A multi-stage forming cylinder lift platform for an LPBF device

Abstract

The present application relates to the technical field of additive manufacturing, and particularly relates to a multi-section forming cylinder lifting platform for an LPBF device, which comprises a support plate, a multi-section forming cylinder assembly arranged on the support plate and stacked in a vertical direction by a plurality of section forming cylinders, a lifting driving assembly, a dynamic sealing assembly slidingly arranged in a forming chamber, a detection and control unit, a heating rod, a temperature sensor and a photoelectric sensor, a positioning pin, a sealing groove and sealing glue are arranged on a matching surface of adjacent section forming cylinders, corners of an inner wall of the forming chamber are all in a round corner structure, a high-temperature-resistant sealing ring is arranged on an edge of the dynamic sealing assembly to slide against the inner wall, and a first grating ruler directly connected with a servo driver is configured to form a hardware-level full-closed loop control. The present application breaks the bottleneck of difficult processing and easy powder and air leakage in splicing of a large-depth forming cylinder, completely eliminates a right-angle sealing dead angle and prevents platform deflection, and has the significant advantages of flexible expansion of forming depth, high-precision transmission and convenient maintenance.

Description

Technical Field

[0001] This invention belongs to the field of additive manufacturing technology, and in particular relates to a multi-segment forming cylinder lifting platform for LPBF equipment. Background Technology

[0002] Currently, Chinese patent publication number CN202322132891.3A discloses a lifting system for a metal 3D printer, including a base, which is rectangular and made of stainless steel; a power unit mounted on the base; an optical axis connecting plate connected to the top of the power unit for connecting a 3D printing substrate and controlled by the power unit to perform lifting movements; four optical axes symmetrically passing through the optical axis connecting plate; and a lifting cavity shell fitted onto the top of the optical axis connecting plate. This discloses a prior art method that uses multiple whole plates side-joined to form a cylinder structure.

[0003] This type of technology, which uses multiple whole plates spliced ​​together to form a cylinder, has problems such as complex splicing structure, processing and assembly precision, which make it difficult to control the horizontal and vertical of the processing platform. The many splicing gaps also make it difficult to achieve a complete seal, increasing the complexity of the sealing and the probability of air leakage. It is difficult to find and repair leaks. Moreover, the splicing of whole plates increases the internal right angles, making it more difficult to meet the requirements of gas sealing and powder dynamic sealing of the molding substrate. For molding platforms with large size and depth, the integrated cylinder is too large to be realized, making it difficult to guarantee processing precision and control costs. Summary of the Invention

[0004] Therefore, in response to the above problems, this invention proposes a multi-segment forming cylinder lifting platform for LPBF equipment, which solves the technical problems of large-depth forming cylinders, which are difficult and costly to process in one piece; the complex structure of sheet metal splicing, with many seams leading to poor air tightness; and the many internal right angles leading to difficulty in dynamic sealing and easy powder leakage.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A multi-segment forming cylinder lifting platform for an LPBF (Limited Part Forming) device includes a support plate, a multi-segment forming cylinder assembly mounted on the support plate, a dynamic sealing component, a lifting drive assembly, and a detection and control unit. The multi-segment forming cylinder assembly is formed by stacking multiple segmented forming cylinders vertically. The multi-segment forming cylinder assembly forms a forming chamber for lifting the dynamic sealing component. The lifting drive assembly is installed below the multi-segment forming cylinder assembly and is used to drive the dynamic sealing component to move vertically within the forming chamber. The dynamic sealing component is located within the forming chamber and connected to the lifting drive assembly. The edge of the dynamic sealing component slides against the inner wall of the segmented forming cylinders. The detection and control unit includes a first grating ruler for detecting the height position of the dynamic sealing component and a servo driver. The lifting drive assembly includes an electric cylinder body located at the center of the support plate, a push rod disposed within the electric cylinder body, and guide column assemblies symmetrically distributed around the electric cylinder body.

[0006] Furthermore, a sealing groove is provided between two adjacent segmented forming cylinders, and a sealant for achieving an airtight seal is provided in the sealing groove. A positioning pin is provided between adjacent segmented forming cylinders.

[0007] Furthermore, the multiple segmented forming cylinders are of the same height, and the four corners of the inner wall of the segmented forming cylinder are all rounded.

[0008] Furthermore, a maintenance opening is provided on the side of the segmented forming cylinder at the bottom of the multi-segment forming cylinder assembly, and a powder cleaning port sealing plate is provided at the maintenance opening. The height of the maintenance opening is lower than the bottom height of the dynamic sealing assembly's movement stroke.

[0009] Furthermore, the dynamic sealing assembly includes a base plate connected to the guide post assembly and the electric cylinder body, a dynamic sealing middle plate disposed on the top surface of the base plate, and a mounting plate installed on the top surface of the dynamic sealing middle plate. The side of the dynamic sealing middle plate is provided with a dynamic sealing ring groove along the circumferential direction, and a high-temperature resistant sealing ring is installed in the dynamic sealing ring groove.

[0010] Furthermore, the number of guide post assemblies is at least four, which are evenly and symmetrically distributed around the electric cylinder body.

[0011] Furthermore, a telescopic dust cover is provided between the base plate and the support plate, and the telescopic dust cover is located on the outside of the guide post and the push rod.

[0012] Furthermore, each of the segmented forming cylinders is provided with a heating rod on its outer side, a temperature sensor on its outer side, and a photoelectric sensor for detecting powder leakage is provided at the powder cleaning port sealing plate position of the segmented forming cylinder.

[0013] Furthermore, the lifting drive assembly also includes four torque motors mounted on the bottom surface of the base plate. A nut slider is slidably mounted on the bottom surface of the dynamic sealing plate. The lead screws of the torque motors pass through the base plate and engage with the nut sliders. A piezoelectric ceramic fine-tuning mechanism is provided between the top surface of the nut slider and the dynamic sealing plate. The top surface of the piezoelectric ceramic fine-tuning mechanism has a hemispherical contact that contacts the bottom surface of the dynamic sealing plate. A second grating ruler is provided on the edge of the dynamic sealing plate. There is a plate gap between the dynamic sealing plate and the base plate. A stepped hole is provided at the corner of the dynamic sealing plate. A locking bolt for connecting the dynamic sealing plate and the base plate is provided at the stepped hole of the dynamic sealing plate. A spring is provided between the locking bolt and the stepped hole in the dynamic sealing plate.

[0014] By adopting the aforementioned technical solution, the beneficial effects of the present invention are: This multi-segment forming cylinder lifting platform for LPBF equipment is assembled by stacking multiple segmented forming cylinders vertically. This design not only solves the problems of high processing difficulty and manufacturing cost of large-depth integrated forming cylinders, but also makes it easier to control the internal surface quality, verticality, and dimensional tolerances of each cylinder segment with high precision. At the same time, it eliminates the traditional longitudinal splicing seams. Combined with the positioning pins on adjacent end faces and the sealant in the sealing groove, it not only achieves precise and smooth stepless assembly, but also creates a reliable horizontal air seal, ensuring a low-oxygen tight environment in the forming chamber of the LPBF equipment. Moreover, the forming depth can be flexibly expanded by increasing or decreasing the number of segmented forming cylinders. Addressing the technical challenge of achieving dynamic sealing due to the prevalence of right angles in the interior of existing segmented forming cylinders, this invention designs rounded corners on all four sides of the inner wall of the segmented forming cylinder. This design avoids the dead angles of traditional right angle dynamic sealing, ensuring that the gap between the dynamic sealing component and the inner wall of the segmented forming cylinder remains highly consistent during lifting and lowering. Uniform compression deformation prevents uneven friction caused by excessively narrow gaps on one side, effectively preventing jamming and swaying of the dynamic sealing component due to leverage forces. This improves the movement stability of the dynamic sealing component within the large-format multi-segment forming cylinder assembly, fundamentally cutting off the path of powder leakage and significantly extending the service life of the high-temperature resistant sealing ring.

[0015] Although the multi-segment forming cylinder assembly of this invention adopts high-precision splicing, when the dynamic sealing component sinks layer by layer in the multi-segment forming cylinder assembly and crosses the splicing gap of adjacent segment forming cylinders, it is still inevitable that instantaneous mechanical jamming and high-frequency vibration will occur due to the step change in the friction force of the sealing component. If segmented cylinders are used in traditional equipment, this vibration will cause inaccurate powder thickness of the cross-seam layer or even cause delamination of the printed part. This application utilizes the sensitivity of the second grating ruler and the microsecond-level response characteristics of piezoelectric ceramics. When the high-temperature resistant sealing ring passes through the splicing gap between the segment forming cylinders, once the second grating ruler captures the abnormal vertical vibration caused by the friction change, the piezoelectric ceramic fine adjustment mechanism instantly performs micro-extension and contraction in the same frequency and opposite direction under the cooperation of spring pre-tension. Through the extremely rapid physical deformation, the step mechanical impact force generated when crossing the gap is absorbed and canceled, which makes up for the inherent physical joint defects of the segmented cylinder body, so that the dynamic sealing component remains smooth when falling across segments, ensuring the consistency of powder layer thickness at the cross-seam interface.

[0016] Throughout the entire printing cycle, the instantaneous cutting friction of the powder-spreading squeegee and the enormous thermal stress warping generated by the instantaneous melting of the high-power laser can cause instantaneous high-frequency vibrations of tens of micrometers in the dynamic sealing components. Traditional motors, due to mechanical inertia and return clearance, are simply unable to react to such instantaneous interference, resulting in uneven powder spreading or squeegee jamming and collision. This application utilizes the microsecond-level high-frequency response characteristics of the piezoelectric ceramic fine-tuning mechanism to rapidly extend and retract at the instant the interference occurs, instantly absorbing and smoothing out all tiny vibrations, thus ensuring micrometer-level rigidity under extremely harsh processing environments. Attached Figure Description

[0017] Figure 1 This is a front view schematic diagram of the structure of the present invention.

[0018] Figure 2 This is a schematic diagram of the structure of the present invention.

[0019] Figure 3 This is a top view schematic diagram of the structure of the present invention.

[0020] Figure 4 This is a schematic cross-sectional view of the AA structure of the present invention.

[0021] Figure 5 This is a schematic diagram of the structure in the explosion state of the present invention.

[0022] Figure 6 This is a schematic diagram of the multi-segment molded cylinder assembly in an exploded state according to the present invention.

[0023] Figure 7 This is a schematic diagram of the dynamic sealing assembly in an exploded state according to the present invention.

[0024] Figure 8This is a front view schematic diagram of a partial structure of the multi-segment molding cylinder assembly, the moving component, and the output component of the present invention.

[0025] Figure 9 This is an enlarged schematic diagram of a partial structure of the dynamic sealing assembly of the present invention.

[0026] Numbering on the map: 1. Support plate; 2. Multi-segment molding cylinder assembly; 3. Lifting drive assembly; 4. Dynamic sealing assembly; 5. First grating ruler; 6. Piezoelectric ceramic fine-tuning mechanism; 601. Hemispherical contact; 7. Second grating ruler; 8. Heating rod; 801. Temperature sensor; 9. Photoelectric sensor; 200. Segmented molding cylinder; 201. Molding chamber; 202. Sealing groove; 203. Sealant; 204. Positioning pin; 205. Maintenance opening; 206. Powder cleaning port sealing plate; 301. Electric cylinder body; 302. Push rod; 303. Guide column assembly; 401. Base plate; 402. Dynamic seal middle plate; 403. Mounting plate; 404. Dynamic seal ring groove; 405. High temperature resistant seal ring; 406. Telescopic dust cover; 407. Torque motor; 408. Nut slider; 409. Stepped hole; 410. Locking bolt; 411. Spring; 400. Plate gap. Detailed Implementation

[0027] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments.

[0028] refer to Figures 1 to 9 This embodiment provides a multi-segment forming cylinder lifting platform for LPBF equipment, including a support plate 1, a multi-segment forming cylinder assembly 2 disposed on the support plate 1, a lifting drive assembly 3, a dynamic sealing assembly 4, and a detection and control unit.

[0029] The multi-segment molding cylinder assembly 2 is assembled by stacking multiple segmented molding cylinders 200 vertically, and the multi-segment molding cylinder assembly 2 forms a molding chamber 201 for the dynamic sealing assembly 4 to move up and down.

[0030] The lifting drive assembly 3 is installed below the multi-segment molding cylinder assembly 2 and is used to drive the dynamic sealing assembly 4 to move vertically within the molding chamber 201.

[0031] The dynamic sealing assembly 4 is located inside the molding chamber 201 and is connected to the lifting drive assembly 3. The edge of the dynamic sealing assembly 4 slides in cooperation with the inner wall of the segmented molding cylinder 200.

[0032] The detection and control unit includes a first grating ruler 5 for detecting the height position of the dynamic sealing assembly 4 and a servo driver (not shown in the figure). The lifting drive assembly 3 includes an electric cylinder body 301 located at the center of the support plate 1, a push rod 302 disposed in the electric cylinder body 301, and a guide column assembly 303 symmetrically distributed around the electric cylinder body 301.

[0033] In use, the servo driver drives the push rod 302 inside the electric cylinder body 301 to move via the built-in electric cylinder reducer at the bottom. The push rod 302 then drives the dynamic sealing assembly 4 to move within the molding chamber 201 formed by the multi-segment molding cylinder assembly 2. The multi-segment molding cylinder assembly 2, composed of segmented molding cylinders 200 stacked from top to bottom, can ensure that each segmented molding cylinder 200 has the same height. The height of each segmented molding cylinder 200 can be adjusted according to actual usage. The height of each segmented molding cylinder 200 is designed to be approximately 200mm, which can be adjusted according to the processing capabilities. The force adjustment ensures that the height value is less than the maximum height dimension that the manufacturing process can guarantee for internal surface quality, verticality, and accuracy. The number of segmented forming cylinders 200 is determined according to the forming depth required by the equipment. If a deeper forming cylinder size is required, simply increase the number of segmented forming cylinders 200. The upper and lower surfaces and internal planes of the segmented forming cylinders 200 can be precision machined to ensure dimensional tolerances and accuracy requirements. This design ensures verticality and machining accuracy, avoiding the disadvantages of existing one-piece deep forming cylinders, such as high machining difficulty and numerous seams and poor airtightness in plate splicing.

[0034] A sealing groove 202 is provided between the upper and lower mating surfaces of two adjacent segmented forming cylinders 200. The sealing groove 202 is provided with sealant 203 for achieving airtightness. The segmented forming cylinders 200 are sealed with sealant 203 to seal the splicing gap. This sealing method is quick and reliable. A positioning pin 204 is provided between adjacent segmented forming cylinders 200 to facilitate positioning and assembly and ensure accurate and smooth splicing of the upper and lower inner walls.

[0035] The inner wall of the segmented forming cylinder 200 has rounded corners, which facilitates a tight fit between the dynamic sealing component 4 and the forming chamber 201 inside the segmented forming cylinder 200. Due to the high processing and assembly precision of the segmented forming cylinder 200, the gap between the inner wall of the segmented forming cylinder 200 and the dynamic sealing component 4 is highly consistent. Compared with the existing internal right-angle structure, this rounded corner structure simplifies the dynamic sealing difficulty of the formed substrate powder and avoids the increasingly serious problems of powder and air leakage caused by dead angles in the sealing mechanism and wear and aging of the sealing components. At the same time, it prevents the uneven friction caused by excessively narrow gaps on one side during movement. Uneven friction can cause the dynamic sealing component 4 to wobble due to large leverage force, affecting the stability of the dynamic sealing component 4. The structural design of the segmented forming cylinder 200 ensures the stability of the dynamic sealing component 4.

[0036] A maintenance opening 205 is provided on the side of the segmented forming cylinder 200 located at the bottom of the multi-segment forming cylinder assembly 2. A powder cleaning port sealing plate 206 is provided at the maintenance opening 205. The height of the maintenance opening 205 is lower than the bottom height of the movement stroke of the dynamic sealing assembly 4.

[0037] The maintenance opening 205 is used to observe the powder leakage inside the segmented forming cylinder 200 after long-term operation and to facilitate the insertion of tools for powder suction and cleaning maintenance. When sealing is required, the powder cleaning port sealing plate 206 can be used to seal it.

[0038] The dynamic sealing assembly 4 includes a base plate 401 connected to the guide post assembly 303 and the electric cylinder body 301, a dynamic sealing middle plate 402 disposed on the top surface of the base plate 401, and a mounting plate 403 installed on the top surface of the dynamic sealing middle plate 402. The side of the dynamic sealing middle plate 402 is provided with a plurality of dynamic sealing ring grooves 404 along the circumferential direction, and a high-temperature resistant sealing ring 405 is installed in the dynamic sealing ring grooves 404.

[0039] Since the four corners of the inner wall of the segmented forming cylinder 200 are all rounded, the gaps between the bottom plate 401, the dynamic sealing middle plate 402 and the mounting plate 403 and the inner wall of the segmented forming cylinder 200 are highly consistent. Furthermore, the high-temperature resistant sealing ring 405 on the outer side of the dynamic sealing middle plate 402 further eliminates the gaps with the inner wall of the segmented forming cylinder 200, which can further improve the airtightness.

[0040] The dynamic sealing ring groove 404 can be provided with 1 to 3 (not shown). The illustration shows 1 dynamic sealing ring groove 404, which helps to extend the replacement time of the high-temperature resistant sealing ring 405 and prevent powder from falling to the maximum extent. The inner wall of the multi-segment molding cylinder assembly 2 is smooth and has good precision, with no extra seams or right-angle dead corners. The structure of the dynamic sealing ring groove 404 of the dynamic sealing component 4 is sufficient to meet the dynamic sealing requirements. The compression ratio of the high-temperature resistant sealing ring 405 meets the dynamic sealing requirements, avoiding the lack of secondary protection due to powder leakage, which could lead to powder directly contaminating the transmission structure and electrical components and affecting the stability of the equipment.

[0041] The number of guide post assemblies 303 is at least 4, which are evenly and symmetrically distributed around the electric cylinder body 301. The electric cylinder body 301 is located at the center of the segmented forming cylinder 200. The guide post assemblies 303 are symmetrically distributed around the periphery of the electric cylinder body 301 to ensure the stability of the dynamic sealing assembly 4 during the movement of the segmented forming cylinder 200, the synchronicity of the movement of each position, and the levelness of the plane. The number of guide post assemblies 303 can be 6, 8, or other numbers to ensure the stability of the dynamic sealing assembly 4 with a larger area.

[0042] A telescopic dust cover 406 is provided between the drive base plate 401 and the support plate 1. The telescopic dust cover 406 is located on the outside of the guide post and push rod 302 inside the guide post assembly 303. It serves as a secondary seal to prevent dust contamination of the main rod and guide rod assembly of the electric cylinder body 301 after a small amount of powder falls from the inner wall of the segmented forming cylinder 200 during long-term use, thus ensuring the long-term stability and transmission accuracy of the system.

[0043] The first grating ruler 5 is used to accurately detect the current height position of the dynamic sealing component 4. The signal of the first grating ruler 5 is directly connected to the servo driver with built-in closed-loop control function, thereby forming a more efficient and stable full closed-loop control strategy. The closed-loop control process is as follows: the first grating ruler 5 is connected to one of the guide pillars of the guide pillar assembly 303. The first grating ruler 5 detects the actual position of the dynamic sealing component 4 in real time and feeds the signal directly back to the servo driver. The comparator inside the servo driver compares the actual position with the target position and quickly adjusts the motor speed and torque through the PID algorithm. This control loop does not go through the host computer, eliminating communication delay and host computer processing jitter, and achieving extremely high response speed and positioning accuracy.

[0044] This closed-loop chain is simple and has an extremely fast response speed. It can achieve rapid positioning and suppress overshoot and jitter, further enhancing the stability of motion. The mature closed-loop control function inside the servo driver also solves the problems of complex upper computer programming and difficult debugging, simplifying the upper computer program and making the system more streamlined, efficient and stable.

[0045] Each segmented forming cylinder 200 is provided with a heating rod 8 on its outer side and a temperature sensor 801 on its outer side. The segmented forming cylinder 200 is provided with a photoelectric sensor 9 for detecting powder leakage at the powder cleaning port sealing plate 206. The heating rod 8, temperature sensor 801 and photoelectric sensor 9 can be connected to an external control board (not shown in the figure). The bottom segmented forming cylinder 200 is equipped with a photoelectric sensor 9 that can be used to detect powder leakage in time and remind personnel to check and replace the high temperature resistant sealing ring 405, thus forming a closed loop of sealing function.

[0046] Temperature sensors 801 in each segmented forming cylinder 200 can detect the temperature of each segmented forming cylinder 200. If the temperature of one segmented forming cylinder 200 is detected to be lower than the set value, the external control board will individually control the heating rod 8 on the outside of one segmented forming cylinder 200 to heat it. This solves the problems of poor temperature control uniformity and inability to control the temperature of segments according to the printing height in existing segmented forming cylinders 200. The multi-segment splicing design facilitates the installation, maintenance, and replacement of temperature sensors 801. If a segment temperature sensor 801 is damaged, it is not necessary to disassemble the entire segmented forming cylinder 200; only the corresponding segmented forming cylinder 200 needs to be replaced, further improving maintenance convenience. At the same time, it can be used in conjunction with sealant 203, which also has a certain heat insulation property, to prevent the temperature of adjacent segmented forming cylinders 200 from affecting each other, prevent deformation of the segmented forming cylinders 200 caused by high temperature, and indirectly improve dynamic sealing performance.

[0047] Each segmented forming cylinder 200 is independently equipped with a heating rod 8 and a temperature sensor 801, enabling precise stepped temperature control. During printing, the heating state of the segmented forming cylinder 200 can be controlled according to the current printing height, heating only the segmented forming cylinder 200 currently being printed and the segmented forming cylinder 200 below it. Compared with the traditional overall heating method, this method is more energy-efficient, reduces ineffective heating areas, heats up faster, and significantly improves temperature control accuracy. During LPBF printing, the top powder bed is directly exposed to laser irradiation, where laser energy is concentrated and the temperature is high. The powder bed temperature decreases with the forming depth. This stepped temperature control can specifically adapt to the temperature requirements of powder beds at different heights, effectively ensuring the overall temperature uniformity of the powder and avoiding defects such as uneven stress, cracking, and delamination inside the printed parts due to uneven temperature phenomena such as overheating at the top and undercooling at the bottom.

[0048] The lifting drive assembly 3 also includes four torque motors 407 disposed on the bottom surface of the base plate 401. A nut slider 408 is slidably disposed on the bottom surface of the dynamic sealing plate 402. The lead screws of the torque motors 407 pass through the base plate 401 and engage with the nut slider 408. A piezoelectric ceramic fine-tuning mechanism 6 is disposed between the top surface of the nut slider 408 and the dynamic sealing plate 402. The top surface of the piezoelectric ceramic fine-tuning mechanism 6 is provided with a hemispherical contact 601 that contacts the bottom surface of the dynamic sealing plate 402. A second grating ruler 7 is disposed on the edge of the dynamic sealing plate 402. There is a plate gap 400 between plate 402 and base plate 401. The corner of the dynamic sealing plate 402 is provided with a stepped hole 409. The stepped hole 409 of the dynamic sealing plate 402 is provided with a locking bolt 410 for connecting the dynamic sealing plate 402 and the base plate 401. A spring 411 is provided between the locking bolt 410 and the stepped hole 409 in the dynamic sealing plate 402. Affected by the spring 411 and the weight of the dynamic sealing plate 402, the bottom surface of the dynamic sealing plate 402 will remain in contact with the hemispherical contact 601 on the top surface of the piezoelectric ceramic fine adjustment mechanism 6.

[0049] Since each of the four corners of the forming dynamic sealing plate 402 is independently equipped with a second grating ruler 7, a torque motor 407, and a piezoelectric ceramic fine-tuning mechanism 6, the external control board can detect any tilt posture of the dynamic sealing assembly 4 in real time. When the printed part is in an eccentric position of the dynamic sealing assembly 4, such as the solid entity on the left being heavier and the dot matrix support on the right, resulting in uneven force and unilateral sinking and displacement, the second grating ruler 7 at the four corners transmits the height data acquired in real time to the external control board. The external control board calculates the tilt vector difference of the plane using a spatial matrix algorithm and controls the torque motor 407 and the piezoelectric ceramic fine-tuning mechanism 6 at the four corners.

[0050] For example, when it is detected that the left side of the dynamic seal assembly 4 has sunk by 1 mm due to heavy load, the control center only commands the left torque motor 407 to start, driving the built-in lead screw to rotate, causing the corresponding nut slider 408 on the left to move upward. The nut slider 408 lifts the left side of the dynamic seal plate 402 by 1 mm through the piezoelectric ceramic fine adjustment mechanism 6 on the top surface and the hemispherical contact 601 on the top. At this time, the right torque motor 407 and the piezoelectric ceramic fine adjustment mechanism 6 remain self-locking and stationary. After the left side of the dynamic seal plate 402 is corrected to the correct position, the left torque motor 407 stops. The self-locking force of the thread of the torque motor 407 with the built-in lead screw supports the gravity load on the left side of the dynamic seal plate 402, thereby completing the large-stroke unilateral anti-eccentric load and coarse leveling.

[0051] As the number of printed layers increases, the total weight of the laid metal powder and the molded entity continues to accumulate. When the dynamic sealing plate 402 slowly sinks in an overall or eccentric elastic manner, the external control board continuously monitors it through the second grating ruler 7. Once the average displacement deviation exceeds the set threshold of the torque motor 407, the torque motors 407 at the four corners will rotate synchronously or differentially at low speed, driving the nut slider 408 to slowly push upward for compensation, always providing rigid support for the dynamic sealing plate 402.

[0052] Each time the powder-spreading scraper passes over the powder bed at high speed, the scraping friction of the scraper will bring instantaneous lateral and downward cutting forces to the dynamic sealing plate 402. Or, during the instant of high-power laser melting, the great thermal stress will cause local instantaneous warping. These disturbances generate extremely fast height difference jitter at the tens of micrometer level. Due to mechanical inertia, the torque motor 407 cannot respond instantly. At this time, the piezoelectric ceramic fine adjustment mechanism 6 located above the nut slider 408 compensates. When the second grating ruler 7 detects the microsecond-level high-frequency micro-drop difference, the piezoelectric ceramic fine adjustment mechanism 6 is instantly energized and deformed. Utilizing its high-frequency response characteristics, under the tight contact of the spring 411 at the locking bolt 410 position, the hemispherical contact 601 pushes or shrinks the dynamic sealing plate 402 extremely quickly. Through the dynamic synergy of the coarse adjustment of the torque motor 407 and the piezoelectric ceramic fine adjustment mechanism 6 to fill the micrometer-level transient error, the scraper collision jitter and gravity off-center load effects are avoided, so that the dynamic sealing plate 402 remains in a horizontal state throughout the entire molding process.

[0053] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0054] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0055] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0056] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0057] Although the invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that various changes in form and detail may be made to the invention without departing from the spirit and scope of the invention as defined in the appended claims, all of which shall be within the scope of protection of the invention.

Claims

1. A multi-segment forming cylinder lifting platform for LPBF equipment, characterized in that, It includes a support plate (1), a multi-segment molding cylinder assembly (2) disposed on the support plate (1), a dynamic sealing assembly (4), a lifting drive assembly (3), and a detection and control unit; The multi-segment molding cylinder assembly (2) is assembled by stacking multiple segmented molding cylinders (200) vertically. The multi-segment molding cylinder assembly (2) forms a molding chamber (201) for the dynamic sealing assembly (4) to rise and fall. The lifting drive assembly (3) is installed below the multi-section molding cylinder assembly (2) and is used to drive the dynamic sealing assembly (4) to move vertically in the molding chamber (201); The dynamic sealing assembly (4) is located in the molding chamber (201) and connected to the lifting drive assembly (3). The edge of the dynamic sealing assembly (4) slides in cooperation with the inner wall of the segmented molding cylinder (200). The detection and control unit includes a first grating ruler (5) for detecting the height position of the dynamic sealing assembly (4) and a servo driver. The lifting drive assembly (3) includes an electric cylinder body (301) located at the center of the support plate (1), a push rod (302) disposed in the electric cylinder body (301), and a guide column assembly (303) symmetrically distributed around the electric cylinder body (301).

2. The multi-segment forming cylinder lifting platform for LPBF equipment according to claim 1, characterized in that: A sealing groove (202) is provided between two adjacent segmented forming cylinders (200), and a sealant (203) for achieving an airtight seal is provided in the sealing groove (202). A positioning pin (204) is provided between adjacent segmented forming cylinders (200).

3. A multi-segment forming cylinder lifting platform for LPBF equipment according to claim 1, characterized in that: All the segmented forming cylinders (200) have the same height, and the four corners of the inner wall of the segmented forming cylinder (200) are rounded.

4. A multi-segment forming cylinder lifting platform for LPBF equipment according to claim 3, characterized in that: A maintenance opening (205) is provided on the side of the segmented forming cylinder (200) located at the bottom of the multi-segment forming cylinder assembly (2). A powder cleaning port sealing plate (206) is provided at the maintenance opening (205). The height of the maintenance opening (205) is lower than the bottom height of the dynamic sealing assembly (4) during its movement stroke.

5. A multi-segment forming cylinder lifting platform for LPBF equipment according to claim 4, characterized in that: The dynamic sealing assembly (4) includes a base plate (401) connected to the guide post assembly (303) and the electric cylinder body (301), a dynamic sealing middle plate (402) disposed on the top surface of the base plate (401), and a mounting plate (403) installed on the top surface of the dynamic sealing middle plate (402). The side of the dynamic sealing middle plate (402) is provided with a dynamic sealing ring groove (404) along the circumferential direction, and a high-temperature resistant sealing ring (405) is installed in the dynamic sealing ring groove (404).

6. A multi-segment forming cylinder lifting platform for LPBF equipment according to claim 5, characterized in that: The number of guide post assemblies (303) is at least 4, which are evenly and symmetrically distributed around the electric cylinder body (301).

7. A multi-segment forming cylinder lifting platform for LPBF equipment according to claim 6, characterized in that: A telescopic dust cover (406) is provided between the base plate (401) and the support plate (1), and the telescopic dust cover (406) is located on the outside of the guide post and the push rod (302).

8. A multi-segment forming cylinder lifting platform for LPBF equipment according to claim 1, characterized in that: Each segmented forming cylinder (200) is provided with a heating rod (8) on its outer side, and a temperature sensor (801) is provided on its outer side. The segmented forming cylinder (200) is provided with a photoelectric sensor (9) for detecting powder leakage at the powder cleaning port sealing plate (206).

9. A multi-segment forming cylinder lifting platform for LPBF equipment according to claim 5, characterized in that: The lifting drive assembly (3) also includes four torque motors (407) disposed on the bottom surface of the base plate (401). A nut slider (408) is slidably disposed on the bottom surface of the dynamic sealing plate (402). The lead screw of the torque motor (407) passes through the base plate (401) and engages with the nut slider (408). A piezoelectric ceramic fine adjustment mechanism (6) is disposed between the top surface of the nut slider (408) and the dynamic sealing plate (402). The top surface of the piezoelectric ceramic fine adjustment mechanism (6) is provided with a hemispherical contact (601) that contacts the bottom surface of the dynamic sealing plate (402). The edge of the dynamic sealing plate (402) is provided with a second grating ruler (7). There is a plate gap (400) between the dynamic sealing plate (402) and the bottom plate (401). The corner of the dynamic sealing plate (402) is provided with a stepped hole (409). The stepped hole (409) of the dynamic sealing plate (402) is provided with a locking bolt (410) for connecting the dynamic sealing plate (402) and the bottom plate (401). A spring (411) is provided between the locking bolt (410) and the stepped hole (409) in the dynamic sealing plate (402).

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