JP2019081937A - Powder saving device and powder saving method - Google Patents

Abstract

To provide a powder saving device and a powder saving method that can save powder, by a simple structure, when molding a small-sized molding compared to the size of a molding tank.SOLUTION: A powder saving device 100 has a regulation plate 41 that is installed above a lifting table 35 and has an opening formed therein, where the regulation plate 41 accepts powder A only through the opening and regulates the amount of the powder A supplied to a molding tank 36, and a heating part 47,48 that heats the powder A so as to form a temporarily sintered body 50 in which the powder A is temporarily sintered along a peripheral wall 41c of the opening of the regulation plate 41.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a powder saving device and a powder saving method applied to a three-dimensional additive manufacturing apparatus.

  There is known an apparatus for forming a three-dimensional laminated object by irradiating a powder with an electron beam or a laser beam or the like. In the apparatus described in Patent Document 1, powder is supplied within the range of the opening of the second table placed on the first table. A melting wall is formed by scanning the electron beam along the opening of the second table to melt the powder. In the apparatus described in Patent Document 2, in addition to a three-dimensional object, a support wall is formed around the object in the laser sintering process. In the device described in Patent Document 3, in the area defined by the platen and the forming tank (the forming tank), a falling prevention wall for preventing the powder from falling is provided. In the apparatus described in Patent Document 4, a second powder material container is set in a first powder material container. The second powder material container defines a storage area that is smaller than the storage area of the first powder material container.

Unexamined-Japanese-Patent No. 2010-261072 JP, 2011-251529, A Unexamined-Japanese-Patent No. 2017-088947 Japanese Patent Application Publication No. 2007-30303

  In the devices described in Patent Documents 1 to 4 described above, the amount of powder supplied is adjusted in accordance with the size of the shaped object. However, in the apparatuses described in Patent Documents 1 and 2, since the melting wall and the supporting wall are formed, the powder material required for these walls is discarded, and eventually it is wasted. In addition, as in the device described in Patent Document 1, when a molten wall is formed in the opening of the table, the molten wall can be fixed or fused to the table by the heat input, so it is difficult to descend the powder bed. It becomes. The devices described in Patent Documents 3 and 4 require a separate wall or container, which complicates the configuration.

  An object of the present invention is to provide a powder saving device and a powder saving method capable of saving powder with a simple configuration when forming a small sized object relative to the size of a forming tank. .

  One aspect of the present invention is a shaping tank in which a shaped object obtained by melting powder is shaped, a shaping table provided in the shaping tank and relatively moving in the axial direction of the shaping tank with respect to the shaping tank A powder saving device applied to a three-dimensional additive manufacturing apparatus comprising: a restricting plate installed above a forming table and having an opening formed therein, which receives powder only through the opening and is supplied to a forming tank And a heating unit that heats the powder so as to form a temporary sintered body in which the powder is temporarily sintered along the peripheral wall surface of the opening of the restriction plate.

  According to the powder saving device, the formation is performed on the formation table which is provided in the formation tank and relatively moves in the axial direction. The powder is received only through the opening of the restricting plate located above the shaping table. Since a limited amount of powder is supplied to the build tank, powder is saved when molding small sized objects relative to the size of the build tank. The temporary sintered body is formed along the peripheral wall surface of the opening of the regulating plate by the heating unit. The temporary sintered body is a cylinder extending in the axial direction with a cross section corresponding to the opening. The temporary sintered body formed into a tubular shape accommodates the shaped object inside, and prevents the powder from leaking out to the outside (the space between the temporary sintered body and the side wall portion of the forming tank). Moreover, since the temporary sintered body is made of powder in a state of not reaching melting, it is difficult to adhere to the peripheral wall surface of the opening. In addition, the pre-sintered body can be reused as a powder by being crushed in a later step, and is not wasted. Therefore, it is possible to model the shaped object without any trouble (without causing sticking or the like) with only the amount of the raw material corresponding to the volume of the shaped object. According to the powder saving device, it is not necessary to largely change the configuration of the existing three-dimensional layered manufacturing device, and the powder can be saved by a simple configuration including the regulation plate and the heating unit.

  In some embodiments, a buffer portion is provided on the peripheral wall surface of the opening of the restriction plate so as to be interposed between the temporary sintered body and the peripheral wall surface. In this case, the buffer portion reliably prevents the temporary sintered body from adhering to the peripheral wall surface of the opening of the regulating plate. As a result, when the shaping plate relatively moves in the axial direction, the shaped object and the temporary sintered body can move smoothly with respect to the regulating plate.

  In some embodiments, the heating unit is configured to heat the powder through the restriction plate. In this case, the temporary sintered body can be easily formed along the peripheral wall surface of the opening of the restriction plate.

  According to another aspect of the present invention, there is provided a powder saving method comprising: a forming tank in which a shaped object obtained by melting the powder is formed; and an axial direction of the forming tank relative to the forming tank provided in the forming tank. A powder saving method applied to a three-dimensional additive manufacturing apparatus provided with a forming table moving to the upper side, the receiving process receiving powder only through the opening of the restriction plate installed above the forming table, and receiving in the receiving process Heating the powder so as to form a temporary sintered body in which the powder is temporarily sintered along the peripheral wall surface of the opening of the regulating plate while melting the powder. According to this powder saving method, the same operation and effect as the above-described powder saving device can be obtained.

  According to some aspects of the present invention, powder can be saved with a simple configuration when forming a small sized object relative to the size of the forming tank.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows schematic structure of the three-dimensional lamination forming apparatus with which the powder saving device which concerns on embodiment of this invention was applied. In a powder saving device, it is a sectional view showing a state where a modeling process is carried out. In a powder saving device, it is a sectional view showing the state where the modeling process ended. It is a top view which shows the powder supplied in the powder saving device which concerns on a modification. FIG. 5 (a) is a view corresponding to FIG. 4 as viewed from the X direction, and FIG. 5 (b) is a view as viewed from the X direction of the powder supplied in the powder saving device according to another modification. . FIG. 6 (a) shows an example of preheating and temporary sintering, and FIG. 6 (b) shows another example of preheating and temporary sintering.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the description of the drawings, the same elements will be denoted by the same reference symbols and redundant description will be omitted.

  First, with reference to FIG. 1, the basic configuration of the three-dimensional layered manufacturing apparatus 1 of the present embodiment will be described. The three-dimensional layered manufacturing apparatus 1 is an apparatus that irradiates the powder A on the modeling surface S with an electron beam B to melt and solidify the powder A to form a three-dimensional object. The three-dimensional additive manufacturing apparatus 1 includes an electron beam emitting unit 2, a forming unit 3, and a control unit 4.

  The electron beam emitting unit 2 emits the electron beam B toward the powder A on the modeling surface S of the modeling unit 3 to melt the powder A. The electron beam emitting unit 2 may perform preheating of the powder A by irradiating the powder A with the electron beam B before forming an object.

  The electron beam emitting unit 2 includes an electron gun unit 21, an aberration coil 22, a focus coil 23, and a deflection coil 24. The electron gun unit 21 is electrically connected to the control unit 4, operates in response to a control signal from the control unit 4, and emits an electron beam B. The electron gun unit 21 is provided, for example, to emit the electron beam B downward. The aberration coil 22 is electrically connected to the control unit 4 and operates in response to a control signal from the control unit 4. The aberration coil 22 is disposed around the electron beam B emitted from the electron gun unit 21 and corrects the aberration of the electron beam B. The focus coil 23 is electrically connected to the control unit 4 and operates in response to a control signal from the control unit 4. The focus coil 23 is disposed around the electron beam B emitted from the electron gun unit 21 to converge the electron beam B and adjust the focus state at the irradiation position of the electron beam B. The deflection coil 24 is electrically connected to the control unit 4 and operates in response to a control signal from the control unit 4. The deflection coil 24 is disposed around the electron beam B emitted from the electron gun unit 21 and adjusts the irradiation position of the electron beam B according to the control signal. The electron gun unit 21, the aberration coil 22, the focus coil 23, and the deflection coil 24 are installed, for example, in a cylindrical column 26. The aberration coil 22 may be omitted.

  The forming unit 3 is a portion for forming a desired object C, which is a desired object. In the chamber 30, the modeling unit 3 has a work bench 39 (see FIG. 2), a modeling tank 36, a plate 31 and an elevating table 35 (modeling table) provided in the modeling tank 36, and an elevating device 10. Two powder feeding devices 40 and a coating mechanism 33 are provided. The inside of the chamber 30 is in a vacuum state.

  As shown in FIGS. 1 and 2, the workbench 39 is disposed below the powder supply device 40 and has a horizontal flat upper surface 39a on which the powder A supplied by the powder supply device 40 is placed. For example, a rectangular opening 39 c is provided on the work table 39, and a square tubular shaped tank 36 is fitted in the opening 39 c. The modeling tank 36 has an axis extending in the vertical direction (the Z direction in the drawing). The upper end surface 36 a of the side wall portion 36 b of the modeling tank 36 is lower than the upper surface 39 a of the work table 39 by a predetermined height, for example.

  The plate 31 is also referred to as a bottom plate or a base plate, and is a flat member disposed in the modeling tank 36. The plate 31 has, for example, a rectangular shape. The shape of the plate 31 corresponds to the shape of the modeling surface S. The plate 31 has a diameter smaller than the inner diameter of the build tank 36. The plate 31 is disposed on an extension of the emission direction of the electron beam B, and is provided, for example, parallel to the horizontal XY plane. The plate 31 and the formation tank 36 are arranged concentrically.

  The lifting device 10 supports the plate 31 and lifts and lowers the lifting table 35 and the plate 31 in the modeling tank 36 in the vertical direction. The lifting device 10 is installed below the plate 31 and has a lifting table 35 for supporting the plate 31 and an elevator 32 for lifting the plate 31 and the lifting table 35. The elevator 32 is electrically connected to the control unit 4 and operates in response to a control signal from the control unit 4. The elevator 32 moves the lift table 35 and the plate 31 upward at the initial stage of shaping of the object C, and lowers the lift table 35 and the plate 31 each time the powder A is melted and solidified on the plate 31 and stacked. On the plate 31, a shaped object C in which the powder A is melted is shaped. A shaped surface S is formed on the upper surface of the shaped object C. The shaped surface S has the same outer shape as the plate 31. The melt-formed surface formed by melting and solidifying the powder A descends as the plate 31 descends. A new (next layer) shaped surface S is formed on the melt shaped surface which has descended downward. In the working table 39, the plate 31, and the lifting device 10 configured as described above, the modeling surface S is exposed to the side of the working table 39 at the position of the opening 39c. The specific configurations of the elevator 10 and the elevator 32 are not limited to the above-described configurations, and may be other known configurations.

  While the formation of the object C is performed, the lifting table 35 and the plate 31 integrally descend in the formation tank 36. That is, the elevating table 35 and the plate 31 are configured to move relative to the modeling tank 36 in the axial direction (Z direction) of the modeling tank 36.

  The modeling tank 36 accommodates the modeling object C being modeled on the plate 31 and the powder A which is not melted. The modeling tank 36 is formed, for example, in a square tube shape, and extends in the moving direction of the plate 31. The shaped tank 36 is formed in a rectangular cross section concentric with the plate 31. As shown in FIG. 2, the lifting table 35 is formed in accordance with the inner surface shape of the shaping tank 36, that is, the side wall portion 36 b. In the case where the inner shape of the formation tank 36 is a horizontal cross section and is rectangular, the outer shape of the lifting table 35 is also rectangular. Thereby, it is suppressed that the powder A supplied to the modeling tank 36 leaks below the raising / lowering table 35. As shown in FIG. In addition, in order to suppress that the powder A leaks to the downward direction of the raising and lowering table 35, a sealing material may be provided in the outer edge part of the raising and lowering table 35. The shape of the formation tank 36 is not limited to a square cylinder, and may be a cylinder having a circular cross section.

  The shapes of the plate 31, the formation tank 36, and the formation surface S described above can be appropriately changed according to the shape of the formation C and the like. In the present embodiment, the case where the plate 31 and the modeling surface S are quadrangular and the modeling tank 36 has a rectangular tube shape will be described, but other shapes may be adopted. Since the plate 31 is disposed in the formation tank 36 and the formation surface S is formed on the plate 31, in plan view, they have the same shape and size.

  Two powder feeders 40 are symmetrically installed with respect to the central portion of the work table 39 provided with the plate 31, the shaping tank 36, and the shaping surface S. Each powder feeder 40 comprises a hopper (or tank) 34 for containing the powder A. Below the hopper 34, a cylindrical roller 43 for dropping the powder A with a predetermined supply amount is provided. At the lower part of the hopper 34, an outlet for discharging the powder A is formed, and the powder A is supplied to the roller 43 from this outlet. The discharge port is formed to cover substantially the entire roller 43, and the powder A is supplied from the hopper 34 to the entire length direction (axial direction) of the roller 43.

  The roller 43 has a rotational axis extending in the horizontal Y direction, and is rotatable around this rotational axis. The length of the roller 43 is larger than the length in the Y direction of the shaped surface S (that is, the plate 31). The length of the roller 43 may be substantially the same as the length in the Y direction of the shaped surface S (that is, the plate 31). The roller 43 is provided with a drive motor 43a. The drive motor 43 a is electrically connected to the control unit 4 and operates in response to a control signal from the control unit 4. The roller 43 is rotated by a predetermined rotation angle (or the number of rotations) by the drive motor 43 a being controlled by the control unit 4. The powder A is dropped with a predetermined supply amount in accordance with the rotation angle (or the number of rotations) of the roller 43. The dropped powder A is deposited on the upper surface 39 a of the work table 39 provided below the roller 43 to be deposited powder Aa. The deposited powder Aa is formed in a range including the shaped surface S (a range larger than the shaped surface S) in the Y direction.

  Powder A is composed of a large number of powder bodies. As powder A, for example, metal powder is used. Moreover, as powder A, as long as it can be melted and solidified by irradiation of electron beam B, granules having a larger particle size than powder may be used.

  The application mechanism 33 is a member that moves the deposited powder Aa onto the modeling surface S, supplies the powder A onto the modeling surface S, and levels the powder A. The application mechanism 33 is a member elongated in the horizontal Y direction. The length of the application mechanism 33 is larger than the length in the Y direction of the shaped surface S (that is, the plate 31). When the application mechanism 33 is positioned on the modeling surface S, the coating mechanism 33 is provided to cover the entire modeling surface S in the Y direction (see FIG. 4). The cross-sectional shape of the application mechanism 33 may be rectangular as shown in the figure, or may be another shape.

  The application mechanism 33 is movable in the horizontal X direction from the upper surface 39 a of the work bench 39 toward the modeling surface S. More specifically, the coating mechanism 33 is reciprocally movable along the X direction so as to cross the modeling surface S. The application mechanism 33 maintains a predetermined distance from the upper surface 39a and the modeling surface S while moving on the upper surface 39a and the modeling surface S. The application mechanism 33 is moved by an actuator or the like (not shown). The application mechanism 33 operates in response to a control signal from the control unit 4.

  The control unit 4 is an electronic control unit that controls the entire apparatus of the three-dimensional additive manufacturing apparatus 1. Control unit 4 includes a computer including hardware such as central processing unit (CPU), read only memory (ROM) and random access memory (RAM), and software such as a program stored in ROM. It consists of The control unit 4 executes elevation control of the plate 31, operation control of the coating mechanism 33, emission control of the electron beam B, operation control of the deflection coil 24, and the like. The control unit 4 outputs a control signal to the elevator 32 to operate the elevator 32 as lift control of the plate 31 to adjust the position of the plate 31 in the vertical direction. As the operation control of the coating mechanism 33, the control unit 4 operates the coating mechanism 33 before the emission of the electron beam B to level the powder A on the plate 31. The control unit 4 outputs a control signal to the electron gun unit 21 as emission control of the electron beam B, and causes the electron gun unit 21 to emit the electron beam B.

  The control unit 4 outputs a control signal to the deflection coil 24 to control the irradiation position of the electron beam B as operation control of the deflection coil 24. For example, three-dimensional CAD (Computer-Aided Design) data of the object C, which is an object to be formed, is input to the control unit 4. The control unit 4 generates two-dimensional slice data based on the three-dimensional CAD data. The slice data is, for example, data of a horizontal cross section of the object C, and is a collection of many data according to the upper and lower positions. Based on the slice data, a region where the electron beam B irradiates the powder A on the modeling surface S is determined, and a control signal is output to the deflection coil 24 according to the region.

  The basic configuration of the three-dimensional layered manufacturing apparatus 1 has been described above. However, the powder saving apparatus 100 is applied to the three-dimensional layered manufacturing apparatus 1. The powder saving device 100 is used when forming a small sized object C with respect to the size of the forming tank 36. In the conventional three-dimensional additive manufacturing system in which the powder bed system is adopted, the forming tank 36 is filled with the powder A regardless of the size of the formed object. Therefore, a large amount of expensive powder A will always be prepared, and the cost will increase in small-scale trial manufacture and trial molding with new materials. The powder saving device 100 is a device for addressing such a problem. In the powder saving device 100, when forming a small sized object C, the powder A can be saved with a simple configuration in which a minimum number of members and devices are added to the three-dimensional additive manufacturing device 1.

  Hereinafter, the powder saving device 100 will be described in detail. As described above, the three-dimensional additive manufacturing apparatus 1 includes: the forming tank 36 in which the object C is formed; and the elevating table 35 relatively moving in the vertical direction (Z direction) with respect to the forming tank 36 Have. As shown in FIGS. 1 and 2, the powder saving device 100 includes, for example, a restriction plate 41 having a rectangular opening 41 e at the center thereof. As shown in FIG. 2, the restriction plate 41 is placed, for example, on the upper end surface 36 a of the shaping tank 36. In other words, the outer shape of the regulating plate 41 corresponds to the opening 39c of the work table 39, and the regulating plate 41 is fitted into the opening 39c. The regulating plate 41 has a thickness equal to the difference in height between the upper surface 39 a of the work table 39 and the upper end surface 36 a of the shaping tank 36. Thus, the upper surface 41 a of the restriction plate 41 is flush with the upper surface 39 a of the work table 39 in a state in which the restriction plate 41 is inserted. A spacer or the like for finely adjusting the height of one or more sheets may be provided between the regulating plate 41 and the upper end surface 36a. The regulating plate 41 is disposed above the elevating table 35, and receives the powder A only through the opening 41e. That is, the regulating plate 41 regulates the amount of the powder A supplied to the modeling tank 36.

  The shape and size of the opening 41 e of the restricting plate 41 may be changed according to the shape and size of the object C. That is, the powder saving device 100 may be provided with a plurality of types of restriction plates 41. The opening 41 e has a shape and size including the shape of the horizontal cross section (that is, the cross section cut in the XY plane) of the shaped object C at any height of the shaped object C. In other words, in the case of considering the virtual object C, the opening 41 e is formed to allow passage of the object C in the Z direction.

  When the lifting table 35 and the plate 31 are at the top at the beginning of the formation of the shaped object C, the plate 31 is fitted in the opening 41 e of the regulating plate 41. That is, the outer shape of the plate 31 is substantially the same as the opening 41 e of the regulating plate 41 or slightly smaller than the opening 41 e. Then, the restriction plate 41 forms a small-sized shaped surface S corresponding to the shape of the plate 31. A region on the back surface 41 b side of the regulating plate 41 in the modeling tank 36 is a void G having a donut-shaped cross section, and the powder A does not flow into the void G. Thereby, the waste of the powder A is saved.

  The powder saving apparatus 100 heats the plurality of lamps A so as to temporarily sinter the powder A along the inner peripheral wall surface (peripheral wall surface) 41c of the opening 41e of the regulation plate 41 to form the temporary sintered body 50. A heater (heating unit) 47 and one or more heaters (heating unit) 48 are provided. The lamp heater 47 is, for example, a halogen lamp, and is turned on by receiving a current from a power supply (not shown). The plurality of lamp heaters 47 are installed, for example, right above the peripheral portion so as to heat the peripheral portion of the small-sized shaped surface S formed by the restriction plate 41. For example, four lamp heaters 47 may be provided on each side of the rectangular shaped surface S. The number of lamp heaters 47 may be five or more. The heater 48 can be, for example, a mode including a power supply and a heating wire. The heater 48 is connected to the regulating plate 41 to heat the regulating plate 41. The heater 48 may be configured to include a housing attached to the back surface 41 b of the restriction plate 41 and a heating element such as a heating wire accommodated in the housing. The heater 48 may be incorporated in the regulation plate 41. As the lamp heater 47 and / or the heater 48, known heating means other than the heating wire may be used. The lamp heater 47 and the heater 48 are electrically connected to the control unit 4.

  The regulating plate 41 is provided with a temperature sensor 46 that measures the temperature of the regulating plate 41 (for example, the temperature of the upper surface 41 a). The temperature sensor 46 is electrically connected to the control unit 4. The temperature sensor 46 measures the temperature of the regulating plate 41 and outputs the temperature information to the control unit 4.

  The lamp heater 47 and the heater 48 are on / off controlled by the control unit 4, for example, and heat the powder A and the regulation plate 41 in the vicinity of the inner circumferential wall surface 41c so that the temperature of the regulation plate 41 becomes a predetermined set temperature. Note that the lamp heater 47 and the heater 48 may be simply turned on during the shaping process, regardless of the control by the control unit 4. Alternatively, only one of the lamp heater 47 and the heater 48 may be used as a heating unit. When only the lamp heater 47 is used, the temperature sensor 46 may measure the temperature in the vicinity of the inner circumferential wall surface 41c.

  The heating by the lamp heater 47 and the heater 48 temporarily sinters the powder A in the vicinity of the inner circumferential wall surface 41 c. Pre-sintering is a state in which powders A are diffused and joined at the minimum point by the diffusion phenomenon. The temperature of the powder A in the vicinity of the inner peripheral wall surface 41 c is preferably set to a temperature equal to or more than half of the melting point of the material of the powder A. This is based on the fact that the diffusion phenomenon of sintering becomes active generally at half or more of the melting point. For example, when the material is titanium, the temperature for pre-sintering powder A is 700 to 800 ° C. (melting point of titanium alloy is about 1500 ° C. to 1600 ° C.). When the material is aluminum, the temperature for presintering powder A is about 300 ° C. (melting point of aluminum alloy is about 600 ° C.).

  While the shaped object C is shaped as the shaping tank 36 descends, a rectangular cylindrical temporary sintered body 50 is formed along the inner peripheral wall surface 41 c. The temporary sintered body 50 prevents the powder A from leaking to the outside (the air gap G described above). As the elevating table 35 descends, the surface 50 a of the temporary sintered body 50 may be in sliding contact with the inner peripheral wall surface 41 c of the regulating plate 41. The temporary sintered body 50 is in a state in which the powder A is not yet melted and is only temporarily sintered, and the time for which the powder A is in contact with each other is also short, so it does not adhere to the inner peripheral wall surface 41c.

  As shown in FIG. 2, a buffer portion 42 may be provided on the inner peripheral wall surface 41 c of the opening 41 e of the regulating plate 41 so as to be interposed between the temporary sintered body 50 and the inner peripheral wall surface 41 c. . More specifically, the buffer portion 42 may be a coating portion provided on the inner circumferential wall surface 41 c. In this case, the coating part is made of, for example, a ceramic coating. Alternatively, the buffer 42 may be a fireproof cloth. In this case, the refractory cloth is provided from the upper surface 41 a of the regulating plate 41 to the inner circumferential wall surface 41 c and is fixed to the regulating plate 41. For example, when the material of the powder A is a material that easily adheres to the regulation plate 41, the buffer portion 42 can prevent the powder A (the temporary sintered body 50) from adhering to the inner peripheral wall surface 41c. .

  Next, a powder saving method using the powder saving device 100 will be described. The powder saving method using the powder saving device 100 is not largely different from the ordinary lamination molding method in the three-dimensional lamination molding apparatus 1, but in terms of using the restriction plate 41 and heating by the lamp heater 47 and the heater 48. It is different.

  First, the powder A is supplied onto the upper surface 39 a of the work table 39 by the powder supply device 40, and the powder A is applied to the modeling surface S by the application mechanism 33. The shaped surface S has a smaller quadrangle than the shaped tank 36 by the small regulation plate 41 and the plate 31. That is, the powder A is received only through the opening 41 e of the regulation plate 41 installed above the elevating table 35 (reception step).

  Here, as shown in FIG. 4 and FIG. 5A, the spacer 44 is installed inside the hopper 34 so that the powder A (deposited powder Aa) supplied to the small-sized shaped surface S is also minimized. It may be done. Both ends of the Y-direction region of the hopper 34 are occupied by the spacers 44, whereby only the powder A having a limited width in the Y-direction drops from the discharge end 34a of the hopper 34. As shown in FIG. 4, the deposited powder Aa is larger than the small-sized shaped surface S in the Y direction, but smaller than the opening 39 c and the shaped tank 36. Thus, the powder saving mechanism may be provided on the powder supply device 40 side.

  Subsequently, the electron beam B is irradiated to the powder A of the modeling surface S by the electron beam emitting unit 2 shown in FIG. 1, and preheating of the powder A is performed. The preheating of powder A may be performed in two stages. That is, after the electron beam B is irradiated on the entire surface of the modeling surface S so that the powder A is heated to a relatively low temperature (first preheating step), the region of the object C and the region in the vicinity thereof are The electron beam B is irradiated so that the powder A is heated to a relatively high temperature (second preheating step). This relatively high temperature may be, for example, the temperature at which the powder A is temporarily sintered as described above. Furthermore, main melting based on the slice data of the three-dimensional object C is performed on the shaped surface S (main melting step). This produces shaping in that layer.

  Subsequently, the lifting table 35 and the plate 31 are sequentially lowered, and the above-described receiving process and formation in each layer are performed. While the series of forming processes are performed, the powder A and the regulation plate 41 in the vicinity of the inner circumferential wall surface 41c of the regulation plate 41 are heated by the lamp heater 47 and the heater 48, and the sintered body is temporarily sintered along the inner circumferential wall surface 41c. 50 are formed. That is, while melting powder A received in the receiving step, powder is formed so as to form temporary sintered body 50 in which powder A is temporarily sintered along inner peripheral wall surface 41c of opening 41e of regulating plate 41. A is heated (heating step). In the heating process, temperature control of the regulation plate 41 by the control unit 4 may be performed.

  The cylindrical temporary sintered body 50 sequentially formed in the heating step descends while being in sliding contact with the buffer portion 42. The surface 50 a of the temporary sintered body 50 does not adhere to the inner circumferential wall surface 41 c of the regulating plate 41, and is relatively movable. The temporary sintered body 50 descends in the Z direction together with the lift table 35, the plate 31, the object C, and the powder A around it (see FIG. 2). And as FIG. 3 shows, the modeling thing C of a desired shape is modeled and a series of modeling processes are complete | finished. Since a temporary sintered body 50 having a tubular shape corresponding to the opening 41 e is formed in the modeling tank 36, the powder A does not leak out into the void G outside the temporary sintered body 50. .

  Then, after cooling (free cooling) of the shaped article C, for example, the shaped article C and the powder A between the temporary sintered body 50 are removed from the plate 31. The temporary sintered body 50 peels easily from the plate 31. Then, the powder A is recovered. Subsequently, excess powder A is exfoliated from the object C by, for example, blasting using the powder A. At the time of this blasting, the temporary sintered body 50 can be subdivided and returned to the same state as the powder A. The powder A and the regenerated powder A obtained by dividing the temporary sintered body 50 are reused in the subsequent steps. As described above, the thin cylindrical temporary sintered body 50 also serves as a holding container for the powder A in the modeling tank 36, and is relatively movable with respect to the restriction plate 41 and the buffer portion 42. Furthermore, reuse is also possible.

  According to the powder saving apparatus 100 and the powder saving method of the present embodiment described above, the shaping is performed on the lift table 35 provided in the shaping tank 36 and moving in the Z direction. The powder A is received only through the opening 41 e of the regulating plate 41 installed above the elevating table 35. Since a limited amount of powder A is supplied to the build tank 36, the powder A is saved when molding a small sized object C relative to the size of the build tank 36. The temporary sintered body 50 is formed along the inner peripheral wall surface 41 c of the opening 41 e of the restriction plate 41 by the lamp heater 47 and the heater 48. The temporary sintered body 50 is a cylinder having a cross section corresponding to the opening 41 e and extending in the Z direction. The temporary sintered body 50 formed into a cylindrical shape accommodates the shaped object C inside, and the powder A to the outside (the gap G between the temporary sintered body 50 and the side wall portion 36b of the forming tank 36) Prevent leakage. If the powder A in the modeling tank 36 leaks into the air gap G, the powder A in an amount corresponding to the leaked powder A flows into the modeling tank 36 through the opening 41 e. This further saves the amount of powder. Further, since the temporary sintered body 50 is made of the powder A in a state of not reaching melting, the temporary sintered body 50 does not easily adhere to the inner peripheral wall surface 41c of the opening 41e. In addition, the pre-sintered body 50 can be reused as the powder A by being crushed in a later step, and is not wasted. Therefore, the shaped object C can be shaped without any trouble (without causing sticking or the like) with only the amount of the raw material corresponding to the volume of the shaped object C. According to the powder saving apparatus 100, the configuration of the existing three-dimensional layered manufacturing apparatus 1 does not need to be largely changed, and the powder A is saved by a simple configuration including the regulation plate 41, the temperature sensor 46 and the lamp heater 47. can do. The shaping process is also simple because the temporary sintered body 50 is formed only by performing the heating process.

  The buffer portion 42 reliably prevents the temporary sintered body 50 from adhering to the inner circumferential wall surface 41 c of the opening 41 e of the regulating plate 41. As a result, when the elevating table 35 moves in the Z direction, the three-dimensional object C and the temporary sintered body 50 can move smoothly with respect to the restriction plate 41.

  Since the heater 48 is configured to heat the powder A via the restriction plate 41, the temporary sintered body 50 can be easily formed along the inner peripheral wall surface 41c of the opening 41e of the restriction plate 41. .

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment. For example, as shown in FIG. 5 (b), an attachment 45 for narrowing the discharge end 34a is attached to the lower end of the hopper 34 instead of the spacer 44 as a powder saving mechanism provided on the powder supply device 40 side. It is also good. This attachment 45 also provides the same powder saving effect as shown in FIG.

  Further, the heating of the powder A for forming the temporary sintered body 50 may be performed by the electron beam emitting unit 2. As shown in FIG. 6A, first, the entire surface of the modeling surface S is irradiated with the electron beam B so that the powder A is heated to a relatively low temperature (first preheating step). Subsequently, the electron beam B is applied to the vicinity of the inner circumferential wall surface 41c and the area of the object C and the area in the vicinity thereof so that the powder A is heated to a relatively high temperature (second preliminary Heating process). According to these steps, the first preheating region R1 and the second preheating region R2 subjected to the second preheating step are formed on the shaped surface S only by the first preheating step. The outer frame-like second preheating area R2 corresponds to the temporary sintered body 50 of the above embodiment. The first preheating region R1 includes the powder A shown in FIG.

  Further, as shown in FIG. 6B, the first preheating region R1 may not be left. That is, also in the second preheating step, the entire surface of the modeling surface S may be irradiated with the electron beam B. In that case, the powder A shown in FIG. 2 does not exist, and the second preheating region R2, that is, the temporary sintered body 50 is formed in the entire area other than the shaped object C. The temporary sintered body 50 thus formed is also reusable as the powder A. When the temporary sintered body 50 is formed by the electron beam emitting unit 2, the electron beam emitting unit 2 doubles as a component of the three-dimensional layered manufacturing apparatus 1 and a component of the powder saving device 100.

  The preheating steps shown in FIG. 6A and FIG. 6B described above may be performed by the temperature sensor 46 and the lamp heater 47 of the powder saving device 100.

  The structure to which the restricting plate 41 is attached may be different from the above embodiment. For example, the upper end surface 36 a of the modeling tank 36 may be flush with the upper surface 39 a of the work table 39, and the restriction plate 41 may be attached to the inner surface side of the modeling tank 36. In that case, the restriction plate 41 may be fixed so as to be tensioned against the inner surface of the side wall portion 36 b of the modeling tank 36.

  A buffer part such as a coating part or a heat resistant cloth may be omitted. The heating unit is not limited to the lamp heater 47 or the heater 48. As described above, temporary sintering may be performed by the electron beam emitting unit 2 (energy beam emitting unit). In this case, the electron beam emitting unit 2 (energy beam emitting unit) for forming a shape also serves as a heating unit for saving powder.

  The configuration for moving the modeling table relative to the modeling tank 36 is not limited to the form in which the lifting table 35 is lowered by the lifting device 10, and the modeling tank 36 may be removed by another lifting mechanism with respect to the fixed modeling table. A rising form may be employed. In that case, a structure may be employed in which the coating mechanism 33, the work table 39, the powder supply device 40, the shaping tank 36, the regulating plate 41, the lamp heater 47, the heater 48, and the electron beam emitting unit 2 rise with shaping.

  The three-dimensional additive manufacturing apparatus is not limited to the forming apparatus to which the electron beam melting method is applied, and may be, for example, a forming apparatus to which the laser melting method is applied. That is, the beam irradiated to the powder A in the three-dimensional additive manufacturing apparatus may be a laser beam. The beam irradiated to the powder A in the three-dimensional additive manufacturing apparatus may be a charged particle beam which is a concept including an electron beam and an ion beam. The beam irradiated to the powder A in the three-dimensional additive manufacturing apparatus may be an energy beam capable of supplying energy to the powder A.

  The powder A (forming material) is not limited to metal, and may be, for example, a resin.

Reference Signs List 1 three-dimensional layered modeling apparatus 2 electron beam emitting unit 3 shaping unit 4 control unit 10 lifting device 31 plate 34 hopper 35 lifting table (molding table)
36 Modeling tank 39 Work platform 40 Powder supply device 41 Regulating plate 41 c Inner peripheral wall surface (peripheral wall surface)
41e Opening 42 Buffering part 46 Temperature sensor 47 Lamp heater (heating part)
48 heater (heating unit)
50 temporary sintered body 100 powder saving device A powder B electron beam (energy beam)
C 3D object G air gap R1 first preheating area R2 second preheating area S forming surface

Claims (4)

Tertiary provided with a shaping tank in which a shaped object obtained by melting powder is shaped, and a shaping table provided in the shaping tank and moved relative to the shaping tank in the axial direction of the shaping tank A powder saving device applied to a three-dimensional additive manufacturing apparatus,
A regulating plate installed above the modeling table and having an opening formed therein, the regulating plate receiving the powder only through the opening and regulating the amount of the powder supplied to the modeling tank;
A heating unit configured to heat the powder so as to form a temporary sintered body in which the powder is temporarily sintered along the peripheral wall surface of the opening of the restriction plate.   The powder saving device according to claim 1, wherein a buffer portion is provided on the peripheral wall surface of the opening of the restriction plate so as to be interposed between the temporary sintered body and the peripheral wall surface.   The powder saving device according to claim 1, wherein the heating unit is configured to heat the powder through the restriction plate. Tertiary provided with a shaping tank in which a shaped object obtained by melting powder is shaped, and a shaping table provided in the shaping tank and moved relative to the shaping tank in the axial direction of the shaping tank A powder saving method applied to a three-dimensional additive manufacturing apparatus, comprising:
A receiving step of receiving the powder only through an opening of a regulation plate disposed above the shaping table;
The powder is heated so as to form a temporary sintered body in which the powder is temporarily sintered along the peripheral wall surface of the opening of the restriction plate while melting the powder received in the receiving step. A heating step, and a powder saving method.

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