JPS6370089A - Sintering furnace - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention "Field of Industrial Application" The present invention relates to a sintering furnace used for sintering ceramics, metal powders, etc. It is related to furnaces.

"Prior Art" Conventionally, as a sintering furnace used for sintering ceramics, metal powder, etc., a structure shown in FIG. 4, for example, is known.

The sintering furnace 1 includes a furnace shell 2, a heating casing 3 disposed inside the furnace shell 2 to form a heating chamber A, and a heater 4 disposed within the heating casing 3. The heating casing 3 is made of a heat insulating material, and the heater 4 uses a resistance heating element or the like.

After charging the workpiece W into the heating casing 3, the heating casing 3 and the furnace shell 2 are closed,
The inside of the closed heating casing 3, that is, the inside of the heating chamber A is heated by the heater 4, and the workpiece W charged therein is sintered.

"Problems to be Solved by the Invention" The present invention is an attempt to solve the following problems in the conventional technology mentioned above.

That is, in the sintering furnace I having the above-mentioned configuration, during heating, the gas inside the furnace shell 2 and the heating chamber A causes natural convection as shown by the arrows in FIG. It moves towards the top of chamber A and stays there,
As a result, there is a problem in that a temperature difference is avoided between the upper and lower parts of the furnace shell 2 and heating casing 3.

Since such problems have a negative effect on the quality of the object W after sintering, countermeasures are required.

Furthermore, in general sintering furnaces, sintering is performed in a pressurized atmosphere in order to improve the quality of the workpiece W after sintering, and in recent years, the material of the workpiece W has been In some cases, sintering is performed under a high pressure atmosphere of approximately 10,100 m/cm.

However, under the above-mentioned high-pressure atmosphere, as the gas density increases, the above-mentioned rising tendency of hot air is accelerated, and the temperature difference between the furnace shell 2 and the heating chamber A is further expanded. cause

"Means for Solving the Problems" The present invention aims to provide a sintering furnace that can effectively solve the conventional problems described above. A heating casing disposed inside the furnace shell to form a heating chamber; an inner case disposed inside the heating casing and into which a workpiece is charged; and the inner case and the heating casing. and a heater disposed between the heating casing and the heating casing, the inner case is rotatably mounted within the heating casing, and a drive mechanism for rotating the heating casing is connected to the inner case. .

"Function" The sintering furnace according to the present invention rotates the inner case via the support roller by the drive mechanism, thereby forcibly stirring the gas in the furnace shell and heating chamber to prevent hot air from stagnation. It equalizes the temperature inside the furnace shell and heating chamber.

"Example" An example of the present invention will be described below with reference to FIGS. 1 and 2.

In FIGS. 1 and 2, reference numeral 5 indicates a sintering furnace according to the present embodiment, which includes a furnace shell 6, a heating casing 7 disposed inside the furnace shell 6 and forming a heating chamber A, The heating casing 7 includes an inner case 8 which is disposed inside the heating casing 7 and into which the workpiece W is charged, and a heater 9 which is disposed between the inner case 8 and the heating casing 7. The inner case 8 is rotatably mounted in the heating casing 7, and a support roller lO is placed in the heating casing 7 to be brought into contact with the outer surface of the inner case 8.
It has a schematic configuration in which a drive mechanism 11 that rotates the inner case 8 by rotationally driving the support roller IO is connected to the support roller IO.

Next, to explain these details, the furnace shell 6 is composed of a bottomed cylindrical furnace body 6a, and a furnace cover 6b that is detachably attached to the furnace body 6a so as to cover the opening of the furnace body 6a. There is.

The heating casing 7 is formed of a heat insulating material, and, as shown in FIGS. 1 and 2, includes a bottomed cylindrical casing body 7a, and is removably attached to the casing body 7a so as to cover the opening of the casing body 7a. The lid body 7b is arranged inside the furnace shell 6.
b, and is supported by the heating casing 7 via a spacer (not shown), so that it is inserted between the inner peripheral surface of the furnace shell 6 and the entire circumference. It is designed to form a gap.

Like the heating casing 7, the inner case 8 is composed of a bottomed cylindrical base 8a and a lid 8b removably attached to the base 8a to cover the opening thereof. The outer shape is inserted into the heating casing 7 with the bottom of the base 8a first, and in the inserted state, forms a gap with the inner circumferential surface of the heating casing 7 over the entire circumference. The shape is set.

Further, a tray 12 on which the object to be processed W is placed is disposed inside the inner case 8, and the tray 12 includes the bottom of the base 8a of the inner case 8 and the heating casing 7. A support rod 13 is provided to penetrate through the bottom of the casing body 7a, and is integrally connected thereto, and the support rod 13 is fixed to the inner surface of the bottom of the furnace body 6a, as shown in FIG. The tray 12 is thereby connected to the furnace shell 6.

A heating casing 7 is provided in the portions of the base body 8a and the casing body 7a through which the support rods 13 are penetrated.
A sealing material (path shown in the figure) is interposed to maintain the airtightness of the inner case 8, and the base 8a
The penetrating portion between the support rod 13 and the support rod 13 is configured to allow relative rotation between the two.

In this embodiment, as shown in FIGS. 1 and 2, the support rollers 1O are provided at four locations at intervals in the circumferential direction and the length direction of the inner case 8, and Two support rollers 10 provided along the heating casing 7 are set as one set, and for each set, the support rollers 10 are provided with a drive shaft 14 rotatably provided through the bottom of the heating casing 7.
The inner case 8 is integrally attached to the heating casing 7 and is brought into contact with the lower part of the inner case 8, thereby positioning the inner case 8 within the heating casing 7.

The heater 9 is arranged in the gap between the heating casing 7 and the inner case 8 along the length direction of the inner case 8 as shown in FIG. 1, and as shown in FIG.
A plurality of them are provided at intervals in the circumferential direction of the inner case 8.

The drive mechanism 11 includes an electric motor 15 attached to the bottom outer surface of the furnace body 6a, and a reducer 16 provided between the electric motor 15 and the drive shaft 14. The rotating shaft 15a passes through the bottom of the furnace body 6a and connects to the drive shaft 1 inside the furnace body 6a.
4, and these drive shafts 1
The speed reducer 16 is provided between the rotary shaft 15a and the rotary shaft 15a. In this embodiment, a group of gears is used as the reducer 16.

Thus, in the sintering furnace 5 of this embodiment configured as described above, the inner case 8 is opened by removing the furnace lid 6b and the lids 7b and 8b in sequence, and the tray 12 inside the inner case 8 is opened.
After loading the workpiece W onto the inner case 8,
, the starting condition for the sintering operation is set by closing the heating casing 7 and the furnace shell 6. .

From this, heating by the heater 9 is started, and the drive mechanism 11 is started to rotate the inner case 8, thereby starting the sintering operation, and increasing the internal temperature of the heating chamber A and the internal temperature of the inner case 8. Temperature equalization begins. The rotation of the inner case 8 at this time is set to about L rpm.

That is, most of the heat supplied from the heater 9 is transferred to the gas inside the inner case 8 via the inner case 8 and is used to heat the gas, and furthermore, the heat of the gas is transferred to the gas inside the inner case 8. By being supplied to the object W, the object W to be processed is sintered.

On the other hand, as the inner case 8 rotates, the gas in contact with the inner and outer surfaces of the inner case 8 is moved together with the inner case 8 in the direction of rotation, so that the gas inside the heating casing 7 and the inner case The gas in the furnace shell 6 is prevented from refluxing in the circumferential direction of the furnace shell 6.
As a result, the gas in both cases 7 and 8 is forcibly stirred.

Therefore, even if hot air rises to the upper part of the sintering furnace 5 due to heating by the heater 9, the hot air is immediately directed down to the lower part of the sintering furnace 5 and mixes with low-temperature gas. As the temperature of the sintering furnace 5 approaches the set temperature, the internal temperature becomes uniform.

When the temperature inside the heating casing 7 and the inner case 8 is made uniform in this way, the amount of heat supplied to each part of the workpiece W is also made uniform, so the workpiece W The quality of the products will be improved.

Furthermore, for example, even if a slight temperature difference occurs between the upper and lower parts of the heating casing 7, the inner case 8 is rotated and periodically alternated between the high temperature part and the low temperature part, as described above. Since they are brought into contact with each other, the temperature distribution of the inner case 8 itself is equalized, and as a result, the internal temperature of the inner case 8 and, by extension, the heat supplied to the workpiece W are also uniform as in the above-mentioned state. be converted into

Note that the shapes and dimensions of each component shown in the above examples are merely examples, and can be changed in various ways based on changes in the type of workpiece W to be sintered, sintering conditions, design requirements, etc. be.

For example, an example has been shown in which the tray 12 on which the workpiece W is placed is supported on the bottom inner surface of the furnace body 6a via the support rod 13, but instead of this, as shown in FIG. Alternatively, it may be supported on the peripheral surface of the furnace body 6a. With such a configuration, it is possible to cope with an increase in the weight of the workpiece W by supporting the workpiece W from below. Furthermore, as described above, as the workpiece W increases in size, the inner case 8 is forced to increase in size, but in this case, the inner case 8 is divided into two lengthwise as shown in FIG. Then, a drive mechanism (only the drive shaft 17 is shown in the figure) may be connected to each of them to rotate them individually.

By having such a configuration, the inner case 8
The load on the drive mechanism due to the increase in size of the inner case 8 can be reduced, and the rotation of the inner case 8 can be made smooth.

"Effects of the Invention" As explained above, the sintering furnace according to the present invention includes a furnace shell, a heating casing disposed inside the furnace shell to form a heating chamber, and a heating casing arranged inside the heating casing. and a heater disposed between the inner case and the heating casing, and the inner case is rotatably mounted in the heating casing. In addition, to the inner case,
It is characterized by a continuous drive mechanism that rotates the inner case, and by rotating the inner case, the temperature of the inner case is made uniform, and the gas inside the furnace body and the inner case is forcibly removed. Even when the pressure inside the furnace is increased, the temperature of the gas inside the furnace body and inner case can be kept uniform, and the material to be processed can be heated uniformly, thereby improving its quality. It has excellent effects such as being able to improve

[Brief explanation of the drawing]

1 and 2 show an embodiment of the present invention,
FIG. 1 is a longitudinal cross-sectional side view, FIG. 2 is a cross-sectional view taken along the line ■-■ in FIG. 1, FIG. 3 is a schematic diagram showing another embodiment of the present invention, and FIG. 4 is a conventional FIG. 2 is a view similar to FIG. 2 showing a sintering furnace; 5... Sintering furnace, 6... Furnace shell, 6
a... Furnace body, 6b... Furnace lid, 7... Heating casing, 7a... Casing body, 7b... Lid body, 8
...Inner case, 8a...Base,
8b...Lid, 9...Heater, IO...Support roller, 11...
...Drive mechanism, I2...Tray, 13
・・・・・・Support rod, 14・17・・・・・・
Drive shaft, 15...Electric motor, 15a...
・Rotating shaft, 16...Reducer.

Claims (1)

[Claims] A furnace shell, a heating casing disposed inside the furnace shell to form a heating chamber, an inner case disposed inside the heating casing and into which a workpiece is charged, and the inner case. a heater disposed between the inner case and the heating casing, the inner case is rotatably mounted in the heating casing, and a drive mechanism for rotating the inner case is connected to the inner case. A sintering furnace featuring