Powder feeding and spreading mechanism and powder feeding and spreading method

Abstract

A powder feeding and spreading mechanism (100) and method. The mechanism (100) comprises a feeding cavity (1) having a discharge port (11) at an upper portion, a powder transfer tool (2) configured to be able to reciprocate between an original position located in the feeding cavity (1) and a powder spreading position located at the discharge port (11), and a powder spreading assembly (3), wherein the powder spreading assembly (3) is located above the discharge port (11) and can move transversely; the powder spreading assembly (3) comprises a support, a powder spreading tool mounted on the support, and at least one powder scraping tool (33) arranged on the support; the at least one powder scraping tool (33) is configured to be able to remove excess powder above a second horizontal plane from the powder transfer tool (2) located at the powder spreading position during transverse movement, the second horizontal plane being above a first horizontal plane; and a powder spreading roller (32) is configured to be able to transfer the powder from the powder transfer tool located at the powder spreading position and spread the powder onto a printing platform (200) during the transverse movement.

Description

Powder supply and laying mechanism and powder supply and laying method Technical Field

[0001] The present application relates to the technical field of additive manufacturing equipment, and in particular to a powder supply and laying mechanism and a powder supply and laying method for supplying and laying powder onto a printing platform of an additive manufacturing equipment. Background Art

[0002] In powder 3D printing, the target part is produced in layers of powder that are stacked one after another. The success of the print and the quality of the part depend largely on the uniformity of the powder layer. To improve printing efficiency, a bidirectional powder layering structure is often used.

[0003] Patent document CN107530970A discloses a construction material supply method, which includes using a rotatable blade to move a portion of the construction material from the supply module to the top of the supply module; and spreading the moved portion of the construction material across the support platform. In this solution, the amount of powder provided to the powder roller varies with each layer of powder applied. Furthermore, the powder can easily overflow from the roller during application, or excessive powder application in the first half of the application can result in uneven and wavy powder application, which can affect the quality of 3D printed products. Summary of the Invention

[0004] The purpose of the present application is to provide a powder supply and laying mechanism and a powder supply and laying method, in the hope of improving the consistency of the powder layer laid on the printing platform.

[0005] In a first aspect of the present application, a powder supply and laying mechanism is provided for supplying and laying powder onto a printing platform of an additive manufacturing device, the powder supply and laying mechanism comprising:

[0006] a supply chamber for holding powder and having an outlet at an upper portion, wherein the outlet is located on a first horizontal plane and is capable of docking with the printing platform;

[0007] a powder transporting tool configured to be reciprocally movable between an original position in the supply chamber and a powder spreading position at the discharge port; and

[0008] A powder spreading assembly is located above the discharge port and is capable of moving laterally, the powder spreading assembly comprising a bracket, a powder spreading tool mounted on the bracket, and at least one powder scraping tool, the at least one powder scraping tool being configured to remove excess powder above a second horizontal plane from the powder transport tool located at the powder spreading position when moving laterally, the second horizontal plane being above the first horizontal plane, and the powder spreading roller being configured to transfer powder from the powder transport tool located at the powder spreading position and spread it onto the printing platform when moving laterally.

[0009] According to the above scheme, by setting up a powder scraping tool, it can remove excess powder on the powder transport tool before the powder spreading tool spreads the powder, so that the powder transport tool can retain a certain amount of powder each time, so that the powder laid each time is consistent; therefore, this case can simply achieve control of the amount of powder used for laying on the printing platform each time by designing the high and low position of the powder scraping tool.

[0010] In combination with the first aspect, in certain embodiments of the first aspect, the powder spreading tool includes a powder spreading roller, and the powder spreading roller is rotatable around its own axis and is arranged on the bracket.

[0011] In combination with the first aspect, in certain embodiments of the first aspect, the number of the powder scraping tools is a pair, and the pair of powder scraping tools are both supported on the bracket and are located on both sides of the powder spreading roller in the transverse direction.

[0012] In combination with the first aspect, in certain embodiments of the first aspect, the axis of the powder spreading roller is located above the second horizontal plane.

[0013] In combination with the first aspect, in certain embodiments of the first aspect, the scraping tool has a bottom end portion, which extends longitudinally and is located on the second horizontal plane.

[0014] In combination with the first aspect, in certain embodiments of the first aspect, the powder transport tool includes a rotating blade rotatably arranged in the supply chamber, the rotating blade has a supporting surface capable of supporting the powder, and the supporting surface extends longitudinally; when the powder transport tool is in the powder spreading position, the supporting surface is located on the first horizontal plane.

[0015] In combination with the first aspect, in certain embodiments of the first aspect, the discharge port has a first edge portion and a second edge portion relative to each other, and the first edge portion is configured to be able to dock with the printing platform; when the powder transport tool is in the original position, the rotating blade is close to the second edge portion.

[0016] The second aspect of the present application is a powder supply and laying method for transferring powder located in a supply chamber from a discharge port at an upper portion of the supply chamber and laying the powder onto a printing platform of an additive manufacturing device, the method comprising: utilizing a powder transport tool capable of reciprocating between the interior of the supply chamber and the discharge port to transfer the powder from the loading chamber to the discharge port and maintaining the powder transport tool at the discharge port; utilizing a powder scraping tool capable of moving laterally above the discharge port to remove excess powder exceeding a set height from the powder transport tool; and utilizing a laying tool capable of moving laterally above the discharge port to transfer at least part of the powder on the powder transport tool and lay the powder onto the printing platform.

[0017] In combination with the second aspect, in certain embodiments of the second aspect, in the method, the removed excess powder is returned to the supply chamber or transferred to a collection chamber.

[0018] In combination with the second aspect, in certain embodiments of the second aspect, in the method, the lateral movement direction of the scraping tool when removing excess powder is opposite to the lateral movement direction of the laying tool when transferring at least part of the powder and laying it onto the printing platform.

[0019] Other advantages of the present invention will be described in detail in the following specific embodiments in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] FIG1 is a schematic structural diagram of a powder supply and laying mechanism provided in one embodiment of the present application;

[0021] FIG2 is a schematic diagram of a supply chamber provided in one embodiment of the present application;

[0022] FIG3 is a schematic diagram of a rotating blade in a powder spreading position according to an embodiment of the present application;

[0023] FIG4 is a schematic diagram of a rotating blade in an original position provided by an embodiment of the present application;

[0024] FIG5 is a schematic structural diagram of a powder supply and laying mechanism provided in another embodiment of the present application;

[0025] FIG6 is a first schematic diagram of the relative relationship between the powder spreading assembly and the rotating blades of the present application during operation;

[0026] FIG7 is a second schematic diagram of the relative relationship between the powder spreading assembly and the rotating blades of the present application during operation;

[0027] FIG8 is a schematic diagram of the powder supply and laying mechanism of the present application in a first state during operation, wherein the powder laying assembly is in a rest position and the rotating blades are in an original position;

[0028] FIG9 is a schematic diagram of the powder supply and laying mechanism of the present application in a second working state, wherein the powder laying assembly is in a rest position and the rotating blade is in a powder laying position;

[0029] FIG10 is a schematic diagram of the powder supply and laying mechanism of the present application in a third working state, wherein part of the powder laying assembly moves to the right side of the supply chamber;

[0030] FIG11 is a schematic diagram of the powder supply and laying mechanism of the present application in a fourth working state; wherein the powder laying assembly moves to the left side of the supply chamber;

[0031] FIG12 is a flow chart of a powder supply and laying method provided in one embodiment of the present application.

[0032] Among them: 100, powder supply and laying mechanism; 200, printing platform; 300, powder supply chamber; 1, supply cavity; 2, powder transfer tool; 3, powder laying component; 400, conveying channel; 11, discharge port; 111, first edge portion 1; 112, second edge portion; 113, arc-shaped inner wall surface; 21, rotating blade; 211, supporting surface; 31, bracket; 32, powder laying roller; 33, powder scraping tool; 331, bottom end portion. DETAILED DESCRIPTION

[0033] The technical solution of this application will be clearly described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making any creative work are within the scope of protection of this application.

[0034] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application.

[0035] It should be noted that the directional terms such as "upper", "lower", "left", "right", "horizontal", and "longitudinal" described in the embodiments of the present application are described based on the angles shown in the accompanying drawings and should not be understood as limiting the embodiments of the present application. In addition, in the context, it should be understood that when it is mentioned that one element is connected to another element, it can not only be directly connected to the other element, but also be indirectly connected to the other element through an intermediate element.

[0036] The powder supply and laying mechanism and powder laying control method proposed in the embodiments of the present application can be applied to additive manufacturing equipment, and the powder used in additive manufacturing may include at least one of polymer, metal powder or ceramic powder.

[0037] Referring to Figure 1, a powder supply and placement mechanism 100 is shown. This mechanism 100 is used to place powder onto a printing platform 200 of an additive manufacturing device. Specifically, it transfers powder from a powder supply chamber 300 and places it onto the printing platform. The powder supply and placement mechanism 100 primarily comprises a supply chamber 1, a powder transfer tool 2, and a powder placement assembly 3.

[0038] The supply chamber 1 is connected to the powder supply chamber 300 via a conveying channel 400. The supply chamber 1 is used to hold powder and has an upper discharge port 11 located on a first horizontal plane X1 and capable of docking with the printing platform 200. Referring to Figure 2 , the discharge port 11 has opposing first and second edge portions 111, 112, and an arcuate inner wall surface 113 connecting the first and second edge portions 111, 112. Both the first and second edge portions 111, 112 extend longitudinally. The first edge portion 111 is capable of docking with the printing platform 200.

[0039] The powder transport tool 2 is configured to be reciprocatingly movable between an original position in the supply chamber 1 and a powder spreading position at the discharge port 11. Continuing with FIG1 , the powder transport tool 2 in this example includes a rotating blade 21 rotatably disposed in the supply chamber 11, the rotating blade 21 having a supporting surface 211 capable of supporting the powder, and the supporting surface 211 extends longitudinally.

[0040] As shown in FIG3 , the powder transport tool 2 is in the powder spreading position, with the rotating blades 21 close to the first edge 111 and the support surface 211 located on the first horizontal plane X1. As shown in FIG4 , the powder transport tool 2 is in the home position, with the rotating blades 21 close to the second edge 112. By rotating the powder transport tool 2 between the home position and the powder spreading position, the powder in the supply chamber 1 can be continuously transported to the discharge port 11.

[0041] Continuing to refer to Figure 1, the powder spreading assembly 3 is located above the discharge port 11 and can move laterally (i.e., in the left and right directions) between multiple positions. The powder spreading assembly 3 includes a bracket 31, a powder spreading roller 32 mounted on the bracket, and a powder scraping tool 33 provided on the bracket 31. The powder spreading roller 32 can be rotated around its own axis L0 and is provided on the bracket 31. In the direction from the printing platform 200 to the supply chamber 1, the powder scraping tool 33 is provided behind the powder spreading roller 32. When the powder spreading assembly 3 moves from the printing platform 200 toward the supply chamber 1, the powder spreading roller 32 will reach the top of the supply chamber 1 before the powder scraping tool 33; the lateral spacing between the powder scraping tool 33 and the powder spreading roller 32 is greater than or equal to the width of the support surface 211 of the rotating blade 21. In other embodiments, the powder spreading roller can be replaced by other types of powder spreading tools.

[0042] The powder scraping tool 33 has a bottom end 331 that extends longitudinally and is located on a second horizontal plane X2. The second horizontal plane X2 is above the first horizontal plane X1. The axis L0 of the powder spreading roller 32 is located above the second horizontal plane X2.

[0043] The powder scraping tool 33 is configured to remove excess powder above the second horizontal plane X2 from the support surface 211 of the powder transport tool in the powder spreading position when it moves laterally with the support 31. The powder spreading roller 32 is configured to spread powder from the support surface 211 of the powder transport tool in the powder spreading position onto the printing platform 200 when it moves laterally.

[0044] In some embodiments, a pair of powder scraping tools is provided, suitable for situations where a supply chamber is provided on each side of the printing platform. As shown in Figure 5, in this mechanism, a pair of supply chambers 1 are symmetrically provided on both sides of the printing platform 200, and a powder transporting tool 2 is provided in each supply chamber 1. A pair of powder scraping tools 33 are supported on the bracket 31 and are respectively located on the left and right sides of the powder spreading roller 32. The pair of powder scraping tools 33 will also follow the bracket 31 and the powder spreading roller 32 to move laterally between the two supply chambers 1. When the pair of powder scraping tools 33 are in operation, the powder scraping tool 33 located on the left side of the powder spreading roller 32 will play a role in scraping off excess powder during the process of transporting powder in the supply chamber 1 on the right, while the powder scraping tool 33 located on the right side of the powder spreading roller 32 will play a role in scraping off excess powder during the process of transporting powder in the supply chamber 1 on the left.

[0045] In this embodiment, the rotating blade 21 only stops at one position during powder delivery: the powder spreading position. As shown in Figure 6, during powder application, the rotating blade 21 rotates from its starting position to the powder spreading position, with powder P supported on the rotating blade 21. As shown in Figure 7, the movement of the support 31 is controlled to remove excess powder P2 into the supply chamber 1 using a powder scraper 33 on the support 31. Finally, the powder spreading roller 32 moves in the opposite direction, transferring powder P1 from the rotating blade 21 to the printing platform 200 for powder spreading. In other embodiments, excess powder can also be removed to a collection chamber.

[0046] In this case, the distance between the first horizontal plane X1 and the second horizontal plane X2 limits the amount of powder that can be spread on the printing platform 200 by the powder spreading roller 32. Since the positions of the first horizontal plane X1 and the second horizontal plane X2 are relatively fixed, the amount of powder supplied by the rotating blade 21 is basically constant, so that the thickness of each layer of powder remains basically consistent when spreading the powder.

[0047] When a powder spreading action begins, the powder spreading assembly 3 stays above the supply chamber 1. At this time, the powder scraping tool 33 on the left side of the bracket 31 is to the left of the supply chamber 1 and the left end face of the rotating blade 21, so that when the bracket 31 moves to the right, the powder on the rotating blade 21 can be removed back to the supply chamber 1. The center position of the powder spreading roller 32 is to the right of the powder pile on the rotating blade 21, ensuring that the powder pile will not hit the powder spreading roller 32 when the rotating blade 21 is in the powder spreading position.

[0048] In this case, the powder supply and laying mechanism can be a symmetrical structure with two parts in both directions to improve printing efficiency. The following only describes the powder supply process on one side:

[0049] As shown in FIG8 , before the powder spreading action begins, the powder spreading assembly 3 is in the stop position, and the rotating blade 21 rotates to the original position, and the powder is transported from the powder supply chamber 300 to the supply cavity 1 through the transport channel 400 .

[0050] As shown in FIG9 , when applying powder, the rotating blade 21 rotates clockwise to the powder spreading position, thereby bringing the powder P in the supply chamber 1 to the powder spreading position. At this time, the powder pile is located between the powder scraping tool 33 and the powder spreading roller 32.

[0051] As shown in Figure 10, after the rotating blade 21 delivers the powder to the powder spreading position, the powder spreading assembly 3 moves to the right. During the movement, the powder spreading assembly 3 uses the powder scraping tool 33 on the bracket 31 to push the excess powder P2 back to the supply chamber 1.

[0052] As shown in FIG11 , after removing excess powder P2 , the powder spreading assembly 3 moves to the left, and the powder spreading roller 32 performs the powder spreading operation, spreading the powder P1 onto the printing platform 200 .

[0053] After the powder is laid, the powder laying assembly 3 stops at the stop position of the other side supply chamber 1. At the same time, the printing platform 200 moves downward by the thickness of the powder layer to prepare for the next powder laying action.

[0054] As shown in FIG12 , this case also provides a powder supply and laying method for transferring powder in a supply chamber from an outlet at the upper portion of the supply chamber and laying the powder onto a printing platform of an additive manufacturing device. The method includes:

[0055] S1, transfer powder, that is, transfer powder from the supply chamber to the discharge port, specifically: control the powder spreading component to be located at the stop position of the supply chamber, use the powder transport tool that can move back and forth between the inside of the supply chamber and the discharge port to transport the powder from the supply chamber to the discharge port and keep the powder transport tool at the discharge port. At this time, the powder pile transported to the discharge port by the powder transport tool is in the middle position between the powder scraping tool and the powder spreading roller.

[0056] In step S1 , the powder transporting tool is not limited to the aforementioned rotary blade type.

[0057] S2, removing excess powder, that is, scraping off the powder that exceeds the set height, specifically: using a powder scraping tool that can move laterally above the discharge port to remove the excess powder that exceeds the set height from the powder transport tool.

[0058] In step S2, by controlling the powder spreading component to move in a direction away from the printing platform so that the powder scraping tool passes through the powder pile on the powder transport tool, the powder scraping tool can remove excess powder on the powder transport tool that exceeds a set height (such as exceeding the height of the second horizontal plane). This part of the powder can be sent back to the supply chamber or stored in a collection chamber. The powder scraping tool is set on the bracket mentioned above, or it can be an independently movable component. When the powder scraping tool is set as an independently movable component, in this step, only the powder scraping tool can be controlled to move in a direction away from the printing platform without controlling the overall movement of the powder spreading component. After executing step S2, a set dose of powder can be retained on the powder transport tool for powder spreading purposes.

[0059] S3, laying powder, specifically: using a laying tool that can move laterally above the discharge port to transfer at least part of the powder on the powder transport tool and lay it on the printing platform.

[0060] In step S3, the lateral movement direction of the laying tool is opposite to the lateral movement direction in step S2, so that the powder laying roller pushes the powder retained on the powder transport tool toward the printing platform, so that the set dose of powder will be evenly laid on the printing platform.

[0061] By executing the above method, the powder laid on the printing platform can be kept substantially consistent each time, thereby improving the consistency of the powder layer laid on the printing platform.

Claims

1. A powder supply and spreading mechanism for supplying and spreading powder to a printing platform of an additive manufacturing device, the powder supply and spreading mechanism comprising: A supply chamber for holding powder and having a discharge port at an upper portion, the discharge port being located on a first horizontal plane and capable of docking with the printing platform; A powder transfer tool configured to reciprocate between an original position within the supply chamber and a powder spreading position at the discharge port; And A powder spreading assembly located above the discharge port and capable of lateral movement, the powder spreading assembly including a bracket, a powder spreading tool mounted on the bracket, and at least one powder scraping tool, the at least one powder scraping tool being configured to remove excess powder above a second horizontal plane from the powder transfer tool at the powder spreading position when moving laterally, the second horizontal plane being above the first horizontal plane, the powder spreading roller being configured to transfer and spread powder from the powder transfer tool at the powder spreading position to the printing platform when moving laterally.

2. The powder supply and laying mechanism according to claim 1, wherein The powder spreading tool includes a powder spreading roller, and the powder spreading roller is rotatably provided on the bracket about its own axis.

3. The powder supply and laying mechanism according to claim 2, characterized in that, The number of the powder scraping tools is a pair, and the pair of powder scraping tools are both supported on the bracket and are respectively located on both sides of the powder spreading roller in the lateral direction.

4. The powder supply and laying mechanism according to claim 1, characterized in that The axis of the powder spreading roller is located above the second horizontal plane.

5. The powder supply and laying mechanism according to claim 1, characterized in that, The powder scraping tool has a bottom end portion, and the bottom end portion extends longitudinally and is located on the second horizontal plane.

6. The powder supply and laying mechanism according to claim 1, characterized in that, The powder transfer tool includes a rotating blade rotatably provided in the supply chamber, the rotating blade having a support surface capable of supporting the powder, and the support surface extending longitudinally; When the powder transfer tool is in the powder spreading position, the support surface is located on the first horizontal plane.

7. The powder supply and laying mechanism according to claim 6, characterized in that, The discharge port has opposite first and second edge portions, and the first edge portion is configured to be capable of docking with the printing platform; When the powder transfer tool is in the original position, the rotating blade is close to the second edge portion.

8. A powder supply and laying method for transferring powder located in a supply cavity from a discharge port at the upper part of the supply cavity and laying it at a printing platform of an additive manufacturing device, characterized in that, The method includes: Using a powder transfer tool capable of reciprocating between the interior of the supply chamber and the discharge port to transport powder from the supply chamber to the discharge port and keeping the powder transfer tool at the discharge port; Using a powder scraping tool capable of lateral movement above the discharge port to remove excess powder exceeding a set height from the powder transfer tool; and Using a spreading tool capable of lateral movement above the discharge port to transfer and spread at least part of the powder on the powder transfer tool to the printing platform.

9. The method according to claim 8, characterized in that, In the method, the removed excess powder is returned to the supply chamber or transferred to a collection chamber.

10. The method according to claim 8, wherein In the method, the lateral movement direction of the powder scraping tool when removing the excess powder is opposite to the lateral movement direction of the spreading tool when transferring and spreading at least part of the powder to the printing platform.

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