Three-dimensional shaping device

Abstract

To achieve suppression of collapse of a shape of a three-dimensional molded article, and improvement in adhesion between layers.SOLUTION: A three-dimensional molding device includes: a stage having a molding surface on which a molding material is stacked; a discharge part for discharging the molding material toward a molding region on the molding surface; a position changing part for changing a relative position between the discharge part and the stage; a first heating part which is configured to change a relative position between the stage and the first heating part together with the discharge part, covers the molding region when viewed in a stacking direction of the molding material at a position opposite to the molding surface, and heats the molding material stacked on the molding region; and a control part for controlling the discharge part, the first heating part and the position changing part, so as to stack the layers of the molding material on the molding region and molding a three-dimensional molded article. When molding the three-dimensional molded article, the control part controls the first heating part on the basis of an opposing distance indicating a distance between the stage and the first heating part in the stacking direction.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a three-dimensional shaping apparatus.

Background Art

[0002] Regarding three-dimensional shaping apparatuses, Patent Document 1 discloses an apparatus for shaping a three-dimensional object by laminating a material extruded from a discharge unit onto a stage disposed within a heated chamber.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the three-dimensional shaping apparatus of Patent Document 1, when the temperature inside the chamber is increased to improve the adhesion between a newly shaped layer and the previous layer, the temperature of the entire shaped object may increase and the shape of the shaped object may collapse. Therefore, the inventors of the present application attempted to preferentially heat the upper layer of the shaped object by using a heater configured to cover the entire shaping area at a position facing the stage and to change the relative position with respect to the stage together with the discharge unit. On the other hand, when such a heater is used, as the layers are laminated, the heater and the stage move apart. Therefore, if the output of the heater is kept constant, when laminating the lower layers, the amount of heat supplied from the heater and the heated stage to the shaped object may become excessive and the temperature of the shaped object may become too high, and when laminating the upper layers, the inventors of the present application have found that the amount of heat supplied to the shaped object may be insufficient and the temperature of the shaped object may become too low.

Means for Solving the Problems

[0005] According to one embodiment of the present disclosure, a three-dimensional molding apparatus is provided. The three-dimensional molding apparatus comprises a stage having a molding surface on which a molding material is stacked; an ejection unit for ejecting the molding material toward a molding region on the molding surface; a position change unit for changing the relative position between the ejection unit and the stage; a first heating unit configured to change its relative position with the stage together with the ejection unit, and which, at a position facing the molding surface, covers the molding region when viewed along the stacking direction of the molding material, and heats the molding material stacked in the molding region; and a control unit that controls the ejection unit, the first heating unit, and the position change unit to stack layers of the molding material in the molding region and mold a three-dimensional object. When molding the three-dimensional object, the control unit controls the first heating unit based on a facing distance, which represents the distance between the stage and the first heating unit in the stacking direction. [Brief explanation of the drawing]

[0006] [Figure 1] This is the first figure showing the schematic configuration of the three-dimensional molding apparatus in the first embodiment. [Figure 2] This is a second figure showing the schematic configuration of the three-dimensional printing apparatus in the first embodiment. [Figure 3] This is a perspective view showing the general configuration of the lower side of the screw. [Figure 4] This is a schematic plan view showing the top side of the barrel. [Figure 5] This is the first schematic diagram showing an example of the positional relationship between the first heating section and the stage. [Figure 6] This is a second schematic diagram showing an example of the positional relationship between the first heating section and the stage. [Figure 7] The first figure schematically illustrates how a three-dimensional object is created. [Figure 8] The second figure schematically illustrates how a three-dimensional object is created. [Figure 9] This is a flowchart of the three-dimensional fabrication process in the first embodiment. [Figure 10]This figure shows the schematic configuration of the three-dimensional molding apparatus in the second embodiment. [Figure 11] This is a flowchart of the three-dimensional fabrication process in the second embodiment. [Figure 12] This figure shows the schematic configuration of the three-dimensional molding apparatus in the third embodiment. [Figure 13] This is a flowchart of the three-dimensional fabrication process in the third embodiment. [Figure 14] This is a flowchart of the three-dimensional fabrication process in the fourth embodiment. [Modes for carrying out the invention]

[0007] A. First Embodiment: Figure 1 is a first diagram showing the schematic configuration of the three-dimensional molding apparatus 100 in the first embodiment. Figure 2 is a second diagram showing the schematic configuration of the three-dimensional molding apparatus 100 in the first embodiment. Figures 1 and 2 show arrows along the mutually orthogonal X, Y, and Z directions. The X, Y, and Z directions are directions along the three mutually orthogonal spatial axes, the X-axis, Y-axis, and Z-axis, and include both the direction along one side of the X-axis, Y-axis, and Z-axis, and the opposite direction, respectively. The X-axis and Y-axis are axes along the horizontal plane, and the Z-axis is an axis along the vertical line. In the following description, when specifying a direction, a positive direction will be represented by "+" and a negative direction by "-", and positive and negative signs will be used in the direction notation. The -Z direction is the vertical direction, and the +Z direction is the direction opposite to the vertical direction. The -Z direction is also called "down", and the +Z direction is also called "up". In other figures as well, arrows along the X, Y, and Z directions are shown where appropriate. The X, Y, and Z directions in Figures 1 and 2 represent the same directions as those in the other figures. Furthermore, in this specification, orthogonal includes the range of 90° ± 10°.

[0008] The three-dimensional molding apparatus 100 comprises an ejection unit 200, a stage 300, a position change unit 400, a control unit 500, a first heating unit 600, and a second heating unit 700. Note that in Figure 2, the head movement mechanism 410 of the position change unit 400, which will be described later, is omitted.

[0009] The discharge unit 200, under the control of the control unit 500, melts a solid material into a paste and discharges the resulting material onto the molding stage 300, which serves as the base for a three-dimensional object. As shown in Figures 1 and 2, the discharge unit 200 comprises a material storage unit 20 for storing material to generate the molding material, a plasticizing unit 30 for plasticizing the material supplied from the material storage unit 20 to generate the molding material, and a nozzle 61 for discharging the generated molding material. The discharge unit 200 is sometimes referred to as the head.

[0010] The material storage section 20 contains materials in the form of pellets or powder. In this embodiment, ABS resin formed into pellets is used as the material. In this embodiment, the material storage section 20 is composed of a hopper. As shown in Figure 2, a supply passage 22 is provided below the material storage section 20, connecting the material storage section 20 and the plasticizing section 30. The material storage section 20 supplies material to the plasticizing section 30 via the supply passage 22.

[0011] As shown in Figure 2, the plasticizing unit 30 comprises a screw case 31, a drive motor 32, a screw 40, and a barrel 50. The plasticizing unit 30 plasticizes at least a portion of the material supplied from the material storage unit 20, generating a fluid paste-like molding material which is then supplied to the nozzle 61. "Plasticization" is a concept that includes melting and refers to changing a solid state to a fluid state. Specifically, in the case of materials that undergo a glass transition, plasticization means raising the temperature of the material above the glass transition point. In the case of materials that do not undergo a glass transition, plasticization means raising the temperature of the material above the melting point.

[0012] FIG. 3 is a perspective view showing a schematic configuration on the side of the screw bottom surface 42 of the screw 40. FIG. 4 is a schematic plan view showing the side of the barrel upper surface 52 which is the upper surface of the barrel 50. The screw 40 has a substantially cylindrical shape with a height in the axial direction, which is the direction along its central axis RX, smaller than the diameter. The screw 40 is arranged such that its central axis RX serving as the rotation center is parallel to the Z direction.

[0013] As shown in FIG. 2, the screw 40 is housed in the screw case 31. The side of the screw upper surface 41 of the screw 40 is connected to the drive motor 32, and the screw 40 rotates in the screw case 31 by the rotational driving force generated by the drive motor 32. The drive motor 32 operates under the control of the control unit 500. Note that the screw 40 may be driven by the drive motor 32 via a speed reducer.

[0014] As shown in FIG. 3, a spiral groove portion 45 is formed on the screw bottom surface 42. The supply path 22 of the material storage portion 20 described above communicates with the groove portion 45 from the side surface of the screw 40. The groove portion 45 continues to a material inlet 44 formed on the side surface of the screw 40. This material inlet 44 is a portion for receiving the material supplied through the supply path 22 of the material storage portion 20. As shown in FIG. 3, in the present embodiment, the groove portion 45 is formed in three sections separated by ridge portions 46. Note that the number of the groove portions 45 is not limited to three, and may be one, or two or more. The groove portion 45 is not limited to a spiral shape, and may be a helical shape or an involute curve shape, or may be a shape extending in an arc from the central portion 47 toward the outer periphery.

[0015] As shown in FIG. 2, the barrel 50 is disposed below the screw 40. The upper surface 52 of the barrel faces the lower surface 42 of the screw, and a space is formed between the groove 45 of the lower surface 42 of the screw and the upper surface 52 of the barrel. The barrel 50 is provided with a communication hole 56 that communicates with the nozzle passage 65 of a nozzle 61 described later on the central axis RX of the screw 40. The barrel 50 has a plasticizing heater 58 built in at a position facing the groove 45 of the screw 40. The temperature of the plasticizing heater 58 is controlled by the control unit 500.

[0016] As shown in FIG. 4, a plurality of guide grooves 54 are formed around the communication hole 56 on the upper surface 52 of the barrel. Each guide groove 54 has one end connected to the communication hole 56 and extends spirally from the communication hole 56 toward the outer periphery of the upper surface 52 of the barrel. Each guide groove 54 has a function of guiding the modeling material to the communication hole 56. Note that one end of the guide groove 54 may not be connected to the communication hole 56. Also, the barrel 50 may not have the guide groove 54 formed therein.

[0017] The material supplied into the groove 45 of the screw 40 melts in the groove 45 and flows along the groove 45 by the rotation of the screw 40, and is guided as a modeling material to the central portion 47 of the screw 40. The paste-like modeling material that has flowed into the central portion 47 and exhibits fluidity is supplied to the nozzle 61 through the communication hole 56. Note that not all types of substances constituting the modeling material need to be melted, and as long as at least some types of substances constituting the modeling material are melted and the modeling material is converted into a state having fluidity as a whole.

[0018] As shown in Figure 2, the nozzle 61 comprises a nozzle channel 65 and a tip surface 63 on which a nozzle opening 62 is provided. The nozzle channel 65 is a channel for the molding material formed inside the nozzle 61 and is connected to the communication hole 56 of the barrel 50 described above. The tip surface 63 is the surface that constitutes the tip portion of the nozzle 61 that protrudes in the -Z direction toward the stage 300. The nozzle opening 62 is a portion of the nozzle channel 65 where the cross-section of the channel is reduced, provided at the end of the nozzle channel 65 that communicates with the atmosphere. The molding material generated by the plasticizer 30 is supplied to the nozzle 61 via the communication hole 56 and discharged from the nozzle opening 62 via the nozzle channel 65.

[0019] The stage 300 is positioned opposite the tip surface 63 of the nozzle 61. The three-dimensional molding apparatus 100 extrudes molding material from the nozzle opening 62 of the nozzle 61 toward the molding area on the molding surface 311 of the stage 300, and builds a three-dimensional object by stacking layers of molding material in the molding area. The molding surface 311 is the surface of the stage 300 on which the molding material is deposited, and is composed of at least a part of the upper surface of the stage 300. The molding area refers to the area in which the three-dimensional object is built, which is composed of the molding surface 311 and the area above the molding surface 311. In this embodiment, the molding surface 311 is positioned parallel to the X and Y directions. The direction in which the molding material is stacked is sometimes called the stacking direction. The stacking direction includes both the direction along the same axis and the opposite direction, and in this embodiment, it is the direction along the Z direction.

[0020] The position changing unit 400 changes the relative position between the discharge unit 200 and the stage 300. As shown in Figures 1 and 2, the position changing unit 400 in this embodiment includes a head moving mechanism 410 that moves the discharge unit 200 relative to the stage 300, and a stage moving mechanism 420 that moves the stage 300 relative to the discharge unit 200. In this embodiment, the head moving mechanism 410 moves the discharge unit 200 along the Z direction relative to the stage 300. The stage moving mechanism 420 moves the stage 300 along the X and Y directions relative to the discharge unit 200. The head moving mechanism 410 shown in Figure 1 is composed of a lifting device that moves the discharge unit 200 along the Z direction while supporting it, and has a motor for moving the discharge unit 200 along the Z direction. The stage moving mechanism 420 shown in Figures 1 and 2 is composed of a horizontal transport device that moves the stage 300 along the X and Y directions while supporting it, and has a motor for moving the stage 300 along the X direction and a motor for moving the stage 300 along the Y direction. The head moving mechanism 410 and the stage moving mechanism 420 are driven under the control of the control unit 500.

[0021] In the following, the change in the relative position of the discharge unit 200 with respect to the stage 300 may simply be referred to as the movement of the discharge unit 200. In this embodiment, for example, moving the stage 300 in the +X direction relative to the discharge unit 200 can be rephrased as moving the discharge unit 200 in the -X direction. Similarly, the change in the relative positions of the nozzle 61, the first heating unit 600, and the second heating unit 700 with respect to the stage 300 may simply be referred to as the movement of the nozzle 61, the first heating unit 600, and the second heating unit 700. In other embodiments, for example, the stage moving mechanism 420 may move the stage 300 in the Z direction relative to the discharge unit 200, and the head moving mechanism 410 may move the discharge unit 200 along the X and Y directions relative to the stage 300. Alternatively, the stage moving mechanism 420 may move the stage 300 in the X, Y, and Z directions relative to the discharge unit 200. In this case, the position change unit 400 does not need to have a head moving mechanism unit 410. Similarly, the head moving mechanism unit 410 may move the discharge unit 200 relative to the stage 300 in the X, Y, and Z directions. In this case, the position change unit 400 does not need to have a stage moving mechanism unit 420.

[0022] The first heating unit 600 shown in Figures 1 and 2 is positioned opposite the build surface 311 of the stage 300 and heats the build material stacked in the build area on the build surface 311. In this embodiment, the first heating unit 600 is positioned around the nozzle 61 and fixed to the extrusion unit 200 via a support unit 205 similarly positioned around the nozzle 61. In this embodiment, the first heating unit 600 and the support unit 205 have a rectangular plate-like outer shape. The first heating unit 600 and the support unit 205 are positioned parallel to the build surface 311. A through hole 206 through which the nozzle 61 is inserted is provided in the center of the support unit 205. The first heating unit 600 is configured to change its relative position to the stage 300 together with the extrusion unit 200. More specifically, in this embodiment, the first heating unit 600 moves in accordance with the extrusion unit 200, which is moved by the position-changing unit 400.

[0023] In this embodiment, the first heating section 600 is composed of heaters. The heaters constituting the first heating section 600 may be, for example, rubber heaters, halogen heaters, nichrome wire heaters, carbon heaters, or heaters that blow out hot air. Furthermore, the number of heaters constituting the first heating section 600 may be one or two or more.

[0024] The first heating unit 600 is configured to cover the build surface 311 of the stage 300 when viewed along the Z direction. More specifically, the first heating unit 600 is configured to cover the build surface 311 when viewed along the Z direction, regardless of how the relative position between the first heating unit 600 and the stage 300 is changed by the position changing unit 400.

[0025] Figure 5 is a first schematic diagram showing an example of the positional relationship between the first heating unit 600 and the stage 300. Figure 6 is a second schematic diagram showing an example of the positional relationship between the first heating unit 600 and the stage 300. Figure 5 shows the configuration when the discharge unit 200 is positioned furthest in the -X direction relative to the stage 300 in this embodiment. Figure 6 shows the configuration when the discharge unit 200 is positioned furthest in the +X direction relative to the stage 300. In Figures 5 and 6, the range Mx in the X direction of the molding area in this embodiment is indicated by a solid arrow. In the example in Figure 5, the nozzle opening 62 of the nozzle 61 is positioned to coincide with the -X end of the range Mx when viewed along the Z direction. In the example in Figure 6, the nozzle opening 62 is positioned to coincide with the +X end of the range Mx when viewed along the Z direction. In Figures 5 and 6, one end Eg1 and the other end Eg2 of the first heating unit 600 in the X direction are indicated by dashed lines, respectively.

[0026] As shown in Figures 5 and 6, the range Mx of the build area in the X direction is located between one end Eg1 and the other end Eg2 of the first heating unit 600, regardless of how the relative position of the first heating unit 600 and the stage 300 in the X direction is changed by the position change unit 400. In other words, the build area is located between one end Eg1 and the other end Eg2 of the first heating unit 600, regardless of how the relative position of the first heating unit 600 and the stage 300 in the X direction is changed by the position change unit 400. It can also be said that the build area is configured to be located inside the outer edge of the first heating unit 600 in the X direction. Similarly, although not shown in the figures, the build area is also configured to be located inside the outer edge of the first heating unit 600 in the Y direction.

[0027] The second heating section 700 heats the stage 300. In this embodiment, the second heating section 700 is composed of a rectangular plate-shaped heater and is provided on the stage 300. More specifically, the second heating section 700 is embedded in the stage 300 and is positioned in the -Z direction of the molding surface 311. The heater constituting the second heating section 700 may be, for example, a halogen heater, a nichrome wire heater, or a carbon heater. Furthermore, the number of heaters constituting the second heating section 700 may be one or two or more.

[0028] The control unit 500 shown in Figures 1 and 2 is a control device that controls the operation of the entire three-dimensional molding apparatus 100. The control unit 500 is composed of a computer equipped with one or more processors, memory, and an input / output interface for inputting and outputting signals to and from the outside. The control unit 500 performs various functions, such as executing three-dimensional molding processing, by having the processor execute programs and instructions loaded into the main memory. Alternatively, instead of being composed of a computer, the control unit 500 may be realized by a configuration that combines multiple circuits to realize at least some of each function.

[0029] Figure 7 is the first schematic diagram showing how the three-dimensional object OB is fabricated by the three-dimensional fabrication process. Figure 7 shows the eighth layer L8 of the three-dimensional object OB in the process of being fabricated. In the fabrication process, the control unit 500 appropriately controls the extrusion unit 200 and the position change unit 400 described above according to the fabrication data described later, to extrude the fabrication material from the nozzle opening 62 of the nozzle 61 toward the stage 300, and fabricates the three-dimensional object OB by solidifying the fabrication material on the fabrication surface 311 and stacking layers of the fabrication material in the Z direction. Solidification of the material refers to the loss of fluidity of the extruded fabrication material. In this embodiment, the fabrication material solidifies as its temperature decreases, causing thermal shrinkage and loss of plasticity.

[0030] More specifically, as shown in Figure 7, the control unit 500 extrudes the molding material from the nozzle 61 while moving the nozzle 61 in the X and Y directions during the three-dimensional molding process. As the molding material extruded from the nozzle 61 is continuously deposited in the direction of the nozzle 61's movement, linear portions are formed that extend linearly along the movement path of the nozzle 61. The control unit 500 forms layers ML by repeatedly forming these linear portions through scanning of the nozzle 61. After forming one layer ML, the control unit 500 moves the position of the nozzle 61 relative to the stage 300 in the Z direction and builds the object by stacking more layers ML on top of the layers ML that have been formed so far. Therefore, during the molding process, the extrusion unit 200 and the nozzle 61 are closest to the molding surface 311 when the first layer L1, which is the first layer of the three-dimensional object OB, is being built, and then move away from the molding surface 311 as higher layers are stacked. In the following, when n is an arbitrary natural number, the nth layer of the three-dimensional object OB may be referred to as the nth layer.

[0031] When stacking each layer, the control unit 500 extrudes the molding material from the nozzle 61 of the extrusion unit 200 while maintaining the distance between the nozzle 61 and the extrusion target. The extrusion target is the molding surface 311 when extruding the molding material onto the molding surface 311, and the upper surface of the already extruded molding material when extruding the molding material onto already extruded molding material. The distance between the nozzle 61 and the extrusion target is sometimes called the gap Gp.

[0032] In the three-dimensional molding process, when the nth layer is being deposited, the control unit 500 controls the first heating unit 600 to heat the molding material constituting the (n-1)th layer, which is a layer already deposited in the molding area on the stage 300, while extruding the molding material onto the (n-1)th layer. In this way, the control unit 500 deposits the nth layer on top of the (n-1)th layer while maintaining the temperature of the (n-1)th layer at a temperature that improves interlayer adhesion between the nth layer and the (n-1)th layer. Furthermore, when depositing the nth layer, it is preferable that the temperature of the layers below the (n-1)th layer be maintained at a temperature that maintains the shape of the layers. The temperature that maintains the shape of the layers is lower than the temperature that improves interlayer adhesion. In this embodiment, the first heating unit 600 is positioned opposite the molding surface 311 and is configured to cover the molding surface 311 when viewed along the Z direction. Therefore, while heating the entire molding material stacked in the molding area, it is possible to preferentially heat the upper layers of the three-dimensional molded object OB, such as the top layer. As a result, it is easy to achieve both the maintenance of the layer shape and improved interlayer adhesion.

[0033] More specifically, the control unit 500 controls the first heating unit 600 in the three-dimensional printing process based on the opposing distance, which represents the distance between the stage 300 and the first heating unit 600 in the Z direction. In this embodiment, the control unit 500 performs a first control in the three-dimensional printing process, setting the temperature of the first heating unit 600 to a first set temperature when the opposing distance is a first distance, and setting the temperature of the first heating unit 600 to a second set temperature which is higher than the first set temperature when the opposing distance is a second distance which is longer than the first distance.

[0034] Figure 8 is a second diagram schematically showing how the three-dimensional object OB is fabricated by the three-dimensional fabrication process. Figure 8 shows the process of fabricating the ninth layer L9 of the three-dimensional object OB. As shown in Figure 7, if the opposing distance when fabricating the eighth layer L8 is denoted as distance D1, and as shown in Figure 8, if the opposing distance when fabricating the ninth layer L9 is denoted as distance D2, then distance D2 is longer than distance D1. Then, as shown in Figure 8, when fabricating the ninth layer L9, the control unit 500 sets the set temperature of the first heating unit 600 to be higher than the set temperature when fabricating the eighth layer L8, as shown in Figure 7. In other words, in the examples of Figures 7 and 8, distance D1 corresponds to the first distance described above, and distance D2 corresponds to the second distance described above. Furthermore, the set temperature of the first heating unit 600 when the eighth layer L8 is being fabricated corresponds to the first set temperature described above, and the set temperature of the first heating unit 600 when the ninth layer L9 is being fabricated corresponds to the second set temperature.

[0035] In the example in Figure 7, compared to the example in Figure 8, the opposing distance is shorter, so heat from the first heating unit 600 is more easily transferred to the stage 300, and the space between the first heating unit 600 and the stage 300 is smaller. Also, because there are fewer existing layers, the amount of heat required to heat the existing layers is small. Conversely, in the example in Figure 9, compared to the example in Figure 7, heat from the first heating unit 600 is less easily transferred to the stage 300, and the space between the first heating unit 600 and the stage 300 is larger. Also, because there are more existing layers, the amount of heat required to heat the existing layers is large. Therefore, if the output of the first heating unit 600 is kept constant, for example, regardless of the opposing distance, when there are fewer existing layers, the amount of heat supplied to the three-dimensional object OB will be excessive, and there is a risk that the temperature of the three-dimensional object will become too high, causing the shape of the three-dimensional object OB to collapse. Similarly, when there are many existing layers, the amount of heat supplied to the three-dimensional object OB may be insufficient, causing the temperature of the three-dimensional object OB to become too low. In this case, for example, the heat from the top layer may be absorbed by the layers below it, potentially reducing the adhesion between layers, or deformation such as warping due to rapid cooling may occur in layers that are less affected by the heat from the first heating unit 600 and the stage 300, such as layers near the middle in the stacking direction of the three-dimensional object OB. In this embodiment, as described above, the first heating unit 600 is controlled based on the opposing distance, so such deformation of the shape of the three-dimensional object OB, reduction in interlayer adhesion, and deformation due to rapid cooling can be suppressed.

[0036] In this embodiment, the control unit 500 controls the second heating unit 700 in addition to the first heating unit 600 during the three-dimensional molding process. By controlling the second heating unit 700 in addition to the first heating unit 600 during the three-dimensional molding process, the three-dimensional object OB being molded within the molding area can be heated from the stage 300 side in the Z direction. In other words, the three-dimensional object OB can be heated not only from above but also from below, so even if there are many existing layers, for example, deformation due to rapid cooling of the lower layers of the three-dimensional object OB can be suppressed. Furthermore, the amount of heat supplied to the three-dimensional object from above can be controlled by the first heating unit 600, and the amount of heat supplied to the three-dimensional object from below via the stage 300 can be controlled by the second heating unit 700. Therefore, for example, it becomes easier to control the temperature of the uppermost layer to maintain a temperature that improves interlayer adhesion, while maintaining the temperature of the layers below the uppermost layer to maintain the shape of the layers.

[0037] In this embodiment, the control unit 500 controls the first heating unit 600 in the three-dimensional printing process based not only on the distance to the heating unit but also on the set temperature of the second heating unit 700. When the control unit 500 controls the second heating unit 700 in the three-dimensional printing process, the temperature of the stage 300 changes due to the heat from the second heating unit 700. Therefore, by controlling the first heating unit 600 based not only on the distance to the heating unit but also on the set temperature of the second heating unit 700, the temperature of the three-dimensional object being printed can be controlled more appropriately. It is preferable that the control unit 500 controls the first heating unit 600 and the second heating unit 700 so that the temperature of the stage 300 does not exceed the heat resistance temperature of the motor and other components that constitute the stage moving mechanism 420.

[0038] In this embodiment, the control unit 500 sets the set temperature of the first heating unit 600 to a higher temperature than the set temperature of the second heating unit 700, regardless of how the distance between them changes. Therefore, it is easier to control the temperature of the uppermost layer to maintain an improved interlayer adhesion temperature while maintaining the temperature of the layers below the uppermost layer to maintain the layer shape, as described above. In addition, since the temperature of the layers near the middle in the lamination direction, which are far from both the first heating unit 600 and the second heating unit 700, can be increased, deformation due to rapid cooling in these intermediate layers can be suppressed. In other embodiments, the control unit 500 may set the set temperature of the first heating unit 600 to a higher temperature than the set temperature of the second heating unit 700, or it may set it to the same temperature as the set temperature of the second heating unit 700.

[0039] Figure 9 is a flowchart of the three-dimensional modeling process in this embodiment. This three-dimensional modeling process is executed, for example, when the control unit 500 receives a predetermined start operation from the user.

[0040] In step S110, the control unit 500 acquires the molding data. In this embodiment, in step S110, the control unit 500 acquires the molding data from an external computer, recording medium, etc.

[0041] The build data includes build path data representing the movement path of the nozzle 61 for each layer forming the three-dimensional object. The build path data is associated with discharge amount data representing the amount of material discharged from the nozzle 61. In this embodiment, the discharge amount represented by the discharge amount data is the amount of build material discharged per unit time along that movement path. The build data is generated, for example, based on layer data obtained by slicing the shape of the three-dimensional object into layers. The layer data is generated, for example, based on shape data representing the shape of the three-dimensional object. In other embodiments, for example, the total amount of build material discharged along the entire movement path may be associated with each movement path as discharge amount data.

[0042] In step S120, the control unit 500 determines the set temperature of the second heating unit 700. In this embodiment, in step S120, the control unit 500 sets the set temperature of the second heating unit 700 to, for example, a temperature specified by the user.

[0043] In step S130, the control unit 500 acquires the opposing distance. In this embodiment, in step S130, the control unit 500 acquires the Z coordinate representing the coordinate of the nozzle 61 in the Z direction based on the control value of the head movement mechanism 410, and acquires the opposing distance by calculating the distance between the build surface 311 and the lower surface of the first heating unit 600 as the opposing distance based on the acquired Z coordinate. For example, when step S130 is executed for the first time, the distance between the build surface 311 and the first heating unit 600 when the first layer of the three-dimensional object is built is acquired as the opposing distance.

[0044] In step S140, the control unit 500 determines the set temperature of the first heating unit 600. In this embodiment, in step S140, the control unit 500 determines the set temperature of the first heating unit 600 based on the opposing distance obtained in step S130 and the set temperature of the second heating unit 700 determined in step S120, using a predetermined relationship between the opposing distance and the set temperature of the first heating unit 600 for each set temperature of the second heating unit 700. In this embodiment, the relationship between the opposing distance and the set temperature of the first heating unit 600 used in step S140 is represented by a monotonically increasing function that defines the relationship between the opposing distance and the set temperature of the first heating unit 600 for each set temperature of the second heating unit 700. This function is determined experimentally, for example, as a function to achieve the above-mentioned improvement in interlayer adhesion and suppression of collapse of the layer shape regardless of the number of existing layers. In this embodiment, this function is defined such that the set temperature of the first heating unit 600 is higher than the temperature of the second heating unit 700, regardless of the opposing distance. In other embodiments, the relationship between the opposing distance and the set temperature of the first heating unit 600 may be represented, for example, by a map defining the relationship between the opposing distance and the set temperature of the first heating unit 600.

[0045] In step S150, the control unit 500 stacks layers of the molding material according to the molding data acquired in step S110. More specifically, in step S150, the control unit 500 controls the ejection unit 200, the position change unit 400, and the first heating unit 600 and the second heating unit 700, as explained with reference to Figure 7, to build one layer of the three-dimensional object in the molding area. For example, in step S150, which is performed for the first time, the first layer of the three-dimensional object is stacked directly on the molding surface 311. In this embodiment, as described above, in step S140, which is performed prior to step S150, the set temperature of the first heating unit 600 is set based on the opposing distance and the set temperature of the second heating unit 700. Therefore, it can also be said that in step S150, the control unit 500 controls the first heating unit 600 based on the opposing distance and the set temperature of the second heating unit 700.

[0046] In step S160, the control unit 500 determines whether the fabrication of all layers of the three-dimensional object has been completed. If the control unit 500 determines in step S160 that the fabrication of all layers of the three-dimensional object has been completed, it terminates the three-dimensional fabrication process. Note that when the control unit 500 terminates the three-dimensional fabrication process, it does not have to immediately turn off the first heating unit 600 or the second heating unit 700, and may keep the first heating unit 600 or the second heating unit 700 on for a predetermined period of time. If the control unit 500 determines in step S160 that the fabrication of all layers of the three-dimensional object has not been completed, it returns to step S130. In this way, the control unit 500 fabricates a three-dimensional object by repeatedly stacking layers of fabrication material in the fabrication area.

[0047] As described above, the three-dimensional molding apparatus 100 in this embodiment is configured such that the relative position of the extrusion unit 200 and the stage 300 changes, and a first heating unit 600 is provided that covers the molding area when viewed along the Z direction at a position facing the molding surface 311, and heats the molding material stacked in the molding area. The control unit 500 controls the first heating unit 600 based on the opposing distance when molding a three-dimensional object. With this configuration, the first heating unit 600 can heat the entire three-dimensional object while preferentially heating the upper layers. Furthermore, since the first heating unit 600 is controlled based on the opposing distance, the temperature of the three-dimensional object can be appropriately controlled regardless of the progress of layering. As a result, deformation of the shape of the three-dimensional object can be suppressed, and the adhesion between layers can be improved.

[0048] Furthermore, in this embodiment, the control unit 500 sets the temperature of the first heating unit 600 to a first set temperature when the opposing distance is a first distance, and sets the temperature of the first heating unit 600 to a second set temperature which is higher than the first set temperature when the opposing distance is a second distance which is longer than the first set temperature. Therefore, the temperature of the three-dimensional object can be appropriately controlled regardless of the progress of layering with simple control.

[0049] Furthermore, in this embodiment, a second heating unit 700 is provided to heat the stage 300, and the control unit 500 controls the second heating unit 700 when fabricating a three-dimensional object. With this configuration, by controlling the second heating unit 700, the three-dimensional object can be heated from the stage 300 side in the layering direction, and the amount of heat supplied from the stage 300 to the three-dimensional object can be controlled. Therefore, the temperature of the three-dimensional object can be controlled more appropriately.

[0050] Furthermore, in this embodiment, when fabricating a three-dimensional object, the control unit 500 controls the first heating unit 600 not only based on the distance to the heating unit but also on the set temperature of the second heating unit 700. This allows the first heating unit 600 to be controlled while taking into account the effect of the heat supplied to the three-dimensional object from the second heating unit 700 via the stage 300, without the need to provide sensors to measure the temperature of the stage 300 or the layers. Therefore, the temperature of the three-dimensional object can be controlled more precisely with a simple configuration.

[0051] B. Second Embodiment: Figure 10 shows a schematic configuration of the three-dimensional molding apparatus 100b in the second embodiment. Unlike the first embodiment, the three-dimensional molding apparatus 100b in this embodiment is equipped with a first sensor 710 for measuring the temperature of the stage 300. In this embodiment, the control unit 500 controls the first heating unit 600 based on the opposing distance and the measurement value of the first sensor 710 when molding a three-dimensional object. In other words, in this embodiment, the control unit 500 does not control the first heating unit 600 based on the set temperature of the second heating unit 700. The configuration of the three-dimensional molding apparatus 100b in this embodiment is the same as in the first embodiment unless otherwise described.

[0052] In this embodiment, the first sensor 710 is configured as a thermistor and is installed on the stage 300. The temperature measurement of the stage 300 measured by the first sensor 710 is transmitted to the control unit 500. In other embodiments, the first sensor 710 may be configured as, for example, a thermocouple or a radiation thermometer.

[0053] Figure 11 is a flowchart of the three-dimensional molding process in the second embodiment. In Figure 11, the same reference numerals are used for the same steps as in Figure 9, which was described in the first embodiment.

[0054] In step S125, the control unit 500 acquires the measurement value of the first sensor 710. In step S140b, the control unit 500 determines the set temperature of the first heating unit 600 using a predetermined relationship between the opposing distance and the set temperature of the first heating unit 600, based on the opposing distance acquired in step S130 and the measurement value of the first sensor 710 acquired in step S130. In this embodiment, the relationship between the opposing distance and the set temperature of the first heating unit 600 is represented by a monotonically increasing function defined for each temperature of the stage 300. This function is defined, for example, as described in the first embodiment, to achieve the above-mentioned improvement in interlayer adhesion and suppression of deformation of the layer shape regardless of the number of existing layers.

[0055] In step S150, the control unit 500 stacks layers of the molding material in the same manner as in step S150 in Figure 9. In this embodiment, in step S140b, which is performed prior to step S150, the set temperature of the first heating unit 600 is set based on the opposing distance and the measurement value of the first sensor 710. Therefore, it can be said that in step S150, the control unit 500 controls the first heating unit 600 based on the opposing distance and the measurement value of the first sensor 710.

[0056] According to the three-dimensional molding apparatus 100b of this embodiment described above, a first sensor 710 is provided for measuring the temperature of the stage 300, and the control unit 500 controls the first heating unit 600 based on the opposing distance and the measurement value of the first sensor 710 when molding a three-dimensional object. This makes it possible to control the first heating unit 600 while taking into account the effect of the heat supplied from the stage 300 to the three-dimensional object based on the measurement value of the first sensor 710. As a result, the temperature of the three-dimensional object can be controlled more precisely.

[0057] C. Third Embodiment: Figure 12 shows a schematic configuration of the three-dimensional molding apparatus 100c in the third embodiment. Unlike the first embodiment, the three-dimensional molding apparatus 100c in this embodiment is equipped with a second sensor 720 for measuring the layer temperature. In this embodiment, the control unit 500 controls the first heating unit 600 when molding a three-dimensional object, based on the distance to the object, the set temperature of the second heating unit 700, and the measurement value of the second sensor 720. The configuration of the three-dimensional molding apparatus 100c in this embodiment is the same as in the first embodiment unless otherwise described.

[0058] In this embodiment, the second sensor 720 is positioned opposite the stage 300 and measures the temperature of the layers of material deposited in the build area on the build surface 311. The second sensor 720 is configured to change its relative position to the stage 300 together with the extrusion unit 200. In this embodiment, the second sensor 720 is a radiation thermometer and is fixed to the nozzle 61. When viewed along the Z direction, the second sensor 720 is positioned so as not to overlap with the nozzle opening 62, but to overlap with the through hole 206 provided in the support unit 205. The lower end of the second sensor 720 is located above the nozzle opening 62. The second sensor 720 is controlled by the control unit 500, and the measured temperature of the layers measured by the first sensor 710 is transmitted to the control unit 500. In other embodiments, the second sensor 720 may be a contact thermometer, for example, a thermistor or a thermocouple.

[0059] Figure 13 is a flowchart of the three-dimensional molding process in the third embodiment. In Figure 13, the same reference numerals as in Figure 9, which was described in the first embodiment, are used.

[0060] In step S127, the control unit 500 measures the temperature of the layer using the second sensor 720 and obtains the measured value. In this embodiment, in step S127, the control unit 500 measures the temperature of the top layer, which is the layer stacked on top of the other layer at the time step S127 is executed.

[0061] In step S140c, the control unit 500 determines the set temperature of the first heating unit 600 based on the opposing distance acquired in step S130 and the measurement value of the second sensor 720 acquired in step S130, using a predetermined relationship between the opposing distance and the set temperature of the first heating unit 600. In this embodiment, the relationship between the opposing distance and the set temperature of the first heating unit 600 is expressed by a monotonically increasing function defined for each set temperature of the second heating unit 700, similar to the first embodiment. In this embodiment, in step S140c, the control unit 500 determines the set temperature of the first heating unit 600 to be the temperature determined based on the opposing distance using the above function, plus the difference between the predicted temperature of the uppermost layer and the measurement value acquired in step S130. The predicted temperature of the uppermost layer is a temperature predicted based on, for example, the distance to the opposite side, the set temperature of the first heating unit 600, and the set temperature of the second heating unit 700, and is predicted using, for example, a function defined by experiment.

[0062] In step S160, the control unit 500 stacks layers of the molding material in the same manner as in step S160 in Figure 9. In this embodiment, in step S140b, which is performed prior to step S160, the set temperature of the first heating unit 600 is set based on the opposing distance, the set temperature of the second heating unit 700, and the measurement value of the second sensor 720. Therefore, it can also be said that in step S150, the control unit 500 controls the first heating unit 600 based on the opposing distance, the set temperature of the second heating unit 700, and the measurement value of the first sensor 710.

[0063] According to the three-dimensional molding apparatus 100c of this embodiment described above, a second sensor 720 is provided for measuring the temperature of the layers, and the control unit 500 controls the first heating unit 600 based on the opposing distance and the measurement value of the second sensor 720 when molding a three-dimensional object. This allows the first heating unit 600 to be controlled taking into account the actual layer temperature measured by the second sensor 720. Therefore, the temperature of the three-dimensional object can be controlled more precisely.

[0064] D. Fourth Embodiment: Figure 14 is a flowchart of the three-dimensional molding process in the fourth embodiment. In this embodiment, unlike the first embodiment, the control unit 500 not only controls the first heating unit 600 based on the opposing distance, but also controls the second heating unit 700 based on the opposing distance during the three-dimensional molding process. The configuration of the three-dimensional molding apparatus 100 in this embodiment is the same as in the first embodiment unless otherwise described.

[0065] Steps S210 and S220 are the same as steps S110 and S130 in Figure 9, respectively, so their explanation is omitted.

[0066] In step S230, the control unit 500 determines the set temperature of the second heating unit 700 based on the opposing distance acquired in step S220. In this embodiment, the control unit 500 performs a second control in the three-dimensional molding process, setting the set temperature of the second heating unit 700 to the third set temperature when the opposing distance is the third distance, and setting the set temperature of the second heating unit 700 to the fourth set temperature, which is higher than the third set temperature, when the opposing distance is the fourth distance, which is longer than the third distance. For example, in the examples of Figures 7 and 8 described above, the distance D1 in Figure 7 corresponds to the third distance, and the distance D2 in Figure 8 corresponds to the fourth distance. Also, the set temperature of the second heating unit 700 when the eighth layer L8 is being molded corresponds to the third set temperature, and the set temperature of the second heating unit 700 when the ninth layer L9 is being molded corresponds to the fourth set temperature.

[0067] Steps S240 and S250 are the same as steps S140 and S150 in Figure 9, respectively, so their explanation is omitted. In step S260, the control unit 500 determines whether the fabrication of all layers of the three-dimensional object has been completed, similar to step S160 in Figure 9. If the control unit 500 determines that the fabrication of all layers of the three-dimensional object has been completed, it terminates the three-dimensional fabrication process. If the control unit 500 determines that the fabrication of all layers of the three-dimensional object has not been completed, it returns to step S220.

[0068] According to the three-dimensional molding apparatus 100 of this embodiment described above, the control unit 500 controls the second heating unit 700 based on the opposing distance when molding a three-dimensional object. Therefore, compared to, for example, the case where the second heating unit 700 is controlled to a constant output regardless of the opposing distance, the temperature of the three-dimensional object can be controlled more appropriately.

[0069] Furthermore, in this embodiment, the control unit 500 sets the temperature of the second heating unit 700 to the third set temperature when the opposing distance is the third distance, and sets the temperature of the second heating unit 700 to the fourth set temperature, which is higher than the third set temperature, when the opposing distance is the fourth distance, which is longer than the third distance. As a result, the temperature of the three-dimensional object can be controlled more appropriately with simple control, regardless of the progress of layering.

[0070] In other embodiments, the control unit 500 does not need to perform the second control when controlling the second heating unit 700 based on the opposing distance. For example, the control unit 500 may set the temperature of the second heating unit 700 to a lower temperature when the opposing distance is the fourth distance than when the opposing distance is the third distance. This allows, for example, when combined with the first control, the second heating unit 700 to efficiently heat the top layer during the relatively early stages of lamination, i.e., when there are few existing layers, because the heat from the second heating unit 700 contributes more to heating the top layer than the heat from the first heating unit 600, and the first heating unit 600 to efficiently heat the top layer during the relatively later stages of lamination, i.e., when there are many existing layers, because the heat from the first heating unit 600 contributes more to heating the top layer. Alternatively, for example, the control unit 500 may control the set temperature of the second heating unit 700 to a constant value until the lamination of a predetermined layer is completed, and then lower the set temperature of the second heating unit 700 after the lamination of that layer is completed. In this case, the control unit 500 may, for example, turn off the second heating unit 700 after the lamination of a predetermined layer is completed.

[0071] E. Other embodiments: (E-1) In the above embodiment, the control unit 500 performs the first control in the three-dimensional molding process. However, the control unit 500 does not have to perform the first control in the three-dimensional molding process. For example, the control unit 500 may control the first heating unit 600 based on the opposing distance using a function that is not a monotonically increasing function that defines the relationship between the opposing distance and the set temperature of the first heating unit 600. Also, for example, when the control unit 500 performs the second control described in the fourth embodiment, when the opposing distance is the second distance, the set temperature of the first heating unit 600 may be set to a lower temperature than the set temperature of the first heating unit 600 when the opposing distance is the first distance. Also, for example, the control unit 500 may control the set temperature of the first heating unit 600 to be constant until the stacking of a predetermined layer is completed, and then raise the set temperature of the first heating unit 600 after the stacking of that layer is completed.

[0072] (E-2) In the above embodiment, a second heating unit 700 is provided. However, the second heating unit 700 may not be provided. Even in this case, the control unit 500 may control the first heating unit 600 based on the measurement value of the first sensor 710, as in the second embodiment. This allows the first heating unit 600 to be controlled in consideration of the temperature change of the stage 300 due to the heat of the first heating unit 600, thereby enabling more precise control of the temperature of the three-dimensional object. Similarly, even if the second heating unit 700 is not provided, the control unit 500 may control the first heating unit 600 based on the measurement value of the second sensor 720, as in the third embodiment.

[0073] (E-3) In the above embodiment, the opposing distance may be calculated based on a detected value obtained by, for example, the stage 300 or a non-contact rangefinder equipped with a laser emitter and a laser receiver, or a contact rangefinder positioned opposite the stage 300. Alternatively, the opposing distance may be expressed by, for example, the number of existing layers or the value of n for the nth layer that is stacked. In this case, a larger number of existing layers or a larger value of n means a larger opposing distance.

[0074] (E-4) In the above embodiment, the plasticizing unit 30 comprises a screw 40 which is a flat screw and a barrel 50. However, the plasticizing unit 30 does not necessarily have to be a flat screw and a barrel 50. For example, the plasticizing unit 30 may be equipped with an inline screw, and the material may be plasticized by rotating the inline screw to produce the molding material.

[0075] (E-5) In the above embodiment, the three-dimensional molding apparatus 100 may be equipped with a plurality of nozzles 61, for example, it may be equipped with one or more discharge units 200 having a plurality of nozzles 61, or it may be equipped with a plurality of discharge units 200 having one nozzle 61.

[0076] (E-6) In the above embodiment, the discharge unit 200 is configured as a head that discharges material formed in pellet shape. In contrast, the discharge unit 200 may be configured as a head that plasticizes and discharges, for example, filament-shaped material.

[0077] (E-7) In the above embodiment, a resin material formed into pellets is used as the raw material supplied to the material storage section 20. In contrast, the three-dimensional molding apparatus 100 can mold three-dimensional objects using various materials as the main material, such as thermoplastic materials, metal materials, and ceramic materials. Here, "main material" means the central material that forms the shape of the three-dimensional object, and means a material that accounts for 50% by weight or more of the three-dimensional object. The molding materials mentioned above include those main materials that have been melted individually, and those in which some components contained together with the main material have been melted into a paste.

[0078] When a thermoplastic material is used as the main material, the molding material is generated in the plasticizing section 30 by the plasticization of the material. "Plasticization" means that heat is applied to the thermoplastic material and it melts.

[0079] Examples of thermoplastic materials that can be used include the following thermoplastic resin materials. <Examples of thermoplastic resin materials> General-purpose engineering plastics such as polypropylene resin (PP), polyethylene resin (PE), polyacetal resin (POM), polyvinyl chloride resin (PVC), polyamide resin (PA), acrylonitrile butadiene styrene resin (ABS), polylactic acid resin (PLA), polyphenylene sulfide resin (PPS), polyether ether ketone (PEEK), polycarbonate (PC), modified polyphenylene ether, polybutylene terephthalate, polyethylene terephthalate, and other engineering plastics, as well as polysulfone, polyethersulfone, polyphenylene sulfide, polyarylate, polyimide, polyamide-imide, polyether-imide, and polyether ether ketone.

[0080] The thermoplastic material may contain pigments, metals, ceramics, or other additives such as waxes, flame retardants, antioxidants, and heat stabilizers. In the plasticizing section 30, the thermoplastic material is plasticized and converted into a molten state by the rotation of the screw 40 and heating by the plasticizing heater 58. The molding material produced by the melting of the thermoplastic material is extruded from the nozzle 61 and then hardens as the temperature decreases.

[0081] It is desirable that thermoplastic materials be heated above their glass transition temperature and completely molten before being injected from the nozzle 61. For example, ABS resin has a glass transition temperature of approximately 120°C, and it is desirable that the temperature is approximately 200°C when it is ejected from the nozzle 61.

[0082] In the three-dimensional molding apparatus 100, instead of the thermoplastic material described above, for example, the following metal materials may be used as the main material. In this case, it is desirable that the powder material, which is made by pulverizing the following metal materials, is mixed with components that melt during the production of the molding material, and then introduced into the plasticizing section 30 as raw material. <Examples of metallic materials> A single metal such as magnesium (Mg), iron (Fe), cobalt (Co), or chromium (Cr), aluminum (Al), titanium (Ti), copper (Cu), or nickel (Ni), or an alloy containing one or more of these metals. <Example of the aforementioned alloy> Maraging steel, stainless steel, cobalt-chromium-molybdenum, titanium alloy, nickel alloy, aluminum alloy, cobalt alloy, cobalt-chromium alloy.

[0083] In the three-dimensional molding apparatus 100, ceramic materials can be used as the main material instead of the metal materials mentioned above. Examples of ceramic materials that can be used include oxide ceramics such as silicon dioxide, titanium dioxide, aluminum oxide, and zirconium oxide, as well as non-oxide ceramics such as aluminum nitride. When using metal or ceramic materials as described above as the main material, the molding material placed on the stage 300 may be hardened by sintering using laser irradiation or hot air.

[0084] The metal or ceramic powder materials introduced as raw materials into the material containment section 20 may be mixed materials containing multiple types of single metal powders, alloy powders, or ceramic powders. Furthermore, the metal or ceramic powder materials may be coated with a thermoplastic resin, such as those exemplified above, or other thermoplastic resins. In this case, the thermoplastic resin may melt in the plasticizing section 30 to achieve fluidity.

[0085] The metal and ceramic powder materials introduced as raw materials into the material containment section 20 may also have solvents added to them, such as those listed below. One or more solvents selected from the following can be used in combination. <Examples of solvents> Water; (poly)alkylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, and propylene glycol monoethyl ether; acetic acid esters such as ethyl acetate, n-propyl acetate, iso-propyl acetate, n-butyl acetate, and iso-butyl acetate; aromatic hydrocarbons such as benzene, toluene, and xylene; ketones such as methyl ethyl ketone, acetone, methyl isobutyl ketone, ethyl-n-butyl ketone, diisopropyl ketone, and acetylacetone; alcohols such as ethanol, propanol, and butanol; tetraalkylammonium acetates; sulfoxide solvents such as dimethyl sulfoxide and diethyl sulfoxide; pyridine solvents such as pyridine, γ-picoline, and 2,6-lutidine; tetraalkylammonium acetate (e.g., tetrabutylammonium acetate); ionic liquids such as butylcarbitol acetate, etc.

[0086] In addition, the following types of binders can be added to the metal and ceramic powder materials that are introduced as raw materials into the material storage section 20. <Example of a binder> Acrylic resin, epoxy resin, silicone resin, cellulose resin or other synthetic resin, or PLA (polylactic acid), PA (polyamide), PPS (polyphenylene sulfide), PEEK (polyether ether ketone) or other thermoplastic resin.

[0087] F. Other forms: This disclosure is not limited to the embodiments described above, and can be implemented in various forms without departing from its spirit. For example, this disclosure can also be implemented in the following forms. The technical features in the embodiments described below that correspond to the technical features in each of the forms described below can be replaced or combined as appropriate in order to solve some or all of the problems of this disclosure, or to achieve some or all of the effects of this disclosure. Furthermore, if such technical features are not described as essential in this specification, they can be deleted as appropriate.

[0088] (1) According to one embodiment of the present disclosure, a three-dimensional molding apparatus is provided. The three-dimensional molding apparatus comprises a stage having a molding surface on which a molding material is stacked; an ejection unit for ejecting the molding material toward a molding region on the molding surface; a position change unit for changing the relative position between the ejection unit and the stage; a first heating unit configured to change its relative position with the stage together with the ejection unit, and at a position facing the molding surface, covering the molding region when viewed along the stacking direction of the molding material, and heating the molding material stacked in the molding region; and a control unit that stacks layers of the molding material in the molding region to form a three-dimensional object by controlling the ejection unit, the first heating unit, and the position change unit. When forming the three-dimensional object, the control unit controls the first heating unit based on a facing distance, which represents the distance between the stage and the first heating unit in the stacking direction. With this configuration, the first heating section can heat the entire three-dimensional object while preferentially heating the upper layers. Furthermore, since the first heating section is controlled based on the opposing distance, the temperature of the three-dimensional object can be appropriately controlled regardless of the progress of layering. As a result, deformation of the three-dimensional object's shape can be suppressed, and the adhesion between layers can be improved.

[0089] (2) In the above configuration, the control unit may set the temperature of the first heating unit to the first set temperature when the opposing distance is the first distance, and set the temperature of the first heating unit to the second set temperature which is higher than the first set temperature when the opposing distance is the second distance which is longer than the first distance. With this configuration, the temperature of the three-dimensional object can be appropriately controlled by simple control, regardless of the progress of the layering.

[0090] (3) In the above embodiment, the stage is provided with a second heating unit, and the control unit may control the second heating unit when fabricating the three-dimensional object. With this embodiment, by controlling the second heating unit, the three-dimensional object can be heated from the stage side in the stacking direction, and the amount of heat supplied from the stage to the three-dimensional object can be controlled. As a result, the temperature of the three-dimensional object can be controlled more appropriately.

[0091] (4) In the above embodiment, the control unit may control the second heating unit based on the opposing distance when fabricating the three-dimensional object. With this embodiment, the temperature of the three-dimensional object can be controlled more appropriately compared to when the second heating unit is controlled to a constant output or when the second heating unit is controlled to a constant output regardless of the opposing distance.

[0092] (5) In the above configuration, the control unit may set the temperature of the second heating unit to the third set temperature when the opposing distance is the third distance, and set the temperature of the second heating unit to the fourth set temperature which is higher than the third set temperature when the opposing distance is the fourth distance which is longer than the third distance. With this configuration, the temperature of the three-dimensional object can be controlled more appropriately by simple control, regardless of the progress of layering.

[0093] (6) In the above configuration, the control unit may control the first heating unit based on the opposing distance and the set temperature of the second heating unit when fabricating the three-dimensional object. With this configuration, the first heating unit can be controlled by taking into account the effect of the heat supplied to the three-dimensional object from the second heating unit via the stage, without the need to provide sensors to measure the temperature of the stage or layers. As a result, the temperature of the three-dimensional object can be controlled more precisely with a simple configuration.

[0094] (7) In the above embodiment, a first sensor for measuring the temperature of the stage may be provided, and the control unit may control the first heating unit based on the opposing distance and the measurement value of the first sensor when fabricating the three-dimensional object. With this embodiment, the first heating unit can be controlled based on the measurement value of the first sensor, taking into account the effect of the heat supplied from the stage to the three-dimensional object. As a result, the temperature of the three-dimensional object can be controlled more precisely.

[0095] (8) In the above embodiment, a second sensor for measuring the temperature of the layer may be provided, and the control unit may control the first heating unit based on the opposing distance and the measurement value of the second sensor when fabricating the three-dimensional object. With this embodiment, the first heating unit can be controlled taking into account the actual layer temperature measured by the second sensor. Therefore, the temperature of the three-dimensional object can be controlled more precisely. [Explanation of symbols]

[0096] 20...Material storage section, 22...Supply path, 30...Plasticizing section, 31...Screw case, 32...Drive motor, 40...Screw, 41...Screw top surface, 42...Screw bottom surface, 44...Material inlet, 45...Groove section, 46...Protruding section, 47...Center section, 50...Barrel, 52...Barrel top surface, 54...Guide groove, 56...Communication hole, 58...Plasticizing heater, 61...Nozzle, 62...Nozzle opening, 6 3…Tip surface, 65…Nozzle flow path, 100, 100b, 100c…Three-dimensional molding device, 200…Discharge section, 205…Support section, 206…Through hole, 300…Stage, 311…Mounting surface, 400…Position change section, 410…Head movement mechanism section, 420…Stage movement mechanism section, 500…Control section, 600…First heating section, 700…Second heating section, 710…First sensor, 720…Second sensor

Claims

1. A stage having a build surface on which the build material is layered, A dispensing unit that dispenses the molding material toward the molding area on the molding surface, A position changing unit that changes the relative position between the discharge unit and the stage, A first heating unit is configured to change its relative position to the stage together with the discharge unit, and at a position facing the molding surface, it covers the molding area when viewed along the layering direction of the molding material, and heats the molding material layered in the molding area. The system comprises a control unit that controls the discharge unit, the first heating unit, and the position changing unit to build a three-dimensional object by stacking layers of the molding material in the molding area, The control unit, when fabricating the three-dimensional object, controls the stage in the stacking direction. Based on the opposing distance, which represents the distance between the first heating unit and the first heating unit, the first heating unit is controlled, and when the opposing distance is the first distance, the set temperature of the first heating unit is set to the first set temperature, and when the opposing distance is a second distance which is longer than the first distance, the set temperature of the first heating unit is set to a second set temperature which is higher than the first set temperature. Three-dimensional printing equipment.

2. A three-dimensional molding apparatus according to claim 1, The stage is further equipped with a second heating section for heating the aforementioned stage. The control unit controls the second heating unit when creating the three-dimensional object, in a three-dimensional molding apparatus.

3. A three-dimensional molding apparatus according to claim 2, The control unit controls the second heating unit based on the opposing distance when creating the three-dimensional object, in a three-dimensional molding apparatus.

4. A three-dimensional molding apparatus according to claim 3, A three-dimensional molding apparatus wherein the control unit sets the set temperature of the second heating unit to a third set temperature when the opposing distance is a third distance, and sets the set temperature of the second heating unit to a fourth set temperature which is higher than the third set temperature when the opposing distance is a fourth distance which is longer than the third distance.

5. A three-dimensional molding apparatus according to any one of claims 2 to 4, The control unit controls the first heating unit based on the opposing distance and the set temperature of the second heating unit when creating the three-dimensional object, in a three-dimensional molding apparatus.

6. A three-dimensional molding apparatus according to any one of claims 1 to 5, The system includes a first sensor for measuring the temperature of the stage, The control unit controls the first heating unit based on the opposing distance and the measurement value of the first sensor when creating the three-dimensional object, in a three-dimensional molding apparatus.

7. A three-dimensional molding apparatus according to any one of claims 1 to 5, The system includes a second sensor for measuring the temperature of the aforementioned layer, The control unit controls the first heating unit based on the opposing distance and the measurement value of the second sensor when creating the three-dimensional object, in a three-dimensional molding apparatus.

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