Three-dimensional modeling device

Abstract

In a three-dimensional modeling device, the spraying amount of a plasticizing material is fast and stable. The three-dimensional modeling apparatus includes: a plasticizing unit that plasticizes a material and generates a plasticized material; the nozzle is provided with a nozzle opening and sprays the plasticized material; and a control unit that controls the plasticizing unit, the control unit performing at least one of a first operation for adjusting the amount of the plasticized material discharged from the nozzle from a first discharge amount to a second discharge amount that is larger than the first discharge amount, and a second operation for adjusting the amount of the plasticized material discharged from the nozzle from the second discharge amount. And a second operation for adjusting the rotational speed of the screw from the first speed to a second speed greater than the first speed and then to a third speed greater than the first speed and less than the second speed, the second operation being to adjust the rotational speed of the screw to a third speed greater than the first speed and less than the second speed when the discharge amount of the plasticized material from the nozzle is adjusted from the third discharge amount to a fourth discharge amount less than the third discharge amount. After the rotation speed of the screw is adjusted from the fourth speed to a fifth speed lower than the fourth speed, the rotation speed is adjusted to a sixth speed higher than the fifth speed and lower than the fourth speed.

Description

Technical Field

[0001] The invention relates to a three-dimensional modeling device. Background Art

[0002] Patent Document 1 discloses a three-dimensional modeling apparatus including a flow rate adjustment mechanism capable of controlling the amount of molten material ejected from a nozzle.

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

[0004] The three-dimensional modeling device disclosed in Patent Document 1 can adjust the ejection amount from the nozzle by adjusting the rotation angle of the butterfly valve as a flow control mechanism. However, when the ejection amount from the nozzle is controlled by the flow control mechanism, the pressure in the flow path upstream of the flow control mechanism is unstable, and sometimes it takes time for the ejection amount to stabilize. Summary of the invention

[0005] According to a first aspect of the present disclosure, a three-dimensional modeling device is provided. The three-dimensional modeling device comprises: a plasticizing unit having a screw and a motor for rotating the screw, plasticizing a material and generating a plasticized material; a nozzle having a nozzle opening and ejecting the plasticized material; and a control unit for controlling the plasticizing unit, wherein the control unit performs at least one of a first operation and a second operation, wherein the first operation is an operation in which, when the ejection amount of the plasticized material from the nozzle is adjusted from a first ejection amount to a second ejection amount greater than the first ejection amount, the rotation speed of the screw is adjusted from a first speed to a second speed greater than the first speed, and then to a third speed greater than the first speed and less than the second speed; and the second operation is an operation in which, when the ejection amount of the plasticized material from the nozzle is adjusted from a third ejection amount to a fourth ejection amount less than the third ejection amount, the rotation speed of the screw is adjusted from a fourth speed to a fifth speed less than the fourth speed, and then to a sixth speed greater than the fifth speed and less than the fourth speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 It is an explanatory diagram showing a schematic configuration of the three-dimensional modeling device in the first embodiment.

[0007] Figure 2 It is a three-dimensional diagram of the screw.

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

[0009] Figure 4 This is an explanatory diagram schematically showing how a three-dimensional object is formed.

[0010] Figure 5It is a flowchart of three-dimensional modeling processing.

[0011] Figure 6 It is an explanatory diagram showing an example of a partial shaped object.

[0012] Figure 7 It is a timing diagram of movement speed data and ejection control parameters.

[0013] Figure 8 is a graph showing simulation results of pressure changes.

[0014] Fig. 9 It is a diagram showing the time change of the rotation speed of the screw in the second embodiment.

[0015] Fig.10 This is a diagram illustrating the undershoot phenomenon.

[0016] Fig.11 It is a diagram showing the temporal change of the moving speed of the nozzle in the third embodiment.

[0017] Description of Reference Numerals

[0018] 20 ... material supply part, 22 ... supply path, 30 ... plasticizing part, 31 ... screw box, 32 ... motor, 40 ... screw, 41 ... upper surface, 42 ... lower surface of screw, 43 ... side surface, 44 ... material introduction port, 45 ... groove part, 46 ... ridge part, 47 ... center part, 50 ... cylinder, 52 ... upper surface of cylinder, 54 ... guide groove, 56 ... communication hole, 58 ... heater, 61 ... nozzle, 62 ... nozzle opening, 63 ... …front end face, 65…nozzle flow path, 69…flow path, 70…discharge control unit, 74…first drive unit, 75…suction and delivery unit, 76…branch flow path, 77…plunger, 78…second drive unit, 79…end face, 100…three-dimensional modeling device, 101…control unit, 102…processor, 103…storage device, 200…discharge unit, 210…stage, 211…modeling surface, 230…position changing unit. DETAILED DESCRIPTION

[0019] A. First Implementation Method:

[0020] Figure 1 1 is an explanatory diagram showing a schematic configuration of a three-dimensional modeling apparatus 100 in the first embodiment. Figure 1 In the figure, arrows along mutually orthogonal X, Y, and Z directions are indicated. The X, Y, and Z directions are directions along three mutually orthogonal spatial axes, namely, the X axis, the Y axis, and the Z axis, and include both directions along one side of the X axis, the Y axis, and the Z axis and the opposite direction thereof. The X axis and the Y axis are axes along the horizontal plane, and the Z axis is an axis along the vertical line. In other figures, arrows along the X, Y, and Z directions are also indicated as appropriate. Figure 1The X, Y, and Z directions in the figure represent the same directions as the X, Y, and Z directions in other figures. Hereinafter, the +Z direction is referred to as "upward" and the -Z direction is referred to as "downward".

[0021] The three-dimensional modeling device 100 comprises: a control unit 101, which controls the three-dimensional modeling device 100; a spraying unit 200, which generates and sprays plasticized material; a stage 210, which is used for modeling and serves as a base for the three-dimensional modeled object; and a position changing unit 230, which controls the spraying position of the plasticized material.

[0022] The ejection unit 200, under the control of the control unit 101, ejects the plasticized material obtained by plasticizing the solid state material and turning it into a paste onto the stage 210. The ejection unit 200 includes: a material supply unit 20, which is a supply source of the material before being converted into a plasticized material; a plasticizing unit 30, which plasticizes at least a part of the material and generates the plasticized material; a flow path 69, in which the generated plasticized material flows; a nozzle 61, which is connected to the flow path 69 and ejects the plasticized material; an ejection control unit 70, which is provided in the flow path 69; and a suction delivery unit 75, which is provided in the flow path 69. The flow path 69 is connected to a nozzle opening 62 of a nozzle 61 described later.

[0023] The material supply unit 20 contains materials in the form of granules or powder. In the present embodiment, a thermoplastic resin formed into granules is used as the material. As such a material, for example, ABS (acrylonitrile-styrene-butadiene) or PEEK (polyetheretherketone), PP (polypropylene), etc. can be used. The material supply unit 20 in the present embodiment is composed of a hopper. A supply path 22 connecting the material supply unit 20 and the plasticizing unit 30 is provided below the material supply unit 20. The material supply unit 20 supplies the material to the plasticizing unit 30 via the supply path 22.

[0024] The plasticizing section 30 includes a screw box 31, a motor 32, a screw 40, and a barrel 50. The plasticizing section 30 plasticizes at least a portion of the material supplied from the material supply section 20 to generate a paste-like plasticized material with fluidity. Then, the plasticizing section 30 supplies the generated plasticized material to the nozzle 61. "Plasticization" refers to a concept including melting, and changes from a solid to a fluid state. Specifically, in the case of a material that undergoes a glass transition, plasticization refers to setting the temperature of the material to above the glass transition point. In the case of a material that does not undergo a glass transition, plasticization refers to setting the temperature of the material to above the melting point. The screw 40 in this embodiment is sometimes also referred to as a flat screw or a scroll.

[0025] Figure 2 It is a perspective view showing a schematic structure of the screw 40 . Figure 31 is a schematic plan view showing the cylinder 50. The screw 40 has a substantially cylindrical shape in which the length in the direction along its central axis RX, that is, the axial direction is smaller than the length in the direction orthogonal to the axial direction. The screw 40 is arranged so that the central axis RX, which is the center of rotation, is parallel to the Z direction.

[0026] like Figure 1 As shown, the screw 40 is accommodated in the screw case 31. The upper surface 41 side of the screw 40 is connected to the motor 32. The screw 40 rotates in the screw case 31 by the rotational driving force generated by the motor 32. The screw 40 may be driven by the motor 32 via a speed reducer.

[0027] The rotation speed of the screw 40 is controlled by the control unit 101. When increasing the amount of plasticized material ejected from the nozzle 61, the control unit 101 increases the rotation speed of the screw 40. When decreasing the amount of plasticized material ejected from the nozzle 61, the control unit 101 decreases the rotation speed of the screw 40.

[0028] like Figure 2 As shown in FIG. 1 , a spiral groove 45 is formed on the lower surface 42 of the screw. The supply path 22 of the material supply unit 20 is connected to the groove 45 from the side 43 of the screw 40. The groove 45 is continuous to the material introduction port 44 formed on the side 43 of the screw 40. The material introduction port 44 is a portion for receiving the material supplied through the supply path 22 of the material supply unit 20. Figure 2 As shown, in this embodiment, the grooves 45 are separated by the convex strips 46 to form three grooves. In addition, the number of the grooves 45 is not limited to three, but may be 1 to 2, or may be 4 or more. The grooves 45 are not limited to the spiral shape, but may be spiral or involute curve, or may be a shape extending from the central portion 47 to the periphery in a circular arc.

[0029] like Figure 1 As shown in FIG. 1 , the barrel 50 is disposed below the screw 40. The barrel upper surface 52 faces the screw lower surface 42, and a space is formed between the groove 45 of the screw lower surface 42 and the barrel upper surface 52. Figure 3 As shown, in the barrel 50, a connecting hole 56 connected to the nozzle 61 described later is provided on the central axis RX of the screw 40. In the present embodiment, the connecting hole 56 forms a portion of the above-mentioned flow path 69. A plurality of guide grooves 54 are formed on the upper surface 52 of the barrel, and the plurality of guide grooves 54 are connected to the connecting hole 56, extending in a spiral shape from the connecting hole 56 to the periphery. In addition, one end of the guide groove 54 may not be connected to the connecting hole 56. In addition, the guide groove 54 may also be omitted. In the barrel 50, a heater 58 is built-in at a position opposite to the groove portion 45 of the screw 40. The temperature of the heater 58 is controlled by the control unit 101.

[0030] The material supplied to the groove 45 of the screw 40 is plasticized in the groove 45, and flows along the groove 45 by the rotation of the screw 40, and is guided to the central portion 47 of the screw 40 as a plasticized material. The plasticized material in a paste state showing fluidity that flows into the central portion 47 is supplied to the nozzle 61 via the connecting hole 56. In addition, in the plasticized material, all kinds of substances constituting the plasticized material may not be plasticized. The plasticized material only needs to be converted into a state having fluidity as a whole by plasticizing at least a part of the substances constituting the plasticized material.

[0031] like Figure 1 As shown, the nozzle 61 includes a nozzle flow path 65 and a front end face 63 provided with a nozzle opening 62. The nozzle flow path 65 is a flow path of the plasticized material formed in the nozzle 61, and forms a part of the above-mentioned flow path 69. The front end face 63 is a surface constituting the front end portion of the nozzle 61 that protrudes in the -Z direction toward the molding surface 211. The nozzle opening 62 is a portion where the flow path cross section of the nozzle flow path 65 is reduced, which is provided at the end of the nozzle flow path 65 on the side connected to the atmosphere, that is, the end on the side of the front end face 63. The plasticized material generated by the plasticizing section 30 is ejected from the nozzle opening 62 via the flow path 69. A heater that suppresses the temperature drop of the plasticized material ejected onto the stage 210 may also be arranged around the nozzle 61.

[0032] The ejection control unit 70 controls the ejection of the plasticized material from the nozzle 61 by controlling the opening area of ​​the flow path 69. The ejection control unit 70 in this embodiment is composed of a valve and is provided in the nozzle flow path 65. The ejection control unit 70 changes the opening of the nozzle flow path 65 by rotating in the nozzle flow path 65. The ejection control unit 70 is driven by the first drive unit 74 under the control of the control unit 101. The first drive unit 74 is composed of, for example, a stepping motor. The control unit 101 controls the opening / closing of the outflow of the plasticized material by controlling the rotation angle of the valve using the first drive unit 74.

[0033] The suction delivery section 75 has a branch flow path 76, a plunger 77, and a second drive section 78. The branch flow path 76 is connected to the flow path 69 between the ejection control section 70 and the nozzle opening 62, that is, the portion of the flow path 69 between the ejection control section 70 and the nozzle opening 62. In the present embodiment, the branch flow path 76 is formed by a cylinder connected to the nozzle flow path 65, and extends from the connection portion with the nozzle flow path 65 in the -X direction. The plunger 77 is driven by the second drive section 78 under the control of the control section 101, thereby moving in the branch flow path 76. The second drive section 78 is composed of, for example, a stepping motor, or a rack-and-pinion mechanism that converts the rotational force of the stepping motor into the translational motion of the plunger 77.

[0034] The control unit 101 changes the position of the plunger 77 by controlling the suction and delivery unit 75, thereby performing a suction operation and a delivery operation. The suction operation refers to an operation of sucking the plasticized material in the flow path 69 into the branch flow path 76. The delivery operation refers to an operation of delivering the plasticized material sucked into the branch flow path 76 to the flow path 69. In this embodiment, the control unit 101 causes the plunger 77 to retreat in a direction away from the flow path 69 during the suction operation, and causes the plunger 77 to advance in a direction close to the flow path 69 during the delivery operation.

[0035] The control unit 101 can suppress the tailing phenomenon of the plasticized material hanging down from the nozzle opening 62 in the form of a string by performing a suction operation to reduce the pressure in the flow path 69. In this case, the control unit 101 can more effectively suppress the tailing phenomenon by performing a suction operation after the opening of the nozzle flow path 65 is set to zero by the ejection control unit 70. In addition, the control unit 101 can improve the responsiveness of the plasticized material delivered from the nozzle opening 62 by performing a delivery operation to increase the pressure in the flow path 69. For example, when the control unit 101 starts to eject from the nozzle 61, it performs a delivery operation before the opening of the nozzle flow path 65 is made greater than zero by the ejection control unit 70, thereby improving the responsiveness of the delivery of the plasticized material.

[0036] The stage 210 is arranged at a position opposite to the nozzle 61. The three-dimensional modeling device 100 models a three-dimensional modeled object by ejecting plasticized material from the nozzle opening 62 to the modeling surface 211 of the stage 210 and stacking the layers. The modeling surface 211 and the area above the modeling surface 211 where the three-dimensional modeled object is modeled are also referred to as a modeling area.

[0037] The position changing unit 230 changes the relative position of the nozzle 61 and the stage 210. In the present embodiment, the position changing unit 230 moves the stage 210 relative to the nozzle 61. In addition, sometimes the change in the relative position of the nozzle 61 relative to the stage 210 is also referred to as the movement or scanning of the nozzle 61. In the present embodiment, for example, the situation of moving the stage 210 in the +X direction can also be referred to as moving the nozzle 61 in the -X direction. In addition, the relative movement speed of the nozzle 61 relative to the stage 210 is also referred to as the relative movement speed of the nozzle 61. In addition, the relative movement speed of the nozzle 61 is also referred to as the movement speed or movement speed of the nozzle 61. The position changing unit 230 in the present embodiment is composed of a three-axis positioner that uses the driving force of three motors to move the stage 210 in the three-axis directions of the X, Y, and Z directions. Each motor is driven under the control of the control unit 101. Furthermore, the position changing unit 230 may not move the stage 210 but may move the nozzle 61 without moving the stage 210. Furthermore, the position changing unit 230 may move both the stage 210 and the nozzle 61.

[0038] The control unit 101 is composed of a computer having a processor 102, a storage device 103, and an input / output interface for inputting and outputting signals to and from the outside. In the present embodiment, the control unit 101 performs various functions such as a function of performing a three-dimensional modeling process for modeling a three-dimensional modeled object by executing a program or command stored in the storage device 103 through the processor 102. In addition, the control unit 101 may be composed of a combination of multiple circuits instead of a computer.

[0039] The control unit 101 controls the ejection unit 200 and the position change unit 230 according to the molding data in the three-dimensional molding process, and molds the molding object in the molding area on the molding surface 211. The molding data includes molding path data indicating the movement path of the nozzle 61 relative to the stage 210 and ejection amount data indicating the ejection amount associated with the molding path data. The ejection amount refers to the amount of plasticized material ejected from the nozzle opening 62 per unit time.

[0040] Figure 4 1 is an explanatory diagram schematically showing how a three-dimensional object is formed in the three-dimensional modeling device 100. In the three-dimensional modeling device 100, as described above, in the plasticizing section 30, the solid material supplied to the groove 45 of the rotating screw 40 is plasticized to generate a plasticized material MM. The control section 101 sprays the plasticized material MM from the nozzle 61 while changing the position of the nozzle 61 relative to the stage 210 in the direction along the modeling surface 211 of the stage 210 while maintaining the distance between the modeling surface 211 of the stage 210 and the nozzle 61. The plasticized material MM sprayed from the nozzle 61 is continuously accumulated in the moving direction of the nozzle 61. By such scanning by the nozzle 61, a modeling portion extending linearly along the scanning path of the nozzle 61 is formed. In this way, a continuous modeling portion in the three-dimensional object is also referred to as a partial modeling object Op.

[0041] The control unit 101 repeatedly performs the above-mentioned scanning by the nozzle 61 to form a layer ML. After forming one layer ML, the control unit 101 moves the position of the nozzle 61 relative to the stage 210 in the Z direction. Then, a three-dimensional modeling object is modeled by further stacking a layer ML on the layer ML formed so far. When stacking the layers of the plasticized material, the control unit 101 sprays the plasticized material from the nozzle 61 while maintaining the distance between the nozzle 61 and the spraying target. The spraying target is the modeling surface 211 when the plasticized material is sprayed on the modeling surface 211, and is the upper surface of the already sprayed plasticized material when the plasticized material is sprayed on the already sprayed plasticized material. The distance between the nozzle 61 and the spraying target is sometimes also referred to as the gap Gp.

[0042] The width of the above-mentioned partial molding Op is also referred to as line width, and the height of the partial molding Op is also referred to as stacking pitch. The line width and stacking pitch are determined by the size of the above-mentioned gap Gp and the amount of plasticized material ejected from the nozzle 61 per unit movement amount. For example, when the gap Gp is ​​small, the plasticized material ejected from the nozzle 61 is pressed toward the ejection target by the nozzle 61 more than when the gap Gp is ​​large, so the stacking pitch becomes smaller and the line width becomes larger. The amount of plasticized material ejected from the nozzle 61 per unit movement amount is determined by the moving speed of the nozzle 61 and the ejection amount of the plasticized material.

[0043] Figure 5 3D modeling processing executed by the control unit 101. In step S110, the control unit 101 obtains shape data representing the shape of the 3D modeled object from an external computer or recording medium. The control unit 101 obtains shape data such as 3D CAD data from the outside through a network or recording medium.

[0044] In step S120, the control unit 101 generates modeling data for modeling a three-dimensional modeled object represented by the three-dimensional data based on the three-dimensional data obtained in step S110. More specifically, the control unit 101 generates the above-mentioned modeling path data and ejection amount data in step S120. In addition, in other embodiments, the control unit 101 generates modeling data instead of executing steps S110 and S120, for example, modeling data generated by an external information processing device can be obtained from the outside through a network or a recording medium.

[0045] In step S130, the control unit 101 determines the moving speed data and the ejection control parameters. The moving speed data indicates the moving speed of the nozzle 61 in each moving path included in the molding path data. The ejection control parameters refer to parameters for controlling the ejection amount of the plasticized material and the suction delivery unit 75 in each moving path. The moving speed data or ejection control parameters determined in step S130 may be included in the molding data or may be generated as data different from the molding data. In addition, the moving speed data or the ejection control parameters may also be generated by an external information processing device.

[0046] In step S140, the control unit 101 controls the ejection unit 200 and the position change unit 230 to perform molding on one of the multiple layers constituting the three-dimensional molded object based on the molding data generated in step S120 and the moving speed data and the ejection control parameters generated in step S130. More specifically, in step S140, the control unit 101 performs molding on one or more partial molded objects constituting one layer of the three-dimensional molded object in the molding area on the molding surface 211. In step S140, the control unit 101 controls the ejection control unit 70 and sets the nozzle flow path 65 to a fully open state, and adjusts the ejection amount of the plasticized material and performs molding of the layer by controlling the rotation speed of the screw 40 and controlling the plunger 77 by the suction and delivery unit 75.

[0047] In step S150, the control unit 101 determines whether the modeling of all layers of the three-dimensional modeled object is completed. If the control unit 101 determines that the modeling of all layers of the three-dimensional modeled object is not completed, the control unit 101 returns the process to step S140 to perform the modeling of the next layer. If the control unit 101 determines that the modeling of all layers is completed, the three-dimensional modeling process ends.

[0048] Figure 6 : is an explanatory diagram showing an example of a part of the shaped object in this embodiment. Figure 6 In FIG. 1 , a portion of a partial object Op forming a layer of a three-dimensional object is schematically shown. Figure 6 In FIG. 1 , as shaping sections for shaping a partial shaping object Op, a first shaping section Sc1 , a second shaping section Sc2 , and a third shaping section Sc3 are shown.

[0049] Figure 7 2 is a timing diagram for explaining the movement speed data and the ejection control parameters in this embodiment. Figure 7 The coordinate diagram is shown in FIG. Figure 6 The illustrated partial molded object Op is molded with time changes in the moving speed of the nozzle 61, the ejection amount, the rotation speed of the screw 40, and the position of the plunger 77.

[0050] In this embodiment, the control unit 101 controls the position changing unit 230 based on the moving speed data, and can change the moving speed of the nozzle 61 to at least the first moving speed v1 and the second moving speed v2. The second moving speed v2 is a moving speed greater than the first moving speed v1. Figure 6When the curved shaping sections Sc1 and Sc3 are shaped, the moving speed of the nozzle 61 is set to the first moving speed v1, and when the linear shaping section Sc2 is shaped, the moving speed of the nozzle 61 is set to the second moving speed v2. Figure 7 Before the timing t1 shown, the shaping section Sc1 is shaped, from the timing t1 to the timing t4, the shaping section Sc2 is shaped, and after the timing t4, the shaping section Sc3 is shaped. From the timing t1 to the timing t2 is an acceleration section in which the moving speed of the nozzle 61 is accelerated, and from the timing t3 to the timing t4 is a deceleration section in which the moving speed of the nozzle 61 is decelerated.

[0051] The control unit 101 increases the amount of plasticized material ejected from the nozzle 61 as the moving speed of the nozzle 61 increases, thereby suppressing the variation in the width of the plasticized material accumulated on the stage 210. Figure 7 As shown, the control unit 101 sets the ejection amount to the first ejection amount F1 when the moving speed of the nozzle 61 is the first moving speed v1, and sets the ejection amount to the second ejection amount F2 when the moving speed of the nozzle 61 is the second moving speed v2. The second ejection amount F2 is an ejection amount larger than the first ejection amount F1.

[0052] The control unit 101 adjusts the ejection amount of the plasticized material by controlling the rotation speed of the screw 40. In the present embodiment, the control unit 101 adjusts the ejection amount of the plasticized material from the nozzle 61 from the first ejection amount F1 to the second ejection amount F2 based on the ejection control parameter, and performs a "first operation" of adjusting the rotation speed of the screw 40 from the first speed R1 to the second speed R2 and then to the third speed. The second speed R2 is a speed greater than the first speed. The third speed R3 is a speed greater than the first speed R1 and less than the second speed R2.

[0053] In addition, the control unit 101 performs a "second operation" of adjusting the rotation speed of the screw 40 from the fourth speed R4 to the fifth speed R5 and then to the sixth speed R6, while adjusting the ejection amount of the plasticized material from the nozzle 61 from the third ejection amount F3 to the fourth ejection amount F4 smaller than the third ejection amount F3 based on the ejection control parameter. The fifth speed R5 is a speed smaller than the second speed R2. The sixth speed R6 is a speed greater than the fifth speed R5 and smaller than the fourth speed R4. In addition, in the present embodiment, the third ejection amount F3 is equal to the second ejection amount F2, and the fourth ejection amount F4 is equal to the first ejection amount F1. In addition, the fourth speed R4 is equal to the third speed R3, and the sixth speed R6 is equal to the first speed R1.

[0054] like Figure 7As shown, in this embodiment, the control unit 101 performs the above-mentioned first operation in the acceleration interval in which the relative moving speed of the nozzle 61 accelerates from the first moving speed v1 to the second moving speed v2. In addition, the control unit 101 performs the above-mentioned second operation in the deceleration interval in which the relative moving speed of the nozzle 61 decelerates from the second moving speed v2 to the first moving speed v1.

[0055] The control unit 101 controls the suction and delivery unit 75 to move the plunger 77 in the branch flow path 76, thereby performing a delivery operation of delivering the plasticized material from the branch flow path 76 to the flow path 69 in the acceleration interval, and performing a suction operation of sucking the plasticized material from the flow path 69 to the branch flow path 76 in the deceleration interval. In other words, the control unit 101 performs an operation of pressing the plunger 77 to make it approach the flow path 69 in the acceleration interval, and performs an operation of pulling the plunger 77 to make it away from the flow path 69 in the deceleration interval. Figure 7 The plunger position shown shows Figure 1 The position coordinates of the end surface 79 on the +X direction side of the plunger 77 in the X direction are shown. Figure 7 In the case where the plunger position is zero, the end surface 79 of the plunger 77 is located at the closest position to the flow path 69.

[0056] In the present embodiment, the control unit 101 matches the first movement amount D1, which is the movement amount of the plunger 77 in the acceleration section, with the second movement amount D2, which is the movement amount of the plunger 77 in the deceleration section. Figure 7 , the hatched lines indicate the first movement amount D1 and the second movement amount D2, respectively. In the present disclosure, matching means that the difference between the first movement amount D1 and the second movement amount D2 is within a range of 10%. In addition, the difference between the first movement amount D1 and the second movement amount D2 is more preferably within a range of 5%. The first movement amount D1 and the second movement amount D2 are more preferably consistent.

[0057] In the present embodiment, when the control unit 101 performs the first operation in the acceleration interval, before the timing at which the rotation speed of the screw 40 reaches the second speed R2, the control unit 101 performs a process of sending an operation command for moving the plunger 77 to the suction and delivery unit 75. Specifically, in the present embodiment, the control unit 101 sends an operation command for causing the plunger 77 to perform the delivery operation to the suction and delivery unit 75 simultaneously with the timing t1 at which the acceleration of the rotation speed is started.

[0058] In the present embodiment, when the control unit 101 performs the second operation in the deceleration zone, before the timing at which the rotation speed of the screw 40 reaches the fifth speed R5, the control unit 101 performs a process of sending an operation command for moving the plunger 77 to the suction delivery unit 75. Specifically, in the present embodiment, the control unit 101 sends an operation command for causing the plunger 77 to perform the suction operation to the suction delivery unit 75 simultaneously with the timing t3 at which the deceleration of the rotation speed is started.

[0059] In the storage device 103 of the control unit 101, the moving speed of the nozzle 61, the ejection amount, the rotation speed of the screw 40, and the position of the plunger 77 are stored in a manner having Figure 7 In step S130, the control unit 101 determines the moving speed data and the ejection control parameters by using the function or map stored in the storage device 103, thereby controlling the ejection of the plasticized material so that the line width does not change even if the moving speed of the nozzle 61 changes.

[0060] Figure 8 : is a graph showing the simulation result of the pressure change of the flow path 69 based on the above-mentioned first operation. Figure 8 , the experimental results of performing the above-mentioned first operation on the rotation speed of the screw 40 are shown, and the experimental results of performing an operation different from the first operation, in which the rotation speed of the screw 40 is directly changed from the first speed R1 to the third speed R3 without passing through the second speed R2, are shown as comparative examples. In the comparative example, even if the rotation speed of the screw 40 is increased from the first speed to the third speed, the pressure of the plasticized material in the flow channel 69 does not rise immediately, but rises steadily. In contrast, by the first operation, before the rotation speed of the screw 40 is changed from the first speed R1 to the third speed R3, it is temporarily changed to the second speed R2 which is greater than the first speed R1 and the third speed R3, and as a result, the pressure of the plasticized material in the flow channel 69 rises very quickly compared with the comparative example, and then quickly stabilizes.

[0061] The three-dimensional modeling device 100 of the present embodiment described above performs the first operation when the ejection amount of the plasticized material is adjusted from the first ejection amount to the second ejection amount larger than the first ejection amount. In the first operation, after the rotation speed of the screw 40 is adjusted from the first speed R1 to the second speed R2 larger than the first speed R1, it is adjusted to the third speed R3 larger than the first speed R1 and smaller than the second speed R2. Therefore, when the ejection amount is increased, the ejection amount can be quickly stabilized. In addition, the three-dimensional modeling device 100 performs the second operation when the ejection amount of the plasticized material is adjusted from the third ejection amount to the fourth ejection amount smaller than the third ejection amount. In the second operation, after the rotation speed of the screw 40 is adjusted from the fourth speed R4 to the fifth speed R5 smaller than the fourth speed R4, it is adjusted to the sixth speed R6 larger than the fifth speed R5 and smaller than the fourth speed R4. Therefore, when the ejection amount is reduced, the ejection amount can be quickly stabilized.

[0062] In addition, the three-dimensional modeling device 100 of the present embodiment performs an operation of performing a first operation in an acceleration interval in which the relative moving speed of the nozzle 61 is accelerated from the first moving speed v1 to the second moving speed v2, and performs an operation of performing a second operation in a deceleration interval in which the second moving speed v2 is decelerated to the first moving speed v1. Then, the three-dimensional modeling device 100 performs an operation of delivering the plasticized material from the branch flow path 76 to the flow path 69 in the acceleration interval and an operation of sucking the plasticized material from the flow path 69 to the branch flow path 76 in the deceleration interval by moving the plunger 77 in the branch flow path 76. At this time, the three-dimensional modeling device 100 matches the movement amount of the plunger 77 in the acceleration interval with the movement amount of the plunger 77 in the deceleration interval. As a result, it is possible to suppress the deviation between the movement amount of the plunger 77 in the direction of approaching the flow path 69 and the movement amount of the plunger 77 in the direction of moving away from the flow path 69. As a result, the position of the plunger 77 can be controlled with high precision for a long time. As a result, the modeling accuracy of the three-dimensional modeling object can be improved.

[0063] In addition, when the three-dimensional modeling device 100 of the present embodiment performs the first operation in the acceleration section, before the timing of changing the rotation speed of the screw 40 to the second speed R2, the processing of sending the operation command for moving the plunger 77 to the suction delivery unit 75 is executed. Therefore, when the nozzle 61 is accelerated, the plasticized material can be quickly supplied to the flow path 69. As a result, it is possible to suppress the situation where the discharge amount is insufficient and the line width temporarily becomes thinner when the nozzle 61 is accelerated. In addition, when the three-dimensional modeling device 100 performs the second operation in the deceleration section, before the timing of changing the rotation speed of the screw 40 to the fifth speed R5, the processing of sending the operation command for moving the plunger 77 to the suction delivery unit 75 is executed. Therefore, when the nozzle 61 is decelerated, the plasticized material can be quickly sucked from the flow path 69. As a result, it is possible to suppress the situation where the discharge amount becomes excessive and the line width temporarily becomes thicker when the nozzle 61 is decelerated.

[0064] B. Second Implementation Method:

[0065] The configuration of the three-dimensional modeling apparatus 100 in the second embodiment is the same as that of the three-dimensional modeling apparatus 100 in the first embodiment. The first and second embodiments differ in the control content of the rotation speed of the screw 40 in the first operation, and the other control contents are the same as those in the first embodiment.

[0066] Fig. 9 1 is a diagram showing the time variation of the rotation speed of the screw 40 in the second embodiment. In the second embodiment, the control unit 101 adjusts the rotation speed of the screw 40 from the first speed R1 to the second speed R2 in the first operation, then adjusts it to the seventh speed R7 which is smaller than the second speed R2 and larger than the third speed R3, and then adjusts it from the seventh speed R7 to the third speed R3.

[0067] According to the second embodiment described above, since the rotation speed of the screw 40 can be gradually reduced from the second speed R2 to the third speed R3 via the seventh speed R7, it is possible to suppress the occurrence of the following problems when the rotation speed of the screw 40 is reduced from the second speed R2 to the third speed R3: Fig.10 Therefore, when the rotation speed of the screw 40 is reduced in the first operation, the ejection amount can be quickly stabilized.

[0068] In addition, in the present embodiment, the control unit 101 reduces the rotation speed of the screw 40 from the second speed R2 to the third speed R3 via the seventh speed R7. That is, the control unit 101 reduces the rotation speed of the screw 40 in two stages. In contrast, the control unit 101 may reduce the rotation speed of the screw 40 in three or more stages.

[0069] In addition, if Fig. 9As shown by the dotted line in FIG. 1 , the control unit 101 may adjust the rotation speed of the screw 40 from the fourth speed R4 to the fifth speed R5, then to the eighth speed R8 which is greater than the fifth speed R5 and less than the sixth speed R6, and then adjust the rotation speed from the eighth speed R8 to the sixth speed R6 in the second operation. Thus, when the rotation speed of the screw 40 is increased from the fifth speed R5 to the sixth speed R6, it is easy to stabilize the discharge amount.

[0070] C. Third Implementation Method:

[0071] The configuration of the three-dimensional modeling apparatus 100 in the third embodiment is the same as that of the three-dimensional modeling apparatus 100 in the first embodiment. In the third embodiment, the control of the moving speed of the nozzle 61 is different from that in the first embodiment.

[0072] Fig.11 is a diagram showing the time variation of the moving speed of the nozzle 61 in the third embodiment. Fig.11 As shown, the control unit 101 accelerates the relative movement speed of the nozzle 61 from the first movement speed v1 to the second movement speed v2, and then further accelerates to the third movement speed v3 which is greater than the second movement speed v2. That is, in the third embodiment, the control unit 101 increases the movement speed of the nozzle 61 multiple times.

[0073] In the case where the moving speed of the nozzle 61 is increased multiple times in this way, when the control unit 101 decelerates the moving speed of the nozzle 61 from the third moving speed v3 to the first moving speed v1, the control unit 101 does not reduce the moving speed directly from the third moving speed v3 to the first moving speed v1, but instead temporarily decelerates the moving speed from the third moving speed v3 to the second moving speed v2, and then decelerates from the second moving speed v2 to the first moving speed v1.

[0074] In the third embodiment, similarly to the first embodiment, the control unit 101 moves the plunger 77 in the branch flow path 76 to perform the operation of delivering the plasticized material from the branch flow path 76 to the flow path 69 in the acceleration section and the operation of sucking the plasticized material from the flow path 69 to the branch flow path 76 in the deceleration section. When the plunger 77 is controlled in this way, as shown in FIG. Fig.11 As shown in FIG. 1 , if the nozzle 61 is decelerated in stages in the same manner as when accelerating, the total amount of movement of the plunger 77 in the acceleration section can be easily matched with the total amount of movement of the plunger 77 in the deceleration section. As a result, it is possible to suppress the deviation between the amount of movement of the plunger 77 in the direction approaching the flow path 69 and the amount of movement of the plunger 77 in the direction away from the flow path 69. As a result, even when the moving speed of the nozzle 61 is changed in multiple stages, the position of the plunger 77 can be controlled with high precision for a long period of time. As a result, the molding precision of the three-dimensional molded object can be improved.

[0075] D. Other implementation methods:

[0076] (D1) In the above-described embodiment, the control unit 101 executes both the first operation and the second operation in the three-dimensional modeling process. On the other hand, the control unit 101 may execute only one of the first operation and the second operation.

[0077] (D2) In the above-mentioned embodiment, the control unit 101 performs the ejection operation of the plunger 77 together with the first operation in the acceleration section of the nozzle 61, and performs the suction operation of the plunger 77 together with the second operation in the deceleration section of the nozzle 61. In contrast, the control unit 101 may not perform either the ejection operation or the suction operation of the plunger 77. In addition, the control unit 101 may not perform both the ejection operation and the suction operation of the plunger 77. In the case where both the ejection operation and the suction operation are not performed, the three-dimensional modeling apparatus 100 may not include the plunger 77.

[0078] (D3) In the above-described embodiment, the control unit 101 performs both the process of sending an operation command for moving the plunger 77 to the suction and delivery unit 75 before the timing at which the rotation speed of the screw 40 reaches the second speed R2, and the process of sending an operation command for moving the plunger 77 to the suction and delivery unit 75 before the timing at which the rotation speed of the screw 40 reaches the fifth speed R5. In contrast, the control unit 101 may perform only one of these processes, or may not perform both processes.

[0079] (D4) In the above embodiment, the screw 40 is configured as a flat screw. However, the screw 40 may not be configured as a flat screw, but may be configured as an in-line screw.

[0080] E. Other methods:

[0081] The present disclosure is not limited to the above-mentioned embodiments, and can be implemented in various configurations within the scope of the main purpose. For example, in order to solve part or all of the above-mentioned problems, or to achieve part or all of the above-mentioned effects, the technical features of the embodiments corresponding to the technical features in each of the following modes can be appropriately replaced or combined. In addition, if the technical feature is not described as a necessary technical feature in this specification, it can be appropriately deleted.

[0082] (1) According to a first embodiment of the present disclosure, a three-dimensional modeling device is provided. The three-dimensional modeling device includes: a plasticizing unit having a screw and a motor for rotating the screw, plasticizing a material and generating a plasticized material; a nozzle having a nozzle opening and ejecting the plasticized material; and a control unit for controlling the plasticizing unit, wherein the control unit performs at least one of a first operation and a second operation, wherein the first operation is to adjust the ejection amount of the plasticized material from the nozzle from a first ejection amount to a second ejection amount larger than the first ejection amount, after adjusting the rotation speed of the screw from a first speed to a second speed larger than the first speed, to a third speed larger than the first speed and smaller than the second speed; and the second operation is to adjust the ejection amount of the plasticized material from the nozzle from a third ejection amount to a fourth ejection amount smaller than the third ejection amount, after adjusting the rotation speed of the screw from a fourth speed to a fifth speed smaller than the fourth speed, to a sixth speed larger than the fifth speed and smaller than the fourth speed. According to such an aspect, when the discharge amount is changed, the changed discharge amount can be quickly stabilized.

[0083] (2) In the above aspect, the control unit may adjust the rotation speed of the screw to the second speed in the first operation, and then adjust the rotation speed to a seventh speed which is lower than the second speed and higher than the third speed, and then adjust the rotation speed from the seventh speed to the third speed. According to such an aspect, it is possible to suppress the occurrence of an undershoot phenomenon in which the pressure of the plasticized material in the flow path is excessively reduced.

[0084] (3) In the above-mentioned aspect, the device may include: a flow path in which the plasticized material flows and is connected to the nozzle opening; and a suction and delivery unit having a branch flow path connected to the flow path and a plunger arranged in the branch flow path, the plasticized material in the flow path being sucked into the branch flow path and the plasticized material in the branch flow path being delivered to the flow path by changing the position of the plunger, wherein the control unit executes the control in an acceleration interval in which the relative movement speed of the nozzle is accelerated from a first movement speed to a second movement speed greater than the first movement speed. At least one of the first operation and the second operation in the deceleration interval in which the relative moving speed of the nozzle is decelerated from the second moving speed to the first moving speed, by moving the plunger in the branch flow path, thereby performing the operation of sending the plasticized material from the branch flow path to the flow path in the acceleration interval and the operation of sucking the plasticized material from the flow path to the branch flow path in the deceleration interval, so that the movement amount of the plunger in the acceleration interval matches the movement amount of the plunger in the deceleration interval. According to this method, since the position of the plunger can be controlled with high precision for a long time, the modeling accuracy of the three-dimensional modeling object can be improved.

[0085] (4) In the above-mentioned aspect, the control unit may perform at least one of the following: when the first operation is performed in the acceleration interval, before the rotation speed of the screw reaches the second speed, the operation command for moving the plunger is sent to the suction and delivery unit; and when the second operation is performed in the deceleration interval, before the rotation speed of the screw reaches the fifth speed, the operation command for moving the plunger is sent to the suction and delivery unit. According to such an aspect, it is possible to suppress the occurrence of insufficient or excessive discharge volume when the movement speed of the nozzle is accelerated or decelerated.

[0086] (5) In the above-mentioned aspect, the control unit may further accelerate the relative movement speed of the nozzle from the first movement speed to the second movement speed, and when the movement speed is decelerated from the third movement speed to the first movement speed, the control unit temporarily decelerates the movement speed from the third movement speed to the second movement speed, and then decelerates from the second movement speed to the first movement speed. According to such an aspect, even when the movement speed of the nozzle is changed in multiple stages, the position of the plunger can be controlled with high accuracy for a long period of time, thereby improving the molding accuracy of the three-dimensional object.

[0087] The present disclosure is not limited to the above-mentioned three-dimensional modeling apparatus, and can be implemented in various forms such as a method for manufacturing a three-dimensional object, a computer program, and a non-transitory tangible recording medium on which the computer program is recorded in a computer-readable manner.

Claims

1. A three-dimensional modeling device, characterized in that: have: A plasticizing part, comprising a screw and a motor for rotating the screw, plasticizing the material and generating a plasticized material; a nozzle having a nozzle opening for spraying the plasticized material; as well as A control unit controls the plasticizing unit, The control unit performs at least one of a first operation and a second operation, The first operation is an operation of adjusting the ejection amount of the plasticized material from the nozzle from a first ejection amount to a second ejection amount greater than the first ejection amount, and then adjusting the rotation speed of the screw from a first speed to a second speed greater than the first speed, and then adjusting the rotation speed to a third speed greater than the first speed and less than the second speed, The second operation is an operation in which, when the ejection amount of the plasticized material from the nozzle is adjusted from the third ejection amount to the fourth ejection amount that is smaller than the third ejection amount, after adjusting the rotation speed of the screw from the fourth speed to the fifth speed that is smaller than the fourth speed, the rotation speed is adjusted to the sixth speed that is larger than the fifth speed and smaller than the fourth speed.

2. The three-dimensional modeling device according to claim 1, wherein: In the first operation, the control unit adjusts the rotation speed of the screw to the second speed, then adjusts the rotation speed to a seventh speed which is lower than the second speed and higher than the third speed, and then adjusts the rotation speed from the seventh speed to the third speed.

3. The three-dimensional modeling device according to claim 1, wherein: The three-dimensional modeling device comprises: a flow path in which the plasticized material flows, the flow path being in communication with the nozzle opening; and The suction and delivery section has a branch flow path connected to the flow path and a plunger arranged in the branch flow path, and is configured to suck the plasticized material in the flow path into the branch flow path and deliver the plasticized material in the branch flow path to the flow path by changing the position of the plunger. The control unit performs performing the first operation in an acceleration interval in which the relative movement speed of the nozzle is accelerated from a first movement speed to a second movement speed greater than the first movement speed; as well as An operation of performing the second operation in a deceleration section in which the relative movement speed of the nozzle is decelerated from the second movement speed to the first movement speed. At least one of the operations in The plunger is moved in the branch flow path, thereby performing an operation of delivering the plasticized material from the branch flow path to the flow path in the acceleration section and an operation of sucking the plasticized material from the flow path to the branch flow path in the deceleration section. The movement amount of the plunger in the acceleration section is matched with the movement amount of the plunger in the deceleration section.

4. The three-dimensional modeling device according to claim 3, wherein: The control unit performs processing of sending an operation command for moving the plunger to the suction and delivery section before the rotation speed of the screw reaches the second speed when the first operation is performed in the acceleration section; as well as When the second operation is performed in the deceleration zone, an operation command for moving the plunger is sent to the processing unit of the suction delivery unit before the rotation speed of the screw reaches the fifth speed. At least one of the parties.

5. The three-dimensional modeling device according to claim 3, wherein: The control unit After the relative movement speed of the nozzle is accelerated from the first movement speed to the second movement speed, the relative movement speed is further accelerated to a third movement speed greater than the second movement speed. When the moving speed is decelerated from the third moving speed to the first moving speed, the moving speed is temporarily decelerated from the third moving speed to the second moving speed, and then decelerated from the second moving speed to the first moving speed.

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