CN111566430A

CN111566430A - Heat treatment furnace and manufacturing method thereof

Info

Publication number: CN111566430A
Application number: CN201880085775.XA
Authority: CN
Inventors: 山田丰
Original assignee: NGK Insulators Ltd; NGK Kilntech Corp
Current assignee: NGK Insulators Ltd; NGK Kilntech Corp
Priority date: 2018-01-11
Filing date: 2018-12-26
Publication date: 2020-08-21
Anticipated expiration: 2038-12-26
Also published as: WO2019138890A1; JPWO2019138890A1; TWI800584B; CN111566430B; TW201930803A

Abstract

The invention provides a heat treatment furnace and a manufacturing method thereof. The heat treatment furnace performs heat treatment on the object to be treated. The heat treatment furnace is provided with: a heat treatment unit having a space for heat-treating an object to be treated; and a plurality of conveying rollers disposed in the heat treatment section and conveying the object to be treated. The plurality of conveying rollers disposed in the heat treatment section are classified into a plurality of groups based on the magnitude of the amount of warpage of the conveying rollers at the portion where the magnitude of warpage in the direction perpendicular to the axis is largest. Conveying rollers belonging to a group having a small average value of the warpage amount among the plurality of groups classified are arranged upstream in the conveying direction of the heat treatment section.

Description

Heat treatment furnace and manufacturing method thereof

Technical Field

The technology disclosed in the present specification relates to a heat treatment furnace for heat-treating an object to be treated and a method for manufacturing the same.

Background

The object to be treated may be heat-treated in a heat treatment furnace (e.g., a roller kiln). Such a heat treatment furnace is provided with a plurality of conveying rollers, and conveys an object to be treated by rotating the conveying rollers in a state where the object is placed on the conveying rollers. An example of a heat treatment furnace is disclosed in, for example, Japanese patent laid-open publication No. 2015-64189.

Disclosure of Invention

(problems to be solved by the invention)

The conveying rollers provided in such a heat treatment furnace are subjected to strain such as warping during the production thereof. Therefore, when the conveying rollers are installed in the heat treatment furnace, the conveying rollers that have a warpage amount equal to or greater than a predetermined value are excluded, and only the conveying rollers having a warpage amount within a predetermined range are used. However, even if the amount of warp is within a certain range, if there is a large difference in the magnitude of the amount of warp between the adjacent conveying rollers, transfer of the object to be processed to the adjacent conveying rollers during conveyance may not be smoothly performed, and there may be a problem in that the object to be processed bypasses. In particular, if this problem occurs near the entrance of the conveyance path, the subsequent conveyance is continuously affected, and therefore, this problem becomes significant in a heat treatment furnace in which the conveyance distance of the object to be treated is long. The present specification discloses a technique for smoothly conveying an object to be processed over the entire conveying path.

(means for solving the problems)

The heat treatment furnace disclosed in the present specification performs heat treatment on an object to be treated. The heat treatment furnace is provided with: a heat treatment unit having a space for heat-treating an object to be treated; and a plurality of conveying rollers disposed in the heat treatment section and conveying the object to be treated. The plurality of conveying rollers disposed in the heat treatment section are classified into a plurality of groups based on the magnitude of the amount of warpage of the conveying rollers at the portion where the magnitude of warpage in the direction perpendicular to the axis is largest. At the upstream end of the heat treatment section in the conveying direction, conveying rollers belonging to a group having the smallest average value of the warpage amounts among the plurality of groups classified are arranged.

In the heat treatment furnace described above, the conveyance rollers belonging to the group having the smallest average value of the warpage amount are arranged at the upstream end in the conveyance direction of the heat treatment unit, and thereby the conveyance disturbance of the object to be treated in the vicinity of the entrance of the conveyance path can be reduced. This reduces the disturbance of conveyance of the object to be processed in the entire conveyance path, and allows the object to be processed to be smoothly conveyed.

In addition, in the method for manufacturing a heat treatment furnace disclosed in the present specification, a heat treatment furnace is manufactured, and the heat treatment furnace includes: a heat treatment unit having a space for heat-treating an object to be treated; and a plurality of conveying rollers disposed in the heat treatment section and conveying the object to be treated. The method for manufacturing a heat treatment furnace comprises the following steps: a measuring step of measuring a warpage amount of a portion of each of a plurality of conveying rollers disposed in a heat treatment section, the portion having a largest warpage in a direction perpendicular to an axis of the conveying roller; a classifying step of classifying the plurality of conveying rollers into a plurality of groups based on the magnitude of the warpage amount measured in the measuring step; and an installation step of installing a conveying roller belonging to a group having the smallest average value of the warpage amounts among the plurality of groups classified, at an upstream end in the conveying direction of the heat treatment section.

In the above method of manufacturing a heat treatment furnace, the conveying rollers belonging to the group having the smallest average value of the warpage amounts among the plurality of groups classified are provided at the upstream end in the conveying direction of the heat treatment unit. Therefore, it is possible to reduce the disturbance of the conveyance of the object to be processed near the entrance of the conveyance path, and to smoothly convey the object to be processed in the entire conveyance path.

Drawings

Fig. 1 is a schematic diagram showing the structure of a heat treatment furnace according to examples 1 and 2, and is a vertical cross-sectional view when the heat treatment furnace is cut along a plane parallel to the conveyance direction of a material to be treated.

Fig. 2 is a sectional view taken along line II-II of fig. 1.

Fig. 3 is a view showing a portion where the amount of warp of the conveying roller is measured.

Fig. 4 is a view schematically showing conveying rollers disposed in a heat treatment section in example 1.

Fig. 5 is a view schematically showing conveying rollers disposed in a heat treatment section in example 2.

Detailed Description

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

(feature 1) in the heat treatment furnace disclosed in the present specification, the heat treatment unit may be configured such that the conveying rollers classified into the same group are collectively arranged in groups such that the conveying rollers are arranged in series in the conveying direction. The plurality of conveying rollers may be arranged such that an average value of the warpage amounts of the conveying rollers classified into the group becomes larger from upstream to downstream in the conveying direction when viewed in units of the group. According to this configuration, the conveying rollers classified into the same group are arranged continuously in the conveying direction, so that the difference in the magnitude of the warp between the adjacent conveying rollers can be reduced in the region where the conveying rollers classified into the same group are arranged in a concentrated manner. The plurality of groups classified are arranged such that the average value of the warpage amounts of the conveying rollers increases from upstream to downstream in the conveying direction. Therefore, the difference in the magnitude of the amount of warping of the conveying rollers can be reduced at the portions where the conveying rollers classified into different groups are adjacent. Further, a group of conveying rollers having a small amount of warp is provided on the upstream side in the conveying direction, and a group of conveying rollers having a large amount of warp is provided on the downstream side in the conveying direction. Therefore, the conveying rollers with a smaller warpage amount are arranged closer to the entrance of the conveying path, and the disturbance of the conveyance of the object to be processed can be reduced in the entire conveying path.

(feature 2) in the heat treatment furnace disclosed in the present specification, the plurality of conveying rollers disposed in the heat treatment unit may be classified into a plurality of large groups based on the material of the conveying rollers, and the conveying rollers classified into the plurality of large groups may be further classified into a plurality of small groups based on the amount of warping. The plurality of conveying rollers may be arranged continuously in the conveying direction for each of the major groups, and at least the conveying rollers belonging to the major group arranged on the upstream side may be arranged so that an average value of the warpage amounts of the plurality of minor groups belonging to the major group becomes substantially mountain-shaped from the upstream side to the downstream side in the conveying direction. According to this configuration, the conveying rollers of the same material are arranged in series, so that the conveying rollers of the same material are arranged in the heat treatment unit in a concentrated manner. For example, when the plurality of conveying rollers are classified into a1 st group including conveying rollers formed of a1 st material and a2 nd group including conveying rollers formed of a2 nd material having different characteristics from the 1 st material, the conveying rollers belonging to the 1 st group are arranged continuously in the conveying direction, and the conveying rollers belonging to the 2 nd group are arranged continuously in the conveying direction. The conveying rollers belonging to the large group disposed on the upstream side are disposed so that the average value of the warpage amounts of the conveying rollers becomes substantially mountain-shaped. For example, the average value of the warpage amounts of the conveying rollers is configured to gradually increase from upstream to downstream, and then gradually decrease from upstream to downstream. Therefore, in the portions where the conveying rollers classified into different large groups are adjacent to each other, the conveying rollers of the small group whose average value of the warpage amount becomes a relatively small value can be adjacent to each other. As a result, it is possible to avoid an increase in the difference in the magnitude of the warpage of the conveying rollers at these boundary portions. Therefore, the conveyance of the object to be processed can be made less complicated.

[ examples ] A method for producing a compound

(example 1)

The heat treatment furnace 10 according to example 1 will be described below. As shown in fig. 1, the heat treatment furnace 10 includes: a heat treatment unit 20, a loading unit 34, a loading unit 40, and a conveying device 50. The heat treatment furnace 10 performs heat treatment on the object 12 while the object 12 is conveyed by the conveying device 50 in the heat treatment unit 20.

Examples of the object 12 include a laminate in which a dielectric (base material) made of ceramic and an electrode are laminated, and a positive electrode material and a negative electrode material of a lithium ion battery. When the ceramic laminate is heat-treated in the heat treatment furnace 10, the ceramic laminate can be carried in a flat plate-like setter plate and conveyed in the furnace. When the positive electrode material and the negative electrode material of the lithium ion battery are heat-treated in the heat treatment furnace 10, they can be stored in a box-shaped magazine and transported in the furnace. In the heat treatment furnace 10 of the present embodiment, a plurality of setter plates and saggers can be placed on and conveyed by the conveying rollers 52 (described later) in a state of being aligned in the conveying direction. Hereinafter, in the present embodiment, the whole of the heat-treated material and the setter on which the heat-treated material is placed or the sagger which is stored is referred to as the "object to be treated 12". In the following description, a direction in which the object 12 is conveyed (a direction perpendicular to the YZ plane of fig. 1) may be referred to as a "conveying direction" or a "1 st direction", and a direction horizontal and perpendicular to the 1 st direction (a direction perpendicular to the XZ plane of fig. 1) may be referred to as a "2 nd 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. An opening 26 is formed in a front end surface (end surface on the-X side in fig. 1) of the outer wall 22, and an opening 28 is formed in a rear end surface (end surface on the + X side in fig. 1) of the outer wall 22. The object 12 to be processed is conveyed from the opening 26 into the heat treatment unit 20 by the conveying device 50, and is conveyed from the opening 28 to the outside of the heat treatment unit 20. That is, the opening 26 serves as a carrying-in port of the heat treatment section 20, and the opening 28 serves as a carrying-out port of the heat treatment section 20.

A plurality of conveying rollers 52 and a plurality of

heaters

30 and 32 are disposed in the space 24. The heaters 30 are disposed at equal intervals in the conveying direction at positions above the conveying rollers 52, and the heaters 32 are disposed at equal intervals in the conveying direction at positions below the conveying rollers 52. The space 24 is heated by the heat generated by the

heaters

30 and 32. In the present embodiment, the

heaters

30 and 32 are disposed at equal intervals in the conveying direction, but the present invention is not limited to this configuration. The heater may be appropriately changed and arranged at a desired position according to, for example, the type of the object 12 to be processed, the heat treatment conditions of the heat treatment unit 20, and the like. In the present embodiment, the

heaters

30 and 32 are disposed in the space 24, but the present invention is not limited to such a configuration. As long as the space 24 can be heated, for example, a gas burner or the like may be provided in the space 24.

As shown in fig. 2, in the heat treatment unit 20, a plurality of objects 12 to be treated are arranged in the 2 nd direction and conveyed. In this embodiment, 3 objects to be treated 12 are arranged in the 2 nd direction and conveyed in the heat treatment section 20 (i.e., the entire heat treatment furnace 10). Therefore, in the present embodiment, the dimension of the heat treatment unit 20 in the 2 nd direction is set to be larger than the dimension of 3 objects to be treated 12 arranged in the 2 nd direction, but the dimension of the heat treatment unit 20 in the 2 nd direction is not particularly limited. The dimension of the heat treatment unit 20 in the 2 nd direction may be such a size that 3 or more objects 12 to be treated can be arranged and conveyed in the 2 nd direction. The dimension of the heat treatment unit 20 in the conveyance direction is relatively large and is about 100m, but the dimension of the heat treatment unit 20 in the conveyance direction is not particularly limited. For example, the dimension of the heat treatment unit 20 in the conveyance direction may be less than 100m, may be 30m to 100m, or may be more than 100 m. The object 12 to be treated is continuously carried into the heat treatment unit 20 at predetermined intervals. Therefore, the objects 12 are arranged in a row not only in the 2 nd direction but also in the conveying direction.

As shown in fig. 2, in the present embodiment, among the 3 objects 12 placed in the 2 nd direction, the object to be treated placed on the + Y direction side in the 2 nd direction is defined as an object to be treated 12a, the object to be treated placed on the center in the 2 nd direction is defined as an object to be treated 12b, and the object to be treated placed on the-Y direction side in the 2 nd direction is defined as an object to be treated 12 c. Hereinafter, other components may be described using letters along a letter when the component needs to be distinguished, and may be described only by a numeral without letters along a letter when the component does not need to be distinguished.

The carrying-in unit 34 is located upstream of the heat treatment unit 20 (i.e., upstream in the carrying direction, which is the-X direction of the heat treatment unit 20 in fig. 1). The loading unit 34 receives the object 12 to be processed conveyed from the outside of the heat treatment furnace 10, and loads the received object 12 to be processed into the space 24 of the heat treatment unit 20. The carrying-in part 34 is provided with a conveying roller 52, and the object 12 to be treated conveyed from the outside of the heat treatment furnace 10 is conveyed by the conveying roller 52.

The carry-out section 40 is located on the downstream side of the heat treatment section 20 (i.e., on the downstream side in the conveying direction, which is the + X direction of the heat treatment section 20 in fig. 1). The carrying-out section 40 carries out the object 12 from the space 24 of the heat treatment section 20, and delivers the carried-out object 12 to the outside of the heat treatment furnace 10. The carrying-out section 40 is provided with a conveying roller 52, and the object 12 is conveyed out of the space 24 by the conveying roller 52.

The conveying device 50 includes: a plurality of conveying rollers 52, a drive device 60, and a control device 62. The conveying device 50 conveys the object 12 to be processed, which is conveyed to the carry-in part 34, from the carry-in part 34 into the space 24 of the heat treatment part 20 through the opening 26. Further, the conveying device 50 conveys the object 12 to be processed from the opening 26 to the opening 28 in the space 24. Then, the conveying device 50 conveys the object 12 to be processed from the space 24 to the carry-out section 40 through the opening 28. The object 12 to be processed is conveyed from the carry-in portion 34 to the carry-out portion 40 by the conveying roller 52.

The conveying roller 52 is cylindrical, and its axis 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. The diameter of the conveying rollers provided in the heat treatment unit 20 may be different from the diameter of the conveying rollers provided in the carry-in unit 34 and the carry-out unit 40. The conveying rollers 52 provided in the heat treatment unit 20 may be arranged at a different pitch from the conveying rollers 52 provided in the carry-in unit 34 and the carry-out unit 40. The conveying roller 52 is supported rotatably about its axis, and is rotated by transmission of the driving force of the driving device 60. A plurality of conveying rollers 52 are disposed in the heat treatment unit 20, the carrying-in unit 34, and the carrying-out unit 40, and all of the plurality of conveying rollers 52 are made of the same material. The material of the conveying rollers 52 provided in the carry-in section 34 and the carry-out section 40 may be different from the material of the conveying rollers 52 provided in the heat treatment section 20. The dimension of the conveying roller 52 in the axial direction is larger than the dimension of the heat treatment unit 20 in the 2 nd direction (see fig. 2).

The plurality of conveying rollers 52 disposed in the heat treatment unit 20 are classified into a plurality of groups and are collectively disposed in units of the classified groups. The groups into which the conveying rollers 52 are classified are determined based on the magnitude of the amount of warpage of the most warped portion (hereinafter, also referred to as the magnitude of the amount of warpage of the conveying rollers 52) among a plurality of portions in the axial direction of the conveying rollers 52 when the conveying rollers 52 are observed in the axial direction (i.e., the 2 nd direction or the Y direction). As the plurality of positions in the axial direction of the conveying roller 52, for example, a position near the center of the conveying roller 52 and a position near a position where the end in the 2 nd direction of each of the objects to be processed 12 comes into contact with the conveying roller 52 when the plurality of objects to be processed 12 are placed in the 2 nd direction on the conveying roller 52 in an aligned manner can be used. In the present embodiment, as shown in fig. 3, since 3 objects to be processed 12a to 12C are placed in a row in the 2 nd direction on the conveying roller 52, the vicinity of the end portion side (+ Y direction side) of the object to be processed 12a is defined as a region a, the vicinity of the boundary between the object to be processed 12a and the object to be processed 12B is defined as a region B, the vicinity of the center in the axial direction of the conveying roller 52 is defined as a region C, the vicinity of the boundary between the object to be processed 12B and the object to be processed 12C is defined as a region D, and the vicinity of the end portion side (-Y direction side) of the object to be processed 12C is defined as a region E. Therefore, in the present embodiment, the magnitude of the amount of warpage of the conveying roller 52 is set to the magnitude of the amount of warpage of the conveying roller 52, among the 5 portions a to E in the axial direction of the conveying roller 52. In the present embodiment, the amount of warpage of the conveying roller 52 is set according to the amount of warpage of the 5 positions a to E in the axial direction of the conveying roller 52, but the present invention is not limited to such a configuration. The amount of warpage of the conveying rollers 52 may be set based on the amount of warpage of more than 5 portions in the axial direction of the conveying rollers 52, or may be set based on the amount of warpage of less than 5 portions. Further, a plurality of positions in the axial direction may be set regardless of the position of the object 12 to be processed placed on the conveying roller 52.

In the present embodiment, the conveying rollers 52 disposed in the heat treatment unit 20 are classified into 5 groups based on the magnitude of the warpage amount. In each group, the range of the magnitude of the warp amount of the conveying roller 52 is set. For example, the conveying rollers 52 having the warpage amount of the conveying rollers 52 of less than 0.6mm are classified into the group G1, the conveying rollers 52 having the warpage amount of the conveying rollers 52 of 0.6mm or more and less than 1.0mm are classified into the group G2, the conveying rollers 52 having the warpage amount of the conveying rollers 52 of 1.0mm or more and less than 1.4mm are classified into the group G3, the conveying rollers 52 having the warpage amount of the conveying rollers 52 of 1.4mm or more and less than 1.8mm are classified into the group G4, and the conveying rollers 52 having the warpage amount of the conveying rollers 52 of 1.8mm or more are classified into the group G5. Since the range of the amount of warpage of the conveying rollers 52 is set in each of the groups G1 to G5, the number of conveying rollers 52 belonging to 5 groups G1 to G5 is not uniform.

In the present embodiment, the range of the magnitude of the warpage of the conveying roller 52 is set in each of the groups G1 to G5 as described above, but the present invention is not limited to this configuration. The conveying rollers 52 may be classified into a plurality of groups based on the size of the warpage amount, and for example, the range of the size of the warpage amount may be set so that the number of conveying rollers 52 classified into a plurality of groups is the same. The range of the magnitude of the warpage of the conveying rollers 52 in each of the groups G1 to G5 can be set as appropriate, and the above numerical range is only one example. In the present embodiment, the conveying rollers 52 are classified into 5 groups, but the present invention is not limited to such a configuration. The number of groups into which the conveying rollers 52 are classified can be appropriately determined based on the size of the conveying rollers 52, the total number of the conveying rollers 52 provided, and the like, and the number of groups into which the conveying rollers 52 are classified may be more than 5 or less than 5.

As shown in fig. 4, in the heat treatment unit 20, the conveying rollers 52 belonging to the group (i.e., group G1) having the smallest average value of the warpage amounts are arranged in a concentrated manner on the upstream side in the conveying direction, i.e., in the vicinity of the entrance of the heat treatment unit 20 (on the side of the-X direction in fig. 4). With this arrangement, the conveyance disturbance of the object to be processed 12 near the entrance of the heat treatment unit 20 can be reduced, and the conveyance disturbance of the object to be processed 12 can be reduced in the entire heat treatment unit 20.

Then, the conveying rollers 52 belonging to the group G1 having the smallest average value of the warpage amount (i.e., group G2) are arranged collectively downstream (on the + X direction side in fig. 4) of the conveying rollers 52 belonging to the group G1 having the smallest average value of the warpage amount. In this way, the conveying rollers 52 are arranged in a concentrated manner for each group so that the average value of the warpage amount becomes larger from the upstream to the downstream of the heat treatment section 20 (i.e., from the inlet to the outlet of the heat treatment section 20). Therefore, in the heat treatment section 20, when viewed from upstream to downstream in groups, the groups are arranged in the order of G1, G2, G3, G4, and G5. With this arrangement, the difference in the magnitude of the amount of warp of the conveying rollers 52 can be reduced at the portions where the conveying rollers 52 belonging to different groups are adjacent (for example, the portion where the conveying roller 52 belonging to the group G1 is adjacent to the conveying roller 52 belonging to the group G2). Further, since the conveying rollers 52 with a smaller warpage amount are disposed closer to the entrance of the heat treatment section 20, the conveyance disturbance of the object 12 to be treated can be reduced in the entire heat treatment section 20.

Further, in the group unit, the conveying rollers 52 belonging to the same group are arranged at random. Since the warpage amounts of the conveying rollers 52 belonging to the same group are within a certain range, the difference in the magnitude of the warpage amount between these conveying rollers 52 is small. Therefore, by arranging the conveying rollers 52 belonging to the same group in a concentrated manner, even if the conveying rollers 52 are arranged randomly in the group unit, it is possible to reduce the disturbance of the conveyance of the object 12.

The driving device 60 (see fig. 1) is a driving device (for example, a motor) that drives the conveying rollers 52. The driving device 60 is connected to the conveying rollers 52 via a power transmission mechanism. When the driving force of the driving device 60 is transmitted to the conveying rollers 52 via the power transmission mechanism, the conveying rollers 52 rotate. As the power transmission mechanism, a known power transmission mechanism can be used, and for example, a mechanism using a sprocket and a chain (not shown) can be used. The driving device 60 drives each of the conveying rollers 52 so that the conveying rollers 52 rotate at substantially the same speed. In the present embodiment, the driving device 60 drives the respective conveying rollers 52 so that the conveying rollers 52 rotate at substantially the same speed, but the present invention is not limited to such a configuration. For example, the heat treatment furnace 10 may be provided with a plurality of driving devices having different driving forces, and the conveying rollers 52 provided in the heat treatment unit 20 may be rotated at a speed different from the speeds of the conveying rollers 52 and 54 provided in the carry-in unit 34 and the carry-out unit 40 by the plurality of driving devices. The drive means 60 is controlled by a control means 62.

Next, a method for manufacturing the heat treatment furnace 10 will be described with reference to fig. 3 and 4. In the present embodiment, the characteristic is that the step of measuring the warpage amount of the conveying rollers 52, the step of classifying the plurality of conveying rollers 52 into groups, and the step of disposing the conveying rollers 52 in the heat treatment unit 20, and conventionally known steps can be used for other steps. Therefore, only the characteristic portions of the present embodiment will be described below, and the description of the other steps will be omitted.

The method for manufacturing the heat treatment furnace 10 of the present embodiment includes the steps of: a measuring step of measuring a warp amount of a portion of the conveying roller 52 where the warp in the direction perpendicular to the axis is largest; a sorting step of sorting the plurality of conveying rollers 52 into a plurality of groups based on the magnitude of the measured warpage amount; and an installation step of installing the conveying rollers 52 belonging to the group having a small amount of warpage in the vicinity of the entrance of the heat treatment section 20.

First, in the measurement step, the amount of warpage of the transport rollers 52 at the portion where warpage is the largest is measured for each of the plurality of transport rollers 52. The measurement step is performed by the following procedure. First, both ends of the conveying roller 52 are rotatably supported. For example, 2V-blocks are used to support both ends of the conveying roller 52.

Next, the warpage amount of each of the portions a to E in the axial direction of the conveying roller 52 is measured using a measuring instrument, for example, a dial gauge (see fig. 3). Specifically, a dial indicator is provided at the position a, the conveying roller 52 is rotated once around the axis, and the difference (hereinafter also referred to as the amount of warpage) between the uppermost position of the conveying roller 52 and the state where the conveying roller 52 is not warped is measured. The sites B to E were also measured in the same manner as above. After the warpage amounts of the respective portions a to E are measured, the measurement results of the 5 portions a to E are compared, and the warpage amount of the portion having the largest warpage amount among the warpage amounts of the portions a to E is set as the warpage amount of the conveying roller 52.

When the warpage amount of each of the conveying rollers 52 is measured, the conveying rollers 52 are classified into any one of the groups G1 to G5 through the classification step. Based on the magnitude of the warp amount of the conveying rollers 52 measured in the measuring step, the conveying rollers 52 are classified into any one of the groups G1 to G5.

When the plurality of conveying rollers 52 are classified into any one of the groups G1 to G5, the conveying rollers 52 belonging to the group G1 having the smallest average value of the warpage amount are disposed near the entrance of the heat treatment section 20 (i.e., the upstream end portion of the heat treatment section 20) in the disposing step (see fig. 4). At this time, all the conveying rollers 52 belonging to the group G1 are continuously provided in the heat treatment section 20. In the present embodiment, the conveying rollers 52 belonging to the group G1 are provided near the entrance of the heat treatment unit 20 (i.e., at the upstream end of the heat treatment unit 20), and a conventionally known method can be used for the other steps of the setting step, and therefore detailed description of the other steps of the setting step is omitted.

The setting step further includes a step of setting the conveying rollers 52 belonging to the other groups G2 to G5 on a group-by-group basis downstream of the conveying rollers 52 belonging to the group G1. At this time, when viewed in units of groups, the conveying rollers 52 are collectively provided for each group so that the average value of the amount of warping increases from the upstream side to the downstream side of the heat treatment section 20 (i.e., from the inlet to the outlet of the heat treatment section 20). Specifically, all the conveying rollers 52 belonging to the group G2 are disposed downstream of the conveying rollers 52 belonging to the group G1. Then, all the conveying rollers 52 belonging to the group G3 are disposed downstream of the conveying rollers 52 belonging to the group G2, and further, all the conveying rollers 52 belonging to the group G4 and all the conveying rollers 52 belonging to the group G5 are disposed downstream thereof in this order.

Next, the operation of the heat treatment furnace 10 when heat-treating the object 12 will be described. To heat-treat the object 12, first, the

heaters

30 and 32 are operated to set the atmospheric temperature of the space 24 to a predetermined temperature. Next, the 3 objects to be processed 12 are moved from the outside of the heat treatment furnace 10 to the conveying rollers 52 provided in the loading unit 34. At this time, 3 objects 12 to be processed are arranged and mounted in the 2 nd direction. Next, the driving device 60 is operated to convey 3 objects to be treated 12 aligned in the 2 nd direction from the carrying-in part 34 through the opening 26 into the space 24 of the heat treatment part 20. The object 12 to be processed conveyed into the space 24 is conveyed from the opening 26 to the opening 28 in the space 24. Thereby, the object 12 is heat-treated. Then, the heat-treated object 12 is conveyed to the carrying-out section 40 through the opening 28, and carried out from the carrying-out section 40.

Since the conveying rollers 52 are warped or distorted during the manufacturing process, all the conveying rollers 52 provided in the heat treatment furnace 10 cannot be formed in the same shape. Since the conveying rollers 52 are different in the magnitude of the amount of warpage, if the conveying rollers 52 are provided in the heat treatment unit 20 without considering the magnitude of the amount of warpage of the conveying rollers 52, a large difference may occur in the magnitude of the amount of warpage between the adjacent conveying rollers 52. If there is a difference in the magnitude of the amount of warp between the adjacent conveying rollers 52, the transfer of the object 12 cannot be smoothly performed, and the object 12 bypasses. In particular, in the heat treatment furnace 10 of the present embodiment, since the dimension in the conveyance direction of the heat treatment unit 20 is relatively long, if the object 12 detours near the entrance of the heat treatment unit 20, the distance over which the detouring effect continues becomes long.

In the present embodiment, the conveying rollers 52 are classified into a plurality of groups based on the magnitude of the warpage amount of the conveying rollers 52, and the conveying rollers 52 belonging to a group having a small average value of the warpage amount are disposed in the vicinity of the inlet of the heat treatment unit 20. This can reduce the disturbance of conveyance of the object to be processed 12 near the entrance of the conveyance path. Therefore, the conveyance of the object 12 can be performed smoothly with less disturbance in the entire conveyance path.

In the present embodiment, the conveying rollers 52 are disposed so that the average value of the warpage amounts becomes larger from the upstream side to the downstream side of the heat treatment unit 20, but the present invention is not limited to such a configuration. For example, the conveying rollers 52 belonging to the group G1 in which the average value of the warpage amount is smallest may be arranged near the entrance of the heat treatment section 20, and the remaining conveying rollers 52 (i.e., the conveying rollers 52 belonging to the groups G2 to G5) may be arranged randomly downstream thereof. Even with such a configuration, conveyance disturbance near the entrance of the conveying roller 52 can be reduced, and conveyance disturbance of the object to be processed 12 can be reduced in the entire conveyance path.

(example 2)

In the heat treatment furnace 10 of embodiment 1 described above, the conveying rollers 52 made of the same material are provided in the heat treatment unit 20, but the structure is not limited to this. For example, the conveying

rollers

52a and 52b of different materials may be provided in the heat treatment unit 20. In the heat treatment furnace 10 of the present embodiment, the structure of the conveying

rollers

52a and 52b provided in the heat treatment unit 20 is different from the structure of the conveying rollers 52 provided in the heat treatment unit 20 of embodiment 1, and is substantially the same as the other structures. Therefore, the same structure as that of the heat treatment furnace 10 of example 1 will not be described.

In the present embodiment, the plurality of conveying

rollers

52a, 52b provided in the heat treatment section 20 are classified into 2 major groups based on their materials, and further into a plurality of minor groups based on the magnitude of the amount of warping. First, the conveying

rollers

52a and 52b are classified based on their material. Specifically, the conveying

rollers

52a and 52b are classified into 2 groups, i.e., a group Ga to which the conveying roller 52a belongs and a group Gb to which the conveying roller 52b made of a different material from that of the conveying roller 52a belongs. For example, the conveying roller 52a may be formed of a material of the 1 st material, and the conveying roller 52b may be formed of a material of the 2 nd material different from the 1 st material. By changing the material of the conveying rollers 52 according to the position of the heat treatment unit 20, characteristics corresponding to the position of the heat treatment unit 20 can be provided to the conveying rollers 52.

The conveying

rollers

52a, 52b classified into the large groups Ga, Gb are further classified based on the magnitude of the amount of warp. Here, the number of the small groups into which the conveying rollers 52a classified into the large group Ga are further classified may be different from the number of the small groups into which the conveying rollers 52b classified into the large group Gb are further classified, and may be appropriately determined based on the material of the conveying

rollers

52a, 52b, the number of the conveying

rollers

52a, 52b provided, and the like. For example, the

conveyance rollers

52a and 52b may be classified into a large group when the number of the

conveyance rollers

52a and 52b provided in the heat treatment unit 20 is large, and may be classified into a small group when the number of the

conveyance rollers

52a and 52b provided in the heat treatment unit 20 is small. In the present embodiment, the conveying rollers 52a are provided in a large number in the heat treatment unit 20, and the conveying rollers 52b are provided in a small number in the heat treatment unit 20. Therefore, the conveying rollers 52a classified into the large group Ga are further classified into 5 small groups based on the magnitude of the warpage amount, and the conveying rollers 52b classified into the large group Gb are further classified into 3 small groups based on the magnitude of the warpage amount. Specifically, the conveying rollers 52a belonging to the large group Ga are further classified into the groups Ga1 to Ga5 in order of the average value of the magnitudes of the warpage, and the conveying rollers 52b belonging to the large group Gb are further classified into the groups Gb1 to Gb3 in order of the average value of the magnitudes of the warpage.

As shown in fig. 5, the conveying rollers 52a belonging to the large group Ga and the conveying rollers 52b belonging to the large group Gb are arranged in the heat treatment unit 20 in series. Specifically, the conveying rollers 52a belonging to the large group Ga are arranged continuously on the upstream side in the conveying direction of the heat treatment unit 20, and the conveying rollers 52b belonging to the large group Gb are arranged continuously on the downstream side in the conveying direction of the heat treatment unit 20. With this arrangement, the conveying

rollers

52a and 52b made of the same material can be arranged successively. Therefore, for example, when the atmosphere in the heat treatment unit 20 is changed according to the location, the conveying

rollers

52a and 52b having characteristics suitable for the respective atmospheres can be arranged according to the location of the heat treatment unit 20.

The arrangement of the conveying rollers 52a belonging to the large group Ga (i.e., the small groups Ga1 to Ga5) arranged on the upstream side in the conveying direction of the heat treatment unit 20 will be further described. In the vicinity of the entrance of the heat treatment section 20, the conveyance rollers 52a belonging to the group Ga1 having the smallest average value of the warpage amounts among the groups Ga1 to Ga5 are arranged in a concentrated manner. With this arrangement, the conveyance disturbance of the object to be processed 12 near the entrance of the heat treatment unit 20 can be reduced, and the conveyance disturbance of the object to be processed 12 can be reduced in the entire heat treatment unit 20.

The conveying rollers 52a belonging to the large group Ga are arranged collectively in groups such that the average value of the warpage amounts becomes substantially mountain-shaped from the upstream to the downstream of the heat treatment unit 20 (i.e., from the inlet to the outlet of the heat treatment unit 20). In the present specification, when the average value of the warpage amounts of the subgroups Ga1 to Ga5 is patterned in the order of arrangement from the inlet to the outlet of the heat treatment section 20, a shape having a 1-point bending point (i.e., an inflection point) is referred to as a "substantially mountain shape". Specifically, the average value of the warpage amounts gradually increases from the inlet toward the outlet, and then gradually decreases from the inlet toward the outlet. In the present embodiment, the conveying rollers 52a belonging to subgroup Ga3 are arranged downstream of the conveying rollers 52a belonging to subgroup Ga1, and further, the conveying rollers 52a belonging to subgroup Ga5 are arranged downstream thereof. Then, the conveying rollers 52a belonging to the group Ga4 are disposed downstream of the conveying rollers 52a belonging to the group Ga5, and further, the conveying rollers 52a belonging to the group Ga2 are disposed downstream thereof. Therefore, when viewed in units of groups, the groups Ga1, Ga3, Ga5, Ga4, and Ga2 are arranged in this order from upstream to downstream. In this case, the inflection point is located at the boundary of the subgroup Ga5 and Ga 4. With this arrangement, it is possible to avoid a situation where the difference in the magnitude of the amount of warping of the conveying rollers 52a becomes large in the portions where the conveying rollers 52a belonging to different groups are adjacent (for example, the portion where the conveying roller 52a belonging to the group Ga1 is adjacent to the conveying roller 52a belonging to the group Ga 3), and to reduce the disturbance in the conveyance of the object to be processed 12.

Next, the arrangement of the conveying rollers 52b belonging to the large group Gb (i.e., the small groups Gb1 to Gb3) arranged on the downstream side in the conveying direction of the heat treatment unit 20 will be further described. At a portion adjacent to the conveying rollers 52a belonging to the large group Ga (i.e., a portion adjacent to the conveying rollers 52a belonging to the subgroup Ga 2), the conveying rollers 52b belonging to the subgroup Gb1 having the smallest average value of the warpage amounts among the subgroups Gb1 to Gb3 are collectively arranged. The conveying rollers 52a belonging to the small group Ga2 in which the average value of the warpage amount is relatively small are arranged on the most downstream side among the conveying rollers 52a belonging to the large group Ga. Therefore, by arranging the conveying rollers 52b belonging to the small group Gb1 in which the average value of the warpage amounts is smallest in the portion adjacent to the conveying rollers 52a belonging to the large group Ga, it is possible to avoid an increase in the difference in the warpage amounts between the conveying

rollers

52a, 52b in the portion adjacent to the conveying rollers 52a belonging to the large group Ga and the conveying rollers 52b belonging to the large group Gb.

The conveying rollers 52b belonging to the large group Gb are arranged collectively in groups such that the average value of the warpage amounts increases from the upstream side to the downstream side of the heat treatment unit 20. Specifically, when viewed in units of groups, the groups Gb1, Gb2, and Gb3 are arranged in this order from upstream to downstream. Therefore, in the present embodiment, the conveying rollers 52a belonging to the large group Ga are arranged such that the average value of the warpage amounts becomes substantially mountain-shaped from the upstream side to the downstream side of the heat treatment section 20, while the conveying rollers 52b belonging to the large group Gb are arranged such that the warpage amounts gradually increase.

In the present embodiment, the conveying

rollers

52a and 52b having different materials are arranged in a large group unit, and the conveying roller 52a arranged on the upstream side is arranged such that the average value of the warpage amounts becomes substantially mountain-shaped from the upstream side to the downstream side of the heat treatment unit 20. Therefore, in the present embodiment, the difference in the amount of warping of the conveying

rollers

52a and 52b can be reduced even in the portion where the conveying

rollers

52a and 52b classified into different groups are adjacent, and the disturbance of the conveyance of the object 12 to be processed can be reduced.

Specific examples of the technology disclosed in the present specification have been described above in detail, but these are merely examples and do not limit the scope of the claims. The techniques recited in the claims include those obtained by modifying or changing the specific examples illustrated above. The technical elements described in the specification and 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.

Claims

1. A heat treatment furnace for heat-treating an object to be treated, comprising:

a heat treatment unit having a space for heat-treating the object to be treated; and

a plurality of conveying rollers disposed in the heat treatment section and conveying the object to be treated,

the plurality of conveying rollers disposed in the heat treatment section are classified into a plurality of groups based on the magnitude of the amount of warpage of the conveying rollers at the portion where the magnitude of warpage in the direction perpendicular to the axis is largest,

at an upstream end in the conveying direction of the heat treatment section, conveying rollers belonging to a group having a smallest average value of the warpage amounts among the plurality of groups classified are arranged.

2. The heat treatment furnace according to claim 1,

in the heat treatment unit, the conveying rollers classified into the same group are arranged collectively in a group unit so as to be arranged continuously in the conveying direction,

the plurality of conveying rollers are arranged such that an average value of the warpage amounts of the conveying rollers classified into the group becomes larger from upstream to downstream in the conveying direction when viewed in the group unit.

3. The heat treatment furnace according to claim 1,

the plurality of conveying rollers disposed in the heat treatment section are classified into a plurality of large groups based on the material of the conveying rollers, and the conveying rollers classified into the plurality of large groups are further classified into a plurality of small groups based on the magnitude of the amount of warping,

the plurality of conveying rollers are arranged continuously in the conveying direction for each of the large groups, and at least the conveying rollers belonging to the large group arranged on the upstream side are arranged so that the average value of the warpage amounts of the plurality of small groups belonging to the large group becomes substantially mountain-shaped from the upstream side to the downstream side in the conveying direction.

4. A method for manufacturing a heat treatment furnace, the heat treatment furnace comprising:

a heat treatment unit having a space for heat-treating an object to be treated; and

the method for manufacturing the heat treatment furnace comprises the following steps:

a measuring step of measuring a warp amount of a portion of each of a plurality of conveying rollers disposed in the heat treatment section, the portion having a maximum warp in a direction perpendicular to an axis of the conveying roller;

a sorting step of sorting the plurality of conveying rollers into a plurality of groups based on the magnitude of the warpage amount measured in the measuring step; and

and a setting step of setting a conveying roller belonging to a group having a smallest average value of the warpage amounts among the plurality of groups classified, at an upstream end in a conveying direction of the heat treatment section.