Material extrusion device and 3D printer

Abstract

The embodiment of the utility model 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] Embodiments of the present application relate to the technical field of 3D printing, in particular to a material extruding device and a 3D printer. BACKGROUND

[0002] A 3D printer is an additive manufacturing equipment for rapid prototyping, which is a technology for constructing objects through layer-by-layer printing based on a digital model file, using granular or filamentous plastic and other adhesive materials. Common technologies include Fused Deposition Modeling (FDM), Selective Laser Sintering (SLS), and Stereo Lithography Appearance (SLA). At present, the extruder head of a 3D printer using the FDM technology can only melt and extrude one kind of material, and cannot realize the multi-material fusion extrusion of the same product, resulting in that the 3D printer can only use a single material to print products. CONTENT OF THE UTILITY MODEL

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

[0004] According to an aspect of an embodiment of the present application, a material extruding device applied to a 3D printer is provided, which comprises: a first extruding mechanism and at least two second extruding mechanisms; the first extruding mechanism comprises a first barrel, a first motor and a first screw rod, one end of the first barrel is provided with the first motor, the other end is provided with a nozzle, the first screw rod is arranged in the first barrel, and one end of the first screw rod is connected with the first motor; each second extruding mechanism comprises a second barrel, a storage bin, a second motor, a second screw rod and a feeding bin, in each second extruding mechanism, two ends of the second barrel are respectively communicated with the first barrel and one end of the storage bin, the other end of the storage bin is provided with the second motor, the storage bin is further communicated with the feeding bin, the second screw rod is arranged in the second barrel, and one end of the second screw rod passes through the storage bin and is connected with the second motor; in each second extruding mechanism, the storage bin is used for storing the material input from the feeding bin, the second motor is used for driving the second screw rod to rotate to extrude the material stored in the storage bin into the second barrel, and extrude the material in the second barrel to the first barrel, and the first screw rod is used for mixing the materials extruded into the first barrel from different extruding mechanisms and then extruding the mixed materials through the nozzle.

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

[0006] In an alternative, in each second extruding mechanism, a funnel structure is arranged at a position of the second barrel communicating with the storage bin, and a guide gap is arranged on the wall of the lower opening of the funnel structure, and the slope of the guide gap is greater than the slope of the funnel structure.

[0007] In an alternative, each feeding bin is used for inputting different materials, and each second screw is used for rotating at different speeds under the driving of the corresponding second motor, so as to extrude the materials stored in the corresponding storage bin into the corresponding second barrel at different rates, and extrude the materials in the corresponding second barrel into the first barrel at different rates, so that the first screw mixes and extrudes the materials extruded from the different second barrels in the first barrel at a predetermined ratio.

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

[0009] In an alternative, in each second extruding mechanism, the volume of the feeding bin is greater than the volume of the storage bin.

[0010] In an alternative, the first extruding mechanism further comprises a mounting member, the first motor is connected to the first barrel through the mounting member, and the output shaft of the first motor is connected to the first screw through the mounting member; the mounting member is further used for connecting with the 3D printer body, so as to fix the material extruding device on the 3D printer body.

[0011] In an alternative, the material extruding device further comprises a first heating member and at least two second heating members, the first heating member is arranged on the first barrel and used for heating the mixed materials in the first barrel, and the second heating members are arranged on the second barrels and used for heating the materials in the second barrels.

[0012] In an alternative, the first barrel is outwardly protrudingly provided with a protruding block, the second barrel is connected to the protruding block, and a channel is arranged on the protruding block and communicating with the first barrel and the second barrel respectively, and the channel is used for allowing the materials extruded from the second barrel to enter the first barrel.

[0013] According to still another aspect of the embodiments of the present application, a 3D printer is provided, which comprises a 3D printer body and the material extruding device provided by any one of the embodiments described above, and the material extruding device is fixedly connected to the 3D printer body.

[0014] The material extrusion device provided by the embodiment of the present application, in each second extrusion mechanism, the storage bin is arranged, and the storage bin is communicated with the feeding bin, so that the storage bin can store the material input from the feeding bin; the two ends of the second barrel are communicated with one end of the storage bin and the first barrel respectively, and the second motor connected with the other end of the storage bin is connected with the second screw, so that the second screw can rotate in the second barrel under the driving of the second motor, and the material stored in the storage bin is extruded into the second barrel, and then extruded into the first barrel; the first motor arranged at one end of the first barrel is connected with one end of the first screw, so that the first screw can rotate in the first barrel under the driving of the first motor, the material extruded by each second extrusion mechanism is mixed, and the nozzle arranged at the other end of the first barrel is extruded for printing. In the above manner, different materials are input into the feeding bin of each second extrusion mechanism respectively, so that the first screw can mix and extrude at least two materials extruded by the first extrusion mechanism, the multi-material mixing printing function of the same product of the 3D printer is realized, and by arranging the storage bin to store the material input from the feeding bin, the material can be 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 continuously extrude the material for printing, and the printing quality of the 3D model is ensured.

[0015] The above description is only a summary of the technical scheme of the present application, in order to more clearly understand the technical means of the present application, and can be implemented according to the content of the specification, and in order to make the above and other purposes, characteristics and advantages of the present application more obvious and easy to understand, the following specific embodiments of the present application are described. BRIEF DESCRIPTION OF DRAWINGS

[0016] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included to provide a description of the preferred embodiments and are not meant to limit the present application. Moreover, the same reference numerals in the attached drawings refer to the same or similar components. In the drawings:

[0017] Figure 1 The structure schematic view of the material extrusion device provided by the embodiment of the present application is shown in the figure;

[0018] Figure 2 The sectional view of the material extrusion device provided by the embodiment of the present application is shown in the figure;

[0019] Figure 3 The structure schematic view of the material extrusion device provided by the embodiment of the present application is shown in the figure;

[0020] Figure 4 The top view structure diagram of the second barrel provided by the embodiment of the present application is shown in the figure;

[0021] Figure 5A flowchart of a printing method provided by an embodiment of the present application is shown in FIG. 1.

[0022] Figure 6 A flowchart of a printing method provided by an embodiment of the present application is shown in FIG. 1.

[0023] Figure 7 A flowchart of a printing method provided by an embodiment of the present application is shown in FIG. 1.

[0024] The reference signs in the detailed description of the embodiments are as follows:

[0025] 10, material extrusion device

[0026] 100, first extrusion mechanism; 110, first barrel; 111, mounting flange; 112, protrusion; 1121, channel; 120, first motor; 121, shaft coupling; 130, first screw; 140, nozzle; 150, mounting member; 200, second extrusion mechanism; 210, second barrel; 211, hopper structure; 2111, material guiding gap; 220, storage bin; 230, second motor; 240, second screw; 250, feeding bin; 300, first heating member; 400, second heating member. DETAILED DESCRIPTION

[0027] The embodiments of the technical solutions of the present application will be described in detail below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present application, and therefore only serve as examples, and cannot limit the protection scope of the present application.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments of the present application, and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above description of drawings are intended to cover non-exclusive inclusion.

[0029] 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 "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0030] Reference to“an embodiment” herein means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase“in an embodiment” in various places in the specification are not necessarily referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. As will be apparent to those of ordinary skill in the art, embodiments described herein can be combined with other embodiments.

[0031] In the description of the embodiments of the application, the term“and / or” is merely an association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of existence of A, existence of A and B, and existence of B. In addition, the character“ / ” herein generally represents an“or” relationship between the front and rear associated objects.

[0032] In the description of the embodiments of the application, the term“a plurality of” refers to two or more (including two), and similarly, “a plurality of groups” refers to two or more groups (including two groups), and “a plurality of pieces” refers to two or more pieces (including two pieces).

[0033] In the description of the embodiments of the application, the technical terms“center”,“longitudinal”,“transverse”,“length”,“width”,“thickness”,“upper”,“lower”,“front”,“rear”,“left”,“right”,“vertical”,“horizontal”,“top”,“bottom”,“inner”,“outer”,“clockwise”,“counterclockwise”,“axial”,“radial”,“circumferential” and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the embodiments of the application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the embodiments of the application.

[0034] In the description of the embodiments of the application, unless otherwise explicitly specified and limited, the technical terms“mounting”,“connection”,“connection”,“fixing” and the like should be understood broadly, for example, can be fixedly connected, or can be detachably connected, or can be integrated; can be mechanically connected, or can be electrically connected; can be directly connected, or can be indirectly connected through an intermediate medium; can be the internal communication 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 application can be understood according to the specific circumstances.

[0035] 3D printer is a kind of rapid prototyping additive manufacturing equipment, which is a kind of technology that uses granular or filamentous plastic and other adhesive materials to construct objects through layer-by-layer printing based on digital model files. At present, the extruder head of the fused deposition modeling 3D printer is mainly designed for single-bin feeding and single-screw extrusion, which can only melt and extrude one kind of material, resulting in that the 3D printer can only use a single material to print products and cannot realize multi-material fusion printing of the same product.

[0036] To solve the above problems, at least two feeding bins can be provided to feed the material extrusion device, and then at least two feeding screws are provided to supply material to an extrusion screw, so that the extrusion screw can mix and extrude the materials fed by the at least two feeding screws. The material extrusion device can realize the mixing and extrusion of at least two materials, so that the 3D printer can realize multi-material mixing printing of the same product.

[0037] In the above scheme, in order to improve the feeding efficiency, the feeding bin is usually communicated with the barrel with the built-in feeding screw to directly feed the feeding screw through the feeding bin. However, in actual operation, if the manual feeding method is used to input material into the feeding bin, the situation that the material is not input into the feeding bin in time is easy to occur, which causes the material extrusion device to be unable to continuously extrude material for printing. On the other hand, when an automatic feeding system is used to input material into the feeding bin, once the feeding machine encounters a temporary fault, the risk of temporary interruption of material supply is also faced. This untimely material supply also interferes with the stability of the material extrusion device to extrude material, resulting in a decrease in the quality of the 3D model printed by the 3D printer.

[0038] Therefore, the material extrusion device provided by the present application is provided, which stores the material input through the feeding bin in the storage bin communicated with the barrel with the built-in feeding screw, and the storage bin is communicated with the feeding bin. In this way, 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 screw to the extrusion screw, so that the material extrusion device can continuously extrude material for printing, ensuring the printing quality of the 3D model.

[0039] Please refer to Figure 1 and Figure 2 , Figure 1 Fig. 1 shows a structural schematic diagram of the material extrusion device provided by the embodiment of the present application, Figure 2A cross-sectional view of a material extrusion apparatus provided in an embodiment of this application is shown. This material extrusion apparatus is used in a 3D printer as a material extrusion head to achieve the printing of 3D models. As shown, the material extrusion apparatus 10 includes a first extrusion mechanism 100 and at least two second extrusion mechanisms 200.

[0040] The first extrusion mechanism 100 includes a first barrel 110, a first motor 120 and a first screw 130. The first motor 120 is provided at one end of the first barrel 110 and the nozzle 140 is provided at the other end. The first screw 130 is disposed inside the first barrel 110 and one end of the first screw 130 is connected to the first motor 120.

[0041] 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 the second motor 230, and the storage bin 220 is also connected to the feed bin 250. The second screw 240 is disposed inside 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.

[0042] In each second extrusion mechanism 200, a storage bin 220 is used to store material input from the feed bin 250. A second motor 230 is used to drive a second screw 240 to rotate, so as to extrude the material stored in the storage bin 220 into a second barrel 210, and extrude the material in the second barrel 210 into a first barrel 110. A first screw 130 is used to mix the materials extruded from different extrusion mechanisms into the first barrel 110 and then extrude them through a nozzle 140.

[0043] Specifically, a mounting flange can be provided at one end of the first material cylinder 110, and the first motor 120 can be fixedly mounted at one end of the first material cylinder 110 through the mounting flange.

[0044] 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 provided inside the first barrel 110, and as shown... Figure 3 As shown, the output shaft of the first motor 120 is fixedly connected to one end of the first screw 130 via 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 via the coupling 121, so as to convey the material in the first barrel 110 to the nozzle 140 and extrude it through the nozzle 140.

[0045] The number of second extrusion mechanisms 200 can be set to 2, 3, 4 or even more than 4, and each second extrusion mechanism 200 is located on the side of the first extrusion mechanism 100. The figure only illustrates the example of setting 2 second extrusion mechanisms 200, and does not constitute a limitation.

[0046] In this embodiment, one side of the storage bin 220 can be threadedly connected to the feed bin 250, connecting the storage bin 220 and the feed bin 250, so that the storage bin 220 can receive and store materials input from the feed bin 250. One end of the storage bin 220 is connected to one end of the second material cylinder 210, and one end of the second material cylinder 210 is connected to the first material cylinder 110, so that the storage bin 220 can temporarily store materials input from the feed bin 250, and the materials stored in the storage bin 220 can be supplied to the second material cylinder 210, thereby allowing the materials in the second material cylinder 210 to be transferred to the first material cylinder 110.

[0047] Specifically, in order to supply the material stored in the storage silo 220 to the second feed cylinder 210, a second screw 240 is installed in the second feed cylinder 210, and as follows: Figure 3 As shown, the output shaft of the second motor 230 is fixedly connected to one end of the second screw 240 via a 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 via the coupling 121. The threaded groove on the second screw 240 extends into the storage bin 220, allowing the second screw 240 to transfer material from the storage bin 220 to the second barrel 210 during rotation, and to extrude material from the second barrel 210 into the first barrel 110.

[0048] Specifically, the second motor 230 can be as follows: Figure 1 As shown, the material is fixedly mounted on one end of the storage silo 220 via the mounting flange 111. For example, threaded holes can be made on both the second motor 230 and the mounting flange 111, and the second motor 230 can be threadedly connected to the mounting flange 111 via threaded fasteners. In addition, by making threaded holes on both the storage silo 220 and the mounting flange 111, and then threadedly connecting the storage silo 220 to the mounting flange 111 via threaded fasteners, the second motor 230 is installed and fixed on the storage silo 220.

[0049] The storage bin 220 is a hollow structure, which has enough space to store the material input from the feeding bin 250. Even if the material input to the feeding bin 250 is stopped for a short time, the material stored in the storage bin 220 can continue to be extruded into the second barrel 210 by the second screw 240, ensuring that the second extrusion mechanism 200 can continuously extrude the material into the first extrusion mechanism 100 for a short time without material input, so that the first extrusion mechanism 100 can continuously extrude the mixed material through the nozzle 140 for printing, ensuring the normal operation of the printing work.

[0050] In the embodiments of the present application, the material input to each feeding bin 250 can be the same or different. For example, material A can be input to the feeding bin 250 of both second extrusion mechanisms 200, and when the second screw 240 of both second extrusion mechanisms 200 extrudes the material A from the second barrel 210 into the first barrel 110, the first screw 130 mixes the material A extruded by the two second extrusion mechanisms 200 and delivers the material A to the nozzle 140 for extruding the material A; or material A can be input to the feeding bin 250 of one first extrusion mechanism 100, and material B can be input to the feeding bin 250 of the other first extrusion mechanism 100, and when the second screw 240 of one second extrusion mechanism 200 extrudes the 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 extrudes the material B from the corresponding second barrel 210 into the first barrel 110, the first screw 130 mixes the material A and the material B in the first barrel 110 and delivers the mixed material to the nozzle 140 for extruding the mixed material.

[0051] In some embodiments, the size of the storage bin 220 of each second extrusion mechanism 200 along the radial direction of the second screw 240 can be greater than the size of the second barrel 210 along the radial direction of the second screw 240, in which case the material input from the feeding bin 250 to the storage bin 220 can cover the communication between the storage bin 220 and the second barrel 210, and be extruded into the second barrel 210 by the second screw 240 in time, to ensure the continuity of the extrusion of the material into the second barrel 210 by the second screw 240, thereby ensuring the continuity of the supply of the second extrusion mechanism 200 to the first extrusion mechanism 100.

[0052] In some embodiments, the volume of the feeding bin 250 can be greater than the volume of the storage bin 220, which not only allows more material to be input to the feeding bin 250 at one time, but also allows the feeding bin 250 to temporarily store more material when the storage bin 220 has enough material, without the need for continuous input of material, so that the operator has enough time to replenish the material while ensuring that the mixed material extruded by the material extrusion device 10 is uninterrupted and used for printing.

[0053] The material extrusion device 10 provided by the embodiment of the present application, in each second extrusion mechanism 200, the storage bin 220 is arranged, and the storage bin 220 is communicated with the feeding bin 250, so that the storage bin 220 can store the material input from the feeding bin 250; the two ends of the second barrel 210 are communicated with one end of the storage bin 220 and the first barrel 110 respectively, and the second motor 230 connected with the other end of the storage bin 220 is connected with the second screw 240, so that the second screw 240 can rotate in the second barrel 210 under the driving of the second motor 230, and the material stored in the storage bin 220 is extruded into the second barrel 210, and then extruded into the first barrel 110; the first motor 120 arranged at one end of the first barrel 110 is connected with one end of the first screw 130, so that the first screw 130 can rotate in the first barrel 110 under the driving of the first motor 120, the material extruded by each second extrusion mechanism 200 is mixed, and is extruded through the nozzle 140 arranged at the other end of the first barrel 110 for printing. In the above manner, different materials are input into the feeding bin 250 of each second extrusion mechanism 200 respectively, so that the first screw 130 can mix and extrude at least two materials extruded by the first extrusion mechanism 100, realize the multi-material mixing printing function of the same product of the 3D printer, and the storage bin 220 is arranged to store the material input from the feeding bin 250, so that the material can still be 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 continuously extrude the material for printing, and the printing quality of the 3D model is ensured.

[0054] In order to make the material stored in the storage bin 220 more easily extruded into the second barrel 210, the present application further provides an embodiment, please continue to refer to Figure 2 , and combine Figure 4 , Figure 4 The top view structure diagram of the second barrel provided by the embodiment of the present application is shown, as shown in the figure, in each second extrusion mechanism 200, the position communicated with the storage bin 220 in the second barrel 210 is provided with a funnel structure 211, the wall at the lower opening of the funnel structure 211 is provided with a material guiding gap 2111, and the slope at the material guiding gap 2111 is greater than the slope of the funnel structure 211.

[0055] By arranging the funnel structure 211, the material input from the feeding bin 250 can converge at the lower opening of the funnel structure 211, that is, around the second screw 240, under the flow guiding action of the funnel structure 211, so as to facilitate the material stored in the storage bin 220 to be extruded into the second barrel 210 under the rotation of the second screw 240, thereby avoiding the accumulation of the material in the inner cavity of the storage bin 220.

[0056] Wherein, a material guiding notch 2111 can be arranged on the wall at the lower opening, or two material guiding notches 2111 can be symmetrically arranged on the wall at the lower opening as shown. Figure 4 By arranging the material guiding notches 2111 with greater slope on the wall at the lower opening of the funnel structure 211, the material in the material storage bin 220 can be more quickly guided to the second screw 240, and the second screw 240 can more easily extrude the material at the funnel structure 211 into the second barrel 210, so that the material does not accumulate at the lower opening of the funnel structure 211, and the flow of the material to the second screw 240 is more rapid.

[0057] When the material extruded by the material extruding device 10 is used to print a model, different proportions of materials can be mixed to improve the hardness and toughness of the model, so that the performance of the model can be optimized, or a certain proportion of low-cost materials can be mixed to reduce the cost while ensuring the performance of the model.

[0058] Based on the above, in order to enable the material extruding device 10 to extrude mixed materials with different proportions, the present application further provides an embodiment, please continue to refer to Figure 1 and Figure 2 As shown in the figure, each feeding bin 250 is used to input different materials, and each second screw 240 is used to rotate at different speeds under the driving of the corresponding second motor 230, so as to extrude the material stored in the corresponding material 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, and then the first screw 130 mixes and extrudes the materials extruded from different second barrels 210 in the first barrel 110 at a predetermined proportion.

[0059] Since the second motors 230 of the two second extruding mechanisms 200 are controlled to operate at different speeds, the corresponding second screws 240 can be controlled to rotate at different speeds and extrude the material into the first barrel 110 at different rates, so that the first screw 130 can mix and extrude materials with different proportions. Therefore, by controlling the second motor 230 to operate at a predetermined proportion of speed, the material extrusion amount of the second extruding mechanism 200 can be controlled, and then the first extruding mechanism 100 can be controlled to extrude mixed materials with a predetermined proportion.

[0060] 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 operate at speed a and the other second motor 230 is controlled to operate at speed b, then the two second screws 240 rotate at speed a and speed b respectively, and then the second screw 240 rotating at speed a extrudes the material A stored in the storage bin 220 into the corresponding second barrel 210 at rate a and extrudes the material A in the second barrel 210 out of the first barrel 110 at rate a, and the second screw 240 rotating at speed a extrudes the material B stored in the storage bin 220 into the corresponding second barrel 210 at rate b and extrudes the material B in the second barrel 210 out of the first barrel 110 at rate b, so that the first screw 130 mixes the material A and the material B in the first barrel 110 at a ratio of a:b and delivers the mixed material to the nozzle 140 for extrusion.

[0061] By controlling the types of materials input into the different second extrusion mechanisms 200 and by controlling the second motors 230 of each second extrusion mechanism 200 to operate at different speeds respectively, the material extrusion device 10 can be controlled to realize the mixing and extrusion of different materials and different proportions, so that the dynamic adjustment of the mixing of different proportions of materials can be realized by controlling the speed of the motor during the printing process, so as to extrude mixed materials of 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.

[0062] In order to maximize the volume of the feed bin 250 while reducing the volume of the material extrusion device 10, the present application further proposes an embodiment, please continue to refer to Figure 1 As shown in the figure, the two second extrusion mechanisms 200 are symmetrically arranged on the two 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, the feed bin 250 is arranged on the 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 and the storage bin 220 and the second motor 230.

[0063] As shown in the figure, the second barrel 210 and the storage bin 220 of the second extrusion mechanism 200 on both sides are in Y-shaped structure with the first barrel 110 of the first extrusion mechanism 100 in the middle. In this case, on the one hand, the length 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 can move downward under the action of gravity, so that the material in the storage bin 220 can be more easily extruded into the second barrel 210 by the second screw 240. 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.

[0064] Similarly, the feeding bin 250 of each second extrusion mechanism 200 is arranged on the side of the storage bin 220 facing the first extrusion mechanism 100. The feeding bin 250 can be arranged in the vertical direction under the premise of ensuring that the feeding bin 250 is in communication with the storage bin 220, so that the material input into the feeding bin 250 can be quickly transmitted to the storage bin 220 for storage under the action of gravity.

[0065] The shape of the feeding bin 250 is adapted to the gap between the first extrusion mechanism 100 and the storage bin 220 and the second motor 230. The remaining space of the first extrusion mechanism 100 and the two second extrusion mechanisms 200 can be fully utilized to maximize the volume of the feeding bin 250. This not only ensures the accuracy of material input, but also allows more material to be input into the feeding bin 250 at one time, leaving more time for the operator to supplement the material.

[0066] Optionally, as shown in Figure 1 and Figure 2 In order to install and fix the two second extrusion mechanisms 200 on both sides of the first extrusion mechanism 100, the protruding block 112 can be arranged on the outside of the first barrel 110. The threaded holes are formed on the second barrel 210 and the protruding block 112, and then the second barrel 210 and the protruding block 112 are threadedly connected by the threaded fasteners. In this way, the second barrel 210 can be fixed on the protruding block 112, and the second extrusion mechanism 200 can be installed and fixed on the side of the first extrusion mechanism 100. Further, the channel 1121 is formed on the protruding block 112 and is in communication with the first barrel 110 and the second barrel 210, respectively. That is, the material extruded by each second barrel 210 passes through the 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 channels 1121 and are mixed under the rotation of the first screw 130.

[0067] In order to ensure that the material extrusion device 10 can normally extrude the material, the present application further provides an embodiment, which will be described belowFigure 1 and Figure 2 As shown in the figure, the material extruding device 10 further comprises a first heating member 300 and at least two second heating members 400, the first heating member 300 is arranged on the first barrel 110 for heating the mixed material in the first barrel 110, and the second heating member 400 is arranged on the second barrel 210 for heating the material in the second barrel 210.

[0068] In the embodiment of the present application, the input material is preferably granular material, which is extruded into a filament material by the material extruding device 10. In this case, in order to maintain the flowability of the material and ensure that the material extruding device 10 can extrude the filament material, the second heating member 400 is arranged on each second extruding mechanism 200 respectively, and the first heating member 300 is arranged on the first extruding mechanism 100 to heat the material, so as to facilitate the melting and extrusion of the material.

[0069] Specifically, the second heating member 400 is arranged outside each second barrel 210, for example, as shown in the figure, it is arranged around the outside of the second barrel 210, so that the second heating member 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 melted material into the first barrel 110. Figure 1 The first heating member 300 is arranged outside the first barrel 110, for example, as shown in the figure, it is arranged at a position after the first barrel 110 communicates with each second barrel 210, and is arranged around the outside of the first barrel 110, so that the first heating member 300 can heat the first screw 130, and then the first screw 130 can heat the mixed material to melt. Figure 1

[0070] By heating and keeping warm the material extruded by the second extruding mechanism 200 by the second heating member 400, the flowability of the material input into the first extruding mechanism 100 can be ensured, so that the material extruded by the second extruding mechanism 200 can be better mixed by the first screw 130, and the mixing effect of the material is improved; by heating and keeping warm the mixed material of the second extruding mechanism 200 by the first heating member 300, the mixed material can maintain sufficient temperature and high flowability before extrusion, so that the mixed material can be smoothly extruded through the nozzle 140, and the difficulty or uneven extrusion of the mixed material through the nozzle 140 can be avoided.

[0071] Preferably, in order to fix the material extruding device 10 on the 3D printer body to move with the 3D printer body, as shown in the figures, a mounting member 150 is arranged in the first extruding mechanism 100, and the material extruding device 10 is fixed on the 3D printer body 20 by the mounting member 150. Figure 1 and Figure 2 Preferably, in order to fix the material extruding device 10 on the 3D printer body to move with the 3D printer body, as shown in the figures, a mounting member 150 is arranged in the first extruding mechanism 100, and the material extruding device 10 is fixed on the 3D printer body 20 by the mounting member 150.​

[0072] The material extruding 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 extruding device is realized by the movement of the 3D printer body.

[0073] Most 3D printers, especially FDM (Fused Deposition Modeling) printers based on Cartesian coordinate system, control the position of the print head (i.e. the material extruding device 10) through the precise movement of three main axes (X, Y, Z axes). When the 3D printer receives a printing task, it first calculates the path and speed that the material extruding device 10 needs to move according to the data of the 3D model, and then the control system drives the 3D printer body to move along the X, Y, Z axes to drive the material extruding device 10 to the preset position. At the preset position, the material extruding device 10 starts to work and extrudes the material through the nozzle 140. As the 3D printer body continues to move, the material extruding device 10 extrudes the material layer by layer according to the preset path, gradually constructing a 3D model.

[0074] In the embodiment of the present application, the first motor 120 is connected to the first barrel 110 through the mounting piece 150, and the output shaft of the first motor 120 is connected with the first screw 130 through the mounting piece 150. Specifically, the mounting piece 150 is provided with the first motor 120 at one end and is in communication with the first barrel 110 at the other end, so that the output shaft of the first motor 120 can be fixedly connected with the first screw 130 through the mounting piece 150. Wherein, the first motor 120 can be fixed on the mounting piece 150 through the mounting flange 111 as shown, and the specific way can refer to the way of fixing the second motor 230 on the material storage bin 220, which will not be described here. Figure 1

[0075] By fixedly connecting the mounting piece 150 with the 3D printer body, specifically, threaded holes can be formed on the mounting piece 150 and the 3D printer body, and the mounting piece 150 can be fixedly connected with the 3D printer through threaded fasteners, so that the material extruding device 10 can be moved to the preset position with the 3D printer body, and the material can be extruded through the nozzle 140 at the preset position for printing.

[0076] According to another aspect of the embodiment of the present application, a 3D printer is provided, which comprises a 3D printer body and the material extruding device provided by any one of the above embodiments. The material extruding device is fixedly connected with the 3D printer body.

[0077] ​In order to enable the material extrusion device to accurately extrude mixed materials with different proportions, and enable the 3D printer to realize automatic printing with mixed materials with different material proportions, the application further provides a printing method, which is applied to the material extrusion device 10 provided by any one of the above embodiments, and is used for mixing and extruding mixed materials for printing according to a preset proportion. The method is applied to a 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 The flowchart of the printing method provided by the embodiment of the application is shown in the figure. As shown in the figure, the printing method comprises the following steps:

[0078] Step S100: Obtain a printing proportion.

[0079] Specifically, the printing proportion can be input to the controller of the material extrusion device. The printing proportion is the proportion between different materials in the mixed materials extruded by the first extrusion mechanism through the nozzle. For example, when the material extrusion device is provided with two second extrusion mechanisms, the proportion between material A and material B in the mixed materials can be 2:8, and when the material extrusion device is provided with three second extrusion mechanisms, the proportion between material A, material B and material C in the mixed materials can be 2:6:2.

[0080] Step S200: Determine the speed ratio between the plurality of second motors according to the printing proportion.

[0081] Since the proportion 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 proportion, the speed ratio between the plurality of second motors can be determined according to the printing proportion, and then the actual speed of each second motor can be calculated through the speed ratio. Taking the case that the material extrusion device is provided with two second extrusion mechanisms as an example, when the proportion between material A and material B in the mixed materials is 2:8, the speed ratio between the two second motors is determined to be 2:8, and then the actual speed of each second motor can be calculated according to the speed ratio. For example, the speed of the first second motor can be calculated to be 600 rpm, and the speed of the second second motor can be calculated to be 2400 rpm.

[0082] Step S300: Control the plurality of second motors to operate at the speed ratio and drive the corresponding second screw to rotate, so that the first screw mixes and extrudes the materials extruded by the plurality of second screws according to the printing proportion for printing.

[0083] After the actual rotation speeds of each second motor are determined according to the rotation speed ratio between the plurality of second motors, each second motor can be controlled to operate at its corresponding actual rotation speed, for example, the first second motor is controlled to operate at a rotation speed of 600 rpm, and the second second motor is controlled to operate at a rotation speed of 2400 rpm, so that the first second motor drives its corresponding second screw to rotate at a rotation speed of 600 rpm, and the second second motor drives its corresponding second screw to rotate at a rotation speed of 2400 rpm, so that the two second motors control the two second screws to rotate at a rotation speed ratio of 2:8, so that the two second screws extrude 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, and then the first screw mixes the material extruded by each second screw under the driving of the first motor, and extrudes the mixed material with a material ratio of, for example, 2:8, for printing the 3D model.

[0084] It should be noted that the rotation speed of the first motor of the first extrusion mechanism can remain constant, which can be calculated according to the layer height of the model to be printed and the aperture of the nozzle, for example. For example, the first motor can always operate at a rotation speed of 2000 rpm.

[0085] In the embodiments of the present application, the rotation speed ratio between the plurality of second motors is determined according to the printing ratio, and the plurality of second motors are controlled to operate at the rotation speed ratio, so that the plurality of second motors drive the corresponding plurality of second screws to rotate at the rotation speed ratio, and the plurality of second screws extrude the material according to the printing ratio, and then the first screw can mix and extrude the material extruded by the second screw according to the printing ratio. Through the above-mentioned manner, by setting the printing ratio, the material extrusion device can accurately mix and extrude the mixed material according to the actual required ratio for printing, the printing of the 3D model using different ratios of mixed material is realized, and by setting a fixed printing ratio, the plurality of second motors can be controlled to always operate at a fixed rotation speed ratio, so that the first screw can always mix and extrude the material extruded by the plurality of second screws according to the printing ratio, ensuring the consistency and stability of the material mixing in the entire printing process, so that the automatic printing of the 3D model can be performed at a fixed material ratio, and a high-efficiency and reliable printing experience can be provided when printing a 3D model with strict requirements on the material mixing ratio.

[0086] In some application scenarios, for example, when printing a multi-layer 3D model, it is assumed that the first layer to the twentieth layer needs to be supported by a harder mixed material, so the material ratio needs to be set to 2:8, and from the twentieth layer 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.

[0087] Therefore, in order to meet the requirement of different proportions of mixed materials in different layers to optimize the structure or performance of the model, the material extrusion device needs to be controlled to extrude different proportions of mixed materials in different layers for printing, according to some embodiments of the present application, please refer to Figure 6 , Figure 6 The flowchart of the printing method provided by the embodiments of the present application is shown in the figure, which includes the following steps:

[0088] 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.

[0089] Taking a 3D model of 10 layers for example, the first printing ratio (for example, the ratio between material A and material B) can be 2:8, and the corresponding first printing interval can be the first layer to the fifth layer. The second printing ratio (for example, the ratio between material A and material B) can be 5:6, and the corresponding second printing interval can be the sixth layer to the tenth layer. Taking the sum of the length of each layer of the multi-layer 3D model as an example, assuming that the total printing length is 100 meters, the first printing ratio can be 1:9, the corresponding first printing interval can be 0 to 50 meters, and the second printing ratio can be 7:3, the corresponding second printing interval can be 51 to 100 meters.

[0090] Step S210: determining the speed ratio between the plurality of second motors in the first printing interval according to the first printing ratio, and determining the speed ratio between the plurality of second motors in the second printing interval according to the second printing ratio.

[0091] Taking the material extrusion device provided with two second extrusion mechanisms for 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 according to the first printing ratio (2:8), and the actual speed of each second motor in the first printing interval can be calculated through the speed ratio (2:8). In addition, the speed ratio between the two second motors in the second printing interval can be determined according to the second printing ratio (5:6), and the actual speed of 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 600 rpm, and the speed of the second second motor is 2400 rpm; in the second printing interval, the speed of the first second motor is 1500 rpm, and the speed of the second second motor is 1800 rpm.

[0092] Step S310: In the first printing interval, control the multiple second motors to run at the corresponding speed ratio of the first printing interval and drive the corresponding second screws to rotate, so that the first screw mixes and extrudes the materials extruded by the multiple second screws according to the first printing ratio.

[0093] Specifically, when printing the first printing interval, for example, printing the first layer to the fifth layer, control the multiple second motors to run at the corresponding speed ratio of the first printing interval, for example, control the first second motor to run at a speed of 600 rpm, control the second second motor to run at a speed of 2400 rpm, so that the first second motor drives the corresponding second screw to rotate at a speed of 600 rpm, and the second second motor drives the corresponding second screw to rotate at a speed of 2400 rpm, 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 extrude the materials stored in the material storage bin into the second barrel according to the first printing ratio of 2:8, and extrude the materials in the second barrel into the first barrel according to the first printing ratio of 2:8, and then the first screw mixes the materials extruded by each second screw under the drive of the first motor, and extrudes the mixed materials with a ratio of the first printing ratio, for example, 2:8, for printing the first layer to the fifth layer of the 3D model.

[0094] Step S320: Control the multiple second motors to run at the corresponding speed ratio of the second printing interval and drive the corresponding second screws to rotate, so that the first screw mixes and extrudes the materials extruded by the multiple second screws according to the second printing ratio.

[0095] When printing the second printing interval, for example, printing the sixth layer to the tenth layer, control the multiple second motors to run at the corresponding speed ratio of the second printing interval, for example, control the first second motor to run at a speed of 1500 rpm, control the second second motor to run at a speed of 1800 rpm, so that the first second motor drives the corresponding second screw to rotate at a speed of 1500 rpm, and the second second motor drives the corresponding second screw to rotate at a speed of 1800 rpm, 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 extrude the materials stored in the material storage bin into the second barrel according to the second printing ratio of 5:6, and extrude the materials in the second barrel into the first barrel according to the second printing ratio of 5:6, and then the first screw mixes the materials extruded by each second screw under the drive of the first motor, and extrudes the mixed materials with a ratio of the second printing ratio, for example, 5:6, for printing the sixth layer to the tenth layer of the 3D model.

[0096] In the embodiments of the present application, by setting the first printing ratio corresponding to the first printing interval and the second printing ratio corresponding to the second printing interval, and determining the corresponding speed ratio between the plurality of second motors in the first printing interval and the second printing interval according to the first printing ratio and the second printing ratio, and then controlling the plurality of second motors to run at the corresponding speed ratio between the first printing interval and the second printing interval when printing the first printing interval and the second printing interval, the material extrusion device can be controlled to extrude the mixed material with the first printing ratio for printing when printing the first printing interval, and the mixed material with the second printing ratio for printing when printing the second printing interval, achieving the purpose of printing different proportions of mixed materials at different layers, seamlessly connecting the material requirements of different layers, and realizing efficient and precise automatic printing.

[0097] 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 to adjust the hardness, elasticity, electrical 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 meet the different hardness and elasticity requirements of human tissues.

[0098] In order to print the 3D model with the above-mentioned gradient characteristics, it is necessary to control the material extrusion device to extrude different proportions of mixed materials when printing each layer or each segment, and the material proportion changes the same between adjacent layers or adjacent segments. According to some embodiments of the present application, optionally, please refer to Figure 7 , Figure 7 The flowchart of the printing method provided by the embodiments of the present application is shown in the figure, which includes the following steps:

[0099] Step S120: obtaining a printing ratio and a total number of interval 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.

[0100] Taking printing a 3D model of 101 layers as an example, the total number of interval 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 the first layer. 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 the 101st layer.

[0101] In some embodiments, assuming that the total printing length of a multi-layer 3D model to be printed is 100 meters, the total printing length is divided into 20 parts, each part has a printing length of 5 meters, the total number of interval intervals is 19, the first printing interval corresponding to the starting printing ratio is the first part, that is, 0-5 meters, and the last printing interval corresponding to the final printing ratio is the 20th part, that is, 96-100 meters.

[0102] Step S220: determining the starting speed ratio of each second motor according to the starting printing ratio, and determining the final speed ratio of each second motor according to the final printing ratio.

[0103] 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 of material A is 8, the starting printing ratio of material B is 9 and the final printing ratio of material B is 2, that is, the starting speed ratio of the second motor of the second extrusion mechanism inputting material A is 1, the final speed ratio of the second motor of the second extrusion mechanism inputting material A is 8, the starting speed ratio of the second motor of the second extrusion mechanism inputting material B is 9, and the final speed ratio of the second motor of the second extrusion mechanism inputting material B is 2.

[0104] Step S230: determining the speed ratio change between adjacent two printing intervals of each second motor according to the starting speed ratio, the final speed ratio and the total number of interval intervals.

[0105] After determining the starting speed ratio and the final speed ratio of each second motor, for example, when the starting speed ratio of the first second motor is 1 and the final speed ratio of the first second motor is 8, the speed ratio change between adjacent two printing intervals of the first second motor can be calculated by the starting speed ratio, the final speed ratio and the total number of interval intervals of the first second motor, and the speed ratio change can be calculated according to the following formula: speed ratio change=(final speed ratio-starting speed ratio) / total number of interval intervals.

[0106] For example, when the total number of interval intervals is 100, the starting printing ratio is 1:9 and the final printing ratio is 8:2, the speed ratio change of the first second motor is r1 is: r1=(8-1) / 100=0.07, the speed ratio change of the second second motor is r2 is: r2=(2-9) / 100=-0.07.

[0107] Step S240: determining the speed ratio between a plurality of second motors in each printing interval according to the starting speed ratio and the speed ratio change.

[0108] Specifically, the rotation speed ratio of the second motor corresponding to the material A in each printing interval = the initial rotation speed ratio + the rotation speed ratio change amount of the previous printing interval of the current printing interval. The rotation speed ratio can be calculated according to the following formula:

[0109] The rotation speed ratio of the i-th printing interval = the initial rotation speed ratio + the rotation speed ratio change amount of the (i-1)-th printing interval.

[0110] For example, when the initial rotation speed ratio of the first second motor is 1 and the rotation speed ratio change amount is 0.07, the rotation speed ratio r5 of the first second motor in the fifth printing interval is r5 = 1 + (5-1) x 0.07 = 1.28. When the initial rotation speed ratio of the second second motor is 9 and the rotation speed ratio change amount of the second second motor is -0.07, the rotation speed ratio r5 of the second second motor in the fifth printing interval is r5 = 9 + (5-1) x (-0.07) = 8.28.

[0111] After determining the rotation speed ratio of each second motor in each printing interval, the rotation speed ratio corresponding to each printing interval between the plurality of second motors can be determined, and the actual rotation speed corresponding to each printing interval of each second motor can be calculated.

[0112] 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, the rotation speed ratio corresponding to the fifth printing interval between the two second motors is 1.28:8.72. Then, according to the rotation speed ratio 1.28:8.72, the actual rotation speed corresponding to the fifth printing interval of each second motor can be calculated. For example, the rotation speed of the first second motor in the fifth printing interval is 256 rpm, and the rotation speed of the other second motor in the fifth printing interval is 1744 rpm.

[0113] Step S330: In each printing interval, control the plurality of second motors to run at the rotation speed ratio corresponding to the printing interval and drive the corresponding second screw to rotate, so that the first screw mixes and extrudes the material extruded by the plurality of second screws according to the printing proportion corresponding to the printing interval.

[0114] Specifically, when printing each printing interval, for example, printing the fifth printing interval, the multiple second motors are controlled to operate at a speed ratio corresponding to the fifth printing interval, for example, the first second motor is controlled to operate at a speed of 256 rpm, and the second second motor is controlled to operate at a speed of 1744 rpm, so that the first second motor drives the corresponding second screw to rotate at a speed of 256 rpm, and the second second motor drives the corresponding second screw to rotate at a speed of 1744 rpm, so that the two second motors control the two second screws to rotate at a speed ratio of 1.28:8.72.

[0115] Since the speed ratio between the multiple second motors corresponding to each printing interval is one-to-one with the printing ratio of each printing interval, for example, when the speed ratio between the two second motors in the fifth printing interval is 1.28:8.72, the printing ratio of the fifth printing interval is 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 extrude the material stored in the storage bin into the second barrel according to the printing ratio 1.28:8.72 corresponding to the fifth printing interval, and extrude the material in the second barrel into the first barrel at a printing ratio of 1.28:8.72, and then the first screw is driven by the first motor to mix the material extruded by each second screw, and extrude the mixed material with a printing ratio of 1.28:8.72, which is used to realize the printing of the fifth printing interval of the 3D model.

[0116] In the above manner, the first screw can gradually transition the proportion of the material extruded by the multiple second screws from the initial printing ratio to the final printing ratio in a manner of uniform change of the printing proportion change amount, realize the gradual change of the material proportion between the first printing interval and the last printing interval, ensure the accuracy and continuity of the material proportion change of each printing interval, and print the 3D model with the gradient characteristic to meet the visual effect or gradient function demand of the user.

[0117] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; 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 be covered in the scope of the claims and the specification of the present application. Especially, as long as there is no structural conflict, each technical feature mentioned in each embodiment can be combined in any way. The present application is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

Claims

1. A material extrusion device, used in a 3D printer, characterized in that, The material extrusion device comprises 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 the first motor, 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 with the first motor; Each of the second extrusion mechanisms comprises a second barrel, a storage bin, a second motor, a second screw and a feeding bin, in each of the second extrusion mechanisms, two ends of the second barrel are respectively communicated with the first barrel and one end of the storage bin, the other end of the storage bin is provided with the second motor, the storage bin is further communicated with the feeding bin, and the second screw is arranged in the second barrel and one end of the second screw is connected with the second motor through the storage bin; In each of the second extrusion mechanisms, the storage bin is used for storing the material input from the feeding bin, and the second motor is used for driving the second screw to rotate so as to extrude the material stored in the storage bin into the second barrel and extrude the material in the second barrel into the first barrel; The first screw is used for mixing the materials extruded into the first barrel from different extrusion mechanisms and then extruding the mixed materials through the nozzle.

2. The material extrusion apparatus of claim 1, wherein, In each of the second extrusion mechanisms, the size of the storage bin along the radial direction of the second screw is greater than the size of the second barrel along the radial direction of the second screw.

3. The apparatus of claim 1, wherein, In each of the second extrusion mechanisms, a funnel structure is arranged at the position of the second barrel communicated with the storage bin, a guide gap is formed on the wall of the lower opening of the funnel structure, and the slope of the guide gap is greater than the slope of the funnel structure.

4. The apparatus of claim 1, wherein, Each feeding bin is used for inputting different materials, and each second screw is used for rotating at different speeds under the driving 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, extrude the material in the corresponding second barrel into the first barrel at different rates, and then make the first screw mix and extrude the materials extruded from different second barrels in the first barrel at a predetermined ratio.

5. The apparatus of claim 1, wherein, The two second extrusion mechanisms are symmetrically arranged on the two sides of the first extrusion mechanism, and the two second extrusion mechanisms and the first extrusion mechanism jointly form a Y-shaped structure. In each of the second extrusion mechanisms, the feeding bin is arranged on the side of the storage bin facing the first extrusion mechanism, and the shape of the feeding bin is matched with the gap between the first extrusion mechanism and the storage bin and the second motor.

6. The material extrusion apparatus of claim 5, wherein, In each of the second extrusion mechanisms, the volume of the feeding bin is greater than the volume of the storage bin.

7. The material extrusion apparatus of claim 5, wherein, The first extrusion mechanism further comprises a mounting member, the first motor is connected to the first barrel through the mounting member, and the output shaft of the first motor is connected with the first screw through the mounting member; The mounting member is further used for being connected with a 3D printer body to fix the material extrusion device on the 3D printer body.

8. The apparatus of claim 1, wherein, The material extruding device further comprises a first heating member arranged on the first barrel for heating the mixed material in the first barrel, and at least two second heating members arranged on the second barrel for heating the material in the second barrel.

9. The apparatus of claim 1, wherein, The first barrel is outwardly protruding and provided with a protruding block, the second barrel is connected to the protruding block, and the protruding block is provided with channels respectively communicating with the first barrel and the second barrel, the channels being used for allowing the material extruded from the second barrel to enter the first barrel.

10. A 3D printer characterized by, The 3D printer comprises a 3D printer body and the material extruding device according to any one of claims 1-9, and the material extruding device is fixedly connected to the 3D printer body.

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