before the raw material supply holes 13 and slits 23 are formed.

In the joining process of the first step S101, instead of the method of forming a layer of the second plate-shaped portion 20 on the first plate-shaped portion 10, which is a plate-shaped member, by metal additive manufacturing, another method of forming a layer of the first plate-shaped portion 10 on the second plate-shaped portion 20, which is a plate-shaped member, by metal additive manufacturing, or another method of joining the first plate-shaped portion 10 and the second plate-shaped portion 20, both of which are plate-shaped members, to each other by welding or the like may be used.

(Hole drilling process)
9, in the hole processing step of the second step S102, for example, it is preferable to use a drill 303, which is a cutting tool for hole processing. The drill 303 is pressed against the raw material supply surface 12 of the first plate-shaped portion 10 in a rotating state and pressed in. This processing is performed as many times as the number of required raw material supply holes 13. In this way, the planned number of raw material supply holes 13 can be formed in the first plate-shaped portion 10.

In this embodiment, as shown in FIG. 10, the drilling of each raw material supply hole 13 is terminated just before the tip of the drill 303 reaches the second joining surface 21 of the second plate-shaped portion 20.

In addition, in the hole processing step of the second step S102, instead of using a drill 303 to form each raw material supply hole 13, a different method using a known electric discharge machining or electrochemical machining may be used to form each raw material supply hole 13.

(Slitting process)
As shown in Fig. 11, the slit machining process in the third step S103 uses, as an example, a method called "die-sinking electric discharge machining". In an insulating machining fluid, an electrode 304 is placed facing the extrusion surface 22 of the second plate-shaped portion 20 of the workpiece W, and electric discharge machining is performed in which minute electric discharges are repeatedly generated from the discharge fins 306 of the electrode 304 to the second plate-shaped portion 20. The discharge fins 306 have a shape corresponding to the shape of the slits 23. By this electric discharge machining, the slits 23 as shown in Fig. 12 are formed, and the slits 23 are connected to the multiple raw material supply holes 13.

In addition, in the slit machining process of the third step S103, cutting machining may be used to form the slits 23 with a cutting blade instead of die-sinking electric discharge machining.

Although not specifically shown, the electrode 304 can be manufactured by performing wire electric discharge machining on the electrode material. First, a through hole is machined in the electrode material with a drill 303 to pass the electric discharge wire through. The electric discharge wire is then passed through the through hole, and the discharge heat is used to expand the through hole into a machined hole 305 with a rectangular cross section, forming a discharge fin 306 (see FIG. 11). Instead of this wire electric discharge machining, the electrode 304 may be manufactured using known electric discharge machining or electrochemical machining.

Next, the effects of the above-mentioned embodiment 1 will be explained.

The molding die 1 of the above-mentioned embodiment is used for extrusion molding of a ceramic honeycomb structure H, and has a first plate-shaped portion 10 on the side where the molding raw material Ma is supplied, and a second plate-shaped portion 20 on the side where the honeycomb structure H is extruded. This molding die 1 is integrated by bonding the first joint surface 11 of the first plate-shaped portion 10 and the second joint surface 21 of the second plate-shaped portion 20 to each other. The molding raw material Ma that becomes the honeycomb structure H is introduced into the molding die 1 through a plurality of raw material supply holes 13 extending from the raw material supply surface 12 of the first plate-shaped portion 10 in the raw material extrusion direction D. This molding raw material Ma passes through lattice-shaped slits 23 that communicate with the plurality of raw material supply holes 13, and is extruded as the honeycomb structure H from the extrusion surface 22 of the second plate-shaped portion 20.

The high flow rate portion 24 of the second plate-shaped portion 20 is a portion having a slit 23 that communicates with the first supply hole 13A, and the low flow rate portion 25 of the second plate-shaped portion 20 is a portion having a slit 23 that communicates with the second supply hole 13B. The slit wear portion, in which the width of the slit has expanded due to wear caused by the introduced molding raw material Ma, extends until it reaches the second plate-shaped portion 20 made of a second metal material that is harder than the first metal material.

Here, the second plate-shaped portion 20 is configured so that the thickness of the high flow rate portion 24 in the raw material extrusion direction D is thicker than the thickness of the low flow rate portion 25 in the raw material extrusion direction D. According to this configuration, as a result of wear of each slit 23, the slit 23 connected to the second supply hole 13B has a slit wear length in the raw material extrusion direction D longer than the slit 23 connected to the first supply hole 13A, and the slit 23 connected to the first supply hole 13A has a slit wear length in the raw material extrusion direction D shorter than the slit 23 connected to the second supply hole 13B. Therefore, the flow resistance of the forming raw material Ma in the first supply hole 13A can be increased to make it difficult for the forming raw material Ma to flow to the first supply hole 13A, while the flow resistance of the forming raw material Ma in the second supply hole 13B can be decreased to make it easier for the forming raw material Ma to flow to the second supply hole 13B. As a result, it is possible to uniformly control the speed distribution of the honeycomb structure H extruded from the slit 23.

Therefore, according to the above-mentioned embodiment 1, it is possible to provide an extrusion molding technique that is effective in stabilizing the quality of the ceramic honeycomb structure H.

Below, other embodiments related to the above-mentioned first embodiment will be described with reference to the drawings. In the other embodiments, elements that are the same as those in the above-mentioned first embodiment are given the same reference numerals, and descriptions of the same elements will be omitted.

(Embodiment 2)
The second embodiment differs from the first embodiment in the second metal material of the second plate-shaped portion 20. In the second embodiment, the second metal material is a high-entropy alloy material mainly composed of chromium, iron, nickel, and cobalt. The first metal material is carbon steel or stainless steel, as in the first embodiment.

The rest of the configuration is the same as in embodiment 1.

The first metal material and the second metal material used in the second embodiment are both materials with excellent processing performance. Therefore, compared to the first embodiment, it is possible to realize a molding die 1 with high processing accuracy and reduced processing costs.

Otherwise, it has the same effects as embodiment 1.

(Embodiment 3)
The third embodiment differs from the second embodiment in the second metal material of the second plate-shaped portion 20. In the third embodiment, the second metal material is an alloy material mainly composed of cobalt or nickel. The first metal material is carbon steel or stainless steel, as in the first embodiment.

The rest of the configuration is the same as in embodiment 2.

The second metal material used in the third embodiment is a material with even better processing performance than that in the second embodiment. Therefore, it is possible to realize a molding die 1 with higher processing accuracy and reduced processing costs compared to the second embodiment.

Otherwise, it has the same effects as embodiment 2.

(Embodiment 4)
13 , the molding die 101 of the fourth embodiment differs from the molding die 1 of the first embodiment in that an abrasion-resistant coating 26 is provided on the entire inner wall surface of the slit 23. The abrasion-resistant coating 26 is formed on the inner wall surface of the slit 23.

The rest of the configuration is the same as in embodiment 1.

According to the fourth embodiment, the wear resistance of the slit 23 can be improved compared to a structure without the wear-resistant coating 26. The type of wear-resistant coating 26 is not particularly limited, but as an example, a TiCN film (titanium carbonitride coating) made of a Ti-C-N composition can be used. This TiCN film is a ceramic coating film that has the characteristics of high hardness and low friction, and also has strong adhesion, so it is suitable for use as a coating for the slit 23.

Otherwise, it has the same effects as embodiment 1.

(Embodiment 5)
14 , the molding die 201 of the fifth embodiment differs from the molding die 101 of the fourth embodiment in that, in addition to the abrasion-resistant coating 26 being provided on the entire inner wall surface of the slit 23, the abrasion-resistant coating 15 is provided on the entire inner wall surface of each raw material supply hole 13. The abrasion-resistant coating 15 is formed on the inner wall surface of each raw material supply hole 13.

The rest of the configuration is the same as in embodiment 4.

According to the fifth embodiment, the wear resistance of each raw material supply hole 13 can be improved compared to a structure without the wear-resistant coating 15. The type of the wear-resistant coating 15 is not particularly limited, but in order to keep the cost of the film-forming material and the cost of the film-forming process low, it is preferable to use a TiCN film similar to the wear-resistant coating 26.

Otherwise, it has the same effects as embodiment 4.

The present invention is not limited to the exemplary embodiment described above, and various applications and modifications are possible without departing from the purpose of the present invention. For example, the following forms can be implemented by applying the above-described embodiment.

In the above embodiment, the central portion of the second plate-shaped portion 20 is the high flow rate portion 24, and the outer periphery of the second plate-shaped portion 20 is the low flow rate portion 25. However, the arrangement of the high flow rate portion 24 and the low flow rate portion 25 in the second plate-shaped portion 20 can be changed as appropriate depending on the flow rate distribution of the forming raw material Ma before it is introduced into the multiple raw material supply holes 13.

In the above embodiment, the honeycomb structure H is cylindrical, but the outer shape of the honeycomb structure H can also be a shape other than a circle, such as an ellipse or a racetrack shape.

The honeycomb structure H manufactured using the above molding dies 1, 101, 201 can be suitably used as a carrier for supporting a catalyst, for example, in an exhaust gas purification catalyst for automobiles. Furthermore, the molding dies 1, 101, 201 and their manufacturing method are not limited to the above-mentioned embodiments, and can be applied to various embodiments within the scope of the gist of the invention.

1,101,201...molding die, 10...first plate-shaped part, 11...first joining surface, 12...raw material supply surface, 13...raw material supply hole, 13A...first supply hole, 13B...second supply hole, 20...second plate-shaped part, 21...second joining surface, 22...extrusion surface, 23...slit, 24...high flow rate part, 25...low flow rate part, 26...wear-resistant coating, D...raw material extrusion direction, H...honeycomb structure, Ma...molding raw material, S101...first step (joining process), S102...second step (hole processing process), S103...third step (slit processing process)

Claims (7)

A molding die (1, 101, 201) used for extrusion molding of a ceramic honeycomb structure (H),
A first plate-shaped portion (10) made of a first metal material;
a second plate-shaped portion (20) made of a second metal material having a hardness greater than that of the first metal material and joined to the first plate-shaped portion;
Equipped with
The first plate-shaped portion is provided with a first joint surface (11) which is a joint surface with the second plate-shaped portion, and a raw material supply surface (12) opposite to the first joint surface, and a plurality of raw material supply holes (13) extend from the raw material supply surface in a raw material extrusion direction (D);
The second plate-shaped portion is provided with a second joint surface (21) which is a joint surface with the first plate-shaped portion, and an extrusion surface (22) opposite to the second joint surface, and a lattice-shaped slit (23) communicating with the plurality of raw material supply holes is opened in the extrusion surface,
The second plate-shaped portion has a high flow rate portion (24) having the slit communicating with a first supply hole (13A) having a relatively high introduction speed of the molding raw material (Ma) among the plurality of raw material supply holes, and a low flow rate portion (25) having the slit communicating with a second supply hole (13B) having a relatively low introduction flow speed of the molding raw material (Ma) among the plurality of raw material supply holes, and is configured so that the high flow rate portion exceeds the low flow rate portion in terms of thickness in the raw material extrusion direction. The molding die according to claim 1, wherein the second plate-shaped portion has a central portion as viewed from the raw material extrusion direction as the high flow rate portion and an outer peripheral portion surrounding the central portion as the low flow rate portion, according to the flow rate distribution of the molding raw material (Ma) before being introduced into the plurality of raw material supply holes. The molding die according to claim 1 or 2, wherein the first metal material is carbon steel or stainless steel, and the second metal material is a hard metal material containing tungsten carbide. The molding die according to claim 1 or 2, wherein the first metal material is carbon steel or stainless steel, and the second metal material is a high-entropy alloy material mainly composed of chromium, iron, nickel, and cobalt. The molding die according to claim 1 or 2, wherein the first metal material is carbon steel or stainless steel, and the second metal material is an alloy material mainly composed of cobalt or nickel. The molding die according to any one of claims 1 to 4, wherein the inner wall surface of the slit is provided with an abrasion-resistant coating (26) made of a Ti-C-N composition. A method for producing the molding die according to any one of claims 1 to 6,
A joining step (S101) of joining the second plate-shaped portion to the first plate-shaped portion;
a hole processing step (S102) of processing the plurality of raw material supply holes on the raw material supply surface of the first plate-shaped portion joined in the joining step;
A slit processing step (S103) of processing the slit on the extrusion surface of the second plate-shaped portion joined in the joining step;
having
A method for manufacturing a molding die, wherein the joining process is a process of melting and solidifying powder of the second metal material on the first joining surface of the first plate-shaped portion by a metal additive manufacturing method to form the second plate-shaped portion.

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