Nozzle and 3D printer
By designing the cross-sectional area of the melt extrusion runner larger than the consumable extrusion runner in the nozzle and increasing the contact area of the runner, the problem of difficulty in extrusion of consumables is solved and the printing speed and quality are improved.
Patent Information
- Application Number
- CN202422247026.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-13
- Publication Date
- 2025-09-02
- Estimated Expiration
- 2034-09-13
AI Technical Summary
Existing nozzles cause difficulty in extruding consumables after inserting the insert, affecting printing speed and quality, especially during the pullback process, which can easily cause model wire drawing.
The nozzle structure is designed so that the cross-sectional area of the melt extrusion flow channel is greater than the cross-sectional area of the consumable extrusion flow channel, and the contact area between the consumable and the melt extrusion flow channel is increased by increasing the number of runners or changing the flow channel shape, reducing flow resistance and improving melting efficiency.
It realizes smooth flow and efficient melting of consumables, improves printing speed and quality, reduces extrusion pressure, and avoids the problem of difficulty in retraction of consumables.
Smart Images
Figure CN223290327U_ABST
Abstract
Description
Technical Field
[0001] The present application belongs to the field of 3D printing technology, and in particular relates to a nozzle and a 3D printer. Background Art
[0002] FDM (Fused Deposition Modeling) is a 3D printing method. FDM 3D printing uses thermoplastic materials, such as wax, ABS, and nylon, and is fed in filament form. The material is heated and melted within a nozzle, which then moves along the part's cross-sectional contours and fill path, extruding the melted material. The material rapidly solidifies and bonds with the surrounding material.
[0003] Currently, existing nozzles incorporate inserts to increase the melting speed of the filament. However, inserting these inserts into the nozzle creates a certain degree of pressure at the nozzle, making it difficult to expel the filament. Furthermore, during the retraction process, the inserts prevent the filament from being withdrawn upward, resulting in stringing in the model. Therefore, existing nozzle designs have a certain impact on both printing speed and quality. Summary of the Invention
[0004] Based on this, it is necessary to provide a nozzle and a 3D printer to address the above-mentioned technical problems.
[0005] The present application provides a nozzle, comprising:
[0006] A structural body, wherein a melt extrusion flow channel and a consumable extrusion flow channel are provided inside the structural body, the flow channel inlet of the melt extrusion flow channel is used to receive consumables, and the flow channel outlet of the melt extrusion flow channel is connected to the flow channel inlet of the consumable extrusion flow channel, and is used to transport consumables to the consumable extrusion flow channel; wherein the transverse flow channel cross-section of the melt extrusion flow channel is a first flow channel cross-section, and the transverse flow channel cross-section of the consumable extrusion flow channel is a second flow channel cross-section, the cross-sectional area of the inflow end of the first flow channel cross-section is greater than the cross-sectional area of the outflow end of the second flow channel cross-section, wherein the cross-sectional area of the inflow end of the first flow channel cross-section is 1.5mm 2 Up to 8mm 2 The cross-sectional area of the outflow end of the second flow channel section is between 0.1mm 2 to 0.8mm 2 between.
[0007] In one embodiment, the melt extrusion flow channel includes a plurality of unit extrusion flow channels, the flow channel outlets of the plurality of unit extrusion flow channels are interconnected, and the flow channel outlets of the plurality of unit extrusion flow channels are all connected to the flow channel inlet of the consumable extrusion flow channel; the transverse flow channel cross-section of the inlet end of the unit extrusion flow channel is the first unit flow channel cross-section, and the sum of the cross-sectional areas of all the first unit flow channel cross-sections is the cross-sectional area of the inlet end of the first flow channel cross-section.
[0008] In one embodiment, the flow channel center lines of several of the unit extrusion flow channels are inclined relative to the flow channel center line of the consumable extrusion flow channel, wherein, in the direction of gradually approaching the consumable extrusion flow channel, the flow channel center lines of several of the unit extrusion flow channels gradually approach the flow channel center line of the consumable extrusion flow channel.
[0009] In one embodiment, the inclinations of the flow channel center lines of several of the unit extrusion flow channels relative to the flow channel center line of the consumable extrusion flow channel are all equal.
[0010] In one embodiment, the flow channel center lines of several of the unit extrusion flow channels are parallel to the flow channel center line of the consumable extrusion flow channel, wherein a first transition flow channel is opened inside the structural body, and the flow channel outlets of several of the unit extrusion flow channels are connected to the flow channel inlet of the consumable extrusion flow channel through the first transition flow channel.
[0011] In one embodiment, the cross-sectional area of the transverse flow channel section of the first transition flow channel gradually decreases in a direction gradually approaching the consumable extrusion flow channel.
[0012] In one embodiment, the number of the unit extrusion flow channels is four or more, and a plurality of the unit extrusion flow channels are circumferentially distributed around the flow channel center line of the consumable extrusion flow channel.
[0013] In one embodiment, the transverse flow channel cross section of the melt extrusion flow channel is a circular cross section, wherein the cross-sectional diameter of the transverse flow channel cross section of the melt extrusion flow channel gradually decreases in the direction gradually approaching the consumable extrusion flow channel.
[0014] In one embodiment, the melt extrusion flow channel includes a central flow channel and two side flow channels symmetrically arranged on both sides of the central flow channel, and the two side flow channels are both connected to the central flow channel; the central flow channel and the consumable extrusion flow channel are both cylindrical flow channels, the transverse cross-sectional diameter of the central flow channel is larger than the transverse cross-sectional diameter of the consumable extrusion flow channel, each of the side flow channels has two inner side walls and an inner end wall, and the distance between the two inner side walls is larger than the transverse cross-sectional diameter of the central flow channel; the central flow channel is connected to the consumable extrusion flow channel through a second transition flow channel, wherein the cross-sectional area of the transverse flow channel cross section of the second transition flow channel gradually decreases in the direction of gradually approaching the consumable extrusion flow channel.
[0015] The present application provides a 3D printer, which includes the nozzle.
[0016] In the aforementioned nozzle and 3D printer, according to fluid design principles, the longer the flow channel, the greater the fluid resistance, and the larger the flow channel diameter, the lower the fluid pressure. Therefore, in the design of the aforementioned nozzle, the cross-sectional area of the first flow channel is set to be larger than the cross-sectional area of the second flow channel. This allows the filament to enter the melt extrusion channel from the flow channel inlet and flow within the melt extrusion channel. The larger cross-sectional area of the first flow channel increases the contact area between the filament and the melt extrusion channel. This increased contact area improves the melting efficiency of the filament, thereby ensuring smooth flow of the filament and avoiding technical issues such as unsmooth extrusion. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 A three-dimensional view of the nozzle provided in the first embodiment of the present application.
[0018] Figure 2 A plan view of the nozzle provided for the first embodiment of the present application.
[0019] Figure 3 This is an AA cross-sectional view of the nozzle provided in the first embodiment of the present application.
[0020] Figure 4 A top view of the nozzle provided in the first embodiment of the present application.
[0021] Figure 5 A three-dimensional view of the nozzle provided in the second embodiment of the present application.
[0022] Figure 6 A top view of the nozzle provided in the second embodiment of the present application.
[0023] Figure 7 This is a BB cross-sectional view of the nozzle provided in the second embodiment of the present application.
[0024] Figure 8A three-dimensional diagram of the nozzle provided in the third embodiment of the present application.
[0025] Figure 9 A plan view of a nozzle provided for the third embodiment of the present application.
[0026] Figure 10 This is a CC cross-sectional view of the nozzle provided in the third embodiment of the present application.
[0027] Figure 11 A top view of the nozzle provided for the third embodiment of the present application.
[0028] Figure 12 This is a first stereoscopic view of the nozzle provided in the fourth embodiment of the present application.
[0029] Figure 13 A second stereoscopic view of the nozzle provided in the fourth embodiment of the present application.
[0030] Figure 14 A top view of the nozzle provided in the fourth embodiment of the present application.
[0031] Figure 15 This is a DD cross-sectional view of the nozzle provided in the fourth embodiment of the present application.
[0032] Figure 16 EE cross-sectional view of the nozzle provided in the fourth embodiment of the present application.
[0033] Figure Number:
[0034] 1000, structural main body;
[0035] 1100, melt extrusion flow channel; 1200, consumables extrusion flow channel;
[0036] 1101. Unit extrusion channel; 1102. First transition channel; 1103. Central channel; 1104. Side channel; 1105. Second transition channel; 1106. Inner side wall; 1107. Inner end wall. DETAILED DESCRIPTION
[0037] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.
[0038] In the description of this application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.
[0039] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of this application, if the term "plurality" appears, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.
[0040] In this application, unless otherwise specified or limited, the terms "mounted," "connected," "connected," "fixed," etc., should be interpreted broadly. For example, these terms may refer to fixed connections, removable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediary; and internal communication between two components or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.
[0041] In this application, unless otherwise expressly specified or limited, if a first feature is described as being "above" or "below" a second feature, or similar descriptions, this may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is described as being "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is described as being "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.
[0042] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only embodiment.
[0043] See Figures 1 to 16 As shown, the present application provides a nozzle, which includes a structural body 1000, and a melting extrusion flow channel 1100 and a consumable extrusion flow channel 1200 are opened inside the structural body 1000. The flow channel inlet of the melting extrusion flow channel 1100 is used to receive the consumable, and the flow channel outlet of the melting extrusion flow channel 1100 is connected to the flow channel inlet of the consumable extrusion flow channel 1200, and is used to transport the consumable to the consumable extrusion flow channel 1200. Therefore, the consumable can enter from the flow channel inlet of the melting extrusion flow channel 1100, be heated and melted through the melting extrusion flow channel 1100, and then flow out from the consumable extrusion flow channel 1200 to implement printing processing.
[0044] According to the design principle of fluid, the longer the flow channel, the greater the fluid resistance, and the larger the diameter of the flow channel, the lower the fluid pressure. Therefore, in the design of the above-mentioned nozzle, the transverse flow channel section of the melt extrusion flow channel 1100 is defined as the first flow channel section, and the transverse flow channel section of the consumable extrusion flow channel 1200 is defined as the second flow channel section. At this time, the cross-sectional area of the inflow end of the first flow channel section is set to be larger than the cross-sectional area of the outflow end of the second flow channel section, so that after the consumable enters the flow channel inlet of the melt extrusion flow channel 1100, when flowing in the melt extrusion flow channel 1100, the consumable can increase the contact area with the melt extrusion flow channel 1100 based on the larger cross-sectional area of the first flow channel section. The increase in contact area can reduce the flow resistance of the consumable and improve the melting efficiency of the consumable, thereby allowing the consumable to flow smoothly. When the consumable melts and flows through the consumable extrusion flow channel 1200, it is extruded plastic based on the smaller transverse flow channel section of the consumable extrusion flow channel 1200 to implement printing.
[0045] In one embodiment, the cross-sectional area of the outflow end of the second flow channel section can be limited to have a specific design ratio with the cross-sectional area of the inflow end of the first flow channel section. For example, the design ratio can be set to 1:6, 1:7, 1:8, 1:9, 1:10, 1:11, 1:12, 1:13, etc. Alternatively, in one embodiment, the cross-sectional area of the inflow end of the first flow channel section is 1.5mm 2 Up to 8mm 2 For example, the cross-sectional area of the inflow end of the first flow channel section is 1.5 mm 2 , 1.8mm2 , 2mm 2 , 2.1mm 2 , 2.3mm 2 , 2.6mm 2 , 3mm 2 , 3.2mm 2 , 3.5mm 2 , 3.8mm 2 , 4mm 2 , 4.5mm 2 , 5mm 2 , 5.2mm 2 , 5.5mm 2 , 5.8mm 2 , 6mm 2 , 6.5mm 2 , 6.8mm 2 , 7mm 2 , 7.3mm 2 , 7.5mm 2 , 7.7mm 2 , 8mm 2 The cross-sectional area of the outflow end of the second flow channel section is 0.1mm 2 , 0.2mm 2 , 0.3mm 2 , 0.4mm 2 , 0.5mm 2 , 0.6mm 2 , 0.7mm 2 , 0.8mm 2 etc., not limited here.
[0046] Those skilled in the art can set the above-mentioned design ratio, the specific value of the cross-sectional area of the inlet end of the above-mentioned first flow channel cross-section, and the specific value of the cross-sectional area of the outflow end of the second flow channel cross-section according to actual needs, so as to form a sufficient contact area with the melted extrusion flow channel 1100 in the melted extrusion flow channel 1100 before the melted consumable enters the consumable extrusion flow channel 1200, thereby reducing the flow resistance of the consumable.
[0047] The melt extrusion flow channel 1100 can increase the cross-sectional area through various design methods, thereby increasing the contact area between the consumable and the melt extrusion flow channel 1100. For example, the melt extrusion flow channel 1100 can increase the contact area between the consumable and the melt extrusion flow channel 1100 by increasing the number of flow channels and changing the flow channel shape. Figures 1 to 7As shown, in one embodiment, the melting extrusion flow channel 1100 can be designed to include a plurality of unit extrusion flow channels 1101, the flow channel outlets of the plurality of unit extrusion flow channels 1101 are interconnected, and the flow channel outlets of the plurality of unit extrusion flow channels 1101 are all connected to the flow channel inlet of the consumable extrusion flow channel 1200; the transverse flow channel cross-section of the inlet end of the unit extrusion flow channel 1101 is the first unit flow channel cross-section, and the sum of the cross-sectional areas of all the first unit flow channel cross-sections is the cross-sectional area of the inlet end of the first flow channel cross-section.
[0048] At this time, the consumable can enter each unit extrusion flow channel 1101 from the flow channel inlet of the several unit extrusion flow channels 1101, and then flow along the several unit extrusion flow channels 1101 at the same time. When flowing in the several unit extrusion flow channels 1101, the contact area between the consumable and the several unit extrusion flow channels 1101 can be greatly increased. Not only can the flow resistance of the consumable be reduced based on the increase in contact area, thereby allowing the consumable to flow smoothly, but the increase in contact area can also improve the melting efficiency, making the heating and melting of the consumable more sufficient, thereby achieving rapid melting.
[0049] The number of unit extrusion flow channels 1101 can be designed to be more than four, and several unit extrusion flow channels 1101 are circumferentially distributed around the flow channel center line of the consumable extrusion flow channel 1200. When the number of unit extrusion flow channels 1101 is four, the melting efficiency can be roughly improved by about 35% compared with traditional nozzles. As the number of unit extrusion flow channels 1101 increases, the melting efficiency can also be improved accordingly. Those skilled in the art can set the number of unit extrusion flow channels 1101 according to actual needs, so as to reduce the flow resistance of the consumables and improve the melting efficiency as needed, which is not limited here.
[0050] like Figures 1 to 4 As shown in the embodiments, in one of the embodiments, the flow channel center lines of several unit extrusion flow channels 1101 are all inclined relative to the flow channel center line of the consumable extrusion flow channel 1200, wherein, in the direction gradually approaching the consumable extrusion flow channel 1200, the flow channel center lines of several unit extrusion flow channels 1101 are all gradually approaching the flow channel center line of the consumable extrusion flow channel 1200. The inclination angle of the flow channel center line of several unit extrusion flow channels 1101 relative to the flow channel center line of the consumable extrusion flow channel 1200 can be adjusted as needed, for example, the inclination angle can be set to 15°, 20°, 25°, 30° and the like, and in one of the embodiments, the inclination of the flow channel center line of several unit extrusion flow channels 1101 relative to the flow channel center line of the consumable extrusion flow channel 1200 can be equal, or each inclination angle can be designed independently, which is not limited here.
[0051] like Figures 5 to 7As shown in the embodiment, in one embodiment, the flow channel center lines of the plurality of unit extrusion flow channels 1101 can also be parallel to the flow channel center line of the consumable extrusion flow channel 1200. The parallel design is compared with the above Figures 1 to 4 For the embodiment shown, the flow resistance can be further reduced. At this time, a first transition channel 1102 is opened inside the structural main body 1000, and the channel outlets of the multiple unit extrusion channels 1101 are connected to the channel inlet of the consumable extrusion channel 1200 through the first transition channel 1102. After the consumables are melted in the multiple unit extrusion channels 1101, they can first be concentrated in the first transition channel 1102 and then enter the consumable extrusion channel 1200. In one embodiment, the cross-sectional area of the transverse channel section of the first transition channel 1102 gradually decreases in the direction approaching the consumable extrusion channel 1200. For example, the first transition channel 1102 can be designed as a conical channel space shape.
[0052] like Figures 8 to 11 As shown in the embodiment, in one of the embodiments, the transverse flow channel cross-section of the melt extrusion flow channel 1100 is a circular cross-section, wherein the cross-sectional diameter of the transverse flow channel cross-section of the melt extrusion flow channel 1100 gradually decreases in the direction gradually approaching the consumable extrusion flow channel 1200. Therefore, in addition to increasing the number of flow channels, in this embodiment, the contact area between the consumable and the melt extrusion flow channel 1100 can also be increased by changing the shape of the flow channel. At this time, the melt extrusion flow channel 1100 can be in the shape of a conical flow channel space. After the consumable enters the flow channel inlet of the melt extrusion flow channel 1100, the consumable can gradually contact the conical inner wall surface of the melt extrusion flow channel 1100. In this way, the contact area between the consumable and the melt extrusion flow channel 1100 is increased, thereby reducing the flow channel pressure.
[0053] like Figures 12 to 16 As shown in the embodiment, in one embodiment, the melt extrusion flow channel 1100 includes a central flow channel 1103 and two side flow channels 1104 symmetrically arranged on both sides of the central flow channel 1103. The two side flow channels 1104 are both connected to the central flow channel 1103. Each side flow channel 1104 has two relatively parallel inner side walls 1106 and an inner end wall 1107 perpendicularly connected to the two inner side walls 1106. The inner ends of the two inner side walls 1106 are connected to the central flow channel 1103, thereby making the side flow channels 1104 connected to the central flow channel 1103. The addition of the two side flow channels 1104 can increase the cross-sectional area of the consumables entering the melt extrusion flow channel 1100, thereby increasing the contact area between the consumables and the melt extrusion flow channel 1100.
[0054] Continue reading Figures 12 to 16The central flow channel 1103 and the consumable extrusion flow channel 1200 are both cylindrical flow channels, the transverse cross-sectional diameter of the central flow channel 1103 is larger than the transverse cross-sectional diameter of the consumable extrusion flow channel 1200, and the distance between the two inner walls 1106 is larger than the transverse cross-sectional diameter of the central flow channel 1103; the central flow channel 1103 is connected to the consumable extrusion flow channel 1200 through the second transition flow channel 1105, wherein, in the direction of gradually approaching the consumable extrusion flow channel 1200, the cross-sectional area of the transverse flow channel section of the second transition flow channel 1105 gradually decreases.
[0055] It can be seen from this that in the above-mentioned multiple embodiments, the consumables can all enter from the flow channel inlet of the melting and extrusion flow channel 1100, and the consumables can be heated and melted in the melting and extrusion flow channel 1100. Based on the above-mentioned multiple embodiments, after the contact area between the consumables and the melting and extrusion flow channel 1100 is increased, the thermal conductivity efficiency can be increased, the melting effect can be improved, the flow resistance of the consumables can be reduced, and the extrusion of the consumables can be smoother.
[0056] When the required melting effect is the same, the flow channel length of the consumable extrusion flow channel 1200 can be shortened appropriately, thereby reducing the extrusion pressure of the consumable and increasing the extrusion rate of the consumable. According to experiments, reducing the flow channel length of the consumable extrusion flow channel 1200, thereby reducing the extrusion pressure of the consumable, can increase the extrusion efficiency of the consumable by 20%. The above-mentioned nozzle can be manufactured in an integrated molding manner, thereby improving the heat transfer efficiency. No insert is required inside the nozzle. When the insert is not provided, there is no need for secondary assembly of the insert when using or assembling the nozzle, thereby reducing the cumbersomeness of use by avoiding secondary assembly, and is also conducive to the withdrawal of consumables.
[0057] This application provides a 3D printer, which includes a nozzle. Since the specific structure, functional principles, and technical effects of the nozzle are described in detail above, they will not be repeated here. Any technical content related to the nozzle can be referenced in the above description.
[0058] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0059] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.
Claims
1. A nozzle, characterized in that: The nozzle comprises: A structural body, wherein a melting extrusion flow channel and a consumable extrusion flow channel are provided inside the structural body, the flow channel inlet of the melting extrusion flow channel is used to receive consumables, and the flow channel outlet of the melting extrusion flow channel is connected to the flow channel inlet of the consumable extrusion flow channel, and is used to transport consumables to the consumable extrusion flow channel; wherein the transverse flow channel cross-section of the melting extrusion flow channel is a first flow channel cross-section, and the transverse flow channel cross-section of the consumable extrusion flow channel is a second flow channel cross-section, the cross-sectional area of the inflow end of the first flow channel cross-section is greater than the cross-sectional area of the outflow end of the second flow channel cross-section, wherein the cross-sectional area of the inflow end of the first flow channel cross-section is 1.5mm 2 Up to 8mm 2 The cross-sectional area of the outflow end of the second flow channel section is between 0.1mm 2 to 0.8mm 2 between.
2. The nozzle according to claim 1, characterized in that The melt extrusion flow channel includes several unit extrusion flow channels, the flow channel outlets of several unit extrusion flow channels are connected to each other, and the flow channel outlets of several unit extrusion flow channels are all connected to the flow channel inlet of the consumable extrusion flow channel; the transverse flow channel section of the inflow end of the unit extrusion flow channel is the first unit flow channel section, and the sum of the cross-sectional areas of all the first unit flow channel sections is the cross-sectional area of the inflow end of the first flow channel section.
3. The nozzle according to claim 2, characterized in that The flow channel center lines of several of the unit extrusion flow channels are inclined relative to the flow channel center line of the consumable extrusion flow channel, wherein, in the direction of gradually approaching the consumable extrusion flow channel, the flow channel center lines of several of the unit extrusion flow channels gradually approach the flow channel center line of the consumable extrusion flow channel.
4. The nozzle according to claim 3, characterized in that The inclinations of the flow channel center lines of the plurality of unit extrusion flow channels relative to the flow channel center line of the consumable extrusion flow channel are all equal.
5. The nozzle according to claim 2, characterized in that The flow channel center lines of several of the unit extrusion flow channels are parallel to the flow channel center line of the consumable extrusion flow channel, wherein a first transition flow channel is opened inside the structural body, and the flow channel outlets of several of the unit extrusion flow channels are connected to the flow channel inlet of the consumable extrusion flow channel through the first transition flow channel.
6. The nozzle according to claim 5, characterized in that In a direction gradually approaching the consumable extrusion flow channel, the cross-sectional area of the transverse flow channel cross section of the first transition flow channel gradually decreases.
7. The nozzle according to any one of claims 2 to 6, characterized in that The number of the unit extrusion flow channels is four or more, and a plurality of the unit extrusion flow channels are circumferentially distributed around the flow channel center line of the consumable extrusion flow channel.
8. The nozzle according to claim 1, wherein The transverse flow channel cross section of the melt extrusion flow channel is a circular cross section, wherein the cross-sectional diameter of the transverse flow channel cross section of the melt extrusion flow channel gradually decreases in the direction gradually approaching the consumable extrusion flow channel.
9. The nozzle according to claim 1, wherein The melt extrusion flow channel includes a central flow channel and two side flow channels symmetrically arranged on both sides of the central flow channel, and the two side flow channels are both connected to the central flow channel; the central flow channel and the consumable extrusion flow channel are both cylindrical flow channels, the transverse cross-sectional diameter of the central flow channel is larger than the transverse cross-sectional diameter of the consumable extrusion flow channel, each of the side flow channels has two inner side walls and an inner end wall, and the distance between the two inner side walls is larger than the transverse cross-sectional diameter of the central flow channel; the central flow channel is connected to the consumable extrusion flow channel through a second transition flow channel, wherein the cross-sectional area of the transverse flow channel cross section of the second transition flow channel gradually decreases in the direction of gradually approaching the consumable extrusion flow channel.
10. A 3D printer, characterized in that: The 3D printer comprises the nozzle according to any one of claims 1 to 9.