Segmented heated nip roller apparatus for a composite fiber placement machine and control method

Abstract

The application discloses a segmented heating and pressing roller device for a composite material fiber placement machine and a control method, relates to the field of automatic composite material forming, and is especially suitable for thermoplastic and thermosetting composite material fiber placement machines (AFP) and tape laying machines (ATL). The device divides an integrated pressing roller into multiple independent segmented pressing rollers in the axial direction, each segment is internally provided with a torque motor, a radial adjusting device and a heating module, the surface is provided with a coating and micro textures, and temperature and pressure sensors are arranged. The control system and method dynamically control the temperature, pressure and motion posture of each segment based on sensor data through a closed-loop algorithm. The application can meet the differentiated requirements of different regions of a complex-shaped component for temperature and pressure, adapt to various fiber placement paths, layer thicknesses and material properties of the component, preset and dynamically adjust target parameters, realize precise cooperative control and feedback regulation of temperature, pressure and motion posture, and improve forming quality and efficiency.

Description

Technical Field

[0001] This invention relates to the field of automated molding equipment for composite materials, and is particularly applicable to thermoplastic and thermosetting composite fiber layers (AFP) and tape layers (ATL). The segmented heating roller device enables high-precision coordinated control of temperature and pressure during the laying process. Background Technology

[0002] In the field of automated molding equipment technology for composite materials, thermoplastic and thermosetting composite fiber placers (AFP) and tape layers (ATL) are key equipment for realizing automated and high-quality molding of composite components, and their performance directly affects the molding quality and production efficiency of composite components.

[0003] In the process of composite fiber layup, the heated roller device plays a crucial role: by heating and softening the pre-impregnated fiber bundle and pressing it, a good bond is achieved between the fiber bundle and the substrate or the laid-up layer.

[0004] Traditional heating roller devices typically employ an integrated heating and single pressure control mode, which is insufficient to meet the differentiated temperature and pressure requirements of different areas during the fiber layup process of complex-shaped components. In actual production, the geometry of composite material components is often complex and varied, with differences in fiber layup paths, layer thicknesses, and material properties in different parts. This necessitates that the heating rollers provide precisely matched temperatures and pressures at different locations.

[0005] Furthermore, with the increasing demands for lightweight and high-performance composite material components in fields such as aerospace, the molding process standards for thermoplastic and thermosetting composite materials are also rising. Thermoplastic composites require precise temperature control to achieve melting and rapid solidification, while thermosetting composites have stringent requirements for the temperature and pressure profiles during the curing process. Traditional heated roller devices have limitations in the coordinated control of temperature and pressure, which has become a significant factor restricting the development and application of composite material molding processes.

[0006] Therefore, developing a segmented heated pressure roller device suitable for thermoplastic and thermosetting composite fiber layers (AFP) and tape layers (ATL), and achieving coordinated control of temperature and pressure, is of great practical significance and urgent market demand for improving the molding quality and production efficiency of composite components and expanding the application range of composite materials.

[0007] Existing document CN204584954U discloses a segmented pressure roller mechanism for a sander. This mechanism includes a strip-shaped base plate on which multiple pressure roller devices are horizontally mounted. Each pressure roller device includes a lifting mounting base, a pressure roller, a spring, and a connecting guide rod. The connecting guide rod is vertically positioned, with its upper end fixed to the base plate and its lower end slidably mounted in a sliding hole in the lifting mounting base. The spring is sleeved on the connecting guide rod, with its two ends connected to the base plate and the lifting mounting base, respectively. The pressure roller is cylindrical and horizontally mounted in a mounting groove in the lifting mounting base, the opening width of which is smaller than the diameter of the pressure roller. The segmented pressure roller mechanism of the sander allows multiple pressure roller devices to press down on different parts of the sheet metal. The springs adapt to the different thicknesses of various parts of the sheet metal, ensuring moderate pressure on each part, avoiding unbalanced or skewed feeding, guaranteeing processing quality, preventing damage to the sheet metal due to excessive pressure, and preventing the sheet metal from rebounding and injuring the operator. Although the aforementioned literature achieved passive adaptive adjustment of pressure during sheet metal processing through segmented pressure roller design and spring structure, the adjustment method is passive, lacks precision, and lacks temperature control function.

[0008] Existing document CN110901203A discloses a segmented controllable electric heating roller mechanism. This roller mechanism includes a heating roller body, a heating mechanism disposed within the heating roller body, and a heating mechanism mounting mechanism. The heating mechanism includes multiple segmented heating components, each mounted within the heating roller body via the mounting mechanism. The heating components are separated by partitions, and the heating tubes on the heating plates of each component are individually controlled. Each heating component is also equipped with a temperature sensor. In this document, by segmenting the heating components within the heating roller body and individually controlling each segment, individual temperature control can be achieved based on the actual temperature, ensuring a relatively consistent temperature across all segments of the heating roller and improving the quality of the hot pressing. While this document achieves differentiated temperature adjustment and uniformity control across different segments of the heating roller through segmented heating component design and independent temperature control logic, it only achieves temperature control by fixing the heating components and does not involve a pressure adjustment module, thus failing to adapt to the complex curved contours of composite material components. Summary of the Invention

[0009] The purpose of this invention is to overcome the above-mentioned problems and provide a segmented heating pressure roller and control method for a composite material fiber placement machine.

[0010] In a first aspect, the present invention provides a segmented heated pressure roller device for a composite material fiber placement machine, the device comprising the following components:

[0011] The segmented pressure roller is cylindrical and driven to rotate by an independent torque motor. Several segmented pressure rollers are combined together along the axial direction to form the pressure roller device.

[0012] A radial adjustment device is installed inside each segmented pressure roller to adjust the distance between the roller pressing surface of each segmented pressure roller and the base plate.

[0013] The heating module is installed inside each segmented pressure roller and is used to heat the roller pressing surface.

[0014] It also includes a control module, which establishes a communication connection with the heating module, radial adjustment device and torque motor, and regulates their operating status.

[0015] Preferably, the roller surface of each segmented roller that contacts the material is covered with a coating, and the material of the coating can be at least one of polyimide (PI) based composite material, ceramic particle reinforced silicone rubber, and bismaleimide based composite material.

[0016] The coated roll-pressed surface has a micro-texture structure, and the surface roughness of this micro-texture structure is a preset threshold that can be adjusted based on the processing parameters.

[0017] The end face of the torque motor is rigidly bonded to the material-coated roll-pressed surface using an end-face sealing plate.

[0018] The radial adjustment device is seamlessly bonded to the roll-pressed surface that has been coated with material.

[0019] Preferably, each segmented pressure roller has a hollow shaft at its center, which is used to accommodate the circuit wiring of the torque motor, radial adjustment device and other components.

[0020] Preferably, a preset gap is provided between each segmented pressure roller, and the preset gap value is between 0.5mm and 1mm, including 0.5mm and 1mm, to avoid mutual interference between the segmented pressure rollers during operation.

[0021] Preferably, the heat insulation plate inside the roller and the roller together form a sealed chamber, and the heating module is located in the sealed chamber.

[0022] Preferably, a temperature sensor is installed in the sealed chamber of each segmented pressure roller or on the roller pressing surface to detect the real-time operating temperature of each segmented pressure roller.

[0023] Preferably, a pressure sensor is installed at the contact point between the roller pressing surface of each segmented roller and the base plate to detect the real-time working pressure of the roller pressing surface in contact with the material during the material laying process.

[0024] In a second aspect, the present invention provides a control method for a segmented heated pressure roller device for a composite material fiber placement machine as described above. The segmented heated pressure roller device for the composite material fiber placement machine includes a temperature sensor and a pressure sensor. The temperature sensor is located in a sealed chamber formed by the roller pressing surface and a heat insulation plate inside the roller, or located on the roller pressing surface. The pressure sensor is located at the contact point between the roller pressing surface and the base plate. The control method includes the following steps:

[0025] S1. Preset pressure and temperature reference values ​​in the above control module;

[0026] S2. Real-time pressure and real-time temperature values ​​are obtained through the above-mentioned temperature sensor and pressure sensor and transmitted to the above-mentioned control module.

[0027] S3. Calculate the pressure deviation and temperature deviation in the above control module;

[0028] S4. Based on the pressure deviation and temperature deviation mentioned above, a control signal is generated using a multivariable PID control algorithm;

[0029] S5. The radial adjustment device and heating module are driven by the above control signals to form a closed-loop control system.

[0030] In a third aspect, the present invention provides a composite material fiber placement machine that includes the aforementioned segmented heated pressure roller structure for a composite material fiber placement machine.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0032] 1. This invention provides a segmented heated pressure roller device for a composite material fiber placement machine, which breaks down an integrated pressure roller into independently adjustable segmented structures. The device integrates a heating module, a torque motor, a radial adjustment device, and a control module, enabling precise and coordinated control of the temperature, pressure, and motion posture of each segmented pressure roller during the fiber placement process of complex curved surface composite material components. This meets the differentiated temperature and pressure requirements of different areas of complex-shaped components and adapts to various fiber placement paths, layup thicknesses, and material properties.

[0033] 2. This invention provides a control method for a composite material fiber placement machine. Based on the type of prepreg and process requirements, target parameters are preset, and deviation calculation and closed-loop adjustment are performed in combination with real-time collected pressure and temperature data. This enables precise independent or coordinated control of the contact pressure and temperature of each segmented pressure roller.

[0034] 3. This invention provides a composite material fiber placement machine, which, by integrating an independently adjustable segmented pressure roller structure, can achieve high-precision, high-efficiency, and high-stability molding in the fiber placement process of complex composite material components. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the overall pressure roller structure in Example 1.

[0036] Figure 2 This is a schematic diagram of a single-segment segmented pressure roller in Example 1.

[0037] Figure 3 This is a schematic diagram of a single-segment segmented pressure roller in Example 1.

[0038] Figure 4 This is a schematic diagram of the linear guide rail in Example 1.

[0039] Figure 5 This is a flowchart of the control system in Example 1.

[0040] Marked in the image:

[0041] 1-High temperature resistant layer of pressure roller, 2-Linear guide rail, 3-Torque motor, 4-Hollow shaft, 5-Heating resistance wire, 6-Circular ring plate, 7-End face sealing plate, 8-Bolt, 9-Guide rail motor, 10-Moving slider, 11-Lead screw, 12-Radial moving plate, 13-Screw. Detailed Implementation

[0042] The present invention will now be described in further detail with reference to specific embodiments. However, this should not be construed as limiting the scope of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0043] Unless otherwise specified, the terms "upper," "lower," "left," "right," "center," "inner," and "outer," etc., used in the description of specific embodiments of the present invention to indicate orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationship in which the product / equipment / device is usually placed during use. These terms are merely for the purpose of facilitating the description of the present invention or simplifying the description in specific embodiments, and for enabling those skilled in the art to quickly understand the solution, and do not indicate or imply that a particular device / component / element must have a specific orientation, or be constructed and operated in a specific positional relationship. Therefore, they should not be construed as limitations on the present invention.

[0044] Furthermore, the use of terms such as "horizontal," "vertical," "suspended," "parallel," and "coaxial" does not imply that the corresponding device / component / element must be absolutely horizontal, vertical, suspended, parallel, or coaxial. Slight tilt or deviation is permissible, as long as it does not affect the normal function of the relevant component. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," not that the structure must be perfectly horizontal; a slight tilt is acceptable. "Coaxial" means that two components are arranged as coaxially as possible, allowing them to move coaxially or approximately coaxially when their relative positions change. Alternatively, it can be simplified to mean that the corresponding device / component / element, when arranged in "horizontal," "vertical," "suspended," "parallel," or "coaxial" directions, can have an error / deviation of ±10% relative to the corresponding direction, more preferably within ±8%, more preferably within ±6%, more preferably within ±5%, and more preferably within ±4%. For example, the deviation in the "coaxial" direction is controlled within 0.2-1mm, preferably within 0.2-0.5mm. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its function in the solution of the present invention.

[0045] Furthermore, the use of terms such as "first," "second," and "third" in terminology is merely for distinguishing descriptions of identical or similar components and should not be interpreted as emphasizing or implying the relative importance of a particular component.

[0046] Furthermore, in the description of the embodiments of the present invention, "several", "more than", and "a number of" represent at least two. The number can be any number, such as two, three, four, five, six, seven, eight, or nine, and can even exceed nine.

[0047] Furthermore, in the description of the technical solution of this invention, unless otherwise explicitly specified / limited / restricted, the terms "set up," "install," "connect," "link," "provided with," "laid out," and "arranged" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to connection methods commonly used in the art, such as welding, riveting, bolting, and threaded connections. Such connections can be mechanical, electrical, or communication connections; they can be direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components.

[0048] Example 1

[0049] A segmented heating roller device for a composite material fiber placement machine includes several segmented rollers, a radial adjustment device, a heating module, and a control module. The entire device achieves precise control of temperature and pressure during the composite material fiber placement process through the coordinated operation of its components.

[0050] (1) Segmented pressure roller structure:

[0051] The structure of the pressure roller device is as follows Figure 1 As shown, several segmented pressure rollers are axially combined to form the entire pressure roller device. These segmented pressure rollers are axially assembled by connecting hollow shafts 4 in series. The hollow shafts 4 of each segmented pressure roller adopt a coaxial through-structure. The ends of the hollow shafts 4 of adjacent segments are fixed with locking nuts via a stepped fit. Precision control of the fit ensures that the coaxiality of each segment meets the usage requirements. The locking nuts employ an anti-loosening design to prevent loosening due to vibration during yarn laying. Shims with preset gaps are fitted between adjacent segments. The inner ring of the shim is interference-fitted with the hollow shaft 4, and the outer ring does not extend beyond the surface 1 of the high-temperature resistant layer of the pressure roller, ensuring gap stability and preventing rotational interference between segments. The two ends of the overall pressure roller device are limited by end plates. The end plates are fixed to the end face sealing plate 7 of the outermost segment by end plate fixing bolts, forming a complete rigid support structure to ensure the stability of the entire device during operation.

[0052] Segmented pressure roller structure, such as Figure 2 and Figure 3 As shown, each segmented pressure roller is cylindrical and driven by an independent torque motor 3, ensuring that the movement posture of each segment can be independently adjusted. To avoid interference between the segmented pressure rollers during operation, a preset gap is provided between every two adjacent segmented pressure rollers, with the gap value set between 0.5mm and 1mm (inclusive). The axial length of each segmented pressure roller can be designed to be 30-80mm (inclusive) according to the actual yarn laying requirements, adapting to the processing needs of components of different sizes.

[0053] Each segmented pressure roller has a hollow shaft 4 at its center. The interior of the hollow shaft is used to accommodate the circuit wiring of the torque motor 3, radial adjustment device and other components, so as to realize the orderly storage and protection of the cables and avoid the cables from getting tangled or worn during the movement.

[0054] The segmented pressure rollers have a coating (i.e., the high-temperature resistant layer 1) on their surfaces that come into contact with the material. The coating material is made of ceramic particle-reinforced silicone rubber (such as with added Al2O3 or SiC particles) or polyimide-based composite material, which combines high-temperature resistance and elasticity to meet the tight fit requirements during composite material laying. The coated roller surface is processed with a micro-texture structure with a preset threshold, and the texture depth is 1-2 mm. By increasing the surface roughness, the friction between the roller and the pre-impregnated yarn is improved, preventing slippage or displacement during yarn laying.

[0055] The end face of the torque motor 3 is rigidly connected to the coated roller surface by using an end face sealing plate 7. The torque motor 3 and the radial adjustment device are fixed on the end face sealing plate 7 by bolts 8 to ensure stable power transmission and good structural rigidity, thereby realizing the rotation of the pressure roller.

[0056] The specific working relationships of each core component are as follows:

[0057] Function and installation of hollow shaft 4: Hollow shaft 4 runs through the axis of segmented pressure roller, and its outer wall is connected to torque motor 3 by a key to ensure that hollow shaft 4 can rotate synchronously with pressure roller; both ends of hollow shaft 4 extend out of the outer side of end face closed plate 7 to achieve step engagement with adjacent segmented hollow shaft 4.

[0058] Position and fixing of torque motor 3: Torque motor 3 is arranged in the internal cavity of the pressure roller. The motor housing and the outer wall of the hollow shaft 4 are fitted with clearance. The motor end face and the inner side of the end face sealing plate 7 are fixed by bolts 8. The motor output shaft and the inner wall of the hollow shaft 4 are connected by a flexible coupling to ensure that there is no radial runout during power transmission.

[0059] The mating relationship of the end face sealing plate 7: The end face sealing plate 7 is circular, and its side facing the high temperature resistant layer 1 of the pressure roller is rigidly attached to the end face of the high temperature resistant layer 1 of the pressure roller, and the flatness of the attachment surface meets the assembly requirements; the side facing the torque motor 3 is machined with a motor mounting countersunk hole and a linear guide 2 fixing surface, so as to realize the integrated installation of the torque motor 3 and the linear guide 2.

[0060] The linear guide 2 and the segmented pressure rollers are connected as follows: The fixed seat of the linear guide 2 is connected to the inner fixed surface of the end face sealing plate 7 by bolts 8. The movable end of the linear guide 2 is fixed to the radial moving plate 12 by screws 13. The radial moving plate 12 adopts an arc-shaped structure, and its curvature is consistent with the inner side of the high temperature resistant layer 1 of the pressure roller. The outer side of the radial moving plate 12 is connected to the inner side of the high temperature resistant layer 1 of the pressure roller by welding. The welding points are evenly distributed to ensure that the linear guide 2 can synchronously drive the high temperature resistant layer 1 of the pressure roller to make radial movements when driven.

[0061] (2) Radial adjustment device:

[0062] A radial adjustment device is installed inside each segmented pressure roller to adjust the distance between the roller's pressing surface and the base plate, thereby precisely controlling the pressing pressure. In this embodiment, the radial adjustment device uses a linear guide rail 2, which is fitted seamlessly with the end-face sealing plate 7 and fixed by bolts 8 to connect the linear guide rail to the pressure roller; the structure of the linear guide rail 2 is as follows. Figure 4As shown, the radial moving plate 12 is connected to the moving slider 10 by screws 13. During the movement of the guide rail slider, the radial moving plate is used to realize the radial movement of the pressure roller. Driven by the guide rail motor 9, the moving slider 10 can move on the lead screw 11, thereby driving the pressure roller to move radially, realizing the dynamic adjustment of the distance between the roller pressing surface and the base plate, and meeting the pressure requirements of different layup thicknesses and curved surface profiles.

[0063] The details of the fit between the radial moving plate 12 and each segment of the pressure rollers, as well as the specific implementation logic of radial adjustment, are as follows:

[0064] The radial moving plate 12 adopts an arc-shaped steel plate structure, the curvature of which matches the inner curvature of the high-temperature resistant layer 1 of the pressure roller, and the fitting gap meets the assembly accuracy requirements; one end of the radial moving plate 12 is machined with a connecting hole that matches the moving slider 10, and is rigidly fixed by screws 13; the other end is machined with uniformly distributed welding holes, which are welded to the pre-embedded steel sheet on the inner side of the high-temperature resistant layer 1 of the pressure roller to ensure uniform force transmission and no deformation.

[0065] The radial movement process is as follows: After the guide rail motor 9 is powered on, it drives the lead screw 11 to rotate. The lead screw 11 and the moving slider 10 are connected by a thread to convert the rotational motion into linear motion. The moving slider 10 slides along the guide rail groove of the linear guide rail 2, and simultaneously drives the radial moving plate 12 to make a linear motion perpendicular to the axis of the pressure roller. Since the radial moving plate 12 is rigidly connected to the high temperature resistant layer 1 of the pressure roller, it pushes the high temperature resistant layer 1 of the pressure roller to move closer to or away from the base plate in the radial direction, so as to achieve precise adjustment of the distance between the roller pressing surface and the base plate, and finally achieve the purpose of controlling the roller pressing pressure.

[0066] (3) Heating module:

[0067] Heating modules are installed inside each segmented pressure roller to heat the roller surface. In this embodiment, heating resistance wire 5 is selected as the heating module. The heating resistance wire is wound around the inner side of the roller surface, and a circular plate 6 is used as a heat insulation plate. The heat insulation plate and the roller surface together form a sealed chamber, and the heating resistance wire is located inside the sealed chamber, which can reduce heat loss due to outward diffusion. A temperature sensor is installed in each sealed chamber to monitor the temperature data of the heating area in real time, providing a basis for temperature control.

[0068] (4) Sensors and control modules:

[0069] Pressure sensors are installed at the contact points between each roller surface after coating treatment and the base plate to detect the contact pressure between the roller surface and the material in real time during the filament laying process; both temperature and pressure sensors are connected to the control module to transmit detection data in real time.

[0070] The control module uses a PLC module, which establishes communication connections with the heating resistance wires 5, linear guides 2, and torque motors 3 within each segmented pressure roller, enabling centralized control of the operating status of each component. The control system flowchart is as follows: Figure 5 As shown, the details are as follows:

[0071] The control module has preset pressure and temperature reference values, which are set according to the type of prepreg and the requirements of the fiber laying process.

[0072] Temperature and pressure sensors collect temperature and pressure data of each segmented pressure roller in real time and transmit them to the control module.

[0073] The control module calculates the temperature deviation between the real-time temperature value and the preset temperature reference value, and the pressure deviation between the real-time pressure value and the preset pressure reference value;

[0074] Based on the above deviation, a control signal is generated using a multivariable PID control algorithm.

[0075] The control signal drives the heating resistance wire to adjust the output power (to achieve closed-loop temperature control), and at the same time drives the linear guide rail to perform radial displacement adjustment (to achieve closed-loop pressure control), so that the temperature and pressure of each segmented pressure roller are stabilized within the preset reference value range.

[0076] This embodiment achieves independent control of the temperature, pressure, and motion posture of each segmented pressure roller through segmented structural design and closed-loop control logic. It can accurately adapt to the differentiated needs of different areas of complex shaped components, effectively improving the quality and efficiency of composite material fiber laying molding.

[0077] Example 2

[0078] The segmented heating roller device in this embodiment is composed of 6 segmented rollers arranged axially (to meet the requirements of 1.5m wide yarn laying). Each component works together to achieve independent control of temperature, pressure and motion posture.

[0079] (1) Segmented pressure roller structure:

[0080] Basic parameters: Each segmented pressure roller is cylindrical, with an axial length of 50mm designed according to the complexity of the yarn laying path. Short sections of 30mm can be selected for areas with large curvature changes, while long sections of 80mm are selected for straight areas. A gap of 0.8mm is reserved between adjacent segmented pressure rollers, which are isolated by polytetrafluoroethylene gaskets to avoid interference caused by vibration during operation.

[0081] Drive and transmission: Each pressure roller is independently driven by a 200W torque motor, model 130ST-M15015. The motor output shaft is rigidly connected to the hollow shaft of the pressure roller through a flexible coupling to ensure that the speed synchronization accuracy is ≤±2rpm, which is suitable for the filament laying speed requirements of 0.5-5m / min.

[0082] Roll forming surface treatment:

[0083] The coating material is made of ceramic particle reinforced silicone rubber with 30% Al2O3 particles added. It is 1.5mm thick and has both high temperature resistance of 80-250℃ and elasticity of Shore hardness of 60±5A, which can closely fit complex curved surfaces.

[0084] The surface is laser-engraved with micro-textures, which are cross-grids with a depth of 1.2mm. The surface roughness is preset to Ra3.2μm for thermoplastic materials or Ra1.6μm for thermosetting materials to increase friction with the prepreg filaments and prevent slippage.

[0085] Structural rigidity assurance: 6061 aluminum alloy end face sealing plate with a thickness of 8mm is used. The end face of the torque motor is rigidly attached to the surface of the coated roll with 4 M6 hex bolts. The flatness error is controlled within ≤0.03mm to ensure that the power transmission is smooth.

[0086] (2) Radial adjustment device:

[0087] Adjustment mechanism: High-precision ball screw linear guide, model HIWINKK86, is selected and installed inside the segmented pressure roller. The guide slider and the end face sealing plate are connected by gapless bolts with a fit tolerance of H7 / g6, achieving a radial adjustment range of ±5mm.

[0088] Drive and precision: Driven by a 57-type servo motor with a 1024-line encoder, the thrust is output through a reducer with a reduction ratio of 5:1 and an adjustment resolution of 0.001mm, which can meet the real-time pressure compensation requirements for ply thickness variations of 0.1-5mm.

[0089] (3) Heating module and sealing chamber

[0090] Heating element: Uses nickel-chromium heating resistance wire with a diameter of 0.5mm, wound on an insulating ceramic skeleton on the inner side of the roll-pressed surface. The single-section heating power is 150W, and the heating rate can reach 5℃ / s, which meets the heating requirements of thermoplastic materials (melting temperature 180-250℃) and thermosetting materials (curing temperature 80-180℃).

[0091] Sealing and insulation: The inner side of the roller-pressed surface and the mica insulation board form a sealed chamber. The insulation board is 2mm thick and filled with glass fiber insulation cotton with a density of 48kg / m³. The heat loss rate is controlled to ≤5%. The edge of the sealed chamber is sealed with a high-temperature resistant silicone rubber sealing ring with a temperature resistance of 300℃ to prevent dust from entering.

[0092] (4) Sensor configuration

[0093] Temperature sensor: A PT100 platinum resistance sensor is embedded in the sealed chamber. It has an accuracy of Class A and an error of ±0.15℃. It monitors the temperature of the heating area in real time and has a sampling frequency of 10Hz.

[0094] Pressure sensor: A thin-film pressure sensor, model TekscanFlexiforceA201, is attached to the contact point between the roller surface and the base plate. It has a thickness of 0.2mm, a measurement range of 0-50N, an accuracy of ±2%FS, a sampling frequency of 50Hz, and captures instantaneous pressure fluctuations.

[0095] (5) Control module and closed-loop system

[0096] Hardware core: It adopts an ARM Cortex-M7 microcontroller, model STM32H743, which integrates a 16-bit ADC module and supports synchronous acquisition of multi-channel sensor signals; it communicates with the servo drivers and heating controllers of each segment via CAN bus, with a response delay of ≤10ms.

[0097] Control Algorithm: Based on a multivariable PID control algorithm, preset temperature / pressure reference values ​​are used. Process parameters from the CAD model can be imported via a host computer, and parameters can be set separately for temperature and pressure deviations.

[0098] Temperature PID: proportional coefficient Kp = 5.0, integral time Ti = 10s, derivative time Td = 0.5s;

[0099] Pressure PID: proportional coefficient Kp=8.0, integral time Ti=5s, derivative time Td=0.2s.

[0100] Closed-loop logic: When the sensor detects a temperature deviation > ±3℃ or a pressure deviation > ±1N, the control module outputs an adjustment signal within 200ms. Through the adjustment of the heating resistance wire power and the linear guide displacement compensation, the PWM duty cycle range is 0-100%, so that the parameters return to the reference value range.

[0101] Control method practice process:

[0102] Parameter preset (S1): Based on the type of prepreg, such as T700 / PEEK thermoplastic composite material, preset the following in the control module: temperature reference value 220℃, pressure reference value 15N;

[0103] Data acquisition (S2): The temperature sensor uploads the real-time temperature every 100ms, such as 218℃; the pressure sensor uploads the real-time pressure every 20ms, such as 14.5N.

[0104] Deviation calculation (S3): The control module calculates the temperature deviation as -2℃ and the pressure deviation as -0.5N;

[0105] Signal generation (S4): Control signals are generated through a multivariable PID algorithm: the power of the heating resistance wire is increased by 10% to increase the temperature, and the linear guide is positively displaced by 0.02mm to increase the pressure;

[0106] Closed-loop regulation (S5): After the actuator responds, the temperature rises to 220℃ and the pressure stabilizes to 15N within 500ms, completing one regulation cycle.

Claims

1. A segmented heated pressure roller device for a composite material fiber placement machine, comprising pressure rollers, characterized in that, Includes the following components: The segmented pressure roller is cylindrical and driven to rotate by an independent torque motor. The motion posture of each segmented pressure roller is independently controlled. Several of the segmented pressure rollers are combined together along the axial direction to form the pressure roller. A radial adjustment device is installed inside the segmented pressure roller to adjust the distance between the roller pressing surface of the segmented pressure roller and the base plate, thereby precisely controlling the roller pressing pressure; It also includes a pressure sensor located at the contact point between the roller pressing surface and the base plate, which is used to detect the contact pressure between the roller pressing surface and the material in real time during the filament laying process; A heating module is installed inside the segmented pressure roller. The roller pressing surface and the heat insulation plate inside the pressure roller together form a sealed chamber. The heating module is located in the sealed chamber and is used to heat the roller pressing surface. It also includes a temperature sensor, which is located in the sealed chamber and monitors the temperature data of the heating area in real time to provide a basis for temperature control. It also includes a control module, which establishes a communication connection with the heating module, radial adjustment device and torque motor, and regulates their operating status to achieve precise and coordinated control of the temperature, pressure and motion posture of each segmented pressure roller during the fiber laying process of complex curved surface composite material components.

2. The segmented heating roller device for a composite material fiber placement machine according to claim 1, characterized in that: The segmented pressure roller has a coating on its roller surface that contacts the material. The coating material is at least one of polyimide-based composite material, ceramic particle-reinforced silicone rubber, and bismaleimide-based composite material.

3. A segmented heating roller device for a composite material fiber placement machine according to claim 2, characterized in that: The coated roll-pressed surface has a micro-texture structure, and the surface roughness of the micro-texture structure is a preset threshold that is adjustable based on the processing parameters.

4. A segmented heating roller device for a composite material fiber placement machine according to claim 2, characterized in that: It also includes an end-face sealing plate, which rigidly connects the end face of the torque motor to the roll-pressed surface that has been coated with material; The radial adjustment device is seamlessly connected to the roll-pressed surface that has been coated with material.

5. A segmented heating roller device for a composite material fiber placement machine according to claim 1, characterized in that: The segmented pressure roller has a hollow shaft at its center, which is used to accommodate the circuit wiring of the torque motor, radial adjustment device and other components.

6. A segmented heating roller device for a composite material fiber placement machine according to claim 1, characterized in that: The segmented pressure rollers are provided with a preset gap, the preset gap value being between 0.5mm and 1mm, including 0.5mm and 1mm.

7. A control method for a segmented heating roller device for a composite material fiber placement machine as described in claim 1, characterized in that, The segmented heated pressure roller device for the composite material fiber placement machine further includes a temperature sensor and a pressure sensor; the temperature sensor is located in a sealed chamber formed by the roller pressing surface and the heat insulation plate inside the roller; the pressure sensor is located at the contact point between the roller pressing surface and the base plate; the control method includes the following steps: S1. Preset pressure reference values ​​and temperature reference values ​​in the control module; S2. Obtain real-time pressure and temperature values ​​through the temperature sensor and the pressure sensor and transmit them to the control module; S3. Calculate the pressure deviation and temperature deviation in the control module; S4. Based on the pressure deviation and temperature deviation, a control signal is generated using a multivariable PID control algorithm; S5. The radial adjustment device and heating module are driven by the control signal to form a closed-loop control system. The control signal drives the heating resistance wire to adjust the output power to achieve closed-loop temperature control, and drives the linear guide rail to adjust the radial displacement to achieve closed-loop pressure control. Finally, the temperature and pressure of each segmented pressure roller are stabilized within the preset reference value range.

8. A composite material fiber placement machine, characterized in that, include: A segmented heated pressure roller device for a composite material fiber placement machine according to any one of claims 1-6.

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