Manufacturing method of three-dimensional molding

Abstract

To provide a manufacturing method of a three-dimensional molding capable of inhibiting a variation of a discharge quantity when resuming a discharge.SOLUTION: A manufacturing method of a three-dimensional molding includes: a first step of plasticizing a material to generate a plasticized material, and feeding the plasticized material to a nozzle opening of a nozzle; a second step of relatively moving the nozzle to a stage while discharging the plasticized material from the nozzle opening to form a layer on the stage; and a third step of suspending the discharge of the plasticized material from the nozzle opening during a movement time when moving the nozzle relatively from a discharge stop position to a discharge resumption position located on the same layer as the discharge stop position. The third step executes a first control of controlling a movement of the nozzle so that a difference between a first movement time being a movement time in a first case in which a distance from the discharge stop position to the discharge resumption position is a first distance and a second movement time being a movement time in a second case in which a distance is a second distance shorter than the first distance is within a prescribed range.SELECTED DRAWING: Figure 10

Description

[Technical field]

[0001] The present disclosure relates to a method for producing a three-dimensional object. [Background technology]

[0002] Patent Document 1 discloses a three-dimensional modeling device equipped with a flow rate adjustment mechanism capable of controlling the amount of molten material discharged from a nozzle. In this three-dimensional modeling device, non-discharge control is performed to stop the discharge of material from the nozzle by adjusting the rotation angle of a butterfly valve. The non-discharge control is performed when it is desired to change the nozzle position without discharging molten material from the nozzle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-81263 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the process of forming a three-dimensional object, the non-discharge control may be performed multiple times, and the period from the stop of discharge to the restart of discharge in each of the non-discharge controls may not be the same. In this case, the pressure in the flow path upstream of the butterfly valve may differ for each non-discharge control, and the discharge amount at the time of restart of discharge may differ for each non-discharge control. [Means for solving the problem]

[0005] According to one aspect of the present disclosure, there is provided a three-dimensional modeling apparatus for forming a three-dimensional object by stacking layers. This manufacturing method includes a first step of plasticizing a material to generate a plasticized material and sending the plasticized material toward a nozzle opening of a nozzle, a second step of discharging the plasticized material from the nozzle opening while the nozzle moves relatively to a stage to form a layer on the stage, and a second step of discharging the plasticized material from the nozzle opening during a movement time during which the nozzle moves relatively to the stage from a discharge stop position where discharge from the nozzle opening is stopped to a discharge restart position located in the same layer as the discharge stop position and where discharge from the nozzle opening is restarted. and a third step of stopping the discharge of the material, in which the third step stops the discharge of the plasticized material from the nozzle opening by adjusting the opening area of ​​the flow path through which the plasticized material flows toward the nozzle opening, and performs a first control to control the movement of the nozzle relative to the stage so that the difference between a first movement time, which is the movement time in a first case in which a movement distance, which is the distance from the discharge stop position to the discharge restart position, is a first distance, and a second movement time, which is the movement time in a second case in which the movement distance is a second distance shorter than the first distance, is within a predetermined range. [Brief description of the drawings]

[0006] [Figure 1] FIG. 1 is an explanatory diagram showing a schematic configuration of a three-dimensional printing system. [Diagram 2] FIG. [Diagram 3] Schematic plan view of a barrel. [Figure 4] FIG. 2 is an explanatory diagram illustrating a process in which the three-dimensional printing apparatus prints a model. [Diagram 5] FIG. 1 is an explanatory diagram showing a schematic configuration of an information processing apparatus. [Figure 6] 13 is a flowchart of a modeling data generation process. [Figure 7] FIG. [Figure 8] Graph showing the relationship between time and pressure. [Figure 9]11 is a graph showing the relationship between travel distance and travel speed, and the relationship between travel distance and travel time. [Figure 10] 4 is a flowchart of a modeling process. [Figure 11] 13A to 13C are views for explaining movement of non-ejection paths in the second embodiment. [Figure 12] 13A to 13C are views for explaining modeling data according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] A. First embodiment: FIG. 1 is an explanatory diagram showing a schematic configuration of a three-dimensional printing system 10 in the first embodiment. In FIG. 1, arrows indicating mutually orthogonal X, Y, and Z directions are shown. The X and Y directions are parallel to a horizontal plane, and the Z direction is a direction along a vertical 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, the direction indicated by the arrow in each figure is indicated as "+" and the opposite direction is indicated as "-", and positive and negative signs are used in combination to indicate the direction. In the following, the +Z direction is also referred to as "up" and the -Z direction is also referred to as "down".

[0008] The three-dimensional printing system 10 includes a three-dimensional printing device 100 and an information processing device 400. The three-dimensional printing device 100 of this embodiment is a device that forms a model by a material extrusion method. The three-dimensional printing device 100 includes a control unit 300 for controlling each unit of the three-dimensional printing device 100. The control unit 300 and the information processing device 400 are connected to each other so as to be able to communicate with each other.

[0009] The three-dimensional modeling apparatus 100 includes a head unit 110 that generates and dispenses a plasticized material, a modeling stage 210 that serves as a base for a model, and a movement mechanism 230 that controls the dispense position of the plasticized material.

[0010] Under the control of the control unit 300, the head unit 110 ejects a plasticized material obtained by plasticizing a solid-state material onto the stage 210. The head unit 110 includes a material supply unit 20 that is a supply source of raw materials before being converted into a plasticized material, a plasticizing unit 30 that converts the raw materials into a plasticized material, and an ejection unit 60 that ejects the plasticized material.

[0011] The material supplying section 20 supplies the raw material MR to the plasticizing section 30. The material supplying section 20 is configured, for example, by a hopper that stores the raw material MR. The material supplying section 20 is connected to the plasticizing section 30 via a communication passage 22. The raw material MR is fed into the material supplying section 20 in the form of powder or pellets. As the raw material MR, for example, a resin material such as ABS (acrylonitrile butadiene styrene), PEEK (polyether ether ketone), or PP (polypropylene) is used.

[0012] The plasticizing section 30 plasticizes the raw material MR supplied from the material supply section 20 to generate a paste-like plasticized material that exhibits fluidity, and guides it to the discharge section 60. In this embodiment, "plasticization" is a concept that includes melting, and refers to changing from a solid to a fluid state. Specifically, in the case of a material that undergoes glass transition, plasticization refers to raising the temperature of the material to or above the glass transition point. In the case of a material that does not undergo glass transition, plasticization refers to raising the temperature of the material to or above the melting point.

[0013] The plasticizing section 30 includes a screw case 31, a drive motor 32, a screw 40, and a barrel 50. The screw 40 is also called a flat screw, a rotor, or a scroll. The barrel 50 is also called a screw facing portion.

[0014] The screw 40 is housed in the screw case 31. An upper surface 47 of the screw 40 is connected to the drive motor 32, and the screw 40 rotates in 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 300. Note that the screw 40 may be driven by the drive motor 32 via a reducer.

[0015] 2 is a perspective view showing a schematic configuration of the lower surface 48 side of the screw 40. In order to facilitate understanding of the technology, the screw 40 shown in FIG. 2 is shown in a state in which the positional relationship between the upper surface 47 and the lower surface 48 shown in FIG. 1 is reversed in the vertical direction. The screw 40 has a substantially cylindrical shape in which the length in the axial direction, which is the direction along the central axis, is smaller than the length in the direction perpendicular to the axial direction. The screw 40 is disposed so that the rotation axis RX, which is the center of rotation, is parallel to the Z direction.

[0016] A spiral groove 42 is formed on the lower surface 48 of the screw 40, which is a surface intersecting with the rotation axis RX. The communication passage 22 of the material supply unit 20 described above communicates with the groove 42 from the side surface of the screw 40. In this embodiment, three grooves 42 are formed, separated by a protruding rib portion 43. The number of grooves 42 is not limited to three, and may be one, or two or more. The groove 42 is not limited to a spiral shape, and may be a spiral shape or an involute curve shape, or may be a shape that extends in an arc from the center to the outer periphery.

[0017] 1, the lower surface 48 of the screw 40 faces the upper surface 52 of the barrel 50, and a space is formed between the groove portion 42 of the lower surface 48 of the screw 40 and the upper surface 52 of the barrel 50. Raw material MR is supplied from the material supply section 20 to this space between the screw 40 and the barrel 50 through the material inlet 44 shown in FIG.

[0018] A barrel heater 58 is embedded in the barrel 50 to heat the raw material MR supplied into the groove 42 of the rotating screw 40. A communication hole 56 is provided in the center of the barrel 50.

[0019] 3 is a schematic plan view showing the top surface 52 side of the barrel 50. A plurality of guide grooves 54 are formed on the top surface 52 of the barrel 50, which are connected to the communication holes 56 and extend in a spiral shape from the communication holes 56 toward the outer periphery. Note that one end of the guide grooves 54 does not have to be connected to the communication holes 56. Also, the guide grooves 54 can be omitted.

[0020] The raw material MR supplied into the groove 42 of the screw 40 flows along the groove 42 as the screw 40 rotates while being plasticized in the groove 42, and is guided to the center 46 of the screw 40 as a plasticized material. The paste-like plasticized material that has flowed into the center 46 and exhibits fluidity is supplied to the discharge section 60 through a communication hole 56 provided in the center of the barrel 50. Note that in the plasticized material, all types of substances constituting the plasticized material do not have to be plasticized. It is sufficient that the plasticized material is converted into a state having fluidity as a whole by plasticizing at least some types of substances constituting the plasticized material.

[0021] The discharge unit 60 in FIG. 1 includes a nozzle 61 for discharging the plasticized material, a flow path 65 for the plasticized material provided between the screw 40 and a nozzle opening 62, and a discharge control unit 77 for controlling the discharge of the plasticized material.

[0022] The nozzle 61 is connected to the communication hole 56 of the barrel 50 through a flow path 65. The nozzle 61 discharges the plasticized material produced in the plasticizing section 30 from a nozzle opening 62 at the tip toward the stage 210.

[0023] The discharge control unit 77 includes a discharge amount adjusting mechanism 70 that opens and closes the flow path 65, and a suction mechanism 75 that sucks in the plasticized material and temporarily stores it.

[0024] The discharge amount adjustment mechanism 70 is provided in the flow path 65, and changes the opening degree of the flow path 65 by rotating in the flow path 65. In this embodiment, the discharge amount adjustment mechanism 70 is configured by a valve. The discharge amount adjustment mechanism 70 is driven by a first drive unit 74 under the control of the control unit 300. The first drive unit 74 is configured by, for example, a stepping motor. The control unit 300 can adjust the flow rate of the plasticizing material flowing from the plasticizing unit 30 to the nozzle 61, that is, the discharge amount of the plasticizing material discharged from the nozzle 61, by controlling the rotation angle of the valve using the first drive unit 74. The discharge amount adjustment mechanism 70 can adjust the discharge amount of the plasticizing material and can control the on / off of the outflow of the plasticizing material.

[0025] The suction mechanism 75 includes a branch flow path 66 connected to the flow path 65, and a plunger 67 disposed in the branch flow path 66. The branch flow path 66 is connected to the flow path 65 between the discharge amount adjustment mechanism 70 and the nozzle opening 62. In the following, moving the plunger 67 in the branch flow path 66 away from the flow path 65 is referred to as "pulling the plunger 67," and moving the plunger 67 closer to the flow path 65 is referred to as "pushing the plunger 67." The plunger 67 of the suction mechanism 75 is driven by a second drive unit 76 under the control of the control unit 300. The second drive unit 76 is, for example, configured by a stepping motor, a rack-and-pinion mechanism that converts the rotational force of the stepping motor into translational motion of the plunger 67, or the like.

[0026] The control unit 300 controls the suction mechanism 75 to pull the plunger 67 when the discharge of the plasticized material from the nozzle 61 stops, thereby temporarily sucking the plasticized material in the flow path 65 into the branch flow path 66. This makes it possible to suppress the tailing phenomenon in which the plasticized material hangs down like a string from the nozzle opening 62.

[0027] The stage 210 is disposed at a position facing the nozzle opening 62 of the nozzle 61. In the first embodiment, the modeling 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. The stage 210 is provided with a stage heater 212 for preventing the plasticized material discharged onto the stage 210 from being suddenly cooled. The stage heater 212 is controlled by the control unit 300.

[0028] The moving mechanism 230 changes the relative position between the stage 210 and the nozzle 61 under the control of the control unit 300. In this embodiment, the position of the nozzle 61 is fixed, and the moving mechanism 230 moves the stage 210. The moving 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, by the driving forces of three motors. In this specification, unless otherwise specified, the movement of the nozzle 61 means the movement of the nozzle 61 and the discharge unit 60 relative to the stage 210. The range of the movement speed of the nozzle 61 by the moving mechanism 230 is set within a predetermined speed range.

[0029] 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. Also, 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.

[0030] 1 shows only one head unit 110, the three-dimensional modeling apparatus 100 may include multiple head units 110. By including multiple head units 110, different types of plasticizing materials can be discharged from each head unit 110. Therefore, for example, the main body of a modeled object and a support structure that supports the modeled object can be modeled using different types of plasticizing materials.

[0031] The control unit 300 is a control device that controls the overall operation of the three-dimensional modeling apparatus 100. The control unit 300 is configured by a computer including one or more processors 310, a storage device 320 including a main storage device and an auxiliary storage device, and an input / output interface that inputs and outputs signals to and from the outside. The processor 310 executes a program stored in the storage device 320 to control the plasticizing unit 30 and the moving mechanism 230 in accordance with modeling data acquired from the information processing device 400, thereby modeling a model on the stage 210. Note that the control unit 300 may be realized by a combination of circuits instead of being configured by a computer.

[0032] 4 is an explanatory diagram showing a schematic diagram of the three-dimensional modeling apparatus 100 modeling a modeled object. In the three-dimensional modeling apparatus 100, as described above, the raw material MR in a solid state is plasticized to generate the plasticized material MM. The control unit 300 discharges the plasticized material MM from the nozzle 61 while changing the position of the nozzle 61 relative to the stage 210 in a direction along the modeling surface 211 of the stage 210, while maintaining the distance between the modeling surface 211 of the stage 210 and the nozzle 61. The plasticized material MM discharged from the nozzle 61 is continuously deposited in the moving direction of the nozzle 61. The distance between the modeling surface 211 of the stage 210 and the nozzle 61 is also called the vertical distance.

[0033] The control unit 300 forms layers ML by repeatedly moving the nozzle 61. After forming one layer ML, the control unit 300 moves the position of the nozzle 61 relative to the stage 210 in the Z direction, which is the stacking direction. Then, a further layer ML is stacked on the layer ML that has been formed so far, thereby forming a modeled object.

[0034] The control unit 300 may temporarily suspend the discharge of the plasticizing material from the nozzle 61, for example, when the nozzle 61 moves in the Z direction after one layer ML is completed, or when there are multiple independent modeling portions in each layer. In this case, the control unit 300 may, for example, close the flow path 65 using the discharge amount adjustment mechanism 70 to stop the discharge of the plasticizing material MM from the nozzle opening 62, and temporarily suck the plasticizing material in the nozzle 61 using the suction mechanism 75. In addition, the control unit 300 may, for example, change the position of the nozzle 61, and then open the flow path 65 using the discharge amount adjustment mechanism 70 while discharging the plasticizing material in the suction mechanism 75, thereby resuming the deposition of the plasticizing material MM from the changed position of the nozzle 61.

[0035] 5 is an explanatory diagram showing a schematic configuration of the information processing device 400. The information processing device 400 is configured as a computer in which a CPU 410, a memory 420, a storage device 430, a communication interface 440, and an input / output interface 450 are interconnected via a bus 460. An input device 470 such as a keyboard or a mouse, and a display unit 480 such as a liquid crystal display are connected to the input / output interface 450. The information processing device 400 is connected to the control unit 300 of the three-dimensional printing apparatus 100 via the communication interface 440.

[0036] The CPU 410 executes a program stored in the storage device 430 to function as a data generation unit 411 .

[0037] The data generating unit 411 generates modeling data. The modeling data is data that represents information on the movement path of the nozzle 61 relative to the stage 210, the movement speed of the nozzle 61, the amount of plasticizing material discharged from the nozzle 61, the rotation speed of the screw 40, and the like. The data generating unit 411 reads shape data that represents the shape of a three-dimensional object created using three-dimensional CAD software or three-dimensional CG software, and divides the shape of the three-dimensional object into layers of a predetermined thickness. As the shape data, data in STL format, AMF format, or the like is used. The data generating unit 411 generates modeling data by determining the movement path of the nozzle 61 and the amount of plasticizing material so as to fill each divided layer with the plasticizing material. The modeling data is represented by G code, M code, or the like.

[0038] 6 is a flowchart of the modeling data generation process executed by the data generation unit 411. The modeling data generation process is a process for generating modeling data to be used for modeling a three-dimensional object prior to modeling the three-dimensional object. In step S10, the data generation unit 411 acquires three-dimensional data representing the shape of the three-dimensional object. The data generation unit 411 acquires three-dimensional data such as three-dimensional CAD data from an external source, for example, via a network or a recording medium.

[0039] In step S12, the data generator 411 analyzes the three-dimensional data acquired in step S10, and generates layer data by slicing the three-dimensional object into a plurality of layers along the XY plane. The slice interval is set according to the layer pitch.

[0040] In step S14, the data generating unit 411 generates modeling data using the layer data, and ends this processing routine. The modeling data includes path information indicating the movement path of the discharge unit 60, discharge amount information indicating the discharge amount of the plasticizing material on each movement path, and control information for controlling the discharge unit 60, the plasticizing unit 30, the movement mechanism 230, etc.

[0041] Fig. 7 is a diagram for explaining path information of the modeling data. The path information of the modeling data will be explained by taking as an example a case where the movement path indicated by the path information of the modeling data is the movement path shown in Fig. 7. Fig. 7 is a schematic diagram of one layer modeled by the modeling data as viewed in the Z direction.

[0042] The modeling data shown in FIG. 7 includes three modeling parts MA: a first modeling part MA1, a second modeling part MA2, and a third modeling part MA3. The solid lines shown in each modeling part MA indicate discharge paths, which are paths along which the nozzle 61 moves while discharging the plasticizing material from the nozzle opening 62. The dashed lines shown in each modeling part MA indicate the contours of linear objects formed when the nozzle 61 moves along the paths. The width of the linear object is also referred to as the line width LW. The dashed lines shown in FIG. 7 indicate non-discharge paths NR, which are paths along which the nozzle 61 moves after stopping the discharge of the plasticizing material from the nozzle opening 62. The non-discharge paths NR include a first non-discharge path NR1 and a second non-discharge path NR2. The distance of the non-discharge paths NR is also referred to as the movement distance.

[0043] The first modeling portion MA1 is modeled by moving the nozzle 61 from the first discharge start position SP1 to the first discharge stop position EP1 while discharging the plasticizing material from the nozzle opening 62. Then, the discharge of the plasticizing material from the nozzle opening 62 is stopped, and the nozzle 61 moves from the first discharge stop position EP1 to the second discharge start position SP2 along the first non-discharge path NR1 shown by the dashed line. Then, the nozzle 61 moves from the second discharge start position SP2 to the second discharge stop position EP2 while discharging the plasticizing material from the nozzle opening 62. This forms the second modeling portion MA2. Then, the discharge of the plasticizing material from the nozzle opening 62 is stopped, and the nozzle 61 moves from the second discharge stop position EP2 to the third discharge start position SP3 along the second non-discharge path NR2 shown by the dashed line. Then, the nozzle 61 moves from the third discharge start position SP3 to the third discharge stop position EP3 while discharging the plasticizing material from the nozzle opening 62. In this way, the third modeling portion MA3 is modeled. The above-described paths are set by path information included in the modeling data.

[0044] The first discharge stop position EP1, the second discharge stop position EP2, and the third discharge stop position EP3 are positions where discharge from the nozzle opening 62 stops, and are therefore also referred to as discharge stop positions. Among the first discharge start position SP1, the second discharge start position SP2, and the third discharge start position SP3, the second discharge start position SP2 and the third discharge start position SP3 are positions where discharge from the nozzle opening 62 resumes, and are therefore also referred to as discharge restart positions. In detail, the discharge stop position is a position where the opening of the discharge amount adjustment mechanism 70 is set to 0%. The discharge restart position is a position where the change in the opening of the discharge amount adjustment mechanism 70 begins. It is noted that it takes about 20 ms from when the change in the opening of the discharge amount adjustment mechanism 70 begins until the opening reaches 100%.

[0045] As described above, the shaping data includes control information in addition to the path information. The control information includes information on the movement speed of each of the discharge path and the non-discharge path NR. The movement speed is set for each of the discharge path and the non-discharge path NR. Furthermore, the movement speed is set independently for each movement path, specifically, the first non-discharge path NR1 and the second non-discharge path NR2.

[0046] In the present embodiment, when the nozzle 61 moves while the discharge of the plasticizing material is stopped, the flow path 65 is closed by the discharge amount adjustment mechanism 70, and the rotation speed of the screw 40 is reduced to 0 rpm. That is, the rotation of the screw 40 is stopped. Therefore, the pressure in the flow path 65 upstream of the discharge amount adjustment mechanism 70 decreases with time. FIG. 8 is a graph showing the relationship between time and pressure. The horizontal axis of FIG. 8 is time. The vertical axis of FIG. 8 is pressure, specifically, the discharge pressure, which is the pressure in the flow path 65 upstream of the discharge amount adjustment mechanism 70 and the pressure near the discharge amount adjustment mechanism 70. As shown in FIG. 8, the discharge pressure during the discharge period during which the plasticizing material is discharged from the nozzle opening 62 is adjusted to be maintained approximately constant. On the other hand, the discharge pressure during the non-discharge period during which the discharge of the plasticizing material from the nozzle opening 62 is stopped decreases at an approximately constant rate of decrease in accordance with the decrease in the pressure in the flow path 65 upstream of the discharge amount adjustment mechanism 70. The decrease rate is the amount of pressure reduction per unit time.

[0047] As shown in FIG. 8, during the non-discharge period, the pressure in the flow path 65 upstream of the discharge amount adjustment mechanism 70 decreases at a substantially constant rate, so that the discharge pressure at the time of resuming discharge changes depending on the length of the non-discharge period. If the discharge pressure varies, the line width LW at the discharge restart position may vary, and the modeling accuracy may decrease. In detail, as shown by the dashed line in FIG. 8, when the non-discharge period is short, the discharge pressure at the time of resuming discharge is higher than that shown by the solid line. In this way, if there is a difference in the time of the non-discharge period, the line width LW may vary, and the modeling quality may decrease. Therefore, the modeling data according to this embodiment is designed to reduce the variation in the time of the non-discharge period. Specifically, in this embodiment, the control information of the modeling data is created so that the time of the non-discharge period is constant regardless of the distance of the non-discharge path NR.

[0048] 6, the movement speed of the nozzle 61 in the non-ejection path NR is determined according to the movement distance from the ejection stop position to the ejection restart position. Specifically, the movement speed is determined so that the difference between a first movement time, which is the movement time in a first case in which the movement distance from the ejection stop position to the ejection restart position is a first distance, and a second movement time, which is the movement time in a second case in which the movement distance from the ejection stop position to the ejection restart position is a second distance shorter than the first distance, falls within a predetermined range. In this embodiment, the speed in the non-ejection path NR is determined so that the first movement time is equal to the second movement time.

[0049] FIG. 9 is a graph showing the relationship between the moving distance, which is the distance of the non-ejection path NR, and the moving speed, and the relationship between the moving distance and the moving time. In step S14 shown in FIG. 6, the moving speed of the non-ejection path NR is determined using the relational expression between the moving distance and the moving speed shown by the solid line in FIG. 9. As shown in FIG. 9, in the relational expression between the moving distance and the moving speed, the moving speed is proportional to the moving distance, and the proportionality constant is a positive value. As a result, as shown by the dashed line in FIG. 9, the moving time during the non-ejection period is set to a constant value regardless of the length of the moving distance. Therefore, even if the modeling data includes multiple non-ejection paths NR and the distances of each non-ejection path NR are different from each other, the moving time is set to a constant value, so that the variation in the discharge pressure when the discharge is resumed is suppressed. Therefore, the modeling quality of the modeled object can be improved. Furthermore, in this embodiment, the moving speed when moving the non-ejection path NR with the longest distance among the multiple non-ejection paths included in the modeling data is set to the largest speed in the speed range. This makes it possible to shorten the total time required for the movement of the non-discharge path NR, which has the longest distance, compared to when the movement speed is set to a speed lower than the highest speed in the speed range. This makes it possible to suppress a decrease in manufacturing efficiency. Note that the total time required for the movement of the non-discharge path NR refers to the total time for all steps of the modeling process for modeling a three-dimensional object.

[0050] The method of determining the moving speed is not limited to the method using the relational expression. In another embodiment, the data generator 411 may determine the moving speed using, for example, a table showing the relationship between the moving distance and the moving speed.

[0051] Fig. 10 is a flowchart of the modeling process executed by the control unit 300. The modeling process is a process executed by the control unit 300 using the modeling data generated in the modeling data generation process shown in Fig. 5. By performing the modeling process together with the first step of plasticizing a material to generate a plasticized material and sending the plasticized material toward the nozzle opening 62 of the nozzle 61, a manufacturing method for a three-dimensional object in which a three-dimensional object is formed by stacking layers is realized.

[0052] In step S20 as an acquisition step, the control unit 300 acquires shaping data. The control unit 300 reads shaping data for one layer among the multiple layers constituting the three-dimensional object from the acquired shaping data. In this embodiment, the control unit 300 first reads shaping data for the layer located at the bottom among the multiple layers constituting the three-dimensional object.

[0053] In step S22 as the second process, the control unit 300 forms a layer on the stage 210 by moving the nozzle 61 relative to the stage 210 while discharging the plasticized material from the nozzle opening 62. In detail, the control unit 300 moves the nozzle 61 to a discharge start position where the initial modeling of the layer starts, and then moves the nozzle 61 from the discharge start position to a discharge stop position. As a result, the plasticized material is discharged onto the stage 210 along the discharge path.

[0054] In step S24, the control unit 300 judges whether the modeling of the layer is completed. If it is judged in step S24 that the modeling of the layer is not completed, the control unit 300 stops the discharge of the plasticizing material from the nozzle opening 62 and moves the nozzle relatively from the discharge stop position to the discharge restart position in step S26 as a third process. In detail, in step S22, the control unit 300 adjusts the opening area of ​​the discharge amount adjustment mechanism 70 to stop the discharge of the plasticizing material from the nozzle opening 62 and reduce the rotation speed of the screw 40 to 0 rpm. In addition, in step S26, the control unit 300 performs a first control to move the nozzle 61 relatively to the stage 210 according to the moving speed included in the modeling data. Furthermore, in this embodiment, as the first control, a speed control is performed to set the moving speed to be larger as the moving distance from the discharge stop position to the discharge restart position becomes longer. Therefore, it is possible to suppress the variation in the discharge pressure when the discharge is resumed in the next step S22, and to suppress the variation in the discharge amount when the discharge is resumed.

[0055] After performing step S26, the control unit 300 returns the process to step S22 to model the next movement path.

[0056] When it is determined in step S24 that the modeling of the layer has been completed, the control unit 300 determines in step S28 whether the modeling of all layers has been completed. When it is determined that the modeling of all layers has not been completed, the control unit 300 moves the nozzle 61 to the discharge start position of the next layer in step S30 without discharging the plasticized material from the nozzle opening 62, in order to model the next layer. After performing step S30, the control unit 300 returns the process to step S22.

[0057] In step S28, if it is determined that modeling of all layers has been completed, the control unit 300 ends this processing routine.

[0058] According to the first embodiment described above, a three-dimensional object is formed by performing the first step, step S22 as the second step, and step S26 as the third step. In step S26, a first control is performed to control the position of the nozzle 61 so that the difference between the movement time in the first case where the movement distance from the discharge stop position to the discharge restart position is a first distance and the movement time in the second case where the movement distance is a second distance shorter than the first distance falls within a predetermined range. As a result, even if the movement distance from the discharge stop position to the discharge restart position is not constant, the movement time from the discharge stop position to the discharge restart position is controlled to fall within a predetermined range, so that the variation in pressure in the flow path 65 upstream of the discharge amount adjustment mechanism 70 can be suppressed. Therefore, the variation in the discharge amount at the time of discharge restart is suppressed, and the deterioration of the modeling accuracy of the object can be suppressed.

[0059] Furthermore, in step S26, the movement of the nozzle 61 is controlled so that the difference between a first movement time, which is the movement time when the distance of the non-ejection path NR is a first distance, and a second movement time, which is the movement time when the distance of the non-ejection path NR is a second distance shorter than the first distance, becomes zero, that is, so that the first movement time becomes equal to the second movement time. Therefore, since the movement time of the non-ejection path NR can be kept constant, the effect of suppressing the variation in pressure in the flow path 65 upstream of the discharge amount adjustment mechanism 70 can be improved.

[0060] In step S26, a speed control is performed as the first control, in which the longer the moving distance, which is the distance of the non-ejection path NR, the faster the moving speed is. Thus, by adjusting the moving speed, the moving time of the non-ejection path NR can be made constant. In order to adjust the moving time, it is not necessary to perform complex calculations to create the modeling data for the non-ejection path NR having a short distance, compared to when the moving path is changed so that the path length of the moving path of the nozzle 61 is increased, so that an increase in the calculation load for creating the modeling data can be suppressed. As a specific example of changing the moving path so that the path length of the moving path of the nozzle 61 is increased, the moving path can be set to a path along a curve connecting the ejection stop position and the ejection restart position, rather than a straight line connecting the ejection stop position and the ejection restart position.

[0061] Furthermore, the moving speed of the non-discharge path NR with the longest distance among the multiple non-discharge paths NR included in the modeling data is set to the highest speed within the speed range. Therefore, the total time required for moving the non-discharge path NR in the modeling process for modeling a three-dimensional object can be shortened compared to when the moving speed of the non-discharge path NR with the longest distance is set to a speed lower than the highest speed within the speed range. Therefore, a decrease in manufacturing efficiency can be suppressed.

[0062] Furthermore, in step S22, the rotation speed of the screw 40 is reduced to 0 rpm, that is, the rotation of the screw 40 is stopped. This makes it possible to prevent a pressure rise in the flow path 65 upstream of the discharge amount adjustment mechanism 70 during the movement time, and to prevent the line width LW at the time discharge is resumed from being significantly thicker than the target width.

[0063] B. Second embodiment: In the first embodiment, the first control is a speed control that adjusts the moving speed in the non-discharge path NR in order to make the moving time from the discharge stop position to the discharge restart position constant regardless of the distance. In the second embodiment, the first control is a first-stage control and a second-stage control that move the nozzle 61 in the Z direction, and a third-stage control that moves the nozzle 61 from the discharge stop position to the discharge restart position. As a result, similar to the speed control, the moving time from the discharge stop position to the discharge restart position is adjusted to a constant value. The same structures and processing steps as those in the first embodiment are denoted by the same reference numerals, and detailed explanations are omitted as appropriate.

[0064] FIG. 11 is a diagram for explaining the movement of the nozzle 61 of the non-ejection path NR in this embodiment. The horizontal axis of the graph in the upper part of FIG. 11 is time, and the vertical axis is the movement distance of the nozzle 61 in the Z direction. The horizontal axis of the graph in the lower part of FIG. 11 is time, and the vertical axis is the movement distance of the nozzle 61 in the XY plane. The two graphs in FIG. 11 are aligned so that the time axes of the graphs correspond to the elapsed time from time t0. At time t0 in FIG. 11, the nozzle 61 is located at the ejection stop position. At time t2 in FIG. 11, the nozzle 61 is located at the ejection restart position. The distance between the nozzle 61 and the stage 210 at the ejection stop position is a first vertical distance LZ1. Here, the distance between the nozzle 61 and the stage 210 is specifically the distance between the modeling surface 211 of the stage 210 and the nozzle 61. The characteristic line indicated by the dashed line in FIG. 11 is a characteristic line when the movement distance is the first distance L1. The characteristic line shown by a solid line in FIG. 11 is a characteristic line when the movement distance is a second distance L2 that is shorter than the first distance L1.

[0065] 11, in the case where the movement path of the modeling data includes a first distance L1 and a second distance L2 shorter than the first distance L1 as the movement distance of the non-ejection path, when moving the second distance L2, a first stage control and a second stage control are performed to move the nozzle 61 in the Z direction at the ejection start position, and then a third stage control is performed to move the nozzle 61 in the XY plane direction. As a result, when the non-ejection path NR is short, the non-ejection period is longer than when only the third stage control is performed, and therefore the difference between the first movement time and the second movement time can be reduced.

[0066] The first stage control, the second stage control, and the third stage control will be described in detail with reference to FIG. 11. The first stage control and the second stage control are performed in the period from time t0 to time t1 in FIG. 11. In the first stage control, the nozzle 61 is moved in the Z direction so as to have a second vertical distance LZ2 that is longer than the first vertical distance LZ1. Then, in the second stage control, the nozzle 61 is moved in the Z direction from the position of the second vertical distance LZ2 to the position of the first vertical distance LZ1. The difference between the first vertical distance LZ1 and the second vertical distance LZ2 is, for example, about 0.5 mm. The temperature of the nozzle 61 is high enough to prevent the fluidity of the plasticizing material from being impaired. Therefore, by performing the first stage control, it is possible to reduce the possibility that the object already formed on the stage 210 will be deformed by the heat radiated from the nozzle 61.

[0067] After the first stage control and the second stage control are performed, the third stage control is performed from time t1 to time t2. In this embodiment, when the distance of the non-ejection path NR is the first distance L1, the nozzle 61 is moved toward the ejection restart position at the same moving speed from time t0 to time t2. In this embodiment, the moving speed from time t1 to time t2 when the distance of the non-ejection path NR is the second distance L2 is the same as the moving speed when the distance of the non-ejection path NR is the first distance L1. As shown in FIG. 11, in this embodiment, the control information of the modeling data is set so that each nozzle 61 is located at the ejection restart position at time t2 in both cases when the distance of the non-ejection path NR is the second distance L2 and when the distance of the non-ejection path NR is the first distance L1.

[0068] According to the second embodiment described above, when the distance of the non-ejection path NR is the second distance L2 that is shorter than the first distance L1, the first control includes a first stage control and a second stage control for moving the nozzle 61 in the Z direction, and a third stage control for moving the nozzle 61 along the XY plane. Therefore, it is possible to reduce the difference between the movement time when the distance of the non-ejection path NR is the first distance L1 and the movement time when the distance of the non-ejection path NR is the second distance L2.

[0069] C. Third embodiment: In the first embodiment, speed control is applied to the non-ejection paths for the entire modeling data. In the third embodiment, speed control is applied to part of the modeling data. The same structures and the same processing steps as those in the above embodiments are given the same reference numerals, and detailed descriptions are omitted as appropriate.

[0070] FIG. 12 is a diagram for explaining the shaping data, and is a diagram similar to FIG. 7. The shaping data shown in FIG. 12 includes three shaping parts MA: a first shaping part MA1, a second shaping part MA2, and a third shaping part MA3. The first shaping part MA1 and the second shaping part MA2 each include an outer shell region as a first shaping region and an inner region as a second shaping region. The third shaping part MA3 includes only the outer shell region as the first shaping region. In FIG. 12, the outer shell region is indicated by a thick line, and the inner region is indicated by a thick dashed line. The outer shell region is a region that forms the outer shell of the shaping part MA.

[0071] The outer shell region is a region that forms the outline of the modeled object. Therefore, if the modeling accuracy of the outer shell region is low, the modeling accuracy of the modeled object will also be low. Therefore, the modeling accuracy of the outer shell region is set according to the modeling accuracy of the modeled object. In contrast, since the inner region is a region inside the outer shell region, in this embodiment, the modeling accuracy of the inner region is set lower than the modeling accuracy of the outer shell region. Specifically, in this embodiment, the data generation unit 411 creates modeling data by adjusting the modeling accuracy of the inner region to be lower than the modeling accuracy of the outer shell region.

[0072] The outer shell region of the first modeling portion MA1 is formed by moving the nozzle 61 from the first discharge start position SP1 to the first discharge stop position EP1 while discharging the plasticized material from the nozzle opening 62. The inner region of the first modeling portion MA1 is formed by moving the nozzle 61 from the second discharge start position SP2 to the second discharge stop position EP2 while discharging the plasticized material from the nozzle opening 62. The outer shell region of the second modeling portion MA2 is formed by moving the nozzle 61 from the third discharge start position SP3 to the third discharge stop position EP3 while discharging the plasticized material from the nozzle opening 62. The inner region of the second modeling portion MA2 is formed by moving the nozzle 61 from the fourth discharge start position SP4 to the fourth discharge stop position EP4 while discharging the plasticized material from the nozzle opening 62. The third modeling portion MA3 is modeled by discharging the plasticizing material from the nozzle opening 62 while the nozzle 61 moves from the fifth discharging start position SP5 to the fifth discharging stop position EP5.

[0073] The modeling data includes four non-discharge paths NR: a first non-discharge path NR1, a second non-discharge path NR2, a third non-discharge path NR3, and a fourth non-discharge path NR4. The first non-discharge path NR1 is a path from the first discharge stop position EP1 to the second discharge start position SP2. The second non-discharge path NR2 is a path from the second discharge stop position EP2 to the third discharge start position SP3. The third non-discharge path NR3 is a path from the third discharge stop position EP3 to the fourth discharge start position SP4. The fourth non-discharge path NR4 is a path from the fourth discharge stop position EP4 to the fifth discharge start position SP5.

[0074] In this embodiment, the first control is performed when the discharge restart position is the modeling discharge start position of the outer shell region, and the second control is performed when the discharge restart position is the modeling discharge start position of the inner region, in which the shorter the moving distance from the discharge stop position to the discharge restart position, the shorter the moving time. In this embodiment, in the second control, the nozzle 61 is moved from the discharge stop position to the discharge restart position at a predetermined speed. Specifically, the third discharge start position SP3 as the discharge restart position is the modeling discharge start position of the outer shell region of the second modeling part MA2. The fifth discharge start position SP5 as the discharge restart position is the modeling discharge start position of the third modeling part MA3, which is the outer shell region. Therefore, the first control is performed for the second non-discharge path NR2 and the fourth non-discharge path NR4. Specifically, in this embodiment, as in the first embodiment, speed control is performed as the first control. That is, since the distance of the second non-discharge path NR2 is longer than the distance of the fourth non-discharge path NR4, the movement speed of the second non-discharge path NR2 is set to be greater than the movement speed of the fourth non-discharge path NR4. This reduces the difference between the discharge pressure at the third discharge start position SP3 and the discharge pressure at the fifth discharge start position SP5. Therefore, the difference between the discharge amount at the third discharge start position SP3 and the discharge amount at the fifth discharge start position SP5 is reduced, and it is possible to suppress a decrease in the modeling accuracy of the shaped object.

[0075] On the other hand, the second discharge start position SP2 as the discharge restart position is the modeling start position of the internal region of the second portion to be formed MA2. The fourth discharge start position SP4 as the discharge restart position is the modeling start position of the internal region of the second portion to be formed MA2. Therefore, the second control is performed on the first non-discharge path NR1 and the third non-discharge path NR3. Specifically, although the distance of the first non-discharge path NR1 is different from the distance of the third non-discharge path NR3, the moving speed of the first non-discharge path NR1 and the moving speed of the third non-discharge path NR3 are set to the same speed. Since the distance of the first non-discharge path NR1 is shorter than the distance of the third non-discharge path NR3, the moving time of the nozzle 61 of the first non-discharge path NR1 is shorter than the moving time of the nozzle 61 of the third non-discharge path NR3. In this embodiment, the moving speed of the first non-discharge path NR1 and the moving speed of the third non-discharge path NR3 are set to the largest speed in the speed range.

[0076] In the speed control, when the distance of the non-discharge path NR is the second distance L2 that is shorter than the first distance L1, the moving speed of the non-discharge path NR at the second distance L2 is set to a speed lower than the moving speed of the non-discharge path NR at the first distance L1. Therefore, the moving time of the non-discharge path NR at the second distance L2 is longer than when it moves at the moving speed of the non-discharge path NR at the first distance L1. Therefore, by limiting the portion to which the speed control is performed, it is possible to prevent the modeling time from becoming longer while maintaining the modeling accuracy of the modeled object.

[0077] According to the third embodiment described above, when the discharge restart position is the modeling start position of the outer shell region, the speed control is performed as the first control, and when the discharge restart position is the modeling start position of the inner region, the second control is performed instead of the first control, in which the shorter the moving distance, the shorter the moving time. This makes it possible to prevent the modeling time from becoming longer while maintaining the modeling accuracy, compared to the case where the first control is performed for all modeling regions.

[0078] D. Other embodiments: (D1) In the first embodiment, the speed in the non-ejection path NR is determined so that the first movement time is equal to the second movement time. Not limited to this, the first control may be performed so that the difference between the first movement time and the second movement time is within a predetermined range. The smaller the predetermined range, i.e., the difference between the first movement time and the second movement time, the smaller the variation in the ejection amount when ejection is resumed, which is preferable. The predetermined range is, for example, 10% of the first movement time. As in the first embodiment, if the first movement time is equal to the second movement time, the effect of suppressing the variation in the ejection amount when ejection is resumed is further improved, which is even more preferable.

[0079] (D2) In the first embodiment, as the first control, when the distance of the non-ejection path NR is the second distance L2, which is shorter than the first distance L1, a speed control is performed in which the moving speed of the non-ejection path NR having the second distance L2 is set to a speed lower than the moving speed of the non-ejection path NR having the first distance L1. As another embodiment, for example, when the distance of the moving path is the second distance L2, the moving path from the ejection stop position to the ejection restart position may be a path that is longer than the straight line distance, such as a curved line or a broken line connecting the ejection stop position and the ejection restart position. In this case, even if the moving speed of the non-ejection path NR having the second distance L2 is set to the same as the moving speed of the non-ejection path NR having the first distance L1, the moving distance becomes longer, so the moving time can be longer. Therefore, the difference between the first moving time and the second moving time can be reduced. Furthermore, when the distance of the movement path is the second distance L2, the movement time may be lengthened by providing a waiting time without movement at a position on the movement path from the ejection stop position to the ejection restart position.

[0080] (D3) In the second embodiment, the first stage control, the second stage control, and the third stage control are performed in this order. This is not limited to the above, and the control unit 300 may move the nozzle 61 in the Z direction after moving the nozzle 61 from the discharge stop position to the discharge restart position. That is, as the first control, the third stage control, the first stage control, and the second stage control may be performed in this order. Also, the control unit 300 may move the nozzle 61 in the XY plane direction in a state where the nozzle 61 has been moved to the second vertical distance LZ2, and then move the nozzle 61 to the first vertical distance LZ1. That is, as the first control, the first stage control, the third stage control, and the second stage control may be performed in this order. Note that the control of moving the nozzle 61 in the Z direction may be performed in order to avoid interference with a modeled object that has already been modeled on the stage 210. In the second embodiment, the moving distance from the discharge stop position to the discharge restart position is the first distance L1, and the nozzle 61 is not moved in the Z direction. In another embodiment, the nozzle 61 may be moved in the Z direction such that the movement distance from the discharge stop position to the discharge restart position is the first distance L1. In this case, the difference between the first movement time and the second movement time can be reduced by setting the time during which the nozzle 61 is positioned at the second vertical distance LZ2 in the second case in which the movement distance is the second distance L2 to be longer than the time during which the nozzle 61 is positioned at the second vertical distance LZ2 in the first case in which the movement distance is the first distance L1. In addition, in the second embodiment, the movement speed at which the nozzle 61 is moved in the XY plane direction from the discharge stop position to the discharge restart position is the same regardless of the movement distance from the discharge stop position to the discharge restart position, but the movement distances may be different from each other.

[0081] (D4) In the third embodiment, the first control is performed on the outer shell region as the first printing region, and the second control is performed on the inner region as the second printing region. Other embodiments of the second printing region include a region called a raft or a support. A raft is a printing region that functions as a base and is printed to fix a three-dimensional object in the process of being printed to the stage 210. A support is a region that is printed to support a three-dimensional object in the process of being printed. When the second printing region is a raft or a support, the first printing region is a target printing region. The raft and the support are separated from the target printing region after printing is completed. The printing accuracy of the raft and the support is set lower than the printing accuracy of the target printing region. Therefore, the first control is performed on the target printing region, and the second control is performed on the raft and the support, thereby achieving the same effect as the third embodiment.

[0082] (D5) In the first embodiment described above, in the non-discharge period when the flow path 65 is blocked by the discharge amount adjustment mechanism 70, the rotation speed of the screw 40 is reduced to 0 rpm. In other words, in the non-discharge period, the rotation of the screw 40 is stopped. This is not limiting, and in the non-discharge period, the rotation speed of the screw 40 may be greater than 0 rpm. By reducing at least the rotation speed of the screw 40 in the non-discharge period, the discharge amount adjustment mechanism 70 can suppress an increase in pressure in the upstream flow path 65.

[0083] In the third embodiment, the second control is performed in such a way that the nozzle 61 is moved from the discharge stop position to the discharge restart position at a predetermined speed. The nozzle 61 is accelerated in the moving direction from the state where it is stopped at the discharge stop position until it reaches the target speed. Therefore, if the distance from the discharge stop position to the discharge restart position is short, the nozzle 61 may reach the discharge restart position before the speed of the nozzle 61 reaches a steady state. Therefore, the second control may be performed in such a way that the nozzle 61 is moved from the discharge stop position to the discharge restart position with acceleration.

[0084] E. Other forms: The present disclosure is not limited to the above-mentioned embodiment, and can be realized in various configurations without departing from the spirit of the present disclosure. For example, the technical features of the embodiments corresponding to the technical features in each form described below can be appropriately replaced or combined in order to solve some or all of the above-mentioned problems or to achieve some or all of the above-mentioned effects. Furthermore, if a technical feature is not described as essential in this specification, it can be appropriately deleted.

[0085] (1) According to one aspect of the present disclosure, there is provided a method for manufacturing a three-dimensional object, which forms a three-dimensional object by stacking layers. This manufacturing method includes a first step of plasticizing a material to generate a plasticized material and sending the plasticized material toward a nozzle opening of a nozzle; a second step of forming a layer on the stage by moving the nozzle relative to a stage while ejecting the plasticized material from the nozzle opening; and a third step of stopping ejection of the plasticized material from the nozzle opening during a movement time during which the nozzle moves relatively from an ejection stop position at which ejection from the nozzle opening is stopped to an ejection resume position located in the same layer as the ejection stop position and at which ejection from the nozzle opening is resumed. In the third step, a first control is performed to stop ejection of the plasticized material from the nozzle opening by adjusting the opening area of ​​a flow path through which the plasticized material flows toward the nozzle opening, and to control the position of the nozzle so that the difference between a first movement time, which is the movement time in a first case in which a movement distance from the ejection stop position to the ejection resume position is a first distance, and a second movement time, which is the movement time in a second case in which the movement distance is a second distance shorter than the first distance, is within a predetermined range. According to this embodiment, even if the distance from the discharge stop position to the discharge restart position is not constant, the movement time is controlled to be within a predetermined range, so that the variation in pressure in the flow path upstream of the adjustment point of the opening area after the passage of the movement time can be suppressed, and therefore the variation in the discharge amount of the plasticizing material at the discharge restart position can be suppressed.

[0086] (2) In the above embodiment, the first movement time may be equal to the second movement time. According to this embodiment, the time during which the discharge of the plasticizing material from the nozzle opening is stopped can be made equal, thereby improving the effect of suppressing the variation in pressure in the flow path upstream of the adjustment point of the opening area.

[0087] (3) In the above embodiment, the first control may be a speed control that controls the nozzle movement speed in the first case to be faster than the nozzle movement speed in the second case. According to this embodiment, the difference between the first movement time and the second movement time can be reduced by adjusting the movement speed. Compared to a case in which the nozzle movement path is changed to increase the path length in order to adjust the movement time, an increase in calculation load can be suppressed.

[0088] (4) In the above embodiment, the first control may include a first stage control for moving the nozzle relative to the stage from a first vertical distance, which is a distance between the nozzle and the stage at the discharge stop position, to a second vertical distance longer than the first vertical distance, a second stage control for moving the nozzle relative to the stage from a position of the second vertical distance to a position of the first vertical distance, and a third stage control for moving the nozzle relative to the stage from the discharge stop position to the discharge restart position. According to this embodiment, by performing the first stage control and the second stage control in the second embodiment, the difference between the first movement time and the second movement time can be reduced.

[0089] (5) In the above embodiment, the method may further include a step of acquiring modeling data, the modeling data including a first modeling region and a second modeling region in which the modeling accuracy is set lower than that of the first modeling region, and the first control may be performed when the ejection resume position is the modeling start position of the first modeling region, and when the ejection resume position is the modeling start position of the second modeling region, the method may instead perform a second control in which the shorter the movement distance, the shorter the movement time becomes. According to this embodiment, by appropriately setting a predetermined speed, it is possible to prevent the modeling time from becoming longer while maintaining the modeling accuracy, compared to the case where the first control is performed for the entire range of the modeling data.

[0090] (6) In the above embodiment, the method further includes an acquisition step of acquiring modeling data in which a plurality of non-discharge paths are set, each of the plurality of non-discharge paths is a path from the discharge stop position to the discharge restart position, and the moving speed can be set within a predetermined speed range. In the speed control, when moving the non-discharge path having the longest distance among the plurality of non-discharge paths, the moving speed may be set to the highest speed in the speed range. According to this embodiment, the total time during which the discharge of the plasticizing material from the nozzle opening is stopped can be shortened compared to when the moving speed of the path having the longest distance, which moves after stopping the discharge of the plasticizing material from the nozzle opening, is set to a speed lower than the highest speed in the speed range. Therefore, a decrease in manufacturing efficiency can be suppressed.

[0091] (7) In the above embodiment, the first step may generate the plasticized material by supplying the material to a plasticizing section having a screw and a motor for rotating the screw, and the third step may perform either control to stop the rotation speed of the screw or control to reduce the rotation speed of the screw during the moving time. According to this embodiment, it is possible to suppress an increase in pressure in the flow path upstream from the adjustment point of the opening area, and to suppress the discharge amount at the time of resuming discharge from being significantly larger than the target amount.

[0092] The present disclosure is not limited to the above-mentioned three-dimensional modeling manufacturing method, but can be realized in various forms, such as a three-dimensional modeling device, a three-dimensional modeling system, a computer program, and a non-transitory tangible recording medium on which a computer program is recorded in a computer-readable manner. [Explanation of symbols]

[0093] 10...three-dimensional modeling system, 20...material supply section, 22...connecting passage, 30...plasticization section, 31...screw case, 32...driving motor, 40...screw, 42...groove section, 43...ridge section, 44...material inlet, 46...center section, 47...upper surface, 48...lower surface, 50...barrel, 52...upper surface, 54...guide groove, 56...connecting hole, 58...barrel heater, 60...discharge section, 61...nozzle, 62...nozzle opening, 65...flow path, 66...branched flow Path, 67... plunger, 70... discharge amount adjustment mechanism, 74... first drive unit, 75... suction mechanism, 76... second drive unit, 77... discharge control unit, 100... three-dimensional modeling device, 110... head unit, 210... stage, 211... modeling surface, 212... stage heater, 230... movement mechanism, 300... control unit, 310... processor, 320... storage device, 400... information processing device, 410... CPU, 411... data generation unit, 420... memory , 430...storage device, 440...communication interface, 450...input / output interface, 460...bus, 470...input device, 480...display unit, EP1...first discharge stop position, EP2...second discharge stop position, EP3...third discharge stop position, EP4...fourth discharge stop position, EP5...fifth discharge stop position, L1...first distance, L2...second distance, LW...line width, LZ1...first vertical distance, LZ2...second vertical distance, MA...modeling part , MA1...first printing part, MA2...second printing part, MA3...third printing part, ML...layer, MM...plasticized material, MR...raw material, NR...non-discharge route, NR1...first non-discharge route, NR2...second non-discharge route, NR3 ...Third non-discharge route, NR4...Fourth non-discharge route, RX...Rotary axis, SP1...First discharge start position, SP2...Second discharge start position, SP3...Third discharge start position, SP4...Fourth discharge start position, SP5...Fifth discharge start position

Claims

1. A method for manufacturing a three-dimensional object, which forms a three-dimensional object by stacking layers, comprising the steps of: a first step of plasticizing a material to form a plasticized material and directing the plasticized material toward a nozzle opening of a nozzle; a second step of discharging the plasticizing material from the nozzle opening while moving the nozzle relative to a stage to form a layer on the stage; a third step of stopping the discharge of the plasticizing material from the nozzle opening during a movement time during which the nozzle moves relatively to the stage from a discharge stop position, at which the discharge from the nozzle opening is stopped, to a discharge restart position, at which the discharge from the nozzle opening is restarted, the movement time being such that the nozzle moves relatively to the stage from a discharge stop position, at which the discharge from the nozzle opening is stopped, to a discharge restart position, at which the discharge from the nozzle opening is restarted, In the third step, Stopping the discharge of the plasticizing material from the nozzle opening by adjusting an opening area of ​​a flow path through which the plasticizing material flows toward the nozzle opening; performing a first control for controlling movement of the nozzle relative to the stage so that a difference between a first movement time, which is the movement time in a first case in which a movement distance, which is the distance from the discharge stop position to the discharge restart position, is a first distance, and a second movement time, which is the movement time in a second case in which the movement distance is a second distance shorter than the first distance, falls within a predetermined range; A method for manufacturing three-dimensional objects.

2. The method for producing a three-dimensional object according to claim 1, The method for manufacturing a three-dimensional object, wherein the first movement time is equal to the second movement time.

3. The method for producing a three-dimensional object according to claim 1 or 2, The method for manufacturing a three-dimensional object, wherein the first control is a speed control for controlling the moving speed of the nozzle in the first case to be faster than the moving speed in the second case.

4. The method for producing a three-dimensional object according to claim 1 or 2, As the first control, A method for manufacturing a three-dimensional object, comprising: a first stage control in which, in the second case, the nozzle is moved relative to the stage from a first vertical distance, which is the distance between the nozzle and the stage at the discharge stop position, to a second vertical distance longer than the first vertical distance; a second stage control in which the nozzle is moved relative to the stage from a position of the second vertical distance to a position of the first vertical distance; and a third stage control in which the nozzle is moved relative to the stage from the discharge stop position to the discharge resume position.

5. The method for producing a three-dimensional object according to claim 1 or 2, The method further includes the step of acquiring modeling data, the printing data includes a first printing area and a second printing area, the second printing area being set to a printing accuracy lower than the printing accuracy of the first printing area; A method for manufacturing a three-dimensional object, comprising: performing the first control when the discharge resume position is the modeling start position of the first modeling region; and performing a second control instead of the first control when the discharge resume position is the modeling start position of the second modeling region, in which the shorter the movement distance, the shorter the movement time.

6. The method for producing a three-dimensional object according to claim 3, An acquisition step of acquiring modeling data in which a plurality of non-ejection paths are set, Each of the plurality of non-ejection paths is a path from the ejection stop position to the ejection restart position, The moving speed can be set within a predetermined speed range; In the speed control, when moving a non-discharge path having the longest distance among the plurality of non-discharge paths, the moving speed is set to the highest speed within the speed range.

7. The method for producing a three-dimensional object according to claim 1, In the first step, the plasticized material is generated by supplying the material to a plasticizing section having a screw and a motor for rotating the screw; In the third step, the rotation speed of the screw is reduced during the movement time.

Images