System of manufacturing three-dimensional modeled object

Abstract

To solve a problem in conventional techniques where processing the back surface side of a three-dimensional modeled object has not been considered.SOLUTION: A system of manufacturing a three-dimensional modeled object comprises: a processing unit having either one of a modeling unit of discharging a modeling material from a nozzle to deposit it, and a cutting / grinding unit having a cutting / grinding tool; a holding unit for holding an intermediate body, which is to become a three-dimensional modeled object, in a state in which a back surface, the back surface being a surface opposite to a front surface formed on the intermediate body, faces the processing unit; and a control unit. The holding unit has a sensor for detecting a force received from the intermediate body. The control unit executes a process for controlling the processing unit in accordance with processing conditions to process the back surface side of the intermediate body in a state in which the intermediate body is held by the holding unit, to manufacture the three-dimensional modeled object. The control unit changes the processing conditions in accordance with a value of the force detected by the sensor.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a system for manufacturing a three-dimensional object. [Background technology]

[0002] Patent Document 1 discloses a method for manufacturing a three-dimensional object, in which a cutting tool is used to cut a portion of a modeling material stacked on a stage, thereby forming a three-dimensional object of a desired shape. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-104439 A Summary of the Invention [Problem to be solved by the invention]

[0004] In conventional techniques, processing of the back side of a three-dimensional object has not been taken into consideration. [Means for solving the problem]

[0005] According to a first aspect of the present disclosure, there is provided a system for manufacturing a three-dimensional object, the system for manufacturing a three-dimensional object comprising a processing unit having at least one of a modeling unit that ejects modeling material from a nozzle and stacks the material and a cutting unit having a cutting tool, a holding unit that holds an intermediate body that will become the three-dimensional object in a state where the back surface of the intermediate body, which is the surface opposite to the front surface formed on the intermediate body, faces the processing unit, and a control unit, the holding unit has a sensor that detects a force received from the intermediate body, the control unit controls the processing unit to process the back surface side of the intermediate body according to processing conditions while the intermediate body is held by the holding unit, thereby manufacturing the three-dimensional object, and the control unit changes the processing conditions according to the value of the force detected by the sensor. [Brief description of the drawings]

[0006] [Figure 1] FIG. 1 is an explanatory diagram illustrating a schematic configuration of a manufacturing system for a three-dimensional object. [Diagram 2] FIG. 2 is an explanatory diagram showing a schematic configuration of a molding unit. [Diagram 3] FIG. 2 is a perspective view of a flat screw. [Figure 4] FIG. [Diagram 5] 4 is a schematic cross-sectional view showing the configuration of a holding portion. FIG. [Figure 6] 11A to 11C are explanatory diagrams showing the operation of a holding portion. [Figure 7] 1 is a flowchart showing a method for manufacturing a three-dimensional object. [Figure 8] FIG. 11 is an explanatory diagram showing a schematic configuration of a manufacturing system according to a second embodiment. [Figure 9] 10 is a flowchart showing a manufacturing method according to a second embodiment. [Figure 10] 13A to 13C are diagrams illustrating a modified example of the second heating section in the second embodiment. [Figure 11] FIG. 13 is an explanatory diagram showing a schematic configuration of a manufacturing system according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] A. First embodiment: FIG. 1 is an explanatory diagram showing a schematic configuration of a three-dimensional object manufacturing system 100 in the first embodiment. FIG. 1 shows arrows indicating mutually orthogonal X, Y, and Z directions. The X and Y directions are parallel to a horizontal plane, and the Z direction is opposite to the direction of gravity. The arrows indicating the X, Y, and Z directions are also shown in other figures as appropriate so that the illustrated directions correspond to those in FIG. 1. In the following description, when specifying a direction, positive and negative signs are used in combination to indicate the direction, with the positive direction indicated by the arrow being "+" and the negative direction opposite to the direction indicated by the arrow being "-".

[0008] The manufacturing system 100 in this embodiment includes a modeling unit 200 as a processing unit, a cutting unit 250 as a processing unit, a stage 300, a moving mechanism 400, a control unit 500, and a holding unit 600. Under the control of the control unit 500, the manufacturing system 100 discharges a modeling material from a nozzle 61 provided in the modeling unit 200 toward the stage 300, while driving the moving mechanism 400 to change the relative position between the nozzle 61 and the stage 300, thereby stacking the modeling material on the stage 300. Under the control of the control unit 500, the manufacturing system 100 rotates a cutting tool 260 attached to the cutting unit 250, while driving the moving mechanism 400 to change the relative position between the cutting tool 260 and the stage 300, thereby cutting the modeling material stacked on the stage 300 with the cutting tool 260. The holding unit 600 is configured to be fixed to the stage 300. The holding unit 600 holds an intermediate body which is a preliminary form of a three-dimensional object.

[0009] In the manufacturing system 100 of this embodiment, first, an intermediate body is formed on the stage 300 by the forming unit 200. Next, the intermediate body is turned upside down and held by the holding unit 600 with the back surface of the intermediate body facing the cutting unit 250. Thereafter, the back surface of the intermediate body is cut by the cutting unit 250, thereby producing a three-dimensional object of a desired shape. The back surface of the intermediate body is the surface opposite to the front surface that has been formed in advance on the intermediate body.

[0010] The cutting unit 250 is a cutting device that cuts the modeling material stacked on the stage 300 by rotating the cutting tool 260 attached to the shaft at the tip of the head. For example, a flat end mill or a ball end mill can be used as the cutting tool 260. The cutting unit 250 detects the position of the tip of the cutting tool 260 by a general position detection sensor and transmits the detection result to the control unit 500. The control unit 500 uses the detection result to control the moving mechanism 400 to change the relative position between the cutting tool 260 and the intermediate body held by the holding unit 600 and cut the intermediate body. The cutting unit 250 may be equipped with a static eliminator such as an ionizer.

[0011] The stage 300 is supported by a moving mechanism 400. The stage 300 has a modeling surface 310 that faces the modeling unit 200 and the cutting unit 250. A modeling material is layered on the modeling surface 310. In this embodiment, the modeling surface 310 is provided parallel to a horizontal plane.

[0012] The moving mechanism 400 changes the relative position between the modeling unit 200 and the stage 300, and the relative position between the cutting unit 250 and the stage 300. In this embodiment, the moving mechanism 400 changes the relative position between the modeling unit 200 and the stage 300, and the relative position between the cutting unit 250 and the stage 300 by moving the stage 300. The moving mechanism 400 in this embodiment is configured by a three-axis positioner that moves the stage 300 in three axial directions, that is, the X, Y, and Z directions, by the driving forces of three motors. Each motor is driven under the control of the control unit 500. Note that the moving mechanism 400 may be configured not to move the stage 300, but to change the relative positions between the modeling unit 200 and the stage 300 and the relative positions between the cutting unit 250 and the stage 300 by moving the modeling unit 200 and the cutting unit 250 without moving the stage 300. In this case, the moving mechanism 400 may be configured to move the modeling unit 200 and the cutting unit 250 as a unit relative to the stage 300, or may be configured to move the modeling unit 200 and the cutting unit 250 independently of each other. The moving mechanism 400 may be configured to change the relative positions of the modeling unit 200 and the stage 300 and the relative positions of the cutting unit 250 and the stage 300 by moving the modeling unit 200, the cutting unit 250, and the stage 300. The moving mechanism 400 may have a function of tilting the modeling surface 310 of the stage 300 with respect to the horizontal plane, or may have a function of tilting the nozzle 61 and the cutting tool 260 with respect to the modeling surface 310.

[0013] The control unit 500 is configured by a computer having one or more processors, a main storage device, and an input / output interface for inputting and outputting signals from and to the outside. The control unit 500 performs various functions by the processor executing programs and instructions loaded onto the main storage device. In this embodiment, the control unit 500 has a data generation unit 501. The data generation unit 501 generates modeling data and cutting data used to manufacture a three-dimensional object. In addition, the control unit 500 executes a process for manufacturing a three-dimensional object using the modeling data and cutting data. Note that the control unit 500 may be configured by a combination of multiple circuits instead of a computer.

[0014] Fig. 2 is an explanatory diagram showing a schematic configuration of the modeling unit 200 in this embodiment. In Fig. 2, a stage 300, a moving mechanism 400, and a control unit 500 are shown together with the modeling unit 200. The modeling unit 200 includes a material supply unit 20 which is a supply source of the material MR, a plasticizing unit 30 which plasticizes the material MR to turn it into a modeling material, and a discharging unit 60 which discharges the modeling material.

[0015] "Plasticization" is a concept that includes melting, and refers to changing 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 material supply unit 20 supplies the material MR to the plasticization unit 30 to generate the modeling material. In this embodiment, ABS resin formed into pellets is used as the material MR. In this embodiment, the material supply unit 20 is configured by a hopper that stores the material MR. A supply path 22 that connects the material supply unit 20 and the plasticization unit 30 is provided below the material supply unit 20. The material MR stored in the material supply unit 20 is supplied to the plasticization unit 30 via the supply path 22.

[0017] The plasticizing unit 30 plasticizes the material MR supplied from the material supply unit 20 to form a modeling material, and supplies the modeling material to the discharge unit 60. The plasticizing unit 30 includes a screw case 31, a drive motor 32, a flat screw 40, a barrel 50, and a first heating unit 58. The screw case 31 is a housing that houses the flat screw 40. The barrel 50 is fixed to the lower end of the screw case 31, and the flat screw 40 is housed in a space surrounded by the screw case 31 and the barrel 50.

[0018] The flat screw 40 has a generally cylindrical shape in which the length in the axial direction, which is the direction along the central axis RX, is smaller than the length in the direction perpendicular to the axial direction. The flat screw 40 is disposed in the screw case 31 so that the central axis RX is parallel to the Z direction. The upper surface 41 side of the flat screw 40 is connected to the drive motor 32. The flat screw 40 rotates about the central axis RX by the torque generated by the drive motor 32. The flat screw 40 and the drive motor 32 may be connected via a reducer. The flat screw 40 has a groove forming surface 42 on which a groove portion 45 is formed on the opposite side to the upper surface 41. The barrel 50 has a screw facing surface 52 facing the groove forming surface 42 of the flat screw 40. A communication hole 56 communicating with the discharge portion 60 is provided in the center of the screw facing surface 52.

[0019] FIG. 3 is a perspective view showing the configuration of the flat screw 40. In FIG. 3, the flat screw 40 is shown upside down from FIG. 2 in order to facilitate understanding of the technology. In FIG. 3, the position of the central axis RX of the flat screw 40 is shown by a dashed line. The central portion 47 of the groove forming surface 42 of the flat screw 40 is configured as a recess to which one end of the groove portion 45 is connected. The central portion 47 faces the communication hole 56 of the barrel 50 shown in FIG. 2. The central portion 47 intersects with the central axis RX. In this embodiment, the groove portion 45 extends in a spiral shape so as to draw an arc from the central portion 47 toward the outer periphery of the flat screw 40. The groove portion 45 may be configured in an involute curve shape or may be configured to extend in a spiral shape. The groove forming surface 42 is provided with a convex rib portion 46 that constitutes the side wall portion of the groove portion 45 and extends along each groove portion 45. The groove portion 45 is continuous to a material inlet 44 formed on the side surface 43 of the flat screw 40. The material inlet 44 is a portion that receives the material MR supplied through the supply path 22 of the material supply unit 20. The material MR introduced into the groove portion 45 from the material inlet 44 is transported in the groove portion 45 toward the center portion 47 by the rotation of the flat screw 40.

[0020] FIG. 3 shows a flat screw 40 having three grooves 45 and three ridges 46. The number of grooves 45 and ridges 46 provided on the flat screw 40 is not limited to three. The flat screw 40 may have only one groove 45, or two or more grooves 45. Any number of ridges 46 may be provided in accordance with the number of grooves 45. FIG. 3 shows a flat screw 40 in which a material inlet 44 is formed at three locations. The position of the material inlet 44 provided on the flat screw 40 is not limited to three locations. The flat screw 40 may have the material inlet 44 provided at only one location, or two or more locations.

[0021] 4 is a top view showing the configuration of the barrel 50. As described above, a communication hole 56 communicating with the discharge portion 60 is formed in the center of the screw-facing surface 52. A plurality of guide grooves 54 are formed around the communication hole 56 in the screw-facing surface 52. One end of each guide groove 54 is connected to the communication hole 56, and extends in a spiral shape from the communication hole 56 toward the outer periphery of the screw-facing surface 52. Each guide groove 54 has a function of guiding the molding material to 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 a guide groove 54 formed therein.

[0022] As shown in Fig. 2, a first heating unit 58 for heating the material MR is embedded in the barrel 50. The first heating unit 58 may not be embedded in the barrel 50, but may be disposed, for example, below the barrel 50. The output of the first heating unit 58 is controlled by the control unit 500. The material MR transported in the groove portion 45 is plasticized by shearing caused by the rotation of the flat screw 40 and heat from the first heating unit 58, and becomes a paste-like modeling material. The modeling material is supplied to the discharge unit 60 from the communication hole 56.

[0023] The discharge unit 60 discharges the modeling material supplied from the plasticizing unit 30. The discharge unit 60 includes a nozzle 61, a flow path 65, and a discharge adjustment unit 63. The nozzle 61 is provided at the lower end of the discharge unit 60. The lower end of the nozzle 61 is provided with a nozzle opening 62 for discharging the modeling material. In this embodiment, the nozzle 61 is provided with the nozzle opening 62 having a circular opening shape. The shape of the nozzle opening 62 is not limited to a circle, and may be, for example, an ellipse or a polygon such as a rectangle. The flow path 65 communicates with the communication hole 56 of the barrel 50 and the nozzle opening 62, and the modeling material flows from the communication hole 56 toward the nozzle opening 62. The modeling material that flows through the flow path 65 is discharged from the nozzle opening 62.

[0024] The discharge adjustment unit 63 is provided in the flow path 65 and changes the opening degree of the flow path 65 by rotating in the flow path 65. In this embodiment, the discharge adjustment unit 63 is configured with a valve. The control unit 500 adjusts the flow rate of the modeling material flowing from the plasticization unit 30 to the nozzle 61, that is, the discharge amount of the modeling material discharged from the nozzle 61, by controlling the rotation angle of the valve. The discharge adjustment unit 63 can adjust the discharge amount of the modeling material and can also control the on / off of the outflow of the modeling material.

[0025] In this embodiment, the second heating unit 70 is disposed at a position facing the stage 300. The second heating unit 70 is disposed above the nozzle opening 62. The second heating unit 70 has a plate-like shape that covers at least a part of the stage 300. The second heating unit 70 is, for example, configured by a rubber heater. The second heating unit 70 heats the modeling material discharged toward the stage 300. More specifically, the second heating unit 70 heats the upper layer of the layers stacked on the stage 300 by discharging the modeling material from the nozzle opening 62. By heating the upper layer by the second heating unit 70, the degree of adhesion between the layers can be increased. The second heating unit 70 is controlled by the control unit 500. The second heating unit 70 corresponds to the "heating unit" in this application. Note that the second heating unit 70 is not limited to a rubber heater, and may be configured by a halogen heater, a nichrome wire heater, a carbon heater, or the like. Further, the second heating section 70 is not limited to a plate shape, and may have, for example, a circular ring shape so as to surround the periphery of the nozzle 61.

[0026] 5 is a schematic cross-sectional view showing the configuration of the holding portion 600. The holding portion 600 includes a rod-shaped hollow member 610, a first support 620, a second support 630, and a fixing member 640.

[0027] The hollow members 610 are rod-shaped members arranged in parallel to each other. The hollow members 610 are formed of, for example, SUS. The hollow members 610 are provided with a cylindrical contact member 611 at their tips. The contact member 611 is a member that comes into contact with the intermediate body IB, and is formed of, for example, a soft member such as silicone rubber. The hollow members 610 are two-dimensionally arranged in the X and Y directions when viewed from the +Z direction. A cylindrical tube 612 is connected to the base end of the hollow members 610.

[0028] The first support 620 is a member for supporting the hollow member 610. A plurality of first through holes 621 are formed in the first support 620. The hollow member 610 passes through the first through holes 621. The first through holes 621 have gaps 622 where the gap between the first through holes 621 and the hollow member 610 becomes larger toward the second support 630.

[0029] The second support 630 is disposed facing the first support 620. The second support 630 has a plurality of second through holes 631 formed at positions corresponding to the plurality of first through holes 621. The hollow member 610 passes through the second through holes 631. The second support 630 is configured to be relatively movable toward the first support 620 by various actuators, such as a pneumatic actuator or an electric actuator, whose drive is controlled by the control unit 500.

[0030] A columnar fixing member 640 is disposed between the first support 620 and the second support 630. In this embodiment, a base end of the fixing member 640 is fixed to the second support 630. The fixing member 640 has a shape that tapers toward the first support 620 so as to enter the gap 622 of the first through-hole 621. In the gap 622, the fixing member 640 comes into contact with a part of the outer periphery of the hollow member 610.

[0031] FIG. 6 is an explanatory diagram showing the operation of the holding unit 600. First, the tips of the hollow members 610 are brought into contact with the surface of the intermediate body IB. In this way, the position of the hollow members 610 in the Z direction is adjusted according to the shape of the surface of the intermediate body IB. After the tips of the hollow members 610 are brought into contact with the surface of the intermediate body IB, the second support 630 is brought close to the first support 620, and the second support 630 pushes the fixing member 640 into the gap portion 622, so that the fixing member 640 becomes a wedge and the hollow member 610 is fixed to the first support 620. Then, the suction device 660 connected to the tube 612 is used to suck the intermediate body IB through the hollow member 610. In this way, the holding unit 600 can hold the intermediate body IB with the back surface of the intermediate body IB facing the processing portion.

[0032] Each hollow member 610 is provided with a sensor 650. The sensor 650 is, for example, composed of a pressure-sensitive element such as a load cell. In this embodiment, the sensor 650 is embedded in the contact member 611. The sensor 650 may be provided at the base end of the hollow member 610. The sensor 650 may also be composed of a strain gauge and provided on the side of the hollow member 610. The sensor 650 is connected to the control unit 500. The sensor 650 detects the force received from the intermediate body IB. If this force is large, for example, a large force is applied from the cutting unit 250 to the intermediate body IB, and the intermediate body IB is more likely to peel off from the holding unit 600. Hereinafter, the value of the force detected by the sensor 650 is also referred to as a "measured value." Note that, in other embodiments, one sensor 650 may be provided for the holding unit 600.

[0033] 7 is a flowchart showing a method for manufacturing a three-dimensional object. In step S10, the control unit 500 controls the modeling unit 200 and the moving mechanism 400 in accordance with the modeling data to stack modeling material on the stage 300 and model an intermediate IB, which is a precursor to a three-dimensional object. The modeling data includes path data indicating the movement path of the discharging unit 60 and discharge amount data indicating the amount of modeling material discharged from the discharging unit 60. In the first embodiment, of the modeled intermediate IB, the surface shaped by the modeling unit 200 is the front surface, and the unmachined surface in contact with the stage 300 is the back surface.

[0034] In step S20, the holding unit 600 holds the intermediate IB with the back surface of the intermediate IB facing the cutting unit 250. The holding unit 600 is fixed to the stage 300 with bolts or the like while holding the intermediate IB. In step S20, for example, an operator removes the intermediate IB that has been printed on the printing surface 310 from the printing surface 310, holds the front surface of the intermediate IB in the holding unit 600, and fixes the holding unit 600 to the stage 300 so that the back surface of the intermediate IB faces the cutting unit 250.

[0035] In step S30, the control unit 500 starts the execution of a processing process for processing the back side of the intermediate body IB by controlling the cutting unit 250 as a processing unit according to the processing conditions defined in the cutting data. The processing process in the first embodiment is a process for cutting the back side of the intermediate body IB by controlling the cutting tool 260 and the moving mechanism 400. The processing conditions are, for example, a cutting path representing the tool path of the cutting tool 260, the cutting amount of the cutting tool 260, the feed rate of the cutting tool 260, and the rotation speed of the cutting tool 260. The cutting path is the movement path of the cutting tool 260. The intermediate body IB is cut by one or more cutting passes. When cutting by multiple cutting passes, the cutting tool 260 is not in contact with the intermediate body IB when the cutting pass is switched.

[0036] In step S40, the control unit 500 acquires a measurement value from the sensor 650.

[0037] In step S50, the control unit 500 judges whether or not a measurement value acquired from any of the sensors 650 provided in each hollow member 610 exceeds a predetermined threshold. The threshold is determined in advance by experiment or simulation as, for example, a force value immediately before the intermediate body IB is peeled off from the holding unit 600 due to a large force being applied to the intermediate body IB from the cutting tool 260 provided in the cutting unit 250.

[0038] When it is determined in step S50 that the measured value exceeds the threshold value, the control unit 500 changes the processing conditions in step S60. Specifically, the control unit 500 reduces the cutting amount per unit time as a processing condition, thereby suppressing the intermediate body IB from peeling off from the holding unit 600.

[0039] In this embodiment, the control unit 500 reduces the cutting amount per unit time by adjusting at least one of the feed speed of the cutting tool 260 and the rotation speed of the cutting tool 260 without changing the cutting depth of the cutting tool 260 during the cutting pass of the cutting tool 260. For example, the control unit 500 can reduce the cutting amount per unit time by decreasing the feed speed of the cutting tool 260. Also, the control unit 500 can reduce the cutting amount per unit time by decreasing the rotation speed of the cutting tool 260. The control unit 500 adjusts the cutting amount per unit time so that the force measured by the sensor 650 is equal to or less than the above-mentioned threshold value.

[0040] If it is determined in step S50 that the measured value does not exceed the threshold value, or if the processing conditions are changed in step S60, the control unit 500 determines in step S70 whether cutting is complete. The control unit 500 determines that cutting is complete when all cutting passes are complete. When cutting is complete, the manufacture of the three-dimensional object is complete. If cutting is not complete, the control unit 500 returns the process to step S40 and continues cutting.

[0041] According to the first embodiment described above, by holding the intermediate IB by the holding unit 600, the back side of the intermediate IB can be processed to produce a three-dimensional object. In particular, in this embodiment, when cutting the back side of the intermediate IB before it becomes a three-dimensional object, the processing conditions in the cutting unit 250 are changed according to the measurement value acquired from the sensor 650. More specifically, when the force that the intermediate IB receives from the cutting unit 250 during the processing exceeds a threshold value, the cutting amount per unit time by the cutting tool 260 is reduced to prevent the intermediate IB from peeling off from the holding unit 600. Therefore, the back side of the intermediate IB can be processed with high precision.

[0042] In this embodiment, the holding unit 600 includes a plurality of hollow members 610, a first support 620, a second support 630, and a fixing member 640. The holding unit 600 fixes the position of the hollow members 610 by bringing the tips of the plurality of hollow members 610 into contact with the surface of the intermediate body IB, and then moving the second support 630 closer to the first support 620 and pushing the fixing member 640 into the gap 622. Therefore, even if the surface of the intermediate body IB is curved or uneven, the intermediate body IB can be well adsorbed and held. In particular, in this embodiment, the fixing member 640 is not provided around the entire circumference of the hollow member 610, but is provided only on a part of the outer circumference of the hollow member 610. Therefore, the arrangement interval between the hollow members 610 can be narrowed, and the contact area of ​​the hollow member 610 with respect to the intermediate body IB can be increased. As a result, the adsorption force of the intermediate body IB can be improved.

[0043] In addition, in this embodiment, when changing the processing conditions, at least one of the feed speed of the cutting tool 260 and the rotation speed of the cutting tool 260 is adjusted during the cutting pass of the cutting tool 260, thereby reducing the cutting amount per unit time. In other words, the cutting depth is not changed during the cutting pass. Therefore, it is possible to suppress the occurrence of steps in the cut portion of the intermediate body IB and the deterioration of processing accuracy.

[0044] In another embodiment, the cutting amount per unit time may be reduced by correcting the next cutting pass so that the cutting amount by the cutting tool 260 is reduced. This also prevents the cutting amount from changing during the cutting pass, so that it is possible to suppress the occurrence of steps in the cut portion of the intermediate body IB. Which machining condition is adjusted among the above-mentioned feed speed of the cutting tool 260, the rotation speed of the cutting tool 260, and the cutting amount in the next cutting pass may be selected according to a predetermined program, or may be selected according to the learning result of the effect on machining accuracy by machine learning. In addition, one of these machining conditions may be adjusted, or two or more of these machining conditions may be adjusted.

[0045] B. Second embodiment: 8 is an explanatory diagram showing a schematic configuration of a three-dimensional object manufacturing system 101 in the second embodiment. The manufacturing system 101 in the second embodiment includes a modeling unit 200, but does not include a cutting unit 250. In the second embodiment, the modeling unit 200 also functions as a processing unit. The configurations of the modeling unit 200, stage 300, moving mechanism 400, control unit 500, and holding unit 600 are the same as those in the first embodiment.

[0046] 9 is a flowchart showing a method for manufacturing a three-dimensional object in the second embodiment. In step S110, the control unit 500 controls the modeling unit 200 and the moving mechanism 400 to stack the modeling material on the stage 300 and model an intermediate body IB, which is a precursor to the three-dimensional object.

[0047] In step S120, the holding unit 600 holds the preform IB in a state where the back surface of the preform IB faces the modeling unit 200. The holding unit 600 is fixed to the stage 300 in a state where the holding unit 600 holds the preform IB.

[0048] In step S130, the control unit 500 starts executing a processing process to process the back side of the intermediate body IB by controlling the modeling unit 200 as a processing unit in accordance with the modeling data and predetermined processing conditions. The processing process in the second embodiment is a process of stacking a modeling material on the back side of the intermediate body IB by controlling the modeling unit 200 and the moving mechanism 400. The processing condition in the second embodiment is, for example, the heating temperature by the second heating unit 70. At the start of modeling, the heating temperature is set to a predetermined temperature.

[0049] In step S140, the control unit 500 acquires a measurement value from the sensor 650.

[0050] In step S150, the control unit 500 determines whether or not a measurement value acquired from any of the sensors 650 provided in each hollow member 610 exceeds a predetermined threshold. The threshold is determined in advance by experiment or simulation as a force value immediately before the intermediate IB is peeled off from the holding unit 600 due to a large force being applied to the intermediate IB due to deformation caused by cooling contraction of the modeling material, for example.

[0051] If it is determined in step S150 that the measured value exceeds the threshold, the control unit 500 changes the processing conditions in step S160. Specifically, the control unit 500 increases the heating temperature by the second heating unit 70 as a processing condition to suppress peeling of the intermediate IB from the holding unit 600. The control unit 500 adjusts the heating temperature of the second heating unit 70 so that the force measured by the sensor 650 is equal to or less than the threshold.

[0052] If it is determined in step S150 that the measured value does not exceed the threshold value, or if the processing conditions are changed in step S160, the control unit 500 determines in step S170 whether or not modeling of the back side of the intermediate IB is completed. When modeling of the back side of the intermediate IB is completed, the manufacture of the three-dimensional object is completed. If modeling of the back side of the intermediate IB is not completed, the control unit 500 returns the process to step S140 and continues modeling of the back side of the intermediate IB.

[0053] According to the second embodiment described above, when modeling the back side of the intermediate IB, the heating temperature of the second heating unit 70 is changed in accordance with the measurement value acquired from the sensor 650. More specifically, when the force that the sensor 650 receives from the intermediate IB exceeds a threshold value during modeling of the back side of the intermediate IB, the heating temperature of the second heating unit 70 is increased. This makes it possible to suppress detachment of the intermediate IB from the holding unit 600 due to deformation or the like caused by cooling and contraction of the intermediate IB. Therefore, it is possible to perform modeling with high accuracy on the back side of the intermediate IB.

[0054] FIG. 10 is a diagram for explaining a modified example of the second heating section 70 in the second embodiment. FIG. 10 shows the second heating section 70 as viewed from the stage side. As shown in FIG. 10, the second heating section 70 may include a plurality of heating areas AR, and the control section 500 may be capable of individually adjusting the temperature for each heating area AR. In this case, in step S160 of FIG. 9, the control section 500 makes the heating temperature of the heating area AR corresponding to the position of the hollow member 610 including the sensor 650 whose measured value exceeds the threshold higher than the heating temperature before the measured value exceeds the threshold. In this way, the part of the intermediate IB that is likely to peel off from the holding section 600 can be locally heated to prevent the part from peeling off.

[0055] C. Third embodiment: 11 is an explanatory diagram showing a schematic configuration of a three-dimensional object manufacturing system 102 in the third embodiment. The manufacturing system 102 in the third embodiment includes a modeling unit 200 and does not include a cutting unit 250, as in the manufacturing system 101 in the second embodiment. In the second embodiment, a three-dimensional object is manufactured by modeling the back surface of an intermediate body IB modeled by the modeling unit 200. In contrast, in the third embodiment, an intermediate body IB is manufactured by an injection molding machine 700, and the back surface of the intermediate body IB is modeled by the modeling unit 200, thereby manufacturing a three-dimensional object.

[0056] The flowchart of the method for manufacturing a three-dimensional object in the third embodiment is almost the same as the flowchart in the second embodiment shown in Fig. 9. The difference is that in step S110, the intermediate body IB is manufactured by the injection molding machine 700 instead of being molded by the molding unit 200, and the processes in the other steps are the same. In the third embodiment, of the intermediate body IB molded by injection molding, the surface corresponding to the design surface formed on the intermediate body IB is the front surface, and the opposite surface is the back surface.

[0057] According to the third embodiment described above, a three-dimensional object can be formed by stacking a modeling material on the back side of a part manufactured by the injection molding machine 700. When stacking the modeling material, the intermediate body IB is held by the holding unit 600, so that modeling can be performed stably on the back side.

[0058] In the third embodiment, the manufacturing system 102 includes the modeling unit 200, but may include a cutting unit 250. In this case, a three-dimensional object can be manufactured by cutting the back side of a part manufactured by the injection molding machine 700. The intermediate IB is not limited to being manufactured by the injection molding machine 700, and may be a part manufactured by another manufacturing device.

[0059] D. Other embodiments: (D1) In each of the above embodiments, the holding unit 600 is fixed on the stage 300. Alternatively, the holding unit 600 may be provided on a robot as an end effector. In this case, the intermediate IB modeled on the stage 300 or the intermediate IB manufactured by the injection molding machine 700 is attracted and held by the holding unit 600 provided on the robot, and is disposed so that the back surface of the intermediate IB faces the modeling unit 200 or the cutting unit 250. Then, in this state, cutting or modeling is performed on the back surface of the intermediate IB. In this way, if the holding unit 600 is provided on the robot, a three-dimensional object can be manufactured without performing an operation of fixing the holding unit 600 to the stage 300.

[0060] (D2) The manufacturing system may perform modeling on the back side of the intermediate IB by the modeling unit 200, and then cut a part of the part modeled on the back side of the intermediate IB by the cutting unit 250. In other words, both the modeling unit 200 and the cutting unit 250 may be used in processing the back side of the intermediate IB produced by the above-mentioned manufacturing system or injection molding machine. With this configuration, it is possible to increase the degree of freedom in the shape of the back side of the intermediate IB.

[0061] (D3) In each of the above embodiments, the plasticizing section 30 includes a flat screw 40 and a barrel 50. In contrast, the plasticizing section 30 may include an in-line screw instead of the flat screw 40, and the material may be plasticized by rotating the in-line screw to produce a plasticized material. In this case, the barrel is formed in a cylindrical shape to accommodate the in-line screw, and may also be called a cylinder.

[0062] (D4) In each of the above embodiments, the manufacturing system includes one modeling unit 200. In contrast, the manufacturing system may include two or more modeling units 200. In this way, different types of modeling materials can be ejected from each modeling unit 200.

[0063] E. Other forms: The present disclosure is not limited to the above-mentioned embodiment, and can be realized in various configurations without departing from the spirit of the present disclosure. For example, the technical features of the embodiments corresponding to the technical features in each form described below can be appropriately replaced or combined in order to solve some or all of the above-mentioned problems or to achieve some or all of the above-mentioned effects. Furthermore, if a technical feature is not described as essential in this specification, it can be appropriately deleted.

[0064] (1) According to a first aspect of the present disclosure, there is provided a system for manufacturing a three-dimensional object, the system for manufacturing a three-dimensional object including a processing unit having at least one of a modeling unit that ejects modeling material from a nozzle and stacks the material and a cutting unit having a cutting tool, a holding unit that holds an intermediate body that will become the three-dimensional object in a state where the back surface of the intermediate body, which is the surface opposite to the front surface formed on the intermediate body, faces the processing unit, and a control unit, the holding unit has a sensor that detects a force received from the intermediate body, the control unit controls the processing unit to process the back surface side of the intermediate body in accordance with processing conditions while the intermediate body is held by the holding unit, thereby manufacturing the three-dimensional object, and the control unit changes the processing conditions in accordance with the value of the force detected by the sensor. According to this embodiment, by holding the intermediate body with the holding part, the back side of the intermediate body can be processed to produce a three-dimensional object. Furthermore, since the processing conditions can be changed according to the force received from the intermediate body by the sensor provided in the holding part, the back side of the intermediate body can be processed with high precision.

[0065] (2) In the above embodiment, the holding section may include a plurality of rod-shaped hollow members arranged in parallel to each other, a first support having a plurality of first through holes formed therein, the hollow members passing through the first through holes, and a second support disposed opposite the first support, the second support having a plurality of second through holes formed at positions corresponding to the plurality of first through holes, the hollow members passing through the second through holes, the first through holes having a gap portion in which a gap between the hollow members and the first support becomes larger toward the second support, and a fixing member is disposed in the gap portion, and the holding section may hold the intermediate body by bringing the tips of the plurality of hollow members into contact with the intermediate body, and then pushing the fixing member into the gap portion by bringing the second support and the first support closer to each other, and sucking the intermediate body through the hollow members using a suction device. According to this embodiment, the intermediate body can be well adsorbed and held even if the back side of the intermediate body has a curved surface or unevenness.

[0066] (3) In the above embodiment, the processing unit may include the cutting unit, the processing step may be a step of cutting the back surface side of the intermediate body with the cutting tool, and the control unit may reduce the cutting amount per unit time by the cutting tool, which is the processing condition, when the value exceeds a predetermined threshold value during the processing step. According to this embodiment, it is possible to prevent the intermediate body from peeling off from the holding unit due to a force applied to the intermediate body by the cutting tool when the back surface side of the intermediate body is cut.

[0067] (4) In the above embodiment, the control unit may reduce the cutting amount per unit time by adjusting at least one of the feed speed and the rotation speed of the cutting tool without adjusting the cutting depth of the cutting tool during the cutting pass of the cutting tool. According to this embodiment, it is possible to prevent a step from being generated in the cutting portion during the cutting pass.

[0068] (5) In the above embodiment, the control unit may at least correct the next cutting pass so as to reduce the cutting amount per unit time by reducing the cutting depth by the cutting tool. According to this embodiment, since the cutting depth is reduced after the cutting pass is switched, it is possible to prevent a step from being generated in the cutting portion during the cutting pass.

[0069] (6) In the above embodiment, the intermediate body may be prevented from peeling off from the holding unit when the intermediate body is laminated with the molding material on the back surface by controlling the molding unit, and the control unit may change the heating temperature of the heating unit, which is the processing condition, in accordance with the force value detected by the sensor.

[0070] (7) In the above embodiment, the holding unit may have the sensor for each hollow member, the heating unit may have a plate shape and include a plurality of heating areas, and the temperature of each heating area may be individually adjustable, and the control unit may increase the heating temperature of the heating area corresponding to the position of the hollow member corresponding to the sensor where the value exceeded a predetermined threshold during the processing, higher than the heating temperature before the value exceeded the threshold. According to this embodiment, a portion of the intermediate body that is likely to peel off from the holding unit can be locally heated to prevent the portion from peeling off.

[0071] (8) In the above embodiment, the intermediate body may be a part manufactured by an injection molding machine, the processing unit may have the modeling unit, and the processing step may be a step of controlling the modeling unit to laminate the modeling material on the back surface. According to this embodiment, a three-dimensional object can be manufactured by modeling the back surface side of the part manufactured by the injection molding machine.

[0072] The present disclosure is not limited to the above-described three-dimensional object manufacturing system, and can be realized in various forms, such as a three-dimensional object manufacturing apparatus and a three-dimensional object manufacturing method. [Explanation of symbols]

[0073] 20...material supply section, 22...supply path, 30...plasticization section, 31...screw case, 32...driving motor, 40...flat screw, 41...upper surface, 42...groove forming surface, 43...side surface, 44...material inlet, 45...groove section, 46...ridge section, 47...center section, 50...barrel, 52...screw facing surface, 54...guide groove, 56...communicating hole, 58...first heating section, 60...discharge section, 61...nozzle, 62...nozzle opening, 63...discharge adjustment section, 65...flow path, 70...second heating section, 100...manufacturing system, 1 Reference Signs List 01... manufacturing system, 102... manufacturing system, 200... molding section, 250... cutting section, 260... cutting tool, 300... stage, 310... molding surface, 400... moving mechanism, 500... control section, 501... data generation section, 600... holding section, 610... hollow member, 611... contact member, 612... tube, 620... first support, 621... first through hole, 622... gap, 630... second support, 631... second through hole, 640... fixing member, 650... sensor, 660... suction device, 700... injection molding machine

Claims

1. A manufacturing system for a three-dimensional object, comprising: A processing unit having at least one of a modeling unit that ejects modeling material from a nozzle and stacks the material, and a cutting unit that has a cutting tool; a holding part that holds the intermediate body in a state where a back surface of the intermediate body that will become the three-dimensional object, the back surface being a surface opposite to the front surface formed on the intermediate body, faces the processing part; and A control unit, the holding portion has a sensor that detects a force received from the intermediate body, the control unit executes a processing process for processing the back surface side of the intermediate body by controlling the processing unit in accordance with processing conditions while the intermediate body is held by the holding unit, thereby manufacturing the three-dimensional object; The control unit changes the processing conditions in response to the value of the force detected by the sensor. A manufacturing system for three-dimensional objects.

2. The system for manufacturing a three-dimensional object according to claim 1, The holding portion is A plurality of rod-shaped hollow members arranged in parallel to each other; a first support body having a plurality of first through holes formed therein, the hollow member passing through the first through holes; a second support disposed opposite the first support, the second support having a plurality of second through holes formed at positions corresponding to the plurality of first through holes, the hollow member passing through the second through holes; the first through hole has a gap portion in which a gap between the first through hole and the hollow member becomes larger toward the second support, A fixing member is disposed in the gap, the holding section brings the tips of the plurality of hollow members into contact with the intermediate body, and then brings the second support and the first support closer to each other to push the fixing member into the gap, thereby fixing the hollow members to the first support, and holds the intermediate body by sucking the intermediate body through the hollow members using a suction device. A manufacturing system for three-dimensional objects.

3. The system for manufacturing a three-dimensional object according to claim 1, The processing unit includes the cutting unit, the processing step is a step of cutting the back surface side of the intermediate body with the cutting tool, The control unit of the system for manufacturing three-dimensional objects is configured to reduce the amount of cutting per unit time by the cutting tool, which is one of the processing conditions, when the value exceeds a predetermined threshold during the processing.

4. The system for manufacturing a three-dimensional object according to claim 3, The control unit does not adjust the cutting depth of the cutting tool during the cutting pass of the cutting tool, but reduces the cutting amount per unit time by adjusting at least one of the feed speed of the cutting tool and the rotational speed of the cutting tool.

5. The system for manufacturing a three-dimensional object according to claim 3, The control unit reduces the cutting amount per unit time by at least correcting a next cutting pass so as to reduce an amount of cutting by the cutting tool.

6. The system for manufacturing a three-dimensional object according to claim 1, A heating unit for heating the intermediate body is provided, The processing unit has the shaping unit, the processing step is a step of stacking the modeling material on the back surface by controlling the modeling unit; The control unit changes the heating temperature by the heating unit, which is one of the processing conditions, in accordance with the force value detected by the sensor.

7. The system for manufacturing a three-dimensional object according to claim 6, the holding unit has a sensor for each of the hollow members, The heating unit has a plate-like shape, includes a plurality of heating areas, and is configured to be able to individually adjust the temperature of each of the heating areas; The control unit increases the heating temperature of the heating area corresponding to the position of the hollow member corresponding to the sensor where the value exceeded a predetermined threshold during the processing, higher than the heating temperature before the value exceeded the threshold.

8. The system for manufacturing a three-dimensional object according to claim 1, the intermediate product is a part manufactured by an injection molding machine; The processing unit has the shaping unit, The processing is a process of controlling the modeling unit to laminate the modeling material on the back surface.

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