WO2017104625A1

WO2017104625A1 - Heat treatment furnace and heat treatment method

Info

Publication number: WO2017104625A1
Application number: PCT/JP2016/086945
Authority: WO
Inventors: 孝彦橋本
Original assignee: 日本碍子株式会社; エヌジーケイ・キルンテック株式会社
Priority date: 2015-12-14
Filing date: 2016-12-12
Publication date: 2017-06-22
Also published as: KR20180093890A; CN108369068B; CN108369068A; TW201734395A; TWI696799B; JPWO2017104625A1; JP6754375B2

Abstract

A heat treatment furnace 10 is provided with a transport device 40 that transports an object to be treated 12. The transport path on which the object to be treated 12 is transported is divided into the following: a first transport section 42; a second transport section 44 provided adjacent to the first transport section 42; and a third transport section 46 provided adjacent to the second transport section 44. The transport device 40 includes a clutch mechanism 70 that switches between a first state in which the drive force of a first drive device 54 is transmitted to transport rollers 52 disposed within the second transport section 44, and a second state in which the drive force of a second drive device 56 is transmitted to the transport rollers 52 disposed within the second transport section 44 and to at least some of the transport rollers 52 disposed within the first transport section 42 and the third transport section 46.

Description

Heat treatment furnace and heat treatment method

This application claims priority based on Japanese Patent Application No. 2015-243488 filed on Dec. 14, 2015. The entire contents of that application are incorporated herein by reference. The technology disclosed in this specification relates to a heat treatment furnace and a heat treatment method for heat-treating an object to be processed. More specifically, the present invention relates to a technique for changing the conveyance speed for conveying a workpiece for each section.

There is a case where an object to be processed is heat-treated using a heat treatment furnace (for example, roller hearth kiln). In this type of heat treatment furnace, the interior of the furnace body is divided into a plurality of spaces, and the objects to be processed are sequentially conveyed through these spaces. The temperature profile of the object to be processed is adjusted by adjusting the atmospheric temperature of each space inside the furnace body and the time during which the object passes through each space (the conveyance speed in each space). For example, in the roller hearth kiln disclosed in Japanese Patent Application Laid-Open No. 2015-64189, the temperature difference between the atmospheric temperature of the first space and the atmospheric temperature of the second space is set large, and the object to be processed is transferred from the first space to the second space. Things are transported. In this roller hearth kiln, a high-speed conveyance section is provided between the first space and the second space, and the workpiece is conveyed at a higher speed in the high-speed conveyance section than in the first space and the second space. As a result, the object to be processed is transported from the first space to the second space in a short time, and is rapidly heated or lowered. Here, the pitch (interval) at which the conveyance rollers are arranged is set shorter than the dimension in the conveyance direction of the workpiece, and the workpiece is supported by a plurality of conveyance rollers. That is, the object to be processed is positioned on the plurality of transport rollers. If the object to be processed is arranged on a conveying roller driven at a different speed, there arises a problem that the object to be processed is inclined with respect to the conveying direction. For this reason, the conveyance roller in the high-speed conveyance section is driven at the same speed (low speed) as the conveyance roller in the first space until the workpiece is completely carried into the high-speed conveyance section from the first space. When the workpiece is completely carried into the high-speed conveyance section, the conveyance roller in the high-speed conveyance section is driven at high speed only while the workpiece is moved through the high-speed conveyance section. Then, until the workpiece is completely carried into the second space from the high speed conveyance section, the conveyance roller in the high speed conveyance section is driven at the same speed (low speed) as the conveyance roller in the second space. Therefore, in the roller hearth kiln disclosed in Japanese Patent Application Laid-Open No. 2015-64189, in the high-speed conveyance section, a variable-speed conveyance roller that can adjust the rotation speed by the output of the motor is installed, and the motor is changed according to the position of the object to be processed. The output is adjusted.

In the above-mentioned high-speed conveyance section of the roller hearth kiln, the motor output must be adjusted according to the position of the workpiece to control the rotation speed of the conveyance roller. However, a certain response time is required from the time when the control command value to the motor is changed until the rotation of the conveying roller reaches a desired speed, and considering the response time, There was a problem that it was necessary to set the conveyance speed.

This specification discloses a heat treatment furnace and a heat treatment method capable of switching at a high speed the rotation speed of a conveyance roller for conveying an object to be processed in a heat treatment furnace having a conveyance path divided into a plurality of conveyance sections.

The heat treatment furnace disclosed in this specification includes a transfer device that transfers an object to be processed. The transport path for transporting the workpiece includes a first transport section, a second transport section provided adjacent to the first transport section, and a third transport section provided adjacent to the second transport section. It is divided. The object to be processed is transported from the first transport section to the third transport section through the second transport section. The transport device is disposed in the first transport section, the second transport section, and the third transport section, and is disposed in the second transport section with a plurality of transport rollers arranged at intervals in the transport direction of the workpiece. A first driving device capable of driving the transported roller at a first speed, a transport roller disposed in the second transport section, and a transport roller disposed in the first transport section and the third transport section A second driving device capable of driving at least a part of the first driving device at a second speed different from the first speed, and a driving force of the first driving device is transmitted to a conveying roller disposed in the second conveying section. And the second driving device is transmitted to the transport rollers disposed in the second transport section and to at least a part of the transport rollers disposed in the first transport section and the third transport section. A clutch mechanism for switching between two states.

In the heat treatment furnace, the first state in which the driving force of the first driving device is transmitted to the conveying roller disposed in the second conveying section, and the driving force of the second driving device is disposed in the second conveying section. And a clutch mechanism that switches to a second state that is transmitted to at least a part of the transport rollers disposed in the first transport section and the third transport section. For this reason, the drive speed of the conveyance roller arrange | positioned in a 2nd conveyance area can be switched at high speed by controlling the said clutch mechanism. As a result, it is not necessary to change the rotation speeds of the first driving device and the second driving device, and therefore, the first driving device and the second driving device are arranged in the second transport section without considering the response time for changing the rotation speed of the driving device. The driving speed of the conveying roller can be set. The transport rollers that can be driven by the second drive device include at least a part of the transport rollers disposed in the first transport section and the third transport section. For this reason, for the first transport section and the third transport section, the second driving device may be able to drive only the transport rollers disposed in the first transport section, or the transport disposed in the third transport section. Only the rollers may be drivable, or the conveyance rollers disposed in each of the first conveyance section and the third conveyance section may be drivable.

In the first heat treatment method disclosed in the present specification, the object to be processed is heat-treated using a heat treatment furnace including a transfer device that transfers the object to be processed along the transfer path. The transport path includes a first transport section and a second transport section provided adjacent to the first transport section. The workpiece is transported from the first transport section to the second transport section. The transport device includes a plurality of transport rollers that are installed in the first transport section and the second transport section and are spaced apart in the transport direction of the object to be processed, and transport rollers disposed in the second transport section. The first speed v1 includes the first driving device that can be driven at the first speed v1, the transport roller disposed in the second transport section, and the transport roller disposed in the first transport section. A second driving device that can be driven at a different third speed v3; a first state in which the driving force of the first driving device is transmitted to the conveying rollers disposed in the second conveying section; and the power of the second driving device. Includes a clutch mechanism that switches between a first state and a second state that is transmitted to the transport rollers disposed in the second transport section. By setting the clutch mechanism to the second state, the first transport step in which the workpiece is transported in the first transport section, and after the first transport step, the clutch mechanism is changed from the second state to the first state. A second transport step in which the workpiece is transported through the second transport section.

In the above heat treatment method, the transfer speed of the object to be processed in the first transfer process is switched to the transfer speed of the object to be processed in the second transfer process by the clutch mechanism. For this reason, the conveyance speed of a to-be-processed object can be switched at high speed.

In the second heat treatment method disclosed in this specification, the object to be processed is heat-treated using a heat treatment furnace including a transfer device that transfers the object to be processed along the transfer path. The transport path includes a first transport section, a second transport section provided adjacent to the first transport section, and a third transport section provided adjacent to the second transport section. The object to be processed is transported from the first transport section to the third transport section through the second transport section. The transport device is disposed in the first transport section, the second transport section, and the third transport section, and is disposed in the second transport section with a plurality of transport rollers arranged at intervals in the transport direction of the workpiece. A first driving device capable of driving the transported roller at a first speed v1, a transport roller disposed in the second transport section, and a transport roller disposed in the third transport section. A second drive device that can be driven at a second speed v2 different from the first speed, a first state in which the driving force of the first drive device is transmitted to a transport roller disposed in the second transport section, And a clutch mechanism that switches between a second state in which the power of the two-drive device is transmitted to the transport rollers disposed in the second transport section and the third transport section. A first transport step in which the workpiece is transported in the first transport section, and a second transport in which the workpiece is transported in the second transport section by setting the clutch mechanism to the first state after the first transport step. And a third transport step in which the workpiece is transported through the third transport section by changing the clutch mechanism from the first state to the second state after the second transport step.

In the heat treatment method described above, the transfer speed of the object to be processed in the second transfer process is switched to the transfer speed of the object to be processed in the third transfer process by the clutch mechanism. For this reason, the conveyance speed of a to-be-processed object can be switched at high speed.

The figure which shows schematic structure of the heat processing furnace of an Example. The figure for demonstrating the structure of the conveying apparatus of the heat processing furnace of an Example. The figure which shows schematic structure of the clutch mechanism of the heat processing furnace of an Example. The figure which shows the pitch of a conveyance roller, and the diameter of a conveyance roller. The figure for demonstrating an example of the aspect by which a to-be-processed object is conveyed in the heat processing furnace of an Example. The figure for demonstrating the other example of the aspect by which a to-be-processed object is conveyed in the heat processing furnace of an Example. The figure which shows schematic structure of the partition of a modification, a 1st sensor, and a 2nd sensor.

The main features of the embodiment described below are listed. The technical elements described below are independent technical elements and exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Absent.

In the heat treatment furnace disclosed in the present specification, the second driving device is capable of driving at least a part of the transport rollers disposed in the second transport section and the transport rollers disposed in the third transport section. May be. The transport device may further include a third drive device that drives the transport rollers arranged in the first transport section at a third speed. The third driving device may be capable of being driven independently from the first driving device and the second driving device. According to such a configuration, it is possible to control the driving of the transport rollers disposed in the first transport section independently from the transport rollers disposed in the second transport section and the third transport section. That is, it becomes possible to control the conveyance speed of the workpiece in the first conveyance section independently from the conveyance speeds in the second conveyance section and the third conveyance section. For this reason, for example, when a situation such as meandering or a collision of a workpiece may occur, such a possibility is avoided by changing the conveyance speed of the workpiece in the first conveyance section. It becomes possible.

In the heat treatment furnace disclosed in this specification, the transfer device is configured to be able to continuously transfer the workpiece, and may further include a control device that controls the third drive device. When the control device is brought into the first state by the clutch mechanism and the workpiece is transported through the second transport section, the other other workpiece that is positioned upstream of the workpiece is in the second transport section. The driving speed of the conveying roller arranged in the first conveying section by the third driving device may be controlled so that the conveying roller is not conveyed. According to such a configuration, when the transport roller arranged in the second transport section is driven at the first speed, another object to be transported in the first transport section is in the second transport section. It can prevent being conveyed on the arranged conveyance roller. As a result, the object to be processed can be suitably transported from the first transport section to the second transport section.

In the heat treatment furnace disclosed in this specification, the plurality of transport rollers may be arranged with a predetermined pitch p in the transport direction. When the distance that the workpiece is transported in the second transport section is set to L, the first speed is v1, and the third speed is v3, the control device is controlled by the clutch mechanism. When the workpiece is transported through the second transport section in the first state and v3 ≧ p × v1 / 2L is established, the operation of the third drive device may be stopped. According to such a configuration, the first state is appropriately set by the clutch mechanism and the first speed v1 and the third speed v3 are appropriately set according to the distance L over which the workpiece is transported through the second transport section. The operation of the three-drive device is stopped, and the workpiece can be suitably transported from the first transport section to the second transport section.

The heat treatment method disclosed in the present specification may include a first sensor that detects that the workpiece has been transported to the first position set at the boundary between the first transport section and the second transport section. When the workpiece is detected by the first sensor, the second transport process may be performed by changing the clutch mechanism from the second state to the first state. According to such a structure, it can detect appropriately by the 1st sensor that the to-be-processed object was conveyed from the 1st conveyance area to the 2nd conveyance area. For this reason, the clutch mechanism can be switched from the second state to the first state at an appropriate timing.

In the heat treatment method disclosed in the present specification, the second conveying step may be performed by maintaining the first state for a predetermined time after the clutch mechanism is changed from the second state to the first state. According to such a configuration, the workpiece can be transported with the clutch mechanism in the first state for a predetermined time during which the workpiece is transported through the second transport section.

In the heat treatment method disclosed in the present specification, the transfer path may further include a third transfer section provided adjacent to the second transfer section. The object to be processed may be further transported from the first transport section through the second transport section to the third transport section. The conveyance device may further include a plurality of conveyance rollers that are installed in the third conveyance section and are arranged at intervals in the conveyance direction of the workpiece. And after a 2nd conveyance process, the to-be-processed object may further be provided with the 3rd conveyance process by which a 3rd conveyance area is conveyed.

In the case where the transport path includes the third transport section, the heat treatment furnace includes a second sensor that detects that the workpiece has been transported to the second position set at the boundary between the second transport section and the third transport section. It may be. When the workpiece is detected by the second sensor, the clutch mechanism is changed from the first state to the second state, and the third transport step may be executed. According to such a structure, it can detect appropriately by the 2nd sensor that the to-be-processed object was conveyed from the 2nd conveyance area to the 3rd conveyance area. For this reason, the clutch mechanism can be switched from the first state to the second state at an appropriate timing after the second transport step.

In the heat treatment method disclosed in the present specification, the heat treatment furnace has a communication passage that communicates the first transport section and the third transport section, and isolates the space on the first transport section side and the space on the third transport section side. A partition wall may be provided. The second conveyance section may be provided in the communication path. The first sensor may be provided in the vicinity of the wall surface of the partition wall on the first conveyance section side. According to such a configuration, the space on the first transport section side and the space on the third transport section side can be suitably isolated by the partition. Further, by providing the first sensor in the vicinity of the wall surface on the first conveyance section side of the partition wall, it is possible to appropriately detect that the workpiece has been conveyed to the vicinity of the wall surface on the first conveyance section side.

In the heat treatment method disclosed in this specification, the distance from the transport roller to the partition wall in the second transport section is H, and the thickness from the wall surface on the first transport section side to the wall surface on the third transport section side of the partition wall is w. Then, w> 2H may be satisfied. According to such a configuration, the space on the first transport section side and the space on the third transport section side can be more suitably isolated.

In the heat treatment method disclosed in the present specification, the heat treatment furnace is provided at the boundary between the first transfer section and the second transfer section, the first partition provided at the boundary between the first transfer section and the second transfer section, and the second transfer section and the third transfer section. And a second partition that is spaced from the first partition in the conveyance direction of the workpiece. The first sensor may be disposed on the first conveyance section side of the first partition or between the first partition and the second partition. According to such a configuration, the space on the first transport section side and the space on the third transport section side can be separated by the two partition walls and the space provided between these two partition walls. For this reason, the 1st sensor can be arranged not only in the 1st conveyance section side of the 1st partition but between the 1st partition and the 2nd partition.

In the heat treatment method disclosed in the present specification, the heat treatment furnace includes a second sensor that detects that the workpiece has been transported to the second position set at the boundary between the second transport section and the third transport section. Also good. When the workpiece is detected by the second sensor, the clutch mechanism may be changed from the first state to the second state, and the third conveying step may be performed. The second sensor may be arranged on the third conveyance section side of the second partition or between the first partition and the second partition. According to such a configuration, the second sensor can be disposed not only on the third conveyance section side of the second partition, but also between the first partition and the second partition.

In the heat treatment method disclosed in this specification, the plurality of transport rollers may be arranged with a predetermined pitch p in the transport direction. If the distance at which the workpiece is transported at the first speed v1 in the second transport section is L, in the first transport process, when v3 <p × v1 / 2L is established, the second transport section is arranged in the first transport section. The driving of the transport rollers arranged in the first transport section may be temporarily stopped when the transport rollers are continuously driven at the third speed and v3 ≧ p × v1 / 2L is established. . According to such a configuration, the first transport section is set in accordance with the distance L, the first speed v1, and the third speed v3 in which the workpiece is transported in the second transport section at the first speed v1. The case where the drive of the arranged conveyance roller is continued and the case where it is stopped can be appropriately selected. For this reason, a to-be-processed object can be suitably conveyed from a 1st conveyance area to a 2nd conveyance area, and can be heat-processed.

Hereinafter, the heat treatment furnace 10 according to the embodiment will be described with reference to the drawings. As shown in FIG. 1, the heat treatment furnace 10 includes a furnace body 20 and a transport device 40 that transports the workpiece 12. The heat treatment furnace 10 heat-treats the workpiece 12 while the workpiece 12 is transported through the furnace body 20 by the transport device 40.

The furnace body 20 is surrounded by a ceiling wall 20a, a bottom wall 20d, and

partition walls

20b and 20c, and includes

partition walls

22 and 23 therein. The internal space of the furnace body 20 is divided by

partition walls

22 and 23 into a first space 30, a second space 32, and a communication passage 36 that communicates the first space 30 and the second space 32. Specifically, the partition wall 22 is fixed to the ceiling wall 20a at a substantially intermediate position between the

partition walls

20b and 20c, and extends vertically downward from the ceiling wall 20a. The partition wall 23 is fixed to the bottom wall 20d at a position corresponding to the partition wall 22, and extends vertically upward from the bottom wall 20d. The interior of the furnace body 20 is divided into a first space 30 and a second space 32 with the

partition walls

22 and 23 as boundaries. The partition wall 22 and the partition wall 23 are separated from each other, and a communication passage 36 is provided in the space between the separation. An opening 24 is formed in the partition wall 20b of the furnace body 20, and an opening 26 is formed in the partition wall 20c. The workpiece 12 is transferred from the opening 24 into the heat treatment furnace 10 by the transfer device 40, passes through the communication path 36, and is transferred from the opening 26 to the outside of the heat treatment furnace 10. That is, the opening 24 is used as a carry-in port, and the opening 26 is used as a carry-out port.

The workpiece 12 transferred into the furnace body 20 is heat-treated while being transferred from the opening 24 to the opening 26. Examples of the workpiece 12 include a laminate in which a ceramic dielectric (base material) and an electrode are laminated. The workpiece 12 is, for example, a setter 14 (in the following specification, when it is necessary to distinguish between them, it is described by using alphabetical letters such as

setters

14a and 14b, and there is no need to distinguish them. Sometimes, it may be simply described as setter 14. When there is no need to distinguish other components having the same configuration, the alphabetical characters are omitted and the numbers are simply described as numbers. It is placed on and transported.

The first space 30 is surrounded by the ceiling wall 20a, the bottom wall 20d, the partition wall 20b, and the

partition walls

22 and 23. The first space 30 can maintain an atmospheric temperature different from that of the second space 32 by being blocked from the second space 32 by the

partition walls

22 and 23 in the furnace body 20. The first space 30 communicates with the outside of the heat treatment furnace 10 through an opening 24 provided in the partition wall 20 b, and communicates with the second space 32 through a communication passage 36 between the

partition walls

22 and 23. In the first space 30, a plurality of transport rollers 52 and a plurality of

heaters

34a, 34b are arranged. In the first space 30, a transport roller 52 disposed in the first transport section 42 and a transport roller 52 disposed in a part of the second transport section 44 are accommodated. The heaters 34a are arranged at equal intervals in the conveying direction at positions above the conveying rollers 52, and the heaters 34b are arranged at equal intervals in the conveying direction at positions below the conveying rollers 52. When the

heaters

34a and 34b generate heat, the first space 30 is heated.

The second space 32 is surrounded by the ceiling wall 20a, the bottom wall 20d, the partition wall 20c, and the

partition walls

22 and 23. The second space 32 can be maintained at a different atmospheric temperature from the first space 30 by being blocked from the first space 30 by the

partition walls

22 and 23 in the furnace body 20. The second space 32 communicates with the outside of the heat treatment furnace 10 through an opening 26 provided in the partition wall 20 c, and communicates with the first space 30 through a communication passage 36 between the

partition walls

22 and 23. In the second space 32, a plurality of transport rollers 52 and a plurality of

heaters

34c, 34d are arranged. In the second space 32, a transport roller 52 disposed in a part of the second transport section 44 and a transport roller 52 disposed in the third transport section 46 are accommodated. The heaters 34c are arranged at equal intervals in the conveying direction at positions above the conveying rollers 52, and the heaters 34d are arranged at equal intervals in the conveying direction at positions below the conveying rollers 52. As the

heaters

34c and 34d generate heat, the inside of the second space 32 is heated.

The boundary of the upper surface and the lower surface of the communication passage 36 is defined by the

partition walls

22 and 23. The communication passage 36 communicates the first space 30 and the second space 32. A plurality of transport rollers 52 are arranged in the communication path 36. Only the transport roller 52 disposed in the second transport section 44 is accommodated in the communication path 36. The workpiece 12 can be transported from the first space 30 to the second space 32 through the communication passage 36. Here, the distance (height) from the conveyance roller 52 arranged in the communication path 36 to the partition wall 22 is H, and the thickness (from the wall surface on the first space 30 side to the wall surface on the second space 32 side of the partition wall 22 ( The length of the partition wall 22 in the transport direction in FIG. At this time, the partition wall 22 is installed so that w> 2H is established. When the distance H is large or the thickness w is small, heat is easily transferred between the first space 30 and the second space 32 via the communication passage 36. When the above formula is established, the movement of heat between the first space 30 and the second space 32 via the communication passage 36 can be suppressed. For this reason, the change of the atmospheric temperature of the 1st space 30 and the atmospheric temperature of the 2nd space 32 can be suppressed.

The conveying device 40 conveys the workpiece 12 from one end on the opening 24 side of the first space 30 to the other end on the opening 26 side of the second space 32 through the communication passage 36. The workpiece 12 is transported in a state where it is placed on the setter 14. The transport path of the workpiece 12 by the transport device 40 is divided into a first transport section 42, a second transport section 44, and a third transport section 46.

The first transport section 42 is set from one end on the opening 24 side of the first space 30 to the first position 48 in the first space 30. The first position 48 is set in the first space 30 and in the vicinity of the

partition walls

22 and 23. The first position 48 is an intermediate position between the two adjacent transport rollers 52. As shown in FIG. 5A and FIG. 6A, the first sensor 16 is disposed in the vicinity of the first position 48 and adjacent to the partition wall 22. Specifically, when the rear end of the setter 14b in the conveying direction (right side in FIGS. 5 and 6) is located at the first position 48, the first sensor 16 is disposed at a position where the front end of the setter 14b is detected. . The first sensor 16 is a sensor for detecting the setter 14. For example, an optical sensor can be used as the first sensor 16, and the setter 14 can be detected based on whether or not the setter 14 blocks the optical path. When the first sensor 16 detects the setter 14, it can be determined whether or not the rear end of the setter 14 is positioned at the first position 48.

The second conveyance section 44 is set from the first position 48 set in the first space 30 to the second position 50 set in the second space 32 through the communication passage 36. The second position 50 is set in the second space 32 and in the vicinity of the

partition walls

22 and 23. As shown in FIGS. 5B and 6B, the second sensor 17 is disposed in the vicinity of the second position 50 and adjacent to the partition wall 22. Specifically, when the leading end of the setter 14b in the transport direction (right side in FIGS. 5 and 6) is located at the second position 50, the second sensor 17 is disposed at a position where the rear end of the setter 14b is detected. . The second sensor 17 can be configured similarly to the first sensor 16 and is a sensor for detecting the setter 14. When the second sensor 17 detects the rear end of the setter 14, it can be determined whether or not the front end of the setter 14 is located at the second position 50.

The third transfer section 46 is set from the second position 50 set in the second space 32 to the other end of the second space 32 on the partition wall 20c side.

The setter 14 is conveyed by the conveyance roller 52 with the workpiece 12 placed thereon. Note that the setter 14 has a flat plate shape in the present embodiment, but may be any material as long as it is transported by the transport roller 52 with the workpiece 12 placed thereon, and is not limited to the above embodiment. For example, a box-shaped setter can be used. The material of the setter 14 is not particularly limited. For example, the setter 14 can be made of alumina, mullite, or Si—SiC, and is preferably made of Si—SiC having excellent high-temperature strength. Si-SiC is a ceramic made dense by impregnating porous Si with metal Si. By using Si—SiC, the setter 14 is not easily deformed even at high temperatures, and it is possible to prevent the setter 14 from warping during conveyance. For this reason, it can prevent suitably that the setter 14 meanders also under high temperature. Further, since the setter 14 is not easily deformed even by a sudden temperature change, it can be suitably transported to spaces having different atmospheric temperatures.

The transport device 40 includes a plurality of transport rollers 52, a first drive device 54, a second drive device 56, a third drive device 58, and a clutch mechanism 70. With reference to FIG. 2, the structure of the conveying apparatus 40 is demonstrated.

The transport roller 52 is cylindrical and is installed in the first transport section 42, the second transport section 44, and the third transport section 46, and its axis extends in a direction orthogonal to the transport direction. The plurality of transport rollers 52 all have the same diameter, and are arranged at regular intervals with a constant pitch p (see FIG. 4) in the transport direction. The transport roller 52 is supported so as to be rotatable about its axis, and rotates when the driving force of the driving device is transmitted. The material of the transport roller 52 is not particularly limited. For example, it is preferable that the material is made of Si—SiC excellent in high temperature strength. By using Si—SiC, the deformation of the transport roller 52 is suppressed even at a high temperature, the diameters of the plurality of transport rollers 52 can be held substantially uniformly, and the warpage of the rollers can be suppressed. For this reason, the setter 14 can be prevented from meandering even at high temperatures, and the setter 14 can be transported suitably.

The first drive device 54 is a drive device (for example, a motor) that drives the transport roller 52 disposed in the second transport section 44. The first drive device 54 is connected to a conveyance roller 52 disposed in the second conveyance section 44 via a power transmission mechanism and a clutch mechanism 70. In this embodiment,

sprockets

72a and 72b, a chain 76, and a drive shaft 84 are used as a power transmission mechanism. As shown in FIG. 3, the

sprockets

72a and 72b are disposed so as to be rotatable at intervals in the transport direction. A chain 76 is bridged between the

sprockets

72a and 72b. A first drive unit 54 is connected to the sprocket 72a, and the rotation of the first drive unit 54 is transmitted to the sprocket 72a. A drive shaft 84 is connected to the chain 76 via a clutch mechanism 70. One transport roller 52 c is connected to the drive shaft 84. The conveyance roller 52c is connected to the

adjacent conveyance rollers

52b and 52d by driven

gears

86b and 86c. Hereinafter, similarly, the

adjacent conveyance rollers

52a and 52e are connected by the driven

gears

86a and 86d, and the rotation of the drive shaft 84 can be transmitted to all the conveyance rollers 52 arranged in the second conveyance section 44. . When the driving force of the first driving device 54 is transmitted to the transport roller 52 (arranged in the second transport section 44) via the power transmission mechanism, the transport roller 52 rotates at the first speed v1. . The driving force of the first driving device 54 is switched between a state where it is transmitted to the transport roller 52 disposed in the second transport section 44 and a state where it is not transmitted by a clutch mechanism 70 which will be described in detail later. The first drive device 54 is controlled by the control device 60.

The second drive device 56 is a drive device (for example, a motor) that drives the transport roller 52 disposed in the second transport section 44 and the transport roller 52 disposed in the third transport section 46. The second driving device 56 includes a transport roller 52 disposed in the second transport section 44 and the third transport section 46 via the power transmission mechanism and the clutch mechanism 70 (only the transport roller 52 in the second transport section 44). It is connected to the. Specifically,

sprockets

78a and 78b, a chain 82, and a drive shaft 84 are used as a power transmission mechanism for the transport roller 52 disposed in the second transport section 44. As shown in FIG. 3, the

sprockets

78a and 78b are disposed so as to be rotatable at intervals in the transport direction. A chain 82 is bridged over the

sprockets

78a and 78b. A second driving device 56 is connected to the sprocket 78a, and the rotation of the second driving device 56 is transmitted to the sprocket 78a. A drive shaft 84 is connected to the chain 82 via a clutch mechanism 70. The clutch mechanism 70 switches between a state where the rotation of the chain 76 is transmitted to the drive shaft 84 and a state where the rotation of the chain 82 is transmitted. In addition, each of the transport rollers 52f to 52j arranged in the third transport section 46 is engaged with the chain 82. Accordingly, the clutch roller 70 is switched between the state where the power of the second drive device 56 is transmitted and the state where it is not transmitted to the transport roller 52 disposed in the second transport section 44. On the other hand, the power of the second driving device 56 is constantly transmitted to the transport roller 52 disposed in the third transport section 46. When the driving force of the second driving device 56 is transmitted to the transport roller 52, the transport roller 52 rotates at the second speed v2. The second drive device 56 is controlled by the control device 60.

The third drive device 58 is a drive device (for example, a motor) that drives the transport roller 52 disposed in the first transport section 42. The third driving device 58 is connected to a conveyance roller 52 disposed in the first conveyance section 42 via a power transmission mechanism. As the power transmission mechanism, a known mechanism can be used. In this embodiment, a mechanism using a sprocket and a chain (the same mechanism as the mechanism for transmitting power to the transport roller 52 arranged in the third transport section 46) is used. It is used. When the driving force of the third drive device 58 is transmitted to the transport roller 52 (arranged in the first transport section 42) via the power transmission mechanism, the transport roller 52 is moved to the third speed v3 (in this embodiment, the second speed v3). The rotation speed is equal to the speed v2). The third drive device 58 is controlled by the control device 60. The first drive device 54, the second drive device 56, and the third drive device 58 can be driven independently of each other by the control device 60.

The clutch mechanism 70 will be described with reference to FIG. The driving force of the first driving device 54 or the second driving device 56 is selectively transmitted to the transport rollers 52 a to 52 e arranged in the second transport section 44 by the clutch mechanism 70.

As described above, the driving force of the first driving device 54 is transmitted to the sprocket 72a, and the driving force transmitted to the sprocket 72a is transmitted to the sprocket 72c via the chain 76. The driving force of the second driving device 56 is transmitted to the sprocket 78a, and the driving force transmitted to the sprocket 78a is transmitted to the sprocket 78c via the chain 82.

The clutch mechanism 70 is adjacent to the sprocket 72b that transmits the driving force of the first driving device 54, the cam clutch 74 adjacent to the sprocket 72b, the sprocket 78b that transmits the driving force of the second driving device 56, and the sprocket 78b. Cam clutch 80. The sprocket 72 b is engaged with the chain 76, and the sprocket 78 b is engaged with the chain 82. The rotation of the chain 76 (that is, the driving force of the first driving device 54) is transmitted to the sprocket 72b, and the rotation of the chain 82 (that is, the driving force of the second driving device 56) is transmitted to the sprocket 78b.

The

cam clutches

74 and 80 are ring-shaped members and have an outer ring and an inner ring. The cam clutch 74 is fixed to the sprocket 72b in the outer ring, and is fixed to the drive shaft 84 in the inner ring. The cam clutch 80 is fixed to the sprocket 78b in the outer ring, and is fixed to the drive shaft 84 in the inner ring. The

cam clutches

74 and 80 are configured such that the driving force from the outer ring can be transmitted to the inner ring, while the inner ring idles with respect to the outer ring so that the driving force from the inner ring is not transmitted to the outer ring. That is, the

cam clutches

74 and 80 can transmit the driving force from the

sprockets

72b and 78b to the drive shaft 84 when the outer ring presses the inner ring. On the other hand, when the force that presses the outer ring against the inner ring is released, the outer ring rotates idly with respect to the inner ring, and the transmission of the driving force from the

sprockets

72b and 78b to the drive shaft 84 (or from the drive shaft 84 to the

sprockets

72b and 78b) is impossible. It becomes. Therefore, by operating either one of the

cam clutches

74 and 80, the driving force is transmitted from the sprocket 72b to the driving shaft 84 and the driving force is transmitted from the sprocket 78b to the driving shaft 84. It is done. Specifically, when the cam clutch 74 is operated and the driving force of the sprocket 72b is transmitted to the drive shaft 84, the cam clutch 80 is not operated, and the driving force of the sprocket 78b is transferred from the drive shaft 84 to the cam clutch. Not transmitted to 80 inner rings. When the cam clutch 80 is activated and the driving force of the sprocket 78b is transmitted to the drive shaft 84, the cam clutch 74 is not activated, and the driving force of the sprocket 72b is changed from the drive shaft 84 to the inner ring of the cam clutch 74. Not transmitted to. Therefore, the driving force transmitted to the drive shaft 84 can be selected by switching the operating state of the

cam clutches

74 and 80. That is, when the cam clutch 74 is operated, the driving force transmitted to the sprocket 72 b is transmitted to the drive shaft 84. That is, the driving force of the first driving device 54 is transmitted to the driving shaft 84. When the cam clutch 80 is operated, the driving force transmitted to the sprocket 78b is transmitted to the drive shaft 84. That is, the driving force of the second driving device 56 is transmitted to the driving shaft 84.

In this way, by switching the drive speeds of the transport rollers 52a to 52e disposed in the second transport section 44 by the clutch mechanism 70, the rotational speeds of the first drive device 54 and the second drive device 56 are not changed. The rotation speed of the transport roller 52 can be changed. For this reason, it becomes possible to switch the rotational speed of the conveyance roller 52 at high speed.

Next, the operation of the heat treatment furnace 10 when heat treating the workpiece 12 will be described. In order to heat-treat the workpiece 12, first, the heaters 34 a to 34 d are operated to set the ambient temperature of the first space 30 and the second space 32 to a set temperature. Next, the setter 14 on which the workpiece 12 is placed is placed on the transport roller 52. By operating the transfer device 40 (that is, the first drive device 54, the second drive device 56, and the third drive device 58), the first space 30, the communication passage 36, and the second space 32 are opened from the opening 24 of the heat treatment furnace 10. The workpiece 12 is conveyed to the opening 26 of the heat treatment furnace 10 through the heat treatment furnace 10. As a result, the workpiece 12 is heat-treated. In the present embodiment, the conveyance speed v1 of the workpiece 12 in the second conveyance section 44 is set higher than the conveyance speed v2 (= v3) of the workpiece 12 in the first conveyance section 42 and the third conveyance section 46. . That is, when conveyance of the setter 14 (processed object 12) is started by the conveyance device 40, the control device 60 determines whether the first sensor 16 has detected the tip of the setter 14 from the output signal of the first sensor 16. To monitor. Until the leading edge of the setter 14 is detected by the first sensor 16, the control device 60 controls the clutch mechanism 70 so that the power of the second driving device 56 is disposed in the second transport section 44. To be transmitted to For this reason, all the conveyance rollers 52 of the conveyance apparatus 40 convey the setter 14 (processed object 12) with the same conveyance speed v2 (= v3). When the leading edge of the setter 14 is detected by the first sensor 16, the control device 60 controls the clutch mechanism 70 so that the power of the first driving device 54 is applied to the transport roller 52 disposed in the second transport section 44. It is assumed that it is transmitted. As a result, the power of the first driving device 54 is transmitted to the transport roller 52 disposed in the second transport section 44, and the setter 14 (the processing object 12) is transported at the transport speed v1 (> transport speed v2). . Next, the control device 60 monitors whether or not the second sensor 17 has detected the rear end of the setter 14 from the output signal of the second sensor 17. When the rear end of the setter 14 is detected by the second sensor 17, the control device 60 controls the clutch mechanism 70 so that the power of the second driving device 56 is disposed in the second transport section 44. To be transmitted to As a result, the rotational speed of the transport roller 52 arranged in the second transport section 44 is switched, and the setter 14 (the workpiece 12) is transported to the opening 26 of the heat treatment furnace 10 at the transport speed v2 (<transport speed v1). Is done.

As apparent from the above description, in the heat treatment furnace 10 of the present embodiment, the atmospheric temperature of the second space 32 is set higher than the atmospheric temperature of the first space 30. Further, the conveyance speed v <b> 1 of the workpiece 12 in the second conveyance section 44 is set higher than the conveyance speed v <b> 2 of the workpiece 12 in the first conveyance section 42 and the third conveyance section 46. As a result, the workpiece 12 can be rapidly heated from the atmospheric temperature of the first space 30 to the atmospheric temperature of the second space 32. For example, the heat treatment furnace 10 of the present embodiment can be operated under the following conditions. That is, the atmospheric temperature of the first space 30 is set to 500 ° C., and the atmospheric temperature of the second space 32 is set to 1000 ° C. At this time, the temperature difference (ΔT) between the first space 30 and the second space 32 is 500 ° C. Further, the distance (x) between the first sensor 16 and the second sensor 17 is 250 mm, and the first speed v1 is 3000 mm / min. Here, the temperature increase rate is calculated as a value obtained by dividing the temperature difference ΔT by the time (x / v1) that the workpiece 12 travels the distance x at the first speed v1, that is, ΔT × v1 / x. . When the heat treatment furnace 10 is operated under the above conditions, the rate of temperature increase is about 6000 ° C./minute, and the temperature of the workpiece 12 is rapidly increased from the atmospheric temperature of the first space 30 to the atmospheric temperature of the second space 32. Is possible. As is clear from the above description, the higher the first speed v1, the higher the temperature increase rate of the workpiece 12 is. In addition, the said operating condition is an example and is not limited to this.

Further, in the heat treatment furnace 10 of the present embodiment, the transport roller 52 in the second transport section 44 is the same as the transport roller 52 in the first transport section 42 until the first sensor 16 detects the tip of the setter 14. Rotate at a speed of. That is, until the setter 14 is completely transported into the second transport section 44, the rotation speed of the transport roller 52 in the second transport section 44 is not switched. When the setter 14 is placed on the transport roller 52 that rotates at different rotational speeds, the setter 14 is inclined with respect to the transport direction, causing the setter 14 to meander. In the present embodiment, since the rotation speed of the transport roller 52 in the second transport section 44 is switched after the setter 14 has completely moved to the second transport section 44, the setter 14 is prevented from meandering. it can.

Depending on the size of the transport speed v3 of the setter 14 in the first transport section 42, a part of the setter 14 transported in the first transport section 42 while the setter 14 is transported at high speed in the second transport section 44. May move onto the transport roller 52 in the second transport section 44. That is, in the heat treatment furnace 10 of the present embodiment, the setters 14 (the workpiece 12) are arranged side by side in the transport direction on the transport rollers 52, and the plurality of setters 14 are transported simultaneously by the transport rollers 52. For this reason, while the setter 14 is transported at high speed in the second transport section 44, a part of the setter 14 transported in the first transport section 42 (the setter 14 transported immediately after the setter 14 transported at high speed) There is a possibility of moving onto the transport roller 52 in the second transport section 44. Therefore, in the heat treatment furnace 10 of the present embodiment, the driving of the third driving device 58 that drives the transport roller 52 in the first transport section 42 is turned on in accordance with the transport speed v3 of the setter 14 in the first transport section 42− Control off. This will be described with reference to FIGS.

First, while the setter 14 is transported at high speed at the transport speed v1 in the second transport section 44, the setter 14 transported in the first transport section 42 (the setter 14 transported immediately after the setter 14 transported at high speed). A condition for moving onto the transport roller 52 in the second transport section 44 will be described. FIG. 4 is a view showing both the setter 14a that is transported to the second transport section 44 and starts transporting at high speed, and the setter 14b that is transported immediately after the setter 14a. The setter 14a is transported at the transport speed v1 while moving in the second transport section 44. Therefore, the time t during which the setter 14a is transported at the transport speed v1 is L / v1 (L is a distance at which the setter 14a is transported at high speed (shown in FIG. 5)). Therefore, the distance that the setter 14b moves while the setter 14a is conveyed at a high speed is v3 × L / v1. Here, the position of the setter 14b when the setter 14a starts high-speed conveyance is such that its tip is closer to the opening 24 than the intermediate position between the conveyance roller _52b2 and the conveyance roller _52a1 . That is, when the setter 14a and the setter 14b are arranged without gaps in the transport direction and are put into the heat treatment furnace 10 from the opening 24, the position of the tip of the setter 14b when the setter 14a starts high-speed transport is determined by the transport roller _52b2 and the transport roller. 52 _{a1 is} an intermediate position. Therefore, if the moving distance v3 × L / v1 of the setter 14b described above is smaller than p / 2 (p: interval (pitch) of the conveyance roller 52) (that is, if v3 × L / v1 <p / 2). the setter 14a while high-speed conveyance, setter 14b never rest on the conveying rollers _{52 a1} of the second transport section 44. That is, if v3 <(p / 2L) × v1, also continue to carry the setter 14b at a conveying speed v3, setter 14b during high-speed conveyance of the setter 14a never rest on the conveying rollers _{52 a1.} For this reason, in this embodiment, if v3 <(p / 2L) × v1, the transport roller 52 in the first transport section 42 is transported while the setter 14 is transported at high speed in the second transport section 44. Continue driving at speed v3. On the other hand, if v3 ≧ (p / 2L) × v1, while the setter 14 is being conveyed at high speed in the second conveyance section 44, the driving of the conveyance roller 52 in the first conveyance section 42 is stopped (conveyance speed v3). = 0). As a result, the setter 14b is prevented from being placed on the conveying roller _52a1 rotating at a high speed, and the meandering of the setter 14b is suppressed.

First, referring to FIG. 5, when v3 <(p / 2L) × v1, that is, while the setter 14 is being transported at high speed in the second transport section 44, it is arranged in the first transport section 42. The conveyance state of the workpiece 12 when the conveyance roller 52 is continuously driven will be described. FIG. 5A shows a point in time when the clutch mechanism 70 switches from the second state to the first state, and FIG. 5B shows a point in time when the clutch mechanism 70 switches from the first state to the second state. Show. That is, the transport roller 52 disposed in the second transport section 44 is driven at the transport speed v2 (= v3) until the state shown in FIG. When the first sensor 16 detects the tip of the setter 14b, the clutch mechanism 70 is activated and the setter 14b is transported at the transport speed v1 (> v2). And if the 2nd sensor 17 detects the rear end of the setter 14b, the clutch mechanism 70 will act | operate and the setter 14b will be in the state conveyed by the conveyance speed v2 (state of FIG.5 (b)). In FIG. 5, setters 14a to 14c indicate setters 14 that are continuously conveyed.

The process until the setter 14b is put into the first space 30 and the state shown in FIG. The setter 14 b is transported from the first transport section 42 toward the second transport section 44. At this time, since the second state is selected by the clutch mechanism 70 in the second transport section 44, the setter 14b is transported at the transport speed v2. For this reason, since the first transport section 42 is transported at the transport speed v3 (= v2), all the

sections

42, 44, and 46 are transported at the same transport speed v2. That is, this state is maintained until the first sensor 16 detects the leading end of the setter 14b in the transport direction (right direction in FIG. 5).

The setter 14a is located immediately upstream of the setter 14b (left side in FIG. 5). The setter 14a is transported in the first transport section 42 at a transport speed v3 (= v2) following the setter 14b. When the setter 14 b is detected by the first sensor 16, the tip of the setter 14 a substantially coincides with the first position 48.

The setter 14c is located immediately downstream of the setter 14b (on the right side in FIG. 5). The setter 14 c is transported from the second transport section 44 to the third transport section 46. At this time, since the second state is selected in the second transport section 44, the setter 14c is transported at the transport speed v2 (= v3). When the setter 14b is detected by the first sensor 16, the rear end of the setter 14c is located upstream from the second position 50 by the distance l3.

Next, the process from the state shown in FIG. 5A to the state shown in FIG. 5B will be described. The setter 14b is transported in the second transport section 44 at the transport speed v1. That is, when the tip of the setter 14b is detected by the first sensor 16, the clutch mechanism 70 is switched from the second state to the first state, and the setter 14b is transported at the transport speed v1. This state is maintained until the rear end of the setter 14b in the transport direction is detected by the second sensor 17 (the state shown in FIG. 5B). When the time at this time is t and the transport distance of the setter 14b is L, L = v1 × t is established.

On the other hand, the setter 14a is transported in the first transport section 42 at the transport speed v3 (= v2), and when the transport distance is l1, l1 = v3 × t is established. Here, when the distance l1 is larger than the half of the pitch p, the setter 14a is moved in the second transport section 44 while the transport roller 52 arranged in the second transport section 44 is driven at the transport speed v1. Will be in contact with the conveying roller 52 disposed in the area. Then, the setter 14a is placed on the transport roller 52 driven at the transport speed v1 and the transport roller 52 driven at the transport speed v3 (= v2). In this case, a slip may occur between the setter 14a and the transport roller 52, and the setter 14a may meander. In the example shown in FIG. 5, since v3 <(p / 2L) × v1, l1 <p / 2 is established. For this reason, the conveyance at the conveyance speed v3 of the setter 14a can be continued.

The setter 14c is transported in the third transport section 46 at the transport speed v2 (= v3), and when the transport distance is l3, l3 = v2 × t is established. Since the setter 14c is transported by the distance l3 (= l1), the distance between the setter 14c and the setter 14b is maintained. For this reason, the setter 14b is conveyed without colliding with the setter 14c.

Finally, the process from the state shown in FIG. 5B to the state shown in FIG. 5A will be described. When the second sensor 17 detects the rear end of the setter 14b, the clutch mechanism 70 is switched from the first state to the second state, so that the transport speed v2 (= v3) is reached in the second transport section 44. The transport section 42, the second transport section 44, and the third transport section 46 all have the same speed. This state is maintained until the first sensor 16 detects the setter 14a immediately upstream of the setter 14b.

The setter 14a (the state shown in FIG. 5B) is transported from the first transport section 42 to the second transport section 44. The setter 14a is transported through the first transport section 42 and the second transport section 44 at the transport speed v3 (= v2). Since this state is maintained until the tip of the setter 14a is detected by the first sensor 16, the setter 14a shown in FIG. 5B is conveyed to the position of the setter 14b shown in FIG. It becomes. At this time, the transport distance of the setter 14a is shorter than the length of one setter 14 (the dimension in the transport direction) by a distance l1.

The setter 14b (the state shown in FIG. 5B) is transported from the second transport section 44 to the third transport section 46 at the transport speed v2 (that is, the transport speed v3). At this time, since the setter 14b is transported the same distance as the setter 14a, the setter 14b shown in FIG. 5 (b) is transported to the position of the setter 14c in FIG. 5 (a).

The next setter 14 is continuously conveyed further upstream of the setter 14a shown in FIG. This setter 14 is conveyed to the state of the setter 14a in FIG. In this way, the state shown in FIG. 5B is changed to the state shown in FIG. Therefore, when the conveyance speed v3 is set to be smaller than (p / 2L) × v1, the workpiece 12 is continuously conveyed without stopping the driving of the conveyance roller 52 in the first conveyance section 42. Can do.

Referring to FIG. 6, when v3 ≧ (p / 2L) × v1, that is, when the clutch mechanism 70 is selecting the first state, the transport roller 52 arranged in the first transport section 42. The case of stopping the driving of will be described. In addition, the description which overlaps with the content demonstrated using FIG. 5 is abbreviate | omitted. FIG. 6A shows a time point when the clutch mechanism 70 switches from the second state to the first state, and FIG. 6B shows a time point when the clutch mechanism 70 switches from the first state to the second state. Show.

First, the process until the setter 14b is put into the first space 30 and the state shown in FIG. The

setters

14a and 14b are the same as those described with reference to FIG. The setter 14c is transported from the second transport section 44 to the third transport section 46 at the transport speed v2 (that is, the transport speed v3), and when the setter 14b is detected by the first sensor 16, the rear end of the setter 14c is It substantially coincides with the second position 50.

Next, the process from the state shown in FIG. 6A to the state shown in FIG. 6B will be described. Since the setter 14b is the same as the description using FIG. 5, detailed description is abbreviate | omitted.

The setter 14a stops in the state shown in FIG. 6A while the clutch mechanism 70 selects the first state when v3 ≧ p × v1 / 2L is established. As described above, during the time t when the transport roller 52 arranged in the second transport section 44 is driven at the driving speed v1, the distance l1 that the setter 14a is transported at the transport speed v3 is the pitch between the transport rollers 52. When the distance is larger than half the distance p, the setter 14a comes into contact with the transport roller 52 disposed in the second transport section 44. That is, when v3 ≧ p × v1 / 2L is established, the setter 14a may meander or may collide with the downstream setter 14b. For this reason, when the above expression v3 ≧ p × v1 / 2L is established, the operation of the third drive device 58 is stopped so that the setter 14a is not conveyed while the clutch mechanism 70 selects the first state. The Thus, the above possibility can be avoided in advance.

The setter 14c is transported in the third transport section 46 at the transport speed v2 (that is, the transport speed v3). For this reason, the setter 14c is located downstream from the second position 50 by the distance l3. Specifically, the rear end of the setter 14c is located on the third transport section 46 side further than the position separated from the second position 50 by 13 (= v2 × t) on the third transport section 46 side.

Finally, the process from the state shown in FIG. 6B to the state shown in FIG. 6A will be described. The setter 14a (the state shown in FIG. 6B) is transported from the first transport section 42 to the second transport section 44 at the transport speed v3. Since this is maintained until the setter 14a is detected by the first sensor 16, the setter 14a shown in FIG. 6B is transported to the position of the setter 14b shown in FIG. 6A. The transport distance of the setter 14a at this time is substantially the same as the length of the setter 14 (the dimension in the transport direction).

The setter 14b (the state shown in FIG. 6B) is transported from the second transport section 44 to the third transport section 46 at the transport speed v2 (that is, the transport speed v3). At this time, since the setter 14b is transported the same distance as the setter 14a, the setter 14b shown in FIG. 6 (b) is transported to the position of the setter 14c shown in FIG. 6 (a).

The next setter 14 is continuously conveyed further upstream of the setter 14a shown in FIG. This setter 14 is conveyed to the position of the setter 14a shown in FIG. In this way, the state shown in FIG. 6B is changed to the state shown in FIG. Therefore, when v3 ≧ p × v1 / 2L is established, while the clutch mechanism 70 selects the first state, the operation of the third driving device 58 is stopped to meander the setter 14 or between the setters 14. Collisions can be avoided. Thereby, the state of Fig.6 (a) and FIG.6 (b) can be repeated, and the to-be-processed object 12 can be heat-processed safely continuously.

In the embodiment described above, when v3 ≧ (p / 2L) × v1, while the setter 14 is being conveyed at high speed in the second conveyance section 44, the conveyance roller 52 in the first conveyance section 42 is driven. Although it stopped, it is not restricted to such a form. For example, when v3 ≧ (p / 2L) × v1, while the setter 14 is being transported at high speed in the second transport section 44, the transport speed of the setter 14 in the first transport section 42 is decreased to transport the transport roller 52. The driving may be continued. Even with such a configuration, the conveying speed of the setter 14 can be kept small, and therefore, the meandering of the setter 14 can be prevented.

In the above-described embodiment, the clutch mechanism 70 is switched to the second state after the setter 14 is detected by the second sensor 17, but the present invention is not limited to this configuration. For example, after the tip of the setter 14 is detected by the first sensor 16 and the clutch mechanism 70 is switched to the first state, the clutch mechanism 70 is moved only for a predetermined time during which the workpiece 12 is transported through the second transport section 44. The first state may be maintained. From the distance L of the second transport section 44 and the first speed v1, the time t during which the workpiece 12 is transported through the second transport section 44 at the first speed v1 can be calculated. For this reason, after the tip of the setter 14 is detected by the first sensor 16, the clutch mechanism 70 is maintained in the first state only for the time t, and the clutch mechanism 70 is switched to the second state after the time t has elapsed. it can. According to such a configuration, the clutch mechanism 70 is changed from the first state to the second state at an appropriate timing by controlling the time during which the clutch mechanism 70 maintains the first state without installing the second sensor 17. Can be switched to.

In the embodiment described above, the transport speed v3 of the first transport section 42 and the transport speed v2 of the third transport section 46 are the same speed, but the transport speed v3 and the transport speed v2 may be different. In this case, the setter 14 in the first transport section 42 is conveyed while the setter 14 is transported through the second transport section 44 so that the setters 14 do not collide with each other (that is, the setter 14 has an appropriate distance). What is necessary is just to control appropriately conveyance speed v3. The space formed in the heat treatment furnace 10 is not limited to the two

spaces

30 and 32, and may be divided into three or more spaces. Moreover, the conveyance area which conveys the to-be-processed object 12 is not restricted to the three

areas

42, 44, and 46, You may divide | segment into four or more conveyance areas.

In the above-described embodiment, the partition that separates the first space 30 and the second space 32 is configured by the single partition 22. However, the technology disclosed in the present specification is not limited to such a form. . For example, as shown in FIGS. 7A to 7D, the first space 30 and the second space 32 may be separated by two

partition walls

122a and 122b. The first partition wall 122a is disposed on the first space 30 side, and the second partition wall 122b is disposed on the second space 32 side. The first partition wall 122 a defines a boundary between the first transport section 42 and the second transport section 44 of the communication passage 36. The second partition wall 122 b defines the boundary between the second transport section 44 and the third transport section 46.

The first sensor 116 is disposed in the vicinity of the first partition wall 122a. Specifically, the first sensor 116 may be disposed on the first conveyance section 42 side (the position shown in FIGS. 7A and 7B) of the first partition 122a, or the first partition 122a. And the second partition wall 122b (positions shown in FIGS. 7C and 7D). 7A to 7D, the state of the clutch mechanism 70 can be switched depending on whether or not the first sensor 116 detects the leading end of the setter 14 in the transport direction.

The second sensor 117 is disposed in the vicinity of the second partition wall 122b. Specifically, the second sensor 117 may be disposed on the third conveyance section 46 side (the position shown in FIGS. 7A and 7C) of the second partition 122b, or the first partition 122a. And the second partition wall 122b (positions shown in FIGS. 7B and 7D). Even in such a case, the state of the clutch mechanism 70 can be switched by detecting the rear end of the setter 14 in the conveying direction by the second sensor 117. In the example shown in FIG. 7 as well, the clutch mechanism 70 is moved from the first state by controlling the second conveyance section 44 by the time during which the second conveyance section 44 is conveyed at the first speed v1 without installing the second sensor 117. You may switch to a 2nd state.

As mentioned above, although the specific example of the technique disclosed by this specification was demonstrated in detail, these are only illustrations and do not limit a claim. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology illustrated in the present specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.

Claims

A heat treatment furnace for heat treating a workpiece,
A transport device for transporting the workpiece,
The transport path for transporting the workpiece includes a first transport section, a second transport section provided adjacent to the first transport section, and a third transport provided adjacent to the second transport section. Divided into sections,
The object to be processed is transported from the first transport section through the second transport section through the third transport section,
The transfer device
A plurality of transport rollers that are installed in the first transport section, the second transport section, and the third transport section, and are arranged at intervals in the transport direction of the workpiece;
A first driving device capable of driving the transport roller disposed in the second transport section at a first speed;
The transport roller disposed in the second transport section and at least a part of the transport rollers disposed in the first transport section and the third transport section are different from the first speed. A second driving device capable of being driven at a second speed;
A first state in which a driving force of the first driving device is transmitted to the conveying roller disposed in the second conveying section; and the conveying roller in which the second driving device is disposed in the second conveying section. And a clutch mechanism for switching to a second state transmitted to at least a part of the transport rollers disposed in the first transport section and the third transport section.
The second driving device can drive at least a part of the transport roller disposed in the second transport section and the transport roller disposed in the third transport section,
The transport device further includes a third drive device that drives the transport roller disposed in the first transport section at a third speed,
The heat treatment furnace according to claim 1, wherein the third driving device can be driven independently from the first driving device and the second driving device.
The transport device is configured to be capable of continuously transporting the workpiece, and further includes a control device that controls the third drive device,
When the control device is brought into the first state by the clutch mechanism and the workpiece is transported through the second transport section, the other workpiece to be processed located immediately upstream of the workpiece is The heat treatment furnace according to claim 2, wherein a driving speed of the transport roller arranged in the first transport section by the third driving device is controlled so as not to be transported to the second transport section.
The plurality of transport rollers are arranged at a predetermined pitch p in the transport direction,
When the clutch mechanism is set to the first state and the distance to which the workpiece is transported in the second transport section is L, the first speed is v1, and the third speed is v3,
The control device is a case where the workpiece is transported through the second transport section by being brought into the first state by the clutch mechanism, and when v3 ≧ p × v1 / 2L is established, The heat treatment furnace according to claim 3, wherein the operation of the three-drive device is stopped.
A heat treatment furnace including a transfer device that transfers an object to be processed along a transfer path,
The transport path includes a first transport section and a second transport section provided adjacent to the first transport section,
The workpiece is transported from the first transport section to the second transport section,
The transfer device
A plurality of transport rollers installed in the first transport section and the second transport section and arranged at intervals in the transport direction of the workpiece;
A first driving device capable of driving the transport roller disposed in the second transport section at a first speed v1;
The transport roller disposed in the second transport section and the transport roller disposed in the first transport section can be driven at a third speed v3 different from the first speed v1. Two drive units;
A first state in which a driving force of the first driving device is transmitted to the conveying roller disposed in the second conveying section; and a power of the second driving device in the first conveying section and the second conveying. A method of heat-treating the workpiece using the heat-treatment furnace, comprising: a clutch mechanism that switches to a second state that is transmitted to the transport roller disposed in a section;
A first transport step in which the workpiece is transported through the first transport section by setting the clutch mechanism to the second state;
A second transport step in which the workpiece is transported through the second transport section by changing the clutch mechanism from the second state to the first state after the first transport step; A heat treatment method for an object to be treated.
The heat treatment furnace includes a first sensor that detects that the workpiece is transported to a first position set at a boundary between the first transport section and the second transport section,
6. The heat treatment method according to claim 5, wherein when the workpiece is detected by the first sensor, the second transporting step is performed by changing the clutch mechanism from the second state to the first state. .
The heat treatment method according to claim 6, wherein the second conveying step is executed by maintaining the first state for a predetermined time after the clutch mechanism is changed from the second state to the first state.
The transport path further includes a third transport section provided adjacent to the second transport section,
The object to be processed is adapted to be further transported through the third transport section from the first transport section through the second transport section,
The transport device further includes a plurality of transport rollers that are installed in the third transport section and are arranged at intervals in the transport direction of the workpiece.
The heat processing method of Claim 6 further equipped with the 3rd conveyance process by which the said to-be-processed object is conveyed in the said 3rd conveyance area after a said 2nd conveyance process.
The heat treatment furnace includes a second sensor that detects that the workpiece has been transported to a second position set at a boundary between the second transport section and the third transport section,
The heat treatment method according to claim 8, wherein when the object to be processed is detected by the second sensor, the clutch mechanism is changed from the first state to the second state, and the third transfer step is executed. .
The heat treatment furnace has a communication passage that connects the first transfer section and the third transfer section, and includes a partition that separates the space on the first transfer section side and the space on the third transfer section side. And
The second conveyance section is provided in the communication path;
The heat processing method of Claim 8 with which the said 1st sensor is provided in the wall surface vicinity of the said 1st conveyance area side of the said partition.
If the distance from the transport roller in the second transport section to the partition wall is H, and the thickness from the wall surface on the first transport section side to the wall surface on the third transport section side of the partition wall is w, w> 2H. The heat treatment method according to claim 10, wherein:
The heat treatment furnace
A first partition provided at a boundary between the first transport section and the second transport section;
A second partition wall provided at a boundary between the second transport section and the third transport section and disposed at an interval in the transport direction of the object to be processed with respect to the first partition wall. ,
The heat treatment method according to claim 8, wherein the first sensor is disposed on the first conveyance section side of the first partition or between the first partition and the second partition.
The heat treatment furnace includes a second sensor that detects that the workpiece has been transported to a second position set at a boundary between the second transport section and the third transport section,
When the workpiece is detected by the second sensor, the clutch mechanism is changed from the first state to the second state, and the third transport step is performed.
13. The heat treatment method according to claim 12, wherein the second sensor is disposed on the third conveyance section side of the second partition or between the first partition and the second partition.
The plurality of transport rollers are arranged at a predetermined pitch p in the transport direction,
When the distance that the workpiece is transported at the first speed v1 in the second transport section is L,
In the first conveying step, when v3 <p × v1 / 2L is established, the driving of the conveying rollers arranged in the first conveying section is continued at a third speed, and v3 ≧ p × v1 The heat treatment method according to any one of claims 5 to 13, wherein when / 2L is established, the driving of the transport roller disposed in the first transport section is temporarily stopped.
A heat treatment furnace including a transfer device that transfers an object to be processed along a transfer path,
The transport path includes a first transport section, a second transport section provided adjacent to the first transport section, and a third transport section provided adjacent to the second transport section. ,
The object to be processed is transported from the first transport section through the second transport section through the third transport section,
The transfer device
A plurality of transport rollers that are installed in the first transport section, the second transport section, and the third transport section, and are arranged at intervals in the transport direction of the workpiece;
A first driving device capable of driving the transport roller disposed in the second transport section at a first speed v1;
A second roller capable of driving the transport roller disposed in the second transport section and the transport roller disposed in the third transport section at a second speed v2 different from the first speed. A driving device;
A first state in which a driving force of the first driving device is transmitted to the conveying roller disposed in the second conveying section; and a power of the second driving device in the second conveying section and the third conveying. A method of heat-treating the workpiece using the heat-treatment furnace, comprising: a clutch mechanism that switches to a second state that is transmitted to the transport roller disposed in a section;
A first transport step in which the object to be processed is transported in the first transport section;
A second transport step in which the workpiece is transported through the second transport section by setting the clutch mechanism to the first state after the first transport step;
A third transport step in which the workpiece is transported through the third transport section by changing the clutch mechanism from the first state to the second state after the second transport step;
A heat treatment method for an object to be processed.