Wind field control mechanism for metal 3D and powder blowing restraining method

Abstract

The invention relates to the technical field of metal 3D printing, and discloses a wind field control mechanism for metal 3D and a powder blowing restraining method, aiming at solving the technical problems of how to restrain a powder blowing phenomenon caused by scraper interference to reduce powder waste and ensure stable printing quality while keeping a high wind speed to ensure the forming quality. Comprising a forming cavity, an upper air inlet and a lower air inlet are formed in the upper portion and the lower portion of a first side face respectively, an exhaust port is formed in the lower portion of a second side face, the upper end and the lower end of the flow divider communicate with the upper air inlet and the lower air inlet respectively, and an air inlet pipeline is connected to the middle of the flow divider; the wind shield is located outside the lower air inlet and installed on the rotating shaft, a rotating air cylinder for driving the rotating shaft to rotate is arranged outside the flow divider, and the rotating air cylinder is installed on the flow divider. And the powder blowing phenomenon caused by scraper interference in the powder laying process is inhibited, so that powder waste is reduced, and stable printing quality is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of metal 3D printing, and in particular to a wind field control mechanism for metal 3D and a method for suppressing powder blowing. Background Art

[0002] In the SLM (Selective Laser Melting) metal 3D printing process, a higher wind speed above the powder bed helps improve the molding quality. However, too high a wind speed will blow the powder away, resulting in uneven thickness of the powder layer, thus affecting the printing quality. Therefore, a wind speed close to the critical wind speed for blowing powder is usually selected during the molding process to balance the molding quality and powder stability.

[0003] However, during the powder spreading process, the scraper will disturb the original wind field when passing through the air outlet, causing the local wind speed to increase significantly, especially the wind speed in the areas on both sides of the scraper. This will cause serious powder blowing, and the powder will be blown into the circulation filtration system, causing a lot of waste.

[0004] These two phenomena have caused a pair of contradictions: on the one hand, if a higher wind speed is selected, the molding quality can be guaranteed, but it will cause powder blowing and powder waste during the powder spreading process; on the other hand, if the wind speed is reduced, the powder blowing phenomenon during the powder spreading process can be reduced, but the molding quality will be reduced. Summary of the invention

[0005] The purpose of the present invention is to provide a wind field control mechanism for metal 3D and a method for suppressing powder blowing, so as to solve the technical problem of how to suppress the powder blowing phenomenon caused by scraper interference during the powder spreading process while maintaining high wind speed to ensure molding quality, thereby reducing powder waste and ensuring stable printing quality.

[0006] To achieve the above-mentioned objectives, the present invention provides a wind field control mechanism for metal 3D printing, comprising a molding cavity, having a first side surface and a second side surface arranged opposite to each other, the upper and lower portions of the first side surface are respectively provided with an upper air inlet and a lower air inlet, the lower portion of the second side surface is provided with an exhaust port, and also comprises a diverter connected to the molding cavity, the upper and lower ends of the diverter are respectively connected to the upper air inlet and the lower air inlet, the middle portion of the diverter is connected to an air intake duct, a wind shield is provided in the diverter, the wind shield is located outside the lower air inlet, the wind shield is installed on a rotating shaft, a rotating cylinder for driving the rotating shaft to rotate is provided outside the diverter, and the rotating cylinder is installed on the diverter.

[0007] Through the rationally designed wind field control mechanism, a high wind speed can be maintained during the molding process, which is conducive to improving the molding quality of metal 3D printing. The airflow is evenly distributed in the molding cavity, effectively reducing the risk of uneven cooling and powder particle displacement, ensuring the accuracy and strength of the printed parts.

[0008] Furthermore, the diverter is fixedly connected to the molding cavity.

[0009] Furthermore, the upper air inlet and the lower air inlet are rectangular openings, and the diverter is U-shaped.

[0010] The diverter is fixedly connected to the molding cavity, and the upper and lower air inlets are rectangular openings. The U-shaped design of the diverter can effectively distribute the airflow evenly to various areas of the molding cavity, improve the distribution of the airflow and the molding quality, and reduce the local airflow unevenness. At the same time, the rectangular opening design improves the stability of the airflow and reduces the disturbance when entering the molding cavity, thereby avoiding the problem of unstable airflow. The U-shaped diverter effectively reduces the impact and eddy current of the airflow, ensures that the airflow enters the molding cavity smoothly, and improves the molding accuracy and surface quality. In addition, by optimizing the airflow distribution and flow path, the airflow resistance loss is reduced, the molding efficiency is improved, and the energy consumption is reduced. At the same time, the fixed connection design improves the sealing between the diverter and the molding cavity, avoids gas leakage or unnecessary interference, improves the control accuracy of the molding process, simplifies the maintenance and adjustment process, and ensures the stability of the fit.

[0011] The present invention also provides a method for suppressing powder blowing for metal 3D printing, wherein a first side surface and a second side surface are arranged opposite to each other in a molding cavity, an upper air inlet and a lower air inlet are arranged at the upper and lower parts of the first side surface respectively, and an exhaust port is arranged at the lower part of the second side surface, including the following strategies:

[0012] The airflow is introduced into the splitter through the air inlet duct, and the airflow is divided into two paths in the splitter, entering the molding cavity through the upper air inlet and the lower air inlet respectively, and the airflow is finally discharged through the exhaust port;

[0013] During the printing process, the wind shield is controlled to be in a horizontal state so that the airflow evenly enters the molding cavity through the upper air inlet and the lower air inlet to ensure the airflow distribution during the printing process;

[0014] During the powder spreading process, the windshield is rotated to a vertical position by a rotating cylinder to reduce the air flow velocity through the lower air inlet, thereby reducing the local wind speed on the powder bed surface and avoiding the powder blowing phenomenon caused by the interference of the scraper, thereby reducing powder waste;

[0015] After the powder is spread, the wind shield is controlled to rotate to a horizontal state again to restore the wind speed conditions required during the printing process.

[0016] During the powder spreading process, the design and control of the windshield reduces the wind speed when the scraper passes by, avoiding the powder being blown away due to excessive wind speed. By rotating the windshield to a vertical state and controlling the airflow at the lower air inlet, the powder waste caused by blowing powder is significantly reduced, thereby reducing material costs.

[0017] The diverter structure design in the present invention enables the airflow to enter the molding cavity evenly through the upper and lower air inlets, and the direction and speed of the airflow can be flexibly controlled by adjusting the rotating cylinder and the wind shield. This flexible airflow control mechanism ensures that the optimal airflow distribution conditions can be achieved in different printing stages, improving the stability of the printing process.

[0018] By suppressing the powder blowing phenomenon during the powder laying process, the powder loss and cleaning time are reduced, thereby improving the production efficiency of metal 3D printing.

[0019] The wind field control mechanism and powder blowing suppression method for metal 3D provided by the present invention have the following advantages:

[0020] The present invention solves the contradiction between the need for high wind speed to improve printing quality during the molding process and the powder blowing phenomenon during the powder spreading process by designing a wind field control mechanism for metal 3D printing. The proposed wind field control mechanism can effectively suppress the powder waste in the powder spreading process while ensuring the printing quality. Specifically, in the printing and molding stage, the wind shield is in a horizontal state to ensure that the airflow is evenly distributed in the molding cavity, thereby improving the precision and strength of the molded part; in the powder spreading process, the rotating cylinder controls the wind shield to rotate to a vertical state, reducing the air flow speed at the lower air inlet, thereby reducing the local wind speed on the powder bed surface, avoiding the powder blowing phenomenon caused by scraper interference, reducing the waste of powder blown into the circulation filtration system, and ensuring the uniformity of the powder layer. This improves production efficiency and extends the service life of the equipment, making the entire metal 3D printing process more economical and efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A three-dimensional diagram of the wind farm control mechanism provided by the present invention;

[0022] Figure 2 A longitudinal cross-sectional view of a wind farm control mechanism provided by the present invention;

[0023] Figure 3 A diagram of the molding cavity and windshield mechanism provided by the present invention;

[0024] Figure 4 A schematic diagram of the wind field in the molding cavity at a uniform wind speed provided by the present invention;

[0025] Figure 5 A schematic diagram of the wind field changes in the molding cavity when the scraper provides the present invention to spread the powder;

[0026] Figure 6 A schematic diagram of the wind field in the molding cavity when the wind shield provided by the present invention is opened;

[0027] Figure 7 A schematic diagram of the wind field in the molding cavity when the wind shield provided by the present invention is closed.

[0028] In the figure: 1. molding cavity; 2. air inlet duct; 3. diverter; 4. rotating cylinder; 5. upper air inlet; 6. wind shield; 61. rotating shaft; 7. lower air inlet; 8. powder bed surface; 9. exhaust port. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0030] See also Figures 1 to 3 The present invention provides a wind field control mechanism for metal 3D printing, including a molding cavity 1, an upper air inlet 5 and a lower air inlet 7 are respectively arranged at the upper and lower parts of the rear side of the molding cavity 1, an exhaust port 9 is arranged at the lower part of the front side of the molding cavity 1, and metal powder is laid on the inner bottom of the molding cavity 1 to form a powder bed surface 8.

[0031] A diverter 3 connected to the molding cavity 1 is provided, and the upper and lower ends of the diverter 3 are respectively connected to the upper air inlet 5 and the lower air inlet 7. The middle part of the diverter 3 is connected to the air inlet duct 2. A wind shield 6 is provided in the diverter 3. The wind shield 6 is located outside the lower air inlet 7. The wind shield 6 is installed on a rotating shaft 61. A rotating cylinder 4 for driving the rotating shaft 61 is provided outside the diverter 3, and the rotating cylinder 4 is installed on the diverter 3.

[0032] Preferably, the diverter 3 is fixedly connected to the molding cavity 1; the upper air inlet 5 and the lower air inlet 7 are rectangular openings; and the diverter 3 is U-shaped.

[0033] See also Figures 4 to 7 , the working principle is as follows:

[0034] After the airflow enters the splitter 3 through the air inlet pipe, it is divided into two paths, upper and lower, and enters the molding cavity 1 respectively. One path is blown into the molding cavity 1 through the upper air inlet 5, and the other path is blown into the molding cavity 1 through the lower air inlet 7. The two airflows are finally discharged through the exhaust port 9.

[0035] like Figure 4 As shown, the airflow is evenly distributed during the molding printing process.

[0036] like Figure 5 As shown, during the powder spreading process, the scraper passes through the wind field area, disturbing the original wind field, causing the air flow speed in the local area to increase, resulting in the powder blowing phenomenon.

[0037] like Figure 6 As shown, a windshield 6 is arranged at the lower part of the diverter 3, and its angle is controlled by a rotating cylinder 4. When printing and molding, it is in a horizontal state and the airflow passes normally.

[0038] like Figure 7 As shown, when the scraper is spreading the powder, it is rotated to a vertical state, and the air flow mainly enters the molding cavity through the upper air inlet 5, the flow rate of the lower air inlet 7 is reduced, and the wind speed in and out of the powder bed surface 8 is reduced. Figure 4 As shown. The local maximum wind speed after the scraper interference is still lower than the critical wind speed of the powder bed, thereby eliminating the powder blowing phenomenon. After the powder is spread, the rotating cylinder 4 rotates the windshield 6 to make it at a horizontal angle to ensure the wind speed requirements during printing.

[0039] The wind field control mechanism for metal 3D printing provided by the present invention effectively improves the wind speed during the molding process through a reasonably designed wind field control mechanism, thereby improving the molding quality of metal 3D printing. The airflow is evenly distributed in the molding cavity, effectively reducing the risk of uneven cooling and powder particle displacement, and ensuring the accuracy and strength of the printed part. The splitter is fixedly connected to the molding cavity, and the upper air inlet and the lower air inlet are rectangular ports. The U-shaped design of the splitter effectively distributes the airflow evenly to various areas of the molding cavity, improves the distribution and molding quality of the airflow, and reduces the local airflow unevenness. At the same time, the rectangular port design improves the stability of the airflow, reduces the disturbance when entering the molding cavity, and avoids the problem of unstable airflow. The U-shaped splitter reduces the impact of airflow and eddy current, ensures that the airflow enters the molding cavity smoothly, and improves the molding accuracy and surface quality. By optimizing the airflow distribution and flow path, the airflow resistance loss is reduced, the molding efficiency is improved, and the energy consumption is reduced. The fixed connection design improves the sealing between the splitter and the molding cavity, avoids gas leakage or interference, improves the control accuracy of the molding process, and simplifies the maintenance and adjustment process. The method of suppressing powder blowing adjusts the airflow by controlling the state of the wind shield, so that the airflow speed at the lower air inlet during the powder laying process is reduced, reducing powder waste, reducing material costs, and improving the stability of the printing process.

[0040] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A wind field control mechanism for metal 3D printing, comprising a molding cavity (1), having a first side surface and a second side surface arranged opposite to each other, wherein the upper and lower parts of the first side surface are respectively provided with an upper air inlet (5) and a lower air inlet (7), and the lower part of the second side surface is provided with an exhaust port (9), characterized in that: The invention comprises a flow divider (3) connected to a molding cavity (1), wherein the upper and lower ends of the flow divider (3) are respectively connected to an upper air inlet (5) and a lower air inlet (7), and the middle part of the flow divider (3) is connected to an air inlet duct (2). A windshield (6) is arranged inside the flow divider (3), and the windshield (6) is located outside the lower air inlet (7). The windshield (6) is mounted on a rotating shaft (61). A rotating cylinder (4) for driving the rotating shaft (61) to rotate is arranged outside the flow divider (3), and the rotating cylinder (4) is mounted on the flow divider (3).

2. The wind field control mechanism for metal 3D printing according to claim 1, characterized in that: The flow divider (3) is fixedly connected to the molding cavity (1).

3. The wind field control mechanism for metal 3D printing according to claim 2, characterized in that: The upper air inlet (5) and the lower air inlet (7) are rectangular openings, and the diverter (3) is U-shaped.

4. A method for suppressing powder blowing for metal 3D printing, wherein a first side surface and a second side surface are arranged opposite to each other in a molding cavity (1), an upper air inlet (5) and a lower air inlet (7) are arranged at the upper and lower parts of the first side surface respectively, and an exhaust port (9) is arranged at the lower part of the second side surface, characterized in that: These strategies include: An air flow is introduced into the splitter (3) through an air inlet pipe (2), and the air flow is split into two paths in the splitter (3), and enters the molding cavity (1) through an upper air inlet (5) and a lower air inlet (7) respectively, and the air flow is finally discharged through an exhaust port (9); During the printing and molding process, the windshield (6) is controlled to be in a horizontal state, so that the airflow evenly enters the molding cavity (1) through the upper air inlet (5) and the lower air inlet (7), thereby ensuring the airflow distribution during the printing and molding process; During the powder spreading process, the windshield (6) is rotated to a vertical state by controlling the rotating cylinder (4), thereby reducing the air flow velocity through the lower air inlet (7), reducing the local wind speed on the powder bed surface (8), avoiding the powder blowing phenomenon caused by the interference of the scraper, and thus reducing the waste of powder; After the powder spreading is completed, the wind shield (6) is controlled to rotate to a horizontal state again to restore the wind speed conditions required in the printing and molding process.

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