Three-dimensional molding machine and preheating device

Abstract

This shaping device comprises a table, a forming unit that forms a shaped object, and a controller that controls an operation of the forming unit. The table rotates in a rotation direction. The forming unit has a feeder for forming a powder bed, a heater that can pre-heat each of a plurality of regions on the powder bed at different temperatures, and a beam source that irradiates the pre-heated powder bed with an energy beam. The controller includes: a region dividing unit that divides the powder bed into a plurality of small regions; a region setting unit that sets, as a first region, a small region including a planned irradiation section to be irradiated with the energy beam by the beam source, and sets, as a second region, at least one small region among the other regions not set as the first region; and a heater control unit that controls the output of the heater such that the first region and the second region are pre-heated at mutually differing temperatures.

Description

Technical Field

[0001] The present disclosure relates to a three-dimensional shaping device and a preheating device.

Background Art

[0002] Patent Document 1 discloses a technique related to a three-dimensional shaping device. The three-dimensional shaping device disclosed in Patent Document 1 supplies a powder material onto a table, preheats the powder material supplied onto the table, and irradiates the preheated powder material with an energy beam to shape a three-dimensional shaped object.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the three-dimensional shaping device as described above, the entire powder bed formed of the powder material is preheated at a uniform temperature. In this case, for example, since a semi-sintered body is generated by preheating even in a region that does not constitute the shaped object in the powder bed, it takes time to remove the semi-sintered body, and it may be difficult to smoothly continue the shaping process of the continuous shaped object.

[0005] The present disclosure describes a three-dimensional shaping device and a preheating device that can perform a shaping process efficiently.

Means for Solving the Problems

[0006] A three-dimensional molding apparatus according to one aspect of the present disclosure comprises a table having a main surface to which powder material is supplied, a forming unit arranged opposite to the main surface and forming a molded object by stacking a plurality of molded parts formed from the powder material, and a controller for controlling the operation of the forming unit. The table rotates relative to the forming unit in a predetermined rotational direction about a rotation axis. The forming unit comprises a supply unit that forms a powder bed by supplying powder material to the main surface, a preheating unit arranged downstream of the supply unit in the rotational direction and capable of preheating each of a plurality of regions in the powder bed at different temperatures, and an irradiation unit arranged downstream of the preheating unit in the rotational direction and irradiating at least a portion of the preheated powder bed with an energy beam. The controller includes a region division unit that divides the powder bed into a plurality of sub-regions, a region setting unit that sets a sub-region containing the portion to be irradiated with an energy beam by an irradiation unit as the first region, and sets at least one of the other sub-regions not set as the first region as the second region, and a preheating control unit that controls the output of the preheating unit so that the first region and the second region are preheated at different temperatures. [Effects of the Invention]

[0007] According to the three-dimensional molding apparatus and preheating apparatus described herein, molding can be performed efficiently. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 shows a cross-section of the molding apparatus according to the first embodiment. [Figure 2] Figure 2 shows the forming section of the molding apparatus shown in Figure 1. [Figure 3] Figure 3 is a block diagram showing the controller of the molding apparatus shown in Figure 1. [Figure 4] Figure 4 shows the powder bed being preheated by the molding apparatus shown in Figure 1. [Figure 5] Figure 5 shows the powder bed being preheated by the preheating treatment of the powder bed according to the first modified example. [Figure 6]Figure 6 shows the powder bed being preheated by the preheating treatment of the powder bed according to the first modified example. [Figure 7] Figure 7 shows the powder bed being preheated by the preheating treatment of the powder bed according to the second modified example. [Figure 8] Figure 8 shows the powder bed being preheated by the molding apparatus according to the second embodiment. [Figure 9] Figure 9 shows the powder bed being preheated by the molding apparatus according to the third embodiment. [Modes for carrying out the invention]

[0009] A three-dimensional molding apparatus according to one aspect of the present disclosure comprises a table having a main surface to which powder material is supplied, a forming unit arranged opposite to the main surface and forming a molded object by stacking a plurality of molded parts formed from the powder material, and a controller for controlling the operation of the forming unit. The table rotates relative to the forming unit in a predetermined rotational direction about a rotation axis. The forming unit comprises a supply unit that forms a powder bed by supplying powder material to the main surface, a preheating unit arranged downstream of the supply unit in the rotational direction and capable of preheating each of a plurality of regions in the powder bed at different temperatures, and an irradiation unit arranged downstream of the preheating unit in the rotational direction and irradiating at least a portion of the preheated powder bed with an energy beam. The controller includes a region division unit that divides the powder bed into a plurality of sub-regions, a region setting unit that sets a sub-region containing the portion to be irradiated with an energy beam by an irradiation unit as the first region, and sets at least one of the other sub-regions not set as the first region as the second region, and a preheating control unit that controls the output of the preheating unit so that the first region and the second region are preheated at different temperatures.

[0010] In this 3D printing apparatus, the region division unit divides the powder bed into multiple sub-regions, the region setting unit sets the sub-region containing the area to be irradiated by the energy beam by the irradiation unit as the first region, and sets at least one of the other sub-regions not set as the first region as the second region, and the preheating control unit controls the output of the preheating unit so that the first region and the second region are preheated at different temperatures. As a result, the 3D printing apparatus can, for example, set the sub-region containing the area to be irradiated by the energy beam as the first region, set the sub-region not containing the area to be irradiated as the second region, and preheat the second region at a lower temperature than the first region. In other words, even when the 3D printing apparatus preheats the area to be irradiated by the energy beam (the powder material that constitutes the printed object) at a high temperature, it can preheat the area of ​​the powder bed that is not irradiated by the energy beam (the powder material that does not constitute the printed object) at a low temperature. Therefore, it is less likely that pre-sintered bodies will form in the powder material that does not constitute the printed object, and the time required to remove pre-sintered bodies can be reduced. Therefore, this three-dimensional printing device allows for efficient printing processes.

[0011] The preheating control unit of the three-dimensional molding apparatus described above may control the output of the preheating section so that the first region is preheated to a higher temperature than the second region. With this configuration, the area of ​​the powder bed that is to be irradiated with the energy beam can be preheated more reliably.

[0012] The preheating control unit of the three-dimensional molding apparatus described above may control the output of the preheating section so that the first region is preheated to a temperature above the pre-sintering temperature of the powder material, and the second region is preheated to a temperature below the pre-sintering temperature. With this configuration, the region of the powder bed irradiated with the energy beam (the powder material constituting the molded object) can be preheated more reliably, and the formation of pre-sintered bodies in the region not irradiated with the energy beam (the powder material not constituting the molded object) can be suppressed more reliably.

[0013] The region division section of the three-dimensional molding apparatus described above may divide the powder bed into multiple sub-regions in the radial direction of a circle centered on the rotation axis. With this configuration, when the region irradiated with an energy beam and the region not irradiated with an energy beam are located side by side in the radial direction of a circle centered on the rotation axis, for example, the region irradiated with an energy beam (the powder material constituting the molded object) can be preheated to a temperature above the pre-sintering temperature of the powder material, while the region not irradiated with an energy beam (the powder material not constituting the molded object) can be preheated to a temperature below the pre-sintering temperature. Therefore, the powder material constituting the molded object can be preheated more reliably, and the formation of pre-sintered bodies in the powder material not constituting the molded object can be suppressed more reliably.

[0014] The region division section of the three-dimensional molding apparatus described above may divide the powder bed into multiple sub-regions in the rotational direction around the rotation axis. With this configuration, when the region irradiated with the energy beam and the region not irradiated with the energy beam are located side by side in the rotational direction around the rotation axis, for example, the region irradiated with the energy beam (the powder material constituting the molded object) can be preheated to a temperature above the pre-sintering temperature of the powder material, and the region not irradiated with the energy beam (the powder material not constituting the molded object) can be preheated to a temperature below the pre-sintering temperature. Therefore, the powder material constituting the molded object can be preheated more reliably, and the formation of pre-sintered bodies in the powder material not constituting the molded object can be suppressed more reliably.

[0015] The preheating section of the three-dimensional molding apparatus described above has multiple divided preheating sections arranged radially in a circle centered on the rotation axis, and the preheating control unit may maintain a constant output for the divided preheating sections while the table rotates once. With this configuration, the preheating process by the preheating section is simplified, thereby reducing the processing load on the preheating section and the controller.

[0016] The preheating control unit of the above three-dimensional shaping apparatus may vary the output of the preheating unit while the table makes one rotation. According to this configuration, when the first region and the second region are arranged side by side in the rotational direction centered on the rotation axis, each of the first region and the second region can be preheated at a suitable temperature.

[0017] The plurality of shaping parts include a first shaping part and a second shaping part formed on the first shaping part. The region setting unit may set, as the first region, a small region including a portion that overlaps with a portion of the powder bed corresponding to the second shaping part among the plurality of small regions in the powder bed corresponding to the first shaping part. According to this configuration, for example, when preheating the powder bed corresponding to the first shaping part, the small region including the portion that overlaps with the portion of the powder bed corresponding to the second shaping part can be preheated at a high temperature. Thereby, when preheating the powder bed corresponding to the second shaping part, the portion of the powder bed corresponding to the second shaping part that is scheduled to be irradiated can be more reliably heated to a desired temperature.

[0018] The above three-dimensional shaping apparatus includes a temperature detection unit that detects the temperature of the powder bed. The preheating control unit may control the output of the preheating unit based on the detection result by the temperature detection unit. According to this configuration, the powder bed can be more reliably heated to a desired temperature.

[0019] The preheating unit of the above three-dimensional shaping apparatus may be arranged to face the main surface with the powder bed interposed therebetween. According to this configuration, the preheating of the powder bed can be performed more reliably.

[0020] A preheating device according to one aspect of the present disclosure is a preheating device for preheating powder material that will be sintered or melted to form an object when irradiated with an energy beam, comprising: a preheating unit capable of preheating each of a plurality of regions in a powder bed formed by the powder material supplied to the main surface of a table at different temperatures; and a controller for controlling the output of the preheating unit, wherein the controller comprises: a region division unit for dividing the powder bed into a plurality of sub-regions; a region setting unit for setting a sub-region containing the portion to be irradiated with an energy beam as a first region, and setting at least one of the other sub-regions not set as the first region as a second region; and a preheating control unit for controlling the output of the preheating unit so that the first region and the second region are preheated at different temperatures.

[0021] This preheating device is equipped with a preheating unit and controller similar to those of the three-dimensional molding apparatus described above. This allows the preheating device to, for example, set a small area including the area to be irradiated by the energy beam as a first region, and a small area not including the irradiated area as a second region, preheating the second region at a lower temperature than the first region. In other words, even when preheating the area to be irradiated by the energy beam (the powder material constituting the molded object) at a high temperature, the preheating device can preheat the areas of the powder bed not irradiated by the energy beam (the powder material not constituting the molded object) at a lower temperature. Therefore, pre-sintered bodies are less likely to form in the powder material not constituting the molded object, and the time required to remove pre-sintered bodies can be reduced. Thus, this preheating device enables efficient molding.

[0022] The embodiments for implementing this disclosure will be described in detail below with reference to the attached drawings. In the description of the drawings, the same elements will be denoted by the same reference numerals, and redundant explanations will be omitted.

[0023] [First Embodiment] The molding apparatus 1 shown in Figure 1 is a three-dimensional molding apparatus that forms a three-dimensional object 2S from a powder material 2. The molding apparatus 1 is a so-called 3D printer. The powder material 2 is, for example, a metal powder. The powder material 2 is, for example, titanium-based metal powder, Inconel powder, or aluminum powder. The powder material 2 is not limited to metal powder. The powder material 2 may be, for example, a resin powder, or a powder containing carbon fibers and resin such as CFRP (Carbon Fiber Reinforced Plastics). The powder material 2 may be other conductive powders. The powder material 2 is not limited to those that are conductive. For example, when a laser is used as the energy beam, the powder material 2 does not need to be conductive.

[0024] The molded object 2S is formed by irradiating powder material 2 with an electron beam. Specifically, the molding device 1 irradiates the powder material 2 with an electron beam. The temperature of the powder material 2 rises due to the irradiation with the electron beam. The heated powder material 2 sintersects or melts. When the irradiation with the electron beam ends, the temperature of the powder material 2 decreases. As a result, the powder material 2 solidifies. The molding device 1 applies new powder material 2 onto the solidified powder material 2 (hereinafter referred to as the "molded portion"), and then irradiates the applied powder material 2 with an electron beam to form a new molded portion. In this way, the molding device 1 forms the molded object 2S by stacking multiple molded portions by repeatedly applying powder material 2 and irradiating with an electron beam. In other words, the molded object 2S is formed from multiple stacked molded portions. In this example, the molding device 1 performs molding by irradiating powder material 2 applied on a rotating table 3 with an electron beam.

[0025] The molding apparatus 1 comprises a table 3, a forming unit 4, a controller 5, a drive unit 6, a housing 7, and a temperature detection unit 8. The table 3 has a pair of main surfaces 3a and 3b that face each other. The table 3 is circular in shape. Main surface 3a is a flat surface. Powder material 2 and molded object 2S are placed on main surface 3a. The table 3 rotates in a predetermined direction about the rotation axis C by the drive unit 6, which will be described later. Furthermore, the table 3 moves up and down along the rotation axis C. In this example, the rotation axis C is aligned vertically. The rotation axis C is perpendicular to the main surface 3a. In the following description, the terms "above" and "below" are used based on the state in which the rotation axis C is aligned vertically. For example, "member A is positioned above member B" means that member A is positioned further from the ground than member B, and "member A is positioned below member B" means that member A is positioned closer to the ground than member B.

[0026] A build tank 31 is positioned around the table 3. The build tank 31 is a container for holding powder material 2 on the main surface 3a of the table 3. The build tank 31 has a wall portion 31a. The wall portion 31a is formed to follow the outer edge of the table 3 when viewed from a direction along the axis of rotation C. The wall portion 31a holds the powder material 2 on the main surface 3a.

[0027] The forming unit 4 is positioned above the table 3. The forming unit 4 is positioned to face the main surface 3a of the table 3, with the powder material 2 in between. "The forming unit 4 facing the main surface 3a" means that, when viewed from a direction along the rotation axis C, at least a part of the forming unit 4 overlaps the main surface 3a. The forming unit 4 processes the powder material 2 to form a molded object 2S. The forming unit 4 includes a feeder 41, a heater 42, and a beam source 43. The feeder 41 supplies the powder material 2 to the main surface 3a of the table 3. The heater 42 preheats the supplied powder material 2. The beam source 43 irradiates the preheated powder material 2 with an electron beam to form the molded portion. The feeder 41, heater 42, and beam source 43 are electrically connected to the controller 5.

[0028] The controller 5 controls the molding apparatus 1. For example, based on the control of the controller 5, the forming unit 4 forms an object 2S on the table 3, and the drive unit 6 rotates and raises the table 3.

[0029] The drive unit 6 includes a rotation unit 61 for rotating the table 3 and a lifting unit 62 for raising and lowering the table 3. The rotation unit 61 and the lifting unit 62 are electrically connected to the controller 5. The rotation unit 61 includes a shaft portion 61a and an actuator such as a motor (not shown). The shaft portion 61a extends in a direction perpendicular to the main surface 3a of the table 3. One end of the shaft portion 61a is connected to the main surface 3b of the table 3. The actuator of the drive unit 6 rotates the shaft portion 61a in a predetermined rotational direction about the rotation axis C. As a result, the table 3 connected to the shaft portion 61a rotates in a predetermined rotational direction about the rotation axis C relative to the forming section 4. In this example, the table 3 rotates clockwise when viewed from above the main surface 3a. The lifting unit 62 includes an actuator such as a motor (not shown). The actuator of the lifting unit 62 raises and lowers the shaft portion 61a along the rotation axis C. As a result, the table 3 connected to the shaft portion 61a moves up and down along the rotation axis C relative to the forming portion 4. In other words, the lifting unit 62 moves the table 3 in a direction toward the forming portion 4 and in a direction toward the forming portion 4 along the rotation axis C.

[0030] The housing 7 defines a build space S for forming the object 2S. The housing 7 houses the table 3 on which the powder material 2 and the object 2S are placed, and the forming unit 4. The build space S is a depressurized, airtight space for forming the object 2S by the forming unit 4. A window 71 is formed in the wall 71a of the housing 7. The window 71 is a window that allows the temperature inside the build space S to be detected from outside the build apparatus 1. The window 71 is made of, for example, glass.

[0031] The temperature detection unit 8 detects the temperature of the powder material 2 through the window 71. The temperature detection unit 8 is, for example, a thermographic device or a radiation thermometer. The temperature detection unit 8 is electrically connected to the controller 5. The temperature detection unit 8 outputs the detection result to a database provided inside or outside the molding apparatus 1. The detection result of the temperature detection unit 8 is used, for example, to control the heater 42.

[0032] Referring to Figure 2, the details of the forming section 4 will be described. The feeder 41, heater 42, and beam source 43 are aligned with the main surface 3a of the table 3 when viewed from a direction along the rotation axis C. The feeder 41, heater 42, and beam source 43 are arranged in this order along the rotation direction R of the table 3. In this example, the rotation direction R is clockwise when viewing the table 3 from the main surface 3a. The heater 42 is located downstream of the feeder 41 along the rotation direction R. The beam source 43 is located downstream of the heater 42 along the rotation direction R.

[0033] The feeder 41 is a supply unit. The feeder 41 forms a powder bed 21 by supplying powder material 2 onto the main surface 3a of the table 3. The powder bed 21 is a layer of powder material 2 having a predetermined thickness. For example, the feeder 41 has a raw material tank (not shown) and a leveling unit. The raw material tank stores the powder material 2 and supplies it onto the main surface 3a. The leveling unit leveles the surface of the powder material 2 supplied onto the main surface 3a. This forms a powder bed 21 on the main surface 3a. The feeder 41 may have a roller unit, a rod-shaped member, or a brush unit instead of a leveling unit. The feeder 41 forms a supply area 41A on the main surface 3a. The supply area 41A is the area to which the powder material 2 is supplied by the feeder 41. Furthermore, the supply area 41A is also the area to which the supplied powder material 2 is leveled. The position of the supply area 41A does not change with respect to the rotation of the table 3. In other words, when table 3 and supply area 41A are defined by a certain coordinate system, table 3 rotates relative to that coordinate system. However, supply area 41A does not move relative to that coordinate system.

[0034] The heater 42 is a preheating unit. The heater 42 preheats the powder bed 21 formed by the feeder 41. The heater 42 is positioned above the main surface 3a of the table 3. Because the heater 42 is positioned above the main surface 3a of the table 3, at least the powder bed and the partially formed object 2S can be placed between the main surface 3a of the table 3 and the heater 42. The heater 42, together with the controller 5, constitutes the preheating device 9. In this example, the shape of the heater 42 is fan-shaped when viewed from a direction along the rotation axis C. "Preheating the powder bed" is the process of heating the powder bed 21 formed by the feeder 41 to a predetermined temperature before the electron beam is irradiated by the beam source 43. This heating process may be, for example, a process of pre-sintering the powder bed 21 (powder material 2). "Pre-sintering" is a state in which the powder materials 2 are joined together by diffusion at the minimum point due to the diffusion phenomenon. Hereinafter, the temperature at which powder material 2 pre-sintersects will be referred to as the "pre-sintering temperature." The heater 42 heats the powder material 2 to the pre-sintering temperature, for example. The pre-sintering temperature is, for example, a temperature of more than half the melting point of powder material 2. This is based on the fact that the diffusion phenomenon of sintering becomes active at temperatures of more than half the melting point. For example, if powder material 2 is titanium, the pre-sintering temperature is between 700°C and 800°C. The melting point of titanium alloy is approximately between 1500°C and 1600°C. If powder material 2 is aluminum, the pre-sintering temperature is 300°C. The melting point of aluminum is approximately 660°C.

[0035] The heater 42 is positioned above the table 3. The heater 42 preheats the powder material 2, for example, by radiant heat. The heater 42 may be, for example, an infrared heater. The heater 42 forms a preheating region 42A on the main surface 3a. The preheating region 42A is the region that is preheated by the heater 42. The position of the preheating region 42A does not change with respect to the rotation of the table 3. That is, when the table 3 and the preheating region 42A are defined by a certain coordinate system, the table 3 rotates with respect to that coordinate system. However, the preheating region 42A does not move with respect to that coordinate system.

[0036] The heater 42 has multiple divided heaters. The multiple divided heaters are multiple divided preheating sections. Each of the multiple divided heaters is arranged radially in a circle centered on the rotation axis C. In this example, the heater 42 has four first divided heaters 421, second divided heaters 422, third divided heaters 423, and fourth divided heaters 424. The first divided heaters 421, second divided heaters 422, third divided heaters 423, and fourth divided heaters 424 are arranged in this order outward from the rotation axis C.

[0037] The first divided heater 421 forms a first preheating region 421A in the powder bed 21, which is preheated by the first divided heater 421. The second divided heater 422 forms a second preheating region 422A in the powder bed 21, which is preheated by the second divided heater 422. The third divided heater 423 forms a third preheating region 423A in the powder bed 21, which is preheated by the third divided heater 423. The fourth divided heater 424 forms a fourth preheating region 424A in the powder bed 21, which is preheated by the fourth divided heater 424.

[0038] The first preheating region 421A, the second preheating region 422A, the third preheating region 423A, and the fourth preheating region 424A are arranged in this order outward from the axis of rotation C. The first preheating region 421A, the second preheating region 422A, the third preheating region 423A, and the fourth preheating region 424A constitute preheating region 42A. In the following description, when it is not necessary to distinguish between the first divided heater 421, the second divided heater 422, the third divided heater 423, and the fourth divided heater 424, they may be collectively referred to as "divided heaters."

[0039] Each segment heater is electrically connected to the controller 5 (see Figure 1). The output of each segment heater can be independently controlled by the controller 5. For example, the controller 5 can set the output of the first segment heater 421 and the fourth segment heater 424 lower than the output of the second segment heater 422 and the third segment heater 423. In this case, the regions passing through the first preheating region 421A and the fourth preheating region 424A in the powder bed 21 are preheated to a lower temperature than the regions passing through the second preheating region 422A and the third preheating region 423A in the powder bed 21. That is, the heater 42 can preheat each of the multiple regions in the powder bed 21 to different temperatures. As an example, the heater 42 can preheat the region passing through the first preheating region 421A to a temperature above the pre-sintering temperature of the powder material 2. Also, the heater 42 can preheat the region passing through the fourth preheating region 424A to a temperature above the pre-sintering temperature of the powder material 2. Furthermore, the heater 42 can preheat the region passing through the second preheating region 422A at a temperature lower than the pre-sintering temperature. Moreover, the heater 42 can preheat the region passing through the third preheating region 423A at a temperature lower than the pre-sintering temperature.

[0040] The beam source 43 is the irradiation unit. The beam source 43 irradiates the powder bed 21 with an electron beam. The beam source 43 is, for example, an electron gun. The beam source 43 generates an electron beam corresponding to the potential difference between the cathode and the anode. The beam source 43 then focuses the electron beam by adjusting the electric field and irradiates the powder bed 21 with that electron beam. The beam source 43 forms an irradiation region 43A on the main surface 3a. The irradiation region 43A is the region to which the electron beam can be irradiated by the beam source 43. The position of the irradiation region 43A does not change with respect to the rotation of the table 3. That is, when the table 3 and the irradiation region 43A are defined by a certain coordinate system, the table 3 rotates with respect to that coordinate system. However, the irradiation region 43A does not move with respect to that coordinate system.

[0041] The beam source 43 irradiates the powder bed 21 with an electron beam along a desired scanning line within the irradiation area 43A. In the example shown in Figure 2, the area P to be irradiated by the electron beam in the powder bed 21 is indicated by hatching. As shown in Figure 2, the shape of the area irradiated by the electron beam does not have to match the shape of the irradiation area 43A. The beam source 43 irradiates the area P to be irradiated with the electron beam as it passes through the irradiation area 43A due to the rotation of the table 3. The area of ​​the powder bed 21 irradiated with the electron beam is heated to a temperature higher than the temperature after preheating by the heater 42. Specifically, it is heated to the sintering temperature or melting temperature of the powder material 2. The area of ​​the powder bed 21 irradiated with the electron beam is sintered or melted. When the electron beam irradiation is finished, the temperature of the area irradiated with the electron beam decreases, and that area solidifies. The end of electron beam irradiation can also be said to be when it has finished passing through the irradiation area 43A. The solidified area becomes the molded part that constitutes the molded object 2S.

[0042] As described above, the supply area 41A, the preheating area 42A, and the irradiation area 43A do not change position with respect to the rotation of the table 3. Therefore, assuming a certain point on the table 3, that point passes through the supply area 41A, the preheating area 42A, and the irradiation area 43A in that order as the table 3 rotates. That is, by arranging the feeder 41, heater 42, and beam source 43 along the rotation direction R of the table 3 and rotating the table 3, the powder bed formation process, the preheating process of the powder bed 21, and the electron beam irradiation process can be performed in this order on the main surface 3a of the table 3. The molding apparatus 1 forms a new powder bed 21 by applying more powder material 2 to the powder bed 21 after forming a molding part on a powder bed 21. Then, the molding apparatus 1 preheats the newly formed powder bed 21 and forms the molding part by irradiating it with an electron beam. In this manner, the molding apparatus 1 repeatedly performs the powder bed formation process, the powder bed preheating process, and the electron beam irradiation process while rotating the table 3. As a result, a molded object 2S (see Figure 1) is formed by stacking multiple molded parts. The table 3 descends as the molding of the object 2S progresses. That is, the rotating unit 61 rotates the table 3. In parallel with this rotation, the lifting unit 62 lowers the table 3.

[0043] Figure 3 is a block diagram of the controller 5. The controller 5 is a computer composed of hardware such as a CPU (Central Processing Unit), ROM (Read Only Memory), and RAM (Random Access Memory), and software such as programs stored in the ROM. The controller 5 includes, for example, input signal circuits, output signal circuits, or power supply circuits. The controller 5 also includes, for example, an arithmetic unit and memory. The memory can store data necessary for various controls.

[0044] The controller 5 includes a feeder control unit 51, a heater control unit 52, a beam control unit 53, a rotation control unit 54, a lifting control unit 55, a region division unit 56, a data acquisition unit 57, and a region setting unit 58.

[0045] The feeder control unit 51 controls the feeder 41 in order to form a powder bed 21 by supplying powder material 2 onto the main surface 3a of the table 3. In other words, the feeder control unit 51 functions as a supply control unit. The feeder control unit 51 may also control, for example, the timing of supplying the powder material 2 onto the main surface 3a, the amount of powder material 2 supplied, and the operation of the recoater, which is a leveling unit. The feeder control unit 51 outputs a control signal to the feeder 41 for controlling the feeder 41. The feeder 41 operates based on the control signal received from the feeder control unit 51.

[0046] The heater control unit 52 controls the heater 42 in order to preheat the powder bed 21 formed on the main surface 3a of the table 3. In other words, the heater control unit 52 functions as a preheating control unit. The heater control unit 52 can control the output of each of the first divided heater 421, second divided heater 422, third divided heater 423, and fourth divided heater 424 of the heater 42. Controlling the output of the heater 42 (each divided heater) includes control of the output magnitude. Furthermore, controlling the output of the heater 42 (each divided heater) also includes control of turning the heater 42 (each divided heater) on and off. The heater control unit 52 controls the output of the heater 42 based on setting information received from the area setting unit 58, which will be described later. Details of the control process of the heater 42 based on the setting information will be described later with reference to Figure 4. In addition, the heater control unit 52 may control the heater 42 based on, for example, the material of the powder material 2, the type of powder material 2, and the rotation speed of the table 3. Furthermore, the heater control unit 52 may control the heater 42 based on, for example, the temperature data DT of the powder bed 21 received from the data acquisition unit 57, which will be described later. The heater control unit 52 outputs a control signal to the heater 42 for controlling the heater 42. The heater 42 operates based on the control signal received from the heater control unit 52.

[0047] The beam control unit 53 controls the beam source 43 in order to irradiate the powder bed 21 with an electron beam that sintersects or melts the powder material 2. In other words, the beam control unit 53 functions as an irradiation control unit. The beam control unit 53 controls, for example, the irradiation position of the electron beam, the start of irradiation, the stop of irradiation, the irradiation time, etc. The beam control unit 53 outputs control signals to the beam source 43 for controlling the beam source 43. The beam source 43 operates based on the control signals received from the beam control unit 53.

[0048] The rotation control unit 54 controls the rotation unit 61 in order to rotate the table 3. The rotation control unit 54 controls, for example, the rotation speed of the table 3. The rotation control unit 54 outputs control signals to the rotation unit 61 for controlling the rotation unit 61. The rotation unit 61 operates based on the control signals received from the rotation control unit 54.

[0049] The lifting control unit 55 controls the lifting unit 62 in order to raise and lower the table 3. The lifting control unit 55 controls, for example, the descent speed of the table 3. The lifting control unit 55 outputs a control signal to the lifting unit 62 for controlling the lifting unit 62. The lifting unit 62 operates based on the control signal received from the lifting control unit 55.

[0050] The region division unit 56 divides the powder bed 21 formed on the main surface 3a of the table 3 into multiple sub-regions. "Dividing the powder bed 21 into multiple sub-regions" does not mean physically dividing the powder bed 21, but rather setting up multiple sub-regions within the powder bed 21. In other words, "dividing the powder bed 21 into multiple sub-regions" means distinguishing one region from another within the powder bed 21. As an example, the region division unit 56 divides multiple regions preheated by each of the multiple division heaters into multiple sub-regions. Details of the region division process of the powder bed 21 will be described later with reference to Figure 4. The region division unit 56 outputs information indicating the shape and position of each divided sub-region to the region setting unit 58, which will be described later.

[0051] The data acquisition unit 57 acquires temperature data DT and slice data DS from a database DB located inside or outside the molding apparatus 1. The temperature data DT indicates the temperature of the powder bed 21 detected by the temperature detection unit 8. The temperature data DT may be, for example, the temperature of the powder bed 21 before it is preheated by the heater 42, or the temperature of the powder bed 21 after it has been preheated by the heater 42. The data acquisition unit 57 outputs the acquired temperature data DT to the heater control unit 52.

[0052] Slice data DS is data that shows the shape of the cross-section of the fabricated object 2S. In other words, slice data DS is data that shows the shape of each fabricated part that makes up the fabricated object 2S. Slice data DS is generated, for example, based on the three-dimensional CAD (Computer-Aided Design) data of the fabricated object 2S. A number of slice data DS is generated corresponding to the number of fabricated parts (number of layers) that make up the fabricated object 2S. Slice data DS is stored in the database DB. The data acquisition unit 57 outputs the acquired slice data DS to the area setting unit 58 and the beam control unit 53.

[0053] The region setting unit 58 sets the sub-region containing the irradiation target area P from among the multiple sub-regions divided by the region division unit 56 as the first region. Furthermore, the region setting unit 58 sets at least one of the other sub-regions not set as the first region A1 from among the multiple sub-regions divided by the region division unit 56 as the second region A2. First, the region setting unit 58 identifies the shape and position of the irradiation target area P in the powder bed 21 based on the slice data DS. As described above, the portion of the powder bed 21 irradiated by the electron beam becomes the fabricated portion. Therefore, the shape and position of the irradiation target area P coincide with the shape and position of the fabricated portion indicated by the slice data DS. Thus, the region setting unit 58 can identify the shape and position of the irradiation target area P in the powder bed 21 based on the slice data DS. Based on the identified shape and position of the irradiation target area P, the region setting unit 58 sets the sub-region containing the irradiation target area P as the first region A1. Furthermore, the region setting unit 58 sets at least one of the other sub-regions not set as the first region A1 as the second region A2. Note that "setting the sub-region containing the irradiation target portion P as the first region" means setting at least one of the sub-regions divided by the region division unit 56 that contains the irradiation target portion P as the first region A1. In other words, the region setting unit 58 sets the sub-region containing the irradiation target portion P as the first region A1. The region setting unit 58 outputs setting information to the heater control unit 52 indicating whether each sub-region is set as the first region or the second region.

[0054] Referring to Figure 4, an example of preheating treatment of the powder bed 21 by the molding apparatus 1 will be explained. First, the region division unit 56 divides the powder bed 21 formed on the main surface 3a of the table 3 into a plurality of small regions. In the example shown in Figure 4, the region division unit 56 divides the powder bed 21 into four small regions 211, 212, 213, and 214 in the radial direction of a circle centered on the rotation axis C. Small region 211 is a circular region centered on the rotation axis C. Small regions 212, 213, and 214 are a plurality of annular regions centered on the rotation axis C. Small regions 211, 212, 213, and 214 are located in this order outward from the rotation axis C. The outer diameter of small region 211 is the same as the inner diameter of small region 212. The outer diameter of small region 212 is the same as the inner diameter of small region 213. The outer diameter of small region 213 is the same as the inner diameter of small region 214.

[0055] The four sub-regions 211, 212, 213, and 214 are preheated by their respective divided heaters. Specifically, sub-region 211 is preheated by the first divided heater 421. Sub-region 212 is preheated by the second divided heater 422. Sub-region 213 is preheated by the third divided heater 423. Sub-region 214 is preheated by the fourth divided heater 424. That is, as the table 3 rotates, sub-region 211 passes through the first preheating region 421A. Sub-region 212 passes through the second preheating region 422A. Sub-region 213 passes through the third preheating region 423A. Sub-region 214 passes through the fourth preheating region 424A. The region division unit 56 outputs information indicating the shape and position of each divided sub-region to the region setting unit 58.

[0056] The region setting unit 58 sets each of the four sub-regions 211, 212, 213, and 214 divided by the region division unit 56 as either the first region A1 or the second region A2. In the example shown in Figure 4, the region setting unit 58 sets the sub-region containing the planned irradiation area P as the first region A1. The region setting unit 58 sets the sub-region not containing the planned irradiation area P as the second region A2. At this time, the region setting unit 58 identifies the planned irradiation area P based on the slice data DS received from the data acquisition unit 57. Sub-regions 212 and 213 contain the planned irradiation area P. On the other hand, sub-regions 211 and 214 do not contain the planned irradiation area P. Therefore, the region setting unit 58 sets sub-regions 212 and 213 as the first region A1. The region setting unit 58 sets sub-regions 211 and 214 as the second region A2. The region setting unit 58 outputs setting information to the heater control unit 52 indicating whether each sub-region is set to the first region A1 or the second region A2.

[0057] The heater control unit 52 controls the heater 42 based on the setting information received from the region setting unit 58. Specifically, it controls the output of the heater 42 so that the first region A1 and the second region A2 in the powder bed 21 are preheated to different temperatures. In the example shown in Figure 4, the heater control unit 52 controls the output of the heater 42 so that the first region A1 is preheated to a higher temperature than the second region A2. In other words, the heater control unit 52 controls the output of each divided heater so that the output of the second divided heater 422 that preheats the small region 212 and the third divided heater 423 that preheats the small region 213 is higher than the output of the first divided heater 421 that preheats the small region 211 and the fourth divided heater 424 that preheats the small region 214. The heater control unit 52 may also control the output of the heater 42 (each divided heater) so that the first region A1 is preheated to a temperature equal to or higher than the pre-sintering temperature of the powder material 2. The heater control unit 52 may control the output of the heaters 42 (each segment heater) so that the second region A2 is preheated to a temperature lower than the pre-sintering temperature of the powder material 2. The heater control unit 52 maintains a constant output of the heaters 42 (each segment heater) while the table 3 rotates once. In other words, the heater control unit 52 maintains a constant output of the heaters 42 while the powder bed 21 corresponding to one slice data DS is preheated.

[0058] The heater control unit 52 may control the output of the heater 42 based on the temperature data DT received from the data acquisition unit 57. In this case, the heater control unit 52 may control the output of the heater 42 based on the temperature of the powder bed 21 before it is preheated by the heater 42. The heater control unit 52 may also control the output of the heater 42 based on the temperature of the powder bed 21 after it has been preheated by the heater 42. For example, the heater control unit 52 may lower the output of the heater 42 when the temperature of the powder bed 21 before it is preheated by the heater 42 is higher than the expected temperature. The heater control unit 52 may increase the output of the heater 42 when the temperature of the powder bed 21 before it is preheated is lower than the expected temperature. The heater control unit 52 may also lower the output of the heater 42 when the temperature of the powder bed 21 after it has been preheated is higher than the desired temperature. The heater control unit 52 may increase the output of the heater 42 when the temperature of the powder bed 21 after preheating is lower than the desired temperature.

[0059] The powder bed 21, preheated by the preheating treatment described above, is moved to the irradiation area 43A by the rotation of the table 3. Then, the electron beam is irradiated onto the area P to be irradiated. The beam control unit 53, which controls the beam source 43, may identify the area P to be irradiated based on slice data DS and determine the position to irradiate with the electron beam.

[0060] The following describes the operation and effects of the molding device 1.

[0061] In the molding apparatus 1, the region division unit 56 divides the powder bed 21 into a plurality of small regions 211, 212, 213, and 214. The region setting unit 58 sets the small regions 212 and 213, which include the irradiation area P that will be irradiated by the electron beam from the beam source 43, as the first region A1. The region setting unit 58 sets the other small regions 211 and 214 that are not set as the first region A1 as the second region A2. In other words, the region setting unit 58 sets the small regions that will not be irradiated by the electron beam as the second region A2. The heater control unit 52 controls the output of the heaters 42 (each divided heater) so that the first region A1 and the second region A2 are preheated to different temperatures. Specifically, the heater control unit 52 controls the output of the heaters 42 so that the first region A1 is preheated to a higher temperature than the second region A2. As a result, even when the area irradiated by the electron beam is preheated at a high temperature, the molding apparatus 1 can preheat the area of ​​the powder bed 21 that is not irradiated by the electron beam at a lower temperature. In other words, even when the molding apparatus 1 preheats the powder material 2 that constitutes the molded object 2S at a high temperature, the molding apparatus 1 can preheat the powder material 2 that does not constitute the molded object 2S at a lower temperature. Therefore, it is less likely that a pre-sintered body will form in the powder material 2 that does not constitute the molded object 2S, and the time required to remove the pre-sintered body can be reduced. Thus, with this molding apparatus 1, the molding process can be performed efficiently.

[0062] Furthermore, by preheating the powder material 2 that does not constitute the molded object 2S at a low temperature, oxidation of the powder material 2 can be suppressed. Therefore, the powder material 2 that does not constitute the molded object 2S can be reused in the molding process of other molded objects. In other words, the number of times the powder material 2 can be reused can be increased. The effects of the molding apparatus 1 described above are particularly advantageous when forming minute molded objects 2S on the powder bed 21.

[0063] The heater control unit 52 of the molding apparatus 1 controls the output of the heater 42 so that the first region A1 is preheated to a temperature equal to or higher than the pre-sintering temperature of the powder material 2. Furthermore, the heater control unit 52 controls the output of the heater 42 so that the second region A2 is preheated to a temperature lower than the pre-sintering temperature. With this configuration, the region of the powder bed 21 irradiated by the electron beam can be preheated more reliably. In other words, the powder material 2 constituting the molded object 2S can be preheated more reliably. Furthermore, the occurrence of pre-sintered bodies in regions not irradiated by the electron beam can be suppressed more reliably. In other words, the occurrence of pre-sintered bodies in the powder material 2 that does not constitute the molded object 2S can be suppressed more reliably.

[0064] The region division unit 56 of the molding apparatus 1 divides the powder bed 21 into a plurality of small regions 211, 212, 213, and 214 in the radial direction of a circle centered on the rotation axis C. With this configuration, when the region irradiated by the electron beam and the region not irradiated by the electron beam are located side by side in the radial direction of a circle centered on the rotation axis C, for example, the region irradiated by the electron beam can be preheated to a temperature above the pre-sintering temperature of the powder material 2, while the region not irradiated by the electron beam can be preheated to a temperature below the pre-sintering temperature. In other words, the powder material 2 that constitutes the molded object 2S can be preheated to a temperature above the pre-sintering temperature of the powder material 2, while the powder material 2 that does not constitute the molded object 2S can be preheated to a temperature below the pre-sintering temperature. Therefore, the powder material 2 that constitutes the molded object 2S can be preheated more reliably. Furthermore, the formation of pre-sintered bodies in the powder material 2 that does not constitute the molded object 2S can be suppressed more reliably.

[0065] The heater 42 of the molding apparatus 1 has a plurality of first-part heaters 421, second-part heaters 422, third-part heaters 423, and fourth-part heaters 424 arranged radially in a circle centered on the rotation axis C. The heater control unit 52 maintains a constant output for the first-part heaters 421, second-part heaters 422, third-part heaters 423, and fourth-part heaters 424 while the table rotates once. With this configuration, the preheating process by the heater 42 is simplified. As a result, the processing load on the heater 42 and the controller 5 is reduced.

[0066] The molding apparatus 1 includes a temperature detection unit 8 that detects the temperature of the powder bed 21. The heater control unit 52 controls the output of the heater 42 based on the temperature data DT, which is the result of detection by the temperature detection unit 8. With this configuration, the powder bed 21 can be heated to the desired temperature more reliably.

[0067] The heater 42 of the molding apparatus 1 is positioned to face the main surface 3a of the table 3, with the powder bed 21 in between. This configuration allows for more reliable preheating of the powder bed 21.

[0068] [First variation] Referring to Figures 5 and 6, a first modified example of the preheating treatment of the powder bed by the molding apparatus 1 will be described. As described above, the molded object 2S is formed by stacking multiple molded parts. The multiple molded parts that make up the molded object 2S have a first molded part and a second molded part. The second molded part is formed on top of the first molded part. Figure 5 shows the powder bed 21A for forming the first molded part. Figure 6 shows the powder bed 21B for forming the second molded part which is formed on top of the first molded part. The second molded part is formed continuously after the first molded part is formed. That is, after the molding apparatus 1 has formed the first molded part in the powder bed 21A, it forms a new powder bed 21B on top of the powder bed 21A. Then, the molding apparatus 1 forms the second molded part in the powder bed 21B.

[0069] As shown in Figures 5 and 6, the region division section 56 divides the powder beds 21A and 21B into four sub-regions 211, 212, 213, and 214, respectively. The shape and position of the sub-regions 211, 212, 213, and 214 in the first modified example are the same as in the first embodiment (see Figure 4). In the powder bed 21A, the beam source 43 irradiates the irradiation area P1 shown in Figure 5 with an electron beam. In the powder bed 21B, the beam source 43 irradiates the irradiation area P2 shown in Figure 6 with an electron beam. That is, the part of the powder bed 21A corresponding to the irradiation area P1 is the first molding area. The part of the powder bed 21B corresponding to the irradiation area P2 is the second molding area. In the first modified example, the shape of the irradiation area P1 is different from that of the irradiation area P2. Specifically, in the powder bed 21A shown in Figure 5, the part indicated by the dashed line is not included in the irradiation area P1. In the powder bed 21A, the portion indicated by the dashed line is hereinafter referred to as "overlapping portion P10".

[0070] Based on the above, the preheating treatment of the powder bed 21A will now be explained. First, the region setting unit 58 sets the four sub-regions 211, 212, 213, and 214 divided by the region division unit 56 as a sub-region including the irradiation target portion P1. Furthermore, the sub-region including the portion of the powder bed 21A that overlaps with the irradiation target portion P2 of the powder bed 21B is also set as the first region A1. The portion of the powder bed 21A that overlaps with the irradiation target portion P2 of the powder bed 21B is the irradiation target portion P1 and the overlapping portion P10. The irradiation target portion P1 and the overlapping portion P10 overlap the irradiation target portion P2 in the stacking direction of the powder beds 21A and 21B (the direction along the rotation axis C). Therefore, in addition to the sub-regions 212 and 213 including the irradiation target portion P1, the region setting unit 58 sets the sub-region 214 including the overlapping portion P10 as the first region A1. The region setting unit 58 sets the small region 211 that is not set as the first region A1 as the second region A2. In other words, the region setting unit 58 sets as the second region A2 only the small regions in the powder bed 21A that do not include the irradiation area P1 and do not overlap with the irradiation area P2 in the powder bed 21B. The region setting unit 58 outputs setting information to the heater control unit 52 indicating whether each small region in the powder bed 21A is set as the first region A1 or the second region A2.

[0071] The heater control unit 52 controls the heater 42 based on the setting information received from the region setting unit 58. Specifically, it controls the output of the heater 42 so that the first region A1 and the second region A2 are preheated to different temperatures. In the first modified example, the heater control unit 52 controls the output of the heater 42 so that the first region A1 is preheated to a higher temperature than the second region A2. In other words, the heater control unit 52 controls the output of each divided heater so that the output of the second divided heater 422 that preheats the small region 212, the third divided heater 423 that preheats the small region 213, and the fourth divided heater 424 that preheats the small region 214 is higher than the output of the first divided heater 421 that preheats the small region 211.

[0072] The heater control unit 52 may control the output of the heater 42 so that the first region A1 is preheated to a temperature equal to or greater than the pre-sintering temperature of the powder material 2. Furthermore, the heater control unit 52 may control the output of the heater 42 so that the second region A2 is preheated to a temperature lower than the pre-sintering temperature of the powder material 2. After the preheating process by the heater 42 is completed, the beam source 43 irradiates the irradiation target portion P1 of the powder bed 21A, which has been preheated by the heater 42, with an electron beam. This forms the first fabricated portion.

[0073] Next, the feeder 41 forms a new powder bed 21B on top of the powder bed 21A to form the second molding section (see Figure 6). In this example, not only the small regions 212 and 213 of the powder bed 21A but also the small region 214 is preheated at a high power beforehand. Therefore, before the formed powder bed 21B is preheated by the heater 42, the temperature of the small regions 212, 213, and 214 of the powder bed 21B is raised by the heat from the small regions 212, 213, and 214 of the powder bed 21A.

[0074] The region setting unit 58 sets each of the sub-regions 211, 212, 213, and 214 in the powder bed 21B as either the first region A1 or the second region A2. The region setting unit 58 may also set the first region A1 and the second region A2 in the powder bed 21B using the same method as in the powder bed 21A. That is, if the fabricated portion formed on the second fabricated portion is the third fabricated portion, the region setting unit 58 sets the sub-region containing the planned irradiation portion P2 among the four sub-regions 211, 212, 213, and 214 as the first region A1. Furthermore, the region setting unit 58 may also set the sub-region containing the portion that overlaps with the planned irradiation portion of the powder bed corresponding to the third fabricated portion in the powder bed 21B as the first region A1.

[0075] The region setting unit 58 outputs setting information to the heater control unit 52 indicating whether each sub-region in the powder bed 21B is set to the first region A1 or the second region A2. The heater control unit 52 controls the heater 42 based on the setting information received from the region setting unit 58. The beam source 43 irradiates the irradiation target portion P2 of the powder bed 21B, which has been preheated by the heater 42, with an electron beam. As a result, a second molding portion is formed on top of the first molding portion. The molding apparatus 1 can obtain a molded object 2S by forming multiple molding portions on top of the second molding portion using the same method.

[0076] In the first modified example, the multiple fabrication parts that form the fabricated object 2S include a first fabrication part and a second fabrication part formed on the first fabrication part. The region setting unit 58 sets the irradiation-planned part P1 that overlaps the irradiation-planned part P2 of the powder bed 21B corresponding to the second fabrication part as the first region A1, from among the multiple sub-regions 211, 212, 213, 214 in the powder bed 21A corresponding to the first fabrication part. Furthermore, the region setting unit 58 additionally sets the sub-regions 213, 214 including the overlapping part P10 as the first region A1, from among the multiple sub-regions 211, 212, 213, 214 in the powder bed 21A corresponding to the first fabrication part. With this configuration, for example, when preheating the powder bed 21A corresponding to the first fabrication part, the sub-regions 212, 213, 214 including the irradiation-planned part P1 and the overlapping part P10 can be preheated at a high temperature. Therefore, before the powder bed 21B is preheated by the heater 42, the temperature of the small regions 212, 213, and 214 of the powder bed 21B is preheated by the heat from the small regions 212, 213, and 214 of the powder bed 21A. This makes it possible to more reliably raise the irradiation area P2 to the desired temperature when preheating the powder bed 21B corresponding to the second molding area. In other words, when preheating the powder bed 21B corresponding to the second molding area, the irradiation area P2 can be heated uniformly while maintaining the desired temperature.

[0077] [Second variation] Referring to Figure 7, a second modified example of the preheating treatment of the powder bed by the molding apparatus 1 will be described. Figure 7 shows the powder bed 21C formed on the main surface 3a of the table 3 and the irradiation area P3 in the powder bed 21C. In the second modified example, the region division unit 56 divides the powder bed 21 into a plurality of small regions not only in the radial direction of a circle centered on the rotation axis C, but also in the rotation direction R. In the second modified example, the plurality of small regions divided by the region division unit 56 include small regions 215 and 216. Small regions 215 and 216 are aligned in the rotation direction R. Small regions 215 and 216 are regions that are preheated by the same fourth division heater 424. That is, small regions 215 and 216 pass through the fourth preheating region 424A shown in Figure 2.

[0078] In the second modified example, the region setting unit 58 sets a small region including the planned irradiation portion P3 as the first region A1. Furthermore, the region setting unit 58 sets a small region not including the planned irradiation portion P3 as the second region A2. At this time, the region setting unit 58 may identify the planned irradiation portion P3 based on slice data DS or division data. Division data is data generated by dividing the slice data DS in the circumferential direction (rotation direction R) around the rotation axis C of the table 3. In other words, division data is generated as data for a fan-shaped region. The division angle of the division data may be a constant angle. The division angle of the division data may be, for example, an angle of 45° or less. As shown in Figure 7, the small region 215 includes the planned irradiation portion P3. On the other hand, the small region 216 does not include the planned irradiation portion P3. Therefore, the region setting unit 58 sets the small region 215 as the first region A1. Furthermore, the region setting unit 58 sets the small region 216 as the second region A2. The region setting unit 58 also sets each of the other sub-regions as either the first region A1 or the second region A2. The region setting unit 58 outputs setting information to the heater control unit 52 indicating whether each sub-region is set as the first region A1 or the second region A2.

[0079] The heater control unit 52 controls the heater 42 based on the setting information received from the region setting unit 58. Specifically, it controls the output of the heater 42 so that the first region A1 and the second region A2 in the powder bed 21 are preheated to different temperatures. In the second modified example, similar to the first embodiment, the heater control unit 52 controls the output of the heater 42 so that the first region A1 is preheated to a higher temperature than the second region A2. The heater control unit 52 may also control the output of the heater 42 so that the first region A1 is preheated to a temperature equal to or higher than the pre-sintering temperature of the powder material 2. The heater control unit 52 may also control the output of the heater 42 so that the second region A2 is preheated to a temperature lower than the pre-sintering temperature of the powder material 2.

[0080] In the second modified example, the small regions designated as the first region A1 and the second region A2, such as small region 215 and small region 216, are arranged along the rotation direction R. These small regions may be preheated by the same divided heater. For example, small region 215, designated as the first region A1, and small region 216, designated as the second region A2, are preheated by the same fourth divided heater 424. Therefore, in the second modified example, the heater control unit 52 controls the output of the fourth divided heater 424 to be higher when small region 215 is located in the fourth preheating region 424A of the fourth divided heater 424. Furthermore, the heater control unit 52 controls the output of the fourth divided heater 424 to be lower when small region 216 is located in the fourth preheating region 424A. The heater control unit 52 also controls the output of the corresponding divided heaters at other locations where the first region A1 and the second region A2 are arranged along the rotation direction R. Thus, the heater control unit 52 according to the second modified example varies the output of the heater 42 (each segment heater) while the table 3 rotates once. In other words, the heater control unit 52 varies the output of the heater 42 while the powder bed 21C corresponding to one slice data DS is preheated.

[0081] The region division section 56 of the molding apparatus 1 according to the second modified example divides the powder bed 21 into a plurality of small regions 215, 216 along the rotation direction R centered on the rotation axis C. With this configuration, when the region irradiated by the electron beam and the region not irradiated by the electron beam are located side by side along the rotation direction R centered on the rotation axis C, for example, the region irradiated by the electron beam can be preheated to a temperature above the pre-sintering temperature of the powder material 2. In other words, the powder material 2 constituting the molded object 2S can be preheated to a temperature above the pre-sintering temperature of the powder material 2. Furthermore, the region not irradiated by the electron beam can also be preheated to a temperature lower than the pre-sintering temperature. In other words, powder material 2 not constituting the molded object 2S can also be preheated to a temperature lower than the pre-sintering temperature. Therefore, the powder material 2 constituting the molded object 2S can be preheated more reliably. Furthermore, the formation of pre-sintered bodies in the powder material 2 not constituting the molded object 2S can be suppressed more reliably.

[0082] The heater control unit 52 of the molding apparatus 1 according to the second modified example varies the output of the heater 42 while the table rotates once. With this configuration, when the first region A1 and the second region A2 are aligned in the rotation direction R about the rotation axis C, the first region A1 and the second region A2 can each be preheated to a suitable temperature.

[0083] [Second Embodiment] Referring to Figure 8, the molding apparatus 100 according to the second embodiment will be described. The molding apparatus 100 of the second embodiment includes a forming section 4A. The forming section 4A includes a feeder 41, a heater 142, and a beam source 43. The feeder 41 and beam source 43 of the second embodiment have the same configuration as the feeder 41 and beam source 43 of the first embodiment. Therefore, a detailed description of the feeder 41 and beam source 43 of the second embodiment will be omitted.

[0084] On the other hand, the heater 142 of the second embodiment has a different configuration from the heater 42 of the first embodiment. Specifically, the heater 142 does not have multiple segmented heaters. Therefore, the entire heater 142 is heated with a uniform output. The heater 142 is a single continuous heater that extends along the radial direction of a circle centered on the rotation axis C. The heater control unit 52 can vary the output of the heater 142. Therefore, by varying the output of the heater 142, the heater control unit 52 can preheat each of the multiple regions aligned in the rotation direction R in the powder bed 21D to different temperatures.

[0085] Figure 8 shows the powder bed 21D formed on the main surface 3a of the table 3 and the area P4 to be irradiated on the powder bed 21D. In the second embodiment, the region division unit 56 does not divide the powder bed 21D in the radial direction of a circle centered on the rotation axis C. The region division unit 56 divides the powder bed 21D into a plurality of sub-regions only in the rotation direction R. In the second embodiment, the plurality of sub-regions divided by the region division unit 56 include sub-regions 217 and 218. Sub-regions 217 and 218 are aligned in the rotation direction R. Sub-regions 217 and 218 are preheated by the same heater 142. That is, sub-regions 217 and 218 pass through the preheating region 142A of the heater 142.

[0086] Similar to the first embodiment, the region setting unit 58 of the second embodiment sets a small region including the irradiation target portion P4 as the first region A1. Furthermore, the region setting unit 58 of the second embodiment sets a small region not including the irradiation target portion P4 as the second region A2. As shown in Figure 8, small region 217 includes the irradiation target portion P4. On the other hand, small region 218 does not include the irradiation target portion P4. Therefore, the region setting unit 58 sets small region 217 as the first region A1. Furthermore, the region setting unit 58 sets small region 218 as the second region A2. The region setting unit 58 also sets each of the other small regions as either the first region A1 or the second region A2. The region setting unit 58 outputs setting information to the heater control unit 52 indicating whether each small region is set as the first region A1 or the second region A2.

[0087] The heater control unit 52 controls the heater 142 based on the setting information received from the region setting unit 58. Specifically, the heater control unit 52 controls the output of the heater 142 so that the first region A1 and the second region A2 in the powder bed 21D are preheated to different temperatures. Similar to the first embodiment, the heater control unit 52 of the second embodiment controls the output of the heater 142 so that the first region A1 is preheated to a higher temperature than the second region A2. The heater control unit 52 may also control the output of the heater 142 so that the first region A1 is preheated to a temperature equal to or higher than the pre-sintering temperature of the powder material 2. The heater control unit 52 may also control the output of the heater 142 so that the second region A2 is preheated to a temperature lower than the pre-sintering temperature of the powder material 2.

[0088] In the second embodiment, the small regions set as the first region A1 and the second region A2, such as small region 217 and small region 218, are aligned along the rotation direction R. Therefore, the heater control unit 52 of the second embodiment controls the output of the heater 142 to be higher when small region 217 is located in the preheating region 142A of the heater 142. The heater control unit 52 of the second embodiment controls the output of the heater 142 to be lower when small region 218 is located in the preheating region 142A. The heater control unit 52 also controls the output of the heater 142 to be appropriately varied at other locations where the first region A1 and the second region A2 are aligned along the rotation direction R. In this way, the heater control unit 52 of the second embodiment varies the output of the heater 142 while the table 3 rotates once. In other words, the heater control unit 52 varies the output of the heater 142 while the powder bed 21D corresponding to one slice data DS is being preheated.

[0089] The molding apparatus 100 according to the second embodiment can also preheat the area of ​​the powder bed 21D irradiated by the electron beam to a high temperature, similar to the molding apparatus 1 according to the first embodiment. In other words, the powder material 2 constituting the molded object 2S can be preheated to a high temperature. Furthermore, areas not irradiated by the electron beam can also be preheated to a low temperature. In other words, powder material 2 that does not constitute the molded object 2S can also be preheated to a low temperature. Therefore, it is less likely that pre-sintered bodies will form in the powder material 2 that does not constitute the molded object 2S, and the time required to remove pre-sintered bodies can be reduced. Thus, the molding apparatus 100 can perform the molding process efficiently.

[0090] [Third Embodiment] Referring to Figure 9, the molding apparatus 200 according to the third embodiment will be described. The molding apparatus 200 of the third embodiment includes a forming section 4B. The forming section 4B includes a feeder 41, a heater 242, and a beam source 43. The feeder 41 and beam source 43 of the third embodiment have the same configuration as the feeder 41 and beam source 43 of the first embodiment. Therefore, a detailed description of the feeder 41 and beam source 43 of the third embodiment will be omitted.

[0091] On the other hand, the heater 242 of the third embodiment has a different configuration from the heater 42 of the first embodiment. For example, the heater 242 has a rectangular shape when viewed from a direction along the rotation axis C. The heater 242 has a plurality of divided heaters 243 that are divided in a grid pattern. The plurality of divided heaters 243 are arranged along two directions that are orthogonal to each other.

[0092] The heater control unit 52 can independently control each segment heater 243. In other words, the heater control unit 52 can make the output of each segment heater 243 different from each other. Therefore, by controlling the output of each segment heater 243, the heater control unit 52 can preheat each of the multiple regions in the powder bed 21 to a different temperature. That is, the heater control unit 52 can control the output of the heater 242 (each segment heater 243) so that the first region A1 and the second region A2 (see Figure 4) in the powder bed 21, as set by the region setting unit 58, are preheated to different temperatures.

[0093] The molding apparatus 200 according to the third embodiment can also preheat the area irradiated by the electron beam to a high temperature, similar to the molding apparatus 1 according to the first embodiment. In other words, the powder material 2 constituting the molded object 2S can be preheated to a high temperature. Furthermore, the area of ​​the powder bed 21 that is not irradiated by the electron beam can be preheated to a low temperature. In other words, the powder material 2 that does not constitute the molded object 2S can be preheated to a low temperature. As a result, pre-sintered bodies are less likely to form in the powder material 2 that does not constitute the molded object 2S, and the time required to remove pre-sintered bodies can be reduced. Thus, the molding apparatus 200 can perform the molding process efficiently.

[0094] The three-dimensional molding apparatus and preheating apparatus of this disclosure have been described in detail above. However, the three-dimensional molding apparatus and preheating apparatus of this disclosure are not limited to the embodiments described above. The three-dimensional molding apparatus and preheating apparatus of this disclosure can be modified in various ways without departing from the spirit thereof.

[0095] For example, the heater control unit 52 may control the output of the heater 42 so that the first region A1 is preheated at a lower temperature than the second region A2. That is, the heater control unit 52 may set the output of the heater 42 (each segment heater) when preheating the first region A1 lower than the output of the heater 42 when preheating the second region A2.

[0096] The heater 42 can be any heater capable of preheating each of the multiple regions in the powder bed 21 to a different temperature. The shape and number of heaters 42 are not limited. The heater 42 does not have to be an infrared heater. It may be other heating means such as a gas heater.

[0097] The region setting unit 58 may also set small regions in the powder bed 21 that do not include the irradiation area P as the first region A1 in order to maintain the temperature of the already formed molded portion. In other words, small regions that are not irradiated by the electron beam may also be set as the first region A1. Furthermore, the heater control unit 52 may control the heater 42 so that the first region A1 is preheated to a higher temperature than the second region A2.

[0098] In the embodiments described above, a configuration in which the table 3 rotates and moves up and down was explained as an example. However, the table 3 may be fixed, and the forming section 4 may rotate about the rotation axis C and move up and down along the rotation axis C. In other words, the table 3 may rotate and move up and down relative to the forming section 4.

[0099] In the above embodiment, the powder material was sintered or melted by irradiation with an electron beam. However, the beam irradiated onto the powder material 2 is not limited to an electron beam. In other words, the beam irradiated onto the powder material may be any other energy beam. To put it another way, the beam used in the fabrication apparatus 1 can be any energy beam capable of supplying energy to the powder material 2. For example, the fabrication apparatus 1 may be one to which a laser melting method is applied. The beam used in the fabrication apparatus 1 may be a laser beam. The beam used in the fabrication apparatus 1 may be a charged particle beam, which is a concept that includes electron beams and ion beams.

[0100] The three-dimensional printing apparatus and preheating apparatus of this disclosure will be described with reference to the following clauses. The three-dimensional printing apparatus and preheating apparatus of this disclosure may include any combination of the following clauses, even without specific listing.

[0101] 1. A table having a main surface on which powder material is supplied, A forming section is positioned facing the main surface and stacks multiple forming parts made from the powder material to form a molded object, The system includes a controller for controlling the operation of the forming section, The table rotates relative to the forming section in a predetermined rotational direction about the axis of rotation, The formed portion is A supply unit that forms a powder bed by supplying the powder material to the main surface, A preheating unit is positioned downstream of the supply unit in the rotational direction and is capable of preheating each of the multiple regions in the powder bed at different temperatures. It has an irradiation unit positioned downstream of the preheating unit in the rotational direction and irradiating at least a portion of the preheated powder bed with an energy beam, The aforementioned controller, A region division unit that divides the powder bed into multiple small regions, A region setting unit sets a region among the plurality of subregions that includes the portion to be irradiated by the energy beam by the irradiation unit as the first region, and sets at least one of the other subregions not set as the first region as the second region. A three-dimensional molding apparatus comprising: a preheating control unit that controls the output of the preheating unit so that the first region and the second region are preheated at different temperatures from each other.

[0102] 2. The three-dimensional molding apparatus according to Clause 1, wherein the preheating control unit controls the output of the preheating unit so that the first region is preheated to a higher temperature than the second region.

[0103] 3. The three-dimensional molding apparatus according to Clause 1 or 2, wherein the preheating control unit controls the output of the preheating unit so that the first region is preheated to a temperature equal to or greater than the pre-sintering temperature of the powder material, and the second region is preheated to a temperature lower than the pre-sintering temperature.

[0104] 4. The three-dimensional molding apparatus according to any one of the clauses 1 to 3, wherein the region division section divides the powder bed into a plurality of sub-regions in the radial direction of a circle centered on the rotation axis.

[0105] 5. The three-dimensional molding apparatus according to any one of the clauses 1 to 4, wherein the region division section divides the powder bed into a plurality of sub-regions in the rotational direction centered on the rotation axis.

[0106] 6. The preheating unit has a plurality of divided preheating units arranged in the radial direction of a circle centered on the rotation axis, The three-dimensional molding apparatus according to any one of the clauses 1 to 5, wherein the preheating control unit maintains a constant output of the divided preheating unit while the table rotates once.

[0107] 7. The three-dimensional molding apparatus according to any one of the clauses 1 to 5, wherein the preheating control unit varies the output of the preheating unit while the table rotates once.

[0108] 8. The plurality of molded parts include a first molded part and a second molded part formed on the first molded part. The three-dimensional molding apparatus according to any one of the clauses 1 to 7, wherein the area setting unit sets a small area in the powder bed corresponding to the first molding area, which includes a portion that overlaps with the portion of the powder bed corresponding to the second molding area that is scheduled to be irradiated, as the first area.

[0109] 9. The system includes a temperature detection unit for detecting the temperature of the powder bed, The three-dimensional molding apparatus according to any one of the clauses 1 to 8, wherein the preheating control unit controls the output of the preheating unit based on the detection result of the temperature detection unit.

[0110] 10. The three-dimensional molding apparatus according to any one of the clauses 1 to 9, wherein the preheating section is arranged to face the main surface with the powder bed in between.

[0111] 11. A preheating device for preheating powder material that will be sintered or melted to form an object when irradiated with an energy beam, A preheating unit capable of preheating each of several regions in the powder bed formed by the powder material supplied to the main surface of the table at different temperatures, The system includes a controller that controls the output of the preheating unit, The aforementioned controller, A region division unit that divides the powder bed into multiple small regions, A region setting unit sets a region containing the portion to be irradiated with the energy beam as the first region, and sets at least one of the other regions not set as the first region as the second region. A preheating device comprising: a preheating control unit that controls the output of the preheating unit so that the first region and the second region are preheated at different temperatures. [Explanation of symbols]

[0112] 1,100,200 Molding equipment 2 Powder material 2S printed object 3 tables 3a,3b Main surface 4,4A,4B forming part 5 Controllers 6 Drive Unit 7 Housing 8. Temperature detection unit 9. Preheating device 21,21A,21B,21C,21D Powder bed 31. Molding Tank 31a Wall section 41 Feeder (supply unit) 41A supply area 42,142,242 Heater (preheating section) 42A, 142A Preheating Region 43. Beam source (irradiation unit) 43A irradiation area 51 Feeder Control Unit 52 Heater control unit 53 Beam control unit (preheating control unit) 54 Rotation Control Unit 55 Lifting control unit 56 Area division part 57 Data Acquisition Unit 58 Area setting section 61 Rotation Unit 61a Shaft 62 Lifting Unit 71 Window section 71a Wall section 211,212,213,214,215,216,217,218 small area 243-section heater 421 First divided heater (divided preheating section) 421A First preheating region 422 Second divided heater (divided preheating section) 422A Second preheating region 423 Third divided heater (divided preheating section) 423A Third preheating region 424 Fourth divided heater (divided preheating section) 424A Fourth preheating region A1 1st area A2 2nd area C Rotation axis DB Database DS slice data DT temperature data P,P1,P2,P3,P4 Area scheduled for irradiation P10 Overlapping section R rotation direction S Build space

Claims

1. A table having a main surface on which powder material is supplied, A forming section is positioned facing the main surface and stacks multiple forming parts made from the powder material to form a molded object, The system includes a controller that controls the operation of the forming section, The table rotates relative to the forming section in a predetermined rotational direction about the axis of rotation, The formed portion is A supply unit that forms a powder bed by supplying the powder material to the main surface, A preheating unit is positioned downstream of the supply unit in the rotational direction and is capable of preheating each of the multiple regions in the powder bed at different temperatures. It has an irradiation unit positioned downstream of the preheating unit in the rotational direction and irradiating at least a portion of the preheated powder bed with an energy beam, The aforementioned controller, A region division unit that divides the powder bed into multiple small regions, A region setting unit sets a region among the plurality of subregions that includes the portion to be irradiated by the energy beam by the irradiation unit as a first region, and sets at least one of the other subregions not set as the first region as a second region. The system includes a preheating control unit that controls the output of the preheating unit so that the first region and the second region are preheated at different temperatures from each other, A three-dimensional molding apparatus comprising a preheating control unit that controls the output of the preheating unit such that the first region is preheated to a temperature equal to or greater than the pre-sintering temperature of the powder material, and the second region is preheated to a temperature lower than the pre-sintering temperature.

2. The three-dimensional molding apparatus according to claim 1, wherein the preheating control unit controls the output of the preheating unit so that the first region is preheated to a higher temperature than the second region.

3. The three-dimensional molding apparatus according to claim 1 or 2, wherein the region division section divides the powder bed into a plurality of small regions in the radial direction of a circle centered on the rotation axis.

4. The three-dimensional molding apparatus according to claim 1 or 2, wherein the region division section divides the powder bed into a plurality of small regions in the rotational direction centered on the rotation axis.

5. The preheating unit has a plurality of divided preheating units arranged in the radial direction of a circle centered on the rotation axis, The three-dimensional molding apparatus according to claim 1 or 2, wherein the preheating control unit maintains a constant output of the divided preheating unit while the table rotates once.

6. The three-dimensional molding apparatus according to claim 1 or 2, wherein the preheating control unit varies the output of the preheating unit while the table rotates once.

7. The plurality of molded parts include a first molded part and a second molded part formed on the first molded part. The three-dimensional molding apparatus according to claim 1 or 2, wherein the region setting unit sets a small region among the plurality of small regions in the powder bed corresponding to the first molding portion, which includes a portion that overlaps with the portion of the powder bed corresponding to the second molding portion that is scheduled to be irradiated.

8. The system includes a temperature detection unit for detecting the temperature of the powder bed, The three-dimensional molding apparatus according to claim 1 or 2, wherein the preheating control unit controls the output of the preheating unit based on the detection result of the temperature detection unit.

9. The three-dimensional molding apparatus according to claim 1 or 2, wherein the preheating section is arranged to face the main surface with the powder bed in between.

10. A preheating device for preheating powder material that will be sintered or melted to form an object when irradiated with an energy beam, A preheating unit capable of preheating each of several regions in the powder bed formed by the powder material supplied to the main surface of the table at different temperatures, The system includes a controller that controls the output of the preheating unit, The aforementioned controller, A region division unit that divides the powder bed into multiple small regions, A region setting unit sets a region containing the portion to be irradiated with the energy beam as the first region, and sets at least one of the other regions not set as the first region as the second region. The system includes a preheating control unit that controls the output of the preheating unit so that the first region and the second region are preheated at different temperatures from each other, The preheating control unit controls the output of the preheating unit so that the first region is preheated to a temperature equal to or greater than the pre-sintering temperature of the powder material, and the second region is preheated to a temperature lower than the pre-sintering temperature.

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