Measurement method for 3D printing equipment

Abstract

This invention provides a measurement method for a three-dimensional 3D printing device that can improve detection accuracy. [Solution] The system includes a first pressure measurement step in which the pressure of the pressure generating unit 500 is measured as first pressure data, a second pressure measurement step in which the measurement unit 240 measures the pressure generated by the pressure generating unit 500 biasing the plunger pin as second pressure data, and a third pressure measurement step in which the difference between the first pressure data and the second pressure data is measured.

Description

Technical Field

[0001] The present invention relates to a measurement method for a three-dimensional shaping apparatus.

Background Art

[0002] Patent Document 1 discloses a configuration of a three-dimensional shaping apparatus that injects a plasticized material in an injection cylinder into a mold through a nozzle by sliding an injection plunger in the injection cylinder. The flow rate of the plasticized material is controlled based on the detection value of a pressure detection unit that detects the pressure of the plasticized material. Since the flow rate changes when the plasticized material accumulates and adheres in the injection cylinder, it is necessary to perform maintenance regularly.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the configuration described in Patent Document 1 has a problem that it is difficult to confirm whether the pressure detection unit can detect an accurate detection value after maintenance.

Means for Solving the Problems

[0005] A measurement method for a three-dimensional molding apparatus comprises a flow path through which a plasticizing material, plasticized by heat, flows; a nozzle communicating with the flow path and sending the plasticizing material to the outside; a pressure detection unit for detecting the pressure of at least a portion of the flow path; and a pressure generating unit connected to the pressure detection unit and generating pressure, wherein the pressure detection unit comprises a cylinder connected to the flow path; a plunger pin slidably arranged inside the cylinder; a transmission member connected to the plunger pin on the side opposite to the flow path; and a measurement unit connected via the transmission member for measuring the pressure received by the plunger pin from the plasticizing material, and further comprises a first pressure measurement step of measuring the pressure of the pressure generating unit as first pressure data; a second pressure measurement step of the measurement unit measuring the pressure generated by the pressure generating unit biasing the plunger pin as second pressure data; and a third pressure measurement step of measuring the difference between the first pressure data and the second pressure data. [Brief explanation of the drawing]

[0006] [Figure 1] A schematic diagram showing the configuration of a three-dimensional printing device. [Figure 2] A perspective view showing the configuration of the groove-forming surface side of the screw. [Figure 3] A plan view showing the configuration of the barrel on the side opposite the screw. [Figure 4] A cross-sectional view showing the configuration of the pressure detection unit. [Figure 5] A cross-sectional view of the pressure detection unit along the VV line shown in Figure 4. [Figure 6] A magnified side view of section A of the three-dimensional printing apparatus shown in Figure 1. [Figure 7] A cross-sectional view showing a magnified view of section A of the three-dimensional printing apparatus shown in Figure 1. [Figure 8] A plan view of the pressure detection unit, seen from below. [Figure 9] A perspective view showing the configuration of the pressure generation section. [Figure 10] A perspective view showing the configuration of the pressure generation section. [Figure 11] A perspective view showing the configuration of the main body of the pressure generating unit. [Figure 12] A flowchart illustrating the measurement method for a 3D printing device. [Figure 13] A perspective view illustrating part of the measurement method for a three-dimensional printing device. [Figure 14] A perspective view illustrating part of the measurement method for a three-dimensional printing device. [Figure 15] A graph showing the relationship between thrust and pressure. [Modes for carrying out the invention]

[0007] The following describes the 3D printing apparatus 100 and the measurement method for the 3D printing apparatus 100, with reference to the drawings. In the following diagrams, the three mutually orthogonal axes are described as the X-axis, Y-axis, and Z-axis. The direction along the X-axis is called the "X direction," the direction along the Y-axis is called the "Y direction," and the direction along the Z-axis is called the "Z direction." The direction of the arrow is the + direction, and the direction opposite to the + direction is called the - direction. Viewing from the +Z direction or -Z direction is also called a planar view or planar perspective.

[0008] First, the configuration of the three-dimensional molding apparatus 100 will be explained with reference to Figure 1.

[0009] As shown in Figure 1, the three-dimensional molding apparatus 100 includes a material delivery device 150, a stage 300, a position changing unit 400, and a control unit 600.

[0010] The control unit 600 controls the operation of the entire three-dimensional molding apparatus 100 and executes the molding process to create three-dimensional objects. The control unit 600 is composed of a computer equipped with one or more processors and main memory. The control unit 600 performs various functions by having the processor execute a program loaded into the main memory.

[0011] Furthermore, some of the functions of the control unit 600 may be implemented by hardware circuits. In the molding process performed by the control unit 600, the material delivery device 150 and the position changing unit 400 are controlled according to the molding data of the three-dimensional object.

[0012] Under the control of the control unit 600, the material delivery device 150 melts the solid-state material and delivers the plasticized material in a paste form to the outside. The material delivery device 150 discharges the plasticized material onto a shaping stage 300 that serves as the base of the three-dimensional shaped object.

[0013] The material delivery device 150 includes a material supply unit 20 that is a source of the material before being converted into the plasticized material, a plasticizing unit 30 that plasticizes the material by the rotation of a screw 40 to generate the plasticized material, a flow path 66 through which the generated plasticized material flows, a nozzle 61 that communicates with the flow path 66 and discharges the plasticized material to the outside, and a pressure detection unit 200 that is connected to the flow path 66 and detects the pressure of the plasticized material in the flow path 66. Further, a delivery amount adjustment unit 70 is disposed in the flow path 66, and a suction and discharge unit 75 is connected thereto.

[0014] The material supply unit 20 stores materials in the form of pellets, powders, etc. In this embodiment, ABS resin formed into pellets is used as the material. The material supply unit 20 is constituted by a hopper. Below the material supply unit 20, a supply path 22 that connects between the material supply unit 20 and the plasticizing unit 30 is provided. The material supply unit 20 supplies the material to the plasticizing unit 30 via the supply path 22.

[0015] The plasticizing unit 30 includes a screw case 31, a drive motor 32, a screw 40, a barrel 50, and a plasticizing heater 58. The plasticizing unit 30 plasticizes at least a part of the material supplied from the material supply unit 20 by the rotation of the screw 40 and generates a paste-like plasticized material having fluidity. The plasticizing unit 30 supplies the generated plasticized material to the nozzle 61 via the flow path 66 provided between the screw 40 and the nozzle 61.

[0016] "Plasticization" is a concept that includes melting and refers to changing a solid state to a fluid state. Specifically, for materials that undergo a glass transition, plasticization means raising the material's temperature above its glass transition point. For materials that do not undergo a glass transition, plasticization means raising the material's temperature above its melting point. Screw 40 is a so-called flat screw, sometimes called a "scroll."

[0017] The screw case 31 is a housing for the screw 40. The barrel 50 is fixed to the lower surface of the screw case 31, and the screw 40 is housed in the space enclosed by the screw case 31 and the barrel 50. The screw 40 has a groove-forming surface 42 on the surface facing the barrel 50, with grooves 45 formed therein.

[0018] A drive motor 32 is fixed to the upper surface of the screw case 31. The rotation axis of the drive motor 32 is connected to the upper surface 41 of the screw 40. Note that the drive motor 32 does not have to be directly connected to the screw 40; for example, the screw 40 and the drive motor 32 may be connected via a reduction gear. The drive motor 32 is driven under the control of the control unit 600.

[0019] The barrel 50 is positioned below the screw 40. The barrel 50 has a screw-facing surface 52 that faces the groove-forming surface 42 of the screw 40. The barrel 50 is provided with a communication hole 56 on the central axis AX of the screw 40. The communication hole 56 forms part of the flow path 66 described above.

[0020] More specifically, the flow path 66 is formed by a communication hole 56 and a supply flow path 67. The supply flow path 67 is a flow path connecting the communication hole 56 and the nozzle 61. Note that the supply flow path 67 is not required, and the communication hole 56 and the nozzle 61 may be directly connected.

[0021] The plasticizing heater 58 is built into the barrel 50, opposite the groove 45 of the screw 40. The plasticizing heater 58 heats the material supplied between the screw 40 and the barrel 50. The temperature of the plasticizing heater 58 is controlled by the control unit 600.

[0022] Next, the configuration of the screw 40 will be explained with reference to Figure 2.

[0023] As shown in Figure 2, the central portion 47 of the groove-forming surface 42 of the screw 40 is configured as a recess to which one end of the groove 45 is connected. As shown in Figure 3, the central portion 47 faces the communication hole 56 of the barrel 50. The central portion 47 intersects with the central axis AX.

[0024] The groove 45 constitutes a so-called scroll groove. The groove 45 extends in a spiral shape, arcing from the central portion 47 toward the outer circumference of the screw 40. The groove-forming surface 42 is provided with convex portions 46 that form the side walls of the groove 45 and extend along each groove 45. The groove 45 continues to the material inlet 44 formed on the side surface 43 of the screw 40.

[0025] The material inlet 44 is the part that receives the material supplied through the supply passage 22 of the material supply unit 20. The material received by the material inlet 44 is supplied between the screw 40 and the barrel 50.

[0026] As shown in Figure 2, the grooves 45 are formed in three sections separated by the convex portions 46. The number of grooves 45 is not limited to three; there may be one or two or more. The grooves 45 are not limited to a spiral shape; they may be helical or involute curves, or they may extend in an arc from the central portion 47 toward the outer circumference.

[0027] Next, the configuration of the screw-facing surface 52 of the barrel 50 will be described with reference to Figure 3.

[0028] As shown in Figure 3, a communication hole 56 is formed in the center of the screw-facing surface 52. Multiple guide grooves 54 are formed around the communication hole 56 on the screw-facing surface 52.

[0029] Each guide groove 54 has one end connected to a communication hole 56 and extends in a spiral shape from the communication hole 56 toward the outer circumference of the screw-facing surface 52. Each guide groove 54 has the function of guiding the plasticizing material into the communication hole 56. Note that one end of the guide groove 54 does not have to be connected to the communication hole 56. Also, the barrel 50 does not have to have guide grooves 54 formed therein.

[0030] As shown in Figure 1, the plasticizing unit 30 generates plasticizable material by heating the material supplied between the screw 40 and the barrel 50 while conveying it toward the flow path 66 using the screw 40, barrel 50 and plasticizing heater 58 described above, and then supplies the generated plasticizable material to the nozzle 61 via the flow path 66.

[0031] The nozzle 61 comprises a nozzle channel 65 and a tip surface 63 on which a nozzle opening 62 is provided. The nozzle channel 65 is a channel for plasticizing material formed inside the nozzle 61 and is in communication with the channel 66 described above.

[0032] Specifically, the nozzle channel 65 is connected to the supply channel 67 described above. The tip surface 63 is the surface that constitutes the tip portion of the nozzle 61 that protrudes in the -Z direction toward the molding surface 311. The nozzle opening 62 is a portion of the nozzle channel 65 where the channel cross-section is reduced, and is provided at the end of the nozzle channel 65 that communicates with the atmosphere. The plasticizing material generated by the plasticizing unit 30 is supplied to the nozzle 61 via the channel 66 and discharged from the nozzle opening 62 via the nozzle channel 65.

[0033] A nozzle heater 68 is provided around the nozzle channel 65. Under the control of the control unit 600, the nozzle heater 68 heats the nozzle 61 and heats the plasticizing material in the nozzle channel 65.

[0034] The control unit 600 can adjust the fluidity of the plasticizing material in the nozzle channel 65 by controlling the output of the nozzle heater 68. The set temperature of the nozzle heater 68 is set to a higher temperature than the set temperature of the plasticizing heater 58 of the plasticizing unit 30 described above.

[0035] The discharge volume adjustment unit 70 adjusts the flow rate of the plasticizing material discharged from the nozzle opening 62. The flow rate of the plasticizing material discharged from the nozzle opening 62 to the outside is sometimes called the discharge volume. The discharge volume adjustment unit 70 is composed of a butterfly valve that changes the opening of the flow path 66 by rotating within the flow path 66, and is located in the supply flow path 67 of the flow path 66.

[0036] The discharge volume adjustment unit 70 is driven by a first drive unit 74, which is composed of a stepping motor or the like, under the control of the control unit 600. The control unit 600 adjusts the opening degree of the flow path 66 by controlling the rotation angle of the butterfly valve using the first drive unit 74.

[0037] This allows the control unit 600 to adjust the flow rate of the plasticizing material from the plasticizing unit 30 to the nozzle 61 and adjust the amount dispensed. The dispensed amount adjustment unit 70 can also set the dispensed amount to zero by setting the opening of the flow path 66 to zero. In other words, the dispensed amount adjustment unit 70 adjusts the dispensed amount and also controls the on / off of the dispensed plasticizing material.

[0038] The suction and discharge unit 75 is connected in the flow path 66 between the discharge amount adjustment unit 70 and the nozzle opening 62. The suction and discharge unit 75 performs a suction operation to draw in the plasticizing material in the flow path 66 and a discharge operation to push the drawn-in plasticizing material toward the nozzle opening 62.

[0039] The suction and discharge section 75 is composed of a plunger. In the suction operation described above, the plunger of the suction and discharge section 75 is retracted in a direction away from the flow path 66, and in the discharge operation, the plunger is advanced in a direction towards the flow path 66. The suction and discharge section 75 is driven by the second drive section 76 under the control of the control unit 600.

[0040] The second drive unit 76 is composed of, for example, a stepping motor or a rack and pinion mechanism that converts the rotational force of the stepping motor into translational motion of a plunger.

[0041] The control unit 600 suppresses the trailing phenomenon, where the plasticizing material hangs down in a string-like manner from the nozzle opening 62, by performing a suction operation using the suction discharge unit 75 when stopping the delivery of the plasticizing material from the nozzle 61.

[0042] In this case, the control unit 600 can more effectively suppress the trailing phenomenon by performing a suction operation after setting the opening of the flow path 66 to 0 using the discharge amount adjustment unit 70. In addition, the suction discharge unit 75 improves the responsiveness of the discharge of plasticizing material from the nozzle 61 by performing a discharge operation when starting or restarting the discharge of plasticizing material from the nozzle 61.

[0043] In this case, the control unit 600 can further improve the responsiveness of the plasticizing material delivery by performing a suction operation before the opening of the flow path 66 is increased to more than 0 by the delivery amount adjustment unit 70.

[0044] The stage 300 is positioned opposite the tip surface 63 of the nozzle 61. The three-dimensional molding apparatus 100 extrudes plasticizing material from the nozzle 61 toward the molding surface 311 of the stage 300, and creates a three-dimensional object by stacking layers of plasticizing material.

[0045] The position changing unit 400 changes the relative position between the nozzle 61 and the stage 300 by changing the relative position between the material delivery device 150 and the stage 300. The position changing unit 400 moves the stage 300 relative to the material delivery device 150.

[0046] Furthermore, the change in the relative position of the material delivery device 150 and nozzle 61 with respect to the stage 300 is sometimes simply referred to as the movement of the material delivery device 150 and nozzle 61. In other words, for example, moving the stage 300 in the +X direction can be rephrased as moving the material delivery device 150 and nozzle 61 in the -X direction.

[0047] The position change unit 400 is composed of a three-axis positioner that moves the stage 300 in the three axes of X, Y, and Z directions using the driving force of three motors. Each motor is driven under the control of the control unit 600. The position change unit 400 may be configured to move the material feeding device 150 without moving the stage 300, or it may be configured to move both the stage 300 and the material feeding device 150.

[0048] Next, the configuration of the pressure detection unit 200 will be explained with reference to Figure 4.

[0049] The pressure detection unit 200 includes a cylinder 210 connected to the flow path 66, a plunger pin 220 inserted into the cylinder 210, a transmission member 230 connected to the plunger pin 220, and a measuring unit 240 that measures the pressure of the plasticizing material in the flow path 66 via the plunger pin 220 and the transmission member 230.

[0050] The cylinder 210 has a cylindrical shape with its axial direction as its longitudinal direction. As shown in Figures 1 and 4, the cylinder 210 is positioned so that its longitudinal direction is along the X direction. As shown in Figure 1, the -X end of the cylinder 210 opens in the -X direction toward the flow path 66. The +X end of the cylinder 210 is located in the +X direction toward the flow path 66. The flow path 66 communicates with the outside of the flow path 66 in the X direction via the cylinder 210.

[0051] The cylinder 210 is connected downstream of the discharge volume adjustment unit 70 in the flow path 66 (see Figure 1). Furthermore, the cylinder 210 is connected downstream of the suction / discharge unit 75 in the flow path 66. However, the cylinder 210 may also be connected upstream of the suction / discharge unit 75 in the flow path 66.

[0052] The plunger pin 220 has an axial shape with its axial direction as its longitudinal direction. The plunger pin 220 is made of tool steel. As shown in Figures 1 and 4, the plunger pin 220 is inserted into the cylinder 210 such that its longitudinal direction is along the X direction.

[0053] The plunger pin 220 has a pin end face 221 and a transmission portion 222 that is further from the flow path 66 than the pin end face 221 in the X direction. The pin end face 221 is the end face of the plunger pin 220 in the -X direction. As shown in Figure 1, the pin end face 221 faces the flow path 66 inside the cylinder 210.

[0054] The transmission portion 222 is the end face of the plunger pin 220 opposite to the pin end face 221 in the longitudinal direction, and is the end face of the plunger pin 220 in the +X direction. The plunger pin 220 has a coupling portion 223 at its +X end, which has a larger diameter than the rest of the plunger pin 220 in the X direction. The transmission portion 222 is the end face of the coupling portion 223 in the +X direction. As shown in Figures 1 and 4, the transmission portion 222 is in contact with the transmission member 230 in the X direction at the +X position of the cylinder 210.

[0055] The gap between the side surface of the plunger pin 220 and the inner surface of the cylinder 210 is, for example, 50 μm or less, from the viewpoint of suppressing leakage of the plasticizing material in the flow path 66 to the outside through the gap between the plunger pin 220 and the cylinder 210.

[0056] As shown in Figures 1 and 4, the transmission member 230 is positioned between the plunger pin 220 and the measuring section 240 in the X direction. The transmission member 230 is made of stainless steel. The end face 231 of the transmission member 230 in the +X direction is in contact with the measuring section 240.

[0057] As shown in Figure 4, a recess 232 opening in the -X direction is formed at the -X end of the transmission member 230. The +X tip portion of the plunger pin 220 is inserted into the opening of the recess 232. Within the opening of the recess 232, the transmission portion 222 of the plunger pin 220 is in contact with the bottom portion 233 of the recess 232 in the X direction.

[0058] The plunger pin 220 and the transmission member 230 are connected by a joint 234 that covers the side surface of the -X end of the transmission member 230. The joint 234 has a shape that engages with the -X surface of the coupling portion 223 of the plunger pin 220, thereby restricting the movement of the plunger pin 220 relative to the transmission member 230 in the -X direction.

[0059] A gap Gp is ​​formed between the side surface of the coupling portion 223 of the plunger pin 220 and the inner surface of the recess 232. Therefore, the plunger pin 220 contacts the transmission member 230 in the X direction, but not in the Y or Z directions. A gap is also formed between the side surface of the plunger pin 220 and the coupling portion 223.

[0060] The plunger pin 220 transmits the pressure of the plasticizing material in the flow path 66 to the measuring unit 240. More specifically, the plunger pin 220 receives a force in the +X direction due to the pressure of the plasticizing material in the flow path 66 at its pin end face 221, and transmits it to the transmission member 230 via the transmission unit 222. The force transmitted to the transmission member 230 via the transmission unit 222 is then transmitted to the measuring unit 240 via the end face 231 of the transmission member 230. Hereafter, the force transmitted to the measuring unit 240 via the transmission unit 222 in this manner may also be referred to as the detected force.

[0061] The measuring unit 240 includes a motor 250 having an output shaft 251 and a torque member 260 connected to the output shaft 251.

[0062] The motor 250 is positioned with its output shaft 251 facing the -Z direction such that the output shaft 251 is aligned with the Z direction perpendicular to the longitudinal direction of the plunger pin 220. The motor 250 is a servo motor. The measuring unit 240 includes a controller 255 for servo-controlling the motor 250. The drive of the motor 250 is controlled by the control unit 600 via the controller 255.

[0063] The controller 255 performs position holding control by providing feedback control to maintain the rotational position of the output shaft 251. More specifically, when the motor 250 is stopped and an external torque is applied to the output shaft 251, the controller 255 restricts changes in the rotational position of the output shaft 251 by generating a torque in the opposite direction to that torque on the output shaft 251.

[0064] Furthermore, if the rotational position of the output shaft 251 changes due to an externally applied torque, the rotational position of the output shaft 251 is restored to its original position by similarly generating a torque in the opposite direction to that torque. This type of position holding control is sometimes called servo lock. In the following, the torque used to maintain the rotational position of the output shaft 251 in position holding control may also be referred to as position holding torque.

[0065] Next, the pressure detection method will be explained with reference to Figure 5.

[0066] As shown in Figure 5, the torque member 260 has a connecting portion 261 and a force receiving portion 270.

[0067] The connecting portion 261 is a substantially cylindrical member arranged along the Z direction. The connecting portion 261 has a connecting hole 262 for connecting the output shaft 251 of the motor 250 and a fixing hole 263 for fixing the force receiving portion 270.

[0068] The connection hole 262 opens in the +Z direction at the +Z end of the connection portion 261 (see Figure 4). The fixing hole 263 opens in the -Z direction at the -Z end of the connection portion 261. In Figure 5, the positions of the connection hole 262 in the X and Y directions are shown by dashed lines, and similarly, the positions of the fixing hole 263 are shown by dashed lines.

[0069] The connection hole 262 is formed in the center of the connection portion 261 when viewed along the Z direction. The fixing hole 263 is formed at a position offset from the center of the connection portion 261 when viewed along the Z direction. Therefore, the fixing hole 263 is located at a position offset from the rotation axis RX of the output shaft 251 when viewed along the Z direction.

[0070] As shown in Figures 5 and 8, the force-receiving section 270 is composed of a cam follower and has a shaft 271 and an outer ring 272. The +Z end of the shaft 271 is inserted into the fixing hole 263 of the connecting section 261 described above. The outer ring 272 is supported by a bearing 273 fixed to the side of the shaft 271 so as to be rotatable in place around the shaft 271. The outer ring 272 and the bearing 273 are arranged in the -Z direction of the connecting section 261.

[0071] The fixing hole 263 is formed at a position offset from the rotation axis RX. Therefore, as shown in Figure 5, the force receiving portion 270 is positioned offset from the rotation axis RX when viewed along the Z direction. More specifically, the force receiving portion 270 is positioned at a distance L in the +Y direction from the rotation axis RX when viewed along the Z direction.

[0072] The torque member 260 receives the detection force described above and applies torque to the output shaft 251 based on the detection force. The torque member 260 receives the detection force through the outer ring 272 of the force receiving part 270, generating a rotational force that rotates the connecting part 261 connected to the output shaft 251, and applies torque generated by this rotational force to the output shaft 251. Hereinafter, the torque generated by the detection force and applied to the output shaft 251 may be referred to as the detection torque.

[0073] The measuring unit 240 detects the pressure of the plasticizing material in the flow path 66 based on the current or voltage value of the motor 250 generated by the detected torque applied to the output shaft 251. More specifically, while the controller 255 described above is performing position holding control, the measuring unit 240 detects a voltage value for generating a position holding torque corresponding to the detected torque, and detects the pressure of the plasticizing material in the flow path 66 based on the detected voltage value. In this way, the measuring unit 240 can detect the pressure while restricting the movement of the plunger pin 220 and the transmission member 230 in the +X direction.

[0074] Next, the specific configurations of the pressure detection unit 200 and the pressure generation unit 500 will be described with reference to Figures 6 to 11.

[0075] As shown in Figures 6 to 8, the pressure detection unit 200 detects the pressure in at least a portion of the flow path 66 (see Figure 1), as described above. The pressure generating unit 500 (see Figure 6) is connected to the pressure detection unit 200 and generates pressure.

[0076] Specifically, the pressure detection unit 200 includes a cylinder 210 (see Figure 7) connected to a flow path 66, a plunger pin 220 slidably positioned inside the cylinder 210, a transmission member 230 connected to the plunger pin 220 on the side opposite to the flow path 66, a measuring unit 240 connected via the transmission member 230 to measure the pressure received by the plunger pin 220 from the plasticizing material, and a housing 550 that holds the cylinder 210.

[0077] As shown in Figures 9, 10, and 11, the pressure generating unit 500 includes a spring 510 and a main body 520 including a first engaging portion 530 for connecting one end of the spring 510. The pressure detecting unit 200 has a second engaging portion 540 for connecting the other end of the spring 510.

[0078] As shown in Figure 11, the main body 520 has a plate portion 521 that extends in a direction along the molding surface 311 (see Figure 1) where the plasticizing material is extruded and a three-dimensional object is formed, and two support portions 522 that protrude along the plate portion 521.

[0079] Specifically, the main body portion 520 has a first portion 523 connected to the plate portion 521 at approximately a right angle to its extending direction. The first portion 523 is bent along the X direction. The first portion 523 is provided with a first engaging portion 530 to which one end of the spring 510 is connected. More specifically, the first engaging portion 530 is a groove for hooking the spring 510. The main body portion 520 is provided with two first portions 523, each equipped with a first engaging portion 530.

[0080] Furthermore, as shown in Figure 9, the two support portions 522 are positioned in contact with the upper part 551 of the housing 550. Therefore, when connecting the spring 510 to the first engaging portion 530 and the second engaging portion 540, the support portions 522 are supported in contact with the upper part 551 of the housing 550, allowing the spring 510 to be connected stably.

[0081] Furthermore, the main body portion 520 has a second portion 524 connected to the plate portion 521 at approximately a right angle to its extending direction. The second portion 524 is bent along the Y direction. The second portion 524 is provided with a groove 524a that engages with the plunger pin 220.

[0082] In this way, by replacing the pressure of the plasticizing material with the spring 510, it becomes possible to detect the pressure of the plasticizing material based on the current value or voltage value of the motor 250 of the measuring unit 240 without discharging the plasticizing material.

[0083] Next, the measurement method of the three-dimensional molding apparatus 100 will be explained with reference to Figures 12 to 15.

[0084] As shown in Figure 12, first, in step S11, the pressure detection unit 200 is cleaned, i.e., maintained. This maintenance is necessary because when the three-dimensional molding device 100 is in use, the plasticizing material can solidify, causing deterioration in the operation of the plunger pin 220 that slides inside the cylinder 210.

[0085] In step S12 (first pressure measurement step), the theoretical pressure is determined. This theoretical pressure is referred to as the first pressure data. Here, the pressure applied to the plasticizing material is replaced by the spring 510 that constitutes the pressure generating unit 500, and the pressure on the plasticizing material is calculated from the spring constant.

[0086] In step S13 (second pressure measurement step), the pressure of the plasticizing material is determined using the plunger pin 220. Here, the pressure applied to the plasticizing material is replaced with the spring 510 used in step S12, thereby simulating the pressure applied to the plasticizing material. In other words, the pressure generated by biasing the plunger pin 220 inside the cylinder 210 using the spring 510 is determined without discharging the plasticizing material. The pressure measured in this step is referred to as the second pressure data.

[0087] Specifically, as shown in Figures 13 and 14, the plunger pin 220 is fitted into the groove 524a of the main body 520, one end of the spring 510 is hooked onto the main body 520, and the other end of the spring 510 is hooked onto the housing 560, thereby allowing the pressure to be determined in the measuring unit 240. Note that the spring 510 is not shown in Figure 14. Furthermore, when the spring 510 is connected to the first engaging portion 530 and the second engaging portion 540, the two support portions 522 are positioned in contact with the upper part 551 of the housing 550.

[0088] In step S14 (third pressure measurement step), the difference between the first pressure data and the second pressure data is measured. Specifically, the difference between the first pressure data measured in the first pressure measurement step, i.e., the theoretical value of the pressure obtained from the spring constant etc. without using the plunger pin 220, and the second pressure data measured in the second pressure measurement step, i.e., the actual value measured using the plunger pin 220 without dispensing the plasticizing material, is measured. This makes it possible to confirm whether the measurement unit 240 is accurately measuring the pressure. In other words, it is possible to determine whether the pressure detection unit 200 is in a state where it can measure normally.

[0089] For example, if there is no difference between the first pressure data and the second pressure data, it can be determined that the maintenance was performed successfully. On the other hand, if there is a difference between the first pressure data and the second pressure data, it can be determined that the maintenance was not performed successfully, and the maintenance should be performed again.

[0090] Figure 15 shows thrust (N) and pressure (N / mm²). 2 The graph shows the relationship between the theoretical value (1st pressure data) and the PPL detection pressure, i.e., the measured value (2nd pressure data), by comparing them.

[0091] In step S11, if maintenance is performed correctly, the first pressure data and the second pressure data will show nearly identical values, as shown in Figure 15. If the values ​​differ significantly from this graph, it can be determined that maintenance has not been performed correctly.

[0092] Thus, it is preferable to have a cleaning step in which the pressure detection unit 200 is cleaned before the second pressure measurement step. With this method, the second pressure measurement step is performed after cleaning the pressure detection unit 200, specifically the cylinder 210 and plunger pin 220 to which the plasticizing material tends to adhere, so it is possible to determine whether or not the maintenance has been performed properly.

[0093] Furthermore, since the first and second pressure measurement steps generate pressure by connecting the spring 510 to the first engagement portion 530 and the second engagement portion 540, pressure can be generated with a relatively simple configuration.

[0094] Furthermore, since the plunger pin 220 is fitted into the groove 524a, pressure can be generated with a relatively simple configuration.

[0095] As described above, the measurement method of the three-dimensional molding apparatus 100 comprises a flow path 66 through which a plasticizing material heated and plasticized flows, a nozzle 61 communicating with the flow path 66 and sending the plasticizing material to the outside, a pressure detection unit 200 that detects the pressure of at least a part of the flow path 66, and a pressure generating unit 500 connected to the pressure detection unit 200 and generating pressure. The pressure detection unit 200 comprises a cylinder 210 connected to the flow path 66, a plunger pin 220 slidably arranged inside the cylinder 210, and the opposite side of the plunger pin 220 from the flow path 66. A measurement method for a three-dimensional molding apparatus 100, which includes a transmission member 230 connected to a pressure generating unit 500 and a measuring unit 240 connected via the transmission member 230 for measuring the pressure received by the plunger pin 220 from the plasticizing material, comprising: a first pressure measurement step of measuring the pressure of the pressure generating unit 500 as first pressure data; a second pressure measurement step of the measuring unit 240 measuring the pressure generated by the pressure generating unit 500 biasing the plunger pin 220 as second pressure data; and a third pressure measurement step of measuring the difference between the first pressure data and the second pressure data.

[0096] According to this method, the difference between the first pressure data measured in the first pressure measurement step (i.e., the theoretical value of the pressure obtained from the spring constant etc. without using the plunger pin 220) and the second pressure data measured in the second pressure measurement step (i.e., the actual value measured using the plunger pin 220 without dispensing the plasticizing material) is measured, so it is possible to confirm whether the measuring unit 240 is accurately measuring the pressure. Therefore, it is possible to determine whether the pressure detection unit 200 is in a state where it can measure normally.

[0097] Furthermore, since the theoretical first pressure data and the measured second pressure data are equivalent, it can be determined that there is no sticking due to plasticizing material in the plunger pin 220 inside the cylinder 210 and that there is no mechanical loss.

[0098] Furthermore, in the measurement method of the three-dimensional molding apparatus 100 of this embodiment, it is preferable to have a cleaning step in which the pressure detection unit 200 is cleaned before the second pressure measurement step. With this method, the second pressure measurement step is performed after cleaning the pressure detection unit 200, specifically the cylinder 210 and plunger pin 220 to which the plasticizing material tends to adhere, so it is possible to determine whether or not maintenance has been performed properly.

[0099] Furthermore, in the measurement method of the three-dimensional molding apparatus 100 of this embodiment, the pressure generating unit 500 has a spring 510 and a main body 520 including a first engaging part 530 for connecting one end of the spring 510, and the pressure detection unit 200 has a second engaging part 540 for connecting the other end of the spring 510 opposite to the one end, and it is preferable that the second pressure measurement step generates pressure by connecting the spring 510 to the first engaging part 530 and the second engaging part 540. With this method, since a spring 510 is used, pressure can be generated with a relatively simple configuration.

[0100] Furthermore, in the measurement method of the three-dimensional molding apparatus 100 of this embodiment, the main body 520 has a plate portion 521 that extends in a direction along the molding surface 311 on which the plasticizing material is extruded and a three-dimensional molded object is formed, and a support portion 522 that protrudes along the plate portion 521, the pressure detection unit 200 has a housing 550 that holds the cylinder 210, and in the second pressure measurement step, it is preferable that the support portion 522 contacts the upper part 551 of the housing 550 when the spring 510 is connected to the first engagement portion 530 and the second engagement portion 540. With this method, since the support portion 522 contacts the upper part 551 of the housing 550, it becomes possible to support the support portion 522 and stably connect the spring 510.

[0101] Furthermore, in the measurement method of the three-dimensional molding apparatus 100 of this embodiment, the first engagement portion 530 is formed on the first portion 523 connected at approximately a right angle to the extending direction of the plate portion 521, and in the second pressure measurement step, it is preferable that the spring 510 generates pressure by connecting the first engagement portion 530 and the second engagement portion 540. With this method, since the first engagement portion 530 is formed on the portion that is bent at a right angle to the plate portion 521, it is easy to set the spring 510 on the first engagement portion 530 and the second engagement portion 540, in other words, it is easy to hook it.

[0102] Furthermore, in the measurement method of the three-dimensional molding apparatus 100 of this embodiment, the main body portion 520 has a second portion 524 that contacts the plunger pin 220 and is connected substantially perpendicular to the extending direction of the plate portion 521, and the second portion 524 is provided with a groove portion 524a that fits with the plunger pin 220, and in the second pressure measurement step, it is preferable that pressure is generated by fixing the groove portion 524a to the plunger pin 220. With this method, since the plunger pin 220 is fitted into the groove portion 524a, pressure can be generated with a relatively simple configuration.

[0103] The following describes some variations of the embodiments described above.

[0104] As described above, the spring 510 is not limited to being of one type, and multiple springs 510 with different spring constants may be used. [Explanation of symbols]

[0105] 20...Material supply unit, 22...Supply path, 30...Plasticizing unit, 31...Screw case, 32...Drive motor, 40...Screw, 41...Top surface, 42...Groove forming surface, 43...Side surface, 44...Material inlet, 45...Groove, 46...Convex part, 47...Center part, 50...Barrel, 52...Screw opposing surface, 54...Guide groove, 56...Communication hole, 58...Plasticizing heater, 61...Nozzle, 62...Nozzle opening, 63...Tip surface, 65...Nozzle flow path, 66...Flow path, 67...Supply flow path, 68...Nozzle heater, 70...Discharge amount adjustment unit, 74...First drive unit, 75...Suction discharge unit, 76...Second drive unit, 100...Three-dimensional molding device, 150...Material delivery device, 200...Pressure detection unit, 210...Cylinder, 220...Plunger pin, 2 21...Pin end face, 222...Transmission part, 223...Coupling part, 230...Transmission member, 231...End face, 232...Recess, 233...Bottom, 234...Joint, 240...Measurement part, 250...Motor, 251...Output shaft, 255...Controller, 260...Torque member, 261...Connection part, 262...Connection hole, 263...Fixing hole, 270...Force receiving part, 271...Shaft, 272 ...outer ring, 273...bearing, 300...stage, 311...molding surface, 400...position change section, 500...pressure generating section, 520...main body section, 521...plate section, 522...support section, 523...first section, 524...second section, 524a...groove section, 530...first engaging section, 540...second engaging section, 550...housing, 551...upper section, 560...housing, 600...control section.

Claims

1. A channel through which a plasticized material, which has been plasticized by heat, flows, A nozzle that communicates with the aforementioned flow path and delivers the plasticizing material to the outside, A pressure detection unit that detects the pressure of at least a portion of the flow path, A pressure generating unit connected to the pressure detection unit generates pressure, Equipped with, The pressure detection unit is A cylinder connected to the aforementioned flow path, A plunger pin is slidably positioned inside the cylinder, A transmission member connected to the opposite side of the flow path in the plunger pin, A measuring unit connected via the aforementioned transmission member, which measures the pressure the plunger pin receives from the plasticizing material, A measurement method for a three-dimensional molding apparatus, comprising: A first pressure measurement step in which the pressure of the pressure generating unit is measured as first pressure data, A second pressure measurement step in which the measuring unit measures the pressure generated by the pressure generating unit biasing the plunger pin as second pressure data, A third pressure measurement step for measuring the difference between the first pressure data and the second pressure data, A measurement method for a three-dimensional molding apparatus.

2. A method for measuring a three-dimensional molding apparatus according to claim 1, A measurement method for a three-dimensional molding apparatus, comprising a cleaning step of cleaning the pressure detection unit before the second pressure measurement step.

3. A method for measuring a three-dimensional molding apparatus according to claim 1, The pressure generating unit comprises a spring and a main body including a first engaging portion for connecting one end of the spring. The pressure detection unit has a second engagement portion for connecting the other end of the spring opposite to the one end, The second pressure measurement step is a measurement method for a three-dimensional molding apparatus, wherein the spring is connected to the first engagement portion and the second engagement portion to generate the pressure.

4. A method for measuring a three-dimensional molding apparatus according to claim 3, The main body comprises a plate portion extending in a direction along the molding surface from which the plasticizing material is extruded and a three-dimensional object is formed, and a support portion protruding along the plate portion. The pressure detection unit has a housing that holds the cylinder, The second pressure measurement step is a measurement method for a three-dimensional molding apparatus, wherein the support portion contacts the upper part of the housing when the spring is connected to the first engagement portion and the second engagement portion.

5. A method for measuring a three-dimensional molding apparatus according to claim 4, The first engaging portion is formed in a first portion connected to the plate portion at a substantially right angle to the extending direction, The second pressure measurement step is a measurement method for a three-dimensional molding apparatus, wherein the spring generates the pressure by connecting the first engagement portion and the second engagement portion.

6. A method for measuring a three-dimensional molding apparatus according to claim 5, The main body portion has a second portion that contacts the plunger pin and is connected to the plate portion at a substantially right angle to the extending direction, The second portion is provided with a groove that engages with the plunger pin, The second pressure measurement step is a measurement method for a three-dimensional molding apparatus, wherein the groove portion is fixed to the plunger pin to generate the pressure.

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