JPH0335598B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hot isostatic press apparatus that stores a workpiece in a heating furnace inside a high-pressure container and processes the workpiece under high temperature and high pressure.

The hot isostatic press equipment (HIP equipment) stores the product to be processed in a heating furnace built into a high-pressure container, and heats an inert gas such as argon gas sealed inside at high temperature and high pressure. The heating furnace has a space surrounded by a heat insulating layer, that is, a furnace chamber. In order to improve the thermal efficiency inside the furnace, the insulation layer is made of a material with particularly excellent heat resistance and insulation performance, and the temperature inside the furnace is reduced.
It is now possible to raise the temperature to about 2,000℃ and 2,000atm, and after hot isostatic pressing, the processed product must be cooled to about 100 to 150℃ in the furnace before being taken out. It takes a long time to cool down the inside of the furnace, which is surrounded and defined by a heat insulating layer.
Therefore, conventionally, a cooling means for forcibly circulating a refrigerant within the furnace has been employed in order to actively lower the temperature inside the furnace.

However, in the conventional cooling by forced circulation, it is difficult to flow the refrigerant into every corner of the triple structure consisting of a high-pressure container, a heat insulating layer, and a heating mechanism, and a satisfactory cooling effect cannot be obtained.
Further, it requires a complicated forced circulation device, which increases the size of the entire device.

The present invention was developed in order to eliminate the above-mentioned drawbacks of the heating furnace of a conventional hot isostatic press apparatus, and is a hot isostatic press equipped with a heating furnace with a built-in heating mechanism inside a high-pressure container. In a hydraulic press device, an air inlet passage having an intake check valve is provided on the lower side of the heating furnace defined by a heat insulating layer, and air is passed from the exhaust check valve in the upper part of the furnace through a flow path in the heat insulating layer. The cooling mechanism is equipped with a furnace gas discharge path that reaches a flow path outside the heat insulating layer via a discharge check valve on the lower end side, and the check ball of the exhaust check valve is operated by a valve push rod supported by an elastic heat insulating layer. The hot isostatic press is characterized by the fact that it is energized, and its purpose is to efficiently cool the heating furnace inside the high-pressure container by incorporating a simple cooling mechanism into the heating furnace. The point is that the device provides a heating furnace.

The present invention has the above-mentioned structure, and when the pressure inside the flow path outside the heat insulation layer is reduced upon completion of the hot isostatic pressing process, the reduced pressure opens the exhaust check valve and reaches the flow path inside the heat insulation layer, and is then used for exhaust. As the check valve is opened and the gas reaches the furnace chamber, the high-temperature, high-pressure gas in the furnace chamber is cooled and discharged through the flow path inside the insulation layer and the flow path outside the insulation layer. As the inside of the flow path outside the heat insulating layer is cooled, the intake check valve opens due to the relative negative pressure inside the furnace chamber, and the gas inside the furnace is replaced by the low-temperature gas flowing in from the intake air path, and the above-mentioned pressure reduction and pressurization are performed. By repeatedly injecting low-temperature gas, the entire interior of the high-pressure vessel, including the inside of the furnace chamber, can be efficiently cooled in a short period of time, and the hot isostatic press processing capacity can be significantly improved by shortening the cycle time.

Furthermore, in the present invention, the check ball of the exhaust check valve through which the high-temperature, high-pressure furnace gas directly flows is biased by the valve pusher rod supported by the elastic heat insulating layer. The check valve has a heat-resistant structure and is durable and reliable in operation, and since the gas inside the furnace is cooled as it flows through the flow path inside the insulation layer and the flow path outside the insulation layer, it is possible to prevent the intake and exhaust of the high-pressure vessel. The durability of the ports, connected intake/exhaust pipes, start valves, etc. can be minimized and their durability can be increased, and the time required for filling inert gas for processing can be reduced by the low-temperature gas sealed in the flow path within the heat insulating layer. It has advantages such as shortening of the heating time and miniaturization of the device by compactly incorporating a cooling mechanism with a simple structure into the heating furnace.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. An embodiment of the present invention is shown in FIGS. 1 to 4, in which 1 is a high-pressure container main body, 2 is a seal ring 2, and 2 is a seal ring 2.
3 is a bottom lid having a seal ring 3a, and at least the top lid 3 is connected to the high pressure container main body 1.
Can be attached and detached (can be done by screwing, etc.)
A bottom cover 3 and a top cover 2 are closely attached to the top and bottom of the high-pressure vessel main body 1 as shown in the figure to form a closed high-pressure vessel with a structure that can withstand high temperatures and high pressures.

Further, on the upper side of the bottom lid 2, upper and lower members 4a,
A hearth 5 made of a heat insulating material is disposed via a support member 4 having a support member 4b.
A cylindrical heat insulating layer 10 having an upper surface is placed at an appropriate distance around the periphery of the high-pressure vessel. Furnace chamber A surrounded and defined
A hermetically sealed heating furnace with , and has a structure in which hot isostatic pressing can be applied to the housed workpieces (not shown) under high pressure.

Furthermore, the heat insulating layer 10 includes an inner heat insulating layer 10
a. Consisting of an outer heat insulating layer 10b and an exterior plate 11, a flow path B within the heat insulating layer extending from the top surface to the lower side is provided between the inner heat insulating layer 10a and the outer heat insulating layer 10b, and the inner and outer heat insulating layers A cover ring 13 inserted into the protruding lower end 11a of the exterior plate 11 is disposed on the downstream side of the exterior plates 10a and 10b, and the lower end 11a of the exterior plate 11 is removably fitted into the support member 4. The heat insulating layer 10 has hanging tools 14,
It is suspended by the upper lid 3 via the upper lid 3 and can be stored in and taken out from the high-pressure container together with the upper lid 3.

Furthermore, on the lower side of the heating furnace, there is an inlet check valve 15 that is attached to the lower member 4b of the support member 4 and that allows air to flow only to the furnace chamber A side, and an upper member 4 of the heating furnace.
an air inlet passage consisting of an air inlet hole 16 extending through the hearth 5, and an inner heat insulating layer 10 at the upper part of the furnace.
A is provided with an exhaust check valve 17 that communicates with the flow path B in the heat insulating layer and allows flow only to the flow path side.
A cooling spiral channel 13a is provided which communicates with the lower end of the spiral channel 13a.
A cooling pipe 18 with fins is disposed in the cooling chamber D between the space D and reaches the lower end 11a of the exterior plate 11.
A discharge check valve 19 is provided which can flow only to the side of the flow path C outside the heat insulating layer between the high pressure container main body 1 and the high pressure container body 1,
A cooling flow path consisting of an exhaust check valve 17, a heat insulating layer inner flow path B, a spiral flow path 13a, and a cooling pipe 18;
The exhaust check valve 19 and the flow path C outside the heat insulating layer constitute a furnace gas exhaust path.

Further, an intake/exhaust port 20 is provided in the upper part of the high-pressure container, that is, the upper lid 3, and an intake/exhaust pipe 21 having an on-off valve 22 is connected to the intake/exhaust port 20. The entrance space E between the bottom cover 2 and the lower member 4b is communicated with the lower part of the flow path C outside the heat insulating layer through an opening (not shown) provided in the lower end 11a of the exterior plate 11. The low temperature gas flowing from the side space E through the intake check valve 15 passes through the cooling chamber D in the support member 4 and flows into the furnace chamber A through the intake hole 16.

Furthermore, FIGS. 2 and 3 show other embodiments of the flow path within the heat insulation layer, and the flow path B ₁ within the heat insulation layer is the same flow path.
A heat insulating layer plate 30 made of graphite having excellent heat resistance and elasticity is provided on the outside of B ₁ , that is, on the inner side of the outer heat insulating layer 10b, and a heat insulating layer plate 30 on the upper side is provided.
A cover plate 32 having a spiral groove 31 on the lower side of the
is buried, and the furnace gas that has passed through the exhaust check valve 17 passes through the spiral groove 31 of the cover plate 32 and flows into the flow path on the side.

Furthermore, the exhaust check valve 17 shown in FIGS. 1 and 2 has the following features, especially as shown in FIG.
Bush 35 having an exhaust hole in the inner heat insulating layer 10a
At the same time as inserting the valve seat 3 in the bush 35.
Insert the check ball 36 into 5a so that it can move up and down,
A valve push rod 37 made of graphite and having a cross-shaped cross section is interposed between the check ball 36 and the heat insulating laminate 30, and the valve push rod 37 is supported by the bendable heat insulating laminate 30 on the upper side, and is connected to the check ball. 36 is urged toward the valve seat 35a side, and the valve pusher rod 37 is forced through the check ball 36 by the high pressure of the furnace gas in the furnace chamber A to check the flexibility of the heat insulating laminate 30 and its upper surface side. It is moved to the same side by the elasticity of the outer heat insulating layer 10b, so that the furnace gas can flow and flow into the spiral groove 31.

Note that 38 in FIG. 1 is a sealing member between the lower end of the inner heat insulating layer 10a and the lower end 11a of the exterior plate 11 and the cover ring 13. The illustrated embodiment has the above-mentioned configuration, so that when the upper cover 3 is removed from the high-pressure vessel body 1 and raised together with the heat insulating layer 10, the furnace chamber A in the high-pressure vessel body 1 can be opened.
The products to be processed are placed on the hearth 5 and accommodated. Then, as shown in the figure, a heat insulating layer 10 is placed inside the high-pressure vessel main body 1, an upper lid 3 is fitted, and an appropriate mechanism (not shown) is used to supply a processing inert gas such as argon gas to the inside and outside of the heating furnace inside the high-pressure vessel. By pressurizing and enclosing gas and raising the inert gas in the furnace chamber A to high temperature and high pressure by the heater 6, the workpiece (not shown) on the hearth 5 is subjected to hot isostatic pressing treatment, that is, by Molding processing such as powder sintering can be performed.

If the item to be processed is taken out immediately after the processing is finished, extremely high-temperature and high-pressure furnace gas will blow out, making it difficult and dangerous to handle the high-temperature item. Container must be opened. In the embodiment described above, when the hot isostatic pressing process is completed, the on-off valve 22 is opened to exhaust the inside of the flow path C outside the heat insulating layer to reduce the pressure, and the reduced pressure opens the exhaust check valve 19 to open the cooling pipe 18 and the spiral stream. The passage 13a reaches the insulating layer passage B (or B ₁ ), and the exhaust check valve 17 is opened, and the high temperature and high pressure furnace gas in the furnace chamber A is discharged from the exhaust check valve 17. It flows through the passage and is discharged from the passage C outside the heat insulating layer to the intake/exhaust port 20 and the intake/exhaust pipe 21.

Inside the high-pressure container after hot isostatic pressing, the temperature inside the furnace chamber A is the highest, and the inside of the heat insulating layer flow path B or B ₁ , the spiral flow path 13a, the cooling pipe 18, and the flow path outside the heat insulating layer C Since the temperature in the furnace chamber A is relatively low,
The high-temperature, high-pressure in-furnace gas is cooled while flowing through these channels, and then discharged from the intake and exhaust ports 20 of the high-pressure container, and is discharged through the discharge check valve 19, the intake and exhaust ports 20, the intake and exhaust pipes 21, and the on-off valves. 22 etc. is significantly reduced and durability is increased. Furthermore, in this embodiment, there is an exhaust check valve 17 through which the high-temperature, high-pressure furnace gas in the furnace chamber A directly flows.
consists of a check ball 36 seated on the valve seat 35a of the bush 35, and a cross-shaped valve push rod 37 made of graphite supported by the heat insulation layer plate 30 on the side of the outer heat insulation layer 10b. Since the ball 36 is biased against the valve seat 35a, when high pressure on the furnace chamber A side is applied to the check ball 36, the check ball is pushed through the valve push rod 37 due to the flexibility of the heat insulating layer plate 30 and the elasticity of the outer heat insulating layer. 36 moves upward in the figure, allowing the gas in the furnace to flow. In this embodiment, the valve push rod 37 has excellent heat resistance, has extremely little heat damage, and has a cross-shaped cross section that allows the gas in the furnace to flow. Sufficient circulation space is secured, durability,
This is a reliable exhaust check valve.

In addition, the spiral groove 31 in the flow path B ₁ in the heat insulation layer
This lengthens the flow path of the furnace gas that has passed through the exhaust check valve 17, which has the effect of enhancing the cooling effect and reducing subsequent thermal damage to the flow path.

Next, after the pressure reduction, the intake/exhaust pipe 21, the intake/exhaust port 2
Low temperature gas is pressurized from 0 into the flow path C outside the heat insulating layer and pressurized. The low-temperature gas cools the flow path C outside the heat insulating layer and also flows into the air intake space E of the air intake check valve 15.
The air flows into the cooling chamber D through the inlet check valve 15, which is opened in connection with the depressurization of the furnace chamber A, and cools the cooling pipe 18 and the cover ring 13. It flows into chamber A and is replaced with the furnace gas.

By repeating depressurization and pressurization on the side of the flow path C outside the heat insulating layer, it is possible to efficiently cool and depressurize the entire area inside the high-pressure container including the inside of the heating furnace. When the above-mentioned depressurization and pressurization (injection of low-temperature gas) are repeated, the pressure characteristics P and temperature characteristics T as shown in Fig. 5 are obtained, and the temperature drop progresses smoothly, cooling can be performed efficiently, and the pressure is depressurized at the same time. .

After the cooling is completed _, the product to be processed is newly stored and filled with a processing inert gas for generating high-temperature, high-pressure gas. As a result, the time required for encapsulation is shortened, the time required for cooling is shortened, and the cycle time is shortened, thereby significantly improving processing capacity.

Further, the cooling mechanism in this embodiment has a simple structure and is compactly incorporated into the heating furnace, resulting in a compact device with improved durability and reliability.

Although the present invention has been described above with reference to embodiments, it goes without saying that the present invention is not limited to such embodiments, and that various design changes can be made without departing from the spirit of the present invention. .

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view of a hot isostatic press apparatus showing one embodiment of the present invention, FIG. 2 is an enlarged sectional view of another embodiment of the flow path in the heat insulating layer and the exhaust check valve shown in FIG. Fig. 3 is a plan view of the cover plate shown in Fig. 2; Fig. 4 is an enlarged sectional view of the exhaust check valve portion shown in Figs. 1 and 2; and Fig. 5 is a characteristic diagram of temperature and pressure in the present invention. . 1: High pressure container body, 2: Bottom lid, 3: Top lid, 5:
hearth, 6: heating mechanism (heater), 10: heat insulation layer,
15: Air intake check valve, 16: Air intake hole, 1
7: Exhaust check valve, 19: Discharge check valve, 20: Intake/exhaust port, A: Furnace chamber, B,
B ₁ : Channel inside the heat insulating layer, C: Channel outside the heat insulating layer, E: Inlet space.

Claims (1)

[Claims] 1. In a hot isostatic press device equipped with a heating furnace with a built-in heating mechanism in a high-pressure container, an air intake path having an air intake check valve is provided on the lower side of the heating furnace defined by a heat insulating layer. , a cooling mechanism provided with an in-furnace gas discharge passage from an exhaust check valve in the upper part of the furnace, through a passage in the insulation layer, to a passage outside the insulation layer via a discharge check valve on the lower end side; A heating furnace for a hot isostatic press device characterized by a configuration in which a check ball of a valve is biased by a valve push rod supported by an elastic heat insulating layer.