A 3D printing method, device, equipment and storage medium

Abstract

The application discloses a 3D printing method, device, equipment and storage medium. The 3D printing method comprises the following steps: acquiring a required forming area difference of any two adjacent to-be-printed film layers in a to-be-printed part; determining a hollow scanning area of a latter to-be-printed film layer in the any two adjacent to-be-printed film layers according to the required forming area difference; the area of the hollow scanning area is greater than or equal to the required forming area difference; and laser scanning the hollow scanning area and a forming area of the latter to-be-printed film layer, and the scanning energy of the hollow scanning area is less than the scanning energy of the required forming area of the latter to-be-printed film layer. The above technical scheme increases the scanning time of the latter to-be-printed film layer by increasing the hollow scanning area, so that the latter to-be-printed film layer is sufficiently cooled, the input of the scanning energy of the forming area does not need to be reduced, the shrinkage lines caused by the large required forming area difference of different film layers of the to-be-machined part are eliminated, the surface quality of the to-be-machined part is improved, and the density is higher.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of additive manufacturing technology, and in particular to a 3D printing method, device, equipment and storage medium. BACKGROUND

[0002] The selective laser melting (SLM) forming technology can directly form complex structural parts without using a mold, and has strong technical advantages in the manufacturing field of complex structural parts.

[0003] Due to the complexity of the model and the layer-by-layer slicing and printing process of SLM from bottom to top, when there is a large reduction in the cross-sectional area in the 2D slice of the current layer and the next layer printed in the laser powder bed fusion (LPBF) technology, the model will have obvious "shrink marks", which will affect the appearance and surface quality of the part.

[0004] The existing technical solution to avoid shrink marks is to directly reduce the input of scanning energy to the forming area. However, reckless reduction of energy input will result in a decrease in the density of the part. SUMMARY

[0005] The present application provides a 3D printing method, device, equipment and storage medium, which can eliminate shrink marks caused by large differences in the required forming area of different film layers of the part to be processed without reducing the input of scanning energy to the forming area.

[0006] According to an aspect of the present application, a 3D printing method is provided, comprising:

[0007] Obtaining the difference in the required forming area of any two adjacent layers of the part to be printed;

[0008] Determining the empty scanning area of the next layer of the part to be printed according to at least the difference in the required forming area; the area of the empty scanning area is greater than or equal to the difference in the required forming area;

[0009] Scanning the empty scanning area and the forming area of the next layer of the part to be printed by laser, and the scanning energy of the empty scanning area is less than that of the forming area.

[0010] Optionally, determining the empty scanning area of the next layer of the part to be printed according to at least the difference in the required forming area, comprises:

[0011] Determining the area of the empty scanning area of the next layer of the part to be printed according to the difference in the required forming area;

[0012] The forming area of the later one of any two adjacent to-be-printed film layers is determined according to the forming area of the later one of the any two adjacent to-be-printed film layers, and the empty scanning area of the later one of the any two adjacent to-be-printed film layers is determined according to the forming area of the later one of the any two adjacent to-be-printed film layers.

[0013] Optionally, before determining the empty scanning area of the later one of any two adjacent to-be-printed film layers according to the demand forming area difference, the method further comprises:

[0014] The number M of film layers that need to have the empty scanning area is determined according to the demand forming area difference and the forming thickness of the later one of any two adjacent to-be-printed film layers.

[0015] The empty scanning area of the later one of any two adjacent to-be-printed film layers is determined according to at least the demand forming area difference, comprising:

[0016] In the i-th to-be-printed film layer to the i+M-th to-be-printed film layer, the empty scanning area of the later one of any two adjacent to-be-printed film layers is determined according to at least the demand forming area difference; wherein i is a positive integer, and M is a positive integer.

[0017] Optionally, the number M of film layers that need to have the empty scanning area is determined according to the demand forming area difference and the forming thickness of the later one of any two adjacent to-be-printed film layers, comprising:

[0018] The shrinkage line data corresponding to the demand forming area difference in the historical printing data is obtained.

[0019] The maximum length of the shrinkage line in a first direction is determined according to the shrinkage line data; wherein the first direction intersects with the extension direction of the shrinkage line.

[0020] The number M of film layers that need to have the empty scanning area is determined according to the ratio of the maximum length to the forming thickness of the later one of any two adjacent to-be-printed film layers.

[0021] Optionally, the j-th to-be-printed film layer comprises a plurality of to-be-printed rows, and at least part of the to-be-printed rows comprise empty scanning rows and forming rows; the empty scanning area comprises a plurality of the empty scanning rows, and the forming area comprises a plurality of the forming rows.

[0022] The empty scanning area and the forming area of the later one of the to-be-printed film layers are scanned by laser, comprising:

[0023] The empty scanning area and the forming area of the later one of the to-be-printed film layers are scanned by laser in the same scanning direction of the same to-be-printed row, and the scanning directions of any two adjacent to-be-printed rows are opposite.

[0024] Optionally, the laser scans the empty scanning area and the forming area of the subsequent printing film layer in the same scanning direction of the same printing row, in any of the following manners: the scanning directions of any two adjacent printing rows are opposite to each other, and the scanning directions of the printing rows of the two adjacent printing film layers intersect with each other.

[0025] The laser scans the empty scanning area and the forming area of the subsequent printing film layer in the same scanning direction of the same printing row, in any of the following manners: the scanning directions of any two adjacent printing rows are opposite to each other, and the scanning directions of the printing rows of the two adjacent printing film layers intersect with each other.

[0026] Optionally, the method further comprises: obtaining a required forming area difference between any two adjacent printing film layers in the part to be printed.

[0027] The method further comprises: obtaining a required forming area of each printing film layer in the part to be printed.

[0028] The method further comprises: calculating the required forming area difference between the two adjacent printing film layers according to the required forming area of each printing film layer.

[0029] According to another aspect of the present application, a 3D printing device is provided, comprising:

[0030] An area difference obtaining module is configured to obtain a required forming area difference between any two adjacent printing film layers in the part to be printed.

[0031] An empty scanning area determining module is configured to determine an empty scanning area of a subsequent printing film layer among any two adjacent printing film layers according to at least the required forming area difference; the area of the empty scanning area is greater than or equal to the required forming area difference.

[0032] A laser scanning module is configured to scan the empty scanning area and the forming area of the subsequent printing film layer by using a laser; the scanning energy of the empty scanning area is less than that of the forming area.

[0033] According to another aspect of the present application, a 3D printing device is provided, comprising:

[0034] at least one processor; and

[0035] a memory connected to the at least one processor in communication; wherein,

[0036] The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor to enable the at least one processor to execute the 3D printing method according to any one of the embodiments of the present application.

[0037] According to another aspect of the present application, there is provided a computer readable storage medium storing computer instructions for causing a processor to implement the 3D printing method according to any of the embodiments of the present application when executed.

[0038] The technical scheme of the embodiment of the present application increases the empty scanning area in the subsequent layer of the to-be-printed film layer when the difference between the required forming areas of any two adjacent layers of the to-be-printed film layer is large, and makes the scanning energy output by the laser to the empty scanning area smaller than the scanning energy output to the forming area when the laser scans the subsequent layer of the to-be-printed film layer, so as to increase the scanning time of the subsequent layer of the to-be-printed film layer and make it have more time to cool down, thereby avoiding the expansion caused by heat accumulation to cause shrinkage lines, and thus affecting the appearance and surface quality of the to-be-printed part. In addition, the above technical scheme does not need to change the scanning energy input to the forming area, and compared with the existing technical scheme of directly reducing the scanning energy input to the forming area, the density is higher.

[0039] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present application, nor is it used to limit the scope of the present application. Other features of the present application will become apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0041] Figure 1 is a schematic diagram of a printed part in the related art;

[0042] Figure 2 is a flowchart of a first 3D printing method according to an embodiment of the present application;

[0043] Figure 3 is a structural schematic diagram of a to-be-printed film layer according to an embodiment of the present application;

[0044] Figure 4 is a structural schematic diagram of another to-be-printed film layer according to an embodiment of the present application;

[0045] Figure 5 is a flowchart of a second 3D printing method according to an embodiment of the present application;

[0046] Figure 6 is a flowchart of a third 3D printing method according to an embodiment of the present application;

[0047] Figure 7 is a flow chart of a fourth 3D printing method according to an embodiment of the present application;

[0048] Figure 8 is a schematic diagram of a plurality of rows of to-be-printed lines on a to-be-printed film layer according to an embodiment of the present application;

[0049] Figure 9 is a schematic diagram of a plurality of rows of to-be-printed lines on a to-be-printed film layer according to another embodiment of the present application;

[0050] Figure 10 is a flow chart of a fifth 3D printing method according to an embodiment of the present application;

[0051] Figure 11 is a structural schematic diagram of a 3D printing device according to an embodiment of the present application;

[0052] Figure 12 is a structural schematic diagram of a 3D printing device for implementing a 3D printing method according to an embodiment of the present application. DETAILED DESCRIPTION

[0053] In order to enable persons skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by persons skilled in the art without creative efforts shall fall within the protection scope of the present application.

[0054] It should be noted that the terms "first", "second", and the like in the description and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device that includes a series of steps or units does not necessarily have to include only those steps or units clearly listed, but can include other steps or units that are not clearly listed or inherent to the process, method, product or device.

[0055] Before the reasons for the shrinkage lines are described in detail, the reasons for the shrinkage lines will be described first. Figure 1It is a printing part schematic diagram in the related art. Selective laser melting (SLM) forming technology can directly form a complex structure part without using a mold. Due to the complexity of the part to be printed, and the SLM is from bottom to top, layer by layer, when there is a large reduction in the cross-sectional area of the 2D slice of the current layer and the next layer, the scanning time is longer and the accumulated energy input is larger because the scanning area of the previous layer is large, and the scanning time is shorter and the accumulated energy input is smaller because the scanning area of the next layer is small. Among them, the scanning time of the next layer is shorter, which leads to less cooling time of the next layer, and the next layer expands due to the accumulation of heat, so that there is an obvious "shrinkage line L" on the printed part. The existence of the "shrinkage line L" will seriously affect the printing quality of the 3D printed product. Based on this, the embodiment of the present application provides a 3D printing method to eliminate or weaken the "shrinkage line L" generated in the 3D printing process, and improve the printing quality of the 3D printed product.

[0056] Figure 2 It is a flowchart of the first 3D printing method according to the embodiment of the present application; Figure 3 It is a structure schematic diagram of a to-be-printed film layer according to the embodiment of the present application; Figure 4 It is a structure schematic diagram of another to-be-printed film layer according to the embodiment of the present application. The embodiment can be applied to the case that the sudden change of the required forming area of the to-be-printed film layer in the to-be-printed part leads to part defects, and the method can be executed by a 3D printing device. As shown in Figure 2 The method comprises the following steps:

[0057] S110, obtaining the difference between the required forming areas of any two adjacent to-be-printed film layers in the to-be-printed part.

[0058] Specifically, the plurality of to-be-printed film layers exist in the to-be-printed part, the to-be-printed film layer is also a 2D slice, and the cross-sectional area of the 2D slice is the required forming area of the to-be-printed film layer. Further, the required forming area difference of the printing film layer is calculated according to the required forming areas of the adjacent two to-be-printed film layers. When the required forming area of the previous to-be-printed film layer is greater than the required forming area of the next to-be-printed layer, and the required forming area difference of the previous to-be-printed film layer and the next to-be-printed layer is greater than a preset value, the scanning area of the previous to-be-printed film layer is larger, so the scanning time and the accumulated energy input of the previous to-be-printed film layer are larger, while the scanning area of the next to-be-printed layer is reduced, and the scanning time and the accumulated energy input of the next to-be-printed layer are also reduced. Due to the reduction of the scanning time, the cooling time of the next to-be-printed film layer is less, and the heat accumulation of the next to-be-printed film layer leads to expansion, so that the to-be-printed part has obvious shrinkage lines at the height of the film layer, which affects the appearance and surface quality of the part. Therefore, by obtaining the required forming area difference of the adjacent two to-be-printed film layers, the required forming area difference can be compared with the preset value, and when the required forming area difference is greater than the preset value, it is judged that the to-be-printed part will have shrinkage lines.

[0059] It should be noted that the reason why the heat accumulation of the next to-be-printed film layer leads to expansion is that the required forming area of the next to-be-printed film layer is reduced, and in the case that the thickness of the to-be-printed film layer is unchanged, the volume of the next to-be-printed film layer is smaller. The structure with small volume has low heat conduction efficiency, and the scanning time is short and there is not enough time to complete cooling, which leads to higher temperature of the to-be-printed part and thermal expansion and contraction.

[0060] S120, determining the empty scanning area of the next to-be-printed film layer in any adjacent two to-be-printed film layers according to at least the required forming area difference.

[0061] The area of the empty scanning area is greater than or equal to the required forming area difference.

[0062] Specifically, as shown in FIG. 1, the blue area is the forming area 1 of the Nth to-be-printed film layer, and the green area is the forming area 2 of the Nth to-be-printed film layer. Figure 3 Figure 4 ​As shown, the blue area is the forming area 2 of the N+1 layer of the to-be-printed film layer, and the black area is the empty scanning area 3 of the N+1 layer of the to-be-printed film layer. The forming area 2 is the actual printing area of the to-be-printed part. The empty scanning area 3 refers to an area in which the galvanometer actually moves to control the scanning laser to scan, but no laser is output. In order to ensure sufficient cooling of the subsequent to-be-printed film layer, the area of the empty scanning area 3 can be greater than or equal to the required forming area difference, that is, the sum of the area of the empty scanning area and the forming area in the subsequent film layer is not less than the area of the forming area of the previous film layer. It can be understood that the greater the area of the empty scanning area 3, the longer the subsequent scanning time, and the longer the cooling time of the to-be-processed part, and therefore the area of the empty scanning area 3 can be greater than or equal to the required forming area difference.

[0063] S130, scanning the empty scanning area and the forming area of the subsequent to-be-printed film layer by using the laser.

[0064] The scanning energy of the empty scanning area is less than the scanning energy of the required forming area of the subsequent to-be-printed film layer.

[0065] It can be understood that, in order to prevent shrinkage lines, the embodiment increases the empty scanning area 3 in the N+1 layer. In this way, the scanning time of the N+1 layer of the to-be-printed film layer can be increased, so that the to-be-printed film layer has more time to cool. For example, when the empty scanning area and the forming area of the N+1 layer of the to-be-printed film layer are scanned by using the laser, the laser energy output in the empty scanning area is less than the laser energy output in the forming area. In this way, while ensuring that the scanning time of the N+1 layer of the to-be-printed film layer is increased, the normal scanning of the forming area of the N+1 layer is not affected.

[0066] Further, the laser energy output in the empty scanning area can be zero, that is, the laser does not output laser when scanning in the empty scanning area. In this way, on the one hand, the light output power of the laser can be saved, and the power consumption of the laser can be reduced. On the other hand, it can also be ensured that the forming area of the previous film layer is not damaged when the scanning area is scanned, and the normal forming of the 3D printing product is ensured.

[0067] Further, when the forming area of the subsequent film layer is scanned by using the laser, the laser scanning power thereof can be the same as or similar to the laser scanning power of the forming area of the previous film layer. In this way, the compactness of the forming areas in different film layers can be the same or similar, and the overall printing effect of the 3D printing product is good.

[0068] The embodiment of the present application is characterized in that when the difference between the required forming areas of any two adjacent to-be-printed film layers is large, an empty scanning area is added to the latter to-be-printed film layer, and the scanning energy input by the laser to the empty scanning area is less than that to the forming area when the laser scans the latter to-be-printed film layer, so as to increase the scanning time of the latter to-be-printed film layer and make it have more time to cool down, thereby avoiding the expansion caused by heat accumulation and the shrinkage lines, and further affecting the appearance and surface quality of the to-be-printed part. In addition, the above technical solution does not need to change the scanning energy input to the forming area, and compared with the existing technical solution of directly reducing the scanning energy input to the forming area, the density is good.

[0069] On the basis of the above-mentioned embodiment, the embodiment of the present application is a further refinement of the determination of the empty scanning area of the latter to-be-printed film layer in any two adjacent to-be-printed film layers according to the difference between the required forming areas, Figure 5 is a flow chart of a second 3D printing method according to the embodiment of the present application. As shown in Figure 5 , the method comprises the following steps:

[0070] S210, obtaining the difference between the required forming areas of any two adjacent to-be-printed film layers in a to-be-printed part.

[0071] S220, determining the area of the empty scanning area of the latter to-be-printed film layer in any two adjacent to-be-printed film layers according to the difference between the required forming areas.

[0072] As shown in Figure 3 and Figure 4 , the area difference between the forming area 1 of the Nth to-be-printed film layer and the forming area 2 of the (N+1)th to-be-printed film layer can be the area of the empty scanning area 3 of the (N+1)th to-be-printed film layer. It can be understood that the larger the area of the empty scanning area 3, the longer the subsequent scanning time, and the longer the cooling time of the to-be-processed part, so the area of the empty scanning area 3 can also be set to be greater than the difference between the required forming areas.

[0073] S230, determining the empty scanning area of the latter to-be-printed film layer in any two adjacent to-be-printed film layers according to the forming area of the latter to-be-printed film layer.

[0074] The empty scanning area surrounds the forming area.

[0075] Specifically, as shown in Figure 4 , since the projection of the forming area 2 of the (N+1)th to-be-printed film layer on the forming area 1 of the Nth to-be-printed film layer is not overlapped with the forming area 1 of the Nth to-be-printed film layer, the empty scanning area 3 is formed, so the empty scanning area 3 can surround the forming area 2 of the (N+1)th to-be-printed film layer.

[0076] Specifically, the empty scanning area of the subsequent film layer is arranged around the forming area, that is, the forming area can be located in the central area of the subsequent film layer, and the empty scanning area is symmetrically or approximately symmetrically distributed around the forming area. In this way, it can be ensured that the forming area can obtain sufficient cooling time during printing, and heat concentration caused by the concentration of the forming area can be avoided, so that heat dissipation is difficult.

[0077] S240, scanning the empty scanning area and the forming area of the subsequent film layer to be printed by laser.

[0078] The embodiment of the present application sets the non-overlapping part of the projection of the forming area of the subsequent film layer to be printed on the forming area of the previous film layer to be printed as the empty scanning area, so that the empty scanning area surrounds the forming area. The advantage of this arrangement is that the empty scanning area has better symmetry, which further improves the printing quality.

[0079] On the basis of the above-mentioned embodiments, the embodiment of the present application additionally adds a step of determining the number M of film layers with empty scanning areas according to the required forming area difference between any two adjacent film layers to be printed, and further refines the step, Figure 6 is a flow chart of a third 3D printing method provided by the embodiment of the present application. As shown in the figure, Figure 6 the method comprises the following steps:

[0080] S310, obtaining the required forming area difference between any two adjacent film layers to be printed in the part to be printed.

[0081] S320, determining the number M of film layers with empty scanning areas according to the required forming area difference and the forming thickness of the subsequent film layer to be printed in any two adjacent film layers to be printed.

[0082] For example, as shown in the figures, Figure 3 and Figure 4 When the area difference between the forming area 1 of the Nth film layer to be printed and the forming area 2 of the N+1th film layer to be printed is large, a large shrinkage mark will appear, which is specifically manifested as the film layers to be printed after the N+1th layer of the part to be printed will be larger than the original model and will return to normal after printing a preset number of film layers. Therefore, in order to eliminate the shrinkage mark, the empty scanning area needs to be increased in the preset number of film layers after the N+1th layer. The number M of film layers with empty scanning areas can be determined according to the area difference between the forming area 1 of the Nth film layer to be printed and the forming area 2 of the N+1th film layer to be printed, and the thickness of the N+1th film layer to be printed.

[0083] Specifically, determining the number M of film layers with empty scanning areas according to the required forming area difference and the forming thickness of the subsequent film layer to be printed in any two adjacent film layers to be printed can include:

[0084] obtaining shrinkage line data corresponding to the difference between the required forming area and the forming area from the historical printing data;

[0085] determining a maximum length of the shrinkage line in a first direction according to the shrinkage line data, wherein the first direction intersects with the extension direction of the shrinkage line;

[0086] determining the number M of the film layers required to have the empty scanning area according to the ratio of the maximum length to the forming thickness of the later film layer in the two adjacent film layers.

[0087] Specifically, the shrinkage line data refers to the width of the shrinkage line, which is determined by the difference between the required forming area and the forming area. The greater the difference, the wider the shrinkage line, and the poorer the surface quality of the printed part. Further, the maximum length in the first direction is the maximum width of the shrinkage line. Since the width of the shrinkage line is uneven, that is, the length of the shrinkage line in the first direction is long or short, the maximum length in the first direction is required to completely eliminate the shrinkage line. For example, when the width of the shrinkage line is 0.5 mm and the forming thickness of the later film layer is 0.05 mm, the ratio of the width of the shrinkage line to the forming thickness of the later film layer is 10, and therefore the number M of the film layers required to have the empty scanning area is 10.

[0088] In addition, in the present embodiment, the forming thicknesses of different film layers can be set to be the same. The advantage of this setting is that the forming thicknesses of different film layers are the same, and therefore the input scanning energy of the forming area in different film layers can be consistent. During the printing process of the printed part, the energy input to the forming area does not need to be changed, thereby improving the density of the printed part.

[0089] S330, in the i-th film layer to the i+M-th film layer, at least according to the difference between the forming areas to determine the empty scanning area of the later film layer in the two adjacent film layers.

[0090] wherein i is a positive integer, and M is a positive integer.

[0091] In the present embodiment, i is equal to 10 and M is equal to 10. In the 10th film layer to the 20th film layer, the empty scanning area of the 11th film layer can be determined according to the difference between the forming areas of the 10th and 11th layers, the empty scanning area of the 12th film layer can be determined according to the difference between the forming areas of the 11th and 12th layers, and so on. That is, when the difference between the forming areas of the 10th and 11th layers is equal to or greater than the preset value, the 11th to 20th layers all need to have the empty scanning area.

[0092] Further, if the difference between the forming areas of the 15th layer and the 16th layer is equal to or greater than the preset value in the printing process, i is equal to 15, and taking M equal to 10 as an example, the empty scanning area of the 16th layer to be printed is determined according to the difference between the forming areas of the 15th layer and the 16th layer, the empty scanning area of the 17th layer to be printed is determined according to the difference between the forming areas of the 16th layer and the 17th layer, and so on until the empty scanning area of the 25th layer is determined. That is, in the printing process, the printing from the 10th layer to the 20th layer has not been completed, and the difference between the areas of any two adjacent layers to be printed is equal to or greater than the preset value. At this time, the number of layers M is determined again according to the layer before any two adjacent layers to be printed, and the empty scanning area is generated in the corresponding layer.

[0093] It should be noted that the number of layers M with the empty scanning area is determined by the required forming area difference, and the greater the required forming area difference, the greater the number of layers M with the empty scanning area. Assuming that the required forming area difference is equal to the preset value, the number of layers M with the empty scanning area is equal to 10, so when the required forming area difference is greater than the preset value, the number of layers M with the empty scanning area is greater than 10.

[0094] In addition, if the difference between the forming areas of the 97th layer and the 98th layer is equal to or greater than the preset value in the printing process, i is equal to 97, and taking M equal to 10 as an example, the empty scanning area is generated in the 98th layer to the 107th layer, but since the part to be printed only needs to be printed for 100 layers, the empty scanning area is only generated in the 98th layer, the 99th layer and the 100th layer. That is, the part to be printed is printed and completed, and there is no need to print more layers.

[0095] S340, scanning the empty scanning area and the forming area of the next layer to be printed by laser.

[0096] In the embodiment of the present application, the number of layers with the empty scanning area is determined first before the empty scanning area is determined, and then the empty scanning area is determined in the corresponding layer, and then the empty scanning area and the forming area of the corresponding layer are scanned by laser. The number of layers is determined according to the maximum length of the shrinkage line in the first direction and the forming thickness of the next layer to be printed, so that the number of layers determined is more accurate, so as to completely eliminate the shrinkage line.

[0097] On the basis of the above-mentioned embodiments, the embodiment of the present application is based on that the jth to-be-printed film layer comprises a plurality of to-be-printed rows, and at least part of the to-be-printed rows comprise empty scanning rows and forming rows. In the case that the empty scanning area comprises a plurality of empty scanning rows and the forming area comprises a plurality of forming rows, the laser scanning of the empty scanning area and the forming area of the subsequent to-be-printed film layer is further described.

[0098] Figure 7 is a flow chart of a fourth 3D printing method according to an embodiment of the present application; Figure 8 is a schematic diagram of a plurality of to-be-printed rows on a to-be-printed film layer according to an embodiment of the present application; Figure 9 is a schematic diagram of a plurality of to-be-printed rows on a to-be-printed film layer according to another embodiment of the present application. The 3D printing method comprises the following steps:

[0099] S410, obtaining a required forming area difference of any two adjacent to-be-printed film layers in a to-be-printed part.

[0100] S420, determining an empty scanning area of a subsequent to-be-printed film layer in any two adjacent to-be-printed film layers according to at least the required forming area difference.

[0101] S430, scanning the empty scanning area and the forming area of the subsequent to-be-printed film layer in the same scanning direction of the same to-be-printed row and in the opposite scanning direction of any two adjacent to-be-printed rows.

[0102] For example, as shown in Figure 8 , the to-be-printed film layer comprises a plurality of to-be-printed rows a, wherein the scanning directions of the first to-be-printed row a1 are the same, the scanning directions of the second to-be-printed row a2 are the same, and the scanning directions of the first to-be-printed row a1 and the second to-be-printed row a2 are opposite.

[0103] In addition, the to-be-printed rows a in the empty scanning area are empty scanning rows, and the to-be-printed rows a in the forming area are to-be-printed rows. It should be noted that the laser is not output when scanning the empty scanning rows, and the laser is only output when scanning the to-be-printed rows.

[0104] The embodiment of the present application scans the empty scanning rows and the to-be-printed rows in the same scanning direction when printing the same scanning to-be-printed row, without changing the direction of the scanning laser and only adjusting the power of the scanning laser, which is beneficial to improve the scanning efficiency.

[0105] Optionally, Figure 9 is a schematic diagram of a plurality of to-be-printed rows on a to-be-printed film layer according to another embodiment of the present application; on the basis of the above-mentioned embodiments, the laser scanning of the empty scanning area and the forming area of the subsequent to-be-printed film layer is in the same scanning direction of the same to-be-printed row and in the opposite scanning direction of any two adjacent to-be-printed rows, which comprises:

[0106] The laser scans the empty scanning area and the forming area of the next layer of the to-be-printed film layer in the same manner as the scanning direction of the same to-be-printed row, in the manner that the scanning directions of any two adjacent to-be-printed rows are opposite, and the scanning directions of the to-be-printed rows in the adjacent two layers of the to-be-printed film layer intersect.

[0107] Specifically, as shown in Figure 8 and Figure 9 , the laser scanning direction of the jth layer is X, and the laser scanning direction of the j+1th layer is Y. After the jth layer of the to-be-printed film layer is printed, the laser scanning direction is rotated counterclockwise by a preset angle. The preset angle can be 67°, which is only for illustration and is not limited. In this way, the scanning directions of the to-be-printed rows in the adjacent two layers of the to-be-printed film layer intersect. The advantage of this setting is that it avoids the scanning laser in the same scanning direction in each layer of the to-be-printed film layer, so that the energy accumulated on the same printed row of the to-be-printed film layer is too high, which damages the to-be-printed part, and further improves the quality of the to-be-printed part.

[0108] On the basis of the above-mentioned embodiments, the present embodiment further describes how to obtain the difference in the required forming area of any two adjacent layers of the to-be-printed film layer in the to-be-printed part. Figure 10 is a flow chart of a fifth 3D printing method according to the present embodiment. As shown in Figure 10 , the method comprises the following steps:

[0109] S510, obtaining the required forming area of each layer of the to-be-printed film layer in the to-be-printed part.

[0110] For example, if the to-be-printed film layer is 100 layers, the required forming area of the 1st to 100th layer of the to-be-printed film layer needs to be obtained. The required forming area is obtained by a previous model processing software (VoxelDance Additive).

[0111] S520, calculating the difference in the required forming area of the adjacent two layers of the to-be-printed film layer according to the required forming area of each layer of the to-be-printed film layer.

[0112] Specifically, the appearance of the shrinkage line is due to the fact that the required forming area of the next layer of the to-be-printed film layer is too much smaller than that of the previous layer of the to-be-printed film layer. Therefore, the difference in the required forming area can be obtained by subtracting the required forming area of the previous layer of the to-be-printed film layer from the required forming area of the next layer of the to-be-printed film layer, so as to determine whether the subsequent printing process will cause the shrinkage line.

[0113] S530, determining the empty scanning area of the next layer of the to-be-printed film layer in any two adjacent layers of the to-be-printed film layer according to at least the difference in the required forming area.

[0114] S540, scanning the empty scanning area and the forming area of the next layer of the to-be-printed film layer by laser.

[0115] The embodiment of the present application obtains the required forming area of each to-be-printed film layer in the to-be-printed part, and calculates the required forming area difference between two adjacent to-be-printed film layers according to the required forming area of each to-be-printed film layer, so as to subsequently compare the required forming area difference with a preset value to determine whether the subsequent printing process will cause shrinkage lines, thereby effectively controlling the surface quality of the to-be-printed part.

[0116] Based on the same inventive concept, Figure 11 is a structural schematic diagram of a 3D printing device provided by an embodiment of the present application. As shown in the figure, Figure 11 The device comprises:

[0117] The area difference obtaining module 610 is configured to obtain the required forming area difference between any two adjacent to-be-printed film layers in the to-be-printed part.

[0118] The empty scanning area determining module 620 is configured to determine the empty scanning area of the latter to-be-printed film layer among any two adjacent to-be-printed film layers according to the required forming area difference, and the area of the empty scanning area is greater than or equal to the required forming area difference.

[0119] The laser scanning module 630 is configured to scan the empty scanning area and the forming area of the latter to-be-printed film layer by using a laser, and the scanning energy of the empty scanning area is less than the scanning energy of the required forming area of the latter to-be-printed film layer.

[0120] The 3D printing device provided by the embodiment of the present application can execute the 3D printing method provided by any embodiment of the present application, and has the corresponding function modules and beneficial effects of the execution method.

[0121] Based on the same inventive concept, Figure 12 A structural schematic diagram of a 3D printing device 10 that can be used to implement embodiments of the present application is shown. The 3D printing device is intended to represent various forms of digital computers, such as laptops, desktops, tablets, personal digital assistants, servers, blade servers, mainframes, and other appropriate computers. The 3D printing device can also represent various forms of mobile devices, such as personal digital assistants, cellular telephones, smart phones, wearable devices (e.g., headsets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions, are meant to be examples only, and are not intended to limit the implementations of the applications described and / or claimed in this document.

[0122] As Figure 12As shown, the 3D printing device 10 includes at least one processor 11, and a memory, such as a read-only memory (ROM) 12, a random access memory (RAM) 13, etc., communicatively connected to the at least one processor 11, where the memory stores a computer program executable by the at least one processor. The processor 11 can perform various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 12 or loaded from the storage unit 18 into the random access memory (RAM) 13. In the RAM 13, various programs and data required for the operation of the 3D printing device 10 can also be stored. The processor 11, the ROM 12, and the RAM 13 are connected to each other through a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0123] Various components in the 3D printing device 10 are connected to the I / O interface 15, including an input unit 16, such as a keyboard, a mouse, etc., an output unit 17, such as various types of displays, speakers, etc., a storage unit 18, such as a magnetic disk, an optical disk, etc., and a communication unit 19, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 19 allows the 3D printing device 10 to exchange information / data with other devices through a computer network, such as the Internet, and / or various telecommunication networks.

[0124] The processor 11 can be various general and / or special purpose processing components with processing and computing capabilities. Some examples of the processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any appropriate processor, controller, microcontroller, etc. The processor 11 performs various methods and processes described above, such as the 3D printing method.

[0125] In some embodiments, the 3D printing method can be implemented as a computer program tangibly embodied in a computer readable storage medium, such as the storage unit 18. In some embodiments, part or all of the computer program can be loaded and / or installed onto the 3D printing device 10 via the ROM 12 and / or the communication unit 19. When the computer program is loaded into the RAM 13 and executed by the processor 11, one or more steps of the 3D printing method described above can be performed. Alternatively, in other embodiments, the processor 11 can be configured to perform the 3D printing method by any other appropriate means, such as by means of firmware.

[0126] The various embodiments of the systems and techniques described above can be implemented in digital electronic circuitry, integrated circuitry, a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), a system on a chip (SOC), a load programmable logic device (CPLD), computer hardware, firmware, software, and / or combinations thereof. These various embodiments can include implementation in one or more computer programs that are executable and / or interpretable on a programmable system including at least one programmable processor, which can be special or general purpose, coupled to receive data and instructions from, and to transmit data and instructions to, a storage system, at least one input device, and at least one output device.

[0127] Computer programs used to implement the processes of the application can be written in any combination of one or more programming languages. These computer programs can be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the computer program, when executed, can cause instructions defined in the flow charts and / or block diagrams to be implemented. The computer program can be executed entirely on a machine, partially on a machine, partially on a machine as a standalone software package and partially on a remote machine or entirely on a remote machine or server.

[0128] In the context of the present application, a computer-readable storage medium can be a tangible medium that can contain or store computer programs for use by or in connection with an instruction execution system, apparatus, or device. Computer-readable storage media can include, but are not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium can be a machine-readable signal medium. More specific examples of the machine-readable storage medium will include one or more lines of electrical connections, portable computer disks, hard disk drives, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or Flash memory), optical fibers, portable compact disc read-only memories (CD-ROMs), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0129] To provide for interaction with a user, the systems and techniques described here can be implemented on a 3D printing device having a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user and a keyboard and a pointing device (e.g., a mouse or a trackball) by which the user can provide input to the 3D printing device. Other kinds of devices can be used to provide for interaction with a user as well; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form, including acoustic, speech, or tactile input.

[0130] The systems and techniques described here can be implemented in a computing system that includes a back end component (e.g., as a data server), or that includes a middleware component (e.g., an application server), or that includes a front end component (e.g., a user computer having a graphical user interface or a Web browser through which a user can interact with an implementation of the systems and techniques described here), or any combination of such back end, middleware, or front end components. The components of the system can be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0131] The computing system can include clients and servers. A client and server are generally remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other. A server can be a cloud server, also known as a cloud computing server or cloud host, which is a host product in the cloud computing service system, to solve the defects of large management difficulty and weak business scalability in traditional physical host and VPS service.

[0132] It should be understood that the various forms of flow shown above can be re-ordered, added to, or deleted from without departing from the scope of the present disclosure. For example, the steps recited in the present disclosure can be executed in parallel, executed in sequence, or executed in a different order, as long as the desired results of the present disclosure are achieved, and the present disclosure is not limited herein.

[0133] The specific embodiments described above are not intended to be limiting, and persons skilled in the art will appreciate that various modifications, combinations, sub-combinations and alternatives can be made to the specific embodiments without departing from the spirit and principles of the disclosure. Accordingly, the disclosure is not limited to the specific embodiments described above, but only by the scope of the appended claims.

Claims

1. A 3D printing method, characterized by, The method comprises the following steps: obtaining a required forming area difference of any two adjacent layers of the to-be-printed film layers in the to-be-printed part; determining an empty scanning area of a later to-be-printed film layer of the any two adjacent layers of the to-be-printed film layers according to the required forming area difference; the area of the empty scanning area is greater than or equal to the required forming area difference; scanning the empty scanning area and the forming area of the later to-be-printed film layer by using a laser, and the scanning energy of the empty scanning area is less than that of the forming area; before determining the empty scanning area of the later to-be-printed film layer of the any two adjacent layers of the to-be-printed film layers according to the required forming area difference, the method further comprises the following steps: determining the number M of the to-be-printed film layers which need to have the empty scanning area according to the required forming area difference and the forming thickness of the later to-be-printed film layer of the any two adjacent layers of the to-be-printed film layers; determining the empty scanning area of the later to-be-printed film layer of the any two adjacent layers of the to-be-printed film layers according to the required forming area difference, comprises the following steps: determining the empty scanning area of the later to-be-printed film layer of the any two adjacent layers of the to-be-printed film layers according to the required forming area difference in the i-th to-be-printed film layer to the i+M-th to-be-printed film layer; wherein i is a positive integer, and M is a positive integer; determining the number M of the to-be-printed film layers which need to have the empty scanning area according to the required forming area difference and the forming thickness of the later to-be-printed film layer of the any two adjacent layers of the to-be-printed film layers, comprises the following steps: obtaining the shrinkage line data corresponding to the required forming area difference in the historical printing data; determining the maximum length of the shrinkage line in a first direction according to the shrinkage line data; wherein the first direction intersects with the extension direction of the shrinkage line; determining the number M of the to-be-printed film layers which need to have the empty scanning area according to the ratio of the maximum length to the forming thickness of the later to-be-printed film layer of the any two adjacent layers of the to-be-printed film layers.

2. The 3D printing method according to claim 1, characterized in that, determining the empty scanning area of the later to-be-printed film layer of the any two adjacent layers of the to-be-printed film layers according to the required forming area difference, comprises the following steps: determining the area of the empty scanning area of the later to-be-printed film layer of the any two adjacent layers of the to-be-printed film layers according to the required forming area difference; determining the empty scanning area of the later to-be-printed film layer of the any two adjacent layers of the to-be-printed film layers according to the forming area of the later to-be-printed film layer of the any two adjacent layers of the to-be-printed film layers, and the empty scanning area surrounds the forming area.

3. The 3D printing method of claim 1, wherein, The j-th to-be-printed film layer comprises a plurality of to-be-printed rows, and at least part of the to-be-printed rows comprise empty scanning rows and forming rows; the empty scanning area comprises a plurality of the empty scanning rows, and the forming area comprises a plurality of the forming rows; scanning the empty scanning area and the forming area of the later to-be-printed film layer by using a laser, comprises the following steps: scanning the empty scanning area and the forming area of the later to-be-printed film layer by using a laser in a manner that the scanning directions of any two adjacent to-be-printed rows are opposite, while the scanning directions of the same to-be-printed row are the same.

4. The 3D printing method according to claim 3, characterized in that, scanning the empty scanning area and the forming area of the later to-be-printed film layer by using a laser in a manner that the scanning directions of any two adjacent to-be-printed rows are opposite, while the scanning directions of the same to-be-printed row are the same, comprises the following steps: In the same scanning direction of the to-be-printed row, the scanning directions of any two adjacent to-be-printed rows are opposite, and the scanning directions of the to-be-printed rows in any two adjacent to-be-printed film layers intersect, and the laser is used to scan the empty scanning area and the forming area of the latter to-be-printed film layer.

5. The 3D printing method of claim 1, wherein, The difference in the required forming area of any two adjacent to-be-printed film layers in the to-be-printed part is obtained, including: The required forming area of each to-be-printed film layer in the to-be-printed part is obtained. The difference in the required forming area of any two adjacent to-be-printed film layers is calculated according to the required forming area of each to-be-printed film layer.

6. A 3D printing apparatus for performing the 3D printing method according to any one of claims 1 to 5, characterized in that, It includes: The area difference obtaining module is used to obtain the difference in the required forming area of any two adjacent to-be-printed film layers in the to-be-printed part; The empty scanning area determining module is used to determine the empty scanning area of the latter to-be-printed film layer in any two adjacent to-be-printed film layers according to at least the difference in the required forming area; the area of the empty scanning area is greater than or equal to the difference in the required forming area; The laser scanning module is used to scan the empty scanning area and the forming area of the latter to-be-printed film layer by using laser, and the scanning energy of the empty scanning area is less than that of the forming area.

7. A 3D printing device, characterized by The 3D printing device includes: One or more processors; Storage device for storing one or more programs, When the one or more programs are executed by the one or more processors, the one or more processors implement the 3D printing method as claimed in any one of claims 1-5.

8. A storage medium having stored thereon a computer program, characterized in that The program is executed by the processor to implement the 3D printing method as claimed in any one of claims 1-5.

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