Three-dimensional shaping method and three-dimensional shaping apparatus

Abstract

To provide a three-dimensional shaping method with more effective abnormality detection and a three-dimensional shaping apparatus.SOLUTION: In a three-dimensional shaping method, a lamination shaped step where a powder-laying step of laying a powder and a shaped layer formation step of forming a shaped layer by beam irradiation to a laid powder layer are executed repeatedly. The three-dimensional shaping method includes: a first determination step of determining whether or not a first singular region where a height exceeds a first permissible value on a top face of the powder layer of an N-th layer or a top face of the shaped layer of the N-th layer (here, N is a natural number) is included; a second determination step of determining whether or not a second singular region where a height exceeds a second permissible value on a top face of the powder layer of an N+1-th layer or a top face of the shaped layer of the N+1-th layer is included; and an abnormality determination step of determining that an abnormality exists if the first singular region is determined to be included in the top face in the first determination step and the second singular region is determined to be included in the top face in the second determination step.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a three-dimensional printing method and a three-dimensional printing apparatus for forming a model from powder using a beam. [Background technology]

[0002] There is known a three-dimensional modeling method that includes an additive manufacturing step including a powder laying step of laying powder and a modeling layer forming step of forming a modeling layer by irradiating a beam onto the laid powder layer. The additive manufacturing step is repeatedly performed to form a model. In Patent Document 1, each time the additive manufacturing step is performed, it is determined whether there is an abnormality in the modeling layer. More specifically, if the difference in thickness between the nth powder layer and the nth modeling layer deviates from a specified range, it is determined that an abnormality has occurred. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2019 / 030837 Summary of the Invention [Problem to be solved by the invention]

[0004] In order to form a molded object in a short period of time, it is preferable to detect abnormalities such as the occurrence of sputtering more efficiently.

[0005] An object of the present disclosure is to provide a three-dimensional printing method and a three-dimensional printing apparatus that improve the efficiency of detecting anomalies. [Means for solving the problem]

[0006] A three-dimensional printing method according to at least one embodiment of the present disclosure includes: A three-dimensional modeling method in which an additive manufacturing step including a powder laying step of laying powder and a modeling layer forming step of forming a modeling layer by irradiating a beam onto the laid powder layer is repeatedly performed, a first determination step of determining whether a first unique region having a height exceeding a first tolerance is included on an upper surface of the Nth powder layer or an upper surface of the Nth modeling layer (where N is a natural number); A second determination step of determining whether a second unique region whose height exceeds a second tolerance is included on the upper surface of the powder layer of the (N+1)th layer or on the upper surface of the modeling layer of the (N+1)th layer; an anomaly determination step of determining that an anomaly exists when it is determined in the first determination step that the first unique region is included in the upper surface and when it is determined in the second determination step that the second unique region is included in the upper surface; Equipped with.

[0007] According to at least one embodiment of the present disclosure, a three-dimensional printing apparatus includes: a powder feeder configured to move horizontally and configured to feed powder; an illumination device configured to move horizontally and configured to illuminate the beam; an additive manufacturing control unit including a powder laying control unit for controlling the powder supplying device so as to lay the powder, and a modeling layer formation control unit for controlling the irradiation device so as to form a modeling layer by irradiating a beam onto the laid powder layer; Equipped with A three-dimensional printing apparatus in which the process by the additive manufacturing control unit is repeatedly executed, A height sensor for detecting the height of a measurement object; a first determination control unit for determining whether a first unique region, the height of which exceeds a first tolerance, is included on an upper surface of the Nth powder layer or an upper surface of the Nth modeling layer (where N is a natural number) based on a detection result of the height sensor; a second determination control unit for determining whether a second unique region, the height of which exceeds a second tolerance, is included on the upper surface of the powder layer of the (N+1)th layer or on the upper surface of the modeling layer of the (N+1)th layer, based on the detection result of the height sensor; an abnormality determination control unit that determines that an abnormality exists when the first determination control unit determines that the first unique region is included in the upper surface and the second determination control unit determines that the second unique region is included in the upper surface; and Equipped with. Effect of the Invention

[0008] According to the present disclosure, it is possible to provide a 3D printing method and a 3D printing apparatus that improve the efficiency of detecting anomalies. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram illustrating a basic configuration of a three-dimensional printing apparatus according to an embodiment. [Diagram 2] 11 is a schematic graph showing the results of measuring the maximum height of the upper surface of each modeling layer. [Figure 3A] FIG. 2 is a schematic diagram showing an overview of anomaly detection according to a first example. [Figure 3B] FIG. 11 is a schematic diagram showing an overview of anomaly detection according to a second example. [Figure 3C] FIG. 13 is a schematic diagram showing an overview of anomaly detection according to a third example. [Figure 4] FIG. 2 is a schematic diagram showing a functional configuration of a controller according to an embodiment. [Diagram 5] FIG. 4 is a schematic diagram showing details of anomaly detection according to a first method. [Figure 6A] FIG. 11 is a schematic diagram showing details of anomaly detection according to the second method (no anomaly). [Figure 6B] FIG. 11 is a schematic diagram showing details of anomaly detection according to the second method (anomaly is present). [Figure 7A] 11 is a flowchart showing a three-dimensional printing process according to a first example. [Figure 7B]13 is a flowchart showing a three-dimensional modeling process according to a second example. [Figure 7C] 13 is a flowchart showing a three-dimensional printing process according to a third example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, some embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of components described as the embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the present disclosure. For example, expressions expressing relative or absolute configuration, such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial," not only strictly express such a configuration, but also express a state in which there is a relative displacement with a tolerance or an angle or distance to the extent that the same function is obtained. For example, expressions indicating that things are in an equal state, such as "identical," "equal," and "homogeneous," not only indicate a state of strict equality, but also indicate a state in which there is a tolerance or a difference to the extent that the same function is obtained. For example, expressions describing shapes such as a rectangular shape or a cylindrical shape do not only refer to rectangular shapes, cylindrical shapes, etc. in the strict geometric sense, but also refer to shapes that include uneven portions, chamfered portions, etc., to the extent that the same effect is obtained. On the other hand, the expressions "comprise", "include", or "have" a certain element are not exclusive expressions excluding the presence of other elements. In addition, the same components are denoted by the same reference numerals and the description thereof may be omitted.

[0011] <Basic configuration of 3D modeling device 1> 1 is a schematic diagram showing a basic configuration of a three-dimensional printing apparatus 1 according to an embodiment of the present disclosure. The three-dimensional printing apparatus 1 includes a powder supplying device 3 for laying down powder that is a raw material for a three-dimensional object, an irradiation device 5 for irradiating a beam, and a base plate 9 that can be raised and lowered.

[0012] The operation of the three-dimensional modeling apparatus 1 to form a model is as follows. The powder supplying device 3 moves horizontally while laying powder on the base plate 9 to form the first powder layer 10. The irradiation device 5 then moves horizontally while irradiating the first powder layer 10 with a beam. The powder that constitutes the powder layer 10 is melted and solidified by the heat applied from the beam, thereby forming the first modeling layer 20. The base plate 9 moves down a distance equivalent to the thickness of the modeling layer 20.

[0013] Furthermore, the powder supplying device 3 forms a second powder layer 10 by laying powder on the first modeling layer 20, and the irradiation device 5 forms the second modeling layer 20 by irradiating the second powder layer 10 with a beam, and the base plate 9 descends again. The powder layer 10, the irradiation device 5, and the base plate 9 repeat the above operations to form a modeled object as stacked modeling layers 20. In the schematic diagram of FIG. 1, a third powder layer 10 is laid on the second modeling layer 20.

[0014] The powder supplied by the powder supplying device 3 may be a metal material such as iron, copper, aluminum, or titanium, or a non-metal material such as ceramic. The beam irradiated by the irradiation device 5 may be either a laser beam or an electron beam.

[0015] The powder supplying device 3, the irradiation device 5, and the base plate 9 are controlled by an additive manufacturing control unit 89, which is a component of a controller 90 of the three-dimensional modeling apparatus 1. The additive manufacturing control unit 89 has a base control unit 86 for controlling a base driving unit 8 that raises and lowers the base plate 9, a powder laying control unit 87 for controlling the powder supplying device 3 so as to lay powder, and a modeling layer formation control unit 88 for controlling the irradiation device 5 so as to form a modeling layer 20 by irradiating the powder layer 10 with a beam. The additive manufacturing control unit 89 repeats the control process, whereby the modeling layers 20 are laminated. Other components of the controller 90 will be described later.

[0016] The three-dimensional printing apparatus 1 further includes a height sensor 7 for detecting the height of a measurement object. The measurement object in this example is the powder layer 10 and / or the printing layer 20. That is, the height sensor 7 is configured to detect the height of a powder layer upper surface 11, which is the upper surface of the powder layer 10, and / or the height of a printing layer upper surface 22, which is the upper surface of the printing layer 20.

[0017] In this example, the height sensor 7 employs a fringe projection method for measuring height. More specifically, the height sensor 7 includes a projector for projecting a fringe pattern onto the upper surface of the measurement object, two cameras for capturing images of the projected fringe pattern, and an analysis unit.

[0018] The analysis unit is configured to generate three-dimensional data indicating the surface texture of the upper surface of the measurement object based on the images of the fringe patterns generated by each of the two cameras. More specifically, the analysis unit is configured to convert the two-dimensional coordinates in the camera coordinate system of the fringe patterns shown in each image into three-dimensional coordinates in the world coordinate system using a specified optical conversion formula. The coordinate conversion is performed for each of the multiple pixels that make up the image. The analysis unit may be incorporated in the controller 90, or may be an electronic calculation device separate from the controller 90.

[0019] <Spatter detection> The three-dimensional printing apparatus 1 of this embodiment is equipped with a function for detecting spatters. Spatters are particles scattered from the melted portion of the powder layer 10 irradiated with a beam. If spatters remain in the powder layer 10 or the printing layer 20, there is a risk of a printing defect such as an unmelted portion occurring around the spatters. For this reason, the three-dimensional printing apparatus 1 of this embodiment is adapted to detect spatters that cause printing defects. The detection principle and process will be outlined below with reference to FIG. 2 and FIG. 3A to FIG. 3C.

[0020] FIG. 2 is a schematic graph showing the results of measuring the maximum height of the top surface 22 of each of the modeling layers 20 that make up the modeled object. The graph is obtained by using the height sensor 7 to measure the maximum height of the top surface 22 of the uppermost modeling layer each time a modeling layer 20 is formed. The horizontal axis of the graph indicates the number of modeling layers 20, and for example, "1" on the horizontal axis indicates the top surface 22 of the first modeling layer 20. Additionally, "R" and "M" on the horizontal axis are both natural numbers (however, R <M)。

[0021] As described above, each time one modeling layer 20 is formed, the base plate 9 descends a distance equivalent to the thickness of the modeling layer 20. Therefore, the maximum height of the modeling layer upper surface 22 of each layer is expected to ideally be the same value. However, if spatter accumulates during the stacking process of the modeling layers 20, part of the modeling layer upper surface 22 rises, and the maximum height increases significantly. In the graph, spatter accumulates on each of the modeling layers 20 in the Rth and M-1th layers, and the maximum height (point P R and P M-1 ) exceeds the first threshold (dashed line L).

[0022] According to the findings of the inventors of the present application, when the stacking of the modeling layers 20 is continued without performing a process to remove the spatters, the spatters may or may not disappear. In the graph, the spatters contained in the Rth modeling layer 20 disappear after the R+1th modeling layer 20 is formed, and at point P R+1 The maximum height indicated by point P is below the first threshold (dashed line L). This is because spatters were released to the outside during the process of forming the (R+1)th modeling layer 20, and it is unlikely that such spatters will cause modeling abnormalities. On the other hand, the spatters contained in the (M-1)th modeling layer 20 remain even after the (M)th and subsequent modeling layers 20 are stacked, and the maximum height indicated by point P M and point P M+1 The maximum height indicated by the dashed line also exceeds the first threshold value (dashed line L). In this way, the remaining spatter can cause shaping abnormalities.

[0023] From the above, if any natural number is defined as N, spatters generated in the Nth modeling layer 20 can be classified into spatters that disappear as the N+1th modeling layer 20 is formed, and spatters that remain after the N+1th modeling layer 20 is formed. If abnormality detection is not performed when the former type of spatter occurs and abnormality detection is performed when the latter type of spatter occurs, the abnormality detection process can be made more efficient. Therefore, in this embodiment, abnormality detection is performed when the height of the modeling layer upper surface 22 exceeds the first threshold value (L) in both the Nth and N+1th layers.

[0024] Furthermore, the inventors of the present application have found that efficient anomaly detection is not limited to measuring the maximum height of each of the top surfaces 22 of the Nth and N+1th layers. Two other examples will be described below.

[0025] In the first other example, the maximum height of the N+1th powder layer 10 is measured instead of the maximum height of the N+1th modeling layer 20. That is, the maximum height of the Nth modeling layer 20 and the maximum height of the N+1th powder layer 10 are measured. This is based on the knowledge obtained by the inventor that the spatter contained in the Nth modeling layer 20 can be classified into spatter that disappears with the formation of the N+1th powder layer 10 and spatter that remains after the formation of the N+1th powder layer 10. That is, when the maximum height of the Nth modeling layer 20 exceeds the first threshold (dashed line L) and the maximum height of the N+1th powder layer 10 exceeds the second threshold (not shown), an abnormality is detected. Note that the second threshold may be the same value as the first threshold or may be a value different from the first threshold.

[0026] In the second other example, the maximum heights of the Nth and N+1th powder layers 10 are measured instead of the maximum heights of the Nth and N+1th modeling layers 20. This is based on the inventor's knowledge that spatters contained in the Nth powder layer 10 can be classified into spatters that disappear with the formation of the N+1th powder layer 10 and spatters that remain after the formation of the N+1th powder layer 10. That is, when both the maximum height of the Nth powder layer 10 and the maximum height of the N+1th powder layer 10 exceed the second threshold, an abnormality is detected.

[0027] Summarizing the findings obtained by the inventors, the following three patterns (A1) to (A3) are given as examples of objects whose heights can be measured for anomaly detection. The graph shown in FIG. 3 shows the results of measuring the maximum height when the object is the (A2) pattern. (A1) Nth modeling layer 20 and N+1th powder layer 10 (first example) (A2) Each of the Nth and N+1th modeling layers 20 (second example) (A3) Powder layers 10 of the Nth layer and the N+1th layer (third example)

[0028] 3A is a schematic diagram showing an overview of anomaly detection according to the first example. Assume that a first unique region 51A (51) with an abnormal height is included on top surface 22 of the Nth modeling layer. In this case, it is deemed that sputtering has occurred in the Nth modeling layer 20. Then, if a second unique region 52A (52) with an abnormal height is included on top surface 11 of the (N+1)th powder layer, it is deemed that sputtering remains, and therefore it is determined that there is abnormal sputtering.

[0029] FIG. 3B is a schematic diagram showing an overview of anomaly detection according to a second example. Assume that the top surface 22 of the Nth modeling layer includes a first unique region 51B (51) with an abnormal height. In this case, it is deemed that sputtering has occurred in the Nth modeling layer 20. If the top surface 22 of the (N+1)th modeling layer includes a second unique region 52B (52) with an abnormal height, it is deemed that sputtering remains, and therefore it is determined that there is abnormal sputtering. Note that if N=M-1, the height of the first unique region 51B is equal to or greater than the point P in FIG. 2. M-1 The height of the second unique area 52B corresponds to point P in FIG. M This applies.

[0030] 3C is a schematic diagram showing an overview of anomaly detection according to a third example. Assume that upper surface 11 of the Nth powder layer includes first unique region 51C (51) having an abnormal height. In this case, it is deemed that sputtering has occurred in the Nth powder layer 10. If upper surface 11 of the (N+1)th powder layer includes second unique region 52C (52) having an abnormal height, it is deemed that sputtering remains, and therefore it is determined that abnormal sputtering exists.

[0031] 3A to 3C as schematic diagrams, the first unique regions 51A to 51C (51) and the second unique regions 52A to 52C (52) are rectangular regions, but the present disclosure is not limited thereto. The first unique region 51 and the second unique region 52 may both be minute circular regions. In this case, the first unique region 51 and the second unique region 52 may also be referred to as singular points.

[0032] <Details of Controller 90> The functional configuration of the controller 90 for performing the above abnormality detection will be described. The three patterns shown in (A1) to (A3) above will be comprehensively described below. FIG. 4 is a schematic diagram showing the functional configuration of the controller 90 according to an embodiment of the present disclosure. The controller 90 includes a first determination control unit 91, a second determination control unit 92, and an abnormality determination control unit 93.

[0033] The first determination control unit 91 is configured to determine whether the top surface 11 of the Nth powder layer or the top surface 22 of the Nth modeling layer includes a first unique region 51 whose height exceeds a first tolerance based on the detection result of the height sensor 7. The first tolerance is either the first threshold value or the second threshold value described above. If the first exemplary pattern or the second exemplary pattern is adopted, the first tolerance is the first threshold value, and if the third exemplary pattern is adopted, the first tolerance is the second threshold value.

[0034] The second determination control unit 92 is configured to determine whether the second unique region 52 whose height exceeds the second tolerance is included on the powder layer upper surface 11 of the (N+1)th layer or the modeling layer upper surface 22 of the (N+1)th layer, based on the detection result of the height sensor 7. The second tolerance is either the first threshold value or the second threshold value described above. If the first exemplary pattern or the third exemplary pattern is adopted, the second tolerance is the second threshold value, and if the second exemplary pattern is adopted, the second tolerance is the first threshold value.

[0035] The abnormality judgment control unit 93 is configured to determine that an abnormality (i.e., abnormal sputtering) exists when the first judgment control unit 91 determines that a first unique region 51 is included and when the second judgment control unit 92 determines that a second unique region 52 is included.

[0036] According to the above configuration, when the spatters generated in the Nth layer disappear, it is not determined that the second unique region 52 is included in the powder layer upper surface 11 or the fabrication layer upper surface 22, and the abnormality determination control unit 93 does not determine that an abnormality exists. On the other hand, when the spatters remain, the first determination control unit 91 determines that the first unique region 51 is included in the powder layer upper surface 11 or the fabrication layer upper surface 22, and the second determination control unit 92 determines that the second unique region 52 is included in the powder layer upper surface 11 or the fabrication layer upper surface 22. In this case, it is determined that an abnormality exists. In this way, even if spatters that are unlikely to cause a fabrication abnormality occur, it is possible to eliminate the need for a process of reporting the occurrence, and thus a three-dimensional printing method (three-dimensional printing device 1) that makes the detection of abnormalities more efficient is realized.

[0037] Continuing to refer to FIG. 4, the functional configuration of the controller 90 will be described. When the first unique region 51 in the Nth layer and the second unique region 52 in the N+1th layer occur, it is considered that these two unique regions are caused by different sputters. More specifically, it is considered that the sputters in the Nth powder layer 10 or the modeling layer 20 disappear during the formation process of the N+1th powder layer 10 or the modeling layer 20, and new sputters occur during the formation process. In other words, the first unique region 51 and the second unique region 52 may occur even if no residual sputter phenomenon occurs. Therefore, it is preferable to determine whether the first unique region 51 and the second unique region 52 are caused by the same sputters.

[0038] Therefore, the controller 90 according to an embodiment of the present disclosure includes a matching unit 94. When the first determination control unit 91 determines that the first unique region 51 is included and the second determination control unit 92 determines that the second unique region 52 is included, the matching unit 94 is configured to determine whether the shortest distance between the first unique region 51 and the second unique region 52 in a planar view is below a specified distance. There are several methods for determining whether the shortest distance is below the specified distance.

[0039] A first method is to calculate the shortest distance between first unique region 51 and second unique region 52. Fig. 5 shows the (N+1)th powder layer 10 in the first example pattern (i.e., the above-mentioned (A1) pattern). In the figure, the second unique region 52A (52) confirmed on top surface 11 of the (N+1)th powder layer is shown by a solid line, and the first unique region 51A (51) confirmed on top surface 22 of the Nth modeling layer is shown by a dashed dotted line.

[0040] The first determination control unit 91 specifies the coordinates of the first unique region 51A when it is determined that the first unique region 51A is included. The coordinates that can be specified through the photographing by the above-mentioned two cameras (not shown) may be coordinates indicating the center of the first unique region 51A, or may be a plurality of coordinates indicating the outer edge of the first unique region 51A. Similarly, the second determination control unit 92 specifies the coordinates of the second unique region 52A when it is determined that the second unique region 52B is included. The abnormality determination control unit 93 calculates the shortest distance (dimension R in FIG. 5) based on the coordinates of the first unique region 51A and the coordinates of the second unique region 52A. The abnormality determination control unit 93 compares the shortest distance with a specified distance and determines whether the shortest distance is less than the specified distance. Note that when the first unique region 51A and the second unique region 52A partially or completely overlap in a planar view, the shortest distance is 0.

[0041] The first method is also applicable to the second example pattern (i.e., the above-mentioned (A2) pattern) and the third example pattern (i.e., the above-mentioned (A3) pattern). In order to avoid duplication of explanation, detailed explanation will be omitted.

[0042] As a second method, a method of applying mesh division can be given. This method is effective in that it can eliminate the need for a process of calculating a specific value of the shortest distance. A specific example of the second method is as follows.

[0043] 6A and 6B are schematic diagrams showing details of anomaly detection according to the second method. Both diagrams show the Nth powder layer 10 and the N+1th powder layer 10 according to the first exemplary pattern (i.e., the above-mentioned (A1) pattern). The first determination control unit 91 divides the Nth modeling layer upper surface 22 into a plurality of partitioned regions 57. Furthermore, the first determination control unit 91 identifies which partitioned region 57 contains the first peculiar region 51A (51). In the example of the schematic diagrams of FIGS. 6A and 6B, the Nth modeling layer upper surface 22 is divided into four partitioned regions 57, and the first determination control unit 91 identifies that the upper left partitioned region 57 contains the first peculiar region 51A.

[0044] The second determination control unit 92 executes the same determination process as the first determination control unit 91. More specifically, the second determination control unit 92 divides the powder layer top surface 11 of the (N+1)th layer into four divided regions 57 according to the same pattern as the first determination control unit 91. Furthermore, the second determination control unit 92 identifies which divided region 57 includes the second unique region 52A (52). In the example of FIG. 6A, the second determination control unit 92 identifies that the upper left divided region 57 includes the second unique region 52A. In the example of FIG. 6B, it identifies that the upper right divided region 57 includes the second unique region 52A.

[0045] The collation unit 94 determines that the shortest distance is less than the prescribed distance when the demarcated area 57 containing the first unique region 51A and the demarcated area 57 containing the second unique region 52A are the same. In the example of Fig. 6A, the first unique region 51A and the second unique region 52A are both contained in the upper left demarcated area 57, so it is determined that the shortest distance is less than the prescribed distance. On the other hand, in the example of Fig. 6B, the first unique region 51A and the second unique region 52B are each contained in different demarcated areas 57, so it is determined that the shortest distance is equal to or greater than the prescribed distance.

[0046] The second method is also applicable to the second exemplary pattern (i.e., the above-mentioned pattern (A2)) and the third exemplary pattern (i.e., the above-mentioned pattern (A3)). In the second example, the first judgment control unit 91 divides the Nth modeling layer upper surface 22 into a plurality of partitioned regions 57, and the second judgment control unit 92 divides the N+1th modeling layer upper surface 22 into a plurality of partitioned regions 57. In the third example, the first judgment control unit 91 divides the Nth powder layer upper surface 11 into a plurality of partitioned regions 57, and the second judgment control unit 92 divides the N+1th powder layer upper surface 11 into a plurality of partitioned regions 57. In order to avoid duplication of explanation, detailed explanation will be omitted.

[0047] The technical advantages of the first method and the second method will be described. If the spatter generated in the Nth powder layer 10 or the Nth modeling layer 20 remains when the N+1th powder layer 10 or the N+1th modeling layer 20 is formed, the shortest distance between the first unique region 51 and the second unique region 52 falls below the specified distance, and an abnormality is detected. On the other hand, the spatter generated in the Nth powder layer 10 or the Nth modeling layer 20 may disappear with the formation of the N+1th powder layer 10 or the N+1th modeling layer 20, and another spatter may occur in the N+1th layer. In this case, the shortest distance between the first unique region 51 and the second unique region 52 is equal to or greater than the specified distance, so it is not determined that there is an abnormality. Therefore, spatter that is likely to cause modeling abnormalities can be detected more reliably.

[0048] Moreover, according to the second technique, it is possible to determine whether the shortest distance between the first unique area 51 and the second unique area 52 is less than the specified distance without measuring the shortest distance. Therefore, the control process executed by the collation unit 94 can be simplified.

[0049] In the second technique, the first determination control unit 91 may determine whether the first unique region 51A (51) is included in each of all of the partitioned regions 57 constituting the upper surface 22 of the Nth modeling layer. In this case, the second determination control unit 92 also determines whether the second unique region 52B (52) is included in each of all of the partitioned regions 57 constituting the upper surface 11 of the (N+1)th powder layer.

[0050] According to the above configuration, it is determined whether the first unique region 51 and the second unique region 52 have occurred in each divided region 57. Therefore, spatters that are likely to cause printing abnormalities can be detected more reliably.

[0051] <Three-dimensional modeling process (first example)> A three-dimensional modeling process according to a first example will be described with reference to FIG. 7A. The three-dimensional modeling process is a process executed by a processor (hereinafter, may be simply referred to as a processor) of the controller 90. In FIG. 7A, the above-mentioned pattern (A1) is adopted. That is, an abnormality determination is performed through height measurement of each of the Nth modeling layer 20 and the N+1th powder layer 10. In the following description, "step" may be abbreviated as "S".

[0052] In the three-dimensional printing process shown in Fig. 7A, the Nth, N+1th, and N+2th modeling layers 20 are stacked in this order (the same applies to the three-dimensional printing processes shown in Figs. 7B and 7B, which will be described later). At the start of this control process, N=1.

[0053] First, the processor controls the powder supplying device 3 to lay powder on the base plate 9 (S10). Next, the processor controls the irradiation device 5 to form the first modeling layer 20 by irradiating the laid first powder layer 10 with a beam (S20). The processor that executes S10 is an example of the powder laying control unit 87, and the processor that executes S20 is an example of the modeling layer formation control unit 88. By executing S20, the Nth (i.e., first) modeling layer 20 is formed.

[0054] Next, the processor determines whether the first unique region 51A (51) is included in the top surface 22 of the Nth (i.e., first) modeling layer 20 based on the measurement result of the height sensor 7 (S25). In a more specific example, the processor divides the top surface 22 of the modeling layer 20 into a plurality of partitioned regions 57 and determines whether the first unique region 51A is included in at least one of the partitioned regions 57. If it is determined that the first unique region 51A is not included in any of the partitioned regions 57 (S25: NO), the processor shifts the process to S30. On the other hand, if it is determined that the first unique region 51A is included in at least one of the partitioned regions 57 (S25: YES), the processor identifies the partitioned region 57 that includes the first unique region 51A (S27) and shifts the process to S30. The processor that executes S25 and S27 is an example of the first determination control unit 91.

[0055] Next, the processor controls the base driving unit 8 so as to lower the base plate 9 (S30). The processor that executes S30 is an example of the base control unit 86. Furthermore, the processor controls the powder supplying device 3 so as to lay the second powder layer 10 on the first modeling layer 20 (S40). S40 is the same process as S10.

[0056] Next, the processor determines whether the powder layer upper surface 11 of the (N+1)th layer (i.e., the second layer) powder layer 10 includes the second unique region 52A (52) based on the detection result of the height sensor 7 (S45). In a more specific example, the processor divides the powder layer upper surface 11 into a plurality of partitioned regions 57 and determines whether the second unique region 52A is included in at least one of the plurality of partitioned regions 57. If it is determined that the second unique region 52A is not included in any of the partitioned regions 57 (S45: NO), the processor shifts the process to S70. On the other hand, if it is determined that the second unique region 52A is included in at least one of the partitioned regions 57 (S45: YES), the processor identifies the partitioned region 57 including the second unique region 52A (S47) and shifts the process to S50. The processor that executes S45 and S47 is an example of the second determination control unit 92.

[0057] After executing S47, the processor determines whether the shortest distance between the first unique region 51A and the second unique region 52A in a planar view is less than a specified distance (S50). That is, an abnormality determination is performed through height measurement of each of the Nth (i.e., first) modeling layer 20 and the N+1th (i.e., second) powder layer 10. As a more specific example, it is determined whether the divided region 57 identified in S27 is the same as the divided region 57 identified in S47. If the two divided regions 57 are different, it is determined that the shortest distance is equal to or greater than the specified distance (S50: NO). In this case, the processor transitions to S70.

[0058] On the other hand, if the two partitioned regions 57 are the same, it is determined that the shortest distance is shorter than the specified distance (S50: YES). In this case, the processor determines that there is an abnormality (i.e., abnormal sputtering) (S55) and ends the process. In S55, a process of notifying that an abnormality has occurred may be executed. The processor that executes S50 is an example of the collation unit 94, and the processor that executes S55 is an example of the abnormality determination control unit 93.

[0059] If a negative determination is made in S45 or S50 (S45: NO, S50: NO), the processor controls the irradiation device 5 to form the N+1th (i.e., second) modeling layer 20 (S70). By executing S70, the N+1th (i.e., second) modeling layer 20 is formed. S70 is the same process as S20.

[0060] Then, the processor resets N+1 to N (S72). By executing S72, the second modeling layer 20 is regarded as the Nth modeling layer 20. Then, the processor determines whether spatters are included on the modeling layer upper surface 22 of the Nth (i.e., second) modeling layer 20 (S75). If a negative determination is made in S75 (S75: NO), the processor transitions to S90. On the other hand, if a positive determination is made in S75 (S75: YES), the processor identifies the partitioned region 57 including the spatters (S77). S75 is the same process as S25, and S77 is the same process as S27. That is, the processor that executes S75 and S77 is an example of the first determination control unit 91.

[0061] Next, the processor controls the base drive unit 8 so as to lower the base plate 9 (S90). S90 is the same process as S30.

[0062] Next, the processor judges whether to continue the process (S95). If it is judged that the process is to be continued (S95: YES), the processor shifts the process to S40. In S45, it is judged whether the second unique region 52A is included in the powder layer upper surface 11 of the N+1th layer (i.e., the third layer). If it is judged that the second unique region 52A is included (S45: YES), an abnormality judgment is executed through the height measurement of each of the Nth layer (i.e., the second layer) modeling layer 20 and the N+1th layer (i.e., the third layer) powder layer 10 (S50). As a more specific example, it is judged whether the partitioned region 57 identified in the immediately preceding S77 is the same as the partitioned region 57 identified in the immediately preceding S47. Thereafter, the same process as above is repeated. If it is judged that the process is not to be continued (S95: NO), the processor ends the three-dimensional modeling process.

[0063] As described above, in S25 and S75, it is determined whether the first unique region 51A (51) is included in the top surface 22 of the Nth modeling layer. With this configuration, it is possible to more reliably detect spatters generated by irradiating the Nth powder layer 10 with a beam. This makes it possible to more reliably detect spatters that are likely to cause modeling abnormalities.

[0064] As described above, in S45, it is determined whether the second unique region 52A is included in the powder layer upper surface 11 of the N+1th layer. According to this configuration, if the sputter generated in the Nth modeling layer 20 remains after S40 for forming the N+1th powder layer 10, the occurrence of the second unique region 52A can be detected before S70 for forming the N+1th modeling layer 20. This makes it possible to prevent the occurrence of unmelted parts in the modeling layer 20 that may occur when the N+1th powder layer 10 is irradiated with a beam. Furthermore, according to the above embodiment, a technical advantage is obtained in that the second unique region 52A on the powder layer upper surface 11 is easily detected. This is because the unevenness that will be formed on the modeling layer upper surface 22 due to melting and solidification during beam irradiation has not yet been formed on the powder layer upper surface 11. If a protuberance caused by the deposition of sputters is formed on the relatively flat powder layer upper surface 11, the protuberance can be easily detected as the second unique region 52A (i.e., the unique point).

[0065] The three-dimensional modeling process according to the first example is not limited to the example shown in FIG. 7A. For example, if it is determined that the first unique region 51A is not included in the upper surface 22 of the Nth modeling layer (S25: NO or S75: NO), S45 immediately after the determination is made may be skipped. Such a control process can be realized by inserting a determination process for skipping or not after S40 and before S45. The determination process functions as a skip determination unit (not shown) of the controller 90. According to this configuration, if sputtering does not occur in the Nth modeling layer 20, there is a high possibility that sputtering will not occur in the N+1th powder layer 10. At this time, S45 is skipped and the process proceeds to S70, which can omit unnecessary detection processes for sputtering and further improve the efficiency of abnormality detection.

[0066] 7A, it is determined whether the first unique region 51A is included in the upper surface 22 of the modeling layer of all layers, but the present disclosure is not limited thereto. For example, it may be determined whether the first unique region 51A is included in the upper surface 22 of the modeling layer only in even-numbered (2N) layers such as the second layer and the fourth layer. In this case, it is determined whether the second unique region 52A is included in the upper surface 11 of the powder layer only in odd-numbered layers. Alternatively, it may be determined whether the first unique region 51A is included in the upper surface 22 of the modeling layer only in odd-numbered (2N+1) layers such as the first layer and the third layer.

[0067] Some of the steps of the three-dimensional printing process shown in Fig. 7A may be executed by a human instead of a processor. For example, the step (S27) of identifying the divided area 57 including the first unique area 51A may be executed by a human while checking the photographing results of the camera. Similarly, S47 may be executed by a human. Furthermore, the step (S50) of determining whether the divided area 57 including the first unique area 51A is the same as the divided area 57 including the second unique area 52A may also be executed by a human.

[0068] <Three-dimensional modeling process (second example)> A three-dimensional printing process according to a second example will be described with reference to FIG. 7B. In FIG. 7B, the above-mentioned pattern (A2) is adopted. That is, an abnormality determination is performed through height measurement of each of the Nth and N+1th printing layers 20. In FIG. 7B, the same step numbers are assigned to the same control processes as in FIG. 7A. Descriptions of the control processes may be omitted or omitted below. At the start of this control process, N=1.

[0069] The processor executes S10 and S20 described above. As a result, the Nth (i.e., first) modeling layer 20 is formed on the base plate 9. Furthermore, the processor determines whether the first unique region 51B (51) is included in the modeling layer upper surface 22 of the Nth (i.e., first) modeling layer 20 based on the measurement result of the height sensor 7 (S25). If a positive determination is made in S25 (S25: YES), the processor identifies the partitioned region 57 including the first unique region 51B (S27) and shifts the process to S30. If a negative determination is made in S25 (S25: NO), the processor shifts the process to S30. The processor that executes S25 and S27 is an example of the first determination control unit 91.

[0070] Next, the processor sequentially executes the above-mentioned S30, S40, and S70, and further forms the (N+1)th (i.e., second) modeling layer 20.

[0071] The processor determines whether the second unique region 52B (52) is included in the top surface 22 of the (N+1)th layer (i.e., the second layer) based on the detection result of the height sensor 7 (S85). In a more specific example, the processor divides the top surface 22 of the modeling layer into a plurality of partitioned regions 57 and determines whether the second unique region 52B is included in at least one of the partitioned regions 57. If it is determined that the second unique region 52B is not included in any of the partitioned regions 57 (S85: NO), the processor shifts the process to S90. On the other hand, if it is determined that the second unique region 52B is included in at least one of the partitioned regions 57 (S85: YES), the processor identifies the partitioned region 57 that includes the second unique region 52B (S87). The processor that executes S85 and S87 is an example of the second determination control unit 92.

[0072] After executing S87, the processor determines whether the shortest distance between the first unique region 51B and the second unique region 52B in a planar view is less than a specified distance (S100). S100 is the same process as S50 (see FIG. 7A) according to the first example. If a positive determination is made in S100 (S100: YES), the processor determines that an abnormality (i.e., abnormal sputtering) exists (S155). S155 is the same process as S55 according to the first example. After executing S155, the processor ends this control process. The processor that executes S100 is an example of the collation unit 94, and the processor that executes S155 is an example of the abnormality determination control unit 93.

[0073] If a negative determination is made in S85 or S100 (S85: NO, S100: NO), the processor executes S90 described above. After that, the processor resets N+1 to N (S92). By executing S92, the second modeling layer 20 is regarded as the Nth modeling layer 20. The processor determines whether to continue processing (S95). If a positive determination is made (S95: YES), the processor transitions to S10. If a negative determination is made (S95: NO), the processor terminates this control process.

[0074] As described above, in both S25 and S85, the height of the upper surface 22 of the modeling layer 20 is measured. This makes it possible to compare the position of the first unique region 51B in the Nth modeling layer 20 with the position of the second unique region 52B in the (N+1)th modeling layer 20 in S100. This makes it possible to more accurately compare the position of the first unique region 51B with the position of the second unique region 52B.

[0075] <Three-dimensional modeling process (third example)> A three-dimensional printing process according to the third example will be described with reference to FIG. 7C. In FIG. 7C, the above-mentioned pattern (A3) is adopted as the object to be measured for height for detecting anomalies. That is, anomaly determination is performed through height measurement in each of the powder layers 10 of the Nth layer and the N+1th layer. In FIG. 7C, the same step numbers are given to the same control processes as those in FIG. 7A and FIG. 7B. The description of the control processes may be omitted or omitted below. At the start of this control process, N=1.

[0076] The processor executes the above-mentioned S10. As a result, the first powder layer 10 is laid. Next, the processor determines whether the powder layer upper surface 11 of the Nth layer (i.e., the first layer) of the powder layer 10 includes the first unique region 51C (51) based on the detection result of the height sensor 7 (S15). In a more specific example, the processor divides the powder layer upper surface 11 into a plurality of partitioned regions 57 and determines whether the first unique region 51C is included in at least one of the plurality of partitioned regions 57. If it is determined that the first unique region 51C is not included in any of the partitioned regions 57 (S15: NO), the processor shifts the process to S20. On the other hand, if it is determined that the first unique region 51C is included in at least one of the partitioned regions 57 (S15: YES), the processor identifies the partitioned region 57 including the first unique region 51C (S17) and shifts the process to S20. The processor that executes S15 and S17 is an example of the first determination control unit 91.

[0077] Next, the processor executes the above-mentioned S20 and S30 to form the Nth (i.e., first) modeling layer 20. Furthermore, the processor executes S40 to lay down the (N+1)th (i.e., second) powder layer 10.

[0078] Thereafter, the processor determines whether or not second unique region 52C (52) is included in powder layer upper surface 11 of powder layer 10 of the (N+1)th layer (i.e., the second layer) based on the detection result of height sensor 7 (S45). As a more specific example, the processor divides powder layer upper surface 11 into a plurality of partitioned regions 57 and determines whether or not second unique region 52C is included in at least one of the plurality of partitioned regions 57. If it is determined that second unique region 52C is not included in any of the partitioned regions 57 (S45: NO), the processor proceeds to S70.

[0079] On the other hand, if it is determined that at least one of the divided regions 57 includes the second unique region 52C (S45: YES), the processor identifies the divided region 57 including the second unique region 52C (S47). After that, the processor determines whether the shortest distance between the first unique region 51C and the second unique region 52C in a plan view is less than the specified distance (S50). If a positive determination is made in S50 (S50: YES), the processor determines that an abnormality (i.e., abnormal sputtering) exists (S55) and ends this control process. If a negative determination is made in S50 (S50: NO), the processor shifts the process to S70 and executes the above-mentioned S70 to S95. The processor that executes S45 and S47 is an example of the second determination control unit 92, the processor that executes S50 is an example of the collation unit 94, and the processor that executes S55 is an example of the abnormality determination control unit 93.

[0080] As described above, in both S15 and S45, height measurement of powder layer upper surface 11 of powder layer 10 is performed. This makes it possible to compare the position of first unique region 51C in the Nth powder layer 10 with the position of second unique region 52C in the (N+1)th powder layer 10 in S50. This makes it possible to more accurately compare the positions of first unique region 51C and second unique region 52C.

[0081] <Other> The controller 90 is configured by a computer and includes a processor, a memory (storage medium), and an external communication interface. The processor is a CPU, a GPU, an MPU, a DSP, or a combination thereof. The processor according to other embodiments may be realized by an integrated circuit such as a PLD, an ASIC, an FPGA, or an MCU. The memory is configured to store various data temporarily or non-temporarily, and is realized by at least one of a RAM, a ROM, and a flash memory, for example. The processor executes various control processes according to instructions of a program loaded into the memory.

[0082] 1 may be a laser displacement meter. The laser displacement meter measures the height of the powder layer upper surface 11 or the modeling layer upper surface 22 while moving in the horizontal direction. Even in this case, the height sensor 7 can measure the surface properties of the powder layer upper surface 11 or the modeling layer upper surface 22.

[0083] A molded object having a very small size in plan view may be formed. In this case, the powder layer 10 and the molding layer 20 are very small in plan view. Therefore, when the first unique region 51A is confirmed on the upper surface 22 of the Nth molding layer and the second unique region 52A is confirmed on the upper surface 22 of the N+1th molding layer, it may be automatically determined that spatter remains. That is, the collation unit 94 of the controller 90 is not an essential component. Here, the above pattern (A1) has been described as an example, but even if the above patterns (A2) and (A3) are adopted, the collation unit 94 is not an essential component of the controller 90 for the same reason.

[0084] <Summary> The contents described in the above-mentioned embodiments can be understood, for example, as follows.

[0085] 1) A three-dimensional printing method according to at least one embodiment of the present disclosure, A three-dimensional modeling method in which an additive manufacturing step including a powder laying step (S10) of laying powder and a modeling layer formation step (S20) of forming a modeling layer (20) by irradiating a beam onto the laid powder layer (10) is repeatedly performed, A first determination step (S15, S25) of determining whether a first unique region (51) whose height exceeds a first tolerance is included on the top surface of the Nth powder layer (powder layer top surface 11) or the top surface of the Nth modeling layer (modeling layer top surface 22) (where N is a natural number); A second determination step (S45, S85) of determining whether a second unique region (52) whose height exceeds a second tolerance is included on the upper surface of the powder layer (powder layer upper surface 11) of the (N+1)th layer or the upper surface of the modeling layer (modeling layer upper surface 22) of the (N+1)th layer; an abnormality determination step (S55, S155) of determining that there is an abnormality when it is determined in the first determination step that the first unique region is included in the upper surface and when it is determined in the second determination step that the second unique region is included in the upper surface; Equipped with.

[0086] According to the inventor's findings, spatters generated in the Nth powder layer or the Nth modeling layer are classified into spatters that disappear with the execution of the N+1th additive manufacturing step and spatters that remain after the N+1th additive manufacturing step. The former spatters are unlikely to cause modeling abnormalities, so there is no need to notify the detection of them. On the other hand, the latter spatters are likely to cause modeling abnormalities such as the generation of unmelted parts in the modeling layer, so it is necessary to notify the detection of them. In this regard, according to the configuration of 1) above, if the spatters generated in the Nth layer disappear, it is not determined in the second determination step that the second unique region is included in the upper surface, and it is not determined that there is an abnormality. On the other hand, if the spatters remain, it is determined in the first determination step that the first unique region is included in the upper surface, and it is determined in the second determination step that the second unique region is included in the upper surface. In this case, it is determined that there is an abnormality. In this way, even if spatters occur that are unlikely to cause printing abnormalities, the process of reporting the occurrence can be eliminated, thereby realizing a three-dimensional printing method that makes the detection of abnormalities more efficient.

[0087] 2) In some embodiments, the three-dimensional modeling method according to 1) above includes the steps of: a comparison step (S50, S100) of determining whether a shortest distance between the first unique region and the second unique region in a plan view is less than a specified distance when the first determination step determines that the first unique region is included in the upper surface and the second determination step determines that the second unique region is included in the upper surface, In the abnormality determination step, if it is determined that the shortest distance is shorter than the specified distance, it is determined that the abnormality exists.

[0088] According to the configuration of 2) above, if the spatter generated in the Nth layer remains when the N+1th additive manufacturing step is performed, the shortest distance between the first unique region and the second unique region falls below the specified distance, and an abnormality is detected. On the other hand, there are cases where the spatter generated in the Nth layer disappears with the execution of the N+1th additive manufacturing step, and another spatter is generated in the N+1th layer. In this case, the shortest distance between the first unique region and the second unique region becomes equal to or greater than the specified distance, and therefore it is not determined that there is an abnormality. Therefore, spatter that is likely to cause a modeling abnormality can be detected more reliably.

[0089] 3) In some embodiments, the three-dimensional modeling method according to 2) above comprises the steps of: In the first determination step, the upper surface of the Nth powder layer or the upper surface of the Nth modeling layer is divided into a plurality of partitioned regions (57) to identify which of the partitioned regions includes the first unique region; In the second determination step, the upper surface of the powder layer of the (N+1)th layer or the upper surface of the modeling layer of the (N+1)th layer is divided into the plurality of partitioned regions in the same pattern as in the first determination step, and it is determined which of the partitioned regions includes the second unique region; In the checking step, when the divided area including the first unique area and the divided area including the second unique area are the same, it is determined that the shortest distance is shorter than the specified distance.

[0090] According to the above configuration 3), it is possible to determine whether the shortest distance between the first unique region and the second unique region is less than the prescribed distance without measuring the shortest distance, and therefore the matching step can be executed more easily.

[0091] 4) In some embodiments, the three-dimensional modeling method according to 3) above, In the first determination step, it is determined whether the first unique region is included in each of the plurality of partitioned regions constituting the upper surface of the Nth powder layer or the Nth modeling layer, In the second determination step, it is determined whether the second unique region is included in each of the plurality of partitioned regions constituting the upper surface of the (N+1)th powder layer or the (N+1)th modeling layer.

[0092] According to the above configuration 4), it is determined whether the first unique region and the second unique region are generated in each divided region, so that spatters that are likely to cause printing abnormalities can be detected more reliably.

[0093] 5) In some embodiments, the three-dimensional modeling method according to any one of 1) to 4) above, In the first determination step, it is determined whether the first unique region is included on the top surface of the Nth modeling layer.

[0094] According to the above configuration 5), spatters generated by irradiation of the Nth powder layer with a beam can be detected more reliably. This makes it possible to more reliably detect spatters that are likely to cause printing defects.

[0095] 6) In some embodiments, the three-dimensional modeling method according to 5) above, In the second determination step, it is determined whether the second unique region is included in the upper surface of the (N+1)th powder layer.

[0096] According to the above configuration 6), if the spatter generated in the Nth modeling layer remains after the (N+1)th powder laying step, the occurrence of the second unique region can be detected before the (N+1)th modeling layer forming step. This makes it possible to prevent the occurrence of unmelted parts in the modeling layer, which may occur when the (N+1)th powder layer is irradiated with a beam.

[0097] 7) In some embodiments, the three-dimensional modeling method according to 6) above, further comprising the steps of: In the second judgment step, if it is determined in the first judgment step that the upper surface of the Nth layer of the modeling layer does not include the first unique region, the determination of whether the upper surface of the N+1th layer of the powder layer is skipped.

[0098] According to the above configuration 7), if no sputtering occurs in the Nth modeling layer, detection of sputtering in the (N+1)th powder layer is not performed. This makes it possible to eliminate unnecessary detection processing of sputtering, thereby making it possible to detect abnormalities more efficiently.

[0099] 8) In some embodiments, the three-dimensional modeling method according to 5) above, In the second determination step, it is determined whether the second unique region is included on the upper surface of the modeling layer that is the (N+1)th layer.

[0100] According to the above configuration 8), the position of the first unique region in the Nth modeling layer can be compared with the position of the second unique region in the N+1th modeling layer in the collation step, thereby making it possible to more accurately compare the positions of the first unique region and the second unique region.

[0101] 9) In some embodiments, the three-dimensional modeling method according to any one of 1) to 4) above, In the first determination step, it is determined whether the first unique region is included in the upper surface of the Nth powder layer, In the second determination step, it is determined whether the second unique region is included in the upper surface of the (N+1)th powder layer.

[0102] According to the above configuration 9), the position of the first unique region in the Nth powder layer and the position of the second unique region in the (N+1)th powder layer can be compared in the collation step, thereby making it possible to more accurately compare the positions of the first and second unique regions.

[0103] 10) A three-dimensional printing apparatus according to at least one embodiment of the present disclosure, a powder feeder (3) configured to move horizontally and configured to feed powder; an irradiation device (5) configured to move horizontally and configured to irradiate a beam; an additive manufacturing control unit (88) including a powder laying control unit (87) for controlling the powder supplying device so as to lay the powder, and a modeling layer formation control unit (88) for controlling the irradiation device so as to form a modeling layer by irradiating a beam onto the laid powder layer (10); Equipped with A three-dimensional printing apparatus in which the process by the additive manufacturing control unit is repeatedly executed, A height sensor (7) for detecting the height of a measurement object; a first determination control unit (91) for determining, based on a detection result of the height sensor, whether an upper surface of the Nth powder layer (powder layer upper surface 11) or an upper surface of the Nth modeling layer (modeling layer upper surface 22) (where N is a natural number) includes a first unique region (51) whose height exceeds a first tolerance; a second determination control unit (92) for determining, based on the detection result of the height sensor, whether the upper surface of the powder layer (powder layer upper surface 11) of the (N+1)th layer or the upper surface of the modeling layer (modeling layer upper surface 22) of the (N+1)th layer includes a second unique region (52) whose height exceeds a second tolerance; an abnormality determination control unit (93) that determines that an abnormality exists when the first determination control unit determines that the first unique region is included in the upper surface and the second determination control unit determines that the second unique region is included in the upper surface; and Equipped with.

[0104] According to the configuration 10) above, the same technical advantages as those in 1) above can be obtained. [Explanation of symbols]

[0105] 1: Three-dimensional printing equipment 3: Powder feeding device 5: Irradiation device 7: Height sensor 8: Base drive unit 9: Base plate 10: Powder layer 11: Top surface of powder layer 20: Modeling layer 22:Top surface of modeling layer 51: 1st singular region 52:Second singular region 57 : Partition area 86: Base control section 87: Powder laying control unit 88: Layer formation control unit 89: Additive manufacturing control unit 90: Controller 91: First judgment control unit 92: Second judgment control unit 93: Abnormality determination control unit 94: Matching section L: dashed line R: Dimension

Claims

1. A three-dimensional modeling method in which an additive manufacturing step including a powder laying step of laying powder and a modeling layer forming step of forming a modeling layer by irradiating a beam onto the laid powder layer is repeatedly performed, a first determination step of determining whether a first unique region having a height exceeding a first tolerance is included on an upper surface of the Nth powder layer or an upper surface of the Nth modeling layer (where N is a natural number); A second determination step of determining whether a second unique region whose height exceeds a second tolerance is included on the upper surface of the powder layer of the (N+1)th layer or on the upper surface of the modeling layer of the (N+1)th layer; an anomaly determination step of determining that an anomaly exists when it is determined in the first determination step that the first unique region is included in the upper surface and when it is determined in the second determination step that the second unique region is included in the upper surface; A three-dimensional modeling method comprising:

2. a comparison step of determining whether a shortest distance between the first unique region and the second unique region in a plan view is less than a specified distance when the first determination step determines that the first unique region is included in the upper surface and the second determination step determines that the second unique region is included in the upper surface, In the abnormality determination step, if it is determined that the shortest distance is shorter than the specified distance, it is determined that the abnormality exists. The three-dimensional modeling method according to claim 1 .

3. In the first determination step, the upper surface of the Nth powder layer or the upper surface of the Nth modeling layer is divided into a plurality of partitioned regions, and it is determined which of the partitioned regions includes the first unique region; In the second determination step, the upper surface of the powder layer of the (N+1)th layer or the upper surface of the modeling layer of the (N+1)th layer is divided into the plurality of partitioned regions in the same pattern as in the first determination step, and it is determined which of the partitioned regions includes the second unique region; In the comparison step, when the partitioned area including the first unique area and the partitioned area including the second unique area are the same, it is determined that the shortest distance is shorter than the specified distance. The three-dimensional modeling method according to claim 2 .

4. In the first determination step, it is determined whether the first unique region is included in each of the plurality of partitioned regions constituting the upper surface of the Nth powder layer or the Nth modeling layer, In the second determination step, it is determined whether the second unique region is included in each of the plurality of partitioned regions constituting the upper surface of the (N+1)th powder layer or the (N+1)th modeling layer. The three-dimensional modeling method according to claim 3 .

5. In the first determination step, it is determined whether the first unique region is included in the upper surface of the Nth modeling layer. The three-dimensional modeling method according to claim 1 .

6. In the second determination step, it is determined whether the second unique region is included in the upper surface of the (N+1)th powder layer. The three-dimensional modeling method according to claim 5 .

7. In the second determination step, when it is determined in the first determination step that the first unique region is not included in the upper surface of the N-th modeling layer, a determination as to whether the second unique region is included in the upper surface of the (N+1)-th powder layer is skipped. The three-dimensional modeling method according to claim 6.

8. In the second determination step, it is determined whether the second unique region is included on the upper surface of the (N+1)th modeling layer. The three-dimensional modeling method according to claim 5 .

9. In the first determination step, it is determined whether the first unique region is included in the upper surface of the Nth powder layer, In the second determination step, it is determined whether the second unique region is included in the upper surface of the (N+1)th powder layer. The three-dimensional modeling method according to claim 1 .

10. a powder feeder configured to move horizontally and configured to feed powder; an illumination device configured to move horizontally and configured to illuminate the beam; a powder laying control unit for controlling the powder supplying device so as to lay the powder, and a modeling layer formation control unit for controlling the irradiation device so as to form a modeling layer by irradiating a beam onto the laid powder layer; Equipped with A three-dimensional printing apparatus in which the process by the additive manufacturing control unit is repeatedly executed, A height sensor for detecting the height of a measurement object; a first determination control unit for determining whether a first unique region, the height of which exceeds a first tolerance, is included on an upper surface of the Nth powder layer or an upper surface of the Nth modeling layer (where N is a natural number) based on a detection result of the height sensor; a second determination control unit for determining whether a second unique region, the height of which exceeds a second tolerance, is included on the upper surface of the powder layer of the (N+1)th layer or on the upper surface of the modeling layer of the (N+1)th layer, based on the detection result of the height sensor; an abnormality determination control unit that determines that an abnormality exists when the first determination control unit determines that the first unique region is included in the upper surface and the second determination control unit determines that the second unique region is included in the upper surface; and A three-dimensional printing apparatus comprising:

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