Patent Publication Number: US-2022219398-A1

Title: Processing machine

Description:
TECHNICAL FIELD 
     The present invention relates to a processing machine. 
     BACKGROUND ART 
     In relation to a conventional processing machine, for example, WO 2011/49143 (PTL 1) discloses an apparatus manufacturing a three-dimensional shaped object by using a powder sintering lamination method. In the apparatus manufacturing a three-dimensional shaped object, a supply nozzle is provided on a wall surface of a chamber. A local gas flow is formed in the chamber by supplying a gas from the supply nozzle. As a result, at least a part of fume generated by powder sintering lamination is discharged to outside of the chamber accompanying the local gas flow. 
     In addition to the above disclosure, Japanese Patent Laying-Open No. 2012-224919 (PTL 2), Japanese Patent Laying-Open No. 2018-127710 (PTL 3), Japanese Patent Laying-Open No. 2016-107454 (PTL 4), and Japanese Patent Laying-Open No. 2016-153529 (PTL 5) are documents disclosing conventional processing machines. 
     CITATION LIST 
     Patent Literature 
     PTL 1: WO 2011/49143 
     PTL 2: Japanese Patent Laying-Open No. 2012-224919 
     PTL 3: Japanese Patent Laying-Open No. 2018-127710 
     PTL 4: Japanese Patent Laying-Open No. 2016-107454 
     PTL 5: Japanese Patent Laying-Open No. 2016-153529 
     SUMMARY OF INVENTION 
     Technical Problem 
     Examples of a method of performing additive manufacturing (AM) processing for a workpiece by a molten material include directed energy deposition (DED), selective laser melting (SLM), thermal spraying, and the like. Use of such methods generates particulates (fume) by the AM processing for the workpiece, and thus the particulates are required to be discharged from the processing area efficiently. 
     Meanwhile, in the apparatus manufacturing a three-dimensional shaped object disclosed in PTL 1, it is attempted to discharge fume by forming a local gas flow in the chamber and accompanying the fume with the gas flow. However, since the fume generated at a processing point of the powder sintering lamination is widely diffused in the chamber, it is difficult to efficiently discharge the fume by the local gas flow in the chamber. 
     Therefore, an object of the present invention is to solve the above problem, and to provide a processing machine capable of efficiently discharging particulates generated by additive manufacturing processing for a workpiece from a processing area. 
     Solution to Problem 
     A processing machine according to the present invention is a processing machine that performs additive manufacturing processing for a workpiece with a molten material. The processing machine includes a first cover having a first wall and a second wall that face each other in a horizontal direction and forming a processing area between the first wall and the second wall. The first wall is provided with a first opening allowing a gas to flow into the processing area. The processing machine further includes an induction flow generator that generates a gas flow flowing from below to upward along the second wall. The first cover is provided with a second opening allowing the gas to flow out from the processing area 
     The processing machine configured as described above can generate a gas flow flowing from below to upward along the second wall (hereinafter, referred to as “induction flow”) by the induction flow generator. As a result, a gas flow along the horizontal direction that the gas flowing into the processing area through the first opening flows from the first wall provided with the first opening toward the second wall through which the induction flow flows, and an upward gas flow that the gas flowing from the first wall toward the second wall flows from below to upward by being guided by the induction flow can be generated in the processing area. The particulates generated in the processing area due to the AM processing are carried by this gas flow and is discharged to outside through the second opening, and thus the particulates can be efficiently discharged. 
     The processing machine preferably further includes a second cover that forms an accommodation space and accommodates, in the accommodation space, a material powder supply device that supplies the material powder toward the processing area. The induction flow generator includes a first blower that supplies a gas from the accommodation space into the processing area, and a duct that feeds the gas supplied from the accommodation space into the processing area as a gas flow flowing from below to upward. 
     In the processing machine configured as described above, by operating the first blower, the particulates generated in the accommodation space can also be carried by the induction flow and discharged to outside. Therefore, the particulates can be discharged from both the processing area and the accommodation space with a simple configuration. 
     The processing machine preferably further includes a dust collector, a second blower that supplies a gas from the processing area to the dust collector through the second opening, and a control unit that controls the first blower and the second blower. The control unit operates the first blower and the second blower while the AM processing for the workpiece is performed, and operates the first blower and stops the second blower while the additional manufacturing processing for the workpiece is not performed and the material powder is refilled to the material powder supply device. 
     In the processing machine configured as described above, the first blower and the second blower are selectively operated in accordance with timing at which particulates are generated in each of the processing area and the accommodation space. This makes it possible to discharge the particulates from the processing area and the accommodation space while suppressing energy consumption in the blower. 
     The first cover preferably further includes a ceiling. The second opening is provided in the ceiling. 
     In the processing machine configured as described above, since the ceiling is located ahead of the induction flow flowing from below to upward, the particulates can be more efficiently discharged to outside through the second opening. 
     The induction flow generator preferably includes a duct having an outlet and feeding a gas into the processing area through the outlet. The outlet is provided at a position as high as the first opening or at a position lower than the first opening. 
     The processing machine configured as described above can allow the gas flowing from the first wall toward the second wall to collide with the induction flow more reliably. This facilitates generation of an upward gas flow flowing from below to upward, and thus the particulates can be more efficiently discharged to outside. 
     The processing machine preferably further includes a rectifying mechanism that is provided with the first opening and changes a gas flowing into the processing area into a gas flow along the horizontal direction. 
     In the processing machine configured as described above, since the gas flowing into the processing area through the first opening easily reaches the induction flow, the particulates can be more efficiently discharged to outside. 
     Advantageous Effects of Invention 
     As described above, in accordance with the present invention, it is possible to provide the processing machine capable of efficiently discharging particulates generated by the AM processing for a workpiece from the processing area. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a front view of a processing machine according to an embodiment of the present invention. 
         FIG. 2  is a perspective view of a duct of an induction flow generator in  FIG. 1 . 
         FIG. 3  is a perspective view illustrating a modification of a first opening in  FIG. 1 . 
         FIG. 4  is a block diagram related to control of a first blower and a second blower. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     An embodiment of the present invention will be described with reference to the drawings. In the drawings referred to below, the same or corresponding members are denoted by the same reference signs. 
       FIG. 1  is a front view of a processing machine according to the embodiment of the present invention.  FIG. 1  illustrates an inner side of the processing machine in transparent view of a front surface of a cover having appearance of the processing machine. 
     Referring to  FIG. 1 , a processing machine  10  is a processing machine capable of performing additive manufacturing (AM) processing for a workpiece with a molten material. The AM processing refers to a processing method of creating a three-dimensional shape on a workpiece by attaching a material, and a mass of the workpiece increases after the AM processing as compared with before the AM processing. 
     Processing machine  10  is a numerical control (NC) processing machine in which various operations for workpiece processing are automated by numerical control by a computer. 
     Processing machine  10  may be a processing machine capable of only the AM processing for a workpiece, or may be an AM/SM hybrid processing machine capable of the AM processing for a workpiece and subtractive manufacturing (SM) processing for a workpiece. 
     Processing machine  10  includes a first cover  21 , a processing head  14 , and a workpiece moving stage  12 . 
     First cover  21  forms a processing area  51  for performing the AM processing on a workpiece W. 
     Processing head  14  is provided in processing area  51 . A laser beam and a material powder are introduced into processing head  14 . Processing head  14  includes a nozzle for discharging the material powder and a laser beam irradiation device for irradiating workpiece W with the laser beam (not illustrated). Processing head  14  performs the AM processing on workpiece W by discharging the material powder and irradiating workpiece W with the laser light (directed energy deposition (DED)). Workpiece moving stage  12  is provided in processing area  51 . Workpiece moving stage  12  faces processing head  14  in a Z-axis direction parallel to a vertical direction. Workpiece moving stage  12  is provided below processing head  14 . Workpiece moving stage  12  has a placement surface  12   a . Placement surface  12   a  is formed of a plane (referred to as an “X-axis-Y-axis plane”) including an X-axis parallel to a horizontal direction and a Y-axis parallel to the horizontal direction and orthogonal to the X-axis. Workpiece W is placed on placement surface  12   a . Workpiece moving stage  12  is configured to be able to hold workpiece W placed on placement surface  12   a.    
     Workpiece moving stage  12  moves workpiece W in the X-axis-Y-axis plane by various feeding mechanisms, guide mechanisms, a servomotor, and the like. By moving workpiece moving stage  12 , a processing point of the AM processing on workpiece W can be moved. 
     In a configuration where processing head  14  irradiating workpiece W with the laser light and supplying the material powder, and workpiece moving stage  12  holding workpiece W are mutually moved, the processing point of the AM processing on workpiece W can be moved. For example, processing head  14  may move in air in processing area  51 , or this configuration may be combined with workpiece moving stage  12 . 
     Processing machine  10  further includes a second cover  61  and a material powder supply device  66 . 
     Second cover  61  is provided side by side with first cover  21 . Second cover  61  forms an accommodation space  56 . Processing area  51  and accommodation space  56  are arranged in an X-axis direction. 
     Material powder supply device  66  is accommodated in accommodation space  56 . Material powder supply device  66  supplies the material powder used for the AM processing toward processing head  14 . Material powder supply device  66  includes a material powder tank  67  and a mixer  68 . Material powder tank  67  has a tank shape and stores the material powder used for the AM processing. Mixer  68  is provided below material powder tank  67 . Mixer  68  is configured to be able to mix the material powder and carrier gas. 
     Material powder tank  67  is provided with a refill port (not illustrated) used for refilling the material powder into the tank. A height from a floor surface on which processing machine  10  is installed to the refill port may be, for example, greater than or equal to 1.2 m, or greater than or equal to 1.5 m. 
     In addition to material powder supply device  66 , a laser oscillator (not illustrated) that oscillates the laser beam used for the AM processing may be accommodated in accommodation space  56 . 
     First cover  21  includes a first wall  23 , a second wall  25 , and a ceiling  27 . First wall  23  and second wall  25  face each other in the X-axis direction. First wall  23  and second wall  25  are provided apart from each other in the X-axis direction. First wall  23  and second wall  25  have a flat plate shape parallel to a Y-axis-Z-axis plane. 
     Processing area  51  is formed between first wall  23  and second wall  25 . 
     Ceiling  27  is provided at a top of processing area  51 . Ceiling  27  is connected to an upper end of first wall  23  and an upper end of second wall  25 . 
     As a typical example, first cover  21  further includes an openable and closable door (not illustrated). The door is provided on a front surface of first cover  21  on a front side (transparent in  FIG. 1 ) on the sheet illustrating  FIG. 1 . The door is provided on the front surface of first cover  21 , different from first wall  23  and second wall  25 . The door is closed when processing head  14  is performing the AM processing on workpiece W, and the door is opened when a user needs to access processing area  51  to attach or detach workpiece W to or from workpiece moving stage  12 , or the like. 
     Second wall  25  is located between processing area  51  and accommodation space  56  in the X-axis direction. Processing area  51  and accommodation space  56  are separated by second wall  25 . 
     First wall  23  is provided with a first opening  31 . First opening  31  is an opening allowing air to flow into processing area  51 . First opening  31  is formed of a through hole penetrating first cover  21  (first wall  23 ). Processing area  51  and an external space (for example, an indoor space such as a factory where processing machine  10  is installed) outside processing area  51  communicate with each other through first opening  31 . 
     First opening  31  is provided at a position above and away from the floor surface on which processing machine  10  is installed. First opening  31  is provided at a position higher than placement surface  12   a  of workpiece moving stage  12  in the Z-axis direction (corresponding to a case where placement surface  12   a  is at a position lower than a lower end of an opening surface of first opening  31 ). 
     Without limited to the above configuration, first opening  31  may be provided at a position as high as placement surface  12   a  of workpiece moving stage  12  in the Z-axis direction (corresponding to a case where placement surface  12   a  is at a height between an upper end and the lower end of the opening surface of first opening  31 ). First opening  31  may be provided at a position lower than placement surface  12   a  of workpiece moving stage  12  in the Z-axis direction (corresponding to a case where placement surface  12   a  is at a position higher than the upper end of the opening surface of first opening  31 ). 
     First opening  31  may have another application (an application of discharging chips to outside of the machine, for example, in a case where processing machine  10  is an AM/SM hybrid processing machine) in addition to an application of allowing air to flow into processing area  51 . 
     First opening  31  may be provided with a blower allowing air to flow into processing area  51  forcibly. 
     First cover  21  is further provided with a second opening  33 . Second opening  33  is an opening allowing air to flow out from processing area  51 . Second opening  33  is formed of a through hole penetrating first cover  21 . 
     Second opening  33  is provided at a position higher than first opening  31  in the Z-axis direction. Second opening  33  is provided at a position higher than processing head  14  and workpiece moving stage  12  in the Z-axis direction. Second opening  33  is provided at a position apart from first wall  23  and second wall  25  in the X-axis direction. Second opening  33  is provided at a position closer to second wall  25  than first wall  23  in the X-axis direction (distance from second wall  25  to second opening  33  in the X-axis direction&lt;distance from first wall  23  to second opening  33  in the X-axis direction). 
     Second opening  33  is provided in ceiling  27 . Second opening  33  is formed of a through hole penetrating ceiling  27 . 
     An opening area of second opening  33  may be larger than an opening area of first opening  31 , or may be smaller than or equal to the opening area of first opening  31 . 
       FIG. 2  is a perspective view of a duct of an induction flow generator in  FIG. 1 . Referring to  FIGS. 1 and 2 , processing machine  10  further includes an induction flow generator  41 . Induction flow generator  41  is provided in second wall  25 . Induction flow generator  41  generates an air flow flowing from below to upward along second wall  25  in processing area  51 . 
     Induction flow generator  41  includes a first blower  46  and a duct  42 . First blower  46  allows air to flow into processing area  51  while operating. First blower  46  is attached to second wall  25 . While operating, first blower  46  allows air to flow from accommodation space  56  into processing area  51 . 
     Duct  42  has a duct shape and forms a flow path through which air flows. Duct  42  is provided in processing area  51 . Duct  42  is attached to second wall  25 . Duct  42  feeds the air supplied from first blower  46  into processing area  51  as an air flow flowing from below to upward. 
     Duct  42  includes an inlet  44 , an upstream portion  42 P, a reverse portion  42 R, a downstream portion  42 Q, and an outlet  43 . Inlet  44 , upstream portion  42 P, reverse portion  42 R, downstream portion  42 Q, and outlet  43  are provided side by side in that order from an upstream side to a downstream side of the air flow in duct  42 . 
     Inlet  44  is open at one end of duct  42 . Inlet  44  is overlapped with an opening  35  (see  FIG. 1 ) provided in second wall  25 . Accommodation space  56  and a space in duct  42  communicate with each other through opening  35  and inlet  44 . First blower  46  is connected to inlet  44 . 
     Inlet  44  is provided at a position higher than outlet  43  in the Z-axis direction. Inlet  44  is provided at a position higher than first opening  31  in the Z-axis direction. Inlet  44  is provided at a position lower than second opening  33  in the Z-axis direction. 
     Upstream portion  42 P extends in the Z-axis direction along second wall  25 . Upstream portion  42 P extends downward from inlet  44 . Upstream portion  42 P may have a tapered shape such that a flow path area of the air decreases downward. Reverse portion  42 R is connected to a lower end of upstream portion  42 P. Reverse portion  42 R is provided so as to be reversed by 180° from upstream portion  42 P while being curved in a direction toward first wall  23  in the X-axis direction. Downstream portion  42 Q is connected to an upper end of reverse portion  42 R. Downstream portion  42 Q extends upward from reverse portion  42 R. A length of downstream portion  42 Q in the Z-axis direction is smaller than a length of upstream portion  42 P in the Z-axis direction. 
     Outlet  43  is open at the other end of duct  42 . Outlet  43  is provided at an upper end of downstream portion  42 Q. 
     Outlet  43  is provided at a position lower than second opening  33 . An opening surface of outlet  43  faces an opening surface of second opening  33  in the Z-axis direction. 
     Outlet  43  may be provided at a position as high as first opening  31  in the Z-axis direction. This case corresponds to a case where the opening surface of outlet  43  is at a height between the upper end and the lower end of the opening surface of first opening  31  (in  FIG. 1 , Ha≤h≤Hb). Outlet  43  may be provided at a position lower than first opening  31  in the Z-axis direction. This case corresponds to a case where the opening surface of outlet  43  is at a position lower than the lower end of the opening surface of first opening  31  (in  FIG. 1 , h&lt;Ha). 
     Outlet  43  is preferably provided at a position overlapping first opening  31  in a Y-axis direction. 
     The air supplied from first blower  46  flows into duct  42  through inlet  44 . The air flowing into duct  42  flows from above to below through upstream portion  42 P. The air flow flowing from above to below is reversed to the air flow flowing from below to upward in reverse portion  42 R. After flowing from below to above in downstream portion  42 Q, the air is sent into processing area  51  as an air flow flowing from below to upward through outlet  43 . 
     Processing machine  10  further includes a dust collector  71 , a second blower  76 , and a dust collecting duct  72 . 
     Dust collector  71  is provided in the external space of processing area  51 . Dust collector  71  is connected to second opening  33  through dust collecting duct  72 . 
     While operating, second blower  76  supplies air from inside of processing area  51  to dust collector  71  through second opening  33 . Second blower  76  is incorporated in dust collector  71 . Second blower  76  may be provided in second opening  33  or may be provided on a path of dust collecting duct  72 . 
     Next, functions and effects provided by processing machine  10  according to the embodiment will be described. 
     At the processing point of workpiece W, the material powder changes into steam, the steam is cooled, and thus fume of fine particulate (for example, particles of less than or equal to 1 μm) is generated in processing area  51 . Further, when the material powder is refilled to material powder supply device  66  (material powder tank  67 ), the material powder (for example, powder of about 50 μm) may fly in accommodation space  56 . These particulates are required to be efficiently discharged from inside of processing area  51  or inside of accommodation space  56  for health reasons of the user or the like. 
     Therefore, in processing machine  10  according to the embodiment, the fume generated in processing area  51  and the material powder flying in accommodation space  56  are collected in dust collector  71  through dust collecting duct  72 . 
     Here, induction flow generator  41  generates an air flow flowing from below to upward along second wall  25  (an air flow (induction flow) indicated by an outlined arrow  210  in  FIG. 1 ) in processing area  51 . As a result, an air flow along the horizontal direction (an air flow indicated by arrow  220  in  FIG. 1 ) that the air flowing into processing area  51  through first opening  31  flows from first wall  23  provided with first opening  31  toward second wall  25  through which the induction flow (an air flow indicated by an arrow  230  in  FIG. 1 ) that the air flowing from first wall  23  toward second wall  25  flows from below to upward by being guided by the induction flow can be generated. 
     The fume generated at the processing point of workpiece W is collected near second wall  25  by the air flow along the horizontal direction from first wall  23  toward second wall  25 . The fume collected near second wall  25  is further discharged to outside of processing area  51  through second opening  33  by an upward air flow along second wall  25 . Therefore, the fume generated in processing area  50  due to the AM processing can be efficiently discharged to outside. 
     Second opening  33  is provided in ceiling  27 . In this configuration, the ceiling is located ahead of the upward air flow along second wall  25 , and thus the fume in processing area  51  can be more efficiently discharged through second opening  33 . 
     Further, in a case where outlet  43  is provided at a position as high as first opening  31  or at a position lower than first opening  31 , the air flow along the horizontal direction from first wall  23  toward second wall  25  can more reliably collide with the induction flow. As a result, an upward air flow along second wall  25  is likely to occur, and thus the fume in processing area  51  can be more efficiently discharged to outside. 
     Induction flow generator  41  generates the induction flow by allowing air to flow into processing area  51  from accommodation space  56  along with the operation of first blower  46 . Thus, the material powder flying in accommodation space  56  is also guided into processing area  51  through duct  42  and then discharged to outside by the induction flow fed from outlet  43 . As a result, not only the fume generated in processing area  51  but also the material powder flying in accommodation space  56  are discharged to outside by induction flow generator  41 , and thus a particulate discharge mechanism in processing machine  10  can have a simple configuration. 
       FIG. 3  is a perspective view illustrating a modification of the first opening in  FIG. 1 . Referring to  FIGS. 1 and 3 , in the modification, processing machine  10  further includes a rectifying mechanism  91 . Rectifying mechanism  91  is provided with first opening  31 . Rectifying mechanism  91  changes the air flowing into processing area  51  into an air flow along the horizontal direction. 
     Rectifying mechanism  91  includes a block body  92 . Block body  92  is provided with a plurality of first openings  31 . The plurality of first openings  31  is arranged in the vertical direction. The first openings  31  extend in a slit shape along the Y-axis direction. 
     In this configuration, the air flowing into processing area  51  through first opening  31  easily reaches the induction flow along second wall  25 , and thus the particulates can be more efficiently discharged to outside. 
       FIG. 4  is a block diagram related to control of the first blower and the second blower. Referring to  FIGS. 1 and 4 , processing machine  10  further includes a control unit  81 . Control unit  81  is a control panel that is provided in processing machine  10  and controls various operations in processing machine  10 . Control unit  81  controls first blower  46  and second blower  76 . 
     Control unit  81  includes a blow controller  82 , a storage  83 , and a processing controller  84 . Blow controller  82  controls operations of first blower  46  and second blower  76 . Storage  83  stores a processing program (numerical control program) created by the user of processing machine  10 . Processing controller  84  executes the processing program stored in storage  83  in accordance with an instruction from the user. 
     Blow controller  82  determines whether the AM processing for the workpiece is performed on the basis of the processing program executed in processing controller  84 . 
     Material powder supply device  66  further includes a refill detector  85 . Refill detector  85  detects refilling of the material powder to material powder supply device  66  (material powder tank  67 ). For example, refill detector  85  is provided at the refill port for the material powder in material powder tank  67 , and includes a sensor capable of detecting the material powder charged to the refill port. 
     An openable and closable lid member is provided in the refill port of material powder tank  67 . In this case, refill detector  85  may include a sensor capable of detecting that the lid member is opened. 
     Upon receipt of a signal from refill detector  85 , blow controller  82  determines whether material powder supply device  66  is refilled with the material powder. 
     Control unit  81  operates first blower  46  and second blower  76  while the AM processing for the workpiece is performed. Control unit  81  operates first blower  46  and second blower  76  regardless of whether the material powder is refilled to material powder supply device  66  while the AM processing for the workpiece is performed. 
     Control unit  81  operates first blower  46  and stops second blower  76  while the AM processing for the workpiece is not performed and the material powder is refilled to material powder supply device  66 . 
     While the AM processing for the workpiece is not performed and the material powder is refilled to material powder supply device  66 , only first blower  46  is operated to supply air from accommodation space  56  into processing area  51 , and thus the material powder flying in accommodation space  56  is fed into processing area  51 . When the AM processing for the workpiece is performed, the material powder flying in accommodation space  56  and the fume generated in processing area  51  are discharged to outside by operating both first blower  46  and second blower  76  discharge. This makes it possible to clean the atmosphere in accommodation space  56  and processing area  51  at an appropriate timing and suppress energy consumption in the blowers. 
     To summarize a structure of processing machine  10  according to the embodiment of the present invention described above, processing machine  10  according to the embodiment is a processing machine that performs the AM processing for a workpiece with a molten material. Processing machine  10  includes first cover  21  having first wall  23  and second wall  25  that face each other in the horizontal direction and forming processing area  51  between first wall  23  and second wall  25 . First wall  23  is provided with first opening  31  allowing air as a gas to flow into processing area  51 . Processing machine  10  further includes induction flow generator  41  that generates an air flow flowing from below to upward along second wall  25 . First cover  21  is provided with second opening  33  that allows air to flow out from processing area  51 . 
     Processing machine  10  according to the embodiment of the present invention configured as described above can efficiently discharge particulates (fume) generated due to the AM processing for the workpiece from processing area  51 . 
     The AM processing performed by the processing machine of the present invention may adopt, for example, a directional energy deposition method in which a wire is fed to a workpiece instead of the material powder in the embodiment. The AM processing performed by the processing machine of the present invention may adopt a selective laser melting method or thermal spraying. 
     It should be understood that the embodiment disclosed herein is illustrative in all respects and not restrictive. The scope of the present invention is defined not by the above description but by the claims, and is intended to include meanings equivalent to the claims and all modifications within the scope. 
     INDUSTRIAL APPLICABILITY 
     The present invention is applied to a processing machine that performs additive manufacturing processing. 
     REFERENCE SIGNS LIST 
       10 : processing machine,  12 : workpiece moving stage,  12   a : placement surface,  14 : processing head,  21 : first cover,  23 : first wall,  25 : second wall,  27 : ceiling,  31 : first opening,  33 : second opening,  41 : induction flow generator,  42 : duct,  42   p : upstream portion,  42   q : downstream portion,  42   r : reverse portion,  43 : outlet,  44 : inlet,  46 : first blower,  51 : processing area,  56 : accommodation space,  61 : second cover.  66 : material powder supply device,  67 : material powder tank,  68 : mixer,  71 : dust collector,  72 : dust collecting duct,  76 : second blower,  81 : control unit,  82 : blow controller,  83 : storage,  84 : processing controller,  85 : refill detector,  91 : rectifying mechanism,  92 : block body