WO2006137115A1

WO2006137115A1 - 3d cad data conversion method, device, and program

Info

Publication number: WO2006137115A1
Application number: PCT/JP2005/011266
Authority: WO
Inventors: Haruyasu Watanabe
Original assignee: Fujitsu Limited
Priority date: 2005-06-20
Filing date: 2005-06-20
Publication date: 2006-12-28

Abstract

A 3D CAD data conversion method converts 3D CAD data into an intermediate file of the standard format by a data conversion process. The method automatically detects a portion of a non-manifold body from the 3D CAD data and adds an arbitrary numeric value satisfying the relationship (tolerance value (mm)) < (arbitrary numeric value (mm)) ≤ (value greater than the tolerance value) as internal data to a portion of the non-manifold body in linear contact or point contact before performing the data conversion process.

Description

3D CAD data conversion method, apparatus and program

Technical field

The present invention relates to a 3D CAD data conversion method, apparatus, and program, and in particular, 3D CAD that converts 3D CAD data created by 3D CAD into a standard format called an intermediate file (or intermediate format). The present invention relates to a data conversion method, apparatus, and program. Background art

[0002] 3D CAD is a general tool used in the design and manufacture of mechanisms and devices. 3D CAD is widely used as a tool that embodies the shapes studied and imagined by designers and performs the entire design work from creation of design drawings. Currently, there are many 3D CADs, including so-called high-end and middle range, which are widely used. Here, high-end is defined as belonging to the high-performance, high-priced range of 3D CAD, and can be performed consistently from design to analysis and manufacturing. For example, ProZE, UG, CATIA (all are product names), etc. Point to. Also, the middle range is defined as a system specialized in design that belongs to a low-priced range, although the free-form surface function is weak even in 3D CAD. .

[0003] The 3D design tool uses 3D data such as CAE (analysis) and CAM (manufacturing support tool) that can be used only with 3D CAD. There are also tools to achieve this. Here, CAE (analysis) refers to a tool that evaluates in a virtual (virtual space), such as thermal 'structural' strength analysis, that cannot be evaluated without actually making a prototype. Also, CAM (Manufacturing Support Tool) is mainly used when manufacturing plastic products, etc., because the iron is cut into the opposite shape of the product and the material is injected there to manufacture it. Points to the module that coordinates the passage of the end mill (drill) at the time (digitization)

[0004] Normally, equipment is designed with a single 3D CAD system. However, 3D design data (for example, for pre-verification as described above and downstream processes (molds, etc.) Data conversion is required for 3D CAD data). In other words, 3D CAD Standard format that allows 3D CAD data to be exchanged between the data creation side (export side) and the side that performs pre-verification and downstream process using 3D CAD data (receiver side) Data conversion to is required.

[0005] In the data conversion processing of 3D CAD data, the data is converted on the export side and converted into a standard format called an intermediate file (or intermediate format), and the intermediate file is converted with a tool (other CAD or CAE) on the receiver side. Process to receive. Examples of intermediate files include the following.

[0006] STEP: An assembly hierarchy that is an international standard and has a higher conversion rate than IGES. Includes solid data in addition to surface and wireframe data.

[0007] IGES: US standard, basically surface and wireframe data. The assembly hierarchy is not converted.

[0008] DXF: A file format used in the interface with AutoCAD. Basically, 2Dff data is the mainstream, and few CADs can input and output 3D data.

[0009] Parasolid: Kernel (CAD engine). UG and SolidMX (both trade names) have this kernel. In CAD with the same kernel, shape transfer is much better than IGES and STEP, but the assembly hierarchy is often not passed.

[0010] When an intermediate file is received as described above, problems may occur during data conversion due to differences in tolerance values (model tolerance values) and internal data structures of each CAD. In general, when creating a 3D model, it is necessary to set the accuracy of the 3D model. In particular, in the 3D model with a free-form surface, the shape is expressed as a function. You may not be able to connect with. When connecting with Omm and measuring the distance between parts, for example, if it is about lZlOOOOOmm, there is no problem in practical use, so it is judged that Omm is coming even if it is far away. At that time, V is the threshold value used to determine whether it is V, and it is far away! /, The value is the tolerance value (model tolerance). In other words, when the end points are separated, the tolerance value is used to determine how many millimeters are attached to the border or whether to judge that they are separated.

[0011] In addition, all three-dimensional design tools have a common defect (error), which is a barrier during data conversion. A typical defect is “non-manifold”. Non-various The body refers to the part where the thickness of a member or the like is 0, either by itself or by two or more solids (a clogged body) in line contact or point contact.

FIG. 1 is a perspective view showing an example of a non-manifold. Figure 1 shows an example where two solids 1, 2 are in point contact at site 3. FIG. 2 is a perspective view showing another example of a non-manifold. Figure 2

An example where two solids 1 and 2 are in line contact at part 4 is shown.

[0013] As data conversion methods for 3D CAD data, methods such as those described in Patent Document 1 and Patent Document 2 have been proposed.

Patent Document 1: Japanese Patent Laid-Open No. 2000-11013

Patent Document 2: JP 2000-29918 A

Disclosure of the invention

Problems to be solved by the invention

[0014] A force that is a “non-manifold” that should be a defect in the three-dimensional world.

There are some shapes that can exist in reality, such as 90-degree bending, etc., and when it is desired to create a 2D drawing at the same time in 3D CAD, such as a non-manifold

In some cases, the shape of "

[0015] Yes! / When converting 3D CAD data to other 3D CAD, CAE, CAM, etc., data may be corrupted on the tool receiving the 3D CAD data. In such a case, if the solid body becomes a hollow body or part of the surface is peeled off!

[0016] When data is broken, the data is corrected either on the writing side or on the receiving side. However, since the man-hours for manual correction are generated, the development process of mechanisms and devices is complicated. It is a factor that becomes longer and longer.

[0017] At the time of data conversion of 3D CAD data as described above, it is one of the problems in 3D CAD that data conversion processing is performed so as not to cause problems.

[0018] Therefore, the present invention is to provide a 3D CAD data conversion method, apparatus, and program capable of performing data conversion processing of 3D CAD data as described above without causing any inconvenience! And

Means for solving the problem [0019] The above problem is a 3D CAD data conversion method for converting 3D CAD data into an intermediate file in a standard format by data conversion processing, and automatically processing the non-polymorphic part of the 3D CAD data Detect and satisfy the relationship of (tolerance value (mm)) く (arbitrary numerical value (mm)) ≤ (a value greater than the tolerance value) as internal data at the line contact or point contact of the non-manifold This can be achieved by a 3D CAD data conversion method characterized in that the data conversion process is performed by giving an arbitrary numerical value.

[0020] The above problem is a 3D CAD data conversion device that converts 3D CAD data into an intermediate file in a standard format by data conversion processing, and automatically converts the 3D CAD data force non-polymorphic part. (Tolerance value (mm)) (arbitrary numerical value (mm)) ≤ (a value greater than the tolerance value) as the internal data for the detection means and the line contact or point contact of the non-manifold! It can also be achieved by a three-dimensional CAD data converter characterized by comprising means for performing the data conversion processing after assigning an arbitrary numerical value satisfying the following relationship.

[0021] The above-described problem is a program for causing a computer to convert 3D CAD data into a standard format intermediate file by data conversion processing, and for the computer to store the 3D CAD data force non-manifold part. (Tolerance value (mm)) <(Tolerance value (mm)) ≤ (Tolerance value) The internal data of the part where the computer makes line contact or point contact with the non-manifold is automatically detected. This can also be achieved by a program characterized by including a procedure for applying an arbitrary numerical value satisfying the relationship of (a value greater than the value) and performing the data conversion process.

The invention's effect

[0022] According to the present invention, there is an effect that it is possible to realize a 3D CAD data conversion method, apparatus, and program capable of performing data conversion processing of 3D CAD data without causing any inconvenience! It is done.

Brief Description of Drawings

FIG. 1 is a perspective view showing an example of a non-manifold.

FIG. 2 is a perspective view showing another example of a non-manifold.

FIG. 3 is a perspective view showing an example of hem bending.

FIG. 4 is a side view showing the hem bending shown in FIG. FIG. 5 is a perspective view showing an example of 90-degree bending.

FIG. 6 is a plan view showing the 90-degree bending shown in FIG.

FIG. 7 is a flowchart for explaining an embodiment of the 3D CAD data conversion method according to the present invention.

FIG. 8 is a perspective view of a computer system constituting one embodiment of a 3D CAD data conversion apparatus according to the present invention.

FIG. 9 is a block diagram showing a main part of the main body shown in FIG.

FIG. 10 is a perspective view for explaining processing in the case of hem bending.

Explanation of symbols

[0024] 11, 12 Non-manifold

100 computer system

101 Main unit

102 display

201 CPU

BEST MODE FOR CARRYING OUT THE INVENTION

[0025] Hereinafter, embodiments of the 3D CAD data conversion method, apparatus, and program according to the present invention will be described with reference to the drawings.

Example

[0026] When exchanging 3D CAD data between different types of 3D CAD, or converting 3D CAD data for CAE, CAM, etc., in most cases, 3D CAD data is intermediated by data conversion processing. Convert to standard format called file (or intermediate format).

[0027] The non-manifold is a defect in which the thickness of the member or the like becomes 0 as described with reference to FIGS. 1 and 2, for example, like hem bending and 90-degree bending, In some cases, designers have made nonmanifolds.

FIG. 3 is a perspective view showing an example of hem bending, and FIG. 4 is a side view showing the hem bending shown in FIG. As shown in Fig. 3 and Fig. 4, hem bending (folding) is a common shape for sheet metal casings, etc., and by bending the end face, strength is increased and at the same time an R shape is formed at the corner. In reality, there can be a shape that is in line contact with the part 11 shown in FIG. In dimensional CAD, it is treated as a non-manifold, that is, as an infeasible shape.

FIG. 5 is a perspective view showing an example of 90-degree bending, and FIG. 6 is a plan view showing the 90-degree bending shown in FIG. As shown in Figs. 5 and 6, the 90-degree bend is a sheet metal bend similar to the hem bend, and the edges make line contact at the bend joint. In reality, there may be a shape that is in line contact with the region 12 shown in FIGS. 5 and 6, but it is treated as a non-manifold, that is, a shape that does not hold on many 3D CADs.

[0030] When 3D CAD data having the non-manifold defects as described above is converted, the data may be corrupted on the tool on the receiver side. In such a case, the shape of the non-manifold cannot be expressed (that is, cannot be realized), so the shape cannot be formed as a solid solid, and surface data is obtained.

Therefore, the present invention automatically detects a part corresponding to a non-manifold before converting 3D CAD data into an intermediate file by 3D CAD on the writing side.

Next, it is necessary to calculate a numerical value for avoiding non-manifolds. The tolerance value is a model accuracy set by each tool, and is an area that can be customized by the user. Therefore, first, the tolerance value of the tool is detected, and the optimum value for avoiding non-manifolds is derived for the tolerance value. The optimal value is an arbitrary value larger than the tolerance value because the non-manifold cannot be avoided unless the value is larger than the tolerance value. The upper limit of any numerical value can be customized to an optimal numerical value for manufacturing viewpoint.

[0033] Arbitrary numerical values derived at the end are assigned to sites corresponding to non-manifolds to avoid non-manifolds. At this time, the original shape is maintained without correcting the shape.

[0034] Thereafter, the data is converted into a conventional general intermediate format (STEP, IGES, etc.).

FIG. 7 is a flowchart for explaining an embodiment of the 3D CAD data conversion method according to the present invention. In this embodiment of the 3D CAD data conversion method, an embodiment of the 3D CAD data conversion apparatus according to the present invention is used. FIG. 8 is a perspective view of a computer system that constitutes an embodiment of the 3D CAD data conversion apparatus according to the present invention, and FIG. 9 is a block diagram showing the main part of the main body shown in FIG. A computer system 100 shown in FIG. 8 includes a main body 101 incorporating a CPU, a disk drive, and the like, a display 102 that displays an image on a display screen 102a according to an instruction from the main body 101, and a variety of computer systems 100 A keyboard 103 for inputting information, a mouse 104 for specifying an arbitrary position on the display screen 102a of the display 102, an external database, etc. can be accessed to download programs stored in other computer systems. It has a modem 105.

[0037] The power stored in the portable recording medium such as the disk 110, the 3D CAD function or 3D in the computer system 100 downloaded from the recording medium 106 of another computer system using a communication device such as the modem 105 Programs that have a CAD data conversion function (3D CAD software or 3D CAD data conversion software) are input to the computer system 100 and compiled. The 3D CAD data conversion program according to the present invention includes such 3D CAD data conversion software.

The computer-readable storage medium according to the present invention also has a recording medium force such as the disk 110 storing the three-dimensional CAD data conversion program according to the present invention. The recording medium constituting the computer-readable storage medium is not limited to a portable recording medium such as a disk 110, an IC card memory, a floppy (registered trademark) disk, a magneto-optical disk, or a CD-ROM. It includes various recording media accessible by a computer system connected via a communication device or communication means such as modem 105 or LAN.

In FIG. 9, the main unit 101 of the computer system 100 includes a CPU 201 connected by a bus 200, a memory unit 202 including RAM and ROM, a disk drive 203 for the disk 110, and a hard disk drive (HDD) 204. Become. In this embodiment, the display 102, the keyboard 103 and the mouse 104 are also connected to the CPU 201 via the bus 200. These may be directly connected to the CPU 201. The display 102 may be connected to the CPU 201 via a well-known graphic interface (not shown) for processing input / output image data.

Note that the configuration of the computer system 100 is not limited to the configuration shown in FIGS. 8 and 9, and various known configurations may be used instead.

[0041] Steps S1 to S6 in the process shown in FIG. 7 are the steps for exporting to create 3D CAD data. It is executed by the CPU 201 of the side computer system 100. Steps S7 and S8 are executed by the CPU 201 of the computer system 100 on the receiver side that performs pre-verification and downstream processing using an intermediate file obtained by performing data conversion processing on the 3D CAD data. Needless to say, the same computer system 100 may be used as the writing side and the receiving side computer system.

In step S1, 3D CAD data relating to a 3D model (shape) of a device or the like to be designed is created by a known method using a 3D design tool such as 3D CAD. In step S2, the presence / absence of a part corresponding to the non-manifold is determined by performing a known shape test. If the decision result in the step S2 is NO, the process advances to a step S6 described later. On the other hand, if the decision result in the step S2 is YES, the process advances to a step S3.

[0043] In step S3, a tolerance value (model allowable value) of the three-dimensional CAD is detected. Step S4 automatically calculates the optimum value for tolerance value. In step S5, the calculated arbitrary numerical value is automatically given to the part corresponding to the non-manifold. In step S6, a known data conversion process is performed on the 3D CAD data to convert it into a desired intermediate file.

[0044] In step S7, the intermediate file obtained by the data conversion process is received by the tool on the receiving side. In step S8, the intermediate file is analyzed by a well-known method to perform a shape check of the three-dimensional model, and the process ends. Pre-validation and response to downstream processes (molds, etc.) can be performed through shape check, and the shape can be modified or changed as necessary.

FIG. 10 is a perspective view for explaining the process of step S4 in the case of hem bending. Figure

In the example of hem bending as shown in Fig. 10, when the distance between the edge 21 and the surface 22 is measured, it is Omm, which is a non-manifold. If the 3D CAD data is converted to an intermediate file by data conversion processing in this state, the 3D model will be destroyed by the tool on the receiver side. Specifically, if a non-manifold part is detected with the tool on the receiver side, it will be judged as a defect, and it will be converted as a 3D model that cannot be connected between edges, so it will be a collection of faces, resulting in a solid body Can not form.

[0046] Therefore, in step S4, since the edge 21 and the surface 22 are in line contact, the distance between them is Om Although it is m, by adding an arbitrary numerical value to the distance and recognizing that it is separated without correcting the shape of this part, the shape is prevented from being broken after data conversion. Arbitrary numerical values are larger than the tolerance value (model allowable value) set by each CAD. For example, if the tolerance value is 0.0 OOlmm, the arbitrary numerical value is set to 0.01 mm.

[0047] The upper limit of an arbitrary numerical value is preferably set as follows. In order to avoid non-manifold defects, any numerical value must be set to a value greater than the tolerance value. In addition, as a shape (dimension) required by a general designer, the distance between the parts at the hem bend or 90 degree bend is allowed to be 0.1 mm or less. In addition, when processing products such as actual devices based on the 3D model, if the distance between the parts at the hem bend or 90 degree bend is 0.1 mm or less, processing problems will occur. do not do. Therefore, in step S4, it is sufficient to obtain an arbitrary numerical value satisfying the following relationship when automatically calculating an optimal numerical value of the tolerance value.

(Tolerance value (mm)) <(arbitrary numerical value (mm)) ≤ 0.1 (mm)

An arbitrary numerical value is set in advance so as to satisfy the above relationship, even if a predetermined numerical value is read out from a lookup table stored in the memory unit 202 or the like based on the tolerance value. May be stored. In the latter case, steps S3 and S4 can be omitted, and step S5 can be performed by automatically assigning a preset arbitrary value to the part corresponding to the non-manifold! ,.

[0048] Even for non-manifolds that are defective on the 3D model as described above, the shape is corrected in terms of the convenience of dropping into 2D drawings and the realization of products such as real devices. I do not want to do it. However, if 3D CAD data is subjected to data conversion processing and converted to an intermediate file, the shape may be damaged. Therefore, in order to solve this contradiction, in this example, the shape is not changed, and an arbitrary numerical value is assigned to the internal data only as internal data, and the non-manifold part is also a finite distance. By recognizing that it is separated by (arbitrary numerical value)! / Cutter, the trouble at the time of data conversion processing is solved. When converting 3D CAD data to an intermediate file for other tools as in the past, data with non-manifold defects will be processed to correct the 3D model because the shape will be broken on the receiver side. As a result, the development process becomes complicated and takes a long time. The number of man-hours can be reduced.

Industrial applicability

[0049] The present invention is applicable when converting 3D CAD data into various intermediate data by data conversion processing.

[0050] Although the present invention has been described with reference to the embodiments, it goes without saying that the present invention is not limited to the above-described embodiments, and various modifications and improvements can be made within the scope of the present invention.

Claims

The scope of the claims

[1] A 3D CAD data conversion method for converting 3D CAD data into a standard intermediate file by data conversion processing.

The 3D CAD data force automatically detects non-manifold parts,

Arbitrary line data or point contact of the non-manifold has an internal data of (tolerance value (mm)) (arbitrary numerical value (mm)) ≤ (larger than tolerance value). A three-dimensional CAD data conversion method, characterized in that a numerical value is given and the data conversion process is performed.

[2] The CAD data conversion method according to claim 1, wherein an upper limit is set for a numerical value larger than the tolerance value.

[3] The CAD data conversion method according to claim 2, wherein the upper limit is 0.1 (mm).

[4] The three-dimensional CAD data conversion method according to any one of claims 1 to 3, wherein the arbitrary numerical value is set in advance.

5. The three-dimensional CAD data conversion method according to claim 1, wherein the arbitrary numerical value is obtained based on the tolerance value.

6. The 3D CAD data conversion method according to any one of claims 1 to 3, wherein the tolerance value is 0.00 lmm.

[7] A 3D CAD data conversion device that converts 3D CAD data into a standard intermediate file by data conversion processing.

Means for automatically detecting non-manifold parts from the 3D CAD data;

Arbitrary line data or point contact of the non-manifold has an internal data of (tolerance value (mm)) (arbitrary numerical value (mm)) ≤ (larger than tolerance value). A three-dimensional CAD data conversion device comprising a means for applying a numerical value and performing the data conversion process.

8. The CAD data conversion device according to claim 7, wherein an upper limit is set for a numerical value larger than the tolerance value.

9. The CAD data conversion according to claim 8, wherein the upper limit is 0.1 (mm). apparatus.

10. The three-dimensional CAD data conversion method according to claim 7, wherein the arbitrary numerical value is set in advance.

[11] The three-dimensional CAD data conversion device according to any one of claims 7 to 9, wherein the arbitrary numerical value is obtained based on the tolerance value.

12. The three-dimensional CAD data conversion device according to any one of claims 7 to 9, wherein the tolerance value is 0.00 lmm.

[13] A program that allows a computer to convert 3D CAD data into a standard intermediate file using data conversion processing.

A procedure for causing the computer to automatically detect a part of the 3D CAD data force non-manifold;

In the computer, the relationship between the line contact or point contact of the non-manifold is (tolerance value (mm)) (arbitrary numerical value (mm)) ≤ (a value greater than the tolerance value). A program characterized by including a procedure for performing the data conversion processing after assigning an arbitrary numerical value satisfying the relationship.

14. The program according to claim 13, wherein an upper limit is set for a numerical value larger than the tolerance value.

15. The program according to claim 14, wherein the upper limit is 0.1 (mm).

[16] The program according to any one of claims 13 to 15, wherein the arbitrary numerical value is set in advance.

17. The program according to any one of claims 13 to 15, wherein the arbitrary numerical value is obtained based on the tolerance value.

18. The program according to any one of claims 13 to 15, wherein the tolerance value is 0.00 lmm.

[19] A computer-readable storage medium, wherein the program according to any one of claims 13 to 18 is stored.