KR20100122943A - Single chamber vacuum heat treating furnace and method of preventing oxidation of article to be treated in single chamber vacuum heat treating furnace - Google Patents

Abstract

A water cooling jacket 15 is provided on the furnace wall 11, and the furnace body 11 has a processing space S of the object to be processed W formed therein by the furnace wall 11 and in the furnace body 1. In the heating device 2 for heating the installed object W, the cooling gas supply device 3 for supplying the cooling gas into the processing space S, and the heat exchanger 52 provided in the processing space S. A first refrigerant circulation system for cooling the object W through the cooling gas, a decompression device 4 for reducing the pressure in the processing space, and a second supply of the refrigerant C to the cooling jacket 15. In the single chamber vacuum heat treatment furnace A provided with the refrigerant circulation system, the said 2nd refrigerant circulation system is equipped with the refrigerant | coolant heating part 65 which heats the refrigerant | coolant C. As shown in FIG. According to the said structure, condensation of the inner surface of the furnace main body 1 can be prevented effectively in a short time, work efficiency can be improved, and a favorable to-be-processed object can be obtained.

Description

Single chamber vacuum heat treating furnace and method of preventing oxidation of article to be treated in single chamber vacuum heat treating furnace}

The present invention relates to a single chamber vacuum heat treatment furnace used for performing heat treatment such as quenching on a metal product, and a method for preventing oxidation of a workpiece in a single chamber vacuum heat treatment furnace.

This application claims priority based on Japanese Patent Application No. 2008-62557 for which it applied to Japan on March 12, 2008, and uses the content here.

Conventionally, this type of apparatus is provided with an object to be processed in the furnace body through an opening of the furnace body, and the inside of the furnace body is vacuumed after closing the opening. After the article is heated and heat treated, a cooling gas is introduced into the furnace body to cool the workpiece. Then, the opening is opened to replace the workpiece with a new workpiece. It is known to perform a heat treatment.

In such an apparatus, the furnace wall is cooled by supplying a refrigerant in a cooling jacket provided on the furnace wall in order to prevent the furnace wall from becoming hot during the heat treatment of the workpiece to deteriorate the working environment and deteriorate the furnace wall.

By the way, in such a single chamber vacuum heat treatment, when the furnace door is opened after vacuum heat treatment and the object to be processed is taken out, when the inner surface temperature of the furnace body is lower than the outside air temperature by the cooling treatment, moisture in the outside air introduced into the furnace is released. Condensation forms on the inner surface of the furnace body. In this state, when a new to-be-processed product is installed in a furnace and heated, condensation droplets gradually evaporate and become water vapor during vacuum heat treatment, which oxidizes the surface of the to-be-processed product to color the to-be-processed product.

In Patent Literature 1 below, as a pre-process and / or post-process of vacuum heat treatment of an object to be processed, the cooling gas is circulated into the furnace with the furnace door closed, and the cooling gas is heated by a heating apparatus installed in the furnace. A method is disclosed in which the whole is heated to a temperature at which the article to be treated is sufficiently higher than the evaporation temperature of water to prevent oxidation and coloring, thereby preventing condensation on the inner surface of the furnace body and thus oxidation and coloring of the article to be processed.

Patent Document 1: Japanese Unexamined Patent Publication No. 2006-10097

However, in the related art, since the coolant is supplied in the cooling jacket provided on the furnace wall of the furnace body, even when the heated cooling gas is circulated, a considerable time is required for the temperature increase of the inner surface of the furnace body. Therefore, it is necessary to wait until starting processing of the next to-be-processed object, and as a result, there exists a problem that the processing efficiency of a to-be-processed object falls.

The present invention has been made in view of such circumstances, and its object is to prevent condensation in a furnace effectively in a short time, and to improve work efficiency in a single-room vacuum heat treatment furnace and a single-room vacuum heat treatment furnace that can obtain a good to-be-processed product. The present invention provides a method for preventing oxidation of an object to be treated.

In order to achieve the above object, the present invention proposes the following means.

That is, the present invention relates to a furnace body in which a water-cooling jacket is provided on a furnace wall, and a treatment space for an object to be processed is formed inside the furnace wall as a first means of a single chamber type vacuum heat treatment furnace, and an object to be processed in the furnace body. A heating device to heat, a cooling gas supply device for supplying cooling gas into the processing space, a first refrigerant circulation system for cooling the object to be processed through the cooling gas by a heat exchanger provided in the processing space, and a reduced pressure to depressurize the inside of the processing space. In a single chamber vacuum heat treatment furnace having a device and a second refrigerant circulation system for supplying a refrigerant to the cooling jacket, the second refrigerant circulation system employs a means for providing a refrigerant heating portion for heating the refrigerant.

A second means relating to a single chamber type vacuum heat treatment furnace, wherein in the first means, the second refrigerant circulation system includes a refrigerant cooling unit for cooling the refrigerant supplied to the cooling jacket, and a refrigerant heating unit. Means are employed in which the real vacuum heat treatment furnace includes a sensor for measuring the temperature of the coolant in the second coolant circulation system and a control device for controlling the coolant heating section and the coolant cooling section based on the output signal of the sensor.

A third means of a single chamber type vacuum heat treatment furnace, wherein in the second means, the furnace body has an opening for carrying in and out of an object to be processed, and an open door for opening and closing an opening and an open door. And a lock mechanism for releasing the blockage of the opening by the control device. The control device closes the furnace door during the cooling of the workpiece, and maintains the blockage when the temperature of the refrigerant is maintained at a temperature higher than the ambient temperature outside the furnace after the cooling. The means which is provided with the lock mechanism control part for releasing is employ | adopted.

As a first means of the oxidation prevention method of a to-be-processed object in a single chamber type vacuum heat treatment furnace, the to-be-processed product is installed in a furnace body through the opening part of a furnace body, and the inside of a furnace body is vacuumed after closing an opening part, After cooling the furnace wall by supplying a coolant in a cooling jacket installed on the furnace wall of the furnace body, heating the workpiece and heating it, a cooling gas is introduced into the furnace body to cool the workpiece, and then the opening is opened. A method of preventing oxidation of a workpiece in a single chamber vacuum heat treatment furnace in which an opening is replaced with a new workpiece to sequentially heat-treat the workpiece. A method of preventing oxidation of a workpiece by heating the refrigerant after cooling the workpiece is performed by raising a furnace wall. Means for preventing the generation of water vapor during the heat treatment of the workpiece to prevent oxidation of the workpiece are employed.

As a second means of the oxidation prevention method of a to-be-processed object in a single chamber type vacuum heat-treatment furnace, in the said 1st means, carrying in the to-be-processed object by maintaining the temperature of a refrigerant | coolant more than the ambient temperature outside a furnace, and predetermined time. Or means for carrying out.

Moreover, as a 3rd means which concerns on the oxidation prevention method of the to-be-processed object in a single chamber type vacuum heat processing furnace, in a said 2nd means, a furnace main body is maintained until the temperature of a refrigerant | coolant is maintained more than the ambient temperature outside a furnace and for predetermined time. Adopt a means to close the prosecution.

According to the present invention, since the refrigerant heating portion for heating the refrigerant supplied to the cooling jacket provided on the furnace wall is provided, the inner surface of the furnace body is directly heated up. As a result, condensation on the inner surface of the furnace body can be effectively prevented in a short time, and the working efficiency can be improved to obtain a good to-be-processed product.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the whole structure of the single chamber type vacuum heat processing furnace in one Embodiment of this invention.
FIG. 2 is a cross-sectional view taken along the line AA in FIG. 1.
3 is an excerpt of a part of the single-bed vacuum heat treatment furnace treatment step according to the first embodiment of the present invention.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described with reference to drawings.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the whole structure of the single chamber type vacuum heat processing furnace A which concerns on embodiment of this invention, and FIG. 2 is sectional drawing along the line A-A in FIG. 1 has shown the state which sealed the heating chamber R, and FIG. 2 has shown the state which opened the heating chamber R. Moreover, FIG.

As shown in FIG. 1, the single chamber type vacuum heat treatment furnace A includes a furnace body 1, a heating device 2, a cooling gas supply device 3, a pressure reducing device 4, a cooling device 5, and a refrigerant. The circulation system 6 and the control apparatus 8 are provided.

The furnace body 1 is formed in the substantially cylindrical shape by the furnace wall 11, and the process space S of the to-be-processed object W is formed in the inside. This furnace body 1 is provided in the floor F via the leg part 17 located in the lower side so that a center axis | shaft (center axis of the said cylinder) may become horizontal.

The furnace body 1 is equipped with the container trunk | drum 12, the furnace door 13, the lock mechanism 14, and the cooling jacket 15. As shown in FIG.

The container body part 12 is comprised by the furnace wall 11a, and is a substantially cylindrical shape by which one end part becomes the opening part 12a, and accommodates the heating apparatus 2 etc. in the inside of the container body part 12, and In addition, the to-be-processed object W is carried in and out from the opening part 12a. As shown in FIG. 2, two parallel floors are formed below the container body portion 12 in parallel with each other along the central axis direction of the furnace body 1 from the opening portion 12a to the vicinity of the other end portion. The part 12b is formed. Moreover, the flange part 12c is formed in the furnace wall 11a surrounding the periphery of the opening part 12a.

The furnace door 13 is a substantially disk-shape comprised by the furnace wall 11b, and opens and closes the opening part 12a. At the periphery of this furnace door 13, the flange part 13a formed so that it may overlap with the flange part 12c at the time of closing of the opening part 12a is formed.

The lock mechanism 14 closes the opening 12a by the door 13 and releases it. Specifically, it consists of the clamp ring 14a engaged with the flange part 12c and the flange part 13a, and the drive mechanism 14b which tightens the clamp ring 14a, The flange part 12c and a flange part It is possible to fix firmly in the state which contacted 13a, and to seal the container trunk | drum 12. As shown in FIG.

The cooling jackets 15 (15a, 15b) are respectively provided at both ends of the furnace walls 11 (11a, 11b) so as to surround the processing space S, and supply ports 15a1, 15b1 to which the refrigerant C is supplied, respectively. ) Is provided, and outlets 15a2 and 15b2 for discharging the refrigerant C are provided. In addition, the cooling jackets 15a and 15b are independent from each other without directly communicating.

The heating apparatus 2 is supported by the parallel floor 12b and accommodated in the container trunk | drum 12. As shown in FIG. This heating apparatus 2 is provided with the box-shaped heat insulating material 22 in which the wheel 21 was provided, the heater 26, and the hearth 27 (hearth).

The wheel 21 is the box-shaped heat insulating material 22 so that the heating chamber R comprised by the box-shaped heat insulating material 22 can move on the parallel floor part 12b in the direction of the central axis of the furnace body 1. It is attached to the bottom surface of the bottom plate 22a (described later).

The box-shaped heat insulating material 22 is a ceramic fiber product, and comprises the heating chamber R. As shown in FIG. That is, the heating chamber R is the bottom plate 22a in which the wheel 21 is provided, the front wall 22b provided in the opening part 12a side, and the back wall 22c provided so as to oppose this front wall 22b. And the side walls 22d and 22e and the upper plate 22f provided along the central axis of the furnace body 1 and parallel to each other, and can accommodate the object to be processed W. FIG.

This box-shaped heat insulating material 22 is provided with a thermocouple (not shown) for measuring the temperature of the heating chamber R, and this measurement signal is transmitted to the control apparatus 8.

Further, the front wall 22b is provided with a carrying in / out port 23a of the object W and a heating chamber door 23b that can open and close it. In addition, the bottom plate 22a is provided with a cooling gas inlet 24a and a lower cover 24b capable of opening and closing it, and the upper plate 22f is formed with a cooling gas outlet 25a and is opened and closed. The upper cover 25b which is possible is provided.

The lower cover 24b is vertically driven by the pneumatic cylinder 24c provided in the lower part outside the furnace, and the upper cover 25b is driven horizontally by the pneumatic cylinder 25c provided in the side part outside the furnace. The heating chamber door 23b is opened and closed by an opening and closing device (not shown).

In this way, while the carry-in / out port 23a is closed by the heating chamber door 23b, the heating chamber R is sealed by closing the lower lid 24b and the upper lid 25b, and the lower lid 24b. ) And the upper cover 25b open the heating chamber R in communication with the outside.

The heater 26 is provided in the heating chamber R to surround the to-be-processed object W, when the to-be-processed object W is carried in to the heating chamber R. As shown in FIG.

The hearth 27 is comprised from the several rod-shaped member parallel to the central axis of the furnace main body 1, and is provided in the bottom plate 22a.

The cooling gas supply device 3 supplies the cooling gas G to the processing space S, and the pressure reduction device 4 exhausts outside air introduced from the opening 12a to depressurize the processing space S.

The cooling device 5 is provided with the blower 51 and the heat exchanger 52.

The blower 51 is provided with the cooling fan 51a which blows cooling gas G, and the fan motor 51b which rotates this cooling fan 51a, The cooling fan 51a is located in a furnace, and a fan It is provided in the upper part of the furnace main body 1 so that the motor 51b may be located outside a furnace.

The heat exchanger 52 has a plurality of heat transfer tubes through which the coolant C flows, and is installed above the furnace in the furnace body 1 such that the plurality of heat transfer tubes surround the cooling fan 51a.

The refrigerant circulation system (first refrigerant circulation system, second refrigerant circulation system) 6 includes a cooling jacket 15, a heat exchanger 52, a refrigerant tank 61, a circulation pump 62, a three-way valve 63, and in parallel It consists of the refrigerant | coolant cooling part 64 arrange | positioned, the refrigerant | coolant heating part 65, and the piping 66 (66a-66m) sequentially installed between them.

The coolant tank 61 functions as a storage tank of the coolant C, and a constant coolant C is always stored. In this embodiment, oil is used as the refrigerant C.

The coolant tank 61 is provided with a thermocouple 71. This thermocouple 71 measures the temperature of the refrigerant | coolant C stored in the refrigerant | coolant tank 61, and supplies the signal based on it to the control apparatus 8 continuously.

The circulation pump 62 communicates with the coolant tank 61 by the pipe 66a, and delivers the coolant C stored in the coolant tank 61 to the pipe 66b.

The three-way valve 63 is electric, and the piping 66b, the piping 66c which communicates with the refrigerant | coolant cooling part 64, and the piping 66d which communicates with the refrigerant | coolant heating part 65 are connected. That is, by operating this three-way valve 63, the system path of the refrigerant C sent out from the circulation pump 62 can be switched to either the pipe 66c or the pipe 66d.

The coolant cooling unit 64 exchanges heat with the coolant C introduced from the pipe 66c to cool the coolant C, and communicates with the pipe 66e through which the cooled coolant C flows out.

The coolant heating unit 65 heats the coolant C by performing heat exchange with the coolant C introduced from the pipe 66d and communicates with the pipe 66f through which the heated coolant C flows out.

After the pipe 66e and the pipe 66f communicate with each other to form one pipe, the pipe 66e and the pipe 66f are connected to the pipe 66g connected to the supply port 15a1 of the jacket 15a and to the supply port 15b1 of the jacket 15b. Branches are divided into three pipes of the pipe 66h and the pipe 66i connected to the heat exchanger 52.

The refrigerant C introduced into the cooling jackets 15a and 15b from the pipe 66g and the pipe 66h respectively flows into the cooling jacket 15 surrounding the processing space S, and then discharges the outlets 15a2, 15b2) flows into piping 66j and 66k, respectively, and is stored by the refrigerant | coolant tank 61 which communicates with these piping 66j and 66k. Similarly, the refrigerant C flowing through the heat transfer tube of the heat exchanger 52 is stored in the refrigerant tank 61 through the pipe 66m.

In this way, the refrigerant circulation system 6 is configured.

The control device 8 controls the operation of the circulation device 62 of the heating device 2, the cooling gas supply device 3, the pressure reducing device 4, the cooling device 5, and the refrigerant circulation system 6.

For example, the control apparatus 8 energizes the heater 26 at the time of the heat processing of the to-be-processed object W, heats the to-be-processed object W to a desired temperature, and coolant C cools. Cooling the refrigerant (C) by making the circulation path as a pipe (66c) and by operating the refrigerant cooling unit 64 as possible. Similarly, when the set temperature is higher than the furnace temperature in the cooling process, the control device 8 cools the refrigerant C. As shown in FIG. In addition, the temperature and time of heat processing and cooling processing change suitably according to the kind of metal of the to-be-processed object W, and the kind of heat processing.

The control device 8 is a case in which the temperature of the coolant C is lower than the set temperature t during the cooling process of the workpiece W until the charging of the new workpiece W is completed. The refrigerant C is heated up. Specifically, the three-way valve 63 is operated to switch the refrigerant circulation system to the pipe 66d, and the refrigerant heating unit 65 is operated to heat the refrigerant. Moreover, the set temperature t of this refrigerant | coolant C is set to the temperature (temperature which exceeds about 10 degreeC outside air temperature) which can effectively prevent the dew condensation of the inner surface of the furnace main body 1 generally. In addition, the information of the outside air temperature is supplied to the control device 8 as an output signal from a temperature sensor (not shown) provided outside the furnace.

Moreover, this control apparatus 8 is equipped with the lock mechanism control part 81. As shown in FIG. The lock mechanism control unit 81 closes the furnace door 13 during the cooling of the object W and cools the temperature of the coolant C after the cooling to a predetermined temperature t or more for a predetermined time T. In the case of holding, the blockage of the door 13 is released.

Next, the operation of the single chamber vacuum heat treatment furnace A having the above configuration will be described. 3 extracts a part of the treatment step of the single chamber vacuum heat treatment furnace A. FIG. In addition, in the following description, the case where hardening of the some to-be-processed object W is performed is demonstrated. It is also assumed that a sufficient time has elapsed from the heat treatment immediately before the heat treatment, and the furnace temperature is equal to the outside air temperature, and the coolant C is always circulating through the coolant circulation system 6.

First, the open door 13 is opened to open the opening 12a, the heating chamber R is exposed to the outside, and the heating chamber door 23b is opened to open the carry-in / out port 23a.

Next, the workpiece W is made to face the opening 12a with the charging extraction stand placed at approximately the same height as the hearth 27. And after carrying in the to-be-processed object W into the inside of the heating chamber R, the charging extraction stand is spaced apart from the opening part 12a, the heating chamber door 23b is closed, and the carrying-in / out port 23a is closed. . Moreover, the door 13 is closed so that the flange part 13a may overlap with the flange part 12c, the clamp ring 14a is tightened firmly by the drive mechanism 14b, and the container trunk | drum 12 is sealed.

Next, the decompression device 4 is operated to depressurize the processing space S. FIG. At this time, the cooling gas introduction port 24a of the bottom plate 22a and the cooling gas discharge port 25a of the upper plate 22f in the heating chamber R are open. After the predetermined degree of vacuum is reached, the pneumatic cylinders 24c and 25c are operated to drive the lower cover 24b and the upper cover 25b to close the cooling gas inlet 24a and the cooling gas outlet 25a, respectively. do.

Next, by energizing the heater 26, the workpiece W is heated at a predetermined temperature and a predetermined time. At this time, since the furnace wall 11 and the heat exchanger 52 are heated by radiation from the heater 26, the temperature of the refrigerant C rises, so that the passage of the refrigerant circulation system 6 is the pipe 66c. The coolant cooling unit 64 is operated to cool the coolant C, and the furnace wall 11 is cooled.

After the heat treatment, the pneumatic cylinders 24c and 25c are operated again to drive the lower cover 24b and the upper cover 25b to open the cooling gas inlet 24a and the cooling gas outlet 25a, respectively. The cooling gas supply device 3 is operated to supply the cooling gas G (see FIG. 2).

At the same time, the cooling device 5 is driven to circulate the cooling gas G into the processing space S. FIG. At this time, the cooling gas G is cooled by performing heat exchange with the refrigerant C flowing inside the heat transfer tube of the heat exchanger 52, and the heat received by the refrigerant C from the cooling gas G is the refrigerant cooling unit 64. Heat dissipation Moreover, in the heating chamber R, it circulates so that it may pass through the hearth 27 from the cooling gas introduction port 24a, and will be discharged | emitted from the cooling gas discharge port 25a.

The control device 8 that detects the completion of the cooling process (step S1) measures the temperature of the coolant C and determines whether the temperature of the coolant C is higher than the set temperature t (step S2). .

If the judgment of step S2 is "no", that is, when the temperature of the refrigerant C falls below the set temperature t, whether the passage of the refrigerant circulation system 6 by the three-way valve 63 is the pipe 66c. (Step S3).

If the determination of step S3 is YES, the three-way valve 63 is operated to switch the path of the refrigerant circulation system 6 in the direction of the pipe 66d (step S4). In this embodiment, since the refrigerant | coolant cooling part 64 was operated after making into the piping 66c the path | route of the refrigerant | coolant circulation system 6 to cool the furnace wall 11 and cooling gas G as mentioned above, The valve 63 is operated to switch the path of the refrigerant circulation system 6 in the direction of the pipe 66d.

After step S4 or when the determination in step S3 is no, the coolant C is heated to heat the coolant C until it reaches a predetermined temperature (step S5). That is, the refrigerant C heated by the refrigerant heating unit 65 is supplied to the cooling jacket 15, so that the inner surface of the furnace body 1 and the heat exchanger 52 are directly heated up. At this time, the cooling gas G is circulated.

After that, the determination of step S2 is made again.

When the determination of step S2 is YES, the lock mechanism control unit 81 of the control device 8 determines whether the predetermined time refrigerant C is equal to or higher than the set temperature t (step S6). In addition, the predetermined time is set for the time when the cooling gas G is heated in the heat exchanger 52 and the furnace wall 11, and the furnace temperature becomes more than the outside temperature by this cooling gas G. As shown in FIG.

If the judgment of step S6 is "no", then judgment of step S2 is made again.

If the judgment of step S6 is YES, the drive mechanism 14b of the lock mechanism 14 is operated on the premise that the furnace is at atmospheric pressure to release the clamping of the clamp ring 14a (step S7).

After the lock mechanism 14 is released, the door 13 is opened, the opening 12a is opened, and the heating chamber door 23b of the heating chamber R is opened to open the carry-in / out port 23a. (Step S8). At this time, in addition to the inner surface of the furnace body 1 and the heat exchanger 52, the heating chamber R and the fan 51a are also at a set temperature.

Thereafter, the charging extraction stand is faced to the hearth 27 again, and the quenched workpiece W is taken out. From carrying out the workpiece W to carrying in a new workpiece W, the control device 8 continuously controls the temperature of the refrigerant C to be equal to or higher than the set temperature t. The same judgment as in S5 is repeated (steps S9 to 12).

That is, while the opening 12a is opened, the inner surface of the furnace body 1 and the heat exchanger 52 are kept at a temperature higher than or equal to the set temperature t, and the heating chamber R and the fan 51a are also set. Since the temperature is near the temperature, no dew condensation occurs even if outside air flows into the furnace.

Then, after charging the new to-be-processed object W to the heating chamber R (step S13), the heating chamber door 23b and the furnace door 13 are closed again, and heat processing is started similarly to the above. At this time, even if the workpiece W is heated by the heater 26, condensation does not occur in the heating chamber R or the fan 51a in addition to the inner surface of the furnace body 1 and the heat exchanger 52. No steam is generated in the furnace.

At the same time, it is determined whether the path of the refrigerant circulation system 6 by the three-way valve 63 is the pipe 66c (step S14), and when the determination of step S14 is YES, the process ends and the determination of step S14 is performed. In the case of "NO", in order to cool the refrigerant C during the heat treatment, the passage of the refrigerant circulation system 6 is switched to the pipe 66c (step S15), and the processing is finished.

Since no water vapor is generated in the furnace, the new to-be-processed object W is not oxidized and no coloration is caused, and the heat treatment is completed.

As described above, according to the single chamber type vacuum heat treatment furnace A, the refrigerant circulation section 6 includes the refrigerant heating portion 65 for heating the refrigerant C, so that the inner surface of the furnace body 1 is directly connected. It is heated up. As a result, condensation on the inner surface of the furnace body 1 can be effectively prevented in a short time, and work efficiency can be improved to obtain a good workpiece W.

Moreover, since the thermocouple 71 which measures the temperature of the refrigerant | coolant C and the control apparatus which controls the refrigerant | coolant heating part 65 and the refrigerant cooling part 64 based on the output signal of the thermocouple 71 are heated, It is possible to change the temperature of the refrigerant C appropriately by dividing it into the processing time and the cooling process time, and to change the temperature of the refrigerant C from the end of the cooling process until the charging of a new workpiece W. It is also possible to change.

In addition, the control device 8 closes the furnace door 13 during the cooling of the object W and maintains the temperature of the coolant C at a predetermined temperature t or more and a predetermined time T after cooling. In one case, since the lock mechanism control part 81 which releases | releases is provided, condensation other than the inner surface of the furnace main body 1 and the heat exchanger 52 can be effectively prevented by adjusting the furnace temperature to desired temperature. In addition, it is possible to completely prevent the furnace door 13 from being opened accidentally after the end of cooling before the furnace temperature becomes higher than the desired temperature.

In addition, since oil is used as the refrigerant C, accumulation of scale generated when water is used as the refrigerant can be prevented.

In addition, the operation sequence shown in embodiment mentioned above, various shapes, materials, a combination, etc. of each structural member are an example, and can be variously changed based on a design request etc. in the range which does not deviate from the well-known of this invention.

For example, in this embodiment, although the cooling jacket 15 and the heat exchanger 52 were comprised as what is common as the refrigerant | coolant circulation system 6, you may make these independent structures.

In addition, in this embodiment, although the three-way valve 63 was provided and the refrigerant | coolant cooling part 64 and the refrigerant | coolant heating part 65 were arrange | positioned in parallel, it was comprised, but these were installed in series without providing the three-way valve 63. You may arrange.

In addition, in this embodiment, although oil was used as the refrigerant | coolant C, of course, this may be cooling water.

In addition, in this embodiment, although the wheel 21 was provided in the box-shaped heat insulating material 22, this was provided in order to improve the maintainability of the heating chamber R, and it is not necessary to necessarily install.

In addition, in this embodiment, although the refrigerant | coolant C was made to circulate the refrigerant | coolant circulation system 6 continuously, for example, the refrigerant | coolant C to the heat exchanger 52 during the heat processing of the to-be-processed object W. May be stopped or the supply of the coolant C to the cooling jacket 15 during the cooling process may be stopped.

In this single chamber type vacuum heat treatment furnace, since the refrigerant | coolant heating part which heats the refrigerant | coolant supplied to the cooling jacket provided in the furnace wall is heated, the inner surface of a furnace main body is heated up directly. As a result, condensation on the inner surface of the furnace body can be effectively prevented in a short time, and the working efficiency can be improved to obtain a good to-be-processed product.

1 nobody
2 heating device
3 feeder
4 decompression device
5 cooling system
6 refrigerant circulation system
8 control unit
11 (11a, 11b) furnace wall
12a opening
13 Presbytery
14 lock mechanism
15 (15a, 15b) cooling jacket
52 heat exchanger
64 Refrigerant Cooling Unit
65 Refrigerant Heating Section
71 Thermocouples (Sensors)
81 lock mechanism control unit
A single chamber vacuum heat treatment furnace
C refrigerant
G cooling gas
S processing space
W to be processed

Claims (6)

A furnace body in which a water cooling jacket is provided on the furnace wall, and the treatment wall of the object to be processed is formed therein by the furnace wall;
A heating device for heating the workpiece to be installed in the furnace body;
A cooling gas supply device for supplying cooling gas into the processing space;
A first refrigerant circulation system for cooling the object to be processed through the cooling gas by a heat exchanger installed in the processing space;
A decompression device for depressurizing the inside of the processing space;
In the single chamber type vacuum heat treatment furnace provided with the 2nd refrigerant circulation system which supplies a refrigerant | coolant to the said cooling jacket,
A single chamber vacuum heat treatment furnace, wherein the second refrigerant circulation system comprises a refrigerant heating unit for heating the refrigerant. The method of claim 1,
The second refrigerant circulation system comprises a refrigerant cooling unit for cooling the refrigerant supplied to the cooling jacket, and the refrigerant heating unit,
A single chamber vacuum heat treatment furnace including a sensor for measuring the temperature of the refrigerant and a control device for controlling the refrigerant heating unit and the refrigerant cooling unit based on an output signal of the sensor. The method of claim 2,
The furnace body is provided with an opening for carrying in and carrying out the object to be processed into the inside of the furnace body, a furnace door for opening and closing the opening, and a locking mechanism for releasing the blockage of the opening by the furnace door.
The control device includes a lock mechanism control unit that closes the furnace door during the cooling of the object and releases the blockage when the temperature of the refrigerant is maintained above the ambient temperature outside the furnace and for a predetermined time after cooling. Single chamber vacuum heat treatment furnace. The workpiece is charged and installed from the opening of the furnace body into the furnace body, and after closing the opening, the inside of the furnace body is vacuumed, and the refrigerant is supplied into the cooling jacket provided on the furnace wall of the furnace body to provide a furnace wall. After cooling the product to be heated by heating it, and then introducing a cooling gas into the furnace body to cool the workpiece, and then opening the opening to open the workpiece. As a method for preventing oxidation of a workpiece in a single chamber vacuum heat treatment furnace in which the workpiece is subjected to heat treatment sequentially by exchanging with
Oxidation of the workpiece in a single chamber vacuum heat treatment furnace which prevents the generation of water vapor during the heat treatment of the new workpiece by preventing the oxidation of the workpiece by heating the refrigerant after heating the workpiece to cool the furnace wall. Prevention method. The method of claim 4, wherein
The oxidation prevention method of the to-be-processed object in the single chamber type vacuum heat processing furnace which keeps the temperature of the said coolant more than the temperature around the outside of a furnace, and for predetermined time. The method of claim 5,
The oxidation prevention method of the to-be-processed object in the single chamber type vacuum heat treatment furnace which closes the furnace door of the said furnace main body until the temperature of the said refrigerant | coolant is maintained more than the temperature of the outside of a furnace, and predetermined time.

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