Radiation heating autoclave device

Abstract

The invention discloses a radiation heating autoclave device which comprises a tank body, and a curing bin is formed in the middle of the inner side of the tank body; the transparent mold is made of a transparent material and used for bearing the prepreg to be cured and formed, and the transparent mold has transmissivity to radiation energy, so that the radiation energy can penetrate through the transparent mold and irradiate the surface of the prepreg; the trolley is arranged in the curing bin and used for bearing the transparent mold; the radiation heating module is used for radiating and outputting energy into the curing bin so as to heat and cure the prepreg; the temperature measuring module is used for acquiring temperature information near the prepreg when the prepreg is heated and cured; and the temperature feedback regulation module is used for regulating the output power of the radiation heating module based on the temperature information near the prepreg. Through cooperation of radiation heating and the transparent mold, the prepreg heating and curing efficiency is improved, the temperature control effect is improved, and therefore the production efficiency of the autoclave forming process is improved.

Description

Technical Field

[0001] This invention relates to the field of autoclave technology, and more particularly to a radiation-heated autoclave device. Background Technology

[0002] Autoclave molding technology can generate uniform thermal and pressure fields, enabling the manufacture of high-performance, structurally complex carbon fiber composite components. It is a top-tier manufacturing process for high-end composite components, especially key components in the aerospace field. Common autoclave structures include... Figure 5 As shown, a fan drives the gas flow inside the autoclave. The gas is heated by heating wires and then convects with the mold and prepreg. Because the metal mold and the autoclave itself have a large heat capacity, the gas inside the autoclave heats up very slowly, and the efficiency of convective heat transfer is relatively low. Typically, a prepreg heating and curing cycle takes several hours. After curing, waiting for the heavy metal mold to cool also takes a long time. These factors result in very low production efficiency for the autoclave molding process. Summary of the Invention

[0003] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, one objective of this invention is to provide a radiant heating autoclave device, which, through the combination of radiant heating and a transparent mold, improves the heating and curing efficiency of prepregs and enhances temperature control, thereby increasing the production efficiency of the autoclave molding process.

[0004] A radiation-heated autoclave device according to the present invention comprises:

[0005] The tank body has a curing chamber in the middle of its inner side, and a tank door is provided on one side of the tank body located in the curing chamber;

[0006] A transparent mold, made of transparent material, is used to hold the prepreg to be cured and molded, and the transparent mold is transmissive to radiant energy, so that radiant energy can pass through the transparent mold and irradiate the surface of the prepreg;

[0007] A trolley is placed inside the curing chamber and is used to carry the transparent mold. The trolley has a mesh bearing surface, and the pore area of ​​the mesh bearing surface accounts for more than 90%.

[0008] A radiant heating module is arranged in a ring along the inner wall of the curing chamber, and is used to radiate energy into the curing chamber to heat and cure the prepreg.

[0009] The temperature measurement module is connected to multiple thermocouples to obtain temperature information near the prepreg during the heating and curing process.

[0010] The temperature feedback adjustment module has its signal input terminal and signal output terminal connected to the signal output terminal of the temperature measurement module and the signal input terminal of the radiant heating module, respectively. The temperature feedback adjustment module is used to adjust the output power of the radiant heating module based on the temperature information near the prepreg.

[0011] Preferably, the inner wall of the curing chamber is provided with a reflective layer, which is used to reflect radiant energy so that the energy is focused on the surface of the prepreg to be heated and cured.

[0012] Preferably, the radiant heating module includes a quartz lamp radiation array formed by multiple sets of quartz lamps uniformly arranged along the inner wall of the curing chamber.

[0013] Preferably, the temperature feedback adjustment module uses a PID control algorithm to adjust the output power of the radiant heating module, and the PID control algorithm adjustment formula is:

[0014] ;

[0015] in, This is the output of the nth control cycle. , , These are the proportional coefficient, integral coefficient, and differential coefficient, respectively. This is the temperature error value for the nth control cycle, which is the set temperature minus the current temperature.

[0016] Preferably, the transparent mold is made of polyetherimide (PEI) material, which has low heat capacity and high light transmittance.

[0017] Preferably, the bottom inner side of the curing chamber is provided with a slide rail from the tank door toward the curing chamber, the trolley is mounted on the slide rail, and the trolley can move along the slide rail.

[0018] Preferably, a centrifugal fan is installed inside the tank on the side away from the tank door, an air duct is provided between the inner wall of the curing chamber and the tank, the air duct inlet is located on the side near the centrifugal fan, the air duct outlet is located on the side near the tank door, and a grid is provided between the curing chamber and the centrifugal fan.

[0019] Preferably, the reflective layer is an aluminum high-reflectivity coating.

[0020] The beneficial effects of this invention are:

[0021] High heating efficiency and shorter curing cycle: The prepreg is heated and cured by radiation, which can concentrate energy on the target area more effectively than convection heat transfer, thus improving heating efficiency and shortening the process cycle.

[0022] Radiation can pass through the transparent mold to reach the prepreg directly: The transparent mold is transparent to radiation energy, allowing radiation energy to pass through the mold and irradiate the surface of the prepreg, which helps to increase the heating rate.

[0023] Higher energy efficiency and less heat loss: The inner wall of the curing chamber is equipped with a reflective layer to reflect radiant energy and direct the energy toward the prepreg area, reducing ineffective heat absorption and energy loss caused by the tank and internal gases.

[0024] More uniform heating and better temperature control: Temperature information is collected by multiple thermocouples, and the output power of the radiation heating module is adjusted by the temperature feedback adjustment module, which can improve the temperature control effect and facilitate stable curing.

[0025] The radiation path is smoother and the loading and unloading is more convenient: the mesh bearing area of ​​the trolley has a ratio of more than 90%, which makes it easier for the bottom and circumferential radiation to reach the mold and prepreg area; at the same time, the bottom of the curing chamber is equipped with a sliding rail to facilitate the trolley to enter and exit quickly and reduce loading and unloading time. Attached Figure Description

[0026] In the attached diagram:

[0027] Figure 1 This is a side cross-sectional view of the radiant heating autoclave device proposed in this invention;

[0028] Figure 2 This is a front cross-sectional view of the interior of the radiant heating autoclave device proposed in this invention;

[0029] Figure 3 This is a top view of the trolley proposed in this invention inside the autoclave;

[0030] Figure 4 This is a flowchart illustrating the prepreg heating and curing process proposed in this invention.

[0031] Figure 5 This is a schematic diagram of the structure of a common autoclave.

[0032] Figure 6 This is a schematic diagram of the geometric structure of a common convection autoclave simulation model;

[0033] Figure 7 This is a schematic diagram of the geometric structure of the simulation model of the radiative autoclave proposed in this invention;

[0034] Figure 8 The figures show the temperature rise curves of the prepreg center in the two autoclave simulation models proposed in this invention. Detailed Implementation

[0035] Reference Figure 1 A radiant heating autoclave device, comprising:

[0036] The tank body has a curing chamber in the middle of its inner side, and a tank door is provided on one side of the tank body located in the curing chamber;

[0037] A transparent mold, made of transparent material, is used to hold the prepreg to be cured and molded, and the transparent mold is transmissive to radiant energy, so that radiant energy can pass through the transparent mold and irradiate the surface of the prepreg;

[0038] A trolley, positioned within the curing chamber and used to carry the transparent mold, is described below. Figure 3 The trolley has a grid bearing surface, and the pore area of ​​the grid bearing surface accounts for more than 90%.

[0039] A radiant heating module is arranged in a ring along the inner wall of the curing chamber, and is used to radiate energy into the curing chamber to heat and cure the prepreg.

[0040] The temperature measurement module is connected to multiple thermocouples to obtain temperature information near the prepreg during the heating and curing process.

[0041] The temperature feedback adjustment module has its signal input terminal and signal output terminal connected to the signal output terminal of the temperature measurement module and the signal input terminal of the radiant heating module, respectively. The temperature feedback adjustment module is used to adjust the output power of the radiant heating module based on the temperature information near the prepreg.

[0042] Obviously, based on the above: after laying the prepreg to be cured onto the transparent mold and completing the vacuum bag sealing, the transparent mold is placed on the grid support surface of the trolley, and the trolley is pushed into the curing chamber through the tank door; the radiation heating module is activated to radiate energy into the curing chamber, and the radiation energy acts directly on the transparent mold in the curing chamber and can shine through the transparent mold onto the surface of the prepreg, so that the prepreg obtains the required heating and heat preservation curing conditions; during the heating and curing process, the temperature measurement module obtains the temperature information near the prepreg in real time through multiple thermocouples and outputs it to the temperature feedback adjustment module. The temperature feedback adjustment module performs closed-loop adjustment of the output power of the radiation heating module based on the temperature information, so that the temperature change of the prepreg is more in line with the curing process requirements and improves the temperature uniformity; after curing, the tank door is opened, the trolley and the transparent mold are removed from the curing chamber, and demolding and post-processing are performed. Therefore, this embodiment utilizes the synergistic combination of radiant heating, transparent mold transmission, grid carriage through-path, and closed-loop temperature regulation to more effectively transfer radiant energy to the prepreg area. Compared with the traditional autoclave heating method that mainly relies on convection heat transfer, it can improve the prepreg heating and curing efficiency, shorten the curing cycle, and enhance temperature controllability through multi-point temperature measurement and feedback adjustment, thereby improving the overall production efficiency of the autoclave molding process.

[0043] In this embodiment, refer to Figure 3The inner wall of the curing chamber is provided with a reflective layer, which is used to reflect radiation energy so that the energy is focused on the surface of the prepreg to be heated and cured.

[0044] Specifically, the reflective layer can be made of aluminum with a high reflectivity coating.

[0045] Obviously, based on the above: when the radiant heating module radiates energy into the curing chamber along the inner wall to heat and cure the prepreg, the reflective layer on the inner wall of the curing chamber simultaneously reflects the radiant energy, causing the radiant energy to be reflected multiple times within the curing chamber and converge towards the transparent mold and the area where the prepreg is located. This allows the energy to act more concentratedly on the surface of the prepreg to be heated and cured. When the reflective layer uses an aluminum high-reflectivity coating, the ineffective loss caused by the absorption of radiant energy by the inner wall of the curing chamber can be reduced, improving the effective utilization rate of radiant energy within the curing chamber. Therefore, this embodiment, through the combination of the radiant heating module and the aluminum high-reflectivity coating, achieves energy focusing and more stable heat input to the surface of the prepreg, which is beneficial for improving heating and curing efficiency, shortening the heating and curing process time, and thus improving the production efficiency and product molding quality of the autoclave molding process.

[0046] In this embodiment, the radiant heating module includes a quartz lamp radiation array formed by multiple sets of quartz lamps uniformly arranged along the inner wall of the curing chamber.

[0047] Clearly, based on the above, the radiant heating module employs a quartz lamp radiation array formed by multiple sets of quartz lamps evenly arranged along the inner wall of the curing chamber. This results in a more uniform circumferential distribution of the radiant heat source within the curing chamber, creating a more balanced radiant energy field during the heating and curing of the prepreg. This reduces the risk of localized overheating or underheating caused by a single heat source or localized arrangement. Simultaneously, the multiple sets of quartz lamps, acting as independent radiation units, facilitate the distribution and adjustment of heat input to different areas through temperature measurement and feedback, thereby improving the temperature controllability and stability of the curing process. Therefore, this embodiment, through the uniform arrangement of the quartz lamp radiation array, improves the uniformity of heating on the prepreg surface, increases heating and curing efficiency, and contributes to improving the curing quality and molding consistency of the finished product.

[0048] In this embodiment, the temperature feedback adjustment module uses a PID control algorithm to adjust the output power of the radiant heating module. The PID control algorithm adjustment formula is as follows:

[0049] ;

[0050] in, This is the output of the nth control cycle. , , These are the proportional coefficient, integral coefficient, and differential coefficient, respectively. This is the temperature error value for the nth control cycle, which is the set temperature minus the current temperature.

[0051] Clearly, based on the above, the temperature feedback adjustment module, using a PID control algorithm, can achieve more stable temperature tracking and better dynamic adjustment performance during the prepreg heating and curing process, reducing temperature fluctuations and overshoot risks, and improving the temperature controllability and consistency of the curing process, thereby improving the curing quality and process stability of the product.

[0052] In this embodiment, the transparent mold may be made of polyetherimide (PEI) material, which has low heat capacity and high light transmittance.

[0053] Clearly, based on the above, the transparent mold, made of PEI material, not only meets the structural load-bearing requirements during the prepreg laying and curing process, but also, due to its light-transmitting properties, allows the radiant energy output from the radiant heating module to directly act on the prepreg surface, thereby reducing ineffective losses caused by the mold blocking or absorbing radiant energy and improving the effective heating effect on the prepreg. Simultaneously, the mold's low heat capacity means it absorbs and releases less heat during heating and cooling, which helps reduce the thermal inertia effect during curing. This, in turn, improves the heating response speed and shortens non-production time related to heating and cooling while ensuring controllable curing temperature. Therefore, this embodiment, by using a PEI transparent mold, makes the energy transfer of radiant heating more efficient and the temperature response faster, which is beneficial for improving the heating and curing efficiency of the prepreg and increasing the production cycle of the molding process.

[0054] In this embodiment, a slide rail is provided on the inner bottom of the curing chamber from the tank door toward the curing chamber, the trolley is mounted on the slide rail, and the trolley can move along the slide rail.

[0055] Clearly, based on the above, the trolley, positioned on and able to move along the slide rails, allows the transparent mold and the prepreg it carries to be positioned and transferred via sliding during canning and unloading. This reduces the operational difficulty and errors caused by manual lifting, handling, and repeated alignment. Simultaneously, the slide rails guide and limit the trolley's movement, ensuring smoother entry and exit from the curing chamber and reducing the risk of displacement, collision, or vibration of the mold and prepreg during movement. Therefore, this structure improves loading and unloading efficiency and shortens the non-productive time spent on loading and unloading.

[0056] In this embodiment, a centrifugal fan is installed inside the tank on the side away from the tank door. An air duct is provided between the inner wall of the curing chamber and the tank. The air duct inlet is located on the side close to the centrifugal fan, and the air duct outlet is located on the side close to the tank door. A grid is provided between the curing chamber and the centrifugal fan.

[0057] Specifically, the motor of the centrifugal fan is installed on the outside of the tank.

[0058] Obviously, based on the above: gas enters the duct through the inlet near the centrifugal fan and is transported along the duct to the outlet near the tank door, then flows back into the curing chamber, thus forming a stable circulating airflow within the curing chamber. This circulating airflow promotes the homogenization of the temperature field within the curing chamber, reducing the risk of temperature unevenness caused by local heat accumulation or temperature differences. It also helps to remove excess heat from localized areas, creating a more stable thermal environment in conjunction with radiant heating, thereby improving the process stability of the curing process and the consistency of the product molding. Simultaneously, the partition between the curing chamber and the centrifugal fan isolates and protects the flow field entering the fan area. Furthermore, mounting the centrifugal fan motor on the outside of the tank reduces the heat load and sealing difficulty of the motor under high temperature and high pressure, extends motor life, and facilitates maintenance.

[0059] As another embodiment of this application, this embodiment proposes a working method for prepreg heating and curing, referring to... Figure 4 First, the prepreg is pretreated by manually laying it in the PEI mold, followed by a release liner, release film, and breathable felt. A vacuum bag is then used to wrap the mold surface and the prepreg, and sealed with high-temperature adhesive. A vacuum nozzle is installed on the vacuum bag. Next, the tank door is opened, and a trolley is moved along a slide rail to the outside of the tank. The prepared vacuum bag system is placed on the trolley, and the trolley is moved until the vacuum bag system is centered in the curing chamber. The vacuum pipe inside the tank is connected to the vacuum nozzle of the vacuum bag system. The thermocouples of the thermocouple temperature measurement module are attached to the upper surface of the vacuum bag and inserted into key temperature measurement points such as the bottom of the mold through pre-reserved temperature measurement holes. Finally, the tank door is closed, and the inside of the vacuum bag system is evacuated through the vacuum pipe. Depending on the process requirements of different prepregs, high-pressure air is injected into the tank until the internal pressure reaches 0.5-1 MPa. Furthermore, the fan at the rear of the tank operates, and the radiant heating module operates, with the temperature range varying from 120-200℃ depending on the process requirements of different prepregs, heating the vacuum bag system through radiation. A thermocouple temperature measurement module continuously monitors the temperature at the measuring points of the vacuum bag system, and the temperature feedback adjustment module adjusts the radiation intensity of the quartz lamp array based on the temperature data. Further, when the temperature at the measuring point reaches the designated prepreg curing temperature, the quartz lamp array is adjusted to maintain that curing temperature. Further, after curing, the high-pressure gas inside the tank is discharged, the tank door is opened, and the trolley is moved outside the tank to allow the mold to cool. Further, the mold is opened, and the finished product undergoes post-processing such as polishing, grinding, and cutting.

[0060] To more clearly illustrate the solution and effects of this embodiment, further examples will be provided in conjunction with the accompanying drawings:

[0061] The heating effect of this embodiment was numerically simulated and calculated using simulation software, and the results were respectively... Figure 5 The commonly seen autoclaves shown are Figure 1 The radiant autoclave shown is used for simulation. The autoclave body has a diameter of 1m and a height of 2.3m, while the curing chamber has a diameter of 0.9m and a height of 2m. A 40cm × 40cm × 10cm cuboid mold is located at the center of the autoclave body, and a 40cm × 40cm × 1cm cuboid prepreg is placed above the mold. For commonly used autoclaves, the heating element is located in the air duct between the outer wall of the autoclave and the curing chamber, such as... Figure 6 As shown. The thermal conductivity of the prepreg is 2 W / (m·K), and its density is 1500 kg / m³. 3 The specific heat capacity at constant pressure is 1500 J / (kg·K), and the emissivity is 0.8. The thermal properties of the metal mold are referenced from No. 45 steel, with a thermal conductivity of 51.9 W / (m·K) and a density of 7817 kg / m³. 3 The specific heat capacity at constant pressure is 446 J / (kg·K). The emissivity of the tube wall and metal mold surface is taken as 0.25, referencing stainless steel with a stable oxide layer. The emissivity of the heating element surface is taken as 0.5. For the radiant autoclave proposed in this invention, the heating element is located inside the curing chamber, such as... Figure 7 As shown. The thermal properties of the mold are referenced to PEI material, with a thermal conductivity of 0.26 W / (m·K) and a density of 1270 kg / m³. 3 The specific heat capacity at constant pressure is 1200 J / (kg·K). The emissivity of the inner wall of the curing chamber is taken as 0.05, referencing mirror-finished aluminum. The surface emissivity of the radiant lamp is taken as 0.9. The total power is 10000 W for both heating modes. The outer wall of the autoclave is considered as an insulating wall. The temperature change at the very center of the prepreg is calculated and monitored. The results are as follows: Figure 8 As shown, with the heating time cut off at 440K, the radiant heating autoclave took 1280s, while the convection heating autoclave took 2180s, reducing the heating time by 41.3%.

Claims

1. A radiant heating autoclave device, characterized in that, include: The tank body has a curing chamber in the middle of its inner side, and a tank door is provided on one side of the tank body located in the curing chamber; A transparent mold, made of transparent material, is used to hold the prepreg to be cured and molded, and the transparent mold is transmissive to radiant energy, so that radiant energy can pass through the transparent mold and irradiate the surface of the prepreg; A trolley is placed inside the curing chamber and is used to carry the transparent mold. The trolley has a mesh bearing surface, and the pore area of ​​the mesh bearing surface accounts for more than 90%. A radiant heating module is arranged in a ring along the inner wall of the curing chamber, and is used to radiate energy into the curing chamber to heat and cure the prepreg. The temperature measurement module is connected to multiple thermocouples to obtain temperature information near the prepreg during the heating and curing process. The temperature feedback adjustment module has its signal input terminal and signal output terminal connected to the signal output terminal of the temperature measurement module and the signal input terminal of the radiant heating module, respectively. The temperature feedback adjustment module is used to adjust the output power of the radiant heating module based on the temperature information near the prepreg.

2. The radiant heating autoclave device according to claim 1, characterized in that: The inner wall of the curing chamber is provided with a reflective layer, which is used to reflect radiation energy so that the energy is focused on the surface of the prepreg to be heated and cured.

3. The radiant heating autoclave device according to claim 1, characterized in that: The radiant heating module includes a quartz lamp radiation array formed by multiple sets of quartz lamps evenly arranged along the inner wall of the curing chamber.

4. The radiant heating autoclave device according to claim 1, characterized in that: The temperature feedback regulation module uses a PID control algorithm to regulate the output power of the radiant heating module. The PID control algorithm adjustment formula is as follows: ； in, This is the output of the nth control cycle. , , These are the proportional coefficient, integral coefficient, and differential coefficient, respectively. This is the temperature error value for the nth control cycle, which is the set temperature minus the current temperature.

5. The radiant heating autoclave device according to claim 1, characterized in that: The transparent mold is made of polyetherimide (PEI) material, which has low heat capacity and high light transmittance.

6. The radiant heating autoclave device according to claim 1, characterized in that: The bottom inner side of the curing chamber is provided with a slide rail from the tank door toward the curing chamber. The trolley is mounted on the slide rail and can move along the slide rail.

7. The radiant heating autoclave device according to claim 1, characterized in that: A centrifugal fan is installed inside the tank on the side away from the tank door. An air duct is provided between the inner wall of the curing chamber and the tank. The air duct inlet is located on the side close to the centrifugal fan, and the air duct outlet is located on the side close to the tank door. A grid is provided between the curing chamber and the centrifugal fan.

8. The radiant heating autoclave device according to claim 2, characterized in that: The reflective layer is an aluminum high-reflectivity coating.

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