Powder supply method, three-dimensional printing method, and three-dimensional printing system
By setting up a powder supply tank and powder supply components in the 3D printing system and optimizing the powder supply process using an image acquisition device, the problem of powder waste in the prior art has been solved, and the powder utilization rate has been improved.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- XIAMEN HANIN CO LTD
- Filing Date
- 2025-10-13
- Publication Date
- 2026-05-15
AI Technical Summary
In existing 3D printing systems, the amount of powder that the build unit needs to carry is far greater than the actual requirement, because the overflowing powder cannot be reintroduced into the powder supply tank, resulting in waste.
Powder supply troughs and powder supply components are set on both sides of the construction platform. The powder supply component on the powder supply side supplies powder by lifting, and the powder supply component on the powder receiving side receives the overflowing powder by lowering. The powder supply process is optimized by measuring the diffusion distance through an image acquisition device, and the lifting and lowering distances of the powder supply components are controlled to reduce powder waste.
By optimizing the powder supply method, the amount of powder that the building blocks need to carry is reduced, the powder utilization rate is improved, and powder waste is avoided.
Smart Images
Figure CN2025127355_15052026_PF_FP_ABST
Abstract
Description
A powder supply method, a 3D printing method, and a 3D printing system Technical Field
[0001] This application relates to the field of 3D printing, specifically to a powder supply method, a 3D printing method, and a 3D printing system. Background Technology
[0002] Existing 3D printing systems include build units and a printer. The build unit includes a build body, a build platform, and two powder supply units. The build body has a build slot, two powder supply slots, and two powder overflow slots. The build slot is located between the two powder supply slots along a first direction, and the powder supply slots are located between the build platform and their corresponding powder overflow slots along the first direction. The build platform is located within the build slot and moves up and down relative to the build body, while the powder supply units are located within the powder supply slots and move up and down relative to the build body. The build slot and the progressively descending build platform together enclose a build space for forming a 3D printed part. The powder supply units supply powder by lifting. The powder supply slots are used to hold the powder used as printing material. The powder overflow slots are used to hold the powder that overflows from the build platform during placement. The printer includes a printer body, a powder placement mechanism, a printing mechanism, and a controller. The printer body is adapted to attach the build unit. The powder placement mechanism reciprocates relative to the printer body along the placement direction to place the powder supplied by the powder supply units onto the build platform. When the build unit is attached to the printer body, the placement direction is the same as the first direction. The printing mechanism is used to print powder on the build platform. Specifically, the printing mechanism has an ejector head and a flux lamp. The ejector head selectively sprays flux onto the powder on the build platform, and the flux lamp causes the powder to agglomerate. The printing mechanism moves relative to the printer body along the printing direction, which is generally perpendicular to the laying direction. The controller is signal-connected to the powder laying mechanism and the printing mechanism. When the build unit is attached to the printer body, the controller is signal-connected to the build platform and the two powder supply units. This signal connection can be electrical or wireless. The controller achieves layer-by-layer printing by controlling the build platform, powder supply units, powder laying mechanism, and printing mechanism. Specifically, each layer of printing includes a sequential powder supply step, a laying step, and a printing step. The powder supply step includes the build platform descent process and the powder supply process. The build platform descent process and the powder supply process can be performed in parallel or sequentially; when performed sequentially, there is no distinction in order. During the build platform descent, the controller lowers the platform by a predetermined distance. During powder supply, the controller raises the powder supply component closest to the powder spreading mechanism. In the spreading step, the controller moves the powder spreading mechanism along the spreading direction, passing through two powder supply troughs and spreading powder onto the build platform. Powder overflowing from the build platform eventually falls into the overflow trough. In the printing step, the controller moves the printing mechanism along the printing path. Simultaneously, the nozzle selectively sprays flux, and the flux lamp sinters the powder coated with flux.
[0003] The drawback of the above technical solution is that, since the powder overflowing from the build platform enters the powder overflow tank, and the powder in the powder overflow tank cannot re-enter the powder supply tank, the amount of powder that the build unit needs to carry is much greater than the amount of powder actually required for 3D printing. Summary of the Invention
[0004] The purpose of this application is to overcome the aforementioned defects or problems in the prior art and to provide a powder supply method, a 3D printing method, and a 3D printing system, which, compared to the prior art, require less powder to be carried by the building blocks.
[0005] To achieve the above objectives, the following technical solution is adopted:
[0006] The first technical solution relates to a powder supply method for supplying powder for 3D printing to a powder spreading mechanism, so that the powder spreading mechanism spreads the powder onto a building platform along the spreading direction. The building platform is provided with powder supply slots and powder supply components on both sides along the spreading direction. The powder supply slots are used to hold the powder, and the powder supply components are located within the corresponding powder supply slots and move up and down relative to the powder supply slots. Each time powder is supplied, the powder supply component on the powder supply side supplies powder by lifting, and the powder supply component on the powder receiving side receives the powder overflowing from the building platform by lowering. The powder supply side is the side where the powder spreading mechanism passes first during the spreading process, and the powder receiving side is the side where the powder spreading mechanism passes later during the spreading process.
[0007] The second technical solution is based on the first technical solution, wherein, each time powder is supplied, the lifting distance of the powder supply component on the powder supply side is determined according to the amount of powder received by the corresponding powder supply trough when the previous powder spreading mechanism spread a layer of powder.
[0008] The third technical solution is based on the second technical solution, wherein the descent distance of the powder supply component on the receiving side is consistent each time powder is supplied.
[0009] The fourth technical solution is based on the third technical solution, wherein the amount of powder received by the powder supply tank when the powder spreading mechanism spreads a layer of powder is characterized by the spread distance of the received powder along the spreading direction; if the spread distance is less than a threshold, the lifting distance is the first distance; if the spread distance is greater than the threshold, the lifting distance is the second distance; if the spread distance is equal to the threshold, the lifting distance is either the first distance or the second distance; the first distance is greater than the second distance.
[0010] The fifth technical solution is based on the fourth technical solution, wherein the diffusion distance is the average distance between the edge line formed by the powder received by the powder supply trough when the powder spreading mechanism spreads a layer of powder along the spreading direction and the trough edge of the powder supply trough near the construction platform.
[0011] The sixth technical solution is based on the fifth technical solution, wherein the diffusion distance is obtained by an image of the upper surface of the powder in the powder supply trough after a layer of powder is laid by the powder spreading mechanism using an image acquisition device.
[0012] The seventh technical solution is based on the sixth technical solution, wherein the field of view of the image acquisition device covers the upper surface of the construction platform and the two powder supply slots.
[0013] The eighth technical solution relates to a three-dimensional printing method, which obtains a three-dimensional printed part by printing layer by layer; each layer of printing sequentially includes a powder supply step, a laying step, and a printing step; the powder supply step includes a construction platform descent process and a powder supply process, the laying step is used to lay powder onto the construction platform, and the printing step is used to selectively sinter the powder laid onto the construction platform; the powder supply process adopts the powder supply method as described in any one of the first to fifth technical solutions.
[0014] The ninth technical solution relates to a three-dimensional printing method, which obtains a three-dimensional printed part by printing layer by layer; each layer of printing sequentially includes a powder supply step, a laying step, an image acquisition step, and a printing step; the powder supply step includes a construction platform descent process and a powder supply process, the laying step is used to lay powder onto the construction platform, the image acquisition step is used to acquire an image of the upper surface of the powder in the powder supply tank, and the printing step is used to selectively sinter the powder laid onto the construction platform; wherein, the powder supply process adopts the powder supply method as described in any one of the fourth to seventh methods, and the diffusion distance is obtained from the image acquired during the printing of the previous layer.
[0015] The tenth technical solution relates to a 3D printing system, which includes a build unit and a printer. The build unit includes a build body, a build platform, and two powder supply components. The build body has a build slot and powder supply slots located on both sides of the build slot. The build platform is located in the build slot and moves up and down relative to the build body. The powder supply components are located in the corresponding powder supply slots and move up and down relative to the build body. The printer includes a printer body, a powder spreading mechanism, an image acquisition device, and a controller. The printer body is adapted to attach the build unit. The powder spreading mechanism reciprocates relative to the printer body along the spreading direction. When the build unit is attached to the printer body, the spreading direction is the same as the laying direction of the build slot and the powder supply slots. The image acquisition device is used to acquire images of the powder surface in the build slot and the two powder supply slots. The controller is signal-connected to the powder spreading mechanism, the image acquisition device, the build platform of the build unit attached to the printer body, and the two powder supply components. The controller receives images. The image acquisition device acquires images and controls the movement of the powder spreading mechanism, the build platform, and two powder supply components to achieve layer-by-layer printing. During each layer printing, the controller first controls the build platform to descend by a first preset distance, and controls the powder supply component on the powder supply side to rise by a lifting distance and controls the powder supply component on the powder receiving side to descend by a second preset distance. Then, the powder spreading mechanism is controlled to sequentially pass through the powder supply slots on the powder supply side and the powder receiving side along the laying direction. Next, the image acquisition device acquires and receives images. The controller obtains the diffusion distance of the powder received in the powder supply slot on the receiving side along the laying direction based on the received images. During the first layer printing, the lifting distance is the first distance. During each subsequent layer printing, the lifting distance is determined based on the diffusion distance acquired during the previous layer printing. When the diffusion distance is less than a threshold, the lifting distance is the first distance; when the diffusion distance is greater than the threshold, the lifting distance is the second distance; when the diffusion distance is equal to the threshold, the lifting distance is either the first distance or the second distance; the first distance is greater than the second distance.
[0016] The eleventh technical solution is based on the ninth technical solution, wherein the printer further includes a printing mechanism for printing powder on the build platform, and the controller is also signal-connected to the printing mechanism; during each layer printing, the controller controls the printing mechanism to print after receiving the image; the build body is also provided with two powder overflow grooves, the two powder overflow grooves are set with two powder supply grooves, and the powder supply grooves are located between the build platform and the corresponding powder overflow grooves along the laying direction.
[0017] Compared with existing technologies, the above solution has the following beneficial effects:
[0018] In the first technical solution, by lowering the powder supply component on the powder receiving side, at least most of the powder overflowing from the build platform is received into the powder supply trough. Compared to the prior art, which receives the powder overflowing from the build platform into the overflow trough, at least most of the overflowing powder can be reused for laying onto the build platform. Therefore, the build unit needs to carry less powder than in the prior art.
[0019] In the second technical solution, the lifting distance of the powder supply component on the powder supply side is determined by the amount of powder received by the corresponding powder supply trough when the powder spreading mechanism lays a layer of powder. Compared with the case where the lifting distance remains unchanged, the amount of powder overflowing from the construction platform and falling into the overflow trough can be further reduced, thus further reducing the amount of powder that the construction unit needs to carry.
[0020] The third to fifth technical solutions are preferred embodiments of the second technical solution. Under the premise that the descent distance of the powder supply component on the receiving side is consistent, the amount of powder received by the powder supply trough when the powder spreading mechanism lays a layer of powder is represented by the diffusion distance. Compared with other calculation methods, this reduces the amount of calculation required to determine the amount of powder received. Furthermore, the lifting distance is limited to the first and second distances, which optimizes the control logic for the lifting distance and avoids overly complex control logic.
[0021] The sixth and seventh technical solutions, which obtain the diffusion distance from the image acquired by the image acquisition device, are preferred implementations for measuring diffusion distance. This is mainly based on the fact that the received powder can form a clear edge line on the surface of the powder in the powder supply tank.
[0022] The eighth and ninth technical solutions have the technical effects of the technical solutions they reference.
[0023] The tenth technical solution is a specific implementation method for the powder supply method defined in the sixth and seventh technical solutions.
[0024] The eleventh technical solution incorporates an overflow trough, which can receive excess powder and prevent waste in the event that the powder overflowing from the construction platform cannot be fully received by the powder supply trough on the receiving side. Attached Figure Description
[0025] To more clearly illustrate the technical solutions of the embodiments, the accompanying drawings used are briefly described below:
[0026] Figure 1 is a front view of the 3D printing system in the embodiment;
[0027] Figure 2 is a cross-sectional view along line AA of Figure 1;
[0028] Figure 3 is a schematic diagram of each step in the printing process for each layer.
[0029] Key reference numerals: 1. 3D printing system; 100. Building block; 110. Building body; 111. Building groove; 112. Toner supply groove; 113. Toner overflow groove; 120. Building platform; 130. Toner supply component; 200. Printer; 210. Printer body; 220. Toner spreading mechanism; 230. Printing mechanism; 231. Jet head; 232. Fluxing lamp; 240. Image acquisition device. Detailed Implementation
[0030] Unless otherwise specified, the terms “first,” “second,” or “third,” etc., in the claims and description are used to distinguish different objects and not to describe a particular order.
[0031] Unless otherwise specified, in the claims and description, the terms “center,” “lateral,” “longitudinal,” “horizontal,” “vertical,” “top,” “bottom,” “inner,” “outer,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “clockwise,” “counterclockwise,” etc., indicate the orientation or positional relationship based on the orientation and positional relationship shown in the drawings, and are only for the purpose of simplifying the description, and do not imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation.
[0032] Unless otherwise specified in the claims and description, the terms "fixed connection" or "fixed connection" shall be interpreted broadly to mean any connection in which there is no displacement or relative rotation relationship between the two parties, including non-removable fixed connection, detachable fixed connection, integral connection, and fixed connection by other means or components.
[0033] In the claims and description, unless otherwise specified, the terms "comprising," "having," and variations thereof mean "including but not limited to."
[0034] In the claims and description, unless otherwise specified, the term "have" means that a technical feature that follows is part of a technical feature that precedes it.
[0035] The technical solutions in the embodiments will now be described clearly and completely with reference to the accompanying drawings.
[0036] Referring to Figures 1 and 2, which illustrate a 3D printing system 1 in an embodiment. As shown in Figures 1 and 2, the 3D printing system 1 includes a building block 100 and a printer 200.
[0037] As shown in Figure 2, the build unit 100 includes a build body 110, a build platform 120, and two powder supply components 130. The build body 110 has wheels and is movable. The build platform 120 and the two powder supply components 130 are both installed inside the build body 110. The build body 110 is provided with a build groove 111, two powder supply grooves 112, and two powder overflow grooves 113 along a first direction. The build groove 111 is used to form the build space of the 3D printed part. The powder supply grooves 112 are used to contain powder as printing material. The powder overflow grooves 113 are used to contain powder overflowing from the build platform 120 and the powder supply grooves 112. The two powder supply grooves 112 and the two powder overflow grooves 113 are arranged correspondingly to each other. The build groove 111 is located between the two powder supply grooves 112 along the first direction, and the powder supply grooves 112 are located between the build platform 111 and the corresponding powder overflow grooves 113 along the first direction. The upper surfaces of the build slot 111, the two powder supply slots 112, and the two powder overflow slots 113 are all flush with a horizontal plane perpendicular to the Z-axis. The build platform 120 is located within the build slot 111 and rises and falls relative to the build body 110. The build slot 111 and the progressively descending build platform 120 together enclose a build space for forming the 3D printed part. Two powder supply components 130 are correspondingly arranged with the two powder supply slots 112. The powder supply components 130 are located within their respective powder supply slots 112 and rise and fall relative to the build body 110. Powder is contained in the powder-containing space enclosed by the powder supply slots 112 and the powder supply components 130.
[0038] As shown in Figures 1 and 2, the printer 200 includes a printer body 210, a toner spreading mechanism 220, a printing mechanism 230, an image acquisition device 240, and a controller (not shown in the figures). The printer body 210 is adapted to attach the build unit 100. When the build unit 100 is attached to the printer body 210, the build slot 111, two toner supply slots 112, and two toner overflow slots 113 are arranged along the Y-axis direction, that is, the orientation of the build unit 100 is maintained by the printer body 210 in the Y-axis direction. The toner spreading mechanism 220 is used to spread the powder in the toner supply slots 112 onto the build platform 120. The toner spreading mechanism 220 is equipped with a toner spreading roller, and the toner spreading mechanism 220 reciprocates relative to the printer body 210 along the spreading direction, which is the Y-axis direction. Therefore, when the build unit 100 is attached to the printer body 210, the powder spreading mechanism 220 lays powder in the same direction as the build slot 111, the two powder supply slots 112, and the two overflow slots 113. The lower edge of the powder spreading roller is substantially flush with the upper surfaces of the build slot 111, the two powder supply slots 112, and the two overflow slots 113. Each time the powder spreading mechanism 220 moves, the powder spreading roller passes over the following components in sequence: the overflow slot 113 on the powder supply side, the powder supply slot 112 on the powder supply side, the build platform 120, the powder supply slot 112 on the powder receiving side, and the overflow slot 113 on the powder receiving side. Here, the powder supply side refers to the side where the powder spreading mechanism 220 passes the powder supply slot 112 first, and the powder receiving side refers to the side where the powder spreading mechanism 220 passes the powder supply slot 112 last. The printing mechanism 230 is used to selectively sinter the powder on the build platform 120. The printing mechanism 230 reciprocates along the X-axis. Specifically, the printing mechanism 230 includes an ejector head 231 and a flux lamp 232. The ejector head 231 is used to selectively eject flux onto the powder on the build platform 120. The flux lamp 232 is used to sinter the powder to which flux has been ejected. Each time the printing mechanism 230 moves, the ejector head 231 and the flux lamp 232 pass over the build platform 120. An image acquisition device 240 is fixed to the printer body 210 and is used to acquire images of the upper surfaces of the powder in the build slot 111 and the two powder supply slots 112. Therefore, the field of view of the image acquisition device 240 covers the upper surfaces of the build platform 120 and the two powder supply slots 112. The controller is signal-connected to the powder spreading mechanism 220, the printing mechanism 230, and the image acquisition device 240. When the build unit 100 is attached to the printer body 210, the build platform 120 and the two powder supply units 130 are also signal-connected to the controller. This signal connection can be an electrical connection or a wireless signal connection. The controller receives images acquired by the image acquisition device 240 and controls the movement of the powder spreading mechanism 220, the printing mechanism 230, the build platform 120, and the two powder supply units 130 to achieve layer-by-layer printing. Ultimately, the 3D printed part is formed layer by layer in the build space.
[0039] Referring to Figure 3, Figure 3 illustrates the specific method by which the controller controls the movement of each component during each layer of printing. As shown in Figure 3, each layer of printing sequentially includes a toner supply step S10, a laying step S20, an image acquisition step S30, and a printing step S40.
[0040] The toner supply step S10 includes the process of the build platform 120 descending by a first preset distance (S11) and the toner supply process. The toner supply process further includes the process of the toner supply component 130 on the toner supply side rising by a lifting distance (S12) and the process of the toner supply component 130 on the toner receiving side descending by a second preset distance (S13). In this embodiment, the controller controls the build platform 120 and the two toner supply components 130 to operate simultaneously, that is, processes S11, S12, and S13 are synchronized and parallel. In other embodiments, the controller can also control processes S11, S12, and S13 to operate sequentially, and the order is irrelevant. The first and second preset distances here refer to distances that have been manually set. That is, during each layer printing, the distance the build platform 120 descends is consistent, and the distance the toner supply component 130 on the toner receiving side descends is also consistent. In other embodiments, the distance the toner supply component 130 on the toner receiving side descends can vary. The specific calculation method for the lifting distance of the powder supply component 130 on the powder supply side is as follows: During the first layer printing, the lifting distance is the first distance. For each subsequent layer printing, the lifting distance is determined based on the diffusion distance obtained during the previous layer printing. If the diffusion distance is less than a threshold, the lifting distance is the first distance; if the diffusion distance is greater than the threshold, the lifting distance is the second distance; if the diffusion distance is equal to the threshold, the lifting distance is either the first distance or the second distance. Among them, the first distance is greater than the second distance. The diffusion distance is the distance that the powder received by the powder supply groove 112 on the powder supply side of the current layer printing (that is, the powder receiving groove 112 on the powder receiving side of the previous layer printing) diffuses along the laying direction during the previous layer printing after step S20 is completed. Specifically, the diffusion distance is the average value of the distance between the edge line formed by the powder received by the powder supply groove 112 on the powder supply side of the current layer printing and the groove edge of the powder supply groove 112 closest to the build platform 120 along the laying direction of the previous layer printing (when the edge line is curved). The specific method for obtaining the diffusion distance is as follows: after the image acquired by the image acquisition device 240 in step S30 of the previous layer printing is transmitted to the controller, the controller obtains the position of the edge line according to the image processing method and processes it according to the position of the edge line. The image processing method can be an edge processing algorithm. Further explanation is needed regarding the first and second distances. The first distance should be set to a product of itself and the horizontal cross-sectional area of the toner supply trough 112 cavity that is slightly greater than the product of the first set distance and the horizontal cross-sectional area of the build trough 111 cavity. The second distance should be set to a product of itself and the horizontal cross-sectional area of the toner supply trough 112 cavity that is slightly less than the product of the first set distance and the horizontal cross-sectional area of the build trough 111 cavity. The threshold here can preferably be set to half the dimension of the toner supply trough 112 cavity along the Y-axis. Of course, the threshold can also be set to one-third of the dimension of the toner supply trough 112 cavity along the Y-axis or other values.
[0041] In step S20, the controller controls the powder spreading mechanism 220 to move unidirectionally along the Y-axis to spread powder onto the build platform 120. The powder spreading roller passes over the powder overflow trough 113 on the powder supply side, the powder supply trough 112 on the powder supply side, the build platform 120, the powder supply trough 112 on the powder receiving side, and the powder overflow trough 113 on the powder receiving side during this printing process. After step S20, the powder lifted by the powder supply component 130 on the powder supply side is spread onto the build platform 120. Powder overflowing from the build platform 120 overflows into the powder supply trough 112 on the powder receiving side. If the powder supply trough 112 cannot accommodate all the overflowing powder, the overflowing powder will also overflow into the powder overflow trough 113 on the powder receiving side. However, the control method in this embodiment can minimize the amount of powder overflowing into the powder overflow trough 113, or even eliminate the amount of powder overflowing into the powder overflow trough 113, by adjusting the first distance, the second distance, and the threshold.
[0042] In step S30, the controller controls the image acquisition device 240 to capture images and send them to the controller.
[0043] In step S40, the controller controls the printing mechanism 230 to move along the X-axis to selectively sinter the powder laid on the build platform 120.
[0044] In this embodiment, by lowering the powder supply component 130 on the powder receiving side, at least a majority of the powder overflowing from the build platform 120 is received into the powder supply trough 130. Compared to the prior art where the powder overflowing from the build platform 120 is received into the overflow trough 120, at least a majority of the overflowing powder can be reused for laying onto the build platform 120. Therefore, the build unit 100 needs to carry less powder than in the prior art. It should be noted that the above effect can be achieved simply by lowering the powder supply component 130 on the powder receiving side. Therefore, the technical solution for achieving the above technical effect is not limited to the technical solution disclosed in this embodiment; this embodiment is only one preferred embodiment.
[0045] In this embodiment, the lifting distance of the powder supply component 130 on the powder supply side is determined by the amount of powder received by the corresponding powder supply trough 112 when the powder spreading mechanism 220 lays a layer of powder. Compared with the case where the lifting distance remains unchanged, the amount of powder overflowing from the build platform 120 and falling into the overflow trough 113 can be further reduced, thus further reducing the amount of powder that the build unit 100 needs to carry.
[0046] In this embodiment, under the premise that the descent distance of the powder supply component 130 on the receiving side is consistent, the amount of powder received by the powder supply trough 112 when the powder spreading mechanism 220 spreads a layer of powder is represented by the diffusion distance. Compared with other calculation methods, this can reduce the amount of calculation required to measure the amount of powder received. Furthermore, the lifting distance is limited to the first distance and the second distance, which can optimize the control logic for the lifting distance and avoid overly complex control logic.
[0047] In this embodiment, obtaining the diffusion distance from the image acquired by the image acquisition device 240 is a preferred implementation method for measuring diffusion distance. This is mainly based on the fact that the received powder can form a clear edge line on the surface of the powder in the powder supply tank 112.
[0048] In this embodiment, by setting up an overflow trough 113, excess powder can be received when the powder overflowing from the construction platform 120 cannot be fully received by the powder supply trough 112 on the powder receiving side, thus avoiding waste.
[0049] The description of the above specification and embodiments is used to explain the scope of protection of this application, but does not constitute a limitation on the scope of protection of this application.
Claims
1. A powder supply method for supplying powder for 3D printing to a powder spreading mechanism, so that the powder spreading mechanism spreads the powder onto a build platform along a spreading direction; the build platform is provided with powder supply slots and powder supply components on both sides along the spreading direction, the powder supply slots are used to hold powder, and the powder supply components are located in the corresponding powder supply slots and move up and down relative to the powder supply slots; characterized in that, Each time powder is supplied, the powder supply component on the powder supply side supplies powder by lifting, and the powder receiving component on the powder receiving side receives the powder overflowing from the construction platform by lowering; the powder supply side is the side of the powder supply trough that the powder spreading mechanism passes through first when spreading, and the powder receiving side is the side of the powder supply trough that the powder spreading mechanism passes through later when spreading.
2. The powder supply method as described in claim 1, characterized in that, Each time powder is supplied, the lifting distance of the powder supply component on the powder supply side is determined by the amount of powder received by the corresponding powder supply trough when the powder spreading mechanism lays a layer of powder.
3. The powder supply method as described in claim 2, characterized in that, Each time powder is supplied, the powder supply component on the receiving side descends the same distance.
4. The powder supply method as described in claim 3, characterized in that, The amount of powder received by the powder supply trough when the powder spreading mechanism spreads a layer of powder is characterized by the spread distance of the received powder along the spreading direction; if the spread distance is less than a threshold, the lifting distance is the first distance; if the spread distance is greater than the threshold, the lifting distance is the second distance; if the spread distance is equal to the threshold, the lifting distance is either the first distance or the second distance; the first distance is greater than the second distance.
5. The powder supply method as described in claim 4, characterized in that, The spread distance is the average distance between the edge line formed by the powder received by the powder supply trough when the powder spreading mechanism lays a layer of powder along the laying direction and the edge of the powder supply trough near the construction platform.
6. The powder supply method as described in claim 5, characterized in that, The diffusion distance is obtained by using an image acquisition device to capture an image of the upper surface of the powder in the powder supply trough after a layer of powder has been laid by the powder spreading mechanism.
7. The powder supply method as described in claim 6, characterized in that, The field of view of the image acquisition device covers the upper surfaces of the construction platform and the two powder supply tanks.
8. A three-dimensional printing method, which obtains a three-dimensional printed part by printing layer by layer; each layer of printing sequentially includes a powder supply step, a laying step, and a printing step; the powder supply step includes a construction platform descent process and a powder supply process, the laying step is used to lay powder onto the construction platform, and the printing step is used to selectively sinter the powder laid onto the construction platform; characterized in that... The powder supply process adopts the powder supply method as described in any one of claims 1 to 5.
9. A three-dimensional printing method, which obtains a three-dimensional printed part by printing layer by layer; characterized in that, Each layer of printing sequentially includes a powder supply step, a layup step, an image acquisition step, and a printing step; the powder supply step includes a build platform descent process and a powder supply process, the layup step is used to lay powder onto the build platform, the image acquisition step is used to acquire an image of the upper surface of the powder in the powder supply tank, and the printing step is used to selectively sinter the powder laid onto the build platform; wherein, the powder supply process adopts the powder supply method as described in any one of claims 4 to 7, and the diffusion distance is obtained from the image acquired during the printing of the previous layer.
10. A three-dimensional printing system, characterized in that, It includes building blocks and printers; The building unit includes a building body, a building platform, and two powder supply components; the building body is provided with a building slot and powder supply slots located on both sides of the building slot, the building platform is located in the building slot and moves up and down relative to the building body, and the powder supply components are located in the corresponding powder supply slots and move up and down relative to the building body. The printer includes a printer body, a toner spreading mechanism, an image acquisition device, and a controller; the printer body is adapted to be attached to the build unit, and the toner spreading mechanism reciprocates relative to the printer body along the spreading direction; when the build unit is attached to the printer body, the spreading direction is the same as the layout direction of the build slot and the toner supply slot; the image acquisition device is used to acquire images of the upper surface of the powder in the build slot and the two toner supply slots; the controller is signal-connected to the toner spreading mechanism, the image acquisition device, the build platform of the build unit attached to the printer body, and the two toner supply components. The controller receives images acquired by the image acquisition device and controls the movement of the powder spreading mechanism, the building platform, and the two powder supply components to achieve layer-by-layer printing. During each layer printing, the controller first controls the building platform to descend by a first preset distance, and controls the powder supply component on the powder supply side to rise by a lifting distance and controls the powder supply component on the powder receiving side to descend by a second preset distance. Then, the controller controls the powder spreading mechanism to sequentially pass through the powder supply slots on the powder supply side and the powder supply slots on the powder receiving side along the laying direction. After that, the controller controls the image acquisition device to acquire and receive images. The controller obtains the spread distance of the powder received in the powder supply slot on the receiving side along the laying direction based on the received images. When printing the first layer, the lifting distance is the first distance; when printing each subsequent layer, the lifting distance is determined based on the diffusion distance obtained when printing the previous layer. When the diffusion distance is less than a threshold, the lifting distance is the first distance; when the diffusion distance is greater than the threshold, the lifting distance is the second distance; when the diffusion distance is equal to the threshold, the lifting distance is either the first distance or the second distance; the first distance is greater than the second distance.
11. A three-dimensional printing system as described in claim 10, characterized in that, The printer also includes a printing mechanism for printing powder on the build platform, and the controller is also signal-connected to the printing mechanism; during each layer printing, the controller controls the printing mechanism to print after receiving the image; the build body is also provided with two powder overflow grooves, which are set with two powder supply grooves, and the powder supply grooves are located between the build platform and the corresponding powder overflow grooves along the laying direction.