Program for generating data for stereo-lithographic modeling, and method for manufacturing stereo-lithographic objects

Abstract

To provide technology to control the wobble and fall of molding objects.SOLUTION: The program for generating data for stereo-lithography determines a path to form a through channel TH inside the support SP that supports the three-dimensional object OB to be modeled, where the entrance HI faces upward and the exit HO is on the surface facing the three-dimensional object OB, and for the layer LT including the upper end of the through channel TH, adds an instruction to pour the material into the through channel TH after molding the layer LT. When modeling using the data generated in this way, the material poured in after modeling layer LT fills the through channel TH, protrudes from the exit HO, and adheres to the three-dimensional object OB. Since the layer to which the material adheres is formed at approximately the same time as the layer forming the lower part of the through channel TH, the adhered material is sufficiently cooled at the time the material adheres and is not easily integrated with the three-dimensional object OB even if it solidifies. Therefore, the wobble and fall of the three-dimensional object OB can be suppressed by the support SP during modeling, and the support SP can be easily removed after modeling.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to a program for generating three-dimensional modeling data used in modeling by a three-dimensional modeling device such as a 3D printer, and a method for manufacturing a three-dimensional object. [Background technology]

[0002] As a method for forming a three-dimensional object, fused filament fabrication (hereinafter referred to as "FFF method") is known, which forms an object by stacking layers of material melted by heat (see, for example, Patent Document 1). When forming an object with a high center of gravity or an object that is long in the stacking direction, such as a pencil, chimney, or tower, there is a risk that the object will wobble or fall over during the forming process.

[0003] As a countermeasure to such problems, a well-known method has been to form multiple objects (hereinafter referred to as "sacrificial objects") whose sole purpose is to support the object to be printed, sandwiching the object between them with a gap between them (each layer of both is formed one after the other by forming a layer at the same height of the object to be printed and the sacrificial objects, and then forming the next layer of the object to be printed and the sacrificial objects), and in some layers, attaching the ends of the sacrificial objects to the sides of the object to be printed, thereby supporting the object to be printed with the sacrificial objects during printing, and then removing the sacrificial objects from the object to be printed after printing. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2000-500709 Summary of the Invention [Problem to be solved by the invention]

[0005] In the above-mentioned method, immediately after forming a layer of the object to be molded, a layer of a sacrificial object is formed whose end portion is attached to the side surface of the layer, and since the temperature difference between the two is small, the end portion of the sacrificial object is likely to be integrated with the side surface of the object to be molded. As a result, it becomes difficult to remove the sacrificial object after molding, and if an attempt is made to remove it forcibly, it may affect the finish of the object to be molded, and in the worst case, the object to be molded may be damaged, so removing the sacrificial object takes time and effort. On the other hand, if the distance between the two is made larger to avoid integration, the suppression of wobbling and tipping becomes weak. Therefore, a countermeasure that can suppress wobbling and tipping of the object to be molded without affecting the finish of the object to be molded is required.

[0006] Therefore, an object of the present invention is to provide a technique for preventing an object to be shaped from wobbling or falling over. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention provides the following 3D modeling data generation program and 3D object manufacturing method. Note that the following words in parentheses are merely examples, and the present invention is not limited thereto.

[0008] In other words, the three-dimensional modeling data generation program of the present invention is a three-dimensional modeling data generation program that generates data to be used by an apparatus that forms a three-dimensional object by stacking model materials, and causes a computer to execute an instruction generation step of forming the shape of the three-dimensional object to be formed and the shape of a support that supports the three-dimensional object having an internal through passage with an entrance facing upward and an exit facing the three-dimensional object at a lower position than the entrance along a determined path for each layer that is divided into a plurality of layers, and generating data that instructs a computer to pour a predetermined amount of model material into the through passage after forming the layer that forms the entrance.

[0009] When modeling is performed according to the data generated by the three-dimensional modeling data generation program of this embodiment, after the layer forming the entrance of the through passage (the layer including the upper end of the through passage) is modeled, a predetermined amount of model material is poured into the through passage, so that the model material mostly fills the through passage and then overflows from the exit and adheres to part of the three-dimensional object, where it cools and solidifies over time. Here, the layer to which the model material is attached is modeled at roughly the same time as the layer forming the exit of the through passage, and therefore is cooled when the model material is poured into the through passage, so even if the attached model material solidifies, it is difficult to integrate with these layers forming the three-dimensional object.

[0010] Therefore, according to this embodiment of the data generation program for three-dimensional modeling, during modeling, the three-dimensional object can be supported on a support body connected via the model material protruding from the outlet, thereby preventing the three-dimensional object from wobbling or tipping over, and after modeling, the support body can be easily removed from the three-dimensional object.

[0011] Preferably, in the data generation program for three-dimensional modeling of the above aspect, the following steps are executed prior to the command generation step: a support shape determination step for determining the shape and position of the support taking into account the shape of the three-dimensional object; a temperature prediction step for calculating the time required to model each layer obtained by dividing the shape of the three-dimensional object and the shape of the support into a plurality of layers and predicting the temperature drop of each layer during modeling; and a through passage shape determination step for determining the shape of the through passage based on the prediction result in the temperature prediction step so that the temperature difference between the layer forming the entrance and the layer forming the exit at the time the model material is poured into the through passage is equal to or greater than a predetermined threshold value.

[0012] According to this type of data generation program for three-dimensional modeling, the shape of the through passage is determined based on the predicted temperature drop of each layer during modeling, so that the temperature difference between the layer forming the entrance and the layer forming the exit at the time the model material is poured in is equal to or greater than a predetermined threshold value.Therefore, at the time of modeling, the layer of the three-dimensional object at the same height as the layer forming the exit of the through passage is allowed to cool sufficiently before the model material is poured in.This reliably prevents the model material poured into the through passage from becoming integrated with the three-dimensional object to which it adheres, and makes it possible to easily remove the support after modeling.

[0013] More preferably, in the three-dimensional modeling data generating program according to the above aspect, in the through path shape determining step, the predetermined amount is determined taking into consideration the shape of the through path.

[0014] If there is not enough model material poured into the through passage, the model material that protrudes from the outlet cannot be sufficiently attached to the solid object, and there is a risk that the support body will not support the solid object properly, while if there is too much model material, an excessive amount of model material will adhere to the solid object, causing the support body to apply unnecessary force to the solid object, which may affect subsequent modeling. In contrast, according to the three-dimensional modeling data generation program of this aspect, the amount of model material poured into the through passage is determined based on the shape of the through passage, so that an appropriate amount of model material, neither too much nor too little, can be poured into the through passage, and as a result, the support body can stably support the solid object.

[0015] More preferably, in the three-dimensional modeling data generating program according to any one of the above aspects, in the through path shape determining step, a position of the through path in the support is determined in consideration of factors that affect stable standing of the three-dimensional object.

[0016] According to this embodiment of the data generation program for three-dimensional modeling, the position of the through passage is determined taking into account factors that affect the stable standing of the three-dimensional object (for example, the position of the center of gravity of the three-dimensional object, etc.). Therefore, by supporting the three-dimensional object on a support body having such a through passage, the standing of the three-dimensional object can be made more stable, and wobbling and tipping over can be more effectively prevented. Effect of the Invention

[0017] According to the present invention, it is possible to suppress wobbling and tipping over of the object to be shaped. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a diagram illustrating an example of an environment in which a three-dimensional modeling apparatus operates. [Diagram 2]FIG. 2 is a diagram illustrating an example of an environment in which a three-dimensional modeling data generation program operates. [Diagram 3] 11 is a schematic diagram showing a method of managing positions in a three-dimensional modeling apparatus. FIG. [Figure 4] FIG. 13 is a diagram showing the state immediately after a tensile test piece is modeled using data generated by a 3D modeling data generation program. [Diagram 5] FIG. 2 is a functional block diagram showing an example of the configuration of a three-dimensional modeling data generation program. [Figure 6] 11 is a flowchart showing an example of a procedure for a three-dimensional modeling data generation process. [Figure 7] 11 is a flowchart showing an example of a procedure for a layer-modeling data generation process. [Figure 8] 10A and 10B are diagrams illustrating through passages formed inside a support body. [Figure 9] 13A and 13B are diagrams showing modified examples of the shape of the through passage. [Figure 10] FIG. 13 is a diagram illustrating how to use the through passage when the upper end portion of the through passage is made into a countersunk shape. [Figure 11] FIG. 13 is a diagram showing an example in which a through passage is formed inside a general support region. [Figure 12] 10A to 10C are diagrams showing various examples of the positions and numbers of supports to be installed on a shaped object. [Figure 13] 13A to 13C are diagrams showing modified examples of the positions of through passages formed in the support body. [Figure 14] 13A to 13C are diagrams illustrating further examples of use of the support body. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the following embodiments are preferred examples, and the present invention is not limited to these examples.

[0020] [Operating environment of 3D modeling device] FIG. 1 is a diagram showing an example of an environment in which a 3D modeling apparatus 40 operates, which models a 3D object using 3D modeling data generated by a 3D modeling data generation program according to an embodiment.

[0021] The terminal 10 is a computer that uses the 3D modeling device 40, and has a 3D modeling data generation program implemented therein. The 3D modeling device 40 is connected to the printer server 30 via a USB port, a serial port, or the like, and is capable of transmitting and receiving data to and from the printer server 30. The printer server 30 is a computer that manages / controls print jobs for the 3D modeling device 40, similar to a typical printer server, and is connected to a wired or wireless network 20. When modeling a three-dimensional object, the terminal 10 transmits 3D modeling data used for modeling to the printer server 30 via the network 20 together with a print request (modeling request).

[0022] When the printer server 30 receives a print request from the terminal 10, it inserts the request into a queue as one print job and receives the 3D modeling data. When the 3D modeling device 40 starts a print job, the printer server 30 transmits the 3D modeling data to the 3D modeling device 40 in small amounts. At this time, the amount of data transmitted to the 3D modeling device 40 is appropriately adjusted by a control program implemented inside the printer server 30. When all the 3D modeling data for one print job is transmitted to the 3D modeling device 40 and the 3D modeling device 40 finishes the operation based on this data, the 3D modeling device 40 finishes printing (modeling).

[0023] In addition, in Figure 1, a configuration has been described as an example in which the terminal 10 uses the 3D modeling device 40 via the printer server 30, but it is also possible to use the 3D modeling device 40 by directly connecting it to the terminal 10 without using the printer server 30, or to use the 3D modeling device 40 alone (disconnected from the terminal 10) by inserting a storage medium such as a USB memory or an SD card on which data for 3D modeling is stored.

[0024] [Operating environment for the 3D modeling data generation program] 2 is a diagram showing an example of an environment in which the 3D modeling data generation program according to an embodiment operates. The 3D modeling data generation program is implemented in the terminal 10 as described above.

[0025] The terminal 10 is a computer equipped with the functions of a general computer, and includes, as hardware, a CPU 11, a RAM 12, a network interface (I / F) 13, and a HDD 14, as well as an input device 15 such as a mouse, a keyboard, or a touch panel, and a display device 16 such as a liquid crystal display. As software, the terminal 10 is installed with 3D modeling software 17 that outputs polygon data (e.g., data in STL format) consisting of a collection of polygons that represent a three-dimensional shape, a three-dimensional modeling data generation software 100 that generates three-dimensional modeling data based on the polygon data output from the 3D modeling software 17, and a printer driver 18 that is necessary for the terminal 10 to use the three-dimensional modeling device 40. Here, the three-dimensional modeling data generation software 100 is a so-called "slicer (slicing software)" and is implemented by a three-dimensional modeling data generation program of one embodiment.

[0026] When the polygon data output by the 3D modeling software 17 is input to the 3D modeling data generation software 100, the 3D modeling data generation software 100 repeatedly slices (horizontally cuts) the 3D shape formed by the polygon data into flat plates in the stacking direction (height direction), determines paths for forming each layer resulting from this, and generates command data for discharging material along the determined paths one after another. Then, when the command data for forming all layers constituting the 3D shape are generated, the 3D modeling data generation software 100 outputs a collection of these command data as 3D modeling data (for example, data in G-Code format). When modeling a 3D shape, the terminal 10 transmits a print request and 3D modeling data to the printer server 30 via the printer driver 18 and the network interface 13.

[0027] 2, the configuration has been described with the 3D modeling software 17 installed in the terminal 10 that uses the 3D modeling device 40, but the 3D modeling software 17 does not necessarily have to be installed in the terminal 10, and it is sufficient if the terminal 10 is configured to be able to input polygon data to the 3D modeling data generation software 100. The terminal 10 may also be equipped with other software, external devices, etc., as necessary.

[0028] As described above, the substance of the 3D modeling data generation software 100 is a 3D modeling data generation program of one embodiment, so in the following description, the 3D modeling data generation software 100 will be referred to as the 3D modeling data generation program 100.

[0029] FIG. 3 is a schematic diagram showing a method for managing positions in the three-dimensional object forming apparatus 40. As shown in FIG.

[0030] The three-dimensional modeling device 40 has a configuration required for forming a three-dimensional object in the internal space of a housing 41. First, a flat modeling table 42 is provided at the bottom of the internal space. The material MM is discharged onto the modeling table 42, and multiple layers constituting the three-dimensional object are formed in order from the bottom up, and the upper layers are successively stacked on the lower layers to form a three-dimensional object OB.

[0031] The material MM is discharged downward from the discharge nozzle 44. Before being supplied to the discharge nozzle 44, the material MM is in the form of a solid filament in the form of a string, but is heated to a high temperature by a heater provided inside the discharge nozzle 44, melted, and discharged in a fluidized state before being discharged from the discharge nozzle 44. The discharge nozzle 44 is supported by a support arm 43, and is configured to be movable within the internal space as the support arm 43 moves in the horizontal direction (X-axis and Y-axis directions in the figure) and the height direction (Z-axis direction in the figure). Note that the support arm 43 may be configured to be movable only in the horizontal direction, and the modeling table 42 may be configured to be movable in the height direction. Alternatively, the modeling table 42 may be configured to be movable in the horizontal direction as well, and the discharge position of the material MM may be changed by moving the modeling table 42 and the support arm 43.

[0032] The position in the internal space is managed by three-dimensional coordinates. The three-dimensional modeling data used in modeling lists a large number of commands required for drawing lines that discharge the material MM to form (fill in) each layer, specifically, commands that specify the coordinates of the destination and moving speed of the discharge nozzle 44, the discharge amount of the material MM, the discharge pressure, the discharge temperature, etc. In addition, in FIG. 3, the modeling table 42 is shown with lattice-like lines to make it easier to visualize the coordinates, but such lines are not drawn on the actual modeling table 42. In addition, the three-dimensional modeling device 40 may be of a type in which the discharge nozzle 44 is supported by three movable parts of a pair of axes arranged in a delta shape (a so-called "delta type 3D printer").

[0033] [Shape of the three-dimensional object] 4 is a diagram showing a state immediately after a tensile test piece is modeled using data generated by the 3D modeling data generation program 100. Note that in order to facilitate understanding of the invention, the objects shown in the drawings are exaggerated in size in the subsequent drawings, and the shapes and sizes of the objects, the sizes of the gaps between the objects, the size ratios between the objects and the gaps, and the like do not necessarily correspond to the actual ones.

[0034] FIG. 4A is a perspective view showing the state of a three-dimensional object OB immediately after it is formed. The three-dimensional object OB shown in the figure is a dumbbell-shaped tensile test piece defined in the ASTM D638 standard, and is formed by stacking materials in the tensile direction of the test piece. In addition, two supports SP are formed at positions slightly away from the three-dimensional object OB so as to sandwich the three-dimensional object OB from both sides in the thickness direction. In the figure, a part of the three-dimensional object OB is hidden by the supports SP, so that the overall shape cannot be confirmed, but the three-dimensional object OB has a shape that is symmetrical from top to bottom, and the wide parts at the upper and lower ends correspond to the parts that are gripped in the tensile test.

[0035] FIG. 4B: Plan view showing the state of the three-dimensional object OB immediately after it has been molded. The three-dimensional object OB and the supports SP are molded together, and inside each support SP, one or more through passages TH are formed, with the entrance facing upward and the exit facing sideways. The exit of the through passage TH is provided on the surface facing the three-dimensional object OB, and material MM is poured into the through passage TH during molding of the layer forming the entrance of the through passage TH, i.e., the layer including the upper end of the through passage TH (hereinafter, sometimes referred to as the "upstream layer of the through passage"). This causes the material MM to overflow from the exit and adhere to the side of the three-dimensional object OB. The three-dimensional object OB is supported from the side by the supports SP connected via this part, which increases the stability of the upright object and prevents it from wobbling or falling over.

[0036] Here, since the layer with the entrance of the through passage TH is modeled after the layer with the exit, when the material MM is poured into the through passage TH, a temperature difference occurs between the layer with the entrance and the layer with the exit, so the material MM poured from the through passage is unlikely to be integrated with the three-dimensional object OB. Therefore, after modeling, the support OB can be easily removed from the three-dimensional object. When the two supports SP are removed from the three-dimensional object OB in the illustrated state, the three-dimensional object OB is completed.

[0037] In this way, by forming a support body SP having the above-mentioned through passage TH together with the three-dimensional object OB (together, simultaneously), it is possible to achieve both reliable support of the three-dimensional object OB by the support body SP during formation and easy removal of the support body SP after formation.

[0038] Next, a configuration and main processes of the 3D modeling data generation program 100 that generates data for such modeling will be described.

[0039] [Configuration of the program for generating data for 3D modeling] 5 is a functional block diagram showing an example of the configuration of the 3D modeling data generation program 100. The 3D modeling data generation program 100 includes, for example, a various setting unit 110, a 3D shape input unit 120, a 3D shape analysis unit 130, a support shape determination unit 140, a shape cutting unit 150, a temperature prediction unit 160, a cross-sectional shape analysis unit 170, a path determination unit 180, and a generated data output unit 190.

[0040] The various setting unit 110 presets various thresholds and parameter values ​​(for example, the range of width (thickness, amount of discharge) of the material to be discharged, various temperatures (temperature inside the chamber, temperature of the modeling table 42, internal temperature of the discharge nozzle 44), etc.) required for the 3D modeling data generation program to function, the pattern of the shape to be drawn, etc. In addition, the various setting unit 110 provides a setting screen for the user, and stores the contents set by the user via the setting screen in the internal memory area (HDD 14) of the terminal 10.

[0041] The three-dimensional shape input unit 120 inputs polygon data that forms a three-dimensional shape. More specifically, the three-dimensional shape input unit 120 reads polygon data output by 3D modeling software such as 3D-CAD. The polygon data is stored in a storage area accessible from the terminal 10 (for example, the HDD 14 or a separately connected external storage medium, etc.).

[0042] The three-dimensional shape analysis unit 130 analyzes the shape of a three-dimensional object formed by the polygon data input to the three-dimensional shape input unit 120 .

[0043] The support shape determination unit 140 determines the shape and position of the support to be formed in order to support the three-dimensional object to be formed, and the shape, position, number, etc. of the through passages to be formed inside the support, based on the analysis result by the three-dimensional shape analysis unit 130. In addition, the support shape determination unit 140 receives feedback from the temperature prediction unit 160, which will be described later, and adjusts the shape, etc. of the through passages as necessary.

[0044] The shape cutting unit 150 cuts the overall three-dimensional shape, which is a combination of the shape of the three-dimensional object formed by the polygon data input to the three-dimensional shape input unit 120 and the shape of the support body determined by the support shape determination unit 140, into multiple flat plate shapes (horizontally at multiple positions of different heights) and divides it into multiple layers stacked in the stacking direction (height direction).

[0045] The temperature prediction unit 160 estimates the modeling time of each layer including the through passage (forming the through passage) from each shape of the multiple layers divided by the shape cutting unit 150, and predicts the temperature drop of each layer over time. More specifically, the temperature prediction unit 160 predicts the temperature difference between the layer forming the exit of the through passage (hereinafter referred to as the "downstreammost layer of the through passage") during modeling of the upstreammost layer of the through passage based on the estimated modeling time and various temperatures related to modeling, determines whether the predicted temperature difference is sufficient, and feeds back the result to the support shape determination unit 140.

[0046] The cross-sectional shape analysis unit 170 analyzes the shape of each cross section cut by the shape cutting unit 150, in other words, the shape of each layer of the divided three-dimensional object and support.

[0047] Based on the results of the analysis by the cross-sectional shape analysis unit 170, the path determination unit 180 determines detailed matters related to the path, such as the path for discharging the material to form each layer, the order, direction, and speed in following the path, the material discharging width and amount, etc. (hereinafter, these are collectively referred to as "path"), and generates command data according to the determined path. In addition, the path determination unit 180 generates command data to pour the material into the through passage after forming the uppermost layer of the through passage.

[0048] The generated data output unit 190 outputs a collection of command data generated by the path determination unit 180, that is, data for three-dimensional printing.

[0049] In the above example, the temperature prediction unit 160 estimates the modeling time of each layer including the through passage, but instead, the path determination unit 180 may more accurately calculate the modeling time of each layer, and based on this, the temperature prediction unit 160 may predict the temperature difference between the most upstream layer of the through passage and the most downstream layer of the through passage when modeling the most upstream layer of the through passage. In such a configuration, when the support shape determination unit 140 adjusts the shape of the through passage according to the predicted temperature difference, the path determination unit 180 must re-determine (correct) the path of the layer including the through passage, but it is possible to more accurately predict the temperature difference between the most upstream layer and the most downstream layer of the through passage when modeling the most upstream layer of the through passage, and more reliably prevent the material poured into the through passage from being integrated with the three-dimensional object.

[0050] [3D modeling data generation process] 6 is a flowchart showing an example of the procedure of the 3D modeling data generation process. The 3D modeling data generation process is a process for generating 3D modeling data required when modeling a three-dimensional object using the 3D modeling device 40.

[0051] Each step shown in the flowchart is executed by the 3D modeling data generation program 100, but the main body that operates the 3D modeling data generation program 100 is the CPU 11 of the terminal 10, and strictly speaking, the CPU 11 causes each of the functional units 110 to 190 constituting the 3D modeling data generation program 100 to execute each step. An example of the procedure will be described below.

[0052] Step S10: The CPU 11 executes a three-dimensional shape input process in the three-dimensional shape input unit 120. In this process, the three-dimensional shape input unit 120 reads polygon data that forms the shape of a three-dimensional object to be formed.

[0053] Step S20: The CPU 11 causes the three-dimensional shape analysis unit 130 to execute a three-dimensional shape analysis process. In this process, the three-dimensional shape analysis unit 130 analyzes the shape of the three-dimensional object formed by the polygon data read in step S10, and determines factors that may affect the stable standing of the three-dimensional object (for example, the position of the center of gravity of the three-dimensional object, the position of the center of gravity of a protruding part, or the position of the center of the volume of the three-dimensional object, etc.).

[0054] Step S30: CPU 11 causes support shape determination unit 140 to execute support shape determination processing. In this processing, support shape determination unit 140 determines the shape and position of the support, the shape of the through passage formed inside the support and the elevation difference of its entrance and exit, the volume (amount) of material poured into the through passage, the number of through passages to be formed and their positions in the height direction, etc., based on the elements determined in step S20. The amount of material poured into the through passage is determined to be a necessary and sufficient amount that can connect the three-dimensional object and the support, based on the volume of the through passage as well as the size of the gap between the exit of the through passage and the three-dimensional object facing it.

[0055] In step S30, the support shape determination unit 140 may select and apply one of a plurality of pre-patterned shapes of the through path as the shape of the through path to be formed inside the support body. In this case, the volume of the material poured into the through path is a fixed amount according to the selected pattern.

[0056] Step S40: The CPU 11 executes a shape cutting process by the shape cutting unit 150. In this process, the shape cutting unit 150 repeats a process of cutting into a flat plate (horizontally) the overall three-dimensional shape, which is a combination of the shape of the three-dimensional object formed by the polygon data read in step S10 and the shape of the support body determined in step S30, in the stacking direction (height direction).

[0057] Step S50: The CPU 11 causes the temperature prediction unit 160 and the support shape determination unit 140 to execute a through passage shape adjustment process. In this process, the temperature prediction unit 160 first estimates the modeling time of each layer including the through passage from the shape of each layer generated by cutting in step S40, and predicts the extent to which the temperature of the most downstream layer of the through passage has dropped during modeling of the most upstream layer of the through passage (the temperature difference between the most downstream layer and the most upstream layer of the through passage) based on the internal temperature of the three-dimensional modeling device 40 and the internal temperature of the discharge nozzle 44 (the temperature of the heater that warms the material), and judges whether the temperature difference is sufficient by comparing the predicted temperature difference with a preset threshold value for the temperature difference, and feeds back the result to the support shape determination unit 140.

[0058] Next, if the temperature prediction unit 160 determines that the temperature difference is insufficient, that is, if it is determined that the downstream layer of the through passage is not sufficiently cooled when the upstream layer of the through passage is modeled, the support shape determination unit 140 adjusts the shape of the through passage (particularly the height (number of layers) between the upstream layer and the downstream layer of the through passage) and adjusts other parameters related to the through passage accordingly (for example, the volume of material to be poured, etc.). By making such adjustments, it becomes possible to pour material into a through passage whose downstream layer has been sufficiently cooled during modeling.

[0059] Step S60: CPU 11 causes cross-sectional shape analysis unit 170 to update the layer to be processed. Specifically, cross-sectional shape analysis unit 170 sets the layers resulting from cutting the three-dimensional shape in step S40, one by one from the bottom, as the target of the subsequent process (step S70). Therefore, when step S60 is executed for the first time, the bottommost layer of the three-dimensional shape is set as the target of the process.

[0060] Step S70: The CPU 11 causes the cross-sectional shape analysis unit 170 and the path determination unit 180 to execute a layer modeling data generation process. In this process, the cross-sectional shape analysis unit 170 analyzes the shape of the layer (hereinafter, referred to as the "target layer") set as the target in step S60, and the path determination unit 180 generates command data optimized for modeling the target layer. The details of the layer modeling data generation process will be described later with reference to another drawing.

[0061] Step S80: The CPU 11 makes the cross-sectional shape analysis unit 170 check whether or not there remains an unprocessed layer, that is, a layer that has not yet been subjected to the layer forming data generation process (step S70). If there remains an unprocessed layer (step S80: Yes), the CPU 11 returns to step S60 and repeatedly executes the subsequent steps. On the other hand, if there remains no unprocessed layer (step S80: No), the CPU 11 proceeds to step S90.

[0062] Step S90: CPU 11 causes generated data output unit 190 to execute a generated data output process. In this process, generated data output unit 190 outputs, as data for 3D printing, a set of command data generated by executing step S70 for all layers constituting the 3D shape.

[0063] When the above procedures are completed, the CPU 11 ends the generation of the 3D printing data for the 3D object to be printed and the support body that supports the 3D object.

[0064] The above procedure example is merely an example, and is not limited thereto. For example, in the above procedure example, in addition to the shape and position of the support, the support shape determination process (step S30) also determines the through passage formed inside the support, and the through passage shape adjustment process (step S50) predicts the temperature difference between the most upstream layer and the most downstream layer of the through passage based on the shape of each layer cut in the shape cutting process (step S40) and adjusts the shape of the through passage as necessary. However, instead of this, the shape of the through passage may not be determined in the support shape determination process (step S30), and the through passage shape adjustment process (step S50) may determine the shape of the through passage so that the lower part of the through passage is located in a sufficiently cooled position based on the temperature prediction result.

[0065] [Data generation process for layered modeling] 7 is a flowchart showing an example of the procedure of the layer-modeling data generation process. The layer-modeling data generation process is executed in the process of the 3D modeling data generation process (step S70 in FIG. 6). The procedure will be described below along with the example.

[0066] Step S71: The CPU 11 analyzes the cross-sectional shape by the cross-sectional shape analysis unit 170. More specifically, the cross-sectional shape analysis unit 170 analyzes the shapes of the three-dimensional object and the support in the target layer.

[0067] Step S72: The CPU 11 causes the path determination unit 180 to determine a path. More specifically, the path determination unit 180 determines a path for forming the target layer, that is, a path (the movement path of the discharge nozzle 44), the discharge amount (layer pitch) and movement speed of the material on the path, the order of drawing lines along the path (the order of the discharge nozzle 44 moving along each path), and the like, based on the shape of the target layer analyzed in step S71.

[0068] In addition, for a layer including a through passage, a path may be determined so that the filling rate of the lines forming the through passage and its periphery is 100%, while the filling rate of the other lines is reduced (for example, the lines are drawn in a grid pattern to create some gaps). This allows the area around the through passage to be completely filled with material during modeling, leaving no gaps, and it is possible to prevent the material poured into the through passage from leaking out of the gaps. Also, in each layer including a through passage, a path may be determined so that the lines forming the through passage are drawn before the other lines. This allows the temperature of the material forming the through passage to be reduced more quickly during modeling.

[0069] Step S73: The CPU 11 makes the path determination unit 180 confirm whether the target layer corresponds to the most upstream layer of the through passage formed inside the support. If the target layer corresponds to the most upstream layer of the through passage (Step S73: Yes), the CPU 11 proceeds to Step S74. On the other hand, if the target layer does not correspond to the most upstream layer of the through passage (Step S73: No), the CPU 11 proceeds to S75.

[0070] Step S74: The CPU 11 adds a command to pour material into the through passage after completing the modeling of the most upstream layer of the through passage. In this command, the volume of the material to be poured into the through passage is determined in advance by the support shape determination unit 140, specifically, the volume determined or adjusted in steps S30 and S50 in FIG. 6.

[0071] Step S75: The CPU 11 causes the path determination unit 180 to execute a command data generation process. In this process, the path determination unit 180 generates command data corresponding to the path determined in step S72 and the command added in step S74.

[0072] When the above procedure is completed, the CPU 11 ends the generation of command data for one layer (target layer). This procedure is repeatedly executed for all layers.

[0073] [Design of the passageway] FIG. 8 is a diagram illustrating the through passage TH formed inside the support body SP.

[0074] FIG. 8(A): A vertical cross-sectional view showing the shape of the through passage TH in the extension direction (VIII in FIG. 4) A -VIII A The support member SP is provided with a through passage TH formed in a substantially L-shape from an inlet HI facing upward to an outlet HO facing sideways. The overall height L of the L-shaped through passage TH is T For example, the height of the outlet HO, L H The height L of the passage TH is set to about 2 to 2.5 times (2 times in the illustrated example). T is not limited thereto, and may have various different dimensions depending on the shape of the through passage TH.

[0075] FIG. 8B is a vertical cross-sectional view (VIII in FIG. 4) showing the radial shape of the through passage TH (hereinafter referred to as the "cross-sectional shape"). B -VIII B 4B). For example, if the cross-sectional shape of the through passage TH is approximately circular as shown in FIG. 4B, when forming the layer including the through passage, the line drawn is gradually shifted from the line drawn in the layer immediately below, or gradually overhangs at an inclination of 45 degrees or less, so that the cross-sectional shape is approximately circular. In the illustrated example, the through passage is formed with a layer pitch of 0.1 mm using a discharge nozzle with an approximately circular cross section and an inner diameter of 0.4 mm. The height L of the cross section of the through passage TH is H That is, the height of the outlet HO L H , and the cross-sectional width L W is set to, for example, about 0.4 to 0.6 mm.

[0076] The cross-sectional shape and thickness of the through passage TH do not need to be constant, and may vary depending on the position of the through passage TH. The cross-sectional shape of the through passage TH is not limited to a substantially circular shape, and may be changed as appropriate depending on the situation, for example, to a substantially rectangular shape, a substantially triangular shape, a substantially elliptical shape, or the like.

[0077] 8C: The three-dimensional object OB to be molded, the support SP for supporting it, and the discharge nozzle 44 are cut in the same direction as in FIG. 8A, and the material MM is poured into the through passage TH. S is set to a value that exceeds the dimensional error that may occur during modeling using the FFF method (for example, approximately 0.3 mm).

[0078] The three-dimensional object OB and the support body SP are molded together, and when the molding of the most upstream layer LT including the upper end of the through passage TH formed inside the support body SP is completed, the nozzle 44 moves so as to align the discharge hole 46 with the center of the inlet HI while blocking the inlet HI with its tip. Then, the material MM is forcefully discharged from the discharge hole 46 under a condition in which the internal pressure is higher than when the layer was molded, so that the material MM mostly fills the through passage TH and then overflows from the outlet HO, adhering to the side of the three-dimensional object OB while connected to the through passage TH, and cools and solidifies over time.

[0079] At this time, the layer of the three-dimensional object OB to which the material MM is attached is modeled at roughly the same time as the layer forming the lower part of the through passage TH, and therefore, by the time the material MM is poured into the through passage TH, it has already cooled sufficiently, so that the attached material MM is unlikely to become integrated with these layers of the three-dimensional object OB even when it solidifies. Therefore, during modeling, the three-dimensional object OB can be supported by the support body SP to prevent it from wobbling or tipping over, and after modeling, the support body SP can be easily removed from the three-dimensional object OB.

[0080] FIG. 9 is a diagram showing various modified examples of the shape of the through passage TH. Although the through passage TH described above has a substantially L-shape in the extension direction, the shape of the through passage TH is not limited to this. The through passage TH only needs to have at least an inlet for the material MM at a position higher than an outlet, and an outlet at a position facing the three-dimensional object.

[0081] For example, as shown in FIG. 9(A), the bent portion of the through passage TH may be formed in an inclined shape instead of a right angle, or as shown in FIG. 9(B), the through passage TH may be formed in a linear shape penetrating from above to the side. Also, as shown in FIG. 9(C), when the three-dimensional object OB has a shape inclined downward, the support SP may be formed in an upward inclined shape so as to face it, and a substantially J-shaped through passage TH may be formed inside it, and the material MM may be attached to the side surface of the three-dimensional object OB from below. Although not shown, the through passage TH may be branched into two or more branches along the way. In any shape of the through passage TH, the cross-sectional shape (thickness) may not be constant.

[0082] FIG. 10 is a diagram for explaining how to use the through passage TH when the upper end portion thereof is made into a countersunk shape. 10(A), when a countersink CB is formed at the upper end of the through passage TH, the material MM is poured into the through passage TH after the modeling of the layer including the countersink CB is completed. By forming the through passage TH in this manner, the internal pressure of the discharge nozzle 44 can be adjusted using the countersink CB during modeling.

[0083] Specifically, first, as shown in Fig. 10(B), with the tip of the discharge nozzle 44 blocking the inlet HI, the internal pressure is increased compared to when the layer was being formed and the material MM is forcefully discharged from the discharge hole 46, thereby filling the through passage TH with the material MM. After that, the discharge nozzle 44 is moved slightly upward, and as shown in Fig. 10(C), the material MM is discharged while decreasing the internal pressure so as to fill the countersunk CB, thereby making it possible to return the internal pressure of the discharge nozzle 44 to an internal pressure suitable for forming the layer before starting to form the next layer.

[0084] Fig. 11 is a diagram showing an example in which a through passage TH is formed inside a support SP, which is a so-called general support area that serves as a base for supporting a part suspended in the air when the part is modeled. For visibility, the three-dimensional object OB is shown shaded in Fig. 11.

[0085] For example, as shown in Fig. 11(A), when forming a three-dimensional object OB having an arm-like portion extending to the right from the middle of a columnar portion extending upward, so to speak, in a roughly U-shaped manner, a support body SP is usually formed to support the arm-like portion from below. In such a support body SP, as shown in Fig. 11(B), a through passage TH is formed inside, and after forming the uppermost layer LT including the upper end of the through passage TH, material MM is poured into the through passage TH, so that the material MM overflows from the exit of the through passage TH and adheres to the side of the columnar portion of the three-dimensional object OB and solidifies. As a result, the support body SP can support the columnar portion extending upward from the side during the formation of the columnar portion, stabilizing the standing of the portion and preventing it from wobbling or falling over.

[0086] 12 shows various examples of the positions and numbers of supports SP to be installed on a three-dimensional object OB. Among these, (A-1), (B-1), and (C-1) are perspective views showing examples of the shape of the three-dimensional object OB, and (A-2), (B-2), and (C-2) are plan views showing the state of the three-dimensional object OB shown immediately before immediately after it has been formed.

[0087] In the example of Fig. 4 described above, since the three-dimensional object OB is a thin plate-like test piece having a long length in the stacking direction, two supports SP are installed so as to sandwich it from both sides in the thickness direction so as to stably support it. In contrast, when the three-dimensional object OB has an axisymmetric shape as shown in Fig. 12 (A-1), for example, as shown in Fig. 12 (A-2), the supports SP can be installed one by one at positions that are three-fold symmetric with respect to the central axis, and the three-dimensional object OB can be supported from three directions. Note that the three-fold symmetry is not limited, and the supports SP may be installed one by one at positions that are rotationally symmetric with respect to the central axis.

[0088] In the case where the three-dimensional object OB is a rectangular parallelepiped extending upward as shown in (B-1) of Fig. 12, for example, supports SP can be installed at positions facing each of the four sides to support the three-dimensional object OB from four directions as shown in (B-2) of Fig. 12. Also, in the case where the three-dimensional object OB has a stable shape at the bottom but has a part at the top that extends high on only one side as shown in (C-1) of Fig. 12, and there is a risk that the center of gravity will shift to one side due to the shape of this part, making it unstable to stand up, as shown in (C-2) of Fig. 12, a support SP can be installed at a position facing the part that causes this and supports this part, thereby preventing the three-dimensional object OB from wobbling or falling over.

[0089] 13 is a diagram showing modified examples of the position of the through passage TH (outlet HO) formed inside the support body SP. As described above, one or more through passages TH are formed inside the support body SP, and the outlets HO are provided on the surface of the support body SP facing the three-dimensional object OB (hereinafter referred to as the "facing surface"), but the formation position of the through passage TH and therefore the installation position of the outlet HO can be modified in various ways.

[0090] For example, as shown in Fig. 13(A), a plurality of through passages TH may be formed at positions that are approximately equally spaced in the height direction along the approximate center in the width direction of the opposing surface. Alternatively, as shown in Fig. 13(B), two through passages TH may be formed at the same height position on the opposing surface, one through passage TH may be formed at a position above this position with a predetermined distance therebetween, and two through passages TH may be formed at positions above this position with a predetermined distance therebetween, in such a manner that the number of through passages TH is changed alternately from 2 to 1 to 2 to 1 to ... at positions that are approximately equally spaced in the height direction. Alternatively, as shown in Fig. 13(C), the through passages TH may be formed one by one in a zigzag pattern at positions that are approximately equally spaced in the height direction on the opposing surface.

[0091] In addition, although not shown in the figure, it is also possible to determine the formation position of the through passage TH based on the position of the center of gravity of the three-dimensional object OB. For example, the position of the center of gravity of the three-dimensional object OB alone is calculated, and the through passage TH is formed at a position below that height. During modeling, the three-dimensional object OB is supported by the support body SP via the material poured into the through passage TH. Therefore, when forming a plurality of through passages TH, next, the position of the center of gravity of the three-dimensional object OB in a state in which it is supported using the first through passage TH is calculated, and the second through passage TH is formed at a position below that height. In this way, the position of the center of gravity of the three-dimensional object OB may be calculated, and one or more through passages TH may be formed at a position according to the result. Note that the position of the center of gravity of the three-dimensional object OB is calculated by the above-mentioned three-dimensional shape analysis unit 130, and the formation position of the through passage TH according to the calculated position is determined by the above-mentioned support shape determination unit 140.

[0092] [Application example of a support having a through passage] FIG. 14 is a diagram for explaining a further example of use of the support SP.

[0093] In the examples described so far, a support SP having an internal through passage TH was installed to support a three-dimensional object OB having a shape that is prone to wobbling or tipping over, but a similar support SP can also be used when forming a three-dimensional object OB having a stable shape.

[0094] Figure 14 (A): A perspective view showing the state of a three-dimensional object OB immediately after it has been formed. The three-dimensional object OB shown in the figure has a wide and stable shape on the top and bottom surfaces, but it is assumed that after formation, it will be necessary to cut the wall on the back side slightly to make it smooth. When forming such a three-dimensional object OB, a raft RA is first formed on the forming table 42, and then the three-dimensional object OB and an appropriate number of supports SP to support it are formed on the raft RA. The supports SP are provided at a position opposite the area to be cut, in the illustrated example, at a position facing the front of the three-dimensional object OB. Once formation is complete, the object together with the raft RA is transferred to a cutting device.

[0095] FIG. 14B: Plan view showing the state in which the model is transferred to the cutting device. The cutting device is not shown. The model is fixed to the cutting device via positioning holes PH provided at the four corners of the raft RA, and then a part of the wall CP on the back side is cut. At this time, the impact from the cutting is usually transmitted to the three-dimensional object OB, causing it to vibrate, which may cause the three-dimensional object OB to peel off from the raft RA, and in that case, there is a risk of damaging the parts that are not to be cut. In contrast, if a support body SP that supports the three-dimensional object OB is installed, the support of the support body SP can suppress the vibration of the three-dimensional object OB, and as a result, it is possible to prevent the three-dimensional object OB from peeling off from the raft RA.

[0096] The present invention is not limited to the above-described embodiment, and can be modified in various ways. In addition, the various numerical values ​​given in the embodiment are merely examples, and the present invention is not limited to these numerical values.

[0097] In the above-described embodiment, the discharge nozzle 44 having the discharge hole 46 with a substantially circular cross section is used for the molding, but the cross-sectional shape of the discharge hole 46 is not limited to a substantially circular shape. For example, it may be a rectangle or a rhombus. [Explanation of symbols]

[0098] 10 Terminal 11 CPU 20 Network 30 Printer Server 40 Three-dimensional modeling equipment 42 Modeling stand 44 Discharge nozzle 46 Discharge hole 100 Data generation program for 3D modeling

Claims

1. A three-dimensional modeling data generation program for generating data used by an apparatus for stacking model materials to form a three-dimensional object, comprising: On the computer, A command generation step of generating data for generating a command to generate data for instructing the flow of a predetermined amount of model material into the through passage after forming the layer forming the entrance, by forming the shape of a three-dimensional object to be modeled and the shape of a support body for supporting the three-dimensional object, the support body having a through passage therein, the through passage having an entrance facing upward and an exit facing the three-dimensional object at a position lower than the entrance, along a path determined for each layer divided into a plurality of layers. A program for generating data for three-dimensional modeling.

2. 2. The three-dimensional modeling data generation program according to claim 1, a support shape determination step of determining a shape and a position of the support based on the shape of the solid body; a temperature prediction step of calculating a time required for modeling each of a plurality of layers obtained by dividing the shape of the three-dimensional object and the shape of the support, and predicting a temperature decrease of each layer during modeling; A through passage shape determination step of determining a shape of the through passage so that a temperature difference between the layer forming the inlet and the layer forming the outlet at the time when the model material is poured into the through passage is equal to or greater than a predetermined threshold value based on the prediction result in the temperature prediction step; A program for generating data for three-dimensional modeling, the program being executed prior to the command generating step.

3. 3. The three-dimensional modeling data generation program according to claim 2, In the through passage shape determination step, The predetermined amount is determined based on a shape of the through passage.

4. 4. The three-dimensional modeling data generation program according to claim 2, In the through passage shape determination step, A data generation program for three-dimensional modeling, characterized in that a position of the through passage in the support is determined taking into account factors that affect the stable standing of the three-dimensional object.

5. A method for manufacturing a three-dimensional object using an apparatus for forming a three-dimensional object by stacking model materials, comprising the steps of: a command generation process for generating data for generating commands to model the shape of a three-dimensional object to be modeled and the shape of a support body for supporting the three-dimensional object, the support body having a through passage therein, the through passage having an entrance facing upward and an exit facing the three-dimensional object at a position lower than the entrance, along a path determined for each layer that is divided into a plurality of layers, and to pour a predetermined amount of model material into the through passage after the layer that forms the entrance has been modeled; a modeling process for modeling the three-dimensional object and the support by causing the apparatus to model each of the layers according to the data; a removal step of removing the shaped support; A method for producing a three-dimensional object comprising the steps of:

6. The method for producing a three-dimensional object according to claim 5 , a support shape determination step of determining a shape and a position of the support based on the shape of the solid body; a temperature prediction step of calculating a time required for modeling each of a plurality of layers obtained by dividing the shape of the three-dimensional object and the shape of the support into a plurality of layers, and predicting a temperature decrease of each layer during modeling; A through passage shape determination process for determining a shape of the through passage based on a prediction result in the temperature prediction process so that a temperature difference between the layer forming the inlet and the layer forming the outlet at the time when the model material is poured into the through passage is equal to or greater than a predetermined threshold value; The method for manufacturing a three-dimensional object further includes a step before the command generating step.

7. The method for producing a three-dimensional object according to claim 6, In the through passage shape determination process, The method for manufacturing a three-dimensional object, comprising determining the predetermined amount based on a shape of the through passage.

8. The method for producing a three-dimensional object according to claim 6 or 7, In the through passage shape determination process, A method for manufacturing a three-dimensional object, comprising determining a position of the through passage in the support, taking into account factors that affect the stable standing of the three-dimensional object.

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