WO2024010395A1

WO2024010395A1 - Impurity removal device, 3d printer comprising same, and internal gas control method using same

Info

Publication number: WO2024010395A1
Application number: PCT/KR2023/009581
Authority: WO
Inventors: 최준필; 이필호; 하태호; 허세곤; 정민교; 송여울; 김용래; 이창우
Original assignee: 한국기계연구원
Priority date: 2022-07-06
Filing date: 2023-07-06
Publication date: 2024-01-11
Also published as: KR20240006327A

Abstract

An impurity removal device and an internal gas control method using same are disclosed. An embodiment of the present invention can remove traces of impurities contained in inert gas and supply the gas to a printing unit. Accordingly, the printing unit can be prevented from printing a defective product due to the traces of impurities.

Description

Impurity removal device, 3D printer including same, and internal gas control method using the same

The present invention relates to an impurity removal device for a 3D printer, a 3D printer including the same, and an internal gas control method using the same. In particular, the present invention relates to an impurity removal device capable of reducing the oxygen content in an inert gas supplied to a 3D printer, an impurity removal device for a 3D printer, a 3D printer including the same, and an internal gas control method using the same. .

3D printers can be customized based on a high degree of freedom and precision in the manufacturing shape, so they are used to produce small quantities of customized products. There are various types of 3D printers for manufacturing small quantity customized products, but metal 3D printers such as PBF (powder bed fusion) and DED (direct energy deposition) are recognized as the most preferred printers for small quantity customized manufacturing. .

The PBF method and the DED method are printing methods using metal powder. Generally, in PBF, spherical powder with a size of 10 to 50 ㎛ is used, and in the DED method, spherical powder with a size of 50 to 150 ㎛ is used. It is utilized. Metal powders are manufactured from various materials such as titanium, aluminum, stainless steel, nickel, and chrome, depending on the field of application.

However, the 3D printers currently being used in this way also have problems that must be solved, one of which is reducing oxygen concentration.

Currently, 3D printers are designed to operate in an inert gas (eg, argon, nitrogen) atmosphere with a very low oxygen concentration. However, as products develop or the number of fields requiring precise work increases, even this small amount of oxygen becomes a problem.

In particular, this insufficient amount of oxygen is becoming a problem in fields that manufacture high-tech products such as eco-friendly automobiles, power generation, robots, electrical/electronic devices, and medical fields. In this field, products are mostly printed using metal powders with high oxygen affinity, such as aluminum, magnesium, titanium, chromium, and rare earth elements. At this time, residual stress, distortion, cracks, surface defects, etc. are caused by the minute oxygen contained in the inert gas. This is happening.

Since 3D printers take a lot of time to print products, defects in a few of these products cause similar or greater damage than manufacturing multiple defective products in mass-produced products.

Accordingly, calls for a 3D printer that solves these problems are increasing recently.

The present invention according to one embodiment solves the above-mentioned problem, and includes an impurity removal device for a 3D printer that can prevent defective products from being printed by removing an insignificant amount of oxygen, a 3D printer including the same, and internal gas control using the same. The purpose is to provide a method.

An impurity removal device for a 3D printer according to an embodiment includes a gas supply unit that supplies gas, and a removal body that receives the gas from the gas supply unit and removes impurities, and applies a set temperature to the removal body to remove the gas. It may include a removal unit that removes impurities contained in the gas.

The remover may contain any one pure metal selected from titanium, magnesium, aluminum, and calcium.

The set temperature may range from 200 degrees to 1200 degrees.

The removal body may include an alloy containing at least one of magnesium, aluminum, calcium, iron, and silicon.

The set temperature may range from 500 degrees to 1000 degrees.

A filter unit that removes impurities may be disposed between the gas supply unit and the removal unit.

The filter unit is composed of a plurality of filter units, and each filter unit may include a flow path connected to each other.

The filter unit can remove moisture or carbon dioxide when the gas passes through it.

It may further include a mixing section for mixing powder and gas.

The mixing unit may include a supply hopper unit that supplies powder in one direction, a main unit that has one side connected to the supply hopper unit and the other side connected to a removal unit, and a rotating shaft disposed therein to mix the powder and gas.

The rotation axis may include an extension part extending from one side of the main part to the other side, and a mixed axis part connected to the extension part and disposed along an inner wall of the main part.

The mixing shaft portion may be connected to the extension portion so as to be able to rotate.

Blades may be disposed along the longitudinal direction of the mixing shaft portion.

The diameter of the main part decreases toward one side, and the rotating body may be arranged to move along the inner wall of the main part.

An emission line for discharging gas may be formed on one side of the main part.

An internal gas control method for supplying a gas from which impurities have been removed to a 3D printer according to an embodiment includes a first supply step of supplying gas to a removal unit where a remover is located, and removing impurities by heating the removal unit to a set temperature. It may include a removal step and a second supply step of supplying the gas from which impurities have been removed in the removal unit to the printing unit.

The set temperature may range from 200 degrees to 1200 degrees.

The set temperature may range from 500 degrees to 1000 degrees.

Before the removal step, a pretreatment step of removing impurities using a filter unit that removes impurities from the gas may be included.

The filter unit may remove moisture or carbon dioxide in the gas.

Before the second supply step, a powder pretreatment step may be included in which the gas and powder are mixed using a mixing unit for mixing the gas and powder and then supplied to the printing unit.

The mixing unit may include a supply hopper unit that supplies powder in one direction, a main unit that has one side connected to the supply hopper unit and the other side connected to a removal unit, and a rotating shaft disposed therein, to mix the powder and gas.

The rotation axis is disposed along the inner wall of the main part, and can mix the gas and powder by rotating and revolving around.

In the powder pretreatment step, the main part may be heated to a set temperature.

A 3D printer according to one embodiment includes a gas supply unit that supplies gas, a chamber that receives the gas, a laser output unit disposed on an upper side of the chamber, a bed disposed below the laser output portion where powder is located, and the gas. It may include a removal body located between the supply unit and the chamber to remove impurities, and a removal unit for removing impurities contained in the gas by applying a set temperature to the removal body.

The set temperature may range from 200 degrees to 1200 degrees.

The set temperature may range from 500 degrees to 1000 degrees.

In the impurity removal device of the present invention according to one embodiment, a small amount of oxygen is removed by the removal unit before gas is supplied to the printing unit, so defective products may not be printed.

In addition, the impurity removal device of the present invention according to one embodiment includes a filter unit to remove impurities in the gas, thereby preventing defective products from being printed.

In addition, the impurity removal device of the present invention according to one embodiment includes a mixing section, and supplies a mixture of powder and gas, so that the powder can be homogenized and dried, and impurities in the form of moisture and other organic substances can be removed, thereby preventing defective products. Printing may not occur.

In addition, the internal gas control method of the present invention according to one embodiment supplies gas using the above-described impurity removal device, thereby supplying gas from which impurities have been removed, so defective products may not be printed.

1 is a schematic diagram of an impurity removal device according to an embodiment.

Figure 2 shows a 3D printer including an impurity removal device according to an embodiment.

Figure 3 is a schematic diagram showing an impurity removal device according to another embodiment.

Figure 4 shows a specific example of a filter unit of an impurity removal device according to another embodiment.

Figure 5 shows a 3D printer including an impurity removal device according to another embodiment.

Figures 6a, 6b, and 6c show a filter unit of a foreign matter removal device according to an additional embodiment.

Figure 7 shows a removal portion of an impurity removal device according to an embodiment.

Figure 8 shows a removal unit of an impurity removal device according to a specific embodiment.

Figure 9 shows a removal unit of an impurity removal device according to another specific embodiment.

Figure 10 shows a modified example of the removal unit according to one embodiment.

Figure 11 shows another modified example of the removal unit according to one embodiment.

Figure 12 shows another modified example of the removal unit according to one embodiment.

Figure 13 shows an impurity removal device according to another embodiment.

Figure 14 specifically shows the mixing section of an impurity removal device according to another embodiment.

Figure 15 is a block diagram of an internal gas control method using an impurity removal device according to an embodiment.

Hereinafter, an embodiment of the present invention will be described in detail through exemplary drawings. However, this is not intended to limit the scope of the present invention.

When adding reference numerals to components in each drawing, it should be noted that identical components are given the same reference numerals as much as possible even if they are shown in different drawings. Additionally, in describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description will be omitted.

Additionally, the size or shape of components shown in the drawings may be exaggerated for clarity and convenience of explanation. In addition, terms specifically defined in consideration of the configuration and operation of the present invention are only for describing embodiments of the present invention and do not limit the scope of the present invention.

The impurity removal device of one embodiment removes and supplies impurities (gases other than inert gases or similar types of substances), and thus can eliminate defects caused by impurities during printing.

Looking at an impurity removal device according to an embodiment with reference to FIG. 1, the impurity removal device may include a gas supply unit 10, a recycling unit 30, and a removal unit 100. Here, the impurity removal device of the present invention is for a 3D printer. Therefore, the printing unit 20 may not be included. However, in Figure 1, for clarity of explanation, each component of the 3D printer will be described as the printing unit 20.

The gas supply unit 10 is a space where inert gas (argon, nitrogen, etc. - hereinafter referred to as 'gas') is stored. The inert gas stored in the gas supply unit 10 may be supplied to the printing unit 20.

The printing unit (20 - a simplified representation of the 3D printer in FIG. 2) is where various devices for 3D printing are arranged, for example, a chamber (21 - see FIG. 2), a laser output unit (22 - see FIG. 2), It may refer to the whole in which various components consisting of a bed (23 - see FIG. 2), a blade (24 - see FIG. 2), etc. are arranged.

That is, within the chamber (21 - see FIG. 2), the bed (23 - see FIG. 2) is located on the lower side and the laser output unit (22 - see FIG. 2) is located on the upper side to extract the powder located in the bed (23 - see FIG. 2). After sintering, when the bed (23 - see FIG. 2) moves downward by the cylinder, the blade (24 - see FIG. 2) supplies powder to the bed (23 - see FIG. 2), etc. can be repeatedly performed. . The printing unit 20 (a simplified representation of the 3D printer in FIG. 2) receives gas from the gas supply unit 10 and can maintain the internal atmosphere filled with inert gas.

The recycling unit 30 receives gas from the printing unit (20 - a simplified representation of the 3D printer in FIG. 2) and circulates it.

Meanwhile, a removal unit 100 is located between the gas supply unit 10 and the printing unit 20 (a simplified representation of the 3D printer in FIG. 2), so that gas from which impurities have been removed can be supplied to the gas supply unit 10. . That is, the removal unit 100 can remove trace amounts of impurities contained in the gas.

The 3D printer including the gas impurity removal device of the present invention according to the above-described embodiment can perform a printing operation after receiving gas from which impurities have been removed by the removal unit 100.

The 3D printer of one embodiment may include a chamber 21, a laser output unit 22 located within the chamber, a bed 23, and a blade 24. The chamber 21 serves to block the inside and the outside. One side of the chamber 21 may be connected to the removal unit 100 and the other side may be connected to the recycling unit 30. Here, the chamber 21 may be connected to the removal unit 100 and the recycling unit 30 by a valve. Therefore, the 3D printer of the present invention can remove impurities from the internal gas.

The laser output unit 22 is located at the top of the chamber and can output laser in a set direction. The laser output unit 22 can directly irradiate laser, but can also apply laser through a dynamic mirror so that the laser is irradiated in a desired direction due to reflection of the mirror.

The bed 23 may be located below the laser output unit 22 in the chamber 21. Powder that is the subject of printing may be placed in the bed 23. Therefore, the powder in the bed 23 can be plastically deformed by the laser output unit 22 and formed into a set shape. The bed 23 may be movable up and down. Therefore, powder can be placed in the bed 23. The blade 24 moves flat on the upper side of the bed 23 and serves to supply powder to the bed. That is, after the powder in the bed 23 is plastically deformed by the laser output unit, when the bed 23 descends, the blade 24 operates to supply the powder in the bed 23.

Meanwhile, the above operation can be performed in a chamber filled with gas from which impurities have been removed by the removal unit 100.

Additionally, the 3D printer in one embodiment may be equipped with an oxygen sensor 25. The oxygen sensor 25 can sense the oxygen concentration of the gas in the chamber. When the oxygen concentration in the chamber 21 of the 3D printer exceeds a set concentration, the recycling unit 30 may be operated.

That is, when the oxygen concentration in the chamber 21 of the 3D printer is high, the operation of the laser output unit 22, bed 23, and blade 24 is stopped, and the removal unit 100 and recycling unit 30 ) The valve is operated so that the gas in the chamber 21 can be exchanged. Here, the recycling unit 30 may supply the air in the chamber 21 back to the removal unit 100 to remove impurities in the gas.

FIG. 3 is a schematic diagram showing an impurity removal device according to another embodiment, FIG. 4 shows a specific example of a filter unit of the impurity removal device according to another embodiment, and FIG. 5 is a schematic diagram showing an impurity removal device according to another embodiment. It shows a 3D printer including:

Additionally, the present invention may additionally include a filter unit 150. As can be seen with reference to FIG. 3, the filter unit 150 can remove impurities contained in the gas 01 from the gas supply unit 10 before it is moved to the removal unit 100. Here, the filter unit 150 can remove moisture or carbon dioxide in the gas.

Looking at the filter unit 150 in more detail with reference to FIG. 4, the filter unit 150 may include silica gel 151, ascarite 152, and magnesium perchlorate 153. That is, the filter unit 150 may include at least one of silica gel 151, ascarite 152, and magnesium perchlorate 153.

That is, the filter unit 150 may be composed of only silica gel 151, or may be composed of silica gel 151 and ascarite 152. In addition, when each component of the filter unit 150 is present as one, they can be mixed together and placed in one location or in mutually partitioned spaces, with only the flow paths connected to each other.

In this way, the filter unit 150 primarily serves to remove impurities before the gas is supplied to the removal unit 100.

However, the specific type of the filter unit 150 may not be a problem as long as it can remove foreign substances (moisture, carbon dioxide, etc.) other than oxygen.

Looking at Figure 5, the 3D printer of one embodiment additionally includes a filter unit 150, so that impurities such as moisture and carbon dioxide in addition to oxygen can be removed. Therefore, more precise printing operations may be possible.

The filter unit 150 may be configured in various ways as shown in FIG. 6A. That is, the filter unit 150 may be composed of a first filter unit 150a, a second filter unit 150b, and a third filter unit 150c. These may be arranged in parallel with each other as can be seen in FIG. 6A, or as can be seen in FIG. 6B, the first filter unit 150a and the second filter unit 150b are in series, and the third filter unit 150c ) can be connected in parallel with these.

Otherwise, as shown in FIG. 6C, the first filter unit 150a, the second filter unit 150b, and the third filter unit 150c may be connected to channels that bypass each other so that the channels are opened and closed by valves. , a foreign matter sensor may be disposed between the first filter unit 150a, the second filter unit 150b, the third filter unit 150c, and the removal unit 100. Therefore, when a foreign substance is measured, each valve can be operated to open the bypassed passage.

For example, if the gas passes through the first filter unit (150a), but the gas contains more than a set amount of foreign matter, the valve is operated to block the flow path between the first filter unit (150a) and the removal unit (100), The flow path between the first filter unit 150a and the second filter unit 150b may be opened. Gas passes through the second filter unit 150b and foreign substances can be removed. Here, if there is a foreign substance in the gas that has passed through the second filter unit 150b, the flow path between the second filter unit 150b and the removal unit 100 is closed as described above, and the second filter unit 150b The flow path between and the third filter unit 150c may be opened.

Meanwhile, the 3D printer including the impurity removal device including the filter units 150 shown in FIGS. 6A, 6B, and 6C is similar to the one described above, and will not be described here through separate drawings.

FIG. 7 illustrates a removal portion of an impurity removal device according to an embodiment, FIG. 8 illustrates a removal portion of an impurity removal device according to a specific embodiment, and FIG. 9 illustrates an impurity removal device according to another specific embodiment. This shows the removal part.

Looking at the removal unit 100 of one embodiment with reference to FIG. 7, the removal unit 100 may remove impurities in the gas by allowing the gas to pass through the removal body 110. Here, the removal unit 100 can remove impurities in the gas by placing the removal body 110 and the gas and then heating it.

Meanwhile, the removal unit 100 of one embodiment may include an oxygen sensor 25 capable of measuring oxygen concentration, and may have a bypass passage connected to a location before passing through the removal unit. Therefore, when the gas that has passed through the removal unit contains more than a set amount of oxygen, a valve (not shown) is operated to open the bypass passage, and the passage connected to the removal unit 100 is closed to allow the gas to return to its original position. It can be allowed to pass through the removal unit 100 again.

The removal body 110 of the removal unit 100 of one embodiment may include any one pure metal among titanium, magnesium, aluminum, and calcium. At this time, the removal unit 100 may be heated to a set temperature, and the set temperature may be in the range of 200 degrees to 1200 degrees. Hereinafter, various embodiments of the removal body 110 will be described.

Looking at the removal unit 100 of an embodiment through FIG. 8, the removal body 110 is exemplarily made of titanium wire (Ti wire), magnesium wire (Mg wire), aluminum wire (Al wire), and calcium wire (Ca wire). ) may be any one of the following. That is, any one of titanium wire, magnesium wire, aluminum wire, and calcium wire may be disposed in the passage through which gas can move within the removal unit 100. And the removal unit 100 can be heated to a set temperature. The temperature set here may range from 200 degrees to 1200 degrees. More specifically, the titanium wire may range from 700 degrees to 1200 degrees, the magnesium wire and aluminum wire may range from 400 degrees to 600 degrees, and the calcium wire may range from 200 degrees to 400 degrees. For example, for magnesium wire, the preferred temperature setting may be 500 degrees.

That is, for example, in the case where the removal member 110 is a magnesium wire, the inside of the removal unit 100 is maintained at at least 500 degrees, and the magnesium wire may be positioned inside the removal unit 100. Therefore, the gas passes through a magnesium wire heated to a set temperature and oxygen in the gas can be removed.

As another example, the removal body 110 may be in a bulk form rather than a wire form. In the case of bulk, it can be heated to the same temperature range as in the case of the wire described above.

Looking at the removal unit 100 of one embodiment with reference to FIG. 9, the removal body 110 may be made of sponge titanium (Sponge Ti). That is, the sponge titanium may be disposed in a passage through which gas can move within the removal unit 100. And the removal unit 100 can be heated to a set temperature. The temperature set here may range from 700 degrees to 1200 degrees. A preferably set temperature may be 900 degrees.

That is, the inside of the removal unit 100 is maintained at at least 900 degrees, and the sponge titanium can be placed inside it. Therefore, the gas passes through a titanium sponge heated to a set temperature and the oxygen in the gas can be removed.

As another example, the removal body 110 of the removal unit 100 may include an alloy containing at least one of magnesium, aluminum, calcium, iron, and silicon. At this time, the removal unit 100 may be heated to a set temperature, and the set temperature may be in the range of 500 degrees to 1000 degrees. Hereinafter, various types of alloys will be described by way of example.

The removal body 110 may be an alloy containing aluminum-calcium-iron (wire or bulk, respectively). The content (by weight) may be aluminum (35-45%), calcium (25-40%), and iron (25-35%). The set temperature may range from 500 degrees to 900 degrees.

The removal body 100 may be an alloy containing magnesium-silicon-iron (wire or bulk, respectively). The content may be magnesium (30-80%), silicon (10%), and iron (Balance). The set temperature may range from 500 degrees to 900 degrees.

The removal body 100 may be an alloy containing calcium-silicon (wire or bulk, respectively). The content may be calcium (20-40%) and silicon (50-70%). The set temperature may range from 600 degrees to 1000 degrees.

Figure 10 shows a modified example of the removal unit according to an embodiment, Figure 11 shows another modified example of the removal unit according to an embodiment, and Figure 12 shows another modification of the removal unit according to an embodiment. A modified example is shown.

Looking at the removal unit 100 according to another embodiment with reference to FIG. 10, the removal unit 100 may be composed of a first removal unit 101 and a second removal unit 102.

The first removal unit 101 and the second removal unit 102 may be provided with a first removal body 111 and a second removal body 112, respectively.

Here, the first removal body 111 may be a magnesium wire (Mg wire). The second removal body 112 may be sponge titanium (sponge Ti). However, this is an example, and the first removal body 111 and the second removal body 112 may each include any one pure metal among titanium, magnesium, aluminum, and calcium. Alternatively, the first removal body 111 and the second removal body 112 may each include an alloy containing at least one of magnesium, aluminum, calcium, iron, and silicon. Hereinafter, the case where the first removal body 111 is a magnesium wire (Mg wire) and the second removal body 112 is a sponge titanium (sponge Ti) will be described as an example.

The first removal unit 101 may be heated to a first temperature, and the second removal unit 102 may be heated to a second temperature.

Here, the first temperature may be in the range of 400 degrees to 600 degrees, and preferably 500 degrees. The second temperature may range from 700 degrees to 1200 degrees, and is preferably 900 degrees.

Therefore, impurities can be removed from the gas while moving through the first removal unit 101 and the second removal unit 102. However, here, it is preferable that the gas passes through the first removal unit 101 and the second removal unit 102. The reason is that the set temperature of the first removal unit 101 is lower than the set temperature of the second removal unit 102. Therefore, since the temperature of the gas passing through the second removal unit 102 is higher than the temperature within the first removal unit 101, it is preferable that the gas is designed to pass through the first removal unit 101 first.

Looking at another modified example through FIG. 11, the removal unit 100 may include a first removal unit 101 and a second removal unit 102 connected in parallel. That is, the gas can be supplied to the first removal unit 101 and the second removal unit 102, and the gas can be supplied to a place where the flow path is opened and closed by the valve.

Looking at another modified example through FIG. 12, the removal unit 100 is composed of a first removal unit 101 and a second removal unit 102, which are connected in parallel and include a flow path branched by a valve. can do.

Additionally, an oxygen sensor 25 may be disposed between each of the

removal units

101 and 102 and the printing unit 20 (see FIG. 1). For example, the gas passes through the first removal unit 101 to remove impurities, but when the oxygen sensor detects that it contains more than a set amount of oxygen, the valve is operated to open the flow path between the printing unit 20 (see FIG. 1). may be closed, and the flow path between the first removal unit 101 and the second removal unit 102 may be opened. Therefore, foreign substances can be removed from the gas again by the second removal unit 102.

Figure 13 shows an impurity removal device according to another embodiment.

The impurity removal device according to one embodiment may further include a mixing unit 200.

The mixing unit 200 may store powder and supply the powder to the printing unit 20. Here, the mixing unit 200 is connected to the removal unit 100, so the powder and gas can be mixed and then supplied. Therefore, the mixing unit 200 can maintain the inside of the printing unit 20 in a gaseous atmosphere from which impurities have been removed, and can supply the powder into the printing unit 20 after removing impurities (moisture, organic substances, etc.) in the powder.

Looking at the mixing unit 200 through FIG. 14, the mixing unit 200 includes a supply hopper unit 210 and a main unit 240.

The supply hopper unit 210 stores powder and may be connected to the main unit 240 at the upper side of the main unit 240. Therefore, the powder stored in the supply hopper unit 210 can be supplied to the main unit 240. Here, a supply valve 220 may be disposed between the supply hopper part 210 and the main part 240.

The supply valve 220 may open or close the flow path between the supply hopper unit 210 and the main unit 240 depending on the power supply. Therefore, a set amount of powder can be stored in the main unit 240.

As described above, the main part 240 is located above the supply hopper part 210, and the connection part 230 may be formed in a position that does not interfere with the connection with the supply hopper part 210. Here, the connection part 230 may be located on one side of the supply valve 220. The connection part 230 may be connected to the removal part 100. Therefore, when the supply valve 220 opens the flow path, gas along with the powder can be supplied to the main part 240.

However, although the main part 240 in FIG. 14 is formed in a cone shape, it will be obvious that it is not limited to this shape.

The main part 240 may have a rotation axis 245 disposed therein. The rotating shaft 245 can stir the powder so that the powder and gas are mixed. The rotation shaft 245 may be composed of an extension portion 245-1 and a mixed shaft portion 245-2. The extension part 245-1 may extend radially from the center of the main part 240. The mixing shaft portion 245-2 may extend from an end of the extension portion 245-1 along the inner wall of the main portion 240 in a direction intersecting the extension portion 245-1.

The extension part 245-1 is rotatably connected to the main part 240 around the center of the main part 240, and the mixed shaft part 245-2 is rotatable to the extension part 245-1. is formed Therefore, the mixed shaft portion 245-2 is formed to be capable of rotation and revolution. Therefore, the mixing shaft portion 245-2 can smoothly mix powder and gas.

Here, blades 245-3 may be disposed along the longitudinal direction of the mixing shaft portion 245-2. Therefore, when the mixing shaft portion 245-2 rotates, the powder can be more easily stirred due to the blade 245-3, and the powder and gas can be mixed.

Meanwhile, a heating unit 250 may be disposed outside the main unit 240. When power is supplied, the heating unit 250 can apply heat to the main unit 240 to maintain the temperature inside the main unit 240 at a set temperature. The temperature set here may be 50 degrees or more and 300 degrees or less. The temperature set here is preferably maintained around 100 to 200 degrees.

A discharge valve 260 may be connected to the lower side of the main part 240. The discharge valve 260 serves to open or close the flow path depending on the power supply. Therefore, the powder mixed with gas in the main unit 240 can be supplied to the printing unit 20.

Additionally, the main part 240 may have a discharge line 270 formed therein to control pressure. The discharge line 270 opens and closes the flow path according to the power supply, and only gas can be discharged to the outside from the main part 240.

The internal gas control method according to one embodiment supplies gas from which impurities have been removed using the impurity supply device described above.

The internal gas control method according to one embodiment may include a first supply step (S10), a pretreatment step (S20), a removal step (S30), and a second supply step (S40). Additionally, one embodiment may further include a powder pretreatment step (S35).

The first supply step (S10) is a step of supplying gas from the gas supply unit 10 to the removal unit 100 where the removal body 110 is located.

The pretreatment step (S20) refers to a step of initially removing impurities by supplying gas to the filter unit 150 before supplying gas to the removal unit 100. The filter unit 150 is as described above in FIG. 2. Therefore, the filter unit 150 may include at least one of silica gel 151, magnesium perchlorate 153, or ascarite 152 (Ascarite).

Therefore, impurities such as moisture or carbon dioxide can be removed from the gas before it is supplied to the removal unit 100.

The removal step (S30) is a step of removing impurities in the gas using the removal unit 100.

Here, the removal unit 100 is as described above. Therefore, the removal unit 100 includes a removal body 110 (where the removal body may include any one pure metal of titanium, magnesium, aluminum, and calcium, or the removal body may include at least one of magnesium, aluminum, calcium, iron, and silicon). (which may include an alloy containing either one) is disposed and heated to a set temperature (200 to 1200 degrees for a pure metal, or 500 to 1000 degrees for an alloy). Illustratively, when the removal body is at least one of magnesium wire or titanium sponge, the removal unit 100 may be heated to 400 degrees to 600 degrees or 700 degrees to 1200 degrees, and preferably, the removal unit 100 is heated to The temperature may be 500 degrees or 900 degrees respectively.

That is, the gas moves through the heated removal body 110 and impurities in the gas can be removed.

The second supply step (S40) is a step of supplying gas from which impurities have been removed to the printing unit 20. Here, the printing unit 20 can manage the arrangement of various components within the chamber, as described with reference to FIG. 1 .

In this way, the present invention can prevent printing of defective products by maintaining the printing unit 20 in an inert gas atmosphere.

Meanwhile, the powder pretreatment step (S35) is a step in which the gas from which impurities have been removed in the removal unit 100 is moved to the mixing unit 200, mixed with powder, and supplied to the printing unit 20. Here, the mixing unit 200 is as described above. That is, the mixing section 200 includes a supply hopper section 210 and a main section 240, and a supply valve 220 is disposed between the main section 240 and the supply hopper section 210, and the supply valve ( A connection part 230 is disposed in 220, and the discharge valve 260 may also be connected to the main part 240.

Here, a rotating shaft 245 is disposed inside the main portion 240, and the rotating shaft 245 may include a mixed shaft portion 245-2 in which an extension portion 245-1 and a blade 245-3 are formed. . Therefore, the mixing shaft portion 245-2 can mix gas and powder while rotating and revolving.

Meanwhile, the heating unit 250 is disposed on the outside of the main part 240 so that the inside of the main part 240 can be maintained at a temperature ranging from 50 degrees to 300 degrees, preferably in the range of 100 degrees to 200 degrees.

Although the present invention has been shown and described in relation to specific embodiments, it is known in the art that various improvements and changes can be made to the present invention without departing from the technical spirit of the present invention as provided by the following claims. This will be self-evident to those with ordinary knowledge.

(Explanation of symbols)

10: Gas supply unit

20: Printing department

21: chamber

22: Laser output unit

23: Bed

24: blade

25: Oxygen sensor

30: recycling unit

100: removal part

101: first removal section

102: second removal unit

110: removal body

111: first removal body

112: Second removal body

150: filter part

151: Silica gel

152: Ascarite

153: Magnesium perchlorate

200: mixing section

210: Supply hopper part

220: Supply valve

230: connection part

240: main part

245: rotation axis

245-1: Extension part

245-2: Mixed shaft section

245-3: Blade

250: heating unit

260: discharge valve

270: discharge line

Claims

In the impurity removal device for a 3D printer,

A gas supply unit that supplies gas; and

A removal unit that receives the gas from the gas supply unit and includes a removal body that removes impurities, and removes impurities contained in the gas by applying a set temperature to the removal body.

An impurity removal device comprising:
According to paragraph 1,

An impurity removal device wherein the remover contains any one pure metal of titanium, magnesium, aluminum, and calcium.
According to paragraph 2,

The set temperature is an impurity removal device in the range of 200 degrees to 1200 degrees.
According to paragraph 1,

The impurity removal device includes an alloy containing at least one of magnesium, aluminum, calcium, iron, and silicon.
According to paragraph 4,

The set temperature is an impurity removal device in the range of 500 degrees to 1000 degrees.
According to paragraph 1,

An impurity removal device in which a filter for removing impurities is disposed between the gas supply unit and the removal unit.
According to clause 6,

The filter part

An impurity removal device consisting of a plurality of filter units, each of which includes a flow path connected to each other.
According to clause 6,

The filter unit is an impurity removal device capable of removing moisture or carbon dioxide when the gas penetrates.
In paragraph 1

An impurity removal device further comprising a mixing section for mixing powder and gas.
In paragraph 9

The mixing part

An impurity removal device comprising a supply hopper unit that supplies powder in one direction, a main unit that has one side connected to the supply hopper unit and the other side connected to the removal unit and a rotating shaft disposed therein to mix the powder and gas.
According to clause 10,

The rotation axis is

An impurity removal device comprising an extension part extending from one side of the main part to the other side and a mixing shaft part connected to the extension part and disposed along an inner wall of the main part.
According to clause 11,

An impurity removal device in which the mixing shaft portion is connected to the extension portion so as to be able to rotate.
According to clause 11,

An impurity removal device in which blades are disposed along the longitudinal direction of the mixing shaft.
According to clause 10,

An impurity removal device in which the diameter of the main part becomes smaller toward one side, and the rotation axis is arranged to move along the inner wall of the main part.
According to clause 10,

An impurity removal device in which a discharge line for releasing gas is formed on one side of the main portion.
In the internal gas control method of supplying gas from which impurities have been removed to a 3D printer

A first supply step of supplying gas to the removal unit where the removal body is located;

A removal step of removing impurities by heating the removal unit to a set temperature; and

An internal gas control method comprising a second supply step of supplying the gas from which impurities have been removed in the removal unit to the printing unit.
According to clause 16,

The remover contains any one pure metal of titanium, magnesium, aluminum, and calcium,

The set temperature is in the range of 200 degrees to 1200 degrees.
According to clause 16,

The removal body includes an alloy containing at least one of magnesium, aluminum, calcium, iron, and silicon,

An internal gas control method wherein the set temperature is in the range of 500 to 1000 degrees.
According to clause 16,

Before the removal step

An internal gas control method comprising a pretreatment step of removing impurities from the gas using a filter unit that removes impurities from the gas.
According to clause 19,

An internal gas control method in which the filter unit can remove moisture or carbon dioxide in the gas.
According to clause 16,

Before the second supply stage

An internal gas control method comprising a powder pretreatment step of mixing gas and powder using a mixing unit for mixing the gas and powder and supplying the mixture to the printing unit.
According to clause 21,

The mixing part

An internal gas control method comprising a supply hopper part that supplies powder in one direction, a main part that has one side connected to the supply hopper part and the other side connected to the removal part, and a rotating shaft disposed therein, to mix the powder and gas.
According to clause 22,

The rotation axis is disposed along the inner wall of the main part, and rotates and rotates to mix the gas and powder.
According to clause 21,

In the powder pretreatment step

An internal gas control method in which the main part is heated to a set temperature.
A gas supply unit that supplies gas;

a chamber supplied with the gas;

a laser output unit disposed on the upper side of the chamber;

a bed disposed below the laser output unit where powder is located; and

It includes a removal body located between the gas supply unit and the chamber to remove impurities, and a removal unit removing impurities contained in the gas by applying a set temperature to the removal body.

A 3D printer including.
According to clause 25,

The remover contains any one pure metal of titanium, magnesium, aluminum, and calcium,

A 3D printer where the set temperature is in the range of 200 degrees to 1200 degrees.
According to clause 25,

The removal body includes an alloy containing at least one of magnesium, aluminum, calcium, iron, and silicon,

A 3D printer where the set temperature is in the range of 500 to 1000 degrees.