Air inlet and powder laying device capable of being regulated and controlled in partition mode and laser melting equipment

Abstract

The invention discloses an air inlet and powder spreading device capable of being regulated and controlled in a partitioned mode and laser melting equipment. The equipment comprises a forming cabin, a honeycomb type air inlet device connected with an atmosphere circulating system and capable of being regulated and controlled in the partitioned mode, a powder spreading device capable of being regulated and controlled in the partitioned mode, an industrial control computer and a control system. The air inlet device divides a honeycomb type air inlet into four air inlet areas, and a branch air delivery pipe of each area is provided with an electric rectangular louver valve provided with a valve positioner; the powder spreading device divides the forming cylinder into three powder spreading areas, and a lifting platform in each area is mechanically connected with a ball screw provided with a servo motor. An industrial control computer processes a geometric model to determine a forming area, and a control system synchronously controls an electric rectangular louver valve to adjust the opening degree so as to control protective gas parameters and controls a ball screw to adjust a lifting powder laying area so as to control the powder filling amount, so that air inlet and powder laying are cooperatively regulated and controlled, and the utilization rate of protective gas and metal powder is increased; the overall energy consumption of equipment is reduced.

Description

Technical Field

[0001] This invention relates to the field of laser powder bed melting equipment, specifically to a zone-controlled air inlet and powder spreading device and laser melting equipment. Background Technology

[0002] Fixed-size forming cylinders present challenges in dynamically adjusting to changes in the size and structure of the formed parts, limiting metal powder utilization and equipment processing efficiency. Fixed, simple air nozzles, due to their simple structure and lack of effective airflow integration and guidance, easily cause interference between airflow and the internal structure and the parts themselves, generating eddies and dead zones. This further leads to uneven flow field distribution above the forming area, with significant differences in airflow velocity and direction at different locations, thus weakening the efficiency of spatter removal. Simultaneously, turbulent airflow can cause the high-temperature molten pool to react with oxygen, producing oxides and affecting process quality. Static inlet and outlet structures and turbulence component arrangements also generally lack adjustability and controllability, failing to flexibly adapt to complex working conditions with different sizes and special structures. This not only limits equipment processing efficiency but also fails to optimize gas consumption. Although some actively adjustable air inlet devices exist on the market, capable of actively intervening in the airflow to meet different processing needs, these devices are typically complex in structure, expensive to manufacture, and lack sufficient reliability in long-term operation. Furthermore, these air inlet devices generally lack the ability to match and control the powder spreading device according to the laser melting area. This results in the inability to flexibly adjust the protective gas airflow area and the metal powder spreading range according to the actual size of the molded parts when the equipment does not need to print the full width. This leads to redundant waste of protective gas and metal powder. Therefore, it is necessary to design a zone-controlled air intake and powder spreading device and a laser melting equipment to solve this problem. Summary of the Invention

[0003] The purpose of this invention is to provide a zone-controlled air inlet and powder spreading device and a laser melting equipment to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] The adjustable air inlet and powder spreading device and laser melting equipment include an industrial control computer, an industrial control computer host, an industrial control computer operation panel, an air inlet device, several air supply pipelines, four branch air storage cavities, a honeycomb air inlet structure, an electric rectangular louver valve, a powder spreading device, a forming cylinder, a ball screw and a control system.

[0006] The industrial control computer is set up side by side with the forming chamber in the form of an independent control cabinet and is electrically and data connected via cables. The industrial control computer host is used to process the three-dimensional model data, determine the actual forming area of ​​the metal part to be processed on the forming substrate, and transmit it to the control system and the industrial control computer operation panel in the form of electrical signals. The industrial control computer operation panel converts the electrical signals into a visual image of the actual forming area and provides a human-machine interface for setting and confirming the forming area and related process parameters.

[0007] The air intake device is installed on one side of the forming chamber and is housed inside the protective shell of the laser powder bed melting equipment. Its upstream air intake is connected to the protective gas circulation system through the air inlet of the air supply pipeline, and its downstream air intake is connected to the forming chamber through the air outlet of the honeycomb-shaped air inlet structure. The air supply pipeline is provided with a main air supply pipe located upstream of the air intake and four branch air supply pipes located downstream of the air intake. The air outlet of the air supply pipeline is connected to the air inlet of the corresponding branch air storage cavity.

[0008] The powder spreading device is installed at the bottom of the forming chamber and is housed within the protective shell of the laser powder bed melting equipment. Its forming cylinder is assembled from a detachable forming substrate and three lifting platforms. The forming substrate is sealed to the bottom of the forming chamber. The entire structure consists of a large-format forming substrate, divided into three mutually sealed and isolated powder spreading areas: a central powder spreading area, a left powder spreading area, and a right powder spreading area. Each area corresponds to and is fixedly connected to a lifting platform. The bottom of each lifting platform is controlled by a ball screw driven by a servo motor, which is electrically connected to the control system via cables.

[0009] The control system is a programmable logic controller, installed below the molding chamber and adjacent to its right side, and housed together inside the protective shell of the laser powder bed melting equipment. It is electrically and data connected to the industrial control computer host, the valve positioner of the electric rectangular louver valve, and the servo motor of the ball screw through cables.

[0010] As a further aspect of the present invention: the air inlet ports of the four branch air storage cavities are connected to the air outlets of the corresponding branch air supply pipes, and the air outlet ports are connected to the honeycomb-shaped air inlet structure.

[0011] As a further aspect of the present invention: each of the four branch gas storage cavities is provided with several sets of equidistant arc-shaped guide plates and a porous medium rectifier plate located downstream of it.

[0012] As a further aspect of the present invention: the air inlet port of the honeycomb air inlet structure is connected to the air outlet port of the four branch air storage cavities. The structure as a whole is composed of a honeycomb rectifier plate and is divided into four air inlet areas that are isolated from each other by protective air: the central air inlet area, the upper air inlet area, the left air inlet area and the right air inlet area. Each area corresponds to and is connected to the air outlet port of the branch air storage cavity.

[0013] As a further aspect of the present invention: each of the four branch gas pipelines is equipped with an electric rectangular louvered valve with a valve positioner at its air inlet end, and the valve positioner is electrically connected to the control system via a cable.

[0014] As a further aspect of the present invention: the honeycomb-shaped air inlet structure integrates the airflow originating from the branched air storage cavity into a laminar flow with uniform distribution and basically consistent flow velocity, and then transports it to the forming chamber.

[0015] Compared with existing technologies, the beneficial effects of this invention are as follows: The adjustable air inlet device, powder spreading device, and laser powder bed melting equipment involved in this invention transform the static and fixed air inlet structure and forming cylinder into a dynamically adjustable air inlet and powder spreading device, which is integrated into the laser powder bed melting equipment and achieves collaborative operation under the coordinated control of the control system. The forming area is determined by processing the geometric model through an industrial control computer, and the control system synchronously controls the electric rectangular louver valve and the ball screw accordingly. The former controls the protective gas parameters by adjusting the opening, while the latter controls the powder filling amount by adjusting the lifting and lowering of the powder spreading area, thereby achieving coordinated control of air inlet and powder spreading. This invention improves the utilization rate of protective gas and metal powder, reduces the overall energy consumption of the equipment, and ensures the stability of the forming process and the process quality of the formed parts. Attached Figure Description

[0016] Figure 1 A schematic diagram of an embodiment of the laser powder bed melting device of the present invention;

[0017] Figure 2 A front view frame diagram of an embodiment of the laser powder bed melting equipment of the present invention;

[0018] Figure 3 A schematic diagram of the structure of an embodiment of the powder spreading device of the present invention;

[0019] Figure 4 This is a top view of an embodiment of the air intake device of the present invention and a cross-sectional view of its honeycomb-shaped air intake structure.

[0020] In the diagram: 1. Industrial control computer; 2. Air inlet device; 3. Powder spreading device; 4. Control system; 5. Cables; 6. Molding chamber; 7. Protective casing; 11. Industrial control computer host; 12. Industrial control computer operation panel; 13. Independent control cabinet; 21. Main air supply pipe; 23. Branch air supply pipe; 24. Branch air storage cavity; 25. Honeycomb air inlet structure; 31. Molding cylinder; 33. Powder cylinder; 34. Powder recovery cylinder; 35. Guide rail 36. Powder spreading scraper; 241. Arc-shaped guide plate; 242. Porous medium rectifier plate; 251. Central air inlet area; 252. Left air inlet area; 253. Top air inlet area; 254. Right air inlet area; 261. Electric rectangular louver valve; 262. Valve positioner; 311. Molding substrate; 312. Lifting platform; 321. Ball screw; 322. Servo motor; 3111. Central powder spreading area; 3112. Left powder spreading area; 3113. Right powder spreading area. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. 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.

[0022] Please see Figures 1-4As an embodiment of the present invention, a powder spreading device and laser melting equipment with zoned adjustable air intake include an industrial control computer 1, an industrial control computer host 11, an industrial control computer operation panel 12, an air intake device 2, several air supply pipelines, four branch air storage cavities 24, a honeycomb-shaped air inlet structure 25, an electric rectangular louvered valve 261, a powder spreading device 3, a forming cylinder 31, a ball screw 321, and a control system 4; the industrial control computer 1 is arranged side by side with the forming chamber 6 in the form of an independent control cabinet 13, and is electrically and data connected through cables 5; the industrial control computer host 11 is used to process three-dimensional model data and determine the metal to be processed. The actual molding area of ​​the part on the molding substrate 311 is transmitted to the control system 4 and the industrial control computer operation panel 12 in the form of electrical signals. The industrial control computer operation panel 12 converts the electrical signals into a visual image of the actual molding area and provides a human-machine interface for setting and confirming the molding area and related process parameters. The air inlet device 2 is installed on one side of the molding chamber 6 and is housed inside the protective shell 7 of the laser powder bed melting equipment. Its upstream air inlet is connected to the protective gas circulation system through the air inlet of the air supply pipeline, and its downstream air inlet is connected to the molding chamber 6 through the air outlet of the honeycomb air inlet structure 25. The air supply pipeline is provided with A main air supply pipe 21 located upstream of the air intake and four branch air supply pipes 23 located downstream of the air intake, with the air outlets of the air supply pipes respectively connected to the air inlet ports of the corresponding branch air storage cavities 24; the powder spreading device 3 is installed at the bottom of the forming chamber 6 and is housed inside the protective shell 7 of the laser powder bed melting equipment. Its forming cylinder 31 is assembled from a detachable forming substrate 311 and three lifting platforms 312; the forming substrate 311 is sealed to the bottom of the forming chamber 6. The entire structure is composed of a large-format forming substrate 311 and is divided into three mutually sealed and isolated powder spreading areas: the central powder spreading area 3111, the left powder spreading area 3112, and the right powder spreading area 3112. Each area, including the right powder-laying area 3113, corresponds to and is fixedly connected to the lifting platform 312. The bottom of each lifting platform 312 is controlled by a ball screw 321 driven by a servo motor 322. The servo motor 322 is electrically connected to the control system 4 via cable 5. The control system 4 is a programmable logic controller (PLC), installed below and near the right side of the molding chamber 6, and housed within the protective housing 7 of the laser powder bed melting equipment. It is electrically and data-connected to the industrial control computer host 11, the valve positioner 262 of the electric rectangular louver valve 261, and the servo motor 322 of the ball screw 321 via cable 5. The air inlet ports of the four branch air storage cavities 24 are connected to the air outlet ports of the corresponding branch air supply pipes 23, and the air outlet ports are connected to the honeycomb-shaped air inlet structure 25. Each of the four branch air storage cavities 24 contains several sets of equidistant arc-shaped guide plates 241 and a porous medium rectifier plate 242 located downstream of each guide plate.The honeycomb-shaped air inlet structure 25 connects to the air outlets of the four branch air storage cavities 24. The structure is composed of a honeycomb-shaped rectifier plate and is divided into four mutually isolated air inlet areas: a central air inlet area 251, an upper air inlet area 253, a left air inlet area 252, and a right air inlet area 254. Each area corresponds to and is connected to the air outlet of the branch air storage cavity 24. Each of the four branch air supply pipes 23 is equipped with an electrically operated rectangular louvered valve 261 with a valve positioner 262. The valve positioner 262 is electrically connected to the control system 4 via a cable 5. The honeycomb-shaped air inlet structure 25 integrates the airflow originating from the branch air storage cavities 24 into a uniformly distributed laminar flow with a relatively consistent velocity, and then delivers it to the forming chamber 6.

[0023] Before the equipment is turned on, the entire system is in standby initialization mode. The electric rectangular louvered valves 261 at the air inlet ends of the branch air supply pipes 23 in the air inlet device 2 are all closed. There is no protective gas flow in the main air supply pipe 21, branch air supply pipes 23, branch air storage cavities 24, and honeycomb air inlet structure 25, and the internal environment of the forming chamber 6 is open to the atmosphere. The ball screws 321 in the powder spreading device 3 are all at their highest limit, and the connected servo motors 322 are all de-energized. The upper surface of the corresponding lifting platform 312 is flush with the bottom surface inside the forming chamber 6. Simultaneously, the industrial control computer 1 and the control system 4 are both de-energized.

[0024] After the equipment is turned on, it enters the collaborative preparation process of powder laying and protective atmosphere establishment. Regarding powder laying: the industrial control computer 1 receives and processes the 3D model data imported by the user, and then determines the actual forming area of ​​the metal part to be processed on the forming substrate 311 according to the user's instructions. The actual forming area information is then transmitted as an electrical signal to the control system 4 and the industrial control computer operation panel 12 via cable 5. The user can install the forming substrate 311 on the corresponding lifting platform 312 according to the displayed actual forming area. Subsequently, the control system 4 sends instructions to the servo motors 322 corresponding to the lifting platforms 312 and powder cylinders 33 of each powder-laying area, driving the ball screws 321 to move, making the upper surface of the forming substrate 311 corresponding to the non-forming area flush with the bottom surface of the forming chamber 6, while the forming substrate 311 corresponding to the forming area is pre-lowered by one powder layer thickness; simultaneously, the powder cylinder 33 is raised accordingly. Next, the powder-spreading scraper 36 begins operation, precisely scraping the metal powder supplied by the powder cylinder 33 onto the corresponding forming substrate 311 in the forming area, forming a thin layer of powder with uniform thickness, density, and a smooth surface. Excess metal powder scraped from the forming area is then scraped into the powder recovery cylinder 34. Regarding the establishment of the protective atmosphere: the protective gas circulation system begins operation, and the control system 4 synchronously sends commands to the valve positioners 262 in each air inlet area, causing the electric rectangular louver valves 261 to rotate to their maximum opening parallel to the airflow direction under the drive of each valve positioner 262. The protective gas flows along the following path to establish the protective atmosphere: the protective gas originating from the protective gas circulation system first flows in from the main gas supply pipe 21. After being split, the gas is transported through four branch gas supply pipes 23 to the corresponding four branch gas storage cavities 24. Within the branch gas storage cavities 24, the concentrated airflow is distributed, guided, and diffused by several sets of equidistant arc-shaped guide plates 241, transforming into a dispersed airflow with reduced velocity. Subsequently, the dispersed airflow is combed by the porous medium rectifier plate 242 located downstream of the arc-shaped guide plate 241 and vertically sent into the honeycomb air inlet structure 25. Each independent section of the honeycomb air inlet structure 25 integrates the airflow from the corresponding branch storage cavity 24 into a uniformly distributed laminar flow with a stable velocity, and finally delivers it to the forming chamber 6.

[0025] Furthermore, after the preparation process is completed, the control system 4 performs corresponding controls according to the different conditions of the molded parts to be processed:

[0026] Furthermore, if the part to be processed is a small or medium-sized part, in terms of powder spreading control, the control system 4 sends a command to control the servo motor 322 corresponding to the central powder spreading area 3111 to drive the ball screw 321 to move, so that the molding substrate 311 drops by one powder layer thickness after each powder layer is laid, while the height of the molding substrate 311 corresponding to other powder spreading areas remains unchanged; at this time, the powder spreading scraper 36 scrapes the metal powder supplied by the powder cylinder 33 onto the surface of the molding substrate 311, forming a uniform and dense powder layer, and scrapes the excess powder into the powder recovery cylinder 34. In terms of air intake control, the control system 4 sends a command to control the electric rectangular louver valve 261 on the branch corresponding to the central air intake area 251 to maintain the valve plate at its maximum opening parallel to the airflow direction, and closes the electric rectangular louver valves 261 corresponding to other air intake areas. At this time, the protective gas only enters the molding chamber 6 through the branch corresponding to the central air intake area 251, forming a local concentrated air field covering the part processing area.

[0027] Furthermore, if the part to be processed is a large-format part or the processing task requires covering most of the forming surface, in terms of powder spreading control, the control system 4 sends instructions to control the servo motor 322 corresponding to each powder spreading area to drive the ball screw 321 to move, so that each forming substrate 311 drops by one powder layer thickness after each layer of powder is spread. At this time, the powder spreading scraper 36 scrapes the metal powder supplied by the powder cylinder 33 onto the surface of each forming substrate 311, forming a uniform and dense powder layer, and scrapes the excess powder into the powder recovery cylinder 34. In terms of air intake control, the control system 4 sends instructions to control the electric rectangular louver valves 261 on the branches corresponding to multiple air intake areas to maintain the maximum opening parallel to the airflow direction, while closing the electric rectangular louver valves 261 on the branches corresponding to other air intake areas. At this time, the protective gas enters the forming chamber 6 through the branches corresponding to multiple air intake areas, forming a large-format laminar flow air field with uniform width and stable flow rate, ensuring that each processing area of ​​the large-format part receives effective spatter removal and atmosphere protection.

[0028] Furthermore, if the processing generates a large amount of high-speed splashes or the protective airflow is affected by the splashes and diffuses upwards, in terms of air intake control, the control system 4 will send a command to synchronously control the electric rectangular louver valve 261 on the corresponding branch of the upper air intake zone 253 to rotate to a larger opening, while the electric rectangular louver valves 261 on the corresponding branches of other air intake zones will rotate to a smaller opening. At this time, the two airflows form a velocity difference in the forming chamber 6, generating a downward shearing force, effectively guiding the airflow direction and suppressing the upward diffusion of splashes.

[0029] Furthermore, after the printing process is complete, regarding air intake control, the control system 4 sends a command to control the electric rectangular louver valve 261 at the air intake end of the branch air supply pipe 23 to rotate to the closed state. At this time, there is no protective gas flow in the main air supply pipe 21, the branch air supply pipe 23, the branch air storage cavity 24, and the honeycomb air inlet structure 25. The residual protective gas in the forming chamber 6 is discharged by the exhaust system and filtered and recovered, and finally the internal environment of the forming chamber 6 is restored to be open to the atmosphere.

[0030] Furthermore, during the equipment shutdown process, the entire system returns to standby initialization state. The control system 4 sends a command to control the servo motor 322 in the powder spreading device 3 to drive the ball screw 321 to return to and maintain its highest limit position, and the upper surface of the corresponding lifting platform 312 returns to and maintains flush with the bottom surface inside the forming chamber 6. Finally, the industrial control computer 1, the servo motor 322, and the control system 4 all return to the power-off state.

[0031] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0032] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A zone-controlled air inlet and powder spreading device and laser melting equipment, characterized in that, It includes an industrial control computer, an industrial control computer host, an industrial control computer operation panel, an air inlet device, several air supply pipelines, four branch air storage cavities, a honeycomb air inlet structure, an electric rectangular louver valve, a powder spreading device, a forming cylinder, a ball screw, and a control system. The industrial control computer is set up side by side with the forming chamber in the form of an independent control cabinet and is electrically and data connected via cables. The industrial control computer host is used to process the three-dimensional model data, determine the actual forming area of ​​the metal part to be processed on the forming substrate, and transmit it to the control system and the industrial control computer operation panel in the form of electrical signals. The industrial control computer operation panel converts the electrical signals into a visual image of the actual forming area and provides a human-machine interface for setting and confirming the forming area and related process parameters. The air intake device is installed on one side of the forming chamber and is housed inside the protective shell of the laser powder bed melting equipment. Its upstream air intake is connected to the protective gas circulation system through the air inlet of the air supply pipeline, and its downstream air intake is connected to the forming chamber through the air outlet of the honeycomb-shaped air inlet structure. The air supply pipeline is provided with a main air supply pipe located upstream of the air intake and four branch air supply pipes located downstream of the air intake. The air outlet of the air supply pipeline is connected to the air inlet of the corresponding branch air storage cavity. The powder spreading device is installed at the bottom of the forming chamber and is housed within the protective shell of the laser powder bed melting equipment. Its forming cylinder is assembled from a detachable forming substrate and three lifting platforms. The forming substrate is sealed to the bottom of the forming chamber. The entire structure consists of a large-format forming substrate, divided into three mutually sealed and isolated powder spreading areas: a central powder spreading area, a left powder spreading area, and a right powder spreading area. Each area corresponds to and is fixedly connected to a lifting platform. The bottom of each lifting platform is controlled by a ball screw driven by a servo motor, which is electrically connected to the control system via cables. The control system is a programmable logic controller, installed below the molding chamber and adjacent to its right side, and housed together inside the protective shell of the laser powder bed melting equipment. It is electrically and data connected to the industrial control computer host, the valve positioner of the electric rectangular louver valve, and the servo motor of the ball screw through cables.

2. The zone-adjustable air inlet and powder spreading device and laser melting equipment according to claim 1, characterized in that, The air inlet ports of the four branch air storage cavities are connected to the air outlet ports of the corresponding branch air supply pipes, and the air outlet ports are connected to the honeycomb-shaped air inlet structure.

3. The zone-adjustable air inlet and powder spreading device and laser melting equipment according to claim 1, characterized in that, Each of the four branch gas storage cavities is equipped with several sets of equidistant arc-shaped guide plates and a porous medium rectifier plate located downstream of them.

4. The zone-adjustable air inlet and powder spreading device and laser melting equipment according to claim 1, characterized in that, The honeycomb-shaped air inlet structure has its air inlet port connected to the air outlet ports of the four branch air storage cavities. The structure is composed of a honeycomb-shaped rectifier plate and is divided into four air inlet areas that are isolated from each other by protective air: the central air inlet area, the upper air inlet area, the left air inlet area, and the right air inlet area. Each area corresponds to and is connected to the air outlet port of the branch air storage cavity.

5. The zone-adjustable air inlet and powder spreading device and laser melting equipment according to claim 1, characterized in that, Each of the four branch gas pipelines is equipped with an electric rectangular louvered valve with a valve positioner at its inlet end. The valve positioner is electrically connected to the control system via a cable.

6. The zone-adjustable air inlet and powder spreading device and laser melting equipment according to claim 1, characterized in that, The honeycomb-shaped air inlet structure integrates the airflow originating from the branched air storage cavity into a laminar flow with uniform distribution and basically consistent flow velocity, and then delivers it to the forming chamber.

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