JPH0214165B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method and apparatus for manufacturing ceramics, and more particularly to a method and apparatus for press-casting ceramics such as containers.

(Prior art) Traditionally, the casting method used in the production of ceramics has used a molding material called plastic slurry, which is made by mixing water with crushed porcelain clay or clay, or a mixture of water glass and soda carbonate instead of water. The molding material made into a slurry using a deflocculant is poured into a mold made of a stone frame mold, and left to stand for a while to form a thin layer of base material on the inner surface of the mold. A method called sludge casting was often used, in which the molded material was discharged and the molded product was removed from the mold once the base material became hard. In addition, in contrast to this method, methods suitable for mass production, such as the
As described in Publication No. 43486, there was a method in which slurry was injected under pressure into a plaster mold pressurized by an external holding mechanism, and the slurry was removed by injecting compressed air or the like.

(Problems to be Solved by the Invention) In the pressurized slurry injection and slurry removal methods using compressed air as described above, self-water-absorbing plaster molds are used, so the molds may wear out due to repeated use or dry out. There were various problems such as time loss.

(Means for solving the problem) In view of the above points, this method is generally referred to as a cast molding method, in which slurry is injected into a mold made of a material having a large number of capillaries, and then compressed air is injected into the mold. Insert a nozzle to feed the slurry, pressurize the inside of the mold, apply external pressure to the outside of the mold that can withstand the internal pressure of the mold, and provide a cavity under reduced pressure around the mold itself to remove the slurry. A method and apparatus for manufacturing ceramics, characterized in that a molded product is obtained by discharging water from a mold.

(Function) By using the manufacturing method and apparatus of the present invention, it is possible to shorten the molding time, to obtain ceramics that are suitable for mass production, do not deform even after firing, and have high product strength. This made it possible to expand the range of mold materials.

(Example) Hereinafter, the ceramic manufacturing method and apparatus of the present invention will be explained with reference to the drawings.

FIG. 1 is an explanatory diagram showing the main points of the manufacturing equipment used in the present invention. 1 is a water-conducting mold that is relatively hard and has a large number of capillaries, such as a hard ceramic mold called Ceraplast mold material or a metal mold. etc., and has a cavity 2 in the shape of a molded product,
Usually, there are two split molds, but depending on the molded product, three or more split molds may be used.
This mold 1 has a gate 3 that communicates with the cavity 2.
is placed face down on the molding base 16, and this is further set on the molding base 4. A through hole (gate) 5 for feeding and discharging the slurry into the cavity 2 is provided in the center of the molding table 4, and a conduit 6 for feeding and discharging the slurry is provided below the gate 5. They are installed consecutively. Further, a through hole 17 is formed in the center of the molding base 16 to match the gates 3 and 5 of the mold and the molding table. At this time, the gate 3 of the mold
and the through hole 5 of the molding table 4 are stacked and set so that they communicate with each other. Near the lower end of the conduit 6, a slurry injection pipe 7 and a slurry discharge pipe 8 are provided at a position slightly shifted from this, and an injection valve 9 and a discharge valve 10 are provided at the branch points, respectively, and a slurry discharge pipe 8 is provided at the branch point.
Inside is a slurry 6 injected into the mold cavity 2.
An air nozzle 11 for supplying compressed air is inserted near the gates 3 and 5 to discharge the remainder. A check valve 12 is formed at this tip. This conduit 8 is designed to automatically feed the slurry into the mold cavity 2, and although an air blowing nozzle 11 leading to the cavity 2 is not shown, it is connected to an air compressor to supply compressed air into the cavity 2 at any time. It is now possible to send it to

As described above, on the molding table 4, the outer frame 13 which can be divided into two is divided by an air cylinder or a hydraulic cylinder (not shown), etc., and is provided so as to be openable and closable from side to side. The lower end of this outer frame 13 can be sealed with the molding table 4. Along the inner wall of the outer frame 13, a presser frame 14 is fixed, which is made of circular rods made of a corrosion-resistant material such as plastic or stainless steel and has a mesh shape as shown in FIG. By regulating the size of exterior walls,
It is designed to apply an external force to the mold 1 integrally with the outer frame 13.

As described above, by providing the mesh-like presser frame 14 in stacked stages between the outer frame 13 and the mold 1, the hollow portion 18 is provided in the outer peripheral portion of the mold 1, and a part of the outer frame 13 is further provided. A vacuum conduit 19 is provided from the inside, and a vacuum pump (not shown) is connected to the tip of the conduit 19 via a valve 20 so that the outside of the mold 1 can be vacuumed.

The method for manufacturing ceramics of the present invention is carried out using the above-described apparatus. First, as shown in FIG. Through hole (gate) 3, 17,
Set so that 5 is connected. Next, as shown in FIG. 3, the outer frame 13 is closed to cover the mold 1, and the mold 1 is further pressurized via the press die 14. In a pressurized state, the valve 2
0 to reduce the pressure in the cavity.

On the other hand, on the slurry injection side, the valve 9 of the injection pipe 7 is opened while the valve 10 of the discharge pipe 8 is kept closed, and the slurry is poured from the slurry tank from the conduit 6 through the through holes 5, 17, and 3 into the cavity 2 of the mold 1. The inside of the feeding cavity 2 is filled with slurry 6 and pressurized for a certain period of time, and because the mold 1 is water-conducting with many capillaries, and because the cavity is depressurized, the inside of the cavity 2 and the outside of the mold 1 are Moisture is guided to the outside of the mold 1 by the pressure difference, and further, the water is discharged to the outside through the mesh of the presser frame 14 and the conduit 20, thereby forming a slurry to the desired thickness of the molded product m, which is the base material. agglomerates. Next, as shown in the explanatory diagram of FIG. 4, the valve 9 of the spouting pipe 7 is closed and compressed air is blown from the tip valve 12 of the air nozzle 11. If the desired thickness of the molded product is obtained in this way, the As shown in the explanatory diagram in FIG. 5, excess slurry is forcibly discharged from the mold 1 by opening the valve 10 of the discharge pipe 8 and introducing compressed air from the air nozzle 11, and then stopping the air blowing from the nozzle valve 12. .

In the final step, the pressure reducing valve 20 is closed, the outer frame is opened left and right as shown in FIG. 1, the mold is opened, the mold 1 is divided, and the molded product is taken out.

The method of the present invention is a casting method comprising the steps described above, and the mold 1 has two split molds in the embodiment shown in the drawings, but it is free to use more split molds. In addition, the external pressure to the mold must always be greater than the internal pressure of the mold.
For example, when obtaining a molded product with a capacity of 300 c.c. and a wall thickness of 3 m/m, the relative pressure difference is maintained at around ¹ Kg/cm2, and the working time from setting to removal is 3 minutes to form the specified shape. I got something. In addition, the released water is guided outside the formwork, so there is no problem during work.
It is possible to work on the next molding and can be operated continuously.

(Effects) The present invention provides a manufacturing apparatus and a manufacturing method using the same, in which a plasticized molding material is press-fitted into a mold, and during molding, a press frame is removed from the outside of the mold. The mold is uniformly pressurized at a higher pressure than the internal pressure through the mold, and the outside of the mold 1, which has water conductivity, is depressurized so that water is discharged to the outside and the slurry coagulates uniformly and firmly. It is possible to significantly shorten the molding time to obtain the desired thickness of the molded product, which shortens the overall molding time, minimizes the time for water to flow in the molding material, and makes the molding density high and uniform. This improves the strength of the molded product, allowing it to be molded into large dish-shaped containers and tall flower vases, which were previously difficult to mold, and preventing deformation after firing. Moreover, as ceramics with high dimensional accuracy can now be obtained, it has become possible to form screw threads on the opening of containers, which was difficult with conventional methods, to the same degree as plastic containers, making it possible to manufacture cream containers for cosmetics, for example. It became.

Furthermore, since a hard mold with many capillaries is used instead of a plaster mold as in the conventional method, it has high abrasion resistance, tensile strength, and bending strength, so it can be used repeatedly. Compared to self-absorbing plaster, it does not require a mold drying process, so it can be used continuously.

Therefore, the production equipment and method of the present invention can easily automate what previously relied on manual labor, making it possible to achieve uniformity of products, quality control, shortening molding cycles, and improving quality, thereby improving industrial production. It is possible to construct the most modern production line suitable for mass automation.

[Brief explanation of drawings]

The drawings are simplified process diagrams of the ceramic manufacturing method and apparatus of the present invention, FIG. 1 is a simplified explanatory diagram of the molding device showing the state before molding, and FIG. 2 is a diagram of the presser frame of the molding device shown in FIG. 1. 3 is a simplified diagram showing the slurry injection process, FIG. 4 is a simplified diagram showing the pressurizing process, and FIG. 5 is a simplified diagram showing the slurry discharge process. 1... Molding mold, 2... Cavity, 3... Gate, 4... Molding table, 5... Through hole, 6... Conduit, 7
... Injection pipe, 8 ... Discharge pipe, 9 ... Injection valve,
10...Discharge valve, 11...Air nozzle, 12
... Nozzle, 13 ... Outer frame, 14 ... Presser frame, 1
6... Molded pedestal, 17... Hole connected to one hole,
18...Cavity part, 19...Discharge conduit, 20...Valve, m...Molded product, a...Compressed air, b...Sludge, c...Water.

Claims (1)

[Scope of Claims] 1. When molding a device by injecting a slurry of a molding material into a mold made of a material having a large number of capillary tubes, the mold is set on a molding pedestal, and the molding pedestal is set on a molding pedestal. Then, each gate is aligned downward, and an outer frame to which a mesh-like presser frame with a hollow part communicating with the inner wall is fixed is placed so as to cover the outer periphery of the mold and make its lower end tightly contact with the molding table. set,
The mold is pressurized and the cavity is kept in a reduced pressure state. In this state, slurry is injected into the mold from the gate, and then pressure is applied for a predetermined period of time to drain moisture from the mold to the outside, and the mold is closed. After the slurry is agglomerated on the inner wall to a predetermined thickness, compressed air is sent through an air nozzle to draw out the remaining slurry, the outer frame is opened, the mold is divided, and the molded product is taken out. Production method. 2. When injecting a slurry of molding material into a mold to mold an object, a mold having a large number of capillary tubes is set downward, aligned with a molding pedestal, on top of it, and this molding pedestal is further placed on a molding pedestal. Similarly, a slurry guide tube is placed above the molding table and extends from the bottom of the molding table to the gate. Near the lower end of the guide tube, a slurry injection tube is separated from a slurry discharge tube at a slightly shifted position. Each branch point is provided with an injection valve and an extraction valve, as well as an air nozzle for feeding compressed air into the mold through the inside of the conduit, while on the outside of the molding table, the outer circumference of the mold is covered. , an outer frame that can seal the molding table at its lower end is provided so that it can be opened and closed left and right, and this outer frame is provided with a presser frame made of stacked rod-shaped objects in a mesh shape along the inner wall of the outer frame. The communicating cavity is connected from a part of the outer frame to a decompression pump through a conduit, so that the outer frame can pressurize the outside of the mold, and the cavity around the outer periphery of the mold can be reduced in pressure. Ceramic manufacturing equipment.