JP6954746B2 - Ceramic molded body manufacturing method and ceramic molded body manufacturing equipment - Google Patents

Description

The present invention relates to a method for producing a ceramic molded body and an apparatus for producing a ceramic molded body, which can be applied to, for example, a cylindrical horizontal stripe type solid oxide fuel cell.

Conventionally, as a solid oxide fuel cell, a cylindrical horizontal stripe type solid oxide fuel cell is known. In this cylindrical horizontal stripe type solid oxide fuel cell, a large number of fuel cell cells are arranged side by side on a porous cylindrical insulator base tube (that is, a support), and an interconnector or the like is used between them. It is connected.

The support of this cylindrical horizontal stripe type solid oxide fuel cell is usually extruded into a cylindrical shape using an extrusion molding machine, for example, using a clay-like extruded material, and cut to a desired length to form a molded product (that is, ceramic). It can be produced by producing a molded product), allowing it to stand naturally, drying it by heating, and then firing it.

Of these, cutting is generally done with a wire. For example, there is a method of cutting by moving the wire up and down near the base of the extrusion molding machine, and there is also a method of reducing the wire diameter in order to reduce the resistance applied at the time of cutting (see Patent Document 1 below). ..

Further, when the ceramic molded body is deformed, there are a method of correcting the shape (see Patent Document 2 below) and a method of discarding the deformed portion of the ceramic molded body after drying.
Further, in the case of a long cylindrical shape in which the length of the ceramic molded body exceeds 1.5 m, the tip of the ceramic molded body is crushed by its own weight because it takes time from being extruded to being cut. The cross section becomes elliptical.

As a countermeasure against this, a technique is known in which a ceramic molded body is rotated on a rotating roller to allow the ceramic molded body to be naturally dried while recovering the cross-sectional shape of the ceramic molded body to a certain degree (see Patent Documents 3 and 4 below).

Further, when drying a cylindrical ceramic molded body, a technique for uniformly drying the outside and the inside of the ceramic molded body by blowing air through a through hole at the center of the shaft of the stationary ceramic molded body. It is known (see Patent Document 5 below).

JP-A-2002-103324 Japanese Unexamined Patent Publication No. 2006-205526 Japanese Unexamined Patent Publication No. 2003-26466 Japanese Unexamined Patent Publication No. 2003-117917 Japanese Unexamined Patent Publication No. 6-335910

However, in the above-mentioned conventional technique, when the ceramic molded body after cutting is blown and dried while rotating, the drying is promoted, but when the hardening of the clay progresses excessively, the above-mentioned cross-sectional shape becomes a perfect circular shape. May hinder recovery.

If the recovery to the perfect circular shape is insufficient, it will hinder the processing while rotating the ceramic molded body in the subsequent printing process or the like, which is not preferable.
On the other hand, when it is important to delay the start of drying of the ceramic molded product and restore the above-mentioned cross-sectional shape to a perfect circular shape, the time required for sufficient drying becomes long. Further, in the device for transporting while drying, the transport distance becomes long, and the device becomes huge.

If the drying is insufficient, the strength of the ceramic molded product is insufficient, and there is a problem that the handling is deteriorated or the ceramic molded body is damaged in the subsequent firing step or the like.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to increase the degree to which the cross-sectional shape of the ceramic molded body is restored to a perfect circular shape (hereinafter referred to as "recovery degree") and to promptly. It is an object of the present invention to provide a method for producing a ceramic molded product and an apparatus for producing a ceramic molded product, which can be dried.

(1) The first aspect of the present invention relates to a method for manufacturing a ceramic molded body, which manufactures a cylindrical ceramic molded body having an axial length of 1.5 m or more.
The method for manufacturing this ceramic molded body includes an extrusion molding step of producing an extrusion molded body by extrusion molding, a cutting step of cutting the extrusion molded body to a predetermined length to produce a ceramic molded body, and rotating the ceramic molded body. A drying step of blowing air from the rear end side to the tip side in the extrusion direction of the ceramic molded body to dry the plurality of ceramic molded bodies rotating on the plurality of rotating rollers that can and can be conveyed is provided. ..

In the first aspect, the ceramic molded product is placed on a rotating roller and dried while being rotated. Then, at the time of this drying, the ceramic molded product is dried by blowing air from the rear end side (that is, the root side) in the extrusion direction toward the tip side.

The tip side of the ceramic molded body has been extruded for a long time, and is gradually crushed by its own weight. Therefore, it takes time to rotate the ceramic molded body to restore the perfect circular shape.

On the other hand, the rear end side of the ceramic molded body is immediately after being extruded, and its shape is almost maintained. That is, the degree of perfect circle is high on the rear end side of the ceramic molded body.
Therefore, in the first phase, the air is blown from the rear end side to the front end side of the ceramic molded body while rotating the ceramic molded body. As a result, the ceramic molded body having a high degree of perfect circle can be dried from the rear end side, while the tip side can be dried after increasing the degree of recovery, and a ceramic molded body having a high degree of perfect circle can be efficiently obtained. Obtainable.

By blowing air, moisture volatilized from the material (that is, clay) of the ceramic molded body is sent to the tip side at the rear end side of the ceramic molded body, so that the atmosphere on the tip side changes (that is, the humidity increases). .. Therefore, from this point as well, the flexibility of the material on the tip side can be maintained for a long time, and the degree of recovery can be increased by rotating the material during that period.

In this way, in the first aspect, there is a remarkable effect that the ceramic molded product can be quickly dried while ensuring the degree of recovery of the cross-sectional shape of the ceramic molded product. Further, this has an advantage that the work of processing the ceramic molded product while rotating it becomes easy, and the apparatus can be made compact in the apparatus of transporting the ceramic molded product while drying it.

In particular, when the ceramic molded body has a length of 1.5 m or more, the tip side is significantly crushed due to its own weight, and the shape recovery step is indispensable.
Further, in the first aspect, by shortening the drying time, the components of the rotating roller made of iron or the like are less likely to adhere to the ceramic molded body. Therefore, it is possible to suppress the deterioration of the performance of the ceramic molded product due to the adhered substance. For example, when a ceramic molded product is fired to form a sintered body and then a film is formed on the surface thereof, the film can be suitably formed on the surface of the sintered body.

Here, the ceramic molded product is formed by extruding and cutting a material (for example, clay) of the ceramic molded product, and has a softness that can be shaped by a rotating roller before drying. , A molded product that is cured by drying (hence, a molded product before firing).

Further, in the first phase, after rotating the ceramic molded body, it is possible to start blowing air at a predetermined timing. As the timing (timing) for starting the ventilation, an appropriate timing after the ceramic molded body is rotated can be adopted. By adjusting this timing, it is possible to quickly dry while achieving a high degree of recovery of the cross-sectional shape.

When the timing of the start of blowing air is early, quick drying can be realized, and when the timing of blowing air is late, a high degree of recovery of the cross-sectional shape can be realized. The wind speed at the time of blowing is preferably 0.5 m / s or more.

Further, it is desirable to start the blowing after the roundness of the ceramic molded product is restored to 70% or less by the rotation. As a result, it is possible to dry quickly while realizing a high degree of recovery of the cross-sectional shape.

Here, the roundness ratio [%] is the degree of roundness of the ceramic molded product, which is the maximum of the major diameter (that is, the through hole extending in the axial direction) when the ceramic molded product is viewed from the extrusion direction (that is, the axial direction). It is an index shown by using the diameter) and the minor diameter (that is, the minimum diameter of the through hole), and is represented by the following formula (1).

Roundness [%] =
{(Difference between major axis and minor axis after drying for a certain period of time / Difference between major axis and minor axis immediately after molding)} × 100 ... (1)
Here, the "fixed time" is the time from cutting the extruded body to the start of blowing air, and the "immediately after molding" is the time when the extruded body is cut into a ceramic molded body. ..

When the perfect circle ratio is small, it is close to a perfect circle. For example, when it is 60% or less, it can be considered that the state of the perfect circle immediately after extrusion has been sufficiently restored.
Further, the roundness ratio differs depending on the measurement position in the extrusion direction. Normally, the roundness ratio on the front end side in the extrusion direction is larger than that on the rear end side, and the value increases with time.

(2) The second aspect of the present invention is the method for manufacturing a ceramic molded body according to the first aspect, and the cutting step is a step of cutting the extruded molded body with a cutting blade, and is a cutting process of the extruded molded body. The cutting load is controlled by changing the speed of the cutting blade in.

If the load for cutting the extruded body is too large, the ceramic molded body after cutting may be deformed and the amount of deformation may be large.
On the other hand, in the second aspect, the amount of deformation of the ceramic molded body can be reduced by controlling the load applied to the pressed molded body at the time of cutting (that is, the cutting load). More specifically, as is clear from the experimental examples described later, the amount of deformation of the ceramic molded product can be reduced by reducing the cutting load (for example, reducing it to a predetermined value or less).

As a result, the degree of perfect circle on the rear end side of the ceramic molded body can be maintained high, so that it is also suitable for drying by blowing air from the rear end side to the tip side while rotating the ceramic molded body. ..

Further, the amount of deformation is the amount of deformation on the rear end side of the cut ceramic molded body, but the tip side of the extruded molded body left after cutting is also deformed in the same manner. Therefore, the tip side of the cut ceramic molded body is also deformed, and as a result, the deformation of the tip side of the ceramic molded body can be suppressed.

(3) The third aspect of the present invention is the method for manufacturing a ceramic molded body according to the first or second aspect, and in the extrusion molding step, the molding die for molding the extrusion molded body is an outer die. An inner die having a tip protruding in the extrusion direction from the tip of the outer die is provided, and in the cutting step, the cutting blade is moved from the outer peripheral side of the inner die toward the inner die to cut the extruded body. ..

In the prior art, when the ceramic molded body is cut with a wire, the ceramic molded body is deformed because a pulling force is applied at the beginning of cutting or at the end of cutting. In particular, when the ceramic molded body has a cylindrical shape, it cannot be supported by a surface and is easily deformed. Therefore, in the subsequent drying process, printing process, etc., there may be a problem when processing the ceramic molded product while rotating it.

On the other hand, in the third aspect, a cylindrical extrusion molded body (for example, ceramic) is extruded by using a molding die provided with an inner die (inner mold) and an outer die (outer mold). An extruded body made of a material) is formed. Then, with respect to this extruded body, the cutting blade is moved from the outer peripheral side of the inner die toward the inner die to cut the extruded body, so that deformation at the time of cutting can be suppressed.

That is, in the third aspect, since the inner die protrudes downstream from the outer die in the extrusion direction, a part of the extruded body on the tip end side is located on the outer peripheral side of the inner die. Therefore, when the cutting blade is pushed (pushed) into the extruded body located on the outer peripheral side thereof, there is an inner die so as to support the extruded body from the inside in the direction in which the cutting blade is pushed. Therefore, since the extruded body is not deformed to the inside (axis center side) of the inner die, the deformation of the extruded body at the time of cutting (and therefore the deformation of the ceramic molded body after cutting) is suppressed.

Further, since the deformation of the ceramic molded body is suppressed at the time of cutting, there is an advantage that the work of cutting the deformed portion of the end part again after the ceramic molded body is dried and cured can be reduced, and the material loss and the like can be reduced. ..

The material of the cutting blade is preferably a material softer than the material of the inner die. As a result, even when the cutting blade hits the inner die, there is little deformation or damage to the inner die, and therefore, there is an effect that the dimensional accuracy of the ceramic molded body is unlikely to decrease.

(4) The fourth aspect of the present invention relates to a ceramic molded body manufacturing apparatus for manufacturing a cylindrical ceramic molded body having an axial length of 1.5 m or more.
This ceramic molded body manufacturing apparatus rotates an extrusion molding machine that manufactures an extrusion molded body by extrusion molding, a cutting machine that cuts the extrusion molded body to a predetermined length to produce a ceramic molded body, and a ceramic molded body. A blower that blows air from the rear end side to the tip side in the extrusion direction of the ceramic molded body to dry the plurality of rotating rollers that can and can be conveyed and the plurality of ceramic molded bodies that rotate on the rotating rollers. And.

The fourth aspect has the same effect as the first aspect.
(5) The fifth aspect of the present invention is the ceramic molded body manufacturing apparatus according to the fourth aspect, in which the cutting machine has a cutting blade for cutting the extruded body and is in the cutting process of the extruded body. A mechanism for controlling the cutting load by changing the speed of the cutting blade is provided.

The fifth aspect has the same effect as the second aspect.
(6) The sixth aspect of the present invention is the apparatus for manufacturing a ceramic molded body according to the fourth or fifth aspect, and in the extrusion molding machine, the tip of the inner die protrudes from the tip of the outer die in the extrusion direction. The cutting machine is provided with a molding die, and the cutting machine has a cutting blade for cutting the extruded molded body extruded from the molding die, and the cutting blade moves from the outer peripheral side of the inner die toward the inner die to move the extruded molded body. Has a mechanism to cut.

The sixth aspect has the same effect as the third aspect.

According to the present invention, a cylindrical ceramic molded body having an end portion with little deformation can be obtained. Further, by blowing air from the root side of the ceramic molded body, the ceramic molded body can be dried in a short time while obtaining the effect of recovering the crushing of its own weight on the tip side.

<Each configuration of the present invention will be described below>
-A ceramic molded body is a cylindrical member containing ceramic as a main component (that is, the maximum content of solid components). Examples of the type of this ceramic include alumina, zirconia, mullite, spinel and the like. In addition to ceramic, other components such as glass may be contained.

The extruded body is a cylindrical (for example, cylindrical) molded body containing ceramic as a main component, which is formed by extruding an extruded material (for example, clay) having a predetermined viscosity by an extrusion molding machine. Since this extruded body is a molded body before cutting the ceramic molded body, the material thereof is also the same as that of the ceramic molded body.

The cutting blade is a cutting member that cuts an extruded body to form a ceramic molded body, and is, for example, a plate-shaped member made of resin or metal.
A molding die is a die for molding an extruded body from an extruded material (for example, clay) having a predetermined viscosity. The outer die is a tubular die that forms the outer peripheral surface of the extruded body, and the inner die is a die that is arranged on the axial center side of the outer die and forms the inner peripheral surface of the extruded body. be.

-The rotating roller is a roller that can rotate around the center of the shaft, and is a roller that mounts a ceramic molded body on itself and can convey the ceramic molded body as a part of, for example, a conveyor. .. Examples of the material of the rotating roller include a metal such as iron and aluminum and a material such as ceramic.

It is a front view which shows the manufacturing apparatus of 1st Embodiment. It is a top view which shows the manufacturing apparatus. It is a perspective view which shows the ceramic molded body. It is explanatory drawing which shows the arrangement of the cutting machine while breaking the molding die in the vertical direction. It is explanatory drawing which shows the state which saw the cutting machine, the inner die, etc. from the tip in the extrusion direction. It is explanatory drawing which shows the state which the mounting part, the cutting machine, a part of a conveyor, etc. are seen from the tip in the extrusion direction. It is a flowchart which shows the cutting process by a cutting machine. It is explanatory drawing which shows a part of the manufacturing process of a ceramic molded body. It is explanatory drawing which shows the state which the cutting machine, the inner die and the like in 2nd Embodiment are seen from the tip in the extrusion direction. It is explanatory drawing which shows the state which the cutting machine, the inner die, etc. in the 3rd Embodiment are seen from the tip in the extrusion direction. It is a graph which shows the experimental result.

Next, an embodiment of the method for producing a ceramic molded product and the apparatus for producing a ceramic molded product of the present invention will be described.
[1. First Embodiment]
[1-1. Configuration of ceramic molded product manufacturing equipment]
First, an apparatus for producing a ceramic molded article (hereinafter, simply referred to as a manufacturing apparatus) used in the method for producing a ceramic molded article according to the first embodiment will be described.

As shown in FIGS. 1 and 2, the manufacturing apparatus 1 of the first embodiment mainly includes an extrusion molding machine 5 that performs extrusion molding of the extrusion molded body 3, a cutting machine 7 that cuts the extrusion molded body 3. A mounting portion 11 (see FIG. 2) on which the cut ceramic molded body 9 (see FIG. 3) is placed, a conveyor 13 that conveys the ceramic molded body 9, and a blower 15 (see FIG. 3) that blows air to the ceramic molded body 9. 2) and. The rotary drying device 16 is composed of the conveyor 13 and the blower device 15.

Of these, as shown in FIG. 2, the cutting machine 7 is arranged on the tip side (right side of FIG. 2) of the extrusion molding machine 5, and the mounting portion 11 is arranged on the tip side of the cutting machine 7. There is. The conveyor 13 is arranged parallel to the ground in one lateral direction (upper side of FIG. 2) of the mounting portion 11, and the blower 15 is in a direction perpendicular to the transport direction (arrow B direction) of the conveyor 13. It is located on one side (left side of FIG. 2).

Hereinafter, each configuration will be described in detail.
<Extruder>
The extrusion molding machine 5 is a device for extruding and molding a cylindrical (that is, cylindrical) 3 and includes a cylindrical cylinder 17 and a molding die 19 arranged on the tip side of the cylinder 17.

The ceramic molded body 9 formed by cutting the extruded molded body 3 also has a cylindrical shape, and the ceramic molded body 9 is formed with a cylindrical through hole 9a (see FIG. 3) extending along the axis center. ing.

Here, the dimensions of the ceramic molded body 9 are, for example, 2.0 m in the range of 1.5 m to 2.5 m in length, 25 mm in the range of outer diameter 15 mm to 30 mm, and 20 mm in the range of inner diameter 10 mm to 30 mm. Can be adopted.

Of these, an extrusion screw (not shown) is arranged inside the cylinder 17 coaxially with the cylinder 17. This extrusion screw is a screw that pushes out the clay filled in the cylinder 17 in the extrusion direction (right direction in FIG. 1: arrow A direction) by rotation.

Further, as shown in FIG. 4, the molding die 19 is coaxial with the outer die 21 in a cylindrical shape arranged coaxially with the cylinder 17 and inside the outer die 21 (that is, on the axis center side). It is provided with a cylindrical inner die 23 arranged in.

The inner diameter of the tip of the outer die 21 is, for example, φ12 mm, and the outer peripheral surface of the ceramic molded body 9 is formed by the inner peripheral surface of the outer die 21.
On the other hand, the outer diameter of the tip of the inner die 23 is, for example, φ9.8 mm, and the outer peripheral surface of the inner die 23 forms the inner peripheral surface of the ceramic molded body 9.

Further, a part of the outer peripheral surface of the inner die 23 is covered with the outer die 21, and the tip of the inner die 23 protrudes from the tip of the outer die 21 to the tip side (right side in FIG. 4) by, for example, 10 mm. ..
The inner die 23 and the outer die 21 are made of a metal material such as stainless steel, and when the metal material is SUS304, the hardness is HB160.

<Cutting machine>
As shown in FIG. 5, the cutting machine 7 is a device that cuts the extruded body 3 extruded from the extrusion molding machine 5 perpendicularly to the extrusion direction.

The cutting machine 7 detects a pair of upper and lower cutting blades 25 (25a, 25b), each driving device 27 (27a, 27b) for driving each cutting blade 25 in the vertical direction, and a load applied to each cutting blade 25. It includes a load sensor 29 (29a, 29b) and a control device 31 that controls the operation of the drive device 27.

The control device 31 is an electronic control device provided with a well-known microcomputer or the like, and controls the operation of each drive device 27 based on the signal from each load sensor 29 to control the speed of each cutting blade 25. .. As a result, the load applied by each cutting blade 25 to the extruded body 3 is controlled to adjust the cutting state of the extruded body 3. As the drive device 27, a device using a well-known motor, air pressure, or the like can be adopted.

Each cutting blade 25 is, for example, a plate material made of nylon having a thickness of 2 mm (for example, MC nylon: a registered trademark). The hardness of the cutting blade 25 made of nylon is Rockwell hardness R120. Therefore, the cutting blade 25 is softer than the inner die 23.

Further, semicircular cutting edges 33a and 33b (33) are formed on the tip end side (inner die 23 side) of each cutting blade 25, respectively. The cutting edge 33 is a portion for cutting the extruded body 3, and has a shape in which the outer peripheral surface of the inner die 23 is brought into contact with the extruded body 23 so as to go around (that is, surround) in the circumferential direction after cutting. Specifically, each cutting edge 33 of each cutting blade 25 has a shape that abuts on a half-circumfering portion in the circumferential direction of the outer peripheral surface of the inner die 23. That is, the radius of each cutting edge 33 is the same as the radius of the inner die 23.

In the cutting machine 7 having such a configuration, the upper cutting blade 25 moves toward the axis center O side of the inner die 23, and the cutting edge 33 comes into contact with the outer peripheral surface (that is, the upper semicircular portion) of the inner die 23. At the same time, the lower cutting blade 25 moves toward the axial center O side of the inner die 23, and the cutting edge 33 comes into contact with the outer peripheral surface (that is, the lower semicircular portion) of the inner die 23, whereby the extruded body 3 To disconnect.

<Placement part>
As shown in FIG. 2, the mounting portion 11 has a long, flat upper surface extending along the extrusion direction, and is mounted on a base 37 on which the extruded compact 3 is placed and on the base 37. It is provided with a moving mechanism 39 for pushing out and moving the placed ceramic molded body 9 after cutting in the direction of arrow B.

The moving mechanism 39 includes a long plate member 41 and a pair of drive units (for example, drive units driven by a motor, air pressure, or the like) 43 for moving the plate member 41 in the direction of arrow B. Therefore, as shown in FIG. 6, by moving the plate material 41 horizontally to the ground and in the direction of arrow B by the drive unit 43, the ceramic molded body 9 can be moved in the transport direction and mounted on the conveyor 13. ..

<Conveyor>
As shown in FIG. 2, the conveyor 13 is a device having a rectangular shape in a plan view and arranged parallel to the ground, and one or a plurality of ceramic molded bodies 9 are mounted and moved in the transport direction.

As shown in FIG. 6, the conveyor 13 includes a chain 47 to which a large number of substantially T-shaped individual members 45 are connected, and a drive roller 49 (see FIG. 1) that rotates the chain 47 in the direction of arrow C. Each individual member 45 is provided with a plurality of 51s attached to the outer peripheral side thereof.

The rotary roller 51 is a cylindrical member made of metal such as iron, and is arranged horizontally and in parallel as shown in FIG. That is, they are attached so as to extend in the left-right direction of FIG. 2 and be sandwiched between the left and right chains 47.

Here, the adjacent rotating rollers 51 are arranged at intervals that do not come into contact with each other, and the ceramic molded body 9 is held so as not to fall by the pair of adjacent rotating rollers 51 so that the ceramic molded body 9 can rotate. Have been placed. Since the rotating rollers 51 are arranged in parallel, the width of this interval is constant at any position in the longitudinal direction.

As will be described later, the rotating roller 51 rotates the ceramic molded body 9 arranged between the rotating rollers 51 by rotating with a drive mechanism (not shown). The rotary roller 51 is configured to rotate in the same direction at the same rotation speed and to be transferred in the transport direction as the conveyor 13 operates.

<Blower>
As shown in FIG. 2, the blower device 15 connects a blower 53, which is a fan for generating wind, a blower portion 55 that sends the air from the blower 53 to the ceramic molded body 9, and the blower 53 and the blower portion 55. It is provided with a blower tube 56.

Further, a plurality of nozzles 57 are provided at the tip of the blower portion 55. The nozzles 57 are arranged at predetermined intervals along the transport direction so that air can be blown to and around a large number of ceramic molded bodies 9 mounted on the conveyor 13.

Specifically, the nozzles 57 are set in the direction of blowing air in the direction of arrow A, and are arranged at intervals at which the rotating rollers 51 are arranged. Further, the nozzle 57 is not arranged in the entire range along the transport direction of the conveyor 13, but is arranged on the rear end side in the transport direction in order to perform natural drying at the start of transport.

Specifically, the nozzle 57 is not arranged from the mounting portion 11 to about 1/3 of the conveyor 13 in the range from the mounting portion 11 to the end of the conveyor 13 (upper end in FIG. 2), and the conveyor. For example, eight are arranged in the range from about one-third of 13 to the end.

Then, the nozzle 57 blows air toward the ceramic molded body 9 and its surroundings from the rear end side in the extrusion direction toward the tip end side (that is, toward the arrow A direction). That is, the ceramic molded body 9 is dried by blowing air from the nozzle 57 along the extrusion direction.
[1-2. Manufacturing method of ceramic molded product]
Next, a method of manufacturing the ceramic molded body 9 will be described.
<Raw material preparation process>
As is well known, as a raw material for clay to be a ceramic molded product 9, a mixture of ceramic powder, resin powder and liquid component in a predetermined ratio is used.

The ceramic powder is variously selected depending on the application, and for example, zirconia is generally selected as a support for a fuel cell.
Cellulose resin or acrylic resin is generally selected as the resin powder. This resin powder is a binder that changes to a liquid state by mixing liquid components.

As the liquid component, water (pure water) is the main component, and well-known dispersants, lubricants, lubricants and the like are added thereto.
<Kneading process>
Next, clay is produced by kneading the raw material of the clay with a kneader. The kneading may be performed by the extrusion molding machine 5.

<Extrusion process>
Next, as shown in FIG. 1, this clay is charged into the cylinder 17 from the hopper 5a (see FIG. 1) of the extrusion molding machine 5.

In the cylinder 17, the extrusion screw is rotated to gradually push the clay toward the tip while kneading it.
By this extrusion, the clay is passed through the molding die 19 to form a cylindrical extruded body 3. The extruded body 3 is placed on a base 37 (see FIG. 6) and gradually moves toward the tip side with extrusion.

<Cutting process>
Then, when the extruded body 3 is extruded to a predetermined length (for example, 1500 mm or more), the pair of cutting blades 25 of the cutting machine 7 makes the ceramic molded body 9 having a length of 1500 mm, for example, at the die outlet. Cut at the position (cutting position). As a result, the ceramic molded body 9 is obtained.

As described above, the cutting machine 7 is equipped with a load sensor 29 for measuring the load applied to the cutting blade 25, and adjusts the speed of the cutting blade 25 while detecting the load at the time of cutting.
Here, for example, a case where cutting is performed by the control shown in FIG. 7 will be described.

In step 100 (denoted as S in the drawing) 100 of FIG. 7, the cutting blade 25 is moved at the initial set speed.
In the following step 110, the load sensor 29 detects the load applied to the cutting blade 25.

In the following step 120, it is determined whether or not the load applied to the cutting blade 25 is within the target predetermined range. If an affirmative judgment is made here, the process proceeds to step 140, while if a negative judgment is made, the process proceeds to step 130.

In step 130, the speed of the cutting blade 25 is controlled so that the load applied to the cutting blade 25 is within the target predetermined range, and the process returns to step 110. For example, if the load is too large, reduce the speed to reduce the load. On the contrary, if the load is too small, increase the speed and increase the load.

Since there is a certain relationship (for example, a proportional relationship) between the speed of the cutting blade 25 and the load (that is, the cutting load), the target load can be obtained by obtaining the relationship between the speed and the load in advance. The speed can be set.

On the other hand, in step 140, it is determined whether or not the disconnection is completed, and if an affirmative determination is made here, the process proceeds to step 150, while if a negative determination is made, the process returns to step 110.
Whether or not the cutting is completed is, for example, whether or not the cutting blade has reached the target position (the position where the cutting blade abuts on the inner die 23), or whether or not the load has suddenly increased due to the abutment on the inner die 23. It can be judged by.

In step 150, since the cutting is completed, a process of returning the cutting blade 25 to the original position is performed, and this process is temporarily completed.
The cutting load such that the deformation amount of the ceramic molded body 9 (that is, the deviation from the target outer diameter) is 0.5 mm or less is about 130 gf or less. Control the speed of 25. As will be described later, this amount of deformation is the amount of deformation on the end face on the rear end side in the longitudinal direction of the ceramic molded body 9.
<Drying process>
Next, as shown in FIG. 6, the ceramic molded body 9 is pushed out toward the conveyor 13 side (direction of arrow B) by the moving mechanism 39 and transferred onto the conveyor 13 (thus, the rotary drying device 16) in detail. Is placed on a rotating roller 51 and dried while being transferred.

Hereinafter, the drying step of drying using the rotary drying device 16 will be described step by step.
First, as shown in FIGS. 8A and 8B, the ceramic molded body 9 is placed on the pair of rotating rollers 51 with the long directions aligned. At this time, the ceramic molded body 9 is arranged so that the rear end side is on the blower 15 side (that is, the nozzle 57 side).

Next, the ceramic molded body 9 is rotated by rotating the rotating roller 51. For example, as shown in FIG. 8C, by rotating the rotary roller 51 in the direction of arrow D, the ceramic molded body 9 is rotated in the direction of arrow E. At this stage, drying is performed by natural drying without blowing air.

When drying by natural drying, it is preferable that the rotary drying device 16 is in a state of being separated from the surroundings, that is, in a state of drying in, for example, an airtight container.
Then, when a predetermined timing is reached after the rotation is started, the blower 53 starts blowing air, and the nozzle 57 blows air from the rear end side to the front end side of the ceramic molded body 9 to dry the ceramic molded body 9. As the wind speed at the time of blowing air, for example, 0.5 m / s or more can be adopted.

Specifically, as shown in FIG. 2, the ceramic molded body 9 is dried by moving the ceramic molded body 9 to the position where the nozzle 57 is arranged by the conveyor 13 and blowing air from the nozzle 57. ..

Here, as the timing to start blowing air, it is preferable that the roundness ratio on the tip side of the ceramic molded body 9 reaches a predetermined value (for example, 70% or less). For example, the speed at which the ceramic molded body 9 is moved is adjusted according to the position of the nozzle 57 so as to match this timing.

Then, when the ceramic molded body 9 is dried to a extent that it can be handled, the ceramic molded body 9 is taken out from the conveyor 13. It should be noted that the term “handleable” means that the timing at which the ceramic molded body 9 is dried to the extent that it does not break or crack even when the ceramic molded body 9 is lifted can be adopted. Alternatively, a drying time (complete drying time: hereinafter may be referred to as complete drying time) that does not deform even when the ceramic molded body 9 is lifted is determined in advance by an experiment or the like, and this complete drying time is obtained. The structure of the rotary drying device 16 (for example, the length of the conveyor 13) is designed so that it can be discharged in case.

Further, after the above-mentioned drying, warm air may be blown to further promote the drying.
<Measurement process>
Next, a measurement process for measuring the outer diameter dimension of the ceramic molded body 9 will be described.

At the time of drying described above, the outer diameter dimension of the ceramic molded body 9 is measured by the method shown below.
Here, for example, as shown in FIG. 8C, the laser distance measuring machines 61a and 61b (61) are arranged above and below the ceramic molded body 9 (that is, above and below positions so as to sandwich the axis center). ..

The laser distance measuring machine 61 is arranged so as to measure the outer diameter of the measurement position near the rear end by, for example, 100 mm from the tip in order to measure the outer diameter on the tip side of the ceramic molded body 9.

Then, immediately after the ceramic molded body 9 is produced by cutting (within 10 seconds after cutting) and after drying for a certain period of time, each distance from the upper and lower laser distance measuring machines 61 to the surface of the ceramic molded body 9 is set to 0.1 seconds. Measure multiple times each time. That is, the measurement is performed 60 times per rotation.

Here, the "fixed time" is the time from the rotation of the ceramic molded body 9 to the start of blowing air.
Thereby, a plurality of outer diameters at the measurement position of the rotating ceramic molded body 9 can be obtained in a non-contact manner. Here, among the plurality of outer diameters obtained in one rotation, the largest one is the major diameter and the smallest one is the minor diameter.

Therefore, the perfect circle ratio can be calculated from the above equation (1) using the above-mentioned calculated values (major diameter, minor diameter).
<Post-process>
After drying, the completely dried ceramic molded body 9 is fired to obtain a ceramic tube (for example, an alumina tube) which is a ceramic support.
[1-3. effect]
Next, the effect of the first embodiment will be described.

(1) In the first embodiment, the ceramic molded body 9 having a length of 1.5 m or more is placed on the rotating roller 51 and dried while being rotated. Then, at the time of this drying, the ceramic molded body 9 is dried by blowing air from the rear end side (root side) in the extrusion direction toward the tip side.

The tip side of the ceramic molded body 9 has been extruded for a long time, and is gradually crushed by its own weight. Therefore, it takes time to rotate the ceramic molded body 9 to restore the perfect circular shape.

On the other hand, the rear end side of the ceramic molded body 9 is immediately after being extruded, and its shape is substantially maintained. That is, the degree of perfect circle is high on the rear end side of the ceramic molded body 9.
Therefore, in the first embodiment, while rotating the ceramic molded body 9, air is blown from the rear end side to the front end side of the ceramic molded body 9. As a result, the ceramic molded body 9 having a high degree of perfect circle can be dried from the rear end side having a high degree of perfect circle, while the front end side can be dried after increasing the degree of recovery. Can be obtained.

By blowing air, moisture volatilized from the material (that is, clay) of the ceramic molded body 9 is sent to the tip side at the rear end side of the ceramic molded body 9, so that the atmosphere on the tip side changes (that is, the humidity is high). Become). Therefore, from this point as well, the flexibility of the material on the tip side can be maintained for a long time, and the degree of recovery can be increased by rotating the material during that period.

In this way, in the first embodiment, there is a remarkable effect that the ceramic molded body 9 can be quickly dried while ensuring the degree of recovery of the cross-sectional shape. Further, this has an advantage that the work of processing while rotating the ceramic molded body 9 becomes easy, and the manufacturing apparatus 1 can be made compact.

Further, by shortening the drying time, the components of the rotating roller 51 made of iron or the like are less likely to adhere to the ceramic molded body 9. Therefore, it is possible to suppress the deterioration of the performance of the ceramic molded body 9 due to the adhered substance. For example, when the ceramic molded body 9 is fired to form a sintered body and then a film is formed on the surface thereof, the film can be suitably formed on the surface of the sintered body.

Further, according to the first embodiment, it is possible to mass-produce, for example, a support for a fuel cell having a cut end portion having a small crush.
(2) Further, in the first embodiment, by rotating the ceramic molded body 9 and then starting blowing air at a predetermined appropriate timing, it is possible to quickly dry the ceramic molded body 9 while achieving a high degree of recovery of the cross-sectional shape. ..

(3) Further, in the first embodiment, when cutting the extruded body 3, the cutting load is controlled by changing the speed of the cutting blade 25, so that the amount of deformation of the ceramic molded body 9 is reduced. be able to.

The amount of deformation is the amount of deformation on the rear end side of the cut ceramic molded body 9, but the tip side of the extruded molded body 3 left on the molding die 19 side after cutting is also deformed in the same manner. The tip side of the ceramic molded body 9 from which the extruded molded body 3 is cut is also deformed. Therefore, as a result, there is also an effect that the deformation of the tip side of the ceramic molded body 9 can be suppressed.

(4) Moreover, in the first embodiment, the molding die 19 has an outer die 21 and an inner die 23 protruding from the tip of the outer die 21 in the extrusion direction, and when cutting, the molding die 19 has an inner die 23. The cutting blade 25 is moved from the outer peripheral side of the inner die 23 toward the inner die 23 to cut the extruded body 3.

That is, when the cutting blade 25 is pushed (pushed) into the extruded body 3, the inner die 23 is provided in the direction in which the cutting blade 25 is pushed so as to support the extruded body 3 from the inside. The body 3 does not deform to the inside (axis center side) of the inner die 23. As a result, the deformation of the extruded body 3 at the time of cutting (thus, the deformation of the ceramic molded body 9 after cutting) is suppressed.

Further, since the deformation of the ceramic molded body 9 is suppressed at the time of cutting, it is possible to reduce the work such as cutting the deformed portion of the end part again after the ceramic molded body 9 is dried and cured, and it is possible to reduce the material loss and the like. There is.
[1-4. Correspondence with claims]
Here, the correspondence between the first embodiment and the claims will be described.

Ceramic molded body 9, extrusion molded body 3, rotary roller 51, cutting blade 25, molding die 19, outer die 21, inner die 23, manufacturing device 1, extrusion molding machine 5, blower device 15 of the first embodiment. Each corresponds to an example of the ceramic molded body, the extruded body, the rotary roller, the cutting blade, the molding die, the outer die, the inner die, the manufacturing apparatus, the extrusion molding machine, and the blower of the present invention.
[2. Second Embodiment]
Next, the second embodiment will be described, but the description of the same contents as that of the first embodiment will be omitted. As for the number of each configuration, the same number as that of the first embodiment is used.

As shown in FIG. 9, in the second embodiment, three cutting blades 71 (71a, 71b, 71c) are used.
The planar shape of each cutting blade 71 is a shape that surrounds the inner die 23 at an angle of 120 degrees when viewed from the tip side in the extrusion direction when the three cutting blades 71 are brought into contact with the inner die 23. It is said that.

Specifically, on the cutting side of each cutting blade 71, a cutting edge 73 that is curved corresponding to the outer shape of the inner die 23 (that is, along the outer circumference of the inner die 23) is formed.
Therefore, when cutting the extruded body 3, the extruded body 3 can be suitably cut by moving each cutting blade 71 to the axial center O side of the inner die 23 in the same manner.
[3. Third Embodiment]
Next, the third embodiment will be described, but the description of the same contents as that of the second embodiment will be omitted.

As shown in FIG. 10, in the third embodiment, four cutting blades 81 (81a, 81b, 81c, 81d) are used.
The planar shape of each cutting blade 81 is a shape that surrounds the inner die 23 at an angle of 90 degrees when viewed from the tip side in the extrusion direction when the four cutting blades 81 are brought into contact with the inner die 23. It is said that.

Specifically, on the cutting side of each cutting blade 81, a cutting edge 83 that is curved corresponding to the outer shape of the inner die 23 (that is, along the outer circumference of the inner die 23) is formed.
Therefore, when cutting the extruded body 3, the extruded body 3 can be suitably cut by moving each cutting blade 81 to the axial center O side of the inner die 23 in the same manner.
[4. Experimental example]
Next, an experimental example conducted for confirming the effect of the present invention will be described.

<Experimental example 1>
In Experimental Example 1, the ceramic of the present invention example used in the experiment is used under the following materials and the conditions (air blowing direction, wind velocity) shown in Table 1, while using the method for producing the ceramic molded product of the first embodiment. Samples of the molded product (Sample Nos. 2-5, 8 and 9) were prepared.

Then, the roundness ratio (A) at the start of ventilation, the time until complete drying (complete drying time), the final roundness ratio (B) (roundness ratio when completely dried: the perfect circle at the time of complete drying). Rate) was examined.
In addition, samples (Sample Nos. 1, 6 and 7) of Comparative Examples used in the experiment were also prepared by the same method as in the above invention example except for the conditions shown in Table 1 below, and each characteristic was examined in the same manner. ..

Hereinafter, a specific description will be given.
As the material of the clay of the sample used in the experiment, the methyl cellulose-based resin powder was 10 to 50% by weight (for example, 30% by weight) and the pure water was 10% by weight based on 100% by weight of the zirconia powder. A clay was prepared by adding ~ 25% by weight (for example, 15% by weight) and kneading with a kneader.

This clay was extruded and cut in the same manner as in the first embodiment to prepare a ceramic molded body having a specified size (1500 mm). The outer diameter of the ceramic molded product is about φ25 mm on average, and the inner diameter is about φ20 mm on average.

Then, the ceramic molded product was placed on a conveyor of a rotary drying device and placed on a rotary roller to be dried.
When the ceramic molded product was dried, the air blowing direction was set and the wind speed was set under the conditions shown in Table 1 below.

In addition, the outer diameter at the measurement position on the tip side of the ceramic molded body is measured with a laser distance measuring machine at the start of ventilation and at the time of complete drying, and the roundness (A) and final roundness at the start of ventilation are measured. (B) was requested. Further, the difference between the roundness ratio (A) at the start of ventilation and the final roundness ratio (B) (roundness ratio difference: AB) was determined. The results are also shown in Table 1 below.

Here, the blast was started when the roundness ratio (A) shown in Table 1 below was obtained. Further, the complete drying time is a time when sufficient strength is obtained to lift the ceramic molded product, and can be confirmed by actually lifting the ceramic molded product.

As shown in Table 1, when the sample No. 1 and the sample No. 2, the sample No. 7 and the sample No. 8 are compared with respect to the difference in roundness (AB), the sample No. 1 and the sample No. 8 of the comparative example are compared, respectively. It can be seen that the difference in roundness (AB) between Sample No. 2 and Sample No. 8 of the present invention is larger than that of Sample No. 7.

This difference in roundness ratio (AB) indicates the degree of improvement in the roundness ratio, and rather than blowing air from the front end side to the rear end side of the ceramic molded body, the air is blown from the rear end side of the ceramic molded body. It can be seen that the difference in roundness (AB) is larger when the air is blown toward the tip side. That is, it can be seen that the degree of recovery of the cross-sectional shape of the ceramic molded body can be increased by blowing air from the rear end side to the front end side of the ceramic molded body.

From Table 1, it can be seen that when the wind speed is 0.5 m / s or more, the complete drying time is 5 hours or less, that is, the higher the wind speed, the shorter the drying time. Further, it can be seen that when the roundness ratio (A) at the start of ventilation is 70% or less, the final roundness ratio (B) is smaller than when it exceeds 70%.

On the other hand, Sample No. 6 of Comparative Example in which air is not blown is not preferable because it takes a long time to completely dry for 24 hours and the surface is discolored due to the adhesion of iron.
<Experimental example 2>
Further, as Experimental Example 2, the relationship between the load of the cutting blade and the amount of deformation of the ceramic molded body caused by the load was investigated.

Specifically, a plurality of (18 pieces) ceramic molded bodies were produced by the same method as in the first embodiment.
At this time, the load applied to the cutting blade was adjusted as shown in FIG. 11 to cut the extruded molded product, and the amount of deformation of the ceramic molded product obtained thereby (that is, the amount of deformation on the rear end side) was examined.

This amount of deformation is a value obtained by subtracting the minimum outer diameter from the maximum outer diameter on the rear end side (root side) of the ceramic molded body. The measurement position on the rear end side is a position of about 10 mm from the rear end, and the laser distance measuring machine was arranged and used at the measurement position for measuring the outer diameter.

The result is shown in FIG. 11, and it can be seen that the larger the load (that is, the cutting load), the larger the amount of deformation. Specifically, since the cutting load such that the deformation amount is 0.5 mm or less is about 130 gf or less, it can be seen that it is preferable to control the speed of the cutting blade so as to have this cutting load.

Here, as shown in FIG. 11, the regression line of the experimental data is y = 0.0062x-0.3309, and the coefficient of determination R ² is 0.9142.
It is presumed that the reason why the rear end side of the ceramic molded body is deformed despite the presence of the inner die is the retention of clay inside the die.
[5. Other embodiments]
It goes without saying that the present invention is not limited to the above-described embodiment, and can be implemented in various embodiments without departing from the present invention.

(1) For example, in the first embodiment, the pair of cutting blades are arranged in the vertical direction and the extruded body is cut in the vertical direction, but the pair of cutting blades are arranged in the horizontal direction and the extruded body is oriented in the horizontal direction. May be cut into.

(2) The materials of the inner die, the outer die, and the cutting blade are not limited to the above-mentioned first embodiment and the like, and various well-known materials can be used.
(3) The shapes and arrangements of the conveyor, the rotating roller, and the nozzle are not limited to the above-described first embodiment and the like, and various shapes and arrangements can be adopted within the scope of the present invention.

For example, the extruded product may be placed directly on the conveyor without providing a mounting portion.
(4) The configurations of each embodiment can be combined as appropriate.
(5) The present invention is not limited to a ceramic molded body serving as a cylindrical support such as a cylindrical horizontal stripe type solid oxide fuel cell, and can be applied to various other methods for manufacturing a ceramic molded body.

For example, it can be applied to the manufacture of supports for fuel cells of other types such as solid oxide fuel cells. Further, it can be applied to the production of a long ceramic tube such as a roller of a firing furnace, a support used for ceramic filtration, and a protective tube of a thermocouple.

1 ... Manufacturing equipment 3 ... Extruded body 5 ... Extruded machine 7 ... Cutting machine 9 ... Ceramic molded body 15 ... Blower 19 ... Molding die 21 ... Outer die 23 ... Inner die 25, 71, 81 ... Cutting blade 51 ... Rotating roller

Claims (8)

A method for manufacturing a ceramic molded body, which manufactures a cylindrical ceramic molded body having an axial length of 1.5 m or more.
An extrusion molding process for producing an extrusion molded product by extrusion molding,
A cutting step of cutting the extruded body to a predetermined length to produce a ceramic molded body, and
A natural drying step in which the ceramic molded body is rotated on a plurality of rotatable and transportable rotating rollers and naturally dried.
After the natural drying step, the ceramic molded body is rotated on the plurality of rotating rollers, air is blown from the rear end side to the tip side in the extrusion direction of the ceramic molded body, and the tip is blown from the rear end side. A blast drying step of drying while sending the moisture volatilized from the ceramic molded body to the side,
A method for producing a ceramic molded product. The method for producing a ceramic molded product according to claim 1.
A calculation step of calculating the roundness of the ceramic molded product during the natural drying step, and a calculation step of calculating the roundness ratio of the ceramic molded product.
With
When the roundness calculated in the calculation step reaches a predetermined value, the natural drying step is switched to the blast drying step.
A method for manufacturing a ceramic molded product. The method for producing a ceramic molded product according to claim 1 or 2.
The cutting step is a step of cutting the extruded body with a cutting blade.
The cutting load is controlled by changing the speed of the cutting blade in the cutting process of the extruded body.
A method for manufacturing a ceramic molded product. The method for producing a ceramic molded product according to any one of claims 1 to 3.
In the extrusion molding step, the molding die for molding the extruded body includes an outer die and an inner die having a tip protruding in the extrusion direction from the tip of the outer die.
In the cutting step, the cutting blade is moved from the outer peripheral side of the inner die toward the inner die to cut the extruded body.
A method for manufacturing a ceramic molded product. A ceramic molded body manufacturing device that manufactures a cylindrical ceramic molded body with an axial length of 1.5 m or more.
An extrusion molding machine that manufactures an extrusion molded product by extrusion molding,
A cutting machine that cuts the extruded body to a predetermined length to produce a ceramic molded body, and
A plurality of rotating rollers capable of rotating and conveying the ceramic molded body, and
The ceramic molded body rotating on the rotating roller is blown from the rear end side to the tip side in the extrusion direction of the ceramic molded body, and volatilized from the ceramic molded body from the rear end side to the tip side. A blower that dries while sending the moisture,
With
The blower starts blowing after the ceramic molded body is naturally dried on the rotating roller.
Equipment for manufacturing ceramic molded products. The apparatus for manufacturing a ceramic molded product according to claim 5.
Further provided with a device for measuring the outer diameter of the ceramic molded product in order to calculate the roundness of the ceramic molded product is provided.
The perfect circle ratio is calculated from the outer diameter measured by the measuring device, and when the perfect circle ratio reaches a predetermined value, ventilation by the blower device is started.
Equipment for manufacturing ceramic molded products. The apparatus for manufacturing a ceramic molded product according to claim 5 or 6.
The cutting machine has a cutting blade for cutting the extruded body, and also has a cutting blade.
A mechanism for controlling a cutting load by changing the speed of the cutting blade in the cutting process of the extruded body is provided.
Equipment for manufacturing ceramic molded products. The apparatus for manufacturing a ceramic molded product according to any one of claims 5 to 7.
The extrusion molding machine includes a molding die in which the tip of an inner die protrudes in the extrusion direction from the tip of an outer die.
The cutting machine has a cutting blade for cutting the extruded body extruded from the molding die.
The cutting blade has a mechanism for cutting the extruded body by moving from the outer peripheral side of the inner die toward the inner die.
Equipment for manufacturing ceramic molded products.

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