A 3D printing device capable of directly manufacturing a color three-dimensional part and a printing method thereof

Abstract

The application discloses a 3D printing device capable of directly preparing a color three-dimensional part and a printing method thereof. The device comprises a machine body, a lifting cylinder assembly, a forming cylinder, a forming flat plate, a first moving assembly, a nozzle assembly and a powder laying assembly. The nozzle assembly is internally provided with a plurality of color coloring nozzles and binder nozzles which are independently moved relative to the first moving assembly. The binder nozzles are used for spraying binder to bond the powder, and the color coloring nozzles are used for spraying color coloring medium into the powder. The device further comprises a control unit which is used for analyzing three-dimensional model slice data with color information, controlling the powder laying, binder spraying and color coloring medium spraying processes to be sequentially executed layer by layer, and directly preparing a three-dimensional object with color. The device can realize precise multi-color binder layering spraying, inhibit color bleeding, ensure the forming size precision and color restoration degree, and is suitable for a plurality of substrates such as gypsum, precoated sand, ceramic powder and composite powder, and can directly prepare a color additive manufacturing part.

Description

Technical Field

[0001] This invention relates to the field of binder jetting 3D printing technology, specifically to a 3D printing device and printing method that can directly produce colored three-dimensional parts. Background Technology

[0002] Traditional adhesive spraying equipment only supports single-color adhesive molding, resulting in long post-processing coloring cycles, poor color consistency, uneven surface coloring, and inability to directly print color products. Existing color spraying equipment mostly uses multi-color inks and adhesives for separate spraying, which has drawbacks such as ink mixing and pollution, poor powder layer flatness, interference between adhesive penetration and color diffusion, and difficulty in balancing molding accuracy and color fidelity. At the same time, color spraying is prone to interlayer color bleeding and poor curing compatibility of color adhesives, which significantly reduces the dimensional accuracy and color reproduction of molded parts.

[0003] Therefore, there is an urgent need to develop a set of integrated color binder spraying 3D printing equipment that combines multi-color binder supply, precise powder spreading, layer spraying, in-situ curing, and waste gas and dust recovery, so as to realize one-time molding of powder-based parts with colored textures, logos, and patterns. Summary of the Invention

[0004] The purpose of this invention is to address the problems existing in the prior art by providing a 3D printing device and printing method that can directly produce colored three-dimensional parts.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A 3D printing device capable of directly producing colored stereoscopic parts includes a body, a printing platform located in the upper middle part of the body, a printing window on the printing platform, a lifting cylinder assembly located below the printing platform, a forming cylinder corresponding to the printing window on the lifting cylinder assembly, and a liftable forming plate inside the forming cylinder; a first moving assembly located at the upper interior of the body, and an independently movable nozzle assembly and powder spreading assembly located below the first moving assembly; the powder spreading assembly reciprocates from one side of the body towards the printing window, spreading a uniform powder layer layer by layer in the forming cylinder; the nozzle... The assembly reciprocates from the other side of the machine body toward the printing window. The printhead assembly contains multiple color-coloring printheads and adhesive printheads that move independently of the first moving component. The adhesive printheads are used to spray adhesive to bond the powder, and the color-coloring printheads are used to spray color-coloring media into the powder. It also includes a control unit connected to the lifting cylinder assembly, the first moving component, the printhead assembly, and the powder spreading assembly. This control unit is used to analyze the 3D model slice data with color information and control the powder spreading, adhesive spraying, and color-coloring media spraying processes to be executed layer by layer, directly producing a colored 3D object.

[0006] Furthermore, the first moving component includes a transverse linear moving module mounted on the top wall of the machine body, the transverse linear moving module being provided with a slide connected to the nozzle assembly and the powder spreading assembly.

[0007] Furthermore, the powder spreading assembly includes a mounting frame connected to the first moving component, the mounting frame is provided with a powder storage hopper, and a powder leveling shaft and a powder spreading roller are provided at the lower outlet of the powder storage hopper; a powder dropping mechanism is also provided on the side of the machine body near the powder spreading assembly, and a spiral powder feeding shaft is provided in the powder dropping mechanism for uniformly conveying powder to the powder storage hopper.

[0008] Furthermore, the lifting cylinder assembly includes a Z-axis lifting component disposed above the bottom of the machine body, the output end of the Z-axis lifting component is provided with a bearing plate, and the single-layer lifting accuracy of the Z-axis lifting component is ≤0.02mm; the forming cylinder includes a cylinder body, the forming plate is disposed inside the cylinder body, and the bearing plate is located below the forming plate; a sealing dustproof strip is provided between the periphery of the forming plate and the inner periphery of the cylinder body, and a powder groove is provided on the upper edge of the outer periphery of the cylinder body.

[0009] Furthermore, the lifting cylinder assembly is provided with a support partition connected to the machine body, the support partition is provided with support vertical plates on both sides, the support vertical plates are provided with multiple support rollers on their sides, the lower edge of the cylinder body is provided with a support edge, the support edge is located on the support rollers, and the front side of the cylinder body is also provided with a handle.

[0010] Furthermore, the outer side of the forming cylinder is also provided with a powder collection channel, which is connected to a powder collection bucket located on one side of the lifting cylinder assembly.

[0011] Furthermore, the printhead assembly includes a printhead box mounting bracket connected to the first movable component. The printhead box mounting bracket is connected to a printhead box with adjustable angle and vertical position. The printhead box is provided with a mounting partition, on which multiple ink cartridges are provided, and an ink pump connected to the ink cartridges and the color printing printhead. A spraying window is provided below the printhead box, and a movable printhead mounting frame is provided at the spraying window. The color printing printhead and the adhesive printhead are provided in the printhead mounting frame, and accordion covers covering the spraying window are provided on both sides of the printhead mounting frame.

[0012] Furthermore, the nozzle mounting frame is also provided with a plate support frame, the plate support frame is provided with a nozzle plate, the inner wall of the nozzle box is provided with a distribution card, and the control unit is sequentially connected to the distribution card, the nozzle plate and the color printing nozzle.

[0013] Furthermore, the nozzle box mounting bracket includes a support beam, with support side plates on both sides and a support top plate on top. The upper end of the support side plates is connected to the side of the support top plate via an angle adjustment block. The inner wall of the nozzle box is provided with a first connecting protrusion, and the inner side of the support side plate is provided with a second connecting block. The second connecting block passes through the guide groove of the side wall of the nozzle box and is connected to the first connecting protrusion via an adjusting bolt.

[0014] A printing method for a 3D printing device capable of directly producing colored stereoscopic parts includes the following steps: The lifting cylinder assembly, the powder spreading assembly, the nozzle assembly, the first moving component, and the control unit have all been debugged and adjusted. The lifting cylinder assembly drives the forming plate to the initial position. Import a 3D model containing color information, and slice it to obtain the geometric contour data and color data of each layer of the 3D model; The powder spreading assembly is controlled to move onto the molding plate to perform a powder spreading operation, resulting in a powder layer, and then the powder spreading assembly returns to its original position. The nozzle assembly is controlled to move onto the molding plate. Based on the geometric contour data, the adhesive nozzle sprays adhesive onto the powder layer to bond the powder and form a solid layer. At the same time, based on the color data, the coloring nozzle sprays a coloring medium at the corresponding position of the powder layer. The molding plate is controlled to descend by one layer thickness, and the actions of cyclically spreading powder, spraying binder, and spraying colored coloring medium are carried out to obtain a colored three-dimensional green body by layering. After color 3D printing is completed, the molding cylinder is removed and transported to the drying and cleaning stations for curing and powder cleaning.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. The 3D printing equipment, through the arrangement of the lifting cylinder assembly, the nozzle assembly, the powder spreading assembly, and the control unit, can achieve precise layered spraying of multi-color binders, suppress color bleeding, and ensure the accuracy of molding dimensions and color reproduction; it is equipped with closed-loop powder recovery and in-situ drying and curing, and is compatible with various substrates such as gypsum, coated sand, ceramic powder, and composite powder, directly preparing colored additive parts; 2. The 3D printing equipment can spray the coloring medium only on the solid areas of the part, without spraying the blank powder areas, saving consumables. Integrating the coloring nozzle and the binder nozzle into the same nozzle assembly allows the binder spraying printing process to complete the coloring simultaneously, directly obtaining a colored three-dimensional blank after molding, without the need for subsequent spraying and coloring; moreover, The adhesive and coloring medium pipelines are isolated from each other to avoid pigment contamination of the adhesive and reduce the risk of printhead clogging. This direct color printing method results in fast coloring, good color consistency, and uniform surface coloring, balancing molding accuracy and color fidelity. 3. The lifting cylinder assembly can independently control the molding platen to lift and lower layer by layer for printing. The molding cylinder, along with its internal molding platform, can be independently extracted from the machine body for transport to the drying and curing station and powder cleaning station without the need to separately transfer uncured preforms, thus avoiding damage to the uncured three-dimensional preforms or causing dimensional deviations. 4. The lifting cylinder assembly, the printhead assembly, the powder spreading assembly, and the control unit adopt a modular design, all of which can be independently disassembled and maintained, facilitating upgrades and expansion of spot color channels. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the external structure of a 3D printing device that can directly produce colored stereoscopic parts according to the present invention; Figure 2 This is a schematic diagram of the internal structure of a 3D printing device that can directly produce colored three-dimensional parts according to the present invention; Figure 3 This is a three-dimensional structural diagram of the lifting cylinder assembly and the forming cylinder of the present invention; Figure 4 This is a front structural diagram of the lifting cylinder assembly and the forming cylinder of the present invention; Figure 5 for Figure 4 Schematic diagram of section AA; Figure 6 This is a three-dimensional structural schematic diagram of the nozzle box assembly of the present invention; Figure 7 This is a schematic diagram of the internal structure of the nozzle box assembly of the present invention. Figure 1 ; Figure 8 This is a schematic diagram of the nozzle box assembly and its internal structure according to the present invention. Figure 2 ; In the diagram: 1. Machine body; 2. Printing window; 3. Lifting cylinder assembly; 301. Z-axis lifting component; 302. Bearing plate; 4. Forming cylinder; 401. Cylinder body; 402. Forming plate; 403. Toner tank; 404. Support edge; 405. Handle; 5. First moving component; 6. Printhead assembly; 601. Printhead box mounting bracket; 602. Printhead box; 7. Toner spreading assembly; 8. Toner collection channel; 9. Toner collection bucket; 10. Support partition; 11. Support vertical plate; 12. Support roller; 13. Upper limit plate; 14. Guide limit strip; 15. Small support 16. Rotary motor; 17. Front limit baffle; 18. Mounting partition; 19. Ink cartridge; 20. Ink pump; 21. Printhead mounting frame; 22. Color printing head; 23. Adhesive printhead; 24. Bellows cover; 25. Enclosure frame; 26. Slide rail; 27. Screw slider module; 28. Plate support frame; 29. ​​Printhead plate; 30. Distribution card; 31. Support beam; 32. Support side plate; 33. Support top plate; 34. Angle adjustment block; 35. First connecting protrusion; 36. Second connecting block; 37. Adjusting bolt; 38. Silencer. Detailed Implementation

[0017] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] In the description of this invention, it should be noted that the terms "middle," "upper," "lower," "left," "right," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0019] Example 1: A 3D printing device capable of directly producing colored stereoscopic parts, combined with... Figures 1-8As shown, the device includes a body 1, a printing platform in the upper middle part of the body 1, a printing window 2 on the printing platform, a lifting cylinder assembly 3 below the printing platform, a forming cylinder 4 corresponding to the printing window 2 on the lifting cylinder assembly 3, and a lifting forming plate 402 inside the forming cylinder 4; a first moving component 5 is located at the upper part of the interior of the body 1, and an independently movable nozzle assembly 6 and a powder spreading assembly 7 are located below the first moving component 5; the powder spreading assembly 7 reciprocates from one side of the body towards the printing window, spreading a uniform powder layer layer by layer in the forming cylinder 4; the nozzle assembly 6 moves from the printing window towards the printing window. The machine body reciprocates towards the printing window on the other side. The nozzle assembly 6 is equipped with multiple color-coloring nozzles 22 and adhesive nozzles 23 that can move independently of the first moving component. The adhesive nozzles 23 are used to spray adhesive to bond the powder, and the color-coloring nozzles 22 are used to spray color-coloring medium into the powder. It also includes a control unit connected to the lifting cylinder assembly, the first moving component, the nozzle assembly and the powder spreading assembly, which is used to analyze the three-dimensional model slice data with color information, control the powder spreading, adhesive spraying and color-coloring medium spraying processes to be executed layer by layer, and directly prepare a colored three-dimensional object.

[0020] This 3D printing equipment, through the configuration of the lifting cylinder assembly 3, the nozzle assembly 6, the powder spreading assembly 7, and the control unit, can achieve precise layered spraying of multi-color binders, suppress color bleeding, and ensure the accuracy of molding dimensions and color reproduction; it is compatible with various substrates such as gypsum, coated sand, ceramic powder, and composite powder, and can directly prepare colored additive parts.

[0021] This 3D printing equipment can spray coloring medium only onto the solid areas of the part, omitting the blank powder areas, thus saving consumables. In other words, it does not apply coloring and binder spraying to all the powder layers, but only to the shape to be formed. Integrating the coloring nozzle 22 and the binder nozzle 23 into the same nozzle assembly 6 allows coloring to be completed simultaneously during the binder spraying and printing process, resulting in a directly colored three-dimensional blank without the need for post-printing. Integrating multiple nozzles within the same area also effectively reduces space occupation and the number of components required for moving and controlling various types of nozzles, making the entire nozzle assembly more compact. Furthermore, the binder and coloring medium pipelines are isolated from each other, preventing pigment contamination of the binder and reducing the risk of nozzle clogging. This direct color printing method offers fast coloring, good color consistency, and uniform surface coloring, balancing forming accuracy and color fidelity.

[0022] Another advantage of coloring only the three-dimensional forming area is that the uncured and uncolored powder outside the green body can be recycled during the subsequent cleaning process, avoiding the problem of the difficulty in reusing the coloring powder.

[0023] By placing the nozzle assembly 6 and the powder spreading assembly 7 below the same first moving component 5, they can share a set of sliding rails for the moving system, reducing the number of moving parts. At the same time, they can move independently, performing sequential translational and reciprocating motions. The lifting cylinder assembly 3 can independently control the forming plate 402 to lift and lower layer by layer, so that it can print and form layer by layer. The forming cylinder 4, together with the forming plate 402 inside it, can be independently pulled out from the machine body 1, so that it can be transported as a whole to the drying and curing station and the powder cleaning station. There is no need to separately transfer the uncured green blank, so as to avoid damaging the uncured three-dimensional green blank or causing dimensional deviations.

[0024] The lifting cylinder assembly, the nozzle assembly, the powder spreading assembly, and the control unit are all modularly designed and can be independently disassembled and maintained, facilitating upgrades and expansion of the spot color channel.

[0025] In this embodiment, the machine body 1 includes a welded annealed frame and a marble crossbeam module seat, etc., to ensure the rigidity of high-speed reciprocating scanning, reduce the vibration of high-speed printing, and reduce color jet misalignment; the whole machine shell is sealed, and a humidity sensor is installed inside the machine to monitor the humidity inside the machine in real time. If necessary, a dehumidification device can also be installed to control the internal humidity and prevent the color binder from evaporating prematurely and the powder from absorbing moisture and clumping.

[0026] Furthermore, the first moving component 5 includes a transverse linear moving module installed on the inner top wall of the body 1. The transverse linear moving module is provided with a slide block connected to the nozzle assembly and the powder spreading assembly. The two slide blocks can be moved independently by a motor or the like, allowing the nozzle assembly and the powder spreading assembly to operate independently.

[0027] Furthermore, the powder spreading assembly 7 includes a mounting frame connected to the first moving component. The mounting frame has a powder storage hopper, and a powder leveling shaft and a powder spreading roller are located at the lower outlet of the powder storage hopper. A powder dropping mechanism is also provided on the side of the machine body near the powder spreading assembly. The powder dropping mechanism has a spiral powder feeding shaft for conveying powder to the powder storage hopper. The powder dropping mechanism is fixed and does not move with the powder spreading assembly. The powder spreading assembly is positioned at the location of the powder dropping mechanism so that when powder needs to be replenished after the powder spreading action is completed, the powder dropping mechanism can convey powder into the powder spreading assembly.

[0028] By feeding powder in a quantitative manner, the powder spreading assembly moves reciprocally in the horizontal direction to spread a uniform powder layer on the forming platform; the powder spreading speed and powder feeding amount can be adjusted according to the actual situation.

[0029] Furthermore, the lifting cylinder assembly 3 includes a Z-axis lifting component 301 (Z-axis refers to the vertical direction) disposed above the bottom of the machine body. The output end of the Z-axis lifting component 301 is provided with a bearing plate 302. The single-layer lifting accuracy of the Z-axis lifting component 301 is ≤0.02mm. The forming cylinder 4 includes a cylinder body 401. The forming plate 402 is disposed inside the cylinder body 401. The bearing plate 302 is located below the forming plate 402. A sealing dustproof strip is provided between the periphery of the forming plate 402 and the inner periphery of the cylinder body 401. A powder trough 403 is provided on the upper edge of the outer periphery of the cylinder body 401.

[0030] In some embodiments, the Z-axis lifting assembly 301 uses a high-precision ball screw and a high-precision linear guide to achieve precise layered descent in the Z-axis direction. After each layer of powder is applied, the forming platform descends by one layer thickness. The forming cylinder 4 can be a square cylinder body. The cylinder body 401 is positioned above the support partition 10 and remains stationary. The forming plate 402 inside can move up and down under the drive of the Z-axis lifting assembly. Sealing dustproof strips around the cylinder body prevent colored adhesive droplets from seeping into the cylinder body gaps and contaminating the transmission components.

[0031] The powder trough 403 is designed to collect powder that falls to the outside during the powder spreading process, preventing the powder from scattering throughout the internal space. Moreover, this powder can be cleaned up together with the molding cylinder during subsequent cleaning.

[0032] Furthermore, combined Figures 3-5 As shown, the lifting cylinder assembly 3 is provided with a support partition 10 connected to the machine body 1. The support partition 10 is provided with support vertical plates 11 on both sides. The support vertical plates 11 are provided with multiple support rollers 12 on their sides. The lower edge of the cylinder body 401 is provided with a support edge 404, which is located on the support rollers 12. The front side of the cylinder body 401 is also provided with a handle 405.

[0033] The cylinder body 401 of the forming cylinder 4 can remain stationary during the printing process and can be moved as a whole after printing is completed. The cylinder body 401 is supported on the support rollers 12 by the support edge 404. With the help of the handle 405, it is easy to pull the forming cylinder 4 out horizontally from the machine body. At the same time, the weight of the forming cylinder 4 can be pressed on these support rollers 12 instead of falling on the Z-axis lifting assembly below, reducing the force on it and facilitating its stable operation and control of lifting accuracy.

[0034] In some embodiments, the upper surface of the support vertical plate 11 is higher than the height of the highest point of the outer periphery of the support roller 12, so that the support edge 404 of the cylinder 401 is restricted between the pair of support vertical plates 11, preventing the cylinder 401 from moving left or right or swaying; an upper limit plate 13 is also provided above the support vertical plate 11, and the upper limit plate 13 is provided with a guide limit strip 14 facing the support edge 404, which can vertically limit the cylinder to prevent the cylinder 401 from moving upward, but does not affect the forward and backward movement of the cylinder 401, that is, the cylinder 401 can be slidably pulled out when it needs to be pulled out. A small bracket 15 is also provided on the support partition 10. A rotary motor 16 is provided on the small bracket 15. The output end of the rotary motor 16 is connected to a front limit baffle 17. When the cylinder 401 is in the printing working state, the front limit baffle 17 rotates to the vertical position, which can form a limit in front of the cylinder 401. When it is necessary to remove the forming cylinder 4, the front limit baffle 17 can rotate to other positions, such as downward, to release the limit on the cylinder 401 so that it can be smoothly removed.

[0035] Furthermore, the outer side of the molding cylinder 4 is also provided with a powder collection channel 8, which is connected to a powder collection bucket 9 located on one side of the lifting cylinder assembly. Excess powder scraped off the molding platform can be collected through the powder collection channel 8 and the powder collection bucket 9, allowing for centralized recycling and reuse.

[0036] Furthermore, combined Figures 6-8 As shown, the printhead assembly 6 includes a printhead box mounting bracket 601 connected to the first moving component 5. The printhead box mounting bracket 601 is connected to a printhead box 602 with adjustable angle and vertical position. The printhead box 602 is provided with a mounting partition 18. The mounting partition 18 is provided with a plurality of ink cartridges 19 and an ink pump 20 connected to the ink cartridges 19 and the color printing printhead. A spraying window is provided below the printhead box 602. A movable printhead mounting frame 21 is provided at the spraying window. The color printing printhead 22 and the adhesive printhead 23 are provided in the printhead mounting frame 21. The adhesive printhead 23 is connected to the adhesive pump. Accordion covers 24 covering the spraying window are also provided on both sides of the printhead mounting frame 21.

[0037] The printhead box 602, through the installation partition 18, can divide its internal space into upper and lower spaces. The upper space can be used to arrange ink cartridges, ink pumps and other feeding components, while the lower space can be used to arrange control components and various printheads, thereby reducing mutual interference between the upper and lower components.

[0038] Integrating the color-coloring nozzle 22 and the adhesive nozzle 23 into the same nozzle mounting frame 21 allows for synchronous longitudinal movement of the color-coloring nozzle and the adhesive nozzle, enabling simultaneous adhesive spraying and curing as well as color coloring. The nozzle mounting frame 21 is mounted at the spraying window via a second moving component, allowing it to move independently of the nozzle box 602 at the nozzle window for precise spraying and coloring. Furthermore, the nozzle box as a whole can move laterally along with the nozzle box mounting bracket, enabling the nozzle mounting frame 21 to achieve two levels of lateral movement: a large-scale movement following the overall movement and a small-scale movement independent of the overall movement.

[0039] Specifically, the inner bottom of the nozzle box 602 is provided with a frame 25 around the spraying window. The second moving component includes a pair of slide rails 26 disposed within the frame 25. The nozzle mounting frame 21 is mounted on the slide rails 26 by a slider. A lead screw slider module 27 is provided on the outer side of the frame 25 and connected to a servo motor. The lead screw slider module 27 is connected to the nozzle mounting frame 21 through a connector, which can drive the nozzle mounting frame 21 to reciprocate along the slide rails 26. The bellows cover 24 is also provided between the nozzle mounting frame 21 and the frame in the direction of movement, which can play a dynamic sealing and dynamic blocking role.

[0040] In some embodiments, a silencer 38 is provided below the mounting partition 18. The silencer can reduce noise and prevent large noise from the top from being transmitted to the bottom, thereby reducing the adverse effects of sound wave fluctuations on the powder.

[0041] Furthermore, the nozzle mounting frame 21 is also provided with a plate support frame 28, the plate support frame 28 is provided with a nozzle plate 29, the inner wall of the nozzle box 602 is provided with a distribution card 30, and the control unit is connected to the distribution card, the nozzle plate and the color coloring nozzle in sequence.

[0042] Through the layer-by-layer control of the distribution card and the nozzle plate, the adhesive nozzle and the color ink nozzle can simultaneously spray curing agent and color ink during the printing process of free reciprocating motion in the lateral direction, so that each layer of the model has color, and finally a full-color 3D object is formed.

[0043] Furthermore, the nozzle box mounting bracket 601 includes a support beam 31, with support side plates 32 on both sides of the support beam 31 and a support top plate 33 on the top. The upper end of the support side plate 32 is connected to the side of the support top plate 33 through an angle adjustment block 34. The inner wall of the nozzle box 602 is provided with a first connecting protrusion 35, and the inner side of the support side plate 32 is provided with a second connecting block 36. The second connecting block 36 passes through the guide groove of the side wall of the nozzle box 602 and is connected to the first connecting protrusion 35 through an adjusting bolt 37.

[0044] The above-described structure allows for fine-tuning of the nozzle box 602's vertical and angular positions within a certain range. Tightening the adjusting bolt allows adjustment of the relative height between the first connecting protrusion 35 and the second connecting block 36, thus achieving fine-tuning and simultaneously connecting the nozzle box. The bracket top plate 33 has an oval hole, providing adjustable space during connection. Tightening the angle adjusting block allows adjustment of the relative positions of the bracket side plate and the bracket top plate.

[0045] Example 2: A printing method for a 3D printing device that can directly produce colored stereoscopic parts includes the following steps: The lifting cylinder assembly, the powder spreading assembly, the nozzle assembly, the first moving component, and the control unit have all been debugged and adjusted. The lifting cylinder assembly drives the forming plate to the initial position. Import a 3D model containing color information, and slice it to obtain the geometric contour data and color data of each layer of the 3D model; The powder spreading assembly is controlled to move onto the molding plate to perform a powder spreading operation, resulting in a powder layer, and then the powder spreading assembly returns to its original position. The nozzle assembly is controlled to move onto the molding plate. Based on the geometric contour data, the adhesive nozzle sprays adhesive onto the powder layer to bond the powder and form a solid layer. At the same time, based on the color data, the coloring nozzle sprays a coloring medium at the corresponding position of the powder layer. The molding plate is controlled to descend by one layer thickness, and the actions of cyclically spreading powder, spraying binder, and spraying colored coloring medium are carried out to obtain a colored three-dimensional green body by layering. After color 3D printing is completed, the molding cylinder is removed and transported to the drying and cleaning stations for curing and powder cleaning.

[0046] This printing method simultaneously sprays binder and coloring medium onto the powder layer layer by layer, and the sprayed area is the geometric outline of the entity to be formed. This makes the printed three-dimensional blank inherently colored, rather than a surface-painted color, and it does not color the powder in the unformed areas. It balances forming accuracy and color fidelity, and can also reduce ink waste and powder loss. The powder used for coloring can be easily processed and reused, further reducing production costs.

[0047] After printing, the molding cylinder can be transferred as a whole to the drying station for curing. Although the molding cylinder is moved, the three-dimensional blank remains cured in situ and does not move relative to the powder layer inside the molding cylinder. This is beneficial to its molding accuracy and quality, eliminating the need for separate transfer of the printed blank. After curing, cleaning can be performed to remove the residual dry powder from the molding cylinder and to clean the powder from the surface of the cured blank, resulting in a complete cured and molded colored three-dimensional component.

[0048] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A 3D printing device capable of directly producing colored stereoscopic parts, comprising a body, characterized in that, The upper middle part of the machine body is provided with a printing platform, and the printing platform has a printing window. Below the printing platform is a lifting cylinder assembly, and the lifting cylinder assembly has a forming cylinder corresponding to the printing window. The forming cylinder has a liftable forming plate inside. Inside the upper part of the machine body is a first moving component, and below the first moving component are an independently movable nozzle assembly and a powder spreading assembly. The powder spreading assembly reciprocates from one side of the machine body towards the printing window, spreading a uniform powder layer layer by layer in the forming cylinder. The nozzle assembly moves from the other side of the machine body towards the printing window. The printing window reciprocates. The printhead assembly contains multiple color-coloring printheads and adhesive printheads that can move independently of the first moving component. The adhesive printheads are used to spray adhesive to bond the powder, and the color-coloring printheads are used to spray color-coloring media into the powder. It also includes a control unit connected to the lifting cylinder assembly, the first moving component, the printhead assembly, and the powder spreading assembly. This control unit is used to analyze the 3D model slice data with color information and control the powder spreading, adhesive spraying, and color-coloring media spraying processes to be executed layer by layer, directly producing a colored 3D object.

2. The 3D printing equipment for directly producing colored stereoscopic parts according to claim 1, characterized in that, The first moving component includes a transverse linear moving module installed on the top wall of the machine body, the transverse linear moving module being provided with a slide connected to the nozzle assembly and the powder spreading assembly.

3. The 3D printing equipment for directly producing colored stereoscopic parts according to claim 1, characterized in that, The powder spreading assembly includes a mounting frame connected to the first moving component. The mounting frame is provided with a powder storage hopper. A powder leveling shaft and a powder spreading roller are provided at the lower outlet of the powder storage hopper. A powder dropping mechanism is also provided on the side of the machine body near the powder spreading assembly. The powder dropping mechanism is provided with a spiral powder feeding shaft for conveying powder to the powder storage hopper.

4. The 3D printing equipment for directly producing colored stereoscopic parts according to claim 1, characterized in that, The lifting cylinder assembly includes a Z-axis lifting component disposed above the bottom of the machine body. The output end of the Z-axis lifting component is provided with a bearing plate. The single-layer lifting accuracy of the Z-axis lifting component is ≤0.02mm. The forming cylinder includes a cylinder body. The forming plate is disposed inside the cylinder body. The bearing plate is located below the forming plate. A sealing dustproof strip is provided between the periphery of the forming plate and the inner periphery of the cylinder body. A powder groove is provided on the upper edge of the outer periphery of the cylinder body.

5. The 3D printing equipment for directly producing colored stereoscopic parts according to claim 4, characterized in that, The lifting cylinder assembly is provided with a support partition plate connected to the machine body. Supporting vertical plates are provided on both sides of the support partition plate. Multiple supporting rollers are provided on the side of the supporting vertical plates. The lower edge of the cylinder body is provided with a supporting edge, which is located on the supporting rollers. A handle is also provided on the front side of the cylinder body.

6. The 3D printing equipment for directly producing colored stereoscopic parts according to claim 1, characterized in that, The outer side of the forming cylinder is also provided with a powder collection channel, which is connected to a powder collection bucket located on one side of the lifting cylinder assembly.

7. The 3D printing equipment for directly producing colored stereoscopic parts according to claim 1, characterized in that, The printhead assembly includes a printhead box mounting bracket connected to the first movable component. The printhead box mounting bracket is connected to a printhead box. The printhead box has a mounting partition inside, and multiple ink cartridges are mounted on the mounting partition. An ink pump is connected to the ink cartridges and the color printing printhead. A spraying window is provided below the printhead box. A movable printhead mounting frame is provided at the spraying window. The color printing printhead and the adhesive printhead are located inside the printhead mounting frame. Accordion covers covering the spraying window are also provided on both sides of the printhead mounting frame.

8. The 3D printing equipment for directly producing colored stereoscopic parts according to claim 7, characterized in that, The nozzle mounting frame is also provided with a plate support frame, on which a nozzle plate is provided. The inner wall of the nozzle box is provided with a distribution card. The control unit is connected in sequence to the distribution card, the nozzle plate and the color printing nozzle.

9. The 3D printing equipment for directly producing colored stereoscopic parts according to claim 7, characterized in that, The nozzle box mounting bracket includes a support beam, with support side plates on both sides and a support top plate on top. The upper end of the support side plates is connected to the side of the support top plate via an angle adjustment block. The inner wall of the nozzle box is provided with a first connecting protrusion, and the inner side of the support side plate is provided with a second connecting block. The second connecting block passes through a guide groove in the side wall of the nozzle box and is connected to the first connecting protrusion via an adjusting bolt.

10. The printing method of the 3D printing equipment capable of directly producing colored stereoscopic parts according to any one of claims 1 to 9, characterized in that, Includes the following steps: The lifting cylinder assembly, the powder spreading assembly, the nozzle assembly, the first moving component, and the control unit have all been debugged and adjusted. The lifting cylinder assembly drives the forming plate to the initial position. Import a 3D model containing color information, and slice it to obtain the geometric contour data and color data of each layer of the 3D model; The powder spreading assembly is controlled to move onto the molding plate to perform a powder spreading operation, resulting in a powder layer, and then the powder spreading assembly returns to its original position. The nozzle assembly is controlled to move onto the molding plate. Based on the geometric contour data, the adhesive nozzle sprays adhesive onto the powder layer to bond the powder and form a solid layer. At the same time, based on the color data, the coloring nozzle sprays a coloring medium at the corresponding position of the powder layer. The molding plate is controlled to descend by one layer thickness, and the actions of cyclically spreading powder, spraying binder, and spraying colored coloring medium are carried out to obtain a colored three-dimensional green body by layering. After color 3D printing is completed, the molding cylinder is removed and transported to the drying and cleaning stations for curing and powder cleaning.

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