KR102202664B1 - 3D printer with hardening prevention unit - Google Patents

Abstract

The 3D printer having a curing prevention unit according to the present invention comprises a case having an exterior and a chamber selectively sealed inside, a powder storage space for storing thermoplastic powder inside the case, and the powder storage space A molding space communicating and forming a three-dimensional molded product, a powder supply unit transferring the powder from the powder storage space to the molding space, a plurality of heaters heating the interior of the chamber, and the bottom of the chamber below the melting point of the thermoplastic powder It characterized in that it is configured to include a curing prevention unit for cooling to maintain the temperature of.

Description

3D printer with hardening prevention unit}

The present invention relates to a 3D printer having a curing prevention unit, and a curing prevention unit that prevents the dissolution of PEEK (Polyetheretherketone) powder between the powder storage space and the molding space so that the powder can be evenly stacked. It relates to a 3D printer equipped with.

The present invention relates to a 3D printer having a curing prevention unit capable of preventing in advance damage to a powder supply unit that may occur due to sticking of powder.

The present invention relates to a 3D printer having a curing prevention unit that provides heat to a 3D molded article by providing heat to a 3D molded article with an auxiliary heater to prevent rapid shrinkage, thereby enabling the formation of a 3D molded article with high dimensional accuracy.

The present invention relates to a 3D printer having a curing prevention unit provided with a heat insulating member between the powder storage space and the molding space so that the PEEK powder and the three-dimensional molded product can be stored or molded in an optimal state.

The present invention is provided with an atmosphere forming unit for supplying an inert gas for fire and explosion prevention in a heated state inside the molding space, and a 3D curing prevention unit equipped with a curing prevention unit to block sudden temperature changes inside the molding space in advance. It's about the printer.

The present invention relates to a 3D printer having a curing prevention unit provided with an oxygen concentration maintaining unit to maintain the oxygen concentration in a molding space above a certain level, thereby improving the appearance quality of a 3D molded article.

Conventionally, traditional processing methods such as casting or forging have been used to manufacture three-dimensional molded products. In addition, when using such a manufacturing method, in order to maintain the quality of the product, an operator with specialized knowledge had to perform it.

Recently, a 3D printer has been used as a device for processing a 3D molded product, and because of the advantage that even non-professionals can easily produce a 3D molded product, it has gradually replaced the traditional processing method.

In other words, 3D printers are equipment that produce real three-dimensional shapes as they are based on input two-dimensional drawings as if printing letters or pictures, and 3D printing technology is expanding to the fields of automobiles, medical care, arts, and education. It is widely used for making.

The principle of 3D printer can be divided into cutting type and stacking type, and most of 3D printers that are actually applied are stacked type without material loss.

The laminated 3D printer is a method of laminating through a method of projecting and curing a laser so that printed materials are completed.For example, Korean Patent No. 10-1801964 discloses a 3D multilayer printer using synthetic resin and ceramic powder as shown in FIG. Has been.

However, the preceding data is a material for making printed matter, and since a composition in a slurry state including ceramic powder, thermosetting resin, silane compound, and solvent is applied, shrinkage occurs during drying, which is insufficient to satisfy high dimensional accuracy.

Accordingly, Korean Patent Registration No. 10-1715124 discloses a powder application device used in a 3D printer for molding metal powder and a 3D printer having the same as shown in FIG. 2.

In addition, Korean Patent Publication No. 10-2017-0045331 discloses a three-dimensional object generating apparatus capable of generating a three-dimensional object while distributing the build material 104 to the build material distributor 106 as shown in FIG. 3.

In addition, Korean Patent Application Laid-Open No. 10-2018-0021221 discloses that the feed material 130 is spread by the spreader 140 as shown in FIG. 4 to form a layer, and the feed material 130 is cured by the beam 175. , An additive manufacturing system is disclosed that has a coolant dispenser 145 to allow rapid cooling of the feed material by traversing the platen 105.

However, the prior art has the following problems.

That is, the above technology has a problem in that the powder material remaining without being molded into a three-dimensional molded product is melted by the heat of the floor and interferes with the transport path of the component device that transports the powder material, causing damage.

In addition, the molten powder material is not preferable because it maintains a pressed state and makes the operation impossible.

In addition, there is a problem in that the dimensional accuracy of the molded three-dimensional molded article is lowered because it causes a rapid temperature change inside the molding space.

An object of the present invention is to solve the problems of the prior art as described above, by providing a curing prevention unit that prevents the dissolution of PEEK (Polyetheretherketone) powder between the powder storage space and the molding space so that the powder can be evenly stacked. It is to provide a 3D printer with a curing prevention unit.

Another object of the present invention is to provide a 3D printer having a curing prevention unit capable of preventing in advance damage to the powder supply unit that may occur due to sticking of the powder.

Another object of the present invention is to provide a 3D printer equipped with a curing prevention unit capable of forming a 3D molded product having a high dimensional accuracy by preventing rapid shrinkage by providing heat to a 3D molded product with an auxiliary heater. It is in doing.

Another object of the present invention is to provide a 3D printer with a curing prevention unit that has a heat insulating member between the powder storage space and the molding space so that PEEK powder and the three-dimensional molded product can be stored or molded in an optimal state. There is one.

Another object of the present invention is to prevent hardening by providing an atmosphere forming unit for supplying an inert gas to prevent fire and explosion inside the molding space in a heated state to prevent rapid temperature changes inside the molding space. It is to provide a 3D printer with a unit.

Another object of the present invention is to provide a 3D printer with a curing prevention unit that is equipped with an oxygen concentration maintenance unit to maintain the oxygen concentration in the molding space above a certain level, thereby improving the appearance quality of a 3D molded article. It is in doing.

A 3d printer with a curing prevention unit according to the present invention for achieving the above object includes a case having a chamber that forms an exterior and is selectively sealed inside, and a powder storage space for storing thermoplastic powder inside the case. And, a molding space communicating with the powder storage space to form a three-dimensional molded product, a powder supply unit transferring the powder from the powder storage space to the molding space, a plurality of heaters heating the interior of the chamber, and It characterized in that it comprises a curing prevention unit for cooling the bottom portion to maintain a temperature below the melting point of the thermoplastic powder.

The curing prevention unit includes: a fluid guide pipe for guiding a fluid into the interior of the bottom of the chamber, a fluid forcing device for forcing fluid movement to the fluid guide pipe, and a heat insulation for partitioning a cooling portion at the bottom of the chamber. It characterized in that it is configured to include a member.

The fluid guide pipe is characterized in that it is built into the bottom portion excluding the powder storage space and the molding space.

An auxiliary heater is provided outside the molding space to heat the three-dimensional molded article by generating heat with lower heat than the heater.

According to the present invention, a curing prevention unit that prevents the dissolution of PEEK (Polyetheretherketone) powder is provided between the powder storage space and the molding space, so that the powder can be evenly stacked, and by providing heat to the three-dimensional molded product by providing an auxiliary heater. Since rapid shrinkage can be prevented, it is possible to mold a three-dimensional molded product with high dimensional accuracy.

In addition, since it is possible to prevent damage to the powder supply unit that may occur due to sticking of the powder, maintenance and management are easy.

In addition, an insulating member is provided between the powder storage space and the molding space so that the PEEK powder and the three-dimensional molded product can be stored or molded in an optimal state.

In addition, by providing an atmosphere forming unit for supplying an inert gas for preventing fire and explosion inside the molding space in a heated state, it has the effect of blocking sudden temperature changes inside the molding space in advance.

In addition, it is expected to have an oxygen concentration maintenance unit to maintain the oxygen concentration in the molding space above a certain level, thereby improving the appearance quality of the three-dimensional molded article.

1 is a perspective view showing the appearance of a 3D lamination printer disclosed in Korean Patent Registration No. 10-1801964.
FIG. 2 is a perspective view showing the configuration of a powder application device and a 3D printer having the same for a 3D printer disclosed in Korean Patent Registration No. 10-1715124. FIG.
3 is a schematic diagram showing the configuration of a three-dimensional object generating apparatus disclosed in Korean Patent Application Publication No. 10-2017-0045331.
4 is a schematic diagram showing the configuration of an additive manufacturing system disclosed in Korean Patent Application Publication No. 10-2018-0021221.
Figure 5 is a perspective view showing the external configuration of a 3D printer with a curing prevention unit according to the present invention.
Figure 6 is a front view showing the internal configuration of the 3D printer with a curing prevention unit according to the present invention.
7 is a longitudinal sectional view showing the internal configuration of a 3D printer with a curing prevention unit according to the present invention.
Figure 8 is an enlarged cross-sectional view of the "A" part of Figure 7 showing the detailed structure of the molding space in the 3D printer equipped with a curing prevention unit according to the present invention.

Hereinafter, a configuration of a 3D printer (hereinafter referred to as “3D printer 100”) having a curing prevention unit 160 according to the present invention will be described with reference to FIGS. 5 and 6.

5 is a perspective view showing the external configuration of a 3D printer 100 having a curing prevention unit 160 according to the present invention, and FIG. 6 is a 3D printer having a curing prevention unit 160 according to the present invention A front view showing the internal configuration of 100 is shown.

Prior to this, terms or words used in the present specification and claims are not to be interpreted in a conventional and dictionary meaning, and the inventor can appropriately define the concept of terms in order to describe his own invention in the best way. It should be interpreted as a meaning and concept consistent with the technical idea of the present invention based on the principle that there is.

Therefore, the embodiments described in the present specification and the configurations shown in the drawings are only preferred embodiments of the present invention, and do not represent all the technical ideas of the present invention, and thus various equivalents that can replace them at the time of application It should be understood that there may be water and variations.

As shown in the drawing, the 3D printer 100 according to the present invention has an exterior formed by the case 110, a 3D molded product P is molded inside the left part, and the right part is a control for controlling the operation of the 3D printer 100 Unit 120 is placed.

The control unit 120 is configured to control the supply amount, temperature, oxygen concentration, laser operation, etc. of the thermoplastic powder inside the 3D printer 100, and includes a plurality of buttons.

A chamber 130 is positioned above the case 110. The chamber 130 is configured so that the front can be selectively opened when the door 112 is opened, and when the door 112 is shielded, the chamber 130 may include a sealer so that the inside of the chamber 130 is completely sealed. I can.

In addition, the chamber 130 is a place where the thermoplastic powder is stored and the three-dimensional molded product P is formed by irradiation with a laser beam.

That is, the left side of the chamber 130 is provided with a powder storage space 140 in which the thermoplastic powder is stored, and the right side of the chamber 130 is provided with a laser irradiator 152 and an output plate 154 to be stacked by a predetermined thickness. The molding space 150 is provided so that the three-dimensional molded product P can be molded while increasing in the height direction by irradiating the beam onto the thermoplastic powder.

Each cylinder 156 is provided at the lower side of the powder storage space 140 and the molding space 150 so that the upper part is raised and lowered while the lower part is fixed, so that the thermoplastic powder and the three-dimensional molded product P can be elevated. Is composed.

On the right side of the control unit 120, a curing prevention unit 160, which is an essential component of the present invention, is provided. The curing prevention unit 160 is configured to lower the temperature of the bottom surface located between the powder storage space 140 and the molding space 150 among the bottom surfaces of the chamber 130 so that the thermoplastic resin does not dissolve.

That is, the interior of the chamber 130 is heated to a temperature close to the melting temperature of the thermoplastic powder in order to prevent rapid cooling after forming the 3D molded article P.

At this time, the plate material forming the wall surface inside the chamber 130, especially the bottom, is gradually heated as a path through which the thermoplastic powder is transferred, so that the temperature may be higher than the melting temperature of the thermoplastic powder. At this time, the molding space 150 inside the powder storage space 140 The thermoplastic powder transferred to the machine is pressed together, making it impossible to form smoothly, and it may collide with other parts and cause damage.

Accordingly, the curing prevention unit 160 cools the bottom surface of the chamber 130 to maintain a temperature below the melting point of the thermoplastic powder, thereby preventing the thermoplastic powder from sticking together.

An atmosphere forming unit 170 is provided below the curing prevention unit 160. The atmosphere forming unit 170 is configured to prevent rapid cooling of the 3D molded article P by supplying heated inert gas into the chamber 130.

That is, the three-dimensional molded article P, which is stacked in the molding space 150 and molded in three dimensions, is heated around so as not to undergo a rapid temperature change, and nitrogen or argon gas to create an inert gas atmosphere inside the chamber 130 Injecting the 3D molded product P is rapidly cooled, resulting in uneven dimensional accuracy and poor appearance.

Accordingly, the atmosphere forming unit 170 is configured to supply an inert gas into the chamber 130 in a heated state by heating.

In addition, the atmosphere forming unit 170 is configured to interlock with an oxygen concentration maintaining unit (not shown). The oxygen concentration maintenance unit may be an oxygen sensor installed inside the chamber 130, and continuously measures the oxygen concentration inside the chamber 130, and an atmosphere forming unit (e.g., 0.5%) or less 170).

More specifically, when the oxygen concentration in the chamber 130 exceeds 0.5%, the oxygen concentration maintaining unit detects this and operates the atmosphere forming unit 170 to inject an inert gas into the chamber 130. It works to lower the oxygen concentration.

The oxygen concentration maintenance unit is to prevent the formation of a 3D molded product (P) in different colors depending on the oxygen concentration when manufacturing a 3D molded product (P) by applying a thermoplastic powder made of PEEK material, and to obtain a 3D molded product (P) of a uniform color. to be.

Hereinafter, a detailed configuration of the 3D printer 100 will be described with reference to FIGS. 7 and 8.

7 is a longitudinal sectional view showing the internal configuration of a 3D printer 100 having a curing prevention unit 160 according to the present invention, and FIG. 8 is a 3D having a curing prevention unit 160 according to the present invention. An enlarged cross-sectional view of part "A" of FIG. 7 showing the detailed structure of the molding space 150 in the printer 100 is shown.

As shown in the figure, a number of components are built into the chamber 130. A powder storage space 140 in which a thermoplastic powder is stored is provided on the left side of the chamber 130, and a molding space 150 in which a three-dimensional molded product P is molded is located on the right side.

The powder storage space 140 is adjusted in size by the lifting of the support plate 158 interlocking with the cylinder 156, and the molding space 150 is adapted to the lifting of the output plate 154 interlocking with the cylinder 156. Size is adjusted by

Further, a powder supply unit 134 is provided at the bottom of the chamber 130, that is, at the upper end of the powder storage space 140 and the molding space 150. The powder supply unit 134 is configured to include a blade to conveniently supply the thermoplastic powder, and the support plate 158 rises upward and moves to the right while the thermoplastic powder is raised by a certain height from the bottom. Thus, it serves to conveniently supply the thermoplastic powder to the upper side of the molding space 150.

A powder collecting unit 180 is provided on the right side of the molding space 150. The powder collection unit 180 has a space therein, and is supplied to the upper side of the molding space 150 among the thermoplastic powders transferred by the powder supply unit 134 and stores the remaining excess powder therein.

A plurality of heaters 132 are provided on the central side of the chamber 130. The heater 132 is a configuration for raising the temperature by heating inside the chamber 130, and in the embodiment of the present invention, the thermoplastic powder is PEEK (Polyetheretherketone) having a melting point at 343 °C is adopted, the chamber 130 Is preferably controlled by the heater 132 so that the temperature is 320° C. lower than the melting point of PEEK.

On the other hand, the heater 132 is in a state of heating at a higher temperature in order to maintain the interior of the chamber 130 at about 320°C, and the heat is generated even while the laser irradiator 152 shoots a beam to form the 3D molded product (P). Therefore, since the bottom of the chamber 130 is made of metal, it can be heated to the melting point of the thermoplastic powder (343°C in the case of PEEK) or higher by continuously absorbing heat.

In this case, the thermoplastic powder supplied in the right direction by the operation of the powder supply unit 134 is melted in contact with the bottom before reaching the molding space 150 so that it can be pressed.

To this end, the curing prevention unit 160 is operated. The curing prevention unit 160 includes a fluid guide pipe 162 for guiding a fluid to pass through the bottom of the chamber 130, and a fluid forcing device 164 for forcing fluid movement to the fluid guide pipe 162. ), and a heat insulating member 166 for partitioning a cooling portion at the bottom of the chamber 130.

The fluid guide pipe 162 is configured to guide cold gas or liquid to be recovered to the fluid forcing machine 164 through a portion to be cooled in the chamber 130, and is formed with the powder storage space 140 It was configured to be built inside the floor except for the space 150.

That is, in the embodiment of the present invention, the fluid guide pipe 162 is on the left side of the powder storage space 140, between the powder storage space 140 and the molding space 150, the molding space 150 and the powder collection unit 180 It is installed in between to prevent the thermoplastic powder from sticking to the bottom by absorbing heat from the upper side, and to prevent interference when the powder supply unit 134 is operated.

The fluid forcing device 164 is a configuration for forcibly moving an object to which various types of materials such as gas or liquid capable of absorbing heat are applicable, and a pump may be applied, and the gas or liquid heated by absorbing heat is stored inside. It may be configured to cool again while passing through.

The heat insulating member 166 is a configuration that insulates a portion to be cooled and a portion to be maintained at a relatively high temperature so as not to be influenced by each other. In the embodiment of the present invention, the powder storage space 140 and the molding space It was configured to be located between 150.

In addition, an auxiliary heater 159 is provided outside the left wall of the molding space 150 to prevent the three-dimensional molded product P inside the molding space 150 from rapidly contracting.

The auxiliary heater 159 is configured to generate heat lower than that of the heater 132, and is arranged to surround the molding space 150 from the outside.

The scope of the present invention is not limited to the embodiments illustrated above, and many other modifications based on the present invention will be possible for those skilled in the art within the above technical scope.

100. 3D printer 110. Case
112. Door 120. Control unit
130. Chamber 132. Heater
134. Powder supply unit 140. Powder storage space
150. Molding space 152. Laser irradiation machine 154. Output plate 156. Cylinder
158. Support plate 159. Auxiliary heater
160. Curing prevention unit 162. Fluid guide pipe
164. Fluid forcing machine 166. Insulation member
170. Atmosphere creation unit 180. Powder recovery unit
P. 3D molded product

Claims (4)

A case forming an exterior and having a chamber selectively sealed inside,
A powder storage space for storing the thermoplastic powder inside the case,
A molding space that communicates with the powder storage space and forms a three-dimensional molded product,
A powder supply unit for transferring the powder from the powder storage space to the molding space through the bottom of the chamber,
A plurality of heaters for heating the interior of the chamber,
And a curing prevention unit cooling the bottom of the chamber, which is the transfer path of the powder, to a temperature below the melting point of the thermoplastic powder,
The curing prevention unit,
A fluid guide tube for guiding the fluid to pass through the bottom of the chamber,
A fluid forcing device for forcing fluid movement to the fluid guide tube,
3D printer with a curing prevention unit, characterized in that it comprises a heat insulating member for partitioning the cooling portion at the bottom of the chamber.
delete The method of claim 1, wherein the fluid guide tube,
A 3D printer with a curing prevention unit, characterized in that it is embedded inside the bottom part excluding the powder storage space and the molding space.
The 3D printer with a curing prevention unit according to claim 3, wherein an auxiliary heater is provided outside the molding space to heat the three-dimensional molded article by generating heat with lower heat than the heater.

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