Metal powder feeding mechanism for 3D printing

Abstract

The invention relates to the technical field of selective laser melting, and discloses a metal powder feeding mechanism for 3D printing, the metal powder feeding mechanism comprises a forming driving module mounted in a processing bin, the output end of the forming driving module is rotationally connected with a processing base plate through an elastic rotating part, and a conveying mechanism for collecting powder is arranged at the bottom of the processing bin; a swinging powder collecting assembly for collecting powder shaken off by rotation of the machining base plate is installed outside the forming driving module, and the swinging powder collecting assembly and the machining base plate synchronously move through a swinging synchronous assembly. A brand-new metal powder feeding structure is arranged on the basis of gas-driven vertical blowing of the machining base plate for inclined filtering, powder discharging, powder filtering and powder feeding are integrated, the equipment size is reduced, meanwhile, overturning of the bowl-shaped filtering cover is achieved through the inclined kinetic energy of the machining base plate, procedure fusion is achieved, meanwhile, an additional filtering power source is not needed, and the equipment cost is reduced. And the problem of filtration and accumulation of large-volume powder is solved in a small space range.

Description

Technical Field

[0001] The invention relates to the technical field of selective laser melting, in particular to a metal powder feeding mechanism for 3D printing. Background Art

[0002] Selective laser melting is to slice the CAD model into a series of cross sections, and then the laser beam selectively melts the metal powder according to these cross-sectional data, and accumulates layer by layer until a complete part is formed. The equipment contains two processing pools and a powder pool. The powder pool rises in equal amounts one by one, and a powder distributor is used to move a thin layer of powder on the surface to the processing pool. The laser above the processing pool selectively melts the powder below. The processing pool continues to settle during the processing process, so that the surface continues to form a flat sand surface. After the workpiece is completed, the top of the workpiece is buried in the area filled with powder. After the workpiece is lifted, the powder on the surface can be removed.

[0003] Since there is a large amount of residual powder in the processing pool, the main means of powder feeding the powder pool is to collect the unmelted powder in the processing pool in the form of negative pressure, filter the powder, remove the molten residue, and obtain clean metal powder to be transported to the powder pool. Due to the heavy metal powder in the powder extraction process, a high-power negative pressure force is required to overcome the gravity of the metal powder for absorption, and it is applied to the filtering equipment and conveying equipment. The residual powder amount in the processing pool increases with the reduction of the workpiece volume. Since the volume of the processing pool is fixed, the amount of residual powder after processing is large, and the influence of residual powder on the workpiece will also appear, requiring subsequent powder blowing treatment. At the same time, an external vibration source needs to be added during the filtration process to provide kinetic energy for filtration, so that the powder shakes on the vibrating screen, so that the powder fully contacts the filtering surface, increasing energy consumption. Summary of the invention

[0004] The object of the present invention is to provide a metal powder feeding mechanism for 3D printing to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A metal powder feeding mechanism for 3D printing, comprising a forming drive module installed in a processing chamber, wherein the output end of the forming drive module is rotatably connected to a processing substrate through an elastic rotating member, a conveying mechanism for collecting powder is provided at the bottom of the processing chamber, and a swinging powder collecting component for collecting powder shaken off by the processing substrate is installed outside the forming drive module, and the swinging powder collecting component and the processing substrate move synchronously through a swinging synchronization component;

[0007] The swinging powder collecting assembly includes a bowl-shaped filter cover and a fixed ring plate. The bottom of the bowl-shaped filter cover has a circular hole for accommodating the fixed ring plate. The fixed ring plate is fixedly connected to the forming drive module. The fixed ring plate and the bowl-shaped filter cover are rotatably connected via a rotating shaft. The axial direction of the rotating shaft is consistent with the axial direction of the elastic rotating part. The bowl-shaped filter cover and the fixed ring plate are sealed by a bottom sealing soft sleeve. The top of the bowl-shaped filter cover and the wide end of the processing chamber are sealed by a top sealing soft sleeve.

[0008] As a further solution of the present invention: the swing synchronization component includes an active arc piston rod, a connecting hose, and a transmission arc piston rod. The active arc piston rod is installed between the molding drive module and the processing substrate, and the connecting hose is installed between the bowl-shaped filter cover and the molding drive module. The number of the swing synchronization components is two, which are symmetrically distributed on both sides of the molding drive module. The active arc piston rod is connected to the transmission arc piston rod directly below through the connecting hose.

[0009] As a further solution of the present invention: the number of the swing synchronization components is two, which are symmetrically distributed on both sides of the forming drive module, and the active arc piston rod is connected to the transmission arc piston rod at the lower side of the other side through the connecting hose.

[0010] As a further solution of the present invention: a tube cavity is provided on the outside of the swing powder collecting assembly, the top of the tube cavity is an open structure, and the bending margin of the connecting hose generated when the processing substrate descends is stored in the tube cavity.

[0011] As a further solution of the present invention: the bottom end of the connecting hose is fixedly connected to an arc-shaped support plate, and the tube cavity is slidably connected to a gravity ring. When the processing substrate rises to a limit height, the gravity ring is located inside the arc-shaped support plate.

[0012] As a further solution of the present invention: the sliding portion of the active arc-shaped piston rod, the sliding portion of the transmission arc-shaped piston rod, the top end of the connecting hose and the open portion of the top of the tube cavity are all sealed and connected by a soft sleeve.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] The present invention sets a new metal powder feeding structure on the basis of the inclined filtering of the air-driven vertical blowing processing substrate, realizes the integration of powder discharge, powder filtering and powder feeding, reduces the volume of the equipment, and uses the tilting kinetic energy of the processing substrate to realize the flipping of the bowl-shaped filter cover, which is as follows:

[0015] 1. A large amount of powder on the top of the processing substrate will be quickly dumped through the lower end of the processing substrate, and the concentrated distribution of powder is not conducive to filtering. Therefore, the bowl-shaped filter cover that receives the powder dumping end is high, and a large amount of powder will quickly slide from the high point to the low point of the bowl-shaped filter cover under the influence of gravity, so that the powder is quickly filtered, thereby realizing the powder spreading. In the process of moving from the high point to the low point of the bowl-shaped filter cover, the volume of powder reaching the low point of the bowl-shaped filter cover is reduced. Conversely, when the processing substrate rotates in the opposite direction, the powder at the low point of the fixed ring plate is lifted and slides to the other side for filtration, thereby forming repeated filtration movements. When the workpiece is blown multiple times to ensure cleanliness, and under the action of the gas pressure vertically downward, when the workpiece is blown clean, the powder is also filtered and collected.

[0016] 2. Since the elastic rotating part is provided with a reset spring to promote the resetting of the processing substrate, when the active arc piston rod is connected to the transmission arc piston rod on the other side through a connecting hose, the situation shown in the figure will occur. At this time, the movement direction of the bowl-shaped filter cover is consistent with the active arc piston rod. The advantage of this process is that the powder accumulates at the low point of the bowl-shaped filter cover. When the gas blowing the processing substrate is turned off, the spring of the elastic rotating part promotes the resetting of the processing substrate, and the bowl-shaped filter cover is quickly reset to the horizontal state, so that the bowl-shaped filter cover can lift the powder at the lower end and drop it to the bowl-shaped filter cover. During this period, no gas does work, so that the powder can pass through the bowl-shaped filter cover more quickly and smoothly.

[0017] In summary, the present invention not only realizes process integration, but also solves the problem of filtering and stacking of large amounts of powder in a small space without the need for an additional filtering power source. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0019] Figure 1 A schematic diagram of the initial stage of a metal powder feeding mechanism for 3D printing;

[0020] Figure 2 A schematic diagram of the powder dropping stage of a metal powder feeding mechanism for 3D printing;

[0021] Figure 3 It is a schematic diagram of the rotation of a processing substrate under the action of vertical deflection wind pressure and the same-direction rotation of a swing powder collecting component in a metal powder feeding mechanism for 3D printing;

[0022] Figure 4A schematic diagram of the rotation of a processing substrate in a metal powder feeding mechanism for 3D printing under the action of vertical deflection wind pressure and the reverse rotation of a swing powder collecting component;

[0023] Figure 5 for Figure 1 The enlarged schematic diagram of the middle A part;

[0024] In the figure: 100, processing substrate; 200, elastic rotating part; 300, conveying mechanism; 400, forming drive module; 500, swing synchronization component; 1, active arc piston rod; 2, connecting hose; 21, arc support plate; 22, gravity ring; 3, transmission arc piston rod; 4, swing powder collecting component; 41, bowl-shaped filter cover; 42, fixed ring plate; 43, top closed soft sleeve; 44, bottom closed soft sleeve; 5, through the tube cavity. DETAILED DESCRIPTION

[0025] See also Figure 1-Figure 5 : In this embodiment: it includes a molding drive module 400 installed in a processing chamber, wherein the output end of the molding drive module 400 is rotatably connected to a processing substrate 100 via an elastic rotating member 200, a conveying mechanism 300 for collecting powder is provided at the bottom of the processing chamber, and a swinging powder collecting component 4 for collecting powder shaken off by the rotating processing substrate 100 is installed on the outside of the molding drive module 400, and the swinging powder collecting component 4 and the processing substrate 100 move synchronously via a swinging synchronization component 500.

[0026] In this embodiment: Figure 1 The dotted part of the middle left figure is a processing chamber, and a processing pool is formed between the processing substrate 100 and the receiving cavity at the top of the processing chamber. The lower part of the processing chamber is an open powder discharge chamber, and a matrix blowing module is arranged on the top of the processing chamber. The blowing module has a plurality of exhaust holes distributed in a matrix. The exhaust holes in the area on one side of the elastic rotating member 200 are opened once. Under the action of strong wind force, the processing substrate 100 is offset, so that the powder quickly falls through the bottom end of the processing substrate 100 to the inside of the swing powder collecting component 4. At this time, the swing synchronization component 500 transmits the rotation execution action of the processing substrate 100 to the swing powder collecting component 4. In this stage, the swing powder collecting assembly 4 is tilted synchronously, so that the powder enters the inside of the swing powder collecting assembly 4. In order to blow clean the workpiece on the processing substrate 100, the swing powder collecting assembly 4 is swung left and right along with the processing substrate 100 by continuously switching directions, so that the powder slides in the swing powder collecting assembly 4, so that the powder continuously passes through the filter holes, which promotes the powder to fall. Under the action of wind, the speed and efficiency of the particles passing through the holes can be accelerated. The falling powder is transported to the powder bin through the conveying mechanism 300, thereby realizing the integrated powder discharge, filtering and powder feeding actions and completing the powder feeding process.

[0027] In this embodiment: the swing powder collecting assembly 4 includes a bowl-shaped filter cover 41 and a fixed ring plate 42. The bottom of the bowl-shaped filter cover 41 has a circular hole for accommodating the fixed ring plate 42. The fixed ring plate 42 is fixedly connected to the forming drive module 400. The fixed ring plate 42 and the bowl-shaped filter cover 41 are rotatably connected via a rotating shaft. The axial direction of the rotating shaft is consistent with the axial direction of the elastic rotating member 200. The bowl-shaped filter cover 41 and the fixed ring plate 42 are closed by a bottom sealing soft sleeve 44. The top of the bowl-shaped filter cover 41 and the wide end of the processing chamber are closed by a top sealing soft sleeve 43.

[0028] In this embodiment: Please refer to Figure 1-Figure 4 The shape of the bowl-shaped filter cover 41 is consistent with the bowl shape, but a circular hole is opened at the bottom of the bowl-shaped filter cover 41, and the fixed ring plate 42 is fixed at the molding drive module 400, or the fixed ring plate 42 can be fixed on the outside of the swing synchronization component 500, and the fixed ring plate 42 is concentrically arranged with the bottom hole of the bowl-shaped filter cover 41, and the diameter of the circular hole is larger than the diameter of the fixed ring plate 42, and the bowl-shaped filter cover 41 and the fixed ring plate 42 are closed by a bottom sealing soft sleeve 44, and the bowl-shaped filter cover 41 and the fixed ring plate 42 are connected by a rotating shaft. After the rotating shaft is connected, the relative rotation direction of the bowl-shaped filter cover 41 and the fixed ring plate 42 is consistent with the rotation direction of the processing substrate 100, thereby paving the way for subsequent synchronous swinging, and the bowl mouth diameter of the bowl-shaped filter cover 41 is smaller than the wide end diameter of the processing chamber, so the bowl-shaped filter cover 41 and the wide end of the processing chamber are closed by a top sealing soft sleeve 43. When the bowl-shaped filter cover 41 swings left and right, the top sealing soft cover 43 and the bottom sealing soft cover 44 complete the elastic sealing operation of the dynamic gap through expansion and contraction.

[0029] In this embodiment: the swing synchronization component 500 includes an active arc piston rod 1, a connecting hose 2, and a transmission arc piston rod 3. The active arc piston rod 1 is installed between the molding drive module 400 and the processing substrate 100, and the connecting hose 2 is installed between the bowl-shaped filter cover 41 and the molding drive module 400. There are two swing synchronization components 500, which are symmetrically distributed on both sides of the molding drive module 400. The active arc piston rod 1 is connected to the transmission arc piston rod 3 directly below through the connecting hose 2.

[0030] In this embodiment: the active arc piston rod 1 and the transmission arc piston rod 3 are both sleeve rod structures, the sliding rod is a solid arc rod and is equipped with a piston, the sleeve rod has an air cavity inside, and is equipped with an air chamber that slides with the piston. After the active arc piston rod 1 and the transmission arc piston rod 3 are closed, the inward movement of the piston in the active arc piston rod 1 will cause the piston of the transmission arc piston rod 3 to move outward. Therefore, when the active arc piston rod 1 and the transmission arc piston rod 3 facing each other in the vertical direction are connected, during the descent of the processing substrate 100, the bowl-shaped filter cover 41 corresponding to the processing substrate 100 directly below is lifted. The advantage of this is that a large amount of powder on the top of the processing substrate 100 will be quickly dumped through the lower end of the processing substrate 100, and the concentrated distribution of the powder is not conducive to filtering, so the bowl-shaped filter cover 41 at the end receiving the powder dumping is lifted. The high position, a large amount of powder will quickly slide from the high point to the low point of the bowl-shaped filter cover 41 under the influence of gravity, so that the powder is quickly filtered, thereby achieving powder flattening. In the process of moving from the high point to the low point of the bowl-shaped filter cover 41, the volume of powder reaching the low point of the bowl-shaped filter cover 41 is reduced. On the contrary, when the processing substrate 100 rotates in the opposite direction, the powder at the low point of the fixed ring plate 42 is lifted and slides to the other side for filtering, thereby forming a repeated filtering movement. Under the condition that the workpiece is blown multiple times to ensure cleanliness, and under the action of the gas pressure vertically downward, when the workpiece is blown clean, the powder is also filtered and collected. The powder feeding mechanism is integrated with the processing bin, which reduces the volume of the equipment and integrates the powder feeding process with the powder discharge process, simplifies the process, and reduces the additional kinetic energy driving the filter plate to vibrate.

[0031] In this embodiment, there are two swing synchronization components 500 symmetrically distributed on both sides of the forming drive module 400 , and the active arc piston rod 1 is connected to the transmission arc piston rod 3 at the lower side of the other side through a connecting hose 2 .

[0032] In this embodiment, since the elastic rotating member 200 is provided with a reset spring to facilitate the reset of the processed substrate 100, when the active arc piston rod 1 is connected to the transmission arc piston rod 3 at the lower side of the other side through the connecting hose 2, there will be Figure 4 The bowl-shaped filter cover 41 moves in the same direction as the active arc piston rod 1. The advantage of this process is that the powder accumulates at the low point of the bowl-shaped filter cover 41. When the gas blowing the processing substrate 100 is closed, the spring of the elastic rotating part 200 promotes the reset of the processing substrate 100, and the bowl-shaped filter cover 41 also quickly resets to the horizontal position, so that the bowl-shaped filter cover 41 can lift the powder at the lower end and drop it at the bowl-shaped filter cover 41. During this period, no gas does work, so that the powder can pass through the bowl-shaped filter cover 41 more quickly and smoothly.

[0033] In this embodiment: a tube cavity 5 is provided outside the swing powder collecting assembly 4 , and the top of the tube cavity 5 is an open structure. The bending margin of the connecting hose 2 generated when the processing substrate 100 descends is stored in the tube cavity 5 .

[0034] In this embodiment: the advantage of using a connecting hose 2 is that there is no need to consider the displacement difference between the processing substrate 100 and the swinging powder collecting assembly 4, but there is a problem of storing the remaining pipe volume, so a through-tube cavity 5 is set, and when the molding drive module 400 controls the active arc piston rod 1 and the swinging powder collecting assembly 4 to cause relative displacement, the remaining pipe volume is stored in the through-tube cavity 5.

[0035] In this embodiment: the bottom end of the connecting hose 2 is fixedly connected to an arc-shaped support plate 21 , and a gravity ring 22 is slidably connected in the tube cavity 5 . When the processing substrate 100 rises to the limit height, the gravity ring 22 is located inside the arc-shaped support plate 21 .

[0036] In this embodiment: In order to prevent the curved connecting hose 2 from occupying other areas, a gravity ring 22 is provided. When the processing substrate 100 is lifted, the gravity ring 22 acts on the arc support plate 21 to make the connecting hose 2 in a stretched state. Since the connecting hose 2 is only connected to the fixed sleeve part of the active arc piston rod 1, it will not affect the movement of the active arc piston rod 1. When the active arc piston rod 1 descends, it is affected by gravity, and the gravity ring 22 drives the curved connecting hose 2 to descend to the inside of the tube cavity 5, and the pipeline is always in a stretched state.

[0037] In this embodiment, the sliding part of the active arc piston rod 1, the sliding part of the transmission arc piston rod 3, the top of the connecting hose 2 and the open part of the top of the tube cavity 5 are all sealed and connected through a soft sleeve. The sealing structure can prevent powder from entering the sliding gap and causing sliding wear problems.

[0038] What is described above is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A metal powder feeding mechanism for 3D printing, comprising a forming drive module (400) installed in a processing chamber, wherein the output end of the forming drive module (400) is rotatably connected to a processing substrate (100) via an elastic rotating member (200), and a conveying mechanism (300) for collecting powder is provided at the bottom of the processing chamber, characterized in that: The outside of the molding drive module (400) is provided with a swing powder collecting component (4) for collecting powder shaken off by the processing substrate (100) during rotation, and the swing powder collecting component (4) and the processing substrate (100) move synchronously via a swing synchronization component (500); The swing powder collecting assembly (4) comprises a bowl-shaped filter cover (41) and a fixed ring plate (42). The bottom of the bowl-shaped filter cover (41) has a circular hole for accommodating the fixed ring plate (42). The fixed ring plate (42) is fixedly connected to the forming drive module (400). The fixed ring plate (42) and the bowl-shaped filter cover (41) are rotatably connected via a rotating shaft. The axial direction of the rotating shaft is consistent with the axial direction of the elastic rotating member (200). The bowl-shaped filter cover (41) and the fixed ring plate (42) are sealed by a bottom sealing soft sleeve (44). The top end of the bowl-shaped filter cover (41) and the wide end of the processing chamber are sealed by a top sealing soft sleeve (43).

2. A metal powder feeding mechanism for 3D printing according to claim 1, characterized in that: The swing synchronization component (500) comprises an active arc piston rod (1), a connecting hose (2), and a transmission arc piston rod (3); the active arc piston rod (1) is installed between the molding drive module (400) and the processing substrate (100); the connecting hose (2) is installed between the bowl-shaped filter cover (41) and the molding drive module (400); the number of the swing synchronization components (500) is two, which are symmetrically distributed on both sides of the molding drive module (400); the active arc piston rod (1) is connected to the transmission arc piston rod (3) directly below through the connecting hose (2).

3. A metal powder feeding mechanism for 3D printing according to claim 2, characterized in that: The number of the swing synchronization components (500) is two, which are symmetrically distributed on both sides of the forming drive module (400), and the active arc piston rod (1) is connected to the transmission arc piston rod (3) below the other side through the connecting hose (2).

4. A metal powder feeding mechanism for 3D printing according to claim 3, characterized in that: The outside of the swing powder collecting assembly (4) is provided with a tube cavity (5), the top of the tube cavity (5) is an open structure, and the bending margin of the connecting hose (2) generated when the processing substrate (100) descends is stored in the tube cavity (5).

5. The metal powder feeding mechanism for 3D printing according to claim 2, characterized in that: The bottom end of the connecting hose (2) is fixedly connected to an arc-shaped support plate (21), and the inside of the tube cavity (5) is slidably connected to a gravity ring (22). When the processing substrate (100) rises to a maximum height, the gravity ring (22) is located inside the arc-shaped support plate (21).

6. A metal powder feeding mechanism for 3D printing according to claim 4, characterized in that: The sliding portion of the active arc-shaped piston rod (1), the sliding portion of the transmission arc-shaped piston rod (3), the top end of the connecting hose (2) and the open portion at the top of the tube cavity (5) are all sealed and connected via a soft sleeve.

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