JP2001147950A - Method and device for preparing article form data - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a device for preparing article form data and a producing method for product, with which the final form data of an article suitably reflected with the result of CAE analysis can be easily prepared. SOLUTION: CAD data, with which a product form is defined, are prepared and on the basis of these prepared CAD data, form data for CAE analysis are prepared. Then, CAE analysis is executed while using the prepared form data for CAE and on the basis of the result of the CAE analysis, the change of the product form is determined. When it is judged the change of the product form is required, the form data for CAE are changed, the CAD data are automatically changed corresponding to the change of the form data for CAE, and the product is produced on the basis of the CAD data, with which the finally determined form of the product is defined.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for creating article shape data and a method for manufacturing a product.

[0002]

2. Description of the Related Art Conventionally, CAE analysis such as flow analysis and structural analysis is performed using CAE shape data created from CAD data, and a shape satisfying required formability or strength is examined. When reflecting the shape determined to be appropriate to the CAD data, the operator refers to the CAE shape data, determines which part of the CAD data needs to be corrected and changed, and manually updates the CAD data. Was changing and creating the final product shape. Generally, it is the designer who enters the CAD data that defines the product's shape,
In many cases, the person who handles CAD data and the person who handles CAE shape data are different from each other, such as an analysis engineer who performs CAE analysis using data.
In order to perform CAE analysis based on the data and create an appropriate shape and then apply it to the CAD data, it is necessary for the analysis engineer to explain the changes to the designer and make changes to the CAD data. there were.

In recent years, in addition to a CAD shape input function, a CAE shape data creation function and a CAE analysis function have been provided, so that the degree of aptitude of the currently defined CAD shape in terms of formability and strength can be relatively easily examined. Some CAD systems are designed so that the designer changes the CAD data, creates CAE shape data each time, and performs a CAE analysis using the CAE shape data to examine the appropriate shape. Has become available as a system.

[0004]

However, at present, there is a large part that relies on an analysis engineer to make an accurate change to the shape change from the CAE analysis result.
In order to reflect the shape data for CAE that the analysis engineer has judged appropriate in terms of moldability and strength to CAD data, the analysis engineer explains and instructs the designer to make changes and creates CAD data Or, an analysis engineer had to learn how to operate a CAD system.

SUMMARY OF THE INVENTION The present invention has been made in view of the above situation, and provides an article shape data creating method and apparatus which can easily create final article shape data in which the results of CAE analysis are appropriately reflected. The purpose of the present invention is to provide a manufacturing method.

[0006]

According to the present invention, there is provided a CAE shape data creating step of creating shape data for CAE analysis based on CAD data defining an article shape. A CAE analysis step of performing a CAE analysis using the obtained CAE shape data, a shape change determination step of determining a change in an article shape based on the result of the CAE analysis, and an article shape in the shape change determination step. When it is determined that the change is necessary, the CAE shape data changing step of changing the CAE shape data, and in response to the change of the CAE shape data in the CAE shape data changing step, automatically. And a CAD data changing step of changing the CAD data.

[0007] According to another aspect of the present invention, the CA
In the E shape data creation step, attribute data representing the dependency of each CAE shape data on the CAD data is created, and the CAD data is changed based on the attribute data in the CAD data change step. An article shape data creation method according to claim 1 is provided.

According to another aspect of the present invention, the CA
In the D data change step, by creating difference data with respect to the shape data before change of the CAE shape data changed in the CAE shape data change step, by performing an addition / subtraction operation based on the created difference data. , The CAD
An article shape data creating method according to claim 1 or 2, wherein data is changed.

According to another aspect of the present invention, the CA
4. The method according to claim 3, wherein each of the changed portions in the E shape data changing step is grouped for each change operation to be created and used as difference data.

According to another aspect of the present invention, CAE shape data creating means for creating shape data for CAE analysis based on CAD data defining an article shape, and the created CAE shape data CAE analysis means for performing a CAE analysis using the, based on the result of the CAE analysis, a shape change determination means for determining the change of the article shape, and the shape change determination means determined that the change of the article shape is necessary The CAE shape data changing means for changing the CAE shape data, and the CAE by the CAE shape data changing means.
An article shape data creating apparatus is provided, which has a CAD data changing means for automatically changing the CAD data in response to a change in the use shape data.

According to another aspect of the present invention, CAD data defining a product shape is created, and shape data for CAE analysis is created based on the created CAD data. Perform CAE analysis using the shape data,
Based on the results of the CAE analysis, determine the product shape change,
When it is determined that the product shape needs to be changed, the CAE shape data is changed, and in response to the change in the CAE shape data, the CAD data is automatically changed, and the final product is determined. A method for manufacturing a product based on CAD data defining the shape of the product.

According to another aspect of the present invention, there is provided a computer-readable storage medium storing a computer program for executing each step of the article shape data creating method according to any one of claims 1 to 4 using a computer. A possible storage medium is provided.

The terms are defined below.

In the present invention, "CAD data" refers to data of shape data of an article input by a CAD system running on a computer. Examples of the format include an IGES format, a STEP format, and a Parasolid format.

In the present invention, “CAE analysis” refers to simulations such as flow analysis, thermal analysis, and structural analysis using a computer.

In the present invention, “CAE shape data” refers to shape data used for CAE analysis, and is often described by nodes, elements, element properties, material properties, and the like. For example, it includes data called “mesh data”, “finite element data”, “boundary element data”, and the like.

In the present invention, “attribute data” means a point describing a position in CAD data,
It also refers to data such as a curve describing a curve, a surface describing a curved surface, and a solid describing a solid.

In the present invention, "difference data" refers to the shape data of a portion where the position of a node or the number of nodes / elements is changed by comparing the shape data for CAE before and after the change.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a method and an apparatus for creating article shape data and a method for manufacturing a product will be described with reference to the accompanying drawings.

FIG. 1 is a block diagram showing an embodiment of an article shape data creating apparatus according to the present invention. In this embodiment, (100) is a computer, (101) is a keyboard, (102) is a mouse, (103) is a display, and (104) is an auxiliary storage device. For (104), a removable auxiliary storage device such as an MO, PD, or DVD can be used in addition to a hard disk device.

The auxiliary storage device includes a CAD data storage means (105) and a shape data storage means for CAE (106).

The computer (100) has a CAD data creating means (107) and a CAE shape data creating means (10).
8), CAE analysis means (109), shape change determination means (1)
10), CAE shape data changing means (111), and CAD data changing means (112).

FIG. 2 shows a flowchart of the first embodiment of the present invention. CAE shape data creation means (108)
Reads the CAD data, which is the product shape created by the CAD data creation means (107), in step 201, and uses it in step 202 for CAE analysis such as flow analysis and structural analysis.
Create shape data for CAE. Next, step 203
Using the CAE shape data created by the E shape data creation means (108), analysis such as flow analysis and structural analysis is executed by the CAE analysis means (109). In step 204, the CAE analysis result is read, and it is determined whether or not the shape should be changed by the shape change determination means (110). In the shape change determination means, the operator may make a determination while looking at the result, or may make a determination criterion in a database and compare the analysis result with the criterion to determine whether the shape change is necessary. . For example, when it is desired to make the shear rate at the time of flow less than a certain value, a flow analysis is executed, and the maximum shear rate generated as a result and its location are referred to. If the thickness at the place where the shear rate is generated is increased, the flow resistance is reduced and the shear rate can be reduced, so it is determined that it is necessary to change the thickness. May be automatically performed, or a message to that effect may be displayed on the display (103) to receive the judgment of the operator. Steps
If it is determined in 204 that the shape needs to be changed, step 205
Changes the shape by the CAE shape data changing means (111). When changing the shape, the operator may input the changed shape, or the relationship between the CAE analysis result and the shape change may be set as a rule so that the shape can be changed automatically. When automatically changing the shape data for CAE, the element size of the shape data for CAE
The determination can be made by referring to the node position, element size, and the like of the use shape data. Then, in step 203, CAE analysis is performed again using the changed CAE shape data, and step 204
The result of the CAE analysis is determined in step, and steps 203 to 205 are repeated until there is no need to change the shape. If the result of the analysis in step 204 is passed, step 206 compares the CAE shape data before the change with the final CAE shape data, recognizes the changed portion, and converts the changed portion into CAD.
Import the data and automatically change the shape to become the final CAE shape data.

Also, as in the second embodiment of the present invention shown in FIG. 3, steps 305 and 306 are executed each time the contents need to be changed in the analysis result determination step of step 304, and the changed points are determined. When the result is reflected in step 301 and steps 301 to 306 are repeated, and the analysis result determination in step 304 passes, step 307 converts the CAD data to the final CAD
It may be data. In this case, in the process of creating the CAE shape data from the CAD data in step 302, it may be necessary to specify the element size each time, but even in that case, the element division information such as the previously executed element size may be required. Is stored, the shape data for CAE can be automatically created, so that steps 302 to 307 can be automated.

Next, a method of reflecting the data in the CAD data in steps 206 and 306 will be described in detail. The first reflection method is that, when creating the CAE shape data in steps 202 and 303, the CAD data attributes are given to the CAE shape data, and there is a change when the CAE shape data is changed. By searching for the attributes of the CAD data of the part, specifying the degree of change, and modifying the CAD data in a form that matches the degree, the final CAE shape data is reflected on the CAD data.
Hereinafter, a specific description will be given with reference to FIGS.

FIG. 4 shows points P1 to P8, curves C1 to 12, and a curved surface.
FIG. 5 shows an example of CAE shape data created from the CAD data shown in FIG. 4, which is composed of 48 nodes and 18 elements. .
FIG. 6 shows a description example of a node which is CAE shape data in which CAD attributes are described. Conventionally, CAE shape data created from CAD data includes node information such as node ID numbers and coordinate positions, element numbers and node IDs that constitute elements.
Element information such as numbers and shape properties (for one-dimensional and two-dimensional, cross-sectional information etc.) and material properties related to material data are described, and there is no direct description of the relationship with CAD data. In the embodiment, at the time of creating the CAE shape data in step 202, the original point, the curve, or the surface on which the CAD data is a point, a curve, or a node, which is the CAE shape data created on the curved surface, Is described together with the attribute information on the CAD data. If the nodes are not necessarily on the points, curves or surfaces of the CAD data as in the invention described in JP-A-10-255077, the created CA
Judged that the points on the ridge line of the E shape data and the nodes on the outer surface were present on the points, curves, and curved surfaces that were in the closest geometrical positional relationship on the CAD data. Attribute information may be given.

FIG. 7 shows nodes (N2, N5, N8, N11) and (N3, N6,
N9.N12) is the CAE shape data that you want to reflect in the CAD data whose shape has been changed by moving 1mm and 2mm in the Z direction, respectively.
In order to reflect the CAE shape data of FIG. 7 on CAD data, first, a changed node is extracted. And
A search is performed to find out which CAD attribute the changed node had, to identify an attribute that needs to be changed as CAD data, and to predict the degree. In this case, the CAD attributes that need to be changed are P2 and P3 for points and C1, C2, C3,
At C6 and C7, it is specified that the curved surfaces are F1, F2, F3 and F4. Next, by changing the points, you identify whether there is a curve or surface where the equation changes, and if you need to change it,
The curve surface is approximated from the node group having the attribute of the curve that needs to be changed by approximating the curve equation by a method such as least squares, and the curve approximation formula is taken into consideration from the node group having the attribute of the surface that needs to be changed. Find the equation by the least squares method.

In this case, the curves are C1, C2, C3,
Since it can be recognized that it is sufficient to change only F1 on the surface, first the nodes with the attributes of the changed points P2 and P3
Considering N3 and N12 preferentially, the nodes on the curves C1, C2 and C3 (N
From (1, N2, N3) (N3, N6, N9, N12) and (N10, N11, N12), find the curves C1 ', C2', C3 'after the change. Then, the changed surface F1 'is obtained from the node groups N1 to N12 on the surface F1, and is automatically reflected on the CAD data.

Next, another method will be described.

When a node or element of the CAE shape data is added or deleted, the CAE shape data before and after the shape change is compared, and difference data is created. Method 1 for creating difference data
An example is given below. Searches for information on nodes on the outer surface of the CAE shape data after the shape has been changed, and recognizes that nodes or elements of the CAE shape data have been added or deleted if no CAD data attributes are given it can. In other words, the original
According to the shape data for CAE, when a node existing on the surface exists but is inside, it can be determined that the node or element has been added, and when it does not exist, it can be determined that the node or element has been deleted. Difference data can be created by comparing the shape of the added / deleted element with the original CAE shape data and the final CAE shape data as described above, so read this difference data onto CAD data, By performing the addition / subtraction operation, the final CAE shape data is reflected in the CAD data.

FIG. 9 shows final CAE shape data obtained by changing the CAE shape data shown in FIG. As described above, FIG.
By comparing the data of FIG. 10 with the data of FIG. 9, it can be seen that the shape shown in FIG. 10 has been deleted.
The CAD data shown in FIG. 11 can be automatically obtained by reading the shape data shown in FIG.

When changing nodes and elements, correction operation information is stored in the nodes and elements to be changed, and this data is read into the original CAD data as shape data of the changed portion, that is, difference data. The CAE shape may be reflected in the CAD data by performing a shape addition / subtraction operation on the CAD data in consideration of the change operation information indicating whether the addition / deletion has been performed. Also, the added / deleted elements may be grouped for each change operation and stored.

As described above, the difference between the geometric shapes may be obtained independently of the addition / deletion of nodes or elements of the CAE shape data, and the CAD data may be corrected based on the difference.

The CAD data may be modified by combining the above-described second method with the first method.

In this way, by automatically reflecting the changed point of the CAE shape data created from the CAD data to the CAD data, the CAD data of the product satisfying the appropriate specifications reflecting the analysis result is created. Can be easily performed. This C
Producing a product based on AD data makes it possible to produce a properly designed product easily and quickly.

As described above, the above embodiment is implemented by a computer and a program including a CAD for operating the computer. Such programs and data of various storage means are distributed through computer-readable tangible media such as floppy disks, MOs, and CD-ROMs, and transmission means such as a wired or wireless network.

[0037]

According to the present invention, the flow / structure analysis is performed using the CAE shape data created from the CAD data, and the moldability / strength requirements are satisfied while changing the CAE shape data. The shape to be determined is examined, and the finally determined shape is automatically reflected in the CAD data, so that the efficiency of product design can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is a flowchart of an embodiment of the present invention.

FIG. 3 is a flowchart of an embodiment of the present invention.

FIG. 4 is a diagram of CAD data.

FIG. 5 is a diagram of CAE shape data created from the CAD data of FIG. 3;

6 is a CAE in which attributes of the CAE shape data in FIG. 4 are described.
This is the use shape data.

FIG. 7 is a diagram of CAE shape data whose shape has been changed;

FIG. 8 is a diagram of CAD data created from the CAE shape data of FIG. 6;

FIG. 9 is a diagram of CAE shape data after FIG. 4 is changed.

FIG. 10 is a diagram of CAE shape data changed from FIG. 4;

FIG. 11 is a diagram of CAD data obtained by adding and subtracting the changed points in FIG. 9;

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 computer 101 keyboard 102 mouse 103 display 104 auxiliary storage device 105 CAD data storage means 106 shape data storage means for CAE 107 CAD data creation means 108 shape data creation means for CAE 109 CAE analysis means 110 shape change determination means 111 shape data for CAE Change means 112 CAD data change means

Claims (7)

[Claims] 1. C based on CAD data defining an article shape
CAE shape data creation step of creating shape data for AE analysis, CAE analysis step of performing CAE analysis using the created CAE shape data, based on the result of the CAE analysis, based on the result of the CAE analysis, A shape change determination step of determining a change,
The CAE for changing the CAE shape data when it is determined in the shape change determination step that the change of the article shape is necessary.
An article shape, comprising: a shape data changing step for use; and a CAD data changing step for automatically changing the CAD data in response to the change of the CAE shape data in the CAE shape data changing step. Data creation method. 2. In the CAE shape data creating step,
2. The article according to claim 1, wherein attribute data representing dependency of each of the CAE shape data on the CAD data is created, and the CAD data is changed based on the attribute data in the CAD data changing step. How to create shape data. 3. The method according to claim 2, wherein in the CAD data changing step, the CAE
Modifying the CAD data by creating difference data with respect to the pre-change shape data of the CAE shape data changed in the process of changing the shape data for CAE, and performing an addition / subtraction operation based on the created difference data. The article shape data creating method according to claim 1 or 2, wherein: 4. The article shape data creating method according to claim 3, wherein each changed portion in the CAE shape data changing step is created by grouping by change operation and used as difference data. 5. C based on CAD data defining the article shape
CAE shape data creating means for creating shape data for AE analysis, CAE analyzing means for performing CAE analysis using the created CAE shape data, and, based on the result of the CAE analysis, Shape change determining means for determining a change,
CAE for changing the CAE shape data when the shape change determination means determines that the article shape needs to be changed.
Object shape data changing means and CAD data changing means for automatically changing the CAD data in response to the change of the CAE shape data by the CAE shape data changing means. Data creation device. 6. Creating CAD data defining a product shape,
Create shape data for CAE analysis based on the created CAD data, CAE using the created CAE shape data
Perform the analysis, based on the result of the CAE analysis, determine the change of the product shape, if it is determined that the product shape change is necessary, change the CAE shape data, the CAE shape data of the A method for manufacturing a product, wherein the CAD data is automatically changed in response to the change, and the product is manufactured based on the CAD data defining the shape of the product finally determined. 7. A computer-readable storage medium storing a computer program for executing each step of the article shape data creating method according to claim 1 using a computer.