A powder feeding device and a powder feeding method for laser additive manufacturing

Abstract

The application relates to the field of laser additive technology and discloses a laser additive powder feeding device and a powder feeding method, which comprise a shell, the upper side of the shell is fixedly connected with a feeding inlet, the side wall of the shell is fixedly connected with a driving motor one, the output end of the driving motor one is connected with a rotating column, the outer part of the rotating column is fixedly connected with a stirring rod, the side wall of the shell is fixedly connected with an electrostatic generator, the outer part of the electrostatic generator is electrically connected with a wire one, the outer part of the electrostatic generator is electrically connected with a wire two, and one end of the wire two is electrically connected with a magnetic coil. The driving motor one is started to drive the rotating column to rotate in the shell, then the stirring rod is synchronously rotated under the drive of the rotating column, and then the stirring rod preliminarily breaks and rubs the powder stored in the shell, so that the powder can be refined, the dispersion uniformity can be improved, and the effect of efficient and continuous powder conveying can be achieved by using the electrostatic adsorption and the magnetic field flow guiding effect.

Description

Technical Field

[0001] This invention relates to the field of laser additive manufacturing technology, specifically to a powder feeding device and method for laser additive manufacturing. Background Technology

[0002] Currently, there are two main methods for laser additive manufacturing of high-performance metal parts: one is laser cladding deposition technology based on synchronous powder feeding, and the other is laser selective melting technology based on pre-placed powder. However, due to differences in their forming methods and process parameters, these two technologies exhibit significant differences in several fundamental aspects of material forming, such as melt pool morphology, cooling rate, solidification structure, and mechanical properties. Although laser selective melting technology offers higher forming accuracy and better mechanical properties, it is limited in size and not suitable for forming large parts. Laser cladding deposition technology based on synchronous powder feeding can form larger parts and has certain advantages over laser selective melting technology. In the laser additive manufacturing process using laser cladding deposition technology based on synchronous powder feeding, many parameters affect the quality and properties of the formed parts, and powder flow is one of the key factors affecting the forming and properties of the formed parts. Since synchronous powder feeding uses carrier gas to transport powder, the powder flow has a relatively large divergence at the powder tube outlet.

[0003] Chinese Patent Publication No. CN108607993B discloses a magnetic flux powder feeding device for laser additive manufacturing, comprising: a frame; a powder charging device, including an energizing unit for charging the powder and a powder feeding unit for conveying the charged powder, wherein the energizing unit is located at the upstream powder inlet of the powder tube, and the downstream powder outlet of the powder feeding unit is located at the lower part of the frame via a powder tube position adjustment device; the powder tube position adjustment device is circumferentially located at the lower part of the frame; a magnetic flux powder device is mounted at the downstream powder outlet of the powder tube and has a magnetic field that can deflect the charged powder; and a laser emitting unit, the laser head of which is mounted on the frame, and the laser head's output port is aligned with the focal point of the charged powder delivered through the powder tube. The beneficial effects of this patent are: it greatly improves the convergence of the powder flow, which greatly helps to improve the forming quality of powder-feed laser additive manufacturing technology; and it allows for modification of existing lasers, thereby reducing costs.

[0004] Currently, in the field of synchronous powder feeding technology, as described in the aforementioned patent, many people have improved the convergence of powder flow by modifying the powder feeding device and nozzle shape. However, the powder flow is still relatively dispersed, resulting in problems such as intermittent, uneven, and inefficient powder delivery. Summary of the Invention

[0005] The purpose of this invention is to solve the problems mentioned in the background art, and thus proposes a powder feeding device and method for laser additive manufacturing. The invention starts a drive motor to rotate a rotating column inside the outer shell. Then, a stirring rod rotates synchronously under the drive of the rotating column. The stirring rod then initially breaks up and rubs the powder stored inside the shell. At this time, the powder becomes initially charged due to friction with the stirring rod. Subsequently, an electrostatic generator is activated, causing the powder stored on the upper side of the shell to come into contact with the discharge pipe and become charged. The control valve is opened, causing the powder to fall to the lower side of the shell. Simultaneously, the friction assembly is activated to perform secondary friction and breakup of the powder, preventing it from agglomerating. At this point, the powder is ejected at high speed from the shell under its own weight and the magnetic field generated by the magnetic coil. This achieves powder refinement, improves dispersion uniformity, and utilizes electrostatic adsorption and magnetic field guidance to achieve efficient and continuous powder conveying, while preventing agglomeration and improving the stability of the production process and the quality of the finished product.

[0006] The technical solution adopted by this invention to solve its technical problem is: A powder feeding device and method for laser additive manufacturing includes a housing. A feed inlet is fixedly connected to the upper side of the housing. A drive motor is fixedly connected to the side wall of the housing. A rotating column is connected to the output end of the drive motor. The rotating column is rotatably connected to the outside of the housing. A stirring rod is fixedly connected to the outside of the rotating column. A discharge pipe is fixedly connected to the inside of the housing. A control valve is fixedly connected to the inside of the discharge pipe. An electrostatic generator is fixedly connected to the side wall of the housing. A first wire and a second wire are electrically connected to the outside of the electrostatic generator. One end of the second wire is electrically connected to a magnetic coil, which is located inside the housing. A friction assembly is provided on the side wall of the housing.

[0007] By adopting the above technical solution, the powder is first fed into the shell through the feed inlet. The drive motor is started to drive the rotating column to rotate, which in turn drives the connected stirring rod to rotate synchronously, achieving initial crushing and friction of the powder, so that the powder is charged with static electricity. After running for a set time, the electrostatic generator is started, and the discharge pipe is energized through the first wire, further charging the powder in contact with it. At the same time, the built-in magnetic coil is powered through the second wire to form a guiding magnetic field. Then, the control valve is opened to let the powder fall, and the friction component is started simultaneously to perform secondary friction crushing of the powder to prevent powder agglomeration. Finally, the powder is sprayed out at high speed under the combined guiding effect of gravity and magnetic field, thereby achieving fine powder, uniform dispersion, continuous and stable conveying, avoiding material agglomeration, and ensuring production stability and finished product quality.

[0008] Preferably, the friction assembly includes a second drive motor, the output end of which is connected to a first friction roller, a first transmission gear fixedly connected to the outside of the first friction roller, a second transmission gear meshing with the teeth of the first transmission gear, and a second friction roller fixedly connected inside the second transmission gear.

[0009] Preferably, the second drive motor is externally fixedly connected to the side wall of the housing, the second friction roller is externally rotatably connected to the inside of the housing, and the first friction roller is externally rotatably connected to the outside of the housing.

[0010] Preferably, one end of the first wire is electrically connected to the inside of the discharge pipe, and the outside of the second wire is disposed inside the outer casing.

[0011] Preferably, the stirring rod is provided with a tension spring inside, one end of the tension spring is provided with a connecting rod, and one end of the connecting rod is fixedly connected to a scraping block.

[0012] Preferably, the outer part of the connecting rod is slidably connected to the inside of the stirring rod, and the outer part of the scraping block is disposed inside the outer shell.

[0013] Preferably, a storage box is fixedly connected to the outside of the outer shell, and a conveying pipe is provided inside the storage box, with the outside of the conveying pipe located inside the outer shell.

[0014] Preferably, a baffle is slidably connected inside the housing, a return spring is provided inside the housing, one end of the return spring is located outside the baffle, and a magnetic block is fixedly connected to the outside of the baffle.

[0015] Preferably, the magnetic block is composed of magnetic material.

[0016] As a preferred embodiment, a powder feeding method for a laser additive powder feeding device includes the following steps: S1. Feeding and preliminary mixing: Powder is fed into the shell through the feed port. The drive motor is started to drive the rotating column and stirring rod to rotate, which initially disperses and rubs the powder, so that the powder is initially charged. S2. Electrostatic and magnetic field preparation: Turn on the electrostatic generator, charge the discharge pipe through wire one, and at the same time supply power to the magnetic coil through wire two to generate a directional magnetic field. S3. Secondary friction and discharge control: Open the control valve to make the powder fall, and simultaneously start the second drive motor of the friction component. The powder is subjected to secondary friction crushing through the meshing rotation of friction roller one and friction roller two. S4. Magnetic field guided powder spraying: The powder is accelerated and sprayed out under the combined action of gravity and magnetic field; S5. Self-cleaning control: Increase the speed of the drive motor and use centrifugal force to make the scraper block rotate tightly against the inner wall of the outer shell to remove the attached powder. S6. Automatic material replenishment control: When the scraper block passes the magnetic block, the magnetic force attracts the baffle to open the conveying pipe, thereby automatically replenishing the powder in the storage box.

[0017] In summary, this application has the following beneficial effects: 1. This invention starts a drive motor to drive a rotating column to rotate inside the outer shell. Then, the stirring rod rotates synchronously under the drive of the rotating column. The stirring rod then initially breaks up and rubs the powder stored inside the outer shell. At this time, the powder becomes initially charged due to friction with the stirring rod. Then, the electrostatic generator is turned on, and the powder stored on the upper side of the outer shell comes into contact with the discharge pipe and becomes charged. The control valve is opened, causing the powder to fall to the lower side of the outer shell. At the same time, the friction component is activated to perform secondary friction and break up the powder, preventing the powder from agglomerating. At this time, the powder is sprayed out of the outer shell at high speed under its own weight and the magnetic field generated by the magnetic coil. This can achieve the effects of refining the powder, improving the dispersion uniformity, and using electrostatic adsorption and magnetic field guidance to achieve efficient and continuous powder conveying, while preventing agglomeration and improving the stability of the production process and the quality of the finished product.

[0018] 2. This invention increases the rotation speed of the rotating column and stirring rod by adjusting the power of the drive motor. At this time, the connecting rod inside the stirring rod undergoes centrifugal motion, and the scraper block moves synchronously under the drive of the connecting rod. Finally, the scraper block rotates against the inner wall of the outer shell. At this time, the sharp edge of the scraper block scrapes off the powder adhering to the side wall of the outer shell, thereby achieving automatic removal of residues on the inner wall, preventing material accumulation, ensuring mixing uniformity and proportion accuracy, reducing the frequency of manual cleaning, and improving the continuous operation efficiency and hygiene standards of the equipment.

[0019] 3. This invention increases the rotational speed of the rotating column and stirring rod. At this time, the scraper block adheres tightly to the inner wall of the outer shell under the action of centrifugal force. When the scraper block passes the magnetic block, the magnetic block adheres tightly to the outer side of the scraper block under the action of magnetic force. Then, the magnetic block moves synchronously under the drive of the scraper block, and the baffle rotates under the drive of the magnetic block. At this time, the inner cavity closed by the baffle is opened, and the supplementary functional powder enters the interior of the outer shell from the storage tank along the conveying pipe. At the same time, the user can replace the powder in the storage tank according to different needs, thereby realizing the automatic replenishment of powder, maintaining a stable ratio during continuous operation, adapting to various process requirements, and improving the stability of the production process and the quality of finished products.

[0020] 4. The device of this invention is equipped with a secondary mixing and crushing process and a tertiary material electrostatic process. The entire process is interconnected, which realizes efficient and continuous conveying of powder, while preventing agglomeration and improving the stability of the production process and the quality of the finished product. In addition, the device has a simple structure, low manufacturing cost, and convenient maintenance.

[0021] 5. The present invention provides a powder feeding method for the device, which demonstrates the entire technical solution in a more detailed, complete and convincing manner, and provides technical guidance for those skilled in the art. Attached Figure Description

[0022] Figure 1 This is a three-dimensional structural diagram of the present invention; Figure 2 This is a cross-sectional view of the internal structure of the outer shell of the present invention; Figure 3 This is a partial structural diagram of the discharge pipe of the present invention; Figure 4 This is a partial structural diagram of the stirring rod of the present invention; Figure 5 This is a partial structural diagram of the friction roller II of the present invention; Figure 6 This is a cross-sectional schematic diagram of the internal structure of the stirring rod of the present invention; Figure 7 This is a partial structural diagram of the baffle of the present invention; Figure 8 This is a flowchart of the powder feeding method of the present invention.

[0023] in: 1. Outer shell; 2. Feed inlet; 3. Drive motor one; 4. Rotating column; 5. Stirring rod; 6. Discharge pipe; 7. Control valve; 8. Static generator; 9. Wire one; 10. Wire two; 11. Magnetic coil; 12. Friction assembly; 121. Drive motor II; 122. Friction roller I; 123. Transmission gear I; 124. Transmission gear II; 125. Friction roller II; 13. Tension spring; 14. Connecting rod; 15. Scraper block; 16. Storage bin; 17. Conveying pipe; 18. Baffle; 19. Return spring; 20. Magnetic block. Detailed Implementation

[0024] 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.

[0025] like Figures 1-4 As shown, this embodiment of the invention provides a powder feeding device and method for laser additive manufacturing, including a housing 1. A feed inlet 2 is fixedly connected to the upper side of the housing 1. A drive motor 3 is fixedly connected to the side wall of the housing 1. A rotating column 4 is connected to the output end of the drive motor 3. The rotating column 4 is rotatably connected to the outside of the housing 1. A stirring rod 5 is fixedly connected to the outside of the rotating column 4. A discharge pipe 6 is fixedly connected to the inside of the housing 1. A control valve 7 is fixedly connected to the inside of the discharge pipe 6. An electrostatic generator 8 is fixedly connected to the side wall of the housing 1. A wire 9 is electrically connected to the outside of the electrostatic generator 8. A second wire 10 is electrically connected to the outside of the electrostatic generator 8. One end of the second wire 10 is electrically connected to a magnetic coil 11. The magnetic coil 11 is disposed inside the housing 1. A friction assembly 12 is disposed on the side wall of the housing 1.

[0026] Specifically, firstly, powder is fed into the interior of the outer shell 1 through the feed inlet 2. Then, the drive motor 3 is started to drive the rotating column 4 to rotate inside the outer shell 1. Since the rotating column 4 is fixedly connected to the stirring rod 5, the stirring rod 5 rotates synchronously under the drive of the rotating column 4. Subsequently, the stirring rod 5 performs preliminary crushing and friction on the powder stored inside the outer shell 1. At this time, the powder becomes initially charged under the friction with the stirring rod 5. After the rotating column 4 has been running for a certain period of time, the electrostatic generator 8 is turned on and supplies power to the discharge pipe 6 through the wire 9. At the same time, the electrostatic generator 8 supplies power to the magnetic coil 11 embedded inside the outer shell 1 through the wire 10. Then, the upper side of the outer shell 1... The stored powder comes into contact with the discharge pipe 6 and becomes charged. At the same time, the powder particles come into contact with each other to transfer static electricity, and the magnetic coil 11 generates a magnetic field after being energized. At this time, the control valve 7 is opened, causing the powder to fall to the lower side of the outer shell 1. Simultaneously, the friction component 12 is activated to perform secondary friction and break up the powder, preventing the powder from agglomerating. At this time, the powder is sprayed out of the outer shell 1 at high speed under its own weight and the magnetic field generated by the magnetic coil 11. This can achieve the effect of refining the powder, improving the dispersion uniformity, and using electrostatic adsorption and magnetic field guidance to achieve efficient and continuous conveying of powder, while preventing agglomeration and improving the stability of the production process and the quality of the finished product.

[0027] like Figure 5 As shown, the friction assembly 12 includes a second drive motor 121, the output end of which is connected to a first friction roller 122. A first transmission gear 123 is fixedly connected to the outside of the first friction roller 122. The teeth of the first transmission gear 123 are meshed with a second transmission gear 124. A second friction roller 125 is fixedly connected inside the second transmission gear 124. The second drive motor 121 is fixedly connected to the side wall of the outer casing 1, the second friction roller 125 is rotatably connected to the inside of the outer casing 1, and the first friction roller 122 is rotatably connected to the outside of the outer casing 1.

[0028] Specifically, the drive motor 121 is started to drive the friction roller 122 to rotate inside the outer shell 1. Then, the transmission gear 123 rotates synchronously under the drive of the friction roller 122. Then, the transmission gear 124 rotates synchronously under the drive of the transmission gear 123. Subsequently, the friction roller 125 rotates inside the outer shell 1 under the drive of the transmission gear 124. At this time, the powder is further crushed under the crushing of the friction roller 122 and the friction roller 125. At the same time, the powder is fully rubbed to ensure that all the powder is charged.

[0029] like Figure 2 As shown, one end of wire 19 is electrically connected to the inside of the discharge pipe 6, and the outside of wire 210 is set inside the outer casing 1.

[0030] Specifically, wire 9 is used to transfer the static electricity generated by the electrostatic generator 8 to the discharge pipe 6 for subsequent charging of the powder, while wire 10 is used to transfer the static electricity to the magnetic coil 11 to generate a directional magnetic field.

[0031] like Figure 2 , Figure 6 and Figure 7 As shown, a tension spring 13 is provided inside the stirring rod 5, and a connecting rod 14 is provided at one end of the tension spring 13. A scraper block 15 is fixedly connected to one end of the connecting rod 14. The outside of the connecting rod 14 is slidably connected to the inside of the stirring rod 5, and the outside of the scraper block 15 is provided inside the outer shell 1.

[0032] Specifically, by adjusting the power of the drive motor 3 to increase the rotation speed of the rotating column 4 and the stirring rod 5, the connecting rod 14 inside the stirring rod 5 undergoes centrifugal motion, that is, the connecting rod 14 slides inside the stirring rod 5 and drives the tension spring 13 to undergo elastic deformation. At the same time, the scraper block 15 moves synchronously under the drive of the connecting rod 14. Finally, the scraper block 15 adheres to the inner wall of the outer shell 1 and rotates along the inner side of the outer shell 1. At this time, the sharp edge of the scraper block 15 scrapes off the powder adhering to the side wall of the outer shell 1, thereby achieving the effect of automatically removing residues on the inner wall, preventing material accumulation, ensuring the uniformity of mixing and the accuracy of the proportion, while reducing the frequency of manual cleaning and improving the continuous operation efficiency and hygiene standards of the equipment.

[0033] like Figure 2 , Figure 6 and Figure 7 As shown, a storage box 16 is fixedly connected to the outside of the outer shell 1, and a conveying pipe 17 is provided inside the storage box 16. The outside of the conveying pipe 17 is located inside the outer shell 1. A baffle 18 is slidably connected inside the outer shell 1, and a return spring 19 is provided inside the outer shell 1. One end of the return spring 19 is located outside the baffle 18, and a magnetic block 20 is fixedly connected to the outside of the baffle 18. The magnetic block 20 is composed of magnetic material.

[0034] Specifically, by adjusting the power of the drive motor 3 to increase the rotation speed of the rotating column 4 and the stirring rod 5, the scraper block 15 approaches the magnetic block 20 under the action of centrifugal force. Since the scraper block 15 is made of metal, when it passes the magnetic block 20, if the speed of the drive motor 3 is between 0-100 rad / s, the scraper block 15 will not move outwards; if the speed of the drive motor 3 is between 100-200 rad / s, the scraper block 15 moves slightly outwards, magnetically attracting the magnetic block 20, but not contacting it, and the baffle 18 partially opens to slightly release material; if the speed of the drive motor 3 is between 200-300 rad / s, the scraper block 15 moves completely outwards, contacting the magnetic block 20. The magnetic block 20 is magnetically attracted and adheres tightly to the outside of the scraper block 15 under the action of magnetic force. Then, the magnetic block 20 moves synchronously under the drive of the scraper block 15. Subsequently, the baffle 18 rotates inside the outer shell 1 under the drive of the magnetic block 20. At this time, the inner cavity closed by the baffle 18 is opened, and the replenished functional powder falls from the storage box 16 into the cavity along the conveying pipe 17 and enters the interior of the outer shell 1 for replenishment, which can fully release the material. At the same time, the user can replace the powder inside the storage box 16 according to different needs, thereby realizing the automatic replenishment of powder, maintaining a stable ratio during continuous operation, adapting to various process requirements, and improving the stability of the production process and the quality of finished products.

[0035] like Figures 1-8 As shown, a powder feeding method for a laser additive manufacturing powder feeding device includes the following steps: S1. Feeding and preliminary mixing: Powder is fed into the shell 1 through the feed port 2. The drive motor 3 is started to drive the rotating column 4 and the stirring rod 5 to rotate, so as to initially disperse and rub the powder, and make the powder initially charged. S2. Electrostatic and magnetic field preparation: Turn on the electrostatic generator 8, and energize the discharge pipe 6 through the first wire 9. At the same time, power the magnetic coil 11 through the second wire 10 to generate a directional magnetic field. S3. Secondary friction and discharge control: Open the control valve 7 to make the powder fall, and simultaneously start the drive motor 121 of the friction assembly 12. The powder is subjected to secondary friction crushing through the meshing rotation of the friction roller 122 and the friction roller 125. S4. Magnetic field guided powder spraying: The powder is accelerated and sprayed out under the combined action of gravity and magnetic field; S5. Self-cleaning control: Increase the speed of the drive motor 13 and use centrifugal force to make the scraper block 15 rotate tightly against the inner wall of the outer shell 1 to remove the attached powder. S6. Automatic material replenishment control: When the scraper block 15 passes the magnetic block 20, the magnetic force attracts the baffle 18 to open the conveying pipe 17, thereby realizing the automatic replenishment of powder in the storage box 16.

[0036] Working principle: Powder is fed into the shell 1 through the feed inlet 2. The drive motor 3 is started to drive the rotating column 4 and the stirring rod 5 fixed on it to rotate, which initially disperses and rubs the powder, so that it is charged with static charge. Then, the electrostatic generator 8 is started. On the one hand, the discharge pipe 6 is charged through the wire 9, so that the powder in contact with it is charged. On the other hand, the magnetic coil 11 is powered through the wire 10, so that it generates a directional magnetic field inside the shell 1. During the powder conveying and acceleration stage, the control valve 7 is opened to allow the initially charged powder to fall, and the friction assembly 12 is activated at the same time. The drive motor 121 drives the friction roller 122 to rotate. Through the meshing of the transmission gear 123 and the transmission gear 124, the friction roller 125 is driven to rotate in the opposite direction, which performs secondary crushing and friction on the falling powder to ensure that the powder is fully charged and further refined. Finally, under the guidance of its own gravity and the magnetic field generated by the magnetic coil 11, the powder is accelerated and concentrated and sprayed out of the device at high speed, achieving stable and uniform conveying. In addition, the device also integrates automatic cleaning and replenishment functions; when cleaning is required, the speed of the drive motor 3 is increased, and the connecting rod 14 inside the stirring rod 5 drives the scraper block 15 to move close to the inner wall of the outer shell 1 under the action of centrifugal force, scraping off residual powder; when the metal scraper block 15 passes the magnetic block 20, the magnetic attraction will drive the baffle 18 to rotate against the elastic force of the return spring 19, thereby opening the channel of the conveying pipe 17, realizing the automatic replenishment of powder in the storage box 16. After completion, the baffle 18 is reset and closed under the action of the return spring 19.

[0037] In the description of this invention, the terms "upper," "lower," "front," "rear," "left," "right," "top," "bottom," "vertical," and "horizontal," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only to describe the invention and not to require the invention to be constructed or operated in a specific orientation; therefore, they should not be construed as limitations on the invention. The terms "connected" and "linked" in this invention should be interpreted broadly. For example, they can refer to a connection or a detachable connection; they can refer to a direct connection or an indirect connection through intermediate components. Those skilled in the art can understand the specific meaning of the above terms based on the specific circumstances.

[0038] The above description represents the preferred mode of operation of the present invention. The specific operational modes are provided solely for a better understanding of the invention's concept. Those skilled in the art can make various improvements or equivalent substitutions based on the principles of this invention, and these improvements or equivalent substitutions are also considered to fall within the scope of protection of this invention.

Claims

1. A powder feeding device for laser additive manufacturing, characterized in that, The device includes a housing (1), with a feed inlet (2) fixedly connected to the upper side of the housing (1), a drive motor (3) fixedly connected to the side wall of the housing (1), a rotating column (4) connected to the output end of the drive motor (3), the outside of the rotating column (4) being rotatably connected to the inside of the housing (1), a stirring rod (5) fixedly connected to the outside of the rotating column (4), a discharge pipe (6) fixedly connected to the inside of the housing (1), a control valve (7) fixedly connected to the inside of the discharge pipe (6), an electrostatic generator (8) fixedly connected to the side wall of the housing (1), a wire (9) electrically connected to the outside of the electrostatic generator (8), a wire (10) electrically connected to the outside of the electrostatic generator (8), a magnetic coil (11) electrically connected to one end of the wire (10), the outside of the magnetic coil (11) being disposed inside the housing (1), and a friction assembly (12) disposed on the side wall of the housing (1). The stirring rod (5) is provided with a tension spring (13) inside. One end of the tension spring (13) is provided with a connecting rod (14). One end of the connecting rod (14) is fixedly connected to a scraping block (15). The outside of the connecting rod (14) is slidably connected to the inside of the stirring rod (5). The outside of the scraping block (15) is provided inside the outer shell (1). A storage box (16) is fixedly connected to the outside of the outer shell (1). A conveying pipe (17) is provided inside the storage box (16). The outside of the conveying pipe (17) is located inside the outer shell (1). A baffle (18) is slidably connected inside the outer shell (1). A return spring (19) is provided inside the outer shell (1). One end of the return spring (19) is located outside the baffle (18). A magnetic block (20) is fixedly connected to the outside of the baffle (18). The magnetic block (20) is composed of magnetic material. When the rotational speed v of the first drive motor (3) is in the range of 0 rad / s ≤ v < 100 rad / s, the scraper block (15) does not move outward; when the rotational speed v of the first drive motor (3) is in the range of 100 rad / s ≤ v < 200 rad / s, the scraper block (15) moves slightly outward and magnetically attracts the magnetic block (20) so that the baffle (18) is partially opened; when the rotational speed v of the first drive motor (3) is in the range of 200 rad / s ≤ v ≤ 300 rad / s, the scraper block (15) moves completely outward and magnetically attracts the magnetic block (20), the magnetic block (20) moves with the scraper block (15) and drives the baffle (18) to rotate so that the material conveying pipe (17) fully discharges material.

2. The powder feeding device for laser additive manufacturing according to claim 1, characterized in that, The friction assembly (12) includes a second drive motor (121), the output end of which is connected to a first friction roller (122), a first transmission gear (123) is fixedly connected to the outside of the first friction roller (122), the teeth of the first transmission gear (123) are meshed with a second transmission gear (124), and a second friction roller (125) is fixedly connected inside the second transmission gear (124).

3. The powder feeding device for laser additive manufacturing according to claim 2, characterized in that, The second drive motor (121) is externally fixedly connected to the side wall of the outer shell (1), the second friction roller (125) is externally rotatably connected to the inside of the outer shell (1), and the first friction roller (122) is externally rotatably connected to the outside of the outer shell (1).

4. The powder feeding device for laser additive manufacturing according to claim 1, characterized in that, One end of the first wire (9) is electrically connected to the inside of the discharge pipe (6), and the outside of the second wire (10) is disposed inside the outer shell (1).

5. A powder feeding method for a powder feeding device in laser additive manufacturing, characterized in that, A powder feeding device for laser additive manufacturing according to any one of claims 1-4, comprising the following steps: S1. Feeding and preliminary mixing: The powder is fed into the shell (1) through the feed port (2), and the drive motor (3) is started to drive the rotating column (4) and the stirring rod (5) to rotate, so as to initially disperse and rub the powder, and make the powder initially charged; S2. Electrostatic and magnetic field preparation: Turn on the electrostatic generator (8), and energize the discharge pipe (6) through the first wire (9). At the same time, supply power to the magnetic coil (11) through the second wire (10) to generate a directional magnetic field. S3, Secondary Friction and Discharge Control: Open the control valve (7) to make the powder fall, and simultaneously start the second drive motor (121) of the friction assembly (12). The powder is subjected to secondary friction crushing through the meshing rotation of the first friction roller (122) and the second friction roller (125). S4. Magnetic field guided powder spraying: The powder is accelerated and sprayed out under the combined action of gravity and magnetic field; S5. Self-cleaning control: Increase the speed of the drive motor (3) and use centrifugal force to make the scraper block (15) rotate tightly against the inner wall of the outer shell (1) to remove the attached powder. S6. Automatic material replenishment control: When the scraper block (15) passes the magnetic block (20), the magnetic force attracts the baffle (18) to open the conveying pipe (17), thereby realizing the automatic replenishment of powder in the storage box (16).

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