JPH09122991A - Dry process isostatic pressure molding device and dry process isostatic pressure molding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to prevent the unequal thickness of a molding occurring in a clearance by providing the device with an expanding means which tightly fixes the outer peripheral surfaces of both ends of a rubber mold for molding to the inner peripheral surface of pressure medium sealing rubber by expanding both ends from the inner side. SOLUTION: A top plate 15 and a bottom plate 16 are mounted at the device, by which the rubber mold 4 for molding is forcibly expanded by as much as the part corresponding to clearance near the opening ends and is tightly fixed to the pressure medium sealing rubber 5. The effective means of prevent such movement of the rubber mold 4 for molding is to arrange one or >=2 projecting parts on the outer peripheral surface of the rubber mold 4 for molding so that the rubber mold 4 for molding and the possible medium sealing rubber 5 come into contact only at the peak surfaces of these projecting parts. As a result, the movement of the rubber mold 4 for molding is prevented and the easy attachment and detachment are executable.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a dry hydrostatic pressure molding apparatus and a dry hydrostatic pressure molding method for molding a cylindrical shape or a bottomed cylindrical shape.

[0002]

2. Description of the Related Art In general, dry isostatic pressing (hereinafter referred to as CIP molding) comprises powder filling, pressurizing, depressurizing, and unloading a molded body to form a cylindrical or bottomed cylindrical shape. It is preferably used.

The molding process by CIP molding will be described below.
A bottomed cylindrical shape will be described as an example with reference to FIGS. First, as shown in FIG. 7, molding powder A such as ceramic powder or metal powder is inserted and filled into the molding space 8 in the pressure container 2 via the powder supply nozzle 1. Here, the pressure vessel 2 has a molding space 8 formed therein from a columnar mandrel 3, a cylindrical molding rubber die 4, and a bottom punch 9 that supports the mandrel 3 from below. A pressure medium seal rubber 5 that surrounds the molding rubber die 4 is provided on the outer circumferential side of the rubber die 4 in the circumferential direction. A pressure medium inlet / outlet 6 is provided in the pressure vessel 2. Reference numeral 7 denotes a seal rubber holder.

The molding powder A inserted and filled in the molding space 8 in the pressure container 2 is obtained by inserting the top punch 11 having the top rubber stopper 10 into the upper part of the pressure container 2 and then, as shown in FIG.
As shown in FIG. 3, the pressure medium seal rubber 5 and the molding rubber mold 4 are pressurized by the pressure medium flowing from the pressure medium inlet / outlet 6 from the high pressure pump (not shown) via the pressure booster (not shown). Via compression molding. After the compression molding is finished, as shown in FIG. 9, the pressure medium is caused to flow out from the pressure medium inlet / outlet 6 to restore the molding rubber die 4, and then the top punch 11 is raised as shown in FIG. At the same time, the bottom punch 9 is lowered to take out the bottomed cylindrical molded body 12 from the pressure container 2.

By the way, the cylindrical shaped or bottomed cylindrical shaped product produced as described above is
High wall thickness accuracy may be required. For example, in the case of a β-alumina tube used in a sodium-sulfur battery, if the wall thickness is different depending on the site, that is, the wall thickness is uneven, the permeation of sodium ions becomes large in a thin portion which is advantageous in terms of electric resistance. . Therefore, only the thin-walled portion is selectively used, which results in accelerating the deterioration of the β-alumina tube. Further, in the thin portion, the heat resistance and mechanical strength of the β-alumina tube are reduced, which is not preferable. Therefore, it is necessary to minimize uneven thickness.

[0006]

SUMMARY OF THE INVENTION However, CI
In the P molding apparatus, a certain clearance is provided between the molding rubber mold and the pressure medium seal rubber, and the existence of this clearance causes the molding rubber mold to move during molding, resulting in uneven thickness on the molded body. Was the cause. On the other hand, if the clearance is simply reduced in order to suppress the uneven thickness, there is a problem that it becomes difficult to attach and detach the molded rubber mold and the pressure medium seal rubber due to the close contact. Furthermore, conventional CIP
In the molding device, from the viewpoint of avoiding an increase in uneven thickness,
The clearance cannot be made 0.5 mm or more, and with this level of clearance, when the molding rubber mold is attached and detached due to pressure bonding between the molding rubber mold and the pressure medium seal rubber due to pressure during molding, resistance may also occur. there were. In such a case, complicated work such as injecting high pressure air between them to form a gap between them has been required.

[0007]

Means for Solving the Problems The present invention has been made in view of such circumstances, and an object thereof is to provide a larger clearance between a molding rubber die and a pressure medium seal rubber. (EN) A CIP molding apparatus and a CIP molding method capable of preventing uneven thickness of a molded body due to the presence of the clearance.

That is, according to the present invention, the pressure medium seal rubber, the molding rubber die installed inside the pressure medium seal rubber with a certain clearance from the inner peripheral surface thereof, and the inside of the molding rubber die. After the raw material powder is filled into a cylindrical or bottomed cylindrical molding space having a columnar mandrel arranged, the outer peripheral surface is formed by the molding rubber mold, and the inner peripheral surface is formed by the mandrel, the molding rubber mold is formed. A dry hydrostatic pressure molding apparatus for molding a cylindrical body or a bottomed cylindrical body by applying hydrostatic pressure from the outer peripheral side of the molding machine, wherein both ends of the molding rubber die are expanded from the inside, Provided is a dry hydrostatic pressure molding apparatus having expanding means for closely fixing the outer peripheral surfaces of both end portions to the inner peripheral surface of a pressure medium seal rubber.

In the above-mentioned dry hydrostatic pressure molding apparatus, the expansion means are a top plate and a bottom plate that hold the molding rubber die from above and below, and the top plate and the bottom plate are inserted into the openings of the molding rubber die. Fixed to the molding rubber mold through the molding rubber mold holding part,
The molding rubber die holding portion has a taper portion whose maximum diameter is equal to or larger than the size obtained by adding the above clearance to the inner diameter of the opening of the molding rubber die, and the diameter of the insertion end of the molding rubber die. It is preferably equal to or smaller than the inner diameter of the opening.

Further, according to the present invention, a pressure medium sealing rubber, a molding rubber die installed inside the pressure medium sealing rubber, and a columnar mandrel arranged inside the molding rubber die are provided. After filling raw material powder into a cylindrical or bottomed cylindrical molding space whose outer peripheral surface is formed by a rubber mold and whose inner peripheral surface is formed by a mandrel, hydrostatic pressure is applied by a pressure medium from the outer peripheral side of the molding rubber mold. A dry hydrostatic pressure molding apparatus for molding a cylindrical body or a bottomed cylindrical body by applying a rubber mold for molding to a peripheral surface of 0.2 to 2.0.
The rubber mold for molding has one or more convex portions having a height of mm, and the rubber mold for molding is in contact with the pressure medium sealing rubber only on the top surface of the convex portions at normal pressure, and the convex portions are molded. The rubber mold for molding is appropriately arranged so as to be fixed at a fixed position in the pressure medium sealing rubber, and the total area of the top surface is 2 to 10% of the outer peripheral area of the molding rubber mold. A molding device is provided. The above-mentioned dry hydrostatic pressure molding apparatus, at least the upper end outer peripheral surface and the lower end outer peripheral surface of the rubber mold for molding,
It is preferable that the convex portion is provided over the entire circumference.

Further, according to the present invention, the pressure medium sealing rubber, the molding rubber die installed inside the pressure medium sealing rubber with a certain clearance from the inner peripheral surface thereof, and the molding rubber die inside the rubber die. A columnar mandrel arranged and a pressure container for accommodating the columnar mandrel, the outer peripheral surface of the molding rubber mold, the raw material powder into a cylindrical or bottomed cylindrical molding space whose inner peripheral surface is constituted by the mandrel. A dry hydrostatic pressure molding apparatus for molding a cylindrical body or a bottomed cylindrical body by applying hydrostatic pressure from the outer peripheral side of a rubber mold for molding after filling, further comprising the pressure vessel A top plate and a bottom plate respectively installed on the upper and lower parts of the molding rubber die in a state where the outer peripheral surface and the inner peripheral surface are in close contact with each other. And the bottom plate has a taper-shaped molding rubber die holding part inserted into the opening of the molding rubber die, and the molding rubber die is a metal having a tapered surface complementary to the molding rubber die holding part. The metal ring is held by a top plate and a bottom plate via a ring, and the metal ring is provided on the upper inner peripheral surface and the lower inner peripheral surface of the molding rubber die, and a metal ring holding portion having a shape complementary to the metal ring. Provided is a dry hydrostatic pressure molding apparatus which is installed in a molding rubber mold in a close contact state.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, both ends of the molding rubber die are expanded from the inside in order to prevent the molding rubber die from moving due to the clearance between the molding rubber die and the pressure medium sealing rubber. An expansion means is provided for tightly fixing to the inner peripheral surface of the pressure medium sealing rubber.

By this expansion means, both ends of the molding rubber die are spread out and pressed against the inner peripheral surface of the pressure medium sealing rubber, so that the molding rubber die can be fixed to the center of the pressure medium sealing rubber. It is possible to prevent uneven thickness of the molded body. Further, since a larger clearance can be provided between the molding rubber die and the pressure medium seal rubber,
The rubber mold for molding can be easily attached and detached.

FIG. 1 shows an example of a CIP molding apparatus having the above expansion means. In the CIP molding apparatus 14 of FIG. 1, a pressure medium sealing rubber 5 and a cylindrical molding rubber die 4 are installed inside the pressure vessel 2 with a certain clearance, and the inside of the molding rubber die 4 is A columnar mandrel 3 is provided. The upper and lower parts of the rubber mold 4 for molding are
A top plate 15 and a bottom plate 16 are provided, a top punch 11 is inserted in a hole 17 in the center of the top plate 15, and a bottom punch 9 is inserted in a hole 18 in the center of the bottom plate 16. Top plate 1
5 and the bottom plate 16 have a molding rubber mold holding portion 19 that is inserted into the open end of the molding rubber mold 4. The rubber mold holding portion 19 for molding has a tapered shape. As shown in FIG. 2, the diameter 20 of the insertion end is equal to the inner diameter 21 of the open end of the rubber molding die 4, and the maximum diameter 22 is for molding. It is a value obtained by adding the clearance 23 between the pressure medium seal rubber 5 and the molding rubber die 4 to the inner diameter 21 of the opening end of the rubber die 4.

Therefore, by mounting the top plate 15 and the bottom plate 16, the molding rubber mold 4
However, in the vicinity of the opening end, the molding rubber die 4 is pushed and expanded by an amount corresponding to the clearance 23, and the molding rubber die 4 is tightly fixed to the pressure medium seal rubber 5. The reason why the molding rubber mold holding portion 19 is formed in a taper shape is for convenience in mounting. In addition, in this example, the top plate 15 and the bottom plate 16 correspond to the above-mentioned expansion means. The diameter 20 of the insertion end may be smaller than the inner diameter 21 of the opening end of the molding rubber die 4, and the maximum diameter 22 should be a size that can be inserted into the opening end of the molding rubber die 4. For example, the inner diameter 21 of the opening end of the rubber mold 4 for molding
May be larger than the value obtained by adding the clearance 23 between the pressure medium seal rubber 5 and the molding rubber die 4.

In order to prevent the molding rubber mold from moving due to the clearance between the molding rubber mold and the pressure medium sealing rubber, one or more convex portions are arranged on the outer peripheral surface of the molding rubber mold. However, the molding rubber mold and pressure medium seal rubber are
It is also effective to adopt a configuration in which the contact is made only on the top surface of the convex portion. The convex portion is arranged at an appropriate position so that the movement of the molding rubber die in the pressure medium sealing rubber can be completely prevented.

With the above configuration, the molding rubber die is fixed at a predetermined position in the pressure medium seal rubber by the contact between the top surface of the convex portion and the pressure medium seal rubber.
While the movement of the molding rubber die in the pressure medium seal rubber can be prevented, the contact area between the molding rubber die and the pressure medium seal rubber is small, so that the molding rubber die can be easily attached and detached.

When the contact area between the molding rubber die and the pressure medium sealing rubber becomes large, it becomes difficult to attach and detach the molding rubber die. Therefore, the total area of the top surfaces of the convex portions is 2 times the outer peripheral area of the molding rubber die. It is preferably 10% to 10%, and more preferably 3% to 7%. Further, in order to facilitate the attachment and detachment of the molding rubber die, it is desirable that the height of the convex portion is 0.2 to 2.0 mm, more preferably 0.8 to 2.0 mm. Therefore, it is possible to provide a larger clearance between the molding rubber die and the pressure medium seal rubber than in the conventional case.

FIG. 3 shows an example of the CIP molding apparatus having the above-mentioned convex portion. In the CIP molding device 14 of FIG.
Inside the pressure vessel 2, a cylindrical molding rubber mold 4 is installed in a pressure medium sealing rubber 5, and a columnar mandrel 3 is arranged inside the molding rubber mold 4. Rubber mold for molding 4
On the outer peripheral surface, convex portions 25 having a height of 10 mm are formed over the entire circumference at four locations in the axial direction. At normal pressure, the molding rubber die 4 and the pressure medium sealing rubber 5 are in contact with each other only on the top surface of the convex portion 25.

Further, in order to prevent the movement of the molding rubber die caused by the clearance between the molding rubber die and the pressure medium sealing rubber, in order to prevent the movement of the molding rubber die, the pressure vessel and the top plate and the bottom plate, and the top plate and the bottom plate and the molding It is also effective to closely fix the rubber mold for use. If these members are closely fixed, rattling between these members can be prevented, and even if there is a clearance between the molding rubber die and the pressure medium seal rubber, the molding rubber die is kept in the pressure medium seal rubber. This is because it can be fixed at a predetermined position.

The pressure vessel and the top plate and the bottom plate are closely fixed to each other by bringing the outer peripheral surfaces of the top plate and the bottom plate into close contact with the inner circumferential surface of the pressure vessel over the entire circumference. Therefore, it is easy to process the outer peripheral surfaces of the top plate and the bottom plate so as to conform to the inner peripheral surface of the pressure vessel.

On the other hand, for tightly fixing the top plate and the bottom plate to the molding rubber mold, the molding rubber mold holding portion is provided on the top plate and the bottom plate, and this is inserted into the opening of the molding rubber mold to mold the molding rubber mold. The rubber mold holding portion is adhered and fixed to the inner peripheral surface of the molding rubber mold. In this case, it is necessary to precisely process both members so that the shapes of the molding rubber die holding part made of metal and the molding rubber die which is a rubber member are compatible with each other. Ideally, the top plate and the bottom plate and the molding rubber mold are integrally manufactured. However, in reality, it is difficult to manufacture them integrally.

Therefore, according to the present invention, the top plate and the bottom plate and the molding rubber mold are closely fixed to each other via the metal ring manufactured integrally with the molding rubber mold. That is, if the metal ring holding portion is provided on the molding rubber die and the metal ring is integrally manufactured, the metal ring and the metal ring holding portion can have complementary shapes, and both can be closely fixed. . Further, it is technically easy to provide complementary taper surfaces on both the molding rubber die holding portions provided on the top plate and the bottom plate and the metal ring, because both members are made of metal. It becomes possible to closely fix.

FIG. 4 shows an example of the above CIP molding apparatus. The basic structure of the device is similar to the example shown in FIG.
The difference is that the top plate 15 and the bottom plate 16 and the molding rubber mold 4 are closely fixed via a metal ring 26. The top plate 15 and the bottom plate 16 are closely fixed to the inner peripheral surface of the pressure vessel 2. The metal ring 26 is manufactured integrally with the molded rubber die 4, so that the metal ring 26 and the metal ring holding portion 27 of the molded rubber die 4 are closely fixed. Further, the metal ring 26 and the top plate 15 and the bottom plate 16 are tightly fixed to each other via tapered surfaces provided complementarily to each other.

In order to prevent the movement of the molding rubber die caused by the clearance between the molding rubber die and the pressure medium sealing rubber, as shown in FIG. 5, a convex portion on the outer peripheral surface of the molding rubber die 4 is formed. 25 is used in combination with the expansion means 19 to tightly fix both ends of the molding rubber mold 4 to the inner peripheral surface of the pressure medium seal rubber 5, or, as shown in FIG. 6, to the outer peripheral surface of the molding rubber mold 4. It is more effective to use the arrangement of the convex portion 25 and the metal ring 26 together.

[0026]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

Using the CIP molding apparatus shown in FIG. 5, a bottomed cylindrical molded body having an outer diameter of 47.0 mm, an inner diameter of 42.7 mm, and a height of 435 mm was produced, and the maximum uneven thickness and the rubber mold for molding were formed. The difficulty of putting on and taking off was observed. This molded body is used as a β-alumina tube for a sodium-sulfur battery.

A clearance 23 of 0.3 to 0.5 mm is provided between the molding rubber die 4 and the pressure medium sealing rubber 5. Further, the convex portion 25 provided on the outer peripheral surface of the molding rubber die 4 has a height of 10 mm.

The maximum eccentricity of the molded body when the conventional CIP molding apparatus was used was about 300 μm, whereas it was about 100 μm when the above CIP molding apparatus was used. Further, in the conventional CIP molding apparatus, a dedicated take-out jig and a press-fitting jig are required for attaching / detaching the molded rubber mold, and 15 to 20 minutes are required for each attachment / detachment. No special equipment was required and the time could be shortened within 5 minutes.

[0030]

According to the present invention, the CIP molding apparatus is provided with expansion means for expanding both ends of the molding rubber die from the inside and closely fixing to the inner peripheral surface of the pressure medium sealing rubber. Properly disposing one or more convex portions on the outer peripheral surface so that the molding rubber die and the pressure medium sealing rubber are in contact with each other only on the top surfaces of the convex portions, or the pressure vessel, the top plate and the bottom. By closely fixing the plate, the top plate and the bottom plate, and the molding rubber die, or by using them together, the movement of the molding rubber die caused by the clearance between the molding rubber die and the pressure medium seal rubber can be prevented. To prevent.
Therefore, it is possible to prevent uneven thickness of the molded body due to the existence of the clearance, and it is possible to provide a larger clearance between the molding rubber mold and the pressure medium seal rubber, so that the molding rubber mold can be attached and detached. It can be done more easily and efficiently.

[Brief description of the drawings]

FIG. 1 is a cross-sectional explanatory view showing an example of a CIP molding apparatus of the present invention.

2A and 2B are cross-sectional explanatory views showing a connecting portion between the expansion member and the molded rubber mold in the CIP molding apparatus of FIG. 1 before (a) insertion and (b) insertion.

FIG. 3 is an explanatory cross-sectional view showing another example of the CIP molding apparatus of the present invention.

FIG. 4 is a cross-sectional explanatory view showing still another example of the CIP molding apparatus of the present invention.

FIG. 5 is a cross sectional explanatory view showing still another example of the CIP molding apparatus of the present invention.

FIG. 6 is a cross sectional explanatory view showing still another example of the CIP molding apparatus of the present invention.

FIG. 7 is an explanatory sectional view showing a powder filling step of the CIP molding method.

FIG. 8 is a cross-sectional explanatory view showing a pressing step of the CIP molding method.

FIG. 9 is a cross-sectional explanatory view showing a pressure reducing step of the CIP molding method.

FIG. 10 is an explanatory cross-sectional view showing a molded body taking-out step of the CIP molding method.

[Explanation of symbols]

1 ... powder feeding nozzle, 2 ... pressure vessel, 3 ... mandrel,
4 ... molding rubber mold, 5 ... pressure medium sealing rubber, 6 ... pressure medium inlet / outlet, 7 ... seal rubber holder, 8 ... molding space, 9
... Bottom punch, 10 ... Top rubber plug, 11 ... Top punch, 12 ... Molded body, 13 ... Bottom ram, 14 ...
CIP molding device, 15 ... top plate, 16 ... bottom plate, 17 ... hole in top plate, 18 ...
Bottom plate hole, 19 ... Rubber mold holding part for molding,
20 ... Diameter of insertion end of molding rubber die holding portion, 21 ... Inner diameter of molding rubber die opening end portion, 22 ... Maximum diameter of molding rubber die holding portion, 23 ... Clearance, 24 ... pressure vessel lid, 25 ... convex portion, 26 ... metal ring, 27 ... metal ring holding portion.

Claims (8)

[Claims] 1. A pressure medium seal rubber, a molding rubber mold installed inside the pressure medium seal rubber with a certain clearance from the inner peripheral surface thereof, and a columnar shape arranged inside the molding rubber mold. And a mandrel of which the outer peripheral surface is formed by the molding rubber mold and the inner peripheral surface of which is formed by the mandrel is filled with raw material powder into a cylindrical or bottomed cylindrical molding space. A dry hydrostatic pressure molding apparatus for molding a cylindrical body or a bottomed cylindrical body by applying hydrostatic pressure from the outer peripheral side, wherein both ends of the molding rubber die are expanded from the inside, A dry hydrostatic pressure molding apparatus comprising expansion means for closely fixing the outer peripheral surfaces of the both end portions to the inner peripheral surface of the pressure medium sealing rubber. 2. The expanding means is a top plate and a bottom plate that sandwich the molding rubber die from above and below, and the top plate and the bottom plate are inserted into the openings of the molding rubber die. It is fixed to the molding rubber mold through a holding part, and the molding rubber mold holding part has a maximum diameter equal to or larger than the size obtained by adding the clearance to the inner diameter of the opening of the molding rubber mold. 2. The dry hydrostatic pressure molding apparatus according to claim 1, wherein the dry hydrostatic pressure molding apparatus has a tapered portion, and the diameter of the insertion end is equal to or less than the inner diameter of the opening of the molding rubber die. 3. A pressure medium seal rubber, a molding rubber mold installed inside the pressure medium seal rubber, and a columnar mandrel arranged inside the molding rubber mold. After the outer peripheral surface is filled with raw material powder in a cylindrical or bottomed cylindrical molding space whose inner peripheral surface is formed by the mandrel, hydrostatic pressure is applied by a pressure medium from the outer peripheral side of the molding rubber mold. It is a dry hydrostatic pressure molding apparatus for molding a cylindrical body or a bottomed cylindrical body by means of which the rubber mold for molding has a peripheral surface of 0.2 to 2.0 mm.
And one or more protrusions having a height of, the molding rubber mold is in contact with the pressure medium seal rubber only at the top surface of the protrusion at normal pressure, and the protrusion is The molding rubber die is appropriately arranged so as to be fixed at a fixed position in the pressure medium sealing rubber, and the total area of the top surface is 2 to 10% of the outer peripheral area of the molding rubber die. Characteristic dry hydrostatic pressure molding equipment. 4. The dry hydrostatic pressure molding apparatus according to claim 3, wherein at least the outer peripheral surface of the upper end portion and the outer peripheral surface of the lower end portion of the molding rubber die have the convex portion over the entire circumference. 5. A pressure medium seal rubber, a molding rubber mold installed inside the pressure medium seal rubber with a certain clearance from the inner peripheral surface thereof, and a columnar shape arranged inside the molding rubber mold. Of the mandrel and a pressure container for accommodating the mandrel, and the raw material powder was filled into a cylindrical or bottomed cylindrical molding space having an outer peripheral surface formed by the molding rubber mold and an inner peripheral surface formed by the mandrel. After that, a dry hydrostatic pressure molding apparatus for molding a cylindrical body or a bottomed cylindrical body by applying hydrostatic pressure with a pressure medium from the outer peripheral side of the molding rubber die, further comprising: A top plate and a bottom plate that have an outer peripheral surface that fits the inner peripheral surface and that sandwich the molding rubber die from above and below while the outer peripheral surface and the inner peripheral surface are in close contact are provided. The muffle plate has a taper-shaped molding rubber mold holding part inserted into the opening of the molding rubber mold, and the molding rubber mold has a tapered surface complementary to the molding rubber mold holding part. The metal ring is held by the top plate and the bottom plate via a metal ring, and the metal ring is provided on the upper inner peripheral surface and the lower inner peripheral surface of the molding rubber mold and has a shape complementary to the metal ring. A dry hydrostatic pressure molding apparatus, which is installed in the molding rubber mold in a state of being in close contact with a ring holding portion. 6. A top plate and a bottom plate having an outer peripheral surface adapted to the inner peripheral surface of the pressure vessel, and sandwiching the molding rubber die from above and below in a state where the outer peripheral surface and the inner peripheral surface are in close contact with each other. The top plate and the bottom plate each have a taper-shaped molding rubber die holding part inserted into the opening of the molding rubber die, and the molding rubber die is the molding rubber die holding part. Is held on the top plate and the bottom plate via a metal ring having a tapered surface complementary to the metal ring, the metal ring being provided on the upper inner peripheral surface and the lower inner peripheral surface of the molding rubber mold. The dry hydrostatic pressure molding apparatus according to claim 3 or 4, which is installed in the molding rubber mold in a state of being in close contact with a metal ring holding portion having a complementary shape. 7. A top plate and a bottom plate for holding the molding rubber mold from above and below, wherein the top plate and the bottom plate have a molding rubber mold holding portion inserted into an opening of the molding rubber mold. Is fixed to the molding rubber die through the molding rubber die holding portion, and the molding rubber die holding portion has a taper portion having a maximum diameter equal to or larger than the inner diameter of the opening of the molding rubber die, and the diameter of the insertion end. Is equal to or less than the inner diameter of the opening of the molding rubber mold, the molding rubber mold holding portion expands both ends of the molding rubber mold from the inside, and the outer peripheral surfaces of the both ends are the pressure medium seal rubber. The dry isostatic pressing apparatus according to claim 3 or 4, which is closely fixed to the inner peripheral surface of the. 8. A dry hydrostatic pressure molding method, wherein a cylindrical body or a bottomed cylinder body is molded by using the dry hydrostatic pressure molding apparatus according to claim 1.