A fiber braiding device and a device for on-line braiding and printing continuous fibers

Abstract

The present invention discloses a fiber braiding device and a device for on-line braiding and printing continuous fibers, belonging to the technical field of three-dimensional printing. It includes a continuous fiber pay-off device and a polymer fiber braiding assembly. The continuous fiber pay-off device includes a first pay-off spool around which the continuous fiber is wound and a first tension control device for controlling the tension of the continuous fiber. The polymer fiber braiding assembly includes a hollow mandrel and at least two polymer fiber pay-off devices arranged around the outer circle of the hollow mandrel. The continuous fiber after passing around the first tension control device passes through the hollow mandrel and is fixed together with the polymer fiber in a winding mechanism to form a hybrid yarn with the continuous fiber as the core layer and the polymer fiber as the surface layer, improving the mechanical properties of the printed part. In addition, the first tension control device regulates the tension of the continuous fiber, which can avoid problems such as breakage, entanglement or uneven accumulation of the continuous fiber during the braiding process, further improving the mechanical properties of the printed part.

Description

Technical Field

[0001] The present invention relates to the field of three-dimensional printing technology, and particularly to a fiber braiding device and a device for online braiding and printing continuous fibers. Background Art

[0002] The development of three-dimensional printing technology has brought great innovation to the manufacturing industry. The Fused Deposition Modeling (FDM) technology is widely used in the fields of manufacturing, medical treatment, aerospace, etc. due to its low cost, material diversity, and easy operation. However, the printing materials of traditional FDM are mainly thermoplastic polymers, and their mechanical properties and functional characteristics are limited, making it difficult to meet the requirements for high-strength, high-modulus, and multi-functional components.

[0003] To improve the mechanical properties of printed parts, researchers have tried to add reinforcing materials such as short fibers and nanoparticles to the polymer matrix, but the reinforcing effect is limited. Introducing continuous fibers into FDM printing can significantly improve the strength and modulus of printed parts, and is considered an effective way to enhance the performance of three-dimensional printed parts. However, continuous fibers are easily affected by tension changes and friction during the supply process, making it difficult to maintain a stable supply speed and accurate position, resulting in problems such as fiber breakage, entanglement, or uneven accumulation during the printing process. Summary of the Invention

[0004] The purpose of the present invention is to provide a fiber braiding device and a device for online braiding and printing continuous fibers to address the defects and deficiencies in the prior art. By using continuous fibers as the core layer and polymer fibers as the surface layer, a hybrid yarn containing continuous fibers can be braided, improving the mechanical properties of the printed parts. Moreover, a first tension control device for controlling the tension of continuous fibers is provided in the fiber braiding device, which can avoid problems such as continuous fiber breakage, entanglement, or uneven accumulation during the braiding process, further improving the mechanical properties of the printed parts.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is:

[0006] The present invention provides a fiber braiding device, which includes a continuous fiber unwinding device and a polymer fiber braiding assembly. The continuous fiber unwinding device includes a first unwinding wheel disc wound with continuous fibers and a first tension control device. The first tension control device is arranged at the outlet end of the first unwinding wheel disc, and the continuous fibers released from the first unwinding wheel disc bypass the first tension control device;

[0007] The polymer fiber braiding assembly includes a hollow mandrel and at least four polymer fiber unwinding devices arranged around an outer ring of the hollow mandrel. The polymer fiber unwinding devices include second unwinding spools around which polymer fibers are wound. The continuous fiber after passing around the first tension control device passes through the hollow mandrel, and is fixed together with the polymer fiber released from the second unwinding spool at one end of the hollow mandrel away from the second unwinding spool in a winding mechanism, forming a hybrid yarn with the continuous fiber as the core layer and the polymer fiber as the surface layer. The polymer fiber unwinding devices are in transmission connection with a power component, and the polymer fibers not entering the winding mechanism move along a set trajectory and are distributed outside the hollow mandrel to form a tubular structure.

[0008] Preferably, the first tension control device includes a tension controller and a tension sensor. The tension controller is installed on a rotating shaft of the first unwinding spool, and a wire unwinding loop is provided on the tension controller. The released continuous fiber passes through the wire unwinding loop and then bypasses the tension sensor.

[0009] Preferably, the continuous fiber unwinding device further includes a switching and knotting device, and the continuous fiber unwinding device has at least two of the first unwinding spools;

[0010] The switching and knotting device includes a feeding roller, a fiber guide, a continuous fiber cutting assembly, and a splicer. One end of the fiber guide is provided with a plurality of fiber inlets not less than the number of the first unwinding spools, and the other end of the fiber guide is provided with a fiber outlet communicating with all the fiber inlets. A feeding roller is provided at each fiber inlet to feed the continuous fiber into or out of the fiber guide;

[0011] The continuous fiber cutting assembly includes a first cutter and a first driving assembly for driving the first cutter to move. The first cutter is placed at the fiber outlet for cutting the continuous fiber to be replaced in the fiber guide;

[0012] The splicer is placed on a side of the continuous fiber cutting assembly away from the fiber guide to wind and knot the newly replaced continuous fiber and the previous continuous fiber with each other to form a continuous continuous fiber.

[0013] Preferably, the polymer fiber unwinding device further includes a spinning spindle. The second unwinding spool is installed on the spinning spindle, and the spinning spindle is in transmission connection with the power component;

[0014] A second tension control device is provided on the spinning spindle. The second tension control device includes a fixed pulley, a movable pulley, the second wire unwinding wheel disc and a ratchet mechanism. The ratchet mechanism includes ratchet teeth, a ratchet pawl and a ratchet link provided on the side of the second wire unwinding wheel disc. The ratchet pawl and the ratchet link are hinged, and a torsion spring is provided at the hinge point. One end of the ratchet pawl away from the hinge point is clamped between adjacent ratchet teeth. One end of the ratchet link away from the hinge point is connected to the movable pulley. The fixed pulley is fixed on the spinning spindle. The polymer fiber sequentially passes around the fixed pulley and the movable pulley and then is fixed together with the continuous fiber in the winding mechanism.

[0015] Preferably, the fiber braiding device includes at least two polymer fiber braiding components arranged in series. The continuous fiber unwinding device is located at one end of the polymer fiber braiding components arranged in series and / or between adjacent polymer fiber braiding components. The hybrid yarn braided by the previous polymer fiber braiding component passes through the hollow core shaft as the core layer of the next polymer fiber braiding component to braid a multi-layer hybrid yarn or a multi-core layer hybrid yarn.

[0016] The present invention also provides a device for online braiding and printing continuous fibers, including the fiber braiding device and an FDM printing nozzle. The hybrid yarn braided by the fiber braiding device is supplied to the FDM printing nozzle, and the FDM printing nozzle prints the required product according to a set track.

[0017] Preferably, it further includes a tensioning device, a hybrid yarn skin treatment device, a real-time monitoring system and a central control unit. The tensioning device, the hybrid yarn skin treatment device and the real-time monitoring system are all located between the fiber braiding device and the FDM printing nozzle.

[0018] Preferably, the hybrid yarn skin treatment device is a heat treatment device or an adhesive device that makes the polymer fibers forming the hybrid yarn adhere to each other to form an integral structure that is not easily loosened and deformed.

[0019] Preferably, the real-time monitoring system includes a camera and a diameter measuring instrument. The hybrid yarn with the treated skin sequentially passes through the positions where the camera and the diameter measuring instrument are located, and the camera, the diameter measuring instrument, the tension sensor, the tension controller, the power component, and the first driving component are respectively connected to the central control unit in a signal connection.

[0020] Preferably, the FDM printing nozzle includes at least two feeding ports, one discharging port and a hot knife device. The discharging port is communicated with all the feeding ports. There are at least two groups of fiber braiding devices arranged in parallel. The hybrid yarn braided by each group of fiber braiding devices corresponds to one feeding port. A feeding roller is arranged at each feeding port for feeding or withdrawing the hybrid yarn into or from the feeding port.

[0021] The hot knife device includes a hot cutting knife and a second driving component for driving the hot cutting knife to move. The second driving component is signal-connected to the central control unit. The hot cutting knife is placed at the discharging port for cutting the previous hybrid yarn that has completed printing.

[0022] The present invention has achieved the following beneficial effects compared with the prior art:

[0023] 1. By setting the fiber braiding device to include a continuous fiber unwinding device and a polymer fiber braiding component, the polymer fiber braiding component includes a hollow core shaft and a polymer fiber unwinding device arranged around the outer circumference of the hollow core shaft, and the continuous fiber passes through the hollow core shaft and is fixed together with the polymer fiber in the winding mechanism, the continuous fiber is used as the core layer and the polymer fiber is used as the surface layer to braid the hybrid yarn containing continuous fiber, which improves the mechanical properties of the printed part.

[0024] In addition, the continuous fiber unwinding device includes a first tension control device. Under the action of the first tension control device, the tension of the continuous fiber is maintained in a suitable stable state, avoiding problems such as breakage, entanglement or uneven accumulation of the continuous fiber during the braiding process, realizing the stable supply of the continuous fiber, and further improving the mechanical properties of the printed part.

[0025] The other technical solutions of the present invention have achieved the following beneficial effects compared with the prior art:

[0026] 2. The continuous fiber unwinding device of the present invention also has a switching and knotting device, which can switch different types of continuous fibers online and braid various types of hybrid yarns to meet the performance requirements of various different printed products, broaden the scope of application, make the additive manufacturing method of high-performance continuous fiber composite materials more flexible, and play a greater role in the fields of aerospace, automotive, medical, etc.

[0027] 3. The fiber braiding device and the device for online braiding and printing continuous fibers of the present invention can braid multi-layer hybrid yarns and / or multi-core layer hybrid yarns online and print products containing multi-layer hybrid yarns and / or multi-core layer hybrid yarns, further broadening the scope of application;

[0028] In addition, the device for online braiding and printing continuous fibers can switch the hybrid yarn (i.e., printing consumables) for printing online, and can be applied to printing products that require two or more hybrid yarns, further broadening the application scope of the device and promoting the rapid development of the 3D printing industry;

[0029] Moreover, the online braiding and printing device can improve the compactness of the device and enhance the printing efficiency. It is a new type of 3D printing device that fills the gap in the existing technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0031] Figure 1 It is a schematic structural diagram of a fiber braiding device and a device for online braiding and printing continuous fibers (vertical) disclosed in a specific embodiment of the present invention;

[0032] Figure 2 It is a schematic structural diagram of a fiber braiding device and a device for online braiding and printing continuous fibers (horizontal) disclosed in a specific embodiment of the present invention;

[0033] Figure 3 It is a schematic structural diagram of a continuous fiber pay-off device disclosed in a specific embodiment of the present invention;

[0034] Figure 4 It is a schematic structural diagram of a fiber braiding device for braiding multi-layer hybrid yarns and a device for online braiding and printing continuous fibers (horizontal) disclosed in a specific embodiment of the present invention;

[0035] Figure 5 It is a schematic structural diagram of a fiber braiding device capable of switching printing consumables online and a device for online braiding and printing continuous fibers (horizontal) disclosed in a specific embodiment of the present invention;

[0036] Figure 6 It is a schematic structural diagram of an FDM printing nozzle disclosed in a specific embodiment of the present invention;

[0037] Figure 7 It is a schematic structural diagram of a polymer fiber pay-off device disclosed in a specific embodiment of the present invention;

[0038] Figure 8 It is a schematic structural diagram of another perspective of a second tension control device disclosed in a specific embodiment of the present invention.

[0039] Among them, 1. The first fiber pay-off reel; 2. The tension controller; 3. The tension sensor; 4. The fiber guide; 5. The splicer; 6. The polymer fiber pay-off device; 7. The hollow mandrel; 8. The central control unit; 9. The hybrid yarn skin treatment device; 10. The real-time monitoring system; 11. The FDM printing nozzle; 12. The tension pulley; 13. The continuous fiber cutting knife assembly; 14. The feeding roller; 15. The first cutting knife; 16. The first driving assembly; 17. The feeding port; 18. The discharging port; 19. The hot cutting knife; 20. The second driving assembly; 21. The extrusion gear; 22. The throat tube; 23. The heating block; 24. The spinning spindle; 25. The second fiber pay-off reel; 26. The movable pulley; 27. The fixed pulley; 28. The ratchet link; 29. The ratchet pawl; 30. The ratchet teeth; 31. The torsion spring; 32. The winding mechanism; 33. The inductive proximity sensor. Detailed implementation manners

[0040] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts shall fall within the protection scope of the present invention.

[0041] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below in conjunction with the drawings and specific implementation manners.

[0042] As Figure 1 , Figure 2 , Figure 4 , Figure 5 shown, the present invention provides a fiber braiding device, including a continuous fiber pay-off device and a polymer fiber braiding assembly. The continuous fiber pay-off device includes a first fiber pay-off reel 1 and a first tension control device. The continuous fiber to be used is wound on the first fiber pay-off reel 1. A first tension control device is provided at the outlet end of the first fiber pay-off reel 1, and the continuous fiber released from the first fiber pay-off reel 1 bypasses the first tension control device;

[0043] The polymer fiber braiding assembly includes a hollow mandrel 7 and at least four polymer fiber pay-off devices 6 arranged around the outer ring of the hollow mandrel 7. The polymer fiber pay-off device 6 includes a second pay-off wheel 25. The polymer fiber to be used is wound on the second pay-off wheel 25. The continuous fiber that bypasses the first tension control device passes through the cavity inside the hollow mandrel 7 and is fixed in the winding mechanism 32 together with the polymer fiber paid out from the second pay-off wheel 25 at the end of the hollow mandrel 7 away from the second pay-off wheel 25. The polymer fiber pay-off device 6 is connected to the power component in a transmission manner, so that the polymer yarns near the winding mechanism 32 are mutually wound to form a mixed yarn with the continuous fiber as the core layer and the polymer fiber as the surface layer. The polymer fibers away from the winding mechanism 32 are distributed on the surface of the hollow mandrel 7 to form a tubular structure. As the mixed yarn is consumed, the polymer fibers previously distributed on the surface of the hollow mandrel 7 move to the vicinity of the winding mechanism 32, and are wound around the outside of the continuous fibers to continue to form mixed yarns.

[0044] The first tension control device can adjust the tension of the continuous fiber to avoid the problem of continuous fiber breakage, entanglement or uneven stacking. As needed, the same type of polymer fiber can be wound on each second pay-off wheel 25, or different types of polymer fibers can be wound on different second pay-off wheels 25. Commonly used polymer fiber materials include but are not limited to polyamide (PA), polypropylene (PP), polyethylene (PE), polylactic acid (PLA), polycaprolactone (PCL), polyvinyl alcohol (PVA), polyetheretherketone (PEEK), polyimide (PI), polyphenylene sulfide (PPS), polycarbonate (PC), polyethylene terephthalate (PET), and polyvinyl chloride (PVC).

[0045] In an exemplary embodiment, the first tension control device includes a tension controller 2 and a tension sensor 3. The tension controller 2 is installed on the servo motor of the shaft core of the first pay-off wheel 1. The tension controller 2 is provided with a pay-off ring. The paid-off continuous fiber passes through the pay-off ring and then bypasses the tension sensor 3. When working, the tension sensor 3 monitors the tension of the continuous fiber in real time, and adjusts the rotation speed of the servo motor in real time according to the signal fed back by the tension sensor 3, thereby adjusting the pay-off speed of the continuous fiber and adjusting the tension to ensure the stability of the continuous fiber supply and the weaving quality.

[0046] like Figure 3As shown, the continuous fiber pay-off device further includes a switching and splicing device, and the continuous fiber pay-off device has at least two first pay-off spools 1; the switching and splicing device includes a feed roller 14, a fiber guide 4, a continuous fiber cutter assembly 13 and a splicer 5. One end of the fiber guide 4 is provided with a number of fiber inlets not less than that of the first pay-off spools 1, and the other end of the fiber guide 4 is provided with a fiber outlet communicating with all the fiber inlets. A feed roller 14 is provided at each fiber inlet to feed or withdraw different continuous fibers into or out of the fiber guide 4; the continuous fiber cutter assembly 13 includes a first cutter 15 and a first driving assembly 16 for driving the first cutter 15. The first cutter 15 is placed at the fiber outlet to cut the continuous fiber in the fiber guide 4 when the continuous fiber needs to be replaced; the splicer 5 is placed on the side of the continuous fiber cutter assembly 13 away from the fiber guide 4 to twist and knot the newly replaced continuous fiber and the previous continuous fiber to form a continuous continuous fiber. The first driving assembly 16 can be a gear-rack structure, a lead screw-nut structure, etc. In an exemplary embodiment, the first driving assembly 16 is a gear-rack structure, and a cutting edge is provided at the end of the rack to serve as the first cutter 15.

[0047] If it is necessary to replace the continuous fiber used as the core layer, first use the first cutter 15 to cut off the previous continuous fiber, then the feed roller 14 of the corresponding channel rotates reversely to withdraw the cut continuous fiber to the fiber inlet, and then the new continuous fiber is fed by the feed roller 14 of the corresponding channel, passes through the inside of the fiber guide 4 to the splicer 5, and the connection of the new and old continuous fibers is completed by twisting by the splicer 5. The splicer 5 can adopt the existing technology, and the structure of the splicer 5 is not improved in the present invention. In an exemplary embodiment of the present invention, the splicer 5 is an air splicer.

[0048] In an exemplary embodiment, four groups of first pay-off spools 1 are provided, and each first pay-off spool 1 is wound with a kind of continuous fiber. Each first pay-off spool 1 is correspondingly provided with a tension sensor 3, a tension controller 2 and a group of feed rollers 14. The corresponding fiber guide 4 has four fiber inlets. Figures 1 to 5 Only the tension sensor 3 and the feed roller 14 provided on one of the continuous fibers are shown as an example, and the tension sensors 3 and the feed rollers 14 on the remaining continuous fibers are omitted and not drawn. The continuous fiber can be carbon fiber, glass fiber, aramid fiber, basalt fiber, boron fiber, silicon carbide fiber, high molecular polyethylene fiber, polyester fiber, graphene fiber, carbon nanotube fiber, tungsten wire, copper wire, nitinol wire and other metal wires. Through the switching device, online switching of different types of continuous fibers can be realized. During the switching process, the twisting device is used to connect different fibers to ensure the continuity and stability of fiber supply. In addition, when braiding a hybrid yarn, one kind of continuous fiber can be used as the core layer, or two or more kinds of continuous fibers can be used as the core layer.

[0049] The polymer fiber pay-off device 6 further includes a spinning spindle 24, and a second pay-off wheel disc 25 is installed on the spinning spindle 24, and the spinning spindle 24 is in transmission connection with a power component; as Figure 7 , Figure 8 shown, for facilitating the control of the tension of the polymer fiber, a second tension control device is provided on the spinning spindle 24. The second tension control device includes a fixed pulley 27, a movable pulley 26, a second pay-off wheel disc 25 and a ratchet mechanism. The ratchet mechanism includes ratchet teeth 30, a ratchet pawl 29 and a ratchet link 28 arranged on the side surface of the second pay-off wheel disc 25. The ratchet pawl 29 and the ratchet link 28 are hinged, and a torsion spring 31 is provided at the hinge point. One end of the ratchet pawl 29 away from the hinge point is clamped between two adjacent ratchet teeth 30, and one end of the ratchet link 28 away from the hinge point is fixedly connected to the movable pulley 26. The fixed pulley 27 is fixed on the spinning spindle 24. The polymer fiber sequentially bypasses the fixed pulley 27 and the movable pulley 26 and is fixed together with the continuous fiber in a winding mechanism 32. During use, as the polymer fiber wound on the movable pulley 26 is pulled, the movable pulley 26 and the ratchet link 28 connected to the movable pulley 26 rotate together. When the tension is greater than the acting force of the torsion spring 31, the ratchet pawl 29 is lifted, and the second pay-off wheel disc 25 rotates and pays off the line, so that the tension of the polymer fiber is reduced. When the tension is less than the acting force of the torsion spring 31, under the action of the torsion spring 31, the ratchet pawl 29 is clamped into the adjacent ratchet teeth 30 again, pressing the second pay-off wheel disc 25 tightly. The above process can be continuously cycled to control the tension of the polymer fiber within a certain range. And the range of the tension can be jointly regulated by the number of turns of the fiber wound on the movable pulley 26 and the fixed pulley 27 and the stiffness of the torsion spring 31 on the rotating shaft of the ratchet link 28. The more the number of turns of winding, the smaller the wire tension, and the greater the stiffness of the torsion spring 31, the greater the wire tension. By controlling the magnitude of the tension of the polymer fiber, the compactness and uniformity of the braided tube structure can be ensured.

[0050] Among them, the movable pulley 26 and the fixed pulley 27 can guide the polymer fiber to be braided according to a set path and braiding angle. The braiding angle can be realized by adjusting the rotation speed of the braiding main shaft and the winding speed. Usually, the braiding angle is 30° - 85°. The braiding main shaft is driven by a high-precision servo motor to move the planetary gear set in the main shaft box. A spinning spindle 24 is installed on each planetary gear. The spinning spindle 24 follows the rotation and revolution of the planetary gear and moves along the track on the braiding main shaft box to form a specific braiding method, and the movement speed and braiding direction of the spinning spindle 24 are controlled by the servo motor. The braiding parameters, such as rotation speed, forward and reverse rotation, and winding pitch, are set through the central control unit.

[0051] In an exemplary embodiment, an inductive proximity sensor 33 is provided at a position close to the movable pulley 26. The inductive proximity sensor 33 can monitor the continuity of the polymer fiber in real time by sensing the position of the metal rotating shaft of the movable pulley 26.Figure 1 , Figure 4 , Figure 5 An inductive proximity sensor 33 is also provided at the corresponding position in [the device], not shown in the schematic diagram. The fiber braiding device of the present invention can be vertical, such as Figure 1 , or horizontal, such as Figure 2 .

[0052] As shown in Figure 4 , the fiber braiding device disclosed in the present invention can also braid multi-layer hybrid yarns and multi-core layer hybrid yarns. Specifically, at least two polymer fiber braiding components are serially arranged in the fiber braiding device. The continuous fiber unwinding device is located at one end of the serially arranged polymer fiber braiding components and / or between adjacent polymer fiber braiding components. The hybrid yarn braided by the previous polymer fiber braiding component passes through the hollow core shaft 7 as the core layer of the subsequent polymer fiber braiding component and is braided with the subsequent polymer fiber to form a multi-layer hybrid yarn.

[0053] In an exemplary embodiment, the continuous fiber unwinding device is located at one end of the serially arranged polymer fiber braiding components, and each section of the multi-layer hybrid yarn braided contains continuous fibers. In another exemplary embodiment, the continuous fiber unwinding device is located between a certain group of adjacent polymer fiber braiding components. At this time, the continuous fiber and the polymer fiber before the continuous fiber unwinding device are jointly braided to form another hybrid yarn (referred to as the second hybrid yarn for convenience of description). The continuous fiber in the second hybrid yarn does not serve as the core layer, but the second hybrid yarn will still serve as the core layer during subsequent braiding. In yet another exemplary embodiment, in addition to this, a continuous fiber unwinding device is provided at one end of the serially arranged polymer fiber braiding components to braid a hybrid yarn (referred to as the third hybrid yarn for convenience of description), and a continuous fiber unwinding device is also provided between a certain adjacent polymer fiber braiding components. The continuous fiber between the adjacent polymer fiber braiding components and the third hybrid yarn are used as the core layer during subsequent braiding.

[0054] As shown in Figure 1 , Figure 2 , Figure 4 , Figure 5 , the present invention also provides a device for online braiding and printing continuous fibers, including the above-mentioned fiber braiding device and an FDM printing nozzle 11. The hybrid yarn braided by the fiber braiding device is supplied to the FDM printing nozzle 11, and the FDM printing nozzle 11 moves according to the set motion trajectory to print the required product. Compared with the prior art method of pre-winding the printing consumables required for printing into a coil and then installing the coil on a 3D printing device for printing, the present invention can realize the online braiding, switching, and printing of continuous fibers, reducing the operation steps and improving the operation efficiency.

[0055] The device for online braiding and printing continuous fibers further includes a tension pulley 12, a hybrid yarn cortical treatment device 9, a real-time monitoring system 10, and a central control unit 8. The tension pulley 12, the hybrid yarn cortical treatment device 9, and the real-time monitoring system 10 are all located between the fiber braiding device and the FDM printing nozzle 11 to ensure the printing quality. The tension pulley 12 is set at a suitable position according to needs to ensure the stable supply of the hybrid yarn and the printing quality. The present invention does not make specific requirements on the number and position of the tension pulley 12.

[0056] The hybrid yarn cortical treatment device 9 is a heat treatment device or an adhesive device for making the polymer fibers constituting the hybrid yarn adhere to each other to form an integral structure that is not easily loosened or deformed. In an exemplary embodiment of the present invention, the hybrid yarn cortical treatment device 9 is a heat treatment device. The heat treatment device has a heat treatment die with an inner diameter slightly smaller than the outer diameter of the hybrid yarn. When the hybrid yarn passes through the heat treatment die, it is heated and extruded by the heat treatment die, and the uneven braided texture formed by the surface polymer fibers partially melts and adheres to form an integral structure that is not easily loosened or deformed. At the same time, the diameter of the hybrid yarn is controlled by the heat treatment die to adapt to the feed port of the FDM printing nozzle 11.

[0057] The real-time monitoring system 10 includes a camera and a diameter measuring instrument. The hybrid yarn with the treated cortex passes through the positions where the camera and the diameter measuring instrument are located in sequence. The fiber position and state in the braiding area are monitored in real time through the camera to detect whether there are problems such as fiber breakage, dislocation, or entanglement; the diameter of the treated hybrid yarn is measured through the diameter measuring instrument to ensure that the braided hybrid yarn meets the design requirements. The diameter measuring instrument can be a non-contact diameter measuring instrument, such as a laser diameter gauge, or a contact diameter measuring instrument. The camera, the diameter measuring instrument, the tension sensor 3, the tension controller 2, the power component, and the first driving assembly 16 are respectively connected to the central control unit 8 in a signal connection. The camera, the diameter measuring instrument, and the tension sensor 3 feedback the measured data to the central control unit 8 in real time. The central control unit 8 analyzes the acquired data to judge the states of fiber supply, braiding, and the quality of the hybrid yarn (i.e., the printing consumables), and thus sends instructions to the tension regulator, the power component, and the first driving assembly 16 to make corresponding actions; when an abnormal situation (such as fiber breakage, excessive tension, etc.) is detected, measures are automatically taken, such as suspending the equipment, adjusting parameters, or giving an alarm prompt. The central control unit 8 also has a human-machine interface for the operator to set parameters, monitor the equipment state, view real-time data and historical records, and perform manual control or intervention. When braiding multi-layer hybrid yarns, the central control unit 8 can coordinate the speeds, tensions, and fiber supplies of each continuous fiber unwinding device and / or the polymer fiber unwinding device 6 to ensure that the braiding of each layer is synchronized.

[0058] Among them, a three-dimensional model of the printed part is designed by computer-aided design (CAD) software, and a slicing software is used to generate the printing path and parameters, including layer thickness, filling rate, printing speed, etc.; the central control unit 8 sends the printing path and parameters to the motion control system to control the precise movement of the print head in the X, Y, and Z directions; according to the printing speed and path, the wire feeding amount of the wire feeding mechanism is adjusted in real time to ensure that the material supply matches the printing demand; by adjusting the printing path and the movement of the print head, the orientation design of the continuous fiber in the printed part is realized, such as arranging along the stress direction, to improve the mechanical properties of the printed part; the temperature of each heating zone of the print head is monitored in real time to ensure sufficient melting of the polymer and no thermal damage to the continuous fiber.

[0059] Such as Figure 5 , Figure 6 As shown in the figure, in an exemplary embodiment of the present invention, the FDM print head 11 includes at least two feed ports 17, one discharge port 18 and a hot knife device. The discharge port 18 is communicated with all the feed ports 17. There are at least two groups of fiber braiding devices on the printing device, and the hybrid yarns braided by each group of fiber braiding devices correspond to one feed port 17. A feed roller 14 is provided at each feed port 17 for feeding or withdrawing the hybrid yarn into or out of the feed port 17; the hot knife device includes a hot cutting knife 19 and a second driving component 20 for driving the hot cutting knife 19 to move linearly. The second driving component 20 is signal-connected to the central control unit 8. The hot cutting knife 19 is placed at the discharge port 18 and is perpendicular to the hybrid yarn for cutting the previous hybrid yarn that has completed printing.

[0060] When it is necessary to replace the printing consumables (i.e., the hybrid yarn), the central control unit 8 sends an instruction to the second driving component 20 to drive the hot cutting knife 19 to move to cut the previous hybrid yarn, and then the corresponding feed roller 14 rotates reversely to withdraw the previous hybrid yarn, and the feed roller 14 on the other hybrid yarn to be used rotates forward to feed it into the corresponding feed port 17, so that the FDM print head 11 continues to print using another hybrid yarn. The hot cutting knife 19 is a blade formed by winding an electric heating wire on the blade. When the hot cutting knife 19 cuts the hybrid fiber, it can melt the polymer material at the cross-section to bond the reinforcing fiber in the core layer with the skin layer, preventing axial misalignment of the core layer and skin layer materials and the generation of burrs on the skin layer material, thereby ensuring smooth wire feeding and printing accuracy for the next use. The remaining structures of the FDM print head 11, such as the extrusion gear 21, the throat tube 22, the heating block 23, etc., are the same as those in the prior art and are not changed.

[0061] Working process of the device for online braiding and printing continuous fibers:

[0062] 1. Initialization settings: The operator sets the parameters of the printed part, the selected material, the printing path, etc. through the human-machine interface.

[0063] 2. Consumable Preparation and Supply: The fiber braiding device starts to braid the consumable online, and the continuous fiber supply system supplies specific fibers according to the demand.

[0064] 3. Real-time Monitoring and Adjustment: The tension control system and the real-time monitoring system 10 monitor the states of the fibers and the consumable, and the central control unit 8 makes corresponding adjustments.

[0065] 4. Printing Process: The improved FDM printing nozzle 11 receives the consumable and prints according to the set path and parameters.

[0066] 5. Consumable Switching or Fiber Switching: According to the printing requirements, the central control unit 8 instructs the driving hot knife device and the feeding roller 14 to perform online switching of the consumable or the fiber.

[0067] 6. Printing Completion: After the printed part is completed, the device automatically stops, and the operator can perform post-processing or take out the printed part.

[0068] It should be noted that for those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention, and any reference signs in the claims should not be regarded as limiting the claims involved.

Claims

1. A fiber weaving device, characterized in that: The invention comprises a continuous fiber pay-off device and a polymer fiber braiding assembly, wherein the continuous fiber pay-off device comprises a first pay-off wheel on which continuous fibers are wound and a first tension control device, wherein the first tension control device is arranged at the outlet end of the first pay-off wheel, and the continuous fibers paid out from the first pay-off wheel bypass the first tension control device; The polymer fiber braiding assembly includes a hollow core shaft and at least four polymer fiber pay-off devices arranged around the outer ring of the hollow core shaft, the polymer fiber pay-off device includes a second pay-off wheel disk on which polymer fibers are wound, the continuous fibers that bypass the first tension control device pass through the hollow core shaft, and are fixed together with the polymer fibers paid out from the second pay-off wheel disk in a winding mechanism at one end of the hollow core shaft away from the second pay-off wheel disk, forming a mixed yarn with continuous fibers as a core layer and polymer fibers as a surface layer; the polymer fiber pay-off device is transmission-connected to a power component, and the polymer fibers that have not entered the winding mechanism move according to a set trajectory and are distributed outside the hollow core shaft to form a tubular structure; The polymer fiber pay-off device further comprises a spinning spindle, the second pay-off wheel is mounted on the spinning spindle, and the spinning spindle is transmission-connected to the power component; The spinning spindle is provided with a second tension control device, which includes a fixed pulley, a movable pulley, the second pay-off wheel and a ratchet mechanism, the ratchet mechanism includes a ratchet, a pawl and a ratchet connecting rod arranged on the side of the second pay-off wheel, the pawl and the ratchet connecting rod are hinged, and a torsion spring is provided at the hinge point, the end of the pawl away from the hinge point is clamped between adjacent ratchets, the end of the ratchet connecting rod away from the hinge point is connected to the movable pulley, the fixed pulley is fixed on the spinning spindle, and the polymer fiber is fixed in the winding mechanism together with the continuous fiber after passing through the fixed pulley and the movable pulley in turn.

2. The fiber braiding device according to claim 1, characterized in that: The first tension control device includes a tension controller and a tension sensor. The tension controller is installed on the rotating shaft of the first pay-off wheel. A pay-off ring is provided on the tension controller. The paid-off continuous fiber passes through the pay-off ring and then bypasses the tension sensor.

3. The fiber braiding device according to claim 2, characterized in that: The continuous fiber pay-off device further comprises a switching and twisting device, and the continuous fiber pay-off device has at least two of the first pay-off wheels; The switching and twisting device comprises a feeding roller, a fiber guide, a continuous fiber cutter assembly and a splicer, one end of the fiber guide is provided with a fiber inlet whose number is not less than that of the first pay-off wheel, the other end of the fiber guide is provided with a fiber outlet connected with all the fiber inlets, and each fiber inlet is provided with the feeding roller to feed the continuous fiber into or out of the fiber guide; The continuous fiber cutter assembly comprises a first cutter and a first driving assembly for driving the first cutter to move, wherein the first cutter is disposed at the fiber outlet and is used for cutting the continuous fiber to be replaced in the fiber guide; The splicer is disposed on a side of the continuous fiber cutter assembly away from the fiber guide to entangle and twist the newly replaced continuous fibers with the previous continuous fibers to form continuous fibers in a continuous state.

4. The fiber braiding device according to claim 3, characterized in that: The fiber weaving device includes at least two polymer fiber weaving components arranged in series, the continuous fiber pay-off device is located at one end of the polymer fiber weaving components arranged in series, and / or the continuous fiber pay-off device is located between adjacent polymer fiber weaving components, and the hybrid yarn woven by the previous polymer fiber weaving component passes through the hollow core shaft as the core layer of the next polymer fiber weaving component to weave into multi-layer hybrid yarn or multi-core layer hybrid yarn.

5. A device for online weaving and printing continuous fibers, characterized in that: It comprises the fiber weaving device and FDM printing head as described in any one of claims 3 to 4, wherein the mixed yarn woven by the fiber weaving device is supplied to the FDM printing head, and the FDM printing head prints the required product according to the set trajectory.

6. The device for online weaving and printing continuous fibers according to claim 5, characterized in that: It also includes a tensioning device, a hybrid yarn skin processing device, a real-time monitoring system and a central control unit. The tensioning device, the hybrid yarn skin processing device and the real-time monitoring system are all located between the fiber weaving device and the FDM printing nozzle.

7. The device for online weaving and printing continuous fibers according to claim 6, characterized in that: The hybrid yarn skin layer processing device is a heat treatment device or bonding device that allows the polymer fibers constituting the hybrid yarn to adhere to each other to form an integral structure that is not easily loosened or deformed.

8. The device for online weaving and printing continuous fibers according to claim 6, characterized in that: The real-time monitoring system includes a camera and a diameter measuring instrument. The mixed yarn with treated cortex passes through the positions of the camera and the diameter measuring instrument in sequence, and the camera, the diameter measuring instrument, the tension sensor, the tension controller, the power component, and the first drive assembly are respectively connected to the central control unit by signal.

9. The device for online weaving and printing continuous fibers according to any one of claims 6 to 8, characterized in that: The FDM printing nozzle comprises at least two feed ports, one discharge port and a hot knife device, the discharge port is connected to all the feed ports, at least two groups of fiber weaving devices are arranged in parallel, the mixed yarns woven by each group of fiber weaving devices correspond to one feed port, and each feed port is provided with a feeding roller for feeding the mixed yarn into or out of the feed port; The hot knife device includes a hot cutter and a second driving component for driving the hot cutter to move, the second driving component is connected to the central control unit by signal, and the hot cutter is placed at the discharge port to cut off the first mixed yarn that has been printed.

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