JPH06348324A - Method for generating basic data for nc data - Google Patents

Abstract

PURPOSE:To generate the NC data for efficient machining by imposing restrictions on a normal vector at a tool path point, determining the attitude of a tool, within certain limits and generating the basic data for the NC data. CONSTITUTION:Two mutually different reference planes are selected and inclination permissible ranges of the normal vector by the planes are numerically or graphically inputted and stored in a RAM 2. Then when first intermediate basic data read out of the RAM 2 have its normal vector within the inclination permissible range, the coordinate values of the tool path point of the intermediate basic data and the value of its normal vector are stored as basic data in a basic data storage area. If the normal vector of the intermediate basic data deviates from the inclination permissible range on the Z-X plane or Y-Z plane, the value in the inclination permissible range which is the closest to the inclination of the normal vector is stored as its normal vector in the basic data storage area together with the tool path point of the intermediate basic data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of creating basic data for NC data.

[0002]

2. Description of the Related Art A tool path point and a normal vector of a machining shape at the tool path point are sequentially extracted from shape data created by a CAD system and directly used as basic data for creating NC data. A method of creating the basic data is known. Creation of NC data is performed based on this basic data, and each tool is positioned such that the tip of the tool is located on the tool path point in a state where the tool posture matches the normal vector at each tool path point. The linear movement position and rotation position of each axis for each path point are determined,
NC data is automatically created.

However, if the normal vector of the machining shape at the tool path point is used as it is as the orientation of the tool, the chuck or head mounted with the tool may interfere with the work depending on the machining shape. For example, when the tip of the tool moves along the machining surfaces L1 and L2 as shown in FIG. 5, when the tip of the tool moves from the machining surface L1 to L2 and the tool axis becomes substantially horizontal, the chuck or There is a case where the head or the like interferes with the work, and the normal machining operation is hindered, resulting in poor machining efficiency.

Further, even in the case of processing a curved surface shape with few undulations in which the inclination of the tool does not matter, the normal vector of the shape is redefined as the tool attitude for each tool path point, N for determining the rotational position of each axis
The amount of C data increases unnecessarily, which may hinder the storage and processing of NC data.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method of creating basic data for NC data which solves the drawbacks of the prior art and is capable of creating NC data for efficient processing. It is in.

[0006]

The present invention has achieved the above object by creating a basic data for NC data by setting a certain limit on the normal vector of the tool path point that determines the attitude of the tool.

That is, the tool path point and the normal vector of the machining shape at the tool path point are sequentially extracted from the shape data created by the CAD system, and the tilt allowable range in which the tilt of the normal vector at the tool path point is determined. If it is within the range, the normal vector is set as the normal vector at the tool path point, and if it is out of the tilt allowable range, a value within the tilt allowable range closest to the tilt of the normal vector is set at the tool path point. By creating the basic data as the normal vector, it is possible to create NC data that prevents interference between the chuck of the tool, the head, and the like and the work and performs efficient machining.

Further, the tool path point and the normal vector of the machining shape at the tool path point are sequentially extracted from the shape data created by the CAD system, and the normal vector at the tool path point extracted this time and the previous tool path are extracted. If the angle formed by the point's normal vector is within the determined minimum movement angle, the previous normal vector is set as the normal vector at the tool path point extracted this time, and the normal at the tool path point extracted this time. If the angle formed by the vector and the previous normal vector exceeds the minimum movement angle, by creating the basic data by using the normal vector at the tool path point extracted this time as the normal vector at the tool path point, To reduce the number of control data for determining the rotational position of each axis and shorten the basic data so that NC data for efficient machining can be created. It was.

[0009]

[Operation] The slope of the normal vector forming the basic data is
By constraining the work within the predetermined allowable tilt range, it is possible to prevent interference between the chuck equipped with the tool or the head and the work, and perform efficient machining.

When the angle formed by the normal vector at the newly extracted tool path point and the normal vector at the previous tool path point is within the determined minimum movement angle, that is, the inclination of the tool does not matter. When a tool path point is extracted from a curved surface shape with few undulations, the previous normal vector is applied as is as the normal vector of the tool path point, so the tool posture changes when the tool moves. There is no useless movement of the rotating shaft, and the processing efficiency is improved. Further, while applying the same normal vector as the normal vector of the tool path point, it is not necessary to set the data defining the normal vector, so that the NC data as a whole is shortened.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a main part of a CAD / CAM system according to an embodiment for carrying out the basic data creating method of the present invention. 1 is a microprocessor (hereinafter referred to as CPU), and 7 is the control of the CAD / CAM system. ROM storing programs, 2 RAM for storing system programs loaded from floppy disk 11 and various data, 3 keyboard, 4 CRT display device (hereinafter referred to as CRT) as a graphic display, 9 tablet An apparatus, 8 is a disk controller, 11 is a floppy disk storing system programs and the like, 10 is an XY plotter for outputting a drawing, 5 is a printer, and these elements are connected via a bus 6. ing.

The tablet device 9 has a screen corresponding area 9a and a menu table 9b. The tablet cursor 9c is moved within the screen corresponding area 9a and the graphic cursor on the CRT 4 is moved to perform an instruction operation.
Various menu items are selected from the system program prepared in the floppy disk 11 by designating an arbitrary position on the display screen 4 and moving the tablet cursor 9c on the menu table 9b to perform an instruction operation. It is like this.

Since a normal design operation using this type of CAD / CAM system, a CAD function for creating shape data, a CAM function for automatically creating NC data, etc. are already known, the description thereof will be omitted.

In the conventional automatic programming device, the coordinate position of the tool path point and the normal vector of the shape surface corresponding to each tool path point are extracted from the shape data and directly used as basic data for creating NC data. However, in the CAD / CAM system of the present embodiment, the basic data created in the same manner as the conventional one is used as the intermediate basic data,
Further, the normal vector of each tool path point stored as the intermediate basic data is regulated according to the processing procedure as shown in FIG. 2 to create the final basic data used for creating the NC data. And
In this respect, the configuration is different from the conventional CAD / CAM system.

Hereinafter, assuming that the intermediate basic data extracted from the shape data has already been read into the RAM 2, the basic data creating method in this embodiment will be described with reference to the flowchart of FIG. The NC program is
Table feed by each linear movement axis of X, Y, Z, a first rotation axis A for swinging the tool in a vertical plane, and a second rotation axis for swinging the tool in a vertical plane orthogonal to the vertical plane. It is created corresponding to the NC machine tool of 5-axis machining consisting of the rotation axis B of.

Therefore, first, in order to regulate the inclination of the normal vector which means the inclination of the tool axis, the operator selects two different planes serving as a reference, and CAD is performed via the keyboard 3 or the tablet device 9. / CAM system, considering the possibility of interference due to the unevenness of the machining shape and the mounting state of the tool, for each plane,
The RAM 2 is stored by inputting a numerical value or a figure as to the tilt allowable range of the normal vector. In this example, since the tool is allowed to swing in each of the vertical planes orthogonal to each other, for example, the inclination of the normal vector is set by two different vertical planes, that is, the Z-X plane and the Y-Z plane. Need to be regulated.
FIG. 3 and FIG. 4 are setting examples in the case where the ZX plane and the YZ plane are selected as the setting criteria of the tilt allowable range, and the tool axis, that is, the tilt of the normal vector, is set to the ZX plane. The projection is counterclockwise from the X axis in the range from Bmin. To Bmax.
Also, the projection onto the YZ plane is regulated counterclockwise from the Y axis within the range from Amin. To Amax. (See FIG. 4).

Then, when the CAM function is activated, the CP
The U1 first reads the first data from the intermediate basic data storage area of the RAM 2 (step S1), and if the intermediate basic data is stored in the storage area (step S1).
2) Whether or not the projection of the normal vector corresponding to the first tool path point read this time to the ZX plane is within the tilt allowable range, that is, counterclockwise rotation from the X axis in the ZX plane. To B
It is determined whether or not it is within the range of min. to Bmax. (step S3). Then, if the projection of the normal vector onto the Z-X plane is within the tilt allowable range, the value of the normal vector of the intermediate basic data is held as it is as a normal vector candidate, while the value of the normal vector of the intermediate basic data is changed. If the projection onto the Z-X plane is out of the tilt allowable range, the normal vector of the intermediate basic data is restricted to newly create a normal vector candidate, and the new normal vector candidate is updated and stored (step S4). ). That is, Z− of the normal vector of the intermediate basic data
If the angle formed by the projection on the X plane with the X axis exceeds the tilt allowable range Bmax., The angle formed by the normal vector with the X axis in the ZX plane is replaced with Bmax. To create a normal vector candidate. Then
If the angle formed by the projection of the normal vector of the intermediate basic data onto the Z-X plane with the X-axis does not satisfy the tilt allowable range Bmin., The angle formed by the normal vector with the X-axis in the Z-X plane is determined. Bmi
Replace with n. to create a normal vector candidate and update and store it.

Then, the CPU 1 determines whether or not the projection of the normal vector candidate onto the YZ plane is within the tilt allowable range, that is, in the YZ plane from Amin. To A counterclockwise from the Y axis.
It is determined whether or not it is within the range of max. (step S5),
Similarly to the above, if the projection of the normal vector candidate on the YZ plane is within the tilt allowable range, the value of the normal vector candidate at the present time is held as it is as the normal vector candidate, while the normal vector candidate at the current time is held. If the projection on the YZ plane is out of the allowable tilt range, the normal vector candidate is restricted to create a new normal vector candidate, and the normal vector candidate is updated and stored (step S6). That is, if the angle formed by the projection of the normal vector candidate on the YZ plane at the present time with the Y axis exceeds the tilt allowable range Amax., The angle formed by the normal vector candidate with the Y axis on the YZ plane. To create a normal vector candidate by replacing Amax.
If the angle formed by the projection of the normal vector candidate on the YZ plane with the Y axis is less than the tilt allowable range Amin., The angle formed by the normal vector candidate with the Y axis on the YZ plane is replaced by Amin. A normal vector candidate is created and updated and stored.

Next, the CPU 1 determines whether or not the intermediate basic data is present before the intermediate basic data currently read (step S7), but the first basic data read from the storage area of the intermediate basic data is determined. At the current stage of processing based on the intermediate basic data, the determination result of step S7 is naturally false. Therefore, the CPU 1 sets the coordinate value of the tool path point of the intermediate basic data currently read and the value of the normal vector candidate at the time of executing step S7 corresponding thereto as the initial basic data in the basic data storage area of the RAM 2. It is stored as a tool path point and a normal vector (step S8), the process proceeds to step S1 again, the next intermediate basic data is read from the intermediate basic data storage area of the RAM 2, and the same process as described above is performed. The process is repeatedly executed and the process proceeds to the determination process of step S7.

When the second and subsequent intermediate basic data are processed, the determination result of step S7 is inevitably true.

Therefore, the CPU 1 stores the normal vector candidate at the present time, that is, the normal vector candidate at the time of executing step S7 corresponding to the newly read intermediate basic data and the basic vector storage area of the RAM 2 immediately before. Find the angle formed by the normal vector of the basic data (step S
9) It is determined whether or not this angle is within the range of the minimum movement angle set and stored in the RAM 2 in advance (step S1).
0). Then, if the angle formed by the normal vector candidate corresponding to the newly read intermediate basic data and the normal vector of the basic data stored immediately before is within the range of the minimum movement angle, the posture of the tool axis is changed. Determined that it is not necessary to
The normal vector of the basic data stored immediately before is set as a normal vector candidate corresponding to the newly read intermediate basic data (step S11), and if this angle exceeds the range of the minimum movement angle, the tool Recognizing that it is necessary to change the posture of the axis, the normal vector candidate at the time of execution of step S10 corresponding to the newly read intermediate basic data is held as it is as a normal vector candidate.

Then, the CPU 1 stores the coordinate value of the tool path point of the intermediate basic data read at the present time and the value of the normal vector candidate at the current time corresponding thereto in the basic data storage area of the RAM 2 as the next basic data. It is stored (step S12), and thereafter, until the determination result of step S2 becomes false and the basic data is created for all the intermediate basic data, the same processing as described above is repeatedly executed to sequentially perform the basic processing. Create data.

Therefore, according to the present embodiment, for the first intermediate basic data read from the RAM 2, as long as the normal vector is within the tilt allowable range, the coordinate values of the tool path point of the intermediate basic data and the method thereof are used. The value of the line vector is stored as it is in the basic data storage area as basic data,
Further, when the normal vector of the intermediate basic data is out of the tilt allowable range on the ZX plane or the YZ plane, the value within the tilt allowable range closest to the tilt of the normal vector is the intermediate basic data. Is stored in the basic data storage area as the normal vector together with the tool path point of.

Further, regarding the second and subsequent intermediate basic data read from the RAM 2, the same regulation as above is applied to the normal vector in the intermediate basic data, and further, the regulated normal vector and If the angle formed with the immediately preceding normal vector stored in the basic data storage area is within the preset minimum movement angle, the value of the immediately previous normal vector stored in the basic data storage area is the intermediate basic data. Is stored in the basic data storage area as its normal vector together with the tool path point, and the angle formed by the regulated normal vector and the immediately preceding normal vector stored in the basic data storage area is set in advance. If it exceeds the range of the minimum movement angle, the value of the regulated normal vector is stored in the basic data storage area as the normal vector together with the tool path point of the intermediate basic data. And thus to be stored in.

That is, what is compared in step S10 is the regulated normal vector of the newly read intermediate basic data and the normal vector at the immediately preceding route point stored in step S8 or step S12. .

It is not always necessary to set the basic data storage area independently of the intermediate basic data storage area.
For example, when it is not necessary to save the intermediate basic data, it is possible to sequentially overwrite and update the basic data obtained by the above-described processing in the corresponding position of the intermediate basic data storage area.

Based on the basic data created in this way, the CPU 1 determines the tip of the tool in a state similar to the conventional method in a state in which the posture of the tool is matched with the normal vector of the tool path point in each basic data. A linear movement position of each axis X, Y, Z and a rotational position of the rotation axes A, B are determined for each tool path point so that the tool is located on the tool path point, and a series of NC data is automatically created. , Which is stored in the floppy disk 11 as a machining program, the NC command relating to the attitude control of the rotation axes A and B is applied to the section of the tool path point to which the same normal vector is applied as the normal vector of the tool path point. There is no need to create it, and the amount of NC data is greatly reduced as a whole.

[0028]

According to the basic data creating method of the present invention,
Since the inclination of the normal vector that constitutes the basic data is constrained within a predetermined inclination allowable range, interference between the chuck equipped with the tool or the head and the work is prevented in advance.
It is possible to perform efficient processing. Also, if the angle formed by the normal vector at the newly extracted tool path point and the normal vector at the previous tool path point is within the determined minimum movement angle, that is, the inclination of the tool does not matter. When extracting a tool path point from a curved surface shape with less undulations, the previous normal vector is applied as is as the normal vector of the tool path point, so the tool posture changes when the tool moves. There is no unnecessary movement on the rotating axis to improve the machining efficiency, and it is not necessary to set the data that defines the normal vector while applying the same normal vector as the normal vector of the tool path point. , The amount of NC data is greatly reduced as a whole.

[Brief description of drawings]

FIG. 1 is a block diagram showing a main part of a CAD / CAM system of an embodiment for carrying out a basic data creating method of the present invention.

FIG. 2 is a flowchart showing an outline of a basic data creating method by the CAD / CAM system of the same embodiment.

FIG. 3 is a conceptual diagram showing an example of setting an allowable tilt range.

FIG. 4 is a conceptual diagram showing an example of setting an allowable tilt range.

FIG. 5 is a schematic view illustrating an inconvenience of the conventional technique.

[Explanation of symbols]

 1 Microprocessor (CPU) 2 RAM 3 Keyboard 4 CRT Display Device 5 Printer 6 Bus 7 ROM 8 Disk Controller 9 Tablet Device 10 Plotter 11 Floppy Disk

Claims (3)

[Claims] 1. A method of creating basic data for creating NC data, wherein a tool path point and a normal vector of a machining shape at the tool path point are sequentially extracted from shape data created by a CAD system, and a tool path is created. If the inclination of the normal vector at the point is within the predetermined inclination allowable range, the normal vector is set as the normal vector at the tool path point, and if it is outside the inclination allowable range, the inclination of the normal vector is set. A method of creating basic data for NC data, wherein basic data is created using a value within the closest allowable tilt range as a normal vector at the tool path point. 2. A method for creating basic data for creating NC data, wherein a tool path point and a normal vector of a machining shape at the tool path point are sequentially extracted from the shape data created by a CAD system, and are extracted this time. If the angle formed by the normal vector of the tool path point and the normal vector of the previous tool path point is within the determined minimum movement angle, the previous normal vector is the normal at the tool path point extracted this time. If the angle formed by the normal vector at the tool path point extracted this time and the previous normal vector exceeds the minimum movement angle, the normal vector at the tool path point extracted this time is set as the line vector. A method of creating basic data for NC data that creates basic data as a normal vector at a point. 3. A method for creating basic data for creating NC data, wherein a tool path point and a normal vector of a machining shape at the tool path point are sequentially extracted from shape data created by a CAD system, and a tool path is created. If the inclination of the normal vector at the point is within the predetermined inclination allowable range, the normal vector is set as the normal vector candidate, while if it is outside the inclination allowable range, it is closest to the inclination of the normal vector. If the value within the allowable tilt range is taken as a normal vector candidate and the angle formed by the normal vector candidate and the previous vector of the tool path point is within the determined minimum movement angle, the previous normal vector is set this time. A normal vector at the extracted tool path point, and if the angle formed by the normal vector candidate and the previous normal vector exceeds the minimum movement angle, the normal vector candidate A method of creating basic data for NC data in which basic data is created as a normal vector at the tool path point.