Multi-material 3D printing device and method based on rotating structure

Abstract

According to the multi-material 3D printing device and method based on the rotating structure, a rotating cylindrical base table serves as a printing tray, the axis of the rotating cylindrical base table serves as a center line, and a multi-nozzle collaborative printing function of multiple wires is provided by expanding a plurality of printing nozzle units; movement of the printing nozzle units does not interfere with one another, so that the multi-material 3D printing requirement based on the FDM technology is met, the advantage of efficient batch printing is achieved, the equipment structure fully utilizes the forming space of the rotary cylindrical base table, the mechanical design structure is compact, the space utilization rate is high, the printing efficiency is high, and the equipment structure is stable and reliable. The maintenance threshold of multi-material equipment can be lowered, and the desktop miniaturization development requirement of the multi-material 3D printing equipment can be effectively met.

Description

Technical Field

[0001] The present invention belongs to the technical field of 3D printing and specifically relates to a multi-material 3D printing device and method based on a rotating structure. Background Art

[0002] 3D printing technology, also known as additive manufacturing technology, is a technology that uses a gradual accumulation of materials to manufacture physical parts. Compared with traditional material removal-cutting processing technology, it is a "bottom-up" manufacturing method. Based on the unique advantages of 3D printing technology, this technology has changed the design and manufacturing process of products. It is regarded as an "accelerator" of scientific and technological innovation in many fields and a key basic technology to support the innovative development of the manufacturing industry. At the same time, it has further changed the production model of products and driven customized, personalized, and distributed manufacturing. There are many types of 3D printing technology processes. According to different process principles, they can be roughly divided into seven major process types, namely material extrusion process, powder bed fusion process, binder jetting process, material jetting process, stereolithography process, thin layer lamination process, and directed energy deposition process.

[0003] At present, as a typical representative of material extrusion process, the principle of FDM (Fused Deposition Modeling) technology is to use polymer (commonly known as plastic) thermoplastic filaments as printing consumables, such as PLA (PolyLactic Acid), ABS (Arcylonitrile Butadiene Styrene), etc., by controlling the filament to enter the print head, by controlling the heating temperature inside the print head, completing the melting change of the printing filament inside the print head, realizing the plasticization of the printing material from solid to molten state, and extruding the molten material through the nozzle structure at the end of the print head, and the extruded molten material is cooled by the fan at the end of the print head, thereby completing the transformation from molten state to solid state. At the same time, the above process cooperates with the motion system of the FDM equipment to process the extruded molten material from point to line, from line to surface, and then from surface to body according to the pre-planned printing path, and finally realizes the molding and printing of 3D digital models. Due to the relatively simple process principle of FDM technology, low hardware construction cost, simple equipment operation and easy maintenance, it is very suitable for home desktop 3D printing application scenarios, which has promoted the application and promotion of FDM technology in the field of consumer products, especially in the automotive manufacturing industry, design field, medical field, education field and cultural field. The mainstream equipment feature of FDM technology is that it supports single-head monochrome 3D printing, and the printed parts have the advantages of high molding accuracy and good printing model performance.

[0004] Multi-material 3D printing based on FDM process is the development trend of FDM technology. At present, a variety of technical means have been proposed to realize multi-material FDM printing technology. The first category is a multi-material 3D printing device and method based on nozzle selection. The typical feature of this type of equipment is that the printing nozzle can be replaced freely, similar to the automatic tool changing system of a CNC milling machine. For example, invention patent 202410477504.6 discloses a 3D printer with multi-nozzle switching, a nozzle grabbing docking and separation method and a control method. The typical feature of the invention method is that the color splicing printing of the FDM device is realized by replacing the printing nozzle. Each print head is only responsible for printing one kind of wire material, and the print head has a complete wire feeding mechanism and a hot end structure, and is equipped with a corresponding male connector structure. A female connector structure is configured at the motion structure terminal of the Cartesian coordinates (XYZ) of the device, and multi-color 3D printing is realized by selecting male connector printing nozzles of different printing wire materials on the female connector structure of the above-mentioned printing device terminal. However, the 3D printing method based on nozzle selection has low printing efficiency. This is because only one nozzle is loaded to the end of the motion unit at a time, and the internal heating function of the printing nozzle is activated only when it is in the working state. When the nozzle is switched from the non-working state to the working state, it takes a certain amount of time to complete the automatic replacement of the nozzle and a certain amount of time to heat the nozzle to the specified heating temperature before the subsequent printing task can be completed.

[0005] The second category is a multi-material 3D printing structure and method based on a fixed form of multiple print heads. The typical feature of this type of FDM equipment is that the print heads or the improved print heads with a multi-nozzle structure are fixed together, and they all move with the moving structure terminal. The most common is an FDM printing device with two sets of nozzle structures, one set is used to print model filament materials, and the other set is often used to print support filaments. The disadvantage of this structure is that the multiple print heads are fixed together, thereby limiting the printing space of the moving structure, or the size of the printing device has to be increased to meet the fixed movement of the multiple nozzles. On the other hand, because the multiple nozzles are fixed together, the load on the moving terminal of the equipment is very heavy, and appropriate acceleration and deceleration need to be set to ensure the printing quality. The invention patent 201911418244.0 discloses a material 3D printing structure with replaceable nozzles. By designing the printing state of the replaceable head supporting multiple materials, it reduces the load of the print head of the mobile terminal while improving the ability to print multiple materials. Therefore, the design of the multi-material nozzle structure puts forward new requirements to ensure that the multi-material nozzle is smoothly replaced in material replacement and nozzle replacement.

[0006] The third category is a multi-material 3D printing structure and method in which multiple nozzle structures participate in the printing process separately. The typical feature of this type of FDM equipment is that the movement of each nozzle is independent of each other, and the interference problem of the movement of each nozzle needs to be considered. For example, the invention patent 202110649495.0 discloses a cylindrical coordinate multi-nozzle FDM3D printer and its printing method. The invention method uses a cylindrical coordinate (r-θ-z) motion structure to replace the conventional Cartesian coordinate (xyz) motion structure to construct a 3D printing device with multiple nozzles. The vertical motion structure is responsible for the Z-axis movement, and each radial motion unit is responsible for the R-axis movement of the corresponding printing nozzle. Multiple radial motion units are uniformly fixed and mounted on the vertical motion structure. Finally, a ring-shaped printing platform unit is used at the bottom of the vertical motion structure to rotate the θ-axis movement. The printing method controls the rotation angle of the ring-shaped printing platform to rotate the printing work area to the corresponding nozzle work area, thereby realizing the coordinated printing of the multi-nozzle structure. However, this type of cylindrical coordinate-based multi-nozzle printing method reduces the efficiency of multi-material FDM printing. This is because after completing the printing task of each material nozzle, the annular printing platform needs to be rotated to complete the printing task of the next material nozzle. The utilization rate of the annular printing platform is not high, and the equipment structure is relatively complex and large, which is not conducive to the desktop miniaturization development of multi-material FDM equipment.

[0007] In summary, in the above-disclosed multi-material FDM printing technology, either the equipment structure is too complex, which puts forward high requirements on the structural design of the equipment, or the implementation method is relatively complicated, resulting in a high maintenance threshold for the equipment, which is not conducive to the application and promotion of the miniaturized desktop market of multi-material FDM printing technology. Summary of the invention

[0008] In order to solve the above problems, the present invention proposes a multi-material 3D printing device and method based on a rotating structure.

[0009] The multi-material 3D printing device based on a rotating structure of the present invention includes: a rotating cylindrical base, one end of the rotating cylindrical base is connected to a base power device, the rotating cylindrical base is horizontally installed above a base through a fixed block, and the fixed block is arranged at one end of the base; a printing nozzle unit, there are multiple printing nozzle units, the multiple printing nozzle units are distributed along the radial direction of the rotating cylindrical base, and the printing nozzle unit is arranged at the other end of the base; a nozzle, the nozzle is installed on the printing nozzle unit, the multiple nozzles are all facing the rotating cylindrical base, and the nozzle can move axially and radially along the rotating cylindrical base.

[0010] The printing nozzle unit comprises nozzle unit 1, nozzle unit 2 and nozzle unit 3. The nozzle unit 2 is arranged vertically, and the nozzle unit 1 and the nozzle unit 3 are respectively installed obliquely on both sides of the nozzle unit 2.

[0011] The second nozzle unit includes a Z-axis 2 and an X-axis 2 which are perpendicular to each other. The Z-axis 2 is vertically arranged, and the bottom of the Z-axis 2 is fixedly connected to the base. The X-axis 2 is arranged along the axial direction of the rotating cylindrical base. A nozzle is installed on the X-axis 2, and the nozzle is located above the rotating cylindrical base.

[0012] A Z-axis 2 power device is arranged on the Z-axis 2, and the Z-axis 2 power device is connected to one end of the X-axis 2. The Z-axis 2 power device drives the X-axis 2 to move up and down along the Z-axis 2. An X-axis 2 power device is arranged on the X-axis 2, and the X-axis 2 power device is connected to the nozzle on the X-axis 2. The X-axis 2 power device can drive the nozzle to move left and right along the X-axis 2.

[0013] The first nozzle unit is provided with a corresponding Z-axis one power device and an X-axis one power device, and the third nozzle unit is provided with a Z-axis three power devices and an X-axis three power devices.

[0014] The base power device, Z-axis one power device, X-axis one power device, Z-axis two power devices, X-axis two power devices, Z-axis three power devices and X-axis three power devices are one of motors, gear sets, synchronous belts and screw rod structures.

[0015] The printing method of the multi-material 3D printing device based on the rotating structure of the present invention comprises the following steps:

[0016] S1. Slicing and path planning of a three-dimensional digital model composed of multiple colors;

[0017] S2. Printing process of a 3D printing device based on a rotating cylindrical base.

[0018] The S1 comprises the following steps:

[0019] S11. Converting the color three-dimensional digital model to obtain multiple sub-grid models representing different colors, wherein the sub-grid models constitute an overall color grid model;

[0020] S12. performing model affine transformation processing on the obtained overall color grid model;

[0021] S13. Slice the overall color grid model after affine transformation and perform layer-by-layer path planning to obtain hierarchical planning path data corresponding to the overall color grid model after affine transformation. These data are used to subsequently drive the nozzle unit of the corresponding printing material.

[0022] The slicing process comprises:

[0023] S131. directly use the classic STL plane slicing algorithm to slice the entire color grid model after affine transformation to obtain the contour data after slicing;

[0024] S132. Perform path planning on the sliced ​​contour data;

[0025] S133. After being processed by S131 and S132, the hierarchical planning path data corresponding to each sub-grid model after affine transformation is obtained.

[0026] The S2 comprises the following steps:

[0027] S21. Establishing a one-to-one correspondence between each sub-grid model in the color three-dimensional model and a nozzle unit of a specific printing material, as well as an absolute position relationship corresponding to the working space of each nozzle unit;

[0028] S22. Process the path information of the current slice layer k of each sub-grid model according to the obtained hierarchical path data after slicing each sub-grid model, where k starts from 1, that is, control each print head unit to print according to the path information until the slice filling paths of all sub-grid models are printed;

[0029] S23. According to step S22, continue to process the k+1 layer slice path data of each sub-grid model until all slice paths are printed.

[0030] The beneficial effect of the present invention is that by utilizing a rotating cylindrical base as a printing tray, taking the axis of the rotating cylindrical base as the center line, and expanding multiple printing nozzle units, a collaborative printing function of multiple nozzles for multiple filaments is provided, and the movements of each printing nozzle unit do not interfere with each other, thereby meeting the multi-material 3D printing needs based on the FDM process and having the advantage of high-efficiency batch printing. The equipment structure of the present invention fully utilizes the molding space of the rotating cylindrical base, has a compact mechanical design structure, high space utilization, high printing efficiency, and a stable and reliable equipment structure. It can reduce the maintenance threshold of multi-material equipment and can effectively meet the desktop miniaturization development requirements of multi-material 3D printing equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The structure of the present invention is schematically shown in FIG. Figure 1 .

[0032] Figure 2 The structure of the present invention is schematically shown in FIG. Figure 2 .

[0033] Figure 3 It is a side view of the rotating cylindrical base and the mesh model of the present invention before affine transformation.

[0034] Figure 4 It is a side view of the rotating cylindrical base and the mesh model of the present invention after affine transformation.

[0035] Figure 5 It is a flow chart of the printing method of the present invention.

[0036] Reference numerals:

[0037] Rotating cylindrical base 1; base 2; fixed block 3; Z axis two 4; X axis two 5; nozzle 6; Z axis one 7; X axis one 8; Z axis three 9; X axis three 10. DETAILED DESCRIPTION

[0038] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0039] like Figure 1-Figure 2 As shown, the multi-material 3D printing device based on the rotating structure of the present invention comprises: a rotating cylindrical base 1, a printing nozzle unit and a nozzle 6, one end of the rotating cylindrical base 1 is connected to the base power device, the rotating cylindrical base 1 and the base power device are horizontally installed above the base 2 through a fixed block 3, and the fixed block 3 is set at one end of the base 2; the base power device can drive the rotating cylindrical base 1 to rotate in the horizontal direction. There are multiple printing nozzle units, and the multiple printing nozzle units are distributed along the radial direction of the rotating cylindrical base 1, and the printing nozzle unit is set at the other end of the base 2; the nozzle 6 is installed on the printing nozzle unit, and the multiple nozzles 6 are all facing the rotating cylindrical base 1, and the nozzle 6 can move axially and radially along the rotating cylindrical base 1.

[0040] Specifically, the print head unit includes a nozzle unit 1, a nozzle unit 2 and a nozzle unit 3, and the print head units are not limited to three. The nozzle unit 2 is vertically arranged, and the nozzle unit 1 and the nozzle unit 3 are respectively obliquely installed on both sides of the nozzle unit 2. The angles between the nozzle unit 1 and the nozzle unit 3 and the nozzle unit 2 can be set to corresponding angles as needed, generally acute angles. The nozzle unit 2 includes a Z-axis 2 4 and an X-axis 2 5 that are perpendicular to each other, the Z-axis 2 4 is vertically arranged, and the bottom of the Z-axis 2 4 is fixedly connected to the base 2, the X-axis 2 5 is arranged on the Z-axis 2 4 along the axial direction of the rotating cylindrical base 1, and a nozzle 6 is installed on the X-axis 2 5, and the nozzle 6 is located above the rotating cylindrical base 1.

[0041] A Z-axis 2 power device is arranged on the Z-axis 2 4 , and the Z-axis 2 power device is connected to one end of the X-axis 2 5 , and the Z-axis 2 power device drives the X-axis 2 5 to move up and down along the Z-axis 2 4 , and an X-axis 2 power device is arranged on the X-axis 2 5 , and the X-axis 2 power device is connected to the nozzle 6 on the X-axis 2 5 , and the X-axis 2 power device can drive the nozzle 6 to move left and right along the X-axis 2 5 .

[0042] The nozzle unit 1 includes a Z-axis 7 and an X-axis 8 which are perpendicular to each other, and the nozzle unit 3 includes a Z-axis 9 and an X-axis 10 which are perpendicular to each other. The nozzle unit 1 is provided with a corresponding Z-axis 1 power device and an X-axis 1 power device, and the nozzle unit 3 is provided with a Z-axis 3 power device and an X-axis 3 power device.

[0043] The Z-axis 7 is tiltedly arranged at one side of the Z-axis 4, a Z-axis power device is arranged on the Z-axis 7, the Z-axis power device is connected to one end of the X-axis 7, the Z-axis power device drives the X-axis 8 to move up and down along the Z-axis 7, an X-axis power device is arranged on the X-axis 8, the X-axis power device is connected to the nozzle 6 on the X-axis 8, and the X-axis power device can drive the nozzle 6 to move left and right along the X-axis 8.

[0044] The Z-axis three 9 is tilted and arranged on the other side of the Z-axis two 4. The Z-axis three power device is arranged on the Z-axis three 9. The Z-axis three power device is connected to one end of the X-axis three 10. The Z-axis three power device drives the X-axis three 10 to move up and down along the Z-axis three 9. The X-axis three power device is arranged on the X-axis three 10. The X-axis three power device is connected to the nozzle 6 on the X-axis three 10. The X-axis three power device can drive the nozzle 6 to move left and right along the X-axis three 10.

[0045] The rotating cylindrical base 1 can be used as the Y-axis, and the base power device can be regarded as the Y-axis motor, which is responsible for the rotation of the rotating cylindrical base. Taking the axis of the rotating cylindrical base 1 as the center line, multiple printing nozzle units are distributed radially perpendicular to the center line. The nozzle 6 in the printing nozzle unit is responsible for the heating and extrusion functions of the printing wire of a single material. Different printing nozzle units are independent of each other in their respective X-axis and Z-axis movement dimensions, thereby ensuring the synergy of multiple nozzles and avoiding the mutual interference problem between the movements of each nozzle.

[0046] The base power device 1, the Z-axis power device 1, the X-axis power device 1, the Z-axis power device 2, the X-axis power device 2, the Z-axis power device 3 and the X-axis power device 3 are one of the motor, gear set, synchronous belt and screw rod structures. The base power device and the rotating cylindrical base 1 can be driven by a motor, a gear set or a synchronous belt. The Z-axis is driven by a screw rod, and the X-axis is driven by a synchronous belt.

[0047] The printing method of the multi-material 3D printing device based on the rotating structure of the present invention comprises the following steps:

[0048] S1. Slicing and path planning of a three-dimensional digital model composed of multiple colors;

[0049] S11. The color three-dimensional digital model is transformed to obtain multiple sub-grid models representing different colors, that is, each sub-grid model represents a closed space inside the three-dimensional space of the original color three-dimensional digital model, and the space is assigned a color attribute of a specific material corresponding to the original color three-dimensional digital model. In this way, the original color three-dimensional digital model is composed of the divided sub-grid models in the three-dimensional space, and these sub-grid models constitute the overall color grid model;

[0050] S12. Perform model affine transformation on the obtained overall color grid model; adopt a data processing method based on model affine transformation disclosed in invention patent 202410635234.7 to obtain the overall color grid model after affine transformation. Specifically, the following steps are included: Figure 3-Figure 4 As shown:

[0051] S121. Establish a coordinate system. The rotating 3D printing device includes a rotating cylindrical base 1 and a nozzle 6. Based on the obtained geometric information of the rotating 3D printing device, a mathematical model is established: the rotating cylindrical base 1 is horizontally projected along its central axis to obtain the XOZ plane, wherein the Z axis is vertically upward and the X axis is horizontally to the right. The highest point position of the rotating cylindrical base projection circle is taken as the origin O, and the rotation center axis direction of the rotating cylindrical base is taken as the Y axis. Accordingly, the Y axis is perpendicular to the XOZ plane and inward, thereby meeting the characteristics of the right-handed coordinate system, thereby completing the establishment of the three-dimensional coordinate system;

[0052] S122. Obtain and process the model file: obtain the model file of the three-dimensional model to be printed, perform mesh densification processing to obtain the three-dimensional mesh model, and perform mapping transformation operations on the vertices of the three-dimensional mesh model, thereby realizing the affine transformation of the three-dimensional model; the mapping transformation operation refers to traversing the model vertex coordinates in the model file, and performing a mapping transformation operation on each vertex coordinate as follows:

[0053] i. The preset model vertex is P (x, y, z), the center of the rotating cylindrical base is Q, and the rotation radius of the rotating cylindrical base is R0. Then the length between point P and the center of the rotating cylindrical base Q is L. i ;

[0054] ii. On the XOZ plane, calculate the angle between the QP ray and the QZ ray as α, where α is in radians;

[0055] iii. According to the following mapping formula, calculate the spatial coordinates P'(x', y', z') of point P after mapping.

[0056] P'(x',y',z')=(Li*α,y,Li-R0)

[0057] And P' is used as the vertex coordinates of the three-dimensional model after affine transformation.

[0058] In order to improve the accuracy of model surface details, ensure the accuracy of geometric shapes, avoid printing defects, accurately simulate physical properties and effectively generate support structures, it is necessary to perform grid densification on the printed three-dimensional model (such as STL model). The grid densification processing adopts classic grid subdivision algorithms, such as multiple Hermite space interpolation subdivision, Loop subdivision, Catmull-Clark subdivision, etc.

[0059] S13. Slice the overall color grid model after affine transformation and perform layer-by-layer path planning to obtain hierarchical planning path data corresponding to the overall color grid model after affine transformation. Since each sub-grid model does not intersect with each other in three-dimensional space, and each represents a grid model printed with a specific printing material.

[0060] The slicing process traverses the sub-grid model of each affine transformation pair, and the specific process is as follows:

[0061] S131. directly use the classic STL plane slicing algorithm to slice the whole color mesh model after affine transformation, such as the surface intersection slicing algorithm, the line surface intersection slicing algorithm and the vertical line intersection slicing algorithm, to obtain the contour data after slicing;

[0062] S132. Perform path planning on the sliced ​​contour data, and directly use the existing classic FDM path filling algorithm, such as Zigzag path filling, Contour-Parallel path filling, Spirals path filling algorithm, etc.;

[0063] S133. After processing in S131 and S132, the hierarchical planning path data corresponding to each sub-grid model after affine transformation is obtained, and these data are used for subsequently driving the nozzle unit module of the corresponding printing material.

[0064] S2. Printing process of a 3D printing device based on a rotating cylindrical base.

[0065] S21. Establish a one-to-one correspondence between each sub-grid model in the color 3D model and the nozzle unit of a specific printing material, as well as an absolute position relationship corresponding to the working space of each nozzle unit, that is, for a sub-model of a specific color, the printing nozzle i structural unit module of the corresponding material is used to complete the printing;

[0066] S22. According to the obtained hierarchical path data after slicing each sub-grid model, the path information of the current slice layer k of each sub-grid model is processed according to the following steps, where k starts from 1, that is, each print head unit is controlled to print according to the path information until the slice filling paths of all sub-grid models are printed;

[0067] S221. Calculate the printing height h of the current layer k according to the slice thickness d. The formula is as follows:

[0068] h=k*d

[0069] At the same time, the z-axis motors in each print head unit module are controlled to rotate to ensure that each print head unit is at a height h.

[0070] S222. Traverse the hierarchical path data Path of each sub-grid model. Assume that the filling path data of the current sub-grid model at the kth layer is Paht[k]. If Path[k] is not empty, rotate the rotating cylindrical base to the workspace of the print head unit i corresponding to the current sub-grid model, control the Y-axis motor, and rotate the rotating base to an absolute angle θ i Position; then use the affine plane planning path in Path[k] to obtain its corresponding x-axis path component and y-axis path component, where the x-axis path component is directly used to drive the X-axis motor in the current print head unit module to control the print head to move the corresponding printing component; the y-axis path component is directly used for the Y-axis rotation motor to control the rotating cylindrical base to move the corresponding printing component. If Path[k] is empty, it means that there is no printing path data for the kth layer of the current sub-grid model, and the rotating cylindrical base does not need to rotate the printing space, and directly processes the next sub-grid model.

[0071] S223. After processing in step S222, the Path[k] layer slice filling paths of all sub-grid models are printed.

[0072] S23. According to step S22, continue to process the k+1 layer slice path data of each sub-grid model until all slice paths are printed.

[0073] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention 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 limiting the present invention.

[0074] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0075] In the present invention, unless otherwise clearly specified and limited, the terms "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 one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0076] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0077] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0078] Although the above embodiments have been shown and described, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. Changes, modifications, substitutions and variations of the above embodiments by those of ordinary skill in the art are all within the scope of protection of the present invention.

Claims

1. A multi-material 3D printing device based on a rotating structure, characterized in that: include: A rotating cylindrical base, one end of which is connected to a base power device, and the rotating cylindrical base is horizontally mounted above the base through a fixing block, and the fixing block is arranged at one end of the base; A print head unit, wherein the print head units are multiple and distributed along the radial direction of the rotating cylindrical base, and the print head units are arranged at the other end of the base; The nozzle is installed on the printing nozzle unit, and the plurality of nozzles are all facing the rotating cylindrical base, and the nozzles can move axially and radially along the rotating cylindrical base.

2. The multi-material 3D printing device based on a rotating structure according to claim 1, characterized in that: The printing nozzle unit comprises nozzle unit 1, nozzle unit 2 and nozzle unit 3. The nozzle unit 2 is arranged vertically, and the nozzle unit 1 and the nozzle unit 3 are respectively installed obliquely on both sides of the nozzle unit 2.

3. The multi-material 3D printing device based on a rotating structure according to claim 2, characterized in that: The second nozzle unit includes a Z-axis 2 and an X-axis 2 which are perpendicular to each other. The Z-axis 2 is vertically arranged, and the bottom of the Z-axis 2 is fixedly connected to the base. The X-axis 2 is arranged along the axial direction of the rotating cylindrical base. A nozzle is installed on the X-axis 2, and the nozzle is located above the rotating cylindrical base.

4. The multi-material 3D printing device based on a rotating structure according to claim 3, characterized in that: A Z-axis 2 power device is arranged on the Z-axis 2, and the Z-axis 2 power device is connected to one end of the X-axis 2. The Z-axis 2 power device drives the X-axis 2 to move up and down along the Z-axis 2. An X-axis 2 power device is arranged on the X-axis 2, and the X-axis 2 power device is connected to the nozzle on the X-axis 2. The X-axis 2 power device can drive the nozzle to move left and right along the X-axis 2.

5. The multi-material 3D printing device based on a rotating structure according to claim 4, characterized in that: The first nozzle unit is provided with a corresponding Z-axis one power device and an X-axis one power device, and the third nozzle unit is provided with a Z-axis three power devices and an X-axis three power devices.

6. The multi-material 3D printing device based on a rotating structure according to claim 5, characterized in that: The base power device, Z-axis one power device, X-axis one power device, Z-axis two power devices, X-axis two power devices, Z-axis three power devices and X-axis three power devices are one of motors, gear sets, synchronous belts and screw rod structures.

7. A printing method of a multi-material 3D printing device based on a rotating structure according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1. Slicing and path planning of a three-dimensional digital model composed of multiple colors; S2. Printing process of a 3D printing device based on a rotating cylindrical base.

8. The multi-material 3D printing device based on a rotating structure according to claim 7, characterized in that: The S1 comprises the following steps: S11. Converting the color three-dimensional digital model to obtain multiple sub-grid models representing different colors, wherein the sub-grid models constitute an overall color grid model; S12. performing model affine transformation processing on the obtained overall color grid model; S13. Slice the overall color grid model after affine transformation and perform layer-by-layer path planning to obtain hierarchical planning path data corresponding to the overall color grid model after affine transformation. These data are used to subsequently drive the nozzle unit of the corresponding printing material.

9. The multi-material 3D printing device based on a rotating structure according to claim 8, characterized in that: The slicing process comprises: S131. directly use the classic STL plane slicing algorithm to slice the entire color grid model after affine transformation to obtain the contour data after slicing; S132. Perform path planning on the sliced ​​contour data; S133. After being processed by S131 and S132, the hierarchical planning path data corresponding to each sub-grid model after affine transformation is obtained.

10. The multi-material 3D printing device based on a rotating structure according to claim 7, characterized in that: The S2 comprises the following steps: S21. Establishing a one-to-one correspondence between each sub-grid model in the color three-dimensional model and a nozzle unit of a specific printing material, as well as an absolute position relationship corresponding to the working space of each nozzle unit; S22. Process the path information of the current slice layer k of each sub-grid model according to the obtained hierarchical path data after slicing each sub-grid model, where k starts from 1, that is, control each print head unit to print according to the path information until the slice filling paths of all sub-grid models are printed; S23. According to step S22, continue to process the k+1 layer slice path data of each sub-grid model until all slice paths are printed.

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