Powder cleaning device and powder cleaning method

Abstract

The present application relates to the technical field of metal 3D printing post-processing, and aims to solve the problem of poor powder cleaning effect of the powder cleaning scheme of the known technology, and provides a powder cleaning device and a powder cleaning method. Among them, the powder cleaning device includes a frame, a movable platform and a control component. The movable platform can be movably arranged on the frame, and is used to carry the printed part and drive the printed part to move. The vibration component is installed on the movable platform, and is used to drive the printed part to vibrate through the movable platform. The control component is respectively communicated with the movable platform and the vibration component, and is used to control the vibration parameters of the vibration component based on the position parameters of the movable platform. The beneficial effect of the present application is that the structural arrangement is reasonable and the powder cleaning effect is good.

Description

Technical Field

[0001] The present application relates to the technical field of metal 3D printing post-processing, and in particular to a powder cleaning device and a powder cleaning method. Background Art

[0002] Metal 3D printing, such as Selective Laser Melting (SLM), is a technology that uses the thermal action of a laser beam to rapidly melt and solidify metal powder.

[0003] During the printing process, not all metal powder will be formed into printed parts. The unformed metal powder usually needs to be recycled and screened after printing is completed so that it can be used again.

[0004] Some known powder cleaning devices and methods may not completely clean the powder, leaving metal powder in the internal pores of the printed part, resulting in poor powder cleaning effect. Summary of the Invention

[0005] The present application provides a powder cleaning device and a powder cleaning method to solve the problem that the powder cleaning solutions of the prior art have poor powder cleaning effects.

[0006] In a first aspect, embodiments of the present application provide a powder cleaning device for cleaning powder from printed parts obtained by SLM metal 3D printing. The powder cleaning device includes a frame, a movable platform, and a control component. The movable platform is movably mounted on the frame to support and move the printed part. A vibration component is mounted on the movable platform to vibrate the printed part via the movable platform. The control component is communicatively connected to the movable platform and the vibration component, and is configured to control the vibration parameters of the vibration component based on the position parameters of the movable platform.

[0007] In one possible embodiment, the movable platform includes a flip assembly and a rotation assembly. The rotation assembly includes a bearing surface for supporting and securing a printed workpiece; the rotation assembly is capable of driving the printed workpiece to rotate about a first axis, wherein the first axis is perpendicular to the bearing surface. The rotation assembly is mounted on the flip assembly and, driven by the flip assembly, is capable of rotating about a second axis, wherein the second axis is parallel to the horizontal direction. The movable platform has an initial state, in which the bearing surface is horizontal. Position parameters include a flip angle, which is the angle of rotation of the bearing surface about the second axis during movement from the initial state to the current state. Vibration parameters include a vibration frequency. When the flip angle varies from 0° to 90°, the control assembly is configured to control the vibration assembly to vibrate at a first frequency; when the flip angle varies from 90° to the maximum flip angle, the control assembly is configured to control the vibration assembly to vibrate at a second frequency, wherein the second frequency is greater than the first frequency, and the maximum flip angle is greater than 90° and less than 180°.

[0008] In one possible embodiment, the flip assembly includes a flip drive assembly, a flip frame, and an encoder. The flip drive assembly is connected to the flip frame in a transmission manner and is used to drive the flip frame to rotate around the second axis; the encoder is used to detect the flip angle of the flip frame in real time; the encoder is communicatively connected to the control assembly, and when the flip angle detected by the encoder reaches 90°, the control assembly controls the vibration assembly to switch from the first frequency to the second frequency. A first follower is provided on the flip frame. The powder cleaning device also includes a first detection member, a second detection member, and a third detection member, which are respectively communicatively connected to the control assembly; the first detection member, the second detection member, and the third detection member are distributed circumferentially with the second axis as the center. The first detection member is located at the position where the first follower is located when the movable platform is in the initial state, and is used to calibrate the initial state of the flip frame. The second detection member and the third detection member are respectively located at the position where the first follower is located when the movable platform is at the maximum flip angle in the forward and reverse directions. When the second detection member or the third detection member detects the first follower, the control assembly controls the flip assembly to stop rotating.

[0009] In one possible embodiment, the rotation assembly includes a carrier plate and a rotation drive assembly. The carrier plate is rotatably mounted on a turning frame. The rotation drive assembly is drivingly connected to the carrier plate, configured to drive the carrier plate to rotate about a first axis. The bearing surface is the upper surface of the carrier plate. A fourth detection member is fixedly connected to the turning frame, and a second follower member is fixed to the carrier plate. The fourth detection member is located where the second follower member is located when the carrier plate rotates to zero point, and is used to perform zero point calibration on the carrier plate.

[0010] In one possible embodiment, the frame includes a powder cleaning chamber, which is a sealed chamber. Bearing blocks are mounted on the exterior of two horizontal side walls of the powder cleaning chamber. A tilting shaft is connected to each side of the tilting frame. The two tilting shafts extend through the two side walls and are rotatably supported on the bearing blocks. A tilting drive assembly is drivingly connected to one of the tilting shafts, driving the tilting frame to tilt via the tilting shaft.

[0011] In one possible embodiment, the powder cleaning device further includes a powder collection assembly. The frame further includes a second compartment, a third compartment, and a fourth compartment. The second compartment is located horizontally to one side of the powder cleaning compartment and houses the tilting drive assembly. The third compartment is located directly below the powder cleaning compartment and houses the powder collection assembly. The powder collection assembly is connected to the bottom wall of the powder cleaning compartment and collects powder removed from the compartment. The fourth compartment is located below the second compartment and houses the control assembly.

[0012] In one possible embodiment, the bottom wall of the powder cleaning chamber is funnel-shaped, and a powder dropout port is provided at the bottom end of the bottom wall. The powder collecting assembly includes a powder inlet pipe, a cover plate, two powder collecting funnels, a diverter and a powder outlet pipe. The two powder collecting funnels are arranged in sequence in the horizontal direction, and the cover plate covers the two powder collecting funnels. The powder inlet pipe connects the powder dropout port and the powder inlet port provided on the cover plate. The diverter is in an inverted V-shape, and the upper end of the diverter corresponds to the powder inlet port, and the two sides correspond to the two powder collecting funnels, which are used to divert the powder passing through the powder inlet port to the two powder collecting funnels. The bottom ends of the two powder collecting funnels are respectively connected to the powder outlet pipes, which are used to discharge the powder in the powder collecting funnels.

[0013] In a second aspect, an embodiment of the present application provides a powder cleaning method, which is based on the aforementioned powder cleaning device, and the powder cleaning method includes:

[0014] The flip assembly flips the printed workpiece around the second axis at a set speed, flipping the printed workpiece from 0° to 90°. At the same time, the rotating assembly drives the printed workpiece to rotate around the first axis, and the vibration assembly is controlled to vibrate at a first frequency.

[0015] Then, the printed piece is flipped from 90° to a maximum flip angle, which is greater than 90°. At the same time, the rotating component drives the printed piece to rotate around the first axis, and the vibration component is controlled to vibrate at a second frequency.

[0016] In a possible embodiment, the powder cleaning method further includes: maintaining the printed part at a maximum flip angle, causing the rotating component to drive the printed part to rotate around the first axis, and causing the vibration component to operate at a third frequency for a set time; the third frequency is greater than the second frequency.

[0017] In one possible embodiment, the printed part is a printed part with a plurality of micro-channels, which is made of stainless steel powder by an SLM type 3D printing device;

[0018] The first frequency is 30-36VPM, the second frequency is 42-43VPM, and the third frequency is greater than 45VPM;

[0019] The vibration assembly operates at a first frequency, capable of causing loose metal powder particles in the micro-channel to flow out of the micro-channel;

[0020] The vibration component operates at a second frequency, which can cause sticky powder agglomerates attached to the hole surface of the micro-channel to fall off the printed part and flow out of the micro-channel.

[0021] In summary, the powder cleaning device and method of this embodiment have better powder cleaning effect and can well cope with the powder cleaning of printed parts with micro-channels.

[0022] Furthermore, in this embodiment, the rotary drive assembly of the powder cleaning device is located outside the powder cleaning chamber. This prevents metal powder from entering the rotary drive assembly during cleaning and affecting its function. Both the rotary drive assembly and the powder collection assembly are located outside the powder cleaning chamber, freeing up space within the chamber. This allows the chamber to be fully utilized for accommodating printed parts to be cleaned. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 This is a simplified structural diagram of a printed part according to an embodiment of the present application.

[0025] Figure 2 This is a three-dimensional diagram of the powder cleaning device according to an embodiment of the present application.

[0026] Figure 3 for Figure 2 A three-dimensional diagram of the partial structure of the powder cleaning device.

[0027] Figure 4 for Figure 3 sectional view of .

[0028] Figure 5 A perspective view of the top door and top door drive assembly.

[0029] Figure 6 A three-dimensional diagram of the compression assembly.

[0030] Figure 7 Schematic diagram of the structure of the movable platform and printed parts.

[0031] Figure 8 for Figure 7 Exploded diagram.

[0032] Figure 9 for Figure 8 A partial enlarged view of .

[0033] Figure 10 for Figure 4 A partial enlarged view of .

[0034] Figure 11 This is a three-dimensional diagram of the powder cleaning component.

[0035] Figure 12 for Figure 11 Cross-sectional view of the powder cleaning component.

[0036] Figure 13 This is a schematic diagram of the powder cleaning process status when cleaning the printed part of this application.

[0037] Figure 14 This is a schematic diagram of another powder cleaning process state when cleaning the printed part of this application.

[0038] Figure 15 The figure is a schematic diagram of a toner cleaning process state when a printed part is toner-cleaned in a known solution.

[0039] Figure 16 for Figure 15 A schematic diagram of another powder cleaning process state when a printed part is cleaned of powder in a known solution.

[0040] Figure 17 This is a flow chart of a powder cleaning method according to another embodiment of the present application.

[0041] Explanation of the main component symbols: 100-powder cleaning device; 10-frame; 11-movable platform; 12-vibration assembly; 13-control assembly; 14-powder collecting assembly; 15-powder cleaning chamber; 16-second chamber; 17-third chamber; 18-fourth chamber; 19-operating platform; 20-front door; 21-glove port; 22-observation window; 23-hinge; 24-door lock; 25-control panel; 26-top door; 27-top door drive assembly; 28-opening and closing drive motor; 29-first connecting rod; 30-second connecting rod; 31-pressing assembly; 32-cylinder; 33-transmission block; 34-mounting seat; 35-connecting rod; 36-impact block; 37-flip assembly; 38-rotation assembly; 39-flip drive assembly; 40-flip frame; 41-encoder; 42-first follower; 43- First detection part; 44-second detection part; 45-third detection part; 46-carrying plate; 47-rotation drive assembly; 48-fourth detection part; 49-second follower; 50-side bulkhead; 51-bearing seat; 52-flip shaft; 53-bearing; 54-seal; 55-bottom wall; 56-powder drop port; 57-powder inlet pipe; 58-cover plate; 59-powder collecting funnel; 60-diverter; 61-powder outlet pipe; 62-horizontal pipe; 63-vertical pipe; 64-wheel; 65-handle; 66-mounting plate; K3-powder inlet; 200-printing part; 210-printing substrate; 71-metal powder particles; 72-powder agglomerates; K1-channel; K2-microchannel; P2-pore surface; X-horizontal direction; P1-carrying surface; L1-first axis; L2-second axis. DETAILED DESCRIPTION

[0042] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0043] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may also be an element centered therein. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may also be an element centered therein. When an element is considered to be "set on" another element, it may be directly set on the other element or there may also be an element centered therein. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" as used herein includes any and all combinations of one or more of the relevant listed items.

[0045] Some embodiments of the present application are described in detail. In the absence of conflict, the following embodiments and features of the embodiments can be combined with each other.

[0046] Example

[0047] Selective Laser Melting (SLM) is a technology that uses the thermal effect of a laser beam to rapidly melt and solidify metal powder.

[0048] During the printing process, not all metal powder is melted to form the printed part. Metal powder that is not melted by the laser may remain on the periphery of the printed part and in internal channels (if any). This metal powder must be removed from the printed part after printing. The removed metal powder can be screened and recycled for reuse.

[0049] See also Figure 1 After the printed part 200 is attached to the printing base 210, the unmelted metal powder on the periphery of the printed part 200 can be removed by gravity or manual brushing, making it easier to remove. However, the metal powder inside the internal channel K1 of the printed part 200 is more difficult to directly brush off manually.

[0050] The metal powders used in SLM printing include stainless steel powder, aluminum alloy, titanium alloy, etc. The particle size of some metal powders can range from ten to tens of microns.

[0051] During the actual printing process, due to the high temperature generated by the laser, some metal powder near the surface of the printed part 200 may be partially melted (i.e., not completely melted), forming powder agglomerates 72 that adhere to the surface of the printed part 200. Some powder agglomerates 72 may be larger than single metal powder particles, for example, exceeding 100 microns.

[0052] In addition, see Figure 1 Some of the channels K1 within printed parts 200 are microchannels K2 with smaller diameters (e.g., channels with diameters less than 1 mm). For example, some aerospace heat sinks may contain complex, curved microchannels K2 for the passage of cooling media (e.g., water, cooling oil, etc.). After SLM printing, these microchannels K2 of printed parts 200 may contain not only loosely packed metal powder particles 71 but also some larger powder agglomerates 72, as previously mentioned, adhering to the pore surfaces P2 of the microchannels K2.

[0053] It should be noted that Figure 1 The purpose is to simply illustrate the printed part 200 with the micro-channels K2 and does not represent the actual printed part 200.

[0054] See also Figure 2-Figure 4 This embodiment provides a toner cleaning device 100 that can efficiently clean toner from printed parts with good cleaning effects. An exemplary description will be given below.

[0055] See also Figure 2-Figure 4 The powder cleaning device 100 includes a frame 10, a movable platform 11, a vibration component 12, a control component 13 and a powder collecting component 14.

[0056] The movable platform 11 is movably mounted on the frame 10 for supporting and moving the printed workpiece 200. The vibration assembly 12 is mounted on the movable platform 11 for vibrating the printed workpiece 200 via the movable platform 11. The control assembly 13 is communicatively connected to the movable platform 11 and the vibration assembly 12.

[0057] The frame 10 may include a powder cleaning chamber 15, a second chamber 16, a third chamber 17, and a fourth chamber 18. The second chamber 16 is located on one side of the powder cleaning chamber 15 in the horizontal direction X and is used to accommodate the movable platform 11 together with the powder cleaning chamber 15. The third chamber 17 is located directly below the powder cleaning chamber 15 and is used to accommodate the powder collecting assembly 14. The powder collecting assembly 14 is connected to the bottom wall 55 of the powder cleaning chamber 15 and is used to collect metal powder removed from the powder cleaning chamber 15. The fourth chamber 18 is located below the second chamber 16 and is used to accommodate the control assembly 13, which can control the operation of the movable platform 11 and the vibration assembly 12.

[0058] The internal space of the frame 10 in this embodiment is rationally divided, compactly arranged, and neatly and beautifully designed. In addition, the powder cleaning device 100 in this embodiment may further include an operating platform 19 with steps (see FIG. Figure 2 ), which is used to facilitate personnel to go up and down the stairs to operate the powder cleaning device 100.

[0059] Continue to see Figure 2-Figure 4 In this embodiment, an openable front door 20 is provided at the front of the powder cleaning chamber 15. The front door 20 may be provided with a glove opening 21 for wearing gloves, allowing the user to manually clean the powder from the printed workpiece 200 or perform other operations. An observation window 22 may also be provided on the front door 20 to facilitate observation of the interior of the powder cleaning chamber 15. The front door 20 may be rotatably mounted via a hinge 23 on one side and locked or unlocked via a door lock 24 on the other side.

[0060] Continue to see Figure 2-Figure 4 The frame 10 may further include a control panel 25. The control panel 25 may include some control switches, buttons, touch screens, etc., which may be used to control the start, stop, and parameter settings of the powder cleaning device 100.

[0061] See also Figure 5 See also Figure 3 In this embodiment, an openable top door 26 is provided on the top of the powder cleaning chamber 15. This top door 26 can be opened to facilitate the vertical lifting of the printed workpiece 200 (along with the printing substrate 210 below it) into and out of the powder cleaning chamber 15. The top door 26 can be opened and closed manually or by a top door drive assembly 27.

[0062] Optionally, the top door 26 is rotatably mounted via a hinge 23. The top door drive assembly 27 includes an opening and closing drive motor 28, a first connecting rod 29, and a second connecting rod 30. The opening and closing drive motor 28 is fixedly connected to one end of the first connecting rod 29, and the other end of the first connecting rod 29 is hingedly connected to one end of the second connecting rod 30. The other end of the second connecting rod 30 is hingedly connected to the top door 26. In this manner, the opening and closing drive motor 28 can drive the top door 26 to open and close via the first connecting rod 29 and the second connecting rod 30.

[0063] See also Figure 5 and Figure 6, a clamping assembly 31 can also be arranged on both sides of the top door 26. The clamping assembly 31 is used to clamp the top door 26 after the top door 26 is closed to ensure that the powder cleaning chamber 15 is sealed at the top door 26, thereby reducing the possibility of metal powder in the powder cleaning chamber 15 leaking out. Optionally, the clamping assembly 31 includes a cylinder 32, a transmission block 33, a mounting seat 34, a connecting rod 35 and a bumper 36. The mounting seat 34 is fixedly arranged, and the connecting rod 35 is rotatably mounted on the mounting seat 34. The cylinder 32 is connected to one end of the connecting rod 35 through the transmission block 33, and the other end of the connecting rod 35 is connected to the bumper 36. In this way, when the cylinder 32 makes a linear motion, it can drive one end of the connecting rod 35 to displace, thereby causing the mounting seat 34 related to the connecting rod 35 to rotate, so that the bumper 36 at the other end of the connecting rod 35 clamps or releases the top door 26.

[0064] See also Figure 7-Figure 9 , the movable platform 11 includes a flip assembly 37 and a rotating assembly 38. The rotating assembly 38 includes a bearing surface P1, which is used to bear and fix the printed part 200. Optionally, the printed part 200 is hoisted together with the printing substrate 210 thereunder into the powder cleaning chamber, and the printed part 200 and the printing substrate 210 are fixedly supported on the bearing surface P1 by bolts or the like. The rotating assembly 38 can drive the printed part 200 to rotate around the first axis L1; wherein the first axis L1 is perpendicular to the bearing surface P1. The rotating assembly 38 is installed on the flip assembly 37, and can rotate around the second axis L2 driven by the flip assembly 37. wherein the second axis L2 is parallel to the horizontal direction X. The movable platform 11 has an initial state. In the initial state (see Figure 7 ), the bearing surface P1 is in a horizontal state.

[0065] In this embodiment, optionally, the flip assembly 37 includes a flip drive assembly 39, a flip frame 40, and an encoder 41. The flip drive assembly 39 is in driving connection with the flip frame 40, and is used to drive the flip frame 40 to rotate around the second axis L2.

[0066] The flip drive assembly 39 can be a motor. It can be operated under the control of the control assembly 13. The encoder 41 is used to detect the flip angle of the flip frame 40 in real time. The encoder 41 is communicatively connected to the control assembly 13. The control assembly 13 can receive the flip angle information detected by the encoder 41 and use it to determine whether to operate the flip drive assembly 39, thereby controlling the flip frame 40 to flip to the desired flip angle.

[0067] A first follower 42 is provided on the flip frame 40. The powder cleaning device 100 also includes a first detection member 43, a second detection member 44, and a third detection member 45, which are respectively connected to the control component 13 for communication. The first detection member 43, the second detection member 44, and the third detection member 45 are spaced apart along the circumference with the second axis L2 as the center. The first detection member 43 is located where the first follower 42 is when the movable platform 11 is in the initial state, and is used to calibrate the initial state of the flip frame 40; the second detection member 44 and the third detection member 45 are respectively located where the first follower 42 is when the movable platform 11 is at the maximum flip angle in the forward and reverse directions. When the second detection member 44 or the third detection member 45 detects the first follower 42, the control component 13 controls the flip component 37 to stop rotating. Optionally, a mounting plate 66 is fixed to the frame 10. The mounting plate 66 is located near one axial end of the flip shaft 52. The first follower 42 is provided on the axial end surface of the flip shaft 52 to rotate with the flip shaft 52. The first detection member 43, the second detection member 44, and the third detection member 45 are respectively mounted on the mounting plate 66.

[0068] The first detection member 43, the second detection member 44, and the third detection member 45 can be proximity sensors, and the first follower 42 can be a metal sheet that can be detected by the proximity sensor. In other embodiments, the first detection member 43, the second detection member 44, and the third detection member 45 can also be photoelectric sensors, Hall sensors, or other types of sensors, which are not limited here.

[0069] In this embodiment, the rotating assembly 38 includes a carrier plate 46 and a rotating drive assembly 47. The carrier plate 46 is rotatably mounted on the flip frame 40. The rotating drive assembly 47 is in driving connection with the carrier plate 46 and is configured to drive the carrier plate 46 to rotate about a first axis L1. The bearing surface P1 is the upper surface of the carrier plate 46. The rotating assembly 38 can drive the printed workpiece 200 to rotate circumferentially. The rotation speed of the rotating assembly 38 can be set to be relatively fast, so that while the printed workpiece 200 flips at a relatively low speed, it rotates circumferentially at a relatively high speed, ensuring that all sides of the outer circumference of the printed workpiece 200 can rotate to a downward position, and ensuring that the openings distributed on all sides of the outer circumference of the printed workpiece 200 can move to a downward position, so that the metal powder can be discharged from the printed workpiece 200 under the action of gravity or other external forces (such as vibration).

[0070] Optionally, in this embodiment, the flip frame 40 is fixedly connected to a fourth detection member 48, and the carrier plate 46 is fixed to a second follower 49. The fourth detection member 48 is located where the second follower 49 is when the carrier plate 46 rotates to zero point, and is used to calibrate the carrier plate 46 to zero point.

[0071] The fourth detecting member 48 may be a proximity sensor, and the second follower 49 may be a metal sheet that can be detected by the proximity sensor. In other embodiments, the fourth detecting member 48 may also be a photoelectric sensor, a Hall sensor, or other types of sensors, which are not limited here.

[0072] See also Figure 4 and Figure 10 In this embodiment, the powder cleaning chamber 15 is a sealed chamber, which can prevent the metal powder from diffusing outward during the powder cleaning process and affecting the external air quality.

[0073] Bearing seats 51 are fixedly provided outside the two side walls 50 on both sides of the powder cleaning chamber 15 along the horizontal direction X, and flip shafts 52 are connected to both sides of the flip frame 40. The two flip shafts 52 pass through the two side walls 50 respectively and are rotatably supported on the two bearing seats 51 through bearings 53.

[0074] The flip frame 40 is arranged in the powder cleaning chamber 15, and the flip drive assembly 39 is arranged in the second chamber 16 on the side of the powder cleaning chamber 15 in the horizontal direction X. The flip drive assembly 39 is connected to one of the flip shafts 52 by transmission, and is used to drive the flip frame 40 to flip through the flip shaft 52. In this way, the flip frame 40 in the powder cleaning chamber 15 can be easily connected to the flip drive assembly 39 outside the powder cleaning chamber 15 to avoid being affected by the operation of the flip drive assembly 39 in a metal powder environment. In addition, the flip drive assembly 39 is arranged in the second chamber 16 outside the powder cleaning chamber 15, which can also make more of the internal space of the powder cleaning chamber 15 available for accommodating the printed parts 200 to be cleaned. In this way, the powder cleaning device 100 can clean the powder for larger printed parts 200.

[0075] Optionally, a seal 54 is provided at the connection between the tilt shaft 52 and the side bulkhead 50 to ensure the sealing performance of the powder cleaning chamber 15. The seal 54 can be a labyrinth seal to achieve a better sealing effect. In other embodiments, the seal 54 can also be an O-ring or other sealing element.

[0076] In this embodiment, the powder cleaning chamber 15 has a bottom wall 55, and the powder collecting assembly 14 is connected to the bottom wall 55 of the powder cleaning chamber 15 to collect metal powder removed from the powder cleaning chamber 15. Optionally, the bottom wall 55 of the powder cleaning chamber 15 is funnel-shaped, with a powder dropout opening 56 defined at its bottom end. Metal powder falling from the printed workpiece 200 falls onto the bottom wall 55 and enters the powder collecting assembly 14 through the powder dropout opening 56, thereby being effectively collected and conveniently screened for reuse.

[0077] See also Figure 11-12In this embodiment, the powder collecting assembly 14 includes a powder inlet pipe 57, a cover plate 58, two powder collecting funnels 59, a diverter 60 and a powder outlet pipe 61. The two powder collecting funnels 59 are arranged in sequence along the horizontal direction X, and the cover plate 58 covers the two powder collecting funnels 59 to close the top of the powder collecting funnels 59. The powder inlet pipe 57 connects the powder drop port 56 and the powder inlet K3 opened on the cover plate 58. The diverter 60 is in an inverted V shape, and the upper end of the diverter 60 corresponds to the powder inlet K3, and the two sides correspond to the two powder collecting funnels 59, which are used to divert the powder passing through the powder inlet K3 to the two powder collecting funnels 59. The bottom ends of the two powder collecting funnels 59 are respectively connected to the powder outlet pipe 61, which is used to discharge the metal powder in the powder collecting funnel 59. The powder discharge pipe 61 can be a four-way pipe, comprising a horizontal pipe 62 and two vertical pipes 63. The two vertical pipes 63 vertically connect the horizontal pipe 62 to the bottoms of the two powder collecting hoppers 59, respectively. Metal powder collected by the powder collecting hoppers 59 can enter the horizontal pipe 62 through the corresponding vertical pipes 63 and be discharged along the horizontal pipe 62 via a conveying device (such as a blower). Optionally, a flow control device (such as an on / off valve or flow control valve) can be provided on the powder discharge pipe 61 to control the on / off state and flow rate of the powder discharge pipe 61.

[0078] Optionally, the powder collecting assembly 14 further includes wheels 64 and a handle 65 , so that the powder collecting assembly 14 is in the form of a powder collecting trolley, which facilitates the powder collecting assembly 14 to be pushed out of the powder cleaning device 100 for metal powder recovery.

[0079] In this embodiment, the control component 13 can control the vibration parameters of the vibration component 12 based on the position parameters of the movable platform 11. The position parameters include the flip angle, which is the angle at which the support surface P1 rotates around the second axis L2 during the movement from the initial state to the current state. The vibration parameters include the vibration frequency. For example, after the encoder 41 of the flip component 37 detects the flip angle, it can transmit the flip angle information to the control component 13. After receiving the flip angle information, the control component 13 determines the corresponding vibration frequency based on the flip angle and controls the vibration component 12 to operate at the vibration frequency.

[0080] The vibration assembly 12 may be a pneumatic hammer or other vibration devices.

[0081] This embodiment provides a powder cleaning method, which is based on the aforementioned powder cleaning device 100 and is used to clean the powder of the printed part 200.

[0082] The powder cleaning method comprises the following steps:

[0083] Step 1: The flip assembly 37 flips the printed workpiece 200 around the second axis L2 at a set speed (e.g., angular velocity w1), flipping the printed workpiece 200 from 0° to 90°. During this process, the rotating assembly 38 drives the printed workpiece 200 to rotate around the first axis L1 at a set speed (e.g., angular velocity w2), and the vibrating assembly 12 is controlled to vibrate at a first frequency.

[0084] Step 2: After step 1, print workpiece 200 is flipped from 90° to the maximum flip angle. Simultaneously, rotation assembly 38 rotates print workpiece 200 about first axis L1, and vibration assembly 12 is controlled to vibrate at the second frequency. Specifically, when the flip angle detected by encoder 41 reaches 90°, control assembly 13 controls vibration assembly 12 to switch from the first frequency to the second frequency based on the flip angle signal.

[0085] The maximum flip angle is greater than 90° and less than 180°, for example, 160°. The angular velocity w1 can be set to a relatively low value, for example, less than 10° / minute, to allow the printed workpiece 200 to flip slowly, ensuring sufficient powder removal at various flip angles. The angular velocity w2 can be set to a relatively high value, for example, greater than 60° / minute.

[0086] Optionally, after step 2, the powder cleaning method may further include step 3.

[0087] Step three is: keeping the printed part 200 at the maximum flip angle, allowing the rotating assembly 38 to drive the printed part 200 to rotate around the first axis L1, and allowing the vibration assembly 12 to operate at a third frequency for a set time (such as 20 minutes); the third frequency is greater than the second frequency.

[0088] In one embodiment, the printed part 200 is made of stainless steel powder and printed by an SLM type 3D printing device with a plurality of micro-channels K2 (see Figure 1 ) printed part 200. The microchannels K2 herein refer to channels with smaller pore diameters, such as channels K1 with diameters less than 1 mm. In addition to the metal powder particles 71 loosely retained within the elongated microchannels K2 during the printing process, some semi-sintered metal powder adheres to the pore surfaces P2 of the microchannels K2. Some of this adherent metal powder aggregates into larger powder agglomerates 72.

[0089] In step 1, see Figure 13Unattached metal powder particles 71 within the microchannels K2 are gradually cleared from the microchannels K2. However, powder agglomerates 72 adhering to the pore surfaces P2 of the microchannels K2 do not, or only rarely, fall off the pore surfaces P2 of the microchannels K2, remaining dispersed and adhered thereto. In other words, larger powder agglomerates 72 do not fall off in large numbers and therefore do not aggregate under the first vibration frequency and become stuck in certain locations within the microchannels K2. For the stainless steel powder printed part of this embodiment, the first frequency can be set to 30-36 VPM (i.e., 30-36 vibrations per minute), such as 30 VPM, 33 VPM, or 36 VPM.

[0090] After step 1 is completed, step 2 is performed to make the sticky powder agglomerates 72 fall off from the hole surface P2 of the micro-channel K2. Figure 14 Because the unattached metal powder particles 71 within the microchannels K2 have already been discharged from them in step 1, the microchannels K2 are relatively empty. After being vibrated away from the aperture surface P2 of the microchannels K2, powder agglomerates 72 can be discharged from the microchannels K2 unimpeded. This reduces the likelihood of powder agglomeration and clogging the microchannels K2 during vibration, ensuring effective powder cleaning. For the stainless steel powder prints of this embodiment, the second frequency can be 42-43 VPM, such as 42 VPM, 42.5 VPM, or 43 VPM.

[0091] In some cases, there may be a small number of tightly bound powder clumps 72. Vibrating at a higher frequency (the third frequency) in step three can effectively remove these powder clumps 72, further ensuring powder cleaning. For the stainless steel powder prints of this embodiment, the third frequency can be 45 VPM or higher, for example, 45-50 VPM, such as 45 VPM, 45.5 VPM, 48 VPM, or 50 VPM.

[0092] In contrast, some known powder cleaning modes set the vibration frequency to be low, which cannot make the adhered powder agglomerates 72 fall off. Other known powder cleaning modes set the vibration frequency to be high, which may cause the loose metal powder particles 71 to be shaken off before they fully flow out of the micro-channels K2 (see Figure 15 ), based on the size difference between the loose metal powder particles 71 and the powder agglomerates 72, these powder agglomerates 72 may aggregate together under the action of vibration, especially at the larger bends of the microchannel K2 (see Figure 16), since these powder agglomerates 72 are likely to be irregular in shape rather than spherical like the metal powder particles 71, their fluidity is very poor. When a large number of powder agglomerates 72 are close to each other and aggregate, they may interlock and become stuck in certain locations (such as bends) of the microchannel K2, preventing the metal powder particles 71 behind from being poured out of the microchannel K2. To address this issue, conventional technologies tend to use powder cleaning methods other than vibration, such as pickling and electrolytic polishing. However, while pickling and electrolytic polishing provide more thorough powder cleaning, they can damage the surface of the microchannel K2 of the printed part 200 and may also cause the microchannel K2 to become larger, affecting the dimensional accuracy of the printed part 200.

[0093] The solution of this embodiment can effectively solve the problem of circumventing the known solution, and the powder cleaning effect can be guaranteed.

[0094] See also Figure 17 In another embodiment, the powder cleaning method further includes selecting a powder cleaning mode. In the powder cleaning method, after the powder cleaning device 100 is powered on, a powder cleaning mode can be selected, and the powder cleaning mode includes a manual mode and an automatic mode.

[0095] If the user selects manual mode, they can manually control the flip angle and rotation angle, and can also manually switch the vibration frequency. Manual mode is more flexible and can combine flipping at the appropriate angle and rotation speed while maintaining the appropriate vibration frequency (such as the third frequency) to achieve the best powder cleaning effect.

[0096] If the user selects the automatic mode, the above steps 1, 2 and 3 are executed in sequence.

[0097] In some embodiments, the switching timings of step one, step two, and step three may also be determined jointly by the powder cleaning time condition and the flip angle condition.

[0098] For example Figure 17 In the embodiment, after the automatic mode is selected, the movement duration of the print member 200 is determined.

[0099] If the exercise time is less than or equal to 10 minutes, the flip angle is judged. If the flip angle is less than or equal to 90°, step one is executed to run at the first frequency. After the flip angle is greater than 90°, step two is executed to run at the second frequency.

[0100] After the exercise duration exceeds 10 minutes, the machine will start running at the third frequency and proceed to step 3. Step 3 can be executed for 20 minutes to ensure the powder removal effect.

[0101] In summary, the powder cleaning device 100 and the powder cleaning method of this embodiment have a better powder cleaning effect and can well cope with the powder cleaning of the printed part 200 with the micro-channels K2.

[0102] Furthermore, in this embodiment, the rotary drive assembly 47 of the powder cleaning device 100 is located outside the powder cleaning chamber 15. This prevents metal powder from easily entering the rotary drive assembly 47 during powder cleaning and affecting its function. Both the rotary drive assembly 47 and the powder collecting assembly 14 are located outside the powder cleaning chamber 15, eliminating the need to occupy the interior space of the chamber. This allows the interior space of the chamber to be fully utilized to accommodate the printed workpiece 200 to be cleaned.

[0103] The above embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit the present application. Although the present application has been described in detail with reference to the above preferred embodiments, those skilled in the art should understand that modifications or equivalent replacements of the technical solutions of the present application should not depart from the spirit and scope of the technical solutions of the present application.

Claims

1. A powder cleaning device for cleaning powder from SLM metal 3D printed parts, characterized in that: The powder cleaning device comprises: frame; A movable platform, movably provided on the frame, for carrying the printed workpiece and driving the printed workpiece to move; a vibration component, mounted on the movable platform, for driving the printed part to vibrate via the movable platform; and a control component, communicatively connected to the movable platform and the vibration component, and configured to control vibration parameters of the vibration component based on position parameters of the movable platform; The movable platform includes a flip component and a rotation component; The rotating assembly includes a bearing surface, the bearing surface being used to bear and fix the printed part; the rotating assembly is capable of driving the printed part to rotate around a first axis; wherein the first axis is perpendicular to the bearing surface; The rotating assembly is mounted on the flip assembly and is capable of rotating around a second axis driven by the flip assembly; wherein the second axis is parallel to the horizontal direction; The movable platform has an initial state, in which the bearing surface is horizontal; The position parameter includes a flip angle, which is an angle at which the bearing surface rotates around the second axis during movement from an initial state to a current state; The vibration parameters include vibration frequency; When the flip angle changes from 0° to 90°, the control component is used to control the vibration component to vibrate at a first frequency; when the flip angle changes from 90° to a maximum flip angle, the control component is used to control the vibration component to vibrate at a second frequency, wherein the second frequency is greater than the first frequency, and the maximum flip angle is greater than 90° and less than 180°; The flip assembly includes a flip drive assembly, a flip frame and an encoder; The flip drive assembly is in driving connection with the flip frame, and is used to drive the flip frame to rotate about the second axis; the encoder is used to detect the flip angle of the flip frame in real time; the encoder is communicatively connected to the control assembly, and when the flip angle detected by the encoder reaches 90°, the control assembly controls the vibration assembly to switch from the first frequency to the second frequency; The turning frame is provided with a first follower; The powder cleaning device further includes a first detection member, a second detection member, and a third detection member, which are respectively in communication with the control assembly; the first detection member, the second detection member, and the third detection member are spaced apart along the circumferential direction with the second axis as the center; The first detection member is located where the first follower is located when the movable platform is in the initial state, and is used to calibrate the initial state of the flip frame; The second detection member and the third detection member are respectively located at the position where the first follower is located when the movable platform is at the maximum forward and reverse flipping angles. When the second detection member or the third detection member detects the first follower, the control component controls the flipping component to stop rotating.

2. The powder cleaning device according to claim 1, characterized in that: The rotating assembly includes a carrier plate and a rotating drive assembly; The carrier plate is rotatably mounted on the flip frame, and the rotation drive assembly is in transmission connection with the carrier plate to drive the carrier plate to rotate around the first axis; the bearing surface is the upper surface of the carrier plate; The flip frame is fixedly connected to a fourth detection member, and the carrying plate is fixed to a second follower; The fourth detecting member is located at the position where the second follower is located when the carrying plate rotates to the zero point, and is used to perform zero point calibration on the carrying plate.

3. The powder cleaning device according to claim 1, characterized in that: The frame includes a powder cleaning cabin, which is a sealed cabin; Bearing seats are respectively installed outside the two side bulkheads on both sides of the powder cleaning chamber in the horizontal direction, and the two sides of the turnover frame are respectively connected to turnover shafts, and the two turnover shafts respectively pass through the two side bulkheads and are rotatably supported on the two bearing seats; The flip drive assembly is transmission-connected to one of the flip shafts, and is used for driving the flip frame to flip via the flip shaft.

4. The powder cleaning device according to claim 3, characterized in that: The powder cleaning device also includes a powder collecting component; The frame also includes a second compartment, a third compartment and a fourth compartment; The second cabin is located on one side of the powder cleaning cabin in the horizontal direction and is used to accommodate the flip drive assembly; The third cabin is located directly below the powder cleaning cabin and is used to accommodate the powder collecting assembly; The powder collecting assembly is connected to the bottom wall of the powder cleaning chamber and is used to collect powder dropped from the powder cleaning chamber; The fourth compartment is arranged below the second compartment and is used to accommodate the control component.

5. The powder cleaning device according to claim 4, characterized in that: The bottom wall of the powder cleaning cabin is funnel-shaped, and a powder dropout port is provided at the bottom end of the bottom wall; The powder collecting assembly includes a powder inlet pipe, a cover plate, two powder collecting funnels, a diverter and a powder outlet pipe; The two powder collecting funnels are arranged in sequence along the horizontal direction, and the cover plate covers the two powder collecting funnels; The powder inlet pipe is connected to the powder drop port and the powder inlet opened on the cover plate; The diverter is in an inverted V shape, and the upper end of the diverter corresponds to the powder inlet, and the two sides of the diverter correspond to the two powder collecting funnels, respectively, for diverting the powder passing through the powder inlet to the two powder collecting funnels; The bottom ends of the two powder collecting funnels are respectively connected to the powder outlet pipes, and the powder outlet pipes are used to discharge the powder in the powder collecting funnels.

6. A powder cleaning method, characterized in that: Based on the powder cleaning device according to any one of claims 1 to 5, the powder cleaning method includes: The flipping assembly flips the printed workpiece around the second axis at a set speed, flipping the printed workpiece from 0° to 90°. At the same time, the rotating assembly drives the printed workpiece to rotate around the first axis, and the vibrating assembly is controlled to vibrate at a first frequency. Then, the printed part is flipped from 90° to a maximum flip angle, which is greater than 90°. At the same time, the rotating component drives the printed part to rotate around the first axis, and the vibration component is controlled to vibrate at a second frequency.

7. The powder cleaning method according to claim 6, characterized in that: The powder cleaning method also includes: maintaining the printed part at a maximum flip angle, causing the rotating component to drive the printed part to rotate around the first axis, and causing the vibration component to operate at a third frequency for a set time; the third frequency is greater than the second frequency.

8. The powder cleaning method according to claim 7, characterized in that: The printed part is a printed part with a plurality of micro-channels made of stainless steel powder by SLM type 3D printing equipment; The first frequency is 30-36 VPM, the second frequency is 42-43 VPM, and the third frequency is greater than 45 VPM; The vibration component operates at the first frequency to enable loose metal powder particles in the micro-channel to flow out of the micro-channel; The vibration component operates at the second frequency, so that the sticky powder agglomerates attached to the hole surface of the micro-channel can fall off from the printed part and flow out of the micro-channel.

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