A composite material laser cladding device and a laser cladding method thereof

Abstract

The application discloses a kind of composite laser cladding device and its laser cladding method, the device includes: winding machine head integration, mechanical arm, motor and mounting base;Winding machine head integration is with head bottom plate as matrix, integrated with wire feeding and tension control device, laser processing and focal length adjusting device, process monitoring and visual positioning device.Wire feeding and tension control device includes: tray, tray brake motor, wire feeding motor device, wire feeding wheel system, tension sensor, wheel system adjusting cylinder, wire feeding plate, silk tape scissors, press roller device, lower pressure cylinder, solenoid valve, pressure regulating valve and angle adjusting device;Laser processing and focal length adjusting device includes: laser, focal length adjusting mechanism, laser line support, laser height adjusting slider, line laser and air blowing vortex tube;Process monitoring and visual positioning device includes: camera adjusting device and thermal imaging adjusting device.The application is integrated by modularization, compact structure, cooperates closed loop control, realizes high-precision laser cladding forming.

Description

Technical Field

[0001] This invention belongs to the field of laser processing, specifically relating to a laser cladding device and method for composite materials, particularly a highly integrated laser cladding device that integrates multiple functions such as wire feeding, tension control, laser processing, focus adjustment, morphology monitoring, temperature monitoring, gas path protection, and wire shearing into a single head plate. It is suitable for high-quality in-situ consolidation and forming of thermoplastic composite materials (such as CF / PEEK, CF / PEKK, etc.) using an automated wire placement / winding process. Background Technology

[0002] Laser cladding is an advanced surface modification and additive manufacturing technology. It uses high-energy-density laser heating to rapidly melt and solidify the cladding material onto the substrate surface, forming a metallurgically bonded cladding layer. This technology has been widely applied in the aerospace field, especially in the in-situ consolidation of thermoplastic composites. Laser heating, with its advantages of high energy density, rapid response, and non-contact heating, has become the mainstream heating method for automated fiber placement (AFP) and automated winding (ATL) processes.

[0003] In the field of laser cladding technology, various devices have been disclosed. For example, Chinese patent application CN201710849553.8 discloses a laser cladding device, which includes a wire feeder, a nozzle, and a wire guide tube. The wire guide tube connects the wire feeder and the nozzle and passes through the nozzle. An upper sealing gasket and a lower sealing gasket are provided at the point where the wire guide tube passes through the nozzle. The lower sealing gasket is mounted on a support base and its position is adjustable, while the upper sealing gasket is mounted on a support cover. A beam splitter and a reflecting focusing mirror are installed inside the nozzle to achieve beam reflection and focusing. This device arranges the wire feeder and nozzle vertically, reducing the device size to some extent, and solves the problem of wire feeding resistance changes caused by bending of the wire feeding hose by adjusting the position of the sealing gasket. However, the prior art has the following drawbacks: First, the integration of functions is insufficient, and there is a lack of process monitoring methods. For example, the laser cladding device disclosed above only integrates wire feeding and laser processing functions, without integrating any process monitoring sensors. In the actual cladding process, key process parameters such as melt pool temperature and cladding layer morphology cannot be obtained in real time. Operators find it difficult to detect cladding defects in a timely manner, and cannot adjust process parameters in real time, resulting in difficulty in ensuring the consistency of molding quality.

[0004] Second, it lacks closed-loop control capabilities. Due to the lack of real-time monitoring data, the device cannot achieve closed-loop adaptive control of the process. When changes in external conditions (such as changes in substrate heat dissipation conditions, batch differences in wire materials, etc.) cause fluctuations in cladding quality, the device cannot adjust parameters autonomously and relies on operator experience for post-process adjustments, resulting in low efficiency and poor reliability.

[0005] Third, the dispersed sensor layout makes it difficult to guarantee the optimal monitoring angle. If additional monitoring sensors are to be added to this device, they usually need to be installed separately, which not only makes the overall structure bulky, but also makes it difficult to guarantee the relative positional stability of the sensors and the processing point and the optimal monitoring angle.

[0006] Fourth, the device was not optimized for composite material winding processes. Primarily designed for general laser cladding applications, it did not consider the specific requirements of composite material winding processes, such as constant wire tension control, precise monitoring of the cladding layer morphology, and precise control of the molten pool temperature.

[0007] To address the shortcomings of the existing technologies, this invention provides a highly integrated and modular composite material laser cladding device that integrates functions such as wire feeding, tension control, laser processing, focus adjustment, morphology monitoring, and temperature monitoring onto the same substrate. It is also equipped with a multi-sensor closed-loop control method to solve the problems of dispersed functions, uncontrollable processes, and difficulty in adapting to the requirements of composite material winding molding processes in the existing technologies. Summary of the Invention

[0008] Purpose of the invention: The purpose of this invention is to provide a composite material laser cladding device and laser cladding method that is compact in structure, functionally integrated, and easy to implement closed-loop control, so as to solve the problems of dispersed functional modules, bulky structure, and difficulty in achieving precise process control in the prior art.

[0009] Technical solution: To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a composite material laser cladding device, comprising: a winding machine head integration, a robotic arm, a motor, and a mounting base; The winding machine head assembly includes a head base plate, as well as a wire feeding and tension control device, a laser processing and focus adjustment device, and a process monitoring and vision positioning device integrated on the head base plate. The head base plate is a flat structure made of high-strength, lightweight material, serving as a common mounting base for all functional components.

[0010] The head base plate is made of aluminum alloy or titanium alloy and its surface is precision machined to ensure a flatness of not less than 0.03 mm / m, thus ensuring the installation reference accuracy of each functional module.

[0011] In some embodiments, the wire feeding and tension control device, the laser processing and focus adjustment device, and the process monitoring and visual positioning device are arranged on the head base plate as follows: the wire feeding and tension control device occupies one side of the base plate, the laser processing and focus adjustment device occupies the other side, and the process monitoring and visual positioning device is located in the area between the two, ensuring that the processing and monitoring lines of each functional module do not interfere with each other. This arrangement allows the wire feeding outlet, laser focus, camera field of view center, and thermal imager monitoring point to converge at the same spatial processing point, achieving precise alignment of the "four centers in one" and ensuring the synchronization of processing and monitoring.

[0012] In some embodiments, the filament feeding and tension control device includes: a filament tray, a filament tray brake motor connected to the filament tray, a filament feeding motor device, a filament feeding wheel system driven by the filament feeding motor, a tension sensor disposed on the filament feeding path, a wheel system adjusting cylinder connected to the filament feeding wheel system, a filament feeding plate for guiding the filament, and a filament cutting tool disposed near the filament feeding plate; the filament tray is used to load the composite material filament to be processed, is rotatably mounted on the upper area of ​​the head base plate, and is supported by a bearing seat to ensure smooth unwinding; the filament tray brake motor is coaxially connected to the filament tray or connected through a transmission mechanism to provide controllable unwinding damping to prevent the filament from loosening in the non-working state, and to maintain the filament tension through reverse torque during working; the filament tray brake motor and the filament feeding motor device adopt master-slave cooperative control: the filament feeding motor device is the master drive, and the filament tray brake motor provides adjustable damping torque, and the two work together to maintain constant tension of the filament during unwinding; when the filament feeding motor stops, the filament tray brake motor immediately locks to prevent the filament from loosening due to inertia; The wire feeding motor, fixed to the head base plate, is the core power source for wire feeding, ensuring precise control of the wire feeding speed. The wire feeding wheel system, connected to the output shaft of the wire feeding motor, includes an active wire feeding wheel and a driven pressure wheel, driving the wire forward precisely through friction between the wheels. A tension sensor detects the wire tension in real time and feeds the signal back to the control system, achieving closed-loop tension control. The wheel system adjusting cylinder is connected to the driven pressure wheel in the wire feeding wheel system, used to loosen the pressure wheel during wire threading or maintenance for easy operation, while maintaining a pressed state during operation. The end of the wire feeding plate is equipped with a precision-machined wire feeding guide nozzle, from which the wire is ultimately precisely guided towards the laser focal area. The ribbon scissors are used to quickly cut the wire.

[0013] In some embodiments, the yarn feeding and tension control device further includes: a pressure roller device, a pressing cylinder connected to the pressure roller device, and a solenoid valve and a pressure regulating valve for controlling pneumatic components; the pressure roller device is installed on the yarn path after the yarn feeding wheel system to further press and guide the yarn, ensuring that the yarn enters the subsequent guiding components straight; the pressing cylinder drives the pressure roller to switch between pressing and releasing; the solenoid valve is used to control the on / off of the air circuit; and the pressure regulating valve is used to regulate the air pressure.

[0014] In some embodiments, the wire feeding and tension control device further includes an angle adjustment device mounted on the wire feeding path for fine-tuning the wire feeding angle. The angle adjustment device can be fine-tuned around multiple axes to precisely adjust the angle of the wire feeding guide nozzle, ensuring that the wire enters the molten pool in the optimal posture.

[0015] In some embodiments, a pressure sensor is also provided between the pressure roller device and the lower pressure cylinder to detect the pressure value applied by the pressure roller to the cladding layer in real time and feed it back to the control system to form a pressure closed-loop control. The pressure adjustment range is 20-200MPa to ensure that the composite material layers obtain a uniform compaction effect and reduce the interlayer porosity.

[0016] In some embodiments, the laser processing and focus adjustment device includes: a laser, a focus adjustment mechanism, a laser line support, a laser height adjustment slider, a line laser, and an air-blowing vortex tube; the laser is connected via optical fiber and fixed to the head base plate, serving as the energy source for the cladding operation, with its light outlet pointing towards the intersection of the wire guide nozzles on the wire feed plate; the focus adjustment mechanism is located on the laser's light output path and is used to dynamically change the position of the laser focus on the workpiece surface to adapt to different processing heights or process parameter requirements; the focus adjustment mechanism includes a set of focusing lenses movable along the optical axis and their driving mechanism, the driving mechanism preferably being a lead screw driven by a servo motor. The laser beam is supported by a block mechanism or a voice coil motor direct-drive mechanism, with a focusing range of ±10mm, an adjustment accuracy of up to 0.01mm, and a response time of less than 50ms. A laser line support is fixed to the head base plate to protect related optical components. The laser height adjustment slider is a coarse adjustment mechanism for focusing, allowing for fine-tuning of the overall height of the laser beam-emitting module relative to the head base plate. The line laser projects structured light onto the cladding area, and combined with a vision sensor, enables real-time scanning of the 3D morphology of the cladding layer. A blowing vortex tube is installed near the laser's output port, with its nozzle pointing towards the laser focal area to spray protective gas, while also cooling and protecting the optical lenses from splashes. The blowing vortex tube preferably employs a vortex tube structure, which separates compressed air into cold and hot air streams. The cold air stream is directed towards the optical lenses for cooling, while the hot or room-temperature air stream is directed towards the molten pool for protection, achieving integrated utilization of the gas source. The protective gas flow rate is controlled by a mass flow meter, ranging from 5-25L / min, and dynamically adjusted according to the cladding material and speed.

[0017] In some embodiments, the process monitoring and visual positioning device includes: a camera adjustment device and a thermal imaging adjustment device; the camera adjustment device is equipped with a camera, which works in conjunction with a line laser for monitoring the cladding layer morphology. The camera is used to acquire two-dimensional images of the processing area, which can be used for workpiece feature recognition, weld seam tracking and positioning, and three-dimensional morphology reconstruction in conjunction with the line laser; the camera is preferably an industrial CMOS camera with a resolution of 5 million pixels or more, a frame rate of not less than 60fps, and equipped with a narrowband filter (the center wavelength matches the wavelength of the line laser) to filter out strong light interference from the molten pool and improve imaging quality; An infrared thermal imager is mounted on the thermal imaging adjustment device. The imager is tilted at a certain angle towards the laser focal area, and its optical axis is used to monitor the temperature field distribution of the molten pool and heat-affected zone in real time. The infrared thermal imager is preferably an uncooled focal plane detector with a temperature measurement range of 200℃-2000℃, a measurement accuracy of ±2℃ or ±2% of the reading, a frame rate of not less than 50Hz, and a response band of 8-14μm or a band that does not overlap with the laser wavelength to avoid laser reflection interference.

[0018] In some embodiments, a robotic arm is fixedly mounted on the mounting base, and the winding machine head is integrated and fixedly mounted on the end of the robotic arm; a motor is fixedly mounted at the joint of the robotic arm to provide power for the movement of the robotic arm. The robotic arm is preferably a 6-axis industrial robot with a rated load of not less than 50 kg, an arm span of 1500-2700 mm, a repeatability of ±0.06 mm, and an absolute positioning accuracy of ±0.1 mm, enabling precise movement of complex trajectories with multiple degrees of freedom.

[0019] On the other hand, the present invention also provides a method for laser cladding of composite materials using the above-mentioned device, comprising the following steps: Step S1, Device Installation and Calibration: Integrate the winding machine head onto the end of the robotic arm and perform initial calibration of each functional component, including: calibrating the wire feeding path to ensure smooth wire delivery; calibrating the laser path to ensure accurate focus position; and calibrating the field of view of the camera and thermal imager to ensure that the monitoring area covers the molten pool. Step S2, Threading: Install the composite material filament on the material tray. The filament passes through the tension sensor, the filament feeding wheel system, the pressure roller device, and the filament feeding plate to complete the threading. During the threading process, the driven pressure roller can be loosened by the wheel system adjustment cylinder to facilitate threading. The specific operation process of threading is as follows: ① Install the material tray (121) on the material tray shaft and tighten the locking nut; ② Manually pull out the filament head and pass it around the guide wheel of the tension sensor (125) in sequence; ③ Drive the wheel system adjustment cylinder (126) through the control system to lift the driven pressure roller and pass the filament head between the driving wheel and the driven wheel of the filament feeding wheel system (124); ④ Reset the wheel system adjustment cylinder (126) to press the pressure roller to tighten the filament; ⑤ Pass the filament head through the guide nozzle of the pressure roller device (129) and the filament feeding plate (127) so that the filament head extends 5-10mm out of the guide nozzle and is ready. Step S3, Positioning: Start the system and control the robotic arm to move the winding machine head to the working starting position. Determine the cladding starting point based on the workpiece 3D model and the preset path. Step S4, cladding operation: Drive the wire feeding motor to accurately deliver the wire to the laser focal area; at the same time, start the laser, and after being focused by the focus adjustment mechanism, clad the wire onto the workpiece surface. The robotic arm moves according to the preset trajectory to achieve continuous cladding. Step S5, Real-time monitoring: During the cladding process, a line laser projects line structured light into the cladding area, and the camera on the camera adjustment device receives the reflected light to acquire the three-dimensional morphology data of the cladding layer in real time; the infrared thermal imager on the thermal imaging adjustment device monitors the temperature field of the molten pool in real time and acquires temperature distribution data. Step S6, Closed-loop control: The three-dimensional topography data and temperature distribution data collected in step S5 are fed back to the control system. The control system compares the preset process parameters in real time and dynamically adjusts the wire feeding speed, laser power, focal length position or robotic arm motion parameters to achieve closed-loop adaptive control. Step S7, Repeat until completion: Repeat steps S4-S6, cladding layer by layer according to the preset path until the entire cladding operation is completed. After each layer is cladding, the control system automatically retrieves the topographic data from the line laser and camera, compares it with the CAD model, and if a local thickness deviation exceeding ±0.1mm or a pore / void defect is detected, a compensation path is automatically generated or the processing is paused with an alarm to ensure that the quality between layers is controllable.

[0020] In some implementations, step S6, the closed-loop adaptive control includes: a. Shape closed-loop control: Based on the 3D point cloud data acquired by line laser and camera, calculate the deviation from the preset model, generate normal compensation command for the robot arm trajectory, and ensure uniform cladding layer thickness; b. Temperature closed-loop control: Based on the temperature distribution data obtained by the infrared thermal imager, determine whether the peak temperature of the molten pool and the width of the heat-affected zone are within the preset process window. If not, adjust the laser power or the movement speed of the robotic arm to ensure the cladding quality. c. Tension closed-loop control: Based on the data from the tension sensor, the output torque of the wire feeding motor is adjusted to maintain constant wire feeding tension and ensure stable wire feeding.

[0021] d. Pressure closed-loop control: Based on the pressure data fed back by the pressure sensor set between the pressure roller device and the lower pressure cylinder, the air pressure of the lower pressure cylinder is adjusted to keep the pressure applied by the pressure roller to the cladding layer within the preset range, so as to ensure that the composite material layers obtain a uniform compaction effect and reduce the interlayer porosity.

[0022] Beneficial effects: Compared with the prior art, the present invention has the following advantages: (1) The laser cladding device of the present invention achieves high-precision, high-quality automated molding of composite material laser cladding through modular integrated design and multi-sensor closed-loop control method, which has significant practical value and innovation.

[0023] (2) The laser cladding device of the present invention integrates many functional units such as wire feeding, tension control, laser processing, focal length adjustment, morphology monitoring, temperature monitoring, gas path protection, and wire shearing into the same head base plate. It has a compact structure, saves space, is easy for robots to carry, and is crucial to ensuring long-term processing accuracy.

[0024] (3) The laser cladding device of the present invention comprises three major functional modules: a wire feeding and tension control device, a laser processing and focus adjustment device, and a process monitoring and visual positioning device. Each device is relatively independent yet works in concert, with a clear and reasonable layout that facilitates assembly, debugging, and subsequent maintenance. The layout allows the wire feeding outlet, laser focus, camera field of view center, and thermal imager monitoring point to converge at the same processing point in space, achieving precise alignment of the "four centers in one" and ensuring the synchronization of processing and monitoring.

[0025] (4) The laser cladding device of the present invention also integrates a tension sensor, a line laser, a camera adjustment device and a thermal imaging adjustment device, providing a reliable hardware platform for real-time closed-loop adaptive control and significantly improving the consistency of molding quality.

[0026] (5) The laser cladding device of the present invention has a monitoring sensor installed by an independent adjustment device, which can optimize the monitoring angle for different working conditions and improve the monitoring accuracy.

[0027] (6) The laser cladding device of the present invention realizes real-time perception and adaptive adjustment of the cladding process through the three closed-loop control method of morphology, temperature and tension, which significantly improves the molding quality and process stability of composite materials. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the overall structure of the composite material laser cladding device of the present invention; Figure 2 This is a schematic diagram of the robot structure of the composite material laser cladding device of the present invention; Figure 3 This is a schematic diagram of the front structure of the laser head integrated in the composite material laser cladding device of the present invention; Figure 4 This is a schematic diagram of the back structure of the laser head integrated in the composite material laser cladding device of the present invention; Figure 5 This is a schematic diagram of the overall installation structure of the composite material laser cladding device of the present invention; Figure 6 For the present invention Figure 5 A magnified schematic diagram of the structure of part A in the diagram; Figure 7 This is a schematic diagram of the laser cladding method for composite materials according to the present invention; In the diagram: 1. Wrapping machine head integration; 2. Robotic arm; 3. Motor; 4. Mounting base; 5. Guide rail platform; 11. Head base plate; 12. Wire feeding and tension control device; 13. Laser processing and focus adjustment device; 14. Process monitoring and vision positioning device; 101. M8 bolt; 102. Flange; 121. Material tray; 122. Material tray brake motor; 123. Wire feeding motor device; 124. Wire feeding wheel system; 125. Tension sensor; 126. Wheel system adjustment cylinder; 127. Wire feeder; 128. Wire cutter; 129. Pressure roller device; 1210. Pressing cylinder; 1211. Solenoid valve; 1212. Pressure regulating valve; 1213. Angle adjustment device; 131. Laser; 132. Focus adjustment mechanism; 133. Laser line bracket; 134. Laser height adjustment slider; 135. Line laser; 136. Air blowing vortex tube; 141. Camera adjustment device; 142. Thermal imaging adjustment device; 501. Pin; 502. M30 bolt. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] This embodiment uses CF / PEKK UD prepreg tape as a typical processing material. This material is a high-performance thermoplastic composite material with a long-term service temperature exceeding 250°C. It can be used in aerospace, military, medical, and automotive industries, and can be formed using processes such as hot pressing, winding (in-situ curing), and automated layup (in-situ curing). This material has excellent mechanical properties, low water absorption, high hygrothermal performance, excellent chemical and solvent resistance, good flame retardancy, and indefinite shelf life at room temperature.

[0031] Regarding material quality, prepregs must have uniform resin distribution, parallel and continuous fibers without obvious wrinkles or crossings, and a surface free of foreign matter. Permissible defects include: fiber gaps not exceeding 250mm in length and 1.2mm in width; cleaned lint marks; and lint clumps not exceeding 0.05mm in thickness and less than 3cm² in size (less than 1 clump per 30 meters). Prepregs must include defect markings indicating the defect type; defective portions are not included in the delivery quantity.

[0032] The performance parameters of this material are as follows: 1. The density of CF / PEKK resin is 1.28 g / cm³, the glass transition temperature Tg is 160℃, the melting temperature Tm is 310℃, the molding temperature Tp range is 350-380℃, and the tensile strength is 95 MPa.

[0033] 2. The carbon fiber is of T700 grade or equivalent, with a tensile strength of 4900MPa, tensile modulus of 230GPa, elongation of 2.0%, and density of 1.8g / cm³.

[0034] 3. The fiber areal density of the prepreg is 160g / ㎡ (145-200gsm can be customized), the prepreg areal density is 242g / ㎡, the resin mass content is 34%±3% (30-60% can be customized), the single layer thickness (after molding) is about 0.15mm, the laminate density is 1.56g / cm³, the width is 6.35-300mm (customizable), and the length is greater than 100 meters (maximum 600 meters / roll).

[0035] In this embodiment, the mechanical properties (room temperature dry RTD) of the composite laminate are as follows: the 0° tensile strength is 2200 MPa and the 0° tensile modulus is 120 GPa, measured according to ASTM D3039; the 0° compressive strength is 1350 MPa and the 0° compressive modulus is 120 GPa, measured according to ASTM D6641; and the short beam shear strength is 100 MPa, measured according to ASTM D2344.

[0036] The apparatus and method of this invention employ a one-step in-situ consolidation approach. By integrating laser heating, compaction roller pressure, and multi-parameter closed-loop monitoring and control, it aims to overcome the contradiction between laying speed and consolidation quality, achieving high-quality in-situ consolidation molding of CF / PEKK composite materials. The target is: interlayer porosity less than 2% (preferably less than 1%), and crystallinity 35-40%.

[0037] Please see Figures 1-6 This embodiment provides the following technical solution: like Figure 1-2 As shown, a composite material laser cladding device of the present invention includes: a winding machine head assembly 1, a robotic arm 2, a motor 3, and a mounting base 4. The robotic arm 2 is fixedly mounted on the mounting base 4. The winding machine head assembly 1 is the core functional module for completing the laser cladding operation, and it is fixedly mounted on the end flange 102 of the robotic arm 2 by M8 bolts 101. The robotic arm 2 is an industrial robot body used to drive the entire device to achieve multi-degree-of-freedom movement. The motor 3 is fixedly mounted at relevant joints of the robotic arm 2, providing the motion power for the robotic arm 2. In this embodiment, the robotic arm 2 is preferably a 6-axis industrial robot with a rated load of 210 kg, an arm span of 2700 mm, a repeatability of ±0.06 mm, and an absolute positioning accuracy of ±0.1 mm, enabling precise movement of complex multi-degree-of-freedom trajectories.

[0038] like Figure 3-4 As shown, the winding machine head assembly 1 adopts a modular design, using a head base plate 11 as the mounting base for the entire device. This head base plate 11 is made of high-strength, lightweight materials (such as aluminum alloy or titanium alloy), and its surface is precision-machined to achieve a flatness of no less than 0.03 mm / m, ensuring the installation accuracy of each functional module. Three main functional modules are integrated on it: a wire feeding and tension control device 12, a laser processing and focus adjustment device 13, and a process monitoring and visual positioning device 14. This modular layout allows each functional unit to work relatively independently yet collaboratively, facilitating assembly, debugging, and maintenance. This layout ensures that the wire feed outlet, laser focus, camera field of view center, and thermal imager monitoring point converge at the same spatial processing point, achieving precise alignment of the "four centers in one," ensuring the synchronization of processing and monitoring.

[0039] like Figure 3-4As shown, the wire feeding and tension control device 12 is installed on one side of the head base plate 11, responsible for stably and accurately feeding the composite material filament to the laser processing area and maintaining constant tension control. This device specifically includes the following components: a feed tray 121, a feed tray brake motor 122, a wire feeding motor device 123, a wire feeding wheel system 124, a tension sensor 125, a wheel system adjusting cylinder 126, a wire feeding plate 127, a wire cutting shear 128, a pressure roller device 129, a pressing cylinder 1210, a solenoid valve 1211, a pressure regulating valve 1212, and an angle adjusting device 1213.

[0040] In this embodiment, the tray 121 is used to load the composite material filament to be processed. It is rotatably mounted on the upper area of ​​the head base plate 11 and supported by a bearing seat to ensure smooth unwinding. The tray brake motor 122 is coaxially connected to the tray 121 or connected through a transmission mechanism to provide controllable unwinding damping, preventing the filament from loosening in the non-working state, and maintaining the tension of the filament through reverse torque during operation.

[0041] The material tray brake motor 122 and the wire feeding motor device 123 adopt master-slave cooperative control: the wire feeding motor device 123 is the main drive, and the material tray brake motor 122 provides adjustable damping torque. The two work together to keep the wire material under constant tension during unwinding. When the wire feeding motor stops, the material tray brake motor 122 immediately locks to prevent the wire material from loosening due to inertia.

[0042] The wire feeding motor 123, fixed to the head base plate 11, is the core power source for wire feeding, ensuring precise control of the wire feeding speed. The wire feeding wheel system 124, connected to the output shaft of the wire feeding motor 123, includes an active wire feeding wheel and a driven pressure wheel, driving the wire forward precisely through friction between the wheels. A tension sensor 125, located on the wire feeding path, detects the wire tension in real time and feeds the signal back to the control system, achieving closed-loop tension control. A wheel system adjusting cylinder 126, connected to the driven pressure wheel in the wire feeding wheel system 124, is used to loosen the pressure wheel during threading or maintenance for easy operation, while maintaining a pressed state during operation. The end of the wire feeding plate 127 is equipped with a precision-machined wire feeding guide nozzle, from which the wire is ultimately precisely guided towards the laser focal area. A ribbon scissors 128, installed near the wire feeding plate 127, is used to quickly cut the wire when necessary (e.g., in case of wire breakage, shutdown, or material change).

[0043] The pressure roller device 129 is installed on the filament path after the filament feeding wheel system 124 to further compress and guide the filament, ensuring that the filament enters the subsequent guiding elements straight. The pressing cylinder 1210 is connected to the pressure roller device 129, driving the pressure roller to switch between pressing and releasing. A pressure sensor is also provided between the pressure roller device 129 and the pressing cylinder 1210 to detect the pressure value applied to the cladding layer by the pressure roller in real time and feed it back to the control system to form a pressure closed-loop control. The pressure adjustment range is 20-200 MPa, ensuring uniform compaction between the composite material layers and reducing interlayer porosity.

[0044] Solenoid valve 1211 and pressure regulating valve 1212 are used to control the power source of pneumatic components (such as downdraft cylinder 1210, wheel system adjusting cylinder 126, and ribbon cutter 128). Solenoid valve 1211 controls the on / off state of the air circuit, and pressure regulating valve 1212 regulates the air pressure. Angle adjusting device 1213 is installed on the wire feeding path and can be finely adjusted around multiple axes to precisely adjust the angle of the wire feeding guide nozzle, ensuring that the wire enters the molten pool in the optimal posture.

[0045] like Figure 3-4 As shown, the laser processing and focus adjustment device 13 is installed on the other side of the head base plate 11, forming a reasonable spatial layout with the wire feeding and tension control device 12 to avoid mutual interference. This device is responsible for generating and precisely controlling the laser beam used for processing, and specifically includes the following components: laser 131, focus adjustment mechanism 132, laser wire support 133, laser height adjustment slider 134, line laser 135, and air blowing vortex tube 136.

[0046] In this embodiment, the laser 131 is connected via optical fiber and fixed to the head base plate 11, serving as the energy source for the cladding operation. In this embodiment, the laser 131 is a fiber laser with a power of 6000W, and its output port points towards the intersection of the wire guide nozzle on the wire feed plate 127. The focus adjustment mechanism 132 is located on the output path of the laser 131 and includes a set of focusing lenses movable along the optical axis and their driving mechanism. The driving mechanism is preferably a servo motor-driven lead screw and slider mechanism or a voice coil motor direct-drive mechanism, with a focusing range of ±10mm, an adjustment accuracy of up to 0.01mm, and a response time of less than 50ms. It is used to dynamically change the position of the laser focus on the workpiece surface to adapt to different processing heights or process parameter requirements. The laser wire bracket 133 is fixed to the head base plate 11 to protect the relevant optical components. The laser height adjustment slider 134 serves as a coarse adjustment mechanism for focus adjustment, enabling fine-tuning of the overall height of the laser output module relative to the head base plate 11. A line laser 135 is used to project structured light onto the cladding area, and combined with a vision sensor, it enables real-time scanning of the three-dimensional morphology of the cladding layer. An air-blowing vortex tube 136 is installed near the laser 131's output port, with its nozzle pointing towards the laser focal area. It is used to spray protective gas (such as argon) and simultaneously cools and protects the optical lenses from splashes. The air-blowing vortex tube 136 preferably employs a vortex tube structure, which can separate compressed air into cold and hot air streams. The cold air stream is directed towards the optical lenses for cooling, while the hot or ambient temperature air stream is directed towards the molten pool for protection, achieving integrated utilization of the gas source. The protective gas flow rate is controlled by a mass flow meter, ranging from 5-25 L / min, and dynamically adjusted according to the cladding material and speed.

[0047] like Figure 3-4 As shown, the process monitoring and visual positioning device 14 is mounted on the head base plate 11 via an independent adjustment device, located in the area between the wire feeding and tension control device 12 and the laser processing and focus adjustment device 13, to ensure the optimal monitoring angle. This device specifically includes the following components: a camera adjustment device 141 and a thermal imaging adjustment device 142.

[0048] In this embodiment, the camera adjustment device 141 is fixed on the head base plate 11 and is a multi-degree-of-freedom adjustable mechanism (capable of X, Y, Z and angle adjustment), on which a camera is mounted. The camera is preferably an industrial CMOS camera with a resolution of 5 megapixels or higher, a frame rate of at least 60fps, and is equipped with a narrow-band filter (center wavelength matched to the wavelength of the line laser 135) to filter out strong light interference from the molten pool and improve image quality. This camera is used to acquire two-dimensional images of the processing area and can be used for workpiece feature recognition, weld seam tracking and positioning, and three-dimensional topography reconstruction in conjunction with the line laser 135.

[0049] In this embodiment, the thermal imaging adjustment device 142 is fixed on the head base plate 11 and is also a multi-degree-of-freedom adjustable mechanism, on which an infrared thermal imager is mounted. The infrared thermal imager is preferably an uncooled focal plane detector with a temperature measurement range of 200℃-2000℃, a temperature measurement accuracy of ±2℃ or ±2% of the reading, a frame rate of not less than 50Hz, and a response band of 8-14μm or a band that does not overlap with the laser wavelength to avoid laser reflection interference. The optical axis of the thermal imager is pointed at the laser focal area at a certain tilt angle (usually 30°-60°) for real-time monitoring of the temperature field distribution of the molten pool and heat-affected zone.

[0050] The laser cladding device of the present invention integrates a tension sensor, a line laser, a camera adjustment device, and a thermal imaging adjustment device, providing a reliable hardware platform for real-time closed-loop adaptive control and significantly improving the consistency of molding quality.

[0051] like Figure 5-6 As shown, all the above components are fixedly mounted on the guide rail platform 5 via the mounting base 4, specifically using pins 501 and M30 bolts 502 for connection. The mounting base 4 and the guide rail platform 5 are positioned using high-precision pins 501 with a positioning accuracy of ±0.01mm, and secured with M30 bolts 502. The bolt strength grade is not lower than 10.9, and the tightening torque is 800-1000 N·m, ensuring the structural rigidity of the entire system and the long-term stability of the relative positions between the components. The laser cladding device of this invention uses an independent adjustment device to install monitoring sensors, which can optimize the monitoring angle for different working conditions and improve monitoring accuracy. The signal lines of all sensors (tension sensor 125, line laser 135, camera on camera adjustment device 141, infrared thermal imager on thermal imaging adjustment device 142), as well as the control lines of all actuators (material tray brake motor 122, wire feeding motor device 123, focus adjustment mechanism 132, solenoid valve 1211, etc.), are all connected to the external control system via cables through the electrical interface integrated at the tail of the device by the drag chain system.

[0052] The laser cladding device of the present invention integrates many functional units such as wire feeding, tension control, laser processing, focus adjustment, morphology monitoring, temperature monitoring, gas path protection, and wire shearing into the same head base plate. It has a compact structure, saves space, is easy for robots to carry, and is crucial for ensuring long-term processing accuracy.

[0053] Based on the above technical solution, this embodiment provides a method for laser cladding of composite materials, such as... Figure 7 As shown, it includes the following steps: Step S1, Device Installation and Calibration: Fix the winding machine head assembly 1 to the end of the robotic arm 2, and perform initial calibration of each functional component. This includes: calibrating the wire feeding path to ensure smooth wire delivery; calibrating the laser beam path to ensure accurate focus; and calibrating the field of view of the camera and thermal imager to ensure the monitoring area covers the molten pool.

[0054] Step S2, Threading: The composite material filament is installed on the material tray 121. The filament passes through the tension sensor 125, the thread feeding wheel system 124, the pressure roller device 129, and the thread feeding plate 127 to complete the threading. During the threading process, the driven pressure roller can be loosened by the wheel system adjusting cylinder 126 to facilitate threading. The specific threading operation procedure is as follows: ① Install the material tray 121 on the material tray shaft and tighten the locking nut; ② Manually pull out the filament end and pass it around the guide roller of the tension sensor 125 in sequence; ③ Drive the wheel system adjusting cylinder 126 through the control system to lift the driven pressure roller and pass the filament end between the driving roller and the driven roller of the thread feeding wheel system 124; ④ Reset the wheel system adjusting cylinder 126 to press the pressure roller to tighten the filament; ⑤ Pass the filament end through the guide nozzle of the pressure roller device 129 and the thread feeding plate 127, so that the filament end extends 5-10mm beyond the guide nozzle, and it is ready.

[0055] Step S3, Positioning: Start the system and control the robotic arm 2 to move the winding machine head assembly 1 to the working starting position. Determine the cladding starting point based on the workpiece 3D model and the preset path.

[0056] Step S4, Cladding Operation: The drive wire feeding motor 123 precisely feeds the CF / PEKK strip to the laser focal area; simultaneously, the laser 131 is activated, and after focusing by the focus adjustment mechanism 132, the strip is clad onto the workpiece surface. A rectangular spot laser heating method is used to heat the strip above the melting point of the PEKK matrix, with a target temperature range of 350-400℃. The robotic arm 2 moves along a preset trajectory to achieve continuous cladding. A compaction roller applies a pressure of 30-50 bar to the cladding area (adjusted according to the single-layer thickness of 0.15 mm and the number of layers) to ensure tight adhesion between layers, expel gas, and achieve low porosity. During the cooling process, the cooling rate is controlled to optimize crystallinity, with a target crystallinity of 35-40%.

[0057] Step S5, Real-time Monitoring: During the cladding process, the line laser 135 projects line structured light into the cladding area, and the camera on the camera adjustment device 141 receives the reflected light to acquire real-time three-dimensional morphology data of the cladding layer; the infrared thermal imager on the thermal imaging adjustment device 142 monitors the temperature field of the molten pool in real time and acquires temperature distribution data. For CF / PEKK, the focus is on monitoring the peak temperature of the molten pool (target range 360-400℃) and the width of the heat-affected zone (target 3-8mm) to avoid material overheating and degradation or incomplete melting.

[0058] Step S6, Closed-Loop Control: The three-dimensional topography data and temperature distribution data collected in step S5 are fed back to the control system. The control system compares the data with preset process parameters in real time and dynamically adjusts the wire feeding speed, laser power, focal length position, or robotic arm motion parameters to achieve closed-loop adaptive control. Specifically, this includes four closed loops: a. Shape closed-loop control: Based on the 3D point cloud data (no less than 500 points per frame) acquired by the line laser 135 and camera, calculate the deviation from the preset model (allowable deviation is ±0.1mm), generate normal compensation command for the robot arm trajectory (compensation frequency is 10Hz), ensure uniform cladding layer thickness, and avoid local excessive thickness or gaps.

[0059] b. Temperature Closed-Loop Control: Based on temperature field data acquired by an infrared thermal imager, the peak temperature of the molten pool (preset to 360-400℃ for CF / PEKK) and the width of the heat-affected zone (preset to 3-8mm) are extracted. The system determines whether the temperature is within the preset process window: if the peak temperature is too high (>400℃), the laser power is reduced (adjusted in 50W increments) or the laying speed is increased to prevent PEKK degradation; if it is too low (<360℃), the laser power is increased or the speed is reduced to ensure complete melting; if the heat-affected zone is too wide, the robotic arm movement speed is increased (adjusted in 1mm / s increments); if it is too narrow, the movement speed is reduced. The control cycle is 0.5s. This closed loop helps to achieve uniform crystallinity and low porosity.

[0060] c. Tension closed-loop control: Based on the data from the tension sensor 125 (preset tension range is 5-20N, fluctuation is allowed ±0.5N), the output torque of the wire feeding motor device 123 is adjusted (PID parameters: proportional coefficient Kp=0.8, integral time Ti=0.1s, derivative time Td=0.02s) to maintain constant wire feeding tension and prevent CF / PEKK strip from being stretched or deformed or resin from being extruded.

[0061] d. Pressure closed-loop control: Based on the pressure data fed back by the pressure sensor set between the pressure roller device 129 and the lower pressure cylinder 1210, the air pressure of the lower pressure cylinder 1210 is adjusted to keep the pressure applied to the cladding layer by the pressure roller within the preset range (the preset pressure range is 30-50 bar, and the fluctuation is allowed to be ±2 bar), so as to ensure that the composite material interlayer obtains a uniform compaction effect and reduce the interlayer porosity.

[0062] Step S7, Repeat until completion: Repeat steps S4-S6, cladding layer by layer according to the preset path until the entire cladding operation is completed; the thickness of each cladding layer is 0.3-1.0mm (corresponding to the thickness of 1-3 layers of prepreg). Wait for the cladding layer to cool to below 160℃ or below 100℃ (PEKK glass transition temperature) before proceeding to the next layer to avoid thermal stress accumulation, until the entire cladding operation is completed. After each cladding layer is completed, the control system automatically retrieves the topographic data from the line laser (135) and camera, compares it with the CAD model, and if a local thickness deviation exceeding ±0.1mm or a pore / void defect is detected, a compensation path is automatically generated or processing is paused with an alarm to ensure controllable interlayer quality. For typical CF / PEKK components, the total number of cladding layers can reach 50-200 layers, and the interlayer bonding strength is verified through short beam shear tests, with a target value ≥90MPa.

[0063] The laser cladding device of the present invention achieves real-time sensing and adaptive adjustment of the cladding process through a three-closed-loop control method of morphology, temperature and tension, which significantly improves the molding quality and process stability of composite materials.

[0064] Laser cladding experiments on composite materials were conducted using the apparatus and method of this invention. The results showed that: the robot's maximum load was 210 kg, its arm span was 2700 mm, its repeatability was ±0.06 mm, its winding tension accuracy was ±5%*FS, its prepreg width was 12.7 mm (expandable), its pressure ranged from 20 MPa to 200 MPa, its maximum layup speed was 0.4 m / s, its cladding layer thickness uniformity could be improved by more than 35%, its melt pool temperature fluctuation range could be controlled within ±15℃, its wire feeding tension fluctuation range could be controlled within ±0.5 N, its equipment debugging time could be shortened by more than 50%, and its internal porosity in the molded component could be reduced to below 1%.

[0065] In summary, the laser cladding device of the present invention achieves high-precision, high-quality automated molding of composite materials (especially thermoplastic materials such as CF / PEKK) through modular integrated design and multi-sensor closed-loop control method.

[0066] All parts not described in this invention are the same as or can be implemented using existing technology. Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A laser cladding device for composite materials, characterized in that: include: The winding machine head integrates (1), robotic arm (2), motor (3) and mounting base (4); The winding machine head integration (1) includes: a head base plate (11), and a wire feeding and tension control device (12), a laser processing and focus adjustment device (13), and a process monitoring and visual positioning device (14) integrated on the head base plate (11). The head base plate (11) is a flat plate structure made of high-strength lightweight material, serving as a common mounting base for all functional components.

2. The composite material laser cladding device according to claim 1, characterized in that: The layout of the wire feeding and tension control device (12), the laser processing and focus adjustment device (13), and the process monitoring and visual positioning device (14) on the head base plate (11) is as follows: the wire feeding and tension control device (12) occupies one side of the base plate, the laser processing and focus adjustment device (13) occupies the other side of the base plate, and the process monitoring and visual positioning device (14) is located in the area between the two, so that the processing and monitoring lines of each functional module do not interfere with each other.

3. The composite material laser cladding device according to claim 1, characterized in that: The wire feeding and tension control device (12) includes: a feed tray (121), a feed tray brake motor (122) connected to the feed tray, a wire feeding motor device (123), a wire feeding wheel system (124) driven by the wire feeding motor device (123), a tension sensor (125) disposed on the wire feeding path, a wheel system adjusting cylinder (126) connected to the wire feeding wheel system (124), a wire feeding plate (127) for guiding the wire, and a ribbon scissors (128) disposed near the wire feeding plate (127); the feed tray (121) is used to load the composite material wire to be processed and is rotatably mounted on the upper area of ​​the head base plate (11); the feed tray brake motor (122) is coaxially connected to the feed tray (121) or The wire feeding motor (123) is fixed on the head base plate (11) and connected by a transmission mechanism. The wire feeding wheel system (124) is connected to the output shaft of the wire feeding motor (123) and includes an active wire feeding wheel and a driven pressure wheel. The friction between the wheel system drives the wire to be fed forward. The tension sensor (125) is used to detect the wire tension in real time and feed the signal back to the control system. The wheel system adjustment cylinder (126) is connected to the driven pressure wheel in the wire feeding wheel system (124) and is used to drive the pressure wheel to loosen during wire threading or maintenance. The end of the wire feeding plate (127) is provided with a wire feeding guide nozzle, from which the wire is finally discharged and points to the laser focus area. The ribbon scissors (128) are used to quickly cut the wire.

4. The composite material laser cladding device according to claim 3, characterized in that: The wire feeding and tension control device (12) further includes: a pressure roller device (129), a pressing cylinder (1210) connected to the pressure roller device (129), and a solenoid valve (1211) and a pressure regulating valve (1212) for controlling pneumatic components; the pressure roller device (129) is installed on the wire path after the wire feeding wheel system (124) for further pressing and guiding the wire; the pressing cylinder (1210) drives the pressure roller to switch between pressing and releasing; the solenoid valve (1211) is used to control the opening and closing of the air path; the pressure regulating valve (1212) is used to regulate the air pressure.

5. The composite material laser cladding device according to claim 3, characterized in that: The wire feeding and tension control device (12) further includes an angle adjustment device (1213), which is installed on the wire feeding path and is used to finely adjust the wire feeding angle.

6. The composite material laser cladding device according to claim 1, characterized in that: The laser processing and focus adjustment device (13) includes: a laser (131), a focus adjustment mechanism (132), a laser line support (133), a laser height adjustment slider (134), a line laser (135), and an air blowing vortex tube (136); the laser (131) is connected via an optical fiber and fixed on the head base plate (11), with its light outlet pointing to the intersection of the wire guide nozzle of the wire feed plate (127); the focus adjustment mechanism (132) is set on the light output path of the laser (131) and is used to dynamically change the position of the laser focus on the workpiece surface; the laser line support (133) is fixed on the head base plate (11); the laser height adjustment slider (134) is a coarse adjustment mechanism for focus adjustment; the line laser (135) is used to project line structured light into the cladding area; the air blowing vortex tube (136) is installed near the light output port of the laser (131), with its air outlet pointing to the laser focus area.

7. The composite material laser cladding device according to claim 6, characterized in that: The process monitoring and visual positioning device (14) includes: a camera adjustment device (141) and a thermal imaging adjustment device (142); a camera is installed on the camera adjustment device (141), and the camera is used in conjunction with the line laser (135) for monitoring the morphology of the cladding layer; an infrared thermal imager is installed on the thermal imaging adjustment device (142), and the infrared thermal imager is used for monitoring the temperature field of the molten pool.

8. The composite material laser cladding device according to claim 1, characterized in that: The mechanical arm (2) is fixedly installed on the mounting base (4), and the winding machine head integration (1) is fixedly installed at the end of the mechanical arm (2); the motor (3) is fixedly installed at the joint of the mechanical arm (2) to provide power for the movement of the mechanical arm (2).

9. A composite material laser cladding method using the composite material laser cladding apparatus according to any one of claims 1-8, characterized in that: Includes the following steps: Step S1, Device Installation and Calibration: Integrate the winding machine head onto the end of the robotic arm and perform initial calibration of each functional component, including: calibrating the wire feeding path to ensure smooth wire delivery; calibrating the laser path to ensure accurate focus position; and calibrating the field of view of the camera and thermal imager to ensure that the monitoring area covers the molten pool. Step S2, threading: The composite material filament is installed on the material tray. The filament passes through the tension sensor, the filament feeding wheel system, the pressure roller device and the filament feeding plate to complete the threading. During the threading process, the driven pressure roller can be released by the wheel system adjustment cylinder to facilitate threading. Step S3, Positioning: Start the system and control the robotic arm to move the winding machine head to the working starting position. Determine the cladding starting point based on the workpiece 3D model and the preset path. Step S4, cladding operation: Drive the wire feeding motor to accurately deliver the wire to the laser focal area; at the same time, start the laser, and after being focused by the focus adjustment mechanism, clad the wire onto the workpiece surface. The robotic arm moves according to the preset trajectory to achieve continuous cladding. Step S5, Real-time monitoring: During the cladding process, a line laser projects line structured light into the cladding area, and the camera on the camera adjustment device receives the reflected light to acquire the three-dimensional morphology data of the cladding layer in real time; the infrared thermal imager on the thermal imaging adjustment device monitors the temperature field of the molten pool in real time and acquires temperature distribution data. Step S6, Closed-loop control: The three-dimensional topography data and temperature distribution data collected in step S5 are fed back to the control system. The control system compares the preset process parameters in real time and dynamically adjusts the wire feeding speed, laser power, focal length position or robotic arm motion parameters to achieve closed-loop adaptive control. Step S7: Repeat until completion: Repeat steps S4-S6, cladding layer by layer according to the preset path until the entire cladding operation is completed.

10. The laser cladding method for composite materials according to claim 9, characterized in that: In step S6, the closed-loop adaptive control includes: a. Shape closed-loop control: Based on the 3D point cloud data acquired by line laser and camera, calculate the deviation from the preset model and generate normal compensation command for the robot arm trajectory; b. Temperature closed-loop control: Based on the temperature distribution data obtained by the infrared thermal imager, determine whether the peak temperature of the molten pool and the width of the heat-affected zone are within the preset process window; otherwise, adjust the laser power or the robotic arm moving speed. c. Tension closed-loop control: Adjusting the output torque of the wire feeding motor based on data from the tension sensor; d. Pressure closed-loop control: Based on the pressure data fed back by the pressure sensor set between the pressure roller device and the lower pressure cylinder, the air pressure of the lower pressure cylinder is adjusted to keep the pressure applied by the pressure roller to the cladding layer within the preset range, so as to ensure that the composite material layers obtain a uniform compaction effect and reduce the interlayer porosity.

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