Metal powder recovery structure for metal 3D printing equipment

Abstract

The invention belongs to the technical field of 3D printing metal powder recovery, and particularly relates to a metal powder recovery structure for metal 3D printing equipment, which comprises a machine body and a printing table arranged in the machine body, and further comprises a weighing mechanism arranged in the printing table, the weighing mechanism is used for weighing powder falling on the surface of the printing table in the printing process. And the moving mechanism is arranged on the inner side wall of the machine body, and the length direction of the moving mechanism is the same as the length direction of the printing table. The pushing and sweeping speed and force can be dynamically adjusted according to powder with different residual quantities, it is guaranteed that thick-layer powder is efficiently scattered and cleaned, thin-layer powder is not scattered, and friction loss of equipment is reduced; meanwhile, dust can be synchronously sucked in the printing and push-sweeping processes, and the situation that the dust diffuses and pollutes the interior of equipment is avoided; and the dust suction intensity can be matched in real time according to the push-broom speed, and finally the multiple benefits of high powder recovery rate, energy conservation and consumption reduction are achieved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of 3D printing metal powder recycling, and particularly relates to a metal powder recycling structure for a metal 3D printing device. BACKGROUND

[0002] In the metal 3D printing process, metal powder is used as a core consumable, and its utilization rate and recycling effect directly affect the printing cost and production continuity. A large amount of un-melted metal powder is left on the surface of the printing table of the metal 3D printing device. Such powder is not only the main object of recycling, but also the key source of subsequent powder reuse. Therefore, a powder recycling structure needs to be arranged inside the 3D printing device. For example, a metal 3D printing device powder recycling device disclosed in publication No. CN111036910A.

[0003] Currently, in the industry, the metal powder on the surface of the printing table is recycled by using the traditional method of rolling brush cleaning. The loose powder on the surface of the printing table is pushed to a designated recycling area (such as a powder collecting box) through the rotation of the rolling brush, and then collected by cooperating with auxiliary means such as negative pressure adsorption. However, the rotation speed of the rolling brush is fixed. When the amount of powder on the surface of the printing table is small, the rolling brush with fixed speed still rotates at a high speed, which may cause excessive cleaning. Moreover, the friction between the high-speed rotating rolling brush and the printing table surface is significantly increased, which not only accelerates the wear of the bristles of the rolling brush, shortens the service life of the rolling brush, but also may generate static electricity due to friction, so that the originally loose fine powder particles are adsorbed on the bristles or the surface of the printing table, thereby reducing the cleaning efficiency. In addition, the high-speed rotating rolling brush may also drive air flow disturbance, which may lift a large amount of powder on the surface of the printing table, further increasing the difficulty of subsequent cleaning.

[0004] Therefore, a metal powder recycling structure for a metal 3D printing device is provided. SUMMARY

[0005] The purpose of the present application is to provide a metal powder recycling structure for a metal 3D printing device to solve the above problems.

[0006] To achieve the above purpose, the following technical scheme is adopted: a metal powder recycling structure for a metal 3D printing device, comprising a machine body and a printing table arranged inside the machine body, further comprising: a weighing mechanism arranged inside the printing table, and the weighing mechanism is used for weighing the powder falling on the surface of the printing table during the printing process; a moving mechanism arranged on the inner side wall of the machine body, and the length direction of the moving mechanism is the same as the length direction of the printing table; A pushing and sweeping mechanism is arranged inside the printing table, one end of the pushing and sweeping mechanism is connected with the moving end of the moving mechanism, the pushing and sweeping mechanism is located on the upper surface of the weighing mechanism, and the pushing and sweeping mechanism is used for sweeping the powder on the surface of the weighing mechanism to one side; A powder collecting box is arranged inside the machine body, the powder collecting box is located on one side of the printing table, and the powder collecting box is used for collecting the powder swept on the surface of the printing table; A dust suction mechanism is arranged above the pushing and sweeping mechanism, one end of the dust suction mechanism is connected with the moving end of the moving mechanism, and the dust suction mechanism is used for sucking and processing the dust generated in the sweeping process; A speed detection mechanism is arranged between the moving end of the moving mechanism and one end of the pushing and sweeping mechanism, and the speed detection mechanism is used for detecting the rotating speed of the pushing and sweeping mechanism and adjusting the suction strength of the dust suction mechanism; A PLC controller is fixedly arranged on the side wall of the machine body, and the weighing mechanism, the moving mechanism, the dust suction mechanism and the speed detection mechanism are electrically connected with the PLC controller.

[0007] Preferably, the weighing mechanism comprises a weighing plate arranged inside the printing table, and two weighing sensors are symmetrically and fixedly arranged between the lower surface of the weighing plate and the inside of the printing table.

[0008] Preferably, the moving mechanism comprises an electric sliding rail fixedly arranged on the inner side wall of the machine body, and an electric sliding block is slidably arranged in the electric sliding rail.

[0009] Preferably, the pushing and sweeping mechanism comprises a rolling brush arranged inside the printing table, the bristles of the rolling brush are arranged in contact with the upper surface of the weighing plate, both ends of the rotating shaft of the rolling brush pass through both sides of the printing table, one end of the rotating shaft of the rolling brush is rotationally connected with the side wall of the electric sliding block, a gear is fixedly arranged at the end of the rolling brush away from the electric sliding block, a rack is fixedly arranged on the side wall of the printing table along the length direction, and the rack is arranged in meshing connection with the gear.

[0010] Preferably, the dust suction mechanism comprises a circular shell fixedly arranged on the side wall of the electric sliding block, the rotating shaft of the rolling brush passes through the inside of the circular shell, a first suction pipe is arranged above the rolling brush, one end of the first suction pipe is fixedly connected with the side wall of the circular shell, a plurality of suction holes are uniformly arranged on the pipe wall of the first suction pipe and face one side of the rolling brush, a suction box is fixedly arranged on the side wall of the machine body, a second suction pipe is fixedly arranged at the bottom of the suction box, one end of the second suction pipe away from the suction box extends to the inside of the machine body and is fixedly arranged with a telescopic corrugated pipe, one end of the telescopic corrugated pipe away from the second suction pipe is fixedly connected with the pipe wall of the first suction pipe, and a first gas switch valve is fixedly arranged on the pipe wall of the second suction pipe.

[0011] Preferably, a third suction tube extending into the body of the machine is fixedly provided on the top of the suction box. The third suction tube is located above the printing table, and a second gas switch valve is fixedly provided on the wall of the third suction tube.

[0012] Preferably, the speed detection mechanism includes an infrared sensor fixedly mounted on the inner wall of the circular shell, a fixing ring fixedly mounted on one end of the rotating shaft of the roller brush, and a plurality of evenly distributed reflective sheets fixedly mounted on the circumferential wall of the fixing ring, with the positions of the infrared sensor corresponding to the positions of the reflective sheets.

[0013] Preferably, the upper surface of the printing table has three adjacent sides that are raised upwards, and a strip-shaped opening is provided on the side of the printing table opposite to the raised side.

[0014] Compared with existing technologies, the advantages of this invention are as follows: 1. Through the setting of a weighing mechanism, a moving mechanism, and a sweeping mechanism, the weighing mechanism can capture the weight of residual powder on the printing table in real time after printing and transmit the weight signal to the PLC controller, providing the core basis for subsequent sweeping parameter adjustment; the moving mechanism serves as the power carrier of the sweeping mechanism, and the moving speed of its electric slider is intelligently controlled by the PLC controller according to the powder weight, directly determining the sweeping rhythm of the sweeping mechanism; the roller brush of the sweeping mechanism achieves counterclockwise rotation through gear and rack meshing, and pushes close to the table under the drive of the moving mechanism, and the moving and rotating speed of the roller brush dynamically changes with the powder weight. The cooperation of the three mechanisms ensures that powder of different residual weights can be thoroughly swept to the powder collection box, and avoids the problems of incomplete or excessive recovery caused by traditional fixed-speed sweeping.

[0015] 2. Through the dust extraction mechanism, during the printing stage, the dust extraction mechanism can actively extract the printing dust inside the machine body through the third suction tube, preventing dust spread and pollution from the source. During the cleaning stage, the dust extraction mechanism moves synchronously with the electric slider of the moving mechanism. When the moving mechanism drives the roller brush to push and sweep, the first suction tube of the dust extraction mechanism moves together with the electric slider. The suction hole on its tube wall is always aligned with the roller brush pushing and sweeping area. With the help of negative pressure, the fine dust generated by the pushing and sweeping is captured in real time and collected inside the suction box. This not only prevents dust from adhering to the surface of core components such as the weighing mechanism and cleaning mechanism, affecting the detection accuracy and pushing and sweeping effect, but also prevents dust from spreading into the machine body, ensuring the cleanliness of the subsequent printing environment.

[0016] 3. Through the set speed detection mechanism, the infrared sensor works in conjunction with the reflector on the rotating shaft of the roller brush to capture the rotation speed of the roller brush in real time. The faster the roller brush rotates, the higher the frequency of the pulse signal triggered by the reflector. After the speed detection mechanism transmits this signal to the PLC controller, the PLC controller will synchronously increase the suction intensity of the dust suction mechanism to capture a large amount of dust with stronger negative pressure. If the roller brush rotates slowly, the pulse signal frequency decreases, and the PLC controller will reduce the suction intensity. This avoids dust diffusion caused by "too much dust and insufficient suction" and also prevents energy waste caused by "too little dust and excessive suction". Attached Figure Description

[0017] Figure 1 This is a perspective view of a metal powder recycling structure for a metal 3D printing device provided by the present invention; Figure 2 This is a three-dimensional view of the body after being cut open in a metal powder recovery structure for a metal 3D printing device provided by the present invention. Figure 3 This is a perspective view of the weighing mechanism, moving mechanism, and sweeping mechanism in a metal powder recovery structure for a metal 3D printing device provided by the present invention. Figure 4 This is a perspective view of the weighing mechanism in a metal powder recovery structure for a metal 3D printing device provided by the present invention; Figure 5 This is a perspective view of the dust extraction mechanism in a metal powder recovery structure for a metal 3D printing device provided by the present invention. Figure 6 This is a perspective view of the speed detection mechanism in a metal powder recovery structure for a metal 3D printing device provided by the present invention.

[0018] In the diagram: 1. Machine body, 2. Printing table, 3. Weighing mechanism, 31. Weighing plate, 32. Weighing sensor, 4. Moving mechanism, 41. Electric slide rail, 42. Electric slider, 5. Push-brush mechanism, 51. Roller brush, 52. Gear, 53. Rack, 6. Dust collection box, 7. Dust suction mechanism, 71. Circular shell, 72. First suction pipe, 73. Suction hole, 74. Suction box, 75. Second suction pipe, 76. Telescopic corrugated pipe, 77. First gas switch valve, 78. Third suction pipe, 79. Second gas switch valve, 8. Speed ​​detection mechanism, 81. Infrared sensor, 82. Fixing ring, 83. Reflector, 9. PLC controller. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0020] like Figures 1-6As shown, a metal powder recovery structure for a metal 3D printing device includes a body 1 and a printing stage 2 disposed inside the body 1. The upper surface of the printing stage 2 has three adjacent sides that are raised upwards, and a strip-shaped opening is provided on the side of the printing stage 2 opposite to the raised side. This structure design can prevent the metal powder collected inside the printing stage 2 from overflowing to the edge. It also includes: Weighing mechanism 3 is located inside the printing table 2 and is used to weigh the powder that falls on the surface of the printing table 2 during the printing process. Weighing mechanism 3 includes a weighing plate 31 located inside the printing table 2. Two weighing sensors 32 are symmetrically fixed between the lower surface of the weighing plate 31 and the inside of the printing table 2. Annular flexible seals are provided at the gaps between the periphery of the weighing plate 31 and the inner wall of the printing table 2 to prevent metal powder from entering the gaps.

[0021] The moving mechanism 4 is disposed on the inner side wall of the machine body 1, and the length direction of the moving mechanism 4 is the same as the length direction of the printing table 2; the moving mechanism 4 includes an electric slide rail 41 fixedly disposed on the inner side wall of the machine body 1, and an electric slider 42 is slidably disposed inside the electric slide rail 41.

[0022] The sweeping mechanism 5 is located inside the printing table 2, and one end of the sweeping mechanism 5 is connected to the moving end of the moving mechanism 4. The sweeping mechanism 5 is located on the upper surface of the weighing mechanism 3 and is used to sweep the powder on the surface of the weighing mechanism 3 to one side. The sweeping mechanism 5 includes a roller brush 51 located inside the printing table 2, and the bristles of the roller brush 51 are in contact with the upper surface of the weighing plate 31. The rotating shafts at both ends of the roller brush 51 pass through both sides of the printing table 2, and one end of the rotating shaft of the roller brush 51 is rotatably connected to the side wall of the electric slider 42. A gear 52 is fixedly provided at the end of the roller brush 51 away from the electric slider 42. A rack 53 is fixedly provided along the length direction of the side wall of the printing table 2. The rack 53 is meshed with the gear 52 and is located above the gear 52. During the movement of the roller brush 51, the gear 52 at the other end of the roller brush 51 meshes with the rack 53, so that the roller brush 51 rotates counterclockwise during the movement.

[0023] The powder collection box 6 is located inside the machine body 1 and is situated on one side of the printing table 2. The powder collection box 6 is used to collect the powder after cleaning the surface of the printing table 2. The opening of the powder collection box 6 and the lower part near the weighing plate 31 are provided with a guide plate, which can guide the metal powder into the interior of the powder collection box 6.

[0024] A dust suction mechanism 7 is positioned above the sweeping mechanism 5, with one end connected to the moving end of the moving mechanism 4. The dust suction mechanism 7 is used to suction and process the dust generated during the sweeping process. The dust suction mechanism 7 includes a circular shell 71 fixedly mounted on the side wall of the electric slider 42. A rotating shaft at one end of the roller brush 51 passes through the interior of the circular shell 71. A first suction pipe 72 is located above the roller brush 51, with one end fixedly connected to the side wall of the circular shell 71. Multiple evenly distributed suction holes 73 are opened on the side of the first suction pipe 72 facing the roller brush 51. A suction box 74 is fixedly mounted on the side wall of the machine body 1. The suction box 74 contains a suction fan and a filter bag (not shown in the figure). The filter bag allows the dust to be suctioned and removed. The inhaled metal powder is filtered. Meanwhile, the side wall of the suction box 74 is provided with a door (not shown in the figure). The bottom of the suction box 74 is fixedly provided with a second suction pipe 75. The end of the second suction pipe 75 away from the suction box 74 extends into the interior of the machine body 1 and is fixedly provided with a telescopic corrugated pipe 76. The end of the telescopic corrugated pipe 76 away from the second suction pipe 75 is fixedly connected to the pipe wall of the first suction pipe 72. The telescopic corrugated pipe 76 can ensure the movement of the first suction pipe 72. The pipe wall of the second suction pipe 75 is fixedly provided with a first gas switch valve 77. The top of the suction box 74 is fixedly provided with a third suction pipe 78 extending into the interior of the machine body 1. The third suction pipe 78 is located above the printing table 2, and the pipe wall of the third suction pipe 78 is fixedly provided with a second gas switch valve 79.

[0025] The speed detection mechanism 8 is located between the moving end of the moving mechanism 4 and one end of the sweeping mechanism 5. The speed detection mechanism 8 is used to detect the rotation speed of the sweeping mechanism 5 and adjust the suction intensity of the dust suction mechanism 7. The speed detection mechanism 8 includes an infrared sensor 81 fixedly mounted on the inner wall of the circular shell 71. A fixed ring 82 is fixedly mounted on the rotating shaft of one end of the roller brush 51. A plurality of evenly distributed reflectors 83 are fixedly mounted on the circumferential wall of the fixed ring 82. The position of the infrared sensor 81 corresponds to the position of the reflectors 83. The detection end of the infrared sensor 81 continuously emits an infrared beam. When the plurality of reflectors 83 rotate with the fixed ring 82, they will sequentially block and conduct the beam of the infrared sensor 81.

[0026] The PLC controller 9 is fixedly installed on the side wall of the machine body 1. The weighing mechanism 3, the moving mechanism 4, the dust suction mechanism 7 and the speed detection mechanism 8 are all electrically connected to the PLC controller 9.

[0027] The operating principle of this invention is described as follows: The operator first opens the sealed door of the machine body 1 and places the workpiece to be printed stably on the surface of the weighing plate 31 inside the printing table 2. Then the sealed door is closed. After the equipment is started, the printing operation is performed through the 3D printing head (not shown in the figure) on the machine body 1. During this process, the operator starts the suction box 74 and opens the second gas switch valve 79 through the PLC controller 9 to keep the third suction pipe 78 unobstructed. With the strong effect of negative pressure adsorption, the metal dust generated inside the machine body 1 during printing is promptly sucked out, effectively avoiding the spread and pollution of dust inside the machine body 1. At the same time, the metal powder that is not completely melted during the printing process will naturally fall onto the surface of the weighing plate 31, preparing for subsequent recycling. After the printing job is completed, the staff stops the operation of the suction box 74 and closes the second gas switch valve 79 by instructing the PLC controller 9. Then, they manually open the sealing door, remove the printed workpiece from the weighing plate 31, and close the sealing door again. At this time, the weighing sensor 32 immediately weighs the weighing plate 31 and the metal powder remaining on its surface, and transmits the detected weight value to the PLC controller 9 in real time. The PLC controller 9 intelligently controls the horizontal movement of the electric slider 42 in the electric slide rail 41 according to the weight value. When the electric slider 42 moves, it drives the roller brush 51 to move horizontally on the surface of the weighing plate 31. The gear 52 at the other end of the roller brush 51 meshes with the rack 53, so that the roller brush 51 rotates counterclockwise during the movement. This ensures that the movement direction of the brush bristles at the bottom of the roller brush 51 is the same as the overall movement direction of the roller brush 51, so that the brush bristles of the roller brush 51 will generate a continuous "pushing force" in the direction of powder recovery, thereby improving the powder recovery effect on the weighing surface. If the metal powder is heavy, the PLC controller 9 will increase the moving speed of the electric slider 42 in the electric slide rail 41, thereby increasing the moving speed and rolling speed of the roller brush 51 on the surface of the weighing plate 31. The rapid movement and rotation can generate a stronger pushing force, which can efficiently disperse and push the thick layer of powder, avoiding incomplete pushing or jamming of the roller brush 51 due to excessive powder accumulation, ensuring that a large amount of powder can be quickly concentrated and pushed into the powder collection box 6, thus improving the recycling efficiency. If the metal powder is light, the PLC controller 9 reduces the moving speed of the electric slider 42, which slows down the moving and rotating speed of the roller brush 51 accordingly. This avoids the thin layer of powder from being disturbed and scattered due to excessive speed, and also reduces unnecessary friction between the roller brush 51 and the surface of the weighing plate 31, reducing equipment wear. At the same time, it ensures that even a small amount of powder can be thoroughly pushed and swept into the powder collection box 6. Finally, all powder is efficiently collected inside the powder collection box 6. While the PLC controller 9 starts the electric slider 42 to drive the roller brush 51 to perform the pushing and sweeping operation, it simultaneously starts the suction box 74 and opens the first gas switch valve 77, so that the first suction pipe 72, the second suction pipe 75 and the telescopic corrugated pipe 76 form a smooth negative pressure suction channel. After the suction box 74 is running, it will quickly extract the gas inside the first suction pipe 72, the second suction pipe 75 and the telescopic corrugated pipe 76, so that multiple suction holes 73 form a stable negative pressure. In this way, the small amount of dust and fine dust generated by the roller brush 51 in the process of pushing and sweeping the powder on the surface of the printing table 2 will be quickly sucked into the suction hole 73 by the negative pressure and transported to the suction box 74 for collection through the first suction pipe 72, the second suction pipe 75 and the telescopic corrugated pipe 76. This avoids the spread and pollution of dust inside the machine body 1 from the source, ensuring the cleanliness of the equipment and the stability of the subsequent printing environment. During the counterclockwise rotation and sweeping process of the roller brush 51, the rotating shaft at one end will synchronously drive the fixed ring 82 and multiple reflectors 83 to rotate together. The detection end of the infrared sensor 81 continuously emits an infrared beam. When the multiple reflectors 83 rotate with the fixed ring 82, they will block and conduct the beam of the infrared sensor 81 in sequence. When the reflector 83 passes the detection end, the beam is reflected and received, forming a pulse signal. After the reflector 83 leaves, the beam returns to its initial state and the pulse signal is interrupted. Through this cycle of "blocking-conducting", the infrared sensor 81 will transmit continuous pulse signals to the PLC controller 9 in real time. The PLC controller 9 calculates the actual rotation speed of the roller brush 51 based on the number of pulse signals received per unit time and the fixed number of reflectors 83 (when the number of reflectors 83 is fixed, the pulse signal frequency is positively correlated with the rotation speed of the roller brush 51. The denser the signal, the faster the rotation speed). After the infrared sensor 81 detects the speed value of the roller brush 51 and feeds it back to the PLC controller 9 in real time, the PLC controller 9 will dynamically adjust the operating power of the suction box 74 according to the speed value. Since the rotation speed of the roller brush 51 is directly related to the amount of dust raised during the sweeping process: the faster the roller brush 51 is, the greater the disturbance to the powder, and the more dust may be raised. At this time, the PLC controller 9 will increase the suction intensity of the suction box 74 accordingly. By increasing the negative pressure suction, it ensures that a large amount of dust is captured quickly and efficiently, and avoids the spread of dust. Conversely, the slower the roller brush 51 is, the less the powder is disturbed, and the less dust is raised. The PLC controller 9 will reduce the suction intensity of the suction box 74 at the same time to reduce energy consumption while ensuring effective dust removal. After the metal powder recycling operation is completed, the staff first manually opens the sealed door on the machine body 1, then takes out the powder collection box 6 located on one side of the printing table 2, pours the powder collected inside the powder collection box 6 into the storage container, and at the same time, the staff turns to the suction box 74, takes out the filter bag inside the suction box 74 used to filter fine dust, and gently shakes the fine powder collected inside the filter bag into the same storage container. The recycled metal powder needs to be sieved, dried and tested before it can be reused.

[0028] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A metal powder recovery structure for a metal 3D printing device, comprising a body (1) and a printing stage (2) disposed inside the body (1), characterized in that, Also includes: A weighing mechanism (3) is provided inside the printing table (2), and the weighing mechanism (3) is used to weigh the powder that falls on the surface of the printing table (2) during the printing process; The moving mechanism (4) is disposed on the inner side wall of the machine body (1), and the length direction of the moving mechanism (4) is the same as the length direction of the printing table (2); The push-sweep mechanism (5) is located inside the printing table (2), and one end of the push-sweep mechanism (5) is connected to the moving end of the moving mechanism (4). The push-sweep mechanism (5) is located on the upper surface of the weighing mechanism (3) and is used to sweep the powder on the surface of the weighing mechanism (3) to one side. The powder collection box (6) is located inside the machine body (1) and is located on one side of the printing table (2). The powder collection box (6) is used to collect the powder after cleaning the surface of the printing table (2). A dust suction mechanism (7) is located above the sweeping mechanism (5), and one end of the dust suction mechanism (7) is connected to the moving end of the moving mechanism (4). The dust suction mechanism (7) is used to suction and process the dust generated during the sweeping process. A speed detection mechanism (8) is set between the moving end of the moving mechanism (4) and one end of the pushing and sweeping mechanism (5), and the speed detection mechanism (8) is used to detect the rotation speed of the pushing and sweeping mechanism (5) and adjust the suction intensity of the dust suction mechanism (7). The PLC controller (9) is fixedly installed on the side wall of the machine body (1). The weighing mechanism (3), the moving mechanism (4), the dust suction mechanism (7) and the speed detection mechanism (8) are all electrically connected to the PLC controller (9).

2. The metal powder recovery structure for a metal 3D printing device according to claim 1, characterized in that, The weighing mechanism (3) includes a weighing plate (31) located inside the printing table (2), and two weighing sensors (32) are symmetrically fixed between the lower surface of the weighing plate (31) and the interior of the printing table (2).

3. The metal powder recovery structure for a metal 3D printing device according to claim 2, characterized in that, The moving mechanism (4) includes an electric slide rail (41) fixedly installed on the inner side wall of the body (1), and an electric slider (42) is slidably provided inside the electric slide rail (41).

4. The metal powder recovery structure for a metal 3D printing device according to claim 3, characterized in that, The push-brush mechanism (5) includes a roller brush (51) located inside the printing table (2), and the bristles of the roller brush (51) are in contact with the upper surface of the weighing plate (31). The two ends of the roller brush (51) have rotating shafts that pass through both sides of the printing table (2), and one end of the roller brush (51) has a rotating shaft that is rotatably connected to the side wall of the electric slider (42). A gear (52) is fixedly provided at the end of the roller brush (51) away from the electric slider (42). A rack (53) is fixedly provided along the length direction on the side wall of the printing table (2), and the rack (53) meshes with the gear (52).

5. A metal powder recovery structure for a metal 3D printing device according to claim 4, characterized in that, The dust suction mechanism (7) includes a circular shell (71) fixedly mounted on the side wall of the electric slider (42). One end of the roller brush (51) has a rotating shaft that passes through the interior of the circular shell (71). A first suction pipe (72) is provided above the roller brush (51). One end of the first suction pipe (72) is fixedly connected to the side wall of the circular shell (71), and the pipe wall of the first suction pipe (72) has a plurality of evenly distributed suction holes (73) on the side facing the roller brush (51). The body (1) A suction box (74) is fixedly provided on the side wall of the machine body (1). A second suction pipe (75) is fixedly provided at the bottom of the suction box (74). The end of the second suction pipe (75) away from the suction box (74) extends into the interior of the machine body (1) and is fixedly provided with a telescopic corrugated pipe (76). The end of the telescopic corrugated pipe (76) away from the second suction pipe (75) is fixedly connected to the pipe wall of the first suction pipe (72). A first gas switch valve (77) is fixedly provided on the pipe wall of the second suction pipe (75).

6. The metal powder recovery structure for a metal 3D printing device according to claim 5, characterized in that, The top of the suction box (74) is fixedly provided with a third suction pipe (78) extending into the interior of the machine body (1). The third suction pipe (78) is located above the printing table (2), and a second gas switch valve (79) is fixedly provided on the pipe wall of the third suction pipe (78).

7. A metal powder recovery structure for a metal 3D printing device according to claim 6, characterized in that, The speed detection mechanism (8) includes an infrared sensor (81) fixedly mounted on the inner wall of the circular shell (71). A fixed ring (82) is fixedly mounted on the rotating shaft of one end of the roller brush (51). A plurality of evenly distributed reflective sheets (83) are fixedly mounted on the circumferential wall of the fixed ring (82). The position of the infrared sensor (81) corresponds to the position of the reflective sheets (83).

8. The metal powder recovery structure for a metal 3D printing device according to claim 1, characterized in that, The upper surface of the printing table (2) has three adjacent sides that are raised upwards, and a strip-shaped opening is provided on the side of the printing table (2) opposite to the raised side.

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