Irregular double-scale powder continuous and uniform feeding device and method for additive manufacturing

Abstract

The invention belongs to the technical field of powder feeding type additive manufacturing, and provides a solution for continuous and uniform conveying of micro-nano powder with poor fluidity and irregular-shaped powder. The device comprises a case control cabinet, a powder storage bin, a grading conveying belt, an airflow generating device and a powder equalizer. An integrated control system is arranged in the case control cabinet and is used for controlling the whole powder feeding process; the two powder storage bins are fixed to one side of the machine box control cabinet and used for storing different types of powder for additive materials. The grading conveying belt is responsible for conveying different types of powder for additive materials to the airflow generation device, and the airflow generation device reduces agglomeration and adhesion of the powder through the blowing-away effect and blows the powder into the powder equalizer; and the powder equalizer is mounted right above the airflow generating device and is used for uniformly mixing different types of powder. The negative pressure system is used for conveying the evenly mixed powder to the additive manufacturing area through the powder feeding pipe, the powder and a high-energy heat source are converged to form a molten pool, the powder conveying continuity and uniformity are effectively improved, and the device is suitable for various additive manufacturing processes.

Description

Technical Field

[0001] The invention relates to the technical field of additive manufacturing, in particular to a continuous and uniform powder supply technology for micro-nano ceramic powders with poor fluidity and other irregularly shaped powders. Background Art

[0002] Additive manufacturing technology is one of the most advanced and promising manufacturing technologies. This technology can directly form three-dimensional parts or large structural parts by adding materials layer by layer, and can also repair defective parts. It has the advantages of high material utilization and high design freedom. In the field of high-performance and high-precision additive manufacturing, micro-nano powder additive manufacturing is gradually increasing, and it is necessary to ensure the continuity and uniformity of powder feeding, which poses a challenge to the traditional powder feeding system.

[0003] For micro-nano ceramic powders and other irregularly shaped powders, due to their extremely small particles, large specific surface area, and strong van der Waals and electrostatic forces between particles, the powders are prone to agglomeration, which leads to poor powder fluidity. In traditional powder feeding systems, this agglomeration phenomenon will make it difficult to discharge the powder or even completely block the powder feeding pipeline, affecting the continuity and uniformity of the powder supply, and may eventually lead to interruption or failure of the printing process.

[0004] Therefore, we propose a device and method for continuous and uniform feeding of irregular dual-scale powders for additive manufacturing to solve the problems mentioned in the background technology. Summary of the invention

[0005] The purpose of the present invention is to provide a device and method for continuous and uniform feeding of irregular dual-scale powders for additive manufacturing, so as to solve the continuity and uniformity problems encountered in the powder feeding process of micro-nano ceramic powders and other irregularly shaped powders in the prior art.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A continuous and uniform powder feeding device for irregular dual-scale powder for additive manufacturing, comprising a chassis cabinet control cabinet, an integrated control system is installed on one side of the chassis control cabinet, and a powder storage bin is fixed on the other side. A multi-stage conveyor belt is installed below the powder storage bin, an airflow generating device is arranged at the end of the multi-stage conveyor belt, and a powder balancer is arranged above the airflow generating device. The multi-stage conveyor belt is used to accurately control the powder feeding amount per minute, the airflow generating device is used to blow away agglomerated and adhered micro-nano powders, and convey the powder to the powder balancer, and the powder balancer is used to mix different types of additive powders evenly, and finally the mixed powder is transported to the additive area through a powder conveying pipe through a negative pressure system, and converged with a high-energy heat source to form a molten pool.

[0008] In one possible implementation, the powder storage bin includes a powder bin cover, a powder bin sealing cover is threadedly installed on the top of the powder bin cover, an external vibration pump is bolted on the top of the powder bin sealing cover, the vibration pump includes an adjustable vibration frequency controller to adapt to powders of different types and particle sizes, an air pressure balance valve is installed on one side of the powder bin cover, the powder bin cover is connected to the powder storage tank by three long screws, and an O-ring is used to enhance the sealing performance, the inner wall of the powder storage tube is coated with anti-sticking material to reduce powder adhesion, the powder storage tank is connected to the discharge funnel by screws, the discharge funnel is positioned with the lower support seat by four locating pins, and the support seat is threadedly installed on the top of the base.

[0009] In one possible implementation, the multi-stage conveyor belt includes a primary conveyor belt and a secondary conveyor belt. The primary conveyor belt is installed directly below the discharge funnel, and the secondary conveyor belt is installed between the primary conveyor belt and the airflow generating device. The conveyor belt is driven by a linearly adjustable speed motor, and the motor speed is adjusted by an integrated control system.

[0010] In one possible implementation, the airflow generating device includes a feed port, a conical feeding funnel is installed inside the feed port, four blowers are installed below the conical feeding funnel and driven by a linearly adjustable speed motor, a sleeve is installed above the conical feeding funnel, an O-ring is installed above the sleeve to ensure the seal between the airflow generating device and the powder balancer, a coordination key is installed on one side of the sleeve to ensure the correct relative position of the airflow generating device and the powder balancer, and the high-speed airflow generated by the blower in the airflow generating device can effectively blow away the agglomerated powder to ensure the continuity of the powder feeding process.

[0011] In one possible implementation, the powder balancer includes an upper cavity, which is connected to the lower cavity by 8 bolts, a powder uniformity sensor is installed on the top of the upper cavity, a transverse airflow intake valve is installed on one side of the lower cavity by a thread, and the transverse airflow intake valve is used to introduce high-speed inert gas into the transverse airflow annular air inlet duct, and 6 transverse airflow nozzles are evenly distributed above the transverse airflow annular air inlet duct, and the transverse airflow nozzle is controlled by an internal micro-motor and can rotate 360° along its own axis, and a vertical airflow intake valve is installed on the other side of the lower cavity by a thread, and the vertical airflow intake valve is used to introduce high-speed inert gas into the vertical airflow annular air inlet duct, and 16 annularly distributed vertical airflow nozzles are installed above the vertical airflow annular air inlet duct, and the bottom of the lower cavity is connected to a powder delivery port by a thread, and the powder delivery port includes an adjustable valve to control the flow rate and delivery speed of the powder, and a circular powder screen is arranged above the powder delivery port, and the uniformity of the mixed powder is ensured by the special structure of the powder balancer and the stirring action of the transverse airflow nozzle and the vertical airflow nozzle.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] The continuous and uniform powder feeder for micro-nano powder for additive manufacturing is composed of a chassis cabinet control cabinet, a powder storage bin, a multi-stage conveyor belt, an airflow generating device, and a powder balancer.

[0014] The chassis control cabinet is used to install and fix the remaining four modules, and control the operation of the powder feeder through the built-in integrated control system. The powder storage bin is used to store different types of powders for additive manufacturing to prevent the powder from moisture or contamination.

[0015] The multi-stage conveyor belt includes a primary conveyor belt and a secondary conveyor belt. The primary conveyor belt is installed directly below the discharge funnel, and the secondary conveyor belt is installed between the primary conveyor belt and the airflow generating device. The conveyor belt is driven by a linearly adjustable speed motor, and the motor speed is adjusted through an integrated control system to accurately control the powder delivery amount per minute.

[0016] The airflow generating device is located at the end of the secondary conveyor belt, with a conical feeding funnel installed inside. Four blowers are installed below the conical feeding funnel and driven by a linearly adjustable speed motor. The blowers in the airflow generating device can effectively disperse the agglomerated powder to ensure the continuity of the powder feeding process.

[0017] The powder balancer is located directly above the airflow generator, and contains 6 circularly distributed horizontal airflow nozzles and 16 circularly distributed vertical airflow nozzles. When the airflow generator sends the blown powder into the powder balancer, the special structure of the powder balancer and the stirring effect of the horizontal and vertical airflow nozzles are used to ensure the uniformity of the mixed powder. Finally, the uniformized powder is delivered to the molten pool through the powder delivery port with adjustable flow. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall structure of a continuous and uniform powder feeding device for irregular dual-scale powder for additive manufacturing of the present invention;

[0019] Figure 2 It is a cross-sectional view of the overall structure of an irregular dual-scale powder continuous and uniform powder feeding device for additive manufacturing of the present invention;

[0020] Figure 3 It is a structural schematic diagram of the airflow generating device in the present invention;

[0021] Figure 4 is a structural cross-sectional view of the powder balancer of the present invention;

[0022] Figure 5 It is a partial structural cross-sectional view of the powder balancer of the present invention;

[0023] In the figure: 1. Chassis control cabinet; 101. Integrated control system; 2. Powder storage bin; 201. External vibration pump; 202. Air pressure balance valve; 203. Powder bin sealing cover; 204. O-ring; 205. Powder bin cover; 206. Long screw; 207. Powder storage tank; 208. Positioning pin; 209. Support seat; 210. Base; 211. Screw; 212. Feeding hopper; 3. Multi-stage conveyor belt; 301. Primary conveyor belt; 302. Secondary conveyor belt; 4. Airflow generating device; 401. Feeding port; 402. Conical feeding funnel bucket; 403, blower; 404, speed linear adjustable motor; 405, sleeve; 406, coordination key; 407, O-ring; 5, powder balancer; 501, upper cavity; 502, bolt; 503, lower cavity; 504, horizontal air flow annular inlet; 505, horizontal air flow nozzle; 506, powder uniformity sensor; 507, vertical air flow nozzle; 508, horizontal air flow inlet valve; 509, powder delivery port; 510, circular powder screen; 511, vertical air flow inlet valve; 512, vertical air flow annular inlet; DETAILED DESCRIPTION

[0024] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0026] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0028] The following is a further introduction to the device in conjunction with the figures and embodiments. Figure 1 to Figure 5 The present embodiment provides a device and method for continuous and uniform feeding of irregular dual-scale powders for additive manufacturing, which is used for continuous and uniform feeding of micro-nano ceramic powders with poor fluidity and other irregularly shaped powders.

[0029] like Figures 1-2 As shown, the continuous and uniform powder feeder for micro-nano powder for additive manufacturing includes a cabinet control cabinet 1, a powder storage bin 2, a multi-stage conveyor belt 3, an airflow generating device 4, and a powder balance 5. An integrated control system 101 is installed on one side of the cabinet control cabinet 1, and a powder storage bin 2 is fixed on the other side. The multi-stage conveyor belt 3 is installed below the powder storage bin, and an airflow generating device 4 is arranged at the end of the multi-stage conveyor belt 3. A powder balancer 5 is arranged just above the airflow generating device 4.

[0030] like Figure 2 As shown, the powder storage bin includes a powder bin cover 205, a powder bin sealing cover 203, an external vibration pump 201, an air pressure balance valve 202, a powder storage tank 207, a discharge funnel 212, and a support seat 209, wherein the powder bin sealing cover 203 is connected to the top of the powder bin cover 205 by threads, the external vibration pump 201 is installed on the top of the powder bin sealing cover 203 by bolts, the air pressure balance valve 202 is installed on one side of the powder bin cover 205, the powder bin cover 205 is connected to the powder storage tank 207 by three long screws 206, and the sealing is enhanced by an O-ring 204, the powder storage tank 207 is connected to the discharge funnel 212 by screws, the discharge funnel 212 is positioned with the support seat 209 below by a positioning pin 208, and the support seat 209 is installed on the base 210 by threads.

[0031] like Figure 3 As shown, the airflow generating device 4 includes a feed port 401, a loading funnel 402, a blower 403, and a matching sleeve 405, wherein the conical loading funnel 402 is installed inside the feed port 401, four blowers 403 are installed below the conical loading funnel 402 and driven by a speed linear adjustable motor 404, a key 406 matching sleeve 405 is installed above the conical loading funnel 402 to ensure the correct relative position relationship between the airflow generating device and the powder balancer, and an O-ring 407 is installed above the sleeve to ensure the sealing between the airflow generating device and the powder balancer.

[0032] like Figures 4-5As shown, the powder balancer 5 includes an upper cavity 501, a lower cavity 503, a powder uniformity sensor 506, a transverse airflow inlet valve 508, a transverse airflow annular inlet duct 504, a transverse airflow nozzle 505, a vertical airflow inlet valve 511, a vertical airflow annular inlet duct 512, a vertical airflow nozzle 507, a powder delivery port 509, and a circular powder screen 510. The upper cavity 501 and the lower cavity 503 are connected by 8 bolts 502, 4 powder uniformity sensors 506 are installed on the top of the upper cavity 501, and a transverse airflow inlet valve 508 is installed on one side of the lower cavity 503 through a thread, which is used to introduce high-speed inert gas into the transverse airflow annular inlet duct 504, and a vertical airflow inlet valve 511 is installed on the other side of the lower cavity 503 through a thread, which is used to introduce high-speed inert gas into the vertical airflow annular inlet duct 512, and 16 annularly distributed vertical airflow nozzles 507 are installed above the vertical airflow annular inlet duct 512, and the bottom of the lower cavity 503 is connected to the powder delivery port 509 through a thread, and a circular powder screen 510 is arranged above the powder delivery port 509.

[0033] In this embodiment, when in use, the initial parameters of each mechanism are set through the integrated control system 101 on the chassis control cabinet 1, such as the vibration frequency of the external vibration pump 201, the speed of the first-stage conveyor belt 301 in the multi-stage conveyor belt 3, the speed of the second-stage conveyor belt 302, the rotation speed of the blower 403 inside the airflow generating device 4, the flow rate and direction of the horizontal airflow nozzle 505 and the vertical airflow nozzle 507 inside the powder balancer 5, and the required powder delivery amount is set. Subsequently, different types of micro-nano powders for additive manufacturing are poured into the powder storage bin 2 after drying, and the powders are transported to the multi-stage conveyor belt 3 by the external vibration pump 201 and gravity. The multi-stage conveyor belt 3 is used to accurately control the powder feeding amount per minute, and the powders are transported to the airflow generating device 4. The blower 403 at the bottom of the airflow generating device 4 generates an upward high-speed airflow to blow away the agglomerated and adhered micro-nano powders to ensure the continuity of the powder feeding process. Subsequently, the powders are blown into the powder balancer 5. The horizontal airflow nozzle 505 and the vertical airflow nozzle 507 in the powder balancer 5 respectively spray high-speed inert gas in two directions to promote full mixing between the powders. At the same time, the powder uniformity sensor 506 dynamically senses the uniformity of the internal powder and feeds back to the integrated control system 101. The integrated control system 101 adaptively adjusts the speed of the multi-stage conveyor belt 3, the airflow generating device 4 and the airflow intensity inside the powder balancer 5 in real time to further optimize the powder uniformity effect. When the powder uniformity reaches the powder delivery requirement, the powder uniformity sensor 506 feeds back information to the integrated control system 101, opens the valve on the powder delivery port 509, and delivers the mixed powder to the additive area through the powder delivery pipe.

[0034] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A continuous and uniform powder feeding device for irregular dual-scale powder for additive manufacturing, comprising a chassis control cabinet (1), one side of the chassis control cabinet (1) is equipped with an integrated control system for controlling the entire powder feeding process, and the other side is fixed with a powder storage bin (2) for storing different types of additive powders, a multi-stage conveyor belt (3) is installed below the powder storage bin (2) for conveying the powder in the powder storage bin (2) to an airflow generating device (4), an airflow generating device (4) is arranged at the end of the multi-stage conveyor belt (3) for blowing away agglomerated and adhered powders and blowing the powders to a powder balancer (5), a powder balancer (5) is arranged above the airflow generating device (4) for mixing different types of additive powders uniformly, and finally, through a negative pressure system, the mixed powder is conveyed to the additive area through a powder conveying pipe, and converged with a high-energy heat source to form a molten pool.

2. The device for continuous and uniform feeding of irregular dual-scale powder for additive manufacturing according to claim 1, characterized in that: The powder storage bin (2) comprises a powder bin cover (205), a powder bin sealing cover (203) is screwed on the top of the powder bin cover (205), an external vibration pump (201) is bolted on the top of the powder bin sealing cover (203), the external vibration pump (201) comprises an adjustable vibration frequency controller to adapt to powders of different types and particle sizes, an air pressure balance valve (202) is installed on one side of the powder bin cover, and the powder bin cover (205) is connected to the powder bin cover by three long screws. The screw (206) is connected to the powder storage tank (207), and the sealing is enhanced by using an O-ring (204). The inner wall of the powder storage tank (207) is coated with an anti-sticking material to reduce powder adhesion. The powder storage tank (207) is connected to the discharge funnel (212) by means of screws (211). The discharge funnel (212) is positioned with the support seat (209) below by means of four positioning pins (208). The support seat (209) is installed on the top of the base (210) by means of threads.

3. The device for continuous and uniform feeding of irregular dual-scale powder for additive manufacturing according to claim 1, characterized in that: The multi-stage conveyor belt (3) comprises a primary conveyor belt (301) and a secondary conveyor belt (302), wherein the primary conveyor belt (301) is installed directly below the discharge hopper (212), and the secondary conveyor belt (302) is installed between the primary conveyor belt (301) and the airflow generating device (4), and the conveyor belt is driven by a linearly adjustable speed motor, and the motor speed is adjusted by an integrated control system.

4. The device for continuous and uniform feeding of irregular dual-scale powder for additive manufacturing according to claim 1, characterized in that: The airflow generating device (4) comprises a feed port (401), a conical feeding funnel (402) is installed inside the feed port, four blowers (403) are installed below the conical feeding funnel and driven by a speed-adjustable linear motor (404), a sleeve (405) is installed above the conical feeding funnel, an O-ring (407) is installed above the sleeve (405) to ensure the seal between the airflow generating device (4) and the powder balancer (5), a coordination key (406) is installed on one side of the sleeve (405) to ensure the correct relative position of the airflow generating device (4) and the powder balancer (5), and the high-speed airflow generated by the blower (403) in the airflow generating device (4) effectively breaks up the agglomerated and adhered powder through the impact and shearing effect on the powder, thereby ensuring the continuity of the powder feeding process.

5. The device for continuous and uniform feeding of irregular dual-scale powder for additive manufacturing according to claim 1, characterized in that: The powder balancer (5) comprises an upper cavity (501), wherein the upper cavity (501) is connected to a lower cavity (503) via eight bolts (502), four powder uniformity sensors (506) are installed on the top of the upper cavity (501), a transverse airflow inlet valve (508) is installed on one side of the lower cavity (503) via a thread, and the transverse airflow inlet valve (508) is used to introduce high-speed inert gas into the transverse airflow annular inlet duct (504), six transverse airflow nozzles (505) are evenly distributed above the transverse airflow annular inlet duct (504), and the transverse airflow nozzles (505) are controlled by an internal micro-motor and can rotate 360° along their own axis, and the other side of the lower cavity (503) is connected to the lower cavity (503). A vertical airflow inlet valve (511) is installed through a thread, and the vertical airflow inlet valve (511) is used to introduce high-speed inert gas into the vertical airflow annular inlet duct (512). 16 annularly distributed vertical airflow nozzles (507) are installed above the vertical airflow annular inlet duct. The bottom of the lower cavity (503) is connected to a powder delivery port (509) through a thread. The powder delivery port (509) includes an adjustable valve to control the flow rate of the powder. A circular powder screen (510) is arranged above the powder delivery port (509). The uniformity of the mixed powder is ensured by the special structure of the powder balancer (5) and the stirring action of the transverse airflow nozzle (505) and the vertical airflow nozzle (507).

6. A method for using a continuous and uniform powder feeding device for irregular dual-scale powders for additive manufacturing, characterized in that: The continuous and uniform powder feeder for micro-nano powder for additive manufacturing is completed by using the device according to any one of claims 1 to 5. The method for using the continuous and uniform powder feeder for micro-nano powder for additive manufacturing comprises the following steps: Step 1: After drying, different types of additive manufacturing powders are loaded into the powder storage bin (2). According to the characteristics of the selected powder, adjust the vibration frequency of the external vibration pump (201) to ensure that the powder can flow smoothly. Then, turn on the power switch on the chassis control cabinet (1) and start the integrated control system (101). Set the required powder delivery amount, transverse airflow and longitudinal airflow flow (the equipment allows a gas flow adjustment range of 0 to 30L / min), and blower speed and other parameters through the control panel, and complete the setting of other related parameters. After confirming that the motors of each part are operating normally, press the "Start" button to start the entire powder delivery process; Step 2: The powder falls from the powder storage bin (2) onto the primary conveyor belt (301) via the discharge hopper (212), and is then transported to the secondary conveyor belt (302). The secondary conveyor belt (302) transports the powder to the airflow generating device (4). The airflow generating device (4) uses the airflow generated by the blower (403) to blow away the agglomerated or adhered micro-nano powders. The processed powder is sent to the powder balancer (5) for full mixing. Step 3: In the powder balancer (5), the horizontal airflow nozzle (505) and the vertical airflow nozzle (507) respectively spray high-speed inert gas in two directions to promote sufficient mixing between the powders. At the same time, the powder uniformity sensor (506) dynamically senses the uniformity of the internal powder and feeds back to the integrated control system (101). The integrated control system (101) adaptively adjusts the speed of the multi-stage conveyor belt (3), the airflow generating device (4) and the airflow intensity inside the powder balancer (5) in real time to further optimize the powder uniformity effect; Step 4: When the powder uniformity meets the powder delivery requirement, the powder uniformity sensor (506) feeds back information to the integrated control system (101), opens the valve on the powder delivery port (509), and delivers the mixed powder to the additive area through the powder delivery pipe.

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