JP3511376B2 - Muffle furnace - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a muffle furnace, and more particularly to a muffle furnace suitable for subjecting a work to a plurality of treatments.

[0002]

2. Description of the Related Art For electronic parts, when a process such as baking or sintering is performed, a dedicated furnace is used for the process. However, other than that, for example, a chemical reaction with various gases, In some cases, a muffle furnace that performs a process to prevent oxidation is used. In such a muffle furnace, usually one muffle furnace uses a single gas in order to avoid mixing with other gases.

FIG. 6 shows an example of a conventional muffle furnace. In the muffle furnace shown in the figure, an upper heater 2 and a lower heater 3 are installed at the upper and lower parts of the muffle body 1, and a gas inlet 4 is provided at the end of the muffle body 1 on the outlet 1b side, and an inlet 1a is provided. A gas outlet 5 is provided at the end on the side. Further, the work transfer mechanism 6 is installed, and the work transfer mechanism 6 drives the belt conveyor 7 in the z direction, so that the work W on the belt conveyor 7 is carried into the muffle body 1 from the inlet 1a of the muffle body 1, Moreover, it passes through the inside of the muffle body 1 and is carried out from the outlet 1b.

Then, the muffle body 1 is heated to the processing temperature by the upper heater 2 and the lower heater 3, and a processing gas is supplied from the gas inlet 4 into the muffle body 1. When the exhaust gas is filled along the length direction and a gas atmosphere is generated in which the exhaust gas is exhausted from the gas outlet 5 on the inlet 1a side, the work W is carried into the muffle body 1 by the work transfer mechanism 6. Then, the work W is exposed to the gas in the muffle body 1 to be subjected to, for example, a treatment for preventing oxidation.

[0005]

By the way, in the conventional muffle furnace described above, one muffle body 1 handles a single gas, and the work W carries out only one treatment. It is something that cannot be done. for that reason,
When performing a plurality of processes on the work W, it is necessary to generate a gas atmosphere of a number corresponding thereto, so prepare a plurality of muffle main bodies 1 and arrange the muffle main bodies 1 in series in the order of steps. Every time, the work W is sequentially conveyed to each muffle body 1 so that the work W is subjected to a plurality of processes.

However, when a plurality of muffle main bodies 1 are arranged in series, a considerable space is required, and moreover, not only the work transfer mechanism 6 having a length corresponding thereto has to be manufactured, but also the heater power is increased. There was also a problem that it was time-consuming to inspect and maintain the muffle body.

It is an object of the present invention to solve the above-mentioned problems of the prior art and to provide a muffle furnace capable of performing a plurality of treatments on a work by one unit.

[0008]

[Means for Solving the Problems] In order to solve the above problems, the present invention employs the following means. In the present invention, in a muffle furnace provided with a muffle body, a heating means for heating the inside of the muffle body, and a work transfer mechanism for transferring the work to the muffle body, in the muffle body by different types of gas along the transfer direction. Generated and formed in the muffle body with a plurality of contact zones consisting of the gas atmosphere necessary for processing the workpiece,
A plurality of gas barriers for partitioning the upstream part and the downstream part of each contact zone are provided. Further, each of the plurality of contact zones has a plurality of zone gas supply ports for supplying a specific type of gas into the muffle body, and a plurality of zone gas discharge ports for sucking the exhaust gas of the corresponding contact zones. It is characterized by being formed by. The plurality of gas barriers may be installed at an upper portion of the muffle body, and may be formed by gas suction portions that respectively suck an upstream portion and a downstream portion of each contact zone in the muffle body. The plurality of gas barriers, an upstream gas barrier partitioning the upstream part of the contact zone generated on the upstream side in the muffle body, and a downstream gas barrier partitioning the downstream part of the contact zone generated on the downstream side in the muffle body, Of the contact zones generated next to each other in the muffle body, the downstream side of one upstream contact zone and the upstream side of the other downstream contact zone are separated from each other, and an intermediate gas barrier is formed. And A gas suction portion that forms the upstream gas barrier and a gas suction portion that forms the downstream gas barrier.
Barrier inside the muffle body
It is characterized by having a supply port for supplying a gas for use . Each of the plurality of gas barriers has a width substantially similar to a furnace width in the muffle body. And
It is characterized in that it is provided with a partition plate which is erected and attached to each gas barrier in the muffle body. The partition plate has a width substantially similar to the width of the furnace in the muffle body. The partition plate is provided in the muffle body in the vicinity of the upper part of the conveyed work and has a height of ⅕ or more of the height from the upper part of the work to the ceiling.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIG.
~ It demonstrates based on FIG. FIG. 1 is an overall longitudinal sectional view showing an embodiment of a muffle furnace according to the present invention, and FIG. 2 is an enlarged view showing a main part. As shown in FIG. 1, in the muffle furnace 10 of the present embodiment, an upper heater 12a and a lower heater 12b as heating means are arranged on the upper and lower parts of a muffle body 11, and a work W is conveyed to the muffle body 11. It has a work transfer mechanism 13. Work transfer mechanism 1
3 is, for example, belt wheels 14 and 15 and both belt wheels 1
When the work W is supplied to the upstream portion of the belt conveyor 16, the belt conveyor 16 is driven in the arrow z direction by the rotation of the belt wheels 14 and 15. Work W
Can be transported to the downstream side. Therefore, either one of the belt wheels 14 and 15 is connected to a drive source (not shown), but the present invention is not limited to this, and both may be connected to the drive source so as to rotate synchronously. In addition,
The lower heater 12b is provided below the muffle body 11, and its heat is efficiently transmitted to the work W on the belt conveyor 16 via the bottom wall of the muffle body 11 and the belt conveyor 16. Therefore, the belt conveyor 16 is usually formed of a wire mesh, but may be formed of, for example, a wire material formed in a mesh shape.
Although not shown, the muffle body 11 is covered with a cover made of a heat insulating material.

When the belt conveyor 16 is driven when the muffle body 11 is in a gas atmosphere required for processing and is heated by the upper heater 12a and the lower heater 12b, the work on the belt conveyor 16 is driven. W is from the inlet 11a of the muffle body 11 to the muffle body 1
1 is carried in, processed while passing through the inside, and exit 1
Therefore, the muffle body 11 is formed with a plurality of contact zones A to C necessary for processing the work W.

The plurality of contact zones A to C are for generating gas atmospheres by different kinds of gases, and are composed of, for example, a first supply / discharge mechanism 17 to a third supply / discharge mechanism 19. The first supply / discharge mechanism 17 includes an upstream inlet 17a as a zone gas supply port provided at an upper portion of the muffle body 11 near the inlet 11a, and a downstream inlet as a zone gas supply port disposed downstream thereof. 17b and an outlet 17c as a zone gas outlet provided between the inlets 17a and 17b. The upstream inlet 17a and the downstream inlet 17b are connected to a gas supply source (not shown), and the outlet 17c is connected to a suction means (not shown).

The upstream inlet 17a and the downstream inlet 17b
By supplying the gas into the muffle body 11 from both of them and sucking the exhaust gas from the outflow port 17c between them, as shown in FIG. A gas atmosphere consisting of the region between the two'is created, thereby forming the contact zone A.

The second supply / discharge mechanism 18 is provided at an upper part of the muffle body 11 on the downstream side of the first supply / discharge mechanism 17, that is, on an upper part of the center side of the muffle body 11 as an upstream inlet as a zone gas supply port. 18a and a downstream inlet 18b as the inlet for the zone arranged downstream thereof.
And an outlet 18c serving as a zone gas outlet provided between the upstream inlet 18a and the downstream inlet 18b. The upstream inlet 18a and the downstream inlet 18b are connected to a gas supply source (not shown), and the outlet 18c is connected to a suction means (not shown). And the upstream entrance 18
Gas is supplied into the muffle body 11 from both the a and the downstream inlets 18b, and the exhaust gas is sucked from the outflow port 18c between the two, so that the central portion of the muffle body 11 has a central side as shown in FIG. , A gas atmosphere having a range between the arrows b and b'is generated, thereby forming the contact zone B.

The third feeding / discharging mechanism 19 is provided on the downstream side of the second feeding / discharging mechanism 18 of the muffle body 11, that is, on the upper portion of the muffle body 11 on the outlet 11b side, as an upstream inlet 19a as a zone gas supply port. And a downstream inlet 19b,
It comprises an outlet 19c as a zone gas outlet provided between the upstream inlet 19a and the downstream inlet 19b. The upstream inlet 19a and the downstream inlet 19b are also connected to a gas supply source (not shown), and the outlet 19c is also connected to a suction means (not shown). And upstream entrance 1
The gas is supplied into the muffle body 11 from both the inlet 9a and the downstream inlet 19b, and the exhaust gas is sucked from the outlet 19c, so that the arrows c and c are provided on the downstream side of the muffle body 11 as shown in FIG. The contact zone C is formed by generating the gas atmosphere in the range of '.

That is, the first supply / discharge mechanism 17 to the third supply / discharge mechanism 19 generate contact zones A to C each made of a gas atmosphere of a specific type by supplying and discharging different gases, and the respective contact zones. When the work W comes into contact with the gases in A to C, the work W is subjected to different treatments. Therefore, the first supply / discharge mechanism 1
7, the second supply / discharge mechanism 18 and the third supply / discharge mechanism 19 form contact zones A to C having different kinds of gas atmospheres by flowing different exclusive gases into and out of the muffle body 11. To do.

The upstream inlet 17a, the downstream inlet 17b, the upstream inlet 18a, the downstream inlet 18b, the upstream inlet 19a, and the downstream inlet 19b of the first to third supply / discharge mechanisms 17-19 are in the muffle body 11. It has a width substantially similar to the furnace width, and the outlets 17c, 18c, 19c also have the same width.

Further, the muffle furnace 10 is equipped with a gas barrier for partitioning the contact zones A to C so that the gases in the contact zones A to C do not mix with each other. And this gas barrier consists of the 1st-4th gas barriers 21-24.

Among them, the first gas barrier 21 separates the contact zone A from the inlet 11a of the muffle body 11, so that the first gas supply / discharge mechanism 17 is provided at the upper part of the muffle body 11.
It is formed by the gas suction portion 21a provided on the more upstream side. The gas suction part 21a is connected to a suction means (not shown). When the gas is supplied from the upstream inlet 17a of the contact zone A, the first gas barrier 21 is
The exhaust gas is sucked by the gas suction portion 21a as shown by an arrow d in FIGS.
It is formed so as to partition the interior between the contact zone A and the inlet 11a side. Hereinafter, the first gas barrier 21 will be referred to as the upstream gas barrier 21.

Further, the gas suction part 21a provided in the upstream gas barrier 21 has a supply port 21b as a barrier gas supply part upstream thereof. This supply port 2
1b is connected to a gas supply source (not shown), and when the gas is supplied downward in the muffle body 11,
The gas is discharged from the gas suction portion 21a together with the exhaust gas at the upstream portion in the contact zone A, so that the contact zone A
This gas is prevented from leaking from the inlet 11a of the muffle body 11 to the outside. Therefore, the supply port 21b
The discharge pressure and discharge amount of the gas supplied from are appropriately selected according to the pressure in the muffle body 11 and the suction pressure of the gas suction portion 21a so that the gas in the contact zone A can be blocked.

Since the gas supplied from the supply port 21b is arranged near the inlet 11a of the muffle body 11, even if it leaks to the outside from the inlet 11a of the muffle body 11, it has a bad effect. It is preferable to select a type that does not affect the gas in the contact zone A.

The second gas barrier 22 is the muffle body 11
Is formed by a gas suction portion 22a provided between the downstream inlet 17b of the first supply / discharge mechanism 17 and the upstream inlet 18a of the second supply / discharge mechanism 18. This gas suction portion 22a is also connected to a suction means (not shown). Then, when the gas is supplied from the downstream inlet 17b of the contact zone A into the muffle body 11 and the gas is supplied from the inlet 18a of the contact zone B into the muffle body 11, the second gas barrier 22 sucks the exhaust gases of both of them. The portion 22a is formed so that the contact zone A and the contact zone B can be partitioned without being mixed with each other by sucking from both sides as indicated by arrow e in FIG. Hereinafter, the second gas barrier 22 will be referred to as the intermediate gas barrier 22.

The third gas barrier 23 is the muffle body 11
Is formed by the gas suction portion 23a provided between the downstream inlet 18b of the second supply / discharge mechanism 18 and the upstream inlet 19a of the third supply / discharge mechanism 19. This gas suction portion 23a is also connected to a suction means (not shown). When the gas is supplied from the downstream inlet 18b of the contact zone B into the muffle body 11 and the gas is supplied from the upstream inlet 19a of the contact zone C to the third gas barrier 23,
It is formed so that the gas in the contact zone B and the gas in the contact zone C can be partitioned without being mixed with each other by sucking the both exhaust gases by the gas suction portion 23a from both sides as shown by an arrow f in FIG. ing. Below, the third
The gas barrier 23 is referred to as an intermediate gas barrier 23.

The fourth gas barrier 24 has a structure similar to that of the upstream gas barrier 21. That is, the fourth gas barrier 24 is provided on the upper portion of the muffle body 11 with the third gas barrier 24.
Gas suction unit 24a provided on the downstream side of the supply / discharge mechanism 19
Formed by. This gas suction unit 24a is also connected to a suction means (not shown). This downstream gas barrier 2
When the gas is supplied from the downstream inlet 19b of the contact zone C, the gas suction part 24a sucks the exhaust gas as indicated by an arrow g in FIG.
It is formed so as to partition the interior between the contact zone C and the outlet 11b side. Hereinafter, the fourth gas barrier 24 will be referred to as the downstream gas barrier 24.

[0024] In addition, the downstream side of the gas barrier 24, the downstream side moth
A supply port 24b serving as a barrier gas supply unit is provided downstream of the gas suction unit 24a provided in the sub barrier 24. This supply port 24b is also connected to a gas supply source (not shown). This supply port 24b is used for supplying gas to the muffle body 1
1, the gas in the contact zone C is sucked together with the gas in the contact zone C by the gas suction portion 24a as indicated by an arrow g ', so that the gas in the contact zone C leaks from the outlet 11b of the muffle body 11 to the outside. It is designed to prevent

Therefore, the discharge pressure and the discharge amount of the gas supplied from the supply port 24b can shut off the gas in the contact zone C like the gas supplied from the supply port 21b.
It is appropriately selected according to the pressure inside the muffle body 11 and the suction pressure of the gas suction portion 24a. The gas supplied from the supply port 24b is the outlet 1 of the muffle body 11.
As it is located near 1b, its exit 11
Even if it leaks to the outside from b, it is preferable to select a type that does not have an adverse effect and that does not affect the gas in the contact zone C.

Further, each of the gas barriers 21 to 24 corresponds to the furnace width of the first to third supply / discharge mechanisms 17 to 19 and has a width substantially similar to the furnace width in the muffle body 11.

Since the muffle furnace 10 of this embodiment is constructed as described above, first, when processing the work W, the inside of the muffle body 11 is heated by the upper heater 12a and the lower heater 12b as heating means. ,
The gas supply source and suction means connected to the first to third supply / discharge mechanisms 17 to 19 are driven, and the gas suction unit 2
The following gas atmosphere is generated in the muffle body 11 by driving the suction means connected to the la, 22a, 23a, and 24a.

That is, in the muffle body 11, the first
A desired type of gas is supplied from the upstream inlet 17a and the downstream inlet 17b of the supply / discharge mechanism 17 and is sucked from the outlet 17c between the upstream inlet 17a and the downstream inlet 17b, so that the supplied gas is directed downward. After the work W is filled in the conveyance path, the work W is sucked so as to attract each other and discharged from the outlet 17c, thereby forming a gas path extending in the directions of arrows a and a ′ shown in FIGS. 1 and 2. A contact zone A having a gas atmosphere in the range between a and a'is created.

Also, the second supply / discharge mechanism 18 and the third supply / discharge mechanism 19 have the same operation as the first supply / discharge mechanism 17, and the upstream inlet 18a, the downstream inlet 18b, and the outlet 18c of the second supply / discharge mechanism 18 are used. , The contact zone B forming a gas atmosphere in the range between the arrows b and b ′ is generated, while the range between the arrows c and c ′ by the upstream inlet 19a, the downstream inlet 19b, and the outlet 19c of the third supply / discharge mechanism 19. The third contact zone C forming the gas atmosphere is generated.

At this time, the gas suction portions 21a, 22a, 23
Since the suction means connected to a and 24a are driven, these form gas barriers 21 to 24 for partitioning the upstream and downstream portions of the contact zones A to C, respectively. That is, when the contact zone A is formed in the muffle body 11, the gas suction portion 21a sucks the exhaust gas in the contact zone A as shown by the arrow d to form the upstream gas barrier 21 in that portion. The upstream gas barrier 21 partitions the upstream portion of the contact zone A.

Moreover, the gas suction part 21a has a supply port 21b as a zone gas supply part on the upstream side thereof, and functions as a shielding wall of the contact zone A by supplying gas downward from the supply port 21b. Then, when the gas is sucked together with the exhaust gas by the gas suction portion 21a as shown by the arrow d ', it is possible to prevent the gas in the contact zone A from leaking to the outside from the inlet 11a of the muffle body 11.

On the other hand, the gas suction portion 22a has a contact zone A
By sucking the exhaust gas of the downstream portion of the contact zone B as shown by the arrow e and sucking the exhaust gas of the upstream portion of the contact zone B supplied from the upstream inlet 18a, the intermediate gas barrier 2
2 is formed, and the intermediate side gas barrier 22 partitions the downstream portion of the contact zone A from the upstream portion of the contact zone B.

Further, the gas suction portion 23a has a contact zone B
At the same time as sucking the exhaust gas in the downstream part of
By sucking the exhaust gas in the upstream portion of the contact zone C as well, an intermediate gas barrier 23 is formed there, and the intermediate gas barrier 23 partitions the downstream portion of the contact zone B from the upstream portion of the contact zone C. .

Further, the gas suction portion 24a sucks the exhaust gas in the downstream portion of the contact zone C as shown by the arrow g, and the downstream gas barrier 24 is formed there. The downstream part can be partitioned. Moreover, the gas suction part 24a has a supply port 24b as a zone gas supply part on the downstream side, and by supplying gas downward from this supply port 24b, it functions as a shielding wall of the contact zone C, and The gas is introduced together with the exhaust gas in the contact zone C by the gas suction unit 24a into an arrow g '.
As described above, the gas in the contact zone C can be prevented from leaking to the outside from the outlet 11b of the muffle body 11.

In this embodiment, as described above, the contact zones A to C are formed in the muffle body 11 by the first to third supply / discharge mechanisms 17 to 19, respectively, and the gas suction portions 21a, 22a, 23a, and The upstream gas barrier 21, the intermediate gas barriers 22 and 23, and the downstream gas barrier 24 formed by 24a can partition the upstream and downstream portions of the contact zones A to C, respectively, and thus the contact zones A to C. Each gas of the above does not mix with the adjacent gas. Moreover, by supplying the gas from the supply port 21b, it is possible to prevent the exhaust gas in the contact zone A from leaking out from the inlet 11a of the muffle body 11, and by supplying the gas from the supply port 24b, the contact zone Exhaust gas of C is the muffle body 1
It is possible to prevent the leakage from the first outlet 11b.

Therefore, when the work W is transferred to the muffle body 11 by the work transfer mechanism 13 while the contact zones A to C are formed on the muffle body 11, the work W is transferred to the contact zones A to C. By sequentially passing through C, different treatments are sequentially performed, and a plurality of treatments can be accurately performed in one muffle furnace 10.

As a result, when the work W in the muffle furnace 10 is subjected to a plurality of treatments, it is not necessary to connect a plurality of muffle furnaces in series as in the prior art, so that the space is greatly reduced. Not only is it unnecessary to manufacture a long dedicated work transfer mechanism, but also the power of the heating means can be greatly reduced.
Furthermore, maintenance such as maintenance and inspection becomes easy.

Further, in this embodiment, the gas suction portion 21a has the supply port 21b, and the gas suction portion 24 is provided.
Since a has the supply port 24b, when a gas that causes a problem of leakage is used, it is possible to reliably avoid the gas leakage, and it is possible to improve safety.

FIG. 3 shows a second embodiment of the muffle furnace according to the present invention. In the above-described embodiment, an example is shown in which the gas in the contact zone A and the contact zone C is prevented from leaking to the outside of the muffle body 11, but in the present embodiment, the gas in the contact zone A and the contact zone C is slightly different. It is applied when a gas that does not have a bad influence even if it leaks is used. That is, in the case of this embodiment, as shown in FIG. 3, the upstream gas suction unit 21a sucks only the exhaust gas from the contact zone A without using the supply port 21b of the above-described embodiment. There is. In this case, the gas suction unit 24a on the downstream side is also the supply port 2 of the above-described embodiment.
4b is not used, and only the exhaust gas from the contact zone C is sucked.

In this embodiment, when the contact zone A is generated in the muffle body 11 by the first supply / discharge mechanism 17, the gas suction portion 21a sucks the exhaust gas in the contact zone A. The upstream gas barrier 21 formed by the portion 21a leaks a part of the exhaust gas in the contact zone A from the inlet 11a of the muffle body 11 to the outside, so that external air enters the muffle body 11 from the inlet 11a. Can be prevented.

Further, since the gas suction section 24a is also constructed in the same manner as described above, when the exhaust gas in the contact zone C is sucked from the gas suction section 24a, a part of the exhaust gas in the contact zone C is partially absorbed in the gas suction section. The outlet 1 of the muffle body 11 passes through the downstream gas barrier 24 formed by 24a.
It is possible to prevent external air from entering the muffle body 11 through the outlet 11b due to the leaked exhaust gas from the 1b.

Therefore, according to this embodiment, the upstream gas barrier 21 leaks a small amount of gas in the contact zone A from the inlet 11a, and the downstream gas barrier 24 leaks a small amount of gas in the contact zone C from the outlet 11b. Since the external air does not enter the muffle body 11, the influence of the external air can be prevented and the processing of the work W can be stabilized. The gas that has no effect even if it leaks to some extent is, for example, nitrogen gas. Moreover, the upstream and downstream gas barriers 21 and 24 are connected to the gas suction unit 21.
Since it is formed only by a and 24a, the configuration can be simplified by that much as compared with the one embodiment.

The suction force of the gas suction portions 21a and 24a is the pressure of the gas atmosphere in the contact zones A and C, and the upstream inlet 1
7a, 19a and the gas supply pressure of the downstream inlets 17b, 19b,
It is also possible to adjust the amount of gas to be leaked out by selecting it according to the suction pressure of the outlets 17c, 19c and the like, and changing its size.

4 and 5 show other embodiments according to the present invention, respectively. The embodiment shown in FIG.
Which is applied to the embodiment of FIG.
A partition plate 25 is erected inside the upstream gas barrier 21.

Then, in the muffle body 11, the exhaust gas in the contact zone A is sucked by the upstream gas barrier 21. At that time, the sucked exhaust gas is raised along the partition plate 25 to form a suction flow, By promoting the suction action on the side gas barrier 21, the gas exhausted from the contact zone A is prevented from accidentally leaking to the outside from the inlet 11a, and the function as a gas barrier is enhanced.

Therefore, the partition plate 25 is the muffle body 1
It is attached below the gas suction part 21a in
It has a desired height L and width so as to promote the discharge of gas from the contact zone A, and is provided, for example, near the upper part of the work W, and from the top surface of the work W to the ceiling 11 of the muffle body 11.
If the height up to c is H, it is preferable that the height L is H / 5 or more, and the width is almost the same as the furnace width in the muffle body 11. The partition plate 25 is preferably made of a material that has corrosion resistance to the gas used in the contact zone A, heating, etc. and that does not affect the work W.

In this example, the partition plate 25 is arranged only on the inlet 11a side in the muffle body 11, but it is more effective if it is also arranged on the downstream gas barrier 24 on the outlet 11b side. Yes, and also the middle gas barrier 2
Further effects can be obtained by providing 2 and 23 as well. That is, although not shown, the intermediate gas barrier 2
When a partition plate is provided on 2, 23, the muffle body 11
In the inside, the partition plate is provided with the gas suction portions 22a and 23a.
Stand underneath and attach each. The partition plate for the intermediate gas barrier 22 promotes the suction action between the exhaust gas on the downstream side of the contact zone A and the exhaust gas on the upstream side of the contact zone B, while the partition plate for the intermediate gas barrier 23 operates in the contact zone B. By promoting the suction action between the exhaust gas on the downstream side and the exhaust gas on the upstream side of the contact zone C, it is possible to reliably prevent the gases in the adjacent contact zones from intermingling with each other, and to clearly partition the contact zones. You can

The embodiment shown in FIG. 5 is applied to a gas suction portion 21a having a supply port 21b, and in this case as well, the partition plate 25 is provided on the upstream gas barrier 21 in the muffle body 11. It is installed upright. The height L of the partition plate 25 is the dimension described above.

According to this embodiment, the exhaust gas in the contact zone A is sucked by the upstream gas barrier 21, and
The gas from the supply port 21b is also sucked, but at that time, both gases are sucked along the partition plate 25, and since the partition plate 25 is present, the pressure on the contact zone A side is made high by the Werneuy equation. Therefore, the gas in the contact zone A can be reliably prevented from leaking to the inlet 11a side.

Therefore, the gas in the contact zone A is at the inlet 1
Since it is possible to reliably prevent the leakage of the gas from the muffle body 11 from the la, it is possible to enhance the safety against the leakage of the processing gas. In the present example, such a partition plate 25 is provided only on the upstream gas barrier 21 in the muffle body 11, but it is better to provide not only the downstream gas barrier 24 but also the intermediate gas barriers 22 and 23. It is effective.

In the illustrated embodiment, an example in which three different kinds of gases are used and the contact zones A to C which form different gas atmospheres from each other are provided is shown.
In the present invention, the number is not limited, and the point is that at least two contact zones are provided.

[0052]

As described above, according to the present invention, each contact zone is formed in the muffle body, and
Multiple gas barriers can be used to partition the upstream and downstream parts of each contact zone, and multiple treatments can be performed accurately with one muffle furnace.As a result, multiple muffle furnaces can be connected in series as in the prior art. Not only is it unnecessary to connect, it is not only a great reduction in space, it is not necessary to manufacture a long dedicated work transfer mechanism,
The electric power of the heating means can be greatly reduced, and maintenance such as maintenance and inspection can be facilitated, which is extremely effective in practice.

[Brief description of drawings]

FIG. 1 is an overall vertical sectional view showing an embodiment of a muffle furnace according to the present invention.

FIG. 2 is also an enlarged view showing a main part of the muffle furnace.

FIG. 3 is an enlarged view of an essential part showing a second embodiment of the muffle furnace according to the present invention.

FIG. 4 is an explanatory view of an enlarged main part showing another embodiment of the muffle furnace according to the present invention.

FIG. 5 is an explanatory view of an enlarged main part showing still another embodiment of the muffle furnace according to the present invention.

FIG. 6 is an overall vertical sectional view showing an example of a conventional muffle furnace.

[Explanation of symbols]

10 muffle furnace 11 muffle body 11a entrance 11b exit 11c ceiling 12a Upper heater as heating means 12b Lower heater as heating means 13 Work transfer mechanism 14,15 Belt car 16 belt conveyor 17 First supply / discharge mechanism 17a upstream inlet as zone gas supply port 17b Downstream inlet as zone gas supply port 17c Outlet as a gas outlet for the zone 18 Second supply / discharge mechanism 18a upstream inlet as zone gas supply port 18b Downstream inlet as zone gas supply port 18c Outlet as zone gas outlet 19 Third supply / discharge mechanism 19a upstream inlet as zone gas supply port 19b Downstream inlet as zone gas supply port Outlet as a 19c zone gas outlet 21 Upstream gas barrier (first gas barrier) 21a Gas suction section 21b Supply port 22 Middle gas barrier (second gas barrier) 22a Gas suction section 23 Intermediate gas barrier (third gas barrier) 23a Gas suction section 24 Downstream gas barrier (4th gas barrier) 24a gas suction section 24b supply port 25 dividers A contact zone B contact zone C contact zone L Partition plate height W work

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Richard C. Ali United States California 95076 Watsonville Westridge Drive 200 Sierra Thermo Productions Furnace Incorporated (72) Inventor Thomas Earl. Stewart United States California 95076 Watsonville Westridge Drive 200 Sierra Thermo Productions in Furnace Incorporated (56) References JP-A-4-236398 (JP, A) JP-A-10-237541 (JP, A) JP-A 52-114567 (JP, A) JP-A-6-347175 (JP, A) JP-A-2-254289 (JP, A) JP-A-6-82162 (JP, A) Actual Kaihei 3-89390 (JP, U) Japanese Patent Publication No. 40-10421 (JP, B1) (58) Fields investigated (Int.Cl. ⁷ , DB name) F27B 9/04 F27B 5/10 F27D 7/06

Claims (9)

(57) [Claims] 1. A muffle furnace equipped with a muffle body, heating means for heating the inside of the muffle body, and a work transfer mechanism for transferring a work to the muffle body. And a plurality of gas barriers that are formed in the muffle body and partition the upstream and downstream portions of each contact zone. And a muffle furnace. 2. Each of the plurality of contact zones has a plurality of zone gas supply ports for supplying a specific type of gas into the muffle body, and a plurality of zone gas discharge ports for sucking the exhaust gas of the corresponding contact zones. The muffle furnace according to claim 1, wherein the muffle furnace is formed by a supply / discharge mechanism. 3. The plurality of gas barriers are respectively installed on an upper portion of the muffle body, and are formed by gas suction portions respectively sucking an upstream portion and a downstream portion of each contact zone in the muffle body. The muffle furnace according to claim 1. 4. The plurality of gas barriers partition an upstream gas barrier partitioning an upstream part of a contact zone generated upstream of the muffle body and a downstream part of a contact zone generated downstream of the muffle body. A downstream gas barrier, and an intermediate gas barrier that partitions both the downstream part of one upstream contact zone and the other downstream contact zone of the contact zones generated next to each other in the muffle body. The muffle furnace according to any one of claims 1 to 3, wherein the muffle furnace comprises: 5. A gas suction part forming the upstream gas barrier and a gas suction part forming the downstream gas barrier.
Supplying a barrier gas into the muffle body
Muffle furnace according to claim 4, characterized in that it has a supply port. 6. The muffle furnace of claim 3, wherein each of the plurality of gas barriers has a width substantially similar to the width of the furnace inside the muffle body. 7. The muffle furnace according to any one of claims 1 to 6, further comprising a partition plate which is erected and attached to each gas barrier in the muffle body. 8. The muffle furnace according to claim 7, wherein the partition plate has a width substantially similar to the width of the furnace in the muffle body. 9. The partition plate is provided in the muffle body in the vicinity of an upper portion of a conveyed work, and has a height of ⅕ or more of a height from an upper portion of the work to a ceiling. The muffle furnace according to any one of claims 7 and 8.