JPH04115903A - Core for manufacturing ceramic hollow body - Google Patents

Abstract

PURPOSE:To enable manufacturing of a large quantity of molded bodies without necessitating an outer mold, by a method wherein the present core is constituted of an air transmitting core main body, a baggy and air transmitting resin film coating the core main body and a mouth piece filling an opening end of the resin film. CONSTITUTION:An annular body 4a of a mouth piece 4 is fitted to an opening part 14 of a core shaping mold 1, a heated and molten liquid air transmitting resin is cast into a spatial part 12 and when the surplus resin is caused to flow out and dried when a resin film 3 having a desired thickness is formed on an inner wall of the spatial part 12 and the annular body 4a of the mouth piece 4, a baggy resin film 3 having an opening end 18 is formed on the annular body 4a of the mouth piece 4. Then the opening end 18 is covered with a shield plate 5, a cylinder 4b of the mouth piece is screwed on to annular body 4a and the opening end 18 of the resin film 3 and the shield plate 5 are clamped down under a state where they are piled up each other. Then when the mold 1 is removed under a state where air is discharged by a vacuum pump and immersed into molding ceramic slurry 6, ceramics is deposited to the surface of the core.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a core used in manufacturing a ceramic hollow body.

[Prior Art] Conventionally, in the production of ceramic hollow bodies such as ceramic boat liners that are wrapped around cylinder head exhaust boats, paraffin, styrofoam, or low melting point material is used in an outer mold with a space equal to the outer shape of the hollow body. A core made of metal or the like that has the same shape as the inside of the hollow body is inserted, and ceramic slurry is poured into the space formed between the outer mold and the core. After dehydration and solidification, the molded product with the core is removed. Remove from the mold,
The molded product is taken out by melting or shrinking the core and removing it.

[Problems to be Solved by the Invention] However, the conventional manufacturing of ceramic hollow bodies uses a so-called slip casting method in which ceramic slurry is cast into a space formed between an outer mold and a core.
An outer mold was always required when manufacturing a hollow body. Therefore, in order to mass-produce hollow bodies, it is necessary to either increase the number of outer molds or increase the operating rate of the outer molds, but each has its limits. Further, in order to remove the core, the core is melted or shrunk, but there is a problem in that the molded body is destroyed due to expansion due to heating of the core at that time.

The present invention was made in order to solve the above-mentioned problems in the production of conventional ceramic hollow bodies, and it is possible to produce a large amount of molded bodies without the need for an outer mold when producing ceramic hollow bodies. An object of the present invention is to provide a core for manufacturing a ceramic hollow body, which can be removed in a simple process without heating and melting.

[Means for Solving the Problems] The core for producing a ceramic hollow body of the present invention comprises an air-permeable core body, a bag-shaped air-permeable resin film covering the core body, and the resin film. The gist is that the cap consists of a cap that closes the open end of the cap.

The material forming the core body may be any air-permeable material, and does not necessarily have to be solid, but may be an amorphous material such as powder or granules. As the air-permeable resin, for example, acetyl cellulose or the like can be used.

A vacuum pump hose is connected to the mouthpiece attached to the open end of the bag-shaped resin membrane, and the air inside the resin membrane is exhausted to create a reduced pressure state.

In the present invention, in order to form the core body, heated and molten liquid air-permeable resin is poured into a mold for molding the core, which has a product-shaped space with an opening at one end, and is cooled. When a resin film of a desired thickness is formed on the inner wall of the space, excess resin is poured out and dried. Next, the space in which the resin film is formed on the inner wall is filled with powder such as aluminum titanate and pressurized, and then the resin film is The interior becomes depressurized and the core maintains its shape even after the mold is removed.

[Function] The core for manufacturing hollow ceramic bodies of the present invention covers an air-permeable core body with an air-permeable bag-shaped resin film, and allows the inside of the core body to be penetrated through a cap that closes the open end of the resin film. Since the pressure has been reduced, the core can be immersed in a slurry tank containing ceramic slurry to form a ceramic hollow body by depositing ceramic on the surface of the core.

Therefore, when manufacturing the ceramic hollow body, there is no need to use an outer mold, and mass production can be performed at low cost.

In addition, when a core made of powder is used, removing the core simply involves taking out the powder, so there is no need to heat or divide the core when removing the core, and the molded product will not be damaged. Moreover, the powder taken out can be reused.

[Example] Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view illustrating the manufacturing process of the core body.

The core molding mold 1 is a mold having a product-shaped space 12, and the upper end of the space 12 is an opening 14 into which the die 4 is fitted. This core molding mold 1 has a space 1
2 can be divided into two molds 1a and 1b along a plane 16 that longitudinally traverses the molds 1a and 1b.

The cap 4 consists of an annular body 4a fitted into the opening 14 and a cylindrical body 4b screwed into the annular body 4a.After forming the resin film 3 on the annular body 4a, by screwing the cylindrical body 4b, The open end 18 of the resin film 3 is sandwiched. Further, a hose 20 of a vacuum pump is connected to the cylindrical body 4b.

To form the core body 2, the annular body 4a of the cap 4 is attached to the opening 14 of the mold 1 for molding the core, and heated and melted liquid air-permeable resin is poured into the space 12 and cooled. When the resin film 3 of a desired thickness is formed on the inner wall of the space 12 and the annular body 4a of the cap 4, excess resin is poured out and dried. A resin film 3 having a shape is formed. Next, a powder such as aluminum titanate is filled into the space inside the formed resin film 3 through the open end 18 to form the core body 2.

Next, the open end 18 is covered with a breathable shielding plate 5, and the cylindrical body 4b of the cap 4 is screwed into the annular body 4a, and the open end 18 of the resin film 3 and the shielding plate 5 are tightened with the overlapped state. , evacuate using a vacuum pump. When the core molding mold 1 is removed under the condition of being evacuated by a vacuum pump, the core body 2 can be taken out while maintaining the product shape since the inside of the resin film 3 is in a reduced pressure state.

The core thus shaped is immersed in a ceramic slurry 6 for molding, as shown in FIG. 2, while maintaining a reduced pressure state using a vacuum pump. In addition, in FIG. 2, 7 indicates a stirrer, and 8 indicates a holding jig.

When the core is immersed in the ceramic slurry 6 for molding,
Since the interior of the air-permeable resin film 3 is reduced in pressure through the cap 4 that closes the open end 18, ceramics adhere to the surface of the core. By the way, if the deposition speed is determined from the relationship between the degree of pressure reduction and the slurry viscosity, the core is pulled up from the ceramic slurry 6 when the desired deposition thickness is reached.

The core pulled up from the ceramic slurry 6 is as shown in FIG. 3, and a ceramic hollow body 9 is formed on the surface of the core.

To remove the core from the ceramic hollow body 9, the vacuum is released, the cap 4 and the shielding plate 5 are removed, the powdered core body 2 is poured out, the resin film 3 is pulled out, and the ceramic core is removed as shown in FIG. A hollow body 9 can be obtained.

[Effects of the Invention] As explained above, the core for manufacturing a ceramic hollow body of the present invention comprises an air-permeable core body, an air-permeable bag-shaped resin film covering the core body, and an air-permeable bag-shaped resin film that covers the core body. The mouthpiece that closes the open end of the resin membrane is hollow, and the inside of the core body is depressurized through the mouthpiece.By immersing it in a tank containing ceramic slurry, ceramics are deposited on the core surface and the ceramic hollow body is formed. You can mold your body. Therefore, when manufacturing the ceramic hollow body, there is no need to use an outer mold, and mass production is possible at low cost.

In addition, since a core made of powder can be used for the core body, the core can be removed by simply taking out the powder, and there is no need to heat or divide the core when removing the core. The molded body will not be damaged.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view explaining the molding process of the core body, Fig. 2 is a cross-sectional view showing the core immersed in ceramic slurry, and Fig. 3 is a cross-sectional view showing the state in which the core is immersed in ceramic slurry. FIG. 4 is a sectional view of the completed ceramic hollow body. 1...Mold for molding the core, 2...The core body, 3...
Resin film, 4... Cap, 5... Shielding plate, 6... Ceramic slurry 59... Ceramic hollow body Figure 1 Patent applicant Toyota Motor Corporation

Claims (1)

[Claims] (1) Production of a ceramic hollow body characterized by comprising an air-permeable core body, a bag-like air-permeable resin film covering the core body, and a cap that closes the open end of the resin film. Core for use.