Additive manufacturing device and thermal management method thereof

Abstract

The invention discloses an additive manufacturing device and a thermal management method thereof. The device comprises a melt extrusion module and an airflow management module. The airflow management module is mounted outside the melt extrusion module and is used for performing graded management and repeated utilization on cooling airflow of the melt extrusion module so as to improve the temperature control precision of the melt extrusion module; the melt extrusion module is used for achieving heating melting and extrusion of materials, and the airflow management module is used for cooling key parts of the melt extrusion module and guiding cooled airflow carrying heat to a forming area so as to regulate and control the material cooling process of the forming area. Through cooperation of the airflow management module and the melt extrusion module, airflow used for cooling the feeding driving motor, the melt extrusion mechanism and a workpiece is cooperatively managed and utilized in a graded mode. And meanwhile, the effects that the temperature gradient of a forming area is reduced, the warping risk is reduced, closed-loop control over the temperature of a feeding port is achieved, the additive manufacturing device is compact in design, and energy is saved are achieved.

Description

Technical Field

[0001] This invention relates to the technical field of additive manufacturing, and more specifically to an additive manufacturing apparatus and its thermal management method. Background Technology

[0002] Existing additive manufacturing equipment generally consists of a hopper, barrel, printing nozzle, and hot end. The material enters the barrel from the feed end and is pushed into the lower section of the barrel by the feed drive motor. The lower section of the barrel is connected to a heating device, which can heat up the solid material to turn it into a molten state. Under the pressure of the unmelted material, the molten material is extruded from the printing nozzle. However, existing additive manufacturing equipment still suffers from the following problems: First, to achieve uniform heating and softening of the material inside the barrel, a large barrel volume is often required to gradually soften and extrude the material. This large barrel structure encroaches on the printing volume of the equipment, limiting the promotion and application of additive manufacturing equipment. Conversely, in smaller barrel structures, the internal material is difficult to heat rapidly. To achieve efficient and uniform melting, the middle and lower parts of the barrel typically require higher temperatures. However, if the temperature is too high, the material in the upper hopper and feed end of the barrel will melt prematurely, forming clumps that prevent feeding and cause stalling. Second, due to the direct connection of the drive motor, a large amount of heat from the screw is conducted to the motor through the motor shaft, leading to motor overheating and step loss. Furthermore, because the cooling fan directly draws cooler air from the outside and blows it onto the printing area for cooling, uneven cooling can cause deformation and warping when printing high-temperature materials. The traditional solution is to add one or two cooling fans to the drive motor and hopper, and provide a heating device in the printing space. However, this method not only consumes a lot of power but also significantly increases weight and size. Therefore, developing an efficient cooling technology to solve the above problems has become an urgent challenge. Summary of the Invention

[0003] The main objective of this invention is to overcome the shortcomings and deficiencies of the prior art and to provide an additive manufacturing apparatus and its thermal management method.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] In a first aspect, the present invention provides an additive manufacturing apparatus, including a melt extrusion module and an airflow management module; the airflow management module is installed outside the melt extrusion module and is used to classify and reuse the cooling airflow of the melt extrusion module to improve the temperature control accuracy of the melt extrusion module and achieve low-stress cooling of the forming area; the melt extrusion module is used to realize the heating, melting and extrusion of materials, and the airflow management module is used to cool the key components of the melt extrusion module and guide the cooled airflow carrying heat to the forming area to regulate the material cooling process in the forming area.

[0006] As a preferred technical solution, the melt extrusion module includes an extruder barrel, a heating element, a temperature detection component, a feeding component, and a mounting carrier; the heating element is installed at the discharge end of the extruder barrel and is used to heat the discharge end of the extruder barrel; the temperature detection component cooperates with the extruder barrel and is used to detect the temperature of different areas of the extruder barrel, providing data support for temperature control; the feeding component is connected to the extruder barrel and is used to transport materials into the extruder barrel; both the extruder barrel and the feeding component are fixed on the mounting carrier.

[0007] As a preferred technical solution, the temperature detection component includes a hot-end temperature sensor and a feed-end temperature sensor; the hot-end temperature sensor is installed at the discharge end of the extruder barrel to detect the temperature at the discharge end of the extruder barrel, and works with the heating element to achieve closed-loop temperature control at the discharge end of the extruder barrel; the feed-end temperature sensor is installed at the feed end of the extruder barrel to detect the temperature at the feed end of the extruder barrel, and provides a basis for cooling and regulation of the feed end.

[0008] The feeding assembly includes a feeding drive motor and a feeding device; the feeding drive motor is connected to the feeding device, and the feeding drive motor drives the feeding device to move, so as to feed the material into the extruder barrel, and after the material enters the extruder barrel and is heated and softened, the material is pushed out; both the feeding drive motor and the feeding device are fixed on the mounting carrier to ensure stable transmission.

[0009] As a preferred technical solution, the extruder barrel includes an inner barrel, an outer barrel, a hopper, a hot end, and a nozzle; the hot end corresponds to the discharge end of the extruder barrel and is used to install heating elements, a hot end temperature sensor, and a nozzle; the inner barrel is connected to the hot end and is used to restrict the space of the molten material and conduct heat from the hot end; the hopper is connected to the inner barrel and is used to store material and preheat the material before it enters the inner barrel; the outer barrel surrounds the inner barrel and is connected to the hopper, and is used to suppress the temperature of the hopper, increase the temperature gradient, and keep the inner barrel warm.

[0010] As a preferred technical solution, the inner cylinder is provided with a variable cross-section structure; the variable cross-section structure is used to change the thermal conductivity of the inner cylinder in order to achieve temperature field management of the inner cylinder; specifically, in the region where a high temperature gradient needs to be formed, the cross-sectional area of ​​the inner cylinder is reduced, the thermal conductivity of the region is reduced, and the heat transfer from the high temperature region to the low temperature region is suppressed.

[0011] As a preferred technical solution, the airflow management module includes a feeding drive motor cooling mechanism, an extruder barrel feeding end cooling mechanism, and a forming zone cooling mechanism. The feeding drive motor cooling mechanism is used to cool the feeding drive motor in the melt extrusion module and guide the cooled airflow to the extruder barrel feeding end cooling mechanism. The extruder barrel feeding end cooling mechanism is used to cool the feeding end of the extruder barrel and guide the cooled airflow to the forming zone cooling mechanism. The forming zone cooling mechanism is used to guide the received airflow to the forming area to regulate the cooling process of the material within the forming area. The control of the airflow management module is achieved through the coordinated operation of the control motherboard and the PID algorithm. Specifically, the hopper temperature control fan outputs voltage through PID control: when the temperature sensor at the hopper detects that the hopper temperature is too high, the control motherboard adjusts the PID parameters according to the detection data to increase the voltage of the hopper temperature control fan and enhance the cooling effect; when the hopper temperature is low, the hopper temperature control fan maintains a lower voltage output to prevent the hopper from heating up too quickly. Through PID control, the hopper temperature fluctuation can be reduced, the temperature field inside the gradient temperature melt barrel can be kept stable, and a stable environment can be provided for material melting and extrusion.

[0012] As a preferred technical solution, the cooling mechanism of the forming area is a ring structure and is provided with multiple external air outlets and internal air ducts; the internal air ducts are used to uniformly guide the received airflow to each external air outlet; the size and arrangement of the external air outlets are designed through fluid simulation so that the airflow can be concentrated on the key positions of the forming area; the structural shapes of the feeding drive motor cooling mechanism, the extruder barrel feeding end cooling mechanism and the forming area cooling mechanism are all designed through wind field simulation to achieve precise control of the airflow direction.

[0013] As a preferred technical solution, it also includes a closed frame and a sliding module; the closed frame is used to provide a sealed printing space and support the various components of the additive manufacturing device; the sliding module cooperates with the melt extrusion module or the forming platform to drive the melt extrusion module or the forming platform to move and realize additive manufacturing operations at different positions.

[0014] Secondly, the present invention provides a thermal management method based on an additive manufacturing apparatus, comprising the following steps:

[0015] S1. Based on thermodynamic simulation, the internal thermal conductivity of the extruder barrel of the melt extrusion module is obtained, and the internal structure of the extruder barrel is designed and determined to achieve internal barrel temperature field management.

[0016] S2. Combine the internal structure of the cooling mechanism of the feed drive motor, the cooling mechanism of the extruder barrel feed end and the cooling mechanism of the forming area in the airflow management module with fluid simulation design to determine the airflow direction;

[0017] S3. Start the additive manufacturing device. The hot end of the melt extrusion module maintains the target temperature in a closed-loop control manner with the cooperation of the heating element and the hot end temperature sensor.

[0018] S4. During hot-end heating, heat is conducted upward through the inner wall of the extruder barrel of the melt extrusion module to the hopper, preheating the material in the hopper;

[0019] S5, the cooling mechanism of the feed drive motor in the airflow management module introduces outside air into the cooling mechanism of the feed drive motor.

[0020] S6. The feeding drive motor cooling mechanism is used to cool the feeding drive motor and guide the airflow after cooling the feeding drive motor to the extruder barrel feed end cooling mechanism.

[0021] S7. The extruder barrel feed end cooling mechanism is used to cool the extruder barrel feed end and guide the airflow after cooling the extruder barrel feed end to the forming zone cooling mechanism.

[0022] S8. The forming zone cooling mechanism directs the airflow from the feed end of the cooling extruder barrel to the forming zone, and adjusts the material cooling effect in the forming zone through manual and code control.

[0023] S9. Repeat steps S3 to S8 until the additive manufacturing operation is completed.

[0024] As a preferred technical solution, the extruder barrel feed end cooling mechanism works in conjunction with the feed end temperature sensor to achieve closed-loop temperature control. The output power of the extruder barrel feed end cooling mechanism is controlled by code. When the material hopper temperature is higher than the set threshold, the output power of the extruder barrel feed end cooling mechanism is increased to enhance the cooling effect; when the material hopper temperature is lower than the set threshold, the output power of the extruder barrel feed end cooling mechanism is reduced to avoid excessive temperature fluctuations. The forming zone cooling mechanism remains in a normally open state to continuously provide stable airflow to the forming zone.

[0025] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0026] 1. This invention can efficiently achieve the cooling function; the air near the drive motor takes away the heat of the motor through the feeding drive motor cooling mechanism, thereby cooling the motor; after the air enters the extruder head, it is blown towards the hopper by the extruder barrel feeding end cooling mechanism, and the airflow takes away the heat, cooling the upper part of the barrel; after cooling, the higher temperature air is guided to the printing surface below the printing nozzle through the forming area cooling mechanism, achieving the required material cooling effect.

[0027] 2. This invention can form a localized uniform temperature field to prevent deformation and warping; by guiding the high-temperature gas inside the extruder to the forming area, a high-temperature field can be formed locally, so that the printed workpiece maintains a uniform temperature and prevents warping and deformation due to uneven heating.

[0028] 3. This invention can accurately control the temperature of the hopper and implement regulation; a temperature sensor is installed on the upper part of the barrel to monitor the temperature of the upper hopper and the upper feeding section of the barrel in real time and transmit it to the control main board. The main board linearly controls the fan power, which effectively ensures that the temperature in the hopper is always kept below the melting temperature, so that the solid granules do not melt prematurely and achieve the preheating effect.

[0029] 4. This invention can make reasonable use of heat and reduce power consumption; it transfers the waste heat from the drive motor and the upper part of the extrusion head to the forming area, and at the same time, it keeps the printing space warm and heats it while discharging the waste heat, thus reducing the additional power consumption of heating the printing space. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the additive manufacturing apparatus of the present invention;

[0032] Figure 2 This is an internal schematic diagram of the additive manufacturing apparatus of the present invention;

[0033] Figure 3 This is a schematic diagram of the airflow direction of the heat circulation system of the additive manufacturing apparatus of the present invention;

[0034] Figure 4 This is a schematic diagram of the cooling mechanism of the feed drive motor and the cooling mechanism of the extruder barrel feed end of the additive manufacturing apparatus of the present invention;

[0035] Figure 5 This is a schematic diagram of the cooling mechanism in the forming area of ​​the additive manufacturing apparatus of the invention;

[0036] Figure 6 This is a cross-sectional view of the internal air duct of the cooling mechanism in the forming area of ​​the additive manufacturing apparatus of the invention.

[0037] Figure 7 It is a fluid simulation diagram of the cooling mechanism in the forming area of ​​the additive manufacturing device.

[0038] Figure 8 This is a schematic diagram of the internal structure of the barrel of the invention additive manufacturing device;

[0039] Figure 9 This is a simulation diagram of the barrel temperature field of the additive manufacturing device.

[0040] Figure 10 This is a schematic diagram of the mechanical simulation of the barrel of the additive manufacturing device.

[0041] Figure 11 This is a schematic diagram of the outer shell structure of the additive manufacturing device for the invention;

[0042] Figure 12 This is a flowchart of the thermal management method for the invention of an additive manufacturing device.

[0043] Explanation of reference numerals in the attached drawings: 1-Front outer shell; 2-Outlet fan of the outer shell; 3-Outlet air guide component; 4-Printing nozzle; 5-Drive motor; 6-Inlet air guide component; 7-Blouse temperature control fan; 8-Rear outer shell; 9-Extrusion screw; 10-Gradient temperature melting barrel. Detailed Implementation

[0044] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative effort are within the scope of protection of the present application.

[0045] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0046] like Figure 1 , Figure 2This embodiment of an additive manufacturing apparatus mainly includes a melt extrusion module, an airflow management module, a closed frame, and a sliding module. The airflow management module is installed outside the melt extrusion module and is used to manage and reuse the cooling airflow of the melt extrusion module in a graded manner to improve the temperature control accuracy of the melt extrusion module and achieve low-stress cooling in the forming area. The melt extrusion module is used to heat, melt, and extrude the material. The airflow management module is used to cool the key components of the melt extrusion module and guide the cooled airflow carrying heat to the forming area to regulate the material cooling process in the forming area. The closed frame is used to provide a sealed printing space and support the various components of the additive manufacturing apparatus. The sliding module cooperates with the melt extrusion module or the forming platform to drive the melt extrusion module or the forming platform to move and realize additive manufacturing operations at different positions.

[0047] Furthermore, the melt extrusion module enables the heating, melting, and stable extrusion of materials, specifically composed of a gradient temperature melting barrel 10, an extrusion screw 9, and a drive motor 5. The gradient temperature melting barrel 10 includes an upper, middle, and lower section. The middle section comprises an inner and outer cylinder, simultaneously enabling internal heat conduction, heat preservation, and hopper heat dissipation. The upper section is the hopper, featuring a grid-like perforated structure design, and its installation position is flush with the hopper temperature control fan 7. This perforated design effectively facilitates rapid heat dissipation from the material in the hopper, preventing premature melting. The lower section is equipped with a heating block, which integrates heating elements to provide heat for material melting. The extrusion screw 9 is located inside the gradient temperature melting barrel 10, directly engaging with the shaft of the drive motor 5 via a groove on its upper part and secured by a set screw to ensure transmission efficiency. The drive motor 5 rotates the extrusion screw 9, propelling the solid granules into the gradient temperature melting barrel 10, allowing the molten material to be extruded from the extrusion nozzle 4. The extrusion nozzle 4 is installed at the discharge port at the bottom of the gradient temperature melting barrel 10 and is connected to the heating block at the bottom of the gradient temperature melting barrel 10. The molten material is extruded through the extrusion nozzle 4 to the forming area.

[0048] Furthermore, the melt extrusion module also includes a temperature detection component, specifically two temperature sensors located in the hopper section and the heating block section, respectively. The temperature sensor in the hopper section is used to detect the temperature in the hopper in real time, while the temperature sensor in the heating block section is used to monitor the temperature of the heating block, providing data support for closed-loop temperature control.

[0049] Furthermore, such as Figure 8 As shown, the gradient temperature melting barrel 10 is the core component of gradient temperature control, including an inner barrel, an outer barrel, and a hopper; its structural design directly affects the execution effect of the thermal management method of the airflow management module, and the specific structure is as follows:

[0050] The inner cylinder is made of thermally conductive material and is connected to the heating block of the gradient temperature melting cylinder 10. On one hand, it conducts heat from the heating block upwards to the hopper, preheating the material inside and ensuring the granular material in the discharge channel is fully melted, providing a thermal basis for the hopper preheating stage in the thermal management method. On the other hand, it alters the thermal conductivity through a variable cross-section structure to create a gradient temperature field, such as... Figure 9 As shown, the specific temperature field distribution is as follows: high temperature in the lower section of the inner cylinder, medium-high temperature in the middle section, and low temperature maintained in the upper section to the silo. The variable cross-section structure reduces the cross-sectional area of ​​the inner cylinder in the area where a high temperature gradient needs to be formed, thereby reducing the heat conduction effect in that area, inhibiting the conduction of high temperature heat to the low temperature area (silo), and preventing the material in the silo from melting prematurely. It works in conjunction with the second-stage cooling in the airflow management module to maintain the stable temperature of the silo.

[0051] The outer cylinder surrounds the inner cylinder and is connected to the hopper, providing insulation for the inner cylinder and preventing direct airflow from the airflow management module from causing heat dissipation and temperature fluctuations, thus ensuring a stable temperature field within the inner cylinder during thermal management. Simultaneously, the outer cylinder receives heat input from the hopper, suppressing its temperature and further enhancing the temperature gradient before and after the variable cross-section structure of the inner cylinder. After heat is conducted upwards from the heating block through the inner cylinder, some heat dissipates outwards through the outer cylinder wall. The hollow area between the inner and outer cylinder walls effectively controls heat loss from the inner cylinder. Combined with the airflow channel, this regulates the heat exchange rate between the inner cylinder and the outside environment, achieving a comprehensive function of heat transfer, insulation, and heat dissipation, complementing the cooling effect of the airflow management module. Figure 10 As shown, the structural design of the inner and outer cylinders simultaneously meets the requirements of mechanical stability, avoiding structural deformation due to temperature changes during long-term operation and ensuring the long-term stable implementation of the thermal management method.

[0052] The hopper is located on the upper part of the gradient temperature melting barrel 10 and connected to the inner barrel. It adopts a grid-type hollow structure design and is installed at the same level as the hopper temperature control fan 7. The hollow structure facilitates the passage of the second-stage cooling airflow in the airflow management module. Under the action of the airflow driven by the hopper temperature control fan 7, it achieves rapid heat dissipation. At the same time, the heat conducted by the inner barrel can moderately preheat the material in the hopper. Under the premise of avoiding premature melting of the material, it ensures that the material can melt quickly after entering the inner barrel, improves extrusion stability, and is consistent with the goal of "preheating and cooling balance" in the thermal management method.

[0053] Furthermore, such as Figure 5 , Figure 6 , Figure 7As shown, the airflow management module can perform graded management and reuse of cooling airflow, and simultaneously implement a thermal management method. Specifically, it consists of a feeding drive motor cooling mechanism, an extruder barrel feeding end cooling mechanism, and a forming area cooling mechanism. The feeding drive motor cooling mechanism includes a cooperative structure of an inlet air guide component 6 and a hopper temperature control fan 7. The extruder barrel feeding end cooling mechanism includes a cooperative structure of a hopper temperature control fan 7 and a hopper. The forming area cooling mechanism includes a shell exhaust fan 2 and an exhaust air guide component 3, as shown... Figure 4 As shown, the structural layout of the cooling mechanism of the feed drive motor and the cooling mechanism of the extruder barrel feed end are adapted to the positional relationship between the drive motor 5 and the gradient temperature melting barrel 10, ensuring that the airflow accurately covers the area to be cooled, and that each mechanism works together to achieve the thermal management process.

[0054] like Figure 3 As shown, the airflow direction of the airflow management module is as follows: air inlet guide component – ​​material hopper temperature control fan – material hopper – outer shell exhaust fan – exhaust guide component – ​​workpiece. The airflow is drawn in from the drive motor at the top of the nozzle, enters the nozzle and cools the material hopper before being discharged to the printing area to cool the printed workpiece. This invention can simultaneously achieve cooling of the motor, cooling of the material hopper, and cooling and heat preservation of the workpiece.

[0055] Furthermore, the air inlet guide component 6 is located at the top of the extruder head, and the hopper temperature control fan 7 and the outer shell exhaust fan 2 are installed on both sides of the rear outer shell 8, with uneven heights; the air inlet guide component 6 is connected to the hopper temperature control fan 7, and the air outlet guide component 3 is connected to the outer shell exhaust fan 2; the air inlet guide component 6 and the air outlet guide component 3 are designed based on wind field simulation, and by adjusting the angle and size, precise control of the airflow direction can be achieved, laying the structural foundation for directional airflow transmission in thermal management methods.

[0056] In this embodiment, the execution flow of the thermal management method in the airflow management module is as follows:

[0057] Preliminary simulation and parameter setting: Before the thermal management method is started, the thermal conductivity of the inner cylinder of the gradient temperature melting barrel 10 is determined by thermodynamic simulation, and a variable cross-section structure is designed to achieve temperature field management; at the same time, the internal structure and installation angle of the air inlet guide component 6, the hopper temperature control fan 7, the outer shell air outlet fan 2, and the air outlet guide component 3 are designed by fluid simulation to determine the airflow direction and ensure efficient execution of subsequent airflow staged cooling.

[0058] First-stage cooling (drive motor cooling): The air inlet guide component 6 includes an air inlet and an air outlet. The airflow is powered by the hopper temperature control fan 7. The air inlet guide component 6 is directly opposite the drive motor 5. During operation, it allows the drawn-in outside air to pass through the drive motor 5 at the same time, carrying away the heat generated by the motor and keeping the temperature of the drive motor 5 below the preset range to prevent the motor from overheating and losing steps. The cooled airflow is guided by the power of the hopper temperature control fan 7 to the cooling mechanism at the feed end of the extruder barrel and enters the next stage of cooling.

[0059] Second-stage cooling (extruder barrel feed end and hopper cooling): The hopper temperature control fan 7 blows the airflow cooled in the first stage towards the grid-type hopper. The airflow flows through the hopper through the perforated structure, carrying away excess heat from the hopper. During this process, the thermal management method achieves closed-loop temperature control through the cooperation of the hopper temperature sensor and the hopper temperature control fan 7. Specifically, the hopper temperature control fan 7 outputs voltage through PID control. When the hopper temperature sensor detects that the hopper temperature is higher than the set threshold, the voltage of the hopper temperature control fan 7 increases, increasing the airflow velocity to enhance the cooling effect. When the hopper temperature is lower than the set threshold, the hopper temperature control fan 7 maintains a smaller voltage output to prevent the hopper from heating up too quickly. PID control reduces hopper temperature fluctuations and maintains a stable inner barrel temperature field. At the same time, the airflow simultaneously cools the extruder barrel feed end to prevent the feed end temperature from being too high, which could cause the material to melt prematurely and block the material. The cooled airflow is guided to the forming area cooling mechanism by the power of the outer casing exhaust fan 2.

[0060] Third-stage cooling (cooling and insulation of the forming area): The outer casing exhaust fan 2 provides auxiliary power for the airflow, guiding the hot air cooled in the second stage into the exhaust guide component 3; such as Figure 5 As shown, the air outlet guide component 3 has a ring structure, as... Figure 6 As shown in the (internal air duct cross-section diagram), it has four internal air ducts that can evenly guide airflow to seven external air outlets (five with larger areas and two with smaller areas; the five large air outlets are evenly distributed, and the two small air outlets are symmetrically distributed about the front reference plane); the size and arrangement of the air outlets were designed using fluid simulation. Figure 7 (For fluid simulation diagram), the airflow is ultimately concentrated in the forming area directly below the extrusion nozzle 4; the thermal management method in this stage controls the airflow temperature and direction, so that the hot airflow can rapidly cool the molten material extruded from the extrusion nozzle 4 to below the glass transition temperature to achieve material shaping, and provide local insulation for the forming area to avoid stress and warping of the material due to rapid cooling, thereby reducing the risk of workpiece warping; and the cooling mechanism in the forming area is kept in a constantly open state to continuously provide a stable airflow to the forming area, ensuring that the cooling and insulation effects are consistent.

[0061] Continuous regulation and cyclic execution: During the operation of the additive manufacturing device, the airflow management module continuously repeats the first to third stage cooling process. Temperature sensors at the hopper and the heating block provide real-time temperature data feedback. The thermal management method dynamically adjusts the output power of the hopper temperature control fan 7 and the heating power of the heating block by controlling the main board until additive manufacturing is completed.

[0062] Furthermore, the enclosed frame provides a sealed printing space and supports the various components of the device, including the front housing 1, the rear housing 8, the aluminum profile, the acrylic plate, and the printing platform. The aluminum profile provides frame support, the acrylic plate provides observation and enclosure, and the printing platform is located directly below the printing nozzle 4. Figure 11 As shown. Both the front outer shell 1 and the rear outer shell 8 are sheet metal parts. The front outer shell 1 is used to enclose the front end of the device, and the rear outer shell 8 serves as the core mounting carrier. The gradient temperature melting barrel 10, drive motor 5, air inlet guide component 6, hopper temperature control fan 7, outer shell air outlet fan 2, and air outlet guide component 3 are all fixed on the rear outer shell 8.

[0063] Furthermore, the sliding module is a three-axis sliding structure, including an X-axis beam, a Z-axis ball screw, a timing belt, a slider, a coupling, and a linear guide. The extruder head integrates components such as a gradient temperature melting barrel 10, a printing nozzle 4, and a drive motor 5. The extruder head is mounted on the X-axis beam and moves in the X-axis direction through the timing belt and the X-axis drive motor. The X-axis beam moves in the Y-axis direction through the timing belt and the Y-axis drive motor. The printing platform is mounted on the Z-axis ball screw, and the Z-axis drive motor is connected to the ball screw through a coupling. The rotation of the ball screw drives the printing platform to achieve vertical movement in the Z-axis direction, ultimately achieving precise printing in three-dimensional space.

[0064] Control Unit: Includes a control motherboard located in an external control cabinet, which is connected to a temperature sensor, a hopper temperature control fan 7, a heating block, and a drive motor 5. The control motherboard is used to control the hopper temperature control fan 7 to work (perform PID regulation in the thermal management method), set the heating temperature of the heating block (in conjunction with the temperature closed-loop control in the thermal management method), and control the drive motor 5 to work based on the temperature data collected by the temperature sensor, ensuring that the airflow management module and the melt extrusion module work together to ensure the effective execution of the thermal management method throughout the process.

[0065] In this embodiment, during operation, heat is conducted upwards from the heating block through the inner cylinder, ensuring the granules in the discharge channel are fully melted. The extrusion screw, driven by the motor, rotates, pushing the solid granules into the cylinder, extruding the molten material from the printing nozzle. After upward conduction, the heat dissipates outwards through the outer cylinder wall, and the hollow area between the inner and outer cylinder walls effectively controls the heat loss from the inner cylinder. Simultaneously, the airflow channel regulates the heat exchange rate between the inner cylinder and the outside environment, achieving a comprehensive function of heat transfer, insulation, and heat dissipation. During printing, a temperature sensor at the bottom of the grid-type material hopper monitors the internal temperature of the hopper in real time and transmits the data to the control mainboard. The mainboard provides PID control for the fan; when the inlet temperature is too high, the fan power increases; when the temperature is low, the fan output power decreases. A temperature sensor at the bottom of the cylinder detects the material temperature at the discharge port in real time and feeds the information back to the control mainboard. If the temperature is higher than the theoretical threshold, the control mainboard lowers the heating temperature of the heating block; if the temperature is lower than the theoretical threshold, it increases the heating temperature of the heating block.

[0066] like Figure 12 As shown, in another embodiment of this application, a thermal management method for an additive manufacturing apparatus is also provided, specifically including the following steps:

[0067] S1. Based on thermodynamic simulation, the internal thermal conductivity of the extruder barrel of the melt extrusion module is obtained, and the internal structure of the extruder barrel is designed and determined to achieve internal barrel temperature field management.

[0068] S2. Combine the internal structure of the cooling mechanism of the feed drive motor, the cooling mechanism of the extruder barrel feed end and the cooling mechanism of the forming area in the airflow management module with fluid simulation design to determine the airflow direction;

[0069] S3. During the operation of the additive manufacturing device, the hot end of the melt extrusion module is heated in a closed loop through heating elements and a hot end temperature sensor.

[0070] S4. During hot-end heating, heat is conducted upward through the inner wall of the extruder barrel of the melt extrusion module to the hopper, preheating the material in the hopper;

[0071] S5, the cooling mechanism of the feed drive motor in the airflow management module introduces outside air into the cooling mechanism of the feed drive motor.

[0072] S6. The feeding drive motor cooling mechanism is used to cool the feeding drive motor and guide the airflow after cooling the feeding drive motor to the extruder barrel feed end cooling mechanism.

[0073] S7. The extruder barrel feed end cooling mechanism is used to cool the extruder barrel feed end and guide the airflow after cooling the extruder barrel feed end to the forming zone cooling mechanism.

[0074] S8. The forming zone cooling mechanism directs the airflow from the feed end of the cooling extruder barrel to the forming zone, and adjusts the material cooling effect in the forming zone through manual and code control.

[0075] S9. Repeat steps S3 to S8 until additive manufacturing is complete;

[0076] In this embodiment, the barrel and screw are manufactured using additive manufacturing, the front and rear housings are manufactured using sheet metal methods, the air inlet and outlet guide components are manufactured using additive manufacturing, and finally the parts are assembled.

[0077] In this embodiment, the designed air circulation system is assembled with the barrel, extrusion screw, heating block, printing nozzle, main board, temperature sensor, etc., to finally obtain the molten pellet manufacturing device.

[0078] It should also be noted that, in this specification, terms such as "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0079] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An additive manufacturing apparatus, characterized in that, It includes a melt extrusion module and an airflow management module; the airflow management module is installed outside the melt extrusion module and is used to classify and reuse the cooling airflow of the melt extrusion module to improve the temperature control accuracy of the melt extrusion module and achieve low-stress cooling of the forming area; the melt extrusion module is used to realize the heating, melting and extrusion of materials, and the airflow management module is used to cool the key components of the melt extrusion module and guide the cooled airflow carrying heat to the forming area to regulate the material cooling process in the forming area.

2. The additive manufacturing apparatus according to claim 1, characterized in that, The melt extrusion module includes an extruder barrel, a heating element, a temperature detection component, a feeding component, and a mounting carrier. The heating element is installed at the discharge end of the extruder barrel to heat the discharge end. The temperature detection component works with the extruder barrel to detect the temperature in different areas of the extruder barrel, providing data support for temperature control. The feeding component is connected to the extruder barrel to convey material into the extruder barrel. Both the extruder barrel and the feeding component are fixed on the mounting carrier.

3. The additive manufacturing apparatus according to claim 2, characterized in that, The temperature detection component includes a hot-end temperature sensor and a feed-end temperature sensor. The hot-end temperature sensor is installed at the discharge end of the extruder barrel to detect the temperature at the discharge end of the extruder barrel, and works with the heating element to achieve closed-loop temperature control at the discharge end of the extruder barrel. The feed-end temperature sensor is installed at the feed end of the extruder barrel to detect the temperature at the feed end of the extruder barrel, and provides a basis for cooling and regulation of the feed end. The feeding assembly includes a feeding drive motor and a feeding device; the feeding drive motor is connected to the feeding device, and the feeding drive motor drives the feeding device to move, so as to feed the material into the extruder barrel, and after the material enters the extruder barrel and is heated and softened, the material is pushed out; both the feeding drive motor and the feeding device are fixed on the mounting carrier to ensure stable transmission.

4. The additive manufacturing apparatus according to claim 2, characterized in that, The extruder barrel includes an inner barrel, an outer barrel, a hopper, a hot end, and a nozzle; the hot end corresponds to the discharge end of the extruder barrel and is used to install heating elements, a hot end temperature sensor, and a nozzle; the inner barrel is connected to the hot end and is used to restrict the space of the molten material and conduct heat from the hot end; the hopper is connected to the inner barrel and is used to store material and preheat the material before it enters the inner barrel; the outer barrel surrounds the inner barrel and is connected to the hopper, and is used to suppress the temperature of the hopper, increase the temperature gradient, and keep the inner barrel warm.

5. The additive manufacturing apparatus according to claim 4, characterized in that, The inner cylinder is provided with a variable cross-section structure; the variable cross-section structure is used to change the thermal conductivity of the inner cylinder in order to achieve temperature field management of the inner cylinder; specifically, in areas where a high temperature gradient needs to be formed, the cross-sectional area of ​​the inner cylinder is reduced to reduce the thermal conductivity of the area and suppress the conduction of heat from the high temperature area to the low temperature area.

6. The additive manufacturing apparatus according to claim 1, characterized in that, The airflow management module includes a feeding drive motor cooling mechanism, an extruder barrel feeding end cooling mechanism, and a forming zone cooling mechanism. The feeding drive motor cooling mechanism cools the feeding drive motor in the melt extrusion module and directs the cooled airflow to the extruder barrel feeding end cooling mechanism. The extruder barrel feeding end cooling mechanism cools the feeding end of the extruder barrel and directs the cooled airflow to the forming zone cooling mechanism. The forming zone cooling mechanism directs the received airflow to the forming area to regulate the cooling process of the material within the forming area. The control of the airflow management module is achieved through a combination of a control motherboard and a PID algorithm. Specifically, the hopper temperature control fan outputs voltage via PID control: when the temperature sensor at the hopper detects that the hopper temperature is too high, the control motherboard adjusts the PID parameters based on the detection data, increasing the voltage of the hopper temperature control fan to enhance the cooling effect; when the hopper temperature is low, the hopper temperature control fan maintains a lower voltage output to prevent the hopper from heating up too quickly. PID control reduces hopper temperature fluctuations, maintains a stable temperature field within the gradient temperature melt extrusion barrel, and provides a stable environment for material melting and extrusion.

7. The additive manufacturing apparatus according to claim 6, characterized in that, The cooling mechanism of the forming area is a ring structure with multiple external air outlets and internal air ducts. The internal air ducts are used to uniformly guide the received airflow to each external air outlet. The size and arrangement of the external air outlets are designed through fluid simulation so that the airflow can be concentrated on the key positions of the forming area. The structural shapes of the cooling mechanism of the feeding drive motor, the cooling mechanism of the extruder barrel feeding end, and the cooling mechanism of the forming area are all designed through wind field simulation to achieve precise control of the airflow direction.

8. The additive manufacturing apparatus according to claim 1, characterized in that, It also includes a closed frame and a sliding module; the closed frame is used to provide a sealed printing space and support the various components of the additive manufacturing device; the sliding module cooperates with the melt extrusion module or the forming platform to drive the melt extrusion module or the forming platform to move and realize additive manufacturing operations at different positions.

9. A thermal management method based on the additive manufacturing apparatus according to any one of claims 1-8, characterized in that, Includes the following steps: S1. Based on thermodynamic simulation, the internal thermal conductivity of the extruder barrel of the melt extrusion module is obtained, and the internal structure of the extruder barrel is designed and determined to achieve internal barrel temperature field management. S2. Combine the internal structure of the cooling mechanism of the feed drive motor, the cooling mechanism of the extruder barrel feed end and the cooling mechanism of the forming area in the airflow management module with fluid simulation design to determine the airflow direction; S3. Start the additive manufacturing device. The hot end of the melt extrusion module maintains the target temperature in a closed-loop control manner with the cooperation of the heating element and the hot end temperature sensor. S4. During hot-end heating, heat is conducted upward through the inner wall of the extruder barrel of the melt extrusion module to the hopper, preheating the material in the hopper; S5, the cooling mechanism of the feed drive motor in the airflow management module introduces outside air into the cooling mechanism of the feed drive motor. S6. The feeding drive motor cooling mechanism is used to cool the feeding drive motor and guide the airflow after cooling the feeding drive motor to the extruder barrel feed end cooling mechanism. S7. The extruder barrel feed end cooling mechanism is used to cool the extruder barrel feed end and guide the airflow after cooling the extruder barrel feed end to the forming zone cooling mechanism. S8. The forming zone cooling mechanism directs the airflow from the feed end of the cooling extruder barrel to the forming zone, and adjusts the material cooling effect in the forming zone through manual and code control. S9. Repeat steps S3 to S8 until the additive manufacturing operation is completed.

10. The thermal management method according to claim 9, characterized in that, The extruder barrel feed end cooling mechanism works in conjunction with the feed end temperature sensor to achieve closed-loop temperature control. The output power of the extruder barrel feed end cooling mechanism is controlled by code. When the material hopper temperature is higher than the set threshold, the output power of the extruder barrel feed end cooling mechanism is increased to enhance the cooling effect. When the material hopper temperature is lower than the set threshold, the output power of the extruder barrel feed end cooling mechanism is reduced to avoid excessive temperature fluctuations. The forming zone cooling mechanism remains in a normally open state to continuously provide a stable airflow to the forming zone.

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