Powder supply system and powder supply method for selective laser melting equipment

Abstract

The invention relates to the technical field of additive manufacturing, in particular to a powder supply system and method for selective laser melting equipment, the powder supply system comprises a powder spreading bin, the interior of the powder spreading bin is set to have a preset protective atmosphere so as to form an environment for laser sintering powder, and a powder scraping plane is arranged at the bottom of the powder spreading bin; and the scraper component is connected to a rail on the inner wall of the powder spreading bin. Through real-time linkage of the movable powder return bin and the powder supply bin, the powder return bin is synchronously switched along with the current powder type, meanwhile, the scraper component can achieve bidirectional powder scraping, when the scraper component scrapes the powder in a bidirectional mode, the position of the powder return bin can be dynamically adjusted according to the direction of a scraper, it is guaranteed that falling and returning powder enters the corresponding powder return bin, the powder is not scattered, and the powder supply efficiency is improved. The powder supply efficiency and the powder return efficiency are high, the purity is high, the powder can be directly recycled and reused, the scraper component is designed to have the function of temporarily storing the powder, one-time powder falling and two-way powder scraping can be achieved, and the machining efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of additive manufacturing, and more particularly to a powder feeding system and a powder feeding method for a selective laser melting equipment. Background Art

[0002] Selective laser melting (SLM) technology manufactures complex metal parts by layer-by-layer powder spreading and laser melting. However, in various scenarios, such as functional gradient materials, composite structure manufacturing, etc., dynamic switching of multiple types of powders is required to achieve additive manufacturing. Therefore, the limitations of single materials are significant, and additive manufacturing technology is developing towards dynamic switching of multiple powders.

[0003] Currently, the processing flow of multi-material SLM generally includes the following steps: Layered design and powder distribution: According to the three-dimensional model of the part, determine the powder type required for each layer (for example, the first to second layers are powder A, and the second to fourth layers are powder B). Powder feeding system switching: Release powders from multiple powder feeding bins (each bin stores one type of powder) to the surface of the forming cylinder as needed. Powder spreading and scraping: The scraper evenly spreads the powder, and the excess powder is scraped into the recycling bin. Laser melting: The laser selectively melts the powder of the current layer along a preset path to form a part cross-section. Powder recycling and circulation: The recycling bin collects the excess powder, which is screened and reused after that.

[0004] For example, an SLM forming equipment with a multi-material powder spreading device proposed in the publication number CN116117172A has its powder feeding device arranged on one side. The scraper can only perform one-way powder scraping, and multiple powders are mixed in the powder recycling bin, which is not conducive to subsequent powder screening. Therefore, people hope to develop a powder feeding system for multiple powders to improve the processing efficiency of multi-material SLM. Summary of the Invention

[0005] In view of the technical problems existing in the selective laser melting equipment in the prior art, a first aspect of the present invention provides a powder feeding system for a selective laser melting equipment, including:

[0006] A powder spreading bin, the interior of which is set to have a predetermined protective atmosphere to form an environment for laser sintering powder, and a powder scraping plane is provided at the bottom of the powder spreading bin;

[0007] A scraper component, connected to a track on the inner wall of the powder spreading bin, and can be driven to reciprocate along a first direction in which the track extends, close to the powder scraping plane;

[0008] A forming cylinder, arranged below the powder scraping plane of the powder spreading bin and communicating with the inner cavity of the powder spreading bin. A forming substrate is provided in the forming cylinder, and the forming substrate is set to move up or down in the forming cylinder. A first powder recycling area and a second powder recycling area are respectively provided on both sides of the forming cylinder, and powder recycling channels are provided in both the first powder recycling area and the second powder recycling area;

[0009] A powder supply component for quantitatively supplying more than two types of powders to the doctor blade component, and the powder supply component is located above the first powder return area and / or the second powder return area;

[0010] A powder return component, including two powder return bin groups, respectively located below the first powder return area and the second powder return area. The powder return bin group includes more than two powder return bins and a driving component for driving any one of the powder return bins to transfer to the corresponding position of the powder return channel;

[0011] A controller, electrically connected to the doctor blade component, the driving component, and the powder supply component;

[0012] Wherein, the controller is configured to control the driving component to act according to the powder type of the current powder laying layer and the position of the doctor blade component, so that the powder return bin corresponding to the current powder type is located below the powder return channel corresponding to the starting position and the ending position of the doctor blade component.

[0013] Preferably, the powder supply component includes a powder supply bin A and a first powder supply shaft arranged below the powder supply bin A, a powder supply bin B and a second powder supply shaft arranged below the powder supply bin B. The powder supply bin A is located on the first side of the forming cylinder, and the powder supply bin B is located on the second side of the forming cylinder;

[0014] The first powder supply shaft and the second powder supply shaft are electrically connected to the controller, and the controller is used to control the rotation states of the first powder supply shaft and the second powder supply shaft. When the first powder supply shaft or the second powder supply shaft rotates to a predetermined angle, the powder supply bin A or the powder supply bin B can drop powder downward.

[0015] Preferably, the powder supply component includes a powder supply bin A and a powder supply bin B. The powder supply bin A and the powder supply bin B are located on the same side of the forming cylinder, and the first powder supply shaft and the second powder supply shaft are arranged such that only the powder supply bin A or the powder supply bin B is allowed to be in the powder dropping state at the same time.

[0016] Preferably, the first powder return bin group is located below the first powder return area, and the second powder return bin group is located below the second powder return area. Wherein, a first powder dropping channel is provided in the first powder return area, and a second powder dropping channel is provided in the second powder return area.

[0017] Preferably, the two powder return bins in the powder return bin group include a powder return bin A and a powder return bin B, and the driving component is used to drive the powder return bin A or the powder return bin B to align below the first powder dropping channel or the second powder dropping channel.

[0018] Preferably, the scraper component includes a scraper mounting frame, two temporary storage funnels arranged on the scraper mounting frame, and a scraper arranged below the scraper mounting frame. A powder dropping pipe is provided below the two temporary storage funnels, and a valve is provided on the powder dropping pipe. When the valve is opened, the powder in the temporary storage funnel can fall along the powder dropping pipe to one side of the scraper. The scraper can move relative to the scraper mounting frame so that it is on the left or right side of each powder dropping pipe.

[0019] Preferably, define the powder amount used for laying one layer of powder as Q, and the capacity of the temporary storage funnel is greater than 2Q.

[0020] Preferably, a movable cover plate is provided above the temporary storage funnel, and the cover plate is used to cover one of the temporary storage funnels.

[0021] A technical solution is proposed in the second aspect of the present invention. A powder supply method for a selective laser melting device according to the above includes the following steps:

[0022] Step 1, obtain the position where the current scraper component is located;

[0023] Step 2, the scraper component completes powder laying in the form of two-way powder scraping. According to the powder type required for the printing layer to be printed, during the two-way powder scraping process, control the powder supply component to provide the required powder to the scraper component;

[0024] Among them, the powder provided by the powder supply component to the scraper component includes the powder type and / or powder amount of the current printing layer and / or the next printing layer;

[0025] During the powder supply process for the previous printing layer or the next printing layer, at the powder dropping place, the driving component drives the powder return bin corresponding to the type of the dropped powder to below the first powder dropping channel or the second powder dropping channel. At the powder returning place, the driving component drives the powder return bin corresponding to the type of the laid powder to below the first powder dropping channel or the second powder dropping channel.

[0026] Preferably, in step 2, the amount of the dropped powder before the scraper component scrapes the current printing layer is more than the amount of the powder of the current printing layer.

[0027] Compared with the prior art, the advantages of the present invention are as follows:

[0028] Through the real-time linkage of the movable powder return bin and the powder supply bin, the powder return bin is synchronously switched with the current powder type. At the same time, the scraper component can realize two-way powder scraping. When the scraper component performs two-way powder scraping, the position of the powder return bin can be dynamically adjusted according to the scraper direction to ensure that the dropped powder and the returned powder enter the corresponding powder return bin, without powder spilling. The powder supply and powder return efficiency is high, the purity is high, and it can be directly recycled and reused. Moreover, the scraper component is designed to have the function of temporarily storing powder, and can realize one-time powder dropping and two-way powder scraping, improving the processing efficiency. Description of the Drawings

[0029] The accompanying drawings are not intended to be drawn to scale. In the accompanying drawings, each identical or nearly identical component shown in each figure may be denoted by the same reference numeral. For the sake of clarity, not every component is labeled in each figure. Now, embodiments of various aspects of the present invention will be described by way of example and with reference to the accompanying drawings, wherein:

[0030] Figure 1 is a schematic structural diagram of a first powder feeding system for a selective laser melting device according to an embodiment of the present invention;

[0031] Figure 2 is a schematic structural diagram of a second powder feeding system for a selective laser melting device according to an embodiment of the present invention;

[0032] Figure 3 is a schematic structural diagram of a doctor blade component according to an embodiment of the present invention;

[0033] Figure 4 is a schematic diagram showing the powder feeding from powder feeding bin A to the doctor blade component according to an embodiment of the present invention;

[0034] Figure 5 is a schematic diagram showing the movement of the doctor blade towards the powder dropping tube side according to an embodiment of the present invention;

[0035] Figure 6 is a schematic diagram showing the scraping of the first powder A by the doctor blade component moving to the right to complete the scraping;

[0036] Figure 7 is a schematic diagram showing the powder dropping on the right side of the doctor blade according to an embodiment of the present invention;

[0037] Figure 8 is a schematic diagram showing the scraping of the first powder A by the doctor blade component moving to the left to complete the scraping;

[0038] Figure 9 is a schematic diagram showing the powder dropping on the left side of the doctor blade according to an embodiment of the present invention;

[0039] Figure 10 is a schematic diagram showing the powder feeding from powder feeding bin B to the doctor blade component according to an embodiment of the present invention. Detailed Embodiments

[0040] For a better understanding of the technical content of the present invention, specific embodiments are hereby given and described in conjunction with the accompanying drawings as follows.

[0041]

Powder Feeding System for Selective Laser Melting Device

[0042] In combination with Figure 1 and Figure 2As shown in the figure, a powder feeding system for a selective laser melting device according to the first aspect of the present invention includes a powder spreading bin 100, a doctor blade component 10, a forming cylinder 20, a powder feeding component 30, a powder recycling component 40, and a controller.

[0043] The inside of the powder spreading bin 100 is set to have a predetermined protective atmosphere to form an environment for laser sintering powder. A powder scraping plane 101 is provided at the bottom of the powder spreading bin 100.

[0044] It should be understood that an inert gas with an appropriate pressure is filled into the powder spreading bin 100 to prevent the powder from being oxidized during laser sintering.

[0045] The doctor blade component 10 is connected to a track on the inner wall of the powder spreading bin 100 and can be driven to reciprocate along the first direction in which the track extends, close to the powder scraping plane 101.

[0046] Optionally, the track not only provides guidance for the movement of the doctor blade component 10 but also can drive the doctor blade component 10 to move to different positions on the surface of the track, especially to both sides of the forming cylinder 20, waiting for the powder to fall from the powder feeding component 30, completing powder scraping, and scraping the remaining powder to the powder recycling component 40.

[0047] The forming cylinder 20 is arranged below the powder scraping plane 101 of the powder spreading bin 100 and is communicated with the inner cavity of the powder spreading bin 100. A forming substrate 21 is provided in the forming cylinder 20. The forming substrate 21 is set to move up or down in the forming cylinder 20. A first powder recycling area 103 and a second powder recycling area 102 are respectively provided on both sides of the forming cylinder 20. Powder recycling channels are provided in both the first powder recycling area 103 and the second powder recycling area 102.

[0048] Furthermore, the powder feeding component 30 is used to quantitatively supply more than two types of powder to the doctor blade component 10. The powder feeding component 30 is located above the first powder recycling area 103 and / or the second powder recycling area 102.

[0049] In this way, when the powder feeding component 30 drops powder into a predetermined area (the first powder recycling area 103 and / or the second powder recycling area 102), the doctor blade component 10 receives the powder and scrapes the powder along the powder scraping plane 101, and layer-by-layer powder spreading is completed by the layer-by-layer descent of the forming substrate 21 in the forming cylinder.

[0050] It should be understood that when each layer of powder is spread, there is excess powder that needs to be recycled after the current powder scraping is completed. Since there are more than one type of powder involved in powder spreading, if the same recycling bin is used for recycling, it is not conducive to the reuse of the powder. Therefore, the powder recycling component 40 includes two powder recycling bin groups, which are respectively located below the first powder recycling area 103 and the second powder recycling area 102. Each powder recycling bin group includes more than two powder recycling bins and a driving component 43 for driving any one of the powder recycling bins to move to the corresponding position of the powder recycling channel.

[0051] In this way, when a certain type of powder is scraped, the corresponding powder return bin is used to receive excess powder below the powder return channel, so that the type of powder in the powder return bin is single, which is conducive to later reuse. For example, the current powder return bin is connected to the powder supply component 30, and the powder after return can be directly used for powder supply.

[0052] In an optional embodiment, the driving component 43 is a linear track, which can control any one of the multiple powder return bins to be below the powder return channel.

[0053] In other embodiments, the driving component 43 may also be a circular track, such as a circular track surrounding the outside of the forming cylinder 20, and any one of the multiple powder return bins on the track may be controlled to be located below a suitable powder return channel.

[0054] Furthermore, the controller is electrically connected to the scraper component 10, the driving component 43, and the powder supply component 30, wherein the controller is configured to control the action of the driving component 43 according to the powder type of the current powder layer and the position of the scraper component 10, so that the powder return bin corresponding to the current powder type is located below the powder return channel corresponding to the starting position and the end position of the scraper component 10.

[0055] In this way, by controlling the movement of the powder return bin, a powder return bin matching the powder type can be used under the corresponding powder return channel to receive the powder according to the powder position and powder type when the powder falls; and a powder return bin matching the powder type can be used under the corresponding powder return channel to receive the powder according to the powder type and the position of the end of the powder scraping, thereby ensuring the consistency of powder supply and recovered powder.

[0056] It can be understood that the powder supply component 30 is intended to provide different types of powders and different amounts of powders to the scraper component 10 at appropriate locations.

[0057] Combination Figure 1 As shown, in an optional embodiment, taking the powder supply component 30 providing two kinds of powders as an example, the powder supply component 30 includes a powder supply bin A31 and a first powder supply shaft 33 arranged below the powder supply bin A31, a powder supply bin B32 and a second powder supply shaft 34 arranged below the powder supply bin B32, the powder supply bin A31 is located on the first side of the forming cylinder 20, and the powder supply bin B32 is located on the second side of the forming cylinder 20.

[0058] The powder supply bin A31 is used to contain the first type of powder, and the powder supply bin B32 is used to contain the second type of powder.

[0059] Further, the first powder supply shaft 33 and the second powder supply shaft 34 are electrically connected to a controller, which is configured to control the rotation states of the first powder supply shaft 33 and the second powder supply shaft 34. When the first powder supply shaft 33 or the second powder supply shaft 34 rotates to a predetermined angle, the powder supply bin A 31 or the powder supply bin B 32 can drop powder downward.

[0060] In this way, when the blade member 10 moves below the powder supply bin A 31, the first type of powder can be provided to the blade member 10 through the powder supply bin A 31. When the blade member 10 moves below the powder supply bin B 32, the second type of powder can be provided to the blade member 10 through the powder supply bin B 32.

[0061] Combined with Figure 2 As shown, in other embodiments, taking the powder supply component 30 providing two types of powders as an example, the powder supply component 30 includes a powder supply bin A 31 and a powder supply bin B 32. The powder supply bin A 31 and the powder supply bin B 32 are located on the same side of the forming cylinder 20. The first powder supply shaft 33 and the second powder supply shaft 34 are arranged such that only the powder supply bin A 31 or the powder supply bin B 32 is allowed to be in the powder dropping state at the same time.

[0062] In this way, the powder supply component 30 needs to provide the blade member 10 with the powder dropping amount twice at one time to meet the powder demand for the two-way powder spreading of the blade member 10. When the powder type for one-time powder spreading back and forth is one type, the powder supply component 30 provides twice the powder amount of one type of powder to the blade member 10. When the powder types for one-time powder spreading back and forth are two types, the powder supply component 30 continuously provides two types of powders to the blade member 10, and the powder amount of each type of powder meets the powder spreading demand for one layer.

[0063] It should be understood that the powder supply component 30 includes but is not limited to two powder supply bins. The number of powder supply bins is set according to requirements. For example, a powder supply bin A and a powder supply bin B are arranged on one side, and a powder supply bin C and a powder supply bin D are arranged on the other side. At the same time, the type of the powder return bin is kept matching the type of the powder supply bin, and preferably, it is twice the number of the powder supply bins.

[0064] In the above embodiments, combined with Figure 1 and Figure 2 As shown, the first powder return bin group is located below the first powder return area 103, and the second powder return bin group is located below the second powder return area 102. Among them, a first powder dropping channel 401 is provided in the first powder return area 103, and a second powder dropping channel 402 is provided in the second powder return area 102.

[0065] Further, the two powder return bins in the powder return bin group include a powder return bin A 41 and a powder return bin B 42. The driving component 43 is configured to drive the powder return bin A 41 or the powder return bin B 42 to align below the first powder dropping channel 401 or the second powder dropping channel 402.

[0066] In this way, no matter whether the blade component 10 scrapes powder from the left side to the right side or from the right side to the left side, the excess powder will be received by the corresponding powder return bin.

[0067] Specifically, taking the first layer to be paved with powder as the first powder A and the second layer as the second powder B as an example, as shown in Figure 1 , initially, the blade component 10 is in the left position (the first powder return area 103). The powder supply bin A31 in the powder supply component 30 supplies the first powder A to the blade component 10. At this time, the powder return bin A41 is located below the first powder falling channel 401, and the powder return bin A41 is also located below the second powder falling channel 402. The blade component 10 scrapes the powder on the first layer, so that the first powder A covers the first layer of the forming substrate 21. The excess powder enters the powder return bin A4 through the second powder falling channel 402; then, the powder return bin B42 is switched to be located below the first powder falling channel 401 and the second powder falling channel 402. The powder supply component 30 supplies the second powder B to the blade component 10. The blade component 10 scrapes the powder on the second layer, so that the second powder B covers the second layer of the forming substrate 21. The excess powder falls from the first powder falling channel 401 into the powder return bin B42.

[0068] In the above embodiment, the blade component 10 includes a blade mounting frame 15, two temporary storage funnels 11 arranged on the blade mounting frame 15, and a blade 16 arranged below the blade mounting frame 15.

[0069] Preferably, it is defined that the powder amount used for paving one layer of powder is Q, and the capacity of the temporary storage funnel 11 is greater than 2Q.

[0070] In this way, the requirements for powder temporary storage can be met by the two temporary storage funnels 11, and one-time powder falling can be realized to complete bidirectional powder scraping.

[0071] For example, if the two layers of powder to be paved are both the first powder A or the second powder B, then the powder supply component 30 supplies a single powder (the first powder A or the second powder B) that can be used for paving two layers to one of the temporary storage funnels 11, and the blade 16 is driven by the movement of the blade mounting frame 15 to complete bidirectional powder scraping; if the first layer of the two layers of powder to be paved is the first powder A and the second layer is the second powder B, then the powder supply component 30 places the first powder A in one of the temporary storage funnels 11 respectively, and the second powder B in the other temporary storage funnel 11.

[0072] Furthermore, powder falling pipes 13 are arranged below the two temporary storage funnels 11, and valves 12 are arranged on the powder falling pipes 13. When the valves 12 are opened, the powder in the temporary storage funnels 11 can fall along the powder falling pipes 13 to one side of the blade 16, and the blade 16 can move relative to the blade mounting frame 15 so that it is located on the left or right side of each powder falling pipe 13.

[0073] Thus, by controlling the state of the valve 12, the powder falling amount from the temporary hopper 11 to the powder dropping pipe 13 can be controlled. Before powder dropping, first, according to the position of the current scraper component 10, the position of the scraper 16 is controlled to ensure that the powder is on the side where the scraper 16 is about to move.

[0074] Further, a movable cover plate 14 is provided above the temporary hopper 11, and the cover plate 14 is used to cover one of the temporary hoppers 11.

[0075] Thus, the temporary hopper 11 can be covered by the cover plate 14 to prevent another type of powder from entering the current temporary hopper 11 during powder dropping.

[0076] In a specific embodiment, taking the powder spreading of the first powder A for the next two layers as an example.

[0077] Combined with Figure 4 As shown, at this time, the powder spreading of the current layer is about to be completed, the powder type is the first powder A, the scraper component 10 is on the left side, and the left powder supply bin A31 is used to supply the first powder A to the scraper component 10. At this time, the powder return bin A41 moves to below the powder dropping channel to recover the excess first powder A during powder dropping.

[0078] Combined with Figure 5 As shown, at this time, the temporary hopper 11 on the right side is covered by the cover plate 14, and the temporary hopper 11 on the left side is below the powder supply bin A31 and receives the first powder A falling from the powder supply bin A31. Since the scraper component 10 needs to move to the right for powder spreading, therefore, the scraper 16 moves to the left, making the powder dropping pipe 13 on the right side of the scraper 16, and by controlling the opening and closing of the valve 12, the powder dropping amount is half of the capacity of the temporary hopper 11.

[0079] Combined with Figure 6 and Figure 7 As shown, the scraper component 10 moves to the right. At the end of the scraper component 10, the powder return bin A41 is below the powder dropping channel. When the scraper component 10 scrapes the powder to the right, the excess powder drops into the powder return bin A41.

[0080] Combined with Figure 8 and Figure 9 As shown, the scraper 16 moves to the right side of the powder dropping pipe 13, and then by controlling the opening and closing of the valve 12, the remaining powder is controlled to drop. The scraper component 10 moves from the right side to the left side to complete double - direction powder scraping.

[0081] In other embodiments, taking the alternating powder spreading of the first powder A and the second powder B for the next two layers as an example.

[0082] Combined with Figure 4As shown, at this time, the powder spreading of the current layer is about to be completed. The powder type is the first powder A. The doctor blade component 10 is on the left side. The first powder A is provided to the doctor blade component 10 by the powder supply bin A31 on the left side. At this time, the powder return bin A41 moves to below the powder falling channel to recover the excess first powder A during powder falling.

[0083] Combined with Figure 6 As shown, the doctor blade component 10 moves to the right side. At the end of the doctor blade component 10, the powder return bin A41 is below the powder falling channel. When the doctor blade component 10 scrapes the powder to the right side, the excess powder drops into the powder return bin A41.

[0084] Combined with Figure 10 As shown, the second powder B is provided to the doctor blade component 10 by the powder supply bin B32 on the right side. At this time, the powder return bin B42 moves to below the powder falling channel, and the excess second powder B during powder falling is recovered through the powder return bin B42 on the right side. Moreover, when the doctor blade component 10 completes the powder spreading of the second powder B for the current powder spreading layer, the excess second powder B is recovered through the powder return bin B42 on the left side.

[0085]

Powder Supply Method for Selective Laser Melting Equipment

[0086] In the second aspect of the present invention, a technical solution is proposed. A powder supply method for a selective laser melting equipment according to the above includes the following steps:

[0087] Step 1: Obtain the position where the current doctor blade component 10 is located;

[0088] Step 2: The doctor blade component 10 completes powder spreading in the form of bidirectional powder scraping. According to the powder type required for the printing layer to be printed, during the bidirectional powder scraping process, control the powder supply component 30 to provide the required powder to the doctor blade component 10;

[0089] Among them, the powder provided by the powder supply component 30 to the doctor blade component 10 includes the powder type and / or powder amount of the current printing layer and / or the next printing layer;

[0090] During the powder supply process for the previous printing layer or the next printing layer, at the powder falling position, the driving component 43 drives the powder return bin corresponding to the type of the falling powder to below the first powder falling channel 401 or the second powder falling channel 402. At the powder returning position, the driving component 43 drives the powder return bin corresponding to the type of the laid powder to below the first powder falling channel 401 or the second powder falling channel 402.

[0091] In an optional embodiment, in step 2, the printing layer to be printed can be the current printing layer or the current printing layer and the next printing layer. That is, the powder required for one or two layers can be provided to the doctor blade component 10 through the powder supply component 30. That is, it is possible to powder fall and print the current layer at one time, or it is also possible to powder fall and print two layers at one time.

[0092] When powder is dropped from the powder supply component 30, it is necessary to correspond the powder return bin below the powder dropping channel at the position where the current powder supply component 30 is located to the type of the currently dropped powder. When the scraper component 10 scrapes the powder,

[0093] Further, in step 2, the amount of powder dropped before the scraper component 10 scrapes the current printing layer is more than the amount of powder of the current printing layer.

[0094] In this way, it is avoided that the amount of powder in the current printing layer is insufficient, the powder spreading quality is ensured through the powder dropping margin, and the control difficulty of the powder dropping amount during the process of dropping powder once and printing twice can also be reduced. The excess powder is collected through the corresponding powder return bin.

[0095] In a specific embodiment, taking the powder spreading of the first powder A for the next two layers as an example.

[0096] Combined with Figure 4 As shown, at this time, the powder spreading of the current layer is about to be completed, the powder type is the first powder A, the scraper component 10 is on the left side, and the left powder supply bin A31 is used to supply the first powder A to the scraper component 10. At this time, the powder return bin A41 moves to below the powder dropping channel to recover the excess first powder A during powder dropping.

[0097] Combined with Figure 5 As shown, at this time, the temporary funnel 11 on the right side is covered by the cover plate 14, and the temporary funnel 11 on the left side is under the powder supply bin A31 and receives the first powder A dropped from the powder supply bin A31. Since the scraper component 10 needs to move to the right for powder spreading, therefore, the scraper 16 moves to the left, so that the powder dropping pipe 13 is on the right side of the scraper 16, and by controlling the opening and closing of the valve 12, the powder dropping amount is half of the capacity of the temporary funnel 11.

[0098] Combined with Figure 6 and Figure 7 As shown, the scraper component 10 moves to the right. At the end of the scraper component 10, the powder return bin A41 is below the powder dropping channel. When the scraper component 10 scrapes the powder to the right, the excess powder falls into the powder return bin A41.

[0099] Combined with Figure 8 and Figure 9 As shown, the scraper 16 moves to the right side of the powder dropping pipe 13, and then by controlling the opening and closing of the valve 12, the remaining powder is controlled to drop. The scraper component 10 moves from the right to the left to complete the two-way powder scraping.

[0100] In other embodiments, taking the alternating powder spreading of the first powder A and the second powder B for the next two layers as an example.

[0101] Combined with Figure 4As shown, at this time, the powder spreading of the current layer is about to be completed. The powder type is the first powder A. The blade component 10 is on the left side. The left powder supply bin A31 is used to supply the first powder A to the blade component 10. At this time, the powder return bin A41 moves to below the powder dropping channel to recover the excess first powder A during powder dropping.

[0102] Combined with Figure 6 As shown, the blade component 10 moves to the right side. At the end of the blade component 10, the powder return bin A41 is located below the powder dropping channel. When the blade component 10 scrapes the powder to the right side, the excess powder drops into the powder return bin A41.

[0103] Combined with Figure 10 As shown, the right powder supply bin B32 is used to supply the second powder B to the blade component 10. At this time, the powder return bin B42 moves to below the powder dropping channel. The excess second powder B during powder dropping is recovered through the right powder return bin B42. Moreover, when the blade component 10 completes the powder spreading of the second powder B for the current powder spreading layer, the excess second powder B is recovered through the left powder return bin B42.

[0104] Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Those with ordinary knowledge in the technical field to which the present invention pertains can make various modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to what is defined by the claims.

Claims

1. A powder supply system for laser selective melting equipment, characterized in that: include: A powder spreading bin (100) is provided with a predetermined protective atmosphere inside to form an environment for laser sintering powder, and a powder scraping plane (101) is provided at the bottom of the powder spreading bin (100); A scraper component (10) is connected to a track on the inner wall of the powder spreading bin (100) and can be driven to reciprocate along a first direction extending along the track and close to the powder scraping plane (101); A forming cylinder (20) is arranged below the powder scraping plane (101) of the powder spreading bin (100) and is connected to the inner cavity of the powder spreading bin (100). A forming substrate (21) is arranged in the forming cylinder (20). The forming substrate (21) is arranged to move upward or downward in the forming cylinder (20). A first powder return area (103) and a second powder return area (102) are respectively arranged on both sides of the forming cylinder (20). Both the first powder return area (103) and the second powder return area (102) are provided with powder return channels. A powder supply component (30) is used to quantitatively supply two or more types of powder to the scraper component (10), and the powder supply component (30) is located above the first powder return area (103) and / or the second powder return area (102); A powder return component (40) includes two powder return bin groups, which are respectively located below the first powder return area (103) and the second powder return area (102), wherein the powder return bin group includes more than two powder return bins and a driving component (43) for driving any one of the powder return bins to move to a corresponding position of the powder return channel; A controller electrically connected to the scraper component (10), the driving component (43), and the powder supply component (30); The controller is configured to control the action of the driving component (43) according to the powder type of the current powder layer and the position of the scraper component (10), so that the powder return bin corresponding to the current powder type is located below the powder return channel corresponding to the starting position and the ending position of the scraper component (10).

2. The powder supply system for selective laser melting equipment according to claim 1, characterized in that: The powder supply component (30) comprises a powder supply bin A (31) and a first powder supply shaft (33) arranged below the powder supply bin A (31), a powder supply bin B (32) and a second powder supply shaft (34) arranged below the powder supply bin B (32), wherein the powder supply bin A (31) is located on a first side of the forming cylinder (20), and the powder supply bin B (32) is located on a second side of the forming cylinder (20); The first powder supply shaft (33) and the second powder supply shaft (34) are electrically connected to the controller, and the controller is used to control the rotation state of the first powder supply shaft (33) and the second powder supply shaft (34). When the first powder supply shaft (33) or the second powder supply shaft (34) rotates to a predetermined angle, the powder supply bin A (31) or the powder supply bin B (32) can drop powder downward.

3. The powder supply system for selective laser melting equipment according to claim 1, characterized in that: The powder supply component (30) comprises a powder supply bin A (31) and a powder supply bin B (32), wherein the powder supply bin A (31) and the powder supply bin B (32) are located on the same side of the forming cylinder (20), and the first powder supply shaft (33) and the second powder supply shaft (34) are configured to allow only the powder supply bin A (31) or the powder supply bin B (32) to be in a powder dropping state at the same time.

4. The powder supply system for selective laser melting equipment according to claim 1, characterized in that: The first powder return bin group is located below the first powder return area (103), and the second powder return bin group is located below the second powder return area (102), wherein the first powder return area (103) is provided with a first powder drop channel (401), and the second powder return area (102) is provided with a second powder drop channel (402).

5. The powder supply system for selective laser melting equipment according to claim 4, characterized in that: The two powder return bins in the powder return bin group include a powder return bin A (41) and a powder return bin B (42), and the driving component (43) is used to drive the powder return bin A (41) or the powder return bin B (42) to align below the first powder drop channel (401) or the second powder drop channel (402).

6. The powder supply system for selective laser melting equipment according to any one of claims 1 to 5, characterized in that: The scraper component (10) comprises a scraper mounting frame (15), two temporary storage funnels (11) arranged on the scraper mounting frame (15), and a scraper (16) arranged below the scraper mounting frame (15); a powder falling pipe (13) is arranged below the two temporary storage funnels (11); a valve (12) is arranged on the powder falling pipe (13); when the valve (12) is opened, powder in the temporary storage funnel (11) can fall along the powder falling pipe (13) to one side of the scraper (16); the scraper (16) can move relative to the scraper mounting frame (15) so as to be located on the left or right side of each powder falling pipe (13).

7. The powder supply system for selective laser melting equipment according to claim 6, characterized in that: The amount of powder used to lay a layer of powder is defined as Q, and the capacity of the temporary storage funnel (11) is greater than 2Q.

8. The powder supply system for selective laser melting equipment according to claim 6, characterized in that: A movable cover plate (14) is provided above the temporary storage funnel (11), and the cover plate (14) is used to cover one of the temporary storage funnels (11).

9. The powder supply method for selective laser melting equipment according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step 1, obtaining the current position of the scraper component (10); Step 2, the scraper component (10) completes the powder spreading in the form of bidirectional powder scraping. According to the type of powder required for the printing layer to be printed, during the bidirectional powder scraping process, the powder supply component (30) is controlled to provide the required powder to the scraper component (10); The powder provided by the powder supply component (30) to the scraper component (10) includes the type and amount of powder of the current printing layer and / or the powder of the next printing layer; During the powder supply process of the previous printing layer or the next printing layer, at the powder dropping location, the driving component (43) drives the powder return bin of the type corresponding to the powder dropping to below the first powder dropping channel (401) or the second powder dropping channel (402); at the powder returning location, the driving component (43) drives the powder return bin of the type of the laid powder to below the first powder dropping channel (401) or the second powder dropping channel (402).

10. The powder supply method for selective laser melting equipment according to claim 9, characterized in that: In step 2, the amount of powder dropped by the scraper component (10) before scraping the current printed layer is greater than the amount of powder in the current printed layer.

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