JP5764751B2 - Manufacturing method and manufacturing apparatus for three-dimensional shaped object - Google Patents

Description

  The present invention relates to a method for manufacturing a three-dimensional shaped object and a manufacturing apparatus therefor. More specifically, the present invention manufactures a three-dimensional shaped object in which a plurality of solidified layers are laminated and integrated by repeatedly performing formation of a solidified layer by irradiating a predetermined portion of the powder layer with a light beam. The present invention relates to a method and an apparatus therefor.

  Conventionally, a method of manufacturing a three-dimensional shaped object by irradiating a material powder with a light beam (generally referred to as “powder sintering lamination method”) is known. In such a method, “(i) by irradiating a predetermined portion of the powder layer with a light beam, the powder at the predetermined portion is sintered or melt-solidified to form a solidified layer, and (ii) of the obtained solidified layer A three-dimensional shaped article is manufactured by repeating the process of “laying a new powder layer on the top and irradiating the same with a light beam to form a solidified layer” (see Patent Document 1 or Patent Document 2). When inorganic material powder such as metal powder or ceramic powder is used as material powder, the obtained three-dimensional shaped object can be used as a mold, and organic material powder such as resin powder or plastic powder can be used. In such a case, the obtained three-dimensional shaped object can be used as a model. According to such a manufacturing technique, it is possible to manufacture a complicated three-dimensional shaped object in a short time.

  Taking a case where a metal powder is used as a material powder and the obtained three-dimensional shaped object is used as a mold, as shown in FIG. 1, first, a powder layer 22 having a predetermined thickness t1 is formed on a substrate 21 as shown in FIG. After that (see FIG. 1A), a light beam is irradiated onto a predetermined portion of the powder layer 22 to form a solidified layer 24 on the modeling plate 21. Then, a new powder layer 22 is laid on the formed solidified layer 24 and irradiated again with a light beam to form a new solidified layer. When the solidified layer is repeatedly formed in this way, a three-dimensional shaped object in which a plurality of solidified layers 24 are laminated and integrated can be obtained (see FIG. 1B).

JP-T-1-502890 JP 2000-73108 A

  In many cases, the three-dimensional shaped object is manufactured in a chamber maintained in a predetermined inert atmosphere in order to prevent oxidation of the formed object. In the chamber, there are “means for forming a powder layer”, “a modeling table on which a powder layer and / or a solidified layer is to be formed” and the like, while a light beam irradiation means is provided outside the chamber. ing. The light beam emitted from the light beam irradiation means is irradiated to a predetermined portion of the powder layer through the light transmission window of the chamber. For example, as can be seen with reference to FIGS. 2A and 2B, the chamber 50 is provided with a light transmission window 52, and the light beam L enters the chamber 50 through the light transmission window 52. .

  Here, when the powder layer is irradiated with a light beam to sinter or melt and solidify the powder, as shown in FIGS. 2A and 2B, a smoke-like substance called “fume” 8 (for example, a metal) Vapor or resin vapor) is generated from the beam irradiation site. Since this fume rises and adheres to or burns into the light transmission window of the chamber (see FIG. 3), the light transmission window becomes cloudy and the light beam transmittance, refractive index, and the like can be lowered. When the transmittance or refractive index of the light beam is lowered, a desired solidified layer cannot be obtained, and the manufacture of the originally shaped object is hindered. In particular, when a metal powder layer is used as the powder layer, the strength of the three-dimensional shaped object decreases due to reasons such as “sintering is not stable” or “sintering density cannot be increased”. Is concerned.

  Also, the fumes can directly affect the light beam incident in the chamber. Specifically, the generated fumes can rise, but the rising fumes may block the path of the light beam, and the amount of irradiation of the light beam (the amount irradiated to the powder layer) can be reduced. That is, there is a concern that the amount of energy of the light beam provided to the powder layer may be lower than a predetermined value due to the blockage of the fume.

  The present invention has been made in view of such circumstances. That is, an object of the present invention is to provide a powder sintering lamination method in which the influence of generated fumes is suppressed as much as possible.

In order to solve the above problems, in the present invention,
(I) a step of irradiating a predetermined portion of the powder layer with a light beam to sinter or melt-solidify the powder at the predetermined portion to form a solidified layer; and (ii) a new powder on the obtained solidified layer A method for producing a three-dimensional shaped object, wherein a step of forming a layer and irradiating a predetermined portion of the new powder layer with a light beam to form a further solidified layer is repeated in the chamber,
A three-dimensional shape molding characterized by providing a cylindrical member surrounding a lower space region of a light transmission window provided in a chamber, and supplying a gas of a temperature or type different from the atmosphere in the chamber into the cylindrical member A method of manufacturing an article is provided.

  In a preferred embodiment, a gas having a temperature or type different from that in the chamber atmosphere is supplied to the inside of the cylindrical member as a gas having a temperature or type different from that in the chamber atmosphere, and the low-temperature gas and the chamber atmosphere are mixed. The “cold gas” is moved downward by natural convection due to the temperature difference.

  In a preferred aspect, a gas that is lighter than the gas in the chamber atmosphere is charged into the cylindrical member as “a gas having a temperature or type different from that in the chamber atmosphere”, and the light gas is allowed to exist in the cylindrical member. A solidified layer is formed in the state. Argon or helium is preferably used as the “light gas” charged into the cylindrical member. In such an embodiment, it is also preferable to use a gas having a temperature higher than the temperature of the atmospheric gas in the chamber as the “light gas”.

  In a preferred aspect, an annular gas flow is additionally formed by flowing a gas from the lower end of the cylindrical member. An annular gas supply member may be used to form the annular gas flow. For example, the annular gas flow may be formed by providing an annular gas supply member at the lower end of the cylindrical member and supplying gas downward from the annular gas supply member. Alternatively, a fan may be used to form the annular gas flow. For example, the annular gas flow may be formed by driving a fan provided inside the chamber. Such an annular gas flow may be formed only during irradiation with a light beam.

In this invention, the "manufacturing apparatus of a three-dimensional shape molded article" for implementing the manufacturing method mentioned above is also provided. The manufacturing apparatus of such a three-dimensional shaped object is
Powder layer forming means for forming a powder layer,
A light beam irradiation means for irradiating the powder layer with a light beam so as to form a solidified layer;
A molding table on which a powder layer and / or a solidified layer is to be formed; and a chamber having a powder layer forming means and a molding table therein,
It further includes a cylindrical member surrounding a lower space region of the light transmission window provided in the chamber, and means for supplying a gas having a temperature or type different from the atmosphere in the chamber into the cylindrical member.

  In the present invention, the fumes generated by the light beam irradiation can be moved away from the light transmission window of the chamber. In particular, the rising fumes can be moved radially outwards by being pressed by “gas inside the cylinder member” and / or “annular gas flow”. Thereby, “fogging” of the chamber light transmission window can be prevented, and “blocking of the light beam path by fumes” can also be prevented.

  That is, in the present invention, it is possible to prevent a decrease in the transmittance of the light beam incident into the chamber and a change in the refractive index, thereby achieving a desired solidified layer formation. More specifically, when the powder layer is a metal powder layer and the solidified layer is a sintered layer, the inconvenience that “sintering is not stable or the density of the sintered portion cannot be increased”. Can be avoided, and the strength of the three-dimensional shaped object can be kept substantially uniform.

Sectional view schematically showing the operation of the stereolithography combined processing machine FIG. 2A is a perspective view schematically illustrating a mode in which fumes are generated in the chamber by irradiation with a light beam (FIG. 2A: a composite apparatus having a cutting mechanism, FIG. 2B: an apparatus having no cutting mechanism). Sectional view schematically showing the flow of fume in the chamber The perspective view which showed typically the aspect by which the powder sintering lamination method is performed The perspective view which showed typically the structure of the optical shaping complex processing machine by which a powder sintering lamination method is implemented Flow chart of operation of stereolithography combined processing machine Schematic representation of the optical modeling complex processing process over time A diagram schematically showing the concept of the present invention Sectional drawing (FIG. 9 (a)) which showed typically the aspect which supplies low temperature gas to the inside of a cylindrical member, and the perspective view of the member used for it (FIG.9 (b)) Schematic diagram for explaining “around the light transmission window” (FIG. 10A: when the horizontal cross section is a circular light transmission window, FIG. 10B: the horizontal cross section is rectangular or rectangular. If) Sectional drawing (FIG. 11 (a)) which showed the aspect which supplies light gas inside a cylindrical member typically, and the perspective view of the member used for it (FIG.11 (b)) Sectional drawing which showed typically the aspect which additionally forms the downward annular gas flow from the lower end part of a cylinder member in addition to supplying low temperature gas to the inside of a cylinder member (Fig.12 (a)) And the perspective view of the member used for it (FIG.12 (b)) Sectional drawing which showed typically the aspect which additionally forms the downward annular gas flow from the lower end part of a cylinder member in addition to supplying light gas to the inside of a cylinder member (Fig.13 (a)) FIG. 13B is a perspective view of members used for the same (FIG. 13B). FIG. 14A is a perspective view schematically showing a local discharge opening portion of the annular gas supply member, and a perspective view schematically showing a slit-like discharge opening portion of the annular gas supply member. FIG. 14 (b)) Sectional drawing which represented typically the aspect which uses a fan for formation of annular gas flow

  Hereinafter, the present invention will be described in more detail with reference to the drawings.

  In this specification, “powder layer” refers to, for example, “a metal powder layer made of metal powder” or “a resin powder layer made of resin powder”. The “predetermined portion of the powder layer” substantially means a region of the three-dimensional shaped article to be manufactured. Therefore, by irradiating the powder existing at the predetermined location with a light beam, the powder is sintered or melted and solidified to form the shape of the three-dimensional shaped object. Further, the “solidified layer” substantially means “sintered layer” when the powder layer is a metal powder layer, and substantially means “cured layer” when the powder layer is a resin powder layer. Meaning.

[Powder sintering lamination method]
First, the powder sintering lamination method as a premise of the production method of the present invention will be described. For the convenience of explanation, the powder sintering lamination method will be described on the premise that the material powder is supplied from the material powder tank and the material powder is leveled using a leveling plate to form a powder layer. Further, in the case of the powder sinter lamination method, a description will be given by taking as an example a mode of composite processing in which cutting of a molded article is also performed (that is, assuming the mode shown in FIG. 2A instead of FIG. 2B) And). 1, 4 and 5 show the function and configuration of a stereolithographic composite processing machine capable of performing the powder sintering lamination method and cutting. The optical modeling composite processing machine 1 includes “a powder layer forming means 2 for forming a powder layer by spreading a powder such as a metal powder and a resin powder with a predetermined thickness” and “in a modeling tank 29 whose outer periphery is surrounded by a wall 27. In FIG. 2, “a modeling table 20 that moves up and down”, “a modeling plate 21 that is arranged on the modeling table 20 and serves as a foundation of the modeling object”, “a light beam irradiation means 3 that irradiates a light beam L to an arbitrary position”, and “a modeling object” Cutting means 4 ”for cutting the periphery of the main body. As shown in FIG. 1, the powder layer forming means 2 includes “a powder table 25 that moves up and down in a material powder tank 28 whose outer periphery is surrounded by a wall 26” and “to form a powder layer 22 on a modeling plate”. And the leveling plate 23 ". As shown in FIGS. 4 and 5, the light beam irradiation means 3 includes a “light beam oscillator 30 that emits a light beam L” and a “galvanomirror 31 that scans (scans) the light beam L onto the powder layer 22 (scanning). Optical system) ”. If necessary, the light beam irradiation means 3 has beam shape correction means (for example, a pair of cylindrical lenses and a rotation drive mechanism for rotating the lenses around the axis of the light beam) for correcting the shape of the light beam spot. And an fθ lens. The cutting means 4 mainly includes “a milling head 40 that cuts the periphery of a modeled object” and “an XY drive mechanism 41 (41a, 41b) that moves the milling head 40 to a cutting location” (FIGS. 4 and 4). 5).

  The operation of the optical modeling complex machine 1 will be described in detail with reference to FIG. 1, FIG. 6, and FIG. FIG. 6 shows a general operation flow of the optical modeling composite processing machine, and FIG. 7 schematically shows the optical modeling composite processing process schematically.

  The operation of the optical modeling composite processing machine includes a powder layer forming step (S1) for forming the powder layer 22, a solidified layer forming step (S2) for forming the solidified layer 24 by irradiating the powder layer 22 with the light beam L, It is mainly composed of a cutting step (S3) for cutting the surface of the modeled object. In the powder layer forming step (S1), the modeling table 20 is first lowered by Δt1 (S11). Next, after raising the powder table 25 by Δt1, as shown in FIG. 1A, the leveling plate 23 is moved in the direction of arrow A, and the powder (for example, “average particle size 5 μm”) ˜iron powder of about 100 μm ”or“ powder of nylon, polypropylene, ABS, etc. having an average particle size of about 30 μm to 100 μm ”is transferred onto the modeling plate 21 (S12), and the powder layer is averaged to a predetermined thickness Δt1 22 is formed (S13). Next, the process proceeds to the solidified layer forming step (S2), and the light beam L (for example, carbon dioxide laser (about 500 W), Nd: YAG laser (about 500 W), fiber laser (about 500 W), ultraviolet light, etc.) from the light beam oscillator 30) (S21), the light beam L is scanned to an arbitrary position on the powder layer 22 by the galvanometer mirror 31 (S22), and the powder is melted and solidified to form the solidified layer 24 integrated with the modeling plate 21. (S23). The light beam is not limited to being transmitted in the air, but may be transmitted by an optical fiber or the like.

  The powder layer forming step (S1) and the solidified layer forming step (S2) are repeated until the thickness of the solidified layer 24 reaches a predetermined thickness obtained from the tool length of the milling head 40, and the solidified layer 24 is laminated (FIG. 1). (See (b)). In addition, the solidified layer newly laminated | stacked will be integrated with the solidified layer which comprises the already formed lower layer in the case of sintering or melt-solidification.

  When the thickness of the laminated solidified layer 24 reaches a predetermined thickness, the process proceeds to the cutting step (S3). In the embodiment shown in FIGS. 1 and 7, the cutting step is started by driving the milling head 40 (S31). For example, when the tool (ball end mill) of the milling head 40 has a diameter of 1 mm and an effective blade length of 3 mm, a cutting process with a depth of 3 mm can be performed. Therefore, if Δt1 is 0.05 mm, 60 solidified layers are formed. At that time, the milling head 40 is driven. The milling head 40 is moved in the directions of the arrow X and the arrow Y by the XY drive mechanism 41 (41a, 41b), and the surface of the shaped object composed of the laminated solidified layer 24 is cut (S32). And when manufacture of a three-dimensional shape molded article has not ended yet, it will return to a powder layer formation step (S1). Thereafter, the three-dimensional shaped object is manufactured by repeating S1 to S3 and laminating a further solidified layer 24 (see FIG. 7).

  The irradiation path of the light beam L in the solidified layer forming step (S2) and the cutting path in the cutting step (S3) are previously created from three-dimensional CAD data. At this time, a machining path is determined by applying contour line machining. For example, in the solidified layer forming step (S2), contour shape data of each cross section obtained by slicing STL data generated from a three-dimensional CAD model at an equal pitch (for example, 0.05 mm pitch when Δt1 is 0.05 mm) is used. .

[Production method of the present invention]
The present invention is particularly characterized in the treatment during light beam irradiation among the powder sintering lamination methods described above. Specifically, the flow of fumes generated by irradiation of the light beam is guided in a direction away from the light transmission window by “gas inside the cylindrical member” (see FIG. 8). As a result, “fogging” of the chamber light transmission window can be prevented, and “blocking of the light beam path by fumes” can be prevented.

  In the present specification, “fume” refers to a smoke-like substance generated from a powder layer and / or a solidified layer irradiated with a light beam (for example, “a metal caused by a metal powder material” in the manufacturing method of a three-dimensional shaped object. “Vapor” or “resin vapor due to resin powder material”).

  In the present invention, as shown in FIGS. 9A and 9B, a cylindrical member 80 that surrounds at least a part of the lower space region of the light transmission window 52 is used. A temperature or type of gas different from the atmosphere in the chamber is supplied into the cylindrical member 80. For example, as illustrated, a gas 90 having a temperature lower than the atmospheric temperature in the chamber is supplied. Accordingly, the low temperature gas 90 is moved downward from the inside of the cylindrical member 80 by natural convection caused by the low temperature gas. That is, a downward airflow is generated in the lower region of the light transmission window 52, thereby suppressing the rise of the fume. As a result, the pressed fumes can move outward in the horizontal direction. That is, the fumes flow away from the light transmission window and the light beam path, so that fogging of the light transmission window and attenuation of the light beam can be effectively prevented.

  In the present invention, as shown in FIG. 9B, a low temperature gas is supplied via a gas introduction line 94a provided with a temperature controller 93 and a pump (not shown) and a gas discharge part 94b communicating with the line. May be supplied to the inner space of the tubular member 80. By such supply, the inside of the cylindrical member 80 can be temporarily filled with the low temperature gas 90. The low-temperature gas 90 once filled inside the cylindrical member 80 can move downward naturally due to the temperature difference from the atmospheric gas in the chamber, so that a downdraft is generated in the lower region of the light transmission window 52. To do.

  The temperature of the low temperature gas 90 supplied to the inner space of the cylindrical member is not particularly limited as long as it is lower than the atmospheric temperature in the chamber. For example, the temperature of the low temperature gas 90 is preferably 2 ° C. to 30 ° C., more preferably 5 ° C. to 20 ° C. lower than the atmospheric temperature in the chamber (for example, room temperature 25 ° C.).

  The kind of the low temperature gas supplied to the inner space of the cylindrical member is not particularly limited, and various gases can be used. For example, a different type of gas from the atmospheric gas charged in the chamber may be used, or the same type of gas may be used. For example, “air” is preferably used from the viewpoint of cost. Moreover, it is preferable to use inert gas, such as nitrogen gas, from a viewpoint of oxidation prevention of a powder layer and a molded article.

As long as the cylindrical member 80 surrounds the lower space region of the light transmission window 52 as shown in FIGS. As shown in the figure, the cylindrical member 80 may be installed so that the upper end of the cylindrical member 80 is located at the peripheral edge of the light transmission window 52. The material of the cylindrical member 80 itself may be metal or plastic. Illustrating the dimensions of the cylindrical member 80, for example, the height dimension L and the thickness dimension W shown in FIG. 9B are as follows:

-Height dimension L : 5 to 50 mm (for example, 10 to 25 mm)

・Thickness dimension W : 1 to 50 mm (for example, 5 to 15 mm)

  The location where the upper end of the cylindrical member 80 is positioned is preferably around the light transmission window. As used herein, “around the light transmission window” refers to a local region having a horizontal separation distance (for example, “La” or “Lb” as shown in FIG. 10) within 10 cm from the peripheral edge of the light transmission window 52, It preferably refers to a local area within 5 cm. In other words, the “periphery of the light transmission window” referred to in the present invention can correspond to a shaded area having a width dimension La or Lb as shown in FIG.

  Instead of the “cold gas 90”, a gas lighter than the atmospheric gas in the chamber may be supplied into the cylindrical member 80. For example, as shown in FIG. 11, the light gas 96 may be charged into the cylindrical member 80, and thereby the solidified layer may be formed in a state where the light gas 96 is present inside the cylindrical member 80. In such a case, a light gas 96 sealing layer can be formed below the light transmission window 52, thereby preventing fume from rising. Since the blocked fume can move outward in the horizontal direction, fogging of the light transmission window and attenuation of the light beam can be prevented. That is, if the light gas 96 is charged inside the cylindrical member 80, fumes flow away from the light transmission window and the light beam path, and fogging of the light transmission window and attenuation of the light beam can be prevented.

  As shown in FIG. 11 (b), the light gas 96 is cylinderized via a gas introduction line 98a provided with a temperature controller 97 and a pump (not shown) and a gas discharge part 98b connected to the line. You may supply to the inner space of the member 80. FIG. By such supply, the light gas 96 can be filled inside the cylindrical member 80. The light gas 96 has a tendency to hardly move downward due to its specific gravity, so that the light gas 96 stays in the inner space of the cylindrical member. As a result, a light gas 96 seal layer is formed below the light transmission window 52. can do.

  The light gas supplied to the inner space of the cylindrical member is not particularly limited as long as it is lighter than the atmospheric gas in the chamber. That is, it is sufficient that the specific gravity of the light gas is smaller than the specific gravity of the atmospheric gas in the chamber. For example, when the atmospheric gas in the chamber is nitrogen gas, the low temperature gas may be argon gas and / or helium gas.

  The temperature of the light gas 96 charged in the inner space of the cylindrical member 80 is preferably higher than the temperature of the atmospheric gas in the chamber. As a result, the light gas 96 tends to stay in the inner space of the cylindrical member due to the temperature difference from the atmospheric gas in the chamber, so that the seal layer of the light gas 96 can be stabilized.

  In addition to supplying “cold gas 90” or “light gas 96” to the inner space of the tubular member, an annular gas flow may be additionally formed. More specifically, as shown in FIGS. 12 and 13, an annular gas flow may be formed by flowing gas downward from the lower end portion of the cylindrical member 80. Accordingly, in combination with the effect of the “cold gas 90” or “light gas 96” provided inside the cylindrical member, the fumes are further easily moved outward in the horizontal direction. That is, it becomes easier for the fumes to flow away from the light transmission window and the light beam path, and fogging of the light transmission window and attenuation of the light beam can be more effectively prevented.

  The annular gas flow is preferably formed by flowing gas downward from the lower end of the cylindrical member 80 in the vertical direction. In this case, it is only necessary to form an annular gas flow that is substantially downward, and the direction of the gas flow is within a range of ± 20 ° or ± 10 ° (for example, a range of ± 5 °) from the vertical downward direction. Just enter.

  An annular gas supply member 70 may be used to form the annular gas flow. For example, the annular gas supply member 70 (particularly, the gas discharge portion 72) is provided at the lower end of the cylindrical member 80, and the gas flow is supplied from the annular gas supply member so provided so that the starting point of the gas flow is The lower end can be formed (see FIGS. 12 and 13). As shown in FIGS. 12 and 13, the gas introduction line 71 of the annular gas supply member is preferably configured to pass through the body portion of the cylindrical member 80.

  The annular gas supply member 70 is preferably composed of a gas introduction line 71 and an annular gas discharge portion 72 communicating therewith. As shown in the drawing, if the light transmission window 52 is a disc shape, the cross-section of the cylindrical member is preferably circular correspondingly, and therefore the gas discharge portion 72 preferably has a ring shape. The form of the gas discharge part 72 is not particularly limited as long as a “downward annular gas flow” is formed. For example, as shown in FIG. 14A, a plurality of openings 72a of the gas discharge part 72 are locally provided. It may be a mode provided, or may be a mode in which the opening 72b of the gas discharge part 72 has a slit shape as shown in FIG. 14B (in addition, the cross section of the gas discharge part 72) The shape is not limited to a rectangle but may be a circle as shown in the figure).

  The gas flow rate supplied from the annular gas supply member 70 (particularly the gas flow rate flowing through the gas introduction line 71) is preferably about 5 to 80 L / min, more preferably about 10 to 60 L / min, and still more preferably 15 to 40 L / min. It is about min (gas flow rate based on a standard state of 0 ° C. and 1 atm).

  The type of gas used for the “annular gas flow” is not particularly limited, and various gases can be used. For example, the same type of gas as the atmospheric gas charged in the chamber may be used. For example, “air” is preferably used from the viewpoint of cost. Moreover, it is preferable to use inert gas, such as nitrogen gas, from a viewpoint of oxidation prevention of a powder layer and a molded article.

  A fan may be used to form the annular gas flow. Specifically, as shown in FIG. 15, the annular gas flow may be formed by driving a fan 99 provided inside the chamber 50. For example, as shown in the figure, a downward gas flow can be locally formed by rotating at least two propellers provided at the lower end portion of the cylindrical member 80, whereby an annular gas flow can be formed. In such a fan drive mode, the atmospheric gas in the chamber system moves locally and can be operated in a substantially closed system. In the embodiment shown in FIG. 15, the rotation speed of the propeller is not particularly limited as long as a downward local gas flow can be formed, but may be, for example, about 50 to 300 rpm.

  The annular gas flow may be formed only during irradiation with the light beam. That is, the gas supply (the mode shown in FIGS. 12 and 13) and the fan drive (the mode shown in FIG. 15) may be performed only when the light beam is irradiated. Thereby, the “annular gas flow” can be formed synchronously when fumes are generated, and the running cost (≈operation cost) can be reduced. In such an embodiment, the “irradiation time data” output to the light beam oscillator is also output to the gas supply pump and the fan drive unit in the same manner, whereby a gas flow synchronized with the generation of fumes can be formed.

  In the present invention, the fumes can be moved radially away from the light transmission window due to the “gas inside the cylindrical member” and / or “annular gas flow” (FIGS. 9, 11, 12 and FIG. 13 etc.). That is, the upward flow of the fume changes into a radial flow. More specifically, as shown in FIG. 9, FIG. 11, FIG. 12, and FIG. 13, etc., "rising fume" is formed into a light transmission window by "gas inside the cylindrical member" and / or "annular gas flow". It changes so that it may flow toward the peripheral area | region of a chamber centering on the horizontal position of this. From another viewpoint, the rise of the fume is suppressed by the “gas inside the cylindrical member” and / or the “annular gas flow”, whereby the suppressed fume moves outward in the horizontal direction. That is, it is possible to effectively prevent fogging of the light transmission window and attenuation of the light beam due to such a flow change.

[Production apparatus of the present invention]
Next, an apparatus suitable for carrying out the production method of the present invention will be described (this will be described taking an example in which a metal powder is used as the powder and the solidified layer is a sintered layer). Such an apparatus, as shown in FIGS. 1, 2, 4 and 5,
Powder layer forming means 2 for forming a metal powder layer;
A light beam irradiation means 3 for irradiating the metal powder layer with a light beam so as to form a sintered layer;
A modeling table 20 on which a metal powder layer and / or a sintered layer is to be formed, and a chamber 50 having therein a metal powder layer forming means and a modeling table.
Comprising
The cylinder member 80 that surrounds the lower space region of the light transmission window provided in the chamber, and means for supplying a gas having a temperature or type different from the atmosphere in the chamber into the cylinder member 80 is further provided. Become.

  The “powder layer forming means 2”, “modeling table 20”, “light beam irradiation means 3”, “chamber 50”, “cylinder member 80”, etc. Since it is described in [Lamination method] and [Production method of the present invention], the description is omitted to avoid duplication. The “means for supplying a gas having a temperature or type different from the atmosphere in the chamber into the cylinder member 80” may be, for example, a “temperature controller 93, 97 and a pump as shown in FIG. Gas introduction lines 94a and 98a provided, and gas discharge portions 94b and 98b "connected to the lines.

  As described above, the preferred embodiment of the present invention has been described mainly. However, the present invention is not limited to this, and those skilled in the art can easily understand that various modifications can be made. For example, the following modifications can be considered.

  In order to prevent the accumulation of fumes in the chamber more than necessary, the fumes moved outward in the horizontal direction may be appropriately discharged from the chamber. For example, the fumes may be discharged from the chamber outlet when a certain amount of fumes is accumulated in the gas flow. Such fumes can be discharged, for example, by simply opening the closed chamber outlet.

(Conventional technology)
Lastly, although it is essentially different from the technical idea of the present invention, a special table 9-511893 is added. Japanese Patent Application Laid-Open No. 9-511893 discloses an “apparatus for producing an object in layers using laser sintering”. In the disclosed apparatus, nitrogen is passed through the lens that focuses the beam. In particular, it has been devised to flow over the entire lens surface, and there is no disclosure or suggestion of the idea of the present invention such as "supplying a temperature or type of gas different from the atmosphere in the chamber to the inside of the cylindrical member" Please note that.

DESCRIPTION OF SYMBOLS 1 Optical modeling combined processing machine 2 Powder layer formation means 3 Light beam irradiation means 4 Cutting means 8 Fume 19 Powder / powder layer (For example, metal powder / metal powder layer or resin powder / resin powder layer)
20 modeling table 21 modeling plate 22 powder layer (for example, metal powder layer or resin powder layer)
23 Blade for squeezing 24 Solidified layer (for example, sintered layer or resin layer) or molded object 25 obtained therefrom Powder table 26 Wall part of powder material tank 27 Wall part of modeling tank 28 Powder material tank 29 Modeling tank 30 Light beam oscillator 31 Galvano mirror 40 Milling head 41 XY drive mechanism 50 Chamber 50a Chamber wall surface 50b Upper inner wall 52 of chamber 52 Light transmission window or lens 70 Annular gas supply member 71 Gas introduction line 72 Gas discharge part 80 Cylindrical member 90 Low temperature gas 93 For low temperature gas Temperature controller 94a Low temperature gas introduction line 94b Low temperature gas discharge section 96 Light gas 97 Temperature controller 98a for light gas Light gas introduction line 98b Light gas discharge section 99 Fan L Light beam

Claims (10)

(I) irradiating a predetermined portion of the powder layer with a light beam to sinter or melt-solidify the powder at the predetermined portion to form a solidified layer; and (ii) a new powder on the obtained solidified layer. Forming a layer, irradiating a predetermined portion of the new powder layer with a light beam to form a further solidified layer in a chamber, and a method for producing a three-dimensional shaped object,
A cylindrical member that surrounds a lower space region of the light transmission window provided in the chamber is provided , and the solidified layer is formed by supplying a gas having a temperature or type different from the atmosphere in the chamber to the inside of the cylindrical member. A method for producing a three-dimensional shaped object, wherein fumes generated in the process are moved outward in the horizontal direction of the cylindrical member .   Due to the difference in temperature between the low temperature gas and the atmosphere in the chamber, a gas having a temperature or type different from that in the chamber atmosphere is supplied to the inside of the cylindrical member. The method for producing a three-dimensional shaped object according to claim 1, wherein the low-temperature gas is moved downward by natural convection.   As the gas having a temperature or type different from the atmosphere in the chamber, a gas lighter than the gas in the chamber atmosphere is charged into the cylindrical member, and the solidification is performed in a state where the light gas is present in the cylindrical member. The method for producing a three-dimensional shaped article according to claim 1, wherein a layer is formed.   The method for producing a three-dimensional shaped object according to claim 3, wherein argon or helium is used as the light gas.   The method for producing a three-dimensional shaped article according to claim 3 or 4, wherein a gas having a temperature higher than the temperature of the atmosphere in the chamber is used as the light gas.   The method for producing a three-dimensional shaped object according to any one of claims 1 to 5, wherein an annular gas flow is additionally formed by flowing a gas from a lower end portion of the cylindrical member.   7. The tertiary according to claim 6, wherein an annular gas supply member is provided at the lower end portion of the cylindrical member, and the annular gas flow is formed by supplying gas downward from the annular gas supply member. Manufacturing method of original shaped object.   The method for producing a three-dimensional shaped object according to claim 6, wherein the annular gas flow is formed by driving a fan provided in the chamber.   The method for producing a three-dimensional shaped object according to any one of claims 6 to 8, wherein the annular gas flow is formed only at the time of irradiation with the light beam. Powder layer forming means for forming a powder layer,
A light beam irradiation means for irradiating the powder layer with a light beam so as to form a solidified layer;
A molding table on which a powder layer and / or a solidified layer is to be formed; and a chamber having a powder layer forming means and a molding table therein,
The solidified layer is formed by supplying a cylinder member that surrounds a lower space region of the light transmission window provided in the chamber, and a gas having a temperature or type different from the atmosphere in the chamber to the inside of the cylinder member. An apparatus for producing a three-dimensional shaped object, further comprising means for moving fumes generated at the time to the outside in the horizontal direction of the cylindrical member .