JPH0981219A - Cam system for preparing route of die machining tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To constitute a CAS system capable of automatically smoothing the tool route of a part adjacent to a suddenly changed part in a cross-sectional shape even when the suddenly changed part is included in the die shape. SOLUTION: The CAS system is provided with a shape discontinuous line preparing means for retrieving the tool center positions of a specified tool T simultaneously having plural contacts in the case of executing along-shape machining by the specified tool T based upon respective recessed part data DD1 to DD4 in a prescribed machining area in a die form F and preparing shape discontinuous lines NL1 to NL4 by connecting those tool center positions, an intermediate cross section preparing means for preparing plural intermediate cross sections of the shape in the machining area so that any one of intermediate cross sections passes positions corresponding to both the end points EP of the shape discontinuous lines NL1 to NL4 and a tool route preparing means for preparing a tool route for executing along-shape working for the shape in the machining area by the specified tool T based upon the plural intermediate cross sections and outputting the prepared tool route as NC data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a CAM system for creating a tool path for performing a machining along a shape of a mold shape with a designated tool from a mold shape model composed of a free-form surface (including a plane). In particular, the present invention relates to a CAM system capable of automatically smoothing a tool path of a portion adjacent to a sectional shape sudden change portion in a die shape.

[0002]

2. Description of the Related Art When a die shape is machined by an NC (numerical control) machine tool, the die material to be machined generally has high hardness. Therefore, the tool should be placed along the curved surface of the die shape model. By adopting shape-based machining that moves and cuts along the die shape, it is often attempted to stabilize the cutting load and prevent the occurrence of machining errors due to rapid changes in tool operation.

As a CAM system for creating a tool path for performing such a machining along a shape with a designated tool, the one previously disclosed by the applicant of the present application in Japanese Patent Laid-Open No. 7-148644 is known. In the system, the concave part that is left uncut when machining with a large diameter tool is extracted, and the tool path for machining the concave part along the shape with a tool with a smaller diameter is set so that the tool follows the curved surface of the mold shape model. It is created as something to move. And when creating the tool path, at a predetermined interval in the tool movement direction, take a number of intermediate cross sections for the recesses, and provide dividing points on these intermediate cross sections to divide them into a predetermined number, A point sequence is configured by connecting the tool center positions corresponding to the respective dividing points in the tool movement direction in the intermediate cross sections, and the point sequences are connected at the ends to form a tool path.

[0004]

By the way, in a mold shape defined by a compound curved surface formed by combining a plurality of curved surfaces, there is a curved surface whose cross-sectional shape changes abruptly, such as a shape feature. There is. However, in the above-mentioned conventional CAM system, it is not possible to automatically search for the existence of such a sudden change in cross sectional shape and deal with it, and therefore, the intermediate cross section is placed at a position away from both ends of the sudden change in cross sectional shape in the tool moving direction. In some cases, the tool path may be created based on the intermediate cross-section that has been set.In such a case, the tool path that should have been smooth before and after the sudden change in cross-sectional shape should also be affected by the shape change of the sudden change in cross-sectional shape. There was the inconvenience that the tool path changed when receiving it.

For this reason, conventionally, when a user of the CAM system performs a cutting study work or a measurement work, a user visually inspects whether or not a cross-sectional shape sudden change portion exists in the die shape, and, for example, FIG. As shown in the plan view of (a) and the perspective view of (b) of FIG.
If CF exists, position the intermediate section CS so that any intermediate section CS passes through the position on the recess corresponding to the tool center position for machining both ends in the tool movement direction of the sudden change in section shape CF. In addition to designating to the system, a distance between those positions is divided by an integer and an intermediate cross-section creation pitch P that is equal to or less than a predetermined value is specified, and based on the specified position of intermediate cross section CS and creation pitch P, the CAM system As shown in FIG. 10, the intermediate section CS of the mold shape F at each intermediate section position is obtained, and the intermediate section CS and the designated pick feed amount PF
For the designated tool T, the number of tool paths is determined from and the tool center positions corresponding to the equal division points for the number of tool paths on each intermediate section CS are connected in the tool movement direction as shown in FIG. The tool path CL of
Therefore, conventionally, the man-hours of the user have been increased and the skill of the user has been required for designating the installation position of the intermediate section CS.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a CAM system that advantageously solves the above-mentioned problems, and a mold machining tool path forming C of the present invention is provided.
As shown in the concept in FIG. 1, the AM system has a tool center position where a specified tool simultaneously has a plurality of contact points when processing along a shape with a specified tool for each recess data in a predetermined processing area in a die shape. And a shape discontinuity line creating means 1 for connecting the tool center positions to create a shape discontinuity line
And a plurality of intermediate cross-sections of the shape in the processing region are formed so that any one of the intermediate cross-sections passes through the positions of the shape in the processing region corresponding to both end points of the shape discontinuity line. An intermediate cross section creating means 2 and a tool path creating means 3 for creating a tool path for machining the shape in the working area along the shape with the specified tool based on the plurality of intermediate cross sections and outputting the tool path as NC data. And,

In such a CAM system, the shape discontinuity line creating means 1 makes a plurality of contact points of the designated tool when machining along the shape with the designated tool for each concave data in the predetermined machining area in the die shape. Are searched for at the same time, a shape discontinuity line is created by connecting those tool center positions, and the intermediate cross-section creating means 2 also determines the end points of the shape discontinuity line of the shape in the machining region. A plurality of intermediate cross sections for the shape in the machining region is made such that any one of the intermediate cross sections passes through the position corresponding to each of the positions. A tool path for machining the shape in the machining area with the specified tool along the shape is created, and this is output as NC data.

Therefore, according to the CAM system of the present invention, the positions of the plurality of intermediate cross sections are set so that any one of the intermediate cross sections passes through the position on the recess corresponding to the center position of the tool for machining both ends of the sudden change in cross section. The tool path, which is automatically set and automatically created based on the intermediate cross section, for machining along the shape with the specified tool is output as NC data. However, in order to specify the installation position of the intermediate cross section to secure the smoothness of the tool path that should be smooth before and after the sudden change in the cross-sectional shape, the user's man-hours increase and the user's skill is required. And therefore can reduce the man-hours of the user who uses the CAM system,
It is possible to always bring high processing quality to the mold processing in the CAM system.

In the present invention, the shape discontinuity line creating means 1 leaves a portion of the shape discontinuity lines that overlap each other by an amount corresponding to any one of the shape discontinuity lines. It is more preferable to remove it by removing.

That is, according to the above, for example, in the case where the cross-sectional shape suddenly changes in the middle of a continuous curved surface and the shape discontinuity lines of a plurality of recesses adjacent to each other partially overlap each other. By removing the overlapping part by leaving only one shape discontinuity line, the end points of the shape discontinuity line can be set at both ends of the overlapping part, and the positions corresponding to those end points can be set. Since the intermediate cross section can be provided, even in such a case, it is possible to secure the smoothness of the tool path that should have been originally smooth before and after the sudden change in cross section.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG.
FIG. 1 is a configuration diagram functionally showing the configuration of a CAM system as an example of a CAM system for making a die machining tool path according to the present invention, and a CAM of this example shown by reference numeral 11 in the figure.
The system modifies a part of the operation program of a normal CAM system, and automatically searches for a sudden change in cross-sectional shape in the recess in the specified machining area, and a tool for machining along the shape corresponding to the sudden change in cross-sectional shape. The function according to the present invention for automatically creating a path is added.

In order to provide such a function, the CAM system 11 of this embodiment, as shown in FIG. 2, includes a shape discontinuity line automatic creation unit 12 as the shape discontinuity line creation means 1,
Automatic intermediate section creating unit 13 as the intermediate section creating means 2
And a tool path generation unit 14 as the tool path creation means 3
And, where the shape discontinuity line automatic creation unit 12
3A, as shown in FIG. 3A, are two curves U1, which control the machining direction, as the curves that partition the machining region C described above.
U2 and two curves V1 and V2 that control the pick feed direction
In addition to inputting, the solid model that defines the above-mentioned mold shape F, tool information such as the tool diameter of the specified tool T and the effective tool length, and the machining conditions such as the pick feed amount PF and the maximum value of the intermediate section creation interval. By inputting, for each recess data in the processing area C in the mold shape F, the designated tool T
At the time of machining along the shape, the tool center position where the specified tool has a plurality of contact points at the same time is searched, and the shape discontinuity line is created by connecting the tool center positions.

Then, the automatic intermediate section creating unit 13 processes the processing area C so that any intermediate section passes through the position of the shape in the processing area C corresponding to each end point of the shape discontinuity line. Create multiple intermediate cross sections for the shape in
Based on the plurality of intermediate cross sections, the tool path generation unit 14 uses a tool path CL for processing the shape in the processing region C along the shape with the designated tool T, as shown in FIG. 3B.
Is created and is output as NC data.

Specifically, the CAM system of this embodiment
11 executes the processing program shown in FIG. 4 as the shape discontinuity line automatic creation unit 12, and in this program, first, in step 21, concave data in the designated area C is created. The applicant of the present invention first created the recess data in JP-A-7-1486.
Similar to the CAM system disclosed in Japanese Patent Laid-Open No. 44-44, a concave portion and a corner portion having a corner portion in which a cross section area left uncut from a designated machining area by a tool having a diameter larger than the designated tool becomes a predetermined amount or more This is performed by extracting a concave portion having no cross section. According to this method, when the cross-sectional shape sudden change portion CF exists in the processing region C of the die shape F as shown in FIG. Depending on the tool diameter of the diameter tool, for example, as shown in FIG. 2B, the concave portion DD1 along the ridgeline between the left slope and the bottom surface of the cross-sectional shape sudden change portion CF, the cross-sectional shape sudden change portion CF and the bottom surface The concave portion DD2 along the ridge line between them, the concave portion DD3 along the ridge line between the sudden change section CF and the slope, and the concave portion DD4 along the ridge line between the left side slope and the bottom face of the sudden change cross section CF. The data of each recess is created in the form of a dot sequence.

Next, here, in step 22, FIG.
As shown in FIG. 5, with the range of each recess data set as a boundary, the specified tool T simultaneously makes a plurality of contact points with respect to the mold shape F at each constituent point of the point sequence of the recess data as shown in FIG. 5D. The tool center position having CP is searched from the mold shape solid model. In addition, in FIG. 5C and FIG.
A tool center position TC1 of the designated tool T having two contact points CP at the same time for DD2 and a position tool center position TC2 of the designated tool T having two contact points CP at the same time for the recess DD3 are shown.

In this way, when the designated tool T retrieves the tool center position having a plurality of contact points CP with respect to the die shape F at the same time for each constituent point of the point sequence of the recess data, here, in the next step 23, these are calculated. Create a shape discontinuity line by connecting the tool center position to the corresponding point sequence component points in the order of each depression data point sequence, and write the shape discontinuity line of each depression data in the shape discontinuity line table and output. To do. For example, with respect to the recesses DD1 to DD4 in FIG. 5D, as shown in FIG. 5E, shape discontinuity lines NL1 to NL4 each having both end points EP are respectively created (shape discontinuities continuous with each other). The end points of the line on the continuous side are coincident).

Next, the CAM system 11 of this embodiment is
The processing program shown in FIG. 6 is executed as the intermediate section automatic creation unit 13, and in this program, first, step 31
Then, by extracting the combination of the two shape discontinuity lines from the plurality of shape discontinuity lines created earlier, search the overlapping part between these shape discontinuity lines, in the next step 32, If there is no overlapping portion, and if there is no overlapping portion, the process returns to step 31 and the combination of the next two shape discontinuity lines is extracted. Then, the process proceeds to the next step 33 to register the number of the shape discontinuity line having the overlapping part and the start point and the end point of the overlapping part in the overlapping part table.

Then, in the following step 34, it is judged whether or not the search has been completed for all the combinations of the shape discontinuity lines. If the search has not been completed for all the combinations, the process proceeds from there to step 31. If you go back and extract the combination of the next two shape discontinuity lines, and the search for all the combinations is completed, the step
Proceeding from 34 to the next step 35, the overlapping portion is removed. In the removal of the overlapping portion, a portion where two or more shape discontinuity lines overlap each other is removed while leaving only one shape discontinuity line.

For example, as shown in FIG. 7 (a), in the case where the cross-sectional shape is further abruptly changed at the central portion in the middle of continuous cross-sectional shape abruptly changed portion CF, the cross-sectional shape abruptly changed portion CF is obtained.
Even if two recesses DD adjacent to each other that partition the above are not connected to each other at their central portions, the central portions of the recesses DD are close to each other as shown in FIG. There is a case where the above-mentioned partial overlap between the shape discontinuity lines NL with respect to each other occurs, and even in such a case,
As described above, if any one of the shape discontinuity lines is left as the overlapping portion and is removed, the end points EP of the shape discontinuity line are generated on both sides of the removed portion. Even for both ends of the central portion where the angle is suddenly changed, an intermediate cross section can be set as described later.

Next, at step 36, two curves U1 and U2 for controlling the machining direction, which is a reference curve with respect to the end point, from the position of each end point of each shape discontinuity line.
The closest point on one of the points (for example, the curve U1) is calculated, and in the following step 37, the above-mentioned end points and the closest point on the curve corresponding to the reference point are calculated on the plan view as shown in FIG. Extend the connecting line to the other reference curve (curve U1
, A corresponding point is created at a position where the curve U2) and the straight line intersect each other, and at least a position passing through each end point, the closest point to the curve U1 to the end point, and the corresponding point on the curve U2 is at least There, it is decided as the position to set the intermediate section.

In the following step 38, the distance between the intermediate cross-section setting positions on each of the curves U1 and U2 is calculated, and the distance is divided by an integer to make the intermediate cross-section creation pitch P equal to or less than the predetermined section distance. And in the final step 39,
A plurality of intermediate cross-sections CS are created for the mold shape F in the processing area C by opening the obtained intermediate cross-section creation pitch P as in the case of FIG. The plurality of intermediate cross sections CS thus created are such that at least one of the intermediate cross sections CS passes through at least each end point of each shape discontinuity line on the plan view.

Then, the CAM system 11 of this embodiment is used.
Executes the processing program shown in FIG. 8 as the tool path generation unit 14, and in this program, first in step 41,
The maximum cross-section length of the cross-section lengths of the plurality of intermediate cross-sections CS is calculated, and then, in step 42, a tool having a pick-feed amount equal to or less than the specified pick-feed amount from the maximum cross-section length and the specified pick-feed amount. The number of paths is calculated, and in the next step 43, each intermediate section is equally divided by the number of tool paths, and equidistant points for the number of tool paths are provided on each intermediate section. Similarly to the above, the tool center position corresponding to each equal division point on each intermediate section, that is, the designated tool T when machining the equal division point with the designated tool T
The tool center position of is connected in the tool movement direction between the intermediate cross sections to form a point sequence, and the point sequences are connected at the ends to create the tool path CL described above and to specify it with the tool path CL. Check the interference between the mold shape solid model and the designated tool T when the tool T is moved, and if the interference occurs, partially change the tool path CL by a known method to remove the interference. In the final step 45, the tool path CL thus created is converted into NC data by a known method, and the NC data is output.

Thus, according to the CAM system of this embodiment, the positions of a plurality of intermediate cross sections are set so that any one of the intermediate cross sections passes through the position on the recess corresponding to the tool center position for machining both ends of the sudden change in cross sectional shape. The tool path, which is automatically set and automatically created based on the intermediate cross section, for machining along the shape with the specified tool is output as NC data. However, in order to specify the installation position of the intermediate cross section to secure the smoothness of the tool path that should be smooth before and after the sudden change in the cross-sectional shape, the user's man-hours increase and the user's skill is required. Therefore, it is possible to reduce the number of man-hours of the user who uses the CAM system and to always provide a high machining quality to the die machining in the CAM system. .

Further, according to the CAM system of this embodiment, for example, the cross-sectional shape suddenly changes in the middle of a continuous curved surface, and the shape discontinuity lines of a plurality of adjacent recesses partially overlap each other. In such a case, by removing the overlapping part by leaving only one of the shape discontinuity lines, it is possible to set the end points of the shape discontinuity line at both ends of the overlapping part, and Since the intermediate cross section can be provided at the corresponding position as well, even in such a case, it is possible to ensure the smoothness of the tool path that should be originally smooth before and after the sudden change in cross section.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing a basic configuration of a CAM system for creating a die machining tool path according to the present invention.

FIG. 2 is a configuration diagram functionally showing the configuration of an embodiment of a CAM system for making a die machining tool path according to the present invention.

FIG. 3 is an explanatory diagram showing input / output data of the CAM system of the above embodiment.

FIG. 4 is a flowchart showing a processing program as a shape discontinuous line automatic generation unit of the CAM system of the above embodiment.

FIG. 5 is an explanatory diagram showing a process as a shape discontinuous line automatic generation unit of the CAM system of the above embodiment.

FIG. 6 is a flowchart showing a processing program as an intermediate section automatic creation unit of the CAM system of the above embodiment.

FIG. 7 is an explanatory diagram showing a process as an intermediate section automatic creation unit of the CAM system of the above embodiment.

FIG. 8 is a flowchart showing a processing program as a tool path generation unit of the CAM system of the above embodiment.

FIG. 9 is an explanatory diagram showing a conventional method of setting an intermediate cross-section position.

FIG. 10 is an explanatory diagram showing a conventional setting state of a plurality of intermediate sections based on the setting position in the conventional method.

FIG. 11 is an explanatory diagram showing a conventional tool path creation state based on setting of a plurality of intermediate sections in the conventional method.

[Explanation of symbols]

 1 Shape discontinuity line creation means 2 Intermediate cross section creation means 3 Tool path creation means 11 CAM system 12 Shape discontinuity line automatic creation section 13 Intermediate cross section creation section 14 Tool path creation section C Machining area F Mold shape T Designated tool CF Sectional shape sudden change CL Tool path CS Intermediate section

Claims (2)

[Claims] 1. For each recess data in a predetermined machining area in a die shape, a tool center position at which the designated tool has a plurality of contact points at the time of machining along the shape with the designated tool is searched, and those tool center positions are searched. And a shape discontinuity line creating means (1) for connecting the shape discontinuity line and a position corresponding to each of both end points of the shape discontinuity line of the shape in the processing area. To pass
Intermediate cross-section creating means (2) for creating a plurality of intermediate cross-sections for the shape in the machining area, and a tool for machining the shape in the machining area along the shape with the designated tool based on the plurality of intermediate cross-sections. A CAM system for creating a tool machining tool path, which comprises a tool path creating means (3) which creates a path and outputs it as NC data. 2. The shape discontinuity line creating means (1) defines a portion where a plurality of shape discontinuity lines overlap each other,
The CAM system for making a tool machining tool path according to claim 1, wherein any one of the shape discontinuity lines is left and removed.