JP2008299489A - Overlapping correction CAD / CAM system - Google Patents

Abstract

[PROBLEMS] To reflect the correction information of a mold corrected by wisdom based on experience by a field technician at a product processing site in remanufacturing, so that the corrected mold can be remanufactured with high accuracy and ease. A type CAD / CAM system is provided.
A CAM system that processes a mold using a metal processing device based on NC data for processing, and a measurement system that acquires measurement point group data by measuring a corrected portion of the mold after processing. 20 and a partial detailed shape processing means 22 for generating the detailed shape model data 5 of the corrected portion from the measurement point group data 4. The CAM system 12 has an overlay interface 24 that inputs the detailed shape model data 5 from the partial detailed shape processing means 22 and superimposes it on the machining NC data 3.
[Selection] Figure 2

Description

  The present invention relates to a superposition correction type CAD / CAM system for remanufacturing a mold corrected on the basis of experience by a field technician at a product processing site.

  Various machine products such as press-molded products are designed for product shape, mold design for making rough products, mold processing, product processing using mold, dimensional tolerance and rough surface density It has been developed through a series of processes such as measurement evaluation. In this series of processes, mold design, generation of NC machining data by the CAM system, and machining of the mold by the NC device are performed based on the shape model design by the CAD system using 3D CAD. In CAM and CAM, the efficiency of design work is improved by using three-dimensional CAD. In the manufacturing department, a CAD system that handles three-dimensional shape data is useful in various respects, such as reducing the number of product manufacturing steps by performing machining using the three-dimensional shape data.

  In the press working of plate materials, in the case of punching dies, it is said that it is important to keep the gap between the pair of blades (clearance) and the distance between the upper and lower dies the same as the plate materials. Relies heavily on the know-how of many years of experience. In addition, the production volume of automobile parts using dies is outstanding, and among them, press dies have a large production value and are said to be the king of dies. Thus, as a means for increasing the production volume of press-formed products, it is conceivable to produce press-formed products at a plurality of production bases. At this time, it is important to prepare the same mold at a plurality of production bases.

  In addition, a deep-drawing die in a press die for an automobile body is also important in die design with respect to a pair of upper and lower dies and a presser foot. The wrinkle presser is necessary not only to prevent the generation of wrinkles but also to give tension to the plate, and it is said that the quality of the molded product is determined by the mold. Is a field that depends on the many years of experience of skilled engineers.

  A press-molded product is produced using a plurality of molds. These molds are processed at the product processing site using on-site technicians who have manually polished or partially shaved the mold surface, that is, on-site modified molds. .

  Patent Documents 1 to 4 have already been disclosed as CAD / CAM systems for the above-described mold design / production. In addition, Non-Patent Documents 1 and 2 have been announced as techniques related to the present invention.

The “NC data creation system” in Patent Document 1 includes an attribute addition system in which attribute marks are added to shape data created by a CAD system, and NC data is created as shape attributes and machining process data corresponding to attribute marks. A CAM system is disclosed. In the CAM system, a tool to be applied is selected in relation to the machining tool according to the machining information of each machining area associated with the attribute mark.
As a result, the machining process corresponding to each machining area can be input under the attribute addition system, which is effective in improving the efficiency from design to production.

According to Patent Document 2, “Information processing apparatus, product assembly process display program, and product assembly process display method”, the design / manufacturing method using three-dimensional CAD is a component compared to conventional drawing-based two-dimensional design. Focusing on the fact that it helps to improve the design efficiency by checking the interference between each other and the product shape visually, and displaying the assembly scene image by acquiring 2D bitmap image data for each part image. The amount of output data for image display is small, and it can be utilized for assembly manufacturing, and the efficiency of assembly man-hours from design is achieved.
However, since the 3D CAD data created by product design cannot be used as it is for assembly manufacturing, it is necessary to edit the 3D CAD data created by product design for assembly manufacturing. Also, 3D CAD data edited for assembly and manufacturing is the 3D CAD data edited for manufacturing when there is a design change in the product design department upstream of the manufacturing process. There is a problem that cannot be reused.

  In “Process Design Support Device” of Patent Document 3, a product designer creates a solid model of a product using a three-dimensional CAD system, creates a product model in which machining accuracy information is set for a machining part, and creates a process model. In order to extract a high-accuracy machining site to be noted, a designer inputs a machining accuracy search condition to retrieve a machining site from the product model, and can add machining attribute information such as an inner diameter and surface roughness. The process designer can set a processing machine, a tool, or the like that processes the processing part while referring to the process constraint condition. This facilitates the design of the machining process.

  In “3D CAD data generation device for manufacturing” in Patent Document 4, manufacturing information data for a change is constructed while comparing with manufacturing information data created based on design-created product 3D CAD data. By providing a 3D CAD data generator for manufacturing that converts to 3D CAD data for manufacturing based on information data, it is possible to easily create assembly process instructions even if there is a design change in the design department. ing.

JP-A-6-143090, “NC data creation system” JP 2003-308545 A, “Information Processing Device, Product Assembly Process Display Program, and Product Assembly Process Display Method” Japanese Patent Application Laid-Open No. 2004-287577, “Process Design Support Device” JP 2005-267475 A, “3-D CAD Data Generation Device for Manufacturing”

Ohtake, Y .; Belyaev, A .; , And Alexa, M .; : "Sparse low-degree implied surfaces with applications to high quality rendering, feature extraction, and smoothing sym5. Ohtake, Y .; , Kanai, T .; , And Kase, K.K. : "A Laplacian Based Approach for Free-Form Deformation of Sparse Low-degree IMlicitative Surfaces", IEEE International Conference on Ships in 203.

As mentioned above, various machine products such as press-molded products are designed for product shape, mold design for making rough products, mold processing, product processing using mold, dimensional tolerance It has been developed through measurement and evaluation of rough surface density and a series of processes.
Further, in the final process of mold manufacturing, it is indispensable that a product is manufactured using the mold at a product processing site, and a skilled field technician modifies the mold.
However, molds that have been polished or shaved by the on-site technicians at the product processing site, that is, molds that have been modified on site, have been used in the processing of products in the past, and the modified molds are modified with photos. Even if a record is left, it has not been possible to reflect the correction information in the reproduction.
Therefore, even when a plurality of the same molds are manufactured, it is necessary to repeat the same correction for each mold.

The above-described prior arts of Patent Document 1 to Patent Document 4 relate to an apparatus that efficiently reflects design changes in the upstream process of the design in the mold design and machining process design of the downstream process, and the CAM system. It could not be reflected in the reproduction.
Therefore, means for remanufacturing molds corrected by wisdom based on experience by field technicians at the product processing site, specifically, `` means for incorporating skills into technology '' by reflecting correction information in remanufacturing, The “means for embodying the rubbing technique” has been strongly desired.

  The present invention has been developed to meet such a demand. That is, the object of the present invention is to reflect the correction information of the mold corrected by wisdom based on experience at the product processing site in the remanufacturing, and to remanufacture the corrected mold with high accuracy and easily. An object of the present invention is to provide a superimposition correction type CAD / CAM system.

According to the present invention, a CAM system for processing a mold using a metal processing apparatus based on NC data for processing,
A measurement system for measuring the correction points of the mold after processing and obtaining measurement point cloud data;
Partial detailed shape processing means for generating detailed shape model data of the correction location from the measurement point cloud data,
The CAM system has an overlay interface for superimposing the detailed shape model data on the machining NC data, and an overlay correction type CAD / CAM system is provided.

According to a preferred embodiment of the present invention, the partial detailed shape processing means includes a shape generation unit and a shape extraction unit,
The shape generation unit includes model data generation means for generating detailed shape model data of the part from the measurement point cloud data of the correction location,
The shape extraction unit includes overlay processing means for overlaying the detailed shape model data of the corrected portion on the machining NC data of the part.

  Further, the model data generating means has shape expression processing means by an implicit function having a local approximate weight average processing function.

According to the overlay correction type CAD / CAM system of the present invention described above, the correction point of the mold after processing is measured by the measurement system by the measurement system to acquire the measurement point cloud data, and the measurement is performed by the partial detailed shape processing means. Detailed shape model data of the corrected portion can be generated from the point cloud data.
Furthermore, since the CAM system has an overlay interface for superimposing the detailed shape model data on the machining NC data, the metal machining apparatus is used to perform the gold processing using the machining NC data and the detailed shape model data superimposed on the machining NC data. The mold can be processed.
Therefore, it is possible to reflect the correction information of the mold corrected by the on-site technicians based on experience at the product processing site in the remanufacturing, and to easily remanufacture the corrected mold.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In each figure, common portions are denoted by the same reference numerals, and redundant description is omitted.

FIG. 1 is an overall configuration diagram of an overlay correction type CAD / CAM system according to the present invention.
This overlay correction type CAD / CAM system corresponds to a series of work processes from product design to product manufacture, and includes a product design system 10, a mold design system 12, a CAM system 14, a mold processing apparatus 16, A product processing apparatus 18 and a measurement system 20 are provided.

In the product design system 10, three-dimensional product shape model data 1 is created and stored in the product shape model DB 11.
In the mold design system 12, a mold and a mold part are designed from the product shape model data 1, and the mold shape model data 2 is stored in the mold shape model DB 13.
The CAM system 14 uses the machining tool DB 15a and the NC data DB 15b to control the mold machining apparatus 16, and processes and manufactures the mold using the metal machining apparatus 16 based on the machining NC data 3.
The product processing apparatus 18 is a press apparatus or an injection apparatus, and processes a product using the manufactured metal mold | die. The product is, for example, a press-molded product or an injection product.

In the product processing by the product processing apparatus 18, when there is a defect (for example, occurrence of wrinkles or cracks), a field technician corrects the defect based on experience in order to eliminate the defect. This correction means is arbitrarily performed based on the experience of field technicians.
The measurement system 20 accurately measures a correction part of the mold after correction processing by a field technician using a CT scan device or the like, and acquires measurement point group data 4. The measurement point cloud data 4 is stored in the measurement point cloud data DB 21.

  In FIG. 1, an input device 8 such as a keyboard / mouse or a display device 9 may be provided for each of the above-described individual systems 10, 12, 14, 20 and processing devices 16 and 18, and these systems may be used. A single input device 8 and display device 9 may be integrated. Further, each system or apparatus shown in FIG. 1 may have a CPU, a processing program, or a memory in which data is stored, or may be realized by a single CPU apparatus.

  In the above-described overlay correction type CAD / CAM system, in the process from product design to mold design, CAM system, mold processing, product processing, and measurement system, each system, through various databases (DataBase: DB), Link devices.

The product shape model DB 11 stores product shape model data 1 created by designing a product shape using a three-dimensional CAD system (product design system 10).
The mold shape model DB 13 stores mold shape model data 2 for manufacturing a product designed by the product design system 10. The mold shape model data 2 is a data group obtained by inverting the product shape model data 1. The mold shape model DB 13 also stores a plurality of mold shape model data 2 and mold part information corresponding to the shape of the product. The mold shape model data 2 is input data to the CAM system 14.

The machining tool DB 15a stores characteristics of cutting tools, drill characteristics, and the like. Further, tool constraint conditions such as the order of use of cutting tools and the order of use of press dies are stored and serve as input information to the CAM system 14.
The NC data DB 15b stores NC data 3 for processing of the metal processing device 16 (a cutting machine such as an end mill or a milling machine). The order of cutting tools according to the cutter path, the cutting speed, the feed speed, and the cutting depth Control data such as is stored.
The measurement point group data DB 21 stores measurement point group data 4 obtained by reading a corrected portion of the manufactured mold with a CT scanning device or the like. The measurement point group data 4 may be local coordinate data of points on the surface of the correction portion of the mold.

The overlay correction CAD / CAM system according to the present invention includes a partial detailed shape processing means 22 and an overlay interface 24 in addition to the CAM system 14 and the measurement system 20 described above.
The partial detailed shape processing means 22 has a function of generating the detailed shape model data 5 of the corrected portion from the measurement point cloud data 4 described above.
The overlay interface 24 is built in the CAM system 14. The overlay interface 24 has a function of inputting the detailed shape model data 5 from the partial detailed shape processing means 22 and superimposing it on the machining NC data 3.

The partial detailed shape processing means 22 includes a shape generation unit 22A and a shape extraction unit 22B.
The shape generation unit 22A has model data generation means for generating the detailed shape model data 5 of the part from the measurement point cloud data 4 of the mold correction location. The model data generating means has shape expression processing means by an implicit function having a local approximate weight average processing function.
The shape extraction unit 22B has means (superposition processing means) for superimposing the detailed shape model data 5 of the mold correction location on the machining NC data 3 of the correction location.

  The partial detailed shape model DB 23 stores the detailed shape model data 5 created by the shape expression processing means using an implicit function that reads the partial shape model data 4 from the measurement point cloud data DB 21 and has a local approximate weight average processing function. ing.

FIG. 2 is a diagram showing the relationship between each system of FIG. 1 and a database.
The partial detailed shape processing means 22 constituting the overlay correction type CAD / CAM system of the present invention uses the partial detailed shape model DB 23 and the measurement point cloud data DB 21. Each system shown in FIG. 1 and FIG. 2 stores and refers to processing result data in each of the databases 11, 13, 15a, 15b, 21, 23 described above.

The overlay correction CAD / CAM system shown in FIGS. 1 and 2 only needs to have a function of handling a solid model that expresses a solid shape by a set operation between solids, and is similar to the function of a conventional solid modeler. It's okay. The mold design system 12, the CAM system 14, the measurement system 20, and the like may use various conventional systems and apparatuses, for example, the systems used in Patent Documents 1 to 4.
The overlay correction type CAD / CAM system of the present invention is configured to be able to cooperate with a conventional CAM system, and the overlay interface 24 controls the cooperation with the CAM system. Specifically, the operation of the overlay correction type CAD / CAM system will be described with reference to FIG. 5 to be described later. The overlay correction type CAD / CAM of the present invention is specified when "superposition processing" is designated from the terminal device. Run the system.

  FIG. 3 shows an example of a mold part, and shows that a correction mark (a point indicated by an arrow from R) is attached to the mold on the screen of the display device.

  FIG. 4 is an example of an overlay management table for performing overlay processing by the overlay correction type CAD / CAM system of the present invention. In this example, the storage locations of the mold shape model data 2 and the partial detailed shape model data 5 before registration are registered corresponding to each overlap location, and the storage locations (Addr1) of the respective shape model data 2 and 5 are registered. , Addr2).

FIG. 5 is an operation flowchart of the overlay correction type CAD / CAM system of the present invention.
In FIG. 5, the CAM system 14 reads the shape model data 2 of the mold or mold part from the mold shape model DB 13 (S1), and displays the mold shape on the display device 9 (S11). Next, the user of the CAM system 14, that is, the CAM designer designates an area for each processing unit with an input device of the display device 9, for example, a mouse (S21). The CAM system 14 obtains the shape model data 2 corresponding to this area (S2, S3). If “superposition processing” is designated from the terminal device in S4 for this area (YES), the processing in S5, S6, and S7 is executed. In this process, the shape extraction unit 22B operates via the overlay interface 24 operating in cooperation with the CAM system 14.

  That is, the shape model data 2 and the partial detailed shape model data 5 of the region corresponding to the overlapping region are extracted from the mold shape model DB 13 and the partial detailed shape model DB 23 and registered in the overlapping management table (S5, S6). . When processing corresponding to a plurality of overlapping locations is completed, an “superimposing attribute value” is also created based on the overlapping management table during this processing, and stored in the mold shape model DB 13. Next, NC data such as a cutting tool, a cutting speed, and a cutting amount is generated corresponding to the high-precision shape model data 4 extracted from the partial detailed shape model DB 23 (S7).

If “superposition processing” is not designated from the terminal device in S4 (NO), NC data such as a cutting tool, a cutting speed, and a cutting amount is generated in accordance with the shape model 2 generated in the die design (S41).
In S8, if the next area is specified (YES), the process returns to S2, and if not (NO), NC data such as a cutting tool, a cutting speed, and a cutting amount is applied to the area not specified in S9. And exit.

FIG. 6 is an operation flowchart of the shape generation unit 22A of the partial detailed shape processing means 22 shown in FIG.
The shape generation unit 22A reads the measurement point cloud data 4 from the measurement point cloud data DB 21 in which the corrected measurement point cloud data 4 of the mold is stored (S51), and features local approximate weight averaging processing for each partial region. The detailed shape model data 5 based on the implicit function is created (S52) and stored in the partial detailed shape model DB (S53).
In the embodiment shown in FIG. 5 and FIG. 6, an example in which shape expression data based on an implicit function is created at a time is shown. However, partial detailed shape model data 5 is required in the process of FIG. A method in which the shape generation unit of the partial detailed shape model generation means operates each time may be used.

  In the following, the shape representation process using an implicit function having a local approximate weight average processing function will be described.

(Implicit function surface as a modeling tool)
In recent years, as a shape expression having a higher degree of freedom, an expression method based on a point is attracting attention. Proceeding this further, a compact implicit volume with a sphere (or elliptical sphere) containing at most a second or third order polynomial (support), with isosurfaces on the surface, positive areas inside, negative The use of a SLIM (Sparse Low-degree IMtricity) curved surface that approximates a surface point group by dispersing a region outside or vice versa in space has been proposed.

The SLIM curve does not necessarily match the topological elements such as vertices and ridgelines at the boundary like the cell inner surface (and volume element partitioned by them) used in conventional triangular patches and finite element meshes (conformant elements). This is a technique that can be numerically analyzed as a non-conforming element.
In addition, since it is not always necessary to align the boundary, it is the mainstream of shape expression, taking advantage of Point Based, which allows you to freely move, transform, and add (the above are basic operations in shape modeling). Shape representation is possible with fewer elements than triangular patches (sectioned linear interpolation: PL). Further, the accuracy of shape expression can be increased by further hierarchical combination.

  By adding and overlapping (covering) Gaussian-like weights so that the spherical supports including the second-order or third-order polynomials, which are in the effective range, are close to zero outside the surface. Can be filled without gaps. Therefore, there are advantages such as topological defects (holes and overlaps), solidity even when a very random triangle set is input, and smoothing when there is measurement noise. .

Although it is a shape expression by a non-conforming covering method, it can be synthesized so as to satisfy the Partition of Unity when the SLIM surface is synthesized (blended using the least square method) (the sum of weights is 1). It is possible to define the integration (discretely sum) of a discrete scalar field or vector field (that is, when a function value is set for each element) so that it can be used as a mesh in various numerical analyses. Is also possible.
By using this method, it is possible to input imperfect solids and (surface and volume) measurement point groups, and it is faster and more intuitive than the commercially available CAD and modeling (expression as an implicit function expression). It is possible to robustly perform set operations that are likely to fail with boundary representation.

(Deformation of SLIM curved surface)
FIG. 7 is a diagram illustrating an example of a SLIM curved surface. Triangular meshes can be used for objects that require a large number of triangles by placing support spheres on the surface and expressing them with a low-order polynomial as shown in this figure. The minimum unit is the triple of the support sphere center, radius, and approximate polynomial.

For example, the center of the support sphere can be the local coordinate origin, and the curved surface in the support sphere can be represented by an implicit function of the equation (1) in an arbitrary orthogonal coordinate system x, y, z.
f (x, y) = z-Q (x, y)
= Z- (Ax ² + By ² + Cxy + Dx + Ey + F)
= 0 (1)
In equation (1), six coefficients A, B, C, D, E, and F are obtained from the coordinates of the measurement point group data 4 of six or more points. Accordingly, the curved surface in the support sphere can be defined by the approximate polynomial of the center, radius, and implicit function of the support sphere.

  FIG. 8 is a diagram showing a flow of processing using the SLIM curved surface. In this example, the smooth Laplacian deformation (moving vertices, which is often used for deforming triangular meshes, but correcting the points that are special compared to the surroundings) to the SLIM surface Applicable.

  Since the SLIM surface does not have an adjoint relationship (phase information) like Point Based, an ad hoc connected graph is created by the inclusive relationship between the support center points each time (FIGS. 8A and 8B). ). Laplace deformation is performed by selecting and moving the center point of the support while maintaining the adjacency relationship (FIG. 8C). At that time, the support is expanded from the sphere to the elliptic sphere for the original SLIM surface. Is locally transformed (FIGS. 8D and 9), and then the polynomial in the support is transformed (FIG. 8E). As a result, the dynamic deformation can be processed in real time while maintaining the detailed shape.

The main features of the shape expression processing by the implicit function having the above-mentioned local approximate weight average processing function are as follows.
(1) Shape representation by implicit function. For example, the detailed shape model data 5 is expressed by three parts: a support (sphere) center position, a radius, and an approximate polynomial.
(2) The local function can be blended.
Decide inside and outside by majority vote. The closer to the center of the territory (sphere), the greater the influence.
(3) A local implicit function can be applied to a binary image.
For example, the detailed shape model data 5 is represented by a quadratic polynomial in a local coordinate system with the center of the sphere as the origin, and a quadratic polynomial having the same number of variables as the dimension is used by the least square method using the measurement point cloud data 2. Can be applied.
(4) Definition of the entire curved surface Where the spheres overlap, blend (weighted averaging).

As described above, in order to create a plurality of dies corrected by wisdom based on experience by field technicians at the product processing site, in the present invention, the shape model of the correction part of the dies corrected by the skill of the skilled worker is used. When the NC data for mold processing is created in the CAM system with high accuracy, the original mold shape model is overlaid at a position corresponding to the correction position.
This makes it possible to “take skills into technology” and approach the concrete realization of “rubbing technology” that is expected to become increasingly important in the future.

  The above description shows an example in which the overlay correction type CAD / CAM system of the present invention is applied when a plurality of dies corrected by wisdom based on experience are created on site by a site technician. However, when producing a small amount of product such as manufacturing a prototype, NC data for directly creating a product is generated using the product three-dimensional shape model as input data without using a mold. In that case, if the input data to the CAM system is switched from the mold shape model DB 13 to the product three-dimensional shape model DB 11, the overlay correction type CAD / CAM system of the present invention can be applied as it is.

By the shape expression processing means by the implicit function of the present invention described above,
(1) The filling of the shape defect portion is possible.
(2) Various shape operations such as Boolean operations (set operations), blending (mixing operations), and morphing are easy.
(3) Surface smoothing is easy.
(4) Sharp features can be expressed,
(5) It has features such as handling large-scale data.
further,
(6) The shape can be filled with high accuracy.
(7) Smoothing of the surface can be performed with high speed and high accuracy.
(8) Useful in that a suitable result can be obtained when expressing a shape having sharp features.

  In addition, this invention is not limited to the Example and embodiment mentioned above, Of course, it can change variously in the range which does not deviate from the summary of this invention.

1 is an overall configuration diagram of an overlay correction type CAD / CAM system according to the present invention. It is a figure which shows the relationship between each system of FIG. 1, and a database. It is a figure which shows the example of metal mold | die components. It is an example of an overlay management table for performing overlay processing by the overlay correction type CAD / CAM system of the present invention. It is an operation | movement flowchart of the overlay correction type | mold CAD / CAM system of this invention. It is an operation | movement flowchart of the shape production | generation part 22A of the partial detailed shape process means 22 shown in FIG. It is a figure which shows the example of a SLIM curved surface. It is a figure which shows the flow of a process of a SLIM curved surface. It is a schematic diagram of an elliptical sphere support.

Explanation of symbols

1 shape model data, 2 mold shape model data,
3 NC data for machining,
4 Measurement point cloud data, 5 Detailed shape model data,
8 input devices, 9 display devices,
10 product design system, 11 product 3D shape model DB,
12 mold design system, 13 mold shape model DB,
14 CAM system, 15a Machining tool DB, 15b NC data DB,
16 mold processing equipment, 18 product processing equipment, 20 measuring system,
21 measurement point cloud data DB, 22 partial detailed shape processing means,
22A shape generator, 22B shape extractor,
24 Overlay interface

Claims (3)

A CAM system for processing a mold using a metal processing device based on NC data for processing;
A measurement system for measuring the correction points of the mold after processing and obtaining measurement point cloud data;
Partial detailed shape processing means for generating detailed shape model data of the correction location from the measurement point cloud data,
The CAM system has an overlay interface for superimposing the detailed shape model data on the machining NC data, and is an overlay correction type CAD / CAM system. The partial detailed shape processing means includes a shape generation unit and a shape extraction unit,
The shape generation unit includes model data generation means for generating detailed shape model data of the part from the measurement point cloud data of the correction location,
2. The overlay correction CAD / CAM according to claim 1, wherein the shape extraction unit includes a superimposition processing unit that superimposes the detailed shape model data of the correction portion on the machining NC data of the part. system.   3. The overlay correction type CAD / CAM system according to claim 2, wherein the model data generation means includes shape representation processing means using an implicit function having a local approximate weight average processing function.

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