JPH11175120A - Device and method for generating numerical control data - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically determine the optimum work tool lowering position. SOLUTION: A contour graphic of a work area is taken-out from a graphic keeping file (S21) and, after that, max. permissible distance from the work area to the work tool lowering position is taken-out from original files (S22). Then, the counter graphic of the work area is extended outward by the max. permissible distance so as to obtain an extension area (S23) and, moreover, a work tool lowering prohibiting area is obtained (S24). The work tool lowering prohibiting area is excluded from the extension area so as to obtain an out-of- work area (S25). Then, the out-of-work area is reduced inward by the portion of the radius of a work tool so as to calculate a work tool lowering-enable area (S26). After that, a minimum distance point between the work area and the work tool lowering-enable area is calculated so as to judge whether the minimum distance point can be calculated or not (S28). The calculated minimum distance point is set to the work tool lowering position when the answer is an affirmation (Yes) and the work area is displayed in a display part so as to execute an error processing at the time of a negation (No).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a numerical control data generating apparatus and a numerical control data generating method, and more particularly, to a numerical control (Numerical control; hereinafter referred to as "NC") for cutting with a rotating tool such as a machining center. )
The present invention relates to an NC data creation device for creating NC data used in a machine tool and an NC data creation method.

[0002]

2. Description of the Related Art Conventionally, in an NC data creating apparatus for creating NC data for performing cutting or the like using a rotating tool, when a working tool (rotary tool) is lowered onto a workpiece, the working tool is not used. The descending position is determined by the operator based on experience while taking into consideration the shape of the workpiece, particularly the machining state of the workpiece so as not to collide with an unprocessed portion in the workpiece. In a rotary tool such as an end mill used for shape processing, a cutting edge is provided on a side surface of the rotary tool, and cutting is performed by the cutting edge on the side surface.
That is, unlike a drill having a cutting edge provided on the bottom surface, this type of rotating tool performs cutting with the cutting edge provided on the side surface, unlike a drill having a cutting edge provided on the bottom surface. The position is set outside the workpiece or above the already processed area so as not to collide with the unprocessed portion of the workpiece.

[0003]

However, in the above-mentioned conventional technique, when the movement locus of the processing tool with respect to the contour shape of the processing area is obtained, the operator determines the descent position of the processing tool. It is necessary for the operator of the apparatus to understand the shape of the workpiece and to understand the change in the processing state by the drawing work in advance, and as a result, there is a problem that it takes a lot of time to create the NC program.

[0004] Further, when determining the lowering position of the processing tool,
Conventionally, the lowering position of the processing tool is set on the unprocessed portion of the workpiece, and as a result, the processing tool may be damaged,
Alternatively, the working tool lowering position is set to a position distant from a desired working area, and as a result, a new operation of moving the working tool needs to be performed, resulting in a wasteful operation time and a possibility of reducing work efficiency. There was also.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides an NC data generating apparatus and an NC data generating method capable of automatically determining an optimum position for lowering a tool. With the goal.

[0006]

According to a first aspect of the present invention, there is provided an NC data creating apparatus for creating NC data based on graphic data representing a shape of a workpiece. Machining area extracting means for extracting a machining area to be processed from the graphic data, an extended area setting means for setting an extended area obtained by extending the machining area by a first predetermined area, and prohibiting the tool from descending to the workpiece. Processing tool lowering prohibited area determining means for determining an area, non-processing area setting means for setting a non-processing area in which the processing tool lowering prohibited area is removed from the extended area, and setting the non-processing area to only a second predetermined area Processing tool descendable area setting means for setting a reduced processing tool descendable area; calculating the shortest distance between the processing tool descendable area and the processing area; It is characterized in that it comprises a machining tool lowered position setting means for setting a point-range side to the machining tool lowered position.

According to an eighth aspect of the present invention, in the NC data creating method for creating NC data based on graphic data representing the shape of a workpiece, a processing area to be processed is extracted from the graphic data. Machining area extraction step, an extension area setting step of setting an extension area obtained by extending the machining area by a first predetermined area, and a machining tool lowering prohibited area determination for determining a machining tool lowering prohibited area for the workpiece. Setting a non-machining area in which the machining tool drop prohibition area is removed from the extended area; and setting a machining tool descendable area in which the non-machining area is reduced by a second predetermined area. A tool lowerable area setting step, calculating a shortest distance between the tool lowerable area and the processing area, and calculating a point on the processing tool lowerable area side of the shortest distance. It is characterized in that it contains a processing tool lowered position setting step of setting the tool lowered position.

The other features of the present invention will become apparent from the following description of embodiments of the present invention.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of an NC data generating apparatus according to the present invention. The NC data generating apparatus 1 is a CAD / CAM system via a communication line 2.
(Computer Aided Design / Computer Aided Manufactu
The apparatus is connected to an NC machine tool such as a milling machine for cutting a workpiece using the NC data.

The NC data generating apparatus 1 includes an input unit 3 including a keyboard and a mouse for performing a predetermined input operation, a ROM 4 storing a control tool lowering position setting program, which will be described later, and a ROM 4. A RAM 5 for temporarily storing various calculation results or used as a work area of a CPU, a graphic storage file 6 for storing graphic data created by the CAD / CAM device, and a graphic storage file 6 from a processing area to a processing tool drop position. A display unit including a specification file 7 in which predetermined parameters such as a maximum allowable distance are registered, a keyword registration file 8 in which a character string indicating that the tool can be lowered, and a CRT for displaying a processing area and the like. 9 and a CP that performs various calculations and controls the entire apparatus
U10, and these components and the communication line 2 are connected to each other via a system bus 11.

FIG. 2 is a flowchart showing a method for creating NC data according to the present invention.
It is executed at 10.

In step S1, an attribute is set to allow the tool to be lowered for each area unit, and in step S2, a processing area to be processed is designated from the graphic storage file 6 (hereinafter, this processing area is referred to as "target processing"). Area ").
The processing area is specified by displaying graphic data stored in the graphic storage file 6 on the display unit 9, selecting desired graphic data from the displayed contents, and operating the input unit 3.

Next, in step S3, the diameter of a processing tool such as an end mill to be used is specified, and then, in step S4, processing for setting a processing tool lowering position, which will be described later, is performed. Then, in the following step S5, movement locus data of the processing tool is created with the processing tool descending position set in step S4 as a starting point, and in step S6, an attribute of allowing the processing tool to be lowered is added to the target processing area. In S7, it is determined whether or not there is another processing area to be processed. If the answer is affirmative (Yes), the process returns to step S2, and the above-described processing is repeated. If the answer is negative (No), the process ends.

FIG. 3 is a flowchart of an attribute setting processing routine executed in step S1.

First, in step S11, the keyword registration file 8 is searched, and a character string of "descent" meaning "working tool can be lowered" is read out from the keyword registration file 8, and in the next step S12, the graphic storage file 6 is read. The character text data is extracted from the graphic data stored in the storage device, and it is determined in step S13 whether or not there is character text data. If it is determined that there is character text data, it is determined whether or not the character string (keyword) read in step S11 matches the character text data (step S14). If (No), the process returns to step S12, while if the answer is affirmative (Yes), the process proceeds to step S15, where the attribute of "working tool descendable" is given to the target processing region, and the process returns to step S12.

Then, in the subsequent loop, step S13
If the answer is negative (No), the process proceeds to step S16, and the attribute of “working tool descendable” is sequentially added to the processing area of interest by the interactive operation, and the process ends. That is, the graphic data is displayed on the display unit 9 and the input unit 3 is operated to sequentially designate the processing area to which the attribute is to be added, and the process returns to the main routine (FIG. 2).

FIG. 4 is a plan view of the workpiece to which the attribute of allowing the tool to be lowered has been added by the attribute setting processing routine (FIG. 4).
(A)) and a front view (FIG. 4 (b), where “Descent” is registered in the keyword registration file 8 and the character text data of the processing area A and the processing area B is “Descent”. In this case, the attribute of “working tool can be lowered” is added to the processing area A and the processing area B. In the present embodiment, the area C that is formed to be one end blind in the drawing.
Indicates that this is a target machining area where a hole is drilled using a rotary tool (machining tool). In the drawing, H indicates a predetermined height from the reference plane G. If the processing tool descending position is set at a position higher than the predetermined height H, the unprocessed portion collides with the processing tool and the processing tool is damaged. In this embodiment, the descent position of the processing tool is set so as not to collide with the unprocessed portion.

Next, the processing tool lowering position setting processing (executed in step S4) will be described with reference to the flowchart of FIG.

In step S21, after the contour figure of the processing area of interest is extracted from the figure storage file 6, step S21 is executed.
In step 22, the maximum allowable distance from the target processing area to the processing tool descending position is extracted from the specification file 7, and the subsequent step S
In step 23, the contour figure of the target processing area is subjected to graphic processing such as offset outside by the maximum allowable distance to enlarge the target processing area and obtain an extended area. That is, the extended area D is obtained by enlarging the target processing area C shown in FIG. 6 by the maximum allowable distance as shown in FIG. In the present embodiment, the maximum allowable distance is set to a value obtained by adding a predetermined value to the processing tool diameter specified in step S3.

Next, in step S24, a work tool lowering prohibited area is obtained. That is, the predetermined height H shown in FIG.
By excluding the lower region, that is, the region B, a processing tool lowering prohibition region E as shown in FIG. 8 is obtained.

Next, in step S25, the processing tool lowering prohibition area E (FIG. 8) is excluded from the extended area D (FIG. 7), and a non-processing area F as shown in FIG. 9 is obtained.

Next, in step S26, based on the processing tool diameter specified in step S3, the outside processing area F is subjected to graphic processing such as offset inward by the radius of the processing tool to calculate the processing tool droppable area I. I do. Then, the shortest distance point P between the focused processing area C and the work tool descendable area I is calculated, and it is determined in subsequent step S28 whether the shortest distance point P can be calculated. That is, it is determined whether or not the shortest distance point P can be calculated based on whether or not the shortest distance L (= PQ) between the processing area C of interest and the work tool descendable area I is greater than “0”. When the answer is affirmative (Yes), the point P (the shortest distance point) on the side of the calculated tool shortest distance I on the work tool descendable region I side.
To the tool lowering position.

On the other hand, the answer in step S28 is negative (No).
In the case of, the processing area of interest is displayed on the display unit 9, error processing is performed, and the process returns to the main routine (FIG. 2). That is, in this case, the processing area of interest is displayed on the display unit 9, and the user visually recognizes the processing area of interest displayed on the display unit 9, and
To specify the descent position of the processing tool.

As described above, according to the present embodiment, the optimum descent position of the processing tool can be automatically set. Therefore, by combining this with the processing for calculating the movement locus of the processing tool, the operator's experience can be improved. The creation of NC data can be automated without resorting to it. In addition, it is possible to optimize the movement locus of the processing tool, to prevent the processing tool from being damaged as in the related art, to avoid unnecessary movement of the processing tool, and to improve the working efficiency. it can.

The present invention is not limited to the above-described embodiment. For example, when the above-mentioned area having a height lower than the predetermined height H does not exist in the workpiece, the entire area of the workpiece is prohibited from being lowered. Similarly, the optimal descent position can be determined as a region.

[0027]

As described above in detail, according to the NC data generating apparatus and the NC data generating method of the present invention, the optimum tool lowering position can be automatically set, and therefore, the movement of the processing tool can be performed. In combination with the trajectory calculation processing, the creation of NC data can be automated without relying on the experience of the operator. Further, the movement trajectory of the processing tool can be optimized, and the processing tool can be prevented from being damaged or the useless movement of the processing tool can be avoided as in the related art, and the working efficiency can be improved. .

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of an NC data creating apparatus according to the present invention.

FIG. 2 is a flowchart showing a method for creating NC data according to the present invention.

FIG. 3 is a flowchart of an attribute setting processing routine.

FIG. 4 is graphic data showing a state where an attribute is added to a workpiece.

FIG. 5 is a flowchart of a processing tool lowering position setting processing routine;

FIG. 6 is a diagram showing a state where a processing region of a workpiece is extracted.

FIG. 7 is a diagram showing an extended machining area of a workpiece.

FIG. 8 is a diagram showing a processing tool lowering prohibited area for a workpiece.

FIG. 9 is a diagram illustrating a state in which a processing tool lowering prohibition area is excluded from an extended processing area.

FIG. 10 is a diagram showing a work tool descendable area for a workpiece.

[Explanation of symbols]

3 Input unit (processing tool diameter input means, processing tool descending position specifying means) 10 CPU (processing area extracting means, extended area setting means,
Processing tool lowering prohibited area determining means, non-processing area setting means, processing tool lowering possible area setting means, processing tool lowering position setting means,
Allowable amount calculation means, judgment means)

Claims (14)

[Claims] 1. A numerical control data generating apparatus for generating numerical control data based on graphic data representing a shape of a workpiece, a processing area extracting means for extracting a processing area to be processed from the graphic data, Extended area setting means for setting an extended area obtained by extending the processing area by a first predetermined area;
A tool lowering prohibited area determining means for determining a tool lowering prohibited area for the workpiece, a non-processing area setting means for setting a non-processing area obtained by removing the processing tool lowering prohibited area from the extended area, A tool lowering area setting means for setting a tool lowering area in which the non-machining area is reduced by a second predetermined area, and calculating a minimum distance between the processing tool lowering area and the processing area to calculate the minimum distance A processing tool lowering position setting means for setting a point on the side of the processing tool lowering area to a processing tool lowering position. 2. A processing tool diameter input means for inputting a diameter of a processing tool, and a permissible amount calculating means for calculating a permissible amount by adding a predetermined value to the diameter of the processing tool, wherein the first predetermined area is provided. 2. The numerical control data creating apparatus according to claim 1, wherein the area is an area corresponding to the allowable amount. 3. A processing tool diameter input means for inputting a diameter of a processing tool, wherein the second predetermined region is a region obtained by removing a region corresponding to a radius of the processing tool from the non-processing region. The numerical control data creation device according to claim 1, wherein: 4. The processing tool lowering prohibition area determined by the processing tool lowering prohibition area determining means is the entire surface of the workpiece. Numerical control data creation device. 5. An attribute assignment that has a plurality of processed areas that have already been processed at the time of performing processing in the processing area, and that gives an attribute that allows a tool to be lowered for each of the processed areas from the graphic data. The processing tool lowering prohibited area determined by the processing tool lowering prohibited area determining means excludes the processed area whose surface height from a reference plane is equal to or less than a predetermined value from the entire surface of the workpiece. 4. The numerical control data generation device according to claim 1, wherein the numerical control data generation region is a region defined. 6. The method according to claim 6, wherein the machining area is a hole machining area that is blind at one end, and the predetermined value is a value obtained by subtracting a hole depth of the hole machining area from a surface height from the reference plane. The numerical control data creation device according to claim 5, wherein: 7. A determination unit for determining whether or not the shortest distance can be calculated. When the determination unit determines that the shortest distance cannot be calculated, the processing area is displayed on a display unit. 7. The numerical control data creating apparatus according to claim 1, further comprising a tool lowering position specifying means for displaying a tool lowering position by displaying the numerical control data on the workpiece. 8. A method of generating numerical control data for generating numerical control data based on graphic data representing a shape of a workpiece, a processing area extracting step of extracting a processing area to be processed from the graphic data. An extended area setting step of setting an extended area obtained by extending the processing area by a first predetermined area; a tool lowering prohibited area determining step of determining a tool lowering prohibited area for the workpiece; A non-machining area setting step of setting a non-machining area from which the machining tool lowering prohibited area is removed, and a machining tool descendable area setting of setting a machining tool descendable area obtained by reducing the non-machining area by a second predetermined area Calculating the shortest distance between the work tool droppable area and the processing area, and setting a point on the work tool droppable area side of the shortest distance at the work tool drop position. The method of creating numerical control data, characterized in that and a processing tool lowered position setting step for. 9. A processing tool diameter input step of inputting a diameter of a processing tool, and an allowance calculating step of adding a predetermined value to the diameter of the processing tool to calculate an allowance, wherein the first predetermined 9. The method according to claim 8, wherein the area is an area corresponding to the allowable amount. 10. A processing tool diameter input step of inputting a diameter of a processing tool, wherein the second predetermined region is a region obtained by removing a region corresponding to a radius of the processing tool from the non-processing region. 10. The method for creating numerical control data according to claim 9, wherein: 11. The method according to claim 8, wherein the processing tool lowering prohibited area is the entire surface of the workpiece. 12. An attribute assignment that has a plurality of processed areas already processed at the time of performing processing in the processing area, and provides an attribute of allowing a tool to be lowered for each of the processed areas from the graphic data. The method according to claim 1, wherein the processing tool lowering prohibition area is an area in which the processed area whose surface height from a reference plane is equal to or less than a predetermined value is excluded from the entire surface of the workpiece. The method for creating numerical control data according to any one of claims 8 to 10. 13. The method according to claim 1, wherein the processing area is a hole processing area which is blind at one end, and the predetermined value is a value obtained by subtracting a hole depth of the hole processing area from a surface height from the reference plane. 13. The method for creating numerical control data according to claim 12, wherein: 14. A method for determining whether or not the shortest distance can be calculated, wherein when it is determined that the shortest distance cannot be calculated, the processing area is displayed on a display unit. The method according to any one of claims 8 to 13, further comprising the step of displaying a work tool lowering position on the display.