Plasticizing equipment, 3D modeling equipment and injection molding equipment

Abstract

To provide a plasticizing device that suppresses a bridging phenomenon of resin pellets.SOLUTION: A plasticizing device 21 with a feed port 12a includes: a material storage unit 12 for storing a resin pellet 18 in pellet form; a plasticizing unit 14 having a supply port 14a connected to the feed port 12a and plasticizing at least a portion of the resin pellet 18 to produce a molding material 19; a connection pipe 13 with a connection path 13a connecting the feed port 12a and the supply port 14a; a first material sensor 23 for detecting a remaining amount of the resin pellet 18 in the connection path 13a; and a control unit 7. The material storage unit 12 has a material supply mechanism 17 that supplies the resin pellet 18 to the connection path 13a. When the remaining amount of the resin pellet 18 detected by the first material sensor 23 is less than a first standard value, the control unit 7 operates the material supply mechanism 17 to supply a predetermined amount of the resin pellet 18 to the connection path 13a.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] A plasticizing device that plasticizes resin pellets is used in three-dimensional modeling devices and injection molding devices that mold structures using resin pellets, which are pellet-shaped resin materials. The plasticizing device disclosed in Patent Document 1 is of the flat screw type. The plasticizing device includes a rotor with a spiral groove formed therein, and a barrel that abuts against the end face of the rotor and has a communication hole in the center. The rotor and barrel are disposed opposite each other. The rotor is rotated by a motor. A heater is disposed within the barrel, and the resin pellets are heated in the spiral groove to plasticize them.

[0003] The resin pellets used as the raw material are stored in a hopper, from which they are fed to the entrance of a spiral groove on the side of the rotor. [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 device of Patent Document 1, the weight of the resin pellets themselves causes the resin pellets to interfere with each other and become clogged before they are supplied to the rotor, resulting in a bridge phenomenon. When the bridge phenomenon occurs, the resin pellets are not properly supplied to the rotor. The present application aims to suppress the bridge phenomenon. [Means for solving the problem]

[0006] The plasticization device comprises a material storage section having an inlet and storing pellet-shaped plasticized material, a plasticization section having a supply port connected to the inlet and plasticizing at least a portion of the plasticized material to produce a modeling material, a connecting pipe having a connection path connecting the inlet and the supply port, a first material sensor that detects the remaining amount of the plasticized material in the connection path, and a control section, wherein the material storage section has a material supply mechanism that supplies the plasticized material to the connection path, and when the remaining amount detected by the first material sensor is less than a first reference value, the control section operates the material supply mechanism to supply a predetermined amount of the plasticized material to the connection path.

[0007] The three-dimensional modeling apparatus includes the plasticizing device described above, a stage having a modeling surface, and a nozzle that ejects the modeling material supplied from the plasticizing device toward the modeling surface.

[0008] The injection molding apparatus includes the plasticizing device described above and a nozzle that injects the molding material supplied from the plasticizing device toward a mold. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram showing a configuration of a three-dimensional printing apparatus according to a first embodiment. [Diagram 2] FIG. 4 is a schematic cross-sectional side view of a main portion for explaining the structure of a material supply mechanism. [Diagram 3] FIG. 4 is a schematic cross-sectional plan view of a main portion for explaining the structure of a material supply mechanism. [Figure 4] FIG. 4 is a schematic cross-sectional side view of a main portion for explaining the structure of a material supply mechanism. [Diagram 5] FIG. 4 is a schematic cross-sectional view of a main portion for explaining the structure of a material supply mechanism. [Figure 6] FIG. 4 is a schematic cross-sectional side view of a main portion for explaining the structure of a connecting pipe. [Figure 7] FIG. 4 is a schematic cross-sectional side view of a main portion for explaining the structure of a connecting pipe. [Figure 8] FIG. 4 is a schematic cross-sectional side view showing the configuration of a plasticizing section. [Figure 9]FIG. 4 is a schematic perspective view showing the configuration of a groove forming surface side of a flat screw. [Figure 10] FIG. 4 is a schematic plan view showing the configuration of the opposing surface side of the barrel facing the flat screw. [Figure 11] FIG. 6 is a schematic diagram showing the configuration of an injection molding apparatus according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] First embodiment In this embodiment, a characteristic example of a three-dimensional modeling apparatus equipped with a plasticizing device will be described with reference to the drawings. In Fig. 1, arrows are shown along the X, Y, and Z directions that are perpendicular to each other. The X and Y directions are directions along the horizontal direction, and the Z direction is a direction along the vertical direction. The direction of gravity is the negative Z direction.

[0011] As shown in Fig. 1, a three-dimensional modeling apparatus 1 has a base 2. An XY table 3 serving as a moving section is placed on the base 2. A Y table 4 and an X table 5 are placed on the XY table 3, stacked in this order in the Z positive direction. A stage 6 is placed on top of the XY table 3.

[0012] The Y-table 4 is equipped with a Y-axis motor 4a, a ball screw, a Y-axis scale, etc. The Y-table 4 moves the stage 6 back and forth in the Y direction. The X-table 5 is equipped with an X-axis motor 5a, a ball screw, an X-axis scale, etc. The X-table 5 moves the stage 6 back and forth in the X direction.

[0013] The three-dimensional modeling apparatus 1 is equipped with a control unit 7. The control unit 7 controls the movement of the Y table 4 and the X table 5. The control unit 7 recognizes the position of the stage 6 in the Y direction from information output by the Y-axis scale. The control unit 7 recognizes the position of the stage 6 in the X direction from information output by the X-axis scale. The control unit 7 moves the Y table 4 and the X table 5 so that there is no difference between the target position to which the stage 6 should be moved and the current position. The control unit 7 controls the trajectory of the movement of the stage 6 by sequentially changing the target position to which the stage 6 should be moved.

[0014] A lifting table 8 serving as a moving part is installed on the negative X direction side of the base 2. The lifting table 8 has a fixed table 8a, which stands on the base 2. A rail 8b is installed on the surface of the fixed table 8a on the positive X direction side. A moving table 8c is installed on the positive X direction side of the rail 8b. The moving table 8c moves back and forth in the Z direction along the rail 8b.

[0015] A Z-axis motor 8d is installed on the Z positive direction side of the fixed table 8a. The fixed table 8a is equipped with a ball screw and a Z-axis scale inside. As with the Y table 4 and the X table 5, the control unit 7 controls the trajectory of the moving table 8c. The moving unit includes the XY table 3 and the lift table 8.

[0016] A unit support part 9 is installed on the X positive direction side of the moving table 8c. A modeling unit 11 is installed on the X positive direction side of the unit support part 9, and the unit support part 9 supports the modeling unit 11. In the modeling unit 11, a material storage part 12, a connection pipe 13, a plasticization part 14, and a discharge part 15 are installed in this order toward the Z negative direction.

[0017] The material storage section 12 includes a container 16 having a cavity therein and a material supply mechanism 17. Resin pellets 18 are stored inside the container 16 as a pellet-shaped plasticizing material. The resin pellets 18 are lumps of resin. The size of the resin pellets 18 is not particularly limited, but in this embodiment, for example, it is within a range of 5 mm to 20 mm. The material storage section 12 includes an inlet 12a in the material supply mechanism 17. The connection pipe 13 includes a connection path 13a inside. The material supply mechanism 17 supplies the resin pellets 18 to the connection path 13a. The container 16 includes a third window 16b and a fourth window 16c. The third window 16b and the fourth window 16c are formed of a transparent material such as glass. The third window 16b is disposed on the Z positive side of the container 16. The fourth window 16c is disposed on the Z negative side of the container 16. The remaining amount of the resin pellets 18 in the container 16 is observed through the third window 16b and the fourth window 16c.

[0018] The connecting pipe 13 is connected to the inlet 12a of the material storage section 12. The resin pellets 18 move from inside the material storage section 12 into the connecting pipe 13 due to their own weight. The connecting pipe 13 is connected to the plasticizing section 14. The plasticizing section 14 has a supply port 14a that communicates with the inlet 12a. The connecting path 13a connects the inlet 12a and the supply port 14a. The resin pellets 18 are supplied from the connecting pipe 13 to the plasticizing section 14. The resin pellets 18 may contain other materials such as metals and ceramics in addition to thermoplastic materials. In addition, when metal powder is contained in the resin pellets, not all of the resin pellets are plasticized in the plasticizing section, so at least a portion of the resin pellets are plasticized in the plasticizing section.

[0019] The plasticizing unit 14 plasticizes at least a portion of the resin pellets 18. "Plasticization" is a concept that includes melting, and refers to changing from a solid to a fluid state. Specifically, in the case of a material that undergoes glass transition, plasticization refers to raising the temperature of the material to or above the glass transition point. In the case of a material that does not undergo glass transition, plasticization refers to raising the temperature of the material to or above the melting point. The plasticizing unit 14 plasticizes the resin pellets 18 to generate the molding material 19. The material storage unit 12, the connecting pipe 13, the plasticizing unit 14, the control unit 7, etc. constitute a plasticizing device 21.

[0020] The plasticization unit 14 is connected to the discharge unit 15. The discharge unit 15 is equipped with a nozzle 22. The surface of the stage 6 facing the nozzle 22 is the modeling surface 6a. The stage 6 has the modeling surface 6a. The nozzle 22 discharges the modeling material 19 supplied from the plasticization device 21 toward the modeling surface 6a. The modeling surface 6a of the stage 6 receives the modeling material 19 discharged from the nozzle 22. While the nozzle 22 is discharging the modeling material 19, the control unit 7 drives the XY table 3 to move the stage 6 in the X and Y directions. As a result, the three-dimensional modeling device 1 forms a figure of a predetermined pattern on the stage 6. This figure is the first stage figure.

[0021] Next, the lift table 8 moves the modeling unit 11 a predetermined distance in the positive Z direction. The 3D modeling device 1 forms a figure in the second stage by overlapping it on the figure in the first stage. Furthermore, the 3D modeling device 1 forms a three-dimensional structure 20 by successively overlapping and forming figures in the third stage and thereafter.

[0022] The plasticizing section 14 of the plasticizing device 21 is disposed below the material storage section 12 in the direction of gravity. The lifting table 8 moves the plasticizing section 14 and the material storage section 12 relative to the stage 6. The lifting table 8 moves the material storage section 12 in conjunction with the movement of the plasticizing section 14.

[0023] According to this configuration, the plasticizing section 14 and the material storage section 12 are linked, so the connecting pipe 13 does not need to be deformed when the plasticizing section 14 and the material storage section 12 move. Therefore, the connecting pipe 13 can be made shorter than when the connecting pipe 13 is deformed.

[0024] The XY table 3 moves the modeling surface 6a in a direction along the modeling surface 6a. The lift table 8 moves the plasticizing unit 14 and the material storage unit 12 in a direction perpendicular to the modeling surface 6a.

[0025] According to this configuration, the plasticizing section 14 and the material storage section 12 move in the direction of gravity and in the direction opposite to the direction of gravity. Since the plasticizing section 14 and the material storage section 12 have large inertia, they can be moved faster than when they are moved along a plane perpendicular to the direction of the gravitational acceleration.

[0026] A first material sensor 23 and a second material sensor 24 are installed on the plasticizing section 14 side of the connection path 13a. The first material sensor 23 and the second material sensor 24 detect the remaining amount of resin pellets 18 in the connection path 13a. The second material sensor 24 is disposed between the first material sensor 23 and the input port 12a. The method by which the first material sensor 23 and the second material sensor 24 detect the resin pellets 18 is not particularly limited, but in this embodiment, for example, an optical method is adopted.

[0027] The plasticizing device 21 is provided with an air blowing section 25 between the material storage section 12 and the plasticizing section 14. The air blowing section 25 is installed on the unit support section 9. The air blowing section 25 rises and falls in conjunction with the plasticizing section 14 and the connecting pipe 13. The air blowing section 25 is provided with a blower fan 26 and an air blowing nozzle 27. The air blower fan 26 causes air to flow and blows air to the air blowing nozzle 27. The air blowing nozzle 27 is installed facing the first material sensor 23. The air blowing section 25 blows air from the air blowing nozzle 27 towards the first material sensor 23.

[0028] According to this configuration, it is possible to blow away the powdered resin pellets 18 and dust adhering to the first material sensor 23. In addition, it is possible to suppress a decrease in the sensitivity of the first material sensor 23.

[0029] The blower 25 may include a blower nozzle 27 that blows air toward the second material sensor 24. This can blow away the powdered resin pellets 18 and dust adhering to the second material sensor 24. This can prevent the sensitivity of the second material sensor 24 from decreasing.

[0030] The blower fan 26 includes an ionizer 28 therein. The ionizer 28 generates gas having a positive or negative charge. It is possible to set whether the gas is positively or negatively charged. The ionizer 28 can also generate positive and negative charges alternately. The blower unit 25 blows the gas having a charge. With this configuration, when the powdered resin pellets 18 or dust adheres to the first material sensor 23 due to static electricity, it is possible to easily remove the powdered resin pellets 18 and dust by de-electrifying them.

[0031] Next, the structure of the material supply mechanism 17 will be described with reference to Figures 2 to 5. Figure 3 is a view taken along line AA in Figure 2. Figure 5 is a view taken along line AA in Figure 4. As shown in Figures 2 and 3, the material supply mechanism 17 includes a guide case 29. The inside of the guide case 29 is hollow. The guide case 29 includes a material inlet 16a on the container 16 side. The guide case 29 includes an input port 12a on the connecting pipe 13 side.

[0032] The guide case 29 has a material cutting plate 31 therein as a sliding member. The material cutting plate 31 slides and reciprocates in the X direction inside the guide case 29. The material cutting plate 31 has a cutting hole 31a as a hole. An air cylinder 32 as a slide drive unit is installed on the Z negative direction side of the guide case 29. The air cylinder 32 has a piston rod 32a therein. The piston rod 32a reciprocates in the X direction. One end of the piston rod 32a is fixed to the material cutting plate 31. The material cutting plate 31 works in conjunction with the piston rod 32a.

[0033] The air cylinder 32 has a first air pressure port 32b on the X negative side. The air cylinder 32 has a second air pressure port 32c on the X positive side. When compressed air is supplied to the first air pressure port 32b, the piston rod 32a and the material cutting plate 31 move in the X positive direction. When compressed air is supplied to the second air pressure port 32c, the piston rod 32a and the material cutting plate 31 move in the X negative direction.

[0034] The control unit 7 is equipped with a solenoid valve. A pipe for supplying compressed air is connected to the solenoid valve. The solenoid valve is connected to the first air pressure port 32b and the second air pressure port 32c by pipes (not shown). The control unit 7 controls the solenoid valve to supply compressed air to one of the first air pressure port 32b and the second air pressure port 32c. In this manner, the control unit 7 controls the moving direction of the material cutting plate 31.

[0035] The material supply mechanism 17 has a material cutting plate 31 having a cutting hole 31a, and an air cylinder 32 that slides the material cutting plate 31. The air cylinder 32 drives the material cutting plate 31.

[0036] A magnet piece 32d is installed on the piston rod 32a. The air cylinder 32 is provided with a first cylinder sensor 32e as a third sensor on the first air pressure port 32b side. The air cylinder 32 is provided with a second cylinder sensor 32f as a third sensor on the second air pressure port 32c side. When the material cutting plate 31 moves in the negative X direction, the first cylinder sensor 32e detects the magnet piece 32d. When the material cutting plate 31 moves in the positive X direction, the second cylinder sensor 32f detects the magnet piece 32d. Therefore, the first cylinder sensor 32e and the second cylinder sensor 32f detect whether the material cutting plate 31 is located in the negative X direction, the positive X direction, or at the midpoint.

[0037] The state in which the material feeding plate 31 is positioned in the X positive direction is defined as the second state. In Fig. 3, the material feeding plate 31 is hatched with dashed lines. When viewed from the Z direction, in the second state, the feeding hole 31a and the feeding port 12a overlap. Some of the resin pellets 18 in the feeding hole 31a are fed into the connecting pipe 13. That is, in the second state, the resin pellets 18 in the material storage section 12 are fed into the connecting pipe 13.

[0038] The side surface of the cut-out hole 31a on the negative X-direction side is an inclined surface 31g. The angle between the inclined surface 31g and the X-direction is preferably 25 degrees or more and 35 degrees or less. This angle is called the angle of repose, and is an angle at which the resin pellets 18 do not slide on the inclined surface 31g. When the angle of the inclined surface 31g is the angle of repose, the resin pellets 18 stay in the cut-out hole 31a, so the resin pellets 18 do not flow continuously from the material inlet 16a to the input port 12a. Furthermore, clogging of the resin pellets 18 between the material inlet 16a and the inclined surface 31g can be suppressed.

[0039] As shown in Figures 4 and 5, compressed air is supplied to the air cylinder 32 from the second air pressure port 32c. The piston rod 32a moves in the X negative direction. The air cylinder 32 drives the material cutting plate 31, and the material cutting plate 31 moves in the X negative direction. The state in which the material cutting plate 31 is located in the X negative direction is defined as the first state. In Figure 5, the material cutting plate 31 is hatched with a broken line. In the first state, when viewed from the Z direction, the cutting hole 31a and the feed port 12a do not overlap. Therefore, in the first state, the resin pellets 18 in the material storage section 12 are not fed into the connecting pipe 13.

[0040] In the first state as viewed from the Z direction, the area where the material inlet 16a and the cutting hole 31a overlap is larger than in the second state. After the resin pellets 18 are discharged, the resin pellets 18 are fed from the material inlet 16a into the hollow portion of the cutting hole 31a. The control unit 7 drives the air cylinder 32 to switch between the first state and the second state. When the material cutting plate 31 makes one reciprocating motion, a predetermined amount of resin pellets 18 is fed from the feed port 12a into the connecting path 13a. The control unit 7 controls the number of times the material cutting plate 31 makes a reciprocating motion, thereby controlling the amount of resin pellets 18 fed into the connecting path 13a.

[0041] According to this configuration, in the first state, the resin pellets 18 are fed into the extrusion hole 31a. In the second state, the resin pellets 18 are fed from the extrusion hole 31a into the connection path 13a of the connection pipe 13. Therefore, the material supply mechanism 17 can be configured with a simple configuration using the air cylinder 32 or the like.

[0042] When the material dispensing plate 31 moves in the negative X direction, the magnet piece 32d approaches the first cylinder sensor 32e. The first cylinder sensor 32e detects the magnet piece 32d. Therefore, the first cylinder sensor 32e detects that the material dispensing plate 31 is located in the negative X direction.

[0043] The material supply mechanism 17 has a first cylinder sensor 32e and a second cylinder sensor 32f that detect the biting of the resin pellets 18 in the material feed plate 31. When the material feed plate 31 moves in the negative X direction, the resin pellets 18 are pinched between the side of the feed hole 31a and the side of the feed port 12a. When the biting occurs, the first cylinder sensor 32e does not detect the magnet piece 32d. When the first cylinder sensor 32e does not detect the magnet piece 32d, the control unit 7 determines that the biting has occurred. Then, the control unit 7 drives the air cylinder 32 to slide the material feed plate 31 back and forth. In this way, when the first cylinder sensor 32e detects the biting of the resin pellets 18, the air cylinder 32 performs a return operation to slide the material feed plate 31.

[0044] When the material feed plate 31 moves in the X-positive direction, the resin pellets 18 are caught between the side of the feed hole 31a and the side of the material inlet 16a. When this kind of jamming occurs, the second cylinder sensor 32f does not detect the magnet piece 32d. When the second cylinder sensor 32f does not detect the magnet piece 32d even after a predetermined time has elapsed, the control unit 7 determines that jamming has occurred. Then, the control unit 7 drives the air cylinder 32 to slide the material feed plate 31 back and forth. In this way, when the second cylinder sensor 32f detects jamming of the resin pellets 18, the air cylinder 32 performs a return operation to slide the material feed plate 31.

[0045] According to this configuration, the first cylinder sensor 32e and the second cylinder sensor 32f detect the jamming of the resin pellets 18. Then, the air cylinder 32 slides the material cutting plate 31 back and forth to remove the jammed resin pellets 18. Therefore, the jammed resin pellets 18 can be removed without the intervention of an operator.

[0046] As shown in Fig. 6, in the first material sensor 23, the first light emitter 23a and the first light receiver 23b are arranged facing each other in the Y direction. When the resin pellets 18 in the connecting pipe 13 decrease, the resin pellets 18 disappear from between the first light emitter 23a and the first light receiver 23b, and the first light receiver 23b detects the light emitted by the first light emitter 23a. At this time, the remaining amount of the resin pellets 18 present inside the connecting pipe 13 is the first reference value. The first material sensor 23 detects that the remaining amount of the resin pellets 18 is less than the first reference value.

[0047] When the remaining amount of the resin pellets 18 detected by the first material sensor 23 is less than a first reference value, the control unit 7 operates the material supply mechanism 17 to supply a predetermined amount of the resin pellets 18 to the connection path 13a.

[0048] According to this configuration, resin pellets 18 are stored in the material storage section 12. A connecting pipe 13 is connected to the material storage section 12. A material supply mechanism 17 of the material storage section 12 supplies the resin pellets 18 to the connecting pipe 13. When the material supply mechanism 17 is not operating, the resin pellets 18 are not supplied to the connecting pipe 13. The resin pellets 18 accumulate in the connection path 13a of the connecting pipe 13. When the resin pellets 18 move to the plasticizing section 14, the amount of resin pellets 18 in the connection path 13a decreases. Resin pellets 18 that have not been used in the plasticizing section 14 are left in the connection path 13a of the connecting pipe 13. A first material sensor 23 detects the remaining amount of resin pellets 18 left in the connection path 13a.

[0049] When the remaining amount of resin pellets 18 in the connection path 13a is less than the first reference value, the control unit 7 drives the material supply mechanism 17 to supply a predetermined amount of resin pellets 18 to the connection path 13a of the connection pipe 13. Therefore, the amount of resin pellets 18 in the connection path 13a of the connection pipe 13 does not exceed the sum of the first reference value and the predetermined amount. The sum of the first reference value and the predetermined amount is an amount at which a bridging phenomenon does not occur. As a result, it is possible to suppress the occurrence of the bridging phenomenon in which resin pellets 18 interfere with each other and become clogged due to the weight of the resin pellets 18 themselves.

[0050] The connecting pipe 13 has a first window 33 as a transparent member and a second window 34 as a transparent member. The first window 33 and the second window 34 are made of a transparent member such as glass. Therefore, the state inside the connecting pipe 13 can be seen. In this manner, at least a portion of the connecting pipe 13 is made of a transparent member. With this configuration, the operator can check the remaining amount of resin pellets 18 held in the connection path 13a.

[0051] As shown in FIG. 7, the second material sensor 24 is disposed between the first material sensor 23 and the inlet 12a. The second material sensor 24 is disposed such that the second light emitter 24a and the second light receiver 24b face each other in the Y direction. The material supply mechanism 17 supplies the resin pellets 18 to the connection path 13a, and the resin pellets 18 gradually increase in the connection path 13a. When there are no resin pellets 18 between the second light emitter 24a and the second light receiver 24b, the second light receiver 24b detects the light emitted by the second light emitter 24a. When there are resin pellets 18 between the second light emitter 24a and the second light receiver 24b, the second light receiver 24b does not detect the light emitted by the second light emitter 24a. When the resin pellets 18 are supplied up to the second material sensor 24, the remaining amount of the resin pellets 18 present inside the connection pipe 13 is the second reference value. The second material sensor 24 detects that the remaining amount of the resin pellets 18 has reached the second reference value.

[0052] In the first material sensor 23, when the first light receiving portion 23b detects the light emitted by the first light emitting portion 23a, the control portion 7 receives a signal output by the first material sensor 23 and determines that the remaining amount of resin pellets 18 has decreased below the first reference value. At this time, the resin pellets 18 have not reached the second material sensor 24. In the second material sensor 24, the second light receiving portion 24b detects the light emitted by the second light emitting portion 24a. The control portion 7 operates the material supply mechanism 17 to supply the resin pellets 18 to the connection path 13a.

[0053] When the second light receiving portion 24b of the second material sensor 24 does not detect the light emitted by the second light emitting portion 24a, the control portion 7 receives the signal output by the second material sensor 24 and determines that the remaining amount of the resin pellets 18 has reached the second reference value. The control portion 7 stops the operation of the material supply mechanism 17 and stops the supply of the resin pellets 18 to the connection path 13a.

[0054] In this way, when the remaining amount of the resin pellets 18 detected by the first material sensor 23 is less than the first reference value, the material supply mechanism 17 supplies the resin pellets 18 until the remaining amount reaches the second reference value detected by the second material sensor 24.

[0055] In detail, the control unit 7 receives a signal from the first material sensor 23 indicating that the remaining amount of resin pellets 18 is less than a first reference value. Next, the control unit 7 outputs an instruction signal to the material supply mechanism 17 to supply the resin pellets 18. Next, the control unit 7 receives a signal from the second material sensor 24 indicating that the resin pellets 18 have been supplied up to the second reference value. Next, the control unit 7 outputs an instruction signal to the material supply mechanism 17 to stop supplying the resin pellets 18. In this way, the control unit 7 cooperates with the first material sensor 23, the second material sensor 24, and the material supply mechanism 17 to supply the resin pellets 18 up to the second reference value.

[0056] According to this configuration, the sum of the supply amount of resin pellets 18 supplied by the material supply mechanism 17 to the connection path 13a and the remaining amount can be set to the second reference value. The second reference value is an amount at which the bridging phenomenon does not occur. Resin pellets 18 can be fed until the sum of the supply amount and the remaining amount stored in the connection path 13a reaches the second reference value. Therefore, the supply frequency can be reduced compared to when a small amount of resin pellets 18 is supplied many times.

[0057] Even when the resin pellets 18 are present between the blowing nozzle 27 and the first material sensor 23, the blowing unit 25 may blow air toward the first material sensor 23. The air may be blown continuously or at predetermined intervals.

[0058] 8, the plasticizing unit 14 includes a screw case 35. The screw case 35 is hollow inside. A motor 36 is installed on the positive Z direction side of the screw case 35. The control unit 7 controls the rotation angle, rotation speed, and timing to start and stop rotation of the motor 36.

[0059] A reduction gear 37 is connected to the rotating shaft 36a of the motor 36. When the rotating shaft 36a rotates at high speed, the outer periphery of the reduction gear 37 rotates at a reduced speed. The outer periphery of the reduction gear 37 rotating at a slower speed becomes the output shaft 37a. A bearing 38 is installed on the outer periphery of the reduction gear 37. The bearing 38 is disposed between the screw case 35 and the reduction gear 37. The bearing 38 supports the reduction gear 37 so that it can rotate.

[0060] A screw support portion 39 is installed on the output shaft 37a of the reduction gear 37. A flat screw 41 is installed on the screw support portion 39. The flat screw 41 rotates in synchronization with the output shaft 37a. The flat screw 41 is rotated by the motor 36. A screw rotation center 41d which is the rotation center of the flat screw 41 is coaxial with a motor rotation center 36b which is the rotation center of the motor 36.

[0061] 8 and 9, the flat screw 41 has a groove forming surface 41a on which a spiral groove 41b is formed. The flat screw 41 has a generally cylindrical shape whose size in the direction of the rotation axis 36a is smaller than its size in a direction perpendicular to the direction of the rotation axis 36a. In the illustrated example, one spiral groove 41b is provided. The number of grooves 41b is not particularly limited. Although not illustrated, two or more grooves 41b may be provided.

[0062] The screw case 35 houses the reduction gear 37, the screw support 39, and the flat screw 41. The screw case 35 has a supply path 35a that connects to the connecting pipe 13. The supply path 35a continues from the connecting pipe 13 to the flat screw 41. The opening of the supply path 35a on the flat screw 41 side is a passage port 35b. The screw case 35 has the passage port 35b through which the resin pellets 18 pass toward the flat screw 41.

[0063] A barrel 42 is provided on the negative Z direction side of the flat screw 41. A barrel case 43 that houses the barrel 42 is provided on the negative Z direction side of the screw case 35. The flat screw 41 rotates relative to the barrel 42.

[0064] 8 and 10, the barrel 42 has an opposing surface 42a that faces the groove forming surface 41a. A heater 44 is installed inside the barrel 42 at a location that faces the groove 41b. The heater 44 heats the resin pellets 18 that are supplied between the groove forming surface 41a and the opposing surface 42a. The heated resin pellets 18 are plasticized to become the molding material 19. The barrel 42 is provided with a communication hole 45 through which the molding material 19 formed by plasticizing the resin pellets 18 flows.

[0065] A plurality of guide grooves 46 are formed around the communication hole 45 in the opposing surface 42a. One end of each guide groove 46 is connected to the communication hole 45, and extends in a spiral shape from the communication hole 45 toward the outer periphery of the opposing surface 42a. Each guide groove 46 guides the molding material 19 to the communication hole 45. Note that one end of the guide groove 46 does not have to be connected to the communication hole 45, and the guide groove 46 does not have to be formed in the opposing surface 42a.

[0066] The depth of the groove 41b in the flat screw 41 is shallower closer to the screw rotation center 41d than on the outer periphery. Therefore, the cross-sectional area of ​​the groove 41b is smaller closer to the screw rotation center 41d than on the outer periphery. The pressure of the modeling material 19 in the groove 41b is higher on the screw rotation center 41d side, and the modeling material 19 is pushed out to the communication hole 45. The flat screw 41 functions as a pump to move the modeling material 19.

[0067] According to this configuration, since the plasticizing section 14 is composed of the flat screw 41 and the barrel 42, it can be made smaller than a type composed of an in-line screw.

[0068] According to this configuration, the three-dimensional modeling apparatus 1 includes the above-described plasticizing device 21. The above-described plasticizing device 21 can suppress the occurrence of the bridging phenomenon. Therefore, the three-dimensional modeling apparatus 1 can supply the resin pellets 18 to the plasticizing section 14 for a long period of time.

[0069] Second embodiment This embodiment introduces an example of an injection molding apparatus equipped with the plasticizing device 21 of the first embodiment.

[0070] 11, the injection molding apparatus 50 includes a plasticizing apparatus 51, an injection control mechanism 52, a nozzle 53, a mold 54, and a mold clamping apparatus 55. The plasticizing apparatus 51 uses the plasticizing apparatus 21 of the first embodiment.

[0071] The plasticizer 51 has a flat screw 56 and a barrel 57. An injection cylinder 59 is connected to a communication hole 58 of the barrel 57. Under the control of the control unit 61, the plasticizer 51 plasticizes the resin pellets 18 supplied to the groove portion 62 of the flat screw 56, generates a paste-like molding material 19 having fluidity, and guides it from the communication hole 58 to the injection control mechanism 52.

[0072] Additionally, the plasticizer 51 includes a material storage section 69, a connecting pipe 71, and a blower section 72. The material storage section 69, the connecting pipe 71, and the blower section 72 correspond to the material storage section 12, the connecting pipe 13, and the blower section 25 of the first embodiment, respectively.

[0073] The injection control mechanism 52 includes an injection cylinder 59, a plunger 63, and a plunger driver 64. The injection control mechanism 52 injects the modeling material 19 in the injection cylinder 59 into the cavity 65. The injection control mechanism 52 controls the injection amount of the modeling material 19 injected from the nozzle 53 under the control of the control unit 61. The injection cylinder 59 is a substantially cylindrical member connected to the communication hole 58 of the barrel 57, and includes a plunger 63 therein. The plunger 63 slides inside the injection cylinder 59, and pressure-feeds the modeling material 19 in the injection cylinder 59 to the nozzle 53 connected to the plasticizer 51. The plunger 63 is driven by a plunger driver 64 configured by a motor.

[0074] The mold 54 includes a movable mold 66 and a fixed mold 67. The movable mold 66 and the fixed mold 67 are disposed facing each other, and a cavity 65, which is a space corresponding to the shape of the molded product, is formed between them. The molding material 19 pumped by the injection control mechanism 52 is injected into the cavity 65 through the nozzle 53.

[0075] The mold clamping device 55 includes a mold driving unit 68. The mold driving unit 68 opens and closes a movable mold 66 and a fixed mold 67. Under the control of the control unit 61, the mold clamping device 55 drives the mold driving unit 68 to move the movable mold 66, thereby opening and closing the movable mold 66 and the fixed mold 67.

[0076] In the injection molding device 50, the plasticizing device 21 of the first embodiment is used as the plasticizing device 51. The injection molding device 50 includes a nozzle 53 that injects the molding material 19 supplied from the plasticizing device 51 toward a mold 54.

[0077] According to this configuration, the injection molding device 50 includes the plasticizer 51 equipped with the plasticizer 21. The plasticizer 21 can suppress the bridge phenomenon of the resin pellets 18. Therefore, the plasticizer 51 can supply the molding material 19 to the nozzle 53 for a long period of time.

[0078] Third embodiment In the first embodiment, the XY table 3 moves the stage 6 in the X and Y directions. The lift table 8 moves the discharge unit 15 in the Z direction. Alternatively, a lift table that moves the stage 6 in the Z direction and an XY table that moves the discharge unit 15 in the X and Y directions may be provided. Alternatively, an XYZ table that does not move the stage 6 but moves the discharge unit 15 in the X, Y and Z directions may be provided. Alternatively, an XYZ table that does not move the discharge unit 15 but moves the stage 6 in the X, Y and Z directions may be provided. In either format, a three-dimensional structure 20 can be formed on the stage 6. [Explanation of symbols]

[0079] 1...three-dimensional modeling apparatus, 3...XY table as moving part, 6...stage, 6a...modeling surface, 7...control part, 8...lifting table as moving part, 12...material storage part, 12a...feeding port, 13,71...connecting pipe, 13a...connecting path, 14...plasticizing part, 14a...supply port, 17...material supply mechanism, 18...resin pellets as plasticizing material, 19...modeling material, 21,51...plasticizing device, 22,53...nozzle, 23...first material sensor, 24...second material sensor, 25,72...blower part, 31...slurry Material cutting plate as guide member, 31a...cutting hole as hole, 32...air cylinder as slide drive part, 32e...first cylinder sensor as third sensor, 32f...second cylinder sensor as third sensor, 33...first window as transparent member, 34...second window as transparent member, 36...motor, 41, 56...flat screw, 41a...groove forming surface, 41b...groove, 42, 57...barrel, 42a...opposing surface, 45...communicating hole, 50...injection molding apparatus, 54...mold.

Claims

1. A material storage section having an inlet and storing a pellet-shaped plasticizing material; a plasticizing unit having a supply port communicating with the inlet and plasticizing at least a portion of the plasticizing material to generate a modeling material; a connecting pipe having a connection path connecting the input port and the supply port; a first material sensor for detecting a remaining amount of the plasticizing material in the connection path; A control unit, the material storage section includes a slide member having a hole and a slide drive section for sliding the slide member, and has a material supply mechanism for supplying the plasticizing material to the connection path; the control unit operates the material supply mechanism to supply a predetermined amount of the plasticizing material to the connection path when the remaining amount detected by the first material sensor is less than a first reference value; The plasticizing device is characterized in that the slide driving unit drives the slide member to switch between a first state in which the plasticized material in the material storage unit is not fed into the connecting pipe, and a second state in which the plasticized material in the material storage unit is fed into the connecting pipe.

2. A material storage section having an inlet and storing a pellet-shaped plasticizing material; a plasticizing unit having a supply port communicating with the inlet and plasticizing at least a portion of the plasticizing material to generate a modeling material; a connecting pipe having a connection path connecting the input port and the supply port; a first material sensor for detecting a remaining amount of the plasticizing material in the connection path; A blower that blows air toward the first material sensor; A control unit, the material storage unit has a material supply mechanism that supplies the plasticizing material to the connection path, A plasticizing device characterized in that the control unit operates the material supply mechanism to supply a predetermined amount of the plasticizing material to the connection path when the remaining amount detected by the first material sensor is less than a first reference value.

3. A material storage section having an inlet and storing a pellet-shaped plasticizing material; a plasticizing unit having a supply port communicating with the inlet and plasticizing at least a portion of the plasticizing material to generate a modeling material; a connecting pipe having a connection path connecting the input port and the supply port; a first material sensor for detecting a remaining amount of the plasticizing material in the connection path; A control unit, the material storage unit has a material supply mechanism that supplies the plasticizing material to the connection path, the control unit operates the material supply mechanism to supply a predetermined amount of the plasticizing material to the connection path when the remaining amount detected by the first material sensor is less than a first reference value; The plasticizing unit includes a motor and a flat screw having a groove forming surface on which a spiral groove is formed and rotated by the motor; A plasticizing device comprising: a barrel having an opposing surface facing the groove forming surface and having a communicating hole through which the molding material flows.

4. A plasticizing apparatus according to any one of claims 1 to 3, a second material sensor disposed between the first material sensor and the inlet; The plasticizing device is characterized in that the control unit supplies the plasticized material up to a second reference value detected by the second material sensor when the remaining amount detected by the first material sensor is less than a first reference value.

5. 2. The plasticizing device according to claim 1, the material supply mechanism has a third sensor that detects the plasticized material being caught in the slide member, The plasticizing device is characterized in that the slide drive unit performs a return operation to slide the slide member when the third sensor detects that the plasticizing material is caught.

6. 3. The plasticizing device according to claim 2, The plasticizing device, wherein the blowing section blows gas having an electric charge.

7. A plasticizing device according to any one of claims 1 to 6, A plasticizing device, wherein at least a portion of the connecting pipe is made of a transparent material.

8. A plasticizing device according to any one of claims 1 to 7, A stage having a modeling surface; a nozzle that ejects the modeling material supplied from the plasticizer toward the modeling surface; A three-dimensional printing apparatus comprising:

9. The three-dimensional modeling apparatus according to claim 8, The plasticizing section of the plasticizing device is disposed below the material storage section in a gravitational direction, a moving unit that moves the plasticizing unit and the material storage unit relative to the stage, The three-dimensional modeling apparatus, wherein the moving unit moves the material storage unit in conjunction with the movement of the plasticizing unit.

10. The three-dimensional modeling apparatus according to claim 9, A three-dimensional printing device characterized in that the moving unit moves the printing surface in a direction along the printing surface, and the moving unit moves the plasticization unit and the material storage unit in a direction perpendicular to the printing surface.

11. A plasticizing device according to any one of claims 1 to 7, A nozzle that injects the molding material supplied from the plasticizer toward a mold; An injection molding apparatus comprising:

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