JPH068342A - Production of shaped article having three-dimensional shape - Google Patents

Abstract

PURPOSE:To enhance planning efficiency by easily and rapidly judging the necessity of a reinforcing support part by judging whether the reinforcing support part is required in an upper photo-setting layer from the planar shapes of two photo-setting layers to be laminated up and down and planning the arrangement shape of the reinforcing support part. CONSTITUTION:An irradiation area irradiating a photo-setting resin with light or a laser beam scanning pattern is determined on the basis of the planning of a shaped article 10, a peripheral wall 30 and a reinforcing support part 43a and, based thereon, an actual molding process is performed. When the shaped article 10 is formed, the final curing process of the shaped article 10 is performed and, thereafter, the reinforcing support part 43a is cut off to obtain the shaped article 10 having an objective three-dimensional shape. Since the planning of the reinforcing support part can be performed by objectively judging the planar shapes of two photo-setting layers on the basis of a definite judging standard, proper planning becomes possible without being affected by the technique or skill of a worker.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a three-dimensional shaped object, and more specifically, it is used to mold and produce an article having a three-dimensional shape by using a photocurable resin which is cured by irradiation with light. It is about how to do it.

[0002]

2. Description of the Related Art A method for producing a three-dimensional shaped object using a photocurable resin is to form a complicated three-dimensional shape easily and accurately without using a molding die or a special processing tool. As a method that can be used, it is considered to use it for manufacturing various product models and three-dimensional models. Specifically, for example, JP-A-61-1114817, JP-A-63-141724, and JP-A-60-247515.
There is a method disclosed in Japanese Patent Publication.

According to the method disclosed in Japanese Patent Laid-Open No. 63-141724, a vertically movable molding table submerged in a resin liquid is arranged immediately below the liquid surface of the resin liquid, and the liquid surface is irradiated with a laser beam for molding. The resin liquid layer on the table is photo-cured to form a photo-cured layer, and then the molding table is slightly submerged, and then the same steps as above are repeated to form a plurality of photo-cured layers. Stack up. Other methods also differ in the detailed steps, but photo-curing a photo-curable resin to form a photo-curable layer,
It is common in that the photocured layers are stacked to obtain a three-dimensional shaped object.

In such a method for producing a three-dimensional shaped object, if the three-dimensional shape has substantially the same area from bottom to top or has a pyramid shape that decreases from bottom to top, The photo-curable layers sequentially formed from the bottom to the top can be stably supported by the photo-curable layers below. However, if a part of the three-dimensional shape has an eaves portion that protrudes more to the side than the lower part, or if there is a hanging part that is not supported at all, the eaves part and the hanging part are not supported. There is a problem in that the support of the photocurable layer constituting the film becomes insufficient and the photocurable layer is deformed or moved, resulting in the shape of the three-dimensional shape being broken or the shape accuracy being deteriorated.

In order to solve such a problem, it has been considered to provide a supporting portion for reinforcement, which is connected to a molded article and is formed by photocuring a photocurable resin similarly to the molded article. Specifically, there are methods disclosed in JP-A-2-22035 and JP-A-2-52725. In these methods, in the part that needs reinforcement among the shaped objects,
Connect one end of the arm or columnar reinforcement support, and connect the other end of the reinforcement support to a highly rigid support structure such as the bottom surface or wall of the resin liquid tank, or a part of the shaped object that is difficult to deform. By so setting, it is possible to prevent the deformation of the portion requiring reinforcement. In addition, if all the photo-cured layers forming the modeled product are formed and then the entire modeled product is completely photo-cured by heat treatment or the like, the modeled product is deformed without the reinforcing support portion. Since it does not occur, the reinforcing support portion may be removed by cutting or breaking.

FIG. 17 and FIG. 18 show a specific example of a case where a reinforcing support portion is provided on a modeled object having an eaves portion and a hanging portion. In FIG. 17, an eaves portion h that largely protrudes laterally is present at the upper end of the modeled article M that is generally U-shaped. Since the eaves portion h is only supported by the main body portion of the molded article M at one end thereof, when the photocurable resin is subjected to the contracting force when the photocurable resin is photocured or the fluid pressure of the resin liquid, the eaves portion h is warped upward. It causes deformation. Therefore, the eaves portion h is prevented from being deformed by connecting the eaves portion h and the stable bottom surface portion of the molded article M by the vertical reinforcing support portion S.

In FIG. 18 (b), a part of the molded article M has a downwardly projecting hanging portion t. As shown in FIG. 18 (a), when a large number of photocurable layers m are stacked in order from the bottom to form a modeled article M having the hanging portion t, one photocurable layer m is photocurable. A region independent of the surroundings in the resin, that is, a floating island portion f is formed. Since the floating island portion f is not supported anywhere at the time of being formed, the floating island portion f moves in the photocurable resin, and the shape accuracy of the molded article M is impaired. Therefore, as shown in FIG. 18 (b), if the reinforcing support portion S connecting from the fixed surface of the molded article M to the floating island portion f is provided, the floating island portion f does not have to move.

Since the formation position and the shape of the reinforcing support portion S as described above need to be changed depending on the overall shape of the molded article M and the positional structure of the eaves portion h and the floating island portion f, the molded article M has been conventionally used. After designing the entire shape, the operator empirically estimated the necessary portion of the reinforcing support portion S and designed the arrangement shape of the reinforcing support portion S and the like. In the method of molding a three-dimensional shaped object using a photocurable resin, the shape of the object M is converted into electronic information using a CAD device or the like, and based on this electronic information, for example, laser light is used. It is common to automatically form the photo-curable layer by controlling the scanning path of. Therefore, the design of the above-mentioned reinforcing support portion S has also been performed using the CAD device or the like.

[0009]

However, in the conventional method for molding a three-dimensional shaped object as described above, it is technically difficult to design the reinforcing support portion, and it takes a lot of time and labor for the whole production. It was a factor that hindered sex. This is because conventionally, when designing the reinforcing support part, the operator designs the reinforcing support part at an appropriate position of the molded article M while looking at the display screen of the CAD device.
The skill or skill of the operator is required, and it takes a lot of time and effort to design the reinforcement support part. Depending on the worker, the reinforcement support part may not be arranged at the place where the reinforcement is necessary, or the reinforcement may not be necessary. However, there was a case where an unnecessary reinforcing support portion was arranged. If there is no reinforcement supporting portion where reinforcement is required, the deformation of the molded article cannot be prevented at all. In addition, if the number of reinforcing support portions increases or the structure becomes complicated, it takes a long time to irradiate light for forming the reinforcing support portions, and thus the working time increases.
Useless reinforcement supports must be eliminated as much as possible.

In order to facilitate the design of the reinforcing support portion, as shown in FIG. 19, a support wall W surrounding the molded article M is formed by photocuring a photocurable resin, and this support wall is formed. It has been considered that a large number of lattice wall-shaped reinforcing support portions S are arranged at appropriate intervals from W to the outer shape of the model M. In this method, since the support wall W and the lattice wall-shaped reinforcing support portion S having a constant shape may be formed regardless of the shape of the modeled object M, the design is easy and the design time can be shortened. However, in this method, since the lattice wall-shaped reinforcing support portion S is arranged also in a portion of the molded article M that does not necessarily need to be reinforced, there is much waste of light irradiation and photocurable resin, Work efficiency deteriorates. Also, the model M
Since the number of connecting points between the reinforcing support portion S and the reinforcing support portion S is extremely large, it takes time and effort to remove the reinforcing support portion S from the molded article M after the molded article M is completed.

Therefore, an object of the present invention is to provide a method for appropriately and efficiently designing a reinforcing support portion for reinforcing a shaped article in the method for molding a three-dimensional shaped shaped article as described above. It is in.

[0012]

In the method for molding a three-dimensional shaped object according to the present invention, which solves the above-mentioned problems, the method of claim 1 is the method of irradiating a photocurable resin with light to form a photocurable layer. Reinforcement that connects a portion of the shaped article that needs to be reinforced and a support structure that supports the shaped article when manufacturing a shaped article having a desired three-dimensional shape by stacking a plurality of photocurable layers In the method of forming the support part by irradiating light on a photo-curable resin and photo-curing it, comparing the planar shapes of the two photo-curing layers stacked on top of each other, a reinforcing support part is required for the upper photo-curing layer. If it is determined that the reinforcing support portion is necessary, the light irradiation area corresponding to the reinforcing support portion is added to the light irradiation area for forming the upper photocurable layer. Set.

As the photo-curable resin, various photo-curable resins which are also used in the conventional method for molding a three-dimensional shaped object can be used. Specific examples include urethane, urethane-acrylate, epoxy, and epoxy-acrylate-based photocurable resins. The basic technique for molding a three-dimensional shaped object such as a method for supplying a photocurable resin, a method for irradiating light, a method for forming a photocurable layer, and a method for stacking photocurable layers is known in the art. Any ordinary method or device can be applied as it is.

The present invention is applied to a structure of a modeled object, at least a part of which has a part requiring reinforcement. The portion requiring reinforcement is the above-mentioned eaves portion, hanging portion, or the like. The portion requiring reinforcement is not limited to one location in one model, but may be present in multiple locations. The reinforcing support portion is formed by irradiating the photo-curable resin with light and photo-curing it by the same means as the formation of the photo-curable layer forming a three-dimensional shape. The reinforcing support portion is formed so as to connect a portion of the shaped article that requires reinforcement and a support structure that supports the portion. The support structure, for example, the surface of the molding table for molding the molded article, the inner wall surface of the resin liquid tank for storing the photocurable resin liquid, the pillars and walls erected around the molded portion of the molded article, Various fixing structures made of metal, synthetic resin, or the like may be used, or a structural part of the same modeled article that is highly rigid and difficult to deform due to its shape may be used as the support structure. Further, a photocurable resin may be photocured around the shaped article to form a peripheral wall or a column having sufficient rigidity, and the peripheral wall or the like may be used as a support structure.

As the shape of the reinforcing support part, the structure of various reinforcing support parts which have been used in the conventional method can be adopted, and in consideration of necessary strength and load direction, various shapes of arms or columns can be adopted. Eggplant can be used. As the reinforcing support portion, it is preferable to use a vertical column or a vertical wall shape as shown in FIGS. 15 to 17, or a horizontal arm extending in the horizontal direction. In the horizontal arm-like reinforcement support part, if the part of the modeled object that needs to be reinforced and the wall-shaped or columnar support structure arranged around the modeled object are connected horizontally, Since it can be connected to the support structure at a short distance, the structure of the reinforcing support part is simplified, and the function of preventing deformation of the modeled object is enhanced. Further, at the same time as the formation of the photocurable layer, it is possible to irradiate the photocurable resin with light on the same plane to form the reinforcing support portion, so that the reinforcing support portion can be easily formed. Regarding the specific structure of such a horizontal arm-shaped reinforcing support portion, Japanese Patent Application No. 1-18 previously filed by the inventors of the present application and filed a patent application
The structure disclosed in 6667 can also be utilized.

If a constricted portion that is narrower than other portions is provided at a portion of the reinforcing support portion that is connected to the molded article or a portion that is connected to the support structure, when the reinforcing support portion is finally removed, The waist can be easily broken or cut. In the present invention, the design of the reinforcing support portion as described above is not performed by judging from the shape of the entire modeled article, but two of the photocurable layers constituting the modeled article that are stacked one above the other are photocured. It is performed based on the result of comparing the plane shapes of the layers.

In order to mold the molded article, first, the planar shape of each of the plurality of photo-curing layers constituting the molded article is determined. The photo-curable layer is obtained by dividing the entire shape of the modeled object in the vertical direction at regular intervals so that each horizontal section has a planar shape and the vertical interval of the horizontal section has a thickness. Such a planar shape of each photo-curable layer is usually produced by converting the entire outer shape of the modeled object into electronic information by a CAD device or the like, and calculating the planar shape data of each photo-curable layer from this electronic information.

When the plane shape of each photocurable layer is determined, the light irradiation area for forming each photocurable layer is determined corresponding to this plane shape, and the information of the light irradiation area is used as information of the laser light. By inputting into a scanning control device or the like, a photo-cured layer having a required shape can be formed. Of the plurality of photo-curing layers, all the combinations of the two photo-curing layers that are stacked one above the other are taken out, and the planar shapes of the two photo-curing layers above and below are compared,
Determine whether a reinforced support is required for the upper photocured layer. Specifically, of the plurality of photo-curing layers, it is determined from the planar shapes of the bottom photo-curing layer and the second photo-curing layer whether or not the second photo-curing layer needs a reinforcing support portion. Then, it is determined from the planar shapes of the second photocurable layer and the third photocurable layer whether or not the reinforcing support portion is necessary for the third photocurable layer, and all the photocurable layers are cured. Determine the need for reinforcing supports for the layers.

The criterion for determining whether or not the reinforcing support portion is necessary is determined on the basis of whether or not the change in the planar shape of the upper and lower photo-curing layers affects the supporting state of the upper photo-curing layer. However, the specific criteria may be determined based on mechanical theory or experience. If it is determined that the reinforcing support portion is necessary, as a light irradiation area for forming the upper photocurable layer, in addition to the light irradiation area corresponding to the planar shape of the photocurable layer, as described above. An irradiation region of light corresponding to the reinforcing support portion having a structure is set. The light irradiation area set in this manner is converted into electronic information as described above, and if the scanning control of the laser light described above is performed according to this electronic information, the photocurable layer and the reinforcing support portion having a predetermined shape are formed. Can be continuously formed in the same process.

As a method of determining whether or not the reinforcing support portion is necessary, the methods of claims 2 and 3 can be adopted. The method of claim 2 remains in the plane shape data of the upper photocured layer when the area including the portion overlapping the plane shape data of the lower photocured layer is removed from the plane shape data of the upper photocured layer. If there is an isolated part, it is determined that the reinforcing support part connected to this isolated part is necessary.

The plane shape data usually means data obtained by converting the plane shape of the photo-curing layer into electronic information by the above-mentioned CAD device or the like, and comparing the plane shape data of the upper and lower photo-curing layers electronically. For example, it is easy to exclude the above-mentioned overlapping area. However, it is also possible to manually compare the planar shape data drawn on the paper, that is, the plan views.

If the lower photocurable layer is larger than or the same size as the upper photocurable layer, all areas are removed. If there is an isolated portion that remains in the planar shape data of the upper photocurable layer, this isolated portion has no contact with the lower photocurable layer and is not supported at all. That is, since the isolated portion is the floating island portion as described above, it is determined that the reinforcing support portion is necessary for the isolated portion.

According to a third aspect of the present invention, in the first or second aspect of the invention, respective contour line data is created from the planar shapes of the upper and lower photo-curing layers, and the same grid pattern is formed in each contour line data. When the intersection points with each contour line are obtained by overlapping with each other and the upper and lower contour line data are arranged at a predetermined interval, the line segment connecting the corresponding intersection points and the plane formed by the upper layer contour line data are formed. When the angle is equal to or smaller than the specified angle, it is determined that the reinforcing support portion connected to the intersection of the contour line data of the upper photocurable layer is necessary.

In this method, only the data of the contour line along the outer circumference is extracted from the planar shape data of the upper and lower photo-curing layers. If the planar shape data of the photo-curable layer is converted into electronic information, the contour line data can be easily created by the electronic information calculation process. The grid pattern may be arranged at a pitch such that the contour line data can be divided vertically and horizontally at appropriate intervals. The pitches of the vertical and horizontal grid lines forming the grid pattern are easier to process if they are at equal intervals, but they need not be at equal intervals. The finer the grid-like pattern, the more accurate the determination can be made, but the labor of the work increases. Therefore, the fineness of the grid-like pattern may be set so that the required accuracy or the reinforcing function can be obtained.

The intersection of the contour line data and the grid pattern is
The upper and lower contour line data are obtained respectively. The position of this intersection differs depending on the shape of the contour line data. Corresponding intersections in the upper and lower contour line data are the relationships between the intersections where the specific grid lines of the grid pattern intersect when the upper and lower contour line data are arranged vertically at the same intervals as the upper and lower photo-curing layers. Means Assuming a line segment connecting the upper and lower intersections, the angle between this line segment and the plane formed by the contour data of the upper layer is obtained. Specifically, when a perpendicular is drawn from an intersection on a specific grid line of the contour data of the upper layer, it reaches the corresponding grid line of the contour data of the lower layer. The desired intersection can be found by searching for the intersection along this grid line. However, there are cases where no intersection is found.

If the contour of the upper photocuring layer and the contour of the lower photocuring layer completely overlap, the corresponding upper and lower intersections will be present at the same position on the grid line, and the angle will be It becomes 90 degrees. If the contour of the upper photo-curing layer is smaller than the contour of the lower photo-curing layer, the intersection point on the upper side is located inside the contour line than the intersection point on the lower side on the grid line, and the angle is more than 90 °. growing. If the contour of the upper photo-curing layer is larger than the contour of the lower photo-curing layer, the intersection of the upper side is located outside the contour of the intersection of the lower side on the grid line, and the angle is more than 90 °. Get smaller. Therefore, as the angle becomes smaller, it means that the upper photo-curable layer projects more outward than the lower photo-curable layer.

If this angle is less than or equal to the specified angle, the overhang of the upper photocuring layer is large, and therefore it is determined that the upper photocuring layer needs a reinforcing support portion connected to the intersection. The specified angle varies depending on conditions such as the thickness of the photocurable layer, the material strength of the photocurable resin, and the required shape accuracy, but generally, for example, 35
It may be set to about °.

In some cases, the intersection of the contour data of the lower layer and the grid pattern corresponding to the intersection of the contour data of the upper layer and the grid pattern may not be found. In this case, the line segment cannot be set. Therefore, in this case, it may be determined that the angle is 0 °, the angle is equal to or less than the specified angle, and the reinforcing support portion is necessary, or in consideration of other determination criteria, A final determination may be made.

As described above, the preparation of the planar shape and contour line data of the upper and lower photo-curing layers, the setting of the grid pattern, the setting of the intersections and line segments, the calculation of the angle, etc. are performed by the CAD.
Based on the information about the outer shape of the model input to the device or the like, a computer can perform arithmetic processing to determine the necessity of the reinforcing support portion. In this case, the necessary arrangement and shape of the reinforcing support portion can be obtained only by inputting the entire shape of the modeled object into a CAD device or the like, and based on the result, the three-dimensional modeled object by irradiation of light is obtained. It is possible to automate the process up to molding.

[0030]

The reinforcing support portion is required for the molded article in the portion where the above-mentioned eaves portion and the hanging portion are present. In such a portion, the horizontal cross-sectional shape of the modeled object changes in the vertical direction. Since the modeled object is configured by stacking a plurality of photo-curable layers, if the horizontal cross-sectional shape of the modeled object changes, the planar shape of the photo-curable layers stacked vertically also changes.
Therefore, if the change in the cross-sectional shape in the vertical direction of the modeled object, that is, the change in the planar shape of the photo-curing layers stacked on top of each other is captured, it is possible to determine from the state of the change whether or not the reinforcing support portion is necessary for that portion. It is possible to judge.

When the reinforcing support portion is formed by photocuring a photocurable resin, a light irradiation area for forming the reinforcing support portion is additionally set in the light irradiation area for forming the photocurable layer. By doing so, the reinforcing support part can be formed in the same step as the formation of the photocurable layer, and the reinforcing support part can be efficiently formed. Therefore, the top and bottom two photo-curing layers are compared with each other in planar shape to determine whether or not the upper photo-curing layer needs the reinforcing support portion, and it is determined that the reinforcing support portion is necessary. If
By additionally setting the light irradiation area corresponding to the reinforcing support portion to the light irradiation area for forming the upper photocurable layer, the necessity of the reinforcing support portion can be easily determined, and the reinforcing support portion can be easily determined. Can also be efficiently formed.

In this method, the necessity of the reinforcing support portion is determined based on only the planar shapes of the pair of upper and lower photo-curing layers, not the entire three-dimensional shape of the modeled object. As a result, less information is needed to make a decision, and the decision can be made quickly. Moreover, as described above, in consideration of the necessity and function of the reinforcing support portion, even if only the planar shapes of the upper and lower photo-curing layers are used as the judgment material, a sufficiently accurate judgment can be made and it is necessary to prevent deformation of the shaped object. And it is possible to design a sufficient reinforcing support.

[0033]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the modeled article 10 has an eaves portion 12 that greatly protrudes laterally at the upper end of a rectangular parallelepiped main body portion, and a hanging portion 14 that protrudes downward in the middle of the eaves portion 12. is doing. The entire shape of the shaped article 10 is divided into five in the vertical direction, and five photocurable layers 21 to 26 are stacked to form the shaped article 10.
Make up. The horizontal cross-sectional shape at the positions Z _{1 to} Z ₆ in the height direction of the modeled object 10 is the planar shape of each photocurable layer 21 .... The eaves portion 12 is included in the upper two photo-curing layers 25 and 26, and the hanging portion 14 is included in the middle two photo-curing layers 23 and 24.

To mold the modeled article 10 having such a structure, first, the entire shape of the modeled article 10 is input to a CAD device or the like, and its graphic information is analyzed. FIG. 2 shows the modeled object 1.
The plane shape data of each of the photo-curable layers 21 to 26 forming 0 is shown. In the drawing, the lowermost photocurable layer 21 to the uppermost photocurable layer 26 are shown in order from the upper left end to the right end, and further from the lower left end to the right end. The two middle photocurable layers 23 and 24 are composed of main body portions 23a and 24a having the same shape as the photocurable layer 22 thereunder, and floating island portions 23b and 24b separated from the main body portions 23a and 24a. .

FIG. 3 shows, for each of the photo-curing layers 21 to 26,
The method of irradiating light such as laser light is shown. That is,
In the lowermost photo-curing layer 21, light is scanned in the vertical direction in the figure, and the scanning of the light in the vertical direction is shifted to the left and right,
The region corresponding to the entire photo-curable layer 21 is irradiated with light. In the next second photo-curing layer 22, in the drawing, light is scanned in the left-right direction, and the scanning of the light in the left-right direction is shifted vertically,
The region corresponding to the entire photo-curable layer 22 is irradiated with light. In the next third photo-curing layer 23, light is scanned again in the vertical direction. In this way, the scanning direction of light is changed to a direction orthogonal to each other for each layer. By doing so, each photocurable layer 21
When the photocurable resin is formed, the curing shrinkage stress generated when the photocurable resin is photocured is absorbed in the upper and lower stages, so that the molded article 10 is less likely to be distorted by the curing shrinkage stress.

FIG. 4 shows the lowermost photocurable layer 21.
The light irradiation area is described. In this lowermost layer, in addition to the photocurable layer 21 that constitutes the modeled object 10, a peripheral wall photocured layer 31 that surrounds the outside of the planar external shape of the modeled object 10 is formed.
That is, it is set so as to irradiate light annularly along the peripheral wall photo-curable layer 31. The photocurable layer for the peripheral wall is formed in exactly the same shape in the photocurable layers after the second layer. In this lowermost photocurable layer 21, since the photocurable layer does not exist under the photocurable layer 21, the reinforcing support portion is not necessary, and it is not necessary to determine whether or not the reinforcing support portion is necessary.

FIG. 5 shows the second photo-curing layer 22.
The light irradiation area is described. In addition, FIG. 6 illustrates a method of determining whether or not the reinforcing support portion is necessary for the second photocurable layer 22. The Z ₂ plane showing the planar shape of the photocurable layer 22 and the Z ₁ plane showing the planar shape of the photocurable layer 21 are separated by a distance D = Z ₂ −Z ₁ corresponding to the thickness of the photocurable layer 22. Since the Z ₁ surface and the Z ₂ surface have exactly the same shape,
If the area from the Z ₂ surface to the Z ₁ surface is deleted, no area remains. Therefore, according to this criterion, it is not necessary to provide the reinforcing support portion.

Next, a grid pattern 5 having grid lines X ₁ , X ₂ , Y ₁ , and Y ₂ on the Z ₁ plane at regular intervals in the vertical and horizontal directions.
Assume 0. Each grid line X ₂ of this grid pattern 50
.. and the contour line of the Z ₁ surface are indicated by a to h. On the Z ₂ plane, a grid pattern 60 obtained by vertically translating the grid pattern 50 is assumed. This grid pattern 6
The intersections of 0 and the contour line of the Z ₁ surface are indicated by a ′ to h ′. In the grid-like patterns 50 and 60, intersections a and a ', b and b', c and c ', d and d'arranged on the same grid line X ₁ on the same side as viewed from the center. , E and e ′, f and f ′, g and g ′, and h and h ′ respectively have corresponding intersections. The corresponding intersections a and a ′ are
Connect with line segment 70.

FIG. 7 shows the relationship between points on a vertical plane composed of intersections a and a'and intersections f and f'arranged on the same grid line Y ₂ . The angle θ ₁ formed by the Z ₂ plane and the line segment 70 connecting the intersection points a and a ′ is 90 °.
The angle θ ₂ between the Z ₂ plane and the line segment 70 connecting the intersection points f and f ′
Is also 90 °. Therefore, in this case, it is determined that the formation of the reinforcing support portion is unnecessary at any of the intersection points a and f.

Next, FIG. 8 illustrates the light irradiation area of the third photocurable layer 23. This photocurable layer 2
In No. 3, since it has the floating island portion 23b, the planar shape is different from that of the second photocurable layer 22. When the area of the portion overlapping the planar shape data of the photocurable layer 22 is removed from the planar shape data of the photocurable layer 23, only the floating island portion 23b remains.
Since the floating island portion 23b is an isolated portion apart from the main body portion 23a, it is determined that the floating island portion 23b needs a reinforcing support portion. Regarding the arrangement of the reinforcing support portion, first, the strip-shaped reinforcing support portion 43b is set from the outer periphery of the floating island portion 23b toward the nearest photocurable layer 33 for the peripheral wall. Even on the opposite side of the floating island portion 23b, the reinforcing support portion 4 faces the photocurable layer 33 for the peripheral wall.
3b is set. Considering the area of the floating island portion 23b and the like, if it can be determined that it can be supported only by the reinforcement supporting portion 43b, no further reinforcement is necessary. However, if the unidirectional reinforcing support portion 43b is not sufficient, the reinforcing support portion 43 is oriented toward the support structure closest to the floating island portion 23b, that is, the main body portion 23a in the direction orthogonal to the reinforcing support portion 43b.
Set a. Only one reinforcing support part 43a may be provided at the center of the floating island part 23b, but two reinforcing support parts 43 are provided on the left and right sides.
If a is provided, the support becomes more reliable.

In this case, it is possible to set the necessity of the reinforcing support portion and the layout shape thereof without performing the determination using the above-described upper and lower contour line data. However, in the case where the determination is made by the contour line data similar to the above, the photocurable layer 23
Since the main body portion 23a and the photo-curable layer 22 have exactly the same planar shape, the angle is 90 ° at all positions,
It is determined that the main body portion 23a does not need the reinforcing support portion. Further, when the floating island portion 23b is determined by the contour line data, the line segment 70 cannot be assumed because the photo-cured layer 22 has no portion corresponding to the floating island portion 23b. In this case, the angle θ formed by the line segment 70 and the photo-curable layer 23 can be regarded as 0 °, and it can be determined that the reinforcing support portion is necessary. That is, even in the determination using the contour line data, the reinforcing support portion 43 is similarly subjected.
It is determined that a and 43b are necessary.

Next, the fourth-layer photo-curing layer 24 has exactly the same planar shape as the third-layer photo-curing layer 23. Therefore, if the above-mentioned determination method is applied, the reinforcing support portion is not required. To be judged. However, when the strength and rigidity of the reinforcing support portions 43a and 43b provided on the photo-curable layer 23 are insufficient, the photo-curable layer 24 is overlaid with the reinforcing support portion at the same position as the photo-curable layer 23. It may be formed.

Next, FIG. 9 illustrates a light irradiation region of the fifth photo-curing layer 25. In addition, FIG.
Describes a method of determining whether or not a reinforcing support portion is necessary for the fifth photocurable layer 25. First, the photocurable layer 2
From the Z ₅ plane showing the planar shape of No. ₅ , except for the region of the portion overlapping with the Z ₄ plane showing the planar shape of the photo-curable layer 24, there is no region remaining on the Z ₅ plane. Therefore, it can be determined that the photocurable layer 25 does not have a portion corresponding to a floating island.

Comparing the planar shape area of the photo-curable layer 25 with the planar shape area of the photo-curable layer 24, the photo-curable layer 25 is considerably larger. Therefore, the photo-curable layer 25 has a reinforcing support portion. It can also be determined to be necessary. Next, the photocurable layer 25 and the photocurable layer 24 are compared with each other by the contour line data as described above. Each Z ₅ face and Z ₄ sides, grid lines X ₁ at the same spacing position, X _2, Y ₁ ~
If the lattice-shaped patterns 60 and 50 provided with Y ₅ are overlapped, the intersection points a to n are obtained on the Z ₅ plane and the intersection points a _{1 to} n ₁ are obtained on the Z ₄ plane, as described above. When a perpendicular is drawn from the intersection points a to n of the Z ₅ plane, at the intersection points d, f, g, h, i, k, the corresponding intersection points d ₁ , f ₁ , g ₁ , h ₁ , i ₁ , k ₁ are Since it is right underneath, no reinforcement support is needed in this part.
At the intersections b, c, e, j, l, and m, since there is no corresponding intersection, it is considered that the angle is 0 °, and it can be determined that a reinforcing support portion is also required at this portion.

At the intersection point a, the foot of the perpendicular is the grid line X ₁
The intersection is not found even if it is moved to the outside along. When moved inward, the intersection a'is found and the line segment 70 can be set. FIG. 11 shows a vertical section taken along the grid line X ₁ including the intersection point a. Here, the angle θ formed by the line segment 70 and the Z ₅ plane is considerably smaller than 90 °. Therefore, it is determined that a reinforcing support portion needs to be formed at this intersection a. Also for the intersection n, it is similarly determined that the reinforcing support portion is necessary.

As shown in FIG. 12, the fifth photocurable layer 2
5, a reinforcing support portion 45a is formed from the intersections a and n toward the outer peripheral photocurable layer 35. The intersection point b,
For c, e, j, l, m, the intersection point b,
A reinforcing support portion 45b is formed from e, j, m toward the outer peripheral photocurable layer 35, and no reinforcing support portion is formed at the intersection points c, l. This is because when the distance between the intersections requiring reinforcement is short, even if one of them is omitted, the photocurable layer 2
This is because the reinforcement support of No. 5 can be sufficiently performed.

Next, since the sixth photo-curing layer 26 has the same planar shape as the fifth photo-curing layer 25, it is determined that the reinforcing support portion is not necessary if the same criteria as described above are applied. To be done. However, also in this case, if it is considered that the strength of the reinforcing support portions 45a and 45b formed in the photo-curable layer 25 is insufficient, the reinforcing support portions may be formed in the same position in the photo-curable layer 26 as well.

FIG. 13 shows an arrangement structure of the reinforcing support portion designed as described above. A vertical peripheral wall 30 is arranged on the outer side of the modeled object 10. A portion of the shaped article 10 that needs to be reinforced, that is, between the hanging portion 14 and the eaves portion 12 and the peripheral wall 30, or the shaped article 1
0 and the main body portion of the reinforcing support portions 43a, 4 and
3b, 45a, 45b are arranged.

FIG. 15 and FIG. 16 collectively show a flow chart of the designing procedure of the reinforcing support portion as described above. First of all, in (1) “Calculation of contour surface contour data”, the three-dimensional shape of the modeled object is cut at a constant height in the vertical direction so that it can be formed by dividing it into multiple photo-cured layers. , Obtain the contour data of the horizontal section. This contour data represents the planar shape of each photocurable layer. A number i is attached to each contour data in order from the bottom.

(2) "Addition of peripheral wall data" is data representing the shape of the peripheral wall provided as the support structure of the reinforcing support portion, and a peripheral wall having a constant thickness can be formed in advance at a position surrounding the outer periphery of the modeled object. Make settings as you can. Normally, the peripheral wall data may be the same for all cross sections, but it may be set so that the lower part is thicker and the upper part is tapered downward.

In the steps (3) to (4), when it is determined that there is a floating island portion, (5) "data addition of reinforcing support portion" is performed.
Specifically, the reinforcing support portion is set so as to connect the contour data that has not been removed, that is, the isolated floating island portion, to the nearest portion of the removed contour data region. In this case, the floating island portion is supported by the reinforcing support portion on the main body portion of the modeled object. If there is not enough area to support the floating island portion, a reinforcing support portion that connects the floating island portion to the peripheral wall is set.

Next, in steps (6) to (10), if the angle obtained from the intersection of the upper and lower contour line data and the grid pattern by a predetermined procedure is less than the specified angle, (11) " Add data for reinforcement support section ". Also in this case, the reinforcing support part is set so as to be connected to the closest main body part or peripheral wall of the modeled object from the intersection point position where the reinforcing support part is required.

The above steps (2) to (11) are repeated from i = 1
It is repeated for each contour data up to the i = n plane, it is determined whether or not the reinforcement support portion data needs to be added for the contour data of all the cross sections, and the reinforcement support portion data of the necessary arrangement shape is added. The shape data of the photo-curable layer and the reinforcing support necessary for forming the molded article are completed. If the above-described flowchart is programmed in a computer or the like, it is possible to automatically design the necessary reinforcing support portion only by designing the shape of the modeled article 10 with a CAD device or the like.

Based on the design of the molded article 10, the peripheral wall 30, and the reinforcing support portions 43a, the irradiation area of the light for irradiating the photocurable resin or the scanning pattern of the laser light is determined, and based on that, the actual pattern is actually used. The molding step is performed. When the molded article 10 is formed, the final curing process of the molded article 10 is performed, and then the reinforcing support portions 43a are cut or broken to obtain the molded article 10 having a desired three-dimensional shape. .

FIG. 14 shows a concrete example of the shape of the reinforcing support portion. As the modeled object, a floating island portion 28 is arranged at the center of the left and right wall-shaped portions 27, 27. A plurality of reinforcing support portions 47 are disposed between the floating island portion 28 and the wall-shaped portions 27, 27. The reinforcing support portion 47 has a horizontal arm shape with a rectangular cross section as a whole, and only a connecting portion between the wall-shaped portion 27 and the floating island portion 28 is a constricted portion 48 which is thinner than the other portions. . By providing the constricted portion 48 in this way, when the reinforcing support portion 47 is removed from the molded article after the molding of the molded article is completed, the constricted portion 48 can be easily broken or cut off.

[0056]

According to the method of molding a three-dimensional shaped object according to the present invention described above, the design of the reinforcing support portion is
Rather than based on the overall shape of the molded article, of the multiple photocured layers that make up the molded article, the planar shape of the two photocurable layers stacked one above the other is reinforced by the upper photocurable layer. By determining whether or not a support part is required and designing the layout shape of the reinforcement support part, it becomes possible to easily and quickly determine the necessity of the reinforcement support part, and to improve the design efficiency of the reinforcement support part. Can be improved.

The planar shape of the two photo-curing layers can be objectively judged based on a certain criterion to design the reinforcing support portion, which affects the skill and skill of the operator. Instead, proper design is possible. In particular, it is suitable for automatically designing the reinforcing support portion using a CAD device or a computer. This is because it is practically difficult to design mechanically because the amount of information to be handled is very large and the work time increases if the reinforcement support part is designed by judging from the shape of the entire molded article. Is. However, in the method of the present invention, since it is necessary to handle only the planar shape information of the two photo-curing layers at the same time, mechanization or automation is easy, and even if a normal CAD device or computer is used, it is sufficient. A practical design is possible. As a result of the above,
According to the present invention, it is possible to efficiently form a highly accurate three-dimensional shaped object without deformation or shape error by using an appropriate reinforcing support portion. It will be possible to greatly contribute to quality improvement or expansion of applications.

[Brief description of drawings]

FIG. 1 is a perspective view showing an entire outer shape of a modeled article, which represents an embodiment of the present invention.

FIG. 2 is a plan view in which a molded article is disassembled for each of a plurality of photo-curing layers.

FIG. 3 is a plan view in which a scanning direction of light in each photo-curing layer is added to the above figure.

FIG. 4 is a plan view showing a photo-cured layer formation pattern at a certain stage.

FIG. 5 is a plan view showing a photo-cured layer formation pattern in the next stage of FIG. 4;

FIG. 6 is a perspective view illustrating a method for determining the formation of a reinforcing support portion.

FIG. 7 is a diagram illustrating a method for determining the formation of a reinforcing support portion.

FIG. 8 is a plan view showing a formation pattern of a photo-curable layer in the next stage of FIG.

9 is a plan view showing a formation pattern of a photo-cured layer in the next stage of FIG.

FIG. 10 is a perspective view illustrating a method of determining the formation of a reinforcing support portion.

FIG. 11 is a diagram illustrating a method for determining the formation of a reinforcing support portion.

FIG. 12 is a plan view showing a formation pattern of a reinforcing support portion.

FIG. 13 is a vertical cross-sectional view of a modeled object and a supporting structure.

FIG. 14 is a perspective view showing another embodiment of the reinforcing support portion.

FIG. 15 is a flowchart showing the first half of the process in the embodiment of the present invention.

FIG. 16 is a flowchart showing the latter half of the process in the embodiment shown in the above figure.

FIG. 17 is a perspective view showing a conventional example.

FIG. 18 is a perspective view showing another conventional example.

FIG. 19 is a partially cutaway perspective view showing another conventional example.

[Explanation of symbols]

10 shaped article 12 eaves 14 dangling portion 21-26 photocurable layer 23b, 24b island portion 31 - 36 circumferential wall photocurable layer 43a, 43b, 45a, 45b reinforcing support member 50 and 60 grating pattern X _1, X _2, Y ₁ to Y ₅ intersections of grid lines a~n upper layer of the photocurable layer a'~h ', a ₁ ~n ₁ intersection 70 line theta ₁ of the lower layer of the photocurable layer, θ _2, θ angle

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Yoshimitsu Nakamura 1048, Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Works Co., Ltd.

Claims (3)

[Claims] 1. When a photocurable resin is irradiated with light to form a photocurable layer and a plurality of photocurable layers are stacked to produce a modeled product having a desired three-dimensional shape, In a method of forming a reinforcing support portion that connects a portion requiring reinforcement and a support structure for supporting the same by irradiating light on a photocurable resin and photocuring the resin, a two-layer photocurable layer stacked vertically is used. By comparing the planar shape, it is determined whether or not the reinforcing support portion is necessary for the upper photocurable layer, and if it is determined that the reinforcing support portion is necessary, for forming the upper photocurable layer. A method for manufacturing a three-dimensional shaped object, comprising additionally setting a light irradiation area corresponding to the reinforcing support portion in the light irradiation area. 2. The method according to claim 1, wherein when a region including a portion overlapping with the planar shape data of the lower photocurable layer is excluded from the planar shape data of the upper photocurable layer, A method for manufacturing a three-dimensional shaped object, which determines that if there is an isolated portion remaining in the planar shape data, a reinforcing support portion connected to this isolated portion is necessary. 3. The method according to claim 1 or 2, wherein respective contour line data is created from the planar shapes of the upper and lower photo-curing layers, and the same grid pattern is superposed on each contour line data to form each contour. When the intersection point with the line is found and the upper and lower contour line data are arranged at a prescribed interval, the angle between the line segment connecting the corresponding intersection points and the plane formed by the upper layer contour line data is the specified angle. A method of manufacturing a three-dimensional shaped object which determines that a reinforcing support portion connected to an intersection of contour line data of an upper photocuring layer is required in the following cases.