Selective laser melting metal 3d printer wind field device

Abstract

The utility model discloses a kind of selective laser melting metal 3D printer wind field device, belong to additive manufacturing equipment technical field, the device includes annular air curtain module, wind wall module, negative pressure dust extraction module and collaborative control module;The annular air curtain module is located at metal 3D printing forming cylinder top;The wind wall module is located at metal 3D printing forming cylinder left part;The negative pressure dust extraction module is located at metal 3D printing forming cylinder bottom;The collaborative control module controls annular air curtain module gas flow and the wind pressure of wind wall module;Wherein, the wind wall module includes upper wind wall and lower wind wall.The device has multistage collaborative type laminar flow-turbulent flow composite wind field structure, through zoned flow guiding and pressure collaborative control, smoke dust residual quantity reduces by more than 40%, and part density can be promoted to more than 99.8%.

Description

Technical Field

[0001] This utility model belongs to the field of additive manufacturing equipment technology, specifically relating to a wind field device for a selective laser melting metal 3D printer. Background Technology

[0002] In the selective laser melting (SLM) metal 3D printing process, the high-energy laser melting of metal powder generates a large amount of metal vapor and splatter particles. Existing technologies generally use a unidirectional laminar flow inert gas purging method to remove the fumes, which has the following drawbacks: unidirectional airflow easily forms a low-pressure vortex zone behind the printing area, causing fumes to remain and adhere to unmelted powder or the surface of the formed part, affecting the quality of interlayer bonding; unidirectional airflow makes it difficult to maintain the uniformity of oxygen content throughout the forming cylinder, and the edge areas are easily disturbed by air infiltration, leading to metal oxidation; high-speed airflow may blow away the flattened metal powder layer, which has a significant impact on lightweight alloys. Utility Model Content

[0003] To address the problems existing in the prior art, this utility model proposes a wind field device for a selective laser melting metal 3D printer. The device has a multi-level collaborative laminar-turbulent composite wind field structure, which achieves efficient smoke and dust removal and optimized atmosphere stability through zoned flow guidance and pressure coordinated control.

[0004] The technical solution of this utility model is as follows: This invention provides a selective laser melting metal 3D printing air field device, including an annular air curtain module, an air wall module, a negative pressure dust extraction module, and a collaborative control module; the annular air curtain module is located at the top of the metal 3D printing forming cylinder; the air wall module is located at the left side of the metal 3D printing forming cylinder; the negative pressure dust extraction module is located at the bottom of the metal 3D printing forming cylinder; the collaborative control module is used to control the gas flow rate of the annular air curtain module and the air pressure of the air wall module; wherein, the air wall module includes an upper air wall and a lower air wall.

[0005] Furthermore, the air outlet of the annular air curtain module is tilted downwards, and inert gas is inclined to be sent into the center of the metal 3D printing molding cylinder to form a centripetal downward annular air curtain.

[0006] Furthermore, the air outlet tilt angle of the annular air curtain module is 15°~30°.

[0007] Furthermore, the upper and lower wind walls have a honeycomb-shaped flow guiding structure with micropores evenly distributed on their surfaces. The airflow in the lower wind wall generates low-pressure turbulence below the laser's point of action, while the airflow in the upper wind wall assists in blowing the smoke and dust to the right.

[0008] Furthermore, the diameter of the micropores on the surface of the honeycomb flow guiding structure is 0.5~2mm.

[0009] Furthermore, the negative pressure dust extraction module includes a negative pressure chamber with a flow guide plate, a filter, and a vacuum fan; The flow guide plate has a downward-sloping angle; The negative pressure chamber is connected to a vacuum fan via a multi-stage filter.

[0010] Furthermore, the angle of the guide vane ranges from 15° to 30°.

[0011] Furthermore, the collaborative control module monitors the oxygen concentration inside the metal 3D printing molding cylinder and the real-time airflow of the air wall module, and adjusts the gas flow rate of the annular air curtain module and the air pressure of the air wall module.

[0012] This utility model discloses an airflow device for a selective laser melting metal 3D printer, which has the following beneficial effects: improved dust removal rate, enhanced dust diffusion through the air wall module, and directional airflow through the negative pressure dust extraction module, resulting in a reduction of dust residue by more than 40%; optimized atmosphere uniformity, with the annular air curtain module suppressing edge air penetration, ensuring that the oxygen concentration in the forming cavity remains below 50 ppm throughout the printing process; guaranteed printing quality, preventing metal powder from being blown away, ensuring uniform powder distribution, reducing dust adhesion to the surface of the formed structure, and increasing part density to over 99.8%; and intelligent control, with closed-loop control based on real-time sensor data, adapting to maintain stable airflow output in various scenarios. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the airflow device for a selective laser melting metal 3D printer according to the present invention. Figure 2 This is a schematic diagram of the cross-section of the annular air curtain module's slit-type air outlet. Figure 3 This is a schematic diagram of a honeycomb-shaped flow guiding structure; Figure 4 This is a schematic diagram of the oblique-angle flow guide plate structure; The reference numerals in the figure indicate: 1. Annular air curtain module; 1a. Annular air curtain module with slit-type air outlet; 2. Air wall module; 2a. Honeycomb-shaped airflow guiding structure of upper and lower air walls; 3. Air pressure regulating valve; 4. Laser action point plane; 5. Negative pressure dust extraction module; 5a. Angled airflow guide plate; Figure 5 This is a schematic diagram simulating the airflow path of an airflow field device for a selective laser melting metal 3D printer. Detailed Implementation

[0014] The technical solutions in the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the protection scope of this utility model.

[0015] In the description of this specification, it should be understood that the terms "top", "bottom", "circumferential", "center", "left side", "upper", "lower", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the technical solution of this patent and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this patent application.

[0016] Example 1: This embodiment provides an airflow device for a selective laser melting metal 3D printer, including an annular air curtain module, an air wall module, a negative pressure dust extraction module, and a collaborative control module.

[0017] like Figure 1 As shown, a ring-shaped air curtain module is installed on the top of the metal 3D printing molding cylinder, a wind wall module is connected to the left side, and a negative pressure dust extraction module is connected to the bottom. The collaborative control module controls the gas flow rate of the ring-shaped air curtain module and the air pressure of the wind wall module; the wind wall module includes an upper wind wall and a lower wind wall.

[0018] The annular air supply chamber of the annular air curtain module has a width of 20mm. The annular air supply chamber is circumferentially embedded in the top of the metal 3D printing molding cylinder, such as... Figure 2 As shown, an annular air supply chamber has a slit-type air outlet at its bottom, with a slit width of 0.8 mm and an inclination angle of 20°. Inert gas is introduced at an angle from the gas inlet towards the center of the metal 3D printing cylinder, with a total air flow rate of 5~20 L / min. This forms a centripetal downward-sinking annular air curtain, preventing external air from seeping in, reducing the oxygen concentration at the edge of the metal 3D printing area, and preventing dust from rising and contaminating the laser printing lens located in the center of the annular air curtain module. The 20° inclination angle causes the inert gas to flow towards the side wall of the cylinder at a higher velocity component and flow downward along the side wall, forming a dynamic "gas curtain" that is tightly attached to the cylinder wall. This greatly reduces the risk of blowing away the already smoothed metal powder bed, especially light and fine powder. If the angle is greater than 30°, the vertical component of the airflow is too large and will directly impact the edge of the metal powder bed, causing the powder bed to become uneven or even scraped, resulting in printing failure.

[0019] The airflow wall module is located on the left side of the metal 3D printing cylinder. A porous airflow wall, including an upper and lower airflow wall, is integrated coaxially with the printing laser head, and its interior features a honeycomb-like airflow guiding structure (e.g., ...). Figure 3 As shown), the porous wind wall has a diameter of 30mm and uniformly distributed micropores with a diameter of 1mm on its surface, with a pore density of 20 pores / cm². 2 The upper and lower wind walls are connected to fans via quick-release interfaces for independent air supply, and the wind pressure of the upper and lower wind walls can be adjusted independently. The wind speed of the lower wind wall is 1~2.5m / s, and the higher wind speed generates low-pressure turbulence below the laser action point, which enhances the efficiency of smoke and dust extraction. The wind speed of the upper wind wall is 0.5~1.6m / s, which helps to blow the smoke and dust to the right and prevent smoke and dust from contaminating the printing area.

[0020] A negative pressure chamber with an angled flow guide plate is set at the bottom of the metal 3D printing molding cylinder, such as... Figure 4 As shown, the angle of the guide plate is 20°, and the negative pressure chamber is connected to a vacuum fan via a multi-stage filter, with a vacuum pumping speed ≥50m / s. 3 / h, the pressure inside the cavity can be dynamically adjusted.

[0021] The annular air curtain module is equipped with a flow sensor to adjust the gas flow in real time. When the oxygen sensor detects that the oxygen concentration in a certain area of ​​the metal 3D printing molding cylinder is >500ppm, the collaborative control module controls the gas flow in that area to increase by 20%. The wind speed sensor of the wind wall module is installed in the positive pressure pipeline to monitor the air volume in real time and ensure the stability of the air volume. When the wind speed sensor detects that the wind speed is weakening, it controls the wind pressure regulating valve to automatically compensate the wind speed to the threshold. Figure 5 The gray arrows indicate the inert gas flow direction of the annular air curtain module, while the black arrows indicate the airflow direction of the wind wall module.

[0022] Example 2 This embodiment provides an airflow device for a selective laser melting metal 3D printer, including a metal 3D printing forming cylinder, an annular air curtain module, an air wall module, a negative pressure dust extraction module, and a collaborative control module.

[0023] A ring-shaped air curtain module is installed on the top of the metal 3D printing molding cylinder, a wind wall module is connected to the left side, and a negative pressure dust extraction module is connected to the bottom. A collaborative control module controls the gas flow of the ring-shaped air curtain module and the air pressure of the wind wall module; the wind wall module includes an upper wind wall and a lower wind wall.

[0024] The annular air curtain module has an annular air supply chamber with a width of 20mm. The annular air supply chamber is embedded circumferentially in the top of the metal 3D printing molding cylinder. An annular slit-type air outlet is opened at the bottom of the annular air supply chamber. The air outlet slit is 0.8mm wide and tilted at an angle of 15°. Inert gas is introduced into the center of the metal 3D printing molding cylinder from the gas inlet. The total air supply flow rate is 5~20L / min, forming a centripetal downward annular air curtain, which isolates the infiltration of external air, reduces the oxygen concentration at the edge of the metal 3D printing area, and at the same time prevents smoke and dust from contaminating the laser printing lens located in the center of the annular air curtain module.

[0025] The airflow module is located on the left side of the metal 3D printing cylinder. A porous airflow module, including an upper airflow module and a lower airflow module, is integrated coaxially with the printing laser head. The internal structure is a honeycomb-shaped airflow guide. The porous airflow module has a diameter of 30mm and a surface with evenly distributed micropores of 2mm diameter. The upper and lower airflow modules are connected to fans for independent air supply via quick-release interfaces. The air pressure of the upper and lower airflow modules can be adjusted independently. The lower airflow module has a wind speed of 1~2.5m / s. The higher wind speed generates low-pressure turbulence below the laser point of action, enhancing the efficiency of smoke and dust extraction. The upper airflow module has a wind speed of 0.5~1.6m / s, which helps to blow smoke and dust to the right and prevent smoke and dust from contaminating the printing area.

[0026] A negative pressure chamber with an angled guide plate is set at the bottom of the metal 3D printing molding cylinder. The angle of the guide plate is 15°. The negative pressure chamber is connected to a vacuum fan through a multi-stage filter, and the vacuum pumping speed is ≥50m / s. 3 / h, the pressure inside the cavity can be dynamically adjusted.

[0027] The annular air curtain module is equipped with a flow sensor to adjust the gas flow in real time. When the oxygen sensor detects that the oxygen concentration in a certain area of ​​the metal 3D printing molding cylinder is >500ppm, the collaborative control module controls the gas flow in that area to increase by 20%. The wind speed sensor of the wind wall module is installed in the positive pressure pipeline to monitor the air volume in real time and ensure the stability of the air volume. When the wind speed sensor detects that the wind speed is weakening, it controls the wind pressure regulating valve to automatically compensate the wind speed to the threshold.

[0028] Example 3 This embodiment provides an airflow device for a selective laser melting metal 3D printer, including a metal 3D printing forming cylinder, an annular air curtain module, an air wall module, a negative pressure dust extraction module, and a collaborative control module.

[0029] A ring-shaped air curtain module is installed on the top of the metal 3D printing molding cylinder, a wind wall module is connected to the left side, and a negative pressure dust extraction module is connected to the bottom. A collaborative control module controls the gas flow of the ring-shaped air curtain module and the air pressure of the wind wall module; the wind wall module includes an upper wind wall and a lower wind wall.

[0030] The annular air supply chamber of the annular air curtain module has a width of 20mm. The annular air supply chamber is embedded circumferentially in the top of the metal 3D printing molding cylinder. An annular slit-type air outlet is opened at the bottom of the annular air supply chamber. The air outlet slit is 0.8mm wide and tilted at an angle of 30°. Inert gas is introduced into the center of the metal 3D printing molding cylinder from the gas inlet. The total air supply flow rate is 5~20L / min, forming a centripetal downward annular air curtain, which isolates the infiltration of external air, reduces the oxygen concentration at the edge of the metal 3D printing area, and at the same time prevents smoke and dust from contaminating the laser printing lens located in the center of the annular air curtain module.

[0031] The airflow module is located on the left side of the metal 3D printing cylinder. A porous airflow module, including an upper airflow module and a lower airflow module, is integrated coaxially with the printing laser head. The internal structure is a honeycomb-shaped airflow guide. The porous airflow module has a diameter of 30mm and a surface with micropores of 0.5mm in diameter. The upper and lower airflow modules are connected to fans for independent air supply via quick-release interfaces. The air pressure of the upper and lower airflow modules can be adjusted independently. The lower airflow module has a wind speed of 1~2.5m / s. The higher wind speed generates low-pressure turbulence below the laser point of action, which enhances the efficiency of smoke and dust extraction. The upper airflow module has a wind speed of 0.5~1.6m / s, which helps to blow the smoke and dust to the right and prevent smoke and dust from contaminating the printing area.

[0032] A negative pressure chamber with an angled guide plate is set at the bottom of the metal 3D printing molding cylinder. The angle of the guide plate is 30°. The negative pressure chamber is connected to a vacuum fan through a multi-stage filter, and the vacuum pumping speed is ≥50m / s. 3 / h, the pressure inside the cavity can be dynamically adjusted.

[0033] The annular air curtain module is equipped with a flow sensor to adjust the gas flow in real time. When the oxygen sensor detects that the oxygen concentration in a certain area of ​​the metal 3D printing molding cylinder is >500ppm, the collaborative control module controls the gas flow in that area to increase by 20%. The wind speed sensor of the wind wall module is installed in the positive pressure pipeline to monitor the air volume in real time and ensure the stability of the air volume. When the wind speed sensor detects that the wind speed is weakening, it controls the wind pressure regulating valve to automatically compensate the wind speed to the threshold.

[0034] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the description and drawings of this utility model, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

[0035] Example 4 This embodiment provides an airflow device for a selective laser melting metal 3D printer, which differs from Embodiment 1 in that: The collaborative control module uses a high-precision oxygen sensor to detect the oxygen content in the metal 3D printing molding cylinder in real time. A pressure sensor is installed in the metal 3D printing molding cylinder to monitor the gas pressure distribution and gradient, ensuring a stable atmosphere in the metal 3D printing molding cylinder. A flow sensor is installed on the inert gas supply line of the annular air curtain module to accurately measure the flow rate of inert gas leading to the annular gas supply chamber. An airflow sensor is installed on the duct leading to the air wall module to accurately monitor the airflow speed; These sensors transmit the detected data back to the main control unit, such as an embedded industrial computer, and then feed it back to the actuators, such as proportional valves and mass flow controllers.

Claims

1. A wind field device for a selective laser melting metal 3D printer, characterized in that, It includes a ring-shaped air curtain module, an air wall module, a negative pressure dust extraction module, and a collaborative control module; The annular air curtain module is located at the top of the metal 3D printing molding cylinder; The wind wall module is located on the left side of the metal 3D printing molding cylinder; The negative pressure dust extraction module is located at the bottom of the metal 3D printing molding cylinder; The collaborative control module is used to control the gas flow rate of the annular air curtain module and the air pressure of the wind wall module. The wind wall module includes an upper wind wall and a lower wind wall.

2. The selective laser melting metal 3D printer airflow device according to claim 1, characterized in that, The air outlet of the annular air curtain module is tilted downwards, and inert gas is inclined to be sent into the center of the metal 3D printing molding cylinder to form a centripetal downward annular air curtain.

3. The selective laser melting metal 3D printer airflow device according to claim 2, characterized in that, The outlet tilt angle of the annular air curtain module is 15°~30°.

4. The selective laser melting metal 3D printer airflow device according to claim 1, characterized in that, The upper and lower wind walls have a honeycomb-shaped flow guiding structure inside, with micropores evenly distributed on the surface. The airflow in the lower wind wall generates low-pressure turbulence below the laser's point of action, while the airflow in the upper wind wall helps to blow the smoke and dust to the right.

5. The selective laser melting metal 3D printer airflow device according to claim 4, characterized in that, The diameter of the micropores on the surface of the honeycomb flow guiding structure is 0.5~2mm.

6. The selective laser melting metal 3D printer airflow device according to claim 1, characterized in that, The negative pressure dust extraction module includes a negative pressure chamber with a flow guide plate, a filter, and a vacuum fan; The flow guide plate has a downward-sloping angle; The negative pressure chamber is connected to a vacuum fan via a multi-stage filter.

7. The selective laser melting metal 3D printer airflow device according to claim 6, characterized in that, The angle of the guide vane ranges from 15° to 30°.

8. The selective laser melting metal 3D printer airflow device according to claim 1, characterized in that, The collaborative control module monitors the oxygen concentration inside the metal 3D printing molding cylinder and the real-time airflow of the air wall module, and adjusts the gas flow rate of the annular air curtain module and the air pressure of the air wall module.

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