JP2005074931A - Rapid prototyping modeling method and model - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for obtaining a shaped article in which microholes are not shrunk or do not disappear by the conversion of three-dimensional CAD data when the microholes are shaped by rapid prototyping. <P>SOLUTION: The method for producing the shaped article comprises dividing the shaped article into a plurality of laminated parts using a three-dimensional CAD model, sequentially hardening the shaping materials of the divided laminated parts, and then stacking the laminated parts. The method is characterized by minimizing the shaping error not greater than a laminating thickness. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a rapid prototyping modeling method such as stereolithography, powder sintering, and powder fusion using three-dimensional CAD model data, and a modeled article.

  A conventional modeling method using rapid prototyping using three-dimensional CAD model data is disclosed in Japanese Patent Application Laid-Open No. 2002-166481. This modeling method will be described with reference to FIG.

  First, the solid data 51 created by three-dimensional CAD is converted 52 into contour line data sliced in the horizontal direction.

  Based on the contour line data, coordinate conversion 53 is performed on the locus data of the beam for curing the powdery modeling material. Thereafter, a modeling material, for example, powdered plastic, is spread (spread) on the thickness (slice pitch) of the contour line data to form a powdered plastic thin film 54.

  Then, the powder plastic molding material is cured 55 by irradiating a light beam in the thickness direction on the spread powder plastic. The modeling material is laid on the same thickness as the previous layer so as to be stacked thereon, and the stacked modeling material is similarly irradiated with a light beam (particle beam) to be thermally cured. This is sequentially repeated 56 times as many as the number of contour line data (lamination), and a product P as if it is buried in the powder is formed, and when it is taken out from the powder 57, it is the same as 57-dimensional CAD model data A shaped product P is generated.

  (51a) to (57g) shown on the right side of FIG. 5 show images of the shaped products to be generated corresponding to (51) to (57) of FIG. In this example, a process of generating a shaped product P is shown.

  Here, when the solid data is sliced in the horizontal direction and the contour line data is created in the process of 52 shown in FIG. 5, if there is a hardened area less than the stacking thickness in the stacking direction, the difference is determined as the hardened area. Is done. Then, since all of the stacking thickness is cured in the process 55 shown in FIG. 5, the shaped product is substantially larger by the thickness of the difference of the stacking thickness than the desired dimensions.

  For example, as shown in FIG. 1A, when the stacking thickness 1 is 0.15 mm and the hardening area height 2 on the data is 0.17 mm, the area 3 to be hardened is divided into three by the slice data dividing surface 4. (In some cases, it is divided into two).

  That is, in the case of FIG. 1A, the cured area is divided into three parts having a height 7 of 0.01 mm, a height 8 of 0.15 mm, and a height 9 of 0.01 mm. Since curing of the direction is only ON / OFF of the irradiation beam, even if it is desired to cure the height of 0.01 mm, the stacking thickness of 0.15 mm is cured, so finally the cured result 5 The height of 0.45 mm shown in the curing area height 6 will be cured. For this reason, an unnecessary area (high area) that does not exist in the 3D CAD data (different from the 3D CAD data) is hardened.

  Hardening of an unnecessary area different from the three-dimensional CAD data is particularly noticeable when there are fine holes. For this reason, in particular, when layered modeling is performed using three-dimensional CAD model data having fine holes, there is a phenomenon that the holes of the shaped product become smaller than the desired hole dimensions.

Japanese Patent Laid-Open No. 2002-166481

  In the prior art, since the hardened region is in the stacking direction, there is a method of improving the modeling accuracy by reducing the thickness of the stack. However, there is a demerit of lack of curing due to non-uniformity of the modeling material distribution and an increase in modeling time (when the lamination thickness is thin, the number of laminations increases, so the modeling time increases), generally given in advance Irradiation curing treatment is performed with the laminated thickness. Also in the present invention, it is necessary to spread a material with a certain thickness.

  In view of the above problems, an object of the present invention is to provide a rapid prototyping modeling method and a modeled article that obtain a highly accurate modeled product for a desired three-dimensional model.

  In the present invention, a powdery modeling material is laid, and on the laid modeling material, a particle beam including a light beam is irradiated in the thickness direction of the modeling material to be hardened, and is thermally cured and stacked thereon In the same way, lay the modeling material to the same thickness as the previous time, and irradiate the laminated modeling material with the particle beam in the same way to heat cure, and repeat this lamination of the modeling material and irradiation of the particle beam to form a modeled product In the rapid prototyping modeling method in which a fine hole penetrating a shaped article is formed together in the process of forming, the length of the fine hole has a height that is a multiple of the thickness of each laminate, and is above the fine hole. The lower surface comes to the boundary surface between each lamination | stacking, It is characterized by the above-mentioned.

  By rapid prototyping according to the present invention, it is possible to realize generation processing that does not block a plurality of fine holes, and to generate a desired mesh shaped article having fine holes.

  First, it demonstrates along FIG.

  As shown in FIG. 1B, for example, when the thickness 10 of the modeling material stack is 0.15 mm, the cured region height 11 is a multiple of the stacked height 10, and the upper and lower surfaces of the region 12 to be cured are By making it coincide with the slice data dividing surface 13, a desired curing result 14 is obtained.

  As can be understood from this description, the height of the fine hole formed in the molded product is the same as the thickness of the stack (0.15 mm) or a multiple (positive integer multiple), and the upper and lower surfaces of the fine hole are sliced data dividing surfaces. By making it coincide with (the boundary surface between the respective layers), a hole having a height of 0.15 mm is formed. In other words, by making the length of the microholes a multiple of the thickness of the stack and making the top and bottom surfaces of the microholes come to the boundary between each stack, it becomes a model in the process of forming a model for rapid prototyping Through holes can be formed together.

  A large number of fine holes can be formed in a mesh shape (mesh shape), and even if there are variations in accuracy, the thickness in the vertical direction can be ensured even if the vertical length is minimal. In order to make a fine hole without being blocked, it is desirable to form the upper and lower surfaces so as to extend along the boundary surface between the stacked layers.

  Unlike the divided planes to be separated, the boundary surface between the stacks is a bonding surface for heat welding, and is a partition boundary of the stacked structure.

  In the formation of fine holes, special attention must be paid to the shrinkage rate.

  The rapid prototyping shaped product is thermally cured / heat-welded with a light beam of a powdery shaped material (powdered plastic), so that the entire size becomes small. For this reason, the fine holes are particularly small and may lose the function of the holes.

  Therefore, the following measures were taken.

  First, in the conventional process shown in FIG. 2 (A), the external shape is created 20 by three-dimensional CAD, further fine holes are created 21, and then the shape data is multiplied by the shrinkage of modeling 22, contour lines Converted to data 23.

  In this case, even if the fine hole is made a multiple of the stacking height 10 in step 21 and the upper and lower surfaces of the region 12 to be hardened are made coincident with the slice data dividing surface 13, the shrinkage rate is applied to the fine hole in step 22. As a result, the fine hole is not a multiple of the stacking height 10, and the desired shape cannot be obtained as shown in FIG.

  In order to prevent this phenomenon, a high-precision modeling process was considered as shown in FIG.

  The external shape of the modeled product is created 24 by three-dimensional CAD, multiplied by the model data shrinkage rate 25, and then a minute hole is created 26, which is converted into contour data 27. By this method, even if the step of applying the shrinkage rate is entered, the desired hardening result 14 can be obtained by making the fine holes by a multiple of the stacking height 10 and making the upper and lower surfaces coincide with the slice data dividing surface 13.

  This will be described in more detail with reference to FIGS.

  As shown in FIG. 4A, the case where a shaped product having a plurality of fine holes is generated in a C-shaped model will be described.

  First, a C-shaped appearance is created on a three-dimensional CAD. 4A and 41B of FIG. 4 and the intervals between the holes are arranged to be a multiple of the laminated thickness 10 of FIG. 1B, and the cross-section of the micro holes is rectangular and linear. Keep parallel.

  When the shrinkage rate is applied to the model, the shrinkage rate is applied at the time when the C-shaped appearance shape is modeled before the fine holes are arranged, and the shrinkage rate is not applied to the fine holes. Thereafter, as shown in FIG. 4B, the three-dimensional CAD data in FIG. 4A is rotated by 90 degrees so that the axis of the fine hole is parallel to the laminated surface.

  And it is the modeling method of this invention to make the upper and lower surfaces of the area | region 12 to harden | cure match with the slice data division | segmentation surface 13. FIG. Thereafter, as shown in the prior art, the processing in steps 53 to 56 in FIG. 5 is performed, and the shaped product P is taken out in step 57. Here, the rotation by 90 degrees is an example of FIG. 4A, and there are actually various angles depending on the relationship between the axis of the fine hole and the laminated surface.

FIG. 4 shows an arbitrary cross section, but the plan view seen from the arrow S in FIG. 4A is as shown in FIG. In some cases, the cross-sectional area of the fine hole is 1 mm ² or less (the above problem is likely to occur when the cross-sectional area of the fine hole is 1 mm ² or less).

Therefore, here, a description will be given for a shaped product having holes in a mesh shape in which the interval between the fine holes is 1 mm ² or less. As shown in FIG. 4 (B), the molding material is cured by the contour data based on the data in which the axis of the hole is arranged and converted parallel to the laminated surface (for example, as shown in 53 of FIG. 5). The coordinates are converted to the trajectory data of the beam to be generated.

  For example, in FIG. 4A, if the three-dimensional CAD data is created as X, Y, Z data, and the X-axis direction is the slice direction and the Z-axis is the stacking direction, this is shown in FIG. As in (B), the data is converted into data X ′, Y ′, Z ′ having the Z ′ direction as the slice direction, and modeling is performed (in this case, the stacking direction is the X ′ direction).

  Thereafter, a thin powder is sprayed as shown by 54 (54d) in FIG. 5 for the thickness of the contour line data (usually 0.15 mm), and the material is cured by beam irradiation as shown by 55 (55e) in FIG. . This is repeated for the number of the contour line data (54 to 56 in FIG. 5, as if the buried product is taken out (57 in FIG. 5). As a result, the fine hole is reduced by the shrinkage rate, but the same as the three-dimensional model. An almost similar shaped product is generated.

  As described above, the steps after step 53 are the same as the prior art. However, in steps 51 and 52, as shown in FIG. 4, all the fine holes are straight and the cross section is a rectangular hole. 1 is a multiple of the stacking height (10 in FIG. 1), and the upper and lower surfaces of the region to be cured (12 in FIG. 1) coincide with the slice data dividing plane (13 in FIG. 1). This is characterized in that a desired curing result (14 in FIG. 1) is obtained.

  FIG. 4A shows the case of viewing from the arrow direction S in FIG. The fine holes (41 to 44) in FIG. 4A show the fine holes corresponding to FIG. FIG. 4A is an explanatory diagram in the case of one cross section, but shows a case where holes are formed in a mesh shape as shown in FIG.

The cross-sectional area of the fine hole is 1 mm ² or less as described above. Moreover, the space | interval of a fine hole is also 1 mm < ² > or less. As shown in FIG. 3B, the fine holes are required to be equidistant regardless of whether they are flat or curved. According to the present invention, such a case can be dealt with.

  Here, the reason why the fine hole becomes smaller than the desired shape or the fine hole disappears will be described. When converting three-dimensional CAD data having a minute hole into contour data, as shown in FIG. 3A, when a minute hole of hi-1 is between slice planes 30 to 33, when generating slice data, In the fine hole shape of hi-1, it is determined that the layer between 30/31 is cured, the layer between 31/32 is not cured, and the layer between 32/33 is cured, and as shown in FIG. As shown in FIG. 3B, the shape of the fine hole 1 is such that the top and bottom are crushed like hi-1. This is because the non-hardened region (between the upper surface of hi-1 and the sliced surface 31) of the fine holes of hi-1 between the sliced surfaces 30/31 and the hardened region (upper surface of hi-1 and the sliced surface 30). However, the hardening of the layer is only ON / OFF of the beam irradiation, and if the hardened area and the non-hardened area exist in the same X and Y coordinates between the layers, it is determined as the hardened area. Because. The same applies to the slice surfaces 32/33. 3A, there is a gap between the upper surface of the hi and the slice surface 34, and the lower surface of the hi and the slice surface 36, and the slice between the layers 34.35 and 35.36. In the XY coordinates of the surface hi, it is determined that it is a hardened region, and as a result, the fine hole disappears as shown by hi in FIG. This is a factor that the fine hole becomes smaller than the desired shape or that the fine hole disappears.

  On the other hand, in the case of the present invention, by setting the hardened region height 11 to be a multiple of the stacking height 10, and by matching the upper and lower surfaces of the region 12 to be hardened with the slice data dividing surface 13, the fine holes are desired. It is smaller than the shape or prevents the fine holes from disappearing. When the shrinkage rate is applied, the microholes are slightly reduced by the shrinkage rate, but the microholes do not disappear. This is important.

  Further, as an example of application to a product, the same applies to the case where a pulp mold papermaking mold is designed and manufactured by three-dimensional CAD. The case where there is a linear microhole on a three-dimensional CAD and the axes of the microholes are all parallel to each other is targeted ((A) of FIG. 1). When the three-dimensional CAD data is sliced and converted into contour line data ((B) in FIG. 1), the three-dimensional CAD data is rotationally converted and arranged so that the axis of the fine hole is parallel to the laminated surface ( As shown in FIG.

  In addition, as an application to other products, a molded product with good quality can be obtained by applying the present invention even when generating a shaped product having fine holes used for vent mesh parts, flow path filters, lighting louvers, etc. Can be obtained. Moreover, the said fine hole molded article is a papermaking type | mold of a pulp mold.

  According to the present invention, when modeling a fine hole for rapid prototyping, the three-dimensional CAD data is converted into data in which the axis of the fine hole is parallel to the slice surface, and the upper and lower surfaces of the region to be hardened are divided into slice data. By performing modeling after matching with the surface, it is possible to easily obtain a modeled product having a fine hole having a target cross-sectional area.

It is explanatory drawing for obtaining an understanding of this invention. It is explanatory drawing which compared and showed this invention and the prior art example. It is explanatory drawing of the cause which a microhole can be made small or disappears. It is a figure explaining the data conversion of the layered modeling by three-dimensional CAD. It is explanatory drawing of the modeling method by rapid prototyping.

Explanation of symbols

1 ... micropores,
41-44 ... fine holes,
3 ... Modeling powder material.

Claims (6)

Spread the powdered molding material,
For the molding material that has been laid down, the particle beam containing the light beam is irradiated in the thickness direction of the molding material to harden the part that you want to harden,
Lay the modeling material to the same thickness as the previous time so that it is stacked on it, and the laminated modeling material is irradiated with particle beams in the same way and thermally cured,
In the rapid prototyping modeling method of forming micro holes penetrating into the modeled product in the process of forming the modeled product by repeating the lamination of this modeling material and irradiation of particle beam,
The height of the fine hole has a height that is a multiple of the thickness of each laminate, and the top and bottom surfaces of the fine hole come to the boundary surface between the laminates. In the modeling thing made using the rapid prototyping modeling method according to claim 1,
A modeled object in which the upper and lower surfaces of the fine hole extend along a boundary surface. In the modeling thing made using the rapid prototyping modeling method according to claim 1,
The fine hole has a size of 1 mm 2 or less and is arranged in a mesh shape. The rapid prototyping modeling method according to claim 1,
Create the shape of the shaped product with 3D CAD,
Contour data that slices along the boundary surface is created from the data of the three-dimensional CAD,
A rapid prototyping modeling method, wherein an irradiation locus of the particle beam is drawn based on the contour line data. The rapid prototyping modeling method according to claim 4,
Create data by adding the fine holes after applying the shrinkage of modeling with modeling to the data of the three-dimensional CAD,
A rapid prototyping modeling method, characterized in that the contour line data is created based on data including the fine holes. In the modeling thing made using the rapid prototyping modeling method according to claim 5,
A rapid prototyping fine hole shaped high-precision shaped product characterized in that the shaped product is a papermaking model of a pulp mold.

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