JP7063034B2 - Laminated modeling method - Google Patents

Description

The present invention relates to a laminated modeling method, and more particularly to a laminated modeling method for producing a modeled object by repeatedly laminating and melt-bonding powders.

In recent years, a laminated molding apparatus that manufactures a three-dimensionally shaped laminated molded product by irradiating a powder made of an inorganic material or an organic material with a light beam and sintering or melting and solidifying it has been in the limelight. Specifically, a step of spreading powder on a surface plate to form a powder layer, and a step of irradiating a predetermined region of the powder layer with a light beam and sintering or melt-solidifying the powder layer to form a hardened layer. And repeat. As a result, it is possible to manufacture a three-dimensionally shaped object by laminating and integrating a large number of cured layers.

In addition, in the laminated modeling method, in order to reduce the modeling volume while maintaining the required functions and performance of the modeled object, for the purpose of reducing the weight of the modeled object, shortening the modeling time, reducing the materials used (cost reduction), etc. In addition, phase optimization (topology optimization) is also adopted.
Here, topology optimization is "phase optimization" that optimizes the phase of a structure as a design variable, and is a design space set under assumed structural constraints, load conditions, and constraint conditions. It finds the most efficient distribution of materials in (areas where materials can be distributed). Patent Document 1 discloses a laminated modeling method for optimizing the topology in the production of a three-dimensionally shaped object.

Japanese Unexamined Patent Publication No. 2008-231490

The inventors have found the following problems in the case of topology optimization regarding a laminated modeling method for producing a modeled object by repeating laminating and melt-bonding powders.

In general, topology optimization for a model results in the most efficient distribution of materials, that is, the removal (lightening) of parts or parts that were solid structures. New shapes and internal structures such as irregularities, cavities and spaces appear.
By utilizing this newly formed unevenness and space and installing equipment (functional equipment) to exert various functions such as measurement, cooling or heating, vibration, fluid flow control, etc., conventional In some cases, it may be possible to exert a function in a part where it was difficult to exert a function, or to exert a function with higher accuracy and efficiency.

However, due to the unevenness and space, the newly formed shape and the surface shape of the internal structure become complicated, and functions such as "the plane (or dimensions) necessary for stable fixing" are obtained. Depending on the mounting specifications of the equipment, it may be difficult to mount.

The present invention has been made in view of the above problems, and provides a laminated modeling method capable of mounting a functional device at a desired position while reducing the modeling volume of a modeled object.

The laminated modeling method according to the present invention is a laminated modeling method for producing a three-dimensional shaped object by repeating laminating and melt-bonding powders, and is a step of acquiring three-dimensional data of the shaped object and acquisition. It is equipped with a process of topologically optimizing the 3D data, and forms a base for arranging functional equipment on the modeled object for the 3D data before or after the topology is optimized. do.

In the laminated modeling method according to the present invention, a base portion for arranging functional equipment on a modeled object is formed for three-dimensional data before or after topology optimization. Therefore, it is possible to provide a laminated modeling method capable of mounting a functional device at a desired position while reducing the modeling volume of the modeled object.

According to the present invention, the functional device can be attached to a desired position while reducing the modeling volume of the modeled object.

It is a schematic sectional drawing which shows the outline of the laminated modeling apparatus used in the laminated modeling method which concerns on embodiment. It is a block diagram which shows the structure of the control device used for the laminated modeling method which concerns on embodiment. It is a figure which exemplifies the modeled object manufactured by the laminated modeling method which concerns on embodiment. It is a flowchart which shows the laminated modeling method which concerns on embodiment. It is a flowchart which shows the detail of the process of step S20 in the flowchart shown in FIG. It is a schematic cross-sectional view of the modeled product manufactured by the laminated modeling method according to the embodiment. It is a schematic cross-sectional view of the other model manufactured by the laminated modeling method according to the embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiments. Further, in order to clarify the explanation, the following description and drawings are appropriately simplified.
As a matter of course, the right-handed xyz coordinates shown in FIGS. 1, 6 and 7 are for convenience in explaining the positional relationship of the components. Usually, the z-axis plus direction is vertically upward, and the xy plane is a horizontal plane.

(Embodiment)
First, with reference to FIG. 1, a laminated modeling apparatus used in the laminated modeling method according to the embodiment will be described. FIG. 1 is a schematic cross-sectional view showing an outline of the laminated modeling apparatus 1 according to the embodiment. As shown in FIG. 1, the laminated modeling apparatus 1 used in the laminated modeling method according to the embodiment includes a base 30, a surface plate 2, a modeling tank 3, a modeling tank support portion 4, a modeling tank drive unit 5, a support column 6, and a support. A unit 7, a laser scanner 8, an optical fiber 9, a laser oscillator 10, a squeegee 11, a gutter 12, a powder distributor 13, a powder supply unit 14, and a control device 100 are provided.

The base 30 is a base for fixing the surface plate 2 and the support column 6. The base 30 is installed on the floor so that the upper surface on which the surface plate 2 is placed is horizontal. The surface plate 2 is placed and fixed on the horizontal upper surface of the base 30. The upper surface of the surface plate 2 is also horizontal, and powder is spread on the upper surface of the surface plate 2 to form a three-dimensional shaped object 50. In the example of FIG. 1, the surface plate 2 is a square columnar member. As shown in FIG. 1, a flange-shaped convex portion 2a overhanging in the horizontal direction is formed on the entire peripheral edge of the upper surface of the surface plate 2. Since the outer peripheral surface of the convex portion 2a is in contact with the inner surface of the modeling tank 3 as a whole, the laminated powder 51 can be held in the space surrounded by the upper surface of the surface plate 2 and the inner surface of the modeling tank 3. can. Here, by providing a sealing member (not shown) made of felt, for example, on the outer peripheral surface of the convex portion 2a in contact with the inner surface of the modeling tank 3, the holding power of the laminated powder 51 can be enhanced.

The modeling tank 3 is a tubular member that holds the powder spread on the upper surface of the surface plate 2 from the side surface. In the example of FIG. 1, since the surface plate 2 has a square columnar shape, the modeling tank 3 is a square pipe having a flange portion 3a at the upper end. The modeling tank 3 is made of, for example, a stainless steel plate having a thickness of about 1 to 6 mm (preferably about 3 to 5 mm) and is lightweight. A powder layer is formed at the upper open end 3b of the modeling tank 3, and a cured layer is formed by irradiating the powder layer with a laser beam LB. The shape of the upper opening end 3b is, for example, 600 mm × 600 mm.

Further, the modeling tank 3 is installed so as to be movable in the vertical direction (z-axis direction). As will be described in detail later, each time a hardened layer is formed, the modeling tank 3 is raised by a fixed amount with respect to the surface plate 2 to form the modeled object 50. Here, in the laminated modeling apparatus 1 according to the embodiment, only the modeling tank 3 having a constant weight and light weight needs to be raised. Therefore, the powder layer can be formed with high accuracy every time. As a result, the modeled object 50 can be formed with high accuracy.

The modeling tank support portion 4 is a support member that supports the lower surface of the flange portion 3a at three points so that the upper surface of the flange portion 3a of the modeling tank 3 is horizontal. The modeling tank support portion 4 is connected to a connecting portion 5c of a modeling tank driving unit 5 that moves the modeling tank 3 in the vertical direction (z-axis direction).

The modeling tank drive unit 5 is a drive mechanism for moving the modeling tank 3 in the vertical direction (z-axis direction). The modeling tank drive unit 5 includes a motor 5a, a ball screw 5b, and a connecting unit 5c. When the motor 5a is driven, the ball screw 5b extended in the z-axis direction rotates. Then, when the ball screw 5b rotates, the connecting portion 5c moves in the vertical direction (z-axis direction) along the ball screw 5b. As described above, since the modeling tank support portion 4 that supports the modeling tank 3 is connected to the connecting portion 5c, the modeling tank 3 can be moved in the vertical direction (z-axis direction) by the modeling tank driving unit 5. The drive source of the modeling tank drive unit 5 is not limited to the motor, and a hydraulic cylinder or the like may be used.

Here, the modeling tank drive unit 5 is fixed to the upper part of the support column 6 which is erected substantially vertically (that is, in the vertical direction) from the base 30. As described above, in the laminated modeling apparatus 1 according to the present embodiment, since the modeling tank driving unit 5 is installed outside the modeling tank 3, it is excellent in maintainability.

The laser scanner 8 irradiates the powder layer formed at the upper open end 3b of the modeling tank 3 with the laser beam LB. The laser scanner 8 has a lens and a mirror (not shown). Therefore, as shown in FIG. 1, the laser scanner 8 can focus the laser beam LB on the powder layer regardless of the position on the horizontal plane (xy plane) in the powder layer.
Here, the laser beam LB is generated in the laser oscillator 10 and introduced into the laser scanner 8 via the optical fiber 9.

Further, the laser scanner 8 is fixed to the flange portion 3a of the modeling tank 3 via the support portion 7. Therefore, the distance between the laser scanner 8 and the powder layer to be irradiated by the laser beam LB can be kept constant. Therefore, the laminated modeling device 1 according to the embodiment can manufacture the modeled object 50 with high accuracy.

The squeegee 11 is composed of a first squeegee 11a and a second squeegee 11b. Both the first squeegee 11a and the second squeegee 11b extend in the y-axis direction. Further, the squeegee 11 can slide in the x-axis direction from one flange portion 3a to the facing flange portion 3a via the upper opening end 3b of the modeling tank 3.

As shown in FIG. 1, powder is supplied between the first squeegee 11a and the second squeegee 11b in a state of being installed on the flange portion 3a on the minus side of the x-axis. Here, the powder for forming the powder layer for two times is supplied. That is, by sliding the squeegee 11 from the flange portion 3a on the minus side of the x-axis to the flange portion 3a on the plus side of the x-axis, one powder layer is formed at the upper open end 3b of the modeling tank 3. As shown by the broken line in FIG. 1, the squeegee 11 stands by on the flange portion 3a on the plus side of the x-axis while the powder layer is irradiated with the laser beam LB to form the cured layer. Then, by sliding the squeegee 11 from the flange portion 3a on the plus side of the x-axis to the flange portion 3a on the minus side of the x-axis, another powder layer is formed at the upper opening end 3b of the modeling tank 3.

For example, when the hardened layer forming region is narrow, the hardened layer forming region is covered without sliding the squeegee 11 from the flange portion 3a on the minus side of the x-axis to the flange portion 3a on the plus side of the x-axis as much as possible. You may stop the slide in the middle of the above. The amount of powder for forming the powder layer can be saved and the time can be shortened.

The gutter 12 and the powder distributor 13 are for uniformly distributing the powder dropped from the powder supply unit 14 in the longitudinal direction of the squeegee 11. On the lower surface of the gutter 12, there is an opening that is narrower than the distance between the first squeegee 11a and the second squeegee 11b (in the x-axis direction) and has a length (y-axis direction) comparable to that of the powder charging region of the squeegee 11. It is formed.

The powder distributor 13 is a plate-shaped member having the same cross-sectional shape as the groove of the gutter 12. The powder distributor 13 can be slid in the y-axis direction by a drive mechanism (not shown). Here, in FIG. 1, the powder distributor 13 is drawn away from the gutter 12 for the sake of clarity. However, in reality, the powder distributor 13 slides while being in close contact with both side surfaces of the groove of the gutter 12. The powder distributor 13 slides from one end to the other end of the gutter 12 where the powder is dropped, so that the powder is uniformly distributed in the longitudinal direction (y-axis direction) of the squeegee 11 through the opening of the gutter 12. To.

For example, when the formed region of the cured layer is narrow, the powder distributor 13 is not slid from one end to the other end of the gutter 12 as much as possible, the formed region of the cured layer is covered, and the slide is stopped in the middle. You may. The amount of powder for forming the powder layer can be saved and the time can be shortened.

The powder supply unit 14 is a small tank in which powder is stored. The details of the powder supply unit 14 will be described later. The powder is made of an inorganic material (metal or ceramic) or an organic material (plastic). Preferably, iron powder having an average particle size of about 20 μm is used.

The control device 100 controls the operation of the laminated modeling device 1. Specifically, the control device 100 is connected to the modeling tank drive unit 5, the laser scanner 8, the laser oscillator 10, the squeegee 11, and the like by wire or wirelessly. The control device 100 stores three-dimensional data for manufacturing the modeled object 50. The control device 100 uses the three-dimensional data to control these components. As a result, the laminated molding apparatus 1 forms the modeled object 50.

FIG. 2 is a block diagram showing a configuration of a control device 100 used in the laminated modeling method according to the embodiment. The control device 100 is, for example, a computer. The control device 100 has a CPU (Central Processing Unit) 102, a ROM (Read Only Memory) 104, a RAM (Random Access Memory) 106, and an interface unit 108 (IF; Interface) as a main hardware configuration. .. The CPU 102, ROM 104, RAM 106, and interface unit 108 are connected to each other via a data bus or the like.

The CPU 102 has a function as an arithmetic unit that performs control processing, arithmetic processing, and the like. The ROM 104 has a function for storing a control program, an arithmetic program, and the like executed by the CPU 102. The RAM 106 has a function for temporarily storing processing data and the like. The interface unit 108 inputs / outputs signals to and from the outside via wired or wireless. The interface unit 108 may include a communication port.

Further, the control device 100 includes a three-dimensional data acquisition unit 112, an internal structure examination unit 114, a three-dimensional data correction unit 116, and a laminated modeling control unit 118. The three-dimensional data acquisition unit 112, the internal structure examination unit 114, the three-dimensional data correction unit 116, and the laminated modeling control unit 118 can be realized, for example, by the CPU 102 executing a program stored in the ROM 104. Further, by recording the necessary program on an arbitrary non-volatile recording medium and installing it as necessary, the 3D data acquisition unit 112, the internal structure examination unit 114, the 3D data correction unit 116, and the laminated modeling control can be performed. The unit 118 may be realized.

Programs can also be stored and supplied to a computer using various types of non-transitory computer readable medium. Non-temporary computer-readable media include various types of tangible storage media. Examples of non-temporary computer-readable media include magnetic recording media (eg, flexible disks, magnetic tapes, hard disk drives), magneto-optical recording media (eg, magneto-optical disks), CD-ROMs, CD-Rs, CD-R / Ws. , Including semiconductor memory (eg, mask ROM, PROM (Programmable ROM), EPROM (Erasable PROM), flash ROM, RAM). The program may also be supplied to the computer by various types of transient computer readable medium. Examples of temporary computer readable media include electrical, optical, and electromagnetic waves. The temporary computer-readable medium can supply the program to the computer via a wired communication path such as an electric wire and an optical fiber, or a wireless communication path.

The three-dimensional data acquisition unit 112, the internal structure examination unit 114, the three-dimensional data correction unit 116, and the laminated modeling control unit 118 are not limited to being realized by software as described above, and some hardware such as circuit elements is used. It may be realized by hardware. Further, the three-dimensional data acquisition unit 112, the internal structure examination unit 114, the three-dimensional data correction unit 116, and the laminated modeling control unit 118 do not need to be physically provided in one device, but are as separate hardware. It may be configured. In that case, each of the three-dimensional data acquisition unit 112, the internal structure examination unit 114, the three-dimensional data correction unit 116, and the laminated modeling control unit 118 may function as a computer.

Specific functions of the three-dimensional data acquisition unit 112, the internal structure examination unit 114, the three-dimensional data correction unit 116, and the laminated modeling control unit 118 will be described later. The process performed by the internal structure study unit 114 does not have to be performed by a device such as a computer, and may be performed by an operator. Further, the control device 100 does not have to be integrated with the laminated modeling device 1, and may not be a dedicated device for the laminated modeling device 1. The control device 100 may be a general-purpose information terminal.

Here, the modeled object 50 manufactured by using the laminated modeling method of the present embodiment will be described with reference to FIG.
FIG. 3 is a diagram illustrating a modeled object 50 manufactured by the laminated modeling method according to the embodiment. FIG. 3 is a cross-sectional view of the modeled object 50. The modeled object 50 illustrated in FIG. 3 can be manufactured using the three-dimensional data acquired by the three-dimensional data acquisition unit 112. The model 50 according to the embodiment is, for example, a mold having a cooling circuit. As shown in FIG. 3, the modeled object 50 according to the embodiment is, for example, a mold having a hollow path 60 constituting a cooling circuit inside. In this case, the three-dimensional data of the modeled object 50 includes the information of the path 60.

Next, with reference to FIG. 4, a series of flow of the laminated modeling method will be described.
FIG. 4 is a flowchart showing the laminated modeling method according to the embodiment. The laminated modeling method according to the embodiment may be performed by, for example, using a prototype produced based on three-dimensional data, or by computer simulation by CAE (Computer Aided Engineering). ..
First, the three-dimensional data of the modeled object is acquired (step S10). Next, the internal structure is examined (step S20). The examination of the internal structure has a plurality of steps, and the details will be described later. Next, the three-dimensional data is modified (step S30). Next, laminating modeling is performed (step S40). Finally, the residual powder is removed (step S50).

Hereinafter, each of the above steps will be described with reference to FIGS. 2 to 7.
First, it will be described with reference to FIGS. 2 to 4.
<Step S10: Acquire 3D data of the modeled object>
The three-dimensional data acquisition unit 112 acquires three-dimensional data for modeling the modeled object 50 (step S10). Specifically, the three-dimensional data acquisition unit 112 generates three-dimensional data (3D data) using CAD / CAM (Computer Aided Design / Computer Aided Manufacturing) data. The three-dimensional data acquisition unit 112 acquires three-dimensional data thereby. The three-dimensional data acquisition unit 112 may acquire the three-dimensional data by receiving the three-dimensional data generated by another device.

<Step S20: Examination of internal structure>
The internal structure examination unit 114 examines the internal structure of the modeled object 50 (step S20). Specifically, the internal structure study unit 114 uses a "path model" that simulates the path 60 using three-dimensional data before actually manufacturing the model 50, and uses the internal structure (path) of the model 50. It is determined whether or not 60) satisfies the "predetermined performance".

Here, the "path model" may be a prototype manufactured (prototype) using the three-dimensional data acquired in the step S10. Further, the "path model" may be a path reproduced by simulation in CAE analysis using the three-dimensional data acquired in the step S10.
Further, the "predetermined performance" in the present embodiment is "functional establishment" and "structural establishment", and "functional establishment" is whether or not the cooling function by the cooling water can be sufficiently exhibited. Shown and "structural feasibility" indicates whether or not the modeled object 50 can secure the required rigidity even when the modeled object 50 has a hollow path 60 inside.

Next, "topology optimization" and "fleshing process for mounting functional equipment" are performed.
In the "topology optimization", the volume of the modeled object 50 is minimized, and in the "fleshing process for attaching the functional device", the fleshing process for attaching the functional device to the convex portion formed inside the modeled object 50 is performed. conduct.

Here, in the present embodiment, "functional establishment", "structural establishment", "topology optimization", and "fleshing process for mounting functional equipment" are performed, but at least "topology optimization" and "functional equipment" are performed. The "mounting fleshing process" may be performed, in other words, the examination of "functional feasibility" and "structural feasibility" does not necessarily have to be performed.

More specific details regarding each step of step S20 will be described later.

<Step S30: Modification of 3D data>
The three-dimensional data correction unit 116 corrects the three-dimensional data acquired in the step S10 based on the topology optimization and the fleshing process performed in the step S20 (step S30). That is, in the three-dimensional data corrected by the three-dimensional data correction unit 116, the topology is optimized, the inner surface of the modeled object 50 is fleshed out, and the arrangement of the path 60 is corrected. Here, the "arrangement" includes the length, diameter, bending degree (curvature), position (including the distance from the outer surface of the model 50, branching, etc.) of the path 60 and the like. When "functional feasibility" and "structural feasibility" are examined in the process of step S20, the three-dimensional data correction unit 116 may further improve "functional feasibility" and "structural feasibility". , The three-dimensional data acquired in the step S10 may be modified. The three-dimensional data correction unit 116 may perform the correction itself of the arrangement of the route 60, or the internal structure examination unit 114 may perform the correction itself, as will be described later.

<Step S40: Laminated modeling>
The laminated modeling control unit 118 manufactures the modeled object 50 by the laminated modeling as described above using the three-dimensional data corrected in the step S30 (step S40).
<Step S50: Remove residual powder>
After manufacturing the model 50, residual powder is present inside the path 60. Residual powder is removed from the path 60 formed inside the model 50 actually manufactured in the step S40 (step S50). In the embodiment, for example, a fluid such as compressed air, water, or oil is injected into the path 60 from the inlet 60a to remove residual powder remaining in the path 60. Alternatively, for example, by sucking the air in the path 60 from the outlet 60b, the residual powder remaining in the path 60 is removed.

Hereinafter, the details of step S20 will be described with reference to FIG.
FIG. 5 is a flowchart showing the details of the process of step S20 in the flowchart shown in FIG.
[Details of step S20]
In step S20, first, a route model is arranged using the three-dimensional data acquired in the step S10 (step S210). Next, the feasibility of the function is examined (step S220). When the condition of the function is satisfied (step S222YES), the structural feasibility is examined (step S230). When the rigidity condition is satisfied (step S232YES), topology optimization is performed (step S240). Finally, a fleshing process for attaching functional equipment is performed (step S250), and the process proceeds to step S30. In the case of step S220NO and step 230NO, the process returns to step S210.

<Step S210: Arrangement of route model>
The internal structure study unit 114 arranges a route model using the three-dimensional data acquired in the step S10 (step S210). For example, when the laminated modeling method (step S20 step) is performed using a prototype, a prototype is manufactured by the laminated modeling device 1 using the three-dimensional data acquired in the step S10. As a result, a path model is formed inside the prototype of the modeled object 50. Further, for example, when the laminated modeling method (step S20 step) is performed using CAE analysis, the path model is reproduced by computer simulation using the three-dimensional data acquired in the step S10.

<Step S220: Examination of functional feasibility>
The internal structure study unit 114 examines the feasibility of the function (step S220). Then, the internal structure examination unit 114 determines whether or not the functional condition is satisfied (step S222). If the functional condition is not satisfied (NO in step S222), the process returns to step S210. On the other hand, when the functional condition is satisfied (YES in step S222), the process proceeds to step S230.

When the function exerted by the path 60 is the cooling function, the internal structure study unit 114 acquires the temperature in the high temperature region when the cooling water is circulated in the path model and molded by the mold, and the temperature thereof is obtained. Is determined to be below a predetermined temperature (step S222). Then, when the temperature is equal to or lower than the predetermined temperature, it is determined that the functional condition is satisfied (YES in step S222).

When the step of step S20 is performed using a prototype, in step S220, cooling water is circulated through a path model formed in the prototype, and molding is performed with a mold for the prototype. Then, the internal structure study unit 114 acquires the temperature of the portion corresponding to the high temperature region in the prototype at that time. The temperature can be measured, for example, by thermography. When a prototype is used, it may be determined whether or not the functional conditions are satisfied by detecting the presence or absence of a defect in the molded product or the mold.

Further, when the step of step S20 is performed using CAE analysis, in step S220, the internal structure study unit 114 performs mold molding in a state where cooling water is circulated in the path model by computer simulation by CAE. To reproduce. Then, the internal structure study unit 114 calculates the temperature in the high temperature region by the temperature analysis (cooling analysis) by CAE.

When the condition of the cooling function is not satisfied (NO in step S222), the internal structure study unit 114 changes the arrangement of the route model so as to satisfy the condition of the cooling function in the step S210. For example, the internal structure study unit 114 may increase the diameter of the path 60 near the high temperature region. Further, the internal structure examination unit 114 may further bring the path 60 closer to the high temperature region, or may provide a branch so as to newly arrange a partial route closer to the high temperature region.

In the present embodiment, the modeled object 50 is used as a mold, and the function exerted by the path 60 is a cooling function, but as another embodiment, the function exerted by the path 60 is soundproof or vibration-proof. If this is the case, the internal structure study unit 114 may determine whether the volume or the magnitude of vibration when the fluid is circulated through the path model is equal to or less than a predetermined value (step S222). Further, when the function exerted by the path 60 is an air shooter that performs transportation or the like, the internal structure study unit 114 determines whether or not the speed when the fluid is circulated through the path model and the object is conveyed is at least a predetermined speed. May be determined (step S222).

<Step S230: Examination of structural feasibility>
The internal structure study unit 114 examines the structure feasibility (step S230). Then, the internal structure examination unit 114 determines whether or not the rigidity condition is satisfied (step S232). If the rigidity condition is not satisfied (NO in step S232), the process returns to step S210. On the other hand, when the rigidity condition is satisfied (YES in step S232), the process proceeds to step S240.

Specifically, the internal structure study unit 114 acquires the amount of strain or deformation in the mold model when a load is applied to the model (mold model) of the modeled object 50 having the path model inside, and the strain or deformation amount thereof is acquired. It is determined whether or not the strain or deformation amount is equal to or less than a predetermined allowable value (step S222). Then, when the strain or deformation amount is equal to or less than a predetermined allowable value, it is determined that the rigidity condition is satisfied (YES in step S222). In step S230, the strength may be evaluated instead of the rigidity. In this case, the strength condition may be determined by using the stress value instead of the strain or deformation amount in the mold model.

When the step of step S20 is performed using a prototype, in step S230, a rigidity test is performed on the prototype in which the path model is formed. Then, the internal structure examination unit 114 acquires the amount of strain or deformation at a predetermined position at that time. The strain can be measured by attaching a strain gauge to a predetermined position. When a prototype is used, the feasibility of the structure may be determined by detecting a defect in the molded product or the mold due to insufficient rigidity of the prototype.

When the step of step S20 is performed using CAE analysis, in step S230, the internal structure study unit 114 performs structural analysis using FEM (Finite Element Method). Then, the internal structure examination unit 114 calculates the amount of strain or deformation at a predetermined position. The internal structure study unit 114 may determine whether or not the stress value indicated by the stress distribution obtained by the structural analysis is equal to or less than the allowable value. Further, thermal stress may be taken into consideration in the structural analysis.

If the condition is not satisfied (NO in step S232), the internal structure study unit 114 changes the arrangement of the route model so as to satisfy the rigidity condition in the step S210. For example, the internal structure examination unit 114 may change the arrangement of the path 60 so as to separate the path 60 from the outer surface of the modeled object 50.

<Step S240: Topology optimization>
The internal structure study unit 114 optimizes the topology of the three-dimensional data (step S240).
As an example, the modeled object 50 according to the embodiment is a mold having a hollow path 60 as a cooling circuit for circulating a fluid. Therefore, the structural constraints, load conditions and constraints assumed in the model 50 according to the embodiment are, for example, thermal stress, casting pressure, coupled nesting or neighbors predicted from the mold temperature history. Restraint by mold parts such as fitting nests, and axial force of fastening bolts. By optimizing the topology of the modeled object 50 under the constraints and conditions, the minimum modeled volume of the modeled object 50, that is, the minimum powder material can be obtained.

<Step S250: Fleshing process for mounting functional equipment>
The internal structure examination unit 114 performs a fleshing process for mounting functional equipment (step S250). The "functional device" in the embodiment is, for example, a measurement function device, a cooling or heating function device, a vibration function device, a flow control function device, or the like. Specifically, the measuring function device is a hollow path 60 through which a fluid flows, various sensors for measuring changes or conditions of a three-dimensional object, and more specifically, a temperature sensor such as a thermocouple, a strain gauge, and a flow rate. It is a total. The cooling or heating function device is a device that cools or heats a three-dimensional object, and more specifically, it is a Pelche element, a heater, or the like. The vibration function device is a vibration or sound wave generator or the like. The flow control function device is a device used when a fluid such as a cooling medium is also flowed in an internal space, and more specifically, a straightening vane plate, a turbulent flow plate, or the like. It also includes a display board as a display function device, bolts / screws, clips and holders as a fixing / holding function device, and the like.

As described above, since the modeled object 50 according to the embodiment becomes the minimum modeled volume by performing the topology optimization, in addition to the hollow path 60 already formed inside the modeled object 50, on the three-dimensional data. A new internal structure is formed in. Functional equipment can be attached or arranged on the surface of the internal structure. Here, the surface shape of the internal structure of the modeled object 50 having the minimum volume often has irregularities. In order to dispose the functional equipment on the surface of the internal structure having unevenness, the base portion is fleshed out according to the type of the functional equipment desired to be attached.

Next, with reference to FIG. 6, a case where the base portion B1 is fleshed out in order to dispose the functional equipment on the surface of the internal structure having irregularities will be described.
FIG. 6 is a schematic cross-sectional view of a modeled object 50 manufactured by the laminated modeling method according to the embodiment. As shown in FIG. 6, a base portion B1 is formed on a convex portion C1 on the surface of the internal structure by a fleshing treatment. A temperature sensor S is arranged as a functional device on the base portion B1. The modeled object 50 shown as an example in FIG. 6 has a solid structure, but as described above, it may have a hollow structure.

FIG. 6 is a specific example, and in particular, in order to measure the temperature of the apex portion of the convex portion C1 among the irregularities formed on the surface of the internal structure of the modeled object 50 by the topology optimization in step S240, the convex portion C1. It is assumed that the temperature sensor S is arranged at the apex. As shown in FIG. 6, the internal structure examination unit 114 performs a fleshing process on the convex portion C1 on the three-dimensional data, for example, to form the base portion B1. In the example of FIG. 6, the convex portion C1 is fleshed out to form a base portion B1 having a flat upper surface. A temperature sensor S is arranged on the upper surface of the base portion B1.

The shape of the base portion B1 may be a shape having a flat mounting seat, a shape having a mounting hole, a mounting groove, or the like, depending on the type of the functional device and the part where the functional device is exhibited, and has a desired shape. It can be changed as appropriate. That is, the information on the fleshing process also includes the setting of the installation dimensions.

In the fleshing process described with reference to FIG. 6 described above, the case where the measurement is desired is the apex of the convex portion has been described, but the present invention is not limited to this. For example, by using a simulation such as CAE according to the target function of the functional device, it is possible to determine the mounting portion of the functional device in the unevenness formed on the surface of the internal structure of the modeled object 50.

Specifically, when mounting a temperature sensor as a measurement function device, the temperature distribution of the internal structure is predicted using simulation, and the mounting site is determined based on the maximum or minimum temperature site, the site with a large variation width, etc. You can also do it. Further, for example, when a vibration function device for removing residual powder is attached in step S50 described above, the position where unmelted powder is likely to remain or aggregate in the hollow path 60 through which the fluid flows is predicted by simulation. It is also possible to determine the mounting site.

In the embodiment, the topology optimization (step S240) is followed by the functional equipment mounting fleshing process (step S250), but the order is not limited to this. Specifically, the topology may be optimized after adding the information of the fleshing process in which the mounting portion of the functional device and the installation dimension are determined by using a simulation such as CAE in advance.

Further, in the present embodiment, the functional device is attached to the surface of the internal structure formed by the topology optimization, but the uneven portion formed by the topology optimization on the surface such as the outer peripheral surface and the side surface of the modeled object. It is also possible to flesh out the base portion (particularly in the recess).

Further, it is also possible to perform topology optimization after determining the position of the base portion B2 to which the functional device such as the temperature sensor S is attached by using a simulation such as CAE. FIG. 7 is a schematic cross-sectional view of another modeled object 50 manufactured by the laminated modeling method according to the embodiment. FIG. 7 shows the convex portion C1 described with reference to FIG. 6 using a virtual line for reference. As shown in FIG. 7, a space is formed inside the convex portion C2 of the internal structure of the modeled object 50 as a base portion B2 for mounting a functional device. A temperature sensor S is provided as a functional device on the base portion B2. As shown in FIG. 7, in the internal structure of the modeled object 50, the convex portion C2 is formed by performing topology optimization with a space provided as the base portion B2. Further, as shown in FIG. 7, it is desirable to form an opening A for arranging a functional device such as a temperature sensor S in the base portion B2.
The above is the details of step S20.

When the inventor performs topology optimization as in the past, the surface shape of the modeled object becomes uneven, which makes it difficult to attach some functional devices such as functional devices that are difficult to attach to the uneven portion. I found the problem.

In the present embodiment, the acquired 3D data is topologically optimized, and a base portion for arranging the functional equipment on the topology-optimized model is formed for the topology-optimized 3D data. , The functional device can be attached to a desired position while reducing the modeling volume of the modeled object.

The present invention is not limited to the above embodiment, and can be appropriately modified without departing from the spirit.

1 Laminated modeling device 50 Modeled object 51 Laminated powder 60 Path 100 Control device 112 Three-dimensional data acquisition unit 114 Internal structure examination unit 116 Three-dimensional data correction unit 118 Laminated modeling control unit B1, B2 Base unit C1, C2 Convex portion S Temperature sensor

Claims (1)

It is a laminated modeling method that manufactures a three-dimensional shaped object by repeating laminating and melt-bonding powders.
The process of acquiring the three-dimensional data of the modeled object and
A process of optimizing the topology of the acquired three-dimensional data is provided.
The three-dimensional data after the topology optimization is subjected to a fleshing process for forming a base portion for arranging the functional equipment on the surface of the modeled object having the unevenness formed by the topology optimization .
Laminated modeling method.

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