A cantilever single-blade bidirectional powder spreading mechanism for selective laser melting forming

Abstract

The present application relates to a kind of cantilever single doctor blade bidirectional powder spreading mechanism for laser selective melting forming, including doctor blade holder assembly and limit block assembly, doctor blade holder assembly is located in the forming chamber above forming platform, limit block assembly is located in the side of forming platform;Doctor blade holder assembly includes doctor blade holder body, powder distributor, powder holding plate, doctor blade, doctor blade pressing plate, one-way powder spreading and powder falling position and bidirectional powder spreading and powder falling position are provided on doctor blade holder body, powder distributor is installed on doctor blade holder body, one-way powder falling channel is provided in doctor blade holder body, one-way powder falling channel is respectively communicated with one-way powder spreading and powder falling position and one of the powder distribution cavity of powder distributor, another powder distribution cavity of powder distributor is cooperated with doctor blade holder body to form another powder falling channel.The present application can easily switch one-way powder spreading and bidirectional powder spreading state without changing mechanism and opening hatch by adjusting powder receiving position, avoid stopping in the middle of printing, save operation time, improve printing efficiency.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of additive manufacturing technology, and particularly relates to a cantilever single-blade bidirectional powder spreading mechanism for laser selective melting forming. BACKGROUND

[0002] Additive manufacturing (also known as laser selective melting or metal 3D printing) technology is a new processing method that has appeared in recent years. The raw material used in this technology is powder with a size of tens to hundreds of microns. In the forming process, the powder is uniformly spread on the forming platform by a powder supply device and a powder spreading device, and then the powder in a specific geometric area on the surface is melted by using a laser energy source to produce metallurgical bonding, so that the part grows layer by layer to realize three-dimensional forming.

[0003] In the laser selective melting process, due to the growth angle of the part, one-way powder spreading printing is required in individual cases. In addition to such special cases, bidirectional powder spreading printing can greatly save printing time. The traditional double-blade bidirectional powder spreading mechanism has the problems of difficulty in mutual leveling of the two blades, the need to disassemble one side of the blade when switching to one-way powder spreading, the need to open the cabin door for mechanism change when disassembling the blade, inconvenience in operation, and the existence of splashing particles in the backstroke powder during bidirectional powder spreading, which affects the printing effect. SUMMARY

[0004] In order to solve the problems existing in the prior art, the present application provides a cantilever single-blade bidirectional powder spreading mechanism for laser selective melting forming. This mechanism perfectly solves the above-mentioned problems for the single-blade bidirectional powder spreading mechanism. The single-blade leveling is simple and only needs to be leveled once. The powder receiving position can be adjusted at any time during the printing process according to the part angle, the switching between one-way and bidirectional powder spreading is realized, the mechanism does not need to be changed, and the cabin door does not need to be opened, which avoids stopping during printing, saves operation time, improves printing efficiency, and avoids the problem of powder contamination caused by the backstroke powder being blocked by the powder catching plate without passing through the powder bed.

[0005] The present application is implemented as follows. A cantilever single-blade bidirectional powder spreading mechanism for laser selective melting forming includes a scraper frame assembly and a limiting block assembly. The scraper frame assembly is located above the forming platform in the forming chamber, and the limiting block assembly is located on one side of the forming platform. The limiting block assembly is different from the powder falling mechanism on different sides.

[0006] The scraper frame assembly comprises a scraper frame body, a powder distributor, a powder catching plate, a scraper and a scraper pressing plate, the scraper frame body is provided with two powder falling positions, i.e. a one-way powder paving and falling position and a two-way powder paving and falling position, the powder distributor is installed on the scraper frame body, the powder distributor is provided with powder distribution cavities arranged in a left-right cross manner and stacked in sequence, the scraper frame body is provided with a one-way powder falling channel, the one-way powder falling channel is communicated with the one-way powder paving and falling position and one of the powder distribution cavities of the powder distributor respectively, and the other of the powder distribution cavities of the powder distributor cooperates with the scraper frame body to form another powder falling channel; the scraper is installed at the bottom of the scraper frame body and located between the two powder falling channels.

[0007] When the powder falling mechanism outlet is aligned with the one-way powder paving and falling position, the powder falls into the one-way powder falling channel, and one-way powder paving printing is realized; when the powder falling mechanism outlet is aligned with the two-way powder paving and falling position, the powder falls into the two powder distribution cavities respectively, the powder falling into the two powder distribution cavities is the same in amount, the powder in one of the powder distribution cavities falls into the one-way powder falling channel, and the powder in the other of the powder distribution cavities can be caught by the powder catching plate to realize two-way powder paving printing.

[0008] When the scraper frame assembly moves to the position where the powder catching plate contacts the limiting block assembly, the powder catching plate can be separated from the outlet of the other powder falling channel to make the powder fall; when the powder catching plate is separated from the limiting block assembly, the powder catching plate can automatically return to the original position.

[0009] In the above technical solution, preferably, the powder catching plate is rotatably installed at the outlet of the other powder falling channel, and the powder catching plate keeps a natural state by gravity when not subjected to force, thereby blocking the outlet of the powder falling channel; when moving to the powder paving stop position, the limiting block assembly blocks the rotation of the powder catching plate to open the outlet of the powder falling channel, and the powder falls.

[0010] In the above technical solution, further preferably, the powder catching plate is hung on the rotating shafts on the front and rear sides of the scraper frame body through a connecting plate.

[0011] In the above technical solution, further preferably, a stop plate is arranged on the side of the powder catching plate away from the limiting block assembly, so that the powder catching plate can quickly and stably return to the original position.

[0012] In the above technical solution, preferably, the limiting block assembly comprises at least one limiting block, and the limiting block is installed at the powder paving stop position of the forming platform.

[0013] In the above technical solution, preferably, the scraper is installed at the bottom of the scraper frame body through the scraper pressing plate.

[0014] The present application has the advantages and positive effects that:

[0015] 1. The cantilever single-blade bidirectional powder spreading mechanism of the present application, the single-blade leveling is simple and only needs to be leveled once, the powder receiving position can be adjusted at any time during the printing process according to the part angle, through the adjustment of the powder receiving position, the single-directional and bidirectional powder spreading states can be easily switched without changing the mechanism and opening the hatch, the printing is avoided to be stopped in the middle, the operation time is saved, and the printing efficiency is improved;

[0016] 2. The cantilever single-blade bidirectional powder spreading mechanism of the present application, the powder on the other side is held by the powder holding plate, the powder holding plate is pushed open by the limiting block at the stop position to make the powder fall down, the powder is not passed through the powder bed, and the problem of powder pollution does not exist;

[0017] 3. The cantilever single-blade bidirectional powder spreading mechanism of the present application, the gravity of the powder holding plate is automatically swung back, the state of the powder holding plate is switched without impact force, the problem that the terminal of the cantilever blade cannot be fixed for a long time and cannot withstand impact force is avoided; the mechanism runs without resistance and does not collide, and therefore is suitable for the use scene of the cantilever blade. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a structural schematic view of the cantilever single-blade bidirectional powder spreading mechanism provided by the embodiment of the present application and installed in a forming chamber;

[0019] Figure 2 is a perspective view of a blade holder assembly provided by the embodiment of the present application;

[0020] Figure 3 is a side view of the blade holder assembly provided by the embodiment of the present application;

[0021] Figure 4 is the A-A sectional view of Figure 3 ;

[0022] Figure 5 is the sectional view of another part of the blade holder assembly provided by the embodiment of the present application.

[0023] In the figure: 1, blade holder assembly; 2, limiting block assembly; 3, blade holder body; 31, one-way powder spreading and powder falling position; 32, bidirectional powder spreading and powder falling position; 33, one-way powder falling channel; 4, powder distributor; 41, powder distribution cavity; 5, powder holding plate; 51, stop plate; 6, rotating shaft; 7, connecting plate; 8, scraper; 9, scraper pressing plate; 10, forming platform; 11, powder falling mechanism. DETAILED DESCRIPTION

[0024] In order to further understand the content, characteristics and effects of the present application, the following embodiments are exemplified and described in detail as follows with reference to the accompanying drawings:

[0025] In the description of the present application, it needs to be understood that the terms "upper", "lower", "front", "back", "left", "right", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0026] In the description of the present application, it needs to be understood that the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0027] Please refer to Figures 1-5 The embodiment of the present application provides a cantilever single scraper bidirectional powder laying mechanism for laser selective melting forming, which comprises a scraper frame assembly and a limiting block assembly, the scraper frame assembly is located above a forming platform in a forming chamber, and the limiting block assembly is located on one side of the forming platform.

[0028] The scraper frame assembly comprises a scraper frame body, a powder distributor, a powder holding plate, a scraper and a scraper pressing plate, the scraper frame body is provided with two powder falling positions of unidirectional powder laying and bidirectional powder laying, the powder distributor is installed on the scraper frame body, the powder distributor is provided with powder distribution cavities arranged in cross and stacked in sequence, the scraper frame body is provided with a unidirectional powder falling channel, the unidirectional powder falling channel is communicated with the unidirectional powder laying powder falling position and one of the powder distribution cavities of the powder distributor respectively, and the other powder distribution cavity of the powder distributor cooperates with the scraper frame body to form another powder falling channel; the scraper is installed at the bottom of the scraper frame body and located between the two powder falling channels.

[0029] When the outlet of the powder falling mechanism is aligned with the unidirectional powder laying powder falling position, the powder falls into the unidirectional powder falling channel to realize unidirectional powder laying printing; when the outlet of the powder falling mechanism is aligned with the bidirectional powder laying powder falling position, the powder falls into two powder distribution cavities respectively, the amount of powder falling into the two sides is the same, the powder in one powder distribution cavity falls into the unidirectional powder falling channel, and the powder in the other powder distribution cavity can be held by the powder holding plate to prevent falling, so as to realize bidirectional powder laying printing.

[0030] When the scraper frame assembly moves to the contact between the powder holding plate and the limiting block assembly, the powder holding plate can be separated from the outlet of the other powder falling channel to make the powder fall; when the powder holding plate is separated from the limiting block assembly, the powder holding plate can automatically return to the original position.

[0031] Specifically, such as Figure 2 As shown, the powder-collecting plate is hung on the rotating shafts on the front and rear sides of the scraper frame via connecting plates. The powder-collecting plate is rotatably installed at the outlet of another powder-falling channel. When the powder-collecting plate is not under force, it remains in a natural state by gravity, blocking the outlet of the powder-falling channel. When it moves to the powder-spreading stop position, the powder-collecting plate is blocked by the limiting block assembly, opening the outlet of the powder-falling channel, allowing the powder to fall. When the scraper frame assembly returns, the powder-collecting plate automatically falls back.

[0032] A stop plate is provided on the side of the powder-collecting plate away from the limiting block assembly, so that the powder-collecting plate can quickly and stably return to its original position.

[0033] The limiting block assembly includes at least one limiting block, which is installed at the powder spreading stop position of the forming platform. When the powder collecting plate moves to the powder spreading stop position, the powder collecting plate contacts the limiting block, causing the powder collecting plate to rotate and drop the powder. After the powder collecting plate separates from the limiting block, the powder collecting plate automatically swings back to its original position by gravity.

[0034] The scraper is installed at the bottom of the scraper holder via a scraper pressure plate, making installation and fixation convenient.

[0035] This invention allows for easy switching between single and double powder spreading states without changing the mechanism or opening the hatch by adjusting the powder receiving position. The mechanism uses a powder collecting plate to collect the powder on the other side, and at the stop position, a limit block pushes the powder collecting plate open to allow the powder to fall, and then moves in the opposite direction to spread the powder. The mechanism operates without resistance and without collision, so it is suitable for use in cantilever scraper applications.

[0036] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall fall within the scope of the technical solution of the present invention.

Claims

1. A cantilevered single-scraper bidirectional powder spreading mechanism for laser selective melting and forming, characterized in that, It includes a scraper holder assembly and a limiting block assembly. The scraper holder assembly is located above the forming platform in the forming chamber, and the limiting block assembly is located on one side of the forming platform, on a different side from the powder dropping mechanism. The scraper holder assembly includes a scraper holder body, a powder distributor, a powder collecting plate, a scraper, and a scraper pressure plate. The scraper holder body has two powder dropping positions: a unidirectional powder spreading and dropping position and a bidirectional powder spreading and dropping position. The powder distributor is installed on the scraper holder body and has a structure with powder dropping chambers arranged alternately on the left and right sides and stacked sequentially. The scraper holder body has a unidirectional powder dropping channel, which is connected to the unidirectional powder spreading and dropping position and one of the powder dropping chambers of the powder distributor. The other powder dropping chamber of the powder distributor cooperates with the scraper holder body to form another powder dropping channel. The scraper is installed at the bottom of the scraper holder body and is located between the two powder dropping channels. When the powder dispensing mechanism outlet is aligned with the unidirectional powder dispensing position, the powder falls into the unidirectional powder dispensing channel, achieving unidirectional powder dispensing printing; when the powder dispensing mechanism outlet is aligned with the bidirectional powder dispensing position, the powder falls into the two powder dispensing chambers respectively, with the same amount of powder falling into both sides. The powder from one powder dispensing chamber falls into the unidirectional powder dispensing channel, while the powder from the other powder dispensing chamber can be caught by the powder collecting plate, achieving bidirectional powder dispensing printing. When the scraper holder assembly moves to the point where the powder collecting plate contacts the limiting block assembly, the powder collecting plate can separate from the outlet of another powder falling channel to allow the powder to fall. When the powder collecting plate separates from the limiting block assembly, the powder collecting plate can automatically return to its original position. The powder-collecting plate is rotatably installed at the outlet of another powder-falling channel. When the powder-collecting plate is not under force, it maintains its natural state by gravity, blocking the outlet of the powder-falling channel. When it moves to the powder-spreading stop position, the limiting block assembly prevents the powder-collecting plate from rotating, opening the outlet of the powder-falling channel and allowing the powder to fall. The powder-collecting plate is hung on the rotating shafts on the front and rear sides of the scraper frame via connecting plates.

2. The cantilevered single-scraper bidirectional powder spreading mechanism for laser selective melting and forming according to claim 1, further characterized in that, A stop plate is provided on the side of the powder-collecting plate away from the limiting block assembly, so that the powder-collecting plate can quickly and stably return to its original position.

3. The cantilevered single-scraper bidirectional powder spreading mechanism for laser selective melting and forming according to claim 1, further characterized in that, The limiting block assembly includes at least one limiting block, which is installed at the powder spreading stop position of the forming platform.

4. The cantilevered single-scraper bidirectional powder spreading mechanism for laser selective melting and forming according to claim 1, further characterized in that, The scraper is mounted on the bottom of the scraper holder via a scraper pressure plate.

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