Additive manufacturing system and method for continuous fiber reinforced composite material sensors

Abstract

This invention proposes an additive manufacturing system and method for a continuous fiber reinforced composite material sensor. The additive manufacturing system comprises a frame, a screw feeding assembly, a heating assembly, a nozzle assembly, a material guiding mechanism, and a robot unit. The frame is connected to the robot unit. The screw feeding assembly is mounted on the frame. The heating assembly is mounted on the frame and located below the screw feeding assembly. The nozzle assembly includes at least a nozzle body connected to the heating assembly. The nozzle body has an axially extending discharge hole and an inclined through-hole. The axial discharge hole is coaxially arranged with the heating assembly, and the through-hole communicates with the axial discharge hole. The material guiding mechanism is connected to the through-hole. By introducing composite filaments through a single channel and achieving secondary coating within the nozzle, the integrated manufacturing of continuous fiber reinforcement and sensor integration is completed, improving the interfacial bonding performance and structural reliability of the sensor and matrix material.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing technology, and in particular to an additive manufacturing system and process for a continuous fiber reinforced composite material sensor. Background Technology

[0002] With the development of additive manufacturing technology, continuous fiber reinforced composite additive manufacturing has been widely used in aerospace, automotive, and high-performance structural component manufacturing. By introducing continuous fibers during the printing process, the mechanical properties and load-bearing capacity of components can be significantly improved.

[0003] However, existing technologies primarily focus on improving structural performance and lack the ability to monitor the service status of components in real time. In practical engineering applications, composite material components are prone to internal damage during loading, such as interlaminar debonding, fiber breakage, and microcrack propagation. Traditional methods struggle to detect this internal damage in real time.

[0004] Currently, to achieve structural health monitoring, sensors are typically embedded in the components, such as fiber optic grating (FBG) strain sensors. FBG sensors have advantages such as small size, strong resistance to electromagnetic interference, and high sensitivity, enabling accurate measurement of parameters such as strain and temperature.

[0005] However, existing fiber Bragg grating embedding technologies mainly rely on post-embedding or step-by-step manufacturing processes, such as pre-embedding optical fibers during composite material layup or embedding after molding. These methods have the following shortcomings: The process is complex and difficult to integrate with additive manufacturing processes; The sensor has poor adhesion to the substrate interface and is prone to debonding. Sensor placement is limited, making it difficult to integrate complex paths; It is difficult to achieve integrated molding of structural manufacturing and sensing functions.

[0006] Therefore, there is an urgent need for a technical solution that can simultaneously achieve continuous fiber reinforcement and sensor integration during additive manufacturing, so as to realize the integrated manufacturing of structural load-bearing and state sensing functions.

[0007] Embedded sensor technology is mainly applied in fields such as 3D printing, large shaft parts, and tire manufacturing. Optimized design enables efficient sensor integration and optimal functionality. Screw extrusion technology is a crucial technique in polymer material processing. Through the conveying and shearing action generated by screw rotation, continuous material transport, melting, plasticizing, and stable extrusion are achieved under external heating conditions. Compared to traditional filament-based fused deposition modeling (FDM), screw extrusion offers advantages such as strong material adaptability, high extrusion efficiency, direct use of granular materials, and greater suitability for processing highly filled composite materials, thus gaining increasing attention in the additive manufacturing field.

[0008] Meanwhile, continuous fiber reinforced composite sensor, due to its excellent specific strength and specific stiffness, has become an important development direction in the manufacturing of high-performance structural components. Existing continuous fiber 3D printing technologies typically rely on dedicated printheads or multi-module systems to achieve fiber-matrix composites, but these methods generally suffer from problems such as complex structures, high costs, and limited applicability.

[0009] Combining screw extrusion technology with continuous fiber-reinforced printing has become an important technical approach to improve the performance of additive manufacturing components. However, existing technologies still have the following shortcomings: First, most traditional screw extrusion systems adopt a single-channel structure, which is only suitable for extruding granular materials and makes it difficult to effectively introduce and stably mix continuous fibers; second, fibers are prone to bending, entanglement, or blockage during the conveying process, thus affecting printing stability. Summary of the Invention

[0010] In view of this, the present invention proposes an additive manufacturing system and method for a continuous fiber reinforced composite material sensor to solve the technical problems mentioned in the background art, which are mostly single-channel structures that are only suitable for extruding granular materials and are difficult to achieve effective introduction and stable mixing of continuous fibers; and the fibers are prone to bending, entanglement or blockage during the conveying process, thus affecting the printing stability.

[0011] The technical solution of this invention is implemented as follows: In a first aspect, the present invention provides an additive manufacturing system for a continuous fiber reinforced composite material sensor, comprising a frame, a screw feeding assembly, a heating assembly, a nozzle assembly, a material guiding mechanism, and a robot unit, wherein: The frame is connected to the robot unit; The screw feeding assembly is mounted on the frame and is used to supply granular material to the heating assembly; The heating component is mounted on the frame and located below the screw feeding component. It is used to heat and melt the conveyed granular material and supply it to the nozzle component. The nozzle assembly includes at least a nozzle body connected to the heating assembly. The nozzle body has an axially extending discharge hole and an inclined through-wire hole. The axial discharge hole is coaxially arranged with the heating assembly to achieve stable extrusion of molten granules. The through-wire hole is connected to the axial discharge hole to introduce composite filaments. The composite filaments are pre-compositely formed by continuous reinforcing fibers and materials with sensing functions, so that the composite filaments merge with the molten granules inside the nozzle body, forming a coating structure under the action of the molten material, and are extruded and deposited through the axial discharge hole to form a composite material component with an embedded sensor. The material guiding mechanism is connected to the through-hole and is used to constrain and guide the continuous fibers; The robot unit is used to drive the frame to achieve spatial movement of the printing path.

[0012] In some optional embodiments, preferably, the material guiding mechanism includes a feed tube and a guide core, the feed tube is connected to the through hole, the guide core is coaxially slidably disposed inside the feed tube, and the outer wall of the guide core is provided with a guide groove along the axial direction.

[0013] In some optional embodiments, preferably, the feed end of the feed tube is provided with a positioning plate, the positioning plate is provided with a positioning hole coaxial with the feed tube, and the end of the guide core away from the through hole is provided with a lifting rod, the lifting rod being slidably installed in the positioning hole.

[0014] In some alternative embodiments, preferably, the guide groove is tapered, and the diameter of the end of the guide groove near the through hole is larger than the diameter of the end of the guide groove away from the through hole.

[0015] In some alternative embodiments, preferably, the screw feeding assembly includes a drive motor and a screw, the drive motor being mounted on the frame and drivenly connected to the screw.

[0016] In some alternative embodiments, preferably, the nozzle assembly further includes a connector detachably connected to the nozzle body for connecting an external forming nozzle.

[0017] In some optional embodiments, preferably, the angle between the axis of the through hole and the axis of the axial discharge hole is 30° to 60°.

[0018] In some alternative embodiments, preferably, a storage hopper is also included, which is mounted above the heating assembly for storing granular material, and the screw feeding assembly extends into the storage hopper.

[0019] In a second aspect, the present invention provides an additive manufacturing method for a continuous fiber reinforced composite material sensor, using the additive manufacturing system for a continuous fiber reinforced composite material sensor as described in the first aspect, comprising: The screw feeding assembly supplies granular material to the heating assembly, which heats and melts the supplied granular material and then supplies it to the nozzle assembly. The continuous fibers are guided to the through-hole by the feeding mechanism; Stable extrusion of molten granules is achieved through the axial discharge hole. Composite filaments are introduced through the through hole, so that the composite filaments merge with the molten granules inside the nozzle body. Under the action of the molten material, a coating structure is formed, and the composite material component with an embedded sensor is formed by extrusion and deposition through the axial discharge hole. By setting printing parameters and printing path, the robot unit drives the frame and nozzle assembly to achieve spatial movement of the printing path, thus obtaining the printed part.

[0020] In some optional implementations, preferably, the setting of printing parameters includes: setting the layer height to 0.2~0.4mm, the path overlap rate to 0~40%, and the printing speed to 15~60mm / s; Setting the printing path includes: generating printing path data using offline programming software and converting the printing path data into a robot control program to synchronize the extrusion process with the robot's movement.

[0021] The additive manufacturing system and method for continuous fiber reinforced composite material sensors of the present invention have the following advantages over the prior art: (1) By setting an axial discharge hole and an inclined wire passage hole in the nozzle body and connecting the two inside the nozzle, the molten granules and continuous fibers can be composited in the same extrusion channel, thereby realizing the integration of granule extrusion and continuous fiber reinforcement printing. Compared with the existing technology that requires replacing the print head or multi-module collaboration, the present invention has a more compact structure and higher system integration, which can significantly simplify the equipment structure and reduce the switching complexity. Moreover, the continuous fibers are constrained and guided by the material guiding mechanism to avoid bending, entanglement or blockage of the fibers during the conveying process, thereby improving the printing stability. The present invention introduces composite filaments through a single channel and achieves secondary coating in the nozzle, thereby completing the integrated manufacturing of continuous fiber reinforcement and sensor integration. This avoids the traditional sensor post-embedding process, improves the interface bonding performance and structural reliability of the sensor and the matrix material, and is suitable for the preparation of structural health monitoring and intelligent composite material components. (2) The material guiding mechanism includes a feed pipe and a guide core. The feed pipe is connected to the through hole. The guide core is slidably disposed coaxially inside the feed pipe. The outer wall of the guide core is provided with a guide groove along the axial direction to constrain and guide the continuous fibers, so as to avoid them from entanglement or deviation during the conveying process, thereby reducing the occurrence of material blockage. (3) The guide groove is conical, and the diameter of the end of the guide groove near the through hole is larger than the diameter of the end of the guide groove away from the through hole, so that the fiber bundle can be better separated from the guide core after the fiber bundle is delivered, and the fiber bundle remaining in the guide core can be avoided from affecting subsequent use. (4) The nozzle assembly also includes a connector, which is detachably connected to the nozzle body. The connector is used to connect an external forming nozzle, which can realize the quick replacement of forming nozzles with different apertures. The aperture of the forming nozzle can be selected according to the printing requirements, thereby realizing the adjustment of extrusion linewidth, deposition accuracy and forming efficiency. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a perspective view of the additive manufacturing system for the continuous fiber reinforced composite material sensor in an embodiment of the present invention; Figure 2 This is a cross-sectional view of the additive manufacturing system for the continuous fiber reinforced composite material sensor in an embodiment of the present invention; Figure 3 This is a schematic diagram of the nozzle assembly and material guiding mechanism in an embodiment of the present invention; Figure 4 This is a schematic diagram of the material guiding mechanism in an embodiment of the present invention; Figure 5 This is a schematic flowchart of the additive manufacturing method for a continuous fiber reinforced composite material sensor according to an embodiment of the present invention; Figure 6 The displacement-load curves of the printed parts obtained with different printing parameters in the embodiments of the present invention are shown. Figure 7 This is a graph showing the tensile strength of printed parts obtained with different printing parameters in an embodiment of the present invention. Figure 8 This is a schematic diagram of the SEM end face of the printed parts obtained with different printing parameters in an embodiment of the present invention.

[0024] Explanation of reference numerals in the attached drawings: 1-Frame, 2-Screw feeding assembly, 3-Heating assembly, 4-Nozzle assembly, 5-Guiding mechanism, 6-Storage bin; 21-Drive motor, 22-Screw; 41- Nozzle body, 411- Axial discharge hole, 412- Through hole, 413- Threaded hole, 42- Connector; 51-Feed pipe, 52-Guide core, 521-Guide groove, 53-Feed hopper, 54-Positioning plate, 55-Lifting rod. Detailed Implementation

[0025] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0026] Reference Figures 1-4 As shown, a first aspect of the present invention provides an additive manufacturing system for a continuous fiber reinforced composite material sensor, comprising a frame 1, a screw feeding assembly 2, a heating assembly 3, a nozzle assembly 4, a material guiding mechanism 5, and a robot unit, wherein: The frame 1 is connected to the robot unit; the frame 1 serves as the load-bearing foundation of the system, used to support and fix each functional module. The screw feeding assembly 2 is mounted on the frame 1 and is used to supply granular material to the heating assembly 3; the screw feeding assembly 2 includes a drive motor 21 and a screw 22, the drive motor 21 is mounted on the frame 1 and is drivenly connected to the screw 22; The heating component 3 is mounted on the frame 1 and located below the screw feeding component 2. It is used to heat and melt the conveyed granular material and supply it to the nozzle component 4. The nozzle assembly 4 includes at least a nozzle body 41, which is located below the heating assembly 3 and connected to the heating assembly 3. The nozzle body 41 has an axially extending discharge hole 411 and an inclined through-wire hole 412. The axial discharge hole 411 is coaxially arranged with the heating assembly 3 to achieve stable extrusion of molten granules. The through-wire hole 412 communicates with the axial discharge hole 411 to introduce composite filaments, allowing the composite filaments to merge with the molten granules inside the nozzle body 41, thereby achieving fiber-reinforced composite extrusion. The composite filaments can be formed by pre-composite continuous reinforcing fibers and materials with sensing functions. The specific process can be one of the following two: One method involves unfolding the carbon fiber bundle and placing optical or conductive fibers in the center or on the side of the continuous reinforcing fibers, then converging them through guide wheels to form a "composite fiber bundle". Second, prepare a low-viscosity resin solution (such as PA6 solution or epoxy), put carbon fiber and sensing material into the impregnation tank at the same time, control the resin content by scraper, put them into the heating zone for drying / curing, and then roll them into composite filaments to obtain composite filaments. The material guiding mechanism 5 is connected to the through-hole 412 and is used to constrain and guide the continuous fibers; The robot unit is used to drive the frame 1 to achieve spatial movement of the printing path; In this embodiment, continuous carbon fiber bundles and optical fibers are arranged side by side through a guiding device, or the composite fiber bundles are stably conveyed through a tension control device and introduced into the through-wire hole 412 through the material guiding mechanism 5; at the same time, PA6 particles and other resin particles are heated to 240~260℃ to form a molten state through the screw feeding assembly 2; inside the nozzle, the composite fiber bundles and molten thermoplastic material merge to form a coating structure, which is extruded through the axial discharge hole 411 and deposited according to a preset path under the control of the robot unit, finally forming an integrated component with structural reinforcement and sensing functions.

[0027] In some embodiments, another process is employed, in which a fusible functional material is added to the continuous fiber, such as a conductive composite thermoplastic material, which can be one of PA6 + CNT (carbon nanotubes), PA6 + graphene, ABS + CNT, or PLA + carbon black (CB); the granular material adopts an optical / sensing microparticle composite system, which can be one of fluorescent microparticles, photosensitive particles, or microcapsule sensing materials. The continuous fiber enters through the through-hole 412, the functional molten material flows around it, forms a coating layer inside the nozzle body, and is finally extruded. For example, the fusible functional material is a conductive composite thermoplastic material, prepared by mixing PA6 matrix and carbon nanotubes at a mass fraction of 1% to 5%.

[0028] The additive manufacturing system for a continuous fiber reinforced composite material sensor proposed in this embodiment integrates granular material extrusion and continuous fiber reinforcement printing by providing an axial discharge hole 411 and an inclined through-wire hole 412 within the nozzle body 41, and connecting the two inside the nozzle. This allows molten granules and continuous fibers to be composited within the same extrusion channel, thus achieving the integration of granular material extrusion and continuous fiber reinforcement printing. Compared to existing technologies that require printhead replacement or multi-module collaboration, this invention has a more compact structure, higher system integration, significantly simplifies equipment structure, and reduces switching complexity. Furthermore, the material guiding mechanism 5 constrains and guides the continuous fibers, preventing bending, entanglement, or blockage during transport and improving printing stability.

[0029] In some embodiments, the guiding mechanism 5 includes a feed pipe 51 and a guide core 52. The feed pipe 51 is connected to the through-hole 412, and the guide core 52 is coaxially slidably disposed inside the feed pipe 51. The outer wall of the guide core 52 is provided with a guide groove 521 along the axial direction. The nozzle body 41 is provided with a threaded hole 413 coaxial with the through-hole 412. The feed pipe 51 is threadedly connected to the threaded hole 413. A trumpet-shaped feed hopper 53 is provided at the inlet of the feed pipe 51 to facilitate the introduction of fiber bundles. The guide groove 521 constrains and guides the continuous fibers, preventing them from tangling or deviating during the conveying process, thereby reducing the occurrence of material blockage.

[0030] In some embodiments, to facilitate the convenient movement and reset of the guide core 52, and to facilitate the separation of the fiber bundle from the guide core 52 after the fiber bundle is conveyed, thus preventing residual fiber bundles from affecting subsequent use, a positioning plate 54 is provided at the feed end of the feed tube 51. The positioning plate 54 has a positioning hole coaxial with the feed tube 51. A lifting rod 55 is provided at the end of the guide core 52 away from the through hole 412, and the lifting rod 55 is slidably installed in the positioning hole. The end of the lifting rod 55 away from the guide core 52 is connected to a stepper motor. The stepper motor drives the lifting rod 55 to move the guide core 52 along the feed tube 51, thereby guiding the continuous fiber to the through hole 412. The driving method can be replaced by a servo system instead of a stepper motor. The positioning plate 54 provides stable sliding support for the lifting rod 55, ensuring that the lifting rod 55 can slide smoothly. By pulling the lifting rod 55 diagonally upward, the guide core 52 can be moved diagonally upward, realizing the rapid separation of the guide core 52 from the fiber bundle. The operation is convenient and requires no additional tools.

[0031] In some embodiments, the guide groove 521 is tapered, and the diameter of the end of the guide groove 521 near the through hole 412 is larger than the diameter of the end of the guide groove 521 away from the through hole 412. This design allows for better separation of the fiber bundle from the guide core 52 after delivery, preventing residual fiber bundles from affecting subsequent use. In some embodiments, the nozzle assembly 4 further includes a connector 42, which is detachably connected to the nozzle body 41 and is used to connect an external forming nozzle. The detachable design of the connector 42 allows for quick replacement of forming nozzles with different orifice diameters, enabling the selection of the nozzle orifice diameter according to printing requirements, including but not limited to 0.4 mm, 0.6 mm, 0.8 mm, and 1.0 mm, thus allowing adjustment of extrusion linewidth, deposition accuracy, and forming efficiency. By changing the forming nozzle with different orifice diameters, flexible switching between high-precision printing and high-efficiency printing can be achieved, improving the system's adaptability.

[0032] In some embodiments, the angle between the axis of the through hole 412 and the axis of the axial discharge hole 411 is 30° to 60°. By setting the above parameters, the guiding effect of the guiding mechanism 5 can be improved, facilitating the continuous feeding of continuous fibers.

[0033] In some embodiments, a storage hopper 6 is further included, which is installed above the heating assembly 3 and is used to store thermoplastic granules. The screw feeding assembly 2 extends into the storage hopper 6. The screw 22 of the screw feeding assembly 2 extends into the storage hopper 6 and screws the granules in the storage hopper 6 to the heating assembly 3.

[0034] Based on the same concept, a second aspect of the present invention, combined with... Figures 5-8 As shown, an additive manufacturing method for a continuous fiber reinforced composite material sensor is provided, using the additive manufacturing system for a continuous fiber reinforced composite material sensor as described in the first aspect, comprising: Step S1: The screw feeding assembly 2 provides granular material to the heating assembly 3, the heating assembly 3 heats and melts the supplied granular material, and then provides it to the nozzle assembly 4; Step S2: Guide the continuous fibers to the through hole 412 through the feeding mechanism 5; Step S3: Stable extrusion of molten granules is achieved through the axial discharge hole 411, and composite filaments are introduced through the through hole 412, so that the composite filaments merge with the molten granules inside the nozzle body 41, thereby realizing fiber-reinforced composite extrusion. Step S4: Set the printing parameters and printing path, and use the robot unit to drive the frame 1 and nozzle assembly 4 to achieve spatial movement of the printing path to obtain the printed part.

[0035] In some embodiments, step S4, setting the printing parameters includes: setting the layer height to 0.2~0.4mm, the path overlap rate to 0~40%, and the printing speed to 15~60mm / s; (Refer to...) Figure 6 and Figure 7 Through actual experiments, it was found that under the following parameters during printing—a layer height of 0.2 mm, a path overlap rate of 40%, and a printing speed of 15 mm / s—material deposition was stable, interlayer bonding was good, and the overall mechanical properties of the component were optimal. Figure 8 As shown in the crystal phase diagram, due to the stable pressure provided by the screw 22 extrusion and the combination of the nozzle compaction structure, the porosity inside the printed component of the present invention is significantly reduced, forming a denser internal structure, thereby improving the overall mechanical properties. The process of setting the printing path includes: generating printing path data using offline programming software and converting the printing path data into a robot control program to synchronize the extrusion process with the robot's movement. Specifically, firstly, a printing model is created using 3D modeling software. Based on experimental requirements, tensile specimens, bending specimens, and honeycomb structure models are 3D modeled and exported as STL format files. Then, slicing software is used to slice the model. The slicing software decomposes the 3D model into layer-by-layer printing paths according to set printing parameters (such as layer height, runner width, and printing speed), generating a standard G-code file. This file contains key parameters such as printing path coordinates, extrusion control information, and printing speed. Since industrial robots cannot directly recognize G-code instructions, the G-code needs to be converted using a post-processing program in RoboDK software. RoboDK can convert the path information generated by slicing into a robot-executable motion program, thereby achieving robot path planning. After completing the robot program conversion, the program is imported into RobotStudio software for offline simulation. Simulation verifies the rationality of the robot's motion trajectory and checks the robot's workspace, motion posture, and path continuity, thus avoiding collisions or motion anomalies during actual printing.

[0036] The additive manufacturing system and method for continuous fiber reinforced composite material sensors proposed in this embodiment have the following advantages: (1) In terms of functional implementation, the present invention provides an axial discharge hole 411 and a lateral wire passage hole 412 in the nozzle body and connects the two inside the nozzle, so that the molten thermoplastic material and the continuous fiber can be compounded in the same extrusion channel, thereby realizing the integration of granular material extrusion and continuous fiber reinforced printing; compared with the existing method that requires replacement of printhead or multi-module collaboration, the present invention has a more compact structure, higher system integration, and can significantly simplify the equipment structure and reduce the switching complexity; (2) In terms of structural design, the present invention sets up a spatial coupling structure between the inclined through hole 412 and the axial discharge hole 411, so that the continuous fiber can form a stable confluence path with the molten material after entering the nozzle; this structure avoids the problems of fiber displacement and uneven coating that exist in traditional single-channel or external composite methods, and ensures the effective combination of fiber and matrix material from the structure, thereby improving the composite uniformity. (3) In terms of mechanical properties, since the continuous fiber is synchronously compounded with the molten material inside the nozzle and is laid out in a pre-set path under the control of the robot, the fiber can be distributed along the main force direction, thereby improving the tensile strength and stiffness of the printed component; at the same time, the relatively stable melt flow state and reasonable deposition process help to enhance the interlayer fusion bonding, reduce porosity, and thus improve the overall mechanical properties and anisotropy of the component. (4) In terms of process stability, the present invention constrains and guides the continuous fibers by setting the guide core and guide groove structure in the material guiding mechanism, so as to avoid them from entanglement or deviation during the conveying process, thereby reducing the occurrence of material blockage. (5) In terms of automation and control, the present invention integrates the screw extrusion system into the end of the industrial robot and realizes the synchronous control of the extrusion process and the robot motion through offline programming and path planning. Compared with traditional three-axis printing equipment, the robot's multi-degree-of-freedom motion capability makes the printing path more flexible, enabling the manufacturing of complex spatial structures and supporting the directional laying of continuous fibers in different directions, thereby improving the freedom of structural design. (6) In terms of system adaptability, the present invention sets a standardized connector structure at the nozzle end, so that the final forming nozzle can use conventional 3D printing nozzles and can be replaced with different aperture specifications as needed. This design allows the system to be flexibly adjusted between different printing accuracy and efficiency requirements, while reducing the cost of using special nozzles and improving the system's versatility and maintenance convenience; In summary, this invention, through structural innovation and process synergy, achieves comprehensive improvements in the functional integration, printing stability, mechanical properties, and application adaptability of the continuous fiber-reinforced screw extrusion additive manufacturing system, and has promising prospects for engineering applications.

[0037] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An additive manufacturing system for a continuous fiber reinforced composite material sensor, characterized in that, It includes a frame, screw feeding assembly, heating assembly, nozzle assembly, material guiding mechanism, and robot unit, wherein: The frame is connected to the robot unit; The screw feeding assembly is mounted on the frame and is used to supply granular material to the heating assembly; The heating component is mounted on the frame and located below the screw feeding component. It is used to heat and melt the conveyed granular material and supply it to the nozzle component. The nozzle assembly includes at least a nozzle body connected to the heating assembly. The nozzle body has an axially extending discharge hole and an inclined through-wire hole. The axial discharge hole is coaxially arranged with the heating assembly to achieve stable extrusion of molten granules. The through-wire hole is connected to the axial discharge hole to introduce composite filaments. The composite filaments are pre-compositely formed by continuous reinforcing fibers and materials with sensing functions, so that the composite filaments merge with the molten granules inside the nozzle body, forming a coating structure under the action of the molten material, and are extruded and deposited through the axial discharge hole to form a composite material component with an embedded sensor. The material guiding mechanism is connected to the through-hole and is used to constrain and guide the continuous fibers; The robot unit is used to drive the frame to achieve spatial movement of the printing path.

2. The additive manufacturing system for a continuous fiber reinforced composite material sensor as described in claim 1, characterized in that, The material guiding mechanism includes a feed tube and a guide core. The feed tube is connected to the through wire hole. The guide core is slidably disposed coaxially inside the feed tube. The outer wall of the guide core is provided with a guide groove along the axial direction.

3. The additive manufacturing system for a continuous fiber reinforced composite material sensor as described in claim 2, characterized in that, The feed end of the feed tube is provided with a positioning plate, and the positioning plate is provided with a positioning hole coaxial with the feed tube. The end of the guide core away from the through hole is provided with a lifting rod, and the lifting rod is slidably installed in the positioning hole.

4. The additive manufacturing system for a continuous fiber reinforced composite material sensor as described in claim 3, characterized in that, The guide groove is conical, and the diameter of the end of the guide groove near the through hole is larger than the diameter of the end of the guide groove away from the through hole.

5. The additive manufacturing system for a continuous fiber reinforced composite material sensor as described in claim 1, characterized in that, The screw feeding assembly includes a drive motor and a screw. The drive motor is mounted on the frame and is driven by the screw.

6. The additive manufacturing system for a continuous fiber reinforced composite material sensor as described in claim 1, characterized in that, The nozzle assembly also includes a connector that is detachably connected to the nozzle body and is used to connect an external forming nozzle.

7. The additive manufacturing system for a continuous fiber reinforced composite material sensor as described in claim 1, characterized in that, The angle between the axis of the through hole and the axis of the axial discharge hole is 30°~60°.

8. The additive manufacturing system for a continuous fiber reinforced composite material sensor as described in claim 1, characterized in that, It also includes a storage bin, which is installed above the heating assembly and is used to store granular material, with the screw feeding assembly extending into the storage bin.

9. An additive manufacturing method for a continuous fiber reinforced composite material sensor, using the additive manufacturing system for a continuous fiber reinforced composite material sensor as described in any one of claims 1-8, characterized in that, include: The screw feeding assembly supplies granular material to the heating assembly, which heats and melts the supplied granular material and then supplies it to the nozzle assembly. The continuous fibers are guided to the through-hole by the feeding mechanism; Stable extrusion of molten granules is achieved through the axial discharge hole. Composite filaments are introduced through the through hole, so that the composite filaments merge with the molten granules inside the nozzle body. Under the action of the molten material, a coating structure is formed, and the composite material component with an embedded sensor is formed by extrusion and deposition through the axial discharge hole. By setting printing parameters and printing path, the robot unit drives the frame and nozzle assembly to achieve spatial movement of the printing path, thus obtaining the printed part.

10. The additive manufacturing method for a continuous fiber reinforced composite material sensor as described in claim 9, characterized in that, The setting of printing parameters includes: setting the layer height to 0.2~0.4mm, the path overlap rate to 0~40%, and the printing speed to 15~60mm / s; Setting the printing path includes: generating printing path data using offline programming software and converting the printing path data into a robot control program to synchronize the extrusion process with the robot's movement.

Images