KR20190004419A - 3-dimensional printing apparatus and 3-dimensional printing method using spherical deposition model - Google Patents

Abstract

A three-dimensional (3D) printing apparatus includes: a nozzle configured to spray printing substances; a worktable to which the printing substances are injected by using the nozzles; a rotary driving unit which is configured to rotate the worktable in one or more axial directions; a parallel driving unit configured to move the nozzle in axial directions perpendicular to the surface of the worktable and one or more shafts parallel to the surface of the worktable; and a control unit which determines a 3D spherical laminate model including spherically curved layers on multiple spheres sharing the same core while corresponding to a shape to be printed and controls the rotary and parallel driving units to control the movement of the nozzle and rotation of the worktable to make the interface between the nozzle and worktable correspond to a part of the spherically curved layers on the spheres sharing the same core. The 3D printing apparatus can laminate the printing substances in the shape of the spherically curved layers through a continuous synchronized interaction between the nozzle and an operation target to print a 3D object in a precise shape including overhang and/or undercut structures without a support structure while improving efficiency and speeds compared to a conventional scheme.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-dimensional printing apparatus and a three-dimensional printing method using a spherical lamination model,

More particularly, the present invention relates to a three-dimensional printing apparatus and method using a spherical stacking model, and more particularly, to a method and apparatus for forming a three-dimensional spherically curved layer at an interface between a nozzle for injecting a printing material and a work table The present invention relates to a technique for performing three-dimensional printing while controlling the rotation of a work table and the movement of a nozzle.

The term "three-dimensional printing" refers to a technique of stacking and stacking materials one by one using three-dimensional CAD data to produce a three-dimensional object, and a three-dimensional printing apparatus is generally referred to as a three-dimensional printer . The three-dimensional printing apparatus can be classified into three types depending on the method of laminating the printing materials: a Directed Energy Deposition (DED) system, a photocurable lamination system, a laser sintered lamination system, a resin extrusion lamination system, an inkjet lamination system, And lamination method are classified by the International Standards Organization.

Among them, a three-dimensional printing apparatus using a DED system is a system in which a printing material such as a metal wire or a metal powder is supplied through a nozzle and the thermal energy of the laser is concentrated on the printing material and melted, To perform lamination. In recent years, in the 3D printing apparatus of the DED type, a technique has been developed in which a five-axis moving mechanism is provided to form an overhang and / or an undercut structure without supporting structures.

FIGS. 1A and 1B are conceptual diagrams showing an example of an existing method of stacking overprinting and / or undercut structures in a DED system using three-axis and five-axis moving mechanisms, respectively.

Conventionally, the information of the three-dimensional shape to be printed is structured with a digital model composed of a set of triangular facets, which is usually called a stereolithograph model, and a form of a file having an extension of STL (STEREO LITHOGRAPHY) Respectively. Referring to FIG. 1A, a typical example of a DED system using a three-axis moving mechanism is a plate platform 100 to which a three-dimensional workpiece is to be placed, and a plurality of parallel layers 110 And three-dimensional printing is performed in a manner of sequentially laminating. At this time, if the shape to be printed includes a structure which is not continuous with the lower end support such as an overhang or an undercut as shown in the drawing, the support structure 120 is placed on the plate platform 100 and the layers 110 are stacked thereon I had to leave.

1B, this is a typical example of a DED method using a five-axis movement mechanism, and a technique for controlling the rotation of the plate-shaped platform 100 is disclosed. In this case, without using the support structure 120 shown in FIG. 1A The overhang or undercut structure can be stacked while the plate-like platform 100 is rotated. For example, the layers 111 are stacked in the I direction without rotating the plate-type platform 100, and then the plate-shaped platform 100 is rotated by 90 degrees to stack the layers 112 in the II direction, After the plate platform 100 is rotated 90 degrees to its initial position, the layers 113 may be stacked in the III direction. At this time, although the nozzle 130 always faces the same direction, printing is performed by changing the angle between the workpiece and the nozzle 130 by controlling the direction of the workpiece in a desired direction by the rotation of the plate-shaped platform 100.

However, as described with reference to FIG. 1B, there is a problem in that the process of sequentially rotating the plate-shaped platform 100 by 90 degrees causes a delay in operation. Also, there is a problem in that the nozzle (130) 130 may cause physical interference with a workpiece printed on the plate-shaped platform 100 or the plate-shaped platform 100.

FIG. 2 is a conceptual diagram for explaining interference between a nozzle and a workpiece in a printing material stacking method using a conventional three-dimensional printing apparatus using a five-axis mechanism.

In order to stack the three-dimensional objects extending in various directions, the printing material is stacked in the vertical direction by using the nozzle 130 in the initial state as shown in FIG. 2 (a) The printing material is formed so as to form a portion extending at an angle of 90 degrees with the laminated portion in Fig. 2 (a) by rotating the plate-shaped platform 100 by -90 degrees as shown in Figs. The printing material can be stacked in the initial vertical direction by rotating the plate-shaped platform 100 by 90 degrees as shown in FIG. 2 (d).

At this time, as shown in FIGS. 2B and 2C, in the state where the plate-shaped platform 100 is rotated, the movement of the nozzle 120 in a certain region 200 There is a possibility that an overlapping area may overlap with the work on the plate platform 100 or the plate platform 100, and thus, if there is such interference, a problem that the three-dimensional object can not be printed in a desired accurate shape may occur.

Japanese Patent Application Laid-Open No. 10-2017-0015442

SUMMARY OF THE INVENTION According to an aspect of the present invention, there is provided a method of manufacturing a printing apparatus, including: forming a spherically curved layer between a nozzle for injecting a printing material and a work table; A three-dimensional printing apparatus and method for performing printing while controlling rotation and movement of a nozzle can be provided.

A three-dimensional printing apparatus according to one embodiment includes a nozzle configured to eject a printing material; A work table into which the printing material is injected by the nozzle; A rotation driving unit configured to rotate the work table in at least one axial direction; A translation drive configured to move the nozzle in at least one axis parallel to a surface of the work table and in an axial direction perpendicular to a surface of the work table; Dimensional sphere lamination (spherical area layer) model corresponding to a shape to be printed and formed of a plurality of concentric spherical spherically curved layers and controlling the rotation driving unit and the translational driving unit, And a controller configured to control rotation of the work table and movement of the nozzle such that the interface between the nozzle and the work table corresponds to a portion of the concentric spherical curved layer.

In one embodiment, each of the plurality of concentric spherical curved layers constituting the three-dimensional spherical laminate (spherical area layer) model has a shape of a part of concentric spheres having different radii, and the plurality of concentric spherical shapes The curved layer is continuously arranged in a direction in which the radius of the sphere increases around a fixed concentric point.

In one embodiment, the controller moves the nozzle by a predetermined distance in the direction of increasing the radius of the concentric sphere so that the interface between the nozzle and the work table is sequentially positioned on the plurality of concentric spherical curved layers, And controls the driving unit.

In one embodiment, the radial difference between the plurality of concentric spherical curved layers is determined by a process variable called the lamination thickness of the material and is controlled based on the amount of the printing material injected through the nozzle.

In one embodiment, the control section controls the stereolithograph model of the shape to be printed and the stacking information on the concentric spherical curved layer on each spherical surface from an intersection between the plurality of concentric spherical surfaces having different radii (Spherical area layer) model by repeating the step of creating the concentric spherical surface layer of each of the concentric spherical curved surfaces, wherein each concentric spherical curved surface layer is formed according to different radii of the concentric spheres do.

In one embodiment, the modeling unit may further include three-dimensional closed loop loops formed by connecting intersections generated between the stereo lithography model and each of the concentric spheres having different radii from each other to the entirety of the concentric spheres. Dimensional spherical surface layer (spherical area layer) model.

In one embodiment, the work table includes a base table and a plate platform rotatably coupled on the base table.

In one embodiment, the rotation driving unit rotates the plate-type platform with the rotation axis orthogonal to the surface of the work table as a rotation axis, and rotates in a direction orthogonal to the rotation axis of the plate- And is further configured to tilting the base table.

In one embodiment, the control unit determines, based on the model specification of the three-dimensional printing apparatus, a minimum size of the attachment to be attached to the base material in the initial printing operation in order to prevent the nozzle from interfering with the plate- And an interference prevention unit configured to determine the interference.

A three-dimensional printing apparatus according to an exemplary embodiment of the present invention includes: a powder supply unit configured to supply metal powder to the nozzle; And a laser supply unit configured to generate the printing material to which the powder is sintered by irradiating a laser to the powder supplied to the nozzle.

According to an exemplary embodiment of the present invention, a three-dimensional printing method includes: determining a three-dimensional spherical surface layer model having a plurality of concentric spherical curved layers corresponding to a shape to be printed; And controlling the rotation of the work table and the movement of the nozzle so that the interface between the nozzle and the work table into which the printing material is injected corresponds to a part of the concentric spherical curved layer of the three- Lt; RTI ID = 0.0 > a < / RTI > printing material.

In the three-dimensional printing method according to an embodiment, each of the plurality of concentric spherical curved layers constituting the three-dimensional spherical laminate (spherical area layer) model has a shape of a part of concentric spheres having different radii, The spherical curved layer is continuously arranged in a direction in which the radius of the spherical portion increases around a fixed concentric point.

In one embodiment, the step of injecting the printing material may include a step of injecting the printing material in a direction in which the interface between the nozzle and the work table is sequentially positioned on the plurality of concentric spherical curved layers, And moving the nozzle with the nozzle.

In one embodiment, the step of determining the three-dimensional spherical lamellar (spherical area layer) model comprises determining the three-dimensional spherical lamination (spherical area layer) model based on the plurality of concentric And determining a radial difference between the spherical curved layers.

In one embodiment, the step of determining the three-dimensional spherical laminar (spherical area layer) model comprises the step of selecting the concentric spherical surface layer from an intersection between a stereolithographic model of the shape to be printed and a plurality of concentric spherical surfaces having a predetermined radius ; And generating the concentric spherical surface layer while changing the radius of the spherical surface.

In one embodiment, the step of creating the concentric spherical curved layer may include forming the concentric spherical curved layer by forming intersection points created between each of the plurality of concentric spherical surfaces having different radii from the stereolithographic model, (Spherical area layer) model by summing the three-dimensional closed-loop loops of the three-dimensional spherical surface loop.

The three-dimensional printing method according to an exemplary embodiment of the present invention is characterized in that the control unit controls the three-dimensional printing apparatus based on the model specification of the three-dimensional printing apparatus to prevent the nozzles from interfering with the plate- And determining the minimum size of the attachment to be attached.

A three-dimensional printing apparatus and method according to an aspect of the present invention includes determining a three-dimensional spherical laminate (spherical area layer) model corresponding to a shape to be printed and formed of a plurality of concentric spherical curved layers And to perform printing while controlling the rotation of the work table and the movement of the nozzles so that the interface between the nozzle for injecting the printing material and the work table forms a concentric spherical curved layer.

According to the three-dimensional printing apparatus and method according to one aspect of the present invention, overhang and / or overprinting can be achieved by laminating the printing material in the form of a concentric spherical curved layer through continuous and synchronized interaction between the nozzle and the workpiece When an undercut structure is stacked without a support structure, there is an advantage that a work delay can be prevented from occurring due to rotation of a workpiece, and a precise three-dimensional object can be printed at a high speed.

Further, according to the three-dimensional printing apparatus and method according to one aspect of the present invention, printing can be performed based on concentric spherical curved surface-based lamination technology which inherently prevents the nozzle from causing physical interference with the work table or the stack on the work table There is an advantage that the conventional general interference problem can be prevented.

Further, according to the three-dimensional printing apparatus and method according to one aspect of the present invention, in order to prevent the nozzle from interfering with the plate platform on the basis of the model specification of the three-dimensional printing apparatus, The minimum size of the adhering material to be adhered is calculated and printing is performed on the basis of the minimum size of the adhering material so that the interference problem caused by the inherent problem of the present method can be prevented in advance.

FIGS. 1A and 1B are conceptual diagrams illustrating a printing material stacking method using a conventional three-dimensional printing apparatus.
FIG. 2 is a conceptual diagram for explaining interference between a nozzle and a workpiece generated in a printing method stacking method using a conventional three-dimensional printing apparatus.
3 is a configuration diagram of a three-dimensional printing apparatus according to one embodiment.
4 is a conceptual diagram illustrating a stacking method using a three-dimensional printing apparatus according to one embodiment.
5 is a perspective view illustrating a work table of the three-dimensional printing apparatus according to one embodiment.
FIG. 6 is a conceptual diagram illustrating a process of generating a three-dimensional spherical laminate (spherical area layer) model composed of a concentric spherical curved layer in a three-dimensional printing apparatus according to an exemplary embodiment.
FIG. 7 is an image showing a three-dimensional spherical laminar (spherical area layer) model using a three-dimensional printing apparatus according to an embodiment compared with a conventional planar layer model.
FIG. 8 is a conceptual diagram for explaining the minimum size of an attachment adhered to a base material so as to prevent interference between a nozzle and a workpiece during a first printing operation in a three-dimensional printing apparatus according to an exemplary embodiment.
9 to 11 are images showing a three-dimensional spherical laminar (spherical area layer) model using a three-dimensional printing apparatus according to an embodiment in comparison with a conventional planar layer model for various shapes.
12 is a flowchart of a three-dimensional printing method according to an embodiment.

Hereinafter, some exemplary embodiments of the present invention will be described in detail with reference to the drawings.

Where reference in the specification to "above " another part, it may be directly on the other part or be accompanied by another part therebetween. In contrast, when a section is referred to as being "directly above" another section, no other section is involved.

Herein, the terms first, second and third, etc. are used to describe various parts, components, regions, layers and / or sections, but are not limited thereto. These terms are only used to distinguish any moiety, element, region, layer or section from another moiety, moiety, region, layer or section. Thus, a first portion, component, region, layer or section described below may be referred to as a second portion, component, region, layer or section without departing from the scope of the present invention.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular forms as used herein include plural forms as long as the phrases do not expressly express the opposite meaning thereto. Means that a particular feature, region, integer, step, operation, element and / or component is specified and that the presence or absence of other features, regions, integers, steps, operations, elements, and / It does not exclude addition.

The term " below ", "above ", and the like, which denote relative space in this specification, can be used to more easily describe the relationship to other parts of a part shown in the drawings. These terms are intended to include other meanings or acts of the apparatus in use, as well as intended meanings in the drawings. For example, when inverting a device in the figures, certain parts that are described as being "below" other parts are described as being "above " other parts. Thus, an exemplary term "below" includes both up and down directions. The device can be rotated 90 degrees or rotated at different angles, and the term indicating the relative space is interpreted accordingly.

Unless defined otherwise, all terms including technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Commonly used predefined terms are further interpreted as having a meaning consistent with the relevant technical literature and the present disclosure, and are not to be construed as ideal or very formal meanings unless defined otherwise.

3 is a configuration diagram of a three-dimensional printing apparatus according to one embodiment.

Referring to FIG. 3, the three-dimensional printing apparatus according to the present embodiment includes a work table 10 as a work space in which a printing material is injected and formed into a three-dimensional object, A rotation driving section 40 configured to rotate the work table 10 in at least one axial direction; a translation driving section 40 configured to move the nozzle 20 in a plurality of axial directions; And a control unit 50 for controlling the relative movement between the nozzle 20 and the work table 10 through the control of the rotation driving unit 40 and the translating driving unit 30. [

The translation drive 30 is configured to move the nozzle 20 in an axial direction perpendicular to the surface of the work table 10 and one or more axes parallel to the surface of the work table 10. For example, the translational driving unit 30 is configured to move the nozzle 20 to any one of x-axis and y-axis on the plane parallel to the surface of the work table 10 and z-axis orthogonal to the surface of the work table 10 Axis drive mechanism capable of moving the nozzle 20 in the direction of the arrow.

The rotary drive unit 40 drives the work table 10 to rotate in a direction perpendicular to the surface of the work table 10 For example, a < RTI ID = 0.0 > phi < / RTI > axis). Accordingly, the three-dimensional printing apparatus according to the embodiments has five axial degrees of freedom in that it can move in three axial directions of the nozzle 20 and rotate about two axes of the work table 10.

The control unit 50 controls the movement of the nozzle 20 and / or the rotation of the work table 10 through the translational driving unit 30 and the rotation driving unit 40, Dimensional object in which the interface between the nozzle 20 and the work table 10 becomes a part of the spherical surface instead of using the evaporation method in the direction determined through the 90-degree rotation of the nozzle 10 and the work table 10, Print. To this end, in one embodiment, the controller 50 includes a modeling unit 510 for generating a spherical-based three-dimensional spherical surface layer model corresponding to a three-dimensional shape to be printed.

4 is a conceptual diagram illustrating a stacking method using a three-dimensional printing apparatus according to one embodiment.

As described above with reference to Figs. 1A and 1B, the stacking of the printing material according to the prior art is made only in the vertical direction, and unlike the case where the extension direction of the object is changed by only 90 degrees rotation of the workpiece, In the embodiments of the present invention, a concentric spherical curved layer 400 corresponding to a part of a sphere having a constant radius from the central portion of the work table 10 is formed The printing material is laminated.

Although the shape of the concentric spherical curved layer 400 is shown in a state where the position of the work table 10 is fixed in the figure, the interface between the work table 10 and the nozzle in actual lamination is the surface of the concentric spherical curved layer 400 It will be readily appreciated by those of ordinary skill in the art that the printing material is deposited according to the shape of the concentric spherical curved layer 400 by rotating the work table 10 in one or more axial directions to move along the concentric spherical curved layer 400. When the spherical lamination model according to the present embodiment is used, since the point where the printing material is injected forms a continuous curved surface adjacent to the immediately preceding lamination position, a delay occurs in the process due to the discontinuous rotation of the work table .

5 is a perspective view illustrating a work table of the three-dimensional printing apparatus according to one embodiment.

5, in one embodiment, the work table 10 includes a base table 105 and a planar platform 100 that is rotatably disposed on the base table 105. As shown in FIG. For example, each of the base table 105 and the plate-like platform 100 may be made of metal, but is not limited thereto. The plate platform 100 can rotate with the rotation direction (i.e., the? Axis) of the direction of injection of the printing material through the nozzle, which is referred to herein as rotation. In addition, the base table 105 can be rotated in one direction orthogonal to the direction of injection of the printing material through the nozzles into the rotation axis (i.e., the? Axis), which is referred to herein as tilting. That is, the rotation driving unit 40 (FIG. 1) achieves the rotation degree of the work table 10 in the biaxial direction by causing the rotation of the plate-shaped platform 100 and / or the tilting of the base table 105.

At this time, the interface between the nozzle 20 and the work table 10 is located on the spherical surface having the center of rotation of the work table 10 and having a constant radius. Therefore, while controlling the rotation of the work table 10 and the movement of the nozzle 20 so that the specific position P on the spherical surface on which the printing material is to be deposited is positioned below the nozzle 20, The printing material can be deposited in a shape corresponding to the concentric spherical curved layer that is a part of the spherical surface by injecting the material.

FIG. 6 is a conceptual diagram illustrating a process of generating a three-dimensional spherical laminate (spherical area layer) model including a concentric spherical curved layer in a three-dimensional printing apparatus according to an exemplary embodiment.

In the three-dimensional printing apparatus according to the present embodiment, the modeling unit of the control unit determines a three-dimensional spherical surface layer (spherical surface layer) model corresponding to a shape to be printed and formed of a plurality of concentric spherical curved layers. For example, the modeling unit may preliminarily store stereolithograph model information of a three-dimensional object to be printed using an STL file or the like, or may receive this information, and may extract three (3) images on concentric spherical curved layers from the stereolithographic model, Dimensional spherical laminar (spherical area layer) model consisting of dimensional closed curves (loops).

)에 의하여 하기 수학식 1과 같이 정의될 수 있다. 6A, coordinates (x, y, z) on the concentric spherical surface layer constituting the three-dimensional spherical laminate (spherical area layer) model to be generated are represented by coordinates The radius r, the rotation angle θ of the work table, and the tilting angle

) ≪ / RTI >

6 (b), the modeling unit projects the stereolithographic model onto an arbitrary spherical surface to obtain a three-dimensional closed loop loop 600 (see FIG. 6A), which is concentric spherical surface lamination information formed from the intersection of the stereolithography model and the spherical surface ). In the embodiment shown in FIG. 6, a three-dimensional closed curve loop 600 formed by connecting the intersections of the stereo lithography model and the spherical surface is defined.

6 (c), the intersection of the spherical surface of each concentric sphere and the stereolithographic model with the radius of the spherical surface to project the stereolithographic model is set to be the concentric spherical surface Dimensional closed loop loop 600, which is stacking information. By repeating the above process, it is possible to obtain a three-dimensional closed loop loop 600, which is a plurality of concentric spherical surface laminate information continuously arranged in a direction in which the radius r of the spherical surface increases. That is, the stereo lithography model made up of the triangle information is converted into a three-dimensional spherical surface layer model composed of the three-dimensional closed curve loops 600, which are a plurality of spherical curved surface stacking information. However, the method of defining the concentric spherical curved surface layer of the three-dimensional model corresponding to the shape to be printed may be different or is not limited to the form shown in Fig.

FIG. 7 is an image showing a three-dimensional spherical laminar (spherical area layer) model using a three-dimensional printing apparatus according to an embodiment compared with a conventional planar layer model.

Fig. 7 (a) shows a three-dimensional model composed of planar layers arranged in only one direction as described above with reference to Fig. 1a, and Fig. 7 (b) Dimensional model so that the lamination directions implemented by the rotation of the work table include different planar layers. Meanwhile, FIG. 7C shows that a three-dimensional spherical surface layer (spherical surface layer) model is constituted by a plurality of spherical curved layers whose radii sequentially increase from the center of rotation according to the embodiment of the present invention.

Referring again to FIG. 3, the three-dimensional printing apparatus according to the present embodiment further includes at least one member for supplying the printing material to the nozzle 20. For example, when a three-dimensional printing apparatus uses a Directed Energy Deposition (DED) method, a three-dimensional printing apparatus includes a powder supply unit 70 and a nozzle 20, which are configured to supply metal powder to the nozzle 20, And a laser supply unit (60) configured to irradiate a laser to the powder supplied to the powder supply unit. The powder supplied by the powder supply unit 70 is heated by the laser so that the sintered powder is injected from the nozzle 20 into the work table 10 to form an object. In one embodiment, the three-dimensional printing apparatus further comprises a lens section 80 for focusing the laser irradiated by the laser supply section 60 onto the nozzle 20.

However, the three-dimensional printing apparatus according to the embodiments of the present invention is not limited to metal powder, and the three-dimensional printing apparatus according to the embodiments may use a thermoplastic solid filament in a hot- A fused deposition modeling (FDM) method of melt-spraying, or an apparatus for laminating printing materials in different ways.

In one embodiment, the work table 10 and the nozzle 20 are received in the chamber 1, and the atmosphere in the chamber 1 is controlled by the gas purifier 90. For example, the gas purifying section 90 may operate so as to keep the inside of the chamber 1 close to vacuum or to remove impurities that may affect the stacking of the printing material in the chamber 1.

In one embodiment, the control unit 50 of the three-dimensional printing apparatus includes an interference prevention unit 520. The interference prevention unit 520 is a unit for preventing the interference between the stack of the printing materials stacked on the work table 10 or the work table 10 and the stack of the printing material stacked on the work table 10 based on the three dimensional model determined by the modeling unit 510 It serves to determine the minimum size of the attachment to be attached to the base material during the initial printing operation to prevent physical interference.

FIG. 8 is a conceptual diagram for explaining the minimum size of an attachment adhered to a base material so as to prevent interference between a nozzle and a workpiece during a first printing operation in a three-dimensional printing apparatus according to an exemplary embodiment.

8, a and b represent the minimum thickness and length of the attachment for preventing interference between the nozzle and the workpiece, respectively, R represents the spherical radius of rotation of the work table, r represents the radius of the space occupied by the nozzle, H represents the distance between the center of the space occupied by the nozzle and the rotation center of the work table, and? Represents the tilting angle of the work table. In this case, h ≥ d + r, R ≥ d, and cos Ω = R / h.

The attachment of the three-dimensional printing apparatus according to the present embodiment is arranged to be attached to the base material at the initial printing operation, and the work table defined by the above-mentioned parameters and the spherical space created by the three- The minimum size is determined so that the spherical spaces do not overlap or interfere with each other. In one embodiment, the minimum thickness a and length b of the attachment are defined by the following equations (2) and (3), respectively.

9 to 11 illustrate an image representing a three-dimensional spherical laminate (spherical area layer) model (c) using a three-dimensional printing apparatus according to an embodiment in comparison with a conventional planar floor information model (a, b) to be.

9 (a), 10 (a) and 11 (a) show that a three-dimensional model is constituted by layers arranged in only one direction, and FIG. 9 (b) , 10 (b) and 11 (b) respectively show that the three-dimensional model is configured so that the lamination directions implemented by the rotation of the work table include different layers. 9C, 10C, and 11C illustrate an example in which the closed curves generated in the plurality of concentric spherical surface layers in which the radius sequentially increases from the rotation center point Dimensional spherical surface layer (spherical surface layer) model composed of the spherical surface layer (spherical surface layer).

Table 1 below shows the time required for printing the shape including the overhang structure, as shown in Figs. 9 to 11, with reference to Figs. 9 (b), 10 (b) and 11 (C), 10 (c), and 11 (c) of the present invention, as compared with the case of the prior art shown in FIG. In the case of the prior art and the embodiment, the lamination speed of the printing material was 20 mm / sec (s), and the thickness of each layer was 400 μm.

Process time (seconds) Conventional technology Example Time increment
(%) 9
Shape Size (mm)
108 x 118 x 330 Stacking time 1,332.3 1,368.8 2.7 Rotation time 8.6 N / A 10
Shape Size (mm)
100 x 100 x 78 Stacking time 970.5 984.1 1.4 Rotation time 25.3 N / A 11
Shape Size (mm)
261 x 135 x 270 Stacking time 1,500.2 825.1 -46.8 Rotation time 6.3 N / A

As shown in the table, in the case of a simple shape as shown in FIG. 9, the embodiment of the present invention increases the printing time rather than the conventional technique. However, as the shape becomes complicated as shown in FIG. 10, . In the case of the shape having an irregular overhang structure as shown in FIG. 11, the printing time can be greatly reduced by using the embodiment of the present invention.

12 is a flowchart of a three-dimensional printing method according to an embodiment.

12, the control unit of the 3D printing apparatus receives the shape information of the three-dimensional object to be printed (S1), and converts the received shape to intersections of the spherical surfaces of the concentric spheres having the predetermined shape and the predetermined shape Dimensional sphere lamination (spherical area layer) model formed by connecting closed curves (S2). For example, the shape information received at the control unit may be a stereolithographic model of a file having an STL extension. The control unit generates the concentric spherical curved layer from the intersection of each concentric sphere and the stereolithographic model while increasing the radius of the spherical surface for projecting the shape so that the three dimensional shape of the curved lines formed on the plurality of successively stacked concentric spherical curved layers (Spherical area layer) model is determined (S3). However, if stacking information is stored in advance in the 3D printing apparatus, some or all of the steps S1 to S3 may be omitted.

Next, the control unit of the three-dimensional printing apparatus controls one or more axes (e.g., the? Axis and / or the? Axis) of the work table so that the interface between the nozzle and the work table to which the printing material is supplied corresponds to the spherical curved layer of the three- (E.g., x-axis and / or y-axis) movement of the nozzle and / or center rotation and / or nozzle (S4). The control process described above can be performed by controlling the translational driving unit coupled to the nozzle and the rotational driving unit coupled to the working table. In this manner, while the rotation of the work table and the movement of the nozzle are controlled, the powder and the laser are supplied to the nozzle so that the sintered powder is printed on the work table (S5).

The above deposition process is repeated until the stacked material reaches the final thickness. That is, until the final thickness is reached, the controller raises the radius of the spherical surface corresponding to the concentric spherical surface layer (S7) by lifting the nozzle in the z-axis direction orthogonal to the surface of the work table in the unrotated state, (S4 to S5) on the concentric spherical curved layer having an increased radius. When the final thickness is reached, the printing process is terminated.

While the invention has been shown and described with reference to certain embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. However, it should be understood that such modifications are within the technical scope of the present invention. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

Claims (17)

A nozzle configured to inject a printing material;
A work table into which the printing material is injected by the nozzle;
A rotation driving unit configured to rotate the work table in at least one axial direction;
A translation drive configured to move the nozzle in at least one axis parallel to a surface of the work table and in an axial direction perpendicular to a surface of the work table; And
Dimensional spherical lattice (spherical area layer) model corresponding to a shape to be printed and having a plurality of concentric spherical curved layers, and controlling the rotation driving unit and the translational driving unit so that the interface between the nozzle and the working table And a controller configured to control rotation of the work table and movement of the nozzle to correspond to a portion of the concentric spherical curved layer.
The method according to claim 1,
Each of the plurality of concentric spherical curved layers has a shape of a part of concentric spheres having radii different from each other, and the plurality of concentric spherical curved layers are continuously arranged in a direction in which a radius of a sphere increases around a fixed concentric point Dimensional printing device.
3. The method of claim 2,
The control unit moves the nozzle by a predetermined distance in a direction in which the radius of the concentric circle increases so as to control the translational driving unit so that the interface between the nozzle and the work table is sequentially positioned on the plurality of concentric spherical curved layers A three-dimensional printing apparatus comprising:
3. The method of claim 2,
Wherein the radial difference between the plurality of concentric spherical curved layers is determined by a process variable called the lamination thickness of the material and is controlled based on an injection amount of the printing material through the nozzle.
3. The method of claim 2,
The control unit generates lamination information on the concentric spherical curved layer on each spherical surface from an intersection between a stereolithographic model of a shape to be printed and a plurality of concentric spherical surfaces having different radii, And a modeling unit configured to generate the three-dimensional spherical surface layer (spherical surface layer) model by repeating the steps of generating each of the concentric spherical curved layers according to different radii.
6. The method of claim 5,
Dimensional spherical surface layer (spherical surface layer) by summing the three-dimensional closed loop loops formed by connecting the intersections between the stereolithographic model and a plurality of concentric spherical surfaces having different radii, with respect to all of the concentric spheres, A three-dimensional printing apparatus further configured to generate a model.
The method according to claim 1,
Wherein the work table comprises a base table and a plate platform rotatably coupled on the base table.
8. The method of claim 7,
The rotation drive unit includes:
Wherein the platform is rotated about the rotation axis of the work table in a direction orthogonal to the surface of the work table,
Wherein the base table is further configured to rotate the base table with a rotation axis perpendicular to the rotation axis of the plate platform.
8. The method of claim 7,
Wherein the control unit is configured to determine a minimum size of the attachment to be adhered to the base material in order to prevent the nozzle from interfering with the plate platform in the initial printing operation based on the model specification of the 3D printing apparatus Dimensional printing device.
The method according to claim 1,
A powder supply unit configured to supply metal powder to the nozzle; And
And a laser supply unit configured to generate the printing material in which the powder is sintered by irradiating a laser to the powder supplied to the nozzle.
A control unit of a three-dimensional printing apparatus includes a step of determining a three-dimensional spherical surface layer model consisting of a plurality of concentric spherical curved layers corresponding to a shape to be printed; And
Wherein the control unit controls the rotation of the work table and the movement of the nozzle so that the interface between the nozzle into which the printing material is injected and the work table corresponds to a part of the concentric spherical curved layer of the three- And injecting the printing material into the three-dimensional printing method.
12. The method of claim 11,
Wherein each of the plurality of concentric spherical curved layers constituting the three-dimensional spherical laminate (spherical area layer) model has a shape of a part of concentric spheres having different radii, and the plurality of concentric spherical curved layers are fixed Wherein the three-dimensional printing method is continuously arranged in a direction in which a radius of a sphere increases around a concentric point.
13. The method of claim 12,
Wherein the step of injecting the printing material comprises moving the nozzle in a direction in which the radius of the sphere is increased so that the interface between the nozzle and the work table is sequentially positioned on the plurality of concentric spherical curved layers, Printing method.
13. The method of claim 12,
Wherein the step of determining the three-dimensional spherical lamellar (spherical area layer) model comprises the steps of determining the thickness of the plurality of concentric spherical curved layers And determining a radial difference.
13. The method of claim 12,
The step of determining the three-dimensional spherical laminate (spherical area layer)
Creating lamination information on the concentric spherical curved layer on each spherical surface from an intersection between a plurality of concentric spherical spheres having a predetermined radius and a stereolithographic model of a shape to be printed; And
And repeating the step of creating the concentric spherical surface layer while changing the radius of the spherical surface.
16. The method of claim 15,
Wherein the step of generating lamination information on the concentric spherical curved layer comprises the steps of: summing three-dimensional closed loop loops formed by connecting the intersections between a plurality of concentric spherical surfaces having radii different from each other with the stereolithographic model, Dimensional model of the three-dimensional spherical laminate (spherical area layer) model.
12. The method of claim 11,
The control unit determines a minimum size of the attachment to be attached to the base material in order to prevent the nozzle from interfering with the plate platform of the work table in the initial printing operation based on the model specification of the 3D printing apparatus ≪ / RTI > further comprising the steps of:

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