JP2016156612A - Heat treating furnace and heat treating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable rapid heat-up and down corresponding to various kinds of treated products.SOLUTION: In a heat treating furnace 10, with a state that atmosphere of a first space 11a is heated with a first heater 21a and atmosphere of a second space 11b is heated to higher temperature than the first space 11a with a second heater 21b, a treated product 96 transported in the first space 11a by a first transporting roller 20a is transported by a gear changeable transporting roller 20c at an appointed speed in a gear changeable range faster than the first and second transporting rollers 20a and 20b through a transporting passage 11c to the second transporting roller 20b. A gap height H of the transporting passage 11c is 25 to 35 mm. A transportation direction length L of the transporting passage 11c is more than 3 times of the gap height H.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a heat treatment furnace and a heat treatment method.

  Conventionally, a heat treatment furnace for heat-treating an object to be processed is known. For example, Patent Document 1 describes a roller hearth kiln that performs a heat treatment while transferring an object to be fired made of a base material and an electrode with a large number of rollers. In this roller hearth kiln, it is described that a high-speed transport region for transporting the product to be fired at a higher speed than the normal speed is provided in the middle of the normal transport region for transporting the product to be fired at a normal speed. In addition, it is described that a heating source having a higher output than that of the normal transfer region is provided in the furnace chamber of the high-speed transfer region. Thereby, it is said that the product to be fired can be rapidly heated in the high-speed conveyance region, and the contraction timing between the base material and the electrode in the product to be fired can be made closer.

JP 2009-229013 A

  By the way, when the temperature of the object to be processed is rapidly increased, the temperature difference between before and after the temperature increase needs to be an appropriate value corresponding to the object to be processed. However, the temperature difference before and after the temperature increase does not increase due to the influence of radiation from one side of the space before and after the temperature increase to the other, and there is a case where the temperature difference is not appropriate for the object to be processed. Similarly, when the temperature of the object to be processed is rapidly decreased, the temperature difference before and after the temperature decrease may not be an appropriate temperature difference corresponding to the object to be processed. Therefore, there has been a demand for a heat treatment furnace that can increase the temperature difference between the front and rear spaces and enable rapid temperature increase or decrease (rapid increase / decrease temperature) corresponding to various objects to be processed.

  The present invention has been made to solve such problems, and has as its main object to enable rapid temperature rise and fall corresponding to various objects to be processed.

The heat treatment furnace of the present invention is
A heat treatment furnace for performing heat treatment of a workpiece,
The first space, the second space, a passage that communicates the first space and the second space and conveys the object to be processed, and has a vertical gap height H of 25 mm or more and 35 mm or less. And a furnace body having a partition wall that partitions the first space and the second space,
Temperature adjusting means for differentiating the temperature of the atmosphere of the first space and the atmosphere of the second space;
Transport means for transporting the object to be processed in the order of the first space, the transport path, and the second space;
It is equipped with.

In the heat treatment furnace of the present invention, the workpiece is transported in the order of the first space, the transport path, and the second space in a state where the temperature of the atmosphere of the first space and the atmosphere of the second space are different. To do. As a result, the workpiece is rapidly raised and lowered by being transferred from the first space through the transfer passage to the second space having a different temperature. In the conveyance path, the vertical gap height H is 25 mm or more and 35 mm or less. By setting the gap height H to 35 mm or less, the radiation from one of the first space and the second space is suppressed from passing through the transport path and reaching the other. This makes it easy to increase the temperature difference between the atmosphere in the first space and the atmosphere in the second space. Therefore, it becomes easy to make the temperature difference before and after the temperature increase / decrease suitable for the object to be processed, and rapid temperature increase / decrease corresponding to various objects to be processed becomes possible. In addition, by setting the gap height H to 25 mm or more, it is possible to ensure a sufficient gap through which the workpiece is passed. Here, the gap height H is the size of the gap in the vertical direction when the conveyance path is viewed along the conveyance direction of the conveyance means. Further, when there is a portion where the size of the gap in the vertical direction when viewing the conveyance path along the conveyance direction of the conveyance means is different, the minimum value is set as the gap height H. Here, the said to-be-processed object is good also as what is conveyed by the said conveyance means in the state mounted in the setter.

  In the heat treatment furnace of the present invention, the temperature adjusting means includes first temperature adjusting means for heating or cooling the temperature of the atmosphere in the first space, and second temperature adjusting means for heating or cooling the atmosphere in the second space. It is good also as what has at least one of these. Further, the first temperature adjusting means may be a first heating means for heating the atmosphere of the first space, or may be a first cooling means for cooling the atmosphere of the first space. The second temperature adjusting unit may be a second heating unit that heats the atmosphere of the second space, or may be a second cooling unit that cools the atmosphere of the second space. In the case where the first heating unit is provided, the second heating unit may be a unit that heats the atmosphere of the second space to be higher than the temperature of the first space, and the atmosphere of the second space may be It is good also as a means to heat so that it may become low temperature rather than 1st space. When the first heating unit is provided, the second cooling unit may be a unit that cools the atmosphere of the second space so as to have a lower temperature than the first space. When the first cooling unit is provided, the second heating unit may be a unit that heats the atmosphere of the second space so as to be higher in temperature than the first space. When the first cooling unit is provided, the second cooling unit may be a unit that cools the atmosphere of the second space so as to have a higher temperature than the first space, and the atmosphere of the second space may be It is good also as a means to cool so that it may become low temperature rather than 1st space. The first heating means may heat the atmosphere of the first space to 500 ° C. to 850 ° C. The second heating means may heat the atmosphere of the second space to 1000 ° C. to 1350 ° C. The temperature adjusting means heats at least one of the first space and the second space so that a temperature difference between the atmosphere of the first space and the atmosphere of the second space is 400 ° C. to 600 ° C. Or it is good also as what cools.

  In the heat treatment furnace of the present invention, a length L in the transfer direction of the transfer passage may be three times or more the gap height H. By setting the conveyance direction length L to be three times or more the gap height H, radiation from one of the first space and the second space is prevented from passing through the conveyance path and reaching the other. Thereby, it becomes easy to increase the temperature difference between the atmosphere in the first space and the atmosphere in the second space, and rapid temperature increase / decrease corresponding to more types of objects to be processed becomes possible.

In the heat treatment furnace of the present invention, the transfer means includes a first transfer means for transferring the object to be processed in the first space, a second transfer means for transferring the object to be processed in the second space, The object to be processed conveyed to the first conveying means is conveyed to the second conveying means through the conveying path in a predetermined conveying direction, and more than the first conveying means and the second conveying means. And a variable speed transfer means capable of changing the speed of the transfer in a high speed variable speed region. The temperature raising / lowering speed (temperature change speed) of the workpiece changes according to the transport speed in the transport path, but the transport speed can be changed within the range of the variable speed region. Therefore, the temperature raising / lowering speed can be changed according to the object to be processed, and rapid temperature raising / lowering corresponding to various objects to be processed becomes possible. Here, the variable speed region is a region determined so that the temperature raising / lowering speed of the workpiece when passing through the transfer passage can be changed in a range of at least 150 ° C./min to 750 ° C./min. Or it is good also as an area | region determined so that it could change in the range of at least 150 degreeC / min-1000 degreeC / min. Moreover, the said to-be-processed object is good also as what is conveyed by the said 1st, 2nd conveyance means and the said variable speed conveyance means in the state mounted in the setter. In the case where the variable speed region is in the same numerical range, the range of changeable temperature increase / decrease speed increases as the temperature difference between the first and second spaces increases. Further, when the temperature difference between the first and second spaces is the same value, the range of the temperature increase / decrease rate that can be changed becomes wider as the variable speed region is a wider numerical range.

  In the heat treatment furnace of the present invention, speed acquisition means for acquiring a predetermined speed in the variable speed region during the heat treatment, and the variable speed transfer means for controlling the variable speed transfer means to transfer the object to be processed at the predetermined speed. Variable speed conveyance control means. In this case, the speed acquisition means may be means for inputting the predetermined speed from a user. Further, the speed acquisition means may be means for deriving the predetermined speed based on at least one of information input from a user and information stored in advance in the storage means.

  In the heat treatment furnace of the present invention, the transfer means has a plurality of transfer rollers for transferring the object to be processed in a horizontal direction which is a transfer direction in the transfer path, and the partition wall is perpendicular to the transfer path. An upper partition located on the upper side and a lower partition located vertically below the transport passage, wherein one or more upper ends of the lower partition are positioned between the plurality of transport rollers in the transport direction. In addition, it may be positioned at the same level as or above the lower ends of the plurality of transport rollers in the vertical direction. By doing so, it is possible to eliminate the upper and lower gaps between the lower end of the roller and the lower partition when the conveyance path is viewed along the conveyance direction. Thereby, radiation from one of the first space and the second space is suppressed from passing through this gap and reaching the other. Therefore, it becomes easy to increase the temperature difference between the atmosphere in the first space and the atmosphere in the second space, and rapid temperature increase / decrease corresponding to more types of objects to be processed becomes possible. Note that “transporting horizontally” includes cases where the heat treatment furnace is transported substantially horizontally, such as when manufacturing errors or deformation due to use have occurred, or when the mounting position of the heat treatment furnace is tilted from the horizontal. Meaning.

  In this case, the lower partition wall has one or more convex portions having the upper end portion, and the convex portion has a shape in which the width in the transport direction becomes smaller toward the upper end portion in the vertical direction. It may be. In other words, the convex portion may have a tapered shape toward the upper end portion when viewed from the direction perpendicular to the transport direction and the vertical direction in the transport path of the transport means. By doing this, the upper end of the lower partition wall is arranged between the plurality of transport rollers in the transport direction, and the roller and the lower partition wall (convex portion) are prevented from contacting when the lower partition wall is thermally expanded. It becomes easy.

The heat treatment method of the present invention comprises:
A first passage, a second space, a passage that communicates the first space and the second space and conveys an object to be processed, and a conveyance passage having a vertical gap height H of 25 mm or more and 35 mm or less. A heat treatment method for the object to be treated in a heat treatment furnace comprising a furnace body having a partition wall formed and partitioning the first space and the second space,
The step of transporting the object to be processed in the order of the first space, the transport path, and the second space in a state where the atmosphere of the first space and the atmosphere of the second space are different. ,
Is included.

  In the heat treatment method of the present invention, the object to be processed is rapidly raised and lowered by being transferred from the first space through the transfer passage to the second space having a different temperature. In the conveyance path, the vertical gap height H is 25 mm or more and 35 mm or less. By setting the gap height H to 35 mm or less, the radiation from one of the first space and the second space is suppressed from passing through the transport path and reaching the other. This makes it easy to increase the temperature difference between the atmosphere in the first space and the atmosphere in the second space. Therefore, it becomes easy to make the temperature difference before and after the temperature increase / decrease suitable for the object to be processed, and rapid temperature increase / decrease corresponding to various objects to be processed becomes possible. In addition, by setting the gap height H to 25 mm or more, it is possible to ensure a sufficient gap through which the workpiece is passed.

In the heat treatment method of the present invention, the conveyance direction length L of the conveyance passage may be three times or more the gap height H. By setting the conveyance direction length L to be three times or more the gap height H, radiation from one of the first space and the second space is prevented from passing through the conveyance path and reaching the other. Thereby, it becomes easy to increase the temperature difference between the atmosphere in the first space and the atmosphere in the second space, and rapid temperature increase / decrease corresponding to more types of objects to be processed becomes possible.

  In the heat treatment furnace of the present invention, the heat treatment furnace includes: a first transport unit that transports the workpiece in the first space; a second transport unit that transports the workpiece in the second space; The object to be processed conveyed to the first conveying means is conveyed to the second conveying means through the conveying path in a predetermined conveying direction, and more than the first conveying means and the second conveying means. Variable-speed transfer means capable of changing the transfer speed in a high-speed variable-speed region, and in the step, the atmosphere of the first space and the atmosphere of the second space are made different from each other. The workpiece conveyed in the first space by the first conveying means passes through the conveying path at a predetermined speed in the variable speed region by the variable speed conveying means to the second conveying means. It may be conveyed. The temperature raising / lowering speed (temperature change speed) of the workpiece changes according to the transport speed in the transport path, but the transport speed can be changed within the range of the variable speed region. Therefore, the temperature raising / lowering speed can be changed according to the object to be processed, and rapid temperature raising / lowering corresponding to various objects to be processed becomes possible.

  In the heat treatment method of the present invention, the variable speed region is determined so that the temperature change rate of the workpiece when passing through the transfer passage can be changed in a range of at least 150 ° C./min to 1000 ° C./min. In the step, the object to be processed is transported in a state of being placed on a setter, and the setter has a physical strength value at room temperature, a bending strength of 100 MPa to 250 MPa, and a Young's modulus of 200 GPa to 350 GPa, thermal expansion coefficient may be 4 ppm / K to 5 ppm / K, and thermal conductivity may be 50 W / mK to 200 W / mK. When the temperature change rate (temperature increase / decrease rate) of the workpiece can be changed within the above range, the heat resistance of the setter over the range of changeable temperature increase / decrease rate by using a setter that satisfies the above numerical range In addition, the temperature followability becomes sufficient. Thereby, even if the heating / cooling speed is changed, heat treatment can be performed using the same setter, and it is not necessary to prepare a plurality of types of setters corresponding to the heating / cooling speed. Here, the bending strength of the setter is a four-point bending strength.

  In this case, the setter may be made of Si-bonded SiC or recrystallized SiC. A setter made of Si-bonded SiC or recrystallized SiC can satisfy the above numerical ranges of bending strength, Young's modulus, thermal expansion coefficient, and thermal conductivity relatively easily, and is suitable for the heat treatment method of the present invention.

  In the heat treatment method of the present invention, the transfer means has a plurality of transfer rollers for transferring the object to be processed in a horizontal direction which is a transfer direction in the transfer path, and the partition wall is perpendicular to the transfer path. An upper partition located on the upper side and a lower partition located vertically below the transport passage, wherein one or more upper ends of the lower partition are positioned between the plurality of transport rollers in the transport direction. In addition, it may be positioned at the same level as or above the lower ends of the plurality of transport rollers in the vertical direction. By doing so, it is possible to eliminate the upper and lower gaps between the lower end of the roller and the lower partition when the conveyance path is viewed along the conveyance direction. Thereby, radiation from one of the first space and the second space is suppressed from passing through this gap and reaching the other. Therefore, it becomes easy to increase the temperature difference between the atmosphere in the first space and the atmosphere in the second space, and rapid temperature increase corresponding to more types of objects to be processed becomes possible.

  In this case, the lower partition wall has one or more convex portions having the upper end portion, and the convex portion has a shape in which the width in the transport direction becomes smaller toward the upper end portion in the vertical direction. It may be. By doing this, the upper end of the lower partition wall is arranged between the plurality of transport rollers in the transport direction, and the roller and the lower partition wall (convex portion) are prevented from contacting when the lower partition wall is thermally expanded. It becomes easy.

It is a longitudinal cross-sectional view of the heat treatment furnace 10 of 1st Embodiment. It is A view which looked at the conveyance path 11c periphery of FIG. 1 from the front. It is a perspective view of the conveyance path 11c periphery. It is a longitudinal cross-sectional view of the heat treatment furnace 110 of the second embodiment.

[First Embodiment]
Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view of a heat treatment furnace 10 according to the first embodiment of the present invention. FIG. 2 is an A view of the periphery of the conveyance path 11c of FIG. 1 as viewed from the front. FIG. 3 is a perspective view of the periphery of the conveyance path 11c. In addition, illustration of the outer wall 11 is abbreviate | omitted in FIG. The heat treatment furnace 10 includes a furnace body 10a, first and second transport rollers 20a and 20b, variable speed transport rollers 20c, first and second heaters 21a and 21b, gas supply devices 22 and 24, and flow rate adjustment. Valves 26 and 28 and a controller 80 are provided. This heat treatment furnace 10 is configured as a roller hearth kiln that heat-treats the workpiece 96 while conveying a setter 95 on which a plurality of workpieces 96 are placed inside the furnace body 10a.

  The furnace body 10 a includes an outer wall 11 and a partition wall portion 30 disposed in the outer wall 11. The outer wall 11 is a heat insulating structure formed in a substantially rectangular parallelepiped shape, and includes a first space 11a, a second space 11b, and a transport passage 11c, which are internal spaces. Further, the outer wall 11 is formed on the front end surface 12 (left end surface in FIG. 1) of the outer wall 11 and has an opening 14 serving as an entrance to the first space 11a from the outside, and a rear end surface 13 (right end surface in FIG. 1) of the outer wall 11. And an opening 15 serving as an outlet from the second space 11b to the outside. The first space 11 a is a space surrounded by the outer wall 11 and the partition wall portion 30. The second space 11 b is a space surrounded by the outer wall 11 and the partition wall portion 30. The transport passage 11 c is a space that allows the first space 11 a and the second space 11 b to communicate with each other, and is formed by the partition wall portion 30. The first space 11a, the conveyance path 11c, and the second space 11b are formed in this order from the opening 14 toward the opening 15 in the front-rear direction (left-right direction in FIG. 1).

The partition wall portion 30 is a heat insulating structure that partitions the first space 11a and the second space 11b, and includes an upper partition wall 31 positioned on the vertical upper side and a lower partition wall 35 positioned on the vertical lower side. A transport passage 11c is formed as a space sandwiched between the upper partition wall 31 and the lower partition wall 35 from the vertical direction. The upper partition wall 31 includes a main body 32 and a beam 33 (see the enlarged portion of the broken line frame S shown on the left side of FIG. 1). The main body portion 32 is a substantially rectangular parallelepiped member formed of, for example, bricks, and the upper end and the left and right ends are in contact with the outer wall 11. The main body 32 may be formed integrally or may be formed by combining a plurality of members. The beam 33 is a plate-like member that is formed of, for example, metal and the longitudinal direction is the left-right direction. The beam 33 is supported at the left and right ends of the outer wall 11, and the upper surface is in contact with the lower end of the main body 32 and supports the main body 32 from below. The lower partition wall 35 is a member formed of brick or the like, and includes a main body portion 36 and convex portions 37a and 37b. The main body 36 is a substantially rectangular parallelepiped member. The convex portions 37a and 37b are vertically upper portions of the lower partition wall 35 and are in contact with the main body portion 36 at the lower ends. The convex portions 37a and 38b are disposed adjacent to each other in the front-rear direction. The convex portions 37a and 37b are triangular columnar members whose cross section perpendicular to the left-right direction is a triangle (see FIG. 3). Therefore, the convex portions 37a and 37b are formed such that the width in the front-rear direction becomes smaller toward the upper vertical side. The upper end portions 38 a and 38 b that are the top portions of the convex portions 37 a and 37 b (the portions that become the apexes of the triangle when viewed in a cross section perpendicular to the left-right direction) are the upper end portions of the lower partition wall 35. In addition, the main-body part 36, the convex part 37a, and the convex part 37b may each be integrally formed, and may be formed combining several members. Moreover, the whole lower partition 35 may be integrally formed. The partition wall 30 is preferably formed of a material having low thermal conductivity.

  A plurality (eight in this embodiment) of first transport rollers 20a are disposed along the predetermined transport direction in the first space 11a, and are transport rollers that transport the setter 95. In the present embodiment, the transport direction of the first transport roller 21a is a horizontal direction, which is a direction from the front to the rear (a direction from the left side to the right side in FIG. 1). As the first transport roller 20a rotates, the setter 95 on which a plurality of objects to be processed 96 are placed is transported from the opening 14 in the first space 11a in the transport direction.

  A plurality (eight in this embodiment) of second transport rollers 20b are disposed along the predetermined transport direction in the second space 11b, and are transport rollers that transport the setter 95. In the present embodiment, the transport direction of the second transport roller 20b is the same as the transport direction of the first transport roller 20a. As the second transport roller 20b rotates, the setter 95 on which the plurality of objects to be processed 96 are placed is transported in the transport direction to the opening 15 in the second space 11b.

  The variable speed conveyance roller 20 c is a conveyance roller that is disposed between the first conveyance roller 20 a and the second conveyance roller 20 b and conveys the setter 95. A plurality (10 in this embodiment) of variable speed transport rollers 20c are arranged along a predetermined transport direction from the first space 11a to the second space 11b via the transport path 11c. . In the present embodiment, the conveyance direction of the variable speed conveyance roller 20c is the same as the conveyance direction of the first conveyance roller 20a. As the variable speed transport roller 20c rotates, the setter 95 on which a plurality of objects to be processed 96 are placed is transported in the transport direction through the transport path 11c. In addition, the roller located most upstream in the conveyance direction among the variable speed conveyance rollers 20c is arranged next to the roller located most downstream in the conveyance direction among the first conveyance rollers 20a, and the distance between both rollers is setter. It is the distance which can deliver 95. Similarly, the roller located most downstream in the conveyance direction among the variable speed conveyance rollers 20c is arranged next to the roller located most upstream in the conveyance direction among the second conveyance rollers 20b, and the distance between the two rollers is mutually It is the distance that the setter 95 can deliver. Thereby, the variable speed conveyance roller 20c conveys the setter 95 conveyed by the 1st conveyance roller 20a to the 2nd conveyance roller 20b through the conveyance path 11c. In the present embodiment, all of the first and second transport rollers 20a and 20b and the variable speed transport roller 20c have the same diameter, and are arranged at equal intervals in the front-rear direction from the opening 14 to the opening 15. It was supposed to be. The variable speed transport roller 20c can be rotated at a higher speed than the first and second transport rollers 20a and 20b by a motor (not shown), and the rotational speed can be adjusted. Thereby, the variable speed conveyance roller 20c can change the conveyance speed of the setter 95 within the variable speed region higher than the conveyance speed of the first and second conveyance rollers 20a and 20b. Although not particularly limited to this, in the present embodiment, the variable speed region is in the range of 90 mm / min to 600 mm / min.

  The first heater 21a is disposed in the first space 11a. A plurality of the first heaters 21a (four each in the upper and lower parts in this embodiment) are arranged on the ceiling and bottom of the outer wall 11 so as to sandwich the first transport roller 20a and the variable speed transport roller 20c from above and below. The first heaters 21 a are arranged such that the longitudinal direction is a direction (left-right direction) orthogonal to the conveyance direction, and a plurality of first heaters 21 a are arranged along the conveyance direction. The 1st heater 21a heats the to-be-processed object 96 which passes the inside of the 1st space 11a, and the atmosphere of the 1st space 11a, for example, is comprised as ceramic heaters, such as a SiC heater.

The second heater 21b is disposed in the second space 11b. A plurality of the second heaters 21b (up and down in this embodiment) are arranged on the ceiling and bottom of the outer wall 11 so as to sandwich the second transport roller 20b and the variable speed transport roller 20c from above and below. The second heater 21b is arranged such that the longitudinal direction is a direction (left-right direction) orthogonal to the conveyance direction, and a plurality of second heaters 21b are arranged along the conveyance direction. The second heater 21b heats the atmosphere of the workpiece 96 and the second space 11b passing through the second space 11b to a temperature higher than that of the first space 11a, and is configured as a ceramic heater such as a SiC heater. ing.

  The gas supply devices 22 and 24 supply an inert gas such as nitrogen to the first and second spaces 11a and 11b, respectively, as an atmospheric gas. The gas supply devices 22 and 24 may be devices that supply an atmospheric gas at a predetermined temperature (for example, room temperature) as it is, or may be devices that supply the atmospheric gas after it is heated. A gas supply port 16 connected to the gas supply device 22 is formed on the rear end face 13 side of the first space 11 a in the bottom of the outer wall 11. The atmospheric gas from the gas supply device 22 is supplied to the first space 11a through the gas supply port 16. Similarly, a gas supply port 17 connected to the gas supply device 24 is formed on the rear end face 13 side of the second space 11 b in the bottom of the outer wall 11. The atmospheric gas from the gas supply device 24 is supplied to the second space 11b through the gas supply port 17.

  The flow rate adjusting valves 26 and 28 are devices for adjusting the flow rate of the atmospheric gas flowing out from the furnace body 10a. An outlet 18 connected to the flow rate adjusting valve 26 is formed on the front end face 12 side of the first space 11 a in the ceiling portion of the outer wall 11. The flow rate adjusting valve 26 adjusts the flow rate when the atmosphere of the first space 11a flows out through the outlet 18. Similarly, an outlet 19 connected to the flow rate adjusting valve 28 is formed on the front end face 12 side of the second space 11 b in the ceiling portion of the outer wall 11. The flow rate adjusting valve 28 adjusts the flow rate when the atmosphere of the second space 11 b flows out through the outflow port 19. The atmospheric gas in the furnace body 10a that has passed through the flow control valves 26 and 28 may be exhausted, or after removing unnecessary components such as oxygen and water, for example, the intake air of the gas supply devices 22 and 24 It is good also as what circulates as.

  Here, the positional relationship between the variable speed conveyance roller 20c and the lower partition 35, the gap height H and the conveyance direction length L of the conveyance path 11c will be described. First, the positional relationship between the variable speed conveyance roller 20c and the lower partition wall 35 will be described. As shown in FIGS. 1 and 3, the upper end portions 38 a and 38 b of the lower partition wall 35 described above are positioned between two adjacent rollers of the variable speed transport roller 20 c in the transport direction. Further, the upper end 38a and the upper end 38b have the same height (the position in the vertical direction) and are positioned at the same height as the lower end of the roller of the variable speed transport roller 20c.

Next, the gap height H of the conveyance path 11c will be described. As for conveyance path 11c, it is preferred that the gap height H (refer to Drawings 1 and 2) of the perpendicular direction is 25 mm-35 mm. Here, the gap height H is the size of the gap in the vertical direction when the conveyance path 11c is viewed along the conveyance direction of the variable speed conveyance roller 20c (corresponding to a view A in FIG. 1). As shown in FIG. 2, when the transport path 11c is viewed along the transport direction of the variable speed transport roller 20c, the gap between the transport path 11c is seen from the upper end of the variable speed transport roller 20c to the lower end of the upper partition wall 31. It is. Therefore, the size of the gap in the vertical direction is the gap height H. In the present embodiment, the lower end portion of the upper partition wall 31 is parallel to the transport direction, and in FIG. If the lower end portion of the upper partition wall 31 does not appear in the left-right direction straight line in FIG. 2 (having irregularities, tilted from the left-right direction, etc.), the clearance height of the transport passage 11c depends on the position in the left-right direction. Is not constant, the minimum gap height in FIG. That is, when there is a portion where the size of the gap in the vertical direction when viewing the conveyance path 11c along the conveyance direction of the variable speed conveyance roller 20c is different, the minimum value is set as the gap height H. Moreover, in this embodiment, since the upper end part 38a and the upper end part 38b are located in the same height as the lower end of the roller of the variable speed conveyance roller 20c as mentioned above, the lower partition 35 and the variable speed conveyance roller 20c There is no gap between them. If there is a gap between them, the height of the gap between the upper partition wall 31 and the variable speed conveyance roller 20c (the minimum value) and the height of the gap between the lower partition wall 35 and the variable speed conveyance roller 20c (of The sum of “minimum value” is defined as the gap height H. As described above, when there are a plurality of gaps whose vertical positions are different when the conveyance path 11c is viewed along the conveyance direction of the variable speed conveyance roller 20c, the sum of the heights (minimum values) of the gaps is calculated as follows: The clearance height H of the conveyance path 11c is set.

  Next, the conveyance direction length L of the conveyance path 11c will be described. The conveyance path 11c preferably has a length L in the conveyance direction that is three times or more the gap height H, and more preferably four times or more. Here, the conveyance direction length L is a distance from the upstream opening to the downstream opening in the conveyance direction of the variable speed conveyance roller 20c in the partition wall 30 as illustrated. In the present embodiment, the transport direction lengths (thicknesses) of the upper partition wall 31 and the lower partition wall 35 are constant in the vertical vertical direction, and the transport direction lengths (thicknesses) of the partition wall part 30 from the ceiling to the bottom of the outer wall 11. Is the same as the length L in the conveying direction.

  Note that the length of the transport passage 11c in the left-right direction (the length in the horizontal direction perpendicular to the transport direction) is, for example, 300 mm to 1500 mm.

  The controller 80 is configured as a microprocessor centered on a CPU 81, and communicates with a flash memory 82 that stores various processing programs and various data, a RAM 84 that temporarily stores data, an operation panel 88, and the like. Internal communication interface (I / F). The flash memory 82 stores correspondence data 83. The correspondence relationship data 83 is data representing a correspondence relationship between the temperature of the first and second spaces 11a, the temperature rising speed when the setter 95 passes through the transport passage 11c, and the transport speed of the variable speed transport roller 20c. is there.

  The controller 80 outputs control signals to the gas supply devices 22 and 24 to individually control the supply amount and supply temperature of the inert gas into the furnace body 10a via the gas supply port 16 and the gas supply port 17. To do. The controller 80 outputs control signals to the flow rate adjusting valves 26 and 28 to individually control the amount of atmospheric gas flowing out from the outlets 18 and 19. Further, the controller 80 outputs control signals to the first and second heaters 21a and 21b to individually adjust the temperatures of the first space 11a and the second space 11b, and the first and second transport rollers 20a and 20b. And a drive signal is output to the motor which is not illustrated of the variable speed conveyance roller 20c, and the 1st, 2nd conveyance rollers 20a and 20b and the variable speed conveyance roller 20c are rotated. In addition, the controller 80 inputs an operation signal generated in response to an operation on the operation panel 88 or outputs a display command to the operation panel 88.

  Further, as shown in FIG. 1, the controller 80 includes a speed acquisition unit 85, a conveyance control unit 86, and the like as functional blocks. The speed acquisition unit 85 is information regarding the temperature of the first and second spaces 11a and 11b input from the user via the operation panel 88, and information regarding the temperature increase rate when the workpiece 96 passes through the transport path 11c. And a function for acquiring a value related to the transport speed of the variable speed transport roller 20c during the heat treatment corresponding to the temperature and the temperature increase rate of the input first and second spaces 11a and 11b based on the correspondence relationship data 83. Have The conveyance control unit 86 has a function of controlling the rotation speed of a motor (not shown) of the variable speed conveyance roller 20c so that the setter 95 passes through the conveyance path 11c at the conveyance speed acquired by the speed acquisition unit 85. The speed acquisition unit 85 and the conveyance control unit 86 may be configured as hardware, or may be configured as software that exhibits functions by the CPU 81 executing a program stored in the flash memory 82. .

The operation panel 88 includes a display unit and an operation unit configured to include the display unit. The display unit is configured as a touch panel type liquid crystal display, and displays a selection / setting button for selecting menus and items, a numeric button for inputting various numerical values, a start button for starting heat treatment, and the like for touch operation. An operation signal based on the reception and touch operation is transmitted to the controller 80. When a display command is received from the controller 80, an image, a character, a numerical value, or the like based on the display command is displayed on the display unit.

  The setter 95 is for placing an object 96 to be processed. The setter 95 is only required to be transported by the first and second transport rollers 20a and 20b and the variable speed transport roller 20c with the workpiece 96 placed thereon. For example, the setter 95 may have a flat plate shape or a mesh shape. Also good. Further, the setter 95 includes, for example, a plurality of flat plates and a support member that supports the flat plates while being spaced apart from each other in the vertical direction, and may have a plurality of stages on which the workpiece 96 can be placed. In the present embodiment, the length of the setter 95 in the transport direction is longer than the length L of the transport path 11c in the transport direction. The setter 95 is preferably made of a material having high corrosion resistance and heat resistance so that it can withstand the heat treatment of the workpiece 96 in the furnace body 10a. Moreover, it is preferable that the setter 95 is made of a material that hardly causes its own temperature distribution (high temperature followability) so that the plurality of objects to be processed 96 can be heat-treated more uniformly. More specifically, the setter 95 has a bending strength of 100 MPa to 250 MPa, a Young's modulus of 200 GPa to 350 GPa, a thermal expansion coefficient of 4 ppm / K to 5 ppm / K, and a thermal conductivity of 50 W / mK to 200 W / mK. Is preferred. These values are the physical property values at room temperature. The bending strength of the setter 95 is a four-point bending strength. The setter 95 is made of, for example, ceramics, and is preferably made of Si-bonded SiC (Si—SiC) or recrystallized SiC. If the setter 95 is composed of Si-bonded SiC or recrystallized SiC, it is easy to satisfy the above numerical ranges of bending strength, Young's modulus, thermal expansion coefficient, and thermal conductivity.

  In addition, the setter 95 which consists of Si bond SiC which satisfy | fills the said numerical range can be manufactured as follows, for example. First, a raw material for molding containing SiC powder as a main component, a raw material for molding containing a binder and water is kneaded and formed into the shape of a setter 95 to obtain a molded body. Next, the molded body is placed in a reduced-pressure inert gas atmosphere or vacuum under a metal Si atmosphere, and the molded body is impregnated with metal silicon (for example, until the porosity becomes 1% or less) to form Si bonds. A sintered body of SiC is used as a setter 95. The base material may contain C powder, and preferably contains Al, Fe, and Co as trace components. In addition, the manufacturing method of the setter which consists of such Si bond SiC is described in Unexamined-Japanese-Patent No. 2012-56831, for example.

  The workpiece 96 is subjected to heat treatment such as firing by heat from the first and second heaters 21a and 21b when passing through the furnace body 10a. Although not particularly limited, in the present embodiment, the object to be processed 96 is a laminated body (dimensions are within 1 mm in length and width, for example) in which a ceramic dielectric (base material) and electrodes are laminated, and after firing. The chip was a ceramic capacitor chip. In the present embodiment, the object to be processed 96 is preheated at, for example, 800 ° C. to 900 ° C. before being heat-treated in the heat treatment furnace 10, and the binder of the object to be processed 96 is removed and semi-sintered. It was supposed to be kept.

  Next, how the heat treatment of the workpiece 96 is performed using the heat treatment furnace 10 thus configured will be described. First, the user operates the operation panel 88 to input various setting values such as heat treatment conditions, and presses the start button. The various setting values input from the user by the operation panel 88 include, for example, information on the temperature of the first and second spaces 11a and 11b and the temperature increase rate when the setter 95 passes through the transport path 11c. The various set values include information on the supply amount (supply speed) and temperature of the atmospheric gas from the gas supply devices 22 and 24, the flow rate of the atmospheric gas flowing through the flow rate adjusting valves 26 and 28, and the like.

When these values are input and the start button is pressed, the controller 80 inputs various setting values from the user in response to an operation signal from the operation panel 88 and stores them in the RAM 84, and heat treatment based on the stored various setting values. To start. Specifically, the controller 80 is based on the input information regarding the supply amount (supply speed) and temperature of the atmospheric gas from the gas supply devices 22 and 24, the flow rate of the atmospheric gas flowing through the flow rate adjusting valves 26 and 28, and the like. The control signals are output to the gas supply devices 22 and 24 and the flow rate adjusting valves 26 and 28. Moreover, based on the input information regarding the temperature of the first and second spaces 11a and 11b, a control signal is output to the first and second heaters 21a and 21b. Thereby, the atmosphere of the 1st, 2nd space 11a, 11b turns into an inert gas atmosphere, and the atmosphere of the 1st space 11a, the 2nd space 11b is heated. As described above, the second space 11b is heated to a higher temperature than the first space 11a. In the present embodiment, the first space 11a is heated to 700 ° C. and the second space 11b is heated to 1200 ° C. In the present embodiment, the sum of the inflow amounts of the atmospheric gas into the furnace body 10 a by the gas supply device 22 and the gas supply device 24, and the atmospheric gas from the furnace body 10 a by the flow rate adjustment valve 26 and the flow rate adjustment valve 28. The outflow amount from the flow rate adjusting valve 28 is made smaller than the inflow amount from the gas supply device 24. By doing so, part of the atmospheric gas in the second space 11b flows out of the outlet 18 through the transport passage 11c and the first space 11a. Therefore, part of the atmospheric gas heated to a high temperature in the second space 11b can be used for heating the first space 11a, and the first space 11a can be efficiently heated.

  After completing the adjustment of the atmosphere in the first space 11a and the second space 11b in this way, the controller 80 outputs a control signal to a motor (not shown), and the first transport roller 20a, the second transport roller 20b, and the variable speed transport roller. Rotate 20c. And the to-be-processed object 96 is carried in into the furnace body 10a from the opening 14 with the conveyance apparatus which is not shown in figure by a user. The loaded object 96 is transported in this order in the first space 11a, the transport path 11c, and the second space 11b by the first transport roller 20a, the variable speed transport roller 20c, and the second transport roller 20b. It is carried out from the opening 15. During this time, the object 96 is heat-treated. Note that the setter 95 on which the workpiece 96 is placed is sequentially carried into the heat treatment furnace 10 so that the workpiece 96 is continuously heat-treated. A space (not shown) for cooling the workpiece 96 is formed downstream of the opening 15 in the transport direction, and the workpiece 96 carried out from the opening 15 is cooled by a predetermined temperature drop while being transported through the space. The temperature is lowered at a speed (for example, from the temperature of the second space 11b to room temperature).

  In addition, the conveyance speed of the 1st conveyance roller 20a at the time of heat processing and the 2nd conveyance roller 20b shall be the same speed in this embodiment, and is predetermined as a speed lower than the variable speed area | region of the variable speed conveyance roller 20c mentioned above. It was supposed to be. Moreover, the conveyance speed of the variable speed conveyance roller 20c shall be controlled as follows. First, the speed acquisition unit 85 reads the temperatures of the first and second spaces 11a and 11b stored in the RAM 84 and the temperature increase rate when the workpiece 96 passes through the transport path 11c. Then, based on the read data and the correspondence data 83, the speed acquisition unit 85 transports the variable speed transport roller 20c to heat the workpiece 96 at the temperature rising speed input by the user. A value related to (conveying speed within the above-described variable speed region) is acquired. Subsequently, the conveyance control unit 86 controls the rotation speed of a motor (not shown) of the variable speed conveyance roller 20c so that the setter 95 passes through the conveyance path 11c at the conveyance speed acquired by the speed acquisition unit 85. The correspondence represented by the correspondence data 83 may be a table or a calculation formula. This correspondence data 83 can be obtained in advance by experiment, for example.

In the present embodiment, when the first space 11a is 700 ° C. and the second space 11b is 1200 ° C., the conveyance speed of the variable speed conveyance roller 20c is changed within the above-described variable speed region, thereby conveying the conveyance path. The temperature increase rate of the workpiece 96 when passing through 11c can be changed in a range of at least 150 ° C./min to 1000 ° C./min. The user inputs an appropriate temperature increase rate according to the material of the workpiece 96 within the range of the temperature increase rate. By setting the temperature increase rate to an appropriate value, the temperature of the object to be processed 96 is rapidly increased from the first space 11a to the second space 11b, and the contraction timing between the base material of the object to be processed 96 and the electrode is set. It can approach, and generation | occurrence | production of the crack at the time of baking, peeling, etc. by the temperature rising rate being too low can be suppressed. In addition, non-uniform firing due to an excessively high temperature rise rate can be suppressed. Note that if the temperature of the first and second spaces 11a and 11b (especially the temperature difference between the two spaces) is set to another value, the temperature increase rate that can be adjusted also changes in the same variable speed region. For example, you may determine the temperature of both space so that the temperature difference of the 1st space 11a and the 2nd space 11b may be 400 to 600 degreeC.

  Here, the correspondence between the components of the first embodiment and the components of the present invention will be clarified. The first space 11a of the present embodiment corresponds to the first space of the present invention, the second space 11b corresponds to the second space, the transport passage 11c corresponds to the transport passage, the partition wall 30 corresponds to the partition, The furnace body 10a corresponds to the furnace body, the first and second heaters 21a and 21b correspond to the temperature adjusting means, the first heater 21a corresponds to the first temperature adjusting means and the first heating means, and the second heater 21b. Corresponds to the second temperature adjusting means and the second heating means, the first and second transport rollers 20a, 20b and the variable speed transport roller 20c correspond to the transport means, and the first transport roller 20a corresponds to the first transport means. The second transport roller 20b corresponds to the second transport unit, and the variable speed transport roller 20c corresponds to the variable speed transport unit. The speed acquisition unit 85 corresponds to a speed acquisition unit, and the conveyance control unit 86 corresponds to a conveyance control unit.

  In the heat treatment furnace 10 of the first embodiment described above, the atmosphere of the first space 11a is heated by the first heater 21a, and the atmosphere of the second space 11b is heated to a higher temperature than the first space 11a by the second heater 21b. The workpiece 96 conveyed in the first space 11a by the first conveying roller 20a while being heated to a variable speed region that is faster than the first and second conveying rollers 20a, 20b by the variable speed conveying roller 20c. It passes through the inside of the transport passage 11c at a predetermined speed and is transported to the second transport roller 20b. As a result, the workpiece 96 is rapidly heated from the first space 11a through the transfer passage 11c and transferred to the high temperature second space 11b at high speed. The temperature rising speed at this time changes according to the conveying speed in the conveying passage 11c, but this conveying speed can be changed within the range of the variable speed region. Therefore, the temperature increase rate can be changed according to the object to be processed 96, and rapid temperature increase corresponding to various objects to be processed 96 becomes possible. Note that an appropriate rate of temperature increase when the object 96 is rapidly heated varies depending on the material contained in the object 98, the size of the object 96, and the like. For example, if the rate of temperature increase is too low, cracking or peeling may occur due to a difference in shrinkage between different materials in the workpiece 96. In addition, if the temperature raising rate is too high, only the surface of the workpiece 96 may be fired first, and firing may be non-uniform. In the heat treatment furnace 10 of the first embodiment, this can be suppressed and rapid temperature increase corresponding to various objects to be processed 96 can be achieved.

Further, by setting the gap height H of the transport passage 11c to 35 mm or less, it is possible to suppress the radiation from the second space 11b from passing through the transport passage 11c and reaching the first space 11a. Thereby, it is easy to increase the temperature difference between the atmosphere in the first space 11a and the atmosphere in the second space 11b. When the variable speed region is in the same numerical range, the changeable temperature increase rate range becomes wider as the temperature difference between the first and second spaces 11a and 11b is larger. In addition, in order to appropriately rapidly raise the temperature of the workpiece 96, it is necessary to set not only the rate of temperature increase but also the temperature difference before and after the temperature increase to an appropriate value. Therefore, by making it easy to increase the temperature difference between the first and second spaces 11a and 11b, rapid temperature increase corresponding to more types of objects to be processed 96 becomes possible. In addition, by setting the gap height H to 25 mm or more, a gap through which the workpiece 96 and the setter 95 pass can be sufficiently secured. Note that the height of the setter 95 and the workpiece 96 is not considered in the gap height H. However, when the setter 95 and the workpiece 96 pass through the transport path 11 c, the vertical gap in the actual transport path 11 c is further narrowed by the height of the setter 95 and the workpiece 96. Therefore, the presence of the setter 95 and the workpiece 96 works in a direction that tends to increase the temperature difference between the atmosphere in the first space 11a and the atmosphere in the second space 11b. Therefore, there is no problem even if these heights are not considered in the gap height H.

  Furthermore, by setting the conveyance direction length L of the conveyance path 11c to be not less than three times the gap height H, the radiation from the second space 11b passes through the conveyance path 11c and reaches the first space 11b. More suppressed. Thereby, it becomes easy to increase the temperature difference between the atmosphere of the first space 11a and the atmosphere of the second space 11b, and rapid temperature increase corresponding to more types of objects to be processed 96 becomes possible.

  Furthermore, the variable speed transport roller 20c has a plurality of rollers for transporting the workpiece 96 horizontally in the transport path 11c, and the partition wall portion 30 is an upper partition wall 31 positioned vertically above the transport path 11c. And a lower partition wall 35 positioned vertically below the conveyance path 11c. The upper end portions 38a and 38b of the lower partition wall 35 are positioned between the plurality of variable speed transport rollers 20c in the transport direction and at the same height as the lower ends of the plurality of variable speed transport rollers 20c in the vertical direction. Yes. By doing so, it is possible to eliminate the vertical gap between the lower end of the variable speed conveyance roller 20c and the lower partition wall 35 when the conveyance path 11c is viewed along the conveyance direction. Thereby, the radiation from the second space 11b is prevented from passing through this gap and reaching the first space 11a. Therefore, it becomes easy to increase the temperature difference between the atmosphere in the first space 11a and the atmosphere in the second space 11b, and rapid temperature increase corresponding to more types of objects to be processed 96 becomes possible.

  Further, the lower partition wall 35 has convex portions 37a and 37b having upper end portions 38a and 38b, and the convex portions 37a and 37b have a width in the transport direction toward the upper end portions 38a and 38b in the vertical direction. It has a smaller shape. In this way, the variable speed transport roller 20c and the lower partition wall are disposed when the lower partition wall 35 is thermally expanded while the upper end portions 38a and 38b of the lower partition wall 35 are disposed between the plurality of variable speed transport rollers 20c in the transport direction. It is easy to avoid contact with 35 (particularly the convex portions 37a and 37b).

  In addition, the variable speed region of the variable speed transport roller 20c can change the temperature increase rate of the workpiece 96 when passing through the transport path 11c at least in the range of 150 ° C./min to 1000 ° C./min. This is a defined area. In the heat treatment, the workpiece 96 is transported while being placed on the setter 95. At this time, the setter 95 is a physical property value at room temperature, bending strength is 100 MPa to 250 MPa, Young's modulus is 200 GPa to 350 GPa, thermal expansion coefficient is 4 ppm / K to 5 ppm / K, and thermal conductivity is 50 W / mK to 200 W. By setting it to / mK, the heat resistance and temperature followability of the setter are sufficient over the range of the temperature increase rate that can be changed. Thereby, even if the temperature increase rate is changed, heat treatment can be performed using the same setter 95, and it is not necessary to prepare a plurality of types of setters 95 corresponding to the temperature increase rate. If the setter 95 is made of Si-bonded SiC or recrystallized SiC, the above numerical ranges of bending strength, Young's modulus, thermal expansion coefficient, and thermal conductivity can be satisfied relatively easily. In the present embodiment, the length of the setter 95 in the transport direction is longer than the length L of the transport path 11c in the transport direction. When such a setter 95 passes through the transport passage 11c, even if a part of the setter 95 on the upstream side in the transport direction reaches the second space 11b, a part of the setter 95 on the downstream side in the transport direction is still in the first space 11a. Will exist within. In this case, the setter 95 tends to have a temperature difference between the upstream side and the downstream side, and its own temperature distribution is likely to occur. By making the setter 95 satisfy the thermal conductivity of 50 W / mK to 200 W / mK in the above numerical range, the temperature distribution of the setter 95 can be suppressed even in such a case, and the workpiece 96 can be more Heat treatment can be performed uniformly.

[Second Embodiment]
Next, a second embodiment will be described. FIG. 4 is a longitudinal sectional view of a modified heat treatment furnace 110. The heat treatment furnace 110 is further provided in the third space 1 downstream (backward) in the transport direction of the second space 11b.
The configuration is the same as that of the heat treatment furnace 10 except that it includes a point 11b and a partition 130 that partitions the second space 11b and the third space 111b. In FIG. 4, the illustration of the configuration of the heat treatment furnace 110 on the upstream side in the transport direction from the transport passage 11c (for example, the first space 11a) is omitted. Moreover, about the heat processing furnace 110, the same code | symbol is attached | subjected about the same component as the heat processing furnace 10 mentioned above, description is abbreviate | omitted, and a different component is demonstrated below.

  The heat treatment furnace 110 includes a furnace body 110a, a third transport roller 120b, a gas supply device 124, a flow rate adjustment valve 128, a cooling pipe 140, air cooling jackets 142 and 144, and refrigerant supply sources 146 and 148. I have. The furnace body 10 a includes an outer wall 111 and a partition wall 130 disposed in the outer wall 111. The outer wall 111 is obtained by further extending the outer wall 11 rearward, and has a transfer passage 111c and a third space 111b, which are internal spaces, in this order behind the second space 11b. The outer wall 111 has an opening 115 formed on the rear end surface 113 of the outer wall 111 and serving as an outlet from the third space 111b to the outside. The third space 111 b is a space surrounded by the outer wall 111 and the partition wall 130. The conveyance path 111c is a space that allows the second space 11b and the third space 111b to communicate with each other, and is formed by the partition wall 130.

  The partition wall portion 130 includes an upper partition wall portion 131 including a main body portion 132 and a beam 133, and a lower partition wall portion 135 including a main body portion 136 and convex portions 137a and 137b (broken lines shown on the left side in FIG. 4). (See enlarged portion of frame S2). The convex portions 137a and 137b are provided with upper end portions 138a and 138b which are top portions. The partition wall portion 30 is the partition wall portion 30 except that the second space 11b and the third space 111b are partitioned, and the third transport roller 120b is disposed in the transport path 111c instead of the variable speed transport roller 20c. It is the same composition as.

  A plurality of (14 in the present embodiment) third transport rollers 120b are disposed along the horizontal direction, which is a predetermined transport direction, in the transport path 111c and the third space 111b, and are transport rollers that transport the setter 95. . When the third transport roller 120b rotates, the setter 95 transported by the second transport roller 20b passes through the transport path 111c and the third space 111b and is transported to the opening 115 in the transport direction.

  The gas supply device 124 has the same configuration as the gas supply device 24, and the atmosphere in the third space 111b is formed through a gas supply port 117 formed on the rear end surface 113 side of the third space 111b in the bottom of the outer wall 111. Supply gas. In the present embodiment, the gas supply device 124 supplies an atmospheric gas of 20 ° C., for example, to cool the third space 111b.

  The flow rate adjustment valve 128 has the same configuration as the flow rate adjustment valve 28, and is connected to an outlet 119 formed on the front end face 12 side (front side) of the third space 111 b in the ceiling portion of the outer wall 111. The flow rate adjustment valve 128 adjusts the flow rate when the atmosphere of the third space 111b flows out through the outflow port 119.

  A plurality of cooling pipes 140 (three in the upper and lower parts in this embodiment) are arranged on the ceiling and bottom of the outer wall 111 in the third space 111b so as to sandwich the third transport roller 120b from above and below. A cooling pipe (for example, air) can pass through the cooling pipe, and the inside of the third space 111b is cooled by this cooling medium.

The air cooling jackets 142 and 144 cool the third space 111b, and are disposed on the ceiling and the bottom of the outer wall 111, respectively. The surfaces of the air cooling jackets 142 and 144 are exposed in the third space 111b, and the refrigerant (air) from the refrigerant supply sources 146 and 148 can pass therethrough. The air cooling jackets 142 and 144 are formed in the third space 1 by this refrigerant.
The third space 111b is cooled through the surface exposed to 11b. In addition, many unevenness | corrugations are formed in the exposed surface in the 3rd space 111b of the air-cooling jackets 142 and 144, and the contact area with the 3rd space 111b is increased, and the cooling efficiency is improved.

  In the heat treatment furnace 110 configured as described above, when the heat treatment of the workpiece 96 is started, the controller 80 supplies the atmospheric gas supply amount and temperature from the gas supply device 124, the flow rate of the atmospheric gas flowing through the flow rate adjustment valve 128, The supply amount and temperature of the refrigerant (air) passing through the cooling pipe 140 and the air cooling jackets 142 and 144 are controlled. As a result, the atmosphere of the third space 111b becomes an inert gas atmosphere, and the third space 111b has a temperature (for example, 500 ° C. to 650 ° C.) lower than the temperature (for example, 1200 ° C.) of the second space 11b. To be cooled. The atmosphere in the first space 11a and the second space 11b is adjusted in the same manner as in the heat treatment furnace 10.

  Then, after completing the adjustment of the atmosphere in the first space 11a, the second space 11b, and the third space 111b, the controller 80 outputs a control signal to a motor (not shown), and the first transport roller 20a and the second transport roller. 20b, the variable speed conveyance roller 20c, and the third conveyance roller 120b are rotated. And the to-be-processed object 96 is carried in into the furnace body 10a from the opening 14 with the conveyance apparatus which is not shown in figure by a user. The workpiece 96 that has been carried in is conveyed in this order in the first space 11a, the conveyance path 11c, and the second space 11b by the first conveyance roller 20a, the variable speed conveyance roller 20c, and the second conveyance roller 20b. Then, the heat treatment (firing) of the workpiece 96 is performed. And the to-be-processed object 96 after baking is conveyed in this order in the conveyance path 111c and the 3rd space 111b by the 3rd conveyance roller 120b. At this time, the workpiece 96 is rapidly cooled at a predetermined temperature decrease rate due to the temperature difference between the second space 11b and the third space 111b. Thereafter, the object to be processed 96 is carried out from the opening 115 and lowered to the outside air temperature (for example, normal temperature). Note that the temperature of the third space 111b (temperature difference from the second space 11b and the outside air) is determined in advance so that the workpiece 96 after baking can be appropriately cooled. For example, the temperature of the third space 111b may be determined so that the temperature difference between the second space 11b and the third space 111b is 400 ° C. to 600 ° C.

  Here, the correspondence between the constituent elements of the second embodiment and the constituent elements of the present invention will be clarified. The second embodiment includes the same correspondence relationship as that of the first embodiment described above, but the description of the same correspondence relationship is omitted, and the correspondence relationship (mainly different from the first embodiment). The correspondence between the components related to the third space 111b and the present invention will be described below. The second space 11b of the present embodiment corresponds to the first space of the present invention, the third space 111b corresponds to the second space, the transport passage 111c corresponds to the transport passage, the partition wall 130 corresponds to the partition, The furnace body 110a corresponds to the furnace body, the second heater 21b, the gas supply device 124, the flow rate adjustment valve 128, the cooling pipe 140, the air cooling jackets 142 and 144, the refrigerant supply sources 146 and 148 correspond to the temperature adjusting means, The two heaters 21b correspond to the first temperature adjusting means and the first heating means, and the gas supply device 124, the flow rate adjusting valve 128, the cooling pipe 140, the air cooling jackets 142 and 144, and the refrigerant supply sources 146 and 148 are the second temperature adjusting means. The second transport roller 20b and the third transport roller 120b correspond to the transport means.

  In the heat treatment furnace 110 of the second embodiment described above, the same effect can be obtained by the same configuration as that of the first embodiment. For example, by setting the gap height H of the conveyance path 111c to 35 mm or less, it becomes easy to increase the temperature difference between the second and third spaces 11b and 111b, and the rapid temperature drop corresponding to more types of workpieces 96 is achieved. Is possible. In addition, by setting the gap height H to 25 mm or more, a gap through which the workpiece 96 and the setter 95 pass can be sufficiently secured. Furthermore, by setting the conveyance direction length L of the conveyance path 111c to be three times or more the gap height H, it becomes easy to increase the temperature difference between the atmosphere in the second space 11b and the atmosphere in the third space 111b.

  Furthermore, the upper end portions 138a and 138b of the lower partition wall 135 are positioned between the plurality of third transport rollers 120b in the transport direction and are positioned at the same height as the lower ends of the plurality of third transport rollers 120b in the vertical direction. ing. Therefore, the upper and lower gaps between the lower end of the third transport roller 120b and the lower partition 135 when the transport path 111c is viewed along the transport direction can be eliminated.

  Furthermore, the lower partition 135 has convex portions 137a and 137b having upper end portions 138a and 138b, and the convex portions 137a and 137b have a width in the transport direction toward the upper end portions 138a and 138b in the vertical direction. It has a smaller shape. Therefore, when the lower partition wall 135 is thermally expanded while the upper end portions 138a and 138b of the lower partition wall 135 are disposed between the plurality of third transport rollers 120b in the transport direction, the third transport roller 120b and the lower partition wall 135 (particularly It becomes easy to avoid contact with the convex portions 137a and 137b).

  Furthermore, the setter 95 is made of the same physical properties as in the first embodiment (at room temperature, the bending strength is 100 MPa to 250 MPa, the Young's modulus is 200 GPa to 350 GPa, the thermal expansion coefficient is 4 ppm / K to 5 ppm / K, the thermal conductivity. 50 W / mK to 200 W / mK), the heat resistance and the temperature follow-up performance with respect to the temperature difference of the temperature drop and the temperature drop rate when the setter 95 passes through the second space 11b, the conveyance path 111c, and the third space 111b. It will be enough. For example, the heat resistance and temperature followability of the setter 95 are sufficient at a temperature decrease rate in the range of 150 ° C./min to 1000 ° C./min as with the temperature increase rate.

  It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that the present invention can be implemented in various modes as long as it belongs to the technical scope of the present invention.

  For example, in the above-described embodiment, the upper end portions 38a and 38b are positioned at the same height as the lower end of the variable speed conveyance roller 20c, but the upper end portions 38a and 38b are above the lower end of the variable speed conveyance roller 20c. May be located. The same applies to the upper end portions 138a and 138b of the second embodiment.

  In the above-described embodiment, the convex portions 37a and 37b are formed such that the cross section perpendicular to the left-right direction is a triangle and the width in the front-rear direction becomes smaller toward the upper side in the vertical direction. As in the case, the width in the front-rear direction is not limited continuously as it goes upward in the vertical direction, but it may be reduced as a step function. For example, the convex portions 37a and 37b may have stepped cross sections perpendicular to the left-right direction. The convex portions 37a and 37b are not limited to those whose width in the front-rear direction becomes smaller toward the upper side in the vertical direction. Also in this case, if the width in the conveyance direction of the convex portions 37a and 37b is made smaller than the interval in the conveyance direction of the variable speed conveyance roller 20c, the upper end portion of the lower partition wall 35 is disposed between the variable speed conveyance rollers 20c and It can arrange | position to the height beyond the lower end of the variable speed conveyance roller 20c. The same applies to the convex portions 137a and 137b of the second embodiment.

  In the embodiment described above, the first and second spaces 11a and 11b are heated by the first and second heaters 21a and 21b. However, the first and second spaces 11a and 11b may be heated. Other heating means may be used. For example, a gas burner or the like may be used instead of the heater. Alternatively, the first and second spaces 11a and 11b may be heated with this atmospheric gas, as a high temperature atmosphere is supplied from the gas supply devices 22 and 24.

In the above-described embodiment, the atmosphere of the second space 11b partitioned by the partition wall portion 30 is set to a temperature higher than that of the first space 11a, but is not limited thereto. It is only necessary that the temperature of the atmosphere in the first space and the atmosphere in the second space partitioned by the partition walls be different. Further, the means for heating the space and the means for cooling the space may be combined in any way as long as the temperatures of the atmospheres of the two spaces partitioned by the partition walls are made different.

  In the second embodiment described above, the temperature drop between the second space 11b and the third space 111b partitioned by the partition wall 130 is performed to rapidly cool the workpiece 96 after firing. However, the present invention is not limited to this. Absent. For example, the temperature of the object to be processed 96 after baking may be rapidly lowered after annealing (for example, heat treatment at 1000 ° C.). That is, the space in which the annealing process is performed is defined as the first space of the present invention, the space where the workpiece 96 is transported next is defined as the second space of the present invention, and both spaces are partitioned by the partition wall 130. The space may be adjusted to a temperature lower than that of the first space, and the temperature may be rapidly lowered after annealing of the workpiece.

  In the second embodiment described above, the workpiece 96 is transported in the transport path 111c using the third transport roller 120b instead of the variable speed transport roller. However, similarly to the transport path 11c, the variable speed transport is performed. You may convey with a roller. By so doing, the temperature drop rate of the rapid temperature drop can be changed according to the transfer speed in the transfer passage 111c, and the rapid temperature drop corresponding to more types of objects to be processed 96 becomes possible.

  In the above-described embodiment, the partition walls 30 and 130 partition the two spaces in the furnace body. However, the partition walls similar to the partition walls 30 and 130 are also arranged at positions serving as the entrance and exit of the furnace body. May be. That is, a partition wall similar to the partition walls 30 and 130 may partition the space inside the furnace from the external space.

[Example 1]
As the heat treatment furnace of Example 1, the heat treatment furnace 10 shown in FIGS. The heat treatment furnace 10 had a gap height H of 30.0 mm and a conveyance direction length L of 100 mm. Further, the length in the left-right direction of the transport passage 11c is 700 mm. Moreover, the variable speed area | region of the variable speed conveyance roller 20c was 90 mm / min-600 mm / min.

[Comparative Example 1]
A heat treatment furnace 10 similar to that of Example 1 was prepared except that the gap height H was 36 mm and the conveyance direction length L was 50 mm, and Comparative Example 1 was obtained.

[Example 2]
As the heat treatment furnace of Example 2, the heat treatment furnace 110 shown in FIG. In the heat treatment furnace 110, the gap height H of the transfer passage 111c was 30.0 mm, and the length L in the transfer direction was 100 mm. Further, the length of the conveyance path 111c in the left-right direction is set to 700 mm.

  In the heat treatment furnace 10 of Example 1, the atmospheres of the first and second spaces 11a and 11b were changed to nitrogen atmospheres by the gas supply devices 22 and 24. Thereafter, there was no supply of gas from the gas supply devices 22 and 24 and no outflow of gas from the flow rate adjustment valve 26 and the flow rate adjustment valve 28. In this state, the temperature of the first space 11a during heat treatment (target temperature) is set to 700 ° C., the temperature of the second space 11b (target temperature) is set to 1200 ° C., and the controller 80 outputs the first and second heaters 21a and 21b. As a result, the temperature of any atmosphere in the first and second spaces 11a and 11b could be adjusted to the target temperature. Note that the temperatures of the atmospheres in the first and second spaces 11a and 11b were both measured at the center of the space.

In the heat treatment furnace 10 of Comparative Example 1, the atmospheres of the first and second spaces 11a and 11b were made nitrogen atmosphere by the gas supply devices 22 and 24. Thereafter, there was no supply of gas from the gas supply devices 22 and 24 and no outflow of gas from the flow rate adjustment valve 26 and the flow rate adjustment valve 28. In this state, the temperature (target temperature) of the first space 11a during the heat treatment is set to 800 ° C., and the second space 11b.
The output of the first and second heaters 21 a and 21 b was controlled by the controller 80 with the temperature (target temperature) of 1200 ° C. being set. Although the temperature of the second space 11b could be adjusted to the target temperature of 1200 ° C, the temperature of the first space 11a was only 900 ° C even when the output of the first heater 21a was 0%, and the target temperature was 800 ° C. did not become. That is, in Comparative Example 1, the temperature difference between the first and second spaces 11a and 11b did not exceed 300 ° C.

  In the heat treatment furnace 110 of Example 2, the atmospheres of the second and third spaces 11b and 111b were changed to nitrogen atmosphere by the gas supply devices 24 and 124. Thereafter, there was no supply of gas from the gas supply devices 24 and 124 and no outflow of gas from the flow rate adjustment valves 28 and 128. In this state, the temperature (target temperature) of the second space 11b during heat treatment is set to 1000 ° C., and the temperature (target temperature) of the third space 111b is set to 300 ° C., and the output of the second heater 21b and the cooling pipe 140 and The flow rate and temperature of the air passing through the air cooling jackets 142 and 144 were controlled. As a result, the temperature of any atmosphere in the second and third spaces 11b and 111b could be adjusted to the target temperature. In addition, the temperature of the atmosphere in the second and third spaces 11b and 111b was the temperature measured at the center of the space.

  From the above, in Example 1, the gap height H is 25 mm or more and 35 mm or less, and the conveyance direction length L is three times or more of the gap height H, whereby the temperature difference between the first and second spaces 11a and 11b. Is considered to be 500 ° C., which is larger than that of Comparative Example 1.

  In the second embodiment, the gap height H is 25 mm or more and 35 mm or less, and the conveyance direction length L is three times or more of the gap height H, so that the temperature difference between the second and third spaces 11b and 111b is 700. It is considered that the temperature can be raised to ° C.

  In the heat treatment furnace 10 of the first embodiment, the setter 95 on which the workpiece 96 is placed is opened 14 with the temperature of the first space 11a during the heat treatment adjusted to 700 ° C. and the temperature of the second space 11b adjusted to 1200 ° C. To the opening 15. At this time, the conveyance speed when passing through the conveyance passage 11c and the temperature increase rate of the workpiece 96 were measured. Specifically, the setter 95 is a setter made of Si-bonded SiC and has a longitudinal length (conveyance direction length) of 250 mm, a lateral length of 250 mm, and a thickness of 4 mm. The setter 95 had physical properties at room temperature of a bending strength of 250 MPa, a Young's modulus of 350 GPa, a thermal expansion coefficient of 4.5 ppm / K, and a thermal conductivity of 150 W / mK. The workpiece 96 is to be a ceramic capacitor chip after firing, and is placed at the center of the upper surface of the setter 95. Moreover, the non-contact sensor which detects the setter 95 was arrange | positioned in the furnace body 10a in the position 100 mm away from the partition part 30 upstream in the conveyance direction, and the position 150 mm away from the partition part 30 downstream in the conveyance direction. When the setter 95 is transported and the upstream sensor detects the setter 95 (= when the downstream end of the setter 95 comes to a position 100 mm away from the partition wall 30 upstream in the transport direction), the downstream sensor Measured the temperature and time of the workpiece 96 at two points when the setter 95 was detected (= the downstream end of the setter 95 came to a position 150 mm away from the partition wall 30 downstream in the transport direction). From the temperature difference and time difference of the workpiece 96 at these two points, the temperature increase rate of the workpiece 96 was calculated. Such a temperature increase rate was calculated a plurality of times by changing the conveyance speed of the variable speed conveyance roller 20c. When the temperature increase rate was measured several times while changing the conveyance speed of the variable speed conveyance roller 20c in the range of 100 mm / min to 600 mm / min, the temperature increase rate of the workpiece 96 was in the range of 167 ° C./min to 1000 ° C./min. It was changing. In addition, the same setter 95 was used for all measurements, but no cracks or the like occurred.

  10, 110 heat treatment furnace, 10a, 110a furnace body, 11, 111 outer wall, 11a, 11b first and second spaces, 11c, 111c transport passage, 12 front end face, 13, 113 rear end face, 14, 15, 115 opening, 16, 17, 117 Gas supply port, 18, 19, 119 Outlet, 20a, 20b First and second transport rollers, 20c Variable speed transport roller, 21a, 21b First, second heater, 22, 24, 124 Gas Supply device, 26, 28, 128 Flow control valve, 30, 130 Partition, 31, 131 Upper partition, 32, 132 Body, 33, 133 Beam, 35, 135 Lower partition, 36, 136 Body, 37a, 37b , 137a, 137b Convex part, 38a, 38b, 138a, 138b Upper end part, 80 controller, 81 CPU, 8 Flash memory, 83 correspondence data, 84 RAM, 85 speed acquisition unit, 86 transport control unit, 88 operation panel, 95 setter, 96 workpiece, 111b third space, 120b third transport roller 140 cooling pipe, 142, 144 Air cooling jacket, 146, 148 Refrigerant supply source.

A plurality (eight in this embodiment) of first transport rollers 20a are disposed along the predetermined transport direction in the first space 11a, and are transport rollers that transport the setter 95. In the present embodiment, the conveyance direction of the first conveying roller 20 a is a horizontal direction, and a direction from the front to the rear (toward the right side from the left side of FIG. 1). As the first transport roller 20a rotates, the setter 95 on which a plurality of objects to be processed 96 are placed is transported from the opening 14 in the first space 11a in the transport direction.

The controller 80 is configured as a microprocessor centered on a CPU 81, and communicates with a flash memory 82 that stores various processing programs and various data, a RAM 84 that temporarily stores data, an operation panel 88, and the like. Internal communication interface (I / F). The flash memory 82 stores correspondence data 83. Correspondence relationship data 83 represents a correspondence relationship between the temperatures of the first and second spaces 11a and 11b , the temperature increase rate when the setter 95 passes through the transport path 11c, and the transport speed of the variable speed transport roller 20c. It is data.

In the heat treatment furnace 10 of the first embodiment described above, the atmosphere of the first space 11a is heated by the first heater 21a, and the atmosphere of the second space 11b is heated to a higher temperature than the first space 11a by the second heater 21b. The workpiece 96 conveyed in the first space 11a by the first conveying roller 20a while being heated to a variable speed region that is faster than the first and second conveying rollers 20a, 20b by the variable speed conveying roller 20c. It passes through the inside of the transport passage 11c at a predetermined speed and is transported to the second transport roller 20b. As a result, the workpiece 96 is rapidly heated from the first space 11a through the transfer passage 11c and transferred to the high temperature second space 11b at high speed. The temperature rising speed at this time changes according to the conveying speed in the conveying passage 11c, but this conveying speed can be changed within the range of the variable speed region. Therefore, the temperature increase rate can be changed according to the object to be processed 96, and rapid temperature increase corresponding to various objects to be processed 96 becomes possible. Incidentally, a suitable heating rate in the case of rapidly raising the temperature of the object to be processed 96 varies depending on the size of the material and the object to be treated 96 included in the processing object 96. For example, if the rate of temperature increase is too low, cracking or peeling may occur due to a difference in shrinkage between different materials in the workpiece 96. In addition, if the temperature raising rate is too high, only the surface of the workpiece 96 may be fired first, and firing may be non-uniform. In the heat treatment furnace 10 of the first embodiment, this can be suppressed and rapid temperature increase corresponding to various objects to be processed 96 can be achieved.

The partition wall portion 130 includes an upper partition wall 131 including a main body portion 132 and a beam 133, and a lower partition wall 135 including a main body portion 136 and convex portions 137a and 137b (a broken line frame S2 illustrated on the left side in FIG. 4). (See the enlarged part). The convex portions 137a and 137b are provided with upper end portions 138a and 138b which are top portions. The partition wall portion 30 is the partition wall portion 30 except that the second space 11b and the third space 111b are partitioned, and the third transport roller 120b is disposed in the transport path 111c instead of the variable speed transport roller 20c. It is the same composition as.

Claims (12)

A heat treatment furnace for performing heat treatment of a workpiece,
The first space, the second space, a passage that communicates the first space and the second space and conveys the object to be processed, and has a vertical gap height H of 25 mm or more and 35 mm or less. And a furnace body having a partition wall that partitions the first space and the second space,
Temperature adjusting means for differentiating the temperature of the atmosphere of the first space and the atmosphere of the second space;
Transport means for transporting the object to be processed in the order of the first space, the transport path, and the second space;
Heat treatment furnace equipped with. The conveyance path length L of the conveyance path is at least three times the gap height H.
The heat treatment furnace according to claim 1. The conveying means is
First conveying means for conveying the object to be processed in the first space;
Second transport means for transporting the object to be processed in the second space;
The object to be processed conveyed to the first conveying means is conveyed to the second conveying means through the conveying path in a predetermined conveying direction, and more than the first conveying means and the second conveying means. Variable speed transport means capable of changing the speed of the transport within a high speed variable speed region;
The heat treatment furnace according to claim 1 or 2. The transport means has a plurality of transport rollers for transporting the object to be processed in a horizontal direction which is a transport direction in the transport passage,
The partition has an upper partition located vertically above the transport passage, and a lower partition located vertically below the transport passage,
One or more upper ends of the lower partition wall are positioned between the plurality of transport rollers in the transport direction, and are positioned above or above the lower ends of the plurality of transport rollers in the vertical direction;
The heat treatment furnace according to any one of claims 1 to 3. The lower partition wall has one or more convex portions having the upper end portion, and the convex portion has a shape in which the width in the transport direction becomes smaller toward the upper end portion in the vertical direction.
The heat treatment furnace according to claim 4. A first passage, a second space, a passage that communicates the first space and the second space and conveys an object to be processed, and a conveyance passage having a vertical gap height H of 25 mm or more and 35 mm or less. A heat treatment method for the object to be treated in a heat treatment furnace comprising a furnace body having a partition wall formed and partitioning the first space and the second space,
The step of transporting the object to be processed in the order of the first space, the transport path, and the second space in a state where the atmosphere of the first space and the atmosphere of the second space are different. ,
A heat treatment method comprising: The conveyance path length L of the conveyance path is at least three times the gap height H.
The heat treatment method according to claim 6. The heat treatment furnace
First conveying means for conveying the object to be processed in the first space;
Second transport means for transporting the object to be processed in the second space;
The object to be processed conveyed to the first conveying means is conveyed to the second conveying means through the conveying path in a predetermined conveying direction, and more than the first conveying means and the second conveying means. Variable speed transfer means capable of changing the speed of the transfer in a high speed variable speed area;
With
In the step, an object to be processed transported in the first space by the first transport means in a state where the temperature of the atmosphere of the first space and the atmosphere of the second space are different from each other is changed to the variable speed. Transporting the transport path to the second transport means by passing through the transport path at a predetermined speed in the variable speed region by the transport means;
The heat treatment method according to claim 6 or 7. The variable speed region is a region determined so that the temperature change rate of the workpiece when passing through the transport passage can be changed in a range of at least 150 ° C./min to 1000 ° C./min,
In the step, the object to be processed is transported in a state of being placed on a setter,
The setters each have physical properties at room temperature, bending strength of 100 MPa to 250 MPa, Young's modulus of 200 GPa to 350 GPa, thermal expansion coefficient of 4 ppm / K to 5 ppm / K, and thermal conductivity of 50 W / mK to 200 W / mK. is there,
The heat treatment method according to claim 8. The setter is made of Si-bonded SiC or recrystallized SiC.
The heat treatment method according to claim 9. The transport means has a plurality of transport rollers for transporting the object to be processed in a horizontal direction which is a transport direction in the transport passage,
The partition has an upper partition located vertically above the transport passage, and a lower partition located vertically below the transport passage,
One or more upper ends of the lower partition wall are positioned between the plurality of transport rollers in the transport direction, and are positioned above or above the lower ends of the plurality of transport rollers in the vertical direction;
The heat processing method of any one of Claims 6-10. The lower partition wall has one or more convex portions having the upper end portion, and the convex portion has a shape in which the width in the transport direction becomes smaller toward the upper end portion in the vertical direction.
The heat treatment method according to claim 11.

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