CN115874033A - Heat treatment apparatus - Google Patents

Abstract

The invention provides a heat treatment apparatus which can inhibit the leakage of atmosphere gas from the boundary of adjacent muffle furnaces in a plurality of divided muffle furnaces. The heat treatment apparatus includes: a ceramic muffle (11) in which a heat treatment space (S) for heat treatment of a workpiece (W) is formed; and a metal cover (30) which covers the muffle (11), wherein the muffle (11) is divided into a plurality of parts, and the plurality of divided muffle parts are arranged in a manner of connecting the heat treatment space (S). The cover (30) comprises: a plurality of main covers (31) which cover the boundaries (K1) of adjacent ones of the plurality of divided muffle furnaces; and a sub-cover (32) that connects the plurality of main covers (31) to each other.

Description

Heat treatment apparatus

Technical Field

The present invention relates to a heat treatment apparatus.

Background

Patent document 1 discloses a heat treatment furnace having a retort in which the outside of a ceramic tube is covered with a metal case, and performing heat treatment while conveying a workpiece in the axial direction inside the ceramic tube. In this heat treatment furnace, the ceramic pipe is divided into a plurality of divided bodies in the axial direction, and the plurality of divided bodies are inserted into 1 metal case.

Patent document 1: japanese patent laid-open publication No. 2015-83919

In the heat treatment furnace described in patent document 1, it is not easy to completely eliminate the gap at the boundary between the adjacent divided bodies of the ceramic tube, and there is a possibility that the atmosphere gas leaks from the gap or the external gas enters. On the other hand, since the plurality of segments are covered with the metal case, leakage of the atmosphere gas from the gap and the like are suppressed to some extent. However, the metal case is more likely to be thermally deformed than the ceramic tube. The metal case is formed of 1 long cylinder. Further, the cylindrical body covers all of the plurality of divided bodies, and therefore, has a large volume. If the volume of the cylindrical body becomes large, the cylindrical body is likely to be largely warped by heat. Therefore, the amount of deformation of the metal case due to heat increases. Therefore, the metal shell may partially float from the ceramic pipe and may not sufficiently close the gap.

Disclosure of Invention

An object of the present invention is to provide a heat treatment apparatus capable of suppressing leakage of an atmospheric gas from a boundary between adjacent ones of a plurality of divided muffle furnaces.

(1) The present invention relates to a heat treatment apparatus, comprising: a ceramic muffle furnace in which a heat treatment space for heat treatment of a workpiece is formed; and a metal cover that covers the muffle furnace, wherein the muffle furnace is divided into a plurality of parts, and the plurality of divided muffle furnaces are arranged so as to connect the heat treatment spaces, and the cover includes: a main cover that covers a boundary of an adjacent one of the plurality of divided muffle furnaces; and a sub-cover which frames the plurality of main covers.

According to the above configuration, the muffle divided into a plurality of parts is covered with the main cover and the sub cover. That is, the cover is divided into a main cover and a sub cover, and the area of each single cover is reduced. Therefore, compared to the case where the cover is not divided, the deformation of the main cover and the sub cover due to heat can be suppressed. Therefore, the main cover can be prevented from floating from the muffle furnace, and leakage of the atmosphere gas from the boundary to the outside of the muffle furnace or intrusion of the outside air into the muffle furnace can be prevented. The cover has a sub-cover that connects a plurality of main covers. Therefore, the main cover is pressed from the outside by the sub cover. This can further suppress the main cover from floating from the muffle furnace.

(2) Preferably, at least 1 of said main shrouds covers a plurality of said borders.

With this configuration, the number of the entire covers can be reduced as compared with the case where 1 main cover is disposed on 1 boundary.

(3) Preferably, the heat treatment apparatus includes a holding mechanism for restricting relative movement between the main cover and the sub cover.

With this configuration, the main cover and the sub cover can be prevented from being overlapped and separated.

According to the present invention, leakage of the atmosphere gas from the boundary between the adjacent ones of the plurality of divided muffle furnaces can be suppressed.

Drawings

Fig. 1 is a schematic view of a heat treatment apparatus according to embodiment 1 of the present invention.

Fig. 2 isbase:Sub>A sectional view taken along linebase:Sub>A-base:Sub>A of fig. 1.

FIG. 3 is a cross-sectional view of the muffle and hood taken along line B-B of FIG. 2.

Fig. 4 is a schematic perspective view showing the muffle and the cover.

Fig. 5 (a) is a cross-sectional view of the cover of the portion C of fig. 3, and fig. 5 (b) is a view of the portion (a) of fig. 5 in the direction D.

Fig. 6 is a sectional view of the cover of the portion E of fig. 3.

Fig. 7 is a cross-sectional view of the muffle and hood of section F of fig. 2.

Fig. 8 is a sectional view showing a cover according to embodiment 2 of the present invention.

Fig. 9 is a sectional view showing a holding mechanism according to embodiment 3 of the present invention.

Description of the reference symbols

10: a continuous heat treatment furnace; 11: a muffle furnace; 30: a cover; 31: a main cover; 32: a sub-cover; 40: dividing the body; 50: a holding mechanism; k1: a boundary; k2: a boundary; s: a heat treatment space; w: a workpiece; x: and (4) the conveying direction.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

Fig. 1 is a schematic view of a heat treatment apparatus according to an embodiment of the present invention. Fig. 2 isbase:Sub>A sectional view taken along linebase:Sub>A-base:Sub>A of fig. 1. FIG. 3 is a cross-sectional view of the muffle taken along line B-B of FIG. 2.

The heat treatment apparatus of the present embodiment is a continuous heat treatment furnace 10. The continuous heat treatment furnace 10 performs heat treatment while sequentially conveying a plurality of workpieces W. In the following description, the conveying direction of the workpiece W is denoted by reference numeral X, the width direction of the muffle 11 perpendicular to the conveying direction X of the workpiece W is denoted by reference numeral Y, and the vertical direction perpendicular to the directions X and Y is denoted by reference numeral Z.

The continuous heat treatment furnace 10 includes a muffle 11, a conveying device 12, a heat insulating wall 13, a heating device 14, a gas supply pipe 15, a hood 30, and the like.

The muffle furnace 11 is formed in a cylindrical shape and has a heat treatment space S therein. The muffle 11 is formed long in the conveyance direction X of the workpiece W, and the heat treatment space S also extends in the same direction X. Therefore, the workpiece W is conveyed in the longitudinal direction of the muffle 11. In the following description, the muffle 11 may be denoted by a reference numeral X in the longitudinal direction.

The muffle 11 has a bottom 21, a pair of side walls 22, and a top 23. The space surrounded by the bottom portion 21, the side wall portions 22, and the ceiling portion 23 becomes a heat treatment space S.

The bottom 21 of the muffle 11 has a flat upper surface 21a. The pair of side walls 22 linearly extend upward from both ends of the bottom portion 21 in the width direction Y of the muffle 11. The top portion 23 is provided so as to straddle the upper end portions of the pair of side wall portions 22.

The muffle 11 of the present embodiment has a side wall 22 and a ceiling 23 that are integrated, and these are formed separately from the bottom 21. The lower ends of the pair of side wall portions 22 contact the upper surface 21a of the bottom portion 21. The muffle 11 of the present embodiment is made of ceramic, which is a non-metal heat-resistant material. Ceramics are non-metal/inorganic solid materials, and correspond to materials other than metal materials such as iron, aluminum, and copper, and organic materials such as plastics and wood. More specifically, the ceramics include old ceramics such as ceramics, refractories (refractory bricks), glass, and cement, and new ceramics (fine ceramics).

The muffle 11 is divided into a plurality of parts. Specifically, the muffle 11 is composed of a plurality of segments 40, and the plurality of segments 40 are arranged in the conveying direction X of the workpiece W. The divided body 40 is composed of a lower divided body 11A constituting the bottom portion 21 and an upper divided body 11B constituting the side wall portion 22 and the top portion 23.

As shown in fig. 1, a cylindrical or gate-shaped metal chamber 18 is connected to both end portions of the muffle 11 in the conveying direction X of the workpiece W, in other words, to regions of the muffle 11 where the temperatures of the inlet portion and the outlet portion of the workpiece W are relatively low.

The conveying device 12 conveys the workpiece W in the longitudinal direction X of the muffle 11 in the heat treatment space S in the muffle 11. In the present embodiment, a plurality of (e.g., 3) conveying devices 12 are arranged at intervals in the width direction Y of the muffle 11. The conveying device 12 of the present embodiment is a chain conveyor having a conveying chain 12a and sprockets 12b and 12 c. The chain 12a moves on a rail 21b provided on the upper surface 21a of the bottom 21 of the muffle 11. The chain 12a is wound around the drive sprocket 12b and the driven sprocket 12c and moves in the longitudinal direction X in the muffle 11. The chain 12a is provided with a tray T on which the workpiece W is placed. In the present embodiment, a plurality of trays T are stacked with a gap in the vertical direction Z, and a workpiece W is placed on each tray T. The conveying device 12 may be a belt conveyor, a roller conveyor, or other types of devices.

As shown in fig. 2, the heat insulating wall 13 includes a lower heat insulating wall 13a disposed below the muffle 11, side heat insulating walls 13b disposed on both sides of the muffle 11 in the width direction Y, and an upper heat insulating wall 13c disposed above the muffle 11. The muffle 11 is disposed in a space surrounded by the lower heat insulating wall 13a, the side heat insulating wall 13b, and the upper heat insulating wall 13c. The heat insulating wall 13 can be formed of a heat insulating material formed into a thick plate shape using ceramic fibers, for example.

The heating device 14 includes a heater disposed below the muffle 11. The heating device 14 heats the muffle 11 from the outside, and raises the temperature of the heat treatment space S in the muffle 11 to a predetermined temperature. As the heating device 14, a resistance heating type device or a gas combustion heating type device can be used. The arrangement and form of the heating device 14 are not particularly limited, and may be, for example, arranged on the side of the muffle 11 in the width direction Y or above the muffle 11. The heating device 14 may be embedded in the heat insulating wall 13.

The gas supply pipe 15 supplies gas into the muffle 11 to generate a predetermined atmosphere. In the present embodiment, for example, nitrogen gas is used. The gas supply pipe 15 is disposed along the upper surface 21a of the bottom 21 of the muffle 11. Specifically, the gas supply pipe 15 is placed on the upper surface 21a of the bottom 21, and is supported from below by the upper surface 21a.

The gas supply pipe 15 extends in the conveyance direction X of the workpiece W. The gas supply pipes 15 are provided respectively on both outer sides of the conveying devices 12 in the width direction Y of the muffle 11 and between adjacent conveying devices 12. Therefore, in the present embodiment, a total of 4 gas supply pipes 15 are provided in the muffle furnace 11. A gas ejection port for ejecting gas is formed on the outer peripheral surface of the gas supply pipe 15. The plurality of discharge ports are formed at intervals in the conveyance direction X of the workpiece W. The gas supply pipes 15 disposed on both outer sides of the conveying device 12 in the width direction Y of the muffle 11 are formed with discharge ports for discharging gas obliquely upward toward the workpiece W positioned on the inner side in the same direction Y. Each of the gas supply pipes 15 disposed between the adjacent conveying devices 12 is formed with a gas discharge port so as to discharge gas obliquely upward toward the workpieces W disposed on both sides in the width direction Y of the muffle 11.

The gas introduction pipe 16 is disposed adjacent to one gas supply pipe 15 of the 2 gas supply pipes 15 disposed between the adjacent conveying devices 12. In the present embodiment, 2 gas introduction pipes 16 are disposed adjacent to both sides of the gas supply pipe 15 in the width direction Y of the muffle 11. The gas introduction pipe 16 is used to introduce the gas in the muffle 11 and send the gas out of the muffle 11 in order to detect the concentration of a predetermined gas in the muffle 11.

Fig. 4 is a schematic perspective view showing the muffle and the cover.

As shown in fig. 2 to 4, the cover 30 covers the muffle 11 from the outside. Specifically, the cover 30 covers the side wall portion 22 and the ceiling portion 23 of the muffle 11 from the outside. Therefore, the cover 30 is formed in a shape of "12467with the lower part opened by a portion 30a covering the side wall portion 22 and a portion 30b covering the top portion 23. The cover 30 is made of a metal having heat resistance, for example, a nickel alloy such as inconel 601 ("inconel" is a registered trademark), or stainless steel such as SUS310, SUS 304.

The cover 30 includes a main cover 31 and a sub-cover 32. A plurality of main covers 31 and a plurality of sub covers 32 are provided. The main covers 31 and the sub covers 32 are alternately arranged in the conveying direction X of the workpiece W. Therefore, the plurality of main covers 31 are disposed at intervals in the conveying direction X of the workpiece W, and the plurality of sub covers 32 are disposed at intervals in the conveying direction X of the workpiece W. The interval between the main covers 31 arranged in the conveying direction X of the workpiece W is set to be an interval that does not interfere with each other when the main covers 31 thermally expand. The intervals between the sub-hoods 32 arranged in the conveyance direction X of the workpiece W are set to be intervals that do not interfere with each other when the sub-hoods 32 thermally expand.

Each main cover 31 covers the boundary K1 of the adjacent divided bodies 40 of the muffle 11. Specifically, the main cover 31 has a length in the same direction X slightly longer than the length of the divided bodies 40 in the conveying direction X of the workpiece W, and spans 2 boundaries K1 located on both sides of each divided body 40, and covers the 2 boundaries K1 from the outside. Therefore, the main cover 31 suppresses leakage of the atmospheric gas in the muffle 11 from the boundary K1 of the split body 40 or intrusion of the external gas into the muffle 11.

Each sub-cover 32 is disposed so as to straddle the main covers 31 adjacent to each other in the conveyance direction X of the workpiece W. In other words, the sub-cover 32 is disposed across the adjacent main covers 31, bridging the two main covers 31. Each sub-cover 32 covers the end of the adjacent main cover 31 from the outside. Therefore, the main cover 31 and the sub cover 32 overlap each other at their ends in the conveying direction X of the workpiece W. The sub-cover 32 is formed to be larger than the main cover 31 by one turn, and is disposed apart from the outer surface of the muffle 11 by the thickness of the main cover 31.

The sub cover 32 presses the main cover 31 by covering an end portion of the main cover 31 from the outside. In particular, a portion of the main cover 31 covering the top 23 of the muffle 11 is pressed from above by the weight of the sub-cover 32. Thus, the sub-cover 32 becomes a "weight" for the main cover 31, and can suppress the main cover 31 from floating from the muffle 11. Further, a portion of the main cover 31 covering the side wall portion 22 of the muffle 11 is pressed by the sub cover 32 from the outside in the width direction Y of the muffle 11. This can suppress the main cover 31 from expanding outward or floating from the muffle 11 in the width direction Y of the muffle 11. Therefore, the sub cover 32 can enhance the effect of the main cover 31 in closing the boundary K1 of the divided body 40, and can effectively suppress leakage of the atmospheric gas from the boundary K1 and intrusion of the external gas. The sub-hood 32 closes the space between the adjacent main hoods 31, thereby further suppressing the intrusion of the outside air into the muffle 11.

The main cover 31 and the sub cover 32 cover the entire muffle 11 from the outside, thereby suppressing heat of the muffle 11 from escaping to the outside. In addition, the main hood 31 and the sub-hood 32 suppress thermal unevenness of the whole muffle 11. The main cover 31 and the sub-cover 32 are made of metal and have a property of adsorbing oxygen. Therefore, for example, when the atmosphere in the muffle 11 is to be maintained in a low oxygen state by filling the inside and outside of the muffle 11 with a predetermined gas such as nitrogen gas, the atmosphere in the muffle 11 can be easily maintained in a low oxygen state because oxygen can be adsorbed by the main cover 31 and the sub-cover 32.

Since the cover 30 is configured to be divided into the main cover 31 and the sub-cover 32 and the volume of each single cover is reduced, the deformation of the covers 31 and 32 due to heat can be reduced as compared with the case where the entire cover is configured by 1 cover. Therefore, the main cover 31 can be prevented from floating from the boundary K1 of the divided body 40. Similarly, since the deformation of the sub cover 32 due to heat can be reduced, the sub cover 32 can be prevented from floating from the main cover 31, and the effect of the sub cover 32 pressing the main cover 31 can be ensured.

The main cover 31 and the sub cover 32 have substantially the same length in the conveying direction X of the workpiece W. Therefore, the amounts of thermal deformation of the two are substantially the same. That is, it is assumed that the ranges in which the main cover 31 and the sub-cover 32 may warp and float due to heat are also substantially the same, and therefore the amount of overlap of the covers 31 and 32 required for the sub-cover 32 to press the main cover 31 can be easily controlled. Further, the gap between the covers 31 and 32 is also suppressed, and the gap between the muffle 11 and the cover 30 can be suppressed from being generated.

Fig. 5 (a) is a cross-sectional view of the cover of the portion C of fig. 3, and fig. 5 (b) is a view of the portion (a) of fig. 5 in the direction D.

The main cover 31 and the sub cover 32 restrict relative movement of the workpiece W in the conveying direction X. Specifically, a rod-shaped protrusion 51 is provided on an outer surface of an end portion of the main cover 31 so as to protrude upward. A hole 52 into which the protrusion 51 is inserted is formed at an end of the sub-cover 32. The hole 52 is a long hole that is long in the conveyance direction X of the workpiece W. In the present embodiment, the protrusion 51 and the hole 52 are provided in the portion 30b of the main hood 31 and the sub-hood 32 that covers the top 23 of the muffle 11. However, the projections 51 and the holes 52 may be provided in the portions 30a of the main cover 31 and the sub cover 32 that cover the side wall portions 22 of the muffle 11.

When the main cover 31 and the sub cover 32 are thermally elongated in the conveying direction X of the workpiece W, the relative movement is permitted within the range of the length of the hole 52, and the relative movement of the workpiece W in the conveying direction X is restricted within the range exceeding the length of the hole 52. By restricting the relative movement, the main cover 31 and the sub-cover 32 are kept in a state of being overlapped with each other, and the main cover 31 is kept in a state of covering the boundary K1 of the adjacent divided bodies 40. Therefore, leakage of the atmosphere gas from the boundary K1 and the like is suppressed. Here, the projection 51 and the hole 52 constitute a holding mechanism 50, and the holding mechanism 50 holds the state where the main cover 31 covers the boundary K1 of the adjacent split body 40. Further, the holding mechanism 50 also holds the state in which the main cover 31 and the sub-cover 32 cover the muffle 11 from the outside, and thus can suppress the heat of the muffle 11 from escaping to the outside.

The length of the hole 52 of the holding mechanism 50 (the relative movement amount between the main cover 31 and the sub-cover 32) is set so as to hold the state in which the main cover 31 and the sub-cover 32 are overlapped and the state in which the main cover 31 covers the boundary K1, depending on the magnitude of the amount of overlap between the main cover 31 and the sub-cover 32, the thermal expansion of the main cover 31 and the sub-cover 32, and the like.

Fig. 6 is a sectional view of the cover of the portion E of fig. 3.

One end of the main cover 31 disposed at the end in the conveying direction X of the workpiece W is connected to the sub-cover 32 via the holding mechanism 50, and the other end is fixed to the metal chamber 18 connected to the inlet and outlet of the muffle 11. Specifically, a bar-shaped protrusion 53 is provided to protrude upward from the outer surface of the metal cavity 18, and a hole 54 into which the protrusion 53 is inserted is formed at the end of the main cover 31. The hole 54 is a circular hole having an inner diameter slightly larger than the diameter of the projection 53. Therefore, the main cover 31 formed with the hole 54 is substantially fixed to the metal cavity 18. By fixing the main covers 31 disposed at both ends in the conveying direction X of the workpiece W in the same direction X in this manner, the amount of movement of the other main cover 31 and the sub cover 32 disposed therebetween can be restricted, and the main cover 31 and the sub cover 32 can be prevented from being overlapped and separated. Further, the movement of the covers 31 and 32 is accumulated, thereby preventing the main covers 31 from deviating from the boundary K1 of the segment 40.

Fig. 7 is a cross-sectional view of the muffle and hood of section F of fig. 2.

As shown in fig. 7, in the main cover 31, a portion 30a covering the side wall portion 22 of the muffle 11 covers a boundary K2 between the side wall portion 22 and the bottom portion 21 from the outside. Therefore, leakage of the atmospheric gas from the boundary K2 or intrusion of the external gas from the boundary K2 can be suppressed.

Fig. 8 is a sectional view showing a cover according to embodiment 2 of the present invention.

In the present embodiment, each of the plurality of main covers 31 covers one boundary K1 of the adjacent divided bodies 40. Therefore, the length of each main cover 31 in the conveying direction X of the workpiece W is shorter than that of the main cover 31 of embodiment 1. Further, the sub-cover 32 overlapping the main cover 31 is narrowed in the interval between the adjacent portions in the conveying direction X of the workpiece W.

The present embodiment also provides the same operational advantages as those of the above-described embodiment. In the present embodiment, each of the plurality of main covers 31 covers one boundary K1 of the adjacent divided bodies 40. Therefore, the main cover 31 only needs to cover the periphery of at least one boundary K1, and therefore, the length of the workpiece W in the conveying direction X can be made shorter than that in embodiment 1. Therefore, the main cover 31 can have a smaller area than the main cover 31 of embodiment 1, and the amount of deformation due to heat can be reduced as compared with the main cover 31 of embodiment 1. Therefore, the main cover 31 can be further suppressed from floating from the split body 40, and leakage of the atmosphere gas from the boundary K1 to the outside of the muffle 11 or intrusion of the outside air into the muffle 11 can be suppressed.

Fig. 9 is a sectional view showing a holding mechanism according to embodiment 3 of the present invention.

In the present embodiment, the form of the holding mechanism 50 is different from the above-described embodiments.

In the present embodiment, a bar-shaped protrusion 55 is provided on the inner surface of the end portion of the sub-cover 32 so as to protrude downward. The projection amount of the projection 55 is smaller than the thickness of the main cover 31. A groove 56 into which the protrusion 55 is inserted is formed on the outer surface of the end of the main cover 31. The groove 56 is a long groove long in the conveyance direction X of the workpiece W.

Therefore, in the present embodiment, the relative movement of the main cover 31 and the sub-cover 32 in the conveyance direction X of the workpiece W is also restricted within the range of the length of the groove 56, and the main cover 31 and the sub-cover 32 are maintained in a state of being overlapped, and the main cover 31 is maintained in a state of covering the boundary K1.

In the present embodiment, the groove 56 may be changed to a hole penetrating the main cover 31. In embodiment 1 shown in fig. 5, the projection amount of the projection 51 can be made smaller than the thickness of the sub cover 32, and the hole 52 can be changed to a groove (long groove) formed in the lower surface of the sub cover 32.

The continuous heat treatment furnace 10 of the embodiment described above includes: a non-metal muffle 11 in which a heat treatment space S for heat treatment of the conveyed workpiece W is formed; and a metal cover 30 covering the outside of the muffle 11. The muffle 11 has at least 3 divided bodies 40 (for example, 3 divided bodies arranged in a row in fig. 3 and 8; hereinafter, these are also referred to as "1 st divided body", "2 nd divided body", and "3 rd divided body"). These 1 st to 3 rd divided bodies 40 are arranged in the conveying direction X of the workpiece W. The cover 30 has: a main cover (hereinafter, also referred to as "1 st main cover") 31 that covers a boundary K1 between the 1 st segment 40 and the 2 nd segment 40; and a main cover (hereinafter, also referred to as "2 nd main cover") 31 that covers a boundary K1 between the 2 nd divided body 40 and the 3 rd divided body 40. With this configuration, the boundaries K1 of the divided body 40 are covered with the main covers 31. Therefore, the cover 30 is divided into a plurality of main covers 31, and the area of each single cover is reduced. Therefore, compared to the case where the cover 30 is not divided, the deformation of each main cover 31 due to heat can be suppressed. This can suppress the main covers 31 from floating from the muffle 11, and can suppress leakage of the atmosphere gas from the boundary K1 to the outside of the muffle 11 or intrusion of the outside air into the muffle 11.

In the above embodiment, the cover 30 is disposed across the 1 st main cover 31 and the 2 nd main cover 31, and has the sub cover 32 overlapping the 1 st main cover 31 and the 2 nd main cover 31 from the outside. Therefore, the 1 st and 2 nd main covers 31 are pressed by the sub-covers 32 from the outside, and the boundary K1 of the adjacent divided bodies 40 can be covered by the 1 st and 2 nd main covers 31. In particular, the 1 st and 2 nd main covers 31 are pressed from above by the weight of the sub cover 32. Therefore, the sub-cover 32 serves as a weight for the 1 st and 2 nd main covers 31, and the 1 st and 2 nd main covers 31 are prevented from floating from the muffle 11.

In the above embodiment 1, the muffle 11 further includes the divided body 40 (hereinafter also referred to as "4 th divided body") arranged in line with the 3 rd divided body 40 in the conveying direction X of the workpiece W, and the 2 nd main cover 31 further covers the boundary K1 between the 3 rd divided body 40 and the 4 th divided body 40. In other words, the cover 30 has the 2 nd main cover 31 covering the plurality of boundaries K1. Therefore, the number of the entire covers 30 can be reduced as compared with the case where the 2 nd main cover 31 covers only the 1 boundary K1.

In the above embodiment, the continuous heat treatment furnace 10 has the holding mechanism 50, and the holding mechanism 50 restricts the relative movement of the 1 st main hood 31 and the 2 nd main hood 31 and the sub-hood 32 spanning therebetween. This can prevent the 1 st and 2 nd main covers 31 and the sub-covers 32 from being overlapped and separated. Further, by providing the holding mechanism 50, the 1 st and 2 nd main covers 31 can be prevented from deviating from the boundary K1. Therefore, leakage of the atmospheric gas from the muffle 11 or intrusion of the external gas into the muffle 11 can be suppressed.

The present invention is not limited to the above-described embodiments, and can be appropriately modified within the scope of the invention described in the claims.

For example, the main cover 31 may have a length in the conveyance direction X of the workpiece W that covers 3 or more boundaries K1. Further, the cover 30 may have a plurality of types of main covers 31 that are different in the number of boundaries K1 that can be covered. For example, for reasons of manufacturing such as ease of manufacturing the muffle 11, if the split bodies 40 are formed to be small and a plurality of the split bodies 40 are arranged, it is more effective to arrange a plurality of types of main covers 31 in combination as described above.

For example, the side wall 22, the ceiling 23, and the bottom 21 of the muffle 11 are separate bodies, but the present invention is not limited thereto. For example, the muffle 11 may be integrally formed. The muffle 11 may have a side wall 22 and a bottom 21 that are integral with each other, and a top 23 that is separate from each other. The muffle 11 may be vertically divided by an intermediate portion of the side wall portion 22 in the vertical direction Z.

The cover 30 covers the side wall 22 and the ceiling 23 of the muffle 11, but may cover either. In addition, the cover 30 may cover the bottom 21.

Claims (3)

1. A heat treatment apparatus, comprising:

a ceramic muffle furnace in which a heat treatment space for heat treatment of a workpiece is formed; and

a metal cover covering the muffle,

the muffle furnace is divided into a plurality of muffle furnaces, the plurality of muffle furnaces are arranged in a manner of connecting the heat treatment spaces,

it is characterized in that the preparation method is characterized in that,

the cover includes:

a main cover that covers a boundary of an adjacent one of the plurality of divided muffle furnaces; and

and a sub-cover which frames the plurality of main covers.

2. The thermal processing device of claim 1,

at least 1 of the main covers a plurality of the boundaries.

3. The heat treatment apparatus according to claim 1 or 2,

the heat treatment apparatus includes a holding mechanism for restricting relative movement between the main cover and the sub cover.

Images