JP2593723B2 - Integral casting method and mold for ceramics - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a ceramic having a spout such as a teapot, a pot, a soy saucer, or a ceramic in which a body and a tube are integrated. TECHNICAL FIELD The present invention relates to a method of casting and molding a mold and a molding die thereof.

(Prior art)

2. Description of the Related Art Conventionally, for ceramics having a pipe portion such as a spout, a method of casting a slurry of a ceramic body in a molding die and integrally forming the same has been known (for example, Japanese Utility Model Application Laid-Open No. 58-28815, Japanese Patent Publication No.
No. 8-49246).

That is, as shown in FIG. 7, the molding die 8 comprises a plaster mold of an upper die 81, a middle die 82 and a lower die 83. The molding die 8 is assembled and a ceramic body 91 and a tube part to be obtained. This is for integrally casting 92.

Thus, the molding die 8 is used to mold the ceramic green body 9.
In casting, as shown in FIG. 9, first, the slurry of the ceramic body is poured into the assembled mold 8. After a certain period of time, the moisture of the slurry is absorbed by the gypsum mold, and a base layer having a certain thickness is formed. Next, the remaining slurry forming the base layer is discharged from the mold 8. A ceramic hydrogen-containing ground molded body (usually having a water content, that is, a moisture content of 13
(About 20% by weight), and after demolding, it is dried and shrunk (usually at a water content of about 1 to 10% by weight).

However, since the inner diameter of the pipe portion 92 is small, the vicinity of the opening end of the pipe portion 92 may be blocked by the slurry at the time of the casting (portion indicated by reference numeral 925). In particular, when the pipe 92 is bent, the tendency is remarkable when the pipe 92 has a small diameter even if it is straight.

Therefore, as shown in FIGS. 8a and 8b, the body 91 and the pipe 92 are separately cast without stopping and cast with great care so as not to block. At the boundary surface 93 between the body 91 and the pipe 92,
A method of joining with co-soil (ceramic ceramic slurry) must be implemented. The end of the spout of the pipe 92 is adjusted to have a good shape in the finishing step. Thus, a green body 9 as shown in FIG. 8c is obtained.

[Problem to be solved]

 However, the above prior art has the following problems.

That is, in the latter method, the body 91 and the tube 92 are separately formed separately, and after finishing the tube end, the two formed bodies are joined to each other, so that the work becomes complicated and inefficient. Bad nature. In addition, the joining between the body portion 91 and the tube portion 92 is not accurately performed, and local contraction, cracking, deformation, and the like occur at the boundary surface 93 in that case. For this reason, in such a boundary surface 93, a decrease in strength, an uneven thickness, or the like may occur.

SUMMARY OF THE INVENTION The present invention has been made in view of the conventional problems, and provides a method and an integrated mold for integrally casting ceramics, which are finished cleanly without blocking the vicinity of the opening end of the pipe portion, and are efficient and workable. What you want to do.

[Solutions to solve the problem]

The present application comprises a first invention relating to a casting method and a second invention relating to a molding die.

According to a first aspect of the present invention, there is provided a method for integrally casting a ceramic having a body and a tube having an opening end such as a spout by using a molding die. An elastic rubber plug having a protrusion having an outer shape corresponding to the inner shape near the open end of the pipe portion is detachably mounted, and is provided between the protrusion of the elastic rubber plug and the mold wall. Is provided with a stepped portion for maintaining a clearance corresponding to the wall thickness of the tube to be obtained, and forming an open end face connecting the outer surface and the inner surface of the tube with the protrusion of the elastic rubber plug. The present invention is an integral casting method of ceramics, characterized by casting mud into the mold, and removing the elastic rubber plug after draining.

In the first invention, the most remarkable point is that an elastic rubber plug having a projection having an outer shape corresponding to the inner shape near the opening end of the tube is detachably attached to the tube forming portion of the mold. The clearance between the projection of the elastic rubber plug and the mold wall, which is equivalent to the thickness of the tube to be obtained, is maintained, and the projection of the elastic rubber plug is attached to the outer surface of the tube. A stepped portion forming an open end face connecting the inner surface and the inner surface, and casting the slurry into the mold.

The tube forming part is a part where a pipe part such as a spout is to be formed. In addition, the above-mentioned inner shape means a shape on the inner side of the tube portion of the green body obtained by casting.

Further, as the elastic rubber stopper, one having a projection having an outer shape substantially the same as the inner shape and having a stepped portion forming an opening end surface is used. Also, the projection of the elastic rubber plug bends along the tube when it is mounted on the tube of the molding die, and when it is mounted at a predetermined position, it has such a shape as to form the inner shape of the tube of the molded body. Is an elastic body.

Examples of the material of the elastic rubber stopper include silicone rubber, urethane rubber, acrylic rubber, and nitrile rubber. Among them, the above-mentioned silicone rubber has no water absorption, has good drainage, is excellent in water resistance, and is excellent in releasability, moldability and precision. Therefore, dimensional stability is good,
Moreover, it has excellent durability.

In addition, the above-mentioned body part is a part which forms the main body of the ceramics,
For example, it is a main part of a container such as a teapot, a pot, a soy saucer and the like. Examples of the pipe section include a curved pipe section having a complicated shape or a straight pipe section, such as a spout for a teapot, a pot, or the like, or a bevel of a ceramic bird.

Further, in the first invention, a stepped portion which forms an open end connecting the outer surface and the inner surface of the tube portion is provided at the projection of the elastic rubber plug (the elastic rubber plug shown in FIGS. 1 and 3). (See step portions 121 and 122 of line 11). By providing the stepped portion, the opening end surface can be formed into a stepped shape that is clearly separated from the inner surface and the outer surface.

Next, a second invention is a mold for integrally casting a ceramic having a body and a tube having an opening end such as a spout, and the mold is provided with a body forming portion. An elastic rubber stopper having a projection having an outer shape corresponding to the inner shape near the opening end of the tube is detachably attached to the tube forming portion. The clearance between the projection of the elastic rubber plug and the mold wall is maintained so as to correspond to the thickness of the tube to be obtained, and the projection of the elastic rubber plug is connected to the outer surface of the tube. An integrated casting mold for porcelain, wherein a stepped portion forming an open end face connecting to the inner surface is provided.

In the second invention, the most remarkable point is that the mold has a body forming portion and a tube forming portion, and the tube forming portion corresponds to the inner shape near the opening end of the tube. An elastic rubber plug provided with a protruding portion having a contoured outer shape is detachably mounted, and a clearance equivalent to the wall thickness of the tube to be obtained is maintained between the protruding portion of the elastic rubber plug and the mold wall. In addition, a stepped portion is formed on the projection of the elastic rubber plug to form an open end face connecting the outer surface and the inner surface of the tube portion.

The molding die is made of, for example, dihydrate gypsum containing 0.1% or less of impurities of JISR9111 (porcelain gypsum).

The body forming part is a part where the body is to be formed by a casting method. Further, the tube forming portion has the same meaning as in the first invention.

The elastic rubber stopper having the above outer shape has the same meaning as in the first invention.

Also, the term "removable" means that it can be attached at the time of slurry casting and can be removed after forming the green body.

In addition, a stepped portion that forms an open end face connecting the outer surface and the inner surface of the tube portion is provided at the protrusion of the elastic rubber plug. This makes it possible to form a stepped open end face clearly separated from the inner surface and the outer surface at the open end of the ceramic tube.

The elastic rubber stopper is preferably made of silicone rubber. Thereby, the elastic rubber stopper does not absorb water, has good drainage, is excellent in water resistance, and is excellent in mold release property, moldability, and precision. Therefore, the dimensional stability is good and the durability is excellent.

[Action and effect]

In the casting method according to the first invention, first, the elastic rubber plug is detachably attached to the tube forming portion of the mold. Thus, a clearance corresponding to the wall thickness of the tube to be obtained near the opening end can be maintained between the projection of the elastic rubber plug and the mold wall. Also,
The open end face of the tube portion is formed simultaneously by forming a stepped portion in which the mold wall at the tube end portion of the tube forming portion comes close to and merges with the protrusion of the elastic rubber plug to have a desired shape. Therefore, by casting the slurry of the ceramic body in the forming mold and discharging the sludge, it is necessary to obtain a green body having a body and a pipe with a certain thickness and an open end face in the pipe. Can be. Then, after semi-dewatering to a water content of 13 to 20%, preferably about 15 to 18%, the elastic rubber plug is extracted from the green body.

Therefore, according to the first aspect of the invention, it is possible to provide an integrated cast molding method that does not block the vicinity of the open end of the pipe and that the open end is finished finely, is efficient, and has good workability. According to the present invention, the opening end face such as the spout end can be formed at the same time.
The finish forming step of the tube body is not required.

On the other hand, according to the second invention, it is possible to provide a molding die that can easily carry out the casting method according to the first invention.

〔Example〕

First Embodiment A method of integrally casting a ceramic and a molding die according to the present embodiment will be described with reference to FIGS.

That is, as shown in FIGS. 1 and 2, the molding die in this embodiment is a molding die 2 for integrally molding the ceramics 4 having a body 41 and a pipe 42 such as a spout. Mold 2
Has a body forming portion 21 and a tube forming portion 22. Also,
The tube forming portion 22 has an inner shape near the open end of the tube 42.
The elastic rubber plug 1 having the insertion cylindrical portion 12 having an outer shape corresponding to 420 is detachably mounted. In addition, elastic rubber stopper 1
Between the insertion cylindrical portion 12 and the mold wall 220 of the casting mold,
Clearance 32 equivalent to the thickness of the base layer of the pipe 42 to be obtained
The elastic rubber plug 1 is provided with stepped portions 121 and 122 which form an open end face connecting the outer surface and the inner surface of the tube portion 42.

As shown in FIG. 3, the elastic rubber plug 1 is
It has a stepped insertion column 12 that projects obliquely downward. The insertion cylindrical portion 12 is entangled with a curved cylindrical body 123 on the distal end side corresponding to the inner shape 420 near the open end of the tube portion 42 and a thick cylindrical body 124 located on the proximal end side. Are formed at the boundaries of the steps. The elastic rubber stopper 1 is made of silicone rubber having excellent water resistance, mold release, precision and durability.

The molding die 2 is formed of a gypsum mold having an inner wall corresponding to the outer shape of the teapot.

Thus, the inner shape 42 of the pipe 42 is
The elastic rubber plug 1 provided with the insertion cylindrical portion 12 having an outer shape corresponding to 0 is mounted.

In addition, a clearance 32 is formed between the insertion column 12 and the mold wall 220 of the tube forming portion 22 so as to correspond to the thickness of the base layer of the tube 42 to be obtained. The columnar body 124 is in close contact with the gypsum-type inner wall and has a stepped portion 121, 1 at its tip.
22 are formed.

Next, a method of integrally casting the ceramics 4 using the molding die 2 will be described with reference to FIGS.

First, the elastic rubber plug 1 is attached to the tube forming portion 22 of the molding die 2 (FIG. 1). As a result, a clearance 32 corresponding to the thickness of the base layer of the tube portion 42 to be obtained is formed between the insertion cylindrical portion 12 of the elastic rubber plug 1 and the mold wall 220, and the innermost gypsum mold inner wall portion has elasticity. The outer peripheral surface (FIG. 2) of the thick cylindrical body 124 of the rubber plug 1 is held tightly.
Next, the base slurry is cast into the molding die 2, and after the base layer has been formed, the elastic rubber plug 1 is removed in a semi-dehydrated state in which the mud is drained and the surface water inside the base is sufficiently evaporated. Here, the semi-dehydrated state refers to the state immediately before the start of drying shrinkage, that is, the rate-dependent drying of the substrate.

 Next, the effect of this example will be described.

In this example, the tube forming portion in the molding die 2
An elastic rubber plug 1 having an insertion cylindrical portion 12 having an outer shape corresponding to the inner shape 420 near the open end of the tube portion 42 is provided at 22.
Is installed. In addition, the curved cylinder 123 of the insertion cylinder 12
A clearance 32 corresponding to the wall thickness of the pipe section 42 to be obtained is formed between the inner wall of the gypsum mold and the thick cylindrical body 124 of the inserted cylindrical section 12 is tightly held on the innermost gypsum mold inner wall. Have been.

For this reason, the tube forming portion 42 has a small inner diameter and is bent, but since the insertion column portion 12 is provided, no blockage due to the slurry occurs. Further, for this purpose, the slurry is cast into the molding die 2 and discharged, so that the body portion has a predetermined thickness.
The tube 41 and the tube 42 can be integrally cast.

At the same time, the opening end face of the spout is also formed by the stepped portions 121 and 122 provided on the insertion cylindrical portion 12. Therefore, it is possible to simplify the work associated with molding such as finish molding of the spout end.

In this embodiment, since the elastic rubber plug 1 is made of silicone rubber, the elastic rubber plug 1 itself does not absorb water, drains well, and has excellent water resistance. The elastic rubber plug 1 has good releasability from a green body,
Excellent in moldability and precision. The elastic rubber plug 1 has good dimensional stability and high strength and elastic force, so that it has excellent durability.

Therefore, according to this example, the workability is good without closing the pipe part and without the need for finish molding of the open end face of the pipe part.
A method for integrally casting a teapot and a mold for the method can be provided.

Second Embodiment The casting method and the molding die according to the present embodiment
This will be described with reference to FIGS.

In other words, the present embodiment is different from the first embodiment in that
In place of the above, a "pot" pottery 5 is used. Correspondingly, the main body 13 of the elastic rubber plug 1 and
The shape of the insertion cylindrical portion 14 projecting obliquely downward from this is arranged substantially in the same shape as the inner shape of the tube portion 52, which is the spout of the "pot". That is, the insertion cylindrical portion 14 has a curved cylindrical body 143 that forms a clearance corresponding to the wall thickness of the tube portion 52, a thick cylindrical body 144 that is in close contact with the gypsum mold inner wall portion, and both cylindrical bodies 143, 1
And a stepped portion 141 formed between them. Other configurations were the same as those in the first embodiment. In the figure, reference numeral 51 denotes a body forming portion, and 53 denotes a handle portion.

Thus, according to the present embodiment, similar to the first embodiment,
It is possible to provide a method of integrally casting a "pot" and a mold for the same, which does not block the pipe portion and does not require finish molding of the opening end surface and has good workability.

Third Embodiment A casting method according to this embodiment will be described with reference to FIG.

That is, in this embodiment, a tube portion 521 having a petal-shaped opening 520 is used instead of the tube portion 52 of the "pot" ceramics 5 in the second embodiment.

In this example, the shape of the elastic rubber stopper corresponds to the inner shape of the tube portion 521 and has a molding surface forming the opening 520 (not shown). In other words, the elastic rubber stopper is formed in a petal shape near the boundary between the main body and the insertion column.

In this embodiment, the same effect as that of the second embodiment can be obtained, and a petal-shaped opening 520 can be simultaneously formed in the tube portion 521 of the ceramics 5 by using an elastic rubber stopper. Therefore,
There is no need to finish the opening 520 as the pipe end.

[Brief description of the drawings]

1 to 3 show a first embodiment, FIG. 1 is a sectional view of a casting mold, FIG. 2 is a perspective view of the casting mold, FIG. 3 is a perspective view of an elastic rubber stopper, and FIG. FIGS. 5 and 5 show a pot mold according to the second embodiment, FIG. 4 is a sectional view thereof, FIG. 5 is a perspective view thereof, and FIG. 6 is a tube portion of a "pot" according to the third embodiment. FIG. 7, FIG. 8, FIG. 8a, FIG. 8b, and FIG. 8c show conventional examples, FIG. 7 is a cross-sectional view of a conventional casting mold, FIG. The figure shows a cross section of the torso,
FIG. 8c is a cross-sectional view of the green body after joining in separate molding. DESCRIPTION OF SYMBOLS 1 ... Elastic rubber stopper, 11,13 ... Main part, 12,14 ... Insertion column part, 2 ... Casting mold, 21 ... Body forming part, 22 ... Tube forming part, 32 …… Clearance of tube forming part, 4… Porcelain, 41 …… Body, 42 …… Tube,

Claims (2)

(57) [Claims] In a method for integrally casting a ceramic having a body and a tube having an opening end such as a spout using a molding die, the tube forming portion of the molding die includes: An elastic rubber plug having a protrusion having an outer shape corresponding to the inner shape near the open end of the tube portion is detachably mounted, and between the protrusion of the elastic rubber plug and the mold wall. A stepped portion is formed at the protrusion of the elastic rubber plug to form an open end face connecting the outer surface and the inner surface of the tube, while maintaining a clearance corresponding to the thickness of the tube to be obtained. An integrated casting method for ceramics, which comprises casting a slurry into a mold, and removing the elastic rubber plug after draining. 2. A molding die for integrally casting a ceramic having a body and a tube having an opening end such as a spout, the molding die comprising a body forming part and a tube forming part. An elastic rubber stopper having a projection having an outer shape corresponding to the inner shape near the open end of the tube is detachably mounted on the tube forming portion; A clearance equivalent to the thickness of the tube to be obtained is maintained between the protrusion of the rubber plug and the mold wall, and the outer surface and the inner surface of the tube are connected to the protrusion of the elastic rubber plug. An integral casting mold for ceramics, comprising a stepped portion forming an opening end surface.