3D printing device and process

Abstract

The present application relates to 3D printing device and process, it includes collection and analysis control system three-dimensional model data, on model support component to model support piece carries out layering slice, designs model layer piece, according to 3D printing flow, control system is completed 3D printing by telecommunication signal processing, transformation and output to 3D printer group, the present application is reasonable in design, compact structure and convenient to use.

Description

Technical Field

[0001] This invention relates to 3D printing apparatus and process. Background Technology

[0002] 3D printers contain different "printing materials" such as metal, ceramics, plastics, and sand. After the printer is connected to a computer, the computer controls the layering of printing materials to ultimately turn the blueprint on the computer into a physical object.

[0003] The design process for 3D printing is as follows: first, a model is created using computer modeling software, and then the completed 3D model is "divided" into layers of cross-sections, i.e. slices, to guide the printer to print layer by layer.

[0004] However, the existing feeding method has many problems, such as insufficient precision, inability to accurately measure temperature, and inaccurate positioning of the supporting carrier. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a 3D printing device and process.

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

[0007] A 3D printing device includes collecting and analyzing three-dimensional model data in a control system, slicing the model support component into layers on the model support assembly, and designing the model layers; according to the 3D printing process, the control system completes 3D printing for the 3D printer assembly through electrical signal processing, conversion and output.

[0008] The 3D printer assembly includes a base; a vertical frame is mounted on the base, and a Y-axis linear slide driven by a Y-axis drive unit is connected to the vertical frame via a connecting plate; a head connecting plate is mounted on the Y-axis linear slide, and a Z-axis linear push rod driven by a Z-axis drive unit is mounted on the head connecting plate; corner brackets for fixing the vertical frame are mounted on the base; an X-axis linear slide driven by an X-axis drive unit is mounted on the base, and a printing platform for placing the carrier is mounted on the X-axis linear slide; and a pressure block is mounted on the base.

[0009] A pump body connecting plate is connected to the lower end of the Z-axis linear push rod. A material cylinder is set on the pump body connecting plate. A screw feed pump driven by a pump drive motor is connected to the lower end of the material cylinder. A print head is set at the output end of the screw feed pump. The printing part screw section includes the screw feed pump.

[0010] As a further improvement to the above technical solution:

[0011] Inside the printer housing, a kilogram-level feed cylinder is located at the top, connected to a printing screw section. The printing platform is a printing platform section. A pressure device and an air compressor assembly are located on the printer housing. The printing screw section includes a screw extrusion section with a threaded extrusion channel for screw extrusion. A feed inlet is located on the screw extrusion section for connecting to the feed cylinder. Temperature control components are located at the inlet, outlet, and / or middle of the screw extrusion section. A printing nozzle is located at the outlet of the screw extrusion section. An extrusion motor is electrically connected to the screw extrusion section.

[0012] A supporting system for a 3D printing device includes a carrier changing unit for a printing platform used with a 3D printer assembly; the carrier changing unit is equipped with an output conveyor group or an output conveyor belt, and the output conveyor belt or output conveyor group is connected to a palletizing station; an input end of a sorting device is provided at the output end of the output conveyor group, and an output conveyor belt is provided at the output end of the input conveyor belt to form a rectangular carrier fixture for carrying 3D materials; the carrier fixture has an inspection process groove; a lateral push rod is provided at the output end of the input conveyor belt; the lateral push rod includes a side pusher; a front baffle is provided in front of the rear side pusher and a rear baffle is provided in rear;

[0013] The front and rear baffles form a stepped structure and create a side push opening;

[0014] The sorting device is equipped with an inclined swing base and a support platform that rotates on the inclined swing base via the XX rotating shaft.

[0015] The conveying direction of the vehicle tooling on the support platform is oblique to the center line of the XX rotating shaft;

[0016] The platform has a platform input station at point A and a platform output station at point B at the conveyor inlet and outlet, respectively.

[0017] As a further improvement to the above technical solution:

[0018] Ventilation holes are distributed on the support platform. Along the YY direction perpendicular to XX, a swing guide groove A and an oblique process opening are provided on the support platform. Tilting station sensors and positioning horizontal station sensors are respectively provided on both sides of the XX rotating shaft below the support platform. A support part is provided above the support platform. A middle hinge frame is swing-hinged below the support part through a swing hinge seat and elastically connected with an auxiliary spring. A pitch drive motor is inverted on the support part. A pitch drive frame is connected to the lower end of the pitch drive motor. A pitch drive shaft shoulder is connected to the lower end of the pitch drive frame. A swing guide groove B along the YY direction is provided on the middle hinge frame. The pitch drive shaft shoulder slides in the swing guide groove B along the YY direction.

[0019] A conical contact rotating body is provided on both sides of the pitch drive frame C on the intermediate hinge frame, which is used to position and contact the adjacent sides of the carrier tooling; a hinge driven connection part is provided on the intermediate hinge frame, and a lower connecting rod is hinged to the lower end of the hinge driven connection part. A mating spring pad is provided on the lower connecting rod to contact the upper and lower surfaces of the corresponding swing guide groove A of the support platform.

[0020] A 3D printing process involves, firstly, modeling the product according to parameters in a control system, slicing and stacking the layers, and outputting signals to the 3D printer; then, the 3D printer feeds and prints the material onto a fixture; finally, the fixture containing the finished product is output.

[0021] In the feeding and extrusion process, firstly, in the conveying section, the material is compacted and preheated; then, in the melting section, it is compressed and melted, compacted a second time, and plasticized; finally, in the metering section, the melt is conveyed, plasticized to a uniform viscous flow state, and then extruded and cooled to form a shape.

[0022] A 3D printing auxiliary process includes the following steps: the carrier changing unit moves the carrier tooling unidirectionally between the printing platform and the delivery conveyor belt or unidirectionally between the printing platform and the output conveyor group.

[0023] When an unloaded vehicle tooling is transferred unidirectionally from the delivery conveyor belt to the vehicle changing unit...

[0024] S1, the vehicle tooling is transferred from the output conveyor group to the sorting device;

[0025] S2, the vehicle tooling achieves positioning by pitching through the sorting device;

[0026] S3, the carrier tooling is transferred unidirectionally from the sorting device to the delivery conveyor belt.

[0027] As a further improvement to the above technical solution:

[0028] In S2, S2.1, the lateral push rod retracts, causing the lateral push opening to face the output end of the conveyor belt and be blocked by the rear baffle. At this time, the support platform is in a horizontal state and receives the carrier fixture. S2.2, the lateral pusher moves the carrier fixture forward, and the pitch drive motor drives the pitch drive shaft shoulder to slide in the swing guide groove B along the YY direction through the pitch drive frame, realizing the swing of the intermediate hinge frame. This allows the hinge driven connection part to drive the docking spring pad through the hinge driven connection part, causing the support platform to rise. At the same time, the conical contact rotating body descends to the inclined process opening, and the support platform becomes tilted. S2.3, the conical contact rotating body rotates in opposite directions and contacts the side wall adjacent to the carrier fixture, rotating and adjusting for positioning. S2.4, the pitch drive motor drives the support platform to return to a horizontal state, and the conical contact rotating body rises and resets. S2.5, the lateral push rod moves forward into the support platform and pushes out the carrier fixture.

[0029] This invention uses an AMF / STLdata control system to model 3D data, with model support components (carriers) for model layering and execution of the 3D printing process. Electrical signal processing, conversion, and output control the 3D printer assembly. It features a clear structure, achieving at least three degrees of freedom of movement, multi-point temperature monitoring, precise screw extrusion, and a feed inlet (printing nozzle) for accurate output.

[0030] Temperature control components enable monitoring; the screw extrusion section performs extrusion and mixing, driven by an extrusion motor; the threaded extrusion channel serves as the screw extrusion point; the output conveyor group enables carrier output; a finishing device enables gravity positioning of the carrier during descent; the carrier is fed into and out of the conveyor belt for transport; the carrier fixture is used for output after 3D automated printing; the inspection process slot is well-designed for guidance; the lateral push rod section provides guidance and transport; lateral push is achieved through the side pusher; positioning is achieved through the rear baffle; the side push opening is rationally designed; the front baffle prevents subsequent carriers from moving forward; the inclined swing base provides pitch support; the support platform provides load positioning; the platform output station provides output; ventilation holes enable negative pressure adsorption and positive pressure blowing; the corresponding swing guide slot provides guidance; and the hinge enables pitch and inclined... The process opening is convenient. The tilting station sensor and the positioning horizontal station sensor provide positioning support. The upper support provides guidance. The middle hinged frame provides swing support. The swing hinge seat provides pitch support. The auxiliary spring provides buffer reset. The pitch drive motor provides drive. The pitch drive frame provides connection and avoids the carrier. The pitch drive shaft shoulder provides support. The conical contact rotating body can rotate to contact the side wall to adjust the contact. The corresponding swing guide groove provides pitch guidance. The hinged driven connection provides linkage. The lower connecting rod and the docking spring pad realize the tilting positioning and horizontal pushing of the platform, thereby realizing the automatic positioning, automatic output and subsequent blocking of the carrier. This invention is reasonably designed, low cost, sturdy and durable, safe and reliable, simple to operate, time-saving and labor-saving, cost-saving, compact in structure and easy to use. Attached Figure Description

[0031] Figure 1 This is the general working principle of the 3D printer of the present invention.

[0032] Figure 2 This is a schematic diagram of the existing structure of the screw of the present invention.

[0033] Figure 3 This is a schematic diagram of the printed structure of the present invention.

[0034] Figure 4 This is a schematic diagram of the nozzle structure of the present invention.

[0035] Figure 5 This is a conventional control diagram of the present invention.

[0036] Figure 6 This is a schematic diagram of the screw structure of the present invention.

[0037] Figure 7 This is a schematic diagram of the vehicle replacement unit of the present invention.

[0038] Figure 8 This is a schematic diagram of the threaded extrusion channel of the present invention.

[0039] Figure 9 This is a schematic diagram of the output transmission group of the present invention.

[0040] Figure 10 This is a schematic diagram of the structure of the present invention being fed into the conveyor belt.

[0041] Figure 11 This is a schematic diagram of the structure of the support platform of the present invention.

[0042] Figure 12 This is a schematic diagram of the structure of the intermediate hinge frame of the present invention.

[0043] Figure 13 This is a schematic diagram of the pitch drive motor of the present invention.

[0044] Figure 14 This is a schematic diagram of the thermocouple structure of the present invention.

[0045] The components include: 1. Control system; 2. AMF / STL data; 3. 3D model data; 4. Model support components; 5. Model layers; 6. 3D printing process; 7. Electrical signal processing, conversion, and output; 8. 3D printer assembly; 9. Model support components; 10. Base; 11. Corner pieces; 12. X-axis drive unit; 13. Printing platform; 14. X-axis linear slide; 15. Pressure block; 16. Vertical frame; 17. Z-axis drive unit; 18. Z-axis linear actuator. 19. Printer head connecting plate; 20. Y-axis linear slide; 21. Y-axis drive unit; 22. Connecting plate; 23. Material cylinder; 24. Pump drive motor; 25. Pump body connecting plate; 26. Screw feed pump; 27. Printer head; 28. Printer housing; 29. ​​Kilogram-level feeding cylinder; 30. Printing screw unit; 31. Printing platform unit; 32. Pressure device; 33. Air compressor assembly; 34. Feed inlet; 35. Temperature control assembly; 36. Screw extrusion unit; 37. Printing nozzle 38. Extrusion motor; 39. Carrier changing unit; 40. Threaded extrusion channel; 41. Output conveyor group; 42. Finishing device; 43. Feed conveyor belt; 44. Output conveyor belt; 45. Carrier fixture; 46. Inspection process tank; 47. Side push rod section; 48. Side pusher; 49. Rear baffle; 50. Side push opening; 51. Front baffle; 52. Angled swing base; 53. Support platform; 54. Platform output station; 55. Ventilation hole; 56. Swing guide 57. Sloping process opening; 58. Tilt station sensor; 59. Positioning horizontal station sensor; 60. Upper support; 61. Intermediate hinge frame; 62. Swing hinge seat; 63. Auxiliary spring component; 64. Pitch drive motor; 65. Pitch drive frame; 66. Pitch drive shaft shoulder; 67. Conical contact rotating body; 68. Swing guide groove B; 69. Hinge driven connection; 70. Lower connecting rod; 71. Butt spring pad; 72. Thermocouple. Detailed Implementation

[0046] The screw extrusion 3D printer device of this application is based on the material properties of energetic nano-thermoplastic composite materials, and proposes a basic design scheme for the screw extrusion 3D printer device.

[0047] like Figure 1-13 The demonstration showcases the working principle of a screw extrusion 3D printer based on FDM technology, including modeling, slicing, and melt extrusion. In the extrusion stage, solid granules are fed into the nozzle channel through an extrusion conveyor system. After being melted and plasticized by the heating system, the material is accumulated layer by layer in the nozzle according to a predetermined path and driven by the feeding system. Finally, it is extruded by the nozzle at a constant temperature, quantity, and pressure, and after cooling on the printing table, it is shaped into a complete product.

[0048] In a screw extrusion molding system, materials sequentially pass through three main reaction zones: the solid conveying zone, the melting zone, and the metering zone. Figure 1 As shown in Figure c, by designing and optimizing the structure and process parameters of each functional section, the aim is to achieve stable continuous extrusion of materials.

[0049] like Figure 2 As shown, it mainly includes a CNC system, a transmission device, a mechanism frame (box), a pneumatic extrusion system, a melt extrusion zone, and a temperature control feedback system.

[0050] The CNC control system mainly consists of two parts: motion control and temperature control. The motion control system moves the screw, worktable, etc., according to a predetermined speed and direction. The control accuracy of the motion control system directly affects the final printing accuracy. For example, the pulse equivalent of the Z-axis motor is the layer thickness of the printed part. The feed zone consists of an X, Y, and Z-axis three-axis feed motion system, which mainly completes the three-dimensional forming motion of the nozzle and work platform. The temperature control system is mainly responsible for heating the plasticizing and melting extrusion device and preheating the hot bed, plasticizing and melting the solid material to make it fluid. The accuracy of temperature control has an important impact on the quality of the printed parts and the setting of other process parameters. The transmission device is responsible for transmitting the torque of the motor to the actuators such as the lead screw and toothed belt, so that the worktable moves along a predetermined trajectory. The selection of the transmission device and the efficiency of transmission have an important impact on the printing quality. The structural frame is responsible for providing a stable printing environment for the printing work. For some temperature-sensitive materials, the structural frame also plays a role in sealing and heat preservation. The pneumatic extrusion system controls the flow of powder and pushes it into the screw system. The melting and extrusion zone mainly completes the melting and plasticizing of the printing material, extrusion transmission, and extrusion molding. Because energetic materials are subjected to shearing, friction, extrusion, and solid-liquid transition during screw extrusion, they are prone to combustion or explosion accidents. Extrusion equipment used for continuous processing of energetic materials needs to have various safety features.

[0051] Screw extrusion systems are used to safely and continuously transport energetic materials, transforming solid printing materials into a viscous flow state under the influence of a thermal field. At this point, the extruded material has plasticity, meeting the requirements for printing, such as... Figure 3 The device includes a stepper motor, coupling, micro extrusion screw, barrel, die head, nozzle, temperature control system, and feeding device;

[0052] The extrusion screw only needs to ensure stable and continuous extrusion under the action of external field and screw thrust. Therefore, the extrusion screw does not need to be specially designed like the plasticizing screw; it can be designed with equal depth and spacing. Since the material enters the extrusion screw only by internal pressure, the screw is made smooth at the material inlet to ensure smooth material entry.

[0053] The barrel and extrusion screw work together to transport and stably extrude the rubber compound. The clearance between the screw and barrel is controlled by tolerance, similar to the design of the plasticizing and melting section barrel, as the smaller size of the extrusion barrel makes it inconvenient to add an inner liner. Flange structures are installed at both ends of the barrel; one end mates with the die head to form a closed flow channel, and the other end supports the extrusion motor. For ease of manufacturing, the flange at the motor support end is machined separately from the barrel and then welded together. The outer end of the barrel is used to wind a resistance heating coil. A temperature sensing hole is designed to house a temperature sensor for real-time temperature detection and adjustment.

[0054] The extrusion head connects the barrel and the printing nozzle. Unlike conventional extrusion heads, the extrusion head also connects to the printing nozzle. Therefore, the extrusion head is mainly used for pressure building, changing the material's spiral motion to a linear motion, ensuring that the material inside the screw smoothly enters the nozzle. To precisely control the temperature of the extruded material and ensure stable extrusion, a heating rod and temperature measuring port are designed at the extrusion head.

[0055] The printing nozzle is the final "checkpoint" to ensure smooth material extrusion. The nozzle structure, diameter, and manufacturing precision directly affect the accuracy of the printed parts. Here, the molten material is further plasticized due to the tensile and shearing action caused by a large velocity gradient. To prevent material stagnation and decomposition, a straight-through nozzle is selected.

[0056] The printer housing (printing system) is the load-bearing structure of the entire printer, comprising the printer housing, printing platform, lifting device, and printing control system, such as... Figure 2 and Figure 4as shown. A metal-sealed printing box is adopted to ensure constant internal temperature and guarantee the safety of the printing process; 304 metal is selected as the box material. The improved overall frame is designed as an inner-outer nested type, with the outer box functioning for support and protection, and the inner frame responsible for lifting the workbench. To ensure uniform force on the inner frame and smooth lifting, ball screw transmission structures and guide optical shafts are respectively installed on the left and right sides of the inner border; the printing lifting device includes a screw rod device; the printing system adopts a customized layered printing system, which is easy to operate.

[0057] The accuracy and stability of the transmission system largely determine the accuracy, surface quality and printing efficiency of printed parts. A 3D printer itself is equivalent to a small numerical control machine tool, which needs to automatically and accurately control the displacement, direction and speed of each execution structure according to command signals to complete three-axis linkage.

[0058] Since the material barrel part has a large volume and is inconvenient to move, the method of moving the work platform is adopted, which ensures the printing accuracy to a greater extent. The present invention adopts a transmission scheme in which the work platform performs X and Y plane linkage, and the Z axis drives the workbench to move up and down. For the X and Y axes, due to their fast movement speed, high frequency and small load, a stepper motor is used to drive a synchronous toothed belt as the transmission mechanism. For the Z axis, due to its large load and high accuracy requirements, a stepper motor plus a ball screw is used as the transmission mechanism. Optical shafts are used for guiding on all X, Y and Z axes. Before the improvement, the Z-axis screw only drove the printing platform, while the improved Z-axis ball screw needs to support the entire workbench.

[0059] When the motor is working, the stepper motor transmits torque to the ball screw through the coupling, and then drives the workbench to move up and down. Through measurement, the mass of the workbench and its components is between 6 and 8 kg, and the maximum mass is substituted into the torque formula

[0060]

[0061] In the formula, F —— the maximum load during operation, F= , —— the lead of the ball screw,

[0062] —— transmission efficiency, 0.9 ;

[0063] Substituting the data, when TL is less than the rated torque, the motor torque meets the requirements. The ball screw drives the inner frame to descend through the ball nut on the inner frame. When the ball screw mechanism is in operation, the nut only bears axial load, and the radial load is borne by the guide component. Since the tensile strength of the ball screw is far greater than its compressive strength, the drive motor of the Z axis is arranged above the inner frame in the design, and the frame is pulled to lift through the ball screw.

[0064] (1) Calculation of axial stress of ball screw

[0065]

[0066] In the formula, F is the axial tensile force on the ball screw, and F = 0.5 * the weight of the inner frame;

[0067] A—Minor diameter section of the ball screw. ;

[0068] (2) Calculation of radial stress of ball screw

[0069]

[0070] In the formula, J is the moment of inertia of the leadscrew. ;

[0071] T—The torque that the leadscrew can withstand.

[0072] Substituting into formula 1-3, we get... ;

[0073] Calculations show that the structural strength of the ball screw meets the requirements.

[0074] Control system and control flowchart

[0075] (1) The servo control system is mainly used to control the speed and direction of the stepper motor, accurately position the worktable and lift the work platform, and ensure stable material extrusion. In existing 3D printers, the extrusion mechanism and the work platform are powered by 42 stepper motors, and the transmission method is belt drive and ball screw drive. The extruder head moves in the XOY plane, and the work platform moves up and down in the Z direction. Due to the large volume and heavy weight of the extrusion part of the screw-type 3D printer, it is not practical to move it according to the existing printer control method. It is difficult to guarantee both printing quality and working stability. Therefore, the drive method of this design is based on the existing 3D printer drive and some improvements are made to it. The extrusion device is fixed, the work platform moves in a plane and lifts and lowers. The original extrusion motor controls the rotation of the extrusion screw motor, while the plasticizing and melting screw is controlled separately by an additional control board. This can maximize the use of the existing drive system, reduce the workload, and ensure stability and reliability. Since its drive principle is still stepper motor control, the servo system is still a stepper motor servo system.

[0076] (2) The hardware adopts the Arduino microcontroller electronic design platform, which consists of a programmable circuit board (also known as a microprocessor) and an Eclipse-based IDE development environment. To facilitate secondary development, Arduino was designed from the outset as an open and open-source platform, and many desktop computer development projects currently utilize Arduino. Arduino has rich interfaces, including SPI and UART serial communication, and is highly scalable. It can read digital or analog signal inputs from different sensors and convert them into outputs in real time.

[0077] This design uses an Arduino MEGA2560 control board with an additional Ramps 1.4 expansion board. The expansion board's purpose is to increase the control board's inputs and outputs for connecting to a motor driver, as the control board cannot be directly connected to a motor driver. The Mega2560 has 54 digital input / output channels, 15 of which can be used as pulse outputs, and 15 for analog inputs (such as analog signals from the temperature sensor at the printhead). The input analog signals are converted into digital signals by an internal ADC. The 4KB EEPROM has a memory function, so in the event of a power outage, the printer will resume printing from where it left off after power is restored. Different digital interfaces are added to the expansion board as needed to meet various requirements.

[0078] (3) IDE is an abbreviation for Integrated Development Environment. The Arduino IDE is written in open-source software such as Java, AVR-GCC, and Processing. Like the Arduino development board, its source code is also publicly available. In the Arduino IDE editing interface, you can select the type of development board, the COM port, monitor serial communication, and call official library functions and third-party functions. The interface is similar to other development environments, including a menu bar, a program editing area, and an error message area. When improving an existing control system, you open the 3D printer's open-source code in the Arduino IDE, modify the configuration file according to requirements, and then recompile the code. After successful compilation, upload it to the Arduino control board. If compilation fails, modify the code according to the prompts. However, the Arduino IDE lacks debugging functionality, which is a significant drawback. Figure 7 It is a compiled printing system.

[0079] Temperature control system

[0080] Temperature control systems are crucial for screw-type 3D printers. The viscosity of polymer materials is highly dependent on temperature, especially for temperature-sensitive thermoplastics like plastics. The effectiveness of temperature control directly impacts print quality and accuracy. Furthermore, the improved printers have a longer heating process compared to previous models, meaning even slight deviations can have significant cumulative effects over time. If the temperature is too high, the material viscosity decreases, increasing fluidity and resulting in a higher extrusion volume per unit time at the same screw speed, leading to "nodules" on the printed surface. Excessive temperature can cause thermal decomposition of the material, damaging its original properties and even scorching. Conversely, if the temperature is too low, the material may not reach the proper extrusion state, potentially clogging the nozzle and preventing proper adhesion after extrusion. Therefore, minimizing temperature control deviations and fluctuations in 3D printers is essential. The temperature control system for FDM-based screw-type 3D printers consists of two parts: heated bed and extrusion nozzle temperature control, and plasticizing and melting extrusion barrel temperature control. Similar to the motion control system, the former is already included in the existing printer's temperature control system; only the preheating temperature of the heated bed and the extrusion temperature need to be modified according to the printing material. The latter, however, is an improvement on the extrusion unit in this design, and the original temperature system lacks this temperature control, so it requires separate control. This section only introduces the working principle of the heating system for the heated bed and extruder head, focusing on the implementation process of the temperature control system for the plasticizing and melting extrusion section. Thermocouples are installed at the ends, middle, and / or tail of the screw extrusion section to achieve temperature monitoring.

[0081] The temperature control system is a closed-loop system, mainly composed of a temperature microcontroller, PWM temperature controller, heating element, and temperature acquisition modules. First, the temperature sensor acquires the temperature of the heated bed, extruder head, or barrel. The analog signal is converted into a digital signal by an A / D conversion module and transmitted to the microcontroller. The microcontroller reads the feedback digital signal, compares it with the set temperature value, and adjusts the temperature using a PID temperature control algorithm. Then, the PWM temperature controller adjusts whether the heating element is heating. This system can monitor the temperature of the heating components in real time and provide feedback to the controller for real-time adjustment. This cycle repeats, ensuring the temperature remains in a dynamic equilibrium state, guaranteeing smooth printing.

[0082] High-power heating rods are used for heating the extruder head, directly affecting the properties of the extruded material. The heating rod in a 3D printer, also known as a single-end heating section, works as follows: the controller's timer output port outputs a duty cycle-adjustable PWM wave to control the switching of a transistor, which in turn controls the power supply to heat the heating rod. The transistor's on-time and heating time increase with the increase of the duty cycle; conversely, the smaller the duty cycle, the shorter the on-time and heating time. Heating coils are mainly used in the plasticizing and melting sections, the material storage section, and the extrusion section. Within the barrel, some heat is transferred through the external thermal field, and another part is dissipated by the shear viscosity of the screw. Therefore, when measuring temperature, the sensor probe should be positioned as close to the material as possible to obtain a more accurate temperature reading.

[0083] (3) The heated bed is designed to prevent the large temperature difference between the molten material and the worktable during extrusion from affecting the printing quality and causing warping. The temperature of the heated bed must be lower than the melting point of the material to ensure proper bonding and curing of the extruded material, but it cannot be set too low to avoid warping during molding. Therefore, the temperature of the heated bed must be well controlled to keep it within a reasonable range. For conventional printing materials ABS / PLA, the temperature of the heated bed is generally set at 110℃ for the former and 60℃ for the latter.

[0084] (4) Cooling device based on safety during printing. To prevent safety hazards caused by excessive polymer shear heat generation or rapid local temperature rise during printing, a temperature self-regulating cooling system is added to the outside of the extruder barrel. When the temperature exceeds the set temperature, the cooling system is immediately triggered to cool down. The cooling system consists of temperature control software, a fan, and a circulating water cooling system. When printing energetic materials (<100℃), it can ensure a constant temperature.

[0085] To ensure smooth extrusion of high-filler polymers, this invention designs an air compressor and a barrel to increase the extrusion force of the high-filler nanoparticle polymer composite material, enabling the composite powder to be extruded smoothly. The air compressor has a pressure range of 0.1-10 MPa, capable of pushing 2L of powder to extrude at an extrusion rate of 100 mm / min. The air pressure is controlled by a pressure valve, which also controls the powder feed rate. The extrusion speed is controlled collaboratively by the air compressor and the screw. During extrusion, a feed tube diameter >15 mm is selected to ensure uniform powder flow inside the feed tube. The feed tube is kept vertically positioned, and a barrel support is designed to ensure a smooth extrusion path.

[0086] The localized temperature distribution and temperature rise effect of energetic materials during screw extrusion can easily lead to dangerous accidents. However, the molding process that causes the material temperature rise is difficult to detect with existing testing techniques, such as shearing, friction, and extrusion heat generation during extrusion. Simulation technology can conveniently and efficiently investigate the actual screw extrusion process of energetic materials, identify key factors affecting processing safety, and thus optimize screw extrusion equipment to avoid dangerous accidents. Screw extrusion molding of nano-energetic thermoplastic composites is a solid-melt transformation deformation process of materials under specific temperature and pressure. After entering the screw system, the material gradually changes from a solid state to a plasticized state, and finally, the material fills the entire screw channel in a viscous flow state, that is, the material transforms from a highly elastic state to a viscous flow state. Therefore, the material in the screw extrusion system is divided into three processes: solid conveying section, compression and plasticizing section, and melt conveying section.

[0087] This invention utilizes ANSYS-Fluent software to analyze the internal flow and temperature fields of a screw extrusion system, obtaining the internal flow conditions and temperature distribution. It sets the value ranges of key screw extrusion parameters that meet the operating conditions, uses the controlled variable method to perform finite element analysis on each parameter, compares the simulation data results, selects the optimal parameters, and establishes an optimization model. The simulation results of the optimized model better meet the requirements of the printing operating conditions, ensuring a safe and stable supply of materials during the extrusion process.

[0088] The plasticizing process of materials in the barrel is achieved by the external force provided by the rotation of the screw, thereby achieving the purpose of shearing and extruding the materials.

[0089] The output of screw extrusion 3D printing is directly proportional to the screw speed. The plasticizing process of the material in the barrel is achieved by the external force provided by the screw rotation, thereby achieving the purpose of shearing and extruding the material.

[0090] The present invention has been described in detail for the purpose of making the disclosure clearer, and the prior art will not be listed one by one.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. It is obvious to those skilled in the art that multiple technical solutions of the present invention can be combined. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A supporting system for a 3D printing device, characterized in that... The system includes a carrier changing unit (39) for a printing platform (13) for a 3D printer assembly (8), an outgoing conveyor belt (44), and an incoming conveyor belt (43); the carrier changing unit (39) is equipped with an outgoing conveyor belt (44) and the outgoing conveyor belt (44) is connected to a palletizing station; an input end of a sorting device (42) is provided at the output end of the incoming conveyor belt (43), and an outgoing conveyor belt (44) is provided at the output end of the incoming conveyor belt (43); a rectangular carrier fixture (45) for carrying 3D materials; the carrier fixture (45) has an inspection process slot (46); a side push rod part (47) is provided at the output end of the incoming conveyor belt (43); the side push rod part (47) includes a side pusher (48); a front baffle (51) is provided in front of the side pusher (48) and a rear baffle (49) is provided at the rear. The front baffle (51) and the rear baffle (49) form a stepped structure and form a side push opening (50). The vehicle tooling (45) is transferred unidirectionally from the sorting device (42) to the delivery conveyor (44). In the sorting device (42), an inclined swing base (52) is provided, and the support platform (53) rotates on the inclined swing base (52) via the XX rotating shaft; The conveying direction of the vehicle tooling (45) on the loading platform (53) is oblique to the center line of the XX rotating shaft; The loading platform (53) has a platform input station at point A and a platform output station at point B at the conveying inlet and outlet, respectively; Ventilation holes (55) are distributed on the support platform (53) to achieve negative pressure adsorption and positive pressure blowing. Along the YY direction perpendicular to XX, a swing guide groove A (56) and an oblique process opening (57) are provided on the support platform (53). An inclined station sensor (58) and a positioning horizontal station sensor (59) located on both sides of the XX rotating shaft are respectively provided below the support platform (53). A support part (60) is provided above the support platform (53). A swing hinge seat (62) is located below the support part (60). The swing hinge has an intermediate hinge frame (61) and an auxiliary spring (63) elastically connected; a pitch drive motor (64) is inverted on the support (60), a pitch drive frame (65) is connected to the lower end of the pitch drive motor (64), a pitch drive shaft shoulder (66) is connected to the lower end of the pitch drive frame (65), a swing guide groove B (68) along the YY direction is provided on the intermediate hinge frame (61), and the pitch drive shaft shoulder (66) is slidably provided in the swing guide groove B (68) along the YY direction; A conical contact rotator (67) is provided on both sides of the pitch drive frame (65) C on the intermediate hinge frame (61) for positioning contact with the adjacent sides of the carrier tooling (45).

2. The supporting system for the 3D printing device according to claim 1, characterized in that... A hinged driven connection part (69) is provided on the intermediate hinged frame (61). A lower connecting rod (70) is hinged to the lower end of the hinged driven connection part (69). A mating spring pad (71) is provided on the lower connecting rod (70) above and below, for contacting the upper and lower surfaces of the swing guide groove A (56) of the support platform (53).

3. A 3D printing auxiliary process, characterized in that... The system of the 3D printing device described in claim 2 is used; the 3D printing auxiliary process includes the following steps: the carrier changing unit (39) moves the carrier tool (45) in one direction between the printing platform (13) and the delivery conveyor belt (44); When the unloaded vehicle tooling (45) is transferred unidirectionally from the delivery conveyor belt (44) to the vehicle changing unit (39), S1, the carrier tool (45) is conveyed from the feed conveyor belt (43) to the sorting device (42). S2, the vehicle tool (45) is positioned by pitching through the sorting device (42); S3, the carrier tool (45) is transferred unidirectionally from the sorting device (42) to the delivery conveyor belt (44). In S2, S2.1, the lateral push rod (47) retracts, causing the lateral push opening (50) to face the output end of the conveyor belt (43) and be blocked by the rear baffle (49). At this time, the support platform (53) is in a horizontal state and receives the carrier fixture (45). S2.2, the lateral pusher (48) moves the carrier fixture (45) to the side forward. The pitch drive motor (64) drives the pitch drive shaft shoulder (66) to slide in the swing guide groove B (68) along the YY direction through the pitch drive frame (65), so as to realize the swing of the intermediate hinge frame (61), thereby driving the docking through the hinge driven connection part (69). The spring pad (71) and the lifting platform (53) are raised. At the same time, the conical contact rotating body (67) descends to the inclined process opening (57), and the lifting platform (53) becomes tilted. S2.3, the conical contact rotating body (67) rotates in opposite directions and contacts the side wall adjacent to the carrier fixture (45) and rotates to adjust and position itself. S2.4, the pitch drive motor (64) drives the lifting platform (53) to return to the horizontal state, and the conical contact rotating body (67) rises to reset. S2.5, the lateral push rod (47) moves forward and enters the lifting platform (53), and pushes out the carrier fixture (45).

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