TWI839439B - Heat treatment furnace - Google Patents

Abstract

The present invention provides a technology for properly maintaining the furnace atmosphere temperature of each space in a heat treatment furnace. The heat treatment furnace performs heat treatment on the treated object. The heat treatment furnace has a furnace body and a conveying device, the furnace body has: a first space for heat treating the treated object at a first temperature, a second space for heat treating the treated object at a second temperature different from the first temperature, and a partition wall separating the first space and the second space, the conveying device transports the treated object from one end of the first space to the other end of the second space. The partition wall has a connecting channel and a third space, the connecting channel connects the first space with the second space, the third space is arranged in the partition wall, separated from the first space and the second space, and connected to the connecting channel.

Description

Heat treatment furnace

The technology disclosed in this specification relates to a heat treatment furnace for heat treating a treated object.

Sometimes a heat treatment furnace (e.g., a roller kiln) is used to heat treat the object to be treated. In such a heat treatment furnace, the internal space of the furnace body is divided into multiple spaces, and the object to be treated is transported to these spaces in sequence. The various steps required for heat treatment of the object to be treated (e.g., debonding step, firing step, etc.) are implemented by adjusting the furnace atmosphere temperature of each space inside the furnace body. Multiple spaces are adjusted to different furnace atmosphere temperatures in accordance with each step. For example, Patent Document 1 discloses an example of a heat treatment furnace.

[Prior Art Literature] [Patent Literature]

Patent document 1: Japanese Patent Publication No. 2016-156612

In order to perform heat treatment on the object to be processed with the desired temperature distribution, it is necessary to control the furnace atmosphere temperature of each space inside the furnace body separately and appropriately maintain the furnace atmosphere temperature of each space. However, in each space, near the area adjacent to other spaces with different furnace atmosphere temperatures, due to the influence of heat conduction from one adjacent space to another space, it is sometimes impossible to appropriately maintain the furnace atmosphere temperature of the space at the desired temperature. Therefore, the following problem arises: near the boundary of two adjacent spaces with different furnace atmosphere temperatures, it is difficult to control the object to be processed to the desired temperature distribution. This specification discloses a technology for appropriately maintaining the furnace atmosphere temperature of each space in a heat treatment furnace.

The heat treatment furnace disclosed in this specification performs heat treatment on the treated object. The heat treatment furnace has a furnace body and a conveying device. The furnace body has: a first space for heat treating the treated object at a first temperature, a second space for heat treating the treated object at a second temperature different from the first temperature, and a partition wall separating the first space and the second space. The conveying device transports the treated object from one end of the first space to the other end of the second space. The partition wall has a connecting channel and a third space. The connecting channel connects the first space with the second space. The third space is arranged in the partition wall, separated from the first space and the second space by the partition wall, and connected to the connecting channel.

In the above-mentioned heat treatment furnace, a third space is provided in the partition wall separating the first space and the second space. Thus, the influence of heat transfer from one of the first space and the second space to the other space can be suppressed. Therefore, the furnace atmosphere temperature in the first space and the furnace atmosphere temperature in the second space can be appropriately maintained respectively.

10: Heat treatment furnace

12: Objects to be processed

20: Furnace body

22: Top wall

24: Bottom wall

26a~26d: Side wall

28a,28b: Opening

30a,30b: next door

32a,32b: The first next door

34a,34b: The second room next door

36: Connecting channel

38: The Third Space

40: First Space

42: Second Space

44a~44d: Heater

46a~46c: air supply channel

48a~48c: Exhaust channel

52:Conveyor roller

54: First drive device

56: Second drive device

58: Third drive device

60: Control device

62a,62b:Sensor

L1~L3: Size

FIG1 shows a simplified structure of a heat treatment furnace of an embodiment, and is a longitudinal cross-sectional view of the heat treatment furnace cut along a plane parallel to the conveying direction of the treated object.

Figure 2 is a cross-sectional view taken along line II-II of Figure 1.

Figure 3 is used to illustrate the dimensions of the partition wall in the transport direction.

[Preferred form of implementing the invention]

The main features of the embodiments described below are listed in advance. In addition, the technical elements described below are independent technical elements, which can be used alone or in various combinations to exert technical usefulness, and are not limited to the combination described in the application.

(Feature 1) The heat treatment furnace disclosed in this specification may also have: an exhaust flow channel, which is arranged in the furnace body, one end of which is connected to the third space, and the other end is connected to the outside of the furnace body, and the gas in the third space is discharged to the outside of the furnace body. According to such a structure, the exhaust flow channel is used to discharge the gas in the first space and the gas in the second space that flow into the third space through the connecting channel to the outside of the furnace body. In this way, the gas can be suppressed from moving between the first space and the second space through the connecting channel.

(Feature 2) The heat treatment furnace disclosed in this specification may also have: a gas supply channel, which is provided in the furnace body, one end of which is connected to the third space, and the other end is connected to the outside of the furnace body, and gas is supplied from the outside of the furnace body to the third space. According to such a structure, the temperature in the third space can be adjusted by using the gas supplied from the gas supply channel. Therefore, the temperature of the third space can be adjusted to a temperature appropriate for the furnace atmosphere temperature of the first space and the furnace atmosphere temperature of the second space, so as to suppress the movement of gas between the first space and the second space through the communication channel.

(Feature 3) In the heat treatment furnace disclosed in this specification, the partition wall may also include a first partition wall separating the first space and the third space, and a second partition wall separating the second space and the third space. The dimension of the third space in the transport direction may be smaller than the dimension of the first partition wall in the transport direction when the first temperature is higher than the second temperature, and smaller than the dimension of the second partition wall in the transport direction when the second temperature is higher than the first temperature. According to such a structure, the dimensions of the first partition wall, the second partition wall and the third space in the transport direction can be appropriately adjusted, and the first space and the second space can be thermally isolated while the dimension of the third space in the transport direction that is not intended to heat the treated object can be reduced. In this way, the dimension of the partition wall in the transport direction as a whole can be reduced, and the time for transporting the treated object in the connecting channel where the heat treatment step is not performed can be shortened.

(Feature 4) In the heat treatment furnace disclosed in this specification, a first heater and a second heater are arranged in the furnace body. The first heater is arranged in the first space and can adjust the first space to the first temperature. The second heater is arranged in the second space and can adjust the second space to the second temperature. On the other hand, no heater is arranged in the third space. Since the partition wall thermally isolates the first space from the second space, it is not necessary to heat the processed object in the third space arranged in the partition wall, and it is not necessary to arrange a heater in the third space. In addition, since no heater is arranged in the third space, the size of the third space in the conveying direction can be reduced, and the time for conveying the processed object in the connecting channel where the heat treatment step is not performed can be shortened.

[Implementation example]

The heat treatment furnace 10 according to the embodiment is described below. As shown in FIG1 , the heat treatment furnace 10 includes a furnace body 20 and a conveying device (52, 54, 56, 58) for conveying a processed object 12. The heat treatment furnace 10 heat treats the processed object 12 while the processed object 12 is conveyed into the furnace body 20 by the conveying device.

As the object to be processed 12, for example, a stack of ceramic dielectrics (substrates) and electrodes, a positive electrode material or a negative electrode material of a lithium ion battery, etc. can be cited. When the ceramic stack is heat-treated using the heat treatment furnace 10, they can be placed on a flat plate-like receiving plate and transported in the furnace. In addition, when the positive electrode material or the negative electrode material of a lithium ion battery is heat-treated using the heat treatment furnace 10, they can be accommodated in a box-shaped cask and transported in the furnace. In the heat treatment furnace 10 of this embodiment, a plurality of receiving plates and casks can be placed and transported on a transport roller 52 (described later) in a state of being arranged in a transport direction. Hereinafter, in this embodiment, the material to be heat treated, the burner plate on which the material to be heat treated is placed, and the box for storing the material are collectively referred to as "the material to be treated 12".

As shown in Figures 1 and 2, the furnace body 20 is surrounded by a top wall 22, a bottom wall 24, and side walls 26a to 26d, and has partition walls (30a, 30b) inside. The furnace body 20 is roughly rectangular, and the top wall 22 is arranged parallel to the bottom wall 24 (i.e., parallel to the XY plane). As shown in Figure 1, the side wall 26a is arranged at the entrance end of the conveying path and is arranged perpendicular to the conveying direction (i.e., parallel to the YZ plane). The side wall 26b is arranged at the exit end of the conveying path and is arranged parallel to the side wall 26a (i.e., parallel to the YZ plane). As shown in Figure 2, the side walls 26c and 26d are arranged parallel to the conveying direction and perpendicular to the top wall 22 and the bottom wall 24 (i.e., parallel to the XZ plane).

As shown in FIG1 , the internal space of the furnace body 20 is divided into a first space 40 and a second space 42 by partition walls (30a, 30b). Specifically, the partition wall 30a is fixed to the top wall 22 at a position approximately in the middle between the side walls 26a, 26b, and extends vertically downward from the top wall 22. The partition wall 30b is fixed to the bottom wall 24 at a position corresponding to the partition wall 30a, and extends vertically upward from the bottom wall 24. The interior of the furnace body 20 is divided into the first space 40 and the second space 42 with the partition walls (30a, 30b) as a boundary. The partition walls 30a and 30b are separated in the up-down direction (Z direction), and a communication passage 36 is provided in the space between the separations. An opening 28a is formed in the side wall 26a of the furnace body 20, and an opening 28b is formed in the side wall 26b. The object 12 to be processed is transported from the opening 28a to the heat treatment furnace 10 by the transport device, and is transported from the opening 28b to the outside of the heat treatment furnace 10 through the connecting passage 36. That is, the opening 28a is used as the transport inlet, and the opening 28b is used as the transport outlet.

The first space 40 is surrounded by the top wall 22, the bottom wall 24, the side walls 26a, 26c, 26d and the partition walls (30a, 30b). The first space 40 is separated from the second space 42 by the partition walls (30a, 30b) in the furnace body 20, thereby maintaining a furnace atmosphere temperature different from that of the second space 42. The first space 40 is connected to the outside of the heat treatment furnace 10 by the opening 28a provided in the side wall 26a, and is connected to the second space 42 by the communication channel 36 between the partition walls 30a and 30b. A plurality of conveying rollers 52 and a plurality of heaters 44a, 44b are arranged in the first space 40. The heaters 44a are arranged at equal intervals in the conveying direction above the conveying roller 52, and the heaters 44b are arranged at equal intervals in the conveying direction below the conveying roller 52. The first space 40 is heated by making the heaters 44a and 44b generate heat.

The second space 42 is surrounded by the top wall 22, the bottom wall 24, the side walls 26b, 26c, 26d and the partition walls (30a, 30b). The second space 42 is separated from the first space 40 by the partition walls (30a, 30b) in the furnace body 20, thereby maintaining a furnace atmosphere temperature different from that of the first space 40. The second space 42 is connected to the outside of the heat treatment furnace 10 by the opening 28b provided on the side wall 26b, and is connected to the first space 40 by the connecting passage 36 between the partition walls 30a and 30b. A plurality of conveying rollers 52 and a plurality of heaters 44c, 44d are arranged in the second space 42. Heaters 44c are arranged at equal intervals in the conveying direction above the conveying roller 52, and heaters 44d are arranged at equal intervals in the conveying direction below the conveying roller 52. Heat is generated by the heaters 44c and 44d to heat the second space 42. The second space 42 is set to a different furnace atmosphere temperature from the first space 40. In this embodiment, the furnace atmosphere temperature of the second space 42 is higher than the furnace atmosphere temperature of the first space 40.

The furnace body 20 is provided with a plurality of gas supply channels 46a to 46c for supplying gas into the furnace body 20 and a plurality of gas exhaust channels 48a to 48c for exhausting gas from the furnace body 20. Specifically, the gas supply channel 46a is provided on the bottom wall 24 and is disposed between the side wall 26a and the partition wall 30b and in the vicinity of the partition wall 30b. That is, the gas supply channel 46a is provided on the downstream side of the conveying direction in the first space 40. The gas supply channel 46a is connected to the first space 40 and supplies the furnace atmosphere gas from the outside of the furnace body 20 into the first space 40. The gas atmosphere in the first space 40 is controlled by supplying the furnace atmosphere gas from the gas supply channel 46a to the first space 40. The air supply channel 46b is provided on the bottom wall 24 and is arranged between the partition wall 30b and the side wall 26b and in the vicinity of the side wall 26b. That is, the air supply channel 46b is provided on the downstream side of the conveying direction in the second space 42. The air supply channel 46b is connected to the second space 42 and supplies the furnace atmosphere gas from the outside of the furnace body 20 to the second space 42. The gas furnace atmosphere in the second space 42 is controlled by supplying the furnace atmosphere gas from the air supply channel 46b to the second space 42. The air supply channel 46c is provided on the bottom wall 24 and is arranged between the first partition wall 32b and the second partition wall 34b (described later) of the partition wall 30b. The air supply channel 46c is connected to the third space 38 (described later) and supplies gas to the third space 38. Gas is supplied to the gas supply passages 46a to 46c from a gas supply source (not shown) disposed outside the furnace body 20. The flow rate of gas supplied to each of the gas supply passages 46a to 46c is controlled by the control device 60.

The exhaust flow channel 48a is provided on the top wall 22 and is disposed between the side wall 26a and the partition wall 30a and in the vicinity of the side wall 26a. That is, the exhaust flow channel 48a is provided on the upstream side of the conveying direction in the first space 40. The exhaust flow channel 48a is connected to the first space 40 and discharges the furnace atmosphere gas in the first space 40 to the outside of the furnace body 20. The exhaust flow channel 48b is provided on the top wall 22 and is disposed between the partition wall 30a and the side wall 26b and in the vicinity of the partition wall 30a. That is, the exhaust flow channel 48b is provided on the upstream side of the conveying direction in the second space 42. The exhaust flow channel 48b is connected to the second space 42 and discharges the furnace atmosphere gas in the second space 42 to the outside of the furnace body 20. The exhaust flow channel 48c is provided on the top wall 22, and is disposed between the first partition wall 32a and the second partition wall 34a (described later) of the partition wall 30a. The exhaust flow channel 48c is connected to the third space 38 (described later), and the gas in the third space 38 is discharged to the outside of the furnace body 20. The flow rate of the gas discharged from the exhaust flow channels 48a~48c is controlled by the control device 60 to correspond to the flow rate of the gas supplied by the supply flow channels 46a~46c.

In addition, in this embodiment, exhaust channels 48a and 48b are provided on the upstream side of the conveying direction in each space 40 and 42, and air supply channels 46a and 46b are provided on the downstream side of the conveying direction in each space 40 and 42. In addition, air supply channels 46a to 46c are provided on the bottom wall 24 surrounding each space 40, 42 and 38, and exhaust channels 48a to 48c are provided on the top wall 22 surrounding each space 40, 42 and 38. However, the configuration position and configuration quantity of the air supply channel and the exhaust channel are not limited to the configuration of this embodiment, and can be appropriately changed according to the heat treatment conditions, etc.

Next, the structure of the partition walls (30a, 30b) is described. The partition wall 30a includes a first partition wall 32a disposed at a position adjacent to the first space 40, and a second partition wall 34a disposed at a position adjacent to the second space 42. The first partition wall 32a and the second partition wall 34a are separated in the conveying direction, and a part of the third space 38 is provided between the first partition wall 32a and the second partition wall 34a. The partition wall 30b includes a first partition wall 32b disposed at a position adjacent to the first space 40, and a second partition wall 34b disposed at a position adjacent to the second space 42. The first partition wall 32b is disposed at a position corresponding to the first partition wall 32a, and the second partition wall 34b is disposed at a position corresponding to the second partition wall 34a. The first partition wall 32b and the second partition wall 34b are separated in the conveying direction, and another part of the third space 38 is provided between the first partition wall 32b and the second partition wall 34b. That is, the third space 38 is surrounded by the top wall 22, the bottom wall 24, the first partition wall 32a and the second partition wall 34a of the partition wall 30a, and the first partition wall 32b and the second partition wall 34b of the partition wall 30b, and is connected to the connecting passage 36; and there is no partition wall in the third space.

As shown in FIG3 , the dimension L1 of the third space 38 in the transport direction (i.e., the X direction) is smaller than the dimension L2 of the second partition walls 34a, 34b in the transport direction (i.e., the X direction). That is, in order to suppress the influence of heat conduction from the second space 42 side to the first space 40 side, it is necessary to extend the dimension of the second partition walls 34a, 34b in the transport direction to a certain extent. Therefore, by making the dimension L1 of the third space 38 smaller than the dimension of the second partition walls 34a, 34b in the transport direction, the dimension of the partition walls (30a, 30b) that do not contribute to the heat treatment of the object 12 is suppressed from becoming longer in the transport direction. Similarly, in order to suppress the influence of heat conduction from the first space 40 side to the second space 42 side, it is necessary to extend the dimension of the first partition walls 32a, 32b in the transport direction to a certain extent. By making the dimension L1 of the third space 38 in the transport direction smaller than the dimension L3 of the first partition walls 32a and 32b in the transport direction (i.e., the X direction), the dimension of the partition walls (30a and 30b) in the transport direction is suppressed from becoming longer. In addition, as shown in FIG1 , in the third space 38, unlike the first space 40 and the second space 42, no heater is configured.

For example, when the third space 38 is not provided in the partition wall (30a, 30b), if the atmosphere temperature of the first space 40 is different from the atmosphere temperature of the second space 42, the atmosphere gas easily moves from the space with a high atmosphere temperature to the space with a low atmosphere temperature. For example, when the atmosphere temperature of the second space 42 is set higher than the atmosphere temperature of the first space 40 as in the present embodiment, the atmosphere gas in the second space 42 easily flows into the first space 40 through the communication passage 36. In the heat treatment furnace 10 of the present embodiment, the third space 38 separated from the first space 40 and the second space 42 and connected to the communication passage 36 is provided in the partition wall (30a, 30b). Therefore, even if the furnace atmosphere gas in the second space 42 having a higher furnace atmosphere temperature than the first space 40 moves from the second space 42 to the third space 38 through the connecting passage 36, it is difficult for the furnace atmosphere gas moved to the third space 38 to further move through the connecting passage 36 to the first space 40. Therefore, the furnace atmosphere gas in the second space 42 can be suppressed from flowing into the first space 40.

In addition, since no heater is provided in the third space 38 to heat the space, the temperature in the third space 38 is unlikely to be higher than the temperature in the heated first space 40 and the temperature in the second space 42. Therefore, even if the furnace atmosphere gas in the first space 40 moves to the third space 38, it is unlikely that the furnace atmosphere gas moved to the third space 38 moves to the second space 42 having a higher temperature than the third space 38. Similarly, even if the furnace atmosphere gas in the second space 42 moves to the third space 38, it is unlikely that the furnace atmosphere gas moved to the third space 38 moves to the first space 40 having a higher temperature than the third space 38. Therefore, the furnace atmosphere gas in the second space 42 can be suppressed from flowing into the first space 40, and the furnace atmosphere gas in the first space 40 can be suppressed from flowing into the second space 42.

In addition, as mentioned above, the third space 38 is connected to the air supply channel 46c and the exhaust channel 48c. The temperature of the gas supplied by the air supply channel 46c is lower than the furnace atmosphere gas heated in the first space 40 and the furnace atmosphere gas heated in the second space 42. Therefore, the temperature in the third space 38 can be adjusted to be lower than the first space 40 and the second space 42 by using the gas supplied from the air supply channel 46c. As a result, the gas in the third space 38 is difficult to move to the first space 40 and the second space 42, and the movement of the gas between the first space 40 and the second space 42 can be suppressed. In addition, the exhaust channel 48c is provided to exhaust the gas in the third space 38. Therefore, even if the furnace atmosphere gas in the first space 40 moves into the third space 38, the furnace atmosphere gas moved into the third space 38 will be discharged from the third space 38 to the outside of the furnace body 20 through the exhaust flow channel 48c, and it is difficult to move from the third space 38 to the second space 42. Similarly, even if the furnace atmosphere gas in the second space 42 moves into the third space 38, the furnace atmosphere gas moved into the third space 38 will be discharged from the third space 38 to the outside of the furnace body 20 through the exhaust flow channel 48c, and it is difficult to move from the third space 38 to the first space 40. Thus, the movement of gas between the first space 40 and the second space 42 can be suppressed.

The conveying device has a plurality of conveying rollers 52, a first driving device 54, a second driving device 56, a third driving device 58 and a control device 60. The conveying device conveys the processed object 12 from one end of the opening 28a side of the first space 40 to the other end of the opening 28b side of the second space 42 through the connecting channel 36. The processed object 12 is conveyed by the conveying roller 52.

The conveyor roller 52 is cylindrical and is disposed in the first space 40, the connecting channel 36 and the second space 42, with its axis extending in a direction perpendicular to the conveying direction (i.e., in the Y direction). The plurality of conveyor rollers 52 all have the same diameter and are arranged at equal intervals in the conveying direction at a constant pitch. The conveyor roller 52 is supported to rotate around its axis and rotates by the driving force of the transmission drive device.

The first driving device 54 is a driving device (e.g., a motor) that drives the conveying roller 52 disposed in the first space 40. The first driving device 54 is connected to the conveying roller 52 disposed in the first space 40 via a power transmission mechanism. When the driving force of the first driving device 54 is transmitted to the conveying roller 52 in the first space 40 via the power transmission mechanism, the conveying roller 52 in the first space 40 rotates. Similarly, the second driving device 56 is a driving device (e.g., a motor) that drives the conveying roller 52 disposed in the second space 42. The second driving device 56 is connected to the conveying roller 52 disposed in the second space 42 via a power transmission mechanism. When the driving force of the second driving device 56 is transmitted to the conveying roller 52 in the second space 42 via the power transmission mechanism, the conveying roller 52 in the second space 42 rotates. As the power transmission mechanism, a known power transmission mechanism can be used, such as a mechanism composed of a sprocket and a chain. The first driving device 54 and the second driving device 56 drive the corresponding conveying roller 52 so that the conveying roller 52 in the first space 40 and the conveying roller 52 in the second space 42 rotate at approximately the same speed. The first driving device 54 and the second driving device 56 are respectively controlled by the control device 60.

The third driving device 58 is a driving device (e.g., a motor) that drives the conveying roller 52 disposed in the communication channel 36, the conveying roller 52 disposed on the side of the communication channel 36 in the first space 40, and the conveying roller 52 disposed on the side of the communication channel 36 in the second space 42. The third driving device 58 is connected to the conveying roller 52 disposed in the communication channel 36, a part of the first space 40, and a part of the second space 42 via a power transmission mechanism. When the driving force of the third driving device 58 is transmitted to the conveying roller 52 via the power transmission mechanism, the conveying roller 52 rotates. As the power transmission mechanism, a known power transmission mechanism, for example, a mechanism composed of a sprocket and a chain can be used. The third drive device 58 is a structure that can change the rotation speed of the conveyor roller 52 by adjusting the output. By adjusting the output of the third drive device 58, the conveyor roller 52 connected to the third drive device 58 rotates at a speed substantially the same as the conveyor roller 52 connected to the first drive device 54 or the second drive device 56 (hereinafter also referred to as low-speed rotation), or rotates at a higher speed than the conveyor roller 52 connected to the first drive device 54 or the second drive device 56 (hereinafter also referred to as high-speed rotation). The third drive device 58 is controlled by the control device 60 respectively.

In this embodiment, the conveying roller 52 in the first space 40 is connected to the first driving device 54, and the conveying roller 52 in the second space 42 is connected to the second driving device 56, but the structure is not limited to this. For example, the conveying roller 52 in the first space 40 and the conveying roller 52 in the second space 42 can also be connected to one driving device. In addition, the third driving device 58 has a structure that can adjust the output, but it is not limited to this structure. It can also be configured so that the conveying roller 52 arranged in the communication channel 36, a part of the first space 40, and a part of the second space 42 can rotate at a low speed or a high speed without switching the output of the third driving device 58. For example, the conveying device may also include a fourth drive device that drives the conveying roller 52 in a manner that causes the conveying roller 52 to rotate at a higher speed than the first drive device 54 and the second drive device 56. In this case, the conveying roller 52 disposed in the communication channel 36 can be switched between the drive device that causes the conveying roller 52 to rotate at a low speed (i.e., the first drive device 54 or the second drive device 56) and the drive device that causes the conveying roller 52 to rotate at a high speed (i.e., the fourth drive device) by using a clutch mechanism.

Next, the operation of the heat treatment furnace 10 when the object 12 is heat treated is described. In order to heat treat the object 12, first, the heaters 44a~44d are operated to make the furnace atmosphere temperature of the first space 40 and the second space 42 become the set temperature. Then, the object 12 is placed on the conveying roller 52. Then, the first drive device 54, the second drive device 56, and the third drive device 58 are operated to convey the object 12 from the opening 28a of the heat treatment furnace 10 through the first space 40, the communication channel 36, and the second space 42 to the opening 28b of the heat treatment furnace 10. Thus, the object 12 is heat treated. In addition, as shown in FIG. 2 , in the embodiment, one object 12 is placed in the axial direction (i.e., Y direction) of the conveying roller 52 and conveyed in the heat treatment furnace 10, but the structure is not limited to this. For example, the heat treatment furnace may also be a structure in which a plurality of objects 12 are arranged in the axial direction of the conveying roller 52 to convey the object 12.

The transportation of the processed object 12 is further described in detail. First, after the processed object 12 is transported from the opening 28a, it is transported in the first space 40. In the first space 40, the first drive device 54 is operated to rotate the transport roller 52 to transport the processed object 12. At this time, the third drive device 58 is driven with an output substantially the same as that of the first drive device 54, and the transport roller 52 connected to the third drive device 58 rotates at substantially the same speed as that of the transport roller 52 connected to the first drive device 54. Therefore, the processed object 12 is transported at substantially the same speed from the time when it is transported from the opening 28a to the first space 40 to the time when it is transported out of the first space 40. While the object 12 is being transported in the first space 40, it is heat treated at the furnace atmosphere temperature in the first space 40.

When the object 12 is transported to the downstream side of the first space 40, the third drive device 58 drives the output of the transport roller 52 to rotate at high speed. The sensor 62a disposed on the first space 40 side of the first partition wall 32a of the partition wall 30a detects the object 12, thereby changing the output of the third drive device 58. For example, the sensor 62a and the sensor 62b described later can use optical sensors, and the sensors 62a and 62b can detect whether the object 12 blocks the light path. When the sensor 62a detects the front end of the object 12, the control device 60 increases the output of the third drive device 58. In this way, the object 12 is transported from the first space 40 to the communication channel 36 at high speed.

As mentioned above, the partition walls 30a and 30b are provided to separate the furnace atmosphere temperature of the first space 40 from the furnace atmosphere temperature of the second space 42, and the connecting passage 36 formed between the partition walls 30a and 30b is provided to transport the processed object 12 from the first space 40 to the second space 42. Therefore, the processed object 12 is not subjected to heat treatment during the transportation in the connecting passage 36. The processed object 12 is transported at a high speed in the connecting passage 36, and thus the processed object 12 can be transported in the connecting passage 36 that does not contribute to the heat treatment in a short time. In addition, when the temperature of the heat treatment of the processed object 12 is changed, the temperature difference before and after the temperature change is preferably set to a temperature corresponding to the processed object 12. By transporting the processed object 12 at high speed in the connecting channel 36, the processed object 12 can be rapidly heated from the furnace atmosphere temperature of the first space 40 to the furnace atmosphere temperature of the second space 42.

In addition, as mentioned above, no heater is configured in the third space 38. Therefore, the dimension of the third space 38 in the transport direction does not need to be set to a size that can accommodate the heater, and the dimension can be reduced. In addition, the dimension of the third space 38 in the transport direction is smaller than the dimension of the first partition walls 32a, 32b and the second partition walls 34a, 34b in the transport direction. By setting such a dimension, the dimension (thickness) of the first partition walls 32a, 32b and the second partition walls 34a, 34b in the transport direction can be ensured, and the dimension of the partition walls 30a, 30b as a whole in the transport direction (that is, the dimension of the communication channel 36 in the transport direction) can be reduced. In this embodiment, the furnace atmosphere temperature of the second space 42 is set to be higher than the furnace atmosphere temperature of the first space 40, so it is particularly necessary to fully ensure the thickness of the second partition walls 34a, 34b in the transport direction. By making the dimension L2 of the second partition walls 34a and 34b arranged on the second space 42 side larger than the dimension L1 of the third space 38 in the conveying direction, the thickness of the second partition walls 34a and 34b in the conveying direction can be fully ensured, and the dimension of the partition walls 30a and 30b in the conveying direction can be reduced. In this way, the dimension of the connecting passage 36 in the conveying direction can be reduced, and the object 12 to be processed can be transported in the connecting passage 36 that does not contribute to the heat treatment in a short time.

When the object 12 is transported in the communication channel 36, the output of the third drive device 58 is switched to the output substantially the same as that of the second drive device 56. In this way, the conveying roller 52 connected to the third drive device 58 rotates at substantially the same speed as that of the conveying roller 52 connected to the second drive device 56. The sensor 62b disposed on the second space 42 side of the second partition wall 34a of the partition wall 30a detects the object 12, thereby changing the output of the third drive device 58. Specifically, when the sensor 62b detects the rear end of the object 12, the control device 60 reduces the output of the third drive device 58. In this way, the object 12 is transported at a low speed in the second space 42. While the object 12 is being transported in the second space 42, it is heat treated at the furnace atmosphere temperature in the second space 42. The object 12 is transported in the second space 42 and is transported out of the heat treatment furnace 10 from the opening 28b.

The above detailed descriptions of the specific examples of the technology disclosed in this specification are only examples and do not limit the scope of the patent application. The technology described in the scope of the patent application includes various modifications and changes to the specific examples illustrated above. In addition, the technical elements described in this specification or the attached drawings are technically useful alone or in various combinations, and are not limited to the combinations described in the technical solution at the time of application.

10: Heat treatment furnace

12: Objects to be processed

20: Furnace body

22: Top wall

24: Bottom wall

26a~26d: Side wall

28a,28b: Opening

30a,30b: next door

32a,32b: The first next door

34a,34b: The second room next door

36: Connecting channel

38: The Third Space

40: First Space

42: Second Space

44a~44d: Heater

46a~46c: air supply channel

48a~48c: Exhaust channel

52:Conveyor roller

54: First drive device

56: Second drive device

58: Third drive device

60: Control device

62a,62b:Sensor

Claims (4)

A heat treatment furnace is used to perform heat treatment on a treated object. The heat treatment furnace has a furnace body and a conveying device. The furnace body has: a first space, which performs heat treatment on the treated object at a first temperature; a second space, which performs heat treatment on the treated object at a second temperature different from the first temperature; and a partition wall, which separates the first space from the second space. The conveying device conveys the treated object from one end of the first space to the other end of the second space. The partition wall has: a communication channel, which connects the first space with the second space; and a third space, which is arranged in the partition wall, separated from the first space and the second space, and connected to the communication channel. The furnace is further provided with: an exhaust channel, which is arranged in the furnace body, one end of which is connected to the third space, and the other end of which is connected to the outside of the furnace body, and the gas in the third space is discharged to the outside of the furnace body; and a gas supply channel, which is arranged in the furnace body, one end of which is connected to the third space, and the other end of which is connected to the outside of the furnace body, and the gas is supplied from the outside of the furnace body to the third space; the conveying device is configured such that the conveying speed of the processed object in the third space is greater than the conveying speed of the processed object in the first space, and also greater than the conveying speed of the processed object in the second space; and there is no partition wall in the third space. The heat treatment furnace of claim 1, wherein the partition wall further comprises: a first partition wall separating the first space and the third space; and a second partition wall separating the second space and the third space, and the dimension of the third space in the transport direction is smaller than the dimension of the first partition wall in the transport direction when the first temperature is higher than the second temperature. The heat treatment furnace of claim 1, wherein the partition wall further comprises: a first partition wall separating the first space and the third space; and a second partition wall separating the second space and the third space, and the dimension of the third space in the transport direction is smaller than the dimension of the second partition wall in the transport direction when the second temperature is higher than the first temperature. A heat treatment furnace as claimed in any one of claims 1 to 3, wherein a first heater and a second heater are provided in the furnace body, the first heater is arranged in the first space and can adjust the first space to the first temperature, the second heater is arranged in the second space and can adjust the second space to the second temperature, and no heater is provided in the third space.

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