Heat treatment furnace

Abstract

To suppress atmospheric gas from staying in a furnace.SOLUTION: A heat treatment furnace according to the present invention comprises: a furnace body having an inlet, an outlet, and a heat treatment space for heat-treating a plurality of objects to be treated; a plurality of transported parts arranged in a line in a front direction, on which the plurality of objects to be treated can be placed with gaps between the objects to be treated in a right-left direction; a pusher for pressing the transported parts in the forward direction; and a plurality of air supply pipes arranged in a line in the right-left direction, each of which has an air supply port for supplying atmospheric gas into the heat treatment space. Here, the transported parts are arranged between adjacent air supply pipes in the right-left direction. The air supply ports of the air supply pipes are arranged to supply atmospheric gas to the objects to be treated. The heat treatment furnace has a plurality of exhaust ports for discharging the atmospheric gas in the heat treatment space to the outside of the furnace body. The exhaust ports are arranged directly above the gaps between the plurality of objects to be treated arranged in the right-left direction on the transported parts when the furnace body is viewed along the front direction.SELECTED DRAWING: Figure 9

Description

[Technical field]

[0001] The technology disclosed in this specification relates to a heat treatment furnace. [Background technology]

[0002] Patent Document 1 discloses a heat treatment furnace for heat treating a plurality of objects to be treated. The heat treatment furnace includes a furnace body with an inlet and an outlet, a conveying plate on which a pusher presses the plurality of objects to be treated stacked vertically from the inlet to the outlet, and a plurality of air supply pipes having an air supply port for supplying atmospheric gas into the heat treatment space of the furnace body. A plurality of exhaust ports are formed in the upper wall of the furnace body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-162246 Summary of the Invention [Problem to be solved by the invention]

[0004] When the objects to be treated are stacked vertically on the conveying plate and arranged side by side in the horizontal direction, many objects to be treated are placed inside the furnace body. Therefore, the flow of the atmospheric gas inside the furnace body is affected by the objects to be treated. In a heat treatment furnace as in Patent Document 1, multiple exhaust ports are arranged near the left end (i.e., near the left side wall extending in the conveying direction) and near the right end (i.e., near the right side wall extending in the conveying direction) of the upper wall of the furnace body. Therefore, exhaust ports and air inlets are not arranged in consideration of the loading state of the objects to be treated. This makes it easier for the atmospheric gas to stagnate inside the furnace body.

[0005] This specification discloses a technique capable of suppressing atmospheric gas from stagnation inside a furnace body. [Means for solving the problem]

[0006] In a first aspect of the technology disclosed in the present specification, the heat treatment furnace includes a furnace body having an inlet, an outlet, and a heat treatment space for heat-treating a plurality of workpieces, a plurality of transported parts arranged in a line in a forward direction on which the plurality of workpieces can be placed while being stacked vertically and arranged with gaps in a left-right direction perpendicular to the vertical direction, a pusher that presses the transported parts in the forward direction from the inlet of the furnace body toward the outlet, and a plurality of air supply pipes arranged in a line in the left-right direction, each of which has an air supply port for supplying atmospheric gas into the heat treatment space. The transported parts are arranged between the air supply pipes adjacent to each other in the left-right direction. The air supply ports of the air supply pipes are arranged to supply the atmospheric gas to the workpieces stacked vertically. The heat treatment furnace has a plurality of exhaust ports for discharging the atmospheric gas in the heat treatment space to the outside of the furnace body. The exhaust port is disposed directly above a gap between the plurality of workpieces arranged in the left-right direction on the transported portion when the furnace body is viewed along the front direction.

[0007] According to the above configuration, the atmospheric gas supplied from the air supply pipe to the heat treatment space passes between the workpieces stacked vertically and flows to the gaps between the workpieces arranged horizontally on the conveying plate. Next, the atmospheric gas flows upward through the gaps between the workpieces. Since the exhaust port is located directly above the gaps between the workpieces when the furnace body is viewed along the front direction, the atmospheric gas flows upward toward the exhaust port after flowing through the gaps between the workpieces. When gas is generated from the workpieces, the atmospheric gas flows toward the exhaust port together with the gas generated from the workpieces. Finally, the atmospheric gas is discharged from the exhaust port to the outside of the furnace body together with the gas generated from the workpieces. This makes it possible to suppress the atmospheric gas from stagnation in the furnace body. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a schematic cross-sectional view of a heat treatment furnace according to the first embodiment. [Diagram 2]2 is a front view of a plurality of objects to be processed placed on a transfer plate in the first embodiment. FIG. [Diagram 3] FIG. 2 is a horizontal cross-sectional view of the object to be treated in the first embodiment. [Figure 4] 4 is a schematic cross-sectional view of the heat treatment furnace taken along line IV-IV in FIG. [Diagram 5] FIG. 2 is a cross-sectional view showing an uppermost object to be processed and a first partition wall in the first embodiment. [Figure 6] 2 is a schematic cross-sectional view of the heat treatment furnace taken along line VI-VI in FIG. 1. [Figure 7] FIG. 2 is a horizontal cross-sectional view showing a part of the heat treatment furnace of the first embodiment. [Figure 8] FIG. 2 is a cross-sectional view showing the object to be processed and the second partition wall disposed at the leftmost end (on the second partition wall side) in the first embodiment. [Figure 9] 2 is a schematic cross-sectional view showing a transfer plate, an air supply pipe arranged around the transfer plate, and a furnace body in the heat treatment furnace of the first embodiment. FIG. [Figure 10] FIG. 2 is a block diagram of a heater, a pusher, an adjusting valve, and a control device according to the first embodiment. [Figure 11] FIG. 11 is a schematic side view of the workpiece and the air supply pipe when the notch in the workpiece and the air supply pipe do not overlap in the left-right direction in the first embodiment. [Figure 12] FIG. 11 is a schematic side view of the workpiece and the air supply pipe when the cutout in the workpiece and the air supply pipe overlap in the left-right direction in the first embodiment. [Figure 13] 1 is a schematic cross-sectional view showing a furnace body, a workpiece placed in an internal space of the furnace, and an air supply pipe in a heat treatment furnace of a first embodiment. [Figure 14] FIG. 6 is a horizontal cross-sectional view showing a part of a heat treatment furnace according to a second embodiment. [Figure 15] FIG. 6 is a horizontal cross-sectional view showing a part of a heat treatment furnace according to a second embodiment. [Figure 16] 10 is a schematic cross-sectional view showing a furnace body, a workpiece placed in a heat treatment space, and a heater in a heat treatment furnace of a third embodiment. FIG. [Figure 17]13 is a schematic cross-sectional view showing a furnace body, a workpiece placed in an internal space of the furnace, and an air supply pipe in a heat treatment furnace of a fourth embodiment. FIG. [Figure 18] 13 is a schematic cross-sectional view showing a transfer plate, an air supply pipe disposed around the transfer plate, and a furnace body in a heat treatment furnace of a fourth embodiment. FIG.

[0009] The main features of the embodiments described below are listed below. Note that the technical elements described below are independent technical elements that exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing.

[0010] In a second aspect of the technology disclosed in this specification, in the first aspect described above, the width of the exhaust port in the left-right direction is 1 to 3 times the width of the gap in the left-right direction between the multiple workpieces arranged in the left-right direction. According to the above configuration, even when the atmospheric gas flows through the gaps (gaps in the left-right direction) between the multiple workpieces and then spreads to the right or left toward the upper wall, the atmospheric gas can be discharged from the exhaust port to the outside of the furnace body together with the gas generated from the workpieces. This makes it possible to further suppress the atmospheric gas from stagnation in the furnace body.

[0011] In a third aspect of the technology disclosed in the present specification, in the first or second aspect described above, the multiple air supply pipes are arranged side by side in the forward direction. The distance between adjacent air supply pipes in the forward direction is an integer multiple of the length of the transported part in the forward direction. In a heat treatment furnace in which a pusher is generally used, when the pusher presses the transported part once, the transported part moves a distance equivalent to the length of the transported part in the forward direction. With the above configuration, atmospheric gas can be uniformly supplied to the workpiece on the transported part.

[0012] In a fourth aspect of the technology disclosed in the present specification, in any one of the first to third aspects, the heat treatment furnace includes an adjustment valve that allows the atmospheric gas to be supplied from the air inlet when the adjustment valve is open and prohibits the atmospheric gas from being supplied from the air inlet when the adjustment valve is closed, and a control device that controls the opening and closing of the adjustment valve. The workpiece is located on top of the workpiece and has a notch that communicates the inside and outside of the workpiece. The control device opens the adjustment valve when the air inlet pipe overlaps with the notch in the left-right direction. According to the above configuration, when the air inlet pipe overlaps with the notch in the left-right direction, the atmospheric gas is supplied from the air inlet of the air inlet pipe. This allows the atmospheric gas to be efficiently supplied to the inside of the workpiece.

[0013] In a fifth aspect of the technology disclosed in the present specification, in any one of the first to fourth aspects, the heat treatment furnace includes a plurality of regulating valves, the regulating valves switching the amount of the atmospheric gas supplied from the air supply port between a first amount of air supply and a second amount of air supply different from the first amount of air supply, and a control device that controls the plurality of regulating valves. In the air supply pipes adjacent to each other in the left-right direction, the air supply port of one of the air supply pipes faces the air supply port of the other of the air supply pipes. When the control device switches the amount of air supply supplied from the air supply port of the one of the air supply pipes to the first amount of air supply, the control device switches the amount of air supply supplied from the air supply port of the other of the air supply pipes to the second amount of air supply. According to the above configuration, the atmospheric gas in the heat treatment space is agitated, and the concentrations of the atmospheric gas and the gas components generated from the workpiece can be made uniform in the heat treatment space.

[0014] In a sixth aspect of the technology disclosed in the present specification, in any one of the first to fifth aspects, the heat treatment space has a plurality of furnace spaces defined by a plurality of first partition walls arranged in the front direction and arranged above the workpiece. Each of the plurality of exhaust ports is arranged in each of the plurality of furnace spaces. With the above configuration, it is possible to suppress the atmospheric gas from stagnation in each furnace space.

[0015] In a seventh aspect of the technique disclosed in the present specification, the heat treatment furnace according to the sixth aspect further includes a plurality of guide rails, the transported part being disposed between the guide rails adjacent to each other in the left-right direction, the guide rails extending in the forward direction and guiding the transported part in the forward direction, and a plurality of second partition walls, the second partition walls extending from the guide rails to the first partition wall. According to the above configuration, it is possible to suppress the movement of the atmospheric gas supplied from the air supply pipe between adjacent furnace spaces.

[0016] In an eighth aspect of the technique disclosed in the present specification, in the seventh aspect, the distance between the second partition wall and the workpiece in the left-right direction is 10 mm or more and 30 mm or less. With the above configuration, it is possible to suppress contact between the second partition wall and the workpiece, while suppressing movement of the atmospheric gas supplied from the air supply pipe between adjacent furnace spaces.

[0017] In a ninth aspect of the technology disclosed in the present specification, in any one of the sixth to eighth aspects, in each of the plurality of furnace spaces, the distance between the exhaust port and the air supply pipe in the forward direction is longer than the length of the transported part in the forward direction. With the above configuration, the contact time between the atmospheric gas and the workpiece in each furnace space can be increased.

[0018] In a tenth aspect of the technique disclosed in the present specification, in any one of the sixth to ninth aspects, the distance between the first partition and the workpiece is 10 mm or more and 30 mm or less. With the above configuration, it is possible to suppress contact between the first partition and the workpiece, while suppressing atmospheric gas from passing between the first partition and the workpiece.

[0019] In an eleventh aspect of the technology disclosed in the present specification, in any one of the first to tenth aspects, the heat treatment furnace further includes a temperature rise heater and a temperature retention heater arranged in the heat treatment space. The heat treatment space has a plurality of furnace spaces arranged side by side in the forward direction. The plurality of furnace spaces include a temperature rise space in which the temperature rise heater is arranged and which communicates with the entrance, and a temperature retention space in which the temperature retention heater is arranged and which communicates with the temperature rise space. The exhaust port is arranged in the temperature rise space. According to the above configuration, the atmospheric gas heated in the temperature retention space and the gas generated from the workpiece flow into the temperature rise space, heating the temperature rise space. As a result, the amount of heat generated by the temperature rise heater can be reduced compared to a configuration in which the atmospheric gas and the gas generated from the workpiece do not flow from the temperature retention space into the temperature rise space.

[0020] In a twelfth aspect of the technique disclosed in the present specification, in any one of the first to eleventh aspects, the air intake pipe is made of ceramics. According to the above configuration, the heat resistance of the air intake pipe is higher than that of a configuration in which the air intake pipe is made of a material other than ceramics. This makes it possible to prevent the air intake pipe from being damaged by heat in a heat treatment furnace used under high temperature conditions. Also, for example, in a configuration in which the air intake pipe is made of metal, metal may be mixed into the workpiece. This reduces the quality of the workpiece. According to the above configuration, it is possible to prevent the occurrence of a reduction in the quality of the workpiece due to the inclusion of metal.

[0021] In a thirteenth aspect of the technology disclosed in the present specification, in any one of the first to twelfth aspects, the heat treatment furnace further includes a supply pipe connected to each of the plurality of air supply pipes and supplying the atmospheric gas to the plurality of air supply pipes. The supply pipe passes through a wall of the furnace body. According to the above configuration, the atmospheric gas is heated by the furnace body when it flows through the supply pipe. This makes it possible to suppress a decrease in the temperature of the heat treatment space when the atmospheric gas is supplied from the air supply pipe to the heat treatment space.

[0022] (First Example) The heat treatment furnace 10 of the first embodiment shown in Fig. 1 heat-treats the workpiece 2. In the following, the longitudinal direction of the heat treatment furnace 10 is referred to as the front-rear direction, the direction perpendicular to the front-rear direction is referred to as the left-right direction, and the direction perpendicular to the front-rear direction and the left-right direction is referred to as the up-down direction. The front direction is the direction from the carry-in entrance 46a toward the carry-out exit 48a, and the rear direction is the direction from the carry-out exit 48a toward the carry-in entrance 46a.

[0023] As shown in FIG. 2, the workpiece 2 includes a sagger 4 and a workpiece body 6 (see FIG. 3). The sagger 4 has a box shape that is a substantially rectangular parallelepiped. The sagger 4 has a plurality of (four in this embodiment) notches 5. The notches 5 are located at the upper part of the sagger 4. As shown in FIG. 3, each of the four notches 5 is disposed on each of the four side walls 4a of the sagger 4. The widths W1 of the four side walls 4a are the same. Two of the notches 5 face each other in the front-rear direction, and the other two notches 5 face each other in the left-right direction. The notches 5 communicate with the inside and outside of the sagger 4. The width W2 of the notches 5 is 30% or more and 70% or less of the width W1 of the side wall 4a. In this embodiment, the width W2 is 40% of the width W1. The width W2 may be greater than or equal to 30% and less than or equal to 60%.

[0024] The treatment object body 6 is placed inside the sagger 4. The treatment object body 6 is, for example, a raw material for a ceramic capacitor, or a positive electrode material and a negative electrode material for a lithium ion battery.

[0025] As shown in FIG. 1, the heat treatment furnace 10 includes a furnace body 12, a plurality of first partitions 14, a plurality of heaters 16, a guide portion 18 (see FIG. 2), a plurality of transported portions 20, a pusher 22, a plurality of second partitions 26 (see FIG. 6), a plurality of air supply pipes 28, a plurality of regulating valves 30 (see FIG. 9), a plurality of supply pipes 32 (see FIG. 9), and a control device 36 (see FIG. 10).

[0026] The furnace body 12 is a substantially rectangular heat-insulating structure extending in the front-rear direction. The furnace body 12 includes an upper wall 42, a lower wall 44, a furnace inlet wall 46, a furnace outlet wall 48, a right side wall 50 (see FIG. 4), and a left side wall 52 (see FIG. 4). The upper wall 42, the lower wall 44, the furnace inlet wall 46, the furnace outlet wall 48, the right side wall 50, and the left side wall 52 define an internal space 54 of the furnace body 12. The upper wall 42 and the lower wall 44 extend in the front-rear direction. The upper wall 42 is disposed above the lower wall 44. The furnace inlet wall 46 is connected to the rear end of the upper wall 42 and the rear end of the lower wall 44. The furnace inlet wall 46 has a loading port 46a penetrating the furnace inlet wall 46 in the front-rear direction. The internal space 54 is in communication with the outside of the furnace body 12 via the loading port 46a. For example, the internal space 54 communicates with a replacement chamber (not shown) disposed outside the furnace body 12 through the inlet 46a. The furnace outlet wall 48 is connected to the front end of the upper wall 42 and the front end of the lower wall 44. The furnace outlet wall 48 has an outlet 48a penetrating the furnace outlet wall 48 in the front-rear direction. The internal space 54 communicates with the outside of the furnace body 12 through the outlet 48a. For example, the internal space 54 communicates with a replacement chamber (not shown) disposed inside the furnace body 12 through the outlet 48a. The outlet 48a faces the inlet 46a in the front-rear direction. As shown in FIG. 4, the right side wall 50 and the left side wall 52 are disposed apart from each other in the left-right direction. The right side wall 50 faces the left side wall 52 in the left-right direction. The right side wall 50 and the left side wall 52 are connected to the upper wall 42, the lower wall 44, the furnace inlet wall 46 (see FIG. 1), and the furnace outlet wall 48 (see FIG. 1).

[0027] 1, the multiple first partition walls 14 are aligned in the front-rear direction. The first partition walls 14 extend downward from the upper wall 42. The multiple first partition walls 14 divide the internal space 54 into multiple spaces.

[0028] The internal space 54 includes a heat treatment space 58 and a cooling space 60. The heat treatment space 58 is defined by the upper wall 42, the lower wall 44, the furnace inlet wall 46, the right side wall 50 (see FIG. 4), the left side wall 52 (see FIG. 4), and a first partition wall 14 disposed at the boundary between the cooling space 60. The heat treatment space 58 is disposed at the rear of the furnace body 12. The heat treatment space 58 is divided into a plurality of in-furnace spaces 58a by the first partition wall 14. The plurality of in-furnace spaces 58a are arranged in the front-rear direction. The in-furnace spaces 58a adjacent to each other in the front-rear direction are connected to each other. A heater 16 is disposed in each of the plurality of in-furnace spaces 58a. When the heater 16 generates heat, the in-furnace space 58a (heat treatment space 58) is heated.

[0029] The cooling space 60 is disposed in the front part of the furnace body 12. The cooling space 60 is defined by the upper wall 42, the lower wall 44, the furnace outlet wall 48, the right side wall 50 (see FIG. 4), the left side wall 52 (see FIG. 4), and the first partition wall 14 disposed at the boundary with the heat treatment space 58. The cooling space 60 is in communication with the heat treatment space 58. A cooling pipe (not shown) is disposed in the cooling space 60. The cooling space 60 is cooled by water or air passing through the cooling pipe.

[0030] The guide section 18 is disposed in the heat treatment space 58 and the cooling space 60. As shown in Fig. 2, the guide section 18 includes a plurality of mounting rails 64 and a plurality of guide rails 66 (see Fig. 4).

[0031] The mounting rails 64 extend in the front-rear direction. As shown in Fig. 4, the multiple mounting rails 64 are arranged side by side in the left-right direction.

[0032] The guide rails 66 extend in the front-rear direction. The multiple guide rails 66 (four in this embodiment) are spaced apart in the left-right direction. Six mounting rails 64 are arranged between two adjacent guide rails 66 in the left-right direction. The upper surfaces of the guide rails 66 are arranged slightly above the upper surfaces of the mounting rails 64.

[0033] The plurality of conveyed parts 20 are arranged in the front-rear direction and in the left-right direction. As shown in FIG. 2, the conveyed part 20 has one or more conveying plates 20a (two in this embodiment). The two conveying plates 20a are arranged in the left-right direction. The conveying plate 20a has a flat plate shape. The conveying plate 20a can place a plurality of objects 2 to be processed on its upper surface. In this embodiment, six objects 2 to be processed are stacked vertically on the upper surface of the conveying plate 20a via a spacer 68. The object 2 to be processed on one of the two conveying plates 20a arranged in the left-right direction has a gap G1 between it and the object 2 to be processed on the other conveying plate 20a. The plurality of objects 2 to be processed are arranged on the conveyed part 20 with a gap G1 in the left-right direction. In a modified example, the plurality of objects 2 to be processed may be stacked vertically and arranged horizontally on one conveying plate 20a. In this case, the gap G1 is disposed between two rows of objects to be processed 2 aligned in the left-right direction.

[0034] As shown in FIG. 5, the uppermost workpiece 2 among the multiple workpieces 2 on the conveying plate 20a is disposed below the first partition wall 14. The uppermost workpiece 2 is separated from the lower end of the first partition wall 14. In the vertical direction, the distance D1 between the uppermost workpiece 2 and the lower end of the first partition wall 14 is 10 mm or more and 30 mm or less. This prevents the uppermost workpiece 2 from contacting the first partition wall 14. In addition, the space between the uppermost workpiece 2 and the first partition wall 14 is prevented from becoming too large. This prevents a gas (for example, an atmospheric gas described later) from passing through the space between the uppermost workpiece 2 and the first partition wall 14. The distance D1 may be 10 mm or more and 20 mm or less, or 10 mm or more and 15 mm or less.

[0035] As shown in FIG. 4, the transported part 20 is disposed on a mounting rail 64. The transported part 20 is disposed between two guide rails 66 adjacent to each other in the left-right direction. The guide rails 66 are disposed between the two transported parts 20 adjacent to each other in the left-right direction. The transported part 20 (two transport plates 20a) is pressed by a pusher 22 (see FIG. 1) to move forward in the internal space 54 in the furnace body 12. The transported part 20 is guided forward by the guide rails 66 and slides on the mounting rails 64. When the transported part 20 moves in the heat treatment space 58, the workpiece 2 is heated. When the transported part 20 moves in the cooling space 60, the workpiece 2 is cooled.

[0036] As shown in FIG. 1, the pusher 22 is disposed outside the furnace body 12 near the carry-in entrance 46a. The pusher 22 is configured to push the conveying plate 20a forward. The pusher 22 moves the conveyed part 20 by a distance equivalent to the length of the conveyed part 20 in the front-rear direction by pushing the conveyed part 20 once. In this embodiment, the pusher 22 simultaneously pushes three conveyed parts 20 (six conveying plates 20a) arranged in the left-right direction forward. As a result, the three conveyed parts 20 move from the carry-in entrance 46a into the internal space 54, and the multiple conveyed parts 20 in the internal space 54 are pushed forward by the movement of the three conveyed parts 20. As the pusher 22 repeatedly presses the transported part 20, the transported part 20 is transported from the carry-in opening 46a into the internal space 54, passes through the heat treatment space 58 and the cooling space 60 in that order, and is then transported from the carry-out opening 48a to the outside of the furnace body 12. Note that the configuration of the pusher 22 is well known, so a detailed description of the configuration will be omitted.

[0037] As shown in FIG. 6, the second partition 26 extends upward from the upper surface of the guide rail 66 to the first partition 14. The upper end of the second partition 26 is connected to the lower end of the first partition 14. The width of the second partition 26 in the left-right direction is approximately the same as the width of the guide rail 66 in the left-right direction. In this embodiment, four second partitions 26 are arranged in a row in the left-right direction. The rightmost second partition 26 is arranged to the right of the workpiece 2 on the rightmost conveyed portion 20. The leftmost second partition 26 is arranged to the left of the workpiece 2 on the leftmost conveyed portion 20. Each of the two second partitions 26 located in the center is arranged between the workpiece 2 on the conveyed portion 20 arranged to the right of the guide rail 66 and the workpiece 2 on the conveyed portion 20 arranged to the left of the guide rail 66.

[0038] As shown in Fig. 7, the multiple second partitions 26 are arranged side by side in the front-rear direction. The distance D2 between two adjacent second partitions 26 in the front-rear direction is equal to or greater than the length L1 of the transported portion 20 (one transport plate 20a) in the front-rear direction. The distance D2 is an integer multiple of the length L1. The distance D2 is, for example, equal to or greater than two times and equal to or less than five times the length L1. In this embodiment, the distance D2 is three times the length L1.

[0039] As shown in FIG. 8, the side surface of the second partition wall 26 is separated from the workpiece 2 on the transported portion 20 in the left-right direction. In the left-right direction, the distance D3 between the side surface of the second partition wall 26 and the workpiece 2 is 10 mm or more and 30 mm or less. This prevents the workpiece 2 from contacting the second partition wall 26. Also, the space between the workpiece 2 and the second partition wall 26 is prevented from becoming too large. This prevents gas (e.g., atmospheric gas, which will be described later) from passing through the space between the multiple workpieces 2 on the transport plate 20a and the second partition wall 26. The distance D3 may be 10 mm or more and 20 mm or less, or 10 mm or more and 15 mm or less.

[0040] As shown in FIG. 4, a plurality of air supply pipes 28 are arranged in the heat treatment space 58. The air supply pipes 28 are made of ceramics, such as mullite, alumina, and silicon carbide. A plurality of (four in this embodiment) air supply pipes 28 are arranged in a row in the left-right direction. The air supply pipes 28 are inserted into the guide rail 66. The rightmost air supply pipe 28 is arranged on the right side of the workpiece 2 on the rightmost conveyed portion 20. The leftmost air supply pipe 28 is arranged on the left side of the workpiece 2 on the leftmost conveyed portion 20. Each of the two central air supply pipes 28 is arranged between the workpiece 2 on the conveyed portion 20 arranged on the right side of the guide rail 66 and the workpiece 2 on the conveyed portion 20 arranged on the left side of the guide rail 66.

[0041] As shown in Fig. 7, the multiple air supply pipes 28 are arranged side by side in the front-rear direction. The distance D4 between two air supply pipes 28 adjacent in the front-rear direction is equal to or greater than the length L1. The distance D4 is an integer multiple of the length L1. The distance D4 is, for example, equal to or greater than two times and equal to or less than five times the length L1. In this embodiment, the distance D4 is three times the length L1. Moreover, the distance D4 is approximately the same as the distance D2.

[0042] 9, air supply pipe 28 extends upward from guide rail 66 toward upper wall 42. The upper end of air supply pipe 28 is disposed above the upper end of the uppermost workpiece 2 among the multiple workpieces 2 on conveying plate 20a. Air supply pipe 28 is separated from workpiece 2 on conveying plate 20a in the left-right direction.

[0043] The air supply pipe 28 is configured to supply the atmospheric gas to the heat treatment space 58. The atmospheric gas is, for example, air, oxygen gas, or nitrogen gas. The air supply pipe 28 has a plurality of air supply ports 28a. In this embodiment, six air supply ports 28a are arranged in a line in the vertical direction. The distance between adjacent air supply ports 28a in the vertical direction is approximately the same as the vertical width of the sagger 4. In the rightmost air supply pipe 28, six air supply ports 28a are located at the right end of the air supply pipe 28. In the leftmost air supply pipe 28, six air supply ports 28a are located at the left end of the air supply pipe 28. In the two central air supply pipes 28, six air supply ports 28a are located at the right and left ends of the air supply pipe 28. Of two air supply pipes 28 adjacent to each other in the left-right direction, the air supply port 28a of one air supply pipe 28 faces the air supply port 28a of the other air supply pipe 28 in the left-right direction.

[0044] As shown in FIG. 9, the air inlet 28a is disposed at a position opposite to the notch 5 of the sagger 4 in the left-right direction. That is, the vertical position of the air inlet 28a is substantially the same as the vertical position of the notch 5. The air inlet 28a supplies the atmosphere gas to the right and / or left toward the notch 5. As a result, the atmosphere gas passes through the notch 5 and flows into the inside of the sagger 4, and then passes through the notch 5 and flows out of the sagger 4, that is, into the gap G1. As the atmosphere gas passes through the sagger 4, the gas generated from the workpiece body 6 is discharged from the sagger 4. The flow rate of the atmosphere gas supplied from each air inlet 28a is the same. Therefore, the atmosphere gas is uniformly supplied to each of the multiple workpieces 2 stacked on the conveying plate 20a.

[0045] As shown in Fig. 4, the regulating valve 30 is disposed outside the furnace body 12. The regulating valve 30 can be opened and closed. The regulating valve 30 regulates the flow rate of the atmospheric gas supplied from the air supply port 28a to the heat treatment space 58. When the regulating valve 30 is open, the atmospheric gas is permitted to be supplied from the air supply port 28a to the heat treatment space 58. When the regulating valve 30 is closed, the atmospheric gas is prohibited from being supplied from the air supply port 28a to the heat treatment space 58.

[0046] The supply pipe 32 is connected to each of the four air supply pipes 28 arranged in the left-right direction. The supply pipe 32 extends in a straight line. In a modified example, the supply pipe 32 may extend in a zigzag shape. The supply pipe 32 supplies the atmosphere gas to the air supply pipe 28. The supply pipe 32 passes through the lower wall 44 by penetrating the lower wall 44. The atmosphere gas flows through the supply pipe 32 from the right end of the supply pipe 32 toward the center, and also flows through the supply pipe 32 from the left end of the supply pipe 32 toward the center. The atmosphere gas is heated by the lower wall 44 while flowing through the supply pipe 32. As a result, the heated atmosphere gas is supplied to the air supply pipe 28. Therefore, when the atmosphere gas is supplied to the heat treatment space 58 from the air supply port 28a of the air supply pipe 28, a decrease in the temperature of the heat treatment space 58 is suppressed.

[0047] 1, the furnace body 12 has a plurality of exhaust ports 70. The exhaust ports 70 are arranged in the upper wall 42. The exhaust ports 70 penetrate the upper wall 42 in the vertical direction. The exhaust ports 70 communicate between the internal space 54 of the furnace body 12 and the outside of the furnace body 12.

[0048] Each exhaust port 70 is disposed in each furnace space 58a. The exhaust ports 70 are arranged side by side in the front-rear direction. In the front-rear direction, the exhaust ports 70 are arranged near the first partition wall 14. The exhaust ports 70 are arranged rearward of the air supply pipe 28. As shown in FIG. 7, the distance D5 between two exhaust ports 70 adjacent to each other in the front-rear direction is equal to or longer than the length L1. The distance D5 is an integer multiple of the length L1. The distance D5 is, for example, equal to or longer than twice the length L1 and equal to or shorter than five times the length L1. In this embodiment, the distance D5 is three times the length L1. The distance D5 is approximately equal to the distance D2. In the case of the exhaust ports 70 and the air supply pipe 28 arranged in the same furnace space 58a, the distance D6 between the exhaust ports 70 and the air supply pipe 28 in the front-rear direction is longer than the length L1.

[0049] Further, the multiple exhaust ports 70 (three in this embodiment) are arranged side by side in the left-right direction. The exhaust port 70 is arranged at the center position between two adjacent guide rails 66 in the left-right direction. The exhaust port 70 is arranged at the boundary position between two adjacent transport plates 20a in the left-right direction.

[0050] As shown in FIG. 9, when the heat treatment furnace 10 is viewed rearward along the front-rear direction, the exhaust port 70 is disposed directly above the gap G1 in the left-right direction between two workpieces 2 arranged side by side in the left-right direction. When the heat treatment furnace 10 is viewed rearward along the front-rear direction, the exhaust port 70 overlaps the gap G1 in the up-down direction. The center position of the gap G1 in the left-right direction is substantially the same as the center position of the exhaust port 70 in the left-right direction. The width W3 in the left-right direction of the exhaust port 70 is equal to or larger than the width W4 in the left-right direction of the gap G1. The width W3 is equal to or larger than the width W4 and equal to or smaller than three times. This prevents the atmospheric gas that has passed through the gap G1 and the gas generated from the workpiece body 6 from stagnating between the upper wall 42 and the workpiece 2. The width W3 may be equal to or larger than the width W4 and equal to or smaller than the width W4, or may be equal to or larger than the width W4 and equal to or smaller than two times.

[0051] 10, the control device 36 is electrically connected to each of the heater 16, the pusher 22, and the regulating valve 30. The control device 36 controls the heater 16 to generate heat. The control device 36 controls the pusher 22 so that the pusher 22 presses the transported portion 20.

[0052] The control device 36 also prestores the length L1 of the conveyed part 20 (conveying plate 20a) in the front-rear direction, the width W1 of the notch 5 of the sagger 4, the front-rear position of the notch 5 in the conveyed part 20, the forward moving speed of the conveyed part 20 due to the pressure of the pusher 22, and the positions of the multiple air supply pipes 28. Based on the length L1, width W1, notch position, moving speed, and positions of the multiple air supply pipes 28, the control device 36 calculates and stores the timing at which the air supply pipe 28 overlaps with the notch 5 in the left-right direction when the conveyed part 20 is moving due to the pressure of the pusher 22. The air supply pipe 28 overlaps with the notch 5 in the left-right direction between the first time and the second time after the pusher 22 starts pressing. When the pusher 22 starts to press the conveyed portion 20, the control device 36 controls the opening and closing of the regulating valve 30 based on the timing at which the air supply pipe 28 overlaps with the notch 5 in the left-right direction.

[0053] Specifically, the control device 36 closes the adjusting valve 30 until a first time has elapsed since the pusher 22 starts to press the transported portion 20. At this time, as shown in FIG. 11, the air supply pipe 28 does not overlap the notch 5 in the left-right direction.

[0054] Next, the control device 36 opens the regulating valve 30 when a first time has elapsed since the pusher 22 started to press the transported part 20. At this time, as shown in FIG. 12, the air supply pipe 28 overlaps with the notch 5 in the left-right direction. By opening the regulating valve 30, the atmosphere gas is supplied from the air supply port 28a of the air supply pipe 28 toward the notch 5 in the right and / or left direction. As shown in FIG. 7, since the air supply pipe 28 is disposed on the rear side of the second partition wall 26, the atmosphere gas is prevented from crossing the second partition wall 26 in the forward direction and flowing into another furnace space 58a. As a result, as shown in FIG. 9, the atmosphere gas passes through the notch 5 and flows into the inside of the sagger 4. Next, the atmosphere gas passes through the notch 5 together with the gas generated from the workpiece body 6 and flows out into the gap G1. The atmosphere gas in the gap G1 flows upward (in the stacking direction of the plurality of workpieces 2) along the side surface of the workpiece 2 together with the gas generated from the workpiece body 6. Next, as shown in FIG. 13, when the atmospheric gas exceeds the upper end of the workpiece 2 located at the uppermost position, the atmospheric gas flows in the furnace space 58a along the upper wall 42 in the rear direction opposite to the moving direction (forward direction) of the transported part 20 together with the gas generated from the workpiece body 6. FIG. 13 is a cross-sectional view crossing the second partition 26 and the air supply pipe 28. Also, since the distance D1 (see FIG. 5) between the workpiece 2 and the lower end of the first partition 14 is 10 mm or more and 30 mm or less, the atmospheric gas and the gas generated from the workpiece body 6 are prevented from crossing the first partition 14 in the forward direction and flowing into the other furnace space 58a. Next, the atmospheric gas passes through the exhaust port 70 together with the gas generated from the workpiece body 6 and is discharged from the furnace space 58a to the outside of the furnace body 12. 9, when the heat treatment furnace 10 is viewed rearward along the front-rear direction, the exhaust port 70 is disposed directly above the gap G1 in the left-right direction between two workpieces 2 aligned in the left-right direction, so that the atmospheric gas smoothly flows into the exhaust port 70 together with the gas generated from the workpiece body 6. This makes it possible to prevent the atmospheric gas and the gas generated from the workpiece body 6 from accumulating in the furnace space 58a.

[0055] The control device 36 closes the adjusting valve 30 when the second time has elapsed since the pusher 22 started to press the conveyed part 20. This stops the supply of the atmospheric gas from the air supply port 28a. At this time, the air supply pipe 28 does not overlap the notch 5 in the left-right direction. By opening the adjusting valve 30 only between the first time and the second time, the amount of the atmospheric gas supplied can be reduced and the atmospheric gas can be efficiently supplied into the sagger 4, compared to a configuration in which the atmospheric gas valve is always open.

[0056] (effect) In the first embodiment described above, when the heat treatment furnace 10 is viewed rearward along the front-rear direction, the exhaust port 70 is disposed directly above the gap G1 in the left-right direction between two workpieces 2 aligned in the left-right direction. As a result, the atmospheric gas flows through the gap G1 between the two workpieces 2 aligned in the left-right direction together with the gas generated from the workpiece body 6, and then flows upward toward the exhaust port 70, and is discharged from the exhaust port 70 to the outside of the furnace body 12. As a result, it is possible to prevent the atmospheric gas and the gas generated from the workpiece body 6 from stagnation in the furnace body 12.

[0057] (Second Example) In the second embodiment, only the differences from the first embodiment will be described. As shown in FIG. 14, the multiple air intake pipes 28 are composed of multiple first air intake pipes 128 and multiple second air intake pipes 130. The configurations of the first air intake pipes 128 and the second air intake pipes 130 are the same as the configurations of the air intake pipes 28 in the first embodiment. The first air intake pipes 128 and the second air intake pipes 130 are arranged alternately in the front-rear direction. The first air intake pipes 128 and the second air intake pipes 130 are arranged alternately in the left-right direction. In the first air intake pipes 128 and the second air intake pipes 130 adjacent to each other in the left-right direction, the air intake port 28a (see FIG. 9) of the first air intake pipe 128 faces the air intake port 28a of the second air intake pipe 130 in the left-right direction.

[0058] The regulating valve 30 shown in FIG. 10 switches between a first opening and a second opening. When the regulating valve 30 is at the first opening, the atmospheric gas is supplied from the air supply port 28a (see FIG. 9) of the air supply pipe 28 at a first air supply rate. When the regulating valve 30 is at the second opening, the atmospheric gas is supplied from the air supply port 28a at a second air supply rate. The second air supply rate is different from the first air supply rate. The second air supply rate is less than the first air supply rate.

[0059] The control device 36 switches the regulating valve 30 between the first opening and the second opening. The control device 36 controls the regulating valve 30 so that the opening of the regulating valve 30 connected to the first air supply pipe 128 is different from the opening of the regulating valve 30 connected to the second air supply pipe 130. Specifically, as shown in FIG. 14, when the control device 36 (see FIG. 10) switches the regulating valve 30 (see FIG. 10) connected to the first air supply pipe 128 from the first opening to the second opening, the control device 36 (see FIG. 10) switches the regulating valve 30 (see FIG. 10) connected to the second air supply pipe 130 from the second opening to the first opening. As a result, the atmospheric gas is supplied to the heat treatment space 58 from the air supply port 28a (see FIG. 9) of the first air supply pipe 128 at the first supply amount. Also, the atmospheric gas is supplied to the heat treatment space 58 from the air supply port 28a (see FIG. 9) of the second air supply pipe 130 at the second supply amount. In addition, in FIG. 14 and FIG. 15, the flow of the atmospheric gas is indicated by arrows.

[0060] As shown in FIG. 15, when the control device 36 switches the regulating valve 30 connected to the first air supply pipe 128 from the second opening to the first opening, the control device 36 switches the regulating valve 30 connected to the second air supply pipe 130 from the first opening to the second opening. As a result, the atmospheric gas is supplied to the heat treatment space 58 from the air supply port 28a of the first air supply pipe 128 at the second supply amount. Also, the atmospheric gas is supplied to the heat treatment space 58 from the air supply port 28a of the second air supply pipe 130 at the first supply amount. The regulating valve 30 is controlled so that the opening of the regulating valve 30 connected to the first air supply pipe 128 and the opening of the regulating valve 30 connected to the second air supply pipe 130 are different, and thus the atmospheric gas in the heat treatment space 58 is agitated. As a result, the concentration of the gas components generated from the workpiece 2 in the atmospheric gas can be made uniform in the heat treatment space 58.

[0061] (Correspondence) The first air supply pipe 128 corresponds to the "one air supply pipe." The second air supply pipe 130 corresponds to the "other air supply pipe."

[0062] (Third Example) In the third embodiment, only the differences from the first embodiment will be described. As shown in FIG. 16, the heaters 16 include a plurality of heating heaters 216 and a plurality of heat retention heaters 218. In FIG. 16, only the heat treatment space 58 is shown, and the cooling space 60 is omitted. The heating heaters 216 are arranged in the space on the entrance 46a side in the heat treatment space 58. Hereinafter, the space on the entrance 46a side in the heat treatment space 58 is referred to as the heating space 258. The heating space 258 is connected to the entrance 46a. The heating space 258 is composed of a plurality of furnace spaces 58a.

[0063] The plurality of heat retention heaters 218 are arranged in front of the plurality of temperature raising heaters 216. The plurality of heat retention heaters 218 are arranged in the space on the discharge port 48a (see FIG. 1) side in the heat treatment space 58. Hereinafter, the space on the discharge port 48a side of the heat treatment space 58 is referred to as the heat retention space 260. The heat retention space 260 communicates with the temperature raising space 258. The heat retention space 260 is arranged in front of the temperature raising space 258. The heat retention space 260 is composed of a plurality of furnace spaces 58a.

[0064] The amount of heat generated by the temperature-raising heater 216 is greater than the amount of heat generated by the temperature-retention heater 218. The temperature-raising heater 216 raises the temperature of the temperature-raising space 258. The temperature-retention heater 218 maintains the temperature of the temperature-retention space 260 at a substantially constant value. The temperature of the temperature-retention space 260 is higher than the temperature of the temperature-raising space 258.

[0065] A plurality of exhaust ports 70 are disposed in the temperature raising space 258. The exhaust ports 70 are disposed in each furnace space 58a. In each furnace space 58a, the exhaust ports 70 are disposed rearward of the temperature raising heater 216.

[0066] In the third embodiment, the atmospheric gas supplied from the air supply port 28a (see FIG. 9) of the air supply pipe 28 in the heat retention space 260 flows in the direction toward the entrance 46a (rearward) in the heat retention space 260. In FIG. 16, the flow of the atmospheric gas is indicated by an arrow. Next, the atmospheric gas flows from the heat retention space 260 into the temperature rise space 258 together with the gas generated from the workpiece body 6 (see FIG. 9). The atmospheric gas heated in the heat retention space 260 flows into the temperature rise space 258, so that the temperature rise space 258 is heated. As a result, the amount of heat generated by the temperature rise heater 216 can be reduced compared to a configuration in which the atmospheric gas does not flow from the heat retention space 260 into the temperature rise space 258. The atmospheric gas that flows into the temperature rise space 258 flows toward the exhaust port 70 together with the gas generated from the workpiece body 6, and is discharged from the exhaust port 70 to the outside of the furnace body 12. This makes it possible to prevent the atmospheric gas and the gas generated from the workpiece body 6 from remaining in the temperature increasing space 258 and the heat retaining space 260 .

[0067] (Fourth Example) In the fourth embodiment, only the points different from the first embodiment will be described. As shown in FIG. 17, in the heat treatment furnace 10, the exhaust port 370 is arranged across the first partition wall 14 and the upper wall 42 of the furnace body 12. The exhaust port 370 is arranged above the workpiece 2. The exhaust port 370 extends rearward from the front surface of the first partition wall 14, then bends, and extends upward within the first partition wall 14 and the upper wall 42. The exhaust port 370 opens forward within the furnace space 58a. The exhaust port 370 communicates between the furnace space 58a and the outside of the furnace body 12.

[0068] 18, when the heat treatment furnace 10 is viewed rearward along the front-rear direction, the exhaust port 370 is disposed directly above the gap G1. The left-right center position of the gap G1 is substantially the same as the left-right center position of the exhaust port 370. The left-right width W5 of the exhaust port 370 is substantially the same as the left-right width W3 of the exhaust port 70 of the first embodiment. The width W5 is equal to or greater than the left-right width W4 of the gap G1.

[0069] The atmospheric gas flows upward through the gap G1 together with the gas generated from the workpiece body 6. As shown in Fig. 17, when the atmospheric gas passes the upper end of the workpiece 2 located at the uppermost position, the atmospheric gas flows in the furnace space 58a together with the gas generated from the workpiece body 6 in the rear direction opposite to the moving direction (forward direction) of the transfer part 20. Next, the atmospheric gas passes through the exhaust port 370 together with the gas generated from the workpiece body 6 and is exhausted from the furnace space 58a to the outside of the furnace body 12.

[0070] (Modification) In one embodiment, the control device 36 may always open the regulating valve 30 when the pusher 22 is pressing against the conveyed portion 20 .

[0071] Although specific examples of the technology disclosed in this specification have been described in detail above, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and variations of the specific examples exemplified above. Furthermore, the technical elements described in this specification or drawings exhibit technical utility alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Furthermore, the technology exemplified in this specification or drawings achieves multiple objectives simultaneously, and achieving one of the objectives itself has technical utility. [Explanation of symbols]

[0072] 2: Workpiece 4: Box 4a: Side wall 5: Cutout 6: Main body of the object to be treated 10: Heat treatment furnace 12:Furnace body 14: 1st bulkhead 16: Heater 18: Guide section 20: Carried part 20a: conveyor plate 22: Pusher 26:Second bulkhead 28: Air supply pipe 28a: Air supply port 30: Regulating valve 32: Supply pipe 36: Control device 42: Upper wall 44: Lower wall 46:Furnace inlet wall 46a: Loading entrance 48:Furnace outlet wall 48a: Exit 50: Right side wall 52: Left side wall 54: Interior space 58: Heat treatment space 58a: Furnace space 60: Cooling space 64: Mounting rail 66: Guide rail 68: Spacer 70: Exhaust port 128: First air supply pipe 130: Second air supply pipe 216: Heating heater 218: Heater 258:Heated space 260:Heat insulation space 370: Exhaust port D1: Distance D2 :Distance D3: Distance D4: Distance D5 :Distance D6 :Distance G1: Gap W1:Width W2:Width W3:Width W4:Width W5:Width

Claims

1. A heat treatment furnace, A furnace body including an entrance, an exit, and a heat treatment space for heat-treating a plurality of objects to be treated; A plurality of conveying sections are arranged in a line in a forward direction, on which the plurality of objects to be processed can be placed in a state in which the objects to be processed are stacked in a vertical direction and arranged with gaps in a left-right direction perpendicular to the vertical direction; a pusher that presses the transported portion in the forward direction from the inlet to the outlet of the furnace body; a plurality of air supply pipes arranged in the left-right direction, the air supply pipes having an air supply port for supplying an atmospheric gas into the heat treatment space, the transported portion is disposed between the air supply pipes adjacent to each other in the left-right direction, the air supply port of the air supply pipe is arranged to supply the atmospheric gas to the objects to be treated stacked in the vertical direction, the heat treatment furnace has a plurality of exhaust ports for discharging the atmospheric gas in the heat treatment space to the outside of the furnace body, A heat treatment furnace, wherein the exhaust port is disposed directly above a gap between the plurality of workpieces arranged in the left-right direction on the transported portion when the furnace body is viewed along the front direction.

2. 2 . The heat treatment furnace according to claim 1 , wherein the width of the exhaust port in the left-right direction is equal to or greater than 1 time and equal to or less than 3 times the width of the gap in the left-right direction of the plurality of workpieces arranged in the left-right direction.

3. The plurality of air supply pipes are arranged side by side in the forward direction, The heat treatment furnace according to claim 1 , wherein a distance between adjacent ones of the air supply pipes in the forward direction is an integer multiple of a length of the transported portion in the forward direction.

4. a regulating valve that allows the atmospheric gas to be supplied from the air supply port when the regulating valve is open and prohibits the atmospheric gas from being supplied from the air supply port when the regulating valve is closed; and A control device that controls the opening and closing of the regulating valve, The object to be treated is located at an upper portion of the object to be treated and has a notch that communicates between the inside and the outside of the object to be treated, The heat treatment furnace according to claim 1 , wherein the control device opens the regulating valve when the air supply pipe overlaps with the notch in the left-right direction.

5. a plurality of regulating valves, the regulating valves switching an amount of the atmospheric gas supplied from the air supply port between a first air supply amount and a second air supply amount different from the first air supply amount; A control device for controlling the plurality of regulating valves, In the air supply pipes adjacent to each other in the left-right direction, the air supply port of one of the air supply pipes faces the air supply port of the other of the air supply pipes, 2. The heat treatment furnace of claim 1, wherein the control device switches the amount of air supplied from the air supply port of the one of the air supply pipes to the second supply air amount when the control device switches the amount of air supplied from the air supply port of the other of the air supply pipes to the second supply air amount.

6. the heat treatment space has a plurality of furnace spaces defined by a plurality of first partition walls arranged side by side in the forward direction and above the workpiece, The heat treatment furnace according to claim 1 , wherein each of the plurality of exhaust ports is disposed in each of the plurality of furnace spaces.

7. a plurality of guide rails, the transported portion being disposed between adjacent guide rails in the left-right direction, the guide rails extending in the forward direction and guiding the transported portion in the forward direction; The heat treatment furnace of claim 6 , further comprising: a plurality of second partitions, said second partitions extending from said guide rail to said first partition.

8. The heat treatment furnace according to claim 7 , wherein a distance between the second partition wall and the workpiece in the left-right direction is not less than 10 mm and not more than 30 mm.

9. 7. The heat treatment furnace according to claim 6, wherein in each of the plurality of furnace spaces, a distance between the exhaust port and the air supply pipe in the front direction is longer than a length of the transported part in the front direction.

10. 7. The heat treatment furnace according to claim 6, wherein a distance between the first partition and the workpiece is 10 mm or more and 30 mm or less.

11. The heating heater and the heat retention heater are further provided in the heat treatment space, The heat treatment space has a plurality of furnace spaces arranged side by side in the forward direction, The plurality of furnace spaces include a heating space in which the heating heater is disposed and which communicates with the loading port; The heater is disposed in a heat retention space, the heat retention space being in communication with the temperature rise space. The heat treatment furnace according to claim 1 , wherein the exhaust port is disposed in the temperature increasing space.

12. 2. The heat treatment furnace according to claim 1, wherein the air supply pipe is made of ceramics.

13. a supply pipe connected to each of the plurality of air supply pipes for supplying the atmospheric gas to the plurality of air supply pipes, The heat treatment furnace according to claim 1 , wherein the supply pipe passes through a wall of the furnace body.

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