JPH06102914A - Method for generating machining program for numerical controller - Google Patents

Abstract

PURPOSE:To shorten the forming time of a product by automatically recognizing a work remaining part to a blank and automatically and accurately forming a tool route for the work remaining part. CONSTITUTION:A final tool route Ra1 for generating the product 12 by end mills 4a and 4b which are set based on the form of the product 12, the form of the blank 11 for generating the product 12 and a work condition including the radius r1 of the end mill 4a cutting/working the blank 11. An offset route ROFF1 obtained by offsetting the final tool route Ra1 by the radius r1 of the end mill 4a in a normal direction toward the side of the product 12 is generated, and a difference between the offset route ROFF1 and the form of the product 12 is obtained. The work remaining part K by the end mill 4a is generated based on the difference, and new tool routes Rb1-Rbn for cutting/working the work remaining part K by the new end mill 4b whose radius is smaller tan that of the end mill 4a are generated based on the work remaining part K.

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 a machining program for a numerical control device, and more specifically, to create a machining program for a numerical control device for automatically recognizing a machining remaining portion for a rough material and creating a machining program. It is about the method.

[0002]

2. Description of the Related Art When a product is molded from a rough material by a conventional NC processing machine, the rough material is pre-processed and then post-processed.
In this pre-processing, the shape data of the product and the shape data of the rough material are input to the control unit of the NC processing machine, and the cutting processing conditions such as the radius and the cut amount of the pre-processing end mill are input. Then, the control unit of the NC processing machine creates a tool path for the rough material of the end mill based on these various data. When creating this tool path, it is necessary to determine the tool path so as not to cut the rough material too much with respect to the product shape. For example, various methods have been proposed as shown in Japanese Utility Model Application Laid-Open No. 64-7304. .

When the pre-machining is performed according to the tool path thus obtained, although the rough material is not wasted, there remains an uncut portion that cannot be entered by the end mill, and this uncut portion is the uncut portion. It becomes the unprocessed part in the end mill. This unprocessed portion will be cut using a new end mill with a small diameter.

[0004] Then, the cutting process is carried out by a newly used end mill having a small diameter, in which a new tool path is created for the remaining machining part.

[0005]

By the way, the determination of the unprocessed portion is made based on the estimation of the operator. That is, the operator compares and confirms the shape of the product and the final shape of the rough material cut by the end mill on the screen of the display device to determine at which position and to what size the unprocessed portion remains. It was a thing.

Then, for each of the unprocessed portions thus obtained, a rough material shape for the unprocessed portion is newly created from each of the unprocessed portions and the shape of the rough material. The rough material shape of the unprocessed part is used to create a new tool path for the unprocessed part together with the shape of the product and the cutting processing condition by the newly used end mill having a small diameter.

Therefore, the operator must find the remaining unprocessed portions one by one and newly create a rough material shape for a new unprocessed portion from each of the unprocessed portions and the shape of the rough material. The number of man-hours required to create the tool path is extremely large, which is a problem in reducing the machining time.

Further, when judging the size of one unprocessed portion on the screen of the display device, the operator considers that a newly used tool having a small diameter will be broken, and the operator will make a large unprocessed portion. Define. That is, the unprocessed part that is defined to be a large size becomes the unprocessed part including the already processed part. Therefore, in the tool path created using this unprocessed part, the processed part is also created as part of the tool path. As a result, there is a problem in that the end mill is caused to make useless movements and the processing time becomes long.

The present invention has been made to solve the above-mentioned problems, and its purpose is to automatically and accurately create a tool path for a remaining portion to be machined for a rough material, thereby shortening the molding time of a product. An object of the present invention is to provide a method of creating a machining program for a numerical control device that can be achieved.

[0010]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention includes a shape of a product, a shape of a rough material for molding the product, and a machining including a radius of a tool for cutting the rough material. Create an offset path offset by the radius of the tool in the normal direction toward the product side with respect to the final tool path for product forming by the tool set based on the conditions, and the offset path and the product Obtain the difference from the shape, create a machining remaining part by the tool based on the difference, and based on the machining remaining part, create a new machining for the machining remaining part with a new tool having a smaller diameter than the previous tool. The point is that the tool path is created.

[0011]

[Function] The tool path of the tool for cutting the rough material is set based on the shape of the product, the shape of the rough material for molding the product, and the processing conditions including the radius of the tool for cutting the rough material. To be done. Then, an offset path is created by offsetting the radius of the tool in the normal direction toward the product side from the final tool path among the set tool paths. Then, the unprocessed portion by the tool is created by obtaining the difference between the offset path and the shape of the product. And
A tool path of the tool for cutting the remaining machining portion with a new tool having a smaller diameter than the previous tool is created based on the remaining machining portion.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment embodying the present invention will now be described with reference to FIGS.
It will be described with reference to FIG. FIG. 1 is a block diagram showing the configuration of a processing remainder automatic recognition processing system. The NC control device 1 constituting this system is connected to the AT via the drive circuit 2.
It is connected to the servomotor 3 of the processing device with C (auto tool changer). Then, the NC motor 1 drives and controls the servo motor 3 via the drive circuit 2, and the end mill 4a as a tool connected to the servo motor 3 and the end mill 4b having a diameter smaller than that of the end mill 4a are rotated X , Y, Z axis position control.

The NC control device 1 is also connected to an engineering workstation (CAD / CAM device) 5. Data of the shape of the rough material 11 and the shape of the finished product 12 shown in FIGS. 2 and 3 which are created in advance by the engineering workstation 5 are input. Then, from the engineering workstation 5, processing data for cutting the rough material 11 to form the product 12, data of the shape of the rough material 11, the data of the shape of the product, and the like are output to the NC control device 1. ing.

A keyboard 6 is connected to a central processing unit (hereinafter, simply referred to as CPU) 8 of the engineering workstation 5. Various processing conditions can be input from the keyboard 6 to the CPU 8 and instructions for starting and stopping the system can be issued. A three-dimensional graphics monitor 7 is connected to the CPU 8, and a rough material 11 is attached to the three-dimensional graphics monitor 7.
The processing status, the processing data, the shape of the finished product 12, and the like are displayed.

Further, the engineering workstation 5 has a CPU 8, a main memory 9 in which an automatic control program and the like are stored and processing conditions, an auxiliary in which data such as the shape of the rough material 11 and the shape of the finished product 12 is stored. It is composed of a storage device 10.

Data such as the shape of the rough material 11 and the shape of the finished product 12 input to the CPU 8 are stored in the auxiliary storage device 10. The radius r1 of the end mill 4a, the cutting amount t1 of the end mill 4a, and the pick feed amount (the feed amount of the end mills 4a and 4b with respect to the Z-axis direction) h, which are the processing conditions during the pre-processing, are input by the keyboard 6. . The data of these processing conditions are stored in the auxiliary storage device 10 of the engineering workstation 5. Similarly, the radius r2 of the end mill 4b and the cut amount t2 of the end mill 4b, which are the processing conditions during the post-processing, are also input by the keyboard 6. The data of these processing conditions is also used by the engineering workstation 5.
Are stored in the auxiliary storage device 10.

As shown in FIG. 3, the engineering workstation 5 has an XY section D1 formed by cutting the rough material 11 in parallel with the X and Y axes at intervals of pick feed amount h in the Z axis direction. Define Dn.

Next, as shown in FIG. 4, the CPU 8 controls the shape of the rough material 11, the shape of the product 12, the radius r1 of the end mill 4a and the cut amount t1 of the end mill 4a for each XY section D1 to Dn of the rough material 11. Based on the above, the tool paths Ra1 to Ran (n: integer) by the end mill 4a are created.

The tool paths Ra1 to Ran for each of the XY cross sections D1 to Dn are created as follows. For example, in the XY section D1 shown in FIG. 4, the CPU 8 creates a tool path Ra1 of the end mill 4a (this is called the final tool path) Ra1 that passes through the closest position to the shape of the product 12 without cutting too much. .

After that, the CPU 8 creates the next tool path Ra2 by adding the cutting amount t1 with the final tool path Ra1 as a reference, and then creates the tool path Ra3 by adding the cutting amount t1 to the tool path Ra2. ing. In this procedure, the CPU 8 creates tool paths Ra1, Ra2, Ra3 ... Ran (n: integer) for the end mill 4a to cut the rough material 11.

The product 12 has a recess 12a having a radius r1 which cannot be cut by the end mill 4a. Therefore, in the XY cross section D1, the unprocessed portion K indicated by the diagonal lines due to the end mill 4a is generated.

Thereafter, the CPU 8 creates tool paths Ra1 to Ran in the same procedure as above for the XY cross sections D2 to Dn, and creates preprocessing data for forming the product 12 on the rough material 11. It has become. Thereafter, the CPU 8 outputs these created pre-processing data to the NC control device 1,
The pre-processed data is stored in the NC control device 1.

Next, the CPU 8 heads toward the product 12 side formed by cutting the tool path Ra1 closest to the shape of the product 12, that is, the final tool path Ra1 in each XY section D1 to Dn. An offset route ROFF1 is created by offsetting the radius r1 of the end mill 4a in the normal direction.

Further, the CPU 8 controls the offset route ROFF1 created for each XY section D1 to Dn and each XY section D1 to Dn.
Based on the shape of the product 12 corresponding to each n, it is determined whether the offset route ROFF1 and the shape of the product match.

That is, the shape of the product 12 is subtracted from the offset route ROFF1, and the difference is calculated by the CPU 8. When the CPU 8 determines that there is no difference, the CPU 8 determines that the unprocessed portion K has not occurred in the product 12. When the CPU 8 determines that there is a difference, the CPU 12 determines that the unprocessed portion K has occurred in the product 12.

The product 1 for each XY section D1 to Dn
When the unprocessed portion K occurs for the shape of 2, C
The PU 8 is adapted to create unprocessed data based on the unprocessed part K for each of the XY cross sections D1 to Dn and store it in the auxiliary storage device 10.

Next, the CPU 8 controls each XY section D1 to D.
Tool paths Rb1 to Rbn for cutting the remaining machining portion K generated for each n are created. That is, the CPU 8 has an end mill 4b having a radius r2 smaller than that of the pre-machining, a cutting amount t2 of the end mill 4b,
The shape of the recess 12a in the product 12, each XY cross section D1
The tool paths Rb1 to Rbn of the end mill 4b are created based on the unprocessed data of the unprocessed part K generated for each Dn.

Then, as shown in FIG. 6, for example, the rough material 1
It is assumed that an unprocessed portion K indicated by diagonal lines is generated with respect to the shape of the rough material 11 of the XY cross section D1 in which No. At this time, the portion indicated by the dotted line is the recess 12a in the product 12.
It becomes the shape of. Then, the CPU 8 causes the offset route ROF
A tool path Rb1 with which the radius r2 of the end mill 4b contacts is created based on F1 and the unprocessed portion K of the product 12.

The CPU 8 creates the next tool path Rb2 by adding the cutting amount t2 of the end mill 4b based on the tool path Rb1, and then creates the tool path Rb3 by further adding the cutting amount t2 of the end mill 4b to the tool path Rb2. It is supposed to do. In this procedure, the CPU 8 makes the end mill 4
b is a tool path Rb1, Rb2, for cutting the remaining machining portion K
...... Rbn (n: is an integer) is created.

The tool paths Rb1 to Rbn created for each of the unprocessed portions K of D1 to Dn for each XY section to be post-processed by the above procedure are stored in the auxiliary storage device 10 of the engineering workstation 5. ing.

Next, a method of creating a machining program in the machining residual portion automatic recognition machining system configured as described above will be described with reference to the flowchart of FIG. First,
A radius r1 of the end mill 4a for cutting the rough material 11, a cutting amount t1 of the end mill 4a, a pick feed amount h of the end mill 4a, and the like are input with the keyboard 6 (STEP 1, hereinafter STEP is simply referred to as S). Then, the CPU 8 creates XY cross sections D1 to Dn formed by cutting the rough material 11 in parallel with the XY axis directions at equal intervals in the Z axis direction based on the pick feed amount h (S2).

Then, the CPU 8 cuts the cut XY section D.
Shape of product 12 and end mill 4 corresponding to all 1 to Dn
The tool paths Ra1 to Ran of the end mill 4a are created based on the radius r1 of a and the cut amount t1 (S3). next,
The radius r2, the cutting amount t2, the pick feed amount h, etc. of the end mill 4b for processing the remaining portion to be processed are input using the keyboard 6 (S4). Then, the CPU 8 offsets the tool path Ra1 closest to the product 12 by the radius r1 of the end mill 4a toward the product 12 in the normal direction to create an offset path ROFF1 (S5).

Further, the CPU 8 uses the offset route ROFF1.
And the shape of the product 12, that is, the offset path ROF
The shape of the product 12 is subtracted from F1 and the difference is calculated (S
6). Then, the CPU 8 determines whether or not there is the difference (S7). And the part where the difference occurs is the product 12
CPU8 judges as the unprocessed part K for (S
8), the unprocessed portion K is stored in the auxiliary storage device 10. On the other hand, the portion where no difference is generated is not judged as the unprocessed portion K for the product 12, and the CPU 8 immediately proceeds to S9.
Move to.

Then, the CPU 8 has all the XY cross sections D1 to D1.
It is determined whether or not the unprocessed portion K is stored in the auxiliary storage device 10 for each Dn (S9). All XY cross sections D1
When the processing for each Dn is not performed, the CPU 8 returns to S5 to obtain the unprocessed portion K again, and the obtained unprocessed portion K is obtained.
Is stored in the auxiliary storage device 10 is repeated.

When the unprocessed portion K is stored in the auxiliary storage device 10 for all the XY cross sections D1 to Dn, the CPU
Reference numeral 8 creates tool paths Rb1 to Rbn of the end mill 4b based on the machining conditions for the machining residual portion K for each of the XY cross sections D1 to Dn (S10). Then, the CPU 8 causes each XY section D
Tool paths Rb1 to Rbn for the remaining machining portion K for each 1 to Dn
It is determined whether or not has been created (S11).

When the tool paths Rb1 to Rbn for the remaining machining portion K for each of the XY cross sections D1 to Dn are not created, CP
U8 shifts to S10 again and creates tool paths Rb1 to Rbn for the unprocessed portion K of each XY cross section D1 to Dn, and each X.
Tool path R for the remaining machining section K for each Y section D1 to Dn
When b1 to Rbn are created, the CPU 8 ends the creation of the program.

The program, which is the machining data created by the engineering workstation 5 in the above procedure, is transmitted to the NC controller 1. Then, when the system is operated, the NC controller 1 controls the servomotor 3 via the drive circuit 2 based on the tool paths Ra1 to Ran of the end mill 4a created for each XY section D1 to Dn, and the end mill 4a. Is moved in the X and Y directions while rotating, to cut the rough material 11.

Further, the rough material 11 is based on the tool paths Ra1 to Ran of the end mill 4a set for each of the XY cross sections D1 to Dn.
When the pre-processing of 1 is completed, the NC control device 1 removes the end mill 4a by ATC and replaces it with the end mill 4b.

After that, the XY stored in the NC control device 1 is stored.
The NC controller 1 controls the servomotor 3 via the drive circuit 2 on the basis of the tool paths Rb1 to Rbn for the unprocessed portion K set for each of the cross sections D1 to Dn, and rotates the end mill 4b in the X and Y directions. Then, the rough material 11 is cut.

Then, when the rough material 11 is cut based on the processing paths Rb1 to Rbn based on the processing remaining portion K in each of the XY cross sections D1 to Dn, the post processing is ended, and as a result, the molding of the product 12 is ended. .

Therefore, the product 1 for each XY section D1 to Dn
The offset path ROFF1 is created by offsetting the radius r1 of the end mill 4a in the normal direction toward the product 12 side formed by cutting with respect to the final tool path Ra1 of 2. And this offset route ROFF1 and product 12
It is possible to automatically recognize the unprocessed portion K by comparing with the shape. As a result, the unprocessed portion K can be automatically cut and removed, so that the product 12 can be molded at high speed and the molding time can be shortened.

Although this embodiment did not include a finishing step for improving the dimensional accuracy of the product 12, the present invention is also applied to the case where the shape of the product 12 is formed in consideration of the finishing amount. It is possible to apply.

Further, in this embodiment, the end mill 4
Although it was possible to completely cut the unprocessed part K by b, if the unprocessed part K is also generated by the end mill 4b, an end mill having a smaller diameter than the end mill 4b is set and further processed by this end mill. It is also possible to cut the remaining part.

[0044]

As described above in detail, according to the present invention,
Automatically process the remaining part of the rough material based on the offset path offset by the radius of the tool in the normal direction toward the formed product side with respect to the final path of the tool for forming the product, and the product shape Because you can recognize
There is an excellent effect that it is possible to efficiently create a tool path for the unprocessed portion and to shorten the time for molding the product from the rough material.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a processing remainder automatic recognition processing system according to the present invention.

FIG. 2 is a perspective view showing a completed product.

FIG. 3 is a perspective view showing that the shape of the product is matched with that of the rough material and that the rough material is cut parallel to the XY axes.

FIG. 4 is a plan view showing a state in which a tool path is set for one cross section of a rough material.

FIG. 5 is an explanatory diagram showing that an offset path is created based on a final tool path.

FIG. 6 is an explanatory diagram showing that a tool path is created with respect to an unprocessed portion of a cross section of a rough material.

FIG. 7 is a flowchart illustrating a procedure for creating a machining program.

[Explanation of symbols]

4a, 4b ... End mill as tool, 11 ... Rough material, 1
2 ... Product, r1 ... Radius, Ra1 ... Final tool path, ROFF1 ...
Offset path, K ... Remaining part of machining, Rb1 to Rbn ... Tool path

Claims (1)

[Claims] 1. For product molding by the tool, which is set on the basis of the shape of the product, the shape of the rough material for molding the product, and the processing conditions including the radius of the tool for cutting the rough material. Create an offset path offset by the radius of the tool in the direction of the normal to the final tool path of, and find the difference between the offset path and the product shape,
Based on the difference, create a machining remainder by the tool, and based on the machining remainder, create a new tool path for cutting the machining remainder with a new tool having a smaller diameter than the previous tool. A method for creating a machining program for a numerical control device, characterized in that