Three dimensional shaping apparatus and method for manufacturing three dimensional object

Abstract

To provide a technique capable of improving at least one of high accuracy and high speed in shaping a three dimensional shaped article.SOLUTION: The three-dimensional shaping apparatus includes a plasticizing unit that plasticizes a material to generate a shaping material, a nozzle that discharges the shaping material toward a stage, and a control unit that controls shaping of a three-dimensional shaped object by discharging the shaping material from the nozzle, wherein the plasticizing unit includes a drive motor, a screw, a barrel, a heating unit, and a position changing mechanism that changes a relative position between the screw and the barrel. The control unit causes the plasticizing unit to generate the shaping material by setting the distance between the screw and the barrel to a first distance by the position changing mechanism when the condition related to shaping is a first condition, and causes the plasticizing unit to generate the shaping material by setting the distance between the screw and the barrel to a second distance by the position changing mechanism when the condition is a second condition, and the second distance is larger than the first distance.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a three-dimensional printing apparatus and a method for manufacturing a three-dimensional object. [Background technology]

[0002] Patent Document 1 discloses that in a three-dimensional modeling apparatus, the amount of modeling material discharged is controlled in accordance with the moving speed of the nozzle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-82558 Summary of the Invention [Problem to be solved by the invention]

[0004] In the fabrication of three-dimensional objects, there is room for improvement in at least one of increasing precision and increasing speed. [Means for solving the problem]

[0005] According to a first aspect of the present disclosure, there is provided a three-dimensional modeling apparatus, the three-dimensional modeling apparatus comprising: a plasticizing unit that plasticizes a material to generate a modeling material; a nozzle that discharges the modeling material toward a stage; and a control unit that controls the formation of a three-dimensional object by discharging the modeling material from the nozzle, the plasticizing unit comprising: a drive motor; a screw that is rotated by the drive motor and has a groove-forming surface with a ridge formed from a center portion to an outer periphery; a barrel that faces the groove-forming surface and has a communication hole that communicates with the nozzle at a position facing the center portion of the groove-forming surface; and a pressure vessel that is provided between the screw and the barrel. The system has a heating unit that heats the supplied material and a position change mechanism that changes the relative position of the screw and the barrel, and when the molding condition is a first condition, the control unit uses the position change mechanism to set the distance between the screw and the barrel to a first distance and cause the plasticization unit to generate the molding material, and when the condition is a second condition, the control unit uses the position change mechanism to set the distance between the screw and the barrel to a second distance and cause the plasticization unit to generate the molding material, the second distance being greater than the first distance.

[0006] According to a second aspect of the present disclosure, there is provided a method for manufacturing a three-dimensional object. This manufacturing method includes a generating step of generating a modeling material by plasticizing a material using a plasticizing unit, and a modeling step of discharging the modeling material from a nozzle to form a three-dimensional object. The plasticizing unit includes a drive motor, a screw that is rotated by the drive motor and has a groove-forming surface with a ridge formed from a center portion to an outer periphery, a barrel that faces the groove-forming surface and has a communication hole that communicates with the nozzle at a position facing the center portion of the groove-forming surface, and a heating element that heats the material supplied between the screw and the barrel. The device has a heating section and a position change mechanism that changes the relative position of the screw and the barrel, and in the generation process, when the condition related to the molding is a first condition, the position change mechanism sets the distance between the screw and the barrel to a first distance and causes the plasticization section to generate the molding material, and when the condition is a second condition, the position change mechanism sets the distance between the screw and the barrel to a second distance and causes the plasticization section to generate the molding material, the second distance being greater than the first distance. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram illustrating a schematic configuration of a three-dimensional modeling apparatus. [Figure 2] FIG. 2 is a cross-sectional view showing a schematic configuration of a plasticizing section. [Figure 3] FIG. 2 is a perspective view showing a schematic configuration of a screw. [Figure 4] FIG. [Figure 5] 1A to 1C are diagrams illustrating examples of materials used in forming a three-dimensional object. [Figure 6] 10 is a flowchart of a three-dimensional modeling process. DETAILED DESCRIPTION OF THE INVENTION

[0008] A. First embodiment: FIG. 1 is a diagram showing a schematic configuration of a three-dimensional printing apparatus 10 according to the first embodiment. In FIG. 1, arrows are shown along the X, Y, and Z directions, which are orthogonal to each other. The X, Y, and Z directions in FIG. 1 and the X, Y, and Z directions in other figures represent the same directions. Hereinafter, the +Z direction will be referred to as "up" and the -Z direction will be referred to as "down."

[0009] The three-dimensional modeling apparatus 10 includes a discharge unit 100, a movement mechanism unit 210, a stage 220, a chamber 20, and a control unit 30.

[0010] The discharge unit 100 includes a plasticizer 110, a material storage unit 102, and a nozzle 104. The material storage unit 102 is, for example, a hopper. In this embodiment, pellet-shaped resin is stored in the material storage unit 102 as the material. The material may be pressure-fed to the material storage unit 102 from an external source via a tube. The plasticizer 110 plasticizes at least a portion of the material supplied from the material storage unit 102 to generate a modeling material. The modeling material generated by the plasticizer 110 is supplied to the nozzle 104 and discharged from the nozzle 104 toward a modeling surface located on the upper surface of the stage 220. In this embodiment, "plasticization" refers to a change from a solid to a fluid state, including melting. Specifically, for a material that undergoes glass transition, plasticization refers to raising the temperature of the material above its glass transition point. For a material that does not undergo glass transition, plasticization refers to raising the temperature of the material above its melting point.

[0011] The movement mechanism 210 changes the relative position between the discharge unit 100 and the stage 220. In this embodiment, the movement mechanism 210 moves the stage 220 relative to the discharge unit 100. In this embodiment, the movement mechanism 210 is configured by a three-axis positioner that moves the stage 220 in three axial directions, that is, the X, Y, and Z directions, using the driving forces of three motors. Each motor is driven under the control of the control unit 30. Note that in other embodiments, the movement mechanism 210 may not be configured to move the stage 220, but may be configured to move the discharge unit 100 without moving the stage 220, for example. Alternatively, the movement mechanism 210 may be configured to move both the stage 220 and the discharge unit 100.

[0012] The chamber 20 has a modeling space 21 therein. The modeling space 21 accommodates a discharge unit 100, a movement mechanism unit 210, and a stage 220. The chamber 20 may be provided with a heater that heats the modeling space 21.

[0013] The control unit 30 is configured by a computer having one or more processors, a storage device, and an input / output interface for inputting and outputting signals to and from the outside. The processor executes programs and instructions stored in the storage device, causing the control unit 30 to control the plasticizing unit 110 and the movement mechanism unit 210. The control unit 30 controls the movement mechanism unit 210 to move the stage 220, while controlling the plasticizing unit 110 to dispense the modeling material, thereby stacking multiple layers on the stage 220 and forming a three-dimensional model. Note that the control unit 30 may be configured by a combination of multiple circuits rather than a computer.

[0014] 2 is a cross-sectional view showing a schematic configuration of the plasticizing unit 110. The plasticizing unit 110 includes a drive motor 112, a reducer 114, a screw shaft 116, a screw 140, a barrel 150, and a heating unit 158. These are housed in or fixed to a housing 200. The housing 200 includes a first housing 201 and a second housing 202. The drive motor 112 and the reducer 114 are attached to the top of the first housing 201. The second housing 202 houses the screw 140. The barrel 150 is fixed to the bottom of the second housing 202.

[0015] The drive motor 112 is a motor for rotating the screw 140. The drive motor 112 is controlled by the control unit 30.

[0016] The reducer 114 is a device that reduces the rotational speed of the output shaft of the drive motor 112 according to a predetermined reduction ratio and outputs the reduced rotational speed. As the reducer 114, for example, a planetary gear reducer or a wave gear reducer is used.

[0017] The screw shaft 116 is connected to the upper surface of the screw 140. The surface of the screw 140 to which the screw shaft 116 is connected is called a connection surface 141. The screw shaft 116 is rotated by the drive motor 112. More specifically, the screw shaft 116 is rotated by the drive motor 112 via a reducer 114 connected to the drive motor 112. A bearing 170 is provided on the outer periphery of the screw shaft 116. The bearing 170 is disposed inside the first housing 201, and supports the screw shaft 116 rotatably relative to the first housing 201.

[0018] The output shaft 115 of the reducer 114 and the screw shaft 116 are connected via a connecting portion 180 that constitutes a coupling. The screw shaft 116 has a cylindrical shape with an internal space. A flange portion 117 is provided at the lower end of the screw shaft 116. The screw shaft 116 and the screw 140 are connected by a bolt that passes through the flange portion 117. The connecting portion 180, the screw shaft 116, and the screw 140 are integrally connected by a connecting bolt 181 that passes through their centers. The screw 140 has a groove forming surface 148 on the surface opposite to the connection surface 141, i.e., the lower surface.

[0019] A barrel 150 is disposed below the screw 140. A communication hole 156 that communicates with the nozzle 104 is formed in the barrel 150. The barrel 150 has an opposing surface 152 that faces the groove forming surface 148 of the screw 140. The groove forming surface 148 and the opposing surface 152 are spaced apart by a distance L1.

[0020] The distance L1 between the groove forming surface 148 and the opposing surface 152 can be adjusted by a position changing mechanism 120 that changes the relative position of the screw 140 and the barrel 150. The position changing mechanism 120 moves the first housing 201 relative to the second housing 202 in the +Z direction to lift the screw 140 with respect to the barrel 150 and adjust the distance L1 between the groove forming surface 148 and the opposing surface 152. The position changing mechanism 120 is configured, for example, by a linear actuator driven by hydraulics or a motor. The position changing mechanism 120 is controlled by the control unit 30. The control unit 30 controls the position changing mechanism 120 to adjust the distance L1, for example, between 30 μm and 500 μm.

[0021] A heating unit 158 ​​is embedded in the barrel 150. The heating unit 158 ​​is configured by, for example, a rod-shaped heater or an annular heater. The heating unit 158 ​​heats the material supplied between the screw 140 and the barrel 150. Heating by the heating unit 158 ​​is controlled by the control unit 30.

[0022] The second housing 202 is provided with a material supply path 196 that supplies material between the screw 140 and the barrel 150. The material supply path 196 is connected to the material storage unit 102 shown in FIG. 1. The material is supplied between the screw 140 and the barrel 150 from the material storage unit 102 through the material supply path 196.

[0023] FIG. 3 is a perspective view showing a schematic configuration of the screw 140. In FIG. 3, the screw 140 is shown upside down. In FIG. 3, the position of the central axis RX of the screw 140 is indicated by a dashed line. The screw 140 has a generally cylindrical shape in which the height along the central axis RX is smaller than the diameter. The screw 140 has a groove-forming surface 148 facing the opposing surface 152 of the barrel 150. A groove 142 is provided in the groove-forming surface 148. A central portion 146 of the groove-forming surface 148 is configured as a recess to which one end of the groove 142 is connected. The central portion 146 faces the communication hole 156 of the barrel 150 shown in FIG. 2.

[0024] The grooves 142 of the screw 140 form what is known as scroll grooves. The grooves 142 extend spirally from a central portion 146 toward the outer periphery of the screw 140, drawing an arc. The grooves 142 may be configured to extend in an involute curve or a spiral. The groove forming surface 148 is provided with ridges 143 that form the side walls of the grooves 142 and extend along each groove 142. The grooves 142 continue to a material inlet 144 formed on the side surface of the screw 140. This material inlet 144 is a portion that receives material supplied via a material supply path 196.

[0025] FIG. 3 shows an example of a screw 140 having three grooves 142 and three ridges 143. The number of grooves 142 and ridges 143 provided on the screw 140 is not limited to three, and only one groove 142 may be provided, or two or more grooves 142 may be provided. FIG. 3 also shows an example of a screw 140 in which three material inlets 144 are formed. The number of material inlets 144 provided on the screw 140 is not limited to three, and may be only one, or two or more. The screw 140 is also called a flat screw or a rotor.

[0026] FIG. 4 is a top view of the barrel 150. The barrel 150 has an opposing surface 152 that faces the groove-forming surface 148 of the screw 140. A communication hole 156 that communicates with the nozzle 104 is formed in the center of the opposing surface 152. A plurality of guide grooves 154 are formed around the communication hole 156 in the opposing surface 152. One end of each guide groove 154 is connected to the communication hole 156 and extends in a spiral shape from the communication hole 156 toward the outer periphery of the opposing surface 152. Each guide groove 154 has the function of guiding the molding material to the communication hole 156. Note that one end of the guide groove 154 does not have to be connected to the communication hole 156. Furthermore, the barrel 150 does not necessarily have to have a guide groove 154 formed therein.

[0027] The material supplied into the groove 142 of the screw 140 is melted in the groove 142 and flows along the groove 142 as the screw 140 rotates, and is guided to the center 146 of the screw 140 as a modeling material. The pasty modeling material that has flowed into the center 146 and exhibits fluidity flows into the nozzle 104 through the communication hole 156 provided in the center of the barrel 150 and is ejected from the nozzle 104 toward the stage 220. Note that it is not necessary for all types of substances constituting the modeling material to be melted. It is sufficient for the modeling material to be converted into a fluid state as a whole by melting at least some of the types of substances constituting the modeling material. The modeling material is also called a plasticized material.

[0028] FIG. 5 shows examples of materials used in the creation of a three-dimensional object. The three-dimensional modeling apparatus 10 of this embodiment uses materials such as acrylonitrile butadiene styrene (ABS), ABS containing carbon filler, acrylic-containing polypropylene (PP), polybutylene terephthalate (PET), polyether ether ketone (PEEK), and polyvinyl alcohol (PVA). The acrylic-containing PP is an example of a bioplastic. FIG. 5 also shows the thermal conductivity, density, specific heat, melt flow rate (MFR), and solubility parameter (SP value) of each material. For the carbon filler-containing ABS, the carbon filler content is shown, and for the acrylic-containing PP, the acrylic content is shown. MFR is an index that represents the flowability, or viscosity, of a material. A smaller value indicates a material that is less likely to flow and has a higher viscosity. The unit of MFR, [g / 10 min], indicates the mass of plasticized material that flows in 10 minutes. MFR is measured, for example, using a melt flow rate tester. The SP value is a physical property defined as the square root of the cohesive energy density, and is a numerical value that indicates the dissolution behavior of a solvent. In this embodiment, the SP value is used as an index representing the adhesiveness of a material. The closer the SP value is to the SP value of water (23.4), the higher the wettability and adhesiveness.

[0029] 6 is a flowchart of the three-dimensional modeling process executed by the control unit 30. In step S10, the control unit 30 acquires modeling data. The control unit 30 acquires the modeling data from, for example, a storage device or recording medium provided in the control unit 30, or a computer communicably connected to the control unit 30. The modeling data records the movement path of the nozzle 104 and the amount of modeling material dispensed along each movement path.

[0030] In step S20, the control unit 30 acquires the modeling conditions. In this embodiment, the modeling conditions are recorded in the modeling data. Therefore, the control unit 30 acquires the modeling conditions from the modeling data. The modeling conditions are conditions that affect the modeling quality and modeling speed of a three-dimensional model. The modeling conditions include, for example, at least one of: (1) a condition related to modeling accuracy; (2) a condition related to modeling speed; (3) a condition related to the viscosity of the modeling material; (4) a condition related to the adhesiveness of the modeling material; (5) a condition related to the thermal conductivity of the modeling material; (6) a condition related to the density of the modeling material; (7) a condition related to the specific heat of the modeling material; and (8) a condition related to the size of the material. The control unit 30 may receive the modeling conditions from a user via a predetermined input interface connected to the control unit 30.

[0031] In step S30, the control unit 30 changes the relative positions of the screw 140 and the barrel 150 according to the conditions acquired in step S20. When the condition related to the shaping is the first condition, the control unit 30 sets the distance between the screw 140 and the barrel 150 to a first distance. When the condition related to the shaping is the second condition, the control unit 30 sets the distance between the screw 140 and the barrel 150 to a second distance that is greater than the first distance. In the first embodiment, the condition related to the shaping is a condition related to shaping accuracy, and the second condition is a condition that provides higher shaping accuracy than the first condition. Therefore, in this embodiment, the higher the condition related to the shaping accuracy, the greater the distance between the screw 140 and the barrel 150.

[0032] In step S40, the control unit 30 controls the plasticizing unit 110 to start generating the modeling material. The process of generating the modeling material is called the generation process. In the generation process, in step S30, the distance between the screw 140 and the barrel 150 is adjusted, and then the modeling material is generated.

[0033] In step S50, the control unit 30 controls the movement mechanism unit 210 to move the nozzle 104 according to the movement path included in the modeling data, and discharges the modeling material from the nozzle 104 according to the discharge amount included in the modeling data, thereby forming a three-dimensional model on the stage 220. Step S50 is also referred to as a modeling process.

[0034] As described above, in the first embodiment, the distance between the screw 140 and the barrel 150 can be changed depending on the modeling conditions, thereby improving at least one of precision and speed in the modeling of a three-dimensional object. In particular, in this embodiment, the modeling conditions are conditions related to modeling precision, and the control unit 30 increases the distance between the screw 140 and the barrel 150 as the modeling precision increases. In this way, increasing the distance between the screw 140 and the barrel 150 reduces the pressure of the modeling material generated in the plasticization unit 110 and the discharge speed of the modeling material from the nozzle 104. As a result, a three-dimensional object can be modeled with high precision.

[0035] Increasing the distance between the screw 140 and the barrel 150 generally reduces the internal pressure and the amount of modeling material discharged. To discharge the same flow rate of modeling material when the distance between the screw 140 and the barrel 150 is large as when the distance between the screw 140 and the barrel 150 is small, simply increase the rotation speed of the screw 140. Increasing the rotation speed of the screw 140 reduces the effect of temperature variations in the barrel 150 during plasticization of the material, thereby reducing plasticization variations. Therefore, increasing the distance between the screw 140 and the barrel 150 and increasing the rotation speed of the screw 140 can stabilize the line width of the modeling material discharged from the nozzle 104 compared to decreasing the distance between the screw 140 and the barrel 150. Furthermore, increasing the distance between the screw 140 and the barrel 150 reduces the resistance of the material, allowing the screw 140 to rotate more easily even with a small torque of the drive motor 112. Therefore, increasing the distance between the screw 140 and the barrel 150 reduces the possibility that the drive motor 112 will be overloaded and stalled due to material resistance.

[0036] B. Second embodiment: The configuration of the three-dimensional printing apparatus 10 in the second embodiment is the same as that in the first embodiment. In the second embodiment, in step S20 of the three-dimensional printing process shown in Fig. 6, the control unit 30 acquires a condition related to the printing speed as a condition related to printing.

[0037] In step S30, when the condition related to the molding speed is the first condition, the control unit 30 sets the distance between the screw 140 and the barrel 150 to a first distance. When the condition related to the molding speed is the second condition, the control unit 30 sets the distance between the screw 140 and the barrel 150 to a second distance that is larger than the first distance. In this embodiment, the second condition is a condition in which the molding speed is faster than the first condition. Therefore, in this embodiment, the faster the molding speed is, the smaller the distance between the screw 140 and the barrel 150 becomes.

[0038] As described above, in the second embodiment, the control unit 30 decreases the distance between the screw 140 and the barrel 150 as the modeling speed increases. In this way, decreasing the distance between the screw 140 and the barrel 150 increases the pressure of the modeling material generated in the plasticizing unit 110, and increases the discharge speed of the modeling material from the nozzle 104. This allows a three-dimensional object to be modeled at high speed.

[0039] Although it is possible to speed up the molding process by increasing the rotation speed of the screw 140, there is a limit to the rotation speed of the screw 140, so it is possible to speed up the molding process by reducing the distance between the screw 140 and the barrel 150.

[0040] C. Third embodiment: The configuration of the three-dimensional printing apparatus 10 in the third embodiment is the same as that in the first embodiment. In the third embodiment, in step S20 of the three-dimensional printing process shown in FIG. 6, the control unit 30 acquires a condition related to the viscosity of the printing material as a condition related to printing. For example, the control unit 30 stores a table showing the properties of each material shown in FIG. 5 in a storage device, and receives a selection of the type of printing material to be used for printing from the printing data or from the user. Then, the control unit 30 acquires the viscosity of the printing material corresponding to the selected type from the table stored in the storage device.

[0041] In step S30, when the condition regarding the viscosity of the modeling material is the first condition, the control unit 30 sets the distance between the screw 140 and the barrel 150 to a first distance. When the condition regarding the viscosity of the modeling material is the second condition, the control unit 30 sets the distance between the screw 140 and the barrel 150 to a second distance that is greater than the first distance. In this embodiment, the second condition is a condition in which the viscosity of the modeling material is higher than that of the first condition. Therefore, in this embodiment, the higher the viscosity of the modeling material, the greater the distance between the screw 140 and the barrel 150. In the example materials shown in FIG. 5, ABS containing carbon filler has the smallest MFR value and therefore the highest viscosity, and PVA has the largest MFR value and therefore the lowest viscosity. Therefore, when ABS containing carbon filler is used as the modeling material, the distance between the screw 140 and the barrel 150 is greatest, and when PVA is used as the modeling material, the distance between the screw 140 and the barrel 150 is smallest.

[0042] As described above, in the third embodiment, the control unit 30 increases the distance between the screw 140 and the barrel 150 as the viscosity of the modeling material increases. When the distance between the screw 140 and the barrel 150 is small and a high-viscosity modeling material is used, the modeling material may adhere to the screw 140 and the barrel 150, resulting in poor fluidity. In contrast, increasing the distance between the screw 140 and the barrel 150 can increase the fluidity of the modeling material even when the viscosity of the modeling material is high, thereby enabling stable modeling. Furthermore, increasing the distance between the screw 140 and the barrel 150 can prevent the rotation of the drive motor 112 from being hindered by a high-viscosity modeling material, thereby preventing the motor from becoming overloaded.

[0043] D. Fourth embodiment: The configuration of the 3D printing apparatus 10 in the fourth embodiment is the same as that in the first embodiment. In the fourth embodiment, in step S20 of the 3D printing process shown in FIG. 6, the control unit 30 acquires a condition related to the adhesiveness of the printing material as a condition related to printing. For example, the control unit 30 stores a table showing the properties of each material shown in FIG. 5 in a storage device, and receives a selection of the type of printing material to be used for printing from the printing data or from the user. Then, the control unit 30 acquires the adhesiveness of the printing material corresponding to the selected type from the table stored in the storage device.

[0044] In step S30, when the condition regarding the adhesiveness of the modeling material is the first condition, the control unit 30 sets the distance between the screw 140 and the barrel 150 to a first distance. When the condition regarding the adhesiveness of the modeling material is the second condition, the control unit 30 sets the distance between the screw 140 and the barrel 150 to a second distance that is greater than the first distance. In this embodiment, the second condition is a condition under which the adhesiveness of the modeling material is higher than that under the first condition. Therefore, in this embodiment, the higher the adhesiveness of the modeling material, the greater the distance between the screw 140 and the barrel 150. In the example of materials shown in FIG. 5, the SP value of PVA is closer to the SP value of water (23.4) than the SP value of ABS, and therefore PVA has higher adhesiveness. Therefore, when PVA is used as the modeling material, the distance between the screw 140 and the barrel 150 is greater than when ABS is used.

[0045] As described above, in the fourth embodiment, the control unit 30 increases the distance between the screw 140 and the barrel 150 as the adhesiveness of the modeling material increases. When the distance between the screw 140 and the barrel 150 is small and a highly adhesive modeling material is used, the modeling material may adhere to the screw 140 and the barrel 150, resulting in poor fluidity. In contrast, increasing the distance between the screw 140 and the barrel 150 can increase the fluidity of the modeling material even when the adhesiveness of the modeling material is high, thereby enabling stable modeling. Furthermore, increasing the distance between the screw 140 and the barrel 150 can prevent the rotation of the drive motor 112 from being hindered by a highly adhesive modeling material, thereby preventing the drive motor 112 from becoming overloaded.

[0046] E. Fifth embodiment: The configuration of the 3D printing apparatus 10 in the fifth embodiment is the same as that in the first embodiment. In the fifth embodiment, in step S20 of the 3D printing process shown in FIG. 6, the control unit 30 acquires a condition related to the thermal conductivity of the printing material as a printing-related condition. For example, the control unit 30 stores a table showing the properties of each material shown in FIG. 5 in a storage device, and receives a selection of the type of printing material to be used for printing from the printing data or from the user. Then, the control unit 30 acquires the thermal conductivity of the printing material corresponding to the selected type from the table stored in the storage device.

[0047] In step S30, when the condition regarding the thermal conductivity of the modeling material is the first condition, the control unit 30 sets the distance between the screw 140 and the barrel 150 to a first distance. When the condition regarding the thermal conductivity of the modeling material is the second condition, the control unit 30 sets the distance between the screw 140 and the barrel 150 to a second distance that is greater than the first distance. In this embodiment, the second condition is a condition in which the thermal conductivity of the modeling material is higher than that of the first condition. Therefore, in this embodiment, the higher the thermal conductivity of the modeling material, the greater the distance between the screw 140 and the barrel 150. Among the examples of materials shown in FIG. 5, PVA has the highest thermal conductivity, and ABS has the lowest thermal conductivity. Therefore, when PVA is used as the modeling material, the distance between the screw 140 and the barrel 150 is greatest, and when ABS is used, the distance between the screw 140 and the barrel 150 is smallest.

[0048] As described above, in the fifth embodiment, the control unit 30 increases the distance between the screw 140 and the barrel 150 as the thermal conductivity of the modeling material increases. To improve the material transportability during plasticization, the screw 140 is preferably kept at a low temperature. If the screw 140 is too hot, the material plasticizes prematurely, reducing the transportability of the material due to the rotation of the screw 140. Therefore, as in the present embodiment, increasing the distance between the screw 140 and the barrel 150 when the material has high thermal conductivity can prevent heat from being transferred from the barrel 150 to the screw 140 through the material, thereby preventing the screw 140 from becoming too hot. Therefore, increasing the distance between the screw 140 and the barrel 150 can stably generate modeling material even when the material has high thermal conductivity.

[0049] F. Sixth embodiment: The configuration of the three-dimensional printing apparatus 10 in the sixth embodiment is the same as that in the first embodiment. In the sixth embodiment, in step S20 of the three-dimensional printing process shown in FIG. 6, the control unit 30 acquires a condition related to the density of the printing material as a condition related to printing. For example, the control unit 30 stores a table showing the properties of each material shown in FIG. 5 in a storage device, and receives a selection of the type of printing material to be used for printing from the printing data or from the user. Then, the control unit 30 acquires the density of the printing material corresponding to the selected type from the table stored in the storage device.

[0050] In step S30, when the condition related to the density of the molding material is the first condition, the control unit 30 sets the distance between the screw 140 and the barrel 150 to a first distance. When the condition related to the density of the molding material is the second condition, the control unit 30 sets the distance between the screw 140 and the barrel 150 to a second distance that is greater than the first distance. In this embodiment, the second condition is a condition in which the density of the molding material is lower than that of the first condition. Therefore, in this embodiment, the lower the density of the molding material, the greater the distance between the screw 140 and the barrel 150. Among the examples of materials shown in FIG. 5, PP containing acrylic has the lowest density, and PEEK and PVA have the highest densities. Therefore, when PP containing acrylic is used as the molding material, the distance between the screw 140 and the barrel 150 is greatest, and when PEEK or PVA is used, the distance between the screw 140 and the barrel 150 is smallest.

[0051] As described above, in the sixth embodiment, the control unit 30 increases the distance between the screw 140 and the barrel 150 as the density of the modeling material decreases. Bioplastic materials, such as PP containing acrylic, have low density and are difficult to melt. Therefore, the lower the density of the material, the greater the distance between the screw 140 and the barrel 150 is increased, and the material conveying speed between the screw 140 and the barrel 150 is slowed. This increases the time for heat to be transferred from the barrel 150 to the material, thereby promoting plasticization of the material. Therefore, by increasing the distance between the screw 140 and the barrel 150, modeling material can be stably produced even when a material with low density and low melting ability is used.

[0052] G. Seventh embodiment: The configuration of the three-dimensional printing apparatus 10 in the seventh embodiment is the same as that in the first embodiment. In the seventh embodiment, in step S20 of the three-dimensional printing process shown in FIG. 6, the control unit 30 acquires a condition related to the specific heat of the printing material as a condition related to printing. For example, the control unit 30 stores a table showing the properties of each material shown in FIG. 5 in a storage device, and receives a selection of the type of printing material to be used for printing from the printing data or from the user. Then, the control unit 30 acquires the specific heat of the printing material corresponding to the selected type from the table stored in the storage device.

[0053] In step S30, when the condition regarding the specific heat of the building material is the first condition, the control unit 30 sets the distance between the screw 140 and the barrel 150 to a first distance. When the condition regarding the specific heat of the building material is the second condition, the control unit 30 sets the distance between the screw 140 and the barrel 150 to a second distance that is greater than the first distance. In this embodiment, the second condition is a condition in which the specific heat of the building material is smaller than that of the first condition. Therefore, in this embodiment, the smaller the specific heat of the building material, the greater the distance between the screw 140 and the barrel 150. Among the examples of materials shown in FIG. 5, PET has the smallest specific heat, and ABS has the largest specific heat. Therefore, when PET is used as the building material, the distance between the screw 140 and the barrel 150 is greatest, and when ABS is used, the distance between the screw 140 and the barrel 150 is smallest.

[0054] As described above, in the seventh embodiment, the control unit 30 increases the distance between the screw 140 and the barrel 150 as the specific heat of the modeling material decreases. When plasticizing the material, it is preferable that the shape of the material be maintained to some extent between the screw 140 and the barrel 150 to ensure good material transport. However, if the specific heat of the material is low, the material is more likely to melt, which may hinder the transport of the material between the screw 140 and the barrel 150. Therefore, if the specific heat of the material is low or high, increasing the distance between the screw 140 and the barrel 150 makes it easier to maintain the shape of the material, thereby improving the transportability of the material and enabling the stable production of a three-dimensional object.

[0055] H. Eighth embodiment: The configuration of the three-dimensional printing apparatus 10 in the eighth embodiment is the same as that in the first embodiment. In the eighth embodiment, in step S20 of the three-dimensional printing process shown in FIG. 6, the control unit 30 acquires a condition related to the size of the material as a condition related to printing. For example, the control unit 30 stores a table indicating the properties of each material in a storage device, and receives a selection of the type of printing material to be used for printing from the printing data or from the user. Then, the control unit 30 acquires the size of the printing material corresponding to the selected type from the table stored in the storage device.

[0056] In step S30, when the condition regarding the size of the material is a first condition, the control unit 30 sets the distance between the screw 140 and the barrel 150 to a first distance. When the condition regarding the size of the material is a second condition, the control unit 30 sets the distance between the screw 140 and the barrel 150 to a second distance that is greater than the first distance. In this embodiment, the second condition is a condition in which the size of the material is greater than the first condition. Therefore, in this embodiment, the larger the size of the material, the greater the distance between the screw 140 and the barrel 150.

[0057] As described above, in the seventh embodiment, the control unit 30 increases the distance between the screw 140 and the barrel 150 as the size of the material increases. By doing so, when a large-sized material is used, the material can be more easily introduced from the material supply path 196 to between the screw 140 and the barrel 150 through the material inlet 144. Therefore, by increasing the distance between the screw 140 and the barrel 150, it is possible to stably generate a modeling material even when a large-sized material is used.

[0058] I. Other forms: The present disclosure is not limited to the above-described embodiments and can be realized in various configurations without departing from the spirit thereof. For example, the technical features of the embodiments corresponding to the technical features in each aspect described below can be appropriately replaced or combined to solve some or all of the above-described problems or achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be appropriately deleted.

[0059] (1) According to a first aspect of the present disclosure, there is provided a three-dimensional modeling apparatus, the three-dimensional modeling apparatus comprising: a plasticizing unit that plasticizes a material to generate a modeling material; a nozzle that discharges the modeling material toward a stage; and a control unit that controls the formation of a three-dimensional object by discharging the modeling material from the nozzle, the plasticizing unit comprising: a drive motor; a screw that is rotated by the drive motor and has a groove-forming surface with a ridge formed from a center portion to an outer periphery; a barrel that faces the groove-forming surface and has a communication hole that communicates with the nozzle at a position facing the center portion of the groove-forming surface; and a pressure vessel that is provided between the screw and the barrel. The system has a heating unit that heats the supplied material and a position change mechanism that changes the relative position of the screw and the barrel, and when the molding condition is a first condition, the control unit uses the position change mechanism to set the distance between the screw and the barrel to a first distance and cause the plasticization unit to generate the molding material, and when the condition is a second condition, the control unit uses the position change mechanism to set the distance between the screw and the barrel to a second distance and cause the plasticization unit to generate the molding material, the second distance being greater than the first distance. According to this configuration, the distance between the screw and the barrel can be changed depending on the conditions related to the modeling, so that it is possible to improve at least one of high precision and high speed in the modeling of a three-dimensional object.

[0060] (2) In the above-described embodiment, the modeling conditions may be conditions related to modeling accuracy, and the second condition may be a condition related to modeling accuracy that is higher than the first condition. According to this embodiment, when improving the modeling accuracy, the pressure of the modeling material can be reduced by increasing the distance between the screw and the barrel. This reduces the discharge speed of the modeling material, enabling a three-dimensional object to be modeled with high accuracy.

[0061] (3) In the above-described embodiment, the conditions related to the modeling may be conditions related to the modeling speed, and the first condition may be a condition related to the modeling speed that is faster than the second condition. According to this embodiment, when the modeling speed is increased, the pressure of the modeling material can be increased by reducing the distance between the screw and the barrel. This increases the discharge speed of the modeling material, enabling a three-dimensional object to be modeled at high speed.

[0062] (4) In the above embodiment, the modeling condition may be a condition related to the viscosity of the modeling material, and the second condition may be a condition related to a viscosity of the modeling material higher than that of the first condition. According to this embodiment, even when a modeling material with a high viscosity is used, the fluidity of the modeling material in the plasticizing section can be improved by increasing the distance between the screw and the barrel, and a three-dimensional object can be stably modeled.

[0063] (5) In the above embodiment, the modeling condition may be a condition related to the adhesiveness of the modeling material, and the second condition may be a condition related to the adhesiveness of the modeling material that is higher than that of the first condition. According to this embodiment, even when a modeling material with high adhesiveness is used, the fluidity of the modeling material in the plasticizing section can be improved by increasing the distance between the screw and the barrel, and a three-dimensional object can be stably modeled.

[0064] (6) In the above embodiment, the modeling condition may be a condition related to the thermal conductivity of the modeling material, and the second condition may be a condition related to the thermal conductivity of the modeling material that is higher than that of the first condition. According to this embodiment, even when a modeling material with high thermal conductivity is used, increasing the distance between the screw and the barrel can suppress heat transfer from the barrel to the screw, thereby enabling stable modeling of a three-dimensional object.

[0065] (7) In the above-described embodiment, the modeling condition may be a condition related to the density of the modeling material, and the second condition may be a condition related to the density of the modeling material lower than the first condition. According to this embodiment, when the density of the modeling material is low, the distance between the screw and the barrel may be increased to reduce the conveying speed of the modeling material, thereby extending the heating time of the modeling material and making it easier to plasticize the low-density modeling material. Therefore, even when using a modeling material that is low in density and difficult to plasticize, a three-dimensional object can be stably manufactured.

[0066] (8) In the above embodiment, the modeling condition may be a condition related to the specific heat of the modeling material, and the second condition may be a condition related to the specific heat of the modeling material that is smaller than the specific heat of the modeling material that is the first condition. According to this embodiment, even when a modeling material with a low specific heat and high melting ability is used, increasing the distance between the screw and the barrel makes it easier to maintain the shape of the modeling material, and the modeling material can be transported smoothly between the screw and the barrel. Therefore, a three-dimensional object can be stably modeled.

[0067] (9) In the above embodiment, the modeling condition may be a condition related to the size of the material, and the second condition may be a condition related to the size of the material larger than the first condition. According to this embodiment, even when a large modeling material is used, increasing the distance between the screw and the barrel makes it easier to introduce the material between the screw and the barrel. Therefore, a three-dimensional object can be stably modeled.

[0068] (10) According to a second aspect of the present disclosure, there is provided a method for manufacturing a three-dimensional object. This manufacturing method includes a generating step of generating a modeling material by plasticizing a material using a plasticizing unit, and a modeling step of discharging the modeling material from a nozzle to form a three-dimensional object, wherein the plasticizing unit includes a drive motor, a screw that is rotated by the drive motor and has a groove-forming surface with a ridge formed from a center portion to an outer periphery, a barrel that faces the groove-forming surface and has a communication hole that communicates with the nozzle at a position facing the center portion of the groove-forming surface, and a heating element that heats the material supplied between the screw and the barrel. The device has a heating section and a position change mechanism that changes the relative position of the screw and the barrel, and in the generation process, when the condition related to the molding is a first condition, the position change mechanism sets the distance between the screw and the barrel to a first distance and causes the plasticization section to generate the molding material, and when the condition is a second condition, the position change mechanism sets the distance between the screw and the barrel to a second distance and causes the plasticization section to generate the molding material, the second distance being greater than the first distance. [Explanation of symbols]

[0069] 10...three-dimensional modeling apparatus, 20...chamber, 21...modeling space, 30...control unit, 100...discharge unit, 102...material storage unit, 104...nozzle, 110...plasticization unit, 112...drive motor, 114...reduction gear, 115...output shaft, 116...screw shaft, 117...flange portion, 120...position change mechanism, 140...screw, 141...connection surface, 142...groove portion, 143...ridge portion, 144...material inlet, 146...center portion, 148...groove forming surface, 150...barrel, 152...opposing surface, 154...guide groove, 156...communicating hole, 158...heating portion, 170...bearing, 180...connecting portion, 181...connecting bolt, 196...material supply path, 200...casing, 201...first casing, 202...second casing, 210...moving mechanism portion, 220...stage

Claims

1. a plasticizing unit that plasticizes the material to generate a modeling material; a nozzle that ejects the modeling material toward a stage; a control unit that controls the formation of a three-dimensional object by discharging the modeling material from the nozzle; and Equipped with The plasticizing section includes: A drive motor; a screw that is rotated by the drive motor and has a groove-forming surface on which a ridge portion is formed from a center portion toward an outer periphery; a barrel facing the groove forming surface and having a communication hole communicating with the nozzle at a position facing the central portion of the groove forming surface; a heating section that heats the material supplied between the screw and the barrel; a position changing mechanism for changing the relative position of the screw and the barrel; and The control unit When the condition for modeling is a first condition, the position changing mechanism sets the distance between the screw and the barrel to a first distance, and causes the plasticizing section to generate the modeling material; When the condition is a second condition, the position changing mechanism changes the distance between the screw and the barrel to a second distance, and the plasticizing section generates the modeling material; the second distance is greater than the first distance; A three-dimensional modeling apparatus characterized by:

2. The three-dimensional modeling apparatus according to claim 1, the conditions related to the shaping are conditions related to shaping accuracy, The second condition has a higher modeling accuracy than the first condition. A three-dimensional modeling apparatus characterized by:

3. The three-dimensional modeling apparatus according to claim 1, the condition related to the modeling is a condition related to a modeling speed, The first condition has a faster modeling speed than the second condition. A three-dimensional modeling apparatus characterized by:

4. The three-dimensional modeling apparatus according to claim 1, the conditions related to the modeling are conditions related to the viscosity of the modeling material, The second condition has a higher viscosity of the modeling material than the first condition. A three-dimensional modeling apparatus characterized by:

5. The three-dimensional modeling apparatus according to claim 1, the modeling conditions are conditions related to adhesiveness of the modeling material, The second condition is higher in adhesiveness of the modeling material than the first condition. A three-dimensional modeling apparatus characterized by:

6. The three-dimensional modeling apparatus according to claim 1, the condition related to the modeling is a condition related to the thermal conductivity of the modeling material, The second condition has a higher thermal conductivity of the building material than the first condition. A three-dimensional modeling apparatus characterized by:

7. The three-dimensional modeling apparatus according to claim 1, the condition related to the modeling is a condition related to the density of the modeling material, The second condition has a lower density of the building material than the first condition. A three-dimensional modeling apparatus characterized by:

8. The three-dimensional modeling apparatus according to claim 1, the conditions related to the modeling are conditions related to the specific heat of the modeling material, The second condition is that the specific heat of the building material is smaller than that of the first condition. A three-dimensional modeling apparatus characterized by:

9. The three-dimensional modeling apparatus according to claim 1, the conditions for shaping are conditions for the size of the material, The second condition is that the size of the material is larger than that of the first condition. A three-dimensional modeling apparatus characterized by:

10. a generating step of generating a modeling material by plasticizing the material with a plasticizing unit; a modeling step of discharging the modeling material from a nozzle to form a three-dimensional object; Equipped with The plasticizing section includes: A drive motor; a screw that is rotated by the drive motor and has a groove-forming surface on which a ridge portion is formed from a center portion toward an outer periphery; a barrel facing the groove forming surface and having a communication hole communicating with the nozzle at a position facing the central portion of the groove forming surface; a heating section that heats the material supplied between the screw and the barrel; a position changing mechanism for changing the relative position of the screw and the barrel; and In the producing step, When the condition for modeling is a first condition, the position changing mechanism sets the distance between the screw and the barrel to a first distance, and causes the plasticizing section to generate the modeling material; When the condition is a second condition, the position changing mechanism changes the distance between the screw and the barrel to a second distance, and the plasticizing section generates the modeling material; the second distance is greater than the first distance; A method for manufacturing a three-dimensional object, comprising:

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