JP2021183713A - Three-dimensional forming apparatus and method for manufacturing three-dimensionally formed article - Google Patents

Abstract

To provide a three-dimensional forming apparatus capable of suppressing a larger amount of loss of heat provided for preheating through an electron beam than conventionally.SOLUTION: A three-dimensional forming apparatus 1 includes a stage 11, a base plate 13, a powder bed-forming part 16, an electron gun 21, a metal plate 171, and a support plate 172. The stage is installed in a chamber 10 and can move in a height direction. The base plate is arranged on the stage through a column 14 and is used as a base for forming a formed article 110 laminated three-dimensionally by powder 100. In the powder bed-forming part, a powder bed is formed by covering the base plate with the powder. The electron gun generates an electron beam EB and irradiates the base plate or the powder bed with the electron beam. The metal plate, a position corresponding to the base plate of which is opened, partitions a space on the stage into an upper space of the base plate and a lower space thereof. The support plate supports the metal plate on the stage.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a three-dimensional modeling apparatus for producing a three-dimensional model by repeating a process of selectively melting and solidifying a powder material, and a method for manufacturing a three-dimensional model.

A three-dimensional modeling apparatus that manufactures a three-dimensional model by superimposing a plurality of layers using a metal powder material that can be melted and solidified by irradiating an electron beam is known. In the three-dimensional modeling device, the supply process of supplying the metal powder material to form the powder bed in the area where the three-dimensional model is to be modeled, and the electronic beam for modeling are selectively applied to the metal powder material of the powder bed. It includes a means capable of repeating the molding step of melting and solidifying the metal powder material to perform the molding a plurality of times. Normally, when the metal powder material is irradiated with an electron beam, the powder material is scattered due to the repulsion between the charged metal powder materials due to the Coulomb force. Therefore, before irradiating the metal powder material with the electron beam, a measure for suppressing the charge of the metal powder material is executed in advance. Patent Document 1 discloses a three-dimensional modeling method including a preheating step of preheating a powder material before the modeling process. In the three-dimensional modeling method described in Patent Document 1, in the preheating step, the powder material is irradiated with a defocused electron beam to raise the temperature of the powder material in advance while preventing local charging, and the electrical resistance of the powder material is increased. It is decreasing. As a result, it is possible to prevent electrons from being charged in the powder material by irradiation with an electron beam for modeling for melting and solidifying the powder material.

Japanese Patent Publication No. 2011-506661

However, in a normal 3D modeling device, the base plate, which is the base for modeling a 3D model, is directly attached to a stage that can be moved up and down, or placed on a powder filled on the stage. Has been done. In such a three-dimensional modeling apparatus, when the powder material on the base plate is preheated with an electron beam as in the technique described in Patent Document 1, the base plate is heated, but the stage or the powder material in contact with the base plate is reached. And heat will flow. That is, there is a problem that the loss of heat input for preheating by the electron beam becomes large.

The present disclosure has been made in view of the above, and an object of the present invention is to obtain a three-dimensional modeling apparatus capable of suppressing the loss of heat input for preheating by an electron beam as compared with the conventional case.

In order to solve the above-mentioned problems and achieve the object, the three-dimensional modeling apparatus according to the present disclosure includes a stage, a base plate, a powder bed forming portion, an electron gun, a metal plate, and a support plate. .. The stage is provided in the chamber and can be moved in the height direction. The base plate is arranged on the stage via a support column, and serves as a base for modeling a model that is three-dimensionally laminated by powder. The powder bed forming portion forms a powder bed by spreading the powder on the base plate. The electron gun produces an electron beam and irradiates the base plate or powder bed with the electron beam. The metal plate opens at a position corresponding to the base plate and separates the space above the base plate from the space below the base plate on the stage. The support plate supports the metal plate on the stage.

According to the present disclosure, there is an effect that the loss of heat input for preheating by the electron beam can be suppressed as compared with the conventional case.

Cross-sectional view schematically showing an example of the configuration of the three-dimensional modeling apparatus according to the first embodiment. A cross-sectional view schematically showing an example of the structure around the outer peripheral portion of the base plate of the three-dimensional modeling apparatus according to the second embodiment. Cross-sectional view schematically showing another example of the structure around the outer peripheral portion of the base plate of the three-dimensional modeling apparatus according to the second embodiment. Cross-sectional view schematically showing another example of the structure around the outer peripheral portion of the base plate of the three-dimensional modeling apparatus according to the second embodiment. Cross-sectional view schematically showing an example of the configuration of the three-dimensional modeling apparatus according to the third embodiment. A cross-sectional view schematically showing an example of the structure around the outer peripheral portion of the base plate of the three-dimensional modeling apparatus according to the third embodiment. Cross-sectional view schematically showing an example of the structure around the outer peripheral portion of the base plate of the three-dimensional modeling apparatus according to the fourth embodiment. Cross-sectional view schematically showing an example of the structure around the outer peripheral portion of the base plate of the three-dimensional modeling apparatus according to the fifth embodiment. A cross-sectional view schematically showing an example of the structure around the outer peripheral portion of the base plate of the three-dimensional modeling apparatus according to the sixth embodiment.

Hereinafter, a three-dimensional modeling apparatus and a method for manufacturing a three-dimensional model according to the embodiment of the present disclosure will be described in detail with reference to the drawings.

Embodiment 1.
The three-dimensional modeling device is a device that irradiates a powder material with an electron beam to melt and solidify the powder material to form a three-dimensional model. FIG. 1 is a cross-sectional view schematically showing an example of the configuration of the three-dimensional modeling apparatus according to the first embodiment. The three-dimensional modeling device 1 includes a chamber 10. The chamber 10 has a hermetically sealed structure so that the inside can be evacuated. A vacuum pump (not shown), which is an exhaust device, is connected to the chamber 10, and a predetermined pressure can be obtained by exhausting the inside of the chamber 10.

The three-dimensional modeling device 1 includes an electron gun 21 in an electron gun chamber 20 provided in the upper part of the chamber 10. The electron gun 21 irradiates an electron beam EB at an arbitrary position in the chamber 10. The electron gun 21 has a mechanism for emitting electrons, a mechanism for converging the emitted electrons, and a mechanism for deflecting the electrons so that the electrons are irradiated to a predetermined position.

The three-dimensional modeling apparatus 1 further includes a stage 11, a stage side wall portion 12, a base plate 13, a support column 14, a powder box 15, and a powder floor forming portion 16 inside the chamber 10. The position of the stage 11 can be arbitrarily adjusted in the height direction in order to construct the three-dimensionally stacked shaped objects 110. The outer peripheral portion of the stage 11 is in contact with the side wall portion 12 of the stage. A sealing member may be provided on the outer peripheral portion of the stage 11 that comes into contact with the stage side wall portion 12.

The stage side wall portion 12 has a tubular structure that contacts the outer peripheral portion of the stage 11 and extends in the height direction. The stage side wall portion 12 serves as a guide when the stage 11 moves in the height direction, and also suppresses the powder 100 laid on the stage 11 from moving to the outside in the horizontal direction as compared with the stage 11. Has a role.

The base plate 13 is a base for modeling the model 110, and supports the formed model 110. The base plate 13 is made of a material having high heat resistance that does not melt with respect to the irradiation of the electron beam EB from the electron gun 21 in the modeling process in which the three-dimensional modeling apparatus 1 is in operation. In one example, the base plate 13 is made of stainless steel, carbon steel, copper, titanium and aluminum.

The stanchion 14 supports the base plate 13 on the stage 11. The support column 14 supports the base plate 13 so that the base plate 13 is installed in parallel with the modeling surface, which is the surface on which the model 110 is modeled. When the base plate 13 has a rectangular shape, the columns 14 are provided at positions near the four corners of the base plate 13. The height of the support column 14 may be fixed, or the height may be independently adjustable. The number of columns 14 is not limited to this, and may be any number as long as the base plate 13 can be supported on the stage 11. The lower end of the column 14 is in contact with the stage 11, and the upper end is in contact with the base plate 13. The support column 14 has a main body portion 141 and a contact portion 142 in contact with the base plate 13. In the example of FIG. 1, the contact portion 142 is the upper end portion of the support column 14. The area where the contact portion 142 contacts the base plate 13 is smaller than the cross-sectional area perpendicular to the extending direction of the main body portion 141, that is, the height direction. In the example of FIG. 1, the contact portion 142 has a tapered shape from the connection portion with the main body portion 141 toward the base plate 13, but if the shape of the contact portion 142 is smaller than the cross-sectional area of the main body portion 141, It may have any shape. As a result, the contact area between the support column 14 and the base plate 13 is reduced, and heat transfer from the base plate 13 to the support column 14 is suppressed.

The strut 14 is, in one example, made of a material having a thermal conductivity lower than that of iron (Fe). In one example, the stanchion 14 is made of zirconium (Zr). Further, only the contact portion 142 may be made of a material such as zirconium having a thermal conductivity lower than that of iron.

The powder box 15 stores the powder 100 that is the raw material of the model 110. An example of the powder 100 is a metal powder. As the metal powder, titanium (Ti), various steels, copper (Cu), and other metal powders according to the application are used. An example of the average particle size of the metal powder is 20 μm or more and 200 μm or less, and a metal powder having an average particle size according to the application is used.

The powder bed forming portion 16 moves on the base plate 13 to spread the powder 100 supplied from the powder box 15 on the base plate 13 to form a powder bed. An example of the powder bed forming portion 16 is a squeegee.

The three-dimensional modeling apparatus 1 reflects radiant heat generated from the modeling region on the surface of the modeling region with respect to the modeling region for modeling the three-dimensional model 110, and receives a part of the reflected radiant heat to generate a temperature. A mechanism for raising the temperature may be provided above the modeling area. By providing such a mechanism, the temperature of the modeling region can be efficiently increased and maintained.

The three-dimensional modeling device 1 further includes a powder drop suppressing portion 17 arranged around the base plate 13 supported by the support column 14. The powder drop suppressing portion 17 has a metal plate 171 whose outer peripheral portion is in contact with the stage side wall portion 12 and whose inner peripheral portion is in contact with the outer peripheral portion of the base plate 13, and a support plate 172 which supports the metal plate 171 on the stage 11. Have.

The metal plate 171 has the same size as the stage 11 when viewed from above the stage 11, and has a shape in which the position corresponding to the base plate 13 is open. The metal plate 171 separates the space in which the three-dimensional model 110 in the upper part of the base plate 13 is formed and the space in the lower part of the base plate 13. As a result, the powder 100 constituting the powder bed to be spread for modeling the three-dimensional model 110 is suppressed from flowing into the space below the base plate 13.

In the example of FIG. 1, the height of the support plate 172 is set to a height at which the position of the upper surface of the metal plate 171 is within the thickness range of the base plate 13. The support plate 172 also serves as a radiant shield for suppressing heat loss due to radiant heat from the base plate 13. The number of support plates 172 installed may be one or a plurality.

The metal plate 171 and the support plate 172 are preferably made of a material capable of suppressing heat loss due to heat conduction transmitted through the metal plate 171 and the support plate 172. In one example, the metal plate 171 and the support plate 172 are preferably made of a material having a lower thermal conductivity than iron, such as stainless steel. Although FIG. 1 shows a case where the inner peripheral portion of the metal plate 171 contacts the outer peripheral portion of the base plate 13, when the metal plate 171 is located below the base plate 13 and viewed from above the stage 11. , A part of the metal plate 171 may be arranged so as to overlap with the base plate 13.

Next, a method for manufacturing a three-dimensional model by operating the three-dimensional model device 1 to manufacture the three-dimensional model will be described. First, the powder box 15 is filled with a predetermined amount of powder 100. Further, the base plate 13 is placed so as to be supported by the support column 14 in the area where the support column 14 is exposed, which is not covered by the metal plate 171 on the stage 11. After that, the inside of the chamber 10 is exhausted by the vacuum pump so that the inside of the chamber 10 has a predetermined degree of vacuum. After the inside of the chamber 10 reaches a predetermined degree of vacuum, the base plate 13 is irradiated with the electron beam EB from the electron gun 21, and the base plate 13 is preheated. This preheating is performed before the molding of the first layer. Further, in the preheating of the base plate 13, the irradiation condition, that is, the electron beam EB whose output is adjusted so that the base plate 13 does not melt is irradiated.

After the base plate 13 is preheated to a predetermined temperature by irradiation with the electron beam EB whose output is adjusted, the stage 11 is lowered by the height of one layer of the powder bed. After that, the powder 100 supplied from the powder box 15 is spread evenly by the powder bed forming portion 16, so that a powder bed for one layer is laid on the region including the base plate 13 and the metal plate 171. To form the powder bed, the powder bed forming portion 16 may be passed once or a plurality of times on the region including the base plate 13 and the metal plate 171. At this time, since the metal plate 171 is provided so as to be in contact with the outer peripheral portion of the base plate 13, when the powder 100 is spread even by the movement of the powder bed forming portion 16, the powder 100 is placed in the space below the base plate 13. Is suppressed from falling.

After laying the powder bed, leave it as it is until a predetermined time elapses. During this period, the laid powder bed is preheated by heat conduction from the base plate 13. That is, the formed powder bed is preheated by heat conduction from the preheated base plate 13. As a result, the electric resistance of the powder 100 decreases, and even if the electron beam EB is irradiated in a later step, the powder 100 is in a state of not repelling due to the Coulomb force.

Then, according to a preset irradiation pattern of the electron beam EB, the electron beam EB whose conditions are adjusted so as not to melt the powder 100 is irradiated to the entire powder bed, and the powder bed is heated. After the entire powder bed is heated by the irradiation of the electron beam EB, the electron beam EB whose conditions are set for modeling follow a modeling pattern which is a pattern for forming a predetermined model 110. Be irradiated. By this irradiation, the powder 100 of the necessary portion is melted and solidified. As a result, the first-layer model 110 is formed.

After irradiation of the electron beam EB along the modeling pattern, the electron beam EB whose conditions are adjusted so that the powder 100 does not melt in order to reheat the powder bed whose temperature has dropped is according to a preset irradiation pattern. The powder bed is irradiated.

After that, the stage 11 is lowered by the height of one layer of the powder bed to form the powder bed, the preheat treatment of the powder bed by the electron beam EB, the irradiation treatment of the electron beam EB according to the modeling pattern, and the electron beam. The re-preheat treatment of the powder bed by EB is repeatedly carried out. As a result, the process of forming the powder bed of the next layer on the front layer is repeated, and as a result, the model 110 laminated in three dimensions is completed.

Here, the effect of the three-dimensional modeling apparatus 1 according to the first embodiment compared with the comparative example will be described. The three-dimensional modeling apparatus according to the comparative example has a structure in which the base plate is directly attached to a stage that can be raised and lowered in the height direction, or a structure in which the base plate is placed on a powder filled on the stage. That is, the three-dimensional modeling apparatus 1 according to the first embodiment has a structure in which the support column 14 and the powder drop suppressing portion 17 are not provided on the stage 11. Therefore, heat flows from the base plate preheated to several hundred degrees to the stage in contact with the base plate by heat conduction, or heat flows to the powder in contact with the base plate. In this way, the loss of heat input due to the irradiation of the electron beam EB has increased.

Further, the three-dimensional modeling apparatus according to another comparative example has a structure in which the base plate is supported by columns on the stage. That is, the three-dimensional modeling apparatus 1 according to the first embodiment has a structure in which the powder drop suppressing portion 17 is not provided. In such a three-dimensional modeling apparatus, it is possible to suppress the flow of heat from the base plate to the stage by forming the columns with a material having a low thermal conductivity such as Zr. However, not a little powder is required to fill the space between the lower part of the base plate and the stage, and the heat loss due to the heat flow from the base plate to the powder cannot be suppressed. Further, in the process of modeling a three-dimensional model, powder flows into the space between the lower part of the base plate and the stage sequentially from the powder bed spread for modeling the three-dimensional model. For this reason, it was difficult to uniformly supply and spread the powder over the entire region irradiated with the electron beam EB.

However, in the three-dimensional modeling apparatus 1 according to the first embodiment, a metal plate 171 that separates the space above the base plate 13 and the space below the base plate 13 and a support plate 172 that supports the metal plate 171 on the stage 11 are provided. Be done. This eliminates the need for the powder 100 to fill the space below the base plate 13, and prevents the powder 100 from flowing into the space between the stage 11 and the bottom of the base plate 13. That is, the lower surface of the base plate 13 does not come into contact with the powder 100, and a space is maintained between the base plate 13 and the stage 11. As a result, heat does not flow from the base plate 13 to the powder 100, so that heat loss due to heat conduction from the base plate 13 heated to a high temperature by preheating to the powder 100 can be suppressed. Further, during the modeling process, the inside of the chamber 10 is evacuated, and the space between the base plate 13 and the metal plate 171 and the stage 11 is also evacuated, so that the generation of radiant heat loss from the preheated base plate 13 can be suppressed. Further, in the process of modeling the three-dimensional model 110, the powder 100 is suppressed from flowing into the space below the base plate 13, so that the powder 100 is evenly spread over the entire region irradiated with the electron beam EB. Is possible.

Embodiment 2.
FIG. 2 is a cross-sectional view schematically showing an example of the structure around the outer peripheral portion of the base plate of the three-dimensional modeling apparatus according to the second embodiment. Since the configuration of the three-dimensional modeling apparatus 1 according to the second embodiment is the same as that of the first embodiment, the parts different from the first embodiment will be described below.

In the three-dimensional modeling apparatus 1 according to the second embodiment, the base plate 13 and the metal plate 171 are arranged at a distance d in a state where the base plate 13 is not heated, for example, in a room temperature state. Further, in this example, the metal plate 171 is arranged so as to be located below the lower surface of the base plate 13. Assuming that the amount by which the length of the base plate 13 increases due to the temperature rise during the operation of the three-dimensional modeling apparatus 1 is ΔL, the positions of the base plate 13 and the metal plate 171 are designed so that d <ΔL.

In the three-dimensional modeling apparatus 1 according to the second embodiment, the base plate 13 is preheated before the modeling of the first layer as in the first embodiment. Due to the temperature rise of the base plate 13 due to preheating, the base plate 13 thermally expands and its dimensions increase. As shown in FIG. 2, the position of the outer peripheral portion of the base plate 13 moves outward by ΔL. In the second embodiment, the relationship between the dimensional change amount ΔL in the outer peripheral portion of the base plate 13 and the distance d between the base plate 13 and the metal plate 171 before the temperature rise is defined. That is, by setting d <ΔL, after the temperature of the base plate 13 is raised by preheating, the outer peripheral portion of the base plate 13 overlaps with the metal plate 171 when viewed from above the base plate 13. As a result, the gap between the base plate 13 and the metal plate 171 in the horizontal direction is eliminated, and the inflow of the powder 100 into the space below the base plate 13 can be further suppressed.

In one example, the base plate 13 is made of general stainless steel SUS (Steel special Use Stainless) 304, has a length of 150 mm, and has a ΔL of 0.98 mm when the temperature is raised to 700 ° C. during the molding process. .. Here, ΔL is the amount of increase in the dimension of one side of the base plate 13 when the linear expansion coefficient of the stainless steel SUS304 is 18.7 × 10 ^{-6 / K and the base plate 13 is assumed to be symmetrical.} Therefore, the base plate 13 and the metal plate 171 are installed so that the distance d between the base plate 13 and the metal plate 171 before the temperature rise is d <0.98 mm.

FIG. 2 shows a case where the metal plate 171 is arranged below the base plate 13, but the arrangement relationship between the metal plate 171 and the base plate 13 is not limited to this. 3 and 4 are cross-sectional views schematically showing another example of the structure around the outer peripheral portion of the base plate of the three-dimensional modeling apparatus according to the second embodiment. FIG. 3 shows a case where the metal plate 171 is arranged within the thickness range of the base plate 13, and FIG. 4 shows a case where the upper surface of the metal plate 171 and the upper surface of the base plate 13 coincide with each other. Even in these cases, the distance d between the outer peripheral portion of the base plate 13 and the inner peripheral portion of the metal plate 171 is d <ΔL. However, the recesses 131a and 131b are provided at the positions of the base plate 13 in the height direction in which the metal plate 171 is provided. The distance D between the bottom surfaces 132a and 132b of the recesses 131a and 131b and the inner peripheral portion of the metal plate 171 is D ≧ ΔL.

In FIG. 3, a recess 131a formed by grooving is provided near the center of the outer peripheral portion of the base plate 13 in the thickness direction. It is desirable that the depth, which is the horizontal length of the recess 131a, is ΔL−d or more. In FIG. 4, a recess 131b formed by grooving is provided on the upper portion of the outer peripheral portion of the base plate 13. In FIG. 4, the structure is such that a step structure is provided on the upper surface of the base plate 13. Even in this case, it is desirable that the depth of the recess 131b, which is the horizontal length, is ΔL−d or more. In the structure as shown in FIGS. 3 and 4, when the base plate 13 is preheated and the temperature is raised, the position of the outer peripheral portion of the base plate 13 moves outward by ΔL, and the metal plate 171 moves to the outside of the recesses 131a and 131b of the base plate 13. Fit into.

In the three-dimensional modeling apparatus 1 according to the second embodiment, the relationship d <ΔL when the distance d between the base plate 13 and the metal plate 171 is ΔL and the amount at which the position of the outer peripheral portion of the base plate 13 changes due to the temperature rise is ΔL. It was designed to be. This makes it possible to further suppress the inflow of the powder 100 into the space below the base plate 13.

Embodiment 3.
FIG. 5 is a cross-sectional view schematically showing an example of the configuration of the three-dimensional modeling apparatus according to the third embodiment. Hereinafter, the same components as those of the three-dimensional modeling apparatus 1 of the first embodiment are designated by the same reference numerals, the description thereof will be omitted, and the parts different from the first embodiment will be described. The three-dimensional modeling apparatus 1 according to the third embodiment further includes a radiation shield 18 under the base plate 13 in the space between the base plate 13 and the stage 11. The radiant shield 18 suppresses heat loss due to radiant heat from the bottom surface of the base plate 13. The radiation shield 18 is fixed to the support column 14.

FIG. 6 is a cross-sectional view schematically showing an example of the structure around the outer peripheral portion of the base plate of the three-dimensional modeling apparatus according to the third embodiment. The radiation shield 18 has a structure such that at least a part thereof overlaps with the metal plate 171 when viewed from above the base plate 13. By having the overlap with the metal plate 171 the powder 100 flowing in from the gap between the base plate 13 and the metal plate 171 is deposited on the radiation shield 18 and is suppressed from being deposited on the stage 11.

Since the radiant shield 18 has a role of suppressing heat loss due to radiant heat from the base plate 13, it is preferable that the radiation shield 18 has a dimension that covers the entire bottom surface of the base plate 13, but the dimension is smaller than the bottom surface of the base plate 13. However, the above effect can be obtained.

In the above description, the case where the radiation shield 18 is provided in the configuration of the first embodiment has been described, but the radiation shield 18 may be provided in the configuration of the second embodiment.

The three-dimensional modeling apparatus 1 according to the third embodiment includes a radiation shield 18 under the base plate 13. Therefore, heat loss due to radiant heat from the bottom surface of the base plate 13 can be suppressed. Further, the radiation shield 18 is provided so as to overlap at least a part of the metal plate 171 when viewed from above the base plate 13. As a result, it is possible to prevent the powder 100 flowing in from the gap between the base plate 13 and the metal plate 171 from accumulating in the space below the base plate 13.

Embodiment 4.
FIG. 7 is a cross-sectional view schematically showing an example of the structure around the outer peripheral portion of the base plate of the three-dimensional modeling apparatus according to the fourth embodiment. Since the configuration of the three-dimensional modeling apparatus 1 according to the fourth embodiment is the same as that of the first and third embodiments, the parts different from the first and third embodiments will be described below.

In the three-dimensional modeling apparatus 1 according to the fourth embodiment, in the configuration of the third embodiment, the end portion on the inner peripheral portion side of the metal plate 171 and the end portion on the outer peripheral portion side of the radiation shield 18a have a return shape. , Has a three-dimensionally overlapping structure. The metal plate 171 has a return portion 171b in which the outer peripheral portion of the top plate portion 171a parallel to the base plate 13 is bent downward. Further, the radiation shield 18a has a return portion 182 in which the outer peripheral portion of the bottom surface portion 181 parallel to the base plate 13 is bent upward. The return portion 182 of the radiation shield 18a is arranged outside the return portion 171b of the metal plate 171. That is, the metal plate 171 and the radiation shield 18a have a return structure in which the metal plate 171 and the radiation shield 18a overlap each other both when viewed from above the base plate 13 and when viewed from the side surface. With this structure, it is possible to further prevent the powder 100 deposited on the radiation shield 18a from flowing down onto the stage 11. The radiation shield 18a having a return structure may be integrally configured by bending the outer peripheral portion of one plate-shaped member, or two or more members including the bottom surface portion 181 and the return portion 182. May be configured by joining.

In the three-dimensional modeling apparatus 1 according to the fourth embodiment, the return portion 171b projecting downward is provided at the end portion of the metal plate 171 on the inner peripheral portion side, and the return portion 171b projecting upward is provided at the end portion of the radiation shield 18a on the outer peripheral portion side. A portion 182 is provided so that the return portion 171b of the metal plate 171 and the return portion 182 of the radiation shield 18a are three-dimensionally overlapped with each other. As a result, it is possible to prevent the powder 100 flowing out on the radiation shield 18a from accumulating on the space below the base plate 13, that is, on the stage 11.

Embodiment 5.
FIG. 8 is a cross-sectional view schematically showing an example of the structure around the outer peripheral portion of the base plate of the three-dimensional modeling apparatus according to the fifth embodiment. Since the configuration of the three-dimensional modeling apparatus 1 according to the fifth embodiment is the same as that of the first, third, and fourth embodiments, the parts different from the first, third, and fourth embodiments will be described below.

The three-dimensional modeling apparatus 1 according to the fifth embodiment has a configuration in which the radiation shield 18a is provided with two layers or a plurality of layers in the configuration of the fourth embodiment. FIG. 8 shows an example in which two radiation shields 18a and 18b are provided in the height direction. With this structure, the heat loss due to the radiant heat from the bottom surface of the base plate 13 can be further suppressed as compared with the cases of the third and fourth embodiments, and the effects shown in the third and fourth embodiments can be further improved. can.

The radiation shields 18a and 18b may all have the same size or may have different sizes. Further, when the sizes are different, they may be arranged so as to increase downward from the base plate 13 side. Further, it is preferable that the distance between the two radiation shields 18a and 18b adjacent to each other in the height direction is as small as possible within a range where they do not touch each other.

Although FIG. 8 shows a case where the radiation shield 18b is further provided in the configuration of the fourth embodiment, the radiation shield 18 may be further provided in the configuration of the third embodiment. That is, a plurality of flat plate-shaped radiation shields 18 may be provided. Further, the flat plate-shaped radiation shield 18 and the radiation shield 18b having a return structure may be provided in a mixed manner.

The three-dimensional modeling apparatus 1 according to the fifth embodiment includes a plurality of radiation shields 18a and 18b. Thereby, the effect of suppressing the heat loss due to the radiant heat from the bottom surface of the base plate 13 can be further improved as compared with the third and fourth embodiments.

Embodiment 6.
FIG. 9 is a cross-sectional view schematically showing an example of the structure around the outer peripheral portion of the base plate of the three-dimensional modeling apparatus according to the sixth embodiment. Since the configuration of the three-dimensional modeling apparatus 1 according to the sixth embodiment is the same as that of the first, third, fourth, and fifth embodiments, the parts different from the first, third, fourth, and fifth embodiments will be described below. do.

In the three-dimensional modeling apparatus 1 according to the sixth embodiment, in the configuration of the fifth embodiment, the groove portion 133 is provided on the bottom surface portion of the base plate 13. Further, in the three-dimensional modeling apparatus 1 according to the sixth embodiment, the return portion 182 of the radiation shield 18a is fitted to the groove portion 133 provided on the bottom surface of the base plate 13. That is, the groove portion 133 on the bottom surface of the base plate 13 has a structure that can be fitted with the return portion 182 of the radiation shield 18a.

By fitting the return portion 182 of the radiation shield 18a into the groove portion 133 provided on the bottom surface of the base plate 13, it flows into the space created between the base plate 13 and the radiation shield 18a through the gap between the metal plate 171 and the base plate 13. It is possible to prevent the powder 100 from entering.

FIG. 9 shows a structure in which the return portion 182 of the uppermost radiation shield 18a closest to the base plate 13 is fitted to the groove portion 133 of the base plate 13 among the plurality of radiation shields 18a and 18b. However, the return portion 182 of the lower radiation shield 18b is fitted into the groove portion 133 of the base plate 13, and the upper radiation shield 18a has a structure such that it is located between the base plate 13 and the lower radiation shield 18b. May be. Further, when three or more layers of radiation shields are provided, the radiation shield fitted in the groove portion 133 of the base plate 13 may be any radiation shield.

Note that FIG. 9 shows a case where any one of the plurality of radiation shields 18a and 18b fits with the groove portion 133 on the bottom surface of the base plate 13 in the configuration of the fifth embodiment. However, all of the radiation shields 18a and 18b having the return portion 182 may be fitted to the groove portion 133 on the bottom surface of the base plate 13.

The three-dimensional modeling apparatus 1 according to the sixth embodiment has a structure in which the return portion 182 of the radiation shield 18a is fitted to the groove portion 133 provided on the bottom surface of the base plate 13. As a result, it is possible to prevent the powder 100 that has flowed in from the gap between the metal plate 171 and the base plate 13 from entering the space formed between the base plate 13 and the radiation shield 18a. In addition, heat loss due to heat conduction from the base plate 13 to the powder 100 can be suppressed.

The configuration shown in the above embodiments is an example, and can be combined with another known technique, can be combined with each other, and does not deviate from the gist. It is also possible to omit or change a part of the configuration.

1 Three-dimensional modeling device, 10 chambers, 11 stages, 12 stage side walls, 13 base plates, 14 columns, 15 powder boxes, 16 powder floor forming parts, 17 powder drop suppression parts, 18, 18a, 18b radiation shields, 20 electron guns Chamber, 21 electron gun, 100 powder, 110 model, 131a, 131b recess, 132a, 132b bottom, 133 groove, 141 main body, 142 contact, 171 metal plate, 171a top plate, 171b, 182 return part, 172 Support plate, 181 bottom surface, EB electron beam.

Claims (9)

A stage that is installed in the chamber and can be moved in the height direction,
A base plate that is placed on the stage via a support and serves as a base for modeling a model that is three-dimensionally laminated by powder.
A powder bed forming portion for forming a powder bed by spreading the powder on the base plate, and a powder bed forming portion.
An electron gun that generates an electron beam and irradiates the base plate or the powder bed with the electron beam.
A metal plate that opens at a position corresponding to the base plate and separates the space above the base plate from the space below the base plate on the stage.
A support plate that supports the metal plate on the stage,
A three-dimensional modeling device characterized by being equipped with. When the distance between the outer peripheral portion of the base plate and the inner peripheral portion of the metal plate is d, and the amount of change in the position of the outer peripheral portion of the base plate due to temperature rise is ΔL, the relationship of d <ΔL is obtained. The three-dimensional modeling apparatus according to claim 1, wherein the base plate and the metal plate are arranged as described above. The three-dimensional modeling apparatus according to claim 2, wherein the metal plate is arranged below the position of the bottom surface of the base plate. The metal plate is arranged so as to overlap the base plate in the height direction.
The three-dimensional modeling apparatus according to claim 3, wherein the base plate has a recess in which the metal plate can be fitted at a position of an outer peripheral portion that overlaps with the metal plate in the height direction. The three-dimensional modeling apparatus according to any one of claims 1 to 4, further comprising a radiation shield below the base plate, which at least partially overlaps with the metal plate when viewed from above. .. The three-dimensional modeling apparatus according to claim 5, wherein a plurality of the radiation shields are provided below the base plate in the height direction. The radiation shield has a barb that projects upward at the end of the outer peripheral portion.
The metal plate has a barb that protrudes downward at the end of the inner peripheral portion.
The three-dimensional modeling apparatus according to claim 5 or 6, wherein the radiation shield and the metal plate are arranged so as to be three-dimensionally overlapped with each other. The base plate has a groove portion on the bottom surface that can be fitted with the return portion of the radiation shield.
The three-dimensional modeling apparatus according to claim 7, wherein the return portion of the radiation shield is fitted with the groove portion of the base plate. A position corresponding to the base plate that serves as a base for modeling a model that is three-dimensionally laminated by powder is opened, and a metal plate that separates the space above the base plate from the space below the base plate is interposed through the support plate. A step of arranging the base plate on a support column arranged inside the opening on an arranged, height-movable stage.
The step of irradiating the base plate with an electron beam to preheat the base plate, and
The process of laying a powder bed on which the powder is spread on the preheated base plate, and
The step of irradiating the powder bed with the electron beam according to the irradiation pattern, and
A method for manufacturing a three-dimensional model, which comprises.

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