A metering powder feeding device for low-flowability powder additive manufacturing

Abstract

This utility model provides a quantitative powder supply device for low-flowability powder additive manufacturing, relating to additive manufacturing, including: a powder hopper; a powder mixing box with a horizontally arranged mixing shaft inside; a powder dropping box with an upper powder inlet at the top, a horizontally arranged powder dropping shaft in the middle, and a lower powder outlet at the bottom, the upper powder inlet and the lower powder outlet being eccentrically arranged relative to the axis of the powder dropping shaft, the powder dropping shaft having multiple powder dropping grooves on its surface, the powder dropping shaft rotating to fill the powder dropping grooves with powder at the lower end of the upper powder inlet and release powder at the upper end of the lower powder outlet; and an air curtain nozzle with multiple air jet holes, capable of simultaneously spraying air into the powder dropping grooves rotated to the upper end of the lower powder outlet. The beneficial effects of this utility model: the pulsed gas sprayed from the air curtain nozzle is injected into the powder dropping grooves, achieving complete stripping of residual powder in the powder dropping grooves, ensuring that the transported powder falls completely, precisely controlling the powder dropping amount, and solving the problems of agglomeration and unstable powder supply during long-term static placement of low-flowability powder.

Description

Technical Field

[0001] This utility model relates to the field of additive manufacturing technology, and in particular to a quantitative powder supply device for low-flowability powder additive manufacturing. Background Technology

[0002] In metal additive manufacturing systems, the powder feeding device, as a key functional module for achieving uniform distribution and precise supply of powder materials, directly determines the quality stability and production economy of the formed parts. Among these, top-feed powder feeding technology, with its compact structure and high compatibility with powder circulation systems, has become the mainstream automated powder feeding solution. However, this technology has significant technical bottlenecks: its powder feeding mechanism based on the powder dropper roller is highly dependent on the powder flow characteristics, and when handling low-flow-rate powder materials (typically aluminum alloy powder), it is prone to decreased powder feeding stability. Currently, the industry commonly uses integrated powder bed monitoring systems as a quality control method, but this solution is significantly insufficient in controlling the uniformity of powder feeding when dealing with low-flow-rate powder conditions. More importantly, the incremental powder feeding process strategy adopted to maintain basic powder feeding continuity inevitably leads to a significant decrease in powder material utilization. Utility Model Content

[0003] In view of this, in order to solve the problems of insufficient powder supply stability and insufficient control effect of powder supply uniformity in existing powder feeding devices for processing low-flowability powders, the present invention provides a quantitative powder feeding device for additive manufacturing of low-flowability powders.

[0004] An embodiment of this utility model provides a quantitative powder feeding device for low-flowability powder additive manufacturing, comprising:

[0005] The powder silo has a feed inlet at the top and a discharge outlet at the bottom.

[0006] A powder mixing box has openings at both the top and bottom. The top of the powder mixing box is connected to the discharge port of the powder hopper. A horizontally arranged stirring shaft is provided inside the powder mixing box. The stirring shaft extends along the length of the powder mixing box. A powder mixing drive mechanism is provided at one end of the powder mixing box. The powder mixing drive mechanism is connected to the stirring shaft to drive the stirring shaft to rotate.

[0007] A powder dispensing box is fixedly connected to the lower end of the powder mixing box. The powder dispensing box has an upper powder inlet at the top, a horizontally arranged powder dispensing shaft in the middle, and a lower powder outlet at the bottom. The upper powder inlet and the lower powder outlet are eccentrically arranged relative to the axis of the powder dispensing shaft. The upper end of the upper powder inlet communicates with the bottom of the powder mixing box, and the lower end of the lower powder outlet extends out of the powder dispensing box. The upper powder inlet, the lower powder outlet, and the powder dispensing shaft are of the same length and parallel to each other. The surface of the powder dispensing shaft has multiple spaced powder dispensing grooves. Each powder dispensing groove is arranged along the length direction of the powder dispensing shaft and its width gradually increases as it moves away from the axis of the powder dispensing shaft. One end of the powder dispensing box is provided with a powder dispensing drive mechanism. The powder dispensing drive mechanism is connected to the powder dispensing shaft to drive the powder dispensing shaft to rotate, so that the powder dispensing groove is filled with powder at the lower end of the upper powder inlet and released with powder at the upper end of the lower powder outlet.

[0008] And an air curtain nozzle, which is disposed on the outside of the powder falling shaft and along the length of the powder falling shaft. The air curtain nozzle is provided with multiple air jet holes, each of which faces the surface of the powder falling shaft, and can simultaneously spray air into the powder falling groove that has rotated to the upper end of the lower powder outlet.

[0009] Furthermore, the powder mixing box and the powder dropping box are rectangular boxes of the same length, the lower end of the powder mixing box overlaps and is connected to the upper end of the powder dropping box, and the length of the upper powder inlet is the same as the length of the stirring shaft.

[0010] Furthermore, both the upper powder inlet and the lower powder outlet are vertically arranged rectangular channels, and the upper powder inlet and the lower powder outlet are respectively located on opposite sides of the powder falling shaft axis.

[0011] Furthermore, it also includes an air reservoir and multiple solenoid valves, each of which is connected to the air reservoir, and each of the air jets is connected to a solenoid valve via an air delivery pipe.

[0012] Furthermore, the solenoid valve is a pulse solenoid valve.

[0013] Furthermore, the powder-discharging groove is an arc-shaped groove with a central angle of less than 180 degrees, and each of the powder-discharging grooves is evenly spaced around the axis of the powder-discharging shaft.

[0014] Furthermore, the powder box has a cylindrical powder feeding cavity in the middle, and the powder feeding shaft is rotatably installed in the powder feeding cavity, with the outer wall of the powder feeding shaft fitting against the inner wall of the powder feeding cavity.

[0015] Furthermore, the length of the air curtain nozzle is the same as the length of the powder dropper, and each of the air jet holes is evenly spaced on the air curtain nozzle.

[0016] Furthermore, the surface of the stirring shaft is provided with stirring columns, which are evenly distributed across the surface of the stirring shaft.

[0017] Furthermore, both the powder stirring drive mechanism and the powder dropping drive mechanism are belt drive mechanisms.

[0018] The beneficial effects of the technical solution provided by the embodiments of this utility model are as follows:

[0019] 1. This utility model discloses a quantitative powder supply device for additive manufacturing of low-flowability powder. First, the powder in the powder hopper is stirred by a stirring shaft to prevent the powder from clumping when it is stationary. Then, the powder is transported through a powder dropper on the surface of the powder dropper shaft. When the powder moves to the lower powder outlet, it is sprayed through an air curtain nozzle. By controlling the air jet in the powder dropper and the rotation angle of the powder dropper shaft, the pulse gas ejected from the air curtain nozzle can be accurately sprayed into the powder dropper, effectively achieving complete removal of residual powder in the powder dropper and ensuring that the transported powder falls completely, thus ensuring the stability of the powder supply process. Moreover, the amount of powder transported in each powder dropper is fixed, so the amount of powder dropped can be precisely controlled to achieve precise quantitative powder supply. This improves the problem of decreased flowability caused by easy clumping of materials when the upper powder dropper is in a stationary state when processing low-flowability powder, and effectively improves the uniformity and stability of powder supply in the upper powder dropper system under low-flowability powder conditions.

[0020] 2. This utility model discloses a quantitative powder supply device for low-flowability powder additive manufacturing. The upper powder inlet and the lower powder outlet are eccentrically arranged relative to the powder discharge shaft axis. When the powder discharge shaft rotates and the powder discharge trough has not moved to the lower powder outlet, the lower powder outlet is sealed by the surface of the powder discharge shaft and no powder is discharged. When the powder discharge trough moves to the lower powder outlet, the lower powder outlet is aligned with the powder discharge shaft, causing the lower powder outlet to open and discharge powder. This allows for accurate control of the amount of powder discharged, improving powder utilization efficiency. Furthermore, compared with other sealing methods, this sealing structure effectively reduces the complexity of the assembly process while ensuring sealing performance, significantly improving the stability and reliability of equipment operation. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a quantitative powder supply device for low-flowability powder additive manufacturing according to the present invention;

[0022] Figure 2 This is a cross-sectional view of a quantitative powder supply device for low-flowability powder additive manufacturing according to this utility model;

[0023] Figure 3 This is a cross-sectional view of the bottom of a quantitative powder feeding device for low-flowability powder additive manufacturing according to this utility model.

[0024] Figure 4 This is a schematic diagram of the stirring shaft;

[0025] Figure 5This is a schematic diagram of the powder-dropping roller;

[0026] Figure 6 This is a side view of the powder-falling axis;

[0027] Figure 7 This is a schematic diagram of an air curtain nozzle.

[0028] In the diagram: 1. Powder hopper; 2. Powder mixing box; 3. Powder dropping box; 4. Air curtain nozzle; 5. Stirring shaft; 6. Powder dropping shaft; 7. Powder dropping drive mechanism; 8. Powder mixing drive mechanism; 9. Second synchronous pulley; 10. Second synchronous belt; 11. First synchronous pulley; 12. First synchronous belt; 13. Air tank; 14. Solenoid valve; 15. Air supply pipe; 16. Upper powder inlet; 17. Lower powder outlet; 18. Air jet hole; 19. Stirring column; 20. Powder dropping trough; 21. Feed inlet; 22. Discharge outlet. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this utility model clearer, the embodiments of this utility model will be further described below with reference to the accompanying drawings. The following description presents a preferred embodiment of several possible embodiments of this utility model, intended to provide a basic understanding of the utility model, but not intended to identify the key or decisive elements of the utility model or to limit the scope of protection sought.

[0030] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0031] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0032] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures. Also, it should be understood that, for ease of description, the dimensions of the various parts shown in the figures are not drawn to actual scale.

[0033] It should be noted that, unless otherwise explicitly specified and limited, the terms "installation" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0034] Please refer to Figure 1 , 2 According to embodiment 3, this utility model provides a quantitative powder supply device for low-flowability powder additive manufacturing, which is applied to the powder spreading process in additive manufacturing. It mainly includes a powder hopper 1, a powder stirring box 2, a powder dropping box 3, and an air curtain nozzle 4.

[0035] The powder hopper 1 has an inlet 21 at the top and an outlet 22 at the bottom, with an openable cover for the inlet 21. The powder hopper 1 is used to store powders required for additive manufacturing, such as aluminum alloy powder. The shape of the powder hopper 1 can be flexibly configured according to actual application scenarios. For example, in this embodiment, the powder hopper 1 is rectangular at the top and isosceles trapezoidal at the bottom, so that the powder stored in the powder hopper 1 flows downwards under the influence of gravity.

[0036] The powder mixing box 2 has openings at both the top and bottom. The upper end of the powder mixing box 2 is connected to the discharge port 22 of the powder hopper 1, so that the top of the powder mixing box 2 communicates with the discharge port 22 at the bottom of the powder hopper 1. A horizontally arranged stirring shaft 5 is provided inside the powder mixing box 2. The top of the powder mixing box 2 is fixedly connected to the bottom of the powder hopper 1 and the two are in communication with each other, so that the powder stored in the powder hopper 1 can flow into the top of the powder mixing box 2.

[0037] One end of the powder mixing box 2 is provided with a powder mixing drive mechanism 8. The powder mixing drive mechanism 8 is connected to the stirring shaft 5 to drive the stirring shaft 5 to rotate. The rotation of the stirring shaft 5 continuously stirs the powder entering the powder mixing box 2, preventing the powder in the powder mixing box 2 from clumping due to standing.

[0038] Combination Figure 4 As shown, in some embodiments, the surface of the stirring shaft 5 is provided with stirring columns 19. The stirring columns 19 are arranged radially along the stirring shaft 5. The stirring columns 19 cover the surface of the stirring shaft 5, and when the stirring shaft 5 rotates, each stirring column 19 stirs the powder, resulting in a good stirring effect. Here, in order to obtain a more uniform stirring effect, the stirring columns 19 are arranged in multiple rows along the length direction of the stirring shaft 5. Each row of stirring columns 19 is evenly spaced around the circumference of the stirring shaft 5, and adjacent rows of stirring columns 19 are evenly staggered along the length direction of the stirring shaft 5. The stirring columns 19, which are evenly distributed on the surface of the stirring shaft 5, continuously disturb the powder when rotating, effectively maintaining the discrete state characteristics of the powder inside the powder mixing box 2, thereby achieving long-term stable operation of the powder feeding device of the powder dropping box 3.

[0039] The powder dispensing box 3 is fixedly connected to the lower end of the powder mixing box 2. The powder dispensing box 3 has an upper powder inlet 16 at the top, a horizontally arranged powder dispensing shaft 6 in the middle, and a lower powder outlet 17 at the bottom. Here, the powder dispensing box 3 has a cylindrical powder feeding cavity in the middle, and the powder dispensing shaft 6 is rotatably installed in the powder feeding cavity, with the outer wall of the powder dispensing shaft 6 fitting against the inner wall of the powder feeding cavity. The upper powder inlet 16 and the lower powder outlet 17 are eccentrically arranged relative to the axis of the powder dispensing shaft 6. The upper end of the upper powder inlet 16 communicates with the bottom of the powder mixing box 2, and the lower end of the lower powder outlet 17 extends out of the powder dispensing box 3. The surface of the powder dispensing shaft 6 has a plurality of axially extending powder dispensing grooves 20 arranged at intervals. Each powder dispensing groove 20 is a groove arranged along the length direction of the powder dispensing shaft 6 and gradually increasing in width as it moves away from the axis of the powder dispensing shaft 6.

[0040] The top of the powder drop box 3 is fixedly connected to the bottom of the powder mixing box 2. The powder mixed in the powder mixing box 2 enters the powder drop box 3 through the upper powder inlet 16. When the stirring shaft 5 rotates, the powder drop trough 20 on its surface is opened when it moves to the upper powder inlet 16 and the lower powder outlet 17, and closed when it moves to the part outside the upper powder inlet 16 and the lower powder outlet 17.

[0041] The upper powder inlet 16, the lower powder outlet 17, and the powder dropping shaft 6 are of the same length and parallel to each other, so that the powder input by the upper powder inlet 16 falls evenly into the powder dropping groove 20 of the powder dropping shaft 6 and flows out evenly from the lower powder outlet 17.

[0042] The shapes of the powder mixing box 2 and the powder dropping box 3 can be flexibly set according to the actual application scenario. For example, in this embodiment, the powder mixing box 2 and the powder dropping box 3 are rectangular boxes with the same length. The lower end of the powder mixing box 2 overlaps and is connected to the upper end of the powder dropping box 3. The length of the upper powder inlet 16 is the same as the length of the stirring shaft 5, so that the powder can flow more smoothly from the powder mixing box 2 into the powder dropping box 3.

[0043] One end of the powder dispensing box 3 is provided with a powder dispensing drive mechanism 7, which is connected to the powder dispensing shaft 6 to drive the powder dispensing shaft 6 to rotate, so that the powder dispensing trough 20 is filled with powder at the lower end of the upper powder inlet 16 and releases powder at the upper end of the lower powder outlet 17. When the powder dispensing trough 20 rotates to the upper powder inlet 16, the powder entering through the upper powder inlet 16 flows into the powder dispensing trough 20. After leaving the upper powder inlet 16, the powder dispensing trough 20 is blocked by the inner wall of the powder dispensing box 3. When the powder dispensing trough 20 rotates to the lower powder outlet 17, it is opened, and the powder in the powder dispensing trough 20 flows out through the lower powder outlet 17.

[0044] The upper powder inlet 16 and the lower powder outlet 17 are eccentrically positioned relative to the axis of the powder dispensing shaft 6. This ensures that when the powder dispensing groove 20 of the powder dispensing shaft 6 does not move to the lower powder outlet 17, unexpected powder leakage from the powder dispensing box 3 will not occur. Alternatively, the upper powder inlet 16 and the lower powder outlet 17 can be positioned on opposite sides of the axis of the powder dispensing shaft 6 to further prevent unexpected powder leakage from the powder dispensing box 3.

[0045] In some embodiments, to ensure uniform powder distribution in the powder dispensing trough 20, both the upper powder inlet 16 and the lower powder outlet 17 are vertically arranged rectangular channels. Both the upper powder inlet 16 and the lower powder outlet 17 are arranged along the length of the powder dispensing shaft 6, i.e., along the length of the powder dispensing trough 20. This allows the powder to completely fill the powder dispensing trough 20 when it flows in through the upper powder inlet 16, and to flow uniformly downwards along the lower powder outlet 17 when it exits the trough 20, achieving uniform powder distribution and accurate control of the powder amount.

[0046] like Figure 5 and 6 As shown, the shape of the powder-discharging groove 20 can be flexibly set according to the actual powder discharging needs. For example, in this embodiment, the powder-discharging groove 20 is set as an arc-shaped groove with a central angle of less than 10 degrees along the length direction of the powder-discharging shaft 6. Furthermore, each of the powder-discharging grooves 20 is evenly spaced around the axis of the powder-discharging shaft 6.

[0047] During the rotation of the powder-feeding shaft 6, the powder-feeding trough 20 primarily functions as a powder transporter. Considering the need for a more uniform and stable distribution of powder discharge, effectively suppressing dust generation, the number of powder-feeding troughs 20 and the depth of each trough 20 are mutually constrained. To achieve a reasonable balance in process performance, preferably, the diameter of the powder-feeding trough 20 is %~% of the diameter of the powder-feeding shaft 6, and the number of powder-feeding troughs 20 is one. This maximizes the powder transport capacity while suppressing dust generation.

[0048] The powder stirring drive mechanism 8 and the powder falling drive mechanism 7 can be selected from various common rotary drive mechanisms. For example, in this embodiment, both the powder stirring drive mechanism 8 and the powder falling drive mechanism 7 are belt drive mechanisms. The powder stirring drive mechanism 8 includes a first motor, a first synchronous belt 12, and two first synchronous pulleys 11. The first synchronous belt 12 is tensioned and fitted onto the two first synchronous pulleys 11. One first synchronous pulley 11 is connected to the first motor, and the other first synchronous pulley 11 is connected to one end of the stirring shaft 5. Thus, the first motor can drive the first synchronous belt 12 to rotate, thereby rotating the stirring shaft 5. Similarly, the powder falling drive mechanism 7 includes a second motor, a second synchronous belt 10, and two second synchronous pulleys 9. The second synchronous belt 10 is tensioned and fitted onto the two second synchronous pulleys 9. One second synchronous pulley 9 is connected to the second motor, and the other second synchronous pulley 9 is connected to one end of the powder falling shaft 6. Thus, the second motor can drive the second synchronous belt 10 to rotate, thereby rotating the powder falling shaft 6.

[0049] like Figure 7 As shown, the air curtain nozzle 4 is disposed on the outside of the powder-falling shaft 6 and along the length of the powder-falling shaft 6. The air curtain nozzle 4 has multiple air jet holes 18, each of which faces the surface of the powder-falling shaft 6, and can simultaneously spray air into the powder-falling trough 20 that has rotated to the upper end of the lower powder outlet 17. The length of the air curtain nozzle 4 is the same as the length of the powder-falling trough 20, and the air jet holes 18 are evenly spaced on the air curtain nozzle 4, which can evenly spray powder into the powder-falling trough 20.

[0050] To address the technical challenges of feeding low-flow-rate metal powders during the rotation of the powder feeding shaft 6, when the powder feeding shaft 6 performs the powder feeding operation, the powder in the powder feeding trough 20 cannot fully flow freely due to its own weight when it rotates to the lower powder outlet 17, resulting in significant fluctuations in the powder supply. If secondary powder supply compensation is implemented through powder spreading detection, additional process time is required, leading to reduced production efficiency. However, in this application, when the powder feeding shaft 6 rotates and moves one of the powder feeding troughs 20 to the lower powder outlet 17, each of the air jet holes 18 simultaneously jets air into the powder feeding trough 20. Under the impact of the airflow, the powder in the powder feeding trough 20 is completely stripped off and flows out along the lower powder outlet 17.

[0051] Furthermore, in some embodiments, the low-flowability powder additive manufacturing quantitative powder supply device of this invention also includes an air reservoir 13 and multiple solenoid valves 14. The solenoid valves 14 are pulse solenoid valves, each connected to the air reservoir 13. Each jet nozzle 18 is connected to a pulse solenoid valve via a gas delivery pipe 15. The air reservoir 13 stores pressurized gas, such as argon in this embodiment. The gas delivery pipe 15 is a PU tube. The pulse solenoid valves can precisely control the opening and closing state of the gas delivery pipe 15, delivering the argon stored in the air reservoir 13 to the air curtain nozzle 4 via the gas delivery pipe 15. The jet nozzles 18 of the air curtain nozzle 4 are precisely aligned with the powder dropper trough 20 of the powder dropper shaft 6. By applying pulsed gas with specific pressure parameters and flow rate characteristics, the complete stripping of residual powder in the powder dropper trough 20 can be effectively achieved, thereby ensuring the stability of the powder supply process. The timing of the pulse solenoid valve's opening and closing and the control of the rotation angle of the powder-falling shaft 6 are used to ensure that the pulsed gas from the air curtain nozzle 4 can blow the powder into the powder-falling trough 20 each time.

[0052] In this invention, a quantitative powder supply device for low-flowability powder additive manufacturing involves the following steps during powder feeding: The powder stored in the powder hopper 1 enters the powder mixing box 2, and the rotation of the stirring shaft 5 continuously agitates the powder within the mixing box 2, preventing localized agglomeration. Subsequently, the powder in the mixing box 2 enters the powder dropping box 3 along the upper powder inlet 16. The rotation of the powder dropping shaft 6 moves the powder dropping groove 20 on its surface to the upper powder inlet 16, allowing the powder to enter the powder dropping groove 20. As the powder trough 20 moves from the upper powder inlet 16 to the lower powder outlet 17, the inner wall of the powder dropper 3 seals the powder-filled powder dropper 20. When the powder dropper 20 moves to the lower powder outlet 17, it is opened. At this time, air is sprayed into the powder dropper 20 through the air jet holes 18 of the air curtain nozzle 4, so that the residual powder in the powder dropper 20 is completely stripped off. All the powder in the powder dropper 20 flows out along the lower powder outlet 17, distributing powder to the printing area, realizing uniform powder drop and precise control of powder amount.

[0053] In this document, the directional terms such as front, back, top, and bottom are defined based on the position of the components in the accompanying drawings and their relative positions to each other, solely for the purpose of clarity and convenience in expressing the technical solution. It should be understood that these are relative concepts and can vary depending on different methods of use and placement; the use of these directional terms should not limit the scope of protection claimed in this application.

[0054] Where there is no conflict, the embodiments and features described above can be combined with each other. The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A low flowability powder additive manufacturing dosing device, characterized in that, include: The powder silo has a feed inlet at the top and a discharge outlet at the bottom. A powder mixing box has openings at both the top and bottom. The top of the powder mixing box is connected to the discharge port of the powder hopper. A horizontally arranged stirring shaft is provided inside the powder mixing box. The stirring shaft extends along the length of the powder mixing box. A powder mixing drive mechanism is provided at one end of the powder mixing box. The powder mixing drive mechanism is connected to the stirring shaft to drive the stirring shaft to rotate. A powder dispensing box is fixedly connected to the lower end of the powder mixing box. The powder dispensing box has an upper powder inlet at the top, a horizontally arranged powder dispensing shaft in the middle, and a lower powder outlet at the bottom. The upper powder inlet and the lower powder outlet are eccentrically arranged relative to the axis of the powder dispensing shaft. The upper end of the upper powder inlet communicates with the bottom of the powder mixing box, and the lower end of the lower powder outlet extends out of the powder dispensing box. The upper powder inlet, the lower powder outlet, and the powder dispensing shaft are of the same length and parallel to each other. The surface of the powder dispensing shaft has multiple spaced powder dispensing grooves. Each powder dispensing groove is arranged along the length direction of the powder dispensing shaft and its width gradually increases as it moves away from the axis of the powder dispensing shaft. One end of the powder dispensing box is provided with a powder dispensing drive mechanism. The powder dispensing drive mechanism is connected to the powder dispensing shaft to drive the powder dispensing shaft to rotate, so that the powder dispensing groove is filled with powder at the lower end of the upper powder inlet and released with powder at the upper end of the lower powder outlet. And an air curtain nozzle, which is disposed on the outside of the powder falling shaft and along the length of the powder falling shaft. The air curtain nozzle is provided with multiple air jet holes, each of which faces the surface of the powder falling shaft, and can simultaneously spray air into the powder falling groove that has rotated to the upper end of the lower powder outlet.

2. A low flow powder additive manufacturing dosing device as claimed in claim 1, characterized in that: The powder mixing box and the powder dropping box are rectangular boxes of the same length. The lower end of the powder mixing box overlaps and is connected to the upper end of the powder dropping box. The length of the upper powder inlet is the same as the length of the stirring shaft.

3. A low flow powder additive manufacturing dosing device as claimed in claim 1, characterized in that: Both the upper powder inlet and the lower powder outlet are vertically arranged rectangular channels, and the upper powder inlet and the lower powder outlet are respectively located on opposite sides of the powder falling shaft axis.

4. A low flow powder additive manufacturing dosing device as claimed in claim 1, characterized in that: It also includes an air tank and multiple solenoid valves, each of which is connected to the air tank, and each of the jet holes is connected to a solenoid valve through an air supply pipe.

5. A low flow powder additive manufacturing dosing device as claimed in claim 4, wherein: The solenoid valve is a pulse solenoid valve.

6. A low flow powder additive manufacturing dosing device as claimed in claim 1, characterized in that: The powder-dropping groove is an arc-shaped groove with a central angle of less than 180 degrees, and each of the powder-dropping grooves is evenly spaced around the axis of the powder-dropping shaft.

7. A low flow powder additive manufacturing dosing device as claimed in claim 1, characterized in that: The powder box has a cylindrical powder feeding cavity in the middle, and the powder feeding shaft is rotatably installed in the powder feeding cavity, with the outer wall of the powder feeding shaft fitting against the inner wall of the powder feeding cavity.

8. A low flow powder additive manufacturing dosing device as claimed in claim 1, characterized in that: The length of the air curtain nozzle is the same as the length of the powder dropper, and each of the air jet holes is evenly spaced on the air curtain nozzle.

9. A low flow powder additive manufacturing dosing device as claimed in claim 1, wherein: The surface of the stirring shaft is provided with stirring columns, which are evenly distributed across the surface of the stirring shaft.

10. The low-flowability powder additive manufacturing quantitative powder feeding device as described in claim 1, characterized in that: Both the powder stirring drive mechanism and the powder dropping drive mechanism are belt drive mechanisms.

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