Powder feeding mechanism, additive manufacturing device and feeding method

Abstract

The invention relates to the technical field of additive manufacturing, and particularly discloses a powder feeding mechanism, an additive manufacturing device and a feeding method.In the powder feeding mechanism, a hopper is arranged on a base in a sliding mode, the hopper is provided with a material containing cavity, a feeding port and a discharging port, the feeding port and the discharging port communicate with the material containing cavity, and powder can enter the material containing cavity from the feeding port and can flow out from the discharging port; the driving assembly is arranged on the base, the output end of the driving assembly is in transmission connection with the hopper so as to drive the hopper to move, and strip-shaped powder piles are left on the forming platform. The discharging port is located above the forming platform, the distance between the discharging port and the forming platform is H1, the height of the powder pile is H2, and H1 is larger than or equal to H2. By means of the arrangement, powder is saved, the situation of incomplete melting is avoided, and the quality of printed pieces can be guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of additive manufacturing, and in particular to a powder supply mechanism, an additive manufacturing device and a feeding method. Background Art

[0002] Electron beam powder-laying additive manufacturing uses electron beams to selectively melt metal powder particles (hereinafter referred to as powder) in a specific area on a powder forming platform, thereby achieving the manufacture of metal three-dimensional entities. The quality of the powder laying largely determines the quality of the printed part. The current equipment mainly uses a powder rolling trough and a powder rolling shaft to convey the powder to the forming platform to form a long strip of powder, and then cooperates with a scraper to turn the powder and lay the powder in layers on the forming platform.

[0003] Since the powder is fluid and is affected by the precision of the powder rolling groove and the powder rolling shaft during the process of being transported to the forming platform, the powder content is uneven along the length of the powder pile. In addition, when the scraper hits and turns the powder, the scraper is tilted due to resistance, and the turned over powder further increases the unevenness. If the powder content in a part of the powder pile is small, the scraper may cause local or large-area powder shortage during the powder scraping process. In order to avoid this powder shortage, a powder rolling shaft with a large rotation angle is usually used to deliver powder, which leads to reduced powder utilization and increased costs. At the same time, due to the excessive powder content in various parts of the powder pile, the scraper pushes too much powder, and the scraper bends and deforms, the forming platform will appear wavy, the powder layer is too thick, resulting in poor melting, and the printed parts will have quality defects such as stratification.

[0004] Therefore, it is urgent to study a powder supply mechanism, an additive manufacturing device and a feeding method to solve the above problems. Summary of the invention

[0005] The object of the present invention is to provide a powder supply mechanism, an additive manufacturing device and a feeding method to solve the problems of increased cost and reduced print quality in the prior art.

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

[0007] The powder supply mechanism comprises:

[0008] Base;

[0009] A hopper is slidably disposed on the base, the hopper having a material holding cavity and an inlet and an outlet communicating with the material holding cavity, and powder can enter the material holding cavity from the inlet and flow out from the outlet;

[0010] A driving assembly is arranged on the base, and an output end of the driving assembly is connected to the hopper to drive the hopper to move and leave a strip-shaped powder pile on the forming platform;

[0011] The discharge port is located above the molding platform, and the distance between the discharge port and the molding platform is H1, the height of the powder pile is H2, and H1≥H2.

[0012] As an optional technical solution for a powder feeding mechanism, the base includes a guide rail and two brackets, the drive assembly is arranged on the bracket, and the hopper is slidably arranged on the guide rail; wherein, the guide rail includes a guide groove with an opening facing downward, and each opposite side of the guide groove is provided with a limiting protrusion, and the hopper includes a hopper body and a first guide member, the first guide member includes a first guide body and a first limiting portion arranged at the upper end of the first guide body, the outer diameter of the first limiting portion is larger than the distance between the two limiting protrusions and smaller than the width of the guide groove, and the first limiting portion is slidably arranged in the guide groove.

[0013] As an optional technical solution of the powder supply mechanism, the hopper further includes a blocking member, the material containing cavity is provided in the hopper body, the blocking member is provided in the hopper body and can block the discharge port to prevent the powder from flowing out, or open the discharge port; and / or,

[0014] 1.5*H2>H1≥H2.

[0015] As an optional technical solution for a powder supply mechanism, the blocking member is slidably disposed inside the bucket body and can slide between a blocking position and an avoidance position; the blocking member includes a blocking body and a second guide member connected to the blocking body, and the second guide member is slidably disposed in the guide rail.

[0016] As an optional technical solution for a powder feeding mechanism, the second guide member includes a guide cross bar, a guide vertical bar vertically connected to the guide cross bar, and a second limiting portion arranged at the top end of the guide vertical bar, the outer diameter of the second limiting portion is larger than the outer diameter of the guide vertical bar; the bucket body has a guide channel connected to the material holding cavity, the guide vertical bar is inserted into the guide channel, and the second limiting portion is slidably arranged in the guide groove, the limiting protrusion has a recessed portion, and when the second limiting portion is located in the recessed portion, the sealing body blocks the discharge port.

[0017] As an optional technical solution for a powder feeding mechanism, two guide rails are provided, and the two guide rails are arranged at intervals in a direction perpendicular to their own extension. The blocking member has two guide vertical rods, and the hopper includes four first guide members, wherein one guide rail corresponds to one guide vertical rod and two first guide members, and the other guide rail corresponds to one guide vertical rod and two first guide members; the guide vertical rod corresponding to the same guide rail is located between the two first guide members; along the extension direction of the guide rail, the length of the recessed portion is L1, the distance between the two first limit portions in one guide rail is L2, and the distance between the two first limit portions in the other guide rail is L3, wherein L2>L1, L3>L1+L2.

[0018] As an optional technical solution for a powder supply mechanism, the sealing body includes a sealing rod and a sealing head, and the outer diameter of the sealing head is larger than the outer diameter of the sealing rod; wherein, the end of the sealing head facing the discharge port is a conical sealing portion, the bottom of the material containing cavity is conical, and the taper of the sealing portion is the same as the taper of the bottom of the material containing cavity.

[0019] As an optional technical solution for a powder feeding mechanism, the driving assembly includes a driving member, a screw and a nut. The driving member is arranged on the base, the screw is rotatably arranged on the base and is transmission-connected to the driving member, and the nut is threadably matched with the screw and is fixedly connected to the hopper; the rotation process of the screw can drive the nut to move along the axial direction of the screw.

[0020] An additive manufacturing device comprises a vacuum chamber, a feed pipe, a molding platform and the powder supply mechanism described in any of the above technical solutions, wherein the molding platform and the powder supply mechanism are both located in the vacuum chamber, the vacuum chamber has a feed channel, the feed pipe is sealed and penetrates the feed channel, one end of the feed pipe is connected to the feed inlet, and the other end extends out of the vacuum chamber.

[0021] A feeding method, applied to the powder feeding mechanism described in any one of the above technical solutions, comprises the following steps:

[0022] The scraper moves to one side of the molding platform in the length direction; the hopper moves from one side of the molding platform in the width direction to the other side and then stops. During the movement of the hopper, the powder flows out from the discharge port to the molding platform and forms a powder pile; after the hopper stops, the powder continues to flow out and covers the discharge port, and the powder stops flowing out; the scraper moves to the other side of the molding platform in the length direction to spread the powder on the molding platform; the hopper moves in the opposite direction to form a powder pile on the molding platform, and the scraper moves in the opposite direction to spread the powder pile on the molding platform.

[0023] The present invention has at least the following beneficial effects:

[0024] The present invention provides a powder supply mechanism, an additive manufacturing device and a feeding method. The powder supply mechanism comprises a base and a hopper arranged on the base. The hopper has a material holding cavity and an inlet and an outlet connected to the material holding cavity. The powder can flow out from the outlet at a uniform speed. Under the driving action of a driving component, the hopper is driven to move, so that the powder can be evenly spread on a forming platform. The structure of the outlet is simple, and the accuracy is easy to ensure. It is not affected by the accuracy of a powder rolling groove and a powder rolling shaft. It is easier to ensure that the powder content at various locations along the length direction of the powder pile is the same. The powder is then flattened by a scraper to form a powder layer of uniform thickness on the forming platform. The thickness of the powder layer after flattening will not be too thick, so powder is saved and there will be no incomplete melting, which is beneficial to ensuring the quality of the printed part.

[0025] In addition, the discharge port is located above the molding platform, and the distance between the discharge port and the molding platform is H1, the height of the powder pile is H2, H1 ≥ H2, so that when the hopper stops at the end of the powder pile, the powder continues to flow and accumulates and is higher than the discharge port, thereby blocking the discharge port to avoid further leakage. The structure is simple, and the above-mentioned height limit ensures the smoothness of the discharge. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the contents of the embodiments of the present invention and these drawings without paying any creative work.

[0027] Figure 1 It is a structural schematic diagram of a powder material supply mechanism in an embodiment of the present invention;

[0028] Figure 2 It is a structural side view of the powder supply mechanism in the embodiment of the present invention;

[0029] Figure 3 for Figure 2 The enlarged view of point A in the middle;

[0030] Figure 4 It is a structural schematic diagram of a base and a hopper in an embodiment of the present invention;

[0031] Figure 5 It is a cross-sectional view of the base and the hopper in an embodiment of the present invention;

[0032] Figure 6 is a cross-sectional view of the base and the hopper in an embodiment of the present invention, including a blocking member;

[0033] Figure 7 A schematic diagram of the cooperation between the recessed portion of the guide rail and the blocking member in an embodiment of the present invention;

[0034] Figure 8 1 is a top view of the guide rail and the hopper in the embodiment of the present invention.

[0035] In the figure:

[0036] 1000, powder pile;

[0037] 100, base; 110, guide rail; 111, guide groove; 112, limiting protrusion; 113, recessed portion; 120, bracket;

[0038] 200, hopper; 210, hopper body; 211, material holding chamber; 212, material outlet; 213, first guide member; 2131, first guide body; 2132, first position limiting portion; 220, blocking member; 221, blocking body; 2211, blocking rod; 2212, blocking head; 222, second guide member; 2221, guide cross bar; 2222, guide vertical bar; 2223, second position limiting portion;

[0039] 300, driving assembly; 310, screw rod; 320, nut;

[0040] 400, scraper; 500, forming platform; 510, platform body; 520, bearing member; 600, feeding pipe. DETAILED DESCRIPTION

[0041] Before any embodiments of the application are explained in detail, it is to be understood that the application is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the above drawings.

[0042] In this application, the terms "comprises", "includes", "has" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of more restrictions, an element defined by the sentence "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device that includes the element.

[0043] In this application, the term "and / or" is a description of the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects before and after are in an "and / or" relationship.

[0044] In the present application, the terms "connect", "combine", "couple", and "install" may refer to direct connection, combination, coupling, or installation, or indirect connection, combination, coupling, or installation. For example, direct connection refers to two parts or components being connected together without the need for an intermediate piece, and indirect connection refers to two parts or components being connected to at least one intermediate piece respectively, and the two parts or components being connected via the intermediate piece. In addition, "connect" and "couple" are not limited to physical or mechanical connections or couplings, and may include electrical connections or couplings.

[0045] In this application, it will be understood by those of ordinary skill in the art that relative terms (e.g., "about," "approximately," "substantially," etc.) used in conjunction with quantities or conditions include the values ​​and have the meaning indicated by the context. For example, the relative terms include at least the degree of error associated with the measurement of a specific value, the tolerances caused by manufacturing, assembly, and use associated with a specific value, etc. Such terms should also be considered to disclose a range defined by the absolute values ​​of the two endpoints. Relative terms may refer to plus or minus a certain percentage (e.g., 1%, 5%, 10% or more) of the indicated value. Numerical values ​​that do not use relative terms should also be disclosed as specific values ​​with tolerances. In addition, "substantially" may refer to plus or minus a certain degree (e.g., 1 degree, 5 degrees, 10 degrees or more) on the basis of the indicated angle when expressing a relative angular position relationship (e.g., substantially parallel, substantially perpendicular).

[0046] In this application, it will be understood by those skilled in the art that the function performed by a component can be performed by one component, multiple components, one part, or multiple parts. Similarly, the function performed by a part can also be performed by one part, one component, or a combination of multiple parts.

[0047] In the present application, the terms "upper", "lower", "left", "right", "front", "back" and other directional words are described based on the orientation and positional relationship shown in the accompanying drawings, and should not be understood as limiting the embodiments of the present application. In addition, in the context, it is also necessary to understand that when it is mentioned that an element is connected to another element "upper" or "lower", it can not only be directly connected to another element "upper" or "lower", but also indirectly connected to another element "upper" or "lower" through an intermediate element. It should also be understood that directional words such as upper side, lower side, left side, right side, front side, back side, etc. not only represent the positive orientation, but can also be understood as the lateral orientation. For example, the bottom can include directly below, lower left, lower right, lower front, and lower back, etc.

[0048] like Figures 1 to 8As shown, this embodiment provides a powder material supply mechanism, which includes a base 100, a hopper 200 and a driving assembly 300. The hopper 200 is slidably arranged on the base 100, and the hopper 200 has a material holding cavity 211 and an inlet and an outlet 212 connected to the material holding cavity 211. The powder material can enter the material holding cavity 211 from the inlet and can flow out from the outlet 212; the driving assembly 300 is arranged on the base 100, and the output end is transmission-connected with the hopper 200 to drive the hopper 200 to move and leave a strip-shaped powder pile 1000 on the forming platform 500; the outlet 212 is located above the forming platform 500, and the distance between the outlet 212 and the forming platform 500 is H1, and the height of the powder pile 1000 is H2, 1.1*H2>H1≥H2.

[0049] The above arrangement enables the powder to flow out from the discharge port 212 at a uniform speed. Under the driving action of the driving assembly 300, the hopper 200 is driven to move, so that the powder can be evenly laid on the forming platform 500. The discharge port 212 has a simple structure, and the accuracy is easy to ensure. It is not affected by the accuracy of the powder rolling groove and the powder rolling shaft, making it easier to ensure that the powder content is the same at various locations along the length direction of the powder pile 1000. The powder is then flattened by the scraper 400 to form a powder layer of uniform thickness on the forming platform 500. The thickness of the powder layer after flattening will not be too thick, saving powder, and there will be no incomplete melting, which is conducive to ensuring the quality of the printed part. Among them, the driving structure of the scraper 400 is well known to those skilled in the art and will not be described in detail here.

[0050] In addition, combined Figure 3 As shown, the discharge port 212 is located above the forming platform 500, and the distance between the discharge port 212 and the forming platform 500 is H1, and the height of the strip powder pile 1000 is H2, 1.1*H2>H1≥H2, so that when the hopper 200 stops at the end of the powder pile 1000, the powder continues to flow and accumulates and is higher than the discharge port 212, thereby blocking the discharge port 212 to avoid further leakage. The structure is simple, and the above-mentioned height limit can avoid wasting powder.

[0051] In some embodiments, in combination Figure 5As shown, the base 100 includes a guide rail 110 and a bracket 120, the drive assembly 300 is arranged on the bracket 120, and the hopper 200 is slidably arranged on the guide rail 110; wherein, the guide rail 110 includes a guide groove 111 with an opening facing downward, and a limiting protrusion 112 is respectively provided on the opposite sides of the guide groove 111, and the hopper 200 includes a hopper body 210 and a first guide member 213, the first guide member 213 includes a first guide body 2131 and a first limiting portion 2132 arranged at the upper end of the first guide body 2131, the outer diameter of the first limiting portion 2132 is larger than the distance between the two limiting protrusions 112 and smaller than the width of the guide groove 111, the first limiting portion 2132 is slidably arranged in the guide groove 111, and is supported by the limiting protrusions 112 on both sides.

[0052] During the movement of the scraper 400, the hopper 200 can be moved upward to avoid interference with the scraper 400. In some embodiments, in order to improve work efficiency, the height between the hopper 200 and the molding platform 500 is set higher than the height of the scraper 400. However, the higher the height of the hopper 200, the greater the demand for powder to block the discharge port 212, resulting in waste. In order to reduce the amount of powder, in some embodiments, combined with Figure 6 As shown, the hopper 200 includes a hopper body 210 and a blocking member 220, a material holding cavity 211 is provided in the hopper body 210, and the blocking member 220 is provided in the hopper body 210, and can block the discharge port 212 to prevent the powder from flowing out, or open the discharge port 212. This arrangement allows the powder pile 1000 to be laid when the hopper body 210 moves to one end of the width direction of the forming platform 500. At this time, the blocking member 220 blocks the discharge port 212, thereby preventing the powder from continuing to flow out, reducing the amount of powder. Exemplarily, 1.5*H2>H1≥H2, which ensures the smooth movement of the scraper 400 and the smooth flow of the powder during the movement of the hopper 200.

[0053] To achieve the movement of the blocking member 220, in some embodiments, the blocking member 220 is slidably disposed inside the bucket body 210 and can slide between a blocking position and an avoidance position; the blocking member 220 includes a blocking body 221 and a second guide member 222 connected to the blocking body 221, and the second guide member 222 is slidably disposed in the guide rail 110. In other embodiments, the blocking member 220 can also be swingably disposed inside the bucket body 210.

[0054] Specifically, combined Figure 6 and Figure 7The second guide member 222 includes a guide cross bar 2221, a guide vertical bar 2222 vertically connected to the guide cross bar 2221, and a second limiting portion 2223 arranged at the top of the guide vertical bar 2222, and the outer diameter of the second limiting portion 2223 is larger than the outer diameter of the guide vertical bar 2222; the bucket body 210 has a guide channel connected to the material holding cavity 211, the guide vertical bar 2222 is inserted into the guide channel, and the second limiting portion 2223 is slidably arranged in the guide groove 111, and the long strip-shaped limiting protrusion 112 extending in the left and right directions has a concave portion 113 concave downwardly, and when the second limiting portion 2223 is located at the concave portion 113, the blocking body 221 blocks the discharge port 212. In which, under the cooperation of the guide channel and the guide vertical bar 2222, the relative sliding of the blocking member 220 and the bucket body 210 is realized, and the sliding accuracy of the blocking member 220 can be guaranteed. In this embodiment, the outer diameter of the second limiting portion 2223 is smaller than the width of the guide groove 111 .

[0055] Furthermore, two sliding grooves extending in the vertical direction and opening opposite to each other are provided inside the bucket body 210, and the two ends of the guide crossbar 2221 are respectively slidably disposed in the corresponding sliding grooves. This arrangement can further ensure that the second guide member 222 will not deflect during the sliding process, thereby ensuring the trajectory and smoothness of the second limiter 2223 sliding in the guide groove 111.

[0056] Combination Figure 8As shown, in some embodiments, two guide rails 110 are provided, and the two guide rails 110 are arranged at intervals in a direction perpendicular to their own extension, the blocking member 220 has two guide vertical rods 2222, and the hopper 200 includes four first guide members 213, wherein one guide rail 110 corresponds to one guide vertical rod 2222 and two first guide members 213, and the other guide rail 110 corresponds to one guide vertical rod 2222 and two first guide members 213; the guide vertical rod 2222 corresponding to the same guide rail 110 is located between the two first guide members 213; along the extension direction of the guide rail 110, the length of the recessed portion 113 is L1, the distance between the two first limiting portions 2132 in one guide rail 110 is L2, and the distance between the two first limiting portions 2132 in the other guide rail 110 is L3, wherein L2>L1, L3>L1+L2. In other words, the two guide rails 110 are arranged at intervals in the front-to-back direction and both extend in the left-to-right direction. The hopper 200 can move in the left-to-right direction, and the scraper 400 can move in the front-to-back direction. The two second guide members 222 are arranged at intervals in the front-to-back direction. The above arrangement enables the hopper 200 to lay the powder on the forming platform 500 to form a powder pile 1000 during the movement. Before the powder pile 1000 is laid, the two first limiting portions 2132 in one of the guide rails 110 are located on the same side of the recessed portion 113, the two first limiting portions 2132 in the other guide rail 110 are arranged on both sides of the recessed portion 113, and the two second limiting portions 2223 are respectively located outside the two recessed portions 113 in the two guide rails 110. When the powder pile 1000 is laid, the two first limit portions 2132 in one guide rail 110 are located on both sides of the recessed portion 113, the two first limit portions 2132 in the other guide rail 110 are also located on both sides of the recessed portion 113, and the two second limit portions 2223 are respectively located in the two recessed portions 113 in the two guide rails 110. This arrangement allows the hopper 200 to be guided by the four first limit portions 2132. Before the powder pile 1000 is about to be laid, one of the first limit portions 2132 passes over the recessed portion 113. During this process, the cooperation of the three first limit portions 2132 and the two guide rails 110 can still ensure the smooth movement of the hopper 200.

[0057] The sealing body 221 includes a sealing rod 2211 and a sealing head 2212. The outer diameter of the sealing head 2212 is larger than the outer diameter of the sealing rod 2211 so as to minimize the volume of the sealing body 221 and reduce costs. The end of the sealing head 2212 facing the discharge port 212 is a conical sealing portion, and the bottom of the material holding chamber 211 is conical so as to ensure that all powder materials can flow out of the material holding chamber 211 smoothly. The taper of the sealing portion is the same as the taper of the bottom of the material holding chamber 211 so as to ensure the sealing effect on the discharge port 212.

[0058] The feed port is located directly above the discharge port 212 . To prevent the powder falling from the feed port from accumulating on the blocking head 2212 , in some embodiments, the end of the blocking head 2212 close to the blocking rod 2211 is a guide portion, and the diameter of the guide portion gradually increases in the direction close to the discharge port 212 .

[0059] In some embodiments, the feed port is located directly above the guide cross bar 2221, and the guide cross bar 2221 is a cylindrical structure, or the guide cross bar 2221 is an arched structure, that is, the middle part is high and the two sides are low, so as to avoid the accumulation of powder. In other embodiments, the guide cross bar 2221 can be set as an annular structure, so that the powder falling from the feed port directly passes through the annular interior of the guide cross bar 2221 and falls to the guide part.

[0060] In order to realize the driving of the hopper 200, in some embodiments, the driving assembly 300 includes a driving member, a screw rod 310 and a nut 320. The driving member is arranged on the base 100, the screw rod 310 is rotatably arranged on the base 100 and is in driving connection with the driving member, and the nut 320 is threadedly matched with the screw rod 310 and is fixedly connected to the hopper 200; the screw rod 310 can drive the nut 320 to move along the axis direction of the screw rod 310 during its rotation. The driving mode of the screw rod 310 and the nut 320 makes the hopper 200 move with high precision and has a self-locking function.

[0061] To facilitate assembly, in some embodiments, the base 100 includes two brackets 120 , the two brackets 120 are arranged at an interval, and both ends of the screw rod 310 are rotatably connected to the two brackets 120 .

[0062] The present embodiment also provides an additive manufacturing device, which includes a vacuum chamber, a feed pipe 600, a molding platform 500, a scraper 400, and a powder supply mechanism in any of the above embodiments, wherein the molding platform 500 and the powder supply mechanism are both located in the vacuum chamber, the vacuum chamber has a feed channel, the feed pipe 600 is sealed and penetrated in the feed channel, and one end is connected to the feed inlet, and the other end extends out of the vacuum chamber. The scraper 400 is movably arranged on the molding platform 500 in the front-to-back direction. The molding platform 500 includes a platform body 510, a bearing member 520, and a bearing drive member, wherein the platform body 510 has a printing channel extending in the up-and-down direction, the bearing member 520 is slidably arranged in the printing channel, and is used to carry powder and printed parts, and the bearing drive member is arranged on the platform body 510 and is transmission-connected to the bearing member 520.

[0063] The feeding tube 600 is a metal hose that can move with the hopper 200 and ensure that powder can be continuously supplied to the hopper 200. One end of the metal hose is connected to the hopper 200, and the other end is connected to the powder supply device. The powder supply device (powder box or external powder tank) can be installed outside the vacuum chamber, which is beneficial to reduce the volume and cost of the vacuum chamber; at the same time, it avoids the problem of poor powder quality caused by the change of the physical properties of the internal powder due to the long-term high temperature of the powder supply device inside the vacuum chamber, thereby ensuring the printing quality.

[0064] The present embodiment also provides a feeding method, which is applied to the powder feeding mechanism in the above embodiment, and includes the following steps: the scraper 400 moves to one side of the molding platform 500 in the length direction; the hopper 200 moves from one side of the molding platform 500 in the width direction to the other side and then stops, and during the movement of the hopper 200, the powder flows out from the discharge port 212 to the molding platform 500 and forms a powder pile 1000; after the hopper 200 stops, the powder continues to flow out and covers the discharge port 212 or the discharge port 212 is blocked by the blocking member 220, and the powder stops flowing out; the scraper 400 moves to the other side of the molding platform 500 in the length direction to spread the powder on the molding platform 500; the hopper 200 moves in the opposite direction to form a powder pile 1000 on the molding platform 500, and the scraper 400 moves in the opposite direction to spread the powder pile 1000 on the molding platform 500.

[0065] 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, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. 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 powder supply mechanism, characterized in that: include: Base (100); A hopper (200) is slidably disposed on the base (100), wherein the hopper (200) has a material holding cavity (211) and an inlet and an outlet (212) communicating with the material holding cavity (211), and powdered material can enter the material holding cavity (211) from the inlet and can flow out from the outlet (212); A driving assembly (300) is disposed on the base (100), and an output end thereof is drivingly connected to the hopper (200) to drive the hopper (200) to move and leave a strip-shaped powder pile on the forming platform (500); The discharge port (212) is located above the molding platform (500), and the distance between the discharge port (212) and the molding platform (500) is H1, the height of the powder pile is H2, and H1≥H2.

2. The powder supply mechanism according to claim 1, characterized in that: The base (100) comprises a guide rail (110) and two brackets (120), the driving assembly (300) is arranged on the bracket (120), and the hopper (200) is slidably arranged on the guide rail (110); wherein the guide rail (110) comprises a guide groove (111) opening downward, and opposite sides of the guide groove (111) are each provided with a limiting protrusion (112), and the hopper (200) comprises a hopper body (210) and a first guide member (213), the first guide member (213) comprises a first guide body (2131) and a first limiting portion (2132) arranged at the upper end of the first guide body (2131), the outer diameter of the first limiting portion (2132) is greater than the distance between the two limiting protrusions (112) and smaller than the width of the guide groove (111), and the first limiting portion (2132) is slidably arranged in the guide groove (111).

3. The powder supply mechanism according to claim 2, characterized in that: The hopper (200) further comprises a blocking member (220), the material containing cavity (211) is arranged in the hopper body (210), the blocking member (220) is arranged in the hopper body (210), and can block the material outlet (212) to prevent the powder from flowing out, or open the material outlet (212); and / or, 1.5*H2>H1≥H2.

4. The powder supply mechanism according to claim 3, characterized in that: The blocking member (220) is slidably disposed inside the bucket body (210) and is capable of sliding between a blocking position and an avoidance position; the blocking member (220) comprises a blocking body (221) and a second guide member (222) connected to the blocking body (221), and the second guide member (222) is slidably disposed in the guide rail (110).

5. The powder supply mechanism according to claim 4, characterized in that: The second guide member (222) comprises a guide cross bar (2221), a guide vertical bar (2222) vertically connected to the guide cross bar (2221), and a second limiting portion (2223) arranged at the top end of the guide vertical bar (2222), the outer diameter of the second limiting portion (2223) being greater than the outer diameter of the guide vertical bar (2222); the bucket body (210) has a guide channel connected to the material holding chamber (211), the guide vertical bar (2222) is inserted into the guide channel, and the second limiting portion (2223) is slidably arranged in the guide groove (111), the limiting protrusion (112) has a recessed portion (113), and when the second limiting portion (2223) is located in the recessed portion (113), the blocking body (221) blocks the material outlet (212).

6. The powder supply mechanism according to claim 5, characterized in that: The guide rails (110) are provided with two, and the two guide rails (110) are arranged at intervals in a direction perpendicular to the guide rails themselves. The blocking member (220) has two guide vertical rods (2222). The hopper (200) includes four first guide members (213), wherein one guide rail (110) corresponds to one guide vertical rod (2222) and two first guide members (213), and the other guide rail (110) corresponds to one guide vertical rod (2222) and two first guide members ( 213); the guide vertical rod (2222) corresponding to the same guide rail (110) is located between the two first guide members (213); along the extension direction of the guide rail (110), the length of the recessed portion (113) is L1, the distance between the two first limiting portions (2132) in one guide rail (110) is L2, and the distance between the two first limiting portions (2132) in the other guide rail (110) is L3, wherein L2>L1, L3>L1+L2.

7. The powder supply mechanism according to claim 4, characterized in that: The sealing body (221) comprises a sealing rod (2211) and a sealing head (2212), wherein the outer diameter of the sealing head (2212) is greater than the outer diameter of the sealing rod (2211); wherein, the end of the sealing head (2212) facing the discharge port (212) is a conical sealing portion, the bottom of the material holding chamber (211) is conical, and the taper of the sealing portion is the same as the taper of the bottom of the material holding chamber (211).

8. The powder supply mechanism according to claim 2, characterized in that: The driving assembly (300) comprises a driving member, a screw rod (310) and a nut (320); the driving member is arranged on the base (100); the screw rod (310) is rotatably arranged on the base (100) and is transmission-connected to the driving member; the nut (320) is threadably matched with the screw rod (310) and is fixedly connected to the hopper (200); the screw rod (310) can drive the nut (320) to move along the axial direction of the screw rod (310) during its rotation.

9. An additive manufacturing device, characterized in that It comprises a vacuum chamber, a feeding pipe (600), a molding platform (500) and a powder feeding mechanism as described in any one of claims 1 to 8, wherein the molding platform (500) and the powder feeding mechanism are both located in the vacuum chamber, the vacuum chamber has a feeding channel, the feeding pipe (600) is sealed and penetrated in the feeding channel, one end of the feeding pipe is connected to the feeding port, and the other end extends out of the vacuum chamber.

10. A feeding method, applied to the powder feeding mechanism according to any one of claims 1 to 8, characterized in that: The following steps are involved: The scraper (400) moves to one side of the molding platform (500) in the length direction; the hopper (200) moves from one side of the molding platform (500) in the width direction to the other side and then stops. During the movement of the hopper (200), the powder flows out from the discharge port (212) to the molding platform (500) and forms a powder pile; after the hopper (200) stops, the powder continues to flow out and covers the discharge port (212), and the powder stops flowing out; the scraper (400) moves to the other side of the molding platform (500) in the length direction to spread the powder on the molding platform (500); the hopper (200) moves in the reverse direction to form a powder pile on the molding platform (500), and the scraper (400) moves in the reverse direction to spread the powder pile on the molding platform (500).

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