JPS62216004A - Numerically controlled working method - Google Patents

Abstract

PURPOSE:To integrate an original curved surface and its reflected image curved surface under the continuous same working conditions by means of the same NC tape, by attaining such a constitution that can process the numerical control NC data for each cutting path. CONSTITUTION:An NC tape is successively read and a curved surface A is processed by a normal NC working method until the first end-of-path EOP is detected. Here the data on a cutter path between a tool original point P0 serving as the first auxiliary path and the working start point Ps1 of the surface A is used to obtain the value Zc of a clearance plane CP formed based on the point P0, an approaching amount Dp toward the working start point in a cutting feed speed mode set when a cutter is moved down toward an axis Z and the cutting feed speed F. Then the first path number is discriminated to obtain the point Ps1 and at the same time the data on each block forming the first cutting path are stored successively in a buffer memory until the EOP is detected. Then the final position vector Pe1 of the first cutting path is calculated after the EOP is discriminated.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a numerically controlled machining method, and in particular, to improving the efficiency of mirror image machining when numerically controlling a workpiece shape having an axially symmetrical shape. The present invention also relates to a numerically controlled machining method suitable for improving machining accuracy.

[Conventional technology]

Generally, when machining a workpiece shape such as a mold using a numerically controlled machine tool, consideration should be given to the machining method, machining efficiency, and ease of creating numerical control data (hereinafter referred to as NC data) using a computer system. Divide the workpiece shape into multiple parts shapes (hereinafter referred to as curved surfaces) and perform KNC with each curved surface.
Data is generated and input to a numerical control device (hereinafter referred to as an NC device) via a recording medium such as an NC tape.

At this time, for multiple curved surfaces that are axially symmetrical to each coordinate axis of the numerically controlled machine tool and have mutually congruent shapes, the mirror image processing function of the NG machine is used, as is well known. In this case, it is sufficient to create an NC tape that processes only one of the plurality of curved surfaces.

In general, the mirror image processing function can be executed by specifying the coordinate axes whose polarity is to be reversed using a mirror image switch.For example, if the Y-axis is the axis of symmetry, If the Y-axis is the axis of symmetry, each Y-axis must be specified using a mirror image switch. Therefore, when performing NC machining of a mold or the like that has a relatively large number of symmetrical curved surfaces, by utilizing this mirror image machining function, a significant reduction in the cost of producing the NC tape can be expected.

However, as already mentioned, the conventional mirror image processing method has N
Of the coordinate value data output to the C tape, the positive and negative values are reversed with respect to the coordinate values of the coordinate axes specified by the mirror image switch, so the cutting direction, that is, the machining tool (hereinafter referred to as the blade ) is also reversed as a mirror image, resulting in a problem that the relative motion relationship between the workpiece and the cutter, that is, the processing conditions change. For example, for a curved surface A that exists in the first quadrant of the X, Y coordinate system, the cutter is moved in the direction of down cutting, which is the cutting direction that is considered to have good workability from the viewpoint of processing technology for each cutting pass. Let N
Create a C tape, instruct the Y-axis to be reversed using the mirror image switch, and perform numerical control machining (hereinafter referred to as NC machining) of curved surface B, which is a mirror image curved surface of curved surface A, with the Y-axis as the axis of symmetry. When executed, the cutting direction of each cutting pass becomes the up-cut direction, so the processing efficiency and processing accuracy in NC processing of the curved surface B will be significantly lower than in the case of a curved surface. Therefore, in such a case, although the production cost of the NC tape increases in the conventional technique, there is a problem in that it is necessary to separately produce the NC tape for the curved surface B with emphasis on workability.

Also, as a matter of course, curved surface A and curved surface B are
For example, from the viewpoint of processing technology, one curved surface A
If curved surface B and curved surface B are regarded as one curved surface and need to be integrally processed at the same time, there is also the essential problem that the mirror image processing function cannot be effectively used.

This kind of problem arises especially when the shape itself is complex, such as a large design part with a three-dimensional free-form surface, and requires high-precision NC machining.
Since the amount of tape increases significantly, an increase in the processing time of the computer system required to create NC data and an increase in the cost of creating NC tapes become major problems.

As a countermeasure to this problem, when performing the mirror image processing, in addition to performing the conventional mirror image processing, that is, as mentioned above, reversing the positive and negative of the coordinate values regarding the specified coordinate axes using a mirror image switch etc. In the case of a three-dimensional curved surface, a reverse reading method of NC data in which each cutting pass, which is usually composed of a plurality of block data, is a processing unit;
In addition, it is necessary to realize a suitable connection method between the cutting path and the cutting path read in reverse as its mirror image.

As a prior art that has been proposed to realize such a mirror image processing function, there is, for example, one described in Japanese Patent Laid-Open No. 51-79887.

This technique uses another command GO that stops the action of the command G01.
Create an NC tape so that the command GOI is applied to both the first block where the command GO1 continues to work until 2 is input, and the last block where the command GO2 comes next, so that it can be read in both forward and reverse directions. Equipped with functions and N
By creating backward interpolation information from the command data of the C tape, NC machining of symmetrical paths is realized.

Another technique is described in Japanese Patent Application Laid-Open No. 166447/1983.

In this technology, an identification code R is added to the NC data created on the magnetic tape to indicate that the symmetrical side member is to be reversed. This is to read the direction and perform reversal machining of the symmetrical member in that machining unit.

[Problem that the invention seeks to solve]

The technique described in Japanese Patent Application Laid-Open No. 51-79887 basically assumes contour machining of a two-dimensional shape, and it is necessary to specify the command G01 and the command GO2 repeatedly, and
Depending on the symmetrical machining to be performed, it is necessary to read the NC tape in the forward or reverse direction each time. few.

In addition, the essential problem is that the concept of using the cutting passes as processing units of NC machining and the problem of performing integral machining of symmetrical shapes by continuous processing between each cutting pass are not recognized. When NC data consisting of a large number of cutting path groups is required, such as for dimensional curved surfaces,
Using the NC tape for curved surface processing, it has not been possible to realize integral processing of the curved surface and its mirror image curved surface.

In addition, the technology described in Japanese Patent Application Laid-open No. 59-166447 is
Almost the same problems as the prior art described above are pointed out. In other words, the mirror image processing function is effective for reducing the amount of NC tape, which is the intention of the present invention.
When performing machining, the same NC tape is used to simultaneously and continuously process the original curved surface and its mirror image curved surface under the same machining conditions, which is important from the viewpoint of machining technology. The issue was not given sufficient consideration.

The present invention was made in order to solve the problems of the prior art described above, and it is possible to process a mirror image curved surface that is axially symmetrical to the original curved surface using an NC tape that is not used for processing the original curved surface. , a means for performing a reversal process for each cutting pass created on the NC tape, and a means for performing a suitable connection process between the cutting pass and its mirror image cutting pass, and the same NC tape. The object of this invention is to provide a numerically controlled machining method that can integrally machine an original curved surface and its mirror image curved surface simultaneously and continuously under the same machining conditions.

[Failure to solve the problem]

In order to solve the above-mentioned problems, the numerical control machining method according to the present invention transmits numerical control data for machining a part shape to be machined by a numerically controlled machine tool to a numerical control device via a recording medium. For a part whose shape is axially symmetrical with respect to each coordinate axis of the numerically controlled machine tool, the numerical control data regarding the coordinate axes specified in advance is used to reverse the positive and negative of the coordinate axes and create a mirror image. In a numerically controlled machining method in which machining is performed, each cutting consisting of a plurality of blocks in which a tool moves between both end points of the part shape in a cutting direction specified in advance at the time of creating the numerical control data among the numerical control data. For the pass data, a word representing the cutting pass number to identify each cutting pass is placed immediately before the cutting pass data, and a word indicating the end of the data for each cutting pass is placed immediately after each cutting pass data. The numerical control device reads and discriminates the pass number, calculates the position vectors of the starting point and end point of each cutting pass, temporarily stores these position vectors, and After temporarily storing the numerical control data for each block, the numerical control data for each block is read out in the forward or reverse direction to perform mirror image machining, and the data for connecting each cutting pass in the big feed direction is read out in the forward or reverse direction. By automatically generating numerical control data related to auxiliary tool movement, for each cutting pass, the cutting pass and a cutting pass that is a mirror image of the cutting pass with respect to the specified coordinate axis are continuously machined. This is the method I used to do it.

The concept behind the development of the present invention and the definitions of terms used in its technical means will be explained next.

When performing NC processing on curved surfaces A and B that are axially symmetrical to each other, the production cost of NC tape can be reduced, and the NC
In order to reduce the amount of tape, for example, an NCC tape is created for processing a curved surface, and for curved surface B, a mirror image processing function is often used as is well known. As a matter of course.

It has been created to provide optimal processing conditions in consideration of NCC tape processing efficiency, etc. Therefore, it is only necessary to realize a numerically controlled machining method that provides the same machining conditions as when machining the mirror image of the curved surface B and when machining the curved surface A.

To do this, first of all, use only the NC data output on the NCC tape, and first create a separate NCC tape with the cutting direction reversed with respect to curved surface A, and then print it on the NCC tape. The object of the present invention is to realize an NC machining method equivalent to that of performing the NC machining of the curved surface B by performing mirror image machining using the curved surface B.

Second, it is possible to integrally process curved surfaces A and B at the same time as necessary.
The object of the present invention is to consider a curved surface C that is a composite of the curved surface C, create an NC tape C for processing this curved surface C, and realize an equivalent NC processing method.

By the way, among the NC data output to the NC tape, if we focus on the block data that includes the cutter path, that is, the dimension word that is directly involved in the movement of the cutter or workpiece, it can be roughly divided into three types: auxiliary path, cutting path, and pick feed path. It can be classified into different types of cuttapaths.

In both cases, NC is generally composed of multiple blocks.
data, and the contents of each can be defined as follows.

First, auxiliary paths are auxiliary paths that are not directly involved in curved surface machining, such as a cutter path from the tool origin to the start point of machining a curved surface, or a cutter path that returns to the tool origin from the end point of machining after completing curved surface machining. It refers to cuttapass.

In addition, a cutting path is defined as a cutter moving on a curved surface between both end points of the curved surface in a cutting direction specified in advance when creating the NC data. This is a so-called cutter path group in the feed direction, and is the main NC data directly related to curved surface machining.

Furthermore, the pick feed path refers to a so-called cutter path in the pick feed direction for connecting the respective cutting passes described above according to processing conditions.

The basic idea of the present invention is to focus on the above-mentioned points, and to calculate N
As a configuration that can process C data.

The above-mentioned auxiliary path and pick feed path can be newly generated according to the data of the cutting path, and when performing mirror image machining, in addition to reversing the sign of the designated coordinate axes, the cutting path of the NC data and its mirror image are The above objective is achieved by realizing an effective connection system between these cutting passes so that the cutting passes can be continuously NC-machined.

First, a curved surface A is prepared on an NCC tape for processing using a known method similar to the prior art. At that time, in the present invention, a new identification word is added to each of the cutting passes as a word for identifying each of these cutting passes. For example, a series of cutting pass numbers (hereinafter referred to as pass numbers) are added to the beginning of each cutting pass, and at the end a word indicating the end of the cutting pass, that is, an end op pass (
(hereinafter referred to as EOP) is added on the NCC tape.

These pass numbers and EOPs do not need to be particularly limited as long as they can be identified by the NC device. For example, the word of the pass number is L na a (n n is a number).
, and define the word of EOP as P.

In general, in the case of curved surface machining, the cutting path is composed of a large number of blocks, but from the standpoint of the present invention, the starting and ending points of these cutting passes must be at both ends of the machining area of the curved surface in the cutting direction. Therefore, even when creating an NC tape using a computer with 7 stems, the pass number and EOP can be easily added to the beginning and end of each cutting pass.

Input the NC tape A created in this way into the NO device, and specify the coordinate inversion axis for processing the mirror image curved surface B for the curved surface A, as in the well-known mirror image processing. Curved surfaces A and B are integrally processed as described.

[Effect]

Next, the procedure of the mirror image processing method of the present invention will be explained according to the idea that developed the present invention.

The symbols used in this description are the same as those in FIGS. 6 to 9, which will be referred to in the description of the embodiments described later.

The NCC chips are read one after another, and the curved surface A is processed by normal NC processing until the first EOP is detected. that time.

In the present invention, the tool origin P is the first auxiliary pass.

Using the data of the cutter path from to the machining start point P, l of the curved surface A, calculate the value Z of the clearance brain (hereinafter referred to as CP) based on Po and the cutting feed system when lowering the cutter in the Z-axis direction. The approach distance to the machining start point in speed mode and the cutting feed speed F are determined in advance. Although these values can be easily calculated, they may also be specified in advance by manual data input (hereinafter referred to as MDI), for example. Further, the first pass number, for example Loo 1, is determined, and the position vector P of the starting point of the first cutting pass is determined, ! At the same time, the data of each block constituting the first cutting pass is stored in a newly provided buffer memory until the EOP is detected, and once the EOP is determined, the end point of the first cutting pass is determined. The position vector P, , is calculated in advance.

Thereafter, using the coordinate axes specified in advance by a mirror image switch, MDI, etc. from the backup memory, both the X and Y coordinate values are reversed in the forward direction, and the coordinate values of either one are reversed in the forward direction. reads the data of each block sequentially in the opposite direction, and then, similar to known mirror image processing, reverses the sign of the specified coordinate values and performs NC processing to create a cutting pass that is a mirror image of the first cutting pass. I will do it.

In this way, once the mirror image machining of the first cutting pass is completed, the pick feed pass data output to the NC tape A up to the first pass number is skipped because it is unnecessary in the present invention. The path number LOO2 is determined and the position vector Ps2 of the starting point of the second cutting pass is calculated. Then, the mirror image processing end point Q-1 (P-+ or P,
A new big feed path is generated from point (which is a mirror image of l) to P,2. This pick feed path, for example, first ascends from Q, l to CP in two axial directions, then C
3 blocks of data in rapid traverse mode in which the machine moves on P to P, 2, and from that point, the quadratic value of P, 2 approaches the two-axis direction and descends to the point where it is larger, and then the cutting feed system. It is sufficient to generate data for a total of 4 blocks, including a block that descends in the Z-axis direction by DI+ up to P and 2 at a speed.

After completing the big feed processing in this way, normal NC machining is performed until the first EOP is detected, as in the case of the first cutting pass, and each The data of the block is stored in the buffer memory, the position vector P,2 of the end point is obtained, and the mirror image processing of the second cutting pass is performed.

In the same way, the mirror image processing described above is repeated for all the cutting passes, and once the mirror image processing of the last cutting pass is completed, the auxiliary pass that is output on the NC tape AK is skipped, and a new K An auxiliary path is generated to return to the tool origin Po from the end point Q, , of the mirror image machining. These auxiliary passes are all in fast forward mode, for example, first a block ascends from Qea to CP in the Z-axis direction, then a block rises above CP to P.
It is sufficient to generate data for two blocks of the block to be moved to o.

In this way, using only NC tape A, curved surface A
It is possible to realize integral processing of the curved surface B and its mirror image curved surface B.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 12.

FIG. 1 is a block diagram showing the overall node configuration for carrying out a numerically controlled machining method according to an embodiment of the present invention.

Numerical control data (hereinafter referred to as NC data) for processing a part shape created on the NC tape 10, for example, curved surface A, is input to the data processing unit 20 of a numerical control device (hereinafter referred to as NC device). .

In the data processing section 20, first, a data reading processing section 30 sequentially reads one block at a time, decoding it with a decoder, and passing it to a mirror image processing section 40.

The mirror image processing section 40 performs mirror image processing for performing the integrated processing of the present invention, which will be described later, under microprocessor control, and sequentially delivers each cutter pass data to the register storage processing section 50. In this register storage processing section 50,
Using a well-known method, numerical information such as the amount of tool movement for each coordinate axis is stored in a predetermined command value register, and then converted into a pulse train corresponding to the amount of tool movement in an interpolation circuit 60. - Analog conversion is performed to create a numerically controlled machine tool (hereinafter referred to as an NC machine tool) 8.
The configuration is such that it drives 0.

Note that the command for mirror image processing can be issued using a mirror image switch as is well known, but in this embodiment, for example, manual data input (hereinafter referred to as MDI) is used.
11, it is possible to specify the inversion coordinate axis and its sequence in the case of multiple mirror image processing, as will be described later. In addition, constants such as a value of 2 degrees for a busy clearance plane (hereinafter referred to as CP) to generate a big feed path, an approach amount Dpb to a machining start point, a cutting feed rate F, etc. may also be specified in the MDI.

Next, FIG. 2 is a block diagram for explaining the functions of the mirror image processing section 40 of FIG. 1, FIG. 3 is a flowchart showing the mirror image processing procedure of this embodiment, and FIG. N.C.
FIG. 2 is an explanatory diagram showing the structure of NC data inputted by C.

Further, FIG. 5 is an explanatory diagram showing the data format of the cutting path in this embodiment.

The data format of each cutting pass is, for example, as shown in FIG. The coordinate value of the starting point of the cutting pass is shown, followed by the data of the block included in this cutting pass, and finally (immediately after the cutting pass data), it ends with the EOP word P indicating the end of the data of the cutting pass. It is composed of Here, ・ is the end op block (hereinafter referred to as EOB)
). Note that since the coordinate values of the starting point are determined from each block data, they do not necessarily need to be output. Further, the final cutting pass is made to be distinguishable from other cutting passes by, for example, having two consecutive EOPs.

Figures 6 to 8 show the data of each block that constitutes the auxiliary pass and the big feed pass for connecting each cutting pass. Figure 6 shows data from the tool origin to the machining start point. FIG. 7 is an explanatory diagram showing an example of how to generate an auxiliary path, FIG. 7 is a big feed path, and FIG. 8 is an auxiliary path that returns to the tool origin after machining one curved surface.

Moreover, FIG. 9 is a functional explanatory diagram showing an example of application of the mirror image processing method according to an embodiment of the present invention. : This shows an example of integrally processing a mirror image curved surface B whose Y coordinate value is reversed (axis of symmetry x).

For the application example shown in FIG. 9, the detailed processing procedure of the numerically controlled machining method according to this embodiment will be explained with reference to FIGS. 4 to 9 while comparing the block diagram of FIG. 2 and the flowchart of FIG. 3. and explain.

First, in step 4 of the initialization process shown in FIG. 2, an execution command for mirror image processing is specified in advance.

For example, in the example shown in Fig. 9, the inversion axis is the Y axis, that is, MD.
The data designated as Y by I, etc. is imported, and initialization processing such as setting of the auxiliary pass mode, which is the first cutter pass mode, is performed (step 2 in FIG. 3).

Then, in the determination process 42, the data of each block is sequentially read + (procedure ①) 1 determination is made, and depending on the contents, the process branches to each processing system as shown in the flowchart of FIG.

First, until the first pass number is detected, as shown in FIG. 6, from the tool origin Po to the starting point P of the first cutting pass 100,
Since this is an auxiliary path up to l, the data of each block is sequentially transferred to the register in the same way as the well-known NC machining process (this transfer process is all the same, so the following explanation will be omitted). However, in this embodiment, in the position vector calculation process 43, the position vector of the cutter at each processing time point is calculated (procedure ■), and the CP value Z required for the pick feed path generation process, etc., which will be described later, is calculated. . , approach weight to the machining start point, %, and cutting feed rate F are determined in advance. These numerical values can be easily calculated from the tool position vectors P sl HP dl and P, l of each block constituting the auxiliary path, as shown in FIG.

If the first pass number is detected in the determination process 42, the head mode indicating that it is the beginning of the cutting pass is set, and the first pass flag indicating that it is the first cutting pass 100 is set.

In the flowchart of FIG. 3, set is indicated by ■, and end is indicated by ■.

In this way, the input data after the first block is the data of the blocks forming the first cutting pass until the EOP is detected, so in the case of the head mode, that is, the first block, the input data is the data during the cutting pass. Convert to a path mode indicating that
, set the starting points P and l of this cutting path (step ■
), and in the case of the first cutting pass, it is not necessary to generate a pick feed pass, so the process moves on to reading the next block.

On the other hand, in the case of data other than the head mode, that is, in the case of the pass mode, in the NC data storage process 45, the data is sequentially stored in the buffer memory (step 2).

If EOP is detected in the 1 discrimination process 42 in this way, the NC machining from the starting point P81 to the ending points P and l of the first cutting pass 100 of the curved surface A shown in FIG. 9 will be executed, so the following The input data is converted into a big mode indicating that it is a big feed path, and at the same time, the end point P, 1 of this cutting path is stored in the position vector storage process 44.
is set (procedure ■), and then a mirror image cutting process (hereinafter referred to as mirror process) is performed on the first cutting pass 200 of the curved surface B shown in FIG. 9 (procedure ■).

This mirror processing is performed as follows.

As already mentioned, since the NC data of each block from P, 1 to Pal, which constitutes the first cutting pass 100 of the curved surface A shown in FIG. 9, is stored in the buffer memory, N
In the C data reading process 46, the data of each block is sequentially read from the buffer memory in the reverse direction, and by reversing the sign of the Y coordinate value, which is the inversion coordinate axis in this case, the first cutting pass 200 on the curved surface B is obtained. For that, the starting point is P, l
, NC machining can be performed with the end point at Q-+. As a result, from J+ to Q sl, a cutting path 300 that is a composite of the original first cutting pass 100 and the mirror-processed first cutting pass 200 (hereinafter referred to as a composite first cutting pass), curved surface A, and curved surface This is equivalent to processing B in one piece. In this way, when the mirror processing of the first cutting pass is completed, the position vectors Q and l of the tool at that time are reset.

The input data after the next block is the first cutting pass 100.
The end point of Pa! from the starting point P1 of the second cutting pass 101. However, in this embodiment, the big feed path up to this point is skipped as unused data in the determination process 42.

If the next number is detected in the 1 discrimination process 42, the head mode is set in the same manner as described above. In this case, until the first EOP is detected, the second cutting pass is 10.
1, so in the case of the head mode, convert to the pass mode and set the starting point P and 2 in the same way as in the case of the first cutting pass, and then in the case of the second cutting pass and onwards, , a big feed path from the position vector Qe at the time of completion of the mirror processing to the starting point P, 2 of the second cutting path is generated by the method described later (step 1).
). Further, the data of each block in the subsequent pass modes are sequentially stored in the buffer memory K as in the case of the first cutting pass.

In this way, the second cutting pass 101 on the curved surface A
, the second cutting pass 201° on the curved surface B, the final cutting pass 110 on the curved surface A, and the final cutting pass 210 on the curved surface B are repeatedly executed to realize integrated machining of the curved surfaces A and B. can.

After completing the mirror processing of the last cutting pass, it is necessary to generate an auxiliary path for returning to the origin from the tool position vector Q at that point to the tool origin Po.
When the EOP of the last cutting pass is detected in the determination process 42, an end flag is set as the determination flag, and the block data mode is pick mode and the end flag is set. In this case, you can use the method described later to generate an auxiliary path to return to the tool origin (step ①) and skip the input auxiliary path data as unnecessary data.

Next, a method for generating the auxiliary path for returning to the tool origin in the NC data automatic generation process 47 and the aforementioned big feed path will be explained.

First, an example of a big feed path will be explained with reference to FIG.

cp in the Z direction from the end point Q, l of the composite first cutting pass 300
Point Q above. ! The data of the block descends in the Z direction to a point Pg where Qel is larger by the broach amount Dp, and the cutting feed speed is changed to F---→ p, F) , 1, and the second synthetic cut-
111111 inch cutting pass 3゛01 starting point P, 2 with PmlPg2 up to 2
We will generate block data.

Here, this PI! For the last block moving from P,2, the two coordinate axes Z m 1 of P,1 and P,2
(7) Compare with Z coordinate axis Zm2, Z ml ) Z
If it's 12.

First, on the XY plane, the Z coordinate axis is (ZLx
Z-2) and then lower it to PN2. Conversely, when Z-1<Z, 2, first move from P, l in the Z direction (Z-2Z-t) (7
) distance, then move to PN2 on the XY plane, and further divide the data into two blocks to avoid unreasonable cutting on curved surfaces and improve machining accuracy. .

In addition, here, considering the processing conditions, the cutter is set to P once.
, 1 and then further move to P, 2 has been described, but of course it is also possible to create a pick feed path that directly moves from Q, l to J2 in a similar manner.

Next, the auxiliary pass to return to the tool origin Po is performed from the end point Q, , to Z of the one composite final cutting pass 310, as shown in FIG.
It is sufficient to generate two blocks of data for the fast-forward mode shown by the dashed line Q-Po on cp.

According to this embodiment, the N of the NC tape A for machining the part shape to be processed by the NC machine tool, for example, the curved surface A, is
By adding a new word representing the pass number and EOP to the C data, we have made it possible to process the NC data in units of cutting passes, so we can process the curved surface A and its mirror image curved surface B using the same NC tape. It is possible to realize a numerically controlled machining method that allows simultaneous and continuous integral machining under the same machining conditions. As a result, the mirror image machining function, which was previously not used in NC machining that requires high precision due to reduced machining efficiency, can be effectively utilized, so the time required to create NC tapes is reduced. and costs can be significantly reduced.

Next, another embodiment of the mirror image processing function will be described with reference to FIGS. 10 to 12.

10 to 12 are functional explanatory diagrams showing other application examples of the mirror image processing method according to the embodiment of the present invention.

FIG. 10 shows curved surfaces A, B, and C using the NC tape for processing curved surface A explained in FIG.

An example of integrally processing four curved surfaces of D is shown.

In this case, the execution command for mirror image processing is Y, XY.

This can be executed by specifying the order of X. That is,
The mirror processing described in the example of FIG. 9 may be repeated three times.

For the curved surface B, in the NO data readout process 46, each cutting pass data is read out from the buffer memory in the opposite direction as described above, the sign of the X coordinate value is reversed, and mirror processing is performed.

Further, for the five curved surfaces CK, each cutting pass data is read out from the buffer memory in the forward direction, and mirror processing is performed by reversing the sign of the X and X coordinate values.

Furthermore, for curved surfaces, each cutting pass data is read out from the buffer memory in the opposite direction, and mirror processing is performed by reversing the sign of the X coordinate value.

According to the example shown in FIG. 10, an NC tape for processing curved surface A is used to process curved surface A and its mirror image curved surface B.

C and D can be integrally processed continuously under the same processing conditions.

In the embodiment shown in FIG. 9, an example was shown in which the mirror image machining execution command was specified as Y, but if X is specified as another example, the cutting path 12 of the input data is
0 and the cutting path 220 which is its mirror image will be separated.

In FIG. 11, the cutting path 120 has a starting point P I 1
The r end point is P21, and the mirror image cutting path 220 has a curved surface with a starting point of P4□ and an ending point of Pal.

In such a case, in this embodiment, when performing mirror processing, the first point read from the buffer memory, that is, the starting point P41 of the mirror image cutting path 220, is compared with the immediately preceding cutter position vector pzt, and the same point is determined. If so, execute NC machining continuously on both pre-cutting passes as already mentioned, and if there are different points, generate a big feed pass from Pal to P41 in the same manner as the above method, and then create the mirror image cutting pass 220. NC machining will be performed. .

Further, FIG. 12 shows an example in which XY is specified as a mirror image machining command, and the cutting path 120 is similar to that in FIG. 11.
First escape r s r End Kuntsuri, 1, #! , image cutting pass 2
30 is a curved surface whose starting point is P 31 *end point is P41. In this case as well, after generating a big feed path from the end point P21 of the input data cutting path 120 to the starting point p3t of the mirror image cutting path 230, the NC machining of the mirror image cutting path 230 is executed.

According to the example of FIG. 11.12, by automatically generating NC data of a big feed pass between the cutting pass 120 and its mirror image cutting passes 220 and 230, the NC tape for processing the cutting pass 120 is Using this, the cutting pass 120 and its mirror image cutting passes 220 and 230 can be continuously and integrally machined under the same processing conditions.

〔Effect of the invention〕

As explained above, according to the present invention, when processing a mirror image curved surface that is axially symmetrical to the original curved surface using an NC tape for processing the original curved surface, each of the A means capable of performing reversal processing in units of cutting passes, and a means capable of performing suitable connection processing between the cutting pass and its mirror image cutting pass are realized, and the original curved surface and its mirror image curved surface are cut using the same NC tape. It is possible to provide a numerically controlled machining method that can simultaneously and continuously perform integral machining under the same machining conditions.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the overall node configuration for performing a numerically controlled machining method according to an embodiment of the present invention, and FIG. 2 explains the function of the mirror image processing section in FIG. 1. FIG. 3 is a flowchart showing the mirror image processing procedure of this embodiment. FIG. 4 is an explanatory diagram showing the structure of NC data manually input from the NC tape. An explanatory diagram showing the data format of an example cutting path, Fig. 6 is an explanatory diagram showing the method of generating the auxiliary path from the tool origin to the machining start point, and Fig. 7 is an explanatory diagram showing the method of generating the big feed path. , FIG. 8 is an explanatory diagram showing a method of generating an auxiliary path for returning from the machining end point to the tool origin, and FIG. 9 is a functional explanatory diagram showing an example of application of the mirror image machining method according to an embodiment of the present invention. 10 to 12 are functional explanatory diagrams showing other application examples of the mirror image processing method according to one embodiment of the present invention. 10... NC tape, 20... data processing section, 30
...data reading processing section, 40...mirror image processing section,
41...Initialization processing, 42...Discrimination processing, 43...
・Position vector calculation processing, 44...Position vector storage processing, 45...NC data storage processing, 46...NC
Data reading process, 47... NC data automatic generation process, 50... Register storage processing section, 80... NC machine tool, 100.200... First cutting pass, 101, 2
01...Second cutting pass, 110,210...Final cutting pass, 120...Cutting pass, 220,230...
・Mirror image cutting pass, 300...Synthetic first cutting pass, 30
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Claims (1)

[Claims] 1. Input numerical control data for machining the part shape to be machined by the numerically controlled machine tool into the numerical control device via a recording medium, and check whether the part shape is aligned with each coordinate axis of the numerically controlled machine tool. In a numerical control machining method that performs mirror image machining by reversing the positive and negative of the coordinate axes using numerical control data related to prespecified coordinate axes for a part having an axially symmetrical part shape, , for each cutting pass data consisting of a plurality of blocks in which the tool moves between both end points of the part shape in the cutting direction specified in advance when creating the numerical control data, identify each cutting pass immediately before these cutting pass data. Immediately after each cutting pass data, a word indicating the cutting pass number for each cutting pass is added, and a word indicating the end of the data for each cutting pass is added, and the numerical control device reads and discriminates the pass number. , calculate the position vectors of the start point and end point of each of the cutting passes, temporarily store those position vectors, and temporarily store the numerical control data of each block constituting each of the cutting passes, and then calculate the position vectors of the start and end points of each of the blocks. By reading numerical control data in the forward or reverse direction to perform mirror image machining, and by automatically generating numerical control data regarding auxiliary tool movement in the big feed direction to connect each cutting pass, A numerically controlled machining method characterized in that, for each of the cutting passes, the cutting pass and a cutting pass that is a mirror image of the cutting pass with respect to a designated coordinate axis are sequentially processed.