Hot end assembly and 3D printer

Abstract

The utility model relates to a hot end assembly and a 3D printer, the hot end assembly comprises a heat dissipation piece and a heat conduction block, a through channel is formed in the heat conduction block, the channel communicates with a feeding port of a nozzle, and printing supplies enter the channel through the heat dissipation piece; at least one protrusion is arranged in the channel, and the printing supplies enter the nozzle through the protrusions and are extruded out through the nozzle. The protrusions are arranged in the channel and can adjust the channel into a special-shaped channel or divide the channel into a plurality of sub-channels, so that the contact area of the printing supplies and the channel is increased, the heating area of the printing supplies is increased, the printing supplies are fully fused, the printing speed is increased, and the printing flow is increased.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of printing technology, in particular to a hot end assembly and a 3D printer. BACKGROUND

[0002] Fused deposition modeling (FDM) is a technology for constructing three-dimensional objects by layer printing based on a digital model using adhesible materials such as plastic or powdered metal. The 3D printer involved in the technology supplies printing consumables to the print head in the form of a filament. The print head extrudes the cold printing consumables to the hot end of the print head through an extruder. The hot end heats the cold printing consumables to make them fully melt and then extrude from the nozzle in a layer-by-layer manner to print three-dimensional objects.

[0003] With the diversification of industrial applications, users have increasingly urgent needs for high-speed and high-flow printing of 3D printers. However, the current commonly used 3D printers have a slow speed of extruding printing consumables from the nozzle, which restricts the development of 3D printers. CONTENT OF THE UTILITY MODEL

[0004] To solve the above problems, the present application provides a hot end assembly, which optimizes the structure of the hot end assembly, sets a special structure at the end of the nozzle inlet to increase the heating area of the printing consumables, so that the printing consumables can be fully melted before entering the nozzle, thereby enabling the printing consumables to be smoothly extruded from the nozzle, and further improving the printing speed and increasing the printing flow. In addition, the present application also provides a 3D printer equipped with the hot end assembly, which specifically includes the following schemes:

[0005] In a first aspect, the present application provides a hot end assembly for providing molten printing consumables to a nozzle, comprising a heat dissipation member and a heat conduction block, the heat conduction block is provided with a through channel, the channel is in communication with the inlet of the nozzle; the printing consumables enter the channel through the heat dissipation member;

[0006] The channel is provided with at least one protrusion, the printing consumables enter the nozzle through the protrusion and are extruded from the nozzle.

[0007] The application sets a heat-conducting block at the nozzle inlet end and sets a channel through the heat-conducting block, so that the heat-conducting block can heat the printing consumables flowing through the channel, so that the printing consumables are melted in advance before entering the nozzle, so as to facilitate the nozzle extrusion to realize printing. By setting the heat-dissipating piece, the printing consumables first pass through the heat-dissipating piece and then enter the channel, so as to ensure that the printing consumables are in solid state before entering the channel, thereby avoiding that the printing consumables are partially softened and block the inlet of the channel before entering the channel. Further, the application sets at least one protrusion in the channel, and the printing consumables flow into the nozzle through the protrusion. The protrusion can adjust the channel into a special-shaped channel or separate the channel into multiple sub-channels, so as to increase the inner surface area of the channel, thereby increasing the contact area of the printing consumables with the inner wall of the channel and the protrusion, increasing the heating area of the printing consumables, and further melting the printing consumables sufficiently, so as to improve the printing speed and increase the printing flow.

[0008] In an embodiment, the nozzle is detachably connected to the heat-conducting block.

[0009] In the embodiment, the nozzle is detachably connected to the heat-conducting block, so that the nozzle can be replaced while ensuring normal printing. In addition, since the nozzle is easy to wear, the application sets the protrusion in the heat-conducting block instead of the nozzle, so that only the nozzle needs to be replaced when the nozzle reaches the service life, thereby reducing the maintenance cost.

[0010] In an embodiment, the number of the protrusions is multiple, and the multiple protrusions are arranged along the circumference of the channel.

[0011] In the embodiment, the number of the protrusions is multiple, and the multiple protrusions are arranged along the circumference of the channel, so that the surface layer of the printing consumables is divided by the multiple protrusions when the printing consumables flow through the protrusions of the channel, and the total heating area of the printing consumables is increased, so as to be melted sufficiently.

[0012] In an embodiment, the circumferential size of each protrusion gradually decreases from the inner wall of the channel towards the center of the channel.

[0013] In the embodiment, the circumferential size of each protrusion gradually decreases from the inner wall of the channel towards the center of the channel, that is, the size of the part of the protrusion closer to the center axis of the channel along the circumference of the channel is smaller, so as to ensure the strength of the protrusion while maximizing the heating area of the printing consumables.

[0014] In an embodiment, the protrusion is an inlay, and the inlay is embedded in the inner wall of the channel.

[0015] In the embodiment, the protrusion is set as an inlay, so as to ensure the convenience of installation and simplify the manufacturing process of the heat-conducting block.

[0016] In an embodiment, the number of inserts is one.

[0017] In an embodiment, the outer circumferential surface of the insert abuts against the inner wall of the channel, the insert is provided with a flow hole in the middle, and the printing consumable flows into the nozzle through the flow hole.

[0018] In the present embodiment, the insert can also heat the printing consumable, so that the printing consumable is fully melted to flow into the nozzle from the flow hole.

[0019] In an embodiment, the number of flow holes is multiple, and the multiple flow holes are in communication with each other at the center of the channel.

[0020] In the present embodiment, by setting the number of flow holes to be multiple, the multiple flow holes can distribute the printing consumable, and the printing consumable flows into the nozzle from different flow holes, which can further increase the heated area and improve the melting effect.

[0021] In an embodiment, along the direction from the inner wall of the channel to the center of the channel, the flow hole comprises a first end and a second end, the second end is close to the center of the channel, and the opening size of the second end is smaller than that of the first end.

[0022] In the present embodiment, by setting the size of the end of the flow hole close to the center of the channel to be smaller, it can be ensured that the inner core of the printing consumable is fully extruded and heated. By setting the size of the end of the flow hole away from the center of the channel to be larger, the resistance of the part of the outer layer of the printing consumable that has been melted when flowing through the flow hole can be reduced.

[0023] In an embodiment, the number of flow holes is multiple, and the multiple flow holes are arranged outside the center of the channel, and each flow hole is isolated from each other.

[0024] In the present embodiment, when the heat-conducting block heats the printing consumable in the channel, the surface layer of the printing consumable is usually heated first, and when the surface layer of the printing consumable is in a molten state, the inner core thereof can still be in a solid state. The present application arranges multiple flow holes outside the center of the channel to ensure that the inner core of the printing consumable in a solid state will not temporarily flow into the nozzle, and only when it is fully melted to have fluid properties can it flow into the nozzle from the surrounding flow holes, so as to avoid clogging the nozzle.

[0025] In an embodiment, the channel is further provided with a flow guide, the flow guide is arranged on the side of the protrusion away from the nozzle and is concentric with the channel, and along the length direction of the channel, the circumferential cross-sectional area of the flow guide decreases from the side close to the protrusion to the side away from the protrusion.

[0026] In the embodiment, along the length direction of the channel, the flow guide member is arranged on the side of the protrusion away from the nozzle to limit the flow path of the printing consumable when entering the channel where the protrusion is arranged. Specifically, the flow guide member is arranged concentrically with the channel, and the circumferential section of the flow guide member decreases from the direction close to the protrusion to the direction away from the protrusion, that is, the flow guide member is arranged in a conical structure. The surface layer of the printing consumable is stripped by the flow guide member, and the melting speed of the inner core of the printing consumable is accelerated.

[0027] In an embodiment, along the length direction of the channel, the channel includes a pre-melting section and a flow guide section, the pre-melting section is located on the side of the flow guide section away from the nozzle, and the protrusion is arranged in the flow guide section.

[0028] In the embodiment, the channel is divided into a pre-melting section and a flow guide section. The pre-melting section is used to melt the surface layer of the printing consumable in advance, and the flow guide section is used to limit the flow path of the printing consumable in a molten state. Specifically, the pre-melting section is arranged on the side of the flow guide section away from the nozzle, and the protrusion is arranged in the flow guide section. Part of the printing consumable is melted in advance to facilitate the protrusion to divide the printing consumable, so that the inner core of the printing consumable is easily fully melted in the flow guide section.

[0029] In a second aspect, the application provides a 3D printer, which includes a print head and the heat end assembly in any of the embodiments described above. The heat end assembly is mounted on the print head.

[0030] It can be understood that the 3D printer provided in the second aspect of the application also has all the beneficial effects that can be achieved in any of the embodiments of the first aspect of the application because it adopts the print head provided in the first aspect of the application. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 It is a structure exploded view of the heat end assembly provided in the first embodiment of the application.

[0032] Figure 2 It is a partial structure schematic view of the heat end assembly provided in the first embodiment of the application.

[0033] Figure 3 It is a top view of the heat end assembly provided in the first embodiment of the application.

[0034] Figure 4 It is a structure schematic view of the protrusion and the bushing provided in an embodiment of the application.

[0035] Figure 5 It is a top view of the heat end assembly provided in the second embodiment of the application.

[0036] Figure 6 It is a structure exploded view of the heat end assembly provided in the second embodiment of the application.

[0037] Figure 7 A structure diagram of the inlay provided in the first embodiment of the present application;

[0038] Figure 8 A top view of the inlay and the heat-conducting block provided in the first embodiment of the present application;

[0039] Figure 9 A top view of the hot-end assembly provided in the third embodiment of the present application;

[0040] Figure 10 A top view of the hot-end assembly provided in the fourth embodiment of the present application;

[0041] Figure 11 A top view of the hot-end assembly provided in the fifth embodiment of the present application;

[0042] Figure 12 A top view of the hot-end assembly provided in the sixth embodiment of the present application;

[0043] Figure 13 A top view of the hot-end assembly provided in the seventh embodiment of the present application;

[0044] Figure 14 A top view of the hot-end assembly provided in the eighth embodiment of the present application;

[0045] Figure 15 A top view of the hot-end assembly provided in the ninth embodiment of the present application;

[0046] Figure 16 A structure diagram of the hot-end assembly provided in an embodiment of the present application;

[0047] Figure 17 A structure diagram of the protrusion and the flow guide provided in an embodiment of the present application;

[0048] Figure 18 A structure diagram of the hot-end assembly provided in another embodiment of the present application;

[0049] Figure 19 A top view of the hot-end assembly provided in the tenth embodiment of the present application;

[0050] Figure 20 A top view of the hot-end assembly provided in the eleventh embodiment of the present application;

[0051] Figure 21 A structure diagram of the printhead provided in an embodiment of the present application.

[0052] Reference signs: 200 - print head; 100 - hot end assembly; 10 - heat conducting block; 11 - channel; 112 - pre-fusion section; 113 - flow guiding section; 114 - first sub-heat conducting block; 115 - second sub-heat conducting block; 20 - nozzle; 30 - protrusion; 40 - bushing; 50 - heat insulation throat; 60 - heat dissipating member; 70 - flow guiding member; 80 - inlay; 81 - flow passage hole; 811 - first end; 812 - second end. DETAILED DESCRIPTION

[0053] The serial numbers of components used herein, such as "first", "second", etc., are only used to distinguish the described objects, and do not have any sequential or technical meaning. Unless otherwise specified, the terms "connected", "coupled" used in the present application include direct and indirect connections (couplings). The directional terms used in the present application, such as "upper", "lower", "front", "back", "left", "right", "inner", "outer", "side", etc., are only the directions with reference to the attached drawings, therefore, the directional terms used are for better, clearer description and understanding of the present application, and are not intended to indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0054] In the description of the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connected", "coupling" should be understood broadly, for example, can be fixedly connected, or can be detachably connected, or integrally connected; can be mechanically connected; can be directly connected, or indirectly connected through an intermediate medium; can be the internal communication of two elements. Those skilled in the art can understand the specific meaning of the above terms in the present application according to the specific circumstances. The terms "first", "second", etc. in the specification and claims of the present application and the drawings are used to distinguish different objects, and are not used to describe a specific order. In addition, the terms "include", "may include", "contain" or "may contain" used in the present application represent the existence of the corresponding functions, operations, elements, etc. disclosed, and do not limit other one or more functions, operations, elements, etc. In addition, the term "include" or "contain" means the existence of the corresponding features, numbers, steps, operations, elements, components or combinations thereof disclosed in the specification, and does not exclude the existence or addition of one or more other features, numbers, steps, operations, elements, components or combinations thereof, and is intended to cover non-exclusive inclusion.

[0055] 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 to which the present application belongs. The terms used in the specification of the present application are only for the purpose of describing the specific embodiments, and are not intended to limit the present application.

[0056] Please see the drawings for referenceFigures 1 to 3 ,in Figure 1 This is an exploded view of the structure of the hot-end assembly 100 provided in the first embodiment of this application; Figure 2 This is a partial structural schematic diagram of the hot end assembly 100 provided in the first embodiment of this application; Figure 3 This is a top view of the hot end assembly 100 provided in the first embodiment of this application.

[0057] like Figures 1 to 3 As shown, in one embodiment, the hot-end assembly 100 provided in this application includes a heat-conducting block 10 and a heat sink 60. The heat-conducting block 10 has a channel 11 extending vertically through itself, and the heat-conducting block 10 is located vertically above the nozzle 20. The channel 11 communicates with the feed inlet of the nozzle 20. The heat sink 60 is located vertically on the side of the heat-conducting block 10 away from the nozzle 20. The printing filament first enters the channel 11 through the heat sink 60. The heat sink 60 is used for heat dissipation to ensure that the printing filament is solid before entering the channel 11, preventing the printing filament from partially softening and blocking the inlet of the channel 11 before entering the channel 11. The heat-conducting block 10 serves as the hot end of the hot-end assembly 100, providing heat to the printing filament to melt it. In one embodiment, the heat-conducting block 10 is connected to an external heat source to generate heat, i.e., the heat-conducting block 10 is only used for conducting heat. In another embodiment, the heat-conducting block 10 can heat the printing filament through its own heat, i.e., the heat-conducting block 10 can be used for heat generation.

[0058] In one embodiment, the hot end assembly 100 further includes an extruder (not shown) positioned vertically above the heat sink 60 for extruding and conveying cold printing filament into the channel 11 of the heat-conducting block 10. The printing filament is heated to a molten state within the channel 11 and flows along the channel 11 into the nozzle 20, finally being extruded from the nozzle 20 orifice to achieve printing.

[0059] Furthermore, the channel 11 of this application is also provided with at least one protrusion 30, through which the printing consumable enters the nozzle 20 and is extruded. The protrusion 30 extends radially from the inner wall of the channel 11 toward the center of the channel 11. The arrangement of the protrusion 30 can adjust the channel 11 into an irregularly shaped channel or divide the channel 11 into multiple sub-channels to increase the heating area of ​​the printing consumable at the protrusion 30. For example, in Figure 3In the shown embodiment, the channel 11 is cylindrical in shape, and the number of protrusions 30 is three, which are arranged along the circumference of the channel 11 to adjust the channel 11 into a Y shape, thereby increasing the inner surface area of the channel 11, increasing the contact area of the printing material with the inner wall of the channel 11 and the protrusions 30, and further increasing the heating area of the printing material, so that the printing material can melt more sufficiently to flow smoothly into the nozzle 20 and be easily sprayed out of the nozzle 20, thereby improving the printing speed and increasing the printing flow of the hot end assembly 100.

[0060] In the above embodiment, the position and number of the protrusions 30 are only exemplary. For example, in another embodiment, the number of the protrusions 30 can be only one or four or the like, and the channel 11 can also be adjusted into a non-cylindrical channel 11, which can also increase the heating area of the printing material to a certain extent.

[0061] In an embodiment, the nozzle 20 and the heat conduction block 10 are detachably connected. It can be understood that the detachable connection of the nozzle 20 and the heat conduction block 10 can ensure the normal implementation of printing while also allowing the nozzle 20 to be replaced. In addition, since the nozzle 20 is prone to wear, the protrusions 30 are arranged in the channel 11 of the heat conduction block 10 instead of the nozzle 20, so that only the nozzle 20 needs to be replaced when the nozzle 20 reaches the service life, thereby reducing the maintenance cost.

[0062] In an embodiment, the protrusions 30 and the heat conduction block 10 are an integral structure. That is, the protrusions 30 are a part of the inner wall of the channel 11 that protrudes radially. In another embodiment, the protrusions 30 are another heat conduction structure that is different from the heat conduction block 10, and the protrusions 30 can be embedded in the channel 11 or clamped in the channel 11, and the like, which are not particularly limited by the present application. For example, in Figure 1 and Figure 2 In the shown embodiment, the protrusions 30 are another structure that is fixedly connected in the channel 11 of the heat conduction block 10. In this case, the periphery of the protrusions 30 can be sleeved with a bushing 40 (see Figure 4 for the structural schematic diagram of the protrusions 30 and the bushing 40 provided in an embodiment of the present application), and the bushing 40 can be directly embedded into the channel 11 from the bottom of the channel 11. It can be understood that the protrusions 30 and the heat conduction block 10 are arranged as a separate structure, which can be replaced when any one of the protrusions 30 and the heat conduction block 10 is damaged, and can further reduce the maintenance cost.

[0063] In another embodiment, the bushing 40 and the protrusions 30 are an integrally formed structure. That is, the structure of the protrusions 30 can be designed when the bushing 40 is machined, and the assembly step can be omitted.

[0064] In one embodiment, the heat end assembly 100 provided by the present application further comprises a heat insulation throat 50, which is located at the end of the heat conducting block 10 away from the nozzle 20, and the lower end of the heat insulation throat 50 extends into and communicates with the channel 11. The heat dissipation member 60 is arranged in the vertical direction and at the upper end of the heat conducting block 10, and the heat dissipation member 60 is sleeved outside the heat insulation throat 50. The printing consumables first pass through the heat insulation throat 50 after being extruded from the extruder, and then enter the channel 11 of the heat conducting block 10. The heat dissipation member 60 is used to dissipate heat of the heat end assembly 100, so as to avoid that the temperature inside the heat end assembly 100 is too high to affect the electrical elements inside. At the same time, the heat dissipation member 60 is also used to reduce the temperature of the heat insulation throat 50, so as to avoid that the printing consumables are softened before entering the heat conducting block 10 and cause blockage.

[0065] In the above embodiment, the plurality of protrusions 30 are arranged in the circumferential direction of the channel 11, so that when the printing consumables flow through the protrusions 30 of the channel 11, the surface layer of the printing consumables is divided by the plurality of protrusions 30, and the total heating area of the printing consumables is increased, so as to be fully melted.

[0066] Please see Figure 5 , Figure 5 for the top view of the heat end assembly 100 provided in the second embodiment of the present application.

[0067] As shown in Figure 5 , in one embodiment, the circumferential size of each protrusion 30 gradually decreases from the inner wall of the channel 11 towards the center of the channel 11. That is, the size of the part of the protrusion 30 closer to the central axis of the channel 11 along the circumferential direction of the channel 11 is smaller. Specifically, in the schematic view shown in Figure 5 , the cross section of the protrusion 30 is similar to a triangle. It can be understood that in this embodiment, by setting the size of the part of the protrusion 30 closer to the central axis of the channel 11 along the circumferential direction of the channel 11 to be smaller, the strength of the protrusion 30 is ensured while the heating area of the printing consumables is maximized.

[0068] In the embodiment shown in Figure 5 , the distance between the adjacent two protrusions 30 along the circumferential direction of the channel 11 is constant. In the embodiment shown in Figure 3 , the distance between the adjacent two protrusions 30 first increases and then decreases from the inner wall of the channel 11 towards the center of the channel 11. It can be understood that by setting the distance between the adjacent two protrusions 30 first increases and then decreases from the inner wall of the channel 11 towards the center of the channel 11, the core of the printing consumables can be fully extruded and heated, and the surface layer of the printing consumables can easily pass through the gap close to the inner wall of the channel 11. In some feasible embodiments, the protrusion 30 can be an inlay part which is in interference fit with the channel 11.

[0069] Please see Figures 6 to 8 , whereinFigure 6 A structural exploded view of the hot end assembly 100 provided in the second embodiment of the present application; Figure 7 A structural schematic view of the inlay 80 provided in the first embodiment of the present application; Figure 8 A top view of the inlay 80 and the heat conduction block 10 provided in the first embodiment of the present application.

[0070] As shown in Figures 6 to 8 an embodiment, the protrusion 30 is an inlay 80, which is embedded in the inner wall of the channel 11. In this embodiment, by setting the protrusion 30 as the inlay 80, both the convenience of installation and the manufacturing process of the heat conduction block 10 can be simplified.

[0071] In an embodiment, the number of the inlays 80 is one. One inlay 80 is embedded in the inner wall of the channel 11.

[0072] In an embodiment, the outer peripheral surface of the inlay 80 is in close contact with the inner wall of the channel 11, and the inlay 80 is provided with flow passage holes 81, each of which penetrates the inlay 80 in the vertical direction. The printing consumables flow into the nozzle 20 through the flow passage holes 81. The inlay 80 can conduct heat, thereby heating the printing consumables to make the printing consumables fully melt to flow into the nozzle 20 from the flow passage holes 81.

[0073] In Figure 7 and Figure 8 the embodiments shown, the number of the flow passage holes 81 is multiple, and the multiple flow passage holes 81 are in communication with each other at the center of the channel 11. Specifically, the number of the flow passage holes 81 is three, and the three flow passage holes 81 are arranged at intervals along the circumferential direction of the channel 11. Each of the flow passage holes 81 extends along the radial direction of the channel 11, and the end of each of the flow passage holes 81 away from the inner wall of the channel 11 is in communication with the other flow passage holes 81 at the center of the channel 11 to form a Y-shaped through hole. It can be understood that by setting the number of the flow passage holes 81 as multiple, the multiple flow passage holes 81 can divide the printing consumables, and the printing consumables flow into the nozzle 20 from different flow passage holes 81, which can further increase the heating area and improve the melting effect.

[0074] In the above embodiments, the number of the flow passage holes 81 and the circumferential dimension of each of the flow passage holes 81 are only exemplary, that is, the number of the flow passage holes 81 includes but is not limited to three, and the circumferential dimension of the flow passage holes 81 is not particularly limited. For example, in Figure 9 ( Figure 9 the embodiment shown in the top view of the hot end assembly 100 provided in the third embodiment of the present application), the number of the flow passage holes 81 is four, and the four flow passage holes 81 are arranged at intervals along the circumferential direction of the channel 11 to form a cross-shaped through hole, which also achieves the same beneficial effects. In Figure 10 ( Figure 10In the embodiment shown in the top view of the thermal end assembly 100 provided in the fourth embodiment of the present application, the circumferential dimension of each flow channel hole 81 is relatively large, which can also improve the melting effect of the printing consumable.

[0075] Please see Figure 11 , Figure 11 The top view of the thermal end assembly 100 provided in the fifth embodiment of the present application.

[0076] As Figure 11 shown, in an embodiment, along the length direction of the channel 11, from the inner wall of the channel 11 to the center direction of the channel 11, the flow channel hole 81 includes a first end 811 and a second end 812. The second end 812 is closer to the center of the channel 11 than the first end 811. The opening size of the second end 812 is smaller than that of the first end 811.

[0077] Setting the size of the end of the flow channel hole 81 close to the center of the channel 11 to be small can ensure that the inner core of the printing consumable is fully extruded and heated. Setting the size of the end of the flow channel hole 81 away from the center of the channel 11 to be large can reduce the resistance of the outer layer of the printing consumable that has been melted when flowing through the flow channel hole 81.

[0078] The present application does not particularly limit the specific opening sizes of the first end 811 and the second end 812 of the flow channel hole 81, as long as the opening size of the first end 811 is smaller than that of the second end 812. For example, in Figure 12 ( Figure 12 In the embodiment shown in the top view of the thermal end assembly 100 provided in the sixth embodiment of the present application, the opening sizes of the first end 811 and the second end 812 of each flow channel hole 81 are relatively large, which can also make the inner core of the printing consumable be fully extruded and heated, while reducing the resistance of the outer layer of the printing consumable that has been melted when flowing through the flow channel hole 81.

[0079] Please see Figure 13 , Figure 13 The top view of the thermal end assembly 100 provided in the seventh embodiment of the present application.

[0080] As Figure 13As shown, in an embodiment, the number of flow channel holes 81 is multiple, and the multiple flow channel holes 81 are arranged around the outside of the center of the channel 11, and each of the flow channel holes 81 is isolated from each other. When the heat conduction block 10 heats the printing consumables in the channel 11, usually the surface layer of the printing consumables is heated first, and when the surface layer of the printing consumables is in a molten state, the inner core thereof can still be in a solid state. The present application arranges multiple flow channel holes 81 around the outside of the center of the channel 11 to ensure that the inner core of the printing consumables in a solid state does not temporarily flow into the nozzle 20, and only after being sufficiently molten to have fluid properties can it flow into the nozzle 20 from the surrounding flow channel holes 81, thereby avoiding clogging the nozzle 20.

[0081] In Figure 13 In the embodiment shown, the number of flow channel holes 81 is three, and the three flow channel holes 81 are spaced and uniformly arranged around the outside of the center of the channel 11 along the circumference of the channel 11. In Figure 14 In the embodiment shown, the number of flow channel holes 81 is four, and the four flow channel holes 81 are spaced and uniformly arranged around the outside of the center of the channel 11 along the circumference of the channel 11. In Figure 15 In the embodiment shown, the number of flow channel holes 81 is five, and the five flow channel holes 81 are spaced and uniformly arranged around the outside of the center of the channel 11 along the circumference of the channel 11.

[0082] Please see Figure 16 , Figure 16 for the cross-sectional structure of the hot end assembly 100 provided in an embodiment of the present application; Figure 17 for the structure of the protrusion 30 and the flow guide 70 provided in an embodiment of the present application.

[0083] As Figure 16 and Figure 17 shown, in an embodiment, the channel 11 of the heat conduction block 10 further comprises a flow guide 70, which is arranged on the side of the protrusion 30 away from the nozzle 20 and concentric with the channel 11 along the length direction of the channel 11. The circumferential cross-sectional area of the flow guide 70 decreases from the direction close to the protrusion 30 to the direction away from the protrusion 30. It can be understood that in this embodiment, the flow guide 70 is arranged on the side of the protrusion 30 away from the nozzle 20 to limit the flow path of the printing consumables when entering the channel 11 at the position where the protrusion 30 is arranged. Specifically, by arranging the flow guide 70 concentric with the channel 11 and making the circumferential cross-sectional area of the flow guide 70 decrease from the direction close to the protrusion 30 to the direction away from the protrusion 30, i.e. arranging the flow guide 70 as a conical structure, the flow guide 70 can strip the surface layer of the printing consumables. Or it can be understood that the conical flow guide 70 can guide the molten part of the surface layer of the printing consumables to flow into the sub-channel, thereby accelerating the melting speed of the inner core of the printing consumables.

[0084] Reference Figure 2In one embodiment, the channel 11 includes a pre-melting section 112 and a flow guiding section 113 along the length direction of the channel 11. The pre-melting section 112 is located at the side of the flow guiding section 113 away from the nozzle 20, and the protrusion 30 is arranged on the flow guiding section 113. It can be understood that the pre-melting section 112 is used to melt the surface layer of the printing consumable in advance to ensure that the printing consumable has fluid properties and can flow to the protrusion 30. The flow guiding section 113 is used to limit the flow path of the printing consumable in a molten state. Specifically, the pre-melting section 112 is arranged at the side of the flow guiding section 113 away from the nozzle 20, and the protrusion 30 is arranged on the flow guiding section 113, so that part of the printing consumable is melted in advance to facilitate the protrusion 30 to divide the printing consumable, so that the inner core of the printing consumable can be easily fully melted in the flow guiding section 113.

[0085] Please see Figure 18 and Figure 19 , wherein Figure 18 is a partial structural schematic diagram of the hot end assembly 100 provided in another embodiment of the present application; Figure 19 is a top view of the hot end assembly 100 provided in the tenth embodiment of the present application.

[0086] As shown in Figure 18 and Figure 19 , in one embodiment, the protrusion 30 is an integral structure with the channel 11. In order to facilitate the manufacture of the protrusion 30 in the channel 11, the heat conduction block 10 is arranged as a split structure. That is, the heat conduction block 10 is composed of a first sub-heat conduction block 114 and a second sub-heat conduction block 115. In manufacturing, the structure of a semicircular arc is first arranged in the first sub-heat conduction block 114, and the protrusion 30 is arranged therein, and then the second sub-heat conduction block 115 with the semicircular arc structure is covered and fixed on the first sub-heat conduction block 114 to form a complete channel 11.

[0087] Please see Figure 20 , Figure 20 is a top view of the hot end assembly 100 provided in the eleventh embodiment of the present application.

[0088] As shown in Figure 20 , in one embodiment, the cross section of each flow channel hole 81 is in the shape of a circular arc, and each flow channel hole 81 is arranged in a circumferential direction along the channel 11. It can be understood that in this embodiment, the flow channel hole 81 in the shape of a circular arc has a smaller width dimension in the radial direction of the channel 11 than the flow channel hole 81 in the shape of a circular hole in Figure 13 , and the thickness of the inner core of the printing consumable passing through the flow channel hole 81 is thinner, which is beneficial to fully melt the printing consumable.

[0089] Please see Figure 21 , Figure 21 is a structural schematic diagram of the print head 200 provided in one embodiment of the present application.

[0090] As Figure 21 shown, in one embodiment, the present application also provides a 3D printer, the 3D printer comprising a print head 200 and the hot end assembly 100 in any of the above embodiments, the hot end assembly 100 being mounted to the print head 200. The hot end assembly 100 is configured to heat the printing consumables to a molten state and deliver to the nozzle 20 on the print head 200. The print head 200 is configured to move along a preset trajectory, extrude the molten printing consumables through the nozzle 20 towards a print platform of the 3D printer, and realize 3D printing.

[0091] It should be understood that the terms "first", "second", etc. are used only for descriptive purposes and should not be construed as indicating or implying relative importance or an indicated number of the technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0092] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "illustrative embodiment", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0093] It should be understood that the application of the present application is not limited to the above examples, and those skilled in the art can make improvements or changes according to the above description, and all these improvements and changes shall belong to the protection scope of the claims of the present application. Those skilled in the art can understand that all or part of the processes of the above embodiments can be implemented, and the equivalent changes made according to the claims of the present application still belong to the scope covered by the present application.

Claims

1. A hot end assembly suitable for use in a 3D printer for providing a nozzle with molten print consumables, characterized in that, The heat dissipation member and the heat conduction block are provided with a through channel, which is communicated with the feeding port of the nozzle; the printing consumable enters the through channel through the heat dissipation member; The through channel is provided with at least one protrusion, and the printing consumable enters the nozzle through the protrusion and is extruded through the nozzle.

2. The hot end assembly of claim 1, wherein, The number of the protrusions is multiple, and the multiple protrusions are arranged in a circumferential direction of the through channel.

3. The hot end assembly of claim 2, wherein, The circumferential dimension of each protrusion gradually decreases from the inner wall of the through channel to the center of the through channel.

4. The hot end assembly of claim 1, wherein, The protrusion is an inlay, which is embedded in the inner wall of the through channel.

5. The hot end assembly of claim 4, wherein, The outer circumferential surface of the inlay is close to the inner wall of the through channel, and the inlay is provided with a flow channel hole in the middle, through which the printing consumable flows into the nozzle.

6. The hot end assembly of claim 5, wherein, The number of the flow channel holes is multiple, and the multiple flow channel holes are communicated with each other at the center of the through channel.

7. The hot end assembly of claim 6, wherein, In the direction from the inner wall of the through channel to the center of the through channel, the flow channel hole includes a first end and a second end, the second end is close to the center of the through channel, and the opening size of the second end is smaller than that of the first end.

8. The hot end assembly of claim 5, wherein, The number of the flow channel holes is multiple, and the multiple flow channel holes are isolated from each other around the center of the through channel.

9. The hot end assembly of any of claims 1-8, wherein, The through channel is further provided with a flow guide member, which is arranged on the side of the protrusion away from the nozzle and is concentric with the through channel, and in the length direction of the through channel, the circumferential cross-sectional area of the flow guide member decreases from the side close to the protrusion to the side away from the protrusion.

10. The hot end assembly of any of claims 1-8, wherein, In the length direction of the through channel, the through channel includes a pre-melting section and a flow guide section, the pre-melting section is located on the side of the flow guide section away from the nozzle, and the protrusion is arranged in the flow guide section.

11. The hot end assembly of any of claims 1-8, wherein, The nozzle is detachably connected to the heat conduction block.

12. A 3D printer characterized by, The printing head and the heat end assembly according to any one of claims 1-11 are provided, and the heat end assembly is mounted on the printing head.

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