JPH11345013A - Method and device for generating tool route for nc working - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily prepare NC data capable of evading interference between a chuck and a work by selecting data reducing a working margin from tool route data and virtual tool route data and calculating practical tool route data. SOLUTION: The post working surface data of a post working surface curve by a working tool 51 for a work W and data related to the sorts, shapes and dimensions of the tool 51 and a chuck 52 are prepared and stored. Tool route data for generating the route of a tool center 01 are calculated based on the post working surface data and the tool radius of the tool 51 and stored. Virtual tool route data for generating the route of the center 01 of the tool 51 are calculated when the outer peripheral edge of the tip of the chuck 52 is moved by offsetting it only by a prescribed distance from the post working surface curve so as not to interfere with the preworking surface curve L2 of the work W. Then, data reducing a working margin are selected from the tool route data and the virtual tool route data and tool route data Dt5 for generating a practical tool route T5 are calculated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for generating a tool path for NC machining, which can prevent a chuck for gripping a tool from colliding with a workpiece in machining by cutting. It is about.

[0002]

2. Description of the Related Art In machining with an NC milling machine or a machining center, when a workpiece having a complicated shape is machined on a workpiece such as a die (hereinafter referred to as a workpiece),
Using a computer (CAD system) to support the design work, the processed surface shape is converted into electronic data (CAD data)
And the CAD data is stored in a storage device of the CAD system. Then, the CAD data is output to a computer (CAM) that supports the creation of machining data, and is used for creating path data of the machining tool based on the subsequent (final) machining surface data. As one type of path data of a machining tool, there is data called NC data, and this NC data is used for unmanned operation of the above-mentioned machining center. The workpiece is fixed to the machining table of the machining center, and NC data in which tool path data (post-processing surface data) and machining conditions are recorded are read into a reading device of the machining center, and the tool is moved on a predetermined path to move the workpiece. Perform cutting.

[0003] In unmanned machining using NC data of a workpiece by such a machining center, one of the technical problems of creating NC data is to avoid interference between a chuck for attaching a machining tool to a spindle head of the machining center and the workpiece. There is a problem to do. This interference does not occur when the workpiece is pre-processed, but frequently occurs in post-processing (finishing). The reason for this is that the display screen 1 of the display device 16 of the CAM system shown in FIGS.
6a.

[0004] The pre-processing of the workpiece W is performed using a generally large ball end mill 61 as shown in FIG.
The front (rough) processing by the ball end mill 61 is performed by adding the center O of the mill 61 to the distance G obtained by adding the post-processing allowance δ to the radius r from the rear (finishing) processing surface curve L1 to the cutting edge of the center point O of the ball mill 61. By moving along the movement trajectory offset by (G = r + δ), that is, along the tool path T, the work W is performed while leaving the post-processing allowance δ, and the pre-processing surface curve L2 is formed. In this pre-processing, a large diameter and long ball mill 61 can be used as the ball mill 61.
2 does not interfere.

On the other hand, the workpiece W after pre-processing is shown in FIG.
Ball end mill 5 for short post-processing with small diameter as shown in
1 is post-processed. In this post-processing, the lower end outer peripheral edge 52a of the chuck 52 of the ball mill 51 is moved below the uppermost part of the front processing surface curve L2, so that the chuck 52 may interfere with the front processing surface curve L2 of the work W. Get up. That is, in FIG.
When the center point O1 of the first tool moves along the tool path T1, the outer peripheral edge 52a of the lower end of the chuck 52 also moves along the tool path T1.
The chuck 52 is moved in front of the workpiece W from the upper movement path T2 to the position P1 where the lower peripheral edge 52a of the lower end of the chuck 52 comes into contact with the front processing surface curve L2 from the upper movement path T2. There is no interference with the processing surface curve L2. However, the lower end outer peripheral edge 52a of the chuck 52 is moved from the position P1 to the lower end outer peripheral edge 5a of the chuck 52.
Interference occurs until the position 2a leaves the pre-processed surface curve L2, and no interference occurs after the outer peripheral edge 52a is separated to the right from the position P2.

For this reason, there is a conventional CAM provided with a calculation function for automatically avoiding interference between the chuck 52 and the work W to the CAM. In the case where the interference avoidance operation is included in the NC data by the automatic avoidance calculation function of the CAM, the avoidance operation of the chuck 52 is limited to only simple avoidance in the Z-axis plus direction (direction toward the work upper space). That is, as shown in FIG.
The chuck 52 is moved by a predetermined distance in the Z-axis plus (upward) direction as indicated by an arrow before moving to the position P1 at which a collides with the work W, and thereafter, the ball mill 51 is moved by a predetermined distance that does not interfere with the work W. When the ball mill 51 moves in the X-axis right direction, the ball mill 51 moves in the Z-axis minus direction. The reason for this is that even if the chuck 52 is moved in the X-axis direction to perform the avoiding operation without moving the chuck 52, it is extremely necessary to provide a function of determining whether the chuck 52 may interfere with the work W again. Because it is difficult.

[0007]

In the conventional function of automatically avoiding the interference of the chuck 52 with the workpiece W by the CAM, for example, in the case of a flat end mill that cannot cut in the minus direction of the Z-axis, the function of automatically creating NC data by the CAM There is a problem that can not be used. That is, in FIG. 11, the flat end mill was once raised in the Z-axis plus direction, and then the chuck 52 was moved in the X-axis direction, moved to a position where the chuck 52 did not interfere, and the flat end mill was further moved in the Z-axis minus direction. rear,
Finishing the surface of the flat end mill with the post-processing surface curve L
It is difficult to accurately move to the bottom surface of the first. If this movement is not performed accurately and the movement amount of the flat end mill increases, the work and the flat end mill will be damaged. For this reason, it is necessary for a worker (CAM operator) who creates the NC data to incorporate a more appropriate avoidance operation into the NC data by manual operation, and the burden on the operator increases.
There is a problem that it takes too much cost to create NC data.

Further, since the path length of the working tool is increased by frequently using the simple avoiding operation in the plus direction of the Z axis, the work is inefficiently machined, and the net machining time during the machining operation is reduced. And the efficiency of machining operations cannot be improved.

Further, since the range of the avoiding operation is set with a margin to some extent, the area that cannot be post-processed by the ball end mill 51 is widened, and the area of further processing using a more expensive processing tool than the ball end mill 51 is performed. Therefore, there is a problem that the processing cost cannot be suppressed as a whole.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems in the prior art, to easily create NC data capable of avoiding interference between a chuck and a work, and to improve the efficiency of machining work. An object of the present invention is to provide a tool path generating method for NC machining and an apparatus therefor, which can improve the machining cost of a workpiece.

[0011]

In order to achieve the above object, according to the first aspect of the present invention, a post-processing surface data on a post-processing surface curve (L1) of a work (W) by a processing tool (51) is provided. (D1) is created and storage means (2
(2, 34) and the machining tool (5
1) A second step of creating data relating to the type, shape and dimensions of the chuck (52) holding the same and storing it in the storage means (22), and the post-processing surface data (D1)
The movement trajectory of the tool center (O1), that is, the tool path data (Dt1) for generating the tool path (T1) is calculated based on the tool path (T1) and the tool radius (r) of the processing tool (51).
A third step to be stored in 2) and the chuck (52)
The outer peripheral edge (52a) of the post-processing surface curve (L1)
From the center (O1) of the machining tool (51) when the workpiece is moved so as not to interfere with the pre-machining surface curve (L2) of the workpiece while being offset from the workpiece by a predetermined distance (E), that is, a virtual tool path (T4). ) To generate virtual tool path data (Dt4), and the tool path data (Dt) for processing the post-processing surface curve (L1).
1) selecting a tool path data with a smaller machining allowance from the virtual tool path data (Dt4) and calculating tool path data (Dt5) for generating an actual tool path (T5); Consists of

According to the second aspect of the present invention, in the fourth step of the first aspect, the chuck (52) is regarded as a tool similar to the working tool (51), and the pseudo tool (5) is used.
The processing tool (5) obtained by offsetting the post-processing surface curve (L1) by a predetermined distance (E) and translating it so as not to interfere with the pre-processing surface curve (L2) of the work.
The virtual tool path data (Dt4) for generating the virtual tool path (T4) of 1) is calculated.

According to a third aspect of the present invention, in the fourth step of the second aspect, the predetermined distance (E) is determined by the tool radius (R) of the pseudo tool (52) and the tool radius (R) of the processing tool (51). Based on the tool radius (r), the post-machining allowance (δ) of the pre-machining surface curve (L2) and the set separation distance η (η> 0), the following arithmetic expression E = R−r + δ + η is used. ing.

According to the fourth aspect of the present invention, the fourth step according to the second or third aspect is characterized in that:
1) calculating offset surface data (D3) for generating an offset surface curve (L3) at a position offset by the predetermined distance (E) from the surface curve (L1); ) Is moved in parallel with the tool center (O1) of the working tool (51) and the tool center (O2) of the dummy tool (52) in the Z-axis minus direction, that is, in the cutting direction of the workpiece. Calculating the virtual machining protection surface data (D4) for generating the virtual machining protection surface curve (L4), and using the virtual machining protection surface data (D4) and the tool radius (r) of the machining tool. And a step of calculating virtual tool path data (Dt4) for generating the path (T4).

[0015] According to the fifth aspect of the present invention, the second and third aspects are provided.
Or the fourth step described in (4) is performed by using the chuck (5
The outer peripheral edge (52a) of the tip of 2) is a pre-processed surface curve (L2).
Calculates chuck path data (Dt6) for generating an offset path (T6) of the chuck (52) when it is offset by a set separation distance (η) from the axis and is translated so as not to interfere with the pre-processed surface curve (L2). And virtual tool path data (Dt1) for generating a virtual tool path (T1) of the center point (O1) of the processing tool (51) when the chuck is moved along the chuck path data (Dt6). And the post-processing surface curve (L
1) selecting the path data with a small machining allowance from the tool path data (Dt1) and the virtual tool path data (Dt1) to calculate the tool path data (Dt5) for generating the actual tool path (T5); Consists of

[0016] According to the invention described in claim 6, in claim 1,
In 2, 3, 4 or 5, the post-processing surface curve (L1) and the pre-processing surface curve (L1) in the first to fifth steps.
2), the shapes of the processing tool (51) and the chuck (52), the tool radius (r) of the processing tool (51), the tool center (O1),
Tool path (T1), tool center (O2) of pseudo tool (chuck), tool radius (R) of pseudo tool (52), tool path (T1) of post-processing surface curve, virtual tool path (T4) and actual The tool path (T5) is displayed on the screen of the display device as needed.

According to the seventh aspect of the present invention, the work (W)
Machining surface curve (L) by the machining tool (51)
First means (32, 3) for creating post-processing surface data (D1) relating to 1) and storing it in the storage means (22, 34)
3, 34) and a second means (3) for creating data relating to the type, shape and dimensions of the working tool (51) and the chuck (52) for gripping it and storing the data in the storage means (22).
0, 31), the post-processing surface data (D1), and the tool radius (r) of the processing tool (51).
A third means (15, 21) for calculating a movement trajectory, that is, tool path data (Dt1) for generating a tool path (T1) and storing the calculated data in a storage means (22);
The outer peripheral edge (52a) of the tip of 2) is defined by the post-processing surface curve (L).
A locus of movement of the center (O1) of the processing tool (51) when the workpiece is moved so as not to interfere with the pre-process surface curve (L2) of the work while being offset by a predetermined distance (E) from 1);
That is, the fourth means (13, 21) for calculating the virtual tool path data (Dt4) for generating the virtual tool path (T4).
And selecting the tool path data with a smaller machining allowance from the tool path data (Dt1) and the virtual tool path data (Dt4) for processing the post-processing surface curve (L1), and selecting the actual tool path. Fifth means (14, 21) for calculating tool path data (Dt5) for generating (T5).

According to an eighth aspect of the present invention, in the seventh aspect, the post-processing surface curve (L1), the pre-processing surface curve (L2), and the processing tool (51) in the first to fifth means.
And the shape of the chuck (52), the tool radius (r) of the processing tool (51), the tool center (O1), the tool path (T1), the tool center (O2) of the pseudo tool (chuck), and the pseudo tool (5)
Display means (16) for displaying the tool radius (R) of 2), the tool path (T1) of the post-processing surface curve (L1), the virtual tool path (T4), and the actual tool path (T5) as necessary. It has.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. First, an outline of a tool path generating device for NC machining according to the present invention will be described with reference to FIG.

In FIG. 1, reference numeral 11 denotes a main body of the tool path generating apparatus. The main body 11 is connected to data input sections 12A and 12B inside and outside the factory. The external data input units 12A and 12B are provided with post-processing surface data of the workpiece W to be processed, types, shapes and dimensions of processing tools and chucks.
Alternatively, various data such as processing conditions are input. The tool path generating device main body 11 moves the chuck so as not to interfere with the pre-machining surface curve based on the post-machining surface data of the work, the machining tool, and data on the shape and dimensions of the chuck holding the workpiece. In this case, a virtual machining protection surface data calculation unit 13 for calculating virtual machining protection surface data processed by the machining tool is provided. Further, the tool path generating device main body 11 includes a calculation unit 14 that selects the surface data having a smaller processing allowance from the post-processing surface data and the virtual processing protection surface data and calculates the actual processing surface data. A path data calculation unit 15 is provided for calculating path data of a processing tool from actual processed surface data.

A display device 16 is connected to the two surface data calculation units 13 and 14. With this display device 16, a post-processing surface curve based on the post-processing surface data,
The virtual machining protection surface curve based on the virtual machining protection surface data, the actual machining surface curve based on the actual machining surface data, and the tool path based on the machining tool path data are, for example, two-dimensional plane coordinates of X and Z axes or , X, Y, Z axes. The route data calculation unit 1
5 is connected to a post-processing unit 17 that converts tool path data into machine data (NC data) corresponding to an NC processing machine 18 that uses the tool path data.

Next, details of the tool path generating device will be described with reference to FIG. The tool path generating device main body 11 is configured by a main body of a computer (hereinafter, referred to as “CAM main body 11”). The CAM main body 11 has an input unit 12A in a factory.
A keyboard 30, a mouse interface (hereinafter, referred to as "mouse") 31, and a computer (hereinafter, referred to as "CAD32") for creating post-processed surface (drawing) data of a work arranged in a factory are connected. . The display device 16 is, for example, a CRT or a liquid crystal display device, and has a screen for constructing at least a two-dimensional plane in the vertical and horizontal directions, and can display various characters and graphics in color or monochrome on the screen. is there.

The CAM body 11 has a central processing unit 21, a random access memory (RAM) 22 as a volatile temporary storage unit, a read-only memory (ROM) 23 as a first nonvolatile storage unit, A hard disk drive 24 as a non-volatile storage unit 2 and a recording medium 3 which is a third non-volatile storage unit and is also an external data input unit
4, a drive reading device 25, an input interface unit 26, and an output interface unit 27. These physical devices or hardware resources (21 to 27) are interconnected via a data bus 28.

The central processing unit 21 is an operation processing unit including an operation processing unit such as a CPU, and constitutes the virtual machining protection surface data operation unit 13, the actual machining surface data operation unit 14, and the path data operation unit 15. . The central processing unit 2
1 performs various processes such as display control for the display device 16 according to various programs (software) stored in the RAM 22, the ROM 23, or the hard disk device 24.

The RAM 22 secures a program resident area for resident programs such as application software and a work area for application software and / or system software. The RAM 22 has NC
A processing tool 51 used in the processing machine 17 and its chuck 52
Numerous data relating to the type, shape, or size of the object, processing condition data, and the like are stored. The ROM 23 contains C
The minimum programs and data necessary for starting the AM main body 11 are stored.

The hard disk drive 24 is pre-installed with a system management program called an OS and a standard application program. An example of the system management program is, for example, "Windows" (trade name) provided by Microsoft Corporation in the United States.

The drive reading device 25 of the recording medium 34 reads data from a recording medium 34 such as a magnetic recording tape or a rewritable optical disk on which post-processed surface data created by the CAD 33 as the input unit 12B outside the factory is recorded. Magnetic recording medium 3 such as a magnetic recording tape drive, a rewritable optical disk drive, and a floppy disk
A floppy disk drive that reads data from 4,
Any other media data reading device may be used. However,
In the present embodiment, it is preferable to use a magnetic recording tape drive or a rewritable optical disk drive, which is generally considered to have a large recording capacity, because a large amount of graphic data is handled.

The input interface unit 26 is an input control device that converts commands and data from the keyboard 30 and the mouse 31 into digital data and transfers the digital data to the central processing unit 21. The output interface unit 27 converts digital data related to image display controlled or newly generated by the central processing unit 21 into a digital or analog electric signal suitable for display on the screen of the display device 16,
An output control device for sequentially transferring the electric signals to the display device 16. The output interface unit 27
The path data of the machining tool calculated based on the actual machining surface data transferred and controlled by the central processing unit 21 is output to the post-processing unit 17 and converted into NC data suitable for the NC machine 18.

Next, the operation of creating NC data using the tool path generating device for NC machining configured as described above will be described. Note that this embodiment is directed to an NC machining tool path generation device that generates a tool path for three-dimensional curved surface machining in die manufacturing, and uses three simultaneous ordinary axes (X-axis, Y-axis) without tool posture control. (Axis, Z axis) Control processing is performed, and a description will be given of an example in which a ball end mill having a spherical tip at the time of rotation is used as a processing tool.

First, a three-dimensional CAD in a factory shown in FIG.
The drawing data relating to the post-processing surface of the work W is created using the reference numeral 32. This operation is performed by, for example, a conventionally well-known procedure. 3D graphic data created by CAD32,
That is, the post-processed surface data D1 is represented as a numerical sequence inside the computer of the CAD 32, and the three-dimensional post-processed surface data D1 is stored in the storage device (not shown) of the CAD 32. (Step S1 in FIG. 3) Next, the input unit 12A
The post-processing surface data D1 of the work stored in the storage device (not shown) of the CAD 32 is read out using the keyboard 30 and the mouse 31, and is stored in the work area of the RAM 22 of the CAM body 11. At this time, the recording medium 34 on which the post-processed surface data D1 of the work created by the CAD 33 outside the factory is recorded is inserted into the drive reading device 25 and the RAM is inserted.
The data D1 may be stored in the work area 22.

Next, the post-processed surface data D1 of the work W stored in the work area of the RAM 22 of the CAM body 11
Is read into the central processing unit 21 by operating the keyboard 30 and the mouse 31, and the post-processing surface curve L1 based on the data D1 is displayed on the display screen 1 of the display device 16 as shown in FIG.
6a. (Step S2 in FIG. 3) In this embodiment, a three-dimensional figure can be displayed on the display screen 16a based on the three-dimensional post-processing surface data D1 described above.
Only a part of a vertical two-dimensional plane of the X-axis and the Z-axis is illustrated because it is complicated and the contents are difficult to understand. In FIG. 4, a post-processing surface curve L1 in a vertical two-dimensional plane based on the post-processing surface data D1 of the work W is displayed. Further, a pre-processed surface curve L2 based on pre-processed surface data D2 processed by the pre-processed ball end mill 61 described in the section on the prior art
Is also displayed.

Next, by operating the keyboard 30 and the mouse 31 of the input unit 12A, the ball end mill 51 used for the post-processing and the shape of the chuck 52 or the shape of the chuck 52 are determined from various data on the processing tool and the chuck stored in the RAM 22. The data relating to the dimensions are read out, read into the central processing unit 21, and the ball end mill 51 and the chuck 52 are displayed on the screen 16a of the display device 16 as shown in FIG. (Step S3 in FIG. 3) In this embodiment, the distance from the tool center point O1 of the ball end mill (machining tool) 51 to the cutting edge is defined as the tool radius r of the ball end mill (machining tool) 51, and the chuck 52 is indicated by a chain line in FIG. As shown by a pseudo ball end mill (hereinafter also referred to as a pseudo tool 52)
From the center point O2 of the pseudo tool 52
The distance from the center point O1 of the ball mill 51 to the pseudo tool 52
The distance in the Z-axis direction up to the center point O2 of FIG.

When the machining tool 51 is input and displayed as described above, the tool path data Dt1 is calculated by the central processing unit 21 using the radius r and the post-machining surface data D1, and the tool path T1 is calculated based on the data Dt1. Is displayed.

In order to prevent the tip 52a of the simulated tool (chuck) 52 from always interfering with the pre-processed surface curve L2, the simulated tool (chuck) must be located in the area where the chuck interferes as shown by a solid line in FIG. (Chuck) 52
The requirement to move the leading end 52a along a predetermined movement trajectory slightly separated from the pre-machining surface curve L2 may be considered.

Therefore, in this embodiment, first, the post-machining surface data D1 and the machining tool (end mill) 5
1 and the radius r and R of the pseudo tool (chuck) 52, the tool interval H, the post-processing allowance δ, and the separation distance η of the pseudo tool 52 from the pre-processing surface curve L2, the virtual processing protection surface data calculation unit 13 Offset surface data D3 offset from the post-processing surface curve L1 by a predetermined distance E (= R−r + δ + η) is calculated, and an offset surface curve L3 based on the offset surface data D3 is displayed on the screen 16a as shown in FIG. You. (Step S4 in FIG. 3) Next, based on the data D3 of the offset surface curve L3 described above, the data arithmetic unit 13 moves the curve L3 by a predetermined distance in the Z-axis minus direction as shown in FIG. , 52, the virtual machining protection surface data D4 for displaying the virtual machining protection surface curve L4 moved downward by the tool interval H is calculated, and the curve L4 is displayed on the screen 16a. (Step S5 in FIG. 3) When the center point O1 of the processing tool 51 is moved so as to be in contact with the virtual processing protection surface curve L4 obtained in this way, the leading edge of the pseudo tool (chuck) 52 52
It can be seen that a does not interfere with the pre-processed surface curve L2 of the work W. Therefore, based on the virtual machining protection surface data D4 and the radius r, the movement path of the center point O1 of the machining tool 51 when the virtual machining protection surface curve L4 is apparently machined by the tool path data calculation unit 15, that is, the tool path. T4
Is calculated, and the tool path data Dt4 for generating
The tool path T4 is displayed in a.

Next, based on both surface data D1 and D4 of the post-processing surface curve L1 and the virtual processing protection surface curve L4, data D1 or D4 with a small processing allowance by the processing tool 51 is selected by the data calculation unit 14. Then, as shown in FIG. 7, the processing surface data D5 for generating the actual processing surface curve L5 is calculated, and the actual processing surface curve L5 is displayed on the screen 16a. (Step S6 in FIG. 3) Next, based on both the tool path data Dt1 and Dt4 of the post-processing surface curve L1 and the virtual processing protection surface curve L4, data Dt1 with a small processing allowance by the processing tool 51 by the data calculation unit 15 by the data calculation unit 15. Alternatively, Dt4 is selected, the actual path data Dt5 of the machining tool 51 is calculated as shown in FIG. 7, and the actual tool path T5 is displayed on the screen 16a.
(Step S7 in FIG. 3) Finally, the data Dt5 of the actual tool path T5 described above is converted into machine data (NC data) corresponding to the NC processing machine 18 to be used by the post-processing unit 17. (Step S8 in FIG. 3) FIGS. 7 and 8 show the path T5 of the tool 51 in a two-dimensional plane only in the Z-axis direction and the X-axis direction. Is the X axis, Y axis, Z
Since the surface is a three-dimensional curved surface in the axial direction, the tool path data Dt5 is calculated for all three axial directions. Then, the three-dimensional tool path data Dt5 is transferred to the post-processing unit 17.
Into NC data, and based on this, the processing machine 18
The chuck 52 is operated by machining the workpiece.
It is possible to process a desired three-dimensional surface of the work while avoiding interference with the pre-process surface curve L2 of the work W.

FIG. 8 shows the range of the pre-machined surface curve L2 that remains without machining when the machining tool 51 is moved along the actual machining tool path T5. The uncut pre-processed surface curve L2 is cut by finishing using another processing tool.

Next, the effects of the tool path generating device configured as described above will be listed together with the configuration. (1) In the embodiment, the offset surface curve L3 offset from the post-processing surface curve L1 by a predetermined distance E (= R−r + δ + η) is displayed on the screen, and the offset surface curve L3 is displayed on the processing tool 51 and the pseudo tool 52. Center point O1,
The virtual machining protection surface curve L4 is displayed by moving in the Z-axis minus direction by the tool interval H of O2, and the post-machining surface curve L is displayed.
1 and a curve with a small machining allowance are selected from the virtual machining protection surface curve L4, a post-machining surface curve L5 is displayed, and a tool path T5 for machining the surface curve L5 is calculated to generate NC data. . Therefore, the workpiece W of the chuck 52 can be moved without moving the machining tool 51 in the Z-axis plus direction.
Tool path data D5 for avoiding interference with the tool can be automatically and quickly generated.

(2) In the above embodiment, each surface curve L
1, L2, L3, L4, L5 and tool paths T1, T4,
Since T5 is displayed on the display screen 16a, the presence or absence of interference between the chuck 52 and the work W can be confirmed on the screen 16a.

(3) In the above embodiment, the processing tool 15
Is a method in which only a part of the original tool path T1 is replaced with a virtual tool path T4 having a smaller cutting amount, and therefore, the path T5 may be moved to a direction where the cutting amount of the working tool 51 is larger than the tool path T1. Absent. Therefore, the present invention can be applied to the creation of path data of a machining tool that cannot cut in the minus direction of the Z-axis unlike a flat end mill.

(4) In the above embodiment, the processing tool 15
Is a method in which only a part of the original tool path T1 is replaced with a virtual tool path T4 having a small cutting depth, so that the area of the pre-processed surface that is not cut by the processing tool 51 is minimized, and is therefore more expensive. Since the machining surface area in the subsequent process using a simple machining tool is reduced, the cost of the machining tool for the work can be reduced.

Next, another embodiment of the present invention will be described. -Pre-processed surface data D for displaying the pre-processed surface curve L2
Offset surface data D3 offset by a predetermined distance E from 2 may be calculated, and an offset surface curve L3 may be displayed based on this data D3.

Although not shown, the outer periphery 52a of the tip of the chuck 52 is offset from the pre-processed surface curve L2 by a set separation distance η and is moved in parallel so as not to interfere with the pre-processed surface curve L2. The process of calculating the chuck path data Dt6 for generating the offset path T6, and the center point O1 of the machining tool 51 when the chuck is moved along the chuck path data Dt6.
Tool path data Dt for generating the virtual tool path T4 of FIG.
4 and the tool path data Dt1 of the post-machining surface curve L1 and the path data with a small machining allowance are selected from the virtual tool path data Dt4 to obtain the actual tool path T5.
And a process of calculating the tool path data Dt5 for generating the data.

The post-processing surface curve L1 is usually created by a CAD system, and its three-dimensional figure is confirmed on the screen. If a tool for pre-processing is selected, pre-processing surface data D2 is calculated from the post-processing surface curve L1, and the curve L2 is displayed on the screen. Such data D1, D2
Is read by the drive reading device 25 of the tool path generating device main body 11 after recording the recording medium 34, and the tool path data for processing the series of post-processing surfaces L5 described above without displaying the data on the screen 16a. D7 can also be calculated. However, by displaying various data on the screen 16a, the presence or absence of interference of the chuck 52 with the work can be visually confirmed.

The work surface of the work includes a curved surface, a flat surface, and the like. The processing tool is not only a ball end mill but also a cylindrical end such as a flat end mill other than a spherical end mill or a radius end mill. In addition, there is a type in which the outer peripheral portion of the tip has a rounded corner, and a type in which the tip portion has a spheroidal shape such as an elliptical end mill.

Although CAD and CAM are used in the above embodiment, processing may be performed using a general personal computer.

[0047]

Since the present invention is configured as described above, it has the following effects. According to the first aspect of the present invention, it is possible to easily create NC data capable of avoiding interference between the chuck and the work, to improve the efficiency of the processing operation, and to reduce the processing cost of the work. Reduction can be achieved.

According to the invention described in claim 2, according to claim 1
In addition to the effects described in the above, in the fourth step, the chuck is regarded as a pseudo tool similar to a machining tool, so that the calculation of virtual tool path data for generating a virtual tool path can be easily performed. .

According to the invention described in claim 3, according to claim 2
In addition to the effects described in the above, the predetermined distance can be easily calculated by the arithmetic expression E = R−r + δ + η. According to the fourth aspect of the present invention, in addition to the effects of the second or third aspect, it is possible to easily calculate virtual tool path data for generating a virtual tool path.

According to the fifth aspect of the present invention, in addition to the effects of the second, third or fourth aspect of the present invention, it is possible to simplify the calculation process of virtual tool path data for generating a virtual tool path. it can.

According to the invention described in claim 6, the post-processing surface curve, the pre-processing surface curve, the shapes of the processing tool and the chuck,
The tool radius of machining tool, tool center, tool path, tool center of pseudo tool (chuck), tool radius of pseudo tool, tool path of post-processing surface curve, virtual tool path and actual tool path are displayed on the display screen. Since it is displayed, it is possible to confirm whether or not chuck interference occurs while observing the actual tool path generation process.

[Brief description of the drawings]

FIG. 1 is a schematic block circuit diagram showing a tool path generating device for NC machining according to the present invention.

FIG. 2 is a block circuit diagram of a tool path generation device.

FIG. 3 is a flowchart showing a process of generating NC data.

FIG. 4 is a front view showing a display screen.

FIG. 5 is a front view showing a display screen.

FIG. 6 is a front view showing a display screen.

FIG. 7 is a front view showing a display screen.

FIG. 8 is a front view showing a display screen.

FIG. 9 is a front view showing a display screen.

FIG. 10 is a front view showing a display screen.

FIG. 11 is a front view showing a display screen.

[Explanation of symbols]

11: tool path generating device main body, 12A: input unit in factory, 12B: input unit outside factory, 13: virtual processing protection surface data calculation unit, 14: actual processing surface data calculation unit, 1
5: processing tool path data calculation unit, 16: display device, 1
6a: display screen, 17: post-processing unit, 18: NC processing machine, 51: ball end mill for post-processing, 52: mill 5
No. 1 chuck, 52a: outer peripheral edge, O1: center point of processing tool (ball end mill) 51, O2: center point of pseudo tool (chuck 52), L1: post-processing surface curve, D1: post-processing surface data, T1 ... The path of the center point O1 of the processing tool 51 necessary for processing the post-processing surface curve L1, W... Work, r.
Radius of the ball end mill 51, R: radius of the pseudo tool (chuck 52), H: tool interval between the tool center points O1, O2,
L3: Work surface offset curve, D3: Work surface offset data, E: Offset amount between post-work surface curve L1 and work surface offset curve L3, η: Set separation distance between front work curve L2 and pseudo tool (chuck 52), L4: virtual machining protection surface curve, D4: virtual machining protection surface data, T
4: Path of the center point O1 of the processing tool 51 required for processing the virtual processing protection surface curve L4, L5: Actual processing surface curve,
D5: actual machining surface data, T5: path of the tool center point O1 necessary for machining of the actual machining surface curve L5.

Claims (8)

[Claims] 1. A processing tool (51) for a workpiece (W).
A first step of creating post-processing surface data (D1) relating to the post-processing surface curve (L1) and storing it in the storage means (22, 34); a processing tool (51) and a chuck (52) for gripping it A second step of creating data relating to the type, shape and dimensions of the tool and storing the data in the storage means (22), and the tool center based on the post-processing surface data (D1) and the tool radius (r) of the working tool (51). (O1), that is, the tool path data (Dt) for generating the tool path (T1)
A third step of calculating 1) and storing it in the storage means (22); and offsetting the outer peripheral edge (52a) of the tip of the chuck (52) from the post-processing surface curve (L1) by a predetermined distance (E). Center (O) of the working tool (51) when moved so as not to interfere with the pre-work surface curve (L2) of the work.
A fourth process of calculating the movement trajectory of 1), that is, the virtual tool path data (Dt4) for generating the virtual tool path (T4); and the tool path data (D1) for processing the post-processing surface curve (L1). Dt1) and the virtual tool path data (Dt
4) selecting a tool path data with a smaller machining allowance from (5) and calculating a tool path data (Dt5) for generating an actual tool path (T5); Method. 2. In the fourth step, the chuck (52) is regarded as a tool similar to a working tool (51),
The processing tool (51) when the pseudo tool (52) is translated by a predetermined distance (E) from the post-processing surface curve (L1) so as not to interfere with the pre-processing surface curve (L2) of the work. The tool path generating method for NC machining according to claim 1, wherein virtual tool path data (Dt4) for generating the virtual tool path (T4) is calculated. 3. In the fourth step, the predetermined distance (E) is a tool radius (R) of the pseudo tool (52), a tool radius (r) of the working tool (51), and the pre-machining surface curve (R). L
2) The tool path generating method for NC machining according to claim 2, wherein the following arithmetic expression E = R-r + δ + η is calculated based on the post-machining allowance (δ) and the set separation distance η (η> 0). 4. The method according to claim 1, wherein the fourth step is to generate an offset surface curve (L3) at a position offset from the surface curve (L1) by the predetermined distance (E). Calculating the surface data (D3); and calculating the offset surface curve (L3) from the tool center (O2) between the tool center (O1) of the working tool (51) and the tool center (O2) of the dummy tool (52). H) moving in parallel in the Z-axis minus direction, that is, in the cutting direction of the workpiece, to calculate virtual machining protection surface data (D4) for generating a virtual machining protection surface curve (L4); The N according to claim 2 or 3, comprising a step of calculating virtual tool path data (Dt4) for generating a virtual tool path (T4) based on the data (D4) and the tool radius (r) of the working tool. Tool path generation method for C machining. 5. The pre-process surface curve (L2) by offsetting the outer peripheral edge (52a) of the tip of the chuck (52) from the pre-process surface curve (L2) by a set separation distance (η). Calculating the chuck path data (Dt6) for generating the offset path (T6) of the chuck (52) when the chuck (52) is moved in parallel so as not to interfere with the chuck; and moving the chuck along the chuck path data (Dt6). Center point (O) of the machining tool (51) in the case
1) a process of calculating virtual tool path data (Dt4) for generating a virtual tool path (T4); and a tool path data (Dt) of the post-processing surface curve (L1).
4. The method according to claim 2, further comprising the step of: (1) selecting a path data with a small machining allowance from said virtual tool path data (Dt1) and calculating tool path data (Dt5) for generating an actual tool path (T5). Or the tool path generation method for NC machining according to 4. 6. A post-processing surface curve (L1), a pre-processing surface curve (L2), shapes of a processing tool (51) and a chuck (52), a processing tool (51) in the first to fifth steps.
Tool radius (r), tool center (O1), tool path (T
1), the tool center (O2) of the pseudo tool (chuck), the tool radius (R) of the pseudo tool (52), the post-processing surface curve (L)
The tool for NC machining according to claim 1, 2, 3, 4 or 5, wherein the tool path (T1), virtual tool path (T4) and actual tool path (T5) of 1) are displayed on a screen of a display device. Route generation method. 7. A machining tool (51) for a workpiece (W).
First means (32, 33, 34) for creating post-processing surface data (D1) relating to the post-processing surface curve (L1) and storing the same in the storage means (22, 34); a processing tool (51); Second means (30, 31) for creating data relating to the type, shape and dimensions of the chuck (52) for gripping and storing the data in the storage means (22); the post-processing surface data (D1) and the processing tool ( 51) The tool path data (Dt) for generating the movement locus of the tool center (O1), that is, the tool path (T1), based on the tool radius (r) of 51).
A third means (15, 21) for calculating 1) and storing the result in the storage means (22); and an outer peripheral edge (52a) of the tip of the chuck (52) at a predetermined distance ( E), the center of the machining tool (51) when it is moved so as not to interfere with the pre-machining surface curve (L2) of the workpiece by offsetting by (O)
A fourth means (13, 21) for calculating a movement trajectory of 1), that is, virtual tool path data (Dt4) for generating a virtual tool path (T4); and a fourth means (13) for processing the post-processing surface curve (L1). The tool path data (Dt1) and the virtual tool path data (Dt
4) and the fifth means (14, 21) for selecting the tool path data having the smaller machining allowance and calculating the tool path data (Dt5) for generating the actual tool path (T5). Tool path generator for 8. The post-processing surface curve (L1), the pre-processing surface curve (L2), the shapes of the processing tool (51) and the chuck (52), the processing tool (51) in the first to fifth means.
Tool radius (r), tool center (O1), tool path (T
1), the tool center (O2) of the pseudo tool (chuck), the tool radius (R) of the pseudo tool (52), the post-processing surface curve (L)
The tool path generating device for NC machining according to claim 7, further comprising display means (16) for displaying the tool path (T1), the virtual tool path (T4), and the actual tool path (T5) of (1).