An additive powder laying device with automatic tool changing, cooling and vibration flattening functions

Abstract

An additive powder laying device with automatic tool changing, cooling and vibration leveling functions, the powder laying slide is arranged in the middle of the printer body; the powder supply groove and the printing groove are arranged side by side at the bottom of the printer body, and the laser printing head is located above the printing groove; the automatic tool changing mechanism and the powder layer vibration leveling mechanism are arranged on the powder laying slide, and the scraper is arranged on the automatic tool changing mechanism; the molten pool cooling mechanism is arranged between the automatic tool changing mechanism and the printer body. Through the automatic tool changing mode, the problem of complicated manual tool changing operation is avoided, and the position accuracy of the scraper before and after tool changing is greatly improved; through the non-contact water cooling mode, the molten pool temperature is reduced through the synergistic effect of heat radiation and air heat conduction, the disturbance to the metal powder during the cooling process is avoided, and the additive manufacturing quality of the subsequent parts is improved; through the independently moving powder layer vibration leveling mode, the powder layer flatness and the loose packing density are improved, the disturbance to the laid powder layer is reduced, and the additive manufacturing quality of the subsequent parts is improved.

Description

Technical Field

[0001] This invention belongs to the field of selective laser melting metal additive manufacturing technology, and in particular relates to an additive powder spreading device with automatic tool changing, cooling and vibration leveling functions. Background Technology

[0002] Since selective laser melting (SLM) technology manufactures metal parts through layer-by-layer powder spreading and selective laser melting, the performance of the powder spreading system directly affects the part forming quality and production efficiency. However, the powder spreading devices used in existing SLM technology still have the following shortcomings.

[0003] ① Because the scraper will wear down after long-term use, and different powders require scrapers with different structures, the traditional method requires the equipment to be stopped for manual scraper replacement. This is not only cumbersome, but also makes it difficult to accurately ensure the consistency of the scraper installation accuracy before and after the replacement.

[0004] ② The temperature of the molten pool formed after the metal powder is melted by laser is extremely high, and the natural cooling rate is slow. The waiting process for cooling not only reduces printing efficiency but may also cause thermal stress deformation in the formed area. For equipment equipped with cooling functions, forced air cooling is generally used. However, forced air cooling is prone to causing strong disturbance to the metal powder, thereby affecting the quality of subsequent additive manufacturing of parts.

[0005] ③ The powder layer after being scraped with a scraper often exhibits morphological defects such as particle accumulation, bridging, and grooves. This not only results in low loose density but also easily leads to quality defects such as porosity and cracks inside the sintered parts. For equipment equipped with auxiliary vibration functions, the overall vibration of the powder bed is commonly used. Although this can increase the loose density of the powder layer, it also increases the overall disturbance to the already laid powder layer, which can adversely affect the quality of subsequent additive manufacturing of parts. Summary of the Invention

[0006] To address the problems of existing technologies, this invention provides an additive powder laying device with automatic tool changing, cooling, and vibration leveling functions, achieving integrated coupling of these functions. The automatic tool changing method avoids the cumbersome operation of manual tool changing and significantly improves the positional accuracy of the scraper before and after tool changing. The non-contact water cooling method, through the combined effect of thermal radiation and air conduction, reduces the temperature of the molten pool, preventing disturbance to the metal powder during cooling and improving the quality of subsequent additive manufacturing of parts. The independently moving powder layer vibration leveling method improves the flatness and loose packing density of the powder layer while reducing disturbance to the already laid powder layer, further facilitating the improvement of the quality of subsequent additive manufacturing of parts.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: an additive manufacturing powder spreading device with automatic tool changing, cooling, and vibration leveling functions, comprising a printer body, a powder spreading slide, a powder supply tank, a printing tank, a scraper, an automatic tool changing mechanism, a melt pool cooling mechanism, and a powder layer vibration leveling mechanism; the powder spreading slide is located in the middle of the printer body and has horizontal sliding freedom relative to the printer body; the powder supply tank and the printing tank are arranged side by side at the bottom of the printer body, and a laser printhead is arranged at the top of the printer body directly above the printing tank; the automatic tool changing mechanism is arranged on the powder spreading slide, and the scraper is arranged on the automatic tool changing mechanism; the melt pool cooling mechanism is arranged between the automatic tool changing mechanism and the printer body; the powder layer vibration leveling mechanism is arranged on the powder spreading slide, and the powder layer vibration leveling mechanism and the melt pool cooling mechanism are respectively located on both sides of the automatic tool changing mechanism.

[0008] The automatic tool changing mechanism includes an automatic tool changing drive motor, an automatic tool changing transmission assembly, an automatic tool changing positioning assembly, and a tool holder; the automatic tool changing drive motor is horizontally fixed on the powder spreading slide; the automatic tool changing transmission assembly is disposed between the motor shaft of the automatic tool changing drive motor and the powder spreading slide; the automatic tool changing positioning assembly is disposed on the automatic tool changing transmission assembly; and the tool holder is disposed on the automatic tool changing positioning assembly.

[0009] The automatic tool changer transmission assembly includes a worm, a worm wheel, and a transmission spindle. The worm is horizontally positioned, with one end coaxially fixed to the motor shaft of the automatic tool changer drive motor, and the other end rotatably connected to the powder spreading slide via a bearing. The transmission spindle is horizontally positioned and perpendicular to the worm, with both ends rotatably connected to the powder spreading slide via bearings. The worm wheel is coaxially fixed to the end of the transmission spindle, and meshes with the worm.

[0010] The automatic tool changer assembly includes a sun gear, planetary gears, a planetary carrier, a shifting wheel, a shifting pin, and a tool holder shaft. The sun gear is coaxially and loosely fitted on the outside of the drive shaft, and is fixedly connected to the powder spreading slide. The planetary carrier is coaxially and fixedly fitted on the drive shaft. The axles of the planetary gears are rotatably connected to the planetary carrier via bearings, and the planetary gears mesh with the sun gear. The shifting wheel is coaxially and fixedly mounted on the axles of the planetary gears. The shifting pin is eccentrically fixedly mounted on the shifting wheel. The tool holder shaft is parallel to the drive shaft and is connected to the drive shaft using an adjustable connection structure. The tool holder is coaxially fitted on the tool holder shaft via bearings, and several scrapers are evenly distributed along the circumference of the tool holder. A shifting groove is provided on the tool holder between any adjacent scrapers, and the shifting groove works in conjunction with the shifting pin. The shifting grooves are evenly distributed along the circumference of the tool holder.

[0011] Adapter pins are fixedly connected to both ends of the tool holder shaft in a direction perpendicular to the tool holder shaft; adapter sleeves are fixedly fitted to both ends of the transmission spindle in a direction perpendicular to the tool transmission spindle; the adapter pins and adapter sleeves are coaxially inserted; an adjusting screw is installed at the axial end of the adapter sleeve; a positioning screw is installed between the radial wall of the adapter sleeve and the adapter pin; and a limit screw is installed between the radial column of the adapter pin and the tool holder.

[0012] The molten pool cooling mechanism includes a radiant water-cooled block, a cooling water inlet hose, a cooling water outlet hose, a self-feeding and retracting assembly for the inlet hose, and a self-feeding and retracting assembly for the outlet hose. The radiant water-cooled block is fixedly installed on the powder-spreading slide. The radiant water-cooled block has a cooling water flow channel inside, and a cooling water inlet and a cooling water outlet are respectively provided on the radiant water-cooled block. One end of the cooling water inlet hose is connected to the cooling water flow channel through the cooling water inlet, and the other end of the cooling water inlet hose is connected to an external cooling water circulation system through the self-feeding and retracting assembly for the inlet hose. One end of the cooling water outlet hose is connected to the cooling water flow channel through the cooling water outlet, and the other end of the cooling water outlet hose is connected to an external cooling water circulation system through the self-feeding and retracting assembly for the outlet hose.

[0013] The inlet hose self-feeding and retracting assembly and the outlet hose self-feeding and retracting assembly have the same structure, both including a drum, lead screw shaft, optical shaft, spline shaft, lead screw nut, coil spring, coil spring housing, spline sleeve, ratchet sleeve, pawl, pawl unlocking motor, and screw connector; the lead screw shaft, optical shaft, and spline shaft are arranged coaxially in sequence and are manufactured as a single unit; the lead screw nut is fixedly installed on the top of the printer body; the lead screw shaft and the lead screw nut are screwed together; the drum is coaxially fitted on the outside of the optical shaft, and the annular cavity between the drum and the optical shaft serves as the cooling water transfer chamber; an outlet hose adapter hole is provided on the drum, and the cooling water inlet hose / cooling water outlet hose is wound on the drum, and the cooling water inlet hose / cooling water outlet hose is connected to the cooling water transfer chamber through the outlet hose adapter hole; both the optical shaft and the spline shaft adopt a hollow shaft structure, and their central... The internal cavity channels are interconnected; several water-permeable holes are provided on the optical axis, and the cooling water transfer cavity is connected to the central cavity channels of the optical axis and the spline shaft through the water-permeable holes; the screw-in connector is fixedly installed at the port of the central cavity channel of the spline shaft, and the screw-in connector is connected to the external cooling water circulation system through a pipeline; the spline sleeve is fitted on the spline shaft; the coil spring housing is coaxially loosely fitted on the outside of the spline sleeve, and the coil spring housing is fixedly connected to the top of the printer body; the coil spring is installed inside the coil spring housing, the outer end of the coil spring is fixedly connected to the coil spring housing, and the inner end of the coil spring is fixedly connected to the spline sleeve; the ratchet sleeve is coaxially fixedly fitted on the outside of the central cavity port side of the spline shaft; the pawl is installed on the top of the printer body, and the pawl engages with the ratchet sleeve; the pawl unlocking motor is installed on the top of the printer body, and the motor shaft of the pawl unlocking motor is coaxially connected to the hinge shaft of the pawl.

[0014] On the powder spreading slide, inlet hose tensioning guide wheels and outlet hose tensioning guide wheels are arranged side by side; the cooling water inlet hose passes through the inlet hose tensioning guide wheel; the cooling water outlet hose passes through the outlet hose tensioning guide wheel.

[0015] The powder layer vibration leveling mechanism includes a vibration leveling mechanism housing, a voice coil motor, a vibration leveling plate, and an elastic rubber adapter post. The vibration leveling mechanism housing is fixedly installed on the powder spreading slide, and the bottom of the vibration leveling mechanism housing is an open structure. The voice coil motor is fixedly installed inside the vibration leveling mechanism housing with its power output shaft facing downward. The vibration leveling plate is horizontally arranged directly below the open bottom of the vibration leveling mechanism housing, and the vibration leveling plate is connected to the vibration leveling mechanism housing through the elastic rubber adapter post.

[0016] The beneficial effects of this invention are: The additive powder laying device of the present invention, which integrates automatic tool changing, cooling, and vibration leveling functions, achieves the integrated coupling of these functions. The automatic tool changing method avoids the cumbersome operation of manual tool changing and significantly improves the positional accuracy of the scraper before and after tool changing. The non-contact water cooling method, through the combined effect of thermal radiation and air conduction, reduces the temperature of the molten pool, preventing disturbance to the metal powder during cooling and improving the quality of subsequent additive manufacturing of parts. The independently moving powder layer vibration leveling method improves the flatness and loose packing density of the powder layer while reducing disturbance to the already laid powder layer, further facilitating the improvement of the quality of subsequent additive manufacturing of parts. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of an additive powder spreading device with automatic tool changing, cooling and vibration leveling functions according to the present invention. Figure 2 This is a schematic diagram of the automatic tool changing mechanism of the present invention (viewpoint 1). Figure 3 This is a schematic diagram of the automatic tool changing mechanism of the present invention (viewpoint 2). Figure 4 This is a partial structural schematic diagram of the automatic tool changing mechanism of the present invention (viewpoint three); Figure 5 This is a schematic diagram of the molten pool cooling mechanism of the present invention; Figure 6 This is a schematic diagram of the structure of the self-feeding and retracting assembly of the water inlet hose of the present invention (viewpoint 1). Figure 7 This is a partial structural schematic diagram of the self-feeding and retracting assembly of the water inlet hose of the present invention (view 2, cross-sectional view); Figure 8 This is a schematic diagram of the powder layer vibration leveling mechanism of the present invention; In the diagram, 1—Printer body, 2—Toner spreading slide, 3—Toner supply tank, 4—Printing tank, 5—Scraper, 6—Automatic blade changer, 7—Molten pool cooling mechanism, 8—Powder layer vibration leveling mechanism, 9—Laser printhead, 10—Automatic blade changer drive motor, 11—Blade holder, 12—Worm gear, 13—Worm wheel, 14—Drive spindle, 15—Sun gear, 16—Planet gears, 17—Planet carrier, 18—Shifting wheel, 19—Shifting pin, 20—Blade holder shaft, 21—Shifting slot, 22—Adapter post, 23—Adapter sleeve, 24—Adjusting screw, 25—Positioning screw, 26—Limit screw, 27—Radiation water cooling block, 28—Cooling water inlet hose, 29—Cooling water outlet... 30—Inlet hose self-feeding and retracting assembly; 31—Outlet hose self-feeding and retracting assembly; 32—Cooling water inlet; 33—Cooling water outlet; 34—Drum; 35—Lead screw shaft; 36—Optical shaft; 37—Spline shaft; 38—Lead screw nut; 39—Coil spring; 40—Coil spring housing; 41—Spline sleeve; 42—Ratchet sleeve; 43—Pawl; 44—Pawl unlocking motor; 45—Screw connector; 46—Cooling water transfer chamber; 47—Outlet hose adapter hole; 48—Water permeable hole; 49—Vibration leveling mechanism housing; 50—Voice coil motor; 51—Vibration leveling plate; 52—Elastic rubber adapter post; 53—Inlet hose tensioning guide wheel; 54—Outlet hose tensioning guide wheel. Detailed Implementation

[0018] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0019] like Figures 1 to 8 As shown, an additive manufacturing powder spreading device with automatic blade changing, cooling, and vibration leveling functions includes a printer body 1, a powder spreading slide 2, a powder supply tank 3, a printing tank 4, a scraper 5, an automatic blade changing mechanism 6, a melt pool cooling mechanism 7, and a powder layer vibration leveling mechanism 8. The powder spreading slide 2 is located in the middle of the printer body 1 and has horizontal sliding freedom relative to the printer body 1. The powder supply tank 3 and the printing tank 4 are arranged side by side at the bottom of the printer body 1, and a laser printhead 9 is arranged at the top of the printer body 1 directly above the printing tank 4. The automatic blade changing mechanism 6 is arranged on the powder spreading slide 2, and the scraper 5 is arranged on the automatic blade changing mechanism 6. The melt pool cooling mechanism 7 is arranged between the automatic blade changing mechanism 6 and the printer body 1. The powder layer vibration leveling mechanism 8 is arranged on the powder spreading slide 2, and the powder layer vibration leveling mechanism 8 and the melt pool cooling mechanism 7 are located on both sides of the automatic blade changing mechanism 6.

[0020] The automatic tool changing mechanism 6 includes an automatic tool changing drive motor 10, an automatic tool changing transmission assembly, an automatic tool changing positioning assembly, and a tool holder 11; the automatic tool changing drive motor 10 is horizontally fixed on the powder spreading slide 2; the automatic tool changing transmission assembly is disposed between the motor shaft of the automatic tool changing drive motor 10 and the powder spreading slide 2; the automatic tool changing positioning assembly is disposed on the automatic tool changing transmission assembly; and the tool holder 11 is disposed on the automatic tool changing positioning assembly.

[0021] The automatic tool changer transmission assembly includes a worm gear 12, a worm wheel 13, and a transmission spindle 14. The worm gear 12 is horizontally arranged, with one end coaxially fixed to the motor shaft of the automatic tool changer drive motor 10, and the other end rotatably connected to the powder spreading slide 2 via a bearing. The transmission spindle 14 is horizontally arranged and perpendicularly distributed to the worm gear 12, with both ends rotatably connected to the powder spreading slide 2 via bearings. The worm wheel 13 is coaxially fixed to the end of the transmission spindle 14, and meshes with the worm gear 12.

[0022] The automatic tool changer assembly includes a sun gear 15, planet gears 16, a planet carrier 17, a shifting wheel 18, a shifting pin 19, and a tool holder shaft 20. The sun gear 15 is coaxially loosely fitted on the outside of the drive spindle 14 and is fixedly connected to the powder spreading slide 2. The planet carrier 17 is coaxially fixedly fitted on the drive spindle 14. The axles of the planet gears 16 are rotatably connected to the planet carrier 17 via bearings, and the planet gears 16 mesh with the sun gear 15. The shifting wheel 18 is coaxially fixedly mounted on the axles of the planet gears 16. The shift pin 19 is eccentrically fixed on the shift wheel 18; the tool holder shaft 20 is parallel to the transmission main shaft 14, and the tool holder shaft 20 is connected to the transmission main shaft 14 by an adjustable connection structure; the tool holder 11 is coaxially mounted on the tool holder shaft 20 through bearings, and a plurality of scrapers 5 are evenly distributed along the circumference of the tool holder 11. A shift groove 21 is provided on the tool holder 11 between any adjacent scrapers 5, and the shift groove 21 is used in conjunction with the shift pin 19; the shift groove 21 is evenly distributed along the circumference of the tool holder 11.

[0023] Adapter pins 22 are fixedly connected to both ends of the tool holder shaft 20 in a direction perpendicular to the tool holder shaft 20; adapter sleeves 23 are fixedly fitted to both ends of the transmission main shaft 14 in a direction perpendicular to the tool transmission main shaft 14; the adapter pins 22 and the adapter sleeves 23 are coaxially inserted and fitted; an adjusting screw 24 is installed at the axial end of the adapter sleeve 23; a positioning screw 25 is installed between the radial wall of the adapter sleeve 23 and the adapter pin 22; and a limiting screw 26 is installed between the radial column of the adapter pin 22 and the tool holder 11.

[0024] The molten pool cooling mechanism 7 includes a radiant water-cooled block 27, a cooling water inlet hose 28, a cooling water outlet hose 29, an inlet hose self-feeding and retracting assembly 30, and an outlet hose self-feeding and retracting assembly 31. The radiant water-cooled block 27 is fixedly installed on the powder spreading slide 2. The radiant water-cooled block 27 has a cooling water flow channel inside, and a cooling water inlet 32 ​​and a cooling water outlet 33 are respectively provided on the radiant water-cooled block 27. One end of the cooling water inlet hose 28 is connected to the cooling water flow channel through the cooling water inlet 32, and the other end of the cooling water inlet hose 28 is connected to the external cooling water circulation system through the inlet hose self-feeding and retracting assembly 30. One end of the cooling water outlet hose 29 is connected to the cooling water flow channel through the cooling water outlet 33, and the other end of the cooling water outlet hose 29 is connected to the external cooling water circulation system through the outlet hose self-feeding and retracting assembly 31.

[0025] The inlet hose self-feeding and retracting assembly 30 and the outlet hose self-feeding and retracting assembly 31 have the same structure, both including a drum 34, a lead screw shaft 35, a light shaft 36, a spline shaft 37, a lead screw nut 38, a coil spring 39, a coil spring housing 40, a spline sleeve 41, a ratchet sleeve 42, a pawl 43, a pawl unlocking motor 44, and a screw connector 45; the lead screw shaft 35, the light shaft 36, and the spline shaft 37 are arranged coaxially in sequence and the three adopt an integrated manufacturing structure; the lead screw nut 38 is fixedly installed on the top of the printer body 1; the lead screw shaft 35 is screwed into the nut 38; the drum 34 is coaxially mounted on the outside of the optical shaft 36, and the annular cavity between the drum 34 and the optical shaft 36 serves as the cooling water transfer chamber 46; a water outlet hose adapter hole 47 is provided on the drum 34, and the cooling water inlet hose 28 / cooling water outlet hose 29 is wound on the drum 34, and the cooling water inlet hose 28 / cooling water outlet hose 29 is connected to the cooling water transfer chamber 46 through the water outlet hose adapter hole 47; both the optical shaft 36 and the spline shaft 37 are hollow shafts. The structure is such that the central cavities of the two are interconnected; several water-permeable holes 48 are provided on the optical axis 36, and the cooling water transfer cavity 46 is connected to the central cavities of the optical axis 36 and the spline shaft 37 through the water-permeable holes 48; the screw connector 45 is fixedly installed at the port of the central cavity of the spline shaft 37, and the screw connector 45 is connected to the external cooling water circulation system through a pipeline; the spline sleeve 41 is fitted onto the spline shaft 37; the coil spring shell 40 is coaxially loosely fitted on the outside of the spline sleeve 41, and the coil spring shell 40 is connected to the printer body 1. The top is fixedly connected; the coil spring 39 is installed inside the coil spring housing 40, the outer end of the coil spring 39 is fixedly connected to the coil spring housing 40, and the inner end of the coil spring 39 is fixedly connected to the spline sleeve 41; the ratchet sleeve 42 is coaxially fixedly fitted on the outside of the central cavity port side of the spline shaft 37; the pawl 43 is installed on the top of the printer body 1, and the pawl 43 meshes with the ratchet sleeve 42; the pawl unlocking motor 44 is installed on the top of the printer body 1, and the motor shaft of the pawl unlocking motor 44 is coaxially connected to the hinge shaft of the pawl 43.

[0026] On the powder spreading slide 2, inlet hose tensioning guide wheel 53 and outlet hose tensioning guide wheel 54 are arranged side by side; the cooling water inlet hose 28 passes through inlet hose tensioning guide wheel 53; the cooling water outlet hose 29 passes through outlet hose tensioning guide wheel 54.

[0027] The powder layer vibration leveling mechanism 8 includes a vibration leveling mechanism housing 49, a voice coil motor 50, a vibration leveling plate 51, and an elastic rubber adapter post 52. The vibration leveling mechanism housing 49 is fixedly installed on the powder spreading slide 2, and the bottom of the vibration leveling mechanism housing 49 is an open structure. The voice coil motor 50 is fixedly installed inside the vibration leveling mechanism housing 49 with its power output shaft facing downward. The vibration leveling plate 51 is horizontally arranged directly below the open bottom of the vibration leveling mechanism housing 49, and the vibration leveling plate 51 is connected to the vibration leveling mechanism housing 49 through the elastic rubber adapter post 52.

[0028] The following describes a single use of the present invention with reference to the accompanying drawings: In this embodiment, six scrapers 5 are evenly distributed along the circumference of the blade holder 11, and six corresponding repositioning slots 21 are provided. Before printing, a scraper 5 with the corresponding structure is selected according to the type of metal powder in the toner supply tank 3, so that the selected scraper 5 is at the bottom of the blade holder 11. During toner spreading, the toner spreading slide 2 passes over the toner supply tank 3 and the printing tank 4 in sequence, and the scraper 5 at the bottom of the blade holder 11 scrapes the uppermost layer of metal powder in the toner supply tank 3 into the printing tank 4.

[0029] During the powder spreading process in the printing tank 4, the molten pool cooling mechanism 7 and the powder layer vibration leveling mechanism 8 are simultaneously activated. The molten pool cooling mechanism 7 first moves above the printing tank 4 to accelerate the cooling of the unpowder-spread molten pool. Then, the scraper 5 scrapes the metal powder into the cooled molten pool 4. Finally, the powder layer vibration leveling mechanism 8 moves above the printing tank 4 to perform final vibration leveling on the spread powder layer. Once the powder layer has been completely vibrated and leveled, the laser print head 9 is activated, and laser printing can then be performed on the metal powder that has been spread and leveled on the upper surface of the printing tank 4 according to the set program.

[0030] During the operation of the powder layer vibration leveling mechanism 8, the excitation force output by the voice coil motor 50 is synchronously transmitted to the vibration leveling plate 51. The vibration leveling plate 51 vibrates and levels the surface of the powder layer scraped by the scraper 5, effectively eliminating possible morphological defects such as accumulation, bridging, and grooves in the powder layer. Moreover, the vibration force output by the vibration leveling plate 51 only acts on the powder layer surface in contact with it, and will not interfere with the powder layer that has already been laid and leveled.

[0031] During the operation of the molten pool cooling mechanism 7, cooling water sequentially flows through the screw joint 45 of the inlet hose self-feeding and retracting assembly 30, the central cavity of the spline shaft 37 and the optical shaft 36, the water permeation hole 48 of the optical shaft 36, the cooling water rotating cavity 46, the outlet hose adapter hole 47, and the cooling water inlet hose 28 into the radiant water-cooled block 27. Then, it sequentially flows through the cooling water outlet hose 29, the outlet hose adapter hole 47 of the outlet hose self-feeding and retracting assembly 31, the cooling water rotating cavity 46, the water permeation hole 48 of the optical shaft 36, and the optical shaft 36... The central cavity of the spline shaft 37 and the rotary joint 45 return to the cooling water circulation system, so that the radiant water-cooled block 27 is always kept at the set low temperature. The lower surface of the radiant water-cooled block 27 does not directly contact the surface of the powder layer, and there is an air gap between them. The heat of the molten pool of the powder layer is efficiently absorbed by the radiant water-cooled block 27 in the form of thermal radiation. At the same time, the air layer will also transfer the heat of the molten pool to the radiant water-cooled block 27 in the form of thermal conduction. Through this non-contact cooling method, interference with the powder layer is effectively avoided.

[0032] As the radiant water-cooled block 27 moves synchronously with the powder-spreading slide 2, it will simultaneously pull on the cooling water inlet hose 28 and the cooling water outlet hose 29. Under the action of the pulling force, the drum 34 rotates, thereby releasing the cooling water inlet hose 28 and the cooling water outlet hose 29.

[0033] During the forward rotation of the drum 34, the optical shaft 36, the lead screw shaft 35, and the spline shaft 37 will rotate synchronously. As the lead screw shaft 35 rotates, since the lead screw nut 38 is fixed, the rotational motion of the lead screw shaft 35 will be synchronously converted into axial movement, thereby causing the optical shaft 36, the spline shaft 37, and the drum 34 to move axially synchronously. Since the cooling water inlet hose 28 and the cooling water outlet hose 29 are released in a spiral winding state on the drum 34, the axial movement of the drum 34 can achieve a relatively constant release position of the cooling water inlet hose 28 and the cooling water outlet hose 29.

[0034] During the forward rotation of the spline shaft 37, the ratchet sleeve 42 rotates synchronously with the spline shaft 37. At this time, the pawl 43 can pass over the ratchet sleeve 42 in one direction without obstructing it. However, when rotating in the reverse direction, it will obstruct the ratchet sleeve 42. Simultaneously, the inner end of the coil spring 39 rotates synchronously with the spline sleeve 41 and the spline shaft 37, allowing the coil spring 39 to accumulate spring force.

[0035] After the powder is spread, when the powder spreading slide 2 moves back, the pulling force of the cooling water inlet hose 28 and the cooling water outlet hose 29 disappears. At this time, the pawl unlocking motor 44 starts, controlling the pawl 43 to disengage from the ratchet sleeve 42. The ratchet sleeve 42 is no longer blocked by the pawl 43. As the spring force of the coil spring 39 is released, it will drive the spline sleeve 41, spline shaft 37, optical shaft 36, lead screw shaft 35, drum 34 and ratchet sleeve 42 to rotate synchronously in the opposite direction.

[0036] During the reverse rotation of the optical axis 36, the drum 34 rotates synchronously, thereby causing the cooling water inlet hose 28 and cooling water outlet hose 29 to rewind back onto the drum 34, achieving the recovery of the cooling water inlet hose 28 and cooling water outlet hose 29. Simultaneously, as the lead screw shaft 35 rotates in the reverse direction, its rotational motion is converted into a reverse axial movement, driving the optical axis 36, spline shaft 37, and drum 34 to move in the opposite direction. Since the cooling water inlet hose 28 and cooling water outlet hose 29 are spirally wound and recovered on the drum 34, the reverse axial movement of the drum 34 ensures a relatively constant recovery position for the cooling water inlet hose 28 and cooling water outlet hose 29.

[0037] During the release and retraction of the cooling water inlet hose 28 and the cooling water outlet hose 29, the presence of the inlet hose tension guide wheel 53 and the outlet hose tension guide wheel 54 ensures that the cooling water inlet hose 28 and the cooling water outlet hose 29 are always taut and their routing positions are relatively constant, thus preventing the cooling water inlet hose 28 and the cooling water outlet hose 29 from becoming tangled or interfering with other moving parts due to slack.

[0038] When the scraper 5 needs to be replaced, the automatic tool changer drive motor 10 is first started, which drives the worm gear 12 to rotate, which in turn drives the worm wheel 13 meshing with it to rotate, and simultaneously drives the transmission spindle 14 to rotate. During the rotation of the transmission spindle 14, the planetary carrier 17 will rotate on its own axis, and the tool holder shaft 20 will revolve around the sun, while the planetary gear 16 will also revolve around the sun.

[0039] As the tool post shaft 20 revolves, it drives the tool post 11 to revolve synchronously, so that the tool post 11 returns to its original position after one revolution. At the same time, during the revolution of the planetary gear 16, since the planetary gear 16 is meshed with the fixed sun gear 15, the planetary gear 16 achieves synchronous rotation during its revolution, and after one revolution of the planetary gear 16, the planetary gear 16 also completes one rotation.

[0040] During one rotation of the planetary gear 16, the shifting wheel 18 rotates synchronously, causing the shifting pin 19 to revolve around the center of the shifting wheel 18. Simultaneously, during the revolution of the shifting pin 19, in this embodiment, the phase angle range of the engagement between the shifting pin 19 and the shifting slot 21 on the tool holder 11 is 60°. Therefore, each revolution of the shifting pin 19 rotates the tool holder 11 by 60°, which perfectly achieves the sequential shifting of the six scrapers 5 on the tool holder 11.

[0041] In summary, for every rotation of the planetary carrier 17, the planetary gear 16 revolves once around the sun, while the planetary gear 16 itself rotates once, thus causing the tool holder 11 to rotate 60°, ultimately achieving automatic tool changing. It should be noted that the number of scrapers 5 and the number of shifting slots 21 on the tool holder 11 can be adjusted and set according to actual needs.

[0042] Before changing the position of scraper 5, loosen the limit screw 26 to release the limit between tool holder 11 and adapter column 22, so that tool holder 11 can regain the degree of rotational freedom on tool holder shaft 20.

[0043] After the scraper 5 has finished changing position, first loosen the positioning screw 25 to release the limiting position between the adapter sleeve 23 and the adapter post 22. Then, tighten the adjusting screw 24 to adjust the insertion depth of the adapter post 22 within the adapter sleeve 23, thereby adjusting the distance between the scraper 5 and the powder layer surface. After that, tighten the positioning screw 25 to restore the limiting position between the adapter sleeve 23 and the adapter post 22. Finally, retighten the limiting screw 26 to restore the limiting position between the tool holder 11 and the adapter post 22.

[0044] The solutions in the embodiments are not intended to limit the scope of protection of the present invention. All equivalent implementations or modifications that do not depart from the present invention are included in the scope of protection of the present invention.

Claims

1. An additive powder spreading device with automatic tool changing, cooling and vibration flattening functions, characterized in that: The printer includes a printer body, a toner spreading slide, a toner supply trough, a printing trough, a scraper, an automatic tool changer, a melt pool cooling mechanism, and a powder layer vibration leveling mechanism. The toner spreading slide is located in the middle of the printer body and has horizontal sliding freedom relative to the printer body. The toner supply trough and the printing trough are arranged side by side at the bottom of the printer body, and a laser printhead is located at the top of the printer body directly above the printing trough. The automatic tool changer is located on the toner spreading slide, and the scraper is located on the automatic tool changer. The melt pool cooling mechanism is located between the automatic tool changer and the printer body. The powder layer vibration leveling mechanism is located on the toner spreading slide, and the powder layer vibration leveling mechanism and the melt pool cooling mechanism are located on opposite sides of the automatic tool changer.

2. The additive powder spreading device with automatic tool changing, cooling and vibration leveling functions according to claim 1, characterized in that: The automatic tool changing mechanism includes an automatic tool changing drive motor, an automatic tool changing transmission assembly, an automatic tool changing positioning assembly, and a tool holder; the automatic tool changing drive motor is horizontally fixed on the powder spreading slide; the automatic tool changing transmission assembly is disposed between the motor shaft of the automatic tool changing drive motor and the powder spreading slide; the automatic tool changing positioning assembly is disposed on the automatic tool changing transmission assembly; and the tool holder is disposed on the automatic tool changing positioning assembly.

3. The powder spreading device with automatic tool changing, cooling and vibration leveling functions according to claim 2, characterized in that: The automatic tool changer transmission assembly includes a worm, a worm wheel, and a transmission spindle. The worm is horizontally positioned, with one end coaxially fixed to the motor shaft of the automatic tool changer drive motor, and the other end rotatably connected to the powder spreading slide via a bearing. The transmission spindle is horizontally positioned and perpendicular to the worm, with both ends rotatably connected to the powder spreading slide via bearings. The worm wheel is coaxially fixed to the end of the transmission spindle, and meshes with the worm.

4. The additive powder spreading device with automatic tool changing, cooling and vibration leveling functions according to claim 3, characterized in that: The automatic tool changer assembly includes a sun gear, planetary gears, a planetary carrier, a shifting wheel, a shifting pin, and a tool holder shaft. The sun gear is coaxially and loosely fitted on the outside of the drive shaft, and is fixedly connected to the powder spreading slide. The planetary carrier is coaxially and fixedly fitted on the drive shaft. The axles of the planetary gears are rotatably connected to the planetary carrier via bearings, and the planetary gears mesh with the sun gear. The shifting wheel is coaxially and fixedly mounted on the axles of the planetary gears. The shifting pin is eccentrically fixedly mounted on the shifting wheel. The tool holder shaft is parallel to the drive shaft and is connected to the drive shaft using an adjustable connection structure. The tool holder is coaxially fitted on the tool holder shaft via bearings, and several scrapers are evenly distributed along the circumference of the tool holder. A shifting groove is provided on the tool holder between any adjacent scrapers, and the shifting groove works in conjunction with the shifting pin. The shifting grooves are evenly distributed along the circumference of the tool holder.

5. The additive powder spreading device with automatic tool changing, cooling and vibration leveling functions according to claim 4, characterized in that: Adapter pins are fixedly connected to both ends of the tool holder shaft in a direction perpendicular to the tool holder shaft; adapter sleeves are fixedly fitted to both ends of the transmission spindle in a direction perpendicular to the tool transmission spindle; the adapter pins and adapter sleeves are coaxially inserted; an adjusting screw is installed at the axial end of the adapter sleeve; a positioning screw is installed between the radial wall of the adapter sleeve and the adapter pin; and a limit screw is installed between the radial column of the adapter pin and the tool holder.

6. The additive powder spreading device with automatic tool changing, cooling and vibration leveling functions according to claim 1, characterized in that: The molten pool cooling mechanism includes a radiant water-cooled block, a cooling water inlet hose, a cooling water outlet hose, a self-feeding and retracting assembly for the inlet hose, and a self-feeding and retracting assembly for the outlet hose. The radiant water-cooled block is fixedly installed on the powder-spreading slide. The radiant water-cooled block has a cooling water flow channel inside, and a cooling water inlet and a cooling water outlet are respectively provided on the radiant water-cooled block. One end of the cooling water inlet hose is connected to the cooling water flow channel through the cooling water inlet, and the other end of the cooling water inlet hose is connected to an external cooling water circulation system through the self-feeding and retracting assembly for the inlet hose. One end of the cooling water outlet hose is connected to the cooling water flow channel through the cooling water outlet, and the other end of the cooling water outlet hose is connected to an external cooling water circulation system through the self-feeding and retracting assembly for the outlet hose.

7. The additive powder spreading device with automatic tool changing, cooling and vibration leveling functions according to claim 6, characterized in that: The inlet hose self-feeding and retracting assembly and the outlet hose self-feeding and retracting assembly have the same structure, both including a drum, lead screw shaft, optical shaft, spline shaft, lead screw nut, coil spring, coil spring housing, spline sleeve, ratchet sleeve, pawl, pawl unlocking motor, and screw connector; the lead screw shaft, optical shaft, and spline shaft are arranged coaxially in sequence and are manufactured as a single unit; the lead screw nut is fixedly installed on the top of the printer body; the lead screw shaft and the lead screw nut are screwed together; the drum is coaxially fitted on the outside of the optical shaft, and the annular cavity between the drum and the optical shaft serves as the cooling water transfer chamber; an outlet hose adapter hole is provided on the drum, and the cooling water inlet hose / cooling water outlet hose is wound on the drum, and the cooling water inlet hose / cooling water outlet hose is connected to the cooling water transfer chamber through the outlet hose adapter hole; both the optical shaft and the spline shaft adopt a hollow shaft structure, and their central... The internal cavity channels are interconnected; several water-permeable holes are provided on the optical axis, and the cooling water transfer cavity is connected to the central cavity channels of the optical axis and the spline shaft through the water-permeable holes; the screw-in connector is fixedly installed at the port of the central cavity channel of the spline shaft, and the screw-in connector is connected to the external cooling water circulation system through a pipeline; the spline sleeve is fitted on the spline shaft; the coil spring housing is coaxially loosely fitted on the outside of the spline sleeve, and the coil spring housing is fixedly connected to the top of the printer body; the coil spring is installed inside the coil spring housing, the outer end of the coil spring is fixedly connected to the coil spring housing, and the inner end of the coil spring is fixedly connected to the spline sleeve; the ratchet sleeve is coaxially fixedly fitted on the outside of the central cavity port side of the spline shaft; the pawl is installed on the top of the printer body, and the pawl engages with the ratchet sleeve; the pawl unlocking motor is installed on the top of the printer body, and the motor shaft of the pawl unlocking motor is coaxially connected to the hinge shaft of the pawl.

8. The additive powder spreading device with automatic tool changing, cooling and vibration leveling functions according to claim 6, characterized in that: On the powder spreading slide, inlet hose tensioning guide wheels and outlet hose tensioning guide wheels are arranged side by side; the cooling water inlet hose passes through the inlet hose tensioning guide wheel; the cooling water outlet hose passes through the outlet hose tensioning guide wheel.

9. The additive powder spreading device with automatic tool changing, cooling and vibration leveling functions according to claim 1, characterized in that: The powder layer vibration leveling mechanism includes a vibration leveling mechanism housing, a voice coil motor, a vibration leveling plate, and an elastic rubber adapter post. The vibration leveling mechanism housing is fixedly installed on the powder spreading slide, and the bottom of the vibration leveling mechanism housing is an open structure. The voice coil motor is fixedly installed inside the vibration leveling mechanism housing with its power output shaft facing downward. The vibration leveling plate is horizontally arranged directly below the open bottom of the vibration leveling mechanism housing, and the vibration leveling plate is connected to the vibration leveling mechanism housing through the elastic rubber adapter post.

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