Ultrasonic vibration and powder collection platform for laser additive manufacturing

Abstract

The invention discloses an ultrasonic vibration and powder collection platform for laser additive manufacturing. The ultrasonic vibration and powder collection platform aims at solving the problems of hole defects and difficulty in waste powder recovery in the deposition process. The platform comprises a sliding block hinge mechanism, a supporting rod, a powder blocking mechanism, a movable clamping platform, a powder screening and collecting device and an ultrasonic vibration mechanism. The adjustable powder blocking mechanism is arranged on the supporting rod, and the high-temperature-resistant Teflon film is arranged, so that unused powder can be effectively prevented from drifting away and is guided to enter the recycling container, the waste powder recycling efficiency is improved, and mixing of different material powder is avoided. The movable clamping platform adopts a first clamping assembly, a second clamping assembly and a servo double-rod hydraulic cylinder to achieve efficient clamping and stabilization of the base plate, the design of skid resistance and powder residue prevention is achieved, and the clamping stability and the cleanliness of the platform in the deposition process can be guaranteed.

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 laser to quickly melt metal powder, and deposit materials layer by layer to form three-dimensional components by precisely controlling the morphology and temperature of the molten pool. 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] In the LDED process, the deposition path of heterogeneous structural materials usually involves the alternating deposition of multiple different materials to form a layered / voxelized structure with different physical properties. Due to the different deposition paths and material selections, a series of defects often occur during the deposition process, especially the formation of hole defects. The hole defects are mainly caused by the poor discharge of metal vapor, protective gas and other gases during the rapid cooling process of deposition. Specifically, during the laser deposition process, as the materials are stacked layer by layer, the formation of grooves will cause difficulties in the discharge of gas inside the molten pool, thereby generating hole defects. This defect not only affects the mechanical properties of the parts, but also causes the structural instability of the finished product, and even fails to meet the requirements of engineering use; in order to solve this problem, the prior art has enhanced the fluidity of the molten pool by ultrasonic vibration, promoted the discharge of gas, and avoided the formation of holes; see CN119187612A / CN119187611A / CN118926545A, etc.; however, ultrasonic vibration only solves the hole defects. In addition to the hole defects, another challenge in the LDED process is the recycling of powder. Although the unused powder in LDED is basically unreusable due to thermal radiation, the recovery, classification and recycling of waste powder is still a valuable and unresolved technical direction due to the large variety of powder types and large price differences. Especially in the case of dealing with heterogeneous powder additive manufacturing, 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, thus affecting the green sustainability and economy of the manufacturing process. It is urgent to design a clamping platform that helps to recycle 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. Especially in the process of laser additive of heterogeneous powders, the disturbance of powder and gas may cause the position of the additive substrate to change, 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] In addition, in the LDED process, especially in the manufacture of heterogeneous structural materials, waste powder recycling has always been a key issue. Due to the use of a variety of additive powder materials, waste powder and splashing materials that are not completely melted are usually affected by thermal radiation, causing their structure to change and cannot be directly recycled. The recycling prices of different additive powders vary greatly, so the classification and collection of waste powder is 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 solution:

[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 shell is open at the top, and two rectangular holes are respectively arranged on two opposite sides 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 arranged 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 arranged 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 arranged on both sides of the clamping mobile platform, and slide plates are arranged in the rectangular holes, the powder blocking mechanism and the slide plate are both controlled by the support rods, and a powder screening and collecting device is also arranged 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 a connecting rod, and 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, and the slide rod seat and the slide rod bracket are fixedly connected 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 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.

[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 also 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 is composed 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. An 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 is composed 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 arranged 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 on the surface, 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 on the surface, and a coarse particle powder collection box is installed under 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 housing.

[0020] Beneficial effects of the present invention:

[0021] The ultrasonic vibration and powder collection platform for laser additive manufacturing proposed in the present invention can realize the stable clamping and precise positioning of the additive substrate through the mutual cooperation between the slider hinge mechanism, the mobile clamping platform, the support rod, etc.; and by setting the powder blocking mechanism, the waste powder recovery efficiency is improved; and the waste powder of different materials can be recovered through the powder screening and collection device, and the waste powder can be screened while the recovery is achieved. Among them, the ultrasonic vibration device promotes gas discharge, reduces inclusions, avoids the formation of holes by enhancing the fluidity and stability of the molten pool, and improves the density and performance of the additive parts by refining the grains and optimizing the heat distribution. The mobile clamping platform adopts the first and second clamping components and the servo double-rod hydraulic cylinder to achieve efficient clamping and stability of the substrate, and has an anti-slip and anti-powder residue design, which can ensure the clamping stability and platform cleanliness during the deposition process. The waste powder screening and collection device can not only improve the recovery efficiency of waste powder, but also ensure the purity of different powder materials, which meets the requirements of modern additive manufacturing for environmental protection and resource recycling. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the 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 It is a half-section diagram of the ultrasonic vibration clamping platform;

[0028] Figure 7 A top view of the waste powder screening and collecting device;

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

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

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

[0032] In the figure: 1, slider hinge mechanism; 11, limit slide groove; 12, horizontal slider; 13, slide plate; 14, slide bar seat; 15, connecting rod; 16, guide slide bar; 17, hinge; 18, vertical slider; 19, slide bar 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 claw; 412. First adjusting knob; 42. Second clamping assembly; 421. Second clamping claw; 422. Second clamping claw slide plate; 423. Second adjusting knob; 424. Telescopic rod; 425. Spring;

[0036] 5. Telescopic mechanism; 51. Folding frame; 52. Sliding block; 521. Sliding slot; 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. Shell; 71. L-shaped cabinet door; 72. Handle;

[0039] 8. Powder screening and collecting device;

[0040] 81. Cover plate; 811. Housing of waste powder screening and collecting device; 812. Drawer door; 813. Handle; 814. Fixed card slot;

[0041] 82, waste powder conveying and screening mechanism; 821, partition; 8211, closing baffle; 822, conveyor belt; 823, mobile funnel; 8231, powder outlet; 8232, support plate; 8233, slideway; 824, funnel drive assembly; 8241, motor seat; 8242, servo motor; 8243, gear; 8244, spur rack; 825, powder screening mechanism; 8251, partition plate; 8252, coarse screen hole; 8253, Coarse particle powder collecting box; 8254, fine sieve hole; 8255, fine particle powder collecting box; 8256, universal ball; 8257, inclined plate; 826, powder screening drive assembly; 8261, motor seat; 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 as follows in conjunction with 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 introduced above, as well as those described in more detail below, can be implemented in any ultrasonic vibration and powder collection platform in many ways, because the concepts and embodiments disclosed in the present invention are not limited to any embodiment. In addition, some aspects disclosed in the present invention can be used alone or in any appropriate combination with other aspects disclosed in the present invention.

[0044] For laser directed energy deposition of spatial heterogeneous structure materials or heterogeneous powder materials, due to their special deposition path (i.e., first deposit 1, 3, 5 times, then deposit 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, that is, 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 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 make the bonding strength of the added spatial heterogeneous structure material worse and affect its comprehensive performance. In view of 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 effectively eliminate hole defects and improve welding quality.

[0045] In addition, the unused powder ejected by the laser head cannot be directly recycled and reused due to the change of its structure caused by thermal radiation, but 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 the waste additive powder, which is in line with the concept of green and sustainable development. However, the current clamping device. For the existing clamping platform, unused additive powder is easy to accumulate on the surface of the platform instead of falling directly into the recycling container, which increases the difficulty of powder recycling and may also cause powders of different materials to mix with each other, affecting the economic efficiency of recycling; in addition, the ultrasonic vibration clamping device is easy to cause powder to accumulate in the corners and gaps of the clamping platform during the vibration process, which further increases the complexity of cleaning and maintenance. Therefore, it is urgent to design an ultrasonic vibration and powder collection platform that is easy to recycle heterogeneous powders to improve the comprehensive performance of spatial heterogeneous structural materials and the efficiency of heterogeneous powder recycling.

[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 shell 7.

[0047] The housing 7 is a rectangular housing with an open top, and two rectangular holes are respectively provided on two opposite surfaces 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 in each rectangular hole, and a slide plate 13 is provided in 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 oppositely 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 oppositely 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 and the support rod 2 slide synchronously in the horizontal X direction, the slide 13 can close the rectangular hole to prevent the escape of powder during LDED.

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

[0050] Furthermore, a powder blocking mechanism 3 is provided on the support rod 2 inside the housing 7. The powder blocking mechanism 3 includes two powder blocking mechanisms, which are 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 clockwork 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 be manually slid relative to the support rods 2. The clockwork spring 32 is fixed on one of the powder blocking plates 31, and the Teflon film 33 is wound on the clockwork spring 32. The end of the Teflon film 33 is fixed to the other powder blocking plate 31. When the support rod 2 slides away from the YZ plane, the Teflon film 33 is pulled out from the clockwork spring 32. When the support rod 2 slides toward the YZ plane, the Teflon film 33 is pulled out from the clockwork spring 32. When the powder blocking mechanism 3 is in motion, the Teflon film 33 is rewound by the restoring force of the clockwork 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, the position of the powder blocking mechanism 3 on the support rod 2 can be manually adjusted (moved along the Y direction) according to the size of the placed additive substrate. When LDED spatial heterogeneous structure materials are used, unused powder will be blocked by the powder blocking mechanism 3 and fall into the container below, avoiding the dispersion of powder. The arc surface design on the upper part of the support rod 2 is not conducive to the residue of powder. The above design will help to recover waste powder and keep the clamping platform clean.

[0052] Furthermore, a mobile clamping platform 4 is fixedly installed on the middle section of the support rod 2, and a first clamping assembly 41 and two second clamping assemblies 42 are installed on each of the mobile clamping platforms 4. 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 lead screw and nut mechanism (the lead 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 surfaces of the mobile clamping platform 4. Specifically, the telescopic mechanism 5 is composed 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 folding frame 51 are respectively fixed to the slider 52 and the rotating shaft 53, and the two rods of the servo double-rod hydraulic cylinder 54 are fixed on the inner end surface 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 support rod 2 and the mobile clamping platform 4 can move symmetrically. The folding frame 51 moves sideways, the folding frame 51 extends, the slider 52 fixed to one end of the folding frame starts to slide along the slide groove 521, and the rotating shaft 53 connected to the other end rotates a corresponding angle, which ensures the stability of the overall mechanism and prevents 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 a 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, and only a pair of first clamping claws 411 are clamped on both 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 is composed 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 a telescopic rod 424, and the telescopic rod 424 is installed in a 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 add to the side of the substrate, and the second claw 421 is clamped to the side of the additive substrate by the restoring force of the spring 425, and 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 sleeved on the second clamping jaw slide plate 422 (to prevent powder from remaining on the clamping jaw slide plate), 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 residual powder as possible on the entire ultrasonic vibration platform, thereby 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 a servo double-rod hydraulic cylinder 54 by a saddle buckle 541. A vibration reduction base 64 is also mounted on the support platform 63. An ultrasonic vibration platform 65 is mounted above the vibration reduction 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 to work 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, and the ultrasonic vibration is further transmitted 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, and the hole defects are reduced.

[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 plate 81 and a waste powder conveying and screening mechanism 82. Specifically, the waste powder conveying and screening mechanism 82 is composed of a partition plate 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 plate 821 is installed between the cover plate 81 and the conveyor belt support frame 827. The inner wall of the partition plate 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 plate 821 is at the tail 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 driving assembly 824 to move along the slide groove 8233 processed on the support plate 8232; in the present 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 driving assembly 824 is composed of a motor seat 8241, a servo motor 8242, a gear 8243 and a spur rack 8244. The spur rack 8244 is arranged above the mobile funnel 823 and meshes with the gear 8243. The gear 8243 is fixed on the output shaft of the servo motor 8242. The servo motor 8242 is installed in the motor seat 8241. The motor seat 8241 is fixed to the lower side of the cover plate 81 by screws. A powder outlet 8231 is processed 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 surface 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 fine sieve holes 8254. The collecting box 8255, the lower half surface of the inclined plate 8257 is processed with coarse sieve holes 8252, and a coarse particle powder collecting 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 collecting box to support the powder collecting box. The universal ball 8256 is embedded in a hemispherical hole of a suitable size processed on the bottom plate of the waste powder collecting device shell 811. Furthermore, the powder screening mechanism 825 is reciprocatedly driven by the powder screening drive assembly 826 to realize 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 seat 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 seat 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 seat 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 connected to the disc 8264. 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] When LDED spatial heterogeneous structure materials are used, 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 is transported to the tail of the conveyor belt 822, the closing baffle 8211 gathers waste powder A. The gathered waste powder A is guided to the moving funnel 823 via a scraper (not shown in the figure). 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 to start, driving 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 falls into the fine particle powder collection box 8255 through the fine screen hole 8254. 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 moves the powder outlet 8231 to the B powder screening area for subsequent screening work.

[0065] Furthermore, a drawer door 812 and a handle 813 are provided on the housing 811 of the waste powder collecting device, 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 above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An ultrasonic vibration and powder collection platform for laser additive manufacturing, characterized in that: It includes 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 arranged on two opposite sides of the shell, and the two ends of the two support rods are placed on the same horizontal plane and are connected with the slider hinge mechanism after passing through the rectangular holes, and the slider hinge mechanism is arranged 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 arranged on the clamping mobile 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 mobile clamping platform is also equipped with an ultrasonic vibration mechanism; powder blocking mechanisms are arranged on both sides of the clamping mobile platform, and slide plates are arranged in the rectangular holes, and the powder blocking mechanism and the slide plate are both controlled by the support rods; a powder screening and collecting device is also arranged below the shell.

2. The ultrasonic vibration and powder collection platform for laser additive manufacturing according to claim 1, characterized in that: 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 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.

3. 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 wound on the clockwork spring. The end of the Teflon film is fixed to the other powder blocking plate.

4. The ultrasonic vibration and powder collection platform for laser additive manufacturing according to claim 1, characterized in that: The clamping assembly comprises 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.

5. The ultrasonic vibration and powder collection platform for laser additive manufacturing according to claim 4, characterized in that: 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 are used to adjust the height of the first clamping claws.

6. The ultrasonic vibration and powder collection platform for laser additive manufacturing according to claim 4, characterized in that: 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.

7. The ultrasonic vibration and powder collection platform for laser additive manufacturing according to claim 1, characterized in that: A telescopic mechanism is also arranged between the inner end surfaces of the movable clamping platform.

8. The ultrasonic vibration and powder collection platform for laser additive manufacturing according to claim 1, characterized in that: The ultrasonic vibration mechanism is composed 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. The support platform is fixed to the servo double-rod hydraulic cylinder body by a buckle. The support platform is also equipped with a vibration-damping pedestal. An ultrasonic vibration platform is installed above the vibration-damping pedestal, and the ultrasonic vibration platform is in contact with the output end of the ultrasonic transducer at the bottom.

9. The ultrasonic vibration and powder collection platform for laser additive manufacturing according to claim 1, characterized in that: 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 driving assembly, a powder screening mechanism, a powder screening driving 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 rear end of the conveyor belt. A mobile funnel is arranged at the rear end of the conveyor belt. The mobile funnel is driven by the funnel driving assembly to move along the direction of the powder screening mechanism. The powder screening mechanism is driven by the powder screening driving assembly.

10. The ultrasonic vibration and powder collection platform for laser additive manufacturing according to claim 1, 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 respectively correspond to the waste powder screening areas of different materials. The upper half of the inclined panel is processed with fine sieve holes on the surface, and a 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 on the surface, and a 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 housing.

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