JP2012068867A - Metal mold shape data creation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal mold shape data creation system for creating metal mold shape data of a metal mold by which a press molded product without surface distortion is manufactured.SOLUTION: A metal mold shape data creation system 100 includes: a metal mold shape data creation part 21 which creates the metal mold shape data based on design shape data; a creation part 23 of shape data after press molding, which creates the shape data after the press molding of the press molded product after molding; a curvature calculation part 31 which calculates the curvature of a first setting area in first shape data and the curvature of a second setting area in second shape data; a curvature difference calculation part 32 which calculates the curvature difference based on the calculated curvatures; a creation part 33 of shape data for correction, which creates the shape data for correction of the shape for correction based on the curvature difference; and a metal mold shape data correction part 35 which corrects the metal mold shape data based on the shape data for correction.

Description

  The present invention relates to a mold shape data creation system for creating mold shape data of a mold used when manufacturing a press-formed product.

  Conventionally, the outer plate parts constituting the body of the vehicle body are formed by press working. It is known that a press-molded product molded by press working is subject to spring back due to elastic recovery after molding, which leads to a decrease in molding accuracy. For this reason, there is a case where a molded product (press-molded product) as designed cannot be formed with a press die (mold) produced in the same shape as the part drawing. As a technique for solving such a problem, there are those described in Patent Documents 1 and 2, which are cited below.

  In the technique described in Patent Document 1, the stress distribution in the plate thickness direction acting on the plate material model when the plate material model is pressed to the bottom dead center by the mold model is calculated, and the reversal stress obtained by reversing the stress distribution is calculated. Modify the mold model based on the distribution. Moreover, in the technique described in patent document 2, based on the curvature of the curved surface of the said mold calculated based on the shape data of a metal mold | die, and the shape data of the press molded product press-molded using the metal mold | die. A difference from the calculated curvature of the curved surface is calculated, and the mold shape is corrected based on the difference.

  Here, even on design surfaces such as door panels and roof panels, surface distortion occurs during press molding. However, such surface distortion is not a large deformation that occurs in the hat-shaped member, but is relatively small. For this reason, even if the techniques described in Patent Documents 1 and 2 are applied, it is not easy to mold a molded product as designed. In addition, it is conceivable to perform press molding after producing a mold once, and to correct the mold based on the shape of the press-molded product formed by the press molding. Relied on workers who had mastered the technology.

JP 2003-33828 A JP 2003-340528 A

  SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a mold shape data creation system that creates mold shape data of a mold that can produce a press-molded product without surface distortion.

  The feature of the mold shape data creation system according to the first invention for achieving the above object is that the design shape of the press-molded product on the design to create the mold shape data of the mold for producing the press-molded product. Based on data, a mold shape data creation unit for creating the mold shape data, a post-molding shape data creation unit for creating post-molding shape data of a press-molded product after molding, and the post-molding shape The first shape data reflecting the shape of the predetermined first setting area in the data, and the shape of the predetermined second setting area wider than the first setting area including the first setting area in the shape data after press molding And acquiring the second shape data reflected more roughly than the first shape data, and the curvature of the first setting region in the first shape data and the second shape data in the second shape data 2. A curvature calculator that calculates the curvature of the set area, a curvature difference calculator that calculates a curvature difference based on the curvature of the first shape data and the curvature of the second shape data, and correction based on the curvature difference A correction shape data generation unit that generates correction shape data for a target shape, and a mold shape data correction unit that corrects the mold shape data based on the correction shape data.

  According to the feature of the first invention, the curvature of the first setting area acquired based on the post-pressing shape data of the press-formed product after forming, and the curvature of the second setting area wider than the first setting area. Since the correction shape for correcting the mold shape data is created using the above, it is possible to easily create the correction shape capable of correcting the distortion that can only be determined by a highly skilled person. Therefore, since the calculation load related to the creation of the correction shape data can be reduced, a metal mold that does not require a high-performance arithmetic processing device and can produce a press-molded product without surface distortion. Shape data can be created.

  The mold shape data creation system according to the second invention is characterized in that the post-molding shape data creation unit performs a molding simulation using the mold shape data and press conditions used for manufacturing the press-molded product. It is preferable to create simulation shape data as shape data after press forming.

  According to the second aspect of the invention, the simulation shape data of the press-formed product after press molding is created based on the design shape data of the press-formed product and the die shape data generated using the design shape data. Can do. Therefore, it is possible to create mold shape data optimal for producing a press-molded product having no surface distortion without producing a mold and performing trial driving.

  In addition, the mold shape data creation system according to the third aspect is characterized in that the curvature difference calculation unit uses a maximum value of a curvature difference in a strain setting area composed of a plurality of the first setting areas adjacent to each other. A curvature difference is calculated, the correction shape data creation unit creates the correction shape data based on the maximum curvature difference, and the mold shape data correction unit is created based on the maximum curvature difference The correction shape data is used to correct data corresponding to the distortion setting region of the mold shape data.

  According to the feature of the third aspect of the invention, the correction shape data can be uniquely set and created using the maximum curvature difference. Therefore, since the arithmetic processing can be simplified, the mold shape data can be created without using a high-performance arithmetic processing device.

  A feature of the mold shape data creation system according to the fourth aspect of the invention is that in the region where the mold shape data is corrected, the outer periphery of the correction shape is defined using a curvature smaller than the curvature of the correction shape. A surface shape data creation unit that creates surface shape data that approximates the shape of a press-formed product in design, and the mold shape data correction unit corrects the mold shape data using the surface shape data It is in.

  According to the feature of the fourth aspect of the invention, since the outer periphery of the correction shape produced using the maximum curvature difference is corrected using a curvature smaller than the curvature of the correction shape, the portion is not a man-made natural shape. Can be configured. That is, in order to connect the correction shape and the mold shape (design) using a curvature smaller than the curvature of the correction shape, the mold shape data corrected with the correction shape is shaped with a natural flow and can do. Therefore, it is possible to create mold shape data that can form a press-molded product with less distortion.

  In addition, the mold shape data creation system according to the fifth invention is characterized in that the mold shape data correction unit includes a height of the designed mold shape data in a third setting area composed of a plurality of strain setting areas. When the difference between the height of the corrected mold shape data is larger than a preset value, the curvature is smaller than the curvature of the entire shape of the shape data after press molding in the third setting region. The point is that data corresponding to the third setting area of the mold shape data is corrected based on the shape.

  According to the fifth aspect of the present invention, by correcting the mold shape data with the correction shape, even if there is a large difference from the expected height of the press-formed product, it is within a relatively wide third setting region. Since the height is corrected with a shape having a curvature smaller than the curvature of the entire shape of the shape data after press forming, the entire height can be adjusted with a natural shape that is not artificial. That is, when the mold shape data is repeatedly corrected, a large difference from the initial height may occur. Therefore, when a value serving as a determination threshold is set in advance, and the difference between the height of the mold shape data after design and the height of the mold shape data after correction is larger than the set value The overall height can be adjusted. Therefore, it is possible to form a press-molded product as designed without any distortion. In addition, by using a small curvature, it is possible to obtain a natural shape that follows the design shape, and it is possible to perform height adjustment that does not cause distortion. Thus, according to this feature, it is possible to create mold shape data capable of forming a press-formed product that is less distorted.

It is a block diagram of a mold shape data creation system. It is a figure explaining various areas. It is the figure which showed typically about the process which a metal mold | die shape data preparation system performs. It is a figure shown about the example which produces optimal metal mold | die shape data from design shape data. It is a figure shown about the example which produces optimal metal mold | die shape data from design shape data.

  Hereinafter, embodiments of the present invention will be described in detail. The mold shape data creation system 100 according to the present invention can create mold shape data of a mold used to manufacture a press-formed product. Here, in general, when a press-molded product is manufactured using a mold, the shape of the press-molded product, the shape of the material, the characteristics of the material (material), the press conditions, etc. It is not easy to construct a press molded product (press molded product having a shape as designed). That is, surface distortion may occur at a predetermined position of the press-formed product.

  The mold shape data creation system 100 creates a mold shape data by performing a simulation based on the design shape (design shape) of the press-molded product so that the above-described surface distortion does not occur in the press-molded product. It is configured to be possible. Therefore, according to the mold shape data creation system 100, a press-molded product having a shape as designed can be appropriately obtained without producing a mold and performing trial punching, or without actually performing press molding. Mold shape data of molds that can be manufactured can be created. In the present embodiment, an example in which the press-formed product is a vehicle door panel and the mold shape data creation system 100 manufactures a mold used when manufacturing the vehicle door panel will be described.

1. Configuration of Mold Shape Data Creation System FIG. 1 is a block diagram schematically showing the schematic configuration of such a mold shape data creation system 100. The mold shape data creation system 100 includes a design shape data input unit 11, a material shape data input unit 12, a material property data input unit 13, a press data input unit 14, a mold shape data creation unit 21, and a mold shape data storage unit. 22, post-molding shape data creation unit 23, strain region setting unit 24, curvature calculation unit 31, curvature difference calculation unit 32, modification shape data creation unit 33, surface shape data creation unit 34, mold shape data modification unit 35 Each of the functional units of the height difference calculation unit 36 is configured. The mold shape data creation system 100 having such respective functional units is constructed by hardware and / or software, or a functional unit for performing various operations related to creation of mold shape data using a CPU as a core member. Yes.

  The design shape data input unit 11 receives design shape data of a press-formed product on design. In the present embodiment, the press-molded product is a vehicle door panel. The design press-formed product is a design value (design size) of the press-formed product. Design shape data is data indicating the shape of a press-formed product at such a design stage. Such design shape data is uniquely determined, for example, designed by a designer and having a predetermined tolerance. Therefore, the design shape data input unit 11 receives data indicating the shape of the door panel at the design stage. The design shape data input to the design shape data input unit 11 is transmitted to a mold shape data creation unit 21 described later.

  The material shape data input unit 12 receives data indicating the shape of a material used when manufacturing the door panel. The data indicating the shape of the material is the shape of the material before press molding. Specifically, the size, dimension, thickness, etc. of the material correspond. Therefore, the material shape data input unit 12 receives the size, dimensions, thickness, etc. of the material used when manufacturing the door panel. The data input to the material shape data input unit 12 is transmitted to a post-press forming shape data creation unit 23 described later.

  The material characteristic data input unit 13 receives data indicating the material characteristics of a material used when manufacturing the door panel. The data indicating the material characteristics of the material is data indicating the characteristics of the material before press molding. Specifically, it corresponds to the type of material, hardness, and the like. Therefore, the material property data input unit 13 receives the type, hardness, and the like of the material used when manufacturing the door panel. Data input to the material property data input unit 13 is transmitted to a post-press-molding shape data creation unit 23 described later.

  The press data input unit 14 receives data indicating various conditions when pressing the material. The various conditions at the time of pressing correspond to data indicating the pressure at the time of pressing, the moving speed of the mold, the environmental temperature, and the like. Accordingly, the press data input unit 14 is input with data indicating the pressure at the time of pressing a material used when manufacturing the door panel, the moving speed of the mold, the environmental temperature, and the like. The data input to the press data input unit 14 is transmitted to a post-molding shape data creation unit 23 described later.

  The mold shape data creation unit 21 creates mold shape data based on the design shape data of the designed press-formed product. The design shape data of the designed press-formed product is transmitted from the above-described design shape data input unit 11. The mold shape data is data indicating the shape of a mold used when the door panel is manufactured by press molding. The mold shape data creation unit 21 configures a molding surface of the mold along the outer surface of the door panel defined by the design shape data. Therefore, it becomes possible to manufacture a press-molded product by pressing the material before press molding against the molding surface of the mold. The mold shape data created by the mold shape data creation unit 21 is stored in a mold shape data storage unit 22 to be described later.

  The mold shape data storage unit 22 stores mold shape data. As described above, the mold shape data is created by the mold shape data creation unit 21. The mold shape data stored in the mold shape data storage unit 22 is configured to be corrected by a mold shape data correction unit 35 described later, and is configured to be transmitted to an elevation difference calculation unit 36 described later. Yes.

  The post-molding shape data creation unit 23 performs molding simulation using the mold shape data and the press conditions used for manufacturing the press-molded product, and the simulation shape data as post-molding shape data of the press-molded product after molding. Create As the mold shape data, data stored in the mold shape data storage unit 22 is used. The press conditions used for manufacturing the press-formed product are press conditions used for manufacturing the door panel, and correspond to the above-described material shape data, material property data, and press data. These data are transmitted from the material shape data input unit 12, the material property data input unit 13, and the press data input unit 14, respectively. The post-molding shape data creation unit 23 performs molding simulation using these data. A known technique can be used for the molding simulation. Simulation shape data indicating the shape of the press-formed product after forming is created by the forming simulation. In the present embodiment, the simulation shape data corresponds to the shape data after press forming according to the present invention. The simulation shape data is transmitted to the curvature calculation unit 31 described later.

  The curvature calculation unit 31 includes first shape data that finely (in detail) reflects the shape of the predetermined first setting area s in the simulation shape data, and the first setting area s including the first setting area s in the simulation shape data. The second shape data reflecting the shape of the predetermined second setting region t wider than the first shape data is acquired. The simulation shape data is transmitted from the post-molding shape data creation unit 23. The first setting area s is an area obtained by cutting a cross section of simulation shape data, which is three-dimensional data, with two-dimensional data having a predetermined length and dividing the two-dimensional data with a predetermined length. FIG. 2 is a diagram for facilitating understanding of the area used in the present embodiment, and the predetermined first setting area is denoted by reference numeral s. The first shape data corresponds to data reflecting the shape of the first setting area s. The second setting area t is an area defined by a section wider than the first setting area s including the first setting area s by cutting out the cross section of the simulation shape data, which is three-dimensional data, with the two-dimensional data. Such a second setting area t is indicated by a reference sign t in FIG. The shape of the second setting area t in the second shape data is reflected more roughly than the first shape data. That is, if the shape is finely reflected in the first setting area s in the first shape data, for example, every 10 mm, the shape is roughly reflected in the second setting area t in the second shape data, which is wider than 10 mm, for example, every 100 mm. The And the curvature calculation part 31 calculates the curvature of the 1st setting area | region s in such 1st shape data, and the curvature of the 2nd setting area | region t in 2nd shape data.

  The curvature can be calculated using a known method. An example is shown below. First, a point group corresponding to the shape to be calculated is set as a sample point, and three or more sample points are set among the plurality of sample points. Then, a quadratic curve passing through the vicinity of the point group having the vertex near the center is applied as an approximate curve, and the curvature is calculated based on the curvature at the center of the sample point of the applied approximate curve. Since this approximate curve is a quadratic curve, a shape passing through a position that matches or approximates a plurality of sample points is set by increasing or decreasing the coefficient value. Further, this quadratic curve can also be understood as a function capable of quadratic differentiation. Of course, it is also possible to use an approximation curve other than a quadratic curve, for example, a higher-order function curve higher than a cubic function, a sine curve, a hyperbola, or the like.

  Moreover, in order to obtain | require a curvature, it is also possible to acquire directly from the extent of the curvature in the sample point center part (near a vertex) of an approximated curve. For example, the degree of curvature of the approximate curve can be digitized and stored as a table, and the curvature can be obtained from the table based on the degree of curvature. The curvature can be calculated using such various methods. Of course, it is naturally possible to calculate using other methods. The calculated curvature is transmitted to the curvature difference calculation unit 32 described later.

  The curvature difference calculation unit 32 calculates a curvature difference based on the curvature of the first shape data and the curvature of the second shape data. The curvature is calculated and transmitted for each of the first setting area s and the second setting area t by the curvature calculation unit 31 described above. The curvature difference calculation unit 32 calculates a difference between two curvatures, that is, a curvature difference, from the curvature of the first setting region s calculated from the first shape data and the curvature of the second setting region t calculated from the second shape data. To do. Here, the difference in curvature is an index indicating the difference in shape between the first shape data and the second shape data. Therefore, when the difference in curvature is zero, the two data are not different, and the first shape data and the second shape data match or are in a parallel state. For example, if the curvature calculated from the first shape data is 1/8000 and the curvature calculated from the second shape data is 1/12000, the difference in curvature is 1/24000. The curvature difference obtained by the curvature difference calculation unit 32 is transmitted to a correction shape data creation unit 33 described later.

  Here, in this embodiment, the curvature difference calculation unit 32 sets the maximum curvature difference by selecting the maximum value of the curvature difference in the distortion setting region D including the plurality of first setting regions s adjacent to each other. The distortion setting area D is composed of a plurality of first setting areas s adjacent to each other, and is denoted by reference numeral D in FIG. The distortion setting area D is an arbitrary range in which distortion can occur. This range is a range stored and calculated in the strain area setting unit 24. For example, an arbitrary range in which distortion can occur is calculated in advance using a known strain calculation unit, and the range in which distortion can occur is determined. It is possible to set. In addition, this range can be stored as a database of a range in which distortion can occur empirically. Note that this range includes a plurality of first setting areas s as described above and is smaller than the second setting area t. Therefore, the distortion setting area D includes a plurality of predetermined areas s, and the curvature of each of the first setting areas s is calculated by the curvature calculation unit 31. The curvature difference calculation unit 32 includes a curvature for each first setting region s in the first shape data calculated by the curvature calculation unit 31 and a distortion setting region D of the curvature of the second shape data calculated by the curvature calculation unit 31. The maximum curvature difference is calculated by obtaining the maximum value of the curvature difference at. This maximum curvature difference is calculated for each of the plurality of strain setting regions D. The curvature difference calculation unit 32 transmits this maximum curvature difference to the correction shape data creation unit 33 described later.

  The correction shape data creation unit 33 creates correction shape data of the correction shape based on the curvature difference. In particular, in the present embodiment, the correction shape data creation unit 33 creates correction shape data based on the maximum curvature difference. The maximum curvature difference is calculated by the curvature difference calculation unit 32 described above. The correction shape data creation unit 33 obtains a correction shape whose curvature radius is the reciprocal of the maximum curvature difference, and creates correction shape data indicating the correction shape.

  As described above, the correction shape data creation unit 33 according to the present embodiment has the correction shape in which the radius of curvature is the reciprocal of the maximum curvature difference (maximum curvature difference) among the curvature differences included in the distortion setting region D. Create shape data for correction. Therefore, in the present embodiment, the correction shape of the strain setting region D is created by one curvature difference based on the maximum curvature difference. For example, if the curvature calculated from the first shape data in the distortion setting region D is 1/8000 and the curvature calculated from the second shape data is 1/12000, the curvature difference is 1/24000. When 1/24000 indicates the maximum value in the distortion setting region D, the correction shape data creation unit 33 creates correction shape data of a correction shape having a curvature radius of 24000R (reciprocal).

  The correction shape data creation unit 33 calculates an inversion value obtained by inverting the value of the maximum curvature difference input to the correction shape data creation unit 33, and creates correction shape data based on the inversion value. To do. Specifically, for example, it is assumed that the upward convex side is set to the plus side and the downward convex side is set to the minus side. In such a case, for example, when the curvature calculated from the first shape data (1/8000) and the curvature calculated from the second shape data (1/12000) are both convex values, the maximum curvature difference is Since it is input as (+1/24000), an inversion value (−1/24000, a value toward the convex side that cancels out) in which the direction of the unevenness is inverted is calculated, and for correction based on this inversion value Create shape data. Also, for example, when the curvature calculated from the first shape data is a downward convex value (−1/8000) and the curvature calculated from the second shape data is an upward convex value (1/12000) Since the maximum curvature difference is input as −1/4800, an inversion value (+1/4800, the value to be offset to the convex side) is calculated by inverting the direction of the unevenness, and based on this inversion value Create shape data for correction.

  The surface shape data creation unit 34 approximates the outer periphery of the correction shape to the shape of the designed press-molded product by using a curvature smaller than the curvature of the correction shape in and around the region where the mold shape data is corrected. Create surface shape data. The region in which the mold shape data is corrected is the strain setting region D in which the above-described curvature difference is not zero and the correction shape data generation unit 33 has generated the correction shape data. Although details will be described later, in the strain setting region D in which the correction shape data is created, the mold shape data is corrected using the correction shape data. The curvature smaller than the curvature of the correction shape is a curvature having a higher flatness than the correction shape in the corrected strain setting region D. Therefore, the surface shape data creation unit 34 creates surface shape data that approximates the shape of the designed press-formed product with a shape having a radius of curvature larger than the radius of curvature of the shape for correction. More specifically, when the curvature radius of the correction shape is 4000R, it is preferable to approximate the outer periphery of the correction shape with a shape having a curvature radius larger than 4000R, for example, a curvature radius of about 20000R to 30000R. . The surface shape data created by the surface shape data creation unit 34 is transmitted to a mold shape data correction unit 35 described later.

  The mold shape data correction unit 35 corrects the mold shape data based on the correction shape data. The correction shape data is transmitted from the correction shape data creation unit 33 described above. The mold shape data is stored in the mold shape data storage unit 22. In the present embodiment, as described above, the correction shape is created using the maximum curvature difference. Therefore, the mold shape data correction unit 35 is stored in the mold shape data storage unit 22 using the correction shape data transmitted from the correction shape data generation unit 33 generated based on the maximum curvature difference. Data corresponding to the distortion setting area D of the mold shape data is corrected.

  Thus, in this embodiment, the mold shape data is corrected for each strain setting region D. Even if the processing is completed for all the areas related to the plurality of distortion setting areas D, surface distortion may remain. In addition, there is a region where surface distortion occurs due to the correction. Furthermore, when a molding simulation is performed using the corrected mold shape data, a new surface distortion may occur. Therefore, the mold shape data creation system 100 is repeatedly performed after the molding simulation is performed until the difference in curvature falls within a predetermined threshold.

  The mold shape data correction unit 35 corrects the mold shape data using the surface shape data. The surface shape data is transmitted from the surface shape data creation unit 34 described above. By correcting the mold shape data using the surface shape data in this way, the region corrected using the correction shape data described above and the region corrected using the correction shape data are adjacent. The boundary with the area can be smoothed.

  The height difference calculation unit 36 calculates the height of the mold shape data after the design and the height of the mold shape data after the correction in the third setting region u (see FIG. 2) including the plurality of strain setting regions D. Calculate the difference. The height of the mold shape data after the design is the height of the designed mold shape. The height of the mold shape after correction is the height of the mold shape corrected by the mold shape data correction unit 35. The height may be the average height of the third setting region u, or may be the height of the central portion in the third setting region u or the height of the surrounding portion. Alternatively, it is possible to set the height for each of a plurality of points set in the third setting area u. The height difference calculation unit 36 calculates the height of the designed mold shape data (designed mold shape) and the corrected mold shape data (modified mold) obtained by performing the molding simulation. Calculate the difference from the height of the shape. This calculation result is transmitted to the mold shape data correction unit 35.

  The mold shape data correction unit 35 determines the difference between the height of the design mold shape data transmitted from the height difference calculation unit 36 and the height of the corrected mold shape data obtained by performing the molding simulation. When the value is larger than a preset value, the third shape setting data u corresponds to the third setting region u of the mold shape data based on the shape having a curvature smaller than the curvature of the entire shape of the simulation shape data in the third setting region u. Correct the data. The preset value is a determination threshold value, which can be “greater than 0”, or can be set as a specific numerical value as “several mm”. When the maximum value of the difference is larger than a preset value, the mold shape data correction unit 35 corrects the mold shape data to reduce the height of the entire third setting region u. This correction is performed so that an area including a height difference is set, and the height is lowered by a value sufficiently smaller than, for example, the maximum curvature difference in the area thus set.

  The mold shape data creation system 100 simulates the shape of a press-molded product molded by the mold before performing the series of processes and creates the mold, and the simulation result and the design press. The shape of the mold is determined by comparing with the shape of the molded product. For this reason, since the completeness of a metal mold | die can be raised before producing a metal mold | die, it is not necessary to produce a metal mold again. Therefore, it is not necessary to perform press molding for mold evaluation, and the manufacturing cost can be reduced.

2. Process of Mold Shape Data Creation System FIG. 3 is a diagram schematically showing the process of the mold shape data creation system 100. Design shape data indicating the shape of the designed press-formed product is input to the design shape data input unit 11 (# 01). The material shape data input unit 12 receives material shape data indicating the shape of the material used for press forming (# 02). The material property data input unit 13 receives material property data indicating the properties of the material used for press forming (# 03). Various conditions (press data) relating to press forming are input to the press data input unit 14 (# 04).

  The mold shape data creation unit 21 creates mold shape data using the design shape data (# 05). The post-molding shape data creation unit 23 performs molding simulation using the mold shape data, material shape data, material characteristic data, and press data (# 06). Simulation shape data is created by the molding simulation (# 07). The curvature calculation unit 31 calculates the curvatures of the first setting area s and the second setting area t using the simulation shape data (# 08). Thereby, curvature data related to the first shape data and curvature data related to the second shape data are created (# 09, # 10).

  The curvature difference calculation unit 32 calculates the curvature difference using the curvature data related to the first shape data and the curvature data related to the second shape data (# 11). The correction shape data creation unit 33 creates correction shape data based on the curvature difference (# 12). The mold shape data correction unit 35 corrects the mold shape data for each strain setting region D using the correction shape data (# 13).

  The surface shape data creation unit 34 creates surface shape data so as to approximate the shape of the outer periphery of the correction shape to the shape of the designed press-formed product (# 14). The mold shape data correction unit 35 corrects the mold shape data using the surface shape data so as to approximate the outer periphery of the correction shape to the shape of the designed press-formed product (# 15). Such correction of the mold shape data is repeated until the curvature difference calculated by the curvature difference calculation unit 32 falls within a predetermined threshold. When the curvature difference falls within a predetermined range, the height difference calculation unit 36 calculates the difference between the height of the mold shape data after design and the height of the mold shape data after correction in the third setting region u. Then, height difference correction data is created (# 16). The mold shape data correction unit 35 corrects the mold shape data using the height difference correction data so as to eliminate the height difference (# 17). In this way, the mold shape data creation system 100 can create mold shape data of a mold that can produce a press-molded product equivalent to the designed press-molded product.

3. Correction of Mold Shape Data Using Correction Shape Data and Surface Shape Data Next, correction of mold shape data will be described with reference to the drawings. FIG. 4 is a diagram showing correction of mold shape data when distortion is formed on the surface of a press-molded product obtained by molding simulation with respect to the design shape. (A) shows a part of design shape data of a design door panel (press-molded product). This design shape data is three-dimensional data, and two-dimensional data created by cutting out at a predetermined position of the three-dimensional data is shown in (b). Here, the data shown in (b) is data indicating the outer shape of the door panel, and has an upwardly convex shape.

  (C) shows mold shape data 1 created from the design shape data shown in (b). Further, shape data 2 after press molding obtained by molding simulation using the mold shape data 1 is also shown. Here, distortion is formed on the surface as shown in a circle surrounded by a broken line on the left side, for example.

  (D) is a figure which shows the curvature of the 1st setting area | region s in the 1st shape data in the broken-line circle | round | yen in (c), and the curvature of the 2nd setting area | region t in 2nd shape data. Then, for example, the curvature difference with the first shape data is calculated on the basis of the curvature in the second shape data. Here, if the curvature R1 of the first shape data is -1/8000 and the curvature R2 of the second shape data is 1/12000, the curvature difference is -1/4800. And when this curvature difference shows the maximum value in the distortion setting area | region D which is not shown in figure, the shape data for correction are calculated based on this -1/4800 (maximum curvature difference).

  As shown in (e), at the position corresponding to the strain setting region D of the mold shape data, the maximum curvature difference is calculated as an inverted value 1/4800 obtained by inverting ¼800, and the value of the inverted value is calculated. Correction shape data 4 having the reciprocal as the radius of curvature is given. Then, the die shape data is corrected with a shape (created by the surface shape data creation unit 34) having a curvature R4 of about 1 / 30,000 to 1/200000 on the outer periphery 5 of the shape data for correction. Thus, it becomes possible to manufacture a press-molded product without distortion by correcting the mold shape data by molding simulation.

  Next, height correction will be described with reference to the drawings. FIG. 5 is a diagram showing correction for lowering the height of the third setting area u. A part of the design shape data is shown in (a). This design shape data is indicated by reference numeral 61. The mold shape data created based on the design shape data 61 is indicated by reference numeral 62. Simulation shape data obtained by molding simulation using the mold shape data 62 is also shown. This simulation shape data is indicated by reference numeral 63. As shown by the simulation shape data, a plurality of irregularities are formed on the surface.

  (B) shows the simulation shape data of the die shape data after being corrected so as to eliminate the unevenness included in the simulation shape data 63 shown in (a). The corrected simulation shape data is indicated by reference numeral 63 '. As shown in (b), the height of the simulation shape data 63 ′ in the third setting region u is higher than the height of the mold shape data 62 ′.

  When the maximum value MAX of the difference between the height of the mold shape data 62 and the height of the simulation shape data 63 ′ of the corrected mold shape data is greater than a preset value, as shown in FIG. The mold shape data is corrected with a shape having a curvature larger than the curvature of the mold shape data or the simulation shape data 63 ′ in the 3 setting region u. The mold shape data corrected in this way is indicated by reference numeral 62 ″. In this way, the height of the mold shape data is corrected. The height of the mold shape data can be corrected, for example, by using the above-described large curvature inversion value.

As described above, according to the mold shape data creation system 100, the simulation shape of the press-molded product after press molding based on the design shape data of the press-molded product and the mold shape data generated using the design shape data. Since the data is created and the correction shape for correcting the mold shape data is created using the simulation shape data and the design shape data, the correction shape can be easily created. Therefore, it is possible to reduce the calculation load related to the creation of the correction shape data, so that a high-performance calculation processing device is not required.
In addition, since the mold shape data capable of forming the desired press-molded product is created by bringing the shape of the press-molded product based on the simulation shape data close to the design shape data, the mold shape data system 100 provides the mold shape data. It is possible to create mold shape data of a mold that is optimal for producing a press-molded product having a designed shape with no surface distortion without producing a mold and performing trial punching.

[Other Embodiments]
In the above-described embodiment, when describing the curvature, specific numerical values have been described. However, the scope of application of the present invention is not limited to this. The above numerical values are merely examples, and it is natural that the mold shape data can be created by the mold shape data creation system 100 even if other numerical values are used.

  In the above embodiment, the mold shape data correction unit 35 has been described as correcting data corresponding to the distortion setting region D of the mold shape data using the correction shape data created based on the maximum curvature difference. However, the scope of application of the present invention is not limited to this. Of course, the correction shape data creation unit 33 creates correction shape data for each predetermined first setting region s, and the mold shape data correction unit 35 corrects the data for each predetermined first setting region s. Is possible.

  In the above-described embodiment, the mold shape data correction unit 35 uses the curvature smaller than the curvature of the correction shape in the region where the mold shape data is corrected, to adjust the outer periphery of the correction shape to the design of the press-formed product. It has been described that correction is performed using surface shape data that approximates the shape. However, the scope of application of the present invention is not limited to this. Of course, it is possible to adopt a configuration in which the outer periphery of the correction shape does not approximate the shape of the designed press-formed product.

  In the above embodiment, the mold shape data correction unit 35 is preset with a difference between the height of the mold shape data after the design and the height of the mold shape data after the correction in the third setting region u. It has been described that the mold shape data is corrected when the value is larger than the above value. However, the scope of application of the present invention is not limited to this. Even if the difference between the height of the mold shape data after design and the height of the mold shape data after correction in the third setting area u is larger than a preset value, the mold shape data is corrected. Of course, it is also possible to adopt a configuration without this.

  When the difference between the height of the designed mold shape data and the height of the corrected mold shape data in the third setting area u is smaller than a preset value, the third The third of the mold shape data is based on the curvature of the entire shape of the simulation shape data in the third setting region u, not the shape having a curvature smaller than the curvature of the entire shape of the simulation shape data in the setting region u. It is also possible to correct the data corresponding to the setting area u. Even in such a case, the mold shape data can be appropriately corrected.

  In the above-described embodiment, an automobile door panel is taken as an example of a press-formed product, and creation of mold shape data of the door panel has been described. However, the scope of application of the present invention is not limited to this. Of course, it is also possible to create die shape data of other press-formed products.

  In the above-described embodiment, when the correction of the mold shape data is described with reference to the drawings, it has been described that the shape of the press-formed product is an upwardly convex shape and the unevenness generated with respect to the shape is corrected. However, the scope of application of the present invention is not limited to this. According to the mold shape data creation system 100, the shape of the press-molded product is a downwardly convex shape, and it is naturally possible to correct the unevenness generated with respect to the shape.

  In the above embodiment, the curvature difference calculation unit 32 selects the maximum value of the curvature difference in the distortion setting region D including the plurality of first setting regions s adjacent to each other, sets the maximum curvature difference, and creates correction shape data. The section 33 creates correction shape data based on the maximum curvature difference, and the mold shape data correction section 35 uses the correction shape data created based on the maximum curvature difference to set the distortion setting area D of the mold shape data. It was explained as correcting the data corresponding to. However, the scope of application of the present invention is not limited to this. The correction shape data creation unit 33 creates correction shape data based on the average value of curvature in the strain setting region D, and the mold shape data correction unit 35 creates the correction shape created based on the average value of curvature. Of course, it is possible to adopt a configuration in which data corresponding to the distortion setting region D of the mold shape data is corrected using the data. Even with such a configuration, the correction shape data can be uniquely set and created. Therefore, since the arithmetic processing can be simplified, the mold shape data can be created without using a high-performance arithmetic processing device.

  In the above-described embodiment, the post-molding shape data creation unit 23 performs molding simulation using the die shape data and the press conditions used for manufacturing the press-molded product, and creates simulated shape data as post-molding shape data. As explained. However, the scope of application of the present invention is not limited to this. For example, the post-molding shape data creation unit 23 recognizes the outer shape of a press-molded product manufactured using a mold, measures the outer surface shape, etc. Of course, it is also possible to adopt a configuration for creating post-molding shape data.

  Here, the press-molded product manufactured using a mold is a product actually press-molded using a mold. The creation of the shape data after actual press molding of such a product can be performed as follows, for example. For example, in a press-molded product, the front-rear direction is the X-axis direction, the vertical direction is the Y-axis direction, and the width direction is Z. The post-molding shape data creation unit 23 sets a point group (a set of points indicating Z coordinate values / height values) indicating the surface shape of a press-molded product from a three-dimensional image acquired by an image acquisition unit (not shown). Three-dimensional data is generated by converting into a point group on a lattice point on the XY plane of the pitch. Then, the front-rear direction of the press-molded product is set to the X-axis direction, the vertical direction is set to the Y-axis direction, the width direction (product thickness direction) is set to the Z-axis direction, and the three-dimensional image data value is Generate three-dimensional data values. The point group in the three-dimensional data is a virtual point existing on the surface of the press-molded product, and indicates a point whose position is specified by three-dimensional coordinates.

  The three-dimensional data generated in this way has a data structure in which the height value is expressed as a Z coordinate with reference to an XY plane with a set pitch of less than several millimeters. When this conversion is performed, it is necessary to obtain a height value in an area where the acquired point cloud does not exist.For this process, for example, bilinear method or nearest neighbor method is used. It is possible to newly create a height value reflecting the height value by interpolation processing. By performing these processes, three-dimensional data having a simple data structure in which the height value is indicated in the Z direction with respect to the XY plane is generated. The post-molding shape data creation unit 23 can recognize the outer shape of the press-molded product manufactured in this way, and can create actual post-molding shape data.

  INDUSTRIAL APPLICABILITY The present invention can be used in a mold shape data creation system that creates mold shape data of a mold used when manufacturing a press-formed product.

21: Mold shape data creation unit 23: Post-molding shape data creation unit 31: Curvature calculation unit 32: Curvature difference calculation unit 33: Correction shape data creation unit 35: Mold shape data correction unit 34: Surface shape data creation Part 100: Mold shape data creation system

Claims (5)

A mold shape data creation system for creating mold shape data of a mold for manufacturing a press-molded product,
Based on the design shape data of the press-formed product on the design, a mold shape data creation unit for creating the mold shape data,
A post-molding shape data creation unit for creating post-molding shape data of a press-molded product after molding;
First shape data reflecting the shape of a predetermined first setting area in the shape data after press molding, and predetermined second wider than the first setting area including the first setting area in the shape data after press molding. The second shape data reflecting the shape of the setting region more roughly than the first shape data is acquired, and the curvature of the first setting region in the first shape data and the second setting region in the second shape data A curvature calculator for calculating the curvature of
A curvature difference calculation unit that calculates a curvature difference based on the curvature of the first shape data and the curvature of the second shape data;
A correction shape data creation unit for creating correction shape data of a correction shape based on the curvature difference;
A mold shape data correction unit for correcting the mold shape data based on the correction shape data;
A mold shape data creation system.   The post-molding shape data creation unit performs a molding simulation using the mold shape data and press conditions used for manufacturing the press-molded product, and creates simulation shape data as the post-press-molding shape data. Item 2. A mold shape data creation system according to Item 1. The curvature difference calculation unit calculates a maximum curvature difference using a maximum value of the curvature difference in a distortion setting region composed of a plurality of the first setting regions adjacent to each other,
The correction shape data creation unit creates the correction shape data based on the maximum curvature difference,
3. The data according to claim 1, wherein the mold shape data correction unit corrects data corresponding to a distortion setting region of the mold shape data using correction shape data created based on the maximum curvature difference. Mold shape data creation system. In the region where the mold shape data is corrected, surface shape data that approximates the outer periphery of the correction shape to the shape of the designed press-molded product is created using a curvature smaller than the curvature of the correction shape. It has a surface shape data creation unit,
The mold shape data creation system according to any one of claims 1 to 3, wherein the mold shape data correction unit corrects the mold shape data using the surface shape data.   The mold shape data correction unit sets in advance a difference between the height of the mold shape data after design and the height of the mold shape data after correction in a third setting region composed of a plurality of strain setting regions. Corresponding to the third setting region of the mold shape data based on a shape having a curvature smaller than the curvature of the overall shape of the shape data after press molding in the third setting region when the value is larger than the set value The mold shape data creation system according to any one of claims 1 to 4, wherein data to be corrected is corrected.

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