JPH0646139B2 - Sintering furnace - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a sintering furnace used for sintering ceramics, metal powder or the like.

[Prior Art] As a conventional sintering furnace, a horizontally long inner case is arranged inside a horizontal type furnace body in which a heater is provided on an inner wall, and a lid is provided at both ends of the inner case. In some cases, an air supply pipe is directly connected to the furnace body from the outside of the furnace body, and an exhaust port communicating with the outside of the furnace body is provided.

In order to sinter the material to be processed in such a furnace, after arranging the material to be processed on the hearth inside the inner case, first close the lids at both ends to heat the inner case and through the air supply and exhaust pipes. The atmosphere gas is circulated in the inner case to degrease the object. The harmful gas generated from the object to be treated during the degreasing step is exhausted from the exhaust port to the outside of the furnace body. After cleaning the inside of the object and the inner case in this way, heat the object for a predetermined time to sinter the object, then open the lids on both ends and circulate cool air inside the inner case for sintering. The object to be processed is cooled.

[Problems to be Solved by the Invention] By the way, in the conventional sintering furnace, since it is a horizontal type as described above, the installation space becomes large, and the object to be processed is carried along with the inner case. In addition, the transportation equipment such as a trolley becomes large, and depending on the type of the object to be treated, it may be deformed during heating by placing it horizontally.In the case of such an object to be treated, degreasing and baking are performed. The knot had to be processed using different furnaces.

Further, when degreasing or cooling, atmospheric gas is introduced into and discharged from the inner case through an air supply / exhaust pipe that communicates with the inner case.At this time, hot air accumulates in the upper part of the inner case and these There is also a problem that degreasing and cooling cannot be performed efficiently.

[Means for Solving the Problems] The present invention has been made to solve the above problems, and a heater is provided on the inner wall of a cylindrical vertical furnace body, and the heater is provided inside the furnace body. An inner case into which the material to be processed is loaded is provided. The inner case is arranged so as to close the tubular case body and the upper and lower openings of the case body, and to be separable from the openings. A top cover and a bottom cover, and an elevating mechanism capable of elevating the top cover from the outside of the furnace body in two steps is connected to the top cover. It is characterized in that the upper opening and the upper lid of the main body are connected to each other by a connecting member that also separates the case main body and the bottom lid, and the bottom lid is connected to an exhaust pipe communicating with the outside of the furnace body.

[Operation] In order to sinter the object to be processed by the sintering furnace of the present invention, first, the upper cover of the inner case is raised by one step by the elevating mechanism, and the atmosphere is changed from the upper opening of the case body toward the exhaust port of the bottom cover. A gas is caused to flow, and in this state, the object to be processed is heated by a heater to degrease it. At this time, even if harmful gas is emitted from the object to be processed, the inner wall of the furnace body and the heater are not contaminated with the harmful gas. Moreover, since the atmospheric gas flows from the upper part to the lower part of the inner case, the atmospheric gas does not collect in the upper part of the inner case, and the inner case can be efficiently cleaned.

Next, the upper lid is lowered to seal the inner case, and the object to be processed is sintered.

Next, the heating by the heater is stopped and the furnace body is cooled. At this time, the cool air for cooling is supplied into the heating chamber by forced circulation by a fan or natural circulation in the furnace. At the same time, the lifting mechanism raises the upper lid in two steps to open the upper and lower openings of the case body. Then, the cooled gas inside the furnace body circulates from the lower opening to the upper opening of the inner case, whereby the cooling effect of the object to be treated becomes large and the cooling time is short.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 to 6.

In FIG. 1, reference numeral 1 is a furnace body, which is hinged to a furnace body 2 and is provided so as to be openable and closable so as to close a furnace opening 2a of the furnace body 2. Furnace lid 3
The furnace body 1 has a cylindrical shape with the furnace lid 3 closed, and is of a vertical type in which its axis coincides with the vertical direction. Insulating walls 4 and 5 are provided inside the furnace body 2 and the furnace lid 3, respectively, and heaters 6 are provided on the inner surfaces of these insulating walls 4 and 5. And
The inside of the heat insulating walls 4 and 5 when the furnace lid 3 is closed becomes a heating chamber 7.

The inside of the furnace main body 2 will be described in detail with reference to FIG. 3. An upper opening 8a is opened in the upper part of the heat insulating wall 4 provided inside, and the upper opening 8a has a tapered peripheral edge and is heated. It is closed by an upper bung 9a which is prevented from falling into the chamber 7. The upper bang 9a is detachably mounted on the peripheral edge of the upper opening 8a.

A hearth 12 is fixed to the bottom of the heating chamber 7 via a plurality of support rods 11 fixed to the furnace body 2 and penetrating the bottom of the heat insulating wall 4. An exhaust port 12a is formed in the center of the hearth 12. Further, at the center of the bottom of the heat insulating wall 4, the hearth 1
A lower port 8b corresponding to the two exhaust ports 12a is formed, and the lower port 8b is closed by a removable lower bang 9b. The lower bung 9b is moved up and down by an opening / closing mechanism such as a cylinder (not shown), so that the lower opening 8b can be opened and closed.

An exhaust pipe 13 penetrating the lower bang 9b is attached from the exhaust port 12a of the hearth 12 to the outside of the bottom of the furnace body 3. An exhaust device (not shown) is connected to the tip of the exhaust pipe 13. In addition, a gas supply pipe (not shown) that supplies an atmosphere gas to the space between the furnace body 2 and the heat insulating wall 4 is connected to the side wall of the furnace body 2. This gas supply pipe may penetrate the heat insulating wall 4 and be opened in the heating chamber 7.

A cooling jacket J (of which the furnace lid 3 is not shown in FIG. 3) to which cooling water is supplied is provided inside the furnace body 2 and the furnace lid 3.

An inner case 14 is placed on the hearth 12. This inner case 14 is, as shown in FIG.
A cylindrical case body 17 having upper and lower openings and flanges 15 and 16 formed on the upper and lower opening edges, a disk-shaped upper lid 18 for closing the upper opening 17a, and a lower opening 1
The case main body 17 is arranged coaxially with the furnace body 1.

The outer diameter of the upper lid 18 is substantially the same as that of the upper flange 15, and the upper lid 18 is longer than the combined thickness of the upper flange 15 and the upper lid 18, and has a disc-like upper and lower engagement. They are connected by a lifting rod 20 (connecting member) having joints 20a and 20b. The lifting rod 20 is loose in the rod insertion hole 21 formed in the circumferential portion of the upper lid 18 and the upper flange 15 (the upper lid 18 side cannot be seen in FIG. 2) so as to be axially movable. It is inserted in the state. This lifting rod 20
Are arranged in a plurality of places on the circumference of the upper lid 18 at equal intervals.

The outer diameter of the bottom cover 19 is also substantially the same as that of the lower flange 16, and the peripheral edge of the lower opening 17a of the case main body 17 is fitted on the upper surface of the bottom cover 19 so as to position the case main body 17. Are formed. Guide rods 22 extending vertically upward are fixed to the circumferential portion of the bottom lid 19 at a plurality of circumferentially equally divided portions. This guide rod 22
Penetrates loosely into a rod insertion hole 16a formed in the lower flange 16 of the case body 17. Also, the bottom lid 1
An exhaust port 19b communicating with the exhaust port 12a of the hearth 12 is formed in the center of the furnace 9.

As shown in FIG. 2, a screw jack (elevating mechanism) 23 is provided on the furnace main body 2, and the screw jack 23 is an abbreviation for the upper bang 9a that closes the upper opening 8a of the heat insulating wall 4. It is connected to a bracket 26 provided on the upper surface of the upper lid 18 of the inner case 14 via a lifting rod 24 and a joint 25 penetrating the center. The joint 25 is detachably connected to the bracket 26 by a pin 27. Also, the upper bang 9 of the lifting rod 24
A support 28 for lifting the upper bung 9a is fixed at a predetermined position below a.

The screw jack 23 operates so as to move the lifting rod 24 forward and backward with two strokes. Then, the inner case 14 and the upper bang 9a
And the screw jack 23 have the following operational relationship.

When the elevating rod 24 is in the most extended state, FIG.
As shown in FIG. 2, the upper lid 18 of the inner case 14 is mounted on the upper flange 15 of the case body 17 and is attached to the upper opening 17a.
In a state in which the lifting rod 24 is retracted by one step, the upper lid 18 is lifted by the lifting rod 20 and the upper opening 17a of the case body 17 is opened to move the lifting rod 24, as shown in FIG. 6 (a). When retracted by another step, as shown in FIG. 6C, the upper and lower engaging portions 2 of the lifting rod 20 are engaged.
0a and 20b are the upper lid 18 and the case body 17, respectively.
Of the upper cover 15 and the case body 17 rise together with the upper lid 18 in a state where there is a gap between the upper lid 18 and the upper flange 15, and the upper bang 9a is lifted by the support 28, and The mouth 8a opens.

Next, a procedure for sintering the object to be processed by using the sintering furnace having the above configuration will be described. First, an example of a method for setting the object to be processed in the furnace will be described with reference to FIG. explain.

First, as shown in FIG. 4 (a), the guide rod 22 directs the bottom lid 19 of the inner case 14 upward on the work table 31 having the two fork insertion grooves 30 formed on the upper surface. In this state, a plurality of sample cases 32 containing the object to be processed are stacked on the bottom lid 19. A ventilation hole 32 a is formed in the sample case 32.

Then, as shown in FIG. 4 (b), the inner case 14
The case main body 17 is hung up together with the upper lid 18 by the lifting tool 33, and then the case main body 17 and the upper lid 18 are lowered so that the sample case 32 is loaded into the case main body 17, and the case main body 17 is placed on the bottom lid 19. . At this time, the bottom lid 19
The guide rod 22 is inserted into the rod insertion hole 16a formed in the lower flange 16 of the case body 17.

Next, the fork 34 of the carrier with a fork (not shown) is inserted into the fork insertion groove 30 of the workbench 31, and the inner case 14 in which the sample case 32 is loaded as shown in FIG. And the inner case 14 is placed on the furnace floor 12 at the bottom of the heating chamber 7 while being carried by the carrier to the furnace body 1 of the sintering furnace. At this time, the bottom lid 19
The exhaust port 19b of No. 1 and the exhaust port 12a of the hearth 12 are aligned. Then, the joint 25 connected to the screw jack 23 and the bracket 26 of the upper lid 19 are connected by the pin 27.

As shown in FIG. 5, the bracket 26 of the upper lid 18
Instead of this, a hook 29 of hook type may be used, and the hook 29 may be hooked on the joint 25, whereby the pin connecting work can be omitted.

Next, the procedure for actually sintering the object to be processed will be described. First, the furnace lid 3 is closed, and the screw jack 23 is operated so as to be in the state of the above item-FIG.
Also, the lower bung 9b is closed. And the heater 6
Thus, the temperature inside the heating chamber 7 is raised to a predetermined temperature, and the object to be treated is degreased. At this time, the exhaust device connected to the exhaust pipe 13 provided in the hearth 12 is operated.

As a result, the atmospheric gas inside the inner case 14 is exhausted from the exhaust pipe 13 through the bottom lid 19 of the case body 17 and the exhaust ports 19b and 12a formed in the hearth 12, and the object to be treated and the heating chamber 7 are discharged. The inside becomes clean.

Next, the screw jack 23 is operated to close the inside of the heating chamber 7 from the above state to the state of the above item-FIG. Sinter the processed material.

Subsequently, the heating by the heater 6 is stopped, the screw jack 23 is operated so as to be in the state described in the above section (FIG. 6C), and the lower bung 9b is raised by the opening / closing mechanism to lower the lower port of the heat insulating unit 4. Open 8b.

As a result, the low-temperature atmosphere gas inside the furnace body 1 is cooled by natural convection or gas circulation, and this cooling gas is introduced into the heating chamber 7 through the lower opening 8b of the heat insulating wall 4, and
From the lower opening 17b of the case body 17 to the inner case 14
Will be introduced in. Then, after this, the cooling gas passes through the upper opening 17a of the case main body 17 and exits from the upper opening 8a of the heat insulating wall 4, and then descends through the space between the heat insulating wall 4 and the furnace body 1 and again in the heat insulating wall 4. It enters the inside of the heat insulation wall 4 from the lower opening 8b. In this way, the cooling gas circulates in the furnace body 1 and the object to be processed is cooled.

According to the above-described sintering furnace, even if a harmful gas is generated from the object to be treated during the degreasing process, this gas is exhausted to the outside of the furnace body 1 along with the flow of the atmospheric gas and is removed. Does not leak into the space between the inner case 14 and the inner case 14.
Therefore, the heat insulating walls 4, 5 and the heater 6 can be prevented from being contaminated with harmful gas. Also, during this degreasing treatment,
Since the atmospheric gas flows from the upper part to the lower part of the inner case 14, the atmospheric gas does not accumulate in the upper part of the inner case 14, and as a result, the inner case 14 can be efficiently cleaned and the atmospheric gas can be supplied. The amount can be suppressed to the necessary minimum.

Further, in the cooling step, the cooling gas is circulated so as to be introduced from the lower side of the inner case 14, so that the cooling effect of the object to be processed is large, and thus the cooling time is short.

Further, since this sintering furnace is of a vertical type, its installation space is smaller than that of a conventional horizontal type, and the carrier carrying the inner case 14 may be compact. There is.

[Effects of the Invention] As described above, according to the sintering furnace of the present invention, since it is a vertical installation type, its installation space is smaller than that of a conventional horizontal installation type, and a transportation vehicle carrying an inner case. Is better with a compact one.

In addition, when degreasing the object to be processed, by raising the upper lid of the inner case by one step by the elevating mechanism, sucking atmospheric gas from the exhaust port of the bottom lid and directing the gas flow from the upper to the lower of the inner case. Even if harmful gas is emitted from the object to be processed, the inner wall of the furnace body and the heater are not contaminated by the harmful gas, and atmospheric gas does not collect in the upper part of the inner case, resulting in efficient inner case It is possible to reduce the supply amount of the atmospheric gas to the necessary minimum.

Further, when the object to be processed is cooled after sintering, the upper lid is raised by two steps by the elevating mechanism to open the upper and lower openings of the case body, and the cooling gas is introduced into the inner case through these upper and lower openings. , And by circulating
The cooling effect is great and the cooling time is short.

[Brief description of drawings]

1 to 6 show an embodiment of the present invention. FIG. 1 is a perspective view showing a state in which a furnace lid is open, FIG. 2 is a perspective view of an inner case, and FIG. FIG. 4 is a longitudinal sectional view, FIGS. 4 (a), (b), and (c) are views for explaining a method of setting the inner case in the furnace body, FIG. 5 is a perspective view showing a modified example of the bracket of the inner case, and FIG. (A) (b) (c) is a figure explaining the procedure of sintering. 1 ... Furnace body, 6 ... Heater, 13 ... Exhaust pipe, 14 ... Inner case, 17 ... Case body, 17a ... Top opening, 17b ... Bottom opening, 18 ... Top lid, 19 ... Bottom Lid, 20 ... Lifting rod (connecting member), 23 ... Screw jack (elevating mechanism).

Claims (1)

[Claims] 1. A heater is provided on an inner wall of a cylindrical furnace body of a vertical type, and an inner case for loading an object to be processed is arranged inside the furnace body. The inner case has a cylindrical shape. It consists of a case body, and an upper lid and a bottom lid which are arranged so as to cover the upper and lower openings of the case body, respectively, and which can be separated from the openings. The upper lid is provided in two stages from outside the furnace body. The upper lid and the case main body are connected to each other, and the upper lid and the case body are separated from each other with the upper opening and the upper lid of the case body separated from each other when the upper lid is raised in the second stage by the elevating mechanism. The sintering furnace is characterized by being connected by a connecting member, and an exhaust pipe communicating with the outside of the furnace body is connected to the bottom lid.