Adjustable wind field structure for metal 3D printing

Abstract

According to the adjustable wind field structure for metal 3D printing, a main air blowing opening is fixed to the top end of one side of the inner wall of a printing cavity, and the air outlet end of the main air blowing opening is lower than a laser galvanometer; the auxiliary air blowing opening is formed in the inner wall of the printing cavity on the same side of the main air blowing opening, and the air outlet end of the auxiliary air blowing opening is parallel to the air outlet end of the main air blowing opening structure and forms an included angle of 180 degrees with the top of the printing cavity; the air outlet end of the power-assisted air blowing opening and the air outlet end of the main air blowing opening structure are arranged in a mirror image mode relative to each other along the middle axis face of the printing cavity. The air suction opening and the power-assisted air blowing opening are located in the inner wall of the same side of the printing cavity, and the air outlet end of the air suction opening is parallel to the air outlet end of the power-assisted air blowing opening; the air outlet end of the auxiliary air blowing opening is higher than the air inlet end of the air suction opening in the vertical height. The substrate powder bed is installed in the middle of the bottom of the printing cavity. Different wind field operation modes are formed through cooperation of the main and auxiliary air blowing openings and the air suction opening, the printing atmosphere in the printing cavity is optimized, and the problem of dead angles caused by a fixed airflow operation path in an existing wind field structure is solved.

Description

Technical Field

[0001] The present invention relates to the field of metal additive manufacturing, and in particular to a metal 3D printed adjustable wind field structure. Background Art

[0002] Metal selective laser melting technology is an advanced manufacturing technology that uses heat sources such as lasers or electron beams to melt and solidify metal powder layer by layer according to a preset digital model to construct complex three-dimensional metal parts.

[0003] During the operation of a metal 3D printer that uses laser selective melting technology, dust and splashing will inevitably occur when high-energy laser contacts metal powder. Dust will significantly interfere with laser power; splashing will randomly interfere with the unsintered powder bed, ultimately affecting the surface quality and mechanical properties of the printed sample. At present, the wind field structure of mainstream metal 3D printing equipment is arranged in a split-open arrangement in the printing chamber, with the air outlet and air suction outlet respectively set at the top and bottom of the inner wall, which can better eliminate the interference of splashing.

[0004] However, the existing solutions do not have a good solution for dealing with the dust in the printing chamber. The existing wind field structure can only blow away the dust in the lower right corner. As the height of the printed model changes, the height of the smoke and dust increases accordingly. The accumulation of dust near the laser galvanometer will cause the refraction of the laser beam and absorb the energy of the laser beam, which will reduce the laser power reaching the powder bed surface and distort the beam shape. In summary, the defects of the current wind field structure cause dust accumulation, which interferes with the surface quality and mechanical properties of the printed sample. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention provides an adjustable wind field structure for metal 3D printing, which solves the problem that the surface quality and mechanical properties of the printed samples cannot be reduced due to the defects of the wind field structure in the prior art.

[0006] In order to solve the above problems, the specific technical solutions are provided as follows:

[0007] A metal 3D printing adjustable wind field structure, comprising: a laser galvanometer, a main air blowing port, an auxiliary air blowing port, an auxiliary air blowing port, an air suction port, and a substrate powder bed;

[0008] The laser galvanometer is fixed in the printing chamber of the laser selective melting printer and is arranged at the top center of the printing chamber; the laser galvanometer has a built-in XY optical scanning head, an electronic drive amplifier and an optical reflective lens for guiding a high-energy laser beam;

[0009] The main air blowing port is fixed on the top of one side of the inner wall of the printing cavity, and the air outlet end of the main air blowing port is lower than the laser galvanometer; the auxiliary air blowing port is arranged on the inner wall of the printing cavity on the same side of the main air blowing port, and the air outlet end of the auxiliary air blowing port is parallel to the air outlet end of the main air blowing port structure, and is arranged at an angle of 180° with the top of the printing cavity; the air outlet end of the auxiliary air blowing port is mirrored relative to the air outlet end of the main air blowing port structure along the central axis of the printing cavity; the suction port and the auxiliary air blowing port are located on the inner wall on the same side of the printing cavity, and the air outlet end of the suction port is parallel to the air outlet end of the auxiliary air blowing port; the air outlet end of the auxiliary air blowing port is higher than the air inlet end of the suction port in vertical height; the substrate powder bed is installed in the center of the bottom of the printing cavity.

[0010] Furthermore, the main air outlet includes an airflow stabilizing structure, a main air outlet driving motor, and a main air outlet airflow guide plate;

[0011] The airflow stabilizing structure includes a long partition arranged in the flow channel to divide the entire flow channel into equal parts, and a short partition arranged inside a single flow channel divided by the long partition, the long partition runs through the entire flow channel along the air inlet direction, and the short partition is arranged from the middle of the flow channel along the air inlet direction; and the long partition and the short partition are both multiple pieces, and the long partition and the short partition are arranged alternately;

[0012] The main air outlet air flow guide plate and the main air outlet driving motor are arranged at the air outlet end of the main air outlet, and the main air outlet driving motor drives the main air outlet air flow guide plate to rotate.

[0013] Furthermore, the auxiliary air blowing outlet and the auxiliary air blowing outlet are also provided with an airflow stabilizing structure, an airflow guide plate and a driving motor, and the setting position and structure are the same as those of the main air blowing outlet.

[0014] Furthermore, a dust collection structure is provided at the air inlet end of the air suction port, and the dust collection structure consists of five guide vanes, one of which is parallel to the air inlet direction and centrally arranged at the air inlet end, the second left guide vane close to the centrally arranged guide vane forms an angle of 30° with the air inlet direction, the leftmost left guide vane forms an angle of 45° with the air inlet direction, and the right first guide vane and the right second guide vane are mirror-symmetrically arranged with the left first guide vane and the left second guide vane, respectively.

[0015] Furthermore, the air outlet end of the main air outlet is arranged at an angle of 135° with the top of the printing cavity.

[0016] Furthermore, a smoke concentration sensor is provided next to the laser galvanometer. The smoke concentration sensor detects the smoke concentration near the laser galvanometer and sends a signal to the built-in computer of the metal printer in real time. The built-in computer changes the wind field operation mode according to the smoke concentration to pursue a good printing environment.

[0017] Furthermore, the air outlet areas of the main air outlet and the auxiliary air outlet are the same and slightly larger than the auxiliary air outlet.

[0018] Furthermore, a filtering circulation device is arranged between the air outlet end of the air suction port and the air inlet end of the main air blowing port. The filtering circulation device is provided with a filter element cotton piece that can filter metal powder and splashes. At the same time, the compressor in the filtering circulation device transports the filtered clean protective gas to the air blowing port, so that the protective gas circulates in the printing chamber.

[0019] Furthermore, the air suction port is set at a distance higher than the substrate powder bed, which is conducive to the collection of dust and splashes, and the airflow in the wind field will not affect the normal printing of the substrate powder bed.

[0020] A method for adjusting the wind field of metal 3D printing is implemented based on the structure of metal 3D printing adjustable wind field, and includes the following steps:

[0021] The selective laser melting printer starts to work, the computer built into the selective laser melting printer sends a signal, and the built-in circulation filter of the selective laser melting printer starts to work, and the protective gas enters the main air outlet through the gas pipeline. At this time, the main air outlet driving motor is stationary, the main air outlet air flow guide plate is in the initial position, and the air flow moves obliquely from the main air outlet to the air suction port; at the same time, another protective gas is blown into the printing chamber through the auxiliary air outlet, and the guide plate driving motor and the air flow guide plate of the auxiliary air outlet are both in the initial state, and the air flow moves in the horizontal direction; the guide plate driving motor of the boosting air outlet receives the signal at the same time, and drives the air flow guide plate of the boosting air outlet to rotate upward to close the boosting air outlet; the printer starts to run, and the splashes generated by the substrate powder bed are transported to the air suction port by the air flow blown out of the auxiliary air outlet, and the generated dust is transported to the air suction port by the air flow blown out of the main air outlet after reaching a certain height;

[0022] After printing for a period of time, when the smoke concentration sensor arranged in the printing chamber detects that the dust concentration near the laser galvanometer exceeds the set threshold, a signal is sent to the computer built into the selective laser melting printer, and the computer sends a signal to drive the guide plate driving motor of the main blowing port, driving the airflow guide plate of the main blowing port to rotate to be perpendicular to the top of the printing chamber, and the airflow is transported vertically downward; at the same time, the guide plate driving motor of the auxiliary blowing port drives the airflow guide plate of the auxiliary blowing port to rotate until the direction of the airflow guide plate is perpendicular to the side wall of the printing chamber, and the airflow is transported from the auxiliary blowing port to the main blowing port; the blowing direction of the auxiliary blowing port remains unchanged; the wind field constructs a rectangular cycle in the printing chamber, and the dust near the laser galvanometer is transported to the bottom of the printing chamber through the wind field, and finally blown to the suction port by the auxiliary blowing port;

[0023] When the smoke concentration sensor arranged in the printing chamber detects that the dust concentration near the laser galvanometer returns to the normal range, a signal is sent to the computer built into the selective laser melting printer, and the guide plate driving motor of the main air blowing port and the guide plate driving motor of the auxiliary air blowing port drive the airflow guide plate to reset, and the wind field returns to its initial state.

[0024] The beneficial effects of the present invention are:

[0025] The present invention can form different wind field operation modes through the coordination of the main air outlet, the auxiliary air outlet, the auxiliary air outlet and the air suction outlet, greatly optimizing the printing atmosphere in the printing chamber and avoiding the dead angle problem caused by the fixed air flow operation path in the existing wind field structure. Relying on the adaptive wind field operation path, the problem of interference with the surface quality and mechanical properties of the printed sample due to the accumulation of metal powder dust in the dead angle of the wind field is reduced, thereby improving the overall quality of the product, reducing the cost of the entire manufacturing process, and improving the economic benefits of production. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the three-dimensional structure of the adjustable wind farm structure in an embodiment of the present invention.

[0027] Figure 2 It is a front view of the adjustable wind farm structure in an embodiment of the present invention.

[0028] Figure 3 It is a schematic diagram of the three-dimensional structure of the main air outlet in an embodiment of the present invention.

[0029] Figure 4 It is a detailed structural diagram of the adjustable wind farm structure in an embodiment of the present invention.

[0030] Figure 5 Schematic diagram of an airflow stabilizing structure in an embodiment of the present invention.

[0031] Figure 6 It is a schematic diagram of the three-dimensional structure of the air suction port in an embodiment of the present invention.

[0032] Figure 7 It is a schematic diagram of the working principle of the initial state of the adjustable wind farm structure in an embodiment of the present invention.

[0033] Figure 8 It is a schematic diagram of the working principle of the circulating wind operation state of the adjustable wind field structure in an embodiment of the present invention.

[0034] In the figure, laser galvanometer 1, main air blowing port 2, auxiliary air blowing port 3, auxiliary air blowing port 4, air suction port 5, substrate powder bed 6;

[0035] Airflow stabilizing structure 2-1, main air outlet driving motor 2-2, main air outlet airflow guide plate 2-3, auxiliary air outlet driving motor 3-1, auxiliary air outlet airflow guide plate 3-2, power-assisted air outlet driving motor 4-1, power-assisted air outlet airflow guide plate 4-2, and dust collecting structure 5-1. DETAILED DESCRIPTION

[0036] The present invention will be described in detail below according to the accompanying drawings and preferred embodiments, and the purpose and effect of the present invention will become more clear. The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0037] like Figure 1 and Figure 2 As shown, the metal 3D printing adjustable wind field structure of this embodiment includes: a laser galvanometer 1, a main air outlet 2, an auxiliary air outlet 3, an auxiliary air outlet 4, an air suction port 5 and a substrate powder bed 6. The laser galvanometer 1 is fixed in the printing chamber of the laser selective melting printer, and is arranged at the top center of the printing chamber. It has a built-in XY optical scanning head, an electronic drive amplifier and an optical reflective lens for guiding the high-energy laser beam. The main air outlet 2 is fixed to the top of one side of the inner wall of the printing chamber, and is arranged at an angle of 135° with the top of the printing chamber. The vertical height of the air outlet end of the main air outlet 2 is slightly lower than the laser galvanometer 1. The auxiliary air outlet 3 is arranged on the inner wall of the printing chamber on the same side of the main air outlet 2, parallel to the main air outlet 2 in the vertical direction, and arranged at an angle of 180° with the top of the printing chamber. The air outlet end of the auxiliary air outlet 4 is arranged in a mirror image relative to the air outlet end of the main air outlet 2 along the central axis of the printing chamber. The main air outlet 2 and the auxiliary air outlet 3 have the same air outlet area and are slightly larger than the auxiliary air outlet 4. The air inlet 5 is arranged on the inner wall of the printing chamber on the same side as the auxiliary air outlet 4. The air outlet end of the air inlet 5 is parallel to the air outlet end of the air outlet 4, and the auxiliary air outlet 3 is slightly higher than the air inlet 5 in vertical height. The substrate powder bed 6 is installed in the center of the bottom of the printing chamber, such as Figure 2The air inlet end of the air suction port 5 is higher than the substrate powder bed 6 by a certain distance, which is conducive to the collection of dust and splashing objects, and the air flow in the wind field will not affect the normal printing of the substrate powder bed.

[0038] A smoke concentration sensor is provided next to the laser galvanometer 1, which is used to detect the smoke concentration near the laser galvanometer 1 and send a signal to the built-in computer of the metal printer in real time. The built-in computer will change the wind field operation mode according to the smoke concentration to pursue a good printing environment.

[0039] like Figure 3 and Figure 4 As shown, the main air outlet 2 includes an airflow stabilizing structure 2-1, a guide plate driving motor 2-2, and a main air outlet airflow guide plate 2-3. Figure 5 As shown, the airflow stabilizing structure 2-1 includes a long partition arranged in the flow channel to divide the entire flow channel into equal parts, and a short partition arranged inside a single flow channel divided by the long partition. The long partition runs through the entire flow channel along the air inlet direction, and the short partition is arranged from the middle of the flow channel along the air inlet direction. The long partition and the short partition are both multiple pieces, and the long partition and the short partition are arranged alternately; the main air outlet airflow guide plate and the guide plate driving motor are arranged at the air outlet end of the main air outlet, and the guide plate driving motor drives the main air outlet airflow guide plate to rotate. Figure 5 As shown, there are 5 long partitions and 6 short partitions, and the length of the short partition is half of the length of the long partition. After the filtered rare gas passes through the airflow stabilizing structure 2-1, a stable airflow can be blown out from the air outlet of the main air outlet 2. The main air outlet driving motor 2-2 receives the metal printer signal and adjusts the direction of the main air outlet airflow guide plate 2-3, thereby adjusting the airflow blowing direction of the main air outlet 2. Figure 4 As shown, the auxiliary air outlet 3 is provided with an auxiliary air outlet drive motor 3-1 and an auxiliary air outlet air flow guide plate 3-2; the booster air outlet 4 is provided with a booster air outlet drive motor 4-1 and a booster air outlet air flow guide plate 4-2, which are the same as the main air outlet drive motor 2-2 and the main air outlet air flow guide plate 2-3 provided in the main air outlet 2. The auxiliary air outlet 3 and the booster air outlet 4 can also be provided with an air flow stabilizing structure. Figure 1 As shown, the auxiliary air outlet 3 is also provided with a plurality of guide plates for dividing the airflow.

[0040] like Figure 6 As shown, the air inlet end of the air suction port 5 is provided with a dust collection structure 5-1, and five guide vanes are provided near the air inlet end of the dust collection structure 5-1, one of which is parallel to the air inlet direction and is centrally arranged, and the left second guide vane close to the central guide vane is 30° to the air inlet direction, and the leftmost guide vane is 45° to the air inlet direction. The two guide vanes on the right side of the central guide vane are mirror-symmetrically arranged with the left side. The funnel-shaped air suction port 5 cooperates with the dust collection structure 5-1 to make the outlet wind speed evenly distributed while reducing the dust dispersion caused by turbulence.

[0041] In addition, a filtering circulation device can be arranged between the air outlet end of the air suction port 5 and the air inlet end of the main air blowing port 2. The filtering circulation device is provided with a filter element cotton piece that can filter metal powder and splashes. At the same time, the compressor in the filtering circulation device transports the filtered clean protective gas to the air blowing port, so that the protective gas circulates in the printing chamber.

[0042] The adjustable wind field method for metal 3D printing proposed based on the metal 3D printing adjustable wind field structure of this embodiment includes the following steps:

[0043] The selective laser melting printer starts working, the computer built into the selective laser melting printer sends a signal, the built-in circulation filter of the selective laser melting printer starts working, and the protective gas enters the main air outlet 2 through the gas pipeline. At this time, the main air outlet drive motor 2-2 is stationary, the main air outlet airflow guide plate 2-3 is in the initial position, and the airflow moves from the upper left to the lower right. Figure 7 As shown, at the same time, another protective gas is blown into the printing chamber through the auxiliary blowing port 3, the auxiliary blowing port driving motor 3-1 and the auxiliary blowing port airflow guide plate 3-2 are both in the initial state, and the airflow moves in the horizontal direction; the booster blowing port driving motor 4-1 receives a signal at the same time, driving the booster blowing port airflow guide plate 4-2 to rotate upward to close the booster blowing port 4. At this time, the printer starts to run, and the splashes generated by the substrate powder bed 6 are transported to the air suction port 5 by the airflow blown out of the auxiliary blowing port 3, and the generated dust reaches a certain height and is transported to the air suction port 5 by the airflow blown out of the main blowing port 2.

[0044] After printing for a period of time, the smoke concentration sensor installed in the printing chamber detects that the dust concentration near the laser galvanometer 1 is too high, and sends a signal to the computer built into the selective laser melting printer. The computer interprets the signal to drive the main air outlet drive motor 2-2, and the main air outlet airflow guide plate 2-3 rotates clockwise to a perpendicular angle to the top of the printing chamber, and the airflow is transported vertically downward. At the same time, the booster air outlet drive motor 4-1 drives the booster air outlet airflow guide plate 4-2 to rotate counterclockwise by 45 degrees until the guide plate direction is perpendicular to the side wall of the printing chamber, and the airflow is transported horizontally from right to left. Figure 8 As shown. The blowing direction of the auxiliary air outlet 3 remains unchanged. At this time, the wind field forms a counterclockwise rectangular cycle in the printing chamber, and the dust near the laser galvanometer 1 is transported to the bottom of the printing chamber through the counterclockwise wind field, and finally blown to the air suction port 5 by the auxiliary air outlet 3.

[0045] When the smoke concentration sensor in the printing chamber detects that the dust concentration near the laser galvanometer 1 returns to the normal range, a signal is sent to the computer built into the selective laser melting printer, and the main air outlet drive motor 2-2 and the auxiliary air outlet drive motor 4-1 drive the air flow guide to reset, and the wind field is restored. Figure 7The initial state.

[0046] During the printing process, the air volume and blowing direction of the three air outlets and the air intake port can also be manually set. According to the dispersion range of the metal powder dust, the direction of the airflow in the wind direction can be flexibly selected to construct different forms of wind fields, so as to better clean the dust and splashing in the printing chamber during the printing process.

[0047] The present invention changes the operation mode of the wind field in the printing chamber by controlling the driving motor to change the coordination of the blowing direction and air volume between the blowing port and the suction port, thereby avoiding the dead angle problem caused by the fixed airflow running path in the existing wind field structure. Relying on the adaptive wind field running path, the problem of metal powder dust accumulation in the dead angle of the wind field interfering with the surface quality and mechanical properties of the printed sample is reduced, thereby improving the overall quality of the product. The cost of the entire manufacturing process is reduced, and the economic benefits of production are improved.

[0048] Those skilled in the art can understand that the above are only preferred examples of the invention and are not intended to limit the invention. Although the invention is described in detail with reference to the above examples, those skilled in the art can still modify the technical solutions recorded in the above examples or replace some of the technical features therein with equivalents. Any modification, equivalent replacement, etc. made within the spirit and principle of the invention shall be included in the protection scope of the invention.

Claims

1. A metal 3D printed adjustable wind field structure, characterized in that: include: Laser galvanometer, main air blowing port, auxiliary air blowing port, auxiliary air blowing port, air suction port, substrate powder bed; The laser galvanometer is fixed in the printing chamber of the laser selective melting printer and is arranged at the top center of the printing chamber; the laser galvanometer has a built-in XY optical scanning head, an electronic drive amplifier and an optical reflective lens for guiding a high-energy laser beam; The main air blowing port is fixed on the top of one side of the inner wall of the printing cavity, and the air outlet end of the main air blowing port is lower than the laser galvanometer; the auxiliary air blowing port is arranged on the inner wall of the printing cavity on the same side of the main air blowing port, and the air outlet end of the auxiliary air blowing port is parallel to the air outlet end of the main air blowing port structure, and is arranged at an angle of 180° with the top of the printing cavity; the air outlet end of the auxiliary air blowing port is mirrored relative to the air outlet end of the main air blowing port structure along the central axis of the printing cavity; the suction port and the auxiliary air blowing port are located on the inner wall on the same side of the printing cavity, and the air outlet end of the suction port is parallel to the air outlet end of the auxiliary air blowing port; the air outlet end of the auxiliary air blowing port is higher than the air inlet end of the suction port in vertical height; the substrate powder bed is installed in the center of the bottom of the printing cavity.

2. The metal 3D printed adjustable wind field structure according to claim 1, characterized in that: The main air outlet comprises an airflow stabilizing structure, a main air outlet driving motor, and a main air outlet airflow guide plate; The airflow stabilizing structure includes a long partition arranged in the flow channel to divide the entire flow channel into equal parts, and a short partition arranged inside a single flow channel divided by the long partition, the long partition runs through the entire flow channel along the air inlet direction, and the short partition is arranged from the middle of the flow channel along the air inlet direction; and the long partition and the short partition are both multiple pieces, and the long partition and the short partition are arranged alternately; The main air outlet air flow guide plate and the main air outlet driving motor are arranged at the air outlet end of the main air outlet, and the main air outlet driving motor drives the main air outlet air flow guide plate to rotate.

3. The metal 3D printed adjustable wind field structure according to claim 2, characterized in that: The auxiliary air blowing port and the auxiliary air blowing port are also provided with an airflow stabilizing structure, an airflow guide plate and a driving motor, and the setting position and structure are the same as those of the main air blowing port.

4. The metal 3D printed adjustable wind field structure according to claim 3, characterized in that: A dust collection structure is provided at the air inlet end of the air suction port, and the dust collection structure consists of five guide vanes, one of which is parallel to the air inlet direction and centrally arranged at the air inlet end, the second left guide vane close to the centrally arranged guide vane forms an angle of 30° with the air inlet direction, the leftmost left guide vane forms an angle of 45° with the air inlet direction, and the right first guide vane and the right second guide vane are mirror-symmetrically arranged with the left first guide vane and the left second guide vane, respectively.

5. The metal 3D printed adjustable wind field structure according to claim 4, characterized in that: The air outlet end of the main air outlet is arranged at an angle of 135° with the top of the printing cavity.

6. The metal 3D printed adjustable wind field structure according to claim 5, characterized in that: A smoke concentration sensor is arranged next to the laser galvanometer. The smoke concentration sensor detects the smoke concentration near the laser galvanometer and sends a signal to the built-in computer of the metal printer in real time. The built-in computer changes the wind field operation mode according to the smoke concentration to pursue a good printing environment.

7. The metal 3D printed adjustable wind field structure according to claim 1, characterized in that: The air outlet areas of the main air outlet and the auxiliary air outlet are the same and slightly larger than the auxiliary air outlet.

8. The metal 3D printed adjustable wind field structure according to claim 1, characterized in that: A filtering circulation device is arranged between the air outlet end of the air suction port and the air inlet end of the main air blowing port. The filtering circulation device is provided with a filter element cotton piece that can filter metal powder and splashes. At the same time, the compressor in the filtering circulation device transports the filtered clean protective gas to the air blowing port, so that the protective gas circulates in the printing chamber.

9. The metal 3D printed adjustable wind field structure according to claim 1, characterized in that: The air suction port is set higher than the substrate powder bed, which is conducive to the collection of dust and splashes. At the same time, the air flow in the wind field will not affect the normal printing of the substrate powder bed.

10. A method for adjustable wind field of metal 3D printing, based on the metal 3D printing adjustable wind field structure of claim 6, characterized in that: The following steps are involved: The selective laser melting printer starts to work, the computer built into the selective laser melting printer sends a signal, the built-in circulation filter of the selective laser melting printer starts to work, and the protective gas enters the main air outlet through the gas pipeline. At this time, the main air outlet driving motor is stationary, the main air outlet air flow guide plate is in the initial position, and the air flow moves obliquely from the main air outlet to the air suction port; at the same time, another protective gas is blown into the printing chamber through the auxiliary air outlet, the guide plate driving motor and the air flow guide plate of the auxiliary air outlet are in the initial state, and the air flow moves in the horizontal direction; the guide plate driving motor of the boosting air outlet receives the signal at the same time, and drives the air flow guide plate of the boosting air outlet to rotate upward to close the boosting air outlet; The printer starts running, and the splashes generated by the substrate powder bed are transported to the air inlet by the airflow blown out of the auxiliary air outlet, and the generated dust reaches a certain height and is transported to the air inlet by the airflow blown out of the main air outlet; After printing for a period of time, when the smoke concentration sensor arranged in the printing chamber detects that the dust concentration near the laser galvanometer exceeds the set threshold, a signal is sent to the computer built into the selective laser melting printer, and the computer sends a signal to drive the guide plate driving motor of the main blowing port, driving the airflow guide plate of the main blowing port to rotate to be perpendicular to the top of the printing chamber, and the airflow is transported vertically downward; at the same time, the guide plate driving motor of the auxiliary blowing port drives the airflow guide plate of the auxiliary blowing port to rotate until the direction of the airflow guide plate is perpendicular to the side wall of the printing chamber, and the airflow is transported from the auxiliary blowing port to the main blowing port; the blowing direction of the auxiliary blowing port remains unchanged; the wind field constructs a rectangular cycle in the printing chamber, and the dust near the laser galvanometer is transported to the bottom of the printing chamber through the wind field, and finally blown to the suction port by the auxiliary blowing port; When the smoke concentration sensor arranged in the printing chamber detects that the dust concentration near the laser galvanometer returns to the normal range, a signal is sent to the computer built into the selective laser melting printer, and the guide plate driving motor of the main air blowing port and the guide plate driving motor of the auxiliary air blowing port drive the airflow guide plate to reset, and the wind field returns to its initial state.

Images