JPH0953887A - Vacuum/gas ambient heat-treatment furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a vacuum/gas atmosphere heat-treatment furnace which minimizes the amount of emitted gas in a process of heat treatment. SOLUTION: In a vacuum/gas atmosphere heat-treatment furnace, for example, only a metal-made tray may be carried out to the open air out of components to be inserted into a preheating chamber 11, and the others such as post 45, and insulation materials 45 and 46 are always kept in a conveying chamber 5 so that no water content may be absorbed. The other tray receiving mount 32 and conveying mount 33, which are carried out in the open air is made of metal, including the tray 31. The case is same with a degasing chamber and a sintering chamber 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat treatment furnace for heat treating an object to be processed in vacuum or in a gas atmosphere.

[0002]

2. Description of the Related Art An object to be treated such as a sintered part is sequentially inserted into a preheating chamber, a degassing chamber, a sintering chamber, etc. and heat treated in a vacuum or in a predetermined gas atmosphere. It

(First Conventional Example) FIG. 4 is a vertical sectional view showing the whole of a conventional roller conveyor type vacuum / gas atmosphere heat treatment furnace 100, and a preparation chamber 110 having an inlet 107 and an outlet 108, respectively. A degassing chamber 120, a sintering chamber 130, and a cooling chamber 140 similar to this are connected to each other, and each chamber has a vacuum evacuation system, and an inert gas such as argon or nitrogen can be introduced. There is. Further, the cooling chamber 140 is provided with a fan 142 driven by an electric motor 141 and a cooler 143. The object 101 to be processed is placed on the transfer table 103 together with the tray 102, and is transferred from the left side to the right side in FIG. 4 on the rollers 104 provided in the respective chambers. The tray 102, the carrier 103, and the roller 104 are made of heat-resistant carbon or CCM (commercial name of carbon fiber-based molded product) which is a carbon-based material. Further, an air cylinder 105 is provided below the preparation chamber 110, the degassing chamber 120, and the sintering chamber 130. During the heat treatment, the object 101 to be processed is inserted into the tray 102, the carrier 103, and the bottom surface of each chamber. Air cylinder 1
It is lifted by the piston rod 106 of 05 and is separated upward from the roller 104, and the roller 104 is constantly rotated to prevent thermal deformation. Alternatively, the object to be processed is placed on the roller ignoring the withstand load and thermal deformation of the roller.

In the roller conveyor type vacuum / gas atmosphere heat treatment furnace 100 of the first conventional example, since the roller 104 is in the heating zone, the roller 104 is heated to a high temperature, which is uneconomical in terms of thermal energy. In addition, since the carrier 103 of the same material is carried on the roller 104, both wear is large. Also, the tray 102 and the carrier 10
3 is carried out from the cooling chamber 140 into the atmosphere, and then the preparation chamber 1
Since it is in contact with the atmosphere until it is loaded into the container 10, and the material is carbon or carbon-based CCM, it absorbs moisture in the atmosphere and releases a large amount of gas when loaded into the preparation chamber 110 and heated. Therefore, a large-capacity vacuum exhaust system is required and the heat treatment of the object 101 is adversely affected. Further, the heat treatment is easily affected by humidity in the atmosphere.

(Second Conventional Example) Unlike the roller conveyor type, a method of providing a local heating chamber to separate the roller from the heating zone is disclosed in Japanese Utility Model Publication No. 4-24397 and Japanese Patent Publication No. 5-1747.
No. 2 and Japanese Patent Publication No. 6-33940. For example, in an example of "a vacuum furnace having a local heating chamber" according to Japanese Patent Publication No. 6-33940, a dewaxing chamber 204 as shown in Fig. 5 which constitutes a part of the vacuum furnace is shown. That is, the local heating chamber 230 is attached to the fixture 231.
Is attached to the vacuum container 202, and the lower surface thereof is open with a sufficient space inside. The local heating chamber 230 is formed of a heat insulating material such as graphite, and is formed in a felt shape to have air permeability. A heating wire 232 is installed in the local heating chamber 230.

A partition container 233 is arranged in the local heating chamber 230, and has a space sufficient to hold the object 256 to be processed therein and the lower surface is open. Compartment container 2
33 is formed of a material that substantially blocks the flow of gas.
For example, when the temperature in the local heating chamber 230 is up to about 1150 ° C., a well-known heat-resistant metal material is used,
In the case of more than that, ceramics or carbon is used. The partition container 233 has an extending portion 233a extending downward from the local heating chamber 230, and is detachably fixed to a receiving piece 235 fixed to the vacuum container 202 by a mounting piece 234. In the partition container 233, a receiving member 23 formed of an insulating material in the shape of an inner collar is formed.
6 is attached, and a flange 237 is circumferentially fixed to the lower end of the extending portion 233a. Further, ascending means 38 is provided below the local heating chamber 230,
It is constituted by a piston rod of a cylinder attached to the bottom atmosphere side of the vacuum container 202, and a receiving seat 241 is fixed to the tip. The raising means 38 raises and lowers the table 250 that has been conveyed on the conveying roller 220.

The object to be processed 256 is placed on the table 250.
A partition lid 251 is attached to the table 250 and is made of a material that substantially blocks the flow of gas. Further, the area thereof is large enough to close the open portion of the lower surface of the partitioned container 233, and a sealing ring for closely contacting the flange 237 is provided on the periphery. Compartment lid 251
A pillar 252 made of heat-resistant material is erected from the upper surface of the
The upper end is provided with a receiving bar 253 for supporting the object to be processed 256. A blocking plate 254 made of a heat-resistant material having air permeability is attached to an intermediate portion of the support column 252, and a heat insulating material 255 similar to the local heating chamber 230 is provided on an upper surface thereof. The closing plate 254 with the heat insulating material 255 is configured such that the upper surface of the peripheral edge thereof can abut the lower surface of the receiving member 236 so as to thermally seal the local heating chamber 230.

To explain the operation, the table 250 which has reached the transport roller 220 of the dewaxing chamber 204 in the vacuum state is lifted by the receiving seat 241 of the ascending means 238. Object to be processed 2 on receiving bar 253
As shown in FIG. 5, 56 is located in the existing space in the partitioned container 233 in the local heating chamber 230. Further, the closing plate 254 closes the open portion of the lower surface of the local heating chamber 230, and the partition lid 251 closes the open portion of the lower surface of the partitioned container 233.

After that, the heating wire 233 is energized, and the object 256 to be processed is heated at a predetermined temperature for a predetermined time by the radiant heat emitted from the heating wire 233. When the heating is completed, the raising means 238 is lowered and the table 250 on which the object 256 to be processed is placed is placed on the conveying roller 220 from the solid line position as shown by the alternate long and short dash line. Transferred to the room.

In the second conventional example, the transport roller 220 is used.
Since the heating roller is separated from the heating zone, the transport roller 220 does not need a countermeasure against high temperature, and energy is improved because unnecessary portions are not heated. However, in terms of adsorption of moisture or the like which is an obstacle to heat treatment. There are still problems. That is, the base 250 that constitutes the carrier of the object to be processed 256 is made of carbon or a carbon-based material that is the same material as the transport roller 220, and the support 2 that is another constituent material.
52, the receiving bar 253, and the closing plate 254 are also often made of a carbon-based material as a heat-resistant material. Also, the closing plate 25
As the heat insulating material 255 on the upper surface of No. 4, the same graphite as that of the local heating chamber 230 is used. Since these carbon-based materials easily adsorb a large amount of water when they are discharged into the atmosphere, they release a large amount of gas when they are used again, and a large-capacity vacuum exhaust system is required. Furthermore, the most decisive weakness is the local heating room 2
Part of the heat insulating material 255, the receiving bar 253, and the support column 252 inserted into 30 is carried out into the atmosphere as a carrier, and since the heat insulating material 255 adsorbs moisture in particular, it is heated again in the local heating chamber 230 under vacuum. When released, gas is released and the quality of heat treatment of the object to be processed 256 is extremely deteriorated.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems and has a small amount of gas released during heat treatment in a vacuum or a gas atmosphere, and does not require a large-capacity vacuum exhaust system. An object is to provide a heat treatment furnace. It is another object of the present invention to provide a vacuum / gas atmosphere heat treatment furnace capable of performing high-quality heat treatment on an object to be processed.

[0012]

[Means for Solving the Problems] The above object is to provide an inlet for an object to be processed at one end and an outlet for the other end, and to internally connect the object to be processed from the inlet to the outlet. A horizontal transfer chamber having a plurality of compartments defined by opening and closing doors and a single or a plurality of heat treatment chambers provided at the top of the compartments through insertion openings, respectively. Vacuum / gas atmosphere consisting of an elevating mechanism which is provided below each of the heat treatment chambers and which raises the object to be processed and is inserted into the heat treatment chamber through the insertion opening and which closes the insertion opening. In the heat treatment furnace, the object to be processed is placed together with a metal tray on a tray pedestal having a metal opening that is placed on top of an opening of a metal carrier that has an opening through which the elevating mechanism can be inserted. Placed in the transport The lift mechanism supports a metal lift table that is lifted up and down in the opening of the transfer table, and the tray that is erected on the lift table so as to be able to move up and down in the opening of the tray receiving table. And a heat insulating material provided on the tray side of the elevating table, and the column integral with the elevating table is elevated to support the object to be processed together with the tray and insert the object. The vacuum / gas atmosphere heat treatment furnace is characterized in that, when it is inserted into the heat treatment chamber from the use opening, the elevating table closes the insertion opening together with the tray support that accompanies the ascending operation.

[0013]

[Operation] A carrier that is carried out into the atmosphere after the completion of heat treatment,
Both the tray pedestal and tray are made of metal, the adsorption of water is small compared to carbon-based materials, and among the components inserted into the heat treatment chamber together with the object to be treated, the atmosphere after the heat treatment is completed. Only the tray made of metal is carried into the inside, and the columns and the heat insulating material that easily adsorbs water are always in the transfer chamber, and since they are not carried out into the atmosphere, they do not adsorb water and do not serve as a gas emission source. Therefore, high quality heat treatment is possible.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A vacuum / gas atmosphere heat treatment furnace according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a side view of a vacuum / gas atmosphere heat treatment furnace 10, in which one end of a transfer chamber 5 is provided with an inlet 6 for an object H to be processed.
A carry-out port 9 is provided at the other end. A preheating chamber 1, a degassing chamber 2 and a sintering chamber 3 are provided in the upper part, and the transfer chamber 5 is a preheating chamber 1
Is defined by a transfer chamber 5 ₁ , a transfer chamber 5 ₂ and a cooling chamber 4, which are airtightly partitioned by opening / closing doors 7 and 8 at an intermediate position between the degassing chamber 2 and the degassing chamber 2. . Further, the preheating chamber 1, the degassing chamber 2, the sintering chamber 3, and the transfer chamber 5
₁ , the transfer chamber 5 ₂ and the cooling chamber 4 are respectively connected to a vacuum exhaust system, and argon gas (Ar) and nitrogen gas (N ₂ ) are introduced into the preheating chamber 1, the transfer chamber 5 ₁ and the cooling chamber 4. A pipe is connected to the degassing chamber 2 and the sintering chamber 3, and an argon gas introducing pipe is connected to the degassing chamber 2 and the sintering chamber 3. Further, the transfer chamber 5 ₁ having the carry-in port 6 and the cooling chamber 4 having the carry-out port 9 can introduce the atmosphere even though they are not shown.

Chain belts 22 ₁ and 2 are provided in the transfer chamber 5.
2 ₂ , 22 ₃ and 22 ₄ are connected to each other and convey the object H to be processed which is carried in from the carry-in port 6. Furthermore, the preheating chamber 1,
A chain belt 22 is provided below the degassing chamber 2 and the sintering chamber 3.
Air cylinders 41 ₁ , 41 ₂ , 41 ₃ are provided on ₁ , 22, ₂ and 22 ₃ for lifting the stopped workpiece H upward. Since the preheating chamber 1, the degassing chamber 2 and the sintering chamber 3 have substantially the same structure, the preheating chamber 1 is shown in FIGS. 2 and 3. That is, FIG. 2 is a vertical sectional view of the preheating chamber 1, and FIG. 3 is a sectional view taken along line [3]-[3] in FIG.

The preheating chamber 1 is installed on the opening 5h provided at the top of the transfer chamber 5, and the bottom plate 13a of the preheating chamber 1 has an opening communicating with the transfer chamber 5. In the preheating chamber 1, a heat treatment chamber 11 for accommodating an object to be treated H is defined by a heat insulating material 12. The top end plate of the preheating chamber 1 and the ceiling of the heat insulating material 12 are removable, which facilitates internal inspection and repair. The lower end of the heat insulating material 12 is in contact with the inner circumference of the bottom plate 13a, and an opening 13 for inserting the object H to be processed is formed. Further, an electric heater 14 for heating is attached in the heat treatment chamber 11 to heat it to a predetermined temperature.

Referring also to FIG. 3, the electric motor 2 is provided in the transfer chamber 5.
The chain belt 22 driven by 1 is wound around the drive sprocket 23 and the driven sprocket 24,
The processing object H on the tray 31 stacked on the transfer table 33 is transferred via the tray receiving table 32. That is, the carrier table 33 is in the shape of a square plate having a circular opening 34 in the center, and the outer peripheral portion of the annular tray receiver 32 is placed on the opening 34 of the carrier table 33 so that the tray is The outer peripheral portion of the tray 31 on which the object to be processed H is placed is placed on the inner peripheral portion of the pedestal 32. Then, the transport table 33 is transported by being engaged with the chain belt 22 at both left and right ends in the transport direction. Guide plates 25 are installed on both sides of the carrier 33. Further, when the carrier table 33 stops immediately below the preheating chamber 1, the stopper 26 for fixing the position is provided with a stopper 26.
Are provided in front of and behind, and are rotated by a drive source 27 to take a released position in a lying posture shown by a chain line and a stop position in a standing posture shown by a solid line. The roll 28 provided on the downstream side of the chain belt 22 assists the feeding of the carrier 33 into the degassing chamber 2.

An air cylinder 41 as an elevating device is installed below the preheating chamber 1 and on the outer bottom surface of the transfer chamber 5.
The piston rod 42 penetrates into the transfer chamber 5 through the seal member 43, and an elevating table 44 is attached to the tip. The elevating table 44 has a surface shape that allows the circular opening 34 of the transfer table 33 to be inserted therethrough.
Four metal columns 45 for supporting the tray 31 on which the trays are placed are erected so as to be inserted through the ring of the tray receiving stand 32. Further, the same heat insulating materials 46 and 47 as the heat insulating material 12 that defines the heat treatment chamber 11 are attached to the upper surface of the lifting table 44 and the intermediate portion between the columns 45.

When the lift base 44 is lifted by the air cylinder 41, the lift base 44 is inserted through the circular opening 34 of the carrier base 33 and then lifted together with the tray mount 32, and the support column 45 is moved to the tray mount. Although it rises by being inserted through the ring of 32, when the object H to be processed is inserted into the heat treatment chamber 11, the elevating table 44 closes the opening 13 together with the tray receiving table 32, and the heat insulating materials 46 and 47 perform the heat treatment. Together with the heat insulating material 12 in the chamber 11, it covers the periphery of the object to be processed H and heats the opening 13. At this time, a metal contact or a sealing material 48 is provided between the elevating table 44 and the tray support 32, and a metal contact or a sealing material 49 is provided between the tray support 32 and the bottom plate of the preheating chamber 1 so as to be airtight. The bottom plate of the preheating chamber 1 that is sealed is provided with a cooling passage 19 to cool the sealed portion. Then, in a sealed state, the preheating chamber 1 is exhausted to a pressure of 10 ⁻⁵ Torr by a vacuum exhaust system (not shown).

The degassing chamber 2 and the sintering chamber 3 following the preheating chamber 1 are heated to a temperature of about 1150 ° C. under a reduced pressure of 200 to 10 ^-2 Torr, but as described above, the preheating chamber 1 is basically used.
Since they are configured in the same manner as, the description thereof will be omitted. The cooling chamber 4 is configured such that the fan 52 is rotated by the electric motor 51, the pressurized gas inside is cooled by the heat exchanger 53, and is sprayed to the object to be processed H for cooling.

The vacuum / gas atmosphere heat treatment furnace 10 of the embodiment is constructed as described above, and its operation will be described below.

Referring to FIG. 1, the vacuum / gas atmosphere heat treatment furnace 10 is operated with the preheating chamber 1 and the transfer chamber 5 _{1 in} a state where the carry-in inlet 6 is opened and the opening / closing doors 7 and 8 and the carry-out outlet 9 are closed. Is set to the atmospheric pressure, and the degassing chamber 2, the sintering chamber 3, the transfer chamber 5 ₂ and the cooling chamber 4 thereunder are evacuated, and the operation is started. The carrier 33 on which the processing object H is loaded is carried into the carrier chamber 5 ₁ from the carrier port 6, the carrier port 6 is closed, and the carrier chamber 5 ₁ and the preheating chamber 1 are evacuated. At the same time, referring to FIG. 2 and FIG.
3 is engaged with the chain belt 22 ₁ to reach directly below the preheating chamber 1 and is stopped while being sandwiched by the guide plates 25, and the stopper 26 is set up and fixed at the position shown by the one-dot chain line in FIG. .

In this state, the air cylinder 41 is actuated, the piston rod 42 rises, and the up-and-down stand 44 rises together with the upright pillar 45, and the pillar 45 is inserted through the ring of the tray holder 32. , Abut on the bottom surface of the tray 31 and lift it. After this, the elevating table 44 is inserted through the circular opening 34 of the carrying table 33, lifts the tray receiving table 32 and is lifted, and the tray receiving table 32 and the elevating table 44 are lifted.
Are closed by closing the opening 13 of the preheating chamber 1. In this way, the preheating chamber 1 is sealed, and the object H to be processed placed on the tray 31 is inserted into the heat treatment chamber 11.

After that, the electric heater 14 is energized and heated to, for example, a vacuum degree of 10 ⁻⁵ Torr and a temperature of 800 ° C. After a lapse of a predetermined time, the lift table 44 is lowered by the air cylinder 41, and the tray 31 on which the workpiece H is placed is placed.
Is loaded again on the transport table 33 together with the tray receiving table 32. Then, the opening / closing door 7 of the transfer chamber 5 ₁ is opened, the stopper 26 is released and the chain belt 22 ₁ is driven,
The transfer table 33 loaded with the object to be processed H, is conveyed toward the next conveyance chamber 5 _2.

[0026] When the transport platform 33 is closed and the door 7 is carried into the transfer chamber 5 _2, is stopped immediately below the degassing chamber 2 by the chain belt ₂₂₂ is positioned, the elevation frame 44 by an air cylinder 41 _{2 2} is raised, and as in the case of the preheating chamber 1, the object to be processed H is kept in the heat treatment chamber 11 of the degassing chamber 2 under a vacuum of, for example, 10 ^-2 Torr for a predetermined time,
It is heated to 1000 ° C. and degassed. Similarly, in the sintering chamber 3, the workpiece H is sintered at 1150 ° C. for a predetermined time under a vacuum of 10 ⁻² Torr, for example. Then, when the sintering is completed, the opening / closing door 8 is opened, the transfer table 33 on which the object to be processed H is loaded is transferred from the chain belt 22 ₃ to the chain belt 22 ₄ and transferred to the cooling chamber 4, and the opening / closing door 8 is closed. To be After that, the cooling gas is, for example, 1.9k.
Introduced at a pressure of g / cm ² G, fan 52 and cooler 5
By the operation of 3, the processing object H is cooled. When cooled to a predetermined temperature, the cooling chamber 4 is set to the atmospheric pressure, and the carry-out port 9
Is opened, and the object to be processed H is conveyed by the carrier table 33 and the tray tray 3
2. It is carried out into the atmosphere together with the tray 31.

That is, in the vacuum / gas atmosphere heat treatment path 10 of the embodiment, referring to FIG. 2, among the constituent members inserted into the heat treatment chamber 11, they are taken out of the transfer chamber 5 and contacted with the atmosphere for a long time. Only the metal tray 31 having a small amount of water adsorption is supported, and the support column 45 supporting the tray 31 is provided.
The heat insulating materials 46 and 47 that easily adsorb moisture do not adsorb moisture because they are always in the transfer chamber 5 and are not carried out to the atmosphere. Therefore, they are inserted into the heat treatment chamber 11 together with the object H to be processed and decompressed. Emits almost no gas when heated below.
Also, in addition to the tray 31, the carrier 33, which is carried out from the carrier chamber 5 to the atmosphere, and the tray receiver 32 are all made of metal to suppress the adsorption of water as much as possible, and therefore, most of the gas is not generated during the heat treatment. Since it is not released, the quality of the heat treatment of the object H to be processed is significantly improved. Furthermore, the roller 10 of the transport mechanism
Compared to the first conventional example in which 4 is present in the heating zone, the temperature does not rise in the transfer mechanism of the embodiment because it is isolated from the heat treatment chamber 11, so that it is less likely to wear and the transfer accuracy is high.
Therefore, an extremely simple transport mechanism such as the chain belt 22 can also be adopted.

Although the embodiments of the present invention have been described above, needless to say, the present invention is not limited to these, and various modifications can be made based on the technical idea of the present invention.

[0029] For example, in this embodiment, the object to be treated H was carried directly to the preheating chamber 1 integral with the transfer chamber 5 ₁ from the air, the transfer chamber 5 ₁ to increase the cut-off of the atmosphere A preliminary vacuum chamber may be provided before.

Further, in this embodiment, the seal rings 48 and 49 for closing the opening 13 of the heat treatment chamber 11 are adopted.
You may make it seal with a metal edge. Although the electric heater 14 is used to heat the heat treatment chamber 11, any heating source may be used as long as it can withstand temperatures other than 500 to 1000 ° C. and does not emit impurities. Further, in this embodiment, the chain belt 22 is used as the transport mechanism, but a roller conveyor can also be used.

In this embodiment, the gases introduced into the vacuum / gas atmosphere heat treatment furnace are argon and nitrogen.
You may introduce gas other than this as needed. Also,
In this embodiment, the tray 31, the tray pedestal 32 and the like are circular, but they may be rectangular.

[0032]

As described above, according to the vacuum / gas atmosphere heat treatment furnace of the present invention, among the components inserted into the heat treatment chamber, it is the metal that is carried out of the transfer chamber and is in contact with the atmosphere for a long time. Since it is a tray made only, the columns and the heat insulating material do not adsorb moisture because they are always in the transfer chamber, and therefore the amount of gas released is extremely small even when heated under vacuum in the heat treatment chamber together with the object to be processed. In addition to the tray, the transfer table that is carried out from the transfer chamber to the atmosphere and the tray receiving table are all made of metal to minimize the adsorption of moisture, which enables extremely high quality heat treatment. Is.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a vacuum / gas atmosphere heat treatment furnace of an example.

FIG. 2 is a vertical sectional view of a preheating chamber in the embodiment.

FIG. 3 is a sectional view taken along line [3]-[3] in the figure.

FIG. 4 is a vertical cross-sectional view of a first conventional example.

FIG. 5 is a vertical sectional view of a dewaxing chamber in a second conventional example.

[Explanation of symbols]

 1 Preheating Room 2 Degassing Room 3 Sintering Room 4 Cooling Room 5 Transfer Room 10 Vacuum / Gas Atmosphere Heat Treatment Furnace 11 Heat Treatment Room 12 Heat Insulation Material 22 Chain Belt 31 Tray 32 Tray Stand 33 Transfer Stand 41 Air Cylinder 44 Lifting Stand 45 Strut 46 heat insulating material 47 heat insulating material H

Claims (2)

[Claims] 1. An opening / closing door having an inlet for an object to be processed at one end and an outlet at the other end, which has a transport mechanism for the object to be processed connected from the inlet to the outlet. A horizontal transfer chamber composed of a plurality of compartments defined by a plurality of compartments, a heat treatment chamber or a plurality of heat treatment compartments provided above the compartments through insertion openings, respectively, and the conveyance compartments provided below the heat treatment compartments. In the vacuum / gas atmosphere heat treatment furnace, which comprises an elevating mechanism that raises the object to be processed on the mechanism to insert it into the heat treatment chamber from the insertion opening, and closes the insertion opening, the object to be treated is The elevating mechanism is placed together with a metal tray on a tray cradle having a metal opening that is placed on the opening of a metal carrier that has an opening through which the elevator mechanism can be inserted, and is transported by the transport mechanism. The lifting mechanism is A metal elevating table that is moved up and down in the opening of the carrier table, a plurality of columns for supporting the tray that is erected on the elevating table so as to be able to move up and down in the opening of the tray receiving table, and A heat insulating material provided on the tray side of the lifting table, and the support pillar integrated with the lifting table is lifted to support the object to be processed together with the tray and insert it into the heat treatment chamber from the insertion opening. Sometimes, the elevating table closes the insertion opening together with the tray pedestal that accompanies the ascending, and a vacuum / gas atmosphere heat treatment furnace. 2. The vacuum / gas atmosphere heat treatment furnace according to claim 1, wherein the transfer mechanism that transfers the transfer table is a chain belt.