JP2024064472A - Three-dimensional modeling device and method for manufacturing three-dimensional object - Google Patents

Abstract

A technique is provided that, when a 3D modeling device is used to model a shaped object having a pattern, can shorten the modeling time and reduce the burden on the device.
[Solution] The three-dimensional modeling device includes a plasticization unit that plasticizes a material to generate a modeling material, a nozzle having a nozzle opening and ejecting the modeling material toward a stage, a vibration imparting unit that is connected to the nozzle opening and is provided in a flow path through which the modeling material flows and that imparts vibrations to the modeling material in the flow path, and a control unit that controls the plasticization unit and the vibration imparting unit to form a three-dimensional object, and the control unit controls the vibration imparting unit to impart vibrations to the modeling material in the flow path while forming at least a portion of the outer region of the three-dimensional object.
[Selected Figure] Figure 1

Description

This disclosure relates to a three-dimensional modeling device and a method for manufacturing a three-dimensional object.

Patent Document 1 discloses a method for producing a three-dimensional pattern, which includes a forming process in which a three-dimensional pattern is formed on a base sheet using a 3D printer, and an attachment process in which the sheet on which the three-dimensional pattern is formed is attached to a predetermined surface of an article using an adhesive.

JP 2022-38975 A

When creating a model with a pattern using a three-dimensional modeling device, it can take time to create the pattern, which can extend the time it takes to complete the entire model. In addition, precise control of the nozzle position is required to create the pattern, which can increase the burden on the device.

According to a first aspect of the present disclosure, a three-dimensional modeling device is provided. The three-dimensional modeling device includes a plasticizing unit that plasticizes a material to generate a modeling material, a nozzle having a nozzle opening and discharging the modeling material toward a stage, a vibration imparting unit that is connected to the nozzle opening and is provided in a flow path through which the modeling material flows and that imparts vibration to the modeling material in the flow path, and a control unit that controls the plasticizing unit and the vibration imparting unit to form a three-dimensional object, and the control unit controls the vibration imparting unit to impart the vibration to the modeling material in the flow path while forming at least a portion of the outer region of the three-dimensional object.

According to a second aspect of the present disclosure, a method for manufacturing a three-dimensional object is provided. This manufacturing method includes a first step of plasticizing a material to generate a modeling material, and a second step of forming a three-dimensional object by ejecting the modeling material from a nozzle opening provided in a nozzle toward a stage, the second step including a step of controlling a vibration imparting unit provided in a flow path through which the modeling material flows and communicating with the nozzle opening, which imparts vibration to the modeling material in the flow path, and forming at least a part of the outer region of the three-dimensional object while imparting the vibration to the modeling material in the flow path.

FIG. 1 is an explanatory diagram showing a schematic configuration of a three-dimensional modeling apparatus. FIG. 2 is a schematic perspective view showing the configuration of a flat screw. FIG. FIG. 4 is a perspective view showing the configuration of a discharge adjustment unit. FIG. 4 is an explanatory diagram showing the configuration of a discharge adjustment unit and a suction delivery unit. FIG. 4 is a first explanatory diagram showing the operation of a butterfly valve. FIG. 4 is a second explanatory diagram showing the operation of the butterfly valve. FIG. 4 is a flowchart of a three-dimensional modeling process. FIG. 2 is an explanatory diagram illustrating a process of forming a three-dimensional object. FIG. 13 is a diagram showing a part of a movement path of a nozzle for forming an outer region. 13A and 13B are diagrams showing the results of an experiment in which vibration was applied to a modeling material. 4 is a flowchart of a pressure adjustment process. FIG. 4 is a diagram showing a nozzle movement path for forming a pattern by nozzle movement. 5A to 5C are diagrams showing examples of pressure changes of a modeling material. FIG. 13 is a diagram showing an example of an antiphase waveform that cancels out a pressure change. FIG. 4 is a diagram showing an example of a waveform for applying vibration. FIG. 4 is a diagram showing an example of a control waveform.

A. First embodiment:
Fig. 1 is an explanatory diagram showing a schematic configuration of a three-dimensional modeling apparatus 100 in a first embodiment. Fig. 1 shows arrows along X, Y, and Z directions that are orthogonal to each other. The X and Y directions are horizontal directions, and the Z direction is vertical directions. Arrows along the X, Y, and Z directions are also shown appropriately in other figures. The X, Y, and Z directions in Fig. 1 and the X, Y, and Z directions in other figures show the same directions.

The three-dimensional modeling device 100 in this embodiment includes a modeling unit 200, a stage 300, a moving mechanism 400, and a control unit 500. Under the control of the control unit 500, the three-dimensional modeling device 100 ejects modeling material from a nozzle opening 69 provided in the modeling unit 200 toward the modeling surface 310 of the stage 300, while driving the moving mechanism 400 to change the relative position between the nozzle opening 69 and the modeling surface 310, thereby forming a three-dimensional object in which layers of modeling material are stacked on the modeling surface 310. The modeling material is sometimes called a plasticized material. The detailed configuration of the modeling unit 200 will be described later.

As described above, the moving mechanism 400 changes the relative position between the nozzle opening 69 and the modeling surface 310. In this embodiment, the moving mechanism 400 supports the stage 300 and changes the relative position between the nozzle opening 69 and the modeling surface 310 by moving the stage 300 relative to the modeling unit 200. The moving mechanism 400 in this embodiment is configured with a three-axis positioner that moves the stage 300 in three axial directions, the X, Y, and Z directions, by the driving forces of three motors. Each motor is driven under the control of the control unit 500. Note that the moving mechanism 400 may be configured to change the relative position between the nozzle opening 69 and the modeling surface 310 by moving the modeling unit 200 without moving the stage 300, rather than by moving the stage 300. The moving mechanism 400 may also be configured to change the relative position between the nozzle opening 69 and the modeling surface 310 by moving both the stage 300 and the modeling unit 200.

The control unit 500 is configured by a computer equipped with one or more processors, a storage device, and an input/output interface for inputting and outputting signals from and to the outside. In this embodiment, the control unit 500 controls the operation of the modeling unit 200 and the movement mechanism 400 by the processor executing a program loaded into the storage device, and executes a three-dimensional modeling process for modeling a three-dimensional object. Note that the control unit 500 may be configured by a combination of multiple circuits instead of a computer.

The modeling unit 200 includes a material supply section 20, which is a material supply source, a drive section 35, a plasticizing section 30 that plasticizes the material supplied from the material supply section 20 to make it a modeling material, a nozzle 61 having a nozzle opening 69 that discharges the modeling material supplied from the plasticizing section 30, a discharge adjustment section 70 that adjusts the flow rate of the modeling material supplied to the nozzle 61, a pressure sensor 80 that measures the pressure of the modeling material, and a suction and delivery section 90 that sucks and delivers the modeling material. Here, "plasticization" is a concept that includes melting, and refers to changing from a solid to a fluid state. Specifically, in the case of a material that undergoes a glass transition, plasticization refers to raising the temperature of the material to or above the glass transition point. In the case of a material that does not undergo a glass transition, plasticization refers to raising the temperature of the material to or above the melting point.

The material supply unit 20 contains materials in the form of pellets, powder, etc. Examples of materials that can be used include resin materials such as ABS (acrylonitrile butadiene styrene), PEEK (polyether ether ketone), and PP (polypropylene). In this embodiment, the material supply unit 20 is configured as a hopper. Below the material supply unit 20, a supply path 22 is provided that connects the material supply unit 20 and the plasticization unit 30. The material supply unit 20 supplies material to the plasticization unit 30 via the supply path 22.

In this embodiment, the drive unit 35 includes a drive motor 36. The drive motor 36 is fixed to the upper surface of the screw case 31, which will be described later. The rotation shaft of the drive motor 36 is connected to the upper surface 41 of the flat screw 40, which will be described later. The drive motor 36 is driven under the control of the control unit 500 to rotate the flat screw 40. The drive unit 35 may include a reducer that reduces the rotation speed of the drive motor 36, and the drive motor 36 may be connected to the flat screw 40 via the reducer.

The plasticizing unit 30 includes a screw case 31, a flat screw 40, and a barrel 50. The plasticizing unit 30 plasticizes at least a portion of the solid-state material supplied from the material supply unit 20 to produce a paste-like modeling material with fluidity, and supplies the plasticized material to the nozzle 61.

The screw case 31 is a housing for housing the flat screw 40. A barrel 50 is fixed to the underside of the screw case 31, and the flat screw 40 is housed in the space enclosed by the screw case 31 and the barrel 50.

The flat screw 40 has a generally cylindrical shape with a length along the central axis RX that is smaller than the length in a direction perpendicular to the central axis RX. The flat screw 40 is arranged in the screw case 31 so that the central axis RX is parallel to the Z direction. The flat screw 40 rotates around the central axis RX within the screw case 31 due to the torque generated by the drive motor 36. The flat screw 40 has a groove forming surface 42 on which a groove portion 45 is formed on the opposite side to the top surface 41 in the direction along the central axis RX. The specific configuration of the flat screw 40 will be described later.

The barrel 50 is disposed below the flat screw 40. The barrel 50 has a screw-facing surface 52 that faces the groove forming surface 42 of the flat screw 40. The barrel 50 has an opening at the center of the screw-facing surface 52, a flow path 56 that passes through the barrel 50 along the Z direction, and a cross hole 57 that extends along the Y direction so as to cross the flow path 56. The flow path 56 communicates with the nozzle opening 69, and the modeling material flows inside it. The flow path 56 is also called a through hole. The specific configuration of the barrel 50 will be described later.

A heater 58 is embedded in the barrel 50 to heat the material supplied to the groove 45 of the flat screw 40. In this embodiment, four rod-shaped heaters 58 are arranged along the Y direction. Each heater 58 is arranged below the screw facing surface 52. The temperature of each heater 58 is controlled by the control unit 500.

A refrigerant pipe 59 through which a refrigerant flows is embedded in the barrel 50 at a position farther from the flow path 56 than the heater 58. The refrigerant pipe 59 is arranged to pass near the outer periphery of the screw facing surface 52. The refrigerant pipe 59 is connected to a refrigerant pump 103. The refrigerant pump 103 supplies refrigerant to the refrigerant pipe 59. The refrigerant pump 103 is driven under the control of the control unit 500. For example, liquids such as water and oil, or gases such as carbon dioxide can be used as the refrigerant. The refrigerant flowing through the refrigerant pipe 59 can prevent the temperatures of the flat screw 40 and the barrel 50 from becoming too high. The refrigerant pipe 59 and the refrigerant pump 103 are sometimes referred to as a cooling unit.

The discharge adjustment unit 70 is provided in the flow path 56. The discharge adjustment unit 70 adjusts the amount of modeling material discharged from the nozzle opening 69 by adjusting the opening area of the flow path 56. The discharge adjustment unit 70 includes a butterfly valve 75 and a valve drive unit 101 that rotates the butterfly valve 75. The butterfly valve 75 adjusts the flow rate of the modeling material supplied to the nozzle 61 by rotating in the flow path 56. The valve drive unit 101 is composed of an actuator such as a stepping motor, and rotates the butterfly valve 75 under the control of the control unit 500. Of the modeling material flow paths 56 formed in the barrel 50, a portion closer to the screw facing surface 52 than the butterfly valve 75 is called the first flow path 151, and a portion farther from the screw facing surface 52 than the butterfly valve 75 is called the second flow path 152. In the following, when the first flow path 151 and the second flow path 152 are referred to without distinction, they are simply called the flow path 56. The specific configuration of the discharge adjustment unit 70 will be described later.

The pressure sensor 80 is provided in the first flow path 151. The pressure sensor 80 measures the pressure of the modeling material in the first flow path 151. The value of the modeling material pressure measured by the pressure sensor 80 is transmitted to the control unit 500.

The suction and delivery unit 90 is connected to the second flow path 152. The suction and delivery unit 90 sucks the modeling material from the second flow path 152 and delivers the sucked modeling material to the second flow path 152. The specific configuration of the suction and delivery unit 90 will be described later.

The nozzle 61 is connected to the bottom surface of the barrel 50. The nozzle 61 is provided with a nozzle flow path 68 and a nozzle opening 69. The nozzle flow path 68 is a flow path provided within the nozzle 61. The nozzle flow path 68 is connected to the second flow path 152. The nozzle opening 69 is a portion with a reduced flow path cross section provided at the end of the nozzle flow path 68 that communicates with the atmosphere. The modeling material that flows from the second flow path 152 into the nozzle flow path 68 is discharged from the nozzle opening 69. The flow rate of the modeling material discharged from the nozzle opening 69 is adjusted by the discharge adjustment unit 70. The flow rate of the modeling material discharged from the nozzle 61 is also called the discharge amount.

A plate-shaped upper heater 60 is attached to the nozzle 61. The upper heater 60 is disposed above the nozzle opening 69. The upper heater 60 heats the modeling material discharged toward the modeling surface 310 of the stage 300. More specifically, the upper heater 60 heats the upper layer of the layers stacked on the modeling surface 310 of the stage 300 by discharging the modeling material from the nozzle opening 69. By heating the upper layer with the upper heater 60, the degree of adhesion between the layers can be increased. The heating temperature by the upper heater 60 is controlled by the control unit 500. In this embodiment, the upper heater 60 is controlled by the control unit 500 so that the heating temperature is set to the heating temperature specified by the user. The upper heater 60 is also referred to as a heating unit. In the figures following FIG. 1, the upper heater 60 is not illustrated.

Figure 2 is a schematic perspective view showing the configuration of the flat screw 40. In Figure 2, the position of the central axis RX of the flat screw 40 is indicated by a dashed line. As described with reference to Figure 1, the groove forming surface 42 is provided with a groove portion 45.

The central portion 47 of the groove forming surface 42 of the flat screw 40 is configured as a recess to which one end of the groove portion 45 is connected. The central portion 47 faces the flow passage 56 of the barrel 50 shown in FIG. 1. The central portion 47 intersects with the central axis RX.

The grooves 45 of the flat screw 40 form what is called a scroll groove. The grooves 45 extend in a spiral shape from the center 47 toward the outer periphery of the flat screw 40. The grooves 45 are not limited to a spiral shape, but may be in a spiral or involute curve shape, or may extend in an arc from the center toward the outer periphery. The groove forming surface 42 is provided with ridges 46 that form the side walls of the grooves 45 and extend along each groove 45.

The groove 45 continues to the material inlet 44 formed on the side surface 43 of the flat screw 40. This material inlet 44 is the portion that receives the material supplied via the supply path 22 of the material supply section 20.

Figure 2 shows an example of a flat screw 40 having three grooves 45 and three ridges 46. The number of grooves 45 and ridges 46 provided on the flat screw 40 is not limited to three. The flat screw 40 may have only one groove 45, or may have two or more grooves 45. In addition, any number of ridges 46 may be provided to match the number of grooves 45.

Figure 2 shows an example of a flat screw 40 in which the material inlet 44 is formed in three places. The number of material inlet 44 provided on the flat screw 40 is not limited to three. The flat screw 40 may have only one material inlet 44 or may have two or more material inlet 44 provided in multiple places.

Figure 3 is a top view showing the configuration of the barrel 50. As described above, a flow path 56 that communicates with the nozzle 61 is formed in the center of the screw-facing surface 52. A plurality of guide grooves 54 are formed around the flow path 56 in the screw-facing surface 52. One end of each guide groove 54 is connected to the flow path 56, and extends in a spiral shape from the flow path 56 toward the outer periphery of the screw-facing surface 52. Each guide groove 54 has the function of guiding the molding material to the flow path 56. Note that one end of the guide groove 54 does not have to be connected to the flow path 56. Also, the guide groove 54 can be omitted.

Figure 4 is a perspective view showing the configuration of the discharge adjustment unit 70 in this embodiment. Figure 5 is an explanatory diagram showing the configuration of the discharge adjustment unit 70 and the suction delivery unit 90 in this embodiment. The discharge adjustment unit 70 has a cylindrical drive shaft 73 arranged in the cross hole 57. The drive shaft 73 is rotatable around the central axis AX1. A butterfly valve 75 is formed in a part of the drive shaft 73, specifically, in a part of the drive shaft 73 located in the flow path 56. The butterfly valve 75 is formed by machining a part of the drive shaft 73 into a concave shape. The butterfly valve 75 is rotatably arranged in the flow path 56. The drive shaft 73 is provided so that the butterfly valve 75 is positioned at the position where the drive shaft 73 and the flow path 56 intersect. The butterfly valve 75 is arranged between the first flow path 151 and the second flow path 152. A coupling part 77 is provided at the end of the drive shaft 73 on the -Y direction side. A valve drive part 101 is connected to the coupling part 77. When torque is applied to the coupling 77 by the valve drive unit 101, the butterfly valve 75 formed on the drive shaft 73 rotates. The shape of the butterfly valve 75 may be any shape that adjusts the opening area of the flow path 56 by rotating within the flow path 56, and may be, for example, a plate shape or a hemispherical shape. The butterfly valve 75 is also simply called a valve.

Figure 6 is a first explanatory diagram showing the operation of the butterfly valve 75 of the discharge adjustment unit 70. Figure 7 is a second explanatory diagram showing the operation of the butterfly valve 75 of the discharge adjustment unit 70. As shown in Figure 6, when the butterfly valve 75 rotates so that the opening of the concave portion forming the butterfly valve 75 is positioned upward, the opening of the second flow path 152 is blocked by the butterfly valve 75, and the inflow of the modeling material from the first flow path 151 to the second flow path 152 is blocked. On the other hand, when the butterfly valve 75 rotates so that the concave portion of the butterfly valve 75 faces the -X direction or +X direction as shown in Figure 7, the first flow path 151 and the second flow path 152 are connected, and the modeling material flows from the first flow path 151 to the second flow path 152 at the maximum flow rate. The butterfly valve 75 rotates around a central axis AX1 along the Y direction to change the position of the concave portion, thereby changing the flow path cross-sectional area between the first flow path 151 and the second flow path 152, and adjusting the flow rate of the modeling material flowing from the first flow path 151 to the second flow path 152. Note that the discharge adjustment unit 70 may be in a form that includes, for example, a gate valve, a globe valve, or a ball valve, instead of the above-mentioned butterfly valve 75 as a valve.

As shown in FIG. 5, the suction delivery unit 90 in this embodiment includes a cylindrical cylinder 92 embedded in the barrel 50, a cylindrical plunger 93 housed in the cylinder 92, and a plunger drive unit 102 that moves the plunger 93 within the cylinder 92. The cylinder 92 is connected to the second flow path 152. The plunger drive unit 102 is configured with a stepping motor driven under the control of the control unit 500 and a rack and pinion mechanism that converts the rotation of the stepping motor into translational motion along the central axis AX2 of the cylinder 92. The plunger drive unit 102 may be configured with a stepping motor driven under the control of the control unit 500 and a ball screw mechanism that converts the rotation of the stepping motor into translational motion along the central axis AX2 of the cylinder 92, or may be configured with an actuator such as a solenoid mechanism or a piezoelectric element.

Figure 8 is an explanatory diagram showing the operation of the plunger 93 of the suction delivery unit 90. When the plunger 93 moves in a direction away from the second flow path 152, negative pressure is generated in the cylinder 92, and the modeling material in the second flow path 152 is drawn into the cylinder 92, as shown by the arrow in Figure 8. By drawing the modeling material in the second flow path 152 into the cylinder 92, the modeling material in the nozzle 61 is drawn into the second flow path 152. Therefore, when the discharge of the modeling material from the nozzle opening 69 is stopped, the modeling material in the second flow path 152 can be sucked into the cylinder 92 to cut off the tail of the modeling material discharged from the nozzle opening 69. On the other hand, when the plunger 93 moves in a direction approaching the second flow path 152, the modeling material in the cylinder 92 is pushed into the second flow path 152 by the plunger 93. Therefore, when the ejection of the modeling material from the nozzle opening 69 is resumed, the modeling material in the cylinder 92 is pushed out into the second flow path 152, thereby improving the responsiveness of the ejection of the modeling material from the nozzle opening 69. Note that moving the plunger 93 in the direction in which the modeling material is pushed out of the cylinder 92 is sometimes referred to as advancing or pushing the plunger 93. Moving the plunger 93 in the direction in which the modeling material is drawn into the cylinder 92 is sometimes referred to as retracting or pulling the plunger 93.

In this embodiment, the suction and delivery unit 90 also functions as a vibration applying unit. In the three-dimensional modeling process described later, the control unit 500 controls the suction and delivery unit 90 to continuously or stepwise change the position of the plunger 93 during modeling of the outer region of the three-dimensional model, thereby applying vibration to the modeling material in the flow path 56. For example, the control unit 500 can apply vibration to the modeling material by alternately repeating forward and backward movements of the plunger. This allows the line width of the modeling material discharged from the nozzle opening 69 to change continuously, and for example, a regular pattern in the form of a knurled or riblet shape can be formed in the outer region of the three-dimensional model. The mode of vibration is not limited to alternating forward and backward movements. For example, multiple forward movements may be performed and then multiple backward movements may be performed depending on the pattern to be modeled. In addition, a pattern such as two forward movements, one backward movement, two forward movements, and three backward movements may be repeatedly performed. Vibration can also be imparted by gradually changing the position of the plunger 93 by repeatedly moving forward and then stopping, or moving backward and then stopping.

Figure 9 is a flowchart of the three-dimensional modeling process. This process is executed by the control unit 500 when a predetermined start operation is performed by the user on an operation panel provided on the three-dimensional modeling device 100 or on a computer connected to the three-dimensional modeling device 100. The three-dimensional modeling process is executed by the control unit 500, thereby realizing a method for manufacturing a three-dimensional object.

In step S110, the control unit 500 acquires modeling data for forming a three-dimensional object. The modeling data is data that represents information on the movement path of the nozzle 61 relative to the stage 300, the amount of modeling material discharged from the nozzle 61, the target rotation speed of the drive motor 36 that rotates the flat screw 40, the target temperature of the heater 58 built into the barrel 50, and the like. The modeling data is generated, for example, by slicer software installed in a computer connected to the three-dimensional modeling device 100. The slicer software reads shape data representing the shape of a three-dimensional object created using three-dimensional CAD software or three-dimensional CG software, divides the shape of the three-dimensional object into layers of a predetermined thickness, and generates modeling data. The shape data read into the slicer software uses data in STL format, AMF format, or the like. The modeling data created by the slicer software is expressed in G code, M code, or the like. The control unit 500 acquires modeling data from a computer connected to the three-dimensional modeling device 100 or a recording medium such as a USB memory.

In step S120, the control unit 500 starts generating the modeling material. The control unit 500 generates the modeling material by plasticizing the material by controlling the rotation of the flat screw 40 and the temperature of the heater 58 built into the barrel 50. By the rotation of the flat screw 40, the material supplied from the material supply unit 20 is introduced into the groove portion 45 from the material inlet 44 of the flat screw 40. The material introduced into the groove portion 45 is transported along the groove portion 45 to the central portion 47. At least a portion of the material transported in the groove portion 45 is plasticized by shearing due to the relative rotation of the flat screw 40 and the barrel 50 and heating by the heater 58, and becomes a paste-like modeling material having fluidity. The modeling material collected in the central portion 47 is supplied to the first flow path 151 by the internal pressure generated in the central portion 47. The modeling material continues to be generated while the three-dimensional modeling process is being performed. The process of plasticizing the material to produce the modeling material is also called the first process.

After the generation of the modeling material is started in step S120, the control unit 500 starts executing a pressure adjustment process to stabilize the pressure of the modeling material in the first flow path 151 in step S125. The pressure adjustment process is executed in parallel with the modeling process while the flat screw 40 is rotating and the modeling material is being generated. The specific contents of the pressure adjustment process will be described later.

In step S130, the control unit 500 starts forming a three-dimensional object. The control unit 500 controls the moving mechanism 400 according to the forming data to change the relative position between the nozzle opening 69 and the stage 300 while discharging the forming material from the nozzle opening 69 toward the stage 300, thereby forming a three-dimensional object. When forming a three-dimensional object, the control unit 500 controls the valve driving unit 101 to rotate the butterfly valve 75, thereby connecting the first flow path 151 and the second flow path 152. When the first flow path 151 and the second flow path 152 are connected, the discharge of the forming material from the nozzle opening 69 begins. The process of forming a three-dimensional object by discharging the forming material from the nozzle opening 69 provided in the nozzle 61 toward the stage 300 is also referred to as the second process.

Figure 10 is an explanatory diagram that shows a schematic diagram of how a three-dimensional object OB is formed. The control unit 500 ejects plasticizing material from the nozzle 61 while changing the position of the nozzle 61 relative to the stage 300 in a direction along the modeling surface 310 of the stage 300, while maintaining the distance between the modeling surface 310 of the stage 300 and the nozzle 61. The plasticizing material ejected from the nozzle 61 is continuously deposited in the direction of movement of the nozzle 61.

The control unit 500 repeatedly moves the nozzle 61 to form layers L. After forming one layer L, the control unit 500 moves the position of the nozzle 61 relative to the stage 300 in the Z direction. Then, a model is formed by stacking further layers L on top of the layers L that have been formed so far.

Each layer L is composed of an outer region AR1 and an inner region AR2. The outer region AR1 is an area that affects the appearance of the three-dimensional object. The inner region AR2 is an area surrounded by the outer region AR1. The inner region AR2 is also called an infill region. In this embodiment, when forming each layer L, the control unit 500 forms the outer region AR1 first, and then forms the inner region AR2 located inside it.

In step S140 in FIG. 9, the control unit 500 determines whether the part of the three-dimensional object currently being modeled is the outer region AR1 or the inner region AR2. If the control unit 500 determines that the outer region AR1 is being formed, it controls the suction and delivery unit 90 to impart vibrations to the modeling material in the flow path 56.

Figure 11 is a diagram showing a part of the movement path of the nozzle 61 for forming the outer region. Figure 11 shows the X-Y coordinates of a part of the movement path of the nozzle 61 for forming the outer region AR1 of a cylindrical three-dimensional object. In this embodiment, the control unit 500 forms the outer region AR1 of each layer L using a path for two revolutions, the outermost circumference and one revolution inside it. The number of revolutions for forming the outer region AR1 can be set arbitrarily. Each path is composed of multiple linear partial paths connected in succession. The control unit 500 applies vibration to the modeling material when forming each revolution to form the outer region AR1. The control unit 500 may apply vibration to the modeling material while first forming the inner circumference of the outermost circumference, and then forming the outermost circumference. This makes it possible to highlight the pattern formed on the outer surface of the three-dimensional object. In other embodiments, vibration may be applied to the modeling material only when the outermost circumference is being modeled, and vibration may not be applied to the modeling material when the inner circumference is being modeled.

In step S150 in FIG. 9, the control unit 500 determines whether to stop the ejection of the modeling material from the nozzle opening 69. The control unit 500 uses the modeling data to determine whether to stop the ejection of the modeling material from the nozzle opening 69. For example, when the target position of the nozzle 61 is set to an area of the same layer L away from the area currently being modeled, or when the nozzle 61 is moved in the Z direction relative to the stage 300 to model a new layer L, the control unit 500 determines to stop the ejection of the modeling material from the nozzle 61. If it is not determined in step S150 that the ejection of the modeling material from the nozzle 61 should be stopped, the control unit 500 returns to step S140 and continues modeling the three-dimensional object.

When it is determined in step S150 that the ejection of the modeling material from the nozzle 61 is to be stopped, the control unit 500 controls the valve driving unit 101 to rotate the butterfly valve 75 in step S160, thereby making the opening area of the flow path 56 zero, thereby blocking the inflow of the modeling material from the first flow path 151 to the second flow path 152. By blocking the inflow of the modeling material from the first flow path 151 to the second flow path 152, the ejection of the modeling material from the nozzle 61 is stopped. When the ejection of the modeling material from the nozzle 61 is to be stopped, the control unit 500 controls the plunger driving unit 102 in step S165 to retract the plunger 93, thereby sucking the modeling material in the second flow path 152 into the cylinder 92. Therefore, the ejection of the modeling material from the nozzle opening 69 is promptly stopped. While the ejection of the modeling material from the nozzle opening 69 is stopped, the modeling of the three-dimensional object is stopped.

If it is determined in step S150 above that the ejection of the modeling material should be stopped during the modeling of the outer region AR1, i.e., if the ejection of the modeling material from the nozzle 61 should be stopped while the modeling material is being vibrated, the control unit 500 controls the suction delivery unit 90 in step S165 to impart vibration to the modeling material while sucking the modeling material into the cylinder 92. The control unit 500 vibrates the plunger 93 back and forth while retracting the plunger 93, thereby simultaneously sucking in the modeling material and imparting vibration to the modeling material.

In step S170, the control unit 500 determines whether or not to resume the ejection of the modeling material from the nozzle 61. If it is determined in step S170 that the ejection of the modeling material from the nozzle 61 is to be resumed, the control unit 500 controls the valve driving unit 101 to rotate the butterfly valve 75 in step S180, thereby increasing the opening area of the flow path 56, thereby communicating between the first flow path 151 and the second flow path 152 and allowing the modeling material to flow through the flow path 56. Then, in step S185, the control unit 500 controls the plunger driving unit 102 to advance the plunger 93, thereby sending the modeling material in the cylinder 92 into the second flow path 152. In this way, the ejection of the modeling material from the nozzle opening 69 is promptly resumed. The control unit 500 then returns to step S140 and resumes the formation of the three-dimensional object.

If it is determined in step S170 above that the ejection of the modeling material should be resumed in the outer region AR1 after the ejection of the modeling material was stopped, the control unit 500 controls the suction delivery unit 90 in step S185 to apply vibrations to the modeling material while ejecting the modeling material from the cylinder 92 to the flow path 56. The control unit 500 vibrates the plunger 93 back and forth while advancing the plunger 93, thereby simultaneously ejecting the modeling material from the cylinder 92 and applying vibrations to the modeling material in the flow path 56.

Figure 12 shows the results of an experiment in which vibrations were applied to the modeling material while the modeling material was being sent from the cylinder 92 to the flow path 56. Figure 12 shows the pressure change inside the cylinder 92 when the plunger 93 is advanced in stages inside the cylinder 92 to vibrate the modeling material. In the example shown in Figure 12, the pressure gradually rises while continuously changing up and down. Therefore, by advancing the plunger 93 while vibrating it, it is possible to apply vibrations to the modeling material while sending it out from the cylinder 92.

If it is not determined in step S170 of FIG. 9 that the ejection of the modeling material from the nozzle 61 should be resumed, the control unit 500 determines in step S190 whether or not to end the modeling of the three-dimensional object. The control unit 500 determines to end the modeling of the three-dimensional object when the modeling of all layers L that make up the three-dimensional object is completed. If it is not determined in step S190 that the modeling of the three-dimensional object should be terminated, the control unit 500 returns the process to step S170 and determines again whether or not to resume the ejection of the modeling material from the nozzle 61. On the other hand, if it is determined in step S190 that the modeling of the three-dimensional object should be terminated, the control unit 500 ends the three-dimensional modeling process.

Figure 13 is a flowchart of the pressure adjustment process that begins in step S125 of the three-dimensional modeling process shown in Figure 9.

In step S205, the control unit 500 sets the type of material used in forming the three-dimensional object OB, the collection time T, the target pressure value Pb, and the pressure tolerance ΔP as pressure adjustment conditions. The collection time T means the time for the pressure sensor 80 to collect the pressure value of the forming material in the first flow path 151. The target pressure value Pb means the target value of the pressure of the forming material in the first flow path 151. The pressure tolerance ΔP means the allowable range of deviation of the pressure of the forming material in the first flow path 151 from the target pressure value Pb. In this embodiment, the user uses a computer connected to the three-dimensional forming device 100 to specify the type of material, the collection time T, the target pressure value Pb, and the pressure tolerance ΔP in advance, and the type of material, the collection time T, the target pressure value Pb, and the pressure tolerance ΔP are represented in the forming data. The control unit 500 acquires the material type, collection time T, target pressure value Pb, and pressure tolerance ΔP by acquiring modeling data from a computer connected to the three-dimensional modeling device 100.

In step S210, the control unit 500 determines whether the butterfly valve 75 is open. The control unit 500 can determine whether the butterfly valve 75 is open, for example, by using information representing the discharge amount specified in the modeling data. If it is not determined that the butterfly valve 75 is open in step S210, the control unit 500 proceeds to step S255 to determine whether to end the pressure adjustment process. In this embodiment, the control unit 500 determines to end the pressure adjustment process when there is a command to stop the rotation of the flat screw 40. If it is determined to end the pressure adjustment process, the control unit 500 ends the pressure adjustment process. On the other hand, if it is not determined to end the pressure adjustment process, the control unit 500 returns to step S210 to determine again whether the butterfly valve 75 is open.

If it is determined in step S210 that the butterfly valve 75 is open, the control unit 500 acquires a pressure value P, which is the pressure value of the modeling material in the first flow path 151, using the pressure sensor 80 in step S215. The acquired pressure value P is stored in the storage device of the control unit 500. Then, in step S220, the control unit 500 determines whether the time t from the start of acquisition of the pressure value P has become equal to or greater than the collection time T. If it is not determined in step S220 that the time t has become equal to or greater than the collection time T, the control unit 500 repeats the process from step S210 to step S220 until it is determined in step S220 that the time t has become equal to or greater than the collection time T, thereby acquiring multiple samples of the pressure value P at a preset time interval. This time interval is set to, for example, 1 second. The collection time T is set to, for example, 10 seconds. In this case, the control unit 500 acquires samples of the pressure value P once per second for 10 seconds. In other words, the control unit 500 acquires 10 samples of the pressure value P within the collection time T. In addition, in step S210, the control unit 500 may determine whether a predetermined number of samples of the pressure value P have been acquired, rather than whether the time t is equal to or greater than the collection time T.

When it is determined in step S220 that the time t is equal to or greater than the collection time T, the control unit 500 calculates in step S225 the average value of the multiple pressure values P acquired within the collection time T. In this embodiment, the control unit 500 calculates the average pressure value Pave expressed by the following formula (1) using a total pressure value _ΣPn , which is the total value from the first acquired pressure value _P1 to the _nth acquired pressure value Pn, and the number N of samples of the pressure values P acquired within the collection time T.

Pave=ΣP _n /N (1)

In this embodiment, in step S225, the control unit 500 calculates the average pressure value Pave by calculating a moving average of the acquired multiple pressure values P. For example, when the control unit 500 acquires the first pressure value _P1 to the nth _pressure value _Pn , the control unit 500 calculates the average pressure value Pave by dividing the total value ( _P1 + _P2 + _P3 +...+ _Pn ) from _P1 to Pn by the number of samples N from _P1 to _Pn . After that, when the control unit 500 acquires the n+1th pressure value Pn ₊₁ , the control unit 500 calculates the average pressure value Pave by dividing the total value ( _P2 + _P3 + _P4 +...+ _Pn +Pn ₊₁ ) from the second pressure value _P2 to the n+1th pressure value Pn ₊₁ by the number of samples N.

In step S230, the control unit 500 determines whether the average pressure value Pave is within a predetermined allowable range. If the average pressure value Pave is equal to or less than a first threshold value obtained by adding the pressure allowable difference ΔP to the target pressure value Pb, and equal to or greater than a second threshold value obtained by subtracting the pressure allowable difference ΔP from the target pressure value Pb, the control unit 500 determines that the average pressure value Pave is within the allowable range. If it is determined in step S230 that the average pressure value Pave is within the allowable range, the control unit 500 advances the process to step S255 and determines whether or not to end the pressure adjustment process. On the other hand, if it is not determined in step S230 that the average pressure value Pave is within the allowable range, the control unit 500 calculates the pressure difference Pd expressed by the following formula (2) using the average pressure value Pave and the target pressure value Pb in step S235.

Pd = Pave - Pb ... (2)

In step S240, the control unit 500 determines whether the pressure difference Pd is a positive value. If it is determined in step S240 that the pressure difference Pd is a positive value, in other words, if it is determined that the average pressure value Pave is a value greater than the target pressure value Pb, the control unit 500 slows down the rotation speed of the flat screw 40 in step S245 so that the pressure difference Pd approaches 0. The rotation speed of the flat screw 40 is called the screw rotation speed. The rotation speed means the number of times an object rotates per unit time. In this embodiment, in step S240, the control unit 500 calculates a correction value for the screw rotation speed by referring to a table showing the relationship between the screw rotation speed and the pressure, and calculates a new screw rotation speed by subtracting the correction value from the current screw rotation speed. The table showing the relationship between the screw rotation speed and the pressure can be set by experiments or simulations performed in advance. The control unit 500 slows down the screw rotation speed by controlling the drive motor 36 so as to obtain the new screw rotation speed. Additionally, the control unit 500 may calculate the new screw rotation speed using a preset function rather than referring to a table.

If it is not determined in step S240 that the pressure difference Pd is a positive value, in other words, if it is determined that the average pressure value Pave is a value smaller than the target pressure value Pb, the control unit 500 increases the rotation speed of the flat screw 40 in step S250 so that the pressure difference Pd approaches 0. In this embodiment, in step S245, the control unit 500 calculates a correction value for the screw rotation speed by referring to a table showing the relationship between the screw rotation speed and pressure, and calculates a new screw rotation speed by adding the correction value to the current screw rotation speed. The control unit 500 increases the screw rotation speed by controlling the drive motor 36 to achieve the new screw rotation speed.

The control performed by the control unit 500 during the period when the discharge of the modeling material from the nozzle 61 is not stopped by the discharge adjustment unit 70 is sometimes called the first control, and the control performed by the control unit 500 during the period when the discharge of the modeling material from the nozzle 61 is stopped by the discharge adjustment unit 70 is sometimes called the second control. In this embodiment, the degree of adjustment of the rotation of the flat screw 40 in the second control is smaller than the degree of adjustment of the rotation of the flat screw 40 in the first control. The degree of adjustment of the rotation of the flat screw 40 means the magnitude of the change in the rotation speed of the flat screw 40 due to the adjustment. A small degree of adjustment of the rotation of the flat screw 40 means not only that the change in the rotation speed of the flat screw 40 due to the adjustment is small, but also that the rotation of the flat screw 40 is not adjusted.

In step S255, the control unit 500 determines whether or not to end the pressure adjustment process. As described above, in this embodiment, the control unit 500 determines to end the pressure adjustment process when there is a command to stop the rotation of the flat screw 40. If it is determined in step S255 that the pressure adjustment process is to be ended, the control unit 500 ends the pressure adjustment process. On the other hand, if it is not determined in step S255 that the pressure adjustment process is to be ended, the control unit 500 returns the process to step S210 and repeats the process from step S210 again. At that time, as described above, the control unit 500 calculates the average pressure value Pave by calculating a moving average of the multiple acquired pressure values P. Therefore, for example, when the n+1th pressure value Pn ₊₁ is acquired in step S215, in step S225, the average pressure value Pave is calculated by dividing the sum of the second pressure value _P2 to the n+1th pressure value Pn ₊₁ ( _P2 + _P3 + _P4 + ... + _Pn + Pn ₊₁ ) by the number of samples N.

14 is a diagram showing the movement path of the nozzle 61 in the case where a pattern is formed by moving the nozzle 61, rather than forming a pattern in the outer region AR1 by vibration. When forming a pattern by moving the nozzle 61, as shown in FIG. 14, it is necessary to finely adjust the position of the nozzle 61 according to the shape of the pattern. Therefore, it may take time to form the pattern part, and the modeling time until the entire modeling of the three-dimensional object is completed may be extended. In addition, fine position control of the nozzle 61 is required to form the pattern part, which puts a strain on the motor and the like provided in the moving mechanism 400. In contrast, according to the three-dimensional modeling device 100 of the present embodiment described above, the outer region of the three-dimensional object is formed while applying vibration to the modeling material, so that the pattern can be formed without finely moving the nozzle 61. Therefore, a three-dimensional object having a pattern on its outer surface can be formed in a short time. In addition, according to the present embodiment, it is not necessary to finely control the position of the nozzle 61 to form the pattern part, so that the strain on the motor and the like provided in the moving mechanism 400 can be suppressed.

The three-dimensional modeling device 100 of this embodiment also uses the suction delivery unit 90 connected to the flow path 56 as the vibration applying unit, and applies vibration to the modeling material in the flow path 56 by continuously or stepwise changing the position of the plunger 93 provided in the suction delivery unit 90. Therefore, it is possible to apply vibration to the modeling material and form a pattern on the three-dimensional object without adding a new device for applying vibration.

In addition, in this embodiment, when the control unit 500 stops the ejection of the modeling material from the nozzle 61 while the modeling material is being vibrated, the control unit 500 applies vibration while controlling the suction delivery unit 90 to suck the modeling material into the cylinder 92. This makes it possible to prevent the formation of the pattern from being interrupted when the ejection from the nozzle 61 stops.

In addition, in this embodiment, when the ejection of the modeling material is resumed after being stopped, the control unit 500 applies vibration to the modeling material while controlling the suction and delivery unit 90 to send the modeling material from the cylinder 92 to the flow path 56. This reduces the possibility that a pattern will not be formed when the ejection of the modeling material from the nozzle 61 is resumed. In particular, in this embodiment, when the ejection of the modeling material is resumed after being stopped, the control unit 500 controls the ejection adjustment unit 70 to resume the flow of the modeling material to the flow path 56, and then controls the suction and delivery unit 90 to send the modeling material from the cylinder 92 to the flow path 56 and resume the ejection of the modeling material. This makes it easier to apply vibration to the modeling material in the flow path 56 when the ejection of the modeling material from the nozzle 61 is resumed.

In addition, in this embodiment, the control unit 500 executes a pressure adjustment process that controls the rotation of the flat screw 40 so that the pressure of the modeling material detected by the pressure sensor 80 falls within a predetermined range, and while the pressure adjustment process is being executed, the outer periphery of the three-dimensional object is formed while imparting vibration to the modeling material in the flow path 56. Therefore, it is possible to impart vibration while stabilizing the pressure of the modeling material supplied to the flow path 56, which allows a pattern to be formed accurately in the outer periphery area.

B. Other embodiments:
(B1) In the above embodiment, the heating temperature of the upper heater 60 is controlled by the control unit 500 so as to be a temperature designated by the user. In contrast, the control unit 500 may control the upper heater 60 so as to heat the material at different temperatures depending on whether vibration is applied to the modeling material or not.

Whether the temperature is increased or decreased when vibration is applied compared to when vibration is not applied can be determined according to the type of material. For example, in the case of a crystalline resin such as PEEK, it may be preferable to slowly lower the temperature in order to increase the degree of crystallinity. Therefore, for example, when the material is a crystalline resin, the heating temperature when vibration is applied is set higher than the heating temperature when vibration is not applied. In contrast, in the case of an amorphous resin, the shape of the pattern can be fixed early by quickly lowering the temperature. Therefore, for example, when the material is an amorphous resin, the heating temperature when vibration is applied is set lower than the heating temperature when vibration is not applied. By controlling the upper heater 60 in this way, it is possible to prevent the pattern formed by the application of vibration from peeling off from the three-dimensional object or losing its shape.

The heating unit that heats the three-dimensional object being modeled is not limited to the upper heater 60, and may be provided, for example, within the stage 300.

(B2) In the above embodiment, the three-dimensional modeling device 100 uses the suction delivery unit 90 as a vibration applying unit that applies vibrations to the modeling material in the flow path 56. In contrast, the three-dimensional modeling device 100 may use the discharge adjustment unit 70 as a vibration applying unit. For example, the control unit 500 can apply vibrations to the modeling material in the flow path 56 by controlling the rotation of the butterfly valve 75 provided in the discharge adjustment unit 70 and changing the opening area of the flow path 56 continuously or stepwise.

(B3) In the above embodiment, the three-dimensional modeling device 100 uses the suction and delivery unit 90 as a vibration applying unit that applies vibrations to the modeling material in the flow path 56. In contrast, the three-dimensional modeling device 100 may be provided with a piezoelectric element or a diaphragm in part of the flow path 56 as a vibration applying unit. The control unit 500 can apply vibrations to the modeling material by controlling the voltage or compressed air applied to the piezoelectric element or the diaphragm so that they vibrate.

(B4) In the above embodiment, the three-dimensional modeling device 100 uses the suction delivery unit 90 as a vibration imparting unit that imparts vibrations to the modeling material in the flow path 56. In contrast, the three-dimensional modeling device 100 may use a flat screw 40 as a vibration imparting unit. For example, the control unit 500 can impart vibrations to the modeling material in the flow path 56 by continuously or stepwise changing the rotation speed of the flat screw 40.

In controlling the application of vibration to the modeling material by changing the rotation speed of the flat screw 40, the control unit 500 may not execute the pressure adjustment process described in the first embodiment, but may execute the waveform generation process described below, thereby achieving both stabilization of the pressure of the modeling material and application of vibration to the modeling material.

The waveform generation process will be described below with reference to Figures 15 to 18. First, prior to executing the three-dimensional modeling process, the control unit 500 rotates the flat screw 40 with the butterfly valve 75 open to generate modeling material, and measures the pressure change of the generated modeling material using the pressure sensor 80. Figure 15 is a diagram showing an example of the measured pressure change of the modeling material. Note that the control unit 500 may estimate the pressure change of the modeling material by measuring the rotation angle of the flat screw 40 by measuring the relationship between the pressure change of the modeling material and the rotation angle of the flat screw 40 in advance.

The control unit 500 then performs frequency analysis on the measured pressure change and generates an opposite-phase waveform that cancels out the pressure change. FIG. 16 is a diagram showing an example of an opposite-phase waveform that cancels out the pressure change. The control unit 500 stores the opposite-phase waveform thus generated in a storage device within the control unit 500. Furthermore, the control unit 500 generates a waveform for imparting vibration to the modeling material and stores it in the storage device. FIG. 17 is a diagram showing an example of a waveform for imparting vibration.

The control unit 500 synthesizes the antiphase waveform shown in FIG. 16 with the vibration waveform shown in FIG. 17 to generate a control waveform for controlling the rotation of the flat screw 40. FIG. 18 is a diagram showing an example of the control waveform thus generated. Note that the waveforms shown in FIGS. 16 to 18 may be generated not by the control unit 500 but by another computer capable of communicating with the three-dimensional modeling device 100.

After step S120 of the three-dimensional modeling process shown in FIG. 9, the control unit 500 controls the acceleration and deceleration of the rotation of the flat screw 40 based on the antiphase waveform shown in FIG. 16. This makes it possible to cancel out pressure changes in the modeling material that occur as the flat screw 40 rotates. The control unit 500 also skips the processing of step S125. In step S140, when the outer region AR1 is modeled, the control unit 500 imparts a pattern to the outer region AR1 by controlling the acceleration and deceleration of the rotation of the flat screw 40 based on the control waveform shown in FIG. 18.

As described above, by using the antiphase waveform shown in FIG. 16 and the control waveform shown in FIG. 18, the three-dimensional modeling device 100 can apply vibration while suppressing pressure changes in the modeling material by controlling the rotation of the flat screw 40. As a result, it becomes possible to form the pattern formed on the three-dimensional object with high precision.

The molding material may be subjected to vibration by a combination of two or more of the following: vibration by the suction delivery unit 90, vibration by the discharge adjustment unit 70, and vibration by the rotation of the flat screw 40.

(B5) In the above-described embodiment, in step S140 of FIG. 9, the control unit 500 determines whether the part of the three-dimensional object currently being modeled is the outer region AR1 or the inner region AR2, and if it determines that the outer region AR1 is being formed, it controls the suction and delivery unit 90 to impart vibration to the modeling material in the flow path. In response to this, the control unit 500 may analyze the modeling data and impart vibration during modeling of a movement path associated with a vibration imparting command recorded by the slicer software. For example, the vibration imparting command may be associated with part of the movement path, rather than the entire outer region AR1. In this way, a pattern can be formed in a portion of the outer region AR1.

(B6) In the three-dimensional modeling device 100 of the above-described embodiment, the plasticizing unit 30 includes a flat screw 40 having a groove forming surface 42 on its end surface, and a barrel 50 having a screw facing surface 52 on its end surface. In contrast, the plasticizing unit 30 may include an in-line screw having a long, axial outer shape with a spiral groove formed on the side of the shaft, and a barrel having a cylindrical screw facing surface.

(B7) In the three-dimensional modeling device 100 of the above-described embodiment, the pressure sensor 80 may be provided in the second flow path 152. In this case, the control unit 500 may adjust the rotation speed of the flat screw 40 using the pressure of the modeling material in the second flow path 152 measured by the pressure sensor 80.

(B8) In the above-described embodiment, in steps S165 and S185 of the three-dimensional modeling process shown in FIG. 9, the control unit 500 applies vibration to the modeling material when dispensing is stopped during modeling of the outer region AR1 or when dispensing is resumed in the outer region AR1. In contrast, the control unit 500 does not need to apply vibration to the modeling material when dispensing is stopped during modeling of the outer region AR1 and/or when dispensing is resumed in the outer region AR1.

(B9) In the above-described embodiment, the pressure adjustment process is started in step S125 of the three-dimensional modeling process shown in FIG. 9. However, the execution of the pressure adjustment process is not essential, and the process of step S125 may be omitted.

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

(1) According to a first aspect of the present disclosure, there is provided a three-dimensional modeling apparatus including: a plasticizing unit that plasticizes a material to generate a modeling material; a nozzle having a nozzle opening and discharging the modeling material toward a stage; a vibration imparting unit that is connected to the nozzle opening and is provided in a flow path through which the modeling material flows and that imparts vibrations to the modeling material in the flow path; and a control unit that controls the plasticizing unit and the vibration imparting unit to form a three-dimensional object, wherein the control unit controls the vibration imparting unit to impart the vibrations to the modeling material in the flow path while forming at least a part of an outer region of the three-dimensional object.
According to this embodiment, since at least a part of the outer region of the three-dimensional object is formed while applying vibration to the modeling material, it is possible to form a three-dimensional object having a pattern on its outer surface in a short time. In addition, since it is not necessary to precisely control the nozzle position to draw the pattern, it is possible to suppress an increase in the load on the device due to the formation of the pattern.

(2) In the three-dimensional modeling device of the above embodiment, the vibration applying unit may have a suction and delivery unit equipped with a cylinder connected to the flow path and a plunger that moves within the cylinder, and the control unit may apply the vibration to the modeling material in the flow path by continuously or stepwise changing the position of the plunger. According to this embodiment, the modeling material can be subjected to vibration by utilizing a plunger for sucking or delivering the modeling material.

(3) In the three-dimensional modeling device of the above embodiment, the control unit may apply the vibration by repeating a pattern that includes forward and backward movement of the plunger. According to this embodiment, a regular pattern can be formed in the outer region of the three-dimensional model.

(4) In the three-dimensional modeling device of the above embodiment, when the control unit stops the ejection of the modeling material from the nozzle during the period in which the vibration is being applied, the control unit may apply the vibration while controlling the suction delivery unit to suck the modeling material into the cylinder. According to this embodiment, it is possible to prevent the formation of a pattern from being interrupted when the ejection from the nozzle is stopped.

(5) In the three-dimensional modeling device of the above embodiment, when the control unit resumes the ejection of the modeling material in the outer region from a state in which the ejection of the modeling material has been stopped, the control unit may apply the vibration while controlling the suction and delivery unit to eject the modeling material from the cylinder to the flow path. According to this embodiment, it is possible to reduce the possibility that a pattern will not be formed when the ejection of the modeling material from the nozzle is resumed.

(6) In the three-dimensional modeling device of the above embodiment, a discharge adjustment unit is provided in the flow path and adjusts the amount of the modeling material discharged from the nozzle opening by adjusting the opening area of the flow path, and the control unit may control the discharge adjustment unit to resume the flow of the modeling material to the flow path, and then control the suction and delivery unit to send the modeling material from the cylinder to the flow path, thereby resuming the discharge of the modeling material. According to this embodiment, it is easy to impart vibration to the modeling material in the flow path when resuming the discharge of the modeling material from the nozzle.

(7) In the three-dimensional modeling device of the above embodiment, a pressure sensor is provided for detecting the pressure in the flow path, the plasticizing unit has a screw for plasticizing the material, and the control unit executes a pressure adjustment process for controlling the rotation of the screw so that the pressure detected by the pressure sensor falls within a predetermined range, and the control unit may control the vibration applying unit to apply the vibration to the modeling material in the flow path while performing the pressure adjustment process, thereby modeling at least a portion of the outer periphery of the three-dimensional model. According to this embodiment, the pressure of the modeling material can be stabilized, so that a pattern can be formed in the outer periphery region with high precision.

(8) The three-dimensional printing device of the above embodiment may further include a heating unit that heats the three-dimensional object being printed, and the control unit may control the heating unit to heat the three-dimensional object at different temperatures when the vibration is applied to the printing material and when the vibration is not applied. This embodiment makes it possible to increase the strength of the pattern formed by applying vibration to the printing material.

(9) In the three-dimensional modeling device of the above embodiment, the vibration applying unit may have a discharge adjustment unit that adjusts the amount of the modeling material discharged from the nozzle opening by adjusting the opening area of the flow path, and the control unit may apply the vibration to the modeling material in the flow path by changing the opening area continuously or stepwise. According to this embodiment, the vibration can be applied to the modeling material by using the discharge adjustment unit that adjusts the amount of the modeling material discharged.

(10) According to a second aspect of the present disclosure, a method for manufacturing a three-dimensional object is provided. The manufacturing method includes a first step of plasticizing a material to generate a modeling material, and a second step of forming a three-dimensional object by ejecting the modeling material from a nozzle opening provided in a nozzle toward a stage, the second step including a step of controlling a vibration imparting unit provided in a flow path through which the modeling material flows and communicating with the nozzle opening, which imparts vibration to the modeling material in the flow path, and forming at least a part of the outer region of the three-dimensional object while imparting the vibration to the modeling material in the flow path.

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

20...material supply section, 22...supply path, 30...plasticization section, 31...screw case, 35...drive section, 36...drive motor, 40...flat screw, 41...upper surface, 42...groove forming surface, 43...side, 44...material inlet, 45...groove section, 46...ridge section, 47...center, 50...barrel, 52...screw facing surface, 54...guide groove, 56...flow path, 57...cross hole, 58...heater, 59...refrigerant piping, 60...upper heater, 61...nozzle, 68...nozzle flow Path, 69... nozzle opening, 70... discharge adjustment section, 73... drive shaft, 75... butterfly valve, 77... coupling section, 80... pressure sensor, 90... suction delivery section, 92... cylinder, 93... plunger, 100... three-dimensional modeling device, 101... valve drive section, 102... plunger drive section, 103... refrigerant pump, 151... first flow path, 152... second flow path, 200... modeling unit, 300... stage, 310... modeling surface, 400... movement mechanism, 500... control section

Claims (10)

A plasticizing unit that plasticizes the material to generate a modeling material;
a nozzle having a nozzle opening and discharging the modeling material toward a stage;
a vibration imparting unit provided in a flow path through which the modeling material flows and communicates with the nozzle opening, the vibration imparting unit imparting vibration to the modeling material in the flow path;
a control unit that controls the plasticizing unit and the vibration applying unit to form a three-dimensional object;
Equipped with
The control unit controls the vibration applying unit to apply the vibration to the modeling material in the flow channel to model at least a part of an outer region of the three-dimensional object.
Three-dimensional modeling device. The three-dimensional modeling apparatus according to claim 1 ,
the vibration applying unit has a suction delivery unit including a cylinder connected to the flow path and a plunger moving within the cylinder,
The control unit applies the vibration to the modeling material in the flow path by continuously or stepwise changing the position of the plunger. The three-dimensional modeling apparatus according to claim 2,
The control unit applies the vibration by repeating a pattern including forward and backward movement of the plunger. The three-dimensional modeling apparatus according to claim 2,
A three-dimensional printing device in which, when the control unit stops ejecting the modeling material from the nozzle during the period in which the vibration is being applied, the control unit applies the vibration while controlling the suction and delivery unit to suck the modeling material into the cylinder. The three-dimensional modeling apparatus according to claim 2,
When the control unit resumes the ejection of the modeling material in the outer region from a state in which the ejection of the modeling material has been stopped, the control unit applies the vibration while controlling the suction and delivery unit to eject the modeling material from the cylinder to the flow path. The three-dimensional modeling apparatus according to claim 5 ,
a discharge adjustment unit provided in the flow path and configured to adjust an amount of the modeling material discharged from the nozzle opening by adjusting an opening area of the flow path;
The control unit controls the discharge adjustment unit to resume the flow of the modeling material to the flow path, and then controls the suction and delivery unit to send the modeling material from the cylinder to the flow path, thereby resuming the discharge of the modeling material. The three-dimensional modeling apparatus according to claim 1 ,
a pressure sensor for detecting a pressure in the flow path;
The plasticizing section has a screw for plasticizing the material,
the control unit executes a pressure adjustment process to control rotation of the screw so that the pressure detection value by the pressure sensor falls within a predetermined range;
The control unit, during execution of the pressure adjustment process, controls the vibration imparting unit to impart the vibration to the modeling material in the flow path while modeling at least a portion of the outer contour of the three-dimensional model. The three-dimensional modeling apparatus according to claim 1 ,
A heating unit that heats the three-dimensional object during modeling,
The control unit controls the heating unit so as to heat the three-dimensional object to different temperatures when the vibration is applied to the modeling material and when the vibration is not applied to the modeling material. The three-dimensional modeling apparatus according to claim 1 ,
the vibration applying unit has a discharge adjusting unit that adjusts the amount of the modeling material discharged from the nozzle opening by adjusting an opening area of the flow path,
The control unit applies the vibration to the modeling material in the flow path by changing the opening area continuously or stepwise. A first step of plasticizing a material to produce a building material;
a second step of forming a three-dimensional object by ejecting the modeling material from a nozzle opening provided in a nozzle toward a stage;
Equipped with
the second step includes a step of controlling a vibration imparting unit that is provided in a flow path through which the modeling material flows and that communicates with the nozzle opening and that imparts vibration to the modeling material in the flow path, thereby forming at least a part of an outer region of the three-dimensional object while imparting the vibration to the modeling material in the flow path;
A method for manufacturing three-dimensional objects.

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