JP3349916B2 - Shape data verification method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a shape data verification method for verifying shape data of a product using a CAD system.

[0002]

2. Description of the Related Art Conventionally, vehicle body shape data has been created as follows. In other words, a mockup is created using resin or clay, and the shape is judged by the body designer by sensibility and sensory evaluation.Based on the above judgment result, the shape is modified as necessary, and then the mockup is made. The shape data was created by three-dimensionally scanning the external shape of the device with a scanning machine.

[0003] However, this method requires a large number of man-hours, takes a considerable amount of time for processing, and has a problem that the quality of finally obtained shape data varies due to individual differences among vehicle body designers. was there.

On the other hand, with the remarkable progress of computer technology, recently, it has become possible to construct a mock-up on a CAD system and display an image of a vehicle body on a display to evaluate or correct the design. . For example, the degree of undulation of a displayed design line is obtained by a curvature calculation, and the calculation result is displayed using a line segment or the like corresponding to the magnitude of the curvature to evaluate the quality of the design. is there. Then, based on the evaluation result, the design can be modified as needed. It should be noted that shape data for processing a mold is created from the design modified as described above, and that each part constituting the vehicle body is manufactured using the mold created based on the shape data. become.

[0005]

By the way, even if the curvature is displayed as described above, it is extremely difficult to immediately judge from the size thereof whether or not there is a requirement or condition leading to die machining production. is there.

[0006] Even if it is possible to judge, CA
The design data supplied to the D system takes into account the detailed structure of the product to be actually manufactured, the material properties of the product, or the shape restrictions based on the mold structure for manufacturing the product. Therefore, if the evaluation is performed using only the curvature information obtained only from the design data, the following problem occurs.

FIGS. 7A to 7D show the shape of the design surface of the hood 2 prepared by the vehicle body designer and the cross-sectional shape of each part thereof. In this case, in the shape of the design surface shown in FIG. 7A, only the portions indicated by arrows in FIGS. 7B to 7D are represented. On the other hand, the shape of the bent rib surface shown in FIGS. 7B to 7D is added to the shape data for manufacturing an actual product. Therefore, for example, when a design surface and a rib surface added thereto are formed using a mold, a part of the design surface close to the rib surface may be deformed in accordance with the formation of the rib surface.

For example, in the case of the hood 2, since the area of the flat portion is considerably large, the surface of an actual product may be deformed by its own weight. Therefore,
If a mold is created faithfully with respect to design data, a product manufactured by the mold may not have a desired design.

Further, there are cases where it is technically difficult to manufacture a product as designed, due to restrictions on the structure of the mold.

As described above, it is difficult to make a substantial evaluation of a design without considering production technology requirements for manufacturing parts.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and has as its object to provide a shape data verification method which can verify the quality of product shape data very easily and reliably. .

[0012]

A shape data verifying method according to the present invention is a shape data verifying method for verifying shape data of a designed product using a CAD system, wherein the shape data verifying method is configured by the shape data. A step of specifying an arbitrary curve on the shape surface of the product, and a step of calculating the curvature of the specified curve at a predetermined sampling pitch,
The respective curvatures are determined based on production technology requirement data of the product.
Compare with the cutoff reference value to determine whether it is within the allowable range
Process and the determined line segment of a length corresponding to the size of each curvature, along with the table Shimesuru along said curve the line segment from the center of curvature of the line segment, the formation of the determination of the curvature
Displaying the respective line segments in a specific color or the like based on the result ,
And verifying the shape data based on the displayed line segment.

[0013]

FIG. 1 shows a CAD system 10 to which a shape data verification method according to the present invention is applied. The CAD system 10 includes a design data storage device 12 for storing design data of the vehicle body, a production technology requirement data storage device 14 for storing production technology requirement data for manufacturing the vehicle body, and a shape data of the vehicle body based on the design data. And a shape data verification device 16 for performing the verification.

The design data storage device 12 stores design data which is a surface model including surface information created on the upstream according to the design information of the vehicle body.
The production technology requirement data storage device 14 includes a rib surface shape corresponding to a part of the product added to the design data, material properties including the weight of the product manufactured based on the design data, and the like. Production technology requirement data for designating conditions due to restrictions on the structure of the mold to be performed.

The shape data verification device 16 includes an interface circuit 18, a control circuit 20, and a processing circuit 22. The interface circuit 18 includes a display 24,
A keyboard 26, a mouse 28, and a storage circuit 30 for storing work data are connected, and a design data storage device 12 and a production technology requirement data storage device 14 are connected. The control circuit 20 controls the overall operation of the shape data verification device 16. The processing circuit 22 has a function of creating shape data in which rib data relating to a rib surface is added to design data, displaying a three-dimensional shape of a body part based on the shape data, and performing various verification processes. Prepare.

That is, the processing circuit 22 includes a shape data creation unit 32, a curve curvature analysis unit 34, and a curved surface curvature analysis unit 3.
6, a cross-section analysis unit 38, a distance analysis unit 40, an angle analysis unit 42, and an image analysis unit 44.

As shown in FIG. 2, the shape data generator 32 sets the rib surface 46 on the design surface 6 constituted by the design data based on the production technology requirement data, thereby representing the complete shape surface 48. Create shape data.

The curve curvature analyzer 34 calculates the curvature of an arbitrary curve on the complete shape surface 48 or the design surface 6 and analyzes whether or not the curvature is within a predetermined range. Pass / fail judgment is made.

The curved surface curvature analyzing section 36 obtains the curvature of the shape surface at an arbitrary portion of the perfect shape surface 48 or the design surface 6 and analyzes the unevenness of the surface from the curvature.
The quality of the shape data is determined.

The cross-section analysis unit 38 calculates a cross-sectional shape of the perfect shape surface 48 or an arbitrary portion of the design surface 6,
By analyzing the shape, the quality of the cross section is determined.

The distance analysis unit 40 determines the quality of the perfect shape surface 48 by analyzing the width and the level difference between adjacent perfect shape surfaces 48 when the three-dimensional shape of the vehicle body is viewed from an arbitrary direction. .

The angle analysis unit 42 determines the bonding state of the surfaces such as irregularities by obtaining and analyzing the bonding angle between the surfaces constituting the perfect shape surface 48 or the design surface 6.

The image analyzing unit 44 displays the three-dimensional shape of the vehicle body as viewed from an arbitrary direction according to the shape data created by the shape data creating unit 32.
In addition, the pass / fail determination data obtained by the curve curvature analysis unit 34, the curved surface curvature analysis unit 36, the distance analysis unit 40, and the angle analysis unit 42 are displayed in order to perform desired analysis.

Next, a description will be given of a shape data verification method of the present embodiment using the CAD system 10 configured as described above.

The control circuit 20 constituting the shape data verification device 16 reads the design data from the design data storage device 12 via the interface circuit 18 and stores it in the storage circuit 30. In addition, this design data
As shown in FIG. 2A, it is configured by data representing only the design surface 6.

As shown in FIG. 2B, the shape data creating unit 32 constituting the processing circuit 22
Of the design surface 7 is created by performing a process of turning the corner portion into an arc shape. After the design surface 7 whose corner portion has an arc shape is set, the rib surface 46 is set as shown in FIG. This rib surface 46
According to the production technology requirement data supplied from the production technology requirement data storage device 14, for example, it is set as shown in FIGS. 7B to 7D. After the rib surface 46 is set, a surface loop is defined for the new design surface 8 and the new rib surface 46, and the shape data forming the complete shape surface 48 shown in FIG. 2D is created.

Next, based on the shape data, the image analysis unit 44 displays a three-dimensional design image of the vehicle body and necessary data in a desired form on the display 24 in consideration of the production technology requirement data. The operator verifies the quality of the design data from the three-dimensional design image, and issues a design data correction instruction or the like as necessary.

A method of verifying the shape data by the curve curvature analyzing unit 34 will be described with reference to the flowchart shown in FIG.

First, the operator sets a judgment criterion value, which is an allowable range of curvature of an arbitrary curve on the completely-shaped surface 48 or the shape surface as the design surface 6 obtained as described later, in the production technical requirement data. It is set on the basis of (Step S1).

The criterion value is, for example, assuming that the shape desired to be finally obtained is a plane in consideration of the own weight of the components constituting the shape surface, and the design surface for this shape surface is convex by a predetermined amount. Since the shape needs to be formed, the curvature corresponding to the predetermined amount is set based on the production technology requirement data. In addition, for a part that needs to consider the maximum value of the curvature that can be manufactured by the mold, the maximum value based on the production technology requirement data is set as a determination reference value.

After setting the determination reference value for the curvature as described above, it is determined whether or not there is data to be verified (step S2), and if so, the verification parts such as the hood, roof, fender and the like are set. (Step S3)
An analysis process is performed (Step S4).

That is, in the analysis processing, as shown in FIGS. 4A and 4B, a desired curve L on the selected shape surface is obtained.
1 or L2, and a verification point P is set on the curve L1 or L2 at a predetermined sampling pitch. Then, the curvature of the curve L1 or L2 is obtained for each verification point P. Next, it is determined whether or not each curvature is within an allowable range by comparing each of the curvatures with the determination reference value (step S5). FIG. 5 shows the verification result at each verification point P based on the above-described determination in relation to the target data name, the analysis function, the determination reference value, and the number of an analysis image diagram described later. , Are stored in the storage circuit 30.

On the other hand, a line segment M having a length corresponding to the size is obtained from the curvature, a color corresponding to the value is set, and an analysis image diagram for display is created (step S6).

The above-described analysis processing and analysis image diagram creation processing are performed on desired verification items set by the operator (step S7).

After the processing for each verification item is completed as described above, the specified analysis image diagram is displayed on the display 24 (step S8).

FIG. 6 is an analysis image diagram obtained by analysis by the curve curvature analysis unit 34. In this analysis image diagram, for a desired curve 51 of the selected shape surface 50, a line segment M having a calculated length is displayed in a color (line type in FIG. 6) corresponding to the length. ) Is displayed in the center direction of the curvature, and the value of the curvature represented by each color is displayed as a scale 52. In this case, the operator can very easily verify the degree of bending of the curve 51 from the displayed color. As a method other than the color-coded display, it is possible to add a line type or a marker, display by gradation, display by numerical value itself, and the like.

As is generally known, the changing point of the curve 51 and its degree can be easily grasped.
Further, as shown in FIG. 4A, it can be understood that the curve L1 changes from a convex shape to a concave shape at the verification point P1 where the direction in which the line segment M is drawn changes. Furthermore, as shown in FIG. 4B, since the line segment M intersects at the verification point P2, it can be known that the curve L2 is bent at the verification point P2.

In the present embodiment, the line segment M is not limited to the length, but corresponds to an attribute value, for example, a radius of curvature, a center direction, and the like. By setting the criterion value indicating the allowable range, it is possible to immediately determine, for example, that the curvature exceeds the design allowable range at the portion where the solid line changes from the solid line to the dotted line in FIG.

As another analysis process, for example, the curved surface curvature analyzing section 36 computes the curvature of a desired curved portion constituting the three-dimensional design image, and displays the computation result on the display 24 on the display 24. Display with The operator can determine the quality of the unevenness of the curved surface based on the display. Also, the cross-section analysis unit 38
A cross-sectional shape of a desired portion constituting the three-dimensional design image is obtained, and the shape is displayed on the display 24. The operator can determine the quality of the sectional shape based on the display. The distance analysis unit 40 calculates a width and a step between adjacent perfect-shaped surfaces 48 when the three-dimensional design image is viewed from an arbitrary direction, and compares the calculation result with the three-dimensional design image on the display 24. Display them in layers. The operator can determine the quality of the width or the step based on the display. The angle analysis unit 42 calculates a joint angle between the surfaces forming the perfect shape surface 48 or the design surface 6 and displays the calculation result in a manner superimposed on the three-dimensional design image on the display 24. The operator can determine a defect such as a broken surface based on the display.

[0040]

As described above, according to the shape data verification method according to the present invention, the curvature of an arbitrary curve on a shape surface is displayed in different colors in accordance with the value. It can be easily grasped. Further, the curvature is compared with a criterion value set based on the production technology requirement data of the vehicle body, and the shape data is verified based on the comparison result, so that a determination can be made in consideration of an actually manufactured product. . Therefore, the vehicle body can be manufactured extremely efficiently by correcting the shape data in advance as needed based on the determination result obtained in this way.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a CAD system to which a shape data verification method according to an embodiment is applied.

FIG. 2 is a schematic explanatory view of a procedure for setting a rib surface with respect to a design surface.

FIG. 3 is a flowchart of a shape data verification method according to the embodiment.

FIGS. 4A and 4B are explanatory diagrams of a state where a line segment corresponding to the curvature is set for a curve.

FIG. 5 is an explanatory diagram of a data table of an analysis result.

FIG. 6 is an explanatory diagram of a display screen of a curve curvature as an analysis result.

FIGS. 7A to 7D are explanatory views of the shape of a design surface and the cross-sectional shape of a rib added thereto.

[Explanation of symbols]

Reference Signs List 10 CAD system 12 Design data storage device 14 Production technology requirement data storage device 16 Shape data verification device 20 Control circuit 24 Display 32 Shape data creation unit 34 Curve curvature analysis unit 36 Curved surface curvature analysis unit 38 ... Section analysis section 40 ... Distance analysis section 42 ... Angle analysis section 44 ... Image analysis section

Continuation of the front page (56) References JP-A-5-89188 (JP, A) JP-A-5-66915 (JP, A) JP-A-8-22480 (JP, A) JP-A-5-89190 (JP, A) , A) JP-A-7-311783 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G06F 17/50 JICST file (JOIS)

Claims (1)

(57) [Claims] 1. A shape data verification method for verifying shape data of a designed product using a CAD system, comprising the steps of specifying an arbitrary curve on a shape surface of the product constituted by the shape data. Determining a curvature of the specified curve at a predetermined sampling pitch; and determining each curvature based on production technical requirement data of the product.
Compare with the cutoff reference value to determine whether it is within the allowable range
A step, the line segment of a length corresponding to the size of each curvature determined, the
Each line segment from the center of curvature of each line segment along the curve
With Table Shimesuru, based the on the result of the determination of the curvature
Displaying each line segment in a specific color or the like, and verifying the shape data based on the displayed line segment.