TWI806948B - Heat treatment furnace and manufacturing method thereof - Google Patents

Abstract

The heat treatment furnace system performs heat treatment on the processed object. The heat treatment furnace system includes: a heat treatment section including a space for heat-treating the object to be processed; and a plurality of conveying rollers arranged in the heat treatment section to convey the object to be processed. The warping direction of the plurality of branch conveying rollers provided in the heat treatment section changes periodically when the conveying rollers are viewed along the axial direction at the portion where the warping of the conveying rollers becomes the largest.

Description

Heat treatment furnace and manufacturing method thereof

The technology disclosed in this patent specification relates to a heat treatment furnace for heat treatment of an object to be processed and its manufacturing method.

The object to be processed is sometimes heat-treated using a heat treatment furnace (for example, a roller hearth furnace, etc.). Such a heat treatment furnace system includes a plurality of conveying rollers, and the object to be processed is conveyed by rotating the conveying rollers while the object to be processed is placed on the conveying rollers. For example, JP-A-2015-64189 discloses an example of a heat treatment furnace.

In such a heat treatment furnace, sometimes in order to improve productivity, a plurality of objects to be processed are arranged and placed on the conveyance roller in a direction (hereinafter also referred to as the second direction) perpendicular to the conveyance direction (hereinafter also referred to as the first direction) and these plural objects to be processed are simultaneously conveyed. In this case, a plurality of objects to be processed are carried into the heat treatment furnace at the same time in a state aligned in the second direction. In addition, a plurality of objects to be processed are conveyed in the heat treatment furnace by conveyance rollers, and then carried out from the heat treatment furnace. The plurality of objects to be processed arranged and arranged in the second direction should ideally be carried out from the heat treatment furnace at the same time because they are carried by the same conveyance roller. However, due to bending or the like due to the weight of the object to be processed, there is a difference in the conveying speed depending on where the object to be processed is placed in the conveyance roller. Therefore, there arises a problem that a plurality of objects to be processed arranged and placed in the second direction are not simultaneously unloaded from the heat treatment furnace. This problem is especially The heat treatment furnace with a long conveying distance of the processed object becomes remarkable.

This patent specification discloses a technique for reducing the difference in conveyance speed of a plurality of objects to be processed arranged and placed in a direction (second direction) that is horizontal and perpendicular to the conveyance direction.

The heat treatment furnace system disclosed in this patent specification performs heat treatment on the object to be treated. The heat treatment furnace system includes: a heat treatment section including a space for heat-treating the object to be processed; and a plurality of conveying rollers arranged in the heat treatment section to convey the object to be processed. The warping direction of the plurality of branch conveying rollers provided in the heat treatment section changes periodically when the conveying rollers are viewed along the axial direction at the portion where the warping of the conveying rollers becomes the largest.

In the above-mentioned heat treatment furnace, by periodically changing the warping direction of the conveyance rollers in the heat treatment section, the conveyance speed of a plurality of objects to be processed arranged and placed in a horizontal direction (second direction) perpendicular to the conveyance direction can be adjusted. Therefore, it is possible to reduce the difference in conveying speed depending on which position (position in the second direction) the object to be processed is placed on in the conveying rollers.

In addition, the manufacturing method of the heat treatment furnace disclosed in this patent specification is to manufacture a heat treatment furnace. The heat treatment furnace includes: a heat treatment section including a space for heat-treating the object to be processed; The warping direction; and the setting step, for the heat treatment part, the transfer roller is set so that the measured warping direction changes periodically.

In the manufacturing method of the above-mentioned heat treatment furnace, in the heat treatment section, the conveying rollers are installed so that the measured warpage direction changes periodically. Therefore, the conveyance speed of the plurality of objects to be processed arranged and loaded in the second direction can be adjusted, and the difference in conveyance speed depending on where the objects to be processed are loaded in the conveyance roller can be reduced.

10: Heat treatment furnace

12: Processed objects

20: Heat treatment department

22: outer wall

24: space

26: opening

28: opening

30: heater

32: heater

34: Moving in department

40: Moving out department

50: Handling device

52: Conveying roller

60: drive device

62: Control device

[ Fig. 1 ] is a diagram showing a schematic configuration of a heat treatment furnace according to an embodiment, and is a longitudinal sectional view when the heat treatment furnace is cut on a plane parallel to the conveying direction of the object to be processed.

[Fig. 2] A sectional view taken along line II-II in Fig. 1.

[ Fig. 3 ] is a diagram showing the location where the magnitude and direction of warping of the conveying roller were measured.

[Fig. 4] is a diagram schematically showing the state in which the warping directions of the conveying rollers have been adjusted. Fig. 4(a) shows the state in which the warping directions of adjacent conveying rollers are shifted by 90°, and Fig. 4(b) shows the state in which the warping directions of adjacent conveying rollers are shifted by 180°.

[Fig. 5] is a diagram for explaining the conveyance of the object to be processed in the case of large bending of the conveying roller. Fig. 5(a) shows the loading state of the processed object placed on the center of the conveying roller, and Fig. 5(b) shows the loading state of the processed object placed on the end of the conveying roller.

[FIG. 6] In the case of large deflection of the conveying rollers, schematically showing the conveying rollers in a state where the warping directions of adjacent conveying rollers are shifted by 90° and the object to be processed placed on the ends of the conveying rollers. FIGS. 6(a) to 6(d) show the states in which the conveying rollers are rotated by 90° each.

[Fig. 7] When the bending of the conveying roller is large, it schematically shows the conveying roller in the state where the warping direction of the adjacent conveying roller is shifted by 180°, and the object to be processed placed on the end of the conveying roller. Fig. 7(a) to Fig. 7(d) show the state that the conveying roller is rotated by 90°.

Main features of the embodiments described below are enumerated in advance. In addition, the technical elements described below are independent technical elements, which are technically useful alone or in various combinations, and are not limited to the combinations described in the scope of the patent application when applying for a patent.

(Feature 1) In the heat treatment furnace system disclosed in this patent specification, the plurality of conveying rollers provided in the heat treatment section may be constituted by a predetermined number of conveying rollers in one cycle. The warping direction of each conveying roller constituting one cycle may be shifted by a predetermined angle from the warping direction of the conveying roller adjacent to the conveying roller. According to such a configuration, the conveyance speed of a plurality of objects to be processed arranged and placed horizontally and vertically to the conveyance direction (second direction) can be appropriately adjusted. In particular, when the conveyance speed of the processed objects placed on the end side of the conveyance roller is faster than that of the processed objects placed near the center, the difference in the conveyed speeds of the plurality of processed objects arranged and placed in the second direction can be reduced.

(Feature 2) The heat treatment furnace system disclosed in this patent specification may further include a driving device capable of simultaneously driving a plurality of transfer rollers. The driving device can also maintain the state that the warping direction of the conveying roller and the warping direction of the adjacent conveying roller are staggered by a predetermined angle, and drive a plurality of conveying rollers. According to this structure, the plurality of conveying rollers are simultaneously driven by the driving device, thereby maintaining a state in which the warping directions of the plurality of conveying rollers and the warping direction of adjacent conveying rollers are deviated by a predetermined angle. Therefore, it is possible to maintain a state in which the conveyance speeds of the plurality of objects to be processed arranged and loaded in the second direction are adjusted.

(Feature 3) It is also possible that the predetermined angle of the heat treatment furnace system disclosed in this patent specification is 90 degrees. According to this structure, the conveyance speed of the plurality of objects to be processed arranged and conveyed in the second direction can be appropriately adjusted in accordance with the bending amount of the conveyance rollers. In particular, when the amount of deflection of the conveying roller when the object to be processed is placed on the conveying roller is small, the difference in conveying speed of a plurality of objects to be processed arranged and placed in the second direction can be reduced.

(Feature 4) It is also possible that the predetermined angle of the heat treatment furnace system disclosed in this patent specification is 180 degrees. According to this structure, the conveyance speed of the plurality of objects to be processed arranged and conveyed in the second direction can be appropriately adjusted in accordance with the bending amount of the conveyance rollers. In particular, when the amount of deflection of the conveyance roller is large when the object to be processed is placed on the conveyance roller, the difference in conveyance speed of a plurality of objects to be processed arranged and placed in the second direction can be reduced.

[Example]

Hereinafter, the heat treatment furnace 10 of the embodiment will be described. As shown in FIG. 1 , the heat treatment furnace 10 includes a heat treatment unit 20 , a carry-in unit 34 , a carry-out unit 40 , and a transfer device 50 . The heat treatment furnace 10 heat-treats the object to be processed 12 while the object to be processed 12 is conveyed within the heat treatment unit 20 by the conveyance device 50 .

As the object 12 to be processed, for example, a laminate in which a dielectric body (substrate) made of ceramics and electrodes are laminated, or a positive electrode material or a negative electrode material of a lithium ion battery, etc. are mentioned. When heat-treating the laminated body made of ceramics using the heat-treating furnace 10, these to-be-processed objects can be placed under the plate-shaped carrier plate, and can be conveyed in a furnace. Moreover, when using the heat treatment furnace 10 to heat-treat positive electrode materials or negative electrode materials of lithium ion batteries, these to-be-processed objects can be housed under a box-shaped sagger and transported in the furnace. In the heat treatment furnace 10 of this embodiment, it can be transported in a state where a plurality of carrier plates or saggers are arranged in the transport direction on the transport roller 52 (described later). Hereinafter, in this embodiment, the whole of the substance to be heat-treated, the carrier plate on which the substance to be heat-treated, or the sagger for storing the substance is referred to as "object to be processed 12". Also, in the following description, the direction in which the object 12 is conveyed (the direction perpendicular to the YZ plane of FIG. 1 ) is sometimes referred to as the “transportation direction” or the “first direction”, and the direction horizontal and perpendicular to the first direction (the direction perpendicular to the XZ plane of FIG. 1 ) is sometimes referred to as the “second direction”.

The heat treatment unit 20 includes a substantially rectangular box-shaped furnace body, and a space 24 surrounded by an outer wall 22 is provided inside the furnace body. On the front end surface of the outer wall 22 (the end surface on the -X side in FIG. 1 ), an opening 26 is formed, and on the rear end surface of the outer wall 22 (the end surface on the +X side in FIG. 1 ), an opening 28 is formed. The object 12 to be processed is transported from the opening 26 into the heat treatment section 20 by the transport device 50 , and then transported from the opening 28 to the outside of the heat treatment section 20 . That is, the opening 26 is used as the import port of the heat treatment unit 20 , and the opening 28 is used as the export port of the heat treatment unit 20 .

In the space 24, a plurality of branch conveying rollers 52 and a plurality of heaters 30, 32 are arranged. The heaters 30 are arranged above the conveying rollers 52 at equal intervals in the conveying direction, and the heaters 32 are arranged below the conveying rollers 52 at equal intervals in the conveying direction. The heaters 30 and 32 generate heat, The interior of the space 24 is heated. In addition, in this Example, although the heaters 30 and 32 were arrange|positioned at equal intervals in the conveyance direction, respectively, it is not limited to this structure. The heater may be appropriately changed to a desired position and arranged in accordance with, for example, the type of the object 12 to be processed or the conditions of the heat treatment of the heat treatment part 20 . Also, in this embodiment, the heaters 30 and 32 are arranged in the space 24, but the configuration is not limited to this. What is necessary is just to be able to heat in the space 24, for example, you may install a gas burner etc. in the space 24.

As shown in FIG. 2 , in the heat treatment unit 20 , a plurality of processed objects 12 are aligned in the second direction and conveyed. In the present embodiment, three objects to be processed 12 are arranged and conveyed in the second direction in the heat treatment section 20 (that is, the entire heat treatment furnace 10 ). Therefore, in this embodiment, the size of the heat treatment part 20 in the second direction is made larger than the size of the three processed objects 12 arranged in the second direction, but the size of the heat treatment part 20 in the second direction is not particularly limited. The size of the heat treatment unit 20 in the second direction may be such that more than three to-be-processed objects 12 can be arranged and conveyed in the second direction. Also, the size of the heat treatment unit 20 in the transport direction is relatively large, about 100 m, but the size of the heat treatment unit 20 in the transport direction is not particularly limited. For example, the size of the heat treatment unit 20 in the conveyance direction may be smaller than 100 m, may be 30 m to 100 m, or may be larger than 100 m. In addition, in the following description, when a plurality of processed objects 12 are arranged in the second direction, the central side in the second direction may be called "inner side", and the end side (+Y direction and -Y direction) in the middle of the second direction may be called "outer side". In addition, the to-be-processed object 12 is carried in continuously into the heat processing part 20 at predetermined intervals. Therefore, the processed objects 12 are arranged not only in the second direction but also in the conveyance direction.

In addition, as shown in FIG. 2, in this embodiment, among the three processed objects 12 arranged and placed in the second direction, the one placed on the +Y direction side in the second direction is regarded as the processed object 12a, the one placed in the center (inner side) of the second direction is regarded as the processed object 12b, and the one placed on the -Y direction side in the second direction is regarded as the processed object 12c to be distinguished. Hereinafter, regarding other constituent elements, subscript letters may be used when it is necessary to distinguish the constituent elements, and when it is not necessary to distinguish the constituent elements, the subscript letters may be omitted and only numbers may be described.

The carrying-in part 34 is located on the upstream side of the heat treatment part 20 (that is, the upstream side in the conveyance direction, In FIG. 1 is the -X direction of the heat treatment part 20). The carrying-in unit 34 receives the processed object 12 conveyed from the outside of the heat treatment furnace 10 , and then carries the received processed object 12 into the space 24 of the heat treatment unit 20 . The carrying-in part 34 is provided with the conveyance roller 52, and the to-be-processed object 12 conveyed from the exterior of the heat-processing furnace 10 is conveyed by the conveyance roller 52. As shown in FIG.

The carry-out unit 40 is located on the downstream side of the heat treatment unit 20 (that is, the downstream side in the conveyance direction, in the +X direction of the heat treatment unit 20 in FIG. 1 ). The unloading unit 40 unloads the processed object 12 from the space 24 of the heat treatment unit 20 , and delivers the unloaded processed object 12 to the outside of the heat treatment furnace 10 . Conveying rollers 52 are provided in the carrying out section 40 , and the object 12 to be processed is conveyed out of the space 24 by the conveying rollers 52 .

The conveying device 50 includes a plurality of conveying rollers 52 , a driving device 60 and a control device 62 . The transport device 50 transports the processed object 12 transported to the loading unit 34 from the loading unit 34 through the opening 26 into the space 24 of the heat treatment unit 20 . Furthermore, the conveyance device 50 is installed in the space 24 and conveys the object 12 to be processed from the opening 26 to the opening 28 . Furthermore, the conveyance device 50 conveys the processed object 12 from the space 24 to the carry-out unit 40 through the opening 28 . The processed object 12 is conveyed from the carry-in part 34 to the carry-out part 40 by the conveyance roller 52 .

The conveying roller 52 is cylindrical and its axis line extends in a direction perpendicular to the conveying direction. The plurality of conveying rollers 52 all have the same diameter, and are arranged at regular intervals in the conveying direction at equal intervals. In addition, the diameter of the conveyance roller provided in the heat treatment part 20 may differ from the diameter of the conveyance roller provided in the carrying-in part 34 and the carrying-out part 40. Moreover, the conveyance roller 52 provided in the heat treatment part 20 may be arrange|positioned at the pitch different from the conveyance roller 52 provided in the carrying-in part 34 and the carrying-out part 40. The conveying roller 52 is supported to be rotatable about its axis, and rotates by transmitting the driving force of the driving device 60 . A plurality of conveyance rollers 52 are arranged in the heat treatment unit 20 , the carrying-in unit 34 , and the carrying-out unit 40 . The dimension of the axial direction of the conveyance roller 52 is larger than the dimension of the 2nd direction of the heat treatment part 20 (refer FIG. 2).

The plurality of conveying rollers 52 disposed in the heat treatment section 20 are arranged so as to adjust the warpage direction (hereinafter also referred to as the warping direction of the conveying roller 52) of the position where the warpage becomes the largest among the plurality of locations in the axial direction of the conveying roller 52 when the respective conveying rollers 52 are viewed along the axial direction (that is, the second direction or the Y direction). as transport roller 52 The plurality of positions in the axial direction can be, for example, a position near the center of the conveying roller 52 and a position near the position where the conveying roller 52 contacts the end of each processed object 12 in the second direction when the conveying roller 52 is arranged in the second direction and a plurality of processed objects 12 are placed. In this embodiment, as shown in FIG. 3 , three objects to be processed 12 a to 12 c are arranged and placed on the conveying roller 52 in the second direction, so the vicinity of the end of the object to be processed 12 a (+Y direction side) is regarded as a site A, the vicinity of the boundary between the processed object 12 a and the processed object 12 b is regarded as a site B, the vicinity of the axial center of the conveying roller 52 is regarded as a site C, and the vicinity of the boundary between the processed object 12 b and the processed object 12 c is regarded as a site D. The vicinity of the end on the end side (-Y direction side) of the processed object 12c is regarded as a site E. As shown in FIG. Therefore, in this embodiment, the warping direction of the most warped part among the five axial positions A to E of the conveying roller 52 is taken as the warping direction of the conveying roller 52 . In addition, in this embodiment, the warping direction of the conveying roller 52 is set from the warping directions of the five positions A to E in the axial direction of the conveying roller 52, but the configuration is not limited to this. The warping direction of the conveying roller 52 may also be set according to the warping directions of more than five parts in the axial direction of the conveying roller 52 .

In this embodiment, the warping direction of the conveying roller 52 disposed in the heat treatment unit 20 is adjusted in a manner that varies according to the amount of bending of the conveying roller 52 that occurs when the object 12 is placed on the conveying roller 52 . To describe it in detail, it is provided so that the warping direction of the conveyance roller 52 changes periodically. That is, the conveyance roller 52 is arrange|positioned in the state which shifted predetermined angle with respect to the warping direction of the adjacent conveyance roller 52. Specifically, when the amount of curvature of the conveyance roller 52 is large, it is arranged so that the warpage direction of the adjacent conveyance roller 52 is shifted by 180°. Moreover, when the bending amount of the conveyance roller 52 is relatively small, it arrange|positions so that the warpage direction of the adjacent conveyance roller 52 may deviate by 90 degrees. By arranging in this way, the difference in the conveyance speed in the thermal processing part 20 of the several to-be-processed objects 12a-12c arranged and loaded in the 2nd direction can be made small.

The driving device 60 (see FIG. 1 ) is a driving device (for example, a motor) that drives the conveyance roller 52 . The driving device 60 is connected to the conveyance roller 52 via a power transmission mechanism. When the driving force of the driving device 60 is transmitted to the conveyance roller 52 via the power transmission mechanism, the conveyance roller 52 rotates. As a power transmission mechanism, it can With well-known person, for example, use the mechanism that is made of sprocket wheel and chain. The driving device 60 drives the respective conveying rollers 52 so that the conveying rollers 52 rotate at substantially the same speed. The driving device 60 is controlled by the control device 62 .

The plurality of conveying rollers 52 are rotated by transmitting the driving force of the driving device 60 . In this embodiment, the plurality of carrier rollers 52 connected to the same driving device 60 rotate simultaneously and at the same speed. Therefore, the plurality of conveying rollers 52 whose warping directions of the conveying rollers 52 have been adjusted as described above rotate while maintaining the adjusted warping directions. In addition, since it is preferable that the conveying rollers 52 installed in the heat treatment section 20 rotate at the same time and at the same speed, it is preferable to be connected to one driving device 60 . However, as shown in the heat treatment furnace 10 of this embodiment, when the distance in the transport direction of the heat treatment unit 20 is relatively long, it is difficult to rotate all the transport rollers 52 provided in the heat treatment unit 20 with one drive device 60 . In this case, a plurality of driving devices 60 are provided to generate the same driving force for the connected conveying rollers 52, and in order to drive all the conveying rollers 52 provided in the heat treatment part 20 with the same driving force, the conveying rollers 52 provided in the heat treatment part 20 are divided and connected to the plurality of driving devices 60. Thereby, all the conveyance rollers 52 provided in the heat treatment part 20 can be rotated by the same driving force and the same speed. At this time, the timing of the rotation of the conveying rollers 52 connected to different driving devices 60 is sometimes shifted, and between the conveying rollers 52 connected to different driving devices 60 (that is, between the conveying rollers 52 at the boundary), the adjusted warpage direction may not be maintained. Even in this case, since the conveying rollers 52 connected to the same driving device 60 can maintain the adjusted warping direction, the difference in the conveying speed of the heat treatment section 20 among the plurality of objects to be processed 12a-12c arranged and placed in the second direction can be reduced. In addition, the conveying rollers 52 provided in the loading section 34 and the carrying out section 40 may also be connected to a driving device that generates and drives a driving force different from that of the driving device 60 provided in the heat treatment section 20, and may also be configured to rotate at a speed different from that of the conveying rollers 52 provided in the heat treatment section 20.

Next, a method of manufacturing the heat treatment furnace 10 will be described with reference to FIGS. 3 and 4 . In addition, in this embodiment, the step of measuring the warping direction of the conveyance roller 52 and disposing the conveyance roller 52 in the heat treatment part 20 The steps are characteristic, and conventionally known steps can be used for other steps. Therefore, in the following, only the characteristic parts of this embodiment will be described, and descriptions of other steps will be omitted.

The manufacturing method of the heat treatment furnace 10 of the present embodiment includes: a measuring step of measuring the warpage direction of the portion where the warpage of the conveyance roller 52 becomes the largest when the conveyance roller 52 is viewed along the axial direction; and an installation step of setting the conveyance roller 52 so that the measured warpage direction changes periodically.

First, the warpage direction of the portion where the warpage of the conveyance roller 52 becomes the largest is measured for each of the plurality of branch conveyance rollers 52 by the measurement step. The measurement procedure was carried out according to the following procedures. First, both ends of the conveyance roller 52 are rotatably supported. For example, two V-blocks are used to support both ends of the conveyance roller 52 .

Next, using a measuring device such as a dial gauge, the magnitude of the warpage of each portion A to E in the axial direction of the conveying roller 52 is measured. Specifically, a dial gauge is installed at position A, and the conveying roller 52 is rotated once around the axis, and the difference between the conveying roller 52 at the uppermost position and the state without warping of the conveying roller 52 (hereinafter also referred to as the magnitude of warpage) is measured. For parts B~E, the same measurement as above is also carried out. After measuring the warpage of each part A~E, compare the measurement results of the 5 parts A~E, and determine the part with the largest warpage. Then, a mark 54 (see FIG. 4 ) indicating the warpage direction of the portion where the magnitude of warpage is the largest is provided on the end surface in the axial direction of the conveying roller 52 . Similarly, the warping direction of all the conveying rollers 52 installed in the heat treatment unit 20 is measured, and a mark 54 indicating the warping direction of the conveying rollers 52 is added to the axial end surface of each conveying roller 52 .

The conveyance roller 52 to which the mark 54 was attached is installed in the heat processing part 20 by the installation process. When installing the conveying rollers 52 in the heat treatment furnace 10, they are installed while adjusting the warping direction of each conveying roller 52 according to the mark 54 attached to each conveying roller 52 in the above-mentioned measuring step. In addition, in the present embodiment, it is characteristic that the warping direction of each conveyance roller 52 is adjusted while installing. Regarding other procedures of the installation steps, since conventionally known methods can be used, detailed descriptions of other procedures about the installation steps are omitted.

As mentioned above, the conveying rollers 52 installed in the heat treatment section 20 are arranged according to the direction of warping, but the configuration of the installation is based on the shape of the conveying rollers 52 generated when the object 12 is placed on the conveying rollers 52. The amount of bending varies. Therefore, depending on the weight of the object 12 to be heat-treated, the direction of warpage of the conveyance rollers 52 adjusted when installing the respective conveyance rollers 52 differs. Specifically, when the bending amount is large, each conveying roller 52 is installed so that the warping direction of the conveying roller 52 is shifted from that of the adjacent conveying roller 52 by 180° ( FIG. 4( b )). Moreover, when the bending amount is small, each conveying roller 52 is installed so that the warping direction of the conveying roller 52 and the warping direction of the adjacent conveying roller 52 are shifted by 90° ( FIG. 4( a )).

Next, the operation of the heat treatment furnace 10 when heat-treating the object 12 to be processed will be described. In order to heat-treat the object to be processed 12, first, the heaters 30 and 32 are operated, and the temperature of the ambient air in the space 24 is set to a set temperature. Next, the three to-be-processed objects 12 are respectively moved from the outside of the heat treatment furnace 10 onto the conveying rollers 52 provided in the carrying-in part 34 . At this time, three to-be-processed objects 12 are arranged and placed in the 2nd direction. Next, the driving device 60 is operated to transport the three processed objects 12 aligned in the second direction from the loading section 34 through the opening 26 into the space 24 of the heat treatment section 20 . The processed object 12 conveyed into the space 24 is conveyed from the opening 26 to the opening 28 in the space 24 . Thereby, the object to be processed 12 is heat-treated. Then, the heat-treated object 12 passes through the opening 28 , is conveyed to the carry-out unit 40 , and is carried out from the carry-out unit 40 .

The objects 12 to be processed are conveyed in a state where a plurality of objects (three in the present embodiment) are arranged in the second direction from the carrying-in part 34 to the carrying-out part 40 via the heat treatment part 20 . However, when the inlets of the heat treatment unit 20 are brought into the state in which the transport direction is aligned, a plurality of processed objects 12 are transported, and the transport speed of each of the plurality of processed objects 12 deviates during the transport of the heat treatment unit 20. This deviation is caused by deformation such as warpage that occurs during the manufacture of the conveyance roller 52 , or bending that occurs in the conveyance roller 52 when the object 12 is placed on the conveyance roller 52 due to the weight of the object 12 to be processed. According to experience, especially when the "curvature" of the conveyance roller 52 is greater than the "warpage" of the conveyance roller 52, the conveyance speed of the processed object 12 placed on the outer side (end side) of the conveyance roller 52 tends to be faster than the conveyance speed of the processed object 12 placed on the inner side (center) of the conveyance roller 52. This is considered to be based on the reasons shown below.

Since the conveying rollers 52 are warped or deformed during manufacture, all the conveying rollers 52 installed in the heat treatment furnace 10 cannot have exactly the same shape. When the "curvature" of the conveyance roller 52 is greater than the "warpage" of the conveyance roller 52, the influence of the "warpage" is offset by the "curvature" of the conveyance roller 52.

It demonstrates using FIG. 5. 5 schematically shows the processed object 12 placed on six conveying rollers 52. The six conveying rollers 52 are arranged in the order of conveying rollers 52a to 52f from upstream to downstream in the conveying direction (in the +X direction). Also, among the six conveying rollers 52a to 52f, the diameters of the conveying rollers 52a, 52c, and 52e are large, and the diameters of the conveying rollers 52b, 52d, and 52f are small. In addition, in FIG. 5, in order to clarify the difference in diameter, the difference of the diameter dimension of conveyance roller 52a, 52c, 52e and conveyance roller 52b, 52d, 52f is emphasized emphatically.

Here, since the conveyance roller 52 is supported at both ends, its "curvature" becomes larger at the center and becomes smaller at the ends. If the "curvature" of the conveying roller 52 is small, the object 12 to be processed will only contact the conveying roller 52 with a large diameter. On the other hand, if the "curvature" of the conveying roller 52 is large, the object 12 to be processed will bend the conveying roller 52 with a large diameter, and as a result, it will also come into contact with the conveying roller 52 with a small diameter.

As shown in Figure 5 (a), near the center of the conveying roller 52 is because the bending of the conveying rollers 52a, 52c, and 52e is large, so the processed object 12b is also in contact with other conveying rollers 52b, 52d, and 52f. That is, the object to be processed 12b comes into contact with all of the conveyance rollers 52a to 52f. On the other hand, as shown in Figure 5 (b), at the end of the conveying roller 52, because the bending of the conveying rollers 52a, 52c, and 52e is small, the processed objects 12a, 12c and the conveying rollers 52b, 52d, and 52f are not in contact. Therefore, at the end of the conveying rollers 52, the objects to be processed 12a, 12c are conveyed only by the conveying rollers 52a, 52c, 52e having a large radius of rotation. As a result, the conveying speed of the objects to be processed 12a, 12c becomes faster. On the other hand, in the state shown in Figure 5(a), because the bending of the conveying rollers 52a, 52c, and 52e is large, the object to be processed 12b is in contact with all the conveying rollers. 52a ~ 52f contact, and reduce the impact of the diameter of the transfer rollers 52a ~ 52f. As a result, the conveyance speed of the processed object 12 placed on the inner side of the conveyance roller 52 is slower than the conveyance speed of the processed object 12 placed on the outer side (end side) of the conveyance roller 52 .

Then, the conveying speed of the object 12 to be processed changes due to warping, bending, and uneven diameter of the conveying roller 52 . Therefore, the plurality of processed objects 12 arranged in the second direction may deviate in the conveyance direction while the heat treatment unit 20 conveys the processed objects 12 . In particular, as mentioned above, the heat treatment furnace 10 of the present embodiment is relatively long in the conveying direction of the heat treating section 20, so the plurality of processed objects 12 arranged and conveyed in the second direction tend to deviate in the conveying direction. When the plurality of processed objects 12 are not aligned in the second direction in the carrying out unit 40 , it is difficult to carry out the plurality of processed objects 12 to the outside of the heat treatment furnace 10 . Therefore, the warping direction of the conveyance roller 52 is adjusted so that the difference in conveyance speed in the heat treatment part 20 of the plurality of objects 12a to 12c arranged and placed in the second direction becomes small. Hereinafter, the adjustment of the warpage direction of the conveyance roller 52 provided in the heat treatment part 20 is demonstrated in more detail.

As described above, when the "curvature" of the conveyance roller 52 is greater than the "warpage" of the conveyance roller 52, the conveyance speed of the processed objects 12a and 12c placed outside the conveyance roller 52 tends to be faster than the conveyance speed of the processed object 12b placed inside the conveyance roller 52. As shown in the description with reference to FIG. 5 , it is considered that the processed objects 12b placed on the inner side of the conveying roller 52 are not easily affected by the warpage of the conveying roller 52 and the unevenness of the diameter of the conveying roller 52.

When the weight of the object to be processed 12 is heavy, the object to be processed 12b placed on the inside of the conveying roller 52 contacts all of the six conveying rollers 52 because the deflection of the conveying roller 52 becomes large near the center of the conveying roller 52. Therefore, the object 12b to be processed is always in the state shown in FIG. 5( a ) regardless of the warping direction of the conveyance roller 52 . Therefore, the object to be processed 12b is hardly affected by the warpage of the conveyance roller 52 and the unevenness of the diameter of the conveyance roller 52, and it is difficult to adjust the conveyance speed of the object to be processed 12b. Therefore, in order to make the conveying speed of the processed object 12b placed on the inner side of the conveying roller 52 the same as that of the object 12b placed on the outer side of the conveying roller 52 Since the difference between the conveyance speeds of the processed objects 12a and 12c becomes small, it is necessary to adjust the conveyance speeds of the processed objects 12a and 12c placed on the outer sides of the conveyance rollers 52 . That is, it is necessary to suppress an increase in the conveyance speed of the processed objects 12a and 12c.

Since the deflection of the conveying roller 52 is small at the end of the conveying roller 52, the processed objects 12a, 12c tend to be in a state of not contacting all of the six conveying rollers 52. For example, as shown in FIG. 6, the uppermost conveying roller 52 due to warping (the conveying roller 52 shown by a dotted line in FIG. 6) is pressed downward due to bending, but the conveying roller 52 is almost never bent to the position of the conveying roller 52 located at the lowermost due to warping. Therefore, it is difficult for the object 12 to be processed to come into contact with the conveyance roller 52 positioned at the bottom due to warping. But, as shown in Fig. 6 (a) ~ Fig. 6 (d), in the situation that disposes so that the warpage direction of adjacent conveying roller 52 is staggered each 90 °, is in any of the 4 kinds of situations that make conveying roller 52 rotate each 90°, and all to-be-processed objects 12a, 12c are in contact with more conveying rollers 52 among 6 conveying rollers 52 (4 or 5 conveying rollers 52 in the example of Fig. 6). Therefore, when the processed object 12 comes into contact with a relatively large number of conveyance rollers 52 , the influence of the variation in the diameter of the conveyance rollers 52 becomes stronger. As a result, when the warping directions of the adjacent conveyance rollers 52 are shifted by 90°, the conveyance speed of the objects 12a and 12c placed on the outside of the conveyance rollers 52 tends to increase.

On the other hand, as shown in Fig. 7 (a) ~ Fig. 7 (d), in the case of disposing so that the warping direction of the adjacent conveying rollers 52 is staggered by 180°, it is half of the four situations in which the conveying rollers 52 are rotated by 90° (in Fig. contact. Therefore, in Fig. 7(a) and Fig. 7(c), the number of conveying rollers 52 that are in contact with the processed objects 12a, 12c becomes relatively small, and the conveying form changes. According to the experiments of the present inventors, the situation shown in FIG. 7 suppresses the increase in the conveyance speed of the processed objects 12a, 12c placed on the outside of the conveyance roller 52 more than the situation shown in FIG.

Moreover, when the warping directions of the adjacent conveying rollers 52 are aligned, it becomes easy to contact all of the six conveying rollers 52 . Therefore, as in the case shown in FIG. 6, it is easy to be affected by the difference in the diameter of the conveying roller 52. Due to the influence of the uniformity, the conveyance speed of the processed objects 12a, 12c placed on the outside of the conveyance roller 52 tends to increase.

For the reasons as described above, it is considered that when the "curvature" of the conveyance roller 52 is greater than the "warpage" of the conveyance roller 52, and the amount of curvature of the conveyance roller 52 is large, by disposing so that the warpage directions of the adjacent conveyance rollers 52 are shifted by 180°, the difference in conveyance speed of the plurality of objects to be processed 12a to 12c arranged and placed in the second direction can be reduced.

Furthermore, the adjustment of the warping direction of the conveying roller 52 in the case where the weight of the object 12 to be processed is relatively light, although the "curvature" of the conveying roller 52 is larger than the "warping" of the conveying roller 52, will be described. When the weight of the object to be processed 12 is relatively light, it is because the bending amount of the conveying roller 52 becomes smaller, so the object to be processed 12b arranged at the center of the conveying roller 52 is in contact with a relatively large number of conveying rollers 52, but the objects to be processed 12a, 12c arranged at the ends of the conveying roller 52 are in contact with a relatively small number of conveying rollers 52. Therefore, the influence of "warpage" and "variation in diameter" of the conveying roller 52 on the processed object 12b arranged in the center of the conveying roller 52 is reduced, and it becomes difficult to adjust the conveying speed. On the other hand, the to-be-processed objects 12a, 12c arrange|positioned at the edge part side of the conveyance roller 52 strongly express the influence of the unevenness of diameter dimension. Therefore, when the warping direction of the conveyance roller 52 is not adjusted, the conveyance speed of the processed objects 12a, 12c placed outside the conveyance roller 52 tends to be faster than the conveyance speed of the processed object 12b placed inside the conveyance roller 52. Therefore, in order to reduce the difference in the conveyance speed of the processed objects 12a to 12c, it is necessary to increase the conveyance speed of the processed object 12b.

For example, when the warping directions of the adjacent conveying rollers 52 are shifted by 90°, when the conveying rollers 52 are located at the bottom due to warping, the conveying rollers 52 will hardly come into contact with the central processed object 12b. That is, in the same state as that shown in FIG. 6 , the frequency with which the radius of rotation of the conveyance rollers 52 becomes larger is higher than when all the conveyance rollers 52 are in contact with the object 12 to be processed. Therefore, when the warping directions of the adjacent conveyance rollers 52 are arranged so as to be shifted by 90°, the conveyance speed of the processed object 12b tends to increase. Similarly, when the warping directions of the adjacent conveyance rollers 52 are arranged so as to be shifted by 180°, the same state as that shown in FIG. 7 will be obtained. Therefore, compared with the state shown in FIG. 6, the conveyance speed of the object 12b is suppressed. speed becomes faster.

In addition, when the warping directions of the adjacent conveyance rollers 52 are aligned, compared with the case where the warpage directions of the adjacent conveyance rollers 52 are shifted by 180°, the conveyance speed of the processed object 12b is likely to be increased because it is easily affected by the uneven diameter of the conveyance rollers 52. However, since the conveying rollers 52 are curved, the object 12b is easily contacted with more conveying rollers 52 than when the warping directions of the adjacent conveying rollers 52 are shifted by 90°. Therefore, the conveyance speed of the object 12b placed on the inside of the conveyance rollers 52 tends to be faster when the warpage directions of the adjacent conveyance rollers 52 are shifted by 90° than when the warpage directions of the adjacent conveyance rollers 52 are aligned.

For the reasons as described above, it is considered that when the "curvature" of the conveyance roller 52 is larger than the "warpage" of the conveyance roller 52, and the amount of curvature of the conveyance roller 52 is small, by disposing so that the warpage directions of the adjacent conveyance rollers 52 are staggered by 90°, the difference in conveyance speed of the plurality of objects to be processed 12a to 12c arranged and placed in the second direction can be reduced.

In this embodiment, the warp direction of the conveyance roller 52 is adjusted according to the amount of curvature of the conveyance roller 52 that occurs when the object 12 is placed on the conveyance roller 52 . Thereby, the difference between the conveyance speed of the processed object 12b placed inside the conveyance roller 52 and the conveyance speed of the processed objects 12a and 12c placed outside the conveyance roller 52 can be reduced. Therefore, when the plurality of objects to be processed 12 arranged in the second direction in the heat treatment furnace 10 are transported to the unloading unit 40, the deviation in the conveyance direction can be reduced, and the heat treatment furnace 10 can be easily unloaded.

In addition, in this embodiment, when the "curvature" of the conveyance roller 52 is greater than the "curvature" of the conveyance roller 52, it is arranged so that the warpage directions of adjacent conveyance rollers 52 are shifted, but the configuration is not limited to this. It is only necessary that the conveyance speed of the processed objects 12a and 12c placed on the outside of the conveyance roller 52 be suppressed to be faster than the conveyance speed of the processed object 12b placed on the inner side of the conveyance roller 52, and it is only necessary that the warping directions of the plurality of conveyance rollers 52 change periodically. For example, two adjacent conveyance rollers 52 may be regarded as a unit, and the warping direction may be changed periodically. That is, the warping directions of the two adjacent conveying rollers 52 may be the same. The warping directions of the two conveying rollers 52 that are consistent and have the same warping direction are staggered by 90° or 180° from the warping directions of the adjacent two conveying rollers 52 . Also, when the number of conveying rollers 52 used to place one object 12 to be processed is large, the warpage directions of the three or more adjacent conveying rollers 52 may be the same, and the warping directions of the three or more conveying rollers 52 with the same warping direction may be staggered by 90° or 180° from the warping directions of the adjacent three or more conveying rollers 52.

Also, in the present embodiment, when the "curvature" of the conveyance roller 52 is greater than the "warpage" of the conveyance roller 52, it is arranged so that the warpage directions of adjacent conveyance rollers 52 are shifted by 90° or 180°, but it is not limited to this configuration. As long as the conveyance speed of the processed objects 12a, 12c placed on the outside of the conveyance roller 52 can be suppressed faster than the conveyance speed of the processed object 12b placed on the inner side of the conveyance roller 52, the angle at which the warping directions of the adjacent conveyance rollers 52 are shifted is not limited to the above-mentioned embodiment. For example, the warping directions of adjacent conveyance rollers 52 may be shifted by 45°, 72°, or 120°.

In addition, in this embodiment, the warpage direction of all the conveyance rollers 52 provided in the heat treatment part 20 is adjusted, but it is not limited to such a structure. It is only necessary to adjust the warping direction of the conveyance roller 52 so that the difference in conveyance speed in the heat treatment unit 20 of the plurality of objects 12 arranged and placed in the second direction becomes small.

As mentioned above, although the specific example of the technique disclosed in this patent specification was demonstrated in detail, these are merely illustrations, and do not limit the scope of claims. The technology described in the scope of claims includes various modifications and changes to the specific examples shown above. In addition, the technical elements described in the patent specification or drawings that exhibit technical usefulness alone or in various combinations are not limited to the combinations described in the claims at the time of patent application.

54: mark

Claims (5)

A heat treatment furnace is a heat treatment furnace for heat-treating an object to be processed, comprising: a heat treatment section including a space for heat-treating the object to be processed; a plurality of conveying rollers arranged in the heat-treating section to convey the object to be processed; and a driving device capable of simultaneously driving the plurality of conveying rollers, wherein the warping direction of the portion of the conveying rollers provided in the heat-treating section changes periodically when the warp of the conveying roller becomes the largest when viewed along the axial direction The driving device maintains a state in which the warping direction of the conveying roller and the warping direction of adjacent conveying rollers are deviated by a predetermined angle, and drives a plurality of conveying rollers. For example, in the heat treatment furnace of item 1 of the scope of the patent application, wherein the plurality of conveying rollers provided in the heat treatment section is constituted by a predetermined number of conveying rollers to form a cycle; the warping direction of each conveying roller constituting the one cycle is staggered by the predetermined angle from the warping direction of the conveying roller adjacent to the conveying roller. Such as the heat treatment furnace of claim 1 or 2 of the patent scope, wherein the predetermined angle is 90 degrees. Such as the heat treatment furnace of claim 1 or 2 of the patent scope, wherein the predetermined angle is 180 degrees. A method of manufacturing a heat treatment furnace, the heat treatment furnace comprising: a heat treatment section including a space for heat-treating an object to be processed; a plurality of conveying rollers arranged in the heat treatment section to convey the object to be processed; and a driving device capable of simultaneously driving the plurality of conveying rollers, the manufacturing method comprising: a measuring step of measuring the warpage of the portion where the warpage of the conveying roller becomes the largest when viewed along the axial direction for each of the plurality of conveying rollers installed in the heat treatment section curved direction; and The setting step is to set the conveying roller in the heat treatment part so that the measured warping direction changes periodically, and the driving device maintains the warping direction of the conveying roller and the warpage direction of the adjacent conveying roller in a state of staggering a predetermined angle, and drives a plurality of conveying rollers.