KR102332533B1 - Wire arc directed energy deposition 3d printing method for forming inner core and flattening outer surface - Google Patents

Abstract

An embodiment of the present invention provides a 3D printing method comprising: a step of preparing a pattern material for producing a printing object to be printed; a step in which a router processes the prepared pattern material for the production of the inner or outer surface pattern of the printing object to produce a first layer of the inner pattern or the outer pattern; a step in which a printing nozzle produces a first printing layer as stacking a printing filler material on one side of the first layer; a step in which the router produces a second layer by stacking a pattern material, processed into an inner or outer pattern equal to or different from that of the first layer, on the upper surface of the first layer in consideration of the shape of the printing object; and a step in which the printing nozzle stacks a second printing layer on the first printing layer as stacking a printing filler material on one side of the second layer. Therefore, the printing object having an inner core and a flattened outer surface can be produced.

Description

WIRE ARC DIRECTED ENERGY DEPOSITION 3D PRINTING METHOD FOR FORMING INNER CORE AND FLATTENING OUTER SURFACE

The present invention relates to a 3D printing method, and more particularly, to a wire arc direct energy deposition 3D printing method for forming an inner core and planarizing an outer surface.

A 3D printer is a device for producing a three-dimensional object, and it differentiates data about the shape of a three-dimensional object of a three-dimensional shape to generate data about a two-dimensional plane, and according to the generated data, it stacks materials layer by layer or cuts the material You can create three-dimensional objects.

One of the methods of manufacturing a three-dimensional sculpture of a metal material is to melt the filler metal and the base material with arc heat generated in the gap between the filler metal and the base material, attach them layer by layer, and stack them to manufacture the sculpture.

At this time, the base material is melted by arc heat during the lamination process and is concavely depressed. It has a temperature of about °C. Therefore, a very extreme temperature gradient is generated in the molten pool, and due to the rapid natural flow of the molten material in the molten pool and the movement of the molten pool according to the printing speed, the molten material generates waves, and at regular intervals on the printing surface. A wave-shaped ripple is formed.

That is, the conventional wire arc direct energy lamination metal 3D printing apparatus is a situation in which a separate surface processing is required to remove the ripple.

The technical problem to be achieved by the present invention is to create a pattern sculpture made of a plurality of laminates using a pattern material and a molding frame, and laminate a printing filler material on one side of each laminate, thereby forming an inner core and printing with a flat outer surface It is to provide a 3D printing method capable of producing a sculpture.

The technical problems to be achieved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by those of ordinary skill in the art to which the present invention belongs from the description below. There will be.

In order to achieve the above technical object, an embodiment of the present invention comprises the steps of preparing a pattern material for producing a printing sculpture to be printed, and a router, for producing a surface pattern inside or outside the printing sculpture, the Manufacturing a first layer of an inner pattern or an outer pattern by processing the prepared pattern material, and manufacturing a first printing layer as a printing nozzle laminates a printing filler material on one side of the first layer, the router A, in consideration of the shape of the printing sculpture, manufacturing a second layer by laminating a pattern material processed into the same or different inner pattern or outer pattern as the first layer on the upper surface of the first layer; The printing nozzle provides a 3D printing method comprising laminating a second printing layer on the first printing layer as the printing nozzle laminates a printing filler material on one side of the second layer.

In an embodiment of the present invention, the pattern material is a molding sand or mixed clay, and the step of preparing the pattern material includes the steps of injecting the molding sand into the molding frame, and the molding sand injected into the molding frame. compacting and drying the minced casting sand, or drying the mixed clay into a plate shape of a predetermined thickness, or sintering the mixed clay manufactured in the plate shape of the predetermined thickness at the set temperature may include

In an embodiment of the present invention, by using mixed clay for ceramics as a pattern material, the entire pattern sculpture having a hollow part having the same shape as the printing object inside is manufactured, and the thickness determined in consideration of the shape of the printing object to be printed After dividing by as much as each layer, as each layer of the divided pattern sculpture is stacked, the printing nozzle laminates the printing filler material in the hollow part, so that the printing sculpture can be printed.

In an embodiment of the present invention, after manufacturing the first layer, in order to laminate the second layer on the first layer, the router makes a position check mark or a fixed pin hole on the upper surface of the first layer. It may further include the step of forming.

In an embodiment of the present invention, the step of forming the location check mark further includes receiving coordinate information on the location check mark point, and the router receives the input location check mark point. In consideration of the coordinate information for , the display point for positioning may be formed on the upper surface of the first layer.

In an embodiment of the present invention, after the first printing layer is manufactured, the method further comprises the step of applying a binder to the first layer, and the manufacturing of the second layer includes: It can be laminated on the upper surface of one layer.

In an embodiment of the present invention, after the first printing layer is manufactured, the method further comprises inserting a part of a fixing pin for fixing the second layer into the fixing pin hole, wherein the second layer is Some fixing pins may be laminated on the top surface of the inserted first layer.

In an embodiment of the present invention, by removing the first layer and the second layer that are the inner pattern or the outer pattern, the printing sculpture including the first printing layer and the second printing layer can be obtained. .

According to an embodiment of the present invention, a patterned object made of a plurality of laminates is created using a pattern material and a molding frame, and a printing filler material is laminated on one side of each laminate, thereby forming an inner core and printing with a flat outer surface. You can create sculptures.

It should be understood that the effects of the present invention are not limited to the above-described effects, and include all effects that can be inferred from the configuration of the invention described in the detailed description or claims of the present invention.

1 is a flowchart illustrating a 3D printing method according to an embodiment of the present invention over time.
2 to 7 are reference diagrams sequentially illustrating a 3D printing method according to an embodiment of the present invention.
8 is a reference diagram illustrating a process of preparing a pattern material according to an embodiment of the present invention.
9 is a reference diagram illustrating a stratification method using mixed clay according to an embodiment of the present invention.

Hereinafter, the present invention will be described with reference to the accompanying drawings. However, the present invention may be embodied in several different forms, and thus is not limited to the embodiments described herein. And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

Throughout the specification, when a part is said to be “connected (connected, contacted, coupled)” with another part, it is not only “directly connected” but also “indirectly connected” with another member interposed therebetween. "Including cases where In addition, when a part "includes" a certain component, this means that other components may be further provided without excluding other components unless otherwise stated.

The terms used herein are used only to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In this specification, terms such as "comprises" or "have" are intended to designate that the features, numbers, steps, operations, components, parts, or combinations thereof described in the specification exist, but one or more other features It should be understood that this does not preclude the existence or addition of numbers, steps, operations, components, parts, or combinations thereof.

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

1 is a flowchart illustrating a 3D printing method according to an embodiment of the present invention over time. And, Figure 2 to Figure 7 is a reference diagram showing a 3D printing method according to an embodiment of the present invention in order, Figure 8 is to explain the process of preparing a pattern material according to an embodiment of the present invention It is a reference diagram shown.

The wire arc direct energy stacking 3D printing method according to an embodiment of the present invention is a method performed by the 3D printing system to produce a printing object to be printed. More specifically, it is a 3D printing method performed by the 3D printing system to produce a flattened printing sculpture. The 3D printing system of the present invention may include a 3D printing device and a router device for pattern material production.

Referring to FIG. 1 , in the 3D printing method according to an embodiment of the present invention, a pattern material for manufacturing a printing object to be printed may be prepared in step S110 first.

Here, the pattern material may be provided as molding sand or mixed clay for ceramics.

For example, when the pattern material of the present invention is prepared as a mixed clay for ceramics, the mixed clay is formed into a plate shape by composing a composition ratio of primary clay and secondary clay for ceramics of various properties according to the printing use, and drying it and a suitable temperature Pattern sculptures can be produced by unglazing and post-processing.

The molding sand of the present invention according to another embodiment of the present invention is a core sand, Portland cement, sodium silicate, special composite sand, kaolin or kaolin, A material selected from bentonite, ball clay, and alumina may be used alone or as a mixture of at least two or more, which is the characteristic (shape, size, use) of the printing object to be produced. can be selected according to According to one embodiment, it is preferable that the particle size of the core sand used in the present invention is 100 to 1000 μm. If the particle size of the core yarn is 1000 μm or more, the surface is somewhat rough, and if it is 100 μm or less, a fine surface can be realized.

Although not shown in the drawing, the step of preparing the pattern material according to an embodiment of the present invention (S110) is, after injecting the molding sand into the molding frame, compacting the molding sand injected into the molding frame, and drying the chopped molding sand Thus, the pattern material can be prepared by loading the dried casting sand onto the workbench of the 3D printing apparatus. It will be described later in more detail with reference to FIG. 8 .

Referring to Figure 8, the 3D printing method of the present invention can first inject the molding sand 100 as shown in Figure 8 (b) into the molded frame 200 prepared as shown in Figure 8 (a). have.

After injecting the molding sand 100 into the molding frame 200 as shown in (b) of FIG. 8, and then pressing and compacting the injection sand 100 using the roller 90 as shown in FIG. 8 (c), By drying, a molding sand can be prepared as a pattern material.

At this time, a separation prevention pin 201 for coupling with the molding sand may be provided on the inner wall of the frame of the molding frame 200 of the present invention so that the injected molding sand does not come out of the molding frame. The prevention pin 201 may firmly hold the molding sand so that the injected molding sand is not separated. In the present embodiment, although the modeling frame 200 is illustrated as having a rectangular shape, the present invention is not limited thereto, and may be provided in various shapes depending on the shape of the printing object to be produced, such as a circle, a hexagon, a triangle, and the like.

In another embodiment, the molding frame 200 of the present invention further includes a molding plate 203 forming a hollow part 205 in the molding frame 200, as shown in FIG. 8(d). can be configured. The molding plate 203 according to the present embodiment may include a hollow part 205 having a shape that matches the shape of the pattern object to be implemented, and the molding sand 100 is injected into the hollow part 205, so that the pattern The sculpture may be manufactured in a shape corresponding to the shape of the hollow part 205 .

As described above, the molding frame 200 of the present invention forms an external pattern on the pattern sculpture for planarization of the outer surface of the printing sculpture by the wire arc direct energy layer, thereby generating a ripple ( Ripple) can be improved, and dimensional accuracy can be increased.

The description with reference to FIG. 8 is an embodiment corresponding to the case where the pattern material is a molding sand, and in another embodiment of the present invention, when the pattern material is prepared with mixed clay for ceramics, the molding frame 200 as described in FIG. It is possible to produce a pattern sculpture of a desired shape without using it.

9 is a reference diagram illustrating a stratification method using mixed clay according to an embodiment of the present invention.

Referring to Figure 9, (a) of Figure 9 is a cross-sectional view of a pattern sculpture having a pattern for obtaining a printing sculpture, Fig. 9 (b) is a cross-sectional view of a pattern sculpture having a pattern for obtaining a printing sculpture divided into layers 9, (c) is a cross-sectional view in which the pattern sculpture as shown in (b) is divided into layers - a three-dimensional view, and FIG. 9 (d) is a view showing a printing sculpture.

The 3D printing method according to an embodiment of the present invention uses a mixed clay for ceramics as a pattern material, and a pattern sculpture 100 having a hollow portion 101 having the same shape as the printing sculpture inside as shown in FIG. 9 (a). After manufacturing the whole, and dividing each layer by a thickness determined in consideration of the shape of the printing sculpture to be printed, as shown in FIGS. 9 (b) and (c), each layer of the divided pattern sculpture 100 is stacked. Accordingly, by laminating the printing filler material on the hollow part 101 of the printing nozzle, the printing sculpture 300 as shown in FIG. 9(d) can be printed.

Referring back to FIG. 1, when the preparation of the pattern material (S110) is completed, in step S120, the router 30 processes the prepared pattern material for the production of an inner or outer surface pattern of the printing sculpture to form the inner pattern or the outer pattern. A first layer can be fabricated.

And, as the printing nozzle laminates the printing filler material on one side of the first layer based on the pattern material in step S130, the first printing layer may be manufactured.

Then, in step S140, in consideration of the shape of the printing sculpture to be printed by the router 30, as the pattern material processed into the same or different inner pattern or outer pattern as the first layer is laminated on the upper surface of the first layer, the second Layers can be crafted.

And, as the printing nozzle further stacks the printing filler material on one side of the second layer in step S150, the second printing layer may be stacked on the first printing layer.

And, by removing the first layer and the second layer, which are an inner pattern or an outer pattern based on a pattern material, for forming an inner or outer surface pattern of the printing sculpture in step S160, the first printing layer and the second printing You can obtain a printed sculpture made of layers.

In this embodiment, the printing sculpture to be printed has been illustrated and described as consisting of a first printing layer and a second printing layer, but the printing sculpture of the present invention is three or more printing layers depending on the size and shape of the object to be produced. It may be formed or may be formed of one printing layer. Likewise, it is obvious that the pattern sculpture may also be provided in one layer or two or more layers according to the number of printed layers to be implemented.

For example, each layer of the pattern sculpture according to the embodiment of the present invention may be formed to a thickness of 5 to 20 mm.

The 3D printing system for performing the 3D printing method according to an embodiment of the present invention may be configured to include a wire arc direct energy lamination 3D printing device and a router device. The router device according to this embodiment may be configured to include a router workbench 10, and a router 30, as shown in FIG. 2, and the 3D printing device according to this embodiment is as shown in FIG. Likewise, it may be configured to include a printing workbench 20 and a printing nozzle 50 . The 3D printing apparatus according to an embodiment of the present invention as shown in FIG. 4 may further include a position sensor 51 .

First, a router device will be described. The router workbench 10 of the router device is a component supporting a printing object to be manufactured, and is disposed at a predetermined interval below the router 30 and may be formed in a plate shape. For example, the router workbench 10 may be positioned on the XY plane formed by the X-axis and the Y-axis, or disposed in parallel with the XY plane. The Z axis may be referred to as an axis perpendicular to the XY plane. The XY plane may be referred to as a horizontal plane.

The router 30 is a device that performs a cutting operation of processing a pattern material in order to produce a patterned object that forms a pattern on the inner or outer surface of the printed object. The router 30 according to the embodiment of the present invention may be equipped with a milling cutter and an end mill, and the end mill according to this embodiment may form a pattern by processing the inside or the outside of the pattern material, and the milling cutter The surface of the patterned object can be processed smoothly. For example, when using mixed clay as a pattern material, the clay may be deformed during drying and unglazing of the clay. In this case, the milling cutter can flatten the surface of the patterned object based on the pattern material.

Next, a 3D printing apparatus will be described. The printing workbench 20 of the wire arc direct energy lamination 3D printing apparatus is a component supporting the printing sculpture and the pattern sculpture to be produced, and is disposed at a predetermined interval below the printing nozzle 50, and may be formed in a plate shape. have. For example, the printing workbench 20 may be positioned on the XY plane formed by the X-axis and the Y-axis, or may be arranged side by side with the XY plane. The Z axis may be referred to as an axis perpendicular to the XY plane. The XY plane may be referred to as a horizontal plane.

The printing nozzle 50 is located on the printing work bench 20 and is a device for manufacturing a printing object to be printed by stacking a printing filler material in a position adjacent to the pattern sculpture.

3 to 7, which are one embodiment, the printing nozzle 50 and the position sensor 51 are shown separately, but the printing nozzle 50 and the position sensor 51 according to an embodiment of the present invention are the printing workbench 20 ) and may be installed to be spaced apart from each other on the nozzle positioning member 70 installed in the longitudinal direction of the printing work bench 20 . For example, the nozzle positioning member 70 may be implemented to be movable not only in the XY direction but also in the Z direction.

2 to 7 , the router device includes a router position adjusting member 60 for adjusting the position of the router 30 , and the 3D printing device adjusts the positions of the printing nozzle 50 and the position sensor 51 . It may include a nozzle position adjusting member (70).

According to an embodiment, the router device of the present invention may be a 3-axis driving device, and the 3D printing device may be provided as a 5-axis driving device.

Hereinafter, the description with reference to FIGS. 2 to 7 is an embodiment of a process of manufacturing a printing sculpture using the molding frame 200 . 2 is a reference diagram illustrating a process of manufacturing a first layer according to an embodiment of the present invention.

See FIG. 2 . First, the router 30 may process the pattern material prepared through the process as described in FIG. 8 on the router workbench 10 to manufacture the first layer 110 of the inner pattern or the outer pattern of the pattern material. For example, the router 30 according to the present embodiment may form an inner pattern or an outer pattern by cutting the pattern material prepared on the router work table 10 .

Here, the inner pattern or the outer pattern means a pattern for forming a pattern on the inner or outer surface of the printing sculpture to be produced, and by laminating a printing filler material next to the first layer that is the inner pattern or outer pattern, the A printing sculpture having a pattern corresponding to the inner pattern or the outer pattern is formed.

In Fig. 2, which is an embodiment, the molding frame 200 serves as an external pattern of the patterned object for forming a pattern on the outer surface of the printing object, and the output of the router 30 processing the pattern material prepared in step S110 is printed. A pattern sculpture for forming a pattern of the inner surface of the sculpture may be serving as an inner pattern. In another embodiment of the present invention, as an external pattern of a pattern sculpture for forming a pattern on the outer surface of the printing sculpture, it is implemented as an external pattern produced by processing the pattern material, not the molding frame 200, by the router 30. may be

In this way, when the production of the first layer 110 of the patterned object is completed, the router 30 is formed of the first layer 110 in order to laminate the second layer 130 on the manufactured first layer 110 . A plurality of position confirmation marks 111 and a plurality of fixing pin holes 113 are formed on the upper surface.

The router 30 according to an embodiment of the present invention receives coordinate information for a position check mark generated from a cam (computer aided manufacturing), and is located on the upper surface of the first floor 110 based on the received coordinate information A check mark 111 may be formed. The position check mark 111 formed in this way serves to guide the pattern of the second layer 130 to be laminated later and the pattern of the first layer 110 so that the pattern can be accurately matched.

In addition, the router 30 according to the present embodiment may form the fixing pin hole 113 at a point different from the position check mark 111 . For example, the mark point 111 for positioning may be a point formed using ink, and the fixing pin hole 113 may be a hole generated by cutting the first layer 110 by a preset depth.

Then, the position sensor 51 determines a position to fix the first layer 110 in which the position check mark 111 and the fixing pin hole 113 are formed on the printing work bench 20, and a binder (for example, , ceramic bond) after fixing the first layer 110 at the determined position, as shown in FIG. 3 , the printing nozzle 50 laminates the printing filler material on one side of the first layer 110 , 1 A printing layer 310 may be manufactured.

The binder according to an embodiment of the present invention may be provided as a ceramic bond, and the use of such a binder may prevent the pattern from being pushed or lifted by arcs and molten metal.

As shown in FIG. 3, when the production of the first printing layer 310 is completed, as shown in FIG. 4, the position sensor 51 of the printing nozzle 50 confirms the point where the second layer 130 is located. , the inner pattern fixing pin 115 can be inserted. In addition, the position sensor 51 may further insert the external pattern fixing pin 213 after confirming a point where the external pattern 230 of the second layer is also located in the external pattern 210 of the first layer.

The position sensor 51 according to the embodiment of the present invention may be implemented as a laser position sensor that is a laser pointer using a laser. The position sensor 51 according to this embodiment may be installed in the same position as the printing nozzle 50, and the position sensor 51 may be changed so that the printing nozzle 50 does not interfere with the printing operation during the printing operation. can

Then, a binder is applied on the first layer 110 .

Referring to FIG. 5 , the second layer 130 generated through the operation as described in FIG. 2 is laminated on the first layer 110 to which the binder is applied. In addition, a second layer 330 of the outer pattern is laminated on the first layer 310 of the outer pattern.

The shape of the second layer 130 according to an embodiment may be the same as or different from that of the first layer 110 . The shapes of the first layer 110 and the second layer 130 may be determined according to the shape of each height of the printing sculpture to be printed.

When the production of the second layer 130 is completed, as shown in FIG. 6 , the printing nozzle 50 additionally applies a printing filler material to one side of the second layer 130 , and thus the second printing layer 330 . can be produced.

Referring to FIG. 7 , after the production of the second printing layer 330 is completed, the first layer 110 and the second layer ( As the pattern sculpture 100 of 130 and the outer pattern sculpture 200 of the first layer and the second layer are removed, there is no surface ripple and the first printing layer 310 in which a precise core is formed ) and the second printing layer 330 can be obtained to obtain a printing sculpture (300).

The left view of FIG. 7 is a view before flattening the upper surface of the printing sculpture 300 including the first printing layer 310 and the second printing layer 330, and the right view of FIG. 7 is the printing sculpture ( 300) shows the appearance after planarization of the upper surface.

In the description with reference to FIGS. 2 to 7, the printing sculpture 300 according to an embodiment of the present invention has been described as being generated as the first printing layer 310 and the second printing layer 330 are stacked. According to the shape of the printing sculpture 300 to be designed by those skilled in the art, it may be implemented as more printing layers are stacked. More specifically, it is possible to determine the number of layers to be laminated in consideration of a predetermined height (thickness) according to an external shape such as a curved portion, a protruding portion, a mirrored portion, etc. of the printing sculpture to be produced.

The 3D printing method according to an embodiment of the present invention may be performed using at least one technique of wire arc direct energy lamination, laser direct energy lamination, and powder bed fusion (PBF). More specifically, laser direct energy lamination and powder bed melting PBF techniques are superior to wire arc direct energy lamination in terms of surface roughness treatment effect because they use metal powder, so laser direct energy lamination and powder bed melting PBF techniques are used. more preferably.

The above description of the present invention is for illustration, and those of ordinary skill in the art to which the present invention pertains can understand that it can be easily modified into other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. For example, each component described as a single type may be implemented in a dispersed form, and likewise components described as distributed may be implemented in a combined form.

The scope of the present invention is indicated by the following claims, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present invention.

10: router workbench
20: printing workbench
30: router
50: printing nozzle
51: position sensor
60: router positioning member
70: nozzle positioning member
90: roller
100: foundry
200: molding frame
300: printing sculpture

Claims (7)

A step of preparing a pattern material for producing a printing object to be printed;
The router processing the prepared pattern material for the production of the inner or outer surface pattern of the printing sculpture to produce a first layer of the inner pattern or the outer pattern;
manufacturing a first printing layer as the printing nozzle stacks a printing filler material on one side of the first layer;
manufacturing a second layer by laminating, by the router, a pattern material processed into the same or different inner pattern or outer pattern as the first layer, on the upper surface of the first layer in consideration of the shape of the printing object; ,
Laminating a second printing layer on the first printing layer as the printing nozzle laminates a printing filler material on one side of the second layer,
The pattern material is a molding sand,
The step of preparing the pattern material,
injecting the molding sand into the molding frame;
compacting the molding sand injected into the molding frame;
3D printing method comprising the step of drying the chopped molding sand.
delete According to claim 1,
After manufacturing the first layer, the router further comprises the step of forming a mark point for positioning or a fixing pin hole on the upper surface of the first layer in order to laminate the second layer on the first layer Characterized by a 3D printing method.
4. The method of claim 3,
The step of forming the display point for positioning further includes the step of receiving coordinate information for the display point for positioning,
3D printing method, characterized in that the router forms the location check mark on the upper surface of the first layer in consideration of the received coordinate information on the location check mark point.
According to claim 1,
After the first printing layer is manufactured, further comprising the step of applying a binder to the first layer,
3D printing method, characterized in that the manufacturing of the second layer is laminated on the upper surface of the first layer to which the binder is applied.
4. The method of claim 3,
After the first printing layer is manufactured, the method further comprising inserting a part of a fixing pin for fixing the second layer into the fixing pin hole,
3D printing method, characterized in that the second layer is laminated on an upper surface of the first layer into which a part of the fixing pin is inserted.
According to claim 1,
3D printing method further comprising the step of obtaining the printing sculpture including the first printing layer and the second printing layer by removing the first layer and the second layer that are the inner pattern or the outer pattern.

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