JPH07227820A - Cast molding die and cast molding - Google Patents

Abstract

PURPOSE:To efficiently use a molding die for molding, then handle a molding without directly touching it, and prevent the molding from becoming deformed by installing additionally a shape retaining die for retaining the molding removed from the molding die, as a separate die from each split die, on the inner surface of a molding space. CONSTITUTION:A molding die for cast-molding is composed of split parts of a die surrounding a molding space, i.e., a top force 1, intermediate forces 2, 3 and a bottom force 4. In this case, a shape retaining die 5 for retaining a molding removed from the molding die is additionally installed, as a separate die from each split part 1 to 4 of a die, on a part of the inner surface of the molding space. The shape retaining die 5 is formed so that it surrounds the lateral surface of the molding. When cast-molding, first slurry is supplied into the molding die, and a liquid contained in the slurry is caused to become absorbed into the molding die to form the molding in the molding space. After that, the molding die is opened and is removed together with the shape retaining die 5. Finally the shape retaining die 5 is separated from the molding after the lapse of a specified time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a casting mold and a casting method for molding ceramic products, powder metallurgy products and the like. Specifically, the present invention relates to a casting mold and a casting method in which the use efficiency of the molding die is extremely high.

[0002]

2. Description of the Related Art In casting, a slurry in which raw material powder is dispersed in water or an organic solvent is used, and the slurry is poured into a porous molding die typified by gypsum, and the solvent is absorbed in the die to obtain a desired shape. It is a method of obtaining a molded body. Since this cast molding can easily mold a complex shaped product, its application to ceramic products using non-plastic raw materials is being actively studied.

In this cast molding, normally,
The molded body immediately after molding has poor handling property. Therefore, the particle size of the raw material powder is adjusted to form a high-density molded body, a binder is added to increase the strength of the base material, and further, the material is dried in the mold to some extent and then demolded.

[0004]

When a complex shaped product, a thin-walled product, etc. are manufactured by casting, the particle size distribution of the raw material powder is strictly adjusted in order to improve the shape retention and handling properties. It was necessary to densify by pressure casting and the like, and the molding operation was troublesome.

Further, in order to obtain a molded product having a good handling property, a sufficient amount of binder is added, the molded product is not immediately released from the mold after completion of the molding, and the molded product is gradually dried in the molding die.
After the contraction and mold release, an operation of removing the mold is performed, but in this case, the use efficiency of the molding die is low.

[0006]

A casting mold according to claim 1 is a casting mold having a plurality of split molds surrounding a molding space, wherein a part of the inner surface of the molding space is separate from the split mold. In the present invention, a shape-retaining die for retaining the shape of the molded body released from the molding die is provided.

According to a second aspect of the present invention, there is provided the casting mold according to the first aspect, wherein the shape-retaining die has a shape surrounding a side surface of the molded product.

According to the casting method of claim 3, the slurry is supplied into the casting mold of claim 1 or 2, and the liquid in the slurry is absorbed by the mold to form a molded body in the molding space. After that, the mold is opened, the molded body is taken out together with the shape-retaining mold, and after a predetermined time has passed, the shape-retaining mold and the molded body are separated.

In the present invention, as the mold, at least a part of the surface facing the molding space is made of various liquid absorbing materials such as gypsum, porous synthetic resin, porous metal and porous ceramics.

The mold may be made of a liquid-absorbent material as a whole, and all or part of the surface facing the molding space is made of a liquid-absorbent material, and the other parts are non-liquid-absorbent. It may be made of a conductive material. It should be noted that the portion of the surface facing the molding space, which is covered by the shape retaining mold, need not be made of a liquid absorbing material.

The molding die is composed of, for example, two points of an upper die and a lower die, or three points of an upper die, a lower die and a middle die (frame die). The middle mold is sandwiched between the upper mold and the lower mold. The upper mold, the lower mold or the middle mold may be composed of a plurality of split molds depending on the shape of the molded body.

When molding a hollow molded body, the core mold may be connected to an upper mold, a lower mold or a middle mold as required.

The shape-retaining die arranged in the molding die preferably has a shape surrounding the side surface of the molding in the molding space, but may have a shape surrounding the molding body from the upper surface to the lower surface. .

The shape-retaining type may be a liquid-absorbing type,
It may be non-liquid absorbent. When the shape-retaining mold is made to be liquid-absorbent, the thickness of the shape-retaining mold is selected to be a thickness commensurate with the required amount of liquid absorption. When the shape-retaining mold is made non-absorbent, it is preferable that the thickness of the shape-retaining mold is as thin as possible in consideration of the handling property of the shape-retaining mold and the pressure resistance of the molding die.

The slurry supplied into the molding die may be a slurry of ceramic raw material powder or a slurry of metal powder or synthetic resin powder.

The liquid of this slurry may be either water or an organic solvent. This slurry may contain an appropriate binder.

[0017]

When casting is carried out using the casting molds of claims 1 and 2, slurry is supplied into the molding space as in claim 3, and the liquid component in the slurry is transferred to the molding die (if If it is liquid-absorbent, it is also absorbed in this shape retention type.

By absorbing the liquid, a molded body is formed in the molding die. In the present invention, since the molded body is shaped by the shape-holding mold, even when the molded body has a high liquid content and the strength of the molded body is low, the mold is opened and the molded body is held. It can be taken out of the forming die together with the forming die. That is, even if the strength of the molded body is low, the molded body can be moved by gripping the shape retention mold. Further, since the shape-retaining mold protects the molded body, it does not break or crack.

The molded body protected by the shape-retaining mold is dried or, if the shape-retaining mold has a liquid-absorbing property, absorbed by the shape-retaining mold, whereby the strength is gradually increased, and Shrink and release from shape retention mold. Therefore, the shape-retaining mold and the molded body are separated. Even if the shrinkage of the molded product is small, the molded product and the shape-retaining mold may be separated when the molded product has sufficient strength.

In the molding die according to the second aspect, since the shape-retaining mold surrounds the side surface of the molding, it is easy to grasp the molding with the shape-retaining mold.

[0021]

Embodiments FIGS. 1 and 2 show a first embodiment,
The upper die 1, the middle dies 2, 3 and the lower die 4 constitute a molding die,
A cylindrical molding space is formed. A cylindrical shape retaining mold 5 is loaded in this molding space. Upper mold 1 and lower mold 4
Is made of a liquid absorbing material, and the middle dies 2 and 3 and the shape retaining mold 5 are made of a non-liquid absorbing material. Further, the inner surface of the slurry supply hole 6 provided in the lower mold 4 is made of a non-liquid-absorbent material 6a to prevent the slurry from solidifying in the hole 6.

After the mold is assembled as shown in FIG. 2, the slurry is supplied through the holes 6 so that the liquid is absorbed by the upper mold 1 and the lower mold 4.

Once the molded body is formed in the molding space,
Immediately, the mold is opened, the molded product is taken out together with the shape-retaining mold 5, and sent to the drying step. The upper mold 1, the middle molds 2, 3 and the lower mold 4 are immediately (or after being dried if necessary) assembled with a new shape-retaining mold 5 and used for molding.

FIGS. 3 to 5 show the second embodiment, in which the upper die 7 and the lower die 8 constitute a forming die, and the lower die 8
A cylindrical shape-preserving die 9 is loaded in a molding space formed by a circular recess provided in the. The upper mold 7 and the lower mold 8 are made of a liquid absorbing material, and the shape retaining mold 9 is also made of a liquid absorbing material of the same material.

A notch 10 is formed at the edge of the recess, which is provided for inserting a holding jig 11 or a fingertip when the shape retaining mold 9 is taken out.

After the mold is assembled as shown in FIG. 4, the slurry is supplied into the molding space through the slurry supply hole 12 of the lower mold 8.

When the molded body 13 is taken out, as shown in FIG. 5, the jig 11 and the fingertip are inserted into the notches 10 and the shape-holding die 9 is sandwiched and the shape-holding die 9 is taken out.

The molded body thus taken out is sent to the drying step together with the shape-retaining mold 9, and further absorbed into the shape-retaining mold 9 and dried, and thereafter, the shape-retaining mold 9 and the molded body are separated.

[0029]

According to the casting mold and the casting method of the present invention, the molding die can be efficiently used for molding.
Mold cost can be reduced. Further, since the molded body is taken out together with the shape-retaining mold from the molding die and the molded body can be handled without directly touching the molded body, deformation and chipping of the molded body can be prevented. In addition, the process can be easily automated. Furthermore, since it is sufficient to dry the molded body together with the shape-retaining mold only, the drying space is significantly reduced compared to the conventional example in which the molded body is dried for a long period of time while being built in the molding mold.

According to the second aspect, it becomes easy to handle the shape-retaining mold containing the molded body.

[Brief description of drawings]

FIG. 1 is a perspective view of a molding die according to a first embodiment.

FIG. 2 is a cross-sectional view of the molding die according to the first embodiment.

FIG. 3 is a perspective view of a molding die according to a second embodiment.

FIG. 4 is a cross-sectional view of a molding die according to a second embodiment.

FIG. 5 is a perspective view of the molding die according to the second embodiment when the die is opened.

[Explanation of symbols]

 1,7 Upper mold 2,8 Lower mold 3,4 Medium mold 5,9 Conservation mold

Claims (3)

[Claims] 1. A casting mold having a plurality of mold halves surrounding a molding space, wherein a molded body separated from the mold and separated from the mold is provided on a part of the inner surface of the molding space. A casting mold characterized by having a shape-retaining mold for retaining the shape. 2. The casting mold according to claim 1, wherein the shape-retaining mold has a shape surrounding a side surface of a molded product. 3. A slurry is supplied into the casting mold according to claim 1 or 2, and the liquid in the slurry is absorbed by the mold to form a molded body in the molding space, and then the mold is opened and molded. A cast molding method, wherein the body is taken out as it is with the shape-retaining mold, and after a predetermined time has passed, the shape-retaining mold and the molded body are separated.