Method for producing three-dimensionally shaped object

Abstract

Provided is a method for manufacturing a three-dimensional molded article, which is capable of suppressing deformation of a molding material positioned above a cavity of the three-dimensional molded article due to gravity. This method for manufacturing a three-dimensional molded article has a first step in which a molded article having a cavity section is molded by laminating a plurality of layers by discharging a molding material toward a stage, the first step having a second step in which a plurality of layers are laminated by discharging a molding material toward the stage. Each of the layers is stacked so as to have an overlapping portion that is in contact with the layer directly below in the stacking direction and a non-overlapping portion that does not overlap with the layer directly below and forms a space in the stacking direction, and a top surface having two inclined surfaces that intersect with each other is formed at the upper part of the cavity portion by the non-overlapping portion. The standing angle of each of the two inclined surfaces from a surface parallel to the table is 35 DEG or more and less than 90 DEG.

Description

Technical Field

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

[0002] Patent Document 1 discloses a three-dimensional modeling device for forming a bridge structure without a supporting material.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2016-101731

[0004] When a three-dimensional object having a cavity is formed without using a supporting material, a portion located above the cavity may be deformed due to gravity. Summary of the invention

[0005] According to a first aspect of the present disclosure, a method for manufacturing a three-dimensional object is provided. The manufacturing method has a first process, in which a plurality of layers are stacked by ejecting a molding material toward a workbench to mold a molding object having a cavity portion, and the first process has a second process, in which a plurality of the layers are stacked in a manner that each of the layers has a repeating portion that is connected to the layer directly below in the stacking direction and a non-repeating portion that does not overlap with the layer directly below and forms a space below, and a top surface having two intersecting inclined surfaces is formed on the upper part of the cavity portion by the non-repeating portion, and the two inclined surfaces each have a rising angle of 35° or more and less than 90° from a surface parallel to the workbench. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

[0008] Figure 3 This is a simplified top view of the barrel.

[0009] Figure 4 This is an explanatory diagram schematically showing a situation in which 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 It is a flowchart of the modeling process.

[0012] Figure 7 It is a schematic diagram showing the shape of the sculptured object.

[0013] Figure 8 It is an explanatory diagram of the top surface forming process.

[0014] Figure 9 It is a figure which shows the cross section of a sculptured object.

[0015] Figure 10 The figure shows the molding results of a plurality of samples having a cavity portion.

[0016] Figure 11 : is an image showing the modeling result of sample 1.

[0017] Figure 12 The image shows the modeling result of sample 2.

[0018] Figure 13 The image shows the modeling result of sample 3.

[0019] Figure 14 The image shows the modeling result of sample 4.

[0020] Figure 15 The image shows the modeling result of sample 5.

[0021] Figure 16 The image shows the modeling result of sample 6.

[0022] Figure 17 The image shows the modeling result of sample 7.

[0023] Figure 18 The image shows the modeling result of sample 8.

[0024] Figure 19 : is an image showing the modeling result of sample 10.

[0025] Figure 20 : is an image showing the modeling result of sample 11.

[0026] Figure 21 : is an image showing the modeling result of sample 12.

[0027] Figure 22 The image shows the modeling result of sample 13.

[0028] Figure 23 : is an image showing the modeling result of sample 14.

[0029] Figure 24 It is a figure which shows another shape of a cavity part.

[0030] Figure 25 It is a figure which shows the cross section of a sculptured object.

[0031] Description of Reference Numerals

[0032] 10: 3D molding system, 20: material supply unit, 22: communication channel, 30: plasticizing unit, 31: screw box, 32: drive motor, 40: screw, 42: groove, 43: rib, 44: material inlet, 46: central unit, 47: upper surface, 48: lower surface, 50: barrel, 52: upper surface, 54: guide groove, 56: communication hole, 57: first barrel heater, 58: second barrel heater, 59: nozzle heater, 60: ejection unit, 61: nozzle, 62: nozzle opening, 65: flow path, 66: branch flow path, 67: plunger, 70: ejection amount adjustment mechanism , 74: first drive unit, 75: suction mechanism, 76: second drive unit, 77: ejection control unit, 100: three-dimensional modeling device, 110: head, 210: workbench, 211: modeling surface, 212: workbench 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, 440: communication interface, 450: input and output interface, 460: bus, 470: input device, 480: display unit. DETAILED DESCRIPTION

[0033] A. First Implementation Method:

[0034] Figure 1 It is an explanatory diagram showing a schematic configuration of a three-dimensional modeling system 10 in the first embodiment. Figure 1 The arrows indicating the mutually orthogonal X, Y, and Z directions are shown in the figure. The X and Y directions 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 figure in other figures. Figure 1 The corresponding manner is appropriately illustrated. In the following description, when the direction is specified, the direction indicated by the arrow is "+" in each figure, and the opposite direction is "-", and positive and negative signs are used in writing the direction. Hereinafter, the +Z direction is also referred to as "up", and the -Z direction is also referred to as "down".

[0035] 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.

[0036] The three-dimensional modeling apparatus 100 includes a head 110 for generating and ejecting a modeling material, a modeling table 210 as a base for a modeled object, and a moving mechanism 230 for controlling the ejection position of the modeling material.

[0037] Under the control of the control unit 300, the head 110 sprays a molding material onto the workbench 210. The molding material is obtained by plasticizing a material in a solid state. The head 110 includes: a material supply unit 20, which is a supply source of the raw material before being converted into the molding material; a plasticizing unit 30, which converts the raw material into the molding material; and a spraying unit 60, which sprays the molding material.

[0038] 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 that accommodates the raw material MR. The material supply unit 20 is connected to the plasticizing unit 30 via a communication channel 22. The raw material MR is put into the material supply unit 20 in the form of powder or granules. As the raw material MR, for example, thermoplastic resin materials such as ABS (acrylonitrile-butadiene-styrene), PEEK (polyetheretherketone), and PP (polypropylene) are used, or materials containing metal particles or ceramics and adhesives are used.

[0039] The plasticizing unit 30 plasticizes the raw material MR supplied from the material supply unit 20 to generate a paste-like molding material showing fluidity, and guides it to the spraying unit 60. In the present embodiment, "plasticizing" includes the concept of melting, and refers to changing from a solid state to a state with fluidity. Specifically, in the case of a material that undergoes a glass transition, plasticizing means making the temperature of the material above the glass transition temperature. In the case of a material that does not undergo a glass transition, plasticizing means making the temperature of the material above the melting point.

[0040] The plasticizing unit 30 has a screw box 31, a drive motor 32, a screw 40, and a barrel 50. The screw 40 is also referred to as a flat screw, a rotor, or a scroll. The barrel 50 is also referred to as a screw opposing part.

[0041] The screw 40 is housed in the screw box 31. The upper surface 47 of the screw 40 is connected to the drive motor 32, and the screw 40 rotates in the screw box 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. It should be noted that the screw 40 can also be driven by the drive motor 32 via a speed reducer.

[0042] Figure 2 is a perspective view showing a schematic configuration of the lower surface 48 side of the screw 40. For the convenience of understanding the technology, the Figure 1 shown upper surface 47 and the lower surface 48 are shown in a state where their positional relationship is reversed in the vertical direction Figure 2 shown screw 40. The screw 40 has a substantially cylindrical shape with a length in the direction of its central axis, i.e., the axial direction, shorter than the length in the direction perpendicular to the axial direction. The screw 40 is arranged such that its rotation axis RX as the rotation center is parallel to the Z direction.

[0043] On the lower surface 48 of the screw 40, which is a surface intersecting with the rotation axis RX, a spiral groove portion 42 is formed. The communication passage 22 of the above-described material supply portion 20 communicates with the groove portion 42 from the side surface of the screw 40. In the present embodiment, the groove portion 42 is separated by the rib portion 43 and formed into three. It should be noted that the number of the groove portions 42 is not limited to three, and may be one, or may be two or more. The groove portion 42 is not limited to a spiral shape, and may be a helical shape or an involute curve shape, or may be a shape extending in an arc-drawing manner from the central portion 46 toward the outer periphery.

[0044] As Figure 1 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 portion 42 on the lower surface 48 of the screw 40 and the upper surface 52 of the barrel 50. The raw material MR is supplied from the material supply portion 20 through Figure 2 the material inlet 44 shown into this space between the screw 40 and the barrel 50.

[0045] In the barrel 50, as heaters for heating the raw material MR supplied into the groove portion 42 of the rotating screw 40, a first barrel heater 57 and a second barrel heater 58 are buried. The first barrel heater 57 heats the inner portion of the barrel 50. The second barrel heater 58 heats the outer portion of the barrel 50. The temperatures of the first barrel heater 57 and the second barrel heater 58 are controlled by the control portion 300. A communication hole 56 is provided at the center of the barrel 50.

[0046] Figure 3 is a schematic top view of the upper surface 52 side of the barrel 50. On the upper surface 52 of the barrel 50, a plurality of guide grooves 54 are formed which are connected to the communication hole 56 and extend in a spiral shape from the communication hole 56 toward the outer periphery. It should be noted that one end of the guide groove 54 may not be connected to the communication hole 56. In addition, the guide groove 54 may be omitted.

[0047] The raw material MR supplied into the groove portion 42 of the screw 40 is plasticized while flowing in the groove portion 42, and flows along the groove portion 42 due to the rotation of the screw 40, and is guided as a molding material to the central portion 46 of the screw 40. The paste-like molding material showing fluidity flowing into the central portion 46 is supplied to the ejection portion 60 through the communication hole 56 provided at the center of the barrel 50. It should be noted that in the molding material, not all types of substances constituting the molding material may be plasticized. The molding material only needs to be in a state where it has fluidity as a whole by plasticizing at least a part of the types of substances constituting the molding material.

[0048] Figure 1The ejection unit 60 includes a nozzle 61 for ejecting the molding material, a flow path 65 for the molding material provided between the screw 40 and the nozzle opening 62, and an ejection control unit 77 for controlling the ejection of the molding material.

[0049] The nozzle 61 is connected to the communication hole 56 of the hopper 50 through the flow path 65. The nozzle 61 ejects the molding material generated in the plasticizing unit 30 from the nozzle opening 62 at the front end toward the worktable 210. A nozzle heater 59 for suppressing the temperature drop of the molding material is embedded in the nozzle 61. The temperature of the nozzle heater 59 is controlled by the control unit 300.

[0050] The ejection control unit 77 includes an ejection amount adjustment mechanism 70 for opening and closing the flow path 65 and a suction mechanism 75 for sucking and temporarily storing the molding material.

[0051] The ejection 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 the present embodiment, the ejection amount adjustment mechanism 70 is constituted by 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 constituted by, for example, a stepping motor. The control unit 300 can adjust the flow rate of the molding material flowing from the plasticizing unit 30 to the nozzle 61 by controlling the rotation angle of the valve using the first drive unit 74, that is, can adjust the ejection amount of the molding material ejected from the nozzle 61. The ejection amount adjustment mechanism 70 can adjust the ejection amount of the molding material and can control the opening / closing of the outflow of the molding material.

[0052] 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 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 constituted by, for example, a stepping motor, a rack and pinion transmission mechanism that converts the rotational force of the stepping motor into the translational movement of the plunger 67, and the like.

[0053] The control unit 300 controls the suction mechanism 75 to pull the plunger 67 when stopping the ejection of the molding material from the nozzle 61, thereby temporarily sucking the molding material in the flow path 65 into the branch flow path 66. In this way, it is possible to suppress the trailing phenomenon in which the molding material sags in a stringy manner from the nozzle opening 62. In addition, when restarting the ejection of the molding material from the nozzle 61, the control unit 300 sucks the molding material in the flow path 65 by pulling the plunger 67 and sends the molding material into the flow path 65 by pushing the plunger 67, thereby adjusting the ejection amount of the molding material ejected from the nozzle 61 to be constant. In this way, when restarting the ejection, it is possible to keep the line width of the molding material constant.

[0054] The worktable 210 is disposed at a position facing the nozzle opening 62 of the nozzle 61. In the first embodiment, the molding surface 211 of the worktable 210 facing the nozzle opening 62 of the nozzle 61 is disposed parallel to the X and Y directions, that is, the horizontal direction. The worktable 210 includes a worktable heater 212 for suppressing the rapid cooling of the molding material ejected onto the worktable 210. The worktable heater 212 is controlled by the control unit 300.

[0055] The moving mechanism 230 changes the relative position between the worktable 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 worktable 210. The moving mechanism 230 is composed of a three-axis positioner that moves the worktable 210 in three axial directions of the X, Y, and Z directions by using the driving force of three motors. In this specification, unless otherwise specified, the movement of the nozzle 61 means moving the nozzle 61 and the ejection unit 60 relative to the worktable 210.

[0056] It should be noted that in other embodiments, instead of the configuration in which the worktable 210 is moved by the moving mechanism 230, a configuration in which the moving mechanism 230 moves the nozzle 61 relative to the worktable 210 while fixing the position of the worktable 210 may be adopted. In addition, a configuration in which the worktable 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 worktable 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 with these configurations, the relative positional relationship between the nozzle 61 and the worktable 210 can be changed.

[0057] The control unit 300 is a control device that controls the overall operation of the three-dimensional modeling device 100. The control unit 300 is composed of a computer, which includes one or more processors 310, a storage device 320 composed of a main storage device and an auxiliary storage device, and an input / output interface for inputting and outputting signals to and from the outside. By executing the program stored in the storage device 320, 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, and performs the modeling of the modeled object on the workbench 210. It should be noted that the control unit 300 can also be implemented by a combination circuit configuration instead of being composed of a computer.

[0058] Figure 4 FIG. is an explanatory diagram schematically showing the situation where the three-dimensional modeling device 100 models a modeled object. In the three-dimensional modeling device 100, as described above, the solid raw material MR is plasticized to generate the modeling material MM. While maintaining the distance between the modeling surface 211 of the workbench 210 and the nozzle 61, the control unit 300 changes the position of the nozzle 61 relative to the workbench 210 in the direction along the modeling surface 211 of the workbench 210, and ejects the modeling material MM from the nozzle 61. The modeling material MM ejected from the nozzle 61 continuously accumulates in the moving direction of the nozzle 61.

[0059] The control unit 300 repeatedly moves the nozzle 61 to form a layer ML. After forming one layer ML, the control unit 300 relatively moves the position of the nozzle 61 relative to the workbench 210 in the Z direction, which is the stacking direction, by an amount corresponding to a preset stacking pitch. Then, the modeled object is modeled by further stacking the layer ML on the layer ML formed so far.

[0060] For example, when the nozzle 61 moves in the Z direction when one layer of the layer ML is completed and there are multiple independent modeling regions in each layer, the control unit 300 may sometimes temporarily interrupt the ejection of the modeling material from the nozzle 61. In this case, the control unit 300 closes the flow path 65 through the ejection amount adjustment mechanism 70, for example, stops ejecting the modeling material MM from the nozzle opening 62, and temporarily sucks the modeling material in the nozzle 61 through the suction mechanism 75. In addition, after changing the position of the nozzle 61, for example, the control unit 300 discharges the modeling material in the suction mechanism 75 and opens the flow path 65 through the ejection amount adjustment mechanism 70, so as to restart the accumulation of the modeling material MM from the changed position of the nozzle 61.

[0061] Figure 5It is an explanatory diagram showing a schematic configuration of the information processing apparatus 400. The information processing apparatus 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 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 apparatus 400 is connected to the control unit 300 of the three-dimensional modeling apparatus 100 via the communication interface 440.

[0062] The CPU 410 functions as a data generation unit 411 by executing a program stored in the storage device 430.

[0063] The data generation unit 411 generates modeling data. The modeling data is data representing information related to, for example, the movement route of the nozzle 61 relative to the worktable 210, the amount of the modeling material ejected from the nozzle 61, the rotational speed of the screw 40, and the like. The data generation unit 411 reads in shape data representing the shape of a three-dimensional model created using three-dimensional CAD software or three-dimensional CG software, and divides the shape of the three-dimensional model into layers of a specified thickness. The data generation unit 411 generates modeling data by determining the movement route of the nozzle 61 and the amount of the modeling material so as to fill each of the divided layers with the modeling material. The nozzle 61 moves along the movement route specified by the modeling data and ejects the amount of the modeling material specified by the modeling data, thereby forming a path having a specified line width on the worktable 210.

[0064] Figure 6 It is a flowchart of a modeling process for implementing a method of manufacturing a three-dimensional model. This modeling process is executed by the control unit 300 of the three-dimensional modeling apparatus 100. In step S10, the control unit 300 acquires the modeling data generated by the information processing apparatus 400.

[0065] Figure 7It is a schematic diagram showing the shape of the modeled object MD modeled in the present embodiment. In the present embodiment, a rectangular parallelepiped-shaped modeled object MD having a tubular cavity portion CV along the Y direction at the center in the X and Z directions is modeled. The cavity portion CV is used as a pipe after the modeled object MD is completed, and fluid flows inside it. The cavity portion CV has different shapes at the upper and lower parts. At the upper part of the cavity portion CV, a top surface TS having two intersecting inclined surfaces S1 and S2 is formed. The standing angles D of the two inclined surfaces S1 and S2 are each less than 90°. The standing angle D is the angle at which the inclined surfaces S1 and S2 stand up from the surface parallel to the workbench 210. The standing angle D of the inclined surface S1 and the standing angle D of the inclined surface S2 may be the same angle or different angles. At the lower part of the cavity portion CV, a semicircular bottom surface BS is formed. If the bottom surface BS of the lower part of the cavity portion CV is semicircular, when the fluid flows into the cavity portion CV after the modeled object MD is completed, the flow path resistance of the cavity portion CV can be reduced. Such an effect is remarkable when the liquid as the fluid flows in the lower part of the cavity portion CV. The modeling data obtained from the information processing device 400 is used to model the Figure 7 modeled object MD shown layer by layer.

[0066] In Figure 6 step S20, the control unit 300 performs a stacking process. In this stacking process, the control unit 300 controls the plasticizing unit 30, the ejection control unit 77, and the moving mechanism 230 according to the modeling data obtained in step S10, and ejects the modeling material toward the workbench 210, thereby stacking multiple layers to model the modeled object MD having the cavity portion CV. Step S20 is also referred to as the first process.

[0067] The stacking process in step S20 includes the top surface formation process in step S30. The top surface formation process is a process for forming the Figure 7 top surface TS shown. Step S30 is also referred to as the second process.

[0068] Figure 8 is an explanatory diagram of the top surface formation process. In Figure 8 , the uppermost multiple layers for forming the top surface TS are shown enlarged. In the top surface formation process, the control unit 300 controls the plasticizing unit 30, the ejection control unit 77, and the moving mechanism 230 according to the modeling data, so as to stack the multiple layers in such a way that each layer has a repeating portion OV1 that is connected to the layer directly below in the stacking direction and a non-repeating portion OV2 that does not overlap with the layer directly below and has a space formed below. In Figure 8 , the repeating portion OV1 is hatched and the non-repeating portion OV2 is single-hatched. The control unit 300 forms the non-repeating portion OV2 in each layer, thereby forming the top surface TS having two intersecting inclined surfaces S1 and S2 at the upper part of the cavity portion CV.

[0069] Figure 9 This is a diagram showing a cross-section of the molded object MD. Each layer for forming the cavity portion CV has an outermost peripheral region CR and an inner region IR that is adjacent to the inside of the outermost peripheral region CR. The outermost peripheral region CR is the region in each layer for molding the outermost circumference of the molded object MD. In Figure 9 the example shown, an example is shown in which the inner region IR is composed of a zigzag pattern with a filling rate of 100% and a honeycomb pattern with a filling rate of 25%. The zigzag pattern is formed in the region of the inner region IR close to the cavity portion CV, and the honeycomb pattern is formed in the region of the inner region IR far from the cavity portion CV. It should be noted that the inner region IR can also be entirely molded by a single pattern with a filling rate of 100%. As the pattern for molding the inner region IR, it is not limited to the zigzag pattern and the honeycomb pattern, and other patterns such as concentric circle patterns and triangular patterns can also be used.

[0070] In the above step S30, the control unit 300 molds each layer in such a way that at least a part of the outermost peripheral path for molding the outermost peripheral region CR overlaps with the inner path for molding the inner region IR. In this way, it is possible to suppress the peeling of the outermost peripheral region CR from the inner region IR.

[0071] The amount of overlap of the line widths of the inner path and the outermost peripheral path is referred to as the overlap amount. In Figure 9 , the range where the overlap occurs is shown as the overlap portion OP. In step S30, the control unit 300 stacks each layer in such a way that the outermost peripheral path and the inner path overlap at least a part of the non-repeating portion OV2 for forming the top surface TS. That is, in Figure 8 , each layer is molded in such a way that the overlap portion OP is located in the single hatched portion representing the non-repeating portion OV2 to form the top surface TS. In this way, the strength of the top surface TS can be improved.

[0072] Figure 10 This is a diagram showing the molding results of multiple samples having a cavity portion CV. Figures 11 to 23 This is an image showing the molding results of each sample. In the present embodiment, samples of 13 molded objects MD with different upright angles D of the inclined surfaces S1 and S2, molding materials, overlap amounts, etc. were molded, and the appearance shapes of these cavity portions CV were visually confirmed for evaluation. In Figure 10 , the evaluation results are shown as "A" or "B". Evaluation A indicates that the cavity portion CV is well molded, and evaluation B indicates that the cavity portion CV is not well molded. Hereinafter, the details of each sample will be described.

[0073] As the modeling material for Sample 1, a metallic material containing metal particles of SUS630 and 7 mass parts of a fluidity component, an adhesiveness component, a moldability component, and a plasticizer as a binder was used. As the modeling conditions for Sample 1, the diameter of the nozzle opening 62 was set to 0.4 mm, the line width of the path was set to 0.5 mm, the layer spacing was set to 0.2 mm, the material extrusion speed from the nozzle 61 was set to 50 mm / second, the temperature of the first barrel heater 57 was set to 90 °C, the temperature of the second barrel heater 58 was set to 80 °C, the temperature of the nozzle heater 59 was set to 125 °C, and the overlap amount was set to 30%. The shape of Sample 1 was Figure 7 the shape of the modeled object MD shown. Specifically, the following modeled object MD was modeled: A substantially circular cavity portion CV with a diameter of 10 mm was provided at the center of a 25 mm square cube, and the rising angles D of the inclined surfaces S1 and S2 constituting the top surface TS of the cavity portion CV were 35° respectively. As a result, as Figure 11 shown, a cavity portion CV with a good shape was formed without modeling a support structure within the cavity portion CV.

[0074] The modeling material and modeling conditions for Sample 2 were the same as those for Sample 1. Regarding the shape of Sample 2, only the rising angles D of the inclined surfaces S1 and S2 were different from those of Sample 1 and were set to 45°. As a result, as Figure 12 shown, a cavity portion CV with a good shape was formed without modeling a support structure within the cavity portion CV.

[0075] The modeling material and modeling conditions for Sample 3 were the same as those for Sample 1. Regarding the shape of Sample 3, only the rising angles D of the inclined surfaces S1 and S2 were different from those of Sample 1 and were set to 55°. As a result, as Figure 13 shown, a cavity portion CV with a good shape was formed without modeling a support structure within the cavity portion CV.

[0076] The modeling material and modeling conditions for Sample 4 were the same as those for Sample 1. Regarding the shape of Sample 4, only the rising angles D of the inclined surfaces S1 and S2 were different from those of Sample 1 and were set to 70°. As a result, as Figure 14 shown, a cavity portion CV with a good shape was formed without modeling a support structure within the cavity portion CV.

[0077] The modeling material and modeling conditions for Sample 5 were the same as those for Sample 1. The shape of Sample 5 was the shape obtained by scaling up the size of Sample 1 by 1.5 times. Specifically, the following modeled object MD was modeled: A substantially circular cavity portion CV with a diameter of 15 mm was provided in a 37.5 mm square cube, and the rising angles D of the inclined surfaces S1 and S2 constituting the top surface TS of the cavity portion CV were 35° respectively. As a result, as Figure 15As shown, a cavity portion CV with a good shape is formed without shaping the support structure within the cavity portion CV.

[0078] The modeling material and modeling conditions of Sample 6 are the same as those of Sample 1. Regarding the shape of Sample 1, the dimensions in the X and Y directions are set to 25 mm, the same as those of Sample 1, and the dimension in the Z direction is set to 30 mm, different from that of Sample 1. The shape of the cavity portion CV is the same as that of Sample 1. In Sample 6, the height of the cavity portion CV from the workbench 210 remains unchanged from that of Sample 1, and the modeled object MD is modeled in such a way that a 5-mm thickness is added to the upper part of the cavity portion CV. As a result, as Figure 16 shown, a cavity portion CV with a good shape is formed without shaping the support structure within the cavity portion CV.

[0079] The modeling material of Sample 7 is different from that of Sample 1 and is a PLA resin without metal powder. Regarding the modeling conditions, the temperature of the first barrel heater 57 is set to 240 °C, the temperature of the second barrel heater 58 is set to 230 °C, and the temperature of the nozzle heater 59 is set to 205 °C. Other conditions are the same as those of Sample 1. The shape of Sample 7 is the same as that of Sample 1. As a result, as Figure 17 shown, a cavity portion CV with a good shape is formed without shaping the support structure within the cavity portion CV.

[0080] The modeling material of Sample 8 is the same as that of Sample 1. In Sample 8, the overlap amount is set to 10%, and other modeling conditions are the same as those of Sample 1. The shape of Sample 8 is the same as that of Sample 1. As a result, as Figure 18 shown, a cavity portion CV with a good shape is formed without shaping the support structure within the cavity portion CV.

[0081] The modeling material of Sample 9 is the same as that of Sample 1. In Sample 9, the overlap amount is set to 50%, and other modeling conditions are the same as those of Sample 1. The shape of Sample 9 is the same as that of Sample 1. As a result, as Figure 19 shown, a cavity portion CV with a good shape is formed without shaping the support structure within the cavity portion CV.

[0082] The modeling material of Sample 10 is the same as that of Sample 1. In Sample 10, the overlap amount is set to 100%, and other modeling conditions are the same as those of Sample 1. The shape of Sample 10 is the same as that of Sample 1. As a result, as Figure 20 shown, a cavity portion CV with a good shape is formed without shaping the support structure within the cavity portion CV.

[0083] The modeling material and modeling conditions of Sample 11 are the same as those of Sample 1. In Sample 11, the shape of the cavity portion CV is a circle with a diameter of 15 mm, and the two inclined surfaces S1 and S2 are not formed. As a result, as Figure 21As shown, the material droops from the top surface TS of the cavity portion CV, and the cavity portion CV cannot be formed well.

[0084] The molding material and molding conditions of sample 12 are the same as those of sample 1. In sample 12, only the rising angle D of the inclined surfaces S1 and S2 is different from that of sample 1, and it is set to 30°. As a result, as Figure 22 shown, the material droops from the upper surface of the cavity portion CV, and the cavity portion CV cannot be formed well.

[0085] The molding material and molding conditions of sample 13 are the same as those of sample 1. In sample 13, only the overlapping amount is different from that of sample 1, and it is set to 0%. As a result, as Figure 23 shown, the material droops from the top surface TS of the cavity portion CV, and the cavity portion CV cannot be formed well.

[0086] As described above, in sample 11 where the rising angle D of the inclined surfaces S1 and S2 forming the top surface TS of the cavity portion CV is 30°, the cavity portion CV was not formed well, and in sample 1 where the rising angle D is 35°, the cavity portion CV was formed well. Therefore, in order to suppress the deformation of the portion of the molded object MD above the cavity portion CV due to gravity and to form the cavity portion CV without molding the support structure, the rising angle D is preferably 35° or more. In addition, in order to form the top surface TS by the two inclined surfaces S1 and S2, the rising angle D must be less than 90°. Therefore, the rising angle D of the inclined surfaces S1 and S2 is preferably 35° or more and less than 90°. In addition, in samples 2 to 4 where the rising angle D is 45°, 55°, and 70° respectively, the cavity portion CV can also be formed well. Therefore, in order to suppress the stress concentration at the intersection of the inclined surfaces S1 and S2, the rising angle D is preferably 35° or more and 70° or less, and more preferably 35° or more and 55° or less.

[0087] It should be noted that in sample 5, the size of the molded object MD is 1.5 times that of sample 1, and in sample 6, the thickness of the molded object above the cavity portion CV is increased by 5 mm. In addition, in sample 7, a resin material lighter than metal in weight ratio is used. For these samples 5, 6, and 7, by setting the rising angle D of the inclined surfaces S1 and S2 to 35°, the cavity portion CV can also be formed well. Therefore, regardless of the size, weight of the molded object MD, and the thickness of the molded object above the cavity portion CV, the rising angle D is preferably 35° or more. Especially when using a metal material as the molding material, the weight applied to the top surface TS becomes larger, so the effect of specifying the rising angle D of the inclined surfaces S1 and S2 as described above is great.

[0088] In sample 8 with an overlap amount of 10%, the cavity portion CV was well formed. In sample 13 with an overlap amount of 0%, the cavity portion CV could not be well formed. Therefore, when forming the shaped object MD, it is preferable to form each layer in such a way that at least a part of the outermost peripheral path for forming the outermost peripheral region CR overlaps with the inner path for forming the inner region IR. In particular, based on the results of sample 8, it is preferable that the overlap amount of the inner path overlapping the outermost peripheral path is 10% or more with respect to the line width of the outermost peripheral path. It should be noted that cavity portions CV were well formed in samples 8, 1, 9, and 10 with overlap amounts of 10%, 30%, 50%, and 100% respectively. However, when the overlap amount is set to 100%, depending on the forming conditions, there may be a bulge due to the paths overlapping each other at the overlap portion, resulting in a decrease in forming accuracy. Therefore, the upper limit of the overlap amount is preferably 50%. That is, the overlap amount is preferably 10% or more and 50% or less.

[0089] B. Other embodiments:

[0090] (B1) Figure 24 is a diagram showing other shapes of the cavity portion CV. In the above embodiment, the cavity portion CV is formed at the center of the shaped object MD. In contrast, as Figure 24 shown, the cavity portion CV may also be formed to have an opening downward at the bottom of the shaped object MD.

[0091] (B2) Figure 25 is a diagram showing a cross-section of another shaped object MD. The cavity portion CV described in the above embodiment extends linearly within the shaped object MD. In contrast, within the shaped object MD, as Figure 25 shown, a plurality of cavity portions CV may also be formed to cross or connect with each other. In this case, it is preferable to perform the shaping of the shaped object MD in such a way that chamfers such as R chamfers are applied to the corner portions CP of the portions where the plurality of cavity portions CV cross or the corner portions CP of the portions where the plurality of cavity portions CV are connected, as shown by the dashed lines in Figure 25 . By chamfering the corner portions CP, when the fluid flows into the cavity portion CV, the flow path resistance of the cavity portion CV can be reduced.

[0092] In the above-described embodiment, each layer for forming the cavity portion CV has an outermost peripheral region CR and an inner region IR that is adjacent to the inside of the outermost peripheral region CR. In contrast, each layer for forming the cavity portion CV may not have an outermost peripheral region CR. That is, each layer may be composed only of the inner region IR. In this case, since there is no outermost peripheral region CR, an overlapping portion OP where the outermost peripheral path for shaping the outermost peripheral region CR and the inner path for shaping the inner region IR overlap is not formed. Therefore, at the non-overlapping portion OV2 of the top surface TS, the outermost peripheral path and the inner path do not have to overlap.

[0093] (B4)In the above-described embodiment, the inner region IR that is adjacent to the inside of the outermost peripheral region CR may have one or more circumferential intermediate regions that surround the entire inner region IR in a manner that is adjacent to the outermost peripheral region CR. By overlapping the outermost peripheral region CR with the intermediate region, an overlapping portion OP is formed. In this case, the outermost peripheral region CR and the intermediate region adjacent to its inside can be referred to as a shell region, and the inner region IR existing inside the shell region can be referred to as a filling region.

[0094] (B5)In the above-described embodiment, the plasticizing unit 30 plasticizes the material by a flat-head screw. In contrast, the plasticizing unit 30 may, for example, also plasticize the material by rotating an in-line screw. Additionally, the plasticizing unit 30 may also plasticize a filamentous material using a heater.

[0095] (B6)In the above-described embodiment, the three-dimensional modeling device 100 can, for example, use various materials such as a thermoplastic material, a metal material, and a ceramic material as the main material to model a three-dimensional object. "Main material" means the material that forms the center of the shape of the three-dimensional object and means the material having a content rate of 50 mass% or more in the three-dimensional object. Among the above-described modeling materials, there are materials obtained by melting these main materials as monomers and materials in which a part of the components contained together with the main material are melted to form a paste.

[0096] When using a thermoplastic material as the main material, the modeling material is generated by plasticizing the material in the plasticizing unit 30.

[0097] As the thermoplastic material, for example, the following thermoplastic resin materials can be used.

[0098] Examples of thermoplastic resin materials

[0099] General engineering plastics such as polypropylene resin (PP), polyethylene resin (PE), polyoxymethylene resin (POM), polyvinyl chloride resin (PVC), polyamide resin (PA), acrylonitrile-butadiene-styrene resin (ABS), polylactic acid resin (PLA), polyphenylene sulfide resin (PPS), polyetheretherketone (PEEK), polycarbonate (PC), modified polyphenylene ether, polybutylene terephthalate, polyethylene terephthalate, etc., and engineering plastics such as polysulfone, polyethersulfone, polyphenylene sulfide, polyaryl compound, polyimide, polyamideimide, polyetherimide, polyetheretherketone, etc.

[0100] In the thermoplastic material, pigments, metals, ceramics can also be mixed in. In addition, additives such as wax, flame retardant, antioxidant, heat stabilizer, etc. can also be mixed in. The thermoplastic material is plasticized in the plasticizing section 30 by the rotation of the screw 40 and the heating of the heater and is transformed into a molten state. After the molding material generated by the melting of the thermoplastic material is ejected from the nozzle 61, it solidifies due to the temperature reduction.

[0101] The thermoplastic material is preferably ejected from the nozzle 61 in a state of being completely melted by heating to a temperature above its glass transition temperature. For example, the glass transition temperature of the ABS resin is preferably about 120 °C, and it is about 200 °C when ejected from the nozzle 61.

[0102] In the three-dimensional modeling device 100, for example, the following metal materials can also be used as the main material to replace the above-mentioned thermoplastic material. In this case, it is preferably to mix the components that melt when generating the molding material in the powdery material of the following metal material in a powdery state, and input it into the plasticizing section 30 as the raw material.

[0103] Examples of metal materials

[0104] Single metals of magnesium (Mg), iron (Fe), cobalt (Co), chromium (Cr), aluminum (Al), titanium (Ti), copper (Cu), nickel (Ni), or alloys containing one or more of these metals.

[0105] Examples of the alloy

[0106] Maraging steel, stainless steel, cobalt-chromium-molybdenum, titanium alloy, nickel alloy, aluminum alloy, cobalt alloy, cobalt-chromium alloy.

[0107] In the three-dimensional modeling device 100, ceramic materials can be used as the main material to replace the above-mentioned metal materials. As the ceramic materials, for example, oxide ceramics such as silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, etc., and non-oxide ceramics such as aluminum nitride, etc. can be used. When using the above-mentioned metal materials and ceramic materials as the main materials, the molding materials arranged on the workbench 210 can also be cured by sintering using laser irradiation, hot air, etc.

[0108] The powder materials of metal materials and ceramic materials input into the material supply unit 20 as raw materials may also be mixed materials formed by mixing powders of a single metal, powders of alloys, and powders of ceramic materials. In addition, the powder materials of metal materials and ceramic materials may also be coated with a thermoplastic resin such as those exemplified above or other thermoplastic resins. In this case, in the plasticizing unit 30, the thermoplastic resin may also melt and exhibit fluidity.

[0109] In the powder materials of metal materials and ceramic materials input into the material supply unit 20 as raw materials, for example, the following solvents can also be added. One or more solvents selected from the following solvents can be used.

[0110] Examples of solvents

[0111] Water; (poly)alkylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, and propylene glycol monoethyl ether; acetate esters such as ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, and isobutyl acetate; aromatic hydrocarbons such as benzene, toluene, and xylene; ketones such as methyl ethyl ketone, acetone, methyl isobutyl ketone, ethyl n-butyl ketone, diisopropyl ketone, and acetylacetone; alcohols such as ethanol, propanol, and butanol; tetraalkylammonium acetates; sulfoxide solvents such as dimethyl sulfoxide and diethyl sulfoxide; pyridine solvents such as pyridine, γ-picoline, and 2,6-dimethylpyridine; tetraalkylammonium acetate (for example, tetrabutylammonium acetate, etc.); ionic liquids such as diethylene glycol butyl ether acetate.

[0112] In addition, in the powder materials of metal materials and ceramic materials input into the material supply unit 20 as raw materials, for example, the following binders can also be added.

[0113] Examples of binders

[0114] Various resins such as polyethylene, polypropylene, polyolefin, acrylic resin, styrene resin, polyvinyl chloride, polyamide, polyester, polyether, polyvinyl alcohol, and polyvinylpyrrolidone, various waxes, paraffin wax, higher fatty acids, higher alcohols, higher fatty acid esters, etc.

[0115] C. Other aspects:

[0116] The present disclosure is not limited to the above-described embodiments and can be implemented in various configurations without departing from its gist. For example, the technical features of the embodiments corresponding to the technical features in the following-described aspects can be appropriately replaced and combined to solve part or all of the above technical problems or achieve part or all of the above effects. In addition, if the technical features are not described as essential features in this specification, they can be appropriately deleted.

[0117] (1) According to a first aspect of the present disclosure, there is provided a method for manufacturing a three-dimensional shaped object. The manufacturing method has a first process in which a shaped object having a cavity portion is shaped by spraying a shaping material toward a worktable to stack a plurality of layers. The first process has a second process in which the plurality of layers are stacked in such a manner that each layer has a repeating portion that abuts the layer directly below in the stacking direction and a non-repeating portion that does not overlap the layer directly below and forms a space below. A top surface having two intersecting inclined surfaces is formed above the cavity portion through the non-repeating portion. Each of the two inclined surfaces has a standing angle of 35° or more and less than 90° from a surface parallel to the worktable.

[0118] According to such an aspect, it is possible to suppress deformation of a portion of the three-dimensional shaped object located above the cavity portion due to gravity.

[0119] (2) In the above aspect, it may also be that the standing angle is 35° or more and 70° or less.

[0120] (3) In the above aspect, it may also be that the standing angle is 35° or more and 55° or less.

[0121] (4) In the above aspect, it may also be that in the first process, the shaped object having a tubular cavity portion and a semi-circular portion opposed to the top surface in the stacking direction is shaped. According to such an aspect, when a fluid flows into the cavity portion, it is possible to reduce the flow path resistance of the cavity portion.

[0122] (5) In the above aspect, it may also be that each layer has an outermost peripheral region and an inner region that abuts the inside of the outermost peripheral region. In the second process, each layer is shaped in such a manner that at least a part of an outermost peripheral path for shaping the outermost peripheral region overlaps an inner path for shaping the inner region. According to such an aspect, it is possible to suppress peeling between the outermost peripheral region and the inner region.

[0123] (6) In the above aspect, it may also be that an overlapping amount of the inner path overlapping the outermost peripheral path is 10% or more and 50% or less with respect to the line width of the outermost peripheral path. According to such an aspect, it is possible to effectively suppress peeling between the outermost peripheral path and the inner path.

[0124] (7) In the above aspect, it may also be that in the second process, each layer is stacked in such a manner that the outermost peripheral path and the inner path overlap at at least a part of the non-repeating portion. According to such an aspect, it is possible to suppress peeling between the outermost peripheral path and the inner path in the non-repeating region.

[0125] (8) In the above aspect, it is also possible that the molding material includes metal particles and a thermoplastic resin.

[0126] The present disclosure is not limited to the above method for manufacturing a three-dimensional molded object, and can be implemented in various aspects such as a three-dimensional modeling device, 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: Having a first process, In the first step, a molding material is ejected toward a work table to stack a plurality of layers to mold a molding object having a cavity. The first step includes a second step in which the plurality of layers are stacked in such a manner that each layer has an overlapping portion that is in contact with a layer directly below in a stacking direction and a non-overlapping portion that does not overlap with the layer directly below and forms a space below. The non-repeating portion forms a top surface having two intersecting inclined surfaces at the upper portion of the cavity portion, The rising angle of each of the two inclined surfaces from a surface parallel to the workbench is 35° or more and less than 90°.

2. The method for manufacturing a three-dimensional object according to claim 1, characterized in that: The rising angle is greater than or equal to 35° and less than or equal to 70°.

3. The method for manufacturing a three-dimensional object according to claim 1, characterized in that: The rising angle is greater than or equal to 35° and less than or equal to 55°.

4. The method for manufacturing a three-dimensional object according to claim 1, characterized in that: In the first step, the molded object is molded so that the hollow portion is tubular and the portion facing the top surface in the stacking direction is semicircular.

5. The method for manufacturing a three-dimensional object according to claim 1, characterized in that: Each of the layers has an outermost peripheral region and an inner region connected to the inner side of the outermost peripheral region, In the second step, each of the layers is molded so that at least a portion of an outermost path for molding the outermost peripheral region overlaps with an inner path for molding the inner region.

6. The method for manufacturing a three-dimensional object according to claim 5, characterized in that: An overlap amount between the inner path and the outermost peripheral path is greater than or equal to 10% and less than or equal to 50% of a line width of the outermost peripheral path.

7. The method for manufacturing a three-dimensional object according to claim 5, characterized in that: In the second step, the layers are stacked so that the outermost path overlaps the inner path in at least a portion of the non-overlapping portion.

8. The method for manufacturing a three-dimensional object according to claim 1, characterized in that: The modeling material includes metal particles and thermoplastic resin.

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