JP2009285755A - Method, apparatus and program for supporting machining verification, and memory medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively support a designer so as to achieve more appropriate design change of a product required for removing an unground area. <P>SOLUTION: When the unground area W is calculated by machining simulation, an arrangement range T of an end mill 10 for machining the unground area W is calculated (S63). In addition, the tool arrangement range T is divided into a grid state, and a machine-to-remove amount J of the area W machined by the end mill 10 having its center placed at each grid point and an interference amount K of the end mill 10 and an object to be interfered (44) are calculated for each of the grid points (S67). An area Y to be ground on the object (44) is calculated based on tool arrangement model information obtained by placing the center of the end mill 10 on the optimum grid point op where the machine-to-remove amount J is large and the interference amount K is small among the respective grid points (S73). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method and apparatus for supporting verification of machining of a product based on three-dimensional design data of the product and shape data of a tool for machining the product while rotating around a central axis, and other programs. Etc.

  Conventionally, as shown in Patent Document 1 below, a material representing a three-dimensional shape of a material in an NC data (numerical control data) creation device used when a product is finished in stages with a CAM system (computer-aided machining system) An overlapping portion of the shape bitmap, the tool shape bitmap representing the three-dimensional shape of the tool, and the tool shape bitmap moving along a predetermined tool path and the material shape bitmap is deleted from the material shape bitmap. The processing shape bitmap obtained in this manner and the offset shape obtained by offsetting the three-dimensional shape of the product by a predetermined finishing allowance are created, and the three-dimensional shape of the product is obtained based on the various shapes thus obtained. Extract the uncut area (uncut part) that protrudes more than the above-mentioned finishing allowance from the shape, and this uncut area It has been conducted to create a closed NC data defining a tool path for cutting the inside of the closed region of the contour line.

According to the NC data creating apparatus disclosed in Patent Document 1, NC data (for example, data obtained by changing a tool to be used to a tool having a smaller tool diameter) for automatically cutting an uncut region is automatically created. Therefore, there is an advantage that it is possible to reduce the man-hours conventionally required for checking whether there is an uncut area or creating NC data for cutting the part.
Japanese Patent Laid-Open No. 11-134014

  By the way, in the configuration of the above-mentioned Patent Document 1, even if NC data in which a tool to be used is changed to one having a smaller tool diameter in order to remove the uncut region as described above, depending on the shape of the product, The tool may interfere with a part of the product, leaving a part that cannot be processed. Therefore, in order to remove the uncut region while avoiding such tool interference, it is necessary to make a design change such as reviewing the shape of the product. Since there is no assumption about the case where tool interference occurs, the designer cannot grasp how much interference exists, and the design change of the product cannot be considered easily. It was.

  The present invention has been made in view of the above circumstances, and an object thereof is to effectively support a designer so that a design change of a product necessary for removing an uncut region can be performed more appropriately. And

  In order to solve the above problems, the invention according to claim 1 of the present application is based on three-dimensional design data of a product and shape data of a tool that processes the product while rotating around a central axis. A method for supporting verification related to machining of the product, and performing a machining simulation for moving the tool along a predetermined movement path on model information of the product generated based on the three-dimensional design data, A step of calculating an uncut area that cannot be machined by the tool due to interference between the tool and a part of the product, and an uncut area is calculated in this step; A step of expanding in a plane by the radius and calculating at least a part thereof as a tool placement range; dividing the tool placement range into a grid shape; Calculating the machining removal amount of the uncut region and the amount of interference between the tool and the interfered object for each grid point, and the machining among the grid points. A step of obtaining an optimum lattice point having a large removal amount and a small interference amount, and calculating a cutting region generated in the interfered object based on tool placement model information obtained by placing a tool center at the optimum lattice point. It is characterized by including these.

  According to the first aspect of the present invention, when the uncut area is calculated as a result of the machining simulation of the product, the tool arrangement range for machining the uncut area is calculated, and the tool arrangement range is Among the lattice points obtained by dividing the lattice, the optimum lattice point having a large amount of machining removal in the uncut region and a small amount of interference with the interfered object is obtained. The cutting area generated in the interfered object can be suppressed to the smallest possible range while efficiently removing the uncut area by the arranged tool. Then, the designer who knows the existence of the cutting area calculated in this way shifts the position of the interfered object by the amount of the cutting area, etc. Since generation | occurrence | production can be eliminated, a required design change can be performed easily and appropriately.

  In the present invention, the tool arrangement range is a range obtained by excluding a region where the interference of the tool with a portion where the design cannot be changed from a region obtained by planarly expanding the uncut region by the radius of the tool. It is preferable to set to (Claim 2).

  According to this configuration, it is possible to reliably prevent a part that cannot be changed in design from interfering with the tool and cutting, and there is an advantage that the product can be processed with the tool more appropriately.

  There is no particular limitation on the type of product that is subject to verification support of the present invention. However, the present invention is, for example, a mold holder for holding a mold part for press molding, and processing by the tool. This can be suitably applied to the case where the seat surface processed portion serving as the mounting seat for the press-molding die part is included in the object of (3).

  In other words, according to this configuration, it is possible to effectively prevent the uncut region from being generated in the seat surface processed portion that requires flatness in order to hold the mold part firmly. There is an advantage that the mold part can be appropriately held by using a mounting seat made of a processed portion.

  Further, the invention according to claim 4 of the present application relates to the calculation for performing the verification related to the machining of the product, the three-dimensional design data of the product, and the shape of the tool that processes the product while rotating around the central axis. A machining verification support program to be executed by a computer based on the data, wherein the tool is moved along a predetermined movement path with respect to product model information generated based on the three-dimensional design data. A step of performing simulation to calculate an uncut area that cannot be machined by the tool due to interference between the tool and a part of the product, and when the uncut area is calculated in this step, the uncut area Expanding in a plane by the radius of the tool and calculating at least a part thereof as a tool placement range; and Dividing the machining removal amount of the uncut region to be machined by a tool that is divided and centered at each lattice point, and calculating the interference amount between the tool and the interfered object for each lattice point; Among the lattice points, an optimum lattice point having a large machining removal amount and a small interference amount is obtained, and the interfered object is obtained based on tool placement model information obtained by placing a tool center at the optimum lattice point. And a step of calculating a shaving area generated in step (b).

  According to a fifth aspect of the present invention, there is provided a storage medium storing the machining verification support program according to the fourth aspect.

  Further, the invention according to claim 6 is calculated by the storage medium according to claim 5, a calculation means for performing calculation according to the machining verification support program stored in the storage medium, and the calculation means. A machining verification support apparatus, comprising: display means for displaying an image of the cutting area.

  According to the inventions according to the fourth to sixth aspects, as in the invention according to the first aspect, the designer can effectively perform the design change necessary for removing the uncut region. There is an advantage of being able to support.

  In the invention of claim 6, it is preferable that the display means displays the cut area in a color different from the design data of the product (claim 7).

  According to this configuration, since the presence of the cutting area can be easily identified, there is an advantage that a design change necessary for eliminating the cutting area can be easily considered.

  As described above, according to the present invention, the designer can be effectively supported so that the design change of the product necessary for removing the uncut region can be performed more appropriately.

  FIG. 1 is a block diagram showing a schematic configuration of a machining verification support apparatus 1 according to an embodiment of the present invention. The machining verification support apparatus 1 shown in the figure includes an input unit 2 including a keyboard and a mouse that accepts an input operation by an operator, three-dimensional design data of a product created in advance by a three-dimensional CAD, Based on storage means 3 (corresponding to a storage medium according to the present invention) composed of an HDD (hard disk) or the like for storing tool shape data and the like used for machining the product, and on the product design data and tool shape data, etc. The calculation means 4 composed of a CPU or the like for calculating the uncut area (details will be described later) during machining of the product, and the uncut area calculated by the calculation means 4 is read from the storage means 3. Display means 5 comprising a liquid crystal display or CRT for displaying an image together with the design data of the product. The storage means 3 stores a calculation program that defines the contents of the calculation executed by the calculation means 4, and the calculation means 4 executes the calculation according to the calculation program stored in the storage means 3. Thus, the uncut region is calculated.

  That is, in the above configuration, when the operator performs a predetermined input operation on the input means 2, the design data of the product designated by the input operation and the shape data of the tool used for processing the product are stored in the memory. It is read from the means 3 and input to the calculation means 4, and in the calculation means 4, predetermined calculation processing based on the product design data and the tool shape data is executed and calculated by the calculation. The uncut region is displayed on the display unit 5 together with the design data of the product.

  FIG. 2 is a diagram showing a shape of an end mill 10 as an example of the tool. As shown in this figure, the end mill 10 has a substantially cylindrical main body portion 12 having cutting edges at a tip end portion 12a and an outer peripheral portion 12b, and chucks (holds) the main body portion 12 on a machine tool not shown. The holder 13 is configured to cut the workpiece while being rotationally driven around the central axis (Z axis) by a predetermined driving mechanism provided in the machine tool. In the following description, it is assumed that the Z axis serving as the center of rotation of the end mill 10 is the vertical axis (vertical axis), and the end mill 10 is used in a posture in which the tip end portion 12a is vertically downward.

  The type of product to be verified by the machining verification support apparatus 1 is not particularly limited. In the present embodiment, the product is a press molding die or its peripheral parts (hereinafter collectively referred to as press molding). It is a casting mold holder 20 for holding a mold part), and a case where the mold holder 20 is processed by the end mill 10 is verified. FIG. 3 shows a state in which a part of the mold holder 20 is three-dimensionally displayed on the display means 5. The mold holder 20 shown in this figure is a machining section processed by the end mill 10, and a seat surface processing section 22 that serves as a mounting seat for the mold part when the press mold part is held. Each side has a side processing part 24 and the like for abutting the side surfaces of the respective parts of the mold to perform positioning and the like. Further, a cast part 26 that is not processed by the end mill 10 (that is, as-cast) is formed at a place other than each machining part such as the seating surface processing part 22 and the side surface processing part 24. In the present embodiment, the machined portion (such as the seating surface processing portion 22 and the side surface processing portion 24) is colored in a color different from that of the casting portion 26 in order to facilitate identification. Is displayed.

  The mold holder 20 is an end mill in a state where the surface of the seating surface processing portion 22 is held in a posture orthogonal to the rotation axis (Z axis) of the end mill 10 (that is, a posture in which the seating surface processing portion 22 is horizontal). 10 is processed. That is, at the time of machining the mold holder 20, the seating surface processing portion 22 is cut by the tip portion 12 a of the end mill 10, while the side surface processing portion 24 is cut by the outer peripheral portion 12 b of the end mill 10.

  Next, the contents of the arithmetic processing executed in the arithmetic means 4 will be described based on the flowcharts shown in FIGS.

  When the calculation start by the calculation means 4 is instructed in response to a predetermined input operation on the input means 2 and the flowchart of FIG. 4 starts, the calculation means 4 reads a necessary calculation program from the storage means 3 (step S1). Similarly, a process of reading the specific design data designated by the input operation from a plurality of design data related to the mold holder 20 stored in the storage means 3 is executed (step S3).

  Next, the calculation means 4 executes a process for generating polyhedron model information in which the shape of the mold holder 20 is polyhedral based on the three-dimensional design data of the mold holder 20 read from the storage means 3 (step) S5). That is, as shown in FIG. 9, the surface of the three-dimensional shape of the mold holder 20 (in FIG. 9, the surface of the local curved portion of the mold holder 20 is represented) is used as a planar element. The polyhedron is replaced with an aggregate of polygons 30, 30..., And shape information generated through such processing is acquired as the polyhedron model information. In the example shown in the figure, a triangular polygon is used as the polygon 30. However, it is naturally possible to use a polygon having another shape such as a quadrangle.

  Next, the calculation means 4 proceeds to step S7 in FIG. 4 and executes a process of generating error-containing model information by adding a shape error (casting error) at the time of casting to the polyhedral model information of the mold holder 20 described above. To do. FIG. 6 is a subroutine showing the specific contents of the error-containing model information generation process executed in step S7. As shown in the figure, when this subroutine is started, the calculation means 4 first uses the polyhedron model information of the mold holder 20 to preset the shape of the casting portion 26 in the model information. Then, a process of expanding (expanding) by the casting error is executed (step S41).

  The process in step S41 will be described for the case where the cast part 26 has a shape as shown in FIG. In the example of FIG. 10, it is assumed that the casting portion 26 has two flat surfaces 26a and 26b that intersect substantially vertically. If the upper limit value of the casting error is ε (for example, about 10 mm), the process of step S41 is performed on the cast part 26 having the above shape, as shown by a two-dot chain line in the figure. Further, the outer shape of the casting part 26 is greatly expanded by the amount corresponding to the casting error ε. In FIG. 10, the seating surface processing portion 22 is disposed adjacent to the casting portion 26, but processing for expanding (expanding) the machining portion such as the seating surface processing portion 22 will be described later. .

  Specifically, in order to expand the shape of the casting part 26 by the casting error ε, the casting part 26 is made to be inflected as shown in FIGS. 11 and 12 using the polyhedron model information of the casting part 26. Cylinders and spheres having a radius of the casting error ε are arranged at the vertices and sides corresponding to the peripheral portions of the planes 26a and 26b among the vertices and sides of the plurality of polygons 30. A polygonal thick plate having a thickness twice as large as the casting error ε is arranged in a region surrounded by. As a result, the shape information of the cast portion 26 is expanded three-dimensionally by the casting error ε, and is converted into a larger shape including the casting error ε. And such a process is performed similarly with respect to all the other casting parts 26 in the said mold holder 20. FIG.

  Next, the calculation means 4 proceeds to step S43 in FIG. 6 and changes the shape of the machined portion including the seating surface processing portion 22 and the side surface processing portion 24 of the mold holder 20 by the casting error ε. Execute the expansion process.

  A case will be described in which the processing in step S43 is applied to the seating surface processing portion 22 having a shape as shown in FIG. In order to expand the shape of the seating surface processing portion 22 by the casting error ε, as shown by the two-dot chain line in FIG. 13, the apexes and sides of the polygons 30 constituting the seating surface processing portion 22 are expanded. Among them, a circle (fan shape) having a radius of the casting error ε and a rectangle having a width ε are respectively arranged at the apex and the side corresponding to the peripheral portion of the seating surface processing portion 22. As a result, the shape information of the seating surface processing portion 22 is expanded in a plane by the casting error ε, and is converted into a larger shape including the casting error ε. Such processing is similarly performed on all the other seating surface processing portions 22 in the mold holder 20. In FIG. 13, the case where the above-described extension process is performed on the seating surface processing unit 22 has been described. However, other machining units such as the side processing unit 24 are also subjected to the same procedure as described above. Expansion processing can be performed.

  Further, in FIG. 13, the extension process executed when the machining unit such as the seating surface processing unit 22 is a flat surface has been described. However, even when the machining unit is a curved surface, a polyhedron (a set of planes) By expanding the machining portion using the shape information as shown in FIG. 9 converted into (), it is possible to perform the expansion process basically in the same procedure as described above.

  When the expansion process of each part is completed in this way, the calculation means 4 then proceeds to step S45 in FIG. 6 and the shape information after the expansion process of the cast part 26 and the machined part (seat surface) A process of combining the shape information after the expansion process of the processing unit 22 and the side processing unit 24) is executed.

  For example, in the case where the upper surface of the prismatic model as shown in FIG. 14 is the seating surface processing portion 22 and the other four side surfaces are the casting portion 26, the shape information after the expansion processing of the casting portion 26 (FIG. a) (see the two-dot chain line in a)) and the shape information (see the two-dot chain line in FIG. 2 (b)) of the seating surface processed portion 22 after the expansion process, A portion protruding above the processing portion 22 is removed, and as a result, shape information as shown by a two-dot chain line in FIG.

  Next, the calculation means 4 proceeds to step S47 in FIG. 6 and executes a process of combining the shape information after the expansion process for each machining part such as the seating surface machining part 22 and the side surface machining part 24. .

  For example, when the upper surface of the prismatic shape model as shown in FIG. 15 is the seating surface processing unit 22 and one of the four side surfaces is the side surface processing unit 24, the shape of the seating surface processing unit 22 after the expansion process When the information (see the two-dot chain line in FIG. 1A) and the shape information after the extension processing of the side surface processing unit 24 (see the two-dot chain line in FIG. 1B) are combined, the expansion of the seating surface processing unit 22 is performed. A portion (A portion) protruding sideward from the side surface processed portion 24 in the region is removed, and a portion (B portion) protruding upward from the seat surface processed portion 22 in the extended region of the side surface processed portion 24. As a result, shape information as shown by a two-dot chain line in FIG.

  When the generation of the error-containing model information (step S7 in FIG. 4) is completed through the processes in steps S41 to S47 as described above, the calculation unit 4 proceeds to the next step S9 and selects the verification tool. Execute the process. That is, the calculation means 4 determines the type of tool to be used for the current machining from a plurality of tools stored in the storage means 3 (FIG. 1) according to a predetermined priority order determined in advance. Execute.

  Specifically, in the storage means 3, the shape data of the plurality of end mills 10 are classified and stored for each type of machined part (seat surface, side surface, hole, groove, etc.) that can use the end mill 10. Each of these data is prioritized based on a predetermined standard. Then, the computing means 4 uses the end mill 10 that is as high as possible according to the above priority order from among the end mills 10 that can be used for the machined portion of the model that is the subject of verification in the current processing flow. Determine as. The priority order can be determined based on, for example, the diameter of the end mill 10. That is, even when machining the same part, it is more advantageous in terms of machining speed and accuracy to use the end mill 10 having a diameter that is as large and as rigid as possible. The tool can be selected in consideration of the following points.

  When the tool selection process is completed in this way, the calculation means 4 then proceeds to the end mill based on the error-containing model information obtained in step S7 and the shape information of the end mill 10 selected in step S9. 10 is executed to calculate a remaining uncut region as a region that cannot be cut when machining is performed using step 10 (step S11).

  FIG. 7 is a subroutine showing the specific contents of the uncut region calculation process executed in step S11. As shown in this figure, when this subroutine is started, the calculation means 4 first moves the reverse shape of the selected end mill 10 along the surface of the error-containing model information obtained in the above step S7. Processing for obtaining the sweep shape is executed (step S51).

  The processing in step S51 is performed by changing the error-containing model information to a cross-sectional shape model as indicated by reference numeral 20A in FIG. 16, that is, the casting portion 26 protruding upward (+ Z direction), and the height lowered by one step. An example of calculating a remaining uncut region that can be generated when the seat milling portion 22 of the model is cut by the end mill 10 will be described. In this case, the calculation means 4 maintains the center of the tip 12a (FIG. 2) of the end mill 10 on the surface of the error-containing model information 20A, while reversing the shape of the end mill 10 (reversing the Z axis). 17) is moved along the surfaces of the casting part 26 and the seating surface processing part 22, and as shown in FIG. 17, the reverse shape of the end mill 10 is three-dimensionally accumulated along the movement trajectory. The sweep shape S is obtained.

  Next, the calculation means 4 proceeds to step S53 in FIG. 7 and applies a reverse offset process to the sweep shape S obtained in step S51, so that a tool in the Z map model format as shown in FIG. A process for generating the movement path plane R is executed.

  Specifically, the reverse offset processing for generating the tool movement path surface R in the Z map model format is as follows. That is, first, a sufficiently fine orthogonal lattice is prepared on the XY plane, a straight line parallel to the Z-axis direction is extended from each lattice point, and this straight line and the upper surface of the sweep shape S obtained in step S51 are described above. Is calculated to obtain a dense point group covering the upper surface of the sweep shape S. And the tool movement path | route surface R of the Z map model format which consists of an aggregate | assembly of the polygon which made the said point group the vertex is produced | generated by interpolating the clearance gap of the said point group with a polygon. For reference, FIG. 19 shows a tool movement path surface R ′ in the Z map model format that is obtained when the above-described reverse offset process is performed on a sweep shape whose upper surface has an upwardly convex curved surface. .

  Next, the computing means 4 executes a machining simulation process for moving the end mill 10 in a normal posture (a posture with the tip 12a downward) along the tool movement path plane R obtained in step S53 (step S55). . Specifically, the tool movement path is set by following the point group on the tool movement path plane R in order in the X-axis and Y-axis directions (in a polygonal line), and the end mill 10 is moved along the movement path. Let As a result, as shown in FIG. 20, the movement trajectory of the end mill 10 obtained when the seating surface processing portion 22 is processed while moving the end mill 10 within a range that does not interfere with the outer shape of the error-containing model information 20A is obtained.

  When the movement trajectory of the end mill 10 is obtained in this way, the computing means 4 next calculates the Z value (coordinate value in the Z-axis direction) of the tip 12a of the end mill 10 located on the movement trajectory and the seat. Based on the difference from the Z value of the surface machining section 22, a process of calculating an uncut region W (FIG. 20) as a region remaining without being processed by the end mill 10 is executed (step S57). That is, since there is a machining allowance of a predetermined thickness on the seating surface processing portion 22 formed of the seating surface after machining, the tip end portion 12a of the end mill 10 positioned on the movement locus and the seating surface processing portion 22 are provided. If there is a gap in the Z-axis direction, the part of the machining allowance remains without being cut by that gap, and the remaining area is calculated as the uncut area W. In the example shown in the drawing, due to the interference between the holder part 13 of the end mill 10 and the casting part 26, the tip of the end mill 10 is placed on the edge of the upper surface part of the seating surface processing part 22 on the side close to the casting part 26. There is a region where the part 12a cannot reach, and this region is calculated as the uncut region W. On the other hand, in FIG. 20, the seat surface processing part 22 is displaced in the direction away from the casting part 26 from the position shown in the figure, or the diameter of the end mill 10 including the holder part 13 is smaller than that shown in the figure. When the interference of the end mill 10 does not occur, the uncut region W does not occur.

  When the calculation of the uncut region W (step S11 in FIG. 4) is completed through the processes in steps S51 to S57 as described above, the calculation unit 4 next determines whether or not the uncut region W exists. Is executed (step S13). If it is determined YES in this case and it is confirmed that the uncut region W exists, the process proceeds to the next step S15, and the uncut region W is combined with the design data of the mold holder 20. The process of displaying on the display means 5 (FIG. 1) is executed. FIG. 21 shows a state in which the design data of the mold holder 20 and the uncut region W are actually displayed on the display means 5. As shown in the figure, the uncut region W is colored in a color different from the display color of the mold holder 20 including the seating surface processing portion 22 and the casting portion 26 in order to facilitate the identification. Is displayed.

  Next, an example in which the uncut material region W is calculated for another part of the mold holder 20 will be described with reference to FIGS. FIG. 22 shows a state in which a part different from the part shown in FIGS. 16 to 21 is displayed on the display means 5 in the mold holder 20. The mold holder 20 shown in the figure includes a planar lower step portion 40, an upper step portion 42 that protrudes upward from the lower step portion 40, and a circular protrusion protruding from the bottom portion 40. 44. The upper step portion 42 is formed with a side surface processing portion 24 formed of a part of the side wall and a seat surface processing portion 22 located at a lower end portion of the side surface processing portion 24. The side processed portion 24 is cut by the tip portion 12a and the outer peripheral portion 12b (FIG. 2) of the end mill 10, respectively. In the display area of the display means 5, all surfaces other than the processed parts 22, 24 are all as-cast parts 26.

  FIG. 23 shows error-containing model information 20A corresponding to the mold holder 20 shown in FIG. In the example of FIG. 23, it can be seen that the end mill 10 interferes with the protrusion 44 when the seating surface processed portion 22 is processed by the tip portion 12 a of the end mill 10. For this reason, the tip 12a of the end mill 10 cannot reach the height position of the seating surface processing portion 22, and the region between the end mill 10 and the seating surface processing portion 22 cannot be cut by the end mill 10. An uncut region W is generated.

  FIG. 24 shows a state in which the uncut region W calculated as described above is displayed on the display means 5. As shown in the drawing, the uncut region W is displayed in a different color on the upper side of the seating surface processing portion 22. A two-dot chain circle shown in FIG. 24 indicates the tip 12a of the end mill 10 when it is brought close to just before it interferes with the outer shape of the protrusion 44. That is, according to such a positional relationship, a predetermined range including a region located within the circle of the two-dot chain line in the seating surface processing portion 22 can be cut by the tip portion 12a of the end mill 10. However, in other areas, it is not possible to perform cutting with the end mill 10 unless a predetermined measure such as changing the position of the projection 44 or using a smaller end mill 10 is taken. It can be seen that the generation of the uncut region W corresponding to the region cannot be avoided.

  Returning to the flowchart of FIG. 4 again, the continuation of the processing by the computing means 4 will be described. When the processing for displaying the uncut region W on the display unit 5 is completed in step S15, the calculation unit 4 confirms whether or not the design of the portion where the uncut region W is generated can be changed. In order to prompt the user, a process of displaying a predetermined confirmation message on the display means 5 is executed (step S17). That is, even if the position and shape of the seating surface processed portion 22 (or the entire upper step portion 42) of the upper step portion 42 where the uncut region W is generated, the function of the mold holder 20 is not particularly affected. In such a case, the occurrence of the uncut region W can be avoided by changing the design of the part, so it is confirmed with the designer whether or not such a measure is possible.

  Next, the calculation means 4 determines whether or not the design change of the portion where the uncut region W is generated is possible according to the result of the input operation by the designer (step S19), where YES is determined. When it is confirmed that the design change is possible, after waiting for the designer to correct the design data, a process of reading the design data of the corrected mold holder 20 is executed ( Step S20). Then, for the mold holder 20 whose design has been changed in this way, the processing after step S5, that is, the processing for generating the polyhedron model information and the error-containing model information and calculating the uncut region W based on the processing, Execute in the same procedure as

  On the other hand, when it is determined NO in Step S19 and it is confirmed that the design change of the portion where the uncut region W is generated is impossible, the calculation unit 4 proceeds to Step S21 in FIG. When the unmilled area W is machined by the end mill 10, a process of calculating a shaving area caused by the interference of the end mill 10 is executed. Below, the case where such a process is performed with respect to the mold holder 20 of a shape as shown in FIGS. 22-24 is mentioned as an example, and is demonstrated.

  FIG. 8 is a subroutine showing the specific contents of the cutting area calculation process executed in step S21. As shown in this figure, when this subroutine is started, the calculation means 4 first executes a process for calculating the maximum tool arrangement range Ta shown in FIG. 25 (step S61). Specifically, the maximum tool arrangement range Ta is arranged such that a circle corresponding to the tip portion 12a of the end mill 10 is arranged in a state in which the center coincides with the outline of the uncut region W, and makes a round on the outline. It is obtained as a locus (region) when the end mill 10 is moved. That is, in order to machine the contour line of the uncut region W, the region within the tool radius r from the contour line (that is, the region where the uncut region W is planarly expanded by the radius r of the end mill 10). Since the center of the end mill 10 only needs to be present, the arrangement range of the end mill 10 in which the uncut part W can be partially processed by calculating the maximum tool arrangement range Ta according to the procedure described above. Can be sought.

  Next, as shown in FIG. 26, the calculation means 4 removes the region within the tool radius r from the side wall around the uncut region W from the maximum tool placement range Ta, and obtains the region obtained thereby by the tool placement. Processing for calculating the range T is executed (step S63). That is, as described above, as a precondition for the execution of the subroutine (cutting area calculation process) in FIG. 8, the part where the uncut area W is generated (that is, the seating surface processing part 22 of the upper stage part 42 and its peripheral part). Therefore, when the unmilled region W is processed and removed by the end mill 10, the end mill 10 interferes with the side surface processed portion 24 of the upper step portion 42 or the like. Unacceptable. Therefore, by removing the region within the tool radius r from the side wall of the upper stage portion 42 such as the side surface processing portion 24 from the maximum tool arrangement range Ta, the interference of the end mill 10 to the portion where the design cannot be changed as described above. A tool arrangement range T that can be avoided is obtained. If there is no part that cannot be changed in design around the uncut region, the maximum tool placement range Ta is calculated as it is as the tool placement range T.

  Next, the calculation means 4 executes a process of dividing the tool placement range T obtained as described above into fine orthogonal lattices as shown in FIG. 27 (step S65). Then, the center of the end mill 10 is arranged at each lattice point, and the amount of machining removal J of the uncut region W at that time and the amount of interference K between the end mill 10 and the projection 44 (interfering object) that interferes with the end mill 10. Are stored in the storage means 3 (FIG. 1) in association with each grid point in the tool arrangement range T (step S67). For example, when the centers of the end mills 10 are arranged at two lattice points a and b shown in FIG. 27, the machining removal amount J and the interference amount K at this time are arranged at the lattice points a and b. As an area or a volume of an overlapping portion (a portion indicated by hatching) between the end mill 10 and the uncut region W and a overlapping portion (a portion indicated by hatched hatching) between the end mill 10 and the projection 44 when being done Calculated.

  When the processing removal amount J and the interference amount K for each lattice point are obtained in this way, the calculation means 4 proceeds to the next step S69, where the processing removal amount J is large and the interference amount K is small. A process of specifying a point in association with each point on the outline of the uncut region W is executed. Specifically, first, as shown in FIG. 28, a large number of points are set on the outline of the uncut region W at a fine pitch, and the center is located at one of these points (for example, point p in the figure). Thus, after arranging the tip 12 a of the end mill 10, an overlapping portion T ′ between the tip 12 a of the end mill 10 and the tool placement range T is obtained. If the end mill 10 is arranged so that the center exists in the overlapping portion T ', the point p of the uncut region W can be removed without fail. Therefore, in order to identify a more appropriate location of the end mill 10 among them, after reading the processing removal amount J and the interference amount K from the storage means 3 for all the lattice points in the overlapping portion T ′, From these, the optimum lattice point (indicated by op in the figure) is specified where the machining removal amount J is as large as possible and the interference amount K is as small as possible. FIG. 29 shows a state in which the center of the end mill 10 is arranged at the optimum lattice point op. By disposing the center of the end mill 10 at such an optimal lattice point op, the interference between the end mill 10 and the protrusion 44 is made while the processing removal amount J of the uncut region W processed by the end mill 10 is made as large as possible. The amount K can be suppressed to a smaller value.

  The optimal grid point op is identified by first determining whether or not the grid point with the maximum processing removal amount J matches the grid point with the minimum interference amount K. The lattice point is specified as the optimum lattice point op. On the other hand, if the two do not match, the grid point at which either one of these quantities J or K is the maximum is specified as the optimum grid point op, depending on which of the processing removal quantity J and the interference quantity K has priority. Or a lattice point in the middle may be specified as the optimum lattice point op. The specific method can be appropriately changed by weighting the machining removal amount J and the interference amount K according to the design conditions and the like.

  Then, by specifying the optimum grid point op as described above similarly for other points (points other than the point p) on the outline of the uncut region W, all the points corresponding to all the points on the outline are obtained. The optimal grid point op is specified.

  When the identification of all the optimum grid points op is completed in this way, the calculation means 4 arranges the centers of the end mills 10 at all the optimum grid points op, and the union of the shapes of the arranged end mills 10. A process of calculating tool placement model information (that is, approximately the same as the sweep shape of the end mill 10 when passing through the optimum path for eliminating the uncut region W) is executed (step S71). And by calculating | requiring the overlapping part (product set) of this tool arrangement | positioning model information and the projection part 44 in the said error content model information 20A, the said projection part 44 as an interfered object is processed as an area | region by the end mill 10. A process of calculating the cutting area Y (see FIG. 30) is executed (step S73).

  When the calculation of the cutting area Y (step S21 in FIG. 5) is completed through the processes of steps S61 to S73 as described above, the calculation means 4 proceeds to the next step S23, and the cutting area Y A process of displaying Y on the display unit 5 together with the design data of the mold holder 20 is executed. FIG. 30 shows a state in which the design data of the mold holder 20 and the cutting area Y are actually displayed on the display means 5. As shown in this figure, the cut-out area Y is displayed in a state of being colored in a color different from the surrounding display color in order to facilitate identification. In FIG. 30, the uncut region W that has been removed by machining and the uncut portion is eliminated is indicated by a virtual line, but this indicates that the uncut portion has been eliminated. Is displayed as semi-transparent.

  Next, the calculation means 4 executes a process of displaying a predetermined confirmation message on the display means 5 in order to prompt the designer to confirm whether or not the design of the portion where the cutting area Y is generated can be changed. (Step S25). That is, when it is possible to change the position and shape of the projection 44 where the cut region Y is generated, the change in the design of the projection 44 can eliminate the generation of the cut region Y. Check with the designer to see if appropriate measures are possible.

  Then, the calculation means 4 determines whether or not the design change of the portion (projection 44) where the cutting area W occurs is possible according to the result of the input operation by the designer (step S27). When it is determined as YES and it is confirmed that the design change is possible, the design data of the mold holder 20 that has been corrected is read after waiting for the designer to perform the design data correction work thereafter. Processing is executed (step S29). Then, with respect to the mold holder 20 whose design has been changed in this way, the processing after step S5 in FIG. 4, that is, polyhedral model information and error-containing model information are generated, and the uncut region W is calculated based on the generated information. The process is executed by the same procedure as described above.

  On the other hand, when it is determined NO in step S27 and it is confirmed that the shape of the mold holder 20 cannot be changed, the calculation means 4 moves to the next step S31 and the type of the end mill 10 can be changed. The process which determines whether it is is performed is performed. That is, in this step S31, it is determined whether there are other end mills 10 that can be used in light of various shape data of the end mills 10 stored in the storage means 3.

  If it is determined YES in step S31 and it is confirmed that there are other usable end mills 10, the verification target is changed to the end mill 10 (step S33). The processing after step S11 in FIG. 4 for calculating the uncut region W based on the shape data is repeated in the same manner. When there are a plurality of types of end mills 10 that can be used, the verification target is changed in descending order of priority.

  On the other hand, when it is determined NO in step S31 and it is confirmed that the type of the end mill 10 cannot be changed, the calculation means 4 displays some error message indicating that the mold holder 20 cannot be processed. The process displayed on the means 5 is executed (step S35).

  In the flowcharts shown in FIGS. 4 to 8, the procedure for calculating the uncut region W of the seating surface processing portion 22 cut by the tip portion 12 a of the end mill 10 has been described. However, the outer peripheral portion 12 b of the end mill 10 is described. With respect to the processing of the side processed portion 24, the hole, and the like that are cut by the above, for example, it is possible to verify whether or not the processing is possible by checking the interference of the end mill 10 by performing a normal processing simulation. Specifically, a path followed by the end mill 10 when machining the side surface machining unit 24 or the like is set as a tool movement path, and interference between the end mill 10 moving along the tool movement path and the error-containing model information 20A is detected. By checking, whether or not the side surface processing portion 24 can be processed is verified.

  As described above, in the above embodiment, the above-described mold is based on the three-dimensional design data of the mold holder 20 and the shape data of the end mill 10 that processes the mold holder 20 while rotating around the central axis. When verifying the machining of the mold holder 20, the model information of the mold holder 20 (in the present embodiment, the error-containing model information 20A) generated based on the three-dimensional design data is transferred to a predetermined movement path. A step (S11) of performing a machining simulation for moving the end mill 10 along the path and calculating an uncut region W that cannot be machined by the end mill 10 due to interference between the end mill 10 and a part of the mold holder 20 (S11); When the uncut region W is calculated in this step, the uncut region W is flattened by the radius r of the end mill 10. Step (S63) in which at least a part thereof is calculated as a tool placement range T, and the tool placement range T is divided into a grid and processed by the end mill 10 with the center placed at each grid point. A step of calculating, for each lattice point, a machining removal amount J of the uncut region W and an interference amount K between the end mill 10 and an object to be interfered (for example, the protrusion 44 shown in FIGS. 22 to 30). In S67), among the lattice points, an optimum lattice point op having a large machining removal amount J and a small interference amount K is obtained (S69), and the center of the end mill 10 is arranged at the optimum lattice point op. Necessary for removing the uncut region W because the step (S73) of calculating the cut region Y generated in the interfered object is performed based on the obtained tool placement model information. There is an advantage that the designer to allow the design change of the die holder 20 more properly be effectively assisted.

  That is, in the above embodiment, when the uncut region W is calculated as a result of the machining simulation of the mold holder 20, the arrangement range T of the end mill 10 for processing the uncut region W is calculated, and this Among the lattice points obtained by dividing the tool arrangement range T into a lattice shape, an optimum lattice point op having a large machining removal amount J in the uncut region W and a small interference amount K to the interfered object is obtained. For this reason, the unmilled region W can be efficiently processed and removed by the end mill 10 whose center is arranged at the optimum lattice point op, and the scraped region Y generated in the interfered object can be suppressed to the smallest possible range. Then, the designer who knows the existence of the cutting area Y calculated in this way shifts the position of the interfered object (protrusion 44) by the amount of the cutting area Y to minimize the design. Since the generation of the cut region Y can be eliminated by the change, the necessary design change can be easily and appropriately performed.

  In addition, according to the above configuration, the designer can perform the above examination work before creating NC machining data (data such as the type of tool to be used and machining path) of the mold holder 20. The mold holder 20 can be designed efficiently while taking into consideration various problems related to machining such as the uncut region W and the cut region Y.

  In particular, in the above-described embodiment, a portion (for example, shown in FIG. 26) in which the design change cannot be performed from a region (maximum tool placement range Ta) in which the uncut region W is planarly expanded by the radius r of the end mill 10. Since a range excluding a region where the end mill 10 interferes with the side machining portion 24 or the like) is set as the tool arrangement range T, a portion where the design cannot be changed interferes with the end mill 10. Therefore, there is an advantage that the die holder 20 can be more appropriately processed by the end mill 10.

  Further, as shown in the above-described embodiment, the product to be verified is a mold holder 20 for holding a press-molding mold part, and the product to be processed (machined portion) by the end mill 10 is used. In the case where the seat surface processing portion 22 serving as a mounting seat for holding the press-molding die part is included, the seat surface processing that requires particularly flatness in order to firmly hold the die part. Since it is possible to effectively prevent the uncut region W from being generated in the portion 22, there is an advantage that the mold part can be appropriately held by using the mounting seat formed of the smooth seat surface processing portion 22.

  Moreover, in the said embodiment, since the cutting area | region Y is comprised so that it may be displayed on the display means 5 in the state colored with the color different from the design data of the said mold holder 20, a designer is There is an advantage that the existence of the cut region Y can be easily identified, and a design change necessary for eliminating the cut region Y can be easily considered.

  In the embodiment described above, when the unmilled region W generated in the seating surface processing portion 22 of the mold holder 20 is processed and removed by the end mill 10, the cutting region Y generated in the interfered object such as the protrusion 44 is calculated. The configuration of the present invention has been described by taking as an example, for example, the side processed portion 24 is processed by the tip portion 12a of the end mill 10 whose center axis (Z axis) is horizontal, and an uncut region is left there. In the case where W is generated, the configuration of the present invention can also be applied when calculating the cutting area Y generated when the uncut area W of the side surface processing portion 24 is processed and removed.

It is a block diagram which shows schematic structure of the machining verification assistance apparatus concerning one Embodiment of this invention. It is a figure which shows the shape of an end mill. It is a figure which shows the state which displayed a part of metal mold | die holder on the display means three-dimensionally. It is a flowchart which shows the content of the first half part of the arithmetic processing performed in the said machining verification assistance apparatus. It is a flowchart which shows the content of the latter half part of the said arithmetic processing. 5 is a subroutine showing specific contents of an error-containing model information generation process executed in the flowchart of FIG. FIG. 5 is a subroutine showing specific contents of an uncut area calculation process executed in the flowchart of FIG. 4. FIG. It is a subroutine which shows the specific content of the cutting area calculation process performed with the flowchart of FIG. It is a figure which shows the metal mold | die holder (polyhedral model information) by which the polyhedral process was carried out locally. It is a figure which shows the condition when extending the casting part of polyhedron model information by a casting error. It is a figure which shows the specific content of the expansion process of the said casting part. FIG. 12 is a diagram for supplementarily explaining the contents of the extension process shown in FIG. 11. It is a figure which shows the condition when extending the machining part of polyhedron model information by a casting error. It is a figure for demonstrating the procedure which synthesize | combines the casting part and machining part after an expansion process. It is a figure for demonstrating the procedure which synthesize | combines the machining parts after an expansion process. It is sectional drawing of the error content model information used as the object of the said unshaving area | region calculation process. It is a figure for demonstrating the procedure which calculates | requires the sweep shape of the reverse shape of an end mill. It is a figure for demonstrating the procedure which produces | generates the tool movement path | route surface of a Z map model format. It is a reference figure for explaining supplementarily the procedure which generates the above-mentioned tool movement course surface. It is a figure for demonstrating the procedure which calculates the uncut region. It is a figure which shows the state which displayed the said uncut part area | region on the display means with the design data of the metal mold | die holder. It is a figure which shows the state which displayed the other part of the metal mold | die holder on the display means. It is sectional drawing of the error content model information corresponding to the part of FIG. It is a figure which shows the state which displayed the calculated uncut area | region on the display means with the design data of the said mold holder. It is a figure for demonstrating the procedure which calculates the maximum tool arrangement | positioning range corresponding to the uncut material area | region of FIG. It is a figure for demonstrating the procedure which extracts a tool arrangement | positioning range from the said maximum tool arrangement | positioning range. It is a figure which shows the state which divided | segmented the said tool arrangement | positioning range into the grid | lattice form, and has arrange | positioned the center of an end mill at each grid point. It is a figure for demonstrating the procedure which specifies the optimal lattice point for processing one point on the outline of the said uncut material area | region among the said tool arrangement | positioning ranges. It is a figure which shows the state which has arrange | positioned the center of an end mill in the said optimal lattice point. It is a figure which shows the state which displayed the calculated cutting area on the display means with the design data of the said mold holder.

Explanation of symbols

1 machining verification support device 3 storage means (storage medium)
4 Calculation means 5 Display means 10 End mill (tool)
20 Mold holder 20A Error-containing model information (product model information)
22 Bearing surface processing part 44 Protrusion part (interfering object)
J Machining removal amount K Interference amount T Tool placement range W Uncut area Y Cutting area op Optimal grid point r (Tool) radius

Claims (7)

A method for supporting verification of machining of the product based on three-dimensional design data of the product and shape data of a tool that processes the product while rotating around a central axis.
A machining simulation for moving the tool along a predetermined movement path is performed on the model information of the product generated based on the three-dimensional design data, and the product information is generated due to interference between the tool and a part of the product. Calculating an uncut area that cannot be machined with a tool;
When the uncut region is calculated in this step, the uncut region is expanded in a plane by the amount of the radius of the tool, and at least a part thereof is calculated as a tool placement range;
The tool placement range is divided into grids, and the machining removal amount of the uncut region processed by the tool whose center is arranged at each grid point, and the interference amount between the tool and the interfered object are assigned to each grid. Calculating for each point;
Among the lattice points, an optimum lattice point having a large machining removal amount and a small interference amount is obtained, and the interfered object is obtained based on tool placement model information obtained by placing a tool center at the optimum lattice point. A machining verification support method, comprising: calculating a cutting area generated in the machining. The machining verification support method according to claim 1,
The tool placement range is set to a range obtained by excluding a region where the interference of the tool with a part where design change is impossible occurs from a region where the uncut region is expanded in a plane by the radius of the tool. A machining verification support method characterized by the above. The machining verification support method according to claim 1 or 2,
The product is a mold holder for holding a press-molding mold part, and the object to be processed by the tool includes a seating surface processing portion that serves as a mounting seat for the press-molding mold part. A machining verification support method as a feature. Machining verification that causes a computer to perform computations related to product machining based on the three-dimensional design data of the product and the shape data of a tool that processes the product while rotating around the central axis A support program,
A machining simulation for moving the tool along a predetermined movement path is performed on the model information of the product generated based on the three-dimensional design data, and the product information is generated due to interference between the tool and a part of the product. Calculating an uncut area that cannot be machined with a tool;
When the uncut region is calculated in this step, the uncut region is expanded in a plane by the amount of the radius of the tool, and at least a part thereof is calculated as a tool placement range;
The tool placement range is divided into grids, and the machining removal amount of the uncut region processed by the tool whose center is arranged at each grid point, and the interference amount between the tool and the interfered object are assigned to each grid. Calculating for each point;
Among the lattice points, an optimum lattice point having a large machining removal amount and a small interference amount is obtained, and the interfered object is obtained based on tool placement model information obtained by placing a tool center at the optimum lattice point. A machining verification support program comprising: a step of calculating a cutting area generated in the machining.   A storage medium storing the machining verification support program according to claim 4. A storage medium according to claim 5;
A computing means for performing computation according to the machining verification support program stored in the storage medium;
A machining verification support apparatus, comprising: a display unit configured to display an image of the cutting area calculated by the calculation unit. In the machining verification support device according to claim 6,
The machining verification support apparatus according to claim 1, wherein the display means displays the cut area in a color different from the design data of the product.

Images