JPH0343956B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high-pressure container for a cold isostatic press apparatus for compression molding powder.

Hydrostatic pressurization equipment that compresses and molds high-pressure processed raw materials using a pressure medium uses either a screw type or a press frame type, but the former has problems with the fatigue strength of the threaded part, and the screw cap In recent years, when attaching and detaching operations are complicated and high productivity is required, press frame-type hydrostatic pressurization devices have been used with ultra-high molding pressures in recent years. In order to maintain such ultra-high pressure, the high-pressure vessel needs to increase its wall thickness (i.e. /inner diameter ratio), but when the internal pressure is high, even if the outer-inner diameter ratio is 3 to 4 or more, the high-pressure vessel It is less effective in reducing the stress generated on the internal surface, and this high stress results in a limited useful life of the high pressure vessel. Conventionally, as a countermeasure to this problem, methods such as shrink fitting have been used to impart compressive residual stress to the inner surface of the high-pressure container, but there are limits to their effectiveness at ultra-high pressures.

To deal with this, a pressure intensifying vessel is arranged inside the high pressure vessel main body, and the pressure receiving area on the high pressure vessel main body side is larger than the pressure receiving area on the pressure intensifying vessel side through a hole opened in the high pressure vessel main body provided in the same pressure intensifying vessel. The pressure intensifier piston is inserted into the larger pressure intensifier piston so as to be able to move in the axial direction, and the pressure intensifier piston is moved toward the pressure intensifier vessel under a load by the pressure medium in the high pressure vessel main body, and the pressure intensifier piston is moved toward the pressure intensifier vessel. A device that can obtain even higher pressure has been proposed.

However, this kind of equipment has the disadvantage that a relatively large amount of water (pushing stroke of the pressure intensifying piston to increase the pressure) is required to increase the pressure inside the pressure intensifying container, and therefore the effective volume that can accommodate the object to be processed cannot be made large. It was hot.

In view of the above-mentioned problems, the present invention aims to shorten the pushing stroke of the pressure booster piston and increase the effective volume of the pressure booster container.

Embodiments according to the present invention will be described below based on the drawings. FIG. 1 is a longitudinal cross-sectional view of a high-pressure container, and FIG. 2 is a process diagram of cold isostatic pressurization using this high-pressure container. In the figure, A is the high-pressure container main body into which the present pressure intensifier container is placed, B is the upper lid of the high-pressure container main body A, and the lid is provided with a water supply and drainage port C. Reference numeral 1 denotes a pressure intensifier container, and 3 a pressure intensifier container cover, which are integrated into one body by screw fastening. Further, the pressure intensifier container cover 3 is attached to the high pressure container upper lid B by a pressure intensifier container mounting fitting D, and the pressure intensifier container is structured to be suspended from the upper lid. Reference numeral 6 denotes a pressure boosting piston guide, which is attached to the lower part of the water supply/drainage port C of the upper cover B as one unit by fastening screws. Reference numeral 2 denotes a pressure booster piston, which slides along the pressure booster container cover 3 and pressure booster piston guide 6, is airtightly fitted into the pressure booster container 1 with a gasket 10, and moves downward under pressure on its upper surface. . 21
is a gas phase portion, and is designed not to become a resistance to the movement of the pressure boosting piston 2.

11, 12, 13, 14 and 15 are packkins. The pressure booster piston guide 6 has a water supply and drainage port 6a.
is provided, and a check valve 7 is incorporated in the lower part. Reference numeral 5 denotes a valve push rod whose tip end is inserted into the check valve from the upper part through the water supply and drainage port 6a, and when 5 is pushed down, the check valve 7 is opened. Therefore, the compression properties of high-pressure treated raw materials (powder of ceramics, cemented carbide, etc.) to be compression molded have a large compressibility in the low pressure range, and molding can be achieved by directly introducing pressurized water into the pressure intensifier vessel 1 at low pressure. The body contracts greatly, and since the amount of contraction during pressurization of the pressure increase piston 2 during the pressure increase process is small, the pushing stroke of the pressure increase piston 2 can be shortened. 2
A is a drainage passage, and 2b is a water supply passage, and a check valve 8 and a pressure regulating valve 9 are installed in the pressure increasing piston 2 and interposed in each passage. The pressure regulating valve 9 is set below the maximum pressure of high pressure water.
In addition, pressurized water is supplied from the water supply/drainage port C, and reaches the water supply channel 2b through the intermediate opening of the pressure booster piston guide 6 having the check valve 7, through the water channel provided on the outer circumference of the guide and the inner circumference of the pressure booster piston 2. , the pressure regulating valve 9 provided in the pressure booster piston 2 is opened and pressure is applied to the top surface of the pressure booster piston 2 between the lower surface of the upper cover B and the top surface of the pressure booster piston 2 to push down the pressure booster piston 2 and simultaneously increase the pressure. A water channel is formed between the inner periphery of the container mounting bracket D and the outer periphery of the pressure booster piston 2, and the pressurized water coming out from the water channel formed between the outer periphery of the pressure booster container cover 3 and the inner periphery of the lower part of the pressure booster container mounting bracket D is under high pressure. A passage communicating with the inside of the container A is flushed with water. Reference numeral 4 denotes a raw material receiving seat, which has a lattice structure and is attached to the pressure intensifying vessel 1 in a structure that allows it to be easily attached and detached. 16 is the pressure booster vessel receiver and high pressure vessel A
It is attached to the bottom of the pressurizing container 1 with bolts 20, and the bottom of the pressure increasing container 1 is airtightly sealed by a packing 18. 17 and 19 are also Patsukin.

E is a drain hole provided in the lower lid of the high-pressure container A, and a high-pressure gate valve (not shown) is attached to the outside. When the pressure is increased, this part is subjected to the same high pressure as inside the pressure intensifier container 1, so if a pressure sensor is attached to the outside of the drain, the pressure inside the pressure intensifier container 1 can be detected.

The operation of the high-pressure container having the above structure will be explained based on the cold isostatic pressurization process (FIG. 2) using this high-pressure container.

(a) The pressure booster container 1 is suspended below the upper lid B of the high pressure container A, and is positioned above the upper lid B by the loading/unloading device L. A water supply and drainage shaft (not shown) is inserted into the water supply and drainage port C, and the valve push rod 5 is pushed downward to open the check valve 7. Further, the high-pressure treated raw material H is placed on a raw material receiving seat 4 and set on a receiving stand G.

(b) Lower the pressure booster vessel 1 and attach the catch seat 4.
(Insertion of raw materials) (c) Lift the pressurized container 1 upward together with the raw material H inside.

(d) Move high pressure vessel A below pressure intensifier vessel 1. There is an arbitrary amount of water in the high pressure vessel A.

(e) Insert pressure vessel 1 into high pressure vessel A. Due to this injection, the water level in the high pressure container A rises, and if there is a shortage, the water supply and drainage shaft (not shown) → Water supply and drainage port C
Water is supplied through the high-pressure container A, and overflows from the overflow port K at the top of the high-pressure container A, so that there is a sufficient amount of water in the container. Also, since the bottom of the pressure booster container 1 is open, water can flow into it.
At the same time, air is vented from the check valve 7 opened by the valve push rod 5 through the water supply and drainage ports 6a and C.

(f) Further lower the pressure intensifier container 1 and fit the bottom part into the pressure intensifier container seat 16 for sealing. At the same time, the upper lid B is fitted onto the upper part of the high pressure container A in an airtight manner. At this time, the air and excess water in the high-pressure container A are removed from the upper lid B.
Due to the lowering of the water, the water is discharged to the outside through the check valve 8 → drain passage 2a → drain port 6a → drain port C. In this way, at the same time as the lid is fitted, the pressurized container 1
Then, the high-pressure container A is filled with water and air is removed.

(g) Separate the upper cover B and the loading/unloading device L. At this time, the water supply and drainage shaft (not shown) is pulled out from the water supply and drainage port C, and the spring inside the check valve 7 causes the valve body and the valve push rod to rise upward, and the valve 7 is closed.
Next, move the high-pressure container A into the press frame, and connect the pressurized water injection shaft (not shown) to the water supply and drainage port C.
Insert it and send high-pressure water to apply pressure.

At this time, the injection shaft is inserted to a depth that does not hit the valve pusher rod 5, so that the check valve 7 does not open.

(h) At the primary pressure (below the set pressure of the pressure regulating valve 9), pressurized water is pumped into the pressure booster vessel 1 by the pressure regulating valve 9.
It is fed only into the interior and performs compression molding of the raw material H. When the pressure further increases, the pressure regulating valve 9 opens, and high pressure water flows into the high pressure container A.
Pressurized. Due to the balance of pressure inside and outside the pressure intensifier container 1, the pressure intensifier piston 2 receives pressure on the upper surface and is pushed into the pressure intensifier container 1, and the pressure in the pressure intensifier container 1 is increased according to the pressure receiving area ratio of the pressure intensifier piston 2. Ru.
At this time, the pressure inside the pressure intensifying container 1 is maintained because the check valve 7 is closed.

(i) When compression molding is completed, pressurized water flows through check valve 8→
Water is drained through the drain passage 2a → water supply/drainage port 6a → water supply/drainage port C, and the pressure inside the high-pressure container A is lowered to the receiving pressure. At this time, the pressure intensifier piston 2 is pushed upward by the pressure inside the pressure intensifier container 1, and
The pressure inside is lowered to the set pressure (primary pressure) of the pressure regulating valve 9.

(j) Further, the pressure in the pressure intensifying container 1 is lowered to normal pressure by inserting the pressurized water injection shaft deeper and pushing down the valve push rod to open the check valve 7. Of course, the pressure can also be lowered by opening the drain hole E.

The processed raw material is taken out in the reverse order (g) → (f) → (e) → (d) → (c) → (b) → (a).

As explained above, according to the present invention, the raw material is compressed by feeding pressurized water only into the pressure intensifying container up to the primary pressure (below the maximum pressure of pressurized water), so the amount of water required is small, and the pressure is increased only by the pressure intensifying piston. The required stroke of the piston is significantly smaller than that in the case where the pressure increaser is used, and the effective volume of the pressurized container is increased.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment according to the present invention;
FIG. 2 is a process diagram of cold isostatic pressurization according to the embodiment shown in FIG. 1... Pressure booster container, 2... Pressure booster piston, 4...
Raw material catch, 6... Pressure booster piston guide, 6a...
Water supply and drainage port, 7...Check valve, 9...Pressure adjustment valve.

Claims (1)

[Claims] 1. In a high-pressure container of a cold isostatic pressurizing apparatus, the object to be processed is compressed and molded by a pressure medium into a high-pressure container main body, which is formed by attaching upper and lower lids to the upper and lower openings of a high-pressure cylinder. A cylindrical pressure intensifying vessel that can be inserted into the high pressure vessel main body and is suspended from the upper lid, and the upper opening of the pressure intensifying vessel has a pressure receiving area on the high pressure vessel main body side that is larger than the pressure receiving area on the pressure intensifying vessel side. A pressure intensifier piston, which is larger than the above, is inserted so as to be movable in the axial direction, and a fluid injection path is provided in the pressure intensifier container, and a passage is provided to communicate between the inside of the pressure intensifier container and the high pressure container main body, and a predetermined A high-pressure container characterized by interposing a pressure regulating valve set to the pressure.