3D printing composite nozzle mechanism and 3D printing device

Abstract

The application discloses a 3D printing composite nozzle mechanism and 3D printing equipment, comprising: a connecting table; a mounting frame mounted at the lower end of the connecting table; two extrusion mechanisms with extrusion heads slidingly mounted on the mounting frame in the horizontal direction to adjust the distance between the two extrusion heads; a center filler mechanism with a filler output head, the output end of the filler output head opening downward and located between the two extrusion heads to output filler material between the materials extruded by the two extrusion heads. The filler output head of the application synchronously outputs filler material between the materials extruded by the two extrusion heads, realizing the integrated synchronous printing of the two substrate layers and the middle filler layer, without the need for single nozzle step-by-step operation. At the same time, the filler material is directly filled between the just-extruded substrate layers, avoiding the problem of poor bonding between materials caused by filling after the substrate layer solidifies, and improving the connection stability and overall mechanical properties of the composite sandwich structure.

Description

Technical Field

[0001] This invention relates to the field of 3D printing technology, and in particular, to a 3D printing composite nozzle mechanism and 3D printing equipment. Background Technology

[0002] With the iterative upgrades of additive manufacturing technology, 3D printing technology is being applied more and more deeply in fields such as building construction, industrial component molding, and composite material preparation, especially in the printing of composite sandwich structures, where it has greater advantages. Composite sandwich structures typically consist of two substrate layers on both sides and a middle filling layer, such as the main structural layer and insulation filling layer of concrete buildings, and the rigid panel layer + buffer filling layer of industrial plastic components.

[0003] Currently, existing 3D printing equipment for printing composite sandwich structures mostly adopts single-nozzle step-by-step printing or fixed-spacing multi-nozzle combination printing. When using single-nozzle printing, the substrate layers on both sides must be printed alternately first, and then the middle filling layer must be printed separately. The connection of multiple processes not only leads to extremely low printing efficiency, but also easily causes problems such as weak interlayer bonding and excessive gaps due to the solidification of the substrate layers, which reduces the overall mechanical properties of the composite sandwich structure. On the other hand, some printing equipment that uses multiple nozzles cannot adjust the horizontal spacing between the extrusion nozzles according to the actual printing needs, and can only adapt to the printing scenarios of a single sandwich width specification.

[0004] In actual production and construction, different application scenarios have significantly different requirements for the width of composite sandwich structures. Fixed-spacing composite printhead mechanisms cannot flexibly adapt to the printing needs of various sandwich specifications. If a dedicated printhead mechanism is designed for different specifications, it will increase the equipment procurement cost and the operation of replacing printheads will be cumbersome, which will seriously affect the efficiency of large-scale production and on-site construction. Summary of the Invention

[0005] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, the present invention proposes a 3D printing composite nozzle mechanism and a 3D printing device.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A 3D printing composite nozzle mechanism includes: a connecting platform; a mounting frame installed at the lower end of the connecting platform; two extrusion mechanisms, each including an extrusion head, which is slidably mounted on the mounting frame in a horizontal direction to adjust the distance between the two extrusion heads; and a central filling mechanism having a filling output head, the output end of which faces downward and is located between the two extrusion heads for outputting filling material to the middle of the material extruded by the two extrusion heads.

[0008] Furthermore, the mounting bracket is rotatably mounted on the lower end of the connecting platform around a vertical axis. A rotary drive mechanism is mounted on the connecting platform, and the rotary drive mechanism is connected to the mounting bracket in a transmission manner to drive the mounting bracket to rotate.

[0009] Furthermore, it also includes a slider and a sliding drive mechanism; the two sliders are slidably mounted on the mounting frame in a horizontal direction; two extrusion mechanisms are respectively connected to the two sliders so as to move synchronously with the sliders; the sliding drive mechanism is used to drive the sliders to slide to adjust the distance between the two sliders.

[0010] Furthermore, the sliding drive mechanism includes a rotary motor and a lead screw; the lead screw has a first threaded section and a second threaded section; the first threaded section and the second threaded section have opposite threading directions; both sliding parts are equipped with nut sleeves, and the nut sleeves on the two sliding parts respectively cooperate with the first threaded section and the second threaded section.

[0011] Furthermore, the extrusion mechanism includes an extrusion container and an extrusion drive mechanism. The extrusion container has a feed inlet and a discharge outlet. A transition member is installed between the extrusion head and the discharge outlet of the extrusion container. One end of the transition member is detachably connected to the end of the extrusion container, and the other end is detachably connected to the extrusion head. The transition member gradually converges toward the extrusion head. The extrusion drive mechanism is connected to the extrusion container and is used to drive the material in the extrusion container to flow toward the extrusion head and be output.

[0012] Furthermore, a telescopic stop is provided between the two extrusion heads, and the two ends of the telescopic stop are respectively connected to the two extrusion heads, so that the end of the telescopic stop can move with the corresponding extrusion head and drive the telescopic stop to extend and retract along the sliding direction of the extrusion head.

[0013] Furthermore, the filler output head can move horizontally relative to the mounting frame, and the two extrusion heads slide along the same horizontal straight line. The direction of movement of the filler output head is parallel to the sliding direction of the extrusion mechanism; the opening direction of the filler output head and the extrusion head is downward.

[0014] Furthermore, the central packing mechanism includes a feed pump and a packing head movable drive mechanism. The feed pump has an output pipe, and one end of the packing output head is movably sleeved on the output pipe so that it can move horizontally along the output pipe. The packing head movable drive mechanism is mounted on the mounting frame and connected to the packing output head for driving the packing output head to move horizontally.

[0015] Furthermore, the packing head movable drive mechanism has a telescopic rod that can extend and retract, an adapter is connected to the telescopic rod, and a pipe clamp assembly is installed on the adapter. The pipe clamp assembly is used to clamp the packing output head.

[0016] The present invention also provides a 3D printing device, including the aforementioned 3D printing composite nozzle mechanism.

[0017] The present invention has the following beneficial effects:

[0018] The system features two extrusion mechanisms and a central filling mechanism. The two extrusion heads simultaneously extrude material from both sides of the substrate layer, while the filling output head simultaneously delivers filler material between the materials extruded by the two extrusion heads. This achieves integrated, synchronous printing of the substrate layers and the central filling layer, eliminating the need for separate printhead operations and solving the problem of low efficiency in traditional step-by-step printing. Simultaneously, the filler material directly fills the spaces between the freshly extruded substrate layers, avoiding the problem of weak adhesion caused by filling after the substrate layers have solidified. This improves the connection stability and overall mechanical properties of the composite sandwich structure. This three-head synchronous printing enhances printing efficiency and strengthens adhesion. The two extrusion mechanisms slide horizontally on the mounting frame, allowing for flexible adjustment of the horizontal distance between the two extrusion heads according to the actual sandwich width requirements of production and construction. This breaks the limitation of traditional fixed-spacing printheads that can only adapt to a single size of sandwich structure. It eliminates the need to design dedicated printhead mechanisms for different sandwich sizes, effectively reducing equipment procurement costs, saving the tedious operation of frequent printhead changes, improving the efficiency of large-scale production and on-site construction, and enhancing the versatility and adaptability of the printhead mechanism.

[0019] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0020] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0021] Figure 1 This is a schematic diagram of the working state structure of one embodiment of the present invention;

[0022] Figure 2 yes Figure 1 Enlarged view of point A;

[0023] Figure 3 This is a schematic diagram of the overall structure of one embodiment of the present invention;

[0024] Figure 4 yes Figure 3 A schematic diagram of a decomposed state structure;

[0025] Figure 5 This is a schematic diagram of the decomposed state structure of one embodiment of the present invention;

[0026] Figure 6 yes Figure 5 Enlarged view of point B;

[0027] Figure 7 This is a schematic diagram of the central packing mechanism;

[0028] Figure 8 This is a schematic diagram of the overall process of the three-nozzle 3D printing method;

[0029] Figure 9 This is a detailed flowchart of step S3;

[0030] Figure 10 This is a printed diagram of the bend.

[0031] Legend:

[0032] Connecting platform 100, rotary drive mechanism 110;

[0033] Mounting bracket 200;

[0034] Extrusion mechanism 300, extrusion head 310, second docking plate 311, extrusion container 320, feed port 321, transition piece 322, first docking plate 323, extrusion drive mechanism 330, clamp 340, first half-clamp ring 341, second half-clamp ring 342, groove 343, first connecting block 350, first notch 351, second connecting block 360, screw 370, locking nut 380;

[0035] The central packing mechanism 400, the packing output head 410, the feed pump 420, the output pipe 421, the packing head movable drive mechanism 430, the telescopic rod 431, the adapter 432, and the pipe clamp assembly 433 are all included.

[0036] Sliding component 500, nut sleeve 510;

[0037] Sliding drive mechanism 600, rotary motor 610, lead screw 620, first threaded section 621, second threaded section 622;

[0038] Telescopic stop 700. Detailed Implementation

[0039] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0040] 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 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.

[0041] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0042] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0043] Please refer to Figures 1 to 3 A preferred embodiment of the present invention provides a 3D printing composite nozzle mechanism, including a connecting platform 100, a mounting frame 200, an extrusion mechanism 300, and a central filler mechanism 400.

[0044] The connecting stage 100 is used to connect to the moving head of the 3D printing equipment to achieve mobile printing. For example, the 3D printing equipment is equipped with a moving head that can move along three axes: horizontal (x-axis), vertical (Y-axis), and longitudinal (Z-axis). The connecting stage 100 is connected to the moving head to achieve mobile printing. Of course, the moving head can also be driven by a robotic arm to achieve three-axis movement.

[0045] The mounting bracket 200 is installed on the connecting platform 100. In this embodiment, the mounting bracket 200 is installed at the lower end of the connecting platform 100.

[0046] There are two extrusion mechanisms 300, each including an extrusion head 310. The extrusion mechanism 300 is slidably mounted on the mounting frame 200 in the horizontal direction, thereby adjusting the distance between the two extrusion heads 310.

[0047] The central filling mechanism 400 has a filling output head 410, the output end of which faces downward and is located between two extrusion heads 310, for outputting filling material between the materials extruded by the two extrusion heads 310. This eliminates the need for multiple separate printing processes for the spacer layer and filling layer, improving the overall printing efficiency of the sandwich structure. The filling material directly fills the space between the two freshly extruded materials, achieving contact and fusion before the three materials have completely cooled and solidified after output. This enhances the bonding strength between the filling layer and the spacer layer, strengthening the overall stability and mechanical properties of the sandwich structure, and adapting to the printing needs of composite sandwich structures such as honeycomb sandwiches and insulation sandwiches.

[0048] This invention provides a 3D printing composite nozzle mechanism, comprising two extrusion mechanisms 300 and a central filling mechanism 400. The two extrusion heads 310 simultaneously extrude material from both sides of the substrate layer, and the filling output head 410 simultaneously outputs the filling material to the middle of the materials extruded by the two extrusion heads 310. This achieves integrated synchronous printing of the two side substrate layers and the middle filling layer, eliminating the need for separate steps with individual nozzles and solving the problem of low efficiency in traditional step-by-step printing. Simultaneously, the filling material directly fills the spaces between the freshly extruded substrate layers, avoiding the slow printing speed caused by step-by-step printing and the resulting complete cooling of the substrate before filling, which leads to poor bonding strength. It also avoids the problem of weak adhesion between materials caused by filling after the substrate layer has solidified, improving the bonding stability and overall mechanical properties of the composite sandwich structure. This three-head synchronous printing improves printing efficiency and enhances bonding strength. Two extrusion mechanisms 300 are horizontally slidably mounted on the mounting frame 200. The horizontal distance between the two extrusion heads 310 can be flexibly adjusted according to the actual core width requirements of production and construction. This breaks the limitation of traditional fixed-spacing nozzles that can only adapt to a single type of core structure. It eliminates the need to design dedicated nozzle mechanisms for different core specifications, effectively reducing equipment procurement costs, saving the tedious operation of frequent nozzle replacements, improving the efficiency of large-scale production and on-site construction, and enhancing the versatility and adaptability of the nozzle mechanism. The mounting frame 200 provides a stable mounting foundation for the extrusion mechanism 300 and the central filler mechanism 400. All components work together in a compact overall structure, flexibly adapting to the installation needs of 3D printing equipment in different fields such as building construction, industrial component molding, and composite material preparation, making it widely applicable.

[0049] Reference Figure 1In some embodiments of the present invention, the mounting frame 200 is rotatably mounted on the lower end of the connecting platform 100 about a vertical axis. A rotary drive mechanism 110 is mounted on the connecting platform 100, and the rotary drive mechanism 110 is connected to the mounting frame 200 to drive the mounting frame 200 to rotate. The rotary drive mechanism 110 drives the mounting frame 200 to rotate, which can drive the two extrusion mechanisms 300 and the central filler mechanism 400 to rotate synchronously, realizing flexible adjustment of the printing direction of the nozzle mechanism. It can complete the printing of composite sandwich structures at different angles without relying on the overall rotation of the moving head of the 3D printing equipment, adapting to the printing needs of non-linear sandwich structures such as irregular shapes and arcs, and improving the printing flexibility of the nozzle mechanism. Specifically, in this embodiment, a gear ring is rotatably mounted on the mounting bracket 200. The gear ring can rotate relative to the mounting bracket 200 along its own axis. The axial direction of the gear ring is limited by a corresponding structure (such as a retaining ring, bearing, etc.), so that it only has the degree of freedom to rotate along its own axis on the mounting bracket 200. The gear ring and the mounting bracket 200 are connected by fasteners so that the gear ring and the mounting bracket 200 can rotate synchronously. The rotation drive mechanism 110 consists of a motor and a reduction mechanism. The rotation shaft of the motor is connected to the reduction mechanism. The reduction mechanism has an output shaft. The rotation shaft drives the output shaft to rotate through the reduction mechanism. The output shaft is connected to a drive gear. The drive gear drives the gear ring to rotate, thereby driving the mounting bracket 200 to rotate. Understandably, to facilitate control of the printing path, especially at turning points, the midpoints of the two extrusion heads 310 are collinear with the rotation axis of the mounting frame 200. This means the cross-sectional profile of the extrusion head 310's output port has a center point, and the midpoint of the two extrusion heads 310 is the midpoint of the center points of their output ports. The filler output head 410 is typically located at the center of the two extrusion heads 310 or reciprocates at that center. When the filler output head 410 is typically located at the center of the two extrusion heads 310, the center point of its output port is collinear with the rotation axis of the mounting frame 200. Therefore, when turning, the rotation axis of the mounting frame 200 is used as a reference to move along the printing path. This ensures that, because the center point of the filler output head 410's output port is collinear with the rotation axis of the mounting frame 200, the output port of the filler output head 410 will not change its printing path due to the rotation of the mounting frame 200 during turns. When turning, the moving head of the 3D printing equipment drives the connecting stage 100 to move along the arc printing path.

[0050] Reference Figure 1 and Figure 2In some embodiments of the present invention, a sliding member 500 and a sliding drive mechanism 600 are also included. Two sliding members 500 are slidably mounted on the mounting frame 200 in a horizontal direction. Two extrusion mechanisms 300 are respectively connected to the two sliding members 500 so that they can move synchronously with the sliding members 500. The sliding drive mechanism 600 is used to drive the sliding members 500 to slide to adjust the distance between the two sliding members 500. By using the sliding member 500 as the connecting carrier between the extrusion mechanism 300 and the mounting frame 200, and cooperating with the sliding drive mechanism 600 to drive the sliding member 500 to slide, a stable transmission structure is provided for the horizontal movement of the extrusion mechanism 300. This avoids the need for the extrusion mechanism 300 to be designed with a complex structure for direct sliding cooperation with the mounting frame 200. The split structure facilitates processing, installation, and disassembly and maintenance. The sliding drive mechanism 600 can precisely control the sliding of the sliding member 500, realize quantitative adjustment of the distance between the two extrusion heads 310, and make the adjustment of the core width precise, adapting to the printing requirements of high-precision composite core structures. Moreover, the modular sliding structure design facilitates later maintenance and replacement, improving the durability of the printhead mechanism. Specifically, the extrusion container 320 is detachably connected to the sliding component 500, allowing for the assembly and disassembly of the extrusion mechanism 300 and the sliding component 500. When an extrusion mechanism 300 malfunctions, requires replacement with an extrusion container 320 of a different specification to adapt to different materials / discharge requirements, or needs cleaning and maintenance of the extrusion container 320, the entire sliding component 500 and other related parts do not need to be disassembled; the operation can be completed by disassembling and assembling the extrusion container 320 alone. This reduces the complexity of maintenance and replacement operations and improves the efficiency and flexibility of nozzle assembly maintenance. Specifically, the sliding component 500 has a connecting hole, and the periphery of the extrusion container 320 has a mounting base with mounting holes. The mounting holes are aligned with the connecting holes, and screws are installed for installation and fixation.

[0051] It is understood that, in specific embodiments of the present invention, the mounting bracket 200 is provided with a horizontally extending slide rail, and the slider 500 is equipped with a slider adapted to the slide rail. Through the sliding engagement of the slide rail and the slider, stable guidance and support are provided for the horizontal movement of the slider 500, effectively limiting the offset and swaying of the slider 500 during movement, ensuring that the slider 500 slides smoothly in the horizontal direction. Typically, to improve sliding stability, two slide rails are provided, thereby achieving multi-position sliding guidance and limiting.

[0052] Reference Figure 4In some embodiments of the present invention, the sliding drive mechanism 600 includes a rotary motor 610 and a lead screw 620; the lead screw 620 has a first threaded section 621 and a second threaded section 622; the threads of the first threaded section 621 and the second threaded section 622 have opposite directions of thread advance; both sliding members 500 are equipped with nut sleeves 510, and the nut sleeves 510 on the two sliding members 500 respectively cooperate with the first threaded section 621 and the second threaded section 622. When the lead screw 620 with the first threaded section 621 and the second threaded section 622 with opposite directions of thread advance cooperates with the nut sleeves 510, and the rotary motor 610 drives the lead screw 620 to rotate in one direction, the two sliding members 500 can move synchronously towards or away from each other along the lead screw 620, without the need to control the drive components of the two extrusion mechanisms 300 separately, simplifying the control logic of the nozzle mechanism and reducing the control cost and structural complexity of the equipment; it can be understood that the two extrusion mechanisms 300 are symmetrically arranged along a vertical axis, and the two extrusion heads 310 are respectively located at opposite ends of the two extrusion containers 320. The two extrusion mechanisms 300 are symmetrically arranged along a vertical axis, and the two extrusion heads 310 are located at opposite ends of the extrusion container 320. This symmetrical arrangement of the extrusion heads 310 at opposite ends minimizes the minimum spacing between them, preventing the length of the extrusion container 320 from affecting the spacing adjustment range. Simultaneously, the symmetrical layout ensures more even force distribution on the mounting bracket 200 as the two extrusion mechanisms 300 move with the sliding member 500, preventing equipment wobbling due to unilateral weight distribution and ensuring the overall operational stability of the printhead assembly. Furthermore, the synchronous symmetrical adjustment design keeps the center position of the two extrusion heads 310 constant, preventing the printed core structure from shifting due to spacing adjustments.

[0053] Reference Figure 5In a further embodiment of the present invention, the extrusion mechanism 300 includes an extrusion container 320 and an extrusion drive mechanism 330. The extrusion container 320 has a feed inlet 321 and a discharge outlet. A transition member 322 is installed between the extrusion head 310 and the discharge outlet of the extrusion container 320. One end of the transition member 322 is detachably connected to the end of the extrusion container 320, and the other end is detachably connected to the extrusion head 310. The transition member 322 gradually converges toward the extrusion head 310, that is, the transition member 322 has a gradual channel that gradually converges toward the extrusion head 310. The extrusion drive mechanism 330 is connected to the extrusion container 320 and is used to drive the material in the extrusion container 320 to flow toward the extrusion head 310 and be output. The extrusion mechanism 300 is equipped with an extrusion container 320 and an extrusion drive mechanism 330, which can realize the integration of material storage and quantitative delivery. The extrusion drive mechanism 330 provides stable power for material flow, ensuring the continuity and uniformity of the material output from the extrusion head 310, and adapting to the extrusion requirements of different viscous materials such as plastics and concrete. A transition piece 322 with a gradient channel is set between the extrusion head 310 and the extrusion container 320. The gradient channel gradually converges towards the extrusion head 310, which can guide and converge the material, avoid material accumulation and turbulence caused by abrupt changes in cross-section, and improve the uniformity of the output. At the same time, the transition piece 322 is detachably connected to the extrusion container 320 and the extrusion head 310. Different specifications of the transition piece 322 and the extrusion head 310 can be replaced according to printing requirements to adapt to different output specifications of printing needs. Moreover, the operation is convenient for cleaning and replacing parts later, improving the adaptability and maintenance efficiency of the printhead mechanism.

[0054] Specifically, the extrusion drive mechanism 330 includes a rotary drive assembly with a rotating shaft. The rotary drive assembly can be a rotary motor with a reduction gear. Helical blades are provided on the peripheral wall of the rotating shaft. The extrusion container 320 is cylindrical, with one end connected to the extrusion head 310 and the other end connected to the outer shell of the rotary drive assembly. The rotating shaft is arranged along the axial direction of the extrusion container 320 and extends into the extrusion container 320. The extrusion drive mechanism 330 uses a rotating shaft with helical blades in conjunction with a cylindrical extrusion container 320. When the rotary drive assembly drives the rotating shaft to rotate, the helical blades can generate a continuous and uniform pushing force on the material inside the extrusion container 320, achieving quantitative and stable material delivery towards the extrusion head 310. Furthermore, the rotating shaft is arranged along the axial direction of the extrusion container 320, and the pushing force is linearly transmitted along the material flow direction, adapting to the extrusion requirements of materials with different viscosities such as plastics and concrete. It especially ensures smooth output of high-viscosity materials such as concrete, improving the adaptability and stability of material extrusion.

[0055] Reference Figure 6In a specific embodiment of the present invention, the transition member 322 is provided with a first mating plate 323 at one end corresponding to the extrusion head 310; the extrusion head 310 is provided with a second mating plate 311 at one end corresponding to the transition member 322. The first mating plate 323 and the second mating plate 311 are fitted together and connected and fixed by a clamp 340. The transition member 322 and the extrusion head 310 are respectively provided with a first mating plate 323 and a second mating plate 311 that fit together, and are connected and fixed by a clamp 340, which increases the contact area between the two and effectively improves the sealing performance of the connection between the transition member 322 and the extrusion head 310, preventing material leakage from the mating gap and ensuring that all material is discharged from the extrusion head 310. At the same time, the connection method of the clamp 340 realizes the quick assembly and disassembly of the transition member 322 and the extrusion head 310, reduces the difficulty of replacing and cleaning parts, improves the maintenance and replacement efficiency of the nozzle assembly, and adapts to the rapid operation requirements in industrial production. It can be understood that, in order to further improve the sealing performance of the connection, a sealing ring can be provided between the first mating plate 323 and the second mating plate 311.

[0056] Reference Figure 6In a specific embodiment of the present invention, the clamp 340 includes a first half-clamp ring 341 and a second half-clamp ring 342. The inner rings of the first half-clamp ring 341 and the second half-clamp ring 342 are provided with grooves 343 for the first mating plate 323 and the second mating plate 311 to be inserted. One end of the first half-clamp ring 341 is hinged to one end of the second half-clamp ring 342. The other end of the first half-clamp ring 341 is provided with a first connecting block 350, and the other end of the second half-clamp ring 342 is provided with a second connecting block 360. The first connecting block 350 and the second connecting block 360 are connected by a connecting component to achieve the clamping and limiting of the first mating plate 323 and the second mating plate 311 by the first half-clamp ring 341 and the second half-clamp ring 342. The clamp 340 adopts an openable structure with the first half-clamp ring 341 and the second half-clamp ring 342 hinged together. The inner ring is provided with a groove 343 for the first docking plate 323 and the second docking plate 311 to be inserted. The groove 343 can limit the two docking plates and prevent the clamp 340 from moving axially after clamping, thus improving the connection stability between the clamp 340 and the docking plate. The hinged half-clamp ring design allows the clamp 340 to be opened and closed quickly. When putting on or taking off the clamp, there is no need to put it through the end of the docking plate. The initial positioning can be completed by directly snapping it on, which simplifies the assembly and disassembly of the clamp 340. At the same time, the clamping and limiting are achieved by the first connecting block 350, the second connecting block 360 and the connecting components, ensuring that the first docking plate 323 and the second docking plate 311 fit tightly together, improving the sealing performance at the joint between the transition part 322 and the extrusion head 310, effectively preventing material leakage from the gap, and taking into account both the ease of assembly and disassembly and the connection sealing and stability. It is understandable that the opposite sides of the first mating plate 323 and the second mating plate 311 are conical surfaces, and the conical surfaces arch towards the center, thus forming a shape that is thin at the outer periphery and gradually thickens towards the center. This facilitates insertion into the slot 343, and also makes the fit tighter as the insertion depth into the slot 343 increases, improving the tightness of the fit. This can convert the clamping force of the first half-ring 341 and the second half-ring 342 into the clamping force of the first mating plate 323 and the second mating plate 311. The first connecting block 350 has a first notch 351, and the second connecting block 360 has a second notch. A screw 370 is hinged to the first notch 351, and the screw 370 passes through the second notch and is connected to a locking nut 380 to clamp the first connecting block 350 and the second connecting block 360 close together. The threaded engagement between the screw 370 and the locking nut 380 enables clamping. The screw 370 is connected to the first connecting block 350 via a hinge shaft. The hinge shaft passes through the screw 370 and its two ends are inserted into the hinge holes on the two opposite side walls of the first notch 351. The screw 370 can swing flexibly at the hinge point. When disassembling, loosen the locking nut 380 and rotate the screw 370 until it is disengaged from the second notch. The opening and closing of the clamp 340 can be completed without completely disassembling the screw 370 and the locking nut 380, further improving the efficiency of disassembly and assembly.

[0057] Reference Figure 2In a further embodiment of the present invention, a telescopic stop 700 is provided between the two extrusion heads 310. Both ends of the telescopic stop 700 are connected to the two extrusion heads 310 respectively, so that the end of the telescopic stop 700 can extend and retract along the sliding direction of the extrusion head 310 as the corresponding extrusion head 310 moves. That is, the telescopic stop 700 can extend and retract with the relative movement of the two extrusion heads 310. The output end of the filler output head 410 passes through the telescopic stop 700 to avoid affecting the normal output of the filler. A telescopic stop 700 is provided between the two extrusion heads 310, and its two ends extend and retract synchronously with the relative movement of the extrusion heads 310. The telescopic stop 700 can shield the filling material between the two extrusion heads 310, preventing the filling material from laterally spilling due to its own fluidity, equipment movement, or material impact during printing, ensuring the regularity of the forming contour of the filling material and improving the forming accuracy of the composite sandwich structure. At the same time, the telescopic stop 700 can slightly limit the substrate layer extruded by the extrusion heads 310, reducing the deformation problem of the substrate layer after extrusion, allowing the substrate layers on both sides to adhere more tightly to the middle filling layer, and the telescopic structure is fully adaptable to the spacing adjustment of the extrusion heads 310, without affecting the adaptability of the printhead mechanism to different sandwich widths. Specifically, the telescopic stop 700 can be a folding telescopic structure or a sleeve telescopic structure, such as a folding baffle or a sleeve baffle.

[0058] Reference Figure 2In a further embodiment of the present invention, the filler output head 410 is horizontally movable relative to the mounting frame 200, and the direction of movement of the filler output head 410 is parallel to the sliding direction of the extrusion mechanism 300. By configuring the filler output head 410 to be horizontally movable relative to the mounting frame 200, and with its direction of movement parallel to the sliding direction, it can flexibly adjust its horizontal position according to the change in the distance between the two extrusion heads 310, avoiding filler position displacement due to the adjustment of the extrusion head 310 distance, and ensuring that the filler material is accurately filled to the middle of the substrate layers on both sides. The movable filler output head 410 can adapt to the filler requirements of different core widths, making the cooperation between the central filler mechanism 400 and the extrusion mechanism 300 more suitable, further improving the overall printing quality of the composite sandwich structure. The movable position of the filler output head 410 allows the filler output position to move back and forth between the two extrusion heads 310, thereby achieving back-and-forth material distribution and avoiding uneven filling caused by a large distance between the two extrusion heads 310; it can also achieve Z-shaped or S-shaped material distribution filling according to the process. The two extrusion heads 310 slide along the same horizontal straight line, ensuring that after position adjustment, they remain on the same straight line without any deviation in other directions. The openings of the filler output head 410 and the extrusion head 310 are set downwards. This adapts to the layer-by-layer stacking requirements of 3D printing, allowing the extruded material to stack on top of the material below, avoiding misalignment of printed layers caused by deviation in the material output direction. Simultaneously, it ensures that the material falls in the same direction when all three heads are extruding simultaneously, resulting in a tighter bond between the substrate layer and the filler layer, improving the interlayer bonding strength and overall structural stability of the composite sandwich structure.

[0059] Reference Figure 1 , Figure 5 In a further embodiment of the present invention, the central filling mechanism 400 includes a feed pump 420 and a filling head movable drive mechanism 430. The feed pump 420 has an output pipe 421, and one end of the filling output head 410 is movably sleeved on the output pipe 421 so as to be able to move horizontally along the output pipe 421. The filling head movable drive mechanism 430 is mounted on the mounting frame 200 and connected to the filling output head 410 for driving the filling output head 410 to move horizontally. The central filling mechanism 400 provides stable power for conveying filling material through the feed pump 420, ensuring the continuity and quantitativeity of filling material output. The filling output head 410 is movably sleeved on the output pipe 421, and during the movement, the connection and docking between the filling output head 410 and the output pipe 421 is not affected. The horizontal movement is driven by the filling head movable drive mechanism 430 on the mounting frame 200, realizing the automated movement of the filling output head 410.

[0060] Reference Figure 7In a further embodiment of the present invention, the packing head moving drive mechanism 430 has a telescopic rod 431 that can extend and retract. An adapter 432 is connected to the telescopic rod 431, and a pipe clamp assembly 433 is installed on the adapter 432. The pipe clamp assembly 433 is used to clamp the packing output head 410. The pipe clamp assembly 433 includes a lower clamping block and an upper clamping block. The opposing surfaces of the lower clamping block and the upper clamping block are provided with arc grooves for the packing output head 410 to be inserted and clamped by the lower clamping block and the upper clamping block. The lower clamping block and the upper clamping block are provided with corresponding holes for connection and fixation by fasteners, thereby clamping and fixing the packing output head 410, and driving the packing output head 410 to extend and retract with the telescopic rod 431. The filler head moving drive mechanism 430 drives the filler output head 410 to move horizontally through the extension and retraction of the telescopic rod 431, thereby adjusting the position of the filler. The telescopic rod 431 is connected to the filler output head 410 via an adapter 432 and a pipe clamp assembly 433. The pipe clamp assembly 433 allows for clamping and disassembling of the filler output head 410, facilitating the replacement of different specifications of the filler output head 410 according to printing requirements. Simultaneously, the adapter 432 can be adjusted at its installation angle as needed, thereby flexibly adjusting the installation angle of the pipe clamp assembly 433 to ensure that the discharge direction of the filler output head 410 is downward and consistent with the discharge direction of the extrusion head 310. Specifically, the adapter 432 and the end of the telescopic rod 431 have corresponding holes for connection and fixation with screws. During installation, the adapter 432 can be rotated relative to the telescopic rod 431 along the axis of the telescopic rod 431 to adjust to a suitable angle before being fixed with screws, thus achieving angle adjustment and fixation of the adapter 432.

[0061] This invention also provides a 3D printing device, including a 3D printing composite nozzle mechanism. This printing device possesses the core advantages of simultaneous three-head printing and flexible adjustment of the core width, directly adapting to the printing needs of composite sandwich structures in fields such as building construction, industrial component molding, and composite material preparation, thus improving the functional adaptability and application scope of the printing device.

[0062] Reference Figure 8 The following provides a three-nozzle 3D printing method for 3D printing composite nozzle mechanisms, including steps S1, S2 and S3.

[0063] S1. Obtain the digital model of the composite sandwich structure to be printed, and extract the printing path and sandwich width parameters from the model. The printing path uses the center point of the two extruder heads 310 as the path reference point. Based on the digital model, extract the core printing parameters to provide accurate digital basis for subsequent nozzle spacing adjustment, flow rate setting, and path movement, ensuring a high degree of match between the printing parameters and the design requirements of the composite sandwich structure to be printed. Setting the center point of the two extruder heads 310 as the path reference point lays the foundation for collinear rotation of the axes and precise trajectory movement in subsequent turning sections, avoiding sandwich structure forming errors caused by printing path offset. Basic material extrusion flow rate value.

[0064] S2. Based on the core width parameter, control the rotary motor 610 of the sliding drive mechanism 600 to drive the lead screw 620 to rotate, causing the two extrusion heads 310 to move horizontally to adjust the spacing. Set the basic extrusion flow rate of the substrate of the extrusion mechanism 300 and the basic extrusion flow rate of the filling material of the center filling mechanism 400. Usually, the printing layer thickness needs to be set first. The basic extrusion flow rate of the substrate is the substrate extrusion flow rate that can meet the preset printing layer thickness at the reference moving speed of the extrusion head 310; the basic extrusion flow rate of the filling material is the filling material extrusion flow rate that meets the preset printing layer thickness and reference core width at the reference moving speed of the connecting table 100. Since the printing layer thickness is usually fixed, the subsequent extrusion flow rate of the filling material can be adjusted according to the other two variables. Of course, the printing layer thickness can also be set to float, in which case the substrate extrusion flow rate and the filling material extrusion flow rate need to be adjusted accordingly according to the required printing layer thickness.

[0065] The precise adjustment of the spacing between the extrusion heads 310 is achieved by rotating the lead screw 620 driven by the rotary motor 610. In conjunction with the characteristics of the reverse thread section of the lead screw 620, it is ensured that the two extrusion heads 310 move synchronously and that their center point is always collinear with the rotation axis of the mounting bracket 200, thus ensuring the symmetry and precision of the core width adjustment. The basic extrusion flow rate of the substrate and filler material is set in advance to provide a benchmark for the dynamic adjustment of the flow rate during the printing process, ensuring the orderly adjustment of the flow rate.

[0066] The substrate extrusion flow rate is matched with the reference moving speed of the extruder head 310. When the moving speed of the extruder head 310 is greater than the reference moving speed, the substrate extrusion flow rate output by the extrusion drive mechanism 330 needs to be increased based on the substrate extrusion flow rate. Similarly, when the moving speed of the extruder head 310 is less than the reference moving speed, the substrate extrusion flow rate needs to be reduced based on the substrate extrusion flow rate. The substrate extrusion flow rate is directly proportional to the moving speed of the extruder head 310. Establishing a proportional matching relationship between the substrate extrusion flow rate and the moving speed of the extruder head 310 ensures the adaptability of the substrate extrusion amount and the printing trajectory under different moving speeds, avoids substrate accumulation or material breakage caused by speed changes, ensures uniform forming thickness of the substrate layer, and improves the forming quality of the substrate layer of the composite sandwich structure.

[0067] S3. Control the connecting stage 100 to move along the printing path, using the center point of the two extrusion heads 310 as the path reference point. Simultaneously drive the extrusion heads 310 of the two extrusion mechanisms 300 to extrude the substrate and the filler output head 410 of the central filler mechanism 400 to extrude the filler material, thereby realizing the integrated synchronous printing of the composite sandwich structure. During the printing process, according to the change of the sandwich width parameter, control the sliding drive mechanism 600 in real time to adjust the distance between the two extrusion heads 310, and at the same time, dynamically match the extrusion flow rate of the filler output head 410 according to the real-time distance between the two extrusion heads 310.

[0068] The synchronous discharge of extruder head 310 and filler output head 410 completes the integrated synchronous printing of the substrate layer and filler layer of the composite sandwich structure, avoiding the problem of weak interlayer adhesion caused by step printing and improving the overall mechanical properties of the sandwich structure. The spacing of extruder head 310 is adjusted in real time according to the sandwich width parameter to achieve dynamic adaptation of the sandwich width, breaking the printing limitation of fixed spacing and improving the versatility of the method. The filler flow rate is dynamically matched based on the real-time spacing of extruder head 310 to ensure that the extrusion amount of filler material is adapted to the sandwich width, avoiding the problems of insufficient filling or overflow.

[0069] When the printing path includes a turning segment, and the path of the turning segment is set as a preset turning arc, and the core width remains unchanged during the turn, step S3 is as follows: Upon reaching the starting point of the turn, the 3D printing composite nozzle mechanism (connecting platform 100) is controlled to move along the preset turning arc with the center point of the two extrusion heads 310 as the path reference point. Simultaneously, based on the central angle corresponding to the arc segment formed by the turning path of the connecting platform 100, the rotary drive mechanism 110 is controlled in real time to drive the mounting frame 200 to rotate around the rotation axis, so that the cumulative rotation angle of the mounting frame 200 during the turn is related to the connecting platform. The central angles of the arc segments formed by the 100-degree turning path are equal. The substrate extrusion flow rates of the two extrusion heads 310 are adjusted synchronously through their respective extrusion drive mechanisms 330, so that the extrusion flow rate of the inner extrusion head 310 is less than that of the outer extrusion head 310. According to the moving speed of the inner extrusion head 310 and the moving speed of the outer extrusion head 310 during the turn, the moving speed of the inner extrusion head 310 decreases and the moving speed of the outer extrusion head 310 increases, so the extrusion flow rate of the outer extrusion head 310 increases and the extrusion flow rate of the inner extrusion head 310 decreases.

[0070] It is understandable that controlling the 3D printing composite nozzle mechanism (connecting platform 100) to move in an arc is mainly achieved by the 3D printing equipment through driving and controlling the moving head to perform composite movement along the X and Y axes to achieve arc movement.

[0071] The rotating drive mechanism 110 drives the mounting bracket 200 to rotate precisely, and combined with flow differential control, it realizes turning printing, which simplifies the turning operation steps and improves the printing efficiency in scenarios such as small-angle turns and narrow core widths. Similarly, it adjusts the extrusion flow based on the difference in the inner and outer moving speeds to ensure that the substrate layer of the turning section is formed regularly, avoiding accumulation and material breakage problems, and adapting to the turning printing needs that do not require width adjustment.

[0072] Reference Figure 9 and Figure 10 When the core width needs to be widened during the turn to form a thicker corner wall structure at the corner, in step S3, when the 3D printing composite nozzle mechanism enters the turning section, the turning collaborative printing step is executed, specifically including steps S31, S32 and S33.

[0073] S31. Upon reaching the preset position of the turning segment, based on the central angle corresponding to the arc segment formed by the turning path and the current core width, the rotary motor 610 of the sliding drive mechanism 600 drives the lead screw 620 to rotate, causing the two extrusion heads 310 to move in opposite directions to widen the gap to the first preset gap. It can be understood that, to ensure the extrusion flow rate of the filler output head 410 meets the filling requirements, the extrusion flow rate of the filler output head 410 will be increased synchronously according to the widening ratio of the extrusion head 310 gap. The preset position of the turning segment is a position with a preset distance from the starting point of the turn; this preset distance is to allow time for the two extrusion heads 310 to adjust the core width. By allowing operation time for the extrusion head 310 gap adjustment through the preset position, the core width is ensured to be smoothly adjusted to the first preset gap before the turn, avoiding printing errors due to insufficient adjustment time. The synchronous increase in filler flow rate according to the widening ratio ensures that the extrusion amount of the filling material matches the widened core width, avoiding insufficient filling. The widening of the gap is a gradual process, and the filler flow rate also gradually increases during the widening process.

[0074] S32. The 3D printing composite nozzle mechanism is controlled to move along a preset turning arc with the center point of the two extrusion heads 310 as the path reference point. At the same time, according to the central angle corresponding to the arc segment formed by the turning path, the rotary drive mechanism 110 is controlled in real time to drive the mounting frame 200 to rotate around the rotation axis, so that the cumulative rotation angle of the mounting frame 200 during the turn is equal to the central angle corresponding to the arc segment formed by the turning path of the connecting table 100. Simultaneously, the substrate extrusion flow rate of the two extrusion heads 310 is adjusted through their respective extrusion drive mechanisms 330, so that the extrusion flow rate of the inner extrusion head 310 is less than that of the outer extrusion head 310. According to the moving speed of the inner extrusion head 310 and the moving speed of the outer extrusion head 310 during the turn, the moving speed of the inner extrusion head 310 decreases and the moving speed of the outer extrusion head 310 increases, so the extrusion flow rate of the outer extrusion head 310 increases and the extrusion flow rate of the inner extrusion head 310 decreases.

[0075] Using the center point of the two extrusion heads 310 as a reference point, the nozzles move along a preset turning arc. Combined with a control method where the cumulative rotation angle of the mounting bracket 200 is equal to the turning center angle, the three nozzles can rotate and adjust their angles to adapt to the printing direction, thus forming a stable three-layer sandwich structure and achieving offset-free arc-shaped turning printing. The extrusion flow rate is adjusted according to the difference in moving speed between the inner and outer extrusion heads 310 during the turn, ensuring that the flow rate matches the moving speed and path length. This solves the problem of substrate accumulation on the inner side and insufficient substrate on the outer side, guaranteeing the regularity of the substrate layer formation in the turning section. The flow rate of the two extrusion heads 310 is independently adjusted by the two extrusion drive mechanisms 330, achieving precise differential flow rate control to adapt to the flow rate requirements of different turning angles.

[0076] S33. After the turning segment completes its movement along the preset turning arc, the rotary motor 610 of the sliding drive mechanism 600 drives the lead screw 620 to rotate in the opposite direction, causing the two extrusion heads 310 to move towards each other to narrow the gap to the second preset gap. At the same time, the extrusion flow rate of the filler output head 410 is reduced synchronously according to the narrowing ratio of the gap between the extrusion heads 310. Usually, the second preset gap is equal to the first preset gap. Of course, if the structural width needs to be changed after the turn, the second preset gap will not be equal to the first preset gap.

[0077] Of course, in some other embodiments, if the wall needs to maintain the wall thickness at the turning point or be further widened after the turn, in step S33, after the turning segment moves along the preset turning arc, the current spacing between the two extrusion heads 310 can be maintained to continue printing, or the rotary motor 610 of the sliding drive mechanism 600 can be controlled to drive the lead screw 620 to rotate in the forward direction, causing the two extrusion heads 310 to move in opposite directions to widen the spacing to the third preset spacing.

[0078] The rotary motor 610 drives the lead screw 620 to rotate in the opposite direction, precisely narrowing the gap between the extruder heads 310 to the second preset gap, quickly restoring the core width for normal printing, and ensuring printing continuity after the turn. The filler flow rate is simultaneously reduced according to the gap narrowing ratio, achieving real-time matching between the filler flow rate and the core width, avoiding filler material overflow caused by the reduced gap, and ensuring the forming quality of the filler layer after the turn. The gap narrowing is a gradual process, and the reduction in filler flow rate is also a gradual process.

[0079] In step S3, a spacing threshold is set. When the real-time spacing between the two extrusion heads 310 is greater than the spacing threshold, the filling head drive mechanism 430 is controlled to drive the filling output head 410 to reciprocate along the horizontal sliding direction of the two extrusion heads 310, so that the filling material covers the sandwich area between the two extrusion heads 310. When the real-time spacing between the two extrusion heads 310 is detected to decrease to or below the spacing threshold, the filling head drive mechanism 430 is controlled to stop driving the filling output head 410 to reciprocate and to return the filling output head 410 to the center position of the two extrusion heads 310. By setting the spacing threshold, the movement mode of the filling output head 410 is automatically switched. When the sandwich width is large, the filling head drive mechanism 430 drives the filling output head 410 to reciprocate, ensuring that the filling material evenly covers the entire sandwich area and reducing the filling blind area under wide spacing. When the spacing shrinks to below the threshold, the filling output head 410 is returned to the center position to ensure the filling accuracy under narrow spacing and to achieve the optimal filling method under different sandwich widths.

[0080] The distance between the two extrusion heads 310 can be detected by a distance sensor or by detecting the rotation angle of the rotary motor 610. For example, an angular displacement detection element can be configured for the rotary motor 610 to collect the rotation angle (number of revolutions) of the motor in real time. Based on the lead of the lead screw 620, the rotation angle of the motor is converted into the linear displacement of a single extrusion head 310. Utilizing the transmission characteristics of the reverse threads of the first thread section 621 and the second thread section 622 of the lead screw 620, the linear displacement of a single extrusion head 310 is multiplied by 2 to obtain the change in the distance between the two extrusion heads 310. Combined with the initial distance between the two extrusion heads 310, the real-time distance is calculated. The distance between the two extrusion heads 310 increases when the rotary motor 610 rotates forward and decreases when the rotary motor 610 rotates in reverse. By combining the angular displacement detection element with the lead conversion method of the lead screw 620, the spacing detection is directly achieved using the rotary motor 610 of the sliding drive mechanism 600, without the need for additional displacement sensors. The conversion logic based on the reverse thread characteristics ensures the accuracy of the spacing detection, enabling real-time and high-precision acquisition of the real-time spacing of the extrusion head 310, providing reliable data support for flow regulation and reciprocating motion control.

[0081] The reciprocating speed of the filler head output head 410 driven by the filler head movable drive mechanism 430 is positively correlated with the real-time distance between the two extrusion heads 310. The larger the distance between the extrusion heads 310, the faster the reciprocating speed of the filler head output head 410 driven by the filler head movable drive mechanism 430; the smaller the distance between the extrusion heads 310, the slower the reciprocating speed of the filler head output head 410 driven by the filler head movable drive mechanism 430. This ensures that the filler output head 410 reciprocates at a faster speed under a wide distance, achieving rapid and uniform distribution of the filler material; and reduces the reciprocating speed under a narrow distance to avoid filler material splashing due to excessive speed, ensuring filling accuracy, and achieving adaptive adjustment of the filler movement speed under different distances.

[0082] The extrusion flow rate of the filler material is directly proportional to the moving speed of the connecting stage 100 and the spacing of the extrusion heads 310. That is, when the sliding drive mechanism 600 adjusts the spacing of the extrusion heads 310 or the moving speed of the 3D printing composite nozzle mechanism (connecting stage 100) changes, the flow control component of the central filler mechanism 400 dynamically adjusts the extrusion flow rate of the filler output head 410 in real time, achieving a coordinated match between the filler extrusion amount and the core width and printing speed. This dual coordinated matching of filler flow rate, core width, and printing speed ensures that the flow rate can dynamically adapt in real time regardless of changes in the spacing of the extrusion heads 310 or adjustments to the printing speed, guaranteeing that the extrusion amount of the filler material always closely matches the actual printing requirements. This fundamentally avoids problems such as insufficient filling, overflow, and accumulation, improving the molding quality of the filler layer. Furthermore, the basic extrusion flow rate of the filler material is typically based on the reference moving speed of the connecting stage 100 and the basic spacing of the extrusion heads 310 (reference core width). The filler output head 410 not only moves with the connecting table 100 but may also reciprocate. The actual printing speed is related to the connecting table 100, while the reciprocating motion is only related to the material application method. Therefore, the filler material extrusion flow rate of the filler output head 410 is not entirely related to its own moving speed but is positively correlated with the moving speed of the connecting table 100. When the moving speed of the connecting table 100 is greater than its baseline moving speed, the filler material extrusion flow rate is increased based on the baseline flow rate; conversely, it is decreased. This eliminates the interference of the reciprocating motion of the filler output head 410 on flow rate adjustment, ensuring that the extruded filler material matches the print path length and print width. It provides a clear reference standard for flow rate adjustment, enabling precise and orderly dynamic adjustment of the filler flow rate and preventing insufficient filling or overflow.

[0083] The filler head drive mechanism 430 drives the reciprocating motion of the filler output head 410 to match the real-time spacing between the two extrusion heads 310. This ensures that the extreme positions at both ends of the reciprocating motion of the filler output head 410 are close to the inner sides of the two extrusion heads 310, guaranteeing no filling blind spots in the sandwich area. Matching the reciprocating motion of the filler output head 410 to the real-time spacing between the extrusion heads 310, with the extreme positions at both ends close to the inner sides of the extrusion heads 310, maximizes coverage of the sandwich area, avoids filling blind spots under wide spacing, ensures the integrity and uniformity of the filler layer, and improves the overall molding quality of the composite sandwich structure.

[0084] The 3D printing composite nozzle mechanism also includes a telescopic stop 700, with its two ends connected to two extrusion heads 310 respectively. During printing, the telescopic stop 700 extends and retracts synchronously with the change in the spacing between the extrusion heads 310 driven by the sliding drive mechanism 600, laterally limiting the filler material between the two extrusion heads 310 and preventing lateral spillage of the filler material. By extending and retracting synchronously with the spacing between the extrusion heads 310, the filler material is limited throughout the entire process, effectively preventing lateral spillage of the filler material due to flowability and equipment movement during printing (especially in wide-spacing and turning sections), ensuring a regular forming contour of the filler layer; at the same time, it slightly limits the edge of the substrate layer, reducing deformation of the substrate layer after extrusion and improving the adhesion between the substrate layer and the filler layer.

[0085] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A 3D printing composite nozzle mechanism, characterized in that, include: Connecting station (100); Mounting bracket (200) is installed on the connecting platform (100); Two extrusion mechanisms (300), including extrusion heads (310), are slidably mounted on the mounting frame (200) in the horizontal direction, thereby adjusting the distance between the two extrusion heads (310); The central filling mechanism (400) has a filling output head (410) with its output end opening facing downward and located between two extrusion heads (310) for discharging filling material into the middle of the material extruded by the two extrusion heads (310); When the real-time distance between the two extrusion heads is greater than the distance threshold, the control of the filling head moving drive mechanism drives the filling output head to reciprocate along the horizontal sliding direction of the two extrusion heads, so that the filling material covers the sandwich area between the two extrusion heads; when the real-time distance between the two extrusion heads is detected to decrease to the distance threshold or below, the control of the filling head moving drive mechanism stops driving the filling output head to reciprocate and drives the filling output head to return to the center position of the two extrusion heads. The filler output head (410) can move horizontally relative to the mounting frame (200), and the two extrusion heads (310) slide along the same horizontal straight line. The direction of movement of the filler output head (410) is parallel to the sliding direction of the extrusion mechanism (300). The opening direction of the filler output head (410) and the extrusion head (310) is set downward. The central filling mechanism (400) includes a feed pump (420) and a filler head movement drive mechanism (430). The feed pump (420) has an output pipe (421). One end of the filler output head (410) is movably sleeved on the output pipe (421) so that it can move horizontally along the output pipe (421). The filler head movement drive mechanism (430) is mounted on the mounting frame (200) and connected to the filler output head (410) for driving the filler output head (410) to move horizontally.

2. The 3D printing composite nozzle mechanism according to claim 1, characterized in that, The mounting bracket (200) is rotatably mounted on the lower end of the connecting platform (100) around a vertical axis. A rotary drive mechanism (110) is mounted on the connecting platform (100). The rotary drive mechanism (110) is connected to the mounting bracket (200) in a transmission manner to drive the mounting bracket (200) to rotate.

3. The 3D printing composite nozzle mechanism according to claim 1, characterized in that, It also includes a slider (500) and a sliding drive mechanism (600); the two sliders (500) are slidably mounted on the mounting bracket (200) in the horizontal direction; two extrusion mechanisms (300) are respectively connected to the two sliders (500) so as to move synchronously with the sliders (500); the sliding drive mechanism (600) is used to drive the sliders (500) to slide to adjust the distance between the two sliders (500).

4. The 3D printing composite nozzle mechanism according to claim 3, characterized in that, The sliding drive mechanism (600) includes a rotary motor (610) and a lead screw (620); the lead screw (620) has a first threaded section (621) and a second threaded section (622); the first threaded section (621) and the second threaded section (622) have opposite threading directions; both sliding members (500) are equipped with nut sleeves (510), and the nut sleeves (510) on the two sliding members (500) respectively cooperate with the first threaded section (621) and the second threaded section (622).

5. The 3D printing composite nozzle mechanism according to claim 1, characterized in that, The extrusion mechanism (300) includes an extrusion container (320) and an extrusion drive mechanism (330). The extrusion container (320) has a feed inlet (321) and a discharge outlet. A transition member (322) is installed between the extrusion head (310) and the discharge outlet of the extrusion container (320). One end of the transition member (322) is detachably connected to the end of the extrusion container (320), and the other end is detachably connected to the extrusion head (310). The transition member (322) gradually converges toward the extrusion head (310). The extrusion drive mechanism (330) is connected to the extrusion container (320) and is used to drive the material in the extrusion container (320) to flow toward the extrusion head (310) and be output.

6. The 3D printing composite nozzle mechanism according to claim 1, characterized in that, A telescopic stop (700) is provided between the two extrusion heads (310), and the output end of the filler output head (410) passes through the telescopic stop (700). The two ends of the telescopic stop (700) are respectively connected to the two extrusion heads (310) so that the end of the telescopic stop (700) can move with the corresponding extrusion head (310) and drive the telescopic stop (700) to extend and retract along the sliding direction of the extrusion head (310).

7. The 3D printing composite nozzle mechanism according to claim 1, characterized in that, The packing head moving drive mechanism (430) has a telescopic rod (431) that can extend and retract. An adapter (432) is connected to the telescopic rod (431). A pipe clamp assembly (433) is installed on the adapter (432). The pipe clamp assembly (433) is used to clamp the packing output head (410).

8. A 3D printing device, characterized in that, Includes the 3D printing composite nozzle mechanism as described in any one of claims 1 to 7.

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