KR20210070160A - Apparatus for pellet supply and method for pellet supply - Google Patents

Abstract

Provided is a pellet supply device including: a supply chamber for receiving pellets; a rotating unit connected to a driving unit; and a supply unit coupled to the supply chamber. The rotating unit includes: a rotary shaft extending in a first direction; a screw coupled to the outer surface of the rotary shaft and proceeding in the first direction; and a scraper extending from the outer surface of the rotary shaft in a direction crossing the first direction. The supply unit surrounds the screw. The scraper is positioned above the screw and is disposed within the supply chamber.

Description

Pellet supply apparatus and pellet supply method {Apparatus for pellet supply and method for pellet supply}

The present invention relates to a pellet supply apparatus and a pellet supply method, and more particularly, to a pellet supply apparatus and a pellet supply method capable of uniform extrusion of pellets.

3D printing is a processing method that creates a three-dimensional shape by laminating materials, and there are several specific methods. For example, FDM (Fused Deposition Modeling) refers to a method of making a three-dimensional shape by laminating a two-dimensional cross-sectional shape by melting a filament-type material with heat. In FDM, after melting a thermoplastic polymer or the like at a high temperature, it must be preceded by using an extruder to produce a wire-shaped filament. In order to make a polymer material or the like into a filament form, an appropriate viscosity, extrusion rate, and cooling rate are required. In order to increase the strength or improve the thermal stability of the material, materials such as inorganic materials may be mixed. As another method for 3D printing, a thermoplastic polymer or the like may be used in pellet form. In the case of using a material in the form of pellets, pellets in a small form can be put into a small precision extruder for a 3D printer in large quantities using a chamber.

The problem to be solved by the present invention is to provide a pellet supply apparatus and a pellet supply method capable of uniformly extruding the pellets.

The problem to be solved by the present invention is to provide a pellet supply device and a pellet supply method that can prevent the bottleneck of the pellets at the inlet of the supply.

The problem to be solved by the present invention is to provide a pellet supply device and a pellet supply method capable of removing the pores in the supply unit.

The problem to be solved by the present invention is to provide a pellet supply apparatus and a pellet supply method that can prevent premature melting of the pellets.

The problem to be solved by the present invention is to provide a pellet supply device and a pellet supply method that can prevent the pellets from being clogged by the melting of the pellets.

The problem to be solved by the present invention is to provide a pellet supply apparatus and a pellet supply method that can be used for 3D printing various materials.

The problem to be solved by the present invention is to provide a pellet supply apparatus and a pellet supply method that can simplify the process.

The problems to be solved by the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, the pellet supply device according to an embodiment of the present invention is a supply chamber for accommodating the pellets; a rotating unit connected to the driving unit; and a supply unit coupled to the supply chamber; Including, wherein the rotating part: a rotating shaft extending in a first direction; a screw coupled to the outer surface of the rotation shaft and proceeding in the first direction; and a scraper extending from an outer surface of the rotation shaft in a direction crossing the first direction. including, wherein the supply unit surrounds the screw, and the scraper is positioned above the screw, and may be disposed in the supply chamber.

In order to achieve the above object, in the pellet supply apparatus according to an embodiment of the present invention, the extension direction of the scraper may be perpendicular to the first direction.

In order to achieve the object to be solved, the pellet supply device according to an embodiment of the present invention may include the scraper rod shape.

In order to achieve the object to be solved, the pellet supply device according to an embodiment of the present invention may be spaced upward by 0.5mm to 2mm from the upper boundary of the scraper the supply unit.

In order to achieve the above object, the pellet supply device according to an embodiment of the present invention may have a length in an extension direction of the scraper longer than a length in an extension direction of the scraper of the screw.

In order to achieve the above object, the pellet supply device according to an embodiment of the present invention provides a pellet accommodating space in which the supply chamber is narrowed in diameter toward the first direction, the pellet accommodating space is the supply part The supply chamber body connected to the inner space and defining the pellet receiving space may provide a refrigerant receiving hole therein.

In order to achieve the above object, the pellet supply device according to an embodiment of the present invention further comprises a heating unit coupled to the outer surface of the supply unit, wherein the heating unit can heat the pellets supplied to the inner space of the supply unit have.

In order to achieve the above object, the pellet supply device according to an embodiment of the present invention is a supply chamber for accommodating the pellets; a rotating unit connected to the driving unit; and a supply unit coupled to the supply chamber; Including, wherein the rotating part: a rotating shaft extending in a first direction; and a screw coupled to an outer surface of the rotation shaft and proceeding in the first direction. Including, wherein the supply unit surrounds the screw, the supply chamber includes a supply chamber body and a pellet accommodating space defined by the supply chamber body, the pellet accommodating space is narrower in diameter toward the first direction It is connected to the internal space of the supply unit, and the supply chamber body may provide a refrigerant accommodating hole therein.

In order to achieve the above object, the pellet supply apparatus according to an embodiment of the present invention may surround a portion of the supply part and the pellet receiving space in which the refrigerant receiving hole is provided.

In order to achieve the above object, the pellet supply device according to an embodiment of the present invention further comprises a refrigerant inlet and a refrigerant outlet coupled to the outside of the supply chamber, wherein the refrigerant inlet and the refrigerant outlet are the refrigerant receiving It can be connected to the ball.

In order to achieve the above object, the pellet supply device according to an embodiment of the present invention may be located above the refrigerant outlet than the refrigerant inlet.

In order to achieve the above object, the pellet supply device according to an embodiment of the present invention may further include a refrigerant pump connected to the refrigerant outlet or the refrigerant inlet.

The pellet supply method according to an embodiment of the present invention in order to achieve the above object is to supply the pellets to the supply chamber; a scraper in the feed chamber pushing the pellets towards the feed; And the screw located in the supply unit rotates forward to push the pellet down; Including, wherein the scraper is coupled to the upper side of the rotation shaft to which the screw is coupled, it may be located in the supply chamber.

In order to achieve the above object, the pellet supply method according to an embodiment of the present invention further comprises pushing the pellet upward by rotating the screw backward after the screw rotates forward and pushes the pellet down. can do.

In order to achieve the above object, the pellet supply method according to an embodiment of the present invention may have a ratio of the forward rotation and the reverse rotation of 5:1 to 15:1.

In order to achieve the above object, the pellet supply method according to an embodiment of the present invention may further include supplying a refrigerant to the refrigerant receiving hole in the supply chamber.

Specific details of other embodiments are included in the detailed description and drawings.

According to the pellet supply apparatus and the pellet supply method according to an exemplary embodiment of the present invention, the pellets can be uniformly extruded.

According to the pellet supply apparatus and the pellet supply method according to an exemplary embodiment of the present invention, it is possible to prevent the bottleneck of the pellets at the inlet of the supply.

According to the pellet supply apparatus and the pellet supply method according to an exemplary embodiment of the present invention, it is possible to remove the pores in the supply unit.

According to the pellet supply apparatus and the pellet supply method according to an exemplary embodiment of the present invention, it is possible to prevent premature melting of the pellets.

According to the pellet supply apparatus and the pellet supply method according to an exemplary embodiment of the present invention, it is possible to prevent the pellets from being clogged by the melting of the pellets.

According to the pellet supply apparatus and the pellet supply method according to an exemplary embodiment of the present invention, various materials can be used for 3D printing.

According to the pellet supply apparatus and the pellet supply method according to an exemplary embodiment of the present invention, the process can be simplified.

Effects of the present invention are not limited to the above-mentioned problems, and other effects not mentioned will be clearly understood by those skilled in the art from the following description.

1 is a cross-sectional view showing a pellet supply device according to an exemplary embodiment of the present invention.
FIG. 2 is an enlarged cross-sectional view of a portion X of FIG. 1 .
3 is a flowchart illustrating a method for supplying pellets according to an exemplary embodiment of the present invention.
4 to 8 are cross-sectional views sequentially showing the pellet supply method according to FIG.

In order to fully understand the configuration and effects of the technical idea of the present invention, preferred embodiments of the technical idea of the present invention will be described with reference to the accompanying drawings. However, the technical spirit of the present invention is not limited to the embodiments disclosed below, and may be implemented in various forms and various changes may be made. However, it is provided so that the disclosure of the technical idea of the present invention is complete through the description of the present embodiments, and to fully inform those of ordinary skill in the art to which the present invention belongs, the scope of the invention.

Parts indicated with like reference numerals throughout the specification indicate like elements. Embodiments described in this specification will be described with reference to a block diagram, a perspective view, and/or a cross-sectional view that is an ideal illustration of the technical idea of the present invention. In the drawings, the thickness of the regions is exaggerated for effective description of technical content. Accordingly, the regions illustrated in the drawings have a schematic nature, and the shapes of the regions illustrated in the drawings are intended to illustrate specific shapes of regions of the device and not to limit the scope of the invention. In various embodiments of the present specification, various terms are used to describe various elements, but these elements should not be limited by these terms. These terms are only used to distinguish one component from another. The embodiments described and illustrated herein also include complementary embodiments thereof.

The terminology used herein is for the purpose of describing the embodiments and is not intended to limit the present invention. As used herein, the singular also includes the plural unless specifically stated otherwise in the phrase. As used herein, the terms 'comprises' and/or 'comprising' do not exclude the presence or addition of one or more other components.

Hereinafter, the present invention will be described in detail by describing preferred embodiments of the technical idea of the present invention with reference to the accompanying drawings.

1 is a cross-sectional view showing a pellet supply device according to an exemplary embodiment of the present invention.

Hereinafter, D1 of FIG. 1 may be referred to as a first direction, D2 may be referred to as a second direction, and D3 substantially perpendicular to the first and second directions D1 and D2 may be referred to as a third direction.

Referring to FIG. 1 , a pellet feeding device may be provided. The pellet feeder can be used for 3D printing. That is, the pellet feeding device may be part of the 3D printer. The pellet supply device may perform the function of extruding the printing material in the 3D printing process. The pellet supply apparatus may include a supply chamber (1), a supply unit (3), a rotating unit (5), a heating unit (7), a driving unit (m), a pellet feeder (U) and a refrigerant pump (P) and the like.

The feed chamber 1 may receive pellets (see a, FIG. 4, etc.). The supply chamber 1 may supply the pellets (a) to the supply part (3). The feed chamber 1 may be connected to a pellet feeder U. The supply chamber 1 may receive the pellets from the pellet feeder (U). The supply chamber 1 may receive the pellets from the pellet feeder U, and supply it to the supply unit 3 . The chamber 1 may include a supply chamber body 11 , an extension body 15 , an inlet 13 , a refrigerant inlet 11i and a refrigerant outlet 11e , and the like.

The supply chamber body 11 may define a pellet receiving space 11h. That is, the supply chamber body 11 may surround the pellet receiving space (11h). In embodiments, the outer shape of the supply chamber body 11 may include a cylindrical shape. However, the present invention is not limited thereto. The pellets (a) may be accommodated in the pellet receiving space (11h). The diameter of the pellet accommodating space 11h may become narrower toward the first direction D1. That is, the diameter of the inner surface (11s) of the pellet receiving space (11h) may be smaller toward the bottom. The pellet receiving space (11h) may be connected to the inner space (31h) of the supply unit (3). The pellets (a) accommodated in the pellet receiving space (11h) may be supplied to the inner space (31h) of the supply unit (3). The supply chamber body 11 may provide a refrigerant receiving hole 11hi. More specifically, a refrigerant accommodating hole 11hi may be provided in the supply chamber body 11 . The refrigerant accommodating hole 11hi may not be connected to the pellet accommodating space 11h. That is, the refrigerant accommodating hole 11hi may be separated from the pellet accommodating space 11h by the supply chamber body 11 . The refrigerant receiving hole 11hi may surround the pellet receiving space 11h. More specifically, the refrigerant accommodating hole 11hi may surround the pellet accommodating space 11h from the outside. The refrigerant receiving hole 11hi may surround a portion of the supply unit 3 . More specifically, the refrigerant receiving hole 11hi may surround the upper portion of the supply unit 3 from the outside. The supply chamber body 11 may be coupled to the refrigerant inlet 11i and the refrigerant outlet 11e. The refrigerant inlet 11i may be located on the outer surface of the supply chamber body 11 . The refrigerant outlet 11e may be located on the outer surface of the supply chamber body 11 . The refrigerant outlet 11e may be located above the refrigerant inlet 11i. The refrigerant receiving hole 11hi may be connected to the refrigerant inlet 11i. The refrigerant receiving hole 11hi may be connected to the refrigerant outlet 11e. A refrigerant may be located in the refrigerant receiving hole 11hi. The refrigerant may be supplied to the refrigerant receiving hole 11hi through the refrigerant inlet 11i. The refrigerant may exit from the refrigerant receiving hole 11hi through the refrigerant outlet 11e. Details on this will be described later.

The extended body 15 may be coupled to the supply chamber body 11 . The extension body 15 may extend upwardly from the supply chamber body 11 . The extended body 15 may have a cylindrical shape. However, the present invention is not limited thereto. The extension body 15 may define an extension receiving hole 15h. That is, the extension accommodating hole 15h may be provided inside the extension body 15 . The extension accommodating hole 15h may be connected to the pellet accommodating space 11h.

The input unit 13 may be coupled to the extension body 15 and/or the supply chamber body 11 , and the like. Hereinafter, for convenience of description, it is illustrated that the input unit 13 is coupled to the extension body 15 . In some embodiments, the input unit 13 may form a predetermined angle with the first direction D1. The input unit 13 may provide an input passage 13h. The input passage 13h may be connected to the extension accommodating hole 15h and/or the pellet accommodating space 11h. The pellets (a) may be supplied to the extension accommodating hole 15h and/or the pellet accommodating space 11h through the input passage 13h. The input passage (13h) may be connected to the pellet feeder (U). The input passage (13h) may receive the pellets (a) from the pellet feeder (U). The pellets (a) supplied from the pellet feeder (U) may be supplied to the extension receiving hole (15h) and/or the pellet receiving space (11h) along the input passage (13h).

The refrigerant inlet 11i may be coupled to the outer surface of the supply chamber body 11 . The refrigerant inlet 11i may be connected to an inlet pipe Pi or the like. The refrigerant inlet 11i may receive refrigerant from an inlet pipe Pi or the like. The refrigerant inlet 11i may transfer the refrigerant supplied from the inlet pipe Pi to the pellet receiving space 11h.

The refrigerant outlet 11e may be coupled to the outer surface of the supply chamber body 11 . The refrigerant outlet 11e may be connected to an outlet pipe Pe or the like. The refrigerant outlet 11e may discharge the refrigerant through an outlet pipe Pe or the like. The refrigerant outlet 11e may be located at a higher position than the refrigerant inlet 11i. More specifically, the refrigerant inlet 11i may be located in the first direction D1 than the refrigerant outlet 11e.

The supply part 3 may be coupled to the supply chamber 1 . The supply unit 3 may include a supply pipe 31 and a nozzle 33 .

The supply pipe 31 may be coupled to the supply chamber body 11 . More specifically, the supply pipe 31 may be coupled to the center of the supply chamber body 11 . The supply pipe 31 may extend in the first direction D1 . The supply pipe 31 may extend in the first direction D1 from the supply chamber body 11 . The supply pipe 31 may provide an internal space 31h. The inner space 31h may extend in the first direction D1 along the supply pipe 31 . The inner space 31h may be connected to the pellet receiving space 11h. The pellets (a, see FIG. 4, etc.) may move from the pellet receiving space 11h to the inner space 31h.

The nozzle 33 may be coupled to the supply pipe 31 . More specifically, the nozzle 33 may be coupled to the lower end of the supply pipe 31 . The diameter of the nozzle 33 may decrease in the first direction D1. The nozzle 33 may provide a connection hole 33h and a discharge port 33e. The connection hole 33h may be connected to the inner space 31h of the supply pipe 31 . The diameter of the connection hole 33h may decrease in the first direction D1. The discharge port 33e may be connected to the connection hole 33h. The discharge port 33e may be connected to the outside. The connection hole 33h may be connected to the outside through the outlet 33e.

The rotating part 5 may include a rotating shaft 51 , a screw 53 , a connecting shaft 55 , and a scraper 57 .

The rotation shaft 51 may extend in the first direction D1 . The rotation shaft 51 may be located in the supply pipe 31 . The rotation shaft 51 may be connected to the connection shaft 55 . The rotating shaft 51 may be rotated by the connecting shaft 55 . More specifically, the rotation shaft 51 may be rotated clockwise and counterclockwise by receiving a rotational force from the driving unit m through the connecting shaft 55 . Details on this will be described later with reference to FIGS. 4 to 8 .

The screw 53 may be coupled to the rotation shaft 51 . More specifically, the screw 53 may be coupled to the outer surface of the rotation shaft 51 . The screw 53 may be coupled to the outer surface of the rotation shaft 51 to proceed in the first direction D1 . Details of the screw 53 will be described later.

The connection shaft 55 may be coupled to the upper side of the rotation shaft 51 . The connection shaft 55 may extend in the first direction D1 . At least a portion of the connecting shaft 55 may be located in the supply chamber 1 . The connecting shaft 55 may be connected to the driving unit m. The connection shaft 55 may transmit the rotational force of the driving unit m to the rotation shaft 51 .

The scraper 57 may be coupled to the rotation shaft 51 or the connection shaft 55 . When the scraper 57 is coupled to the rotation shaft 51 , the scraper 57 may be coupled to the upper side of the rotation shaft 51 . The scraper 57 may be positioned above the screw 53 . The scraper 57 may include a rod shape. An extension direction of the scraper 57 may intersect the first direction D1 . For example, the extension direction of the scraper 57 may be substantially perpendicular to the first direction D1 . More specifically, the extension direction of the scraper 57 may be located on a plane defined by the second direction D2 and the third direction D3 . Details of the scraper 57 will be described later with reference to FIG. 2 and the like.

The heating unit 7 may heat the supply unit 3 . The heating unit 7 may be coupled to the supply unit 3 . For example, the heating unit 7 may be coupled to the lower end of the supply pipe (31). The heating unit 7 may heat the pellets (a) in the inner space (31h) of the supply pipe (31). The heating unit 7 may include a heating wire 73 and a support member 71 . The heating wire 73 may receive electrical energy from an external power source (not shown). When the heating wire 73 receives electrical energy, it may generate Joule heat. The heating wire 73 may transfer heat to the inner space 31h of the supply pipe 31 . The pellet (a) may be partially or completely melted by heat. The support member 71 may fix the heating wire 73 .

The driving unit m may be connected to the connecting shaft 55 . The driving unit m may provide a turning force to the connecting shaft 55 . The driving unit m may include various means for providing rotational force. For example, the driving unit m may include a motor or the like. However, the present invention is not limited thereto.

The pellet feeder (U) may be connected to the input unit (13). The pellet feeder (U) may supply the pellets (a). The pellet feeder (U) may supply the pellets (a) to the input unit (13).

The refrigerant pump P may supply refrigerant to the refrigerant accommodating hole 11hi. The refrigerant pump P may be connected to the refrigerant inlet 11i and/or the refrigerant outlet 11e. More specifically, the refrigerant pump P may be connected to the refrigerant inlet 11i through the inlet pipe Pi, or may be connected to the refrigerant outlet 11e through the outlet pipe Pe.

FIG. 2 is an enlarged cross-sectional view of a portion X of FIG. 1 .

Referring to FIG. 2 , the scraper 57 may be positioned on the screw 53 . The scraper 57 may be located above the supply unit 3 . That is, the scraper 57 may be located in the supply chamber 1 . More specifically, the scraper 57 may be located inside the supply chamber body 11 . In other words, the scraper 57 may be located in the pellet receiving space 11h. The scraper 57 may be spaced apart from the supply unit 3 in a direction opposite to the first direction D1 . That is, the scraper 57 may be spaced upward from the upper boundary of the supply unit 3 . For example, the scraper 57 may be spaced apart by h from the upper boundary of the supply pipe 31 . In embodiments, h may be 0.5 mm or more and 2 mm or less.

The length L of the scraper 57 in the extending direction may be longer than the length L' of the screw 53 in the extending direction of the scraper 57 . That is, the scraper 57 may extend more outwardly from the rotation shaft 51 than the screw 53 . For example, the scraper 57 may extend outwardly from the rotation shaft 51 , and an outer portion of the scraper 57 may be located above the supply pipe 31 .

The refrigerant accommodating hole 11hi may surround a part or all of the upper part of the supply pipe 31 and/or the pellet accommodating space 11h. The refrigerant located in the refrigerant accommodating hole 11hi may absorb heat from a part or all of the upper portion of the supply pipe 31 and/or the pellet accommodating space 11h. Details on this will be described later.

3 is a flowchart illustrating a method for supplying pellets according to an exemplary embodiment of the present invention.

Referring to FIG. 3, the pellet supply method (S) is to supply the pellets to the supply chamber (S1), the scraper pushes the pellets (S2), the screw rotates forward to push the pellets down (S3) And the screw rotates in reverse to push the pellet upward (S4).

Hereinafter, each process of the pellet supply method (S) will be described in detail with reference to FIGS. 4 to 8 .

4 to 8 are cross-sectional views sequentially showing the pellet supply method according to FIG.

Referring to FIGS. 3 and 4 , supplying the pellets to the supply chamber ( S1 ) may include supplying the pellets (a) to the input unit 13 from the pellet supply (U). The pellets (a) may contain materials from 3D printing. For example, the pellet (a) may include a polymer material. More specifically, the pellets (a) may include a thermoplastic polymer. The pellets (a) may further contain other materials for increased strength and/or thermal stability. For example, the pellet (a) may further include various inorganic substances. In addition, the pellets (a) may include various materials for 3D printing. The pellets (a) may have the form of small grains. The pellets (a) injected into the input passage (13h) of the input unit 13 may move downward by gravity. That is, the pellets (a) may move from the input passage (13h) to the pellet receiving space (11h). Pellets for 3D printing may be stacked in the pellet receiving space 11h.

Referring to FIGS. 3 and 5 , the scraper pushing the pellets ( S2 ) may include rotating the rotating unit 5 by the driving unit m. More specifically, the connecting shaft 55 may be rotated by the driving of the driving unit m. The forward rotation direction of the connecting shaft 55 may be determined according to the traveling direction of the screw 53 . For example, if the screw 53 proceeds in a clockwise direction, rotation of the connecting shaft 55 in a clockwise direction may be a forward rotation. Conversely, if the screw 53 proceeds in the counterclockwise direction, the rotation of the connecting shaft 55 in the counterclockwise direction may be a forward rotation. When the connecting shaft 55 rotates forward, the rotation shaft 51 may also rotate forward. By the forward rotation of the rotation shaft 51 , the scraper 57 and the screw 53 may rotate forward. The scraper 57 rotates and can push the pellets (a) in the pellet receiving space (11h). More specifically, the scraper 57 may rotate and push the pellets (a) up and/or down, and the like. As the scraper 57 pushes the pellets (a), it is possible to prevent the pellets (a) from colliding with each other and clogging the pellets (a) without going down. Therefore, the bottleneck phenomenon of the pellets (a) at the inlet of the supply unit (3) can be prevented.

According to the pellet supply apparatus and the pellet supply method according to exemplary embodiments of the present invention, it is possible to send the pellets from the supply chamber to the supply pipe using a scraper. That is, the scraper stirs the pellets collected at the bottom of the supply chamber, thereby preventing the pellets from clogging by the bottleneck. Therefore, the pellets can be smoothly supplied to the supply pipe. Accordingly, uniform extrusion of the pellets may be possible. And the uniformity of 3D printing can be improved.

According to the pellet supply apparatus and the pellet supply method according to exemplary embodiments of the present invention, even using a material in the form of a pellet, not a filament form, uniform extrusion may be possible. Therefore, it may not be necessary to make the filament form in advance. Accordingly, the process may be simplified and the manufacturing cost may be reduced. In addition, a material having an increased content of various inorganic substances may be used. Therefore, the thermal stability and strength of the material can be improved.

Referring to FIG. 6 , the pellets a may be pushed by the scraper 57 to move in the first direction D1 . The bottleneck caused by the collision between the pellets (a) is prevented, and the pellets (a) can be uniformly supplied to the supply pipe (31).

2, 5 and 6, the screw rotates forward and pushes the pellet down (S3) is the pellet (a) supplied to the supply pipe 31 by the scraper 57, the screw 53 may include pushing down. The screw 53 rotates forward and can push the pellets (a) in the first direction (D1) along the supply pipe 31. Accordingly, the pellets (a) can be continuously pushed down.

2 and 7, the screw rotates in reverse to push the pellet upward (S4), and after the screw 53 repeats the forward rotation a predetermined number of times, it may include reverse rotation. In embodiments, the ratio of the forward rotation and the reverse rotation may be 5:1 to 15:1. The ratio of the forward rotation and the reverse rotation of the screw 53 may be determined in various ways. In embodiments, the ratio of the forward rotation and the reverse rotation of the screw 53 may be determined according to the diameter of the nozzle 33 and/or the printing speed of the 3D printer. For example, when the diameter of the nozzle 33 is 400um to 600um and the printing speed is 30mm/sec, the ratio of the forward rotation and the reverse rotation of the screw 53 may be 10:1. That is, after the screw 53 rotates forward 5 turns, the screw 53 may reverse rotate 0.5 turns. When the diameter of the nozzle 33 is increased, the ratio of the forward rotation may be increased. Conversely, when the diameter of the nozzle 33 decreases, the rate of forward rotation may decrease. In addition to this, the ratio of the forward rotation of the screw 53 may vary according to the constituents and/or types of the pellets (a).

Referring to Figure 8, when the screw 53 is rotated in reverse, the pellet (a) can go up. That is, the pellet (a), which went down in the first direction (D1), may be retrograde upward. A portion of the pellets (a) located above the supply pipe 31 may be deviated from the supply pipe 31 . The pellets (a) can be returned to the feed chamber (1). That is, the pellets (a) may return to the pellet receiving space (11h).

Referring back to FIG. 2 , when the reverse rotation of the screw 53 is finished, the screw 53 may rotate forward again. The forward rotation and reverse rotation of the screw 53 may be repeated according to a predetermined ratio.

According to the pellet supply apparatus and the pellet supply method according to exemplary embodiments of the present invention, the screw may repeat forward rotation and reverse rotation. Accordingly, pores and the like formed between the pellets in the supply pipe may be discharged to the supply chamber. Accordingly, uniform extrusion through the nozzle of the pellets may be possible.

In embodiments, the pellet supply method (S) may further include supplying a refrigerant to the refrigerant receiving hole in the supply chamber. That is, the refrigerant may be supplied to the refrigerant accommodating hole 11hi by the refrigerant pump P. The refrigerant may be supplied to the refrigerant receiving hole 11hi through the refrigerant inlet 11i. The refrigerant may include various materials capable of absorbing heat. In embodiments, the refrigerant may include a secondary refrigerant having no phase change. For example, the refrigerant may include water. However, the present invention is not limited thereto, and the refrigerant may include other materials. The refrigerant may be located in the refrigerant receiving hole 11hi to absorb heat from a portion of the supply pipe 31 and/or the pellet receiving space 11h. The supply of the refrigerant may be performed at various times. For example, the refrigerant may be supplied to the refrigerant accommodating hole 11hi in advance before the pellets (a) are put into the pellet accommodating space 11h. Alternatively, the refrigerant may be supplied to the refrigerant accommodating hole 11hi after the pellet (a) goes down along the supply pipe 31 and is heated by the heating unit 7 .

According to the pellet supply apparatus and the pellet supply method according to exemplary embodiments of the present invention, it is possible to cool a portion of the supply pipe and / or the pellet receiving space using a refrigerant. That is, the refrigerant may absorb heat from a portion of the supply pipe and/or from the pellets disposed in the pellet receiving space. Accordingly, it is possible to prevent the pellets from being melted prematurely by heat conducted from the heating unit in a portion of the supply pipe and/or in the pellet receiving space. Accordingly, it is possible to prevent the pellets from being melted prematurely and sticking to the wall surface of the supply pipe and/or the screw surface. And thereby, uniform extrusion of the pellets may be possible.

According to the pellet supply apparatus and the pellet supply method according to exemplary embodiments of the present invention, the refrigerant outlet may be located above the refrigerant inlet. Therefore, the low-temperature refrigerant can absorb heat from the pellets located closer to the heating part. Accordingly, cooling of the pellets can be performed effectively.

As described above, embodiments of the present invention have been described with reference to the accompanying drawings, but those of ordinary skill in the art to which the present invention pertains can implement the present invention in other specific forms without changing the technical spirit or essential features. You can understand that there is Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive.

1: Feed chamber
3: supply
5: Rotating part
7: heating part
m: drive
P: refrigerant pump

Claims (16)

a feed chamber containing the pellets;
a rotating unit connected to the driving unit; and
a supply unit coupled to the supply chamber; including,
The rotating part:
a rotation axis extending in a first direction;
a screw coupled to the outer surface of the rotation shaft and proceeding in the first direction; and
a scraper extending from an outer surface of the rotation shaft in a direction crossing the first direction; including,
The supply part surrounds the screw,
The scraper is positioned above the screw, but the pellet feeding device is disposed in the feeding chamber.
The method of claim 1,
The extension direction of the scraper is a pellet supply device perpendicular to the first direction.
The method of claim 1,
The scraper is a pellet supply device comprising a rod shape.
The method of claim 1,
The scraper is a pellet supply device that is spaced up by 0.5mm ~ 2mm from the upper boundary of the supply.
The method of claim 1,
The length in the extension direction of the scraper is longer than the length of the screw in the extension direction of the scraper.
The method of claim 1,
The supply chamber provides a pellet receiving space whose diameter is narrowed toward the first direction,
The pellet receiving space is connected to the internal space of the supply,
The supply chamber body defining the pellet accommodating space is a pellet supply device that provides a refrigerant receiving hole therein.
The method of claim 1,
Further comprising a heating unit coupled to the outer surface of the supply unit,
The heating unit is a pellet supply device for heating the pellets supplied to the inner space of the supply unit.
a feed chamber containing the pellets;
a rotating unit connected to the driving unit; and
a supply unit coupled to the supply chamber; including,
The rotating part:
a rotation axis extending in a first direction; and
a screw coupled to the outer surface of the rotation shaft and proceeding in the first direction; including,
The supply part surrounds the screw,
The feed chamber comprises a feed chamber body and a pellet receiving space defined by the feed chamber body,
The pellet receiving space is narrower in diameter toward the first direction, and is connected to the inner space of the supply unit,
The supply chamber body is a pellet supply device that provides a refrigerant receiving hole therein.
9. The method of claim 8,
The refrigerant receiving hole is a pellet supply unit surrounding a portion of the supply and the pellet receiving space.
9. The method of claim 8,
Further comprising a refrigerant inlet and a refrigerant outlet coupled to the outside of the supply chamber,
The refrigerant inlet and the refrigerant outlet is a pellet supply device that is connected to the refrigerant receiving hole.
11. The method of claim 10,
The refrigerant outlet is a pellet supply device located above the refrigerant inlet.
12. The method of claim 11,
The pellet supply device further comprising a refrigerant pump connected to the refrigerant outlet or the refrigerant inlet.
feeding pellets into the feeding chamber;
a scraper in the feed chamber pushing the pellets towards the feed; and
The screw located in the supply unit rotates forward to push the pellet down; including,
The scraper is coupled to the upper side of the rotation shaft to which the screw is coupled, the pellet supply method located in the supply chamber.
14. The method of claim 13,
After the screw is rotated forward to push the pellet down, the screw rotates in reverse to push the pellet upward.
15. The method of claim 14,
The ratio of the forward rotation and the reverse rotation is 5:1 to 15:1 pellet feeding method.
14. The method of claim 13,
Pellet supply method further comprising supplying a refrigerant to the refrigerant receiving hole in the supply chamber.

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