Method for producing three-dimensionally shaped object

Abstract

Provided is a method for manufacturing a three-dimensionally shaped object, which is capable of suppressing variations in the discharge amount at the time of restart of discharge. A method for manufacturing a three-dimensionally shaped object comprises: a first step of plasticizing a material to generate a plasticized material, and conveying 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 the stage while discharging the plasticized material from the nozzle opening; and a third step in which the ejection of the plasticized material from the nozzle opening is stopped during a movement time during which the nozzle relatively moves from the ejection stop position to a restart ejection position located on the same layer as the ejection stop position, and in the third step, first control for controlling the movement of the nozzle is performed, and second control for controlling the ejection of the plasticized material from the nozzle opening is performed. The difference between a first movement time, which is a movement time in a first case where the distance from the discharge stop position to the restart discharge position is a first distance, and a second movement time, which is a movement time in a second case where the distance is a second distance shorter than the first distance, is within a predetermined range.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a three-dimensional object. Background Art

[0002] Patent Document 1 discloses a three-dimensional modeling device having a flow rate regulating mechanism capable of controlling the amount of molten material ejected from a nozzle. In the three-dimensional modeling device, a non-ejection control for stopping the ejection of material from the nozzle is performed by adjusting the rotation angle of a butterfly valve. The non-ejection control is performed when the nozzle position is changed while the molten material is not ejected from the nozzle.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2019-81263

[0004] However, in the process of molding a three-dimensional object, a plurality of non-ejection controls are performed, and there is a case where the period from the stop of ejection to the restart of ejection in each of the plurality of non-ejection controls is different from each other. In this case, the pressure in the flow path upstream of the butterfly valve is different for each non-ejection control, and sometimes the ejection amount when the ejection is restarted is different for each non-ejection control. Summary of the invention

[0005] According to one embodiment of the present disclosure, there is provided a three-dimensional modeling device that models a three-dimensional object by stacking layers. The manufacturing method comprises: a first step of plasticizing a material to generate a plasticized material, and conveying the plasticized material toward a nozzle opening of a nozzle; a second step of moving the nozzle relative to a stage while ejecting the plasticized material from the nozzle opening, thereby forming a layer on the stage; and a third step of stopping ejecting the plasticized material from the nozzle opening during a movement time when the nozzle moves relative to the stage from an ejection stop position where ejection from the nozzle opening is stopped to a re-start ejection position located at the same layer as the ejection stop position, and ejection from the nozzle opening is restarted, wherein in the third step, ejection of the plasticized material from the nozzle opening is stopped by adjusting an opening area of ​​a flow path through which the plasticized material flows toward the nozzle opening, and a first control of controlling the movement of the nozzle relative to the stage is performed so that a difference between a first case where a distance from the ejection stop position to the re-start ejection position is a first distance, i.e., a first moving time, and a second case where the moving distance is a second distance shorter than the first distance, i.e., a second moving time, is within a predetermined range. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 This is an explanatory diagram showing the schematic structure of a three-dimensional modeling system.

[0007] Figure 2 It is a perspective view showing a schematic structure of a screw.

[0008] Figure 3 It is a schematic top view of the cylinder.

[0009] Figure 4 This is an explanatory diagram schematically showing how a three-dimensional modeling device models a modeled object.

[0010] Figure 5 It is an explanatory diagram showing a schematic configuration of an information processing device.

[0011] Figure 6 This is a flowchart of the modeling data generation process.

[0012] Figure 7 This is a diagram for explaining modeling data.

[0013] Figure 8 It is a graph showing the relationship between time and pressure.

[0014] Fig. 9 It is a coordinate diagram showing the relationship between the moving distance and the moving speed, and the relationship between the moving distance and the moving time.

[0015] Fig.10 It is a flowchart of the modeling process.

[0016] Fig.11 It is a diagram for explaining the movement of the non-discharging path in the second embodiment.

[0017] Fig.12 It is a diagram for explaining formation data in the third embodiment.

[0018] Description of Reference Numerals

[0019] 10…3D molding system, 20…Material supply unit, 22…Connecting passage, 30…Plasticizing unit, 31…Screw housing, 32…Drive motor, 40…Screw, 42…Groove, 43…Ribbon, 44…Material inlet, 46…Central unit, 47…Upper surface, 48…Lower surface, 50…Barrel, 52…Upper surface, 54…Guide groove, 56…Connecting hole, 58…Barrel heater, 60…Ejection unit, 61…Nozzle, 62…Nozzle opening, 65…Flow path, 66…Branch flow path, 67…Column Plug, 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, 210 ... stage, 211 ... modeling surface, 212 ... stage heater, 230 ... moving mechanism, 300 ... control unit, 310 ... processor, 320 ... storage device, 400 ... information processing device, 410 ... CPU, 411 ... data generation unit, 420 ... memory, 430 ... storage device, 44 0...communication interface, 450...input / output interface, 460...bus, 470...input device, 480...display unit, EP1...first ejection stop position, EP2...second ejection stop position, EP3...third ejection stop position, EP4...fourth ejection stop position, EP5...fifth ejection stop position, L1...first distance, L2...second distance, LW...line width, LZ1...first vertical distance, LZ2...second vertical distance, MA...molding part, MA1...first molding part, MA2…the second molding part, MA3…the third molding part, ML…layer, MM…plasticized material, MR…raw material, NR…non-ejection path, NR1…the first non-ejection path, NR2…the second non-ejection path, NR3…the third non-ejection path, NR4…the fourth non-ejection path, RX…rotating axis, SP1…the first ejection start position, SP2…the second ejection start position, SP3…the third ejection start position, SP4…the fourth ejection start position, SP5…the fifth ejection start position. DETAILED DESCRIPTION

[0020] A. First Implementation Method:

[0021] Figure 1 1 is an explanatory diagram showing a schematic configuration of a three-dimensional modeling system 10 in the first embodiment. Figure 1 In the figure, arrows indicating mutually orthogonal X, Y, and Z directions are shown. The X direction and the Y direction are directions parallel to the horizontal plane, and the Z direction is a direction along the vertical upward direction. The arrows indicating the X, Y, and Z directions are also shown in the directions shown in the other figures. Figure 1The corresponding manner is appropriately illustrated. In the following description, when the direction is determined, the direction indicated by the arrow in each figure is set as "+", and the opposite direction is set as "-", and positive and negative figures are used in the direction mark. In the following, the +Z direction is also called "up" and the -Z direction is called "down".

[0022] The three-dimensional modeling system 10 includes a three-dimensional modeling device 100 and an information processing device 400. The three-dimensional modeling device 100 of this embodiment is a device for modeling a modeled object by extruding a material. The three-dimensional modeling device 100 includes a control unit 300 for controlling various parts of the three-dimensional modeling device 100. The control unit 300 and the information processing device 400 are connected in a manner that allows mutual communication.

[0023] The three-dimensional modeling device 100 includes: a head 110 for generating and ejecting a plasticized material; a modeling table 210 serving as a base for a modeled object; and a moving mechanism 230 for controlling the ejection position of the plasticized material.

[0024] The head 110 sprays the plasticized material after plasticizing the solid material onto the stage 210 under the control of the control unit 300. The head 110 includes: a material supply unit 20, which is a supply source of the raw material before being converted into the plasticized material; a plasticizing unit 30, which converts the raw material into the plasticized material; and a spraying unit 60, which sprays the plasticized material.

[0025] The material supply unit 20 supplies the raw material MR to the plasticizing unit 30. The material supply unit 20 is composed of, for example, a hopper for accommodating the raw material MR. The material supply unit 20 is connected to the plasticizing unit 30 via a communication path 22. The raw material MR is fed into the material supply unit 20 in the form of powder or pellets. As the raw material MR, for example, resin materials such as ABS (acrylonitrile-butadiene-styrene), PEEK (polyetheretherketone), and PP (polypropylene) can be used.

[0026] The plasticizing section 30 plasticizes the raw material MR supplied from the material supply section 20, generates a plasticized material in a paste state showing fluidity, and guides it to the ejection section 60. In the present embodiment, "plasticization" refers to a concept including melting, which is to change the state from a solid to a fluid state. Specifically, in the case of a material undergoing glass transition, plasticization refers to making the temperature of the material above the glass transition point. In the case of a material that does not undergo glass transition, plasticization refers to making the temperature of the material above the melting point.

[0027] The plasticizing part 30 has a screw housing 31, a driving motor 32, a screw 40, and a barrel 50. The screw 40 is also called a flat head screw, a rotor, or a roller. The barrel 50 is also called a screw facing part.

[0028] The screw 40 is accommodated in the screw housing 31. The upper surface 47 of the screw 40 is connected to the drive motor 32, and the screw 40 rotates in the screw housing 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. In addition, the screw 40 can also be driven by the drive motor 32 via a speed reducer.

[0029] Figure 2 It is a perspective view showing a schematic structure of the lower surface 48 side of the screw 40 . Figure 2 The screw 40 shown is shown in a state of being in the opposite direction in the vertical direction in order to facilitate the understanding of the technology. Figure 1 The positional relationship between the upper surface 47 and the lower surface 48 is shown. The screw 40 has a substantially cylindrical shape in which the length along the central axis, i.e., the axial direction, is smaller than the length in the direction perpendicular to the axial direction. The screw 40 is arranged so that the rotation axis RX, which is the rotation center, is parallel to the Z direction.

[0030] A spiral groove portion 42 is formed on the surface of the screw 40 that intersects the rotation axis RX, that is, the lower surface 48. The communication path 22 of the material supply portion 20 is connected to the groove portion 42 from the side of the screw 40. In the present embodiment, the groove portions 42 are separated by convex strips 43 to form three grooves. In addition, the number of groove portions 42 is not limited to three, and may be one, or may be more than two. The groove portion 42 is not limited to a spiral shape, and may be a spiral or an involute curve shape, or may be a shape extending in a manner of describing an arc from the central portion toward the periphery.

[0031] like Figure 1 As shown, 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 42 of the lower surface 48 of the screw 40 and the upper surface 52 of the barrel 50. Figure 2 The material inlet 44 shown supplies the raw material MR to the space between the screw 40 and the barrel 50 .

[0032] A cartridge heater 58 for heating the raw material MR supplied into the groove portion 42 of the rotating screw 40 is embedded in the cartridge 50. A communication hole 56 is provided at the center of the cartridge 50.

[0033] Figure 3 1 is a schematic top view showing the upper surface 52 side of the tube 50. A plurality of guide grooves 54 are formed on the upper surface 52 of the tube 50, and the plurality of guide grooves 54 are connected to the communicating hole 56 and extend in a spiral shape from the communicating hole 56 toward the periphery. In addition, one end of the guide groove 54 may not be connected to the communicating hole 56. In addition, the guide groove 54 may be omitted.

[0034] The raw material MR supplied to the groove portion 42 of the screw 40 is plasticized in the groove portion 42, and flows along the groove portion 42 by the rotation of the screw 40, and is guided to the central portion 46 of the screw 40 as a plasticized material. The plasticized material in a paste state showing fluidity that flows into the central portion 46 is supplied to the ejection portion 60 via the connecting hole 56 provided in the center of the cylinder 50. In addition, in the plasticized material, all kinds of substances constituting the plasticized material may not be plasticized. The plasticized material only needs to be converted into a state having fluidity as a whole by plasticizing at least a part of the substances constituting the plasticized material.

[0035] Figure 1 The ejection unit 60 includes: a nozzle 61 for ejecting a plasticized material; a flow path 65 for the plasticized material provided between the screw 40 and the nozzle opening 62; and an ejection control unit 77 for controlling the ejection of the plasticized material.

[0036] The nozzle 61 is connected to the communication hole 56 of the barrel 50 through the flow path 65. The nozzle 61 ejects the plasticized material generated in the plasticizing portion 30 toward the stage 210 from a nozzle opening 62 at the front end.

[0037] The discharge control unit 77 includes a discharge amount adjustment mechanism 70 for opening and closing the flow path 65 and a suction mechanism 75 for sucking the plasticized material and temporarily storing it.

[0038] The ejection amount adjustment mechanism 70 is disposed in the flow path 65, and changes the opening of the flow path 65 by rotating in the flow path 65. In the present embodiment, the ejection amount adjustment mechanism 70 is composed of a valve. The ejection 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 composed of, for example, a stepping motor. The control unit 300 can adjust the flow rate of the plasticized material flowing from the plasticizing unit 30 to the nozzle 61, that is, the ejection amount of the plasticized material ejected from the nozzle 61, by controlling the rotation angle of the valve using the first drive unit 74. The ejection amount adjustment mechanism 70 can adjust the ejection amount of the plasticized material, and can control the opening / closing of the outflow of the plasticized material.

[0039] 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 ejection amount adjustment mechanism 70 and the nozzle opening 62. Hereinafter, 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 in the branch flow path 66 close to the flow path 65 is referred to as "pushing the plunger 67". The plunger 67 of the suction mechanism 75 is driven by the second drive unit 76 under the control of the control unit 300. The second drive unit 76 is composed of, for example, a stepping motor, a rack and pinion mechanism that converts the rotational force of the stepping motor into a translational motion of the plunger 67, and the like.

[0040] The control unit 300 controls the suction mechanism 75 to pull the plunger 67 when stopping the ejection of the plasticized material from the nozzle 61, thereby temporarily sucking the plasticized material in the flow path 65 into the branch flow path 66. This can suppress the tailing phenomenon of the plasticized material hanging down from the nozzle opening 62 like a string.

[0041] The stage 210 is arranged at a position opposite to the nozzle opening 62 of the nozzle 61. In the first embodiment, the molding surface 211 of the stage 210 opposite to the nozzle opening 62 of the nozzle 61 is arranged in parallel to the X and Y directions, that is, the horizontal direction. The stage 210 includes a stage heater 212 for suppressing rapid cooling of the plasticized material ejected onto the stage 210. The stage heater 212 is controlled by the control unit 300.

[0042] 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 the present embodiment, the position of the nozzle 61 is fixed, and the moving mechanism 230 moves the stage 210. The moving mechanism 230 is composed of a three-axis positioner, which uses the driving force of three motors to move the stage 210 in the three-axis directions of the X, Y, and Z directions. In this specification, unless otherwise specified, the movement of the nozzle 61 refers to the relative movement of the nozzle 61 or the ejection unit 60 with respect to the stage 210. The range of the moving speed of the nozzle 61 based on the moving mechanism 230 is set within a predetermined speed range.

[0043] In other embodiments, instead of the configuration in which the stage 210 is moved by the moving mechanism 230, 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 adopted. In addition, a configuration in which the stage 210 is moved in the Z direction by the moving mechanism 230 and the nozzle 61 is moved in the X and Y directions, or a configuration in which the stage 210 is moved in the X and Y directions by the moving mechanism 230 and the nozzle 61 is moved in the Z direction may be adopted. Even in these configurations, the relative positional relationship between the nozzle 61 and the stage 210 can be changed.

[0044] Although in Figure 1 Only one head 110 is shown in the figure, but the three-dimensional modeling device 100 may also include a plurality of heads 110. By including a plurality of heads 110, different types of plasticized materials can be ejected from each head 110. Therefore, for example, different types of plasticized materials can be used to model the main body of the modeled object and the supporting structure that supports the modeled object.

[0045] The control unit 300 is a control device for controlling the overall operation of the three-dimensional modeling device 100. The control unit 300 is composed of a computer having one or more processors 310, a storage device 320 formed by a main storage device or an auxiliary storage device, and an input / output interface for inputting and outputting signals to and from the outside. The processor 310 controls the plasticizing unit 30 and the moving mechanism 230 according to the modeling data obtained from the information processing device 400 by executing the program stored in the storage device 320, and models the modeled object on the stage 210. In addition, the control unit 300 can also be realized by a configuration in which circuits are combined instead of being composed of a computer.

[0046] Figure 4 3D modeling apparatus 100 is an explanatory diagram schematically showing how a modeling object is modeled by three-dimensional modeling apparatus 100. In three-dimensional modeling apparatus 100, as described above, a raw material MR in a solid state is plasticized to generate a plasticized material MM. Control unit 300 sprays plasticized material MM from nozzle 61 while changing the position of nozzle 61 relative to stage 210 in the direction along modeling surface 211 of stage 210 while maintaining the distance between modeling surface 211 of stage 210 and nozzle 61. Plasticized material MM sprayed from nozzle 61 is continuously accumulated in the moving direction of nozzle 61. The distance between modeling surface 211 of stage 210 and nozzle 61 is also referred to as vertical distance.

[0047] The control unit 300 repeatedly moves the nozzle 61 to form the layer ML. After forming one layer ML, the control unit 300 moves the nozzle 61 relative to the stage 210 in the Z direction, which is the stacking direction. Then, a molded object is molded by stacking a further layer ML on the layer ML formed so far.

[0048] The control unit 300 may temporarily stop the ejection of the plasticized material from the nozzle 61, for example, when the nozzle 61 moves in the Z direction when one layer ML is completed or when there are multiple independent molding parts in each layer. In this case, the control unit 300 may close the flow path 65 through the ejection amount adjustment mechanism 70, stop ejecting the plasticized material MM from the nozzle opening 62, and temporarily suck the plasticized material in the nozzle 61 through the suction mechanism 75. In addition, after changing the position of the nozzle 61, the control unit 300 may discharge the plasticized material in the suction mechanism 75 and open the flow path 65 through the ejection amount adjustment mechanism 70, so as to restart the accumulation of the plasticized material MM from the changed position of the nozzle 61.

[0049] Figure 54 is an explanatory diagram showing a schematic configuration of an 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 mutually connected via a bus 460. An input device 470 such as a keyboard and 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 modeling apparatus 100 via the communication interface 440.

[0050] The CPU 410 functions as a data generating unit 411 by executing a program stored in the storage device 430 .

[0051] The data generation unit 411 generates modeling data. Modeling data refers to data indicating information related to the moving path of the nozzle 61 relative to the stage 210, the moving speed of the nozzle 61, the amount of plasticized material ejected from the nozzle 61, and the rotation speed of the screw 40. The data generation unit 411 reads shape data representing the shape of a three-dimensional modeled object created using three-dimensional CAD software or three-dimensional CG software, and divides the shape of the three-dimensional modeled object into layers of a specified thickness. As shape data, data in STL format or AMF format is used. The data generation unit 411 generates modeling data by determining the moving path of the nozzle 61 or the amount of plasticized material to fill each divided layer with plasticized material. Modeling data is represented by G code or M code, etc.

[0052] Figure 6 4 is a flowchart of the modeling data generation process performed by the data generation unit 411. The modeling data generation process is a process for generating modeling data for modeling a three-dimensional modeling object before modeling the three-dimensional modeling object. In step S10, the data generation unit 411 obtains three-dimensional data representing the shape of the three-dimensional modeling object. The data generation unit 411 obtains three-dimensional data such as three-dimensional CAD data from the outside through a network or a recording medium.

[0053] In step S12, the data generating unit 411 analyzes the three-dimensional data acquired in step S10, and generates layer data for slicing the three-dimensional object into a plurality of layers along the XY plane. The intervals for slicing are set according to the stacking pitch.

[0054] In step S14, the data generating unit 411 generates modeling data using the layer data, and the present processing routine ends. The modeling data includes path information indicating the moving path of the ejection unit 60, ejection amount information indicating the ejection amount of the plasticized material in each moving path, and control information for controlling the ejection unit 60, the plasticizing unit 30, the moving mechanism 230, and the like.

[0055] Figure 72 is a diagram for explaining the path information of the modeling data. The moving path indicated by the path information of the modeling data is shown as follows: Figure 7 The path information of the modeling data will be described based on the moving path shown. Figure 7 This is a schematic diagram of a layer formed by modeling data when viewed along the Z direction.

[0056] Figure 7 The modeling data shown includes three modeling parts MA, namely, a first modeling part MA1, a second modeling part MA2, and a third modeling part MA3. The solid line shown in each modeling part MA shows the moving path, i.e., the ejection path, along which the nozzle 61 moves while ejecting the plasticized material from the nozzle opening 62. The dotted line shown in each modeling part MA shows the outline of the linear modeling object formed when the nozzle 61 moves along the moving path. The width of the linear modeling object is also referred to as the line width LW. Figure 7 The dashed line shown shows the movement path of the nozzle 61 after stopping the ejection of the plasticized material from the nozzle opening 62, that is, the non-ejection path NR. The non-ejection path NR includes a first non-ejection path NR1 and a second non-ejection path NR2. The distance of the non-ejection path NR is also called the movement distance.

[0057] The first molding part MA1 is molded by moving the nozzle 61 from the first ejection start position SP1 to the first ejection stop position EP1 while ejecting the plasticized material from the nozzle opening 62. Thereafter, the ejection of the plasticized material from the nozzle opening 62 is stopped, and the nozzle 61 moves from the first ejection stop position EP1 to the second ejection start position SP2 along the first non-ejection path NR1 indicated by the single-dot chain line. Thereafter, the nozzle 61 moves from the second ejection start position SP2 to the second ejection stop position EP2 while ejecting the plasticized material from the nozzle opening 62. Thus, the second molding part MA2 is molded. Thereafter, the ejection of the plasticized material from the nozzle opening 62 is stopped, and the nozzle 61 moves from the second ejection stop position EP2 to the third ejection start position SP3 along the second non-ejection path NR2 indicated by the single-dot chain line. Thereafter, the nozzle 61 moves from the third ejection start position SP3 to the third ejection stop position EP3 while ejecting the plasticized material from the nozzle opening 62. Thus, the third molding part MA3 is molded. The path described above is set by the path information included in the molding data.

[0058] The first ejection stop position EP1, the second ejection stop position EP2, and the third ejection stop position EP3 are positions where ejection from the nozzle opening 62 is stopped, and therefore are also referred to as ejection stop positions. In addition, among the first ejection start position SP1, the second ejection start position SP2, and the third ejection start position SP3, the second ejection start position SP2 and the third ejection start position SP3 are positions where ejection from the nozzle opening 62 is restarted, and therefore are also referred to as restart ejection positions. In detail, the ejection stop position refers to a position where the opening of the ejection amount adjustment mechanism 70 is set to 0%. The restart ejection position refers to a position where the change in the opening of the ejection amount adjustment mechanism 70 starts. In addition, the time from the start of the change in the opening of the ejection amount adjustment mechanism 70 to the opening being 100% is about 20 ms.

[0059] As described above, the molding data includes control information in addition to the path information. The control information includes information on the movement speed of each of the ejection path and the non-ejection path NR. The movement speed is set for each of the ejection path and the non-ejection path NR. Moreover, the movement speed is set independently in each movement path, specifically, in the first non-ejection path NR1 and the second non-ejection path NR2.

[0060] However, in the present embodiment, when the ejection of the plasticized material is stopped and the nozzle 61 is moved, the flow path 65 is closed by the ejection 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 ejection amount adjustment mechanism 70 decreases with the passage of time. Figure 8 It is a graph showing the relationship between time and pressure. Figure 8 The horizontal axis is time. Figure 8 The vertical axis of is pressure, specifically, 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, that is, the discharge pressure. Figure 8 As shown in FIG. 1 , the ejection pressure during the period when the plasticized material is ejected from the nozzle opening 62, i.e., the ejection period, is adjusted to be maintained substantially constant. In contrast, the ejection pressure during the period when the plasticized material is stopped from being ejected from the nozzle opening 62, i.e., the non-ejection period, decreases at a substantially constant decreasing rate as the pressure in the flow path 65 upstream of the ejection amount adjustment mechanism 70 decreases. In addition, the decreasing rate refers to the amount of pressure reduction per unit time.

[0061] like Figure 8 As shown in FIG. 1 , during the non-ejection period, the pressure in the flow path 65 upstream of the ejection amount adjustment mechanism 70 decreases at a substantially constant rate of decrease. Therefore, the ejection pressure when the ejection is restarted varies according to the length of the non-ejection period. When the ejection pressure deviates, the line width LW at the ejection restart position deviates, and there is a concern that the molding accuracy may decrease. In detail, as described by Figure 8As shown by the dotted line, when the non-ejection period is short, the ejection pressure when the ejection starts again is higher than that shown by the solid line. In this way, if there is a difference in the time during the non-ejection period, the line width LW will deviate, and there is a concern that the molding quality will be reduced. Therefore, a method for reducing the deviation of the time during the non-ejection period is implemented for the molding data involved in this embodiment. Specifically, in this embodiment, regardless of the distance of the non-ejection path NR, the control information of the molding data is created in a manner that the time during the non-ejection period is fixed.

[0062] exist Figure 6 In step S14 shown in the figure, the moving speed of the nozzle 61 in the non-ejection path NR is determined according to the moving distance from the ejection stop position to the ejection restart position. Specifically, the moving speed is determined so that the difference between the moving time in the first case where the moving distance from the ejection stop position to the ejection restart position is a first distance, that is, the first moving time, and the moving time in the second case where the moving distance from the ejection stop position to the ejection restart position is a second distance shorter than the first distance, that is, the second moving time, is within a predetermined range. In the present embodiment, the speed in the non-ejection path NR is determined so that the first moving time is equal to the second moving time.

[0063] Fig. 9 : is a coordinate diagram showing the relationship between the moving distance as the distance of the non-discharging path NR and the moving speed, and the relationship between the moving distance and the moving time. Figure 6 In step S14 shown in FIG. Fig. 9 The moving speed of the non-ejection path NR is determined by the relationship between the moving distance and the moving speed shown by the solid line. Fig. 9 As shown in , the relationship between the moving distance and the moving speed is that the moving speed is proportional to the moving distance, and the proportional constant is a positive value. Fig. 9 As shown by the dotted line, the moving time during the non-ejection period does not depend on the length of the moving distance and is set to be fixed. Therefore, even if the modeling data includes a plurality of non-ejection paths NR and the distances of each non-ejection path NR are different from each other, the moving time is also set to be fixed, so that the deviation of the ejection pressure when the ejection starts again can be suppressed. Therefore, the modeling quality of the modeling object can be improved. Moreover, in the present embodiment, the moving speed when the non-ejection path NR with the longest distance among the plurality of non-ejection paths included in the modeling data moves is set to the maximum speed in the speed range. Thus, compared with the case where the moving speed when the non-ejection path NR with the longest distance moves is set to a speed smaller than the maximum speed in the speed range, the total time required for the movement of the non-ejection path NR can be shortened. Therefore, the decline in manufacturing efficiency can be suppressed. In addition, the total time required for the movement of the non-ejection path NR refers to the total time in all the modeling processes for modeling the three-dimensional modeling object.

[0064] In addition, the method of determining the moving speed is not limited to the method using the relational expression. As another embodiment, the data generating unit 411 may determine the moving speed using, for example, a table indicating the relationship between the moving distance and the moving speed.

[0065] Fig.10 is a flowchart of the shaping process executed by the control unit 300. The shaping process is performed using Figure 5 The modeling data generated in the modeling data generation process shown is a process executed by the control unit 300. By performing the modeling process together with the first step of plasticizing the material to generate the plasticized material and conveying the plasticized material toward the nozzle opening 62 of the nozzle 61, a method for manufacturing a three-dimensional modeled object by stacking layers can be realized.

[0066] In step S20 as the acquisition process, the control unit 300 acquires modeling data. Based on the acquired modeling data, the control unit 300 reads modeling data for one layer among the multiple layers constituting the three-dimensional modeling object. In the present embodiment, the control unit 300 first reads modeling data for the layer located at the bottom among the multiple layers constituting the three-dimensional modeling object.

[0067] In step S22 as the second process, the control unit 300 moves the nozzle 61 relative to the stage 210 while ejecting the plasticized material from the nozzle opening 62, thereby forming a layer on the stage 210. Specifically, the control unit 300 moves the nozzle 61 to the ejection start position for starting the initial formation of the layer, and then moves the nozzle 61 from the ejection start position to the ejection stop position. Thus, the plasticized material is ejected toward the stage 210 along the ejection path.

[0068] In step S24, the control unit 300 determines whether the molding of the layer has been completed. In step S24, if it is determined that the molding of the layer has not been completed, the control unit 300 stops ejecting the plasticized material from the nozzle opening 62 in step S26 as the third process, and relatively moves the nozzle from the ejection stop position to the ejection restart position. In detail, in step S22, the control unit 300 stops ejecting the plasticized material from the nozzle opening 62 by adjusting the opening area of ​​the ejection amount adjustment mechanism 70, and reduces the rotation speed of the screw 40 to 0 rpm. In addition, in step S26, the control unit 300 performs a first control to relatively move the nozzle 61 relative to the stage 210 according to the moving speed included in the molding data. Moreover, in this embodiment, as the first control, a speed control is performed in which the longer the moving distance from the ejection stop position to the ejection restart position is, the greater the moving speed is set. Therefore, the deviation of the ejection pressure when the ejection is restarted in the next step S22 can be suppressed, and the deviation of the ejection amount when the ejection is restarted can be suppressed.

[0069] After performing step S26 , the control unit 300 returns the process to step S22 in order to perform formation of the next movement path.

[0070] In step S24, if it is determined that the shaping of the layer is completed, the control unit 300 determines whether the shaping of the entire layer is completed in step S28. If it is determined that the shaping of the entire layer is not completed, the control unit 300 does not spray the plasticized material from the nozzle opening 62 in step S30 to perform shaping of the next layer, but moves the nozzle 61 to the spray start position of the next layer. After performing step S30, the control unit 300 returns the process to step S22.

[0071] In step S28, when it is determined that the formation of the entire layer has been completed, the control unit 300 ends the present processing routine.

[0072] According to the first embodiment described above, a three-dimensional object is molded by performing the first process, step S22 as the second process, and step S26 as the third process. In step S26, the first control of controlling the position of the nozzle 61 is performed so that the difference between the moving time in the first case where the moving distance from the ejection stop position to the ejection restart position is the first distance and the moving time in the case where the moving distance is the second distance shorter than the first distance is within a predetermined range. Thus, even if the moving distance from the ejection stop position to the ejection restart position is not fixed, since the moving time from the ejection stop position to the ejection restart position is controlled to be within a predetermined range, the deviation of the pressure in the flow path 65 upstream of the ejection amount adjustment mechanism 70 can be suppressed. Therefore, the deviation of the ejection amount when the ejection is restarted can be suppressed, and the decrease in the molding accuracy of the object can be suppressed.

[0073] In addition, in step S26, the movement of the nozzle 61 is controlled so that the difference between the movement time when the distance of the non-ejection path NR is the first distance, that is, the first movement time, and the movement time when the distance of the non-ejection path NR is the second distance shorter than the first distance, that is, the second movement time, is zero, that is, the first movement time and the second movement time are equal. Therefore, since the movement time of the non-ejection path NR can be fixed, the effect of suppressing the deviation of the pressure in the flow path 65 upstream of the ejection amount adjustment mechanism 70 can be improved.

[0074] In addition, in step S26, as the first control, speed control is performed such that the longer the moving distance as the distance of the non-ejection path NR is, the greater the moving speed is. Therefore, by adjusting the moving speed, the moving time of the non-ejection path NR can be fixed. In order to adjust the moving time, compared with the case where the moving path of the non-ejection path NR with a short distance is changed so that the path length of the moving path of the nozzle 61 becomes longer, there is no need to perform complex calculations for the creation of modeling data, so the increase in the calculation load for the creation of modeling data can be suppressed. As a specific example of changing the moving path in a manner that the path length of the moving path of the nozzle 61 becomes longer, it can be cited that the moving path is not set to a straight line connecting the ejection stop position and the ejection restart position, but to a path along a curve connecting the ejection stop position and the ejection restart position.

[0075] In addition, the moving speed of the non-ejection path NR with the longest distance among the plurality of non-ejection paths NR included in the modeling data is set to the maximum speed in the speed range. Therefore, compared with the case where the moving speed of the non-ejection path NR with the longest distance is set to a speed lower than the maximum speed in the speed range, the total time required for the movement of the non-ejection path NR in the modeling process of modeling the three-dimensional modeling object can be shortened. Therefore, the decline in manufacturing efficiency can be suppressed.

[0076] In addition, 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 can avoid the pressure rise in the flow path 65 upstream of the discharge amount adjustment mechanism 70 during the moving time, and can prevent the line width LW from being significantly wider than the target width when the discharge is restarted.

[0077] B. Second Implementation Method:

[0078] In the first embodiment, as the first control, in order to make the moving time from the ejection stop position to the ejection restart position fixed regardless of the distance, speed control is performed to adjust the moving speed in the non-ejection path NR. In the second embodiment, as the first control, the first stage control and the second stage control of moving the nozzle 61 in the Z direction, and the third stage control of moving the nozzle 61 from the ejection stop position to the ejection restart position are performed. Thus, as with the speed control, the moving time from the ejection stop position to the ejection restart position is adjusted to be fixed. The same reference numerals are given to the same structures and the same processing steps as those in the first embodiment, and detailed descriptions are appropriately omitted.

[0079] Fig.11 It is a diagram for explaining the movement of the nozzle 61 of the non-discharge path NR in this embodiment. Fig.11The horizontal axis of the upper coordinate graph is time, and the vertical axis is the moving distance of the nozzle 61 in the Z direction. Fig.11 The horizontal axis of the lower coordinate graph is time, and the vertical axis is the moving distance of the nozzle 61 on the XY plane. Fig.11 The time axes of the two coordinate graphs are aligned so that the elapsed time from time t0 is consistent. Fig.11 At time t0, the nozzle 61 is located at the ejection stop position. Fig.11 At time t2, the nozzle 61 is located at the spraying restart position. The distance between the nozzle 61 and the stage 210 at the spraying stop position is the first vertical distance LZ1. Here, the distance between the nozzle 61 and the stage 210 specifically refers to the distance between the molding surface 211 of the stage 210 and the nozzle 61. Fig.11 The characteristic line shown by the dotted line in FIG. 1 is the characteristic line when the moving distance is the first distance L1. Fig.11 The characteristic line indicated by the solid line is a characteristic line when the moving distance is the second distance L2 which is shorter than the first distance L1.

[0080] like Fig.11 As shown, when there is a non-discharging path in the moving path of the molding data, the moving distance is the first distance L1, and the second distance L2 shorter than the first distance L1, when the second distance L2 is moved, the first stage control and the second stage control of moving the nozzle 61 in the Z direction are performed at the ejection start position, and then the third stage control of moving the nozzle 61 in the XY plane direction is performed. Thus, when the non-discharging path NR is short, the time of the non-discharging period becomes longer than when only the third stage control is performed, so the difference between the first moving time and the second moving time can be reduced.

[0081] use Fig.11 The first stage control, the second stage control and the third stage control are described in detail. Fig.11 The first stage control and the second stage control are performed during the period from time t0 to time t1. In the first stage control, the nozzle 61 moves in the Z direction in a manner to become the second vertical distance LZ2 which is longer than the first vertical distance LZ1. Thereafter, in the second stage control, the nozzle 61 moves 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 not to impair the fluidity of the plasticized material. Therefore, by performing the first stage control, the possibility of deformation of the molded object already molded on the stage 210 due to the heat radiated from the nozzle 61 can be reduced.

[0082] 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 the present embodiment, when the distance of the non-ejection path NR is the first distance L1, from time t0 to time t2, the nozzle 61 moves toward the ejection restart position at the same moving speed. Then, in the present embodiment, when the distance of the non-ejection path NR is the second distance L2, the moving speed from time t1 to time t2 is the same as the moving speed when the distance of the non-ejection path NR is the first distance L1. Fig.11 As shown, in this embodiment, in any of the cases where the distance of the non-ejection path NR is the second distance L2 and the distance of the non-ejection path NR is the first distance L1, the control information of the molding data is set in such a way that each nozzle 61 is located at the restarting ejection position at time t2.

[0083] According to the second embodiment described above, as the first control, when the distance of the non-ejection path NR is the second distance L2 shorter than the first distance L1, the first stage control and the second stage control of moving the nozzle 61 in the Z direction and the third stage control of moving the nozzle 61 along the XY plane are performed. Therefore, the difference between the moving time when the distance of the non-ejection path NR is the first distance L1 and the moving time when the distance of the non-ejection path NR is the second distance L2 can be reduced.

[0084] C. Third Implementation Method:

[0085] In the first embodiment, speed control is applied to the non-discharge path for the entire molding data. In the third embodiment, speed control is partially applied to the molding data. The same reference numerals are given to the same structures and processing steps as those in the above embodiments, and detailed descriptions are omitted as appropriate.

[0086] Fig.12 is a diagram that illustrates the modeling data. Figure 7 Same picture. Fig.12 The modeling data shown includes three modeling parts MA, namely, the first modeling part MA1, the second modeling part MA2, and the third modeling part MA3. In addition, the first modeling part MA1 and the second modeling part MA2 include an outer shell area as a first modeling area and an inner area as a second modeling area. The third modeling part MA3 includes only the outer shell area as the first modeling area. Fig.12 In FIG. 1 , the outer shell region is shown by a bold line, and the inner region is shown by a bold dashed line. The outer shell region is a region forming the outer shell of the molding portion MA.

[0087] The shell region is a region that forms the outline of the object. Therefore, when the modeling accuracy of the shell region is low, the modeling accuracy of the object also becomes low. Therefore, the modeling accuracy of the shell region is set according to the modeling accuracy of the object. In contrast, the internal region is a region inside the shell region, so in this embodiment, the modeling accuracy of the internal region is set lower than the modeling accuracy of the shell region. Specifically, in this embodiment, the data generation unit 411 adjusts the modeling accuracy of the internal region to be lower than the modeling accuracy of the shell region, thereby creating modeling data.

[0088] The outer shell area of ​​the first molding portion MA1 is molded by moving the nozzle 61 from the first ejection start position SP1 to the first ejection stop position EP1 while ejecting the plasticized material from the nozzle opening 62. The inner area of ​​the first molding portion MA1 is molded by moving the nozzle 61 from the second ejection start position SP2 to the second ejection stop position EP2 while ejecting the plasticized material from the nozzle opening 62. The outer shell area of ​​the second molding portion MA2 is molded by moving the nozzle 61 from the third ejection start position SP3 to the third ejection stop position EP3 while ejecting the plasticized material from the nozzle opening 62. The inner area of ​​the second molding portion MA2 is molded by moving the nozzle 61 from the fourth ejection start position SP4 to the fourth ejection stop position EP4 while ejecting the plasticized material from the nozzle opening 62. The third molding portion MA3 is molded by moving the nozzle 61 from the fifth ejection start position SP5 to the fifth ejection stop position EP5 while ejecting the plasticized material from the nozzle opening 62.

[0089] The molding data includes four non-ejection paths NR, namely, a first non-ejection path NR1, a second non-ejection path NR2, a third non-ejection path NR3, and a fourth non-ejection path NR4. The first non-ejection path NR1 is a path from the first ejection stop position EP1 to the second ejection start position SP2. The second non-ejection path NR2 is a path from the second ejection stop position EP2 to the third ejection start position SP3. The third non-ejection path NR3 is a path from the third ejection stop position EP3 to the fourth ejection start position SP4. The fourth non-ejection path NR4 is a path from the fourth ejection stop position EP4 to the fifth ejection start position SP5.

[0090] In the present embodiment, the first control is performed when the ejection restart position is the molding ejection start position of the outer shell area, and the second control is performed so that the shorter the moving distance from the ejection stop position to the ejection restart position is, the shorter the moving time is. In the present embodiment, in the second control, the nozzle 61 moves from the ejection stop position to the ejection restart position at a predetermined speed. Specifically, the third ejection start position SP3 as the ejection restart position is the molding ejection start position of the outer shell area of ​​the second molding part MA2. The fifth ejection start position SP5 as the ejection restart position is the molding ejection start position of the third molding part MA3 as the outer shell area. Therefore, the first control is performed on the second non-ejection path NR2 and the fourth non-ejection path NR4. Specifically, in the present embodiment, speed control is performed as the first control as in the first embodiment. That is, since the distance of the second non-ejection path NR2 is longer than the distance of the fourth non-ejection path NR4, the moving speed of the second non-ejection path NR2 is set to be greater than the moving speed of the fourth non-ejection path NR4. As a result, the difference between the ejection pressure at the third ejection start position SP3 and the ejection pressure at the fifth ejection start position SP5 is reduced. Therefore, the difference between the ejection amount at the third ejection start position SP3 and the ejection amount at the fifth ejection start position SP5 is reduced, and the decrease in the molding accuracy of the molded object can be suppressed.

[0091] In contrast, the second ejection start position SP2, which is the ejection restart position, is the molding start position of the inner area of ​​the second molding part MA2. The fourth ejection start position SP4, which is the ejection restart position, is the molding start position of the inner area of ​​the second molding part MA2. Therefore, the first non-ejection path NR1 and the third non-ejection path NR3 are second controlled. Specifically, the distance of the first non-ejection path NR1 is different from the distance of the third non-ejection path NR3, but the moving speed of the first non-ejection path NR1 and the moving speed of the third non-ejection path NR3 are set to the same speed. Since the distance of the first non-ejection path NR1 is shorter than the distance of the third non-ejection path NR3, the moving time of the nozzle 61 of the first non-ejection path NR1 is shorter than the moving time of the nozzle 61 of the third non-ejection path NR3. In the present embodiment, the moving speed of the first non-ejection path NR1 and the moving speed of the third non-ejection path NR3 are set to the maximum speed in the speed range.

[0092] In the speed control, when the distance of the non-ejection path NR is the second distance L2 shorter than the first distance L1, the moving speed of the non-ejection path NR as the second distance L2 is set to a speed lower than the moving speed of the non-ejection path NR as the first distance L1. Therefore, the moving time of the non-ejection path NR as the second distance L2 is longer than the case where the non-ejection path NR moves at the moving speed of the non-ejection path NR as the first distance L1. Therefore, by limiting the portion where the speed control is performed, it is possible to maintain the molding accuracy of the molded object and suppress the molding time from being prolonged.

[0093] According to the third embodiment described above, when the ejection restart position is the molding start position of the outer shell area, the speed control is performed as the first control, and when the ejection restart position is the molding start position of the inner area, the second control is performed instead of the first control, in which the shorter the moving distance, the shorter the moving time. Thus, compared with the case where the first control is performed for all molding areas, it is possible to maintain molding accuracy and suppress the molding time from becoming longer.

[0094] D. Other implementation methods:

[0095] (D1) In the first embodiment described above, the speed in the non-ejection path NR is determined in such a way that the first moving time is equal to the second moving time. Without being limited to this, a first control may be performed so that the difference between the first moving time and the second moving time is within a predetermined range. The smaller the predetermined range, i.e., the difference between the first moving time and the second moving time, the smaller the deviation of the ejection amount when the ejection is restarted, and therefore it is preferred. The predetermined range is, for example, 10% of the first moving time. As in the first embodiment, when the first moving time is equal to the second moving time, the effect of suppressing the deviation of the ejection amount when the ejection is restarted is further improved, and therefore it is further preferred.

[0096] (D2) In the first embodiment described above, as the first control, when the distance of the non-ejection path NR is the second distance L2 shorter than the first distance L1, speed control is performed to set the moving speed of the non-ejection path NR as the second distance L2 to a speed smaller than the moving speed of the non-ejection path NR as 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 set to a path having a distance longer than the distance of a straight line such as a curve or a broken line 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. In this case, even when the moving speed of the non-ejection path NR as the second distance L2 is set to be the same as the moving speed of the non-ejection path NR as the first distance L1, the moving distance becomes longer, so the moving time can be extended. Therefore, the difference between the first moving time and the second moving time can be reduced. Furthermore, when the distance of the moving path is the second distance L2, the moving time may be extended by setting a waiting time without moving at a position on the moving path from the ejection stop position to the ejection restart position.

[0097] (D3) In the above-mentioned second embodiment, the first stage control, the second stage control, and the third stage control are performed in sequence. Not limited to this, the control unit 300 may move the nozzle 61 in the Z direction after moving the nozzle 61 from the ejection stop position to the ejection 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 sequence. In addition, the control unit 300 may move the nozzle 61 to the first vertical distance LZ1 after moving it in the XY plane direction in a state of moving the nozzle 61 to the second vertical distance LZ2. That is, as the first control, the first stage control, the third stage control, and the second stage control may be performed in sequence. In addition, in order to avoid interference with the molded object that has been molded on the stage 210, control is sometimes performed to move the nozzle 61 in the Z direction. In the above-mentioned second embodiment, when the moving distance from the ejection stop position to the ejection restart position is the first distance L1, the nozzle 61 is not moved in the Z direction. As another embodiment, the nozzle 61 may be moved in the Z direction when the moving distance from the ejection stop position to the ejection restart position is the first distance L1. In this case, by setting the time when the nozzle 61 in the second case where the moving distance is the second distance L2 is located at the second vertical distance LZ2 to be longer than the time when the nozzle 61 in the first case where the moving distance is the first distance L1 is located at the second vertical distance LZ2, the difference between the first moving time and the second moving time can be reduced. In addition, in the above-mentioned second embodiment, regardless of the moving distance from the ejection stop position to the ejection restart position, the moving speed of the nozzle 61 from the ejection stop position to the ejection restart position in the XY plane direction is the same, but the moving distances may be different from each other.

[0098] (D4) In the third embodiment described above, the first control is performed on the outer shell area as the first molding area, and the second control is performed on the inner area as the second molding area. As other embodiments of the second molding area, there is a region called a base or a support. The base refers to a molding area that functions as a pedestal, and is a region that is molded in order to fix the three-dimensional molding object in the middle of molding to the table 210. The support refers to a region that is molded in order to support the three-dimensional molding object in the middle of molding. In the case where the second molding area is the base or the support, the first molding area is the target molding area. In addition, the base and the support are separated from the target molding area after the molding is completed. The molding accuracy of the base or the support is set to be lower than the molding accuracy of the target molding area. Therefore, by performing the first control on the target molding area and performing the second control on the base or the support, the same effect as the third embodiment described above is achieved.

[0099] (D5) In the first embodiment, the rotation speed of the screw 40 is reduced to 0 rpm during the non-ejection period when the flow path 65 is closed by the ejection amount adjustment mechanism 70. That is, the rotation of the screw 40 stops during the non-ejection period. Without limitation to this, the screw 40 may also rotate at a speed greater than 0 rpm during the non-ejection period. During the non-ejection period, by at least reducing the rotation speed of the screw 40, the increase in pressure in the upstream flow path 65 can be suppressed by the ejection amount adjustment mechanism 70.

[0100] In the third embodiment, as the second control, the nozzle 61 is controlled to move from the ejection stop position to the ejection restart position at a predetermined speed. The nozzle 61 is accelerated in the moving direction from the state of being stopped at the ejection stop position until the target speed is reached. Therefore, in the case where the distance from the ejection stop position to the ejection restart position is very small, the ejection restart position may be reached before the speed of the nozzle 61 becomes stable. Therefore, as the second control, the nozzle 61 may be controlled to move from the ejection stop position to the ejection restart position at an accelerated speed.

[0101] E.Other methods:

[0102] The present disclosure is not limited to the above-mentioned embodiments, and can be implemented in various configurations within the scope of the main purpose. For example, in order to solve part or all of the above-mentioned problems, or to achieve part or all of the above-mentioned effects, the technical features of the embodiments corresponding to the technical features in the various modes described below can be appropriately replaced or combined. In addition, if the technical feature is not described as a necessary technical feature in this specification, it can be appropriately deleted.

[0103] (1) According to one aspect of the present disclosure, there is provided a method for producing a three-dimensional object by laminating layers to shape the three-dimensional object. The manufacturing method comprises: a first step of plasticizing a material to generate a plasticized material, and conveying the plasticized material toward a nozzle opening of a nozzle; a second step of moving the nozzle relative to a stage while ejecting the plasticized material from the nozzle opening, thereby forming a layer on the stage; and a third step of stopping ejecting the plasticized material from the nozzle opening during a movement time when the nozzle moves relatively from an ejection stop position where ejection from the nozzle opening is stopped to a re-start ejection position located at the same layer as the ejection stop position, and ejection from the nozzle opening is started again, wherein in the third step, ejection of the plasticized material from the nozzle opening is stopped by adjusting an opening area of ​​a flow path through which the plasticized material flows toward the nozzle opening, and a first control of controlling the position of the nozzle is performed so that a difference between a first case where a distance from the ejection stop position to the re-start ejection position, i.e., a first moving time, is a first moving time, and a second case where the moving distance is a second distance shorter than the first distance, i.e., a second moving time, is within a predetermined range. According to this mode, even when the distance from the ejection stop position to the ejection restart position is not constant, the movement time is controlled to be within a predetermined range, so that the deviation of the pressure in the flow path upstream of the opening area adjustment portion after the movement time has passed can be suppressed. Therefore, the deviation of the ejection amount of the plasticized material at the ejection restart position can be suppressed.

[0104] (2) In the above aspect, the first movement time may be equal to the second movement time. According to this aspect, since the time for stopping the ejection of the plasticized material from the nozzle opening can be equalized, the effect of suppressing the deviation of the pressure in the flow path upstream of the opening area adjustment portion can be improved.

[0105] (3) In the above-mentioned method, as the first control, a speed control may be performed to control the movement speed of the nozzle in the first case to be greater than the movement speed in the second case. According to this method, by adjusting the movement speed, the difference between the first movement time and the second movement time can be reduced. Compared with the case where the movement path of the nozzle is changed to increase the path length in order to adjust the movement time, the increase in calculation load can be suppressed.

[0106] (4) In the above-mentioned aspect, as the first control, in the second case, the following may be performed: first-stage control to move the nozzle relative to the stage from a first vertical distance, which is a distance between the nozzle and the stage at the ejection stop position, to a second vertical distance longer than the first vertical distance; second-stage control to move the nozzle relative to the stage from a position at the second vertical distance to a position at the first vertical distance; and third-stage control to move the nozzle relative to the stage from the ejection stop position to the ejection restart position. According to this aspect, in the second case, by performing the first-stage control and the second-stage control, the difference between the first moving time and the second moving time can be reduced.

[0107] (5) In the above method, it is also possible to further include an acquisition process for acquiring molding data, wherein the molding data includes a first molding area and a second molding area set with a molding accuracy lower than that of the first molding area, and the first control is performed when the ejection restart position is the molding start position of the first molding area, and when the ejection restart position is the molding start position of the second molding area, the second control is performed to control the movement time to be shorter as the movement distance is shorter, instead of the first control. According to this method, by appropriately setting the predetermined speed, it is possible to maintain the molding accuracy and suppress the molding time from being prolonged, compared with the case where the first control is performed for the entire range of the molding data.

[0108] (6) In the above-mentioned method, there may be further provided a step of acquiring molding data in which a plurality of non-ejection paths are set, wherein each of the plurality of non-ejection paths is a path from the ejection stop position to the ejection restart position, and the moving speed can be set within a predetermined speed range. In the speed control, when the non-ejection path with the longest distance among the plurality of non-ejection paths is moved, the moving speed is set to the maximum speed in the speed range. According to this method, compared with the case where the moving speed of the non-ejection path with the longest distance that moves to stop the ejection of the plasticized material from the nozzle opening is set to a speed that is smaller than the maximum speed in the speed range, the total time of the time in which the ejection of the plasticized material from the nozzle opening is stopped can be shortened. Therefore, it is possible to suppress a decrease in manufacturing efficiency.

[0109] (7) In the above-mentioned method, in the first step, the plasticized material is generated by supplying the material to a plasticizing unit having a screw and a motor for rotating the screw, and in the third step, during the moving time, any one of control of stopping the rotation speed of the screw and control of reducing the rotation speed of the screw is performed. According to this method, it is possible to suppress the increase in pressure of the flow path from the opening area adjustment portion to the upstream, and suppress the ejection amount when ejection is restarted from becoming significantly larger than the target amount.

[0110] The present disclosure is not limited to the above-mentioned three-dimensional modeling manufacturing method, and can be implemented by various schemes such as a three-dimensional modeling device, a three-dimensional modeling system, a computer program, and a non-transitory tangible recording medium on which the computer program is recorded in a computer-readable manner.

Claims

1. A method for manufacturing a three-dimensional object, characterized in that: A three-dimensional object is formed by stacking layers, and the method for producing the three-dimensional object comprises: In a first step, the material is plasticized to generate a plasticized material, and the plasticized material is conveyed toward a nozzle opening of the nozzle; A second step of moving the nozzle relative to the stage while ejecting the plasticized material from the nozzle opening, thereby forming a layer on the stage; as well as In a third step, during a movement time in which the nozzle moves relative to the stage from the ejection stop position where ejection from the nozzle opening is stopped to the re-start ejection position where ejection from the nozzle opening is restarted, the re-start ejection position being located at the same layer as the ejection stop position, In the third step, The ejection of the plasticized material from the nozzle opening is stopped by adjusting the opening area of ​​the flow path through which the plasticized material flows toward the nozzle opening, A first control is performed to control the movement of the nozzle relative to the stage so that a difference between a first movement time and a second movement time is within a predetermined range, wherein the first movement time is the movement time in a first case where the distance from the ejection stop position to the ejection restart position, i.e., the movement distance is a first distance, and the second movement time is the movement time in a second case where the movement distance is a second distance shorter than the first distance.

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

3. The method for manufacturing a three-dimensional object according to claim 1 or 2, wherein: As the first control, speed control is performed in which the moving speed of the nozzle in the first case is controlled to be greater than the moving speed in the second case.

4. The method for manufacturing a three-dimensional object according to claim 1 or 2, wherein: As the first control, In the second case proceed: In a first stage control, the nozzle is moved relative to the stage from a first vertical distance between the nozzle and the stage at the ejection stop position to a second vertical distance longer than the first vertical distance; In the second stage of control, the nozzle is moved relative to the stage from the position of the second vertical distance to the position of the first vertical distance; as well as The third stage control moves the nozzle relative to the stage from the ejection stop position to the ejection restart position.

5. The method for manufacturing a three-dimensional object according to claim 1 or 2, wherein: There is also a process for acquiring modeling data. The modeling data includes a first modeling area and a second modeling area set to have a modeling accuracy lower than that of the first modeling area. The first control is performed when the restart spraying position is the molding start position of the first molding area, and the first control is replaced by a second control in which the shorter the moving distance, the shorter the moving time.

6. The method for manufacturing a three-dimensional object according to claim 3, wherein: The method further comprises a step of acquiring molding data in which a plurality of non-discharging paths are set. Each of the plurality of non-discharging paths is a path from the discharge stop position to the discharge restart position. The moving speed can be set within a predetermined speed range. In the speed control, when the non-discharging path having the longest distance among the plurality of non-discharging paths is moved, the moving speed is set to a maximum speed in the speed range.

7. The method for manufacturing a three-dimensional object according to claim 1, wherein: In the first step, the plasticized material is produced 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 moving time.

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