CN111615613B

CN111615613B - Heat treatment furnace and manufacturing method thereof

Info

Publication number: CN111615613B
Application number: CN201880085786.8A
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: 2022-03-01
Anticipated expiration: 2038-12-26
Also published as: TWI793235B; JP6997218B2; WO2019138889A1; JPWO2019138889A1; TW201930804A; CN111615613A

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. Among a plurality of conveying rollers arranged in a predetermined range of a heat treatment unit, when the conveying rollers are divided into n regions in the axial direction, the conveying rollers of the i-th type (i-1-n) in which the position where the magnitude of the warpage of the conveying rollers in the direction perpendicular to the axis is the largest is located in the i-th region (i-1-n) (i-1-n; mi ≧ 0). At least 1 of the plurality of types of conveying rollers is set to mi, and the conveying rollers are not continuously arranged by a given number or more.

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)

In such a heat treatment furnace, in order to improve productivity, a plurality of objects to be treated are placed on a conveying roller in a direction (hereinafter, also referred to as a 2 nd direction) perpendicular to and horizontal to a conveying direction (hereinafter, also referred to as a 1 st direction), and the plurality of objects to be treated are conveyed simultaneously. In this case, the plurality of objects to be processed are conveyed in the heat treatment furnace in a state of being arranged in the 2 nd direction. However, the conveying roller may be subjected to strain such as warpage during manufacturing. Therefore, the object to be processed may be obliquely conveyed due to the strain generated in the conveying rollers. When the treatment object is obliquely conveyed, there is a possibility that the conveyance of another treatment object placed in the 2 nd direction is hindered or the treatment object collides with the side wall in the heat treatment furnace. This problem is particularly significant in a heat treatment furnace having a long conveyance distance of the object to be treated.

The present specification discloses a technique for suppressing a plurality of objects to be processed placed in a horizontal direction and a direction (2 nd direction) perpendicular to a conveyance direction from being conveyed while bypassing.

(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. Among a plurality of conveying rollers arranged in a predetermined range of the heat treatment section, mi (i is 1 to n; mi is not less than 0) conveying rollers of the i-th type (i is 1 to n) are included, the position of which where the magnitude of the warpage in the direction perpendicular to the axis is the largest is located in the i-th region (i is 1 to n), when the conveying rollers are divided into n regions in the axial direction. At least 1 of the plurality of types of conveying rollers is set to mi, and the conveying rollers of the type are not continuously arranged by a given number or more.

The present inventors have conducted studies and found that, when a predetermined number of conveying rollers are continuously provided in a predetermined range of a heat treatment section, the conveying rollers having a large warpage in a predetermined region (for example, a region on the same end side), an object to be treated placed in the vicinity of the predetermined region tends to detour. In the heat treatment furnace, at least one of the i-th type of conveying rollers, which has a large warp portion in a specific region, is not continuous by a predetermined number or more, and therefore, the object to be treated placed in the vicinity of the region can be prevented from detouring.

Further, a method for manufacturing a heat treatment furnace disclosed in the present specification manufactures a heat treatment furnace including: a heat treatment unit having a space for heat-treating an object to be treated; and a plurality of conveying rollers which are arranged in the heat treatment part and convey the processed object, wherein mi (i is 1-n; mi is not less than 0) conveying rollers of the ith type (i is 1-n) are arranged in the ith area (i is 1-n) when the conveying rollers arranged in the given range of the heat treatment part are divided into n areas along the axial direction, and the positions of the conveying rollers, which have the largest warpage in the direction vertical to the axial line, are positioned in the ith area (i is 1-n). The method for manufacturing a heat treatment furnace comprises the following steps: a measuring step of measuring, for each of a plurality of conveying rollers arranged in at least a predetermined range of the heat treatment section, a magnitude of a warp of the conveying roller in a direction perpendicular to an axis line at each of a plurality of measurement positions in the axial direction of the conveying roller; and a setting step of setting the plurality of conveying rollers, the warpage of which is measured in the measuring step, in a predetermined range so that at least 1 of the plurality of types of conveying rollers is obtained by the measurement result obtained in the measuring step, the type of conveying rollers is not continuously arranged by a predetermined number or more.

In the above-described method of manufacturing a heat treatment furnace, the plurality of conveying rollers are provided so that at least 1 of the conveying rollers, which are disposed in the predetermined range of the heat treatment portion so that the position where the magnitude of the warpage of the conveying roller in the direction perpendicular to the axis is the largest, is located in the same region, is not continuously arranged by the predetermined number or more. Therefore, the object to be treated placed in the vicinity of the region can be prevented from detouring.

Drawings

Fig. 1 is a schematic diagram showing a structure of a heat treatment furnace according to an embodiment, and is a vertical cross-sectional view when the heat treatment furnace is cut along a plane parallel to a conveying direction of a workpiece.

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

Fig. 3 is a view showing a portion where the magnitude of the warpage of the conveying roller is measured and each region where the conveying roller is divided into a plurality of portions in the axial direction.

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 predetermined number may be half of the maximum number of conveying rollers against which 1 object to be treated abuts when the object is placed on the conveying rollers. According to this configuration, when the object to be processed placed in the vicinity of the region where the portion having a large warpage is located is conveyed by the conveyance rollers of which the predetermined number or more of types are not arranged consecutively, it is possible to avoid the number of portions having a large warpage from contacting with half or more of the portions where the object to be processed contacts with the conveyance rollers. Therefore, the inclination of the conveying direction of the object to be processed can be appropriately suppressed.

Examples

The heat treatment furnace 10 according to the embodiment 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. In the following description, the center side in the 2 nd direction in the case where a plurality of objects to be processed 12 are arranged in the 2 nd direction may be referred to as "inner side", and the end side (+ Y direction and — Y direction) with respect to the center in the 2 nd direction may be referred to as "outer side". 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 (inner side) 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 a suffix when it is necessary to distinguish the component, and may be described by only numerals without a suffix when it is unnecessary to distinguish the component.

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. A plurality of conveying rollers 52 are disposed in the heat treatment unit 20, the carry-in unit 34, and the carry-out unit 40. 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 conveying roller 52 is supported rotatably about its axis, and is rotated by transmission of the driving force of the driving device 60. Specifically, one end (end on the + Y direction side in fig. 2) in the axial direction of the conveying roller 52 is connected to the driving device 60, and the other end (end on the-Y direction side in fig. 2) becomes a free end. In the following description, in the axial direction of the conveying rollers 52, the end portion side (i.e., + Y direction side) where the conveying rollers 52 are connected to the driving device 60 may be referred to as "driving side", and the free end side (i.e., -Y direction side) of the conveying rollers 52 may be referred to as "driven side".

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 speed of the conveying rollers 52 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.

In the present embodiment, the plurality of conveying rollers 52 disposed in the heat treatment unit 20 are classified into a plurality of groups according to the position (position in the axial direction) at which the amount of warpage (the amount of warpage in the direction perpendicular to the axis) is maximum. Specifically, each of the conveying rollers 52 is divided into a plurality of regions in the axial direction, and a measurement point for measuring the amount of warp is set in each region. Then, the warpage amount is measured at each measurement point for each of the conveying rollers 52, and the measurement point at which the warpage amount is maximum is determined. When the measurement point at which the amount of warp is the largest is identified, the plurality of conveying rollers 52 are grouped according to the region in which the measurement point is set. For example, the transport roller 52 is axially divided into n regions Ri (i is 1 to n), and 1 measurement point Pi (i is 1 to n) is set in each region Ri. Then, the measurement point with the largest warpage amount belongs to the region R₁Set as group 1, the measurement point with the largest warpage amount belongs to the region R₂Is set as group 2, and grouping is performed in the same manner as follows. In the present embodiment, the plurality of groups grouped as exemplified above belong toThe specific set of transport rollers is referred to as

transport rollers

52a, 52 b. Therefore, the conveying

rollers

52a and 52b can be said to be conveying rollers in which, when the conveying roller 52 is divided into a plurality of regions in the axial direction, the position where the magnitude of the warpage of the conveying roller 52 in the direction perpendicular to the axis is the largest becomes a specific region among the divided regions. As a method of dividing the conveying roller 52 into a plurality of regions in the axial direction, for example, the conveying roller 52 can be divided into 3 regions, i.e., a region on the driving side, a region near the center, and a region on the driven side. The specific region can be, for example, a region on the end side of the conveying rollers 52 when the conveying rollers 52 are divided into a plurality of regions in the axial direction, that is, a region on the driving side or a region on the driven side of the conveying rollers 52.

The following describes the present embodiment more specifically with reference to fig. 3. As shown in fig. 3, in the present embodiment, 3 objects to be processed 12a to 12c are arranged and placed on the conveying rollers 52 in the 2 nd direction. Therefore, the conveying roller 52 has a region closer to the driving side than the center vicinity of the object 12a to be processed placed on the driving side as a 1 st region 54, a region between the center vicinity of the object 12a to be processed placed on the driving side and the center vicinity of the object 12c to be processed placed on the driven side as a 2 nd region 56, and a region closer to the driven side than the center vicinity of the object 12c to be processed placed on the driven side as a 3 rd region 58. In the 1 st area 54, 1 measurement point a is set, in the 2 nd area 56, 3 measurement points B, C, D are set, and in the 3 rd area 58, 1 measurement point E is set. In the present embodiment, the conveying roller 52a (i.e., the conveying roller having the largest warpage amount at the measurement point a) is the conveying roller having the largest warpage amount in the 1 st area 54 of the conveying roller 52 in the direction perpendicular to the axis line, and the conveying roller 52b (i.e., the conveying roller having the largest warpage amount at the measurement point E) is the conveying roller having the largest warpage amount in the 3 rd area 58 of the conveying roller 52 in the direction perpendicular to the axis line.

The conveying

rollers

52a and 52b are disposed so as not to be continuous by a predetermined number or more in the heat treatment unit 20. In the present embodiment, the conveying

rollers

52a and 52b are disposed so as to be not less than half the number of conveying rollers 52 that do not continuously carry 1 object to be processed 12. Here, when the number of the conveying rollers 52 on which 1 object 12 is placed varies during conveyance of the object 12, the conveying

rollers

52a and 52b are disposed so that the number of the conveying rollers 52 on which 1 object 12 is not continuously placed is half or more of the maximum number. For example, when the object 12 to be processed is placed on 6 transport rollers 52 at the maximum (that is, is always placed on 6 transport rollers 52, or is placed on 5 transport rollers 52), the heat treatment unit 20 arranges the

transport rollers

52a and 52b so that the number of the rollers is not less than 3. Alternatively, as shown in fig. 1, when the object 12 to be processed is placed on the maximum size of 3 conveying rollers 52, the conveying

rollers

52a and 52b are not continuously arranged in the heat treatment unit 20 by 2 or more. For example, the conveying

rollers

52b and 52c different from the conveying rollers 52a are disposed at positions adjacent to the conveying rollers 52a (the conveying rollers 52c indicate conveying rollers having the most warped positions other than a specific position). As an example, as shown in fig. 1, the conveying rollers 52c are disposed at positions (downstream sides) adjacent to the conveying rollers 52 a. Similarly, the conveying roller 52c is disposed at a position (upstream side) adjacent to the conveying roller 52 b. In this way, the conveying

rollers

52a and 52b are arranged so as not to be continuous by 2 or more. With this arrangement, the

objects

12a and 12c placed on the end portion side can be prevented from being detoured.

Next, a method for manufacturing the heat treatment furnace 10 will be described with reference to fig. 3. In the present embodiment, the step of measuring the magnitude of the warpage of the conveying rollers 52 and the step of arranging the conveying rollers 52 including the conveying

rollers

52a and 52b in the heat treatment unit 20 are characterized, 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: a measurement step of measuring the magnitude of the warpage of the conveying roller 52 in the direction perpendicular to the axis at a plurality of measurement positions (measurement points a to E) in the axial direction of the conveying roller 52; and an arrangement step of determining the conveying

rollers

52a, 52b based on the measurement result obtained in the measurement step, and arranging the conveying rollers 52 in the heat treatment unit 20 such that the conveying

rollers

52a, 52b are not arranged continuously by a predetermined number or more.

First, in the measurement step, the magnitude of the warpage of the conveying roller 52 in the direction perpendicular to the axis is measured at each of a plurality of measurement positions (measurement points a to E) in the axial direction of the conveying roller 52. The measurement step is performed by the following steps. 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 magnitude of the warpage of the transport roller 52 at a plurality of positions (measurement points a to E) in the axial direction is measured using a measuring instrument, for example, a dial gauge. As the plurality of axial positions 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 2 nd direction end 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 conveying roller 52 in the 2 nd direction 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 arranged and placed 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 measurement step, the magnitude of the warpage of each of the portions a to E (measurement points a to E) in the axial direction of the conveying roller 52 is measured. Specifically, a dial indicator is provided at the position a, the conveying roller 52 is rotated once around the axis, and the difference between the uppermost position of the conveying roller 52 and the state where the conveying roller 52 is not warped (hereinafter, also referred to as the magnitude of the warp) is measured. The sites B to E were also measured in the same manner as above.

When the magnitude of the warpage of each of the axial portions a to E of the plurality of conveying rollers 52 is measured, the plurality of conveying rollers 52 including the conveying

rollers

52a and 52b are set in the heat treatment unit 20 through the setting step. The arrangement step is performed by the following steps. First, it is determined which of the magnitudes of the warpage of the respective portions a to E measured in the measuring step is the largest for each of the conveying rollers 52 based on the measurement result obtained in the measuring step. Then, the conveying roller 52 having the largest magnitude of warpage is determined as the conveying roller 52a, and the conveying roller 52 having the largest magnitude of warpage is determined as the conveying roller 52b in the No. 1 area 54.

As described above, when 3 objects to be processed 12a to 12c are arranged and placed in the 2 nd direction by the conveying roller 52, the region closer to the driving side than the vicinity of the center of the object to be processed 12a placed on the driving side is set as the 1 region 54. Therefore, as shown in fig. 3, the 1 st region 54 includes only the site a among the sites a to E. Therefore, the conveying roller 52 having the largest magnitude of the warpage of the site a is determined as the conveying roller 52 a. Since the region closer to the driven side than the vicinity of the center of the object 12c placed on the driven side is defined as the 3 rd region 58, the 3 rd region 58 includes only the region E of the respective regions a to E. Therefore, the conveying roller 52 having the largest magnitude of the warp at the portion E is determined as the conveying roller 52 b. On the other hand, since the 2 nd region 56 is defined between the vicinity of the center of the object 12a placed on the driving side and the vicinity of the center of the object 12c placed on the driven side, the 2 nd region 56 includes the portion B, C, D of the respective portions a to E. Therefore, the conveying roller 52 having the largest magnitude of the warpage at any of the portions B, C, D is not determined as the conveying

rollers

52a and 52 b. In this manner, the conveying

rollers

52a, 52b are determined from the plurality of conveying rollers 52.

Next, the conveying rollers 52a are not continuously provided by a predetermined number or more, and the conveying rollers 52b are not continuously provided by a predetermined number or more. For example, when the object 12 to be heat-treated is placed on 6 transport rollers 52 at the maximum, 3 or more transport rollers 52a are not continuous, and 3 or more transport rollers 52b are not continuous. In the present embodiment, the conveying

rollers

52a and 52b are provided in discrete numbers or more, and a conventionally known method can be used for other steps of the setting step, and therefore detailed description of the other steps of the setting step is omitted.

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 carrying-in part 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 the 3 objects to be treated 12 aligned in the 2 nd direction from the carrying-in section 34 into the space 24 of the heat treatment section 20 through the opening 26. 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 object 12 after the heat treatment is conveyed to the carrying-out section 40 through the opening 28, and carried out of the carrying-out section 40.

In order to improve productivity, the objects 12 are arranged and placed in the 2 nd direction. 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 have the same shape. When the conveying

rollers

52a and 52b having large warpage are continuously arranged on the same end side (i.e., the driving side or the driven side) in the axial direction of the conveying roller 52, the

objects

12a and 12c placed outside the conveying rollers 52 are easily conveyed while being inclined. When the

objects

12a and 12c are conveyed while being inclined inward, conveyance of another object 12b (i.e., the central object 12b) placed in the 2 nd direction may be hindered. Further, when the objects to be processed 12a and 12c are conveyed while being inclined outward, there is a possibility that the objects may collide with the side wall of the furnace body of the heat treatment unit 20. In particular, since the heat treatment furnace 10 of the present embodiment has a relatively long dimension in the conveyance direction of the heat treatment unit 20, the inclination of the object 12 placed outside the conveyance rollers 52 tends to increase during conveyance of the heat treatment unit 20.

In the present embodiment, the conveying rollers 52a are not continuous by a given number or more, and the conveying rollers 52b are not continuous by a given number or more. By providing the conveying rollers 52a in a discontinuous manner by a predetermined number or more, the object 12a placed on the driving side can be prevented from being detoured. Further, by providing the conveying rollers 52b in a discontinuous manner by a predetermined number or more, the object 12c placed on the driven side can be prevented from being detoured. Therefore, it is possible to avoid the

objects

12a and 12c placed outside the conveying rollers 52 from interfering with the conveyance of the object 12b placed inside the conveying rollers 52, and to avoid the heat treatment of the heat treatment furnace 10 from being stopped. Further, the objects to be processed 12a and 12c can be prevented from contacting the side surface of the furnace body, and damage to the side wall of the furnace body can be suppressed.

In the present embodiment, the conveying roller 52 is divided into 3 regions such that the 1 st region 54 includes only the part a of the respective parts a to E, the 2 nd region 56 includes the part B, C, D of the respective parts a to E, and the 3 rd region 58 includes only the part E of the respective parts a to E, but the present invention is not limited to such a configuration. The position of the boundary between adjacent regions is not limited to the above example, and for example, the conveying roller 52 may be divided into 3 regions in the axial direction such that the 1 st region includes the portion A, B of the respective portions a to E, the 2 nd region includes only the portion C, and the 3 rd region includes the portion D, E. Further, in the present embodiment, the conveying roller 52 is divided into 3 regions in the axial direction, but the conveying roller 52 may be divided into more than 3 regions.

In the present embodiment, the conveying rollers 52 in which the portion of the conveying roller 52 having the largest magnitude of warpage is present in the region closest to the end portion side are defined as the conveying

rollers

52a and 52b, but the present invention is not limited to such a configuration. The conveying rollers may be arranged so that the portions of the conveying rollers 52 where the magnitude of the warpage is the largest are not continuous by a predetermined number or more, and any region in the case of dividing the conveying rollers 52 in the axial direction may be set as the "specific region". Even if the region other than the region closest to the end portion side is set as the "specific region", the object 12 to be processed placed in the vicinity of the "specific region" can be suppressed from detouring.

In the present embodiment, the magnitude of the warpage of the transport roller 52 at 5 positions a to E in the axial direction is measured, but the present invention is not limited to such a configuration. The number of the portions for measuring the warpage of the conveying roller 52 may be more than 5, or less than 5. In the present embodiment, the measurement location is determined based on the position of the object 12 to be processed placed in the 2 nd direction, but a location for measuring the warpage 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

52a and 52b are arranged discontinuously in all the conveying rollers 52 provided in the heat treatment unit 20, but the present invention is not limited to such a configuration. For example, the conveying

rollers

52a and 52b may be arranged discontinuously at a part (for example, a region on the conveying inlet side) of the conveying rollers 52 provided in the heat treatment unit 20.

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 given range of the heat treatment section include the i-th kind of conveying roller,

the conveying roller of the i-th type is configured such that when the conveying roller is divided into n regions in the axial direction, the position where the magnitude of the warp of the conveying roller in the direction perpendicular to the axis is the largest exists in the i-th region,

the i-th kind of carrying roller among the plurality of carrying rollers includes mi,

at least 1 kind of conveying rollers among the kinds of conveying rollers with mi being more than 2 are discontinuously arranged by more than a given number,

wherein i is 1 to n, and mi is more than or equal to 0.

2. The heat treatment furnace according to claim 1,

the predetermined number is half of the maximum number of the conveying rollers against which the object to be processed abuts when 1 object to be processed is placed on the conveying rollers.

3. 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

wherein i is 1 to n, mi is more than or equal to 0,

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

a measuring step of measuring, for each of a plurality of conveying rollers arranged in at least a predetermined range of the heat treatment section, a magnitude of a warp of the conveying roller in a direction perpendicular to an axis line at each of a plurality of measurement positions in an axial direction of the conveying roller; and

and a setting step of determining, for each of the transport rollers, a position at which the magnitude of the warpage of the transport roller in the direction perpendicular to the axis is maximum, based on the measurement result obtained in the measurement step, and setting, in the predetermined range, a plurality of transport rollers, the warpage of which is measured in the measurement step, so that a predetermined number or more of the transport rollers of the type is not sequentially arranged for at least 1 type of the transport rollers of the type whose mi is a numerical value of 2 or more.