Cooling assembly, printhead and 3D printing device

Abstract

The application relates to the field of 3D printing, aims to solve the problem that the material extrusion speed and the material extrusion accuracy of a known FDM printing device cannot meet the high-speed printing requirement, and provides a cooling assembly, a printing head and a 3D printing device. The cooling assembly comprises a first cooling part and a second cooling part. The first cooling part comprises a first cooling channel for cooling medium flow, and the first cooling channel is thermally coupled with an extrusion motor of the printing head. The second cooling part comprises a second cooling channel for cooling medium flow, and the second cooling part is thermally coupled with a throat pipe of the printing head. The application has the beneficial effect that the material can be prevented from being softened in advance, the accurate and powerful delivery of the material can be ensured, the high extrusion speed requirement of high-speed printing can be met, and the accurate control of the material extrusion amount can still be ensured.

Description

Technical Field

[0001] This application relates to the field of 3D printing, and more specifically, to cooling components, print heads, and 3D printing equipment. Background Technology

[0002] 3D printing equipment based on fused deposition modeling (FDM) technology is commonly used for printing thermoplastic materials such as PLA, ABS, TPU, and PETG.

[0003] In known technologies, 3D printing equipment based on FDM technology has difficulty meeting the requirements of increasingly higher printing speeds in terms of the accuracy of material extrusion speed and extrusion volume. Summary of the Invention

[0004] This application provides a cooling assembly, a print head, and a 3D printing device to address the problem that the extrusion speed and extrusion volume accuracy of known FDM printing equipment are insufficient to meet the requirements of high-speed printing.

[0005] In a first aspect, this application provides a cooling assembly for a print head of a 3D printing device. The cooling assembly includes a first cooling section and a second cooling section. The first cooling section includes a first cooling channel for the flow of a cooling medium, and the first cooling channel is thermally coupled to the extrusion motor of the print head. The second cooling section includes a second cooling channel for the flow of a cooling medium, and the second cooling section is thermally coupled to the throat of the print head.

[0006] The cooling assembly in this application cools the throat and extrusion motor through a first cooling section and a second cooling section. Cooling the extrusion motor reduces the impact of heat generated during its operation on the consumables at the extrusion gear assembly. Cooling the throat reduces the heat conducted upstream from the nozzle assembly to the consumables, thus minimizing the impact of the nozzle assembly's heat on the consumables at the upstream extrusion gear assembly. Therefore, by cooling the extrusion motor and throat, heat that might be transferred to the consumables at the extrusion gear assembly can be removed, preventing premature softening of the consumables at the extrusion gear assembly. This ensures precise and powerful delivery of the consumables by the extrusion gear assembly, making it suitable for the high extrusion speed requirements of high-speed extrusion scenarios while still guaranteeing precise control of the consumable extrusion volume.

[0007] In one possible implementation, the first cooling section further includes a first inlet and a first outlet communicating with a first cooling channel, the first cooling channel being configured to at least partially surround the outer periphery of the extrusion motor, the cooling medium entering the first cooling channel from the first inlet and flowing out from the first outlet.

[0008] In one possible implementation, the second cooling section includes a cooling block, a second cooling channel is disposed inside the cooling block, the cooling block includes a first pipe for accommodating a throat, and the second cooling channel is configured to at least partially surround the outer periphery of the first pipe.

[0009] The second cooling section also includes a second inlet and a second outlet that connect to the second cooling channel. The cooling medium enters the second cooling channel through the second inlet and flows out through the second outlet.

[0010] In one possible implementation, the first cooling section and the second cooling section are interconnected, and the cooling assembly further includes a connecting channel connecting the first cooling section and the second cooling section. The cooling medium is configured to enter the second cooling channel from the second inlet, flow out from the second outlet, and enter the first cooling channel from the first inlet through the connecting channel, and flow out from the first outlet.

[0011] In one possible implementation, the cooling block further includes a second pipe communicating with the first pipe, the second pipe having a retaining element for abutting the throat.

[0012] In one possible implementation, the cooling assembly further includes a cooling medium container, a fluid pump, and a radiator; the cooling medium container, the fluid pump, the second cooling section, the first cooling section, and the radiator are connected in sequence, and the cooling medium container is also connected to the radiator to form a circulation.

[0013] In one possible implementation, the cooling medium is a coolant or a cooling gas.

[0014] Secondly, this application provides a printhead including an extrusion assembly, a nozzle assembly, and the aforementioned cooling assembly; the extrusion assembly includes an extrusion motor and an extrusion gear set, the extrusion motor being connected to and driving the extrusion gear set to rotate; the nozzle assembly includes a heating element, a throat, and a nozzle, the heating element being thermally coupled to the nozzle, and the throat being configured to connect the nozzle and the extrusion assembly.

[0015] In one possible implementation, the nozzle includes a spiral flow channel tube and a discharge nozzle, with one end of the spiral flow channel tube connected to a throat and the other end connected to the discharge nozzle; the heating element is a heating wire that extends spirally along the spiral flow channel tube and is thermally coupled to the spiral flow channel tube.

[0016] In one possible implementation, the nozzle further includes a plurality of support blocks arranged sequentially along the discharge direction of the nozzle, the plurality of support blocks being fixedly connected to each other and to the second cooling section by connectors; the spiral flow channel tube is supported on the plurality of support blocks; each support block is provided with a temperature sensor, the temperature sensor corresponding to a different position of the spiral flow channel tube, for detecting the temperature at different positions of the spiral flow channel tube, the temperature being used to control the flow rate of the cooling medium and / or the heating temperature of the heating element.

[0017] Thirdly, this application provides a 3D printing device, including the aforementioned cooling component or the aforementioned print head. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of the 3D printing equipment according to an embodiment of this application;

[0020] Figure 2 This is a schematic diagram of the printhead structure according to an embodiment of this application;

[0021] Figure 3 for Figure 2 Exploded view of the printhead;

[0022] Figure 4 for Figure 2 Another exploded view of the printhead;

[0023] Figure 5 for Figure 2 A cross-sectional view of the printhead;

[0024] Figure 6 This is a schematic diagram of the structure of the extrusion motor and extrusion gear assembly according to an embodiment of this application;

[0025] Figure 7 for Figure 6 Exploded view of the extrusion motor and extrusion gear assembly;

[0026] Figure 8 This is a schematic diagram of the structure of the liquid coolant block according to an embodiment of this application;

[0027] Figure 9 This is a three-dimensional schematic diagram of the connection structure between the liquid cooling block and another nozzle assembly according to an embodiment of this application.

[0028] Figure 10 for Figure 9 The front view;

[0029] Figure 11 This is a block diagram of the cooling cycle of the printhead in an embodiment of this application;

[0030] Figure 12 The temperature cloud map of the print head of the 3D printing device used in Comparative Example 1 during printing;

[0031] Figure 13The temperature cloud map of the print head of the 3D printing device according to an embodiment of this application during printing.

[0032] Explanation of key component symbols:

[0033] 3D printing equipment 100

[0034] Printing Platform 101

[0035] Printhead 10

[0036] Extrusion component 11

[0037] Cooling component 12

[0038] Extrusion motor 13

[0039] Extrusion gear assembly 14

[0040] Nozzle assembly 15, 15a

[0041] Nozzle 16a

[0042] Heating element 16b

[0043] Heat insulation sleeve 17 18 trachea 19 shell 20 brackets Interlayer cooling fan 21 Backplate 22 Back frame 23 Connector block 24 First Cooling Section 25 Second Cooling Section 26 Cooling ring 27 Cooling block 28 Box shell 29 First Pipeline 30 Connection Channel 31 Cooling medium container 33 Fluid pump 34 35 radiator Radiator fan 36 Second Pipeline 37 Two-stage reduction gear 38 Driven gear 39 Output gear 40 Consumables Conveyor Wheel 41 Gearbox bottom shell 42 Gearbox front housing 43 Gearbox base plate 44 Gearbox 45 Connecting screw 46 Quick Claw 47 Gear shifter 48 End nozzle 52 Spiral flow channel tube 53 Heating wire 54 Support frame 55 First support block 56 Second support block 57 Connector 58 Temperature sensor 59 Third support block 60 First Exit K1 First Import K2 Second Exit K3 Second import K4 Consumables Import K5 Consumables Export K6 Ventilation hole K7 Via K8

[0044] Lateral opening K9

[0045] Set screw hole K10

[0046] Consumables Supply Port K11

[0047] Receiving cavity Q1

[0048] Consumables Channel S1

[0049] First cooling channel T1

[0050] Second cooling channel T2 Detailed Implementation

[0051] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0052] It should be noted that when a component is said to be "fixed to" another component, it can be directly on the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. When a component is said to be "set on" another component, it can be directly set on the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0053] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "or / and" as used herein includes any and all combinations of one or more of the associated listed items.

[0054] Some embodiments of this application are described in detail. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0055] Example

[0056] See Figure 1 This embodiment provides a 3D printing device 100, which can specifically be a 3D printing device based on FDM technology.

[0057] The 3D printing equipment 100 includes a printing platform 101, a print head 10, and displacement components in the X, Y, and Z directions. The print head 10 and the printing platform 101 move relative to each other in a controlled manner under the drive of the displacement components, thereby printing a part on the printing platform 101. The printing platform 101 can be displaced in the Y direction, and the print head 10 can be displaced in the X and Z directions.

[0058] See also Figures 2-5 In this embodiment, the printhead 10 includes an extrusion assembly 11, a nozzle assembly 15, and a cooling assembly 12. The extrusion assembly 11 includes an extrusion motor 13 and an extrusion gear assembly 14.

[0059] The extrusion motor 13 is connected to the extrusion gear assembly 14, which drives the extrusion gear assembly 14 to rotate and transport the filament. The nozzle assembly 15 receives the filament, heats and melts it, and forces it to be extruded onto the printing platform 101 to achieve printing. The cooling assembly 12 cools the extrusion assembly and the nozzle assembly to ensure that the 3D printing equipment 100 is well adapted to the high-speed extrusion and precise transport of the filament.

[0060] See also Figure 6 and Figure 7 In this embodiment, the extrusion motor 13 serves as the power source for the extrusion of consumables. The extrusion motor 13 can be a stepper motor, a brushless DC motor, or other suitable types of motors.

[0061] The extrusion gear assembly 14 includes a two-stage reduction gear 38 and a driven gear 39. The output shaft of the extrusion motor 13 is connected to the input end of the two-stage reduction gear 38. The driven gear 39 meshes with the output gear 40 of the two-stage reduction gear 38, and the number of teeth is equal to ensure that they rotate at the same speed. The driven gear 39 and the output gear 40 are each connected to a consumable conveying wheel 41. The two consumable conveying wheels 41 are spaced apart from each other, and the gap between the two consumable conveying wheels 41 allows consumables to pass through. During conveying, the two consumable conveying wheels 41 clamp the consumables in the middle, and the outer circumferential surfaces of the two consumable conveying wheels 41 are in contact with the consumables. When the consumable conveying wheels 41 rotate, they will drive the consumables toward the nozzle assembly 15 through friction, thereby realizing the transport of consumables.

[0062] In other embodiments, the two-stage reduction gear 38 can be replaced by a single-stage reduction gear, a three-stage reduction gear, or other types of reduction gears, without limitation. The reduction gear can increase the output torque.

[0063] In this embodiment, the extrusion gear assembly 14 can be disposed within the gearbox 45 formed by the gearbox bottom shell 42, the gearbox front shell 43, and the gearbox base plate 44. The gearbox 45 can be connected to the extrusion motor 13 via connecting screws 46, thus forming an integrated structure of the extrusion motor 13 and the gearbox 45. In this embodiment, the extrusion motor 13 is connected to the horizontal side of the extrusion gear assembly 14. Here, "horizontal" refers to the vertical downward conveying of consumables, with the corresponding extrusion motor 13 positioned laterally (i.e., horizontally) on one side of the extrusion gear assembly 14.

[0064] Optionally, a consumable supply port K11 can be provided at the consumable input end of the corresponding consumable conveying wheel 41. The consumable supply port K11 can be provided by a quick-release chuck 47 that fits on the gearbox bottom shell 42. In use, consumables can enter through the consumable supply port K11 on the quick-release chuck 47 and then be output from the other side by the consumable conveying wheel 41.

[0065] Optionally, the extrusion gear assembly 14 also includes a gear shift lever 48 for adjusting the gap between the driven gear 39 and the output gear 40 to engage or disengage the consumable.

[0066] In this embodiment, the torque T of the extrusion motor 13 is T = K * I, where I is the output current and K is the torque constant. That is, the torque T of the extrusion motor 13 is proportional to the output current I.

[0067] The torque of the extrusion motor 13 increases after passing through the extrusion gear assembly 14, and the final output force after passing through the extrusion gear assembly 14 is F = (T*i*μ) / r, where i is the reduction ratio of the two-stage reduction gears 38 of the extrusion gear assembly 14, μ is the transmission efficiency of the extrusion gear assembly 14, and r is the lever arm.

[0068] When extruding consumables, it is necessary to ensure that the output force F is greater than the force Ftot required by the consumables during the extrusion process at a given flow rate, i.e., F>Ftot.

[0069] As FDM printing equipment develops towards higher speeds, the required filament extrusion speed is increasing, which in turn increases the required force Ftot, and consequently, the required force F is also increasing.

[0070] To increase the force F, a common method is to increase the output current I of the extrusion motor 13. However, the commonly used extrusion motor 13 is a stepper motor, which, due to structural and algorithmic limitations, generates significant heat when the output current I is large. In this embodiment, the heat generated by the extrusion motor 13 is transferred to the extrusion gear assembly 14, and then to the filament at the extrusion gear assembly 14, causing the filament to soften prematurely. The prematurely softened filament at the extrusion gear assembly 14 cannot reliably withstand the conveying force transmitted by the filament conveying wheel 41, limiting the increase in filament extrusion speed. Furthermore, after the filament softens, its cross-section cannot maintain consistency along its length, making it impossible to accurately measure and control the amount of filament conveyed by the filament conveying wheel 41. Consequently, it is difficult to accurately output the required amount of filament as needed, affecting print quality.

[0071] See again Figures 2-5 The printhead assembly 15 includes a nozzle 16a, a heating element 16b, a heat insulation sleeve 17, and a throat 18. The throat 18 receives the filament conveyed by the extrusion gear assembly 14. The received filament passes through the nozzle 16a and is heated and melted by the heating element 16b before being extruded onto the printing platform 101 (see [reference needed]). Figure 1 The material is cooled and formed on the surface. A heat insulation sleeve 17 is fitted around the nozzle 16a and the heating element 16b to reduce heat loss at the nozzle 16a and ensure that the consumable at the nozzle 16a reaches the required heating temperature. In this embodiment, the throat 18 can be made of heat insulation material to reduce the conduction of heat from the nozzle 16a to the upstream consumable.

[0072] The cooling assembly 12 provided in this embodiment includes a first cooling section 25 and a second cooling section 26. The first cooling section includes a first cooling channel for the flow of a cooling medium, and the second cooling section includes a second cooling channel for the flow of a cooling medium. The first cooling channel is thermally coupled to the extrusion motor 13 to cool the extrusion motor 13. The second cooling channel is thermally coupled to the throat 18 to cool the throat 18.

[0073] The cooling medium can be a gaseous refrigerant, a liquid refrigerant, or a solid refrigerant. A gaseous refrigerant can be air, etc.; a liquid refrigerant can be water, brine, etc.; and a solid refrigerant can be ice, dry ice, etc.

[0074] The nozzle assembly 15 and the extrusion motor 13 are cooled by the first cooling section 25 and the second cooling section 26. Cooling the extrusion motor 13 reduces the impact of the heat generated during its operation on the consumable at the extrusion gear assembly 14. Cooling the throat 18 reduces the heat transferred upstream from the nozzle assembly 15 to the consumable via the throat 18, thus reducing the impact of the heat from the nozzle assembly 15 on the consumable at the upstream extrusion gear assembly 14. Therefore, cooling the extrusion motor 13 and the throat 18 removes heat that might be transferred to the consumable at the extrusion gear assembly 14, preventing premature softening of the consumable at the extrusion gear assembly 14. This ensures precise and powerful delivery of the consumable by the extrusion gear assembly 14, suitable for the high extrusion speed requirements of high-speed extrusion scenarios, while still maintaining precise control of the consumable extrusion volume.

[0075] In this embodiment, the first cooling section 25 includes a cooling ring 27, and the second cooling section 26 includes a cooling block 28. The cooling ring 27 at least partially surrounds the outer periphery of the extrusion motor 13 and is thermally coupled to the extrusion motor 13. The connection method between the cooling ring 27 and the extrusion motor 13 can be configured as needed, such as by using screws, and is not limited here. The contact surface between the cooling ring 27 and the extrusion motor 13 can be filled with thermally conductive pads, thermally conductive silicone grease, etc., to reduce contact thermal resistance. The heat generated by iron loss, copper loss, etc. during the operation of the extrusion motor 13 can be conducted to the cooling ring 27 and then carried away by the cooling medium (such as water) flowing inside the cooling ring 27. The interior of the cooling ring 27 can be hollow or have internal flow channels to increase heat exchange capacity.

[0076] A cooling block 28 is connected between the throat 18 and the extrusion gear assembly 14 to prevent heat transfer from the throat 18 to the extrusion gear assembly 14. A second cooling channel is located inside the cooling block. The cooling block 28 includes a housing 29 and a first pipe 30; the housing 29 defines a receiving cavity Q1 for containing coolant and serves as the second cooling channel. The first pipe 30 is located within the receiving cavity Q1 and defines a consumable channel S1. The housing 29 also has a consumable inlet K5 and a consumable outlet K6, respectively connecting the two ends of the consumable channel S1. The consumable inlet K5 is used to receive consumables supplied by the extrusion gear assembly 14 driven by the extrusion motor 13, and the consumable outlet K6 is used to accommodate and connect the throat 18 to supply consumables to the nozzle assembly 15. The second cooling channel at least partially surrounds the outer periphery of the first pipe to achieve cooling of the first pipe.

[0077] In this embodiment, optionally, the first cooling section and the second cooling section are interconnected, that is, the first cooling channel and the second cooling channel are interconnected, and the cooling medium in them can flow in series or in parallel.

[0078] For example, the cooling assembly 12 also includes a connecting channel 31 that connects the receiving cavity Q1 and the cooling ring 27 to achieve centralized combined cooling of the cooling ring 27 and the cooling block 28. By placing the cooling block 28 between the throat 18 and the extrusion gear assembly 14, heat from the nozzle assembly 15, which requires high-temperature heating, can be prevented from being conducted to the extrusion gear assembly 14, thus preventing the consumables at the extrusion gear assembly 14 from softening prematurely due to heat, which would affect the efficiency and accuracy of the consumables conveyed by the extrusion gear assembly 14. At the same time, the cooling of the cooling block 28 can also remove heat from the extrusion gear assembly 14 and the consumables at the extrusion gear assembly 14, preventing the consumables at the extrusion gear assembly 14 from softening prematurely and affecting the extrusion speed and extrusion quantity accuracy. Optionally, the cooling block 28 can be made of copper or aluminum alloy.

[0079] The cooling ring 27 has a first outlet K1 and a first inlet K2. The casing 29 has a second outlet K3 and a second inlet K4 that are respectively connected to the second cooling channel T2. The connecting channel 31 connects the first inlet K2 and the second outlet K3. The second inlet K4 and the first outlet K1 serve as the inlet and outlet of the external cooling medium, respectively. Thus, the external cooling medium enters through the second inlet K4, passes through the second cooling channel T2 of the cooling block 28 and the connecting channel 31 in sequence, enters the first cooling channel T1 of the cooling ring 27, and exits from the first outlet K1 on the cooling ring 27 to remove heat.

[0080] Similarly, in other embodiments, the connecting channel 31 may also be configured to connect the first outlet K1 and the second inlet K4, with the first inlet K2 and the second outlet K3 serving as the inlet and outlet of the external cooling medium, respectively.

[0081] See also Figure 8 Optionally, the outer periphery of the first pipe 30 is spaced apart from the inner periphery of the receiving cavity Q1, so that the cooling medium contained in the receiving cavity Q1 can surround the outer periphery of the first pipe 30, ensuring uniform circumferential cooling of the first pipe 30 and having a better cooling effect.

[0082] In this embodiment, the cooling medium channel between the cooling ring 27 and the cooling block 28 is connected in series, which can greatly improve the space utilization of the print head, facilitate miniaturization design, and has excellent heat dissipation effect, which can greatly improve the extrusion speed of consumables, thereby increasing the printing speed.

[0083] In other embodiments, the cooling ring 27 and the cooling block 28 can also be connected in parallel.

[0084] In this embodiment, the extrusion gear assembly 14, cooling block 28, and nozzle assembly 15 are arranged sequentially from top to bottom. The consumable output port at the lower end of the extrusion gear assembly 14 corresponds to the consumable inlet K5 of the cooling block 28. One end of the throat tube 18 is inserted into and fitted to the consumable outlet K6, and the other end is connected to the nozzle 16a. To secure the throat tube 18, in this embodiment, the cooling block 28 is also provided with a second pipe 37 that connects to the first pipe 30. A retaining member (not shown in the figure) can be provided in the second pipe 37 to hold the throat tube. For example, the cooling block 28 can be provided with a second pipe 37 connected between the housing 29 and the first pipe 30. The second pipe 37 has a set screw hole K10 that passes through the surface of the housing 29 and extends to the consumable outlet K6 for screwing in the retaining member (such as a tightening screw) to lock the throat tube 18 inserted into the consumable outlet K6.

[0085] This embodiment also provides another nozzle assembly 15a. See [link to previous document]. Figure 9 and Figure 10 In the nozzle assembly 15a, the nozzle is configured to include a spiral flow channel tube 53 and a terminal nozzle 52. One end of the spiral flow channel tube 53 is connected to the consumable outlet K6 via a throat tube 18, and the other end is connected to the terminal nozzle 52. The heating element of the nozzle assembly 15a is a heating wire 54 that extends spirally around the spiral flow channel tube 53. A heat insulation sleeve may also be fitted over the spiral flow channel tube 53 and the heating wire 54 of the nozzle assembly 15a. Figure 9 and Figure 10 (Not shown in the image).

[0086] One of the core issues in high-speed printing is the high-speed or high-flow-rate extrusion of filaments. High-flow-rate extrusion of filaments means that more heat needs to be provided to the filament per unit time. If the heat exchange rate is insufficient, the filament will not be able to melt, resulting in a "hot outside, cold inside" phenomenon. As the temperature decreases after heating, the non-Newtonian fluid properties of the filament will exhibit an increase in dynamic viscosity, making it difficult to be extruded by the extruder.

[0087] Some known technologies increase the heating area by directly extending the length of the heating tube, thereby increasing the heating capacity to accommodate higher material extrusion speeds. However, this reduces the space utilization of 3D printing equipment in the gravity direction, resulting in increasingly larger volumes for the same printing size.

[0088] And adopt Figure 9 and Figure 10The 3D printing equipment 100 with nozzle assembly 15a shown has filament extruded through filament inlet K5, passing through cooling block 28 and throat 18, and then entering spiral flow channel 53 where it is heated by spirally extended heating wire 54, finally being extruded through end nozzle 52. Heat is generated by the heating wire 54 wound around the spiral flow channel 53 and transferred to the spiral flow channel 53, which has a spiral flow channel inside. The filament is heated inside the spiral flow channel by convection, conduction, and other methods. Because the heating area of ​​the spiral flow channel is significantly increased compared to a direct flow channel, it can provide more heat per unit time, which is more conducive to high-flow extrusion of the filament.

[0089] The heat from the spiral flow channel 53 is insulated by the throat 18 and then introduced into the cooling block 28, where it is carried away by the cooling medium (such as water) inside the cooling block 28, reducing the thermal impact on upstream consumables.

[0090] Optionally, the spiral flow channel tube 53 can be supported and connected by a support frame 55. For example, in this embodiment, the support frame 55 includes multiple support blocks spaced apart between the cooling block 28 and the end nozzle 52 and fitted over the spiral flow channel tube 53. For example, the multiple support blocks are a first support block 56, a second support block 57, and a third support block 60. The first support block 56 is fixedly connected to the cooling block 28 by a connector 58 (e.g., a reinforcing screw), the second support block 57 is fixedly connected to the first support block 56 by a connector 58, and the third support block 60 is fixedly connected to the second support block 57 by a connector 58. The spiral flow channel tube 53 is fixedly supported at the connection points by the first support block 56, the second support block 57, and the third support block 60 to ensure reliable support of the spiral flow channel tube 53. For example, each support block can be configured as an annular shape, and the spiral flow channel tube 53 fits into the inner hole of the annular shape. The end nozzle 52 is fixedly connected to the second support block 57.

[0091] Heat from the spiral flow channel 53 is conducted to the first support block 56, the second support block 57, and the third support block 60. Therefore, temperature sensors 59 can be placed at the first support block 56, the second support block 57, and the third support block 60 to detect the temperature. The detected temperature is reported to the processor for PID control.

[0092] In this embodiment, the temperature sensor 59 may optionally be an NTC or platinum resistance thermometer, and the first support block 56, the second support block 57, and the third support block 60 may be made of high-strength, high-thermal-conductivity metals such as aluminum alloys.

[0093] The spiral flow channel tube 53 can be manufactured using metal 3D printing or coiling methods. It does not necessarily have to be a standard spiral tube; it may also have other curved shapes, and its length is not limited. The spiral flow channel tube 53 can also be used only in a localized area of ​​the heating section, connecting the first support block 56, the second support block 57, and the third support block 60 using a pressing or threaded method. The throat tube 18 and the end nozzle 52 are connected at both ends using an external thread structure. The spiral flow channel tube 53 can be made of high thermal conductivity materials such as brass or aluminum alloy, which can make the temperature more uniform.

[0094] The heating wire 54 can be a resistance wire made of common materials such as nickel-chromium, iron-chromium-aluminum, and nickel-chromium-iron.

[0095] The throat 18 can be made of titanium alloy or a chimera-type structure of copper alloy-titanium alloy-copper alloy. Optionally, in this embodiment, the 3D printing equipment 100 also includes a housing 19, a support 20, and an interlayer cooling fan 21. The housing 19 has a lateral opening K9; the support 20 is connected to the lateral opening K9; the support 20 includes a back plate 22 and a back frame 23, the back frame 23 being connected to the upper part of the back plate 22 and recessed inwards towards the housing 19. A ventilation hole K7 is provided on the side of the housing 19 away from the support 20. The interlayer cooling fan 21 is located between the housing 19 and the back plate 22, used to promote cooling and shaping of the filament during the printing process through air cooling. A cooling block 28 is sandwiched between the interlayer cooling fan 21 and the back plate 22. An extrusion gear assembly 14 is located within the back frame 23 and supported on the cooling block 28 by a connecting block 24, the connecting block 24 having a through hole K8 for allowing filament to pass through and enter the filament channel S1.

[0096] See also Figure 11 The cooling assembly 12 in this embodiment also includes a cooling medium container 33, a fluid pump 34, a radiator 35, and a radiator fan 36. The cooling medium container 33, fluid pump 34, cooling block 28, cooling ring 27, and radiator 35 are connected end-to-end to form a cooling cycle, used to remove heat generated by the extrusion motor 13 and heat transferred from the throat 18. The radiator fan 36 corresponds to the radiator 35 and is used to air-cool the radiator 35. It should be noted that... Figure 11The cooling block 28 and cooling ring 27 are simplified as two different heat sources. In this cooling cycle, the cooling medium (such as water) is powered by the fluid pump 34. The cooling medium flows through the cooling block 28 and cooling ring 27, carrying away heat, and is dissipated by the radiator fan 36 at the radiator 35. The fluid pump 34 can be a DDC pump, D5 pump, or a common centrifugal pump. The structural shape of the cooling block 28 and cooling ring 27 is not limited; an aluminum alloy structure can be used to reduce the weight of the extruder, and internal flow channels can be opened. The selection of the radiator 35, cooling medium container 33, etc., is selected and designed according to the actual product requirements. The components in the cooling cycle can be connected by pipes made of materials such as silicone, PVC, and PU. There are no restrictions on the size of the pipes; for example, pipes with an outer diameter of 6mm and an inner diameter of 4mm or larger, or pipes with an outer diameter of 4mm and an inner diameter of 2-2.5mm can be used. The connection between pipes can be a quick-connect, quick-tight, or pagoda structure, which is not limited here.

[0097] This embodiment also provides a 3D printing method, which includes:

[0098] A cooling block 28 is provided between the throat 18 of the extrusion gear assembly 14 and the nozzle assembly 15 of the 3D printing equipment 100, and a cooling ring 27 is provided on the extrusion motor 13. The cooling block 28 and the cooling ring 27 are interconnected through a liquid channel; the cooling block 28 is provided with a consumable channel S1.

[0099] The extrusion motor 13 of the 3D printing equipment 100 drives the extrusion gear assembly 14 to rotate to transport consumables. The consumables transported by the extrusion gear assembly 14 pass through the consumable channel S1 of the cooling block 28 and enter the nozzle assembly 15 through the throat 18, and are ejected from the nozzle assembly 15 to achieve extrusion printing.

[0100] During extrusion printing, the cooling block 28 and cooling ring 27 are liquid cooled to remove the heat transferred from the nozzle assembly 15 through the throat 18 and the heat generated by the extrusion motor 13 during operation, so as to control the temperature of the consumable at the extrusion gear assembly 14 below the set value.

[0101] By controlling the temperature of the consumable at the extrusion gear assembly 14 to be below a set value, the consumable passing through the extrusion gear assembly 14 will not melt or soften prematurely.

[0102] Figure 12The diagram shows temperature contours of the printhead during printing on a scaled-down 3D printing device. This device uses a radiator and fan structure for heat dissipation. With the extrusion motor generating 13.5W of heat (output current 1.2A) and the heating nozzle temperature at 230°C, the radiator temperature is 57°C, while the temperature at the extrusion motor reaches a high of 77°C. The temperature of the extrusion gear assembly exceeds 65°C due to heat conduction. In contrast, commonly used filaments such as PLA have a softening temperature of around 50°C. Clearly, this implementation is unsuitable for high-speed extrusion scenarios because, with filaments having low softening temperatures (such as PLA), the filament is easily softened by the heat conducted by the extrusion motor as it passes through the extrusion gear assembly. This softening can affect extrusion speed and volume accuracy.

[0103] Figure 13 The temperature cloud map of the print head 10 of the 3D printing equipment 100 in this embodiment is shown during printing. The 3D printing equipment 100 in this embodiment uses the aforementioned cooling block 28 and cooling ring 27 for centralized liquid cooling. When the heat of the extrusion motor 13 is 13.5W (output current is 1.2A), the temperature of the nozzle 16a is 230°C, and the coolant is cooling water with an inlet temperature of 25°C, the temperature of the extrusion motor 13 is less than 29°C, that is, the temperature rise is 4°C, the temperature of the cooling component 12 is close to 25°C, and there is still room for improvement in the extrusion performance such as the output current of the extrusion motor 13 and even the extrusion force F, which can be well adapted to the needs of high-speed printing.

[0104] In summary, the cooling component 12, print head 10, 3D printing equipment 100, and 3D printing method in this application embodiment can reduce the temperature at the extrusion gear assembly 14, preventing the filament from softening prematurely due to heat at the extrusion gear assembly 14. This ensures that the extrusion gear assembly 14 delivers the filament accurately and powerfully, making it suitable for the high extrusion speed requirements of high-speed extrusion scenarios. It can also maintain precise control of the filament extrusion amount, which is suitable for the development trend of high-speed printing. Furthermore, by achieving centralized cooling through the cooling block 28 and cooling ring 27, compared to the known radiator + fan configuration, the structure is more compact and simple, which is more conducive to the development of structural miniaturization.

[0105] The above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to the above preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of this application should not depart from the spirit and scope of the technical solutions of this application.

Claims

1. A cooling assembly for the print head of a 3D printing device, characterized in that: The cooling assembly includes a first cooling section and a second cooling section; The first cooling section includes a first cooling channel for the flow of cooling medium, the first cooling channel being thermally coupled to the extrusion motor of the printhead; the first cooling section further includes a first inlet and a first outlet connecting the first cooling channel, the first cooling channel being configured to at least partially surround the outer periphery of the extrusion motor, the cooling medium entering the first cooling channel through the first inlet and flowing out through the first outlet; the first cooling section includes a cooling ring, the cooling ring at least partially surrounding the outer periphery of the extrusion motor and being thermally coupled to the extrusion motor, the extrusion motor being drively connected to an extrusion gear assembly, the extrusion motor being used to drive the extrusion gear assembly to rotate to convey consumables; the first cooling channel is disposed within the cooling ring; The second cooling section includes a second cooling channel for the flow of cooling medium, and the second cooling section is thermally coupled to the throat of the print head; the second cooling section includes a cooling block connected between the throat and the extrusion gear assembly; the second cooling channel is disposed inside the cooling block; the first cooling section and the second cooling section are interconnected, and the cooling assembly further includes a connecting channel connecting the first cooling section and the second cooling section; The cooling block includes a first conduit for accommodating the throat, and the second cooling channel is configured to at least partially surround the outer periphery of the first conduit. The second cooling section further includes a second inlet and a second outlet that connect to the second cooling channel. The cooling medium enters the second cooling channel through the second inlet and flows out through the second outlet. The cooling medium is configured to enter the second cooling channel from the second inlet, exit from the second outlet, and enter the first cooling channel from the first inlet through the connecting channel, exiting from the first outlet.

2. The cooling assembly according to claim 1, characterized in that: The cooling block also includes a second pipe that connects to the first pipe, and the second pipe is provided with a support member for supporting the throat.

3. The cooling assembly according to claim 1, characterized in that: The cooling assembly also includes a cooling medium container, a fluid pump, and a radiator; The cooling medium container, the fluid pump, the second cooling section, the first cooling section, and the radiator are connected in sequence, and the cooling medium container is also connected to the radiator to form a circulation.

4. The cooling assembly according to any one of claims 1 to 3, characterized in that: The cooling medium is a coolant or a cooling gas.

5. A printhead, characterized in that, Includes an extrusion assembly, a nozzle assembly, and a cooling assembly as described in any one of claims 1 to 4; The extrusion assembly includes an extrusion motor and an extrusion gear set, wherein the extrusion motor is connected to and drives the extrusion gear set to rotate; The nozzle assembly includes a heating element, a throat, and a nozzle, the heating element being thermally coupled to the nozzle, and the throat being configured to connect the nozzle and the extrusion assembly.

6. The printhead according to claim 5, characterized in that: The nozzle includes a spiral flow channel tube and a discharge nozzle, with one end of the spiral flow channel tube connected to the throat tube and the other end connected to the discharge nozzle; The heating element is a heating wire that extends spirally along the spiral flow channel and is thermally coupled to the spiral flow channel.

7. The printhead according to claim 6, characterized in that: The nozzle also includes a plurality of support blocks arranged sequentially along the discharge direction of the nozzle, and the plurality of support blocks are fixedly connected to each other and to the second cooling part by connectors. The spiral flow channel is supported by a plurality of support blocks; Temperature sensors are provided at each of the support blocks, and the temperature sensors correspond to different positions of the spiral flow channel tube to detect the temperature at different positions of the spiral flow channel tube. The temperature is used to control the flow rate of the cooling medium and / or the heating temperature of the heating element.

8. A 3D printing device, characterized in that, It includes the cooling component as described in any one of claims 1 to 4 or the printhead as described in any one of claims 5 to 7.

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