Three-dimensional printing apparatus and method for manufacturing three-dimensional objects

Abstract

To suppress inability to perform a desired plunger operation due to lack of a space for moving a plunger in a three-dimensional molding device.SOLUTION: A three-dimensional molding device includes: a position change part that changes a relative position of a nozzle that discharges a molding material toward a stage from a nozzle opening and a stage; a discharge amount adjustment part that adjusts a discharge amount by changing an opening area of a flow path; a pressure adjustment part that has a branch flow path connected to the flow path between the discharge amount adjustment part and the nozzle opening, and a plunger that moves within the branch flow path; and a control part that controls the position change part, the discharge amount adjustment part, and the pressure adjustment part. When molding one continuous line-shaped partial molded object, the control part performs operations of sucking the molding material into the branch flow path and delivering the sucked molding material into the flow path by moving the plunger, and controls the movement of the plunger so that a position of the plunger coincides with a start end and a finish end of a molding section of the partial molded object.SELECTED DRAWING: Figure 1

Description

[[Technical Field]]

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

[0002] Regarding a three-dimensional modeling apparatus, Patent Document 1 discloses an apparatus including a suction mechanism having a butterfly valve provided in a flow path, a cylinder connected to the flow path, and a plunger disposed inside the cylinder. In the apparatus of Patent Document 1, pulling the plunger away from the flow path sucks the material in the flow path into the cylinder, and pushing the plunger toward the flow path pushes the material in the cylinder out into the flow path. [[Prior Art Documents]] [[Patent Documents]]

[0003] [[Patent Document 1]] Japanese Unexamined Patent Publication No. 2021-62566 [[Summary of the Invention]] [[Problem to be Solved by the Invention]]

[0004] In an apparatus including a plunger as in Patent Document 1, the position of the plunger in the branched flow path of the plunger changes due to operation of the plunger, so there have been cases where a desired plunger operation cannot be performed immediately due to insufficient space for moving the plunger. For example, when further pulling the plunger after continuously pulling the plunger, it was necessary to temporarily suspend modeling, push the plunger to discharge the material to the outside, and secure space for further pulling the plunger within the cylinder. [[Means for Solving the Problem]]

[0005] A three-dimensional molding apparatus is provided according to a first embodiment of the present disclosure. The three-dimensional molding apparatus comprises a nozzle having a nozzle opening and discharging molding material from the nozzle opening toward a stage; a position changing unit that changes the relative position between the nozzle and the stage; a discharge volume adjustment unit that communicates with the nozzle opening and is provided in a flow path through which the molding material flows, and adjusts the amount of molding material discharged from the nozzle opening by changing the opening area of ​​the flow path; a pressure adjustment unit having a branch flow path connected to the flow path between the discharge volume adjustment unit and the nozzle opening, and a plunger that moves within the branch flow path; and a control unit that controls the position changing unit, the discharge volume adjustment unit and the pressure adjustment unit. When creating a continuous linear partial object, the control unit moves the plunger to perform the operations of drawing the material in the flow channel into the branched flow channel and sending the material drawn into the branched flow channel back into the flow channel, and controls the movement of the plunger so that the position of the plunger in the branched flow channel coincides with the start end and end end of the printing section for creating the partial object.

[0006] A second embodiment of the present disclosure provides a method for manufacturing a three-dimensional object in a three-dimensional molding apparatus, comprising: a nozzle having a nozzle opening and discharging a molding material from the nozzle opening toward a stage; a position changing unit for changing the relative position between the nozzle and the stage; a discharge volume adjusting unit communicating with the nozzle opening and provided in a flow path through which the molding material flows, and adjusting the amount of molding material discharged from the nozzle opening by changing the opening area of ​​the flow path; a branched flow path connected to the flow path between the discharge volume adjusting unit and the nozzle opening; and a pressure adjusting unit having a plunger that moves within the branched flow path. When manufacturing a continuous linear partial object, this manufacturing method comprises the steps of: moving the plunger to draw the molding material in the flow path into the branched flow path; and sending the molding material drawn into the branched flow path back into the flow path, wherein the plunger is moved so that its position within the branched flow path coincides with the start end and end end of the manufacturing section for manufacturing the partial object. [Brief explanation of the drawing]

[0007] [Figure 1] An explanatory diagram showing the schematic configuration of the three-dimensional molding apparatus in the first embodiment. [Figure 2] A perspective view showing the schematic configuration of the screw. [Figure 3] A schematic plan view showing the barrel. [Figure 4] A schematic diagram illustrating the process by which a three-dimensional object is created. [Figure 5] Flowchart for 3D modeling processing. [Figure 6] An explanatory diagram showing an example of a partially molded object. [Figure 7] A diagram illustrating the changes in scanning speed, channel opening, and plunger position. [Figure 8] A diagram illustrating the change in the opening degree of the flow path in the second embodiment. [Modes for carrying out the invention]

[0008] A. First Embodiment: Figure 1 is an explanatory diagram showing the schematic configuration of the three-dimensional molding apparatus 100 in the first embodiment. Figure 1 shows arrows along the mutually orthogonal X, Y, and Z directions. The X, Y, and Z directions are directions along the three mutually orthogonal spatial axes, the X-axis, Y-axis, and Z-axis, and each includes both the direction along one side of the X-axis, Y-axis, and Z-axis, and the opposite direction. The X-axis and Y-axis are axes along the horizontal plane, and the Z-axis is an axis along the vertical line. Arrows along the X, Y, and Z directions are also shown in other figures as appropriate. The X, Y, and Z directions in Figure 1 and the X, Y, and Z directions in the other figures represent the same directions. Hereafter, the +Z direction will also be referred to as "up" and the -Z direction as "down".

[0009] The three-dimensional molding apparatus 100 includes a control unit 101 that controls the three-dimensional molding apparatus 100, an ejection unit 200 that generates and ejects molding material, a molding stage 210 that serves as the base for the three-dimensional molded object, and a position changing unit 230 that controls the ejection position of the molding material.

[0010] The discharge unit 200, under the control of the control unit 101, melts a solid material into a paste and discharges the resulting molding material onto the stage 210. The discharge unit 200 includes a material supply unit 20, which is a source of material before it is converted into molding material; a plasticizing unit 30, which plasticizes at least a portion of the material to generate molding material; a flow path 69 through which the generated molding material flows; a nozzle 61 that communicates with the flow path 69 and discharges the molding material; a discharge volume adjustment unit 70 provided in the flow path 69; and a pressure adjustment unit 75 provided in the flow path 69. The flow path 69 communicates with the nozzle opening 62 of the nozzle 61, which will be described later.

[0011] The material supply unit 20 contains materials in the form of pellets or powder. In this embodiment, resin formed into pellets is used as the material. The material supply unit 20 in this embodiment is composed of a hopper. Below the material supply unit 20, a supply passage 22 is provided that connects the material supply unit 20 and the plasticizing unit 30. The material supply unit 20 supplies material to the plasticizing unit 30 via the supply passage 22.

[0012] The plasticizing unit 30 comprises a screw case 31, a drive motor 32, a screw 40, and a barrel 50. The plasticizing unit 30 plasticizes at least a portion of the material supplied from the material supply unit 20 to produce a fluid, paste-like molding material. The plasticizing unit 30 then supplies the produced molding material to the nozzle 61. "Plasticization" is a concept that includes melting and refers to changing a solid state to a fluid state. Specifically, in the case of materials that undergo a glass transition, plasticization means raising the temperature of the material above the glass transition point. In the case of materials that do not undergo a glass transition, plasticization means raising the temperature of the material above the melting point. The screw 40 in this embodiment is sometimes called a flat screw or a scroll screw.

[0013] Figure 2 is a perspective view showing the schematic configuration of the screw 40. Figure 3 is a schematic plan view showing the barrel 50. The screw 40 has a substantially cylindrical shape in which the length in the axial direction, which is along its central axis RX, is smaller than the length in the direction perpendicular to the axial direction. The screw 40 is positioned so that its central axis RX, which is the center of rotation, is parallel to the Z direction.

[0014] As shown in Figure 1, the screw 40 is housed in the screw case 31. The upper surface 41 side of the screw 40 is connected to the drive motor 32, and the screw 40 rotates within the screw case 31 by the rotational driving force generated by the drive motor 32. The drive motor 32 is driven under the control of the control unit 101. The screw 40 may also be driven by the drive motor 32 via a reduction gear.

[0015] As shown in Figure 2, a spiral groove 45 is formed on the lower surface 42 of the screw. The supply passage 22 of the material supply unit 20, as described above, communicates with the groove 45 from the side surface 43 of the screw 40. The groove 45 continues to a material inlet 44 formed on the side surface 43 of the screw 40. This material inlet 44 is the part that receives the material supplied via the supply passage 22 of the material supply unit 20. As shown in Figure 2, in this embodiment, three grooves 45 are formed, separated by protrusions 46. Note that the number of grooves 45 is not limited to three; there may be one or two or more. The grooves 45 are not limited to a spiral shape; they may be helical or involute curves, or they may extend in an arc from the central part 47 toward the outer circumference.

[0016] As shown in Figure 1, the barrel 50 is disposed below the screw 40. The upper barrel surface 52 faces the lower screw surface 42, and a space is formed between the groove 45 of the lower screw surface 42 and the upper barrel surface 52. The barrel 50 is provided with a communication hole 56 on the central axis RX of the screw 40, the communication hole 56 communicating with a nozzle 61 to be described later. In the present embodiment, the communication hole 56 forms a part of the flow path 69 described above. A heater 58 is built in the barrel 50 at a position facing the groove 45 of the screw 40. The temperature of the heater 58 is controlled by the control unit 101.

[0017] The material supplied into the groove 45 of the screw 40 flows along the groove 45 by the rotation of the screw 40 while being melted in the groove 45, and is guided as a modeling material to the central portion 47 of the screw 40. The paste-like modeling material that exhibits fluidity and has flowed into the central portion 47 is supplied to the nozzle 61 through the communication hole 56. Note that, in the modeling material, not all types of substances constituting the modeling material need to be melted. It is sufficient that the modeling material is converted into a state having fluidity as a whole by melting at least part of the types of substances constituting the modeling material.

[0018] As shown in Figure 1, the nozzle 61 includes a nozzle flow path 65 and a distal end surface 63 provided with a nozzle opening 62. The nozzle flow path 65 is a flow path for the modeling material formed inside the nozzle 61, and forms a part of the flow path 69 described above. The distal end surface 63 is a surface constituting a distal end portion of the nozzle 61 that protrudes in the -Z direction toward the modeling surface 211. The nozzle opening 62 is a portion with a reduced flow path cross-section of the nozzle flow path 65, which is provided at an end of the nozzle flow path 65 on the side communicating with the atmosphere, that is, at an end on the distal end surface 63 side. The modeling material generated by the plasticizing unit 30 is discharged from the nozzle opening 62 through the flow path 69. A heater that suppresses a temperature drop of the modeling material discharged onto the stage 210 may be disposed around the nozzle 61.

[0019] The discharge amount adjustment unit 70 adjusts the discharge amount by changing the opening area of the flow path 69. The discharge amount adjustment unit 70 in the present embodiment is configured by a butterfly valve and is provided in the nozzle flow path 65. The discharge amount adjustment unit 70 changes the opening degree of the nozzle flow path 65 by rotating within the nozzle flow path 65. The discharge amount adjustment unit 70 is driven by the first drive unit 74 under the control of the control unit 101. The first drive unit 74 is configured by, for example, a stepping motor. The control unit 101 adjusts the amount of modeling material flowing through the flow path 69 by controlling the rotation angle of the butterfly valve using the first drive unit 74. Accordingly, the flow rate of the modeling material flowing from the plasticizing unit 30 to the nozzle 61 can be adjusted, and the discharge amount can be adjusted. The discharge amount adjustment unit 70 adjusts the flow rate of the modeling material and controls on / off of the outflow of the modeling material.

[0020] The pressure adjustment unit 75 includes a branch flow path 76, a plunger 77, and a second drive unit 78. The branch flow path 76 is connected to the flow path 69 between the discharge amount adjustment unit 70 and the nozzle opening 62, that is, to a portion of the flow path 69 between the discharge amount adjustment unit 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 in the -X direction from the connection portion with the nozzle flow path 65. The plunger 77 moves within the branch flow path 76. More specifically, the plunger 77 is driven by the second drive unit 78 under the control of the control unit 101. The second drive unit 78 is configured by, for example, a stepping motor, or a rack-and-pinion mechanism that converts the rotational force of the stepping motor into translational motion of the plunger 77.

[0021] When creating a partial object, as described later, the control unit 101 controls the pressure adjustment unit 75 to move the plunger 77 within the branched channel 76, thereby performing suction and discharge operations. Suction operation refers to the operation of drawing the material in the channel 69 into the branched channel 76. Discharge operation refers to the operation of discharging the material drawn into the branched channel 76 back into the channel 69. In this embodiment, during the suction operation, the control unit 101 retracts the plunger 77 away from the nozzle channel 65, and during the discharge operation, it advances the plunger 77 towards the nozzle channel 65.

[0022] When a suction operation is performed, the molding material in the nozzle channel 65 is sucked into the pressure adjustment unit 75, so the pressure in the nozzle channel 65 decreases. When a discharge operation is performed, the molding material is discharged from the pressure adjustment unit 75 into the nozzle channel 65, so the pressure in the nozzle channel 65 increases. In this way, the pressure adjustment unit 75 adjusts the pressure in the channel 69.

[0023] Furthermore, by performing a suction operation to reduce the pressure in the flow path 69, it is possible to suppress the trailing phenomenon in which the molding material sags in a string-like manner from the nozzle opening 62. In this case, the control unit 101 can more effectively suppress the trailing phenomenon by performing the suction operation after setting the opening of the nozzle flow path 65 to zero using the discharge volume adjustment unit 70. It is also possible to improve the responsiveness of the molding material discharge from the nozzle opening 62 by performing a discharge operation to increase the pressure in the flow path 69. In this case, the control unit 101 can further improve the responsiveness of the molding material discharge by performing the discharge operation before setting the opening of the nozzle flow path 65 to more than zero using the discharge volume adjustment unit 70.

[0024] The stage 210 is positioned opposite the nozzle 61. The three-dimensional molding apparatus 100 creates a three-dimensional object by extruding molding material from the nozzle opening 62 toward the molding surface 211 of the stage 210 and stacking layers. The area where the three-dimensional object is formed, including the molding surface 211 and the area above the molding surface 211, is also called the molding area.

[0025] The position changing unit 230 changes the relative position between the nozzle 61 and the stage 210. In this embodiment, the position changing unit 230 moves the stage 210 relative to the nozzle 61. The change in the relative position of the nozzle 61 relative to the stage 210 is sometimes simply referred to as the movement or scanning of the nozzle 61. In this embodiment, for example, moving the stage 210 in the +X direction can be rephrased as moving the nozzle 61 in the -X direction. The relative movement speed of the nozzle 61 relative to the stage 210 is also called the relative movement speed of the nozzle 61. The relative movement speed of the nozzle 61 is also simply referred to as the movement speed or scanning speed of the nozzle 61. In this embodiment, the position changing unit 230 is composed of a three-axis positioner that moves the stage 210 in the three axes of X, Y, and Z using the driving force of three motors. Each motor is driven under the control of the control unit 101. Furthermore, the position changing unit 230 may not be configured to move the stage 210, but rather to move the nozzle 61 without moving the stage 210. Alternatively, the position changing unit 230 may be configured to move both the stage 210 and the nozzle 61.

[0026] The control unit 101 is composed of a computer comprising one or more processors, main memory, and an input / output interface for inputting and outputting signals to and from the outside. In this embodiment, the control unit 101 performs various functions, such as executing three-dimensional molding processes for fabricating three-dimensional objects, by having the processor execute programs and instructions loaded into the main memory. Note that the control unit 101 may be composed of a combination of multiple circuits instead of a computer.

[0027] The control unit 101 controls the ejection unit 200 and the position change unit 230 according to the molding data during the three-dimensional molding process to mold an object in the molding area on the molding surface 211. The molding data includes molding path data representing the movement path of the nozzle 61 relative to the stage 210, and ejection amount data representing the ejection amount associated with the molding path data. The ejection amount refers to the amount of molding material ejected from the nozzle opening 62.

[0028] Figure 4 is a schematic diagram illustrating how a three-dimensional object is fabricated in the three-dimensional molding apparatus 100. In the three-dimensional molding apparatus 100, as described above, in the plasticizing section 30, the solid material supplied to the groove 45 of the rotating screw 40 is melted to generate the molding material MM. The control unit 101 maintains the distance between the molding surface 211 of the stage 210 and the nozzle 61, and while changing the position of the nozzle 61 relative to the stage 210 in a direction along the molding surface 211 of the stage 210, it ejects the molding material MM from the nozzle 61. The molding material MM ejected from the nozzle 61 is continuously deposited in the direction of movement of the nozzle 61. Through this scanning by the nozzle 61, a linearly extending molding portion is fabricated along the scanning path of the nozzle 61. In this way, a continuous linear molding portion of a three-dimensional object is also called a partial molding portion Op.

[0029] The control unit 101 forms layers ML by repeatedly scanning with the nozzle 61 as described above. 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, it builds a three-dimensional object by stacking more layers ML on top of the layers ML that have been formed so far. When stacking layers of the build material, the control unit 101 extrudes the build material from the nozzle 61 while maintaining the distance between the nozzle 61 and the extrusion target. The extrusion target is the build surface 211 when extruding the build material onto the build surface 211, and the upper surface of the already extruded build material when extruding the build material onto already extruded build material. The distance between the nozzle 61 and the extrusion target is sometimes called the gap Gp.

[0030] The width of the partial object Op described above is also called the line width, and the height of the partial object Op is also called the layer pitch. The line width and layer pitch are determined by the size of the gap Gp described above and the amount of material extruded from the nozzle 61 per unit movement. For example, when the gap Gp is ​​small, the material extruded from the nozzle 61 is pressed more firmly against the extrusion target by the nozzle 61 compared to when the gap Gp is ​​large, resulting in a smaller layer pitch and a larger line width. The amount of material extruded from the nozzle 61 per unit movement is determined by the movement speed of the nozzle 61 and the amount of material extruded from the nozzle 61 per unit time. The amount of material extruded from the nozzle 61 per unit time is determined, for example, by the size of the nozzle opening 62, the flow rate of the material flowing through the flow path 69, the pressure in the flow path 69, etc.

[0031] Figure 5 is a flowchart of the three-dimensional molding process that realizes the manufacturing method of a three-dimensional object in this embodiment. First, in step S110, the control unit 101 acquires shape data representing the shape of the three-dimensional object from an external computer or recording medium. The control unit 101 acquires shape data such as three-dimensional CAD data from an external source, for example, via a network or recording medium.

[0032] Next, in step S120, the control unit 101 generates molding data for fabricating the three-dimensional object represented in the three-dimensional data acquired in step S110. More specifically, in step S120, the control unit 101 generates the molding path data and extrusion amount data described above. In other embodiments, instead of the control unit 101 generating the molding data by performing steps S110 and S120, the molding data may be acquired from an external source, for example, via a network or recording medium.

[0033] In step S130, the control unit 101 determines the movement speed data and the ejection control parameters. The movement speed data represents the movement speed of the nozzle 61 in each movement path included in the build path data. The ejection control parameters represent the parameters for controlling the ejection volume adjustment unit 70 and the pressure adjustment unit 75 in each movement path. Details of the ejection control parameters will be described later. The movement speed data and ejection control parameters determined in step S130 may be included in the build data or may be generated as separate data from the build data.

[0034] Next, in step S140, the control unit 101 controls the ejection unit 200 and the position change unit 230 based on the molding data generated in step S120, and the movement speed data and ejection control parameters generated in step S130, to fabricate one layer of the three-dimensional object. More specifically, in step S140, the control unit 101 fabricates one or more partial objects constituting one layer of the three-dimensional object in the fabrication area on the fabrication surface 211. In step S150, the control unit 101 determines whether the fabrication of all layers of the three-dimensional object is complete. If the control unit 101 determines that the fabrication of all layers of the three-dimensional object is not complete, it returns to step S140 and executes the fabrication of the next layer. If the control unit 101 determines that the fabrication of all layers is complete, it terminates the three-dimensional fabrication process.

[0035] Figure 6 is an explanatory diagram showing an example of a partial object in this embodiment. Figure 6 schematically shows a first partial object Op1 and a second partial object Op2 as examples of partial objects that form a layer of a three-dimensional object. Figure 6 also shows two printing sections for printing the partial objects: a first printing section Ms1 for printing the first partial object Op1 and a second printing section Ms2 for printing the second partial object Op2. The first printing section Ms1 is represented by the movement path included in the printing path data for printing the first partial object Op1. The second printing section Ms2 is represented by the movement path included in the printing path data for printing the second partial object Op2. In Figure 6, the movement paths of the nozzle 61 are shown by solid lines when the nozzle 61 moves while extruding the molding material, and by dashed lines when the nozzle 61 moves without extruding the molding material.

[0036] Figure 7 illustrates the changes in scanning speed of the nozzle 61, the opening of the flow path 69, and the position of the plunger 77 when fabricating a partial object. Figure 7 shows the changes in scanning speed, the opening of the flow path 69, and the position of the plunger 77 with respect to time when fabricating the first partial object Op1 and the second partial object Op2 shown in Figure 6. More specifically, the upper part of Figure 7 shows a schematic graph with time on the horizontal axis and scanning speed on the vertical axis. Note that in the upper part of Figure 7, the transition of scanning speed in the intervals between each fabrication section, that is, the intervals in which the nozzle 61 moves without extruding fabrication material, is omitted. The middle part of Figure 7 similarly shows a graph with time on the horizontal axis and the opening of the flow path 69 on the vertical axis. The lower part of Figure 7 similarly shows a graph with time on the horizontal axis and the plunger position on the vertical axis. The plunger position in the lower part of Figure 7 represents the position coordinates in the X direction of the end face 79 on the +X direction side of the plunger 77 shown in Figure 1. In this embodiment, when the plunger position is zero, the end face 79 is located at the midpoint of its movable range. That is, when the end face 79 is located closer to the flow path 69 than the midpoint, the plunger position shown in Figure 7 takes a positive value. When the end face 79 is located on the opposite side of the flow path 69 than the midpoint, the plunger position shown in Figure 7 takes a negative value. Therefore, the larger the value of the plunger position shown in Figure 7, the closer the plunger 77 is located to the flow path 69.

[0037] The nozzle opening 62 is located at points P1 to P6 shown in Figure 6 at each of the times t1 to t6 shown in Figure 7. Points P1 and P4 correspond to the start end St1 and end end Ed1 of the first molding section Ms1, respectively. Points P5 and P6 correspond to the start end St2 and end end Ed2 of the second molding section Ms2, respectively.

[0038] In this embodiment, the first molding section Ms1 shown in Figures 6 and 7 has three designated sections. A designated section refers to a section within the molding section in which the relative movement of the nozzle 61 with respect to the stage 210 at a constant moving speed is instructed. More specifically, the first molding section Ms1 has three designated sections: the first designated section Sc1, the second designated section Sc2, and the third designated section Sc3. The first to third designated sections Sc1 to Sc3 correspond to the sections from time t1 to time t2, from time t2 to time t3, and from time t3 to time ts4, respectively. In the first designated section Sc1 and the third designated section Sc3, scanning of the nozzle 61 at a first scanning speed v1 is instructed. In the second designated section Sc2, scanning of the nozzle 61 at a second scanning speed v2 is instructed. The first scanning speed v1 and the second scanning speed v2 represent the magnitude of the relative movement speed of the nozzle 61 with respect to the stage 210. The second scanning speed v2 is slower than the first scanning speed v1.

[0039] In this embodiment, the first build section Ms1 has two acceleration sections and two deceleration sections. An acceleration section is a section within the build section in which the scanning speed of the nozzle 61 is accelerated. A deceleration section is a section within the build section in which the scanning speed of the nozzle 61 is decelerated. More specifically, the first build section Ms1 has two acceleration sections: a first acceleration section As1 and a second acceleration section As2. In the first acceleration section As1, the scanning speed of the nozzle 61 is accelerated from zero to a first scanning speed v1. In this embodiment, the first acceleration section As1 is included in the first designated section Sc1. The starting end of the first acceleration section As1 corresponds to the starting end of the first designated section Sc1 and the starting end St1 of the first build section Ms1. In the second acceleration section As2, the scanning speed is accelerated from a second scanning speed v2 to a first scanning speed v1. The second acceleration section As2 is included in the third designated section Sc3.

[0040] The first molding section Ms1 includes a first deceleration section Ds1 and a second deceleration section Ds2 as deceleration sections. In the first deceleration section Ds1, the scanning speed of the nozzle 61 is reduced from a first scanning speed v1 to a second scanning speed v2. In this embodiment, the first deceleration section Ds1 is included in the second designated section Sc2. In the second deceleration section Ds2, the scanning speed of the nozzle 61 is reduced from a first scanning speed v1 to zero. In this embodiment, the second deceleration section Ds2 is included in the third designated section Sc3. The end of the second deceleration section Ds2 corresponds to the end of the third designated section Sc3 and the end of the first molding section Ms1, Ed1.

[0041] Similarly, the second build section Ms2 has a fourth designated section Sc4 as a designated section. The fourth designated section Sc4 corresponds to the section from time t5 to time t6. In the fourth designated section Sc4, scanning of the nozzle 61 at the second scanning speed v2 is instructed. The second build section Ms2 also has a third acceleration section As3 as an acceleration section and a third deceleration section Ds3 as a deceleration section. The third acceleration section As3 and the third deceleration section Ds3 are included in the fourth designated section Sc4. In the third acceleration section As3, the scanning speed of the nozzle 61 is accelerated from zero to the second scanning speed v2. In this embodiment, the start end of the third acceleration section As3 corresponds to the start end of the fourth designated section Sc4 and the start end of the second build section Ms2. In the third deceleration section Ds3, the scanning speed is reduced from the second scanning speed v2 to zero. The end of the third deceleration section Ds3 corresponds to the end of the third designated section Sc3 and the end of the second molding section Ms2, Ed2.

[0042] In this embodiment, the control unit 101 performs at least one of the first operation, the second operation, and the third operation in a designated section. The first operation refers to the operation of discharging the molding material from the nozzle opening 62 without controlling the pressure adjustment unit 75 and with the flow path 69 opened by the discharge volume adjustment unit 70. The second operation refers to the operation of discharging the molding material from the nozzle opening 62 by controlling the pressure adjustment unit 75 and performing a discharge operation with the flow path 69 opened by the discharge volume adjustment unit 70. The third operation refers to the operation of discharging the molding material from the nozzle opening 62 by controlling the pressure adjustment unit 75 and performing a discharge operation with the flow path 69 closed by the discharge volume adjustment unit 70.

[0043] As shown in Figure 7, in this embodiment, the control unit 101 executes the second operation described above in accordance with the acceleration section and the fourth operation in accordance with the deceleration section. The fourth operation refers to the operation of performing a suction operation with the flow path 69 opened by the discharge volume adjustment unit 70. The control unit 101 also executes the first operation in each designated section, excluding the sections in which the second and fourth operations are performed. Therefore, in this embodiment, in the first designated section Sc1, the first operation is performed after the second operation is performed in the first acceleration section As1. In the second designated section Sc2, the first operation is performed after the fourth operation is performed in the first deceleration section Ds1. In the third designated section Sc3, the first operation is performed after the second operation is performed in the second acceleration section As2, and then the fourth operation is performed in the second deceleration section Ds2. In the fourth designated section Sc4, the first operation is performed after the second operation is performed in the third acceleration section As3, and then the fourth operation is performed in the third deceleration section Ds3. Thus, in this embodiment, the second operation is performed before the first operation.

[0044] In this embodiment, as shown in Figure 7, the control unit 101, in the first operation, keeps the flow path 69 open and maintains a constant opening, and extrudes the molding material from the nozzle opening 62 without changing the position of the plunger 77. In the second operation, that is, in the acceleration section, the control unit 101 controls the discharge volume adjustment unit 70 to gradually increase the opening of the flow path 69, and controls the pressure adjustment unit 75 to advance the plunger 77 so that it gradually approaches the flow path 69. In this embodiment, by controlling the discharge volume adjustment unit 70, the control unit 101 makes the opening area in the second operation smaller than the opening area in the first operation. The opening area in the first and second operations refers to the time average value of the opening area from the start to the end of the operation. Furthermore, in the fourth operation, that is, in the deceleration section, the control unit 101 controls the discharge volume adjustment unit 70 to gradually decrease the opening of the flow path 69, and controls the pressure adjustment unit 75 to retract the plunger 77 so that it gradually moves away from the flow path 69.

[0045] In step S130, the control unit 101 controls the movement of the plunger 77 so that its position within the branch channel 76 coincides at the start and end ends of the molding section. In this embodiment, the control unit 101 achieves this control of the plunger 77's position at the start and end ends by controlling the sum of the displacements of the plunger 77 due to the movement of the plunger 77 corresponding to each acceleration section in a given molding section and the sum of the displacements of the plunger 77 due to the movement of the plunger 77 corresponding to each deceleration section. More specifically, the control unit 101 controls the movement of the plunger 77 so that the sum of the displacements of the plunger 77 due to the movement of the plunger 77 corresponding to each acceleration section in a given molding section cancels out the sum of the displacements of the plunger 77 due to the movement of the plunger 77 corresponding to each deceleration section. The displacement of the plunger 77 is expressed as a vector quantity, taking a positive value when the plunger 77 moves closer to the flow path 69, and a negative value when the plunger 77 moves away from the flow path 69. In this embodiment, the control unit 101 executes only the discharge operation among the discharge operation and the suction operation in relation to each acceleration section, and executes only the suction operation among the discharge operation and the suction operation in relation to each deceleration section. Therefore, in this embodiment, canceling out the sum of the displacements of the plunger 77 in relation to each acceleration section with the sum of the displacements of the plunger 77 in relation to each deceleration section is equivalent to making the sum of the amount of movement of the plunger 77 in relation to each acceleration section equal.

[0046] Furthermore, when the control unit 101 controls the movement of the plunger 77 so that the position of the plunger 77 coincides at the start and end ends of the molding section, it is not necessary to perfectly coincide the position of the plunger 77 at the start and end ends of the molding section. More specifically, if the difference in the position of the plunger 77 at the start and end ends of a certain molding section is 20% or less of the movable distance of the plunger 77 within the branch channel 76, it can be interpreted that the position of the plunger 77 coincides at the start and end ends of that molding section. More preferably, the difference in the position of the plunger 77 at the start and end ends of the molding section is 10% or less, and even more preferably 5% or less.

[0047] In this embodiment, in step S130, the control unit 101 controls the movement of the plunger 77 so that the amount of movement of the plunger 77 in the first section matches the amount of movement of the plunger 77 in the second section. The first section refers to the section in which the scanning speed is accelerated from a first speed to a second speed that is faster than the first speed. The control unit 101 performs either a suction operation or a discharge operation in the first section. The second section refers to the section in which the scanning speed is decelerated from the second speed to the first speed. The control unit 101 performs either a suction operation or a discharge operation in the second section, whichever is different from the operation performed in the first section. In other words, if the suction operation is performed in the first section, the control unit 101 performs a discharge operation in the second section, and if the discharge operation is performed in the first section, the control unit 101 performs a suction operation in the second section.

[0048] For example, in the example in Figure 7, if the first acceleration section As1 is considered the first section, then the second deceleration section Ds2 corresponds to the second section. In this case, a scanning speed of zero corresponds to the first speed, and the first scanning speed v1 corresponds to the second speed. The control unit 101 controls the movement of the plunger 77 such that the amount of movement of the plunger 77 in the +X direction during the discharge operation performed in the first acceleration section As1, which is the first section, matches the amount of movement of the plunger 77 in the -X direction during the suction operation performed in the second deceleration section Ds2, which is the second section. As a result, the position of the plunger 77 coincides at the start end of the first acceleration section As1 and at the end end of the second deceleration section Ds2. Also, for example, if the second acceleration section As2 is considered the first section, then the first deceleration section Ds1 corresponds to the second section. In this case, the second scanning speed v2 corresponds to the first speed, and the first scanning speed v1 corresponds to the second speed. Then, the movement of the plunger 77 is controlled so that the amount of movement of the plunger 77 in the +X direction during the transmission operation performed in the first section, the second acceleration section As2, matches the amount of movement of the plunger 77 in the -X direction during the second section, the first deceleration section Ds1. As a result, the position of the plunger 77 coincides at the start end of the first deceleration section Ds1 and the end end of the second acceleration section As2. In this way, the control unit 101 can be said to change the scanning speed in opposite directions for the first and second sections, and move the plunger 77 by the same amount in opposite directions corresponding to the first and second sections, respectively. Similarly, if the third acceleration section As3 is the first section, then the third deceleration section Ds3 corresponds to the second section.

[0049] In this embodiment, "movement of the plunger 77 corresponding to a certain section" corresponds to the movement of the plunger 77 within that section. In other embodiments, "movement of the plunger 77 corresponding to a certain section" may include the movement of the plunger 77 outside that section. For example, the movement of the plunger 77 corresponding to the first section may be a movement that starts before the first section and is completed in the middle of the first section or after the first section, or a movement that starts in the middle of the first section and is completed after the first section.

[0050] In this embodiment, the control unit 101 controls the discharge volume adjustment unit 70 and the pressure adjustment unit 75 by determining the above-described discharge control parameters so that a substantially constant line width is achieved in each molding section. The control unit 101 determines the opening degree of the flow path 69 by the discharge volume adjustment unit 70, the speed and timing of the adjustment of the opening degree, and the amount, timing and speed of movement of the plunger 77 as discharge control parameters. For example, the control unit 101 can increase the discharge volume and thus the line width by increasing the opening degree of the flow path 69 by the discharge volume adjustment unit 70. In addition, in the acceleration section, the control unit 101 can increase the discharge volume and thus the line width by starting to increase the opening degree of the flow path 69 earlier and increasing the speed of the adjustment, that is, by increasing the amount of change in the opening degree per unit time. In the deceleration section, the control unit 101 can increase the discharge volume and line width by delaying the timing at which it begins to reduce the opening of the flow path 69, and by reducing the adjustment speed, that is, by reducing the amount of change in the opening per unit time. Furthermore, in the discharge operation and suction operation, the control unit 101 can adjust the discharge volume and line width by controlling the amount of movement of the plunger 77, the control timing of the plunger 77, and the movement speed of the plunger 77. In the acceleration and deceleration sections, the amount of adjustment of the opening of the flow path 69 by the discharge volume adjustment unit 70, the adjustment speed, the adjustment timing, and the amount of movement of the plunger 77, the movement timing, and the movement speed may be determined according to, for example, the type of molding material, the line width, the set temperature of the heater 58, the rotation speed of the screw 40, etc.

[0051] In this embodiment, when the control unit 101 determines the discharge control parameters in step S130 described above, it sets a second section and then sets a first section corresponding to that second section. For example, when the control unit 101 determines the discharge control parameters in the first molding section Ms1, it first sets the second deceleration section Ds2 shown in Figures 6 and 7. When the control unit 101 sets the second deceleration section Ds2, it determines the timing of the opening adjustment by the discharge amount adjustment unit 70 and the amount of movement of the plunger 77 in the suction operation performed in the second deceleration section Ds2, so that a constant line width is achieved in the second deceleration section Ds2 and trailing is suppressed at the end end Ed1 of the first molding section Ms1. When setting the first acceleration section As1, the control unit 101 determines the amount of movement of the plunger 77 in the discharge operation performed in the first acceleration section As1 so as to match the amount of movement of the plunger 77 in the second deceleration section Ds2. Furthermore, the control unit 101 determines the timing and speed of the opening adjustment by the discharge volume adjustment unit 70 so that a constant line width is achieved in the first acceleration section As1, according to the determined amount of movement of the plunger 77. For example, in the middle section of Figure 7, the adjustment speed of the opening is adjusted to be slower than the ideal opening adjustment speed if no discharge operation were performed in the acceleration section. The dashed line in the middle section of Figure 7 shows the ideal change in opening when no discharge operation is performed. Similarly, after setting the first deceleration section Ds1, the control unit 101 sets the second acceleration section As2, and after setting the third deceleration section Ds3, it sets the third acceleration section As3. In other embodiments, when the control unit 101 determines the discharge control parameters, it may set a first interval and then set a second interval corresponding to that first interval.

[0052] In the three-dimensional molding apparatus 100 configured as described above, the control unit 101 performs suction and discharge operations by moving the plunger 77 when molding a partial object, and controls the movement of the plunger 77 so that the position of the plunger 77 coincides at the start and end ends of the molding section for molding the partial object. In contrast, if the plunger 77 is not controlled so that its position coincides at the start and end ends of a certain molding section, even if the desired plunger operation can be performed in that molding section, it may not be possible to immediately perform the desired plunger operation in subsequent molding sections. For example, the further the plunger 77 is located from the flow path 69 at the end end of a certain molding section compared to the position of the plunger 77 at the start end of that molding section, the higher the possibility that the suction operation cannot be immediately performed at the start end of the next molding section due to insufficient space to move the plunger 77. If there is insufficient space to perform the suction operation, in order to perform the suction operation, for example, it is necessary to temporarily stop the printing process, position the nozzle 61 in a different area from the printing area, and then perform the delivery operation to secure space for moving the plunger 77. In this embodiment, the movement of the plunger 77 is controlled so that the position of the plunger 77 coincides at the start and end of the printing section. Therefore, it is possible to suppress the shortage of space for moving the plunger 77 in each printing section without interrupting the printing process, and the likelihood of performing the desired plunger operation is increased.

[0053] Furthermore, in this embodiment, the control unit 101 controls the sum of the displacements due to the movement of the plunger 77 corresponding to each acceleration section and the sum of the displacements due to the movement of the plunger 77 corresponding to each deceleration section, thereby aligning the position of the plunger 77 at the start and end ends of the printing section for printing a partial object. Therefore, the position of the plunger 77 at the start and end ends of the printing section can be aligned by a simple method.

[0054] Furthermore, in this embodiment, the control unit 101 executes either a suction operation or a feed operation in the first section in which the scanning speed is accelerated from a first speed to a second speed, and executes the other of either a suction operation or a feed operation in the second section in which the scanning speed is decelerated from a second speed to a first speed, and controls the movement of the plunger 77 so that the amount of movement of the plunger 77 corresponding to the first section matches the amount of movement of the plunger 77 corresponding to the second section. As a result, the movement of the plunger 77 is controlled so that the amount of movement of the plunger 77 corresponding to sections with the same absolute amount of change in scanning speed matches, making it easier to control the movement of the plunger 77 so that the sum of the displacements due to the movement of the plunger 77 corresponding to each acceleration section cancels out the sum of the displacements due to the movement of the plunger 77 corresponding to each deceleration section. Therefore, the position of the plunger 77 can be more easily aligned at the start end and end end of the molding section.

[0055] Furthermore, the control unit 101 controls the discharge volume adjustment unit 70 to make the opening area of ​​the flow path 69 in the second operation smaller than the opening area in the first operation. This makes it possible to suppress excessive discharge volume caused by the increase in pressure in the flow path 69 due to the discharge operation performed in the second operation, compared to, for example, cases where the opening areas are the same in the first and second operations, or cases where the opening area in the second operation is larger than the opening area in the first operation.

[0056] Furthermore, in this embodiment, the control unit 101 performs the second operation before the first operation. Therefore, for example, by performing the first operation while the nozzle 61 is moving at a constant speed, and performing the second operation when decelerating or accelerating the nozzle 61 prior to the first operation, the discharge amount when decelerating or accelerating the nozzle 61 can be controlled with high precision. In other embodiments, the control unit 101 may perform a third operation before the first operation, or it may perform both the second and third operations before the first operation. In this case as well, similarly to the above, the discharge amount when decelerating or accelerating the nozzle 61 can be controlled with high precision.

[0057] B. Second Embodiment: Figure 8 is a diagram illustrating the change in the opening degree of the flow path 69 in the second embodiment. Similar to the middle section of Figure 7, Figure 8 shows the change in the opening degree of the flow path 69 when fabricating the partial object shown in Figure 6. In this embodiment, unlike the first embodiment, when increasing the discharge amount, the control unit 101 controls the discharge amount adjustment unit 70 to gradually increase the opening area of ​​the flow path 69. The configuration of the three-dimensional molding apparatus 100 is the same as in the first embodiment unless otherwise described.

[0058] In this embodiment, when the control unit 101 increases the discharge amount in response to the acceleration section, it controls the discharge amount adjustment unit 70 to increase the opening area of ​​the flow path 69 in three stages. For example, as shown in Figure 8, in the first acceleration section As1, the control unit 101 first increases the opening of the flow path 69 from zero to opening ap1, then from opening ap1 to opening ap2, and further from opening ap2 to opening ap3.

[0059] According to the second embodiment described above, when increasing the discharge amount, the control unit 101 controls the discharge amount adjustment unit 70 to gradually increase the opening area of ​​the flow path 69. In contrast, if the opening area of ​​the flow path 69 is increased all at once to the target opening area, the pressure difference between the upstream and downstream portions of the flow path 69 may cause the molding material to flow out all at once from the upstream portion to the downstream portion. In particular, if the molding material is generated with the opening of the flow path 69 at zero, the pressure in the portion of the flow path 69 upstream of the discharge amount adjustment unit 70 increases. Therefore, if the opening of the flow path 69 is increased all at once in this state, the molding material is likely to flow out all at once from the upstream portion to the downstream portion of the flow path 69. In this embodiment, when increasing the discharge amount, the operation of gradually increasing the opening area of ​​the flow path 69 can suppress the sudden flow of molding material from the upstream portion to the downstream portion of the flow path 69. As a result, the discharge amount can be controlled with greater precision. Furthermore, for example, when performing suction or discharge operations while increasing the discharge volume in an acceleration section, the possibility of more precise control over the discharge volume increases by gradually changing the position of the plunger 77 in accordance with the progressively increasing opening area of ​​the flow path 69.

[0060] In other embodiments, when increasing the discharge volume, the control unit 101 may increase the opening area of ​​the flow path 69 in two or more steps. Furthermore, it is not necessary to increase the opening area in steps in all cases where the discharge volume is increased. Also, when increasing the discharge volume, the control unit 101 may determine whether or not to increase the opening area in steps, and the number of steps if the opening area is increased in steps, based on, for example, the current opening degree or opening area, the difference between the current opening degree or opening area and the target opening degree or opening area, the timing of executing the control to increase the opening area, etc.

[0061] C. Other embodiments: (C-1) In the above embodiment, the discharge volume adjustment unit 70 may be composed of a mechanism using a plunger in which a piston protrudes into the flow path 69 to change the opening area of ​​the flow path 69, or a mechanism using a shutter that moves in a direction intersecting the flow path 69 to change the opening area of ​​the flow path 69. The discharge volume adjustment unit 70 may be composed of a combination of two or more of the butterfly valve of the above embodiment, the shutter mechanism and the plunger mechanism described above.

[0062] (C-2) In the above embodiment, the control unit 101 controls the movement of the plunger 77 so that the amount of movement of the plunger 77 corresponding to the first section matches the amount of movement of the plunger 77 corresponding to the second section. However, the control unit 101 does not have to control the movement of the plunger 77 in this way. For example, the control unit 101 may not make the amount of movement of the plunger 77 corresponding to the first section match the amount of movement of the plunger 77 corresponding to the second section, but simply control the movement of the plunger 77 so that the sum of the displacements of the plunger 77 due to the movement of the plunger 77 corresponding to each acceleration section cancels out the sum of the displacements of the plunger 77 due to the movement of the plunger 77 corresponding to each deceleration section.

[0063] (C-3) In the above embodiment, the control unit 101 controls the sum of the displacements due to the movement of the plunger 77 in each acceleration section and the sum of the displacements due to the movement of the plunger 77 in each deceleration section to make the position of the plunger 77 coincide at the start end and end end of the molding section. However, it is not necessary to control the movement of the plunger 77 in this way. For example, the control unit 101 may control the movement of the plunger 77 so that the position of the plunger 77 coincides at the start end and end end of the molding section by performing suction and discharge operations in the acceleration and deceleration sections, and then performing suction and discharge operations in the sections where the nozzle 61 is not accelerated or decelerated, so as not to affect the molding accuracy, thereby changing the position of the plunger 77 little by little. In this case, for example, the control unit 101 may adjust the opening of the flow path 69 by the discharge amount adjustment unit 70 so that a constant line width is achieved in the sections where the plunger 77 is moved little by little.

[0064] (C-4) In the above embodiment, the control unit 101 performs at least one of the first, second, and third operations in a designated section. Alternatively, the control unit 101 may perform, for example, a fourth operation in a designated section, thereby discharging the molding material from the nozzle opening 62 while performing the suction operation.

[0065] (C-5) In the above embodiment, the control unit 101 makes the opening area in the second operation smaller than the opening area in the first operation. In contrast, the control unit 101 does not have to control the opening area in this way, and for example, it may make the opening area the same in the first and second operations, and make the rotational speed of the screw 40 in the second operation smaller than the rotational speed of the screw 40 in the first operation.

[0066] (C-6) In the above embodiment, the screw 40 is configured as a flat screw. However, the screw 40 does not have to be configured as a flat screw; it may be configured as an inline screw.

[0067] (C-7) In the above embodiment, pelletized ABS resin is used as the raw material supplied to the material supply unit 20. In contrast, the three-dimensional molding apparatus 100 can mold three-dimensional objects using various materials as the main material, such as thermoplastic materials, metal materials, and ceramic materials. "Main material" means the central material that forms the shape of the three-dimensional object, and means a material that accounts for 50% by weight or more of the three-dimensional object. The molding materials mentioned above include those main materials that have been melted individually, and those in which some components contained together with the main material have been melted into a paste.

[0068] When a thermoplastic material is used as the main material, the molding material is generated in the plasticizing section 30 by the plasticization of the material.

[0069] Examples of thermoplastic materials that can be used include the following thermoplastic resin materials. <Examples of thermoplastic resin materials> General-purpose engineering plastics such as 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), polyether ether ketone (PEEK), polycarbonate (PC), modified polyphenylene ether, polybutylene terephthalate, polyethylene terephthalate, and other engineering plastics, as well as polysulfone, polyethersulfone, polyphenylene sulfide, polyarylate, polyimide, polyamide-imide, polyether-imide, and polyether ether ketone.

[0070] The thermoplastic material may contain pigments, metals, ceramics, or other additives such as waxes, flame retardants, antioxidants, and heat stabilizers. In the plasticizing section 30, the thermoplastic material is plasticized and converted into a molten state by the rotation of the screw 40 and heating of the heater 58. The molding material produced by the melting of the thermoplastic material is extruded from the nozzle 61 and then hardens as the temperature decreases.

[0071] It is desirable that thermoplastic materials be heated above their glass transition temperature and injected from the nozzle 61 in a completely molten state. For example, ABS resin has a glass transition temperature of approximately 120°C, and it is desirable that it be approximately 200°C when injected from the nozzle 61.

[0072] In the three-dimensional molding apparatus 100, instead of the thermoplastic material described above, for example, the following metal materials may be used as the main material. In this case, it is desirable that the powder material, which is made by pulverizing the following metal materials, is mixed with components that melt during the production of the molding material, and then introduced into the plasticizing section 30 as raw material. <Examples of metallic materials> A single metal such as magnesium (Mg), iron (Fe), cobalt (Co), or chromium (Cr), aluminum (Al), titanium (Ti), copper (Cu), or nickel (Ni), or an alloy containing one or more of these metals. <Example of the aforementioned alloy> Maraging steel, stainless steel, cobalt-chromium-molybdenum, titanium alloy, nickel alloy, aluminum alloy, cobalt alloy, cobalt-chromium alloy.

[0073] In the three-dimensional molding apparatus 100, ceramic materials can be used as the main material instead of the metal materials mentioned above. Examples of ceramic materials that can be used include oxide ceramics such as silicon dioxide, titanium dioxide, aluminum oxide, and zirconium oxide, as well as non-oxide ceramics such as aluminum nitride. When using metal or ceramic materials as described above as the main material, the molding material placed on the stage 210 may be hardened by sintering using laser irradiation or hot air.

[0074] The metal and ceramic powder materials fed into the material supply unit 20 as raw materials may be mixed materials containing multiple types of single metal powders, alloy powders, or ceramic powders. Furthermore, the metal and ceramic powder materials may be coated with a thermoplastic resin, such as those exemplified above, or other thermoplastic resins. In this case, the thermoplastic resin may melt in the plasticizing unit 30 to achieve fluidity.

[0075] The powder materials of metal and ceramic materials fed into the material supply unit 20 as raw materials may also have solvents added to them, such as those listed below. One or more solvents selected from the following can be used in combination. <Examples of solvents> Water; (poly)alkylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, and propylene glycol monoethyl ether; acetic acid esters such as ethyl acetate, n-propyl acetate, iso-propyl acetate, n-butyl acetate, and iso-butyl acetate; aromatic hydrocarbons such as benzene, toluene, and xylene; ketones such as methyl ethyl ketone, acetone, methyl isobutyl ketone, ethyl-n-butyl ketone, diisopropyl ketone, and acetylacetone; alcohols such as ethanol, propanol, and butanol; tetraalkylammonium acetates; sulfoxide solvents such as dimethyl sulfoxide and diethyl sulfoxide; pyridine solvents such as pyridine, γ-picoline, and 2,6-lutidine; tetraalkylammonium acetate (e.g., tetrabutylammonium acetate); ionic liquids such as butylcarbitol acetate, etc.

[0076] In addition, the following types of binders can be added to the metal and ceramic powder materials that are fed into the material supply unit 20 as raw materials. <Example of a binder> Acrylic resin, epoxy resin, silicone resin, cellulose resin or other synthetic resin, or PLA (polylactic acid), PA (polyamide), PPS (polyphenylene sulfide), PEEK (polyether ether ketone) or other thermoplastic resin.

[0077] D. Other forms: This disclosure is not limited to the embodiments described above, and can be implemented in various forms without departing from its spirit. For example, this disclosure can also be implemented in the following forms. The technical features in the embodiments described below that correspond to the technical features in each of the forms described below can be replaced or combined as appropriate in order to solve some or all of the problems of this disclosure, or to achieve some or all of the effects of this disclosure. Furthermore, if such technical features are not described as essential in this specification, they can be deleted as appropriate.

[0078] (1) According to a first embodiment of the present disclosure, a three-dimensional molding apparatus is provided. The three-dimensional molding apparatus comprises a nozzle having a nozzle opening and discharging molding material from the nozzle opening toward a stage; a position changing unit that changes the relative position between the nozzle and the stage; a discharge volume adjustment unit that communicates with the nozzle opening and is provided in a flow path through which the molding material flows, and adjusts the amount of molding material discharged from the nozzle opening by changing the opening area of ​​the flow path; a pressure adjustment unit having a branch flow path connected to the flow path between the discharge volume adjustment unit and the nozzle opening, and a plunger that moves within the branch flow path; and a control unit that controls the position changing unit, the discharge volume adjustment unit and the pressure adjustment unit. When creating a continuous linear partial object, the control unit moves the plunger to perform a suction operation to draw the material in the flow channel into the branched flow channel, and a discharge operation to discharge the material drawn into the branched flow channel back into the flow channel, controlling the movement of the plunger so that the position of the plunger in the branched flow channel coincides with the start end and end end of the manufacturing section for creating the partial object. With this configuration, the movement of the plunger is controlled so that its position coincides with the start and end of the build section. This reduces the lack of space to move the plunger in each build section without interrupting the build process, and increases the likelihood of performing the desired plunger operation.

[0079] (2) In the above embodiment, the molding section has one or more acceleration sections in which the relative movement speed of the nozzle with respect to the stage is accelerated, and one or more deceleration sections in which the relative movement speed is reduced, and the control unit may make the position of the plunger in the branched flow path coincide at the start end and end end of the molding section by controlling the sum of the displacements due to the movement of the plunger corresponding to each acceleration section and the sum of the displacements due to the movement of the plunger corresponding to each deceleration section. With this embodiment, the position of the plunger can be made to coincide at the start end and end end of the molding section by a simple method.

[0080] (3) In the above embodiment, the control unit may perform either the suction operation or the discharge operation in a first section in which the relative movement speed is accelerated from the first speed to the second speed, and in a second section in which the relative movement speed is decelerated from the second speed to the first speed, it may perform the discharge operation if the suction operation is performed in the first section, and it may perform the suction operation if the discharge operation is performed in the first section, and control the movement of the plunger so that the amount of movement of the plunger in the first section matches the amount of movement of the plunger in the second section. With this embodiment, the movement of the plunger is controlled so that the amount of movement of the plunger in sections in which the absolute amount of change in the nozzle movement speed is the same matches, so that the position of the plunger can be matched at the start end and end end of the molding section more easily.

[0081] (4) In the above configuration, the control unit may perform at least one of the following operations in a designated section of the molding section in which the relative movement of the nozzle with respect to the stage at a constant moving speed is instructed: a first operation in which the flow path is opened by the discharge volume adjustment unit and the molding material is discharged from the nozzle opening without controlling the pressure adjustment unit; a second operation in which the flow path is opened by the discharge volume adjustment unit and the molding material is discharged from the nozzle opening by controlling the pressure adjustment unit and executing the delivery operation; and a third operation in which the flow path is closed by the discharge volume adjustment unit and the molding material is discharged from the nozzle opening by controlling the pressure adjustment unit and executing the delivery operation.

[0082] (5) In the above configuration, the control unit may control the discharge volume adjustment unit to make the opening area in the second operation smaller than the opening area in the first operation. With this configuration, for example, compared to cases where the opening areas are the same in the first and second operations, or where the opening area in the second operation is larger than the opening area in the first operation, it is possible to suppress the discharge volume from becoming excessive due to the increase in pressure in the flow path caused by the discharge operation performed in the second operation.

[0083] (6) In the above configuration, the control unit may perform at least one of the second operation and the third operation before the first operation. With this configuration, for example, the first operation is performed while the nozzle 61 is moving at a constant speed, and the second and third operations are performed when the nozzle 61 is decelerated or accelerated prior to the first operation, thereby enabling precise control of the discharge amount when the nozzle is decelerated or accelerated.

[0084] (7) In the above embodiment, when increasing the discharge amount, the control unit may perform an operation to gradually increase the opening area by controlling the discharge amount adjustment unit. With this embodiment, for example, compared to increasing the opening area of ​​the flow path to the target opening area all at once, it is possible to suppress the rapid flow of the molding material from the part upstream of the discharge amount adjustment unit to the part downstream of the flow path.

[0085] (8) According to a second embodiment of the present disclosure, a method for manufacturing a three-dimensional object in a three-dimensional molding apparatus is provided, comprising: a nozzle having a nozzle opening and discharging a molding material from the nozzle opening toward a stage; a position changing unit for changing the relative position between the nozzle and the stage; a discharge volume adjusting unit communicating with the nozzle opening and provided in a flow path through which the molding material flows, and adjusting the amount of the molding material discharged from the nozzle opening by changing the opening area of ​​the flow path; a branch flow path connected to the flow path between the discharge volume adjusting unit and the nozzle opening; and a pressure adjusting unit having a plunger that moves within the branch flow path. When manufacturing a continuous linear partial object, the manufacturing method comprises the steps of: moving the plunger to draw the molding material in the flow path into the branch flow path; and sending the molding material drawn into the branch flow path back into the flow path, wherein the plunger is moved so that its position within the branch flow path coincides with the start end and end end of the manufacturing section for manufacturing the partial object. [Explanation of Symbols]

[0086] 20...Material supply unit, 22...Supply path, 30...Plasticizing unit, 31...Screw case, 32...Drive motor, 40...Screw, 41...Top surface, 42...Screw bottom surface, 43...Side surface, 44...Material inlet, 45...Groove section, 46...Protruding section, 47...Center section, 50...Barrel, 52...Barrel top surface, 56...Communication hole, 58...Heater, 61...Nozzle, 62...Nozzle opening, 63...Tip surface, 65...Nozzle flow path, 69...Flow path, 70...Discharge volume adjustment unit, 74...First drive unit, 75...Pressure adjustment unit, 76...Branching flow path, 77...Plunger, 78...Second drive unit, 79...End surface, 100...Three-dimensional molding device, 101...Control unit, 200...Discharge unit, 210...Stage, 211...Mounting surface, 230...Position change unit

Claims

1. A nozzle having a nozzle opening, which extrudes molding material toward the stage from the nozzle opening, A position changing unit that changes the relative position between the nozzle and the stage, A discharge volume adjustment unit is provided in the flow path through which the molding material flows, communicating with the nozzle opening, and adjusts the amount of molding material discharged from the nozzle opening by changing the opening area of ​​the flow path. A pressure adjustment unit having a branch channel connected to the flow path between the discharge volume adjustment unit and the nozzle opening, and a plunger that moves within the branch channel, The system comprises a control unit that controls the position changing unit, the discharge volume adjustment unit, and the pressure adjustment unit, The control unit, When creating a single continuous linear partial object, the plunger is moved to perform a suction operation in which the material being created in the flow channel is drawn into the branched flow channel, and a discharge operation in which the material being created drawn into the branched flow channel is discharged back into the flow channel. The movement of the plunger is controlled so that the position of the plunger within the branch channel coincides at the start and end ends of the fabrication section for fabricating the aforementioned partial object. The molding section comprises one or more acceleration sections in which the relative movement speed of the nozzle with respect to the stage is accelerated, and one or more deceleration sections in which the relative movement speed is reduced. A three-dimensional molding apparatus, wherein the control unit controls the sum of the displacements due to the movement of the plunger in each acceleration section and the sum of the displacements due to the movement of the plunger in each deceleration section, thereby causing the position of the plunger within the branched channel to coincide at the start end and end end of the molding section.

2. A three-dimensional molding apparatus according to claim 1, The control unit, In the first section in which the relative moving speed is accelerated from the first speed to the second speed, either the suction operation or the discharge operation is performed. In the second section in which the relative moving speed is reduced from the second speed to the first speed, the discharge operation is performed when the suction operation is performed in the first section, and the suction operation is performed when the discharge operation is performed in the first section. A three-dimensional molding apparatus that controls the movement of the plunger such that the amount of movement of the plunger in the first section matches the amount of movement of the plunger in the second section.

3. A three-dimensional molding apparatus according to claim 1, The control unit, in a designated section of the molding section in which it is instructed to move the nozzle relative to the stage at a constant moving speed, A first operation involves discharging the molding material from the nozzle opening without controlling the pressure adjustment unit, while the flow path is open by the discharge volume adjustment unit. With the flow path opened by the discharge volume adjustment unit, the second operation involves controlling the pressure adjustment unit to perform the discharge operation, thereby discharging the molding material from the nozzle opening. With the flow path closed by the discharge volume adjustment unit, the pressure adjustment unit is controlled to perform the discharge operation, thereby performing at least one of the following: a third operation in which the molding material is discharged from the nozzle opening; Three-dimensional printing equipment.

4. A three-dimensional molding apparatus according to claim 3, The control unit controls the discharge volume adjustment unit to make the opening area in the second operation smaller than the opening area in the first operation, in a three-dimensional molding apparatus.

5. A three-dimensional molding apparatus according to claim 3, The control unit performs at least one of the second operation and the third operation before the first operation, in a three-dimensional molding apparatus.

6. A three-dimensional molding apparatus according to any one of claims 1 to 5, The control unit, when increasing the discharge amount, controls the discharge amount adjustment unit to perform an operation to gradually increase the opening area, thereby enabling the three-dimensional molding apparatus.

7. A nozzle having a nozzle opening, which extrudes molding material toward the stage from the nozzle opening, A position changing unit that changes the relative position between the nozzle and the stage, A discharge volume adjustment unit is provided in the flow path through which the molding material flows, communicating with the nozzle opening, and adjusts the amount of molding material discharged from the nozzle opening by changing the opening area of ​​the flow path. A method for manufacturing a three-dimensional object in a three-dimensional molding apparatus, comprising a pressure adjustment unit having a branched channel connected to the channel between the discharge volume adjustment unit and the nozzle opening, and a plunger that moves within the branched channel, When creating a continuous linear partial object, the plunger is moved to draw the material in the flow channel into the branched flow channel, The process includes a step of sending the molding material that has been drawn into the branched channel back into the channel, The plunger is moved such that its position within the branch channel coincides with the start and end ends of the fabrication section for fabricating the aforementioned partial object. The molding section comprises one or more acceleration sections in which the relative movement speed of the nozzle with respect to the stage is accelerated, and one or more deceleration sections in which the relative movement speed is reduced. A method for manufacturing a three-dimensional object, comprising controlling the sum of the displacements due to the movement of the plunger in each acceleration section and the sum of the displacements due to the movement of the plunger in each deceleration section, thereby causing the position of the plunger within the branched flow path to coincide at the start end and end end of the molding section.

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