Recoater device and additive manufacturing device

Abstract

To restrain the degradation of quality of a modeled object.SOLUTION: A recoater device 20 for spreading to smooth out a surface 2a of a powder bed A placed on a main surface 5a of a table 5 comprises: a recoater 21 placed on the surface 2a; and a recoater device part 51 that holds the recoater 21 to relatively move the recoater 21 with respect to the surface 2a in an X-direction along the main surface 5a. The recoater 21 has a core material 31 that includes a tip end surface 32 that runs along the main surface 5a and extends in the Y-direction that crosses the X-direction, and is configured by a material that receives a reactive force from a modeled object 3 formed on the main surface 5a to be elastically deformed, and a metal plate 41 that covers at least the tip end surface 32 and is placed so as to face the surface 2a, and is configured by a material harder than the core material 31.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a recoater apparatus and an additive manufacturing apparatus. [Background technology]

[0002] Conventionally, additive manufacturing apparatuses that manufacture shaped objects by solidifying a powder material are known (see, for example, Patent Documents 1 and 2). Such additive manufacturing apparatuses include, for example, a table that supports a powder bed containing powder, an irradiation device that irradiates the powder bed on the table with an energy beam, and a recoater device that smooths the surface of the powder bed. The recoater device has a recoater that includes a contact surface that contacts the surface of the powder bed, and a recoater movement mechanism that moves the recoater horizontally over the surface of the powder bed. The recoater may be, for example, a metal recoater or a soft recoater made of rubber, silicone, or the like. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-127651 [Patent Document 2] Japanese Patent Application Publication No. 2018-122479 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when a metal recoater is used, the pressing force from the recoater is likely to deform the object as it moves across the surface of the powder bed. On the other hand, when a soft recoater such as a rubber or silicone recoater is used, the surface of the recoater is likely to be scratched when pressed against the object, and spatter generated during energy beam irradiation is also likely to adhere to the recoater. If the surface shape of the recoater is deformed due to such scratches or spatter adhesion, the shape corresponding to the recoater surface may be reflected in the object when the recoater performs its coating operation. Therefore, with the above-mentioned recoaters, the object may be formed into an unintended shape, which may result in a deterioration in the quality of the object.

[0005] The present disclosure describes a recoater apparatus and an additive manufacturing apparatus that can suppress deterioration in the quality of a molded object. [Means for solving the problem]

[0006] A recoater device according to one embodiment of the present disclosure includes a holder that moves the recoater relative to a surface in a first direction along the main surface, and the recoater includes a tip surface that extends along the main surface and in a second direction that intersects the first direction, a core material made of a material that elastically deforms when subjected to a reaction force from a structure formed on the main surface, and a cover layer that covers at least the tip surface and is arranged to face the surface, and is made of a material harder than the core material.

[0007] In the above-described recoater device, the core material of the recoater is made of an elastic material that elastically deforms when subjected to a reaction force from the object. Therefore, when the recoater contacts the object while moving over the surface of the powder bed, it can overcome the object without deforming it. Furthermore, the tip surface of the core material is covered with a cover layer that is harder than the core material. This hard cover layer is less susceptible to deformation of the surface shape due to scratches and spatter adhesion. Therefore, by arranging the cover layer facing the surface of the powder bed, deformation of the contact surface of the recoater (i.e., the outer surface of the cover layer) due to scratches and spatter adhesion can be suppressed. This prevents the surface shape of the recoater from being reflected in the object during the recoater coating operation. Therefore, the above-described recoater device can prevent the object from being formed in an unintended shape, thereby suppressing deterioration in the quality of the object.

[0008] In some embodiments, the cover layer may be a metal plate made of a metal material. The metal plate has relatively high hardness and heat resistance. Therefore, when high-temperature spatter is pressed against the metal plate, the spatter can be prevented from being embedded in and adhering to the metal plate. Therefore, the above configuration can more reliably prevent the cover layer from being deformed in surface shape due to the formation of scratches and the adhesion of spatter.

[0009] In some embodiments, the cover layer may have enough rigidity to deform when subjected to a reaction force from the shaped object. In this case, the cover layer can deform together with the core material when subjected to a reaction force from the shaped object. This reduces the pressing force applied to the shaped object by the recoater compared to when the cover layer does not deform. This more reliably prevents deformation of the shaped object due to movement of the recoater. Furthermore, the cover layer can return to its original shape in response to elastic deformation of the core material, ensuring stable application by the recoater.

[0010] In some embodiments, the recoater may further have a pair of side surfaces aligned in the first direction, and the cover layer may have a tip surface cover portion that covers the tip surface and a pair of side surface cover portions that extend from the tip surface and cover the pair of side surfaces. In this case, the cover layer can be easily attached to the core material by a simple operation of wrapping and fixing the cover layer along the shape of the core material.

[0011] In some embodiments, the cover layer may have a plurality of slits arranged side by side at intervals in the second direction and extending from the tip surface cover portion to the pair of side surface cover portions. In this case, the portions of the cover layer between the plurality of slits are each independently deformable. Therefore, when the recoater receives a reaction force from the model in the first direction, only the portion of the cover layer that receives the reaction force can be deformed in the first direction. In this case, the pressing force applied to the model by the recoater can be more effectively reduced compared to when the entire cover layer deforms in the first direction, thereby more reliably preventing deformation of the model due to movement of the recoater.

[0012] In some embodiments, the cover layer may be removably attached to the core material, which improves maintainability by allowing only the cover layer to be replaced if the cover layer is damaged, without the need to replace the entire recoater.

[0013] In some embodiments, the cover layer has an outer surface facing away from the tip surface, and the outer surface may be curved so as to bulge toward the surface when viewed from the second direction. In this case, it is possible to prevent the recoater from getting caught on the modeled object when the recoater moves over the surface of the powder bed. As a result, it is possible to more reliably prevent deformation of the modeled object caused by the movement of the recoater.

[0014] An additive manufacturing apparatus according to one aspect of the present disclosure includes a chamber, a table disposed in the chamber and supporting a powder bed containing powder, an irradiation device that irradiates the powder on the table with an energy beam, and any of the recoater devices described above that is disposed in the chamber and smooths the surface of the powder bed.

[0015] The layered manufacturing apparatus includes any one of the recoater devices described above. Therefore, the layered manufacturing apparatus can prevent a model from being formed in an unintended shape, thereby preventing a decrease in the quality of the model. [Effects of the Invention]

[0016] According to some aspects of the present disclosure, there are provided a recoater apparatus and an additive manufacturing apparatus that can suppress deterioration in the quality of a molded object. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a cross-sectional view showing an additive manufacturing apparatus according to one embodiment. [Figure 2] FIG. 2 is a perspective view showing a recoater device included in the layered manufacturing apparatus of FIG. [Figure 3] FIG. 3 is a side view showing the recoater device. [Figure 4] FIG. 4 is a cross-sectional view showing a recoater device. [Figure 5] FIG. 5 is an exploded perspective view showing a recoater provided in the recoater device. [Figure 6] Fig. 6(a) is a perspective view showing the metal plate of the recoater, and Fig. 6(b) is a plan view showing the metal plate of Fig. 6(a) in an expanded state. [Figure 7] FIG. 7 is an enlarged plan view of part P in FIG. 6(b). [Figure 8] 8(a) is a cross-sectional view showing the recoater climbing over the protruding portion of the model, and FIG. 8(b) is a cross-sectional view of the recoater after climbing over the protruding portion of the model. [Figure 9]9(a) is a side view showing a recoater apparatus according to Comparative Example 1. FIG. 9(b) is a side view showing a recoater apparatus according to Comparative Example 2. [Figure 10] Fig. 10(a) is a side view showing a recoater apparatus according to Comparative Example 3. Fig. 10(b) is a side view showing a recoater apparatus according to Comparative Example 4. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the description of the drawings, the same elements are designated by the same reference numerals, and duplicated description will be omitted.

[0019] The additive manufacturing apparatus shown in FIG. 1 is a so-called 3D (three-dimensional) printer. In the following description, the additive manufacturing apparatus will be simply referred to as a "modeling apparatus 1." The modeling apparatus 1 partially applies energy to powder 2 arranged in layers to sinter or melt the powder 2. The modeling apparatus 1 manufactures a three-dimensional object 3 by repeatedly sintering or melting the powder 2.

[0020] The molded object 3 is, for example, a machine part. The molded object 3 may also be other structures. The material of the powder 2 is, for example, a metal. The powder 2 may be, for example, a metal powder such as titanium-based metal powder, Inconel (registered trademark) powder, aluminum powder, or stainless steel powder. The material of the powder 2 is not limited to a metal, and may be other materials such as ceramic or resin. The powder 2 may contain carbon fiber and resin, such as CFRP (Carbon Fiber Reinforced Plastics), or may contain other materials. For example, the powder 2 may contain a conductive material having electrical conductivity.

[0021] The modeling apparatus 1 includes a vacuum chamber 4 (chamber), a table 5, a lifting device 6, a powder supplying device 7, an irradiation device 8, a modeling tank 10, and a controller 18. The vacuum chamber 4 is a container whose interior can be placed in a vacuum (low pressure) state. A vacuum pump is connected to the vacuum chamber 4. The vacuum chamber 4 houses the table 5, the lifting device 6, the powder supplying device 7, and the modeling tank 10. The table 5 is disposed in the modeling tank 10 within the vacuum chamber 4. The table 5 has, for example, a plate shape. In a plan view, the shape of the table 5 is, for example, circular. The shape of the table 5 is not limited to circular and may be other shapes such as rectangular.

[0022] A substrate 15 is placed on the table 5. Powder 2, which is the material for the object 3, is placed on the substrate 15. Therefore, the table 5 supports the powder 2 and the object 3 via the substrate 15. The powder 2 on the substrate 15 is placed, for example, in layers, in multiple batches. The table 5 is movable in the Z direction within the modeling tank 10. The table 5 is then sequentially lowered according to the number of layers of powder 2. The side wall 10a of the modeling tank 10 guides the movement of the table 5. The shape of the side wall 10a corresponds to the outer shape of the table 5. For example, when the table 5 is a disk, the shape of the area surrounded by the side wall 10a is cylindrical. The side wall 10a of the modeling tank 10 and the table 5 form a storage section that stores the powder 2 and the object 3. The table 5 may form the bottom of the modeling tank 10.

[0023] The lifting device 6 raises and lowers the table 5. As the lifting device 6 raises and lowers the table 5, the substrate 15 on the table 5, the powder 2 on the substrate 15, and the molded object 3 rise and fall. The lifting device 6 includes, for example, a rack-and-pinion drive mechanism. These mechanisms allow the lifting device 6 to move the table 5 in the Z direction. The Z direction may be a direction perpendicular to the table, for example, a direction along the vertical direction. In the following description, the terms "upper" and "lower" are used based on the state in which the Z direction is aligned with the vertical direction. The term "lower" refers to the lower side in the vertical direction, and the term "upper" refers to the upper side in the vertical direction.

[0024] The lifting device 6 includes a vertical member 6a (rack) and a drive source 6b. The vertical member 6a is a rod-shaped member connected to the back surface of the table 5 and extending downward. The drive source 6b drives the vertical member 6a. An electric motor, for example, is used as the drive source 6b. A pinion is provided on the output shaft of the electric motor. Teeth that mesh with the pinion are provided on the side of the vertical member 6a. When the electric motor is driven, the pinion rotates. Power is transmitted by the rotation of the pinion. As a result, the vertical member 6a moves in the vertical direction. When the rotation of the electric motor is stopped, the vertical member 6a is positioned. As a result, the position of the table 5 in the Z direction is determined, and the position of the table 5 is maintained. The lifting device 6 is not limited to a rack-and-pinion drive mechanism. For example, the lifting device 6 may include other drive mechanisms such as a ball screw or a cylinder.

[0025] The powder supplying device 7 includes a pair of raw material tanks 11. The pair of raw material tanks 11 are storage units for storing the raw material powder 2. The pair of raw material tanks 11 are disposed in a position above the table 5 within the vacuum chamber 4. The pair of raw material tanks 11 are disposed, for example, on both sides of an electron beam irradiation area D by the irradiation device 8 in the X direction (first direction) intersecting the Z direction. A discharge port is provided at the bottom of each raw material tank 11. The discharge port of each raw material tank 11 is continuous, for example, in the Y direction (second direction). The Y direction is a direction intersecting the X direction and the Z direction. The X direction and the Y direction may be directions along the main surface 5a of the table 5, or may be directions along the horizontal direction, for example. Below each raw material tank 11, a protruding plate 12 is provided, extending laterally from the upper end of the side wall 10a of the modeling tank 10. The protruding plate 12 forms a plane along the X direction and the Y direction around the table 5.

[0026] The powder supply device 7 includes a recoater device 20, which is a powder application mechanism that levels the powder 2. The recoater device 20 is disposed above the table 5 and the extension plate 12 and is movable in the X direction. By moving in the X direction, the recoater device 20 scrapes the powder 2 deposited on the extension plate 12 onto the table 5. Furthermore, by moving in the X direction, the recoater device 20 levels the surface 2a (top surface) of the top layer of the stack of powder 2 on the table 5. Hereinafter, the "stack of powder 2" will be referred to as powder bed A. The recoater device 20 moves in the X direction while in contact with the surface 2a of the powder bed A, thereby leveling the height of the surface 2a. The recoater device 20 may include, for example, a rack-and-pinion drive mechanism. The recoater device 20 may include, as a drive mechanism, a guide rail, an endless belt, a ball screw, an electric motor, a cylinder, or the like.

[0027] The irradiation device 8 is, for example, an electron beam irradiation device including an electron gun that irradiates an electron beam (electron beam) as an energy beam. In FIG. 1, the irradiation region D through which the emitted electron beam passes is indicated by a two-dot chain line. The electron beam emitted from the electron gun is irradiated into the vacuum chamber 4. The electron beam heats the powder 2. In other words, the irradiation device 8 imparts energy to the powder 2. As a result, the powder 2 is heated and melts or sinters. The irradiation device 8 is a powder solidification unit that solidifies the powder 2 in the powder bed A. The irradiation device 8 can also be said to be an energy imparting unit that imparts energy to the powder bed A.

[0028] The irradiation device 8 may include a coil device that controls the irradiation of the electron beam. The coil device may include, for example, an aberration coil, a focus coil, and a deflection coil. The aberration coil is placed around the electron beam emitted from the electron gun and focuses the electron beam. The focus coil is placed around the electron beam emitted from the electron gun and corrects deviations in the focus position of the electron beam. The deflection coil is placed around the electron beam emitted from the electron gun and adjusts the irradiation position of the electron beam. The deflection coil performs electromagnetic beam deflection. Electromagnetic beam deflection allows for a faster scanning speed during electron beam irradiation than mechanical beam deflection. The electron gun and coil unit are located above the vacuum chamber 4. The electron beam emitted from the electron gun is converged by the coil unit, the focus position is corrected, and the scanning speed is controlled until it reaches the irradiation position of the powder 2.

[0029] The controller 18 is a control unit that controls the overall operation of the modeling apparatus 1. The controller 18 is a computer that includes hardware such as a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory), and software such as programs stored in the ROM. The controller 18 includes an input signal circuit, an output signal circuit, a power supply circuit, etc. The controller 18 includes a calculation unit and a memory. The controller 18 is electrically connected to the irradiation device 8, the powder supply device 7, and the lifting device 6. The controller 18 can generate various command signals. The memory can store data required for various controls.

[0030] The controller 18 transmits a command signal to the irradiation device 8 to control the irradiation timing, irradiation position, etc. of the electron beam (irradiation control). The controller 18 controls the irradiation of the electron beam when melting the powder 2. The controller 18 transmits a command signal to the powder supply device 7 to control the supply timing and supply amount of the powder 2. The controller 18 may transmit a command signal to the recoater device 20 to control the operation timing, etc. of the recoater 21.

[0031] Next, the configuration of the recoater apparatus 20 will be described in more detail. As shown in FIGS. 2 and 3, the recoater apparatus 20 includes a recoater 21 and a recoater moving mechanism 22. The recoater 21 is plate-shaped and extends in the Y direction. The recoater moving mechanism 22 is disposed adjacent to the recoater 21 in the X direction and holds the recoater 21. Like the recoater 21, the recoater moving mechanism 22 also extends in the Y direction. The length of the recoater moving mechanism 22 in the Y direction is, for example, longer than the length of the recoater 21 in the Y direction. The length of the recoater 21 in the Y direction corresponds to, for example, the overall length of the table 5 (see FIG. 1) in the Y direction. The recoater moving mechanism 22 moves in the X direction relative to the surface 2a of the powder bed A while holding the recoater 21.

[0032] The recoater 21 includes a core material 31 and a metal plate 41 (cover layer) covering the core material 31. The core material 31 is a plate-shaped member with its longitudinal direction in the Y direction and its transverse direction in the Z direction. The thickness of the recoater 21 in the X direction is, for example, approximately 10 mm. As shown in FIG. 3 , the recoater 21 is disposed upright on the surface 2a of the powder bed A. The core material 31 is made of a heat-resistant and elastic material such as rubber or silicone. The core material 31 made of such a flexible material has a lower Young's modulus than the object 3 formed by solidifying metal powder. Therefore, when the core material 31 is pressed against the object 3 while moving in the X direction, it easily deforms due to the reaction force from the object 3. This deformation of the core material 31 reduces the pressing force applied by the recoater 21 to the object 3.

[0033] 3 and 4, the core 31 has a tip surface 32 and a pair of side surfaces 33, 34 extending in a direction intersecting the tip surface 32. The tip surface 32 is a lower surface located at the lower end of the core 31 in the Z direction, and extends continuously along the Y direction. When the recoater 21 is placed on the surface 2a of the powder bed A, the tip surface 32 faces the surface 2a in the Z direction via the metal plate 41. "The tip surface 32 faces the surface 2a in the Z direction" means that the normal to the tip surface 32 and the normal to the surface 2a include a Z-direction component and are arranged so as to intersect each other.

[0034] The tip surface 32 has, for example, an arc shape curved downward toward the surface 2a when viewed from the Y direction. The shape of the tip surface 32 when viewed from the Y direction is not limited to an arc shape and may be another shape, such as an ellipse. The tip surface 32 may be, for example, a plane along the XY plane. The pair of side surfaces 33, 34 are disposed at both ends of the core material 31 in the X direction and extend upward from the tip surface 32. Each of the pair of side surfaces 33, 34 is, for example, a plane extending along the YZ plane. The side surface 33 is disposed in a position facing the recoater movement mechanism 22 in the X direction. The side surface 34 is disposed on the opposite side of the recoater movement mechanism 22 in the X direction.

[0035] The metal plate 41 is a thin plate made of a metal material such as stainless steel, iron, or aluminum. Therefore, the metal plate 41 has a higher hardness than the core material 31. For example, the metal plate 41 may have a higher hardness than the solidified object 3. The higher the hardness of the metal plate 41, the less likely the surface shape of the metal plate 41 will deform, and the higher its resistance to scratches and other damage. "Hardness" is expressed by the magnitude of the resistance force generated when the surface of a material is pressed, and can be measured by various known hardness tests (e.g., Vickers hardness test, etc.). The hardness of the metal plate 41 can be determined using the measured value obtained by such a hardness test or its equivalent.

[0036] On the other hand, the metal plate 41 has a certain degree of flexibility. Specifically, the metal plate 41 has enough rigidity to be deformed by the reaction force received from the object 3 while the recoater 21 is moving. Therefore, when the metal plate 41 receives a reaction force in the X direction from the object 3, the metal plate 41 is deformed in the X direction by the reaction force. Because the metal plate 41 has such rigidity, the metal plate 41 is bent in the X direction together with the core material 31 in response to the reaction force from the object 3. As a result, the pressing force from the recoater 21 to the object 3 is reduced, and the recoater 21 can overcome the object 3 without deforming it. Furthermore, the flexibility of the metal plate 41 improves the ease of assembling the metal plate 41 to the core material 31. In this embodiment, stainless steel is used as the material for the metal plate 41, which has both hardness and flexibility. In addition, in this embodiment, the thickness of the metal plate 41 is set to be sufficiently thin in consideration of flexibility. The thickness of the metal plate 41 is sufficiently smaller than the thickness of the core material 31, and is set in the range of 0.05 mm to 0.1 mm, for example.

[0037] The metal plate 41 is arranged to cover at least the tip surface 32 of the core material 31. In this embodiment, the metal plate 41 is arranged to cover from the tip surface 32 to the pair of side surfaces 33, 34. As a result, the metal plate 41 has a U-shaped bent shape when viewed from the X direction. The metal plate 41 has a tip surface cover portion 42 that covers the tip surface 32 and a pair of side surface cover portions 43, 44 that cover the pair of side surfaces 33, 34. The tip surface cover portion 42 includes an outer surface 42a facing the surface 2a of the powder bed A and an inner surface 42b facing the tip surface 32 of the core material 31. When viewed from the X direction, the outer surface 42a and the inner surface 42b have an arc-like shape that curves downward to follow the shape of the tip surface 32.

[0038] The inner surface 42b of the tip surface cover part 42 may be in contact with the tip surface 32 without any gap, or may be disposed with a gap from the tip surface 32. The outer surface 42a of the tip surface cover part 42 faces the surface 2a of the powder bed A in the Z direction. The outer surface 42a facing the surface 2a in the Z direction means that the normal to the outer surface 42a and the normal to the surface 2a include a Z-direction component and intersect with each other. Specifically, when the recoater 21 is disposed on the surface 2a of the powder bed A, the outer surface 42a abuts against the surface 2a in the Z direction. The recoater 21 moves over the surface 2a while the outer surface 42a abuts against the surface 2a, thereby smoothing the surface 2a flat. The outer surface 42a is configured as the abutment surface S1 of the recoater 21 with respect to the surface 2a.

[0039] The side cover portion 43 extends from the tip surface cover portion 42 and is arranged to cover the side surface 33 of the core material 31. The side surface cover portion 43, for example, covers the entire surface of the side surface 33. The side surface cover portion 43, for example, is in contact with the side surface 33 of the core material 31 and the recoater moving mechanism 22 without any gaps. The side surface cover portion 43 is sandwiched between the side surface 33 of the core material 31 and the recoater moving mechanism 22. The side surface cover portion 44 extends from the tip surface cover portion 42 and is arranged to cover the side surface 34 of the core material 31. In this embodiment, the side surface cover portion 44 covers, for example, a portion of the side surface 34 excluding the upper end portion, but may cover the entire surface of the side surface 34. The side surface cover portion 44, for example, is in contact with the side surface 34 of the core material 31 without any gaps.

[0040] As shown in FIGS. 2 to 4, the recoater moving mechanism 22 has a recoater device unit 51 (holder) that holds the recoater 21. The recoater device unit 51 includes a rectangular plate-shaped base 52 extending in the Y direction and a pair of wall portions 53 and 54 extending downward from the lower end of the base 52. The base 52 includes a lower surface 52a located at the lower end of the base 52 in the Z direction and a pair of side surfaces 52b and 52c extending upward from the lower surface 52a. As shown in FIG. 4, the lower surface 52a is a plane that faces the surface 2a of the powder bed A in the Z direction and is located above the tip surface cover 42. The lower surface 52a is located, for example, at the center of the recoater 21 in the Z direction or above this center. The pair of side surfaces 52b and 52c are planes perpendicular to the lower surface 52a and are located at both ends of the base 52 in the X direction. Therefore, the pair of side surfaces 52b, 52c are aligned in the X direction. The side surface 52b is disposed in a position facing the side surface cover portion 43 in the X direction. The side surface 52c is disposed in a position opposite the recoater 21 in the X direction.

[0041] The pair of walls 53, 54 protrude downward from both ends of the lower surface 52a in the Y direction. The pair of walls 53, 54 are, for example, rectangular plate-shaped along the XZ plane. The pair of walls 53, 54 are located outside the recoater 21 in the Y direction. Therefore, the distance between the pair of walls 53, 54 in the Y direction is wider than the width of the recoater 21 in the Y direction. As described above, the lower surface 52a of the base 52 is located at the center of the recoater 21 in the Z direction or above the center. Therefore, when the recoater 21 receives a reaction force in the X direction from the shaped object 3, it can deform in the X direction without interfering with the recoater device unit 51. In other words, the recoater 21 is allowed to deform in the X direction in the space V (see FIG. 4 ) surrounded by the pair of walls 53, 54 and the lower surface 52a of the base 52.

[0042] The recoater 21 is removably attached to the recoater device unit 51 by, for example, a fastening member 70 (see FIG. 2). The fastening member 70 includes, for example, two fixing bolts 71 and one fixing plate 72. The two fixing bolts 71 are inserted in the X direction through the base 52 of the recoater device unit 51 and the recoater 21 at positions spaced apart in the Y direction. The base 52 is formed with two insertion holes 55 (see FIG. 4), through which the two fixing bolts 71 are respectively inserted. As shown in FIGS. 4 and 5, the core material 31 of the recoater 21 is also formed with two insertion holes 35, through which the two fixing bolts 71 are respectively inserted.

[0043] As shown in Fig. 5, four insertion holes 45 are formed in the metal plate 41 of the recoater 21. One fixing bolt 71 is inserted into two of the insertion holes 45, and the other fixing bolt 71 is inserted into the other two insertion holes 45. As shown in Figs. 3 and 4, the head 71a of each fixing bolt 71 is disposed on the side surface 52c of the base 52, and the tip (thread tip) of each fixing bolt 71 protrudes in the X direction from the side cover portion 44 of the recoater 21. A fixing plate 72 is screwed onto the tip of each fixing bolt 71 protruding from the side cover portion 44. This fixes the recoater device unit 51, the metal plate 41, and the core material 31 to one another.

[0044] When attaching the recoater 21 to the recoater device unit 51, first, as shown in FIG. 5, the metal plate 41 is bent into a U-shape and attached so that it is wrapped around the core material 31. Then, as shown in FIGS. 3 and 4, two fixing bolts 71 are inserted from the base 52 of the recoater device unit 51 through the core material 31 and the metal plate 41. Then, the tip ends of each fixing bolt 71 protruding from the metal plate 41 are screwed into the fixing plate 72, thereby sandwiching the base 52, the core material 31, and the metal plate 41 in the X direction between the heads 71a of each fixing bolt 71 and the fixing plate 72. This fixes the recoater device unit 51, the core material 31, and the metal plate 41 to one another. Furthermore, by loosening the fastening of each fixing bolt 71, the recoater device unit 51, the core material 31, and the metal plate 41 can be detached from one another. In this way, the recoater device unit 51, the core material 31, and the metal plate 41 are attached so as to be detachable from one another.

[0045] As shown in FIGS. 6(a) and 6(b), a plurality of slits 47 are formed in the metal plate 41. FIG. 6(a) shows the metal plate 41 bent into a U-shape, and FIG. 6(b) shows the metal plate 41 unfolded into a flat state. As shown in FIG. 6(b), the metal plate 41 in the unfolded state has a rectangular shape with direction D1 as the longitudinal direction and direction D2 as the lateral direction. Direction D1 coincides with the Y direction. Direction D2 may be a direction including the X direction or the Z direction. Each slit 47 is formed in the center of direction D2 of the metal plate 41. Each slit 47 extends linearly along direction D2 and is arranged at equal intervals along direction D1. Each slit 47 has, for example, the same dimensions and shape as one another.

[0046] Figure 7 shows an enlarged view of portion P in Figure 6(b). As shown in Figure 7, each slit 47 is continuously formed from the tip surface cover portion 42 to the pair of side surface cover portions 43, 44. Each slit 47 extends linearly in direction D2 from the side surface cover portion 43 through the tip surface cover portion 42 to a position where it reaches the side surface cover portion 44. The width of each slit 47 in direction D1 is set as small as possible from the viewpoint of ensuring the area of ​​the metal plate 41. The width of each slit 47 in direction D1 is smaller than the arrangement pitch of each slit 47 in direction D1. The arrangement pitch of each slit 47 in direction D1 is, for example, approximately 1 mm.

[0047] The metal plate 41 has a plurality of divided portions P1 divided in the direction D1 by the formation of a plurality of slits 47. Because the divided portions P1 are separated from one another in the direction D1 at the formation positions of the slits 47, they can be deformed independently of one another when subjected to an external force. Therefore, when a divided portion P1 is deformed by an external force, the other divided portions P1 that are not subjected to the external force either do not deform or deform less than the divided portion P1. As shown in FIG. 2 , when the recoater 21 is held by the recoater device unit 51, each slit 47 and each divided portion P1 is located below the lower surface 52a of the recoater device unit 51. Therefore, when one of the divided portions P1 receives a reaction force in the X direction from the object 3, the divided portion P1 that receives the reaction force is bent and deformed in the X direction in the space V (see FIG. 4 ) below the lower surface 52a. In this embodiment, each slit 47 is configured as a gap having a width in the direction D1. However, it may also be configured as a slit that does not have a width in the direction D1. In this case, the divided portions P1 contact each other in the direction D1.

[0048] In the recoater apparatus 20 described above, the recoater 21 held by the recoater moving mechanism 22 moves horizontally over the powder bed A in the X direction. As the recoater 21 moves, the contact surface S1 of the recoater 21 moves over the surface 2a of the powder bed A while contacting the surface 2a. This makes the surface 2a of the powder bed A flat and level. The irradiation device 8 irradiates the powder 2 with an electron beam in accordance with the shape of one layer of the object 3. The powder 2 irradiated with the electron beam is melted or sintered, thereby forming the shape of one layer of the object 3. Thereafter, the recoater 21 moves horizontally over the surface 2a of the powder bed A again, thereby placing a new layer of powder 2 on the formed object 3. This operation is repeated to obtain the final object 3.

[0049] As shown in FIG. 8(a), when the recoater 21 moves in the X direction over the surface 2a of the powder bed A, it may receive a reaction force in the X direction from a protruding portion P3 of the model 3. The protruding portion P3 may be, for example, a portion of one layer of the model 3 that is thicker than other portions. In this embodiment, the core material 31 of the recoater 21 is made of a flexible material such as rubber or silicone. Therefore, the recoater 21 easily deforms when subjected to the reaction force from the protruding portion P3. Furthermore, the metal plate 41 covering the core material 31 has enough rigidity to deform when subjected to the reaction force from the protruding portion P3, and includes multiple divided portions P1 separated by multiple slits 47.

[0050] Therefore, when a reaction force from the protruding portion P3 is applied to the divided portions P1 of the metal plate 41, one or more of the divided portions P1 to which the reaction force is applied are bent in the X direction together with the core material 31. On the other hand, the other divided portions P1 to which the reaction force is not applied are not deformed or are deformed less than the divided portions P1 to which the reaction force is applied. As a result, when the recoater 21 receives a reaction force from the protruding portion P3 of the shaped object 3, it is bent in the X direction at the location where the reaction force is applied and moves over the protruding portion P3. Thereafter, as shown in FIG. 8(b), after moving over the protruding portion P3, the recoater 21 returns to its original shape. In other words, the core material 31 elastically returns, and the metal plate 41 also returns to its original shape in response to this return movement of the core material 31.

[0051] Next, the effects achieved by the recoater apparatus 20 and the modeling apparatus 1 according to this embodiment will be described together with the problems of the comparative example.

[0052] FIG. 9(a) shows a recoater apparatus 120 according to Comparative Example 1. The recoater apparatus 120 differs from the recoater apparatus 20 according to this embodiment in that it includes a metal recoater 121. The recoater 121 is entirely made of metal and has high rigidity. Therefore, when the recoater 121 held by the recoater movement mechanism 122 moves in the X direction over the powder bed A and the model 3 is pressed against the recoater 121, a large pressing force is applied from the recoater 121 to the model 3. As a result, the model 3 may be significantly deformed as the recoater 121 moves. Therefore, in the recoater apparatus 120, the model 3 may be deformed into an unintended shape, which may result in a deterioration in the quality of the model 3.

[0053] 9(b) shows a recoater apparatus 220 according to Comparative Example 2. The recoater apparatus 220 differs from the recoater apparatus 20 according to this embodiment in that it includes a recoater 221 having a silicone blade 221a. Because the blade 221a is flexible, when the recoater 221 receives a reaction force from the model 3 while moving in the X direction on the surface 2a of the powder bed A, the blade 221a easily deforms in the X direction. When the blade 221a deforms in this way, the pressing force applied from the blade 221a to the model 3 is reduced, thereby preventing the model 3 from being significantly deformed as the recoater 221 moves.

[0054] However, if the blade 221a is made of such a soft material, the surface of the blade 221a is likely to be scratched when the blade 221a is pressed against the object 3. Furthermore, with such a material, spatter generated when the powder 2 is irradiated with the electron beam is likely to adhere to the surface of the blade 221a. Spatter is a large-diameter clump of powder 2 that does not completely melt into the object 3 and scatters. When such spatter, which is a clump of metal, is pressed against the blade 221a, the spatter is likely to be embedded in the surface of the blade 221a. If such scratches or spatter adhesion occur on the contact surface S221 of the blade 221a with the surface 2a of the powder bed A (i.e., the surface of the blade 221a that contacts the surface 2a of the powder bed A), unevenness is formed on the contact surface S221, and the object 3 may also have a shape corresponding to the contact surface S221.

[0055] For example, if the contact surface S221 of the blade 221a is scratched by contact with the object 3, a groove may be formed on the contact surface S221, and a protrusion corresponding to the groove may be formed on the object 3. Furthermore, if spatter adheres to the contact surface S221 of the blade 221a, a protrusion may be formed on the contact surface S221, and a groove corresponding to the protrusion may be formed on the object 3. As a result, the object 3 may be formed into an unintended shape. Therefore, in the recoater device 220, the quality of the object 3 may be degraded. Note that when forming the shape of one layer of the object 3, spatter may remain on the shape of that layer. In this state, when powder 2 for the next layer of the object 3 is supplied and the recoater 221 moves over the powder 2, the remaining spatter may adhere to the contact surface S221 of the blade 221a. Alternatively, spatters scattered when the powder 2 is irradiated with the electron beam may directly adhere to the contact surface S221 of the blade 221a.

[0056] FIG. 10(a) shows a recoater apparatus 320 according to Comparative Example 3. The recoater apparatus 320 differs from the recoater apparatus 20 according to this embodiment in that it includes a recoater 321 having a rubber tube 321a. Like the blade 221a, the tube 321a is flexible, and therefore scratches or spatter adhesion are likely to occur on the contact surface S321 of the tube 321a. Therefore, even in the recoater apparatus 320, the model 3 may be formed into an unintended shape, which may result in a deterioration in the quality of the model 3. FIG. 10(b) shows a recoater apparatus 420 according to Comparative Example 4. The recoater apparatus 420 differs from the recoater apparatus 20 according to this embodiment in that it includes a brush recoater 421. However, the brush recoater 421 is prone to unintended scattering of powder 2 when moving over the powder bed A. Therefore, in the recoater apparatus 420, the flatness of the surface 2a of the powder bed A is likely to vary, and the quality of the model 3 is likely to deteriorate.

[0057] In the recoater apparatus 20 according to this embodiment, the core 31 of the recoater 21 is made of an elastic material that elastically deforms when subjected to a force acting in the X direction, for example. Therefore, when the recoater 21 abuts against the protruding portion P3 of the object 3 while moving over the surface 2a of the powder bed A, it receives a reaction force in the X direction from the protruding portion P3 and elastically deforms, thereby moving over the object 3 without deforming it. Furthermore, the tip surface 32 of the core 31 is covered with a hard metal plate 41. Such a hard metal plate 41 is less susceptible to deformation of its surface shape due to scratches and spatter adhesion. Therefore, by arranging the metal plate 41 facing the surface 2a of the powder bed A, it is possible to prevent the shape of the contact surface S1 of the recoater 21 (i.e., the outer surface 42a of the metal plate 41) that abuts against the surface 2a from becoming uneven due to scratches or spatter adhesion. This prevents the shape of the surface of the recoater 21 from being reflected on the model 3 when the recoater 21 performs a coating operation. Therefore, the recoater device 20 according to this embodiment prevents the model 3 from being formed in an unintended shape, thereby preventing a deterioration in the quality of the model 3.

[0058] In this embodiment, a metal plate 41 covers the core material 31 of the recoater 21. The metal plate 41 has a relatively high hardness and heat resistance. Therefore, when high-temperature spatter is pressed against the metal plate 41, it is possible to prevent the spatter from being embedded in and adhering to the metal plate 41.

[0059] In this embodiment, the metal plate 41 has enough rigidity to be deformed when it receives a reaction force, for example, in the X direction, from the protruding portion P3 of the object 3. In this case, the metal plate 41 can deform in the X direction together with the core material 31 when it receives a reaction force from the protruding portion P3 of the object 3. Therefore, the pressing force applied from the recoater 21 to the object 3 can be reduced compared to when the metal plate 41 does not deform. This more reliably prevents the object 3 from being deformed as the recoater 21 moves. Furthermore, the metal plate 41 can return to its original shape as the core material 31 elastically deforms, allowing the recoater 21 to perform a stable coating operation.

[0060] In this embodiment, the metal plate 41 has a tip surface cover portion 42 that covers the tip surface 32, and a pair of side surface cover portions 43, 44 that extend from the tip surface 32 and cover a pair of side surfaces. In this case, the metal plate 41 can be easily attached to the core material 31 by the simple task of wrapping and fixing the metal plate 41 along the shape of the core material 31.

[0061] In this embodiment, the metal plate 41 has a plurality of slits 47 formed therein that are spaced apart in the Y direction and extend from the tip surface cover portion 42 to the pair of side surface cover portions 43, 44. In this case, each divided portion P1 between each slit 47 is independently deformable. Therefore, when the recoater 21 receives a reaction force in the X direction from the protruding portion P3 of the object 3, only the divided portion P1 that receives the reaction force can be deformed in the X direction. In this case, the pressing force applied from the recoater 21 to the object 3 can be reduced more effectively than when the entire metal plate 41 deforms in the X direction, and therefore, deformation of the object 3 due to movement of the recoater 21 can be more reliably prevented.

[0062] In this embodiment, the metal plate 41 is removably attached to the core material 31. In this case, even if the metal plate 41 is damaged, it is not necessary to replace the entire recoater 21, but it is sufficient to replace only the metal plate 41, thereby improving maintainability.

[0063] In this embodiment, the metal plate 41 has an outer surface 42a facing away from the tip surface 32, and the outer surface 42a is curved so as to bulge toward the surface 2a of the powder bed A when viewed from the Y direction. In this case, it is possible to prevent the recoater 21 from getting caught on the model 3 when the recoater 21 moves over the surface 2a of the powder bed A. As a result, it is possible to more reliably prevent the model 3 from being deformed as the recoater 21 moves.

[0064] The present disclosure is not limited to the above-described embodiments, and various modifications are possible without departing from the spirit and scope of the present disclosure. For example, the movement direction of the recoater moving over the surface of the powder bed is not limited to the X direction, but may be other directions within the XY plane. In the above-described embodiments, the recoater moves over a stationary table to level the surface of the powder bed. However, the recoater may be stationary on a rotating table to level the surface of the powder bed. In this case, the recoater moves relative to the surface of the powder bed in the circumferential direction around the center of the disk-shaped table. The beam irradiated onto the powder by the irradiation device is not limited to an electron beam, and may be another energy beam (e.g., a laser).

[0065] In the above-described embodiment, the powder is a metal powder. However, even if the powder material is another material such as ceramic or resin, clumps of powder equivalent to sputtering may adhere to the recoater during beam irradiation, and the same effect as in the above-described embodiment can be obtained. In the above-described embodiment, the metal plate of the recoater covers the core material from the tip surface to two side surfaces, but the metal plate does not necessarily have to cover the side surfaces of the core material. Furthermore, the member covering the core material does not have to be a metal plate. The member covering the core material may be a thin plate made of a material other than metal (e.g., resin) as long as it is harder than the core material. The method of fixing the metal plate to the core material is not limited to screw fastening, and other fixing methods such as adhesive bonding may be used. [Explanation of symbols]

[0066] 1. Modeling equipment (additive manufacturing equipment) 2 powder 2a surface 4 Vacuum chamber (chamber) 5 tables 8 Irradiation device 20 Recoater device 21 Recoater 31 Core material 32 Tip surface 33,34 Side 41 Metal plate (cover layer) 42 Tip surface cover 42a Exterior 43,44 Side cover 47 Slit 51 Recoater device (holder) A powder bed

Claims

1. A recoater apparatus for leveling the surface of a powder bed disposed on a main surface of a table, comprising: a recoater positioned over the surface; a holder that holds the recoater and moves the recoater relative to the surface in a first direction along the main surface, The recoater is a core material including a tip surface extending along the main surface and in a second direction intersecting the first direction, the core material being made of a material that elastically deforms upon receiving a reaction force from a shaped object formed on the main surface; a cover layer that is arranged to cover at least the tip end surface and face the surface, and is made of a material harder than the core material; The core material is made of rubber or silicone.

2. 2. The recoater apparatus according to claim 1, wherein the cover layer is a metal plate made of a metal material.

3. The recoater apparatus according to claim 1 , wherein the cover layer has sufficient rigidity to be deformed when subjected to a reaction force from the object.

4. the recoater further has a pair of side surfaces aligned in the first direction, 4. The recoater apparatus according to claim 3, wherein the cover layer has a tip surface cover portion that covers the tip surface, and a pair of side surface cover portions that extend from the tip surface and cover the pair of side surfaces.

5. 5. The recoater apparatus according to claim 4, wherein the cover layer has a plurality of slits formed therein, the slits being spaced apart from one another in the second direction and extending from the tip surface cover portion to the pair of side surface cover portions.

6. 6. The recoater apparatus according to claim 1, wherein the cover layer is removably attached to the core material.

7. the cover layer has an outer surface facing away from the tip surface, 7. The recoater apparatus according to claim 1, wherein the outer surface is curved so as to bulge toward the front surface when viewed from the second direction.

8. A recoater apparatus for leveling the surface of a powder bed placed on a main surface of a table, comprising: a recoater positioned over the surface; a holder that holds the recoater and moves the recoater relative to the surface in a first direction along the main surface, The recoater is a core material including a tip surface extending along the main surface and in a second direction intersecting the first direction, the core material being made of a material that elastically deforms upon receiving a reaction force from a shaped object formed on the main surface; a cover layer that is arranged to cover at least the tip end surface and face the surface, and is made of a material harder than the core material; The cover layer has sufficient rigidity to be deformed by receiving a reaction force from the object.

9. A recoater apparatus for leveling the surface of a powder bed disposed on a main surface of a table, comprising: a recoater positioned over the surface; a holder that holds the recoater and moves the recoater relative to the surface in a first direction along the main surface, The recoater is a core material including a tip surface extending along the main surface and in a second direction intersecting the first direction, the core material being made of a material that elastically deforms upon receiving a reaction force from a shaped object formed on the main surface; a cover layer that is arranged to cover at least the tip end surface and face the surface, and is made of a material harder than the core material; The cover layer is removably attached to the core material.

10. A recoater apparatus for leveling the surface of a powder bed disposed on a main surface of a table, comprising: a recoater positioned over the surface; a holder that holds the recoater and moves the recoater relative to the surface in a first direction along the main surface, The recoater is a core material including a tip surface extending along the main surface and in a second direction intersecting the first direction, the core material being made of a material that elastically deforms upon receiving a reaction force from a shaped object formed on the main surface; a cover layer that is arranged to cover at least the tip end surface and face the surface, and is made of a material harder than the core material; the cover layer has an outer surface facing away from the tip surface, The recoater apparatus, wherein the outer surface is curved so as to bulge toward the front surface when viewed from the second direction.

11. a chamber; a table disposed within the chamber and supporting a powder bed containing powder; an irradiation device that irradiates the powder on the table with an energy beam; and a recoater apparatus according to any one of claims 1 to 10, which is disposed in the chamber and levels the surface of the powder bed.

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