JPH0548077Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The invention is a method of processing non-oxide ceramic products, etc. in a pressure vessel maintained at a temperature of around 2000°C in a gas pressurized atmosphere. Hot isostatic pressing equipment (hereinafter referred to as HIP equipment) for obtaining strong parts
Regarding.

(Prior Art) Conventionally, as shown in FIG. 6, the HIP device 1 is a pressure vessel in which the upper and lower openings in the axial direction are removably closed with a lower lid consisting of an upper lid 2, a lower inner lid 3, and a lower outer lid 4. 5
, a heat insulating layer 7 for insulating heat between the inner wall 5A of the pressure vessel 5 and the processing chamber 6, a processing material mounting table 8 mounted on the lower inner lid 3, and a space between the heat insulating layer 7 and the table 8. It is mainly composed of a heater 9 and a heater support tube 10 arranged in the heater 9 and the heater support tube 10 . The heater 9 is
In order to obtain heat uniformity in the vertical direction, heater elements 9A, 9B, 9 are divided into several stages in the vertical direction.
As shown in FIGS. 7 and 8, C and 9D are attached to the support tube 10 in a suspended manner with pins 12 through insulators 11. The heater support tube 10 is fixed on the lower outer cover 4 via a support column 13, and some ultra-large HIP devices have a diameter of 1 m or more and a height of several meters. 14 is an electrode, 1
5 is a gas supply hole.

The heater support cylinder 10 includes (a) a heater support cylinder 10;
(b) Heater elements 9A to 9D, insulator 1
Three forces are mainly applied: (1) the weight of the pin 12, etc., and (c) thermal stress. The vertical stress due to these forces (a) to (c) increases linearly as the stress due to the above (a) and (b) goes lower, and the stress due to (c) increases linearly in the soaking area of the processing chamber 6. In this case, the temperature is almost zero, but it becomes considerably large in the area where the temperature gradient is large downward from the upper surface 8A of the processing object mounting table 8.

(Problem to be solved by the invention) By the way, in the conventional HIP apparatus, as mentioned above, the stress acting on the heater support cylinder 10 is extremely large in the region below the upper surface of the processing object mounting table 8 than in the upper part. Although the influence of thermal stress is particularly large, since the lower part of the heater support cylinder 10 is fixed on the support column 13, thermal expansion in the radial direction of the lower part of the heater support cylinder 10 is restricted, so the heater support There are problems with the strength of the tube 10, such as deformation.

The present invention was developed in view of the above-mentioned circumstances, and its purpose is to reduce thermal stress caused by an increase in temperature gradient by reducing thermal stress or improving strength. To provide a HIP device that prevents a support tube from being deformed.

(Means for Solving the Problems) The present invention includes a pressure vessel, an upper cover and a lower cover that removably close upper and lower openings in the axial direction of the pressure vessel;
A hot oven having a processing material mounting table placed on the lower lid, a heater disposed around the processing material mounting table, and a heater support cylinder provided on the lower lid and supporting the heater. In the isostatic pressing apparatus, the following technical measures are taken to achieve the above-mentioned objective.

That is, in the present invention according to claim 1, the heater support cylinder is placed on a heater support cylinder mounting table provided on the lower lid so as to allow thermal expansion in the radial direction of the pressure vessel. It is characterized by this.

Furthermore, the present invention according to claim 2 is characterized in that a thick portion is provided in a portion of the lower portion of the heater support cylinder where the temperature gradient is large.

(Function) When performing HIP processing on the processing object placed on the processing object mounting table, the heater support tube tends to thermally expand in the radial direction.

Since the heater support cylinder is not fixed to the mounting table but is divided and mounted to allow for thermal expansion in the radial direction, there is no restriction on the thermal expansion.
Thermal stress is significantly reduced to prevent deformation of the heater support cylinder.

Furthermore, during HIP processing, the temperature gradient is larger below the processing object mounting table than above, and the stress value at the lower part of the heater support cylinder tends to increase accordingly.

Therefore, since bending stress is generally inversely proportional to the square of the wall thickness, by providing a thick wall portion at the lower part of the heater support cylinder where the temperature gradient is large, the generated stress is reduced and deformation is prevented.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

FIG. 1 shows a first embodiment of the present invention, and since the configuration of the HIP device 1 is the same as that shown in FIG. 6 described as a conventional example, the same symbols and names as in FIG. The explanation will be omitted and the heater support tube 10 will be explained in detail.

In FIG. 1, the heater support cylinder 10 has the same thickness from the top to the bottom, and is placed on an annular step 16A recessed in the upper surface of a ring-shaped support cylinder mounting base 16 fixed on a support column 13 so as not to tip over.

That is, the heater support tube 10 is not fixed but placed on the heater support tube mounting table 16 provided on the lower lid so as to allow thermal expansion in the radial direction.

Therefore, the expansion and contraction of the heater support cylinder 10 due to thermal expansion can be freely carried out because the heater support cylinder 10 is freed from restraint by the struts 13 and the table 16, and the generated thermal stress is reduced compared to that of the prior art. This is significantly reduced to one-third or less, and deformation of the heater support cylinder 10 is prevented.

Therefore, we used a HIP device 1 equipped with a processing chamber 6 with a diameter of 700 mm and a height of 1900 mm.
A comparative experiment between the first embodiment and the prior art shown in FIG. 6 under the condition of Kgf/cm ² revealed that the heater support cylinder 1
However, in the first embodiment, the heater support tube 10 did not deform and the operation could be continued even after more than 100 cycles of operation.

FIG. 2 shows the main part of the second embodiment of the present invention,
A flange portion 10A is formed at the lower end of the heater support tube 10, a fitting step portion 10B is provided on the inner peripheral surface of the flange portion 10A, and a fitting convex portion 16B is provided on the upper surface of the support tube mounting table 16. The flange portion 1 of the heater support tube 10 is placed on the support tube mounting table 16.
0A is placed so that the fitting step portion 18B and the convex portion 16B fit together.

Also in this second embodiment, the heater support cylinder 10
As in the first embodiment, since it is only placed on the support cylinder mounting table 16 and is not restrained (fixed), it can freely expand and contract due to thermal expansion, and the generated thermal stress is lower than that of the conventional technology. This is significantly reduced to one-third or less compared to the conventional case, and deformation of the heater support cylinder 10 is prevented.

Further, an experiment similar to that in the first embodiment was conducted, and the same results as in the first embodiment were obtained in the second embodiment.

3 to 5 show a third embodiment of the present invention, in which the heater support cylinder 10 has a wall thickness that is thicker in the lower part where the temperature gradient is large, that is, in the region where the thermal stress is large, than in the upper part. The thick portion 10C is provided to increase the strength of the heater support cylinder 10 and prevent it from deforming.

In FIG. 3, the thick portion 10C of the heater support cylinder 10 extends from the top to the bottom slightly more than the upper surface 8A of the workpiece mounting table 8, and in FIG. is the processing object mounting table 8
It extends from slightly below the upper surface 8A to the lower end. Further, in FIG. 5, the thick portion 10C of the heater support tube 10 is located only in a region below the upper surface 8A of the processing object mounting table 8, where the temperature gradient is particularly large.

Therefore, in the third embodiment, the thickness of each heater support cylinder 10 is set to 6 mm, and the thickness of the thick portion 10C of the third embodiment is set to 10 mm, under the same conditions as the experiment conducted in the first embodiment. As a result of the experiment,
In the conventional technology, the lower part of the heater support cylinder 10 deforms after approximately 50 cycles of operation, making it unusable, but in the third embodiment, the heater support cylinder 10 deforms even after 100 cycles or more of operation. I was able to continue driving without any problems.

In addition, in the third embodiment, the heater support cylinder 10
By using a material with high strength for the thick portion 10C, it is possible to prevent deformation.

Also, means 16, 10A, 10 for preventing deformation.
C is used in combination with each other (e.g. 16 and 10
C or 10C and 10A) can also be used, which is even more effective.

(Effects of the invention) As described in detail above, in the invention according to claim 1, the heater support cylinder 10 is placed on the heater support cylinder mounting base 16 provided on the lower lid to heat the pressure vessel 5 in the radial direction. Since it is mounted to allow expansion, restraint on expansion and contraction due to thermal expansion of the heater support cylinder 10 is eliminated, and thermal stress is significantly reduced.
Therefore, deformation of the heater support cylinder 10 is prevented, and productivity can be improved by extending its life.

Further, in the present invention according to claim 2, the thick portion is placed in the lower portion of the heater support cylinder 10 in the portion where the temperature gradient is large.
Since the bending stress is generally inversely proportional to the square of the wall thickness, the generated stress can be suppressed to about 1/4, and deformation of the support tube 10 is prevented.

[Brief explanation of the drawing]

Fig. 1 is a central longitudinal cross-sectional schematic view of a HIP device showing a first embodiment of the present invention, Fig. 2 is a vertical cross-sectional view of main parts showing a second embodiment of the present invention, and Figs. FIG. 6 is a central longitudinal cross-sectional view of a conventional example of the HIP device, FIG. 7 is a partially cutaway side view showing the support structure of the heater, and FIG. It is a sectional view taken along the line AA in the figure. 5... Pressure vessel, 8... Processing material mounting table, 8A...
...Top surface, 9...Heater, 10...Heater support cylinder,
10A...Flange part, 10C...Thick wall part, 1
6...Support cylinder mounting table.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A pressure vessel, an upper cover and a lower cover that removably close the upper and lower openings of the pressure vessel in the axial direction, and a processing material mounting table placed on the lower cover. , a hot isostatic pressing apparatus having a heater disposed around the workpiece mounting table, and a heater support cylinder provided on the lower lid and supporting the heater, wherein the heater support cylinder . A hot isostatic pressing apparatus, characterized in that the pressure vessel is placed on a heater support cylinder mounting table provided on the lower lid so as to allow thermal expansion in the radial direction of the pressure vessel. (2) A pressure vessel, an upper lid and a lower lid that removably close the upper and lower openings of the pressure vessel in the axial direction, a processing material mounting table placed on the lower lid, and the surroundings of the processing material mounting table. In the hot isostatic pressing apparatus, the hot isostatic pressing apparatus has a heater disposed on the lower lid, and a heater support tube that is provided on the lower lid and supports the heater, wherein a A hot isostatic pressing device characterized by being provided with a meat portion.