Material feeding device, 3D modeling device, and injection molding device

Abstract

To provide a material delivery device capable of accurately setting an origin position of a plunger.SOLUTION: A material delivery device 14 includes: a plasticizing part 15 that plasticizes a resin pellet 17 to produce a plasticized material 18; a nozzle 16 having a nozzle opening 16a and delivering the plasticized material 18 to an outside from the nozzle opening 16a; a channel 31 communicating with the nozzle opening 16a and through which the plasticized material 18 flows; a suction part 33 having a plunger 37 for sucking the plasticized material 18 into a first cylinder 36 connected to the channel 31 and a plunger motor 41 for driving the plunger 37; and a detector 40 for detecting a position of the plunger 37 in the first cylinder 36.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a material feeding device, a three-dimensional shaping device, and an injection molding device.

Background Art

[0002] In a three-dimensional shaping device using a hot melt lamination method and an injection molding device, a material feeding device for feeding a plasticized material obtained by plasticizing a resin material is used. The resin material is also referred to as resin pellets. The resin material obtained by plasticizing resin pellets is referred to as a plasticized material or a shaping material.

[0003] The resin material is not limited to only thermoplastic resins. As long as the thermoplastic resin can be plasticized to have fluidity. Resin materials also include those obtained by mixing various substances such as metals, ceramics, and fibers with thermoplastic resins. In addition to pellets made of only thermoplastic resins, resin pellets also include pellets obtained by mixing various substances such as metals, ceramics, and fibers with thermoplastic resins.

[0004] In the material feeding device disclosed in Patent Document 1, a flat screw and a barrel are arranged opposite to each other. The flat screw is substantially disc-shaped and has a spiral groove formed based on an involute curve on a plane orthogonal to the rotation axis. The flat screw is rotated by a motor. The barrel includes a heater for melting resin pellets and a flow path through which the melted resin material passes. The resin pellets are melted and pressurized in the spiral groove. The plasticized material melted and pressurized is pressed into the flow path of the barrel. The plasticized material is sent out to the outside from the nozzle opening through the flow path of the barrel.

[0005] The barrel of the material dispensing device described in Patent Document 1 is equipped with a cylinder. A plunger is inserted into the cylinder. The plunger is moved by a plunger drive unit. One end of the cylinder is connected to a flow path through which the plasticizing material passes. The cylinder and plunger constitute a suction mechanism for sucking up the plasticizing material. When the dispensing of the plasticizing material is stopped, the plunger drive unit pulls the plunger to suck up the plasticizing material. The plunger suppresses the trailing of the plasticizing material from the nozzle opening, which would otherwise appear as a string. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2021-62566 [Overview of the project] [Problems that the invention aims to solve]

[0007] In a suction mechanism like the one described in Patent Document 1, conventionally, the position where the plunger protrudes most due to the pressure of the plasticizing material in the barrel's flow path was defined as the position where the plunger is most retracted. The plunger's origin was set by referring to this position. Alternatively, the plunger's origin was set by referring to the position where the plunger is most pushed into the cylinder when an operator pushes the plunger into the cylinder with their finger.

[0008] However, both the method using the pressure of the plasticizing material and the method where an operator pushes the plunger with their finger resulted in significant variation in the plunger's position. Therefore, there was a problem in accurately setting the plunger's origin position. [Means for solving the problem]

[0009] The material dispensing device comprises a plasticizing unit that plasticizes a material to produce a plasticizable material, a nozzle having a nozzle opening for dispensing the plasticizable material to the outside from the nozzle opening, a flow path communicating with the nozzle opening through which the plasticizable material flows, a suction unit having a plunger for drawing the plasticizable material into a cylinder connected to the flow path and a motor for driving the plunger, and a detection unit for detecting the position of the plunger in the cylinder.

[0010] The three-dimensional molding apparatus comprises the material delivery device described above and a stage for receiving the plasticizing material discharged from the nozzle of the material delivery device.

[0011] The injection molding apparatus comprises the material delivery device described above and a support part that detachably supports a mold, and injects the plasticizing material from the nozzle of the material delivery device toward the mold. [Brief explanation of the drawing]

[0012] [Figure 1] A schematic diagram showing the configuration of a three-dimensional molding apparatus related to the first embodiment. [Figure 2] A schematic side cross-sectional view showing the configuration of the material dispensing device. [Figure 3] A schematic perspective view showing a flat screw. [Figure 4] A schematic plan view illustrating the Scotch yoke mechanism. [Figure 5] A schematic plan view illustrating the Scotch yoke mechanism. [Figure 6] A schematic plan view illustrating the Scotch yoke mechanism. [Figure 7] A schematic plan view illustrating the Scotch yoke mechanism. [Figure 8] A schematic plan view illustrating the Scotch yoke mechanism. [Figure 9] Electrical block diagram of a 3D printing device. [Figure 10] A schematic plan view illustrating the Scotch yoke mechanism. [Figure 11]A diagram for explaining the holding torque applied to the output shaft of the plunger motor. [Figure 12] A diagram for explaining the relationship between the angle of the encoder and the holding torque of the plunger motor. [Figure 13] A schematic side cross-sectional view showing the configuration of the material feeding device according to the second embodiment. [Figure 14] A schematic side cross-sectional view showing the configuration of the injection molding device according to the third embodiment.

Embodiments for Carrying out the Invention

[0013] First Embodiment In this embodiment, a characteristic example of a three-dimensional shaping apparatus including a material feeding device will be described with reference to the drawings. In FIG. 1, arrows along the X, Y, and Z directions orthogonal to each other are shown. The X direction and the Y direction 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.

[0014] As shown in FIG. 1, the three-dimensional shaping apparatus 1 includes a base 2. A stage 3 is installed on the base 2. On the stage 3, a Y stage 4, an X stage 5, and a receiving plate 6 are installed in this order, stacked in the positive Z direction.

[0015] The Y stage 4 includes a Y-axis motor 4a, a ball screw, a Y-axis scale, etc. The Y stage 4 reciprocates the receiving plate 6 in the Y direction. The X stage 5 includes an X-axis motor 5a, a ball screw, an X-axis scale, etc. The X stage 5 reciprocates the receiving plate 6 in the X direction.

[0016] The three-dimensional shaping apparatus 1 includes a control unit 7. The control unit 7 controls the movement of the Y stage 4 and the X stage 5. The control unit 7 recognizes the position of the receiving plate 6 in the Y direction based on the information output by the Y-axis scale. The control unit 7 recognizes the position of the receiving plate 6 in the X direction based on the information output by the X-axis scale. The control unit 7 moves the Y stage 4 and the X stage 5 so that the difference between the target position and the current position of the receiving plate 6 disappears. The control unit 7 controls the trajectory of the movement of the receiving plate 6 by sequentially changing the target position of the movement of the receiving plate 6.

[0017] On the base 2, a lifting stage 8 is installed on the negative X direction side. The lifting stage 8 includes a fixed table 8a, and the fixed table 8a 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 in the Z direction along the rail 8b.

[0018] A Z-axis motor 8d is installed on the positive Z direction side of the fixed table 8a. The fixed table 8a includes a ball screw and a Z-axis scale inside. Similar to the Y stage 4 and the X stage 5, the control unit 7 controls the movement of the moving table 8c.

[0019] A unit support part 9 is installed on the positive X direction side of the moving table 8c. A shaping unit 11 is installed on the positive X direction side of the unit support part 9, and the unit support part 9 supports the shaping unit 11. In the shaping unit 11, a material supply part 12, a connecting pipe 13, and a material delivery device 14 are installed in this order toward the negative Z direction. Thus, the three-dimensional shaping device 1 includes the material delivery device 14. The material delivery device 14 includes a plasticizing part 15 and a nozzle 16.

[0020] In this embodiment, the stage 3 moves in the X direction and the Y direction, and the shaping unit 11 moves in the Z direction. The stage 3 may not move, and the shaping unit 11 may move in the X, Y, and Z directions. The stage 3 may move in the Z direction, and the shaping unit 11 may move in the X direction and the Y direction. The stage 3 may move in the X, Y, and Z directions.

[0021] The material supply part 12 is a container having a cavity inside. Resin pellets 17 as a material are accommodated inside the material supply part 12. The resin pellets 17 are in a pellet form. The size of the resin pellets 17 is not particularly limited, but in this embodiment, for example, it is within the range of 5 mm to 20 mm. Incidentally, the resin pellets 17 include materials containing metals, ceramics, carbon fibers, etc. in the resin or materials composed only of resin.

[0022] The connecting pipe 13 connects to the bottom of the material supply unit 12. The resin pellets 17 move from inside the material supply unit 12 into the connecting pipe 13 due to their own weight. The connecting pipe 13 connects to the plasticizing unit 15. The resin pellets 17 are supplied from the connecting pipe 13 to the plasticizing unit 15.

[0023] The plasticizing unit 15 plasticizes the resin pellets 17. "Plasticization" is a concept that includes melting and refers to changing a solid state to a fluid state. Specifically, in the case of materials that undergo a glass transition, plasticization means raising the temperature of the material above the glass transition point. In the case of materials that do not undergo a glass transition, plasticization means raising the temperature of the material above the melting point. The plasticizing unit 15 plasticizes the resin pellets 17 to produce a plasticized material 18.

[0024] The nozzle 16 discharges the plasticizing material 18 supplied from the plasticizing unit 15 onto the receiving plate 6. The receiving plate 6 of stage 3 receives the plasticizing material 18 discharged from the nozzle 16. While the nozzle 16 discharges the plasticizing material 18, the control unit 7 moves the receiving plate 6 in the X and Y directions. As a result, the three-dimensional molding apparatus 1 forms a layer of a predetermined pattern on the receiving plate 6. This layer is the first layer.

[0025] Next, the lifting stage 8 moves the molding unit 11 a predetermined distance in the positive Z direction. The three-dimensional molding apparatus 1 forms the second layer on top of the first layer. Furthermore, by layering the third and subsequent layers, the three-dimensional molding apparatus 1 forms a three-dimensional object 19. The object 19 is formed by the plasticizing material 18 extruded from the nozzle 16.

[0026] As shown in Figure 2, the plasticizing unit 15 includes a screw case 21. The screw case 21 is hollow inside. A screw motor 22 is installed on the Z-positive side of the screw case 21. The control unit 7 controls the rotation angle, rotation speed, start timing of rotation, and stop timing of rotation of the screw motor 22.

[0027] A reduction gear 23 is connected to the rotating shaft 22a of the screw motor 22. When the rotating shaft 22a rotates at high speed, the outer circumference of the reduction gear 23 rotates at a reduced speed. The outer circumference of the reduction gear 23 that rotates at a low speed becomes the output shaft 23a. A first bearing 24 is installed on the outer circumference of the reduction gear 23. The first bearing 24 is positioned between the screw case 21 and the reduction gear 23. The first bearing 24 rotatably supports the reduction gear 23.

[0028] A screw support unit 25 is installed on the output shaft 23a of the reduction gear 23. A flat screw 26 is installed on the screw support unit 25. The flat screw 26 is rotated by a screw motor 22. The flat screw 26 rotates in sync with the output shaft 23a. The flat screw 26 rotates around the rotation axis 22a of the screw motor 22. The screw rotation center 26d, which is the rotation center of the flat screw 26, is coaxial with the motor rotation center 22b, which is the rotation center of the screw motor 22.

[0029] As shown in Figures 2 and 3, the flat screw 26 has a groove-forming surface 26a on which helical grooves 26b are formed. The flat screw 26 has a substantially cylindrical shape in which the axial size of the rotation axis 22a is smaller than the size in the direction perpendicular to the axial size of the rotation axis 22a. In the illustrated example, two grooves 26b are provided, but the number of grooves 26b is not particularly limited. Although not shown, there may be three or more grooves 26b, or there may be only one.

[0030] The screw case 21 houses the reduction gear 23, the screw support section 25, and the flat screw 26. As shown in Figures 1 and 2, the screw case 21 is provided with a supply passage 21a that connects to the connecting pipe 13. The supply passage 21a extends from the connecting pipe 13 to the flat screw 26. The opening of the supply passage 21a on the flat screw 26 side is the passage opening 21b. The screw case 21 is provided with a passage opening 21b through which the resin pellets 17 pass toward the flat screw 26.

[0031] A barrel 27 is installed on the Z-negative side of the flat screw 26. The flat screw 26 rotates relative to the barrel 27.

[0032] As shown in Figure 2, the barrel 27 has an opposing surface 27a that faces the groove-forming surface 26a. Inside the barrel 27, a heater 28 is installed in a location opposite to the groove 26b. The heater 28 is a ceramic heater in which a heating element is arranged inside a ceramic tube.

[0033] The heater 28 heats the resin pellets 17 supplied between the flat screw 26 and the barrel 27. More specifically, the heater 28 heats the resin pellets 17 supplied between the groove-forming surface 26a and the opposing surface 27a. The heated resin pellets 17 are plasticized to become a plasticizing material 18. The barrel 27 is provided with a communication hole 29 through which the plasticizing material 18 formed from the plasticized resin pellets 17 flows.

[0034] The nozzle 16 has a nozzle opening 16a. The nozzle 16 discharges the plasticizing material 18 to the outside through the nozzle opening 16a. The barrel 27 and the nozzle 16 are equipped with a flow path 31 through which the plasticizing material 18 flows. The flow path 31 communicates with the nozzle opening 16a. The flow path 31 extends from the communication hole 29 to the nozzle opening 16a. The flow path 31 is arranged along the motor rotation center 22b.

[0035] In the barrel 27, a flow rate adjustment unit 32, a suction unit 33, and a pressure detection unit 34 are arranged in this order from the communication hole 29 toward the nozzle opening 16a. The flow rate adjustment unit 32, the suction unit 33, and the pressure detection unit 34 are connected to the flow path 31.

[0036] The flow rate adjustment unit 32 has a long, rod-like shape in the X direction. The flow rate adjustment unit 32 is provided with a through hole 32a in the radial direction. The flow rate adjustment unit 32 is perpendicular to the flow path 31. The through hole 32a is positioned in the flow path 31. A valve motor 35 is positioned on the negative X side of the flow rate adjustment unit 32. The flow rate adjustment unit 32 is connected to the rotation axis of the valve motor 35. The valve motor 35 rotates the flow rate adjustment unit 32. When the axial direction of the through hole 32a is parallel to the motor rotation center 22b, the plasticizing material 18 can easily pass through the through hole 32a. When the axial direction of the through hole 32a is perpendicular to the motor rotation center 22b, the plasticizing material 18 cannot pass through the through hole 32a. The flow rate of the plasticizing material 18 flowing through the flow path 31 can be adjusted by the valve motor 35 changing the axial angle of the through hole 32a with respect to the motor rotation center 22b. Flow rate represents how much material moves per unit time.

[0037] The suction unit 33 comprises a first cylinder 36 as a cylinder, a plunger 37, a connecting rod 38, a Scotch yoke mechanism 39, and a plunger motor 41 as a motor and detection unit. The plunger motor 41 is included in the detection unit 40. The first cylinder 36 is a hole formed in the barrel 27. One end of the first cylinder 36 is connected to the flow path 31. The plunger 37 is housed inside the first cylinder 36 and slides along the first cylinder 36. When the plunger 37 moves away from the flow path 31, the plunger 37 draws the plasticizing material 18 into the first cylinder 36. When the plunger 37 moves towards the flow path 31, the suction unit 33 releases the plasticizing material 18 inside the first cylinder 36 into the flow path 31.

[0038] The Scotch yoke mechanism 39 comprises a housing 42. The housing 42 is screw-fixed to the screw case 21. A first bearing 43 and a second bearing 44 are installed in the housing 42 on the X-positive side of the plunger 37. A reciprocating rod 45 is installed passing through the first bearing 43 and the second bearing 44. A connecting rod 38 connects the plunger 37 and the reciprocating rod 45. The first bearing 43 and the second bearing 44 are fitted with solid lubricant. The reciprocating rod 45 slides with low friction in the X-positive and X-negative directions relative to the first bearing 43 and the second bearing 44. The reciprocating rod 45 is prismatic in shape and has a non-rotating structure.

[0039] The plunger 37 and the connecting rod 38 are fixed together by a screw 46. The reciprocating rod 45 and the connecting rod 38 are fixed together by a screw 46. The connecting rod 38 can be attached and detached by operating the screw 46. The connecting rod 38 is removed from the plunger 37 and the reciprocating rod 45. After this, the plunger 37 can be removed from the first cylinder 36. Therefore, the plunger 37 is replaceable.

[0040] A yoke 47 is screw-fixed to the reciprocating rod 45. The yoke 47 has a groove 47a on its Z-positive side. The plunger motor 41 is installed on the Z-positive side of the housing 42. An encoder 41b is installed on the output shaft 41a of the plunger motor 41. The encoder 41b detects the rotation angle of the output shaft 41a. A crankpin 48 is fixed to the output shaft 41a. A second bearing 49 is positioned between the crankpin 48 and the housing 42. The crankpin 48 is rotatably held by the second bearing 49. The crank shaft 48a of the crankpin 48 is inserted into the groove 47a of the yoke 47.

[0041] The plunger motor 41 rotates the crankpin 48. Viewed from the Y direction, the crankshaft 48a reciprocates in the X direction. Pushed by the crankshaft 48a, the yoke 47 reciprocates in the X direction. The reciprocating rod 45, connecting rod 38, and plunger 37, which are fixed to the yoke 47, reciprocate in the X direction. In this way, the plunger motor 41 drives the plunger 37.

[0042] The plunger motor 41 has an ID mark 41c (Identification) on the side facing the screw case 21. An imaging device 51 is positioned on the screw case 21 opposite the ID mark 41c. The imaging device 51 photographs the ID mark 41c.

[0043] The pressure detection unit 34 comprises a second cylinder 52, a relay rod 53, and a pressure sensor 54 as the pressure detection unit. The second cylinder 52 is a hole formed in the barrel 27. One end of the second cylinder 52 is connected to the flow path 31. The relay rod 53 is housed inside the second cylinder 52 and slides along the second cylinder 52.

[0044] The pressure sensor 54 is connected to the X-negative end of the second cylinder 52. The plasticizing material 18 flowing through the channel 31 comes into contact with the relay rod 53. The pressure in the channel 31 presses against the pressure sensor 54 via the relay rod 53. The pressure sensor 54 detects the pressure of the plasticizing material 18 flowing in the channel 31. The plasticizing material 18 flowing through the channel 31 is hot, and can reach about 400 degrees Celsius. The relay rod 53 preferably has thermal insulation properties. For example, the relay rod 53 may be hollow and evacuated.

[0045] Next, the movement of the Scotch yoke mechanism 39 will be explained. As shown in Figure 4, the rotation center 41d of the output shaft 41a of the plunger motor 41 and the center 48b of the crankshaft 48a are separated. When the center 48b of the crankshaft 48a is located in the negative X direction relative to the rotation center 41d, the reciprocating rod 45 is located on the negative X side within its operating range.

[0046] The output shaft 41a of the plunger motor 41 rotates 90 degrees clockwise. The crankpin 48 rotates 90 degrees clockwise with respect to the rotation center 41d. As shown in Figure 5, the center 48b of the crankshaft 48a is located in the positive Y direction of the rotation center 41d. The reciprocating rod 45 is located in the center of its operating range.

[0047] Furthermore, the output shaft 41a of the plunger motor 41 rotates 90 degrees clockwise. The crankpin 48 rotates 90 degrees clockwise with respect to the rotation center 41d. As shown in Figure 6, the center 48b of the crankshaft 48a is located in the positive X direction relative to the rotation center 41d. The reciprocating rod 45 is located on the positive X side within its operating range.

[0048] Furthermore, the output shaft 41a of the plunger motor 41 rotates 90 degrees clockwise. The crankpin 48 rotates 90 degrees clockwise with respect to the rotation center 41d. As shown in Figure 7, the center 48b of the crankshaft 48a is located in the negative Y direction of the rotation center 41d. The reciprocating rod 45 is located in the center of its operating range.

[0049] Furthermore, the output shaft 41a of the plunger motor 41 rotates 90 degrees clockwise. The crankpin 48 rotates 90 degrees clockwise with respect to the rotation center 41d. As shown in Figure 8, the center 48b of the crankshaft 48a is located in the negative X direction relative to the rotation center 41d. The reciprocating rod 45 is located on the negative X side within its operating range. One rotation of the output shaft 41a of the plunger motor 41 causes the yoke 47 and the reciprocating rod 45 to make one reciprocating motion.

[0050] The suction unit 33 is connected to the plunger 37 and the output shaft 41a of the plunger motor 41 via a Scotch yoke mechanism 39. With this configuration, the suction unit 33 is equipped with a Scotch yoke mechanism 39. The Scotch yoke mechanism 39 can push the plunger 37 more strongly than a rack and pinion mechanism. The Scotch yoke mechanism 39 can pull the plunger 37 more strongly than a rack and pinion mechanism. Therefore, the plasticizing material 18 can be drawn from the flow path 31 into the first cylinder 36 and pushed out into the flow path 31.

[0051] When the flow rate of the plasticizing material 18 discharged from the nozzle opening 16a during molding is constant, the plunger 37 does not operate. When increasing the flow rate of the plasticizing material 18 discharged from the nozzle opening 16a, there is a delay in the increase in the flow rate of the plasticizing material 18 supplied from the flat screw 26 side. The plunger 37 pushes out the plasticizing material 18 in the first cylinder 36 to compensate for the delay in the increase in flow rate. When decreasing the flow rate of the plasticizing material 18 discharged from the nozzle opening 16a, there is a delay in the decrease in the flow rate of the plasticizing material 18 supplied from the flat screw 26 side. The plunger 37 pulls the plasticizing material 18 from the flow path 31 into the first cylinder 36 to compensate for the delay in the decrease in flow rate.

[0052] As shown in Figure 9, the control unit 7 includes a CPU 55 (Central Processing Unit) that performs various calculations and a memory 56 that stores various information. The motor drive unit 57, pressure sensor 54, heater 28, ID reading device 58, notification device 59 as a notification unit, input device 61, and output device 62 as a notification unit are connected to the CPU 55 via an input / output interface 63 and a data bus 64.

[0053] The motor drive unit 57 drives the Y-axis motor 4a, X-axis motor 5a, Z-axis motor 8d, screw motor 22, valve motor 35, and plunger motor 41. The motor drive unit 57 receives instruction signals from the CPU 55 and drives the Y-axis motor 4a, X-axis motor 5a, Z-axis motor 8d, screw motor 22, valve motor 35, and plunger motor 41 according to the conditions indicated by the instruction signals.

[0054] In addition, the motor drive unit 57 converts the rotation angle of the output shaft 41a of the plunger motor 41, detected by the encoder 41b, into angle information and transmits it to the CPU 55.

[0055] The plunger motor 41 is a DC motor. The current flowing through the coil of the plunger motor 41 is proportional to the torque of the output shaft 41a. The motor drive unit 57 calculates the torque of the output shaft 41a from the current flowing through the coil of the plunger motor 41. The motor drive unit 57 converts the torque of the output shaft 41a into torque information and transmits it to the CPU 55.

[0056] The pressure sensor 54 detects the pressure of the plasticizing material 18 flowing through the channel 31. The pressure sensor 54 converts the detected pressure into pressure information and transmits it to the CPU 55.

[0057] The heater 28 is equipped with a control circuit that controls the temperature. The heater 28 receives an instruction signal from the CPU 55 and maintains the temperature indicated by the instruction signal.

[0058] The ID reading device 58 is electrically connected to the imaging device 51. The imaging device 51 captures the ID mark 41c and transmits the image data of the ID mark 41c to the ID reading device 58. The ID reading device 58 processes the image data to extract the ID information and transmits it to the CPU 55.

[0059] The notification device 59 is equipped with a speaker and a light. The notification device 59 receives an alert signal from the CPU 55 and drives the speaker and light. The notification device 59 voices the content of the alert through the speaker. The notification device 59 flashes the light to attract the operator's attention.

[0060] The input device 61 is a keyboard, joystick, or the like. The operator uses the input device 61 to input various instructions.

[0061] The output device 62 is a display device or an external output device. The operator checks various information by looking at the display device. The output device 62 is equipped with an external interface for communicating with external devices. The display device receives an alert signal from the CPU 55 and displays the content of the alert in text and graphics.

[0062] Memory 56 is composed of semiconductor memory such as RAM (Random Access Memory) and ROM (Read Only Memory). Memory 56 stores a program 65 that describes the operation procedures of the three-dimensional molding device 1.

[0063] In addition, memory 56 stores torque data 66. Torque data 66 is torque data of the output shaft 41a of the plunger motor 41. The torque value of the output shaft 41a calculated by the motor drive unit 57 is included in the torque data 66.

[0064] In addition, memory 56 stores plunger data 67. Plunger data 67 includes information such as the length of the plunger 37 and the management number indicated on the ID mark 41c. Plunger data 67 also includes information on the replacement date. Plunger data 67 also includes data entered by the operator using the input device 61.

[0065] In addition, memory 56 stores material data 68. The material data 68 includes a table of the types of resin pellets 17 used. The material data 68 also includes information on what type of resin pellets 17 are being fed into the material supply unit 12.

[0066] In addition, memory 56 stores heater data 69. Heater data 69 includes information about the temperature maintained by heater 28. The temperature information is set for each type of resin pellet 17.

[0067] In addition, memory 56 stores flow rate data 71. The flow rate data 71 includes a target value for the flow rate of the plasticizing material 18 flowing through the channel 31. The flow rate data 71 also includes information showing the relationship between the type of resin pellet 17, the rotation speed of the flat screw 26, the temperature of the heater 28, and the flow rate of the plasticizing material 18 flowing through the channel 31.

[0068] Additionally, memory 56 stores the build data 72. The build data 72 is data that shows the procedure for moving stage 3 and lifting stage 8 in order to build the object 19.

[0069] In addition, the memory 56 stores judgment data 73. The judgment data 73 includes a first judgment value and a second judgment value for determining the pressure of the plasticizing material 18 flowing through the channel 31. The judgment data 73 also includes a judgment value for determining whether or not an abnormal state exists. Furthermore, the memory 56 includes a storage area that functions as a work area for the operation of the CPU 55, a temporary file, and various other storage areas.

[0070] The CPU 55 drives the three-dimensional molding apparatus 1 according to the program 65 stored in the memory 56. The CPU 55, on which the program 65 operates, has a pressure control unit 74 as a specific function implementation unit. The pressure control unit 74 outputs an instruction signal to the pressure sensor 54 to detect the pressure of the plasticizing material 18 flowing through the channel 31. The pressure control unit 74 receives the pressure value of the plasticizing material 18 flowing through the channel 31 from the pressure sensor 54. The pressure control unit 74 receives the first determination value and the second determination value included in the determination data 73 in the memory 56. The first determination value is the lower limit of the target pressure value of the plasticizing material 18 flowing through the channel 31. The second determination value is the upper limit of the target pressure value of the plasticizing material 18 flowing through the channel 31.

[0071] The pressure control unit 74 causes the motor drive unit 57 to adjust the rotational speed of the screw motor 22. There is a positive correlation between the rotational speed of the screw motor 22 and the pressure value of the plasticizing material 18 flowing through the flow path 31. When the pressure value of the plasticizing material 18 flowing through the flow path 31 is less than the first determination value, the motor drive unit 57 increases the rotational speed of the screw motor 22. When the pressure value of the plasticizing material 18 flowing through the flow path 31 is greater than the second determination value, the motor drive unit 57 decreases the rotational speed of the screw motor 22.

[0072] The pressure control unit 74 repeatedly detects the pressure value of the plasticizing material 18 using the pressure sensor 54 and adjusts the rotational speed of the screw motor 22 using the motor drive unit 57. The pressure control unit 74 adjusts the rotational speed of the screw motor 22 so that the value detected by the pressure sensor 54 of the pressure detection unit 34 is between a first determination value and a second determination value.

[0073] In addition, the CPU 55 has a home position setting unit 75 as a detection unit. The home position setting unit 75 is included in the detection unit 40. The home position setting unit 75 uses the plunger motor 41 to estimate the relationship between the position of the plunger 37 and the encoder 41b of the plunger motor 41. The encoder 41b is a scale that detects the rotation angle of the output shaft 41a. Next, the home position setting unit 75 sets the correspondence between the home position of the plunger 37 and the angle of the encoder 41b.

[0074] Specifically, the angle of the encoder 41b is measured when the plunger 37 moves furthest in the positive X direction. Next, the angle of the encoder 41b is calculated when the plunger 37 moves from its position at the furthest point in the positive X direction back to the origin. The distance between the position of the plunger 37 at its furthest point in the positive X direction and the origin is predetermined. This procedure allows for the correspondence between the origin position of the plunger 37 and the angle of the encoder 41b.

[0075] Alternatively, the angle of the encoder 41b is measured when the plunger 37 moves furthest in the negative X direction. Next, the angle of the encoder 41b is calculated when the plunger 37 moves back to the origin, based on the position of the plunger 37 when it reaches its furthest point in the negative X direction. The distance between the position of the plunger 37 when it moves furthest in the negative X direction and the origin is predetermined. This procedure allows the origin position of the plunger 37 to be associated with the angle of the encoder 41b.

[0076] In addition, the CPU 55 has an approximation formula calculation unit 76 as a detection unit. The approximation formula calculation unit 76 is included in the detection unit 40. The approximation formula calculation unit 76 calculates an approximation formula for multiple measured values ​​that show the relationship between the position of the plunger 37 and the angle of the encoder 41b. It then calculates the angle of the encoder 41b when the plunger 37 moves the furthest in the positive X direction, or when the plunger 37 moves the furthest in the negative X direction.

[0077] In addition, the CPU 55 has a heater control unit 77. The heater data 69 stored in the memory 56 contains information on the temperature at which the resin pellets 17 become plasticized. The temperature at which the resin pellets 17 become plasticized differs depending on the type of resin pellet 17. The heater control unit 77 receives the information on the plasticization temperature corresponding to the resin pellet 17 from the heater data 69 in the memory 56. The heater control unit 77 instructs the heater 28 to maintain the temperature at which the resin pellets 17 become plasticized. The heater 28 maintains the temperature indicated by the instruction signal.

[0078] In addition, the CPU 55 has a motor control unit 78. The motor control unit 78 outputs instruction signals to the motor drive unit 57 to control the screw motor 22, valve motor 35, and plunger motor 41.

[0079] In addition, the CPU 55 has a stage control unit 79. The stage control unit 79 outputs instruction signals to the motor drive unit 57 to control the Y-axis motor 4a, X-axis motor 5a, and Z-axis motor 8d.

[0080] In addition, the CPU 55 has a plunger control unit 80. The plunger control unit 80 controls the amount of movement of the plunger 37. By controlling the amount of movement of the plunger 37, the plunger control unit 80 controls the amount of plasticizing material 18 taken into the first cylinder 36 from the flow path 31 and the amount of plasticizing material 18 supplied from the first cylinder 36 to the flow path 31.

[0081] In addition, the CPU 55 has a notification control unit 81. When the notification control unit 81 notifies the operator of an abnormality, it outputs an alert instruction signal to the notification device 59 and the output device 62. The notification device 59 notifies an alert according to the alert instruction signal. The display device included in the output device 62 displays the alert content.

[0082] In addition, the CPU 55 has an input / output control unit 82. The input / output control unit 82 receives information input to the input device 61. The input / output control unit 82 transmits the received information to the function implementation unit related to that information. The input / output control unit 82 outputs the information to the output device 62. The input / output control unit 82 outputs an instruction signal to the output device 62 to display or transmit the information.

[0083] In addition, the CPU 55 has a plunger replacement monitoring unit 83. The plunger replacement monitoring unit 83 monitors whether at least a part of the suction unit 33 has been replaced or detached. The plunger data 67 in memory 56 stores the ID information of the plunger motor 41 when the power switch is turned off. When the power switch of the 3D printing apparatus 1 is turned on, the plunger replacement monitoring unit 83 inputs the ID information from the plunger data 67 in memory 56.

[0084] The plunger replacement monitoring unit 83 instructs the ID reading device 58 to acquire the ID information indicated on the currently installed ID mark 41c. The plunger replacement monitoring unit 83 receives the ID information from the ID reading device 58. The plunger replacement monitoring unit 83 compares the ID information stored in the memory 56 with the ID information indicated on the currently installed ID mark 41c. If the two pieces of ID information are different, it is determined that the suction unit 33 has been replaced.

[0085] The plunger replacement monitoring unit 83 monitors the information input to the input device 61. When at least a part of the installed suction unit 33 is replaced, the operator inputs the replacement details into the input device 61. At this time, the plunger replacement monitoring unit 83 determines that at least a part of the installed suction unit 33 has been replaced.

[0086] After the suction unit 33 is replaced, the plunger replacement monitoring unit 83 outputs an instruction signal to the origin setting unit 75 to detect the position of the plunger 37. The origin setting unit 75 detects the position of the plunger 37 according to the instruction signal.

[0087] In this way, after at least a portion of the installed suction unit 33 is replaced, the origin setting unit 75 detects the position of the plunger 37 inside the first cylinder 36. With this configuration, when the origin position of the plunger 37 changes by replacing at least a portion of the suction unit 33, the origin position of the plunger 37 can be set with high accuracy.

[0088] The plunger replacement monitoring unit 83 monitors the information input to the input device 61. When at least a part of the suction unit 33 that was attached is detached, the operator inputs the detachment details into the input device 61. At this time, the plunger replacement monitoring unit 83 determines that at least a part of the suction unit 33 that was attached has been detached.

[0089] After at least a portion of the suction unit 33 is removed, the origin setting unit 75 detects the position of the plunger 37 inside the first cylinder 36. With this configuration, the origin position of the plunger 37 can be accurately set when the origin position of the plunger 37 changes by removing at least a portion of the suction unit 33.

[0090] Next, the method for detecting the position of the plunger 37 will be explained. As shown in Figure 10, the crank line 84 is a line segment passing through the rotation center 41d of the plunger motor 41 and the center 48b of the crank shaft 48a of the crank pin 48. The angle formed by the crank line 84 and the central axis 45a of the reciprocating rod 45 is the crank angle 85. When the output shaft 41a of the plunger motor 41 rotates, the crank angle 85 changes from 0 degrees to 360 degrees. A pressure between a first determination value and a second determination value is applied to the plasticizing material 18 in the flow path 31 by the flat screw 26. When the plasticizing material 18 flows through the flow path 31, the pressure applied to the plasticizing material 18 is applied to the reciprocating rod 45 via the plunger 37.

[0091] When detecting the position of the plunger 37, the through-hole 32a of the flow rate adjustment unit 32 is aligned parallel to the motor rotation center 22b. This makes it easier for the plasticizing material 18 to pass through the through-hole 32a. The nozzle opening 16a remains open. The rotation speed of the flat screw 26 is set according to the material of the resin pellet 17. The rotation speed of the flat screw 26 is not particularly limited, but in this embodiment, for example, it is set to 6 rpm. When the pressure of the plasticizing material 18 is low, the rotation speed of the flat screw 26 is increased.

[0092] As shown in Figure 11, the crank pressing force 86 of the yoke 47 presses against the crankshaft 48a. The direction in which the yoke 47 pushes the crankpin 48 is in the axial direction of the reciprocating rod 45. When the yoke 47 is stopped, the crank pressing force 86 and the force with which the crankpin 48 pushes against the yoke 47 are of the same magnitude.

[0093] The crank pressing force 86 is the sum of the radial component force 87 directed from the center 48b of the crankpin 48 toward the rotation center 41d of the output shaft 41a and the circumferential component force 88 directed toward the circumference of the output shaft 41a. Let the crank angle 85 be "θ", the crank pressing force 86 be "F", and the circumferential component force 88 be "F1". Then F1 = F × sin(θ).

[0094] The distance between the rotation center 41d and the center 48b of the crankpin 48 is the eccentricity 89. Let "T" be the torque applied to the output shaft 41a of the plunger motor 41, and "r" be the eccentricity 89. Then T = F1 × r. Therefore, T = F × r × sin(θ).

[0095] Within the operating range of the yoke 47, the torque applied to the output shaft 41a of the plunger motor 41 is smallest when the yoke 47 reaches its furthest in the positive X direction and when the yoke 47 reaches its furthest in the negative X direction. Therefore, by detecting the angle of the encoder 41b when the torque applied to the output shaft 41a of the plunger motor 41 is minimized, the relationship between the angle of the encoder 41b and the position of the yoke 47 can be detected.

[0096] In Figure 12, the horizontal axis represents the angle of the encoder 41b. The vertical axis represents the holding torque required for the plunger motor 41 to hold the rotation of the output shaft 41a in a stopped state. The lower side indicates a smaller holding torque than the upper side. The holding torque is detected each time the output shaft 41a is rotated by 15 degrees. The detected holding torque is then plotted against the rotation angle of the output shaft 41a.

[0097] The approximation calculation unit 76 calculates an approximation curve 91 of the plotted data. The approximation curve 91 is a trigonometric function curve. Using "A" and "B" as coefficients, the approximation calculation unit 76 approximates the plotted data with the approximation formula T = A × sin(θ-B). The origin setting unit 75 sets the location where the holding torque value shown by the approximation curve 91 is smallest as the reference point 92. The reference point 92 is either the location where the yoke 47 reaches furthest in the positive X direction or the location where the yoke 47 reaches furthest in the negative X direction within the operating range of the yoke 47. In this way, the origin setting unit 75 and the plunger motor 41 detect the position of the plunger 37 inside the first cylinder 36.

[0098] With this configuration, the detection unit 40, which includes the origin setting unit 75 and the plunger motor 41, can detect the position of the plunger 37. Therefore, the plunger 37 can be operated accurately, and the origin position of the plunger 37 can be set accurately.

[0099] The origin setting unit 75 sets the origin at a location at a predetermined angle away from the angle of the encoder 41b indicated by the reference point 92. Alternatively, the reference point 92 may be used as the origin. The angle of the encoder 41b and the position of the plunger 37 correspond accurately. In Figure 10, the crank angle 85 is denoted as "θ", the eccentricity 89 as "r", and the positive Y direction as "+". In the axial direction of the central axis 45a, the position of the center 48b of the crankpin 48 relative to the rotation center 41d of the output shaft 41a is given by r × (-cos(θ)). The amount of movement of the crankpin 48 in response to a change in θ is larger and more linear when θ is around 90 degrees compared to when θ is around 0 or 180 degrees. Therefore, the origin is set when θ is around 90 degrees. More specifically, the origin is set when θ is between 60 and 90 degrees. The output shaft 41a waits at the angle corresponding to the origin. In this case, the suction unit 33 can draw up a larger amount of plasticizing material 18 compared to when the origin is set between 90 and 120 degrees.

[0100] The detection unit 40, which includes the origin setting unit 75 and the plunger motor 41, preferably detects the position of the plunger 37 in the first cylinder 36 based on the torque value of the plunger motor 41 when the plunger 37 maintains a predetermined position under the condition that a predetermined range of pressure is applied to the plunger 37.

[0101] In this configuration, the origin setting unit 75 uses the plunger motor 41 to detect the position of the plunger 37. Therefore, since no sensor is required to detect the position of the plunger 37, the number of parts can be reduced.

[0102] The origin setting unit 75 preferably detects the position of the plunger 37 in the first cylinder 36 based on multiple holding torque values. With this configuration, torque values ​​at multiple positions are detected by changing the position of the plunger 37. By using multiple data points of the plunger 37 position and the holding torque value to determine the approximate formula for the approximation curve 91, detection errors can be reduced, and the relationship between the position of the plunger 37 and the holding torque value can be determined with high accuracy. By determining the approximate formula for the approximation curve 91, the measurement errors of the reference point and the origin can be reduced to 4% or less.

[0103] Multiple torque values ​​of the holding torque when the plunger 37 is stopped at a predetermined position may be detected. Then, an approximate formula calculation may be performed using the multiple detected torque values. Preferably, the origin setting unit 75 detects the position of the plunger 37 in the first cylinder 36 based on the multiple holding torque values. With this configuration, the number of detected torque values ​​increases, so the error is reduced. Therefore, the torque value can be detected with high accuracy.

[0104] It is preferable that the detection unit 40, including the origin setting unit 75 and the plunger motor 41, detects the position of the plunger 37 in the first cylinder 36 before the molding of the object 19 begins. With this configuration, the object 19 is molded after the position of the plunger 37 has been detected. Because the origin position of the plunger 37 is detected with high accuracy, the material delivery device 14 can accurately deliver the plasticizing material 18 from the nozzle opening 16a. Therefore, the plunger 37 can be operated accurately when the object 19 is molded.

[0105] When at least one of the following changes—the type of plasticizing material 18, the temperature conditions of the heater 28 of the plasticizing section 15, or the flow rate of the plasticizing section 15—the torque value of the holding torque of the encoder 41b at each angle changes. Consequently, the coefficient of the approximation formula calculated by the approximation formula calculation unit 76 changes. The judgment data 73 includes a coefficient judgment value for determining the coefficient of the approximation formula. The origin setting unit 75 compares the coefficient of the approximation formula calculated by the approximation formula calculation unit 76 with the coefficient judgment value to make a determination. When the coefficient of the approximation formula changes, the origin setting unit 75 can detect that at least one of the following has changed: the type of plasticizing material 18, the temperature conditions of the heater 28 of the plasticizing section 15, or the flow rate of the plasticizing section 15.

[0106] The detection unit 40, which includes the origin setting unit 75 and the plunger motor 41, may also detect whether at least one of the following conditions matches a preset condition: the type of plasticizing material 18, the temperature conditions of the heater 28 of the plasticizing unit 15, or the flow rate of the plasticizing unit 15.

[0107] With this configuration, the approximation calculation unit 76 accurately determines the relationship between the position of the plunger 37 and the torque value of the holding torque. When at least one of the following conditions—the type of plasticizing material 18, the temperature conditions of the heater 28 of the plasticizing unit 15, or the flow rate of the plasticizing unit 15—does not match the preset conditions, the relationship between the position of the plunger 37 and the torque value of the holding torque falls outside the predetermined range. Therefore, it is possible to detect when at least one of the following conditions—the type of plasticizing material 18, the temperature conditions of the heater 28 of the plasticizing unit 15, or the flow rate of the plasticizing unit 15—does not match the preset conditions. This makes it possible to suppress the discharge of the plasticizing material 18 from the nozzle opening 16a under conditions outside the predetermined range.

[0108] The position detection of the plunger 37 is performed when the origin setting unit 75 detects the angle of the encoder 41b at the reference point 92. The reference point 92 calculated from the position detection of the plunger 37 is the detected value. The position detection of the plunger 37 is performed periodically from the time the three-dimensional molding device 1 starts operation.

[0109] After the three-dimensional modeling apparatus 1 starts operation, the origin setting unit 75 stores the angle of the encoder 41b indicated by the reference point 92 and the angle of the encoder 41b at the origin as one of the plunger data 67 in the memory 56. Therefore, the memory 56 stores data showing the history of the angles of the encoder 41b at the reference point 92 and the origin.

[0110] When the position of the plunger 37 is detected n times for a natural number n, the memory 56 stores data of the reference point 92 and the angle of the encoder 41b at the origin, calculated from the nth position detection of the plunger 37. Next, when the position of the plunger 37 is detected for the (n+1)th time, the memory 56 stores data of the reference point 92 and the angle of the encoder 41b at the origin, calculated from the (n+1)th position detection of the plunger 37.

[0111] The judgment data 73 in memory 56 stores the reference point difference judgment value. The origin setting unit 75 compares the difference between the nth and (n+1)th reference points 92 with the reference point difference judgment value. If the absolute value of the difference between the nth and (n+1)th reference points 92 is greater than the reference point difference judgment value, the origin setting unit 75 works in conjunction with the notification control unit 81 to send an alert to the notification device 59.

[0112] Thus, it is preferable that the origin setting unit 75 alerts the notification device 59 if, while no part of the plunger 37 has been replaced or detached, the detected value differs by a predetermined value between the nth position detection of the plunger 37 and the (n+1)th position detection of the plunger 37.

[0113] In this configuration, the origin setting unit 75 and the plunger motor 41 detect the position of the plunger 37 within the first cylinder 36. By detecting the position of the plunger 37, the range of movement of the plunger 37 is detected. If the range of movement of the plunger 37 deviates by a predetermined value between the nth detection and the (n+1)th detection, an alert is issued. When the material dispensing device 14 is in an abnormal state, the detected value deviates by a predetermined value. Therefore, an abnormality in the material dispensing device 14 can be reported.

[0114] To plot the holding torque data shown in Figure 12, the angle of the encoder 41b is changed and the holding torque of the plunger motor 41 is detected. The origin setting unit 75 detects the holding torque on the nth time by setting the angle of the encoder 41b to a predetermined angle. On the (n+1)th time, the origin setting unit 75 detects the holding torque by changing the angle of the encoder 41b by a predetermined angle.

[0115] The origin setting unit 75 compares the difference in holding torque calculated between the nth time and the (n+1)th time with a holding torque difference determination value. If the absolute value of the difference in holding torque calculated between the nth time and the (n+1)th time is greater than the holding torque difference determination value, the origin setting unit 75 works in conjunction with the notification control unit 81 to send an alert to the notification device 59.

[0116] The angle of the encoder 41b is changed between the nth and (n+1)th measurements to detect the position of the plunger 37. At this time, if the detection value of the plunger 37 differs by more than a predetermined value between the nth position detection and the (n+1)th position detection, the origin setting unit 75 will cause the notification device 59 to send an alert.

[0117] The movement of the plunger 37 and the detection of the plunger 37's position are performed alternately. If the detected value differs by more than a predetermined value between the nth position detection of the plunger 37 and the (n+1)th position detection of the plunger 37, an alert is issued. Thus, it is possible to notify of abnormalities in the three-dimensional molding apparatus 1 caused by the movement of the plunger 37.

[0118] It is preferable that the origin setting unit 75 and the plunger motor 41 detect the position of the plunger 37 in the first cylinder 36 under the condition that the detected value of the pressure sensor 54 of the pressure detection unit 34 is between a first determination value and a second determination value.

[0119] With this configuration, the pressure of the plasticizing material 18 in the flow path 31 is adjusted to a range between a first determination value and a second determination value. The first and second determination values ​​are set within a range in which the origin setting unit 75 and the plunger motor 41 can detect the position of the plunger 37. Therefore, the origin setting unit 75 and the plunger motor 41 can accurately detect the position of the plunger 37.

[0120] The three-dimensional molding apparatus 1 comprises a material delivery device 14 and a stage 3. With this configuration, the three-dimensional molding apparatus 1 includes a material delivery device 14. The material delivery device 14 can accurately set the origin position of the plunger 37. Therefore, the three-dimensional molding apparatus 1 can be a device equipped with a material delivery device 14 that can accurately set the origin position of the plunger 37.

[0121] Second Embodiment The difference between this embodiment and the first embodiment lies in the sensor used to detect the position of the plunger 37. Note that components identical to those in the first embodiment are denoted by the same reference numerals, and redundant explanations are omitted.

[0122] As shown in Figure 13, the material delivery device 103 in the molding unit 102 of the three-dimensional molding apparatus 101 is equipped with a suction section 104. In the suction section 104, a reciprocating rod 105 is installed, passing through the first bearing 43 and the second bearing 44. A connecting rod 38 connects the plunger 37 and the reciprocating rod 105. The reciprocating rod 105 is prismatic in shape and has a non-rotating structure.

[0123] A reflector 106 is positioned on the reciprocating rod 105 in both the negative Z and negative Y directions. The reflector 106 has a reflective surface on the positive X direction side. A distance sensor 107 is installed on the negative Z side of the housing 42 as a detection unit. The distance sensor 107 detects the distance between itself and the reflector 106.

[0124] The type of distance sensor 107 is not particularly limited. Optical, capacitive, magnetic, etc., can be used. In this embodiment, for example, the distance sensor 107 is an optical sensor. The distance sensor 107 shines light 108 onto the reflector 106. The distance sensor 107 receives the light 108 reflected by the reflector 106 and detects the position of the reflector 106. The distance sensor 107 measures the distance between the distance sensor 107 and the reflector 106 using triangulation.

[0125] The distance sensor 107 is fixed to the housing 42. The housing 42 is fixed to the screw case 21. The screw case 21 is fixed to the barrel 27. A first cylinder 36 is formed in the barrel 27. The relative position between the distance sensor 107 and the first cylinder 36 is known. The reflector 106 is fixed to the reciprocating rod 105. The reflector 106 is linked to the plunger 37. The relative position between the reflector 106 and the plunger 37 is also known.

[0126] By measuring the distance between the distance sensor 107 and the reflector 106, the distance sensor 107 detects the position of the plunger 37 inside the first cylinder 36. With this configuration, the distance sensor 107 can detect the position of the plunger 37. Therefore, the plunger 37 can be operated accurately. The origin position of the plunger 37 can be set accurately.

[0127] Third Embodiment This embodiment describes an example of an injection molding apparatus equipped with a material delivery device corresponding to the material delivery device 14 of the first embodiment.

[0128] As shown in Figure 14, the injection molding apparatus 120 comprises a material delivery device 121, a mold 122, a mold support 123 as a support part, a mold clamping device 124, and a control unit 125. The material delivery device 121 corresponds to the material delivery device 14 of the first embodiment.

[0129] The material delivery device 121 has a plasticizing section 126, a nozzle 127, a flow path 128, a suction section 129, and a detection section 131. The plasticizing section 126, nozzle 127, flow path 128, suction section 129, and detection section 131 correspond to the plasticizing section 15, nozzle 16, flow path 31, suction section 33, and detection section 40 of the first embodiment, respectively. The plasticizing section 126 has a flat screw 132 and a barrel 133. An injection cylinder 134 is connected to the flow path 128 formed in the barrel 133. The injection cylinder 134 corresponds to the first cylinder 36 of the first embodiment. Under the control of the control unit 125, the material delivery device 121 plasticizes the resin pellets 17 supplied to the groove 135 of the flat screw 132, generating a fluid paste-like plasticizing material 18, which is then guided from the flow path 128 to the suction section 129.

[0130] The suction unit 129 comprises an injection cylinder 134, a plunger 136, a yoke 137, a crankpin 138, a motor, and a plunger motor 139 as a detection unit. The plunger 136 corresponds to the combined plunger 37, connecting rod 38, and reciprocating rod 45 of the first embodiment. The yoke 137, crankpin 138, and plunger motor 139 correspond to the yoke 47, crankpin 48, and plunger motor 41 of the first embodiment.

[0131] The suction unit 129 injects the plasticizing material 18 from the injection cylinder 134 into the cavity 141. Under the control of the control unit 125, the suction unit 129 controls the amount of plasticizing material 18 injected from the nozzle 127. The injection cylinder 134 is a substantially cylindrical member connected to the flow path 128 of the barrel 133 and has a plunger 136 inside. The plunger 136 slides inside the injection cylinder 134 and pressurizes the plasticizing material 18 inside the injection cylinder 134 to the nozzle 127 connected to the material delivery device 121. The plunger 136 is driven by a plunger motor 139.

[0132] The molding die 122 comprises a movable mold 142 and a fixed mold 143. The molding die 122 is removably held by a mold support 123. The movable mold 142 and the fixed mold 143 are arranged facing each other, and a cavity 141, which is a space corresponding to the shape of the molded product, is formed between them. Plasticizing material 18, which is pressurized by a suction unit 129, is injected into the cavity 141 via a nozzle 127.

[0133] The clamping device 124 includes a mold drive unit 144. The mold drive unit 144 opens and closes the movable mold 142 and the fixed mold 143. Under the control of the control unit 125, the clamping device 124 drives the mold drive unit 144 to move the movable mold 142 and open and close the movable mold 142 and the fixed mold 143.

[0134] The injection molding apparatus 120 includes a material delivery device 121 and a mold support section 123 that detachably supports the mold 122. The material delivery device 121 corresponds to the material delivery device 14 of the first embodiment. Plasticizing material 18 is injected from the nozzle 127 of the material delivery device 121 toward the mold 122.

[0135] According to this configuration, the injection molding apparatus 120 is equipped with a material delivery device 121, which corresponds to the material delivery device 14 described in the first embodiment. The material delivery device 121 can accurately set the origin position of the plunger 136. Therefore, the injection molding apparatus 120 can be equipped with a material delivery device 121 that can accurately set the origin position of the plunger 136. As a result, the injection molding apparatus 120 can inject a precisely measured amount of plasticizing material 18 into the mold 122.

[0136] Furthermore, the injection molding apparatus 120 may also be equipped with a material delivery device 121, which corresponds to the material delivery device 103 described in the second embodiment. In this case as well, the injection molding apparatus 120 can be equipped with a material delivery device 121 that can accurately set the origin position of the plunger 136. As a result, the injection molding apparatus 120 can accurately measure and inject the plasticizing material 18 into the mold 122. [Explanation of symbols]

[0137] 3...stage, 14,103,121...material dispensing device, 15,126...plasticizing unit, 16,127...nozzle, 16a...nozzle opening, 17...resin pellets as material, 18...plasticizing material, 19...molded object, 28...heater, 31,128...flow channel, 34...pressure detection unit, 36...first cylinder as cylinder, 37,136...plunger, 39...Scotch yoke mechanism, 40,131...detection unit, 41,139...plunger motor as motor and detection unit, 54...pressure sensor as pressure detection unit, 59...notification device as notification unit, 62...output device as notification unit, 75...origin setting unit as detection unit, 76...approximation formula calculation unit as detection unit, 107...distance sensor as detection unit, 122...molding mold, 123...mold support unit as support unit, 129...suction unit.

Claims

1. A plasticizing unit that plasticizes materials to produce plasticizable materials, A nozzle having a nozzle opening, which discharges the plasticizing material from the nozzle opening to the outside, A flow path that communicates with the nozzle opening and through which the plasticizing material flows, A suction unit having a plunger for drawing in the plasticizing material within a cylinder connected to the flow path, and a motor for driving the plunger, wherein the motor output shaft and the plunger are connected via a Scotch yoke mechanism, The system includes a detection unit that detects the position of the plunger within the cylinder based on the torque value of the motor when the plunger maintains a fixed position under conditions where a predetermined range of pressure is applied to the plunger, The material dispensing device is characterized in that the detection unit detects the position of the plunger in the cylinder based on a plurality of torque values.

2. A material dispensing device according to claim 1, The plasticizing material extruded from the nozzle forms the object. A material dispensing device characterized in that the detection unit detects the position of the plunger inside the cylinder before the molding of the aforementioned object is started.

3. A material dispensing device according to claim 1 or claim 2, A material dispensing device characterized in that, after at least a portion of the suction unit that was attached has been replaced, the detection unit detects the position of the plunger in the cylinder.

4. A material dispensing device according to any one of claims 1 to 3, A material dispensing device characterized in that, after at least a part of the suction unit is detached, the detection unit detects the position of the plunger in the cylinder.

5. A material dispensing device according to any one of claims 1 to 4, The material dispensing device is characterized in that the detection unit detects whether at least one of the type of plasticizing material, the temperature conditions of the heater in the plasticizing unit, or the flow rate of the plasticizing unit matches a preset condition.

6. A material dispensing device according to any one of claims 1 to 5, The material dispensing device is characterized in that, when the detection unit has not replaced or removed any part of the plunger, and the detected value differs by a predetermined value or more between the nth plunger position detection and the (n+1)th plunger position detection, the detection unit causes the notification unit to issue an alert.

7. A material dispensing device according to any one of claims 1 to 6, A material delivery device having a pressure detection unit for detecting the pressure of the plasticizing material in the flow path, characterized in that the detection unit detects the position of the plunger in the cylinder under the condition that the detected value of the pressure detection unit is between a first determination value and a second determination value.

8. A material delivery device according to any one of claims 1 to 7, A three-dimensional molding apparatus comprising a stage for receiving the plasticizing material discharged from the nozzle of the material dispensing device.

9. A material delivery device according to any one of claims 1 to 7, It has a support part that detachably supports the mold, An injection molding apparatus characterized by injecting the plasticizing material from the nozzle of the material dispensing device toward the molding die.

Images