Metal powder sintering device

Abstract

The invention discloses a metal powder sintering device which comprises a forming chamber, and a first air inlet communicated with a vacuum pump system is formed in one side of the forming chamber; the forming cylinder is arranged at the bottom in the forming chamber, and a lifting table is arranged in the forming cylinder in a lifting mode; one side of the forming cylinder is provided with the powder flattening mechanism used for flattening metal powder on the lifting table; and the selective laser sintering system is arranged above the forming cylinder, and the computer control system is arranged on the outer side of the forming chamber and used for controlling the selective laser sintering system to sinter the metal powder on the lifting table.

Description

Technical Field

[0001] This invention relates to the field of powder metallurgy, and more specifically, to a metal powder sintering apparatus. Background Technology

[0002] Metal powder sintering technology, with its advantages of producing complex structural parts, high material utilization, and stable performance after molding, is widely used in high-end manufacturing fields such as aerospace, automotive manufacturing, and precision machinery. Existing metal powder sintering equipment mostly adopts a two-step process of "pressing and molding + high-temperature sintering." First, metal powder is pressed into a pre-set shape using a mold, and then the blank is sent to a high-temperature sintering furnace for sintering and solidification to ensure the structural strength of the parts.

[0003] However, the above process has obvious drawbacks: First, pressing and molding rely on molds. For complex and irregularly shaped parts, the design and manufacturing of molds are difficult and costly, and the molds have poor versatility, making it difficult to meet the production needs of small batches and multiple varieties. Second, the density of metal powder is easily unevenly distributed during the pressing process, which leads to problems such as deformation, cracking, and insufficient strength of the parts after sintering, thus limiting the product qualification rate. Third, high-temperature sintering is a whole-body heating mode, which consumes a lot of energy, and the surface of the parts is easily oxidized, affecting the product precision and performance.

[0004] Therefore, providing a metal powder sintering apparatus that does not require molds, has high forming accuracy, and can adapt to the preparation of complex parts is a problem that this invention urgently needs to solve. Summary of the Invention

[0005] To address the aforementioned technical problems, the purpose of this invention is to overcome the significant shortcomings of existing processes: First, pressing molding relies on molds, which are difficult and costly to design and manufacture for complex and irregularly shaped parts. Furthermore, the molds have poor versatility, making them unsuitable for small-batch, multi-variety production. Second, uneven distribution of metal powder density during pressing leads to deformation, cracking, and insufficient strength in sintered parts, limiting product yield. Third, high-temperature sintering involves overall heating, resulting in high energy consumption and easy oxidation of the part surface, affecting product precision and performance. Therefore, this invention provides a metal powder sintering apparatus that requires no molds, offers high forming precision, and can adapt to the preparation of complex parts.

[0006] To achieve the above objectives, the present invention provides a metal powder sintering apparatus, comprising: a forming chamber, wherein a first air inlet connected to a vacuum pump system is provided on one side of the forming chamber; a forming cylinder, wherein a forming cylinder is provided at the bottom of the forming chamber, and a lifting platform is provided inside the forming cylinder; a powder leveling mechanism, wherein a powder leveling mechanism for leveling metal powder on the lifting platform is provided on one side of the forming cylinder; a laser selective sintering system and a computer control system, wherein the laser selective sintering system is located above the forming cylinder, and the computer control system is located outside the forming chamber for controlling the laser selective sintering system to sinter the metal powder on the lifting platform.

[0007] Preferably, the powder leveling mechanism includes: a movable cover and a first driving assembly, the movable cover being reciprocally movable against the bottom wall of the molding chamber via the first driving assembly; a first rigid pipe, one end of the first rigid pipe communicating with the interior of the movable cover, and the other end extending horizontally out of the molding chamber; a telescopic pipe and a second rigid pipe, the second rigid pipe and the first rigid pipe being coaxially suspended on one side of the molding chamber, the telescopic pipe being coaxially disposed between the first rigid pipe and the second rigid pipe, with one end communicating with the first rigid pipe and the other end communicating with the second rigid pipe; a third connecting pipe, a powder mixing device being disposed above the second rigid pipe, one end of the third connecting pipe communicating with the outlet of the powder mixing device and the other end communicating with the second rigid pipe; and a metal powder conveying assembly disposed inside the second rigid pipe for conveying metal powder into the movable cover.

[0008] Preferably, the first driving component includes a first linear driver and a first guide rod. The movable cover is reciprocated toward the molding cylinder by the first linear driver, and a plurality of first guide rods are provided horizontally through the molding chamber on one side of the cover along its moving direction.

[0009] Preferably, the metal powder conveying assembly includes: a first rotary drive motor and a conveying screw, wherein the conveying screw is rotatably disposed inside the second rigid pipe via the first rotary drive motor.

[0010] Preferably, a guide roller is coaxially arranged at the end of the conveying screw away from the first rotary drive motor, and a guide frame adapted to the guide roller is arranged inside the first rigid pipe.

[0011] Preferably, the device further includes a second drive assembly for driving the lifting platform to rise and fall; wherein the second drive assembly includes: a rotating ring gear, a drive screw is provided vertically extending from the bottom of the lifting platform to form the cylinder, and second guide rods are provided on opposite sides of the lifting platform to extend from the forming cylinder, the rotating ring gear is rotatably provided at the bottom of the forming cylinder, and the rotating ring gear is coaxially threadedly assembled with the drive screw; a drive gear and a second rotary drive motor, the drive gear being rotatably disposed on one side of the rotating ring gear through the second rotary drive motor and meshing with the rotating ring gear.

[0012] Preferably, the molding cylinder is provided with a separation plate inside to isolate the metal powder from its bottom, and the drive screw is an incomplete screw with its threaded portion located below the separation plate.

[0013] Preferably, the laser selective sintering system includes: a laser, and a laser emitting chamber is horizontally arranged above the forming chamber, with the laser emitting chamber located at the end away from the forming cylinder for emitting a laser beam; a beam expander, which is arranged on one side of the laser for adjusting the diameter and divergence angle of the laser beam; a scanning galvanometer, which is arranged directly above the forming cylinder for controlling the scanning path of the laser beam; and a focusing lens, which is horizontally arranged below the scanning galvanometer to focus the laser beam into a uniform spot on the surface of the lifting platform.

[0014] Preferably, the device further includes a second linear actuator and a sealing door. The molding chamber is provided with an opening adapted to the sealing door on the side near the molding cylinder. The sealing door is provided at the opening in a way that allows it to be raised and lowered via the second linear actuator.

[0015] According to the above technical solution, the beneficial effects of this invention compared with the prior art are as follows: A first air inlet connected to a vacuum pump system is provided on one side of the forming chamber, which can quickly extract air from the forming chamber and create a stable vacuum sintering environment. This design effectively avoids oxidation reactions of metal powder during laser high-temperature sintering, reduces oxide inclusion defects inside the sintered parts, and significantly improves the density, mechanical strength, and corrosion resistance of the sintered parts. The liftable lifting platform and powder leveling mechanism inside the forming cylinder are the core execution components of selective laser sintering. The lifting stroke of the lifting platform can precisely match the single-layer sintering thickness. Through the cyclic action of "powder spreading - sintering - lifting platform descent," the layer-by-layer accumulation forming of complex structure metal parts is achieved, ensuring the dimensional and shape accuracy of the formed parts. In addition, the liftable design of the lifting platform facilitates the removal of the formed parts from the forming cylinder after sintering, simplifying part removal. The process is streamlined and improved for ease of operation. The collaborative design of the laser selective sintering system and the computer control system enables full automation and intelligence of the sintering process. The computer control system can precisely control the scanning path and energy parameters of the laser beam based on the preset three-dimensional part model, enabling the manufacturing of parts with complex cavities and hollow structures that are difficult to form using traditional processing techniques, thus expanding the design freedom of metal parts. Furthermore, the computer control system is located outside the molding chamber, which not only facilitates parameter adjustment, real-time monitoring, and fault warning for operators, but also avoids the corrosion of the control system by the high temperature and vacuum environment inside the molding chamber, extending the service life of the equipment and improving operational reliability.

[0016] Other features and advantages of the present invention will be described in detail in the following detailed description section; and all parts not covered in the present invention are the same as or can be implemented using the prior art. Attached Figure Description

[0017] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a perspective view of a metal powder sintering apparatus provided in a preferred embodiment of the present invention; Figure 2 This is a planar sectional view of a metal powder sintering apparatus provided in a preferred embodiment of the present invention; Figure 3 This is a partial three-dimensional view of a metal powder sintering apparatus provided in a preferred embodiment of the present invention. Figure 1 ; Figure 4 This is a partial planar cross-sectional view of a metal powder sintering apparatus provided in a preferred embodiment of the present invention; Figure 5This is a partial three-dimensional view of a metal powder sintering apparatus provided in a preferred embodiment of the present invention. Figure 2 .

[0018] Explanation of reference numerals in the attached drawings: 1. Molding chamber; 11. First air inlet; 2. Molding cylinder; 21. Lifting platform; 211. Drive screw; 212. Second guide rod; 22. Isolation plate; 3. Powder leveling mechanism; 31. Moving cover; 32. First drive assembly; 321. First linear actuator; 322. First guide rod; 33. First rigid pipe; 331. Guide frame; 34. Telescopic pipe; 35. Second rigid pipe; 36. Third connecting pipe; 37. Metal powder conveying assembly; 371. First rotary drive motor; 372. Conveying screw; 3721. Guide roller; 4. Laser selective sintering system; 41. Laser; 42. Beam expander; 43. Scanning galvanometer; 44. Focusing lens; 5. Second drive assembly; 51. Rotating ring gear; 52. Drive gear; 53. Second rotary drive motor; 6. Laser emission chamber; 7. Second linear actuator; 8. Sealed door. Detailed Implementation

[0019] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0020] In the description of the embodiments of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationships commonly used when the product is in use. These are merely for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third," etc., are only used for distinguishing descriptions and should not be construed as indicating or implying relative importance. Additionally, the terms "horizontal," "vertical," and "suspended," etc., do not indicate that the component is required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0021] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" 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 the present invention according to the specific circumstances.

[0022] To further understand the features, technical means, and specific objectives and functions achieved by the present invention, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

[0023] Reference Figure 1 and Figure 2 A metal powder sintering apparatus includes: a forming chamber 1, with a first air inlet 11 connected to a vacuum pump system on one side; a forming cylinder 2, with a forming cylinder 2 located at the bottom of the forming chamber 1, and a lifting platform 21 vertically mounted inside the forming cylinder 2; a powder leveling mechanism 3, with a powder leveling mechanism 3 located on one side of the forming cylinder 2 for leveling metal powder on the lifting platform 21; a laser selective sintering system 4; and a computer control system, with the laser selective sintering system 4 located above the forming cylinder 2 and the computer control system located outside the forming chamber 1 for controlling the laser selective sintering system 4 to sinter the metal powder on the lifting platform 21.

[0024] The forming chamber 1 of this application has a first air inlet 11 connected to the vacuum pump system on one side, which can quickly extract air from the forming chamber 1 and create a stable vacuum sintering environment. This design can effectively avoid oxidation reaction of metal powder during laser high-temperature sintering, reduce oxide inclusion defects inside the sintered part, and significantly improve the density, mechanical strength, and corrosion resistance of the sintered part. The liftable lifting platform 21 and powder leveling mechanism 3 in the forming cylinder 2 are the core execution components of selective laser sintering. The lifting stroke of the lifting platform 21 can accurately match the single-layer sintering thickness. Through the cyclic action of "powder spreading-sintering-lifting platform 21 descending", the layer-by-layer accumulation forming of complex structure metal parts is realized, ensuring the dimensional and shape accuracy of the formed part. In addition, the liftable design of the lifting platform 21 facilitates the removal of the formed part from the forming cylinder 2 after sintering, simplifying the process. The process of picking up parts has been streamlined, improving operational convenience. The collaborative design of the laser selective sintering system 4 and the computer control system has realized the full automation and intelligence of the sintering process: the computer control system can accurately control the scanning path and energy parameters of the laser beam according to the preset three-dimensional part model, realizing the manufacturing of parts that are difficult to form by traditional processing technology, such as complex cavities and hollow structures, and expanding the design freedom of metal parts. Moreover, the computer control system is located outside the forming chamber 1, which not only facilitates the operator to adjust parameters, monitor in real time and provide fault warnings, but also avoids the corrosion of the high temperature and vacuum environment inside the forming chamber 1 on the control system, extending the service life of the equipment and improving operational reliability.

[0025] Reference Figure 2 The powder leveling mechanism 3 includes: a movable cover 31 and a first driving component 32, wherein the movable cover 31 is reciprocally moved against the bottom wall of the molding chamber 1 via the first driving component 32; a first rigid pipe 33, one end of which is connected to the interior of the movable cover 31, and the other end of which extends horizontally out of the molding chamber 1; a telescopic pipe 34 and a second rigid pipe 35, wherein the second rigid pipe 35 and the first rigid pipe 33 are coaxially suspended on one side of the molding chamber 1, and the telescopic pipe 34 is coaxially arranged between the first rigid pipe 33 and the second rigid pipe 35, with one end connected to the first rigid pipe 33 and the other end connected to the second rigid pipe 35; a third connecting pipe 36, wherein a powder mixing device is arranged above the second rigid pipe 35, one end of which is connected to the outlet of the powder mixing device and the other end of which is connected to the second rigid pipe 35; and a metal powder conveying component 37, which is arranged inside the second rigid pipe 35 to convey metal powder into the movable cover 31.

[0026] In this application, the first rigid pipe 33 is slidably connected to the molding chamber 1 by a sliding mechanical seal to ensure the sealing of the molding chamber 1; the telescopic pipe 34 is made of corrugated pipe, which can adaptively extend and retract with the reciprocating movement of the moving cover 31. The moving cover 31 moves back and forth to spread the metal powder inside it evenly on the molding cylinder 2 and the lifting platform 21, so there is no need to worry about the problem of needing to open the molding chamber 1 to add more metal powder after the metal powder inside the molding cylinder 2 is used up.

[0027] Reference Figure 3 The first drive assembly 32 includes a first linear driver 321 and a first guide rod 322. The movable cover 31 can be reciprocated toward the molding cylinder 2 by the first linear driver 321, and a plurality of first guide rods 322 are provided horizontally through the molding chamber 1 on one side of the cover along its moving direction.

[0028] The first guide rod 322 of this application is slidably connected to the molding chamber 1 by a sliding mechanical seal to ensure the sealing of the molding chamber 1; the several first guide rods 322 arranged along the moving direction can form a multi-support constraint on the movement trajectory of the moving cover 31, effectively limiting the deflection, tilting and other posture deviations that occur during the reciprocating movement of the moving cover 31, and ensuring that the moving cover 31 always moves parallel to the bottom wall of the molding chamber 1.

[0029] Reference Figure 4 The metal powder conveying assembly 37 includes a first rotary drive motor 371 and a conveying screw 372. The conveying screw 372 is rotatably disposed inside the second rigid pipe 35 via the first rotary drive motor 371.

[0030] During the rotation of the screw blades in this application, the screw can generate a dual action of axial pushing force and radial stirring force on the metal powder: the axial force pushes the powder to be conveyed in the direction of the moving hood 31, and the radial force can break up the agglomerated particles of the powder caused by storage or transportation, effectively avoiding problems such as powder bridging and blockage in the pipeline.

[0031] Reference Figure 4 The conveying screw 372 is coaxially provided with a guide roller 3721 at the end away from the first rotary drive motor 371, and a guide frame 331 adapted to the guide roller 3721 is provided inside the first rigid pipe 33.

[0032] The guide roller 3721 of this application is slidably and rotatably mounted on the guide frame 331. The guide roller 3721 has both sliding and rotating functions: the rotational characteristics are synchronized with the rotational movement of the conveying screw 372, reducing running resistance and energy loss; the sliding characteristics can adapt to the reciprocating movement of the first rigid pipe 33 with the moving cover 31.

[0033] Reference Figure 4 and Figure 5 The device further includes a second drive assembly 5 for driving the lifting platform 21 to rise and fall; wherein, the second drive assembly 5 includes: a rotating ring gear 51, a drive screw 211 is provided on the bottom of the lifting platform 21 vertically extending from the forming cylinder 2, and second guide rods 212 are provided on the opposite sides of the forming cylinder 2 respectively, the rotating ring gear 51 is rotatably provided on the bottom of the forming cylinder 2, and the rotating ring gear 51 is coaxially threadedly assembled with the drive screw 211; a drive gear 52 and a second rotary drive motor 53, the drive gear 52 is rotatably provided on one side of the rotating ring gear 51 through the second rotary drive motor 53, and meshes with the rotating ring gear 51.

[0034] This application uses a second rotary drive motor 53 to drive a drive gear 52. The drive gear 52 meshes with a rotating ring gear 51 for transmission. The lifting platform 21 is then lifted by the coaxial thread assembly of the rotating ring gear 51 and the drive screw 211, in conjunction with the limiting action of the second guide rod 212. Through two transmissions—gear meshing and thread assembly—the transmission gap is greatly reduced, and the transmission ratio is precise and constant. This converts the rotational motion of the motor into the linear lifting motion of the lifting platform 21, precisely controlling the descent height of the lifting platform 21 to match the single-layer sintering thickness. This avoids positioning errors caused by transmission gaps and improves the dimensional accuracy of the sintered parts.

[0035] Reference Figure 4 and Figure 5 The forming cylinder 2 is equipped with an isolation plate 22 to isolate the metal powder from its bottom. The drive screw 211 is an incomplete screw, and its threaded part is located below the isolation plate 22.

[0036] This application uses this design to further improve the sealing of the molding chamber 1 and prevent metal powder from affecting the second drive assembly 5.

[0037] Reference Figure 2 The laser selective sintering system 4 includes: a laser 41, a laser emission chamber 6 horizontally arranged above the forming chamber 1, the laser 41 being arranged at the end of the laser emission chamber 6 away from the forming cylinder 2 for emitting a laser beam; a beam expander 42, arranged on one side of the laser 41 for adjusting the diameter and divergence angle of the laser beam; a scanning galvanometer 43, arranged directly above the forming cylinder 2 for controlling the scanning path of the laser beam; and a focusing lens 44, horizontally arranged below the scanning galvanometer 43 to focus the laser beam into a uniform spot on the surface of the lifting platform 21.

[0038] The original laser beam is first transmitted to the beam expander 42. The core function of the beam expander 42 is to adjust the diameter and divergence angle of the laser beam: on the one hand, it expands the small-diameter laser beam emitted by the laser 41 to a size suitable for the scanning range of the scanning galvanometer 43, avoiding the limitation of the scanning area due to the beam diameter being too small, or the energy dispersion due to the beam diameter being too large; on the other hand, it calibrates the divergence angle of the laser beam, adjusting the laser beam from a "divergent state" to a "collimated state", optimizing the uniformity of the laser energy distribution along the beam cross section, and eliminating the gradient defect of strong energy at the center and weak energy at the edge of the original laser beam. The laser beam, after beam expansion and calibration, is transmitted to the scanning galvanometer 43, which is set directly above the forming cylinder 2. The scanning galvanometer 43 incorporates a high-speed oscillating reflector, the deflection angle of which is controlled in real-time by a computer control system based on the two-dimensional contour data of the 3D part slice. Through rapid and precise oscillation, the reflector changes the direction of the laser beam, ensuring it covers the powder area to be sintered on the lifting platform 21 along a preset path while avoiding non-sintering areas, thus achieving the core function of "selective sintering." The high-speed response of the scanning galvanometer 43 significantly improves scanning efficiency and shortens the sintering time for a single layer. The laser beam, deflected by the scanning galvanometer 43, is transmitted vertically downwards to the focusing lens 44. The focusing lens 44 is also controlled in real-time by the computer control system based on the two-dimensional contour data of the 3D part slice to coordinate with the scanning galvanometer 43. The focusing lens 44 focuses the collimated laser beam into a uniform spot, projecting it onto the metal powder surface of the lifting platform 21.

[0039] Reference Figure 1 The device also includes a second linear actuator 7 and a sealing door 8. The molding chamber 1 is provided with an opening on the side near the molding cylinder 2 that is adapted to the sealing door 8. The sealing door 8 is provided at the opening in a way that allows it to be raised and lowered by the second linear actuator 7.

[0040] After the metal powder is sintered and formed, this application uses a computer control system to control the second linear actuator 7 to open the sealing door 8, so that the user can use tools to remove the workpiece.

[0041] The workflow is as follows: I. Initialization and Vacuum Environment Construction 1. The operator imports the 3D model of the part to be sintered through the external computer control system, completes the model slicing process, and sets process parameters such as single-layer sintering thickness, laser power, and scanning speed.

[0042] 2. The second linear actuator 7 drives the sealing door 8 to descend, closing the opening of the molding chamber 1; the vacuum pump system starts to pump air through the first air inlet 11 of the molding chamber 1, and pumps the molding chamber 1 to the preset vacuum level to avoid oxidation of the metal powder during the sintering process.

[0043] 3. The second drive assembly 5 receives the command, and the second rotary drive motor 53 drives the drive gear 52 to rotate. The drive gear 52 meshes with the rotating ring gear 51 to drive the drive screw 211 to rotate. Under the limiting action of the second guide rod 212, the lifting platform 21 is accurately pushed to the initial sintering position at the top of the molding cylinder 2.

[0044] 4. Fill the molding cylinder 2 with metal powder.

[0045] II. Metal Powder Conveying and Mixing 1. Metal powder is added to a powder mixing device to achieve uniform mixing. The mixed powder enters the second rigid pipe 35 through the third connecting pipe 36.

[0046] 2. The first rotary drive motor 371 starts and drives the conveying screw 372 to rotate; the spiral blades of the screw generate axial pushing force and radial stirring force, which on the one hand breaks up the powder agglomerates, and on the other hand conveys the powder to the direction of the first rigid pipe 33, and finally enters the movable cover 31 connected to the first rigid pipe 33.

[0047] III. Automated Powder Coating 1. The first linear actuator 321 drives the moving cover 31 to move back and forth along the bottom wall of the molding chamber 1. Several first guide rods 322 form a multi-point constraint on the moving cover 31 to prevent it from deflecting or tilting, and ensure that the moving cover 31 always moves parallel to the wall.

[0048] 2. During the movement of the moving cover 31, the telescopic pipe 34 will be stretched and the metal powder inside it will be evenly spread on the surface of the lifting platform 21 to form a powder layer with the same thickness as the slicing parameters. 3. After the powder is spread, the first drive component 32 drives the moving cover 31 to reset to the initial position, waiting for the next powder spreading command.

[0049] IV. Laser Selective Sintering Operation 1. The computer control system sends instructions to the laser selective sintering system 4 based on the two-dimensional contour data of the slice: the laser 41 emits a laser beam of a specific wavelength. The laser beam first enters the beam expander 42 to complete the diameter scaling and divergence angle calibration, and is converted into a collimated beam with uniform energy distribution.

[0050] 2. The collimated beam is transmitted to the scanning galvanometer 43 directly above the forming cylinder 2. The reflective mirror built into the scanning galvanometer 43 deflects at high speed and with precision, changing the path of the laser beam so that it covers the area of ​​the powder to be sintered on the lifting platform 21 according to the preset trajectory, thereby achieving "selective sintering".

[0051] 3. The laser beam deflected by the scanning galvanometer 43 is directed vertically downward and focused into a uniform spot by the focusing lens 44, which is then projected onto the surface of the powder layer. The laser energy causes the powder to melt and solidify rapidly, forming a single-layer sintered structure that is consistent with the outline of the slice.

[0052] V. Layer-by-layer cyclic molding 1. After the single-layer sintering is completed, the second drive component 5 is started again, driving the lifting platform 21 to descend precisely by one single-layer sintering thickness; the drive screw 211 is an incomplete screw, with the threaded section located below the isolation plate 22. The isolation plate 22 effectively blocks powder from penetrating into the drive area, avoiding contamination of the gear meshing pair and the threaded pair.

[0053] 2. The equipment repeats the cycle of "powder conveying → coating → laser sintering → lifting platform 21 descending", and finally forms a complete metal part by accumulating layer by layer.

[0054] 3. After the part is fully formed, the computer control system issues a stop command, the laser 41 stops working, the vacuum pump system is shut down, the second linear actuator 7 drives the sealing door 8 to rise, opening the molding chamber 1; the operator uses tools to directly remove the finished part from the molding cylinder 2.

[0055] The various mechanisms of this device are coordinated and controlled by a computer control system and its built-in programs.

[0056] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0057] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0058] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A metal powder sintering apparatus, characterized in that, include: A molding chamber (1) is provided on one side with a first air inlet (11) connected to a vacuum pump system; a molding cylinder (2) is provided at the bottom of the molding chamber (1), and a lifting platform (21) is provided inside the molding cylinder (2); a powder leveling mechanism (3) is provided on one side of the molding cylinder (2) for leveling metal powder on the lifting platform (21); a laser selective sintering system (4) and a computer control system are provided, the laser selective sintering system (4) is located above the molding cylinder (2), and the computer control system is located outside the molding chamber (1) for controlling the laser selective sintering system (4) to sinter the metal powder on the lifting platform (21).

2. The metal powder sintering apparatus according to claim 1, characterized in that, The powder leveling mechanism (3) includes: a movable cover (31) and a first driving assembly (32), wherein the movable cover (31) is reciprocally moved against the bottom wall of the molding chamber (1) via the first driving assembly (32); a first rigid pipe (33), one end of which is connected to the inside of the movable cover (31), and the other end extends horizontally out of the molding chamber (1); a telescopic pipe (34) and a second rigid pipe (35), wherein the second rigid pipe (35) and the first rigid pipe (33) are coaxially suspended on one side of the molding chamber (1), and the telescopic pipe (34) is coaxially arranged on the first rigid pipe (33). A rigid pipe (33) is connected to a second rigid pipe (35), with one end connected to the first rigid pipe (33) and the other end connected to the second rigid pipe (35); a third connecting pipe (36) is provided above the second rigid pipe (35), with one end connected to the outlet of the powder mixing device and the other end connected to the second rigid pipe (35); a metal powder conveying assembly (37) is provided inside the second rigid pipe (35) to convey metal powder into the movable cover (31).

3. The metal powder sintering apparatus according to claim 2, characterized in that, The first drive assembly (32) includes a first linear driver (321) and a first guide rod (322). The movable cover (31) can be moved back and forth toward the molding cylinder (2) by the first linear driver (321), and a plurality of first guide rods (322) are provided on one side of it horizontally through the molding chamber (1) along its moving direction.

4. The metal powder sintering apparatus according to claim 2, characterized in that, The metal powder conveying assembly (37) includes a first rotary drive motor (371) and a conveying screw (372), wherein the conveying screw (372) is rotatably disposed inside the second rigid pipe (35) via the first rotary drive motor (371).

5. The metal powder sintering apparatus according to claim 4, characterized in that, The conveying screw (372) is coaxially provided with a guide roller (3721) at the end away from the first rotary drive motor (371), and a guide frame (331) adapted to the guide roller (3721) is provided inside the first rigid pipe (33).

6. The metal powder sintering apparatus according to claim 1, characterized in that, The device further includes a second drive assembly (5) for driving the lifting platform (21) to rise and fall; wherein the second drive assembly (5) includes: a rotating ring tooth (51), a driving screw (211) is provided on the bottom of the lifting platform (21) extending vertically out of the forming cylinder (2), and a second guide rod (212) is provided on the opposite sides of the forming cylinder (2), the bottom of the forming cylinder (2) is rotatably provided with a rotating ring tooth (51), the rotating ring tooth (51) is coaxially threadedly assembled with the driving screw (211); a drive gear (52) and a second rotary drive motor (53), the drive gear (52) is rotatably provided on one side of the rotating ring tooth (51) through the second rotary drive motor (53), and meshes with the rotating ring tooth (51).

7. The metal powder sintering apparatus according to claim 6, characterized in that, The molding cylinder (2) is provided with an isolation plate (22) for isolating the metal powder from its bottom. The drive screw (211) is an incomplete screw, and its threaded part is located below the isolation plate (22).

8. The metal powder sintering apparatus according to claim 1, characterized in that, The laser selective sintering system (4) includes: a laser (41), and a laser emission chamber (6) is horizontally arranged above the forming chamber (1). The laser emission chamber (6) is located at one end away from the forming cylinder (2) and is used to emit a laser beam; a beam expander (42), which is located on one side of the laser (41) and is used to adjust the diameter and divergence angle of the laser beam; a scanning galvanometer (43), which is located directly above the forming cylinder (2) and is used to control the scanning path of the laser beam; and a focusing lens (44), which is horizontally arranged below the scanning galvanometer (43) to focus the laser beam into a uniform spot on the surface of the lifting platform (21).

9. The metal powder sintering apparatus according to claim 1, characterized in that, The device also includes a second linear actuator (7) and a sealing door (8). The molding chamber (1) is provided with an opening that is adapted to the sealing door (8) on the side near the molding cylinder (2). The sealing door (8) is provided at the opening via the second linear actuator (7).

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