Self-adaptive vortex air curtain local protection device and method for laser melting deposition technology

Abstract

The invention discloses a self-adaptive vortex air curtain local protection device and method for a laser melting deposition technology, and aims to solve the problems that in the field of additive manufacturing, the part size is gradually increased, and a protection cavity is limited by manufacturing and using cost and cannot be correspondingly increased. The device comprises a laser head, a vortex airflow generator, an annular gas rectifier, an annular powder feeding nozzle, a barometer, an oxygen analyzer, a computer control system and the like. Guide vanes are arranged in the vortex airflow generator and used for forming vortex airflow to be sprayed outwards, and a local low-pressure area is formed in the vortex airflow generator so as to isolate the additive area from outside air. And the annular gas rectifier is used for forming an annular gas curtain to further isolate the additive area from external air. The barometer and the oxygen analyzer are used for dynamically monitoring the air pressure and the oxygen content of the additive area and feeding back monitoring signals to the computer control system. And the computer control system performs closed-loop control on the gas flow of the vortex airflow generator and the tilting angle of the blade according to the monitoring result, so that self-adaptive adjustment is realized, the oxygen content of the additive area is reduced to a specified value, and the requirement of additive manufacturing is met. By means of the local protection mode, effective protection of the large part additive manufacturing process is achieved, the manufacturing cost is reduced, and the production efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing (3D printing) technology, and particularly to an adaptive vortex air curtain local protection device and method for laser melting deposition technology, which is especially suitable for laser additive manufacturing of large metal parts. Background Technology

[0002] With the rapid development of additive manufacturing (3D printing) technology, it has been widely applied in aerospace, medical devices, and automotive manufacturing. Laser melting deposition technology, as an important metal 3D printing technology, can manufacture metal parts with complex shapes and excellent performance. However, during the laser melting deposition process, the molten metal pool is highly susceptible to the effects of oxygen in the air, leading to defects such as oxidation and porosity, thereby reducing the performance and reliability of the parts. Therefore, effective protection of the additive manufacturing area is crucial.

[0003] Traditional additive manufacturing protection methods typically employ a closed protective cavity, which is then filled with an inert gas to isolate it from air. However, as part sizes continue to increase, the manufacturing cost and volume of closed protective cavities also rise dramatically, posing significant economic and technical challenges. Therefore, how to effectively protect large additively manufactured parts without excessively increasing the volume and cost of the protective cavity has become a pressing technical problem to be solved in this field. Summary of the Invention

[0004] The purpose of this invention is to provide an adaptive vortex air curtain local protection device and method for laser melting deposition technology, so as to solve the problems mentioned in the background art, achieve effective protection of large parts in the additive manufacturing process, and improve the performance and reliability of the parts.

[0005] To achieve the above objectives, the present invention provides the following technical solution.

[0006] An adaptive vortex gas curtain local protection device for laser melting deposition technology, characterized in that it comprises: a laser head 1 for emitting a laser beam to melt metal powder; a vortex gas flow valve 2, arranged around the laser head 1 for conveying inert gas; a gas curtain valve 3, arranged around the laser head 1 and opposite to the vortex gas flow valve 2, for forming an auxiliary gas curtain; a lens protection valve 4, arranged on the front of the laser head 1 for protecting the internal optical lenses of the laser head; a vortex gas flow generator 5, arranged at the lower part of the laser head 1, with multiple tiltable guide vanes 52 arranged in a ring on its inner side for adjusting the flow direction of the inert gas to form a vortex-shaped gas flow; and an annular gas rectifier 6, coaxially arranged inside the vortex gas flow generator 5, with internal components... A gas rectifier 63 is used to organize the vortex airflow into a parallel airflow to form an annular air curtain; a linkage mechanism, including a drive gear 53 and an annular rack 62, is used to synchronously adjust the tilt angle of the guide vane 52 and the gas flow rate of the annular gas rectifier 6; an annular powder feeder 7 is coaxially arranged inside the annular gas rectifier 6 and is used to transport metal powder to the laser melting pool; a pressure gauge 8 and an oxygen analyzer 9 are arranged below the annular powder feeder 7 and are used to monitor the pressure and oxygen content in the additive manufacturing zone in real time; a computer control system 10 is connected to the pressure gauge 8, the oxygen analyzer 9, the vortex airflow valve 2, and the vortex airflow generator 5 and is used to dynamically adjust the tilt angle of the guide vane 52 and the gas flow rate according to the monitoring data to keep the oxygen content in the additive manufacturing zone below a preset threshold.

[0007] In one possible implementation, multiple guide vanes 52 are distributed in a ring inside the vortex airflow generator 5. The tilt angle of the guide vanes 52 is driven by a servo motor 51, and the angle adjustment range is 0° to 30°. A drive gear 53 is fixedly connected to the inner side of the servo motor 51. The drive gear 53 meshes with the annular rack 62 of the annular gas rectifier 6 to realize the linkage control between the guide vanes 52 and the annular gas rectifier 6.

[0008] In one possible implementation, the annular gas rectifier 6 includes an airflow regulating ring 61 and a gas rectifier 63. The airflow regulating ring 61 meshes with a drive gear 53 via an annular rack 62. When the tilt angle of the guide vane 52 increases, the airflow regulating ring 61 aligns with the gas rectifier 63 to increase the gas flow rate, and vice versa to reduce the gas flow rate.

[0009] In one possible implementation, the computer control system 10 presets an oxygen content threshold and a target pressure range. When the oxygen content exceeds the threshold or the pressure is below the target range, the tilt angle of the guide vane 52 and the gas flow rate are increased. When the oxygen content is below the threshold and the pressure is above the target range, the tilt angle of the guide vane 52 and the gas flow rate are decreased.

[0010] Compared with the prior art, the beneficial effects of the present invention are:

[0011] This invention provides an adaptive vortex air curtain local protection device and method for laser melting deposition technology. Compared with the prior art, this invention provides local atmosphere protection for the additive manufacturing area through an airflow generator and an annular gas rectifier. It also dynamically monitors the air pressure and oxygen content in the additive manufacturing area through a barometer, oxygen analyzer, and computer control system, and adjusts the gas flow rate and guide vane angle of the vortex airflow generator. This invention is particularly suitable for additive manufacturing of large metal parts, improves processing efficiency, reduces inert gas consumption, and has significant economic and technical implications. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the overall structure of an adaptive vortex air curtain local protection device for laser melting deposition technology according to the present invention;

[0013] Figure 2 This is a schematic diagram of the internal structure of an adaptive vortex air curtain local protection device for laser melting deposition technology according to the present invention;

[0014] Figure 3 This is a schematic diagram of the assembly of the vortex airflow generator and the annular gas rectifier in an adaptive vortex air curtain local protection device for laser melting deposition technology according to the present invention.

[0015] In the diagram: 1. Laser head; 2. Vortex airflow valve; 3. Air curtain valve; 4. Lens protection valve; 5. Vortex airflow generator; 51. Servo motor; 52. Guide vane; 53. Drive gear; 6. Annular gas rectifier; 61. Airflow regulating ring; 62. Annular rack; 63. Gas rectification device; 7. Annular powder feeder; 8. Pressure gauge; 9. Oxygen analyzer; 10. Computer control system; Detailed Implementation

[0016] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," "side," and "side edge," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for 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 the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0018] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0019] The technical solutions in the embodiments of the present invention will now be clearly and completely described with reference to the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0020] This invention provides an adaptive vortex gas curtain local protection device for laser melting deposition technology, such as... Figure 1 and Figure 2 As shown, the device includes a laser head 1, a vortex airflow valve 2, an air curtain valve 3, a lens protection valve 4, a vortex airflow generator 5, an annular gas rectifier 6, an annular powder feeder 7, a pressure gauge 8, an oxygen analyzer 9, and a computer control system 10.

[0021] Specifically, using, such as Figure 1 The apparatus shown performs laser melting deposition on TC4 titanium alloy. The laser melting deposition system is started, and the laser power is set to 1200W, the scanning speed to 10mm / s, and the powder feed rate to 6g / min. Simultaneously, the control parameters of the computer control system 10 are set, including an oxygen content threshold of 200ppm, a target gas pressure of 0.96MPa, an initial flow rate of 25L / min for the vortex airflow valve 2, an initial flow rate of 10L / min for the air curtain valve 3, a flow rate of 15L / min for the lens protection valve 4, and an initial blade angle of 20° for the vortex airflow generator 5.

[0022] Specifically, such as Figure 2 and Figure 3As shown, when the oxygen analyzer 9 detects that the oxygen content in the additive manufacturing area has dropped below 200 ppm, the additive manufacturing operation is automatically started. During the additive manufacturing process, the barometer 8 and the oxygen analyzer 9 monitor the air pressure and oxygen content in the additive manufacturing area in real time and transmit the data to the computer control system 10. The computer control system 10 compares the received air pressure and oxygen content data with the preset target values. If the actual deviation is greater than the set allowable range, the computer control system 10 will adjust the flow rate of the vortex airflow valve 2 and the blade angle of the vortex airflow generator 5 according to the preset control algorithm, thereby adjusting the flow rate and intensity of the vortex airflow. At the same time, the drive gear 53 adjusts the airflow regulating ring 61 through the ring rack 62 to keep the air pressure and oxygen content in the additive manufacturing area within the target range.

[0023] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. An adaptive vortex gas curtain local protection device for laser melting deposition technology, characterized in that, include: A laser head (1) is used to emit a laser beam to melt metal powder; a vortex airflow valve (2) is arranged around the laser head (1) to transport inert gas; an air curtain valve (3) is arranged around the laser head (1) and opposite to the vortex airflow valve (2) to form an auxiliary air curtain; a lens protection valve (4) is arranged on the front of the laser head (1) to protect the internal optical lens of the laser head; a vortex airflow generator (5) is arranged at the lower part of the laser head (1), with multiple tiltable guide vanes (52) arranged in a ring on its inner side to adjust the flow direction of the inert gas to form a vortex airflow; an annular gas rectifier (6) is coaxially arranged inside the vortex airflow generator (5), and has a gas rectifier (63) inside to rectify the vortex airflow. Parallel airflow forms an annular air curtain; a linkage mechanism, including a drive gear (53) and an annular rack (62), is used to synchronously adjust the tilt angle of the guide vane (52) and the gas flow rate of the annular gas rectifier (6); an annular powder feeder (7), coaxially arranged inside the annular gas rectifier (6), is used to transport metal powder to the laser melting pool; a pressure gauge (8) and an oxygen analyzer (9), arranged below the annular powder feeder (7), are used to monitor the pressure and oxygen content of the additive manufacturing zone in real time; a computer control system (10), connected to the pressure gauge (8), oxygen analyzer (9), vortex airflow valve (2) and vortex airflow generator (5), is used to dynamically adjust the tilt angle of the guide vane (52) and the gas flow rate according to the monitoring data, so that the oxygen content of the additive manufacturing zone is maintained below a preset threshold.

2. The adaptive vortex gas curtain local protection device for laser melting deposition technology according to claim 1, characterized in that, The vortex airflow generator (5) has multiple guide vanes (52) arranged in a ring. The tilt angle of the guide vanes (52) is driven by a servo motor (51), and the angle adjustment range is 0° to 30°. A drive gear (53) is fixedly connected to the inner side of the servo motor (51). The drive gear (53) meshes with the ring rack (62) of the ring gas rectifier (6) to realize the linkage control between the guide vanes (52) and the ring gas rectifier (6).

3. The adaptive vortex gas curtain local protection device for laser melting deposition technology according to claim 1, characterized in that, The annular gas rectifier (6) includes an airflow regulating ring (61) and a gas rectifier (63). The airflow regulating ring (61) meshes with the drive gear (53) through an annular rack (62). When the tilt angle of the guide vane (52) increases, the airflow regulating ring (61) and the gas rectifier (63) are aligned to increase the gas flow rate, and vice versa to reduce the gas flow rate.

4. The adaptive vortex gas curtain local protection device for laser melting deposition technology according to claim 1, characterized in that, The computer control system (10) presets an oxygen content threshold and a target air pressure range. When the oxygen content exceeds the threshold or the air pressure is lower than the target range, it increases the tilt angle of the guide vane (52) and the gas flow rate. When the oxygen content is lower than the threshold and the air pressure is higher than the target range, it decreases the tilt angle of the guide vane (52) and the gas flow rate.

5. A method for local protection of an adaptive vortex gas curtain in laser melting deposition technology, characterized in that, The adaptive vortex gas curtain local protection device for laser melting deposition technology is implemented using the equipment described in any one of claims 1 to 4, and the method of using the adaptive vortex gas curtain local protection device for laser melting deposition technology includes the following steps: Step 1: Activate the adaptive vortex air curtain local protection device of the laser melting deposition technology, and set the oxygen content threshold and target air pressure range through the computer control system (10). Based on the properties and geometric dimensions of the material to be processed, the initial gas flow rate and blade tilt angle of the vortex airflow generator (5) are preset; Step 2: Start the laser melting deposition process. The vortex airflow valve (2), the air curtain valve (3) and the lens protection valve (4) start to deliver inert gas, forming a local low pressure and inert gas protection zone in the additive manufacturing area. Step 3: The barometer (8) and oxygen analyzer (9) monitor the air pressure and oxygen content in the additive manufacturing area in real time and transmit the monitoring signals to the computer control system (10). When the oxygen content in the additive manufacturing area drops to the target value, the annular powder feeding nozzle (7) starts to feed out continuous and uniform annular powder and starts the additive manufacturing operation. Step 4: During the additive manufacturing process, the oxygen content and air pressure in the additive manufacturing area are simultaneously monitored. When the oxygen content exceeds the preset threshold or the air pressure is lower than the target range, the computer control system (10) instructs the vortex airflow generator (5) to increase the gas flow rate or adjust the blade tilt angle to a larger angle to enhance the coverage and intensity of the vortex airflow. When the oxygen content is lower than the preset threshold and the air pressure is higher than the target range, the computer control system (10) instructs the vortex airflow generator (5) to reduce the gas flow rate or adjust the blade tilt angle to a smaller angle to reduce the airflow intensity and avoid interfering with the processing. In this process, the vortex airflow generator (5) is linked with the annular gas rectifier (6) to protect the additive manufacturing area and save inert gas.

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