Material extrusion device, 3D printer and printing method

Abstract

The embodiment of the invention relates to the technical field of 3D printing, and discloses a material extrusion device and a 3D printer, the material extrusion device comprises a first extrusion mechanism and at least two second extrusion mechanisms; the first extrusion mechanism comprises a first charging barrel, a first motor and a first screw, the first motor is arranged at one end of the first charging barrel, a nozzle is arranged at the other end of the first charging barrel, the first screw is arranged in the first charging barrel, and one end of the first screw is connected with the first motor; each second extrusion mechanism comprises a second charging barrel, a storage bin, a second motor, a second screw rod and a feeding bin, the two ends of the second charging barrel communicate with the first charging barrel and the storage bin correspondingly, the storage bin is provided with the second motor and further communicates with the feeding bin, the second screw rod is arranged in the second charging barrel, and the second screw rod is arranged in the second charging barrel. And one end of the second screw rod penetrates through the storage bin and is connected with a second motor. By means of the mode, mixing and extrusion of at least two materials are achieved, and the 3D printer achieves mixed printing of multiple materials of the same product.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of 3D printing technology, and specifically to a material extrusion device, a 3D printer, and a printing method. Background Art

[0002] A 3D printer is a rapid prototyping additive manufacturing device. It is a technology that uses digital model files as the basis and uses granular or filamentary plastics and other bondable materials to construct objects by printing layer by layer. Common technologies include Fused Deposition Modeling (FDM), Selective Laser Sintering (SLS), Stereo Lithography Appearance (SLA), etc. At present, the extruder head of a 3D printer that uses melt extrusion can only perform melt extrusion of one material, and cannot achieve multi-material fusion extrusion of the same product, resulting in the 3D printer being able to only use a single material to print products. Summary of the invention

[0003] In view of the above problems, the embodiments of the present application provide a material extrusion device, a 3D printer and a printing method, which can achieve the mixing and extrusion of at least two materials, so that the 3D printer can achieve mixed printing of multiple materials for the same product.

[0004] According to one aspect of an embodiment of the present application, a material extrusion device for a 3D printer is provided, the material extrusion device comprising: a first extrusion mechanism and at least two second extrusion mechanisms; the first extrusion mechanism comprises a first barrel, a first motor and a first screw, one end of the first barrel is provided with a first motor, and the other end is provided with a nozzle, the first screw is arranged in the first barrel, and one end of the first screw is connected to the first motor; each second extrusion mechanism comprises a second barrel, a storage bin, a second motor, a second screw and a feed bin, and in each second extrusion mechanism, both ends of the second barrel are separately The second motor is used to drive the second screw to rotate so as to squeeze the material stored in the storage bin into the second barrel, and to extrude the material in the second barrel into the first barrel; the first screw is used to mix the materials squeezed into the first barrel from different extrusion mechanisms and extrude them through the nozzle.

[0005] In an optional manner, in each second extrusion mechanism, a dimension of the storage bin along the radial direction of the second screw is greater than a dimension of the second barrel along the radial direction of the second screw.

[0006] In an optional manner, in each second extrusion mechanism, a funnel structure is provided at a position in the second barrel connected to the storage bin, and a material guide notch is provided on the wall at the lower opening of the funnel structure, and the slope of the material guide notch is greater than the slope of the funnel structure.

[0007] In an optional manner, each feed bin is used to input different materials, and each second screw is used to rotate at a different speed under the drive of the corresponding second motor, so as to extrude the material stored in the corresponding storage bin into the corresponding second barrel at different rates, and extrude the material in the corresponding second barrel into the first barrel at different rates, so that the first screw mixes and extrude the materials squeezed into the different second barrels in the first barrel in a predetermined proportion.

[0008] In an optional manner, the two second extrusion mechanisms are symmetrically arranged on both sides of the first extrusion mechanism, and the two second extrusion mechanisms and the first extrusion mechanism together form a Y-shaped structure; in each second extrusion mechanism, the feed bin is arranged on the side of the storage bin facing the first extrusion mechanism, and the shape of the feed bin is adapted to the gap between the first extrusion mechanism, the storage bin and the second motor.

[0009] In an optional manner, in each second extrusion mechanism, the volume of the feed bin is greater than the volume of the storage bin.

[0010] In an optional manner, the first extrusion mechanism also includes a mounting member, the first motor is connected to the first barrel via the mounting member, and the output shaft of the first motor passes through the mounting member and is connected to the first screw; the mounting member is also used to connect to the 3D printer body to fix the material extrusion device on the 3D printer body.

[0011] In an optional manner, the material extrusion device also includes a first heating element and at least two second heating elements, the first heating element is arranged on the first barrel for heating the mixed material in the first barrel, and the second heating element is arranged on the second barrel for heating the material in the second barrel.

[0012] In an optional manner, the first barrel is provided with a protrusion protruding outward, the second barrel is connected to the protrusion, and the protrusion is provided with channels respectively connected to the first barrel and the second barrel, and the channels are used for allowing material extruded from the second barrel to enter the first barrel.

[0013] According to another aspect of the embodiments of the present application, a 3D printer is provided, which includes a 3D printer body and a material extrusion device provided in any one of the above embodiments, wherein the material extrusion device is fixedly connected to the 3D printer body.

[0014] According to another aspect of an embodiment of the present application, a printing method is provided, which is applied to a material extrusion device provided in any one of the above embodiments, and the printing method includes: obtaining a printing ratio; determining a speed ratio between multiple second motors according to the printing ratio; controlling the multiple second motors to operate at the speed ratio and drive the corresponding second screws to rotate, so that the first screw mixes the materials extruded between the multiple second screws according to the printing ratio and extrude them for printing.

[0015] In an optional manner, the printing ratio includes a first printing ratio and a second printing ratio, the first printing ratio corresponds to the first printing interval, and the second printing ratio corresponds to the second printing interval; the speed ratio between the multiple second motors is determined according to the printing ratio; the multiple second motors are controlled to operate at the speed ratio and drive the corresponding second screws to rotate, further including: determining the speed ratio between the multiple second motors in the first printing interval according to the first printing ratio, and determining the speed ratio between the multiple second motors in the second printing interval according to the second printing ratio; within the first printing interval, the multiple second motors are controlled to operate at the speed ratio corresponding to the first printing interval and drive the corresponding second screws to rotate, so that the first screw mixes the materials squeezed into the multiple second screws according to the first printing ratio and extrude them for printing; within the second printing interval, the multiple second motors are controlled to operate at the speed ratio corresponding to the second printing interval and drive the corresponding second screws to rotate, so that the first screw mixes the materials squeezed into the multiple second screws according to the second printing ratio and extrude them for printing.

[0016] In an optional manner, a printing ratio is obtained; a speed ratio between multiple second motors is determined according to the printing ratio; and the multiple second motors are controlled to operate at the speed ratio and drive the corresponding second screws to rotate, further including: obtaining the printing ratio and the total number of intervals, wherein the printing ratio includes a starting printing ratio and a final printing ratio, the starting printing ratio corresponds to the first printing interval, and the final printing ratio corresponds to the last printing interval; a starting speed ratio of each second motor is determined according to the starting printing ratio, and a final speed ratio of each second motor is determined according to the final printing ratio; a speed ratio change between two adjacent printing intervals of each second motor is determined according to the starting speed ratio, the final speed ratio and the total number of intervals; a speed ratio corresponding to each printing interval between the multiple second motors is determined according to the starting speed ratio and the speed ratio change; in each printing interval, the multiple second motors are controlled to operate at the speed ratio corresponding to the printing interval and drive the corresponding second screws to rotate, so that the first screw mixes and extrude the materials squeezed into the multiple second screws according to the printing ratio corresponding to the printing interval for printing.

[0017] The material extrusion device provided in the embodiment of the present application, in each second extrusion mechanism, by providing a storage bin and connecting the storage bin with the feed bin, the storage bin can store materials input from the feed bin; by connecting the two ends of the second barrel with one end of the storage bin and the first barrel respectively, and connecting the second screw with a second motor provided at the other end of the storage bin, the second screw can be driven by the second motor to rotate in the second barrel, and the material stored in the storage bin is squeezed into the second barrel, and then extruded into the first barrel; by connecting the first motor provided at one end of the first barrel with one end of the first screw, the first screw can be driven by the first motor to rotate in the first barrel, and the materials extruded by each second extrusion mechanism are mixed and extruded through a nozzle provided at the other end of the first barrel for printing. In the above manner, by inputting different materials into the feed bin of each second extrusion mechanism respectively, the first screw can mix and extrude at least two materials extruded by the first extrusion mechanism, thereby realizing the multi-material mixed printing function of the same product of the 3D printer, and by setting up a storage bin to store the materials input from the feed bin, it can be ensured that there is still material extruded by the second extrusion mechanism into the first extrusion mechanism in a short time without material input, so that the first extrusion mechanism can extrude materials for printing uninterruptedly, thereby ensuring the printing quality of the 3D model.

[0018] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0020] Figure 1 A schematic diagram of the structure of a material extrusion device provided in an embodiment of the present application;

[0021] Figure 2 A cross-sectional view of a material extrusion device provided in an embodiment of the present application;

[0022] Figure 3 A schematic diagram of the structure of a material extrusion device provided in an embodiment of the present application;

[0023] Figure 4 A top view of the second barrel provided in an embodiment of the present application;

[0024] Figure 5 A schematic diagram of a printing method according to an embodiment of the present invention;

[0025] Figure 6 A schematic diagram of a printing method according to an embodiment of the present invention;

[0026] Figure 7 A flowchart of a printing method provided in an embodiment of the present application.

[0027] The reference numerals in the specific implementation manner are as follows:

[0028] 10. Material extrusion device;

[0029] 100, first extrusion mechanism; 110, first barrel; 111, mounting flange; 112, bump; 1121, channel; 120, first motor; 121, coupling; 130, first screw; 140, nozzle; 150, mounting piece; 200, second extrusion mechanism; 210, second barrel; 211, funnel structure; 2111, material guide notch; 220, storage bin; 230, second motor; 240, second screw; 250, feed bin; 300, first heating element; 400, second heating element. DETAILED DESCRIPTION

[0030] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0032] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0033] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0034] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists, A and B exist at the same time, and B exists. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0035] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0036] In the description of the embodiments of the present application, the technical 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. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0037] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0038] A 3D printer is a rapid prototyping additive manufacturing device. It is a technology that uses digital model files as the basis and uses granular or filamentary plastics and other bondable materials to construct objects by printing layer by layer. At present, the extruder head of a melt extrusion 3D printer is mainly designed with a single hopper feed and single screw extrusion, which can only perform melt extrusion of one material, resulting in the 3D printer being able to print products using only a single material, and unable to achieve multi-material fusion printing of the same product.

[0039] In order to solve the above problems, a material extrusion device can be set up with at least two feeding bins feeding at least two feeding screws respectively. Then, at least two feeding screws are set up to feed one extrusion screw respectively, so that the extrusion screw can mix the feeds of at least two feeding screws and then extrude them. By feeding one material respectively through at least two feeding screws, the material extrusion device can achieve mixing and extrusion of at least two materials, so that the 3D printer can achieve mixed printing of multiple materials for the same product.

[0040] In the above scheme, in order to improve the feeding efficiency, a feed bin is usually connected to a barrel of a built-in feed screw so that the feed screw can be fed directly through the feed bin. However, in actual operation, if the material is manually input into the feed bin, it is easy for the material to not be input into the feed bin in time, resulting in the material extrusion device being unable to continuously extrude the material for printing. On the other hand, when an automated feeding system is used to input material into the feed bin, once the feeding machine encounters a brief failure, it also faces the risk of a brief interruption in material supply. This untimely material replenishment will also interfere with the stability of the material extrusion device in extruding the material, resulting in a decrease in the quality of the 3D model printed by the 3D printer.

[0041] Based on this, the present application provides a material extrusion device, which provides a storage bin connected to the barrel on the barrel with a built-in feeding screw, and the storage bin is connected to the feeding bin, so that the storage bin can store materials input through the feeding bin, so that when there is no material input into the feeding bin for a short time, the material stored in the storage bin can supply the feeding screw for a short time, ensuring the continuity of the feeding of the feeding screw to the extrusion screw, so that the material extrusion device can continuously extrude material for printing, thereby ensuring the printing quality of the 3D model.

[0042] See also Figure 1 and Figure 2 , Figure 1 The schematic diagram of the structure of the material extrusion device provided in the embodiment of the present application is shown. Figure 2 The cross-sectional view of the material extrusion device provided in the embodiment of the present application is shown, and the material extrusion device is used in a 3D printer as a material extrusion head of the 3D printer to print a 3D model. As shown in the figure, the material extrusion device 10 includes a first extrusion mechanism 100 and at least two second extrusion mechanisms 200.

[0043] The first extrusion mechanism 100 includes a first barrel 110 , a first motor 120 and a first screw 130 . The first motor 120 is disposed at one end of the first barrel 110 , and a nozzle 140 is disposed at the other end. The first screw 130 is disposed in the first barrel 110 , and one end of the first screw 130 is connected to the first motor 120 .

[0044] Each second extrusion mechanism 200 includes a second barrel 210, a storage bin 220, a second motor 230, a second screw 240 and a feed bin 250. In each second extrusion mechanism 200, the two ends of the second barrel 210 are respectively connected to the first barrel 110 and one end of the storage bin 220, the other end of the storage bin 220 is provided with a second motor 230, and the storage bin 220 is also connected to the feed bin 250. The second screw 240 is arranged in the second barrel 210, and one end of the second screw 240 passes through the storage bin 220 and is connected to the second motor 230.

[0045] In each second extrusion mechanism 200, the storage bin 220 is used to store the material input from the feed bin 250, and the second motor 230 is used to drive the second screw 240 to rotate so as to squeeze the material stored in the storage bin 220 into the second barrel 210, and extrude the material in the second barrel 210 into the first barrel 110. The first screw 130 is used to mix the materials squeezed into the first barrel 110 from different extrusion mechanisms and extrude them through the nozzle 140.

[0046] Specifically, a mounting flange may be provided at one end of the first barrel 110 , and the first motor 120 may be fixedly provided at one end of the first barrel 110 through the mounting flange.

[0047] like Figure 2 As shown, in order to extrude the material in the first barrel 110 through the nozzle 140 for printing, a first screw 130 is arranged in the first barrel 110, and as shown in FIG. Figure 3 As shown, the output shaft of the first motor 120 is fixedly connected to one end of the first screw 130 through the coupling 121, so that when the first motor 120 is running, it can drive the first screw 130 to rotate in the first barrel 110 through the coupling 121, and transfer the material in the first barrel 110 to the nozzle 140 and extrude it through the nozzle 140.

[0048] The number of the second extrusion mechanisms 200 can be 2, 3, 4 or even more than 4, and each second extrusion mechanism 200 is arranged on the side of the first extrusion mechanism 100. The figure only takes the arrangement of two second extrusion mechanisms 200 as an example for illustration, which does not constitute a limitation.

[0049] In the embodiment of the present application, one side of the storage bin 220 can be threadedly connected to the feed bin 250, and the storage bin 220 is connected to the feed bin 250, so that the storage bin 220 can receive and store the material input from the feed bin 250. One end of the storage bin 220 is connected to one end of the second barrel 210, and one end of the second barrel 210 is connected to the first barrel 110, so that the storage bin 220 can temporarily store the material input from the feed bin 250, and the material stored in the storage bin 220 can be supplied to the second barrel 210, so that the material in the second barrel 210 can be transferred to the first barrel 110.

[0050] Specifically, in order to supply the material stored in the storage bin 220 to the second barrel 210, a second screw 240 is disposed in the second barrel 210, and Figure 3 As shown, the output shaft of the second motor 230 is fixedly connected to one end of the second screw 240 through the coupling 121, so that when the second motor 230 is running, it can drive the second screw 240 to rotate in the second barrel 210 through the coupling 121. The thread groove provided on the second screw 240 extends into the storage bin 220, so that the second screw 240 can transfer the material in the storage bin 220 to the second barrel 210 when rotating, and extrude the material in the second barrel 210 into the first barrel 110.

[0051] Specifically, the second motor 230 can be as follows Figure 1As shown, it is fixedly arranged at one end of the storage bin 220 by the mounting flange 111. For example, threaded holes can be opened on the second motor 230 and the mounting flange 111, and the second motor 230 is threadedly connected to the mounting flange 111 by threaded fasteners. In addition, threaded holes are opened on the storage bin 220 and the mounting flange 111, and then the storage bin 220 is threadedly connected to the mounting flange 111 by threaded fasteners, so that the second motor 230 is installed and fixed on the storage bin 220.

[0052] Among them, the storage bin 220 is a cavity structure with sufficient space to store the materials input from the feed bin 250. Even if the input of materials to the feed bin 250 is stopped for a short time, the materials stored in the storage bin 220 can continue to be squeezed into the second barrel 210 by the second screw 240, ensuring that the second extrusion mechanism 200 can continue to extrude materials into the first extrusion mechanism 100 in a short time without material input, so that the first extrusion mechanism 100 can continue to extrude the mixed material through the nozzle 140 for printing, ensuring the normal progress of the printing work.

[0053] In the embodiment of the present application, the materials input into each feed bin 250 may be the same or different. For example, material A may be input into the feed bins 250 of the two second extrusion mechanisms 200. When the second screws 240 of the two second extrusion mechanisms 200 extrude material A from the second barrel 210 into the first barrel 110, the first screw 130 mixes the materials A extruded by the two second extrusion mechanisms 200 and conveys the material A to the nozzle 140, which extrude material A. Alternatively, material A may be input into the feed bin 250 of one of the first extrusion mechanisms 100 and into the feed bin 250 of the other first extrusion mechanism 100. 00 inputs material B into the feed bin 250, when the second screw 240 of one of the second extrusion mechanisms 200 extrude material A from the corresponding second barrel 210 into the first barrel 110, and the second screw 240 of the other second extrusion mechanism 200 extrude material B from the corresponding second barrel 210 into the first barrel 110, the first screw 130 mixes material A and material B in the first barrel 110, and conveys the mixed mixture to the nozzle 140, and the nozzle 140 extrude the mixture.

[0054] In some embodiments, the radial dimension of the storage bin 220 of each second extrusion mechanism 200 along the second screw 240 can be larger than the radial dimension of the second barrel 210 along the second screw 240. In this case, the material input from the feed bin 250 to the storage bin 220 can cover the connection between the storage bin 220 and the second barrel 210, and can be squeezed into the second barrel 210 by the second screw 240 in a timely manner to ensure the continuity of the second screw 240 squeezing the material into the second barrel 210, thereby ensuring the continuity of the second extrusion mechanism 200 supplying the first extrusion mechanism 100.

[0055] In some embodiments, the volume of the feed bin 250 can be larger than the volume of the storage bin 220, which not only enables more materials to be input into the feed bin 250 at one time, but also, when the storage bin 220 stores sufficient materials, the feed bin 250 can temporarily store more materials without the need to continuously input materials. This can ensure that the mixed material extruded by the material extrusion device 10 is uninterrupted and used for printing, while leaving the operator with sufficient time to replenish materials.

[0056] The material extrusion device 10 provided in the embodiment of the present application, in each second extrusion mechanism 200, by providing a storage bin 220, and connecting the storage bin 220 with the feed bin 250, so that the storage bin 220 can store the material input from the feed bin 250; by connecting the two ends of the second barrel 210 with one end of the storage bin 220 and the first barrel 110 respectively, and connecting the second screw 240 with the second motor 230 provided at the other end of the storage bin 220, so that the second screw 240 can be connected to the second motor 230 The first extruder 200 is driven by the first motor 120 to rotate in the second barrel 210, and the material stored in the storage bin 220 is squeezed into the second barrel 210, and then extruded into the first barrel 110; by connecting the first motor 120 provided at one end of the first barrel 110 with one end of the first screw 130, the first screw 130 can be driven by the first motor 120 to rotate in the first barrel 110, and the materials extruded by each second extrusion mechanism 200 are mixed and extruded through the nozzle 140 provided at the other end of the first barrel 110 for printing. In the above manner, by respectively inputting different materials into the feed bin 250 of each second extrusion mechanism 200, the first screw 130 can mix and extrude at least two materials extruded by the first extrusion mechanism 100, thereby realizing the multi-material mixed printing function of the same product of the 3D printer, and by setting up a storage bin 220 to store the materials input from the feed bin 250, it can be ensured that there is still material extruded by the second extrusion mechanism 200 into the first extrusion mechanism 100 in a short time without material input, so that the first extrusion mechanism 100 can extrude materials for printing uninterruptedly, thereby ensuring the printing quality of the 3D model.

[0057] In order to make it easier for the material stored in the storage bin 220 to be squeezed into the second barrel 210, the present application further proposes an implementation method, please continue to refer to Figure 2 , and combined with Figure 4 , Figure 4A top view of the second barrel provided in an embodiment of the present application is shown. As shown in the figure, in each second extrusion mechanism 200, a funnel structure 211 is provided at a position in the second barrel 210 that is connected to the material storage bin 220. The funnel structure 211 is provided with a material guide notch 2111 on the wall at the lower opening. The slope of the material guide notch 2111 is greater than the slope of the funnel structure 211.

[0058] By setting up the funnel structure 211, the material input from the feed bin 250 can be gathered at the lower mouth of the funnel structure 211, that is, around the second screw 240, under the guiding effect of the funnel structure 211, so that the material stored in the storage bin 220 can be squeezed into the second barrel 210 under the rotation of the second screw 240, thereby avoiding the accumulation of material in the inner cavity of the storage bin 220.

[0059] Among them, a material guide notch 2111 can be set on the wall at the lower opening, or Figure 4 As shown, two material guide notches 2111 are symmetrically arranged on the wall at the lower opening. By providing the material guide notches 2111 with a larger slope on the wall at the lower opening of the funnel structure 211, the material in the storage bin 220 can be more quickly directed to the vicinity of the second screw 240, making it easier for the second screw 240 to squeeze the material at the funnel structure 211 into the second barrel 210, rather than accumulating at the lower opening of the funnel structure 211, so that the material flows more quickly to the vicinity of the second screw 240.

[0060] When printing a model using the material extruded by the material extrusion device 10, selecting and mixing materials in different proportions to improve the hardness and toughness of the model can optimize the performance of the model. Alternatively, selecting and mixing a certain proportion of low-cost materials can reduce costs while ensuring the performance of the model.

[0061] Based on the above situation, in order to enable the material extrusion device 10 to extrude mixed materials of different proportions, the present application further proposes an implementation method, please continue to refer to Figure 1 and Figure 2 As shown in the figure, each feed bin 250 is used to input different materials, and each second screw 240 is used to rotate at a different speed under the drive of the corresponding second motor 230, so as to extrude the material stored in the corresponding storage bin 220 into the corresponding second barrel 210 at different rates, and extrude the material in the corresponding second barrel 210 into the first barrel 110 at different rates, so that the first screw 130 mixes and extrude the materials squeezed into from different second barrels 210 in the first barrel 110 in a predetermined proportion.

[0062] Since the second motors 230 of the two second extrusion mechanisms 200 are controlled to run at different speeds, the corresponding second screws 240 can be controlled to rotate at different speeds and extrude the materials into the first barrel 110 at different rates, so that the first screw 130 can mix and extrude materials of different proportions. Therefore, by controlling the second motor 230 to run at a predetermined speed, the material extrusion amount of the second extrusion mechanism 200 can be controlled, and then the first extrusion mechanism 100 can be controlled to extrude a predetermined proportion of mixed materials.

[0063] Specifically, different materials are input into the two feed bins 250 respectively, for example, material A is input into one of the feed bins 250, and material B is input into the other feed bin 250, and one of the second motors 230 is controlled to run at a speed a, and the other second motor 230 is controlled to run at a speed b, then the two second screws 240 rotate at speeds a and b, respectively, and then the second screw 240 rotating at speed a squeezes the material A stored in the storage bin 220 into the corresponding second barrel 210 at a speed a, and The material A in the second barrel 210 is extruded into the first barrel 110 at a rate a, and the second screw 240 rotating at a speed a squeezes the material B stored in the storage bin 220 into the corresponding second barrel 210 at a rate b, and extrude the material B in the second barrel 210 into the first barrel 110 at a rate b, so that the first screw 130 mixes the material A and the material B in the first barrel 110 in a ratio of a:b, and delivers the mixed material to the nozzle 140, which is extruded by the nozzle 140 for printing.

[0064] By controlling the material types input into different second extrusion mechanisms 200, and by respectively controlling the second motor 230 of each second extrusion mechanism 200 to run at different speeds, the material extrusion device 10 can be controlled to achieve mixing and extrusion of different materials and different proportions, so that during the printing process, the rotation speed of the motor can be controlled to achieve dynamic adjustment of the mixing of materials in different proportions, so as to extrude mixed materials in different proportions for printing models, and then the performance of the model can be improved or the printing cost can be reduced by configuring the proportion of the materials.

[0065] In order to reduce the volume of the material extrusion device 10 and maximize the volume of the feed bin 250, the present application further proposes an implementation method, please continue to refer to Figure 1 As shown in the figure, the two second extrusion mechanisms 200 are symmetrically arranged on both sides of the first extrusion mechanism 100, and the two second extrusion mechanisms 200 and the first extrusion mechanism 100 together form a Y-shaped structure. In each second extrusion mechanism 200, a feed bin 250 is arranged on a side of the storage bin 220 facing the first extrusion mechanism 100, and the shape of the feed bin 250 is adapted to the gap between the first extrusion mechanism 100, the storage bin 220, and the second motor 230.

[0066] As shown in the figure, the second barrel 210 of the second extrusion mechanism 200 on both sides, the storage bin 220 and the first barrel 110 of the first extrusion mechanism 100 in the middle are in a Y-shaped structure. In this case, on the one hand, the length dimension of the material extrusion device 10 can be reduced, thereby reducing the placement space of the material extrusion device 10. On the other hand, the material stored in the storage bin 220 moves downward under the action of gravity, so that the material in the storage bin 220 can be more easily squeezed into the second barrel 210 by the second screw 240. Moreover, since the material in the second barrel 210 can also move downward under the action of gravity, it is more convenient for the second screw 240 to extrude the material in the second barrel 210 into the first barrel 110.

[0067] Similarly, the feed bin 250 of each second extrusion mechanism 200 is arranged on the side of the storage bin 220 facing the first extrusion mechanism 100. On the premise that the feed bin 250 is connected with the storage bin 220, the feed bin 250 can be extended in the vertical direction, so that the effect of gravity can be fully utilized to quickly transfer the material input into the feed bin 250 to the storage bin 220 for storage.

[0068] By matching the shape of the feed bin 250 with the gap between the first extrusion mechanism 100 and the storage bin 220 and the second motor 230, the remaining space between the first extrusion mechanism 100 and the two second extrusion mechanisms 200 can be fully utilized to maximize the volume of the feed bin 250, which not only ensures the accuracy of material input but also allows more materials to be input into the feed bin 250 at one time, leaving more time for the operator to replenish materials.

[0069] Alternatively, if Figure 1 and Figure 2 As shown, in order to install and fix the two second extrusion mechanisms 200 on both sides of the first extrusion mechanism 100, a convex block 112 can be provided on the first barrel 110 to protrude outward, and by opening a threaded hole on the second barrel 210 and the convex block 112, and then threading the second barrel 210 and the convex block 112 through a threaded fastener, the second barrel 210 can be fixed on the convex block 112, so that the second extrusion mechanism 200 is installed and fixed on the side of the first extrusion mechanism 100. Further, a channel 1121 is opened on the convex block 112, which is connected to the first barrel 110 and the second barrel 210 respectively, that is, the material extruded by each second barrel 210 passes through its corresponding channel 1121 and enters the first barrel 110, so that the materials extruded by the two second extrusion mechanisms 200 enter the first barrel 110 through the corresponding channel 1121 and are mixed under the rotation of the first screw 130.

[0070] In order to ensure that the material extrusion device 10 can extrude the material normally, the present application further proposes an implementation method, please continue to refer to Figure 1 and Figure 2 As shown in the figure, the material extrusion device 10 also includes a first heating element 300 and at least two second heating elements 400. The first heating element 300 is arranged on the first barrel 110 for heating the mixed material in the first barrel 110, and the second heating element 400 is arranged on the second barrel 210 for heating the material in the second barrel 210.

[0071] In the embodiment of the present application, the input material is preferably a granular material, which is extruded into a filamentary material by the material extrusion device 10. In this case, in order to maintain the fluidity of the material and ensure that the material extrusion device 10 can extrude the filamentary material, a second heating element 400 is respectively provided on each second extrusion mechanism 200, and a first heating element 300 is provided on the first extrusion mechanism 100 to heat the material to facilitate melting and extrusion of the material.

[0072] Specifically, the second heating element 400 is disposed outside each second barrel 210, for example Figure 1 As shown, the second heating element 400 is arranged around the outside of the second barrel 210, so that the second heating element 400 can heat the second screw 240, and then the second screw 240 can heat the material in the second barrel 210 to melt, and extrude the molten material into the first barrel 110. The first heating element 300 is arranged outside the first barrel 110, for example Figure 1 The first heating element 300 is arranged after the connection between the first barrel 110 and each second barrel 210, and is arranged around the outside of the first barrel 110, so that the first heating element 300 can heat the first screw 130, and then the first screw 130 can heat the mixed material to melt.

[0073] By heating and keeping warm the material extruded by the second extrusion mechanism 200 through the second heating element 400, the fluidity of the material input into the first extrusion mechanism 100 can be ensured, so that the material extruded by the second extrusion mechanism 200 can be better mixed by the first screw 130, thereby improving the material mixing effect; by heating and keeping warm the material mixed by the second extrusion mechanism 200 through the first heating element 300, the mixed material can maintain a sufficient temperature and high fluidity before extrusion, so that the mixed material can be smoothly extruded through the nozzle 140, avoiding difficulties or uneven extrusion when extruding through the nozzle 140.

[0074] Preferably, in order to fix the material extrusion device 10 on the 3D printer body so as to move with the 3D printer body, as shown in FIG. Figure 1 and Figure 2As shown, a mounting member 150 is provided in the first extrusion mechanism 100 , and the material extrusion device 10 is fixed to the 3D printer body 20 through the mounting member 150 .

[0075] Among them, the material extrusion device is responsible for extruding the material according to a preset path and shape to construct a 3D model, and the movement of the material extrusion device is achieved through the movement of the 3D printer body.

[0076] Most 3D printers, especially FDM (fused deposition modeling) printers based on Cartesian coordinate systems, control the position of the print head (i.e., the material extrusion device 10) by precise movement of three main axes (X, Y, and Z axes). When a 3D printer receives a printing task, it first calculates the path and speed that the material extrusion device 10 needs to move based on the data of the 3D model. Then, the control system drives the 3D printer body to move along the X, Y, and Z axes to drive the material extrusion device 10 to a preset position. At the preset position, the material extrusion device 10 will start working and extrude the material through the nozzle 140. As the 3D printer body continues to move, the material extrusion device 10 will extrude the material layer by layer along the preset path and gradually build a 3D model.

[0077] In the embodiment of the present application, the first motor 120 is connected to the first barrel 110 through the mounting member 150, and the output shaft of the first motor 120 passes through the mounting member 150 and is connected to the first screw 130. Specifically, the first motor 120 is arranged at one end of the mounting member 150, and the other end is connected to the first barrel 110, so that the output shaft of the first motor 120 can pass through the mounting member 150 and be fixedly connected to the first screw 130. The first motor 120 can be as follows Figure 1 As shown, it is fixed on the mounting member 150 via the mounting flange 111. For details, please refer to the method of mounting and fixing the second motor 230 on the storage bin 220, which will not be repeated here.

[0078] By fixedly connecting the mounting member 150 to the 3D printer body, specifically, threaded holes can be opened on the mounting member 150 and the 3D printer body, and the mounting member 150 and the 3D printer are threadedly fixedly connected by threaded fasteners, so that the material extrusion device 10 can move with the 3D printer body to a preset position, and extrude the material through the nozzle 140 at the preset position for printing.

[0079] According to another aspect of the embodiments of the present application, a 3D printer is provided. The 3D printer includes a 3D printer body and a material extrusion device provided by any one of the above embodiments. The material extrusion device is fixedly connected to the 3D printer body.

[0080] In order to enable the material extrusion device to accurately extrude mixed materials of different proportions and enable the 3D printer to realize automatic printing with mixed materials of different material ratios, the present application also proposes a printing method, which is applied to the material extrusion device 10 provided in any of the above embodiments, and is used to mix and extrude the mixed materials according to a preset proportion for printing. The method is applied to the controller of the material extrusion device 10 or the main body of the 3D printer, and the controller controls the material extrusion device 10 based on the printing method. For details, please refer to Figure 5 , Figure 5 A flow chart of a printing method provided in an embodiment of the present application is shown. As shown in the figure, the printing method includes:

[0081] Step S100: Obtain the printing ratio.

[0082] Specifically, a printing ratio may be input into a controller of the material extrusion device, wherein the printing ratio is a ratio between different materials in the mixed material extruded by the first extrusion mechanism through the nozzle, for example, when the material extrusion device is provided with two second extrusion mechanisms, the ratio between material A and material B in the mixed material may be 2:8, and when the material extrusion device is provided with three second extrusion mechanisms, the ratio between material A, material B and material C in the mixed material may be 2:6:2.

[0083] Step S200: determining the speed ratio among the plurality of second motors according to the printing ratio.

[0084] Since the ratio of the material extruded by the first extrusion mechanism is determined by the material extrusion amount of each second extrusion mechanism, and the material extrusion amount of each second extrusion mechanism is determined by the speed of the corresponding second motor, after obtaining the printing ratio, the speed ratio between the multiple second motors can be determined according to the printing ratio, and then the actual speed corresponding to each second motor can be calculated by the speed ratio. Taking the material extrusion device as an example with two second extrusion mechanisms, when the ratio between material A and material B in the mixed material is 2:8, it can be determined that the speed ratio between the two second motors is 2:8, and then the actual speed of each second motor can be calculated according to the speed ratio. For example, it can be calculated that the speed of the first second motor is 600rpm, and the speed of the second second motor is 2400rpm.

[0085] Step S300: Control the plurality of second motors to operate at a speed ratio and drive the corresponding second screws to rotate, so that the first screw mixes the materials squeezed into the plurality of second screws according to the printing ratio and extrude them for printing.

[0086] After determining the actual speed of each second motor according to the speed ratio between the multiple second motors, each second motor can be controlled to run at its corresponding actual speed. For example, the first second motor is controlled to run at a speed of 600rpm, and the second second motor is controlled to run at a speed of 2400rpm, so that the first second motor drives its corresponding second screw to rotate at its corresponding speed of 600rpm, and the second second motor drives its corresponding second screw to rotate at a speed of 2400rpm, so that the two second motors control the two second screws to rotate at a speed ratio of 2:8, so that the two second screws squeeze the material stored in the storage bin into the second barrel according to the printing ratio of 2:8, and extrude the material in the second barrel into the first barrel according to the printing ratio of 2:8. After that, the first screw, driven by the first motor, mixes the material squeezed into each second screw, and extrude a mixed material with a material ratio of the printing ratio, such as 2:8, for printing the 3D model.

[0087] It should be noted that the speed of the first motor of the first extruder mechanism can be kept constant, which can be calculated based on the layer height of the model to be printed and the aperture of the nozzle, etc. For example, the first motor can always run at a speed of 2000 rpm.

[0088] In the embodiment of the present application, the speed ratio between the plurality of second motors is determined by the printing ratio, and then the plurality of second motors are controlled to run at the speed ratio, so that the plurality of second motors drive the corresponding plurality of second screws to rotate at the speed ratio, and the plurality of second screws are controlled to extrude the material into the first barrel according to the printing ratio, so that the first screw can mix and extrude the material extruded by the second screw according to the printing ratio. In the above manner, by setting the printing ratio, the material extrusion device can be accurately controlled to mix and extrude the mixed material for printing according to the actual required ratio, so as to realize the printing of 3D models using mixed materials of different ratios, and by setting a fixed printing ratio, the plurality of second motors can be controlled to run at a fixed speed ratio all the time, so that the first screw can mix and extrude the material extruded by the plurality of second screws all the time according to the printing ratio, ensuring the consistency and stability of the material mixing in the whole printing process, so that the 3D model can be automatically printed at a fixed material ratio all the time, and an efficient and reliable printing experience can be provided when printing 3D models with strict requirements on the material mixing ratio.

[0089] In some application scenarios, for example, when printing a multi-layered 3D model, assuming that the first to twentieth layers require a harder mixed material support, the material ratio needs to be set to 2:8, and from the twentieth to the 40th layer, in order to increase the flexibility and durability of the mixed material, the material ratio needs to be adjusted to 5:6.

[0090] Therefore, when printing a multi-layer model, in order to meet the requirements of different proportions of mixed materials in different layers to optimize the model structure or performance, it is necessary to control the material extrusion device to extrude different proportions of mixed materials in different layers for printing. According to some embodiments of the present application, optionally, refer to Figure 6 , Figure 6 A flow chart of a printing method provided in an embodiment of the present application is shown. As shown in the figure, the method includes the following steps:

[0091] Step S110: obtaining a printing ratio, wherein the printing ratio includes a first printing ratio and a second printing ratio, the first printing ratio corresponds to a first printing interval, and the second printing ratio corresponds to a second printing interval.

[0092] Taking the printing of a 10-layer 3D model as an example, the first printing ratio (e.g., the ratio between material A and material B) can be 2:8, and the corresponding first printing interval can be the first to fifth layers, and the second printing ratio (e.g., the ratio between material A and material B) can be 5:6, and the corresponding second printing interval can be the sixth to tenth layers. Taking the total printing length obtained by adding the printing length of each layer of a multi-layer 3D model as an example, assuming that the total printing length is 100 meters, the first printing ratio can be 1:9, and the corresponding first printing interval can be 0 to 50 meters, and the second printing ratio can be 7:3, and the corresponding second printing interval can be 51 to 100 meters.

[0093] Step S210: determining a rotation speed ratio between the plurality of second motors in the first printing interval according to the first printing ratio, and determining a rotation speed ratio between the plurality of second motors in the second printing interval according to the second printing ratio.

[0094] Taking the material extrusion device provided with two second extrusion mechanisms as an example, when the first printing ratio is 2:8 and the second printing ratio is 5:6, the speed ratio between the two second motors in the first printing interval can be determined to be 2:8 according to the first printing ratio (2:8), and then the actual speed corresponding to each second motor in the first printing interval can be calculated through the speed ratio (2:8), and the speed ratio between the two second motors in the second printing interval can be determined to be 5:6 according to the second printing ratio (5:6), so that the actual speed corresponding to each second motor in the second printing interval can be calculated through the speed ratio (5:6). For example, in the first printing interval, the speed of the first second motor is 600rpm, and the speed of the second second motor is 2400rpm; in the second printing interval, the speed of the first second motor is 1500rpm, and the speed of the second second motor is 1800rpm.

[0095] Step S310: In the first printing interval, control the multiple second motors to operate at a speed ratio corresponding to the first printing interval and drive the corresponding second screws to rotate, so that the first screw mixes the materials squeezed into the multiple second screws according to the first printing ratio and extrude them for printing.

[0096] Specifically, when printing the first printing interval, such as printing the first to fifth layers, the multiple second motors are controlled to run at a speed ratio corresponding to the first printing interval, for example, the first second motor is controlled to run at a speed of 600rpm, and the second second motor is controlled to run at a speed of 2400rpm, so that the first second motor drives its corresponding second screw to rotate at a speed of 600rpm, and the second second motor drives its corresponding second screw to rotate at a speed of 2400rpm, so that the two second motors control the two second screws to rotate at a speed ratio of 2:8, so that the two second screws squeeze the material stored in the storage bin into the second barrel according to the first printing ratio of 2:8, and extrude the material in the second barrel into the first barrel according to the first printing ratio of 2:8. After that, the first screw, driven by the first motor, mixes the material squeezed into each second screw, and extrude a mixed material with a material ratio of the first printing ratio, such as 2:8, to achieve printing of the first to fifth layers of the 3D model.

[0097] Step S320: Control the multiple second motors to operate at a speed ratio corresponding to the second printing interval and drive the corresponding second screws to rotate, so that the first screw mixes the materials squeezed into the multiple second screws according to the second printing ratio and extrude them for printing.

[0098] When printing the second printing interval, for example, when printing the sixth to tenth layers, the multiple second motors are controlled to run at a speed ratio corresponding to the second printing interval, for example, the first second motor is controlled to run at a speed of 1500rpm, and the second second motor is controlled to run at a speed of 1800rpm, so that the first second motor drives its corresponding second screw to rotate at a speed of 1500rpm, and the second second motor drives its corresponding second screw to rotate at a speed of 1800rpm, so that the two second motors control the two second screws to rotate at a speed ratio of 5:6, so that the two second screws squeeze the material stored in the storage bin into the second barrel according to the second printing ratio of 5:6, and extrude the material in the second barrel into the first barrel according to the second printing ratio of 5:6. After that, the first screw, driven by the first motor, mixes the material squeezed into each second screw, and extrude a mixed material with a material ratio of the second printing ratio, for example, 5:6, to realize printing of the sixth to tenth layers of the 3D model.

[0099] In an embodiment of the present application, by setting a first printing ratio corresponding to the first printing interval and a second printing ratio corresponding to the second printing interval, and determining the speed ratios between the multiple second motors in the first printing interval and the second printing interval respectively according to the first printing ratio and the second printing ratio, and then by controlling the multiple second motors to operate at the speed ratios corresponding to the first printing interval and the second printing interval when printing the first printing interval and the second printing interval respectively, it is possible to control the material extrusion device to extrude a mixed material with a material ratio of the first printing ratio for printing when printing the first printing interval, and to control the material extrusion device to extrude a mixed material with a material ratio of the second printing ratio for printing when printing the second printing interval, thereby achieving the purpose of extruding mixed materials of different ratios in different layers for printing, seamlessly meeting the material requirements of different layers, and realizing efficient and accurate automatic printing.

[0100] In some application scenarios, it may be necessary to gradually change the color, transparency or texture of the material between different layers to improve the visual effect of the 3D model, or it may be necessary to adjust the hardness, elasticity, conductivity, thermal conductivity and other physical properties of the material between different layers to print a 3D model with a specific functional gradient, such as printing a 3D model with a functional gradient from soft to hard to adapt to the different hardness and elasticity requirements of human tissues.

[0101] In order to print the 3D model with the above-mentioned gradient characteristics, it is necessary to control the material extrusion device to extrude mixed materials of different proportions when printing each layer or each section, and the material proportions between adjacent layers or adjacent sections change in the same manner. According to some embodiments of the present application, optionally, refer to Figure 7 , Figure 7 A flow chart of a printing method provided in an embodiment of the present application is shown. As shown in the figure, the method includes the following steps:

[0102] Step S120: obtaining the printing ratio and the total number of intervals, wherein the printing ratio includes a starting printing ratio and a final printing ratio, the starting printing ratio corresponds to the first printing interval, and the final printing ratio corresponds to the last printing interval.

[0103] Taking printing a 3D model with 101 layers as an example, the total number of intervals is 100, the starting printing ratio (for example, the ratio between material A and material B) can be 1:9, and the corresponding first printing interval is layer 1, and the final printing ratio (for example, the ratio between material A and material B) can be 8:2, and the corresponding last printing interval is layer 101.

[0104] In some embodiments, assuming that the total printing length of the multi-layer 3D model to be printed is 100 meters, the total printing length is divided into 20 parts, and the printing length of each part is 5 meters. The total number of intervals is 19, and the first printing interval corresponding to the starting printing ratio is the 1st part, that is, from 0 to 5 meters, and the last printing interval corresponding to the final printing ratio is the 20th part, that is, from 96 to 100 meters.

[0105] Step S220: determining the initial rotation speed ratio of each second motor according to the initial printing ratio, and determining the final rotation speed ratio of each second motor according to the final printing ratio.

[0106] For example, when the starting printing ratio is 1:9 and the final printing ratio is 8:2, the starting printing ratio of material A is 1 and the final printing ratio is 8, the starting printing ratio of material B is 9 and the final printing ratio is 2, that is, the starting speed ratio of the second motor of the second extrusion mechanism for input material A is 1 and the final speed ratio is 8, the starting speed ratio of the second motor of the second extrusion mechanism for input material B is 9 and the final speed ratio is 2.

[0107] Step S230: determining the change in the rotation speed ratio between two adjacent printing intervals of each second motor according to the starting rotation speed ratio, the final rotation speed ratio and the total number of interval intervals.

[0108] After determining the starting speed ratio and final speed ratio of each second motor, for example, when the starting speed ratio of the first second motor is determined to be 1 and the final speed ratio is determined to be 8, the speed ratio change of two adjacent printing intervals of the first second motor can be calculated through the starting speed ratio, final speed ratio and the total number of intervals of the first second motor. Specifically, it can be calculated according to the following formula: Speed ​​ratio change = (final speed ratio - starting speed ratio) / total number of intervals.

[0109] For example, when the total number of intervals is 100, the starting printing ratio is 1:9, and the final printing ratio is 8:2, the change in the speed ratio of the first and second motors is △ r1 is: △ r1=(8-1) / 100=0.07, the change in the speed of the second motor △ r2 is: △ r2=(2-9) / 100=-0.07.

[0110] Step S240: determining the corresponding speed ratio between the plurality of second motors in each printing interval according to the starting speed ratio and the speed ratio change.

[0111] Specifically, the speed ratio of the second motor corresponding to material A in each printing interval = the starting speed ratio + the previous printing interval of the current printing interval × the change in speed ratio. It can be calculated according to the following formula:

[0112] The speed ratio of the i-th printing interval = the starting speed ratio + the (i-1)-th printing interval × the change in speed ratio.

[0113] For example, when the initial speed ratio of the first second motor is 1 and the speed ratio change is 0.07, the speed ratio r5 of the first second motor in the fifth printing interval is: r5=1+(5-1)×0.07=1.28. When the initial speed ratio of the second second motor is 9 and the speed ratio change of the second second motor is -0.07, the speed ratio r5 of the second second motor in the fifth printing interval is: r5=9+(5-1)×(-0.07)=8.28.

[0114] After determining the rotation speed proportion of each second motor in each printing interval, the rotation speed ratio corresponding to the plurality of second motors in each printing interval can be determined, and further the actual rotation speed corresponding to each second motor in each printing interval can be calculated.

[0115] For example, after determining that the rotation speed ratio of the first second motor in the fifth printing interval is 1.28 and the rotation speed ratio of the second second motor in the fifth printing interval is 8.72, it can be determined that the rotation speed ratio between the two second motors in the fifth printing interval is 1.28:8.72, and then, according to the rotation speed ratio of 1.28:8.72, the actual rotation speed of each second motor in the fifth printing interval can be calculated. For example, the rotation speed of the first second motor in the fifth printing interval is 256rpm, and the rotation speed of the other second motor in the fifth printing interval is 1744rpm.

[0116] Step S330: In each printing interval, control the multiple second motors to run at a speed ratio corresponding to the printing interval and drive the corresponding second screws to rotate, so that the first screw mixes the materials squeezed into the multiple second screws according to the printing ratio corresponding to the printing interval and extrude them for printing.

[0117] Specifically, when printing each printing interval, for example, when printing the 5th printing interval, the multiple second motors are controlled to run at a speed ratio corresponding to the 5th printing interval. For example, the first second motor is controlled to run at a speed of 256rpm, and the second second motor is controlled to run at a speed of 1744rpm, so that the first second motor drives its corresponding second screw to rotate at a speed of 256rpm, and the second second motor drives its corresponding second screw to rotate at a speed of 1744rpm, so that the two second motors control the two second screws to rotate at a speed ratio of 1.28:8.72.

[0118] Since the speed ratios of the second motors in each printing interval correspond to the printing ratios of each printing interval, for example, when the speed ratios of the two second motors in the fifth printing interval are 1.28:8.72, the printing ratios of the fifth printing interval are also 1.28:8.72. Therefore, when the two second screws rotate at a speed ratio of 1.28:8.72 in the fifth printing interval, the two second screws squeeze the material stored in the storage bin into the second barrel at the printing ratio of 1.28:8.72 corresponding to the fifth printing interval, and squeeze the material in the second barrel into the first barrel at the printing ratio of 1.28:8.72. After that, the first screw, driven by the first motor, mixes the material squeezed into each second screw, and extrude the mixed material with a material ratio of 1.28:8.72 to print the fifth printing interval of the 3D model.

[0119] Through the above method, the first screw can mix and extrude the materials squeezed into the multiple second screws starting from the starting printing ratio, and gradually change the printing ratio change amount to the final printing ratio in a manner of evenly changing the printing ratio change, thereby realizing a gradual material ratio change between the first printing interval and the last printing interval, ensuring the accuracy and consistency of the material ratio change in each printing interval, and printing a 3D model with gradient characteristics to meet the user's visual effects or gradient function requirements.

[0120] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A material extrusion device, applied to a 3D printer, characterized in that: The 3D printing device comprises: a first extrusion mechanism and at least two second extrusion mechanisms; The first extrusion mechanism includes a first barrel, a first motor and a first screw, wherein the first motor is disposed at one end of the first barrel and a nozzle is disposed at the other end, the first screw is disposed in the first barrel, and one end of the first screw is connected to the first motor; Each of the second extrusion mechanisms comprises a second barrel, a material storage bin, a second motor, a second screw and a feed bin. In each of the second extrusion mechanisms, two ends of the second barrel are respectively connected to the first barrel and one end of the material storage bin, the other end of the material storage bin is provided with the second motor, and the material storage bin is also connected to the feed bin, the second screw is provided in the second barrel, and one end of the second screw passes through the material storage bin and is connected to the second motor; In each of the second extrusion mechanisms, the storage bin is used to store the material input from the feed bin, and the second motor is used to drive the second screw to rotate so as to squeeze the material stored in the storage bin into the second barrel, and to extrude the material in the second barrel into the first barrel; The first screw is used to mix the materials extruded into the first barrel from different extrusion mechanisms and then extrude them through the nozzle.

2. The material extrusion device according to claim 1, characterized in that: In each of the second extrusion mechanisms, a dimension of the storage bin along the radial direction of the second screw is greater than a dimension of the second barrel along the radial direction of the second screw.

3. The material extrusion device according to claim 1, characterized in that: In each of the second extrusion mechanisms, a funnel structure is provided at a position in the second barrel connected to the material storage bin, and a material guide notch is opened on the wall at the lower opening of the funnel structure, and the slope of the material guide notch is greater than the slope of the funnel structure.

4. The material extrusion device according to claim 1, characterized in that: Each feed bin is used to input different materials, and each second screw is used to rotate at a different speed under the drive of the corresponding second motor, so as to extrude the material stored in the corresponding storage bin into the corresponding second barrel at different rates, and extrude the material in the corresponding second barrel into the first barrel at different rates, so that the first screw can mix and extrude the materials squeezed into different second barrels in the first barrel in a predetermined proportion.

5. The material extrusion device according to claim 1, characterized in that: The two second extrusion mechanisms are symmetrically arranged on both sides of the first extrusion mechanism, and the two second extrusion mechanisms and the first extrusion mechanism together form a Y-shaped structure; In each of the second extrusion mechanisms, the feed bin is arranged on a side of the storage bin facing the first extrusion mechanism, and the shape of the feed bin is adapted to the gap between the first extrusion mechanism, the storage bin and the second motor.

6. The material extrusion device according to claim 5, characterized in that: In each of the second extrusion mechanisms, the volume of the feed bin is greater than the volume of the storage bin.

7. A 3D printer, characterized in that: The 3D printer comprises: a 3D printer body and a material extrusion device according to any one of claims 1 to 6, wherein the material extrusion device is fixedly connected to the 3D printer body.

8. A printing method, applied to the material extrusion device according to any one of claims 1 to 6, characterized in that: The printing method comprises: Get the printing scale; determining a speed ratio among the plurality of second motors according to the printing ratio; The plurality of second motors are controlled to operate at the speed ratio and drive the corresponding second screws to rotate, so that the first screw mixes the materials squeezed into the plurality of second screws according to the printing ratio and extrude them for printing.

9. The printing method according to claim 8, characterized in that: The printing ratio includes a first printing ratio and a second printing ratio, the first printing ratio corresponds to a first printing interval, and the second printing ratio corresponds to a second printing interval; determining a speed ratio among the plurality of second motors according to the printing ratio; Controlling the plurality of second motors to operate at the speed ratio and drive the corresponding second screws to rotate further includes: Determine a speed ratio between the plurality of second motors in the first printing interval according to the first printing ratio, and determine a speed ratio between the plurality of second motors in the second printing interval according to the second printing ratio; In the first printing interval, the plurality of second motors are controlled to operate at a speed ratio corresponding to the first printing interval and drive the corresponding second screws to rotate, so that the first screw mixes the materials squeezed into the plurality of second screws according to the first printing ratio and extrude them for printing; In the second printing interval, the multiple second motors are controlled to operate at a speed ratio corresponding to the second printing interval and drive the corresponding second screws to rotate, so that the first screw mixes the materials squeezed into the multiple second screws according to the second printing ratio and extrude them for printing.

10. The printing method according to claim 8, characterized in that: The method of obtaining a printing ratio; determining a speed ratio between a plurality of second motors according to the printing ratio; and controlling the plurality of second motors to operate at the speed ratio and drive the corresponding second screws to rotate further includes: Obtaining the printing ratio and the total number of intervals, wherein the printing ratio includes a starting printing ratio and a final printing ratio, the starting printing ratio corresponds to the first printing interval, and the final printing ratio corresponds to the last printing interval; Determine the starting speed ratio of each second motor according to the starting printing ratio, and determine the final speed ratio of each second motor according to the final printing ratio; Determine the change in the rotation speed ratio between two adjacent printing intervals of each second motor according to the starting rotation speed ratio, the final rotation speed ratio and the total number of interval intervals; Determine a speed ratio corresponding to each printing interval between the plurality of second motors according to the starting speed ratio and the speed ratio change; In each printing interval, the multiple second motors are controlled to run at a speed ratio corresponding to the printing interval and drive the corresponding second screws to rotate, so that the first screw mixes the materials squeezed into the multiple second screws according to the printing ratio corresponding to the printing interval and extrude them for printing.

Images