JP6153457B2 - Draw model generation method and draw model generation system - Google Patents

Description

  The present invention relates to a draw model generation method and a draw model generation system. Specifically, the present invention relates to a draw model generation method and a draw model generation system for generating a draw model for molding a press-formed product.

  Panel products such as outer panels and roof panels for automobiles are manufactured by pressing a single plate with a mold that has a desired product shape to form a press-molded product. Is formed by forming a flange portion or making a hole through which a bolt is inserted. In such a panel product, a production line is designed before a production process for actual production.

  Specifically, when the design design of the product shape is performed, a draw model of a press-formed product is generated from this design design, and the model shape is evaluated by CAE (Computer Aided Engineering), so that the designed shape is actually It is decided to check whether it can be pressed.

Here, the relationship between the product shape and the draw model will be described with reference to FIG. The draw model 9 includes a product portion 91 designed for a vehicle type, a surplus portion 93 that is assumed to be cut off, and a die face portion 95 that is assumed to be pressed when pressed with a mold. Consists of.
Since the product shape is obtained when the design design is made, the product portion 91 of the draw model 9 can be generated together with the design design. The die face portion 95 is basically a flat surface because it is assumed to be a heel presser, and can be generated relatively easily. On the other hand, since the surplus portion 93 is a portion that deforms in accordance with the press work, it takes much time to generate the surplus portion 93 in the generation of the draw model 9.

  Further, when the model shape evaluation by CAE is not good, it is necessary to repeat the correction of the surplus portion and the analysis by CAE, which takes a huge amount of time. Therefore, in recent years, a model design system is known that can design a draw model whose quality is guaranteed by CAE in a short time by selecting a cross section of the surplus portion from a predetermined template (Patent Document 1).

JP 2009-104456 A

  According to the model forming system of Patent Document 1, although it is possible to easily set the cross section of the surplus portion, it takes much time to generate the surface data from the setting of the cross section, and further improvement is required. It was.

  This invention is made in view of such a problem, and provides the draw model production | generation method and draw model production | generation system which can produce | generate the surface of a surplus part easily and immediately after the cross section setting of a surplus part. With the goal.

  The present invention relates to a draw model generation method for generating a draw model of a press-formed product including a surplus part formed around a product part from CAD data having a product part and a die face part, Generating a plane point group from a plurality of feature points defined by XY coordinates, setting a plurality of cross sections of the surplus portion between the product portion and the die face portion, and The step of projecting the plane point group, calculating the Z coordinate of the cross section that coincides with the XY coordinates of the feature points as the Z coordinates of the feature points, and connecting the feature points from which the XYZ coordinates are obtained by the step into a polygon And obtaining the surplus portion to generate a draw model of the press-formed product.

  Further, the step of calculating the Z coordinate of the feature point includes a step of determining whether or not the cross section exists at a position coinciding with the XY coordinate of the feature point, and the cross section when the cross section exists. A Z coordinate of the feature point as a Z coordinate of the feature point, and when the cross section does not exist, a candidate cross section is obtained from a plurality of cross sections, and the Z coordinate of the feature point is determined based on the obtained candidate cross section. And a calculating step.

  Further, the step of calculating the Z coordinate of the feature point based on the candidate cross section acquires two or more cross sections across an infinite straight line parallel to the Z direction passing through the feature point as candidate cross sections; Calculating a nearest point between the infinite line and each candidate cross section, obtaining a Z coordinate of the nearest point; and for each Z point of the nearest point, the infinite line and each nearest point And a step of calculating the Z coordinate of the feature point by performing weighting based on the distance to.

  The drawing model generation method of the present invention includes a step of setting a plurality of intermediate shape cross sections generated in the press working process of the product portion for the product portion, and the plane point with respect to the intermediate shape cross section. A step of projecting a group, calculating a Z coordinate of the cross section of the intermediate shape that coincides with an XY coordinate of the feature point as a Z coordinate of the feature point, and connecting the feature points from which the XYZ coordinate is obtained by the step And generating the draw model of the press-formed product by acquiring the intermediate shape.

  Further, the step of generating the plane point group may include arranging a plurality of feature points in a grid pattern at predetermined intervals.

  The present invention also includes a draw model generation system capable of executing the above-described draw model generation method.

  According to the present invention, the surface of the surplus portion can be obtained by polygon data, and a draw model including the surplus portion can be generated easily and quickly after setting the cross section of the surplus portion.

It is a figure which shows the outline | summary of a draw model production | generation system. It is a block diagram which shows the function structure of a draw model production | generation system. It is a figure which shows an example of the plane grating | lattice which has a some feature point. It is a figure which shows an example of the cross section set between a product part and a die face part. It is a figure which shows an example of the calculation method of the Z coordinate of the feature point projected on the surplus part. It is a figure which shows an example of the calculation method of the Z coordinate of the feature point projected on the product part. It is a flowchart which shows the flow of a process of a draw model production | generation system. It is a flowchart which shows the flow of a process of a draw model production | generation system. It is a figure which shows an example of the draw model which consists of a product part, a surplus part, and a die face part.

  Hereinafter, a preferred embodiment of a draw model generation system of the present invention will be described with reference to the drawings.

[Outline of draw model generation system]
First, the outline of the draw model generation system of the present invention will be described with reference to FIG. In the draw model generation system, a draw model 9 of a press-formed product is generated from a product part 91 and a die face part 95 generated using CAD (Computer Aided Design). Specifically, in the draw model generation system, as shown in FIG. 1B, each of the regions corresponding to the draw model 9 including the product portion 91 and the die face portion 95 is defined by individual XY coordinates. A planar grid 10 composed of a plurality of feature points 101 is projected. Then, as shown in FIG. 1C, the projected feature points 101 are connected to form a polygon 102, thereby generating a draw model 9.

At this time, as shown in FIG. 1A, since the shape of the product part 91 and the die face part 95 is defined in advance, the coordinates of the feature point 101 projected onto the product part 91 and the die face part 95 (Z (Coordinates) can be easily obtained. On the other hand, since the shape of the surplus portion 93 is not defined, the coordinates (Z coordinate) of the feature point 101 projected onto the surplus portion 93 cannot be acquired.
In this regard, in the draw model generation system of the present invention, the draw model 9 is generated by interpolating the coordinates (Z coordinate) of the feature point 101 projected on the surplus portion 93 by a method described later. Details will be described below.

[Draw model generation system configuration]
Then, with reference to FIG. 2, the structure of the draw model production | generation system 1 of this invention is demonstrated. FIG. 2 is a block diagram showing a functional configuration of the draw model generation system 1 according to an embodiment of the present invention.
The draw model generation system 1 includes an input device 2 through which an operator inputs various data and commands, an arithmetic device 4 that executes various arithmetic processes according to inputs from the input device 2, and a display device 6 that displays an image. And a storage device 8 for storing various data.

  The input device 2 includes hardware such as a keyboard and a mouse that can be operated by an operator. Data and commands input by operating the input device 2 are input to the arithmetic device 4.

  The display device 6 is configured by hardware such as a CRT or a liquid crystal display capable of displaying an image. For example, a three-dimensional image of a draw model is displayed on the display unit of the display device 6 as a processing result by the arithmetic device 4.

  The storage device 8 is configured by hardware such as a hard disk drive or a solid state drive, and stores CAD data including shape data of the product part 91 and shape data of the die face part 95 generated using CAD. The CAD data stored in the storage device 8 does not include the shape data of the surplus portion 93. Further, the storage device 8 stores plane grid data including data (XY coordinates) of feature points 101 constituting the plane grid 10. The storage device 8 also stores cross-sectional data including parameters that define the cross-sectional shape set in the surplus portion 93 or the like.

  The arithmetic device 4 is configured by hardware such as a CPU, and includes a plane lattice generation unit 41, a cross-section setting unit 42, a coordinate calculation unit 43, and a draw model generation unit 44 in cooperation with predetermined software. Consists of.

  The plane grid generator 41 generates the plane grid 10 shown in FIG. 3 in response to a command from the operator via the input device 2. The planar lattice 10 generated by the planar lattice generation unit 41 is stored in the storage device 8. The plane grid 10 may be stored in advance in the storage device 8 and read out from the storage device 8 as necessary, instead of being generated according to the operation of the operator.

Here, the planar grating 10 will be described with reference to FIG. As shown in FIG. 3A, the planar grid 10 is configured by arranging a plurality of feature points 101, each defined by individual XY coordinates, in a grid at predetermined intervals.
The interval between the feature points 101 can be arbitrarily set. However, when the draw model relates to a panel product such as an outer panel or a roof panel of an automobile, the interval is preferably set to 0.5 mm. This point will be specifically described with reference to FIGS. FIG. 3B is a schematic diagram showing a cross-sectional shape of the product portion 91, and FIG. 3C is a portion where the polygonal bending angle is the largest among panel products such as an outer panel and a roof panel of an automobile. It is a figure which shows the relationship between the space | interval of the feature point 101 in FIG.

As described above, in the draw model generation system 1 of the present invention, the plane grid 10 (feature point 101) is projected onto the product unit 91 and the like, and the Z coordinate of the feature point 101 is acquired. Here, the interval between the feature points 101 projected on the product part 91 varies depending on the inclination of the product part 91 with respect to the XY coordinates.
With reference to FIG. 3 (B), the product part 91 considers the cross-sectional shape comprised from the planes 911 and 913 substantially parallel to XY coordinate, and the inclined surface 912 inclined by predetermined angle with respect to XY coordinate. At this time, when the interval L1 between the feature points 101 projected onto the planes 911 and 913 is compared with the interval L2 between the feature points 101 projected onto the slope 912, the interval L2 becomes wider. The interval between the feature points 101 is a bending angle of the polygon 102 when the polygon 102 is acquired by connecting the feature points 101. If the bending angle of the polygon 102 is large, it causes an error in the model shape evaluation by CAE, so it is necessary to keep it within a range where no error occurs.
As shown in FIG. 3C, in the model shape evaluation by CAE, if the bending angle of the polygon 102 exceeds θmax, there is a problem such as an error or an incorrect solution. In this regard, in an automotive panel product, the polygon 102 has a bent angle of approximately θmax by setting the interval between the feature points 101 to 0.7 mm, and the polygon 102 has a bent angle by setting the interval between the feature points 101 to 0.5 mm. Was confirmed to be less than θmax. Therefore, when a draw model is generated for a panel product of an automobile, it is preferable to set the interval between the feature points 101 to 0.5 mm at a location where the shape change is large.
Note that θmax is an empirical threshold and is different for each CAE software.

  Returning to FIG. 2, the cross section setting unit 42 sets a plurality of cross sections in the surplus portion 93 in accordance with a command from the operator via the input device 2. The plurality of cross sections set by the cross section setting unit 42 are stored in the storage device 8 in association with parameters that define the shape of the cross section. In addition, the setting method of a cross section is arbitrary, For example, it is good also as an operator setting manually, and good also as setting using the cross-section template preset like the above-mentioned patent document 1. .

Here, with reference to FIG. 4, the cross section set to the surplus part 93 is demonstrated. As shown in FIG. 4A, the cross-section setting unit 42 includes a plurality of cross-sections 931A, 931B, and 931C (hereinafter, referred to as an extra portion 93 between the product part 91 and the die face part 95 where the shape data is generated). , Collectively referred to as “cross section 931”).
As shown in FIG. 4B, the cross section 931 is formed by connecting a plurality of straight lines and a plurality of curves, and is defined by a plurality of parameters indicating specific shapes of the respective straight lines and the respective curves. . The parameters that define the cross section 931 can include necessary information as appropriate, but at least include information capable of calculating XYZ coordinates at an arbitrary position on the cross section 931. In the present embodiment, as these parameters, parameters L1, L2, L3, L4 (mm) indicating the length of each straight line, parameters R1, R2, R3 (mm) indicating the curvature radius of each curve, and each curve Parameters A1, A2, A3 (deg) indicating wall angles and XYZ coordinates indicating the start position and end position of the cross section 931 are included.

Returning to FIG. 2, the coordinate calculation unit 43 projects the planar grid 10 on the CAD data, and calculates the Z coordinate on the CAD data that matches the XY coordinate of the feature point 101 as the Z coordinate of the feature point 101. Thereby, the Z coordinate is given to the feature point 101 arranged on the XY plane.
Here, the coordinate calculation unit 43 will be described in more detail with reference to FIG. FIG. 5A is a schematic diagram showing a cross-sectional shape of CAD data. With reference to FIG. 5A, since the shape data of the product portion 91 and the die face portion 95 is stored in the storage device 8 in advance, the feature points 101 projected on the product portion 91 and the die face portion 95 are displayed. The Z coordinate can be easily obtained from the shape data of the product part 91 and the die face part 95. On the other hand, since shape data is not set for the surplus portion 93, a device for appropriately acquiring the Z coordinate of the feature point 101 projected on the surplus portion 93 is required.
Returning to FIG. 2, the coordinate calculation unit 43 includes a determination unit 45, a first Z coordinate calculation unit 46, and a second Z coordinate calculation unit 47.

The determination unit 45 determines whether or not shape data is set at a position on the CAD data that matches the XY coordinates of the projected feature point 101. Here, even in the surplus portion 93, since the parameter for defining the cross section is set for the portion where the cross section 931 is set by the cross section setting section 42, the Z coordinate is projected when the feature point 101 is projected. Can be easily obtained. Therefore, whether or not the shape data is set is synonymous with determining whether or not the product portion 91, the die face portion 95, or the cross section 931 exists at a position that coincides with the XY coordinates of the feature point 101.
More specifically, the determination unit 45 determines whether or not the feature point 101 is projected on the CAD surface (the product unit 91 and the die face unit 95). Further, in the determination unit 45, an intermediate shape cross section 915 is set at a point Q having a cross-sectional area (a surplus portion 93 in which a cross-section 931 is set) and a difficult part Q in a product portion 91 to be described later. It is determined whether or not it has been projected within (position).

  The first Z coordinate calculation unit 46 functions when the product unit 91, the die face unit 95, or the cross section 931 exists at a position that coincides with the XY coordinates of the feature point 101, and the product unit 91, the die face unit 95, or the cross section. The Z coordinate of the feature point 101 is calculated based on the shape data 931 (cross-section parameters). Specifically, the first Z coordinate calculation unit 46 calculates, as the Z coordinate of the feature point 101, the Z coordinate of the product part 91, the die face part 95, or the cross section 931 at a position that coincides with the XY coordinate of the feature point 101. To do.

The second Z coordinate calculation unit 47 functions when the product part 91, the die face part 95, and the cross section 931 do not exist at a position that coincides with the XY coordinates of the feature point 101. From the shape around the feature point 101, The Z coordinate of the feature point 101 is calculated. The peripheral shape means an arbitrary position where the Z coordinate can be specified. For example, the product portion 91, the die face portion 95, or the cross-section 931 around an infinite straight line parallel to the Z direction passing through the feature point 101. Say.
The second Z coordinate calculation unit 47 includes a candidate cross section acquisition unit 471, a closest point acquisition unit 472, and a coordinate calculation unit 473.

  The candidate cross section acquisition unit 471 acquires two or more cross sections 931 across the infinite straight line that passes through the feature point 101 and is parallel to the Z direction as candidate cross sections. Note that two or more cross-sections straddling an infinite straight line mean two or more cross-sections in the vicinity of the infinite straight line. The closest point acquisition unit 472 calculates the closest point with respect to the infinite straight line passing through the feature point 101 for each of the acquired plurality of candidate cross sections, and acquires the Z coordinate of the closest point. The coordinate calculation unit 473 calculates the Z coordinate of the feature point 101 by weighting the Z coordinate of the nearest point on the candidate cross section based on the distance from the infinite line.

Here, an example of a Z coordinate calculation method by the second Z coordinate calculation unit 47 will be specifically described with reference to FIG. In FIG. 5B, a feature point 101A is a feature point where the product portion 91, the die face portion 95, and the cross section 931 do not exist in the corresponding XY coordinates.
First, the second Z coordinate calculation unit 47 (candidate section acquisition unit 471) sets an infinite straight line 103 that passes through the feature point 101A and is parallel to the Z direction. Then, two cross sections 931 that cross the infinite straight line 103 as viewed in the Z direction are acquired as candidate cross sections. In FIG. 5B, cross sections 931A and 931B are acquired as candidate cross sections.

  Subsequently, the second Z coordinate calculation unit 47 (nearest point acquisition unit 472) calculates the closest point with respect to the infinite straight line 103 for the cross sections 931A and 931B acquired as candidate cross sections, and acquires the Z coordinate of this closest point. . In FIG. 5B, the nearest point P1 is calculated for the cross section 931A, and the Z coordinate Z1 of the nearest point P1 is acquired. Further, the closest point P2 is calculated for the cross section 931B, and the Z coordinate Z2 of the closest point P2 is acquired.

Subsequently, the second Z coordinate calculation unit 47 (coordinate calculation unit 473) weights the Z coordinates Z1, Z2 of the nearest points P1, P2 based on the distance from the infinite line 103 to the nearest points P1, P2. The Z coordinate Z of the feature point 101 is calculated. As an example, when the distance from the infinite line 103 to the nearest point P1 is D1, and the distance from the infinite line 103 to the nearest point P2 is D2, the second Z coordinate calculating unit 47 (coordinate calculating unit 473) The Z-coordinate Z of the feature point 101 is calculated according to equation (1).

  Thus, the first Z coordinate calculation unit 46 calculates the Z coordinate of the feature point 101 projected onto the product unit 91, the die face unit 95, or the cross section 931, and the second Z coordinate calculation unit 47 calculates the cross section 931. The Z coordinate of the feature point 101 projected on the surplus portion 93 for which is not set is calculated. Since each feature point 101 has an XY coordinate defined in advance, the XYZ coordinate of each feature point 101 is calculated along with the calculation of the Z coordinate.

Returning to FIG. 2, the draw model generation unit 44 connects the feature points 101 from which the XYZ coordinates are obtained to form a polygon. For example, when adjacent feature points 101 are connected, a triangular polygon 102 can be created (see FIG. 1C). Thereby, the draw model 9 (see FIG. 9) of the press-formed product including the surplus portion 93 in which no CAD data exists is generated.
Note that the interval (XY coordinates) of the feature points 101 is set to a value that does not cause an error in the portion of the panel product where the polygonal bending angle is the largest. For this reason, the draw model generation unit 44 deletes (decimates) unnecessary feature points 101 because the interval between the feature points 101 may become finer than necessary and the amount of calculation may be enormous. Also good. As an example, when the difference between the Z coordinates of the adjacent feature points 101 is less than the threshold value, in other words, when the change of the Z coordinates in the adjacent feature points 101 is small, the feature points 101 may be deleted.

[Generate intermediate shape draw model]
By the way, due to the material characteristics of the plate material to be pressed, the product shape may not be formed by a single press process. In such a case, the plate material is first pressed to an intermediate shape and then the intermediate shape is processed. Trying to get shape. When the intermediate shape is pressed prior to the product shape, in the model shape evaluation by CAE, it is necessary to evaluate whether the intermediate shape can be processed instead of the product shape.
Therefore, in the draw model generation system 1 of the present invention, an intermediate shape draw model is also generated as necessary.

That is, the cross-section setting section 42 sets a plurality of intermediate-shaped cross sections at arbitrary positions of the product section 91 that are difficult to be formed by a single press process due to the material characteristics. Then, the coordinate calculation unit 43 projects the planar grid 10 onto the intermediate cross section set in the product unit 91, and the Z coordinate of the intermediate cross section that matches the XY coordinate of the feature point 101 is used as the feature point 101. Is calculated as the Z coordinate. Then, the draw model generation unit 44 connects the feature points 101 from which the XYZ coordinates are obtained to form a polygon. Thereby, the intermediate shape produced | generated in the press work process is acquirable.
Depending on the XY coordinates of the feature point 101, an intermediate cross section may not be set at the corresponding position. In such a case, by performing the predetermined weighting as described above, it is possible to calculate the Z coordinate of the feature point 101 to be projected at a position where the intermediate cross section is not set.

  Here, with reference to FIG. 6, the flow in the case of generating an intermediate-shaped draw model will be specifically described. FIG. 6A is a diagram schematically showing a cross section of the draw model 9. FIGS. 6B and 6C are diagrams showing a method for calculating the Z coordinate of the feature point 101 projected on the cross section of the intermediate shape, and FIG. 6B shows the intermediate shape at the projected position. FIG. 6C is a perspective view showing a calculation method when a cross section having an intermediate shape is not set at the projected position.

  With reference to FIG. 6 (A), the product part 91 has a portion Q that is difficult to be molded by a single press work because of the material property of the plate material. Therefore, the cross-section setting unit 42 sets a cross-section 915 for this location Q as shown in FIG. Note that the method of setting the cross section 915 is arbitrary. For example, the operator may set the cross section manually, or the cross section 915 may be set using a preset cross section template as in Patent Document 1 described above. Good. Moreover, the cross section (intermediate-shaped cross section 915) set to the location Q and the cross section 931 set to the surplus portion 93 may be integrated, or may be individual cross sections.

  When the cross section 915 having an intermediate shape is set, the coordinate calculation unit 43 projects the planar lattice 10. Here, since the cross section 915 having the intermediate shape is set with respect to the product portion 91, when the XY coordinate of the feature point 101 coincides with an arbitrary position of the cross section 915 having the intermediate shape, the feature point 101 has the intermediate shape. Are projected on both the cross section 915 and the product portion 91. In FIG. 6B, the feature point 101 is projected onto the Z coordinate Z3 of the cross section 915 having the intermediate shape and the Z coordinate Z4 of the product portion 91.

  In such a case, the coordinate calculation unit 43 (the first Z coordinate calculation unit 46) performs the Z coordinate Z3 of the cross section 915 of the intermediate shape at the position coinciding with the XY coordinates of the feature point 101 and the Z coordinate Z4 of the product unit 91. Among these, the Z coordinate having a larger value is calculated as the Z coordinate of the feature point 101. Since the intermediate-shaped section 931 is set above the product portion 91 in the Z direction, the Z coordinate having a larger value is basically the Z coordinate Z3 of the intermediate-shaped section 915.

On the other hand, when the feature point 101 is projected at a position where the cross section 915 of the intermediate shape is not set, the coordinate calculation unit 43 functions as the second Z coordinate calculation unit 47 and the intermediate shape set in the periphery. The Z coordinate of the feature point 101 is calculated using the cross section 915.
That is, as shown in FIG. 6C, the coordinate calculation unit 43 (second Z coordinate calculation unit 47) has two intermediate cross-sections 915A, which cross an infinite straight line passing through the feature point 101 and parallel to the Z direction. 915B is acquired, and the closest points P3 and P4 with the infinite straight line passing through the feature point 101 are calculated from the intermediate-shaped cross sections 915A and 915B. Then, the Z coordinates Z5 and Z6 of the nearest points P3 and P4 are weighted based on the distance from the infinite straight line, and the Z coordinate of the feature point 101 is calculated.

[Draw model generation system processing]
7 and 8 are flowcharts showing the flow of processing of the draw model generation system 1. As shown in FIG. 7, the draw model is generated by using the preparation process for setting the shape data of the product part 91 and the die face part 95 and the plane lattice 10 and the data prepared in this preparation process. Generating a draw model. More specifically, the preparation process is configured by the processes of steps S1 to S3, and the draw model generation process is configured of the processes of steps S4 to S7.

  In step S <b> 1, the operator uses the input device 2 to generate shape data of the product unit 91 and the die face unit 95 and stores the shape data in the storage device 8. In step S <b> 2, the operator sets a cross section (a cross section of the surplus portion 93, a cross section of an intermediate shape) using the input device 2 and stores the cross section in the storage device 8. In step S <b> 3, the worker generates the planar grid 10 using the input device 2 and stores it in the storage device 8.

  In step S <b> 4, the coordinate calculation unit 43 projects the planar grid 10 onto the product unit 91, the die face unit 95, and cross-sectional shape data (CAD data). In step S5, the coordinate calculation unit 43 performs a Z coordinate calculation process. Here, the Z coordinate calculation process will be described with reference to FIG.

  In step S <b> 11, the determination unit 45 determines whether or not the feature point 101 is projected on the CAD plane. Here, the CAD surface refers to the product part 91 and the die face part 95. That is, when the feature point 101 is projected onto the product portion 91 or the die face portion 95, YES is obtained in step S11, and the feature point 101 is located at a position other than the product portion 91 and the die face portion 95, that is, within a cross-sectional area described later. If projected, NO in step S11.

  When YES in step S11, in step S12, the first Z coordinate calculation unit 46 acquires the Z coordinates of the product part 91 and the die face part 95 at the projected positions, and moves the process to step S13.

  In step S <b> 13, the determination unit 45 determines whether or not the feature point 101 is projected in the cross-sectional area. Here, the cross-sectional area is an area where the cross-section is set. Specifically, an intermediate shape is formed in the surplus portion 93 where the cross-section 931 is set and a difficult part Q in the product portion 91. The position where the cross section 915 is set is said. That is, when the feature point 101 is projected to the position where the surplus portion 93 or the intermediate cross section 915 is set, YES is determined in step S13, and the process proceeds to step S14. On the other hand, if NO at step S13, the process proceeds to step S18.

  In step S <b> 14, the determination unit 45 determines whether a cross section exists at a position that matches the XY coordinates of the feature point 101. That is, in the case where there is no 931 set in the surplus portion 93 or a cross section 915 having an intermediate shape set in the difficult-to-mold location Q in the product portion 91 at a position that coincides with the XY coordinates of the feature point 101. In step S14, NO is determined, and the process proceeds to step S15.

In step S <b> 15, the second Z coordinate calculation unit 47 acquires two or more cross-sections 931 that straddle an infinite straight line that passes through the feature point 101 and is parallel to the Z direction, and the nearest to the infinite straight line on the cross-section 931. Extract points. In subsequent step S16, the second Z coordinate calculation unit 47 weights the Z coordinate of the closest point based on the distance to the infinite straight line, and calculates and acquires the Z coordinate. After obtaining the Z coordinate, the process proceeds to step S18.
Note that the above equation (1) is used to calculate the Z coordinate in step S16.
In the description of steps S15 to S16 described above, the case where the Z coordinate is acquired in the surplus portion 93 where the cross section 931 is set has been described. However, the intermediate cross section 915 of the product portion 91 is set. The same applies when the Z coordinate is acquired at the position.

  Returning to step S14, the cross-section 931 set in the surplus portion 93 and the cross-section 915 having an intermediate shape set in the difficult-to-mold point Q in the product portion 91 exist at a position that coincides with the XY coordinates of the feature point 101. If yes, YES is determined in the step S14, and the process proceeds to a step S17.

  In step S <b> 17, the first Z coordinate calculation unit 46 calculates and acquires the Z coordinate based on the cross section parameters of each cross section. Specifically, the Z coordinate of the cross section 931 or the intermediate cross section 915 is calculated and acquired as the Z coordinate of the feature point 101, and the process proceeds to step S18.

In step S18, when there are two acquired Z coordinates, the larger Z coordinate is acquired as the Z coordinate of the feature point 101. Here, the case where there are two acquired Z coordinates is YES in both step S11 and step S13, and the feature point 101 is an intermediate-shaped cross section 915 at a difficult part Q in the product portion 91. This is a case of projecting to the set position. In this case, there are two, the Z coordinate acquired in step S12 and the Z coordinate acquired in step S16 or 17. Accordingly, the larger one (basically, the Z coordinate acquired in step S16 or 17) is acquired as the Z coordinate of the feature point 101, and the process proceeds to step S19.
By the way, in principle, there is no region where neither the CAD plane nor the cross section exists. Therefore, in at least one of step S11 and step S13, the answer is always YES, and the Z coordinate is acquired. For safety, faces of three or more sides may be automatically created by already known software and linked with a polygon hole filling process for filling a holed area on a polygon mesh or a polygon grid.

  In step S19, the Z coordinate acquired in step S18 is associated with the XY coordinate of the feature point 101 and stored in the storage device 8. Thereafter, the process proceeds to step S20, where all the feature points 101 are processed, and the Z coordinate calculation process is terminated.

  Returning to FIG. 7, when the Z coordinates are calculated for all the feature points 101 (that is, the XYZ coordinates are acquired), the draw model generation unit 44 deletes the unnecessary feature points 101 in step S6. Specifically, the draw model generation unit 44 deletes the feature point 101 when the change in the Z coordinate is small at the adjacent feature point 101. Subsequently, in step S <b> 7, the draw model generation unit 44 connects adjacent feature points 101 to form a polygon, and ends the process.

  According to this embodiment described above, the following effects can be expected.

(1) In the draw model generation system 1, when a plurality of cross sections 931 are set for the surplus portion 93, a plurality of feature points defined by XY coordinates for the product portion 91, the die face portion 95, and the cross section 931. 101 is projected, and the Z coordinate of the shape data at a position that coincides with the XY coordinates of the feature point 101 is calculated as the Z coordinate of the feature point 101. Then, the feature points 101 whose XYZ coordinates are calculated are connected to form a polygon.
As a result, the surplus portion surface (polygon) can be automatically obtained from the cross section set in the surplus portion 93, and the generation of the surface data, which has conventionally required an enormous amount of time, can be performed in a short time. . Further, as described in Patent Document 1, polygon (mesh) data is required for model shape evaluation by CAE. In this regard, in the draw model generation system 1 of the present invention, since the draw model 9 is generated from polygon data, the model shape can be evaluated by CAE immediately after the draw model 9 is generated.

(2) At this time, when the cross section 931 exists at a position that coincides with the XY coordinates of the feature point 101, the Z coordinate of the cross section 931 is calculated as the Z coordinate of the feature point 101, while If the cross section 931 does not exist at a position that coincides with the XY coordinates, a candidate cross section is acquired, and the Z coordinate of the feature point 101 is calculated based on this candidate cross section.
Thereby, it is possible to appropriately polygonize the surplus portion 93 where the cross section 931 is not set. As a result, it is not necessary to set the cross section 931 in detail more than necessary, and the time required to generate the draw model 9 can be shortened.

(3) In the calculation of the Z coordinate based on the candidate cross section, the draw model generation system 1 acquires two or more cross sections 931 across the infinite straight line parallel to the Z direction passing through the feature point 101 to be calculated as candidate cross sections. The Z coordinate of the feature point 101 is calculated by weighting the Z coordinate of the closest point to the infinite line on the candidate cross section based on the distance between the infinite line and each closest point.
Usually, since the press product has a shape having a certain continuity, the shape of the surplus portion 93 can be generated with high accuracy by performing interpolation by weighting based on such a distance. As a result, the draw model 9 whose quality is guaranteed by CAE can be generated in a short time.

(4) Further, in the draw model generation system 1, a plurality of intermediate shape cross sections 915 generated in the press working process are set for the product portion 91, and the intermediate shapes are acquired based on the cross sections 915.
As a result, it is possible to generate a draw model having an intermediate shape in the case of a product shape that cannot be formed by a single press process due to the relationship between the material characteristics of the plate material, and whether the intermediate shape can be appropriately formed is evaluated by CAE. be able to.

  (5) Moreover, in the draw model production | generation system 1, the space | interval of the plane grating | lattice 10 was made into the predetermined space | interval (0.5 mm). As a result, the polygon bending angle can be kept below θmax, and an error can be prevented in the model shape evaluation by CAE.

The preferred embodiment of the draw model generation system 1 of the present invention has been described above. However, the present invention is not limited to the above-described embodiment, and can be modified as appropriate.
For example, in the present embodiment, the feature points 101 are arranged in a grid pattern, but the present invention is not limited to this. That is, the feature points 101 need only have XY coordinates defined, and the present invention can be applied even if they are irregularly arranged.

  In the present embodiment, when the feature point 101 is projected onto the product unit 91 (YES in step S12 in FIG. 8), the Z coordinate is calculated using the intermediate-shaped cross section 915. In this respect, it is sufficient to generate the intermediate shape only for the portion Q that is difficult to press, and it is not necessary to generate the intermediate shape for all of the product portions 91. That is, for the feature point 101 projected on the predetermined area (location Q) of the product part 91, a larger value is calculated as the Z coordinate between the Z coordinate of the product part 91 and the Z coordinate of the cross section 915 of the intermediate shape. For the feature point 101 projected outside the predetermined area (location Q) of the part 91, the Z coordinate of the product part 91 is calculated as the Z coordinate of the feature point 101.

DESCRIPTION OF SYMBOLS 1 Draw model production | generation system 2 Input device 4 Arithmetic device 41 Plane lattice production | generation part 42 Section setting part 43 Coordinate calculation part 44 Draw model production | generation part 45 Judgment part 46 1st Z coordinate calculation part 47 2nd Z coordinate calculation part 471 candidate Section acquisition part 472 Nearest point acquisition part 473 Coordinate calculation part 9 Draw model 91 Product part 93 Extra part 931 Section 95 Die face part 10 Planar lattice 101 Feature point

Claims (6)

A draw model generation method for generating a draw model of a press-molded product including a surplus part formed around a product part from CAD data having a product part and a die face part,
A step of setting a plurality of cross sections of the surplus portion between the product portion and the die face portion , wherein the cross section setting portion of the draw model generation system ;
A cross section in which the coordinate calculation unit of the draw model generation system projects a plane point group composed of a plurality of feature points, each defined by individual XY coordinates, onto the cross section, and matches the XY coordinates of the feature points Calculating the Z coordinate of the feature point as the Z coordinate of the feature point;
A step of generating a draw model of the press-molded product by a draw model generation unit of the draw model generation system connecting the feature points whose XYZ coordinates are obtained by the step to form a polygon and acquiring the surplus portion. and, only including,
The step of calculating the Z coordinate of the feature point includes:
A step of determining whether or not the cross section exists at a position coinciding with the XY coordinates of the feature point, by a determination unit of the coordinate calculation unit;
The first Z coordinate calculation unit of the coordinate calculation unit calculates the Z coordinate of the cross section as the Z coordinate of the feature point when the cross section exists;
The second Z coordinate calculation unit of the coordinate calculation unit acquires a candidate cross section from a plurality of cross sections when the cross section does not exist, and calculates a Z coordinate of the feature point based on the acquired candidate cross section. Process, including,
The step of calculating the Z coordinate of the feature point based on the candidate cross-section includes:
A candidate cross-section acquisition unit of the second Z coordinate calculation unit acquires two or more cross-sections across an infinite line parallel to the Z direction passing through the feature points as candidate cross-sections;
A closest point acquisition unit of the second Z coordinate calculation unit calculates a closest point between the infinite line and each of the candidate cross sections, and acquires a Z coordinate of the closest point;
The coordinate calculation unit of the second Z coordinate calculation unit performs weighting on the Z coordinate of each nearest point based on the distance between the infinite line and each nearest point, so that the feature points And a step of calculating a Z coordinate . The cross-section setting unit of the draw model generation system sets a plurality of intermediate-shaped cross-sections generated during the pressing process of the product part with respect to the product part,
The coordinate calculation unit of the draw model generation system projects the plane point group on the cross section of the intermediate shape, and uses the Z coordinate of the cross section of the intermediate shape that matches the XY coordinate of the feature point as the Z of the feature point. Calculating as coordinates;
A step of generating a draw model of the press-molded product by connecting the feature points from which the XYZ coordinates are obtained by the step to form a polygon and acquiring the intermediate shape by the draw model generation unit of the draw model generation system ; The drawing model generation method according to claim 1, further comprising: 3. The draw model according to claim 1, wherein the step of generating a plane point group by the plane grid generation unit of the draw model generation system arranges a plurality of feature points in a grid at predetermined intervals. Generation method. A draw model generation system for generating a draw model of a press-molded product including a surplus part formed around a product part from CAD data having a product part and a die face part,
A storage unit for storing a plane point group generated by a plurality of feature points each defined by individual XY coordinates;
A cross-section setting section for setting a plurality of cross-sections of the surplus portion between the product section and the die face section;
A coordinate calculation unit that projects the plane point group onto the cross section and calculates the Z coordinate of the cross section that coincides with the XY coordinates of the feature point as the Z coordinate of the feature point;
By connecting the feature points from which the XYZ coordinates were obtained by the coordinate calculation unit into a polygon, and obtaining the surplus part, a draw model generation unit that generates a draw model of the press-molded product , and
The coordinate calculation unit
A determination unit that determines whether or not the cross section exists at a position that coincides with the XY coordinates of the feature point;
A first Z coordinate calculator that calculates the Z coordinate of the cross section as the Z coordinate of the feature point when the cross section exists;
A second Z coordinate calculation unit that acquires a candidate cross section from a plurality of cross sections when the cross section does not exist, and calculates the Z coordinate of the feature point based on the acquired candidate cross section; and
The second Z coordinate calculator is
A candidate cross-section acquisition unit for acquiring two or more cross-sections across an infinite straight line parallel to the Z direction passing through the feature points as candidate cross-sections;
Calculating a closest point between the infinite straight line and each of the candidate cross-sections, and acquiring a Z-coordinate of the closest point;
A coordinate calculation unit that calculates the Z coordinate of the feature point by weighting the Z coordinate of each closest point based on the distance between the infinite line and each closest point. Characteristic draw model generation system. The cross-section setting unit sets a plurality of intermediate-shaped cross-sections generated in the press process of the product part with respect to the product part,
The coordinate calculation unit projects the plane point group on the cross section of the intermediate shape, calculates the Z coordinate of the cross section of the intermediate shape that coincides with the XY coordinates of the feature point as the Z coordinate of the feature point,
The draw model generation unit may polygonizing connecting the feature points between the XYZ coordinate is obtained, by acquiring the intermediate shape, according to claim 4, characterized in that to produce a draw model of the press molded product Draw model generation system. 6. The draw model generation system according to claim 4 , wherein the plane point group is generated by arranging a plurality of feature points in a grid pattern at predetermined intervals.

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