Patent Publication Number: US-2016236373-A1

Title: Extrusion molding device and method for manufacturing green honeycomb molded body

Description:
TECHNICAL FIELD 
     The present invention relates to an extrusion molding device and a method for manufacturing a green honeycomb molded body. 
     BACKGROUND ART 
     Ceramic honeycomb fired bodies have been widely known as diesel particulate filters or the like. The ceramic honeycomb fired body has a structure in which one end sides of some through holes of a honeycomb structure, which includes a large number of through holes, are sealed with a sealing material, and the other end sides of the remaining through holes are sealed with a sealing material. In Patent Literature 1, an extrusion molding device used for manufacturing a green honeycomb honeycomb molded body is disclosed. The device includes a first pipe having a screw, a filtration net, a taper tube, and a die, in this order. 
     CITATION LIST 
     Patent Literature 
     [Patent Literature 1] Japanese Unexamined Patent Publication No. 2000-301517 
     SUMMARY OF INVENTION 
     Technical Problem 
     Now, in an extrusion molding device such as Patent Literature 1, in order to extrude a green honeycomb molded body in a desired honeycomb geometry, there is a case where it is preferable to provide extension tube portions, the inner diameter of which is constant, at the front and rear of the taper tube. 
     Then, in the extrusion molding device of such a configuration, in the case of, for example, changing an exterior shape of a green honeycomb molded body to be molded, it is cumbersome to remove the die, the extension tube portion, the resistance tube, and the extension tube portion, from the extrusion molding device, and to fasten thereafter the other extension tube portion, the resistance tube, the extension tube portion, and the die, to the extrusion molding device. 
     The present invention is made in view of the above problem and has an objective to provide an extrusion molding device that is easy to perform changing operation and a method for manufacturing a green honeycomb molded body using the extrusion molding device. 
     Solution to Problem 
     An extruding device according to the present invention comprises a first pipe, a screw that is provided in the first pipe, a second pipe that is connected to the outlet of the first pipe, a flow adjustment plate that is provided between the first pipe and the second pipe, and a die that is connected to the outlet of the second pipe. The second pipe includes, in order from the side of the first pipe, a first portion having a constant inner diameter, a second portion having an inner diameter that decreases as the second portion extends from the first portion, and a third portion having a constant inner diameter. The second portion is undetachably integrated with the first portion, and the third portion is undetachably integrated with the second portion. 
     According to the present invention, since the first portion, the second portion, and the third portion are integrated, a detachable mechanism between the first portion and the second portion, and a detachable mechanism between the second portion and the third portion, are dispensed with, the reduction in weight and costs of the second pipe is achieved, and moreover the change of the first portion to the third portion can be quickly performed when the external shape of an extrusion-molded body (e.g., a diameter) is changed. 
     The inner surface of the second portion may include a slope inclining such that the inner diameter gradually decreases as the second portion extends from an upstream side to a downstream side, and an inclination angle of the inner surface of the second portion with respect to a central axis of the second portion may decrease stepwise as the second portion extends from the upstream side to the downstream side. In this case, composite material can be smoothly led toward the die. 
     The above extrusion molding device may further comprise a hydraulic clamp or magnet clamp that fastens the second pipe and the first pipe in a detachable manner. In this case, the change of the first portion to the third portion becomes further easier. 
     In the flow adjustment plate, an inclining through hole may be formed, the inclining through hole inclining with respect to the central axis of a channel that runs from the first pipe toward the second pipe. In this case, at least some of composite material on the upstream side of the flow adjustment plate passes through the inclining through hole of the flow adjustment plate and flows in a direction that inclines with respect to the central axis of the channel, in the downstream side of the flow adjustment plate. By a flow inclining with respect to the central axis of the channel being formed, composite material fluxes are merged with one another in a direction orthogonal to the central axis of the channel. For this reason, it is possible to reduce the variations of the composite material in fluidity in the direction orthogonal to the central axis of the channel. 
     The inclining through hole may be formed close to a center of the flow adjustment plate. In this case, since the flow inclining with respect to the central axis of the channel occurs in the central portion of the channel, composite material fluxes flowing through the central portion of the channel and composite material fluxes flowing through the periphery of the central portion are merged with one another. In an extrusion molding device, the fluidity of a composite material flux flowing through the central portion of the channel tends to be high as compared with the fluidity of a composite material flux flowing through the periphery of the central portion. Therefore, by mixing the composite material flux flowing through the central portion of the channel and the composite material flux flowing through the periphery of the central portion, it is possible to further reduce the variations of the composite material in fluidity in a direction orthogonal to the central axis of the channel. 
     The inclining through hole may be formed so as to approach the central axis as extending from one end side toward another end side. In this case, by composite material passing through the inclining through hole, a flow from the central portion of the channel toward the outside or a flow from the outside toward the central portion of the channel is formed. This causes composite material fluxes flowing through the central portion of the channel and composite material fluxes flowing through the periphery of central portion to be further better mixed with one another, and thus it is possible to further reduce the variations of the composite material in fluidity in a direction orthogonal to the central axis of the channel. 
     In the flow adjustment plate, a plurality of inclining through holes including the inclining through hole may be formed, some of the inclining through holes may be formed so as to approach the central axis as extending from an upstream side toward a downstream side, and others of the inclining through holes may be formed so as to approach the central axis as extending from the downstream side toward the upstream side. In this case, by the composite material fluxes flowing through the inclining through holes, both of the flows from the central portion of the channel toward the outside and flows from the outside toward the central portion of the channel are formed. This causes composite material fluxes flowing through the central portion of the channel and composite material fluxes flowing through the periphery of central portion to be further better mixed with one another, and thus it is possible to further reduce the variations of the composite material in fluidity in a direction orthogonal to the central axis of the channel. 
     The flow adjustment plate may include a main member that has an opening at a center, and a core member that is disposed in the opening, and the inclining through hole may be formed in the core member. In this case, for example, a plurality of core members can be prepared that differ in inner diameter, number, disposition, or inclining direction of inclining through holes, and can be changed as appropriate in conformity with the composition or the like of composite material. For this reason, it is possible to further reduce the variations of the composite material in fluidity in a direction orthogonal to the central axis of the channel. 
     The flow adjustment plate may include a plurality of stacked plates that are stacked along a central axis of a channel running from the first pipe toward the second pipe, in each of the stacked plates, a plurality of through holes may be formed, and the through holes in each of the stacked plates may be connected to a plurality of the through holes that are formed in the stacked plate adjacent to the each of the stacked plates. In this case, at least some of composite material on the upstream side of the flow adjustment plate passes through the through holes of the stacked plates. The through holes of each stacked plate are connected to a plurality of through holes of an adjacent stacked plate. At locations where a through hole on the upstream side is connected to a plurality of through holes on the downstream side, a composite material flux flowing out from the one through hole is separated and flows into the plurality of through holes. At locations where a through hole on the downstream side is connected to a plurality of through holes on the upstream side, composite material fluxes flowing out from the plurality of through holes flow into the one through hole and are merged with one another. In such a manner, the separation and merging of composite material occur in the course of passing through the plurality of stacked plates, which causes composite material fluxes to be mixed with one another in directions orthogonal to the central axis of the channel. For this reason, it is possible to reduce the variations of composite material in fluidity in the directions orthogonal to the central axis of the channel. 
     Each of the stacked plates may be disposed at a center of the flow adjustment plate. In this case, the separation and merging of the composite material occur in the central portion of the channel, and thus composite material fluxes flowing through the central portion of the channel and composite material fluxes flowing through the periphery of the central portion are merged with one another. In an extrusion molding device, the fluidity of a composite material flux flowing through the central portion of the channel tends to be high as compared with the fluidity of a composite material flux flowing through the periphery of the central portion. Therefore, by mixing the composite material flux flowing through the central portion of the channel and the composite material flux flowing through the periphery of the central portion, it is possible to further reduce the variations of the composite material in fluidity in a direction orthogonal to the central axis of the channel. 
     The plurality of stacked plates may include a stacked plate on an upstream side, a stacked plate on a downstream side, and a middle stacked plate that is disposed between the stacked plates on the upstream side and the downstream side, the through holes formed in the stacked plate on the downstream side may be connected to a plurality of the through holes that are formed closest to a center side and closest to an outer edge side of the stacked plate on the upstream side, via the through holes formed in the middle stacked plate. In this case, composite material fluxes flowing into the through hole that are formed closest to the center side of the stacked plate on the upstream side and composite material fluxes flowing into the through holes that are formed closest to the outer edge side of the stacked plate on the upstream side flow into one through hole of the stacked plate on the downstream side and are merged with one another. This causes composite material fluxes flowing through the central portion of the channel and composite material fluxes flowing through the periphery of the central portion to be further better mixed with one another. Therefore, it is possible to further reduce the variations of the composite material in fluidity in a direction orthogonal to the central axis of the channel. 
     The flow adjustment plate may include a main member that has an opening at a center, and a core member that is disposed in the opening, and the plurality of stacked plates may form the core member. In this case, for example, a plurality of core members can be prepared that differ in number of stacked plates, or in inner diameter, number, or disposition of the through holes of each stacked plate, and can be changed as appropriate in conformity with the composition or the like of composite material. For this reason, it is possible to further reduce the variations of the composite material in fluidity in a direction orthogonal to the central axis of the channel. 
     The plurality of stacked plates may include a stacked plate on an upstream side, a stacked plate on a downstream side, and a middle stacked plate that is disposed between the stacked plates on the upstream side and the downstream side, and in the middle stacked plate, the through holes may be formed that are smaller in inner diameter and larger in number as compared with the through holes of the stacked plates on the upstream side and the downstream side. In this case, the separation and merging of the composite material occur at more spots, which causes composite material fluxes to be further better mixed with one another in the directions orthogonal to the central axis of the channel. Therefore, it is possible to further reduce the variations of the composite material in fluidity in a direction orthogonal to the central axis of the channel. 
     The second pipe may further include a fourth portion that is positioned. on a downstream side of the third portion, and in the fourth portion, a rod that projects from an inner surface of the fourth portion toward a center side, and an actuator that adjusts a projecting length of the rod from the inner surface of the fourth portion, may be provided. In this case, by adjusting the projecting lengths of the rods  74 , it is possible to adjust the distribution of flow rate in the channel of the fourth portion so as to suppress the flexure of a molded body extruded from the die. 
     A method for manufacturing a green honeycomb molded body according to the present invention includes a step of extruding a ceramic material using an extrusion molding device, to obtain the green honeycomb molded body. The extrusion molding device is the above-described extrusion molding device. 
     Advantageous Effects of invention 
     According to the present invention, an extrusion molding device that is easy to perform changing operation and a method for manufacturing a green honeycomb molded body using the extrusion molding device are provided. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1( a )  is a perspective view illustrating an example of a green honeycomb molded body, and  FIG. 1( b )  is a partially enlarged view of the green honeycomb molded body. 
         FIG. 2  is a schematic cross sectional view illustrating a first embodiment of an extrusion molding device. 
         FIG. 3  is an enlarged cross sectional view illustrating a distal end portion of a first pipe and a second pipe in  FIG. 2 . 
         FIG. 4( a )  and  FIG. 4( b )  are perspective views illustrating operating states of a hydraulic clamp  60 . 
         FIG. 5  is a cross sectional view for illustrating a process of removing a second pipe  50  from a first pipe  10 . 
         FIG. 6  is a schematic cross sectional view illustrating a second embodiment of the extrusion molding device. 
         FIG. 7  is a schematic cross sectional view illustrating a third embodiment of the extrusion molding device. 
         FIG. 8  is a left side view of a main member in  FIG. 7 . 
         FIG. 9  is an enlarged view of a core member in  FIG. 7 . 
         FIG. 10  is a right, side view of the core member in  FIG. 7 . 
         FIG. 11  is a left side view of the core member in  FIG. 7 . 
         FIG. 12  is a cross sectional view taken along the line XII-XII in  FIG. 10 . 
         FIG. 13  is a cross sectional view taken along the line XIII-XIII in  FIG. 10 . 
         FIG. 14  is a cross sectional view taken along the line XIV-XIV in  FIG. 10 . 
         FIG. 15  is a cross sectional view taken along the line XV-XV in  FIG. 10 . 
         FIG. 16  is a schematic cross sectional view illustrating a fourth embodiment of the extrusion molding device. 
         FIG. 17  is a left side view of a stacked plate that is the closest to a downstream side in  FIG. 16 . 
         FIG. 18  is a left side view of a stacked plate that is the second closest to the downstream side in  FIG. 16 . 
         FIG. 19  is a left side view of a stacked plate that is the third closest to the downstream side in  FIG. 16 . 
         FIG. 20  is a left side view of a stacked plate that is the fourth closest to the downstream side in  FIG. 16 . 
         FIG. 21  is a left side view of a stacked plate that is the closest to an upstream side in  FIG. 16 . 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. First, a green honeycomb molded body will be described prior to the description of an extrusion molding device according to the present invention. 
     &lt;Green Honeycomb Molded Body&gt; 
     A green honeycomb molded body  70  illustrated in  FIG. 1  is acquired by subjecting a composite material to extrusion molding using the extrusion molding device to be described later. As illustrated in  FIG. 1( a ) , the green honeycomb molded body  70  is a cylinder. The green honeycomb molded body  70  includes a plurality of through holes  71   a  and  71   b  that are substantially parallel to each other and have different cross-sectional shapes. The plurality of through holes  71   a  and  71   b  are formed by a partition wall  72  that extends substantially parallel to the central axis of the green honeycomb molded body  70 . The through holes  71   a  each have a regular hexagon as the cross-sectional shape thereof. In contrast, the through holes  71   b  each have a wide hexagon as the cross-sectional shape thereof, and six through holes  71   b  surround one through hole  71   a.  The plurality of through holes are in an equilateral triangular disposition in the end face of the green honeycomb molded body  70  that is, central axes of the through holes  71   a  and  71   b  are disposed so as to be positioned at the vertices of an equilateral triangle. The size of the equilateral triangle can be determined such that each of the sides thereof is, for example, 3.5 to 6 mm. Note that a honeycomb structure can be produced by firing the green honeycomb molded body  70  at a predetermined temperature. The honeycomb structure is used as, for example, a filter for purifying gas exhausted from an internal combustion engine. 
     The length of the green honeycomb molded body  70  in a direction in which the through holes  71   a  and  71   b  extend is not specially limited, and can be, for example, 40 to 350 mm. In addition, the outer diameter of the green honeycomb molded body  70  is not specially limited, either, and can be, for example, 100 to 320 mm. 
     The composite material that makes up the green honeycomb molded body  70  is not specially limited and contains an inorganic compound source powder being a ceramic material, an organic binder such as a methyl cellulose, and an additive that is added as needed. From the viewpoint of high-temperature tolerance of a honeycomb fired body, preferred ceramic materials include an oxide such as an alumina, silica, mullite, cordierite, glass, and aluminum titanate, a silicon carbide, a silicon nitride, and the like. Note that the aluminum titanate can further contain a magnesium and/or a silicon. 
     For example, in the case of producing a green honeycomb molded body made of an aluminum titanate, the inorganic compound source powder contains an aluminum source powder such as an α alumina powder, and an titanium source powder such as an anatase-type or rutile-type titania powder, and can further contain, as needed, a magnesium source powder such as a magnesia powder and magnesia spinel powder, and/or a silicon source powder such as a silicon oxide powder and glass frit. 
     Organic binders include celluloses including a methyl cellulose, carboxymethyl cellulose, hydroxyalkyl methyl cellulose, carboxymethyl cellulose sodium, and the like; alcohols including a polyvinyl alcohol and the like; and a lignin sulfonate. 
     Additives include, for example, a pore forming agent, lubricant and plasticizer, dispersant, and solvent. 
     Pore forming agents include a carbon material such as a graphite; resins including a polyethylene, polypropylene, polymethyl methacrylate; a vegetable material such as a starch, nut shell, walnut shell, and corn; an ice; a dry ice, and the like. 
     Lubricants and plasticizers include alcohols including a glycerin; a higher fatty acid such as a caprylic acid, lauric acid, palmitic acid, arachidic acid, oleic acid, and stearic acid; a metal stearate such as an aluminum stearate, a polyoxyalkylene alkyl ether (POAAE), and the like. 
     Dispersants include, for example, an inorganic acid such as a nitric acid, hydrochloric acid, and sulfuric acid; an organic acid such as an oxalic acid, citric acid, acetic acid, malic acid, and lactic acid; alcohols including a methanol, ethanol, propanol, and the like; a surfactant such as an ammonium polycarboxylate, polyoxyalkylene alkyl ether, and the like. 
     As a solvent, for example, alcohols including a methanol, ethanol, butanol, propanol, and the like; glycols including a propylene glycol, polypropylene glycol, ethylene glycol, and the like; a water, and the like can be used. 
     &lt;Extrusion Molding Device According to First Embodiment&gt; 
     An example of an extrusion molding device according to a first embodiment will be described with reference to  FIG. 2  to  FIG. 5 . An extrusion molding device  1  illustrated in  FIG. 2  to  FIG. 5  is a device for producing a green honeycomb molded body  70  from a composite material in a powder form or a paste form. 
     The extrusion molding device  1  mainly includes a first pipe  10 , a second pipe  50  that is connected to the outlet of the first pipe  10 , a flow adjustment plate  20  that is provided between the first pipe  10  and the second pipe  50 , a die  90  that is connected on the downstream side of the second pipe  50 , and screws  2 A and  2 B that are provided in the first pipe  10 . 
     The first pipe  10  includes, in the order from the upstream side thereof, a barrel portion  12 , an extended portion  14 , a tapered portion  16 , and an adjustment plate fixing section  18 . 
     The screw  2 A is provided in the upper tier of the barrel portion  12 , and the screw  2 B is provided in the lower tier of the barrel portion  12 . The screws  2 A and  2 B knead composite material that is supplied from an inlet  12   a  of the barrel portion  12  and transfer the composite material to an outlet  12   e  of the barrel portion  12  through a channel  12   b.    
     As illustrated in  FIG. 3 , in the extended portion  14 , a channel  14   a  is formed that runs to the channel  12   b.  The inner diameter of the channel  14   a  is constant. The inner diameter of the extended portion  14  is, for example, the same as the inner diameter of the outlet  12   e  of the barrel portion  12 . In  FIG. 3 , the distal end portion of the screw  2 B is positioned in the extended portion  14  but is not limited to this position. 
     In the tapered portion  16 , a channel  16   a  is formed that runs to the channel  14   a.  The inner diameter of the channel  16   a  increases as the channel  16   a  extending from the barrel portion  12 . The inner diameter of the tapered portion  16  on the upstream side thereof is, for example, the same as the inner diameter of the channel  14   a.    
     In the adjustment plate fixing section  18 , a channel  18   b  is formed that runs to the channel  16   a.  On the downstream side of the adjustment plate fixing section  18 , in the circumferential portion of the channel  18   b,  a recessed portion  18   c  is formed that houses the circumferential portion of the flow adjustment plate  20 . On the outer circumference of the adjustment plate fixing section  18 , a flange portion  18   d  is formed. 
     The extended portion  14  and the tapered portion  16  are fastened to each other by bolts  13 , and the tapered portion  16  and the adjustment plate fixing section  18  are fastened to each other by welding. Although not illustrated, the barrel portion  12  and the extended portion  14  are fastened to each other by a bolt. 
     The second pipe  50  includes, in the order from the upstream side thereof (a first pipe  10  side), as first portion  32 , a second portion  34 , a third portion  36 , a fourth portion  38 , and a fifth portion  40 . 
     In the first portion  32 , a channel  32   b  is formed that runs to the channel  18   b.  The inner diameter of the channel  32   b  is, for example, the same as the inner diameter of the channel  18   b.  The length of the channel  32   b  can be, for example, 50 to 100 mm. The first portion  32  has a function of the connection with an upstream portion. On the outer circumference of the first portion  32 , a flange portion  32   c  is formed that overlaps with the flange portion  18   d  of the first pipe  10 . 
     A channel  34   a  of the second portion  34  has an inner diameter that decreases as the channel  34   a  extends from an upstream side to a downstream side. Specifically, the inner surface of the channel  34   a  includes a slope inclining such that the inner diameter gradually decreases as the channel  34   a  extends from the upstream side to the downstream side. The inclination angle of the inner surface of the channel  34   a  with respect to a central axis CL 1  of the channel  34   a  decreases stepwise as the channel  34   a  extends from the upstream side to the downstream side. For example, the inner surface of the channel  34   a  is divided into three regions  35   a,    35   b,  and  35   c  that are arranged from the upstream side to the downstream side. The inclination angle of the region  35   a  with respect to the central axis CL 1  is larger than the inclination angle of the region  35   b  with respect to the central axis CL 1 . The inclination angle of the region  35   b  with respect to the central axis CL 1  is larger than the inclination angle of the region  35   c  with respect to central axis CL 1 . The inclination angle of the region  35   c  with respect to the central axis CL 1  is substantially 0°. That is, the region  35   c  does not incline with respect to the central axis CL 1 . 
     The channel  34   a  runs to the channel  32   b,  and the inner diameter of the channel  34   a  on the upstream side thereof is, for example, the same as the inner diameter of the channel  32   b.  It is preferable that the inner diameter of the channel  34   a  on the downstream side thereof is smaller than the inner diameter of the channel  12   b  of the barrel portion  12 . It is preferable that the inner diameter of the channel  34   a  on the downstream side thereof is 60 to 100% of the inner diameter of the channel  12   b.  It is preferable that the length of the channel  34   a  is, for example, 100 to 200 mm, It is preferable that the inclination angle of the inner surface of the channel  34   a  with respect to the central axis CL 1  is 0 to 40°. The channel  34   a  has a function of flow amount adjustment of the composite material in a paste form. 
     In the third portion  36 , a channel  36   a  is formed that runs to the channel  34   a.  The inner diameter of the channel  36   a  is constant and, for example, the same as the inner diameter of the channel  34   a  on the downstream side thereof. The length of the channel  36   a  is, for example, 50 to 150 mm. The channel  36   a  has a function of flow amount adjustment of the composite material in a paste form. 
     The first portion  32  is welded to the second portion  34 , and the third portion  36  is welded to the second portion  34 . The welding method is not specially limited, and brazing, arc welding, or the like can be employed. Spots to be welded are not specially limited, either. Furthermore, the fastening method for the first portion  32  and the second portion  34 , and the fastening method for the second portion  34  and the third portion  36  are not limited to welding. The first portion  32  and the second portion  34 , and the second portion  34  and the third portion  36  may be undetachably integrated. Being undetachably integrated means that the integrated thing cannot be separated unless a fastened section is broken. The other examples of being detachably integrated include a manner in which the first portion  32  and the second portion  34 , and the second portion  34  and the third portion  36  are integrally formed from the same material. 
     On the outer circumference of the second portion  34 , a jacket structure  34 J is formed, and cooling medium such as cooling water can be supplied to the jacket structure  34 J. 
     Between the adjustment plate fixing section  18  of the first pipe  10  and the first portion  32  of the second pipe  50 , the flow adjustment plate  20  is disposed so as to partition off the channel  18   b  and the channel  32   b.  The flow adjustment plate  20  is sandwiched by the adjustment plate fixing section  18  and the first portion  32 , and the circumferential portion of the flow adjustment plate  20  is housed in the recessed portion  18   c.  The flow adjustment plate  20  is also referred to as a current plate, including a large number of through holes that penetrate therethrough in a flowing direction. By adjusting the positions and the size of the through holes, it is possible to control the flow behavior of the composite material in the second pipe  50 . In addition, foreign objects can be removed by the flow adjustment plate  20 . The diameter of the through holes is, for example, 1 to 10 mm. 
     The flow adjustment plate  20  has an outer diameter that is larger than the inner diameter of the channels  18   b  and  32   b  of the adjustment plate fixing section  18  and the first portion  32 , and a central portion of the flow adjustment plate  20  partitions off the channel  18   b  and the channel  32   b.  The flow adjustment plate  20  is sandwiched by the adjustment plate fixing section  18  and the first portion  32  so as to be attached to the first pipe  10  and the second pipe  50  in a detachable manner. 
     It is preferable that the flow adjustment plate  20  is a structure that hardly deforms even when pressure is applied thereto from the upstream side thereof. From such a viewpoint, it is preferable that the material of the flow adjustment plate  20  is, for example, a carbon steel or the like. Examples of a preferable material other than the carbon steel include a special steel that contains a nickel, chromium, tungsten, or the like. It is preferable from the viewpoint of securing a sufficient strength that the thickness of the flow adjustment plate  20  is 10 to 100 mm. 
     The first pipe  10  and the second pipe  50  are detachably coupled to each other by, for example, hydraulic clamps  60 . As illustrated in  FIG. 3  and  FIG. 4 , the hydraulic clamp  60  includes a cylinder actuator  62 , a rod  64 , and a locking section  66 . The cylinder actuator  62  is disposed so as to sandwich the flange portion  18   d  in cooperation with the flange portion  32   c,  and fixed to the flange portion  18   d.  The rod  64  projects from the cylinder actuator  62  so as to penetrate the flange portions  18   d  and  32   c.  The locking section  66  is formed at an end portion of the rod  64 , overhanging, from the outer circumference of the rod  64 . When viewed from the distal end side of the rod  64 , the locking section  66  has a shape that extends in one direction. In the extending direction of the locking section  66 , the overhang amount of the locking section  66  with respect to the outer circumference of the rod  64  is large as compared with the direction orthogonal to the extending direction of the locking section  66 . In the flange portions  18   d  and  32   c , through holes  18   a  and  32   a  are formed, respectively, the through holes  18   a  and  32   a  being in the cross-sectional shape corresponding to the shape of the locking section  66 . The cylinder actuator  62  can cause the rod  64  and the locking section  66  to reciprocate along the axis of the rod  64 , and to rotate about the axis of the rod  64 . 
     To couple the first pipe  10  and the second pipe  50  to each other, the locking section  66  is inserted into the through holes  18   a  and  32   a . Causing the locking section  66  to rotate using the cylinder actuator  62  brings about the state that, as illustrated in  FIG. 4( a ) , the locking section  66  is caught on the edge of the through hole  32   a  when viewed from a distal end portion. The cylinder actuator  62  pulls the locking section  66 . Then, the flange portions  18   d  and  32   c  are sandwiched by the cylinder actuator  62  and the locking section  66 , causing the second pipe  50  to be fastened to the first pipe  10 . 
     To separate the first pipe  10  from the second pipe  50 , the locking section  66  is moved away from the cylinder actuator  62 . Causing the locking section  66  to rotate using the cylinder actuator  62  brings about the state that, as illustrated in  FIG. 4( b ) , the locking section  66  is aligned with the through holes  18   a  and  32   a  when viewed from the distal end portion. This brings about the state that the locking section  66  is able to be inserted into the through holes  18   a  and  32   a  again, and as illustrated in  FIG. 5 , the first pipe  10  can be separated from the second pipe  50 . 
     Referring hack to  FIG. 3 , the fourth portion  38  includes a channel  38   b  that runs to the channel  36   a,  and a plurality of through holes  38   a  that communicates between the inside and the outside of the channel  38   b.  The through holes  38   a  are disposed so as to be positioned around the channel  38   b.  The fourth portion  38  is provided with a plurality of rods  74  and a plurality of cylinder actuators  76  that move the plurality of rods  74 , respectively, in the longitudinal directions thereof. The plurality of rods  74  are inserted through the plurality of through holes  38   a,  respectively, from the outside of the fourth portion  38 , and the distal end portions of the plurality of rods  74  project from the inner surface of the channel  38   b  toward the center of the channel  38   b.  The cylinder actuators  76  are fixed to the outside of the fourth portion  38 . By causing the rods  74  to move using the cylinder actuators  76 , the projecting lengths of the rods  74  from the inner surface of the channel  38   b  are adjusted. By adjusting the projecting lengths of the rods  74 , it is possible to adjust the distribution of flow rate in the channel  38   b  so as to suppress the flexure of a molded body extruded from the die  90 . The length of the channel of the fourth portion  38  is, for example, 100 to 200 mm. 
     In the fifth portion  40 , a channel  40   a  is formed that runs to the channel  38   b.  The inner diameter of the channel  40   a  is constant and, for example, the same as the inner diameter of the channel  38   b.  The length of the channel of the fifth portion  40  is, for example, 20 to 300 mm. On the downstream side of the channel  40   a,  the die  90  is provided. The die  90  is for shaping the composite material to obtain the molded body  70  in the shape illustrated in  FIG. 1 , including a latticed channel that corresponds to this shape (not illustrated), 
     The material of the second pipe  50  is not specially limited, and a metallic material such as an iron, and stainless can be used. It is preferable that the inner surface of the channel of the second pipe  50  includes a tungsten carbide layer so as to suppress abrasion. The tungsten carbide layer can be formed by a thermal spraying method. 
     &lt;Method for Manufacturing Green Honeycomb Molded Body&gt; 
     Next, a method for manufacturing the green honeycomb molded body  70  using the extrusion molding device  1  will be described. First, a composite material is fed from the inlet  12   a  into the channel  12   b.  By operating the screws  2 A and  2 B, the composite material is kneaded and transferred to the outlet  12   e  on the downstream side of the first pipe  10 . The kneaded material is caused to pass through the plurality of through holes of the flow adjustment plate  20  for the adjustment of flow rate distribution such as the unification of flow rate distribution, and thereafter fed to the die  90  through the second pipe  50 . The linear velocity of the composite material on the downstream side of the die  90  can be 10 to 150 cm/min. 
     The composite material is extruded from the die  90 , and the molded body  70 A is collected on a support table  95 . By cutting the molded body  70 A into pieces of a predetermined length, green honeycomb molded bodies  70  are obtained. As seen from the above, this method includes the process of extruding ceramic material using the extrusion molding device  1  to obtain the green honeycomb molded body  70 . By sealing one or the other end of the through holes of the green honeycomb molded body  70  and thereafter firing the green honeycomb molded body  70 , a honeycomb structure (a honeycomb filter) is obtained. 
     In order to obtain a green honeycomb molded body  70  in a different external shape, as illustrated in  FIG. 5 , the hydraulic clamp  60  is driven to release the fastening of the first pipe  10  and the second pipe  50 , and the second pipe  50  is separated from the first pipe  10 . Next, the other second pipe  50  may be coupled to the first pipe  10 , and thereafter the die  90  may be attached to the second pipe  50 . The other second pipes  50  include one, for example, of which the degree of tapering of the second portion  34  and/or the inner diameter of the third portion  36  to the fifth portion  40  is different from that of the original second pipe  50 . Note that when the second pipe  50  is detached from the first pipe  10 , the die  90 , the fifth portion  40 , and the fourth portion  38  may be detached from the third portion  36  in advance. In addition, similarly, when the other second pipe  50  is fastened to the first pipe  10 , the fourth portion  38 , the fifth portion  40 , and the die  90  does not have to be fastened to the other second pipe  50  in advance. 
     According to the present embodiment, since the first portion  32 , the second portion  34 , and the third portion  36  of the second pipe  50  are fastened to each other by welding, the attachment/detachment of the second pipe  50  to/from the first pipe  10  is easy, and furthermore weight reduction is possible. 
     &lt;Extrusion Molding Device According to Second Embodiment&gt; 
     Subsequently, an extrusion molding device according to a second embodiment will be described with reference to  FIG. 6 . What the extrusion molding device according to the present embodiment differs from the extrusion molding device according to the first embodiment is only the coupling structure of the first pipe  10  and the second pipe  50 . More in detail, this extrusion molding device  1 . includes a magnet clamp  80  in place of the hydraulic clamp  60 . The magnet clamp  80  is fixed to the flange portion  18   d  of the first pipe  10  so as to face the flange portion  32   c  of the second pipe  50 . 
     The magnet clamp  80  includes a back core  85 , a plurality of hard magnetic bodies  81 , a plurality of hard magnetic bodies  83 , and a plurality of soft magnetic bodies  82 . The hack core  85  is formed by a bottom portion  85   a  along the flange portion  18   d,  and wall portions  85   b  and  85   c  that project from the bottom portion  85   a  toward a flange portion  32   c  side, on an inner circumference side and an outer circumference side of the flange portion  18   d,  respectively. The back core  85  has soft magnetism. The plurality of hard magnetic bodies  81  and the soft magnetic bodies  82  are disposed between the wall portions  85   b  and  85   c  and alternately arranged along a surface opposite the bottom portion  85   a.  The hard magnetic bodies  81  form permanent magnets. The hard magnetic bodies  81  sandwiching the soft magnetic bodies  82  are disposed in such a manner that the same poles of the hard magnetic bodies  81  face each other across a soft magnetic body  82 . The hard magnetic bodies  83  are put between the bottom portion  85   a  of the back core  85  and the soft magnetic bodies  82 . In the hard magnetic bodies  83 , coils  84  are provided that inverse the poles of the hard magnetic bodies  83 . Note that examples of the hard magnetic body  81  include a neodymium magnet. Examples of the hard magnetic body  83  include an Alnico magnet. Examples of the soft magnetic body  82  include an iron. The flange portion  32   c  of the second pipe  50  is formed of a soft magnetic material, such as an iron, a martensitic stainless, and a ferritic stainless, which are attractable by a magnet. 
     When current is caused to flow through the coils  84 , and by magnetic flux generated from the coils  84 , the orientations of the poles of the hard magnetic bodies  83  are made as illustrated in  FIG. 6( a ) , that is, such that the pole of each hard magnetic body  83  facing each soft magnetic body  82  is the same as the pole of the hard magnetic body  81  facing the each soft magnetic body  82 , magnetic fluxes from the soft magnetic bodies  82  passes through the flange portion  32   c,  which causes the flange portion  32   c  to be attracted to the magnet clamp  80 . This state is kept even when the current through the coils  84  is stopped. 
     In contrast, when current in the reverse direction is caused to flow through the coils  84  and by magnetic flux generated from the coils  84 , the orientations of the poles of the hard magnetic bodies  83  are made as illustrated in  FIG. 6( b ) , that is, such that the pole of each hard magnetic body  83  facing each soft magnetic body  82  is the reverse of the pole of the hard magnetic body  81  facing the each soft magnetic body  82 , magnetic fluxes between the hard magnetic bodies  81  and the hard magnetic bodies  83  passes through the soft magnetic bodies  82 , and there are few magnetic fluxes passing through the flange portion  32   c.  Therefore, the flange portion  32   c  is not attracted to the magnet clamp  80 . This state is kept even When the current through the coils  84  is stopped. 
     &lt;Extrusion Molding Device According to Third Embodiment&gt; 
     Subsequently, an extrusion molding device according to a third embodiment will be described. As illustrated in  FIG. 7  and  FIG. 8 , the extrusion molding device according to the present embodiment is one in which the flow adjustment plate  20  is replaced with a flow adjustment plate  20 A, so as to achieve a further uniformity of flow rate between the central portion and the periphery of the channel. The flow adjustment plate  20 A includes a main member  201 , a sheet member  202 , and a core member  204 . The main member  201  assumes a disk shape the center of which has an opening  203 . The main member  201  is formed with a plurality of through holes  205  that are parallel to the central axis CL 1  of the channels  18   b  and  32   b.  The opening  203  is formed by hole portions  203   a,    203   b,  and  203   c  that run from an upstream side to a downstream side (see  FIG. 9 ). The inner diameter of the hole portion  203   a  on the upstream side is larger than the inner diameter of the hole portion  203   b  in the middle, and the inner diameter of the hole portion  203   c  on the downstream side is smaller than the inner diameter of the hole portion  203   b.  The sheet member  202  is disposed on the upstream side of the main member  201 , covering a surface  201   a  on the upstream side of the main member  201 . The sheet member  202  is formed with a net (not illustrated) through which the composite material is caused to pass. 
     As illustrated in  FIG. 9  to  FIG. 11 , the core member  204  assumes a disk shape with a plane  204   a  facing the upstream side and a plane  204   b  facing the downstream side and is disposed in the opening  203  of the main member  201 . The core member  204  includes a fitted portion  204   c  that is fitted to the hole portion  203   b  of the opening  203 , a large-diameter portion  204   d  that is adjacent to the fitted portion  204   c  on a plane  204   a  side, and a small-diameter portion  204   e  that is adjacent to the fitted portion  204   c  on a plane  204   b  side. The large-diameter portion  204   d,  which is large in outer diameter as compared with the fitted portion  204   c,  is housed in the hole portion  203   a  on the upstream side of the opening  203 . The small-diameter portion  204   e,  which is small in outer diameter as compared with the fitted portion  204   c,  is inserted into the hole portion  203   c  on the downstream side of the opening  203 . 
     By the fitted portion  204   c  being fitted to the hole portion  203   b,  the position of the core member  204  in a direction orthogonal to the central axis CL 1  is determined. By the large-diameter portion  204   d  being caught on the boundary portions of the hole portions  203   a  and  203   b  of the opening  203 , the movement of the core member  204  toward the downstream side is restricted. In contrast, by the sheet member  202 , the movement of the core member  204  toward the upstream side is restricted. The core member  204  is thereby retained in the opening  203 . 
     As illustrated in  FIG. 10  to  FIG. 15 , the core member  204  is formed with inclining through holes  206 ,  207 ,  208 , and  209  that incline with respect to the central axis CL 1 . The inner diameters of the inclining through holes  206 ,  207 ,  208 , and  209  are identical to one another. The inclining through holes  206 ,  207 ,  208 , and  209  are formed so as not to intersect with one another in the core member  204 . Since the core member  204  forms a central portion of the flow adjustment plate  20 , the inclining through holes  206 ,  207 ,  208 , and  209  are positioned close to the center of the flow adjustment plate  20 A. 
     As illustrated in  FIG. 10 ,  FIG. 11 , and  FIG. 12 , the inclining through holes  206  is formed at four positions at which a circumference along the outer circumference of the core member  204  is equally divided. Each inclining through hole  206  inclines with respect to the central axis CL 1  in a plane including the central axis CL 1 . The end portion on the upstream side of each inclining through hole  206  is positioned close to the central axis CL 1 . At the center of the plane  204   a  on the upstream side, a recessed portion  210  is formed, the inner surface of which assumes a cone shape, and the end portion on the upstream side of each inclining through hole  206  is opened on the inner surface of the recessed portion  210 . The end portion on the downstream side of each inclining through hole  206  is positioned close to the outer circumference of the core member  204  and is opened on the plane  204   b  on the downstream side. In such a manner, each inclining through hole  206  is formed so as to approach the central axis CL 1  as extending from the downstream side to the upstream side. 
     As illustrated in  FIG. 10 ,  FIG. 11 , and  FIG. 13 , the inclining through holes  207  are formed at eight positions at which a circumference along the outer circumference of the core member  204  is equally divided. Each inclining through hole  207  inclines with respect to the central axis CL 1  in a plane including the central axis CL 1 . The end portion on the upstream side of each inclining through hole  207  is positioned close to the central axis CL 1  and is opened on the inner surface of the recessed portion  210 . The end portion on the downstream side of each inclining through hole  207  is positioned close to the outer circumference of the core member  204  and is opened on the plane  204   b.  In such a manner, each inclining through hole  207  is formed so as to approach the central axis CL 1  as extending from the downstream side to the upstream side. 
     The end portions on the upstream side of the inclining through holes  207  are positioned on the outer circumference side of the core member  204  as compared with the end portions on the upstream side of the inclining through holes  206 , surrounding the end portions on the upstream side of the inclining through holes  206  in the recessed portion  210 . The end portions on the downstream side of the inclining through holes  207  are positioned on the outer circumference side of the core member  204  as compared with the end portions on the downstream side. of the inclining through holes  206 . 
     As illustrated in  FIG. 10 ,  FIG. 11 , and  FIG. 14 , the inclining through holes  208  are formed at four positions at which a circumference along the outer circumference of the core member  204  is equally divided. Each inclining through hole  208  inclines with respect to the central axis CL 1  in a plane including the central axis CL 1 . The end portion on the upstream side of each inclining through hole  208  is positioned close to the outer circumference of the core member  204  and is opened on the plane  204   a  on the upstream side. The end portion on the downstream side of each inclining through hole  208  is positioned close to the central axis CL 1 . At the center of the plane  204   b  on the downstream side, a recessed portion  211  is formed, the inner surface of Which assumes a cone shape. The end portion of on the downstream side of each inclining through hole  208  is opened on the inner surface of the recessed portion  211 . In such a manner, each inclining through hole  208  is formed so as to approach the central axis CL 1  as extending from the upstream side to the downstream side. 
     As illustrated in  FIG. 10 ,  FIG. 11 , and  FIG. 15 , the inclining through holes  209  are formed at  16  positions at which a circumference along the outer circumference of the core member  204  is equally divided. Each inclining through hole  209  inclines with respect to the central axis CL 1  in a plane including the central axis CL 1  of the core member  204 . The end portion on the upstream side of the inclining through hole  209  is positioned close to the outer circumference of the core member  204 . The end portion on the downstream side of each inclining through hole  209  is also positioned in the vicinity of the outer circumference of the core member  204  and is positioned close to the central axis CL 1  as compared with the end portion on the upstream side. In such a manner, each inclining through hole  209  is formed so as to approach the central axis CL 1  as extending from the upstream side to the downstream side. 
     The end portions on the upstream side of the inclining through. holes  209  are positioned on the outer circumference side of the core member  204  as compared with the end portions on the upstream side of the inclining through holes  208 . The end portions on the downstream side of the inclining through holes  209  are positioned close to the central axis CL 1  as compared with the end portions on the downstream side of the inclining through holes  206  and  207 . 
     According to the present embodiment, the composite material in the channel  18   b  passes through the through holes  205  or the inclining through holes  206 ,  207 ,  208 , and  209 . Material composition fluxes having passed through the inclining through holes  206 ,  207 ,  208 , and  209  flow in the channel  32   b  in directions that incline with respect to the central axis CL 1 . By forming the flows inclining with respect to the central axis CL 1 , the composite material fluxes are mixed with one another in directions orthogonal to the central axis CL 1 . For this reason, it is possible to reduce the variations of the composite material in fluidity in the directions orthogonal to the central axis CL 1 . 
     Since the inclining through holes  206 ,  207 ,  208 , and  209  are positioned close to the center of the flow adjustment plate  20 A, flows inclining with respect to the central axis CL 1  are generated in the central portion of the channel extending from the first pipe  10  toward the second pipe  50 . This causes composite material fluxes flowing through the central portion of the channel and composite material fluxes flowing through the periphery of the central portion to be mixed with one another. In an extrusion molding device, the fluidity of a composite material flux flowing through the central portion of the channel tends to be high as compared with the fluidity of a composite material flux flowing through the periphery of the central portion. Therefore, by mixing the composite material flux flowing through the central portion of the channel and the composite material flux flowing through the periphery of the central portion, it is possible to further reduce the variations of the composite material in fluidity in the directions orthogonal to the central axis CL 1 . 
     The inclining through holes  206 ,  207 ,  208 , and  209  are formed so as to approach the central axis CL 1  as extending from one end side (the upstream side or the downstream side) to the other end side. For this reason, by composite material fluxes passing through the inclining through holes  206 ,  207 ,  208 , and  209 , flows from the central portion toward the outside of the channel or flows from the outside toward the central portion of the channel are formed. This causes composite material fluxes flowing through the central portion of the channel and composite material fluxes flowing through the periphery of the central portion to be further better mixed with one another. Therefore, it is possible to further reduce the variations of the composite material in fluidity in the directions orthogonal to the central axis CL 1 . 
     In particular, the inclining through holes  206  and  207  are formed so as to approach the central axis CL 1  as extending from the downstream side toward the upstream side. The inclining through holes  208  and  209  are formed so as to approach the central axis CL 1  as extending from the upstream side toward the downstream side. For this reason, by the composite material fluxes flowing through the inclining through holes  206 ,  207 ,  208 , and  209 , both of the flows from the central portion of the channel toward the outside and flows from the outside toward the central portion of the channel are formed. This causes composite material fluxes flowing through the central portion of the channel and composite material fluxes flowing through the periphery of the central portion to be further better mixed with one another. Therefore, it is possible to further reduce the variations of the composite material in fluidity in the directions orthogonal to the central axis CL 1 . 
     Note that a plurality of core members  204  can be prepared that differ in inner diameter, number, disposition, or inclining direction of inclining through holes, and can be changed as appropriate in conformity with the composition or the like of composite material. For this reason, it is possible to further reduce the variations of paste in fluidity in the directions orthogonal to the central axis CL 1 . 
     The inclining through holes are not necessarily formed close to the center of the flow adjustment plate  20 A and can be formed in the main member  201 . In addition, a through. hole parallel to the central axis CL 1  may be formed in the core member  204 . The main member  201  and the core member  204  may be undetachably integrated. 
     &lt;Extrusion Molding Device According to Fourth Embodiment&gt; 
     Subsequently, an extrusion molding device according to a fourth embodiment will be described. The extrusion molding device according to the present embodiment is one in which the core member  204  in the third embodiment is replaced with a core member  212 . The core member  212  is also for achieving the uniformity of flow rate between the central portion and the periphery of the channel. 
     As illustrated in  FIG. 16  to  FIG. 21 , the core member  212  assumes a disk shape that has a plane  212   a  facing an upstream side and a plane  212   b  facing a downstream side. The core member  212  includes a fitted portion  212   c  that is fitted to the hole portion  203   b  of the opening  203 , a large-diameter portion  212   d  that is adjacent to the fitted portion  212   c  on a plane  212   a  side, and a small-diameter portion  212   e  that is adjacent to the fitted portion  212   c  on a plane  212   b  side. The large-diameter portion  212   d,  which is large in outer diameter as compared with the fitted portion  212   c,  is housed in the hole portion  203   a  on the upstream side of the opening  203 . The small-diameter portion  212   e,  which is small in outer diameter as compared with the fitted portion  212   c,  is inserted into the hole portion  203   c  on the downstream side of the opening  203 . 
     By the fitted portion  212   c  being fitted to the hole portion  203   b,  the position of core member  212  in a direction orthogonal to the central axis CL 1  is determined. By the large-diameter portion  212   d  being caught on the boundary portions of the hole portions  203   a  and  203   b  of the opening  203 , the movement of the core member  212  toward the downstream side is restricted. In contrast, by the sheet member  202 , the movement of the core member  212  toward the upstream side is restricted. The core member  212  is thereby retained in the opening  203 . 
     The core member  212  is formed by round-shaped stacked plates  213 ,  214 ,  215 ,  216 , and  217  that are stacked from the downstream side to the upstream side along the central axis CL 1 . The large-diameter portion  212   d  is provided in the stacked plate  217  on the upstream side. The small-diameter portion  212   e  is provided, in the stacked plate  213  on the downstream side. At the outer edge portions on the downstream side faces of the stacked plates  214 ,  215 ,  216 , and  217 , but not of the stacked plate  213  on the downstream side, projections  214   a,    215   a,    216   a,  and  217   a  are formed that project on the downstream side. At the outer edge portions on the upstream side face of the stacked plates  213 ,  214 ,  215 , and  216 , but not of the stacked plate  217  on the upstream side, recessed portions  213   b,    214   b,    215   b,  and  216   b  are formed that correspond to the projections  214   a,    215   a,    216   a,  and  217   a,  respectively. 
     By the projections  214   a,    215   a,    216   a,  and  217   a  being fitted to the recessed portions  213   b,    214   b,    215   b,  and  216   b,  respectively, the relatively rotational movements between the stacked plates  213 ,  214 ,  215 ,  216 , and  217  are prevented. This determines the relative positions between through holes  218 ,  219 ,  220 ,  221 , and  222  to be described later. The stacked plates  213 ,  214 ,  215 ,  216 , and  217  are fastened to each other by a bolt or the like. 
     As illustrated in  FIG. 16  and  FIG. 17 , in the stacked plate  213  that is the closest to the downstream side,  18  through holes  218  are formed. Among them, three through hole  218 A are disposed so as to surround a center C 1  of the stacked plate  213 . With the three through holes  218 A centered, the other through holes  218  are disposed in an equilateral triangle grid pattern. The end portion on the upstream side of each through hole  218  is subjected to chamfering. 
     As illustrated in  FIG. 16  and  FIG. 18 , in the stacked plate  214  adjacent to the stacked plate  213  on the upstream side,  60  through holes  219  are formed. Among them, three through holes  219 A are disposed so as to surround a center C 2  of the stacked plate  214 . With the three through holes  219 A centered, the other through holes  219  are disposed in an equilateral triangle grid pattern. The inner diameter of each through hole  219  is small as compared with the inner diameter of the through holes  218  of the stacked plate  213 . The end portion on the upstream side of each through hole  219  is subjected to chamfering. All the through holes  219  are connected to the through holes  218  of the stacked plate  213 , and there are some through holes  219  which are connected to a plurality of through holes  218 . Each through hole  218  of the stacked plate  213  is connected to a plurality of through holes  219 . 
     As illustrated in  FIG. 16  and  FIG. 19 , in the stacked plate  215  adjacent to the stacked plate  214  on the upstream side,  19  through holes  220  are formed. One of the through holes  220 A is disposed at a center C 3  of the stacked plate  215 . With the through hole  220 A centered, the other through holes  220  are disposed in an equilateral triangle grid pattern. The inner diameter of each through hole  220  is larger than the inner diameter of the through holes  219  of the stacked plate  214  and equal to the inner diameter of the through holes  218  of the stacked plate  213 . The end portion on the upstream side of each through hole  220  is subjected to chamfering. Each through hole  220  is connected to a plurality of through holes  219  of the stacked plate  214 . All the through holes  219  of the stacked plates  214  are connected to the through holes  220 , and there are some through holes  219  each of which is connected to a plurality of through holes  220 . 
     As illustrated in  FIG. 16  and  FIG. 20 , in the stacked plate  216  adjacent to the stacked plate  215  on the upstream side,  51  through holes  221  are formed. Among them, three through holes  221 A are disposed so as to surround a center C 4  of the stacked plate  216 . With the three through holes  221 A centered, the other through holes  221  are disposed in an equilateral triangle grid pattern. The inner diameter of each through hole  221  is small as compared with the inner diameter of the through holes  218  and  220  of the stacked plates  213  and  215  and equal to the inner diameter of the through holes  219  of the stacked plate  214 . The end portion on the upstream side of each through hole  221  is subjected to chamfering. All the through holes  221  are connected to the through holes  220  of the stacked plate  215 , and there are some through holes  221  each of which is connected to a plurality of through holes  220 . Each through hole  220  of the stacked plate  215  is connected to a plurality of through holes  221 . 
     As illustrated in  FIG. 16  and  FIG. 21 , in the stacked plate  217  that is the closest to the upstream side,  18  through holes  222  are formed. Among them, three through holes  222 A are disposed so as to surround a center C 5  of the stacked plate  217 . With the three through holes  222 A centered, the other through holes  222  are disposed in an equilateral triangle grid pattern. That is, the through holes  222  are disposed as with the through holes  218  of the stacked plate  213  that is the closest to the downstream side. The inner diameter of each through hole  222  is large as compared with the inner diameter of the through holes  219  and  221  of the stacked plates  214  and  216  and equal to the inner diameter of the through holes  218  and  220  of the stacked plates  213  and  215 . The end portion on the upstream side of each through hole  222  is subjected to chamfering. Each through hole  222  is connected to a plurality of through holes  221  of the stacked plate  216 . All the through holes  221  of the stacked plate  216  are connected to the through holes  222 , and there are some through holes  221  each of which is connected to a plurality of through holes  221 . In addition, in the stacked plate  213 , each of nine through holes  218 B surrounding the three through hole  218 A closest to a center C 1  side is connected to the through holes  222 A and  222 B that are closest to a center C 5  side and closest to an outer edge side, respectively, of the stacked plate  217 , via the through holes  219 ,  220 , and  221  of the stacked plates  214 ,  215 , and  216 . 
     According to the present embodiment, composite material in the channel  18   b  flows into the through holes  205  or the through holes  222 . Composite material fluxes flowing into the through holes  222  flow into the through holes  221  connected to the through holes  222 . Since each through hole  222  is connected to a plurality of through holes  221 , a composite material flux having passed through each through hole  222  is separated and flows into a plurality of through holes  221 . Since there are some through holes  221  each of which is connected to a plurality of through holes  222 , the composite material fluxes flow from a plurality of through holes  222  into the through hole  221  and merge with one another. 
     The composite material flowing into the through holes  221  flows into the through holes  220  connected to the through holes  221 . Since there are some through holes  221  each of which is connected to a plurality of through holes  220 , a composite material flux having passed through the through hole  221  is separated and flows into a plurality of through holes  220 . Since each through hole  220  is connected to a plurality of through holes  221 , composite material fluxes flow from a plurality of through holes  221  into each through hole  220  and merge with one another. 
     The composite material flowing into the through hole  220  flows into the through holes  219  connected to the through holes  220 . Since each through hole  220  is connected to a plurality of through holes  219 , a composite material flux having passed through each through hole  220  is separated and flows into a plurality of through holes  219 . Since there are some through holes  219  each of which is connected to a plurality of through holes  220 , composite material fluxes flow from a plurality of through holes  220  into the through hole  219  and merge with one another. 
     The composite material flowing into the through holes  219  flows into the through holes  218  connected to the through holes  219 . Since there are some through holes  219  each of which is connected to a plurality of through holes  218 , a composite material flux having passed through the through hole  219  is separated and flow into a plurality of through holes  218 . Since each through hole  218  is connected to a plurality of through holes  219 , composite material fluxes flow from a plurality of through holes  219  into each through hole  218  and merge with one another. 
     In such a manner, the separation and merging of composite material occur in the course of passing through the five stacked plates  217 ,  216 ,  215 ,  214 , and  213 , which causes composite material fluxes to be mixed with one another in directions orthogonal to the central axis CL 1 . For this reason, it is possible to reduce the variations of composite material in fluidity in the directions orthogonal to the central axis CL 1 . 
     Each of the stacked plates  213 ,  214 ,  215 ,  216 , and  217  is disposed at the center of the flow adjustment plate  20 A. This causes the separation and merging of the composite material in the central portion of the channel, and composite material fluxes flowing through the central portion of the channel and composite material fluxes flowing through the periphery of the central portion are mixed with one another. As described above, the fluidity of a composite material flux flowing through the central portion of the channel tends to be high as compared with the fluidity of a composite material flux flowing through the periphery of the central portion. Therefore, by mixing the composite material flux flowing through the central portion of the channel and the composite material flux flowing through the periphery of the central portion, it is possible to further reduce the variation of the composite material in fluidity in the directions orthogonal to the central axis CL 1 . 
     The through holes  218 B formed in the stacked plate  213  on the downstream side are connected to the plurality of through holes  222 A and  222 B that are formed closest to the center C 5  side and closest to the outer edge side, respectively, of the stacked plate  217  on the upstream side, via the through holes  219 ,  220 , and  221  formed in the stacked plates  214 ,  215 , and  216  in the middle. For this reason, composite material fluxes flowing into the through holes  222 A formed closest to the center C 5  side in the stacked plate  217  on the upstream side and composite material fluxes flowing into the through holes  222 B formed closest to the outer edge side in the stacked plate on the upstream side flow one of the through holes  218  of the stacked plate  213  on the downstream side and merge with one another. This causes composite material fluxes flowing through the central portion of the channel and composite material fluxes flowing through the periphery of the central portion to be further better mixed with one another. Therefore, it is possible to further reduce the variations of the composite material in fluidity in the directions orthogonal to the central axis CL 1 . 
     In the stacked plates  214  and  216  in the middle, the through holes  219  and  221  are formed that are smaller in inner diameter and larger in number as compared to the through holes  218  and  222  of the stacked plates  213  and  217  on the upstream side and the downstream side. For this reason, the separation and merging of the composite material occur at more spots, which causes composite material fluxes to be further better mixed with one another in the directions orthogonal to the central axis CL 1 . Therefore, it is possible to further reduce the variations of composite material in fluidity in the directions orthogonal to the central axis CL 1 . 
     Note that a plurality of core members  212  can be prepared that differ in number of stacked plates, or in inner diameter, number, or disposition of the through holes of each stacked plate, and can be changed as appropriate in conformity with the composition or the like of composite material. For this reason, it is possible to further reduce the variations of composite material in fluidity in the directions orthogonal to the central axis CL 1 . 
     The stacked plates are not necessarily disposed at the center of the flow adjustment plate  20 A and may be disposed at a decentered position. In addition, the flow adjustment plate  20 A is not necessarily divided into the main member  201  and the core member  212 , and the entire flow adjustment plate  20 A may be formed by stacked plates. 
     The embodiments have been described above in detail, but the present invention is not limited to the above embodiments. For example, in the above embodiments, the description has been made about, by way of example, the aspect in which the first pipe  10  includes the extended portion  14 , the tapered portion  16 , and the adjustment plate fixing section  18 , but the embodiments can be practiced even if the flow adjustment plate  20  or  20 A is provided in the outlet of the barrel portion  12 . That is, the form of the first pipe  10  is not specially limited, and one or more screws may be disposed on an upstream side and the flow adjustment plate  20  or  20 A may be disposed on the upstream side of the second pipe  50 . Note that, when the first pipe  10  includes the tapered portion  16  the inner diameter of which is expanded as compared with the barrel portion  12 , there is an advantage that a molded body having a diameter larger than the inner diameter of the channel  12   b  can be manufactured. 
     In addition, in the above embodiments, the second pipe  50  includes the fourth portion  38  and the fifth portion  40  but may not include the fourth portion  38  and the fifth portion  40 , and the die  90  may be directly fastened in the outlet of the third portion  36 . In addition, the second pipe  50  may include another tubular portion, other than the fourth portion  38  and the fifth portion  40 , on the downstream side of the third portion  36 . 
     In addition, the form of the flow adjustment plate  20 , and the structure for fastening the flow adjustment plate  20  or  20 A between the first pipe  10  and the second pipe  50  are not specially limited. 
     In addition, the structures of the hydraulic clamp  60  and the magnet clamp  80  according to the above embodiments, the structures for attaching the hydraulic clamp  60  or the magnet clamp  80  to the first pipe  10 , and the clamp structure between them and the second pipe  50  are not limited to the above embodiments. 
     In addition, in the above embodiments, the hydraulic clamp  60  and the magnet clamp  80  are described by way of example, but the above embodiments can be practiced also by fastening the first pipe  10  and the first portion  32  of the second pipe  50  by the other fastening methods such as using a screw. 
     Also the cross-sectional shape of the channel of the first pipe  10  and the second pipe  50  is not limited to a circle, and may be an ellipse or a polygon. In this case, the inner diameter of the channel can be expressed as a circle equivalent diameter. 
     In addition, in the above embodiments, the cylindrical green honeycomb molded body  70  is described by way of example, but the shape and the structure of a molded body molded by the die  90  are not limited to this. The exterior shape of the green honeycomb molded body  70  may be, for example, a prism such as a quadrangular prism, or an elliptic cylinder. In addition, the disposition of the through holes  71   a  and  71   b  are not specially limited. For example, the disposition may not be an equilateral triangular disposition and may be, for example, a square disposition, a hexagonal disposition, or the like. Furthermore, also the shapes of the through holes  71   a  and  71   b  may not be hexagons, and may be, for example, triangles, quadrilaterals, octagons, round shapes, and the combinations thereof. 
     INDUSTRIAL APPLICABILITY 
     The present invention is applicable to the manufacture of a green honeycomb molded body. 
     REFERENCE SIGNS LIST 
       1  extrusion molding device
 
 2 A,  2 B screw
 
 10  first pipe
 
 20 ,  20 A flow adjustment plate
 
 32  first portion
 
 34  second portion
 
 35   a,    35   b,    35   c  region
 
 36  third portion
 
 50  second pipe
 
 60  hydraulic clamp
 
 70  green honeycomb molded body
 
 80  magnet clamp
 
 90  die
 
 201  main member
 
 203  opening
 
 204 ,  212  core member
 
 206 ,  207 ,  208 ,  209  inclining through hole
 
 212  core member
 
 213 ,  214 ,  215 ,  216 ,  217  stacked plate
 
 218 ,  219 ,  220 ,  221 ,  222  through hole
 
CL 1  central axis