A 3D printing device and its application in online printing of field components, 3D printing method

Abstract

The application discloses a 3D printing device and application thereof in on-site component online printing, a 3D printing method, and the 3D printing device comprises a printing mechanism, a scanning mechanism, a moving mechanism and a storage chamber, the storage chamber has a cavity, the printing mechanism and the scanning mechanism are located in the cavity of the storage chamber, the bottom of the storage chamber is connected with the moving mechanism, and the moving mechanism is used for driving the storage chamber to move; the scanning mechanism comprises a first moving piece and a scanning part, and the first moving piece is used for extending the scanning part outward from the cavity to the position of a component to be repaired; the printing mechanism comprises a laser cleaning assembly, a laser shock peening assembly and a 3D printing laser additive assembly, the top of the printing mechanism is provided with a second moving piece, and the second moving piece is used for extending the printing mechanism outward from the cavity to the position of the component to be repaired. The 3D printing device can be applied to the defects of on-site offline or online forming and repairing, and can comprehensively solve the problems of 3D printing in the component forming and repairing process.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of 3D printing manufacturing, and particularly relates to a 3D printing device under laser composite field and application of the 3D printing device in online printing of field components and a 3D printing method. BACKGROUND

[0002] 3D printing technology, also known as additive manufacturing technology, is a material fusion rapid prototyping technology. Through digital modeling, layer processing and superposition forming, the 3D printing technology prints a three-dimensional part and manufactures a solid object based on a digital model file through software and a numerical control system, in which special metal materials, non-metal materials and medical biological materials are stacked layer by layer in the form of extrusion, sintering, melting, light curing and spraying. Compared with the traditional material forming methods such as casting, forging and subtractive processing, the 3D printing technology is a net forming process, which does not need to use a grinding tool, has a short manufacturing cycle, saves materials and reduces costs. Meanwhile, the 3D printing technology can realize the manufacturing of gradient functional materials with continuous material composition change, and the manufacturing process is not limited by the complex structure of metal parts, which makes it possible to manufacture complex structural parts that cannot be realized by the traditional manufacturing methods.

[0003] 3D printing is constrained by the size of the component, high efficiency, and can realize the rapid forming of composite gradient materials, which has important application value and prospect in aerospace, military industry, nuclear industry, and petrochemical industry. However, for some complex structures, a large number of machining holes, and thin-walled components, especially for the forming and repair manufacturing of high-strength and high-hardness alloy materials, 3D printing is limited by its process characteristics, and there are some problems, including: 1) the existing 3D printing device is generally designed or installed in an industrial plant, and for some components that are difficult to send out or need to be formed or repaired on site, it cannot meet the needs of the site; 2) 3D printing has residual stress accumulated during the manufacturing process. The high-energy laser beam acts on the metal powder, and there is a large temperature gradient in the "melting-solidification-cooling" process of the metal powder. The cooling degree of each melting layer is limited by the continuity of the bottom solidified material. After layer-by-layer accumulation, a large residual tensile stress is formed in the formed component, which will reduce its fatigue resistance or cause deformation of the final component. When the stress is high enough, cracks will occur inside the component, leading to component cracking; 3) during the manufacturing process of 3D printing, the solution will splash onto the surface of the component, forming slag, especially for complex and porous components, the internal hole slag is difficult to clean, and the smoothness of the internal surface of the component cannot be guaranteed; 4) there is no closed forming and manufacturing room, and it cannot form a complete inert space, so the protection effect is poor, resulting in a high content of oxides in the component, and oxide inclusions are formed between each layer of the printed layer, which affects the overall performance of the formed or repaired component; 5) when laser shock peening is performed, a confinement layer is needed to limit the plasma diffusion, increase the peak pressure of the shock wave, and prolong the action time of the shock wave, so as to enhance the effect of laser shock peening. Currently, water layer, air confinement layer, optical glass, resin or silicone are commonly used, however, water layer needs a fixed water source, which is not suitable for on-site quick repair, air confinement layer directly uses air, i.e. no confinement layer, and the effect is poor; optical glass, resin or silicone have poor adaptability and cannot be well attached according to the shape of the component to be strengthened; 6) for equipment components that cannot be disassembled or are difficult to disassemble on site, online forming or repair cannot be achieved.

[0004] In view of the above problems existing in the process of 3D printing, the residual tensile stress in the 3D printed component is eliminated, the harmful residual tensile stress is converted into beneficial compressive stress, a confinement layer suitable for on-site, easy to prepare, and can efficiently enhance the impact effect is adopted, the residual confinement layer during the impact strengthening process and the splashed slag on the surface of the component during the 3D printing process can be cleaned, the smoothness of the surface of the component is guaranteed, and at the same time, it can be moved to the site to meet the off-line / on-line forming and repair needs of the site, so a 3D printing device needs to be developed. SUMMARY

[0005] In view of the above, in order to overcome the defects of the prior art, the purpose of the present application is to provide a 3D printing device, which can overcome the shortcomings of the current 3D printing means, such as single means, poor effect, and unsuitability for on-site offline / on-line forming and repairing, and comprehensively solve the problems of 3D printing in the process of component forming and repairing, and improve the strength, wear resistance, corrosion resistance and fatigue life of the 3D printed metal components.

[0006] In order to achieve the above purpose, the present application adopts the following technical solutions:

[0007] An object of the present application is to provide a 3D printing device, which comprises a printing mechanism, a scanning mechanism, a moving mechanism and a storage chamber, the storage chamber has a cavity, the printing mechanism and the scanning mechanism are located in the cavity of the storage chamber, the bottom of the storage chamber is connected with the moving mechanism, and the moving mechanism is used to drive the storage chamber to move; the scanning mechanism comprises a first moving part and a scanning part, the first moving part is used to extend the scanning part from the cavity of the storage chamber to the outside to the repaired component, so that the scanning part scans the repaired component; the printing mechanism comprises a laser cleaning assembly, a laser shock peening assembly and a 3D printing laser additive assembly, the top of the printing mechanism is provided with a second moving part, and the second moving part is used to extend the printing mechanism from the cavity of the storage chamber to the outside and perform on-line printing on the repaired component.

[0008] In some embodiments of the present application, the laser shock peening assembly uses a high-power density, short pulse laser beam to irradiate the surface of the component material, so that the absorption layer absorbs the laser energy to cause explosive vaporization and form high-temperature and high-pressure plasma. The plasma is limited by the confinement layer to form a high-pressure shock wave, which impacts the surface of the metal component, generating beneficial residual compressive stress in the impact area and eliminating harmful tensile stress generated during the 3D printing process. The laser cleaning assembly is used to improve the cleanliness of the formed component surface. Laser cleaning has the advantages of high efficiency, no damage to the substrate, easy cleaning of complex component hole walls, and convenience and speed, which can effectively clean the surface slag generated by splashing during 3D printing, reduce the post-processing of the component surface, especially the integrally formed component with holes; at the same time, the confinement layer remaining after the shock peening can also be removed without affecting the printing of the next layer of component. In addition, the scanning mechanism is used to scan the structure of the component that needs to be formed or repaired online, form three-dimensional data, build a three-dimensional body of the online component, compare with the original three-dimensional body diagram of the component, obtain the size of the part that needs to be formed or repaired online, form a three-dimensional model component, automatically plan a 3D printing path, and complete the online forming and repair of the difficult-to-disassemble component. In some embodiments of the present application, the side of the storage chamber has a sliding door that seals the cavity. When the sliding door is opened, the printing mechanism, scanning mechanism and the like can extend outward. The storage chamber is provided with a sliding door, and when the sliding door is closed, the entire storage chamber is kept sealed; the gas introduced is preferably an inert gas, so as to maintain an inert atmosphere environment in the cavity of the storage chamber, solving the oxidation problem in the current component forming process. The moving mechanism can ensure the convenient movement of the entire 3D printing device and can be suitable for various working environments.

[0009] According to some preferred embodiments of the present application, the control mechanism and the gas delivery mechanism are also included, the cavity includes a first cavity and a second cavity, a partition plate is arranged between the first cavity and the second cavity, the control mechanism and the gas delivery mechanism are located in the first cavity, and the printing mechanism, the scanning mechanism and the control mechanism are located in the second cavity; the gas delivery mechanism is used to deliver gas to the printing mechanism, and the gas delivery mechanism includes a gas source, a driver and a delivery pipeline, one end of the driver is connected with the gas source, the other end of the driver is connected with one end of the delivery pipeline, the delivery pipeline penetrates through the thickness direction of the partition plate, and the other end of the delivery pipeline is located in the second cavity. In some embodiments of the present application, a through opening is formed on the partition plate, and a transparent glass is installed at the through opening, so that the operator can observe the processing condition in the second cavity in the first cavity.

[0010] According to some preferred embodiments of the present application, the printing mechanism further comprises a rotating cylinder, and the laser cleaning assembly, the laser shock peening assembly and the 3D printing laser additive assembly are fixedly connected with the rotating cylinder; the second moving part is connected with the top of the rotating cylinder, and a first fixing seat and a second fixing seat are arranged on the inner wall of the top of the storage chamber, the first fixing seat is located above the rotating cylinder, and the end of the second moving part away from the rotating cylinder is connected with the first fixing seat. The rotating cylinder is arranged to facilitate the calling of the laser cleaning assembly, the laser shock peening assembly and the 3D printing laser additive assembly, and when any one of the components needs to be used for operation, the component to be used can be selected by rotating the rotating cylinder. The second moving part is used to extend the printing mechanism outward from the first cavity, so that the printing mechanism can be aligned with the on-site online component to be formed or repaired, thereby directly printing online. In addition, the same machining point can be manufactured without moving the workpiece.

[0011] According to some preferred embodiments of the present application, the second fixing seat is located in the same horizontal direction as the first fixing seat, one end of the first moving part is connected with the scanning part, and the other end of the first moving part is connected with the second fixing seat. The first moving part is arranged to facilitate the movement of the scanning part, so that the scanning part can extend outward from the second cavity and be used for scanning the on-site online component to be formed or repaired.

[0012] According to some preferred embodiments of the present application, the rotating table and at least one powder forming cylinder arranged on the rotating table are further arranged below the printing mechanism, a motor is further arranged below the rotating table, the motor is fixedly connected with the inner wall of the bottom of the storage chamber, and a rotating shaft is arranged between the rotating table and the motor; the motor is used to drive the rotating shaft to rotate to drive the rotating table to rotate.

[0013] According to some preferred embodiments of the present application, the bottom of the laser cleaning assembly, the bottom of the laser shock peening assembly and the bottom of the 3D printing laser additive assembly are arranged to form a virtual circle, the bottom area of the powder forming cylinder is greater than the area of the virtual circle, and when the rotating table drives one of the powder forming cylinders to rotate to the position directly below the printing mechanism, the virtual circle is located in the same vertical direction as the powder forming cylinder. It is guaranteed that the printed component can fall into the powder forming cylinder.

[0014] According to some preferred embodiments of the present application, a coating mechanism is arranged in the second cavity, which comprises a confinement layer material reservoir, a third moving part and a coating gun, the confinement layer material reservoir is fixedly connected with the inner wall of the side surface of the storage chamber, one end of the third moving part is connected with the confinement layer material reservoir, the other end of the third moving part is connected with one end of the coating gun, and the head of the coating gun is aligned with the powder forming cylinder. The coating gun is used to coat the confinement layer material in the confinement layer material reservoir to the surface of the component to enhance the laser shock effect, and the residual confinement layer material can be removed by laser cleaning without affecting the printing of the next layer of component.

[0015] According to some preferred embodiments of the present application, the confinement layer material reservoir is used to store the confinement layer material, and the confinement layer material is a gel. Unlike the traditional water layer, air confinement layer and optical glass as the confinement layer, the gel material with good adaptability is used as the confinement layer in some embodiments of the present application, which can be directly coated on the surface of the workpiece to be processed, so that it is completely attached to the surface of the component and easy to clean, and the effect of impact strengthening is effectively enhanced.

[0016] According to some preferred embodiments of the present application, the control mechanism comprises a control cabinet and a power supply box, and the control cabinet is electrically connected with the driver, the printing mechanism, the scanning mechanism and the coating mechanism. In some embodiments of the present application, the control mechanism further comprises a workbench, wires, a power plug and a control panel. Specifically, the control cabinet is used to control the actions of various mechanisms in the whole device, the wires are used to electrically connect the control cabinet with various mechanisms to transmit action instructions, the workbench is used to place the control cabinet and the control panel, the power plug is used to connect an external power supply for power supply, and the power supply box is used to distribute the externally connected power supply to various mechanisms. In some embodiments of the present application, the parameters of the printing mechanism are set and adjusted by operating the control panel. Specifically, the laser cleaning adopts a pulse laser, and the laser beam parameters are as follows: wavelength is 1064 nm, power is 0-500 W, pulse width is 100 fs-20 ps, frequency is 1 kHz-2 MHz, and scanning speed is 1-15 mm / s. The laser shock peening also adopts a pulse laser, and the laser beam parameters are as follows: wavelength is 1064 nm, pulse frequency is 1-20 Hz, pulse width is 1-10 ns, spot diameter is 0.2-5 mm, and single pulse energy is 1-50 J. The 3D printing laser adopts a continuous laser, and the laser beam parameters are as follows: wavelength is 1064 nm, power is 0-2000 W, spot diameter is 20-150 μm, and scanning speed is 10-1500 mm / s.

[0017] According to some preferred embodiments of the present application, the moving mechanism comprises a support base, a drive shaft, a load base, a track, a main rotating wheel and an auxiliary rotating wheel. The support base is provided with one drive shaft on each side, and the load base is fixedly connected to the top of the support base. The track is provided with two tracks, each of which is arranged on the outer periphery of two corresponding main rotating wheels. The two main rotating wheels are located at the two ends of the corresponding track, and the two main rotating wheels located on the same track are provided with a connecting shaft therebetween. The connecting shaft is uniformly provided with a plurality of auxiliary rotating wheels. The end of the drive shaft away from the support base is fixedly connected to the connecting shaft. The track-type moving mechanism can ensure the movement of the overall device and the stability of the device during movement, and can smoothly pass through obstacles such as steps or slopes.

[0018] Another object of the present application is to provide the use of the 3D printing device as described above for online printing of field components.

[0019] Still another object of the present application is to provide a 3D printing method using the 3D printing device as described above, which comprises the following steps:

[0020] After scanning the field component to be repaired by the scanning unit, the obtained three-dimensional model is compared with the three-dimensional model of the original component to obtain the part to be repaired online. The part to be repaired online is printed layer by layer by the printing mechanism until the repair is completed. Each layer of printing comprises the following steps in turn: laser cleaning, 3D printing, laser cleaning, applying a constraint layer material, laser shock peening, and laser cleaning of the constraint layer material.

[0021] Due to the above technical solutions, compared with the prior art, the 3D printing device of the present application has the following advantages:

[0022] (1) In the process of 3D printing additive manufacturing, a laser cleaning device is used to remove pollutants, including splashed slag and adhered powder, during the manufacturing process, thereby solving the problem of difficult cleaning of the surface of complex components or porous cavities;

[0023] (2) In the process of 3D printing additive manufacturing, a laser shock peening device is used to improve the organization and stress state of the component layer by layer, thereby realizing the regulation of the internal organization and residual stress of the 3D printed component, converting harmful residual tensile stress into beneficial compressive stress, solving the problem of crack initiation and cracking in the component, and improving the comprehensive performance of the component;

[0024] (3) The three-dimensional laser scanning technology is used to obtain the three-dimensional model of the component and compare it with the model of the original component to automatically obtain the part to be formed or repaired online, thereby enabling direct online 3D printing of field components.

[0025] (4) The device as a whole is movable, and can be conveniently moved to various work sites, thereby meeting the molding and repairing needs of site components. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced as follows. Obviously, the drawings described in the following embodiments are only some of the embodiments of the present application, and all other drawings obtained by those of ordinary skill in the art without creative labor based on these drawings should belong to the protection scope of the present application.

[0027] Figure 1 Structure diagram of the 3D printing device in the preferred embodiment of the present application;

[0028] Among them, the reference signs are: printing mechanism-1, laser cleaning assembly-11, laser shock peening assembly-12, 3D printing laser additive assembly-13, rotating cylinder-14, scanning mechanism-2, first moving part-21, scanning part-22, control mechanism-3, control cabinet-31, power box-32, workbench-33, power plug-34, control panel-35, gas delivery mechanism-4, gas source-41, driver-42, delivery pipeline-43, moving mechanism-5, carrier base-51, track-52, main rotating wheel-53, auxiliary rotating wheel-54, connecting shaft-55, storage chamber-6, first cavity-61, second cavity-62, partition-63, second moving part-64, first fixed seat-65, second fixed seat-66, coating mechanism-7, constraint layer material reservoir-71, third moving part-72, coating gun-73, rotary table-81, powder forming cylinder-82, motor-83, rotating shaft-84. DETAILED DESCRIPTION

[0029] In order to enable those skilled in the art to better understand the technical solutions of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely in the following with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor should belong to the protection scope of the present application.

[0030] REFERENCE Figure 1The embodiment provides a 3D printing device which can perform online or offline additive forming on a component on site. The 3D printing device comprises a printing mechanism 1, a scanning mechanism 2, a control mechanism 3, a gas delivery mechanism 4, a moving mechanism 5, a coating mechanism 7 and a storage chamber 6. The storage chamber 6 has a cavity which comprises a first cavity 61 and a second cavity 62, and a partition 63 is arranged between the first cavity 61 and the second cavity 62 to separate the first cavity 61 from the second cavity 62. The printing mechanism 1, the scanning mechanism 2 and the coating mechanism 7 are all located in the second cavity 62, and the control mechanism 3 and the gas delivery mechanism 4 are both located in the first cavity 61. In addition, a through opening is formed in the partition 63, and a transparent glass is arranged at the through opening, so that an operator can observe the processing condition in the second cavity 62 in the first cavity 61.

[0031] Further, the storage chamber 6 is provided with a sliding door on the side surface, so that the storage chamber 6 has an open state and a closed state, and meanwhile, the sliding door is arranged to facilitate the extension of the mechanisms in the cavity outward. The top of the second cavity 62 of the cavity in the storage chamber 6 is provided with a first fixing seat 65 and a second fixing seat 66, and the second fixing seat 66 is located in the same horizontal direction as the first fixing seat 65. The printing mechanism 1 comprises a rotating cylinder 14 and a laser cleaning assembly 11, a laser shock peening assembly 12 and a 3D printing laser additive assembly 13 connected with the rotating cylinder 14. The top of the rotating cylinder 14 is provided with a second moving part 64, the first fixing seat 65 is located above the rotating cylinder 14, one end of the second moving part 64 is connected with the first fixing seat 65, and the other end of the second moving part 64 is connected with the rotating cylinder 14. The rotating cylinder 14 is arranged to facilitate the calling of the laser cleaning assembly 11, the laser shock peening assembly 12 and the 3D printing laser additive assembly 13. When any component needs to be used for operation, the component can be selected by rotating the rotating cylinder 14. The second moving part 64 can extend the printing mechanism 1 outward from the first cavity 61, so that the printing mechanism 1 can be aligned with the component on site which needs to be formed or repaired online, thereby directly printing online. In addition, the same processing point can be manufactured without moving the workpiece. In some embodiments of the present application, the second moving part 64 is preferably a mechanical hand. In addition, a rotary table 81 is arranged below the printing mechanism 1. In the embodiment, two powder forming cylinders 82 are arranged on the rotary table 81, a motor 83 is further arranged below the rotary table 81, the motor 83 is fixedly connected with the inner wall of the bottom of the storage chamber 6, a rotating shaft 84 is further arranged between the rotary table 81 and the motor 83, the rotating shaft 84 is driven to rotate by the motor 83, thereby driving the rotary table 81 to rotate, so that the powder forming cylinders on the rotary table 81 can also rotate.

[0032] Specifically, the bottom of the laser cleaning assembly 11, the bottom of the laser shock peening assembly 12 and the bottom of the 3D printing laser additive assembly 13 are set to form a virtual circle together, the bottom area of the powder forming cylinder 82 is set to be larger than the area of the virtual circle; and when one of the powder forming cylinders 82 is rotated to the directly below the printing mechanism 1 by the rotating table 81, the virtual circle is in the same vertical direction with the powder forming cylinder 82, so that the printed component can be ensured to fall into the powder forming cylinder.

[0033] Further, the scanning mechanism 2 comprises a first moving part 21 and a scanning part 22, the second fixed seat 66 is located above the first moving part 21, one end of the first moving part 21 is connected with the second fixed seat 66, and the other end of the first moving part 21 is connected with the scanning part 22; the scanning part 22 can be moved out of the second cavity 62 of the storage chamber 6 cavity to the component to be repaired and scan the component to be repaired by driving the scanning part 22 to move through the first moving part 21. In the embodiment, the first moving part 21 is also preferably a mechanical hand.

[0034] Further, the coating mechanism 7 comprises a constraint layer material reservoir 71, a third moving part 72 and a coating gun 73. The constraint layer material reservoir 71 is used for storing constraint layer material, which is fixedly connected with the inner wall of the side of the second cavity 62 of the storage chamber 6 cavity, one end of the third moving part 72 is connected with the constraint layer material reservoir 71, and the other end of the third moving part 72 is connected with one end of the coating gun 73, and the gun head of the coating gun 73 is aligned with one of the powder forming cylinders 82 on the rotating table 81. In the present application, the constraint layer material is gel, which is coated on the surface of the component by the coating gun 73 to enhance the laser shock effect; and the residual constraint layer material can be removed by laser cleaning without affecting the printing of the next layer of component. Unlike the traditional water layer, air constraint layer and optical glass as the constraint layer, the gel material has good adaptability, can be directly coated on the surface of the workpiece to be processed, completely adheres to the surface of the component and is easy to clean, and effectively enhances the impact strengthening effect. The third moving part 72 of the embodiment is also preferably a mechanical hand.

[0035] Further, the gas delivery mechanism 4 comprises a gas source 41, a driver 42 and a delivery pipeline 43, one end of the driver 42 is connected with the gas source 41, the other end of the driver 42 is connected with one end of the delivery pipeline 43, and the delivery pipeline 43 penetrates through the thickness direction of the partition plate 63 so that one end of the delivery pipeline 43 is located in the second cavity 62. The gas source 41 in the embodiment is preferably inert gas, so as to maintain an inert atmosphere environment in the cavity of the storage chamber 6 and solve the oxidation problem in the component forming process.

[0036] Further, the control mechanism 3 comprises a control cabinet 31, a power supply box 32, a workbench 33, an electric wire, a power plug 34 and a control panel 35. The control cabinet 31 is electrically connected with the driver 42, the printing mechanism 1, the scanning mechanism 2 and the coating mechanism 7 for the control of the actions of the various mechanisms in the whole device. The electric wire is used to electrically connect the control cabinet 31 with the various mechanisms for the transmission of action instructions; the workbench 33 is used to place the control cabinet 31 and the control panel 35; the power plug 34 is used to connect an external power supply for power supply; the power supply box 32 is used to distribute the externally connected power supply to the various mechanisms. The parameters of the printing mechanism 1 are set and adjusted by operating the control panel 35 to complete the 3D printing of the components offline or online. Specifically, the settings of the various components in the printing mechanism 1 include: the laser cleaning uses a pulse laser, the laser beam parameters are: wavelength 1064 nm, power 0-500 W, pulse width 100 fs-20 ps, frequency 1 kHz-2 MHz, scanning speed 1-15 mm / s. The laser shock peening also uses a pulse laser, the laser beam parameters are: wavelength 1064 nm, pulse frequency 1-20 Hz, pulse width 1-10 ns, spot diameter 0.2-5 mm, single pulse energy 1-50 J. The 3D printing laser uses a continuous laser, the laser beam parameters are: wavelength 1064 nm, power 0-2000 W, spot diameter 20-150 μm, scanning speed 10-1500 mm / s.

[0037] Further, the moving mechanism 5 comprises a support seat, a driving shaft, a carrier base 51, a caterpillar 52, a main rotating wheel 53 and an auxiliary rotating wheel 54. One driving shaft is arranged on each side of the support seat, the bottom of the support seat is away from the ground, the carrier base 51 is fixedly connected with the top of the support seat, and the bottom of the storage chamber 6 is fixedly connected with the top of the carrier base 51. Two caterpillars 52 are arranged, and each caterpillar 52 is sleeved on the outer periphery of two corresponding main rotating wheels 53. The two main rotating wheels 53 are located at the two ends of the corresponding caterpillar 52, and a connecting shaft 55 is arranged between the two main rotating wheels 53 located on the same caterpillar 52. A plurality of auxiliary rotating wheels 54 are uniformly and spacedly arranged on the connecting shaft 55, and the main rotating wheel 53 and the auxiliary rotating wheel are used for driving the movement of the caterpillar 52. The end of the driving shaft away from the support seat is fixedly connected with the connecting shaft 55. The caterpillar 52 type moving mechanism 5 can not only ensure the movement of the whole device, but also ensure the stability of the device during the movement, and can smoothly pass through obstacles such as steps or slopes.

[0038] The method for the 3D printing device of the embodiment to perform online 3D printing on the site components is as follows:

[0039] (1) According to the field requirements, a certain part of the shaft is missing due to wear and impact, and the shaft is difficult to disassemble, so it needs to be repaired on site. The entire device is transported to the work site by the moving mechanism 5.

[0040] (2) Plug the power plug 34 into the conformal power supply on site to provide power for the entire device.

[0041] (3) Control the drive 42 through the control cabinet 31 to drive the delivery of inert gas, so that the second cavity 62 is filled with inert gas.

[0042] (4) Operate the control cabinet 31 to control the first moving part 21 to extend the scanning part 22 out of the second cavity 62, align the scanning part 22 with the worn shaft and scan it to obtain the three-dimensional shape of the shaft and compare it with the three-dimensional shape of the original component to obtain the part that needs to be repaired online, thereby generating a three-dimensional model of the repaired part, and processing it by slicing and layering, planning the 3D printing path according to the three-dimensional model slicing and layering data, and forming the component according to the planned 3D printing melting route. The scanning rate of the scanning part 22 is 2 million times / s, and the accuracy is 0.001 mm.

[0043] (5) Set the parameters of the printing mechanism 1, wherein the laser cleaning uses a pulse laser, the laser wavelength is set to 1064 nm, the power is 150 W, the pulse width is 150 fs, the frequency is 2 kHz, and the scanning speed is 15 mm / s; the 3D printing laser uses a continuous laser, the laser wavelength is set to 1064 nm, the power is 1500 W, the spot diameter is 80 μm, and the scanning speed is 15 mm / s; the laser shock peening uses a pulse laser, the laser wavelength is set to 1064 nm, the pulse frequency is 8 Hz, the pulse width is 2 ns, the spot diameter is 1.5 mm, and the single pulse energy is 15 J.

[0044] (6) Operate the control cabinet 31 to control the second moving part 64 to extend the printing mechanism 1 out of the second cavity 62, control the third moving part 72 to extend the coating mechanism 7 out of the second cavity 62, and make the printing mechanism 1 and the coating mechanism 7 close to the worn shaft to be repaired; control the rotating cylinder 14 to rotate the laser cleaning assembly 11 to the shaft, and according to the set process parameters, first clean the contaminants of the part to be repaired.

[0045] (7) After laser cleaning, control the rotating cylinder 14 to rotate the 3D printing laser additive assembly 13 to the shaft, and according to the set process parameters, perform first layer printing on the cleaned substrate.

[0046] (8) After the first layer is printed, the rotating cylinder 14 is controlled to rotate again to drive the laser cleaning assembly 11 to rotate to the shaft part, and the process parameters are set to remove the splashed slag and other pollutants in the forming process to improve the surface finish of the component.

[0047] (9) After the laser cleaning is completed, the coating mechanism 7 is controlled by the control cabinet 31 to enable the coating gun 73 to apply the gel constraint layer to the surface of the formed component, and then the rotating cylinder 14 is controlled to rotate to drive the laser impact assembly to rotate to the shaft part, and the process parameters are set to complete the impact strengthening of the first printing layer to eliminate the residual tensile stress in the coating and convert it into beneficial compressive stress.

[0048] (10) The rotating cylinder 14 is controlled to rotate again to rotate the laser cleaning assembly 11 to the shaft part, and the process parameters are set to remove the constraint layer involved in the laser impact strengthening.

[0049] (11) Steps (6) to (10) are repeated in turn to complete the layer-by-layer accumulation manufacturing of the shaft part.

[0050] In addition, the 3D printing device of the present application can also perform offline 3D printing on the component, including the following steps:

[0051] (1) The component of pure tungsten material is subjected to offline 3D printing, and the entire device is transported to the work site by the moving mechanism 5.

[0052] (2) The power plug 34 is plugged into the conformal power supply on site to provide power for the entire device.

[0053] (3) The control cabinet 31 controls the drive 42 to drive the delivery of inert gas to fill the second cavity 62 with inert gas.

[0054] (4) The three-dimensional drawing of the component is imported to complete the establishment of the three-dimensional model of the pure tungsten component and perform slice layering processing, plan the 3D printing path according to the three-dimensional model slice layering data, and perform component forming according to the planned 3D printing melting route.

[0055] (5) The parameters of the printing mechanism 1 are set, wherein the laser cleaning uses a pulse laser, the laser wavelength is set to 1064 nm, the power is set to 200 W, the pulse width is set to 200 fs, the frequency is set to 1 kHz, and the scanning speed is set to 10 mm / s; the 3D printing laser uses a continuous laser, the laser wavelength is set to 1064 nm, the power is set to 2000 W, the spot diameter is set to 100 μm, and the scanning speed is set to 20 mm / s; the laser impact strengthening uses a pulse laser, the laser wavelength is set to 1064 nm, the pulse frequency is set to 10 Hz, the pulse width is set to 5 ns, the spot diameter is set to 2 mm, and the single pulse energy is set to 25 J.

[0056] (6) According to the set program, the rotating cylinder 14 is controlled to rotate the laser cleaning assembly 11 to the top of the powder forming cylinder, and the bottom layer of the substrate is cleaned according to the set process parameters.

[0057] (7) After the laser cleaning is completed, the rotating cylinder 14 is controlled to rotate the 3D printing laser additive assembly 13 to the top of the powder forming cylinder, and the first layer of printing is performed on the cleaned substrate according to the set process parameters.

[0058] (8) After the first layer of printing is completed, the rotating cylinder 14 is controlled to rotate the laser cleaning assembly 11 again to the top of the powder forming cylinder, and the pollutants such as splashed slag in the forming process are cleaned according to the set process parameters, so as to improve the surface finish of the component.

[0059] (9) After the laser cleaning is completed, the coating mechanism 7 is controlled by the control cabinet 31, so that the gel restraining layer is coated on the surface of the formed component by the coating gun 73; then the rotating cylinder 14 is controlled to rotate the laser impact assembly to the top of the powder forming cylinder, and the impact strengthening of the first layer of printing is completed according to the set process parameters, so as to eliminate the residual tensile stress in the coating and convert it into beneficial compressive stress.

[0060] (10) The rotating cylinder 14 is controlled to rotate again to rotate the laser cleaning assembly 11 to the top of the powder forming cylinder, and the gel restraining layer after laser impact strengthening is cleaned according to the set process parameters.

[0061] (11) Steps (6) to (10) are repeated in turn to complete the layer-by-layer accumulation manufacturing of the component.

[0062] The above embodiments are only for illustrating the technical concept and characteristics of the present application, and the purpose is to enable those skilled in the art to understand the content of the present application and implement it, and cannot limit the protection scope of the present application. Any equivalent changes or modifications made according to the spirit and essence of the present application shall be covered within the protection scope of the present application.

Claims

1. A 3D printing device, characterized by The 3D printing device comprises a printing mechanism, a scanning mechanism, a moving mechanism, a storage chamber, a control mechanism and a gas delivery mechanism, the storage chamber has a cavity, the printing mechanism and the scanning mechanism are located in the cavity of the storage chamber, the bottom of the storage chamber is connected with the moving mechanism, and the moving mechanism is used to drive the storage chamber to move; the scanning mechanism comprises a first moving part and a scanning part, the first moving part is used to extend the scanning part from the cavity of the storage chamber to the outside to the repaired component, so that the scanning part scans the repaired component; the printing mechanism comprises a laser cleaning assembly, a laser shock peening assembly and a 3D printing laser additive assembly, the top of the printing mechanism is provided with a second moving part, the second moving part is used to extend the printing mechanism from the cavity of the storage chamber to the outside and to perform online printing on the repaired component; The cavity comprises a first cavity and a second cavity, a partition plate is arranged between the first cavity and the second cavity, the control mechanism and the gas delivery mechanism are located in the first cavity, and the printing mechanism, the scanning mechanism and the control mechanism are located in the second cavity; the gas delivery mechanism is used to deliver gas to the printing mechanism, the gas delivery mechanism comprises a gas source, a driver and a delivery pipeline, one end of the driver is connected with the gas source, the other end of the driver is connected with one end of the delivery pipeline, the delivery pipeline penetrates through the thickness direction of the partition plate, and the other end of the delivery pipeline is located in the second cavity; The 3D printing device further comprises a rotary table located below the printing mechanism and at least one powder forming cylinder arranged on the rotary table, a motor is further arranged below the rotary table, the motor is fixedly connected with the inner wall of the bottom of the storage chamber, and a rotating shaft is arranged between the rotary table and the motor; the motor is used to drive the rotating shaft to rotate to drive the rotary table to rotate; the bottom of the laser cleaning assembly, the bottom of the laser shock peening assembly and the bottom of the 3D printing laser additive assembly jointly form a virtual circle, the bottom area of the powder forming cylinder is greater than the area of the virtual circle; when the rotary table drives one powder forming cylinder to rotate to the position directly below the printing mechanism, the virtual circle and the powder forming cylinder are located in the same vertical direction.

2. The 3D printing device of claim 1, wherein, The printing mechanism further comprises a rotating cylinder, the laser cleaning assembly, the laser shock peening assembly and the 3D printing laser additive assembly are fixedly connected with the rotating cylinder; the second moving part is connected with the top of the rotating cylinder, a first fixing seat and a second fixing seat are arranged on the inner wall of the top of the storage chamber, the first fixing seat is located above the rotating cylinder, and one end of the second moving part, which is away from the rotating cylinder, is connected with the first fixing seat.

3. The 3D printing device of claim 2, wherein, The second fixing seat and the first fixing seat are located in the same horizontal direction, one end of the first moving part is connected with the scanning part, and the other end of the first moving part is connected with the second fixing seat.

4. The 3D printing device of claim 1, wherein, Also included in the second cavity is a coating mechanism, which includes a confinement layer material reservoir, a third moving part, and a coating gun. The confinement layer material reservoir is fixedly connected to the inner wall of the side surface of the storage chamber. One end of the third moving part is connected to the confinement layer material reservoir, and the other end of the third moving part is connected to one end of the coating gun. The head of the coating gun is aligned with the powder forming cylinder.

5. The 3D printing device of claim 4, wherein, The confinement layer material reservoir is used to store confinement layer material, which is a gel.

6. The 3D printing device of claim 4, wherein, The control mechanism includes a control cabinet and a power supply box, which are electrically connected to the driver, the printing mechanism, the scanning mechanism, and the coating mechanism.

7. The 3D printing apparatus according to claim 1, characterized in that, The moving mechanism includes a support seat, a drive shaft, a load base, a track, a main rotating wheel, and an auxiliary rotating wheel. Two drive shafts are arranged on the two sides of the support seat. The load base is fixedly connected to the top of the support seat. Two tracks are arranged on the two sides of the support seat. Each track is sleeved on the outer periphery of two corresponding main rotating wheels. Two main rotating wheels are arranged at the two ends of each track. Two auxiliary rotating wheels are arranged between the two main rotating wheels on the same track. The end of the drive shaft away from the support seat is fixedly connected to the connecting shaft.

8. A 3D printing method, characterized by, The 3D printing device of any one of claims 1-7 is used for 3D printing. The method for 3D printing includes the following steps: After scanning the site component to be repaired by the scanning part, the scanned data is compared with the three-dimensional model of the original component to obtain the part to be repaired online. The part to be repaired online is printed layer by layer by the printing mechanism until the repair is completed. Each layer printing step includes laser cleaning, 3D printing, laser cleaning, coating confinement layer material, laser shock peening, and laser cleaning of the confinement layer material.

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