KR102373953B1 - Three-dimensional printer with fixed table and up-down movable table and method for three-dimensional printing using the printer - Google Patents

Abstract

The present invention is to provide a three-dimensional printer and a printing method using the same to quickly perform printing while reducing consumption of a powder material when manufacturing a column-shaped structure. According to an embodiment of the present invention, provided is a three-dimensional printer of a powder lamination and fusion (PBF) type, comprising: an elevating table that defines at least a portion of the lower surface of a bed area of the printer and is movable in a vertical direction; a laser printing device for forming a structure by irradiating a powder material stacked on the elevating table with a laser; and a column-shaped fixed table disposed in the central portion of the bed area.

Description

{Three-dimensional printer with fixed table and up-down movable table and method for three-dimensional printing using the printer}

The present invention relates to a three-dimensional printing method, and more particularly, a three-dimensional printer capable of reducing the amount of powder material used and rapid printing by laminating a powder material only in a partial area of a printer bed and manufacturing a three-dimensional structure, and a 3D printer using the same It relates to a dimensional printing method.

The three-dimensional (3D) printing technology is easy to produce complex three-dimensional shapes and is suitable for a small quantity production environment of various kinds, so the demand in various industrial fields is increasing. As a 3D printing method using metal powder, there is a PBF (Powder Bed Fusion) method.

The PBF method is a method of manufacturing a structure by laminating metal powder layer by layer on a flat floor and then sintering it with a laser. Do.

1 schematically shows some components of a conventional 3D printer of a general PBF method. Conventional 3D printer includes a laser output device 10, a laser irradiation device 15, and the like, including a laser irradiation unit and a material supply unit 3, a material recovery unit 5, a table 1, an actuator 2, and a bed B ), and a body portion composed of a scraper 6 and the like.

A scraper 7 reciprocates across the bed B from one side of the bed B to the opposite side, and laminates the powder material PW to a thickness of approximately 30 to 50 micrometers, and applies a laser to the layered powder material. It is formed by sintering the structure by irradiation. After that, the bottom surface of the bed (B) is lowered at a predetermined interval, the scraper (6) stacks the powder material again on it, and irradiates a laser to the stacked powder to form a structure. form a dimensional structure.

2 schematically shows a view from above of the tubular structure 7 of the bed B. When manufacturing the tubular structure 7 with an empty interior as described above, the above-described PBF printing operation is quite It's an inefficient way. For example, when forming the cylindrical structure 7 with a diameter and height of several tens of centimeters, the bed B must be fully filled with powder material. In addition to costing tens of thousands of won to hundreds of millions of won, there is a problem in that productivity is greatly reduced because it takes several days to several weeks to work.

Patent Document 1: Korean Patent Registration No. 10-1855184 (Notice on May 11, 2018) Patent Document 2: Korean Patent Publication No. 2016-0141144 (published on December 08, 2016)

The present invention has been devised to solve the above problems, and an object of the present invention is to provide a three-dimensional printer capable of reducing the consumption of powder material when manufacturing a cylindrical structure and quickly performing a printing operation, and a printing method using the same.

According to an embodiment of the present invention, there is provided a three-dimensional printer of the powder lamination and fusion (PBF) method, comprising: an elevating table that defines at least a portion of a lower surface of a bed area of the printer and is movable in the vertical direction; a laser output device for forming a structure by irradiating a laser to the powder material stacked on the lifting table; and a column-shaped fixed table disposed in the center of the bed area, wherein the lifting table has a through hole through which the fixed table can pass, and the fixed table is installed through the through hole, but before the printing operation There is provided a three-dimensional printer, characterized in that the upper surfaces of the lifting table and the fixed table are positioned at the same height, the fixed table height is fixed during a printing operation, and the lifting table is lowered by a predetermined interval.

According to an embodiment of the present invention, there is provided a printing method using the above-described three-dimensional printer, comprising: a lamination step of laminating a powder material on a partial area of an upper part of the lifting table using a scraper that applies the powder material to the upper part of the lifting table; a sintering step of sintering the two-dimensional structure and the first barrier layer by irradiating a laser to the stacked powder material based on the two-dimensional shape information of the structure to be manufactured; and repeating the lamination step and the sintering step a plurality of times to form a three-dimensional structure and a first barrier layer, wherein the first barrier layer divides the partial area of the upper part of the elevating table and the remaining area except this. It provides a three-dimensional printing method, characterized in that formed.

According to an embodiment of the present invention, it is not necessary to laminate the powder material on the entire bed during the production of the cylindrical three-dimensional structure, so that the powder material is not wasted unnecessarily. can have an effect.

1 is a diagram illustrating a conventional exemplary three-dimensional printer;
2 is a view for explaining the problems of the conventional 3D printer;
3 and 4 are views for explaining a 3D printer according to an embodiment of the present invention;
5 to 7 are views for explaining a method of manufacturing a three-dimensional structure according to an embodiment;
8 to 10 are views for explaining a table configuration of a 3D printer according to an alternative embodiment;
11 and 12 are views for explaining a method of forming a three-dimensional structure using a barrier layer according to an embodiment;
13 and 14 are views for explaining a method of forming a three-dimensional structure using a barrier layer according to an alternative embodiment;
15 is a view for explaining a method of forming a three-dimensional structure using a barrier layer according to another alternative embodiment;
16 is a view for explaining a method of forming a three-dimensional structure using an inclined barrier layer according to another alternative embodiment.

The above objects, other objects, features and advantages of the present invention will be easily understood through the following preferred embodiments in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosed subject matter may be thorough and complete, and that the spirit of the present invention may be sufficiently conveyed to those skilled in the art.

In this specification, the singular also includes the plural unless specifically stated otherwise in the phrase. As used in the specification, elements mentioned in the expressions 'comprising', 'consisting of' or 'consisting of' do not exclude the presence or addition of one or more other elements.

Hereinafter, the present invention will be described in detail with reference to the drawings. In describing the specific embodiments below, various specific contents have been prepared to more specifically explain and help the understanding of the invention. However, readers with enough knowledge in this field to understand the present invention It can be recognized that it can be used without specific content. In some cases, it should be mentioned in advance that parts which are commonly known in describing the invention and which are not largely related to the invention are not described in order to avoid confusion in describing the present invention.

In the following examples, it is assumed that the three-dimensional printer of the present invention is a powder bed fusion (PBF) printer. The PBF type printer is a printer that irradiates a powder-type material with a high-energy beam (eg, laser or electron beam) and sinters the powder to produce an article. ), SLM (Selective Laser Melting), or EBM (Electron Beam Melting) method. Therefore, the present invention is not limited to the PBF printer, but can be applied to any 3D printer in which an article is manufactured by sintering a powder material.

3 and 4 schematically show a side cross-section of a 3D printer according to an embodiment of the present invention, and FIG. 4 schematically shows a bed area of the printer of FIG.

Referring to the drawings, it includes a three-dimensional laser irradiator and a printer body 100 according to an embodiment. The laser irradiation unit is a device for outputting a laser (L) for sintering the powder material 60 , and may include a laser output device 10 , an optical element 11 such as a mirror, and a laser irradiation device 15 . . The laser output device 10 may include a laser generator for generating a laser, or alternatively, a device for transmitting the laser generated by the laser generator (not shown) to the laser irradiation device 15 side.

As a laser for sintering powder materials, for example, an Nd:YAG laser having an energy of 30W to 1000W, preferably 500W, may be used, but the present invention is not limited thereto, and various wavelengths and output energy of various wavelengths and output energy according to specific embodiments may be used. A laser may be used.

The laser L output from the laser output device 10 is transmitted to the laser irradiation device 15 by one or more optical elements such as the optical element 11 or optical fiber. The laser irradiation device 15 irradiates a laser (L) on the powder material stacked on the bed to sinter the powder material to fabricate (print) the three-dimensional structure. In one embodiment, the laser irradiation device 15 may be implemented as a galvano scanner, and may irradiate the laser to any point within the printing area by adjusting the direction of the laser.

Although not shown in the drawing, in one embodiment, a transport mechanism for transporting the laser irradiation device 15 along a plane parallel to the bed (that is, the X-Y plane) may be further included. Additionally, the transport mechanism may transport the laser irradiation device 15 in the vertical direction (ie, the Z-axis direction).

In one embodiment of the present invention, the printer body 100 includes a material supply unit 41 , a material recovery unit 43 , a bed B, a lifting table 20 , a fixed table 50 , and a scraper 70 . can be provided.

The material supply unit 41 stores the powder material PW and discharges it upward by a predetermined amount. For example, as shown in the drawing, the elevating unit 42 is installed at the lower portion of the material supply unit 41 so that the powder material PW in the material supply unit 41 can be discharged by a predetermined amount while ascending by a predetermined height. In the present invention, the powder material (PW) may be a powder of any material that can be sintered by a laser. For example, in one embodiment, the powder material may be a metal powder or a plastic resin material powder. Alternatively, one or more material supply units 41 may be provided to use one or more types of powder materials.

The bed B is formed in the body portion 100 to receive the powder material PW. In one embodiment, the inner region of the bed B is defined by the lower elevation table 20 and the sidewalls of the four sides of the body portion 100 surrounding it.

The lifting table 20 defines at least a part of the lower surface of the bed (B) area of the printer and is configured to be movable in the vertical direction. In the illustrated embodiment, the lifting table 20 is detachably fastened to the at least two first actuators 30 to be able to ascend and descend in the vertical direction. The lifting table 20 may be coupled to the actuator 30 by being detachably fastened to the fastening part 31 of the upper part of the two first actuators 30 , for example.

The fixed table 50 is a column-shaped member and may be disposed at an approximately central portion of the bed (B) area. At this time, the lifting table 20 has a through hole 21 through which the fixed table 50 can pass, and the fixed table 50 is installed through the through hole 21 . For example, as shown in FIG. 4 , when viewed from above, the fixed table 50 is positioned at a substantially central portion of the bed B and the lifting table 20 surrounds the fixed table 50 .

Before starting the printing operation, the upper surfaces of the lifting table 20 and the fixed table 50 are positioned at the same height as shown in FIG. 3 . When the printing operation is started, the fixed table 50 is fixed without moving, so that the height does not change and the lifting table 20 is lowered by the actuator 30 at a predetermined interval. In one embodiment, the lifting table 20 may be lowered by, for example, a height of approximately 30 μm to 50 μm at a time by the actuator 30 . When the powder material (PW) is discharged to the upper part of the body part 100 from the material supply unit 41 every time it descends once, the scraper 70 pushes the discharged powder toward the bed (B) to the upper surface of the lifting table 20 Apply evenly to That is, as shown in FIG. 4 , the scraper 70 disposed at a preset position on the left (in the drawing) of the main body 100 is a distance d1 from a preset position on the right (eg, the position of the scraper 70'). ) to uniformly apply the powder material PW to the upper surface of the lifting table 20 , and recover the remaining powder material after application to the material recovery unit 43 . In this way, whenever the powder material is stacked on the bed (B) layer by layer, the laser irradiation device 15 repeats the operation of irradiating the laser (L) to the powder material based on the shape information of the two-dimensional structure and sintering the three-dimensional structures can be crafted.

Meanwhile, in an alternative embodiment of the present invention, the structure or arrangement of the material supply unit 41 , the material recovery unit 43 , and the bed B of the main body 100 of the printer may vary according to specific embodiments. For example, in the embodiment shown in the drawings, the material supply 41 is arranged on the left side of the bed B and the material recovery unit 43 is arranged on the right side, but in an alternative embodiment the material supply 41 and the recovery unit (43) may be all located on one side of the bed (B). In addition, the material supply part 41 is not embedded in the body part 100, but may be disposed on the upper part of the body part 100 or located inside the scraper 70. In this case, the powder material (PW) of the body part 100 It can be supplied by falling from the upper part to the bed (B) area.

5 to 7 show a method of manufacturing a three-dimensional structure according to an embodiment, in particular, a step of forming a structure having a cylindrical shape. For convenience of explanation, the drawing schematically shows only the elevation table 20 and the fixed table 50, the sidewalls of the main body 100 surrounding it, and the scraper 70 when viewed from the side.

Referring to Fig. 5 (a), the scraper 70 reciprocates a distance d1 to laminate the powder material PW on the bed B. That is, in the illustrated embodiment, the scraper 70 is a return point (eg, indicated by a dotted line in the drawing) that is a predetermined distance d1 away from the initial waiting point (eg, the position of the scraper 70 shown by a solid line in the drawing). After moving to the position of the scraper 70'), it returns to the standby point again. At this time, since the fixed table 50 is not lowered and the upper surface of the fixed table 50 and the lower end of the scraper 70 are at the same height, the powder material PW is not applied to the upper surface of the fixed table 50. does not

Thereafter, as shown in FIG. 5( b ), the two-dimensional structure 200 is sintered and formed by irradiating a laser to the powder material PW from the laser irradiation device 15 . The two-dimensional structure 200 generated at this time is formed in a ring (annular) shape along the circumference of the fixed table 50 having a cylindrical shape. Here, the two-dimensional structure is a shape obtained by slicing a three-dimensional structure to be produced by a printer in the horizontal direction at regular intervals. It will be understood by those skilled in the art that, for the sake of distinction, reference is made to a two-dimensional structure herein.

After that, as indicated by the arrow, the lifting table 20 is lowered at a predetermined interval by driving the actuator 30, and the scraper 70 reciprocates the distance d1 as shown in FIG. ) is again laminated with the powder material (PW). Since the fixed table 50 does not move, the powder material is not stacked on the fixed table 50 and the powder material PW is stacked on the lifting table 20 . Thereafter, as shown in FIG. 6(b), the ring-shaped two-dimensional structure 200 is sintered and formed by irradiating a laser, and the lifting table 20 is lowered again by a predetermined interval. By repeating this operation, it is possible to form the cylindrical structure 200 having a predetermined height.

On the other hand, in an alternative embodiment, the fixed table 50 can be configured to move down to a predetermined height within a limited range, and in this case, a cup-shaped structure with one end closed can be made. For example, when both the lifting table 20 and the fixed table 50 are lowered below a predetermined interval and layered thereon with powder material (PW), the lifting table 20 and the fixed table 50 as shown in FIG. ) are coated with a powder material (PW) of a predetermined height, and sintered with a laser to form a cup-shaped structure 200 composed of a cylindrical side part 200a and a bottom surface 200b as shown in FIG. 7(b). can make

8 to 10 show a table configuration of a three-dimensional printer according to an alternative embodiment.

8 shows a case in which the elevating table 20 and the fixed table 50 of FIG. 3 are replaced with a single integrated table 22. As shown in FIG. That is, the fixed table 20 and the lifting table 50 are removed from the printer, and the integral lifting table 22 defining the entire lower surface of the bed (B) area is attached to the fastening part 31 of the two first actuators 30. can be concluded on The integrated lifting table 22 can be moved up and down by the operation of the first actuator 30. Therefore, when it is necessary to manufacture a structure of a general shape rather than a cylindrical structure, as shown in FIG. 8, the integrated lifting table 22 is used. It can be replaced to create a 3D structure.

9 shows a case in which the fixed table 50 is replaced with a structure capable of lifting and lowering within a predetermined range. That is, as shown in FIG. 9 , an additional second actuator 60 may be installed in the printer, and the lifting table 51 may be fastened to the fastening portion of the second actuator 60 to be installed. The elevating table 51 has a column shape similar to that of the fixed table 50 of FIGS. 3 and 4 , but a lowering motion is possible in a predetermined range by the second actuator 60 . In this embodiment, since the elevating table 51 can be descended, for example, as shown in FIG. There is an advantage.

In addition, in the embodiment of Fig. 9, for example, if the integrated lifting table 22 of Fig. 8 is to be installed, both the lifting tables 20 and 51 are removed in Fig. 9 and the integrated lifting table 22 is attached to the second actuator 60. Alternatively, the integrated lifting table 22 may be fastened to the two first actuators 30 .

The embodiment of FIG. 10 shows the elevation table 20 and the fixed table 50 as viewed from above. In one embodiment, the stationary table 50 has a rectangular column shape and a rectangular through hole 21 of the elevation table 20 is provided. ) through the fixed table 50 is installed. That is, the fixed table 50 does not need to have a circular column shape, and according to the shape of the structure to be manufactured, a column-shaped fixed table 50 having a cross section of an arbitrary polygonal shape such as a rectangle or a pentagon is used and elevates accordingly The through hole 21 of the table 20 may also use a lifting table having a through hole of the same shape.

11 and 12 show a method of forming a three-dimensional structure according to another exemplary embodiment, FIG. 11 is a side view of the bed B of the printer apparatus, and FIG. 12 is a view from above.

First, the lifting table 20 is lowered at a predetermined interval, and as shown in Figs. 11 (a) and 12 (a), the powder material PW is applied to the upper surface of the lifting table 20 using a scraper 70. . At this time, the scraper 70 is a return point (for example, a scraper indicated by a dotted line in the drawing) that is a predetermined distance d2 away from a predetermined waiting point (eg, the position of the scraper 70 illustrated by a solid line in FIG. 11A ). After moving only to the position of 70'), it returns to the standby point again, and therefore, the powder material is not laminated on the entire upper surface of the lifting table 20, but only in a partial area.

Then, as shown in FIG. 12(b), a ring-shaped structure 200 is formed around the fixed table 50 by irradiating a laser, and at this time, a barrier layer 80 is also formed around the structure 200 at the same time. . The barrier layer 80 serves to partition an area in which the powder material PW is stacked and an area in which the powder material PW is not stacked on the elevating table 20 . For example, when the standby point of the scraper 70 is located on the first side of the bed (B) area, the barrier layer 80 is fixed to the second side of the bed (B) area facing the first side. It may be formed at a predetermined position between the tables 50 . The barrier layer 80 may be formed in a straight shape having a certain length in the width direction of the bed B when viewed from above, for example, as shown in FIG. 12(b), and in an alternative embodiment, an annular structure ( 200) may be formed in an arc shape to partially surround the periphery.

The scraper 70 reciprocates from the stand-by point (eg, the point of the scraper 70) to the return point (eg, the point of the scraper 70') to deposit the powder material and laser to the structure 200 and the barrier layer 80. If the forming operation is repeated a plurality of times, the barrier layer 80 having a wall shape in a straight line with the cylindrical structure 200 is formed as shown in FIG. 11(c). At this time, the barrier layer 80 is spaced apart from the three-dimensional structure 200 by a certain distance (eg, several millimeters to several centimeters) to prevent the stacking of the powder material PW from collapsing. It is formed to protect one side.

By forming the barrier layer 80 around the structure 200 in this way, the barrier layer 80 serves to partition an area where the powder material is stacked and an area where the powder material is not stacked in the bed B, and the powder material PW is To be able to be stacked uniformly and flatly around the structure 200 .

In one embodiment, the barrier layer 80 is preferably formed to surround the structure 200 as close as possible, and the thickness, shape, and formation position of the barrier layer 80 may vary depending on specific embodiments. When the three-dimensional structure 200 is completed, the barrier layer 80 is separated from the lifting table 20 and discarded. Therefore, it is preferable that the width of the barrier layer 80 be as narrow as possible in order to reduce the amount of laser irradiation when forming the barrier layer 80 and also reduce the amount of wasted powder material. In one embodiment, the width of the barrier layer 80 may be 1 millimeter, and according to a specific embodiment, the width of the barrier layer 80 may be smaller or larger than this.

In addition, in this embodiment, the scraper 70 is sufficient to uniformly and evenly laminate the powder material PW from one side of the bed B to the barrier layer 80, immediately after passing through the barrier layer 80 or the barrier layer After passing (80), it can move to any return point and then return, and the return point may vary according to a specific embodiment of the invention. In general, the powder that has been used once can be reused, but it is desirable to reduce the amount of powder reused if possible, since frequent use of the powder will oxidize or damage the powder. Thus, in order to reduce the amount of powder material wasted in the area outside the barrier layer 80 , in one embodiment, the return point of the scraper 70 is passed through the top of the barrier layer 80 or the top of the barrier layer 80 . It can be set to the point immediately after.

According to the above-described embodiment, when the cylindrical structure 200 is manufactured, the cylindrical fixed table 50 is arranged in the center of the bed B and the cylindrical structure 200 is formed together with the barrier layer 80, so the fixed table ( 50) as much as the volume of powder material and as much as the volume of the area outside the barrier layer 80, it is not necessary to use the powder material as much as the volume of the area outside the barrier layer 80, so the amount of powder material used can be greatly reduced and the movement distance of the scraper 70 can be reduced, so that the structure can be shortened in a short time. There is an advantage that can be produced in

13 and 14 show a method of forming a three-dimensional structure using a barrier layer according to an alternative embodiment, wherein FIG. 13 is a side view of a bed B of the printer apparatus, and FIG. 14 is a view from above.

The lifting table 20 is lowered at a predetermined interval, and powder material PW is applied to a part of the upper surface of the lifting table 20 using a scraper 70 as shown in FIGS. 13(a) and 14(a). do. At this time, the scraper 70 is provided with a powder material supply pipe 75 therein, and thus the powder material (PW) is supplied to the upper part of the lifting table 20 through the supply pipe 75 and at the same time pressurized to the lower end of the scraper 70, It is assumed that the powder material (PW) can be stacked at a constant height.

When using such a scraper 70, the scraper 70 is a return point (eg, a predetermined distance d3) away from a predetermined standby point (eg, the position of the scraper 70 shown by a solid line in FIG. 13(a)). It moves only to the position of the scraper 70 ′ indicated by the dotted line in the drawing) and then returns to the standby point again, so that the powder material is laminated on a smaller area of the lifting table 20 compared to the embodiment of FIGS. 11 and 12 . can do.

Then, as shown in FIG. 14(b), a ring-shaped structure 200 is formed around the fixed table 50 by irradiating a laser, and at the same time, one barrier layer 80 is formed on each side of the structure 200. do. The barrier layer 80 serves to partition an area in which the powder material PW is stacked and an area in which the powder material PW is not stacked on the elevating table 20 . For example, when the waiting point of the scraper 70 is located on the first side of the bed (B) area, the barrier layer 80 is located at a predetermined first position between the first side and the fixed table 50 and the The second side of the bed (B) region facing the first side and may be respectively formed at a second predetermined position between the fixed table (50). As shown in Fig. 14 (b), the barrier layer 80 may be formed in a straight shape having a certain length in the width direction of the bed B when viewed from above, but in an alternative embodiment, the barrier layer 80 is formed around the annular structure 200 in an alternative embodiment. Each may be formed in an arc shape so as to partially surround it.

If the scraper 70 reciprocates the distance d3, laminates the powder material, and forms the structure 200 and the barrier layers 80 on both sides with a laser, repeating a plurality of times, as shown in Fig. 13(c), a cylinder The structure 200 and the two barrier layers 80 in the shape of a straight wall are formed. At this time, each barrier layer 80 is spaced apart from the three-dimensional structure 200 by a certain distance (eg, several millimeters to several centimeters) to prevent the stacking of the powder material PW from collapsing. It is formed to protect one side of each.

Fig. 15 shows a three-dimensional structure and a barrier layer according to another alternative embodiment, in which Fig. 15 (a) is a top view of the bed (B) region, and Fig. 15 (b) is a schematic cross-section viewed from the side. indicates.

In this embodiment, in order to prevent the stacking of the powder material PW from collapsing in the area outside the barrier layer 80 , the barrier layer 80 is formed at a position adjacent to the three-dimensional structure 200 at a certain distance and at the same time An additional barrier layer 90 is formed in an area outside the barrier layer 80 .

The location of the formation of the additional barrier layer 90 is the area outside the barrier layer 80 , that is, the area opposite the structure 200 with the barrier layer 80 as the center or the sidewall of the bed B in the barrier layer 80 . is the area to In one embodiment, the additional barrier layer 90 may be spaced from the barrier layer 80 by approximately 5 millimeters to 10 millimeters and a width of, for example, 1 millimeter. However, the shape, length, width, etc. of the additional barrier layer 90 may vary according to specific embodiments.

The additional barrier layer 90 may be formed at the same height as the barrier layer 80, and may be formed at a height lower than the barrier layer 80 if there is no problem in the flat lamination of the powder material inside the barrier layer 80 as shown. may be

Also, in an alternative embodiment, two or more additional barrier layers 90 may be formed when a tall structure 200 is to be formed. In this case, if there are two or more additional barrier layers 90, even if the extra powder material is stacked on a very steep slope in the area outside of the very high structure 200 and the barrier layer 80, these additional barrier layers 90 are Since it acts as a buffer for supporting the powder material on the steep slope, the powder material inside the barrier layer 80 can be uniformly and flatly laminated, and the shape of the additional barrier layer 90 according to the stacking height of the structure 200 , the number, etc. can be appropriately set.

16 shows a three-dimensional structure and a barrier layer according to another alternative embodiment.

In FIG. 16 , the three-dimensional structure 200 and the barrier layer 80 and the additional barrier layer 90 at adjacent distances are formed, for example, the same as in the embodiment of FIG. 15 . However, according to the alternative embodiment of FIG. 16 , when the additional barrier layer 90 is formed, as the height of the additional barrier layer 90 increases, it is inclined inwardly (ie, inclined toward the barrier layer 80 ). . That is, the barrier layer 80 is formed by stacking vertically, but the additional barrier layer 90 is tilted toward the structure 200 by stacking it in a direction toward the structure 200 (or barrier layer 80) during each stack formation. to form a slope. According to this embodiment, it is possible to reduce the amount of the powder material PW' accumulated in the area outside the additional barrier layer 90 .

That is, when the additional barrier layer 90 is formed vertically as shown in FIG. 15 , as the stacking height of the powder material increases, a large amount of powder material is injected even in the area outside the additional barrier layer 90 to prevent the powder material stack from collapsing. However, when the additional barrier layer 90 is inclined inward as shown in FIG. 16 , the powder material PW′ in the outer region of the additional barrier layer 90 is relatively less as the additional barrier layer 90 is inclined. Since they are stacked steeply, the amount of the powder material PW' in the area outside the additional barrier layer 90 can be further reduced.

Meanwhile, FIG. 16 illustrates the formation of the additional barrier layer 90 inclined as an example. For example, in an embodiment in which only the barrier layer 80 is formed without the additional barrier layer 90 , the barrier layer 80 is formed by forming the structure 200 . It will be understood that the outermost additional barrier layer may also be formed inclined toward the uppermost side in an embodiment in which two or more additional barrier layers 90 are formed.

As described above, those of ordinary skill in the art to which the present invention pertains can understand that various modifications and variations are possible from the description of this specification. Therefore, the scope of the present invention should not be limited to the described embodiments and should be defined by the claims described below as well as the claims and equivalents.

10: laser output device 11: optical element
15: laser irradiation device 20: elevating table
30, 60: actuator 50: fixed table
70: scraper 80: barrier layer
90: additional barrier layer 100: printer body part
200: structure

Claims (13)

As a 3D printer of powder lamination and melting (PBF) method,
an elevating table defining at least a part of a lower surface of the bed area of the printer, connected to the first actuator, movable in the vertical direction, and having a through hole in the center;
a laser output device for forming a structure by irradiating a laser on the powder material stacked on the lifting table; and
and a column-shaped fixed table disposed in the through hole and disposed in the center of the bed area. The method of claim 1,
The elevating table is detachably fastened to at least two first actuators and is configured to move up and down in a vertical direction. 3. The method of claim 2,
The fixed table is detachably fastened to the printer,
3D printer, characterized in that the fixed table and the lifting table can be removed from the printer and the lifting table defining the entire lower surface of the bed area can be fastened to the two first actuators. 3. The method of claim 2,
The 3D printer, characterized in that the fixed table is detachably fastened to the second actuator and configured to move up and down within a predetermined range. 5. The method of claim 4,
3D printer, characterized in that the fixed table and the lifting table can be removed from the printer and the lifting table defining the entire lower surface of the bed area can be fastened to the second actuator. As a printing method using the three-dimensional printer of any one of claims 1, 2, 4 or 5,
laminating step of laminating the powder material on a partial area of the upper part of the lifting table using a scraper that applies the powder material to the upper part of the lifting table;
a sintering step of sintering the two-dimensional structure and the first barrier layer by irradiating a laser to the stacked powder material based on the two-dimensional shape information of the structure to be manufactured; and
Including; repeating the lamination step and the sintering step a plurality of times to form a three-dimensional structure and a first barrier layer;
The first barrier layer is a three-dimensional printing method, characterized in that formed to partition the partial area on the upper part of the lifting table and the remaining area except the area. 7. The method of claim 6,
When the waiting point of the scraper is located on the first side of the bed area, the first barrier layer is formed at a predetermined position between the fixing table and the second side of the bed area facing the first side. A three-dimensional printing method characterized in that. 8. The method of claim 7,
In the laminating step, the scraper reciprocates a distance (d2) from the preset standby point to a preset return point on the first barrier layer three-dimensionally, characterized in that the powder material is applied to the partial area printing method. 7. The method of claim 6,
When the waiting point of the scraper is located on the first side surface of the bed area, the first barrier layer is formed at a predetermined first position between the first side surface and the fixed table and the bed area facing the first side. 3D printing method, characterized in that each formed at a second predetermined position between the second side and the fixed table. 10. The method of claim 9,
In the laminating step, the scraper reciprocates a distance (d3) from a predetermined standby point above the first position to a predetermined return point above the second position to apply the powder material to the partial area 3D printing method. 7. The method of claim 6,
simultaneously forming a second barrier layer together with the three-dimensional structure and the first barrier layer by the method,
wherein the second barrier layer is a barrier layer adjacent to the first barrier layer but formed at a position opposite to the structure with respect to the first barrier layer. 12. The method of claim 11,
3D printing method, characterized in that when the second barrier layer is formed, the second barrier layer is inclined toward the first barrier layer as the height of the second barrier layer increases. As a printing method using the three-dimensional printer according to claim 3,
laminating step of laminating the powder material on a partial area of the upper part of the lifting table using a scraper that applies the powder material to the upper part of the lifting table;
a sintering step of sintering the two-dimensional structure and the first barrier layer by irradiating a laser to the stacked powder material based on the two-dimensional shape information of the structure to be manufactured; and
Including; repeating the lamination step and the sintering step a plurality of times to form a three-dimensional structure and a first barrier layer;
The first barrier layer is formed to partition the partial area above the lifting table and the remaining area except for this area,
When the waiting point of the scraper is located on the first side of the bed area, the first barrier layer is formed at a predetermined position between the fixing table and the second side of the bed area facing the first side. A three-dimensional printing method characterized in that.

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