JP2018094775A - Method of shaping three-dimensional object - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to inhibit deformation of a shaped object from occurring caused by excessive load being applied to the shaped object at a time of lamination.SOLUTION: The shaping method for sequentially laminating on a stage a material layer on which a structural material constituting a three-dimensional model and a support material constituting a support body for supporting the shaping of the structure are arranged to produce a shaped object based on slice data generated from shape data of a three-dimensional model, includes laminating the material layer on the shaped object produced on the stage while applying a load smaller than the load causing deformation to the shaped object manufactured on the stage.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a method for modeling a three-dimensional object.

  In recent years, as a new modeling method, a three-dimensional model that materializes a three-dimensional model by slicing shape data of a three-dimensional model into a plurality of layers, generating slice data, and sequentially stacking modeling materials based on the slice data Is attracting attention.

  Patent Document 1 proposes a modeling apparatus that forms a layer of one cross section made of a modeling material in accordance with slice data of a three-dimensional model using an electrophotographic method, and stacks the units in units of layers, that is, in units of planes. ing. In this method, an electrostatic latent image formed on a dielectric surface is developed with a chargeable powder and heated and fixed with a heat roll. Thereafter, the fixed chargeable powder layer is reheated and melted, pressure-transferred onto the stage, and laminated to form a three-dimensional object.

Japanese Patent Laid-Open No. 10-207194

  In the modeling apparatus of Patent Document 1, the chargeable powder layer is laminated by heating and pressure bonding. However, the pressure applied at this time varies depending on the shape of the three-dimensional model, the characteristics of the modeling material to be used, and the like. Therefore, if an appropriate pressure is not applied at the time of lamination, there is a concern about deformation of the modeled object.

In order to solve the above problems, the modeling method according to the present invention supports the modeling of the structural material and the structural body constituting the three-dimensional model based on slice data generated from the shape data of the three-dimensional model. A support material for forming a support body, and a modeling method for manufacturing a modeled object by sequentially laminating a material layer on a stage,
The material layer is laminated on a model manufactured on the stage while applying a load smaller than a load causing deformation of the model manufactured on the stage.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to manufacture a solid thing stably, suppressing that an excessive load is added to a shaped article and the deformation | transformation of a shaped article arises at the time of lamination | stacking.

The modeling system schematic used for description of a lamination process. The figure which shows the functional block diagram of a modeling apparatus. The flowchart for calculating the load F (h) concerning 1st Embodiment. The flowchart for calculating the load F (h) concerning 2nd Embodiment. The flowchart for calculating the load F (h) concerning 3rd Embodiment. The figure explaining modeling concerning a 3rd embodiment. The figure explaining modeling concerning a 4th embodiment.

  Embodiments of the present invention will be described below with reference to the drawings. The dimensions, materials, shapes, and relative arrangements of the components shown in each drawing should be appropriately changed according to the configuration of the apparatus to which the invention is applied and various conditions, and there is no specific description. As long as the scope of the present invention is not limited thereto.

  An embodiment of a modeling system according to the present invention will be described with reference to FIGS. The modeling system arranges the modeling material and sequentially joins the three-dimensional model based on the cross-sectional data obtained by cutting at a predetermined pitch so that the three-dimensional model becomes a plane perpendicular to the stacking direction. The corresponding three-dimensional object is manufactured.

(Overall configuration of modeling system)
The modeling system according to the present invention includes a modeling unit 100, a user interface 200, a parameter setting unit 300, and a control unit 400 that controls the operation of the modeling unit.

  The modeling unit 100 includes modeling material supply units 1 </ b> A to 1 </ b> D including the photosensitive roller 3, a first carrier 4, a second carrier (intermediate transfer body) 8, a heater 9, a temperature control member 13, a modeling stage 14, 3 A transport body 15 and a pressure (load) sensor 19 are provided. The pressure (load) sensor 19 detects the pressure (load) received by the temperature control member 13 during lamination.

  The parameter setting unit 300 receives input from the user interface 200, generates cross-sectional data based on the shape data of the three-dimensional model, and calculates and sets parameters such as pressure applied during lamination. The control unit 400 controls each unit of the modeling unit 100 based on the parameters set by the parameter setting unit 300 to perform the stacking operation.

  In the present embodiment, the vertical direction (stacking direction) is the Z-axis direction, the left-right direction is the Y-axis direction, and the direction perpendicular to the Z-axis and the Y-axis is the X-direction. To do.

  FIG. 2 is an example of a functional block diagram of the modeling apparatus of FIG. 1, and illustrates the correlation with the parameter setting unit 300 and the control unit 400 and the functions of each.

  The parameter setting unit 300 includes a data storage unit 301, a cross-section data generation unit 302, a load calculation unit 303, and a support shape calculation unit 304. The control unit 400 includes a material layer formation control unit 401, an intermediate transfer control unit 402, a heated sheeting control unit 403, and a lamination process control unit 404.

(Modeling flow)
A modeling flow will be described with reference to FIGS.

  First, shape data of a three-dimensional model is read from the user interface 200 or the data storage unit 301 into the cross-section data generation unit 302. The shape data of the three-dimensional model is sliced at a predetermined interval in a plane perpendicular to the stacking direction by the cross-section data generation unit 302, and cross-section data for each slice cross-section is generated. Further, when modeling a three-dimensional model with a plurality of types of modeling materials, it is possible to generate cross-sectional data including material arrangement information by reading shape data and material type and position information into the cross-section data generation unit 302. it can.

  The load calculation unit 303 acquires the cross-sectional shape data generated by the cross-section data generation unit 302 and calculates a load to be applied at the time of stacking.

  If the pressure applied to the material layer at the time of lamination is too large, the resulting three-dimensional object will be deformed with respect to the target shape, and if it is too small, there will be a portion where the material layers cannot be joined due to insufficient pressure. Therefore, in the present invention, the load at the time of stacking is calculated according to a conditional expression that considers stable stacking of material layers. A conditional expression for calculating a load for realizing stable lamination will be described in detail later.

  After calculating the load applied at the time of stacking, the support shape calculation unit 304 calculates the shape of the support body. The support body supports the structure body at the time of modeling, and is generally provided under a portion (overhang portion) projecting in a bowl shape of the structure body. By providing the support body, it is possible to stabilize the lamination of the overhang portion or to secure the strength of the three-dimensional object during the modeling. However, the support body does not necessarily have to be placed below the overhang, and depending on the material of the structural material, the shape of the three-dimensional object, and the modeling method, modeling may be possible without providing a support body. is there. The support body becomes unnecessary and is removed when the shaping is completed.

  In the present invention, the support body can be provided in a portion that is easily deformed other than the overhang portion. Since the structure and arrangement of the support body required depending on the area of the material layer to be laminated and the load value applied at the time of lamination are different, data is exchanged between the load calculation unit 303 and the support shape calculation unit 304, A load suitable for modeling and the shape of the support body are calculated.

  In the present invention, the material constituting the support body is referred to as a support material, the material constituting the three-dimensional model is referred to as a structural material, and when it is not necessary to distinguish the two, the support material and the structural material are collectively referred to as a modeling material. As the support material, it is preferable to use a material having a high solubility in a solvent in which the structural material does not dissolve in order to facilitate removal after the completion of modeling.

  In the case of modeling that requires a support body, lamination is performed according to slice data obtained by adding the cross-sectional shape data of the support body to the cross-sectional shape data of the three-dimensional model generated by the cross-section data generation unit 302. The slice data generated by the parameter setting unit 300 and the determined load are sent to the control unit 400.

  The material layer formation control part 401 of the control part 400 controls the material layer formation part 20 based on the acquired slice data, and forms a material layer in an electrophotographic process. A latent image for each material type of slice data is drawn on the photosensitive roller 3 of each of the modeling material supply units 1A to 1D arranged in the material layer forming unit 20. For example, when the slice data includes the data of the modeling material accommodated in each of the modeling material supply units 1A and 1B, the latent image according to the data of each material type is provided on each photosensitive roller 3 of the modeling material supply units 1A and 1B. Is drawn.

  The photoconductor roller 3 is supplied with the modeling material accommodated in the modeling material supply unit, and an image made of each modeling material is formed. An image made of a modeling material formed on the photosensitive roller 3 of each modeling material supply unit is transferred to the first carrier 4 and becomes a material layer 5. The material layer 5 corresponds to a material for one layer stacked to form a three-dimensional object.

  The material layer 6 sent to the secondary transfer portion by the first carrier 4 is transferred from the first carrier 4 to the second carrier by an electric field applied between the second carrier 8 and the first carrier 4. 8 is transferred onto.

  The material layer 7 transported to the tertiary transfer portion by the rotation of the second transport body 8 is transferred to the third carrier 15 by the applied electric field in the same manner as the secondary transfer portion. In FIG. 1, belt-like members are used for the first carrier 4 and the third carrier 15, but the invention is not limited to this, and other forms such as a cylindrical drum may be used. In addition, a configuration in which the second carrier and the third carrier are omitted and the first carrier is directly laminated may be used.

  The material layer is heated by the heater 9 provided in the middle of being conveyed to the stacking position by the third carrier and melts into a sheet shape. However, heating in the middle or forming the material layer into a sheet may be performed as necessary, and is not an essential process. The sheet-like material layer is conveyed to the stacking position and stacked on the stage 14 or a three-dimensional object on the stage 14. The stage 14 and the temperature control member 13 are provided to face each other in parallel with the third carrier 15 interposed therebetween, and can move in the vertical direction. With such a structure, it is possible to change the relative distance between each other and apply an arbitrary load to the three-dimensional object and the material layer sandwiched between the two. The stacking position here is a region sandwiched between the stage 14 and the temperature control member 13.

  A load sensor or a pressure sensor is attached to the temperature control member 13 so that the load on the three-dimensional object 11 and the material layer 12 can be measured. When the load (pressure) sensor 19 exceeds the load value calculated by the parameter setting unit 300 during pressurization, the pressurization is controlled to be suppressed, and the deformation of the three-dimensional object can be suppressed.

  The pressed sheet-like material layer 12 is in close contact with the upper surface of the three-dimensional object 11 being modeled, heated and melted by the temperature control member 13 via the third transport body 15, and then cooled and solidified. It joins from the conveyance body 15 to the three-dimensional object 11 under modeling. Thus, the process of laminating the material layer on the three-dimensional object 11 being modeled is repeated, and the three-dimensional object is modeled.

  Hereinafter, as an embodiment, a specific flow for calculating a load that realizes stable lamination will be described.

(First embodiment)
In this embodiment, the load applied when stacking is made smaller than the maximum load calculated by the load calculation unit 303, thereby preventing an excessive load from being applied to the three-dimensional object and realizing good stacking. It is.

FIG. 3 shows a specific flowchart in the parameter setting unit 300 for calculating the load F (h) applied when the height h is stacked. After starting the calculation in S501, first, in S502, the shape data of the three-dimensional model, the arrangement information (modeling object shape) of the modeling material, and the physical property values of each modeling material are acquired. Here, the physical property values refer to the compressive yield strength and Young's modulus of the structure composed of the structural material and the support body composed of the support material. Hereinafter, the compressive yield strength and Young's modulus of the structure are represented as σ _str and E _str , respectively, and the compressive yield strength and Young's modulus of the support body are represented as σ _sup and E _sup , respectively. Here, h represents the height of the three-dimensional object in the middle of modeling, and 0 <h <H where H is the height of the three-dimensional object when modeling is completed. Further, the load applied when the stacking is completed up to the height h and the next layer is stacked is defined as F (h).

Subsequently, an initial support body shape is determined in S503. The initial support body shape here corresponds to the shape of the support body calculated from the shape data of the three-dimensional model, such as an overhang portion. In S504, the user sets an arbitrary load value F ₀ (h).

In S505, based on the support body shape information determined in S503 and the modeled object information, the maximum load F _max (h) that does not cause plastic deformation when the lamination is continued is calculated. Details of the derivation of the maximum load F _max (h) will be described later. The cross sections of the structure and the support body at the height h are S _str (h) and S _sup (h), respectively, and the maximum load F _max is (1 ).

F _max (h) = min {S _str (z) · E _str + S _sup (z) · E _sup | 0 <z <h}
Min ([sigma] _str / _Estr , [sigma] _sup / _Esup ) (1)
In S506, it is checked whether F ₀ (h) <F _max (h) is satisfied for each h in the range of 0 <h <H. If the condition is not satisfied, F ₀ (h) is changed to a value satisfying F ₀ (h) <F _max (h) in S507, and then the process proceeds to S508. If F ₀ (h) <F _max (h) is satisfied, the process proceeds to S508 without changing F ₀ (h). In S508, F ₀ (h) is set as the final load F (h). In S509, lamination is started at the load value F (h) determined in S508.

Next, the concept of deriving the maximum load F _max (h) will be described.
(When the model is composed of a single material)
[A. Solid object with uniform cross-sectional area and shape in the Z direction of the 3D model]
First, let us consider a case where a three-dimensional object made of a single structural material having a uniform area and shape of a slice cross section in the Z direction of a three-dimensional model is pressed. This corresponds to additive manufacturing without using a support material.

  The Young's modulus of the material constituting the three-dimensional object is E, the length (height) in the Z direction is l, and the cross-sectional area of the three-dimensional object at the height l is S. In general, since a material is compressed when pressed, when a load F is pressed along the Z-axis during lamination, the three-dimensional object is shortened from l to (l−Δl) by Δl. The strain ε generated at this time is expressed as ε = (Δl / l). According to material mechanics, pressure σ = ε · E is applied to the cross section of the three-dimensional object. Therefore, it can be expressed as force F = σ · S = ε · E · S.

The pressure σ and the deformation amount Δl are in a proportional relationship, and when the load is removed, the three-dimensional object returns to its original size. This is called elastic deformation. However, if σ is too large, even if the load is removed, deformation remains and plastic deformation occurs. It is known that σ at the time of plastic deformation from this elastic deformation takes a value specific to the material. This σ is referred to herein as compressive yield strength, and that of the structural material is expressed as σ _str . Here, when a pressure _{equal to} or higher than σ _str is applied to the structural material, the three-dimensional object is plastically deformed, and the laminated surface is inclined or the shape of the laminated cross section is changed. From the above, the maximum value of the force (load) that can be applied to the three-dimensional object is F = σ _str · S = ε · E · S = (σ _str / E) · E · S
It becomes.

[B. Solid object whose area and shape of the slice cross section of the 3D model are not constant in the Z direction]
Next, consider a case where the cross-sectional area obtained by slicing the three-dimensional model in the Z direction is not constant. Assume that the area of the slice cross section is expressed as S (h) as a function of the height h from the stacking stage. When a load F is applied in the Z direction, the same load F (h) = σ (h) S (h) is applied to all laminated sections. Here, σ (h) is a pressure in a section having a height h. The highest pressure σ (z) is applied to the layer having the smallest cross-sectional area S (z) in the range of height 0 <z <h. However, regarding the laminated cross section, one layer and one layer, the area and shape of the slice cross section can be considered in the same manner as a three-dimensional object that is uniform in the Z direction. Therefore A. The same argument can be applied, and the lamination pressure σ should satisfy σ <σ _str so as not to cause plastic deformation in the laminate. Therefore, when considering only a laminated section having a height h from the stage, the upper limit value of the load F (h) that can be applied to the section is F _max (h) = σ _str · S (h) = (σ _str / E) ・ E ・ S (h)
It becomes.

From the above, when considering the entire three-dimensional object, the upper limit value of the load F that can be applied is the minimum value of F _max (z) (0 <z <h). Min {F (z) | 0 <z <h} = (Σ _str / E) · min {E · S (z) | 0 <z <h}
It becomes.

(When the model is composed of multiple materials)
Next, consider the case of modeling a three-dimensional object composed of two types of modeling materials, a structural material and a support material. A. Similarly, it is assumed that the solid object has a uniform area and shape of the slice cross section in the Z direction.

When the load F is applied, both the structure and the support body are compressed. At this time, it is assumed that the stacking height in the Z direction is l and the compression distance is equal to Δl for both materials. The Young's modulus of the structure is E _str , the compression yield strength is σ _str , and the cross-sectional area is S _str . Similarly, the Young's modulus of the support body is E _sup , the compression yield strength is σ _sup , and the cross-sectional area is S _sup . The strain ε _str in the structure and the strain ε _sup in the support body are equal to ε because the deformation amount Δl is equal.

Then, the pressure σ _str = ε _str · E _str is applied to the cross section of the structure and the pressure σ _sup = ε _sup · E _sup is applied to the cross section of the support body by the same discussion as described above. Therefore, the load F is F = σ _str · S _str + σ _sup · S _sup = ε · (E _str · S _str + E _sup · S _sup )
It can be expressed as.

The upper limit value of F requires that the structural body and the support body do not undergo plastic deformation when receiving the force. Since the strain can be expressed by ε = σ / E, ε may be set to the upper limit of σ _str / E _str and σ _sup / E _sup whichever is smaller. From the above, the maximum value F _max of the load F is F _max = min (σ _str / E _str , σ _sup / E _sup ) · (E _str · S _str + E _sup · S _sup )
It can be expressed as.

Next, let us consider a case in which two types of materials, a structural material and a support material, are used, and the cross-sectional area and cross-sectional shape of each layer change in the Z direction. In this case as well, if it is considered that there is no difference in the strain ε between the structure and the support body during pressurization, the discussion when the cross-sectional shape changes in the Z direction can be applied when only the structural material is used. The load F (h) applied to the stacking surface with the height h from can be expressed as follows.
F (h) = ε · {E _str · S _str (h) + E _sup · S _sup (h)}

Since the upper limit of ε should be the smaller of the upper limits of the compressive strength of the structural material and the support material, it is expressed by the following equation.
max (ε) = min (ε _str , ε _sup ) = min (σ _str / E _str , σ _sup / E _sup )

The upper limit value of the stacking load F that can be applied without causing plastic deformation is the minimum value of F (z) (0 <z <h). Therefore, the upper limit F _max (h) that F (h) can take is
F _max (h) = min {F (z) | 0 <z <h}
= Min {ε · (E _str · S _str (h) + E _sup · S _sup (h)) | 0 <z <h}
= Min {S _str (z) · E _str + S _sup (z) · E _sup | 0 <z <h}
・ Min (σ _str / E _str , σ _sup / E _sup )
Thus, equation (1) is derived.

As described above, if F (h) is determined so as to satisfy F (h) <F _max (h) according to the equation (1), the three-dimensional object is not deformed due to overload at the time of lamination. It can be carried out.

(Second Embodiment)
In the first embodiment, the upper limit of the load for performing stacking without causing deformation has been described. In the present embodiment, the lower limit of the load when the optimum stacking pressure (the pressure necessary to sufficiently bond the layers) between the structural material and the support material is known will be described. According to the present embodiment, an optimum load can be applied to the composite laminate of the structural material and the support material, and a high-strength shaped article is realized.

FIG. 4 shows a specific flowchart in the stacking parameter setting unit 300, particularly the load calculation unit 303, for calculating the load F (h) applied when stacking the height h. After starting in S601, a shaped object shape and physical property values are acquired from the data storage unit 301 in S602. Here, the physical property values represent Young's moduli E _str and E _sup of a structural material or a support material, and minimum pressures P _str and P _sup required for joining layers made of single materials. In step S603, the initial support material shape is determined. As in the first embodiment, this corresponds to the shape of the support body calculated from the shape data of the three-dimensional model, such as an overhang portion. In subsequent S604, the user determines F ₀ (h) (0 <h <H) of an arbitrary initial load.

In S605, the minimum stacking load F _min (h) for the composite laminate of the structural material and the support material is calculated based on the support material shape information and the modeled object information acquired in S603. Specifically, the load applied at the time of lamination is preferably set to a value equal to or greater than F _min (h) expressed by the equation (2). Details of the derivation of equation (2) will be described later.
F _min (h) = {S _str (h) · E _str + S _sup (h) · E _sup }
Max (P _str / E _str , P _sup / E _sup ) (2)

Here, the cross-sectional area, Young's modulus, and minimum lamination pressure of the structure are S _str (h), E _str , P _str , respectively, and the cross-sectional area, Young's modulus, and minimum lamination pressure of the support body are S _sup (h), E _sup and P _sup .

In S606, it is checked whether F _min (h) ≦ F ₀ (h) is satisfied for each h. If Expression (2) is not satisfied, F ₀ (h) is changed to a value satisfying Expression (2) in S607 and the process proceeds to S608. If satisfied, F ₀ (h) is not changed. The process proceeds to S608. In S608, the corrected F ₀ (h) is determined as the value of the final load F (h). In S609, lamination is started according to the load determined in S608.

  Next, the derivation of Expression (2) will be described in detail.

For each of the structural material and the support material, a pressure necessary to sufficiently bond the layers is acquired. When laminating by applying a load under a certain temperature, if the load is too small, the outermost surface layer of the surface to be laminated and the surface polymer on the layer side to be laminated are not compatible with each other, Sufficient lamination strength cannot be maintained. For this reason, there is generally a minimum lamination pressure (minimum load) necessary for joining both the structural material and the support material, which are denoted as P _str and P _sup , respectively.

Assuming that the structure body and the support body have the same strain amount ε by the same discussion as in the first embodiment, the applied stacking load F (h) can be expressed as follows.
F (h) = ε {E _str · S _str (h) + E _sup · S _sup (h)}

When the lamination pressure σ is lower than either P _str or P _sup , the pressure required for joining either the laminated material or the support material is not reached, and the structure strength or the strength of the support body is reduced. A stable stacking operation cannot be performed. Therefore, the stacking pressure σ needs to be _{equal to} or higher than P _str and P _sup so that both the structural material and the support material can be bonded.

Here, P _str / E _str = ε _str , P _sup / E _sup = ε _sup . If a strain greater than the larger value of ε _str and ε _sup occurs due to pressurization, the stacking pressure σ will be greater than or equal to P _str and P _{sup in} both the structure and the support body. It can be performed. Therefore, the minimum value that can be taken by the strain ε within a range where a good stacking can be realized is ε = max (P _str / E _str , P _sup / E _sup ), and a preferable range of the load F (h) is expressed by the equation (2) F It is in the range of _min (h) or more.

As described above, according to this embodiment, a composite laminate composed of a structural material and a support material can be laminated with sufficient strength by applying a force equal to or greater than the value determined as the minimum load. However, if the upper limit of the first embodiment is exceeded, deformation of the shaped object occurs, and therefore F (h) needs to be a value smaller than F _max (h) expressed by the expression (1). That is,
F _min (h) ≦ F (h) <F _max (h) (3)
By applying the load F (h) in a range that satisfies the above conditions, it is possible to obtain a shaped article with high strength and suppressed deformation.

(Third embodiment)
Depending on the shape of the three-dimensional model, it may not be possible to set F (h) that simultaneously satisfies the expression (3) in modeling with the initial support body shape added. Therefore, in the present embodiment, by changing the shape (lamination cross-sectional area) of the initial support body, F (h) that satisfies the relational expression (3) is set, and good lamination is realized.

FIG. 5 shows a specific flowchart in the load calculation unit 303 for calculating F (h). After starting in S701, a shaped object shape and physical property values are acquired from the data storage unit 301 in S702. Here, the physical property values refer to the compressive yield strength, optimum laminating pressure, and Young's modulus of the structure and the support body. The compressive yield strength, optimum laminating pressure and Young's modulus of the structure are respectively represented by σ _str , P _str , E _str , and the compressive yield strength, optimum laminating pressure and Young's modulus of the support body are respectively represented by σ _sup , P _sup , E _sup and Represent. Next, an initial support body shape is determined in S703. As in the first embodiment, this corresponds to the shape of the support body calculated from the shape data of the three-dimensional model, such as an overhang portion. In S704, the user sets an arbitrary initial load F ₀ (h). In S705, based on the initial support body shape information and the three-dimensional model information acquired in S703, the initial load value of F (h) is calculated as the minimum load calculated by Expression (2). Check whether the above condition is satisfied. If you do not meet the conditions, change the value of _F 0 (h) so as to satisfy the condition in S706, if the condition is satisfied the process proceeds to S707 without changing the _F 0 (h). In S707, it is checked whether or not the load value determined in S704 or S706 satisfies a condition that is smaller than the maximum load calculated by Expression (1). When the condition smaller than the maximum load is satisfied, in S710, the load F (h) checked in S705 is set as a load to be applied at the time of stacking. If there is no value that satisfies the condition smaller than the maximum load, the shape of the support body is changed in S708, and the process proceeds to S709. In S709, the maximum load F _max (h) and the minimum load F _min (h) are calculated using the changed support body shape, and the process proceeds to S705 again. The support body shape is changed until a load satisfying a condition smaller than the maximum load calculated by Expression (1) can be set, and the final load F (h) and the support body shape (that is, S _sup (h)) are obtained. In step S711, stacking is started. If the stacking operation is completed in S712, the process ends in S713.

  As an example of the shape of the three-dimensional model in which the present embodiment is particularly effective, as shown in FIG. 6A, there is a shape having a portion with a small cross-sectional area from the upper part to the lower part in the stacking direction. FIG. 6A shows the shape of the three-dimensional model 800 viewed from the X direction.

  In the modeling of the three-dimensional model 800 in FIG. 6A, when the layer of the cross section c is stacked, if the stack is performed with a load equal to or greater than the minimum load calculated from the equation (2), the pressure is directly below the section c. Since the concentrated load is applied to the cross section d, the equation (1) cannot be satisfied. That is, in the case of the three-dimensional model shown in FIG. 6A, a load that satisfies Equation (3) cannot be set. Therefore, a deformation | transformation will generate | occur | produce in some site | parts of a molded article.

Therefore, in the present embodiment, in addition to the support body 811 based on S703, a support body 812 based on S708 is added in the vicinity of the portion d having a small cross-sectional area of the three-dimensional model 800 shown in FIG. By such processing, the cross-sectional area ΔS _{sup of} the support body portion 812 added to the cross-sectional area S _sup of the support body portion 811 becomes the support body at the time of modeling the three-dimensional model, and the area thereof is (S _sup + ΔS _sup ). Can be increased.

FIG. 6B shows a cross section of the cross section d viewed from the Z direction. When the cross-sectional area of the support material in the region of the height z (0 <z <h) is changed from _{S sup} (z) in _{S sup (z) + ΔS sup} (z), F max (h) increases. Since the shape of the support body is changed, the value of F _min (h) also changes. Therefore, the value of F _min (h) is recalculated in S709. In this way, it is possible to set a load F (h) that satisfies Equation (3).

  When the modeling method according to the present embodiment is used, it is possible to perform stable modeling while suppressing a lack of load and deformation of a modeled object due to overload.

(Fourth embodiment)
In the third embodiment, a method of adding a reinforcing support body only to a portion where deformation occurs when F (h) that simultaneously satisfies the expression (3) cannot be set in modeling with an initial support body shape added. explained. This embodiment demonstrates the case where the support body for reinforcement is added to the whole.

  This embodiment will be described with reference to FIG. FIG. 7A is a diagram illustrating the shape (sphere) of the three-dimensional model 901 represented by the three-dimensional shape data together with the XYZ axes. In the present embodiment, a plurality of layers formed according to slice data generated based on cross-sectional data parallel to the XY plane of the three-dimensional model are stacked in the Z-axis direction.

FIG. 7B shows a structure 902 that is shaped according to the slice data and an initial support 903 that is determined according to the setting by the user. The initial support body 903 is performed according to the flow of FIG. 5 as in the third embodiment, and is calculated in S703. Subsequently, in S704, the user sets an arbitrary initial load F ₀ (h). In S705, based on the initial support body shape information and the three-dimensional model information acquired in S703, the initial load value of F (h) is calculated as the minimum load calculated by Expression (2). Check if the condition is greater than If the condition is not satisfied, the value of F ₀ (h) is changed so as to satisfy the condition in S706, and if the condition is satisfied, the process proceeds to S707 as F (h) = F ₀ (h). In S707, it is checked whether or not the load value determined in S704 or S706 satisfies a condition that is smaller than the maximum load calculated by Expression (1). When the condition smaller than the maximum load is satisfied, the process proceeds to S710, and F (h) sent to S705 is set as the applied load at the time of lamination. If there is no value that satisfies the condition smaller than the maximum load, the process proceeds to S708, and the shape of the support body is changed to satisfy the condition, and the process proceeds to S709. At this time, in the present embodiment, as shown in FIG. 7C, the shape of the support body 904 is changed so that the cross-sectional area of the shaped object composed of the structure body 902 and the support body 904 becomes a constant value. .

  The shape of the support body 904 obtained by slicing the cross-section obtained by slicing the modeled object at an arbitrary position in the stacking direction always matches, and the cross-section sliced at an arbitrary position in the stacking direction of the structure 902 is projected onto the stage. It may be provided so as to include the shape. Specifically, as shown in FIG. 6C, a cylinder in which the cross section of the modeled object coincides with the maximum cross section of the structure 902 may be used. Alternatively, a polyhedron such as a cube or a polygonal cylinder covering the entire structure 902 may be used.

When the shape of the support body 904 is changed in S708, the process proceeds to S709, and the maximum load F _max (h) and the minimum load F _min (h) are calculated using the changed support body shape, and the process returns to S705. Proceed. If the support body changed in S708 is used, a load that satisfies a condition smaller than the maximum load calculated in Expression (1) can be set reliably, and therefore, the process can proceed to S710 after S705. In S710, lamination is started using the changed support body shape and the final load F (h) set in S710. If the stacking operation is completed in S711, the process ends in S712.

  According to this embodiment, by arranging the support material so that the area of the slice becomes a constant value, the load applied at the time of stacking can be made constant regardless of the height. Can be maintained.

13 Temperature Control Member 14 Stage 19 Pressure Sensor 20 Material Layer Forming Unit 100 Modeling Unit 200 User Interface 300 Parameter Setting Unit 301 Data Storage Unit 302 Cross Section Data Generation Unit 303 Load Calculation Unit,
304 Support shape calculation unit 400 Control unit

Claims (7)

A material in which a structural material constituting the three-dimensional model and a support material constituting a support body for supporting modeling of the structure are arranged based on slice data generated from shape data of the three-dimensional model A modeling method for manufacturing a model by sequentially stacking layers on a stage,
A modeling method, comprising: laminating the material layer on a model manufactured on the stage while applying a load smaller than a load causing deformation of the model manufactured on the stage. When modeling is completed, the height of the model is H, the Young's modulus and compressive yield strength of the structural material are E _str and σ _str , respectively, and the Young's modulus and compressive yield strength of the support material are E _sup and σ _sup , respectively. ,
When the area occupied by each of the structural material and the support material of the material layer laminated at a height z from the stage is S _str (z) and S _sup (z),
A load that causes deformation of the molded article at a position of height h (0 <z <h <H) from the stage,
F _max (h) = min {S _str (z) · E _str + S _sup (z) · E _sup | 0 <z <h} (1)
・ Min (σ _str / E _str , σ _sup / E _sup )
The modeling method according to claim 1, wherein   The modeling method according to claim 1 or 2, wherein a value of a load applied at the time of stacking the material layers is set to be equal to or greater than a load capable of joining the structural material and the support material. P _str and P _sup are the minimum pressure required for joining the layers made of a single material of each of the structural material and the support material, and the load that allows the structural material and the support material to be joined together.
F _min (h) = {S _str (h) · E _str + S _sup (h) · E _sup }
Max (P _str / E _str , P _sup / E _sup ) (2)
The modeling method according to claim 3, wherein: F (h) is a load at a height h (0 <h <H) from the stage,
F _min (h) ≦ F (h) <F _max (h)
The shaping method according to claim 4, wherein the shape of the support body is changed until F (h) that satisfies the condition can be set.   The modeling method according to claim 5, wherein the changed shape of the support body is a shape in which a cross-sectional shape and a cross-sectional area of the modeled object are constant.   The modeling method according to claim 1, wherein when the material layers are stacked, heat is applied simultaneously with applying a load.

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