Three-dimensional modeling device

Abstract

A three-dimensional modeling apparatus suppresses an unexpected ejection of a material from a nozzle. The three-dimensional modeling apparatus includes a melting unit that melts a material into a modeling material, and a nozzle that ejects the modeling material supplied from the melting unit toward a table. The melting unit includes a screw member that rotates around a rotation axis and has a groove forming surface on which a groove to which the material is supplied is formed, a heating unit that heats the material supplied into the groove, a barrel member that has an opposite surface opposite to the groove forming surface and is provided with a communication hole that communicates the opposite surface with the nozzle, and an ejection amount adjusting mechanism that is provided in the communication hole and adjusts a flow rate of the modeling material ejected from the nozzle.

Description

[0001] This application is a divisional application of patent application No. 202010317820.9, filed on April 21, 2020, entitled “Three-dimensional modeling device”, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0002] The present disclosure relates to a three-dimensional modeling device. BACKGROUND

[0003] For example, Patent Literature 1 discloses a three-dimensional modeling device that has a nozzle that ejects a molten material and a suction portion that suctions the material in the nozzle. In the three-dimensional modeling device, the material in the nozzle is suctioned by driving the suction portion when the nozzle is moved to a separation position after the material is ejected from the nozzle, so that a string of the material extending between a three-dimensional modeled object and the nozzle is suppressed.

[0004] Patent Literature 1: Japanese Patent Application Publication No. 2017-035811

[0005] In the above-described three-dimensional modeling device, for example, in a case where a time required for the movement of the nozzle is long, it is possible that the material is accidentally ejected from the nozzle. Therefore, there is a possibility that the material accidentally ejected from the nozzle adheres to the three-dimensional modeled object, so that the dimensional accuracy of the three-dimensional modeled object is reduced. SUMMARY

[0006] According to an aspect of the present disclosure, there is provided a three-dimensional modeling device. The three-dimensional modeling device includes a melting portion that melts a material into a modeling material, and a nozzle that ejects the modeling material supplied from the melting portion toward a worktable. The melting portion includes a spiral member that rotates around a rotation axis and has a groove forming surface on which a groove to which the material is supplied is formed, a heating portion that heats the material supplied to the groove, a barrel-shaped member that has an opposing surface opposite to the groove forming surface and is provided with a communication hole that communicates the opposing surface with the nozzle, and an ejection amount adjusting mechanism that is provided to the communication hole and adjusts a flow rate of the modeling material ejected from the nozzle. BRIEF DESCRIPTION OF DRAWINGS

[0007] Figure 1 FIG. 1 is an explanatory diagram that shows a brief configuration of a three-dimensional modeling device in a first embodiment.

[0008] Figure 2 FIG. 2 is an explanatory diagram that shows a configuration of an ejection amount adjusting mechanism and a suction portion in the first embodiment.

[0009] Figure 3 FIG. 3 is a perspective view that shows a configuration of a valve portion in the first embodiment.

[0010] Figure 4is a first explanatory view showing the operation of the valve section of the discharge amount adjusting mechanism.

[0011] Figure 5 is a second explanatory view showing the operation of the valve section of the discharge amount adjusting mechanism.

[0012] Figure 6 is an explanatory view showing the operation of the plunger of the suction section.

[0013] Figure 7 is a perspective view showing the configuration of the groove forming surface of the flat spiral.

[0014] Figure 8 is a plan view showing the configuration of the spiral opposing surface of the barrel.

[0015] Figure 9 is a flowchart showing the contents of the modeling process.

[0016] Figure 10 is an explanatory view schematically showing the case where a three-dimensional modeled object is modeled.

[0017] Figure 11 is an explanatory view showing a three-dimensional modeling apparatus in a comparative example.

[0018] Figure 12 is an explanatory view showing the outline configuration of a three-dimensional modeling apparatus in a second embodiment.

[0019] Figure 13 is an explanatory view showing the outline configuration of a three-dimensional modeling apparatus in another mode.

[0020] Explanation of Reference Numerals

[0021] 20…material supply section, 22…supply path, 30, 30c, 30d…melting section, 31…screw housing, 32…drive motor, 33…shaft, 40…flat screw, 41…upper surface, 42…groove forming surface, 43…side surface, 44…ridge portion, 45…groove portion, 46…central portion, 48…material introduction port, 50, 50b, 50c, 50d…barrel, 52, 52b…screw opposing surface, 54…guide groove, 56…communication hole, 56b…first communication hole, 57, 57d…intersection hole, 58, 58d…heater, 59…refrigerant pipe, 61…nozzle, 62…nozzle hole, 65…internal flow passage, 70, 70d…discharge amount adjusting mechanism, 73, 73d…valve portion, 75…recess, 77, 77d…operation portion, 80…suction section, 81…cylinder, 82…plunger, 90…cooling section, 100, 100b, 100c, 100d…three-dimensional modeling device, 101…valve drive section, 102…plunger drive section, 103…pump, 151…first partial flow passage, 152…second partial flow passage, 153…intersection portion, 200, 200c…modeling head, 250…flow passage structure, 256…second communication hole, 257…intersection hole, 300…work table, 310…modeling surface, 400…moving mechanism, 500…control section. DETAILED DESCRIPTION

[0022] A. First Embodiment

[0023] Figure 1 is an explanatory view showing a brief configuration of the three-dimensional modeling device 100 in the first embodiment. Figure 1 Arrows in the X, Y, Z directions are shown in the explanatory view. The X direction and the Y direction are directions in the horizontal direction, and the Z direction is a direction in the vertical direction. In other explanatory views, arrows in the X, Y, Z directions are also appropriately shown. Figure 1 The X, Y, Z directions in the explanatory view represent the same directions as the X, Y, Z directions in other explanatory views.

[0024] The three-dimensional modeling device 100 in the present embodiment is provided with a modeling head 200, a work table 300, a moving mechanism 400, and a control section 500. The three-dimensional modeling device 100, under the control of the control section 500, models a three-dimensional modeled object of a desired shape on a modeling surface 310 of the work table 300 by discharging a modeling material from a nozzle 61 provided on the modeling head 200 toward the modeling surface 310 while driving the moving mechanism 400 to change the relative position of the nozzle 61 and the modeling surface 310.

[0025] The moving mechanism 400 changes the relative position of the nozzle 61 and the molding surface 310. In the present embodiment, the moving mechanism 400 changes the relative position of the nozzle 61 and the molding surface 310 by moving the table 300 with respect to the molding head 200. The moving mechanism 400 in the present embodiment is constituted by a three-axis positioner that moves the table 300 in three axial directions of X, Y, and Z by driving forces of three motors. Each motor is driven under the control of the control section 500. Note that the moving mechanism 400 can also be constituted not by moving the table 300 but by moving the molding head 200 without moving the table 300 to change the relative position of the nozzle 61 and the molding surface 310. Further, the moving mechanism 400 can also be constituted by moving both the table 300 and the molding head 200 to change the relative position of the nozzle 61 and the molding surface 310.

[0026] The control section 500 is constituted by a computer that has one or more processors, a main storage device, and an input / output interface that inputs and outputs signals to and from the outside. In the present embodiment, the control section 500 controls the operation of the molding head 200 and the moving mechanism 400 by executing a program or an instruction read into the main storage device by the processor, thereby performing a molding process for molding a three-dimensional molded article. The operation includes movement of the three-dimensional relative position of the molding head 200 and the table 300. Note that the control section 500 can also be constituted not by a computer but by a combination of a plurality of circuits.

[0027] The molding head 200 has a material supply section 20 that is a supply source of a material, a melting section 30 that melts the material supplied from the material supply section 20 into a molding material, and a nozzle 61 that ejects the molding material supplied from the melting section 30. The material supply section 20 accommodates a material in a state of a pellet, a powder, or the like. In the present embodiment, an ABS resin formed into a pellet is used as the material. The material supply section 20 in the present embodiment is constituted by a hopper. A supply path 22 that connects between the material supply section 20 and the melting section 30 is provided below the material supply section 20. The material supply section 20 supplies the material to the melting section 30 via the supply path 22.

[0028] The melting section 30 has a screw housing 31, a drive motor 32, a planar screw 40, and a barrel 50. The melting section 30 melts at least a part of the material in a solid state supplied from the material supply section 20 into a molding material in a paste state having fluidity and supplies it to the nozzle 61. Note that the planar screw 40 is sometimes referred to simply as a screw.

[0029] The spiral member case 31 is a case that houses the planar spiral member 40. A tub member 50 is fixed to a lower surface of the spiral member case 31, and the planar spiral member 40 is housed in a space surrounded by the spiral member case 31 and the tub member 50. A drive motor 32 is fixed to an upper surface of the spiral member case 31. A shaft 33 of the drive motor 32 is connected to an upper surface 41 side of the planar spiral member 40. The drive motor 32 is driven under the control of a control section 500.

[0030] The planar spiral member 40 has a substantially cylindrical shape that is smaller in height in the direction of the central axis RX than in diameter. The planar spiral member 40 is disposed in the spiral member case 31 in such a manner that the central axis RX is parallel to the Z direction. The planar spiral member 40 is caused to rotate in the spiral member case 31 about the central axis RX by torque generated by the drive motor 32. The planar spiral member 40 has a groove formation surface 42 on the side opposite the upper surface 41 in the direction of the central axis RX, and the groove formation surface 42 has groove portions 45 to which a material to be supplied is supplied. Note that the central axis RX is sometimes referred to as a rotation axis. The specific configuration of the groove formation surface 42 will be described later.

[0031] The tub member 50 is disposed below the planar spiral member 40. The tub member 50 has a spiral member facing surface 52 that faces the groove formation surface 42 of the planar spiral member 40. The tub member 50 is provided with a communication hole 56 that communicates between the spiral member facing surface 52 and a nozzle 61, and a cross hole 57 that intersects the communication hole 56. A portion of the communication hole 56 that intersects the cross hole 57 is referred to as a cross portion 153. The communication hole 56 has a first partial flow passage 151 that is closer to the spiral member facing surface 52 than the cross portion 153, and a second partial flow passage 152 that is farther from the spiral member facing surface 52 than the cross portion 153. In the present embodiment, the first partial flow passage 151 and the second partial flow passage 152 extend in the Z direction on the central axis RX of the planar spiral member 40. The cross hole 57 extends in the Y direction. Note that the spiral member facing surface 52 is sometimes referred to simply as a facing surface. The specific configuration of the spiral member facing surface 52 will be described later.

[0032] The tub member 50 is provided with an ejection amount adjustment mechanism 70 that adjusts the flow rate of the modeling material ejected from the nozzle 61. The ejection amount adjustment mechanism 70 includes a valve portion 73 disposed in the cross hole 57, and a valve drive portion 101 that causes the valve portion 73 to rotate in the cross hole 57. The valve drive portion 101 is configured by an actuator such as a stepping motor, and causes the valve portion 73 to rotate under the control of the control section 500. A suction portion 80 is connected to the second partial flow passage 152 of the communication hole 56. The suction portion 80 sucks the modeling material from the second partial flow passage 152. Note that the valve portion 73 can also be said to rotate in the cross portion 153 of the communication hole 56. The flow rate of the modeling material ejected from the nozzle 61 is also referred to as the ejection amount. The specific configuration of the ejection amount adjustment mechanism 70 and the specific configuration of the suction portion 80 will be described later.

[0033] The tub 50 has a heater 58 that heats the material supplied to the groove portion 45 of the planar spiral 40. In the present embodiment, the heater 58 is embedded in the tub 50 as a shaft extending in the Y direction. Each of the heaters 58A to 58D is disposed below the groove portion 45 of the planar spiral 40 in the tub 50. Each of the heaters 58A to 58D is disposed so that the position of each of the heaters 58A to 58D in the Z direction is the same as the position of the valve portion 73 of the discharge amount adjustment mechanism 70 in the Z direction. From the -X direction side toward the +X direction side, the heater 58A, the heater 58B, the valve portion 73 of the discharge amount adjustment mechanism 70, the heater 58C, and the heater 58D are disposed in parallel in this order. The heater 58A and the heater 58B are disposed so that, in a cross section passing through the center axis RX of the planar spiral 40 and perpendicular to the center axis AX1 of the valve portion 73, the shortest distance between the communication hole 56 in the X direction perpendicular to the center axis RX of the planar spiral 40 and the heater 58B is equal to the shortest distance between the outer periphery of the groove formation surface 42 of the planar spiral 40 in the X direction and the heater 58A. The heater 58C and the heater 58D are disposed so that, in a cross section passing through the center axis RX of the planar spiral 40 and perpendicular to the center axis AX1 of the valve portion 73, the shortest distance between the communication hole 56 in the X direction and the heater 58C is equal to the shortest distance between the outer periphery of the groove formation surface 42 of the planar spiral 40 in the X direction and the heater 58D. The temperature of each of the heaters 58A to 58D is controlled by the control portion 500. Note that the heater 58 is also referred to as a heating portion.

[0034] The tub 50 has a cooling portion 90 that cools the planar spiral 40 and the tub 50. In the present embodiment, the cooling portion 90 has a refrigerant pipe 59 embedded in the tub 50 and a pump 103 that is connected to the refrigerant pipe 59 and supplies refrigerant to the refrigerant pipe 59. The refrigerant pipe 59 is disposed at a position farther from the communication hole 56 than the heater 58. The refrigerant pipe 59 is disposed so as to pass near the outer periphery of the groove formation surface 42 in the planar spiral 40. The refrigerant pipe 59 is disposed so that, in a cross section passing through the center axis RX of the planar spiral 40 and perpendicular to the center axis AX1 of the valve portion 73, the shortest distance between the refrigerant pipe 59 in the X direction perpendicular to the center axis RX of the planar spiral 40 and the communication hole 56 is longer than the shortest distance between the refrigerant pipe 59 in the X direction and the outer periphery of the groove formation surface 42. The pump 103 is driven under the control of the control portion 500. In the present embodiment, water is used as the refrigerant. As the refrigerant, for example, a liquid such as oil, a gas such as carbon dioxide, or the like can be used. Note that the cooling portion 90 can use a Peltier element, a heat pump, or the like.

[0035] The nozzle 61 is connected to the lower surface of the tub 50. A front end portion of the nozzle 61 opposite to the molding surface 310 of the table 300 is provided with a nozzle hole 62. The nozzle hole 62 is an opening portion for ejecting the molding material. The second portion flow passage 152 of the communication hole 56 of the tub 50 communicates with the nozzle hole 62 via the internal flow passage 65. In the present embodiment, the opening shape of the nozzle hole 62 is circular. The diameter of the nozzle hole 62 is smaller than the diameter of the internal flow passage 65. Note that the opening shape of the nozzle hole 62 is not limited to circular, and can be quadrangular or the like.

[0036] Figure 2 is a diagram showing the configuration of the suction portion 80 and the ejection amount adjustment mechanism 70 in the present embodiment. Figure 3 is a perspective view showing the configuration of the valve portion 73 of the ejection amount adjustment mechanism 70 in the present embodiment. As described above, the ejection amount adjustment mechanism 70 has the cylindrical valve portion 73 disposed in the intersection hole 57. The valve portion 73 has a central axis AX1. On the valve portion 73, a recessed portion 75 is provided by cutting a portion of the outer periphery of the cylinder into a half moon shape. The recessed portion 75 is disposed in the intersection portion 153 of the communication hole 56. An operation portion 77 is provided on the end portion of the valve portion 73 on the -Y direction side. The valve drive portion 101 is connected to the operation portion 77. By applying the torque generated by the valve drive portion 101 to the operation portion 77, the valve portion 73 is rotated. Note that the recessed portion 75 is sometimes referred to as a flow passage.

[0037] Figure 4 is a first diagram showing the operation of the valve portion 73 of the ejection amount adjustment mechanism 70. Figure 5 is a second diagram showing the operation of the valve portion 73 of the ejection amount adjustment mechanism 70. As Figure 4 indicated, when the valve portion 73 is rotated so that the recessed portion 75 is located upward, the second portion flow passage 152 is closed by the valve portion 73, and the inflow of the molding material from the first portion flow passage 151 to the second portion flow passage 152 is cut off. On the other hand, as Figure 5 indicated, when the valve portion 73 is rotated so that the recessed portion 75 faces the +X direction or the -X direction, the first portion flow passage 151 and the second portion flow passage 152 communicate, and the molding material flows from the first portion flow passage 151 to the second portion flow passage 152 at the maximum flow rate. The ejection amount adjustment mechanism 70 changes the flow passage cross-sectional area between the first portion flow passage 151 and the second portion flow passage 152 in accordance with the rotation of the valve portion 73, thereby changing the flow rate of the molding material flowing from the first portion flow passage 151 to the second portion flow passage 152.

[0038] Reference will be made to Figure 2In this embodiment, the suction unit 80 includes: a cylindrical cylinder 81 embedded in the barrel-shaped member 50, a plunger 82 housed within the cylinder 81, and a plunger drive unit 102 for moving the plunger 82 within the cylinder 81. The cylinder 81 is connected to the second part of the flow channel 152 of the connecting hole 56. The plunger drive unit 102 is composed of a motor driven under the control of the control unit 500 and a gear rack pair that converts the rotation of the motor into translational motion along the central axis AX2 of the cylinder 81. It should be noted that the plunger drive unit 102 may also be composed of a motor driven under the control of the control unit 500 and a ball screw that converts the rotation of the motor into translational motion along the central axis AX2 of the cylinder 81, or it may be composed of an actuator such as a solenoid mechanism or a piezoelectric element.

[0039] Figure 6 This is an explanatory diagram showing the operation of the plunger 82 in the suction section 80. As the plunger 82 moves toward the second flow channel 152 away from the connecting hole 56, a negative pressure is generated within the cylinder block 81, thus... Figure 6 As indicated by the middle arrow, the molding material in the second flow channel 152 is drawn into the cylinder 81. By drawing the molding material in the second flow channel 152 into the cylinder 81, the molding material in the nozzle 61 is also drawn into the second flow channel 152. Therefore, when the molding material is no longer ejected from the nozzle 61, by drawing the molding material in the second flow channel 152 into the cylinder 81, the tail of the molding material ejected from the nozzle 61 can be cut off. On the other hand, when the plunger 82 moves toward the second flow channel 152, the molding material in the cylinder 81 is forced out into the second flow channel 152 by the plunger 82. Therefore, when the molding material is ejected from the nozzle 61 again, by forcing the molding material in the cylinder 81 into the second flow channel 152, the responsiveness of the molding material ejected from the nozzle 61 can be improved. It should be noted that moving the plunger 82 away from the second flow channel 152 is also called pulling the plunger 82. Moving the plunger 82 toward the direction closer to the second flow channel 152 is also called pushing the plunger 82.

[0040] Figure 7 This is a perspective view showing the configuration of the groove forming surface 42 of the planar spiral member 40 in this embodiment. For ease of understanding of the technology, Figure 7 The planar helical element 40 shown makes it so that Figure 1 The diagram illustrates the inverted vertical positional relationship. A central portion 46, a groove 45, and a material inlet 48 are provided on the groove-forming surface 42 of the planar spiral member 40. The central portion 46 is a recess formed around the central axis Rx of the planar spiral member 40. The central portion 46 is opposite to the connecting hole 56 of the barrel-shaped member 50.

[0041] The groove portion 45 is a groove that extends in a spiral shape in an arc manner toward the outer periphery of the groove formation surface 42 with the central axis RX of the planar spiral member 40 as the center. The groove portion 45 can also be configured to extend in a involute curve shape, a spiral shape. One end of the groove portion 45 is connected to the central portion 46, and the other end of the groove portion 45 is connected to the material guide inlet 48. Adjacent groove portions 45 are divided from each other by the ridge portion 44.

[0042] The material guide inlet 48 is provided to the side surface 43 of the planar spiral member 40. The material guide inlet 48 guides the material supplied from the material supply portion 20 via the supply path 22 to the groove portion 45. Note that, in Figure 7 a configuration in which a plurality of sets of groove portions 45 and material guide inlets 48 are provided from the central portion 46 toward the outer periphery of the planar spiral member 40.

[0043] Figure 8 is a plan view showing the configuration of the spiral member facing surface 52 of the tubular member 50 in the present embodiment. As described above, the communication hole 56 that communicates with the nozzle 61 is formed in the center of the spiral member facing surface 52. A plurality of guide grooves 54 are formed on the spiral member facing surface 52 around the communication hole 56. One end of each guide groove 54 is connected to the communication hole 56, and extends in a spiral shape from the communication hole 56 toward the outer periphery of the spiral member facing surface 52. Each guide groove 54 has a function of guiding the modeling material to the communication hole 56.

[0044] Figure 9 is a flowchart showing the contents of the modeling process in the present embodiment. This process is executed by the control section 500 when the user makes a prescribed start operation on the operation panel provided to the three-dimensional modeling device 100 or a computer connected to the three-dimensional modeling device 100.

[0045] First, in step S110, the control section 500 acquires modeling data for modeling the three-dimensional object OB. The modeling data is data indicating information related to a movement path of the nozzle 61 with respect to the modeling surface 310 of the table 300, an amount of modeling material ejected from the nozzle 61, a rotational speed of the drive motor 32 that rotates the planar screw 40, a temperature of the heater 58 built in the barrel 50, and the like. The modeling data is generated, for example, by a slicer software installed in a computer connected to the three-dimensional modeling device 100. The slicer software reads in shape data indicating a shape of the three-dimensional object OB created using a three-dimensional CAD software or a three-dimensional CG software, and generates the modeling data by dividing the shape of the three-dimensional object OB into layers of a prescribed thickness. The shape data read in by the slicer software uses data in an STL format, an AMF format, or the like. The modeling data created by the slicer software is represented by G code, M code, or the like. The control section 500 acquires the modeling data from the computer connected to the three-dimensional modeling device 100, a recording medium such as a USB memory, or the like.

[0046] Next, in step S120, the control section 500 starts generating the modeling material. The control section 500 controls the rotation of the planar screw 40 and the temperature of the heater 58 in accordance with the modeling data, thereby causing the material to melt and generating the modeling material. The material supplied from the material supply section 20 is introduced into the groove portion 45 from the material introduction port 48 of the planar screw 40 by the rotation of the planar screw 40. The material introduced into the groove portion 45 is transported along the groove portion 45 to the central portion 46. The material transported in the groove portion 45 is sheared by the relative rotation of the planar screw 40 and the barrel 50 and heated by the heater 58, and at least a portion thereof melts into the modeling material in a paste-like state having fluidity. The modeling material collected in the central portion 46 is forced to the nozzle 61 from the communication hole 56. Note that the modeling material is continuously generated during this process.

[0047] In step S130, the control section 500 controls the ejection amount adjustment mechanism 70 to communicate between the first partial flow passage 151 and the second partial flow passage 152 of the communication hole 56 and start ejecting the modeling material from the nozzle 61. By starting to eject the modeling material from the nozzle 61, the modeling of the three-dimensional object OB is started.

[0048] In step S140, the control section 500 determines whether or not to stop the ejection of the modeling material from the nozzle 61. When it is not determined to stop the ejection of the modeling material from the nozzle 61 in step S140, the control section 500 continues the molding of the three-dimensional molded object OB while repeating the process of step S140 until it is determined to stop the ejection of the modeling material from the nozzle 61. On the other hand, when it is determined to stop the ejection of the modeling material from the nozzle 61 in step S140, in step S150, the control section 500 controls the ejection amount adjusting mechanism 70 to shut off the inflow of the modeling material from the first flow passage 151 to the second flow passage 152. By shutting off the inflow of the modeling material from the first flow passage 151 to the second flow passage 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 stopped, in step S155, the control section 500 controls the plunger drive section 102 to pull the plunger 82, thereby sucking the modeling material remaining in the nozzle 61 and the second flow passage 152 into the cylinder 81.

[0049] Then, in step S160, the control section 500 determines whether or not the molding of the three-dimensional molded object OB is completed. When it is determined that the molding of the three-dimensional molded object OB is completed in step S160, the control section 500 ends the process. On the other hand, when it is not determined that the molding of the three-dimensional molded object OB is completed in step S160, in step S170, the control section 500 determines whether or not to restart the ejection of the modeling material from the nozzle 61.

[0050] When it is not determined to restart the ejection of the modeling material from the nozzle 61 in step S170, the control section 500 waits for the molding of the three-dimensional molded object OB while repeating the process of step S170 until it is determined to restart the ejection of the modeling material from the nozzle 61. On the other hand, when it is determined to restart the ejection of the modeling material from the nozzle 61 in step S170, in step S180, the control section 500 connects the first flow passage 151 and the second flow passage 152 by controlling the ejection amount adjusting mechanism 70. By connecting the first flow passage 151 and the second flow passage 152, the ejection of the modeling material from the nozzle 61 is restarted. When the ejection of the modeling material from the nozzle 61 is restarted, in step S185, the control section 500 controls the plunger drive section 102 to push the plunger 82. By pushing the plunger 82, the modeling material in the cylinder 81 is discharged into the second flow passage 152, so that the ejection of the modeling material from the nozzle 61 is quickly restarted.

[0051] Figure 10 is a diagram schematically showing a case where the three-dimensional molded object OB is molded. In Figure 9After the step S185, the control section 500 returns the process to the step S140, and the modeling of the three-dimensional object OB is continued until it is determined in the step S160 that the modeling of the three-dimensional object OB is completed. In this way, the three-dimensional object OB of the desired shape is modeled on the table 300.

[0052] Figure 11 is an explanatory view of a three-dimensional modeling apparatus 100b in a comparative example. The comparative example differs from the present embodiment in that a flow passage structure 250 is provided between the tub 50b and the nozzle 61, and the discharge amount adjusting mechanism 70 and the suction section 80 are not provided to the tub 50b but are provided to the flow passage structure 250. That is, the comparative example differs from the present embodiment in that the discharge amount adjusting mechanism 70 and the suction section 80 are constituted as different units from the tub 50. As for other configurations, they are the same as those of the present embodiment unless otherwise specified. The first communication hole 56b is provided to the tub 50b. The second communication hole 256 that communicates between the first communication hole 56b of the tub 50b and the nozzle 61 and the cross hole 257 that intersects the second communication hole 256 are provided to the flow passage structure 250. The first communication hole 56b and the second communication hole 256 extend in the Z direction on the central axis RX of the planar spiral 40. The valve section 73 of the discharge amount adjusting mechanism 70 is disposed in the cross hole 257. The cylinder 81 of the suction section 80 is connected to the second communication hole 256. In the comparative example, the shortest distance L2 from the spiral opposing face 52b to the opening of the nozzle hole 62 is longer than the shortest distance LI from the spiral opposing face 52 to the opening of the nozzle hole 62 in the present embodiment. Therefore, in the comparative example, the pressure loss of the modeling material when flowing from the spiral opposing face 52b to the opening of the nozzle hole 62 is larger than the pressure loss of the modeling material when flowing from the spiral opposing face 52 to the opening of the nozzle hole 62 in the present embodiment.

[0053] According to the three-dimensional modeling apparatus 100 of the present embodiment described above, since the supply of the modeling material to the nozzle 61 can be stopped by the discharge amount adjustment mechanism 70 provided to the tub 50, the unintended discharge of the modeling material from the nozzle 61 can be suppressed. Thus, the unintended attachment of the material discharged from the nozzle 61 to the three-dimensional modeled object OB can be suppressed, and the dimensional accuracy of the three-dimensional modeled object OB can be prevented from being reduced. In particular, in the present embodiment, the tub 50 and the discharge amount adjustment mechanism 70 are configured as one unit, and thus, compared to a case where the tub 50 and the discharge amount adjustment mechanism 70 are configured as different units, the shortest distance Ll from the spiral member opposing surface 52 to the opening of the nozzle hole 62 can be set to be shorter. Thus, the pressure loss of the modeling material flowing from the spiral member opposing surface 52 to the opening of the nozzle hole 62 can be set to be smaller, and thus, the discharge amount of the modeling material from the nozzle 61 can be easily ensured. In addition, by configuring the tub 50 and the discharge amount adjustment mechanism 70 as one unit, the shortest distance between the heater 58 built in the tub 50 and the nozzle 61 can be set to be shorter, and thus, the modeling material in the second partial flow passage 152 of the communication hole 56 and the nozzle 61 can be heated by the heater 58 provided to the tub 50. Thus, compared to a case where a heater is separately provided near the second partial flow passage 152 and the nozzle 61 in order to heat the modeling material in the second partial flow passage 152 and the nozzle 61, the structure can be simplified, and the temperature of the heater 58 can be easily controlled by the control section 500.

[0054] In addition, in the present embodiment, the control section 500 rotates the valve section 73 by controlling the valve drive section 101, and thus, the start and stop of the supply of the modeling material to the nozzle 61 can be switched. Thus, the start and stop of the discharge of the modeling material from the nozzle 61 can be switched by a simple configuration.

[0055] In addition, in the present embodiment, since the outer periphery of the groove forming surface 42 of the planar spiral member 40 can be cooled by the cooling section 90, the temperature of the outer periphery of the groove forming surface 42 can be prevented from being excessively high, and the transport of the material can be prevented from being hindered. Thus, the material can be easily transported from the outer periphery of the groove forming surface 42 toward the center axis RX.

[0056] In addition, in the present embodiment, when the discharge of the modeling material from the nozzle 61 is stopped, the modeling material in the second partial flow passage 152 of the communication hole 56 can be sucked by the suction section 80. Thus, when the discharge of the modeling material from the nozzle 61 is stopped by the discharge amount adjustment mechanism 70, the discharge of the modeling material from the nozzle 61 can be more quickly stopped.

[0057] Note that, in the present embodiment, a granular ABS resin is used as the material, but as the material used in the modeling head 200, for example, a material that models a three-dimensional modeled object using a material having thermoplasticity, a metal material, a ceramic material, or the like as a main material can also be used. Here, the "main material" means a material that becomes the center of the shape of the three-dimensional modeled object, and means a material that has a content rate of 50% by weight or more in the three-dimensional modeled object. Among the above modeling materials, a material in which the main material is fused in a monomer form, and a material in which a part of the components together with the main material is fused to be in a paste form are included.

[0058] In a case where a material having thermoplasticity is used as the main material, in the melting section 30, the material is plasticized by being heated to generate a modeling material. The "plasticization" means that the material having thermoplasticity is heated to be fused. In addition, the "fusion" also means that the material having thermoplasticity is softened to exhibit fluidity by being heated to a temperature above the glass transition temperature.

[0059] As the material having thermoplasticity, for example, a thermoplastic resin material made of any one or two or more of the following can be used.

[0060] Examples of the thermoplastic resin material

[0061] Polypropylene resin (PP), polyethylene resin (PE), polyacetal resin (POM), polyvinyl chloride resin (PVC), polyamide resin (PA), acrylonitrile-butadiene-styrene resin (ABS), polylactic acid resin (PLA), polyphenylene sulfide resin (PPS), polycarbonate (PC), modified polyphenylene ether, polybutylene terephthalate, polyethylene terephthalate, and the like; general engineering plastics such as polysulfone, polyethersulfone, polyphenylene sulfide, polyarylate, polyimide, polyamide-imide, polyether-imide, and polyether-ether-ketone (PEEK).

[0062] In the material having thermoplasticity, additives such as pigments, metals, ceramics, waxes, flame retardants, antioxidants, heat stabilizers, and the like can be mixed. The material having thermoplasticity is plasticized and converted to a fused state by the rotation of the planar spiral member 40 and the heating of the heater 58 in the melting section 30. In addition, the modeling material thus generated is solidified because the temperature decreases after being ejected from the nozzle hole 62.

[0063] The material having thermoplasticity is preferably ejected from the nozzle hole 62 in a state of being completely fused by being heated to a temperature above the glass transition temperature thereof. Note that the "completely fused state" means a state in which there is no material having thermoplasticity that is not fused, and for example, in a case where the material uses a granular thermoplastic resin, means a state in which there is no solid in a granular form remaining.

[0064] In the molding head 200, instead of the above-described material having thermoplasticity, for example, a metal material can be used as a main material. In this case, it is preferable to mix a component that melts at the time of generating a molding material in a powder material obtained by forming the metal material into a powder shape and to feed it into the melting section 30.

[0065] <Example of metal material>

[0066] A single metal of magnesium (Mg), iron (Fe), cobalt (Co), chromium (Cr), aluminum (Al), titanium (Ti), copper (Cu), or nickel (Ni), or an alloy containing one or more of these metals.

[0067] <Example of alloy>

[0068] Maraging steel, stainless steel, cobalt-chromium-molybdenum alloy, titanium alloy, nickel alloy, aluminum alloy, cobalt alloy, or cobalt-chromium alloy.

[0069] In the molding head 200, instead of the above-described metal material, a ceramic material can be used as a main material. As the ceramic material, for example, oxide ceramics such as silicon dioxide, titanium dioxide, aluminum oxide, or zirconium oxide; non-oxide ceramics such as aluminum nitride; or the like can be used. As the main material, in the case where the above-described metal material or ceramic material is used, the molding material disposed on the work table 300 can also be solidified by sintering, for example, by irradiation of laser light or by use of hot air.

[0070] The powder material of the metal material or ceramic material fed into the feeding material supply section 20 can also be a mixed material obtained by mixing a single metal powder, alloy powder, or ceramic material powder. In addition, for example, the powder material of the metal material or ceramic material can be coated with the above-described thermoplastic resin or a thermoplastic resin other than this. In this case, the thermoplastic resin can also exhibit fluidity by melting in the melting section 30.

[0071] In the powder material of the metal material or ceramic material fed into the feeding material supply section 20, for example, a solvent described below can be added. The solvent can be used in combination with one or more selected from the following solvents.

[0072] <Example of solvent>

[0073] Water; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, and the like (poly)alkylene glycol monoalkyl ethers; ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, and the like (acetate esters); benzene, toluene, xylene, and the like (aromatic hydrocarbons); methyl ethyl ketone, acetone, methyl isobutyl ketone, ethyl n-butyl ketone, diisopropyl ketone, acetylacetone, and the like (ketones); ethanol, propanol, butanol, and the like (alcohols); tetraalkylammonium acetates; dimethyl sulfoxide, diethyl sulfoxide, and the like (sulfoxide solvents); pyridine, γ-picoline, 2,6-lutidine, and the like (pyridine solvents); tetraalkylammonium acetates (e.g., tetrabutylammonium acetate, and the like); ionic liquids such as diethylene glycol butyl ether acetate, and the like.

[0074] In addition, in the powder material of the metal material or the ceramic material fed to the material supply section 20, an adhesive such as the following can be added.

[0075] Examples of Adhesive

[0076] Acrylic resin, epoxy resin, silicone resin, cellulose-based resin, or other synthetic resin or PLA (poly-lactic acid), PA (polyamide), PPS (polyphenylene sulfide), PEEK (polyether ether ketone), or other thermoplastic resin.

[0077] B. Second Embodiment

[0078] Figure 12 is a diagram showing the configuration of the three-dimensional modeling apparatus 100c of the second embodiment. In the second embodiment, the configuration of the heaters 58A to 58D in the barrel 50c of the melting section 30c possessed by the modeling head 200c is different from that of the first embodiment. The other configurations are the same as those of the first embodiment shown in Figure 1

[0079] In the present embodiment, the heater 58A and the heater 58B are arranged in the barrel 50c in such a manner that, in a cross section passing through the central axis RX of the planar spiral 40 and perpendicular to the central axis AX1 of the valve section 73, the shortest distance L3 between the communication hole 56 in the X direction perpendicular to the central axis RX of the planar spiral 40 and the heater 58B is shorter than the shortest distance L4 between the outer periphery of the groove forming surface 42 of the planar spiral 40 in the X direction and the heater 58A. The heater 58C and the heater 58D are arranged in the barrel 50c in such a manner that, in a cross section passing through the central axis RX of the planar spiral 40 and perpendicular to the central axis AX1 of the valve section 73, the shortest distance L5 between the communication hole 56 in the X direction and the heater 58C is shorter than the shortest distance L6 between the outer periphery of the groove forming surface 42 of the planar spiral 40 in the X direction and the heater 58D.

[0080] ​According to the three-dimensional model creating apparatus 100c of the present embodiment described above, the shortest distance between each of the heaters 58A to 58D and the communication hole 56 can be set to be short, and the shortest distance between each of the heaters 58A to 58D and the outer periphery of the groove forming surface 42 can be set to be long. Thus, by heating from each of the heaters 58A to 58D, the material supplied into the groove 45 of the planar spiral member 40 can be melted, and the fluidity of the modeling material flowing in the communication hole 56 can be improved. In particular, in the present embodiment, the shortest distance between each of the heaters 58A to 58D and the nozzle 61 can be set to be short. Thus, by heating from each of the heaters 58A to 58D, the fluidity of the modeling material ejected from the nozzle 61 can be improved.

[0081] C. Other Embodiments

[0082] (C1) Figure 13 is a diagram showing the configuration of a three-dimensional model creating apparatus 100d in another mode. In the melting section 30, 30c of the three-dimensional model creating apparatus 100, 100c of each of the above embodiments, the heater 58 that heats the material supplied into the groove 45 of the planar spiral member 40 is embedded in the main body of the tub member 50, 50c. In contrast, as shown in Figure 13 , in the melting section 30d of the three-dimensional model creating apparatus 100d, the heater 58d that heats the material supplied into the groove 45 can also be embedded in the valve section 73d of the ejection amount adjusting mechanism 70d, instead of being embedded in the main body of the tub member 50d. The cross hole 57d provided on the tub member 50d can also extend from the side of the -Y direction side of the tub member 50d to the vicinity below the outer periphery of the +Y direction side of the groove forming surface 42 of the planar spiral member 40. The cross hole 57d can also penetrate the tub member 50d. The valve section 73d of the ejection amount adjusting mechanism 70d can also extend to the vicinity below the outer periphery of the +Y direction side of the groove forming surface 42 of the planar spiral member 40. It is preferable that the heater 58d be disposed below the groove 45 in the valve section 73d. It is preferable that the thermal conductivity of the operation section 77d of the ejection amount adjusting mechanism 70d be set to be lower than the thermal conductivity of the valve section 73d. For example, by making the material of the operation section 77d be a material having a lower thermal conductivity than the material of the valve section 73d, the thermal conductivity of the operation section 77d can be set to be lower than the thermal conductivity of the valve section 73d. The thermal conductivity of the operation section 77d can also be set to be lower than the thermal conductivity of the valve section 73d by forming a zirconia film on the operation section 77d. By setting the thermal conductivity of the operation section 77d to be lower than the thermal conductivity of the valve section 73d, the heat of the heater 58d can be inhibited from being transmitted to the valve driving section 101 via the operation section 77d. Thus, the temperature of the valve driving section 101 can be inhibited from becoming excessively high.

[0083] (C2) In the three-dimensional modeling apparatuses 100, 100c of each of the above embodiments, instead of using the valve portion 73 provided with the recess 75, a gate valve, a stop valve, a ball valve, or the like can be used in the discharge amount adjusting mechanism 70.

[0084] (C3) In the three-dimensional modeling apparatuses 100, 100c of each of the above embodiments, the suction portion 80 is provided. In contrast, the suction portion 80 can not be provided in the three-dimensional modeling apparatuses 100, 100c.

[0085] (C4) In the three-dimensional modeling apparatuses 100, 100c of each of the above embodiments, the cooling portion 90 is provided inside the barrel 50, 50c. In contrast, the cooling portion 90 can be provided outside the barrel 50, 50c. For example, the cooling portion 90 can be provided near the outer periphery of the groove formation surface 42 of the planar spiral 40 inside the spiral housing 31. The cooling portion 90 can not be provided in the three-dimensional modeling apparatuses 100, 100c.

[0086] (C5) In the three-dimensional modeling apparatuses 100, 100c of each of the above embodiments, the refrigerant pipe 59 is arranged in the barrel 50c in such a manner that, in a cross section passing through the central axis RX of the planar spiral 40 and perpendicular to the central axis AX1 of the valve portion 73, the shortest distance between the refrigerant pipe 59 in the direction perpendicular to the central axis RX of the planar spiral 40, i.e., the X direction, and the communication hole 56 is longer than the shortest distance between the refrigerant pipe 59 in the X direction and the outer periphery of the groove formation surface 42. In contrast, the refrigerant pipe 59 can be arranged in such a manner that, in a cross section passing through the central axis RX of the planar spiral 40 and perpendicular to the central axis AX1 of the valve portion 73, the shortest distance between the refrigerant pipe 59 in the direction perpendicular to the central axis RX of the planar spiral 40 and the communication hole 56 is longer than the shortest distance between the refrigerant pipe 59 in the direction perpendicular to the central axis RX of the planar spiral 40 and the outer periphery of the groove formation surface 42. For example, the refrigerant pipe 59 can be arranged in the barrel 50c in such a manner that, in a cross section passing through the central axis RX of the planar spiral 40 and perpendicular to the central axis AX1 of the valve portion 73, the shortest distance between the refrigerant pipe 59 in the X direction and the outer periphery of the groove formation surface 42 is the same as the shortest distance between the refrigerant pipe 59 in the X direction and the communication hole 56.

[0087] (C6) In the three-dimensional modeling apparatuses 100, 100c of each of the above embodiments, the melting portion 30, 30c is provided with the planar spiral 40 having a flat cylindrical shape and the barrel 50, 50c having the flat spiral facing surface 52. In contrast, the melting portion 30, 30c can be provided with a coaxial screw having an elongated shape and a barrel having a cylindrical spiral facing surface.

[0088] D. Other Aspects

[0089] The present disclosure is not limited to the above-described embodiments and can be implemented in various ways without departing from the gist thereof. For example, the present disclosure can also be implemented by the following aspects. In order to solve part or all of the technical problems of the present disclosure or in order to achieve part or all of the effects of the present disclosure, the technical features of the above-described embodiments corresponding to the technical features in the aspects described below can be appropriately replaced, combined. In addition, the technical features can be appropriately deleted as long as it is not described in the specification as a necessary feature.

[0090] (1) According to an aspect of the present disclosure, a three-dimensional modeling apparatus is provided. The three-dimensional modeling apparatus includes a melting unit that melts a material into a modeling material, and a nozzle that ejects the modeling material supplied from the melting unit toward a table. The melting unit includes a spiral member that rotates around a rotation axis and has a groove forming surface on which a groove to which the material is supplied is formed, a heating unit that heats the material supplied into the groove, a barrel member that has an opposing surface opposite to the groove forming surface and is provided with a communication hole that communicates the opposing surface with the nozzle, and an ejection amount adjustment mechanism that is provided to the communication hole and adjusts a flow rate of the modeling material ejected from the nozzle.

[0091] According to the three-dimensional modeling apparatus of this aspect, since the supply of the modeling material to the nozzle can be stopped by the ejection amount adjustment mechanism, the unintended ejection of the modeling material from the nozzle can be suppressed. Therefore, the material unintentionally ejected from the nozzle can be suppressed from adhering to the three-dimensional modeled object to reduce the dimensional accuracy of the three-dimensional modeled object.

[0092] (2) In the three-dimensional modeling apparatus of the above aspect, a control unit that controls the ejection amount adjustment mechanism can be provided. The ejection amount adjustment mechanism includes a valve unit configured to be rotatable around a central axis that intersects the communication hole and has a flow passage through which the modeling material flows. The communication hole includes a first partial flow passage that is a flow passage between the opposing surface and the valve unit, and a second partial flow passage that is a flow passage between the valve unit and the nozzle and communicates with the first partial flow passage via the flow passage. The control unit adjusts the flow rate of the modeling material ejected from the nozzle by rotating the valve unit to change the flow passage cross-sectional area of a connection portion of the flow passage and the second partial flow passage.

[0093] According to the three-dimensional modeling apparatus of this aspect, the start of the supply of the modeling material to the nozzle and the stop of the supply of the modeling material to the nozzle can be switched by the rotation of the valve unit. Therefore, the start of the ejection of the modeling material from the nozzle and the stop of the ejection of the modeling material from the nozzle can be switched by a simple configuration.

[0094] (3) In the three-dimensional modeling apparatus of the above aspect, the heating section can be disposed in the tubular member, and a shortest distance between the heating section and the communication hole of the tubular member in a direction perpendicular to the rotation axis of the spiral member can be shorter than a shortest distance between the heating section and an outer periphery of the spiral member.

[0095] According to the three-dimensional modeling apparatus of this aspect, heat from the heating section can be easily transferred to the modeling material in the communication hole. Thus, the flowability of the modeling material supplied to the nozzle via the communication hole can be improved.

[0096] (4) In the three-dimensional modeling apparatus of the above aspect, the tubular member can have a cooling section, and a shortest distance between the cooling section and the communication hole of the tubular member in a direction perpendicular to the rotation axis of the spiral member can be longer than a shortest distance between the cooling section and an outer periphery of the spiral member.

[0097] According to the three-dimensional modeling apparatus of this aspect, the outer periphery of the spiral member can be cooled by the cooling section. Thus, the material can be easily transported from the outer periphery of the spiral member toward the central axis by the rotation of the spiral member.

[0098] (5) The three-dimensional modeling apparatus of the above aspect can have a suction section connected to the communication hole between the discharge amount adjusting mechanism and the nozzle, and the suction section can suction the modeling material from the communication hole.

[0099] According to the three-dimensional modeling apparatus of this aspect, the modeling material in the communication hole between the discharge amount adjusting mechanism and the nozzle can be suctioned by the suction section. Thus, when the supply of the modeling material to the nozzle is stopped by the discharge amount adjusting mechanism, the discharge of the modeling material from the nozzle can be more quickly stopped.

[0100] The present disclosure can also be implemented in various ways other than the three-dimensional modeling apparatus. For example, it can be implemented in the form of a modeling head, a tubular member, or the like.

Claims

1. A three-dimensional modeling apparatus characterized by comprising: Possessing: a melting section that melts a material into a modeling material; and a nozzle that ejects the modeling material supplied from the melting section toward a work table, the melting section possesses: a screw member that rotates around a rotation axis and has a groove forming surface on which grooves into which the material is supplied are formed; a heating section that heats the material supplied to the grooves; a tubular member that has an opposing surface opposite the groove forming surface and is provided with a communication hole that communicates with the nozzle; and a screw member housing that houses the screw member, the melting section further possesses: an ejection amount adjusting mechanism that is provided to the communication hole and adjusts the flow rate of the modeling material ejected from the nozzle; a suction section that is connected to the communication hole between the ejection amount adjusting mechanism and the nozzle and suctions the modeling material from the communication hole; and a control section that controls the ejection amount adjusting mechanism and the suction section, in a case where the ejection of the modeling material from the nozzle is stopped, the control section controls the suction section to suction the modeling material remaining in the communication hole after controlling the ejection amount adjusting mechanism to stop the ejection of the modeling material from the nozzle, a cooling section is provided near the outer peripheral portion of the groove forming surface of the screw member inside the screw member housing, and the shortest distance between the cooling section and the communication hole of the tubular member in a direction perpendicular to the rotation axis of the screw member is longer than the shortest distance between the cooling section and the outer periphery of the screw member, the cooling section is disposed at a position farther from the communication hole than the heating section in the direction perpendicular to the rotation axis of the screw member.

2. The three-dimensional modeling apparatus according to claim 1, wherein the ejection amount adjusting mechanism possesses a valve section configured to be rotatable around a center axis that intersects the communication hole and has a flow passage through which the modeling material flows, the communication hole has a first partial flow passage that is a flow passage between the opposing surface and the valve section and a second partial flow passage that is a flow passage between the valve section and the nozzle and communicates with the first partial flow passage via the flow passage, the control section adjusts the flow rate of the modeling material ejected from the nozzle by causing the valve section to rotate to change the flow passage cross-sectional area of a connection portion of the flow passage and the second partial flow passage.

3. The three-dimensional modeling apparatus according to claim 1, wherein the heating section is disposed inside the tubular member, the heating section has a first heating section and a second heating section, the first heating section is disposed at a position closer to the communication hole than the second heating section in the direction perpendicular to the rotation axis of the screw member.

4. The three-dimensional modeling apparatus according to claim 1, wherein a first groove that is a part of the grooves of the screw member has a depth that is deeper than a second groove that is a part of the grooves and is closer to the center of the groove forming surface than the first groove. ​

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