JP6918347B2 - Heat treatment method and heat treatment equipment - Google Patents

Description

The present invention relates to a heat treatment method for performing a heat treatment on a member to be heat-treated in a container, such as an autoclave molding method, and a heat treatment apparatus thereof.

For example, when molding a fiber-reinforced plastic containing a thermosetting resin or a thermoplastic resin (an example of a member to be heat-treated), it is necessary to heat the fiber-reinforced plastic material and the molding mold for molding the fiber-reinforced plastic material.

In the autoclave molding method, a sheet-shaped fiber reinforced plastic material called prepreg is laminated on a molding mold, housed in a vacuum bag and placed in a pressure vessel (autoclave), the vacuum bag is evacuated, and the vacuum bag is evacuated to gas pressure. It is heated while pressurizing with. For heating, for example, as described in Patent Document 1, a high-temperature gas is circulated in the pressure vessel. Further, when cooling after the heat treatment, the low temperature gas is circulated in the pressure vessel.

Japanese Unexamined Patent Publication No. 2012-171173

The method of putting the member to be heat-treated into the container and circulating the high-temperature gas to heat the container is time-consuming because it is necessary to raise the temperature of the entire inside of the container to a desired target temperature. Further, in the case of a three-dimensional molded product, since there are parts having different thicknesses, it is necessary to slowly raise the temperature in order to uniformly heat the whole, which takes time. In addition, a lot of energy is required to heat the entire inside of the container to the desired target temperature.

When cooling with a low-temperature gas after the heat treatment, it takes time to cool the member to be heat-treated because the entire inside of the container is hot.

The present invention has been made to solve the above-mentioned problems, and is a heat treatment method capable of uniformly heating a member to be heat-treated in a short time and uniformly cooling the member to be heat-treated in a short time while saving energy. It is an object of the present invention to provide a heat treatment apparatus.

The heat treatment method according to claim 1 of the scope of the patent claim, which is performed to achieve the above object, directly heats the member to be heat-treated by bringing a direct heater into contact with the member to be heat-treated. the arrangement or the thermally treated member so as to be placed into contact via the auxiliary materials, the arranged an auxiliary heater for heating the interior space of the container for accommodating the thermally treated member, the inner wall of the container An inner wall cooler to be cooled is arranged, a mounting table cooler for cooling the mounting table on which the member to be heat-treated is placed, an internal space temperature sensor for measuring the internal space temperature of the container is arranged, and the heat-treated object is heat-treated. A plurality of target temperature sensors for measuring the temperature of a plurality of parts of the member are arranged, and the internal space temperature is heated so as to be lower than the target temperature which is the heating target of the member to be heat-treated, and the plurality of target temperature sensors are heated. The direct heater, the auxiliary heater, the inner wall cooler, and the above-mentioned stand cooler are controlled to heat the member to be heat-treated so that the temperature detected by the target temperature sensor becomes the target temperature. It is a feature.

The heat treatment method according to claim 2 is the one according to claim 1, and is characterized in that, at the start of heat treatment, the auxiliary heater is first operated and then the direct heater is operated.

The heat treatment method according to claim 3 is the one according to claim 1 or 2, wherein the member to be heat-treated is a fiber-reinforced plastic material containing a thermosetting resin or a thermoplastic resin, and the fiber-reinforced plastic. The material and a molding die for molding the material are housed in a vacuum bag, and the vacuum bag is evacuated and the inside of the container is pressurized to perform autoclave molding.

The heat treatment method according to claim 4 is the one according to claim 3, wherein a mold cooler for cooling the mold is arranged, and the temperature detected by the plurality of target temperature sensors becomes the target temperature. It is characterized in that the direct heater, the auxiliary heater, the inner wall cooler, the above-mentioned stand cooler, and the molded cooler are controlled so as to be.

The heat treatment method according to claim 5 is the one according to any one of claims 1 to 4, and the internal space temperature is expressed from 50% of the target temperature when the target temperature is expressed in degrees Celsius. It is characterized in that the auxiliary heater and the inner wall cooler are controlled so as to have a predetermined temperature within a range of 80%.

The heat treatment method according to claim 6 is the one according to any one of claims 1 to 5, and at the start of heat treatment, after the auxiliary heater is first operated, the internal space temperature becomes the target temperature. It is characterized in that the operation of the direct heater is started after the temperature reaches a temperature in the range of 30% to 80%.

The heat treatment method according to claim 7 is the one according to any one of claims 1 to 6, wherein a plurality of heaters whose temperature can be controlled independently are arranged as the direct heater. do.

The heat treatment method according to claim 8 is the one according to any one of claims 1 to 7, characterized in that the auxiliary heater is arranged below the member to be heat-treated.

The heat treatment method according to claim 9 is the one according to any one of claims 1 to 8, and as the inner wall cooler, a cooling pipe formed spirally so as to be in contact with the inner wall of the container is arranged. It is characterized by doing.

The heat treatment apparatus according to claim 10 directly heats a container for accommodating a member to be heat-treated, a mounting table on which the member to be heat-treated is placed, and the member to be heat-treated. arranged or the like is brought into contact with the member being disposed so as to contact via the auxiliary materials to be thermally member, a direct heater, an auxiliary heater for heating the interior space of said container, said container An inner wall cooler that cools the inner wall, a stand cooler that cools the stand described above, a plurality of target temperature sensors that measure the temperature of a plurality of parts of the member to be heat-treated, and an internal space temperature of the container are measured. The internal space temperature sensor and the internal space temperature are heated so as to be lower than the target temperature for heating the member to be heat-treated, and the temperature detected by the plurality of target temperature sensors becomes the target temperature. In addition, the direct heater, the auxiliary heater, the inner wall cooler, and the control unit for controlling the above-mentioned stand cooler are provided to heat the member to be heat-treated.

The heat treatment apparatus according to claim 11 is the one according to claim 10, wherein the control unit operates the auxiliary heater first and then the direct heater at the start of heat treatment. And.

The heat treatment apparatus according to claim 12 is the one according to claim 10 or 11, wherein the member to be heat-treated is a fiber-reinforced plastic material containing a thermosetting resin or a thermoplastic resin, and the fiber-reinforced plastic. The material and the molding die for molding the material are housed in a vacuum bag, and the decompression device for vacuuming the vacuum bag and the pressurizing device for pressurizing the inside of the container are provided to enable autoclave molding of the fiber reinforced plastic material. It is characterized by being configured.

The heat treatment apparatus according to claim 13 is the one according to claim 12, wherein the heat treatment apparatus includes a mold cooler for cooling the mold, and the temperature detected by the control unit is determined by the plurality of target temperature sensors. All of them are characterized in that the direct heater, the auxiliary heater, the inner wall cooler, the above-mentioned stand cooler, and the molded cooler are controlled so as to reach the target temperature.

The heat treatment apparatus according to claim 14 is the one according to any one of claims 10 to 13, and when the control unit expresses the internal space temperature in degrees Celsius, the target. It is characterized in that the auxiliary heater and the inner wall cooler are controlled so as to have a predetermined temperature within a range of 50% to 80% of the temperature.

The heat treatment apparatus according to claim 15 is the one according to any one of claims 10 to 14, wherein the control unit first operates the auxiliary heater at the start of heat treatment, and then the inside. The direct heater is started to operate after the space temperature reaches a temperature within the range of 30% to 80% of the target temperature.

The heat treatment apparatus according to claim 16 is the one according to any one of claims 10 to 15, and a plurality of independently temperature-controllable heaters are arranged as the direct heaters. It is a feature.

The heat treatment apparatus according to claim 17 is the one according to any one of claims 10 to 16, wherein the auxiliary heater is arranged below the member to be heat-treated.

The heat treatment apparatus according to claim 18 is the one according to any one of claims 10 to 17, and as the inner wall cooler, a cooling pipe formed spirally so as to be in contact with the inner wall of the container is arranged. It is characterized by being done.

According to the heat treatment method and the heat treatment apparatus of the present invention, since the direct heater directly heats the member to be heat-treated, the member to be heat-treated can be heated in a short time. Since the auxiliary heater heats the internal space, the member to be heat-treated can be heated faster than when there is no auxiliary heater, and the temperature difference from the surroundings can be reduced, so that the member to be heat-treated is made uniform as a whole. Can be heated. Since the internal space temperature of the container may be heated to a temperature lower than the target temperature, which is the heating target of the member to be heat-treated, energy saving is achieved as compared with the case of heating to the target temperature. Since the inner wall cooler cools the internal space temperature of the container, the internal space temperature can be quickly stabilized to a desired temperature in combination with the heating of the auxiliary heater. Since the mounting table cooler can cool the member to be heat-treated on the side in contact with the mounting table, the temperature of the member to be heat-treated is made uniform by cooling when the side in contact with the mounting table becomes hot. can do. When the heat-treated member on the side not in contact with the mounting table becomes hot, the temperature of the member to be heat-treated can be made uniform by cooling the internal space temperature with the inner wall cooler. Further, since the inner wall cooler cools the inner wall of the container and the mounting table cooler cools the mounting table on which the heat-treated member is placed, the heat-treated member can be uniformly cooled in a short time.

When the auxiliary heater is operated first at the time of heating to start heating the internal space of the container and then the operation of the heater is started directly, the difference between the target temperature for heating and the ambient temperature of the member to be heat-treated becomes small. The member to be heat-treated can be uniformly heated.

When applied to autoclave molding, fiber reinforced plastics can be molded in a short time.

When the mold cooler for cooling the mold is arranged, for example, by directly controlling the heater and the mold cooler, the temperature of the member to be heat-treated can be controlled accurately in a shorter time. Further, by operating the molded cooler, the member to be heat-treated can be cooled in a short time.

When the auxiliary heater and the inner wall cooler are controlled so that the internal space temperature becomes a predetermined temperature within the range of 50% to 80% of the target temperature when the target temperature is expressed in degrees Celsius, energy saving is achieved. The member to be heat-treated can be uniformly heated in a short time.

When the operation of the heater is directly started after the internal space temperature is within the range of 30% to 80% of the target temperature after the auxiliary heater is operated first at the start of the heat treatment, the member to be heat-treated. Can be heated more uniformly.

When a plurality of heaters whose temperature can be controlled independently are arranged as the direct heater, the heat treatment member can be heated for each part, so that the heat treatment member can be heated more uniformly.

When the auxiliary heater is placed below the member to be heat-treated, the heated lower gas rises and convection occurs inside the container. Therefore, this convection equalizes the temperature of the internal space of the container and makes the container uniform. It is not necessary to install a gas circulation device such as a fan inside the container, which saves energy. Further, since the mounting table can be heated by the auxiliary heater, the temperature of the mounting table can be controlled.

When a cooling pipe formed spirally so as to be in contact with the inner wall of the container is arranged as the inner wall cooler, the entire container can be cooled in a short time, so that the internal space temperature can be cooled in a short time and the heat treatment is performed. The temperature of the member can be controlled in a shorter time.

It is a vertical cross-sectional view which shows typically the fiber reinforced plastic molding apparatus which is an example of the heat treatment apparatus to which this invention is applied. It is sectional drawing which shows typically the fiber reinforced plastic molding apparatus which is an example of the heat treatment apparatus to which this invention is applied. It is sectional drawing which shows typically the heat treatment block. (A) is an example in which the direct heater (first direct heater and the second direct heater) is arranged outside the vacuum bag, and (b) is the direct heater (first direct heater and the first direct heater). This is an example in which the direct heater of 2) is arranged inside the vacuum bag. (B) shows an example in which the molding die has irregularities. (C) is an example in which the direct heaters (the first direct heater and the second direct heater) are arranged inside the molding die. It is an electric block diagram of the fiber reinforced plastic molding apparatus which is an example of the heat treatment apparatus to which this invention is applied. It is sectional drawing which shows typically the heat treatment block used for the adhesive processing apparatus which is an example of the heat treatment apparatus to which this invention is applied. It is sectional drawing which shows typically the heat treatment block used for the defoaming treatment apparatus which is an example of the heat treatment apparatus to which this invention is applied. It is a graph which shows the measurement result of Example 1. FIG. It is a graph which shows the measurement result of Example 2. It is a graph which shows the measurement result of the comparative example 1. FIG. It is a graph which shows the measurement result of Example 3. It is a graph which shows the measurement result of the comparative example 2. It is a graph which shows the measurement result of the comparative example 3. It is a graph which shows the measurement result of Example 4. It is a graph which shows the measurement result of Example 5. It is a graph which shows the measurement result of Example 6. It is a graph which shows the measurement result of Example 7. It is a graph which shows the measurement result of Example 8. It is a graph which shows the measurement result of Reference Example 1. FIG. It is a graph which shows the measurement result of Example 9.

Hereinafter, embodiments for carrying out the present invention will be described in detail, but the scope of the present invention is not limited to these examples.

1 to 4 show a heat treatment apparatus 1 to which the present invention is applied. The heat treatment apparatus 1 is, for example, a fiber reinforced plastic molding apparatus. Hereinafter, the heat treatment apparatus 1 is also referred to as a fiber reinforced plastic molding apparatus 1. As shown in FIGS. 1 and 2, the fiber reinforced plastic molding apparatus 1 autoclaves the fiber reinforced plastic material (heat-treated member 101) as an example. The fiber-reinforced plastic molding apparatus 1 includes a pressure container 2, a mounting table 3, a first direct heater 4A, a second direct heater 4B, a first auxiliary heater 4C, a second auxiliary heater 4D, and an inner wall cooling. Instrument 5X, stand cooler 5Y, molded cooler 5Z (see FIG. 3A), cooling source 21, cooling source 22, cooling source 23, first target temperature sensor 31 (see FIG. 3A). , Second target temperature sensor 32 (see FIG. 3 (a)), internal space temperature sensor 33, mounting table temperature sensor 34, first direct heater temperature sensor 41A (see FIG. 3 (a)), second Direct heater temperature sensor 41B (see FIG. 3A), first auxiliary heater temperature sensor 41C, second auxiliary heater temperature sensor 41D, inner wall cooler temperature sensor 41X, mounting table cooler temperature sensor 41Y, It includes a molded cooler temperature sensor 41Z (see FIG. 3A), a decompression device 11, a pressurization device 14, and a control unit 8. In the fiber reinforced plastic molding apparatus 1, the heat treatment block 6 is placed on the mounting table 3 to perform molding (heat treatment). In FIG. 2, the temperature sensor and the like are not shown.

As will be described in detail later, the heat treatment block 6 has a heat-treated member 101 (see FIG. 3A), a direct heater 4A that heats the upper side of the heat-treated member 101, and a lower side of the heat-treated member 101. It is provided with a direct heater 4B for heating.

The pressure vessel 2 houses the member 101 to be heat-treated (see FIG. 3A) inside. The pressure vessel 2 is a metal pressure vessel (pressurized vessel) capable of increasing the internal pressure to a pressure higher than normal pressure (1 atm), and in this example, it is a pressure vessel for an autoclave. The pressure vessel 2 is formed in a substantially cylindrical shape as an example, and FIG. 1 schematically shows a vertical sectional view thereof. The pressure vessel 2 includes an opening / closing door 2a for taking in and out the heat treatment block 6. A mounting table 3 is arranged inside the pressure vessel 2.

The mounting table 3 is for mounting the heat treatment block 6 (heat-treated member 101). The mounting table 3 is formed in a plate shape and is arranged horizontally. The mounting table 3 may be configured to be movable in the opening / closing door 2a direction by, for example, a roller or a rail so that the heat treatment block 6 can be easily taken in and out of the pressure vessel 2.

The mounting table 3 is made of a metal such as aluminum having good thermal conductivity. A mounting table cooler 5Y for cooling the mounting table 3 is arranged on the mounting table 3. The mounting table cooler 5Y may be any device as long as it can cool the mounting table 3. The temperature of the mounting table cooler 5Y is controlled by the control unit 8.

As an example, the mounting table cooler 5Y is a cooling pipe (hereinafter, also referred to as a cooling pipe 5Y) through which a heat medium for cooling (for example, water) passes through the inside. The cooling pipe 5Y is formed in a zigzag shape as an example. The mounting table 3 is divided into upper and lower parts, for example, and is arranged so that the cooling pipe 5Y is embedded inside the mounting table 3. The cooling pipe 5Y is connected to a cooling source 22 arranged outside the pressure vessel 2. The cooling source 22 is, for example, a cooling heat medium circulation device, which is known to cool the heat medium and circulate it in the cooling pipe 5Y. Alternatively, the cooling source 22 may be of a type in which the heat medium drips without circulating. The shape of the cooling pipe 5Y is not limited to a zigzag shape, and can be formed into any shape. The mounting table cooler 5Y may be a Perche element.

An auxiliary heater 4C is arranged inside the pressure vessel 2. The auxiliary heater 4C auxiliary heats the internal space of the pressure vessel 2. The auxiliary heater 4C is, for example, an electric heater. The auxiliary heater 4C is arranged at an arbitrary position inside the pressure vessel 2, but is preferably arranged below the heat treatment block 6 (heat treatment member 101). The auxiliary heater 4C may be arranged below the mounting table 3 so as not to be in contact with the mounting table 3, or may be arranged below the mounting table 3 in contact with the mounting table 3. It may be arranged inside the mounting table 3, or may be arranged so as to come into contact with the upper part of the mounting table 3. The heating temperature of the auxiliary heater 4C is controlled by the control unit 8.

A plurality of auxiliary heaters may be arranged. The figure shows an example in which a plurality of (two as an example) auxiliary heaters 4C and auxiliary heaters 4D are arranged. Although only one of the auxiliary heater 4C and the auxiliary heater 4D may be arranged, it is preferable to arrange the auxiliary heater 4C located at least below the heat treatment block 6 (heat treatment member 101).

An inner wall cooler 5X is arranged inside the pressure vessel 2. The inner wall cooler 5X is for cooling the inner wall (wall portion) of the pressure vessel 2. The inner wall cooler 5X may be any as long as it can cool the inner wall. The temperature of the inner wall cooler 5X is controlled by the control unit 8.

The inner wall cooler 5X is, for example, a cooling pipe (hereinafter, also referred to as a cooling pipe 5X) through which a heat medium for cooling (for example, water) passes through the inside. As an example, the cooling pipe 5X is formed in a spiral shape (coil shape) having an outer diameter and a cylinder length substantially similar to the cylindrical inner wall of the pressure vessel 2, so as to be in contact with the inner wall of the pressure vessel 2. Have been placed. The cooling pipe 5X may be in contact with the surface of the inner wall of the pressure vessel 2, or may be in contact with the inner wall of the pressure vessel 2 so as to be embedded in the inner wall. The cooling pipe 5X is connected to a cooling source 21 arranged outside the pressure vessel 2. The cooling source 21 is, for example, a cooling heat medium circulation device, which is known to cool the heat medium and circulate it in the cooling pipe 5X. Alternatively, the cooling source 22 may be of a type in which the heat medium drips without circulating. The shape of the cooling pipe 5X is not limited to the spiral shape, and can be formed into any shape. The cooling pipe 5X may be embedded in the wall of the pressure vessel 2. The inner wall cooler 5X may be a Perche element.

Further, a plurality of temperature sensors are arranged in the pressure vessel 2. The internal space temperature sensor 33 measures the internal space (internal gas) temperature of the pressure vessel 2. The internal space temperature sensor 33 is preferably arranged on the upper side of the inner space of the pressure vessel 2. The mounting table temperature sensor 34 measures the temperature of the mounting table 3. The auxiliary heater temperature sensor 41C measures the temperature of the auxiliary heater 4C. The auxiliary heater temperature sensor 41D measures the temperature of the auxiliary heater 4D. The inner wall cooler temperature sensor 41X measures the temperature of the inner wall cooler 5X. The mounting table cooler temperature sensor 41Y measures the temperature of the mounting table cooler 5Y. These temperature sensors 33 to 41Y are known, for example, thermocouples.

FIG. 3A shows the heat treatment block 6. The heat treatment block 6 includes a member 101 to be heat-treated, and auxiliary materials for heat treatment (for molding) such as a molding die 102 for molding and a vacuum bag 103, and a plurality of direct heaters 4A. And a direct heater 4B.

The direct heater 4A and the direct heater 4B directly contact the member 101 to be heat-treated, which is arranged so as to be in contact with the member 101 to be heat-treated or to be brought into contact with the member 101 to be heat-treated via an auxiliary material. It is to be heated. As an example, the direct heater 4A is arranged above the heat-treated member 101 via a vacuum bag 103 (an example of an auxiliary material), and directly heats the upper side of the heat-treated member 101. As an example, the direct heater 4B is arranged below the heat-treated member 101 via a molding die 102 and a vacuum bag 103 (both are examples of auxiliary materials), and the lower side of the heat-treated member 101 is directly placed. It is to be heated. The temperature of the plurality of direct heaters 4A and the direct heater 4B can be controlled independently.

When a plurality of direct heaters are arranged on the member 101 to be heat-treated, it is preferable to arrange the direct heaters at a portion where the temperature difference of the member 101 to be heat-treated is large. For example, since the temperature difference between the upper part and the lower part of the heat-treated member 101 tends to be large, the heater 4A is arranged directly above the heat-treated member 101, and the heater 4B is directly placed below the heat-treated member 101. It is preferable to arrange it. A plurality of direct heaters may be arranged so as to be divided into arbitrary positions where the temperature difference becomes large according to the shape of the member 101 to be heat-treated.

The direct heater 4A may be any as long as it can heat the member 101 to be heat-treated, and is, for example, an electric heater. The temperature at which the direct heater 4A is heated is controlled by the control unit 8. When the direct heater 4A is a flexible sheet-shaped heater or cloth-shaped heater, the shape changes according to the three-dimensional shape of the heat-treated member 101 and comes into close contact with the heat-treated member 101. The direct heater 4A may be a hard one formed in advance according to the three-dimensional shape of the member 101 to be heat-treated.

The direct heater 4B may be any as long as it can heat the member 101 to be heat-treated, and is, for example, an electric heater. The direct heater 4A and the direct heater 4B may be different types of heaters. The temperature at which the direct heater 4B is heated is controlled by the control unit 8. When the direct heater 4B is a flexible sheet-shaped heater or cloth-shaped heater, the shape changes according to the three-dimensional shape of the molding die 102 and comes into close contact with the molding die 102. The direct heater 4B may be a hard one formed in advance according to the three-dimensional shape of the molding die 102.

In this example, the member 101 to be heat-treated is a fiber-reinforced plastic material containing a thermosetting resin or a thermoplastic resin. In autoclave molding, a sheet-shaped fiber-reinforced plastic material (hereinafter, also referred to as prepreg 101) called a prepreg is used as the member to be heat-treated, and the prepreg 101 is laminated on the molding die 102. The prepreg 101 is obtained by impregnating fibers with a thermosetting resin or a thermoplastic resin (matrix). Examples of the fiber of the prepreg 101 include carbon fiber, glass fiber, and resin fiber. Carbon fiber reinforced plastic (CFRP) using carbon fiber is preferably used for structures such as aircraft and space equipment. In order to facilitate the peeling of the prepreg 101 from the molding die 102 after molding, a peeling sheet or a peeling agent may be arranged between the prepreg 101 and the molding die 102.

The mold 102 is made of metal, resin, wood or plaster as an example. The molding die 102 may be formed in a complicated three-dimensional shape. Although the example in which the prepreg 101 is arranged on the upper side of the molding die 102 is shown, the prepreg 101 may be arranged on the lower side (mounting table 3 side) or the side portion side of the molding die 102.

A mold cooler 5Z for cooling the mold 102 is arranged in the mold 102. The mold cooler 5Z may be any mold as long as it can cool the mold 102. The temperature of the molded cooler 5Z is controlled by the control unit 8 (see FIGS. 1 and 4). It is preferable that the molded cooler 5Z is provided, but it may be omitted if necessary.

The molded cooler 5Z is, for example, a cooling pipe (hereinafter, also referred to as a cooling pipe 5Z) through which a heat medium for cooling (for example, water) passes through the inside. The cooling pipe 5Z is formed in a zigzag shape as an example. The molding die 102 is divided into upper and lower parts, for example, and is arranged so that the cooling pipe 5Z is embedded inside the molding die 102. The cooling pipe 5Z is connected to a cooling source 23 (see FIG. 1) arranged outside the pressure vessel 2. The cooling source 23 is, for example, a cooling heat medium circulation device, which is known to cool the heat medium and circulate it in the cooling pipe 5Z. Alternatively, the cooling source 23 may be of a type in which the heat medium drips without circulating. The shape of the cooling pipe 5Z is not limited to a zigzag shape, and can be formed into any shape. The molded cooler 5Z may be a Perche element.

As shown in FIG. 1, an example in which the cooling source 21 is connected to the inner wall cooler 5X, the cooling source 22 is connected to the mounting table cooler 5Y, and the cooling source 23 is connected to the molded cooler 5Z. As shown, the inner wall cooler 5X, the mounting stand cooler 5Y, and the molded cooler 5Z may be connected to one cooling source by piping. In this case, the temperature may be adjusted by adjusting the flow rate of the heat medium flowing through each of the inner wall cooler 5X, the mounting table cooler 5Y, and the molded cooler 5Z, for example, by using a control valve.

The vacuum bag 103 is a flexible bag or sheet for bagging the prepreg 101 and the mold 102. The vacuum bag 103 may be integrally formed in a bag shape, or may be formed in a bag shape by laminating the peripheral edges of two sheets with an adhesive or a sealing material. Further, the vacuum bag 103 may be one in which the peripheral edge portion of one sheet is attached to the molding die 102 with an adhesive or a sealing material. The vacuum bag 103 is made of a material that can withstand the temperature at the time of molding.

In the heat treatment block 6, a plurality of (two as an example) target temperature sensors 31 and 32 for measuring the temperature of a plurality of points of the member 101 to be heat-treated (prepreg 101) are arranged. It is preferable that the plurality of target temperature sensors 31 and 32 are arranged at a portion where the temperature difference of the member 101 to be heat-treated becomes large. For example, since the temperature difference between the upper part and the lower part of the heat-treated member 101 tends to be large, the target temperature sensor 31 is arranged above the heat-treated member 101 and the target temperature sensor 32 is arranged below the heat-treated member 101. It is preferable to do so. When a plurality of direct heaters 4A and 4B are arranged, a plurality of target temperature sensors 31 and 32 may be arranged so as to measure the temperature of the heat-treated member 101 at a portion close to the plurality of direct heaters 4A and 4B. This is good. The target temperature sensors 31 and 32 may be arranged in contact with the heat-treated member 101, may be arranged slightly away from the heat-treated member 101, or may be arranged inside the heat-treated member 101. You may. In the figure, an example in which two target temperature sensors 31 and 32 are arranged is shown, but two or more target temperature sensors may be arranged depending on the shape of the member 101 to be heat-treated.

Further, the heat treatment block 6 is provided with a direct heater temperature sensor 41A for directly measuring the temperature of the heater 4A and a direct heater temperature sensor 41B for measuring the temperature of the direct heater 4B. Is preferable. Further, it is preferable that the molded cooler temperature sensor 41Z for measuring the temperature of the molded cooler 5Z is arranged.

The heat treatment block 6 of FIG. 3A shows an example in which the direct heater 4A and the direct heater 4B are arranged outside the vacuum bag 103. The heat treatment block 6a of FIG. 3B shows an example in which the direct heater 4A and the direct heater 4B are arranged inside the vacuum bag 103. In this way, the direct heater 4A and the direct heater 4B may be arranged inside or outside the vacuum bag 103. Note that FIG. 3A shows an example in which the molding die 102 is formed in a flat plate shape, and FIG. 3B shows an example in which the molding die 102a is formed in a plate shape having irregularities. ing.

As shown in FIG. 3B, when the direct heater 4A and the direct heater 4B are arranged inside the vacuum bag 103, the direct heater 4A is close to the direct heater 4A, so that the member 101 to be heat-treated can be easily heated. It is preferable because the mold 102 and the member 101 to be heat-treated can be easily heated because the direct heater 4B is close to the heater.

The decompression device 11 shown in FIG. 1 evacuates the vacuum bag 103. The decompression device 11 has a vacuum pump 12 and a pipe 13 connected to the vacuum pump 12. The vacuum pump 12 is arranged outside the pressure vessel 2. The pipe 13 is connected to the vacuum bag 103, and the inside of the vacuum bag 103 is evacuated by the vacuum pump 12. In FIGS. 2 and 3, the piping 13 is not shown.

The pressurizing device 14 pressurizes the inside of the pressure vessel 2. The pressurizing device 14 has a compressor 15 that pressurizes an inert gas such as nitrogen gas or argon gas, and a pipe 16 that connects to the compressor 15. The compressor 15 is arranged outside the pressure vessel 2. The pipe 16 is connected to the inside of the pressure vessel 2, and the inside of the pressure vessel 2 is pressurized with a high pressure gas.

As the member to be heat-treated (prepreg) 101, the vacuum bag 103, the depressurizing device 11, and the pressurizing device 14, the same members as those used in the conventional autoclave molding can be used.

FIG. 4 shows an electrical block diagram of the fiber reinforced plastic molding apparatus 1. The control unit 8 comprehensively controls the operation of the fiber reinforced plastic molding apparatus 1, and includes a CPU, a memory, an external interface circuit, and the like, although not shown.

The control unit 8 includes a direct heater 4A, a direct heater 4B, an auxiliary heater 4C, an auxiliary heater 4D, a cooling source 21 (inner wall cooler 5X), a cooling source 22 (mounting table cooler 5Y), and a cooling source 23. (Molded cooler 5Z), target temperature sensor 31, target temperature sensor 32, internal space temperature sensor 33, mounting table temperature sensor 34, direct heater temperature sensor 41A, direct heater temperature sensor 41B, auxiliary heater temperature sensor 41C , Auxiliary heater temperature sensor 41D, inner wall cooler temperature sensor 41X, mounting table cooler temperature sensor 41Y, molded cooler temperature sensor 41Z, decompression device 11 and pressurizing device 14 are connected.

Next, the operation of the fiber reinforced plastic molding apparatus 1 will be described while explaining the fiber reinforced plastic molding method which is an example of the heat treatment method to which the present invention is applied.

The fiber-reinforced plastic molding method to which the present invention is applied is arranged so as to be in contact with the member to be heat-treated 101 or to be brought into contact with the member to be heat-treated 101 via an auxiliary material (molding mold 102, vacuum bag 103, etc.). Auxiliary heater for arranging the direct heaters (direct heater 4A, direct heater 4B) for directly heating the heat-treated member 101 and heating the internal space of the pressure vessel 2 for accommodating the heat-treated member 101. (Auxiliary heater 4C, auxiliary heater 4D) is arranged, an inner wall cooler 5X for cooling the inner wall of the pressure vessel 2 is arranged, and a mounting table cooler 5Y for cooling the mounting table 3 on which the member 101 to be heat-treated is placed. , A mold cooler 5Z for cooling the mold 102, an internal space temperature sensor 33 for measuring the temperature (internal space temperature) in the pressure vessel 2, and an upper side of the member 101 to be heat-treated. A target temperature sensor 31 for measuring the temperature and a target temperature sensor 32 for measuring the temperature on the lower side of the member to be heat-treated 101 are arranged so that the internal space temperature becomes lower than the target temperature for heating the member to be heat-treated 101. Direct heater 4A, direct heater 4B, auxiliary heater 4C, auxiliary heater 4D, inner wall cooling so that the temperature detected by the target temperature sensor 31 and the target temperature sensor 32 becomes the target temperature. It controls the device 5X and the mounting table cooler 5Y.

At the start of the heat treatment, it is preferable to start the operation of the auxiliary heater 4C and the auxiliary heater 4D first, and then start the operation of the direct heater 4A and the direct heater 4B. In this case, when the target temperature is expressed in degrees Celsius (Celsius degree, ° C), the internal space temperature is within the range of 30% to 80% (30% or more and 80% or less) of the target temperature, and then directly. It is more preferable to start the operation of the heater 4A and the direct heater 4B.

Further, the auxiliary heaters 4C and 4D and the inner wall cooler 5X are controlled and heated so that the internal space temperature becomes a predetermined temperature within the range of 50% to 80% (50% or more and 80% or less) of the target temperature. Is preferable.

The member 101 to be heat-treated is a fiber-reinforced plastic material containing a thermosetting resin or a thermoplastic resin, and the fiber-reinforced plastic material and the molding die 102 for molding the fiber-reinforced plastic material are housed in a vacuum bag 103. It is preferable that the vacuum bag 103 is evacuated and the inside of the pressure vessel 2 is pressurized to autoclave the member 101 to be heat-treated. It is preferable to arrange the mold cooler 5Z for cooling the mold 102. So that the temperature detected by the plurality of target temperature sensors 31 and 32 becomes the target temperature.
It is preferable to control the direct heater 4A, the direct heater 4B, the auxiliary heater 4C, the auxiliary heater 4D, the inner wall cooler 5X, the mounting table cooler 5Y, and the molded cooler 5Z. By arranging the mold cooler 5Z that cools the mold 102, the temperature control of the member 101 to be heat-treated can be performed accurately in a shorter time by directly controlling the heaters 4A and 4B and the mold cooler 5Z. can. Further, by operating the molded cooler 5Z, the member 101 to be heat-treated can be cooled in a short time. The arrangement of the molded cooler 5Z may be omitted.

Hereinafter, a specific description will be given.

When performing autoclave molding, as an example, a heat treatment block 6 is prepared outside the pressure vessel 2. First, as shown in FIG. 3A, the heat-treated member (prepreg) 101 is laminated on the molding die 102. At this time, the target temperature sensor 31 is set on the upper part of the heat-treated member 101, and the target temperature sensor 32 is set on the lower part. Subsequently, the prepreg 101 and the molding die 102 are housed in the vacuum bag 103. The heater 4A is placed directly on the upper part of the vacuum bag 103, and the heater 4B is placed directly on the lower part of the vacuum bag 103.

Next, the opening / closing door 2a of the pressure vessel 2 is opened, and the heat treatment block 6 is placed on the mounting table 3. The cooling source 23 is connected to the mold cooler 5Z of the mold 102. The piping 13 of the decompression device 11 is set in the vacuum bag 103. The opening / closing door 2a of the pressure vessel 2 is closed to prepare for molding.

Subsequently, the fiber reinforced plastic molding apparatus 1 is operated.

The control unit 8 operates the vacuum pump 12 of the decompression device 11 to evacuate the inside of the vacuum bag 103. At the same time, the control unit 8 operates the compressor 15 of the pressurizing device 14 to pressurize the inside of the pressure vessel 2 with high pressure gas to a predetermined pressure. As a result, the air inside the vacuum bag 103 is discharged, there is no space such as a gap inside the vacuum bag 103, and the fiber reinforced plastic material 101 and the molding die 102 are pressed against the vacuum bag 103 so as to be in close contact with each other.

Further, the control unit 8 starts the heat treatment (heating). The timing at which the control unit 8 starts the heat treatment (heating by the direct heaters 4A and 4B and the auxiliary heaters 4C and 4D) is arbitrary. The control unit 8 may start the heat treatment at the same time as the operation of the depressurizing device 11 and the pressurizing device 14 is started, or the operation of the depressurizing device 11 and the pressurizing device 14 is started to bring the inside of the pressure vessel 2 to a predetermined pressure. The heat treatment may be started after the pressure is applied. In order to shorten the time, it is preferable that the control unit 8 starts the heat treatment at the same time as the operation of the depressurizing device 11 and the pressurizing device 14 is started.

At the start of the heat treatment, the control unit 8 starts the operation (heating) of the auxiliary heater 4C and the auxiliary heater 4D to start heating the internal space of the pressure vessel 2, and then the direct heater 4A and the direct heater. It is preferable to start the operation (heating) of 4B. That is, after the internal space temperature of the pressure vessel 2 becomes higher than the temperature of the heat-treated member 101, the control unit 8 directly operates the heater 4A and the direct heater 4B to directly operate the heat-treated member 101. It is preferable to start heating. The control unit 8 detects the temperature of the internal space of the pressure vessel 2 by the internal space temperature sensor 33. The control unit 8 detects the temperature of the member 101 to be heat-treated by the target temperature sensors 32 and 33. Further, the control unit 8 detects the temperature of each unit by other temperature sensors.

For example, after the control unit 8 starts the operation of the auxiliary heater 4C and the auxiliary heater 4D, the internal space temperature is higher than that of the member 101 to be heat-treated, and the target temperature that is the heating target of the member 101 to be heat-treated ( It is more preferable to start the operation of the direct heater 4A and the direct heater 4B after the temperature is within the range of 30% to 80% (30% or more and 80% or less) of the molding temperature). Alternatively, the control unit 8 is subjected to, for example, 10 ° C. or higher, preferably 20 ° C. or higher, more preferably 30 ° C. or higher, still more preferably 40 ° C. or higher, and then the internal space temperature becomes higher than the temperature of the member 101 to be heat-treated. It is more preferable to start the operation of the direct heater 4A and the direct heater 4B. Depending on the heating conditions, the direct heaters 4A and 4B and the auxiliary heaters 4C and 4D may be operated at the same time, or the direct heaters 4A and 4B may be operated first to operate the auxiliary heaters 4C and 4D. It may be activated later.

The target temperature (molding temperature) is, for example, the maximum temperature for heat-treating (molding) the member 101 to be heat-treated. The target temperature (molding temperature) may be appropriately set according to the type of the member 101 to be heat-treated and the heat treatment conditions. For example, when an epoxy resin is used as the thermosetting resin, the curing temperature of the epoxy resin is about 100 to 250 ° C., so that the curing temperature may be set as the target temperature. For example, when polyimide is used as the thermosetting resin, the curing temperature of the polyimide is about 300 to 400 ° C., so that the curing temperature may be set as the target temperature. Depending on the heat treatment, the target temperature may be constant regardless of the time change, or the target temperature may be changed according to a predetermined condition such as a time change.

For example, when the member 101 to be heat-treated is an epoxy resin and the target temperature (molding temperature) to be heated is set to 130 ° C., the internal space temperature rises after the operation of the auxiliary heater 4C and the auxiliary heater 4D is started. As an example, it is preferable to start the operation of the direct heater 4A and the direct heater 4B when the temperature reaches the temperature in the range of 39 ° C. to 104 ° C., which is the temperature in the range of 30% to 80%.

The auxiliary heaters 4C and 4D do not heat the internal space of the pressure vessel 2 to the target temperature (molding temperature) required for molding the member 101 to be heat-treated, but supplement the internal space to a temperature lower than the molding temperature. It is for heating. The control unit 8 detects the internal space temperature by the internal space temperature sensor 33, feedback-controls the auxiliary heaters 4C and 4D, and the internal space temperature detected by the internal space temperature sensor 33 is the heating target of the member 101 to be heat-treated. It is preferable to control the temperature so that it becomes a predetermined temperature lower than the target temperature (molding temperature). It is more preferable that the control unit 8 detects the internal space temperature by the internal space temperature sensor 33 and feedback-controls the auxiliary heaters 4C and 4D and the inner wall cooler 5X so that the internal space temperature becomes a predetermined temperature. By controlling the auxiliary heaters 4C and 4D and the inner wall cooler 5X in this way, the internal space temperature can be accurately stabilized at a predetermined temperature in a short time.

When the target temperature is expressed in degrees Celsius, the control unit 8, as an example, makes the auxiliary heaters 4C, 4D (and the inner wall) so that the internal space temperature becomes a predetermined temperature within the range of 50% to 80% of the target temperature. It is preferable to control the cooler 5X). When the control unit 8 controls not only the auxiliary heater 4C and the auxiliary heater 4D but also the inner wall cooler 5X, the internal space temperature can be quickly stabilized to a predetermined temperature.

For example, when the member 101 to be heat-treated is an epoxy resin and the target temperature (molding temperature) to be heated is set to 130 ° C., as an example, the temperature is within the range of 50% to 80%, which is 65 ° C. to 104 ° C. It is preferable to control the internal space temperature to a predetermined temperature within the range. At the start of heat treatment (at the start of heating), it is more preferable to operate the auxiliary heaters 4C and 4D first to reach the predetermined temperature and then directly start the operation of the heaters 4A and 4B. The heaters 4A and 4B may be started to operate directly before the temperature is reached.

Since the direct heater 4A and the direct heater 4B are arranged so as to sandwich the member 101 to be heat-treated from above and below, as compared with the case where the entire internal space of the pressure vessel 2 is heated to the target temperature as in the conventional method, The member 101 to be heat-treated can be heated to a target temperature in a short time. Further, the auxiliary heaters 4C and 4D heat the internal space only to a temperature lower than the target temperature, and the direct heater 4A and the direct heater 4B directly heat the member 101 to be heat-treated, so that the energy required for heating is required. Is less than the conventional method and is energy saving.

The control unit 8 directly feedback-controls the heater 4A based on the temperature detected by the target temperature sensor 31 so that the temperatures of the upper part and the lower part of the member 101 to be heat-treated are at the same desired target temperature, and the target temperature sensor 32. The heater 4B is directly feedback-controlled based on the temperature detected by. By independently controlling the direct heater 4A and the direct heater 4B in this way, even the three-dimensionally shaped member 101 to be heat-treated can be uniformly heated. Further, the control unit 8 may feedback control the molded cooler 5Z based on the temperature detected by the target temperature sensors 31 and 32.

In heat treatment such as autoclave molding, it is important to uniformly heat the member 101 to be heat-treated as a whole. The heat treatment block 6 including the member 101 to be heat-treated is placed so that the lower side is in contact with the mounting table 3, and the upper side is open to the space, so that the surrounding environment is different between the upper part and the lower part. That is, the heat energy escaping from the heat treatment block 6 (heat-treated member 101) to the surroundings is different between the upper part and the lower part. The control unit 8 independently feedback-controls the direct heater 4A and the direct heater 4B so that the upper and lower parts of the member 101 to be heat-treated rise at the same temperature, but when the auxiliary heaters 4C and 4D are not arranged. In Therefore, when the auxiliary heaters 4C and 4D were arranged to supplementally heat the internal space of the pressure vessel 2 in advance, it was found that the pressure vessel 2 could be heated uniformly. The reason is that if the internal space of the pressure vessel 2 is preheated, the member to be heat-treated 101 is auxiliary heated and the temperature difference between the temperature of the member to be heat-treated 101 and the target temperature becomes small, so that the member to be heat-treated is directly heated. It is understood that the heat energy to be heated by the vessel 4A and the direct heater 4B becomes smaller, and the member 101 to be heat-treated can be uniformly heated regardless of the heating capacity of the direct heaters 4A and 4B. Further, it was found that if the auxiliary heaters 4C and 4D are arranged and supplementarily heated, the overshoot can be reduced when the auxiliary heaters 4A and the direct heater 4B are used for heating. If the heating temperature of the auxiliary heaters 4C and 4D is set to a high temperature close to the target temperature, the auxiliary heating takes time and requires a lot of energy. Therefore, when the optimum auxiliary heating temperature was searched for, the pressure container 2 It was found that the internal space of the above should be heated to a temperature within the range of 50% to 80% of the target temperature.

When the auxiliary heater 4C is arranged below the member 101 to be heat-treated, the gas at the bottom of the pressure vessel 2 heated by the auxiliary heater 4C rises and convection occurs inside the pressure vessel 2. Since the temperature of the internal space of the pressure vessel 2 is made uniform by this convection, it is not necessary to provide a gas circulation device such as a fan inside the pressure vessel 2. If necessary, a gas circulation device may be arranged inside the pressure vessel 2.

Further, since the mounting table 3 can be heated by arranging the auxiliary heater 4C on the mounting table 3 or arranging the auxiliary heater 4C below the mounting table 3, the mounting table 3 can be mounted in combination with the mounting table cooler 5Y. The temperature of the pedestal 3 can be controlled.

The control unit 8 directs the heater 4A, the direct heater 4B, and the auxiliary heater so as to maintain the heat-treated member 101 at the target temperature when the upper temperature and the lower temperature of the heat-treated member 101 reach the target temperature. 4C, auxiliary heater 4D, inner wall cooler 5X, mounting table cooler 5Y, and molded cooler 5Z are appropriately controlled. The control unit 8 can detect these temperatures by the temperature sensors 31 to 34 and 41A to 41Z of each unit. Since the target temperature sensor 31 and the direct heater temperature sensor 41A are arranged close to each other, if there is almost no difference in the detected temperatures, only one of them may be arranged and used in combination. Further, since the target temperature sensor 32, the direct heater temperature sensor 41B, and the molded cooler temperature sensor 41Z are arranged close to each other, if there is almost no difference in the detected temperatures, only one of them is arranged. It may be used in combination.

The temperature sensor to be arranged may be appropriately set according to the necessity. Due to the need to control the upper part and the lower part (plural parts) of the member 101 to be heat-treated to the target temperature and the need to control the internal temperature of the pressure vessel 2, the target temperature sensors 31 and 32 and the internal space temperature sensor 33 are used. At least it needs to be placed. The control unit 8 may control the heaters 4A to 4D and the coolers 5X to 5Z so that the target temperature sensors 31 and 32 and the internal space temperature sensor 33 reach the desired temperature. The other temperature sensors 34, 41A to 41Z may be eliminated.

The control unit 8 controls the cooling source 21 to control the temperature of the inner wall cooler 5X. Further, the control unit 8 controls the cooling source 22 to control the temperature of the mounting table cooler 5Y. Further, the control unit 8 controls the cooling source 23 to control the temperature of the molded cooler 5Z.

For example, the direct heater 4A, the direct heater 4B, and the molded cooler 5Z are mainly feedback-controlled so that the upper portion and the lower portion of the member 101 to be heat-treated maintain the target temperature. When it is desired to lower the temperature of the upper part of the member 101 to be heat-treated, the temperature of the inner wall cooler 5X may be controlled to be lowered. When it is desired to lower the temperature of the lower part of the member 101 to be heat-treated, the temperature of the mounting table cooler 5Y may be controlled to be lowered. Further, for example, the auxiliary heaters 4C and 4D and the inner wall cooler 5X are mainly feedback-controlled so that the internal space temperature maintains a predetermined temperature.

The desired target is the member 101 to be heat-treated by operating the direct heater 4A, the direct heater 4B, the auxiliary heater 4C, the auxiliary heater 4D, the inner wall cooler 5X, the mounting table cooler 5Y, and the molded cooler 5Z. Can be stabilized to temperature. By operating these, it is possible to accurately perform temperature control for raising or lowering the temperature according to a desired temperature change characteristic (temperature change curve) with respect to time.

The control unit 8 cools the heat-treated member 101 to room temperature as an example after the heat treatment time required for molding the heat-treated member 101 has elapsed at the target temperature (molding temperature).

In order to cool the member 101 to be heat-treated, the control unit 8 stops the direct heater 4A, the direct heater 4B, the auxiliary heater 4C, and the auxiliary heater 4D, and also stops the inner wall cooler 5X and the mounting table cooler 5Y. The operation of the molded cooler 5Z is started.

Since the molded cooler 5Z cools the heat treatment block 6 including the heat treatment member 101 from the inside, the heat treatment member 101 can be directly cooled.

Since the inner wall cooler 5X is spirally piped along the inner wall of the pressure vessel 2, the wall portion of the pressure vessel 2 is directly cooled as a whole, so that the internal space of the pressure vessel 2 is generally shortened for a short time. Can be cooled with. Therefore, a gas circulation device such as a fan is not required inside the pressure vessel 2. If necessary, a gas circulation device may be arranged inside the pressure vessel 2.

The mounting table cooler 5Y can cool the lower part of the mounting table 3 and the heat treatment block 6 which have become hot during the heat treatment.

By providing the inner wall cooler 5X, the mounting table cooler 5Y, and the molded cooler 5Z, the member 101 to be heat-treated can be cooled in a short time.

The control unit 8 monitors the temperatures detected by the target temperature sensor 31 and the target temperature sensor 32, and directly heats the heater 4A, the direct heater 4B, and the auxiliary so that the upper part and the lower part of the member 101 to be heat-treated have the same temperature. By appropriately controlling the heater 4C, the auxiliary heater 4D, the inner wall cooler 5X, the mounting table cooler 5Y, and the molded cooler 5Z, the member 101 to be heat-treated can be cooled uniformly as a whole. In addition, the temperature can be lowered with a desired temperature change characteristic with respect to time.

This completes the autoclave molding of the member 101 to be heat-treated.

As shown in the heat treatment block 6b of FIG. 3C, the direct heater 4A and the direct heater 4B may be arranged inside the molding die 102b. FIG. 3C shows, as an example, an example in which the molding die 102b is formed in a substantially L shape. The direct heater 4A and the direct heater 4B are arranged at a portion where a temperature difference is likely to occur. Specifically, the direct heater 4A is arranged inside the long piece portion of the substantially L-shaped molding die 102b, and the direct heater 4B is arranged inside the short piece portion of the substantially L-shaped molding die 102b. The member 101 to be heat-treated is directly heated. The target temperature sensor 31 is arranged at a position where the temperature of the portion of the heat-treated member 101 to be heated by the direct heater 4A can be measured. The target temperature sensor 32 is arranged at a position where the temperature of the portion of the heat-treated member 101 to be heated by the direct heater 4B can be measured.

Even in the heat treatment block 6b of FIG. 3C, heat treatment can be performed in the same manner as the heat treatment block 6 of FIG. 3A and the heat treatment block 6a of FIG. 3B. After preliminarily heating the internal space of the pressure vessel 2 with the auxiliary heaters 4C and 4D, the control unit 8 directly controls the heater 4A so that the target temperature sensor 31 reaches the target temperature, and the target temperature sensor 32. By directly controlling the heater 4B by the control unit 8 so that the temperature reaches the target temperature, the member 101 to be heat-treated can be uniformly heated in a short time. Further, the member 101 to be heat-treated can be uniformly cooled in a short time.

In addition, in FIGS. 3A to 3C, an example in which a plurality of (two) direct heaters 4A and 4B are arranged in the heat treatment blocks 6 (6a, 6b) is shown, but the number thereof is arbitrary. Therefore, if necessary, two or more direct heaters may be arranged, or only one direct heater may be arranged. It is preferable to arrange many direct heaters because the temperature of the entire member 101 to be heat-treated can be controlled more uniformly.

The reason why the temperature of the member 101 to be heat-treated can be uniformly controlled even when only one direct heater (for example, any one of the direct heaters 4A and 4B) is arranged is as follows. That is, the temperature on the upper side of the member 101 to be heat-treated can be controlled by controlling the internal space temperature, and the temperature on the lower side of the member 101 to be heat-treated can be controlled by controlling the temperature of the mounting table 3. The internal space temperature can be controlled by the auxiliary heaters 4C and 4D and the inner wall cooler 5X. The temperature of the mounting table 3 can be controlled by the auxiliary heater 4C and the mounting table cooler 5Y. Therefore, even if the temperature of the member 101 to be heat-treated is uneven, the direct heater 4A (or 4B), the auxiliary heaters 4C and 4D, the inner wall cooler 5X, and the mounting table cooler 5Y are controlled to be uniform. Can be done. If necessary, the molded cooler 5Z may be controlled.

To explain in more detail here, in composite material molding, thin materials are laminated one by one to make the thickness of the molded product, but when the thickness is relatively thick, heating and cooling of the material is performed by molding. The surface of the mold and the opposite surface of the non-material (bag surface) need to be heated and cooled at the same temperature at the same time. If this temperature deviates significantly, the rate of cross-linking in which the epoxy solidifies during heat curing becomes non-uniform, residual stress is generated, and the molding quality deteriorates. However, when the molding die is not necessarily metal, there are molds such as wood and plaster as an example, but in this case, the thermal conductivity of the mold is very low, and rather it acts as a heat insulating material. Therefore, heat is transferred from the opposite direction to the mold. At this time, in order to avoid non-uniform heat between the mold surface and the bag surface, it is required that the material is laminated in several layers, for example, 0.5 to 1 mm or less. By making it thinner, the heat transferred from the opposite surface of the mold is blocked by the surface of the mold, and the surface of the mold and the surface of the bag are kept uniform. This method is the same for both the conventional method and the new method. The case of cooling is the same as the case of heating, but since the mold surface gradually warms up, the bag surface can be cooled using air by cooling the space inside the container, but because one side needs a means to actively cool. , Attempts to remove heat from the entire mold by cooling the table instead of cooling the mold. This is the idea of a new law.

As an example of heat treatment, a molding apparatus (heat treatment apparatus) and a molding method (heat treatment method) for performing autoclave molding have been described, but the present invention is not limited to this, and various molding apparatus for molding a thermosetting resin or a thermoplastic resin and various molding apparatus. The present invention can be applied to the molding method. For example, the present invention may be applied to a vacuum bag molding method in which molding is performed without pressurizing the vacuum bag, or the present invention may be applied to an RTM (Resin Transfer Molding) method and a VaRTM method. Here, the RTM (Resin Transfer Molding) method is a method in which a thermosetting resin is injected into a fiber preform enclosed in a molding die and then heat-cured. The Va RTM method is a type of RTM method in which materials are laminated, evacuated, impregnated with a thermosetting resin, and heat-cured. Each of these methods requires heating during molding. The fiber-reinforced plastic molding method and the fiber-reinforced plastic molding apparatus of the present invention can be applied to the heating.

Further, the heat treatment is not limited to the molding process of the fiber reinforced plastic, and the present invention can also be applied to the molding process of a general plastic.

Moreover, although the example using the pressure vessel 2 has been described, if necessary, molding may be performed using a normal pressure vessel that can be used at normal pressure.

Further, the present invention can be applied to heat treatments other than molding.

FIG. 5 shows a heat treatment block 6c when an adhesive treatment is performed as another example of the heat treatment. Since the configuration other than the heat treatment block 6c is the same as the configuration of the heat treatment apparatus 1 shown in FIGS. 1 to 4, illustration and detailed description thereof will be omitted.

As an example, the heat treatment block 6c shown in FIG. 5 is for adhering the member to be adhered 111a and the member to be adhered 111b, which are examples of the members to be heat-treated, with the adhesive member 112. In the heat treatment block 6c, the adhesive member 112 is sandwiched between the member to be adhered 111a and the member to be adhered 111b, and the heater 4A is directly arranged on the outer world side (upper side of the figure) of the member to be adhered 111a to be adhered. The heater 4B is directly arranged on the outside world side (lower side in the figure) of the member 111b, and these are housed in the vacuum bag 103. Further, in the heat treatment block 6c, the first target temperature sensor 31 is arranged between the adhered member 111a and the direct heater 4A, and the second target temperature sensor 31 is arranged between the adhered member 111b and the direct heater 4B. 32 are arranged.

The bonded member 111a and the bonded member 111b are, for example, fiber reinforced plastic or general plastic. The adhesive member 112 is, for example, an epoxy resin. By heating the heat treatment block 6c, the adhesive member 112 is thermoset, and the adhesive member 111a and the adhesive member 111b are adhered to each other. The heat treatment apparatus 1 strongly presses the bonded member 111a and the bonded member 111b by evacuating the vacuum bag 103 and pressurizing it from the outside with a high-pressure gas during the bonding process.

After heating the inside of the pressure vessel 2 at a temperature lower than the target temperature, which is the heating target of the adhesive member 112, by the auxiliary heaters 4C and 4D using the heat treatment apparatus 1 of the present invention (see FIGS. 1 to 4). The control unit 8 independently heats the direct heater 4A, the direct heater 4B, the inner wall cooler 4X, and the mounting table cooler 4Y so that the direct heaters 4A and 4B are heated and the target temperature sensors 31 and 32 reach the target temperature. To control. As a result, the members to be adhered 111a and 111b and the adhesive member 112 can be uniformly heated to the target temperature in a short time and cooled in a short time after the bonding treatment. Since the members to be adhered 111a and 111b and the adhesive member 112 are uniformly heated, temperature unevenness does not occur and the adhesive can be bonded with uniform strength as a whole.

FIG. 6 shows a heat treatment block 6d in the case of performing a defoaming treatment as another example of the heat treatment. Since the configurations other than the heat treatment block 6d are the same as the configurations of the heat treatment apparatus 1 shown in FIGS. 1 to 4, illustration and detailed description thereof will be omitted.

The heat treatment block 6d shown in FIG. 6 is for defoaming the liquid 121, which is an example of the member to be heat-treated, as an example. In the heat treatment block 6d, the liquid 121 is housed in the cylinder 131, the opening of the cylinder 131 is closed by the piston 132, the cylindrical direct heater 4A is arranged on the outer periphery of the cylinder 131, and the outside of the bottom of the cylinder 131 is arranged. The heater 4B is directly arranged in the vacuum bag 103, and these are housed in the vacuum bag 103. The piston 132 is provided with a filter 135 capable of passing only the defoamed gas, and a pipe 13 connected to the decompression device 11 is connected to the filter 135. Further, in the heat treatment block 6d, the first target temperature sensor 31 is arranged on the upper side in the liquid 121, and the second target temperature sensor 32 is arranged on the lower side in the liquid 121.

The liquid 121 is, for example, a liquid epoxy resin. During the defoaming process, the heat treatment apparatus 1 evacuates the vacuum bag 103 and pressurizes it from the outside with a high-pressure gas to push the piston 132 into the cylinder 131, so that the liquid 121 is defoamed. NS.

Using the heat treatment block 6d in the heat treatment apparatus 1 (see FIGS. 1 to 4) of the present invention, the auxiliary heaters 4C and 4D heat the inside of the pressure vessel 2 at a temperature lower than the target temperature which is the heating target of the liquid 121. After that, the direct heaters 4A and 4B are heated, and the control unit 8 directly heats the heaters 4A, 4B, the inner wall cooler 4X, and the mounting table cooler so that the target temperature sensors 31 and 32 reach the target temperature. 4Y is controlled independently. As a result, the liquid 121 can be uniformly heated to the target temperature in a short time and cooled in a short time after the defoaming treatment. Since the liquid 121 is uniformly heated, the liquid 121 does not have uneven temperature, and the liquid 121 can be uniformly defoamed as a whole.

[Temperature control experiment: Examples 1 and 2, Comparative Example 1]
The fiber reinforced plastic molding apparatus 1 shown in FIG. 1 was prototyped. It is provided with direct heaters 4A and 4B, auxiliary heaters 4C, inner wall cooler 5X, and mounting table cooler 5Y. The arrangement of the molded cooler 5Z and the auxiliary heater 4D was omitted. Further, the arrangement of temperature sensors other than the target temperature sensors 31 and 32 and the internal space temperature sensor 33 is omitted. Further, as the direct heaters 4A and 4B, those arranged inside the vacuum bag 103 as shown in FIG. 3B were used. A mold made of aluminum was used as the molding mold 102. As the member 101 to be heat-treated, a prepreg using an epoxy resin was used. The target temperature (molding temperature) is 130 ° C. The molding schedule was room temperature → 130 ° C. → room temperature (water cooling of the inner wall cooler 5X and the mounting table cooler 5Y).

(Example 1)
As the first embodiment, after the auxiliary heater 4C was operated in advance, the direct heater 4A and the direct heater 4B were operated, and the inner wall cooler 5X and the mounting table cooler 5Y were appropriately operated. The operation of the decompression device and the pressurizing device was started at the same time as the operation of the direct heater 4A and the direct heater 4B was started. After a lapse of a certain period of time at the molding temperature (130 ° C.), the heaters 4A to 4C were stopped, the decompression device and the pressurizing device were stopped, and only the inner wall cooler 5X and the mounting table cooler 5Y were operated.

FIG. 7 shows the upper temperature of the molding material (fiber reinforced plastic material 101), the lower temperature of the molding material, the internal space temperature of the pressure vessel, and the pressure inside the pressure vessel when Example 1 was performed. As shown in the figure, the surface temperature of the upper part and the lower part of the molding material could be kept uniform.

(Example 2)
Example 2 is an example in which the auxiliary heater 4C is operated after the direct heater 4A and the direct heater 4B are operated.

FIG. 8 shows the upper temperature of the molding material, the lower temperature of the molding material, the internal space temperature of the pressure vessel, and the measured pressure in the pressure vessel when the second embodiment was performed. As shown in the figure, the surface temperatures of the upper part and the lower part of the molding material were kept substantially uniform, although the difference was slightly larger than that of Example 1.

(Comparative Example 1)
As Comparative Example 1, only the direct heater 4A and the direct heater 4B were operated, and the auxiliary heater 4C and the coolers 5X and 5Y were stopped to perform the measurement.

FIG. 9 shows the upper temperature of the molding material, the lower temperature of the molding material, and the measured pressure in the pressure vessel when the measurement of Comparative Example 1 was performed. As shown in the figure, the difference in surface temperature between the upper part and the lower part of the molding material became large. In addition, an overshoot occurred. It is thought that this is because he heats a lot to supplement the amount of his heat being taken away. The temperature difference opened at this time is open until later.

[Temperature control experiment: Example 3, Comparative Example 2]
The fiber reinforced plastic molding apparatus 1 shown in FIG. 1 was prototyped. It includes direct heaters 4A and 4B, auxiliary heaters 4C, inner wall coolers 5X, mount coolers 5Y, and molded coolers 5Z. The arrangement of the auxiliary heater 4D is omitted. Further, the arrangement of temperature sensors other than the target temperature sensors 31 and 32 and the internal space temperature sensor 33 is omitted. Further, as the direct heaters 4A and 4B, those arranged inside the vacuum bag 103 as shown in FIG. 3B were used. The difference from Examples 1 and 2 is that the molded cooler 5Z was provided and operated. A mold made of aluminum was used as the molding mold 102. As the member 101 to be heat-treated, a prepreg using an epoxy resin was used. The target temperature (molding temperature) is 130 ° C. The molding schedule was room temperature → 80 ° C. → 90 ° C. → 130 ° C. → room temperature (water cooling of the inner wall cooler 5X, the mounting table cooler 5Y, and the molding type cooler 5Z).

(Example 3)
As the third embodiment, after the auxiliary heater 4C was operated in advance, the direct heater 4A and the direct heater 4B were operated, and the inner wall cooler 5X, the mounting table cooler 5Y, and the molded cooler 5Z were appropriately operated. .. The operation of the depressurizing device 11 and the pressurizing device 14 was started at the same time as the operation of the direct heater 4A and the direct heater 4B was started. After a certain period of time has elapsed at the molding temperature (130 ° C.), the direct heaters 4A and 4B and the auxiliary heater 4C are stopped, and the depressurizing device 11 and the pressurizing device 14 are stopped to stop the inner wall cooler 5X and the mounting table cooler 5Y. , The molded cooler 5Z was operated.

FIG. 10 shows the upper temperature of the molding material (prepreg 101), the lower temperature of the molding material, the internal space temperature of the pressure vessel, and the measured pressure inside the pressure vessel when Example 3 was performed. As shown in the figure, the surface temperatures of the upper part and the lower part of the molding material could be heat-treated at almost the same temperature.

(Comparative Example 2)
As Comparative Example 2, the direct heater 4A and the direct heater 4B were operated, and the measurement was performed without operating the auxiliary heater 4C. The inner wall cooler 5X and the mounting table cooler 5Y were operated as appropriate.

FIG. 11 shows the upper temperature of the molding material, the lower temperature of the molding material, and the measured pressure in the pressure vessel when Comparative Example 2 was performed. As shown in the figure, the difference in surface temperature between the upper part and the lower part of the molding material became large. In addition, an overshoot occurred. It is thought that this is because he heats a lot to supplement the amount of his heat being taken away. The temperature difference opened at this time is open until later.

[Temperature control experiment: Examples 4 to 8, Comparative Example 3, Reference Example 1]
An experiment was conducted with the same configuration as in Example 3. The target temperature (molding temperature) is 130 ° C. The molding schedule was room temperature → 80 ° C. → 90 ° C. → 130 ° C. → room temperature (water cooling of the inner wall cooler 5X, the mounting table cooler 5Y, and the molding type cooler 5Z). The operation of the inner wall cooler 5X, the mounting table cooler 5Y, and the molded cooler 5Z was appropriately controlled.

(Comparative Example 3)
The measurement was performed by directly operating the heaters 4A and 4B and without operating the auxiliary heater 4C. The measurement results are shown in FIG.

(Example 4)
The direct heaters 4A and 4B and the auxiliary heaters 4C were started to operate at the same time. The internal space temperature of the pressure vessel 2 was controlled to be 30% (39 ° C.) of the target temperature (130 ° C.). The measurement result is shown in FIG.

(Example 5)
The direct heaters 4A and 4B and the auxiliary heaters 4C were started to operate at the same time. The internal space temperature of the pressure vessel 2 was controlled to be 40% (52 ° C) of the target temperature (130 ° C). The measurement result is shown in FIG.

In Examples 4 and 5, the upper temperature (CH2) of the member 101 to be heat-treated had a large overshoot, but was slightly improved as compared with Comparative Example 3. It is considered that the overshoot of the upper temperature (CH2) is due to the heat of the heater 4A being diffused directly into the internal space of the pressure vessel 2.

(Example 6)
After the auxiliary heater 4C was operated first, the heaters 4A and 4B were directly operated. The internal space temperature of the pressure vessel 2 was controlled to be 50% (65 ° C.) of the target temperature (130 ° C.). The measurement result is shown in FIG. The lower side temperature (CH1) and the upper side temperature (CH2) of the member 101 to be heat-treated are stable at almost the same temperature at 80 ° C. → 90 ° C. → 130 ° C., although there is a slight difference in the waveform when the temperature rises up to 80 ° C. I was able to heat it. From 130 ° C. to room temperature, the difference between the lower side temperature and the upper side temperature was small as compared with Examples 4 and 5, and the temperature was stably lowered.

(Example 7)
The auxiliary heaters 4C were operated first, and then the heaters 4A and 4B were directly operated. The internal space temperature of the pressure vessel 2 was controlled to be 60% (78 ° C.) of the target temperature (130 ° C.). The measurement result is shown in FIG. Compared with Example 6, the difference between the lower temperature and the upper temperature was smaller and the temperature was almost the same.

(Example 8)
The auxiliary heaters 4C were operated first, and then the heaters 4A and 4B were directly operated. The internal space temperature of the pressure vessel 2 was controlled to be 80% (104 ° C.) of the target temperature (130 ° C.). The measurement result is shown in FIG. Compared with Example 7, the difference between the lower temperature and the upper temperature was even smaller, and the temperatures were almost the same.

(Reference example 1)
The auxiliary heaters 4C were operated first, and then the heaters 4A and 4B were directly operated. The internal space temperature of the pressure vessel 2 was controlled to be 100% (130 ° C.) of the target temperature (130 ° C.). The measurement result is shown in FIG. Compared with Example 7, the difference between the lower temperature and the upper temperature was even smaller, and the temperatures were almost the same. However, it consumes a lot of energy.

From the above results, it can be said that it is preferable to control the internal space temperature of the pressure vessel 2 to a predetermined temperature of 50% to 80% of the target temperature.

[Temperature control experiment when only one direct heater is arranged: Example 9]
(Example 9)
The fiber reinforced plastic molding apparatus 1 shown in FIG. 1 was prototyped. However, instead of arranging the direct heater 4B, only one direct heater 4A was arranged on the upper side of the member 101 to be heat-treated and inside the vacuum bag 103 as shown in FIG. 3 (b). It is provided with a direct heater 4A, an auxiliary heater 4C, an inner wall cooler 5X, and a mounting table cooler 5Y. The arrangement of the molded cooler 5Z and the auxiliary heater 4D was omitted. Further, the arrangement of temperature sensors other than the target temperature sensors 31 and 32 and the internal space temperature sensor 33 is omitted. As the member 101 to be heat-treated, a prepreg using an epoxy resin was used. As the molding die 102, one made of pearl board block (gypsum board) was used. The target temperature (molding temperature) is 130 ° C. The molding schedule was room temperature → 80 ° C. → 90 ° C. → 130 ° C. → room temperature (water cooling of the inner wall cooler 5X and the mounting table cooler 5Y). The internal space temperature of the pressure vessel 2 was controlled to be 60% (78 ° C.) of the target temperature (130 ° C.). The operation of the inner wall cooler 5X and the mounting table cooler 5Y was appropriately controlled.

The measurement result is shown in FIG. At the time of heating, the upper part and the lower part of the member 101 to be heat-treated could be heated with almost no temperature difference. There was a slight temperature difference during cooling.

1 is a heat treatment device (fiber reinforced plastic molding device), 2 is a pressure vessel, 2a is an opening / closing door, 3 is a mounting table, 4A is a first direct heater, 4B is a second direct heater, and 4C is a first. Auxiliary heater, 4D is the second auxiliary heater, 5X is the inner wall cooler (cooling pipe), 5Y is the mounting base cooler (cooling pipe), 5Z is the molded cooler (cooling pipe), 6.6a, 6b 6c and 6d are heat treatment blocks, 8 is a control unit, 11 is a decompression device, 12 is a vacuum pump, 13 is a pipe, 14 is a pressurizing device, 15 is a compressor, 16 is a pipe, 21 is a cooling source, and 22 is a cooling source. , 23 is a cooling source, 31 is a first target temperature sensor, 32 is a second target temperature sensor, 33 is an internal space temperature sensor, 34 is a mounting table temperature sensor, 41A is a first direct heater temperature sensor, 41B. Is the second direct heater temperature sensor, 41C is the first auxiliary heater temperature sensor, 41D is the second auxiliary heater temperature sensor, 41X is the inner wall cooler temperature sensor, 41Y is the mount cooler temperature sensor, 41Z. Is a molded cooler temperature sensor, 101 is a member to be heat-treated (prepreg), 102, 102a, 102b are molded molds, 103 is a vacuum bag,
111a and 111b are members to be adhered, 112 is an adhesive member, 121 is a liquid, 131 is a cylinder, 132 is a piston, and 135 is a filter.

Claims (18)

Direct heater is to directly heat the thermally treated member, the then placed into contact via the auxiliary materials to the arrangement or the thermally treated member so as to contact with a thermal treatment member, wherein the heat treatment An auxiliary heater for heating the internal space of the container for accommodating the members is arranged, an inner wall cooler for cooling the inner wall of the container is arranged, and a mounting table cooler for cooling the mounting table on which the heat-treated member is placed is provided. An internal space temperature sensor for measuring the internal space temperature of the container is arranged, and a plurality of target temperature sensors for measuring the temperature of a plurality of parts of the heat-treated member are arranged.
The direct heater is heated so that the internal space temperature is lower than the target temperature that is the heating target of the member to be heat-treated, and the temperature detected by the plurality of target temperature sensors is the target temperature. A heat treatment method comprising controlling the auxiliary heater, the inner wall cooler, and the above-mentioned stand cooler to perform heat treatment of the member to be heat-treated. The heat treatment method according to claim 1, wherein when the heat treatment is started, the auxiliary heater is first operated and then the direct heater is operated. The member to be heat-treated is a fiber-reinforced plastic material containing a thermosetting resin or a thermoplastic resin, and the fiber-reinforced plastic material and a molding mold for molding the fiber-reinforced plastic material are housed in a vacuum bag, and the vacuum bag is vacuumed. The heat treatment method according to claim 1 or 2, wherein the inside of the container is pressurized to perform autoclave molding. The direct heater, the auxiliary heater, the inner wall cooler, and the above description are provided so that a mold cooler for cooling the mold is arranged so that the temperature detected by the plurality of target temperature sensors becomes the target temperature. The heat treatment method according to claim 3, wherein the stand cooler and the molded cooler are controlled. Controlling the auxiliary heater and the inner wall cooler so that the internal space temperature becomes a predetermined temperature within the range of 50% to 80% of the target temperature when the target temperature is expressed in degrees Celsius. The heat treatment method according to any one of claims 1 to 4. At the start of the heat treatment, after the auxiliary heater is operated first, the operation of the direct heater is started after the internal space temperature becomes a temperature within the range of 30% to 80% of the target temperature. The heat treatment method according to any one of claims 1 to 5. The heat treatment method according to any one of claims 1 to 6, wherein a plurality of heaters whose temperature can be controlled independently are arranged as the direct heater. The heat treatment method according to any one of claims 1 to 7, wherein the auxiliary heater is arranged below the member to be heat-treated. The heat treatment method according to any one of claims 1 to 8, wherein as the inner wall cooler, a spirally formed cooling pipe is arranged so as to be in contact with the inner wall of the container. A container for accommodating members to be heat-treated and
A mounting table on which the heat-treated member is placed and
The be one which directly heating the heat treatment member, the placed into contact via the auxiliary materials in the arranged or said to be thermally member so as to contact with a thermal treatment member, directly heater When,
An auxiliary heater that heats the internal space of the container,
An inner wall cooler that cools the inner wall of the container,
A stand cooler that cools the stand described above,
A plurality of target temperature sensors for measuring the temperature of a plurality of points of the member to be heat-treated, and a plurality of target temperature sensors.
An internal space temperature sensor that measures the internal space temperature of the container,
The direct heater is heated so that the internal space temperature is lower than the target temperature that is the heating target of the member to be heat-treated, and the temperature detected by the plurality of target temperature sensors is the target temperature. A heat treatment apparatus comprising the auxiliary heater, the inner wall cooler, and a control unit for controlling the above-mentioned stand cooler, and performing heat treatment of the member to be heat-treated. The heat treatment apparatus according to claim 10, wherein the control unit operates the auxiliary heater first and then the direct heater at the start of heat treatment. The member to be heat-treated is a fiber-reinforced plastic material containing a thermosetting resin or a thermoplastic resin, and the fiber-reinforced plastic material and a molding mold for molding the fiber-reinforced plastic material are housed in a vacuum bag, and the vacuum bag is vacuumed. The heat treatment apparatus according to claim 10 or 11, further comprising an apparatus and a pressurizing apparatus for pressurizing the inside of the container, and being configured to enable autoclave molding of the fiber reinforced plastic material. The direct heater, the auxiliary heater, and the control unit are provided with a mold cooler for cooling the mold so that the temperature detected by the plurality of target temperature sensors reaches the target temperature. The heat treatment apparatus according to claim 12, wherein the inner wall cooler, the above-mentioned stand cooler, and the molded cooler are controlled. The auxiliary heater and the inner wall cooling so that the control unit makes the internal space temperature a predetermined temperature within the range of 50% to 80% of the target temperature when the target temperature is expressed in degrees Celsius. The heat treatment apparatus according to any one of claims 10 to 13, wherein the device is controlled. At the start of the heat treatment, the control unit first operates the auxiliary heater, and then the internal space temperature becomes a temperature within the range of 30% to 80% of the target temperature, and then the direct heater. The heat treatment apparatus according to any one of claims 10 to 14, wherein the operation of the heat treatment apparatus is started. The heat treatment apparatus according to any one of claims 10 to 15, wherein a plurality of heaters whose temperature can be controlled independently are arranged as the direct heater. The heat treatment apparatus according to any one of claims 10 to 16, wherein the auxiliary heater is arranged below the member to be heat-treated. The heat treatment apparatus according to any one of claims 10 to 17, wherein a cooling pipe formed spirally so as to be in contact with the inner wall of the container is arranged as the inner wall cooler.

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