Airflow distribution system of additive manufacturing equipment

Abstract

The invention discloses an airflow distribution system of additive manufacturing equipment, which is suitable for selective laser melting forming equipment and comprises a first air inlet part, a second air inlet part and an air outlet part. The first air inlet part and the second air inlet part are arranged on the same side of the forming cabin, and the first air inlet part is arranged on the upper side of the second air inlet part. The first air inlet part is configured to output first upper-layer airflow and first lower-layer airflow into the forming cabin, and the air speed of the first upper-layer airflow is larger than that of the first lower-layer airflow. The second air inlet part is configured to output second upper-layer airflow and second lower-layer airflow into the forming cabin, and the air speed of the second upper-layer airflow is smaller than that of the second lower-layer airflow. The wind speed of the second lower-layer airflow is larger than that of the first lower-layer airflow. The gas outlet part is used for receiving gas in the forming cabin and outflow of gas carrying substances. The wind speeds of the first upper-layer airflow, the first lower-layer airflow, the second upper-layer airflow and the second lower-layer airflow all refer to the average wind speed when the airflow just enters the forming cabin.

Description

Technical Field

[0001] This invention belongs to the field of additive manufacturing, and particularly relates to an airflow distribution system for additive manufacturing equipment. Background Technology

[0002] In additive manufacturing processes such as selective laser melting (SLM), high-energy lasers instantly melt and evaporate metal powder, generating large amounts of metal fumes and spatter. To protect optical lenses and remove contaminants, a protective gas flow must be maintained within the equipment's forming chamber. Traditional airflow organization schemes typically employ single inlets or simple zoned air intake methods, which easily create complex vortices and swirling phenomena within the chamber, such as... Figure 1 As shown. Airflow recirculation can cause smoke and high-temperature spatter that have been carried away from the printing area to settle or flow back to the processing area, causing multiple hazards: First, it contaminates the laser window, affecting the stability of beam energy transmission; second, spatter falls into the unmelted powder bed or the formed layer, forming inclusion defects and reducing the density and mechanical properties of the parts; third, it disturbs the gas environment near the molten pool, affecting the stability of the forming process.

[0003] While existing technologies offer methods to improve airflow by increasing wind speed or modifying vent layout, achieving a balance between multiple objectives—such as efficient smoke extraction, lens protection, preventing powder blowing, and suppressing backflow—is often challenging. Simply increasing wind speed may disperse the powder bed, while complex active airflow control increases system cost and complexity. Therefore, how to construct a stable, uniform, and backflow-free quasi-laminar airflow within the forming chamber, while maintaining a simple structure and controllable energy consumption, is a pressing technical problem that needs to be solved in this field. Summary of the Invention

[0004] This invention provides an airflow distribution system for additive manufacturing equipment, which fundamentally suppresses airflow recirculation and eddies through differentiated wind speed distribution, ensuring the directional and efficient discharge of smoke and dust.

[0005] The technical solution of this invention is as follows: An airflow distribution system for additive manufacturing equipment, applicable to laser selective melting forming equipment, the airflow distribution system includes a first air inlet, a second air inlet, and an air outlet; the first air inlet and the second air inlet are located on the same side of the forming chamber, and the first air inlet is located above the second air inlet; The first air intake is configured to output a first upper airflow and a first lower airflow into the molding chamber, wherein the wind speed of the first upper airflow is greater than the wind speed of the first lower airflow. The second air intake is configured to output a second upper airflow and a second lower airflow into the molding chamber, wherein the wind speed of the second upper airflow is less than the wind speed of the second lower airflow, and the wind speed of the second lower airflow is greater than the wind speed of the first lower airflow. The gas outlet is used to receive the gas inside the molding chamber and the gas-carrying substances flowing out. The wind speeds of the first upper airflow, the first lower airflow, the second upper airflow, and the second lower airflow all refer to the average wind speed when the airflow first enters the forming chamber.

[0006] In a preferred embodiment of the additive manufacturing equipment's airflow distribution system, the first upper airflow passes through a region of at least 10 to 30 millimeters directly below the optical lens inside the molding chamber; and / or, the second lower airflow passes through a region of at least 0 to 10 millimeters directly above the printing platform inside the molding chamber.

[0007] In a preferred embodiment of the additive manufacturing equipment airflow distribution system, the wind speed of the first upper airflow is 0.5 to 1 m / s; and / or, the wind speed of the first lower airflow is 0.2 to 0.4 m / s.

[0008] In a preferred embodiment of the additive manufacturing equipment airflow distribution system, the wind speed of the second upper airflow is 0.2 to 0.4 m / s; and / or, the wind speed of the second lower airflow is 1.2 to 1.6 m / s.

[0009] In a preferred embodiment of the additive manufacturing equipment airflow distribution system, there is a gap between the air outlet of the first lower airflow on the inner wall of the molding chamber and the air outlet of the second upper airflow on the inner wall of the molding chamber.

[0010] In a preferred embodiment of the airflow distribution system of an additive manufacturing equipment, the first air intake includes an air source interface and two air intake ducts. The input end of the air source interface is connected to and communicates with the output end of the fan of the additive manufacturing equipment. The input ends of the two air intake ducts are respectively connected to and communicate with the output end of the air source interface. The output ends of the two air intake ducts are respectively connected to the inner wall of the molding chamber to form air outlets on the inner wall of the molding chamber. The gas delivered by the fan enters the molding chamber from its respective air outlet through the two air intake ducts to form the first upper airflow and the first lower airflow.

[0011] In a preferred embodiment of the airflow distribution system of the additive manufacturing equipment, the second air intake includes an air source interface and two air intake ducts. The input end of the air source interface is connected to and communicates with the output end of the fan of the additive manufacturing equipment. The input ends of the two air intake ducts are respectively connected to and communicate with the output end of the air source interface. The output ends of the two air intake ducts are respectively connected to the inner wall of the molding chamber to form air outlets on the inner wall of the molding chamber. The gas delivered by the fan enters the molding chamber from its respective air outlet through the two air intake ducts to form the second upper airflow and the second lower airflow.

[0012] In a preferred embodiment of the additive manufacturing equipment, the airflow distribution system includes a throttling element at the input end of the air intake.

[0013] In the airflow distribution system of the additive manufacturing equipment provided in a preferred embodiment, the throttling elements provided on the input ends of the two air inlets are integral pieces, and / or the throttling elements are detachable.

[0014] In a preferred embodiment of the additive manufacturing equipment, the airflow distribution system includes at least one air intake duct comprising a serpentine mixing pipe section and a rectifier section connected in series along the airflow direction; the serpentine mixing pipe section is composed of a pipe with multiple bends, and the number of bends is not less than three.

[0015] Because the present invention adopts the above technical solution, it has the following advantages and positive effects compared with the prior art: The airflow distribution system of the additive manufacturing equipment provided by this invention forms a suppressive air curtain in the upper part of the forming chamber by a first upper airflow with a higher wind speed, thereby suppressing the vortexing caused by the rising hot airflow and protecting the optical lenses. The second lower airflow with an even higher wind speed directly and quickly captures and removes the smoke and splatter generated during the printing process. The arrangement of the first lower airflow and the second upper airflow fills the low-pressure area between the two main air fields (i.e., the air fields formed by the first upper airflow and the second lower airflow), improves the airflow uniformity of the downwind field (i.e., the air field formed by the second lower airflow) and suppresses the generation of vortices in the chamber when the airflow of the upwind field (i.e., the air field formed by the first upper airflow) flows downward, thereby effectively preventing the problem of poor printing effect caused by turbulence in the forming chamber. Attached Figure Description

[0016] 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.

[0017] Figure 1 This is a schematic diagram illustrating the airflow retraction and low-pressure zone within the forming chamber in existing technology. Figure 2 This is a schematic diagram of the overall structure of the airflow distribution system of an additive manufacturing equipment according to the present invention; Figure 3 This is a schematic cross-sectional view of the structure of a first air intake section according to the present invention; Figure 4 This is a schematic cross-sectional view of the structure of a second air intake section according to the present invention; Figure 5 This is a simulated velocity cloud map of the airflow velocity distribution inside the molding chamber corresponding to a specific embodiment of the present invention; Figure 6 This is a simulated velocity vector diagram of the airflow direction inside the molded cabin corresponding to a specific embodiment of the present invention; Figure 7 This is a simulated velocity cloud map showing the uniformity of airflow velocity in the lower wind field (i.e., the wind field corresponding to the second lower airflow) inside the molded cabin according to a specific embodiment of the present invention.

[0018] Explanation of reference numerals in the attached figures: 1: First air intake; 111: First upper air intake duct; 112: First upper air outlet; 113, 114: Circular grille; 121: First lower air intake duct; 122: First lower air outlet; 123, 124: Circular grille; 13: Throttling plate; 2: Second air intake section; 211: Second upper air intake duct; 212: Second upper air outlet; 213, 214: Circular grille; 215: Serpentine mixing pipe section; 221: Second lower air intake duct; 222: Second lower air outlet; 223, 224: Circular grille; 225: Serpentine mixing pipe section; 23: Throttling plate; 3: Vent section; 4: Molding compartment. Detailed Implementation

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without any creative effort.

[0020] To keep the drawings concise, only the parts relevant to the invention are shown schematically in each figure, and they do not represent the actual structure of the product. Furthermore, for ease of understanding, in some figures, only one of components with the same structure or function is shown schematically, or only one is labeled. In this document, "one" can mean not only "only one" but also "more than one".

[0021] In the description of this invention, the term "a" not only means "only one" but can also mean "more than one". The terms "first", "second", "third", etc., are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance. The terms "perpendicular" and "parallel" do not mean absolutely perpendicular or parallel, but can be approximately perpendicular or approximately parallel.

[0022] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0023] See Figures 2 to 4 This embodiment provides an airflow distribution system for additive manufacturing equipment, applicable to laser selective melting forming equipment. The airflow distribution system includes a first air inlet 1, a second air inlet 2, and an air outlet 3. The first air inlet 1 and the second air inlet 2 are located on the same side of the forming chamber 4, and the first air inlet 1 is located above the second air inlet 2.

[0024] The first air intake 1 is configured to output a first upper airflow and a first lower airflow into the forming chamber 4. The air outlet of the first upper airflow on the inner wall of the forming chamber 4 is located above the air outlet of the first lower airflow on the inner wall of the forming chamber 4, and the wind speed of the first upper airflow is greater than the wind speed of the first lower airflow. The wind speeds of the first upper airflow and the first lower airflow refer to their average wind speeds at the air outlets.

[0025] The first upper airflow is primarily used to form a suppressive air curtain in the upper part of the forming chamber 4, thereby suppressing the rewinding caused by the rising hot airflow and protecting the optical lens. Therefore, preferably, the first upper airflow passes through at least a 10-30 mm area directly below the optical lens within the forming chamber 4.

[0026] The wind speed of the first upper airflow is generally set to the critical wind speed that can carry away the black smoke. Preferably, the wind speed of the first upper airflow is 0.5 to 1 m / s. Of course, in actual situations, the wind speed of the first upper airflow can be selected according to the actual situation.

[0027] The second air intake 2 is configured to output a second upper airflow and a second lower airflow into the forming chamber 4. The air outlet of the second upper airflow on the inner wall of the forming chamber 4 is located above the air outlet of the second lower airflow on the inner wall of the forming chamber 4, and the wind speed of the second upper airflow is less than the wind speed of the second lower airflow. The wind speed of the second upper airflow and the wind speed of the second lower airflow both refer to their average wind speed at the air outlet.

[0028] The second lower airflow is primarily used to generate a directional, high-speed airflow near the printing platform to directly and quickly capture and remove smoke and splatter generated during the printing process. Therefore, preferably, the second lower airflow passes through at least a 0-10 mm area directly above the printing platform within the forming chamber 4.

[0029] The second lower-level airflow acts directly on the processing area near the laser molten pool, rapidly capturing and carrying away the black smoke and spatter generated by metal evaporation with high kinetic energy. Since the spatter particles are larger than the black smoke particles, a higher wind speed is often required. Therefore, the wind speed of the second lower-level airflow is set to be higher than that of the first lower-level airflow. Preferably, the wind speed of the second lower-level airflow is 1.2–1.6 m / s; of course, in actual situations, the wind speed of the second lower-level airflow can be selected according to the specific circumstances.

[0030] Since airflow moves from high-pressure areas to low-pressure areas, a low-speed airflow—the first lower airflow and the second upper airflow—is added between the first upper airflow and the second lower airflow to increase pressure and weaken vortex generation. In other words, the arrangement of the first lower airflow and the second upper airflow fills the low-pressure area between the two main wind fields (i.e., the wind field formed by the first upper airflow and the second lower airflow), improving the airflow uniformity of the downwind field (i.e., the wind field formed by the second lower airflow) and suppressing the generation of vortices within the chamber when the upwind field (i.e., the wind field formed by the first upper airflow) flows downwards. This effectively prevents the problem of turbulence in the forming chamber 4 causing poor printing results. Simultaneously, compared to using high-speed airflow, using low-speed airflow in the first lower airflow and the second upper airflow effectively reduces the power consumption of the fans in the additive manufacturing equipment. Preferably, the wind speed of the first lower airflow and the second upper airflow is 0.2–0.4 m / s.

[0031] Specifically, the first air intake 1 includes an air source interface and two air intake ducts. The input end of the air source interface is connected to and communicates with the output end of the blower of the additive manufacturing equipment. The input ends of the two air intake ducts are respectively connected to and communicate with the output ends of the air source interface. The output ends of the two air intake ducts are respectively connected to the inner wall of the molding chamber 4 to form air outlets on the inner wall of the molding chamber 4. The gas delivered by the blower enters the molding chamber 4 through the two air intake ducts and their respective air outlets to form a first upper airflow and a first lower airflow. For easy distinction, the air intake duct and air outlet corresponding to the first upper airflow are respectively the first upper air intake duct 111 and the first upper air outlet 112; the air intake duct and air outlet corresponding to the first lower airflow are respectively the first lower air intake duct 121 and the first lower air outlet 122.

[0032] The second air intake 2 includes an air source interface and two air intake ducts. The input end of the air source interface is connected to and communicates with the output end of the blower of the additive manufacturing equipment. The input ends of the two air intake ducts are respectively connected to and communicate with the output ends of the air source interface. The output ends of the two air intake ducts are respectively connected to the inner wall of the molding chamber 4 to form air outlets on the inner wall of the molding chamber 4. The gas delivered by the blower enters the molding chamber 4 through the two air intake ducts and their respective air outlets to form a second upper airflow and a second lower airflow. For easy distinction, the air intake duct and air outlet corresponding to the second upper airflow are the second upper air intake duct 211 and the second upper air outlet 212, respectively; the air intake duct and air outlet corresponding to the second lower airflow are the second lower air intake duct 221 and the second lower air outlet 222, respectively.

[0033] Preferably, the first upper air outlet 112 and the first lower air outlet 122 are located in the upper region of the molding chamber 4. The first upper air outlet 112 is located at the top of the molding chamber 4 near the optical lens to form a protective airflow against the wall using the Coanda effect. The second upper air outlet 212 and the second lower air outlet 222 are located in the lower region of the molding chamber 4. The upper edge of the second lower air outlet 222 is located between 10 mm and 20 mm above the working surface of the printing platform.

[0034] The exhaust section 3 is used to receive the gas and gas-carrying substances (such as splatter and black smoke generated during printing) flowing out of the molding chamber 4. The input end of the exhaust section 3 is located on the inner wall of the molding chamber 4 to form an exhaust port on the inner wall of the molding chamber 4. The exhaust port is located on the top or side wall of the molding chamber 4, and its total effective flow area is not less than the total area of ​​all exhaust ports (including the first upper exhaust port 112, the first lower exhaust port 122, the second upper exhaust port 212, and the second lower exhaust port 222) to ensure smooth airflow and avoid pressure buildup inside the chamber. In order to ensure effective capture of splatter while avoiding blowing away the powder bed, the exhaust port is located on the side wall of the molding chamber 4 opposite to the second lower exhaust port 222.

[0035] Furthermore, there is a gap between the air outlet (i.e., the first lower air outlet 122) on the inner wall of the first lower airflow and the air outlet (i.e., the second upper air outlet 212) on the inner wall of the second upper airflow.

[0036] Furthermore, the input end of the air intake is equipped with a throttling element. By setting the throttling element on the input end of each air intake, when the air source interfaces corresponding to the first air intake 1 and the second air intake 2 are connected to the fan system of the additive manufacturing equipment, the setting of the throttling element can enable the same fan output power to obtain different wind speeds of the first upper airflow, the first lower airflow, the second upper airflow, and the second lower airflow.

[0037] The throttling element can be an orifice plate, a fixed damping mesh, or a duct section with a specific cross-section, etc. The throttling elements provided on the input ends of the two air intakes in the first air intake 1 can be an integral piece (of course, they can also be set separately in other embodiments), and the throttling elements provided on the input ends of the two air intakes in the second air intake 2 can be an integral piece (of course, they can also be set separately in other embodiments).

[0038] Depending on the printing material and printing shape, the wind speeds of the first upper airflow, the first lower airflow, the second upper airflow, and the second lower airflow can be selected differently, and the wind speed ratios between them may vary. Therefore, the throttling element is preferably designed to be detachable, and the detachable connection method can be a snap-fit ​​connection, a threaded fastener connection, or the like.

[0039] Traditional straight-line air intake structures, when the airflow velocity is high, exhibit excessively large standard deviations in the uniformity of airflow velocity distribution at the outlet, potentially leading to insufficient airflow velocity after entering the forming chamber 4. Therefore, preferably, the second lower-level air intake 221 (or other air intakes or multiple air intakes in other embodiments) comprises a serpentine mixing section and a rectifying section connected sequentially along the airflow direction; the serpentine mixing section consists of a pipe with multiple bends, with at least three bends. More preferably, the serpentine mixing section consists of a pipe exhibiting continuous S-shaped bends. Through the Dean vortex effect, the serpentine mixing section induces intense lateral momentum exchange and mixing of the airflow within the pipe cross-section, effectively homogenizing the airflow from the inlet and initially weakening large-scale turbulent fluctuations. The airflow then enters the rectifying section, where it is transformed into a stable, uniform laminar or quasi-laminar flow field perpendicular to the outlet surface (the outlet surface being the outlet end cross-section of the rectifying section).

[0040] The airflow distribution system of the additive manufacturing equipment provided in this embodiment completely eliminates vortex formation and eddies. Through a specific airflow ratio of "high speed in the first upper layer airflow and low speed in the first lower layer airflow of the first air intake 1, and low speed in the second upper layer airflow and high speed in the second lower layer airflow of the second air intake 2," the vortex formation of the updraft field (i.e., the wind field formed by the first upper layer airflow) within the chamber is eliminated from a physical structural perspective, thus disrupting the conditions for eddy formation. The high-speed first upper layer airflow output from the first air intake 1 suppresses the rising airflow, and the high-speed second lower layer airflow in the second air intake 2 dominates the horizontal flow, resulting in clear streamlines within the forming chamber 4 pointing towards the air outlet. Figure 5 , Figure 6 As shown, it effectively solved the problem. Figure 1 The low-pressure rewinding problem in the traditional solution shown.

[0041] The airflow distribution system of the additive manufacturing equipment provided in this embodiment achieves excellent uniformity of the wind field formed by the second lower airflow. The movement of the first upper and lower airflows easily affects the airflow below, while the second upper airflow, acting as a protective layer for the second lower airflow, prevents the movement of the first upper and lower airflows from affecting the second lower airflow, thus avoiding the phenomenon of uneven wind speed in critical areas caused by the traditional upper wind field affecting the lower wind field. Combined with an optimized wind speed ratio, this results in an extremely uniform airflow velocity distribution in the critical area directly above the printing area—the 0-10 mm region directly above the printing platform. Figure 7 As shown, a stable gas environment is provided for the molten pool, which significantly improves the consistency of the printed layer quality.

[0042] The airflow distribution system of the additive manufacturing equipment provided in this embodiment has a simple and reliable structure. The core airflow ratio is achieved through a fixed mechanical structure inside the air duct—a throttling element. It eliminates the need for complex sensors, controllers, and regulating valves, resulting in high system reliability, low manufacturing cost, and stable performance unaffected by control delays or disturbances.

[0043] The airflow distribution system for the additive manufacturing equipment provided in this embodiment achieves both high efficiency and energy saving. The differentiated wind speed configuration precisely targets the high-speed airflow to the areas that require it most (upper protection and lower cleaning), avoiding the energy waste of high-speed airflow throughout the entire chamber.

[0044] The following provides a specific configuration of the airflow distribution system for an additive manufacturing apparatus (it should be noted that the configuration provided here is an example of a feasible solution and not a limitation thereof).

[0045] like Figure 2 As shown, the airflow distribution system is applied to a laser selective melting forming device. The forming chamber 4 is a sealed chamber with a first air inlet installed on the upper part of its right side wall, a second air inlet installed on the lower part, and an air outlet at the bottom of its left side wall.

[0046] like Figure 3 As shown, the first air intake is divided into two independent air intakes—an upper air intake 111 and a lower air intake 121—by a partition component. The upper air outlet 112 of the upper air intake 111 and the lower air outlet 122 of the lower air intake 121 are both elongated air outlets. The upper and lower air intakes 111 and 121 are each equipped with two circular grid plates 113, 114, 123, and 124 of different apertures to rectify the airflow. A throttling plate 13 is also installed inside the first air intake. When airflow from the fan passes through, a speed difference is naturally created due to the different throttling areas of the upper and lower air intakes 111 and 121. The designed wind speed for the upper airflow is 0.8 m / s, and the designed wind speed for the lower airflow is 0.3 m / s. The height of the first upper air outlet 112 is 40 mm, the height of the first lower air outlet 122 is 100 mm, and the total height of the air outlets in the first air intake is 140 mm.

[0047] like Figure 4 As shown, the second air intake adopts a similar layered structure, forming a second upper air intake 211 and a second lower air intake 221, with corresponding second upper air outlet 212 and second lower air outlet 222. A throttling plate 23 is also installed inside the second air intake. When airflow from the fan passes through, a wind speed difference is naturally formed due to the different throttling areas of the second upper air intake 211 and the second lower air intake 221. The wind speed of the second lower airflow is designed to be 1.4 m / s, and the wind speed of the second upper airflow is designed to be 0.3 m / s. The lower edge of the second lower air outlet 222 is approximately 10 mm from the printing platform, and the air outlet height of the second lower air outlet 222 is 50 mm. Furthermore, both the second upper air intake 211 and the second lower air intake 221 include serpentine mixing pipe sections 215 and 225 connected in series along the airflow direction, and a rectifier section. The rectifier section is equipped with two circular grid plates 213, 214, 223, and 224 with different apertures to rectify the airflow. When the airflow distribution system is working, protective gas (such as argon) is transported by the fan and enters the first air intake and the second air intake respectively. According to the internal throttling plate, it is automatically distributed to a preset differentiated air speed and sent into the forming chamber 4 from their respective air outlets.

[0048] The high-speed airflow from the first upper air outlet 112 forms a downward-sloping pressure curtain near the top of the forming chamber 4, effectively suppressing the vertical upward trend of hot air in the processing area and guiding it out of the outlet direction, while continuously cleaning the optical lenses.

[0049] The high-speed second lower airflow output from the second lower air outlet 222 closely adheres to the printing surface, using high kinetic energy to quickly "push" the smoke and splatter generated by laser melting away from the molten pool area, and transports them horizontally to achieve cleaning.

[0050] The low-speed first lower-level airflow output from the first lower-level air outlet 122 and the low-speed second upper-level airflow output from the second upper-level air outlet 212 play a "filling" and "buffering" role between the two main airflows (i.e., the first upper-level airflow and the second lower-level airflow), making the velocity vector direction of the entire flow field tend to be consistent and avoiding the generation of new eddies due to velocity shear.

[0051] Through the aforementioned synergistic effect, a highly uniform quasi-laminar airflow field is formed throughout the entire molding chamber 4, especially in the processing area above the printing platform, flowing smoothly from the right side (air inlet side) of the equipment to the left side (air outlet side).

[0052] Based on the airflow distribution system settings of the specific additive manufacturing equipment described above, a simulation diagram was obtained. Figures 5 to 7 ). Figure 5 The simulated velocity cloud map shows that the velocity distribution inside the molding chamber is continuous and the gradient is gentle, with no local high-speed jet core area or obvious low-speed stagnation area. Figure 6 The simulated velocity vector diagram clearly shows that all streamlines point towards the exhaust port, with a consistent flow direction, completely eliminating issues such as... Figure 1 The backflow and eddy current phenomena are shown. Figure 7 A velocity cloud map was specifically extracted from the 50mm height range directly above the printed area, and the results showed that the velocity uniformity in this area was excellent.

[0053] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, if these changes fall within the scope of the claims of the present invention and their equivalents, they shall still fall within the protection scope of the present invention.

Claims

1. An airflow distribution system for additive manufacturing equipment, characterized in that, Applicable to laser selective melting forming equipment, the airflow distribution system includes a first air inlet, a second air inlet, and an air outlet; the first air inlet and the second air inlet are located on the same side of the forming chamber, and the first air inlet is located above the second air inlet; The first air intake is configured to output a first upper airflow and a first lower airflow into the molding chamber, wherein the wind speed of the first upper airflow is greater than the wind speed of the first lower airflow. The second air intake is configured to output a second upper airflow and a second lower airflow into the molding chamber, wherein the wind speed of the second upper airflow is less than the wind speed of the second lower airflow, and the wind speed of the second lower airflow is greater than the wind speed of the first lower airflow. The gas outlet is used to receive the gas inside the molding chamber and the gas-carrying substances flowing out. The wind speeds of the first upper airflow, the first lower airflow, the second upper airflow, and the second lower airflow all refer to the average wind speed when the airflow first enters the forming chamber.

2. The airflow distribution system of the additive manufacturing equipment according to claim 1, characterized in that, The first upper airflow passes through a region of at least 10 to 30 millimeters directly below the optical lens inside the molding chamber; and / or, the second lower airflow passes through a region of at least 0 to 10 millimeters directly above the printing platform inside the molding chamber.

3. The airflow distribution system of the additive manufacturing equipment according to claim 1, characterized in that, The wind speed of the first upper airflow is 0.5 to 1 m / s; and / or, the wind speed of the first lower airflow is 0.2 to 0.4 m / s.

4. The airflow distribution system of the additive manufacturing equipment according to claim 1, characterized in that, The wind speed of the second upper airflow is 0.2 to 0.4 m / s; and / or, the wind speed of the second lower airflow is 1.2 to 1.6 m / s.

5. The airflow distribution system of the additive manufacturing equipment according to claim 1, characterized in that, There is a gap between the air outlet of the first lower airflow on the inner wall of the molding chamber and the air outlet of the second upper airflow on the inner wall of the molding chamber.

6. The airflow distribution system of the additive manufacturing equipment according to claim 1, characterized in that, The first air intake includes an air source interface and two air intake ducts. The input end of the air source interface is connected to and communicates with the output end of the fan of the additive manufacturing equipment. The input ends of the two air intake ducts are respectively connected to and communicate with the output end of the air source interface. The output ends of the two air intake ducts are respectively connected to the inner wall of the molding chamber to form air outlets on the inner wall of the molding chamber. The gas delivered by the fan enters the molding chamber through the two air intake ducts and their respective air outlets to form the first upper airflow and the first lower airflow.

7. The airflow distribution system of the additive manufacturing equipment according to claim 1, characterized in that, The second air intake includes an air source interface and two air intake ducts. The input end of the air source interface is connected to and communicates with the output end of the fan of the additive manufacturing equipment. The input ends of the two air intake ducts are respectively connected to and communicate with the output end of the air source interface. The output ends of the two air intake ducts are respectively connected to the inner wall of the molding chamber to form air outlets on the inner wall of the molding chamber. The gas delivered by the fan enters the molding chamber through the two air intake ducts and their respective air outlets to form the second upper airflow and the second lower airflow.

8. The airflow distribution system of the additive manufacturing equipment according to claim 6 or 7, characterized in that, The intake port is equipped with a throttling element.

9. The airflow distribution system of the additive manufacturing equipment according to claim 8, characterized in that, The throttling elements provided on the input ends of the two air intakes are integral pieces, and / or the throttling elements are detachable.

10. The airflow distribution system of the additive manufacturing equipment according to claim 6 or 7, characterized in that, At least one of the air intakes includes a serpentine mixing section and a rectifier section connected in series along the airflow direction; the serpentine mixing section is composed of a pipe with multiple bends, and the number of bends is not less than three.

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