Three-dimensional modeling device

Abstract

To suppress deformation of a first material molding layer due to heat by a laser when a second material molding layer is stacked on the first material molding layer, and the second material molding layer is irradiated with the laser.SOLUTION: A three-dimensional molding apparatus 1 includes a stage 22, first material supply means 30A for supplying a first material Oa, second material supply means 30B for supplying a second material Ob having a sintering temperature higher than a melting point of the first material Oa, laser irradiation means 28, and a control part 23 for selecting a first laser irradiation mode and a second laser irradiation mode with less heat diffusion to a lower layer than the first laser irradiation mode, and controlling the laser irradiation means 28, in which the control part 23 selects the second laser irradiation mode and controls the laser irradiation means when irradiating a second material molding layer 502 formed by supplying a second material Ob onto a first material molding layer 501 formed by supplying the first material Oa onto the stage 22 with a laser L from the laser irradiation means 28.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a three-dimensional modeling apparatus. [Background technology]

[0002] Conventionally, three-dimensional modeling devices that manufacture three-dimensional objects by stacking modeling layers have been used. Among these, there are three-dimensional modeling devices that stack modeling layers using multiple materials. For example, Patent Document 1 discloses a laser powder additive manufacturing device that supplies resin powder onto a resin or metal substrate and irradiates the resin powder with a laser to manufacture a three-dimensional object made of multiple materials. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] WO2016 / 121013 publication Summary of the Invention [Problem to be solved by the invention]

[0004] The laser powder additive manufacturing device of Patent Document 1 supplies resin powder onto a resin or metal substrate and irradiates the resin powder with a laser, so that the laser is irradiated onto an upper layer whose sintering temperature is equal to or lower than the melting point of the lower layer. However, when the laser is irradiated onto an upper layer whose sintering temperature is higher than the melting point of the lower layer, the heat from the laser is transferred to the lower layer, causing the lower layer to melt and deform due to the heat from the laser, which may reduce the manufacturing accuracy of the three-dimensional object. [Means for solving the problem]

[0005] The three-dimensional modeling apparatus of the present invention for solving the above-mentioned problems is a three-dimensional modeling apparatus that manufactures a three-dimensional object by stacking a modeling layer on a lower layer, and comprises a stage, a first material supplying means for supplying a first material, a second material supplying means for supplying a second material having a sintering temperature higher than the melting point of the first material, a laser irradiation means, and a control unit that selects between a first laser irradiation mode and a second laser irradiation mode in which heat diffusion to lower layers is less than in the first laser irradiation mode, and controls the laser irradiation means, wherein the control unit selects the second laser irradiation mode and controls the laser irradiation means when irradiating a laser from the laser irradiation means to a second material modeling layer as the modeling layer formed by supplying the second material onto a first material modeling layer as the modeling layer formed by supplying the first material onto the stage. [Brief description of the drawings]

[0006] [Figure 1] 1 is a schematic front view illustrating a configuration of a three-dimensional modeling apparatus according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic front view illustrating a configuration of a material supplying unit of the three-dimensional modeling apparatus of FIG. 1. [Diagram 3] FIG. 2 is a schematic perspective view showing a screw of the three-dimensional modeling apparatus of FIG. 1 . [Figure 4] 2 is a schematic plan view showing a state in which a modeling material is filled into the screw of the three-dimensional modeling apparatus of FIG. 1. [Diagram 5] FIG. 2 is a schematic plan view showing a barrel of the three-dimensional modeling apparatus of FIG. 1 . [Figure 6] 2 is a schematic front view illustrating a state in which a three-dimensional object is being manufactured using the three-dimensional printing apparatus of FIG. 1. [Figure 7] 2 is a flowchart of an example of a three-dimensional printing method using the three-dimensional printing apparatus of FIG. 1 . [Figure 8] 2 is a graph showing the energy intensity distribution of the laser used when irradiating a laser using the 3D modeling apparatus of FIG. 1. [Figure 9] 2 is a graph showing the heat distribution in the depth direction of the material of the laser used when irradiating the material with the laser using the 3D modeling apparatus of FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] First, the present invention will be briefly described. A first aspect of the present invention for solving the above-mentioned problem is a three-dimensional modeling apparatus that manufactures a three-dimensional object by stacking a modeling layer on a lower layer, and includes a stage, a first material supplying means for supplying a first material, a second material supplying means for supplying a second material having a sintering temperature higher than the melting point of the first material, a laser irradiation means, and a control unit that selects between a first laser irradiation mode and a second laser irradiation mode in which heat diffusion to lower layers is less than in the first laser irradiation mode, and controls the laser irradiation means, wherein the control unit selects the second laser irradiation mode and controls the laser irradiation means when irradiating a laser from the laser irradiation means to a second material modeling layer as the modeling layer that is formed by supplying the second material onto a first material modeling layer as the modeling layer that is formed by supplying the first material onto the stage.

[0008] According to this aspect, in addition to the first laser irradiation mode, there is a second laser irradiation mode in which heat diffusion to the lower layer is less than that in the first laser irradiation mode. Then, when the laser irradiation means irradiates a laser to a second material modeling layer, which is an upper layer formed by supplying a second material whose sintering temperature is higher than the melting point of the first material, on a first material modeling layer, which is a lower layer formed by supplying a first material onto a stage, the second laser irradiation mode is selected. Therefore, when irradiating a laser to an upper layer whose sintering temperature is higher than the melting point of the lower layer, it is possible to prevent heat from the laser from being transmitted to the lower layer. Therefore, when the second material modeling layer is stacked on the first material modeling layer and the second material modeling layer is irradiated with a laser, it is possible to suppress deformation of the first material modeling layer due to heat from the laser.

[0009] A three-dimensional modeling apparatus according to a second aspect of the present invention is the three-dimensional modeling apparatus according to the first aspect, characterized in that the second laser irradiation mode uses a laser having a shorter pulse width than the first laser irradiation mode.

[0010] According to this aspect, in the second laser irradiation mode, a laser having a shorter pulse width is used than in the first laser irradiation mode. By using a laser having a shorter pulse width, it is possible to reduce the diffusion of heat, and therefore, when the second material modeling layer is laminated on the first material modeling layer and the second material modeling layer is irradiated with a laser, it is possible to suppress deformation of the first material modeling layer due to heat from the laser.

[0011] The three-dimensional modeling apparatus of a third aspect of the present invention is the three-dimensional modeling apparatus of the first aspect, characterized in that at least the second laser irradiation mode uses a laser having a top-hat shaped energy intensity distribution.

[0012] According to this aspect, a laser having a top-hat shaped energy intensity distribution is used in the second laser irradiation mode. By using a laser having a top-hat shaped energy intensity distribution, it is possible to more evenly apply thermal energy to a meltable region of a certain width than when using a laser having a Gaussian energy intensity distribution, and it is possible to suppress the supply of excessive thermal energy as in the case of a Gaussian distribution, and to suppress the diffusion of heat over a wide range. Therefore, when a second material modeling layer is laminated on a first material modeling layer and the second material modeling layer is irradiated with a laser, it is possible to suppress deformation of the first material modeling layer due to heat from the laser.

[0013] A three-dimensional printing apparatus according to a fourth aspect of the present invention is any one of the first to third aspects, characterized in that the first material is a resin.

[0014] According to this aspect, the first material is a resin, and therefore when an upper layer is laminated on a lower resin layer and the upper layer is irradiated with a laser, it is possible to prevent the lower resin layer from being deformed by heat from the laser.

[0015] A three-dimensional printing apparatus according to a fifth aspect of the present invention is any one of the first to fourth aspects, characterized in that the second material is a metal or a ceramic.

[0016] According to this embodiment, the second material is a metal or a ceramic. Therefore, when a metal layer or a ceramic layer is laminated on a lower layer and the metal layer or the ceramic layer is irradiated with a laser, the lower layer can be prevented from being deformed by heat from the laser. In particular, when the lower layer is a resin layer, when a metal layer or a ceramic layer is laminated on the resin layer as the lower layer and the metal layer or the ceramic layer is irradiated with a laser, the lower resin layer can be prevented from being deformed by heat from the laser particularly effectively.

[0017] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. Note that all of the following drawings are schematic diagrams, and some components are omitted or simplified. In addition, the X-axis direction in each drawing is the horizontal direction, the Y-axis direction is the horizontal direction and also perpendicular to the X-axis direction, and the Z-axis direction is the vertical direction.

[0018] First, the overall configuration of a three-dimensional modeling apparatus 1 according to an embodiment of the present invention will be described with reference to FIGS.

[0019] The three-dimensional printing apparatus 1 of this embodiment is a three-dimensional printing apparatus that laminates a printing layer 500 using a first material Oa and a second material Ob, and manufactures a three-dimensional object O by sintering at least the second material Ob with a laser L. The first material Oa may be configured not to be sintered, or may be configured to be sintered. As shown in FIG. 1, the three-dimensional printing apparatus 1 of this embodiment includes two material supplying means 30 that supply materials for forming the printing layer 500, a stage unit 22 as a stage for printing the three-dimensional object O, and a laser irradiation means 28 that can irradiate the printing layer with a laser L. Furthermore, the three-dimensional printing apparatus 1 includes a control unit 23 that controls the driving of each component of the three-dimensional printing apparatus 1, such as the material supplying means 30, the stage unit 22, and the laser irradiation means 28.

[0020] The three-dimensional modeling apparatus 1 of this embodiment includes, as the material supplying means 30, a first material supplying means 30A for supplying a first material Oa and a second material supplying means 30B for supplying a second material Ob. The second material Ob is a material having a sintering temperature higher than the melting point of the first material Oa. In the three-dimensional modeling apparatus 1 of this embodiment, pellets 19 can be used as a modeling material for modeling the three-dimensional model O. That is, the first material supplying means 30A uses a pellet 19A having the first material Oa, and the second material supplying means 30B uses a pellet 19B having the second material Ob. The pellet 19A may contain other materials such as a binder in addition to the first material Oa, and the pellet 19B may contain other materials such as a binder in addition to the second material Ob. Here, in the three-dimensional modeling apparatus 1 of this embodiment, the first material supplying means 30A and the second material supplying means 30B have exactly the same configuration.

[0021] 2 shows the material supplying means 30, but since the first material supplying means 30A and the second material supplying means 30B have exactly the same configuration, it corresponds to both the first material supplying means 30A and the second material supplying means 30B. As shown in Fig. 2, the material supplying means 30 includes a hopper 2 that stores pellets 19 as a molding material for forming a three-dimensional object O. The pellets 19 stored in the hopper 2 are supplied through a supply pipe 3 to a circumferential surface 4a of a screw 4, which is a substantially cylindrical flat screw.

[0022] The three-dimensional printing apparatus 1 of this embodiment is configured to use pellets 19 as a printing material for forming the three-dimensional object O, and to discharge the printing material while plasticizing it with a flat screw, but the present invention is not limited to the three-dimensional printing apparatus 1 configured as such. For example, the three-dimensional printing apparatus 1 may be configured to form the three-dimensional object O by continuously discharging from a discharge unit a filament that is a linear printing material made of resin, or a metal filament in which a metal powder is mixed with a resin material, while melting the filament. Furthermore, the three-dimensional object O may be formed by discharging from a discharge unit a fluid in which a first material Oa or a second material Ob is dissolved in a solvent or dispersed in a dispersion medium.

[0023] As shown in Fig. 3, a spiral groove 4b is formed on the groove forming surface 18, which is the bottom surface of the screw 4, from the circumferential surface 4a to the central part Cp. In other words, the ribs 4d formed as the grooves 4b are formed form the groove forming surface 18. In the three-dimensional modeling apparatus 1 of this embodiment, the drive motor 6 shown in Fig. 2 rotates the screw 4 about the Z-axis direction as the rotation axis, thereby supplying the pellets 19 from the circumferential surface 4a to the central part Cp while plasticizing them, as shown in Fig. 4. Although not shown in Fig. 1, cooling water circulates near the drive motor 6 to suppress a rise in temperature of the drive motor 6.

[0024] As shown in FIG. 2, the barrel 5 is provided at a position facing the grooved surface 18 of the screw 4 with a predetermined distance therebetween. A heating unit 7 is provided in the vicinity of the opposing surface 8 of the barrel 5, which is the upper surface of the barrel 5, facing the grooved surface 18. Since the screw 4 and the barrel 5 are configured as described above, the pellets 19 are supplied to the space portion 20 that corresponds to the position of the groove 4b and is formed between the grooved surface 18 of the screw 4 and the opposing surface 8 of the barrel 5 by rotating the screw 4, and the pellets 19 move from the circumferential surface 4a to the center portion Cp. When the pellets 19 move through the space portion 20 formed by the groove 4b, the pellets 19 are melted by the heat of the heating unit 7 and are pressurized by the pressure caused by moving through the narrow space portion 20. In this way, the pellets 19 are plasticized and supplied to the nozzle 10a through the communication hole 5a and discharged from the nozzle 10a.

[0025] As shown in FIG. 5 and other figures, a communication hole 5a, which is a movement path of the molten pellets 19, is formed in the center Cp of the barrel 5 in a plan view. As shown in FIG. 2, the communication hole 5a is connected to a nozzle 10a of a discharge unit 10 that discharges the modeling material. A filter (not shown) is provided in the communication hole 5a. Although not formed in the barrel 5 of this embodiment, a groove connected to the communication hole 5a may be formed in the opposing surface 8 of the barrel 5. By forming a groove connected to the communication hole 5a in the opposing surface 8, the modeling material may be more likely to gather toward the communication hole 5a.

[0026] Here, the discharge unit 10 is configured to be able to continuously discharge the plasticized modeling material in a fluid state from the nozzle 10a. As shown in FIG. 2, the discharge unit 10 is provided with a heater 9 for adjusting the modeling material to a desired viscosity. The modeling material discharged from the discharge unit 10 is discharged in a linear shape. Then, the modeling layer 500 is formed by discharging the modeling material in a linear shape from the discharge unit 10.

[0027] The three-dimensional modeling apparatus 1 of this embodiment includes a material supplying means 30 having a hopper 2, a supply pipe 3, a screw 4, a barrel 5, a drive motor 6, and a discharge unit 10. The three-dimensional modeling apparatus 1 of this embodiment includes one each of a first material supplying means 30A that discharges a first material Oa and a second material supplying means 30B that discharges a second material Ob, but may include a plurality of at least one of the first material supplying means 30A and the second material supplying means 30B.

[0028] As shown in FIG. 1, the three-dimensional modeling apparatus 1 of this embodiment includes a stage unit 22 for placing the modeling layer 500 formed by discharging from the material supply means 30. The stage unit 22 includes a base portion 221, a first table 222, a second table 223, and a third table 224. The first table 222 has a size in the Y-axis direction that extends from the modeling layer formation region 24 by the material supply means 30 to a laser irradiation region 25 by the laser irradiation means 28, the details of which will be described later. Under the control of the control unit 23, the second table 223 can be moved along the Y-axis direction relative to the first table 222 by a motor 225. Under the control of the control unit 23, the third table 224 can be moved along the X-axis direction relative to the second table 223 by a motor 226. Note that there is no particular limitation on the configuration of the stage unit 22. For example, a table and a motor for moving the second table 223 and the third table 224 from the modeling layer formation region 24 to the laser irradiation region 25 may be provided separately.

[0029] In the three-dimensional modeling apparatus 1 of this embodiment, the second table 223 moves along the Y-axis direction relative to the first table 222, thereby making it possible to move the second table 223 and the third table 224 from the modeling layer formation region 24 to the laser irradiation region 25. The second table 223 and the third table 224 are positioned in the modeling layer formation region 24, and the modeling layer 500 is formed by the material supply means 30, and the second table 223 and the third table 224 are positioned in the laser irradiation region 25, and the laser irradiation is performed by the laser irradiation means 28.

[0030] The material supplying means 30 is configured to be movable along the Z-axis direction by a motor (not shown) in the modeling layer forming region 24 as the modeling layers 500 are stacked, and the laser irradiating means 28 is also configured to be movable along the Z-axis direction by a motor (not shown) in the laser irradiation region 25 as the modeling layers 500 are stacked. The three-dimensional modeling apparatus 1 of this embodiment is configured in this way, so that the modeling layer 500 can be formed on the third table 224 while the stage unit 22 and the material supplying means 30 are moved relative to each other in the modeling layer forming region 24, and the laser L can be irradiated at a desired position on the modeling layer 500 formed on the third table 224 while the stage unit 22 and the laser irradiating means 28 are moved relative to each other in the laser irradiation region 25. The control of the arrangement of the stage unit 22 and the material supplying means 30 and the control of the arrangement of the stage unit 22 and the laser irradiating means 28 are both performed by the control unit 23.

[0031] As shown in FIG. 1, the laser irradiation means 28 includes a laser irradiation unit 281 and a galvanometer mirror 282. The laser irradiation means 28 radiates the laser L by oscillating the laser L of a predetermined output from the laser irradiation unit 281 based on a control signal from the control unit 23. The laser L is irradiated to the modeling layer 500, and sinters and solidifies, for example, metal powder contained in the modeling layer 500. At the same time, the binder contained in the modeling layer 500 is evaporated by the heat of the laser L. There is no particular limitation on the laser L, but a fiber laser is preferably used because of its advantage of high metal absorption efficiency. A YAG laser equipped with a Q switch and pulse-controlled may also be used.

[0032] Here, the first material Oa and the second material Ob are not particularly limited, but a resin can be preferably used as the first material Oa. In the three-dimensional modeling apparatus 1 of this embodiment, when an upper layer is laminated on a lower resin layer using a resin as the first material Oa and the upper layer is irradiated with a laser L, the lower resin layer can be prevented from being deformed by heat from the laser L.

[0033] Moreover, metal or ceramic can be preferably used as the second material Ob. The three-dimensional modeling apparatus 1 of this embodiment can suppress deformation of the lower layer due to heat from the laser L when a metal layer or ceramic layer is laminated on a lower layer and the metal layer or ceramic layer is irradiated with a laser L. In particular, when the lower layer is a resin layer, the three-dimensional modeling apparatus 1 of this embodiment can particularly effectively suppress deformation of the lower resin layer due to heat from the laser L when a metal layer or ceramic layer is laminated on the lower resin layer and the metal layer or ceramic layer is irradiated with a laser L.

[0034] However, as described above, there is no particular limitation on the first material Oa and the second material Ob, and any of metal, ceramic, resin, etc. may be used, or two or more of them may be mixed and used, provided that the sintering temperature of the second material Ob is higher than the melting point of the first material Oa.

[0035] Specifically, examples of metals or ceramics that can be used for the first material Oa and the second material Ob include various metals such as aluminum, titanium, iron, copper, magnesium, stainless steel, and maraging steel; various metal oxides such as silica, alumina, titanium oxide, zinc oxide, zircon oxide, tin oxide, magnesium oxide, and potassium titanate; various metal hydroxides such as magnesium hydroxide, aluminum hydroxide, and calcium hydroxide; various metal nitrides such as silicon nitride, titanium nitride, and aluminum nitride; various metal nitrides such as silicon carbide, titanium carbide, and aluminum nitride; various metal carbides such as silicon carbide and titanium carbide; various metal sulfides such as zinc sulfide; various metal carbonates such as calcium carbonate and magnesium carbonate; various metal sulfates such as calcium sulfate and magnesium sulfate; various metal silicates such as calcium silicate and magnesium silicate; various metal phosphates such as calcium phosphate; various metal borates such as aluminum borate and magnesium borate; and composite compounds thereof; and gypsum (hydrates of calcium sulfate and anhydrous calcium sulfate).

[0036] Examples of resins that can be used for the first material Oa and the second material Ob include, for example, acrylic resin, epoxy resin, silicone resin, cellulose-based resin, and synthetic resin. Examples of resins that can be used include thermoplastic resins such as PLA (polylactic acid), PA (polyamide), and PPS (polyphenylene sulfide). When using a resin as the second material Ob to be sintered by laser irradiation, a heat-resistant resin called a super engineering plastic such as PEEK (polyethyl ether ketone) can be preferably used. The resin may be in a pellet state containing the resin together with metal or ceramic. Instead of being in a pellet state, the metal, ceramic, or resin may be dissolved or dispersed in a solvent or dispersion medium in the form of fine particles. The solvent or dispersion medium or binder is usually dried and removed before irradiation with the laser L, or is decomposed and disappears with irradiation with the laser L.

[0037] Examples of the solvent or dispersion medium include various types of water such as distilled water, pure water, and RO water, as well as alcohols such as methanol, ethanol, 2-propanol, 1-butanol, 2-butanol, octanol, ethylene glycol, diethylene glycol, and glycerin, ethers (cellosolves) such as ethylene glycol monomethyl ether (methyl cellosolve), esters such as methyl acetate, ethyl acetate, butyl acetate, and ethyl formate, ketones such as acetone, methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone, methyl isopropyl ketone, and cyclohexanone, aliphatic hydrocarbons such as pentane, hexane, and octane, cyclic hydrocarbons such as cyclohexane and methylcyclohexane, benzene, and the like. Examples of the solvent include aromatic hydrocarbons having a long chain alkyl group and a benzene ring, such as toluene, xylene, hexylbenzene, heptylbenzene, octylbenzene, nonylbenzene, decylbenzene, undecylbenzene, dodecylbenzene, tridecylbenzene, and tetradecylbenzene; halogenated hydrocarbons, such as methylene chloride, chloroform, carbon tetrachloride, and 1,2-dichloroethane; aromatic heterocycles containing any one of pyridine, pyrazine, furan, pyrrole, thiophene, and methylpyrrolidone; nitriles, such as acetonitrile, propionitrile, and acrylonitrile; amides, such as N,N-dimethylamide and N,N-dimethylacetamide; carboxylates, and various other oils. The solvent or dispersion medium is usually removed by drying before irradiation with the laser L.

[0038] Next, an example of a three-dimensional printing method executed by the above-mentioned three-dimensional printing apparatus 1 will be described using the flowchart of Fig. 7 with reference to Fig. 6. In the three-dimensional printing method of this embodiment, first, in step S110, the three-dimensional printing apparatus 1 inputs printing data from an external computer (not shown) or the like.

[0039] Next, in step S120, one modeling layer 500 is formed based on the modeling data input in step S110. Here, the top state diagram in Fig. 6 shows a state in which the first modeling layer 501 made of the first material Oa is formed on the third table 224 by the first material supply means 30A. Note that, in the top state diagram in Fig. 6, the first modeling layer 501 made of only the first material Oa is formed on the third table 224, but there are also cases in which the first modeling layer 501 made of the first material Oa and the second material Ob is formed on the third table 224, and cases in which the first modeling layer 501 made of only the second material Ob is formed on the third table 224.

[0040] Next, in step S130, the control unit 23 determines whether or not to irradiate the laser L to the modeling layer 500 formed in step S120. In this embodiment, the first material Oa is a resin, the second material Ob is a metal, and the laser L is irradiated only to the portion of the modeling layer 500 formed with the second material Ob. For this reason, for example, if the first modeling layer 501 is formed only with the first material Oa in step S120, the control unit 23 determines not to irradiate the laser L to the modeling layer 501. If it is determined in this step that the laser L is to be irradiated, the process proceeds to step S140, and if it is determined in this step that the laser L is not to be irradiated, the process proceeds to step S170.

[0041] In step S140, the control unit 23 determines whether the lower layer immediately below the modeling layer 500 immediately after the formation in step S120 is a layer formed of the first material Oa. This "layer formed of the first material Oa" also includes a case where only a part of the layer is formed of the first material Oa. If it is determined in this step that the lower layer is not a layer formed of the first material Oa, the process proceeds to step S150, where the modeling layer 500 immediately after the formation in step S120 is irradiated with a laser in the first laser irradiation mode. On the other hand, if it is determined in this step that the lower layer is a layer formed of the first material Oa, the process proceeds to step S160, where the modeling layer 500 immediately after the formation in step S120 is irradiated with a laser in the second laser irradiation mode.

[0042] Steps S150 and S160 are both steps for sintering the modeling layer 500 immediately after it is formed in step S120. More specifically, these are steps for sintering the modeling layer 500 immediately after it is formed in step S120 without melting the lower layer. When the second material Ob is a metal or ceramic, the metal or ceramic is sintered in step S150 or step S160. When the second material Ob is a resin, for example, when a super engineering plastic is used as the resin, the resin is sintered in step S150 or step S160. In this embodiment, the first material Oa is not sintered, but the first material Oa may also be sintered by irradiating the laser L to the first material Oa.

[0043] Here, the first laser irradiation mode is a normal state laser irradiation mode, and the second laser irradiation mode is a laser irradiation mode in which heat diffusion to the lower layer is less than that in the first laser irradiation mode. Specifically, the second laser irradiation mode is a laser irradiation mode that uses a laser with a shorter pulse width than that in the first laser irradiation mode. After the end of step S150 and the end of step S160, the process proceeds to step S170.

[0044] In step S170, the control unit 23 judges whether or not all three-dimensional modeling based on the modeling data input in step S110 has been completed. If it is judged that all three-dimensional modeling based on the modeling data input in step S110 has been completed, the three-dimensional modeling method of this embodiment is terminated. On the other hand, if it is judged that all three-dimensional modeling based on the modeling data input in step S110 has not been completed, the process returns to step S120, and steps S120 to S170 are repeated until it is judged that all three-dimensional modeling based on the modeling data input in step S110 has been completed.

[0045] Here, the second state diagram from the top in FIG. 6 shows a state in which the first modeling layer 501 as the first material modeling layer is modeled, and then the second modeling layer 502 is formed on the modeling layer 501 by the first material supply means 30A. The third state diagram from the top in FIG. 6 shows a state in which the second modeling layer 502 is formed on the modeling layer 501 by the second material supply means 30B, adjacent to the first material Oa, with the second material Ob. In this way, the modeling layer 502 includes a portion formed with the second material Ob. The modeling layer 502 of the modeling layer 500 that includes a portion formed with the second material Ob is determined as the second material modeling layer. For this reason, it is determined that the laser L is irradiated to the portion formed with the second material Ob in step S130 for the modeling layer 502 as the second material modeling layer. In addition, since the modeling layer 501 below the modeling layer 502 is the modeling layer 500 formed from the first material Oa, in step S140, the modeling layer 502 is irradiated with a laser in the second laser irradiation mode. The state diagram at the bottom of Fig. 6 shows a state in which the modeling layer 502 is irradiated with a laser in the second laser irradiation mode.

[0046] In this way, the control unit 23 selects between the first laser irradiation mode and the second laser irradiation mode to control the laser irradiation means 28. When the laser L is to be irradiated from the laser irradiation means 28 to a first material modeling layer formed by supplying a first material Oa onto the stage, such as modeling layer 501 in Fig. 6, and a second material modeling layer formed by supplying a second material Ob, such as modeling layer 502 in Fig. 6, the control unit 23 selects the second laser irradiation mode to control the laser irradiation means 28.

[0047] Thus, the three-dimensional modeling apparatus 1 of this embodiment has, in addition to the first laser irradiation mode, a second laser irradiation mode in which heat diffusion to the lower layer is less than that in the first laser irradiation mode. When the laser irradiation means 28 irradiates a laser onto a second material modeling layer, which is an upper layer formed by supplying a second material Ob having a sintering temperature higher than the melting point of the first material Oa, on a first material modeling layer, which is a lower layer formed by supplying a first material Oa onto a stage, the second laser irradiation mode is selected. Therefore, the three-dimensional modeling apparatus 1 of this embodiment can prevent the heat of the laser L from being transmitted to the lower layer when irradiating the laser L onto the upper layer, which has a sintering temperature higher than the melting point of the lower layer. Therefore, the three-dimensional modeling apparatus 1 of this embodiment can suppress deformation of the first material modeling layer due to heat from the laser L when stacking the second material modeling layer on the first material modeling layer and irradiating the second material modeling layer with the laser L.

[0048] As described above, in the three-dimensional modeling apparatus 1 of this embodiment, the second laser irradiation mode uses a laser L with a shorter pulse width than the first laser irradiation mode. By using a laser L with a shorter pulse width, it is possible to reduce the diffusion of heat. This is because the shorter the pulse width, the more pinpoint energy can be concentrated. Therefore, when the second material modeling layer is stacked on the first material modeling layer and the second material modeling layer is irradiated with the laser L, the three-dimensional modeling apparatus 1 of this embodiment can suppress deformation of the first material modeling layer due to the heat from the laser L.

[0049] Furthermore, the three-dimensional modeling apparatus 1 of this embodiment can use a laser L having a top-hat shaped energy intensity distribution in the second laser irradiation mode, and a laser L having a Gaussian distribution energy intensity distribution in the first laser irradiation mode. Fig. 8 is a graph showing an example of the energy intensity distribution of a laser L having a top-hat shaped energy intensity distribution and a laser L having a Gaussian distribution energy intensity distribution.

[0050] Here, the laser L having a top-hat shaped energy intensity distribution is formed by incorporating a lens system (means for converting a Gaussian distribution to a top-hat shaped distribution) using a diffractive optical element (DOE) or the like capable of converting a laser profile to a top-hat distribution into the optical system of a laser light source having a Gaussian distribution generally adopted in the SLS (selective laser sintering) method or the SMS (selective mask sintering) method. However, there is no particular limitation on the lens system and it can be appropriately selected according to the purpose. For example, a device named StarLite manufactured by OPHIR can be used.

[0051] By using a laser L having an energy intensity distribution in a top hat shape, the thermal energy can be uniformly applied to a meltable region of a certain width, and the supply of excessive thermal energy as in the Gaussian distribution can be suppressed, and the diffusion of heat over a wide range can be suppressed, compared with the case of using a laser L having an energy intensity distribution in a Gaussian distribution. As shown in the energy distribution shown in FIG. 8 and the graph of the heat distribution in the depth direction of the material shown in FIG. 9, by using a laser L having an energy intensity distribution in a top hat shape, the thermal energy required for melting can be uniformly applied to a meltable region of a certain width, and the supply of excessive thermal energy as in the Gaussian distribution can be suppressed, and the diffusion of heat over a wide range can be suppressed. For this reason, the three-dimensional modeling apparatus 1 of this embodiment can suppress the deformation of the first material modeling layer due to the heat from the laser L when the second material modeling layer is stacked on the first material modeling layer and the second material modeling layer is irradiated with the laser L.

[0052] As described above, the three-dimensional modeling apparatus 1 of this embodiment is configured to be able to adopt a method of changing the pulse width and a method of changing the pulse shape in the first laser irradiation mode and the second laser irradiation mode in which heat is less diffused to the surroundings than in the first laser irradiation mode. However, it may be configured to adopt only one of these methods, or to adopt another method.

[0053] The present invention is not limited to the above-mentioned embodiments, and can be realized in various configurations without departing from the spirit of the present invention. The technical features in the embodiments corresponding to the technical features in each aspect described in the Summary of the Invention can be appropriately replaced or combined in order to solve some or all of the above-mentioned problems or to achieve some or all of the above-mentioned effects. Furthermore, if a technical feature is not described as essential in this specification, it can be appropriately deleted. [Explanation of symbols]

[0054] 1...three-dimensional modeling device, 2...hopper, 3...supply pipe, 4...screw, 4a...circumferential surface, 4b...groove, 4d...rib, 5...barrel, 5a...communicating hole, 6...driving motor, 7...heating section, 8...opposing surface, 9...heater, 10...discharge section, 10a...nozzle, 18...groove forming surface, 19...pellets, 19A...pellets, 19B...pellets, 22...stage unit (stage), 23...control section, 24...modeling layer forming area, 25...laser irradiation area, 28...laser irradiation means, 30...material supply means, 30A...first material supply means, 30B...second material supply means, 221...base portion, 222...first table, 223...second table, 224...third table, 225...motor, 226...motor, 281...laser irradiation portion, 282...galvanometer mirror, 500...modeling layer, 501...first modeling layer (first material modeling layer), 502...second modeling layer (second material modeling layer), Cp...center portion, O...three-dimensional object, Oa...first material, Ob...second material

Claims

1. A three-dimensional modeling apparatus for manufacturing a three-dimensional object by stacking a modeling layer on a lower layer, comprising: Stage and A first material supplying means for supplying a first material; a second material supplying means for supplying a second material having a sintering temperature higher than the melting point of the first material; A laser irradiation means; a control unit that selects a first laser irradiation mode and a second laser irradiation mode in which heat diffusion to the lower layer is smaller than that in the first laser irradiation mode, and controls the laser irradiation means; Equipped with the control unit selects the second laser irradiation mode to control the laser irradiation means when irradiating a laser from the laser irradiation means to a second material modeling layer serving as the modeling layer formed by supplying the second material onto a first material modeling layer serving as the modeling layer formed by supplying the first material onto the stage, and The three-dimensional modeling apparatus, wherein the second laser irradiation mode uses a laser having a shorter pulse width than that of the first laser irradiation mode.

2. In the three-dimensional printing apparatus according to claim 1, The control unit determines whether the lower layer is a layer formed of the first material, and if it determines that the lower layer is not a layer formed of the first material, controls the laser irradiation to be performed on the modeling layer in the first laser irradiation mode, and if it determines that the lower layer is a layer formed of the first material, controls the laser irradiation to be performed on the modeling layer in the second laser irradiation mode.

3. 3. The three-dimensional modeling apparatus according to claim 1, The three-dimensional modeling apparatus, wherein the first material is a resin.

4. The three-dimensional modeling apparatus according to claim 1 , The three-dimensional modeling apparatus is characterized in that the second material is a metal or a ceramic.

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