Method for manufacturing three-dimensional object and three-dimensional printing device

Abstract

To provide a technology capable of molding a three-dimensional molded object having desired characteristics in an easy method.SOLUTION: A manufacturing method of a three-dimensional molded object includes: a first step of receiving a selection of a molding mode of the three-dimensional molded object; a second step of forming a plasticizing material by plasticizing at least part of a material using a plasticizing section including a flat screw having a groove forming face in which a groove is formed and rotating, and a barrel having an opposite face that faces the groove forming face and in which a communication hole that communicates with a nozzle is formed; and a third step of discharging the plasticizing material from the nozzle toward a stage. In the second step, the plasticizing section is controlled according to the molding mode received in the first step.SELECTED DRAWING: Figure 5

Description

[Technical Field]

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

[0002] Regarding a three-dimensional modeling device, Patent Document 1 discloses that a material is plasticized by a plasticizing section having a flat screw to convert it into a molten material, and the molten material is ejected to form a three-dimensional object. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-187777 Summary of the Invention [Problem to be solved by the invention]

[0004] In the past, to obtain a three-dimensional object with desired characteristics such as precision, users themselves had to fine-tune the control data of the plasticizing unit and repeatedly make prototypes. Therefore, there was a demand for a technology that can easily produce three-dimensional objects with desired characteristics. [Means for solving the problem]

[0005] According to a first aspect of the present disclosure, there is provided a method for manufacturing a three-dimensionally shaped object. The method includes: a first step of accepting a selection of a modeling mode for the three-dimensionally shaped object; a second step of plasticizing at least a portion of a material to generate a plasticized material using a plasticizing unit including a rotating flat screw having a groove-forming surface with grooves formed thereon and a barrel having an opposing surface facing the groove-forming surface and formed with a communication hole communicating with a nozzle; and a third step of ejecting the plasticized material from the nozzle toward a stage. In the second step, the plasticizing unit is controlled according to the modeling mode accepted in the first step.

[0006] According to a second aspect of the present disclosure, there is provided a three-dimensional modeling apparatus comprising: a plasticizing unit that plasticizes at least a portion of a material to produce the plasticized material, the plasticizing unit including: a nozzle that discharges a plasticized material toward a stage; a rotating flat screw having a groove-forming surface with grooves formed thereon; and a barrel having an opposing surface facing the groove-forming surface and formed with a communication hole that communicates with the nozzle; and a control unit that controls the plasticizing unit to form a three-dimensional object according to a selected modeling mode. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is an explanatory diagram illustrating a schematic configuration of a three-dimensional printing system. [Figure 2] FIG. 2 is a perspective view showing a schematic configuration of a flat screw. [Figure 3] FIG. 2 is a plan view showing a schematic configuration of a barrel. [Figure 4] FIG. 1 is an explanatory diagram schematically illustrating how a three-dimensional object is formed. [Figure 5] 10 is a flowchart of a modeling data generation process. [Figure 6] FIG. 10 is a diagram illustrating an example of a modeling mode. [Figure 7] FIG. 10 is a diagram illustrating an example of layer data. [Figure 8] 10 is a flowchart of a three-dimensional modeling process. DETAILED DESCRIPTION OF THE INVENTION

[0008] A. First embodiment: FIG. 1 is an explanatory diagram showing a schematic configuration of a three-dimensional printing system 10 according to a first embodiment. Arrows indicating mutually orthogonal X, Y, and Z directions are shown in FIG. 1. The X and Y directions are parallel to a horizontal plane, and the Z direction is a vertically upward direction. The arrows indicating the X, Y, and Z directions are also shown in other figures as appropriate so that the illustrated directions correspond to those in FIG. 1. In the following description, when specifying the direction, positive and negative signs are used in combination to indicate the direction indicated by the arrow in each figure, with "+" indicating the direction indicated by the arrow and "-" indicating the opposite direction. Hereinafter, the +Z direction will also be referred to as "up" and the -Z direction as "down."

[0009] The three-dimensional printing system 10 includes a three-dimensional printing device 100 and a control unit 101 that controls the three-dimensional printing device 100. The three-dimensional printing device 100 includes a printing unit 110 that generates and dispenses a plasticized material, a printing stage 210 that serves as a base for the three-dimensional object, and a movement mechanism 230 that controls the dispensing position of the plasticized material. The three-dimensional printing device 100 may be housed in a chamber (not shown).

[0010] Under the control of the control unit 101, the modeling unit 110 melts a solid material to form a paste-like plasticized material, and discharges the melted material onto the stage 210. The modeling unit 110 includes a material supply unit 20, which is a supply source of the material before it is converted into the plasticized material, a plasticizing unit 30, which converts the material into the plasticized material, and a discharge unit 60, which discharges the plasticized material.

[0011] The material supply unit 20 supplies the material for producing the plasticized material to the plasticizing unit 30. The material supply unit 20 is configured, for example, by a hopper that stores the material. The material supply unit 20 has a discharge outlet at its bottom. The discharge outlet is connected to the plasticizing unit 30 via a supply path 22. The material is fed into the material supply unit 20 in the form of pellets, powder, or the like. In this embodiment, pellet-shaped ABS resin material is used.

[0012] The plasticizing unit 30 includes a screw case 31, a drive motor 32, a flat screw 40, a barrel 50, a heating unit 120, and a cooling unit 130. The plasticizing unit 30 plasticizes at least a portion of the material supplied from the material supply unit 20 to produce a fluid, paste-like plasticized material, which is then supplied to the discharge unit 60. "Plasticization" is a concept that includes melting and refers to changing a material from a solid to a fluid state. Specifically, for materials that undergo glass transition, plasticization refers to raising the temperature of the material above the glass transition point. For materials that do not undergo glass transition, plasticization refers to raising the temperature of the material above the melting point.

[0013] 2 is a perspective view showing the schematic configuration of the flat screw 40. The flat screw 40 has a generally cylindrical shape with a height in the axial direction, which is the direction along its central axis RX, that is smaller than its diameter. The flat screw 40 is arranged so that the central axis RX, which is the center of rotation, is parallel to the Z direction. The flat screw 40 is also called a scroll or rotor.

[0014] As shown in FIG. 1, the flat screw 40 is housed in a screw case 31. As shown in FIGS. 1 and 2, the flat screw 40 has a groove forming surface 42 on which a groove 45 is formed. In this embodiment, the groove forming surface 42 is formed by the underside of the flat screw 40. The upper surface side of the flat screw 40 is connected to a drive motor 32, and the flat screw 40 rotates within the screw case 31 by the rotational driving force generated by the drive motor 32. The drive motor 32 is driven under the control of the control unit 101. Note that the flat screw 40 may be driven by the drive motor 32 via a reducer.

[0015] As shown in FIG. 2, spiral grooves 45 are formed on the groove-forming surface 42. The supply passage 22 of the material supply unit 20 described above communicates with the grooves 45 from the side surface of the flat screw 40. The grooves 45 continue to a material inlet 44 formed on the side surface of the flat screw 40. This material inlet 44 is a portion that receives the material supplied via the supply passage 22 of the material supply unit 20. As shown in FIG. 3, in this embodiment, three grooves 45 are formed, separated by ridge portions 46. The number of grooves 45 is not limited to three, and may be one, two, or more. The grooves 45 are not limited to a spiral shape, but may also be a spiral or involute curve shape, or may have a shape that extends in an arc from a center portion 47 to the outer periphery.

[0016] FIG. 3 is a plan view showing a schematic configuration of the barrel 50. As shown in FIG. 1, in this embodiment, the barrel 50 is disposed below the flat screw 40. As shown in FIGS. 1 and 3, the barrel 50 has an opposing surface 52 that faces the groove-forming surface 42 of the flat screw 40. In this embodiment, the opposing surface 52 is formed by the upper surface of the barrel 50. The opposing surface 52 and the groove-forming surface 42 face each other in the Z direction, and a space is formed between the opposing surface 52 and the grooves 45 of the groove-forming surface 42. The barrel 50 has a communication hole 56 on the central axis RX of the flat screw 40 that communicates with a nozzle 61 of a discharge unit 60, which will be described later.

[0017] As shown in Figure 3, a plurality of guide grooves 54 are formed around the communicating hole 56 in the opposing surface 52. One end of each guide groove 54 is connected to the communicating hole 56, and extends in a spiral shape from the communicating hole 56 toward the outer periphery of the opposing surface 52. Each guide groove 54 has the function of guiding the plasticized material to the communicating hole 56. Note that one end of each guide groove 54 does not have to be connected to the communicating hole 56. Furthermore, the barrel 50 does not necessarily have to have any guide grooves 54 formed therein.

[0018] 1 and 3 heats the material supplied between the groove forming surface 42 and the opposing surface 52. The heating section 120 in this embodiment has a first heating section 121 and a second heating section 122.

[0019] In FIG. 3, the positions of the first heating section 121 and the second heating section 122 as viewed in the Z direction are indicated by dashed lines and hatching. The second heating section 122 is disposed closer to the communicating hole 56 than the first heating section 121 as viewed in the Z direction. More specifically, in this embodiment, the first heating section 121 and the second heating section 122 are each formed of a pair of rod-shaped heaters embedded in the barrel 50. The pair of rod-shaped heaters constituting the first heating section 121 and the second heating section 122 are each disposed such that their longitudinal directions are aligned with the Y direction and that they sandwich the communicating hole 56 in the X direction. The first heating section 121 is formed of two rod-shaped heaters closer to the communicating hole 56 as viewed in the Z direction, and the second heating section 122 is formed of two rod-shaped heaters farther from the communicating hole 56 as viewed in the Z direction. The first heating section 121 and the second heating section 122 are configured to be individually controllable by the control section 101. In other embodiments, the first heating section 121 and the second heating section 122 do not have to be configured by rod-shaped heaters, and may be configured by, for example, annular heaters arranged along the opposing surface 52.

[0020] The cooling unit 130 cools the plasticizing unit 30. As shown in Fig. 1, the cooling unit 130 in this embodiment has a refrigerant flow path 131 and a refrigerant circulation device 134.

[0021] As shown in FIG. 3, the refrigerant flow path 131 has an inlet portion 132 and an outlet portion 133. In FIG. 3, the positions of the refrigerant flow path 131, the inlet portion 132, and the outlet portion 133 are indicated by dashed lines when viewed along the Z direction. The refrigerant flow path 131 allows the refrigerant introduced into the refrigerant flow path 131 through the inlet portion 132 to flow toward the outlet portion 133 and discharges the refrigerant from the refrigerant flow path 131 through the outlet portion 133. In this embodiment, the refrigerant flow path 131 is formed inside the barrel 50. In this embodiment, the refrigerant flow path 131 is formed in a substantially annular shape along the circumferential direction of the opposing surface 52 so as to surround the heating unit 120 when viewed along the Z direction. More specifically, the refrigerant flow path 131 in this embodiment is disposed between the second heating unit 122 and the outer edge 57 of the opposing surface 52 when viewed along the Z direction. The refrigerant circulation device 134 shown in FIG. 1 is connected to the inlet portion 132 and the outlet portion 133. The refrigerant circulation device 134 is configured by a chiller that circulates the refrigerant through the refrigerant flow path 131 and maintains the temperature of the refrigerant flowing through the refrigerant flow path 131 by air cooling, water cooling, or the like. The refrigerant circulation device 134 is controlled by the control unit 101. Note that in other embodiments, the refrigerant flow path 131, the inlet portion 132, and the outlet portion 133 may be formed inside the screw case 31, and the refrigerant flow path 131 may be formed inside the screw case 31 along the outer periphery of the flat screw 40.

[0022] The material supplied into the groove 45 of the flat screw 40 is melted in the groove 45, flows along the groove 45 due to the rotation of the flat screw 40, and is guided to the central portion 47 of the flat screw 40 as a plasticized material. The paste-like plasticized material that has flowed into the central portion 47 and exhibits fluidity is supplied to the nozzle 61 via the communicating hole 56. It is not necessary for all types of substances that make up the plasticized material to melt; it is sufficient that at least some of the types of substances that make up the plasticized material melt, thereby converting the plasticized material as a whole into a fluid state.

[0023] The control unit 101 can adjust the amount of plasticizing material supplied to the nozzle 61 through the communication hole 56 by adjusting the screw rotation speed, which represents the number of rotations per unit time of the flat screw 40, and the set temperatures of the heating unit 120 and the cooling unit 130. This allows the amount of plasticizing material discharged from the nozzle 61 to be adjusted. For example, by increasing the screw rotation speed, the control unit 101 can guide more material to the central unit 47 per unit time, thereby increasing the discharge amount. Furthermore, the control unit 101 can increase the set temperature of the heating unit 120 or the cooling unit 130 to increase the temperature of the plasticizing unit 30, thereby further promoting the plasticization of the material in the plasticizing unit 30, thereby increasing the discharge amount.

[0024] In this embodiment, when the plasticizer 30 plasticizes the material to produce the plasticized material, the control unit 101 controls the first heating unit 121, the second heating unit 122, and the cooling unit 130 to generate a temperature gradient in the plasticizer 30. The temperature gradient in the plasticizer 30 refers to a temperature gradient in the plasticizer 30 that increases from the outer edge of the facing surface 52 toward the communicating hole 56 when viewed along the Z direction. By generating a temperature gradient in the plasticizer 30, the material supplied between the groove forming surface 42 and the facing surface 52 is heated to a higher temperature toward the central portion 47. Therefore, the fluidity of the material near the material inlet 44 is likely to be maintained lower than the fluidity of the material near the central portion 47. This makes it easier to obtain a conveying force that conveys the material from the material inlet 44 toward the central portion 47, thereby stabilizing the amount of plasticized material delivered from the plasticizer 30 to the nozzle 61. Furthermore, for example, by increasing the set temperature of the second heating section 122 and increasing the temperature gradient in the plasticizing section 30, the material conveying force in the plasticizing section 30 can be increased.

[0025] The discharge unit 60 includes a nozzle 61 that discharges the plasticized material, a supply flow path 65 provided between the flat screw 40 and a nozzle opening 62, a discharge control unit 70 that opens and closes the supply flow path 65, and a suction and discharge unit 75 that sucks in and temporarily stores the plasticized material. The nozzle 61 is connected to the communication hole 56 of the barrel 50 through the supply flow path 65. The nozzle 61 discharges the plasticized material produced in the plasticizing unit 30 from the nozzle opening 62 at its tip toward the stage 210. A heater may be arranged around the nozzle 61 to suppress a drop in temperature of the plasticized material discharged onto the stage 210.

[0026] The discharge control unit 70 is provided in the supply flow path 65 that communicates with the nozzle opening 62, and rotates within the supply flow path 65 to change the aperture of the supply flow path 65. In this embodiment, the discharge control unit 70 is configured as a butterfly valve. The discharge control unit 70 is driven by a first drive unit 74 under the control of the control unit 101. The first drive unit 74 is configured, for example, by a stepping motor. The control unit 101 controls the rotation angle of the butterfly valve using the first drive unit 74 to switch the aperture of the supply flow path 65 between a state where the aperture is 0 and a state where the aperture is greater than 0. In this way, the control unit 101 controls the on / off of the discharge of the plasticized material through the nozzle 61.

[0027] The suction and discharge unit 75 is connected between the discharge control unit 70 and the nozzle opening 62 in the supply flow path 65. The suction and discharge unit 75 performs a suction operation to suck the plasticized material in the supply flow path 65 and a discharge operation to push the sucked plasticized material toward the nozzle opening 62. In this embodiment, the suction and discharge unit 75 is configured with a plunger. In the suction operation, the suction and discharge unit 75 moves the plunger back in a direction away from the supply flow path 65, and in the discharge operation, moves the plunger forward in a direction toward the supply flow path 65. The suction and discharge unit 75 is driven by a second drive unit 76 under the control of the control unit 101. The second drive unit 76 is configured with, for example, a stepping motor or a rack-and-pinion mechanism that converts the rotational force of the stepping motor into translational motion of the plunger.

[0028] In this embodiment, the control unit 101 suppresses the tailing phenomenon, in which the plasticized material drips like strings from the nozzle opening 62, by executing a suction operation by the suction and discharge unit 75 when stopping the delivery of the plasticized material from the nozzle 61. In this case, the control unit 101 can more effectively suppress the tailing phenomenon by executing a suction operation after setting the opening degree of the supply flow path 65 to 0 by the discharge control unit 70. Furthermore, the suction and discharge unit 75 performs a discharge operation by the suction and discharge unit 75 when starting or resuming the delivery of the plasticized material from the nozzle 61, thereby improving the responsiveness of the delivery of the plasticized material from the nozzle 61. In this case, the control unit 101 can further improve the responsiveness of the delivery of the plasticized material by executing a suction operation before setting the opening degree of the supply flow path 65 to greater than 0 by the discharge control unit 70. Note that in other embodiments, the control unit 101 may stop the delivery of the plasticized material and start or resume the delivery of the plasticized material by, for example, controlling either the discharge control unit 70 or the suction and discharge unit 75.

[0029] Hereinafter, the flow paths provided in the three-dimensional modeling apparatus 100 through which the plasticized material flows may be collectively referred to as the flow path 69. In this embodiment, the flow path 69 is configured by the communication hole 56 and the supply flow path 65 described above.

[0030] In this embodiment, the flow path 69 is provided with a pressure sensor 140 that detects the pressure inside the flow path 69. The pressure sensor 140 in this embodiment is configured as a diaphragm-type pressure sensor. The pressure sensor 140 is connected upstream of the discharge control unit 70 in the supply flow path 65, and detects the pressure of the plasticized material upstream of the discharge control unit 70 in the supply flow path 65. In other embodiments, the pressure sensor 140 may be configured as, for example, a piezoelectric pressure sensor. Furthermore, the pressure sensor 140 may be connected to, for example, the communication hole 56, and detect the pressure inside the communication hole 56.

[0031] The stage 210 is disposed at a position facing the nozzle opening 62 of the nozzle 61. In the first embodiment, the printing surface 211 of the stage 210 facing the nozzle opening 62 of the nozzle 61 is disposed so as to be parallel to the X and Y directions, i.e., the horizontal direction. In the three-dimensional printing process described below, the three-dimensional printing device 100 prints a three-dimensional object by discharging a plasticized material from the discharging unit 60 toward the printing surface 211 of the stage 210 and stacking layers. The stage 210 may be provided with a heater to prevent the plasticized material discharged onto the stage 210 from cooling rapidly.

[0032] The movement mechanism 230 changes the relative position between the stage 210 and the nozzle 61. In this embodiment, the position of the nozzle 61 is fixed, and the movement mechanism 230 moves the stage 210. The movement mechanism 230 is configured by a three-axis positioner that moves the stage 210 in three axial directions, that is, the X, Y, and Z directions, using the driving forces of three motors. The movement mechanism 230 changes the relative positional relationship between the nozzle 61 and the stage 210 under the control of the control unit 101. In this specification, unless otherwise specified, movement of the nozzle 61 means moving the nozzle 61 and the discharge unit 60 relative to the stage 210. In addition, hereinafter, the movement speed of the nozzle 61 relative to the stage 210 may also be simply referred to as the movement speed of the nozzle 61.

[0033] In other embodiments, instead of a configuration in which the moving mechanism 230 moves the stage 210, a configuration in which the moving mechanism 230 moves the nozzle 61 relative to the stage 210 while the position of the stage 210 is fixed may be employed. Alternatively, a configuration in which the moving mechanism 230 moves the stage 210 in the Z direction and moves the nozzle 61 in the X and Y directions, or a configuration in which the moving mechanism 230 moves the stage 210 in the X and Y directions and moves the nozzle 61 in the Z direction may be employed. Even with these configurations, the relative positional relationship between the nozzle 61 and the stage 210 can be changed.

[0034] The control unit 101 is a control device that controls the overall operation of the 3D printing apparatus 100. The control unit 101 is configured by a computer having one or more processors, a storage device, and an input / output interface that inputs and outputs signals to and from the outside. A display unit 105 configured by a liquid crystal display, an organic EL display, or the like is connected to the control unit 101. The control unit 101 fulfills the functions of a reception unit 102, a printing data generation unit 103, and a printing processing unit 104 by the processor executing programs and instructions loaded onto the storage device. Instead of being configured by a computer, the control unit 101 may be realized by a configuration combining multiple circuits for realizing at least some of the functions. The control unit 101 is also called an information processing device.

[0035] The reception unit 102 receives a selection of a modeling mode for a three-dimensional object from a user via an input device such as a mouse or keyboard (not shown). The modeling mode includes at least one of a mode related to the accuracy of the three-dimensional object and a mode related to the modeling time for the three-dimensional object. The modeling modes will be described in detail later.

[0036] The modeling data generation unit 103 generates modeling data for modeling a three-dimensional object based on the modeling mode accepted by the acceptance unit 102. The modeling data includes path information indicating the movement path of the discharge unit 60, discharge amount information indicating the amount of plasticizing material dispensed on each movement path, and control information for controlling the discharge unit 60 and the plasticizing unit 30. The movement path of the discharge unit 60 is the path along which the nozzle 61 moves along the modeling surface 211 of the stage 210 while discharging the plasticizing material. In this embodiment, the modeling data is composed of outer shell modeling data and interior modeling data. The outer shell modeling data and interior modeling data each include the above-mentioned discharge amount information, discharge amount information, and control information. Details of the outer shell modeling data and interior modeling data will be described later.

[0037] The path information is composed of multiple partial paths. Each partial path is a linear path represented by a start point and an end point. Discharge amount information is individually associated with each partial path. In this embodiment, the discharge amount represented by the discharge amount information is the amount of plasticized material discharged per unit time along that partial path. Note that in other embodiments, the total amount of plasticized material discharged along the entire partial path may be associated with each partial path as discharge amount information.

[0038] The modeling processing unit 104 controls the modeling unit 110, which includes the plasticizing unit 30 and the discharging unit 60, and the movement mechanism 230, based on the modeling data generated by the modeling data generation unit 103, to model a three-dimensional object on the stage 210. When modeling the three-dimensional object, the modeling processing unit 104 moves the discharging unit 60 and discharges the plasticizing material based on path information and discharge amount information included in the modeling data, and controls the plasticizing unit 30 based on the control information.

[0039] FIG. 4 is an explanatory diagram schematically illustrating how a three-dimensional object is formed in the three-dimensional printing apparatus 100. As described above, in the three-dimensional printing apparatus 100, in the plasticizing unit 30, a solid material supplied to the groove 45 of the rotating flat screw 40 is melted to generate a plasticized material MM. The control unit 101 discharges the plasticized material MM from the nozzle 61 in a direction along the printing surface 211 of the stage 210 while changing the position of the nozzle 61 relative to the stage 210, while maintaining the distance between the printing surface 211 of the stage 210 and the nozzle 61. The plasticized material MM discharged from the nozzle 61 is continuously deposited in the direction of movement of the nozzle 61. By scanning the nozzle 61 in this manner, a linear portion LP, which is a printing portion extending linearly along the scanning path of the nozzle 61, is formed.

[0040] The control unit 101 forms layers ML by repeating the above-described scanning by the nozzle 61. After forming one layer ML, the control unit 101 moves the position of the nozzle 61 relative to the stage 210 in the Z direction. Then, a three-dimensional object is formed by stacking further layers ML on the layers ML that have been formed so far.

[0041] When stacking layers of plasticized material, the control unit 101 discharges the plasticized material from the nozzle 61 while maintaining the distance between the nozzle 61 and the discharge target. The discharge target is the modeling surface 211 when discharging the plasticized material onto the modeling surface 211, and is the upper surface of the plasticized material that has already been discharged when discharging the plasticized material onto plasticized material that has already been discharged. The distance between the nozzle 61 and the discharge target is sometimes referred to as the gap Gp.

[0042] The width of the linear region LP is sometimes referred to as the line width, and the height is sometimes referred to as the layer pitch. In the example of FIG. 4, the line width corresponds to the dimension of the linear region LP in the Y direction, and the layer pitch corresponds to the dimension of the linear region LP in the Z direction. The line width and layer pitch are determined by the size of the gap Gp and the amount of plasticized material dispensed from the nozzle 61 per unit movement distance. For example, when the gap Gp is ​​small, the plasticized material dispensed from the nozzle 61 is pressed more firmly against the dispense target by the nozzle 61 than when the gap Gp is ​​large, resulting in a smaller layer pitch and a larger line width. The amount of plasticized material dispensed from the nozzle 61 per unit movement distance is determined, for example, by the movement speed of the nozzle 61 and the amount of plasticized material dispensed from the nozzle 61 per unit time. The amount of plasticized material dispensed from the nozzle 61 per unit time is determined, for example, by the diameter of the nozzle opening 62 and the flow rate of the plasticized material flowing through the flow path 69.

[0043] In this embodiment, when forming a three-dimensional object, the control unit 101 changes the screw rotation speed in accordance with the movement speed of the nozzle 61. This makes it possible to achieve control such that the line width of the discharged plasticized material is kept approximately constant, even if, for example, the movement speed of the nozzle 61, which moves while discharging the plasticized material, is changed midway through its movement.

[0044] Furthermore, in this embodiment, when the nozzle 61 changes direction by 60° or more while discharging the plasticized material, the control unit 101 slows the movement speed of the nozzle 61 compared to the normal speed when the nozzle 61 moves straight or when the nozzle 61 moves while changing direction by less than 60°. More specifically, the control unit 101 gradually slows the movement speed of the nozzle 61 until the nozzle 61 approaches the direction change point, and gradually increases the movement speed of the nozzle 61 as the nozzle 61 leaves the direction change point, returning it to the normal speed. The control unit 101 then reduces the screw rotation speed in response to the decrease in the movement speed of the nozzle 61, and increases the screw rotation speed in response to the increase in the movement speed of the nozzle 61. Note that the control unit 101 also slows the movement speed of the nozzle 61 compared to the normal speed, for example, when stopping the movement of the nozzle 61 and discharging the plasticized material, or when starting or resuming the movement of the nozzle 61 and discharging the plasticized material.

[0045] In this embodiment, when forming a three-dimensional object, the control unit 101 performs feedback control of the plasticizing unit 30 so that the detection value of the pressure sensor 140 falls within a predetermined allowable range. More specifically, the control unit 101 controls the screw rotation speed so that the detection value of the pressure sensor 140 falls within the allowable range. More specifically, when discharging the plasticizing material, the control unit 101 adjusts the screw rotation speed so that the detection value falls within the allowable range by decreasing the screw rotation speed when the detection value of the pressure sensor 140 exceeds an upper limit value and increasing the screw rotation speed when the detection value falls below a lower limit value. The upper and lower limits are determined, for example, as a value obtained by multiplying a predicted pressure value when a certain amount of plasticizing material is being discharged by a certain ratio. For example, the upper limit is set to 105% of the predicted pressure value, and the lower limit is similarly set to 95% of the predicted pressure value. In this case, the closer the ratio for determining the upper and lower limits is to 100%, the narrower the allowable pressure range.

[0046] 5 is a flowchart of the modeling data generation process executed by the control unit 101. The modeling data generation process is a process for generating modeling data to be used in modeling a three-dimensional object prior to modeling the three-dimensional object.

[0047] 5, in step S100, the control unit 101 acquires three-dimensional data representing the shape of a three-dimensional object. The control unit 101 acquires three-dimensional data such as three-dimensional CAD data from an external source, for example, via a network or a recording medium.

[0048] In step S110, the reception unit 102 receives a selection of a modeling mode from the user. For example, the control unit 101 displays the names of each modeling mode on the display unit 105, and the user selects a desired modeling mode from the list using an input device such as a mouse or a keyboard. Step S110 is also referred to as the first step in the method for manufacturing a three-dimensional object.

[0049] 6 is a diagram showing examples of modeling modes. In this embodiment, a first mode, a second mode, and a third mode are provided as modes related to the accuracy of the three-dimensional object or the modeling time of the three-dimensional object. These modes differ in the accuracy of the three-dimensional object to be modeled and the modeling time until the three-dimensional object is completed.

[0050] The first mode corresponds to a high-precision mode in which a three-dimensional object is formed with high precision. In addition, in this embodiment, the first mode also corresponds to a low-speed mode in which a three-dimensional object is formed at a low speed. More specifically, as shown in FIG. 6 , in the first mode in this embodiment, the precision of the three-dimensional object is higher than in the second mode and the third mode, and the time required to form the three-dimensional object is longer than in the second mode and the third mode. Hereinafter, the first mode may also be simply referred to as the high-precision mode or the low-speed mode. Note that in the first mode in this embodiment, the strength of the three-dimensional object is higher than in the second mode and the third mode. Therefore, the first mode in this embodiment can also be said to be a mode in which a three-dimensional object is formed with high strength.

[0051] The third mode corresponds to a high-speed mode in which a three-dimensional object is formed at high speed. In addition, in this embodiment, the third mode also corresponds to a low-precision mode in which a three-dimensional object is formed with low precision. More specifically, as shown in FIG. 6 , in the third mode in this embodiment, the precision of the three-dimensional object is lower than in the first mode and the second mode, and the time required to form the three-dimensional object is shorter than in the first mode and the second mode. Hereinafter, the third mode may also be simply referred to as the high-speed mode or the low-precision mode. In addition, in the third mode in this embodiment, the strength of the three-dimensional object is lower than in the first mode and the second mode. Therefore, the first mode in this embodiment can also be said to be a mode in which a three-dimensional object is formed with low strength.

[0052] The second mode corresponds to a standard mode in which a three-dimensional object is formed with standard accuracy and at a standard speed. In addition, in the second mode in this embodiment, a three-dimensional object is formed with standard strength.

[0053] In step S120 of Fig. 5, the modeling data generation unit 103 determines modeling data generation conditions according to the modeling mode accepted in step S110. As shown in Fig. 6, various modeling data generation conditions are determined and stored in the storage device of the control unit 101 in order to realize the strength and modeling time according to each modeling mode. The modeling data generation unit 103 sets the modeling data generation conditions according to the modeling mode by referring to the storage device of the control unit 101. As shown in Fig. 6, the modeling data generation conditions in this embodiment include layering conditions and control conditions for the plasticizing unit 30.

[0054] The lamination conditions include the line width, lamination pitch, internal filling rate, complexity of the filling pattern, and the movement speed of the nozzle 61. The control conditions for the plasticizing section 30 include the screw rotation speed, screw rotation control sensitivity, screw rotation control count, set temperature of the first heating section 121, set temperature of the second heating section 122, set temperature of the cooling section 130, temperature gradient of the plasticizing section 30, and the magnitude of the allowable range of pressure used for feedback control of the plasticizing section 30 described above. The screw rotation control sensitivity represents the sensitivity of changes in the screw rotation speed to changes in the movement speed of the nozzle 61 described above. The screw rotation control count represents the number of rotation controls of the flat screw 40 per unit time.

[0055] In FIG. 6, for ease of understanding, the modeling data generation conditions are shown using 10-level indices represented by integers from 1 to 10 for each condition, such as line width, layer pitch, and fill pattern complexity. For each condition, the larger the index value, the greater the value or degree of the specified condition. For example, a larger line width value indicates a thicker line width, a larger layer pitch value indicates a larger layer pitch, and a larger fill pattern complexity value indicates a more complex fill pattern. The same values ​​indicate that the values, etc., specified by each condition are approximately the same. For example, the line width in the first mode is set to be approximately the same or thinner than the line width in the second mode. The modeling data generation conditions shown in FIG. 6 are merely exemplary; other conditions may be defined, and some of the conditions shown in FIG. 6 may be omitted.

[0056] 6, in the first mode of this embodiment, compared to the third mode, the following lamination conditions are set: a thinner line width, a narrower layer pitch, a higher filling rate, a more complex filling pattern, and a slower movement speed of the nozzle 61. In addition, in the first mode, compared to the third mode, the following control conditions are set for the plasticizing section 30: (1) a lower screw rotation speed, (2) a lower set temperature for the heating section 120, (3) a lower set temperature for the cooling section 130, (4) an increased number of screw rotation controls, (5) a smaller temperature gradient for the plasticizing section 30, and (6) an increased screw rotation control sensitivity.

[0057] In this embodiment, as described above, when the first mode is selected, the line width is set to be narrower than when the third mode is selected. To achieve this line width, the screw rotation speed, the set temperature of the first heating unit 121, the set temperature of the second heating unit 122, the set temperature of the cooling unit 130, and the temperature gradient of the plasticizing unit 30 are set as control conditions for the plasticizing unit 30. Furthermore, in this embodiment, when the first mode is selected, the layer pitch is set to be narrower and the movement speed of the nozzle 61 is set to be slower than when the third mode is selected. Therefore, the above control conditions are set taking into account the layer pitch and the movement speed of the nozzle 61.

[0058] As shown in FIG. 6 , in this embodiment, the movement speed of the nozzle 61, which is set as a lamination condition, includes the movement speed when forming the outer shell region of the three-dimensional object and the movement speed when forming the inner region of the three-dimensional object. Furthermore, the screw rotation speed, which is set as a control condition of the plasticizing unit 30, includes the rotation speed when forming the outer shell region and the rotation speed when forming the inner region. The outer shell region is a region that contacts the inside of the outer shell represented by the layer data (described later) and affects the appearance of the three-dimensional object. The inner region is a region inside the outer shell represented by the layer data and is a region of the three-dimensional object other than the outer shell region. The inner region has a greater impact on the strength of the three-dimensional object than on the appearance of the three-dimensional object.

[0059] In this embodiment, when the first mode is selected, the movement speed when printing the outer shell region and the movement speed when printing the internal region are set to be slower than when the third mode is selected, and both the screw rotation when printing the outer shell region and the screw rotation number when printing the internal region are set to be reduced depending on the movement speed setting. Furthermore, when the first mode is selected, the movement speed when printing the internal region is set to be the same or slower than when the second mode is selected, and the movement speed when printing the outer shell region is set to be the same or slower depending on the movement speed setting, and the screw rotation number when printing the internal region is set to be the same or slower depending on the movement speed setting.

[0060] Returning to FIG. 5 for the explanation, in step S130, the modeling data generation unit 103 analyzes the three-dimensional data acquired in step S100 and generates layer data by slicing the three-dimensional object into multiple layers along the XY plane. The slicing interval is set according to the layer pitch of the modeling data generation conditions determined in step S120. The layer data is data that represents the outer shell of the three-dimensional object in the XY plane. FIG. 7 is a diagram showing an example of layer data LD. In FIG. 7, the part corresponding to the outer shell represented by the layer data LD is indicated by a thick line.

[0061] In step S140 of FIG. 5, the modeling data generation unit 103 generates shell modeling data for forming an outer shell region in accordance with the modeling data generation conditions determined in step S120. The shell modeling data includes a path for forming the outermost periphery along the outer shell of the three-dimensional object. The shell modeling data may include not only path information for forming the outermost periphery of the three-dimensional object, but also path information including, for example, one lap around the innermost periphery. The number of laps of the path information for forming the outer shell region may be set arbitrarily.

[0062] 7 shows an example in which the outer shell forming data ZD1 is composed of the outermost path information and the path information for one circumference around the outer shell. This path information includes multiple partial paths PP1 for forming the outer shell region. As described above, each partial path PP1 is a linear path. Each partial path PP1 is associated with the discharge amount information indicating the amount of plasticized material deposited on the stage 210 that will result in the line width Ss specified in the forming data generation conditions.

[0063] In step S150 of FIG. 5, the modeling data generation unit 103 generates interior modeling data for modeling the internal region in accordance with the modeling data generation conditions determined in step S120.

[0064] FIG. 7 shows an example in which the internal shaping data ZD2 is represented inside the outer shell shaping data ZD1. In FIG. 7, the path information filling the internal region represented by the internal shaping data ZD2 is formed in a meandering manner using multiple partial paths PP2. As described above, each partial path PP2 is a linear path. The path information representing the internal shaping data ZD2 is determined by the internal filling rate and filling pattern specified in the shaping data generation conditions. The lower the internal filling rate, the wider the spacing between adjacent paths, resulting in a path with more gaps. Furthermore, the more complex the filling pattern, the more corners there are in the movement path, i.e., the more partial paths there are. Examples of filling patterns include grids, triangles, concentric circles, and honeycombs. A pattern that meets the complexity level specified in the shaping data generation conditions is specified for each shaping data generation condition. Each partial path PP2 included in the internal shaping data ZD2 is associated with a discharge amount, which corresponds to the line width specified in the shaping data generation conditions, as discharge amount information.

[0065] Hereinafter, the outer shell molding data generated in step S140 and the inner shell molding data generated in step S150 will be collectively referred to simply as "molding data."

[0066] In this embodiment, the modeling data includes the above-mentioned control information. The control information includes speed information, which is information for controlling the movement speed of the nozzle 61, and plasticization information, which is information for controlling the plasticizing unit 30. The speed information and the plasticization information are specified based on the modeling data generation conditions determined in step S120. Note that the control information may also include information for controlling, for example, the discharge control unit 70 and the suction / discharge unit 75.

[0067] In this embodiment, the plasticization information of the modeling data includes rotation control frequency information for specifying the screw rotation control frequency. The rotation control frequency information includes information regarding the frequency at which the detection value of the pressure sensor 140 is acquired and information for specifying the above-described allowable pressure range. The control unit 101 generates the rotation control frequency information according to the screw rotation control count included in the control conditions of the plasticization unit 30. For example, when the first mode is selected, the control unit 101 generates at least one of information for shortening the interval between acquisition of a detection value from the pressure sensor 140 and the next acquisition of a detection value or information for narrowing the allowable pressure range as the rotation control frequency information, compared to when the third mode is selected. As a result, when the first mode is selected, the screw rotation control count for modeling a three-dimensional object is increased compared to when the third mode is selected. Increasing the screw rotation control count in this way can suppress sudden changes in the screw rotation speed, thereby more stabilizing the discharge amount of plasticization material and improving the accuracy of the three-dimensional object.

[0068] In this embodiment, the plasticization information also includes rotation control sensitivity information, which is information for specifying the screw rotation control sensitivity. The rotation control sensitivity information is expressed by a function that defines the relationship between the movement speed of the nozzle 61 and the screw rotation speed. When forming a three-dimensional object, the control unit 101 controls the movement speed of the nozzle 61 and the screw rotation speed in accordance with this function, thereby achieving the change in the screw rotation speed in response to the change in the movement speed of the nozzle 61 described above. The control unit 101 specifies, as the rotation control sensitivity information, a different function depending on the selected modeling mode. These functions may be functions that, as a whole, change the screw rotation speed in response to the movement speed of the nozzle 61. For example, they may be defined as a step function having a portion where the screw rotation speed does not change in response to the movement speed of the nozzle 61.

[0069] More specifically, when the first mode is selected, the control unit 101 specifies, as the rotation control sensitivity information, a function that can increase the control sensitivity of the screw rotation speed with respect to the movement speed of the nozzle 61 compared to when the third mode is selected. When the control sensitivity of the screw rotation speed is high, the screw rotation speed changes in response to smaller changes in the movement speed of the nozzle 61 compared to when the control sensitivity is low. For example, the function specified when the first mode is selected is defined as a function that changes the screw rotation speed with respect to the movement speed of the nozzle 61 in more stages compared to the function specified when the third mode is selected. In other embodiments, for example, the function specified when the first mode is selected may be a higher-order function compared to the function specified when the third mode is selected.

[0070] 5, the shaping data generation unit 103 determines whether the above process has been completed for all layer data. If the process has not been completed for all layer data, the shaping data generation unit 103 repeats the processes of steps S140 and S150 for the next layer data. If the generation of shaping data for all layer data has been completed, the shaping data generation unit 103 ends the shaping data generation process.

[0071] Fig. 8 is a flowchart of the three-dimensional printing process executed by the control unit 101. The three-dimensional printing process is a process executed by the control unit 101 using the printing data generated in the printing data generation process shown in Fig. 5. By executing the printing data generation process shown in Fig. 5 and the three-dimensional printing process shown in Fig. 8, a method for manufacturing a three-dimensional object by the three-dimensional printing device 100 is realized.

[0072] In step S200, the control unit 101 acquires the shaping data generated by the shaping data generation process described above. Then, in step S210, the control unit 101 reads shaping data for one of the multiple layers constituting the three-dimensional object from the shaping data. In this embodiment, the control unit 101 first reads shaping data for the layer located at the bottom of the multiple layers constituting the three-dimensional object.

[0073] In step S220, the control unit 101 executes a first modeling process. In the first modeling process, the control unit 101 executes a second process and a third process to form an outer shell region for the current layer. The second process refers to a process of plasticizing at least a portion of the material using the plasticizing unit 30 to generate a plasticized material. The third process refers to a process of discharging the plasticized material generated in the second process from the nozzle 61 toward the stage 210 while moving the nozzle 61 relative to the stage 210.

[0074] In this embodiment, in the first modeling process, the control unit 101 controls the movement mechanism 230, the plasticizing unit 30, and the discharging unit 60 in accordance with the partial paths, dispensing amount information, speed information, and control information for the plasticizing unit 30 included in the outer shell modeling data to form an outer shell region for the current layer. As a result, in the second process, control of the plasticizing unit 30 is realized in accordance with the modeling mode accepted in the first process. Note that in this embodiment, in the second process, the control unit 101 individually controls the first heating unit 121 and the second heating unit 122 of the heating unit 120 in accordance with the respective set temperatures included in the outer shell modeling data. Similarly, in the third process, control of the movement mechanism 230 and the discharging unit 60 in accordance with the modeling mode is realized.

[0075] In step S230, the control unit 101 executes the second modeling process. In the second modeling process, the control unit 101 executes the second step and the third step in the same manner as in the first modeling process described above, thereby forming an internal region for the current layer. More specifically, in the second modeling process, the control unit 101 controls the moving mechanism 230, the plasticizing unit 30, and the discharging unit 60 in accordance with the partial paths, discharge amount information, speed information, and control information for the plasticizing unit 30 included in the internal modeling data, to form an internal region for the current layer.

[0076] In step S240, the control unit 101 determines whether modeling has been completed for all layers. If modeling has not been completed for all layers, the control unit 101 returns the process to step S210 and executes the processes of steps S210 to S230 for the next layer, i.e., the layer adjacent to and above the current layer. In this case, in step S220, prior to the discharge of the plasticizable material from the discharge unit 60, the control unit 101 controls the movement mechanism 230 to raise the position of the nozzle 61 by the distance of one layer. If it is determined in step S240 that modeling has been completed for all layers, the control unit 101 completes the three-dimensional modeling process.

[0077] According to the first embodiment described above, in the second step, the plasticizing unit 30 is controlled in accordance with the modeling mode received in the first step. Therefore, the user can simply select a modeling mode to model a three-dimensional object having characteristics corresponding to the modeling mode, without having to finely adjust the control data of the plasticizing unit 30 and repeatedly make prototypes.

[0078] Furthermore, according to this embodiment, the modeling mode includes at least one of a mode related to the modeling accuracy of the three-dimensional object and a mode related to the modeling time of the three-dimensional object, so that the user can easily select the desired modeling mode from the modes prepared according to the modeling accuracy or modeling time.

[0079] Furthermore, according to this embodiment, when the high-precision mode or the low-speed mode is selected, the temperature gradient of the plasticizing unit 30 is reduced by changing at least one of the set temperatures of the heating unit 120 and the cooling unit 130 compared to when the low-precision mode or the high-speed mode is selected. As a result, the amount of plasticizing material discharged from the plasticizing unit 30 to the nozzle 61 can be reduced in the high-precision mode or the low-speed mode compared to when the low-precision mode or the high-speed mode is selected. Therefore, in the third step when the high-precision mode is selected, the amount of plasticizing material discharged from the nozzle 61 per unit time can be reduced, for example, in accordance with the slower setting of the movement speed of the nozzle 61 and the thinner setting of the line width of the plasticizing material compared to when the high-precision mode or the low-precision mode is selected.

[0080] Furthermore, in this embodiment, when the high-precision mode or the low-speed mode is selected, the allowable pressure range is narrower than when the low-precision mode or the high-speed mode is selected. This makes it possible to more stabilize the amount of plasticized material discharged from the nozzle 61 in the high-precision mode or the low-speed mode compared to the low-precision mode or the high-speed mode, thereby improving the modeling accuracy of the three-dimensional object.

[0081] Furthermore, in this embodiment, when the high-precision mode or the low-speed mode is selected, the screw rotation speed is reduced when forming at least one of the outer shell region and the inner region of a three-dimensional object, compared to when the low-precision mode or the high-speed mode is selected. As a result, when the high-precision mode or the low-speed mode is selected, the amount of plasticizing material delivered from the plasticizing unit 30 to the nozzle 61 can be reduced when forming the outer shell region and the inner region, compared to when the low-precision mode or the high-speed mode is selected. Therefore, in the third step when the high-precision mode is selected, the amount of plasticizing material discharged from the nozzle 61 per unit time can be reduced in accordance with the slower movement speed of the nozzle 61 and the thinner line width of the plasticizing material, compared to when the high-precision mode or the low-precision mode is selected. Furthermore, when the high-precision mode or the low-speed mode is selected, the screw rotation speed may be reduced, for example, only when forming the outer shell region or only when forming the inner region. For example, in high-precision mode or low-speed mode, by reducing the screw rotation speed only when forming the outer shell region, it is possible to accurately form the parts that have a large impact on the appearance of the three-dimensional object while shortening the forming time.

[0082] Furthermore, in this embodiment, when the high-precision mode or the low-speed mode is selected, the control sensitivity of the screw rotation speed relative to the movement speed of the nozzle 61 is higher than when the low-precision mode or the high-speed mode is selected. As a result, in the high-precision mode or the low-speed mode, even if the movement speed of the nozzle 61 changes during modeling of a three-dimensional object, the amount of plasticizing material discharged from the nozzle 61 can be controlled with higher precision in accordance with changes in the movement speed than when the low-precision mode or the high-speed mode is selected. Therefore, for example, even if the movement speed changes as the nozzle 61 changes direction during modeling, the line width and the like can be controlled with higher precision in the high-precision mode or the low-speed mode, allowing a three-dimensional object to be modeled with higher precision.

[0083] Furthermore, in this embodiment, the heating unit 120 has a first heating unit 121 and a second heating unit 122 that is closer to the communicating holes 56 than the first heating unit 121 when viewed along the Z direction, and in the second step, the first heating unit 121 and the second heating unit 122 are individually controlled according to the modeling mode selected in the first step. Therefore, in the second step, the temperature of the region closer to the communicating holes 56 and the temperature of the region farther from the communicating holes 56 when viewed along the Z direction in the plasticizing unit 30 can be easily individually controlled according to the modeling mode.

[0084] B. Other Embodiments: (B1) In the above embodiment, the modeling mode does not necessarily include both a mode related to the accuracy of the 3D object and a mode related to the modeling time of the 3D object, and may include only one of them. For example, the modeling mode may include only a mode related to the modeling time of the 3D object, and the mode related to the modeling time of the 3D object may include a mode related to the strength of the 3D object, a mode related to the surface roughness, a mode related to the fill rate, etc. The reason why these modes correspond to the mode related to the modeling time is that the strength, surface roughness, and fill rate of the 3D object significantly affect the modeling time of the 3D object. For example, increasing the strength requires narrowing the line width, narrowing the layer pitch, increasing the fill rate, complicating the fill pattern, and so on, which increases the modeling time. Similarly, increasing the surface roughness or increasing the fill rate also increases the modeling time.

[0085] (B2) In the above embodiment, the modeling data is generated according to the modeling mode selected in the first step, and the plasticizing unit 30 is controlled according to the generated modeling data in the second step, thereby realizing the control of the plasticizing unit 30 according to the modeling mode. However, it is not necessary to generate the modeling data according to the modeling mode. For example, control data including control values ​​for controlling the plasticizing unit 30 according to the modeling mode may be generated separately from the modeling data, and the plasticizing unit 30 may be controlled according to the control data in the second step, thereby realizing the control of the plasticizing unit 30 according to the modeling mode.

[0086] (B3) In the above embodiment, when the high-precision mode or the low-speed mode is selected as the modeling mode, all of the screw rotation speed, the set temperature of the heating unit 120, the set temperature of the cooling unit 130, and the number of screw rotation control times are made different compared to when the low-precision mode or the high-speed mode is selected. In contrast, when the high-precision mode or the low-speed mode is selected, at least one of the above may be made different compared to when the low-precision mode or the high-speed mode is selected.

[0087] (B4) In the above embodiment, when the high-precision mode or the low-speed mode is selected as the modeling mode, all of the following are performed compared to when the low-precision mode or the high-speed mode is selected: (1) reducing the screw rotation speed, (2) lowering the set temperature of the heating unit 120, (3) lowering the set temperature of the cooling unit 130, and (4) increasing the number of screw rotation control times. In contrast, when the high-precision mode or the low-speed mode is selected, at least one of the above may be performed.

[0088] (B5) In the above embodiment, when the high-precision mode or the low-speed mode is selected as the modeling mode, the temperature gradient of the plasticizing unit 30 is made smaller than when the low-precision mode or the high-speed mode is selected. In contrast, when the high-precision mode or the low-speed mode is selected, the temperature gradient of the plasticizing unit 30 does not need to be made smaller. For example, the temperature gradient of the plasticizing unit 30 when the high-precision mode or the low-speed mode is selected may be the same as the temperature gradient of the plasticizing unit 30 when the low-precision mode or the high-speed mode is selected.

[0089] (B6) In the above embodiment, in the second step, the screw rotation speed is controlled so that the detection value of the pressure sensor 140 falls within a predetermined allowable range. However, for example, the set temperature of the heating unit 120 or the set temperature of the cooling unit 130 may be controlled instead of the screw rotation speed so that the detection value of the pressure sensor 140 falls within the allowable range. Similarly, the set temperature of the heating unit 120 or the set temperature of the cooling unit 130 may be controlled in addition to the screw rotation speed so that the detection value falls within the allowable range. In other words, at least one of the screw rotation speed, the set temperature of the heating unit 120, and the set temperature of the cooling unit 130 may be controlled so that the detection value falls within the allowable range.

[0090] (B7) In the above embodiment, when the high-precision mode or the low-speed mode is selected as the modeling mode, the allowable pressure range of the plasticized material in the flow path 69 is narrower than when the low-precision mode or the high-speed mode is selected. In contrast, the allowable pressure range does not need to be narrowed when the high-precision mode or the low-speed mode is selected as the modeling mode. For example, the allowable pressure range when the high-precision mode or the low-speed mode is selected may be the same as the allowable pressure range when the low-precision mode or the high-speed mode is selected. Furthermore, in the second process, the screw rotation speed, the set temperature of the heating unit 120, and the set temperature of the cooling unit 130 do not need to be controlled so that the detection value of the pressure sensor 140 falls within the allowable range. In this case, the three-dimensional modeling device 100 does not need to be equipped with the pressure sensor 140.

[0091] (B8) In the above embodiment, when the high-precision mode or the low-speed mode is selected as the modeling mode, the screw rotation speed changes with higher sensitivity to the movement speed of the nozzle 61 compared to when the low-precision mode or the high-speed mode is selected. In contrast, when the high-precision mode or the low-speed mode is selected as the modeling mode, the screw rotation speed does not have to change with higher sensitivity to the movement speed of the nozzle 61. For example, the screw rotation control sensitivity when the high-precision mode or the low-speed mode is selected may be the same as the screw rotation control sensitivity when the low-precision mode or the high-speed mode is selected.

[0092] (B9) In the above embodiment, the heating unit 120 includes the first heating unit 121 and the second heating unit 122, and in the second step, the first heating unit 121 and the second heating unit 122 are individually controlled according to the modeling mode. However, for example, the heating unit 120 may include three or more heating units, and in the second step, each heating unit may be individually controlled according to the modeling mode. The heating unit 120 may have only one heating unit. Furthermore, in the second step, each heating unit may not be individually controlled according to the modeling mode.

[0093] (B10) In the above embodiment, the heating section 120 and the cooling section 130 are provided in the barrel 50 of the plasticizing section 30. However, part or all of the heating section 120 and the cooling section 130 may be provided in the flat screw 40. In this case, for example, either the first heating section 121 or the second heating section 122 may be provided in the flat screw 40, and the other may be provided in the barrel 50.

[0094] (B11) In the above embodiment, the temperature gradient in the plasticizing unit 30 is generated by controlling the first heating unit 121, the second heating unit 122, and the cooling unit 130. In contrast, the temperature gradient in the plasticizing unit 30 may be generated by controlling, for example, only one of the heating unit 120 and the cooling unit 130. When the temperature gradient in the plasticizing unit 30 is generated by controlling only the heating unit 120, the plasticizing unit 30 does not need to be provided with the cooling unit 130.

[0095] (B12) In the above embodiment, the three-dimensional modeling apparatus 100 is provided with the suction and discharge unit 75. However, the three-dimensional modeling apparatus 100 does not have to be provided with the suction and discharge unit 75.

[0096] (B13) In the above embodiment, the discharge control unit 70 controls the on / off of the discharge of the plasticizing material. In addition, the discharge control unit 70 may be configured to adjust the amount of plasticizing material flowing through the supply flow path 65, for example, by changing the opening of the supply flow path 65. In this case, the discharge control unit 70 changes the opening of the supply flow path 65 depending on the amount of plasticizing material sent from the plasticizing unit 30 to the supply flow path 65, for example.

[0097] (B14) In the above embodiment, the control unit 101 slows the movement speed of the nozzle 61 below the normal speed when the nozzle 61 changes direction by 60° or more while discharging the plasticizing material, when stopping the movement of the nozzle 61 and discharging the plasticizing material, or when starting or restarting the movement of the nozzle 61 and discharging the plasticizing material. Alternatively, or in addition to these, the control unit 101 may slow the movement speed of the nozzle 61 below the normal speed, for example, along a path whose length is shorter than a predetermined length. For example, a path for forming a fine part of a three-dimensional object or multiple consecutive paths for forming a curved part corresponds to such a short path length. By changing the screw rotation speed in conjunction with the movement speed of the nozzle 61 along these paths, the precision of the fine part or the curved part of the three-dimensional object can be improved.

[0098] (B15) In the above embodiment, the control unit 101 executes both the modeling data generation process and the three-dimensional modeling process. However, the modeling data generation process and the three-dimensional modeling process may be executed by different control units. In this case, for example, the control unit that executes the modeling data generation process is configured as an information processing device, and the control unit that executes the three-dimensional modeling process is provided in the three-dimensional modeling device. The information processing device then includes a transmitting unit that transmits the modeling data to the three-dimensional modeling device.

[0099] (B16) In the above embodiment, pelletized ABS resin material is used as the raw material supplied to the material supply unit 20. In contrast, the 3D printing apparatus 100 can print a 3D object using various materials as the main material, such as thermoplastic materials, metal materials, and ceramic materials. Here, the term "main material" refers to the material that forms the core of the shape of the 3D object, and refers to a material that accounts for 50% or more by weight of the 3D object. The plasticized materials mentioned above include those main materials that are melted alone, and those that are made into a paste by melting some of the components contained in the main material.

[0100] When a thermoplastic material is used as the main material, the material is plasticized in the plasticizing section 30 to produce a plasticized material. "Plasticization" means that heat is applied to a thermoplastic material to melt it.

[0101] As the material having thermoplasticity, for example, the following thermoplastic resin materials can be used. <Examples of thermoplastic resin materials> General-purpose engineering plastics such as polypropylene resin (PP), polyethylene resin (PE), polyacetal resin (POM), polyvinyl chloride resin (PVC), polyamide resin (PA), acrylonitrile butadiene styrene resin (ABS), polylactic acid resin (PLA), polyphenylene sulfide resin (PPS), polyether ether ketone (PEEK), polycarbonate (PC), modified polyphenylene ether, polybutylene terephthalate, and polyethylene terephthalate; and engineering plastics such as polysulfone, polyethersulfone, polyphenylene sulfide, polyarylate, polyimide, polyamideimide, polyetherimide, and polyether ether ketone.

[0102] The thermoplastic material may contain pigments, metals, ceramics, and other additives such as wax, flame retardants, antioxidants, and thermal stabilizers. The thermoplastic material is plasticized and converted into a molten state in the plasticizing section 30 by the rotation of the flat screw 40 and the heat of the heater 58. The plasticized material produced by melting the thermoplastic material is discharged from the nozzle 61 and then hardens as the temperature drops.

[0103] It is desirable that the thermoplastic material be heated to or above its glass transition point and in a completely melted state before being injected from the nozzle 61. For example, ABS resin has a glass transition point of approximately 120°C, and it is desirable that the temperature be approximately 200°C when injected from the nozzle 61.

[0104] In the three-dimensional modeling apparatus 100, for example, the following metal materials may be used as the main material instead of the thermoplastic materials described above. In this case, it is desirable that the powder material made by powdering the following metal materials be mixed with a component that melts when the plasticized material is produced, and then the powder material is introduced into the plasticizing unit 30 as a raw material. <Examples of metal materials> A single metal, or an alloy containing one or more of the following metals: magnesium (Mg), iron (Fe), cobalt (Co), chromium (Cr), aluminum (Al), titanium (Ti), copper (Cu), or nickel (Ni). <Examples of the alloy> Maraging steel, stainless steel, cobalt chrome molybdenum, titanium alloy, nickel alloy, aluminum alloy, cobalt alloy, cobalt chrome alloy.

[0105] In the three-dimensional modeling apparatus 100, a ceramic material can be used as the main material instead of the above-mentioned metal materials. Examples of ceramic materials that can be used include oxide ceramics such as silicon dioxide, titanium dioxide, aluminum oxide, and zirconium oxide, and non-oxide ceramics such as aluminum nitride. When using the above-mentioned metal or ceramic materials as the main material, the plasticized material placed on the stage 210 may be hardened by sintering using laser irradiation, hot air, or the like.

[0106] The powder material of a metal or ceramic material fed as a raw material to the material supply unit 20 may be a mixed material obtained by mixing multiple types of powder of a single metal, alloy powder, or ceramic material. The powder material of a metal or ceramic material may also be coated with, for example, the thermoplastic resin exemplified above or a different thermoplastic resin. In this case, the thermoplastic resin may be melted in the plasticizing unit 30 to exhibit fluidity.

[0107] For example, the following solvents can be added to the powdered metal or ceramic material fed as raw material to the material supply unit 20. The solvent can be one or a combination of two or more selected from the following: <Examples of solvents> water; (poly)alkylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, and propylene glycol monoethyl ether; acetate esters such as ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, and isobutyl acetate; aromatic hydrocarbons such as benzene, toluene, and xylene; ketones such as methyl ethyl ketone, acetone, methyl isobutyl ketone, ethyl-n-butyl ketone, diisopropyl ketone, and acetylacetone; alcohols such as ethanol, propanol, and butanol; tetraalkylammonium acetates; sulfoxide-based solvents such as dimethyl sulfoxide and diethyl sulfoxide; pyridine-based solvents such as pyridine, γ-picoline, and 2,6-lutidine; tetraalkylammonium acetates (for example, tetrabutylammonium acetate); and ionic liquids such as butyl carbitol acetate.

[0108] In addition, the powder material of the metal material or ceramic material fed into the material supply unit 20 as a raw material may also contain, for example, the following binders. <Example of binder> Acrylic resin, epoxy resin, silicone resin, cellulose-based resin or other synthetic resin, or PLA (polylactic acid), PA (polyamide), PPS (polyphenylene sulfide), PEEK (polyether ether ketone) or other thermoplastic resin.

[0109] C. Other forms: The present disclosure is not limited to the above-described embodiments and can be realized in various forms without departing from the spirit thereof. For example, the present disclosure can also be realized in the following forms. The technical features in the above embodiments corresponding to the technical features in each form described below can be appropriately replaced or combined to solve some or all of the problems of the present disclosure or to achieve some or all of the effects of the present disclosure. Furthermore, if a technical feature is not described as essential in this specification, it can be appropriately deleted.

[0110] (1) According to a first aspect of the present disclosure, there is provided a method for manufacturing a three-dimensionally shaped object. The method for manufacturing a three-dimensionally shaped object includes: a first step of accepting a selection of a modeling mode for the three-dimensionally shaped object; a second step of plasticizing at least a portion of a material to generate a plasticized material using a plasticizing unit including a rotating flat screw having a groove-forming surface with grooves formed thereon and a barrel having an opposing surface facing the groove-forming surface and formed with a communication hole communicating with a nozzle; and a third step of ejecting the plasticized material from the nozzle toward a stage. In the second step, the plasticizing unit is controlled according to the modeling mode accepted in the first step. According to this configuration, the user can create a three-dimensional object with characteristics corresponding to the modeling mode simply by selecting the modeling mode, without having to fine-tune the control data of the plasticization unit and repeatedly make prototypes.

[0111] (2) In the above aspect, the modeling mode may include at least one of a mode related to the modeling accuracy of the three-dimensional object and a mode related to the modeling time of the three-dimensional object. According to this aspect, a user can easily select a desired modeling mode from modes prepared according to the modeling accuracy or the modeling time.

[0112] (3) In the above embodiment, when a high-precision mode in which the three-dimensional object is formed with high precision or a low-speed mode in which the three-dimensional object is formed at a low speed is selected as the forming mode, at least one of the number of rotations per unit time of the flat screw, the set temperature of the heating section that heats the material supplied between the groove forming surface and the opposing surface, the set temperature of the cooling section that cools the plasticizing section, and the number of rotations of the flat screw per unit time may be made different compared to when a low-precision mode in which the three-dimensional object is formed with low precision or a high-speed mode in which the three-dimensional object is formed at a high speed is selected as the forming mode.

[0113] (4) In the above embodiment, when the high-precision mode or the low-speed mode is selected as the modeling mode, at least one of the following may be performed, compared to when the low-precision mode or the high-speed mode is selected: (A) reducing the rotation speed; (B) lowering the set temperature of the heating unit; (C) lowering the set temperature of the cooling unit; or (D) increasing the number of rotation controls.

[0114] (5) In the above embodiment, when the high-precision mode or the low-speed mode is selected, the temperature gradient in the plasticizing section, which increases from the outer edge of the opposing surface toward the communicating hole when viewed along the direction in which the groove-forming surface and the opposing surface face each other, may be reduced by changing at least one of the set temperature of the heating section and the set temperature of the cooling section compared to when the low-precision mode or the high-speed mode is selected. According to this embodiment, the amount of plasticizing material dispensed from the plasticizing section to the nozzle can be reduced in the high-precision mode or the low-speed mode compared to when the low-precision mode or the high-speed mode is selected. Therefore, for example, in the third step when the high-precision mode is selected, the amount of plasticizing material dispensed from the nozzle per unit time can be reduced in accordance with a slower nozzle movement speed and a thinner line width of the plasticizing material compared to when the high-precision mode or the low-precision mode is selected.

[0115] (6) In the above embodiment, in the second step, at least one of the rotation speed, the set temperature of the heating unit, and the set temperature of the cooling unit may be controlled so that a detection value of a pressure sensor that detects the pressure in the flow path through which the plasticizing material flows falls within a predetermined tolerance range, and when the high-precision mode or the low-speed mode is selected, the tolerance range may be narrower than when the low-precision mode or the high-speed mode is selected. According to this embodiment, the amount of plasticizing material ejected from the nozzle can be more stable in the high-precision mode or the low-speed mode than in the low-precision mode or the high-speed mode, and the modeling accuracy of the three-dimensional object can be improved.

[0116] (7) In the above-described embodiment, when the high-precision mode or the low-speed mode is selected, the rotation speed may be reduced compared to when the low-precision mode or the high-speed mode is selected, at least in one of forming the outer shell region of the three-dimensional object and forming the inner region of the three-dimensional object that is located inside the outer shell region. According to this embodiment, when the high-precision mode or the low-speed mode is selected, the amount of plasticizing material delivered from the plasticizing unit to the nozzle can be reduced compared to when the low-precision mode or the high-speed mode is selected, when forming the outer shell region or the inner region. Therefore, in the third step when the high-precision mode is selected, the amount of plasticizing material dispensed from the nozzle per unit time can be reduced in accordance with the slower nozzle movement speed and the thinner line width of the plasticizing material, compared to when the high-precision mode or the low-precision mode is selected.

[0117] (8) In the above embodiment, the rotation speed in the second step may be changed in conjunction with the relative movement speed of the nozzle in the third step, and when the high-precision mode or the low-speed mode is selected, the control sensitivity of the rotation speed with respect to the movement speed may be higher than when the low-precision mode or the high-speed mode is selected. According to this embodiment, in the high-precision mode or the low-speed mode, even if the movement speed of the nozzle changes during modeling of a three-dimensional object, the amount of plasticizing material dispensed from the nozzle can be controlled more accurately in accordance with changes in the movement speed than when the low-precision mode or the high-speed mode is selected. Therefore, a three-dimensional object can be modeled with higher accuracy in the high-precision mode or the low-speed mode.

[0118] (9) In the above embodiment, when viewed along the opposing direction of the groove-forming surface and the opposing surface, the heating unit may include a first heating unit and a second heating unit that is closer to the communicating holes than the first heating unit, and in the second step, the first heating unit and the second heating unit may be individually controlled according to the molding mode selected in the first step. According to this embodiment, in the second step, the temperature of a region in the plasticizing unit that is closer to the communicating holes and the temperature of a region farther from the communicating holes when viewed along the opposing direction of the groove-forming surface and the opposing surface can be easily individually controlled according to the molding mode.

[0119] (10) According to a second aspect of the present disclosure, there is provided a three-dimensional modeling apparatus, comprising: a plasticizing unit that plasticizes at least a portion of a material to produce the plasticized material, the plasticizing unit including: a nozzle that discharges a plasticized material toward a stage; a rotating flat screw having a groove-forming surface with grooves formed thereon; and a barrel having an opposing surface facing the groove-forming surface and formed with a communication hole that communicates with the nozzle; and a control unit that controls the plasticizing unit to form a three-dimensional object in accordance with a selected modeling mode. [Explanation of symbols]

[0120] 10...3D modeling system, 20...material supply section, 22...supply channel, 30...plasticization section, 31...screw case, 32...drive motor, 40...flat screw, 42...groove forming surface, 44...material inlet, 45...groove, 46...ridge section, 47...center section, 50...barrel, 52...opposing surface, 54...guide groove, 56...communicating hole, 57...outer edge, 58...heater, 60...discharge section, 61...nozzle, 62...nozzle opening, 65...supply channel, 69...channel, 70...discharge control section, 74... First drive unit, 75...suction and discharge unit, 76...second drive unit, 100...three-dimensional printing device, 101...control unit, 102...reception unit, 103...printing data generation unit, 104...printing processing unit, 105...display unit, 110...printing unit, 120...heating unit, 121...first heating unit, 122...second heating unit, 130...cooling unit, 131...refrigerant flow path, 132...inlet unit, 133...outlet unit, 134...refrigerant circulation device, 140...pressure sensor, 210...stage, 211...printing surface, 230...movement mechanism

Claims

1. a first step of accepting a selection of a modeling mode for a three-dimensional object; a second step of plasticizing at least a portion of the material using a plasticizing unit including a rotating flat screw having a groove-forming surface on which grooves are formed, and a barrel having an opposing surface facing the groove-forming surface and formed with a communication hole communicating with a nozzle, to produce a plasticized material; a third step of ejecting the plasticizing material from the nozzle toward a stage, In the second step, the plasticizing unit is controlled in accordance with the modeling mode accepted in the first step.

2. The method for manufacturing a three-dimensional object according to claim 1, The manufacturing method of a three-dimensional object, wherein the modeling mode includes at least one of a mode related to modeling accuracy of the three-dimensional object and a mode related to modeling time of the three-dimensional object.

3. The method for manufacturing a three-dimensional object according to claim 2, When a high-precision mode in which the three-dimensional object is formed with high precision or a low-speed mode in which the three-dimensional object is formed at a low speed is selected as the modeling mode, at least one of the number of rotations per unit time of the flat screw, the set temperature of a heating section that heats the material supplied between the groove forming surface and the opposing surface, the set temperature of a cooling section that cools the plasticizing section, and the number of rotations of the flat screw per unit time is made different compared to when a low-precision mode in which the three-dimensional object is formed with low precision or a high-speed mode in which the three-dimensional object is formed at a high speed is selected as the modeling mode, When the high-precision mode or the low-speed mode is selected as the modeling mode, at least one of the following is performed, compared to when the low-precision mode or the high-speed mode is selected: (1) the rotation speed is reduced; (2) the set temperature of the heating unit is lowered; (3) the set temperature of the cooling unit is lowered; or (4) the number of rotation controls is increased.

4. The method for manufacturing a three-dimensional object according to claim 3, A method for manufacturing a three-dimensional object, in which when the high-precision mode or the low-speed mode is selected, the temperature gradient rising from the outer edge of the opposing surface toward the communicating hole in the plasticization section when viewed along the direction in which the groove forming surface and the opposing surface face each other is reduced by changing at least one of the set temperature of the heating section and the set temperature of the cooling section compared to when the low-precision mode or the high-speed mode is selected.

5. The method for manufacturing a three-dimensional object according to claim 3 or 4, In the second step, at least one of the rotation speed, the set temperature of the heating unit, and the set temperature of the cooling unit is controlled so that a detection value of a pressure sensor that detects a pressure in a flow path through which the plasticizing material flows falls within a predetermined allowable range; When the high-precision mode or the low-speed mode is selected, the tolerance range is narrowed compared to when the low-precision mode or the high-speed mode is selected.

6. The method for manufacturing a three-dimensional structure according to any one of claims 3 to 5, When the high-precision mode or the low-speed mode is selected, the rotation speed is smaller than when the low-precision mode or the high-speed mode is selected, at least in either case of forming an outer shell region of the three-dimensional object or when forming an internal region inside the outer shell region of the three-dimensional object.

7. The method for manufacturing a three-dimensional structure according to any one of claims 3 to 6, comprising: In the third step, the nozzle is moved relative to the stage; The rotation speed in the second step is changed according to the relative movement speed of the nozzle in the third step; When the high-precision mode or the low-speed mode is selected, the control sensitivity of the rotation speed relative to the moving speed is higher than when the low-precision mode or the high-speed mode is selected.

8. The method for manufacturing a three-dimensional structure according to any one of claims 3 to 7, comprising: When viewed along a direction in which the groove forming surface and the opposing surface oppose each other, the heating unit has a first heating unit and a second heating unit that is closer to the communication hole than the first heating unit, In the second step, the first heating unit and the second heating unit are individually controlled in accordance with the modeling mode selected in the first step.

9. a nozzle that discharges the plasticized material toward the stage; a plasticizing section including a rotating flat screw having a groove-forming surface on which grooves are formed, and a barrel having an opposing surface facing the groove-forming surface and formed with a communication hole communicating with the nozzle, the plasticizing section plasticizing at least a portion of the material to generate the plasticized material; a control unit that controls the plasticizing unit to form a three-dimensional object in accordance with a selected modeling mode.

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