3D printing forming method and device based on powder bed

Abstract

The invention discloses a 3D printing forming method and device based on a powder bed, and the method adopts partition printing forming, carries out normal platform lifting, region powder laying and printing forming on a region with a geometric contour, and does not carry out platform lifting, region powder laying and printing forming on a region without a geometric contour. And therefore, the utilization rate of the powder material can be greatly increased, pollution, recycling, screening and the like of invalid powder are reduced, and the 3D printing use cost is reduced.

Description

Technical Field

[0001] The present invention relates to the field of 3D printing technology, and more specifically to a 3D printing forming method and device based on a powder bed. Background Art

[0002] 3D printing technology, also known as additive manufacturing technology, is based on the principle of layered manufacturing and completes manufacturing through layer-by-layer processing and superimposed forming.

[0003] The current 3D printing technology can be divided into powder bed-based 3D forming technology, filament-based 3D printing forming technology, and plate-based 3D printing forming technology according to the type of materials used. Powder bed-based 3D printing forming technology is one of the current mainstream 3D printing technologies. This technology first slices the geometric model of the printed part in layers to obtain the printing contour data of each layer of the part. Then, the powder laying device is driven to lay the powder layer by layer in a specific forming box. After the powder is laid, the computer drives the laser or inkjet print head according to the contour data of each layer of the printed part to realize the printing of the powder. Then, the powder is laid and printed layer by layer to finally obtain the required parts. Compared with filament and plate-based 3D printing technologies, this technology has the advantages of high manufacturing efficiency and high forming accuracy.

[0004] However, the current powder bed-based 3D printing technology has problems such as low powder material utilization rate, low powder recovery and reuse rate, and high cost of using 3D printing technology, which is not conducive to the popularization and promotion of powder bed-based 3D printing technology.

[0005] Therefore, providing a 3D printing forming method and device based on a powder bed is an urgent problem to be solved by those skilled in the art.

[0006] invention

[0007] In view of this, the present invention provides a 3D printing forming method and device based on a powder bed to solve the problems of low powder material utilization rate, low powder recovery and reuse rate and high cost of using 3D printing technology.

[0008] In order to achieve the above object, the present invention adopts the following technical solution:

[0009] A 3D printing forming method based on a powder bed comprises the following steps:

[0010] 1) The computer slices the three-dimensional model of the printed part in layers along the height direction to obtain the contour information of each layer of the printed part, and calculates and outputs the processing path of the forming device based on the layered contour information;

[0011] 2) The computer calculates the opening height of each independent lifting platform based on the area size of the independent lifting platform in the forming box and the layered slicing information of the printed parts;

[0012] 3) The computer calculates the opening and closing time of each independently opened and closed powder spreading opening in the powder spreading device when laying each layer of powder according to the area size of the independent lifting platform in the forming box and the layered slicing information of the printed parts;

[0013] 4) The computer drives the vacuum feeding device to deliver the powder material stored in the storage box to the powder spreading device;

[0014] 5) The computer drives multiple independent lifting platforms in the forming box to rise to the top surface of the forming box;

[0015] 6) The computer drives multiple independent lifting platforms to descend a fixed layer thickness distance as needed based on the layered slicing information of the printed parts;

[0016] 7) A computer drives a powder spreading device with multiple independent opening and closing powder spreading openings to spread a layer of powder on multiple independent lifting platforms of the forming box as needed;

[0017] 8) The computer drives the laser or inkjet print head to print according to the processing path of each layer to achieve the printing and forming of the current layer of powder;

[0018] 9) Repeat steps 6) to 8), print layer by layer, and finally stack them layer by layer to complete the part printing.

[0019] By adopting the above technical solution, the beneficial effects of the present invention are:

[0020] By adopting zoned printing, normal platform lifting, regional powder spreading and printing are performed for areas with geometric contours, while platform lifting, regional powder spreading and printing are not performed for areas without geometric contours. This can greatly improve the utilization rate of powder materials, reduce the pollution, recycling and screening of invalid powder, and reduce the cost of 3D printing.

[0021] Furthermore, the length and width of the area size of the independent lifting platform can be divided by the length and width of the inner side of the forming box respectively.

[0022] Furthermore, the opening height of each independent lifting platform is calculated to obtain the minimum value of the three-dimensional model of the printed part in the height direction within each independent lifting platform area.

[0023] Furthermore, the area dimension width of the independent lifting platform is consistent with the dimension width of each independently opened and closed powder spreading opening in the powder spreading device.

[0024] Furthermore, after the part is printed, the excess unformed powder in the forming box is cleaned off and the part is taken out.

[0025] Furthermore, the powder is one or more of metal powder, ceramic powder and polymer powder.

[0026] A 3D printing forming device based on a powder bed, comprising a closed forming chamber, a forming box, a plurality of independent lifting platforms, an X-axis motion system, a powder spreading device, a printing element, a material storage box, a vacuum feeding system and a control system, wherein the forming box is installed inside the closed forming chamber; a plurality of the independent lifting platforms are all installed in the forming box; the X-axis motion system is installed in the closed forming chamber and is located above the forming box; the powder spreading device is installed on the X-axis motion system and corresponds to the positions of the plurality of independent lifting platforms; the printing element is installed at the top of the closed forming chamber; the material storage box is placed outside the closed forming chamber; the vacuum feeding system is installed at the top of the closed forming chamber and corresponds to the position of the powder spreading device, and the vacuum feeding system is connected and communicated with the material storage box; the control system is electrically connected to the powder spreading device, the X-axis motion system, the plurality of the independent lifting platforms, the printing element and the vacuum feeding system respectively.

[0027] Furthermore, the powder spreading device includes a hopper and a vibrating paver connected as one body, the hopper is mounted on the X-axis motion system; the hopper has a plurality of powder spreading openings separated from each other, each of the powder spreading openings is equipped with an electric opening and closing cover; the control system is electrically connected to the plurality of electric opening and closing covers respectively.

[0028] Furthermore, the printing element is a laser system or an inkjet print head, and the laser system includes a laser and a scanning galvanometer; the controller is electrically connected to the laser and the scanning galvanometer respectively, or the controller is electrically connected to the inkjet print head.

[0029] Furthermore, the X-axis motion system includes an X-axis movable guide rail, a slide and an X-axis movable motor, the X-axis movable guide rail is installed in the closed forming chamber and is located above the forming box; the slide is slidably connected to the X-axis movable guide rail; the X-axis movable motor is connected to the slide; and the control system is electrically connected to the X-axis movable motor.

[0030] It can be seen that the present invention provides a 3D printing forming method and device based on a powder bed. Compared with the prior art, the present invention has the following beneficial effects:

[0031] 1) The powder material utilization rate is high and the later cleaning is easy;

[0032] 2) There is less waste of invalid powder materials and low cost of use, which is more conducive to the popularization and promotion of powder bed-based 3D printing technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0034] Figure 1 The accompanying drawing is a cross-sectional view of a powder bed-based 3D printing forming device provided by the present invention;

[0035] Figure 2 The accompanying drawing is a cross-sectional view of a 3D printing forming device based on a powder bed provided by the present invention in a working state;

[0036] Figure 3 The accompanying drawing is a schematic structural diagram of a powder spreading device provided by the present invention;

[0037] Figure 4 The accompanying drawing is a schematic diagram of the structure of the printing parts provided by the present invention. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] like Figure 1-4 As shown, the present invention takes a special-shaped plate part as an example and discloses a 3D printing forming method based on a powder bed, comprising the following steps:

[0040] 1) The computer slices the three-dimensional model of the printed part 9 in layers along the height direction to obtain the contour information of each layer of the printed part 9, and calculates and outputs the processing path of the printing element 6 according to the layered contour information;

[0041] 2) The computer calculates the opening height of each independent lifting platform 3 according to the area size of the independent lifting platform 3 in the forming box 2 and the layered slicing information of the printed part 9; in this embodiment, the independent lifting platform 3 includes a plurality of first independent lifting platforms 31, a plurality of second independent lifting platforms 32, a plurality of third independent lifting platforms 33 and a plurality of fourth independent lifting platforms 34. The computer divides the layered slicing information of the printed part 9 into sub-area layered slicing information corresponding to the first independent lifting platform 31, the second independent lifting platform 32, the third independent lifting platform 33 and the fourth independent lifting platform 34 according to the area size of the first independent lifting platform 31, the second independent lifting platform 32, the third independent lifting platform 33 and the fourth independent lifting platform 34 in the forming box 2 and the layered slicing information of the printed part 9, calculates the minimum height value of the geometric contour points of the printed part 9 in each sub-area, and uses the minimum height value as the starting height of the first independent lifting platform 31, the second independent lifting platform 32, the third independent lifting platform 33 and the fourth independent lifting platform 34 to start the layer-by-layer descending movement during the printing process;

[0042] 3) The computer calculates the opening and closing time of each independently opened and closed powder spreading opening 511 in the powder spreading device 5 when laying each layer of powder according to the area size of the independent lifting platform 3 in the forming box 2 and the layered slicing information of the printed part 9; in this embodiment, the computer obtains the sub-areas corresponding to different powder spreading heights that have not yet started the platform descent according to the area size of the first independent lifting platform 31, the second independent lifting platform 32, the third independent lifting platform 33 and the fourth independent lifting platform 34 in the forming box 2 and the layered slicing information of the printed part 9, and closes the powder spreading openings of these sub-areas that have not yet started the platform descent when laying powder, thereby correspondingly calculating the opening and closing time of each independently opened and closed powder spreading opening 511 in the powder spreading device 5 when laying powder of different heights, and for the sub-areas that have already started the platform descent, the powder spreading opening 511 will be kept open during the powder spreading process until the current layer of powder spreading is completed;

[0043] 4) The computer drives the vacuum feeding device 8 to feed the powder material stored in the storage box 7 into the powder spreading device 5; in this embodiment, a powder material with a particle size of 500 / 1000 mesh is prepared and loaded into the storage box 7 as a raw material for 3D printing;

[0044] 5) The computer drives the multiple independent lifting platforms 3 in the forming box 2 to rise to the top surface of the forming box 2; in this embodiment, the computer drives the first independent lifting platform 31, the second independent lifting platform 32, the third independent lifting platform 33 and the fourth independent lifting platform 34 in the forming box 2 to rise to the top surface of the forming box 2;

[0045] 6) The computer drives the multiple independent lifting platforms 3 to descend a fixed layer thickness distance as required according to the layered slicing information of the printed part 9; in this embodiment, the computer drives the multiple second independent lifting platforms 32 and the third independent lifting platforms 33 to descend a fixed layer thickness distance of 0.1 mm as required according to the layered slicing information of the printed part 9;

[0046] 7) The computer drives the powder spreading device 5 having multiple independent opening and closing powder spreading openings 511 to spread a layer of powder on the multiple independent lifting platforms 3 of the forming box 2 as required; In this embodiment, the computer drives the powder spreading device 5 having multiple independent opening and closing powder spreading openings 511 to spread a layer of powder on the multiple second independent lifting platforms 52 and the third independent lifting platforms 53 of the forming box 2 as required;

[0047] 8) The computer drives the laser 61 or the inkjet print head to print according to the processing path of each layer to achieve the printing and forming of the current layer of powder;

[0048] 9) Repeat steps 6) to 8), print layer by layer, and finally stack them layer by layer to complete the part printing;

[0049] In this embodiment, when the first independent lifting platform 31 starts to descend, the current loop is jumped out and the next loop is entered: the computer drives the multiple first independent lifting platforms 31, the second independent lifting platform 32, and the third independent lifting platform 33 to descend by a fixed layer thickness of 0.1 mm as required according to the layered slicing information of the printed part 9, and the computer drives the powder spreading device 5 with multiple independent opening and closing powder spreading ports 511 to spread a layer of powder on the multiple first independent lifting platforms 31, the second independent lifting platform 32, and the third independent lifting platform 33 of the forming box 2 as required, and the computer drives the laser 61 or the inkjet print head to print according to the processing path of each layer, so as to realize the printing and forming of the current layer of powder;

[0050] Repeat the above steps, print layer by layer, and when the third independent lifting platform 33 starts to descend, jump out of the current loop and enter the next loop: the computer drives the first independent lifting platform 31, the second independent lifting platform 32, the third independent lifting platform 33 and the fourth independent lifting platform 34 to descend a fixed layer thickness of 0.1mm as required according to the layered slicing information of the printed part 9, and the computer drives the powder spreading device 5 with multiple independent opening and closing powder spreading ports 511 to spread a layer of powder on the multiple first independent lifting platforms 31, the second independent lifting platforms 32, the third independent lifting platforms 33 and the fourth independent lifting platforms 34 of the forming box 2 as required, and the computer drives the laser 61 or the inkjet print head to print according to the processing path of each layer, so as to realize the printing and forming of the current layer of powder;

[0051] Repeat the above steps, print layer by layer, and finally stack them layer by layer to complete the manufacture of printed parts.

[0052] The present invention performs normal platform lifting, regional powder spreading and printing forming on the area with geometric contours, and does not perform platform lifting, regional powder spreading and printing forming on the area without geometric contours, thereby greatly improving the utilization rate of powder materials, reducing the pollution, recycling and screening of invalid powder, and reducing the cost of 3D printing.

[0053] Specifically, the length and width of the area size of the independent lifting platform 3 can be divided by the length and width of the inner side of the forming box 2 respectively.

[0054] Specifically, the opening height of each independent lifting platform 3 is calculated to correspond to the minimum value of the three-dimensional model of the printed part 9 in the height direction within the area of ​​each independent lifting platform 3.

[0055] Specifically, the area size width of the independent lifting platform 3 is consistent with the size width of each independently opened and closed powder spreading opening 511 in the powder spreading device 5 .

[0056] Specifically, after the printing of the part is completed, the excess unformed powder in the forming box 2 is cleaned up and the part is taken out.

[0057] Specifically, the powder is one or more of metal powder, ceramic powder, and polymer powder.

[0058] The embodiment of the present invention further discloses a 3D printing forming device based on a powder bed, comprising a closed forming chamber 1, a forming box 2, a plurality of independent lifting platforms 3, an X-axis motion system 4, a powder spreading device 5, a printing element 6, a material storage box 7, a vacuum feeding system 8 and a control system. The closed forming chamber 1 is used to place the powder 3D printing process in a controllable environmental condition to ensure the quality of the final parts; the forming box 2 is installed inside the closed forming chamber 1 to provide a three-dimensional forming space for powder 3D printing; the plurality of independent lifting platforms 3 are all installed in the forming box 2 to support powder materials, and the independent lifting platforms 3 are rectangular platforms of the same or different sizes. In the present embodiment, the plurality of independent lifting platforms 3 include a plurality of first independent lifting platforms 31, a plurality of second independent lifting platforms 32, a plurality of third independent lifting platforms 33 and a plurality of fourth independent lifting platforms 34; the X-axis motion system 4 is installed in the closed forming chamber 1 and is located above the forming box 2, and is used to provide linear motion in the X-axis direction in the horizontal plane; the powder spreading device 5 is installed on the X-axis motion system 4 and corresponds to the position of multiple independent lifting platforms 3, and is used to spread powder on the independent lifting platforms 3 as needed; the printing element 6 is installed on the top of the closed forming chamber 1, and is used to realize powder printing and forming; the storage box 7 is placed outside the closed forming chamber 1; the vacuum feeding system 8 is installed on the top of the closed forming chamber 1 and corresponds to the position of the powder spreading device 5, and the vacuum feeding system 8 is connected to the storage box 7 to provide the powder required for printing; the control system is electrically connected to the powder spreading device 5, the X-axis motion system 4, the multiple independent lifting platforms 3, the printing element 6 and the vacuum feeding system 8, respectively, to realize the control of the printing process of the entire 3D printing forming device.

[0059] Specifically, the powder spreading device 5 includes a hopper 51 and a vibrating spreader 52 which are connected as one body, and the hopper 51 is installed on the X-axis motion system 4; the hopper 51 has a plurality of powder spreading openings 511 which are separated and distributed, and each powder spreading opening 511 is equipped with an electric opening and closing cover; the control system is electrically connected to the plurality of electric opening and closing covers respectively.

[0060] Specifically, the printing element 6 is a laser system or an inkjet print head. The inkjet print head is used to spray binder on demand. The laser system includes a laser 61 and a scanning galvanometer 62, which are used to sinter powder on demand. The controller is electrically connected to the laser 61 and the scanning galvanometer 62, respectively, or the controller is electrically connected to the inkjet print head.

[0061] Specifically, the X-axis motion system 4 includes an X-axis movable guide rail, a slide and an X-axis movable motor. The X-axis movable guide rail is installed in the closed forming chamber 1 and is located above the forming box 2; the slide is slidably connected to the X-axis movable guide rail; the X-axis movable motor is connected to the slide; the control system is electrically connected to the X-axis movable motor to control the slide to move along the X-axis movable guide rail.

[0062] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0063] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A 3D printing method based on a powder bed, characterized in that: The following steps are involved: 1) The computer slices the three-dimensional model of the printed part in layers along the height direction to obtain the contour information of each layer of the printed part, and calculates and outputs the processing path of the forming device based on the layered contour information; 2) The computer calculates the opening height of each independent lifting platform based on the area size of the independent lifting platform in the forming box and the layered slicing information of the printed parts; 3) The computer calculates the opening and closing time of each independently opened and closed powder spreading opening in the powder spreading device when laying each layer of powder according to the area size of the independent lifting platform in the forming box and the layered slicing information of the printed parts; 4) The computer drives the vacuum feeding device to deliver the powder material stored in the storage box to the powder spreading device; 5) The computer drives multiple independent lifting platforms in the forming box to rise to the top surface of the forming box; 6) The computer drives multiple independent lifting platforms to descend a fixed layer thickness distance as needed based on the layered slicing information of the printed parts; 7) A computer drives a powder spreading device with multiple independent opening and closing powder spreading openings to spread a layer of powder on multiple independent lifting platforms of the forming box as needed; 8) The computer drives the laser or inkjet print head to print according to the processing path of each layer to achieve the printing and forming of the current layer of powder; 9) Repeat steps 6) to 8), print layer by layer, and finally stack them layer by layer to complete the part printing.

2. A 3D printing method based on a powder bed according to claim 1, characterized in that: The length and width of the area size of the independent lifting platform can be divided by the length and width of the inner side of the forming box respectively.

3. A 3D printing method based on a powder bed according to claim 1, characterized in that: The opening height of each independent lifting platform is calculated to correspond to the minimum value of the three-dimensional model of the printed part in the height direction within each independent lifting platform area.

4. A 3D printing method based on a powder bed according to claim 1, characterized in that: The area dimension width of the independent lifting platform is consistent with the dimension width of each independently opened and closed powder spreading opening in the powder spreading device.

5. A 3D printing method based on a powder bed according to claim 1, characterized in that: After the part is printed, clean up the excess unformed powder in the build box and take out the part.

6. A 3D printing method based on a powder bed according to claim 1, characterized in that: The powder is one or more of metal powder, ceramic powder and polymer powder.

7. A 3D printing forming device based on a powder bed, characterized in that: It includes a closed forming chamber, a forming box, a plurality of independent lifting platforms, an X-axis motion system, a powder spreading device, a printing element, a material storage box, a vacuum feeding system and a control system, wherein the forming box is installed inside the closed forming chamber; the plurality of independent lifting platforms are all installed in the forming box; the X-axis motion system is installed in the closed forming chamber and is located above the forming box; the powder spreading device is installed on the X-axis motion system and corresponds to the positions of the plurality of independent lifting platforms; the printing element is installed at the top of the closed forming chamber; the material storage box is placed outside the closed forming chamber; the vacuum feeding system is installed at the top of the closed forming chamber and corresponds to the position of the powder spreading device, and the vacuum feeding system is connected to the material storage box; the control system is electrically connected to the powder spreading device, the X-axis motion system, the plurality of independent lifting platforms, the printing element and the vacuum feeding system respectively.

8. A 3D printing forming device based on a powder bed according to claim 7, characterized in that: The powder spreading device includes a hopper and a vibrating paver connected as one body, the hopper is installed on the X-axis motion system; the hopper has a plurality of powder spreading openings distributed in phase, each of the powder spreading openings is equipped with an electric opening and closing cover; the control system is electrically connected to the plurality of electric opening and closing covers respectively.

9. A 3D printing forming device based on a powder bed according to claim 7, characterized in that: The printing element is a laser system or an inkjet print head, and the laser system includes a laser and a scanning galvanometer; the controller is electrically connected to the laser and the scanning galvanometer respectively, or the controller is electrically connected to the inkjet print head.

10. The 3D printing forming device based on a powder bed according to claim 7, characterized in that: The X-axis motion system includes an X-axis movable guide rail, a slide and an X-axis movable motor. The X-axis movable guide rail is installed in the closed forming chamber and is located above the forming box; the slide is slidably connected to the X-axis movable guide rail; the X-axis movable motor is connected to the slide; and the control system is electrically connected to the X-axis movable motor.

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