Multi-raw-material mixing equipment for 3D printing

Abstract

The invention belongs to the technical field of 3D printing, and discloses 3D printing multi-raw-material mixing equipment which comprises a shell, a cylinder is fixed in the shell, a through groove is formed in the bottom of the cylinder, a round pipe is fixed to the side wall of the cylinder, the other end of the round pipe is connected with a material conveying pipe, an air pump is arranged at the other end of the material conveying pipe, and a plurality of powder bins are arranged above the material conveying pipe. A quantitative blanking module is arranged between the powder bin and the conveying pipe; a powder distribution module is arranged in the cylinder, a discharging roller is arranged below the cylinder, a baffle is arranged on one side of the discharging roller, one end of the baffle makes contact with the outer wall of the discharging roller, the other end of the baffle is fixed to the shell, and the powder distribution module can evenly scatter materials conveyed into the cylinder from a material conveying pipe through an air pump between the discharging roller and the baffle through a through groove. A discharging groove is formed in the bottom of the shell below the discharging roller, and the discharging roller can scatter materials from the discharging groove when rotating. According to the invention, the problem of limitation of a premixing mode in an SLM printing process on material selection and gradient material printing is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of 3D printing, and particularly relates to a 3D printing multi-material mixing device. Background Art

[0002] Metal 3D printing technology can not only greatly reduce the processing time and cost of components, but also meet complex customization requirements and lightweight design. It has now been widely applied in fields such as aerospace and medical devices. Among them, the SLM (Selective Laser Melting) process is the most widely used due to its advantages of high precision and good surface quality; When the SLM process prints components, the powder in the powder cylinder is spread on the substrate by a scraper. During the powder spreading process, the mixed powder accumulates in front of the scraper and moves under the push of the scraper. The mixed powder may have a reduced fluidity due to a widened particle size distribution and different shapes, affecting the powder spreading uniformity and increasing the pores or warping of the printed parts; and the piled mixed powder in front of the scraper is prone to segregation during the pushing process, that is, the powder with a large density gradually accumulates at the bottom of the whole pile of powder, resulting in only the powder with a small density remaining in the second half of the powder spreading, and the powder spreading effect needs to be improved; although in order to reduce the influence of the above defects, there is a requirement to select metal powders with small density differences and uniform particle size distributions when choosing metals, but it also synchronously limits the selection range of metals when mixing powders; and its powder mixing method is external premixing, and there is only one powder cylinder and a fixed ratio of mixed metal powder in the printing chamber, and gradient materials cannot be printed; the above signs indicate that the "premixing" mixing method has great limitations in the diversity of material selection and the need for gradient material printing. Summary of the Invention

[0003] The purpose of the present invention is to propose a 3D printing multi-material mixing device to solve the limitations of the premixing method in material selection and gradient material printing in the SLM printing process.

[0004] In order to achieve the above purpose, the present invention adopts the following technical solutions: A 3D printing multi-material mixing device, comprising a housing that can slide left and right within a printing device. A horizontal cylinder is fixed inside the housing. A through groove is opened along the generatrix at the bottom of the cylinder. A circular pipe is fixed on the side wall of the cylinder, and the circular pipe communicates with the inner cavity of the cylinder. The other end of the circular pipe extends out of the housing and is connected to a feeding pipe. An air pump is provided at the other end of the feeding pipe. Above the feeding pipe between the circular pipe and the air pump, there are multiple powder bins. The bottom of each powder bin communicates with the side wall of the feeding pipe. A quantitative feeding module is provided between the powder bin and the feeding pipe. A powder spreading module is provided inside the cylinder. Below the cylinder, there is a discharging roller. The axis of the discharging roller is parallel to the axis of the cylinder. A baffle is provided on one side of the discharging roller. One end of the baffle contacts the outer wall of the discharging roller, and the other end is fixed to the housing. The powder spreading module can evenly spread the material sent from the feeding pipe into the cylinder by the air pump through the through groove between the discharging roller and the baffle. An discharging groove is opened at the bottom of the housing below the discharging roller. When the discharging roller rotates, it can spread the material from the discharging groove.

[0005] As a further description of the above technical solution: The powder bin is located outside the printing bin of the printer. The end of the feeding pipe at the bottom of the powder bin away from the air pump extends into the printing bin. The air pump is located at the upper part inside the printing bin cavity. During use, the air pump blows inert gas inside the printing bin into the feeding pipe, and then blows the material falling into the feeding pipe from the powder bin into the cylinder. An electric push rod is fixed on the housing, and the other end of the electric push rod is fixed to the inner wall of the printing bin. The electric push rod drives the housing to slide left and right. The inner diameter of the circular pipe is equal to the outer diameter of the feeding pipe. When the housing moves, the feeding pipe can be inserted into the circular pipe, thereby realizing the detachable connection between the circular pipe and the feeding pipe.

[0006] As a further description of the above technical solution: The quantitative feeding module includes a circular roller. The circular roller is located at the bottom of the powder bin, and the side wall and two end faces of the circular roller are attached to the inner wall of the powder bin. Grooves are provided on the side wall of the circular roller. A stepping motor is provided outside the powder bin. The rotating shaft of the stepping motor extends into the powder bin and is connected to the circular roller. By controlling the rotation angle of the stepping motor and the size of the grooves, quantitative feeding from the powder bin into the feeding pipe is achieved.

[0007] As a further description of the above technical solution: The powder distribution module comprises an inner cylinder, which is coaxially arranged with the cylinder, one end of the inner cylinder is set as an opening, and a disc is fixed at the other end, a ring is fixed on the outer side of the disc through a connecting block, a circular groove is opened on the side wall of the inner cylinder, and the diameter of the circular groove is equal to the inner diameter of the circular tube, a spiral blade is arranged in the inner cylinder, and the spiral blade is fixed to the inner wall of the inner cylinder, a filter plate is arranged at one end of the opening of the inner cylinder, and a plurality of material-diverting plates are arranged between the filter plate and the inner cylinder, and each material-diverting plate is parallel to the radial direction of the inner cylinder; two parallel vertical plates are fixed below the through groove, wherein the height of the vertical plate on one side is greater than the height of the vertical plate on the other side and a flat plate is fixed at the lower end, and the two vertical plates and the flat plate are connected. An L-shaped slider is provided in the middle, a round rod is fixed on the upper end of the slider, the upper end of the round rod is located between the disc and the ring, and the side of the slider facing the filter plate is an inclined surface; when in use, the air pump blows the material in the feed pipe into the inner cylinder through the round tube, the gas is discharged from the filter plate, the material gathers in the inner cylinder cavity, and then the inner cylinder moves axially in the cylinder and rotates at the same time, the spiral blades and the material-pickling plate mix the material and push the material onto the flat plate, and then the inclined surface on the slider scrapes the material off the flat plate, because the distance between the two vertical plates and the distance between the flat plate and the inner wall of the cylinder remain unchanged, the amount of material gathered on the flat plate is equal everywhere in the length direction.

[0008] As a further description of the above technical solution: An arc plate is fixed to one end of the material-dispensing plate close to the outer wall of the cylinder. The arc plate is coaxial with the cylinder, and the central angle corresponding to the arc plate is greater than the central angle corresponding to the through groove, so that the material cannot fall on the flat plate when the powder distribution module is not moved.

[0009] As a further description of the above technical solution: A partition is fixed in the shell, and the cylinder, discharging roller and baffle are all located on one side of the partition. A lead screw is coaxially arranged in the cylinder, and a lead screw nut is arranged at the center of the disc and the filter plate. One end of the lead screw is rotatably connected to the side wall of the shell, and the other end passes through the partition and is connected to a first motor. The first motor is fixed on the inner wall of the shell on the other side of the partition; when the first motor rotates, it drives the lead screw to rotate, and when the lead screw rotates, it can drive the powder distribution module to move axially and rotate through the disc and the filter plate.

[0010] As a further description of the above technical solution: The side wall of the discharge roller is provided with a plurality of diamond-shaped grooves, the rotating shaft of the discharge roller passes through the partition and is connected to the second motor. When the second motor drives the discharge roller to rotate, the material falls into the groove and rotates with the groove to below the baffle and then separates from the shell from the discharge groove.

[0011] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: (1) The present invention draws on the working mode of discharging materials while printing in the laser metal deposition process, changing the original premixing step in the selective laser melting process to online mixing. When in use, the powders to be mixed are filled in different powder bins respectively, and the air pump and powder spreading module complete the mixing of different metal powders while transporting the powders. Moreover, the mixing method combines pneumatic mixing and forced mixing by spiral blades, ensuring the mixing effect, with a compact structure and ingenious design.

[0012] (2) The present invention changes the original action of scraping materials by a scraper to the action of the housing discharging materials downward. The discharging roller in the housing directly spreads the powders that have been mixed twice onto the substrate, completely avoiding the segregation that easily occurs to the mixed powders piled up in front of the scraper during the scraping by the scraper. The uniformity of the mixed powders on the substrate is better, effectively reducing the probability of holes or warping defects appearing on the printed parts and improving the mechanical properties of the printed parts.

[0013] (3) When in use, the present invention can adopt the working mode of online mixing, putting different metal powders into different powder bins, and the air pump and powder spreading module complete the transportation and mixing actions of different metal powders; or it can also adopt the working mode of premixing, putting the premixed metal powders into one of the powder bins, with only one powder bin discharging materials. After the air pump and powder spreading module transport and remix the premixed powders, the discharging roller still completes the spreading action, still being able to avoid the defect of segregation that easily occurs in the powder scraping action by the scraper.

[0014] (4) By adopting the online mixing method, the present invention circumvents the need to consider the density and particle size differences of different metals during premixing, and has a wider selection range of metal types when mixing metals, which is beneficial to exploring the potential and application of the SLM process in the fields of functional gradient materials and in-situ alloying. Brief Description of the Drawings

[0015] Figure 1 It is a schematic diagram when the present invention is in use; Figure 2 It is a three-dimensional view of the present invention; Figure 3 It is a schematic diagram of the internal structure of the housing 1 of the present invention; Figure 4 It is a sectional view of the internal structure of the housing 1 of the present invention; Figure 5 It is an exploded view of the internal structure of the housing 1 of the present invention; Figure 6 It is an assembly schematic diagram of the cylinder 2 and the circular tube 4 of the present invention; Figure 7 It is a structural diagram of the powder spreading module of the present invention; Figure 8 It is a part drawing of the discharging roller 8 of the present invention; Figure 9This is the part drawing of the slider 22 of the present invention; Figure 10 This is the structural schematic diagram of the quantitative blanking module of the present invention.

[0016] Legend: 1. Housing; 2. Cylinder; 3. Through groove; 4. Round tube; 5. Feeding pipe; 6. Air pump; 7. Powder bin; 8. Discharging roller; 9. Baffle; 10. Discharging chute; 11. Round roller; 12. Groove; 13. Inner cylinder; 14. Disk; 15. Ring; 16. Round groove; 17. Spiral blade; 18. Filter plate; 19. Material guiding plate; 20. Vertical plate; 21. Flat plate; 22. Slider; 23. Round rod; 24. Arc plate; 25. Partition; 26. Lead screw; 27. First motor; 28. Sunk groove; 29. Second motor. Detailed implementation manners

[0017] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0018] Please refer to Figures 1-10 , the present invention provides a technical solution for a 3D printing multi-material mixing device: A 3D printing multi-material mixing device includes a housing 1, on which an electric push rod is fixed. The other end of the electric push rod is fixed to the inner wall of the printing bin, and the electric push rod drives the housing 1 to slide left and right; a horizontal cylinder 2 is fixed inside the housing 1. A through groove 3 is opened along the generatrix at the bottom of the cylinder 2. A round tube 4 is fixed on the side wall of the cylinder 2. The round tube 4 communicates with the inner cavity of the cylinder 2. The other end of the round tube 4 extends out of the housing 1 and is connected to a feeding pipe 5. The inner diameter of the round tube 4 is equal to the outer diameter of the feeding pipe 5. When the housing 1 moves, the feeding pipe 5 can be inserted into the round tube 4, thereby realizing the detachable connection between the round tube 4 and the feeding pipe 5; An air pump 6 is provided at the other end of the feeding pipe 5. Above the feeding pipe 5 between the round tube 4 and the air pump 6, a plurality of powder bins 7 are provided. The bottom of each powder bin 7 communicates with the side wall of the feeding pipe 5. The powder bins 7 are located outside the printing bin of the 3D printer. The end of the feeding pipe 5 at the bottom of the powder bin 7 away from the air pump 6 extends into the printing bin. The air pump 6 is located in the upper part of the printing bin cavity. When in use, the air pump 6 blows the inert gas in the printing bin into the feeding pipe 5, and then blows the material falling into the feeding pipe 5 from the powder bin 7 into the cylinder 2; A quantitative blanking module is provided between the powder bin 7 and the feeding pipe 5, and the quantitative blanking module includes a round roller 11, which is located at the bottom of the powder bin 7, and the side wall and two end faces of the round roller 11 are in contact with the inner wall of the powder bin 7, and a groove 12 is provided on the side wall of the round roller 11. A stepper motor is provided on the outer side of the powder bin 7, and the rotating shaft of the stepper motor extends into the powder bin 7 and is connected to the round roller 11. The quantitative blanking of the powder bin 7 into the feeding pipe 5 is achieved by controlling the rotation angle of the stepper motor and the size of the groove 12. A powder distribution module is provided in the cylinder 2, and the powder distribution module includes an inner cylinder 13, which is coaxially arranged with the cylinder 2, one end of the inner cylinder 13 is set to be open, and a disc 14 is fixed at the other end, and a ring 15 is fixed to the outside of the disc 14 through a connecting block, and a circular groove 16 is opened on the side wall of the inner cylinder 13, and the diameter of the circular groove 16 is equal to the inner diameter of the circular tube 4, and a spiral blade 17 is provided in the inner cylinder 13, and the spiral blade 17 is fixed to the inner wall of the inner cylinder 13, and a filter plate 18 is provided at one end of the opening of the inner cylinder 13, and a plurality of material stripping plates 19 are provided between the filter plate 18 and the inner cylinder 13, and each material stripping plate 19 is parallel to the radial direction of the inner cylinder 13; an arc plate 24 is fixed to one end of the material stripping plate 19 close to the outer wall of the cylinder 2, and the arc plate 24 is coaxial with the cylinder 2, and the central angle corresponding to the arc plate 24 is greater than the central angle corresponding to the through groove 3, so that the material of the powder distribution module cannot fall on the flat plate 21 when it is not moved; Two parallel vertical plates 20 are fixed below the through groove 3, wherein the height of the vertical plate 20 on one side is greater than that of the vertical plate 20 on the other side and a flat plate 21 is fixed at the lower end, an L-shaped slider 22 is provided between the two vertical plates 20 and the flat plate 21, a round rod 23 is fixed at the upper end of the slider 22, the upper end of the round rod 23 is located between the disc 14 and the ring 15, and the side of the slider 22 facing the filter plate 18 is an inclined surface; when in use, the air pump 6 blows the material in the feed pipe 5 into the inner cylinder 13 through the circular pipe 4, the gas is discharged from the filter plate 18, the material is gathered in the cavity of the inner cylinder 13, and then the inner cylinder 13 moves axially in the cylinder 2 and rotates at the same time, the spiral blade 17 and the material-pickup plate 19 mix the material and push the material onto the flat plate 21, and then the inclined surface on the slider 22 scrapes the material from the flat plate 21, and since the distance between the two vertical plates 20 and the distance between the flat plate 21 and the inner wall of the cylinder 2 remain unchanged, the amount of material gathered on the flat plate 21 is equal everywhere in the length direction; A discharge roller 8 is provided below the cylinder 2, the axis of the discharge roller 8 is parallel to the axis of the cylinder 2, a baffle 9 is provided on one side of the discharge roller 8, one end of the baffle 9 is in contact with the outer wall of the discharge roller 8, and the other end is fixed to the shell 1, a plurality of diamond-shaped sinking grooves 28 are opened on the side wall of the discharge roller 8, the rotating shaft of the discharge roller 8 passes through the partition 25 and is connected to the second motor 29, when the second motor 29 drives the discharge roller 8 to rotate, the material falls into the sinking groove 28, and after rotating with the sinking groove 28 to the bottom of the baffle 9, it is separated from the shell 1 from the discharge groove 10; The powder distribution module can evenly spread the material sent from the delivery pipe 5 to the cylinder 2 by the air pump 6 through the through groove 3 between the discharge roller 8 and the baffle 9. A discharge groove 10 is opened at the bottom of the shell 1 below the discharge roller 8. The discharge roller 8 can spread the material from the discharge groove 10 when rotating.

[0019] A partition 25 is fixed in the shell 1, and the cylinder 2, the discharge roller 8 and the baffle 9 are all located on one side of the partition 25. A lead screw 26 is coaxially arranged in the cylinder 2, and a lead screw nut is arranged at the center of the disc 14 and the filter plate 18. One end of the lead screw 26 is rotatably connected to the side wall of the shell 1, and the other end passes through the partition 25 and is connected to a first motor 27. The first motor 27 is fixed on the inner wall of the shell 1 on the other side of the partition 25; when the first motor 27 rotates, it drives the lead screw 26 to rotate, and when the lead screw 26 rotates, it can drive the powder distribution module to move axially and rotate through the disc 14 and the filter plate 18.

[0020] Working principle: Before use, the present invention connects the air pump 6, the electric push rod, the stepper motor, the first motor 27 and the second motor 29 to the controller of the printer and turns on the power, and then adds the multiple metals to be mixed into the multiple powder bins 7 respectively; when in use, the printer power is started, and the single rotation angle of each stepper motor is set according to the metal ratio of each mixing, and then the model data of the print part is input into the printer, the print bin is closed, and the print bin is filled with inert gas. After the inert gas is completely filled, the controller starts to print the parts according to the program; The controller first drives the housing 1 to move in the direction of the feeding pipe 5 through the electric push rod, and obtains the position of the housing 1 through the electric push rod. At this time, the powder distribution module is already located in the cylinder 2 near the end of the feeding pipe 5, and the circular groove 16 on the inner cylinder 13 is coaxial with the circular tube 4. When the housing 1 moves to the end of the feeding pipe 5 located in the printing bin and is embedded in the circular tube 4, the electric push rod stops pushing, and the controller completes the first quantitative feeding of the powder bin 7 into the feeding pipe 5 through the stepper motor. The controller then starts the air pump 6, and the air pump 6 blows the inert gas in the printing bin into the feeding pipe 5, thereby spreading various metals. The powder is blown from the feeding pipe 5 to the inner cavity of the inner cylinder 13, and the airflow is discharged from the filter plate 18, and the metal powder is gathered in the cavity of the inner cylinder 13; in this process, the material is initially mixed under the blowing of the airflow while in the feeding pipe 5, and then the airflow carries the powder to the inner cylinder 13. Since the spiral blades 17 are fixed on the inner wall of the inner cylinder 13, the airflow will also flow in a spiral state. The metal powder is thrown on the inner wall of the inner cylinder 13 under the action of centrifugal force and cannot continue to move with the airflow, that is, the metal powder is blocked by the spiral blades 17, and the airflow flows from between the spiral blades 17 and the lead screw 26 to the filter plate 18; Then the controller turns off the air pump 6, starts the electric push rod to drive the shell 1 to separate from the feeding pipe 5. Before the shell 1 moves above the base plate, the controller starts the first motor 27. The first motor 27 drives the powder distribution module to move axially and rotate in the cylinder 2 through the screw 26, the screw nut, the disc 14 and the filter plate 18. When the powder distribution module rotates, the spiral blade 17 will mix the materials in the inner cylinder 13 again and push the materials to the material plate 19. The re-mixed materials pass through between the arc plate 24 and the material plate 19 and fall onto the flat plate 21, and the materials will fill the two vertical plates 2. 0, the upper end of the material is flush with the inner wall of the cylinder 2, and the axial distance moved by the powder distribution module in one rotation is less than the length of the material stripping plate 19, thereby avoiding the periodic fluctuation of the amount of material falling on the flat plate 21 due to the obstruction of the arc plate 24. When the powder distribution module moves axially, the ring 15 pushes the slider 22 to move synchronously through the round rod 23, and the inclined surface on the slider 22 pushes the material on the flat plate 21 from the flat plate 21 to the discharge roller 8. When the powder distribution module moves to the other end of the cylinder 2, the controller reverses the first motor 27, and the powder distribution module returns to the position before the movement. When the shell 1 moves to one side of the substrate, the second motor 29 is started, and the discharge roller 8 starts to rotate. Since the distance between the two vertical plates 20 and the distance from the flat plate 21 to the cylinder 2 are both fixed values, the amount of material between the discharge roller 8 and the baffle plate 9 is equal everywhere in the axial direction, and the size and depth of each rhombus-shaped sinking groove 28 are exactly the same, so when the discharge roller 8 rotates, the sinking groove 28 will evenly spread the material between the discharge roller 8 and the baffle plate 9 on the substrate. When the shell 1 sweeps across the entire substrate, a layer of mixed powder has been evenly sprinkled on the substrate. It should be noted that when the powder distribution module starts to rotate, the powder near the material plate 19 will fall directly on the flat plate 21, and this part of the powder does not participate in the re-mixing of the spiral blade 17. Therefore, in order to avoid insufficient mixing of this part of the powder, the position of the powder distribution module when it starts to drop the material is located on both sides of the substrate, and the powder distribution width of the powder distribution module between the discharge roller 8 and the baffle 9 is greater than the width of the substrate, thereby preventing the powder scattered when the powder distribution module starts to rotate from participating in the printing work. When there is no need for gradient printing, only one powder bin 7 can be used to hold the premixed powder. During use, the airflow blowing action and the spiral blade 17 structure can enhance the mixing of the premixed powder, and the powder is still spread in the form of falling materials, directly avoiding the segregation defects that exist when the scraper scrapes the powder.

[0021] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Within the technical scope disclosed by the present invention, technicians familiar with the technical field can make equivalent replacements or changes based on the technical scheme and inventive concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A 3D printing multi-material mixing device, comprising a housing (1), characterized in that The shell (1) can slide left and right in the printing device. A horizontal cylinder (2) is fixed in the shell (1). A through groove (3) is opened along the generatrix at the bottom of the cylinder (2). A round tube (4) is fixed on the side wall of the cylinder (2). The round tube (4) is connected to the inner cavity of the cylinder (2). The other end of the round tube (4) extends out of the shell (1) and is connected to a feed pipe (5). An air pump (6) is provided at the other end of the feed pipe (5). A plurality of powder bins (7) are provided above the feed pipe (5) between the round tube (4) and the air pump (6). The bottom of each powder bin (7) is connected to the side wall of the feed pipe (5). A quantitative feeding module is provided between the powder bin (7) and the feed pipe (5). A powder distribution module is provided in the cylinder (2), and a discharge roller (8) is provided below the cylinder (2). The axis of the discharge roller (8) is parallel to the axis of the cylinder (2). A baffle (9) is provided on one side of the discharge roller (8). One end of the baffle (9) contacts the outer wall of the discharge roller (8), and the other end is fixed to the shell (1). The powder distribution module can evenly spread the material sent by the air pump (6) from the feed pipe (5) to the cylinder (2) between the discharge roller (8) and the baffle (9) through the through groove (3). A discharge groove (10) is provided at the bottom of the shell (1) below the discharge roller (8). When the discharge roller (8) rotates, the material can be spread out from the discharge groove (10).

2. The device according to claim 1, characterized in that The powder bin (7) is located outside the printing bin of the printer, and the end of the feed pipe (5) at the bottom of the powder bin (7) away from the air pump (6) extends into the printing bin, and the air pump (6) is located in the upper part of the printing bin cavity; an electric push rod is fixed on the shell (1), and the other end of the electric push rod is fixed to the inner wall of the printing bin, and the electric push rod drives the shell (1) to slide left and right; the inner diameter of the round tube (4) is equal to the outer diameter of the feed pipe (5), and the feed pipe (5) can be inserted into the round tube (4) when the shell (1) moves.

3. The device according to claim 1, characterized in that The quantitative blanking module comprises a round roller (11), the round roller (11) is located at the bottom of the powder bin (7), and the side wall and two end faces of the round roller (11) are in contact with the inner wall of the powder bin (7), a groove (12) is provided on the side wall of the round roller (11), and a stepping motor is provided on the outer side of the powder bin (7), and the rotating shaft of the stepping motor extends into the powder bin (7) and is connected to the round roller (11).

4. The device according to claim 1, characterized in that The powder distribution module comprises an inner cylinder (13), the inner cylinder (13) and the cylinder (2) are coaxially arranged, one end of the inner cylinder (13) is set to be open, and a disc (14) is fixed to the other end, a ring (15) is fixed to the outside of the disc (14) via a connecting block, a circular groove (16) is opened on the side wall of the inner cylinder (13), the diameter of the notch of the circular groove (16) is equal to the inner diameter of the circular tube (4), a spiral blade (17) is arranged in the inner cylinder (13), the spiral blade (17) is fixed to the inner wall of the inner cylinder (13), a filter plate (18) is arranged at one end of the opening of the inner cylinder (13), and the filter plate (18) and the inner cylinder (13) are connected. A plurality of material shifting plates (19) are arranged between the two vertical plates (20), each material shifting plate (19) being parallel to the radial direction of the inner cylinder (13); two parallel vertical plates (20) are fixed below the through groove (3), wherein the height of the vertical plate (20) on one side is greater than the height of the vertical plate (20) on the other side and a flat plate (21) is fixed at the lower end; an L-shaped slider (22) is arranged between the two vertical plates (20) and the flat plate (21); a round rod (23) is fixed at the upper end of the slider (22); the upper end of the round rod (23) is located between the disc (14) and the ring (15), and the side of the slider (22) facing the filter plate (18) is an inclined surface.

5. The device according to claim 4, characterized in that An arc plate (24) is fixed to one end of the material-shifting plate (19) close to the outer wall of the cylinder (2). The arc plate (24) is coaxial with the cylinder (2), and the central angle of the arc plate (24) is greater than the central angle of the through groove (3).

6. The device according to claim 4, characterized in that A partition (25) is fixed in the shell (1), the cylinder (2), the discharge roller (8) and the baffle (9) are all located on one side of the partition (25), a lead screw (26) is coaxially arranged in the cylinder (2), and a lead screw nut is arranged at the center of the disc (14) and the filter plate (18), one end of the lead screw (26) is rotatably connected to the side wall of the shell (1), and the other end passes through the partition (25) and is connected to a first motor (27), and the first motor (27) is fixed to the inner wall of the shell (1) on the other side of the partition (25).

7. The device according to claim 6, characterized in that A plurality of diamond-shaped grooves (28) are formed on the side wall of the discharge roller (8), and the rotating shaft of the discharge roller (8) passes through the partition plate (25) and is connected to a second motor (29).

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