High-power coaxial gas-driven drum laser cladding powder feeder and operation method

Abstract

The invention relates to a high-power coaxial gas-driven drum laser cladding powder feeder and an operation method, the high-power coaxial gas-driven drum laser cladding powder feeder comprises a coaxial powder feeding assembly, the coaxial powder feeding assembly is located above a workbench and used for carrying out laser cladding processing on a workpiece on the workbench, and the coaxial powder feeding assembly is connected with a powder feeder assembly. The stirrer is additionally arranged in the powder storage hopper and is driven by the motor A, so that the problems of agglomeration, bridging and low stacking density of ultrafine powder are effectively avoided, the fluidity of the powder is improved, the conveying amount of the powder can be accurately controlled through the design of the powder feeding wheel and the adjustment of the rotating speed, and uniform conveying of the powder is ensured; and the pneumatic conveying structure is additionally arranged, so that the powder is uniformly and stably conveyed out under the action of gas kinetic energy, and the problem that the powder is bonded and agglomerated is solved.

Description

Technical Field

[0001] The present invention relates to the field of laser processing technology, and in particular to a high-power coaxial gas-driven drum laser cladding powder feeder and an operating method thereof. Background Art

[0002] In recent years, laser melting has become a new research and development direction in the field of laser processing technology. It places the coating material to be clad on the surface body of the cladding through different feeding methods. After high-density laser radiation, the coating material and the thin layer on the surface of the body are melted at the same time. However, the coating material is rarely diluted by the body, and its original composition and properties can basically be kept unchanged. After rapid solidification, it forms a surface coating with extremely low dilution that forms a metallurgical bond with the body, thereby significantly improving the corrosion resistance, wear resistance, heat resistance, oxidation resistance and ignition properties of the substrate surface. It is a new surface improvement technology, and the powder feeder is the key equipment for laser cladding. The quality of its powder feeding directly affects the cladding effect. Therefore, research on the powder feeder is extremely important.

[0003] In synchronous powder feeders, poor fluidity is a difficulty in conveying ultrafine powders. Due to the agglomeration and stickiness of fine powders, powder feeding is discontinuous and uneven, resulting in uneven thickness of the cladding layer, poor surface quality, and serious quality of precision cladding and micro-molding. For example, ultrafine powders such as nanophase powders are prone to agglomeration during transportation, and the current powder feeders have not yet been well resolved.

[0004] Based on a large number of research results, in view of the application characteristics of laser remanufacturing technology and the difficulty in conveying ultrafine powders, the applicant needs to design an air-carrying drum powder feeder for ultrafine powder conveying. Summary of the invention

[0005] The purpose of the present invention is to provide a high-power coaxial gas-driven drum laser cladding powder feeder and an operating method, in order to solve the problem of difficult metal powder transportation, achieve the purpose of uniform powder feeding and quantitative powder feeding, and solve a series of problems in the general powder feeding process, such as powder unevenness, powder blockage, powder easy oxidation, and easy moisture.

[0006] In order to solve the above technical problems, the present invention provides a high-power coaxial gas-driven drum laser cladding powder feeder, comprising: a coaxial powder feeding assembly, the coaxial powder feeding assembly is located above a workbench and is used to perform laser cladding processing on a workpiece on the workbench, the coaxial powder feeding assembly is connected to a powder feeder assembly;

[0007] A powder feeder assembly comprises a powder storage hopper, a motor A is installed on the top of the powder storage hopper, the motor A is connected to an agitator rotatably installed inside the powder storage hopper, the powder storage hopper is installed on the top of a shell, and a powder discharge hopper installed at the bottom of the powder storage hopper penetrates into a powder falling chamber inside the shell, a powder feeding wheel is rotatably installed in a cylindrical groove on one side of the powder falling chamber of the shell, a row of powder grooves are arranged outside the powder feeding wheel, the powder feeding wheel is driven to rotate by a motor B on the back of the shell, a connected powder falling pipe is provided on the other side of the cylindrical groove, part of the powder feeding wheel is in the powder falling pipe and the powder falling chamber, and since the powder feeding wheel fits the cylindrical groove, the powder groove inside the cylindrical groove naturally forms a powder feeding chamber, the bottom end of the powder falling pipe passing through the shell is connected to a powder discharge pipe, the powder discharge pipe is connected to a powder distributor, and the powder distributor is connected to a coaxial powder feeding assembly through another four powder discharge pipes to discharge powder;

[0008] An air pipe 1 connected to a powder dropping pipe is installed on the top of the shell, the upper end of the air pipe 1 is connected to a flow divider, and the flow divider is connected to an air source output system.

[0009] Preferably, the coaxial powder feeding assembly includes a focusing mirror connecting sleeve, the focusing mirror connecting sleeve is connected to one end of the laser output tube, and the other end of the focusing mirror connecting sleeve is connected to a reflector seat, a total reflector is installed inside the reflector seat, and the focusing mirror seat is installed on an open end on one side of the reflector seat through a lubricating bearing, and a focusing mirror is also installed on the inner wall of the focusing mirror seat.

[0010] Preferably, a telescopic guide sleeve is installed on the opening surface of the lower end of the focusing mirror, a nozzle seat is fixedly sleeved on the outside of the telescopic guide sleeve, and a fitting nozzle sleeve is sleeved on the outside of the nozzle seat.

[0011] Preferably, the lower ends of the nozzle seat and the nozzle sleeve are both conically designed, the semi-cylindrical opening of the inner wall of the nozzle sleeve and the outer wall of the nozzle seat form a nozzle opening, four injection joints are installed on the top of both ends of the nozzle seat, and a flow channel connecting the injection joint and the nozzle opening is provided inside the nozzle seat, and the injection joint is connected and docked with the powder distributor through four powder outlet pipes.

[0012] Preferably, the lower end of the powder falling chamber passes through the shell, and the bottom end of the cylindrical groove is also provided with a discharge port passing through the shell, and the lower end of the powder falling chamber and the discharge port are both installed with sealing plugs for recovering residual powder.

[0013] Preferably, one side of the shell is provided with an opening, the side wall of the powder dropping tube is exposed in the opening, and the shell is fixedly mounted with a lens on the outer wall of the opening by means of a gland and bolts.

[0014] Preferably, the upper end of the diverter is also connected to an air pipe 2, and the other end of the air pipe 2 is connected to the upper end position inside the powder storage hopper.

[0015] The present invention also provides an operating method of a high-power coaxial gas-driven drum laser cladding powder feeder, comprising:

[0016] S1. Device preparation and powder loading:

[0017] Check whether all parts of the device are installed well and make sure the sealing plug is in the closed state to prevent powder leakage. Open the top cover of the powder storage hopper, add an appropriate amount of powder material into the powder storage hopper, close the top cover of the powder storage hopper, and start the motor A. Through the rotation of the agitator, the powder in the powder storage hopper is evenly distributed to avoid agglomeration.

[0018] S2. Start-up of powder feeding system and powder delivery:

[0019] Start the motor B to make the powder delivery wheel start to rotate. According to the characteristics of the powder and processing requirements, adjust the speed of the powder delivery wheel to control the powder delivery amount. Turn on the gas source output system. The gas enters the powder drop pipe through the splitter and the air pipe 1. The powder, carried by the gas, enters the powder distributor through the powder outlet pipe. The powder distributor evenly distributes the powder to the four powder outlet pipes. The powder enters the injection joint of the coaxial powder delivery assembly from the powder outlet pipe, flows along the flow channel set inside the nozzle seat, and finally sprays out from the nozzle mouth;

[0020] S3, Laser Cladding Processing:

[0021] While the coaxial powder feeding assembly prepares the powder, start the laser source of the laser output tube. The laser beam is reflected by the focusing mirror connecting sleeve, the reflector seat and the total reflector, and is finally focused into a small light spot by the focusing mirror. The length of the telescopic guide sleeve is adjusted to make the distance between the nozzle opening and the workpiece surface appropriate to ensure that the powder can accurately hit the focus of the laser beam. After the powder is ejected from the nozzle opening, it is rapidly heated and melted under the irradiation of the laser beam, and at the same time, it contacts the workpiece surface and undergoes metallurgical bonding to form a cladding layer. During the processing, the powder flow in the powder drop tube can be observed through a lens to ensure the stability and uniformity of powder delivery.

[0022] Preferably, when the S2 powder feeding system is started and the powder is being conveyed, the powder feeding wheel has a very small powder tank volume, and the purpose of accurate powder feeding is achieved by adjusting the rotation speed, the diameter of the powder leakage hole, and the gap between the powder leakage hole and the drum wheel. The powder feeding amount is calculated using the rotation speed of the powder wheel as follows:

[0023] g = nmvρ Formula 1;

[0024] Among them, n is the rotation speed of the powder wheel, m is the number of slots, v is the slot volume, and ρ is the bulk density of the powder.

[0025] Preferably, during the startup of the S2 powder feeding system and the powder conveying, the ratio of the mass flow rate of the powder conveyed by the powder falling pipe to the mass flow rate of the conveying gas is in the range of 0.01-15 kg / kg.

[0026] The beneficial effects of the present invention are:

[0027] 1. The present invention effectively avoids the problems of agglomeration, bridging and low packing density of ultrafine powders by adding an agitator in the powder storage hopper and driving it by the motor A, thereby improving the fluidity of the powder. The design of the powder feeding wheel and the adjustment of the rotation speed can accurately control the powder conveying amount and ensure the uniform conveying of the powder. Moreover, by adding a pneumatic conveying structure, the powder is evenly and stably conveyed under the action of the kinetic energy of the gas, thereby solving the problem of adhesion and agglomeration between powders.

[0028] 2. The present invention ensures the synchronous delivery of the laser beam and the powder flow through the design of the coaxial powder feeding assembly. The powder can accurately hit the focus of the laser beam, thereby improving the uniformity and surface quality of the cladding layer. The special design of the nozzle assembly, such as the conical nozzle seat and nozzle sleeve, and the evenly distributed nozzle openings, further enhances the focusing and acceleration effects of the powder, so that the powder can be quickly heated and melted, forming a good metallurgical bond with the workpiece surface.

[0029] 3. The present invention allows the operator to observe the powder flow in the powder drop pipe by installing a lens, thereby ensuring the stability and uniformity of powder delivery and improving the transparency and operability of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0031] Figure 1 It is an overall front view of the high-power coaxial gas-driven drum laser cladding powder feeder and the operating method of the present invention;

[0032] Figure 2 It is an overall side view of the high-power coaxial gas-driven drum laser cladding powder feeder and the operating method of the present invention;

[0033] Figure 3 It is a front cross-sectional view of a powder feeder assembly of the high-power coaxial gas-driven drum laser cladding powder feeder and operating method of the present invention;

[0034] Figure 4 It is a side cross-sectional view of the shell of the high-power coaxial gas-driven drum laser cladding powder feeder and the operating method of the present invention;

[0035] Figure 5 It is a side view of a coaxial powder feeding assembly of the high-power coaxial gas-driven drum laser cladding powder feeder and operation method of the present invention;

[0036] Figure 6 It is a front cross-sectional view of a coaxial powder feeding assembly of the high-power coaxial gas-driven drum laser cladding powder feeder and operation method of the present invention;

[0037] Figure 7 A three-dimensional view of the powder feeding wheel of the high-power coaxial gas-driven drum laser cladding powder feeder and the operating method of the present invention;

[0038] Figure 8 It is a front cross-sectional view of the nozzle seat of the high-power coaxial gas-driven drum laser cladding powder feeder and operation method of the present invention.

[0039] Fig. 9 It is a front cross-sectional view of the housing of the high-power coaxial gas-driven drum laser cladding powder feeder and the operating method of the present invention;

[0040] Fig.10 A top view of the nozzle seat of the high-power coaxial gas-driven drum laser cladding powder feeder and operating method of the present invention.

[0041] In the figure:

[0042] 1. Coaxial powder feeding assembly; 11. Focusing mirror connecting sleeve; 12. Laser output tube; 13. Reflector seat; 14. Full reflector; 15. Lubricating bearing; 16. Focusing mirror seat; 17. Focusing mirror; 18. Telescopic guide sleeve; 19. Nozzle assembly; 191. Nozzle seat; 192. Nozzle sleeve; 193. Nozzle mouth; 194. Injection joint; 2. Powder feeder assembly; 21. Powder storage hopper; 22. Motor A; 23. Agitator; 24. Powder discharge hopper; 25. Shell; 26. Powder falling chamber; 27. Powder feeding wheel; 28. Powder trough; 29. ​​Motor B; 210. Powder falling pipe; 211. Powder discharge pipe; 212. Powder distributor; 213. Lens; 214. Air pipe 1; 215. Sealing plug; 216. Air pipe 2; 217. Diverter. DETAILED DESCRIPTION

[0043] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0044] like Figure 1-Figure 10 As shown, the high-power coaxial gas-driven drum laser cladding powder feeder and operation method of the present invention include:

[0045] A coaxial powder feeding assembly 1, which is located above a workbench 4 and is used for laser cladding processing of a workpiece on the workbench 4. The coaxial powder feeding assembly 1 is connected to a powder feeder assembly 2;

[0046] The powder feeder assembly 2 includes a powder storage hopper 21, a motor A22 is installed on the top of the powder storage hopper 21, and the motor A22 is connected to the agitator 23 rotatably installed inside the powder storage hopper 21. The powder storage hopper 21 is installed on the top of the shell 25, and the powder discharge hopper 24 installed at the bottom of the powder storage hopper 21 penetrates into the powder falling cavity 26 inside the shell 25. The shell 25 is rotatably installed in the cylindrical groove on one side of the powder falling cavity 26. The powder feeding wheel 27 is provided with a row of powder grooves 28 on the outside. The powder feeding wheel 27 passes through the back of the shell 25. The motor B29 on the surface drives the rotation, and a connected powder falling pipe 210 is provided on the other side of the cylindrical groove. Part of the powder feeding wheel 27 is in the powder falling pipe 210 and the powder falling chamber 26. Since the powder feeding wheel 27 fits the cylindrical groove, the powder groove 28 located inside the cylindrical groove naturally forms a powder feeding chamber. The bottom end of the powder falling pipe 210 passing through the shell 25 is connected to a powder outlet pipe 211, and the powder outlet pipe 211 is connected to a powder separator 212. The powder separator 212 is connected to the coaxial powder feeding assembly 1 through the other four powder outlet pipes 211 to discharge powder;

[0047] The top of the shell 25 is equipped with an air pipe 214 connected to the powder dropping pipe 210. The upper end of the air pipe 214 is connected to the diverter 217, and the diverter 217 is connected to the air source output system. This is an existing design and will not be described in detail in the figure and text.

[0048] As mentioned above, during operation, powder is added to the powder storage hopper 21, and the motor A22 rotates to drive the agitator 23 to rotate so that the powder in the powder storage hopper 21 is prevented from agglomerating. This is in view of the characteristics of agglomeration, bridging, and low bulk density of ultrafine powder materials in the container, and an arch-breaking stirring assembly system is added to the powder hopper of the powder feeder. The agitator 23 rotates regularly to stir the powder for uniform flow, thereby preventing the powder from sticking and adsorbing on the wall of the powder storage hopper 21 and forming bridges in the powder discharge hopper 24. Then, the motor B29 is also started, and the powder discharge hopper 24 rotates. According to the characteristics of the ultrafine powder, the structure size of the powder discharge hopper 24 is The outer diameter of the powder hopper 24 is provided with a powder groove 28. The volume of the powder groove 28 can be adjusted according to the actual situation. It is closely related to the powder breaking effect and the powder conveying amount. The synchronous air pipe 214 and the diverter 217 provide the necessary gas pressure for the powder feeder assembly 2. The gas enters the powder falling pipe 210 from the diverter 217 and the air pipe 214. This is because although the particles that stick to each other can be broken up mechanically, the size of the particles after mechanical dispersion is limited after all, and the powder will still exist in the form of small lumps, so the interaction between the powders will still exist. , the powder still sticks together and agglomerates. In addition, before the powder is blown from the powder nozzle to the metal molten pool, in order to ensure good surface quality, the powder that needs to be sprayed out has been mixed evenly and is in a mist form. The above two problems need to be solved in the powder conveying process. Therefore, according to our conveying requirements, a pneumatic conveying structure is added. Then the powder trough 28 with powder is transferred to the space of the powder falling pipe 210. The rotating powder flows into the powder falling pipe 210 under the action of its own weight and compressed gas, and then enters the powder outlet pipe 211. Since the volume of the powder trough 28 is quite small, it plays the role of breaking up the powder for conveying. At the same time, by adjusting the outlet The rotation speed of the powder hopper 24, the diameter of the powder leakage hole and the gap between the powder leakage hole and the drum wheel can achieve the purpose of accurate powder delivery. Therefore, a gas powder flow system is added to assist. This system can enable the powder feeder to transport powder with smaller particle size. The powder chamber is filled with gas and maintains a stable pressure. Under the action of the gas kinetic energy, the powder is not evenly and stably transported out. The powder finally enters the powder separator 212 through the powder outlet pipe 211, and is introduced into the coaxial powder feeding assembly 1 through the other four powder outlet pipes 211 by the powder separator 212. The coaxial powder feeding assembly 1 is responsible for simultaneously transporting the laser and powder materials to the workpiece surface for laser cladding processing.

[0049] The coaxial powder feeding assembly 1 comprises a focusing lens connecting sleeve 11, which is connected to one end of a laser output tube 12, and the other end of the focusing lens connecting sleeve 11 is connected to a reflector seat 13, a total reflector 14 is installed inside the reflector seat 13, a focusing lens seat 16 is installed at an open end on one side of the reflector seat 13 through a lubricating bearing 15, and a focusing lens 17 is also installed on the inner wall of the focusing lens seat 16;

[0050] A telescopic guide sleeve 18 is installed on the open surface of the lower end of the focusing mirror 17, and a nozzle assembly 19 is provided at the lower end of the telescopic guide sleeve 18, including a nozzle seat 191 fixedly sleeved on the outside of the telescopic guide sleeve 18, and a fitting nozzle sleeve 192 is sleeved on the outside of the nozzle seat 191. The lower ends of the nozzle seat 191 and the nozzle sleeve 192 are both conical in design, and four semi-cylindrical openings evenly distributed on the inner wall of the nozzle sleeve 192 form a nozzle port 193 with the outer wall of the nozzle seat 191. Four injection joints 194 are installed on the top of both ends of the nozzle seat 191, and a flow channel connecting the injection joint 194 and the nozzle port 193 is provided inside the nozzle seat 191, and the injection joint 194 is connected to the powder distributor 212 through four powder outlet pipes 211.

[0051] As described above, after the powder passes through the precise powder feeding process of the powder feeder assembly 2, it is fed into the powder distributor 212, and the powder is evenly distributed to the four powder outlet pipes 211. The four powder outlet pipes 211 are directly connected to the injection joint 194 of the coaxial powder feeding assembly 1. After the powder enters the injection joint 194 from the powder outlet pipe 211, it flows along the flow channels set inside the nozzle seat 191. These flow channels are carefully designed to ensure that the powder can flow evenly and stably to the nozzle opening 193. The conical design of the nozzle seat 191 and the nozzle sleeve 192 not only It helps to focus and accelerate the powder, and also ensures the stability and uniformity of the powder flow at the nozzle opening 193, forming a Kong's coaxial powder feeding nozzle. The characteristic of this powder feeding nozzle is that four independent powder feeding nozzle openings 193 are evenly distributed along the outer circumference of the nozzle seat 191. The powder sprayed from the outlets of the four nozzle openings 193 converge at one point, that is, the center point of the opening at the lower end of the nozzle seat 191, which can evenly disperse the powder into a ring and then converge it into the focused laser. In production, it can be as flexible as using a metal pen to achieve special processing effects. At the same time, it also has various functions required by laser cladding technology, and is suitable for the manufacturing of three-dimensional stereoscopic forming by laser cladding. At the nozzle mouth 193, the powder meets the laser beam emitted from the laser output tube 12. The laser beam first enters the reflector seat 13 through the focusing mirror connecting sleeve 11, and is guided to the focusing mirror 17 under the reflection of the total reflector 14. The focusing mirror focuses the laser beam into a small light spot, which is exactly where the powder flow will hit. The light spot is emitted from the center point of the lower opening of the nozzle seat 191. Due to the special design of the nozzle mouth 193, the powder flow is rapidly heated and melted under the irradiation of the laser beam. At the same time, due to the fitting design of the nozzle seat 191 and the nozzle sleeve 192, and the guiding and telescopic effect of the telescopic guide sleeve 18, the telescopic guide sleeve 18 is an existing conventional design, and the powder flow can maintain a certain speed and direction, and is adjustable to ensure that they can accurately hit the surface of the workpiece. Finally, on the surface of the workpiece, the molten powder and the substrate quickly merge to form a dense cladding layer. This process not only improves the hardness and wear resistance of the workpiece, but also improves its surface quality.

[0052] It should be noted that the powder convergence point coincides with the focus of the laser beam, and the position of the powder convergence point relative to the laser convergence point is adjustable in the axial direction. Secondly, a flow channel connecting the injection joint 194 and the nozzle port 193 is provided inside the nozzle seat 191. The flow channel and the nozzle port 193 are as small as possible without being blocked, which can effectively ensure the powder convergence effect. Finally, each flow channel and the nozzle port 193 adopts airflow to carry and independently deliver powder at the same time to ensure that the powder will not be segregated at a large inclination angle. Finally, the inner conical semi-cylindrical hole of the nozzle sleeve 192 and the outer conical surface of the nozzle seat 191 constitute a powder delivery channel, so the cooperation between the two must be strictly required. Considering that general equipment rather than professional equipment is currently used for processing, this will inevitably cause certain technical errors. Therefore, in the selection of work tolerance, the outer conical surface of the nozzle seat 191 is taken as +0 / -0.1. The purpose is to ensure that a sufficiently small annular gap is obtained at the outlet of the powder delivery channel through reasonable setting of tolerances to meet the adjustment requirements of the size of the powder delivery channel.

[0053] The lower end of the powder dropping chamber 26 passes through the shell 25, and the bottom end of the cylindrical groove is also provided with a discharge port that passes through the shell 25. The lower end and the discharge port of the powder dropping chamber 26 are both installed with sealing plugs 215 for recovering residual powder. An opening is provided on one side of the shell 25, and the side wall of the powder dropping tube 210 is exposed in the opening. The shell 25 is fixed with a lens 213 on the outer wall of the opening by a pressure cover and bolts. An air pipe 216 is also connected to the upper end of the diverter 217, and the other end of the air pipe 216 is connected to the upper end of the powder storage hopper 21.

[0054] As mentioned above, the powder feeder assembly 2 is further optimized. When the device is working, the sealing plug 215 is closed to allow powder to enter the powder feeding system. When the device is not working, the sealing plug 215 is opened to recover some residual powder, which is very convenient. The lens 213 is fixed to the opening of the shell 25 by a gland and bolts. Its position makes it possible to observe the powder flow in the powder falling tube 210, that is, the powder falling tube 210 is made of transparent material, which not only improves the sealing and cleanliness of the device, but also facilitates the observation and adjustment of the powder flow. Finally, the air pipe 216 will also enter the gas during gas transportation, and then enter the powder storage hopper 21, and the smoothness of the powder falling from the powder storage hopper 21 is ensured by air pressure.

[0055] The present invention also provides an operating method of a high-power coaxial gas-driven drum laser cladding powder feeder, comprising:

[0056] S1. Device preparation and powder loading:

[0057] Check whether all parts of the device are installed well, make sure the sealing plug 215 is in the closed state to prevent powder leakage, open the top cover of the powder storage hopper 21, add an appropriate amount of powder material into the powder storage hopper, close the top cover of the powder storage hopper, and start the motor A22. Through the rotation of the agitator 23, the powder in the powder storage hopper 21 is evenly distributed to avoid agglomeration.

[0058] S2. Start-up of powder feeding system and powder delivery:

[0059] Start the motor B29 to make the powder delivery wheel 27 start to rotate. According to the characteristics of the powder and the processing requirements, adjust the speed of the powder delivery wheel 27 to control the powder delivery amount. Turn on the gas source output system. The gas enters the powder falling pipe 210 through the diverter 217 and the air pipe 1 214. The powder, carried by the gas, enters the powder distributor 212 through the powder outlet pipe 211. The powder distributor 212 evenly distributes the powder to the four powder outlet pipes 211. The powder enters the injection joint 194 of the coaxial powder delivery assembly 1 from the powder outlet pipe 211, flows along the flow channel set inside the nozzle seat 191, and is finally ejected from the nozzle opening 193.

[0060] S3, Laser Cladding Processing:

[0061] While the coaxial powder feeding assembly 1 prepares the powder, the laser source of the laser output tube 12 is started, and the laser beam is reflected by the focusing mirror connecting sleeve 11, the reflector seat 13 and the total reflector 14, and is finally focused into a small light spot by the focusing mirror 17. The length of the telescopic guide sleeve 18 is adjusted to make the distance between the nozzle opening 193 and the workpiece surface appropriate to ensure that the powder can accurately hit the focus of the laser beam. After the powder is ejected from the nozzle opening 193, it is rapidly heated and melted under the irradiation of the laser beam, and at the same time contacts with the workpiece surface and undergoes metallurgical bonding to form a cladding layer. During the processing, the powder flow in the powder drop tube 210 can be observed through the lens 213 to ensure the stability and uniformity of powder transportation.

[0062] S2 During the powder feeding system startup and powder conveying, the powder feeding wheel 27 achieves accurate powder feeding by adjusting the rotation speed, the diameter of the powder leakage hole and the gap between the powder leakage hole and the drum wheel because the volume of the powder trough 28 is quite small. The powder feeding amount is calculated by the rotation speed of the powder wheel:

[0063] g = nmvρ Formula 1;

[0064] Among them, n is the rotation speed of the powder wheel, m is the number of slots, v is the slot volume, and ρ is the bulk density of the powder. By adjusting these parameters, the system can flexibly control the powder feeding amount.

[0065] During the start-up of the S2 powder feeding system and powder conveying, the ratio of the mass flow rate of the powder being conveyed in the powder drop pipe 210 to the mass flow rate of the conveying gas (referred to as the solid-gas ratio) is relatively small (usually in the range of 0.01-15kg / kg), the distance between powder particles is large, the pressure of the conveying gas is low (usually <0.1MPa), and the conveying speed is high (usually <13-15m / s). Dilute phase conveying is generally suitable for occasions where the mass and particle size of the conveyed powder are small, dry, and the conveying distance is not large. The solid-gas ratio of dense phase conveying is usually in the range of 15-200kg, the conveying gas pressure is relatively high (for example, it can reach 0.7-0.8Mpa), and the conveying speed is relatively low (generally about half of the dilute phase conveying speed). It is suitable for occasions with large conveying volumes and long conveying distances. By precisely controlling this ratio, the system can maintain the continuity and stability of powder conveying under different working conditions. For example, when a high powder delivery rate is required, the flow rate of the conveying gas can be increased to maintain an appropriate powder-gas ratio. When the powder delivery rate needs to be finely controlled, the flow rate of the conveying gas can be reduced and the speed of the powder delivery wheel can be adjusted accordingly.

[0066] Finally, the influence of air humidity on ultrafine powder is taken into consideration before designing. The powder is dried before the airflow enters the powder feeding equipment. For this purpose, an air filter is needed to filter out water, oil, etc. in the air. In addition, a flow meter is needed to adjust the air delivery volume, which is also convenient for controlling the air flow rate of different powder delivery volumes. I will not go into details here.

[0067] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. High power coaxial gas driven drum laser cladding powder feeder, characterized in that: include: A coaxial powder feeding assembly (1), the coaxial powder feeding assembly (1) being located above a workbench (4) and being used for performing laser cladding processing on a workpiece on the workbench (4), the coaxial powder feeding assembly (1) being connected to a powder feeder assembly (2); The powder feeder assembly (2) comprises a powder storage hopper (21), a motor A (22) is installed on the top of the powder storage hopper (21), the motor A (22) is connected to an agitator (23) rotatably installed inside the powder storage hopper (21), the powder storage hopper (21) is installed on the top of a shell (25), and a powder discharge hopper (24) installed at the bottom of the powder storage hopper (21) penetrates into a powder dropping cavity (26) inside the shell (25), the shell (25) is rotatably installed with a powder feeding wheel (27) in a cylindrical groove on one side of the powder dropping cavity (26), the powder feeding wheel (27) is provided with a row of powder grooves (28) on the outside, and the powder feeding wheel (27) The motor B (29) on the back of the housing (25) drives the housing (25) to rotate. A powder dropping pipe (210) is provided on the other side of the cylindrical groove. A part of the powder delivery wheel (27) is in the powder dropping pipe (210) and the powder dropping chamber (26). Since the powder delivery wheel (27) fits the cylindrical groove, the powder groove (28) located inside the cylindrical groove naturally forms a powder delivery chamber. The bottom end of the powder dropping pipe (210) passing through the housing (25) is connected to a powder outlet pipe (211). The powder outlet pipe (211) is connected to a powder distributor (212). The powder distributor (212) is connected to a coaxial powder delivery assembly (1) through four other powder outlet pipes (211) to discharge powder. The top of the shell (25) is provided with an air pipe (214) connected to the powder dropping pipe (210), the upper end of the air pipe (214) is connected to a flow divider (217), and the flow divider (217) is connected to an air source output system.

2. The high-power coaxial gas-driven drum laser cladding powder feeder according to claim 1, characterized in that: The coaxial powder feeding assembly (1) comprises a focusing mirror connecting sleeve (11), wherein the focusing mirror connecting sleeve (11) is connected to one end of a laser output tube (12), and the other end of the focusing mirror connecting sleeve (11) is connected to a reflector seat (13), a total reflector (14) is installed inside the reflector seat (13), a focusing mirror seat (16) is installed at an open end on one side of the reflector seat (13) via a lubricating bearing (15), and a focusing mirror (17) is also installed on the inner wall of the focusing mirror seat (16).

3. The high-power coaxial gas-driven drum laser cladding powder feeder according to claim 2, characterized in that: A telescopic guide sleeve (18) is installed on the open surface at the lower end of the focusing mirror (17), and a nozzle assembly (19) is provided at the lower end of the telescopic guide sleeve (18), including a nozzle seat (191) fixedly sleeved on the outside of the telescopic guide sleeve (18), and a fitting nozzle sleeve (192) is sleeved on the outside of the nozzle seat (191).

4. The high-power coaxial gas-driven drum laser cladding powder feeder according to claim 3, characterized in that: The lower ends of the nozzle seat (191) and the nozzle sleeve (192) are both conically designed, and the semi-cylindrical opening of the inner wall of the nozzle sleeve (192) and the outer wall of the nozzle seat (191) form a nozzle opening (193). Four injection joints (194) are installed at the top of both ends of the nozzle seat (191), and a flow channel connecting the injection joint (194) and the nozzle opening (193) is provided inside the nozzle seat (191), and the injection joint (194) and the powder distributor (212) are connected and docked through four powder outlet pipes (211).

5. The high-power coaxial gas-driven drum laser cladding powder feeder according to claim 1, characterized in that: The lower end of the powder dropping chamber (26) passes through the shell (25), and the bottom end of the cylindrical groove is also provided with a discharge port that passes through the shell (25). The lower end of the powder dropping chamber (26) and the discharge port are both installed with sealing plugs (215) for recovering residual powder.

6. The high-power coaxial gas-driven drum laser cladding powder feeder according to claim 1, characterized in that: An opening is provided on one side of the shell (25), and the side wall of the powder dropping tube (210) is exposed in the opening. The shell (25) is fixedly mounted with a lens (213) on the outer wall of the opening by means of a gland and bolts.

7. The high-power coaxial gas-driven drum laser cladding powder feeder according to claim 1, characterized in that: The upper end of the flow divider (217) is also connected to a second air pipe (216), and the other end of the second air pipe (216) is connected to the upper end of the powder storage hopper (21).

8. The method for operating the high-power coaxial gas-driven drum laser cladding powder feeder according to claims 1-7, characterized in that: include: S1. Device preparation and powder loading: Check whether all parts of the device are installed properly and ensure that the sealing plug (215) is in a closed state to prevent powder leakage. Open the top cover of the powder storage hopper (21), add an appropriate amount of powder material into the powder storage hopper, close the top cover of the powder storage hopper, and start the motor A (22). Through the rotation of the agitator (23), the powder in the powder storage hopper (21) is evenly distributed to avoid agglomeration. S2. Start-up of powder feeding system and powder delivery: The motor B (29) is started to make the powder feeding wheel (27) start to rotate. According to the characteristics of the powder and the processing requirements, the rotation speed of the powder delivery wheel (27) is adjusted to control the powder delivery amount, and the gas source output system is turned on. The gas enters the powder drop pipe (210) through the diverter (217) and the gas pipe 1 (214). The powder, carried by the gas, enters the powder distributor (212) through the powder outlet pipe (211). The powder distributor (212) evenly distributes the powder to the four powder outlet pipes (211). The powder enters the injection joint (194) of the coaxial powder delivery assembly (1) from the powder outlet pipe (211), flows along the flow channel provided inside the nozzle seat (191), and is finally ejected from the nozzle opening (193); S3, Laser Cladding Processing: While the coaxial powder feeding assembly (1) prepares the powder, the laser source of the laser output tube (12) is started, and the laser beam is reflected by the focusing mirror connecting sleeve (11), the reflecting mirror seat (13) and the total reflecting mirror (14), and finally focused by the focusing mirror (17) into a fine light spot. The length of the telescopic guide sleeve (18) is adjusted to make the distance between the nozzle opening (193) and the workpiece surface appropriate to ensure that the powder can accurately hit the focus of the laser beam. After the powder is ejected from the nozzle opening (193), it is rapidly heated and melted under the irradiation of the laser beam, and at the same time contacts with the workpiece surface and metallurgically combines to form a cladding layer. In the process, the powder flow in the powder drop tube (210) can be observed through the lens (213) to ensure the stability and uniformity of powder transportation.

9. The method of high power coaxial gas driven drum laser cladding powder feeder as claimed in claim 8, characterized in that: When the powder feeding system S2 is started and the powder is being conveyed, the powder feeding wheel (27) achieves accurate powder feeding by adjusting the rotation speed, the diameter of the powder leakage hole and the gap between the powder leakage hole and the drum wheel because the volume of the powder feeding wheel (27) is quite small. The powder feeding amount is calculated by the rotation speed of the powder wheel: g = nmvρ Formula (1); Among them, n is the rotation speed of the powder wheel, m is the number of slots, v is the slot volume, and ρ is the bulk density of the powder.

10. The method of high power coaxial gas driven drum laser cladding powder feeder as claimed in claim 8, characterized in that: When the S2 powder conveying system is started and during powder conveying, the ratio of the mass flow rate of the powder conveyed by the powder drop pipe (210) to the mass flow rate of the conveying gas is in the range of 0.01-15 kg / kg.

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