Powder cleaning device and powder cleaning method

Abstract

The invention relates to the technical field of metal 3D printing post-processing, aims to solve the problem that a powder cleaning scheme in the prior art is poor in powder cleaning effect, and provides a powder cleaning device and a powder cleaning method. The powder cleaning device comprises a rack, a movable platform and a control assembly. The movable platform is movably arranged on the rack and used for bearing a printing piece and driving the printing piece to move. The vibration assembly is installed on the movable platform and used for driving the printing piece to vibrate through the movable platform. The control assembly is in communication connection with the movable platform and the vibration assembly and used for controlling vibration parameters of the vibration assembly based on the position parameters of the movable platform. The powder cleaning device has the beneficial effects of being reasonable in structural arrangement and good in powder cleaning effect.

Description

Technical Field

[0001] This application relates to the technical field of post-processing of metal 3D printing, and more specifically, 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 rapidly melts and solidifies metal powder through the thermal action of a laser beam.

[0003] During the printing process, not all metal powder will be formed into a printed part. The unformed metal powder usually needs to be recycled and screened after printing for reuse.

[0004] When some known powder cleaning devices and powder cleaning methods are used, there may be problems such as incomplete powder cleaning and residual metal powder in the internal channels of the printed part, resulting in poor powder cleaning effect. Summary of the Invention

[0005] This application provides a powder cleaning device and a powder cleaning method to solve the problem of poor powder cleaning effect in the known powder cleaning solutions.

[0006] In a first aspect, an embodiment of this application provides a powder cleaning device for cleaning a printed part 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 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 communicatively connected to 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.

[0007] In a possible implementation manner, the movable platform includes a flipping component and a rotating component. The rotating component includes a bearing surface for carrying and fixing the printed part; the rotating component can drive the printed part to rotate around a first axis; wherein, the first axis is perpendicular to the bearing surface. The rotating component is installed on the flipping component and can rotate around a second axis under the drive of the flipping component; wherein, the second axis is parallel to the horizontal direction. The movable platform has an initial state, and in the initial state, the bearing surface is in a horizontal state. The position parameter includes the flipping angle, and the flipping angle is the angle by which the bearing surface rotates around the second axis during the process of moving from the initial state to the current state. The vibration parameter includes the vibration frequency. During the process of the flipping angle changing from 0° to 90°, the control component is used to control the vibration component to vibrate at a first frequency; during the process of the flipping angle changing from 90° to the maximum flipping angle, the control component is used to control the vibration component to vibrate at a second frequency, where the second frequency is greater than the first frequency, and the maximum flipping angle is greater than 90° and less than 180°.

[0008] In a possible implementation, the flipping assembly includes a flipping drive assembly, a flipping frame, and an encoder. The flipping drive assembly is drivingly connected to the flipping frame and is used to drive the flipping frame to rotate around the second axis; the encoder is used to detect the flipping angle of the flipping frame in real time; the encoder is communicatively connected to the control assembly, and when the flipping 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 flipping frame. The purifying device further includes a first detector, a second detector, and a third detector, and the first detector, the second detector, and the third detector are respectively communicatively connected to the control assembly; the first detector, the second detector, and the third detector are circumferentially spaced apart with the second axis as the center. The first detector 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 flipping frame. The second detector and the third detector are respectively located at the positions where the first follower is located when the movable platform is at the maximum positive and negative flipping angles. When the second detector or the third detector detects the first follower, the control assembly controls the flipping assembly to stop rotating further.

[0009] In a possible implementation, the rotating assembly includes a bearing plate and a rotating drive assembly. The bearing plate is rotatably mounted on the flipping frame, and the rotating drive assembly is drivingly connected to the bearing plate and is used to drive the bearing plate to rotate around the first axis; the bearing surface is the upper surface of the bearing plate. A fourth detector is fixedly connected to the flipping frame, and a second follower is fixed to the bearing plate. The fourth detector is located at the position where the second follower is located when the bearing plate rotates to zero, and is used to calibrate the zero point of the bearing plate.

[0010] In a possible implementation, the frame includes a purifying chamber, and the purifying chamber is a sealed chamber body. Bearing seats are respectively installed outside the two side cabin walls on both sides of the purifying chamber in the horizontal direction. Shaft members for flipping are respectively connected to both sides of the flipping frame, and the two shaft members for flipping respectively pass through the two side cabin walls and are rotatably supported by the two bearing seats. The flipping drive assembly is drivingly connected to one of the shaft members for flipping and is used to drive the flipping frame to flip through the shaft member for flipping.

[0011] In a possible implementation, the purifying device further includes a powder collecting assembly. The frame further includes a second chamber, a third chamber, and a fourth chamber. The second chamber is located on one side of the purifying chamber in the horizontal direction and is used to accommodate the flipping drive assembly. The third chamber is located directly below the purifying chamber and is used to accommodate the powder collecting assembly; the powder collecting assembly is communicated with the bottom wall of the purifying chamber and is used to collect the powder cleared from the purifying chamber. The fourth chamber is provided below the second chamber and is used to accommodate the control assembly.

[0012] In a possible implementation, the bottom wall of the purifying powder bin is funnel-shaped, and a powder discharging port is opened 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 shunt member, 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 communicates with the powder discharging port and the powder inlet opened on the cover plate. The shunt member is in an inverted V shape, and the upper end of the shunt member corresponds to the powder inlet, and the two sides respectively correspond to the two powder collecting funnels, and is used for shunting and guiding the powder passing through the powder inlet to the two powder collecting funnels. The bottom ends of the two powder collecting funnels are respectively communicated with the powder outlet pipe, and the powder outlet pipe is used for discharging the powder in the powder collecting funnel.

[0013] In a second aspect, an embodiment of the present application provides a powder purifying method, which is based on the aforementioned powder purifying device. The powder purifying method includes: Rotating the printed part around the second axis at a set speed by the flipping assembly, flipping the printed part from 0° to 90°, and at the same time, driving the printed part to rotate around the first axis by the rotating assembly, and controlling the vibration assembly to vibrate at a first frequency; Then, flipping the printed part from 90° to the maximum flipping angle, the maximum flipping angle is greater than 90°, and at the same time, driving the printed part to rotate around the first axis by the rotating assembly, and controlling the vibration assembly to vibrate at a second frequency.

[0014] In a possible implementation, the powder purifying method further includes: keeping the printed part at the maximum flipping angle, driving the printed part to rotate around the first axis by the rotating assembly, and operating the vibration assembly at a third frequency for a set time; the third frequency is greater than the second frequency.

[0015] In a possible implementation, the printed part is a printed part with a plurality of microchannels printed by an SLM type 3D printing device from stainless steel powder; The first frequency is 30 - 36 VPM, the second frequency is 42 - 43 VPM, and the third frequency is greater than 45 VPM; When the vibration assembly operates at the first frequency, the loose metal powder particles in the microchannels can flow out of the microchannels; When the vibration assembly operates at the second frequency, the adhesive powder agglomerates attached to the pore surface of the microchannels can fall off from the printed part and flow out of the microchannels.

[0016] In summary, the powder purifying device and the powder purifying method of this embodiment have a better powder purifying effect and can well handle the powder purifying of the printed part with microchannels.

[0017] In addition, in this embodiment, the rotation drive assembly of the powder cleaning device is arranged outside the powder cleaning chamber. During powder cleaning, metal powder is not likely to enter the interior of the rotation drive assembly and affect its function. Both the rotation drive assembly and the powder collection assembly are arranged outside the powder cleaning chamber, without occupying the internal space of the powder cleaning chamber, so that the internal space of the powder cleaning chamber can be fully utilized to accommodate the printed parts to be powder-cleaned. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] To more clearly illustrate the technical solutions of the embodiments of the present application, the accompanying drawings in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application, and thus should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0019] Figure 1 It is a structural schematic diagram of a printed part according to an embodiment of the present application.

[0020] Figure 2 It is a perspective view of the powder cleaning device according to an embodiment of the present application.

[0021] Figure 3 It is Figure 2 a perspective view of a partial structure of the powder cleaning device.

[0022] Figure 4 It is Figure 3 a cross-sectional view.

[0023] Figure 5 It is a perspective view of the top door and the top door drive assembly.

[0024] Figure 6 It is a perspective view of the pressing assembly.

[0025] Figure 7 It is a structural schematic diagram of the movable platform and the printed part.

[0026] Figure 8 It is Figure 7 an exploded view.

[0027] Figure 9 It is Figure 8 a partial enlarged view.

[0028] Figure 10 It is Figure 4 a partial enlarged view.

[0029] Figure 11 It is a perspective view of the powder cleaning assembly.

[0030] Figure 12 It is Figure 11 a cross-sectional view of the powder cleaning assembly.

[0031] Figure 13 It is a schematic diagram of the first powder cleaning process state when cleaning the powder of the print of this application.

[0032] Figure 14 It is a schematic diagram of another powder cleaning process state when cleaning the powder of the print of this application.

[0033] Figure 15 It is a schematic diagram of the first powder cleaning process state when cleaning the powder of the print in a known solution.

[0034] Figure 16 It is Figure 15 a schematic diagram of another powder cleaning process state when cleaning the powder of the print in the known solution of

[0035] Figure 17 It is a flowchart of the powder cleaning method according to another embodiment of this application.

[0036] Description of main component symbols: 100 - powder cleaning device; 10 - frame; 11 - movable platform; 12 - vibration assembly; 13 - control assembly; 14 - powder collection assembly; 15 - powder cleaning chamber; 16 - second chamber; 17 - third chamber; 18 - fourth chamber; 19 - operation 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 - striker; 37 - flipping assembly; 38 - rotating assembly; 39 - flipping drive assembly; 40 - flipping frame; 41 - encoder; 42 - first follower; 43 - first detector; 44 - second detector; 45 - third detector; 46 - bearing plate; 47 - rotating drive assembly; 48 - fourth detector; 49 - second follower; 50 - side bulkhead; 51 - bearing seat; 52 - flipping shaft member; 53 - bearing; 54 - seal; 55 - bottom wall; 56 - powder dropping port; 57 - powder inlet pipe; 58 - cover plate; 59 - powder collection funnel; 60 - shunt member; 61 - powder outlet pipe; 62 - horizontal pipe; 63 - vertical pipe; 64 - wheel; 65 - handle; 66 - mounting plate; K3 - powder inlet; 200 - print; 210 - print substrate; 71 - metal powder particle; 72 - powder agglomerate; K1 - channel; K2 - microchannel; P2 - pore surface; X - horizontal direction; P1 - bearing surface; L1 - first axis; L2 - second axis. Detailed implementation manners

[0037] Next, the technical solutions in the embodiments of this application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments.

[0038] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there can also be an intermediate element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intermediate element at the same time. When an element is considered to be "disposed on" another element, it can be directly disposed on the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are only for illustrative purposes.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill 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" used herein includes any and all combinations of one or more of the related listed items.

[0040] Some embodiments of this application will be described in detail. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0041] Embodiment Selective Laser Melting (SLM) is a technology that rapidly melts and solidifies metal powder through the thermal action of a laser beam.

[0042] During the printing process, not all metal powders will be used to melt and form the printed part. The metal powders that are not melted by the laser irradiation will remain in the outer periphery and internal channels (if any) of the printed part. These metal powders need to be removed from the printed part after the printing of the printed part is completed. The removed metal powders can be screened and recycled for reuse.

[0043] See Figure 1 , the printed part 200 after printing is combined on the printing substrate 210. After the printed part 200 is lifted, the unmelted metal powders on the outer periphery of the printed part 200 can be separated from the printed part 200 under the action of gravity or manual brushing, and the cleaning is relatively simple. However, it is relatively difficult to directly remove the metal powders in the internal channel K1 of the printed part 200 manually.

[0044] The metal powders used in SLM printing include stainless steel powders, aluminum alloys, titanium alloys, etc. The particle sizes of some metal powders can be between ten and dozens of micrometers.

[0045] During the actual printing process, due to the high temperature generated by the laser, some metal powders near the surface of the printed part 200 may be partially melted (i.e., not completely melted) to form powder agglomerates 72 adhering to the surface of the printed part 200. Some of the powder agglomerates 72 may have a larger size compared to single metal powder particles, for example, they may reach more than 100 microns.

[0046] In addition, continue to refer to Figure 1 , some of the channels K1 inside the printed part 200 are microchannels K2 with a smaller diameter (such as channels with a diameter less than 1 mm). For example, for some heat dissipation parts in the aviation field, there may be complexly curved and extended microchannels K2 inside them, which are used to pass cooling media (such as water, cooling oil, etc.). After printing is completed by the SLM technology, inside the microchannels K2 of these printed parts 200, in addition to the metal powder particles 71 loosely filled therein, there may also be some of the aforementioned larger-sized powder agglomerates 72 adhering to the pore surface P2 of the microchannels K2.

[0047] It should be noted that Figure 1 the printed part 200 with the microchannel K2 is intended to be simply schematic and does not represent the real printed part 200.

[0048] Refer to Figures 2 - 4 , this embodiment provides a powder cleaning device 100, which can efficiently achieve powder cleaning of the printed part and has a good powder cleaning effect. The following will be an exemplary introduction.

[0049] Refer to Figures 2 - 4 , the powder cleaning device 100 includes a frame 10, a movable platform 11, a vibration assembly 12, a control assembly 13, and a powder collection assembly 14.

[0050] The movable platform 11 is movably arranged on the frame 10, and is used to carry the printed part 200 and drive the printed part 200 to move. The vibration assembly 12 is installed on the movable platform 11 and is used to drive the printed part 200 to vibrate through the movable platform 11. The control assembly 13 is respectively communicatively connected to the movable platform 11 and the vibration assembly 12.

[0051] 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 jointly accommodate the movable platform 11 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 collection assembly 14. The powder collection assembly 14 communicates with the bottom wall 55 of the powder cleaning chamber 15 and is used to collect the metal powder falling from the powder cleaning chamber 15. The fourth chamber 18 is arranged below the second chamber 16 and is used to accommodate the control assembly 13, and the control assembly 13 can control the operation of the movable platform 11 and the vibration assembly 12.

[0052] In this embodiment, the internal space of the frame 10 is reasonably divided, the arrangement is compact, and the appearance is neat and beautiful. In addition, the flour cleaning device 100 of this embodiment may further include an operating platform 19 with steps (as shown in Figure 2 ), which is used to facilitate personnel to go up and down through the steps to operate the flour cleaning device 100.

[0053] Continue to refer to Figures 2 - 4 . In this embodiment, a front door 20 that can be opened is provided at the front of the flour cleaning chamber 15. The front door 20 may be provided with a glove port 21 for installing gloves, so as to facilitate the user to put his hand into the flour cleaning chamber 15 to perform manual flour cleaning operations or other operations on the printed matter 200. An observation window 22 may also be provided on the front door 20 to facilitate observing the internal situation of the flour cleaning chamber 15. The front door 20 may be rotatably provided through a hinge 23 on one side and locked or unlocked through a door lock 24 on the other side.

[0054] Continue to refer to Figures 2 - 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 can be used to control the start, stop, and parameter settings of the flour cleaning device 100, etc.

[0055] Refer to Figure 5 And refer to in cooperation with Figure 3 . In this embodiment, a top door 26 that can be opened is provided at the top of the flour cleaning chamber 15. The top door 26 can be opened to facilitate the vertical hoisting of the printed matter 200 (together with the printing substrate 210 below it) in and out of the flour cleaning chamber 15. The top door 26 can be opened and closed manually or driven by a top door driving assembly 27 to open and close.

[0056] Optionally, the top door 26 is rotatably provided through a hinge 23, and the top door driving assembly 27 includes an opening and closing driving motor 28, a first connecting rod 29, and a second connecting rod 30. One end of the opening and closing driving motor 28 is fixedly connected to one end of the first connecting rod 29, the other end of the first connecting rod 29 is hinged to one end of the second connecting rod 30, and the other end of the second connecting rod 30 is hinged to the top door 26. In this way, the opening and closing driving motor 28 can drive the top door 26 to open and close through the first connecting rod 29 and the second connecting rod 30.

[0057] Refer to in cooperation with 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 leakage of metal powder in the powder cleaning chamber 15. Optionally, the clamping assembly 31 includes a cylinder 32, a transmission block 33, a mounting seat 34, a connecting rod 35 and a collision block 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 collision block 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 rotating the mounting seat 34 related to the connecting rod 35, so that the collision block 36 at the other end of the connecting rod 35 clamps or releases the top door 26.

[0058] See also Figures 7 - 9 , the movable platform 11 includes a flip assembly 37 and a rotating assembly 38. The rotating assembly 38 includes a bearing surface P1, and the bearing surface P1 is used to bear and fix the print 200. Optionally, the print 200 is hoisted together with the printing substrate 210 thereunder into the powder cleaning chamber, and the print 200 and the printing substrate 210 are fixedly supported on the bearing surface P1 as a whole by bolts or the like. The rotating assembly 38 can drive the print 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.

[0059] In this embodiment, optionally, the flip assembly 37 includes a flip driving assembly 39, a flip frame 40 and an encoder 41. The flip driving assembly 39 is connected to the flip frame 40 in a transmission manner to drive the flip frame 40 to rotate around the second axis L2.

[0060] 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, and the control assembly 13 can receive the flip angle information detected by the encoder 41 to determine and instruct the flip drive assembly 39 to operate, thereby controlling the flip frame 40 to flip to a desired flip angle.

[0061] The turnover frame 40 is provided with a first follower 42. The flour cleaning device 100 further includes a first detector 43, a second detector 44 and a third detector 45, and the first detector 43, the second detector 44 and the third detector 45 are respectively communicatively connected to the control assembly 13. The first detector 43, the second detector 44 and the third detector 45 are circumferentially spaced apart with the second axis L2 as the center. The first detector 43 is located at the position where the first follower 42 is located when the movable platform 11 is in the initial state, and is used for calibrating the initial state of the turnover frame 40; the second detector 44 and the third detector 45 are respectively located at the positions where the first follower 42 is located when the movable platform 11 is at the maximum forward and reverse turnover angles. When the second detector 44 or the third detector 45 detects the first follower 42, the control assembly 13 controls the turnover assembly 37 to stop rotating. Optionally, a mounting plate 66 is fixed on the frame 10. The mounting plate 66 is located near one axial end of the turnover shaft member 52. The first follower 42 is arranged on the axial end surface of the turnover shaft member 52 to rotate with the turnover shaft member 52. The first detector 43, the second detector 44 and the third detector 45 are respectively mounted on the mounting plate 66.

[0062] The first detector 43, the second detector 44 and the third detector 45 may be proximity sensors, and the first follower 42 may be a metal sheet that can be detected by the proximity sensors. In other embodiments, the first detector 43, the second detector 44 and the third detector 45 may also be photoelectric sensors, Hall sensors or other forms of sensors, which are not limited herein.

[0063] In this embodiment, the rotating assembly 38 includes a bearing disc 46 and a rotation driving assembly 47. The bearing disc 46 is rotatably mounted on the turnover frame 40. The rotation driving assembly 47 is drivingly connected to the bearing disc 46 for driving the bearing disc 46 to rotate around the first axis L1; the bearing surface P1 is the upper surface of the bearing disc 46. The rotating assembly 38 can drive the printed part 200 to rotate circumferentially, and the rotation speed of the rotating assembly 38 can be set relatively fast, so that while the printed part 200 is turned over at a lower speed, it rotates circumferentially at a faster speed, ensuring that all sides of the outer peripheral surface of the printed part 200 can be rotated to face downward, and ensuring that the openings distributed on all sides of the outer peripheral surface of the printed part 200 can all move to face downward, so that the metal powder can be discharged from the printed part 200 under the action of gravity or other external forces (such as vibration).

[0064] Optionally, in this embodiment, the turnover frame 40 is fixedly connected with a fourth detector 48, and the bearing disc 46 is fixed with a second follower 49. The fourth detector 48 is located at the position where the second follower 49 is located when the bearing disc 46 rotates to zero, and is used for calibrating the zero point of the bearing disc 46.

[0065] The fourth detection member 48 may be a proximity sensor, and the second follower member 49 may be a metal sheet that can be detected by the proximity sensor. In other embodiments, the fourth detection member 48 may also be a photoelectric sensor, a Hall sensor, or other forms of sensors, which are not limited herein.

[0066] Refer to Figure 4 and Figure 10 , in this embodiment, the purifying chamber 15 is a sealed chamber, so as to avoid the outward diffusion of metal powder during powder purification and affect the external air quality.

[0067] Bearing seats 51 are respectively fixedly arranged outside the two side cabin walls 50 on both sides of the purifying chamber 15 along the horizontal direction X. Shaft members 52 are respectively connected to both sides of the flipping frame 40. The two shaft members 52 respectively pass through the two side cabin walls 50 and are rotatably supported on the two bearing seats 51 through bearings 53.

[0068] The flipping frame 40 is arranged in the purifying chamber 15, and the flipping drive assembly 39 is arranged in the second chamber 16 on one side of the purifying chamber 15 along the horizontal direction X. The flipping drive assembly 39 is drivingly connected to one of the shaft members 52 for driving the flipping frame 40 to flip through the shaft member 52. In this way, the connection between the flipping frame 40 in the purifying chamber 15 and the flipping drive assembly 39 outside the purifying chamber 15 can be conveniently realized, so as to avoid the flipping drive assembly 39 from being affected when operating in a metal powder environment. In addition, the flipping drive assembly 39 is arranged in the second chamber 16 outside the purifying chamber 15, which can also make the internal space of the purifying chamber 15 more used for accommodating the print 200 to be purified. In this way, the powder purification device 100 can purify a larger print 200.

[0069] Optionally, a sealing member 54 is provided at the connection between the shaft member 52 and the side cabin wall 50 to ensure the sealing performance of the purifying chamber 15. The sealing member 54 may be a labyrinth sealing member to achieve a better sealing effect. In other embodiments, the sealing member 54 may also be an O-ring or other sealing elements.

[0070] In this embodiment, the purifying chamber 15 has a bottom wall 55, and the powder collecting assembly 14 communicates with the bottom wall 55 of the purifying chamber 15 for collecting the metal powder falling from the purifying chamber 15. Optionally, the bottom wall 55 of the purifying chamber 15 is funnel-shaped, and a powder dropping port 56 is opened at the bottom end of the bottom wall 55. The metal powder falling from the print 200 drops on the bottom wall 55 and enters the powder collecting assembly 14 through the powder dropping port 56 on the bottom wall 55, so as to be well collected and facilitate subsequent screening and reuse.

[0071] Refer to Figures 11 - 12, in this embodiment, the powder collection assembly 14 includes a powder inlet pipe 57, a cover plate 58, two powder collection funnels 59, a flow divider 60 and a powder outlet pipe 61. The two powder collection funnels 59 are arranged in sequence along the horizontal direction X. The cover plate 58 covers the two powder collection funnels 59 to seal the tops of the powder collection funnels 59. The powder inlet pipe 57 communicates with the powder falling port 56 and the powder inlet K3 opened on the cover plate 58. The flow divider 60 is in an inverted V shape, and the upper end of the flow divider 60 corresponds to the powder inlet K3, and the two sides respectively correspond to the two powder collection funnels 59, and is used to divide and guide the powder passing through the powder inlet K3 to the two powder collection funnels 59. The bottoms of the two powder collection funnels 59 are respectively communicated with the powder outlet pipe 61, and the powder outlet pipe 61 is used to export the metal powder in the powder collection funnel 59. The powder outlet pipe 61 can be a four-way pipe, including a horizontal pipe 62 and two vertical pipes 63. The two vertical pipes 63 are respectively vertically communicated with the horizontal pipe 62 and the bottoms of the two powder collection funnels 59. The metal powder collected by the powder collection funnel 59 can enter the horizontal pipe 62 through the corresponding vertical pipe 63 and be output along the horizontal pipe 62 through a conveying device (such as a blowing device, etc.). Optionally, a flow control device (such as a switch valve, a flow valve, etc.) can be provided on the powder outlet pipe 61 to control the on / off and flow rate of the powder outlet pipe 61.

[0072] Optionally, the powder collection assembly 14 further includes wheels 64 and a handle 65, so that the powder collection assembly 14 is in the form of a powder collection trolley, which is convenient for the powder collection assembly 14 to be pushed out of the powder cleaning device 100 for metal powder recovery.

[0073] In this embodiment, the control assembly 13 can control the vibration parameters of the vibration assembly 12 based on the position parameters of the movable platform 11. Among them, the position parameters include the flipping angle, and the flipping angle is the angle by which the bearing surface P1 rotates around the second axis L2 during the process of moving from the initial state to the current state. The vibration parameters include the vibration frequency. For example, after the encoder 41 of the flipping assembly 37 detects the flipping angle, the flipping angle information can be transmitted to the control assembly 13. After receiving the flipping angle information, the control assembly 13 determines the corresponding vibration frequency according to the flipping angle and controls the vibration assembly 12 to operate at this vibration frequency.

[0074] The vibration assembly 12 can be a pneumatic hammer or other vibration devices.

[0075] This embodiment provides a powder cleaning method, which is based on the aforementioned powder cleaning device 100 and is used for cleaning the printed part 200.

[0076] The powder cleaning method includes the following steps: Step 1: Rotate the flipping component 37 around the second axis L2 at a set speed (such as angular velocity w1) to flip the printed part 200 from 0° to 90°. During this process, simultaneously drive the printed part 200 to rotate around the first axis L1 at a set speed (such as angular velocity w2) by the rotating component 38, and control the vibration component 12 to vibrate at the first frequency; Step 2: After Step 1 is completed, flip the printed part 200 from 90° to the maximum flipping angle. At the same time, drive the printed part 200 to rotate around the first axis L1 by the rotating component 38, and control the vibration component 12 to vibrate at the second frequency. Specifically, when the flipping angle detected by the encoder 41 reaches 90°, the control component 13 controls the vibration component 12 to switch from the first frequency to the second frequency according to the flipping angle signal.

[0077] Among them, the maximum flipping angle is greater than 90° and less than 180°, for example, it can be 160°. The angular velocity w1 can be set to be relatively small, for example, the angular velocity w1 is less than 10° / minute, so that the printed part 200 can be flipped slowly to ensure that the printed part 200 can be powdered more fully at different flipping angles. The angular velocity w2 can be set to be relatively large, such as the angular velocity w2 is greater than 60° / minute.

[0078] Optionally, after Step 2, the powder cleaning method may further include Step 3.

[0079] Step 3 is: Keep the printed part 200 at the maximum flipping angle, drive the printed part 200 to rotate around the first axis L1 by the rotating component 38, and make the vibration component 12 operate at the third frequency for a set time (such as 20 minutes); the third frequency is greater than the second frequency.

[0080] In an embodiment, the printed part 200 is a printed part 200 with a number of microchannels K2 (see Figure 1 ) printed by an SLM type 3D printing device from stainless steel powder. The microchannel K2 here refers to a flow channel with a relatively small pore diameter, such as a pore channel K1 with a diameter less than 1 mm. Inside the slender microchannel K2, in addition to the metal powder particles 71 loosely remaining in the microchannel K2 during the printing process, there are also some semi-sintered metal powders adhered to the pore surface P2 of the microchannel K2, and some of these adhesive metal powders will aggregate into larger powder agglomerates 72.

[0081] When performing Step 1, refer to Figure 13, the unadhered metal powder particles 71 in the microchannel K2 are gradually cleared out of the microchannel K2, but the powder agglomerates 72 adhered to the pore surface P2 of the microchannel K2 will not or will less fall off from the pore surface P2 of the microchannel K2 and still remain adhered to the pore surface P2 of the microchannel K2 in a dispersed state. That is, the larger-sized powder agglomerates 72 will not fall off in large quantities, so they will not aggregate under the vibration at the first frequency and cause jamming at certain positions in the microchannel K2. For the stainless steel powder printed part of this embodiment, the first frequency can be set at 30 - 36 VPM (i.e., vibrate 30 - 36 times per minute), such as 30 VPM, 33 VPM, 36 VPM.

[0082] After step one is completed, step two is carried out, which can make the adhesive powder agglomerates 72 fall off from the pore surface P2 of the microchannel K2. Refer to Figure 14 , since the unadhered metal powder particles 71 in the microchannel K2 have been discharged from the microchannel K2 in step one, the whole microchannel K2 is relatively empty. After the powder agglomerates 72 are vibrated away from the pore surface P2 of the microchannel K2, they can be discharged from the microchannel K2 unobstructed and are not likely to accumulate during vibration and cause blockage of the microchannel K2, ensuring the powder cleaning effect. For the stainless steel powder printed part of this embodiment, the second frequency can be 42 - 43 VPM, such as 42 VPM, 42.5 VPM, 43 VPM.

[0083] In some cases, there may be a small amount of powder agglomerates 72 with relatively tight adhesion. By vibrating at a higher vibration frequency (the third frequency) in step three, these powder agglomerates 72 can be effectively removed, further ensuring the powder cleaning effect. For the stainless steel powder printed part of this embodiment, the third frequency can be above 45 VPM, for example, 45 - 50 VPM, such as 45 VPM, 45.5 VPM, 48 VPM, 50 VPM.

[0084] In contrast, for some known powder cleaning modes, the set vibration frequency is relatively low, and the adhered powder agglomerates 72 cannot be made to fall off. For other known powder cleaning modes, the set vibration frequency is relatively high, which may cause more large-sized powder agglomerates 72 to fall off before the loose metal powder particles 71 have fully flowed out of the microchannel K2 (see Figure 15 ). Due to 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 may aggregate at the larger bends of the microchannel K2 (see Figure 16), since the shapes of these powder agglomerates 72 are likely to be irregular rather than spherical like the non-metallic powder particles 71, their fluidity is very poor. When a large number of powder agglomerates 72 approach and aggregate with each other, these powder agglomerates 72 may be hooked and fitted together, thus getting stuck at some specific positions (such as bends) in the microchannel K2, hindering the subsequent non-metallic powder particles 71 from pouring out of the microchannel K2. In this regard, the known technology tends to choose powder cleaning methods other than vibration to solve this problem, such as pickling, electrolytic polishing, etc. However, although pickling, electrolytic polishing, etc. can clean the powder more thoroughly, they will damage the surface of the microchannel K2 of the printed part 200 and may also cause the size of the microchannel K2 to become larger, affecting the dimensional accuracy of the printed part 200.

[0085] Adopting the solution of this embodiment can well solve and avoid the problems of the known solutions, and the powder cleaning effect can be guaranteed.

[0086] With reference to Figure 17 , in another embodiment, the powder cleaning method further includes powder cleaning mode selection. In this powder cleaning method, after the powder cleaning device 100 is powered on, powder cleaning mode selection can be performed, and the powder cleaning modes include a manual mode and an automatic mode.

[0087] If the user selects the manual mode, the flipping angle and the rotation angle can be manually controlled, and the vibration frequency can be manually switched at the same time. The manual mode has greater flexibility. By combining flipping at a suitable angle and rotation speed and maintaining vibration at a suitable frequency (such as the third frequency), a better powder cleaning effect can also be achieved.

[0088] If the user selects the automatic mode, the aforementioned steps one, two, and three are executed in sequence.

[0089] In some embodiments, the switching timing of steps one, two, and three can also be jointly determined by the powder cleaning time condition and the flipping angle condition.

[0090] For example Figure 17 , after selecting the automatic mode, the movement duration of the printed part 200 is judged.

[0091] If the movement duration is less than or equal to 10 minutes, the flipping angle judgment is performed. If the flipping angle is less than or equal to 90°, step one is executed and run at the first frequency; after the flipping angle is greater than 90°, step two is executed and run at the second frequency.

[0092] After the movement duration is greater than 10 minutes, it runs at the third frequency and step three is executed. The execution time of step three can be 20 minutes to ensure the powder cleaning effect.

[0093] In summary, the purifying device 100 and the purifying method of this embodiment have a better purifying effect and can well handle the purifying of the printed part 200 with the microchannel K2.

[0094] In addition, in this embodiment, the rotary drive assembly 47 of the purifying device 100 is arranged outside the purifying chamber 15. When purifying, metal powder is not likely to enter the inside of the rotary drive assembly 47 and affect the function of the rotary drive assembly 47. Both the rotary drive assembly 47 and the powder collecting assembly 14 are arranged outside the purifying chamber 15, without occupying the internal space of the purifying chamber 15, so that the internal space of the purifying chamber 15 can be fully used to accommodate the printed part 200 to be purified.

[0095] The above embodiments are only used to illustrate the technical solutions of the present application and not to limit them. Although the present application has been described in detail with reference to the above preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present application can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present application.

Claims

1. A powder cleaning device for cleaning the powder on the printed parts obtained by SLM metal 3D printing, characterized in that, The powder cleaning device comprises: frame; A movable platform, movably disposed on the frame, for carrying the printed piece and driving the printed piece to move; a vibration component, mounted on the movable platform, and used to drive the printed part to vibrate through the movable platform; and A control component is communicatively connected to 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.

2. The powder cleaning device according to claim 1, characterized in that: The movable platform includes a flip assembly and a rotation assembly; The rotating assembly includes a bearing surface, and the bearing surface is used to bear and fix the printed part; the rotating assembly can drive the printed part to rotate around a first axis; wherein the first axis is perpendicular to the bearing surface; The rotating assembly is installed on the flip assembly and can rotate 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 in a horizontal state; The position parameter includes a flip angle, and the flip angle is an angle at which the bearing surface rotates around the second axis during the process of moving from an initial state to a current state; The vibration parameters include vibration frequency; During the process of the flip angle changing from 0° to 90°, the control component is used to control the vibration component to vibrate at a first frequency; during the process of the flip angle changing from 90° to the 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°.

3. The powder cleaning device according to claim 2, characterized in that: The flip assembly includes a flip drive assembly, a flip frame and an encoder; The flip driving component is connected to the flip frame in a transmission manner 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 component, and when the flip angle detected by the encoder reaches 90°, the control component controls the vibration component to switch from the first frequency to the second frequency; The flip frame is provided with a first follower; The powder cleaning device further comprises a first detection member, a second detection member and a third detection member, which are respectively connected to the control assembly for communication; the first detection member, the second detection member and the third detection member are spaced apart and 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 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.

4. The powder cleaning device according to claim 3 is characterized in that: The rotating assembly includes a bearing plate and a rotation driving assembly; The bearing plate is rotatably mounted on the flipping frame, and the rotation driving assembly is in transmission connection with the bearing plate for driving the bearing plate to rotate around the first axis; the bearing surface is the upper surface of the bearing plate; The flipping frame is fixedly connected with a fourth detection member, and the bearing plate is fixed with a second follower; The fourth detection member is located at the position where the second follower is located when the bearing plate rotates to zero, and is used for zero calibration of the bearing plate.

5. The purifying device according to claim 3, wherein: The machine frame includes a purifying chamber, and the purifying chamber is a sealed chamber body; Bearing seats are respectively installed outside the two side cabin walls on both sides of the purifying chamber in the horizontal direction. Both sides of the flipping frame are respectively connected with flipping shaft members, and the two flipping shaft members respectively pass through the two side cabin walls and are rotatably supported on the two bearing seats; The flipping driving assembly is in transmission connection with one of the flipping shaft members for driving the flipping frame to flip through the flipping shaft member.

6. The purifying device according to claim 5, wherein: The purifying device further includes a powder collecting assembly; The machine frame further includes a second chamber, a third chamber and a fourth chamber; The second chamber is located on one side of the purifying chamber in the horizontal direction and is used for accommodating the flipping driving assembly; The third chamber is located directly below the purifying chamber and is used for accommodating the powder collecting assembly; The powder collecting assembly is communicated with the bottom wall of the purifying chamber and is used for collecting the powder cleared from the purifying chamber; The fourth chamber is arranged below the second chamber and is used for accommodating the control assembly.

7. The purifying device according to claim 6, wherein: The bottom wall of the purifying chamber is in a funnel shape, and a powder dropping port is opened 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 shunting member 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 is communicated with the powder dropping port and the powder inlet opening formed on the cover plate; The shunting member is in an inverted V shape, and the upper end of the shunting member corresponds to the powder inlet opening, and both sides respectively correspond to the two powder collecting funnels, and is used for shunting and guiding the powder passing through the powder inlet opening to the two powder collecting funnels; The bottom ends of the two powder collecting funnels are respectively communicated with the powder outlet pipe, and the powder outlet pipe is used for discharging the powder in the powder collecting funnels.

8. A method for purifying flour, characterized in that, Based on the purifying device according to any one of claims 2-7, the purifying method includes: Rotating the printed part by the flipping assembly around the second axis at a set speed, flipping the printed part from 0° to 90°, and at the same time, driving the printed part to rotate around the first axis by the rotating assembly and controlling the vibration assembly to vibrate at a first frequency; Then, flipping the printed part from 90° to the maximum flipping angle, the maximum flipping angle being greater than 90°, and at the same time, driving the printed part to rotate around the first axis by the rotating assembly and controlling the vibration assembly to vibrate at a second frequency.

9. The purifying method according to claim 8, wherein: The powder cleaning method further includes: keeping the printed part at the maximum flipping angle, driving the printed part to rotate around the first axis by the rotating component, and operating the vibration component at a third frequency for a set time; the third frequency is greater than the second frequency.

10. The powder cleaning method according to claim 9, wherein: The printed part is a printed part with a plurality of microchannels printed by an SLM type 3D printing device from stainless steel powder; The first frequency is 30 - 36 VPM, the second frequency is 42 - 43 VPM, and the third frequency is greater than 45 VPM; When the vibration component operates at the first frequency, the loose metal powder particles in the microchannels can flow out of the microchannels; When the vibration component operates at the second frequency, the adhesive powder agglomerates attached to the pore surfaces of the microchannels can fall off from the printed part and flow out of the microchannels.

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