Material supply device, three-dimensional forming device, and injection molding device

Abstract

To provide a technology capable of measuring backlash without disassembling the device.SOLUTION: The material supply device comprises a plasticizing section that plasticizes material to generate plasticized material, a nozzle that supplies the plasticized material to the outside, a supply control mechanism that is installed in a flow path connecting the plasticizing section and the nozzle and that adjusts the supply amount of the plasticized material from the nozzle to the outside, a pressure sensor that measures the pressure of the plasticized material within the flow path, and a control unit that controls the operation of the supply control mechanism. The control unit calculates a backlash value representing the backlash of the supply control mechanism based on detection data including the detection value output from the pressure sensor. The detection data is data containing, in time series, detection values output from the pressure sensor during at least one portion of either the period spanning the first operation, which reduces the supply amount of the plasticized material from the nozzle by the supply control mechanism, or the period spanning the second operation, which increases the supply amount of the plasticized material from the nozzle.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a material supplying device, a three-dimensional modeling device, and an injection molding device. [Background technology]

[0002] The three-dimensional modeling apparatus disclosed in Patent Document 1 is provided with a flow rate adjusting mechanism that adjusts the amount of plasticizing material discharged from a discharge portion. [Prior art documents] [Patent documents]

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

[0004] Backlash exists in the mechanical parts that make up the flow control mechanism, and it has traditionally been difficult to measure backlash without disassembling the device. [Means for solving the problem]

[0005] According to a first aspect of the present disclosure, there is provided a material supply device including: a plasticizing unit that plasticizes a material to produce a plasticized material; a nozzle that supplies the plasticized material to an outside; a supply control mechanism provided in a flow path communicating with the plasticizing unit and the nozzle and that adjusts the amount of the plasticized material supplied from the nozzle to the outside; a pressure sensor that measures the pressure of the plasticized material in the flow path; and a controller that controls the operation of the supply control mechanism, wherein the controller calculates a backlash value representing backlash of the supply control mechanism based on detection data including detection values ​​output from the pressure sensor, and the detection data includes the detection values ​​output from the pressure sensor in time series during at least a portion of a period during which the supply control mechanism performs a first operation to reduce the amount of the plasticized material supplied from the nozzle and a period during which the supply control mechanism performs a second operation to increase the amount of the plasticized material supplied from the nozzle.

[0006] According to a second aspect of the present disclosure, there is provided a three-dimensional modeling apparatus including the material supply device described above and a stage onto which the plasticizable material is supplied from the material supply device and deposited.

[0007] According to a third aspect of the present disclosure, there is provided an injection molding apparatus comprising the above-mentioned material supply device and a clamping device that opens and closes a molding die having a cavity to which the plasticized material is supplied from the material supply device. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is an explanatory diagram illustrating a schematic configuration of a three-dimensional modeling apparatus. [Figure 2] FIG. 1 is an explanatory diagram illustrating a schematic configuration of a three-dimensional modeling apparatus. [Figure 3] FIG. 2 is a perspective view showing a schematic configuration of a screw. [Figure 4] FIG. 2 is a schematic plan view of the barrel. [Figure 5] FIG. 2 is a perspective view of a movable part and a material supply device. [Figure 6] FIG. [Figure 7] FIG. 3 is a cross-sectional view showing the configuration of a suction delivery section and a pressure sensor. [Figure 8] FIG. 10 is an explanatory diagram of the operation of the plunger. [Figure 9] FIG. 2 is an enlarged cross-sectional view of a portion of the plunger. [Figure 10] 10 is a flowchart of a three-dimensional modeling process. [Figure 11] FIG. 10 is a diagram illustrating a method for calculating backlash. [Figure 12] FIG. 10 is a diagram illustrating a method for calculating backlash. [Figure 13] FIG. 10 is a diagram illustrating a method for calculating backlash in the second embodiment. [Figure 14] FIG. 10 is a diagram illustrating a method for calculating backlash in the second embodiment. [Figure 15] FIG. 10 is a diagram illustrating a method for calculating backlash in the third embodiment. [Figure 16] FIG. 10 is a diagram illustrating a method for calculating backlash in the fourth embodiment. [Figure 17] FIG. 10 is an explanatory view showing a schematic configuration of an injection molding apparatus according to a fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] A. First embodiment: 1 and 2 are explanatory diagrams showing a schematic configuration of a three-dimensional printing apparatus 100 according to a first embodiment. Arrows representing mutually orthogonal X, Y, and Z directions are shown in FIGS. 1 and 2. The X and Y directions are parallel to a horizontal plane. The Z direction is parallel to the vertical direction. The X, Y, and Z directions in FIGS. 1 and 2 and the X, Y, and Z directions in other figures indicate the same directions. When specifying a direction, positive and negative signs are used in combination to indicate the direction indicated by the arrow, with "+" indicating the positive direction and "-" indicating the negative direction opposite to the direction indicated by the arrow. The Z direction corresponds to the "first direction."

[0010] The three-dimensional modeling apparatus 100 includes a material supplying device 10, a stage 20, a position changing unit 30, a first heating unit 40, and a control unit 50.

[0011] The control unit 50 controls each unit of the 3D printing apparatus 100. The control unit 50 is configured by a computer having one or more processors 51, a storage unit 52 including a main storage unit and an auxiliary storage unit, and an input / output interface for inputting and outputting signals to and from the outside. The processor 51 executes the 3D printing process described below in accordance with a program stored in the storage unit 52. Note that instead of being configured by a computer, the control unit 50 may be realized by a configuration combining multiple circuits for realizing at least some of the functions.

[0012] Under the control of the control unit 50, the material supplying device 10 supplies and deposits a plasticized material, which is a paste-like plasticized material obtained by plasticizing a solid material, onto a stage 20 that serves as a base for the three-dimensional object. The material supplying device 10 includes a raw material supplying unit 11, a plasticizing unit 12, and a nozzle 13. The material supplying device 10 is also referred to as a head.

[0013] The three-dimensional modeling apparatus 100 includes a first material supply device 10a and a second material supply device 10b as material supply devices 10. The first material supply device 10a includes a first material supply unit 11a as the raw material supply section 11, a first plasticizing unit 12a as the plasticizing unit 12, and a first nozzle 13a as the nozzle 13. The second material supply device 10b includes a second material supply unit 11b as the raw material supply section 11, a second plasticizing unit 12b as the plasticizing unit 12, and a second nozzle 13b as the nozzle 13. The first material supply device 10a and the second material supply device 10b are arranged side by side in the X direction so that their positions in the Y direction are the same. The second material supply device 10b is arranged in a position in the +X direction from the first material supply device 10a. The first material supply device 10a and the second material supply device 10b have the same configuration, and therefore, hereinafter, when there is no particular need to distinguish between them, they may be simply referred to as material supply devices 10. When distinguishing between the components of the first material supply device 10a and the second material supply device 10b, the components of the first material supply device 10a are denoted by the symbol "a," and the components of the second material supply device 10b are denoted by the symbol "b."

[0014] The raw material supply unit 11 supplies raw materials for producing a plasticized material to the plasticizing unit 12. The raw material supply unit 11 is configured, for example, by a hopper. The raw material supply unit 11 stores raw materials in pellet or powder form. For example, thermoplastic resins such as polypropylene resin (PP), polyethylene resin (PE), and polyacetal resin (POM) are used as the raw materials. A communication passage 15 is provided below the raw material supply unit 11, connecting the raw material supply unit 11 and the plasticizing unit 12. The raw material supply unit 11 supplies raw materials to the plasticizing unit 12 via the communication passage 15.

[0015] The plasticizing unit 12 plasticizes at least a portion of the raw material supplied from the raw material supply unit 11 to produce a fluid, paste-like plasticized material, which is then introduced into the nozzle 13. Here, "plasticization" is a concept that includes melting, and refers to changing a material from a solid to a fluid state. Specifically, for materials that undergo glass transition, plasticization refers to raising the temperature of the material above the glass transition point. For materials that do not undergo glass transition, plasticization refers to raising the temperature of the material above the melting point.

[0016] The plasticizing section 12 includes a screw 110 , a screw drive motor 120 , a barrel 130 , and a discharge section 140 .

[0017] As shown in FIG. 2 , the screw 110 is housed in a lower case 152. The upper surface of the screw 110 is connected to a screw drive motor 120 via a drive shaft 121. The screw 110 rotates integrally with the drive shaft 121 when the screw drive motor 120 applies a driving force to the drive shaft 121. The rotation axis RX of the screw 110 coincides with the axis of the drive shaft 121. The axial direction of the rotation axis RX of the screw 110 is along the Z direction. The rotation speed of the screw 110 is controlled by the control unit 50 controlling the rotation speed of the screw drive motor 120. The screw 110 may be driven by the screw drive motor 120 via a reducer. The screw 110 is also called a rotor or a flat screw. The drive shaft 121 is provided in an upper case 151 located above the lower case 152.

[0018] The barrel 130 is installed on the -Z direction side of the screw 110. An opposing surface 131, which is the upper surface of the barrel 130, faces a groove forming surface 111, which is the lower surface of the screw 110. A communication hole 132, which communicates with a flow path 142 of the discharge section 140, is formed in the center of the barrel 130. A second heating section 201, which heats the material supplied to the groove 113 of the screw 110, which will be described later, is housed inside the barrel 130. Details of the barrel 130 will be described later.

[0019] FIG. 3 is a perspective view showing a schematic configuration of the screw 110. The screw 110 has a generally cylindrical shape whose length in the direction along the rotation axis RX is shorter than its length in the direction perpendicular to the rotation axis RX. A spiral groove 113 is formed on the groove-forming surface 111, with a central portion 112 as the center. The groove 113 communicates with an inlet 114 formed on the side surface of the screw 110. The raw material supplied from the raw material supply unit 11 is supplied to the groove 113 through the inlet 114. The grooves 113 are formed by being separated by ridge portions 115. FIG. 3 shows an example in which three grooves 113 are formed, but the number of grooves 113 may be one or two or more. Note that the groove 113 is not limited to a spiral shape, and may be a spiral shape or an involute curve shape, or may have a shape extending in an arc from the central portion 112 to the outer periphery.

[0020] 4 is a schematic plan view of barrel 130. A plurality of guide grooves 133 are formed around communicating hole 132 in opposing surface 131. One end of each guide groove 133 is connected to communicating hole 132, and extends in a spiral shape from communicating hole 132 toward the outer periphery of opposing surface 131. Note that one end of guide groove 133 does not have to be connected to communicating hole 132. Furthermore, barrel 130 does not necessarily have to have guide grooves 133 formed therein.

[0021] The raw material supplied to the groove 113 of the screw 110 is plasticized within the groove 113 by the rotation of the screw 110 and heating by the second heating section 201, and flows along the groove 113, and is guided to the central section 112 of the screw 110 as a plasticized material. The paste-like plasticized material that has flowed into the central section 112 and exhibits fluidity is supplied to the discharge section 140 via the communicating holes 132. Note that not all types of substances that make up the plasticized material need to be plasticized in the plasticizing section. It is sufficient that the plasticized material is converted into a state that has fluidity as a whole by plasticizing at least some types of substances that make up the plasticized material.

[0022] 2 includes a flow path block 141, a supply control mechanism 148, and a pressure sensor 170. The supply control mechanism 148 is provided in a flow path 142 that communicates with the plasticizing unit 12 and the nozzle 13, and adjusts the amount of plasticizing material supplied from the nozzle 13 to the outside of the nozzle 13. The supply control mechanism 148 includes a flow rate adjustment unit 143 and a suction delivery unit 160.

[0023] The flow path block 141 is installed on the −Z direction side of the barrel 130. A flow path 142 is formed in the flow path block 141. A third heating unit 203 that heats the flow path block 141 is housed inside the flow path block 141.

[0024] The nozzle 13 is provided at the lower end of the flow path block 141. The nozzle 13 is connected to the communication hole 132 of the barrel 130 through the flow path 142. The nozzle 13 discharges the plasticized material produced in the plasticizing section 12 from the discharge port 145 at the tip of the nozzle 13 toward the stage 20.

[0025] The flow rate adjustment unit 143 includes a valve disposed in the flow path 142. The flow rate adjustment unit 143 is controlled by the control unit 50. The control unit 50 controls the rotation angle of the valve to change the opening of the flow path 142, thereby adjusting the flow rate of the plasticizing material flowing from the plasticizing unit 12 to the nozzle 13, i.e., the flow rate of the plasticizing material supplied to the outside from the nozzle 13. The flow rate adjustment unit 143 adjusts the flow rate of the plasticizing material and also controls the on / off flow of the plasticizing material. The flow rate adjustment unit 143 may also have a shutter mechanism and adjust the flow rate of the plasticizing material by changing the opening of the flow path 142 using the shutter mechanism.

[0026] The suction and delivery unit 160 is a mechanism for performing a first operation of reducing the supply amount of plasticized material from the nozzle 13 by sucking the plasticized material from the flow path 142, and a second operation of increasing the supply amount of plasticized material from the nozzle 13 by delivering the sucked plasticized material to the flow path 142. By performing the first operation, it is possible to suppress the tailing phenomenon in which the plasticized material hangs like a string from the nozzle 13. Furthermore, by performing the second operation, it is possible to improve the responsiveness of the delivery of the plasticized material from the nozzle 13. The suction and delivery unit 160 is controlled by the control unit 50. The specific configuration of the suction and delivery unit 160 will be described later.

[0027] When the control unit 50 stops the discharge of the plasticized material from the nozzle 13, it first controls the flow rate adjustment unit 143 to turn off the outflow of the plasticized material, and then controls the suction and delivery unit 160 to perform a first operation to suck the plasticized material from the flow path 142. When the control unit 50 resumes the discharge of the plasticized material from the nozzle 13, it controls the suction and delivery unit 160 to perform a second operation to send the plasticized material sucked by the suction and delivery unit 160 to the flow path 142, and then controls the flow rate adjustment unit 143 to turn on the outflow of the plasticized material. In addition, just before changing the movement direction of the nozzle 13, the control unit 50 controls the suction and delivery unit 160 to perform the first operation while slowing down the movement speed of the nozzle 13, thereby preventing the line width of the plasticized material from becoming wider as the movement speed decreases. Immediately after changing the movement direction of the nozzle 13, the control unit 50 increases the reduced movement speed of the nozzle 13 while controlling the suction and delivery unit 160 to perform the second operation, thereby preventing the line width of the plasticized material from becoming thinner as the movement speed increases.

[0028] The pressure sensor 170 is used to measure the pressure of the plasticized material in the flow path 142. The control unit 50 uses the pressure sensor 170 to measure the pressure of the plasticized material in the flow path 142. The specific configuration of the pressure sensor 170 will be described later.

[0029] The stage 20 is disposed at a position facing the discharge port 145 of the nozzle 13. The three-dimensional modeling device 100 discharges a plasticized material from the nozzle 13 toward the modeling surface 21 of the stage 20 to stack modeling layers, thereby forming a three-dimensional object.

[0030] The position changer 30 changes the relative position between the nozzle 13 and the stage 20. In this embodiment, the position changer 30 changes the relative position between the nozzle 13 and the stage 20 by moving the material supply device 10 along the Z direction, which is the stacking direction of the modeling layers, and by moving the stage 20 in a direction intersecting the stacking direction. More specifically, in this embodiment, the position changer 30 moves the material supply device 10 along the Z direction to change the relative position between the nozzle 13 and the stage 20 in the Z direction, and moves the stage 20 in the X direction and the Y direction to change the relative positions between the nozzle 13 and the stage 20 in the X direction and the Y direction. As shown in FIG. 1 , the position changer 30 is composed of a first electric actuator 31 that moves the stage 20 along the X direction, a second electric actuator 32 that moves the stage 20 and the first electric actuator 31 along the Y direction, and a third electric actuator 33 that moves the material supply device 10 along the Z direction. The third electric actuator 33 moves a movable part 41 to which the first material supply device 10a and the second material supply device 10b are fixed along the Z direction, thereby moving the first material supply device 10a and the second material supply device 10b along the Z direction. Note that the third electric actuator 33 and the movable part 41 are omitted from Fig. 2.

[0031] The first electric actuator 31, the second electric actuator 32, and the third electric actuator 33 described above are driven under the control of the control unit 50. Note that the position change unit 30 may, for example, move the stage 20 in the Z direction and move the material supply device 10 along the X and Y directions, or may move the stage 20 in the X, Y, and Z directions without moving the material supply device 10, or may move the material supply device 10 in the X, Y, and Z directions without moving the stage 20.

[0032] The first heating unit 40 is a plate-shaped heater that heats the plasticized material layered on the stage 20. The first heating unit 40 is fixed to a movable unit 41. The first heating unit 40 is moved in the Z direction together with the material supply device 10 by a third electric actuator 33. As shown in FIG. 2, the first heating unit 40 has an opening 42 that penetrates in the Z direction. When the nozzle 13 is ejecting the plasticized material to form a three-dimensional object, the nozzle 13 is positioned within the opening 42, and the tip of the nozzle 13 is positioned between the first heating unit 40 and the stage 20 in the Z direction.

[0033] Fig. 5 is a perspective view of the movable part 41 and the material supply device 10. Fig. 5 shows a state in which the upper case 151 of the three-dimensional printing apparatus 100 is separated from the lower case 152. The upper case 151 can be separated from the lower case 152 during maintenance of the three-dimensional printing apparatus 100, etc. A support part 211 is fixed to the movable part 41. The support part 211 is configured to be able to suspend the upper case 151 when the upper case 151 is separated from the lower case 152.

[0034] FIG. 6 is a side view of the material supply apparatus 10. As described above, the material supply apparatus 10 includes the suction and delivery unit 160 and the pressure sensor 170. A first motor support member 180 and a second motor support member 184 are fixed to the side surface of the upper case 151 on the -Y direction side. The first motor support member 180 supports the first motor 161, which serves as a drive unit for driving the suction and delivery unit 160. The second motor support member 184 supports the second motor 171, which is used to operate the pressure sensor 170. The first motor support member 180 and the second motor support member 184 fix the first motor 161 and the second motor 171 to the upper case 151. The rotation axis RX1 of the first motor 161 and the rotation axis RX2 of the second motor 171 are aligned in the Z direction. A flow rate adjustment motor 181 for rotating a valve provided in the flow rate adjustment unit 143 is provided on the opposite side of the suction and delivery unit 160 and the pressure sensor 170 across the upper case 151 and the lower case 152. In addition to the valve, the flow rate adjustment unit 143 is provided with this flow rate adjustment motor 181 and a coupling 144 for transmitting the rotational force of the flow rate adjustment motor 181 to the valve.

[0035] FIG. 7 is a cross-sectional view showing the configuration of the suction and delivery unit 160 and the pressure sensor 170. The suction and delivery unit 160 has a first cylinder 162 and a plunger 163. The first cylinder 162 is connected to the flow path 142 through which the plasticizable material flows. In this embodiment, the first cylinder 162 is connected to the flow path 142 downstream of the flow rate adjuster 143. The first cylinder 162 is disposed along the Y direction, which is perpendicular to the direction in which the flow path 142 extends. The plunger 163 slides within the first cylinder 162. The tip of the plunger 163 is disposed within the first cylinder 162, and the rear end of the plunger 163 is located near the bottom of the first motor 161. The plunger 163 is configured by fastening a tip member 193 and a rear end member 194 with a fastening member 195.

[0036] The first drive shaft 164 of the first motor 161 has a first connection portion 165 that is eccentric with respect to the rotation axis RX1 of the first drive shaft 164. The first connection portion 165 is formed by, for example, a cam follower or a roller follower. The plunger 163 has an engagement portion 166 at its rear end. The engagement portion 166 is fixed to a rear end member 194 of the plunger 163 by a bolt 199. The engagement portion 166 is recessed along the Z direction and has a recess 167 with which the first connection portion 165 engages. The first connection portion 165 and the engagement portion 166 form a conversion mechanism 168 that converts the rotational motion of the first motor 161 into linear motion of the plunger 163. This conversion mechanism 168 is also called a Scotch yoke mechanism.

[0037] Fig. 8 is an explanatory diagram of the operation of the plunger 163. Fig. 8 shows the plunger 163, the engaging portion 166, and the first connecting portion 165 as viewed in the -Z direction. As shown in Fig. 8, the engaging portion 166 has a recess 167 formed along the X direction.

[0038] The upper part of FIG. 8 shows a state in which the first connector 165 is eccentric in the +Y direction with respect to the rotation axis RX1 of the first drive shaft 164. When the control unit 50 rotates the first drive shaft 164 clockwise by 90 degrees from this state, the first connector 165 rotates about the rotation axis RX1 and moves within the recessed portion 167, as shown in the center of FIG. 8, and the plunger 163 moves in the -Y direction. When the control unit 50 further rotates the first drive shaft 164 clockwise by 90 degrees, the first connector 165 moves within the recessed portion 167, as shown in the lower part of FIG. 8, and the plunger 163 further moves in the -Y direction. The control unit 50 controls the first motor 161 to rotate the first connector 165 provided on the first drive shaft 164 about the rotation axis RX1, thereby sliding the plunger 163 within the first cylinder 162 and performing the first and second operations described above.

[0039] 7, in this embodiment, the plunger 163 has its tip end supported by the first cylinder 162, and the rear end side of the plunger 163 is not supported. An engagement portion 166 provided on the plunger 163 is provided with a recess 167 that opens in the +Z direction, and a first connection portion 165 that protrudes from the first drive shaft 164 in the -Z direction fits into the recess 167. With this structure, the plunger 163 engages with the first drive shaft 164 of the first motor 161 so as to be allowed to move along the Z direction.

[0040] The pressure sensor 170 is composed of a second motor 171, a second cylinder 172, and a rod 173. The second cylinder 172 and the rod 173 are provided in the flow path block 141. The second cylinder 172 is connected to the flow path 142 through which the plasticized material flows. In this embodiment, the second cylinder 172 is connected to the flow path 142 upstream of the flow rate adjuster 143. The second cylinder 172 is provided along the Y direction, which is perpendicular to the direction in which the flow path 142 extends. The tip of the second cylinder 172 is connected to the flow path 142, and the rear end of the second cylinder 172 is exposed to the outside of the flow path block 141. The rod 173 slides within the second cylinder 172. The tip of the rod 173 is disposed within the second cylinder 172, and the rear end of the rod 173 is located near the bottom of the second motor 171. The center portion of the rod 173 is inserted into a through-hole 183 of a stay 182 fixed to the lower case 152. The rod 173 is slidable in the through-hole 183 in the Y direction.

[0041] The second drive shaft 174 of the second motor 171 has a second connection part 175 that is eccentric with respect to the rotation axis RX2 of the second drive shaft 174. The second connection part 175 is formed by, for example, a cam follower or a roller follower. In FIG. 7, the second connection part 175 is eccentric in the +X direction with respect to the center of the rotation axis RX2. The rear end of the rod 173 contacts the side surface of the second connection part 175 from the +Y direction side. With this configuration, the rod 173 engages with the second drive shaft 174 of the second motor 171 so as to be allowed to move along the Z direction.

[0042] The rod 173 includes a small diameter portion 177 and a large diameter portion 178 having a diameter larger than that of the small diameter portion 177. The large diameter portion 178 is located on the -Y direction side of the small diameter portion 177. The length of the small diameter portion 177 is longer than the length of the second cylinder 172. A biasing member 176 is disposed between the second cylinder 172 and the large diameter portion 178. The small diameter portion 177 is inserted through the biasing member 176 and the second cylinder 172. The biasing member 176 is, for example, a coil spring. The biasing member 176 biases the rod 173 in a direction away from the flow path 142. As a result, the rear end of the rod 173 always contacts the side surface of the second connection portion 175, and a torque equal to or greater than a certain level is always applied from the rod 173 to the second drive shaft 174.

[0043] The second motor 171 operates to hold the rod 173 at a predetermined position within the second cylinder 172. The function that realizes this operation is called a servo lock function. Through this operation, the second motor 171 maintains the rotational position of the second drive shaft 174 so that the rod 173 does not move within the second cylinder 172 due to the pressure of the plasticized material within the flow path 142. In other words, the second motor 171 operates the rod 173 so that the rod 173 does not move due to the pressure of the plasticized material. In this operation, the greater the force that the rod 173 receives from the flow path 142 and the biasing member 176, the greater the torque that the second motor 171 applies to the second drive shaft 174 to counteract that force. Therefore, the control unit 50 can detect the pressure within the flow path 142 based on the torque value, i.e., the current value, of the second motor 171.

[0044] FIG. 9 is an enlarged cross-sectional view of a portion of plunger 163. Plunger 163 is configured by fastening a rod-shaped tip member 193 having a flange portion at its rear end and a rod-shaped rear end member 194 having a larger diameter than tip member 193 with a fastening member 195. A male thread is formed at the tip of rear end member 194. Fastening member 195 is formed in a cylindrical shape with a bottom. A female thread is formed on the inner circumferential surface of fastening member 195 to be threaded onto the male thread of the rear end member. A through hole 197 is formed at the bottom of fastening member 195. With tip member 193 inserted through through hole 197 of fastening member 195 from the rear end member 194 side, the female thread of fastening member 195 is threaded onto the male thread of the rear end member 194, thereby fastening tip member 193 and rear end member 194 together with fastening member 195. If the fastening force of the fastening member 195 is insufficient or if the fastening member 195 is loose, a gap G is generated between the tip member 193 and the fastening member 195, as shown in the lower part of Fig. 9. As a result, as shown in the upper part of Fig. 9, in the second operation of pushing the plunger 163, the gap G in the fastening member 195 is filled, and in the first operation of pulling the plunger 163, a gap G is generated in the fastening member 195. This gap G is one cause of backlash that occurs in the suction delivery unit 160 serving as the supply control mechanism 148. Note that backlash is not limited to between the tip member 193 and the rear end member 194, but can also occur in the following locations, for example. (1) A gap between the recess 167 formed in the engagement portion 166 and the first connection portion 165 . (2) A gap that occurs due to wear of the rolling elements in the cam follower or roller follower that constitutes the first connecting portion 165. (3) A gap that occurs between the machine key and key groove of the first motor 161. (4) Gap due to wear of the bearings of the first motor 161. (5) A gap that occurs due to the tapered machining precision of the bolt 199 that fastens the engaging portion 166 and the plunger 163.

[0045] 10 is a flowchart of the three-dimensional modeling process executed by the control unit 50. In step S10, the control unit 50 calculates a backlash value representing the backlash of the suction and feed unit 160 based on detection data including detection values ​​output from the pressure sensor 170. The backlash value is represented by the operation delay time of the suction and feed unit 160 or the distance of a gap existing in the suction and feed unit 160. The detection data is data including, in time series, detection values ​​output from the pressure sensor 170 during at least a portion of a period covering a first operation in which the suction and feed unit 160 reduces the amount of plasticized material supplied from the nozzle 13, and a period covering a second operation in which the suction and feed unit 160 increases the amount of plasticized material supplied from the nozzle 13. A method for calculating the backlash value will be described later.

[0046] In step S20, the control unit 50 calculates a correction value for correcting the control timing of the suction and delivery unit 160 based on the backlash value calculated in step S10.

[0047] In step S30, the control unit 50 executes a lamination process based on the modeling data. Prior to the three-dimensional modeling process, the control unit 50 acquires the modeling data from another device or a recording medium and stores it in the memory unit 52. The modeling data records the movement path of the nozzle 13 and the amount of plasticizing material supplied from the nozzle 13 along each movement path. In the lamination process, the control unit 50 controls the position change unit 30, the flow rate adjustment unit 143, and the suction and delivery unit 160 in accordance with the modeling data to supply the plasticizing material to the stage 20 while moving the nozzle 13, thereby laminating multiple modeling layers on the modeling surface 21 and forming a three-dimensional model. In the lamination process, the control unit 50 corrects the control timing of the suction and delivery unit 160 when performing the first operation or the second operation based on the correction value calculated in step S20.

[0048] 11 and 12 are diagrams illustrating a method for calculating backlash. FIG. 11 shows the relationship over time between the commanded position of the plunger 163 and the pressure measured by the pressure sensor 170 when the backlash is small. FIG. 12 shows the relationship over time between the commanded position of the plunger 163 and the pressure measured by the pressure sensor 170 when the backlash is large. The commanded position of the plunger 163 represents the distance from the inner surface of the flow path 142 to the tip surface of the plunger 163. In FIGS. 11 and 12, the operation of pulling the plunger 163, i.e., the first operation, is initiated at time T of 0 ms. In the example shown in FIG. 11, the pressure P detected by the pressure sensor 170 begins to decrease 25 ms after the start of the plunger 163 operation. In the example shown in FIG. 12, the pressure P detected by the pressure sensor 170 begins to decrease 679 ms after the start of the plunger 163 operation. If the first motor 161 that drives the plunger 163 rotates at a speed of 18 degrees per second, in the example shown in FIG. 11 , the backlash is converted into a rotation angle of the first motor 161 of 0.45 degrees, which is converted into a travel distance of the plunger 163 via the conversion mechanism 168 shown in FIG. 8 of 23 μm. In the example shown in FIG. 12 , the backlash is converted into a rotation angle of the first motor 161 of 12.22 degrees, which is converted into a travel distance of the plunger 163 via the conversion mechanism 168 of 635 μm. The control unit 50 can convert the rotation angle into the travel distance of the plunger 163 based on a predetermined function or table. In this way, the control unit 50 calculates the delay time from the start of operation of the plunger 163 to the change in the value of pressure P detected by the pressure sensor 170 and the travel distance of the plunger 163 based on the detection data, and sets these delay time and travel distance as the correction values ​​in step S20. For example, if backlash correction is not performed, the distance to pull the plunger 163 is 1 mm, and the operation command timing for causing the plunger 163 to perform the first operation is set to -10 ms, which is earlier than the scheduled time for changing the movement direction of the nozzle 13.12 is detected, the control unit 50 sets the distance for pulling the plunger 163 to 1.635 mm (= 1 mm + 635 μm) and the operation start timing of the plunger 163 to −689 ms (= −10 ms − 679 ms). By doing so, it is possible to prevent the occurrence of delays in the operation of the plunger 163 or insufficient operation amount of the plunger 163 due to the presence of backlash.

[0049] The control unit 50 can calculate the amount of change in the backlash value over time by comparing the detection data acquired at a first time period with the detection data acquired at a second time period that is later than the first time period. For example, by comparing the detection data at the first time period shown in FIG. 11 with the detection data at the second time period shown in FIG. 12, the control unit 50 can calculate that the start of operation of the plunger 163 at the second time period was delayed by 654 μs (= 679 μs - 25 μs) compared to the first time period, and that the backlash increased by 612 μm (= 635 μm - 23 μm). The control unit 50 may display the calculated amount of change in the backlash value over time on a display device connected to the control unit 50.

[0050] According to the first embodiment described above, the control unit 50 calculates the backlash value based on the time-series data of the detection value output from the pressure sensor 170 that measures the pressure of the plasticized material. Therefore, it is possible to measure the backlash without disassembling the three-dimensional printing apparatus 100.

[0051] Furthermore, according to this embodiment, a correction value is calculated based on the calculated backlash value, and the supply control mechanism 148 is controlled based on the correction value, thereby enabling accurate operation of the supply control mechanism 148. As a result, the molding accuracy of the three-dimensional object can be improved.

[0052] Furthermore, according to this embodiment, the amount of change in the backlash value over time can be calculated by comparing detection data acquired at a first time point with detection data acquired at a second time point that is later than the first time point. Therefore, the amount of change in the backlash value over time can be determined without disassembling the three-dimensional printing apparatus 100. As a result, the degree of wear of each part of the supply control mechanism 148 can be checked over time, making it easy to plan maintenance such as part replacement.

[0053] Furthermore, in this embodiment, supply control mechanism 148 and pressure sensor 170 are supported by different members. Specifically, first motor 161 included in suction delivery section 160 as supply control mechanism 148 is supported by first motor support member 180, and second motor 171 included in pressure sensor 170 is supported by second motor support member 184. Therefore, it is possible to suppress vibrations occurring in supply control mechanism 148 from affecting the detection of pressure by pressure sensor 170.

[0054] In the first embodiment, the control unit 50 calculates the backlash value in the first operation of pulling the plunger 163, but it may also calculate the backlash value in the second operation of pushing the plunger 163.

[0055] B. Second embodiment: 13 and 14 are diagrams illustrating a method for calculating backlash in the second embodiment. The configuration of the three-dimensional printing apparatus 100 in the second embodiment is the same as that in the first embodiment. In the second embodiment, the method for calculating backlash in step S10 of the three-dimensional printing process shown in FIG. 10 is different from that in the first embodiment.

[0056] FIG. 13 shows the change in pressure P when the plunger 163 is caused to perform a first operation and is pulled back 1.6 mm between 200 ms and 2200 ms after the start of pressure P measurement. FIG. 14 shows the change in pressure P when the plunger 163 is caused to perform a second operation and is pushed back 1.6 mm between 200 ms and 2200 ms after the start of pressure P measurement. In the second embodiment, the control unit 50 calculates a time integral value A of the pressure when the plunger 163 is pulled back and a time integral value B of the pressure when the plunger 163 is pushed back. Then, the backlash value X is calculated based on the following equation (1). Note that L is the amount of movement of the plunger 163. In equation (1), it is assumed that a gap due to backlash occurs when the plunger 163 is pulled back.

[0057] B:L=A:(LX) That is, X = L(1 - A / B) (1)

[0058] According to the second embodiment described above, it is possible to accurately calculate the backlash value based on the time integral value of the pressure when the plunger 163 is pulled and the time integral value of the pressure when the plunger 163 is pushed.

[0059] C. Third embodiment: 15 is a diagram illustrating a method for calculating backlash in the third embodiment. The configuration of the three-dimensional printing apparatus 100 in the third embodiment is the same as that in the first embodiment. In the third embodiment, the method for calculating backlash in step S10 of the three-dimensional printing process shown in FIG. 10 is different from that in the first embodiment.

[0060] In the third embodiment, the control unit 50 varies the rotational speed of the first motor 161 for moving the plunger 163, and, as in the first embodiment, determines the time at which the detection value of the pressure sensor 170 begins to change at each rotational speed as the delay time. The delay time for each rotational speed is then plotted on a log-log graph, an approximation line for each plot is found, and its intercept is calculated. The intercept value then becomes the backlash value corresponding to the rotation angle of the first motor 161. For example, if the backlash value determined from the intercept in FIG. 15 is 0.108 degrees, that rotation angle can be converted into the distance traveled by the plunger 163 by the conversion mechanism 168 shown in FIG. 8, for example, 0.0024 mm.

[0061] According to the third embodiment described above, the operation speed of the suction and delivery unit 160 serving as the supply control mechanism 148 is changed, and the operation delay time of the supply control mechanism 148 corresponding to each operation speed is calculated based on the detection data, and the backlash value can be calculated based on the correlation between the operation speed and the operation delay time. This method also makes it possible to accurately calculate the backlash value.

[0062] D. Fourth embodiment: 16 is a diagram illustrating a method for calculating backlash in the fourth embodiment. The configuration of the three-dimensional printing apparatus 100 in the fourth embodiment is the same as that in the first embodiment. In the fourth embodiment, in step S10 of the three-dimensional printing process shown in FIG. 10, the control unit 50 calculates the backlash value based on the detection value of the pressure sensor 170, and also calculates the backlash value for each location where backlash occurs based on the torque change of the first motor 161.

[0063] In the fourth embodiment, the control unit 50 moves the plunger 163 at a constant speed and detects the torque change of the first motor 161 during this movement. The vertical axis of FIG. 16 represents the torque change of the first motor 161 after the plunger 163 starts moving. FIG. 16 shows three stages of torque change. The time Ta until the first torque change corresponds to the backlash value in the bearing of the first motor 161. The time Tb until the second torque change corresponds to the backlash value in the conversion mechanism 168. The time Tc until the third torque change corresponds to the backlash value in the fastening member 195 of the plunger 163. The torque increase at time Tb is due to mechanical loss in the bearing of the first motor 161. The torque increase at time Tc is due to mechanical loss in the conversion mechanism 168. The torque increase after time Tc is due to resistance when the tip of the plunger 163 presses against the plasticized material. In this way, the control unit 50 can calculate the backlash value for each location where backlash occurs by measuring the interval at which torque changes occur.

[0064] According to the fourth embodiment described above, the control unit 50 can calculate the backlash value in each part of the supply control mechanism 148 by analyzing the torque change of the first motor 161 when the plunger 163 moves. The control unit 50 can also analyze the presence or absence of backlash in each part of the supply control mechanism 148, i.e., the location of the backlash, depending on the presence or absence of torque change. Note that the control unit 50 may, for example, display the backlash value for each location where backlash occurs on a display unit connected to the control unit 50.

[0065] E. Fifth embodiment: Fig. 17 is an explanatory diagram showing the schematic configuration of an injection molding apparatus 400 according to the fifth embodiment. The injection molding apparatus 400 includes a material supply device 10, a mold clamping device 410 that opens and closes a molding die 411, and a control unit 50. In Fig. 17, elements corresponding to the various elements in the first embodiment are denoted by the same reference numerals.

[0066] The configuration of the material supplying apparatus 10 in the fifth embodiment is substantially the same as the configuration of the material supplying apparatus 10 in the first embodiment. However, the material supplying apparatus 10 in the fifth embodiment does not include the flow rate adjusting unit 143, and instead includes a check valve 406. The check valve 406 is provided upstream of the suction and delivery unit 160 and the pressure sensor 170 in the flow path 142. The check valve 406 prevents the plasticized material in the flow path 142 from flowing backward.

[0067] In this embodiment, the suction delivery unit 160 has the function of measuring and injecting the plasticized material. The control unit 50 performs a first operation of pulling the plunger 163 of the suction delivery unit 160 to stop the supply of the plasticized material from the nozzle 13 and measure the plasticized material, and performs a second operation of pushing the plunger 163 to send the plasticized material to the flow path 142 and supply the plasticized material from the nozzle 13 to the forming mold 411.

[0068] The forming die 411 is composed of a fixed die 412 and a movable die 413. The fixed die 412 is fixed to the material supply device 10. The movable die 413 is provided so that it can move forward and backward relative to the fixed die 412 in the clamping direction by the clamping device 410. The plasticized material produced by the material supply device 10 is injected from the nozzle 13 into a cavity 416 defined by the fixed die 412 and the movable die 413. The forming die 411 may be made of metal, resin, or ceramic.

[0069] The mold clamping unit 410 includes a mold drive unit 414. The mold drive unit 414 is configured with a motor, gears, etc., and is connected to the movable mold 413 via a ball screw 415. The mold clamping unit 410 drives the mold drive unit 414 under the control of the control unit 50, thereby rotating the ball screw 415 and moving the movable mold 413 relative to the fixed mold 412, thereby opening and closing the casting mold 411.

[0070] In the fifth embodiment described above, as in the first embodiment, the control unit 50 can calculate the backlash value based on the time-series data of the detected values ​​output from the pressure sensor 170 that measures the pressure of the plasticized material prior to injection molding. This allows backlash to be measured without disassembling the injection molding apparatus 400. Furthermore, by calculating a correction value based on the calculated backlash value and controlling the suction / feed unit 160 based on this correction value, the plasticized material can be accurately measured and injected. This improves the quality of the molded product.

[0071] F. Other Embodiments: (F1) In the above-described embodiments, the measurement of backlash in the suction and delivery unit 160 has been described. Backlash measurement is not limited to the suction and delivery unit 160, and may be performed on the flow rate adjustment unit 143 serving as the supply control mechanism 148. In the flow rate adjustment unit 143, backlash may exist, for example, in the bearing of the flow rate adjustment motor 181 or in the coupling 144. Note that the first operation in the flow rate adjustment unit 143 is the operation of closing the valve to reduce the amount of plasticized material supplied from the nozzle 13, and the second operation in the flow rate adjustment unit 143 is the operation of opening the valve to increase the amount of plasticized material supplied from the nozzle 13.

[0072] (F2) In the above embodiment, the first motor 161 that drives the plunger 163 and the second motor 171 that constitutes the pressure sensor 170 are supported by different motor support members 180, 184. In contrast, the first motor 161 and the second motor 171 may be supported by the same support member.

[0073] (F3) In the above embodiment, the three-dimensional modeling apparatus 100 is provided with two material supply devices 10. However, the three-dimensional modeling apparatus 100 may be provided with one material supply device 10 or three or more material supply devices 10.

[0074] G. Other forms: The present disclosure is not limited to the above-described embodiments and can be realized in various configurations without departing from the spirit thereof. For example, the technical features of the embodiments corresponding to the technical features in each aspect described below can be appropriately replaced or combined to solve some or all of the above-described problems or achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be appropriately deleted.

[0075] (1) According to a first aspect of the present disclosure, there is provided a material supply device comprising: a plasticizing unit that plasticizes a material to produce a plasticized material; a nozzle that supplies the plasticized material to the outside; a supply control mechanism that is provided in a flow path that communicates with the plasticizing unit and the nozzle and that adjusts the amount of the plasticized material supplied from the nozzle to the outside; a pressure sensor that measures the pressure of the plasticized material in the flow path; and a controller that controls the operation of the supply control mechanism, wherein the controller calculates a backlash value that represents backlash of the supply control mechanism based on detection data including detection values ​​output from the pressure sensor, and the detection data is data including the detection values ​​output from the pressure sensor in a time series during at least a portion of a period during which the supply control mechanism performs a first operation to reduce the amount of the plasticized material supplied from the nozzle and a period during which the supply control mechanism performs a second operation to increase the amount of the plasticized material supplied from the nozzle. According to this embodiment, the backlash is calculated based on time-series data of the detected values ​​output from the pressure sensor that measures the pressure of the plasticized material, so that the backlash can be measured without disassembling the device.

[0076] (2) In the above embodiment, the control unit may calculate the amount of change in the backlash value over time by comparing the detection data acquired at a first time point with the detection data acquired at a second time point that is later than the first time point. According to this embodiment, the amount of change in the backlash over time can be obtained without disassembling the device.

[0077] (3) In the above embodiment, the supply control mechanism may include a cylinder connected to the flow path, a plunger disposed in the cylinder, and a drive unit that drives the plunger, and the control unit may perform the first operation by controlling the drive unit to pull the plunger to suck the plasticized material from the flow path into the cylinder, and perform the second operation by controlling the drive unit to push the plunger to send the plasticized material from the cylinder to the flow path, and the control unit may calculate the backlash value based on a time integral of the detection value over a period spanning the first operation and a time integral of the detection value over a period spanning the second operation. This embodiment allows for accurate calculation of backlash.

[0078] (4) In the above aspect, the control unit may calculate an operation delay time of the supply control mechanism corresponding to each operation speed based on the detection data while changing the operation speed of the supply control mechanism, and calculate the backlash value based on the correlation between the operation speed and the operation delay time. According to this aspect, the backlash can be calculated with high accuracy.

[0079] (5) In the above aspect, the control unit may control the operation of the supply control mechanism based on the calculated backlash value. According to this aspect, the supply control mechanism can be operated accurately.

[0080] (6) In the above embodiment, the supply control mechanism may include a cylinder connected to the flow path, a plunger disposed in the cylinder, a drive unit including a motor for driving the plunger, and a conversion mechanism for converting the rotational motion of the motor into the linear motion of the plunger, and the control unit may calculate a backlash value for each location where the backlash occurs based on a torque change of the motor. According to this embodiment, the backlash can be measured for each location where the backlash occurs without disassembling the device.

[0081] (7) In the above-described embodiment, the supply control mechanism and the pressure sensor may be supported by different members. This embodiment can prevent backlash present in the supply control mechanism from affecting measurements by the pressure sensor.

[0082] The present disclosure is not limited to the above-described material supply device, but can be realized in various forms, such as a three-dimensional modeling device including a material supply device, or an injection molding device including a material supply device. [Explanation of symbols]

[0083] 10...Material supply device, 11...Raw material supply section, 12...Plasticization section, 13...Nozzle, 15...Communicating passage, 20...Stage, 21...Building surface, 30...Position change section, 31...First electric actuator, 32...Second electric actuator, 33...Third electric actuator, 40...First heating section, 41...Moving section, 42...Opening, 50...Control section, 51...Processor, 52...Memory section, 100...Three-dimensional modeling device, 110...Screw, 111...Channel forming surface, 112...center portion, 113...groove, 114...inlet port, 115...ridge portion, 120...screw drive motor, 121...drive shaft, 130...barrel, 131...opposing surface, 132...communicating hole, 133...guide groove, 140...discharge portion, 141...flow path block, 142...flow path, 143...flow rate adjustment portion, 144...coupling, 145...discharge port, 148...supply control mechanism, 151...upper case, 152...lower case, 160...suction delivery portion, 16 1...first motor, 162...first cylinder, 163...plunger, 164...first drive shaft, 165...first connection portion, 166...engagement portion, 167...recess, 168...conversion mechanism, 170...pressure sensor, 171...second motor, 172...second cylinder, 173...rod, 174...second drive shaft, 175...second connection portion, 176...urging member, 177...small diameter portion, 178...large diameter portion, 180...first motor support member, 181...flow rate adjustment motor motor, 182...stay, 183...through hole, 184...second motor support member, 193...front end member, 194...rear end member, 195...fastening member, 197...through hole, 199...bolt, 201...second heating section, 203...third heating section, 211...support section, 400...injection molding device, 406...check valve, 410...mold clamping device, 411...molding mold, 412...fixed mold, 413...movable mold, 414...mold drive section, 415...ball screw, 416...cavity

Claims

1. a plasticizing section for plasticizing the material to produce a plasticized material; a nozzle for supplying the plasticized material to the outside; a supply control mechanism provided in a flow path communicating with the plasticizing unit and the nozzle, the supply control mechanism adjusting the amount of the plasticizing material supplied from the nozzle to the outside; a pressure sensor for measuring the pressure of the plasticized material in the flow path; a control unit that controls the operation of the supply control mechanism, the control unit calculates a backlash value representing a backlash of the supply control mechanism based on detection data including a detection value output from the pressure sensor; The detection data is data including, in time series, the detection values ​​output from the pressure sensor during at least a portion of a period during which the supply control mechanism performs a first operation to reduce the supply amount of the plasticizing material from the nozzle, and a period during which the supply control mechanism performs a second operation to increase the supply amount of the plasticizing material from the nozzle. Material feeding device.

2. The material supply device according to claim 1, The control unit calculates the amount of change in the backlash value over time by comparing the detection data acquired at a first time period with the detection data acquired at a second time period that is later than the first time period.

3. The material supply device according to claim 1, the supply control mechanism includes a cylinder connected to the flow path, a plunger disposed in the cylinder, and a drive unit that drives the plunger; The control unit performing the first action by controlling the drive unit to pull the plunger to draw the plasticized material from the flow passage into the cylinder; performing the second action by controlling the drive unit to push the plunger to deliver the plasticized material in the cylinder to the flow path; the control unit calculates the backlash value based on a time integral value of the detection value during a period covering the first operation and a time integral value of the detection value during a period covering the second operation. Material feeding device.

4. The material supply device according to claim 1, The control unit changes the operating speed of the supply control mechanism, calculates the operating delay time of the supply control mechanism corresponding to each operating speed based on the detection data, and calculates the backlash value based on the correlation between the operating speed and the operating delay time.

5. The material supply device according to claim 1, The control unit controls the operation of the supply control mechanism based on the calculated backlash value.

6. The material supply device according to claim 1, the supply control mechanism includes a cylinder connected to the flow path, a plunger disposed in the cylinder, a drive unit including a motor that drives the plunger, and a conversion mechanism that converts rotational motion of the motor into linear motion of the plunger; The control unit calculates a backlash value for each location where the backlash occurs based on a change in torque of the motor.

7. The material supply device according to claim 1, A material supply device, wherein the supply control mechanism and the pressure sensor are supported by different members.

8. The material supply device according to claim 1; a stage onto which the plasticized material is supplied from the material supply device and deposited; A three-dimensional printing apparatus comprising:

9. The material supply device according to claim 1; a mold clamping device that opens and closes a molding die having a cavity to which the plasticized material is supplied from the material supply device; An injection molding apparatus comprising:

Images