KR102445729B1 - Reconfigurable print bed for 3D printers - Google Patents

Abstract

A print bed according to the present invention comprises: a base unit that is formed to face a sculpture to be 3D printed; and a plurality of sub-beds that are formed to move with respect to the base unit, wherein the sub-beds can move to a set position corresponding to a position close to the sculpture to be printed on the base unit by a set distance.

Description

Reconfigurable print bed for 3D printers

The present invention relates to a bed for supporting a work object in a 3D (three-dimensional) printer, a 3D printer equipped with the bed, and a method for controlling the bed.

In the existing 3D printing, additional production time is consumed for the modeling of the supporter.

In the case of an urgent need, such as a skull depression, a technology that can reduce the time required to shape the supporter of the implant is required. In addition, in 3D printing using a powder material, a large amount of material is required to fill the powder bed, and among these, the amount of material actually used for the production of a sculpture is not large. Therefore, there is a need for a technology that can increase the efficiency of material use by reducing wasted powder.

Korean Patent Application Laid-Open No. 2018-0052225 discloses a technique for dividing a processing chamber in which 3D printing is performed into a plurality of pieces, and controlling the internal volume size of the processing chamber according to the size of a 3D printed product.

Korean Patent Publication No. 2018-0052225

An object of the present invention is to provide a print bed and a method for controlling the same, which can reduce the time for forming a sculpture and reduce the amount of material consumed for molding the object.

The print bed of the present invention includes a base formed to face the three-dimensionally printed object; and a plurality of sub-beds movably formed with respect to the base part, wherein the sub-beds may move to a set position corresponding to a position close to the sculpture to be printed on the base part by a set distance.

The print bed of the present invention includes a molding plate disposed to face a three-dimensionally printed object, and a plurality of sub-beds that individually move up and down are provided on one surface of the molding plate facing the sculpture, and the sub-bed comprises: The molding plate having a shape that protrudes or is depressed with respect to the sculpture through the vertical movement and is coupled to one surface of the sculpture by the protrusion or depression of each sub-bed may be formed.

The control method of the present invention includes: acquiring shape data of a sculpture; determining the posture of the sculpture based on at least one of the number of supporters supporting the sculpture or the consumption of powder corresponding to the material of the sculpture; moving a plurality of sub-beds to a set position close to the sculpture by a set distance according to the posture of the sculpture; Each time one layer of the sculpture is printed, lowering the sub-bed, which has moved to the set position, by the thickness of the one layer; may include.

The variable print bed for a 3D printer proposed by the present invention is composed of a plurality of sub (sub) molding plate modules that can individually move up and down. By adjusting the sub-bed corresponding to the sub-modeling plate module, a molding plate tailored to the shape of the object may be provided.

If the object is printed on the molding plate that matches the shape of the object, the completion time of the object can be shortened and the amount of material consumed for molding the object can be reduced.

Compared with the existing plate-shaped molding plate of the present invention, at least a part of the print bed may be raised or protruded from the position of the existing molding plate in close contact with the bottom surface of the object. In this case, the amount of material consumption can be reduced by the volume raised or protruded from the existing molding plate. Alternatively, the length of the supporter may be shortened by the length rising or protruding from the existing molding plate. Reducing the length of the supporter may mean that the time required to form the supporter is reduced and the amount of material consumed for forming the supporter is reduced.

Finally, using the print bed of the present invention, it is possible to quickly 3D print a sculpture while using a small amount of material.

The print bed of the present invention may include a plurality of sub-beds that move independently of each other. The plurality of sub-beds must be lowered together while being fixed to each other in the process of descending as much as the stacking thickness of the material during the printing process after reaching their respective set positions in accordance with the sculpture. The print bed of the present invention may present an environment that satisfies the corresponding condition.

In addition, the print bed of the present invention can also provide a method of closing a gap between each sub-bed generated in the process of splitting a single print bed into a plurality of sub-beds.

In addition, when the three-dimensional shape data of the sculpture is input to the print bed of the present invention, the optimal posture of the sculpture can be extracted in consideration of the number of supporters and the amount of consumed materials. The posture of the sculpture may be affected by the movement position of the sub bed, and the print bed of the present invention uses the relationship between the posture of the sculpture and the sub bed to extract the posture of the sculpture that minimizes the number of supporters or material consumption. can

If the sculpture is printed in the corresponding posture, the additional time consumed for the creation of the supporter can be minimized or the amount of material consumed for the creation of the sculpture can be minimized.

By using the print bed of the present invention, the 3D molding time of implants that require urgency can be significantly reduced.

1 is a schematic diagram showing a print bed of the present invention.
2 is a schematic diagram showing a print bed of a comparative example.
3 is a schematic diagram showing a sub-bed of the present invention.
4 is a schematic diagram showing a shift unit.
5 is a schematic diagram showing the operation of the posture unit.
6 is a schematic diagram showing another print bed of the present invention.
7 is a schematic diagram showing another print bed of the present invention.
Fig. 8 is a schematic diagram showing the actuator of the first embodiment.
9 is a schematic diagram showing an actuator of the second embodiment.
Fig. 10 is a schematic diagram showing an actuator of the third embodiment.
11 is a schematic diagram showing the gas atmosphere inside the chamber in which the sculpture is 3D printed.
12 is a schematic view showing a first sealing portion of an embodiment.
13 is a schematic view showing a second sealing portion of another embodiment.
14 is a flowchart illustrating an automatic control method of a print bed.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art to which the present invention pertains can easily implement them. However, the present invention may be embodied in several different forms and 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.

In this specification, duplicate descriptions of the same components will be omitted.

Also, in this specification, when a component is referred to as 'connected' or 'connected' to another component, it may be directly connected or connected to the other component, but other components in the middle It should be understood that there may be On the other hand, in the present specification, when it is mentioned that a certain element is 'directly connected' or 'directly connected' to another element, it should be understood that the other element does not exist in the middle.

In addition, the terms used herein are used only to describe specific embodiments, and are not intended to limit the present invention.

Also in this specification, the singular expression may include the plural expression unless the context clearly dictates otherwise.

Also, in this specification, terms such as 'include' or 'have' are only intended to designate that the features, numbers, steps, operations, components, parts, or combinations thereof described in the specification exist, and one or more It should be understood that the existence or addition of other features, numbers, steps, acts, components, parts, or combinations thereof, is not precluded in advance.

Also in this specification, the term 'and/or' includes a combination of a plurality of listed items or any of a plurality of listed items. In this specification, 'A or B' may include 'A', 'B', or 'both A and B'.

Also, in this specification, detailed descriptions of well-known functions and configurations that may obscure the gist of the present invention will be omitted.

1 is a schematic diagram showing a print bed of the present invention.

The print bed shown in FIG. 1 may include a base unit 110 , a plurality of sub-beds 130 , and a printing unit 10 .

The base part 110 may be formed to face the three-dimensionally printed object 30 . The base part 110 is supported on the ground and may support a plurality of sub-beds 130 . The base unit 110 may include the chamber itself in which the sculpture 30 is accommodated, the bottom surface of the chamber, the sidewall surface, the ceiling, or the like, or may include a separate pedestal installed on the floor inside the chamber, a heat sink, and the like. For example, the base 110 shown in FIG. 1 may include a bottom surface supporting the sculpture 30 in a 3D (three-dimensional) printer of a PBF (Powder Bed Fusion) method. In addition, the print bed of the present invention may be applied to various methods such as a stereolithography (SLA) method and a fused deposition modeling (FDM) method.

In the PBF method, a metal powder (plastic powder, etc.) material 90 is horizontally spread in a very thin layer on a powder bed 50 using a roller 20, and a high-power industrial laser or electron beam is applied. It is a technology of selectively irradiating a model to be molded and sintering or melting it to perform additive manufacturing.

Since the price of the powder corresponding to the metal powder material 90 is high, in the PBF method, the supply means 70 for supplying the powder and the recovery means 80 for recovering the used powder are of high importance. Although there is a problem of powder management, the PBF method has an advantage in that it is possible to obtain a sculpture 30 of very good quality that almost follows the outer shape of the input shape data as it is compared to other printing methods.

The plurality of sub-beds 130 may be formed to be movable with respect to the base part 110 . For example, an actuator 139 such as a motor providing physical power, a hydraulic cylinder 133 , a pneumatic cylinder 133 , a hydraulic pump, and a pneumatic pump may be provided. The actuator 139 may be fixedly installed on the base part 110 . The sub-bed 130 facing the sculpture 30 may be provided at the end of the piston rod 132 , gear, arm, etc., which are moved by the actuator 139 . For example, when the columnar part 131 connected to the piston rod 132 is provided, the sub-bed 130 may be provided at an end of the columnar part 131 . In a state in which the plurality of sub-beds 130 are closely arranged, the direction of movement of the pillars 131 of a specific sub-bed may be guided by the pillars 131 of other sub-beds.

As a result, the sub-bed 130 moves based on the actuator 139 fixedly installed on the base 110, or is fixedly installed on the base 110 and transmits the power of the actuator 139 to the sub-bed 130. It can move based on a link part such as a gear.

The sub-bed 130 may move to a set position p corresponding to a position close to the sculpture 30 to be printed on the base unit 110 by a set distance. For example, when the sculpture 30 to be printed is determined, the sub-bed 130 may move from the initial position p0 in a direction closer to the sculpture 30 . The setting position p may be determined within the range of motion of the sub-bed 130 . For example, when the sub-bed 130 is formed to be capable of linear motion along the direction of gravity, the setting position p may be set as a point on the linear motion path of the sub-bed 130 .

When the sub-bed 130 moving toward the sculpture 30 reaches a set position p spaced apart by a set distance from one surface of the sculpture 30, it may stop moving and stop at the set position p.

The printing unit 10 may print the sculpture 30 on the sub-bed 130 in a state where the sub-bed 130 moved to the set position p is stopped at the set position p. The printing unit 10 is a laser generator 11 for generating a laser beam for processing the material 90 of synthetic resin or metal, a controller for controlling the path of the laser beam emitted from the laser generator 11 ( 13) may be included. The adjuster 13 may include a galvano scanner, a deflecting lens, or the like.

The plurality of sub-beds 130 may serve as a support plate supporting the base unit 110 in the direction of gravity. The printing unit 10 for printing the sculpture 30 is a supporter 40 that connects the sub-bed 130 and the sculpture 30 instead of directly printing the sculpture 30 on the sub-bed 130 corresponding to the support plate. can be printed first. The printing unit 10 may print the sculpture 30 at the end of the supporter 40 extending toward the sculpture 30 when the supporter 40 is completed.

In order to withstand the weight of the sculpture 30 acting in the direction of gravity, the supporter 40 may be formed in a bar shape extending along the direction of normal gravity. The supporter 40 may be an element to be removed from the sculpture 30 after the printing of the sculpture 30 is completed. In order to reduce the amount of material 90 consumed in the supporter 40 , the supporter 40 may be formed in a thin rod shape. In order to support the sculpture 30 having a diameter, thickness, and width more than hundreds of times that of the supporter 40 by using the supporter 40 having a small diameter, the supporter 40 may be formed in plurality. Both ends of the supporter 40 have a plurality of filaments 41 thinner than the body 43 of the supporter 40 so that the supporter 40 can be easily removed from the completed sculpture 30 and the sub-bed 130 . may be branched and connected to the sculpture 30 or the sub-bed 130 .

The supporter 40 may be formed by the printing unit 10 in the same manner as the sculpture 30 . If a lot of printing time is devoted to the sculpture 30 to be removed after completion of the sculpture 30, the total printing time of the sculpture 30 may be increased. In addition, the amount of material 90 wasted due to the sculpture 30 may be increased.

For example, if the sub-bed 130 in FIG. 1 forms the supporter 40 extending along the direction of gravity in a state located at the initial position p0, a length greater than or equal to the distance from the initial position p0 to the set position p in FIG. A supporter 40 having to be formed. This phenomenon is very disadvantageous not only in terms of consumption of the material 90 but also in terms of printing time.

According to the print bed of the present invention, the sub bed 130 at the initial position p0 moves to the set position p close to the sculpture 30, and the set position p with respect to the sculpture 30 (at a position relative to the sculpture 30) ) can be maintained in a fixed state. According to the present embodiment, the length of the supporter 40 formed on the sub-bed 130 may be shortened by the distance from the initial position p0 to the set position p.

In addition, in the case of the PBF method using the powder as the material 90, the amount of powder to be stacked from the initial position p0 to the set position p can be saved. This can have a positive effect on reducing the application time of the powder and reducing the unrecovered amount of the powder.

When the sub-bed 130 moves from the initial position p0 to the set position p, the printing unit 10 is a rod-shaped supporter extending from one side of the sub-bed 130 facing the sculpture 30 toward the sculpture 30 . (40) can be formed. The printing unit 10 may print the sculpture 30 on the supporter 40 having a shorter length than the length extending from the initial position p0 to the sculpture 30 . According to the present embodiment, the supporter 40 having a length shortened by the distance moved by the sub-bed 130 from the initial position p0 to the set position p may be generated by the printing unit 10 . The formation of the supporter 40 with a shorter length means that the dummy time required to print the supporter 40 is reduced, and at the same time, the amount of material 90 consumed for forming the supporter 40 is reduced. can

2 is a schematic diagram showing a print bed of a comparative example.

The comparative embodiment of FIG. 2 may include a single main bed 190 excluding the sub-bed 130 .

The main bed 190 may be formed in a flat plate shape with one surface facing the sculpture 30 in order to support the sculptures 30 of various shapes. The main bed 190 may be formed to be liftable toward the sculpture 30 .

A powder space having the main bed 190 as a floor and the base 110 as a side wall is formed, powder is stacked in the corresponding powder space, and the sculpture 30 can be printed. Whenever the layer of the sculpture 30 is printed, the main bed 190 descends, and the powder space may increase as much as the main bed 190 descends. The powder may be filled in the increased powder space using the roller 20 or the like, and the layer formed by the newly filled powder may be printed again by the printing unit 10 .

Even if the sculpture 30 of any shape is initially printed, the main bed 190 may correspond to a state in which the main bed 190 is always disposed at the initial position p0 compared to the sub-bed 130 . Accordingly, all of the lengths of the supporters 40 formed on the main bed 190 may have a length extending from the initial position p0 to the sculpture 30 .

When the length of the supporter 40 is increased, it takes a lot of time to form the supporter 40 , and a large amount of material 90 may be allocated to the supporter 40 . In addition, when the length of the supporter 40 is increased, it is structurally weak, and thus a larger number of the supporters 40 is required compared to when the length of the supporter 40 is short. After all, according to the comparative embodiment, compared to the print bed of the present invention, time and physical resources may be wasted enormously in the generation of the supporter 40 .

Returning to FIG. 1 again, each sub-bed 130 may move toward different parts of the lower part of the sculpture 30 so as not to overlap each other.

The setting positions p targeted by each sub-bed 130 may be formed independently of each other in a direction horizontal to the ground and a direction perpendicular to the ground.

The specific setting position may be determined according to the position of the bottom of the sculpture 30 facing the specific sub-bed. In other words, the specific setting position may be determined based on the coordinates of the part of the sculpture 30 to be supported by the specific sub-bed. The setting position may be selected within a set distance from the coordinates of a portion of the sculpture 30 within a range where the sub-bed 130 does not contact the sculpture 30 .

A control unit 170 for controlling the sub-bed 130 may be additionally provided in the print bed.

When the shape data of the sculpture 30 is input, the control unit 170 may set a setting position of each sub-bed 130 as a movement target according to the shape data, respectively.

The control unit 170 may move a specific sub-bed to a specific setting position in accordance with the printing process of the printing unit 10 .

Once the specific sub-bed moves to a specific setting position, the control unit 170 may lower the specific sub-bed by the unit height whenever the printing unit 10 completes the forming process of the sculpture 30 by the unit height. The unit height may be equal to the thickness or height of the layer. 3D printing may print the sculpture 30 in units of layers (layers) of a set thickness. Once a specific layer is formed, the printing unit 10 may rise by the height or thickness of the layer to print the next layer. Alternatively, the printing unit 10 may stay at the same height, and the pedestal supporting the sculpture 30 , for example, the sub-bed 130 may be lowered by the height or thickness of the layer.

For example, the printing unit 10 may print the sculpture 30 in a PBF (Powder Bed Fusion) method of irradiating a laser to the powder layer on which the powder is stacked. In this case, the sub-bed 130 may be disposed to face the printing unit 10 with the powder interposed therebetween. Whenever the printing unit 10 completes the laser irradiation process for the powder layer, the control unit 170 may lower the specific sub-bed by the thickness of the powder layer. The laser-irradiated powder layer may descend as much as the thickness of the powder layer together with a specific sub-bed.

3 is a schematic diagram showing the sub-bed 130 of the present invention.

When the area of the set shape in plan view is divided into a plurality of divided areas, the sub-bed 130 may be provided for each divided area.

The sub-bed 130 may have the same planar shape as the divided area. For example, the planar shape of the divided area in FIG. 3 may be a square, and accordingly, the planar shape of the sub-bed 130 may also be a square.

The arrangement position of the sub-bed 130 with respect to the sculpture 30 may be determined such that the plurality of sub-beds 130 in a plan view invade or span the projection range t of the sculpture 30 .

The plurality of sub-beds 130 formed to invade the projection range t of the sculpture 30 may move toward different set positions. The plurality of sub-beds 130 moving toward different setting positions may be arranged to face different parts of the sculpture 30 at their respective setting positions. In this case, the plurality of sub-beds 130 may move relative to each other or may move independently of each other.

A three-dimensional space formed by three axes x, y, and z orthogonal to each other may be defined. At this time, in FIG. 3 , the nine sub-beds 130 are arranged in three rows in the x-axis direction (horizontal direction), and are arranged in three rows in the y-axis direction (vertical direction). Four sub-beds 130 disposed on the upper left side on the xy plane may protrude corresponding to the grooves formed in the sculpture 30 . The z-axis may be parallel to the direction of gravity.

It is preferable that the maximum number of sub-beds 130 of the present invention be arranged so as to fall within the projection range t of the sculpture 30 .

The number of sub-beds 130 belonging to the projection range t may be similar to the number of pixels forming a screen of a set size and determining a resolution in a similar display. An increase in the number of sub-beds 130 belonging to the projection range t may mean that each sub-bed 130 has a geometric property that can approach the sculpture 30 more closely. Accordingly, the length of the supporter 40 may be shortened or the amount of powder consumed may be reduced.

4 is a schematic diagram illustrating the shift unit 160 .

In order to reduce the amount of powder used for molding the sculpture 30 in the PBF method, the shift unit 160 may be provided in the print bed.

The shift unit 160 may be formed to face the side of the sculpture 30 printed on the base unit 110 .

The shift unit 160 moves toward the side of the sculpture 30 , and may reduce the accommodation space in which the sculpture 30 is accommodated in accordance with the sculpture 30 in the lateral direction of the sculpture 30 .

For example, when accommodated in a chamber having a sidewall of the sculpture 30 or sinking in the space of the groove-shaped base portion 110, the shift unit 160 is disposed between the sidewall of the chamber and the sculpture 30, or It may be disposed between the sidewall of the base 110 and the sculpture 30 . The shift unit 160 may be inserted from the outside of the chamber or the base unit 110 or may protrude from the side wall of the chamber or the side wall of the base unit 110 toward the side of the sculpture 30 .

Between the chamber and the sculpture 30 or between the base part 110 and the sculpture 30 may correspond to a space originally filled with powder. When the shift is inserted into the corresponding space, the amount of powder by the volume of the shift unit 160 can be reduced.

As another example, the sub-bed 130 may replace the function of the shift unit 160 .

A specific sub-bed among the plurality of sub-beds 130 may be disposed at a position facing the side of the sculpture 30 .

Another sub-bed of the plurality of sub-beds 130 may be disposed at a position facing the lower surface of the sculpture 30 .

A specific sub-bed disposed to face the side of the sculpture 30 is lowered in accordance with the printing thickness of the printing unit 10 while the other sub-beds disposed to face the bottom of the sculpture 30 are printed in the process of being printed. ) can be maintained regardless of the

In (a) of FIG. 5 , some sub-beds 130 are disposed between the sculpture 30 and the sidewalls of the base part 110 . The sub-bed 130 disposed between the sculpture 30 and the sidewall of the base part 110 may reduce the amount of powder filled in the base part 110 similarly to the shift part 160 .

On the other hand, when the shape data of the sculpture 30 is input, the posture unit 150 for determining the posture of the sculpture 30 to be disposed on the base unit 110 may be provided in the print bed.

5 is a schematic diagram illustrating the operation of the posture unit 150 .

The posture unit 150 may calculate the total number of supporters 40 to be formed between the plurality of sub-beds 130 and the sculpture 30 .

The posture unit 150 may determine the posture of the sculpture 30 in which the total number of the supporters 40 is the minimum as the printing posture. The setting position p varies depending on the posture of the sculpture 30 , and the posture unit 150 may determine the setting position p according to the printing posture.

The supporter 40 may support the bottom surface of the sculpture 30 . Therefore, in order to reduce the number of supporters 40, it is preferable that the bottom surface area of the sculpture 30 is as small as possible.

For example, in FIG. 5 , shape data representing the skull-shaped sculpture 30 may be input to the posture unit 150 in order to print the skull implant corresponding to the sculpture 30 . The posture unit 150 may simulate the rotation of the sculpture 30 indicated by the shape data on the sub-bed 130 . The posture unit 150 may calculate the area of the bottom surface of the sculpture 30 whenever the sculpture 30 is rotated by a set angle. The posture unit 150 may determine the standing posture in which the bottom surface area is the minimum (a) and (c) of FIG. 5 as the printing posture.

The posture unit 150 may extract a position of each of the lower surfaces of the sculptures 30 facing each sub-bed 130 based on the printing posture. The posture unit 150 may determine a set position p within a range of a set distance from the extracted position.

On the other hand, in the PBF (Powder Bed Fusion) method of irradiating a laser to the powder layer on which the powder is stacked, the posture part 150 surrounds the outer surface of the sculpture 30 in a simulated state in which the sculpture 30 is completed. The total amount of powder can be calculated.

The posture unit 150 may determine the posture of the sculpture 30 in which the total amount of the calculated powder is the minimum as the candidate posture.

The setting position p varies depending on the posture of the sculpture 30 , and the posture unit 150 may determine the setting position according to the candidate posture.

The total amount of powder may vary depending on the sub-bed 130 disposed at the set position p. The posture unit 150 may correct the total amount of powder according to the sub-bed 130 disposed at the set position p.

The posture unit 150 may calculate the total amount of the corrected powder while changing the posture of the sculpture 30 in the virtual space.

The posture unit 150 may determine a posture with the smallest total amount of corrected powder among postures of the plurality of sculptures 30 as the final print posture.

Assuming a virtual cuboid circumscribed in the sculpture 30 , the cuboid may rotate together with the sculpture 30 . Therefore, when filling the cuboid with powder, the amount of powder may be the same regardless of the posture of the sculpture 30 . However, due to the sub-bed 130 of the present invention, one surface of the rectangular parallelepiped facing the floor is disposed inside the rectangular parallelepiped through the sub-bed 130, and the amount of powder filled in the rectangular parallelepiped can be reduced. The posture unit 150 may calculate the amount of powder filled in the virtual cuboid containing the sculpture 30 in consideration of the sub-bed 130 disposed at the set position p. The posture unit 150 may determine a posture (including an arrangement position, an angle with respect to the x-axis, an angle with respect to the y-axis, an angle with respect to the z-axis, etc.) in which the calculated amount of powder is the minimum as the print posture. The virtual cuboid is set to help understanding, and the shape of a space such as a chamber provided for molding the sculpture 30 may have various closed curved shapes.

When a plurality of sub-beds 130 that move independently of each other are provided, two issues may arise.

First, the sub-bed 130 that has moved to its respective set position p must maintain a stationary state in which movement is fixed with respect to other sub-beds in the vicinity in the subsequent printing process. When the processing process for one layer is completed by the printing unit 10, the plurality of sub-beds 130 may be lowered together by the thickness of the layer for lamination of the next layer (hereinafter, referred to as layer descending). . At this time, if the plurality of sub-beds 130 move relative to each other due to backlash and tolerance of the gears that independently move each sub-bed 130 , it may be difficult to perform a realistic printing operation.

For example, when a sub bed 130 is lowered by 0.21 mm and another sub bed is lowered by 0.20 mm when the layer is lowered, the sculpture 30 has a different shape from the initial design value due to a tolerance of 0.01 mm or an error such as a crack may occur. Therefore, when the layer is lowered, the plurality of sub-beds 130 supporting the sculpture 30 need to be lowered by the same distance.

Second, a gap between each sub-bed 130 generated due to an environment in which a plurality of sub-beds 130 is provided instead of a single main bed 190 must be sealed.

This is because the powder corresponding to the material 90 may leak through the gap between each sub-bed 130 . Alternatively, various gases forming the printing atmosphere may leak to the outside through the gap.

First, let's look at the countermeasures for layer descent.

When the printing unit 10 that forms the sculpture 30 while laminating the material 90 is provided, the main bed 190 moving with respect to the base unit 110 along the stacking direction of the material 90 is printed. It may be provided in addition to the bed.

In this case, the main bed 190 may be movably installed on the base part 110 . In addition, the sub-bed 130 may be movably installed on the main bed 190 .

The sub-bed 130 may reach the set position p while moving with respect to the main bed 190 .

The sub-bed 130 that has reached the set position may maintain a fixed state in which the movement is stopped with respect to the main bed 190 .

The main bed 190 may move by a unit height along a direction parallel to the stacking direction together with the sub-bed 130 that maintains a fixed state whenever the printing unit 10 stacks the material 90 by a unit height. .

According to the present embodiment, the plurality of sub-beds 130 provided on the main bed 190 can move together without error.

6 is a schematic diagram showing another print bed of the present invention.

One surface of the base part 110 facing the sculpture 30 or one surface of the main bed 190 may be divided into a plurality of divided regions. In this case, the sub-bed 130 may be provided for each divided area, and may be formed so as to be able to move up and down with respect to the base part 110 in the direction of gravity. In this case, the setting position p set for each sub-bed 130 may be formed on an imaginary straight line extending from the center of each sub-bed 130 in the direction of gravity.

For example, on one surface of the base part 110 facing the sculpture 30 , a main bed 190 formed to be liftable in the direction of gravity with respect to the base part 110 may be provided.

The sub-bed 130 may be installed through a hole formed on the main bed 190 .

The plurality of sub-beds 130 may be formed to be lifted independently of each other along the direction of gravity through the hole of the main bed 190 .

7 is a schematic diagram showing another print bed of the present invention.

The main bed 190 formed to be movable with respect to the base part 110 may be provided with a joint part 135 that rotates based on the main bed 190 . The joint part 135 may move the sub-bed 130 while rotating based on the main bed 190 . As an example, the joint part 135 may include a multi-joint parallel structure manipulator, a robot arm, etc. that are moved by pneumatic, hydraulic, motor, or the like.

The sub-bed 130 of FIG. 6 or the sub-bed 130 of FIG. 7 may move toward the set position p with the main bed 190 disposed at a specific position. The sub-bed 130 that has reached the set position p may stop with respect to the main bed 190 . In a state in which the plurality of sub-beds 130 are all stopped, the main bed 190 may move by the stacking height in the stacking direction of the material 90 forming the sculpture 30 or in the opposite direction.

An actuator 139 for moving the sub-bed 130 with respect to the base 110 may be provided in the print bed or sub-bed 130 . The actuator 139 may include at least one of a pneumatic cylinder 133 , a hydraulic cylinder 133 , a motor, a hydraulic pump, and a pneumatic pump.

8 is a schematic diagram showing an actuator 139 of the first embodiment.

The actuator 139 may be provided for each sub-bed 130 . If the main board is additionally provided, an actuator 139 for the main board may be added.

The actuator 139 of FIG. 8 may include a motor provided for each sub-bed 130 . A screw 138 in which a screw 138 extends along a moving direction of the sub bed 130 and a male screw 138 is formed may be connected to the shaft of the motor.

The sub-bed 130 may be formed in a cylindrical shape into which the screw 138 is inserted. In this case, a female screw 136 engaged with the male screw of the screw 138 may be formed at one end of the sub bed 130 facing the screw 138 . The sub-bed 130 may be formed to have a limited degree of rotational freedom about the screw 138 as an axis. According to the configuration, when the screw 138 rotates due to the rotation of the motor, the sub-bed 130 may move along the extension direction of the screw 138 . The sub-bed 130 may move in a forward direction closer to the sculpture 30 or in a reverse direction away from the sculpture 30 according to the rotation direction of the motor or screw 138 .

Position control targeting a plurality of sub-beds 130 may be performed using a single actuator 139 . As an example, a link unit that transmits the power of the actuator 139 to the sub-bed 130 together with the actuator 139 that provides power to move the sub-bed 130, for example, hydraulic pressure, pneumatic pressure, rotational force, etc. may be provided. have. The link unit may include various gears, a pipe through which a fluid flows, a valve for controlling the flow of the fluid, and the like. A clutch 143 for connecting the link unit to the sub-bed 130 or disconnecting the link unit from the sub-bed 130, and a control unit 170 for controlling the clutch 143 may be provided.

The control unit 170 may transmit the power of the single actuator 139 to the plurality of sub-beds 130 by a set amount using the link unit and the clutch 143 . At this time, the set amount may include power required for the sub-bed 130 to reach its respective set position p.

9 is a schematic diagram showing an actuator 139 of the second embodiment.

A single hydraulic pump may be commonly connected to the plurality of cylinders 133 to which the plurality of sub-beds 130 are connected. A flow path connected to the hydraulic pump may be branched toward the plurality of cylinders 133 . In this case, a valve controlled by the control unit 170 and a sensing unit for sensing an end position of the sub-bed 130 may be provided in the flow path branched to each cylinder 133 . In this specification, the valve may correspond to a kind of clutch 143 .

Due to the fluid provided from the pump corresponding to the actuator 139 that moves the sub-bed 130 , the plurality of sub-beds 130 may move toward the sculpture 30 . The end position of the sub-bed 130 moving toward the sculpture 30 may be monitored in real time by a sensing unit. When the sensing unit detects that the end position of the specific sub-bed has reached its set position p, the control unit 170 may close the valve connected to the specific sub-bed. The specific subbed, which is no longer supplied with fluid due to the closing of the valve, may stop at the set position p. On the other hand, regardless of the stop of the specific sub-bed, other sub-beds that have not reached their set position p can continuously approach the sculpture 30 due to the fluid flowing in through the open valve.

10 is a schematic diagram showing an actuator 139 of the third embodiment.

The first gear 141 connected to the motor shaft may be formed according to the number of sub-beds 130 having the screw 138 .

The first gear 141 disposed to face each sub bed 130 may be disposed at a position spaced apart from the sub bed 130 .

The clutch 143 may include a connecting gear connecting the first gear 141 and the screw 138 .

The clutch 143 may be fitted in an empty space between the first gear 141 and the screw 138 or formed to be detachable from the empty space. In this case, the first operation mode in which the clutch 143 is fitted into the empty space and the second operation mode in which the clutch 143 is separated from the empty space may be determined by the controller 170 . A sensing unit for sensing whether the sub-bed 130 has reached the set position p may be provided. The sensing result of the sensing unit may be transmitted to the control unit 170 .

If it is determined that the sub-bed 130 has not reached the set position p as a result of the sensing, the controller 170 may insert the clutch 143 into the empty space between the first gear 141 and the screw 138 . As a result of the sensing, when it is determined that the sub-bed 130 has reached the set position p, the control unit 170 may take out the clutch 143 sandwiched between the first gear 141 and the screw 138 .

The controller 170 for controlling the movement of the sub-bed 130 may feedback-control the actuator 139 so that the end position of the sub-bed 130 sensed by the sensing unit follows the set position p.

Meanwhile, a gravity compensating part for physically compensating for the self-weight of the sub-bed 130 and a partial load of the sculpture 30 may be additionally provided. The gravity compensating part may provide a force to lift the sub-bed 130 in a direction opposite to gravity. The gravity compensating part may include a weight, an elastic means, etc. that lift or push up the sub bed 130 in a direction opposite to the direction of gravity. According to the gravity compensating part, the load required to move the actuator 139 can be reduced.

A countermeasure for the gap formed between each sub-bed 130 will be described.

11 is a schematic view showing a gas atmosphere inside the chamber in which the sculpture 30 is 3D printed. 12 is a schematic view showing the first sealing portion 117 according to an embodiment. 13 is a schematic view showing a second sealing portion 118 of another embodiment.

A first sealing part 117, a sub-bed ( At least one of the second sealing part 118 closing the second gap between the 130 and the chamber and the third sealing part 119 closing the third gap formed between the base part 110 and the external pipe is printed. It may be provided on the bed.

The base 110 may form a part of the chamber.

If there is no first sealing part 117 and the third sealing part 119 is provided, gas may be filled up to the base of the base part 110 as in the first atmosphere a of FIG. 11 . In this case, the gas consumption may increase or the unrecovered amount of the powder may be increased.

When the first sealing part 117 and the second sealing part 118 are provided, only the space limited to the upper part of the sub-bed 130 may be filled with gas as in the second atmosphere b of FIG. 11 . In this case, the gas consumption can be reduced and the unrecovered amount of the powder can be reduced.

The first sealing part 117 closing the first gap may be formed in a hollow pipe shape covering the side surface of the sub-bed 130 . In this case, the cross-section of the first sealing part 117 may be the same as a plate shape covering one side of the sub-bed 130 as shown in FIG. 12 .

As another example, the first sealing part 117 for closing the first gap may include an O-ring installed on the side surface of the sub-bed 130 as shown in FIG. 13 .

The second sealing part 118 for closing the second gap may include the base part 110 facing the sub-bed 130 or a large O-ring installed along the inner wall of the chamber.

The third sealing part 119 for closing the third gap may include a gasket for blocking between the gas inlet and the pipe part formed in the chamber or the base part 110 .

As described above, the print bed may include a molding plate disposed to face the three-dimensionally printed object 30 . A plurality of sub-beds 130 that individually move up and down may be provided on one surface of the molding plate facing the sculpture 30 . The sub-bed 130 may protrude or sink with respect to the sculpture 30 through vertical movement. A molding plate having a shape coupled to one surface of the sculpture 30 may be formed by protrusion or depression of each sub-bed 130 .

When the main bed 190 disposed to face the three-dimensionally printed object 30 is additionally provided, the plurality of sub-beds 130 may be movably formed on the main bed 190 . The sub-bed 130 may move toward the sculpture 30 through the first energy transferred using the main bed 190 as a support point. The main bed 190 is transmitted using the base portion 110 supported on the ground as a supporting point, and can move in the direction toward the sculpture 30 or in the opposite direction by using the second energy that is differentiated from the first energy. When the first energy and the second energy that are separate from each other are used, after the plurality of sub-beds 130 reach their respective set positions, the entire plurality of sub-beds 130 may be accurately layered without error.

14 is a flowchart illustrating an automatic control method of a print bed.

The control method shown in FIG. 14 may be performed by the print bed of FIG. 1 .

The method of controlling the print bed may include an acquiring step (S 510), a determining step (S 520), a moving step (S 530), and a descending step (S 540).

The acquiring step ( S510 ) may include acquiring the shape data of the sculpture 30 . For example, the posture unit 150 or the control unit 170 may obtain three-dimensional shape data of the sculpture 30 having an STL file format.

The determining step (S520) determines the posture of the sculpture 30 based on at least one of the number of supporters 40 supporting the sculpture 30 or the consumption amount of powder corresponding to the material 90 of the sculpture 30 may include the step of The determining step ( S520 ) may be performed by the posture unit 150 . Also, the posture unit 150 may determine a path including driving the model plate (generating a path function such as Gcode). In this case, in the path determination process, a setting position may be determined, and a path of the sub-bed 130 reaching the setting position may be determined.

The moving step ( S530 ) may include moving the plurality of sub-beds 130 to a set position close to the sculpture 30 by a set distance according to the posture of the sculpture 30 . The moving step ( S530 ) may be performed by the controller 170 and the actuator 139 .

The lowering step ( S540 ) may include lowering the sub-bed 130 that has moved to the set position by the thickness of one layer whenever one layer of the sculpture 30 is printed. The descending step ( S540 ) may be performed by the controller 170 and the actuator 139 . When the main bed 190 is added, the control unit 170 and the actuator 139 may elevate only the main bed 190 while stopping the movement of the sub-bed 130 moving on the main bed 190 .

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present invention as defined in the following claims are also present. It belongs to the scope of the invention.

10...Printing unit 11...Laser generator
13...Regulator 20...Roller
30...Sculpture 40...Supporter
41...filament 43...body
50...powder bed 70...supply means
80...Means of recovery 90...Materials
110...Base part 117...First sealing part
118...Second sealing part 119...Third sealing part
130...Subbed 131...Post
132...piston rod 133...cylinder
134...piston 135...joint
136...Female thread 138...Screw
139...actuator 141...first gear
143...Clutch 150...More
160...shift unit 170...control unit
190...Main bed

Claims (23)

a base portion formed to face the three-dimensionally printed object;
Includes; a plurality of sub-beds formed to be movable with respect to the base portion;
The sub-bed moves to a set position corresponding to a position close to the sculpture to be printed on the base by a set distance,
Each sub-bed moves toward a different part of the bottom of the sculpture,
The setting positions targeted by each sub-bed are formed independently of each other in a direction horizontal to the ground and a direction perpendicular to the ground,
The specific setting position of the print bed is determined according to the position of the bottom of the sculpture facing the specific sub bed.
According to claim 1,
A printing unit for printing the sculpture is provided,
The printing unit prints the sculpture on the sub-bed in a state in which the sub-bed, which has moved to the set position, is stopped at the set position.
According to claim 1,
A printing unit for printing the sculpture is provided,
When the sub-bed moves from the initial position to the set position, the printing unit forms a rod-shaped supporter extending toward the sculpture from one side of the sub-bed facing the sculpture,
The printing unit prints the sculpture on the supporter having a shorter length than the length extending from the initial position to the sculpture.
delete a base portion formed to face the three-dimensionally printed object;
Includes; a plurality of sub-beds formed to be movable with respect to the base portion;
The sub-bed moves to a set position corresponding to a position close to the sculpture to be printed on the base by a set distance,
A printing unit for printing the sculpture and a control unit for controlling the sub-bed are provided,
When the shape data of the sculpture is input, the control unit sets each of the setting positions as a movement target of each sub bed according to the shape data,
The control unit moves a specific sub-bed to a specific setting position in accordance with the printing process of the printing unit,
Once the specific sub-bed moves to the specific setting position, the control unit lowers the specific sub-bed by the unit height whenever the printing unit completes the forming process of the sculpture by the unit height.
According to claim 1,
A printing unit for printing the sculpture in a PBF (Powder Bed Fusion) method of irradiating a laser to the powder layer on which the powder is laminated, and a control unit for controlling the sub-bed are provided,
The sub-bed is disposed to face the printing unit with the powder interposed therebetween,
The control unit lowers a specific sub-bed by the thickness of the powder layer whenever the printing unit completes the laser irradiation process for the powder layer,
A print bed in which the laser-irradiated powder layer descends by the thickness of the powder layer together with the specific sub-bed.
a base portion formed to face the three-dimensionally printed object;
Includes; a plurality of sub-beds formed to be movable with respect to the base portion;
The sub-bed moves to a set position corresponding to a position close to the sculpture to be printed on the base by a set distance,
When the area of the set shape is divided into a plurality of division areas on a planar view,
The sub-bed is provided for each divided area,
The sub-bed has the same planar shape as the divided area,
The arrangement position of the sub-beds with respect to the sculpture is determined so that the plurality of sub-beds in a plan view invade or span the projection range of the sculpture,
A plurality of the sub-beds formed to encroach on the projection range of the sculpture move toward different setting positions, and are arranged to face different parts of the sculpture at their respective setting positions.
a base portion formed to face the three-dimensionally printed object;
Includes; a plurality of sub-beds formed to be movable with respect to the base portion;
The sub-bed moves to a set position corresponding to a position close to the sculpture to be printed on the base by a set distance,
When the shape data of the sculpture is input, a posture unit for determining the posture of the sculpture to be disposed on the base is provided,
The posture part calculates the total number of supporters to be formed between the plurality of sub-beds and the sculpture,
The posture unit determines the posture of the sculpture in which the total number of the supporters is the minimum as the printing posture,
The setting position varies depending on the posture of the sculpture, and the posture unit determines the setting position according to the printing posture of the print bed.
a base portion formed to face the three-dimensionally printed object;
Includes; a plurality of sub-beds formed to be movable with respect to the base portion;
The sub-bed moves to a set position corresponding to a position close to the sculpture to be printed on the base by a set distance,
When the shape data of the sculpture is input, a posture unit for determining the posture of the sculpture to be disposed on the base is provided,
In the PBF (Powder Bed Fusion) method of irradiating a laser to the powder layer on which the powder is laminated, the posture part calculates the total amount of the powder surrounding the outer surface of the sculpture in a state where the sculpture is simulated,
The posture unit determines the posture of the sculpture in which the total amount of the powder is the minimum as a candidate posture,
The setting position varies according to the posture of the sculpture, and the posture unit determines the setting position according to the candidate posture.
10. The method of claim 9,
The total amount of powder varies depending on the sub-bed disposed at the set position, and the posture unit corrects the total amount of powder according to the sub-bed disposed at the set position,
The posture unit calculates the total amount of powder corrected while changing the posture of the sculpture in the virtual space,
The posture unit determines the final print posture as the posture with the smallest amount of the corrected powder among the postures of the plurality of sculptures.
According to claim 1,
A shift part formed to face the side of the sculpture printed on the base part is provided,
The shift unit moves toward the side of the sculpture, and the print bed reduces the receiving space in which the sculpture is accommodated in accordance with the sculpture in the lateral direction of the sculpture.
a base portion formed to face the three-dimensionally printed object;
Includes; a plurality of sub-beds formed to be movable with respect to the base portion;
The sub-bed moves to a set position corresponding to a position close to the sculpture to be printed on the base by a set distance,
A specific sub-bed among the plurality of sub-beds is disposed at a position facing the side of the sculpture,
Another sub-bed among the plurality of sub-beds is disposed at a position facing the bottom of the sculpture,
The specific sub-bed disposed to face the side of the sculpture maintains a stationary state regardless of the descent of the other sub-beds disposed facing the bottom of the sculpture in the process of printing the sculpture.
a base portion formed to face the three-dimensionally printed object;
Includes; a plurality of sub-beds formed to be movable with respect to the base portion;
The sub-bed moves to a set position corresponding to a position close to the sculpture to be printed on the base by a set distance,
A printing unit for forming the sculpture is provided while laminating the material,
A main bed moving with respect to the base portion is provided along the stacking direction of the material,
The sub-bed is movably installed on the main bed,
The sub-bed reaches the set position while moving relative to the main bed,
The sub-bed that has reached the set position maintains a fixed state in which movement is stopped with respect to the main bed,
The main bed is a print bed that moves by the unit height in a direction parallel to the stacking direction together with the sub-bed maintaining the fixed state whenever the printing unit stacks the material by the unit height.
a base portion formed to face the three-dimensionally printed object;
Includes; a plurality of sub-beds formed to be movable with respect to the base portion;
The sub-bed moves to a set position corresponding to a position close to the sculpture to be printed on the base by a set distance,
One side of the base part or one side of the main bed facing the sculpture is divided into a plurality of divided areas,
The sub-bed is provided for each of the divided areas, and the print bed is formed to be movable up and down in a direction of gravity with respect to the base part.
a base portion formed to face the three-dimensionally printed object;
Includes; a plurality of sub-beds formed to be movable with respect to the base portion;
The sub-bed moves to a set position corresponding to a position close to the sculpture to be printed on the base by a set distance,
On one surface of the base part facing the sculpture, a main bed formed so as to be liftable along the direction of gravity with respect to the base part is provided,
The sub-bed is installed through a through hole formed on the main bed,
A plurality of the sub-beds are formed to be lifted independently of each other in the direction of gravity through the through-holes.
a base portion formed to face the three-dimensionally printed object;
Includes; a plurality of sub-beds formed to be movable with respect to the base portion;
The sub-bed moves to a set position corresponding to a position close to the sculpture to be printed on the base by a set distance,
On one surface of the base part facing the sculpture, a main bed formed so as to be liftable along the direction of gravity with respect to the base part is provided,
A print bed provided with an articulating part for moving the sub-bed while rotating with respect to the main bed.
According to claim 1,
An actuator for moving the sub-bed with respect to the base is provided,
The actuator is a print bed including at least one of a pneumatic cylinder, a hydraulic cylinder, and a motor.
a base portion formed to face the three-dimensionally printed object;
Includes; a plurality of sub-beds formed to be movable with respect to the base portion;
The sub-bed moves to a set position corresponding to a position close to the sculpture to be printed on the base by a set distance,
An actuator for providing power to move the sub-bed, a link part for transmitting the power of the actuator to the sub-bed, a clutch for connecting or disconnecting the link part to the sub-bed, and a controller for controlling the clutch are provided become,
The control unit transmits the power of the single actuator to the plurality of sub-beds by a set amount using the link unit and the clutch,
The set amount includes a power required for the plurality of sub-beds to reach their respective set positions.
a base portion formed to face the three-dimensionally printed object;
Includes; a plurality of sub-beds formed to be movable with respect to the base portion;
The sub-bed moves to a set position corresponding to a position close to the sculpture to be printed on the base by a set distance,
An actuator for moving the sub-bed, a sensing unit for sensing an end position of the sub-bed, and a control unit for controlling movement of the sub-bed are provided;
The control unit feedback-controls the actuator so that the end position sensed by the sensing unit follows the set position.
a base portion formed to face the three-dimensionally printed object;
Includes; a plurality of sub-beds formed to be movable with respect to the base portion;
The sub-bed moves to a set position corresponding to a position close to the sculpture to be printed on the base by a set distance,
A first sealing part for closing the first gap between the plurality of sub-beds with respect to the gas filling the chamber in which the base part is installed or the material of the sculpture, a second sealing part for closing the second gap between the sub-bed and the chamber A print bed provided with at least one of a sealing unit and a third sealing unit closing a third gap formed between the chamber and an external pipe.
Including; a molding plate disposed to face the three-dimensionally printed object;
A plurality of sub-beds that individually move up and down are provided on one surface of the molding plate facing the sculpture,
The sub-bed protrudes or sinks with respect to the sculpture through the up-and-down movement,
The molding plate having a shape coupled to one surface of the sculpture is formed by protrusion or depression of each sub-bed,
Each sub-bed moves toward a different part of the bottom of the sculpture,
The setting positions targeted by each sub-bed are formed independently of each other in a direction horizontal to the ground and a direction perpendicular to the ground,
The specific setting position of the print bed is determined according to the position of the bottom of the sculpture facing the specific sub bed.
a main bed disposed to face the three-dimensionally printed sculpture;
Including; a plurality of sub-beds movably formed on the main bed;
The sub-bed moves toward the sculpture through the first energy transferred using the main bed as a support point,
The main bed is transferred using the base part supported on the ground as a supporting point and moves in the direction toward the sculpture or in the opposite direction by using the second energy that is differentiated from the first energy,
Each sub-bed moves toward a different part of the bottom of the sculpture,
The setting positions targeted by each sub-bed are formed independently of each other in a direction horizontal to the ground and a direction perpendicular to the ground,
The specific setting position of the print bed is determined according to the position of the bottom of the sculpture facing the specific sub bed.
In the automatic control method of the print bed,
acquiring shape data of the sculpture;
determining the posture of the sculpture based on at least one of the number of supporters supporting the sculpture or the consumption of powder corresponding to the material of the sculpture;
moving a plurality of sub-beds to a set position close to the sculpture by a set distance according to the posture of the sculpture;
Each time one layer of the sculpture is printed, lowering the sub-bed, which has moved to the set position, by the thickness of the one layer;
A control method comprising a.

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