JP5492540B2 - Heat treatment furnace - Google Patents

Description

  The present invention relates to a heat treatment furnace including a muffle.

  Conventionally, a furnace body made of a heat insulating material, a muffle constituting a processing chamber in which an object to be processed disposed in the furnace body is stored, a heater disposed in the furnace body so as to surround the muffle, and a lower end of the muffle And a movable body that can be moved up and down to and from the processing chamber through the opening of the chamber. There is known a heat treatment furnace in which a heater is energized and heat is applied to an object to be processed in a predetermined atmosphere.

  Further, in such a heat treatment furnace, the furnace body is configured to be separable into a plurality of parts, and after the heat treatment, the plurality of parts of the furnace body are opened to be separated from each other by an opening / closing mechanism, and the muffle is exposed to the outside air to be cooled. What was made into is also known (for example, refer patent document 1). According to this, the object to be processed can be cooled while being accommodated in the processing chamber, and the object to be processed can be prevented from being deteriorated by being exposed to the outside air during cooling.

  However, this structure has a problem that the structure of the furnace body becomes complicated and an opening / closing mechanism for the furnace body is required, which increases the cost.

JP 2002-147916 A

  This invention makes it the subject to provide the heat processing furnace which enabled it to cool a muffle efficiently, without opening and closing a furnace body in view of the above point.

  In order to solve the above-mentioned problems, the present invention is configured to surround a furnace body made of a heat insulating material, a muffle forming a processing chamber in which an object to be processed disposed in the furnace body is housed, and the furnace body. And a movable body that can be moved up and down through the opening at the lower end of the muffle to move the workpiece into and out of the processing chamber. The lower end is configured to be seated, and at the rising end position of the movable body, the opening of the lower end of the muffle is closed, and the lower end of the muffle is seated on the peripheral edge of the opening of the furnace body. A pressing plate that pushes up from the peripheral edge of the opening is provided, and further includes cooling means for flowing gas into the interior space of the furnace body to cool the muffle, and the cooling means is an opening at the bottom of the furnace body at the rising end position of the movable body. Wearing the periphery and the bottom of the muffle The gas is introduced into the furnace body from one of the gap formed between the opening and the openable / closable vent formed in the ceiling of the furnace body, and the gas is exhausted from the other. To do.

  According to the present invention, the seating portion at the lower end of the muffle is pushed up from the opening peripheral portion of the bottom of the furnace body by the pressing plate at the rising end position of the movable body, and a gap is generated between them. Then, by introducing gas into the furnace body from one of the gap and the vent hole in the ceiling of the furnace body and exhausting the gas from the other, the gas flows up and down along the outer peripheral surface of the muffle, and the muffle is efficient. Cools well. For this reason, the workpiece can be cooled in a short time while being accommodated in the processing chamber. Furthermore, since it is not necessary to open and close the furnace body as in the above-described conventional example, the structure of the furnace body is simplified and the opening and closing mechanism of the furnace body is not required, thereby reducing the cost.

  By the way, the heat treatment furnace generally includes a housing that covers the furnace body. In the present invention, when such a housing is provided, the movable body is provided with a cover plate that closes the opening opened at the bottom of the housing at the rising end position of the movable body, and is provided between the housing and the furnace body. A first space communicating with the vent hole and a second space communicating with the opening at the bottom of the furnace body, and an exhaust port communicating with one of the first space and the second space in the housing; It is preferable that an air supply port communicating with the other of the space and the second space is provided, and the cooling means is configured to supply gas to the air supply port and exhaust gas from the exhaust port.

  In this case, as the movable body rises to the rising end position, the second space communicates with the gap between the peripheral edge portion of the opening and the seating portion at the lower end of the muffle through the opening at the bottom of the furnace body above the cover plate. To do. And gas will be exhausted from one side of the 1st space and the 2nd space, and gas will be supplied from the other, and it will flow gas from one side of a vent hole and the above-mentioned gap toward the other in a furnace body Can do.

  Here, when air is used as the gas, the air supply port may be opened to the atmosphere and the air may be discharged from the exhaust port to the atmosphere. On the other hand, in the case of using a gas that requires a certain amount of cost, such as an inert gas, if the gas is discharged from the exhaust port into the atmosphere, the amount of gas consumption increases and the running cost increases. Therefore, the cooling means includes a ventilation path connecting the exhaust port and the air supply port, a fan interposed in the ventilation path for sucking gas from the exhaust port and blowing it to the air supply port, and a fan in series with the ventilation path. It is desirable to be comprised with the interposed heat exchanger for cooling. According to this, the gas is circulated between the furnace body and the ventilation path while being cooled by the heat exchanger, and the running cost can be reduced without impairing the cooling performance of the muffle.

Sectional drawing which shows the heat treatment furnace of embodiment of this invention The expanded sectional view of the principal part of the heat treatment furnace of FIG.

  Hereinafter, with reference to FIG. 1, FIG. 2, the heat processing furnace of embodiment of this invention is demonstrated. This heat treatment furnace includes a furnace body 1 made of a heat insulating material such as ceramics, and a metal housing 2 covering the furnace body 1. The furnace body 1 is formed in a cylindrical shape having a ceiling portion 11, and an opening 12 is opened at the bottom. Moreover, the housing 2 is also formed in the cylinder shape which has the ceiling part 21, and the opening 22 is opened in the bottom part.

  An annular plate 13 projecting outward is fixed to the upper surface of the ceiling portion 11 of the furnace body 1. An annular bracket 23 is fixed to the upper part of the inner surface of the peripheral wall portion of the housing 2, and the furnace body 1 is supported by the bracket 23 via the annular plate 13. In the housing 2, the first space 2 a between the ceiling portion 21 of the housing 2 and the ceiling portion 11 of the furnace body 1, and the first space 2 a is partitioned by the annular plate 13 and the bracket 23. A second space 2b between the peripheral wall portion and the bottom portion and the peripheral wall portion and the bottom portion of the furnace body 1 is provided. The second space 2 b is a space that communicates with the opening 12 at the bottom of the furnace body 1.

  A vent hole 14 is formed in the ceiling portion 11 of the furnace body 1, and the first space 2 a in the housing 2 is a space communicating with the vent hole 14. The vent hole 14 is opened and closed by a plug body 15 that is moved up and down by a cylinder 15 a provided in the ceiling portion 21 of the housing 2.

  In the furnace body 1, a heat-resistant metal muffle 3 constituting a processing chamber 3 a in which the workpiece W is stored, and a plurality of rod heaters 4 are arranged so as to surround the muffle 3. The muffle 3 has a ceiling portion 31 and is formed in a cylindrical shape having an open lower end. In addition, a movable body 5 that can be moved up and down is provided through which an object to be processed W is taken in and out of the processing chamber 3 a through an opening at the lower end of the muffle 3.

  The lower end of the muffle 3 is normally seated on the periphery of the opening 12 at the bottom of the furnace body 1. At the lower end of the muffle 3, as clearly shown in FIG. 2, an overhanging portion 32 a that slightly protrudes from the seating portion 32 to the peripheral portion of the opening 12 into the opening 12 is provided.

  The movable body 5 is provided with a support base 51 at the upper end that supports the workpiece W, a pressing plate 52 below the support base 51, and a lid plate 53 below the pressing plate 52, and these support bases 51, the pressing plate 52, and the lid plate 53 are connected to each other via a column 54. The pressing plate 52 comes into contact with the lower surface of the projecting portion 32a at the lower end of the muffle 3 before the rising end position of the movable body 5, closes the opening at the lower end of the muffle 3, and then rises to the rising end position. The seat 32 at the lower end of the muffle 3 is pushed up from the peripheral edge of the opening 12 at the bottom of the furnace body 1. Further, the lid plate 53 abuts against the bottom surface of the bottom of the housing 2 at the rising end position of the movable body 5 and closes the opening 22 at the bottom of the housing 2. The movable body 5 is moved up and down by a ball screw mechanism or the like not shown.

  In addition, a vacuum exhaust pipe 24 that extends downward through the ceiling portion 11 of the furnace body 1 is attached to the ceiling portion 21 of the housing 2. A flange portion 33 that is slidably fitted to the vacuum exhaust pipe 24 is provided on the ceiling portion 31 of the muffle 3 so that the processing chamber 3a can be evacuated. Further, the movable body 5 is provided with a gas supply pipe 55 extending above the pressing plate 52 so that an atmosphere gas such as an inert gas can be supplied to the processing chamber 3a via the gas supply pipe 55.

  Further, the heat treatment furnace of the present embodiment includes a cooling means 6 that cools the muffle 3 by flowing a gas into the internal space of the furnace body 1. The cooling means 6 has an air passage 61 connecting an exhaust port 25 communicating with the first space 2 a provided in the ceiling portion 21 of the housing 2 and an air supply port 26 communicating with the second space 2 b provided on the peripheral wall portion of the housing 2. A fan 62 that sucks gas from the exhaust port 25 and blows it to the air supply port 26, and a cooling heat exchanger 63 that is interposed in series with the fan 62. It is configured. In addition, as the heat exchanger 63, what cools gas by heat exchange with air | atmosphere, and what cools gas by heat exchange with cooling fluid, such as water, can be used.

  Further, in addition to the air supply port 26, an air supply / exhaust port 27 communicating with the second space 2 b is provided on the peripheral wall portion of the housing 2. A vacuum pump 7 is connected to the air supply / exhaust port 27, and a gas supply source 8 such as an inert gas is further connected via a valve 8a.

  In the heat treatment of the workpiece W, first, the movable body 5 is lowered to the lowered end position, the workpiece W is placed on the support base 51, and then the movable body 5 is raised to the raised end position. . According to this, the workpiece W is accommodated in the processing chamber 3 a through the opening 22 at the bottom of the housing 2, the opening 12 at the bottom of the furnace body 1, and the opening at the lower end of the muffle 3. Further, the seating portion 32 at the lower end of the muffle 3 is pushed up from the peripheral portion of the opening 12 at the bottom of the furnace body 1 in a state where the opening at the lower end of the muffle 3 is closed by the pressing plate 52, and the peripheral portion of the opening 12 and the seating portion 32 are pushed. And the opening 22 at the bottom of the housing 2 is closed by the lid plate 53. In this case, the second space 2 b in the housing 2 communicates with a gap between the peripheral portion of the opening 12 and the seating portion 32 via the opening 12 at the bottom of the furnace body 1 above the cover plate 53.

  Next, the vacuum pump 7 is operated and the internal space of the furnace body 1 is evacuated through the second space 2b. Further, after the processing chamber 3 a is evacuated through the vacuum exhaust pipe 24, the atmospheric gas is supplied to the processing chamber 3 a through the gas supply pipe 55. Thereafter, the heater 4 is energized to heat the muffle 3, and the workpiece W is subjected to a heat treatment in a predetermined atmosphere.

  When the heat treatment is completed, the gas from the gas supply source 8 is supplied to the second space 2b via the air supply / exhaust port 27, and the plug body 15 is further moved upward so that the vent hole in the ceiling portion 11 of the furnace body 1 is provided. 14 is opened and the fan 62 is activated. According to this, gas is sucked and exhausted from the internal space of the furnace body 1 through the vent hole 14, the first space 2 a and the exhaust port 25, and the gas cooled by the heat exchanger 63 is supplied to the air supply port 26. The gas is introduced into the furnace body 1 from the air supply port 26 through the second space 2 b and the gap between the opening 12 peripheral part of the bottom part of the furnace body 1 and the seating part 32.

  And the gas introduced from the clearance gap between the opening 12 peripheral part and the seating part 32 comes to flow upward along the outer peripheral surface of the muffle 3, and the muffle 3 is cooled efficiently. Therefore, the workpiece W can be cooled in a short time without being exposed to the outside air while being stored in the processing chamber 3a. Further, as compared with the conventional example in which the furnace body is opened and the muffle is exposed to the outside air, the structure of the furnace body 1 is simplified, and the opening / closing mechanism of the furnace body is not required, thereby reducing the cost. Can be planned.

  When the cooling of the workpiece W is completed, the movable body 5 is lowered to the lower end position, and the processed workpiece W on the support base 51 is taken out. Thereafter, a new workpiece W is placed on the support base 51, and the above-described processing cycle is repeated.

  As mentioned above, although the heat processing furnace of embodiment of this invention was demonstrated with reference to drawings, this invention is not limited to this. For example, the exhaust port 25 and the air supply port 26 of the above-described embodiment can be made into an air supply port and an exhaust port, respectively, by reversing the air blowing direction of the fan 62. According to this, gas is introduced into the furnace body 1 from the vent hole 14, and the gas is exhausted from the gap between the seating portion 32 and the periphery of the opening 12. In this case, the gas flows downward along the outer peripheral surface of the muffle 3, and the muffle 3 is efficiently cooled as in the above embodiment.

  Further, when air is used as the cooling gas, the ventilation path 61 is omitted, the air supply port 26 can be opened to the atmosphere through a gate valve, and air is introduced from the air supply port 26 during cooling to exhaust the air. Air may be discharged from the opening 25 to the atmosphere via a fan. In addition, when using a gas that costs a certain amount, such as an inert gas, as the cooling gas, if the gas is released into the atmosphere, the amount of gas consumption increases and the running cost increases. It is desirable to provide a ventilation path 61 to circulate the gas in the furnace body 1 and the ventilation path 61.

  DESCRIPTION OF SYMBOLS 1 ... Furnace body, 11 ... Ceiling part, 12 ... Opening, 14 ... Air hole, 2 ... Housing, 2a ... 1st space, 2b ... 2nd space, 21 ... Ceiling part, 22 ... Opening, 25 ... Exhaust port, 26 Air supply port, 3 ... Muffle, 3a ... Processing chamber, 32 ... Seat, 4 ... Heater, 5 ... Movable body, 52 ... Press plate, 53 ... Cover plate, 6 ... Cooling means, 61 ... Ventilation path, 62 ... Fan, 63 ... heat exchanger.

Claims (3)

A furnace body made of a heat insulating material, a muffle forming a processing chamber in which an object to be processed disposed in the furnace body is stored, a heater disposed in the furnace body so as to surround the muffle, and an opening at the lower end of the muffle A heat-treating furnace provided with a movable body that can be moved up and down to and from the processing chamber through the processing chamber,
The lower end of the muffle is seated on the peripheral edge of the opening established at the bottom of the furnace body, and the movable body is closed at the rising end position of the movable body, and the opening of the lower end of the muffle is closed. There is provided a pressing plate that pushes up the seating portion at the lower end of the muffle seated on the opening periphery of the opening from the opening periphery,
Furthermore, a cooling means for cooling the muffle by flowing a gas into the interior space of the furnace body is provided, and the cooling means is provided between the opening peripheral edge of the bottom of the furnace body and the seating portion at the lower end of the muffle at the rising end position of the movable body. A heat treatment furnace characterized in that a gas is introduced into the furnace body from one of a gap formed in the furnace body and an openable / closable vent hole formed in a ceiling portion of the furnace body, and the gas is exhausted from the other.   A housing that covers the furnace body, and the movable body is provided with a lid plate that closes an opening formed in a bottom portion of the housing at the rising end position of the movable body, and the passage is interposed between the housing and the furnace body. A first space that communicates with the pores and a second space that communicates with the opening at the bottom of the furnace body are provided, the housing has an exhaust port that communicates with one of the first space and the second space, and the first space. An air supply port communicating with the other of the second space is provided, and the cooling means is configured to supply gas to the air supply port and exhaust gas from the exhaust port. The heat treatment furnace according to 1.   The cooling means includes a ventilation path connecting the exhaust port and the air supply port, a fan interposed in the ventilation path for sucking gas from the exhaust port and blowing it to the air supply port, and a fan in the ventilation path. The heat treatment furnace according to claim 2, wherein the heat treatment furnace comprises a cooling heat exchanger interposed in series.

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