Heat treatment apparatus

Abstract

To provide a heat treatment apparatus which can suppress the generation of dew condensation even when a heating chamber is in a high temperature and high dew point environment, and can realize the same even without adopting a special, expensive, high-performance wall material.SOLUTION: A heat treatment apparatus 10 comprises a heating chamber 12 made into a high temperature and a high dew point for heat-treating a workpiece W. The heat treatment apparatus 10 comprises: a heating furnace 11 having a heat insulation material 31 for heat-insulating the heating chamber 12 and an outer shell 32 covering the outside of the heat insulation material 31 and making the passage of gases impossible; a terminal part 41 located outside the outer shell 32; a penetration part 42 penetrating the outer shell 32 and the heat insulation material 31; a heater 13 having a heat generation part 43 located in the heating chamber 12; and a warming part 14 for increasing the temperature of the outer shell 32.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a heat treatment apparatus. [Background technology]

[0002] A heat treatment apparatus is used to heat-treat a workpiece. For example, as disclosed in Patent Document 1, the heat treatment apparatus has a heating furnace, and the heating furnace has a heat insulating material for insulating a heating chamber and an outer shell that covers the heat insulating material. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 62-253714 Summary of the Invention [Problem to be solved by the invention]

[0004] In the case of the heat treatment device disclosed in Patent Document 1, the workpiece is a steel material, and the device is configured to improve the descaling properties of the steel material by performing heat treatment. Various workpieces are heat treated, and the environment of the heating chamber is set depending on the type and purpose of the workpiece.

[0005] For example, when electronic components such as multilayer ceramic capacitors are reoxidized (heat treated), the heating chamber is set to an atmosphere with a high temperature and a high dew point. The heating furnace disclosed in Patent Document 1 has a heat insulating material and an outer shell that covers the outside of the heat insulating material. When such a conventional heating furnace is used to heat treat a workpiece in a high-temperature, high-dew-point atmosphere, the following problems arise.

[0006] There is a large temperature difference between the inside and outside of the heating furnace, which becomes very hot. The insulating material is made of, for example, a high-density fibrous material. While this type of ordinary insulating material provides high insulation, it is not airtight and allows gas to pass through. Therefore, when the atmosphere in the heating chamber has a particularly high dew point (high humidity), condensation is likely to occur on the outer wall (the outer shell) of the heating furnace and its surroundings. Condensation can adversely affect electrical components, such as heaters and sensors, installed in the heating furnace.

[0007] Here, if a high-performance wall material that can withstand high temperature and high dew point environments is used in the heating furnace, it may be possible to solve the above problem. However, such high-performance wall materials are special and expensive compared to heat insulating materials made of high-density fibrous bodies, and therefore are unlikely to be adopted in actual heat treatment equipment.

[0008] Therefore, an object of the present invention is to provide a heat treatment apparatus that can suppress the occurrence of condensation even when the heating chamber is in a high temperature and high dew point environment, and that can achieve this without employing special, expensive, high-performance wall materials. [Means for solving the problem]

[0009] The present invention is a heat treatment apparatus having a heating chamber that is heated to a high temperature and a high dew point for heat treatment of a workpiece, and includes a heating furnace having an insulating material for insulating the heating chamber and an outer shell that covers the outside of the insulating material and prevents gas from passing through, a heater having a terminal portion located on the outside of the outer shell, a penetration portion that penetrates the outer shell and the insulating material, and a heat generating portion located in the heating chamber, and a heating portion for raising the temperature of the outer shell. [Effects of the Invention]

[0010] According to the heat treatment device of the present invention, even if the heating chamber is in a high temperature and high dew point environment, the occurrence of condensation can be suppressed by the heating section, and this can be achieved without employing special, expensive, high-performance wall materials. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram showing the configuration of an embodiment of a heat treatment apparatus according to the present invention. [Figure 2] FIG. 2 is a perspective view of the heating furnace. [Figure 3] FIG. 3 is a perspective view of the heating furnace as seen from another direction. [Figure 4] FIG. 4 is an explanatory diagram of the hot air supply device. [Figure 5] FIG. 5 is a perspective view of the outer case. [Figure 6] FIG. 6 is an explanatory diagram of the outer case and the heating furnace inside it. [Figure 7] FIG. 7 is a cross-sectional view taken along the line VII in FIG. [Figure 8] FIG. 8 is an explanatory diagram of the outer case and the heating furnace inside it. [Figure 9] FIG. 9 is a cross-sectional view taken along the line IX in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] <Outline of the embodiment of the present invention> Hereinafter, an outline of an embodiment of the present invention will be listed and described. (1) The present invention is a heat treatment apparatus having a heating chamber that is heated to a high temperature and a high dew point for heat treatment of a workpiece, and includes a heating furnace having an insulating material for insulating the heating chamber and an outer shell that covers the outside of the insulating material and prevents gas from passing through, a heater having a terminal portion located on the outside of the outer shell, a penetration portion that penetrates the outer shell and the insulating material, and a heat generating portion located in the heating chamber, and a heating portion for increasing the temperature of the outer shell.

[0013] Even if the insulation is not airtight enough to allow gas to pass through, the outer shell covers the insulation, preventing the gas from passing through. This prevents the high-temperature, high-dew-point gas in the heating chamber from leaking outside, maintaining a high-temperature, high-dew-point state. When the inside of the heating furnace (heating chamber) is hot and has a high dew point, while the temperature outside the heating furnace is low, condensation is likely to occur on the outer shell. Therefore, even if the heating chamber is in a high dew point environment, the heating unit can increase the temperature of the outer shell, thereby making it possible to suppress condensation on the outer shell. As the heat insulating material, it is possible to use a commonly used normal heat insulating material such as a high density fiber material.

[0014] (2) In the heat treatment device of (1), the heating unit has an outer case that covers the heating furnace and is spaced apart from the heating furnace, and a hot air supply device that supplies hot air to the space formed between the heating furnace and the outer case. According to the above configuration, it becomes easy to increase the temperature of the outer shell of the heating furnace over a wide range.

[0015] (3) The heat treatment apparatus according to (1) or (2) above further comprises a humidified gas supply unit having a humidifier and supplying gas humidified by the humidifier to the heating chamber. With this configuration, the heating chamber becomes a high dew point environment, and the workpiece is heat-treated in this environment. Since the heating chamber has a high dew point, condensation is likely to occur on the outer shell, but the heating section increases the temperature of the outer shell, making it possible to suppress condensation.

[0016] (4) In the heat treatment device of (2), the heating furnace has a furnace body having the heating chamber inside, a first door attached to the furnace body and capable of being opened and closed to load and unload the workpiece, and a seal provided between the furnace body and the first door, and the outer case has a case body located outside the furnace body at a distance from the furnace body, and a second door attached to the case body and capable of being opened and closed to load and unload the workpiece, and a seal guide that guides the hot air toward the seal is provided in the space between the heating furnace and the outer case.

[0017] The temperature inside the heating furnace (heating chamber) is high. It is necessary to lower the temperature of the seal between the furnace body and the first door in the heating furnace to prevent it from deteriorating due to heat. Because the heating furnace is covered by an outer case, it is not easy to lower the temperature of the seal. However, with the above-described configuration, the hot air (which is significantly cooler than the temperature of the heating chamber) passing through the space between the heating furnace and the outer case is guided around the seal by the seal guide. This makes it difficult for heat to build up around the seal, making it possible to lower the temperature of the seal.

[0018] (5) In the heat treatment device of (4), the furnace body has a furnace wall having an opening through which the first door closes, the seal is annularly arranged to surround the opening, and the seal guide has an elongated shape along the longitudinal direction of the seal. In this case, the hot air passing through the space between the heating furnace and the outer case flows along the longitudinal direction of the seal due to the seal guide, making it possible to lower the temperature of the seal over a wide range.

[0019] (6) In the heat treatment device of (4) or (5), the second door has a door insulation material and a door covering material that covers the door insulation material, and the case body is made of a plate member with exposed inner and outer surfaces. The second door is frequently touched by workers when opening and closing it, so it has door insulation to prevent the temperature of its outer surface from becoming too high. Since workers usually touch the second door but rarely touch the case body during normal work, and the temperature of the outer surface of the case body is unlikely to become too high due to the space between the heating furnace and the outer case, insulation for the case body can be omitted.

[0020] (7) In any one of the heat treatment devices (2), (4) to (6), the terminal portion is located in the space, and a terminal guide is provided in the space to guide the hot air toward the terminal portion. When the heater is disposed through the outer shell and the insulation, and the temperature outside the heating furnace is low, condensation is likely to occur at and around the terminals located outside the outer shell of the heating furnace, making it necessary to raise the temperature of the terminals. Furthermore, because electric wires may be connected to the terminals, it is not easy to guide warm air to the terminals. However, with the above configuration, warm air passing through the space between the heating furnace and the outer case is guided toward the periphery of the terminals by the terminal guide. Therefore, by raising the temperature of the terminals and their surroundings, condensation at and around the terminals can be suppressed. Furthermore, electrical leakage at the terminals due to water condensation can also be suppressed.

[0021] (8) In any one of the heat treatment devices (2), (4) to (6), the outer case has a plurality of case outer walls facing different directions, and the hot air supply device has a plurality of pipes for supplying hot air to the space between each of the plurality of case outer walls and the outer shell. Warm air is supplied from multiple locations to the space between the heating furnace and the outer case. The warm air passes through the space between the heating furnace and the outer case, making it possible to increase the temperature of the outer shell, but also making it difficult for a temperature difference to occur in the space.

[0022] <Details of the embodiment of the present invention> Hereinafter, the details of the embodiments of the present invention will be described. [Overall configuration of heat treatment device] FIG. 1 is a configuration diagram showing one embodiment of a heat treatment apparatus of the present invention. The heat treatment apparatus 10 is an apparatus for heat treating a workpiece W. The heat treatment apparatus 10 heat treats various components (workpiece W), but in this embodiment, the workpiece W is an electronic component, particularly a multilayer ceramic capacitor. The heat treatment apparatus 10 performs a reoxidation treatment on the workpiece W as heat treatment.

[0023] The heat treatment apparatus 10 has a heating chamber 12 that accommodates workpieces W. A plurality of workpieces W are placed in a container 29, and the container 29 is placed on a table 28 installed in the heating chamber 12. Fig. 1 shows a cross section of a heating furnace 11 that has the heating chamber 12 therein and an outer case 51, which will be described later. The heating chamber 12 is heated to a high temperature and a high dew point by the heater 13 and the humidified gas supply unit 15, which will be described later. Moreover, this high temperature and high dew point state continues for a long period of time (for example, 10 hours). The temperature of the heating chamber 12 is, for example, 800°C or higher and 1300°C or lower, and the dew point of the heating chamber 12 is 40°C or higher and 70°C or lower. Note that the temperature and dew point values ​​are merely examples and are not limited to these.

[0024] The heat treatment apparatus 10 includes a heating furnace 11, a heater 13, a heating unit 14, a humidified gas supply unit 15, a treatment gas supply unit 16, a temperature sensor 17, a dew point sensor 18, an oxygen concentration sensor 19, a hydrogen concentration sensor 20, and a control device 21. Each of these components will be described below in order.

[0025] [About heating furnace 11] The heating furnace 11 has a heat insulating material 31 for insulating the heating chamber 12 and an outer shell 32 that covers the outside of the heat insulating material 31. The heat insulating material 31 is configured to have a high density fibrous body using, for example, ceramic fiber, etc. This heat insulating material 31 has a high heat insulating effect, but is not airtight and allows gas to pass through. The outer shell 32 is made of a material that does not allow gas to pass through. The outer shell 32 is made of a heat-resistant steel plate such as stainless steel. The outer shell 32 is laminated on the heat insulating material 31, and the outer shell 32 and the heat insulating material 31 are integrated.

[0026] FIG. 2 is a perspective view of the heating furnace 11. FIG. 3 is a perspective view of the heating furnace 11 viewed from another direction. The heating furnace 11 has a rectangular parallelepiped shape. The heating furnace 11 has a furnace body 33 with the heating chamber 12 inside, and a first door 34. The first door 34 is attached to the furnace body 33 and can be opened and closed by a hinge 341 to load and unload the workpiece W. For the sake of explanation, FIG. 3 shows the first door 34 removed.

[0027] The furnace body 33 has six furnace walls 331, one above the other, left and right, front and rear. One of the furnace walls 331 (the front) has an opening 332. The furnace body 33 has the furnace wall 331 with the opening 332, and the opening 332 is closed by a first door 34. Each furnace wall 331 is configured to have a wall-shaped insulating material 31 and an outer shell 32 that covers the insulating material 31. The first door 34 also has an insulating material 31 and an outer shell 32 that covers the insulating material 31.

[0028] The heating furnace 11 has a seal 35 provided between the furnace body 33 and the first door 34. The seal 35 prevents high-temperature, high-dew-point gas in the heating chamber 12 from leaking out. The seal 35 is provided in a ring shape surrounding the opening 332. The seal 35 is made of a material such as heat-resistant silicone rubber and has the ability to withstand high temperatures. However, to prevent deterioration over long-term use, the heat treatment device 10 has a structure for lowering the temperature of the seal 35 (seal guide 36, see FIG. 6). The structure for lowering the temperature of the seal 35 will be described later.

[0029] [About heater 13] The heater 13 heats the gas in the heating chamber 12. In this embodiment, the heater 13 is provided in the heating furnace 11 in an upper and lower divided state. The upper heater unit has a plurality of heaters 13 (three in the case of FIG. 3), and the lower heater unit has a plurality of heaters 13 (three in the case of FIG. 3).

[0030] The heaters 13 are attached to the heating furnace 11 by penetrating the furnace wall 331 of the heating furnace 11. Each heater 13 is an electric heater such as a SiC heater (silicon carbide heating element), and has a terminal portion 41, a penetration portion 42 that penetrates the outer shell 32 and the heat insulating material 31, and a heat generating portion 43 that becomes high temperature. The terminal portion 41 is located outside the outer shell 32 (see FIG. 2). The heat generating portion 43 is located in the heating chamber 12 (see FIG. 3). The penetration portion 42 may generate heat, just like the heat generating portion 43.

[0031] [About the heating unit 14] The heating unit 14 (see FIG. 1) has a configuration for increasing the temperature of the outer shell 32 of the heating furnace 11. The heating unit 14 increases the temperature of the outer shell 32 from outside the outer shell 32. As will be explained later, when the temperature inside the heating furnace 11 (heating chamber 12) is high and has a high dew point, while the temperature outside the heating furnace 11 is low, condensation is likely to occur on the outer shell 32. Therefore, even if the heating chamber 12 is in a high dew point environment, the heating unit 14 increases the temperature of the outer shell 32. This prevents condensation on the outer shell 32.

[0032] In this embodiment, the heating unit 14 is configured to include an outer case 51 that covers the heating furnace 11 (outer shell 32) at a distance from the heating furnace 11, and a hot air supply device 53. The outer case 51 is configured from a material that prevents gas from passing through. The outer case 51 is configured from a steel plate such as stainless steel. Like the heating furnace 11, the outer case 51 has a rectangular parallelepiped shape and surrounds the heating furnace 11 from all directions (six directions). However, as will be explained later, the outer case 51 has a second door 62 for loading and unloading the workpiece W (see FIG. 5).

[0033] The hot air supply device 53 (see FIG. 1) supplies hot air to a space 52 formed between the heating furnace 11 and the outer case 51. FIG. 4 is an explanatory diagram of the hot air supply device 53. In FIG. 4, the outer case 51 is shown with an imaginary line (two-dot chain line) to explain the space 52 between the heating furnace 11 and the outer case 51. The outer shell 32 of the heating furnace 11 is covered by the outer case 51 from above, below, left, right, front, and back, and the space 52 is provided on the above, below, left, right, front, and back of the outer shell 32 (heating furnace 11). The space 52 serves as a passage for the supplied hot air.

[0034] The hot air supply device 53 has a hot air generator 531 with an electric heater and hot air piping 532. The hot air generated by the hot air generator 531 is supplied to the space 52 through the hot air piping 532. In addition to Fig. 4, in Figs. 6 to 9, the flowing hot air is indicated by thin arrows.

[0035] The hot air generator 531 is controlled by the control device 21, and the temperature of the hot air to be generated is adjusted. The hot air generator 531 heats room temperature air to generate hot air. The temperature of the hot air is higher than room temperature but sufficiently lower than the temperature of the heating chamber 12. The temperature of the hot air emitted from the hot air generator 531 is 100°C or lower, and is, for example, 50°C or higher and 70°C or lower, which is a temperature near 60°C when the dew point temperature of the atmosphere in the heating chamber 12 is 60°C. The hot air supplied to the space 52 is dry air and has a lower humidity (lower dew point) than the gas in the heating chamber 12. The temperature of the hot air is set according to the dew point temperature of the heating chamber 12, and is set to a temperature near the dew point temperature (+ / - 10°C), for example.

[0036] In the embodiment shown in Fig. 4, the hot air piping 532 is a circulating piping connected to the space 52. The hot air generator 531 is provided midway along the hot air piping 532. An outside air exchange unit 533, which is composed of an intake / exhaust four-way damper or the like, is provided midway along the hot air piping 532. The outside air exchange unit 533 can take in outside air, and sends the outside air to the hot air generator 531. The outside air exchange unit 533 has an exhaust function and can discharge a portion of the hot air that has passed through the space 52.

[0037] As described above, the outer case 51 has a rectangular parallelepiped shape and has six case outer walls 511. In the present embodiment, one of the six case outer walls 511 serves as the second door 62. Hot air piping 532 is connected to the area between a plurality (two or three) of the six case outer walls 511 and the outer shell 32 of the heating furnace 11. In the embodiment shown in FIG. 4, a branch pipe 532A of the hot air piping 532 is connected to the area between the right case outer wall 511 and the opposing outer shell 32. A branch pipe 532B of the hot air piping 532 is connected to the area between the front case outer wall 511 (second door 62) and the opposing outer shell 32 (first door 34).

[0038] In this way, outer case 51 has a plurality of case outer walls 511 facing in different directions. Hot air supply device 53 supplies hot air to space 52 between each of these plurality of case outer walls 511 and outer shell 32. In order to supply hot air to space 52 from a plurality of locations, hot air supply device 53 has branch pipes 532A and 532B as a plurality of piping.

[0039] The outer case 51 covers the entire outer shell 32, and the spaces 52 are formed above, below, left, right, front, and back of the outer shell 32. Air is supplied to the spaces 52. This configuration makes it easy to increase the temperature of the outer shell 32 over a wide area. The warm air is supplied to the space 52 from multiple pipes (branch pipes 532A, 532B). This makes it difficult for temperature differences to occur in the space 52.

[0040] As described above, the outer case 51 has a rectangular parallelepiped shape (see FIG. 5). FIG. 5 is a perspective view of the outer case 51. Note that the hot air piping 532 has been omitted from FIG. 5 for ease of explanation. The outer case 51 has a case body 61 and a second door 62 attached to the case body 61. The second door 62 can be opened and closed by a hinge 621 to load and unload the workpiece W. The case body 61 is located outside the furnace body 33 (outer shell 32) with a gap therebetween.

[0041] The front of the case body 61 is an opening 512, and the opening 512 is closed by a second door 62. The second door 62 faces the first door . The second door 62 is often touched by workers when opening and closing it. For this reason, the second door 62 has a door insulating material 63 and a door covering material 64 that covers the door insulating material 63 from the outside. The space 52 between the heating furnace 11 and the outer case 51 prevents the temperature of the outer surface of the second door 62 from becoming high, but the second door 62 has door insulation 63 to further suppress the rise in temperature of the outer surface.

[0042] During normal work, workers rarely have the opportunity to touch the case body 61. Furthermore, the space 52 prevents the temperature of the outer surface of the case body 61 from becoming too high. Therefore, in this embodiment, the case body 61 does not require a heat insulating material. In other words, the case body 61 does not have a heat insulating material and is made of a plate member with exposed inner and outer surfaces.

[0043] [Regarding the processing gas supply unit 16 and the humidified gas supply unit 15] The process gas supply unit 16 (see FIG. 1) supplies gases (process gases) used in heat treatment to the heating chamber 12. In this embodiment, the gases are hydrogen gas and nitrogen gas. The process gas supply unit 16 has a hydrogen gas source (tank) 81, a flow rate control valve 82, an on-off valve 83, and a pipe 87. The process gas supply unit 16 has a nitrogen gas source (tank) 84, a flow rate control valve 85, an on-off valve 86, and a pipe 88. The hydrogen gas is supplied to the heating chamber 12 through the pipe 87. The nitrogen gas is supplied to the heating chamber 12 through the pipe 88.

[0044] The humidified gas supply unit 15 has a humidifier 71, a gas source (tank) 72 for the gas to be humidified, piping 75, a flow rate adjustment valve 73, and an on-off valve 74. In this embodiment, the gas to be humidified is nitrogen gas, which is one of the gases used in heat treatment. The flow rate adjustment valve 73 adjusts the outflow rate of the nitrogen gas. The humidified gas supply unit 15 supplies the gas humidified by the humidifier 71 to the heating chamber 12 through the piping 75. The gas supplied from the humidified gas supply unit 15 gives the heating chamber 12 a high dew point.

[0045] [Regarding various sensors and control devices 21] The temperature sensor 17 measures the temperature of the heating chamber 12. The dew point sensor 18 measures the humidity of the heating chamber 12. The oxygen concentration sensor 19 measures the oxygen concentration of the heating chamber 12. The hydrogen concentration sensor 20 measures the hydrogen concentration of the heating chamber 12. The measurement values ​​of these sensors are sent to the control device 21.

[0046] The control device 21 is configured with a computer. The control device 21 acquires signals (measurement values) from the various sensors and performs various processes according to the signals. The control device 21 controls the humidified gas supply unit 15 based on the measurement value of the dew point sensor 18, and executes control to adjust the humidification degree of the gas to be humidified and the flow rate of the gas to be supplied. The control device 21 controls the flow rate adjustment valves 82, 85 based on the measurement values ​​of the oxygen concentration sensor 19 and the hydrogen concentration sensor 20, and executes control to adjust the flow rate of the process gas to be supplied. The control device 21 executes control to adjust the output of the heater 13 based on the measurement value of the temperature sensor 17.

[0047] [Configuration for reducing the temperature of the seal 35] Fig. 6 is an explanatory diagram of the outer case 51 and the heating furnace 11 inside it. In Fig. 6, the outer case 51 is shown with an imaginary line (two-dot chain line) to explain the space 52 between the outer case 51 and the heating furnace 11. Fig. 7 is a cross-sectional view taken along arrow VII in Fig. 6. As described above, the seal 35 is provided between the furnace body 33 and the first door 34 of the heating furnace 11. A structure for lowering the temperature of the seal 35 is provided in the space 52. That is, a seal guide 36 is provided in the space 52.

[0048] The sealing guide 36 guides the hot air supplied by the hot air supply device 53 toward the seal 35. As shown in FIG. 6, the seal 35 is provided in an annular shape along the opening 332 provided in the furnace body 33. The sealing guide 36 has an elongated shape along the longitudinal direction of the seal 35. The sealing guide 36 is configured with a long plate-like member and is attached to the front furnace wall 331 of the furnace body 33 so as to be aligned with the first door 34 that closes the opening 332.

[0049] The sealing guides 36 are provided above the opening 332, below the opening 332, and on both the left and right sides of the opening 332. In other words, a plurality of sealing guides 36 (five in the illustrated example) are provided along the seal 35. The number of sealing guides 36 can be changed.

[0050] The sealing guides 36 have a shape that expands the gap E formed between adjacent sealing guides 36 in order to take in the hot air flowing along the furnace wall 331. In other words, the sealing guides 36 have an end 361 that curves in a direction away from the opening 332 on the upstream side of the hot air flow direction. This configuration of the sealing guides 36 allows the hot air to be taken in on the seal 35 side.

[0051] 7, the sealing guide 36 is positioned at a distance from the first door 34 when the opening 332 is closed. The warm air flowing through the space 52 can pass between the first door 34 and the sealing guide 36, and when the warm air collides with the sealing guide 36, the warm air changes direction and flows toward the gap between the first door 34 and the sealing guide 36.

[0052] Here, the temperature inside the heating furnace 11 (heating chamber 12) is high. In order to prevent the seal 35 between the furnace body 33 and the first door 34 in the heating furnace 11 from being deteriorated by heat, it is necessary to lower the temperature. Because the heating furnace 11 is covered by the outer case 51, it is not easy to lower the temperature of the seal 35. Therefore, as described above, the heat treatment apparatus 10 of this embodiment has the sealing guide 36. The hot air passing through the space 52 between the heating furnace 11 and the outer case 51 is guided by the sealing guide 36. The hot air flows near the seal 35. This makes it difficult for heat to build up around the seal 35, making it possible to lower the temperature of the seal 35. The temperature of the hot air is significantly lower than the temperature of the heating chamber 12.

[0053] 6, the sealing guide 36 has an elongated shape that extends along the longitudinal direction of the seal 35. The sealing guide 36 allows the hot air passing through the space 52 to flow along the longitudinal direction of the seal 35. This makes it possible to lower the temperature of the seal 35 over a wide range.

[0054] The hot air is a fluid supplied to the space 52 by a hot air supply device 53 to prevent condensation on the outer shell 32. The hot air for preventing such condensation is used to lower the temperature of the seal 35.

[0055] As shown in Fig. 6, in this embodiment, hot air is supplied from multiple locations to the space 52 between the heating furnace 11 and the outer case 51. The outer case 51 has a rectifying member (rectifying plate) 55. The rectifying member 55 is arranged so that the hot air supplied to the space 52 spreads throughout the entire space 52. Furthermore, the rectifying member 55 can adjust the flow of the hot air so that the discharged hot air gathers in one discharge pipe 534, which is part of the hot air piping 532.

[0056] [Configuration for the terminal portion 41 of the heater 13] The heating furnace 11 (outer shell 32) is covered with an outer case 51, and a space 52 is formed between the heating furnace 11 and the outer case 51. A hot air supplying device 53 supplies hot air to the space 52. As described above (see FIG. 8), the heater 13 has the terminal portion 41, which is located outside the outer shell 32 of the heating furnace 11. In other words, the terminal portion 41 is located in the space 52. FIG. 8 is an explanatory diagram of the outer case 51 and the heating furnace 11 inside it, looking at the terminal portion 41 side.

[0057] The heater 13 is disposed so as to penetrate the outer shell 32 and the insulating material 31, and when the temperature outside the heating furnace 11 is low, condensation is likely to occur on the terminals 41 and around the terminals 41 located outside the outer shell 32 of the heating furnace 11, so it is necessary to raise the temperature of the terminals 41. In addition, electric wires may be connected to the terminals 41, making it difficult to sufficiently guide hot air to the terminals. Therefore, the heat treatment device 10 of the present invention has a terminal guide 45 provided in the space 52. The terminal guide 45 is a member that guides the hot air flowing through the space 52 toward the terminal portions 41.

[0058] As shown in Fig. 9, the terminal guide 45 is attached to a case outer wall 511 of the outer case 51. Fig. 9 is a cross-sectional view taken along the line IX in Fig. 8. The terminal guide 45 is plate-shaped. When the hot air flowing through the space 52 collides with the terminal guide 45, the hot air changes direction and flows toward the terminal portion 41. The terminal guide 45 guides the hot air passing through the space 52 and blows it onto the terminal portion 41. This increases the temperature of the terminal portion 41 and its surroundings, thereby preventing condensation from forming on the terminal portion 41 and its surroundings. Furthermore, it also prevents electrical leakage at the terminal portion 41 due to water condensation.

[0059] [Regarding the heat treatment device 10 of this embodiment] As described above, the heat treatment apparatus 10 of this embodiment (see FIG. 1 ) has a heating chamber 12, which has a high temperature and a high dew point for heat treatment of the workpiece W. The heat treatment apparatus 10 has a heating furnace 11, a heater 13, and a heating unit 14. The heating furnace 11 has a heat insulating material 31 for insulating the heating chamber 12, and an outer shell 32 that covers the outside of the heat insulating material 31 and prevents gas from passing through. The heater 13 has a terminal portion 41 located on the outside of the outer shell 32, a penetration portion 42 that penetrates the outer shell 32 and the heat insulating material 31, and a heat generating portion 43 located in the heating chamber 12. The heating unit 14 is configured to increase the temperature of the outer shell 32.

[0060] The heat insulating material 31 of this embodiment is made of a high-density fibrous body, which has a high insulating effect but low airtightness, allowing gas to pass through. The outer shell 32 that covers the heat insulating material 31 prevents gas from passing through. Therefore, the high-temperature, high-dew-point gas in the heating chamber 12 does not leak out (high airtightness), and the high-temperature, high-dew-point state is maintained.

[0061] Since the heating furnace 11 is highly airtight, the gases (hydrogen gas, nitrogen gas) used in the heat treatment are not wasted, and the heat treatment can be carried out efficiently. The heat generating portion 43 of the heater 13 is located in the heating chamber 12. Therefore, the heating chamber 12 is directly heated, resulting in good thermal efficiency. It should be noted that a commonly used ordinary insulating material such as a high-density fibrous body can be used as the insulating material 31. There is no need to use a special and expensive material, and the heat treatment device 10 can be configured at a relatively low cost.

[0062] When the inside of the heating furnace 11 (heating chamber 12) is high temperature and has a high dew point, while the temperature outside the heating furnace 11 is low, condensation is likely to occur on the outer shell 32. In the case of the heat treatment device 10 of this embodiment, the heating chamber 12 is in a high dew point environment, but the heating unit 14 increases the temperature of the outer shell 32. As a result, condensation on the outer shell 32 is suppressed.

[0063] In this embodiment, the heating unit 14 is configured to include an outer case 51 and a hot air supply device 53. The outer case 51 covers the heating furnace 11 with a gap therebetween. The hot air supply device 53 supplies hot air to a space 52 formed between the heating furnace 11 and the outer case 51. This configuration makes it easy to increase the temperature of the outer shell 32 of the heating furnace 11 overall over a wide area.

[0064] The heating unit 14 may have a form other than that shown in the drawings. For example, although not shown, the heating unit 14 may be a heater (plane heater) attached to the outer surface of the outer shell 32. The heater increases the temperature of the outer shell 32.

[0065] The heat treatment apparatus 10 of this embodiment has a humidified gas supply unit 15 including a humidifier 71. Gas humidified by the humidifier 71 is supplied to the heating chamber 12. The humidified gas supply unit 15 creates a high dew point environment in the heating chamber 12, and the workpiece W is heat-treated in that environment. Because the heating chamber 12 has a high dew point, condensation is likely to occur on the outer shell 32, but the heating unit 14 increases the temperature of the outer shell 32, making it possible to suppress condensation.

[0066] If the outer shell 32 is made of heat-resistant steel, condensation on the outer shell 32 may cause corrosion, reducing durability and lifespan. However, according to the heat treatment device 10 of this embodiment, even if the outer shell 32 is made of heat-resistant steel, condensation is suppressed, making it possible to prevent a reduction in durability and lifespan. Furthermore, by preventing condensation, it is possible to prevent adverse effects on the heater 13 (such as effects of electrical leakage), and it is possible to prevent the life of the heater 13 from being shortened.

[0067] 〔others〕 The embodiments disclosed herein are illustrative in all respects and are not restrictive. The scope of the present invention is not limited to the above-described embodiments, but includes all modifications within the scope of the claims and equivalents thereof. [Explanation of symbols]

[0068] 10 Heat treatment device 11 Heating furnace 12 Heating chamber 13 Heater 14 Heating section 15 Humidified gas supply unit 16 Processing gas supply unit 31 Insulation 32 outer shell 33 Furnace body 34 First Door 35 stickers 36 Seal guide 41 Terminal section 42 Penetration 43 Heat generating part 45 Terminal guide 51 Outer case 52 Space 53 Hot air supply device 61 Case body 62 Second Door 63 Door insulation material 64 Door covering material 71 Humidifier 331 Furnace wall 332 Aperture 511 Case outer wall 532A, 532B Branch pipe (piping) double work

Claims

1. A heat treatment apparatus having a heating chamber with a high temperature and a high dew point for heat treatment of a workpiece, a heating furnace having a heat insulating material for insulating the heating chamber and an outer shell that covers the outside of the heat insulating material and prevents gas from passing through; a heater having a terminal portion located outside the outer shell, a penetration portion that penetrates the outer shell and the heat insulating material, and a heat generating portion located in the heating chamber; A heating unit for increasing the temperature of the outer shell; A heat treatment device comprising:

2. The heating unit is an outer case covering the heating furnace at a distance from the heating furnace; The heat treatment apparatus according to claim 1 , further comprising: a hot air supplying device that supplies hot air to a space formed between the heating furnace and the outer case.

3. a humidified gas supply unit having a humidifier and supplying gas humidified by the humidifier to the heating chamber; The heat treatment apparatus according to claim 1 or 2.

4. The heating furnace includes a furnace body having the heating chamber therein, a first door attached to the furnace body and capable of being opened and closed for loading and unloading the workpiece, and a seal provided between the furnace body and the first door, The outer case has a case body located outside the furnace body at a distance from the furnace body, and a second door attached to the case body and openable and closable for loading and unloading the workpiece, a seal guide for guiding the hot air toward the seal is provided in the space between the heating furnace and the outer case; The heat treatment apparatus according to claim 2 .

5. The furnace body has a furnace wall provided with an opening through which the first door closes, The seal is provided in an annular shape so as to surround the opening, The seal guide has an elongated shape along the longitudinal direction of the seal. The heat treatment apparatus according to claim 4 .

6. The second door has a door insulation material and a door covering material that covers the door insulation material, The case body is made of a plate member having exposed inner and outer surfaces.

6. The thermal treatment device according to claim 4 or 5.

7. The terminal portion is located in the space, A terminal guide is provided in the space to guide the hot air toward the terminal portion. The heat treatment apparatus according to claim 2 .

8. the outer case has a plurality of outer case walls facing in different directions; The hot air supply device has a plurality of pipes for supplying hot air to the space between each of the plurality of case outer walls and the outer shell. The heat treatment apparatus according to claim 2 .

Images