JPS6327404B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hot press apparatus with an improved structure for controlling the atmosphere.

Certain porcelain materials, such as BaTiO _a porcelain,
PZT-based porcelain and PZT magnetism require hot pressing in an oxidizing atmosphere. Otherwise, it is impossible to obtain a dense sintered body,
Another reason is that it is difficult to obtain a sintered body with predetermined characteristics. Furthermore, ferrite is hot-pressed in a nitrogen gas atmosphere in which the oxygen partial pressure is strictly controlled. Therefore, with such porcelain materials, atmosphere control becomes an important issue.

Conventionally, an apparatus shown in a schematic front sectional view in FIG. 1 has been used to control the atmosphere during hot pressing. Sample 1 to be pressed is
Placed in mold 2. The mold 2 consists of an alumina thin plate 3, an upper punch plug 4, and a lower punch plug 5. An upper punch rod 7 is arranged above the upper punch stopper 4. This upper punch rod 7 is attached to a punch holder 9 via a connecting portion 8. On the other hand, a lower punch rod 10 is arranged below the lower punch stopper 5, and this lower punch rod 10 is attached to a punch holder 12 via a connecting portion 11. Pressing of the sample 1 is achieved by moving the punch holders 9 and 12 in the direction where the mold 2 is present.
Flange-shaped seal members 14 and 15 are attached to the punch holder 9 and the punch holder 12. The mold 2, the upper punch rod 7, the lower punch rod 10, and other parts configured as described above are arranged in the combustion tube 16 made of alumina. Combustion tube 16
is provided to surround the sample 1 with atmospheric gas. Atmospheric gas is blown into a space surrounded by the combustion tube 16, the seal member 14, and the seal member 15 through a pipe 17 inserted through a portion of the seal member 15. A heater 18 serving as a furnace is provided outside the combustion tube 16, and the sample 1 can be heated simultaneously with pressing by this heater 18. Note that a ring-shaped seal 19 is provided between the seal member 14 and the flange portion 16a of the combustion tube 16. Similarly, a ring-shaped seal 20 is also installed between the combustion tube 16 and the flange portion 16b of the combustion tube 16. During hot pressing, the space inside the combustion tube 16 is heated to a high temperature, so
The gas in the combustion tube 16 expands, which may cause seals 19 and 20 to fail. Therefore, seal 19,
Cooling pipes 21 and 22 are provided where 20 is located, respectively. Cooling water is circulated inside the cooling pipes 21 and 22, thereby sealing the seals 19 and 2.
0 cooling takes place. Cooling pipes 23 are also attached to the punch holder 9 and the punch holder 12 in order to prevent the punch holders from being heated.

The conventional hot press device shown in Fig. 1 is a type of multi-stage hot press device.
A plurality of samples can be hot-pressed continuously by sequentially replacing a series of structures including the die 2, punch member, etc. as shown in the figure within the combustion tube 16.

In the conventional hot press device configured as described above, the combustion tube 16 and the seal members 14, 15
The space formed by this is sealed, and hot pressing is performed while introducing atmospheric gas into this space.
However, as is clear from FIG. 3, which shows an enlarged view of the area indicated by circle A in FIG. , there is no room for gas to enter around the sample 1. That is, even if the necessary atmospheric gas is introduced into the combustion tube 16, as the pressing operation progresses, the sample 1 will not be exposed to the atmospheric gas, and there is a drawback that the atmosphere cannot be accurately controlled during hot pressing. did. Note that 6 indicates a mold release agent, which is filled in order to facilitate the removal of sample 1 after pressing. In addition, as mentioned above, the combustion tube 1
The flange portion 16a of the combustion tube 16 and the seal member 14 are sealed with a seal 19, and the combustion tube 16 and the flange portion 16a of the combustion tube 16 are sealed with a seal 20. There was also the disadvantage that the entire apparatus was extremely large and complex, since cooling pipes 21, 22 and other additional cooling devices were required for this purpose.
Furthermore, since the cooling water is used for cooling, if the cooling pipes 21, 22, etc. are damaged, the cooling water may leak into the combustion pipe 1.
Accidents of leakage within the unit often occurred. In particular, if the cooling pipe 21 located above is damaged, the cooling water may adhere to the hot punch rods 7, 10, etc., which can lead to extremely serious accidents such as damage to the punch rods 7, 10. Ta.

Therefore, the main object of the present invention is to provide a hot press apparatus with a simple structure that can efficiently control the atmosphere.

The hot press device according to the present invention has a thin upper punch stopper and a lower punch stopper, and includes a mold for pressing a sample, and an upper punch stopper that is arranged above the punch stopper and comes into contact with the upper end of the upper punch stopper. The mold includes a punch rod, a lower punch rod that is arranged below the lower punch stopper and comes into contact with the lower end of the lower punch stopper, and a furnace for heating the sample placed inside the mold. In the hot press apparatus according to the present invention, a hot press is provided that penetrates the inside of at least one of the upper punch plug and the lower punch plug between the punch rod side end surface and the sample side end surface of the punch plug, and allows atmospheric gas to flow into the sample. A first hole is formed for directly introducing an atmospheric gas into the mold.
Furthermore, among the upper punch rod and the lower punch rod,
A second hole that communicates with the first hole and sends atmospheric gas is formed inside the punch plug that corresponds to the punch stopper provided with the first hole.

Other objects and features of the present invention will become more apparent from the following detailed description with reference to the drawings.

FIG. 4 is a side sectional view showing one embodiment of the present invention. The feature of this embodiment is that the upper punch plug 34, the lower punch plug 35, the upper punch rod 37, and the lower punch rod 40 arranged above and below the sample 1 have holes 34a, 35a, 37a, 40a for introducing atmospheric gas. are formed respectively. That is,
The atmosphere around the sample 1 during hot pressing is formed by the atmospheric gas introduced through the holes 34a, 35a, 37a, and 40a. The atmospheric gas may be blown in from below or from above. That is, it may be blown into the sample 1 from the lower punch plug 35 side and discharged from the upper punch plug 34 side, or the upper punch plug 3
Alternatively, the sample 1 may be blown into the sample 1 from the 4 side and discharged from the lower punch stopper 35 side. Another feature of this embodiment is that members for retaining atmospheric gas, such as the combustion tube 16, which were necessary in the conventional hot press apparatus shown in FIG. 1, are omitted. This is because, as is clear from FIG. 5, which is an enlarged view of circle B in FIG. It is sealed in a closed space. Therefore, the atmospheric gas blown from the upper punch plug 34 or the lower punch plug 35 is transferred to the mold 32.
This is because the atmospheric gas concentration of the sample 1 can be maintained at a desired concentration without using a combustion tube. The rest of the structure is the same as the conventional hot press device shown in FIG. 1, so corresponding parts will be given corresponding reference numerals and their explanation will be omitted.

Preferably, seals made of, for example, asbestos are installed between the upper punch plug 34 and the upper punch rod 37 and between the lower punch plug 35 and the lower punch rod 40. This seal makes it possible to effectively prevent atmospheric gas from leaking out of the mold 32. Furthermore, it should be pointed out that the holes for introducing atmospheric gas are not limited to those described above.

As described above, according to the hot press apparatus according to the present invention, an atmospheric gas can penetrate into at least one of the upper punch stopper and the lower punch stopper between the end face on the punch rod side and the end face on the sample side of the punch stopper. A first hole is formed for introducing atmospheric gas into the mold so as to blow directly into the sample, and one of the upper punch rod and the lower punch rod corresponds to the punch stopper provided with the first hole. Since a second hole is formed inside to communicate with the first hole and send atmospheric gas, it is possible to easily and reliably control the concentration of atmospheric gas during hot pressing with a small amount of atmospheric gas. It becomes possible to obtain the desired sintered body. Moreover, unlike conventional hot press equipment, there is no need for a cooling device to prevent extra combustion tubes and seals from heating, so the entire equipment can be made simple and compact.

Furthermore, the present invention can be advantageously applied to a multiple hot press apparatus for sequentially hot pressing a plurality of samples. That is, since a combustion tube is not used, there is no need to form a fixed space filled with atmospheric gas, and therefore, continuous hot pressing can be easily performed by simply placing molds and punches in sequence in a furnace containing a heater. becomes possible.

[Brief explanation of the drawing]

FIG. 1 is a schematic front sectional view showing a conventional hot press apparatus. FIG. 2 is a front sectional view showing parts that are moved when the hot press device shown in FIG. 1 is used as a multiple hot press device. FIG. 3 is an enlarged view of circle A in FIG. FIG. 4 is a front sectional view showing an embodiment of the present invention. FIG. 5 is an enlarged front sectional view of circle B in FIG. 4. In the figure, 1 is a sample, 32 is a mold, 33 is a thin plate, 34 is an upper punch plug, 34a is a hole, 35 is a lower punch plug, 35a is a hole, 37 is an upper punch rod, 37a
40 is a hole, 40 is a lower punch rod, 40a is a hole, and 48 is a heater as a furnace.

Claims (1)

[Claims] 1. Thin, having an upper punch stopper and a lower punch stopper,
a mold for pressing a sample; an upper punch rod arranged above the punch stopper and abutting the upper end of the upper punch stopper; and a lower end of the lower punch stopper arranged below the lower punch stopper. A hot press device comprising a lower punch rod that comes into contact with the mold, and a furnace for heating a sample placed inside the mold, wherein a punch of the punch plug is placed inside at least one of the upper punch plug and the lower punch plug. A first hole is formed to penetrate between the rod side end surface and the sample side end surface and for introducing atmospheric gas into the inside of the mold so as to blow the atmospheric gas directly into the sample, and the upper punch rod and the lower punch rod A hot press device, wherein a second hole is formed in the punch rod corresponding to the punch stopper provided with the first hole to communicate with the first hole and send atmospheric gas.