A laser additive manufacturing apparatus for metal parts

Abstract

The application belongs to the technical field of laser additive manufacturing, and particularly relates to a laser additive manufacturing device for metal parts, which comprises a laser printer and a printing head installed in the laser printer, and the bottom of the printing head is provided with a nozzle; further comprising a protection mechanism, wherein the protection mechanism comprises a connecting ring attached to the printing head through a screw, the bottom of the connecting ring is fixedly installed with a plurality of connecting rods, the bottom of each connecting rod is fixedly installed with a shield with a narrow upper part and a wide lower part, and the shield is designed as a middle-through type; the connecting ring and the connecting rods of the designed protection mechanism fix the middle-through shield with a narrow upper part and a wide lower part at the bottom of the printing head, cover the nozzle, can effectively block the high-temperature metal droplets and un-melted powder particles splashed in the molten pool, prevent the high-temperature metal droplets and the un-melted powder particles from polluting or burning the optical lens, blocking the powder channel and damaging the sensor, and thus guarantee the stable transmission of laser energy and the powder flow pattern.

Description

Technical Field

[0001] This invention relates to the field of laser additive manufacturing technology, specifically to a laser additive manufacturing device for metal parts. Background Technology

[0002] Laser additive manufacturing equipment for metal parts often refers to laser powder directed energy deposition (EDD) equipment, a crucial branch of the field. Its core characteristic lies in the simultaneous laser heating and powder delivery via a highly integrated coaxial powder-feeding printhead, enabling layer-by-layer deposition or part repair. The printhead works as follows: a fiber laser, after collimation and focusing, is emitted along a central channel, while metal powder, driven by an inert carrier gas (usually argon), is uniformly ejected through annular multi-layered or conical slit nozzles surrounding the laser beam. This ensures the powder flow precisely overlaps with the laser focus in the same molten pool area on the substrate surface. This "light-over-powder" or "powder-over-light" coaxial configuration not only guarantees that powder is always delivered into the molten pool from 360 degrees without dead angles, regardless of the printhead's direction of movement, achieving isotropic deposition quality, but also significantly improves powder utilization (up to 70%–90%), avoiding molten pool obstruction or powder waste caused by the directionality of traditional lateral powder feeding. During operation, the printhead uses a CNC machine tool or industrial robot as a carrier to first form a tiny molten pool on the substrate. Powder enters the molten pool and melts instantly. As the laser beam moves away, the metal quickly solidifies to form a dense deposition channel. By lifting or moving the printhead layer by layer, large metal blanks can be directly manufactured, damaged molds or aero-engine blades can be precisely repaired, and even the gradient transition of dissimilar materials such as titanium alloys and nickel-based alloys can be achieved on a single part.

[0003] In laser powder directed energy deposition (EDA) processing, when a high-energy laser beam melts metal powder to form a molten pool, it produces tiny metal droplets or solid particles known as "spatters." There are two main mechanisms for spatter formation: first, the back pressure of the metal vapor in the molten pool "blows" the liquid metal out of the pool, forming tiny droplets that are ejected outwards; second, incompletely melted powder particles are carried out by vapor or airflow. If these spatter particles land on the optical lenses, nozzles, or external sensors of the printhead, they can contaminate or even burn precision components, leading to laser energy attenuation, powder channel blockage, or monitoring failure. Therefore, a physical protective shield needs to be designed around the printhead for protection. Thus, this paper proposes a laser additive manufacturing device for metal parts to address these issues. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art and solve at least one of the technical problems mentioned in the background art, the present invention proposes a laser additive manufacturing equipment for metal parts.

[0005] The technical solution adopted by the present invention to solve its technical problem is as follows: The laser additive manufacturing equipment for metal parts of the present invention includes a laser printer and a print head installed in the laser printer, wherein a nozzle is provided at the bottom of the print head; it also includes a protective mechanism, wherein the protective mechanism includes a connecting ring attached to the print head by screws, wherein a plurality of connecting rods are fixedly installed at the bottom of the connecting ring, and a protective cover that is narrow at the top and wide at the bottom is fixedly installed at the bottom of the connecting rods, wherein the protective cover has a through-hole design; a storage ring with a through-hole design is provided inside the protective cover, wherein the storage ring also has a narrow top and wide bottom design, and the cross-section of the storage ring is arc-shaped.

[0006] Furthermore, several limiting blocks are fixedly installed on the side wall of the storage ring, and several limiting grooves that are adapted to the limiting blocks are opened inside the protective cover.

[0007] Furthermore, a temperature control mechanism is provided on the connecting ring. The temperature control mechanism includes a storage box fixedly installed on the connecting ring. A miniature water pump and a liquid storage box are fixedly installed inside the storage box. The miniature water pump is equipped with an outlet pipe and a suction pipe that communicate with the inside. One end of the suction pipe is connected to the inside of the liquid storage box. The inside of the protective cover is provided with a placement groove for installing a circulation pipe. One end of the circulation pipe is connected to the outlet pipe, and the other end of the circulation pipe is fixedly installed with a return pipe that communicates with the inside. One end of the return pipe is connected to the inside of the liquid storage box.

[0008] Furthermore, the circulation tube is provided with an agitation assembly, which includes an agitation plate that is fixedly installed inside the circulation tube and is in a twisted shape. The circulation tube is also fixedly installed with a baffle with a through hole.

[0009] Furthermore, a heat exchange assembly is provided inside the liquid storage box, the heat exchange assembly includes several cooling plates installed on the liquid storage box, and several fan blades are installed inside the liquid storage box.

[0010] Furthermore, the protective cover is provided with a liquid spraying mechanism, which includes several cavities opened inside the protective cover. Several connecting pipes corresponding to the cavities are fixedly installed on the surface of the protective cover, and the connecting pipes are connected to a water source.

[0011] Furthermore, a filter screen is fixedly installed at the bottom of the cavity, and a flow guide column with a central through-hole design is fixedly installed at the bottom of the filter screen. The outer surface of the flow guide column has an outward expansion design.

[0012] Furthermore, the interior of the protective cover is provided with a diversion mechanism, which includes a through cavity opened inside the protective cover and connected to the cavity. A closing plate is rotatably connected to the through cavity by a torsion spring. An electromagnetic block and an arc-shaped guide plate are fixedly installed on one side of the closing plate. An electromagnet is fixedly installed inside the cavity.

[0013] Furthermore, an arc-shaped drainage plate is fixedly installed on the inner wall of the cavity.

[0014] Furthermore, an impact mechanism is provided inside the cavity. The impact mechanism includes a slide rod that slides inside the cavity via a spring. An arc-shaped plate is fixedly installed on the top of the slide rod, and several convex balls are fixedly installed on the bottom of the arc-shaped plate.

[0015] The advantages of this invention are: 1. This invention utilizes a designed protective mechanism, with a connecting ring and connecting rod, to fix a narrow-at-the-top, wide-at-the-bottom central shield to the bottom of the printhead, covering the nozzle. This effectively blocks high-temperature molten metal droplets and unmelted powder particles splashing from the molten pool, preventing them from contaminating or burning optical lenses, clogging powder channels, and damaging sensors. This ensures stable laser energy transmission and consistent powder flow morphology. The conical central structure of the shield not only accommodates the diverging powder flow and laser beam below the nozzle but also constrains and guides the localized inert protective gas. The narrow-at-the-top, wide-at-the-bottom channel slows down sudden changes in gas velocity, forming a stable and wider-coverage laminar air curtain around the nozzle outlet. This effectively isolates external air, reduces the oxygen content in the molten pool area, and minimizes oxidation defects. Meanwhile, the arc-shaped collection ring installed inside the protective cover also features a design that is narrower at the top and wider at the bottom, with a central passage. Its arc-shaped inner wall facilitates the guidance of splashes or condensed metal particles to slide down the wall and collect at the bottom of the collection ring, preventing impurities from accumulating on the inner wall of the protective cover and rebounding back into the molten pool or blocking the gas flow channel. The cooperation between the limiting block and the limiting groove allows the collection ring to be quickly installed and removed, facilitating regular cleaning and thus maintaining the protective effect over a long period. The entire mechanism is attached to the print head with screws, resulting in a compact structure that does not affect the original movement flexibility of the print head.

[0016] 2. This invention, through its temperature control mechanism, enables active and uniform temperature regulation of the protective cover, precisely controlling it within the ideal range of 80~150℃. This effectively suppresses cold welding and high-temperature sintering of spatter, significantly reduces the adhesion and accumulation of impurities on the inner wall of the protective cover and the collection ring, extends the cleaning cycle, and makes the curved surface of the collection ring easier to guide impurities to slide down and be collected. Simultaneously, the stable protective cover temperature helps maintain the uniformity of the local inert gas flow field at the nozzle outlet, reduces thermal disturbances affecting the gas curtain, and enhances the anti-oxidation protection effect in the molten pool area. Combined with the previous physical protection structure, active temperature control compensates for the shortcomings of passive shielding in addressing temperature issues. Previously, relying solely on the collection ring to collect spatter could not solve the problem of temperature-induced sintering and adhesion; now, temperature control keeps the protective cover at a "non-stick, non-welding" window temperature, protecting the cover itself and making the disassembly and cleaning of the collection ring more efficient. Furthermore, the integrated design does not increase the external volume of the printhead, ensuring the flexibility of the original protective mechanism.

[0017] 3. The spray mechanism of this invention utilizes a heated water source, which, through the dispersion of the filter screen and the outward expansion of the guide column, achieves uniform spraying of the molded parts and the inner wall of the protective cover. The warm liquid efficiently dissolves oil stains, removes residual powder and weakly adhering splashes, while reducing thermal shock. The diversion mechanism can switch the liquid flow path, cleaning the parts downwards and directly rinsing the inner wall of the protective cover. Combined with the guide plate, it prevents impurity accumulation. The impact mechanism uses convex balls to shake off filter screen residue, ensuring long-term unobstructed flow. In conjunction with the temperature control mechanism, the protective cover is stably controlled at 80~150℃. The warm cleaning liquid will not cause rapid cooling or condensation due to excessive temperature differences during rinsing, and the liquid activity is better, forming a closed loop of "anti-sticking + hot rinsing". Simultaneously, the collection ring in the physical protection can collect shaken-off impurities and quickly disassemble for cleaning, achieving dual cleaning of parts and the protective cover, self-cleaning of the filter screen, and long-term self-sustaining performance at the system level. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a three-dimensional structural schematic diagram of the present invention; Figure 2 This is a schematic diagram of the structure of the laser printer in this invention; Figure 3 This is a cross-sectional view of the protective cover in this invention; Figure 4 This is a schematic diagram of the structure of the circulation pipe in this invention; Figure 5 This is a schematic diagram of the structure of the storage ring in this invention; Figure 6 This is a top-view cross-sectional structural diagram of the storage box in this invention; Figure 7 This is a partial cross-sectional view of the circulation pipe in this invention; Figure 8 This is a partial cross-sectional view of the storage box in this invention; Figure 9 In this invention Figure 3 A schematic diagram of the structure at point A; Figure 10 In this invention Figure 4 A schematic diagram of the structure at point B; Figure 11 This is a schematic diagram of the flow guide column in this invention; Figure 12 This is a schematic diagram of the structure of the convex sphere in this invention.

[0020] In the image: 1. Laser printer; 2. Print head; 3. Nozzle; 10. Protective mechanism; 11. Connecting ring; 12. Connecting rod; 13. Protective cover; 14. Screw; 15. Storage ring; 16. Limiting block; 17. Limiting groove; 20. Temperature control mechanism; 21. Storage box; 22. Miniature water pump; 23. Discharge pipe; 24. Suction pipe; 25. Return pipe; 26. Placement tank; 27. Circulation pipe; 28. Agitator assembly; 281. Agitator plate; 282. Baffle; 29. Heat exchanger assembly; 291. Cooling element; 292. Fan blade; 30. Spraying mechanism; 31. Cavity; 32. Connecting pipe; 33. Filter screen; 34. Guide column; 40. Diverting mechanism; 41. Through cavity; 42. Closing plate; 43. Electromagnet; 44. Electromagnetic block; 45. Guide plate; 46. Drain plate; 50. Impact mechanism; 51. Slide bar; 52. Curved plate; 53. Convex ball; 60. Liquid storage box. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Please see Figure 1-12 As shown, a laser additive manufacturing equipment for metal parts includes a laser printer 1 and a printhead 2 installed inside the laser printer 1. The printhead 2 has a nozzle 3 at its bottom. It also includes a protective mechanism 10, which includes a connecting ring 11 secured to the printhead 2 by screws 14. Several connecting rods 12 are fixedly installed at the bottom of the connecting ring 11. A protective cover 13, narrow at the top and wide at the bottom, is fixedly installed at the bottom of each connecting rod 12. The protective cover 13 has a through-hole design. Inside the protective cover 13 is a through-hole design receiving ring 15, also narrow at the top and wide at the bottom, with an arc-shaped cross-section. Several limiting blocks 16 are fixedly installed on the sidewalls of the receiving ring 15, and several limiting grooves 17 that match the limiting blocks 16 are formed inside the protective cover 13.

[0023] During operation, before using the printhead 2 of the laser printer 1, first place the storage ring 15 designed by Zhongtong into the protective cover 13, and use the upper limit block 16 of the storage ring 15 to insert into the limiting groove 17 of the protective cover 13 for fixation, making the two as one unit. After completing the above operation, put the connecting ring 11 on the printhead 2, and tighten the screw 14 to tighten and fix the connecting ring 11 on the printhead 2. The connecting ring 11 is fixed to the printhead 2 together with the protective cover 13 through several connecting rods 12 at the bottom, so that the protective cover 13 covers the bottom of the nozzle 3 to form protection.

[0024] The designed protective mechanism 10, with its connecting ring 11 and connecting rod 12, fixes the narrow-at-the-top and wide-at-the-bottom central shield 13 to the bottom of the print head 2, covering the nozzle 3. This effectively blocks high-temperature molten metal droplets and unmelted powder particles splashed from the molten pool, preventing them from contaminating or burning optical lenses, clogging powder channels, and damaging sensors, thereby ensuring stable laser energy transmission and powder flow morphology. The conical central structure of the shield 13 not only adapts to the diverging powder flow and laser beam below the nozzle 3, but also constrains and guides the local inert protective gas: the narrow-at-the-top and wide-at-the-bottom channel slows down sudden changes in gas flow rate, forming a stable and wider laminar air curtain around the nozzle 3 outlet, effectively isolating external air, reducing the oxygen content in the molten pool area, and reducing oxidation defects. Meanwhile, the arc-shaped cross-section receiving ring 15 installed inside the protective cover 13 also features a design that is narrower at the top and wider at the bottom, with a central through-hole. Its arc-shaped inner wall facilitates the guidance of splashes or condensed metal particles to slide down the wall and collect at the bottom of the receiving ring 15, preventing impurities from accumulating on the inner wall of the protective cover 13 and rebounding back into the molten pool or blocking the gas flow channel. The cooperation between the limiting block 16 and the limiting groove 17 allows the receiving ring 15 to be quickly disassembled and installed, facilitating regular cleaning and thus maintaining the protective effect over a long period of time. The entire mechanism is secured to the print head 2 with screws 14, resulting in a compact structure that does not affect the original movement flexibility of the print head 2.

[0025] It is important to note that during laser powder directed energy deposition, a fixed working distance must always be maintained between the end of nozzle 3 and the surface of the object to be deposited. This gap is a physical prerequisite for ensuring that the laser focus accurately lands on the powder convergence point and forms a stable molten pool. It also provides sufficient space for the metal powder to travel a long distance after being ejected from the annular channel to converge at the center of the laser spot. Furthermore, this gap allows for the escape of spatter and for inert gas to fully encapsulate the molten pool, preventing collisions between nozzle 3 and the high-temperature molten pool or protruding deposited layers. Therefore, when a protective cover 13 is installed around nozzle 3, as long as the lower end of the cover does not extend excessively beyond the nozzle 3 end face and a safe distance is maintained between the cover and the workpiece surface, it will not interfere with the normal movement of the print head 2 or the transmission of laser powder, ensuring that the protective cover 13 is always in a non-contact protective state.

[0026] A temperature control mechanism 20 is provided on the connecting ring 11. The temperature control mechanism 20 includes a storage box 21 fixedly installed on the connecting ring 11. A micro water pump 22 and a liquid storage box 60 are fixedly installed inside the storage box 21. The micro water pump 22 is equipped with an outlet pipe 23 and a suction pipe 24 that are connected to the inside. One end of the suction pipe 24 is connected to the inside of the liquid storage box 60. Specifically, the protective cover 13 has an internal slot 26 for installing the circulation pipe 27. One end of the circulation pipe 27 is connected to the outlet pipe 23, and the other end of the circulation pipe 27 is fixedly installed with a return pipe 25 that communicates with the interior. One end of the return pipe 25 is connected to the interior of the liquid storage box 60. An agitation assembly 28 is installed inside the circulation pipe 27. The agitation assembly 28 includes a twisted agitator plate 281 fixedly installed inside the circulation pipe 27. A baffle 282 with through holes is also fixedly installed inside the circulation pipe 27. A heat exchange assembly 29 is installed inside the liquid storage box 60. The heat exchange assembly 29 includes several cooling plates 291 mounted on the liquid storage box 60, and several fan blades 292 are installed inside the liquid storage box 60.

[0027] During operation, since the protective cover 13 is installed on the print head 2, it will also heat up after prolonged use with the print head 2. At this time, by activating the micro water pump 22 in the storage box 21, the high-conductivity oil in the liquid storage box 60 is transported through the suction pipe 24 and the outlet pipe 23 to the circulation pipe 27 of the placement tank 26. The high-conductivity oil sludge then flows back into the liquid storage box 60 through the return pipe 25. The high-conductivity oil is carried by the agitator plate 281 in the circulation pipe 27, so that the high-conductivity oil is constantly in contact with the circulation pipe 27, avoiding the situation where only one side is in contact with the circulation pipe 27. The baffle 282 with the through hole is used to assist in agitating the high-conductivity oil, so that it can have more comprehensive contact with the circulation pipe 27. After the high-conductivity oil completes its flow in the circulation pipe 27 and enters the liquid storage box 60 through the return pipe 25, it will hit the fan blade 292 and drive it to rotate. The rotating fan blades 292 agitate the high-conductivity oil, ensuring it comes into full contact with the cooling plate 291 for heat exchange. This facilitates the recycling of the high-conductivity oil, allowing it to re-enter the circulation pipe 27 to control the temperature of the protective cover 13.

[0028] By designing the temperature control mechanism 20, the protective cover 13 can be actively and uniformly regulated, precisely controlling it within the ideal range of 80~150℃. This effectively suppresses the cold welding and high-temperature sintering of spatter, significantly reduces the adhesion and accumulation of impurities on the inner wall of the protective cover 13 and the collection ring 15, extends the cleaning cycle, and makes the curved surface of the collection ring 15 easier to guide impurities to slide down and be collected. At the same time, the stable temperature of the protective cover 13 helps maintain the uniformity of the local inert gas flow field at the nozzle 3 outlet, reduces the interference of thermal disturbance on the gas curtain, and enhances the anti-oxidation protection effect of the molten pool area. Combined with the previous physical protection structure, active temperature control makes up for the shortcomings of passive shielding in dealing with temperature problems. Previously, relying solely on the collection ring 15 to collect spatter could not solve the sintering and adhesion caused by temperature. Now, through temperature control, the protective cover 13 is always kept at the "non-stick and non-welding" window temperature, which not only protects the protective cover 13 itself, but also makes the disassembly and cleaning of the collection ring 15 more efficient. In addition, the integrated design does not increase the external volume of the printhead 2, ensuring the flexibility of movement of the original protective mechanism 10.

[0029] A liquid spraying mechanism 30 is provided on the protective cover 13. The liquid spraying mechanism 30 includes several cavities 31 opened inside the protective cover 13. Several connecting pipes 32 corresponding to the cavities 31 are fixedly installed on the surface of the protective cover 13. The connecting pipes 32 are connected to a water source. A filter screen 33 is fixedly installed at the bottom of the cavity 31. A guide column 34 with a through-hole design is fixedly installed at the bottom of the filter screen 33. The outer surface of the guide column 34 is designed to expand outward.

[0030] Specifically, the protective cover 13 is equipped with a diversion mechanism 40, which includes a through cavity 41 that is opened inside the protective cover 13 and communicates with the cavity 31. A closing plate 42 is rotatably connected to the through cavity 41 via a torsion spring. An electromagnetic block 44 and an arc-shaped guide plate 45 are fixedly installed on one side of the closing plate 42. An electromagnet 43 is fixedly installed inside the cavity 31. An arc-shaped diversion plate 46 is fixedly installed on the inner wall of the through cavity 41.

[0031] Specifically, an impact mechanism 50 is provided inside the cavity 31. The impact mechanism 50 includes a slide rod 51 that slides inside the cavity 31 via a spring. An arc-shaped plate 52 is fixedly installed on the top of the slide rod 51, and several convex balls 53 are fixedly installed on the bottom of the arc-shaped plate 52.

[0032] During operation, after printhead 2 completes laser printing, a finished object will be on the base of the mechanical printer. At this time, printhead 2 moves along with the protective cover 13. Simultaneously, the water source connected to the connecting pipe 32 (using a water-based neutral cleaning agent, or a suitable liquid agent depending on the actual situation) is connected and injected into cavity 31. It then contacts the guide plate 45 on the closing plate 42, using the guide plate 45 to assist the water source to flow downwards, causing the water source in cavity 31 to be sprayed out. The sprayed water source is dispersed by filter screen 33, and the filter screen 33 also reduces the entry of impurities when cavity 31 is not in use. As the water source is sprayed out through filter screen 33, some of the water source is sprayed directly downwards through the central guide column 34, while the other part of the water source is guided to the surrounding area by the arc surface of the guide column 34, thereby expanding the spraying area and allowing the water source to be sprayed onto the printed object as comprehensively as possible.

[0033] After spraying the object, electromagnet 43 and electromagnet block 44 are energized, causing them to attract each other. Closed plate 42, driven by electromagnet block 44, rotates towards electromagnet 43, bringing them into contact. The rotating closed plate 42 seals cavity 31, connecting connecting pipe 32 and cavity 41. The rotating closed plate 42, along with the arc-shaped guide plate 45, compresses arc-shaped plate 52, causing slide rod 51, spring, and convex ball 53 to move downwards. The convex ball 53 impacts filter screen 33, reducing residual liquid and adhering impurities on its surface and ensuring unobstructed flow. The connected connecting pipe 32 and cavity 41 spray subsequently injected water onto the inner wall of the protective cover 13. Simultaneously, the arc-shaped guide plate 46 guides the sprayed water downwards.

[0034] The spray mechanism 30 utilizes heated water, which is dispersed by the filter screen 33 and expanded outward by the guide column 34 to achieve uniform spraying of the molded parts and the inner wall of the protective cover 13. The warm liquid can efficiently dissolve oil stains, remove residual powder and weakly adhering splashes, while reducing thermal shock. The diversion mechanism 40 can switch the liquid flow path, cleaning the parts downwards and directly rinsing the inner wall of the protective cover 13. With the guidance of the guide plate 46, it prevents impurities from accumulating. The impact mechanism 50 uses the convex ball 53 to shake off the residue on the filter screen 33, ensuring long-term unobstructed flow. In conjunction with the temperature control mechanism 20, the protective cover 13 is stably controlled at 80~150℃. The warm cleaning liquid will not cause rapid cooling or condensation due to excessive temperature difference during rinsing, and the liquid activity is better, forming a closed loop of "anti-sticking + hot rinsing". At the same time, the collection ring 15 in the physical protection can collect the shaken-off impurities and quickly disassemble and clean them. The whole system achieves dual cleaning of parts and protective cover 13, self-cleaning of filter screen 33, and long-term self-sustaining capacity at the system level.

[0035] The working principle is as follows: Before using the printhead 2 of the laser printer 1, the storage ring 15 designed by Zhongtong is first placed inside the protective cover 13, and the upper limit block 16 of the storage ring 15 is inserted into the limiting groove 17 of the protective cover 13 for fixation, making the two a single unit. After completing the above operations, the connecting ring 11 is then placed on the printhead 2, and the screw 14 is tightened to make the connecting ring 11 tighten and fix it on the printhead 2. The connecting ring 11 is fixed to the printhead 2 together with the protective cover 13 through several connecting rods 12 at the bottom, so that the protective cover 13 covers the bottom of the nozzle 3 to form protection.

[0036] Since the protective cover 13 is installed on the print head 2, it will also heat up after prolonged use with the print head 2. At this time, by activating the micro water pump 22 in the storage box 21, the high-conductivity oil in the liquid storage box 60 is transported through the suction pipe 24 to the circulation pipe 27 of the placement tank 26 via the outlet pipe 23. The high-conductivity oil sludge then flows back into the liquid storage box 60 through the return pipe 25. The high-conductivity oil is carried by the agitator plate 281 in the circulation pipe 27, so that the high-conductivity oil is constantly changing its contact with the circulation pipe 27, avoiding the situation where only one side is in contact with the circulation pipe 27. The baffle 282 with the through hole is used to assist in agitating the high-conductivity oil, so that it can make more comprehensive contact with the circulation pipe 27. After the high-conductivity oil completes its flow in the circulation pipe 27 and enters the liquid storage box 60 through the return pipe 25, it will hit the fan blade 292 and drive it to rotate. The rotating fan blades 292 agitate the high-conductivity oil, ensuring it comes into full contact with the cooling plate 291 for heat exchange. This facilitates the recycling of the high-conductivity oil, allowing it to re-enter the circulation pipe 27 to control the temperature of the protective cover 13.

[0037] After printhead 2 completes laser printing, a finished object will be on the base of the mechanical printer. At this time, printhead 2 moves with the protective cover 13. Simultaneously, the water source connected to the connecting pipe 32 is connected and injected into the cavity 31, where it contacts the guide plate 45 on the closing plate 42. The guide plate 45 assists the water source to flow downwards, causing the water in the cavity 31 to be sprayed out. The sprayed water source is dispersed by the filter screen 33. At the same time, when the cavity 31 is not in use, the filter screen 33 can also reduce the entry of impurities. As the water source is sprayed out through the filter screen 33, some of the water source will be sprayed directly downwards through the central guide column 34, while the other part of the water source will be guided to the surrounding area by the arc surface of the guide column 34, thereby expanding the spraying area and allowing the water source to be sprayed onto the printed object as comprehensively as possible.

[0038] After spraying the object, electromagnet 43 and electromagnet block 44 are energized, causing them to attract each other. Closed plate 42, driven by electromagnet block 44, rotates towards electromagnet 43, bringing them into contact. The rotating closed plate 42 seals cavity 31, connecting connecting pipe 32 and cavity 41. The rotating closed plate 42, along with the arc-shaped guide plate 45, compresses arc-shaped plate 52, causing slide rod 51, spring, and convex ball 53 to move downwards. The convex ball 53 impacts filter screen 33, reducing residual liquid and adhering impurities on its surface and ensuring unobstructed flow. The connected connecting pipe 32 and cavity 41 spray subsequently injected water onto the inner wall of the protective cover 13. Simultaneously, the arc-shaped guide plate 46 guides the sprayed water downwards.

[0039] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0040] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A laser additive manufacturing apparatus for metal parts, comprising a laser printer (1) and a printhead (2) installed within the laser printer (1), wherein a nozzle (3) is provided at the bottom of the printhead (2); characterized in that: Also includes: The protective mechanism (10) includes a connecting ring (11) that is fastened to the print head (2) by screws (14). Several connecting rods (12) are fixedly installed at the bottom of the connecting ring (11). A protective cover (13) that is narrow at the top and wide at the bottom is fixedly installed at the bottom of the connecting rods (12). The protective cover (13) is designed with a through-hole. The protective cover (13) has a centrally located storage ring (15) inside. The storage ring (15) is narrow at the top and wide at the bottom, and its cross-section is arc-shaped.

2. The laser additive manufacturing equipment for metal parts according to claim 1, characterized in that: The side wall of the storage ring (15) is fixedly installed with several limiting blocks (16), and the inside of the protective cover (13) is provided with several limiting grooves (17) that are compatible with the limiting blocks (16).

3. The laser additive manufacturing equipment for metal parts according to claim 1, characterized in that: A temperature control mechanism (20) is provided on the connecting ring (11). The temperature control mechanism (20) includes a storage box (21) fixedly installed on the connecting ring (11). A micro water pump (22) and a liquid storage box (60) are fixedly installed inside the storage box (21). The micro water pump (22) is equipped with an outlet pipe (23) and a suction pipe (24) that are connected to the inside. One end of the suction pipe (24) is connected to the inside of the liquid storage box (60). The inside of the protective cover (13) is provided with a placement groove (26) for installing the circulation pipe (27). One end of the circulation pipe (27) is connected to the outlet pipe (23), and the other end of the circulation pipe (27) is fixedly installed with a return pipe (25) connected to the inside. One end of the return pipe (25) is connected to the inside of the storage box (60).

4. The laser additive manufacturing equipment for metal parts according to claim 3, characterized in that: The circulation tube (27) is provided with an agitation assembly (28), which includes an agitation plate (281) that is fixedly installed inside the circulation tube (27) and is in a twisted shape. The circulation tube (27) is also fixedly installed with a baffle (282) with a through hole.

5. The laser additive manufacturing equipment for metal parts according to claim 3, characterized in that: The liquid storage box (60) is provided with a heat exchange component (29), which includes a number of cooling plates (291) installed on the liquid storage box (60), and a number of fan blades (292) are installed inside the liquid storage box (60).

6. The laser additive manufacturing equipment for metal parts according to claim 1, characterized in that: The protective cover (13) is provided with a spraying mechanism (30), which includes several cavities (31) opened inside the protective cover (13). Several connecting pipes (32) corresponding to the cavities (31) are fixedly installed on the surface of the protective cover (13), and the connecting pipes (32) are connected to a water source.

7. The laser additive manufacturing equipment for metal parts according to claim 6, characterized in that: A filter screen (33) is fixedly installed at the bottom of the cavity (31), and a guide column (34) with a central through-hole design is fixedly installed at the bottom of the filter screen (33). The outer surface of the guide column (34) is designed to expand outward.

8. The laser additive manufacturing equipment for metal parts according to claim 6, characterized in that: The shield (13) is provided with a diversion mechanism (40). The diversion mechanism (40) includes a through cavity (41) opened in the shield (13) and connected to the cavity (31). A closing plate (42) is rotatably connected in the through cavity (41) by a torsion spring. An electromagnetic block (44) and an arc-shaped guide plate (45) are fixedly installed on one side of the closing plate (42). An electromagnet (43) is fixedly installed inside the cavity (31).

9. The laser additive manufacturing equipment for metal parts according to claim 8, characterized in that: An arc-shaped drainage plate (46) is fixedly installed on the inner wall of the cavity (41).

10. The laser additive manufacturing equipment for metal parts according to claim 8, characterized in that: An impact mechanism (50) is provided inside the cavity (31). The impact mechanism (50) includes a slide rod (51) that slides inside the cavity (31) via a spring. An arc plate (52) is fixedly installed on the top of the slide rod (51), and several convex balls (53) are fixedly installed on the bottom of the arc plate (52).

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