An ultrasonic vibration and powder collection platform for laser additive manufacturing

Abstract

The application discloses an ultrasonic vibration and powder collection platform for laser additive manufacturing, and aims to solve the problems of hole defects in the deposition process and difficult waste powder recovery. The platform comprises a sliding block hinge mechanism, a supporting rod, a powder blocking mechanism, a moving clamping platform, a powder screening and collecting device and an ultrasonic vibration mechanism. By setting the adjustable powder blocking mechanism on the supporting rod and equipping the high-temperature-resistant Teflon film, the drifting of unused powder can be effectively blocked and guided into the recovery container, so that the waste powder recovery efficiency is improved and the mixing of different material powders is avoided. The moving clamping platform adopts the first and second clamping assemblies and a servo double-rod hydraulic cylinder to realize efficient clamping and stability of the substrate, has the anti-slip and anti-powder residue design, and can ensure the clamping stability and platform cleanliness in the deposition process.

Description

Technical Field

[0001] The present invention relates to the field of laser additive manufacturing, and in particular to an ultrasonic vibration and powder collection platform for laser additive manufacturing of spatial heterogeneous structures. Background Art

[0002] With the advancement of industrial technology, laser directed energy deposition (LDED) technology has shown great potential in manufacturing complex structures and spatial heterogeneous materials, especially in the fields of aerospace, energy, and mold manufacturing. LDED technology can use lasers to quickly melt metal powders, and by precisely controlling the morphology and temperature of the molten pool, deposit materials layer by layer to form three-dimensional components. This additive manufacturing method can not only produce parts with complex shapes and excellent performance, but also effectively reduce material waste in the manufacturing process and improve production efficiency. However, despite the many advantages of LDED technology, there are still some technical challenges, especially in the deposition process of heterogeneous powder materials.

[0003] During the laser deposition (LDED) process, the deposition path for heterogeneous materials typically involves the alternating deposition of multiple materials, forming a layered / voxelized structure with varying physical properties. Due to the varying deposition paths and material selection, a range of defects often occur during the deposition process, particularly the formation of voids. Voids are primarily caused by the poor evacuation of gases, such as metal vapor and shielding gas, during the rapid cooling process of deposition. Specifically, during laser deposition, as materials are layered, the formation of grooves within the molten pool hinders gas evacuation, resulting in voids. These defects not only affect the mechanical properties of the component but also lead to structural instability in the finished product, potentially failing to meet engineering requirements. To address this issue, prior art methods have employed ultrasonic vibration to enhance the fluidity of the molten pool, promote gas evacuation, and prevent void formation (see CN119187612A / CN119187611A / CN118926545A, etc.). However, ultrasonic vibration only addresses voids; another challenge in the LDED process is powder recycling. Although unused powder in LDED is essentially unreusable due to thermal radiation, the recovery, classification, and recycling of waste powder remains a valuable and unresolved technical direction due to the wide variety of powder types and large price differences. Especially in the case of additive manufacturing with heterogeneous powders, the current clamping platform (stage) will accumulate powder, and the mixing of different powder materials makes powder recovery more complicated, resulting in low recycling efficiency, which in turn affects the green sustainability and economic efficiency of the manufacturing process. There is an urgent need to design a clamping platform that facilitates the recycling of heterogeneous waste powder.

[0004] At the same time, due to the extremely high precision requirements of the LDED process, the additive substrate must maintain a stable clamping position throughout the deposition process to avoid any deviation affecting the deposition quality. However, traditional clamping platforms (stages) often have problems such as loose clamping and inaccurate positioning. In particular, the disturbance of powder and gas during the laser additive process of heterogeneous powders may cause changes in the position of the additive substrate, thereby affecting the deposition accuracy. In order to solve this problem, it is necessary to design a clamping platform that can stably clamp the additive substrate and be equipped with an adjustment mechanism that can adapt to different substrate sizes, while ensuring that no additional errors are introduced during the clamping process; and how to effectively integrate the ultrasonic vibration system with the LDED clamping platform to ensure good contact between the ultrasonic transducer and the additive substrate and maximize the use of the vibration effect is still a direction that needs to be solved urgently.

[0005] Furthermore, waste powder recycling and disposal has always been a key issue in the LDED process, especially in the manufacture of heterogeneous materials. Due to the use of a variety of additive powder materials, incompletely melted waste powder and splashed material are often affected by thermal radiation, causing their structure to change and making them incapable of direct recycling. The recycling prices of different additive powders vary significantly, making the classification and collection of waste powder particularly important. Traditional powder collection methods often fail to effectively achieve high-purity classified recycling. Summary of the Invention

[0006] In order to solve the technical problems existing in the prior art, the present invention discloses an ultrasonic vibration and powder collection platform for laser additive manufacturing.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] An ultrasonic vibration and powder collection platform for laser additive manufacturing, comprising a shell, a slider hinge mechanism, a support rod, a powder blocking mechanism, a mobile clamping platform, an ultrasonic vibration platform and a powder screening and collecting device; the top of the shell is open, and two rectangular holes are respectively provided on two opposite side surfaces of the shell, the two ends of the two support rods are placed on the same horizontal plane and are connected to the slider hinge mechanism after passing through the rectangular holes, and the slider hinge mechanism is provided on the outer wall of the shell; a clamping mobile platform is fixedly installed on the middle section of the two support rods, and a driving device and a clamping assembly are provided on the clamping mobile platform, the driving device drives the two support rods to move toward or away from each other, and the clamping assembly is used to clamp the workpiece; the mobile clamping platform is also equipped with an ultrasonic vibration mechanism; powder blocking mechanisms are provided on both sides of the clamping mobile platform, and a slide plate is provided in the rectangular hole, the powder blocking mechanism and the slide plate are both controlled by the support rod, and a powder screening and collecting device is also provided below the shell.

[0009] As a further technical solution, the slider hinge mechanism includes a horizontal slider, which is placed in a limiting slide groove and hinged to one end of the connecting rod. The other end of the connecting rod is connected to a vertical slider through a hinge. The vertical slider is sleeved on a guide slide rod, and the guide slide rod is fixed on a slide rod seat and a slide rod bracket. The slide rod seat and the slide rod bracket are fixed to the outer wall of the shell.

[0010] As a further technical solution, the powder blocking mechanism consists of a powder blocking plate, a clockwork spring and a Teflon film. The two powder blocking plates are mounted on two support rods and can slide relative to the support rods. The clockwork spring is fixed on one of the powder blocking plates. The Teflon film is wrapped around the clockwork spring, and the end of the Teflon film is fixed to the other powder blocking plate.

[0011] As a further technical solution, the clamping assembly includes a first clamping assembly and a second clamping assembly; the first clamping assembly is arranged along the X direction, and the second clamping assembly is arranged along the Y direction.

[0012] As a further technical solution, the first clamping assembly is composed of a pair of first clamping claws and a pair of first adjusting knobs, and the first adjusting knobs adjust the height of the first clamping claws.

[0013] As a further technical solution, the second clamping assembly is composed of second claws arranged in pairs, each second claw is sleeved on its corresponding second claw slide, and the second claw is connected to the second adjusting knob through a transmission structure, and the second claw can be adjusted to move up and down along the second claw slide by rotating the second adjusting knob; the two second claw slides are installed at both ends of the telescopic rod, and the telescopic rod is installed in a channel machined on the side of the mobile clamping platform; a spring is sleeved on the telescopic rod, and the spring is located between the side of the mobile clamping platform and the inner wall of the second claw slide.

[0014] As a further technical solution, the driving device is a horizontally arranged servo double-rod hydraulic cylinder, both ends of the servo double-rod hydraulic cylinder are connected to a mobile clamping platform, and the mobile clamping platform is fixed on two support rods.

[0015] As a further technical solution, a telescopic mechanism is further provided between the inner end surfaces of the movable clamping platform.

[0016] As a further technical solution, the telescopic mechanism is a scissor-type folding frame, and the scissor-type folding frame is arranged on the outside of the driving device.

[0017] As a further technical solution, the ultrasonic vibration mechanism consists of an ultrasonic transducer, a support plate, a support platform, a vibration damping pedestal and an ultrasonic vibration platform. The ultrasonic transducer is installed on the vertical support plate and connected to the ultrasonic generator. The support plate is fixed to the support platform by screws. The support platform is fixed to the servo double-rod hydraulic cylinder body by snaps. The support platform is also equipped with a vibration damping pedestal. The ultrasonic vibration platform is installed above the vibration damping pedestal. The side of the octagonal prism fixed below the ultrasonic vibration platform is in contact with the output end of the ultrasonic transducer.

[0018] As a further technical solution, the powder screening and collecting device includes a cover plate and a waste powder conveying and screening mechanism. The waste powder conveying and screening mechanism consists of a partition, a conveyor belt, a mobile funnel, a funnel drive assembly, a powder screening mechanism, a powder screening drive assembly and a support frame. The partition is installed between the cover plate and the conveyor belt support frame. The inner wall of the partition parallel to the moving direction of the conveyor belt is smoothed. The partition is integrally connected with a closing baffle above the tail end of the conveyor belt. A mobile funnel is set at the tail end of the conveyor belt. The mobile funnel is driven by the funnel drive assembly to move along the direction of the powder screening mechanism. The powder screening mechanism is driven by the powder screening drive assembly.

[0019] As a further technical solution, the powder screening mechanism consists of a partition plate, a coarse particle powder collection box, a fine particle powder collection box, a universal rolling ball and an inclined panel. The inclined panel is divided into multiple parts by the partition plate, which correspond to the waste powder screening areas of different materials respectively. The upper half of the inclined panel is processed with fine sieve holes, and a fine particle powder collection box is installed under the inclined panel with fine sieve holes. The lower half of the inclined panel is processed with coarse sieve holes, and a coarse particle powder collection box is installed under the inclined panel with coarse sieve holes. A universal rolling ball is movably connected under the powder collection box to support the powder collection box, and the universal rolling ball is embedded in the bottom plate of the waste powder collection device shell.

[0020] Beneficial effects of the present invention:

[0021] The ultrasonic vibration and powder collection platform for laser additive manufacturing proposed in this invention achieves stable clamping and precise positioning of additive substrates through the interaction between a slider hinge mechanism, a mobile clamping platform, and support rods. A powder retaining mechanism improves waste powder recovery efficiency. A powder screening and collection device allows for waste powder recovery from different materials, simultaneously screening the waste powder. The ultrasonic vibration device enhances the fluidity and stability of the molten pool, promotes gas discharge, reduces inclusions, and prevents the formation of voids. It also improves the density and performance of additive parts by refining grains and optimizing heat distribution. The mobile clamping platform utilizes first and second clamping assemblies and a servo dual-rod hydraulic cylinder to efficiently and securely clamp the substrate. It features an anti-slip and anti-powder residue design to ensure clamping stability and platform cleanliness during deposition. The waste powder screening and collection device not only improves waste powder recovery efficiency but also ensures the purity of different powder materials, meeting the environmental protection and resource recycling requirements of modern additive manufacturing. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of ultrasonic vibration and powder collection platform;

[0023] Figure 2 It is a partial enlarged view of the slider hinge mechanism;

[0024] Figure 3 Schematic diagram of powder blocking mechanism;

[0025] Figure 4 This is a partial enlarged view of the ultrasonic vibration clamping platform;

[0026] Figure 5 A partial enlarged view of the clamping assembly;

[0027] Figure 6 This is a half-section diagram of the ultrasonic vibration clamping platform;

[0028] Figure 7 This is a top view of the waste powder screening and collection device;

[0029] Figure 8 It is a half-section diagram of the waste powder screening and collection device;

[0030] Figure 9 This is a partial enlarged view of the powder screening mechanism;

[0031] Figure 10 This is a partial enlarged view of the driving mechanism.

[0032] In the figure: 1. Slider hinge mechanism; 11. Limiting slide; 12. Horizontal slider; 13. Slide plate; 14. Slide rod seat; 15. Connecting rod; 16. Guide slide rod; 17. Hinge; 18. Vertical slider; 19. Slide rod bracket;

[0033] 2. Support rod;

[0034] 3. Powder blocking mechanism; 31. Powder blocking plate; 32. Spring; 33. Teflon film;

[0035] 4. Mobile clamping platform; 41. First clamping assembly; 411. First clamping jaw; 412. First adjustment knob; 42. Second clamping assembly; 421. Second clamping jaw; 422. Second clamping jaw slide; 423. Second adjustment knob; 424. Telescopic rod; 425. Spring;

[0036] 5. Telescopic mechanism; 51. Folding frame; 52. Slider; 521. Slide; 53. Rotating shaft; 54. Servo double-rod hydraulic cylinder; 541. Saddle buckle;

[0037] 6. Ultrasonic vibration mechanism; 61. Ultrasonic transducer; 62. Support plate; 63. Support platform; 64. Vibration reduction base; 65. Ultrasonic vibration platform;

[0038] 7. Housing; 71. L-shaped door; 72. Handle;

[0039] 8. Powder screening and collection device;

[0040] 81. Cover plate; 811. Waste powder screening and collection device housing; 812. Sliding door; 813. Handle; 814. Fixed card slot;

[0041] 82. Waste powder conveying and screening mechanism; 821. Partition plate; 8211. Closing baffle; 822. Conveyor belt; 823. Mobile funnel; 8231. Powder outlet; 8232. Support plate; 8233. Chute; 824. Funnel drive assembly; 8241. Motor base; 8242. Servo motor; 8243. Gear; 8244. Straight rack; 825. Powder screening mechanism; 8251. Partition plate; 8252. Coarse screen hole; 8253. Coarse-grained powder collection box; 8254, fine sieve hole; 8255, fine-grained powder collection box; 8256, universal ball; 8257, inclined plate; 826, powder screening drive assembly; 8261, motor base; 8262, servo motor; 8263, eccentric wheel; 8264, disc; 8265, transmission rod; 8266, spring; 8267, support plate; 8268, support spring; 8269, reciprocating block; 827, support frame. DETAILED DESCRIPTION

[0042] In order to better understand the technical content of the present invention, specific embodiments are given and described below with reference to the accompanying drawings.

[0043] Various aspects of the present invention are described in this disclosure with reference to the accompanying drawings, in which many illustrative embodiments are shown. The embodiments of the present disclosure are not necessarily intended to include all aspects of the present invention. It should be understood that the various concepts and embodiments described above, as well as those described in more detail below, can be implemented in any of many ways using any ultrasonic vibration and powder collection platform, because the concepts and embodiments disclosed herein are not limited to any embodiment. In addition, some aspects of the present disclosure can be used alone or in any appropriate combination with other aspects disclosed herein.

[0044] For laser directed energy deposition of spatial heterogeneous structure materials or heterogeneous powder materials, due to its special deposition path (i.e., first depositing 1, 3, 5 times, then depositing 2, 4, 6 times), when the latter material is used to deposit the groove part or to deposit the next layer, hole defects often appear, i.e. Figure 7 The hole defect 6 in the molten metal is due to the surface tension of the molten metal and the rapid cooling characteristics of LDED (especially the bottom of the molten pool is close to the substrate side, far away from the heat source and has a good heat conduction effect). When the groove is formed between the deposition 1, 3, and 5 passes, the bottom end of the groove is usually deep and narrow. The metal vapor or protective gas generated in the molten pool may not be able to escape smoothly from the inside of the groove, which will cause the bonding strength of the added spatial heterogeneous structure material to deteriorate and affect its comprehensive performance. In response to the above defects, a clamping platform with an ultrasonic vibration device can be designed. Ultrasonic vibration can enhance the fluidity and stability of the molten pool, promote the discharge of gas, reduce the inclusion of gas and oxides, and avoid the formation of holes. In addition, ultrasonic vibration can accelerate the solidification of metal, refine grains, improve the density of additive parts, and reduce defects caused by uneven cooling. By optimizing the metal flow and heat distribution of the molten pool, ultrasonic vibration helps to avoid local overheating or overcooling, ensure the stability of the welding process, and thus effectively eliminate hole defects and improve welding quality.

[0045] Furthermore, unused powder ejected from the laser head cannot usually be directly recycled and reused due to changes in its structure caused by thermal radiation. However, it can be recycled as waste. However, since heterogeneous structural materials require a variety of additive powders and the recycling prices of different powder materials vary greatly, it is necessary to classify and collect waste additive powder, which is also in line with the concept of green and sustainable development. However, with current clamping devices, unused additive powder tends to accumulate on the surface of the platform rather than falling directly into the recycling container, increasing the difficulty of powder recovery and potentially causing powders of different materials to mix, affecting the economic efficiency of recycling. In addition, ultrasonic vibration clamping devices tend to cause powder to accumulate in the corners and crevices of the clamping platform during vibration, further complicating cleaning and maintenance. Therefore, it is urgent to design an ultrasonic vibration and powder collection platform that is easy to recover heterogeneous powder, so as to improve the comprehensive performance of spatial heterogeneous structural materials and the efficiency of heterogeneous powder recovery.

[0046] The acoustic vibration clamping platform disclosed in this embodiment is composed of a slider hinge mechanism 1, a support rod 2, a powder blocking mechanism 3, a mobile clamping platform 4, a telescopic mechanism 5, an ultrasonic vibration mechanism 6 and a housing 7.

[0047] The housing 7 is a rectangular housing with an open top, and two rectangular holes are provided on two opposite sides of the housing 7; Figure 1 Two rectangular holes are respectively provided on the left and right sides of the shell 7, and the rectangular hole on the left side is arranged opposite to the rectangular hole on the right side; a slide rail is provided on the top surface and the ground inside each rectangular hole, and a slide plate 13 is provided inside the slide rail; that is, four rectangular holes correspond to four slide plates 13, and each slide plate 13 can close its corresponding rectangular hole under the drive of the support rod 2 to prevent the escape of powder during LDED.

[0048] The support rods 2 include two, and the two ends of the two support rods 2 are placed on the same horizontal plane, the two ends of one of the support rods 2 pass through a pair of rectangular holes arranged opposite to each other on the corresponding left and right sides, and the slide 13 in the rectangular hole is connected to the support rod 12, and the two slides 13 are controlled by the support rod to move linearly in the horizontal direction; the two ends of the other support rod 2 pass through another pair of rectangular holes arranged opposite to each other on the corresponding left and right sides, and the slide 13 in the rectangular hole is connected to the support rod 12, and the two slides 13 are controlled by the support rod to move linearly in the horizontal direction; the two support rods 2 can drive four slides 13 to slide synchronously at the same time; when the slide 13 slides synchronously with the support rod 2 in the horizontal X direction, the slide 13 can close the rectangular hole to prevent the escape of powder during LDED.

[0049] Further, the four ends of the two support rods 2 extend outside the four rectangular holes of the shell 7, and each is connected to a horizontal sliding block 12; the horizontal sliding block 12 is placed in a limiting sliding groove 11 and is hinged to one end of a connecting rod 15, the limiting sliding groove 11 is fixed on the outer wall of the shell; the other end of the connecting rod 15 is connected to a vertical sliding block 18 through a hinge 17, the vertical sliding block 18 is sleeved on a guide sliding rod 16, the guide sliding rod 16 is fixed on a sliding rod seat 14 and a sliding rod support 19, the sliding rod seat 14 and the sliding rod support 19 are fixed on the outer wall of the shell 7 through screws, that is, when the support rod 2 moves in the X direction, the horizontal sliding block 12 will slide horizontally along the limiting sliding groove 11, and then drive the vertical sliding block 18 to slide vertically along the guide sliding rod 16 through the connecting rod 15, but since the horizontal sliding blocks 12 fixed to the two support rods 2 are hinged to the same vertical sliding block 18 through the connecting rod 15, the horizontal sliding block 12 and the support rod 2 can only slide symmetrically, ensuring that the center line of the two support rods 2 is always on the YZ plane.

[0050] Further, the support rod 2 inside the shell 7 is also provided with a powder blocking mechanism 3, the powder blocking mechanism 3 includes two, located on both sides of the ultrasonic vibration mechanism 6, to achieve powder blocking;

[0051] Specifically, each powder blocking mechanism 3 is composed of two powder blocking plates 31, a spring 32 and a Teflon film 33 (high temperature resistant), the two powder blocking plates 31 are sleeved on the two support rods 2 and can slide manually relative to the support rods 2, the spring 32 is fixed on one of the powder blocking plates 31, the Teflon film 33 is wound on the spring 32, and the end of the Teflon film 33 is fixed with the other powder blocking plate 31, when the support rod 2 slides away from the YZ plane, the Teflon film 33 is pulled out of the spring 32, when the support rod 2 slides towards the YZ plane, the Teflon film 33 is wound up again under the restoring force of the spring 32, ensuring that the width of the powder blocking mechanism 3 always matches the distance between the two support rods 2, at the same time, according to the size of the placed additive substrate, the position of the powder blocking mechanism 3 on the support rod 2 can be manually adjusted (dialing along the Y direction), when the LDED space heterostructure material is used, the unused powder will be blocked by the powder blocking mechanism 3 and fall into the container below, avoiding the scattering of the powder, and the upper arc surface design of the support rod 2 is not conducive to the residue of the powder, the above design will help the recycling of waste powder and the cleanliness of the clamping platform.

[0052] Furthermore, a mobile clamping platform 4 is fixedly mounted on the middle section of the support rod 2, and each of the mobile clamping platforms 4 is mounted with a first clamping assembly 41 and two second clamping assemblies 42. Specifically, the first clamping assembly 41 is composed of a pair of first clamping claws 411 and a pair of first adjusting knobs 412. By rotating the first adjusting knobs 412, the upper and lower positions of the corresponding first clamping claws 411 can be adjusted through the built-in screw and nut mechanism (the screw rotates and the nut moves, not shown in the figure) to cope with additive substrates of different thicknesses.

[0053] Furthermore, a telescopic mechanism 5 is provided between the inner end faces of the mobile clamping platform 4. Specifically, the telescopic mechanism 5 consists of a folding frame 51, a slider 52, a slide groove 521, a rotating shaft 53, a servo double-rod hydraulic cylinder 54 and a saddle buckle 541. The two ends of one side of the above-mentioned folding frame 51 are respectively fixed to the slider 52 and the rotating shaft 53, and the two rods of the above-mentioned servo double-rod hydraulic cylinder 54 are fixed on the inner end face of the mobile clamping platform 4. That is, in the stage of clamping the additive substrate before laser directional energy deposition, the servo double-rod hydraulic cylinder 54 receives the signal and starts to simultaneously control the telescopic rods on both sides to drive the mobile clamping platform 4 to move a distance away from the YZ plane (there is enough space to place the substrate), and the mobile clamping platform 4 is fixed on the support rod 2. Due to the limitation of the slider hinge mechanism 1, the support rod 2 and the mobile clamping platform 4 can only move symmetrically along the YZ plane. As a result, the cylinder position of the servo double-rod hydraulic cylinder 54 remains unchanged, and as the mobile clamping platform 4 moves to both sides The folding frame 51 moves sideways, the folding frame 51 extends, the slider 52 connected to one end of the folding frame begins to slide along the slide groove 521, and the rotating shaft 53 connected to the other end rotates a corresponding angle, ensuring the stability of the entire mechanism and preventing the mobile clamping platform 4 from tilting during movement. Then, the handle 72 is pulled to open the L-shaped cabinet door 71 on the shell 7, and the additive substrate is placed on the mobile clamping platform 4. The servo double-rod hydraulic cylinder 54 controls the telescopic rods on both sides to drive the mobile clamping platform 4 to return until the pair of first clamping claws 411 contact the side of the additive substrate and then slowly retract. The first clamping claw 411 is equipped with a pressure sensor (not shown in the figure). When the pressure sensor measurement value reaches a predetermined value, it transmits an instruction to control the servo double-rod hydraulic cylinder 54 to stop working. At this time, the entire mobile clamping platform 4 has been hidden under the additive substrate, with only a pair of first clamping claws 411 clamping the two sides of the substrate. At the same time, the second clamping mechanism 42 also fixes the substrate from other sides.

[0054] Specifically, the second clamping assembly 42 consists of two second claws 421 arranged opposite to each other, each second claw 421 is sleeved on its corresponding second claw slide 422, and the second claw 421 is connected to the second adjusting knob 423 through a transmission structure, and the second claw 421 can be adjusted to move up and down along the second claw slide 422 by rotating the second adjusting knob 423; the two second claw slides 422 are installed at both ends of the telescopic rod 424, and the telescopic rod 424 is installed in the channel machined on the side of the mobile clamping platform 4; a spring 425 is sleeved on the telescopic rod 424, and the spring 425 is located between the side of the mobile clamping platform 4 and the inner wall of the second claw slide 422; that is, according to the Y-direction dimension of the additive substrate, the second claw slide 422 is pulled to the side of the additive substrate, and the restoring force of the spring 425 is used to clamp the second claw 421 to the side of the additive substrate. The final clamping state is that only three pairs of claws are clamped on the side of the substrate to ensure as little residual powder as possible on the platform.

[0055] Furthermore, the second clamping jaw 421 is mounted on the second clamping jaw slide 422 (to prevent powder from remaining on the clamping jaw slide), and the upper part of the second clamping jaw 421 (the first clamping jaw 411) is designed to be inclined. Combined with the blowing effect of the coaxial protective gas of the laser head during the additive manufacturing process, it can effectively reduce the powder remaining on the clamping jaw during LDED of spatial heterogeneous structure materials, and ensure that after the material is deposited, there is as little powder as possible on the entire ultrasonic vibration platform, ensuring the cleanliness of the entire clamping platform; in addition, the second clamping jaw 421 is also designed with an anti-slip groove (not shown in the figure) to enhance the holding force and stability.

[0056] Furthermore, an ultrasonic vibration mechanism 6 is mounted in the middle of the mobile clamping platform 4. Specifically, the ultrasonic vibration mechanism 6 is composed of an ultrasonic transducer 61, a support plate 62, a support platform 63, a vibration reduction base 64 and an ultrasonic vibration platform 65.

[0057] The ultrasonic transducer 61 is mounted on a vertical support plate 62 and connected to an ultrasonic generator (not shown in the figure). The support plate 62 is fixed to a support platform 63 by screws. The support platform 63 is fixed to the cylinder body of the servo double-rod hydraulic cylinder 54 by a saddle buckle 541. The support platform 63 is also equipped with a vibration damping base 64. An ultrasonic vibration platform 65 is mounted above the vibration damping base 64. The side surface of the octagonal prism fixed below the ultrasonic vibration platform 65 is in contact with the output end of the ultrasonic transducer 61. That is, when LDED of spatial heterogeneous structure materials is performed, the ultrasonic transducer starts working synchronously, and the generated ultrasonic vibration directly acts on the ultrasonic vibration platform 65. The upper part of the ultrasonic vibration platform 65 is in contact with the additive substrate, further transmitting the ultrasonic vibration to the additive substrate. By utilizing ultrasonic vibration and cavitation effects, the solidification structure of the spatial heterogeneous structure material is refined in grain size and uniform in composition, thereby reducing void defects.

[0058] Furthermore, in terms of spatial position, a powder screening and collecting device 8 is designed below the ultrasonic vibration clamping platform. Specifically, the powder screening and collecting device 8 is composed of a waste powder screening and collecting device cover 81 and a waste powder conveying and screening mechanism 82. Specifically, the waste powder conveying and screening mechanism 82 is composed of a partition 821, a conveyor belt 822, a movable funnel 823, a funnel driving assembly 824, a powder screening mechanism 825, a powder screening driving assembly 826 and a support frame 827. The partition 821 is installed between the cover 81 and the conveyor belt support frame 827. The inner wall of the partition 821 parallel to the moving direction of the conveyor belt is smoothed, which is conducive to the waste powder sliding onto the conveyor belt 822. In addition, the partition 821 is at the end of the conveyor belt 822. A closing baffle 8211 is integrally connected to the upper end, and a scraper (not shown in the figure) is provided between the tail end of the conveyor belt 822 and the movable funnel 823. The movable funnel 823 can be driven by the funnel drive assembly 824 to move along the slide groove 8233 processed on the support plate 8232; in this embodiment, the reason for designing the movable funnel 823 as a funnel that can move back and forth is mainly to align the powder outlet 8231 with different material waste powder screening areas. For example, in the present invention, screening areas for waste powder of material A, waste powder of material B and waste powder of material C are designed. Therefore, by controlling the movement of the movable funnel 823, waste powder of material A, waste powder of material B and waste powder of material C can be sent to different screening areas.

[0059] Specifically, the funnel drive assembly 824 consists of a motor base 8241, a servo motor 8242, a gear 8243, and a spur rack 8244. The spur rack 8244 is located above the mobile funnel 823 and meshes with the gear 8243. The gear 8243 is fixed to the output shaft of the servo motor 8242. The servo motor 8242 is installed in the motor base 8241. The motor base 8241 is fixed to the lower side of the cover plate 81 by screws. A powder outlet 8231 is machined at the bottom of the mobile funnel 823. The waste powder of the additive material is transported to the powder screening mechanism 825 through the powder outlet 8231.

[0060] Specifically, the powder screening mechanism 825 is composed of a partition plate 8251, a coarse particle powder collecting box 8253, a fine particle powder collecting box 8255, a universal rolling ball 8256 and an inclined plate 8257, and the inclined plate 8257 is divided into three parts by the partition plate 8251, corresponding to the screening areas of waste powder of material A, waste powder of material B and waste powder of material C respectively; in addition, the upper half of the inclined plate 8257 is processed with fine sieve holes 8254, and a fine particle powder collecting box 8255 is installed below the inclined plate 8257 with the fine sieve holes 8254. The collecting box 8255 and the lower half of the inclined plate 8257 are machined with coarse sieve holes 8252. A coarse particle powder collection box 8253 is installed below the inclined plate 8257 with the coarse sieve holes 8252. A universal ball 8256 is movably connected below the powder collection box to support the powder collection box. The universal ball 8256 is embedded in a hemispherical hole of appropriate size machined on the bottom plate of the waste powder collection device housing 811. Furthermore, the powder screening mechanism 825 is reciprocated by the powder screening drive assembly 826 to achieve the powder screening function;

[0061] Furthermore, the above-mentioned inclined panel 8257 can also be divided into two parts or four parts by the partition plate 8251, which is specifically determined according to the type of material.

[0062] Specifically, the powder screening drive assembly 826 is composed of a motor base 8261, a servo motor 8262, an eccentric wheel 8263, a disc 8264, a transmission rod 8265, a spring 8266, a support plate 8267 and a support spring 8268. The motor base 8261 is fixedly connected to the upper side of the bottom plate of the waste powder collecting device housing 811, the servo motor 8262 is installed in the motor base 8261, and the output shaft of the servo motor 8262 is fixedly connected to the eccentric wheel 8263. The side of the eccentric wheel 8263 is in contact with the disc. The disk 8264 is in contact with each other, and a transmission rod 8265 is connected to the center of the disk 8264. The transmission rod 8265 horizontally passes through the corresponding through hole machined on the support plate 8267. The transmission rod 8265 is provided with a spring 8266 between the disk 8265 and the support plate 8267. A reciprocating block 8269 is fixedly installed on the end face of the transmission rod 8265. The other side of the reciprocating block 8269 is slidably connected to the side of the powder collection box. A support spring 8268 is installed between the support plate 8267 and the side of the powder collection box.

[0063] In addition, a fixed slot 814 is fixedly connected to the inner wall of the sliding door 812, and the fixed slot 814 is used to fix the support plate 8267 to prevent the support plate 8267 from shaking under the reciprocating movement of the transmission rod 8265. The support spring 8268 and the universal ball 8256 cooperate to achieve the reciprocating vibration and support of the powder screening mechanism 825.

[0064] During LDED of spatial heterogeneous structure materials, after a layer of powder A is deposited, the powder falls onto the conveyor belt 822. Thereafter, the conveyor belt starts to transport waste powder A. When powder A reaches the tail of the conveyor belt 822, the closing baffle 8211 gathers waste powder A. The gathered waste powder A is then directed to the mobile funnel 823 via a scraper (not shown). At this time, the powder outlet 8231 corresponds to the area corresponding to powder A on the inclined plate 8257 of the powder screening mechanism 825. At the same time, the servo motor 8262 receives a signal and starts to drive the eccentric wheel 8263 to rotate. Under the coordinated action of the eccentric wheel 8263 and the return spring 8266, the disc 8264 and the transmission rod 8265 begin to move back and forth in the horizontal direction and pass through The reciprocating block 8269 transmits power to the powder collection box to realize the vibration of the powder screening mechanism. Then, the waste powder A on the inclined plate 8257 first passes through the fine screen hole area, and the powder that has not been melted and is only affected by heat radiation passes through the fine screen hole 8254 and falls into the fine particle powder collection box 8255. The waste materials such as splashes generated during melting or LDED will fall into the fine particle powder collection box 8253 through the coarse screen hole 8252 under the inclined plate 8257. The conveyor belt 822 will stop moving after rotating half a circle, and then the B powder will be deposited. At the same time, the servo motor 8242 starts working to drive the mobile funnel 823 to slide along the slide 8233, and move the powder outlet 8231 to the B powder screening area for subsequent screening work.

[0065] Furthermore, the waste powder collecting device housing 811 is provided with a drawer door 812 and a handle 813 , that is, after the deposition work is completed, the drawer door 812 can be opened to take out the collected heterogeneous waste powder.

[0066] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. An ultrasonic vibration and powder collection platform for laser additive manufacturing, characterized in that: The invention comprises a shell, a slider hinge mechanism, a support rod, a powder blocking mechanism, a movable clamping platform, an ultrasonic vibration platform and a powder screening and collecting device; the top of the shell is open, and two rectangular holes are respectively provided on two opposite side surfaces of the shell, and the two ends of the two support rods are placed on the same horizontal plane and are connected to the slider hinge mechanism after passing through the rectangular holes, and the slider hinge mechanism is provided on the outer wall of the shell; a clamping movable platform is fixedly installed on the middle section of the two support rods, and a driving device and a clamping assembly are provided on the clamping movable platform, and the driving device drives the two support rods to move toward or away from each other, and the clamping assembly is used to clamp the workpiece; the movable clamping platform is also equipped with an ultrasonic vibration mechanism; powder blocking mechanisms are provided on both sides of the clamping movable platform, and slide plates are provided in the rectangular holes, and the powder blocking mechanism and the slide plates are both controlled by the support rods; a powder screening and collecting device is also provided under the shell; The slider hinge mechanism includes a horizontal slider, which is placed in a limiting slide groove and hinged to one end of a connecting rod. The other end of the connecting rod is connected to a vertical slider via a hinge. The vertical slider is sleeved on a guide slide rod, which is fixed to a slide rod seat and a slide rod bracket. The slide rod seat and the slide rod bracket are fixed to the outer wall of the housing. The clamping assembly includes a first clamping assembly and a second clamping assembly; the first clamping assembly is arranged along the X direction, and the second clamping assembly is arranged along the Y direction; the first clamping assembly is composed of a pair of first clamping claws and a pair of first adjusting knobs, and the first adjusting knobs adjust the height of the first clamping claws; The second clamping assembly is composed of second claws arranged in pairs, each second claw is sleeved on its corresponding second claw slide, and the second claw is connected to the second adjusting knob through a transmission structure, and the second claw can be adjusted to move up and down along the second claw slide by rotating the second adjusting knob; the two second claw slides are installed at both ends of the telescopic rod, and the telescopic rod is installed in the channel processed on the side of the mobile clamping platform; a spring is sleeved on the telescopic rod, and the spring is located between the side of the mobile clamping platform and the inner wall of the second claw slide; a telescopic mechanism is also provided between the inner end faces of the mobile clamping platform.

2. The ultrasonic vibration and powder collection platform for laser additive manufacturing according to claim 1, characterized in that: The powder blocking mechanism consists of a powder blocking plate, a clockwork spring and a Teflon film. The two powder blocking plates are mounted on two support rods and can slide relative to the support rods. The clockwork spring is fixed on one of the powder blocking plates. The Teflon film is wrapped around the clockwork spring, and the end of the Teflon film is fixed to the other powder blocking plate.

3. The ultrasonic vibration and powder collection platform for laser additive manufacturing according to claim 1, characterized in that: The ultrasonic vibration mechanism consists of an ultrasonic transducer, a support plate, a support platform, a vibration damping pedestal and an ultrasonic vibration platform. The ultrasonic transducer is installed on the vertical support plate and connected to the ultrasonic generator. The support plate is fixed on the support platform, and the support platform is fixed to the servo double-rod hydraulic cylinder body by a snap. The support platform is also equipped with a vibration damping pedestal. The ultrasonic vibration platform is installed above the vibration damping pedestal, and the bottom of the ultrasonic vibration platform is in contact with the output end of the ultrasonic transducer.

4. The ultrasonic vibration and powder collection platform for laser additive manufacturing according to claim 1, wherein: The powder screening and collecting device includes a cover plate and a waste powder conveying and screening mechanism. The waste powder conveying and screening mechanism consists of a partition, a conveyor belt, a mobile funnel, a funnel drive assembly, a powder screening mechanism, a powder screening drive assembly and a support frame. The partition is installed between the cover plate and the conveyor belt support frame. The inner wall of the partition parallel to the moving direction of the conveyor belt is smoothed. The partition is integrally connected with a closing baffle above the tail end of the conveyor belt. A mobile funnel is set at the tail end of the conveyor belt. The mobile funnel is driven by the funnel drive assembly to move along the direction of the powder screening mechanism. The powder screening mechanism is driven by the powder screening drive assembly.

5. The ultrasonic vibration and powder collection platform for laser additive manufacturing according to claim 4, characterized in that: The powder screening mechanism consists of a partition plate, a coarse particle powder collection box, a fine particle powder collection box, a universal rolling ball and an inclined panel. The inclined panel is divided into multiple parts by the partition plate, which correspond to the waste powder screening areas of different materials respectively. The upper half of the inclined panel is processed with fine sieve holes, and the fine particle powder collection box is installed below the inclined panel with fine sieve holes. The lower half of the inclined panel is processed with coarse sieve holes, and the coarse particle powder collection box is installed below the inclined panel with coarse sieve holes. A universal rolling ball is movably connected below the powder collection box to support the powder collection box, and the universal rolling ball is embedded in the bottom plate of the waste powder collection device shell.

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