Powder spreading device for 3D printing

Abstract

The application discloses a powder spreading device for 3D printing and relates to the technical field of 3D printing, aiming to solve the technical problem of insufficient stirring of two powders with large quality difference, and comprises a frame, a powder spreading mechanism, a stirring assembly, an opening and closing assembly and a material cavity assembly. The first and second one-way rotating structures are reversely arranged, so that the stirring rod can be expanded or contracted as required. When expanded, the stirring rod is attached to the inner wall of the spherical stirring tank, and the heavy powder at the bottom is fully taken out, thereby solving the problem of dead corners of the traditional cylindrical stirring tank and avoiding the deposition of heavy powder and the insufficient mixing. When contracted, the stirring rod is in a spiral shape, and can realize efficient stirring and diffusion of the powder with small quality difference. In addition, the blocking piece in the opening and closing assembly avoids the problem of incomplete stirring cavity caused by the traditional pipeline assembly valve, and prevents the heavy powder from gathering in the cylindrical channel. The uniformity of powder mixing is greatly improved, and the quality of 3D printing products is significantly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of 3D printing, more particularly, to a powder laying device for 3D printing. BACKGROUND

[0002] In the powder laying device for 3D printing, double-channel conveying refers to a technology of conveying powder materials of different types or different states by using two independent channels; this conveying mode has significant advantages in improving printing efficiency, enriching printing material combinations, etc.: realizing multi-material printing, optimizing powder mixing and distribution, and improving printing efficiency;

[0003] When processing powders with large quality differences in double-channel conveying, the existing stirring tank has many deficiencies; common stirring tank types include cylindrical and spherical, etc.; the cylindrical stirring tank has dead corners at the bottom edge, when the powder with heavy quality is deposited in these dead corners, the stirring device is difficult to reach, and the powder with heavy quality cannot be fully mixed with other powders, thereby affecting the overall uniformity of the powder; while using the spherical stirring tank with arc-shaped inner wall of the stirring cavity, no dead corners are avoided, but if the stirring mode is improper, the powder with heavy quality will still be deposited at the bottom of the stirring cavity, resulting in uneven distribution of the two powders during subsequent powder laying, thereby affecting the quality of the printed product;

[0004] On the spherical stirring tank, if a valve such as a solenoid valve is assembled through a pipeline, a cylindrical channel will be left between the pipeline and the spherical stirring tank, which will make the stirring cavity in the spherical stirring tank no longer a complete spherical cavity; this incomplete cavity structure will cause the powder with heavy quality to easily gather inside the cylindrical channel when stirring two powders with large quality differences, further affecting the stirring effect of the two powders, and ultimately adversely affecting the quality of product powder laying and printing, therefore, we propose a powder laying device for 3D printing. SUMMARY

[0005] The present application aims to provide a powder laying device for 3D printing to solve the technical problem of insufficient stirring of two powders with large quality differences.

[0006] To solve the above technical problems, the present application provides the following technical solutions: a powder laying device for 3D printing, comprising a frame, a printing platform arranged inside the frame, a laser generator located above the printing platform, a powder laying mechanism arranged above the printing platform, a stirring assembly and an opening and closing assembly, and a material cavity assembly arranged below the printing platform, wherein the stirring assembly comprises a spherical stirring tank, the spherical stirring tank is located above the printing platform, a transmission rod is rotationally connected inside the spherical stirring tank, a plurality of stirring rods are hingedly connected in an annular array on the left end plate of the transmission rod, a transmission cylinder is commonly hingedly connected to the other ends of the plurality of stirring rods, a first one-way rotation structure is arranged between the transmission cylinder and the stirring rods, a second one-way rotation structure is arranged between the transmission cylinder and the spherical stirring tank, and the first and second one-way rotation structures are arranged in opposite directions; the opening and closing assembly comprises a blocking piece arranged inside the output end of the spherical stirring tank.

[0007] The plurality of stirring rods can be expanded or contracted through the first and second one-way rotation structures, when expanded, each stirring rod is attached to the inner wall of the spherical stirring tank, causing the powder with heavier mass deposited at the bottom of the spherical stirring tank to be removed and fully mixed with another powder; when contracted, the plurality of stirring rods are in a spiral shape, capable of stirring two powders with small mass difference, and causing the powder to accumulate on the inner wall of the spherical stirring cavity and then diffuse to the surroundings.

[0008] When the blocking piece moves upward inside the output end of the spherical stirring tank, the blocking piece forms a seal with the inner wall of the spherical stirring tank, and when the blocking piece moves downward, it forms a flow channel inside the output end of the spherical stirring tank, the first and second one-way rotation structures are arranged in opposite directions, so that the stirring rods can be expanded or contracted as needed; when expanded, the stirring rods are attached to the inner wall of the spherical stirring tank, fully removing the heavy powder at the bottom, solving the problem of dead corners in traditional cylindrical stirring tanks and avoiding the deposition of heavy powder that cannot be fully mixed; when contracted, the stirring rods are in a spiral shape, capable of efficiently stirring and diffusing powders with small mass difference; in addition, the blocking piece in the opening and closing assembly avoids the problem of incomplete stirring cavity caused by traditional pipeline assembly valves, preventing heavy powder from accumulating in the cylindrical channel; these innovative designs greatly improve the uniformity of powder mixing, ensuring uniform distribution when laying powder subsequently, thereby significantly improving the quality of 3D printed products.

[0009] Preferably, a storage module is arranged on the outside of the frame, and the laser generator is arranged on the top of the frame through a translation mechanism.

[0010] Two guide rails are fixedly connected to the inner walls of the two sides of the frame in a symmetrical structure, and a pneumatic sliding block is slidingly connected to the surface of each guide rail.

[0011] Preferably, the powder laying mechanism comprises two sliding boxes, the two sliding boxes are fixedly connected between two pneumatic sliders respectively, a scraper module is slidingly connected between the two sliding boxes, a top cylinder is fixedly connected to the inner wall of the bottom of each sliding box, the output end of the top cylinder is in transmission connection with the scraper module, a support is fixedly connected between the two sliding boxes, and the bottom of the scraper module penetrates through the support.

[0012] Preferably, the stirring assembly comprises a fixed plate, the fixed plate is fixedly connected to the inner wall on one side of the support, and the spherical stirring tank is fixedly connected to the top of the fixed plate and communicates with the storage module through a pipeline.

[0013] Preferably, a first motor is fixedly connected to one side of the top of the fixed plate, a first pawl wheel is arranged on the surface of the output shaft of the first motor, the output shaft of the first motor is in transmission connection with a transmission rod, a groove is formed in one side of each stirring rod, a first ratchet wheel is arranged on the inner wall of the transmission cylinder, and the first pawl wheel is in meshing connection with the first ratchet wheel.

[0014] Preferably, the first pawl wheel and the first ratchet wheel are in meshing connection or non-meshing sliding connection, which is a first one-way rotation structure.

[0015] Preferably, a second pawl wheel is fixedly connected to the side of the transmission cylinder close to the first motor, a fixed disc is fixedly connected to the right end of the spherical stirring tank, a plurality of waist-shaped holes are annularly arranged on one side of the fixed disc, a plurality of fixed blocks are movably connected to one side of the fixed disc through insertion rods, the insertion rods are inserted into the waist-shaped holes on the fixed blocks, and a plurality of movable discs are movably connected to the side away from the fixed disc of the fixed blocks, a plurality of inclined holes are formed in one side of the movable discs, and the other ends of the insertion rods are inserted into the inclined holes on the movable discs.

[0016] Preferably, the plurality of fixed blocks can be gathered or expanded, when the plurality of fixed blocks are gathered, the plurality of fixed blocks are in meshing connection with the second pawl wheel, which is a second one-way rotation structure, and when the plurality of fixed blocks are expanded, the plurality of fixed blocks are out of contact with the second pawl wheel, which provides convenience for the expansion of the stirring rods.

[0017] Preferably, an electric push rod is fixedly connected in the hole on the fixed plate, and the output shaft of the electric push rod is hingedly connected to the surface of the movable disc.

[0018] Preferably, the opening and closing assembly comprises a connecting pipe, the connecting pipe is fixedly connected to the top of the scraper module, the connecting pipe is movably sleeved in the inner wall of the output end of the spherical stirring tank, a blocking piece is fixedly connected to the top of the connecting pipe, and a flow passage is arranged between the blocking piece and the connecting pipe.

[0019] Preferably, the material cavity assembly comprises a transmission frame fixedly connected to the inner wall of the bottom of the frame, the inner wall of the bottom of the transmission frame is fixedly connected with two servo motors in a symmetrical structure, the output end of each of the two servo motors is fixedly connected with a first gear, and the top of the transmission frame is rotatably connected with two second gears.

[0020] Preferably, the first gear and the second gear are connected through a transmission belt, the inner wall of each second gear is threadedly connected with a lead screw, the two lead screws are inserted into the holes in the transmission frame, the end surface of the lead screw is square, the top of the two lead screws is fixedly connected with a bearing plate, and the bearing plate is slidably sleeved on the inside of the powder laying cavity on the printing platform.

[0021] Compared with the prior art, the present application has the following advantages:

[0022] 1. The first and second one-way rotation structures are arranged in reverse, so that the stirring rod can be expanded or tightened as needed. When expanded, the stirring rod adheres to the inner wall of the spherical stirring tank, fully bringing out the heavy powder at the bottom, solving the problem of dead angles in traditional cylindrical stirring tanks and avoiding the deposition of heavy powder that cannot be fully mixed. When tightened, the stirring rod is in a spiral shape, which can efficiently stir and diffuse powder with small quality differences. In addition, the design of the blocking piece in the opening and closing assembly avoids the problem of incomplete stirring cavity caused by traditional pipeline assembly valves, preventing heavy powder from accumulating in the cylindrical channel. These innovative designs greatly improve the uniformity of powder mixing, ensure the uniform distribution of subsequent powder laying, and significantly improve the quality of 3D printed products.

[0023] 2. The present application innovatively designs a double one-way rotation structure and a deformable stirring rod for different quality difference powders transported by the double channel. When processing powder with small quality differences, the stirring rod rotates in a spiral shape, realizing the cyclic mixing of powder accumulation and diffusion. When processing powder with large quality differences, the stirring rod expands to adhere to the tank wall, using the groove to bring out the heavy powder at the bottom, and orderly mixing through axial rotation, effectively solving the problem of insufficient mixing in traditional stirring tanks and improving the uniformity of powder.

[0024] 3. The present application uses a unique opening and closing assembly to replace the traditional pipeline assembly valve, avoiding the formation of a cylindrical channel in the spherical stirring tank, ensuring that the stirring cavity is a complete sphere, eliminating powder accumulation dead angles, ensuring that two powders with large quality differences are fully stirred, improving stirring effect and printed product quality, and preventing valve structure blockage to improve service life. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 The present application is a three-dimensional structure schematic diagram.

[0026] Figure 2 The present application is an overall structure cross-sectional schematic diagram.

[0027] Figure 3 The three-dimensional structure schematic diagram of the powder spreading mechanism of the present application.

[0028] Figure 4 The three-dimensional exploded structure schematic diagram of the powder spreading mechanism of the present application.

[0029] Figure 5 The three-dimensional exploded structure schematic diagram of the stirring assembly of the present application.

[0030] Figure 6 The three-dimensional structure sectional schematic diagram of the stirring assembly of the present application.

[0031] Figure 7 The three-dimensional exploded structure schematic diagram of the stirring assembly of the present application.

[0032] Figure 8 The three-dimensional structure schematic diagram of the opening and closing assembly of the present application. Figure 7 The enlarged structure schematic diagram of A in the present application.

[0033] Figure 9 The three-dimensional exploded structure schematic diagram of the opening and closing assembly of the present application.

[0034] Figure 10 The three-dimensional structure sectional schematic diagram of the stirring rod in the retracted use state of the present application.

[0035] Figure 11 The three-dimensional structure sectional schematic diagram of the stirring rod in the expanded use state of the present application.

[0036] Figure 12 The actual schematic diagram of the powder spreading device for 3D printing of the present application.

[0037] Label explanation in the figure: 1, frame; 11, printing platform; 12, laser generator; 13, storage module; 2, translation mechanism; 3, guide rail; 31, pneumatic sliding block;

[0038] 4, powder spreading mechanism; 41, sliding box; 42, scraper module; 43, top cylinder; 44, support;

[0039] 5, stirring assembly; 51, fixed plate; 52, spherical stirring tank; 53, first motor; 531, first pawl wheel; 54, transmission rod; 55, stirring rod; 551, groove; 56, transmission cylinder; 561, first ratchet gear; 562, second pawl wheel; 57, fixed disc; 571, waist-shaped hole; 58, fixed block; 59, movable disc; 591, inclined hole; 510, electric push rod;

[0040] 6, opening and closing assembly; 61, connecting pipe; 62, blocking piece;

[0041] 7. Material chamber assembly; 71. Transmission frame; 72. Servo motor; 73. First gear; 74. Second gear; 75. Transmission belt; 76. Lead screw; 77. Bearing plate. Detailed Implementation

[0042] Example 1, such as Figures 1-4 As shown, the present invention relates to a powder spreading device for 3D printing, comprising a frame 1, a printing platform 11 arranged inside the frame 1, a laser generator 12, and a storage module 13 arranged outside the frame 1. The laser generator 12 is arranged on the top of the frame 1 via a translation mechanism 2.

[0043] The inner walls on both sides of the frame 1 are symmetrically connected to two guide rails 3. Each guide rail 3 has a pneumatic slider 31 slidably connected to its surface. Between the two pneumatic sliders 31, a powder spreading mechanism 4, a stirring assembly 5, an opening and closing assembly 6, and a material chamber assembly 7 are arranged.

[0044] The powder spreading mechanism 4 includes two sliding boxes 41, which are fixedly connected between two pneumatic sliders 31. A scraper module 42 is slidably connected between the two sliding boxes 41. A top cylinder 43 is fixedly connected to the bottom inner wall of each sliding box 41, and the output end of the top cylinder 43 is connected to the scraper module 42 in a transmission manner. A bracket 44 is fixedly connected between the two sliding boxes 41, and the bottom of the scraper module 42 passes through the bracket 44.

[0045] It is worth noting that the laser generator 12 precisely scans each layer of powder with a high-energy laser beam, causing the metal powder to completely melt and solidify, forming a dense metal structure.

[0046] It is worth noting that the translation mechanism 2 in this invention is a motor-driven movable lead screw sliding platform. The motor-driven lead screw sliding platform is a conventional technology and will not be described in detail here. Using the lead screw sliding platform to realize the translational movement of the laser generator 12 not only ensures precise movement but also helps to improve printing efficiency.

[0047] It is worth noting that the scraper module 42 in this invention has the function of scraping and spreading powder, and the powder flows evenly into the powder spreading cavity after being stirred. This module is a conventional technology and will not be described in detail here.

[0048] Specifically, the scraper module 42 moves up or down via the top cylinder 43. When it moves down, the output end of the scraper module 42 is flush with the edge of the powder spreading chamber. When it moves up, the output end of the scraper module 42 is above the edge of the powder spreading chamber.

[0049] like Figures 4-11As shown, the stirring assembly 5 comprises a fixed plate 51 fixedly connected to the inner wall of one side of the support 44, a spherical stirring tank 52 fixedly connected to the top of the fixed plate 51, and the spherical stirring tank 52 is in communication with the storage module 13 through a pipeline, a first motor 53 fixedly connected to the top of the fixed plate 51, a first pawl wheel 531 arranged on the surface of the output shaft of the first motor 53, a transmission rod 54 fixedly connected to the output shaft of the first motor 53, a plurality of stirring rods 55 hingedly connected to the left end plate of the transmission rod 54 in an annular array, a recess 551 formed in one side of each stirring rod 55, a transmission cylinder 56 commonly hingedly connected to the other end of the plurality of stirring rods 55, a first ratchet gear 561 arranged on the inner wall of the transmission cylinder 56, and the first pawl wheel 531 is in meshing connection with the first ratchet gear 561, a second pawl wheel 562 fixedly connected to the side of the transmission cylinder 56 close to the first motor 53, a fixed disc 57 fixedly connected to the right end of the spherical stirring tank 52, a plurality of waist-shaped holes 571 formed in the side of the fixed disc 57 in an annular array, a plurality of fixed blocks 58 movably connected to the side of the fixed disc 57 through insertion rods, and the insertion rods are inserted into the inside of the waist-shaped holes 571, a movable disc 59 movably connected to the side away from the fixed disc 57 of the plurality of fixed blocks 58, a plurality of inclined holes 591 formed in the side of the movable disc 59, and the other ends of the insertion rods are inserted into the inside of the inclined holes 591, and an electric push rod 510 fixedly connected to the hole in the fixed plate 51, and the output shaft of the electric push rod 510 is hingedly connected to the surface of the movable disc 59.

[0050] Specifically, the first pawl wheel 531 and the first ratchet gear 561 are a first one-way rotation structure, the second pawl wheel 562 and the gathered fixed blocks 58 are a second one-way rotation structure, and the directions of the meshing connection and the non-meshing sliding connection of the first and second one-way rotation structures are opposite.

[0051] Specifically, the plurality of stirring rods 55 are expanded or tightened, when expanded, each stirring rod 55 is attached to the inner wall of the spherical stirring tank 52, so that the powder with heavier quality deposited at the bottom of the spherical stirring tank 52 is removed and fully mixed with another powder, when tightened, the plurality of stirring rods 55 are in a spiral shape, which can stir two powders with small quality difference, and the powder can be accumulated on the inner wall of the spherical stirring tank 52 through the spiral stirring rods 55 and then diffused to the surrounding.

[0052] The present application is aimed at different quality difference powders conveyed by double ducts, and a double one-way rotation structure and a deformable stirring rod 55 are innovatively designed; when processing powders with small quality difference, the stirring rod 55 rotates in a spiral shape to realize the cyclic mixing of powder accumulation and diffusion; when processing powders with large quality difference, the stirring rod 55 is expanded to attach to the tank wall, the recess 551 is used to take out the heavy powder at the bottom, and the powder is orderly mixed through axial rotation, which effectively solves the problem that the traditional stirring tank cannot fully mix, and improves the uniformity of the powder.

[0053] Example 2, as Figure 9As shown, the opening and closing assembly 6 comprises a connecting pipe 61 fixedly connected to the top of the scraper module 42 and movably sleeved on the inner wall of the output end of the spherical stirring tank 52, the top of the connecting pipe 61 is fixedly connected with a baffle 62, the baffle 62 is sealingly matched with the inner wall of the spherical stirring tank 52, and a flow passage is arranged between the baffle 62 and the connecting pipe 61.

[0054] Specifically, when the scraper module 42 moves upward, the baffle 62 forms a seal with the inner wall of the spherical stirring tank 52, and when it moves downward, the baffle 62 moves to the inside of the output end of the spherical stirring tank 52, and a flow passage is left between them.

[0055] Compared with other valves, such as electromagnetic valves and the like, the valve is used on the spherical stirring tank 52, and a cylindrical channel is left between the pipe and the spherical stirring tank 52, so that the stirring cavity in the spherical stirring tank 52 is an incomplete spherical cavity, which causes the heavy powder to gather in the cylindrical channel when stirring two powders with large mass difference, which not only affects the stirring of the two powders with large mass difference, but also affects the quality of the product powder printing.

[0056] The present application adopts a unique opening and closing assembly 6 to replace the traditional pipeline assembled valve, avoids the formation of a cylindrical channel in the spherical stirring tank 52, ensures that the stirring cavity is a complete sphere, eliminates the powder gathering dead angle, ensures that the two powders with large mass difference are fully stirred, improves the stirring effect and the quality of the printed product, and at the same time, prevents the valve structure from being blocked, prolongs the service life.

[0057] As shown in the figure, Figure 2 As shown, the material cavity assembly 7 comprises a transmission frame 71 fixedly connected to the inner wall of the bottom of the frame 1, the inner wall of the bottom of the transmission frame 71 is fixedly connected with two servo motors 72 in a symmetrical structure, the output ends of the two servo motors 72 are fixedly connected with first gears 73, the top of the transmission frame 71 is rotatably connected with two second gears 74, the first gears 73 and the second gears 74 are connected through transmission belts 75, the inner wall of each second gear 74 is threadedly connected with a lead screw 76, and the two lead screws 76 are inserted into the holes of the transmission frame 71, the end surface of the lead screw 76 is square, the top of the two lead screws 76 is fixedly connected with a bearing plate 77, and the bearing plate 77 is slidingly sleeved in the powder spreading cavity inside the printing platform 11.

[0058] It is worth noting that by arranging a square on the end surface of the lead screw 76, the lead screw 76 can move upward or downward during the rotation of the second gear 74, and cannot rotate.

[0059] Working principle: the embodiment provides a powder laying device for 3D printing. When the powder with small mass difference is conveyed through double ducts, the powder flows into the inside of the spherical stirring tank 52 from the storage module 13 through the pipeline. At this time, the external control system drives the electric push rod 510 to rotate the movable disc 59, the fixed block 58 is expanded through the inserted rod, and is disconnected from the second pawl wheel 562, and the first one-way structure is engaged and connected. Then the external circuit system drives the first motor 53 to work, the first motor 53 drives the transmission rod 54 to rotate, the first one-way structure is in non-engagement sliding connection, so that the left end of the stirring rod 55 rotates first, causing the whole stirring rod 55 to form a spiral shape through torque and rotate, and the two powders with small mass difference are stirred. The powder located in the middle of the spherical stirring tank 52 is accumulated on one side through the spiral stirring rod 55, and is diffused to the surrounding through the spherical stirring cavity, forming a circulating and reciprocating mixing effect.

[0060] When the powder with large mass difference is conveyed through double ducts: the powder flows into the inside of the spherical stirring tank 52 from the storage module 13 through the pipeline. At this time, the external control system drives the electric push rod 510 to rotate the movable disc 59, the fixed block 58 is expanded through the inserted rod, forms a ratchet, and is engaged and connected with the second pawl wheel 562 to form a second one-way rotation structure. Then the first motor 53 drives the transmission rod 54 to rotate, so that the first one-way rotation structure is in engagement connection, and the second one-way rotation structure is in non-engagement sliding connection, causing the plurality of stirring rods 55 to rotate synchronously. The powder with large mass difference is gathered on the inner wall of the bottom of the spherical stirring tank 52, and the powder at the bottom is taken out through the groove 551 on the stirring rod 55, and is orderly flowed out in the axial upward rotation of the stirring rod 55.

[0061] Powder laying and printing: after stirring is completed, the external control system drives the pneumatic sliding block 31 to drive the scraper module 42 to move. When the scraper module 42 moves to the edge of the powder laying cavity, the cylinder 43 drives the scraper module 42 to move downward. At this time, the blocking piece 62 moves downward in the inside of the output end of the spherical stirring tank 52, flows out of the duct, and the powder flows into the inside of the scraper module 42 through the duct, and is uniformly distributed in each part through the scraper module 42, and then flows out from the output end. In the movement of the scraper module 42, the powder is filled and leveled, and then the translation mechanism 2 drives the laser generator 12 to move, adjusts the position of the laser generator 12, and prints the powder below. At the same time, in the layer-by-layer printing, the servo motor 72 works, the transmission belt 75 drives the second gear 74 to rotate, causing the rod 76 connected with the second gear 74 through threads to drive the bearing plate 77 to move downward, and providing enough space for printing and powder laying.

[0062] The embodiments of the present application disclose the preferred embodiments, but are not limited to the same. Those skilled in the art can easily understand the spirit of the present application according to the above embodiments, and make different inferences and changes, as long as they do not deviate from the spirit of the present application, and are within the protection scope of the present application.

Claims

1. A powder spreading device for 3D printing, comprising a frame, a printing platform arranged inside the frame, a laser generator located above the printing platform, a powder spreading mechanism arranged above the printing platform, a stirring assembly and an opening and closing assembly, a material cavity assembly arranged below the printing platform, characterized in that, The stirring assembly comprises a spherical stirring tank located above a printing platform, a transmission rod is rotationally connected inside the spherical stirring tank, a plurality of stirring rods are hingedly connected in an annular array on a left end plate of the transmission rod, a transmission cylinder is commonly hingedly connected to the other ends of the stirring rods, a first one-way rotation structure is arranged between the transmission cylinder and the stirring rods, a second one-way rotation structure is arranged between the transmission cylinder and the spherical stirring tank, and the first and second one-way rotation structures are arranged in opposite directions; the opening and closing assembly comprises a blocking piece arranged inside an output end of the spherical stirring tank; The stirring assembly comprises a fixed plate fixedly connected to an inner wall of one side of the support, and the spherical stirring tank is fixedly connected to the top of the fixed plate and is in communication with the storage module through a pipeline; A first motor is fixedly connected to one side of the top of the fixed plate, a first pawl wheel is arranged on the surface of the output shaft of the first motor, the output shaft of the first motor is in transmission connection with the transmission rod, a groove is formed in one side of each stirring rod, a first ratchet wheel is arranged on the inner wall of the transmission cylinder, and the first pawl wheel is in meshing connection with the first ratchet wheel; The first one-way rotation structure is meshing connection or non-meshing sliding connection between the first pawl wheel and the first ratchet wheel; A second pawl wheel is fixedly connected to the side of the transmission cylinder close to the first motor, a fixed disc is fixedly connected to the right end of the spherical stirring tank, a plurality of waist-shaped holes are formed in an annular array on one side of the fixed disc, a plurality of fixed blocks are movably connected to one side of the fixed disc through insertion rods, the insertion rods are inserted into the waist-shaped holes on the fixed blocks, a movable disc is movably connected to the side away from the fixed disc of the plurality of fixed blocks, a plurality of inclined holes are formed in one side of the movable disc, and the other ends of the insertion rods on the movable disc are inserted into the inclined holes; The plurality of fixed blocks can be gathered or expanded, when the plurality of fixed blocks are gathered, the second one-way rotation structure is meshing connection between the plurality of fixed blocks and the second pawl wheel, and when the plurality of fixed blocks are expanded, the second pawl wheel is disconnected from the plurality of fixed blocks, thereby providing convenience for expansion of the stirring rods; An electric push rod is fixedly connected in the hole on the fixed plate, and the output shaft of the electric push rod is hingedly connected to the surface of the movable disc; The plurality of stirring rods can be expanded or tightened through the first and second one-way rotation structures, when the plurality of stirring rods are expanded, each stirring rod is attached to the inner wall of the spherical stirring tank, so that the powder with a heavier mass deposited at the bottom of the spherical stirring tank is removed and fully mixed with another powder; when the plurality of stirring rods are tightened, the plurality of stirring rods are in a spiral shape, so that two powders with a small mass difference can be stirred, and the powder is accumulated on the inner wall of the spherical stirring cavity and then diffused to the surroundings through the stirring rods; When the blocking piece moves upward inside the output end of the spherical stirring tank, the blocking piece forms a seal with the inner wall of the spherical stirring tank, and when the blocking piece moves downward, the blocking piece forms a flow channel inside the output end of the spherical stirring tank.

2. The powder spreading device for 3D printing according to claim 1, wherein A storage module is arranged on the outside of the frame, and the laser generator is arranged on the top of the frame through a translation mechanism; Two guide rails are fixedly connected to the inner walls of the two sides of the frame in a symmetrical structure, and a pneumatic sliding block is slidably connected to the surface of each guide rail.

3. The powder spreading device for 3D printing according to claim 2, wherein The powder laying mechanism comprises two sliding boxes, the two sliding boxes are fixedly connected between two pneumatic sliders respectively, a scraper module is slidingly connected between the two sliding boxes, a top cylinder is fixedly connected to the inner wall of the bottom of each sliding box, the output end of the top cylinder is in transmission connection with the scraper module, a support is fixedly connected between the two sliding boxes, and the bottom of the scraper module penetrates through the support.

4. The powder spreading device for 3D printing according to claim 3, wherein The opening and closing assembly comprises a connecting pipe, the connecting pipe is fixedly connected to the top of the scraper module, the connecting pipe is movably sleeved to the inner wall of the output end of the spherical stirring tank, a blocking piece is fixedly connected to the top of the connecting pipe, and a flow passage is arranged between the blocking piece and the connecting pipe.

5. The powder spreading device for 3D printing according to claim 4, wherein The material cavity assembly comprises a transmission frame, the transmission frame is fixedly connected to the inner wall of the bottom of the frame, two servo motors are fixedly connected to the inner wall of the bottom of the transmission frame in a symmetrical structure, a first gear is fixedly connected to the output end of each servo motor, and two second gears are rotatably connected to the top of the transmission frame.

6. The powder spreading device for 3D printing according to claim 5, wherein The first gear and the second gear are connected through a transmission belt, a lead screw is threadedly connected to the inner wall of each second gear, and the two lead screws are inserted into the holes of the transmission frame, the end surface of the lead screw is square, a bearing plate is fixedly connected to the top of the two lead screws, and the bearing plate is slidingly sleeved to the inside of the powder laying cavity of the printing platform.

Images