JPWO2019138888A1 - Heat treatment furnace and its manufacturing method - Google Patents

Abstract

The heat treatment furnace heat-treats the object to be treated. The heat treatment furnace includes a heat treatment section provided with a space for heat-treating the object to be processed, and a plurality of transfer rollers arranged in the heat treatment section to convey the object to be processed. In the plurality of transport rollers installed in a predetermined range of the heat treatment section, the warp direction of the portion where the warp of the transport roller is the largest when the transport roller is viewed along the axial direction is periodically changed.

Description

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

The object to be treated may be heat-treated using a heat treatment furnace (for example, a roller hers kiln). This type of heat treatment furnace is provided with a plurality of transfer rollers, and conveys the object to be processed by rotating the transfer roller with the object to be processed placed on the transfer rollers. For example, Japanese Patent Application Laid-Open No. 2015-64189 discloses an example of a heat treatment furnace.

In this type of heat treatment furnace, in order to increase productivity, a plurality of objects to be processed are placed on the transfer roller in a direction perpendicular to and horizontal to the transfer direction (hereinafter, also referred to as the first direction) (hereinafter, also referred to as the second direction). Are placed side by side, and these multiple objects to be processed may be transported at the same time. In such a case, the plurality of objects to be processed are simultaneously carried into the heat treatment furnace in a state of being arranged in the second direction. Then, the plurality of objects to be processed are conveyed in the heat treatment furnace by the transfer roller and carried out from the heat treatment furnace. Since the plurality of objects to be processed arranged side by side in the second direction are conveyed using the same transfer roller, they should ideally be carried out from the heat treatment furnace at the same time. However, due to the bending caused by the weight of the object to be processed, the transfer speed differs depending on the position in the transfer roller on which the object to be processed is placed. As a result, there may be a problem that a plurality of objects to be processed arranged side by side in the second direction are not simultaneously carried out from the heat treatment furnace. This problem becomes remarkable especially in a heat treatment furnace in which the transport distance of the object to be processed is long.

The present specification discloses a technique for reducing the difference in transport speed of a plurality of objects to be processed that are placed side by side in a direction (second direction) that is horizontal and perpendicular to the transport direction.

The heat treatment furnace disclosed in the present specification heat-treats the object to be treated. The heat treatment furnace includes a heat treatment section provided with a space for heat-treating the object to be processed, and a plurality of transfer rollers arranged in the heat treatment section to convey the object to be processed. In the plurality of transport rollers installed in a predetermined range of the heat treatment section, the warp direction of the portion where the warp of the transport roller is the largest when the transport roller is viewed along the axial direction is periodically changed.

In the above heat treatment furnace, a plurality of objects to be processed are placed side by side in a horizontal direction and a direction perpendicular to the transport direction (second direction) by periodically changing the warp direction of the transport roller within a predetermined range of the heat treatment section. The transport speed of the can be adjusted. Therefore, it is possible to reduce the difference in transport speed caused by the position (position in the second direction) of the transport roller on which the object to be processed is placed.

Further, in the method for manufacturing a heat treatment furnace disclosed in the present specification, a heat treatment furnace including a heat treatment section provided with a space for heat-treating the object to be processed and a plurality of transfer rollers arranged in the heat treatment section to convey the object to be processed. To manufacture. In the method for manufacturing the heat treatment furnace, for each of a plurality of transport rollers installed in a predetermined range of the heat treatment section, the warp of the portion where the warp of the transport roller is the largest when the transport roller is viewed along the axial direction is obtained. A measurement step of measuring the direction and an installation step of installing a transport roller so that the measured warp direction changes periodically for a predetermined range of the heat treatment unit are provided.

In the above-mentioned method for manufacturing a heat treatment furnace, a transfer roller is installed so that the measured warp direction changes periodically in a predetermined range of the heat treatment section. Therefore, it is possible to adjust the transport speed of a plurality of objects to be processed arranged side by side in the second direction, and reduce the difference in transport speed caused by the position of the transfer roller on which the objects to be processed are placed. be able to.

It is a figure which shows the schematic structure of the heat treatment furnace which concerns on Example, and is the vertical sectional view when the heat treatment furnace is cut in the plane parallel to the transport direction of the object to be processed. FIG. 2 is a cross-sectional view taken along the line II-II of FIG. The figure which shows the part which measures the warp magnitude and the warp direction of a transport roller. It is a figure which shows the state which adjusted the warp direction of a transfer roller schematically, (a) shows the state which the warp direction of the adjacent transfer roller is shifted by 90 °, (b) is the state which the warp direction of the adjacent transfer roller is shifted by 90 ° The state where the direction is shifted by 180 ° is shown. It is a figure for demonstrating the transfer of the object to be processed when the bending of the transfer roller is large, (a) shows the placement state of the object to be processed to be placed in the center of the transfer roller, and (b). ) Indicates the mounting state of the object to be mounted on the end of the transport roller. It is a figure which shows typically the transport roller in a state where the warp direction of the adjacent transport roller is shifted by 90 ° when the deflection of the transport roller is large, and the object to be placed on the end of the transport roller. (A) to (d) show a state in which the transport roller is rotated by 90 °. It is a figure which shows typically the transport roller in a state where the warp direction of an adjacent transport roller is shifted by 180 ° when the deflection of the transport roller is large, and the object to be placed on the end of the transport roller. (A) to (d) show a state in which the transport roller is rotated by 90 °.

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

(Characteristic 1) In the heat treatment furnace disclosed in the present specification, a plurality of transfer rollers installed in a predetermined range of the heat treatment section may be configured in one cycle by a predetermined number of transfer rollers. The warp direction of each transport roller constituting one cycle may be deviated by a predetermined angle with respect to the warp direction of the transport roller adjacent to the transport roller. According to such a configuration, it is possible to suitably adjust the transport speed of a plurality of objects to be processed that are placed side by side in a direction (second direction) that is horizontal and perpendicular to the transport direction. In particular, when the transport speed of the object to be processed placed on the end side of the transfer roller is faster than the object to be processed placed near the center, a plurality of objects to be processed arranged side by side in the second direction. The difference in transport speed can be reduced.

(Feature 2) The heat treatment furnace disclosed in the present specification may further include a drive device capable of simultaneously driving a plurality of transfer rollers installed in a predetermined range. The drive device may drive a plurality of transfer rollers installed in a predetermined range while maintaining a state in which the warp direction of the transfer rollers deviates from the warp direction of the adjacent transfer rollers by a predetermined angle. According to such a configuration, by simultaneously driving a plurality of transport rollers installed in a predetermined range by a driving device, the warp angles of the plurality of transport rollers installed in a predetermined range are predetermined with the warp angles of adjacent transport rollers. It is possible to maintain the state where the angle is deviated. Therefore, it is possible to maintain a state in which the transport speeds of a plurality of objects to be processed arranged side by side in the second direction are adjusted.

(Feature 3) In the heat treatment furnace disclosed in the present specification, the predetermined angle may be 90 degrees. According to such a configuration, the transport speed of a plurality of objects to be transported arranged side by side in the second direction can be suitably adjusted according to the amount of deflection of the transport roller. In particular, when the amount of deflection of the transport roller when the object to be processed is placed on the transfer roller is small, the difference in the transfer speeds of a plurality of objects to be processed arranged side by side in the second direction can be reduced.

(Feature 4) In the heat treatment furnace disclosed in the present specification, the predetermined angle may be 180 degrees. According to such a configuration, the transport speed of a plurality of objects to be transported arranged side by side in the second direction can be suitably adjusted according to the amount of deflection of the transport roller. In particular, when the amount of deflection of the transport roller when the object to be processed is placed on the transfer roller is large, it is possible to reduce the difference in the transfer speeds of the plurality of objects to be processed arranged side by side in the second direction.

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

Examples of the object 12 to be treated include a laminate in which a ceramic dielectric (base material) and an electrode are laminated, a positive electrode material and a negative electrode material of a lithium ion battery, and the like. When the ceramic laminates are heat-treated using the heat treatment furnace 10, they can be placed on a flat plate-shaped setter and conveyed in the furnace. Further, when the positive electrode material and the negative electrode material of the lithium ion battery are heat-treated using the heat treatment furnace 10, they can be housed in a box-shaped saggar and transported in the furnace. In the heat treatment furnace 10 of the present embodiment, a plurality of setters and sags can be placed and transported in a state of being arranged in the transport direction on the transport roller 52 (described later). Hereinafter, in the present embodiment, the entire combination of the substance to be heat-treated, the setter on which the substance to be heat-treated is placed, and the container containing the heat-treated substance is referred to as "object 12 to be treated". Further, in the following description, the direction in which the object to be processed 12 is conveyed (the direction perpendicular to the YZ plane in FIG. 1) may be referred to as a "transportation direction" or a "first direction", and is horizontal and perpendicular to the first direction. (Direction perpendicular to the XZ plane in FIG. 1) may be referred to as a "second direction".

The heat treatment section 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 the front end surface of the outer wall 22 (the end surface on the −X side in FIG. 1), and an opening 28 is formed in the rear end surface (the 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 section 20 by the transfer device 50, and is conveyed from the opening 28 to the outside of the heat treatment section 20. That is, the opening 26 is used as a carry-in port of the heat treatment section 20, and the opening 28 is used as a carry-out port of the heat treatment section 20.

A plurality of transfer rollers 52 and a plurality of heaters 30 and 32 are arranged in the space 24. The heaters 30 are arranged at positions above the transport roller 52 at equal intervals in the transport direction, and the heaters 32 are arranged at positions below the transport roller 52 at equal intervals in the transport direction. The heat generated by the heaters 30 and 32 heats the space 24. In this embodiment, the heaters 30 and 32 are arranged at equal intervals in the transport direction, but the configuration is not limited to this. 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. Further, in this embodiment, the heaters 30 and 32 are arranged in the space 24, but the present invention is not limited to such a configuration. It suffices if the space 24 can be heated, and for example, a gas burner or the like may be installed in the space 24.

As shown in FIG. 2, in the heat treatment unit 20, a plurality of objects 12 to be processed are conveyed side by side in the second direction. In this embodiment, in the heat treatment section 20 (that is, the entire heat treatment furnace 10), the three objects to be processed 12 are transported side by side in the second direction. Therefore, in this embodiment, the dimension of the heat treatment section 20 in the second direction is larger than the dimension in which three objects 12 to be processed are arranged in the second direction, but the dimension of the heat treatment section 20 in the second direction is larger. , Not particularly limited. The size of the heat treatment unit 20 in the second direction may be such that more than three objects 12 to be processed can be arranged and conveyed in the second direction. Further, the dimension of the heat treatment unit 20 in the transport direction is relatively large, about 100 m, but the dimension of the heat treatment unit 20 in the transport direction is not particularly limited. For example, the size of the heat treatment unit 20 in the transport direction may be smaller than 100 m, 30 m to 100 m, or larger than 100 m. In the following description, when a plurality of objects 12 to be processed are lined up in the second direction, the center side in the second direction is referred to as "inside", and the end side (+ Y direction and) with respect to the center in the second direction. -Y direction) may be referred to as "outside". The object to be processed 12 is continuously carried into the heat treatment unit 20 at predetermined intervals. Therefore, the objects to be processed 12 are arranged side by side not only in the second direction but also in the transport direction.

As shown in FIG. 2, in this embodiment, of the three objects to be processed 12 placed side by side in the second direction, the object to be processed 12a is placed on the + Y direction side of the second direction. , The object placed in the center (inside) of the second direction is referred to as the object to be processed 12b, and the object placed on the −Y direction side in the second direction is distinguished as the object to be processed 12c. Hereinafter, for other components as well, when it is necessary to distinguish the components, the alphabet of the characters is used, and when it is not necessary to distinguish the components, the alphabet of the characters is omitted. It may be described in numbers.

The carry-in unit 34 is located on the upstream side of the heat treatment unit 20 (that is, on the upstream side in the transport direction, and in FIG. 1, in the −X direction of the heat treatment unit 20). The carry-in unit 34 receives the object to be processed 12 carried from the outside of the heat treatment furnace 10 and carries the received object 12 into the space 24 of the heat treatment unit 20. A transfer roller 52 is installed in the carry-in unit 34, and the object 12 to be processed carried from the outside of the heat treatment furnace 10 is conveyed by the transfer roller 52.

The carry-out section 40 is located on the downstream side of the heat treatment section 20 (that is, on the downstream side in the transport direction, and in FIG. 1, in the + X direction of the heat treatment section 20). The carry-out unit 40 carries out the object to be processed 12 from the space 24 of the heat treatment unit 20, and delivers the carried-out object 12 to the outside of the heat treatment furnace 10. A transport roller 52 is installed in the carry-out portion 40, and the object 12 to be processed is transported to the outside of the space 24 by the transport roller 52.

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

The transport roller 52 has a cylindrical shape, and its axis extends in a direction orthogonal to the transport direction. The plurality of transfer rollers 52 all have the same diameter, and are arranged at equal intervals at a constant pitch in the transfer direction. The diameter of the transport roller installed in the heat treatment section 20 may be different from the diameter of the transport roller installed in the carry-in section 34 and the carry-out section 40. Further, the transport rollers 52 installed in the heat treatment section 20 may be arranged at a pitch different from that of the transport rollers 52 installed in the carry-in section 34 and the carry-out section 40. The transport roller 52 is rotatably supported around its axis, and rotates by transmitting the driving force of the driving device 60. A plurality of transfer rollers 52 are arranged in the heat treatment section 20, the carry-in section 34, and the carry-out section 40. The axial dimension of the transport roller 52 is larger than the second direction dimension of the heat treatment section 20 (see FIG. 2).

The plurality of transport rollers 52 arranged in the heat treatment unit 20 are located on a plurality of axially portion of the transport rollers 52 when the transport rollers 52 are viewed along the axial direction (that is, the second direction or the Y direction). It is installed by adjusting the warp direction of the portion where the warp is the largest (hereinafter, also referred to as the warp direction of the transport roller 52). As the plurality of parts in the axial direction of the transport roller 52, for example, when a portion near the center of the transport roller 52 and a plurality of objects 12 to be processed are placed side by side in the second direction on the transport roller 52, each portion to be processed is to be processed. A portion near the portion where the end portion of the object 12 in the second direction and the transport roller 52 come into contact with each other can be adopted. In this embodiment, as shown in FIG. 3, since the three objects to be processed 12a to 12c are placed side by side in the second direction on the transport roller 52, the end side (+ Y direction side) end of the object to be processed 12a is placed. The vicinity of the portion is designated as the portion A, the vicinity of the boundary between the object to be processed 12a and the object to be processed 12b is designated as the portion B, the vicinity of the axial center of the transport roller 52 is designated as the portion C, and the vicinity of the boundary between the object to be processed 12b and the object to be processed 12c Is designated as a portion D, and the vicinity of the end portion on the end portion side (−Y direction side) of the object to be processed 12c is designated as a portion E. Therefore, in this embodiment, the warp direction of the portion having the largest warp is defined as the warp direction of the transport roller 52 among the five portions A to E in the axial direction of the transport roller 52. In this embodiment, the warp direction of the transport roller 52 is set from the warp direction of the five parts A to E in the axial direction of the transport roller 52, but the configuration is not limited to this. The warp direction of the transport roller 52 may be set based on the warp direction of more than five parts in the axial direction of the transport roller 52, or may be set based on the warp direction of less than five parts. .. Further, a plurality of parts in the axial direction may be set regardless of the position of the object to be processed 12 placed on the transport roller 52.

In this embodiment, the warp direction of the transport roller 52 arranged in the heat treatment unit 20 is adjusted in a different manner based on the amount of deflection of the transport roller 52 that occurs when the object 12 to be processed is placed on the transport roller 52. .. Specifically, the transport roller 52 is installed so that the warp direction changes periodically. That is, the transfer rollers 52 are arranged in a state of being displaced by a predetermined angle with respect to the warp direction of the adjacent transfer rollers 52. Specifically, when the amount of deflection of the transfer roller 52 is large, the adjacent transfer rollers 52 are arranged so as to be displaced by 180 ° in the warp direction. When the amount of deflection of the transfer roller 52 is relatively small, the adjacent transfer rollers 52 are arranged so as to be offset by 90 ° in the warp direction. By arranging in this way, it is possible to reduce the difference in the transport speeds of the plurality of objects 12a to 12c to be processed arranged side by side in the second direction in the heat treatment section 20.

The drive device 60 (see FIG. 1) is a drive device (for example, a motor) that drives the transfer roller 52. The drive device 60 is connected to the transfer roller 52 via a power transmission mechanism. When the driving force of the drive device 60 is transmitted to the transfer roller 52 via the power transmission mechanism, the transfer roller 52 rotates. As the power transmission mechanism, a known one can be used, and for example, a mechanism using a sprocket and a chain is used. The drive device 60 drives each of the transfer rollers 52 so that the transfer rollers 52 rotate at substantially the same speed. The drive device 60 is controlled by the control device 62.

The plurality of transfer rollers 52 rotate by transmitting the driving force of the driving device 60. In this embodiment, the plurality of transfer rollers 52 connected to the same drive device 60 rotate at the same time and at the same speed. Therefore, the plurality of transport rollers 52 whose warp directions of the transport rollers 52 are adjusted as described above rotate while maintaining the adjusted warp directions. Since the transfer roller 52 installed in the heat treatment unit 20 preferably rotates at the same time and at the same speed, it is preferable that the transfer roller 52 is connected to one drive device 60. However, if the distance in the transport direction of the heat treatment section 20 is relatively long as in the heat treatment furnace 10 of the present embodiment, one drive device 60 can rotate all the transfer rollers 52 installed in the heat treatment section 20. difficult. In such a case, a plurality of drive devices 60 that generate the same driving force are installed in each of the connected transfer rollers 52, and all the transfer rollers 52 installed in the heat treatment unit 20 are driven by the same driving force. As described above, the transport roller 52 installed in the heat treatment unit 20 is divided and connected to the plurality of drive devices 60. As a result, all the transport rollers 52 installed in the heat treatment unit 20 can be rotated at the same driving force and the same speed. At this time, the transfer rollers 52 connected to the different drive devices 60 may be rotated at different timings, and between the transfer rollers 52 connected to the different drive devices 60 (that is, between the transfer rollers 52 at the boundary). It may not be possible to maintain the adjusted warpage direction. Even in such a case, since the transport roller 52 connected to the same drive device 60 can maintain the adjusted warp direction, a plurality of objects to be processed 12a to be placed side by side in the second direction. The difference in transport speed in the heat treatment section 20 of 12c can be reduced. The transfer roller 52 installed in the carry-in unit 34 and the carry-out unit 40 may be connected to a drive device that generates a different driving force from the drive device 60 that drives the transfer roller 52 installed in the heat treatment unit 20. , It may be configured to rotate at a speed different from that of the transport roller 52 installed in the heat treatment unit 20.

Next, a method for manufacturing the heat treatment furnace 10 will be described with reference to FIGS. 3 and 4. In this embodiment, the step of measuring the warp direction of the transport roller 52 and the step of arranging the transport roller 52 in the heat treatment unit 20 are characteristic, and conventionally known steps can be used for the other steps. Therefore, in the following, only the characteristic portion of this embodiment will be described, and the description of other steps will be omitted.

The method for manufacturing the heat treatment furnace 10 of this embodiment includes a measurement step of measuring the warp direction of the portion where the warp of the transport roller 52 is the largest when the transport roller 52 is viewed along the axial direction, and the measured warp direction. It is provided with an installation process for installing the transport roller 52 so as to change periodically.

First, by the measuring step, the warp direction of the portion where the warp of the transport roller 52 is the largest is measured for each of the plurality of transport rollers 52. The measurement step is carried out in the following procedure. First, both ends of the transport roller 52 are rotatably supported. For example, both ends of the transport roller 52 are supported by using two V-shaped blocks.

Next, the magnitude of the warp of each portion A to E in the axial direction of the transport roller 52 is measured using a measuring device, for example, a dial gauge. Specifically, a dial gauge is installed at the portion A, the transport roller 52 is rotated once around the axis, and the difference between when the transport roller 52 is located at the uppermost position and when the transport roller 52 is not warped (hereinafter, warpage). (Also called the size of) is measured. The same measurement is performed for the parts B to E. After measuring the amount of warpage of each part A to E, the measurement results of the five parts A to E are compared to determine the part having the largest amount of warpage. Then, a mark 54 (see FIG. 4) indicating the warp direction of the portion having the largest warp is attached to the end face in the axial direction of the transport roller 52. Similarly, the warp directions of all the transport rollers 52 installed in the heat treatment section 20 are measured, and marks 54 indicating the warp directions of the transport rollers 52 are attached to the axial end faces of the transport rollers 52.

The transport roller 52 with the mark 54 is installed in the heat treatment unit 20 by the installation process. When the transfer roller 52 is installed in the heat treatment furnace 10, the transfer roller 52 is installed while adjusting the warp direction of each transfer roller 52 based on the mark 54 attached to each transfer roller 52 in the above measurement step. The present embodiment is characterized in that each transport roller 52 is installed while adjusting the warp direction, and a conventionally known method can be used for other procedures in the installation process. The detailed description of the procedure of is omitted.

As described above, the transport roller 52 installed in the heat treatment unit 20 is installed based on the warp direction, but the installation mode is the deflection of the transport roller 52 that occurs when the object 12 to be processed is placed on the transport roller 52. It depends on the amount. Therefore, the warp direction of the transport roller 52 adjusted when each transport roller 52 is installed differs depending on the weight of the object to be heat-treated 12. Specifically, when the amount of bending is large, each transport roller 52 is installed by shifting the warp direction of the transport rollers 52 by 180 ° from the warp direction of the adjacent transport rollers 52 (FIG. 4B). When the amount of bending is small, each transport roller 52 is installed by shifting the warp direction of the transport rollers 52 by 90 ° from the warp direction of the adjacent transport rollers 52 (FIG. 4A).

Next, the operation of the heat treatment furnace 10 when the object 12 to be treated is heat-treated will be described. In order to heat-treat the object 12 to be processed, first, the heaters 30 and 32 are operated to set the ambient temperature of the space 24 to a set temperature. Next, the three objects to be processed 12 are moved from the outside of the heat treatment furnace 10 onto the transfer rollers 52 installed in the carry-in section 34, respectively. At this time, three objects 12 to be processed are placed side by side in the second direction. Next, the drive device 60 is operated to convey the three objects 12 to be processed arranged in the second direction from the carry-in portion 34 through the opening 26 into the space 24 of the heat treatment portion 20. The object 12 to be transported in the space 24 is transported in the space 24 from the opening 26 to the opening 28. As a result, the object 12 to be treated is heat-treated. Then, the heat-treated object 12 is conveyed to the carry-out section 40 through the opening 28, and is carried out from the carry-out section 40.

The object 12 to be processed is transported from the carry-in section 34 through the heat treatment section 20 to the carry-out section 40 in a state where a plurality (three in this embodiment) are arranged side by side in the second direction. However, even if the plurality of objects 12 to be processed are carried in at the inlet of the heat treatment unit 20 in a state of being aligned in the transport direction, the transfer speeds of the plurality of objects 12 to be processed are deviated while being transported by the heat treatment unit 20. When it is generated and carried out from the heat treatment unit 20, the plurality of objects 12 to be processed are in a state of being displaced in the transport direction. This deviation is caused by distortion such as warpage that occurs during the manufacture of the transfer roller 52, and bending that occurs in the transfer roller 52 when the object to be processed 12 is placed on the transfer roller 52 due to the weight of the object to be processed 12. Empirically, in particular, when the "deflection" of the transfer roller 52 is larger than the "warp" of the transfer roller 52, the transfer speed of the object to be processed 12 placed on the outside (end side) of the transfer roller 52 is transfer. It is known that the transfer speed of the object to be processed 12 placed on the inside (center) of the roller 52 is likely to be higher. This is thought to occur for the following reasons.

Since the transfer roller 52 is warped or distorted during manufacturing, all the transfer rollers 52 installed in the heat treatment furnace 10 cannot have exactly the same shape. When the "deflection" of the transfer roller 52 is larger than the "warp" of the transfer roller 52, the effect of the "warp" is canceled by the "deflection" of the transfer roller 52, but due to the influence of the variation in the diameter dimension of the transfer roller 52, The transport speed of the object to be processed 12 placed on the outside (end side) of the transfer roller 52 tends to be faster than the transfer speed of the object to be processed 12 placed on the inside (center) of the transfer roller 52.

This will be described with reference to FIG. FIG. 5 schematically shows an object 12 to be processed, which is placed on the six transfer rollers 52. The six transfer rollers 52 are arranged in the order of transfer rollers 52a to 52f from upstream to downstream (in the + X direction) in the transfer direction. Further, in the six transport rollers 52a to 52f, the diameter dimensions of the transport rollers 52a, 52c and 52e are large, and the diameter dimensions of the transport rollers 52b, 52d and 52f are small. In FIG. 5, in order to clarify the difference in diameter, the difference in diameter between the transport rollers 52a, 52c, 52e and the transport rollers 52b, 52d, 52f is emphasized.

Here, since the transport roller 52 is supported at both ends, its "deflection" is large at the center and small at the ends. If the "deflection" of the transfer roller 52 is small, the object to be processed 12 will come into contact with only the transfer roller 52 having a large diameter. On the other hand, if the "deflection" of the transfer roller 52 is large, the object 12 to be processed greatly bends the transfer roller 52 having a large diameter, and as a result, comes into contact with the transfer roller 52 having a small diameter.

As shown in FIG. 5A, since the deflection of the transfer rollers 52a, 52c, 52e is large near the center of the transfer roller 52, the object to be processed 12b is in contact with the other transfer rollers 52b, 52d, 52f. Become. That is, the object to be processed 12b comes into contact with all the transport rollers 52a to 52f. On the other hand, as shown in FIG. 5B, since the deflection of the transfer rollers 52a, 52c, 52e is small at the end of the transfer roller 52, the objects to be processed 12a, 12c do not come into contact with the transfer rollers 52b, 52d, 52f. A condition arises. Therefore, at the end of the transfer roller 52, the objects to be processed 12a, 12c are conveyed only by the transfer rollers 52a, 52c, 52e having a large turning radius, and as a result, the transfer speed of the objects to be processed 12a, 12c is high. Become. On the other hand, in the state shown in FIG. 5A, since the transfer rollers 52a, 52c, and 52e are greatly bent, the object to be processed 12b comes into contact with all the transfer rollers 52a to 52f, and the diameter dimensions of the transfer rollers 52a to 52f are large. Reduce the impact. As a result, the transport speed of the object to be processed 12 placed inside the transport roller 52 is slower than the transport speed of the object 12 to be processed placed on the outside (end side).

In this way, the transport speed of the object 12 to be processed changes depending on the warp, deflection, and variation in diameter of the transport roller 52. Therefore, the plurality of objects to be processed 12 arranged in the second direction may be displaced in the conveying direction while the objects to be processed 12 are conveyed through the heat treatment unit 20. In particular, as described above, since the heat treatment furnace 10 of this embodiment has a relatively long dimension in the transport direction of the heat treatment section 20, the plurality of objects 12 to be transported side by side in the second direction are likely to shift in the transport direction. If the plurality of objects 12 to be processed are not aligned in the second direction in the carry-out section 40, it becomes difficult to carry the plurality of objects 12 to be processed to the outside of the heat treatment furnace 10. Therefore, the warp direction of the transport roller 52 is adjusted so that the difference in transport speed between the heat-treated portions 20 of the plurality of objects 12a to 12c placed side by side in the second direction becomes small. The adjustment of the warp direction of the transport roller 52 installed in the heat treatment unit 20 will be described in more detail below.

As described above, when the "deflection" of the transfer roller 52 is larger than the "warp" of the transfer roller 52, the transfer speed of the objects to be processed 12a and 12c placed on the outside of the transfer roller 52 is the inside of the transfer roller 52. It tends to be faster than the transport speed of the object to be processed 12b placed on the surface. This is because, as already described with reference to FIG. 5, the object to be processed 12b placed inside the transport roller 52 is affected by the warp of the transport roller 52 and the influence of the variation in the diameter dimension of the transport roller 52. On the other hand, it is considered that the objects to be processed 12a and 12c placed on the outside of the transport roller 52 are easily affected by the variation in the diameter dimension of the transport roller 52.

When the weight of the object to be processed 12 is heavy, the deflection of the transfer roller 52 becomes large near the center of the transfer roller 52, so that the object to be processed 12b placed inside the transfer roller 52 has six transfer rollers 52. Contact all of. Therefore, the object to be processed 12b is always in the state shown in FIG. 5A regardless of the warp direction of the transport roller 52. Therefore, the object to be processed 12b is less susceptible to the influence of the warp of the transfer roller 52 and the variation in the diameter dimension of the transfer roller 52, and it is difficult to adjust the transfer speed of the object to be processed 12b. Therefore, in order to reduce the difference between the transfer speed of the object to be processed 12b placed inside the transfer roller 52 and the transfer speed of the objects 12a and 12c to be processed placed outside the transfer roller 52, it is necessary to reduce the difference. It is necessary to adjust the transport speed of the objects to be processed 12a and 12c placed on the outside of the transport roller 52. That is, it is necessary to suppress the increase in the transport speed of the objects to be processed 12a and 12c.

Since the deflection of the transport roller 52 is small at the end of the transport roller 52, the objects 12a and 12c to be processed tend not to come into contact with all of the six transport rollers 52. For example, as shown in FIG. 6, the transport roller 52 located at the uppermost position due to the warp (the transport roller 52 shown by the virtual line in FIG. 6) is pressed downward by the deflection, but the transport roller 52 located at the lowermost position due to the warp. The transport roller 52 hardly bends to the position of. Therefore, it is difficult for the object to be processed 12 to come into contact with the transport roller 52 located at the lowermost position due to the warp. However, as shown in FIGS. 6A to 6D, when the adjacent transport rollers 52 are arranged with the warp directions shifted by 90 °, the four transport rollers 52 are rotated by 90 °. In any case, the objects to be processed 12a and 12c come into contact with a relatively large number of the transport rollers 52 (4 or 5 transport rollers 52 in the example of FIG. 6) among the 6 transport rollers 52. Therefore, when the object 12 to be processed comes into contact with a relatively large number of transport rollers 52, the influence of the variation in the diameter dimension of the transport rollers 52 becomes strong. As a result, when the warp directions of the adjacent transport rollers 52 are shifted by 90 °, the transport speeds of the objects to be processed 12a and 12c placed on the outside of the transport rollers 52 tend to increase.

On the other hand, as shown in FIGS. 7 (a) to 7 (d), when the warp directions of the adjacent transport rollers 52 are shifted by 180 °, the four transport rollers 52 are rotated by 90 °. In half of the cases (in the case of FIGS. 7 (a) and 7 (c)), the objects to be processed 12a and 12c have a relatively small number of transfer rollers 52 (FIG. 7) out of the six transfer rollers 52. Then, it comes into contact with the three transport rollers 52). Therefore, in FIGS. 7 (a) and 7 (c), the number of transport rollers 52 that the objects to be processed 12a and 12c come into contact with is relatively small, and the transport mode changes. According to the experiment of the present inventor, it is suppressed that the objects to be processed 12a and 12c placed on the outside of the transport roller 52 are transported faster in the case shown in FIG. 7 than in the case shown in FIG. It has been confirmed that the difference between the transfer speed of the object to be processed 12 placed inside the transfer roller 52 and the transfer speed of the object to be processed 12 placed outside the transfer roller 52 can be reduced.

Further, if the warp directions of the adjacent transport rollers 52 are matched, it becomes easy to contact all six transport rollers 52. Therefore, as in the case shown in FIG. 6, it is easily affected by the variation in the diameter dimension of the transport roller 52, and the transport speed of the objects to be processed 12a and 12c placed on the outside of the transport roller 52 tends to be high. Become.

For the above reasons, when the "deflection" of the transfer roller 52 is larger than the "warp" of the transfer roller 52 and the amount of deflection of the transfer roller 52 is large, the warp direction of the adjacent transfer rollers 52 is shifted by 180 °. It is considered that the difference in transport speed between the plurality of objects to be processed 12a to 12c placed side by side in the second direction can be reduced by arranging them.

Further, the adjustment of the warp direction of the transport roller 52 when the "deflection" of the transport roller 52 is larger than the "warp" of the transport roller 52 but the weight of the object to be processed 12 is relatively light will be described. When the weight of the object to be processed 12 is relatively light, the amount of deflection of the transfer roller 52 is small, so that the object to be processed 12b arranged at the center of the transfer roller 52 has a relatively large number of transfer rollers 52. Although they come into contact with each other, the objects to be processed 12a and 12c arranged at the ends of the transport rollers 52 come into contact with a relatively small number of transport rollers 52. Therefore, the object 12b to be processed, which is arranged in the center of the transport roller 52, is less affected by both the “warp” and the “variation in diameter dimension” of the transport roller 52, and it becomes difficult to adjust the transport speed. On the other hand, the objects to be processed 12a and 12c arranged on the end side of the transport roller 52 are strongly affected by the variation in diameter and dimension. Therefore, when the warp direction of the transfer roller 52 is not adjusted, the transfer speed of the objects to be processed 12a and 12c placed on the outside of the transfer rollers 52 is the transfer speed of the objects to be processed 12b placed on the inside of the transfer rollers 52. It tends to be faster than the transport speed. Therefore, in order to reduce the difference in the transport speeds of the objects to be processed 12a to 12c, it is necessary to increase the transport speed of the objects to be processed 12b.

For example, when the warp directions of the adjacent transport rollers 52 are shifted by 90 ° and the transport rollers 52 are positioned at the lowermost position due to the warp, the transport rollers 52 are less likely to come into contact with the central object to be processed 12b. That is, the state is similar to that shown in FIG. 6, and the frequency of increase in the radius of gyration of the transfer roller 52 increases as compared with the case where all the transfer rollers 52 come into contact with the object 12 to be processed. Therefore, if the warp directions of the adjacent transport rollers 52 are shifted by 90 °, the transport speed of the object to be processed 12b tends to increase. Similarly, when the warp directions of the adjacent transport rollers 52 are shifted by 180 °, the state similar to that shown in FIG. 7 is obtained. Therefore, it is suppressed that the object to be processed 12b is conveyed faster than the state shown in FIG.

When the warp directions of the adjacent transport rollers 52 are matched, the warp directions of the adjacent transport rollers 52 are affected by the variation in the diameter dimension of the transport rollers 52 as compared with the case where the warp directions are shifted by 180 °. Therefore, the transport speed of the object to be processed 12b tends to be high. However, since the transport rollers 52 are bent, the object to be processed 12b is more likely to come into contact with a larger number of transport rollers 52 as compared with the case where the transport rollers 52 are arranged with the warp directions shifted by 90 °. Therefore, the object to be processed 12b placed inside the transport roller 52 is arranged with the warp directions of the adjacent transport rollers 52 shifted by 90 ° as compared with the case where the warp directions of the adjacent transport rollers 52 are matched. The transport speed of the is likely to increase.

For the above reasons, when the "deflection" of the transfer roller 52 is larger than the "warp" of the transfer roller 52 and the amount of deflection of the transfer roller 52 is small, the warp direction of the adjacent transfer rollers 52 is 90 °. It is considered that the difference in the transport speeds of the plurality of objects to be processed 12a to 12c placed side by side in the second direction can be reduced by arranging them so as to be staggered.

In this embodiment, the warp direction of the transport roller 52 is adjusted based on the amount of deflection of the transport roller 52 that occurs when the object 12 to be processed is placed on the transport roller 52. As a result, the difference between the transfer speed of the object to be processed 12b placed inside the transfer roller 52 and the transfer speed of the objects 12a and 12c to be processed placed outside the transfer roller 52 can be reduced. Therefore, it is possible to reduce the deviation in the transport direction when the plurality of objects 12 to be processed, which are carried in the heat treatment furnace 10 side by side in the second direction, are carried out to the carry-out portion 40, and can be easily carried out from the heat treatment furnace 10. Can be done.

In this embodiment, when the "deflection" of the transfer roller 52 is larger than the "warp" of the transfer roller 52, the adjacent transfer rollers 52 are arranged by shifting the warp direction, but the configuration is limited to this. Not done. It suffices if it is possible to prevent the transfer speed of the objects to be processed 12a and 12c placed on the outside of the transfer roller 52 from becoming faster than the transfer speed of the objects to be processed 12b placed on the inside of the transfer rollers 52. It suffices that the warp direction of the transport roller 52 changes periodically. For example, the warp direction may be periodically changed by using two adjacent transport rollers 52 as one unit. That is, the warpage directions of the two adjacent transport rollers 52 are the same, and the warp directions of the two transport rollers 52 and the adjacent two transport rollers 52 are 90 ° or 180. It may be off by °. Further, when the number of transport rollers 52 for mounting one object 12 to be processed is large, the warp directions of three or more adjacent transport rollers 52 are the same, and the warp directions are the same. The warp direction of the three or more transfer rollers 52 and the adjacent three or more transfer rollers 52 may be deviated by 90 ° or 180 °.

Further, in the present embodiment, when the "deflection" of the transfer roller 52 is larger than the "warp" of the transfer roller 52, the adjacent transfer rollers 52 are arranged so as to be offset by 90 ° or 180 °. Not limited to. It suffices if it is possible to prevent the transfer speed of the objects to be processed 12a and 12c placed on the outside of the transfer roller 52 from becoming faster than the transfer speed of the objects to be processed 12b placed on the inside of the transfer rollers 52, and they are adjacent to each other. The angle at which the warp direction of the transport roller 52 is shifted is not limited to the above embodiment. For example, the warp direction of the adjacent transfer rollers 52 may be shifted by 45 °, 72 °, or 120 °.

Further, in this embodiment, the warp directions of all the transport rollers 52 installed in the heat treatment unit 20 are adjusted, but the configuration is not limited to this. The warp direction of the transport roller 52 may be adjusted so that the difference in transport speed between the heat-treated portions 20 of the plurality of objects 12 placed side by side in the second direction becomes small. For example, the heat-treated portion 20 may be used. The warp direction of the transport roller 52 may be adjusted in a part of the transport rollers 52 to be installed.

Although specific examples of the techniques disclosed in the present specification have been described in detail above, these are merely examples and do not limit the scope of claims. The techniques described in the claims include various modifications and modifications of the specific examples illustrated above. In addition, the technical elements described in the present specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing.

Claims (6)

A heat treatment furnace that heat-treats an object to be processed.
A heat treatment unit provided with a space for heat-treating the object to be treated,
It is provided with a plurality of transport rollers arranged in the heat treatment section and transport the object to be processed.
In the plurality of transport rollers installed in the predetermined range of the heat treatment section, the warp direction of the portion where the warp of the transport roller is the largest when the transport roller is viewed along the axial direction is periodically changed. , Heat treatment furnace. The plurality of transfer rollers installed in the predetermined range of the heat treatment section are composed of a predetermined number of transfer rollers for one cycle.
The heat treatment furnace according to claim 1, wherein the warping direction of each transport roller constituting the one cycle is deviated by a predetermined angle with respect to the warp direction of the transport roller adjacent to the transport roller. Further, it is further provided with a drive device capable of simultaneously driving a plurality of transfer rollers installed in the predetermined range.
The drive device claims to drive a plurality of transfer rollers installed in the predetermined range while maintaining a state in which the warp direction of the transfer roller deviates from the warp direction of adjacent transfer rollers by the predetermined angle. 2. The heat treatment furnace according to 2. The heat treatment furnace according to claim 2 or 3, wherein the predetermined angle is 90 degrees. The heat treatment furnace according to claim 2 or 3, wherein the predetermined angle is 180 degrees. A heat treatment unit having a space for heat-treating the object to be treated,
A method for manufacturing a heat treatment furnace, which is arranged in the heat treatment section and includes a plurality of transfer rollers for conveying the object to be processed.
For each of the plurality of transport rollers installed in the predetermined range of the heat treatment section, a measurement step of measuring the warp direction of the portion where the warp of the transport roller is the largest when the transport roller is viewed along the axial direction. ,
A method for manufacturing a heat treatment furnace, comprising an installation step of installing the transfer roller so that the measured warp direction changes periodically for a predetermined range of the heat treatment section.

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