JP2007313852A - Die correction system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a die correction system which can be used for correcting a die with high dimensional accuracy with ease. <P>SOLUTION: A three-dimension measuring portion 2 asks molded article measured data 21 and die measured data 22, and a corrected amount calculating portion 3 asks a correction point by the calculation of the corrected amount of a die CAD model 12 in accordance with the correction reference point of the die CAD model 12, and the corresponding point of a molded article CAD model 11 corresponding to the correction reference point, the corresponding point of the molded article measured data 21, and the corresponding point of the die measured data 22. A shape correction data creating portion 4 converts the correction reference point and the correction point of the die CAD model 12 into a geometrical data format pair respectively to make the shape correction data 41 of the reference side and the correction side, and a shape correction portion 5 allows the shape correction data 41 of the reference side and the correction side to correspond progressively to correct the shape of the die CAD model 12. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a mold correction system for correcting a mold, and more particularly to a mold correction system for correcting a mold using three-dimensional measurement data.

  As a conventional mold correction system, there is one disclosed in Patent Document 1, for example. In this patent document 1, the closest measurement point between the molded product measurement point and the mold measurement point is searched for, and the amount of deviation is used as a correction amount. Further, a polyhedron is constructed from the point group, and a smooth curved surface is newly generated on the Nerves surface is doing.

  That is, the mold correction system includes a design means for creating a molded product 3D CAD data and a mold 3D CAD data, an actual mold produced using the mold 3D CAD data, and an actual product produced by the mold. A shape measuring means for measuring each shape of the molded product, an alignment means for aligning a measurement result of the molded product obtained by the measuring means with respect to the molded product 3DCAD data, and the above-mentioned measurement result of the molded product. A positional deviation calculation means for calculating positional deviation information with respect to the molded product 3DCAD data, an association means for comparing the molded product measurement result and the mold measurement result to obtain mutual correspondence, and an association means Correction means for correcting the mold measurement result using the correspondence relationship and the positional deviation information, and a correction plate from the mold measurement result corrected by the correction means And a mold 3DCAD data creating means for creating 3DCAD data.

  In this mold correction system, for example, the molded product measurement result is a molded product measurement point group measured at a predetermined interval, and the mold measurement result is a mold measurement point group measured at a predetermined interval. The positional deviation calculation means calculates vector information indicating the deviation amount and the deviation direction with respect to the molded product 3DCAD data for each point of the molded product measurement point group. For each point of the product measurement point group, a point of the mold measurement point group corresponding to the point is obtained, and the mold correction means corresponds to each point of the mold measurement point group. The points of the molded product measurement point group are moved by the amount of the positional deviation calculated by the positional deviation calculating means, and the mold 3D CAD data creating means performs the mold measurement after the correction by the mold correcting means. Polygon model by connecting points in a point cloud Create creates a NURBS surface based on the polygon model is intended to create a modified version mold 3DCAD data based on the NURBS surface.

Japanese Patent Laying-Open No. 2005-199567 (paragraph numbers 0009 and 0012)

The conventional mold correction system is configured as described above, and in the method of Patent Document 1 described above, the closest one between the molded product measurement point and the mold measurement point is searched and the deviation amount is used as the correction amount. There is a problem that there is no guarantee that an appropriate correction amount can be obtained because it depends on the position and number of groups.
In addition, a method of generating a new curved surface from the corrected point group regardless of the original mold curved surface is taken, but in order to create a smooth curved surface over the entire mold, the partial surface is divided by dividing the region. There was a problem that it took a great deal of labor to create and smoothly connect them.
Furthermore, in such a curved surface creation method, there is a problem that there is no guarantee that the design shape and design accuracy of the molded product are maintained.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a mold correction system capable of correcting a mold with high accuracy without taking time and effort.

  The mold correction system according to the present invention is a three-dimensional method for measuring a mold created from a mold CAD model and a shape of a molded article created by the mold to obtain molded product measurement data and mold measurement data. The corresponding point of the molded part CAD model corresponding to the preset correction reference point of the mold CAD model, the corresponding point of the mold measurement data, and the corresponding point of the molded part measurement data are calculated, A molded product error amount is calculated based on the corresponding point of the molded product CAD model and the corresponding point of the molded product measurement data, and the mold error amount is calculated based on the corresponding point of the mold CAD model correction reference point and the molded product measurement data. A correction amount calculation unit for calculating a correction amount of the mold CAD model based on the calculated error amount of the molded product and the mold error amount and calculating a correction point, and a correction reference point of the mold CAD model And the correction point Each mold is converted into a pair of geometric data formats, the shape correction data creating unit for creating the shape correction data on the reference side and the correction side, and the shape correction data on the reference side and the correction side are sequentially associated with each other. And a shape correcting unit for correcting the shape of the CAD model.

  According to the present invention, there is an effect that the mold can be corrected with high accuracy without trouble.

Embodiment 1 FIG.
1 is a block diagram showing a configuration of a mold correction system according to Embodiment 1 of the present invention. The mold correction system includes a three-dimensional design unit 1, a three-dimensional measurement unit 2, a correction amount calculation unit 3, a shape correction data creation unit 4, a shape correction unit 5, and a mold processing unit 6.

  The three-dimensional design unit 1 creates a molded product CAD model 11 and inverts the created molded product CAD model 11 to create a mold CAD model 12 that takes into account production requirements such as shrinkage and draft.

  The three-dimensional measuring unit 2 measures the shape of the actual mold 61 created from the mold CAD model 12 and the molded product 62 created by the mold 61, and the molded product measurement data 21 and the mold measurement data are measured. 22 is determined. These measurement data may be point sequence data obtained by scanning measurement or the like, or random point cloud data obtained by non-contact measurement such as scanning. The point group data is, for example, point group data regularly arranged on a lattice or a curve, or point group data randomly arranged at an arbitrary position.

  The correction amount calculation unit 3 sets the corresponding points of the molded product CAD model 11 corresponding to the preset correction reference points of the mold CAD model 12, the corresponding points of the mold measurement data 22, and the corresponding points of the molded product measurement data 21. And calculating a molded product error amount based on the corresponding point of the molded product CAD model 11 and the corresponding point of the molded product measurement data 21, and based on the corrected reference point of the mold CAD model 12 and the corresponding point of the mold measurement data 22. A mold error amount is calculated, a mold correction amount is calculated based on the calculated molded product error amount and the mold error amount, a correction point of the mold CAD model 12 is obtained, and stored as correction amount data 31.

  The shape correction data creation unit 4 converts the correction reference point and the correction point of the mold CAD model 12 into a pair in the geometric data format, and creates shape correction data 41 on the reference side and the correction side, respectively. In this case, the shape correction data creation unit 4 converts the correction reference point and the point of the correction point to the point, the straight line and the straight line connecting the points, or the curved line and the curved line connecting the points as the geometric data format pair to be converted. Convert. Whether the point, the straight line, or the curve is adopted as the geometric data format pair may be determined according to the shape and accuracy of the target molded product 62.

  The shape correcting unit 5 sequentially associates the reference side and correction side shape correction data 41 to correct the shape of the mold CAD model 12 to create a corrected mold CAD model 51. In this case, the shape correcting unit 5 corrects the shape of the mold CAD model 12 so that the reference-side shape correction data 41 matches the correction-side shape correction data 41.

  The mold processing unit 6 generates NC processing data based on the corrected mold CAD model 51 generated by the shape correcting unit 5 and processes the actual mold 61.

Next, the operation will be described.
FIG. 2 is a flowchart showing processing of the mold correction system according to Embodiment 1 of the present invention. In step ST1, a correction reference point is set on the mold curved surface of the mold CAD model 12 by the designer.

  FIG. 3 is a diagram illustrating an example of correction reference points set by the designer on the mold curved surface of the mold CAD model 12. This setting method may be either CAD interactive operation or automatic calculation by a program. The set correction reference point indicates the reference position before the shape correction, and controls the shape of the mold CAD model 12 after the correction by appropriately setting the arrangement position and the number. In FIG. 3, a part of the mold curved surface of the mold CAD model 12 is represented, but in reality, a correction reference point is set on the mold curved surface of the entire mold CAD model 12.

  In step ST <b> 2 of FIG. 2, the correction amount calculation unit 3 calculates corresponding points on the curved surface of the molded product CAD model 11 corresponding to the correction reference points on the curved surface of the mold CAD model 12 set by the designer. calculate.

  FIG. 4 is a diagram illustrating an example of corresponding points on the molded product curved surface of the molded product CAD model 11 corresponding to the correction reference point on the curved surface of the mold CAD model 12 calculated by the correction amount calculation unit 3. In the example shown in FIG. 4, the correction amount calculation unit 3 uses the intersection of the surface normal vector of the correction reference point on the mold curved surface of the mold CAD model 12 and the molded product curved surface of the molded product CAD model 11 as a corresponding point. It is calculated as

  In step ST3 of FIG. 2, the correction amount calculation unit 3 calculates corresponding points of the mold measurement data 22 corresponding to the correction reference points on the mold curved surface of the mold CAD model 12 set by the designer.

  FIG. 5 is a diagram illustrating an example of corresponding points of the mold measurement data 22 corresponding to the correction reference points on the mold curved surface of the mold CAD model 12 calculated by the correction amount calculation unit 3. In the example shown in FIG. 5, the correction amount calculation unit 3 interpolates the entire mold measurement data 22 with a triangular patch, and the surface normal vector of the correction reference point on the mold curved surface of the mold CAD model 12 and the mold The intersection of the measurement data 22 with the interpolated triangular patch is calculated as the corresponding point of the mold measurement data 22. In this case, the correction amount calculation unit 3 is not limited to interpolation using a triangular patch, but may be interpolated using a free-form surface such as NURBS.

  In step ST4 of FIG. 2, the correction amount calculation unit 3 performs the molded product measurement data 21 corresponding to the correction reference point on the mold curved surface of the mold CAD model 12 set by the designer in the same manner as in step ST3. The corresponding point of is calculated. In this case, the correction amount calculation unit 3 interpolates the entire molded product measurement data 21 with a triangular patch, and calculates the surface normal vector of the correction reference point on the mold curved surface of the mold CAD model 12 and the molded product measurement data 21. An intersection point with the interpolated triangular patch is calculated as a corresponding point of the molded product measurement data 21.

  FIG. 6 is a view for explaining the relationship between the set correction reference point of the mold CAD model 12 and corresponding points of the calculated molded product CAD model 11, mold measurement data 22, and molded product measurement data 21. By performing the processes of steps ST1 to ST4, the molded product CAD model 11, the mold measurement data 22, and the molded product measurement are placed on the normal vector of each correction reference point on the mold curved surface of the mold CAD model 12. The corresponding points of the data 21 are calculated by being aligned. According to this method, the corresponding point of the molded product CAD model 11, the corresponding point of the mold measurement data 22, and the corresponding point of the molded product measurement data 21 always follow the correction reference point of the mold CAD model 12 and the normal vector. Align on top.

In step ST5 of FIG. 2, the correction amount calculation unit 3 calculates the molded product error amount based on the corresponding point of the molded product CAD model 11 calculated in step ST2 and the corresponding point of the molded product measurement data 21 calculated in step ST4. Calculate the mold error amount based on the correction reference point of the mold CAD model 12 set in step ST1 and the corresponding point of the mold measurement data 22 calculated in step ST3, and calculate the molded product error amount. Based on the mold error amount, the correction amount of the mold CAD model 12 is calculated using the following equation to obtain the correction point of the mold CAD model 12 and stored as the correction amount data 31.
Correction amount = (Molded product error amount × Coefficient 1 + Mold error amount × Coefficient 2 + Processing allowance) × Coefficient 3
In the above formula, the finish target value of the molded product 61 can be adjusted by the coefficient 1, the coefficient 2, and the coefficient 3. In this way, the correction amount calculation unit 3 calculates the correction amount of the mold CAD model 12 by performing the processes of steps ST2 to ST5 for all the correction reference points, and sets the correction point of the mold CAD model 12. Ask.

  FIG. 7 is a diagram for explaining the calculated correction amount and correction point of the mold CAD model 12. As shown in FIG. 7, the point moved by the correction amount for which the correction reference point is calculated on the normal vector shown in FIG. 6 becomes the correction point of the mold CAD model 12.

  The modification of the shape of the mold 61 in the present invention is to simultaneously deform the entire mold CAD model 12 so that the correction reference point coincides with the correction point. For this purpose, the set correction reference point and the obtained correction point are used. Need to convert to geometric data format.

  In step ST6 of FIG. 2, the shape correction data creation unit 4 converts the correction reference point into a geometric data format “point” that can be read by CAD, creates the shape correction data 41 on the reference side, and stores it in a file. The data format may be a general-purpose CAD data exchange format such as IGES or STEP, or a data format unique to the CAD system.

  In step ST7, the shape correction data creation unit 4 converts the correction points into a geometric data format called “points” that can be read by CAD in the same manner as in step ST6, and creates the shape correction data 41 on the correction side into a file. Store. The type of geometric data stored in the file is a point, a straight line, or a curve, as in step ST6.

  FIG. 8 is a diagram showing an example of shape correction data. The shape correction data creation unit 4 generates geometric correction data shape correction data 41 as correction reference points and points of correction points, straight lines connecting the points, straight lines, or curves connecting the points as shown in FIG. And convert it to a curve. When converted into a straight line or a straight line or a curved line and a curved line, the straight line part or the curved line part is maintained as it is even after the mold CAD model 12 is deformed.

  In step ST8 of FIG. 2, the shape correction unit 5 uses the reference side shape correction data 41 created in step ST6 and the correction side shape correction data 41 created in step ST7 as points, straight lines, or curves from the beginning of the file. Then, the shape of the mold CAD model 12 is corrected so that the shape correction data 41 on the reference side coincides with the shape correction data 41 on the correction side, and a corrected mold CAD model 51 is created. The shape correction process in step ST8 may be realized using an existing CAD product.

As described above, according to the first embodiment, the three-dimensional measuring unit 2 measures the shape of the mold 61 created from the mold CAD model 12 and the molded product 62 created by the mold 61, The molded product measurement data 21 and the mold measurement data 22 are obtained, and the correction amount calculating unit 3 corresponds to the preset correction reference point of the mold CAD model 12, the corresponding points of the molded product CAD model 11, and the mold measurement data. 22 corresponding points and corresponding points of the molded product measurement data 21 are calculated. Based on the corresponding points of the molded product CAD model 11 and the corresponding points of the molded product measurement data 21, a molded product error amount is calculated. A mold error amount is calculated based on the corresponding reference point of the correction reference point and the mold measurement data 22, and a correction amount of the mold CAD model 12 is calculated based on the calculated molded product error amount and the mold error amount. The shape correction data creation unit 4 The correction reference point and the correction point of the mold CAD model 12 are converted into a pair of geometric data formats, respectively, and the shape correction data 41 on the reference side and the correction side is created. By sequentially matching the shape correction data 41 and correcting the shape of the mold CAD model 12, the position and number of correction reference points can be arbitrarily set according to the desired accuracy. Since the correction can be made at once, there is an effect that the mold can be corrected with high accuracy without taking time and effort.
In addition, this makes it possible to reduce the number of mold corrections and shorten the mold production period.

It is a block diagram which shows the structure of the metal mold | die correction system by Embodiment 1 of this invention. It is a flowchart which shows the process of the metal mold | die correction system by Embodiment 1 of this invention. It is a figure which shows the example of the correction | amendment reference point set on the metal mold | die curved surface of a metal mold | die CAD model in the metal mold | die correction system by Embodiment 1 of this invention. The corresponding point on the molded product curved surface of the molded product CAD model corresponding to the correction reference point on the curved surface of the mold CAD model calculated by the correction amount calculation unit of the mold correction system according to the first embodiment of the present invention. It is a figure which shows an example. It is a figure which shows the example of the corresponding point of the metal mold | die measurement data corresponding to the correction | amendment reference point on the metal mold | die curved surface of the metal mold | die CAD model calculated by the correction amount calculation part of the metal mold | die correction system by Embodiment 1 of this invention. is there. The relationship between the correction reference point of the mold CAD model set in the mold correction system according to the first embodiment of the present invention and each corresponding point of the calculated molded product CAD model, mold measurement data, and molded product measurement data. It is a figure explaining. It is a figure explaining the correction amount and correction point of a mold CAD model calculated by the correction amount calculation unit of the mold correction system according to Embodiment 1 of the present invention. It is a figure which shows an example of the shape correction data in the metal mold | die correction system by Embodiment 1 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 3D design part, 2 3D measurement part, 3 Correction amount calculation part, 4 Shape correction data preparation part, 5 Shape correction part, 6 Mold processing part, 11 Mold CAD model, 12 Mold CAD model, 21 Molding Product measurement data, 22 Mold measurement data, 31 Correction amount data, 41 Shape correction data, 51 Correction mold CAD model, 61 Mold, 62 Molded product

Claims (6)

A three-dimensional measuring unit for measuring a mold created from a mold CAD model and a shape of a molded article created by the mold to obtain molded product measurement data and mold measurement data;
A corresponding point of the molded product CAD model corresponding to a preset correction reference point of the mold CAD model, a corresponding point of the mold measurement data, and a corresponding point of the molded product measurement data are calculated, and the molded product CAD model is calculated. The molded product error amount is calculated based on the corresponding point of the molded product measurement data and the molded product error data, and the mold error amount is calculated based on the mold CAD model correction reference point and the corresponding mold measurement data. A correction amount calculation unit for calculating a correction amount of the mold CAD model based on the calculated molded product error amount and the mold error amount to obtain a correction point;
A shape correction data creation unit that converts the correction reference point and the correction point on the mold CAD model into a geometric data format pair, and creates shape correction data on the reference side and the correction side, and
A mold correction system comprising: a shape correction unit for correcting the shape of the mold CAD model by sequentially corresponding the shape correction data on the reference side and the correction side.   The three-dimensional measuring unit obtains point cloud data regularly arranged on a lattice or a curve, or point cloud data randomly arranged at an arbitrary position as molded product measurement data and mold measurement data. The mold correction system according to claim 1.   When calculating the corresponding points of the mold measurement data and the corresponding points of the molded product measurement data corresponding to the correction reference point of the mold CAD model set in advance, the correction amount calculation unit and the entire mold measurement data and the above The entire molded product measurement data is interpolated with a triangular patch or a free-form surface, and the surface normal vector of the correction reference point of the mold CAD model and the interpolated triangular patch of the mold measurement data and the molded product measurement data or 2. The mold correction system according to claim 1, wherein an intersection with a free space is calculated as a corresponding point between the mold measurement data and the molded product measurement data.   2. The mold correction system according to claim 1, wherein the correction amount calculation unit calculates a mold error amount in consideration of a predetermined coefficient for adjusting a machining allowance of the mold and a finished target value of the molded product. .   The shape correction data creation unit converts the correction reference point and the point of the correction point to a point, a straight line and a straight line connecting the points, or a curved line and a curve connecting the points, as a pair of geometric data format. The mold correction system according to claim 1.   2. The mold correction system according to claim 1, wherein the shape correction unit corrects the shape of the mold CAD model so that the shape correction data on the reference side matches the shape correction data on the correction side.

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