KR101662894B1 - Printing bed for 3d printer, 3d printer having thereof and printing method - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a bed of a 3D printer in which printing sculptures are stacked, and a printing method using the same.
A bed for a 3D printer according to the present invention comprises a platform having a through hole spaced apart at regular intervals and a lift provided at a lower portion of the platform and having protrusions fitted in the through holes, The heat is transmitted to the protrusion formed on the lift, the heat emitted from the protrusion prevents the deformation of the molding that is laminated on the upper part of the protrusion, and the heat emitted from the protrusion which does not contact the molding protrudes by the convection, .

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a 3D printing bed,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a 3D printer, and more particularly, to a bed of a 3D printer in which printing sculptures are stacked, and a printing method using the same.

3D printing refers to the production of a variety of materials such as plastic, metal, and ceramics stacked on top of each other using a three-dimensional design scheme. 3D printers are classified according to the method of outputting the material, such as SLS (Selective Laser Sintering) method of laser-sintering the powdered material, SLA (Stereolithography) method of hardening the material by light, Fused Deposition Modeling) method is widely used.

1 shows a 3D printer of the FDM type. The 3D printer using the FDM method comprises a transfer head 100 moving in the XY axis direction, an extruder 200 mounted on the transfer head, and a bed 500, and the filament F is supplied to the extruder do. In the FDM method, filaments are discharged to form a designed shape while sequentially stacking from the bottom of the bed.

Referring to the drawings, filaments are wound on a supply reel and are guided from a pair of drive wheels (DW) mounted on a transfer head and supplied to an extruder. The melted filaments discharged from the nozzles formed in the extruder are sequentially stacked on the top of the bed.

3D printers which melt and laminate filaments mainly use thermoplastic plastic materials such as ABS or PLA as filaments. ABS is relatively stronger than PLA and is not only strong in heat but also inexpensive. However, there is a disadvantage in that the shrinkage due to heat during printing causes deformation of the molding. On the other hand, PLA is deformable due to thermal contraction due to heat shrinkage, which enables precise molding, but it has a disadvantage of low durability and high cost. In recent years, PLA-only products that do not use ABS have been introduced due to deformation caused by heat shrinkage.

However, as the size of the sculpture increases, the problem of thermal deformation still remains. For example, thermal deformation may occur during lamination, resulting in warping of the molding or separation of the molding from the platform. In order to solve such a problem, a heating element is mounted on a bed of a 3D printer and heated. When the bed is heated, the thermal difference between the upper side and the lower side of the molding product is reduced during the lamination, thereby preventing the molding from being separated from the platform. However, such a method has a problem in that a user may be burnt during stacking and wait until the temperature of the bed is lowered in order to separate the molding after the finishing is completed.

In the 3D printer capable of forming a multicolor product of Patent No. 10-1346704, a plurality of filaments are individually fed and then joined together into a single passage. Since the filaments are in a sufficiently preheated state, the FDM-type Provide a 3D printer. In the cartridge for the 3D printing semi-liquid sample material and the extrusion apparatus of the Laid-Open Publication No. 10-2014-0036285, a gas layer is filled in a part of the upper part of the cartridge, and a non-food semi-liquid material other than food material is filled in the lower part thereof. Provides a 3D printer with no water left.

It is an object of the present invention to provide a 3D printer bed having a structure capable of preventing deformation of a molding during molding and easily separating the molding from a bed after molding.

A bed for a 3D printer according to the present invention comprises a platform having a through hole spaced apart at regular intervals and a lift provided at a lower portion of the platform and having protrusions fitted in the through holes, The heat is transmitted to the protrusion formed on the lift, the heat emitted from the protrusion prevents the deformation of the molding that is laminated on the upper part of the protrusion, and the heat emitted from the protrusion which does not contact the molding protrudes by the convection, .

Further, an air hole is further provided between the projections of the lift.

In addition, the protrusions are formed with concavity and convexity, planar and concave-convex and concave depending on the degree of fitting into the through-holes.

Further, the engagement or disengagement of the through hole and the projection is achieved by moving the platform or moving the lift.

The protrusions are formed in a shape of a letter having a head portion and a bag portion coupled to the bottom of the head portion. The through hole has an upper through hole and a lower through hole, and a step is formed between the upper through hole and the lower through hole And the head portion is configured to be restricted in its downward movement by the step portion.

Further, the lower inlet of the through-hole may be narrow and the upper outlet may be wide or may form a step, and the protrusion may be formed to have the same size as the lower inlet.

Further, an air pump is further provided inside the 3D printer or below the lift.

A third aspect of the present invention is a method of printing comprising a first step of heating a lift, a second step in which a protrusion formed on the lift is fitted into a through hole of a platform, a third step in which a projection of the lift moves upward of the platform, And a fifth step of separating the protrusion of the lift from the through hole of the platform when the molding is completed.

In addition, the bed according to the movement of the third step may be formed with concavity and convexity, planar and embossed concave and convex depending on the degree of insertion of the projection into the through hole.

Further, the engagement or disengagement of the through hole and the projection is achieved by moving the platform or moving the lift.

In addition, before the second step, hot air flows out through a passage formed in the through hole, thereby raising the temperature inside the printer to form a printing atmosphere.

In addition, after the second step and after the fifth step, air is sucked through the passages formed in the through holes to remove foreign matter remaining in the 3D printer, the platform, and the through holes.

According to the present invention, it is possible to increase the contact area between the molding and the bed by forming through holes spaced at regular intervals on the platform, forming lifts with protrusions in the through holes, coupling them to each other, There is an advantage that separation of the molding objects can be prevented.

Further, after the printing is completed, the projections are moved from the through holes, thereby facilitating the separation of the molding from the bed.

In addition, the lift having the protrusions can serve as a heating element, thereby reducing the thermal deformation of the molding during the lamination.

1 shows a 3D printer of the FDM type.
2 illustrates a bed of a 3D printer according to an embodiment of the present invention.
3 is a view for explaining the shape and position of a bed according to the present invention.
4 illustrates a process of printing in a bed according to an embodiment of the present invention.
Figure 5 shows the separation of the sculpture from the bed without the pre-printing section.
Figure 6 shows various forms of the bed according to the invention.
FIG. 7 illustrates the thermal flow of a bed and a sculpture when forming a sculpture according to an embodiment of the present invention.
Figure 8 illustrates air flow in a bed in accordance with one embodiment of the present invention.

Hereinafter, a 3D printer bed according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. In addition, the size of each element or a specific part constituting the element in the drawings may be exaggerated, omitted or schematically shown for convenience and clarity of description.

First, the 3D printer according to the present invention comprises a transfer head moving in the X-Y axis direction, an extruder mounted in the transfer head, and a bed moving up and down in the Z axis, and the filament is supplied to the extruder.

The filament is supplied in the form of a wire. Examples of the material include ABS, PLA, PC, PVA resin and the like. However, resin, ceramic, metal, or new material having suitable physical properties may also be used.

The transfer head may support the extruder and move horizontally in the X and Y axes. This movement is made by the horizontal drive unit. Further, a pair of drive wheels DW are provided on one side of the transfer head to guide the filament F by an extruder.

The extruder includes a nozzle for discharging the filament, a nozzle body integrally coupled to the nozzle at the upper end of the nozzle, and a heat block for heating the filament.

The bed is elevated in the Z-axis direction. The vertical movement can be raised or lowered by the vertical driving unit. On the other hand, lamination is performed on the bed. As the build-up of the molding proceeds, the bed rises. In the present invention, the bed is raised as the lamination is performed. However, the present invention is not limited thereto, and the present invention can be applied to a method in which the nozzle portion is lifted and laminated.

2 illustrates a bed of a 3D printer according to an embodiment of the present invention.

Referring to the drawings, a bed 500 includes a platform 510 having a through hole 511 spaced apart at a predetermined interval, a lift 520 installed at a lower portion of the platform and having a projection 521 fitted in the through hole, . Further, a heating element may be added to the lift to apply heat to the protrusion at a temperature desired by the user. Thus, the lower portion of the molding can maintain the temperature desired by the user. The shape of the protrusion may be various shapes such as a cylinder, a square column, and the shape of the through hole is preferably the same size and the same shape corresponding to the protrusion, but is not limited thereto. In addition, roughness may be added to the upper surface of the protrusion in order to widen the contact area with the molding.

On the other hand, an air pump may be provided inside the 3D printer or below the lift. An air hole may be formed in the portion where the projection is not formed in the lift. The air pump and the air hole will be described later in the description of the air flow.

The protrusion of the lift is inserted into the through hole of the platform. When the lift is raised, the protrusion moves upward in the through hole. When the lift is lowered, the protrusion moves in the downward direction of the through hole. Such a combination of the through hole and the projection may be achieved by movement of the lift or movement of the platform.

3 is a view for explaining the shape and position of a bed according to the present invention.

3 (a) shows a platform to which no lift is attached, and the upper part of the bed has a concavo-convex shape at regular intervals. According to this construction, when the molding is stacked on the upper part of the platform, the bottom surface of the molding is formed into a concave-convex shape. Therefore, the molding does not easily flow during molding.

Figures 3 (b) to 3 (d) illustrate a bed having a separate structure according to the present invention. The bed is formed of a platform and a lift, and a separate heating means is installed in the lift, and the protrusion formed on the upper side of the lift can maintain a constant temperature desired by the user.

Fig. 3 (b) shows a concavo-convex shape of a depressed shape in which a protrusion of a lift is fitted into a through hole of a platform. The shape of the through hole is preferably the same size and the same shape corresponding to the protrusion, but not limited thereto, and a space is formed between the through hole and the protrusion so that a part of the filament flows into the spacing space to widen the contact surface area between the molding and the bed .

Fig. 3 (c) is a horizontal plane in which the upper surface of the platform and the upper surface of the protrusion are free from irregularities as the projection of the lift rises to the through hole of the platform. In the case of horizontal formation without forming irregularities, there is no expansion of the contact surface between the molding and the bed, but thermal deformation of the molding can be prevented due to the temperature of the projection.

3 (d), the protrusion of the lift is further raised to the through hole of the platform, and the protrusion is protruded to the upper side of the upper surface of the platform. Thus, irregularities having a relief shape are formed.

As described above, the protrusion of the lift can be raised or lowered to form the embossing projection or the engraving projection on the through hole of the platform, which enlarges the contact surface area of the molding and the bed. Also, the upper surface of the platform and the upper surface of the protrusion may be formed to have the same horizontal surface.

Hereinafter, printing on the thus formed bed will be described.

4 illustrates a process of printing in a bed according to an embodiment of the present invention.

Referring to FIG. 4 (a), before printing is performed, the platform remains fixed, and the lift moves from the lower side to the upper side where the platform is located. Then, the protrusion of the lift is inserted into the through hole of the platform, so that the platform and the lift are mutually coupled (see Fig. 4 (b)).

At this time, the lift is heated, the temperature rise of the lift can be heated before the lift movement, can be heated simultaneously with the lift movement, and can be heated before printing after joining with the platform. And since the temperature rise is gradual, it is preferable that the lift start before the lift, continue to rise while moving, and then end with the platform in combination.

In Fig. 4 (c), when the protrusion of the lift protrudes to the upper surface of the platform, it forms a relief concave / convex, and a preprinting portion can be formed on the top of the bed. This makes it possible to produce better quality sculptures. The pre-printing unit is preferably formed somewhat wider than the printed area of the molding in consideration of the size of the finished molding. The height of the pre-printing portion may be the same as the height of the projection projecting from the platform. Accordingly, the lower part of the sculpture can be perfectly leveled. Here, the pre-printing unit is a part formed at a lower portion of the designed molding, and the printing unit is formed in this portion, and then the pre-printing unit is cut from the molding to complete the desired molding.

4 (d), a filament is laminated on the top of the pre-printing portion to form a molding. When the molding is stacked, the combined platform and lift can move in the Z axis at the same time, and the nozzle can move in the Z axis in the fixed state. On the other hand, during the molding, melted filaments are laminated on the upper part of the bed. When the lamination is further progressed, the lower part of the laminated molding gradually becomes lower in temperature and hardens. Such curing causes a temperature difference with the upper part in the course of lamination, and deformation of the molding can occur. Accordingly, the temperature change of the entire molding can be reduced by applying heat to the projections of the lift.

In Fig. 4 (e), when the molding is finished, the lift is lowered from the platform. When the protrusion of the lift is lowered, a hole corresponding to the protrusion is formed in the pre-printing portion. Accordingly, the pre-printing unit and the completed molding can significantly reduce the contact surface with the platform, and the pre-printing unit can be easily removed from the completed molding. In the present invention, a platform, not a lift, may be moved to couple and separate the platform and the lift, and the two plates may move at the same time.

In the above embodiment, the preprinting portion may be formed to form a flat surface without forming concavities and convexities in the lower portion of the completed molding. It is also possible to stack without forming a pre-printing portion.

Figure 5 shows the separation of the sculpture from the bed without the pre-printing section.

FIG. 5 (a) shows a finished product by laminating filaments without forming a pre-printing portion. When the molding is completed, the protrusion of the lift can be lowered from the platform to separate the molding from the bed (see Fig. 5 (b)). In addition, as shown in Fig. 5 (c), the protrusion of the lift can be raised to separate the molding from the upper surface of the platform.

At this time, the lift can be raised or lowered to reduce the contact surface between the molding and the platform, thereby easily separating the molding from the platform.

Figure 6 shows various forms of the bed according to the invention.

6 (a), a through hole is formed in the platform, and a protrusion is integrally formed on the lift. In contrast, FIG. 6 (b) shows that the lift and the projection are formed separately and joined together.

The through holes according to the embodiments of Figs. 6 (c) and 6 (d) are formed differently from the shapes of the projections. FIG. 6 (c) shows a funnel shape with a lower inlet of the through-hole being narrow and an upper outlet being wide, and FIG. 6 (d) shows a stepped portion inside so that the lower inlet of the through hole is narrower and the upper outlet is wider. 6 (c) and 6 (d) are formed so that the size of the narrow inlet of the through hole and the size of the protrusion are the same, and a space portion is formed on the upper side in a state where the through hole and the protrusion are engaged. A part of the filament may be filled in the space portion.

The bed according to the embodiment of Fig. 6 (e) has many differences from the shapes of Figs. 6 (c) and 6 (d) shown above. The through-hole of the platform has an upper through-hole 511-1 and a lower through-hole 511-3 which are wide at the upper portion and narrow at the lower portion, and have a step portion 511- 2 are formed. In other words, when the platform is viewed from above, a narrow through hole is seen inside the upper through hole having a large size.

Fig. 6 (f) is an enlarged view of a part of Fig. 6 (e). The projection of the lift is in a T shape and has a head part 521-1 and a bag part 521-2 which is engaged under the head part. The projections are positioned on the upper side of the platform in correspondence with the upper through holes, and then inserted into the narrow lower through holes. The head portion 521-1 of the projection of the 'T' is limited to the step portion 511-2 and is not moved further downward. The projections then interconnect with the lift to complete the bed. In Fig. 6 (e), the protrusions are separately fabricated and coupled to the lift, but may also be structurally integrated with the lift. In other words, in the present invention, the projections may be configured to be combined with or separated from the lift, and may have various shapes by being combined with or separated from the platform.

FIG. 7 illustrates the thermal flow of a bed and a sculpture when forming a sculpture according to an embodiment of the present invention.

Referring to the drawings, protrusions are projected from an upper surface of the platform, with protrusions of a lift fitted in the through holes of the platform. The pre-printing unit may be formed at the protrusion height of the protrusion, and a filament is stacked on the pre-printing unit to form a molding.

A heating element is coupled to the lift, and the heating element may be formed inside the lift, or a heating element may be added to the outside of the lift to transmit heat to the lift. The heat of the lift is transferred to the protrusion, and the transferred heat is emitted from the surface of the protrusion protruding from the platform. The heat transferred to the protrusion through the lift not only prevents the thermal deformation of the molding that is in contact with the protrusion but also releases heat into the air through the protrusion that is not in contact with the molding, It is possible to raise the overall internal working temperature. The increase in the internal temperature of the 3D printer due to the convection can reduce the thermal deformation of the entire molding. On the other hand, no additional heating element is added to the platform.

Figure 8 illustrates air flow in a bed in accordance with one embodiment of the present invention.

8 (a) shows a process of removing foreign matter before and after printing. At this time, the through hole of the platform is separated from the projection of the lift. In addition, a separate air pump is formed inside the 3D printer and below the lift. When the air pump operates, a flow of air is generated in the through holes of the platform. As a result, foreign materials remaining in the 3D printer, the upper part of the platform, and the through holes are removed.

8 (b) and 8 (c) show the air flow in the bed according to FIG. 7 (e), and FIG. 8 (b) shows the state before the printing.

Referring to the drawings, the projection of the lift protrudes to the upper side of the platform, and a passage is formed between the lower side of the T-shaped projection and the through hole of the platform. When the passage is formed as described above, the air pump discharges hot air, and the 3D printer is heated before printing, so that printing can be normally performed. Of course, such hot air leaking has an effect of preventing the thermal deformation of the molding by heating the entire molding during lamination.

In the present invention, hot air is used as an example, but not only a gas such as air but also a liquid can be moved. For example, the liquid of the adhesive component for contacting the laminated filament and the platform can be configured to move through the passageway.

And Fig. 8 (c) is a view showing suction of air during printing.

The flow of air by such an air pump (not shown) can be performed before or after printing. And may optionally be carried out for the printing atmosphere or as necessary for the removal of foreign matter. The air pump may be installed inside the 3D printer or under the lift, and the air may be sucked through the air holes 522 formed between the projections of the lift. Accordingly, the air flows directly to the air hole 522 through the through hole 511, so that the suction force is not lowered.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the present invention is not limited to the disclosed exemplary embodiments, but various changes and modifications may be made by those skilled in the art without departing from the scope of the present invention.

100: Feed head
200: extruder
500: Bed
510: Platform
511: Through hole
511-1: upper through hole
511-2:
511-3: Lower through hole
520: Lift
521: projection
521-1: Head
521-2:
522: Air hole
DW: Drive wheel
F: filament
PP: Preprinting
M: Sculpture

Claims (13)

As a bed for 3D printers,
The bed
A platform having through holes spaced at regular intervals,
A lift installed at a lower portion of the platform and having protrusions fitted in the through holes,
And an air pump provided at a lower side of the lift,
The engagement or disengagement of the through-hole and the projection is achieved by the movement of the platform or the movement of the lift,
The lift is heated and the heat is transferred to the protrusion formed on the lift, and the heat emitted from the protrusion prevents the deformation of the molding, which is laminated on the top of the protrusion,
Wherein the foreign matter remaining in the upper portion of the platform and the through holes is removed by a flow of air generated in the through holes by the air pump before or after printing.
As a bed for 3D printers,
The bed
A platform having through holes spaced at regular intervals,
And a lift installed at a lower portion of the platform and having protrusions fitted in the through holes,
The engagement or disengagement of the through-hole and the projection is achieved by the movement of the platform or the movement of the lift,
Said projection being T-shaped with a head portion and a bag portion coupled under the head portion,
The through hole has an upper through hole and a lower through hole. A step is formed between the upper through hole and the lower through hole. The head is configured to be restricted from moving downward by the step,
Wherein the lift is heated and the heat is transferred to the protrusion formed on the lift, and the heat emitted from the protrusion prevents deformation of the molding that is laminated on the upper portion of the protrusion.
As a bed for 3D printers,
The bed
A platform having through holes spaced at regular intervals,
A lift installed at a lower portion of the platform and having protrusions fitted in the through holes,
And an air pump provided at a lower side of the lift,
The engagement or disengagement of the through-hole and the projection is achieved by the movement of the platform or the movement of the lift,
Said projection being T-shaped with a head portion and a bag portion coupled under the head portion,
The through hole has an upper through hole and a lower through hole. A step is formed between the upper through hole and the lower through hole. The head is configured to be restricted from moving downward by the step,
The foreign matter remaining in the upper portion of the platform and the through hole is removed by the air flow generated in the through hole by the air pump before or after printing,
Wherein the lift is heated and the heat is transferred to the protrusion formed on the lift, and the heat emitted from the protrusion prevents deformation of the molding that is laminated on the upper portion of the protrusion.
A 3D printer comprising a bed according to any one of claims 1 to 3.
There is provided a printing method using a bed including a platform having a through hole spaced apart at regular intervals, a lift provided at a lower portion of the platform and having protrusions fitted in the through holes, and an air pump provided at a lower side of the lift ,
The engagement and disengagement of the through-hole and the projection are achieved by the movement of the platform or the movement of the lift,
During printing, the lift is heated, the heat is transferred to the protrusions formed in the lift, and the heat released from the protrusions prevents deformation of the molding, which is laminated on top of the protrusions,
The foreign matter remaining in the upper portion of the platform and the through holes is removed by the flow of air generated in the through holes by the air pump before or after printing.



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