Additive manufacturing circulating powder supply device and circulating powder supply method

Abstract

The invention relates to the technical field of additive manufacturing, and particularly discloses an additive manufacturing circulating powder supply device and a circulating powder supply method.In the additive manufacturing circulating powder supply device, powder can enter a powder feeding piece from a powder feeding inlet and flow out of the powder feeding piece from a powder feeding outlet; the forming platform is located in the vacuum chamber and used for bearing powder. The powder feeding piece is located above the forming platform and used for transferring powder. The powder spreading assembly is arranged below the powder feeding outlet and used for spreading the powder to the forming platform; the powder discharging piece is arranged below the forming platform, and the powder discharging piece is provided with a powder discharging inlet so as to collect redundant powder falling from the forming platform after powder laying is completed; the lifting assembly is provided with a lower lifting inlet and an upper lifting outlet, the lifting inlet is communicated with the powder discharging outlet of the powder discharging part, the lifting outlet is communicated with the powder feeding inlet of the powder feeding part, and the lifting assembly is used for lifting powder entering from the lifting inlet and enabling the powder to flow out from the lifting outlet. Through the arrangement, the printing cost is reduced, and the mechanical property of a printed piece is guaranteed.

Description

Technical Field

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

[0002] The characteristic of electron beam powder-laying additive manufacturing is that the electron beam is used to selectively melt the metal powder particles (referred to as powder) in a specific area on the molding platform, thereby realizing the manufacturing of metal three-dimensional entities.

[0003] Since the printing work is carried out in a high vacuum environment, and a powder box is set up to provide powder for printing. The excess powder scraped away by the scraper falls directly into the recycling box, the powder utilization is low, and the printing cost is high. In addition, when the vacuum is evacuated, the powder in the powder box is placed together and in close contact, which makes it difficult for the gas and water molecules between the powders to be extracted. After the powder is sent to the forming platform by the powder rolling shaft, the gas molecules are emitted, and at the same time, the water molecules are vaporized at high temperature, and react quickly with the powder at high temperature to produce oxygen, resulting in the mechanical properties of the printed part not meeting the requirements. Finally, after the printing is completed and the furnace is opened, the powder in the recycling box is screened outdoors, which is very easy to be oxidized, resulting in the mechanical properties of the printed part being affected when it is used again.

[0004] Therefore, it is urgent to study an additive manufacturing circulating powder supply device and a circulating powder supply method to solve the problems of low powder utilization efficiency and the inability to guarantee the mechanical properties of the printed parts. Summary of the invention

[0005] The purpose of the present invention is to provide an additive manufacturing circulating powder supply device and a circulating powder supply method to solve the problems in the prior art that the powder utilization efficiency is low and the mechanical properties of the printed parts cannot be guaranteed.

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

[0007] Additive manufacturing circulating powder supply device, comprising:

[0008] Vacuum chamber;

[0009] A forming platform, located in the vacuum chamber and used for carrying powder;

[0010] A powder loading part, located above the forming platform, is used for transferring powder;

[0011] A powder spreading component is provided below the powder feeding outlet of the powder feeding member and is used for spreading the powder material onto the forming platform;

[0012] A powder discharge piece is disposed below the forming platform, and has a powder discharge inlet for collecting excess powder falling from the forming platform after the powder spreading is completed, and has a powder discharge outlet for discharging the powder;

[0013] The lifting assembly has a lifting inlet at the bottom and a lifting outlet at the top. The lifting inlet is connected to the lower powder outlet of the lower powder piece, and the lifting outlet is connected to the upper powder inlet of the upper powder piece. The lifting assembly is used to lift the powder entering from the lifting inlet and let it flow out from the lifting outlet.

[0014] As an optional technical solution for an additive manufacturing circulating powder supply device, the lifting assembly includes a lifting cylinder and a spiral blade, the lifting inlet is arranged at the lower end of the lifting cylinder, the lifting outlet is arranged at the upper end of the lifting cylinder, and the spiral blade is rotatably arranged in the lifting cylinder and is used to transfer powder upward.

[0015] As an optional technical solution for an additive manufacturing circulating powder supply device, the lifting component includes a heating element, and the heating element can heat the lifting cylinder and / or the spiral blade to heat the powder.

[0016] As an optional technical solution of an additive manufacturing circulating powder supply device, the additive manufacturing circulating powder supply device also includes a filter screen and a powder slag box, the filter screen is arranged at the lower powder inlet of the lower powder piece, along the powder spreading direction, the powder slag box is arranged on the side of the forming platform, and the scraper in the forming platform scrapes the excess powder through the filter screen and finally scrapes it into the powder slag box; and / or,

[0017] A plurality of lifting inlets are arranged on the outer periphery of the lifting cylinder, and the lower end of the lifting cylinder is located in the lower powder piece.

[0018] As an optional technical solution of an additive manufacturing circulating powder supply device, the additive manufacturing circulating powder supply device further includes a vibrating member, the vibrating member is used to vibrate the filter screen, wherein the vibrating member is a vibration motor and is installed on a bracket of the filter screen; and / or,

[0019] The vibrating member includes a striking member, and the striking member is used for striking the filter screen.

[0020] As an optional technical solution for an additive manufacturing circulating powder supply device, the molding platform includes:

[0021] A platform body, wherein the platform body is concave downward from the top surface to form a forming cavity;

[0022] A bearing member, which is disposed inside the molding cavity and can reciprocate along the axis of the molding cavity, wherein the bearing surface of the bearing member is lower than the top surface of the platform body and is used to bear powder;

[0023] A bearing driving member, an output end of which is drivingly connected to the bearing member.

[0024] As an optional technical solution for an additive manufacturing circulating powder supply device, the powder loading member includes a powder loading box, and the powder loading outlet is in a long strip shape and is located at the bottom of the powder loading box; or,

[0025] The powder loading member is a cylindrical structure with a variable diameter, and its outlet is flat-mouthed, and the length of the outlet is consistent with the length of the powder rolling groove.

[0026] As an optional technical solution for an additive manufacturing circulating powder supply device, the powder spreading assembly includes a powder rolling trough and a powder rolling shaft. The opening of the powder rolling trough faces the powder loading outlet and is used to receive powder flowing out of the powder loading part. The powder rolling shaft is rotatably arranged in the powder rolling trough. The powder rolling shaft can evenly bring the powder out of the powder rolling trough during the rotation process and drop it on the forming platform in the form of a powder pile. The length direction of the powder pile is consistent with the length direction of the powder rolling shaft.

[0027] As an optional technical solution of an additive manufacturing circulating powder supply device, the powder lowering piece is located inside or outside the vacuum chamber; and / or,

[0028] The lifting assembly is located inside or outside the vacuum chamber.

[0029] A circulating powder supply method, applied to the additive manufacturing circulating powder supply device described in any of the above technical solutions, comprises the following method:

[0030] Add enough powder to the lower powder piece. During the vacuum process, the powder enters the lifting component, and the lifting component drives the powder to rise. The powder passes through the upper powder piece and enters the powder spreading component. The powder is then sent to the forming platform through the powder spreading component and spread. The excess powder falls into the lower powder piece and then enters the lifting cylinder of the lifting component for cyclic lifting.

[0031] The present invention has at least the following beneficial effects:

[0032] The present invention provides an additive manufacturing circulating powder supply device and a circulating powder supply method, the additive manufacturing circulating powder supply device comprises a vacuum chamber and a molding platform arranged in the vacuum chamber, the upper powder piece is used to provide powder for the molding platform, the powder spreading component is used to spread the powder on the molding platform, the lower powder piece is used to provide powder and collect the excess powder falling from the molding platform after the powder spreading is completed, and the lifting component is used to transfer the powder in the lower powder piece to the upper powder piece, so as to realize the reuse of the powder, so that the utilization rate of the powder is greatly improved and the cost is reduced; in addition, as the printing process is carried out synchronously, Whenever a powder spreading is completed, the lifting component will lift the excess powder again and transfer it to the powder loading part, so that the powder will be looser during the rising process, making it easier for the gas and moisture mixed in the powder to be quickly extracted during the vacuum process. When the recovered powder is used again, the gas and moisture content in the powder after the powder is spread is reduced, thereby reducing oxygen gain and ensuring the mechanical properties of the printed part. Finally, there is no need to screen the powder outside the vacuum chamber after the printing is completed and the furnace is opened, so as to avoid oxidation of the powder, ensure the quality of the powder, and then ensure the mechanical properties of the printed part. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] 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.

[0034] Figure 1 It is a structural schematic diagram of the circulating powder supply device for additive manufacturing in an embodiment of the present invention, and the lifting component is located in the vacuum chamber;

[0035] Figure 2 It is a schematic diagram of the structure of the circulating powder supply device for additive manufacturing in an embodiment of the present invention, and the powder supply part is in a tubular shape;

[0036] Figure 3 It is a structural schematic diagram of a circulating powder supply device for additive manufacturing in an embodiment of the present invention, wherein the lifting assembly is located outside the vacuum chamber;

[0037] Figure 4 This is a schematic diagram of the structure of the additive manufacturing circulating powder supply device in an embodiment of the present invention, where the spiral drive member is located at the top of the lifting cylinder;

[0038] Figure 5 It is a schematic structural diagram of the circulating powder supply device for additive manufacturing in an embodiment of the present invention, and the lower end of the lifting cylinder is located in the powder lowering part.

[0039] In the figure:

[0040] 100. Vacuum chamber;

[0041] 200, forming platform; 210, platform body; 211, forming cavity; 220, bearing member;

[0042] 300, powdering parts;

[0043] 400, powder spreading assembly; 410, powder rolling groove; 420, powder rolling shaft; 430, scraper;

[0044] 500, powder lower part; 501, bottom surface; 510, filter screen; 520, powder slag box; 530, support platform; 540, roller;

[0045] 600, lifting assembly; 610, lifting cylinder; 620, spiral blade; 630, spiral driving member; 640, heating member. DETAILED DESCRIPTION

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] In the present 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, and the like. 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).

[0051] 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.

[0052] 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.

[0053] Electron beam powder additive manufacturing is characterized by using electron beam to selectively melt metal powder particles (hereinafter referred to as powder) in a specific area on the molding platform, thereby realizing the manufacture of metal three-dimensional entities. The printing equipment in the prior art has the problem of low powder utilization efficiency and the inability to guarantee the mechanical properties of the printed parts. In order to improve the powder utilization rate, reduce costs, and ensure the mechanical properties of the printed parts, such as Figures 1 to 5As shown, this embodiment provides an additive manufacturing circulating powder supply device, which includes a vacuum chamber 100, a molding platform 200, an upper powder piece 300, a powder spreading assembly 400, a lower powder piece 500 and a lifting assembly 600. Among them, the upper powder piece 300 has an upper powder inlet and an upper powder outlet, and powder can enter the upper powder piece 300 from the upper powder inlet and flow out of the upper powder piece 300 from the upper powder outlet; the molding platform 200 is located in the vacuum chamber 100 and is used to carry powder; the upper powder piece 300 is located above the molding platform 200 and is used to transfer powder; the powder spreading component 400 is arranged below the upper powder outlet of the upper powder piece 300, and is used to spread the powder onto the molding platform 200; the lower powder piece 500 is arranged below the molding platform 200, and the lower powder piece 500 has a lower powder outlet for flowing out the powder, and has a lower powder inlet for collecting excess powder falling from the molding platform 200 after the powder spreading is completed; the lifting component 600 has a lifting inlet at the bottom and a lifting outlet at the top, the lifting inlet is connected to the lower powder outlet of the lower powder piece 500, and the lifting outlet is connected to the upper powder inlet of the upper powder piece 300, and the lifting component 600 is used to lift the powder entering from the lifting inlet and flow it out from the lifting outlet.

[0054] The above-mentioned arrangement realizes the reuse of excess powder during the material spreading process, which greatly improves the utilization rate of the powder and reduces the cost; in addition, as the printing process proceeds simultaneously, the initial powder is first lifted by the lifting component 600 and then enters the powder upper part 300, and each time the powder spreading is completed, the lifting component 600 will lift the excess powder again and transfer it to the powder upper part 300, so that the powder is looser during the rising process, so that the gas and moisture mixed in the powder are easier to be extracted during the vacuum process. When the recovered powder is used again, the gas and moisture content in the powder after the powder is spread is reduced, thereby reducing oxygen gain and ensuring the mechanical properties of the printed part; finally, there is no need to screen the powder outside the vacuum chamber 100 after the printing is completed and the furnace is opened to avoid oxidation, thereby ensuring the quality of the powder.

[0055] The gas and moisture mixed in the powder will be drawn away when the powder flows out of the upper powder part 300, that is, the gas and moisture mixed in the powder will be drawn away at the upper powder outlet of the upper powder part 300. In other embodiments, an air outlet may be provided on the lifting component 600 to allow the gas and moisture mixed in the powder to be drawn out. The air outlet needs to be provided at the top of the lifting component 600 and higher than the lifting outlet, that is, higher than the highest position of the lifting component 600 to lift the powder, so as to prevent the powder from flowing out of the air outlet.

[0056] In some embodiments, the lifting assembly 600 includes a lifting cylinder 610 and a spiral blade 620, the lifting inlet is arranged at the lower end of the lifting cylinder 610, the lifting outlet is arranged at the upper end of the lifting cylinder 610, and the spiral blade 620 is rotatably arranged in the lifting cylinder 610 and is used to transfer powder upward. Among them, the lifting inlet and the lower powder outlet are connected through a pipeline. The above arrangement allows the powder to be spread on the spiral blade 620 during the rising process, so that gas and moisture can be more easily extracted. In this embodiment, the axis of the lifting cylinder 610 extends in the vertical direction. In other embodiments, the powder can be transmitted by a transmission belt, and the transmission belt is arranged at an angle.

[0057] In some embodiments, reference Figure 5 As shown, several lifting inlets are arranged on the outer periphery of the lifting cylinder 610, and the lower end of the lifting cylinder 610 is located in the lower powder piece 500. This arrangement allows the powder in the lower powder piece 500 to enter the lifting cylinder 610 through the several lifting inlets, thereby improving the uniformity of feeding.

[0058] In order to improve the volatilization efficiency of moisture and gas in the powder, in some embodiments, the lifting cylinder 610 can be heated to heat the powder. In some embodiments, the spiral blade 620 can be heated to heat the powder. In some embodiments, the lifting cylinder 610 can be heated to heat the powder, and the spiral blade 620 can be heated to heat the powder. The above arrangement can embed the heating element 640 in the lifting cylinder 610 or in the spiral blade 620. In other embodiments, the heating element 640 can also be separated from the lifting cylinder 610 or the spiral blade 620 for easy maintenance. In one embodiment, the heating element 640 is attached to the outside of the lifting cylinder 610. In another embodiment, refer to Figure 1 As shown, the heating element 640 is disposed outside the lifting cylinder 610 and is spaced apart from the lifting cylinder 610. In another embodiment, the heating element 640 is disposed on the lower side of the spiral blade 620 to avoid interference with the powder.

[0059] The lifting assembly 600 further includes a spiral drive member 630, which is in transmission connection with the spiral blade 620 to drive the spiral blade 620 to rotate. Figure 1 As shown, the screw drive member 630 is disposed at the top of the lifting cylinder 610. In another embodiment, referring to Figure 2 As shown, the screw drive member 630 is disposed at the bottom of the lifting cylinder 610 .

[0060] The recycled powder may aggregate and form blocks, which will affect the printing accuracy when used again. To solve this problem, in some embodiments, the additive manufacturing circulating powder supply device also includes a filter 510 and a powder slag box 520. The filter 510 is arranged at the lower powder inlet of the lower powder part 500. Along the powder spreading direction (i.e., the moving direction of the scraper 430), the powder slag box 520 is arranged on the side of the molding platform 200. The scraper 430 in the molding platform 200 scrapes the excess powder through the filter 510 and finally scrapes it into the powder slag box 520. The above setting screens the powder, and the powder with qualified particle size (smaller than the preset size) falls into the lower powder part 500 and participates in subsequent use. The powder with unqualified particle size (larger than the preset size) is scraped into the powder slag box 520. Among them, the power part provides power for the movement of the scraper 430. The control unit controls the speed, direction and movement logic sequence of each moving part.

[0061] To ensure smooth screening, in some embodiments, the additive manufacturing circulating powder supply device further includes a vibrating member, which is used to vibrate the filter screen 510, wherein the vibrating member is a vibration motor and is installed on the bracket of the filter screen 510. Alternatively, the vibrating member includes a knocking member, which is used to knock the filter screen 510.

[0062] Specifically, the vibrating member further includes a rotating motor or a rotating cylinder, and the striking member is a flexible rod-shaped member installed at the output end of the rotating motor, which continuously strikes the support of the filter 510 during the rotation process and can pass over the support after deforming itself. In other embodiments, the vibrating member is a telescopic cylinder, and its output end can reciprocate to strike the support around the filter 510.

[0063] To ensure that the powder can be spread evenly, in some embodiments, the powder spreading component 400 includes a powder rolling groove 410 and a powder rolling shaft 420. The powder rolling groove 410 is located below the upper powder part 300. The opening of the powder rolling groove 410 faces the upper powder outlet and is used to receive the powder flowing out of the upper powder part 300. The powder rolling shaft 420 is rotatably arranged in the powder rolling groove 410. The powder rolling shaft 420 can evenly bring the powder out of the powder rolling groove 410 during the rotation process and drop it on the forming platform 200 in the form of a powder pile. The scraper 430 spreads the powder pile on the forming platform 200 during the movement process. The length direction of the long strip of powder pile is consistent with the length direction of the powder rolling shaft 420.

[0064] Regarding the structure of the powder loading member 300, in some embodiments, refer to Figure 1 As shown, the powder loading part 300 includes a powder loading box, and the powder loading outlet is in a long strip shape and is located at the bottom of the powder loading box. Figure 2 As shown, the powder upper member 300 is a variable diameter cylindrical structure, whose inlet is cylindrical and whose outlet is flat, and the outlet length is greater than the width of the supporting member 220 to ensure that the powder can evenly enter the powder rolling groove 410 along the length direction of the powder rolling shaft 420.

[0065] The molding platform 200 includes a platform body 210, a carrier 220 and a carrier drive, wherein the platform body 210 is provided with a molding cavity 211 which is concave downward from the top surface; the carrier 220 is arranged inside the molding cavity 211 and can reciprocate along the axis of the molding cavity 211, the bearing surface of the carrier 220 is lower than the top surface of the platform body 210, and is used to carry powder, and the carrier 220 can also carry the part of the printed piece that has been printed; the output end of the carrier drive is connected to the carrier 220 in a transmission manner. The above arrangement enables the scraper 430 to spread the powder pile on the carrier 220 during the movement process, and during the printing process, the carrier 220 continuously descends, so that the part of the printed piece that has been printed is hidden in the molding cavity 211.

[0066] The supporting member 220 includes a piston plate and a support shaft. The piston plate is slidably disposed in the forming cavity 211 and is used to carry powder and printed parts. The supporting driving member can be a servo motor or a cylinder. The screw rod is rotatably disposed on the platform body 210 and is connected to the output end of the supporting driving member. The nut is threadedly matched with the screw rod and is connected to the support shaft.

[0067] The lower powder piece 500 is a box structure, and the additive manufacturing circulating powder supply device also includes a support table 530. The lower powder piece 500 slides or is rolled on the support table 530 by rollers 540 to facilitate the movement of the lower powder piece 500 after printing is completed.

[0068] To ensure that the powder in the lower powder member 500 smoothly enters the lifting inlet of the lifting assembly 600, the lower bottom surface 501 of the lower powder member 500 is an inclined surface and is inclined toward the lower powder outlet.

[0069] The volume of the upper powder box in the existing printing equipment is relatively large, so as to provide sufficient powder for printing, which leads to high cost. In addition, the upper powder box is installed above the molding platform 200, which is heavy and difficult to install. In this application, a circular feeding method is adopted to reduce the overall material consumption, and the volume of the lower powder piece 500 can be appropriately reduced to reduce the cost. At the same time, by using the lower powder piece 500 as the feeding piece, the volume of the upper powder piece 300 located above the molding platform 200 can be reduced as much as possible, reducing the difficulty of installation.

[0070] The upper powder piece 300 is disposed inside the vacuum chamber 100 in order to simplify the structure of the vacuum chamber 100 and avoid setting a sealing structure between the two. In some embodiments, in order to reduce the volume of the vacuum chamber 100, the upper powder piece 300 can be disposed outside the vacuum chamber 100, and the loading outlet is connected to the vacuum chamber 100. Similarly, the lower powder piece 500 is located inside or outside the vacuum chamber 100. The lifting assembly 600 is located inside or outside the vacuum chamber 100. The lifting assembly 600 and the heating element 640 are installed inside the vacuum chamber 100, and powder circulation can be realized during the printing process to ensure that the temperature of the powder is not significantly reduced. Refer to Figure 3 As shown, the lifting assembly 600, the heating element 640 and the powder lowering element 500 are installed outside the vacuum chamber 100, which can effectively reduce the volume of the vacuum chamber 100 and reduce costs while ensuring that the powder temperature does not drop significantly. In either case, it is necessary to ensure that the powder circulates in a vacuum environment during printing.

[0071] In some embodiments, the additive manufacturing circulating powder supply device includes two sets of feeding mechanisms, and the upper powder piece 300, the powder spreading assembly 400, the lower powder piece 500 and the lifting assembly 600 constitute the feeding mechanism. The two sets of feeding mechanisms are arranged on both sides of the forming platform 200 to improve the powder spreading efficiency.

[0072] This embodiment also provides a printing method, including the following steps: in the pre-printing preparation stage, a sufficient amount of powder is added to the lower powder piece 500, and during the vacuuming process, after the powder enters the lifting component 600, the lifting component 600 drives the powder to rise, and the powder is dispersed during the rising process, which accelerates the volatilization of gas and water in the powder. The powder passes through the upper powder piece 300 and enters the powder spreading component 400, and then the powder is sent to the molding platform 200 through the powder spreading component 400, and the powder is spread. The excess powder falls into the lower powder piece 500, and then enters the lifting cylinder 610 of the lifting component 600 for cyclic lifting. The above method allows the powder to be reused and reduces costs; in addition, the water and gas inside the powder are efficiently discharged during the rising process of the powder, which is conducive to ensuring the mechanical properties of the printed part.

[0073] The lifting assembly 600 drives the powder to rise, and the powder is heated, which further accelerates the volatilization of gas and water in the powder. The powder passes through the upper powder component 300 and enters the powder rolling groove 410, and then is sent to the forming platform 200 through the powder rolling shaft 420, and the scraper 430 spreads the powder. After passing through the filter 510, the excess powder falls into the lower powder component 500, and then enters the lifting cylinder 610 of the lifting assembly 600 for cyclic lifting; the scraper 430 continues to move, and the powder with larger particle size is scraped into the powder slag box 520 by the same scraper 430, and the stroke of the scraper 430 is easy to plan.

[0074] 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. An additive manufacturing circulating powder supply device, characterized in that: include: A vacuum chamber (100); A forming platform (200), located in the vacuum chamber (100) and used for carrying powder; A powder loading part (300), located above the molding platform (200), is used for transferring powder materials; A powder spreading component (400), disposed below the powder supply outlet of the powder supply member (300), and used for spreading powder material onto the molding platform (200); A powder discharge member (500) is disposed below the molding platform (200), and has a powder discharge inlet for collecting excess powder material falling from the molding platform (200) after the powder is spread, and has a powder discharge outlet for discharging the powder material; The lifting assembly (600) has a lifting inlet at the bottom and a lifting outlet at the top, wherein the lifting inlet is connected to the lower powder outlet of the lower powder piece (500), and the lifting outlet is connected to the upper powder inlet of the upper powder piece (300). The lifting assembly (600) is used to lift the powder entering from the lifting inlet and let it flow out from the lifting outlet.

2. The additive manufacturing circulating powder supply device according to claim 1, characterized in that: The lifting assembly (600) comprises a lifting cylinder (610) and a spiral blade (620), wherein the lifting inlet is arranged at the lower end of the lifting cylinder (610), and the lifting outlet is arranged at the upper end of the lifting cylinder (610), and the spiral blade (620) is rotatably arranged in the lifting cylinder (610) and is used to transfer powder upward.

3. The additive manufacturing circulating powder supply device according to claim 2, characterized in that: The lifting assembly (600) includes a heating element (640), and the heating element (640) can heat the lifting cylinder (610) and / or the spiral blade (620) to heat the powder.

4. The additive manufacturing circulating powder supply device according to claim 2, characterized in that: The additive manufacturing circulating powder supply device further comprises a filter screen (510) and a powder slag box (520), wherein the filter screen (510) is arranged at the powder lower inlet of the powder lowering part (500), and the powder slag box (520) is arranged beside the molding platform (200) along the powder spreading direction, and the scraper (430) in the molding platform (200) scrapes excess powder through the filter screen (510) and finally scrapes it into the powder slag box (520); and / or, A plurality of lifting inlets are arranged on the outer periphery of the lifting cylinder (610), and the lower end of the lifting cylinder (610) is located in the lower powder member (500).

5. The additive manufacturing circulating powder supply device according to claim 4, characterized in that: The additive manufacturing circulating powder supply device further comprises a vibrating member, the vibrating member being used to vibrate the filter screen (510), wherein the vibrating member is a vibration motor and is mounted on a bracket of the filter screen (510); and / or, The vibrating member comprises a knocking member, and the knocking member is used to knock the filter screen (510).

6. The additive manufacturing circulating powder supply device according to claim 1, characterized in that: The molding platform (200) comprises: A platform body (210), wherein the platform body (210) is provided with a molding cavity (211) recessed downward from the top surface; A bearing member (220), the bearing member (220) is disposed inside the molding cavity (211) and can reciprocate along the axis of the molding cavity (211), the bearing surface of the bearing member (220) is lower than the top surface of the platform body (210), and is used to bear powder; A bearing drive member, the output end of which is in driving connection with the bearing member (220).

7. The additive manufacturing circulating powder supply device according to claim 6, characterized in that: The powder loading member (300) comprises a powder loading box, and the powder loading outlet is in the shape of an elongated strip and is located at the bottom of the powder loading box; or, The powder loading member (300) is a cylindrical structure with a variable diameter, and its outlet is flat-mouthed, and the length of the outlet is greater than the width of the supporting member (220).

8. The additive manufacturing circulating powder supply device according to claim 1, characterized in that: The powder spreading assembly (400) comprises a powder rolling groove (410) and a powder rolling shaft (420). The opening of the powder rolling groove (410) faces the powder loading outlet and is used to receive powder flowing out of the powder loading member (300). The powder rolling shaft (420) is rotatably disposed in the powder rolling groove (410). During the rotation process, the powder rolling shaft (420) can evenly bring the powder out of the powder rolling groove (410) and drop it on the forming platform (200) in the form of a powder pile. The length direction of the powder pile is consistent with the length direction of the powder rolling shaft (420).

9. The additive manufacturing circulating powder supply device according to any one of claims 1 to 8, characterized in that: The lower powder piece (500) is located inside or outside the vacuum chamber (100); and / or, The lifting assembly (600) is located inside or outside the vacuum chamber (100).

10. A circulating powder supply method, applied to the additive manufacturing circulating powder supply device according to any one of claims 1 to 9, characterized in that: The following methods are included: A sufficient amount of powder is added to the lower powder piece (500). During the vacuuming process, the powder enters the lifting component (600), and the lifting component (600) drives the powder to move upward. The powder passes through the upper powder piece (300) and enters the powder spreading component (400). The powder is then sent to the molding platform (200) through the powder spreading component (400) and spread. Excess powder falls into the lower powder piece (500) and then enters the lifting cylinder (610) of the lifting component (600) for cyclic lifting.

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