Three-dimensional modeling device

Abstract

To provide a three-dimensional molding device that can suppress melting of all materials supplied between a flat screw and a barrel.SOLUTION: A three-dimensional molding device includes: a plasticizing unit having a drive motor, a screw, a barrel, and a first heater to heat the material supplied between the screw and the barrel; a nozzle; a stage; and a control unit. The control unit performs a process of reducing an output of the first heater when at least one of a first condition, a second condition, and a third condition is satisfied. However, the first condition is that a measured value of a first temperature sensor that measures a temperature of the screw or the barrel is greater than a first predetermined value, the second condition is that a torque value of the drive motor is less than a second predetermined value, and the third condition is that the measured value of a pressure sensor that measures a pressure in a flow path between a communication hole and a nozzle opening is less than a third predetermined value.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a three-dimensional modeling apparatus and an injection molding apparatus. [Background technology]

[0002] 2. Description of the Related Art Three-dimensional modeling apparatuses are known that manufacture three-dimensional objects by discharging, layering, and curing a plasticized modeling material.

[0003] For example, Patent Document 1 describes a plasticizing and delivering device that includes a barrel with a material inflow passage opening at one end, a rotor with an end face that slides against the one end face of the barrel, and a spiral groove formed in the end face of the rotor. The spiral groove is supplied with material from a radially outer end, and its radially inner end communicates with the open end of the material inflow passage of the barrel. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2010-241016 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the plasticizing and sending device equipped with the rotor as described above, the material can be stably plasticized by balancing the transport of the material and the melting of the material. Ideally, the material is in a solid state at the material supply section, which is the radially outer end of the spiral groove, and the material is in a molten state toward the radially inner end of the spiral groove. If the material is in a molten state at the supply section, the transport force for transporting the material to the radially inner end cannot be obtained, and the discharge is unstable, and a bridge phenomenon occurs in which new material is not supplied. [Means for solving the problem]

[0006] One aspect of the three-dimensional printing apparatus according to the present invention is to A plasticizing unit that plasticizes the material to generate a modeling material; A nozzle having a nozzle opening and discharging the modeling material; a stage on which the modeling material discharged from the nozzle is laminated; and A control unit that controls the plasticizing unit; Including, The plasticizing section includes: A drive motor; a screw that is rotated by the drive motor and has a groove forming surface on which grooves are formed; a barrel having a surface facing the groove forming surface and having a communication hole; a first heater for heating the material supplied between the screw and the barrel; The control unit performs a process of reducing an output of the first heater when at least one of a first condition, a second condition, and a third condition is satisfied. however, the first condition being that a measurement value of a first temperature sensor measuring a temperature of the screw or the barrel is greater than a first predetermined value; the second condition is that the torque value of the driving motor is smaller than a second predetermined value; The third condition is that a measurement value of a pressure sensor that measures the pressure in the flow passage from the communication hole to the nozzle orifice is smaller than a third predetermined value.

[0007] One aspect of the injection molding apparatus according to the present invention is A plasticizing unit that plasticizes the material to generate a modeling material; a nozzle having a nozzle opening and configured to inject the molding material supplied from the plasticizing unit into a mold; A control unit that controls the plasticizing unit; Including, The plasticizing section includes: A drive motor; a screw that is rotated by the drive motor and has a groove forming surface on which grooves are formed; a barrel having a surface facing the groove forming surface and having a communication hole; a first heater for heating the material supplied between the screw and the barrel; The control unit performs a process of reducing an output of the first heater when at least one of a first condition, a second condition, and a third condition is satisfied. however, the first condition being that a measurement value of a first temperature sensor measuring a temperature of the screw or the barrel is greater than a first predetermined value; the second condition is that the torque value of the driving motor is smaller than a second predetermined value; The third condition is that a measurement value of a pressure sensor that measures the pressure in the flow passage from the communication hole to the nozzle orifice is smaller than a third predetermined value. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a cross-sectional view illustrating a three-dimensional modeling apparatus according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a perspective view illustrating a flat screw of the three-dimensional modeling apparatus according to the embodiment. [Diagram 3] FIG. 2 is a plan view illustrating a barrel of the three-dimensional modeling apparatus according to the embodiment. [Figure 4] FIG. 2 is a cross-sectional view illustrating a barrel of the three-dimensional modeling apparatus according to the embodiment. [Diagram 5] 5 is a flowchart for explaining a process of a control unit of the three-dimensional printing apparatus according to the embodiment. [Figure 6] FIG. 4 is a cross-sectional view illustrating a three-dimensional modeling apparatus according to a first modified example of the embodiment. [Figure 7] FIG. 1 is a cross-sectional view illustrating an injection molding apparatus according to an embodiment of the present invention. [Figure 8] 6 is a graph showing the relationship between measurement time and the measurement value of a first temperature sensor. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Preferred embodiments of the present invention will be described in detail below with reference to the drawings. Note that the embodiments described below do not unduly limit the contents of the present invention described in the claims. In addition, not all of the configurations described below are necessarily essential components of the present invention.

[0010] 1. Three-dimensional printing equipment 1.1. Overall structure First, a three-dimensional modeling apparatus according to this embodiment will be described with reference to the drawings. Fig. 1 is a cross-sectional view that shows a three-dimensional modeling apparatus 100 according to this embodiment. In Fig. 1, an X-axis, a Y-axis, and a Z-axis are shown as three mutually orthogonal axes. The X-axis direction and the Y-axis direction are, for example, horizontal directions. The Z-axis direction is, for example, vertical directions.

[0011] As shown in FIG. 1, the three-dimensional modeling apparatus 100 includes, for example, a modeling unit 10, a stage 20, a moving mechanism 30, and a control unit 40.

[0012] The three-dimensional modeling apparatus 100 supplies plasticized liquid to the stage 20 from the nozzle 180 of the modeling unit 10. While discharging the modeling material, the moving mechanism 30 is driven to change the relative position between the nozzle 180 and the stage 20. In this way, the 3D modeling device 100 models a 3D object having a desired shape on the stage 20. The detailed configuration of the modeling unit 10 will be described later.

[0013] The stage 20 is moved by a movement mechanism 30. A modeling material discharged from a nozzle 180 is layered on a modeling surface 22 of the stage 20 to form a three-dimensional object.

[0014] The movement mechanism 30 changes the relative position between the modeling unit 10 and the stage 20. In the illustrated example, the movement mechanism 30 moves the stage 20 relative to the modeling unit 10. The movement mechanism 30 is configured by, for example, a three-axis positioner that moves the stage 20 in the X-axis direction, the Y-axis direction, and the Z-axis direction by the driving forces of three motors 32. The motors 32 are controlled by a control unit 40.

[0015] Note that the moving mechanism 30 may be configured to move the modeling unit 10 without moving the stage 20. Alternatively, the moving mechanism 30 may be configured to move both the modeling unit 10 and the stage 20.

[0016] The control unit 40 is configured, for example, by a computer having a processor, a main storage device, and an input / output interface that inputs and outputs signals from and to the outside. The control unit 40 performs various functions, for example, by the processor executing a program loaded into the main storage device. The control unit 40 controls the modeling unit 10 and the moving mechanism 30. Specific processing of the control unit 40 will be described later. Note that the control unit 40 may be configured by a combination of multiple circuits instead of a computer.

[0017] 1.2. Modeling unit As shown in FIG. 1, the modeling unit 10 includes, for example, a material input unit 110, a plasticizing unit 120, a nozzle 180, and a pressure sensor 190.

[0018] Pellet- or powder-like materials are fed into the material feed section 110. Examples of materials fed into the material feed section 110 include MIM (Metal Injection Molding) materials that contain metal particles and thermoplastic resin.

[0019] Examples of the material of the metal particles of the MIM material fed into the material feeding section 110 include single metals such as magnesium (Mg), iron (Fe), cobalt (Co), chromium (Cr), aluminum (Al), titanium (Ti), copper (Cu), and nickel (Ni), or alloys containing one or more of these metals, as well as maraging steel, stainless steel, cobalt chromium molybdenum, titanium alloys, nickel alloys, aluminum alloys, cobalt alloys, and cobalt chromium alloys.

[0020] Examples of the plastic resin of the MIM material fed into the material feeding section 110 include general-purpose engineering plastics such as polypropylene (PP), polyethylene (PE), polyacetal (POM), polyvinyl chloride (PVC), polyamide (PA), acrylonitrile butadiene styrene (ABS), polylactic acid (PLA), polyphenylene sulfide (PPS), polycarbonate (PC), modified polyphenylene ether, polybutylene terephthalate, and polyethylene terephthalate, as well as engineering plastics such as polysulfone, polyethersulfone, polyphenylene sulfide, polyarylate, polyimide, polyamideimide, polyetherimide, and polyetheretherketone (PEEK).

[0021] The material input section 110 is configured by, for example, a hopper. The material input unit 110 is connected to the plasticizing unit 120 via a supply path 112 provided below the material input unit 110. The material input into the material input unit 110 is supplied to the plasticizing unit 120 via the supply path 112.

[0022] The plasticizing unit 120 has, for example, a screw case 122, a drive motor 124, a flat screw 130, a barrel 140, a first heater 150, a second heater 152, a chiller 160, a first temperature sensor 170, and a second temperature sensor 172. The plasticizing unit 120 plasticizes the solid-state material supplied from the material supply unit 110, generates a paste-like modeling material having fluidity, and supplies the paste-like modeling material to the nozzle 180.

[0023] Plasticization is a concept that includes melting, and refers to changing a material from a solid to a fluid state. Specifically, for materials that undergo glass transition, plasticization refers to raising the temperature of the material above the glass transition point. For materials that do not undergo glass transition, plasticization refers to raising the temperature of the material above the melting point.

[0024] The screw case 122 is a housing that houses the flat screw 130. A barrel 140 is provided on the lower surface of the screw case 122. The flat screw 130 is housed in a space surrounded by the screw case 122 and the barrel 140.

[0025] The drive motor 124 is provided on the upper surface of the screw case 122. The drive motor 124 is, for example, a servo motor. A shaft 126 of the drive motor 124 is connected to an upper surface 131 of the flat screw 130. The drive motor 124 is controlled by the control unit 40.

[0026] The flat screw 130 has a generally cylindrical shape whose size in the direction of the rotation axis RA is smaller than the size in the direction perpendicular to the direction of the rotation axis RA. In the illustrated example, the rotation axis RA is parallel to the Z axis. The torque generated by the drive motor 124 causes the flat screw 130 to rotate about the rotation axis RA. The flat screw 130 has an upper surface 131, a groove-forming surface 132 opposite to the upper surface 131, and a side surface 133 connecting the upper surface 131 and the groove-forming surface 132. A first groove 134 is provided in the groove-forming surface 132. Here, FIG. 2 is a perspective view showing the flat screw 130 in a schematic manner. For convenience, FIG. 2 shows a state in which the vertical positional relationship is reversed from the state shown in FIG. 1. Also, FIG. 1 shows the flat screw 130 in a simplified form.

[0027] As shown in FIG. 2, the first groove 134 is provided on the groove forming surface 132 of the flat screw 130. The first groove 134 has, for example, a central portion 135, a groove connecting portion 136, and a material introduction portion 137. The central portion 135 faces a communication hole 146 provided in the barrel 140. The central portion 135 communicates with the communication hole 146. The groove connecting portion 136 connects the central portion 135 and the material introduction portion 137. In the illustrated example, the groove connecting portion 136 is provided in a spiral shape from the central portion 135 toward the outer periphery of the groove forming surface 132. The material introduction portion 137 is provided on the outer periphery of the groove forming surface 132. That is, the material introduction portion 137 is provided on the side surface 133 of the flat screw 130. The material supplied from the material input section 110 is introduced into the first groove 134 from the material introduction section 137, and is transported to the communication hole 146 provided in the barrel 140 through the groove connection section 136 and the central section 135. The number of the first grooves 134 is not particularly limited, and two or more first grooves 134 may be provided.

[0028] As shown in FIG. 1, the barrel 140 is provided below the flat screw 130. The barrel 140 has an opposing surface 142 that faces the groove forming surface 132 of the flat screw 130. A communication hole 146 that communicates with the first groove 134 is provided at the center of the opposing surface 142. Here, Fig. 3 is a plan view that shows a schematic view of the barrel 140. For convenience, the barrel 140 is shown in a simplified form in Fig. 1.

[0029] As shown in FIG. 3, the opposing surface 142 of the barrel 140 is provided with a second groove 144 and a communication hole 146. A plurality of second grooves 144 are provided. In the illustrated example, six second grooves 144 are provided, but the number is not particularly limited. The plurality of second grooves 144 are provided around the communication hole 146 in a plan view. In the illustrated example, the plan view is seen from the Z-axis direction. One end of the second groove 144 is connected to the communication hole 146, and the second groove 144 extends in a spiral shape from the communication hole 146 toward the outer periphery 148 of the barrel 140. The second groove 144 has a function of guiding the modeling material to the communication hole 146.

[0030] The shape of the second groove 144 is not particularly limited, and may be, for example, linear. One end of the second groove 144 does not have to be connected to the communication hole 146. Furthermore, the second groove 144 does not have to be provided on the opposing surface 142. However, in consideration of efficiently guiding the molding material to the communication hole 146, it is preferable that the second groove 144 is provided on the opposing surface 142.

[0031] The first heater 150 and the second heater 152 are provided in the barrel 140 as shown in FIG. 1. The heaters 150 and 152 heat the material supplied between the flat screw 130 and the barrel 140. The heaters 150 and 152 are controlled by the control unit 40. Here, FIG. 4 is a schematic diagram of the three-dimensional modeling apparatus 100 shown in FIG. 1. IV - IV FIG.

[0032] As shown in FIG. 4, the first heater 150 is composed of a pair of rod heaters 151. The second heater 152 is provided between the pair of rod heaters 151. The second heater 152 is composed of a pair of rod heaters 153. The communication hole 146 is provided between the pair of rod heaters 153. The second heater 152 is provided closer to the communication hole 146 than the first heater 150. That is, the distance between the second heater 152 and the communication hole 146 is smaller than the distance between the first heater 150 and the communication hole 146. The control unit 40 controls the heaters 150 and 152 so that the temperature of the second heater 152 is higher than the temperature of the first heater 150. The rod heaters 151 and 153 may be ceramic heaters or electric wire heaters.

[0033] Although not shown, the second heater 152 does not necessarily have to be provided. In addition to the first heater 150 and the second heater 152, a third heater may be provided.

[0034] The chiller 160 is provided in the barrel 140. The chiller 160 has, for example, a cooling flow path 162, an inlet 164, and an outlet 166. In the illustrated example, the cooling flow path 162 is provided along the outer periphery 148 of the barrel 140. The cooling flow path 162 is provided so as to surround the communication hole 146 and the heaters 150, 152 in a plan view. The chiller 160 cools the material supplied from the material input section 110 to the first groove 134. The heaters 150, 152 and the chiller 160 form a temperature gradient in which the temperature gradually increases from the outer periphery 148 of the barrel 140 toward the communication hole 146.

[0035] A refrigerant is introduced into the cooling flow passage 162 from an inlet 164. The refrigerant introduced from the inlet 164 flows through the cooling flow passage 162 and is discharged from an outlet 166. The chiller 160 circulates the refrigerant from the outlet 166 to the inlet 164 while cooling the refrigerant. Examples of the refrigerant include water and industrial water.

[0036] There is no particular limitation on the positions at which the heaters 150, 152 and the chiller 160 are provided. Although not shown, the heaters 150, 152 and the chiller 160 may be provided in the screw case 122 or in the flat screw 130.

[0037] The first temperature sensor 170 and the second temperature sensor 172 are provided in the barrel 140. The temperature sensors 170, 172 measure the temperature of the barrel 140. The temperature sensors 170, 172 are, for example, a thermocouple, a thermistor, an infrared sensor, or the like.

[0038] The first temperature sensor 170 is provided in the outer region 140a of the barrel 140. The first temperature sensor 170 measures the temperature of the outer region 140a. The outer region 140a is a region closer to the outer periphery 148 of the barrel 140 than the communication hole 146. The second temperature sensor 172 is provided in the inner region 140b of the barrel 140. The second temperature sensor 172 measures the temperature of the inner region 140b. The inner region 140b is a region closer to the communication hole 146 than the outer periphery 148 of the barrel 140. The distance from the boundary B between the outer region 140a and the inner region 140b to the communication hole 146 is equal to the distance from the boundary B to the outer periphery 148.

[0039] The first temperature sensor 170 is provided outside the first heater 150. In other words, the first temperature sensor 170 is not provided between the pair of rod heaters 151 that constitute the first heater 150. The second temperature sensor 172 is provided inside the second heater 152. In other words, the second temperature sensor 172 is provided between the pair of rod heaters 153 that constitute the second heater 152. The control unit 40 controls the first heater 150 based on the measurement value of the first temperature sensor 170. The control unit 40 controls the second heater 152 based on the measurement value of the second temperature sensor 172.

[0040] Although not shown, the temperature sensors 170 and 172 may be provided on the flat screw 130 to measure the temperature of the flat screw 130. The second temperature sensor 172 does not have to be provided. In addition to the first temperature sensor 170 and the second temperature sensor 172, a third temperature sensor may be provided.

[0041] The nozzle 180 is provided below the barrel 140. The nozzle 180 ejects the modeling material supplied from the plasticizing unit 120 toward the stage 20. The nozzle 180 is provided with a nozzle flow path 182 and a nozzle hole 184. The nozzle flow path 182 is connected to the communication hole 146. The nozzle hole 184 is connected to the nozzle flow path 182. The nozzle hole 184 is also called a nozzle opening, and is an opening provided at the tip of the nozzle 180. The planar shape of the nozzle hole 184 is, for example, circular. The modeling material supplied to the nozzle flow path 182 from the communication hole 146 is ejected from the nozzle hole 184.

[0042] 1, the pressure sensor 190 is provided in the nozzle 180. The pressure sensor 190 measures the pressure inside the nozzle 180. In the example shown, the pressure sensor 190 is provided in the nozzle flow path 182 and measures the pressure of the nozzle flow path 182. Note that the pressure sensor 190 may be configured to measure the pressure of the flow path from the communication hole 146 to the nozzle hole 184, and the pressure sensor 190 may be provided in the communication hole 146 or in the nozzle flow path 182.

[0043] 1.3. Control Section The control unit 40 controls the plasticizing unit 120. Specifically, the control unit 40 controls the drive motor 124 and the heaters 150, 152. FIG 5 is a flowchart for explaining the processing of the control unit 40.

[0044] The user, for example, operates an operation unit (not shown) to give the control unit 40 a command to start processing. The control unit 40 outputs a processing start signal. The operation unit is realized by, for example, a mouse, a keyboard, a touch panel, etc. The control unit 40 starts processing when it receives the processing start signal.

[0045] As shown in Fig. 5, the control unit 40 performs a process of starting calibration of the line width of the modeling material in step S1. Specifically, the control unit 40 drives the plasticizing unit 120 and the moving mechanism 30 to discharge the modeling material from the nozzle 180, and starts calibration of the line width of the modeling material discharged onto the stage 20. In the calibration, the control unit 40 acquires the line width of the modeling material from, for example, a sensor not shown, and controls the drive motor 124 so that the acquired line width becomes a preset value. The set value is stored, for example, in a storage unit not shown. The storage unit is realized by, for example, a RAM (Random Access Memory).

[0046] Next, in step S2, the control unit 40 performs a process of acquiring the measurement value Tt of the first temperature sensor 170, the torque value Ft of the drive motor 124, and the measurement value Pt of the pressure sensor 190. Tt, Ft, and Pt are acquired during the calibration process. The order in which Tt, Ft, and Pt are acquired is not particularly limited.

[0047] Next, the control unit 40 performs a process of setting a first predetermined value, a second predetermined value, and a third predetermined value in step S3. The first predetermined value, the second predetermined value, and the third predetermined value are values ​​that become first threshold values ​​in the measurement value of the first temperature sensor 170, the torque value of the drive motor 124, and the measurement value of the pressure sensor 190, respectively.

[0048] Furthermore, the control unit 40 performs a process of setting a fourth predetermined value, a fifth predetermined value, and a sixth predetermined value. The fourth predetermined value is a value larger than the first predetermined value. The fifth predetermined value is a value smaller than the second predetermined value. The sixth predetermined value is a value smaller than the third predetermined value. The fourth predetermined value, the fifth predetermined value, and the sixth predetermined value are values ​​that become second threshold values ​​in the measurement value of the first temperature sensor 170, the torque value of the drive motor 124, and the measurement value of the pressure sensor 190, respectively.

[0049] The control unit 40 sets the first to sixth predetermined values, for example, based on information on the type of material included in the processing start signal and Tt, Ft, and Pt acquired in step S2. The first to sixth predetermined values ​​differ depending on the type of material input into the material input unit 110. For example, the storage unit stores a table correlating the type of material with the first to sixth predetermined values, and the control unit 40 sets the first to sixth predetermined values ​​based on the information on the type of material included in the processing start signal and the table.

[0050] Next, in step S4, the control unit 40 performs a process of determining whether or not the calibration of the line width of the modeling material has been completed. If it is determined that the acquired line width is not the set value, the control unit 40 determines that the calibration has not been completed ("NO" in step S4) and repeats the calibration process until the acquired line width becomes the set value. On the other hand, if it is determined that the acquired line width is the predetermined value, the control unit 40 determines that the calibration has been completed ("YES" in step S4) and proceeds to step S5.

[0051] In step S5, the control unit 40 performs a process of starting the modeling of a three-dimensional object. Specifically, the control unit 40 drives the plasticizing unit 120 and the moving mechanism 30 based on modeling data for modeling a three-dimensional object, thereby discharging the modeling material from the nozzle 180 and starting the modeling of a three-dimensional object. The modeling data is generated, for example, by slicer software installed in a computer connected to the three-dimensional modeling device 100. The control unit 40 acquires the modeling data from a computer connected to the three-dimensional modeling device 100 or a recording medium such as a Universal Serial Bus (USB) memory.

[0052] Next, in Step S6, the control unit 40 performs a process of acquiring a measurement value Tb of the first temperature sensor 170, a torque value Fb of the drive motor 124, and a measurement value Pb of the pressure sensor 190. Tb, Fb, and Pb are acquired during the modeling process of the three-dimensional object. The order of acquiring Tb, Fb, and Pb is not particularly limited.

[0053] Next, in step S7, the control unit 40 performs a process of determining whether or not at least one of the first condition, the second condition, and the third condition is satisfied. The first to third conditions are as follows.

[0054] First condition: the measurement value Tb of the first temperature sensor 170 is greater than a first predetermined value Tt1. Second condition: the torque value Fb of the drive motor 124 is smaller than a second predetermined value Ft1. Third condition: the measurement value Pb of the pressure sensor 190 is smaller than a third predetermined value Pt1.

[0055] In the first to third conditions, the predetermined values ​​Tt1, Ft1, and Pt1 are the values ​​set in step S3. When the material input to the material input unit 110 is MIM, for example, Tt obtained in step S2 is 70°C, and Tt1 is 75°C, which is obtained by adding 5°C to Tt of 70°C.

[0056] If it is determined that none of the first, second, and third conditions are satisfied ("NO" in step S7), the control unit 40 returns to step S6 and performs the process of acquiring Tb, Fb, and Pb. On the other hand, if it is determined that at least one of the first, second, and third conditions is satisfied ("YES" in step S7), the control unit 40 proceeds to step S8.

[0057] In step S8, the control unit 40 performs a process of reducing the output of the first heater 150. In this process, the control unit 40 may stop the output of the first heater 150 by reducing the output value of the first heater 150 to zero.

[0058] Next, in step S9, the control unit 40 performs a process of acquiring the measurement value Tb of the first temperature sensor 170, the torque value Fb of the drive motor 124, and the measurement value Pb of the pressure sensor 190. The order in which Tb, Fb, and Pb are acquired is not particularly limited.

[0059] Next, the control unit 40 performs a process of determining whether or not at least one of the first condition, the second condition, and the third condition is satisfied in step S10. If it is determined that none of the first condition, the second condition, and the third condition is satisfied ("NO" in step S10), the control unit 40 proceeds to step S11. For example, even if the first condition is satisfied in step S7, the output of the first heater 150 may be reduced in step S8, so that the first condition is not satisfied in step S10.

[0060] In step S11, the control unit 40 performs a process of increasing the output of the first heater 150 to a predetermined value. If the output of the first heater 150 is stopped in step S8, the control unit 40 starts the first heater 150 to increase the output of the first heater 150 to a predetermined value. After that, the control unit 40 returns to step S6 and performs a process of acquiring Tb, Fb, and Pb.

[0061] On the other hand, in step S10, when it is determined that at least one of the first condition, the second condition, and the third condition is satisfied ("YES" in step S10), the control unit 40 proceeds to step S12.

[0062] In step S12, the control unit 40 determines whether at least one of the fourth condition, the fifth condition, and the sixth condition is satisfied. Then, a process is performed to determine whether or not at least one of the following conditions is satisfied. The fourth to sixth conditions are as follows.

[0063] Fourth condition: the measurement value Tb of the first temperature sensor 170 is greater than a fourth predetermined value Tt2. Fifth condition: The torque value Fb of the drive motor 124 is smaller than a fifth predetermined value Ft2. Sixth condition: the measurement value Pb of the pressure sensor 190 is smaller than a sixth predetermined value Pt2.

[0064] In the fourth to sixth conditions, the predetermined values ​​Tt2, Ft2, and Pt2 are values ​​set in step S3. The fourth predetermined value Tt2 is a value larger than the first predetermined value Tt1. When the material is MIM, for example, Tt obtained in step S2 is 70°C, and Tt2 is 80°C, which is obtained by adding 10°C to Tt (70°C). The fifth predetermined value Ft2 is a value smaller than the second predetermined value Ft1. The sixth predetermined value Pt2 is a value smaller than the third predetermined value Pt1.

[0065] If it is determined that none of the fourth, fifth, and sixth conditions are satisfied ("NO" in step S12), the control unit 40 returns to step S9 and performs the process of acquiring Tb, Fb, and Pb. On the other hand, if at least one of the fourth, fifth, and sixth conditions is satisfied ("YES" in step S12), the control unit 40 proceeds to step S13.

[0066] In step S13, the control unit 40 performs a process to stop the output of the second heater 152. Note that even if the output of the second heater 152 is stopped, the output of the chiller 160 is not stopped. If the output of the chiller 160 is stopped, and if the chiller 160 has a seal ring made of rubber, the seal ring will melt due to heat. If the seal ring melts, water leakage will occur. Therefore, the drive of the chiller 160 is maintained.

[0067] Next, in step S14, the control unit 40 stops the output of the drive motor 124 and performs a process of generating an error signal. The error signal is a signal for notifying the user that the material is melting in the material introduction portion 137 of the first groove 134 provided in the flat screw 130, that is, that all of the material supplied between the flat screw 130 and the barrel 140 is melting. The control unit 40 outputs the error signal to, for example, a display unit (not shown), and causes the display unit to display error information. This allows the three-dimensional modeling apparatus 100 to notify the user of the error information. The display unit is realized by, for example, a liquid crystal display.

[0068] The 3D printing apparatus 100 may notify the user of the error information by sound or vibration. The order of steps S13 and S14 is not particularly limited.

[0069] Thereafter, the control unit 40 ends the process.

[0070] 1.4. Effects In the three-dimensional modeling apparatus 100, the control unit 40 performs a process of reducing the output of the first heater 150 when at least one of the first condition, the second condition, and the third condition is satisfied. Therefore, in the three-dimensional modeling apparatus 100, the temperature between the flat screw 130 and the barrel 140 can be reduced compared to a case where the output of the first heater is not reduced even if at least one of the first condition, the second condition, and the third condition is satisfied. This makes it possible to prevent the material supplied between the flat screw 130 and the barrel 140 from melting completely (total melting). As a result, it is possible to prevent the bridge phenomenon and realize stable plasticization.

[0071] For example, as a first condition, the measurement value of the first temperature sensor 170 is greater than a first predetermined value. As the second condition, when the torque value of the drive motor 124 is smaller than the second predetermined value, it indicates that the material has a high temperature and therefore may be completely melted. As the third condition, when the measurement value of the pressure sensor 190 is smaller than the third predetermined value, it indicates that the material has melted and therefore the viscosity of the material is low and therefore may be completely melted.

[0072] In the three-dimensional modeling apparatus 100, the control unit 40 stops the output of the first heater 150 in the process of reducing the output of the first heater 150. Therefore, in the three-dimensional modeling apparatus 100, the temperature between the flat screw 130 and the barrel 140 can be further reduced.

[0073] In the three-dimensional modeling apparatus 100, the plasticizing unit 120 has a second heater 152 that is provided closer to the communication hole 146 than the first heater 150. Therefore, in the three-dimensional modeling apparatus 100, even if the output of the first heater 150 is reduced, the second heater 152 can keep the temperature near the communication hole 146 high.

[0074] In the three-dimensional modeling apparatus 100, the control unit 40 performs a process of lowering the output of the first heater 150, and then performs a process of stopping the output of the second heater 152 when at least one of the fourth condition, the fifth condition, and the sixth condition is satisfied. Therefore, in the three-dimensional modeling apparatus 100, the temperature between the flat screw 130 and the barrel 140 can be further lowered.

[0075] In the 3D printing apparatus 100, when at least one of the fourth condition, the fifth condition, and the sixth condition is satisfied, a process of stopping the output of the drive motor 124 and generating an error signal is performed. Therefore, in the 3D printing apparatus 100, it is possible to notify the user that an error has occurred while reducing the amount of material that is wasted.

[0076] In the three-dimensional modeling apparatus 100, the first temperature sensor 170 measures the temperature of the outer region 140a, which is closer to the outer periphery 148 of the barrel 140 than the communication hole 146. Therefore, in the three-dimensional modeling apparatus 100, by monitoring the temperature measured by the first temperature sensor 170, it is possible to prevent the material from melting in the outer region 140a of the barrel 140.

[0077] In the three-dimensional modeling apparatus 100, the plasticizing unit 120 has a second temperature sensor 172 that measures the temperature of the inner region 140b that is closer to the communication hole 146 than the outer periphery 148 of the barrel 140, and the control unit 40 controls the first heater 150 based on the measurement value of the first temperature sensor 170, and controls the second heater 152 based on the measurement value of the second temperature sensor 172. Therefore, in the three-dimensional modeling apparatus 100, the control unit 40 can control the first heater 150 and the second heater 152 independently.

[0078] In the three-dimensional modeling apparatus 100, the first temperature sensor 170 is provided outside the first heater 150, and the second temperature sensor 172 is provided inside the second heater 152. Therefore, in the three-dimensional modeling apparatus 100, it is possible to reduce the influence of the second heater 152 on the first temperature sensor 170 and the influence of the first heater 150 on the second temperature sensor 172, compared to, for example, a case in which both temperature sensors are provided outside the first heater or a case in which both temperature sensors are provided inside the second heater.

[0079] In the three-dimensional modeling apparatus 100, the first, second, and third predetermined values ​​differ depending on the type of material. Therefore, in the three-dimensional modeling apparatus 100, optimal values ​​for each material can be set as the first, second, and third predetermined values.

[0080] The material fed into the material feed section 110 may contain ceramic materials in addition to metal particles and thermoplastic resin. Examples of the ceramic materials include oxide ceramics such as silicon dioxide, titanium dioxide, aluminum oxide, and zirconium oxide, and non-oxide ceramics such as aluminum nitride. Furthermore, additives such as pigments, wax, flame retardants, antioxidants, and heat stabilizers may be mixed into the material.

[0081] Furthermore, a binder may be added to the material input into the material input unit 110. Examples of binders include acrylic resin, epoxy resin, silicone resin, cellulose-based resin, other synthetic resins, PLA (polylactic acid), PA (polyamide), PPS (polyphenylene sulfide), and PEEK (polyether ether ketone).

[0082] In addition, in the above example, a flat screw 130 whose size in the direction of the rotation axis RA is smaller than its size in the direction perpendicular to the direction of the rotation axis RA is used as the screw, but instead of the flat screw 130, a rod-shaped in-line screw that is long in the direction of the rotation axis RA may be used.

[0083] 2. Modifications of the 3D printing device 2.1. First variant Next, a three-dimensional modeling apparatus according to a first modified example of this embodiment will be described with reference to the drawings. Fig. 6 is a cross-sectional view that illustrates a barrel 140 of a three-dimensional modeling apparatus 200 according to a first modified example of this embodiment.

[0084] Hereinafter, in the 3D printing apparatus 200 according to the first modified example of this embodiment, the same reference numerals are used for components having the same functions as the components of the 3D printing apparatus 100 according to this embodiment described above, and detailed description thereof will be omitted. This is also true for the 3D printing apparatus according to the second modified example of this embodiment described below.

[0085] In the above-described three-dimensional modeling apparatus 100, the first heater 150 is composed of a pair of rod heaters 151, and the second heater 152 is composed of a pair of rod heaters 153, as shown in FIG.

[0086] In contrast, in the three-dimensional modeling apparatus 200, as shown in FIG. 6, the first heater 150 and the second heater 152 are ring heaters. The heaters 150 and 152 have a shape surrounding the communication hole 146 in a plan view. In the illustrated example, the first heater 150 surrounds the second heater 152. The second heater 152 surrounds the communication hole 146. The first heater 150 is provided, for example, in the outer region 140a of the barrel 140. The second heater 152 is provided, for example, in the inner region 140b of the barrel 140. The first temperature sensor 170 is provided outside the first heater 150. The second temperature sensor 172 is provided inside the second heater 152.

[0087] In the three-dimensional printing apparatus 200, the first heater 150 and the second heater 152 have a shape that surrounds the communication hole 146. Therefore, compared to, for example, a case in which the first heater and the second heater are configured as rod-shaped heaters, it is easy to form a temperature gradient in which the temperature gradually increases from the outer periphery 148 of the barrel 140 toward the communication hole 146.

[0088] The heaters 150, 152 are not limited to ring heaters as long as the heaters 150, 152 have a shape that surrounds the communication hole 146. Although not shown, the heaters 150, 152 may have a polygonal shape.

[0089] 2.2. Second variant Next, a 3D printing apparatus according to a second modified example of this embodiment will be described. In the above-described 3D printing apparatus 100, MIM is used as a material for printing a 3D object.

[0090] In contrast, the three-dimensional printing apparatus according to the second modification of this embodiment can use materials other than MIM as the main material for forming a three-dimensional object, such as materials having thermoplastic properties, metal materials, ceramic materials, etc. Here, the "main material" refers to a material that is the core material forming the shape of the three-dimensional object and that occupies 50% by mass or more in the three-dimensional object. The above-mentioned materials include those main materials melted alone and those in which some components contained together with the main material are melted and made into a paste.

[0091] Examples of the thermoplastic material include thermoplastic resins, such as general-purpose engineering plastics such as polypropylene (PP), polyethylene (PE), polyacetal (POM), polyvinyl chloride (PVC), polyamide (PA), acrylonitrile-butadiene-styrene (ABS), polylactic acid (PLA), polyphenylene sulfide (PPS), polycarbonate (PC), modified polyphenylene ether, polybutylene terephthalate, and polyethylene terephthalate, and engineering plastics such as polysulfone, polyethersulfone, polyphenylene sulfide, polyarylate, polyimide, polyamideimide, polyetherimide, and polyetheretherketone (PEEK).

[0092] The thermoplastic material may contain additives such as pigments, metals, ceramics, and wax, flame retardants, antioxidants, and heat stabilizers. The thermoplastic material is plasticized and converted into a molten state in the plasticizing section 120 by the rotation of the flat screw 130 and the heating of the heaters 150 and 152. The modeling material thus generated is hardened by a decrease in temperature after being discharged from the nozzle 180. It is desirable that the thermoplastic material be discharged from the nozzle 180 in a completely molten state by being heated to or above its glass transition point.

[0093] In the plasticizing unit 120, for example, a metal material may be used as the main material instead of the above-mentioned material having thermoplasticity. In this case, it is preferable that a component that melts when generating the modeling material is mixed with a powder material made by powdering the metal material, and then the powder material is introduced into the plasticizing unit 120.

[0094] Examples of metal materials include single metals such as magnesium (Mg), iron (Fe), cobalt (Co), chromium (Cr), aluminum (Al), titanium (Ti), copper (Cu), and nickel (Ni), or alloys containing one or more of these metals, as well as maraging steel, stainless steel, cobalt-chromium-molybdenum, titanium alloys, nickel alloys, aluminum alloys, cobalt alloys, and cobalt-chromium alloys.

[0095] Instead of the above-mentioned metal materials, a ceramic material can be used as the main material in the plasticizing portion 120. Examples of the ceramic material include oxide ceramics such as silicon dioxide, titanium dioxide, aluminum oxide, and zirconium oxide, and non-oxide ceramics such as aluminum nitride.

[0096] The powder material of the metal material or ceramic material fed into the material feed section 110 may be a mixture of a single metal powder, an alloy powder, or a ceramic material powder. In addition, the powder material of the metal material or ceramic material may be coated with, for example, the above-mentioned thermoplastic resin or other thermoplastic resin. In this case, the thermoplastic resin may be melted in the plasticizing section 120 to exhibit fluidity.

[0097] For example, a solvent may be added to the powder material of the metal material or ceramic material fed into the material feed unit 110. Examples of the solvent include 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; acetates 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-based solvents such as dimethyl sulfoxide and diethyl sulfoxide; pyridine-based solvents such as pyridine, γ-picoline, and 2,6-lutidine; tetraalkylammonium acetates (for example, tetrabutylammonium acetate, etc.); and ionic liquids such as butyl carbitol acetate.

[0098] 3. Injection molding equipment Next, the injection molding apparatus according to this embodiment will be described with reference to the drawings. Fig. 7 is a cross-sectional view that shows a schematic diagram of an injection molding apparatus 900 according to this embodiment.

[0099] 7, the injection molding apparatus 900 includes, for example, a material input section 110, a plasticizing section 120, a nozzle 180, a pressure sensor 190, an injection mechanism 910, a mold section 920, and a mold clamping device 930. The plasticizing section 120 has a screw case 122, a drive motor 124, a flat screw 130, a barrel 140, a first heater 150, a second heater 152, a chiller 160, a first temperature sensor 170, and a second temperature sensor 172. For convenience, the first temperature sensor 170 and the second temperature sensor 172 are not shown in FIG.

[0100] The plasticizing section 120 plasticizes the material supplied to the first groove 134 of the flat screw 130 to generate a paste-like modeling material having fluidity, and guides the same through the communication hole 146 to the injection mechanism 910.

[0101] The injection mechanism 910 has an injection cylinder 912, a plunger 914, and a plunger driver 916. The injection mechanism 910 has a function of injecting the modeling material in the injection cylinder 912 into the cavity Cv. The control unit 40 controls the injection amount of the modeling material from the nozzle 180. The injection cylinder 912 is a substantially cylindrical member connected to the communication hole 146 of the barrel 140. The plunger 914 slides inside the injection cylinder 912 and pressure-feeds the modeling material in the injection cylinder 912 to the nozzle 180 side connected to the plasticization unit 120. The plunger 914 is driven by the plunger driver 916 configured by a motor.

[0102] The mold section 920 has a movable mold 922 and a fixed mold 924. The movable mold 922 and the fixed mold 924 are provided facing each other. A cavity Cv, which is a space according to the shape of the molded product, is provided between the movable mold 922 and the fixed mold 924. A modeling material is pressure-fed to the cavity Cv by the injection mechanism 910. The nozzle 180 ejects the modeling material into the mold section 920.

[0103] The mold clamping device 930 has a mold driving part 932. The mold driving part 932 has a function of opening and closing the movable mold 922 and the fixed mold 924. The mold clamping device 930 drives the mold driving part 932 to move the movable mold 922 and open and close the mold part 920.

[0104] 4. Experimental Example The measurement value of the first temperature sensor was evaluated using a three-dimensional modeling device corresponding to the above-mentioned three-dimensional modeling device 100. Specifically, the measurement value of the first temperature sensor was evaluated when the output of the chiller was stopped, the set temperature of the second heater was maintained at 100°C, and the first heater was driven (first heater ON) and when the output of the first heater was stopped (first heater OFF). The first heater and the first temperature sensor were placed in the outer region of the barrel. The second heater was placed in the inner region of the barrel. A thermocouple was used as the first temperature sensor. MIM was used as the material.

[0105] Fig. 8 is a graph showing the relationship between measurement time and the measured value of the first temperature sensor. The measurement time was set to zero when the chiller output was stopped. When the chiller was running, the measured value of the first temperature sensor was around 70°C, but in this experimental example, the chiller was stopped, so as time passed, the measured value of the first temperature sensor increased, as shown in Fig. 8.

[0106] When the first heater was driven, a backflow of the modeling material occurred in the flat screw just before the temperature reached 80°C, and the material was completely melted. On the other hand, when the output of the first heater was stopped, the measured value of the first temperature sensor increased more slowly than when the first heater was driven. This experimental example showed that the transition to a state in which the material is completely melted can be delayed by stopping the output of the first heater.

[0107] The above-described embodiment and modifications are merely examples, and the present invention is not limited to these. For example, the embodiments and modifications can be appropriately combined.

[0108] The present invention includes configurations that are substantially the same as the configurations described in the embodiments, for example, configurations with the same functions, methods, and results, or configurations with the same purpose and effects. The present invention also includes configurations in which non-essential parts of the configurations described in the embodiments are replaced. The present invention also includes configurations that achieve the same effects as the configurations described in the embodiments, or configurations that can achieve the same purpose. The present invention also includes configurations in which publicly known technology is added to the configurations described in the embodiments.

[0109] The following can be derived from the above-described embodiment.

[0110] One aspect of the three-dimensional printing apparatus includes: A plasticizing unit that plasticizes the material to generate a modeling material; A nozzle having a nozzle opening and discharging the modeling material; a stage on which the modeling material discharged from the nozzle is laminated; and A control unit that controls the plasticizing unit; Including, The plasticizing section includes: A drive motor; a screw that is rotated by the drive motor and has a groove forming surface on which grooves are formed; a barrel having a surface facing the groove forming surface and having a communication hole; a first heater for heating the material supplied between the screw and the barrel; The control unit satisfies at least one of a first condition, a second condition, and a third condition. In this case, a process of reducing the output of the first heater is performed. however, the first condition being that a measurement value of a first temperature sensor measuring a temperature of the screw or the barrel is greater than a first predetermined value; the second condition is that the torque value of the driving motor is smaller than a second predetermined value; The third condition is that a measurement value of a pressure sensor that measures the pressure in the flow passage from the communication hole to the nozzle orifice is smaller than a third predetermined value.

[0111] According to this three-dimensional modeling device, the temperature between the flat screw and the barrel can be lowered. This makes it possible to prevent all of the material supplied between the flat screw and the barrel from melting. As a result, it is possible to prevent the bridging phenomenon and achieve stable plasticization.

[0112] In one embodiment of the three-dimensional printing apparatus, The control unit may stop the output of the first heater in the process of reducing the output of the first heater.

[0113] According to this three-dimensional modeling apparatus, the temperature between the flat screw and the barrel can be further reduced.

[0114] In one embodiment of the three-dimensional printing apparatus, The plasticizing section may include a second heater disposed closer to the communication hole than the first heater.

[0115] According to this three-dimensional modeling apparatus, even if the output of the first heater is reduced, the second heater can keep the temperature in the vicinity of the communication hole high.

[0116] In one embodiment of the three-dimensional printing apparatus, The control unit may perform a process of stopping the output of the second heater when at least one of a fourth condition, a fifth condition, and a sixth condition is satisfied after performing a process of reducing the output of the first heater. however, the fourth condition is that the measurement value of the first temperature sensor is greater than a fourth predetermined value; the fourth predetermined value is greater than the first predetermined value, the fifth condition is that the torque value of the driving motor is smaller than a fifth predetermined value; the fifth predetermined value is smaller than the second predetermined value, the sixth condition is that the measurement value of the pressure sensor is smaller than a sixth predetermined value; The sixth predetermined value is smaller than the third predetermined value.

[0117] According to this three-dimensional modeling apparatus, the temperature between the flat screw and the barrel can be further reduced.

[0118] In one embodiment of the three-dimensional printing apparatus, The control unit may perform a process of stopping output of the drive motor and generating an error signal when at least one of the fourth condition, the fifth condition, and the sixth condition is satisfied.

[0119] According to this three-dimensional modeling apparatus, it is possible to reduce the amount of material wasted while notifying the user that an error has occurred.

[0120] In one embodiment of the three-dimensional printing apparatus, The first heater and the second heater may have a shape surrounding the communication hole.

[0121] This three-dimensional modeling apparatus can easily form a temperature gradient in which the temperature gradually increases from the outer periphery of the barrel toward the communication hole.

[0122] In one embodiment of the three-dimensional printing apparatus, The first temperature sensor may measure the temperature of an outer region closer to an outer periphery of the barrel than the communication hole.

[0123] According to this three-dimensional modeling apparatus, by monitoring the temperature measured by the first temperature sensor, it is possible to prevent the material from melting in the outer region of the barrel.

[0124] In one embodiment of the three-dimensional printing apparatus, the plasticizing section has a second temperature sensor that measures the temperature of an inner region of the barrel that is closer to the communicating hole than the outer periphery of the barrel; The control unit is controlling the first heater based on a measurement value of the first temperature sensor; The second heater may be controlled based on a measurement value of the second temperature sensor.

[0125] In this three-dimensional modeling apparatus, the control unit can control the first heater and the second heater independently.

[0126] In one embodiment of the three-dimensional printing apparatus, the first temperature sensor is provided outside the first heater, The second temperature sensor may be provided inside the second heater.

[0127] According to this three-dimensional modeling apparatus, it is possible to reduce the influence of the second heater on the first temperature sensor, and the influence of the first heater on the second temperature sensor.

[0128] In one embodiment of the three-dimensional printing apparatus, The first predetermined value, the second predetermined value, and the third predetermined value may vary depending on the type of the material.

[0129] According to this three-dimensional modeling apparatus, optimal values ​​for each material can be set as the first predetermined value, the second predetermined value, and the third predetermined value.

[0130] One embodiment of the injection molding apparatus comprises: A plasticizing unit that plasticizes the material to generate a modeling material; a nozzle having a nozzle opening and configured to inject the molding material supplied from the plasticizing unit into a mold; A control unit that controls the plasticizing unit; Including, The plasticizing section includes: A drive motor; a screw that is rotated by the drive motor and has a groove forming surface on which grooves are formed; a barrel having a surface facing the groove forming surface and having a communication hole; a first heater for heating the material supplied between the screw and the barrel; The control unit performs a process of reducing an output of the first heater when at least one of a first condition, a second condition, and a third condition is satisfied. however, the first condition being that a measurement value of a first temperature sensor measuring a temperature of the screw or the barrel is greater than a first predetermined value; the second condition is that the torque value of the driving motor is smaller than a second predetermined value; The third condition is that a measurement value of a pressure sensor that measures the pressure in the flow passage from the communication hole to the nozzle orifice is smaller than a third predetermined value. [Explanation of symbols]

[0131] 10...modeling unit, 20...stage, 22...modeling surface, 30...movement mechanism, 32...motor, 40...control unit, 100...three-dimensional modeling device, 110...material input section, 112...supply path, 120...plasticization section, 122...screw case, 124...driving motor, 126...shaft, 130...flat screw, 131...upper surface, 132...groove forming surface, 133...side, 134...first groove, 135...center, 136...groove connection section, 137...material introduction section, 140...barrel, 140a...outer region, 140b...inner region, 142...opposing surface, 144...second groove, 146...communicating hole, 148...periphery , 150...first heater, 151...rod heater, 152...second heater, 153...rod heater, 160...chiller, 162...cooling channel, 164...inlet, 166...outlet, 170...first temperature sensor, 172...second temperature sensor, 180...nozzle, 182...nozzle channel, 184...nozzle hole, 190...pressure sensor, 200...three-dimensional modeling device, 900...injection molding device, 910...injection mechanism, 912...injection cylinder, 914...plunger, 916...plunger drive unit, 920...mold unit, 922...movable mold, 924...fixed mold, 930...mold clamping device, 932...mold drive unit

Claims

1. a plasticizing unit that plasticizes the material to generate a modeling material; A nozzle having a nozzle opening and discharging the modeling material; a stage on which the modeling material discharged from the nozzle is laminated; and A control unit that controls the plasticizing unit; Including, The plasticizing section includes: A drive motor; a screw that is rotated by the drive motor and has a groove forming surface on which grooves are formed; a barrel having a surface facing the groove forming surface and having a communication hole; a first heater for heating the material supplied between the screw and the barrel; a second heater provided closer to the communication hole than the first heater; having The control unit is a process of reducing an output of the first heater when at least one of a first condition, a second condition, and a third condition is satisfied; a process of stopping the output of the second heater when at least one of a fourth condition, a fifth condition, and a sixth condition is satisfied after performing the process of reducing the output of the first heater; This is a three-dimensional printing device that performs the above steps. however, the first condition is that a measurement value of a first temperature sensor that measures a temperature of the screw or the barrel is greater than a first predetermined value; the second condition is that a torque value of the driving motor is smaller than a second predetermined value; the third condition is that a measurement value of a pressure sensor that measures a pressure in a flow passage from the communication hole to the nozzle opening is smaller than a third predetermined value, the fourth condition is that the measurement value of the first temperature sensor is greater than a fourth predetermined value; The fourth predetermined value is greater than the first predetermined value, the fifth condition is that a torque value of the driving motor is smaller than a fifth predetermined value; the fifth predetermined value is smaller than the second predetermined value, the sixth condition is that the measurement value of the pressure sensor is smaller than a sixth predetermined value; The sixth predetermined value is smaller than the third predetermined value.

2. A plasticizing unit that plasticizes the material to generate a modeling material; A nozzle having a nozzle opening and discharging the modeling material; a stage on which the modeling material discharged from the nozzle is laminated; and A control unit that controls the plasticizing unit; Including, The plasticizing section includes: A drive motor; a screw that is rotated by the drive motor and has a groove forming surface on which grooves are formed; a barrel having a surface facing the groove forming surface and having a communication hole; a first heater for heating the material supplied between the screw and the barrel; a second heater provided closer to the communication hole than the first heater; having the control unit performs a process of reducing an output of the first heater when at least one of a first condition, a second condition, and a third condition is satisfied; the first heater and the second heater have a shape surrounding the communication hole. however, the first condition is that a measurement value of a first temperature sensor that measures a temperature of the screw or the barrel is greater than a first predetermined value; the second condition is that a torque value of the driving motor is smaller than a second predetermined value; The third condition is that a measurement value of a pressure sensor that measures the pressure in the flow passage from the communication hole to the nozzle opening is smaller than a third predetermined value.

3. A plasticizing unit that plasticizes the material to generate a modeling material; A nozzle having a nozzle opening and discharging the modeling material; a stage on which the modeling material discharged from the nozzle is laminated; and A control unit that controls the plasticizing unit; Including, The plasticizing section includes: A drive motor; a screw that is rotated by the drive motor and has a groove forming surface on which grooves are formed; a barrel having a surface facing the groove forming surface and having a communication hole; a first heater for heating the material supplied between the screw and the barrel; a second heater provided closer to the communication hole than the first heater; a first temperature sensor for measuring a temperature of the screw or the barrel; a second temperature sensor for measuring a temperature of an inner region of the barrel that is closer to the communication hole than an outer periphery of the barrel; having the control unit performs a process of reducing an output of the first heater when at least one of a first condition, a second condition, and a third condition is satisfied; the first temperature sensor measures a temperature of an outer region closer to an outer periphery of the barrel than the communication hole; The control unit is controlling the first heater based on a measurement value of the first temperature sensor; The three-dimensional printing apparatus controls the second heater based on a measurement value of the second temperature sensor. however, the first condition is that a measurement value of the first temperature sensor is greater than a first predetermined value; the second condition is that a torque value of the driving motor is smaller than a second predetermined value; The third condition is that a measurement value of a pressure sensor that measures the pressure in the flow passage from the communication hole to the nozzle opening is smaller than a third predetermined value.

4. In any one of claims 1 to 3, The control unit stops output of the first heater in the process of reducing the output of the first heater.

5. In claim 1, The control unit, when at least one of the fourth condition, the fifth condition, and the sixth condition is satisfied, stops output of the drive motor and generates an error signal.

6. In claim 3, the first temperature sensor is provided outside the first heater, The second temperature sensor is provided inside the second heater.

7. In any one of claims 1 to 6, The first predetermined value, the second predetermined value, and the third predetermined value differ depending on a type of the material.

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