阅读说明：本技术 三维形状造型物的制造方法 (Method for manufacturing three-dimensional shaped object ) 是由 中村晓史 吉田德雄 于 2019-01-30 设计创作，主要内容包括：本发明的一实施方式关于三维形状造型物的制造方法,通过(i)向粉末层的规定部位照射光束,使规定部位的粉末烧结或熔融固化而形成固化层的工序,以及(ii)在所得到的固化层之上形成新的粉末层,向新的粉末层的规定部位照射光束,形成进一步的固化层的工序,使粉末层及固化层交替地反复层叠,从而制造三维形状造型物。特别是,在本发明的一实施方式中,将固化层由相互重叠的多个固化部形成；在作为第1个形成的固化部的第1固化部的形成之后,至少向第1固化部的两主缘部分照射光束。(In one embodiment of the present invention, a three-dimensional shaped object is manufactured by (i) a step of forming a solidified layer by irradiating a predetermined portion of a powder layer with a light beam and sintering or melting and solidifying the powder at the predetermined portion, and (ii) a step of forming a new powder layer on the obtained solidified layer and irradiating a predetermined portion of the new powder layer with a light beam to form a further solidified layer, and alternately and repeatedly laminating the powder layer and the solidified layer. In particular, in one embodiment of the present invention, the cured layer is formed of a plurality of cured portions that are overlapped with each other; after the formation of the 1 st cured part, which is the 1 st formed cured part, light beams are irradiated to at least both main edge portions of the 1 st cured part.)

1. A method for producing a three-dimensional shaped object by

(i) A step of irradiating a predetermined portion of the powder layer with a light beam to sinter or melt-solidify the powder at the predetermined portion to form a solidified layer, and

(ii) a step of forming a new powder layer on the solidified layer obtained, and irradiating a predetermined portion of the new powder layer with a light beam to form a further solidified layer,

alternately and repeatedly laminating the powder layers and the solidified layers to produce a three-dimensional shaped object;

the method for producing a three-dimensional shaped object is characterized in that,

forming the cured layer from a plurality of cured portions that are overlapped with each other;

after the 1 st cured part which is the 1 st formed cured part is formed, the light beam is irradiated to at least both main edge portions of the 1 st cured part.

2. The method of manufacturing a three-dimensional shaped object according to claim 1,

after the formation of the 1 st cured part, the irradiation with the light beam is performed so that the irradiation region of the light beam passes through at least the two main edge portions of the 1 st cured part.

3. The method of manufacturing a three-dimensional shaped object according to claim 1 or 2,

after the formation of the 1 st solidified portion, the irradiation of the light beam is performed so as to melt at least the two main edge portions of the 1 st solidified portion.

4. A method of producing a three-dimensional shaped object according to any one of claims 1 to 3,

after the formation of the 1 st cured portion, the irradiation with the light beam is performed so as to straddle at least the two main edge portions of the 1 st cured portion and the non-irradiated portions of the light beam adjacent to the two main edge portions, respectively.

5. The method of manufacturing a three-dimensional shaped object according to claim 4,

after the formation of the 1 st cured portion, the light beam is irradiated to a region spanning the two main edge portions of the 1 st cured portion and the non-irradiated portions adjacent to the two main edge portions, whereby a 2 nd cured portion and a 3 rd cured portion overlapping with the 1 st cured portion are formed on both sides of the 1 st cured portion.

6. The method of producing a three-dimensional shaped object according to any one of claims 1 to 5,

the energy density of the light beam irradiated to at least the two main edge portions of the 1 st cured part after the formation of the 1 st cured part is smaller than the energy density of the light beam used in the formation of the 1 st cured part.

7. The method of producing a three-dimensional shaped object according to any one of claims 1 to 6,

the beam diameter of the light beam irradiated to at least the both main edge portions of the 1 st cured part after the formation of the 1 st cured part is larger than the beam diameter of the light beam used in the formation of the 1 st cured part.

8. The method of producing a three-dimensional shaped object according to any one of claims 1 to 7,

and irradiating the light beam to at least two main edge portions of the 1 st cured portion after the 1 st cured portion is formed.

9. The method of producing a three-dimensional shaped object according to any one of claims 1 to 8,

the irradiation with the light beam is performed such that the two irradiation regions pass through at least the two main edge portions of the 1 st curing section, respectively.

10. The method of manufacturing a three-dimensional shaped object according to claim 9,

the two irradiation regions are made to pass through at least the two main edge portions of the 1 st curing part in parallel in terms of time.

11. The method of manufacturing a three-dimensional shaped object according to claim 9 or 10,

a scanning center line of the light beam irradiated to one main edge portion of the 1 st cured portion after the formation of the 1 st cured portion is positioned closer to a virtual contour, which is a contour of the cured layer, than a scanning center line of the light beam used in the formation of the 1 st cured portion, with the virtual contour as a base point.

12. The method of producing a three-dimensional shaped object according to any one of claims 1 to 8,

after the formation of the 1 st cured portion, the irradiation with the light beam is performed such that 1 irradiation region passes through both main edge portions of the 1 st cured portion at least along the axial direction of the 1 st cured portion.

13. The method of manufacturing a three-dimensional shaped object according to claim 12,

the irradiation with the light beam is performed such that the 1 irradiation region alternately passes through one of the two main edge portions and the other of the two main edge portions of the 1 st curing section.

14. The method of manufacturing a three-dimensional shaped object according to claim 12 or 13,

as the light beam forming the 1 shot region, a light beam having a higher energy density on both sides of a scanning center line than on the scanning center line is used.

15. The method for producing a three-dimensional shaped object according to any one of claims 1 to 14, wherein the step of forming the three-dimensional shaped object,

the position of the irradiation region of the light beam used for forming the 1 st cured part is shifted for each cured layer.

16. The method of producing a three-dimensional shaped object according to any one of claims 1 to 15,

the 1 st curing section is formed by irradiation of the light beam along a 1 st scanning path, and both side portions of the irradiated region adjacent to the irradiated region formed by the irradiation of the light beam are non-irradiated portions of the light beam.

17. The method of manufacturing a three-dimensional shaped object according to claim 3,

the 1 st solidified portion obtained by melting and solidifying at least the two main edge portions of the 1 st solidified portion is located below a lower end of a horizontally movable pressing blade used for forming the powder layer later.

Technical Field

The present invention relates to a method for producing a three-dimensional shaped object. More specifically, the present invention relates to a method for manufacturing a three-dimensional shaped object in which a solidified layer is formed by irradiating a powder layer with a light beam.

Background

A method of producing a three-dimensional shaped object by irradiating a powder material with a light beam (generally referred to as a "powder bed fusion bonding method") has been known. This method is based on the following steps (i) and (ii) and alternately repeats the powder layer formation and the solidified layer formation to produce a three-dimensional shaped object.

(i) And a step of irradiating a predetermined portion of the powder layer with a light beam to sinter or melt-solidify the powder at the predetermined portion to form a solidified layer.

(ii) And forming a new powder layer on the solidified layer, and irradiating the powder layer with a light beam to form a further solidified layer.

By following such a manufacturing technique, a complex three-dimensional shaped object can be manufactured in a short time. When an inorganic metal powder is used as the powder material, the three-dimensional shaped object obtained can be used as a mold. On the other hand, when an organic resin powder is used as the powder material, the three-dimensional shaped object obtained can be used as various models.

The case where metal powder is used as the powder material and the three-dimensional shaped object obtained by the use is used as the metal mold is exemplified. As shown in fig. 13, first, the pressing blade 23 is operated to form a powder layer 22 having a predetermined thickness on the shaping plate 21 (see fig. 13 (a)). Next, a predetermined portion of the powder layer 22 is irradiated with the light beam L to form a solidified layer 24 from the powder layer 22 (see fig. 13 (b)). Next, a new powder layer is formed on the solidified layer obtained, and a new solidified layer is formed by irradiating the powder layer with the light beam again. By alternately repeating the powder layer formation and the solidified layer formation in this way, the solidified layers 24 are stacked (see fig. 13 c), and finally, the three-dimensional shaped object formed of the stacked solidified layers 24 can be obtained. Since the solidified layer 24 formed as the lowermost layer is bonded to the mold plate 21, the three-dimensional shaped object and the mold plate 21 are integrated, and the integrated object can be used as a mold.

Disclosure of Invention

Problems to be solved by the invention

When a new powder layer 22 ' having a predetermined thickness is formed on a solidified layer 24 ' that has been formed, for example, by using a light beam, n (natural number of n: 1 or more) scanning paths 10 ' of light beams are irradiated in parallel in one direction (see fig. 16 a and 16 b) to a predetermined portion of the new powder layer 22 ' along each scanning path 10 '. Specifically, the (n-1) th solidified portion 24n-1 ' can be formed by irradiation of the light beam along the (n-1) th scanning path 10 ', and then the light beam is irradiated to a part of the solidified portion 24n-1 ' and the powder adjacent to the solidified portion 24n-1 ' along the (n) th scanning path 10 '. By irradiation with the light beam, a new cured layer composed of a plurality of cured portions overlapped with each other can be formed.

Here, the inventors of the present application have found that the following problems may occur when the scanning paths 10 ' of n light beams are irradiated with light beams along the respective scanning paths 10 ' so that the scanning paths 10 ' are arranged in parallel in one direction (see fig. 16 a and 16 b).

Specifically, it was found that: the height of the 1 st formed cured portion 24a 'obtained by the irradiation of the light beam along the 1 st scanning path 10' is relatively larger than the height of the 2 nd and later formed cured portions (for example, the 2 nd cured portion 24b ') obtained by the irradiation of the light beam along the 2 nd and later scanning paths 10'. This may occur for the following reason. Specifically, when the 1 st solidified portion 24a 'is formed, the portions on both sides of the irradiated region adjacent to the irradiated region of the light beam along the 1 st scanning path 10' are non-irradiated portions (powder existing portions) of the light beam. Therefore, the powder 19 'located at the both side portions may be drawn (attracted) toward the irradiation region side of the light beam along the 1 st scanning path 10' by the irradiation heat of the light beam. In contrast, when the light beam is irradiated along the 2 nd and subsequent scanning paths 10', there may be a cured portion that has just been formed on the side of the irradiation region adjacent to the irradiation region of the light beam. Therefore, the amount of powder drawn from one side to the irradiation region side of the light beam along the 2 nd scanning path 10' by the irradiation heat of the light beam is relatively smaller than the amount of powder drawn from the other side to the irradiation region side. Therefore, relatively more powder may be drawn toward the irradiation region side of the light beam along the scanning path 10 ' at the time of the light beam irradiation along the 1 st scanning path 10 ' than at the time of the light beam irradiation along the 2 nd and later scanning paths 10 '. For this reason, as described above, the height of the obtained 1 st cured portion 24a 'may be relatively larger than the height of the 2 nd or later formed cured portion (for example, the 2 nd cured portion 24 b').

If the height of the obtained 1 st solidified portion 24a 'is relatively larger than the height of the 2 nd solidified portion 24 b', there is a possibility that a horizontally movable pressing blade (squeezing blade)23 'used for forming a new powder layer to follow may come into contact with the 1 st solidified portion 24 a' (see fig. 16 (c)). Due to this contact, it may be difficult to properly form a subsequent new powder layer. As a result, it is difficult to appropriately form a new cured layer to be subsequently formed, and eventually, it may be difficult to appropriately produce a three-dimensional shaped object composed of stacked cured layers. That is, there is a possibility that a three-dimensional shaped object with high accuracy cannot be finally obtained.

The present invention has been made in view of such circumstances. That is, an object of the present invention is to provide a method for producing a three-dimensional shaped object, the method comprising: the height of the 1 st solidified portion, which is the 1 st solidified portion formed after the formation of the predetermined powder layer, can be further reduced.

Means for solving the problems

In order to achieve the above object, one embodiment of the present invention provides a method for manufacturing a three-dimensional shaped object, in which a three-dimensional shaped object is manufactured by alternately repeating the stacking of powder layers and solidified layers, by (i) a step of irradiating a predetermined portion of the powder layer with a light beam to sinter or melt-solidify the powder at the predetermined portion to form a solidified layer, and (ii) a step of forming a new powder layer on the obtained solidified layer, and irradiating a predetermined portion of the new powder layer with a light beam to form a next solidified layer; forming a cured layer with a plurality of cured portions overlapped with each other; after a 1 st cured part, which is the 1 st formed cured part, is formed, light beams are irradiated to at least both main edge portions of the 1 st cured part.

Effects of the invention

According to the manufacturing method of the present invention, the height of the 1 st solidified portion, which is the 1 st solidified portion formed after the formation of the predetermined powder layer, can be further reduced.

Drawings

Fig. 1 is a sectional view schematically showing the technical idea of the present invention.

Fig. 2 is a cross-sectional view schematically showing the irradiation pattern 1 (pattern of passing through two irradiation regions) of the present invention.

Fig. 3 is a plan view schematically showing the 1 st irradiation mode (mode of passing through two irradiation regions) of the present invention.

Fig. 4 is a cross-sectional view schematically showing a cured portion formed according to a conventional irradiation pattern and a cured portion formed according to the 1 st irradiation pattern of the present invention.

Fig. 5 is a plan view schematically showing a cured part formed according to a conventional irradiation pattern and a cured part formed according to the 1 st irradiation pattern of the present invention.

Fig. 6 is a plan view schematically showing a form of using light beams having different energy densities.

Fig. 7 is a plan view schematically showing the 2 nd irradiation pattern (pattern passing through 1 irradiation region) of the present invention.

Fig. 8 is a plan view schematically showing a more preferable 2 nd irradiation mode of the present invention.

Fig. 9 is a plan view schematically showing a more preferable 2 nd irradiation mode of the present invention.

Fig. 10 is a plan view schematically showing a mode in which the 1 st solidified portion is formed with a virtual contour as a base point of the contour of the solidified layer.

Fig. 11 is a cross-sectional photograph view corresponding to comparative example and example.

Fig. 12 is a photograph plan view corresponding to comparative example and example.

FIG. 13 is a cross-sectional view schematically showing a process form of the stereolithography combined machining by the powder bed fusion bonding method (FIG. 13 (a): when the powder layer is formed, (FIG. 13 (b): when the cured layer is formed, and FIG. 13 (c): in the middle of lamination).

Fig. 14 is a perspective view schematically showing the structure of the stereolithography compound processing machine.

Fig. 15 is a flowchart showing a normal operation of the hybrid stereolithography machine.

Fig. 16 is a schematic diagram showing a technical problem of the present application (fig. 16 a: a form (plane) in which a light beam is irradiated along each scanning path, fig. 16 b: a form (cross-section) in which a light beam is irradiated along each scanning path, and fig. 16 c: a form (cross-section) in which a new powder layer is formed using a pressing blade.

Detailed Description

Hereinafter, an embodiment of the present invention will be described in more detail with reference to the drawings. The form and size of each element in the drawings are merely exemplary, and do not reflect the actual form and size.

The term "powder layer" as used herein refers to, for example, "a metal powder layer made of a metal powder" or "a resin powder layer made of a resin powder". The "predetermined portion of the powder layer" is substantially a region of the three-dimensional shaped object to be manufactured. Therefore, by irradiating the powder existing at the predetermined portion with a light beam, the powder is sintered or melted and solidified to form a three-dimensional shaped object. The "solidified layer" is referred to as a "sintered layer" when the powder layer is a metal powder layer, and is referred to as a "hardened layer" when the powder layer is a resin powder layer.

In addition, the "up-down" direction directly or indirectly described in the present specification is, for example, a direction based on the positional relationship between the mold plate and the three-dimensional shaped object, and the side where the three-dimensional shaped object is produced is referred to as "upper" and the opposite side is referred to as "lower" with respect to the mold plate.

[ powder bed fusion bonding method ]

First, a powder bed fusion bonding method which is a premise of the production method of the present invention will be described. In particular, the powder bed fusion bonding method is exemplified by a stereolithography combined process in which a three-dimensional shaped object is additionally cut. Fig. 13 schematically shows a process form of the combined optical modeling machine, and fig. 14 and 15 are flowcharts showing a main configuration and operation of the combined optical modeling machine that can perform the powder bed fusion bonding method and the cutting process, respectively.

As shown in fig. 14, the hybrid optical molding machine 1 includes a powder layer forming mechanism 2, a beam irradiation mechanism 3, and a cutting mechanism 4.

The powder layer forming means 2 is a means for forming a powder layer by spreading powder such as metal powder or resin powder at a predetermined thickness. The beam irradiation mechanism 3 is a mechanism for irradiating a predetermined portion of the powder layer with the beam L. The cutting mechanism 4 is a mechanism for cutting the surface of the stacked cured layers, that is, the surface of the three-dimensional shaped object.

As shown in fig. 13, the powder layer forming means 2 mainly includes a powder table 25, a pressing blade 23, a shaping table 20, and a shaping plate 21. The powder table 25 is a table that can be moved up and down in a powder material box 28 surrounded on the outer periphery by a wall 26. The pressing blade 23 is a blade that can move in the horizontal direction to supply the powder 19 on the powder table 25 onto the shaping table 20 to obtain the powder layer 22. The molding table 20 is a table that can be moved up and down in a molding box 29 surrounded on its outer periphery by a wall 27. The shaping plate 21 is disposed on the shaping table 20 and serves as a base for the three-dimensional shaped object.

As shown in fig. 14, the beam irradiation mechanism 3 mainly includes a beam oscillator 30 and a galvanometer mirror 31. The beam oscillator 30 is a device that emits the light beam L. The galvanometer mirror 31 is a mechanism for scanning the emitted light beam L toward the powder layer 22, that is, a scanning mechanism of the light beam L.

As shown in fig. 14, the cutting mechanism 4 mainly includes an end mill 40 and a drive mechanism 41. The end mill 40 is a cutting tool for cutting the surface of the stacked solidified layers, that is, the surface of the three-dimensional shaped object. The drive mechanism 41 is a mechanism for moving the end mill 40 to a desired cutting site.

The operation of the stereolithography compound processing machine 1 will be described in detail. As shown in the flowchart of fig. 15, the operation of the hybrid optical molding machine 1 includes a powder layer forming step (S1), a solidified layer forming step (S2), and a cutting step (S3). The powder layer forming step (S1) is a step for forming the powder layer 22. In the powder layer forming step (S1), the molding table 20 is first lowered by Δ t (S11) so that the level difference between the upper surface of the molding plate 21 and the upper end surface of the molding box 29 becomes Δ t. Next, after raising the powder table 25 by Δ t, the pressing blade 23 is moved in the horizontal direction from the powder material box 28 toward the molding box 29 as shown in fig. 13 (a). This allows the powder 19 disposed on the powder table 25 to be transferred onto the shaping plate 21 (S12), and the powder layer 22 to be formed (S13). Examples of the powder material for forming the powder layer 22 include "metal powder having an average particle diameter of about 5 to 100 μm" and "resin powder such as nylon, polypropylene, or ABS having an average particle diameter of about 30 to 100 μm". After the powder layer 22 is formed, the process proceeds to a solidified layer forming step (S2). The solidified layer forming step (S2) is a step of forming the solidified layer 24 by light beam irradiation. In the solidified layer forming step (S2), the light beam L is emitted from the light beam oscillator 30 (S21), and the light beam L is scanned by the galvanometer mirror 31 toward a predetermined position on the powder layer 22 (S22). Thereby, the powder at the predetermined portion of the powder layer 22 is sintered or melted and solidified, and the solidified layer 24 is formed as shown in fig. 13 (b) (S23). As the light beam L, a carbonic acid gas beam, Nd: YAG beam, fiber beam, or ultraviolet ray.

The powder layer forming step (S1) and the solidified layer forming step (S2) are alternately repeated. Thereby, as shown in fig. 13 (c), a plurality of cured layers 24 are laminated.

If the laminated cured layer 24 reaches a prescribed thickness (S24), the process proceeds to the cutting step (S3). The cutting step (S3) is a step for cutting the surface of the stacked cured layers 24, that is, the surface of the three-dimensional shaped object. The end mill 40 is driven (see fig. 13 c and 14) to start the cutting step (S31). For example, when the end mill 40 has an effective cutting edge length of 3mm, since the cutting process of 3mm can be performed along the height direction of the three-dimensional shaped object, if Δ t is 0.05mm, the end mill 40 is driven at the time when 60 solidified layers 24 are stacked. Specifically, the surface of the stacked solidified layers 24 is subjected to cutting treatment while the end mill 40 is moved by the drive mechanism 41 (S32). At the end of the cutting step (S3), it is determined whether or not a desired three-dimensional shaped object is obtained (S33). If the desired three-dimensional shaped object is not obtained yet, the process returns to the powder layer forming step (S1). Thereafter, the powder layer forming step (S1) to the cutting step (S3) are repeated to perform the subsequent stacking and cutting processes of the solidified layers, whereby a desired three-dimensional shaped object can be finally obtained.

[ production method of the present invention ]

The manufacturing method according to an embodiment of the present invention is characterized in the above-described powder bed fusion bonding method in the form of irradiation with a light beam to a predetermined portion of a powder layer.

(technical idea of the invention)

As described above, the inventors of the present application have newly found that the following problems occur when light beams are irradiated along the respective scanning paths 10 'so that the scanning paths 10' of the light beams are arranged in parallel in one direction (see fig. 16 (a) and 16 (b)). Specifically, the height of the 1 st cured part 24a 'as the 1 st formed cured part may become relatively larger than the 2 nd and later formed cured part (for example, the 2 nd cured part 24 b'). Therefore, the inventors of the present application have conducted special studies on a technical solution for further reducing the height of the 1 st cured part 24 a'.

As a result, the problem has been solved by a method that has not been generally implemented by the technical common knowledge of those skilled in the art so far (that is, by irradiating the light beams along the respective scanning paths so that the scanning paths of the light beams are arranged in parallel in one direction). Specifically, the invention of the present applicationThe inventors have made the present invention having the following technical ideas: in the 1 st cured part 24a as the 1 st formed cured part₁After formation, at least the first cured portion 24a is formed₁The two main edge portions X, Y irradiate the light beam L (refer to the left side portion of fig. 1). According to the technical idea of the present invention, at least the 1 st cured part 24a₁Is illuminated by the light beam L at the two main edge portions X, Y. I.e., at least the 1 st cured part 24a₁Both the one main edge portion X and the other main edge portion Y are irradiated with the light beam L.

In this regard, as described above, according to the common technical knowledge of those skilled in the art, in view of the scanning efficiency and the use efficiency of the light beam, the light beam is generally irradiated along each scanning path so that the scanning paths of the light beam are arranged in parallel in one direction. That is, a plurality of scanning paths of the light beam are generally arranged in parallel in one direction. In contrast, according to the technical idea of the present invention, unlike the conventional technical common sense of those skilled in the art, the 1 st cured portion 24a is formed once (once)₁Thereafter, except for the temporarily formed 1 st cured portion 24a₁The "other main edge portion Y located on the opposite side of the main edge portion X" is also irradiated with the "active" light beam L "in addition to the one main edge portion X. That is, in the present invention, as a result of focusing on the "initiative" to further reduce the height of the 1 st cured part 24 a', the "first cured part 24 a" is moved to₁The other main edge portion Y is also irradiated with the light beam L ″. This is the largest feature of the present invention that is not present in the technical common sense of the skilled person up to now.

The term "main edge portion" as used herein refers to an edge portion on the long side of a cured portion (e.g., the 1 st cured portion) extending in the axial direction in a broad sense. The term "main edge portion" as used herein refers to a portion extending from the linear contour on the long side of the temporarily formed cured portion (e.g., the 1 st cured portion) to the inside corresponding to the "predetermined length". The predetermined length is not particularly limited, and is about 3% to about 30%, preferably about 6% to about 20%, for example about 10% of the width of the bottom of the first cured portion 1 once formed. That is, it should be noted that the "main edge portion" described in the present specification cannot be regarded as the same as the linear contour on the long side of the 1 st cured portion. In addition, the phrase "irradiating light beams to at least both main edge portions of the 1 st curing part after the 1 st curing part is formed" as used herein means that after irradiating light beams to at least one main edge portion of the 1 st curing part subsequent to the 1 st curing part being formed once, light beams are also irradiated to at least the other main edge portion of the 1 st curing part. That is, in the present specification, the case where the light beam is irradiated along each scanning path (after … is formed such as the 4 th curing part, the 5 th curing part, the 6 th curing part, and the like) so that the scanning paths of the light beam are arranged in parallel in one direction and the light beam is irradiated to the other main edge portion of the 1 st curing part may be included. The "scanning path of the light beam" described in the present specification refers to a moving path of the light beam. The "scanning path of the light beam" described in the present specification refers to a moving path of the light beam.

In the 1 st cured part 24a₁After the temporary formation, at least toward the 1 st cured part 24a₁When the light beam L is irradiated to both main edge portions X, Y, the irradiation region 50 of the light beam L passes through at least the 1 st curing part 24a by the movement of the light beam L along the scanning path₁And two main edge portions X, Y (see left side of fig. 1). The "irradiation region of the light beam" described in the present specification refers to a region where the light beam moving along the scanning path has a width for irradiating a predetermined portion (main edge portion or the like) of the curing portion. That is, the 1 st cured part 24a is appropriately included in the irradiation region 50 of the light beam L in a plan view₁And two main edge portions X, Y. Therefore, the irradiation heat of the light beam L is appropriately supplied to the both main edge portions X, Y in the temporarily solidified state, and thereby the both main edge portions X, Y can be changed from the solidified state to the molten state. Here, the 1 st cured part 24a₁It can be formed by drawing the powder located at both side portions of the irradiation area of the light beam along the 1 st scanning path toward the irradiation area side of the light beam along the scanning path. Therefore, the 1 st cured part 24a is drawn from both sides₁In cross section, it may be a ridge portion having an inclined surface. Therefore, in the twoIn the case where the main edge portion X, Y changes from the solidified state to the molten state, the molten main edge portions X, Y have fluidity, and the 1 st solidified portion 24a is added₁Having an inclined cross section, at least a part of the two melted main edge portions X, Y can flow in the outward direction in the cross section (refer to the right side portion of fig. 1). Specifically, the melted portions of the two main edge portions X, Y can flow to be located at the 1 st solidified part 24a in cross section₁The non-irradiated portion of the outer beam is spread in the direction of supply.

By the outward flowing operation of the melted portion of the both main edge portions X, Y, the 1 st solidified portion 24a before the both main edge portions X, Y are irradiated with the light beam L₁In contrast, the 1 st cured portion 24a obtained by irradiating both main edge portions X, Y with the light beam L and then re-curing the light beam L can be obtained₂Is further reduced, in particular the top height. That is, the 1 st cured part 24a having a further reduced height can be formed₂(refer to the right side of fig. 1). If the 1 st cured part 24a is formed to be further reduced in height₂The obtained 1 st cured part 24a can be formed₂Is located below the lower end of the horizontally movable pressing blade used in the formation of the subsequent powder layer. Therefore, it is possible to appropriately avoid the horizontally movable pressing blade used in the formation of the subsequent new powder layer from coming into contact with the 1 st solidified part 24a₂. Therefore, a subsequent new powder layer can be appropriately formed, and as a result, a subsequent new solidified layer can be appropriately formed. Therefore, a three-dimensional shaped object with high accuracy can be obtained appropriately in the end.

As the 1 st cured part 24a to be applied after the 1 st cured part is once formed₁The irradiation pattern of the irradiation beam L at the both main edge portions X, Y can be roughly divided into two irradiation patterns.

(1 st irradiation mode)

First, the 1 st irradiation mode is performed at least across the 1 st cured part 24a₁The two main edge portions X, Y and the non-irradiated portion of the light beam adjacent to the two main edge portions X, Y, respectively, are irradiated with the light beam (see fig. 2 and 3).

In the 1 st irradiation mode, the light is directed to the 1 st cured part 24a₁And the portions of the non-irradiated portion 60 of the light beam respectively adjacent to the two main edge portions X, Y and X, Y irradiate the light beam L. Specifically, in the 1 st irradiation mode, the radiation is directed to the 1 st cured part 24a₁The one leading edge portion X and the portion of the non-irradiated portion 60 of the light flux adjacent to the one leading edge portion X are irradiated with the light flux L. In addition, the first cured part 24a is extended over the 1 st cured part₁And the other main edge portion Y and the portion of the non-irradiated portion 60 of the light beam adjacent to the other main edge portion Y are irradiated with the light beam L.

More specifically, the 1 st solidified portion 24a is formed by passing the irradiation region 50 α of the light beam L through a predetermined portion of the powder layer along the scanning path 10₁. Then, in the 1 st cured part 24a₁After formation, the first cured part 24a is extended over the first cured part 1₁The light beam L is irradiated to the one main edge portion X and the portion of the non-irradiated portion 60X of the light beam adjacent to the one main edge portion X. Thus, by the movement of the light beam L along the scanning path, the irradiation region 50A of the light beam L₁Through the first curing part 24a₁The one main edge portion X and the non-irradiated portion 60X of the light beam L (see fig. 2). That is, the irradiation region 50A of the light beam L is formed₁Suitably contains a 1 st cured part 24a in plan view₁The one main edge portion X and the non-irradiated portion 60X of the light beam L. Therefore, the irradiation heat of the light beam L is appropriately supplied to the one main edge portion X in the temporary solidified state and the powder 19 located at the non-irradiated portion 60. Thereby, both the main edge portion X in the temporarily solidified state and the powder 19 located in the non-irradiated portion 60X can be in the molten state.

When the one main edge portion X in the solidified state changes to the molten state, the molten one main edge portion X has fluidity, and the 1 st solidified portion 24a is added₁Having an inclined cross section, at least a part of the melted one main edge portion X may flow in an outward direction in the cross section. If the molten portion of one of the main edge portions X moves in the outward direction, at least a part of the molten portion of the one of the main edge portions X after the movement in the outward direction and the molten portion of the other main edge portion X that is not positioned in the outward direction move in the outward directionThe melted portions of the powder 19 of the irradiated portion 60X may be in a mutually mixed state.

In addition, in the 1 st cured part 24a₁After formation, the first cured part 24a is extended over the first cured part 1₁When the other main edge portion Y and the portion of the non-irradiated portion 60Y of the light flux adjacent to the other main edge portion Y are irradiated with the light flux L, the irradiation region 50A of the light flux L is moved along the scanning path by the light flux L₂Through the first curing part 24a₁The other main edge portion Y and the non-irradiated portion 60Y of the light beam L (see fig. 2 and 3). That is, in the irradiation region 50A of the light beam L₂In plan view, the first cured portion 24a is appropriately included₁The other main edge portion Y and the non-irradiated portion 60Y of the light beam L. Therefore, the irradiation heat of the light beam L is appropriately supplied to the other main edge portion Y in the temporarily solidified state and the powder 19 located in the non-irradiated portion 60Y. Thereby, both the other main edge portion Y in the temporarily solidified state and the powder 19 located in the non-irradiated portion 60Y can be in the molten state.

When the other main edge portion Y in the solidified state changes to the molten state, the other molten main edge portion Y has fluidity, and the 1 st solidified portion 24a is added₁Has an inclined cross section, and at least a part of the other main edge portion Y of the molten material can flow in the outer direction in the cross section. Further, if the other melted portion of the main edge portion Y moves outward, at least a part of the other melted portion of the main edge portion Y and the melted portion of the powder 19 located in the non-irradiated portion 60Y after moving outward can be mixed with each other.

In a configuration that follows the conventional technical common knowledge of those skilled in the art (i.e., a configuration in which the scanning paths of the light beams are arranged in parallel in one direction), the irradiation region 50 'of the light beam passes through only one main edge portion X' side of the temporarily formed 1 st cured portion. Therefore, in the first solidified portion 1 once formed, at least a part of the one main edge portion which is to be melted flows in the outer direction. In contrast, as described above, in the present embodiment, the 1 st cure is formed onceIn part, the two main edge portions X, Y are "actively" irradiated with a light beam, unlike conventional technical common knowledge of those skilled in the art. This allows the molten portion of the other main edge portion Y to flow in the outer direction in addition to the molten portion of the one main edge portion X. Therefore, in this embodiment, compared to the height of the 1 st solidified part 24 a' obtained in the conventional embodiment (see the left part of fig. 4 and the left part of fig. 5), the molten portion of the other main edge portion Y also flows in the outward direction, so that the 1 st solidified part 24a re-solidified after irradiation with the light beam L can be further reduced in size₂Height (see right side of fig. 4 and right side of fig. 5).

Further, in the present embodiment, as described above, at least a part of the melted portions of the both main edge portions X, Y moved in the outward direction and the melted portions of the powder 19 located in the non-irradiated portions 60X and 60Y of the light beam adjacent to the both main edge portions X, Y can be mixed. Therefore, if the mixed molten portion is cooled and solidified thereafter, the 2 nd solidified portion 24b and the 3 rd solidified portion 24c overlapping the 1 st solidified portion can be formed on both sides of the 1 st solidified portion having the "reduced height". In this regard, in a conventional mode following the technical common knowledge of those skilled in the art, the light beams are irradiated so that the scanning paths are arranged in one direction. Therefore, according to the conventional technical common knowledge of those skilled in the art, the 2 nd cured part 24b ' is formed to be overlapped on the side of the 1 st cured part 24a ' having a "relatively high height, and then the 3 rd cured part is formed to be overlapped on the side of the 2 nd cured part 24b '.

In contrast, in the present embodiment, the 2 nd cured portion 24b is not overlapped on the 3 rd cured portion 24c, and the 2 nd cured portion 24b and the 3 rd cured portion 24c are located at portions opposed to each other across the 1 st cured portion 24 a. That is, in the present embodiment, a light beam is irradiated to the other main edge portion side of the 1 st cured portion 24a in order to form the 3 rd cured portion 24 c. In view of the technical common knowledge of those skilled in the art, this irradiation pattern means that the light beam cannot be irradiated so that the scanning paths are arranged in the "one direction". If the light beams cannot be irradiated so that the scanning paths are arranged in parallel in one direction, there is a possibility that the scanning efficiency/use efficiency of the light beams is lowered. Therefore, although the scanning efficiency and the use efficiency of the light beam are reduced, the form in which the 2 nd cured part 24b and the 3 rd cured part 24c are positioned so as to face each other with the 1 st cured part 24a interposed therebetween can be said to be a very special form from the technical common knowledge of those skilled in the art. In this respect, this embodiment also has a technical feature.

The 1 st cured part 24a is performed with the virtual contour 24 α as the contour of the cured layer as the base point₁In the case of (2), the following configuration is preferably adopted (see fig. 10). The "virtual contour as the contour of the solidified layer" described in the present specification substantially refers to a portion corresponding to the contour of the solidified layer formed later, out of predetermined portions of the powder layer on which the light beam is irradiated. Specifically, it is preferable that the first cured portion 24a is formed in the 1 st cured portion 24a₁Scanning center line l of light beam used in formation₁In contrast, the first cured part 24a is formed₁Forming a backward 1 st cured part 24a₁The scanning center line l of the light beam irradiated to one main edge portion of the first and second substrates₂Located proximally relative to the imaginary profile 24 α, in other words, the 1 st cured portion 24a located proximally relative to the imaginary profile 24 α₁The scanning center line l of the light beam irradiated to one main edge portion of the first and second substrates₂Located in the 1 st cured part 24a₁Scanning center line l of light beam used in formation₁This makes it possible to reduce the height of the 1 st cured part, which may be relatively high in the height of the ridge, even when the contour portion of the cured layer is formed, and thus to avoid the height of the contour portion of the cured layer from becoming larger than the height of the other portions than the contour portion.

In addition, in this embodiment, two irradiation regions 50A are provided₁、50A₂Respectively pass through at least the 1 st cured part 24a₁Respectively, of the two main edge portions X, Y. In this case, two irradiation regions 50A may be made₁、50A₂At least the first 1 solidification part 24a₁Respectively (see fig. 3) of the two main edge portions X, Y.

Here, two irradiation regions 50A are used₁、50A₂In the case of (1), the two are sequentially passed through the first curing part 24a₁The two main edge portions of (2) are more often the case. However, the present invention is not limited to this, and the two irradiation regions 50A may be arranged as described above₁、50A₂Are traversed in parallel in time. In this case, at least the 1 st cured part 24a₁Can be irradiated by two irradiation regions 50A at substantially the same timing in time₁、50A₂And (4) irradiating. Thereby, the other irradiation region 50A can be set₂Timing of passing the other main edge portion Y and one irradiation region 50A₁The interval in time with respect to the crossing timing of the leading edge portion X on one side is eliminated. Therefore, the irradiation region 50A of the "other side" can be set₂The melting timing of the one main edge portion X relative to the one main edge portion Y when passing through the one main edge portion and the irradiation region 50A of the one main edge portion₁The difference in melting timing relative to the passage of the main edge portion X is reduced or eliminated. This makes it possible to substantially equalize the flow timing of the molten portion of one main edge portion X in the outward direction with the flow timing of the molten portion of the other main edge portion Y in the outward direction. Therefore, since the flow timing is substantially the same, the 1 st cured portion 24a obtained by re-curing after irradiation with the light beam L can be obtained₂Is further reduced.

In one embodiment, the first cured portion 24a is formed in the 1 st cured portion 24a₁After the temporary formation, at least to the 1 st cured part 24a₁The energy density of the light beam L irradiated from the both main edge portions X, Y is preferably higher than that of the 1 st cured portion 24a₁The energy density of the light beam L used for formation is small (see fig. 2 and 6).

As described above, the height of the obtained 1 st cured portion 24a 'may be relatively larger than the height of the 2 nd or later-formed cured portion (for example, the 2 nd cured portion 24 b') (see fig. 16). This is because, when the light beam is irradiated along the 1 st scanning path 10', relatively more powder may be directed along the scanning path than when the light beam is irradiated along the 2 nd and subsequent scanning paths 10The irradiation region side of the beam having the diameter 10' is narrowed. Therefore, the temporarily formed 1 st cured portion 24a is further reduced₁From the viewpoint of the height of (1 st solidified portion 24 a), it is preferable to melt more appropriately the powder that can be relatively more drawn toward the irradiation region 50 α side of the light beam along the 1 st scanning path 10, thereby improving the wettability of the melted portion with respect to the underlying base portion (solidified layer or the like)₁The energy density of the light beam L used in the formation is preferably relatively large.

On the other hand, if a plurality of light beams L having a large energy density are used to form the respective solidified portions that overlap each other, it is easy to appropriately melt the powder that can be drawn toward the irradiation regions of the respective light beams, and on the other hand, since the melting level is high, the shrinkage stress of the solidified layer composed of the respective solidified portions relatively easily increases when changing from the molten state to the solidified state. Therefore, warpage of the three-dimensional shaped object to be finally obtained may occur. Because of the above, it is preferable to suppress the use of the light beam L having a large energy density as much as possible. From this viewpoint, it is preferable to use the light beam L having a large energy density only at the time of formation of the 1 st cured part 24a having a height level "larger" than the height of the cured part formed at the 2 nd and later.

In contrast, when the 2 nd or later cured portion is formed, it is preferable to use the light beam L having a relatively smaller energy density than the light beam L used when the 1 st cured portion 24a is formed. As described above, in the present invention, the 2 nd and subsequent cured portions, that is, the 2 nd cured portion 24b and the 3 rd cured portion 24c are formed by irradiating the both main edge portions X, Y in the temporarily cured state and the non-irradiated portions 60X and 60Y adjacent to the both main edge portions X, Y with the light beams. Thus, in view of the above, it is preferable to use light beams having a relatively small energy density for both the main edge portions X, Y in the temporary cured state and the non-irradiated portions 60X, 60Y adjacent to both the main edge portions X, Y. That is, it is preferable to use a light beam having a relatively small energy density at least for the two main edge portions X, Y.

In the above description, it is described that the light beam L having a relatively smaller energy density than the light beam L used in the formation of the 1 st cured portion 24a is used in the formation of the 2 nd and subsequent cured portions. Thus, the magnitude relation between the energy density of the light beam L used for forming the 1 st cured portion 24a and the energy density of the light beam L used for forming the 2 nd or later cured portion is defined. That is, the energy density of the light beam L used for forming the 2 nd and subsequent cured portions is set to a normal level, while the energy density of the light beam L used for forming the 1 st cured portion is set to a value higher than the normal level. However, the magnitude relation of the energy density of the light beam L is not limited to the realization by only this mode. For example, a configuration may be adopted in which the energy density of the light beam L used for forming the 1 st cured part is set to a normal level, while the energy density of the light beam L used for forming the 2 nd cured part and the 3 rd cured part is set to a value lower than the energy density of the normal level. Thus, it is also possible to define a magnitude relationship between the energy density of the light beam L used in the formation of the 1 st cured part 24a and the energy density of the light beam L used in the formation of the 2 nd cured part (and the 3 rd cured part).

With the above, the 1 st cured portion 24a formed using the light beam L having a relatively large energy density can be temporarily formed₁Is itself reduced. Since the 1 st cured part 24a can be formed temporarily₁Is reduced by itself, so that the belt will be in the 1 st cured part 24a₁After the temporary formation, the 1 st cured portion 24a obtained by the irradiation of the light beams of the two main edge portions X, Y₂Is further reduced. On the other hand, in the formation of the 2 nd and subsequent cured portions, a beam having a relatively small energy density may be used. Therefore, the light beam having a relatively large energy density, which is a cause of occurrence of the cured layer having a relatively large shrinkage stress, i.e., the cured portion, is used only for the 1 st temporarily obtained 1 st cured portion 24a₁Is performed. However, the light beam having a relatively large energy density, which is a cause of occurrence of the cured portion having a relatively large shrinkage stress, is not used for formation of the cured portion obtained at the 2 nd and later. Thus, having a phaseSince the number of solidified layers, i.e., solidified portions, which are subjected to a large shrinkage stress can be relatively reduced, the occurrence of warpage in the three-dimensional shaped object finally obtained due to the above can be appropriately suppressed.

(2 nd irradiation mode)

The 2 nd irradiation mode is to irradiate the 1 st curing part 24a₁After formation, 1 shot region 50B is formed at least along the 1 st cured portion 24a₁Axially through the 1 st cured part 24a₁The form of the both main edge portions X, Y implements a form of irradiation with a light beam (see fig. 7).

As described above, the main technical idea of the present invention is to follow the 1 st cured part 24a₁To at least the 1 st cured part 24a₁The two main edge portions X, Y of the light beam. In the above-described 1 st irradiation pattern, two irradiation regions 50A are used₁、50A₂The technical idea is realized. However, the present invention is not limited to the 1 st irradiation mode for realizing the technical idea. For example, the technical idea of the present invention may be realized by using only 1 irradiation region 50B. Specifically, 1 irradiation region 50B may be provided at least along the 1 st cured part 24a₁Axially through the 1 st cured part 24a₁The two main edge portions X, Y carry out the irradiation of the light beam.

According to this embodiment, 1 irradiation region 50B is formed as the 1 st cured portion 24a to be temporarily formed in a plan view₁Passes through the 1 st cured part 24a so as to cover the entire area₁. Accordingly, the 1 st cured part 24a is appropriately included in the irradiation region 50B of the light beam L in a plan view₁And two main edge portions X, Y. Therefore, the irradiation heat of the light beam L is appropriately supplied to the entire region including the both main edge portions X, Y in the temporary solidified state, whereby the entire region including the both main edge portions X, Y can be changed from the solidified state to the molten state. Therefore, since the two main edge portions X, Y included in the entire region are also melted, the two main edge portions X, Y can be located at the 1 st solidified part 24a in cross section₁The non-irradiated portion of the light beam on the outer side (see fig. 2) flows in a manner of being wetted and diffused in the direction in which the light beam is supplied. Therefore, the flow operation irradiates light to both main edge portions X, YThe 1 st cured part 24a before the beam L₁In contrast, the height of the 1 st cured portion obtained by irradiating both main edge portions X, Y with the light beam L and then curing the light beam L can be further reduced. In the present embodiment, as described above, the 1 st cured portion 24a, which is temporarily formed in a plan view in the 1 st irradiation region 50B₁Passes through the 1 st cured part 24a so as to cover the entire area₁. Therefore, the two irradiation regions 50B are caused to pass through at least the 1 st cured part 24a₁The conditions for passing through the alignment of the irradiation region can be simplified as compared with the case of both main edge portions. That is, in this embodiment, the through-positioning of the irradiation region is easier than in the 1 st irradiation embodiment. In this regard, the present aspect is technically advantageous.

In this embodiment, the 1 st cured portion 24a is more preferably formed₁The two main edge portions X, Y of the light beam₁Is located at the 1 st cured part 24a₁Beam diameter D of the beam used in formation₂Large (see fig. 7). The "beam diameter (D) of a light beam" described in the present specification₁/D₂) ", means that the energy intensity value in the beam spot is 1/e as compared with the peak energy intensity value in the case where the energy distribution of the light beam is Gaussian distribution²(13.5%) or more (see fig. 7).

This embodiment is characterized in that 1 irradiation region 50B is formed as the 1 st cured portion 24a temporarily in a plan view as described above₁Passes through the 1 st cured part 24a so as to cover the entire area₁. However, in the 1 st cured part 24a₁When the width of (3) is substantially the same as the width of 1 irradiation region 50B, the 1 st cured part 24a may be formed in some cases₁The two main edge portions X, Y are not properly contained in the irradiation region 50B of the light beam L in plan view. Therefore, in view of this situation, the 1 st cured part 24a is more preferable₁The two main edge portions X, Y of the light beam₁Is located at the 1 st cured part 24a₁Beam diameter D of the beam used in formation₂Is large. This enables the 1 st cured part 24a to be formed₁The two main edge portions X, Y are more appropriately (reliably) contained in the irradiation region of the light beam LWithin domain 50B.

In one aspect, 1 shot region 50B is formed₁It is preferable to use a light beam having a higher energy density on both sides of the scanning center line l than on the scanning center line l (see fig. 8). In addition, the "scanning center line of the light beam" described in the present specification means a line obtained by dividing the irradiation region of the light beam moving along the scanning path of the light beam by 2.

As described above, the main technical idea of the present invention is to cure the part 24a in the 1 st cured part₁After formation, at least the 1 st cured part 24a₁The two main edge portions X, Y of the light beam. According to this technical idea, the temporarily formed 1 st cured portion 24a can be reduced₁Of (c) is measured. That is, the first cured portion 24a is formed temporarily₁The two main edge portions X, Y where the illumination beam is the key point. Thus, the first cured portion 24a is treated in plan view₁The irradiation of the beam of the intermediate portion Z does not particularly contribute to the technical effect of the present invention. Therefore, it is desirable to more appropriately set the first cured portion 24a to the 1 st cured portion 24a₁Of the two main edge portions X, Y. From this viewpoint, in one aspect, 1 irradiation region 50B is formed₁It is preferable to use a light beam having a greater energy density on both sides of the scanning center line l than on the scanning center line l. This makes it possible to suppress the 1 st cured part 24a which does not contribute much (is small) to the technical effect of the present invention₁Is irradiated with a high energy density beam. This enables formation of the first cured portion 24a₁The irradiation efficiency of the light beams of 1 irradiation region of the two main edge portions X, Y is improved. Specifically, the light beam used in the present embodiment is such that the energy of the light beam is hardly supplied to the 1 st curing part 24a₁The configuration of the middle portion Z of (a). Therefore, when a light beam having a predetermined energy density as a whole is used, the 1 st cured portion 24a can be focused and effectively treated₁The two main edge portions X, Y supply the energy of the beam. That is, in this embodiment, the portion (the 1 st cured portion 24 a) where the irradiation of the light beam is particularly necessary is large₁X, Y) to supply energy to the beam, thereby reducing the need for irradiation of the beamThe less large (smaller) part supplies the energy of the beam. Therefore, the 1 st curing part 24a during irradiation can be made to be more suitable than the case where the energy of the light beam is supplied to a portion where the irradiation necessity of the light beam is not so large (small)₁The thermal history (temperature change) of (2) becomes small.

In one aspect, it is preferable that 1 irradiation region 50B is provided₂Alternately passing through the 1 st curing part 24a₁The one of the two main edge portions (X) and the other of the two main edge portions (Y) of (a) (see fig. 9) is irradiated with a light beam.

As described above, when the light beam forming 1 irradiation region is used, there is a 1 st cured portion 24a to be formed once in a plan view₁Passes through the 1 st cured part 24a so as to cover the entire area₁The form of (1). In this embodiment, the first cured portion 24a is treated in plan view₁The irradiation with the light beam at the intermediate portion of (2) does not contribute much (to a small extent) to the technical effect of the present invention. Therefore, it is desirable to more appropriately set the first cured portion 24a to the 1 st cured portion 24a₁Of the two main edge portions X, Y. Therefore, in one aspect, it is preferable that 1 irradiation region 50B is provided₂Alternately passing through the 1 st curing part 24a₁The one of the two main edge portions (X) and the other of the two main edge portions (Y) of (a) are irradiated with a light beam. Thus, even when this mode is used, it is possible to use 1 irradiation region 50B instead of two irradiation regions₂Passing through the first cured part 24a in a zigzag pattern₁The two main edge portions X, Y suitably energize the beam. In this embodiment, 1 irradiation region 50B is used₂When the light beam passes through the substrate in a zigzag manner, the energy of the light beam is focused on a portion where the irradiation of the light beam is particularly necessary (the 1 st cured part 24 a)₁Two main edge portions X, Y). On the other hand, 1 irradiation region 50B is added₂Passing through the part in a zigzag pattern, the energy of the light beam is not easily irradiated to a small part (the 1 st cured part 24 a) where the irradiation necessity of the light beam is not so large₁Middle portion Z) of the feed. Therefore, the portion (the 1 st cured part 24 a) where the irradiation necessity to the light beam is not so large (small) can be reduced₁Of (2) a middle partZ) the case of irradiating a light beam of high energy density.

In one aspect, it is preferable that the position of the irradiation region of the light beam used in the formation of the 1 st cured part is shifted for each cured layer. Thereby, it is possible to appropriately avoid the arrangement of the light beams having a relatively large energy density in a line along the z-axis direction. Therefore, it is possible to avoid concentration of the shrinkage stress of the 1 st cured part, which is a cause of the warpage of the shaped object, in a line along the z-axis direction. Therefore, the strength of the shaped object to be finally obtained can be improved as a whole.

In the 1 st irradiation mode and the 2 nd irradiation mode, the light beam may be irradiated to at least both main edge portions of the 1 st curing part, following the formation of the 1 st curing part. In addition, the phrase "irradiating light beams to at least both main edge portions of the 1 st cured part subsequent to the formation of the 1 st cured part" as used herein means that the light beams are irradiated to at least both main edge portions of the 1 st cured part immediately after the formation of the 1 st cured part. As described above, as the timing of irradiating the other main edge portion of at least the 1 st curing part with the light beam, irradiation of the light beam along each scanning path (after … forming the 4 th curing part, the 5 th curing part, the 6 th curing part, etc.) and irradiation of the other main edge portion of the 1 st curing part may be included so that the scanning paths of the light beam are arranged in parallel in one direction. In view of reducing the height of the 1 st cured portion formed once at an early timing (early timing), the light beam may be irradiated not only to one main edge portion of the 1 st cured portion but also to the other main edge portion immediately after the 1 st cured portion is formed once. Thereby, the height of the 1 st solidified portion formed once has been reduced at an earlier timing (earlier timing), so that it is possible to appropriately cope with even a case where the timing of laying down the next powder layer is earlier than usual.