Patent Publication Number: US-2023132492-A1

Title: Additive manufacturing device and blowing nozzle

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present disclosure relates to an additive manufacturing device and a blowing nozzle. 
     Priority is claimed on Japanese Patent Application No. 2021-180163, filed Nov. 4, 2021, the content of which is incorporated herein by reference. 
     Description of Related Art 
     Japanese Unexamined Patent Application, First Publication No. 2016-006215 discloses an additive manufacturing device including a chamber having an additive manufacturing space covering an additive manufacturing region and filled with an inert gas having a predetermined concentration, and a fume diffusion part attached to an upper surface of the chamber. In this additive manufacturing device, the fume diffusion part includes a housing having an opening that is as small as possible to such an extent that it does not block laser light irradiated to the additive manufacturing region, and an inert gas supply path that fills the inside of the housing with an inert gas of the same type as the inert gas in the additive manufacturing space. Thereby, the inert gas can be ejected from the above-described opening to form a laminar flow of the inert gas along an irradiation path of the laser light, and thereby fumes can be removed from the irradiation path. The above-described opening is circular and supplies the inert gas all around the opening. 
     SUMMARY OF THE INVENTION 
     However, in the additive manufacturing device described in Japanese Unexamined Patent Application, First Publication No. 2016-006215, an inert gas ejected downward from the above-described opening collides with an inner side surface of the chamber and generates a circulating flow. As a result, there is concern that fumes will be caught in the circulating flow and will not be sufficiently discharged from the inside of the chamber. If biasing in fume removal performance occurs in the chamber, laser light may be blocked by the fumes in a region in which the fumes remain, sufficient heat cannot be applied to a material powder, and thereby the quality of additive manufacturing may deteriorate. Therefore, there is a problem that variations in quality of additive manufacturing are caused. 
     The present disclosure has been made to solve the above problems, and an objective thereof is to provide an additive manufacturing device and a blowing nozzle capable of suppressing variations in quality of additive manufacturing. 
     In order to solve the above-described problems, an additive manufacturing device according to the present disclosure includes a bottom portion having an additive manufacturing area on which an additive manufacturing article is additively manufactured, a ceiling portion positioned above the bottom portion and having a blowing part for an inert gas, a side portion standing upward from a side end portion of the bottom portion, and a discharge port of the inert gas, in which under a condition where a first direction is oriented from the additive manufacturing area toward the discharge port in a direction parallel to the bottom portion and a second direction is oriented across the first direction in the direction parallel to the bottom portion, a first width of the blowing part in the second direction is larger than a second width of the blowing part in the first direction and is equal to or larger than a third width of the additive manufacturing area in the second direction. 
     An additive manufacturing device according to the present disclosure includes a bottom portion having an additive manufacturing area on which an additive manufacturing article is additively manufactured, a ceiling portion positioned above the bottom portion and having a blowing part for an inert gas, a side portion standing upward from a side end portion of the bottom portion, and a discharge port of the inert gas, in which under a condition where a first direction is oriented from the additive manufacturing area toward the discharge port in a direction parallel to the bottom portion and a second direction is oriented across the first direction in the direction parallel to the bottom portion, a first width of the blowing part in the second direction is larger than a second width of the blowing part in the first direction and is equal to or larger than a third width of the additive manufacturing article in the second direction. 
     An additive manufacturing device according to the present disclosure includes a bottom portion having an additive manufacturing area on which an additive manufacturing article is additively manufactured, a ceiling portion positioned above the bottom portion and having a blowing part for an inert gas and a first laser irradiation window, a side portion standing upward from a side end portion of the bottom portion, and a discharge port of the inert gas, in which under a condition where a first direction is oriented from the additive manufacturing area toward the discharge port in a direction parallel to the bottom portion and a second direction is oriented across the first direction in the direction parallel to the bottom portion, a first width of the blowing part in the first direction is smaller than a second width of the first laser irradiation window in the first direction, and a width of the blowing part in the second direction is larger than a third width of the first laser irradiation window in the second direction. 
     A blowing nozzle according to the present disclosure is attachable to an additive manufacturing device and includes a first end portion having an introduction part of an inert gas, and a second end portion positioned on a side opposite to the first end portion and including a blowing part for the inert gas, in which, under a condition where a first direction is oriented in a direction parallel to the second end portion and a second direction is oriented across the first direction in the direction parallel to the second end portion, the blowing nozzle includes a flat part extending in the second direction at least at the second end portion, and a first width of the blowing part in the second direction is larger than a second width of the blowing part in the first direction. 
     According to the additive manufacturing device and the blowing nozzle of the present disclosure, variations in quality of additive manufacturing can be suppressed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a perspective view of an additive manufacturing device according to a first embodiment of the present disclosure. 
         FIG.  2    is a plan view of a ceiling portion according to the first embodiment of the present disclosure. 
         FIG.  3    is a view illustrating a flow of an inert gas according to the first embodiment of the present disclosure. 
         FIG.  4    is a perspective view of an additive manufacturing device according to a modified example of the first embodiment of the present disclosure. 
         FIG.  5    is a plan view of a ceiling portion according to a second embodiment of the present disclosure. 
         FIG.  6    is a plan view of a ceiling portion according to a third embodiment of the present disclosure. 
         FIG.  7    is a perspective view of an additive manufacturing device according to a fourth embodiment of the present disclosure. 
         FIG.  8    is a perspective view of a blowing nozzle according to the fourth embodiment of the present disclosure. 
         FIG.  9    is a plan view of a ceiling portion according to the fourth embodiment of the present disclosure. 
         FIG.  10    is a cross-sectional view in a second direction of the blowing nozzle according to the fourth embodiment of the present disclosure. 
         FIG.  11    is a side view of an additive manufacturing device according to a fifth embodiment of the present disclosure from a first direction. 
         FIG.  12    is a plan view of a rectifying member according to the fifth embodiment of the present disclosure from below. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     First Embodiment 
     (Additive Manufacturing Device) 
     Hereinafter, an additive manufacturing device  1  according to a first embodiment of the present disclosure will be described with reference to  FIGS.  1  to  3   . 
     The additive manufacturing device  1  illustrated in  FIG.  1    is, for example, a so-called powder head-type 3D printer. The additive manufacturing device  1  additively manufactures an additive manufacturing article S using a material powder as a raw material. More specifically, the additive manufacturing device  1  irradiates a material powder of a metal with laser light L to sinter it and form a sintered layer, and laminates the sintered layer to form the additive manufacturing article S. 
     As illustrated in  FIG.  1   , the additive manufacturing device  1  includes a laser irradiation unit  2  and a chamber  3 . Further, the additive manufacturing device  1  includes a material supply unit, a control unit, and the like (not illustrated) in addition to the laser irradiation unit  2  and the chamber  3 . Since various well-known devices can be used for this material supply unit, control unit, and the like, detailed description thereof will be omitted here. Also, in  FIG.  1   , the laser irradiation unit  2  and the chamber  3  are illustrated in a simplified manner so that the description can be better understood. In  FIG.  1   , for example, a taking-out port or the like of the additive manufacturing article S is omitted. 
     The laser irradiation unit  2  includes a laser light source (not illustrated) and an irradiation control unit (not illustrated). The laser light source illuminates the laser light L. The laser light L may be any one as long as it can sinter the material powder. The laser light L is, for example, a CO 2  laser, a fiber laser, an yttrium aluminum garnet (YAG) laser, or the like. The laser light source emits the generated laser light L downward. The irradiation control unit controls irradiation of the laser light L to move the laser light L two-dimensionally along a plane parallel to a horizontal direction. 
     (Chamber) 
     The chamber  3  is disposed below the laser irradiation unit  2 . In the chamber  3 , the additive manufacturing article S is additively manufactured. The chamber  3  includes a bottom portion  10 , a ceiling portion  20 , and a side portion  30 . 
     (Bottom Portion) 
     The bottom portion  10  lies along the horizontal direction. A first direction D 1  is one of directions parallel to the bottom portion  10 . A second direction D 2  is the other of the directions parallel to the bottom portion  10  and is oriented across (for example, perpendicular to) the first direction D 1 . 
     The bottom portion  10  is formed in a rectangular shape in a plan view (that is, when viewed from above). The bottom portion  10  has four side end portions  11 . The four side end portions  11  extend in one of the first direction D 1  and the second direction D 2 . The bottom portion  10  has a stage  12  at a central part. The stage  12  is formed in a rectangular shape in a plan view. Each edge of the stage  12  extends in one of the first direction D 1  and the second direction D 2 . The stage  12  is able to be raised and lowered vertically. An upper surface of the stage  12  is an additive manufacturing area  13  on which the additive manufacturing article S is additively manufactured. Further, “additive manufacturing area” described in the present disclosure is not limited to a stage that can be raised and lowered and may be part of the bottom portion  10  at a fixed position. An “additive manufacturing area” as used in the present disclosure means an area in the bottom portion  10  where the additive manufacturing article S is additively manufactured. For example, the “additive manufacturing area” means an area of the bottom portion  10  that is irradiated with the laser light L. 
     (Ceiling Portion) 
     The ceiling portion  20  is positioned above the bottom portion  10 . The ceiling portion  20  includes a ceiling portion main body  21 , one or more (for example, a plurality of) laser irradiation windows  22 , and a blowing part  4 . 
     (Ceiling Portion Main Body) 
     The ceiling portion main body  21  vertically partitions a space inside the chamber  3 . The ceiling portion main body  21  is formed in a plate shape extending in the horizontal direction. The ceiling portion main body  21  is formed on the side portion  30  so as to cover the entire additive manufacturing area  13 . 
     (Laser Irradiation Window) 
     As illustrated in  FIG.  2   , a total of four laser irradiation windows  22  are provided at a central part of the ceiling portion main body  21 . The laser irradiation windows  22  each face the laser irradiation unit  2  in a vertical direction. The laser irradiation window  22  is formed of a material that can transmit the laser light L (see  FIG.  1   ) output from the laser irradiation unit  2 . When the laser light L is illuminated from a fiber laser or a YAG laser, the laser irradiation window  22  is formed of, for example, quartz glass. The laser irradiation windows  22  are formed to have the same shape and size. The laser irradiation window  22  is formed in a disc shape. A plate thickness direction of the laser irradiation window  22  coincides with the vertical direction. For example, the four laser irradiation windows  22  are disposed so that center points thereof draw a rectangle in a plan view. The four laser irradiation windows  22  are positioned inside the additive manufacturing area  13  in a plan view. 
     The four laser irradiation windows  22  include two first laser irradiation windows  23  and two second laser irradiation windows  24  aligned in the second direction D 2 . The two first laser irradiation windows  23  are aligned in the first direction D 1 . The two second laser irradiation windows  24  are aligned in the first direction D 1 . Further, a disposition of the laser irradiation windows  22  is not limited to the above-described example. For example, the first laser irradiation windows  23  and the second laser irradiation windows  24  are not limited to the disposition in which they are completely aligned in the second direction D 2 . The first laser irradiation windows  23  and the second laser irradiation windows  24  may be disposed offset from each other in the first direction D 1  so that they are partially aligned in the second direction D 2 . 
     (Blowing Part) 
     The blowing part  4  is a blowing part for an inert gas G. The blowing part  4  is provided in the ceiling portion main body  21 . The blowing part  4  blows out the inert gas G from the ceiling portion main body  21  toward the bottom portion  10  (that is, downward). The inert gas G is a gas that does not substantially react with the material powder. The inert gas G is, for example, nitrogen gas, argon gas, helium gas, or the like. In the present embodiment, the blowing part  4  is an opening (blowing opening  25 ) that opens in the ceiling portion main body  21 . For example, the blowing part  4  is provided at a central part of the ceiling portion main body  21 . 
     As illustrated in  FIG.  2   , the blowing opening  25  is formed in a rectangular shape extending in the second direction D 2  in a plan view. In the present embodiment, a width W 1   b  of the blowing part  4  in the second direction D 2  is larger than a width W 1   a  of the blowing part  4  in the first direction D 1  and is equal to or larger than a width W 2  of the additive manufacturing area  13  in the second direction D 2 . 
     From another point of view, the width W 1   b  of the blowing part  4  in the second direction D 2  is equal to or larger than a width W 4  of the additive manufacturing article S in the second direction D 2 . 
     Also, from another point of view, the width W 1   a  of the blowing part  4  in the first direction D 1  is smaller than a width W 5   a  of the laser irradiation window  22  (for example, the first laser irradiation window  23 ) in the first direction D 1 . The width W 1   b  of the blowing part  4  in the second direction D 2  is larger than a width W 5   b  of the laser irradiation window  22  (for example, the first laser irradiation window  23 ) in the second direction D 2 . 
     In the present embodiment, the blowing part  4  is provided between a plurality of laser irradiation windows  22 . More specifically, the blowing part  4  is positioned between the two first laser irradiation windows  23  and between the two second laser irradiation windows  24 . In the present embodiment, the blowing part  4  includes a first portion  4   a  aligned with the first laser irradiation windows  23  in the first direction D 1  and a second portion  4   b  aligned with the second laser irradiation windows  24  in the first direction D 1  in a plan view. 
     Furthermore, the blowing part  4  has a third portion  4   c  and a fourth portion  4   d . The third portion  4   c  is a portion positioned farther away than the first laser irradiation window  23  in the second direction D 2  when viewed from a center C of the additive manufacturing area  13  in a plan view. On the other hand, the fourth portion  4   d  is a portion positioned farther away than the second laser irradiation window  24  in the second direction D 2  when viewed from the center C of the additive manufacturing area  13  in a plan view. 
     (Side Portion) 
     Returning to  FIG.  1   , the side portion  30  will be described. The side portion  30  is provided to stand upward from the side end portion  11  of the bottom portion  10 . The side portion  30  includes a pair of first side portions  31  facing in the first direction D 1  and a pair of second side portions  32  facing in the second direction D 2 . The pair of first side portions  31  each include a discharge port  33  of the inert gas G. 
     (Discharge Port) 
     The discharge port  33  is provided at a lower part of the first side portion  31 . A pair of discharge ports  33  are provided to face each other in the first direction D 1 . The pair of discharge ports  33  are formed to have the same shape and size. The discharge ports  33  are each formed in a rectangular shape extending in the second direction D 2 . The discharge port  33  opens toward the additive manufacturing area  13 . The discharge port  33  extends along the additive manufacturing area  13 . A width W 3  of the discharge port  33  in the second direction D 2  is substantially the same as the width W 2  of the additive manufacturing area  13  in the second direction D 2 . A direction from the additive manufacturing area  13  toward the discharge port  33  parallel to the bottom portion  10  coincides with the first direction D 1 . 
     (Operation and Effects) 
     When additive manufacturing is performed using the additive manufacturing device  1  described above, first, a material powder is laid flat on the additive manufacturing area  13  to form a layer of the material powder. The laser light L is applied to the material powder laid on the additive manufacturing area  13 . The material powder is sintered by the laser light L. Thereby, a first sintered layer is formed in the additive manufacturing area  13 . Thereafter, the stage  12  is lowered by the thickness of one sintered layer. The material powder is laid on the first sintered layer, and a second sintered layer is formed in the same procedure. This procedure is repeated to laminate a plurality of sintered layers. Adjacent sintered layers are strongly fixed to each other. When the plurality of formed sintered layers are fixed, additive manufacturing of the additive manufacturing article S is completed. After the additive manufacturing of the additive manufacturing article S, unsintered material powder is removed. 
     If additive manufacturing is performed as described above, when the material powder is irradiated with the laser light L, the heat of the laser light L causes fumes P 1  and spatters P 2  to be generated from the material powder. The fumes P 1  and the spatters P 2  block the laser light L, and this becomes a cause of deterioration in performance of the additive manufacturing device  1 . Therefore, it is necessary to remove the fumes P 1  and the spatters P 2  from the inside of the chamber  3 . A method of removing the fumes P 1  and the spatters P 2  will be described below with reference to  FIG.  3   . 
     (Method of Removing Fumes and Spatters) 
     As illustrated in  FIG.  3   , the blowing part  4  blows out the inert gas G downward toward the additive manufacturing area  13 . A flow of the inert gas G blown out from the blowing part  4  forms a two-dimensional flow along a virtual plane extending in the vertical direction and a uniform flow in the second direction D 2 . The inert gas G collides with a central part of the additive manufacturing area  13 . When the inert gas G collides with the additive manufacturing area  13 , it flows from the central part of the additive manufacturing area  13  toward an outer side in the first direction D 1 . At this time, the inert gas G flows along the additive manufacturing area  13 . The flow of the inert gas G along the additive manufacturing area  13  becomes a uniform flow in the first direction D 1  and the second direction D 2 . The flow of the inert gas G along the additive manufacturing area  13  occurs in an area wider than that of the additive manufacturing area  13  including the entire region of the additive manufacturing area  13 . Thereafter, the inert gas G is discharged to the outside of the chamber  3  from the discharge port  33 . 
     Due to the flow of the inert gas G described above, the fumes P 1  and the spatters P 2  are quickly discharged to the outside of the chamber  3  from the discharge port  33 . In this manner, the fumes P 1  and the spatters P 2  are removed from the inside of the chamber  3 . 
     Here, as a comparative example, a configuration in which a circular or relatively small oval-shaped blowing part for the inert gas G is provided in the ceiling portion main body  21  may be conceived. In such a configuration, the inert gas G ejected downward from the blowing part collides with the additive manufacturing area  13  and then flows along the additive manufacturing area  13  to spread all around. As a result, the inert gas G collides with the second side portion  32  and generates a circulating flow in the vicinity of the second side portion  32  in which the discharge port  33  is not provided. As a result, the fumes P 1  and the spatters P 2  may be caught in the circulating flow and may not be sufficiently discharged from the inside of the chamber  3 . 
     On the other hand, the width W 1   b  of the blowing part  4  in the second direction D 2  is larger than the width W 1   a  of the blowing part  4  in the first direction D 1  and is equal to or larger than the width W 2  of the additive manufacturing area  13  in the second direction D 2 . 
     Thereby, in the blowing part  4 , the flow of the inert gas G can be made uniform in the second direction D 2  while being aligned in parallel. The flow of the inert gas G blown out from the blowing part  4  has a two-dimensional and uniform flow along a virtual plane extending in the vertical direction. Further, the inert gas G can be made to collide with the entire additive manufacturing area  13  in the second direction D 2 . The inert gas G that has collided with the additive manufacturing area  13  flows in the first direction D 1  along the additive manufacturing area  13  and is discharged from the discharge port  33 . The flow of the inert gas G along the additive manufacturing area  13  has a uniform flow. The flow of the inert gas G suppresses generation of a circulating flow that rolls upward along the second side portion  32  from the bottom portion  10 . Therefore, the inert gas G is guided to the discharge port  33  without remaining. Thereby, the fumes P 1  and the spatters P 2  being caught in the circulating flow can be suppressed. The fumes P 1  and the spatters P 2  can be discharged from the discharge port  33  by the flow of the inert gas G along the additive manufacturing area  13 . Therefore, the fumes P 1  and the spatters P 2  can be removed without being biased within the additive manufacturing area  13 , and the fumes P 1  and the spatters P 2  blocking the laser light L irradiated to the additive manufacturing article S can be evenly suppressed within the additive manufacturing area  13 . Therefore, variations in quality of additive manufacturing can be suppressed. 
     Also, since the flow of the inert gas G along the additive manufacturing area  13  has a uniform flow, supply and exhaust of the inert gas G are performed uniformly and quickly on the additive manufacturing area  13 . Therefore, the fumes P 1  and the spatters P 2  can be satisfactorily discharged by the flow of the inert gas G. 
     Further, an interference vortex of the inert gas G may occur outside the collision position of the inert gas G in the second direction D 2 . In the present embodiment, the width W 1   b  of the blowing part  4  in the second direction D 2  is equal to or larger than the width W 2  of the additive manufacturing area  13  in the second direction D 2 . Therefore, the interference vortex can be positioned outside the additive manufacturing area  13 . Thereby, the fumes P 1  and the spatters P 2  caught in the interference vortex blocking the laser light L irradiated to the additive manufacturing article S can be suppressed. 
     In the present embodiment, the blowing part  4  is an opening (blowing opening  25 ) provided in the ceiling portion main body  21 . Thereby, the blowing part  4  can be formed by simple processing of simply forming the blowing opening  25  in the ceiling portion main body  21 . Therefore, a manufacturing process of the additive manufacturing device  1  can be reduced. 
     In the present embodiment, the blowing part  4  is provided between the plurality of laser irradiation windows  22 . Therefore, the laser light L irradiated from the laser irradiation windows  22  is not interfered by being blocked by the blowing part  4  or the like. Thereby, the blowing part  4  can be provided without changing a structure of the laser irradiation windows  22  or the like. 
     Modified Example of First Embodiment 
     The discharge port  33  of the inert gas G may be provided in the bottom portion  10 . In this case, the discharge port  33  is disposed on an outer side of the additive manufacturing area  13  in the first direction D 1 . 
     Also, as illustrated in  FIG.  4   , the additive manufacturing device  1  may include a flow path member  34  having the discharge port  33 . The flow path member  34  is, for example, a pipe provided in the first side portion  31 . The flow path member  34  extends in the vertical direction along the first side portion  31 . A plurality of flow path members  34  are provided at intervals in the second direction D 2 . A lower end portion of each of the flow path members  34  bends inward in the first direction D 1  in the vicinity of the bottom portion  10  and opens toward the additive manufacturing area  13 . A lower opening of the flow path member  34  serves as the discharge port  33  of the inert gas G. The inert gas G is introduced into the inside of the flow path member  34  from the discharge port  33 , flows upward through the flow path member  34 , and is discharged to the outside of the chamber  3  through an upper opening (not illustrated) of the flow path member  34 . 
     Further, the flow path member  34  is not limited to a pipe, and may be, for example, a fan or the like that allows the inside and outside of the chamber  3  to communicate. 
     Second Embodiment 
     Hereinafter, an additive manufacturing device  1 A according to a second embodiment of the present disclosure will be described with reference to  FIG.  5   . In the second embodiment, components the same as those in the first embodiment will be denoted by the same reference signs and detailed description thereof will be omitted. Configurations of the second embodiment other than those described below are the same as the configurations of the first embodiment. 
     As illustrated in  FIG.  5   , there are cases in which an additive manufacturing area  13  is partially used in additive manufacturing. Hereinafter, a portion of the additive manufacturing area  13  that is actually used for additive manufacturing of an additive manufacturing article S is referred to as a use area  14 . In the present embodiment, a width W 1   b  of a blowing part  4  in a second direction D 2  is larger than a width W 1   a  of the blowing part  4  in a first direction D 1  and is equal to or larger than a width of the use area  14  of the additive manufacturing area  13  in the second direction D 2 . That is, the width W 1   b  of the blowing part  4  in the second direction D 2  is equal to or larger than the width W 4  of the additive manufacturing article S in the second direction D 2 . In the present embodiment, the width W 1   b  of the blowing part  4  in the second direction D 2  is smaller than the width W 2  of the additive manufacturing area  13  in the second direction D 2 . 
     (Operation and Effects) 
     In the present embodiment, the width W 1   b  of the blowing part  4  in the second direction D 2  is larger than the width W 1   a  of the blowing part  4  in the first direction D 1  and is equal to or larger than the width W 4  of the additive manufacturing article S in the second direction D 2 . 
     Thereby, in the blowing part  4 , a flow of an inert gas G can be made uniform in the second direction D 2  while being aligned in parallel. The flow of the inert gas G blown out from the blowing part  4  has a two-dimensional and uniform flow along a virtual plane extending in the vertical direction. Further, the inert gas G can be made to collide with the entire of the additive manufacturing article S in the second direction D 2 . The inert gas G that has collided with the additive manufacturing article S flows in the first direction D 1  along the additive manufacturing area  13  and is discharged from a discharge port  33 . The flow of the inert gas G along the additive manufacturing area  13  has a uniform flow at least in the use area  14 . Such a flow of inert gas G suppresses generation of a circulating flow that rolls upward along a second side portion  32  from a bottom portion  10 . Therefore, the inert gas G is guided to the discharge port  33  without remaining. Thereby, fumes P 1  and spatters P 2  being caught in the circulating flow can be suppressed. Fumes P 1  and spatters P 2  can be discharged from the discharge port  33  by the flow of the inert gas G along the additive manufacturing area  13 . Therefore, the fumes P 1  and the spatters P 2  can be removed without being biased at least within the use area  14 , and the fumes P 1  and the spatters P 2  blocking laser light L irradiated to the additive manufacturing article S can be evenly suppressed at least within the use area  14 . Therefore, variations in quality of additive manufacturing can be suppressed. 
     Also, since the flow of the inert gas G along the additive manufacturing area  13  has a uniform flow at least within the use area  14 , supply and exhaust of the inert gas G are performed uniformly and quickly at least on the use area  14 . Therefore, the fumes P 1  and the spatters P 2  can be satisfactorily discharged by the flow of the inert gas G. 
     Also, the width W 1   b  of the blowing part  4  in the second direction D 2  is equal to or larger than the width W 4  of the additive manufacturing article S in the second direction D 2 . Therefore, an interference vortex can be positioned outside the additive manufacturing article S, that is, outside the use area  14 . Thereby, the fumes P 1  and the spatters P 2  caught in the interference vortex blocking the laser light L irradiated to the additive manufacturing article S can be suppressed. 
     Third Embodiment 
     Hereinafter, an additive manufacturing device  1 B according to a third embodiment of the present disclosure will be described with reference to  FIG.  6   . In the third embodiment, components the same as those in the first embodiment will be denoted by the same reference signs and detailed description thereof will be omitted. Configurations of the third embodiment other than those described below are the same as the configurations of the first embodiment. 
     As illustrated in  FIG.  6   , a width W 1   a  of a blowing part  4  in a first direction D 1  is smaller than a width W 5   a  of a laser irradiation window  22  (for example, a first laser irradiation window  23 ) in the first direction D 1 , and a width W 1   b  of the blowing part  4  in a second direction D 2  is larger than a width W 5   b  of the laser irradiation window  22  (for example, the first laser irradiation window  23 ) in the second direction D 2 . In the present embodiment, the width W 1   b  of the blowing part  4  in the second direction D 2  is larger than a width W 4  of an additive manufacturing article S in the second direction D 2  and smaller than a width W 2  of an additive manufacturing area  13  in the second direction D 2 . 
     In the present embodiment, the blowing part  4  includes a first portion  4   a  aligned with the first laser irradiation window  23  in the first direction D 1  and a second portion  4   b  aligned with the second laser irradiation window  24  in the first direction D 1  in a plan view. 
     Furthermore, the blowing part  4  has a third portion  4   c  and a fourth portion  4   d . The third portion  4   c  is a portion positioned farther away than the first laser irradiation window  23  in the second direction D 2  when viewed from a center C of the additive manufacturing area  13  in a plan view. On the other hand, the fourth portion  4   d  is a portion positioned farther away than the second laser irradiation window  24  in the second direction D 2  when viewed from the center C of the additive manufacturing area  13  in a plan view. 
     (Operation and Effects) 
     In the present embodiment, the width W 1   a  of the blowing part  4  in the first direction D 1  is smaller than the width W 5   a  of the first laser irradiation window  23  in the first direction D 1 . The width W 1   b  of the blowing part  4  in the second direction D 2  is larger than the width W 5   b  of the first laser irradiation window  23  in the second direction D 2 . 
     Thereby, in the blowing part  4 , a flow of an inert gas G can be made uniform in the second direction D 2  while being aligned in parallel. The flow of the inert gas G blown out from the blowing part  4  has a two-dimensional and uniform flow along a virtual plane extending in the vertical direction. Further, since the inert gas G can be blown out from a wider range in the second direction D 2  than the width W 5   b  of the first laser irradiation window  23  in the second direction D 2 , the inert gas G can be made to collide with a wider range in the second direction D 2  than an area of the additive manufacturing area  13  that overlaps the first laser irradiation window  23 . The inert gas G that has collided with the additive manufacturing area  13  flows in the first direction D 1  along the additive manufacturing area  13  and is discharged from a discharge port  33 . The flow of the inert gas G along the additive manufacturing area  13  has a uniform flow at least in the area of the additive manufacturing area  13  that overlaps the first laser irradiation window  23 . The flow of the inert gas G suppresses generation of a circulating flow that rolls upward along a side portion  30  from a bottom portion  10 . Therefore, the inert gas G is guided to the discharge port  33  without remaining. Thereby, the occurrence of fumes P 1  and spatters P 2  being caught in the circulating flow can be suppressed. Fumes P 1  and spatters P 2  can be discharged from the discharge port  33  by the flow of the inert gas G along the additive manufacturing area  13 . Therefore, the fumes P 1  and the spatters P 2  can be removed without being biased at least within the area of the additive manufacturing area  13  that overlaps the first laser irradiation window  23 , and the fumes P 1  and the spatters P 2  blocking laser light L irradiated to the additive manufacturing article S can be evenly suppressed at least within the area of the additive manufacturing area  13  that overlaps the first laser irradiation window  23 . Therefore, variations in quality of additive manufacturing can be suppressed. 
     Also, since the flow of the inert gas G along the additive manufacturing area  13  has a uniform flow at least within the area of the additive manufacturing area  13  that overlaps the first laser irradiation window  23 , supply and exhaust of the inert gas G are performed uniformly and quickly at least on the area of the additive manufacturing area  13  that overlaps the first laser irradiation window  23 . Therefore, the fumes P 1  and the spatters P 2  can be satisfactorily discharged by the flow of the inert gas G. 
     Also, the inert gas G can be made to collide with a wider range in the second direction D 2  than the area of the additive manufacturing area  13  that overlaps the first laser irradiation window  23 . Therefore, an interference vortex can be positioned outside the range of the additive manufacturing area  13  that overlaps the first laser irradiation window  23 . Thereby, the fumes P 1  and the spatters P 2  caught in the interference vortex blocking the laser light L irradiated to the additive manufacturing article S can be suppressed. 
     In the present embodiment, the blowing part  4  includes the first portion  4   a  aligned with the first laser irradiation window  23  in the first direction D 1  and the second portion  4   b  aligned with the second laser irradiation window  24  in the first direction D 1  in a plan view. Thereby, the inert gas G can be blown out from a wide range corresponding to a region in which the plurality of laser irradiation windows  22  (the first laser irradiation window  23  and the second laser irradiation window  24 ) are provided. Therefore, the inert gas G can be made to collide with a wide range of the additive manufacturing area  13  corresponding to the plurality of laser irradiation windows  22 . Therefore, the fumes P 1  and the spatters P 2  can be more satisfactorily discharged by the flow of the inert gas G along the additive manufacturing area  13 . 
     Fourth Embodiment 
     Hereinafter, an additive manufacturing device  1 C according to a fourth embodiment of the present disclosure will be described with reference to  FIGS.  7  to  9   . In the fourth embodiment, components the same as those in the first embodiment will be denoted by the same reference signs and detailed description thereof will be omitted. Configurations of the fourth embodiment other than those described below are the same as the configurations of the first embodiment. 
     As illustrated in  FIG.  7   , in the present embodiment, a ceiling portion  20  includes a ceiling portion main body  21  and a blowing nozzle  40  extending downward from the ceiling portion main body  21 . In the present embodiment, a blowing part  4  is an opening (blowing port  5   b ) that opens at a lower end portion  40   b  of the blowing nozzle  40 . 
     Specifically, an attachment opening  26  to which the blowing nozzle  40  is attached is formed in the ceiling portion main body  21 . The attachment opening  26  is provided at a central part of the ceiling portion main body  21  in a plan view. The attachment opening  26  is surrounded by four laser irradiation windows  22 . The attachment opening  26  is formed in a circular shape in a plan view. 
     (Blowing Nozzle) 
     As illustrated in  FIG.  8   , the blowing nozzle  40  has an upper end portion (first end portion)  40   a  and the lower end portion (second end portion)  40   b . The lower end portion  40   b  is positioned on a side opposite to the upper end portion  40   a  in an axial direction (vertical direction) of the blowing nozzle  40 . 
     The blowing nozzle  40  is formed in a tubular shape with the upper end portion  40   a  and the lower end portion  40   b  opening. An opening of the upper end portion  40   a  of the blowing nozzle  40  is an introduction port (introduction part)  5   a  through which an inert gas G is introduced into the inside of the blowing nozzle  40 . The introduction port  5   a  is formed in a circular shape. An opening of the lower end portion  40   b  of the blowing nozzle  40  is the blowing port  5   b  through which the inert gas G is blown out. The blowing port  5   b  opens downward. The blowing port  5   b  is parallel to the first direction D 1  and the second direction D 2  described above. The size of the blowing port  5   b  will be described later. 
     The upper end portion  40   a  of the blowing nozzle  40  is detachably attached to the ceiling portion main body  21 . The introduction port  5   a  of the blowing nozzle  40  communicates with the attachment opening  26  of the ceiling portion main body  21 . That is, the blowing nozzle  40  is attached to extend downward from the ceiling portion main body  21 . 
     In one aspect, the blowing nozzle  40  includes an enlarged part  41  and an outlet part  42 . The enlarged part  41  is a portion whose width in the second direction D 2  becomes larger as it proceeds downward. For example, the enlarged part  41  is formed such that a cross-sectional shape thereof gradually changes as it proceeds downward from the introduction port  5   a . The outlet part  42  is provided below the enlarged part  41 . 
     The outlet part  42  extends downward with a fixed width in the second direction D 2 . That is, the width in the second direction D 2  is not increased in the outlet part  42 . The length L 1  of the outlet part  42  in the vertical direction is larger than, for example, a width W 1   a  of the blowing port  5   b  in the first direction D 1 . The outlet part  42  is a rectifying part that changes a flow of the inert gas G that is made to have a flow component in the second direction D 2  while passing through the enlarged part  41  into a vertically downward flow. In the present embodiment, the blowing port  5   b  is provided at a lower end of the outlet part  42 . 
     The width W 1   a  of the blowing port  5   b  in the first direction D 1  is smaller than a width W 6   a  of the introduction port  5   a  in the first direction D 1 . A width W 1   b  of the blowing port  5   b  in the second direction D 2  is larger than a width W 6   b  of the introduction port  5   a  in the second direction D 2 . The width W 1   b  of the blowing port  5   b  in the second direction D 2  is, for example, three times or more, and more specifically four times or more the width W 6   b  of the introduction port  5   a  in the second direction D 2 . 
     As illustrated in  FIG.  9   , in the present embodiment, the blowing port  5   b  is formed in a rectangular shape extending in the second direction D 2  in a plan view. In the present embodiment, the width W 1   b  of the blowing port  5   b  in the second direction D 2  is larger than the width W 1   a  of the blowing port  5   b  in the first direction D 1  and is equal to or larger than a width W 2  of an additive manufacturing area  13  in the second direction D 2 . 
     Further, a shape and size of the blowing port  5   b  are the same as a shape and size of the blowing part  4  (blowing opening  25 ) of the first embodiment. That is, “blowing part  4 ” in the description on the shape and size of the blowing part  4  in the first embodiment may be read as “blowing port  5   b ” in the description on the shape and size of the blowing port  5   b.    
     Returning to  FIG.  8   , another part of the blowing nozzle  40  will be described. In the present embodiment, the blowing nozzle  40  includes a flat part  43 . The flat part  43  is provided at least in the lower end portion  40   b  of the blowing nozzle  40 . In the present embodiment, the flat part  43  is provided across at least part of the enlarged part  41  and the outlet part  42 . 
     The flat part  43  is formed in a flat shape (hollow flat plate shape) extending in the second direction D 2 . The flat part  43  has an internal space with a constant width in the first direction D 1 . The flat part  43  is a rectifying part that straightens a flow of the inert gas G into a vertically downward flow when the inert gas G that has flowed therein from the introduction port  5   a  has a flow component in the first direction D 1 . 
     According to one aspect, the blowing nozzle  40  includes a first blowing nozzle S 1  and a second blowing nozzle S 2 . 
     The first blowing nozzle S 1  is a blowing nozzle that can be attached in exchange for, for example, a normal nozzle of the additive manufacturing device  1 . That is, a fixing structure of the first blowing nozzle S 1  with respect to the attachment opening  26  is the same as a fixing structure of a normal nozzle. Further, the first blowing nozzle S 1  may be a normal nozzle (existing nozzle) itself of the additive manufacturing device  1 . 
     In the present embodiment, the first blowing nozzle S 1  includes a first blowing nozzle main body  43   a  and a flange  44 . The first blowing nozzle main body  43   a  is formed in a tubular shape extending in the vertical direction and having both end portions in the axial direction opened. An upper opening of the first blowing nozzle main body  43   a  is the introduction port  5   a  of the inert gas G. The width of the first blowing nozzle main body  43   a  in the first direction D 1  gradually decreases downward. The width of the first blowing nozzle main body  43   a  in the second direction D 2  gradually increases downward. A lower opening of the first blowing nozzle main body  43   a  is formed in an elliptical shape extending in the second direction D 2  in a plan view. The flange  44  is provided over the entire circumference of an outer circumferential surface of a lower end portion of the first blowing nozzle main body  43   a . The flange  44  protrudes outward from the first blowing nozzle main body  43   a.    
     The second blowing nozzle S 2  is an additional nozzle (extended nozzle) attached to the first blowing nozzle S 1 . The second blowing nozzle S 2  is attached to a lower end portion of the first blowing nozzle S 1  and extends downward from the lower end portion of the first blowing nozzle S 1 . The blowing port  5   b  is provided at a lower end portion of the second blowing nozzle S 2 . 
     In the present embodiment, the second blowing nozzle S 2  includes a second blowing nozzle main body (flat part main body)  45 , a plurality of guide vanes  46  (see  FIG.  10   ), and a flange  47 . 
     The second blowing nozzle main body  45  has an outer shape formed in a flat shape extending in the vertical direction and in the second direction D 2 . The second blowing nozzle main body  45  includes the enlarged part  41 , the outlet part  42 , and the flat part  43  described above. An upper opening of the second blowing nozzle main body  45  is formed to have the same shape and size as a lower opening of the first blowing nozzle main body  43   a  and communicates with the lower opening of the first blowing nozzle main body  43   a.    
     As illustrated in  FIG.  10   , the plurality of guide vanes  46  are provided inside the second blowing nozzle main body  45 . The plurality of guide vanes  46  each extend in the vertical direction and are disposed to be aligned at regular intervals in the second direction D 2 . The guide vanes  46  each extend so that they are positioned outward in the second direction D 2  downward. The intervals between the plurality of guide vanes  46  in the second direction D 2  each increase downward. However, at a lower portion of the second blowing nozzle main body  45 , intervals between the plurality of guide vanes  46  in the second direction D 2  are constant. That is, the guide vanes  46  extend linearly in the vertical direction at the lower portion of the second blowing nozzle main body  45 . 
     The flange  47  is provided over the entire circumference of an outer circumferential surface of an upper end portion of the second blowing nozzle main body  45  (see  FIG.  8   ). The flange  47  protrudes outward from the second blowing nozzle main body  45 . The flange  47  is connected to the flange  44  of the first blowing nozzle S 1  from below. 
     (Operation and Effects) 
     In the present embodiment, the additive manufacturing device  1 C includes the blowing nozzle  40  that can be attached to the ceiling portion main body  21 . The blowing port  5   b  corresponding to the blowing part  4  (blowing opening  25 ) of the first embodiment is provided at the lower end portion of the blowing nozzle  40 . Thereby, the additive manufacturing device  1 C including the blowing port  5   b  can be obtained by attaching the blowing nozzle  40  to the ceiling portion main body  21 . That is, the blowing nozzle  40  can be retrofitted into an existing apparatus. 
     In the present embodiment, the width W 1   b  of the blowing port  5   b  in the second direction D 2  is larger than the width W 1   a  of the blowing port  5   b  in the first direction D 1  and is equal to or larger than the width W 2  of the additive manufacturing area  13  in the second direction D 2 . Thereby, the same operation and effects as those of the first embodiment can be exhibited. 
     In the present embodiment, the blowing nozzle  40  includes the flat part  43  extending in the second direction D 2  at least at the lower end portion. 
     Thereby, the flow of the inert gas G can be reduced in the process of causing the inert gas G to flow in the flat part  43 . Therefore, the flow of the inert gas G blown out from the blowing port  5   b  can be made more reliably to have a two-dimensional and uniform flow along a virtual plane extending in the vertical direction. Therefore, since occurrence of the circulating flow in the chamber  3  can be more reliably suppressed, fumes P 1  and spatters P 2  being caught in the circulating flow can be more satisfactorily suppressed. Therefore, the fumes P 1  and the spatters P 2  caught in the circulating flow blocking laser light L irradiated to an additive manufacturing article S can be more satisfactorily suppressed. 
     In the present embodiment, the blowing nozzle  40  includes the enlarged part  41  whose width in the second direction D 2  becomes larger as it proceeds downward, and the outlet part  42  provided below the enlarged part  41  and extending downward with a constant width in the second direction D 2 . The blowing part  4  is provided at a lower end portion of the outlet part  42 . 
     Thereby, the flow of the inert gas G can be aligned in the vertical direction in the process of causing the inert gas G to flow in the outlet part  42 . Therefore, the inert gas G blown out from the blowing part  4  colliding with a side portion  30  to generate a circulating flow can be more reliably suppressed until it reaches the additive manufacturing area  13 . Therefore, the fumes P 1  and the spatters P 2  being caught in the circulating flow can be more satisfactorily suppressed. Accordingly, the fumes P 1  and the spatters P 2  caught in the circulating flow blocking the laser light L irradiated to the additive manufacturing article S can be more satisfactorily suppressed. 
     In the present embodiment, the blowing nozzle  40  includes the plurality of guide vanes  46  aligned in the second direction D 2  therein. 
     Thereby, the inert gas G can be more uniformly dispersed in the second direction  2  in the process of causing the inert gas G to flow between the plurality of guide vanes  46 . Therefore, the flow of the inert gas G blown out from the blowing part  4  can be more reliably made to have a two-dimensional and uniform flow along a virtual plane extending in the vertical direction. Therefore, since occurrence of the circulating flow in the chamber  3  can be more reliably suppressed, the occurrence of the fumes P 1  and the spatters P 2  being caught in the circulating flow can be more satisfactorily suppressed. Accordingly, the fumes P 1  and the spatters P 2  caught in the circulating flow blocking the laser light L irradiated to the additive manufacturing article S can be more satisfactorily suppressed. 
     In the present embodiment, the blowing nozzle  40  includes the first blowing nozzle S 1  attached to the ceiling portion main body  21 , and the second blowing nozzle S 2  connected to the first blowing nozzle S 1  and extending downward from the first blowing nozzle S 1  to have the blowing part  4 . 
     Thereby, the additive manufacturing devices  1 C and  1 D having the blowing nozzle  40  can be obtained simply by attaching the second blowing nozzle S 2  to the first blowing nozzle S 1 . That is, in a case of an existing nozzle in which the first blowing nozzle S 1  has already been attached to the ceiling portion main body  21 , the additive manufacturing device  1 C having the blowing nozzle  40  can be obtained simply by additionally installing the second blowing nozzle. 
     Further, in the fourth embodiment, the width W 1   b  of the blowing port  5   b  in the second direction D 2  has been configured to be larger than the width W 1   a  of the blowing port  5   b  in the first direction D 1  and equal to or larger than the width W 2  of the additive manufacturing area  13  in the second direction D 2 , but the present disclosure is not limited thereto. 
     The width W 1   b  of the blowing port  5   b  in the second direction D 2  may be larger than the width W 1   a  of the blowing port  5   b  in the first direction D 1  and may be equal to or larger than a width W 4  of the additive manufacturing article S in the second direction D 2 . In this case, the same operation and effects as those of the second embodiment can be exhibited. 
     Also, the width W 1   a  of the blowing port  5   b  in the first direction D 1  may be smaller than a width W 5   a  of the laser irradiation window  22  in the first direction D 1 , and the width W 1   b  of the blowing port  5   b  in the second direction D 2  may be larger than a width W 5   b  of a first laser irradiation window  23  in the second direction D 2 . In this case, the same operation and effects as those of the third embodiment can be exhibited. 
     Further, in the fourth embodiment, the attachment opening  26  of the ceiling portion main body  21  and the introduction port  5   a  of the blowing nozzle  40  have been configured to be formed in a circular shape, but the present disclosure is not limited thereto, and may be formed in an elliptical shape. 
     Further, in the fourth embodiment, the blowing nozzle  40  has been configured to have the first blowing nozzle S 1 , but the present disclosure is not limited thereto and may be constituted only by the second blowing nozzle S 2 . In this case, the blowing nozzle  40  is attached in a form of being additionally installed in the additive manufacturing device which already has a nozzle (existing nozzle) for blowing out the inert gas G in the ceiling portion  20 . The blowing nozzle  40  is attached to an opening at a lower end of the existing nozzle. Alternatively, the blowing nozzle  40  constituted only by the second blowing nozzle S 2  may be attached to the attachment opening  26  of the ceiling portion main body  21  in place of the existing nozzle. 
     Fifth Embodiment 
     Hereinafter, an additive manufacturing device  1 D according to a fifth embodiment of the present disclosure will be described with reference to  FIGS.  11  and  12   . In the fifth embodiment, components the same as those in the first embodiment will be denoted by the same reference signs and detailed description thereof will be omitted. Configurations of the fifth embodiment other than those described below are the same as the configurations of the fourth embodiment. 
     As illustrated in  FIG.  11   , the additive manufacturing device  1 D includes a blowing nozzle  40  further having a rectifying member  50  (corresponding to a rectifying part in the claims) in addition to the blowing nozzle  40  of the fourth embodiment. The rectifying member  50  is provided inside a lower end portion  40   b  of the blowing nozzle  40 . For example, the rectifying member  50  is provided inside a flat part  43  of the blowing nozzle  40 . From another point of view, the rectifying member  50  is provided inside an outlet part  42  of the blowing nozzle  40 . For example, the rectifying member  50  is provided below a plurality of guide vanes  46  inside the outlet part  42  of the blowing nozzle  40 . 
     As illustrated in  FIG.  12   , the rectifying member  50  includes a plurality of rectifying tube parts  51  (corresponding to tube parts in the claims) therein. Cross-sectional shapes of the plurality of rectifying tube parts  51  are polygons (for example, regular hexagons) having the same size as each other. The plurality of rectifying tube parts  51  are disposed without gaps in a first direction D 1  and a second direction D 2 . 
     A length L 2  of the rectifying tube part  51  in a vertical direction is larger than, for example, a width W 1   a  of a blowing port  5   b  in the first direction D 1 . The length L 2  of the rectifying tube part  51  in the vertical direction is, for example, 5 mm or more. Also, from another point of view, the length of the rectifying tube part  51  in the vertical direction is three times or more a diagonal length of a regular hexagonal cross-sectional shape of the rectifying tube part  51 . 
     (Operation and Effects) 
     In the present embodiment, the additive manufacturing device  1 D includes a rectifying member  50  provided inside the blowing nozzle  40 . The rectifying member  50  includes the plurality of rectifying tube parts  51  extending in the vertical direction. 
     Thereby, among flow components of the inert gas G, components of the first direction D 1  and the second direction D 2  can be attenuated in the process of causing the inert gas G to flow in the rectifying tube parts  51 . Therefore, the inert gas G blown from a blowing part  4  diffusing in the first direction D 1  and the second direction D 2  can be further suppressed. Therefore, since a flow velocity of the inert gas G colliding with an additive manufacturing area  13  can be kept high, removal performance of fumes P 1  and spatters P 2  can be maintained. 
     Also, since components of the first direction D 1  and the second direction D 2  can be attenuated in the flow components of the inert gas G, a flow along the additive manufacturing area  13  is likely to be formed. Thereby, occurrence of a circulating flow in a chamber  3  can be more reliably suppressed. Therefore, the fumes P 1  and the spatters P 2  being caught in the circulating flow can be more satisfactorily suppressed. Accordingly, the fumes P 1  and the spatters P 2  caught in the circulating flow blocking laser light L irradiated to an additive manufacturing article S can be more satisfactorily suppressed. 
     Further, in the fifth embodiment, the rectifying member  50  has been configured to be provided in the blowing nozzle  40 , but the present disclosure is not limited thereto. For example, the rectifying member  50  may be directly connected to the blowing opening  25  of the first to third embodiments. 
     Further, in the fifth embodiment, the rectifying member  50  may be formed integrally with the blowing nozzle  40  or may be a separate member from the blowing nozzle  40 . If the rectifying member  50  is a separate member from the blowing nozzle  40 , the rectifying member  50  is fixed with an upper end portion thereof inserted into the blowing part  4  of the blowing nozzle  40 . 
     Further, in the fifth embodiment, the plurality of rectifying tube parts  51  have been configured to be disposed without gaps in the first direction D 1  and the second direction D 2 , but the present disclosure is not limited thereto, and the plurality of rectifying tube parts  51  may be disposed to be aligned in at least one of the first direction D 1  and the second direction D 2 . 
     Further, in the fifth embodiment, cross-sectional shapes of the plurality of rectifying tube parts  51  have been configured to be a regular hexagon, but the present disclosure is not limited thereto, and may be a regular triangle, a regular quadrangle, or the like. 
     Other Embodiments 
     While embodiments of the present disclosure have been described in detail as above with reference to the accompanying drawings, the specific configurations are not limited to the embodiments but may include design changes or the like without departing from the gist of the present disclosure. 
     Further, the material powder has been configured to be a metal in the above-described embodiments, but the present disclosure is not limited thereto, and may be a resin material. 
     Further, the second direction D 2  has been perpendicular to the first direction D 1  in the above-described embodiments, but the present disclosure is not limited thereto, and may intersect the first direction D 1 . For example, the angle between the first direction D 1  and the second direction D 2  may be slightly larger or smaller than 90 degrees. 
     Further, the bottom portion  10  has been configured to have the stage  12  in the above-described embodiments, but the present disclosure is not limited thereto. The bottom portion  10  may not have the stage  12 , and the additive manufacturing area  13  of the bottom portion  10  may be a plane that is not raised and lowered vertically. 
     In addition, in the above-described embodiments, the blowing part  4  has been configured to be formed in a rectangular shape extending in the second direction D 2  in a plan view, but the present disclosure is not limited thereto. For example, the blowing part  4  may be formed in an elliptical shape extending in the second direction D 2 . 
     Further, the laser irradiation window  22  has been configured to be provided at a central part of the ceiling portion main body  21  in the above-described embodiments, but the present disclosure is not limited thereto, and the laser irradiation window  22  may be disposed to be biased in the first direction D 1  or in the second direction D 2  of the ceiling portion main body  21 . 
     Further, four laser irradiation windows  22  have been provided in the above-described embodiments, but the present disclosure is not limited thereto, and only one laser irradiation window  22  may be provided. The number of laser irradiation windows  22  can be changed as appropriate. 
     Further, the laser irradiation window  22  has been formed in a disc shape in the above-described embodiments, but the present disclosure is not limited thereto. For example, the laser irradiation window  22  may be formed in a rectangular plate shape, and a shape of the laser irradiation window  22  is not limited. 
     &lt;Additional Statement&gt; 
     The additive manufacturing devices  1 ,  1 A,  1 B,  1 C and  1 D and the blowing nozzle  40  described in the embodiments are grasped, for example, as follows. 
     (1) Additive manufacturing devices  1 ,  1 C and  1 D according to a first aspect includes a bottom portion  10  having an additive manufacturing area  13  on which an additive manufacturing article S is additively manufactured, a ceiling portion  20  positioned above the bottom portion  10  and having a blowing part  4  for an inert gas G, a side portion  30  standing upward from a side end portion  11  of the bottom portion  10 , and a discharge port  33  of the inert gas G, in which under a condition where a first direction D 1  is oriented from the additive manufacturing area  13  toward the discharge port  33  in a direction parallel to the bottom portion  10  and a second direction D 2  is oriented across the first direction D 1  in the direction parallel to the bottom portion  10 , a first width W 1   b  of the blowing part  4  in the second direction D 2  is larger than a second width W 1   a  of the blowing part  4  in the first direction D 1  and is equal to or larger than a third width W 2  of the additive manufacturing area  13  in the second direction D 2 . 
     Thereby, in the blowing part  4 , a flow of the inert gas G can be made uniform in the second direction D 2  while being aligned in parallel. The flow of the inert gas G blown out from the blowing part  4  has a two-dimensional and uniform flow along a virtual plane extending in the vertical direction. Further, the inert gas G can be made to collide with the entire additive manufacturing area  13  in the second direction D 2 . The inert gas G that has collided with the additive manufacturing area  13  flows in the first direction D 1  along the additive manufacturing area  13  and is discharged from the discharge port  33 . The flow of the inert gas G along the additive manufacturing area  13  has a uniform flow. The fumes P 1  and the spatters P 2  can be discharged from the discharge port  33  by the flow of the inert gas G along the additive manufacturing area  13 . 
     (2) Additive manufacturing devices  1 ,  1 A,  1 B,  1 C and  1 D of a second aspect include a bottom portion  10  having an additive manufacturing area  13  on which an additive manufacturing article S is additively manufactured, a ceiling portion  20  positioned above the bottom portion  10  and having a blowing part  4  for an inert gas G, a side portion  30  standing upward from a side end portion  11  of the bottom portion  10 , and a discharge port  33  of the inert gas G, in which under a condition where a first direction D 1  is oriented from the additive manufacturing area  13  toward the discharge port  33  in a direction parallel to the bottom portion  10  and a second direction D 2  is oriented across the first direction D 1  in the direction parallel to the bottom portion  10 , a first width W 1   b  of the blowing part  4  in the second direction D 2  is larger than a second width W 1   a  of the blowing part  4  in the first direction D 1  and is equal to or larger than a third width W 2  of the additive manufacturing article S in the second direction D 2 . 
     Thereby, in the blowing part  4 , a flow of the inert gas G can be made uniform in the second direction D 2  while being aligned in parallel. The flow of the inert gas G blown out from the blowing part  4  has a two-dimensional and uniform flow along a virtual plane extending in the vertical direction. Further, the inert gas G can be made to collide with the entire of the additive manufacturing article S in the second direction D 2 . The inert gas G that has collided with the additive manufacturing article S flows in the first direction D 1  along the additive manufacturing area  13  and is discharged from a discharge port  33 . The flow of the inert gas G along the additive manufacturing area  13  has a uniform flow at least in the area that is actually used for additive manufacturing. The fumes P 1  and the spatters P 2  can be discharged from the discharge port  33  by the flow of the inert gas G along the additive manufacturing area  13 . 
     (3) Additive manufacturing devices  1 ,  1 A,  1 B,  1 C and  1 D of a third aspect include a bottom portion  10  having an additive manufacturing area  13  on which an additive manufacturing article S is additively manufactured, a ceiling portion  20  positioned above the bottom portion  10  and having a blowing part  4  for an inert gas G and a first laser irradiation window  23 , a side portion  30  standing upward from a side end portion  11  of the bottom portion  10 , and a discharge port  33  of the inert gas G, in which under a condition where a first direction D 1  is oriented from the additive manufacturing area  13  toward the discharge port  33  in a direction parallel to the bottom portion  10  and a second direction D 2  is oriented across the first direction D 1  in the direction parallel to the bottom portion  10 , a first width W 1   a  of the blowing part  4  in the first direction D 1  is smaller than a second width W 5   a  of the first laser irradiation window  23  in the first direction D 1 , and a width W 1   b  of the blowing part  4  in the second direction D 2  is larger than a third width W 5   b  of the first laser irradiation window  23  in the second direction D 2 . 
     Thereby, in the blowing part  4 , a flow of the inert gas G can be made uniform in the second direction D 2  while being aligned in parallel. The flow of the inert gas G blown out from the blowing part  4  has a two-dimensional and uniform flow along a virtual plane extending in the vertical direction. Further, since the inert gas G can be blown out from a wider range in the second direction D 2  than the width W 5   b  of the first laser irradiation window  23  in the second direction D 2 , the inert gas G can be made to collide with a wider range in the second direction D 2  than an area of the additive manufacturing area  13  that overlaps the first laser irradiation window  23 . The inert gas G that has collided with the additive manufacturing area  13  flows in the first direction D 1  along the additive manufacturing area  13  and is discharged from the discharge port  33 . The flow of the inert gas G along the additive manufacturing area  13  has a uniform flow at least in the area of the additive manufacturing area  13  that overlaps the first laser irradiation window  23 . The fumes P 1  and the spatters P 2  can be discharged from the discharge port  33  by the flow of the inert gas G along the additive manufacturing area  13 . 
     (4) Additive manufacturing devices  1 ,  1 A,  1 B,  1 C and  1 D of a fourth aspect are described in the additive manufacturing devices  1 ,  1 A,  1 B,  1 C and  1 D of the third aspect, in which the ceiling portion  20  may include a second laser irradiation window  24  in which at least part thereof is aligned with the first laser irradiation window  23  in the second direction D 2 , and the blowing part  4  may include a first portion  4   a  aligned with the first laser irradiation window  23  in the first direction D 1  and a second portion  4   b  aligned with the second laser irradiation window  24  in the first direction D 1  in a plan view of the additive manufacturing devices  1 ,  1 A,  1 B,  1 C and  1 D. 
     Thereby, the inert gas G can be blown out from a wide range corresponding to a region in which the first laser irradiation window  23  and the second laser irradiation window  24  are provided. Therefore, the inert gas G can be made to collide with a wide range of the additive manufacturing area  13  corresponding to the first laser irradiation window  23  and the second laser irradiation window  24 . 
     (5) Additive manufacturing devices  1 ,  1 A,  1 B,  1 C and  1 D of a fifth aspect are described in the additive manufacturing devices  1 ,  1 A,  1 B,  1 C and  1 D according to any one of the first to fourth aspects, in which at least one of the bottom portion  10 , the side portion  30 , a flow path member  34  provided separately from the bottom portion  10  and the side portion  30  may include the discharge port  33 . 
     (6) Additive manufacturing devices  1 ,  1 A and  1 B of a sixth aspect are described in the additive manufacturing devices  1 ,  1 A and  1 B according to any one of the first to fifth aspects, in which the ceiling portion  20  may include a ceiling portion main body  21  that partitions a space vertically, and the blowing part  4  may be an opening (blowing opening  25 ) provided in the ceiling portion main body  21 . 
     Thereby, the blowing part  4  can be formed by simple processing of simply forming the opening (blowing opening  25 ) in the ceiling portion main body  21 . 
     (7) Additive manufacturing devices  1 C and  1 D according to a seventh aspect are described in the additive manufacturing devices  1 C and  1 D according to any one of the first to fifth aspects, in which the ceiling portion  20  may include a ceiling portion main body  21  that partitions a space vertically and a blowing nozzle  40  extending downward from the ceiling portion main body  21 , and the blowing part  4  may be an opening (blowing port  5   b ) provided at a lower end portion of the blowing nozzle  40 . 
     Thereby, the additive manufacturing devices  1 C and  1 D including the blowing part  4  (the blowing port  5   b ) can be obtained by attaching the blowing nozzle  40  to the ceiling portion main body  21 . 
     (8) Additive manufacturing devices  1 C and  1 D of a eighth aspect are described in the additive manufacturing devices  1 C and  1 D of the seventh aspect, in which the blowing nozzle  40  may include a flat part  43  extending in the second direction D 2  at least at the lower end portion. 
     Thereby, a flow of the inert gas G can be reduced in the process of causing the inert gas G to flow in the flat part  43 . Therefore, the flow of the inert gas G blown out from the blowing port  5   b  can be more reliably made to have a two-dimensional and uniform flow along a virtual plane extending in the vertical direction. 
     (9) Additive manufacturing devices  1 C and  1 D of an ninth aspect are described in the additive manufacturing devices  1 C and  1 D of the seventh or eighth aspect, in which the blowing nozzle  40  may include an enlarged part  41  whose width in the second direction D 2  becomes larger as it proceeds downward and an outlet part  42  provided below the enlarged part  41  and extending downward with a constant width in the second direction D 2 , and the blowing part  4  may be provided at a lower end portion of the outlet part  42 . 
     Thereby, a flow of the inert gas G can be aligned in the vertical direction in the process of causing the inert gas G to flow in the outlet part  42 . Therefore, the inert gas G blown out from the blowing part  4  colliding with the side portion  30  to generate a circulating flow can be more reliably suppressed until it reaches the additive manufacturing area  13 . 
     (10) Additive manufacturing devices  1 C and  1 D of a tenth aspect are described in the additive manufacturing devices  1 C and  1 D according to any one of the seventh to ninth aspects, in which the blowing nozzle  40  may include a plurality of guide vanes  46  aligned in the second direction D 2  therein. 
     Thereby, the inert gas G can be uniformly dispersed in the second direction  2  in the process of causing the inert gas G to flow between the plurality of guide vanes  46 . Therefore, the flow of the inert gas G blown out from the blowing part  4  can be more reliably made to have a two-dimensional and uniform flow along a plane extending in the vertical direction. 
     (11) An additive manufacturing device  1 D according to a eleventh aspect is described in the additive manufacturing device  1 D according to any one of the seventh to tenth aspects, in which the blowing nozzle  40  may include a rectifying part (rectifying member  50 ), and the rectifying part may include a plurality of tube parts (rectifying tube parts  51 ) disposed to be aligned in at least one of the first direction D 1  and the second direction D 2  and each extending in the vertical direction. 
     Thereby, among flow components of the inert gas G, at least one component of the first direction D 1  and the second direction D 2  can be attenuated in the process of causing the inert gas G to flow in the rectifying tube parts  51 . Therefore, the inert gas G blown from the blowing part  4  diffusing in the first direction D 1  or the second direction D 2  can be further suppressed. 
     (12) Additive manufacturing devices  1 C and  1 D of an twelfth aspect are described in the additive manufacturing devices  1 C and  1 D according to any one of the seventh to eleventh aspect, in which the blowing nozzle  40  may include a first blowing nozzle S 1  attached to the ceiling portion main body  21 , and a second blowing nozzle S 2  connected to the first blowing nozzle S 1  and extending downward from the first blowing nozzle S 1  to have the blowing part  4 . 
     Thereby, the additive manufacturing devices  1 C and  1 D including the blowing nozzle  40  can be obtained simply by attaching the second blowing nozzle S 2  to the first blowing nozzle S 1 . 
     (13) A blowing nozzle  40  of a thirteenth aspect is attachable to the additive manufacturing devices  1 C and  1 D and includes a first end portion (upper end portion  40   a ) including an introduction part (introduction port  5   a ) of an inert gas G, and a second end portion (lower end portion  40   b ) positioned on a side opposite to the first end portion and including a blowing part  4  (blowing port  5   b ) for the inert gas, in which, under a condition where a first direction D 1  is oriented in a direction parallel to the second end portion and a second direction D 2  is oriented across the first direction D 1  in the direction parallel to the second end portion, the blowing nozzle  40  includes a flat part  43  extending in the second direction D 2  at least at the second end portion, and a first width W 1   b  of the blowing part  4  in the second direction D 2  is larger than a second width W 1   a  of the blowing part  4  in the first direction D 1 . 
     EXPLANATION OF REFERENCES 
     
         
         
           
               1 ,  1 A,  1 B,  1 C,  1 D Additive manufacturing device 
               2  Laser irradiation unit 
               3  Chamber 
               4  Blowing part 
               4   a  First portion 
               4   b  Second portion 
               5   a  Introduction port (introduction part) 
               5   b  Blowing port (opening) 
               10  Bottom portion 
               11  Side end portion 
               12  Stage 
               13  Additive manufacturing area 
               14  Use area 
               20  Ceiling portion 
               21  Ceiling portion main body 
               22  Laser irradiation window 
               23  First laser irradiation window 
               24  Second laser irradiation window 
               25  Blowing opening (opening) 
               26  Attachment opening 
               30  Side portion 
               31  First side portion 
               32  Second side portion 
               33  Discharge port 
               34  Flow path member 
               40  Blowing nozzle 
               40   a  Upper end portion (first end portion) 
               40   b  Lower end portion (second end portion) 
               41  Enlarged part 
               42  Outlet part 
               43  Flat part 
               43   a  First blowing nozzle main body 
               44  Flange 
               45  Second blowing nozzle main body (flat part main body) 
               46  Guide vane 
               47  Flange 
               50  Rectifying member (rectifying part) 
               51  Rectifying tube part (tube part) 
             D 1  First direction 
             D 2  Second direction 
             G Inert gas 
             L Laser light 
             L 1  Length of outlet part in vertical direction 
             L 2  Length of rectifying tube part in vertical direction 
             P 1  Fume 
             P 2  Spatter 
             S Additive manufacturing article 
             S 1  First blowing nozzle 
             S 2  Second blowing nozzle 
             W 1   a  Width of blowing part in first direction 
             W 1   b  Width of blowing part in second direction 
             W 2  Width of additive manufacturing area in second direction 
             W 3  Width of discharge port in second direction 
             W 4  Width of additive manufacturing article in second direction 
             W 5   a  Width of first laser irradiation window in first direction 
             W 5   b  Width of first laser irradiation window in second direction 
             W 6   a  Width of introduction part in first direction 
             W 6   b  Width of introduction part in second direction