JP3903334B2 - 3D shape creation device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a three-dimensional shape creation apparatus for creating a three- dimensional model in a computer, and more specifically, in a boundary representation solid modeling system for creating a three-dimensional model in a computer, any arbitrary component that constitutes the model. The present invention relates to a three-dimensional shape creation device that creates a fillet surface or a cut-off surface that fits between two discontinuous surfaces that are adjacent to each other with a ridge line between them.
[0002]
[Prior art]
Conventionally, CAD (Computer Aided Design) and CAM (Computer Aided Manufacturing) are widely used as indispensable tools for design and production using computers.
[0003]
In general, as shown in FIG. 1, a CAD apparatus is based on a central processing unit (CPU) 1 that performs operations and processes of data, a memory 2 that stores programs and data, and programs and data based on human key operations. A keyboard 3 for inputting, a printer 4 for printing out programs and data, an image display device (CRT) 5 for displaying graphics and the like on a screen, and a mark displayed on the screen of the CRT 5 based on a human operation. And a mouse 6 for inputting data based on the movement, an auxiliary storage device 7 for storing a storage medium such as a floppy disk or a hard disk, and a bus line 8 for interconnecting them. When the user of the apparatus operates the keyboard 3 or mouse 6 to give an instruction, the contents are input, and a predetermined program is based on the instruction contents. Generate graphics, etc. by performing a calculation and processing in accordance with, and displays the figure and the like on the screen of the CRT 5.
[0004]
Among such CAD devices, in particular, in a three-dimensional CAD device that models and processes a three-dimensional figure (shape), a solid modeling method that handles a solid as a packed one has become mainstream.
[0005]
Solid models have superior features such as wireframe models that represent a solid as a collection of lines and surface models that represent a collection of faces, such as automatic processing such as analysis and processing. Have.
[0006]
When applying solid modeling to machine design, etc., there are rounding and chamfering processes applied to the corners of solid bodies as important shape deformation processes. The rounding process is a process of rounding a solid corner, and a surface called a fillet surface is embedded in the rounded corner. Further, the chamfering process is a process of cutting off a solid corner, and a surface called a chamfered surface is embedded in the chamfered corner.
[0007]
In general, the rounding operation is generally performed by first specifying the size of the fillet surface, specifying the common ridge line of the two surfaces forming the corners of the solid, and each of the curved surfaces in a plurality of sections perpendicular to the ridge line. The procedure is to find a tangent arc having a radius of the above specified size in contact with the cross section line and to generate a fillet surface by smoothly connecting the arcs in the plurality of cross sections. Note that the size of the fillet surface does not necessarily represent the radius of the tangent arc, and may be specified as the width of the fillet surface or the distance from the common ridge line to the contact point of the tangent arc. In these cases, the radius of the tangent arc is adjusted to satisfy the specified conditions.
[0008]
On the other hand, the chamfer processing operation specifies the size of the chamfered surface, specifies the common ridgeline of the two surfaces forming the corners of the solid, and each of the curved surfaces in a plurality of cross sections perpendicular to the ridgeline. A tangential arc with a radius of the specified size that touches the cross-section line is obtained, a straight line segment connecting the two contact points in the cross-sections is obtained, and the angle drop surface is generated by connecting the straight line segments. The procedure is to do. Note that the size of the chamfered surface does not necessarily represent the radius of the tangent arc, and may be specified as the width of the chamfered surface or the distance from the common ridge line to the contact point of the tangent arc. In these cases, the radius of the tangent arc is adjusted to satisfy the specified conditions.
[0009]
Here, a boss hole-like partial shape exists on one or both of the two surfaces forming the corner of the solid, and the designated fillet surface or the cut-off surface is the boss hole-like portion. May interfere with shape. In such a case, generally, a fillet surface and a cut-off surface cannot be generated.
[0010]
[Problems to be solved by the invention]
However, in the conventional rounding and chamfering method, there is a problem in that when the fillet surface and the chamfered surface generated with the above specified size are embedded in the original shape, there is a possibility that they interfere with the boss hole-like shape. To do.
[0011]
In such a situation, the operation has been temporarily canceled by canceling the operation, changing the shape before embedding, or changing the size of the fillet surface or the angle drop surface.
[0012]
However, in many cases, the desired shape can be obtained only by changing the size of the fillet surface and the angle drop surface while maintaining the values specified in the drawings and the like and maintaining the shape of the boss hole.
[0013]
Therefore, the present invention solves such a problem, and is able to add a fillet surface and a chamfered surface of a specified size while maintaining a boss hole-like partial shape, and a tertiary processing that performs rounding processing and chamfering processing. An object is to provide an original shape creation device .
[0014]
More specifically, the present invention relates to a three-dimensional shape creation apparatus for creating a three- dimensional model in a computer , and a rounding deformation in which a fillet surface that smoothly connects two pairs forming a corner portion of a solid is embedded. When applying the operation, if you want to generate the boss hole-like partial shape of the solid and the shape that the generated fillet surface interferes with, save the boss hole-like shape once separated from the solid. Another object of the present invention is to provide a three-dimensional shape creating apparatus , wherein a fillet surface is generated for a partial solid remaining after separation, and the separated solid is stored again.
[0015]
Further, the present invention provides a three-dimensional shape creation apparatus for creating a three- dimensional model in a computer when applying a chamfering deformation operation for embedding a chamfered surface connecting two pairs forming a corner portion of a solid. If you want to generate the boss hole-like partial shape of the solid and the shape that the generated angle drop surface interferes, save the boss hole-like shape once separated from the solid and separated An object of the present invention is to provide a three-dimensional shape creating apparatus characterized by generating a chamfered surface with respect to the remaining partial solid and combining the stored separated solid again.
[0016]
Furthermore, when performing rounding or chamfering processing that interferes with the boss hole shape, the present invention stores the boss hole-like shape once separated from the solid, and fillets or chamfered surfaces with respect to the remaining partial solid after separation. In order to combine the stored separated solid again, the surface corresponding to the connecting portion of the partial solid to be separated and the partial solid to be separated is stored, and the stored surface and It is an object of the present invention to provide a three-dimensional shape creation apparatus characterized by performing a coalescing process efficiently by performing a coalescing process in consideration of only the surrounding surface and a surface belonging to a separated solid.
[0017]
[Means for Solving the Problems]
In order to achieve such an object, according to the first aspect of the present invention, in a three-dimensional shape creation apparatus for creating a three- dimensional model in a computer , two surfaces forming a corner portion of a solid are smoothly connected. When applying a rounding deformation operation that embeds a fillet surface, when generating a shape that interferes with the boss hole-like partial shape included in the solid and the generated fillet surface, the boss hole-like shape is separated from the temporary solid. It is characterized in that it has a coalescing means for generating a fillet surface for the partial solid remaining after separation, and combining the separated solid again.
[0018]
According to a second aspect of the present invention, in the three-dimensional shape creation device for creating a three- dimensional model in a computer , a chamfer deformation operation for embedding a chamfered surface connecting two pairs forming a corner portion of a solid. When creating a shape that interferes with the boss hole-like partial shape included in the solid and the generated chamfered surface, the boss hole-like shape is separated from the temporary solid and stored and separated. It is characterized by having a uniting means for generating a chamfered surface with respect to the remaining partial solid and combining again the separated solid that has been stored.
[0019]
According to a third aspect of the present invention, in the three-dimensional shape creating apparatus according to the first or second aspect, when the coalescing means performs a rounding or chamfering process that interferes with the boss hole shape, the boss hole-like shape is obtained. Separated from the temporary solid, saved, generated fillet surface or chamfered surface for the remaining partial solid, and separated from the separated partial solid to merge the stored partial solids again It is characterized in that the surface corresponding to the connection part with the partial solid to be saved is stored and combined only in consideration of the saved surface, the surface surrounding the surface, and the surface belonging to the partial solid Yes.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
[Features of the present invention]
The three-dimensional shape creation device according to the present invention is a ridgeline shared by two pairs of surfaces forming a corner of a solid by a CAD device capable of handling a solid model having phase data representing a connection relation between surfaces. When the fillet surface and the angle drop surface connecting the two surfaces with the specified size along the specified ridgeline are generated, the fillet surface and the angle drop surface to be embedded are When the boundary curve interferes with an existing boss hole-like part, it is used to maintain a boss hole-like shape and generate a fillet surface and a cut-off surface of a specified size.
[0024]
In the case of performing the rounding or chamfering process as described above, the process is performed as shown in FIG.
[0025]
In the following explanation, only the rounding deformation process for embedding the fillet surface is described. However, the present invention is not limited to this, and the fillet surface is chamfered and the chamfer deformation process is performed by replacing the rounding deformation process with the chamfer deformation process. It is also effective as a processing means.
[0026]
Referring to FIG. 2, first, a shape separation step (step S <b> 1) for separating a boss hole-like part from a solid that generates a fillet surface is performed.
Here, the boss hole-like portion or the boss hole-like shape means, for example, shapes as shown in FIGS. 4 (a) and 4 (b). The partial shape indicated by the thick line in FIG. 4A is an example of the boss portion, and the partial shape indicated by the thick line in FIG. 4B is an example of the shape of the hole portion.
Further, in the shape separation step of step S1, the surface existing at the joint portion between the boss hole-like partial shape to be separated and the partial solid that remains after separation is stored.
[0027]
Next, the partial shape is separated in the shape separation step S1, and a fillet surface generation step (step S2) for embedding a fillet surface is performed on the remaining partial shape.
In the following literature, the shape of the boundary of the fillet surface is calculated by finding a plurality of contact points of spheres and arcs that touch the two surfaces forming the corner of the solid, and obtaining these complementary curves. A method of generating a fillet surface by obtaining a plurality of arcs from the obtained contact points and connecting them smoothly is described. In the fillet surface generation step S2 shown in FIG. 2, the existing method shown in the following document [1] is used.
T. Harada, et.al, Variable-Radius blending by Using Gregory Patches in Gemetric Modeling, EUROGRAPHICS'91, Eurographics Association, pp.507-516, 1991.… [1]
[0028]
Further, a shape merging step (step S3) for combining the boss hole-like partial shape separated in the shape separation step S1 of FIG. 2 with the partial shape deformed in the fillet surface embedding step 2 is performed.
At this time, the surfaces that existed in the joint portion between the separated shape and the remaining shape that has been saved in the shape separation step S1, and the surrounding surfaces and all the surfaces constituting the boss hole shape Perform the coalescing process considering only the above. Thereby, since it is not necessary to perform interference determination for shapes other than the portion that generates the fillet surface, it is possible to efficiently perform the merging process.
Even when the chamfered surface is embedded by chamfering, exactly the same means can be applied from the shape separating step S1 to the shape merging step S3. In this case, in the fillet surface generation step 2, the contact point of the sphere or arc that touches the pair of two surfaces forming the corner of the solid is obtained, and by calculating these complementary curves, the shape of the boundary of the angle drop surface is obtained. After calculation, a plurality of straight line segments connecting corresponding contact points on the two surfaces to be paired are obtained, and the angle drop surface is generated by smoothly connecting these segments.
[0029]
{Operation by the present invention}
According to the feature of the present invention described above, when the fillet surface interferes with the boss hole-like shape in the rounding process of the solid corner, the size specified while maintaining the boss hole-like shape. The fillet surface can be embedded. Similarly, in the chamfering process of the three-dimensional corner portion, when the cut-off surface interferes with the boss hole-like shape, the cut-off surface having the specified size can be embedded while maintaining the boss hole-like shape.
[0030]
[First embodiment]
Hereinafter, embodiments of the present invention described above will be described in detail with reference to the drawings. FIG. 3 is a flowchart showing a first embodiment of the three-dimensional shape creation apparatus of the present invention. This embodiment is executed by a program given in advance to a normal CAD apparatus as shown in FIG .
[0031]
In this embodiment, the boss hole-like shape as shown in FIG. 5B and the other ridge line interfere with each other at a specified size at the corner of the solid shown in FIG. 5A generated as a solid model. A fillet surface with a part shall be embedded.
[0032]
The operation of this embodiment when performing such processing will be described below with reference to the drawings.
In the present embodiment, in order to perform the processing as described above, first, in step S101 in FIG. 3, the user of the CAD device forms the fillet surface creation position and the corner of the solid B that creates the fillet surface. The common edge E0 of the curved surfaces F1 and F2 forming a pair and the size of the fillet surface are designated (FIG. 6). In this case, the size of the fillet surface designates the radius of the tangent arc from which the fillet surface is generated. This radius is called a rounding radius.
[0033]
Next, in step S102 in FIG. 3, it is determined whether there is a boss hole-like shape on F1 and F2. In this determination, if there is no boss hole-like shape (No in step S102), the solid itself is set as shell B, and the process proceeds to step S104. If there is a boss hole-like shape (Yes in step S102), the process proceeds to step S103. .
[0034]
In step 3, the boss hole-like shape is separated and this shape is defined as shell A. Further, the remaining shape after separation is referred to as shell B (FIG. 7). At this time, the surface Fc existing at the joint portion between the shell A and the shell B is stored.
[0035]
Here, the steps S101 to S103 in FIG. 3 correspond to the shape separation step S1 in FIG.
[0036]
In step S104, the fillet surface is embedded in the shell B using the method described in the above document [1] (FIG. 8).
[0037]
In step S105, it is determined whether the boss hole shape is separated in step S102.
In this determination, when the separation-shaped shell A does not exist (No in step S105), the process ends. On the other hand, when the separation shape shell A exists (Yes in step S105), the process proceeds to step S106.
[0038]
Here, the steps S104 to S105 in FIG. 3 correspond to the fillet surface generation step S2 in FIG.
[0039]
In step S106, it is determined whether or not the shell A needs to be deformed when the shell A and the shell B are merged after step S108. This determination is made based on the table shown in FIG. Each situation shown in FIG. 9 is shown in (a) to (d) of FIG.
In this determination, if it is not necessary to deform the shell A (No in step S106), the process proceeds to step S108, and if it is necessary to deform (Yes in step S106), the process proceeds to step S107.
[0040]
In step 7, the shape of the shell A is deformed. Specifically, the side surface of the shell A is extended in the direction from the shell A to the shell B. An example of this process is shown in (a) and (b) of FIG.
Referring to FIGS. 11A and 11B, in order to unite shell A and shell B, a set operation between shells is performed. At this time, the applied calculation differs depending on whether the shell A is a boss shape or a hole shape. For this reason, in step S108, it is determined whether the shell A is a boss shape or a hole shape.
In this determination, if the shell A has a boss shape (boss shape in step S108), the process proceeds to step S109. If the shell A has a hole shape (hole shape in step S108), the process proceeds to step S110.
[0041]
In step S109, a sum set operation is performed, and shell A and shell B representing the boss shape are merged. At this time, the set operation is performed only on the surface Fc and the surrounding surfaces saved in step S103 and all the surfaces belonging to the shell A. That is the end of the process. An example of the shape resulting from this processing is shown in FIG.
[0042]
In step S110, a set operation of products is performed to combine shell A and shell B representing the hole shape. At this time, the set operation is performed only on the surface Fc and the surrounding surfaces saved in step S103 and all the surfaces belonging to the shell A. That is the end of the process. The product set operation is an operation in which a common part between shells is used as a result shape. An example of the shape resulting from this processing is shown in FIG.
[0043]
Here, the steps S106 to S108 in FIG. 3 correspond to the shape merging step S3.
[0044]
{Effects of the first embodiment}
According to the three-dimensional shape creation apparatus of this embodiment, when the fillet surface interferes with the boss hole-like shape in the rounding process of the three-dimensional corner, the fillet having the specified size while maintaining the boss hole-like shape. The surface can be embedded.
[0045]
As mentioned above, although explained based on the example of a figure, this invention is not limited to the above-mentioned example, and when a chamfering process interferes with a boss hole-like shape when performing chamfering processing like the above-mentioned example. Further, it is possible to bury the angle drop surface having a specified size while maintaining the boss hole-like shape.
[0046]
【The invention's effect】
According to the present invention described above, when the fillet surface interferes with the boss hole-like shape in the rounding process of the three-dimensional corners, the fillet having the specified size is maintained while maintaining the boss hole-like shape. The surface can be embedded.
That is, when the fillet surface interferes with the boss hole-like shape in the rounding process of the three-dimensional corners, it is possible to embed the fillet surface having a specified size while maintaining the boss hole-like shape. Similarly, in the chamfering process of the three-dimensional corner portion, when the cut-off surface interferes with the boss hole-like shape, the cut-off surface having the specified size can be embedded while maintaining the boss hole-like shape.
[0047]
More specifically, the present invention relates to a three-dimensional shape creation apparatus for creating a three- dimensional model in a computer , and a rounding deformation in which a fillet surface that smoothly connects two pairs forming a corner portion of a solid is embedded. When applying the operation, if you want to generate the boss hole-like partial shape of the solid and the shape that the generated fillet surface interferes with, save the boss hole-like shape once separated from the solid. The fillet surface can be generated for the remaining partial solid after separation, and the stored separated solid can be combined again.
[0048]
Further, the present invention provides a three-dimensional shape creation apparatus for creating a three- dimensional model in a computer when applying a chamfering deformation operation for embedding a chamfered surface connecting two pairs forming a corner portion of a solid. If you want to generate the boss hole-like partial shape of the solid and the shape that the generated angle drop surface interferes, save the boss hole-like shape once separated from the solid and separated A chamfered surface can be generated for the remaining partial solid, and the stored separated solid can be merged again.
[0049]
Furthermore, when performing rounding or chamfering processing that interferes with the boss hole shape, the present invention stores the boss hole-like shape once separated from the solid, and fillets or chamfered surfaces with respect to the remaining partial solid after separation. In order to combine the stored separated solid again, the surface corresponding to the connecting portion of the partial solid to be separated and the partial solid to be separated is stored, and the stored surface and By performing the coalescence process in consideration of only the surrounding surfaces and the surfaces belonging to the separated solid, the coalescence process can be performed efficiently.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing a configuration of a normal CAD device.
FIG. 2 is a process chart conceptually showing a flow in the present invention.
FIG. 3 is a flowchart showing an embodiment of the rounding and chamfering processing method of the present invention.
FIG. 4 is an explanatory view showing an example of a boss hole-like shape. (A) is a shape containing a boss | hub part. (B) is a shape including a hole portion.
FIG. 5 is an explanatory diagram showing an example of this embodiment . (A) is an example which embeds the fillet surface of the magnitude | size designated to the corner | angular part of a solid | solid. (B) is an example of embedding a fillet surface having a boss hole-like shape and a portion that interferes with other twill lines.
FIG. 6 is an explanatory diagram showing an example of specifying a rounding ridge line in step S101 in the embodiment.
FIG. 7 is an explanatory diagram showing an example of shape separation in step S103 in the embodiment.
8 is an explanatory diagram showing an example of an embedded fillet surface at step S104 in the above embodiment.
9 is a table for determining whether it is necessary to deform the shell A in step S106 in the above embodiment.
10 is an explanatory view showing an example of a shape to be determined in step S106 in the above embodiment.
11 is an explanatory diagram showing an example of deformation of the shell A in step S107 in the above embodiment.
12 is an explanatory diagram showing an example of merging result in step S109 in the above embodiment.
13 is an explanatory diagram showing an example of merging result in step S110 in the above embodiment.
[Explanation of symbols]
1 CPU
2 Memory 3 Keyboard 4 Printer 5 CRT
6 Mouse 7 Auxiliary storage 8 Bus line

Claims (3)

In a 3D shape creation device that creates a 3D model in a computer ,
When applying a rounding deformation operation that embeds a fillet surface that smoothly connects two surfaces forming a corner of a solid, the boss hole-like partial shape included in the solid interferes with the generated fillet surface When the shape to be generated is generated, the boss hole-like shape is separated from the temporary solid and stored, a fillet surface is generated for the remaining partial solid, and the stored solid is again stored. A three-dimensional shape creating apparatus comprising a coalescing means for coalescing . In a 3D shape creation device that creates a 3D model in a computer ,
When applying a chamfer deformation operation that embeds a chamfered surface that connects two surfaces forming a corner of a solid, the boss hole-like partial shape included in the solid interferes with the generated chamfered surface When generating the shape to be cut, the boss hole-like shape is separated from the temporary solid and stored, and a chamfered surface is generated for the remaining partial solid after separation, and the stored solid is again stored. A three-dimensional shape creating apparatus comprising a coalescing means for coalescing the two . When performing the rounding or chamfering process that interferes with the boss hole shape, the coalescing means separates and stores the boss hole-like shape from the temporary solid, and fillets or corners are dropped on the remaining partial solid after separation. In order to generate a surface and to combine the stored separated solid again, the surface corresponding to the connection portion between the separated partial solid and the separated partial solid is stored and stored. 3. The three-dimensional shape creating apparatus according to claim 1, wherein the three-dimensional shape creating apparatus combines the surfaces in consideration of only the surfaces, the surfaces around the surfaces, and the surfaces belonging to the partial solid.

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