Wind field system with uniform airflow distribution for additive manufacturing large-breadth forming platform

Abstract

The invention relates to the technical field of additive manufacturing, in particular to an air field system with uniform airflow distribution for an additive manufacturing large-breadth forming platform, which comprises an air inlet three-way pipe unit and a negative pressure air draft unit, the air inlet three-way pipe unit comprises a main air supply pipe, an upper air outlet pipe and a lower air outlet pipe; the upper air outlet pipe and the lower air outlet pipe are each internally provided with a flow dividing grating assembly, air outlets of the upper air outlet pipe and the lower air outlet pipe are divided into a plurality of sub air outlets with the same opening size through the flow dividing grating assemblies, and flow guide pipes are arranged at the air outlets of the upper air outlet pipe and the lower air outlet pipe. An airflow dispersion unit is arranged on the side, close to the sub air outlets, in the flow guide pipe, a linear air outlet hole is formed in the other side of the flow guide pipe, and a conical flow channel with a conical section is arranged between the airflow dispersion unit and the linear air outlet hole. By means of the multi-stage flow dividing and guiding design, the effect that airflow in all areas of the large-breadth forming platform is evenly distributed under the condition of low air volume is achieved.

Description

Technical Field

[0001] The present application relates to the field of additive manufacturing technology, and in particular to a wind field system with uniform airflow distribution for an additive manufacturing large-format forming platform. Background Art

[0002] Selective laser melting (SLM) technology in additive manufacturing is increasingly being used in industrial production. As print formats expand and layer thicknesses increase, controlling the airflow within the build chamber has become a key bottleneck restricting the development of SLM technology. For this technology, the ideal airflow within the build chamber requires uniform coverage of the entire build platform. This requires ensuring that airflow can promptly remove smoke and splashes generated during the printing process while also maintaining a stable thermal field to prevent thermal stress and deformation in printed parts due to uneven heat dissipation.

[0003] In order to achieve the requirements of an ideal wind field, the existing technology usually adopts a single high-speed airflow circulation mode, that is, by introducing high-speed airflow and increasing the air volume to increase the airflow coverage range, and at the same time adding a heat exchanger in the middle of the wind field pipe to cool the pipe temperature and prevent the temperature of the laser and galvanometer from rising. However, in actual use, it was found that the use of a single high-speed airflow circulation mode is difficult to ensure the uniformity of the airflow on the large-format forming platform, and it is difficult to cover the large-format printing platform. It is easy to cause smoke and flying debris to remain, affecting the printing quality. At the same time, the high-speed airflow is easy to cause the filter element to clog, resulting in an increase in the number of backwash cleaning operations and reducing the service life of the filter element. Moreover, the high air volume airflow is easy to cause the wind field bend pipe to vibrate and the temperature to rise, which in turn causes the overall temperature in the forming chamber to rise, affecting the cooling control of the laser and galvanometer. Even if a heat exchanger is added to cool the pipe, it cannot fundamentally solve the above problems. In addition, the addition of a heat exchanger also increases the complexity of the system and production costs.

[0004] Therefore, there is an urgent need for a wind field structure that can ensure the uniformity and stability of the air flow in the wind field during large-format printing platforms and large-layer sintering scanning, while reducing the flow rate of the air flow to increase the service life of the filter element and reduce the temperature rise rate in the molding chamber. Summary of the Invention

[0005] In order to achieve the purpose of reducing the airflow rate while ensuring the uniformity and stability of the airflow in the wind field of a large-format printing platform, the present application provides a wind field system with uniform airflow distribution for an additive manufacturing large-format forming platform.

[0006] This application provides a wind field system with uniform airflow distribution for a large-format additive manufacturing forming platform, which adopts the following technical solutions: A wind field system with uniform airflow distribution for an additive manufacturing large-format forming platform includes an air inlet three-way pipe unit and a negative pressure exhaust unit. The air inlet three-way pipe unit includes a main air supply pipe, an upper air outlet pipe and a lower air outlet pipe. The connection between the main air supply pipe and the upper air outlet pipe and the lower air outlet pipe is arranged in an arc transition, and the connection opening size of the upper air outlet pipe and the main air supply pipe is smaller than the connection opening size of the lower air outlet pipe and the main air supply pipe. A diverter grille assembly is provided in both the upper air outlet pipe and the lower air outlet pipe. The diverter grille assembly The air outlets of the upper air outlet duct and the lower air outlet duct are divided into a plurality of sub-air outlets of the same opening size, and the air outlets of the upper air outlet duct and the lower air outlet duct are both provided with a guide pipe, an air flow dispersion unit is provided on one side of the guide pipe close to the sub-air outlet, and a plurality of linear air outlet holes distributed in an array are formed on the other side of the guide pipe, and the air flow channel between the air flow dispersion unit and the linear air outlet holes is configured as a tapered flow channel with a tapered cross-section, and the end of the tapered flow channel with a smaller opening is arranged toward the linear air outlet hole; The airflow dispersion unit is used to disperse the inertial airflow flowing out of the sub-outlet and redistribute it so that it is evenly distributed in the conical flow channel. The conical flow channel is used to compress and accelerate the dispersed airflow and then introduce it into the linear air outlet, and through the linear air outlet, it is respectively transported to the laser lens protection area and the molding platform protection area to form the lens protection airflow and the printing area protection airflow. The negative pressure exhaust unit is used to extract the lens protection airflow and the printing area protection airflow at negative pressure and re-converge them to guide the cyclone separator for filtration and recovery.

[0007] By adopting the above technical solution, with the cooperation of the air inlet three-way pipe unit, the diversion grille assembly, the airflow dispersion unit, the tapered flow channel and the straight air outlet, the total airflow generated by the fan is diverted, broken up, redistributed and guided at multiple levels, thereby achieving uniform distribution of airflow in various areas of the large-format forming platform, effectively preventing the accumulation of smoke and splashing, and improving printing quality. At the same time, it also achieves the effect of high-speed flow in the printing platform area with a small air volume, reducing the fan speed requirement, thereby effectively reducing the fan energy consumption and filter element load, and avoiding the fan bend vibration and overheating problems caused by large air volume, thereby improving the equipment operation stability.

[0008] Preferably, the diversion grille assembly includes a horizontal grille plate, a vertical grille plate and a first arc-shaped guide plate, and a plurality of first arc-shaped guide plates are provided, and the plurality of first arc-shaped guide plates are distributed at intervals on both sides of the vertical grille plate, and a second arc-shaped guide plate is provided between two adjacent first arc-shaped guide plates, and the lengths and curvatures of the plurality of second arc-shaped guide plates are different.

[0009] By adopting the above technical solution, when in use, the airflow delivered by the circular air inlet of the main air supply duct needs to be redistributed to cover the entire rectangular platform area, and the airflow must turn during the flow process under the guidance of the arc structure of the upper air outlet duct and the lower air outlet duct. Due to the influence of the flow inertia of the airflow, the directly turned airflow is easy to converge into a beam and flow concentrated in a certain area, resulting in difficulty in achieving uniform distribution of the airflow. With the cooperation of the horizontal grille plate, the vertical grille plate, the first arc guide plate and the second arc guide plate, the airflow delivered by the main air supply duct is initially distributed and its flow direction is guided so that it is more evenly divided into multiple airflows and flows out from multiple sub-air outlets with the same opening size, thereby improving the uniformity of the airflow distribution at the air outlets of the upper air outlet duct and the lower air outlet duct.

[0010] Preferably, the air flow dispersion unit includes several groups of triangular hollow plates arranged in a linear array, and two adjacent groups of triangular hollow plates are fixedly connected. The triangular hollow plates include a first vertical inclined plate and a second vertical inclined plate, and the first vertical inclined plate is fixedly connected to one end of the sub-air outlet and the second vertical inclined plate is fixedly connected to one end of the sub-air outlet. There is an angle between the first vertical inclined plate and the second vertical inclined plate, and hollow holes are provided on the first vertical inclined plate and the second vertical inclined plate. Part of the linear inertial airflow flowing out of the sub-air outlet is deflected under the action of the inclined surfaces of the first vertical inclined plate and the second vertical inclined plate, and the other part of the airflow passes directly through the hollow holes.

[0011] By adopting the above technical solution, when in use, under the guidance of the arc structure of the upper air outlet duct, the lower air outlet duct, the first arc guide plate and the second arc guide plate, the air flow flows in an arc shape as a whole. Affected by the flow inertia, the airflow of a single flow channel is easily converged to one side to form a straight inertial airflow, and then flows out from the sub-air outlet. The area with less airflow distribution in the flow channel is prone to form vortex phenomenon. Therefore, the inclined surface reflection effect of the first vertical inclined plate and the second vertical inclined plate is used to deflect part of the straight inertial airflow flowing out of the sub-air outlet. At the same time, the setting of the hollow hole allows part of the airflow to pass directly, so that the straight inertial airflow in the corresponding area of ​​the airflow dispersion unit is redistributed, so that the airflow in this area is evenly dispersed in the flow channel, while also suppressing the generation of vortex phenomenon, ensuring the subsequent uniform flow of the airflow.

[0012] Preferably, a reinforcing rib is connected between the first vertical inclined plate and the second vertical inclined plate adjacent thereto.

[0013] By adopting the above technical solution, when in use, the connection structural strength of the first vertical inclined plate and the second vertical inclined plate is increased by reinforcing ribs, and at the same time, several groups of airflow dispersion units are connected into a whole, thereby reducing the probability of overall deformation of the airflow dispersion unit after the airflow is introduced.

[0014] Preferably, the size of the hollow holes located at both ends of the airflow dispersion unit is larger than the size of the hollow hole located in the middle of the airflow dispersion unit.

[0015] By adopting the above technical solution, when in use, since the middle flow rate of the air flow out of the sub-outlet is greater than the flow rate on both sides, the flow rate of the air flow directly passing through the larger hollow holes on both sides is increased, and at the same time, the amount of air flow reflected by the inclined surfaces of the first vertical inclined plate and the second vertical inclined plate is reduced, thereby ensuring the effect of the air flow dispersion unit breaking up and redistributing the air flow out of the sub-outlet.

[0016] Preferably, the negative pressure exhaust unit includes an upper exhaust duct, a lower exhaust duct and a negative pressure three-way pipe, the air inlet of the upper exhaust duct is corresponding to the air outlet of the upper air outlet duct, the air inlet of the lower exhaust duct is corresponding to the air outlet of the lower air outlet duct, the air outlet of the upper exhaust duct and the air outlet of the lower exhaust duct are respectively connected to the two air inlets of the negative pressure three-way pipe, and the air outlet of the negative pressure three-way pipe is used to connect a cyclone separator.

[0017] By adopting the above technical solution, when in use, the lens protection airflow is sucked and recovered through the upper exhaust pipe, and the printing area protection airflow is sucked and recovered through the lower exhaust pipe, and then the recovered lens protection airflow and printing area protection airflow are re-converged into one stream through the negative pressure three-way pipe, and introduced into the cyclone separator for filtration. The filtered airflow is recovered for subsequent recycling.

[0018] Preferably, a plurality of diversion grille plates are arranged in an array in the upper exhaust duct and the lower exhaust duct, and the plurality of diversion grille plates are used to ensure uniform distribution of suction negative pressure in each area of ​​the upper exhaust duct and the lower exhaust duct, while guiding the airflow to enter the negative pressure three-way pipe stably.

[0019] By adopting the above technical solution, when in use, the flow channels in the upper exhaust duct and the lower exhaust duct are divided into several branch channels through several branch grid plates, thereby ensuring that the negative pressure in each area of ​​the flow channel is evenly distributed, thereby ensuring the stability of the airflow in the subsequent suction molding cavity.

[0020] Preferably, a decorative grille plate is provided at the air inlet of the upper exhaust duct.

[0021] By adopting the above technical solution, when in use, the setting of the decorative grille plate corresponds to the structural shape formed by the straight air outlet, which increases the aesthetics of the overall structure. On the other hand, it also forms the initial interception and filtration of the inhaled air flow.

[0022] Preferably, the air inlet of the lower exhaust duct is provided with a guide inclined plate, and the lowest end of the guide inclined plate is flush with the top surface of the forming platform.

[0023] By adopting the above technical solution, when in use, the height of the flow channel in the lower exhaust duct is raised by the guide inclined plate, which is conducive to guiding the airflow in on the one hand, and on the other hand, it can preliminarily intercept the heavier powder raw materials, reducing the situation where the powder raw materials are carried into the lower exhaust duct by the airflow, thereby reducing raw material consumption and saving printing raw material costs.

[0024] In summary, this application includes at least one of the following beneficial technical effects: 1. The air inlet tee unit, diverter grille assembly, airflow dispersion unit, tapered flow channel, and linear air outlet cooperate to perform multi-stage diversion, dispersion, redistribution, and diversion of the total airflow generated by the fan. This achieves uniform airflow distribution across all areas of the large-format build platform, effectively preventing the accumulation of smoke and splashing, and improving print quality. It also achieves high-speed flow in the build platform area with a small air volume, reducing the fan speed requirement, thereby effectively reducing fan energy consumption and filter element load. It also avoids fan elbow vibration and overheating caused by high air volume, improving equipment operational stability. 2. Through the cooperation of several groups of first vertical inclined plates and second vertical inclined plates and hollow holes, the linear inertial airflow formed by the upper air outlet duct, lower air outlet duct, first arc guide plate and second arc guide plate arranged in the arc structure is effectively dispersed, and at the same time, the vortex phenomenon formed in the flow channel is suppressed, ensuring that the airflow distribution passing through the corresponding area of ​​the airflow dispersion unit is more uniform.

[0025] 3. By improving the uniform distribution of airflow on the large-format building platform, the thermal field distribution inside the building chamber is optimized, ensuring uniform heat dissipation of printed parts and reducing thermal stress deformation and cracking; 4. The height of the flow channel in the lower exhaust pipe is raised by the guide inclined plate, which not only achieves airflow recovery but also reduces the powder waste caused by excessive regional airflow, thereby improving material utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is an axonometric diagram mainly showing the installation state of the overall structure in the embodiment of the present application; Figure 2 This is an axonometric diagram mainly showing the overall structure in the embodiment of the present application; Figure 3 This is a structural analysis diagram showing the appearance design of the air inlet tee pipe unit in an embodiment of the present application; Figure 4 This is a cross-sectional view mainly showing the internal structure of the air inlet three-way pipe unit in the embodiment of the present application; Figure 5 This is a schematic diagram mainly showing the sub-air outlet distribution structure in an embodiment of the present application; Figure 6This is an axonometric diagram mainly showing the distribution positions of the diverter grid components in the embodiment of the present application; Figure 7 This is an axonometric diagram mainly showing the structure of the airflow dispersion unit in the embodiment of the present application; Figure 8 yes Figure 6 The enlarged view of the structure of part A is mainly reflected in the figure; Figure 9 This is a cross-sectional view mainly showing the structure of the negative pressure ventilation unit in the embodiment of the present application; Figure 10 This is a schematic diagram mainly showing the distribution structure of the diversion grid plate in the embodiment of the present application; Figure 11 2 is a schematic diagram of the simulation results of airflow distribution corresponding to different distribution states of the diverter grille components in the embodiment of the present application; Figure 12 2 is a schematic diagram of the simulation results of the sub-air outlet flow rate corresponding to different distribution states of the diverter grille components in the embodiment of the present application; Figure 13 2 is a schematic diagram of the flow velocity simulation results of the corresponding area of ​​the air flow dispersion unit in the embodiment of the present application; Figure 14 Schematic diagram of flow velocity simulation results in the port area in the embodiment of the present application; Figure 15 Schematic diagram of flow velocity simulation results at a straight air outlet in an embodiment of the present application; Figure 16 It is a schematic diagram of the flow velocity simulation results within the entire area of ​​the printing platform in the embodiment of the present application.

[0027] Figure markings: 1. Air inlet three-way pipe unit; 11. Main air supply pipe; 12. Upper air outlet pipe; 13. Lower air outlet pipe; 14. Sub-air outlet; 2. Negative pressure exhaust unit; 21. Upper exhaust pipe; 22. Lower exhaust pipe; 23. Negative pressure three-way pipe; 24. Diverter grille plate; 25. Guide inclined plate; 3. Diverter grille assembly; 31. Horizontal grille plate; 32. Vertical grille plate; 33. First arc-shaped guide plate; 34. Second arc-shaped guide plate; 4. Guide pipe; 5. Air flow dispersion unit; 51. First vertical inclined plate; 52. Second vertical inclined plate; 53. Hollow hole; 54. Reinforcement rib; 6. Straight air outlet; 7. Conical flow channel; 8. Decorative grille plate. DETAILED DESCRIPTION

[0028] The following is combined with Figure 1 -Attached Figure 16 This application is described in further detail.

[0029] The embodiment of the present application discloses a wind field system with uniform airflow distribution for an additive manufacturing large-format forming platform.

[0030] Reference Figure 1 and Figure 2 The tee air inlet 11 is connected to the air inlet 12 of the main air supply pipe 11, the upper air outlet 12 and the lower air outlet 13, and the tee air inlet 11 is connected to the air inlet 12 of the main air supply pipe 11, the upper air outlet 12 and the lower air outlet 13.

[0031] Reference Figure 1 and Figure 2 When in use, the airflow generated by the fan is first compressed and accelerated through the conical main air supply pipe 11 to ensure the flow rate of the airflow into the upper air outlet pipe 12 and the lower air outlet pipe 13. When processing the air inlet tee pipe unit 1, the overall fluid dynamics design adopts the A-level surface standard. By controlling the curvature change of the curve on the surface, the smoothness of the zebra pattern of the formed surface is guaranteed to meet the standard. Figure 3 As shown, the distribution uniformity and smoothness of the zebra pattern on the arc-shaped curved structural surface of the upper air outlet duct 12 and the lower air outlet duct 13 must meet the Class A curved surface standard to reduce the flow resistance of the arc structure to the airflow; then, after being manufactured by 3D printing as an integrated whole, the inner wall surface of the tube is smooth-coated to minimize the airflow resistance and ensure the smooth flow of the airflow.

[0032] Reference Figure 2 and Figure 4 The size of the connection opening of the upper air outlet duct 12 and the main air supply duct 11 is smaller than the size of the connection opening of the lower air outlet duct 13 and the main air supply duct 11. In this embodiment, the cross-sectional area of ​​the air inlet of the upper air outlet duct 12 accounts for 15%-30% of the cross-sectional area of ​​the air outlet of the total air supply duct 11, and is preferably set to 30%. Through this design, it is ensured that the gas flow rate delivered to the upper air outlet duct 12 is less than the gas flow rate delivered to the lower air outlet duct 13, thereby ensuring that the subsequent air flow delivered to the forming platform area is moderate, that is, the total air flow input is minimized on the basis of ensuring that the smoke and splashes generated during the printing process are discharged.

[0033] Reference Figure 4 and Figure 5, a diverter grille assembly 3 is also provided in the upper air outlet duct 12 and the lower air outlet duct 13, and the diverter grille assembly 3 is used to distribute and guide the input airflow for the first time; the setting method, position and principle of the diverter grille assembly 3 in the upper air outlet duct 12 and the lower air outlet duct 13 are the same, and the air outlet duct 13 is taken as an example for description: the diverter grille assembly 3 includes a horizontal grille plate 31, a vertical grille plate 32 and a first arc-shaped guide plate 33, and the length of the horizontal grille plate 31, the vertical grille plate 32 and the first arc-shaped guide plate 33 all extend from the air inlet to the air outlet of the lower air outlet duct 13, wherein the vertical grille plate 32 separates the inner flow channel of the lower air outlet duct 13 along the vertical middle, so that the two sides of the vertical grille plate 32 are symmetrically arranged.

[0034] Reference Figure 4 and Figure 5 The horizontal grille plate 31 separates the inner flow channel of the lower air outlet duct 13 in the horizontal direction, ensuring that the area of ​​the air inlet and air outlet of the lower air outlet duct 13 is evenly divided into two parts, that is, at the air inlet and air outlet of the lower air outlet duct 13, the horizontal grille plate 31 and the vertical grille plate 32 are perpendicular to each other; in actual application, different numbers of horizontal grille plates 31 can be set according to the size of the air inlet and air outlet, so that the total airflow delivered is guided and diverted by a number of horizontal grille plates 31 to ensure that the airflow in the inner flow channel of the lower air outlet duct 13 is more evenly distributed in each area.

[0035] Reference Figure 5 and Figure 6 There are multiple first arc-shaped guide plates 33, and the multiple first arc-shaped guide plates 33 are divided into two groups and symmetrically distributed on both sides of the vertical grille plate 32, and a second arc-shaped guide plate 34 is also provided between two adjacent first arc-shaped guide plates 33. The lengths and curvatures of the multiple second arc-shaped guide plates 34 are different. In the present application, the lengths of the second arc-shaped guide plates 34 gradually increase along the vertical grille plate 32 to both sides, and the ends of the first arc-shaped guide plates 33 and the second arc-shaped guide plates 34 cooperate with the horizontal grille plate 31 and the vertical grille plate 32 to evenly divide the air outlet of the lower air outlet 13 into a plurality of sub-air outlets 14 arranged in a rectangular array, and the opening sizes of the plurality of sub-air outlets 14 are the same.

[0036] Reference Figure 4 and Figure 5When in use, the airflow input from the single circular air inlet is redistributed and guided to flow out from the rectangular air outlet through the cooperation of the horizontal grille plate 31, the vertical grille plate 32, the first arc-shaped guide plate 33 and the second arc-shaped guide plate 34 to cover the entire rectangular platform area. At the same time, due to the arc-shaped design of the air inlet three-way pipe unit 1, the airflow must turn during the flow process. Due to the inertia of the airflow, it is difficult to achieve uniform distribution by direct turning. Therefore, the first arc-shaped guide plate 33 and the second arc-shaped guide plate 34 are used to guide the flow path of the airflow, thereby improving the uniformity of the airflow and air volume flowing out of multiple sub-air outlets 14.

[0037] Reference Figure 4 and Figure 7 In order to further improve the uniformity of the airflow, an airflow dispersion unit 5 is provided inside the end of the air guide pipe 4 near the sub-air outlet 14. The airflow dispersion unit 5 is used to disperse and redistribute the airflow flowing out of the sub-air outlet 14, so as to improve the uniformity of the airflow distribution flowing through this area. The airflow dispersion unit 5 is composed of a plurality of groups of triangular hollow plates. The plurality of groups of triangular hollow plates are arranged in a square linear array along the length of the air inlet of the air guide pipe 4. In this embodiment, the number of triangular hollow plates is the same as the number of sub-air outlets 14 arranged in the length direction of the air outlet of the lower air outlet pipe 13 and the upper air outlet pipe 12, that is, each group of triangular hollow plates corresponds to a group of sub-air outlets 14, and a group of sub-air outlets 14 includes two sub-air outlets 14 separated by a horizontal grille plate 31.

[0038] Reference Figure 7 and Figure 8 , any group of triangular hollow plates includes a first vertical inclined plate 51 and a second vertical inclined plate 52, the first vertical inclined plate 51 is away from one end of the sub-air outlet 14 and the second vertical inclined plate 52 is away from one end of the sub-air outlet 14, and is fixedly connected together, the other ends of the first vertical inclined plate 51 and the second vertical inclined plate 52 are set to be open, and this open opening is aligned with a group of sub-air outlets 14, that is, there is an angle α between the first vertical inclined plate 51 and the second vertical inclined plate 52, and the angle range of this angle α is set to be between 15 degrees and 70 degrees. The specific value of α is adaptively adjusted according to the number of sub-air outlets 14 and the opening size. In this embodiment, α is preferably set to 30 degrees. The height of the first vertical inclined plate 51 and the second vertical inclined plate 52 is the same as the height of the inner channel of the guide pipe 4, and a plurality of hollow holes 53 are formed on the first vertical inclined plate 51 and the second vertical inclined plate 52. The hole shape of the hollow hole 53 can be square or honeycomb-shaped. In this embodiment, it is set to a square hole.

[0039] Reference Figure 4 and Figure 7When in use, the airflow flowing out of the sub-air outlet 14 is a linear inertial airflow. Under the action of the angle structure between the first vertical inclined plate 51 and the second vertical inclined plate 52, the direction of part of the linear inertial airflow is deflected by the reflection effect of the inclined surface. At the same time, the setting of the hollow hole 53 allows another part of the linear inertial airflow to pass directly. Under the synergistic effect of the two, the linear inertial airflow flowing through the area can be effectively dispersed and the eddy current phenomenon can be suppressed, thereby further improving the distribution uniformity of the subsequent flow process of the airflow; the inclination angle of the first vertical inclined plate 51 and the second vertical inclined plate 52, the density and opening size of the hollow hole 53 need to be optimized and adjusted according to simulation analysis or actual test results, and the triangular hollow plate formed after adjustment is made by 3D printing.

[0040] Reference Figure 4 and Figure 7 In addition, the opening size and density of the hollow holes 53 in a group of air flow dispersion units 5 can be the same or different. In the present application, the opening size of the hollow holes 53 on a first vertical inclined plate 51 and a second vertical inclined plate 52 located at the edges of the air inlet of the guide tube 4 in the length direction is larger, and the opening size of the hollow holes 53 in the middle area is smaller, and the distribution density of the hollow holes 53 in the edge area is less than the distribution density of the hollow holes 53 in the middle area, and except for a first vertical inclined plate 51 and a second vertical inclined plate 52 on both sides, the opening size and density of the hollow holes 53 on all the remaining first vertical inclined plates 51 and second vertical inclined plates 52 are the same; in actual use, since the airflow flowing through the guide tube 4 is relatively concentrated in the middle area, that is, the airflow in the edge areas on both sides is relatively small, through the density design of the above-mentioned hollow holes 53, the airflow in the middle area is more fully dispersed, and the airflow dispersion effect on the edges is weaker, thereby ensuring that the airflow in the middle area and the edge areas is gradually even after distribution.

[0041] Reference Figure 7 and Figure 8 In the present application, in two adjacent groups of triangular hollow plates, the first vertical inclined plate 51 of one group of triangular hollow plates is connected to the second vertical inclined plate 52 of the other group of triangular hollow plates, that is, multiple triangular hollow plates of a group of airflow dispersion units 5 are connected into a whole. At the same time, in order to further improve the structural strength of the airflow dispersion unit 5, reinforcing ribs 54 are connected between the adjacent first vertical inclined plates 51 and the second vertical inclined plates 52; when in use, the structural strength of the entire airflow dispersion unit 5 is increased by the setting of the reinforcing ribs 54, thereby reducing the deformation of the triangular hollow plates during the process of airflow impacting the triangular hollow plates.

[0042] Reference Figure 4A straight air outlet 6 is formed on the inner wall of the end of the air guide tube 4 away from the air flow dispersion unit 5. A plurality of straight air outlet holes 6 are provided and the plurality of straight air outlet holes 6 are distributed in a rectangular array. In the present application, the shape of the straight air outlet hole 6 is a slender rectangular hole. In other embodiments, the shape of the straight air outlet hole 6 can also be set to a circular or honeycomb type. A tapered flow channel 7 is provided between the air inlet of the straight air outlet hole 6 and the triangular hollow plate. The vertical cross-section of the tapered flow channel 7 is tapered and the end with the smaller opening size faces the straight air outlet hole 6. When in use, the application According to Bernoulli's principle, the airflow dispersed and redistributed by the airflow dispersion unit 5 is compressed and accelerated by the tapered flow channel 7, and the airflow is guided into the straight air outlet 6, so that the airflow is forced to maintain high-speed straight flow through the slender straight air outlet 6, so as to stably pass over the entire printing platform surface, and achieve the effect of high-speed flow in the printing platform area with a smaller air volume; the smaller air volume reduces the fan speed requirement, thereby effectively reducing the fan energy consumption and filter element load, while also reducing the problems of fan bend vibration and overheating, and improving the operating stability of the equipment.

[0043] Reference Figure 2 and Figure 9 The negative pressure exhaust unit 2 is used to extract the lens protection airflow and the printing area protection airflow under negative pressure and re-converge them to the cyclone separator for filtration and recovery. The negative pressure exhaust unit 2 consists of an upper exhaust pipe 21, a lower exhaust pipe 22 and a negative pressure three-way pipe 23, wherein the air inlets of the upper exhaust pipe 21 and the lower exhaust pipe 22 are both rectangular, and the air outlets are both circular, and the air inlet of the upper exhaust pipe 21 is corresponding to the air outlet of the upper outlet pipe 12, and the air inlet of the lower exhaust pipe 22 is corresponding to the air outlet of the lower outlet pipe 13, the air outlet of the upper exhaust pipe 21 and the air outlet of the lower exhaust pipe 22 are respectively connected to the two air inlets of the negative pressure three-way pipe 23, and the air outlet of the negative pressure three-way pipe 23 is connected to the cyclone separator through an external ventilation pipeline.

[0044] Reference Figure 2 and Figure 9 When in use, the airflow in the laser lens protection area is sucked through the upper exhaust pipe 21 and introduced into the negative pressure tee 23, and the airflow in the forming platform protection area is sucked through the lower exhaust pipe 22 and poured into the negative pressure tee 23. Then, the two airflows are merged into one through the negative pressure tee 23 and poured into the cyclone separator, so that the smoke and splashing objects carried in the airflow are intercepted and filtered by the cyclone separator, and the filtered airflow is guided to the external filtration system for secondary fine filtration. The filtration system can automatically perform backblowing cleaning and inerting treatment according to the data of the pressure difference sensor, so that the separated impurities are collected into the ash bucket, and the purified gas is finally transported to the fan assembly to achieve recycling.

[0045] Reference Figure 9 and Figure 10In order to ensure that the suction negative pressure in each area of ​​the flow channel in the upper exhaust duct 21 and the lower exhaust duct 22 remains evenly distributed, a plurality of diverter grille plates 24 are provided in the upper exhaust duct 21 and the lower exhaust duct 22. The plurality of diverter grille plates 24 are arranged in an array along the length direction of the air inlet end of the upper exhaust duct 21. In this embodiment, the diverter grille plates 24 are arranged in an L-shape, and the corners of the diverter grille plates 24 are arranged in an arc shape; when in use, the internal flow channels of the upper exhaust duct 21 and the lower exhaust duct 22 are separated by the plurality of diverter grille plates 24, thereby ensuring that the negative pressure in each area of ​​the flow channel is evenly distributed as much as possible, so as to realize the suction of the airflow in each area of ​​the molding cavity, and at the same time guide the inhaled airflow to stably enter the negative pressure three-way pipe 23, thereby ensuring the airflow discharge effect in the molding cavity.

[0046] Reference Figure 9 and Figure 10 21 , the vents 22 are vented to the top of the vents 22 so that the vents 22 do not get in the way of the vents 22. The vents 22 are vented to the top of the vents 22 so that the vents 22 do not get in the way of the vents 22.

[0047] Fluid analysis software was used for simulation, a finite element model was established, and a certain amount of wind speed and airflow was applied in the pipe. The airflow simulation trend is as follows: Figure 11 、 Figure 12 、 Figure 13 and Figure 14 As shown, the area closer to the blue display indicates that the airflow distribution in that part is smaller, and the area closer to the red display indicates that the airflow distribution in that part is more concentrated.

[0048] Reference Figure 11 and Figure 12 ,according to Figure 11 The comparison of the results of the three state diagrams a, b, and c shows that as the curvature and length of the second arc-shaped guide plate 34 change, the air flow distribution in the arc-shaped flow channel also changes until Figure 11 In the state of Figure c, the length of the second arc-shaped guide plate 34 is relatively small, the arc curvature is smoother, and the air flow distribution in the flow channel is more uniform. Similarly, Figure 12 The three states a, b, and c correspond to Figure 11 The flow rate of the sub-air outlet 14 in the three states a, b, and c can be seen from the above results. The length and curvature of the second arc-shaped guide plate 34 directly affect the uniformity of the guide airflow distribution. The structure disclosed in this embodiment is a structural design with relatively uniform airflow distribution.

[0049] Reference Figure 13 and Figure 14 In the figure, a1, b1, and c1 mainly reflect the airflow distribution state after the total airflow passes through the diverter grille assembly 3, the airflow dispersion unit 5, and the straight air outlet 6, and a2, b2, and c2 mainly reflect the airflow distribution state at the port under the a1, b1, and c1 states. By comparing the three states, it can be seen that when there is no airflow dispersion unit 5, the airflow flowing out of the port is obviously distributed in a concentrated area. After the airflow dispersion unit 5 is set, the airflow distribution is relatively uniform. With the increase of the gap and density of the opening size of the hollow holes 53 on the airflow dispersion unit 5, the airflow distribution gradually becomes uniform. Among them, c1 and c2 are the simulation results corresponding to the airflow dispersion unit 5 in this embodiment.

[0050] Reference Figure 15 In the three state diagrams a, b, and c in the figure, it can be clearly seen that in the state diagram c, because there is no airflow dispersion unit 5, the airflow outflowing from the linear air outlet 6 corresponding to each area is quite different. In the state b, the airflow dispersion unit 5 is added, and the airflow distribution in each area is significantly improved compared with the state a, but there is still a situation where the airflow is less in some areas; in the state a, the size and density of the hollow holes 53 of the airflow dispersion unit 5 are optimized, so the airflow distribution is more uniform than in the state b, and the airflow distribution in each area gradually tends to the preset target; refer to Figure 16 This embodiment adopts the structural design of the diverter grille component 3, the air flow dispersion unit 5, the tapered flow channel 7 and the straight air outlet 6, so that the air flow distribution in each area of ​​the wind field of the entire printing platform is uniform, which is more conducive to use.

[0051] The implementation principle of the embodiment of the present application is as follows: When in use, the flow of air is divided into the following stages: Phase 1: The total airflow generated by the fan passes through the main air supply pipe 11 and is divided into two paths. The airflow is respectively delivered to the upper air outlet pipe 12 and the lower air outlet pipe 13 to form an upward airflow and a downward airflow. The flow rate of the upward airflow is smaller than that of the downward airflow. Phase 2: Under the guidance and diversion of the diverter grille assembly 3, the upflow and downflow are relatively evenly distributed in various areas of the inner flow channels of the upper air outlet duct 12 and the lower air outlet duct 13, thereby redistributing the airflow from the single circular air inlet into multiple airflows, achieving a preliminary dispersion of the uniform flow of the airflow. In this process, due to the guidance of the arc-shaped structures of the upper air outlet duct 12 and the lower air outlet duct 13 and the first arc-shaped guide plate 33 and the second arc-shaped guide plate 34, the airflow must turn during the flow process. Under the action of the airflow inertia, the airflow in each flow channel converges to form a straight inertial airflow and flows out from the corresponding sub-air outlet 14. At the same time, the side with less airflow is prone to form a vortex phenomenon; Stage 3: When multiple straight inertial airflows pass through the airflow dispersion unit 5, a portion of the airflow impacts the first vertical inclined plate 51 and the second vertical inclined plate 52 and is deflected by the inclined surface reflection, thereby mixing with the airflow in other areas and flowing out from the corresponding hollow holes 53. The other portion of the airflow directly passes through the hollow holes 53. The synergistic effect of these two mechanisms effectively disperses the straight inertial airflow flowing through the area and simultaneously performs secondary distribution, further improving the uniformity of airflow distribution in each area within the flow, while also effectively suppressing the generation of vortex phenomena. Phase 4: Utilizing the Bernoulli principle, the airflow evenly dispersed by the airflow dispersion unit 5 is compressed and accelerated by the tapered flow channel 7 before being guided into the linear air outlet 6. Guided by the linear air outlet 6, it flows out, covering the entire rectangular platform area with a lower flow rate and higher flow velocity. The airflow from the linear air outlet 6 corresponding to the upper air outlet duct 12 is transported to the laser lens protection area, forming a lens protection airflow. The airflow from the linear air outlet 6 corresponding to the lower air outlet duct 13 is transported to the build platform protection area, forming a printing area protection airflow. Phase 5: The upper exhaust duct 21 and the lower exhaust duct 22 are arranged in a coordinated manner to collect the lens protection airflow and the printing area protection airflow. During the collection process, the multiple diversion grid plates 24 are arranged to ensure that the suction negative pressure in the flow channels of the upper exhaust duct 21 and the lower exhaust duct 22 is evenly distributed in all areas, thereby ensuring the effective capture of smoke and unmelted particles. Stage 6: The collected airflow is guided by the diverter grid plate 24, so that the rectangular cross-sectional airflow collected from the air inlets of the upper exhaust pipe 21 and the lower exhaust pipe 22 gradually converges into a circular cross-sectional airflow and is transported to the negative pressure three-way pipe 23. During this process, the diverter grid plate 24 optimizes the turning path of the airflow, suppresses the generation of vortices, reduces the flow resistance of the airflow, and maintains the air pressure stability of the subsequent converging process; Stage 7: The upper and lower air flows collected by the upper exhaust pipe 21 and the lower exhaust pipe 22 are re-converged into one air flow through the negative pressure T-tube 23 and stably transported to the cyclone separator for filtration and recovery. The air flow filtered by the cyclone separator is then subjected to secondary fine filtration through the filtration system. The separated impurities are uniformly collected in the ash bin, and the purified air flow is re-introduced into the fan for secondary recycling.

[0052] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A wind field system with uniform airflow distribution for a large-format additive manufacturing platform, characterized by: The invention comprises an air inlet three-way pipe unit (1) and a negative pressure exhaust unit (2), wherein the air inlet three-way pipe unit (1) comprises a main air supply pipe (11), an upper air outlet pipe (12) and a lower air outlet pipe (13), wherein the connection between the main air supply pipe (11) and the upper air outlet pipe (12) and the lower air outlet pipe (13) is arranged in an arc transition, and the size of the connection opening between the upper air outlet pipe (12) and the main air supply pipe (11) is smaller than the size of the connection opening between the lower air outlet pipe (13) and the main air supply pipe (11), and a diverter grille assembly (3) is arranged in each of the upper air outlet pipe (12) and the lower air outlet pipe (13), wherein the diverter grille assembly (3) connects the upper air outlet pipe (12) and the lower air outlet pipe (13) to form a circular arc transition. ) and the air outlet of the lower air outlet duct (13) are divided into a plurality of sub-air outlets (14) with the same opening size, and the air outlets of the upper air outlet duct (12) and the lower air outlet duct (13) are both provided with a guide pipe (4), and an air flow dispersion unit (5) is provided on one side of the guide pipe (4) close to the sub-air outlet (14), and a plurality of linear air outlet holes (6) distributed in an array are formed on the other side of the guide pipe (4), and the air flow channel between the air flow dispersion unit (5) and the linear air outlet holes (6) is provided as a conical flow channel (7) with a conical cross section, and the end of the conical flow channel (7) with a smaller opening is provided toward the linear air outlet holes (6); The air flow dispersion unit (5) is used to disperse the inertial air flow flowing out of the sub-air outlet (14) and redistribute it so that it is evenly distributed in the conical flow channel (7); the conical flow channel (7) is used to compress and accelerate the dispersed air flow and then introduce it into the linear air outlet (6), and transport it to the laser lens protection area and the molding platform protection area through the linear air outlet (6) respectively, forming a lens protection air flow and a printing area protection air flow; the negative pressure exhaust unit (2) is used to negatively extract the lens protection air flow and the printing area protection air flow and re-converge them to guide the cyclone separator for filtration and recovery.

2. The wind field system with uniform airflow distribution for a large-format additive manufacturing forming platform according to claim 1, characterized in that: The diverter grille assembly (3) comprises a transverse grille plate (31), a vertical grille plate (32) and a first arc-shaped guide plate (33). A plurality of the first arc-shaped guide plates (33) are provided. The plurality of the first arc-shaped guide plates (33) are distributed at intervals on both sides of the vertical grille plate (32). A second arc-shaped guide plate (34) is provided between two adjacent first arc-shaped guide plates (33). The lengths and curvatures of the plurality of the second arc-shaped guide plates (34) are different.

3. The wind field system with uniform airflow distribution for a large-format additive manufacturing forming platform according to claim 1, characterized in that: The air flow dispersion unit (5) comprises a plurality of groups of triangular hollow plates arranged in a linear array, and two adjacent groups of triangular hollow plates are fixedly connected. The triangular hollow plates comprise a first vertical inclined plate (51) and a second vertical inclined plate (52), and the first vertical inclined plate (51) is fixedly connected to the end away from the sub-air outlet (14) and the second vertical inclined plate (52) is fixedly connected to the end away from the sub-air outlet (14). There is an angle between the first vertical inclined plate (51) and the second vertical inclined plate (52), and hollow holes (53) are provided on the first vertical inclined plate (51) and the second vertical inclined plate (52). Part of the straight inertial airflow flowing out of the sub-air outlet (14) is deflected by the inclined surfaces of the first vertical inclined plate (51) and the second vertical inclined plate (52), and the other part of the airflow directly passes through the hollow holes (53).

4. The wind field system with uniform airflow distribution for a large-format additive manufacturing forming platform according to claim 3, characterized in that: A reinforcing rib (54) is connected between the first vertical inclined plate (51) and the adjacent second vertical inclined plate (52).

5. The wind field system with uniform airflow distribution for a large-format additive manufacturing forming platform according to claim 3, characterized in that: The size of the hollow holes (53) located at both ends of the airflow dispersion unit (5) is larger than the size of the hollow hole (53) located in the middle of the airflow dispersion unit (5).

6. The wind field system with uniform airflow distribution for a large-format additive manufacturing forming platform according to claim 1, characterized in that: The negative pressure exhaust unit (2) comprises an upper exhaust pipe (21), a lower exhaust pipe (22) and a negative pressure three-way pipe (23); the air inlet of the upper exhaust pipe (21) is arranged correspondingly to the air outlet of the upper air outlet pipe (12); the air inlet of the lower exhaust pipe (22) is arranged correspondingly to the air outlet of the lower air outlet pipe (13); the air outlet of the upper exhaust pipe (21) and the air outlet of the lower exhaust pipe (22) are respectively connected to the two air inlets of the negative pressure three-way pipe (23); and the air outlet of the negative pressure three-way pipe (23) is used to connect to a cyclone separator.

7. The wind field system with uniform airflow distribution for a large-format additive manufacturing forming platform according to claim 6, characterized in that: A plurality of diversion grid plates (24) are arranged in an array in the upper exhaust duct (21) and the lower exhaust duct (22). The plurality of diversion grid plates (24) are used to ensure that the negative pressure of air suction in each area of ​​the upper exhaust duct (21) and the lower exhaust duct (22) is evenly distributed, and at the same time, guide the air flow to stably enter the negative pressure three-way pipe (23).

8. The wind field system with uniform airflow distribution for a large-format additive manufacturing forming platform according to claim 6, characterized in that: A decorative grille plate (8) is provided at the air inlet of the upper exhaust pipe (21).

9. The wind field system with uniform airflow distribution for a large-format additive manufacturing forming platform according to claim 6, characterized in that: The air inlet of the lower exhaust pipe (22) is provided with a guide inclined plate (25), and the lowest end of the guide inclined plate (25) is flush with the top surface of the forming platform.

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