Temperature control method and system for pultrusion die

Abstract

The present invention relates to the field of preparation of composite materials, in particular to a temperature control method and system for a pultrusion die. The method of the present invention fits corresponding temperature rise and curing curves to different types of materials to be cured, and uses the temperature rise and curing curves to divide different heating areas on the pultrusion die. The temperature of the different heating areas is controlled to achieve precise control of the temperature of each heating section during the dynamic curing process of the composite material. Furthermore, by obtaining the internal and external temperature transfer model of an unloaded pultrusion die during heating and optimizing the temperature transfer model of the corresponding heating section, measurement errors caused by the pultrusion die's inability to collect internal temperature and internal and external temperature transfer efficiency are eliminated. At the same time, the optimized temperature transfer model is used to adjust the heating power of the current heating section in real time to prevent the actual temperature from being greater than the set temperature, thereby greatly improving the accuracy of curing temperature control in the pultrusion die.

Description

Technical Field

[0001] The present invention relates to the field of preparation of composite materials, and in particular to a temperature control method and system for a pultrusion die. Background Art

[0002] Pultrusion is one of the most commonly used methods in the production and preparation of composite components. It boasts advantages such as high automation, high productivity, low labor costs, precise cross-sectional dimensions, and smooth surfaces. Pultrusion primarily involves the following steps: fiber placement, resin impregnation, preforming, extrusion molding, curing, pulling, cutting, and final product. The core technical steps in the pultrusion process are extrusion molding and curing within the pultrusion die: reinforcement and resin are moved forward at a constant speed within the pultrusion die, and the resin is cured by heating the die, thereby achieving pultrusion production of the composite material. Precise temperature control within the pultrusion die during resin curing directly impacts the appearance and performance of the resulting composite material. Therefore, precise temperature control within the pultrusion die is essential in pultrusion technology. Existing pultrusion die temperature control is inaccurate, resulting in excessively long heating times and increased heating power. This increased heating power not only wastes energy but also causes the pultrusion die heating system to exceed the set temperature after reaching it. At the same time, due to the inability of the pultrusion die itself to collect internal temperature and the efficiency of internal and external temperature transfer, the temperature collected by the temperature collection points on the surface of the pultrusion die is greatly affected by environmental factors and has a large deviation from the temperature required by the actual process, which in turn aggravates the temperature control error of the pultrusion die. Summary of the Invention

[0003] In response to the deficiencies in the prior art and the needs of practical applications, in a first aspect, the present invention provides a temperature control method for a pultrusion die, comprising the following steps: determining a material to be solidified and fitting a temperature rise and solidification curve of the material to be solidified; using the temperature rise and solidification curve in combination with the pultrusion speed of the pultrusion die to set a preheating zone, a gel zone and a solidification zone for the pultrusion die along the pultrusion direction; obtaining an internal and external temperature transfer model when an unloaded pultrusion die is heated; using the temperature transfer model and the temperature rise and solidification curve to set the preheating power of the preheating zone; measuring the preheating surface temperature of the preheating zone at the end of preheating, and adjusting the gel power of the gel zone by using the preheating surface temperature in combination with the temperature transfer model and the temperature rise and solidification curve; measuring the gel surface temperature of the gel zone at the end of the gel time, and adjusting the solidification power of the solidification zone by using the gel surface temperature in combination with the temperature transfer model and the temperature rise and solidification curve. The present invention can fit the corresponding temperature rise and curing curves according to different types of materials to be cured, and use the temperature rise and curing curves to divide different heating areas on the pultrusion die. By controlling the temperature of different heating areas, the temperature of each heating section can be precisely controlled during the dynamic curing process of the composite material. The temperature transfer model of the internal and external temperature when the unloaded pultrusion die is heated is obtained and the temperature transfer model of the corresponding heating section is optimized to eliminate the measurement errors caused by the inability of the pultrusion die itself to collect internal temperature and the efficiency of internal and external temperature transfer. At the same time, the optimized temperature transfer model is used to adjust the heating power of the current heating section in real time to prevent the actual temperature from being greater than the set temperature, thereby greatly improving the accuracy of the curing temperature control in the pultrusion die. Furthermore, the present invention detects and compensates the results of the front heating section through the rear heating section, effectively improving the accuracy of temperature control. At the same time, the front process parameters are continuously iteratively updated in the dynamic preparation process to obtain heating parameters that are suitable for the current pultrusion die in the long term.

[0004] Optionally, the method utilizes the temperature rise and curing curve in combination with the pultrusion speed of the pultrusion die to set a preheating zone, a gel zone, and a curing zone along the pultrusion direction of the pultrusion die, including the following steps: dividing the temperature rise curve of the material to be cured into a preheating section, a gel section, and a curing section according to the temperature rise and curing curve; extracting the temperature thresholds and heating times of the preheating section, the gel section, and the curing section respectively; setting a constant heating power for the preheating section, the gel section, and the curing section according to the temperature thresholds; and using the heating time in combination with the pultrusion speed to set the heating lengths of the preheating section, the gel section, and the curing section corresponding to the preheating section, the gel section, and the curing section in the pultrusion die. The present invention avoids unnecessary energy loss in the heating section due to excessive heating time by precisely dividing the heating area. At the same time, the precise division of the heating lengths of different heating area sections also improves the accuracy of temperature control.

[0005] Optionally, the temperature transfer model satisfies the following formula:

[0006] T out-I =σ I T in-I ,

[0007] Where I = 1, 2, 3, I = 1 represents the preheating zone, I = 2 represents the gel zone, I = 3 represents the curing zone, T out-I represents the surface temperature of the pultrusion die in zone I, σ I Indicates the temperature conduction coefficient of the pultrusion die in zone I when no load is applied, T in Indicates the internal temperature of the pultrusion die in the zone.

[0008] Optionally, the use of the temperature transfer model and the temperature rise and curing curve to set the preheating power of the preheating zone includes the following steps: obtaining the preheating temperature peak according to the temperature rise and curing curve, and setting the corresponding preheating power using the preheating temperature peak; optimizing the temperature transfer model according to the material properties and structural properties of the material to be cured to obtain a preheating zone temperature transfer model; measuring the surface temperature of the preheating zone during preheating in real time; and adjusting the preheating power according to the real-time feedback of the preheating zone surface temperature in combination with the preheating zone temperature transfer model.

[0009] Optionally, the preheating zone temperature transfer model satisfies the following formula:

[0010]

[0011] Among them, T eff-1 represents the temperature of the material to be solidified in the pultrusion die in the preheating zone, σ1 represents the temperature conduction coefficient of the pultrusion die in the preheating zone when no load is applied, T out-1 represents the surface temperature of the pultrusion die in the preheating zone, f(ε, V) represents the heat absorption function of the material to be solidified, ε represents the thermal conductivity of the material to be solidified, and V represents the solidification volume of the material to be solidified.

[0012] Optionally, the method of adjusting the gel power of the gel zone by using the preheating surface temperature in combination with the temperature transfer model and the temperature rise and curing curve includes the following steps: determining the preheating result according to the preheating surface temperature; setting a preheating threshold, and compensating the preheating power according to the preheating result until the preheating result meets the preheating threshold; obtaining the gel temperature peak according to the temperature rise and curing curve, and setting the corresponding gel power according to the gel temperature peak; optimizing the temperature transfer model to obtain a gel zone temperature transfer model according to the material properties and structural properties of the material to be cured; measuring the surface temperature of the gel zone during gelation in real time; and adjusting the gel power according to the real-time feedback of the gel surface temperature in combination with the gel zone temperature transfer model. The present invention detects and compensates for the heating results of the front section through the rear section heating zone, effectively improving the accuracy of temperature control. At the same time, the front section process parameters are continuously iteratively updated in the dynamic preparation process to optimize the heating parameters suitable for the current pultrusion die.

[0013] Optionally, the use of the gel surface temperature in combination with the temperature transfer model and the temperature rise curing curve to adjust the curing power of the curing zone includes the following steps: determining the gel result based on the gel surface temperature in combination with the temperature transfer model and the temperature rise curing curve; setting a gel threshold, and compensating the gel power according to the preheating result until the gel result meets the gel threshold; obtaining the curing temperature peak according to the temperature rise curing curve, and setting the corresponding curing power using the curing temperature peak; optimizing the temperature transfer model to obtain a curing zone temperature transfer model based on the material properties and structural properties of the material to be cured; measuring the surface temperature of the curing zone during curing in real time; and adjusting the curing power based on the real-time feedback of the curing surface temperature in combination with the curing zone temperature transfer model.

[0014] In a second aspect, the present invention further provides a temperature control system for a pultrusion die, comprising a data acquisition device, a control device, and a heating device; the data acquisition device is used to acquire the temperature inside and outside the pultrusion die; the control device is used to control the heating power of the heating device using the pultrusion die temperature control method described in the first aspect of the present invention, the heating power including preheating power, gelling power, and curing power; and the heating device is used to heat the pultrusion die according to the heating power obtained by the control device. The pultrusion die temperature control system provided by the present invention has a compact structure, strong information exchange capabilities between modules, high operating efficiency, and rapid adaptation to the actual preparation of different materials to be cured.

[0015] Optionally, the acquisition device includes a plurality of temperature sensors, which are respectively arranged on the surfaces of the preheating zone, the gel zone and the curing zone of the pultrusion die.

[0016] Optionally, the control device includes a parameter input component, an operation component, a heating control component and a display component; the parameter input component is used to input the control parameters of the operation component; the operation component is connected to the acquisition device signal, and the operation component is also connected to the heating control component and the display component signal respectively, and the operation component is used to obtain the heating power of the heating device; the heating control component is connected to the heating device signal, and the heating controller is used to control the heating power of the heating device; the display is used to display the control parameters, the temperature measured by the temperature sensor and the heating temperature of the heating device. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a flow chart of the temperature control method for a pultrusion die according to the present invention;

[0018] Figure 2 Schematic diagram of the temperature-increasing curing curve of epoxy resin and carbon fiber in an embodiment of the present invention;

[0019] Figure 3 Schematic diagram of the classification of heating zones of the pultrusion die of the present invention;

[0020] Figure 4 A flow chart of adjusting the gel power of the gel zone according to the present invention;

[0021] Figure 5 This is a schematic diagram of the temperature control system structure of the pultrusion die of the present invention;

[0022] Figure 6 Schematic diagram of the control device structure in an embodiment of the present invention. DETAILED DESCRIPTION

[0023] Specific embodiments of the present invention will be described in detail below. It should be noted that the embodiments described herein are for illustrative purposes only and are not intended to limit the present invention. In the following description, numerous specific details are set forth to provide a thorough understanding of the present invention. However, it will be apparent to one of ordinary skill in the art that these specific details are not necessarily required to practice the present invention. In other instances, well-known circuits, software, or methods are not specifically described to avoid obscuring the present invention.

[0024] Throughout this specification, references to "one embodiment," "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in connection with the embodiment or example is included in at least one embodiment of the present invention. Therefore, appearances of the phrases "in one embodiment," "in an embodiment," "an example," or "an example" in various places throughout this specification are not necessarily all referring to the same embodiment or example. Furthermore, the particular features, structures, or characteristics may be combined in any suitable combinations and / or subcombinations in one or more embodiments or examples. Furthermore, those of ordinary skill in the art will appreciate that the figures provided herein are for illustrative purposes only and are not necessarily drawn to scale.

[0025] The existing technology for pultrusion die temperature control is not accurate, resulting in excessively long heating time and thus increased heating power. At the same time, due to the inability of the pultrusion die itself to collect internal temperature and the efficiency of internal and external temperature transmission, the temperature collected by the temperature collection points on the surface of the pultrusion die is greatly affected by environmental factors and has a large deviation from the actual temperature required by the process. For the shortcomings of the existing technology and the needs of actual applications, please refer to Figure 1 The present invention provides a temperature control method for a pultrusion die, comprising the following steps:

[0026] S01. Determine a material to be solidified, and fit a temperature-increasing solidification curve of the material to be solidified.

[0027] There are many different types of composite materials produced using the pultrusion process. Resin-based fiber composite materials are composite materials formed through a combination of various manufacturing processes using fibers as reinforcements and resin as a matrix. The fibers in these resin-based fiber composite materials include carbon fibers, aramid fibers, polyethylene fibers, and the like, while the matrix is ​​primarily an organic material such as epoxy resin. In an optional embodiment, a temperature control method for a pultrusion die for a resin-based fiber composite material using carbon fibers as reinforcements is employed. The materials to be cured in step S01 are epoxy resin and carbon fibers. The corresponding temperature-increasing curing curves are obtained by measuring the temperature-increasing curing data of the epoxy resin and carbon fibers in a laboratory. See [ 15 ] for details. Figure 2 , Figure 2 This is the temperature-increasing curing curve of epoxy resin and carbon fiber.

[0028] In another alternative embodiment, in a temperature control method for a pultrusion die for a resin-based fiber composite material using carbon fiber as a reinforcement, the proportions of the remaining materials to be cured, excluding the carbon fiber, are as follows: resin (9611): 5000 g, resin (5562): 5000 g, curing agent A: 120 g, curing agent B: 120 g, release agent: 150 g, and calcium carbonate: 1200 g. A temperature-increasing curing curve, drawn from laboratory-acquired temperature-increasing curing data, yields a preheating temperature of 120° C., a gelling temperature of 135° C., and a curing temperature of 150° C. The pultrusion die has an extrusion speed of 0.3 m / min, and the diameter of the material to be cured is 150 mm and the thickness is 3 mm.

[0029] S02. Using the temperature rise and curing curve in combination with the pultrusion speed of the pultrusion die, the pultrusion die is respectively set with a preheating zone, a gel zone, and a curing zone along the pultrusion direction.

[0030] Composite material pultrusion curing is a continuous process. From the time the uncured material enters the pultrusion die until it exits the pultrusion die after thermal curing, the material is dynamically moved forward by the external traction force. Therefore, the material is dynamically heated in the pultrusion die. In an optional embodiment, see Figure 3 , step S02 uses the temperature rise and curing curve in combination with the pultrusion speed of the pultrusion die to set the preheating zone, gel zone and curing zone of the pultrusion die along the pultrusion direction, including the following steps: dividing the temperature rise curve of the material to be cured into a preheating section, a gel section and a curing section according to the temperature rise and curing curve; extracting the temperature threshold and heating time of the preheating section, gel section and curing section respectively; setting the constant heating power of the preheating section, gel section and curing section according to the temperature threshold; using the heating time in combination with the pultrusion speed to set the heating lengths of the preheating section, gel section and curing section corresponding to the preheating section, gel section and curing section in the pultrusion die. Figure 3 In the figure, the arrow indicates the pulling direction, the rectangular parallelepiped represents the pultrusion die, A represents the preheating zone, B represents the gel zone, C represents the curing zone, the cylindrical end D represents the cured composite material exiting the pultrusion die, and the cylindrical end E represents the uncured material entering the pultrusion die. By precisely dividing the heating zones, the present invention avoids unnecessary energy loss in the heating section due to excessively long heating periods. Furthermore, the precise division of heating lengths in different heating zones also improves the accuracy of temperature control.

[0031] In the present invention, the pultrusion die is respectively set with a preheating zone, a gel zone and a curing zone along the pultrusion direction by combining the temperature rise and curing curve of the material to be cured with the pultrusion speed of the pultrusion die; in actual engineering applications, the temperature rise and curing curve can also be combined with the pultrusion speed of the pultrusion die to set a plurality of temperature control zones along the pultrusion direction, and the number of temperature control zones is greater than 3 (the total length of the temperature control zones is equal to the length of the pultrusion die). As the number of temperature control zones increases, the temperature control of the material to be cured becomes more precise, but the required control structure becomes more complex and the actual architecture cost becomes higher.

[0032] S03. Obtain an internal and external temperature transfer model when the unloaded pultrusion die is heated.

[0033] Because the pultrusion die itself cannot collect internal temperature and internal and external temperature transfer efficiency, the present invention measures or evaluates the heat loss of the pultrusion die itself in advance, and uses the corresponding measurement or evaluation results to compensate for the measurement error of the internal and external temperatures of the pultrusion die, thereby adjusting the heating power of the pultrusion die heating device, thereby achieving accurate setting of the curing temperature of the material to be cured in the pultrusion die. In an optional embodiment, the experimental data measured by the experiment are fitted to the temperature transfer model of the pultrusion die when it is unloaded. Specifically, the temperature transfer model satisfies the following formula:

[0034] T out-I =σ I T in-I ,

[0035] Where I = 1, 2, 3, I = 1 represents the preheating zone, I = 2 represents the gel zone, I = 3 represents the curing zone, T out-I represents the surface temperature of the pultrusion die in zone I, σ I Indicates the temperature conduction coefficient of the pultrusion die in zone I when no load is applied, T in Indicates the internal temperature of the pultrusion die in the zone.

[0036] S04. Using the temperature transfer model and the temperature rise curing curve, set the preheating power of the preheating zone.

[0037] In an optional embodiment, the use of the temperature transfer model and the temperature rise and curing curve to set the preheating power of the preheating zone as described in step S04 includes the following steps: obtaining the preheating temperature peak according to the temperature rise and curing curve, and setting the corresponding preheating power using the preheating temperature peak; optimizing the temperature transfer model to obtain a preheating zone temperature transfer model based on the material properties and structural properties of the material to be cured; measuring the surface temperature of the preheating zone in real time during preheating; and adjusting the preheating power based on the real-time feedback of the preheating zone surface temperature in combination with the preheating zone temperature transfer model. In this embodiment, the preheating zone temperature transfer model satisfies the following formula:

[0038]

[0039] Among them, T eff-1 represents the temperature of the material to be solidified in the pultrusion die in the preheating zone, σ1 represents the temperature conduction coefficient of the pultrusion die in the preheating zone when no load is applied, T out-1 Represents the surface temperature of the pultrusion die in the preheating zone, f(ε, V) represents the heat absorption function of the material to be solidified, ε represents the thermal conductivity of the material to be solidified, and V represents the solidified volume of the material to be solidified. The surface temperature of each heating area of ​​the pultrusion die is easy to measure. Therefore, the present invention reduces the temperature measurement error inside and outside by optimizing the temperature transfer model of the preheating zone, that is, the surface temperature of the surface preheating zone can correspond to the temperature inside the pultrusion die. Specifically, the preheating temperature peak is specifically delineated by relevant staff based on the temperature rise and solidification curve of the material to be solidified. After determining the preheating temperature peak, full-power heating is used to achieve the heating of the material to be solidified until the material to be solidified is heated to 80% of the preheating temperature peak. Then, the surface temperature of the preheating zone is measured in real time during preheating. The preheating power is adjusted according to the real-time feedback of the surface temperature of the preheating zone combined with the temperature transfer model of the preheating zone, so that the material to be solidified is heated to the preheating temperature peak.

[0040] S05, measuring the preheating surface temperature of the preheating zone at the end of preheating, and adjusting the gel power of the gel zone by using the preheating surface temperature in combination with the temperature transfer model and the temperature rise curing curve.

[0041] See Figure 4In an optional embodiment, adjusting the gel power of the gel zone using the preheating surface temperature in combination with the temperature transfer model and the temperature rise and curing curve includes the following steps: determining a preheating result based on the preheating surface temperature; setting a preheating threshold and compensating the preheating power based on the preheating result until the preheating result meets the preheating threshold; obtaining a gel temperature peak based on the temperature rise and curing curve and setting the corresponding gel power based on the gel temperature peak; optimizing the temperature transfer model to obtain a gel zone temperature transfer model based on the material and structural properties of the material to be cured; measuring the surface temperature of the gel zone during gelation in real time; and adjusting the gel power based on the real-time feedback of the gel surface temperature in combination with the gel zone temperature transfer model. In this embodiment, the preheating threshold is ±5°C of the preheating temperature peak. If the preheating result is greater than the preheating threshold, preheating compensation is not performed in the gel zone. If the preheating result is less than the preheating threshold, preheating compensation is performed in the gel zone. Specific compensation methods include increasing the heating power of the gel zone or extending the length of the preheating zone. However, in actual engineering, adjusting the heating power of the gel zone is simpler and more automated than extending the length of the preheating zone. The present invention detects and compensates the results of the front-stage heating zone through the rear-stage heating zone, effectively improving the accuracy of temperature control. At the same time, the front-stage process parameters are continuously iteratively updated in the dynamic preparation process to obtain heating parameters suitable for the current pultrusion die.

[0042] In this embodiment, the gel zone temperature transfer model satisfies the following formula:

[0043]

[0044] Among them, T eff-2 represents the temperature of the material to be solidified in the gel zone pultrusion die, σ2 represents the temperature conduction coefficient of the pultrusion die in the gel zone when no load is applied, T out-2 represents the surface temperature of the pultrusion die in the gel zone, f(ε, V) represents the heat absorption function of the material to be solidified, ε represents the thermal conductivity of the material to be solidified, and V represents the solidification volume of the material to be solidified.

[0045] S06. Measuring the gel surface temperature of the gel zone at the end of the gel time, and adjusting the curing power of the curing zone by using the gel surface temperature in combination with the temperature transfer model and the temperature-increasing curing curve.

[0046] In an optional embodiment, the method of adjusting the curing power of the curing zone by using the gel surface temperature in combination with the temperature transfer model and the temperature rise curing curve includes the following steps: determining the gel result based on the gel surface temperature in combination with the temperature transfer model and the temperature rise curing curve; setting a gel threshold, compensating the gel power based on the preheating result until the gel result meets the gel threshold; obtaining the curing temperature peak based on the temperature rise curing curve, and setting the corresponding curing power based on the curing temperature peak; optimizing the temperature transfer model to obtain a curing zone temperature transfer model based on the material properties and structural properties of the material to be cured; measuring the surface temperature of the curing zone during curing in real time; and adjusting the curing power based on the real-time feedback of the curing surface temperature in combination with the curing zone temperature transfer model. In this real-time example, the setting of the gel threshold, the method of determining the gel threshold and the gel result, and the method of compensating the gel power can refer to the embodiment of step S05. The curing zone temperature transfer model obtained in this embodiment satisfies the following formula:

[0047]

[0048] Among them, T eff-3 represents the temperature of the material to be solidified in the pultrusion die in the solidification zone, σ3 represents the temperature conduction coefficient of the pultrusion die in the solidification zone when no load is applied, T out-3 represents the surface temperature of the pultrusion die in the curing zone, f(ε, V) represents the heat absorption function of the material to be cured, ε represents the thermal conductivity of the material to be cured, and V represents the curing volume of the material to be cured.

[0049] The present invention can fit the corresponding temperature rise and curing curves according to different types of materials to be cured, and use the temperature rise and curing curves to divide different heating areas on the pultrusion die. By controlling the temperature of different heating areas, the precise control of the temperature of each heating section during the dynamic curing process of the composite material is realized; and by obtaining the internal and external temperature transfer model when the unloaded pultrusion die is heated and optimizing the temperature transfer model of the corresponding heating section, the measurement error caused by the inability of the pultrusion die itself to collect the internal temperature and the internal and external temperature transfer efficiency is eliminated; at the same time, the optimized temperature transfer model is used to adjust the heating power of the current heating section in real time to prevent the actual temperature from being greater than the set temperature, thereby greatly improving the accuracy of the curing temperature control in the pultrusion die. Furthermore, the present invention detects and compensates the results of the front heating zone through the rear heating zone, effectively improving the accuracy of temperature control. At the same time, the front process parameters are continuously iteratively updated in the dynamic preparation process to obtain heating parameters that are suitable for the current pultrusion die in the long term.

[0050] See Figure 5The present invention also provides a temperature control system for a pultrusion die, the temperature control system for the pultrusion die includes a collection device, a control device and a heating device; the collection device is used to collect the temperature inside and outside the pultrusion die; the control device is used to control the heating power of the heating device through the temperature control method for the pultrusion die provided by the present invention, the heating power includes preheating power, gel power and curing power; the heating device is used to heat the pultrusion die according to the heating power obtained by the control device. The temperature control system for the pultrusion die provided by the present invention has a compact structure, strong information exchange capabilities between modules, high operating efficiency, and fast self-adaptation speed for the actual preparation of different materials to be cured. Among them, the control device can choose to use the PLC language to write the corresponding PID control circuit program, and then connect the corresponding collection device and heating device through the corresponding PID circuit to control the heating power of the heating device.

[0051] In an optional embodiment, the acquisition device includes multiple temperature sensors, which are respectively arranged on the surface of the preheating zone, gel zone and curing zone of the pultrusion die. For the preheating zone, gel zone and curing zone of the pultrusion die, the control device can be a control device corresponding to each zone separately, or a control device for overall control. In another optional embodiment, please refer to Figure 6 The control device includes a parameter input component, a calculation component, a heating control component, and a display component; the parameter input component is used to input control parameters of the calculation component; the calculation component is signal-connected to the acquisition device, and the calculation component is also signal-connected to the heating control component and the display component, respectively, and the calculation component is used to obtain the heating power of the heating device; the heating control component is signal-connected to the heating device, and the heating controller is used to control the heating power of the heating device; the display is used to display the control parameters, the temperature measured by the temperature sensor, and the heating temperature of the heating device. In this embodiment, the control device is applicable to any heating zone among the preheating zone, gel zone, and curing zone. Its parameter input component can only input corresponding control parameters, and the display component only displays relevant parameters of the corresponding heating zone. Furthermore, in this embodiment, the parameter input component and the display component select a touch-sensitive display screen to simultaneously meet the corresponding functions, reduce the system size, and facilitate engineering use.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and description of the present invention.

Claims

1. A temperature control method for a pultrusion die, characterized in that: The steps include: Determining a material to be cured, and fitting a temperature-increasing curing curve of the material to be cured; The method utilizes the temperature rise and curing curve in combination with the pultrusion speed of the pultrusion die to set a preheating zone, a gelling zone, and a curing zone along the pultrusion direction of the pultrusion die, including the following steps: Dividing the temperature rise curve of the material to be cured into a preheating section, a gel section and a curing section according to the temperature rise curing curve; Extract the temperature thresholds and heating time of the preheating stage, gel stage and curing stage respectively; Set constant heating power for the preheating section, gel section, and curing section according to temperature thresholds; By combining the heating time with the pultrusion speed, the heating lengths of the preheating zone, gelling zone and curing zone corresponding to the preheating zone, gelling zone and curing zone in the pultrusion die are set; Obtain the internal and external temperature transfer model when heating an unloaded pultrusion die; The temperature transfer model satisfies the following formula: ， in, , Indicates the preheating zone, represents the gel area, Indicates the solidification area, express The surface temperature of the pultrusion die in the zone, Indicates no-load The temperature conductivity coefficient of the pultrusion die in the area, Indicates the internal temperature of the pultrusion die in the zone; The preheating power of the preheating zone is set by using the temperature transfer model and the temperature rise curing curve, including the following steps: Obtaining a preheating temperature peak value according to the temperature rise and curing curve, and setting a corresponding preheating power using the preheating temperature peak value; Optimizing the temperature transfer model to obtain a preheating zone temperature transfer model based on the material properties and structural properties of the material to be solidified; Real-time measurement of the surface temperature of the preheating zone during preheating; Adjust the preheating power based on the real-time feedback of the preheating zone surface temperature and the preheating zone temperature transfer model; measuring the preheating surface temperature of the preheating zone at the end of preheating, and adjusting the gel power of the gel zone by using the preheating surface temperature in combination with the temperature transfer model and the temperature rise curing curve; The gel surface temperature of the gel zone at the end of the gel time is measured, and the curing power of the curing zone is adjusted by using the gel surface temperature in combination with the temperature transfer model and the temperature rise curing curve.

2. The temperature control method of the pultrusion die according to claim 1, characterized in that: The temperature transfer model of the preheating zone satisfies the following formula: ， in, Indicates the temperature of the material to be solidified in the pultrusion die in the preheating zone. Indicates the temperature conduction coefficient of the pultrusion die in the preheating zone when no load is applied. Indicates the surface temperature of the pultrusion die in the preheating zone, represents the heat absorption function of the material to be solidified, represents the thermal conductivity of the material to be solidified, Indicates the cured volume of the material to be cured.

3. The temperature control method of the pultrusion die according to claim 1, characterized in that: The method comprises the following steps: adjusting the gel power of the gel zone by utilizing the preheated surface temperature in combination with the temperature transfer model and the temperature rise curing curve; determining a preheating result according to the preheating surface temperature; Setting a preheating threshold, and compensating the preheating power according to the preheating result until the preheating result meets the preheating threshold; Obtaining a gel temperature peak value according to the temperature rise curing curve, and setting a corresponding gel power using the gel temperature peak value; Optimizing the temperature transfer model to obtain a gel zone temperature transfer model based on the material properties and structural properties of the material to be solidified; Real-time measurement of the surface temperature of the gelling area during gelling; The gel power is adjusted according to the real-time feedback of the gel surface temperature and the gel zone temperature transfer model.

4. The temperature control method of the pultrusion die according to claim 1, characterized in that: The curing power of the curing zone is adjusted by utilizing the gel surface temperature in combination with the temperature transfer model and the temperature rise curing curve, comprising the following steps: Determine the gelation result according to the gel surface temperature, in combination with the temperature transfer model and the temperature rise curing curve; Setting a gel threshold, and compensating the gel power according to the preheating result until the gel result meets the gel threshold; Obtaining a curing temperature peak value according to the temperature-raising curing curve, and setting a corresponding curing power using the curing temperature peak value; Optimizing the temperature transfer model to obtain a curing zone temperature transfer model based on the material properties and structural properties of the material to be cured; Real-time measurement of the surface temperature of the curing area during curing; The curing power is adjusted according to the real-time feedback of the curing surface temperature and the temperature transfer model of the curing zone.

5. A temperature control system for a pultrusion die, characterized in that: The temperature control system of the pultrusion die includes a collection device, a control device and a heating device; The collecting device is used to collect the temperature inside and outside the pultrusion die; The control device is used to control the heating power of the heating device by the temperature control method of the pultrusion die according to any one of claims 1 to 4, wherein the heating power includes preheating power, gel power and curing power; A heating device is used to heat the pultrusion die according to the heating power obtained by the control device.

6. The temperature control system of the pultrusion die according to claim 5, characterized in that: The acquisition device includes a plurality of temperature sensors, which are respectively arranged on the surfaces of the preheating zone, the gel zone and the curing zone of the pultrusion die.

7. The temperature control system of the pultrusion die according to claim 6, characterized in that: The control device includes a parameter input component, a calculation component, a heating control component and a display component; The parameter input component is used to input the control parameters of the operation component; The computing component is connected to the acquisition device by signal, and is also connected to the heating control component and the display component by signal, and is used to obtain the heating power of the heating device; The heating control component is connected to the heating device by signal, and the heating control component is used to control the heating power of the heating device; The display component is used to display the control parameter, the temperature measured by the temperature sensor and the heating temperature of the heating device.

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