Wind farm structure and metal 3D printer

Abstract

This invention belongs to the field of metal 3D printing technology, specifically relating to a wind field structure and a 3D metal printer. The wind field structure includes a housing, with a printing cavity formed inside the housing. The housing includes a first side and a second side, which are arranged opposite to each other. A first air outlet is provided at the lower part of the first side, and a second air outlet is provided at the upper part of the second side. When airflow is introduced into the wind field structure of this invention, a stable airflow field can be formed within the housing, thereby effectively removing splashes at the bottom of the housing and dust deposits on the laser lens at the top of the housing, meeting the requirements for high-quality printing.

Description

Technical Field

[0001] This invention belongs to the field of metal 3D printing technology, specifically relating to a wind field structure and a metal 3D printer. Background Technology

[0002] This section provides only background information relevant to this disclosure and is not necessarily prior art.

[0003] Additive manufacturing (3D printing) technology is better suited for creating complex-shaped parts compared to traditional processing methods. Due to its technological flexibility, additive manufacturing has been widely applied in fields such as biomedicine, automotive, aerospace, and military industries, demonstrating enormous application potential. Selective laser melting (SLM) is the most popular technique in metal additive manufacturing. However, the complex heat conduction process in SLM often results in the generation of spatter. This spatter can affect the porosity, defects, and surface roughness of the printed part, thus impacting manufacturing stability, energy efficiency, and the quality of the printed part. The protective gas flow within the printing cavity not only provides shielding but also removes byproducts of the laser manufacturing process, such as spatter and welding fumes. When spatter cannot be carried away by the protective gas flow within the printing cavity and falls into the powder bed, it may be remelted by the laser, becoming inclusions that ultimately affect the mechanical properties of the printed part. Therefore, the flow rate of the protective gas within the printing cavity should be as high and stable as possible.

[0004] Currently, the air inlets and suction outlets of SLM equipment are mostly arranged in a opposed configuration, meaning that the air inlet and suction outlet are respectively set on opposite sides of the printing cavity. This design can ensure a relatively stable bottom airflow when the incident airflow is small. However, due to the insufficient airflow velocity, it is difficult to prevent splatter dust from spreading to the laser lens located at the top of the printing cavity and causing equipment contamination, and it is also difficult to transport splatter particles outside the toner bed. Increasing the incident airflow velocity will easily cause upward flow separation and generate vortices under the Bernoulli effect, making it difficult to form a stable airflow field within the printing cavity. In related technologies, some SLM devices have air vents at the top of the printing cavity to remove soot deposits on the top laser lens. However, the upper and lower air vents are not designed on the same side. This design makes it difficult to achieve the removal function when the airflow velocity at the upper air vent is low. At higher velocities, the competition between the two sides will disrupt the airflow field in the entire printing cavity. The horizontal airflow at the bottom is difficult to maintain stability, and the direction and structure of the vortex in the middle and upper parts are constantly changing. This cannot effectively prevent the spatter particles from contaminating the powder bed and the soot from depositing on the laser lens, making it difficult to meet the requirements for high-quality printing. Summary of the Invention

[0005] The purpose of this invention is to at least solve the problems of existing printing cavities failing to form a stable airflow field, effectively preventing spatter particles from contaminating the powder bed, and causing dust deposition on the laser lens, thus making it difficult to meet the requirements for high-quality printed parts. This purpose is achieved through the following technical solutions:

[0006] A first aspect of the present invention provides a wind field structure for a metal 3D printer. The wind field structure includes a housing, and a printing cavity is formed inside the housing. The housing includes a first side and a second side, which are disposed opposite to each other. A first air outlet is provided at the lower part of the first side and a second air outlet is provided at the upper part of the second side.

[0007] According to the wind field structure of the present invention, when used in metal 3D printer applications, by setting the first and second air outlets on opposite sides, the competition between the airflows emitted on the same side can be eliminated when a protective airflow is introduced into the wind field structure. A relatively stable vortex airflow can be established within the housing, which can better remove the splatter at the bottom of the housing and the soot deposits on the laser lens at the top of the housing. The vortex airflow within the housing can also suppress the upward flow of the bottom lateral airflow, thereby enhancing the bottom lateral airflow. That is, a large removal efficiency can be achieved at a relatively small airflow velocity, thus meeting the high-quality forming requirements of the printed parts.

[0008] In addition, the wind farm structure according to the present invention may also have the following additional technical features:

[0009] In some embodiments of the present invention, an air intake is provided at the lower part of the second side, and the position of the air intake is not higher than the position of the first air outlet.

[0010] In some embodiments of the present invention, the first air outlet extends along the width direction of the first side surface;

[0011] And / or, the second air outlet and the air inlet extend along the width direction of the second side.

[0012] In some embodiments of the present invention, the wind field structure includes a protrusion disposed on the second side surface, a cavity is formed inside the protrusion, the printing cavity is connected to the cavity, the protrusion includes a first protrusion and a second protrusion connected to each other, the first protrusion is located above the second protrusion, and the air intake is disposed on the second protrusion.

[0013] In some embodiments of the present invention, the housing includes a bottom surface, the bottom of the second protrusion is higher than the bottom surface, and the bottom of the second protrusion forms a stepped structure with the bottom surface.

[0014] In some embodiments of the present invention, the wind field structure further includes an air volume regulating device, and at least one of the first air outlet and the second air outlet is provided with the air volume regulating device.

[0015] In some embodiments of the present invention, the air outlet area of ​​the first air outlet is larger than the air outlet area of ​​the second air outlet.

[0016] In some embodiments of the present invention, the wind field structure further includes a rectification structure, and at least one of the first air outlet, the second air outlet and the air intake is provided with the rectification structure;

[0017] And / or, the wind field structure further includes a flow guiding structure, and at least one of the first air outlet, the second air outlet and the air intake is provided with the flow guiding structure.

[0018] A second aspect of the present invention provides a metal 3D printer, the metal 3D printer comprising:

[0019] The wind field structure proposed in the first aspect of this invention;

[0020] A laser emitting device, comprising a laser and a laser lens, wherein the laser is disposed inside the housing and located at the top of the housing, and the laser lens covers the outside of the laser, and the airflow blown out by the first air outlet flows through the laser lens;

[0021] A powder bed is provided, which is vertically and flexibly disposed at the bottom of the housing. The laser emitted by the laser is directed onto the powder bed through the laser lens, and the airflow blown out by the second air outlet flows through the powder bed.

[0022] According to the metal 3D printer of the present invention, the protective airflow entering the air field structure can form a stable airflow inside the shell, which can simultaneously clean the top and bottom of the shell and meet the requirements for high-quality molding of printed parts.

[0023] In addition, the metal 3D printer according to the present invention may also have the following additional technical features:

[0024] In some embodiments of the present invention, the metal 3D printer further includes a first air inlet pipe, a second air inlet pipe, and an air outlet pipe. The air inlet end of the air outlet pipe is connected to the air intake of the air field structure, and the air outlet end of the air outlet pipe is connected to the air inlet ends of the first air inlet pipe and the second air inlet pipe, respectively. The air outlet end of the first air inlet pipe is connected to the first air outlet, and the air outlet end of the second air inlet pipe is connected to the second air outlet. A filter device and an air supply device are provided on the air outlet pipe. Attached Figure Description

[0025] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0026] Figure 1 A schematic diagram of a wind field structure according to an embodiment of the present invention is shown (the black straight arrows in the figure indicate the airflow direction);

[0027] Figure 2 A schematic diagram of a first side view of a wind farm structure according to an embodiment of the present invention is shown.

[0028] Figure 3 A schematic diagram of the second side structure of the wind field structure according to an embodiment of the present invention is shown.

[0029] Figure 4 A schematic diagram of a metal 3D printer according to an embodiment of the present invention is shown.

[0030] Figures 5a-5b The diagram schematically illustrates the airflow path of a wind field structure in the prior art, in which air inlets and air outlets are respectively provided on opposite sides of the bottom of the housing (the black dashed arrows in the diagram indicate the airflow direction).

[0031] Figures 6a-6c An exemplary diagram of the airflow path of a wind field structure with two air outlets on the same side of the housing in the prior art is shown (the black dashed arrows in the diagram indicate the airflow direction);

[0032] Figure 7 An exemplary diagram of the airflow path within a wind field structure according to an embodiment of the present invention is shown (the black dashed arrows in the diagram indicate the airflow direction).

[0033] The attached figures are labeled as follows:

[0034] 1. Housing; 11. First side; 12. Second side; 13. Bottom; 14. Top; 131. Powder bed; 141. Laser lens; 142. Laser; 2. First air outlet; 3. Second air outlet; 4. Air inlet; 5. Protrusion; 51. First protrusion; 52. Second protrusion; 521. Stepped structure; 6. First air inlet pipe; 7. Second air inlet pipe; 8. Air outlet pipe; 9. Filter device; 10. Air supply device. Detailed Implementation

[0035] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0036] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0037] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0038] For ease of description, spatial relative terms may be used in the text to describe the relationship of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "over," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure is flipped, an element described as "below other elements or features" or "below other elements or features" would subsequently be oriented as "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.

[0039] The following detailed description of this embodiment is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and examples can be combined with each other.

[0040] According to an exemplary embodiment of the present invention, this embodiment proposes a wind field structure for use in a metal 3D printer, such as... Figure 1 As shown, the wind field structure includes a housing 1. The structure of the housing 1 is not limited; for example, the housing 1 has a cubic structure, but it can also be other regular or irregular structures, and can be flexibly designed according to actual needs. A printing cavity is formed inside the housing 1, which is used to circulate protective airflow, such as an inert airflow. The bottom of the housing 1 can be used to house a liftable powder bed 131, the top of the housing 1 can be used to house a laser emitting device, and the interior of the housing 1 can be used to house a powder spreading device. The powder spreading device can reciprocate along the powder bed 131 to spread metal powder layer by layer on the powder bed 131. The laser emitting device includes a laser emitter and a laser lens 141. The laser lens 141 covers the laser emitter 142 so that the laser beam emitted by the laser emitter 142 enters the powder bed 131 and scans layer by layer on the powder bed 131 according to the path planned in the 3D CAD slicing model. The scanned metal powder melts and solidifies to achieve a metallurgical bonding effect, ultimately obtaining the metal printed part designed in the model. The housing 1 includes a first side surface 11 and a second side surface 12, which are disposed opposite to each other. A first air outlet 2 is provided at the lower part of the first side surface 11, and a second air outlet 3 is provided at the upper part of the second side surface 12. In one example, the housing 1 includes a top surface 14 and a bottom surface 13, along the height direction of the housing 1 (refer to...). Figure 1(In the direction shown by the Y-axis), the distance between the first air outlet 2 and the top surface 14 is less than or equal to 30mm, and the distance between the second air outlet 3 and the bottom surface 13 is less than or equal to 30mm. For example, the distance between the first air outlet 2 and the top surface 14 is 20mm, and the distance between the second air outlet 3 and the bottom surface 13 is 20mm.

[0041] In this embodiment, when the printed part is processed inside the housing 1 using a metal 3D printer, the protective airflow entering the housing 1 through the first air outlet 2 ensures that the splatter at the bottom of the housing 1 does not fall into the powder bed 131. The protective airflow entering the housing 1 through the second air outlet 3 can clean the dust deposits on the top laser lens 141. The airflow direction is referenced... Figure 1 The direction is indicated by the black straight arrow. Furthermore, by setting the first air outlet 2 and the second air outlet 3 on opposite sides, this embodiment eliminates the competition between airflows exiting from the same side and establishes a relatively stable vortex airflow within the housing 1. With the powder spreading device reciprocating, the airflow field within the housing 1 can be stabilized in a shorter time. The vortex airflow within the housing 1 suppresses the upward flow of the bottom lateral airflow, enhancing its effect and achieving high removal efficiency at a relatively low airflow velocity, thus meeting the requirements for high-quality printing. Simultaneously, the use of fewer air outlets and suction outlets 4 in this embodiment makes it easier to ensure the airtightness of the entire housing 1, preventing leakage and contamination from protective airflow and splashes. The airflow structure of this embodiment is an improvement upon existing airflow structures, making the customization, installation, and maintenance of the entire metal 3D printer more convenient.

[0042] In some embodiments, an air intake 4 is provided at the lower part of the second side 12. The position of the air intake 4 is not higher than the position of the first air outlet 2. This is more conducive to the discharge of protective airflow and splashes inside the housing 1 through the air intake, preventing splashes from falling onto the powder bed 131. In addition, the air intake 4 and the first air outlet 2 are designed to be open at the bottom so as to form a stable transverse airflow at the bottom of the housing 1. Under the combined action of the stable vortex airflow and the transverse airflow at the bottom, the splashes located at the bottom of the housing 1 and the dust deposits on the laser lens 141 at the top can be more effectively removed.

[0043] In some implementations, such as Figure 2 As shown, the first air outlet 2 extends along the width direction of the first side surface 11, and the width direction of the first side surface 11 is referenced to... Figure 2The direction is shown by the X2 axis in the diagram. The first air outlet 2 can be a long strip-shaped outlet that extends continuously along the width direction of the first side surface 11, or it can be multiple outlets that extend intermittently along the width direction of the first side surface 11. Extending the first air outlet 2 along the length direction of the first side surface 11 can increase the air blowing area of ​​the first air outlet 2, thereby ensuring that the protective airflow blown into the housing 1 by the first air outlet 2 can cover the bottom of the housing 1, and further ensuring that the splashes do not fall into the powder bed 131.

[0044] In some implementations, such as Figure 3 As shown, the second air outlet 3 and the air inlet 4 extend along the width direction of the second side surface 12, which is referenced from the width direction of the second side surface 12. Figure 3 The direction is shown by the X2 axis. The first air outlet 2 or air inlet 4 can be a long strip-shaped air outlet that extends continuously along the width direction of the second side 12, or it can be multiple air outlets that extend discontinuously along the width direction of the second side 12. The second air outlet 3 extends along the length direction of the second side 12, which can increase the air blowing area of ​​the second air outlet 3, thereby ensuring that the protective airflow blown into the housing 1 by the second air outlet 3 can cover the top of the housing 1, and can better clean the dust deposits on the laser lens 141 set on the top of the housing 1. The air inlet 4 extends along the length direction of the second side 12, which can increase the air suction area of ​​the air inlet 4, and can further ensure that the protective airflow forms a stable lateral flow at the bottom of the housing 1.

[0045] In some implementations, such as Figure 1 As shown, the wind farm structure includes a protrusion 5, which is disposed on the second side surface 12. A cavity is formed within the protrusion 5, and the printing cavity communicates with it, allowing the protective airflow within the printing cavity to enter the cavity. The protrusion 5 can be disposed independently of the housing 1 and connected to the second side surface 12 of the housing 1 by means of snap-fit, bonding, connector connection, or welding. Alternatively, the protrusion 5 and the second side surface 12 can be integrally formed. In one example, the protrusion 5 forms a bulge protruding from the second side surface 12 towards the outside of the housing 1, as shown in the figure. Figure 1 The direction indicated by the X1 axis. The structure of the protrusion 5 is not limited; in one example, as shown... Figure 1As shown, the protrusion 5 has a cubic structure, but it can also have other regular or irregular structures, which can be flexibly designed according to actual needs. The protrusion 5 includes a first protrusion 51 and a second protrusion 52 connected to each other. The first protrusion 51 is located above the second protrusion 52, and the air intake 4 is set on the second protrusion 52. After the protective airflow enters the housing 1 through the first air outlet 2 and the second air outlet 3, a stable transverse airflow is formed at the bottom of the housing 1, and a stable vortex airflow is formed in the middle of the housing 1. When the splashes flow to the protrusion 5 with the vortex airflow, the first protrusion 51 can intercept the splashes, so that the splashes are discharged from the housing 1 along the air intake 4. Along the height direction of the housing 1, the size of the first protrusion 51 is larger than the size of the second protrusion 52 in order to obtain a better splash interception effect.

[0046] In some implementations, such as Figure 1 As shown, the housing 1 includes a bottom surface 13, the bottom of the second protrusion 52 is higher than the bottom surface 13, and the bottom of the first protrusion 51 forms a stepped structure 521 with the bottom surface 13. The stepped structure 521 is used to guide the airflow part at the bottom of the housing 1 to move upward and accelerate the formation of vortex airflow inside the housing 1.

[0047] In some embodiments, the airflow structure is configured such that the outlet velocity of the protective airflow entering the housing 1 through the first air outlet 2 is less than the outlet velocity of the airflow entering the housing 1 through the second air outlet 3. This is because the vortex airflow within the housing 1 can suppress the upward flow of the bottom transverse airflow, thus enhancing the bottom transverse airflow. In other words, a higher purging efficiency can be achieved even with a lower airflow velocity at the first air outlet. For example, the outlet velocity of the first air outlet 2 is 40% to 80% of the outlet velocity of the second air outlet 3; preferably, the outlet velocity of the first air outlet 2 is 60% of the outlet velocity of the second air outlet 3. In one example (not shown in the figure), the wind field structure includes an airflow regulating device. At least one of the first air outlet 2 and the second air outlet 3 is equipped with an airflow regulating device. The airflow regulating device can adjust the outlet airflow so that the outlet airflow of the first air outlet 2 is less than that of the second air outlet 3. When the airflow areas of the first air outlet 2 and the second air outlet 3 are the same, the airflow velocity of the first air outlet 2 is less than that of the second air outlet 3. The airflow regulating device can be adjusted manually or intelligently. In another example (not shown in the figure), the outlet area of ​​the first air outlet 2 is larger than that of the second air outlet 3, so that under the same outlet airflow, the airflow velocity of the first air outlet 2 is less than that of the second air outlet 3.

[0048] In some embodiments, the wind field structure includes a rectification structure (not shown in the figure), at least one of the first air outlet 2, the second air outlet 3 and the air intake 4 is provided with a rectification structure, the rectification structure is used to maintain the stability of the airflow, for example, the rectification structure is a mesh structure with multiple air holes.

[0049] In some embodiments, the wind field structure includes a flow guiding structure (not shown in the figure), at least one of the first air outlet 2, the second air outlet 3 and the air intake 4 is provided with a flow guiding structure, which is used to adjust the airflow direction. For example, the flow guiding structure is a guide plate.

[0050] This embodiment uses a rectifying structure and / or a guiding structure in at least one of the first air outlet 2, the second air outlet 3, and the air intake 4 to ensure the relative stability of the vortex airflow formed inside the housing 1 and the bottom transverse airflow, which can be used to achieve large-format printing.

[0051] According to an exemplary embodiment of the present invention, such as Figure 4 As shown, this embodiment proposes a metal 3D printer. The metal 3D printer includes an airflow structure, a laser emitting device, and a powder bed 131 as described in any embodiment. The laser emitting device includes a laser 142 and a laser lens 141. The laser 142 is disposed inside the housing 1 and located at the top of the housing 1. The laser lens 141 covers the outside of the laser 142. The airflow blown out from the first air outlet 2 flows through the laser lens 141 to remove dust deposits on the laser lens 141. The powder bed 131 is vertically and vertically disposed at the bottom of the housing 1. The laser emitted by the laser 142 passes through the laser lens 141 and enters the powder bed 131. The airflow blown out from the second air outlet 3 flows through the powder bed 131 to prevent splatter generated during the printing process from falling into the powder bed 131. In this embodiment of the metal 3D printer, the protective airflow entering the airflow structure can form a stable airflow within the housing 1, enabling simultaneous cleaning of the top and bottom of the housing 1, meeting the requirements for high-quality printing.

[0052] In some implementations, such as Figure 4As shown, the metal 3D printer also includes a first air inlet pipe 6, a second air inlet pipe 7, and an air outlet pipe 8. The air inlet end of the air outlet pipe 8 is connected to the air intake port 4, and the air outlet end of the air outlet pipe 8 is connected to the air inlet ends of the first air inlet pipe 6 and the second air inlet pipe 7, respectively. The air outlet end of the first air inlet pipe 6 is connected to the first air outlet 2, and the air outlet end of the second air inlet pipe 7 is connected to the second air outlet 3. A filter device 9 and an air supply device 10 are provided on the air outlet pipe 8. The connections between the first air inlet pipe 6 and the first air outlet 2, between the second air inlet pipe 7 and the second air outlet 3, and between the air intake port 4 and the air outlet pipe 8 are all sealed to prevent leakage of splashes inside the housing 1. The filter device 9 is, for example, a circulating filter, used to filter splashes and dust. The air supply device 10 is, for example, a fan, used to provide power for the flow of protective air within the housing 1. Under the action of the air supply device 10, the protective airflow and splashes inside the housing 1 enter the air outlet pipe 8 through the air inlet 4, and then, after the splashes are filtered out by the filter device 9, they enter the first air inlet pipe 6 and the second air inlet pipe 7. They then enter the housing 1 through the first air outlet 2 and the second air outlet 3 respectively, thus realizing the circulation of the protective airflow. The airflow direction of the protective airflow inside the housing 1 is referenced. Figure 4 The direction indicated by the middle arrow.

[0053] The following section, in conjunction with the accompanying drawings, details the airflow paths of the blower and suction inlets at different locations on the housing.

[0054] Figures 5a-5b This diagram illustrates an airflow path in a wind field structure with a blower and an intake on opposite sides of the bottom of the housing, with the blower and intake designed to be opposite each other. (Refer to...) Figures 5a-5b In this airflow structure, when the airflow velocity at the nozzle is low, the airflow velocity at the bottom is insufficient. Splashes and dust may, to some extent, break free from the bottom transverse airflow and move upwards, thus adhering to the laser lens and ultimately affecting the print quality, as shown in Figure 5(a). As shown in Figure 5(b), as the airflow velocity at the nozzle increases, due to the Bernoulli effect, the furthest stable distance that the bottom transverse airflow can reach gradually decreases, and upward flow separation and vortex generation easily occur, making it difficult to form a stable airflow field within the housing. Splashes may, to some extent, fall into the powder bed, affecting the print quality. (Airflow path reference...) Figures 5a-5b The direction indicated by the black dashed arrow in the middle.

[0055] Figures 6a-6c This diagram illustrates an airflow path for an airflow field structure with two air outlets positioned vertically on the same side of the housing. The air inlet and the lower air outlet are designed to be opposite each other. (Refer to...) Figures 6a-6cThis type of wind field structure is insufficient to remove the soot deposited on the laser lens when the airflow velocity at the upper nozzle is low. At higher airflow velocities, competition on the same side disrupts the airflow field within the entire casing, making the bottom lateral airflow unstable and causing the direction and structure of the upper and middle vortices to constantly change. As shown in Figure 6(a), under the Coanda effect (fluid flowing along a wall), the airflow from the two nozzles tends to flow along the wall and converges at a certain point, forming a competitive relationship. Under this competitive relationship, the direction and structure of the airflow vortices within the casing will constantly change. The airflow field within the casing may exhibit the structure shown in Figure 6(b), forming two vortices on the left and right sides, with the splashed particles moving upwards and then falling back into the powder bed under gravity; similarly, it may exhibit the structure shown in Figure 6(c), with the splashed particles moving towards the lower nozzle, and the airflow path referring to... Figures 6a-6c The direction indicated by the black dashed arrow in the middle.

[0056] Figure 7 The airflow path of the wind field structure in this embodiment is shown, with reference to... Figure 7 In this embodiment, the airflow structure features the first air outlet 2 and the second air outlet 3 on opposite sides, and the suction outlet 4 is positioned vertically opposite the first air outlet 2. This eliminates competition between airflows on the same side, creating a relatively stable transverse airflow at the bottom and a relatively stable vortex airflow in the middle of the printing cavity. The combined effect of the transverse and vortex airflow achieves better efficiency in removing splashes and dust. The airflow path is referenced... Figure 7 The direction indicated by the black dashed arrow in the middle.

[0057] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A metal 3D printer, characterized in that, The metal 3D printer includes an airflow structure, which includes a housing. A printing cavity is formed inside the housing. The housing includes a first side and a second side, which are arranged opposite to each other. A first air outlet is provided at the lower part of the first side, a second air outlet is provided at the upper part of the second side, and an air intake is provided at the lower part of the second side. The position of the air intake is not higher than the position of the first air outlet, so as to form a stable vortex airflow in the printing cavity and a stable lateral airflow at the bottom of the printing cavity. The wind field structure includes a protrusion, which is disposed on the second side. A cavity is formed inside the protrusion, and the printing cavity communicates with the cavity. The protrusion includes a first protrusion and a second protrusion connected to each other. The first protrusion is located above the second protrusion, and the air intake is disposed on the second protrusion. The housing includes a bottom surface, the bottom of the second protrusion is higher than the bottom surface, and the bottom of the second protrusion and the bottom surface form a stepped structure; The air outlet area of ​​the first air outlet is larger than that of the second air outlet; The wind field structure is configured such that the outlet velocity of the protective airflow entering the housing through the first air outlet is less than the outlet velocity of the airflow entering the housing through the second air outlet. The metal 3D printer also includes: A laser emitting device, comprising a laser and a laser lens, wherein the laser is disposed inside the housing and located at the top of the housing, and the laser lens covers the outside of the laser, and the airflow blown out by the first air outlet flows through the laser lens; A powder bed is provided, which is vertically and flexibly disposed at the bottom of the housing. The laser emitted by the laser is directed onto the powder bed through the laser lens, and the airflow blown out by the second air outlet flows through the powder bed.

2. The metal 3D printer according to claim 1, characterized in that, The first air outlet extends along the width direction of the first side surface; And / or, the second air outlet and the air inlet extend along the width direction of the second side.

3. The metal 3D printer according to claim 2, characterized in that, The wind field structure also includes an air volume regulating device, and at least one of the first air outlet and the second air outlet is provided with the air volume regulating device.

4. The metal 3D printer according to any one of claims 1-3, characterized in that, The wind field structure also includes a rectification structure, and at least one of the first air outlet, the second air outlet and the air intake is provided with the rectification structure; And / or, the wind field structure further includes a flow guiding structure, and at least one of the first air outlet, the second air outlet and the air intake is provided with the flow guiding structure.

5. The metal 3D printer according to claim 1, characterized in that, The metal 3D printer further includes a first air inlet pipe, a second air inlet pipe, and an air outlet pipe. The air inlet end of the air outlet pipe is connected to the air intake of the air field structure, and the air outlet end of the air outlet pipe is connected to the air inlet ends of the first air inlet pipe and the second air inlet pipe, respectively. The air outlet end of the first air inlet pipe is connected to the first air outlet, and the air outlet end of the second air inlet pipe is connected to the second air outlet. A filter device and an air supply device are provided on the air outlet pipe.

Images