JPH04289056A - Generation of processing program in cad/cam device - Google Patents

Abstract

PURPOSE:To obviate the partial correction of NC data after formation of an NC processing program as required in conventional CAD/CAM devices if processing elements without tool diameter compensation such as slit-like cut processing elements are included in processing elements for forming processing shapes of subject materials, and generate NC processing data for both of a process of compensating tool diameters automatically and a process without performing it. CONSTITUTION:NC processing data are automatically generated for generating an NC processing program to define processing elements for forming processing shapes of subject materials in a drawing display image of a CAD/CAM device, designate slit-like processing elements, and define reciprocatory processing ways to display a reciprocatory process symbol, so a tool compensation quantity is zero on the symbolized reciprocatory processing way, while the tool compensation quantity is at a designated value on the processing way for the other processing elements.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention applies to CAD/CAM (Com
puter aided design /Compu
ter aided manufa-cturing
) The present invention relates to a method for generating an NC (numerical control) machining program in an apparatus, particularly a method for generating an NC machining program including a slit-like machining element.

0002

2. Description of the Related Art First, normal offset machining in NC (numerical control) machining will be explained. FIG. 8 is a diagram showing an example of a graphic display screen of a conventional CAD/CAM device. In the figure, the shape formed by the shape elements 100, 101,...106 is the desired processed shape, and the point 107
and 108 represent a machining start point and a machining end point, respectively. In addition, the forming path formed by the broken line segments 109 to 117 is the machining path of the tool offset from the desired machining shape, and is determined by a predetermined offset amount from the machining shape (for example, in the case of wire-cut electric discharge machining, the wire electrode radius and the discharge gap The trajectories are separated by the sum of the amounts. Therefore, 109 to 117 are also called machining trajectories. Also point 1
20 to 125 indicate intersection points on each offset machining locus.

FIG. 9 is a diagram showing an example of a machining program for the NC machining of FIG. 8, which is developed into NC machining data of blocks 130 to 141 based on the shape data of FIG. In the figure, 130 is a block for setting an offset amount, 131 is a block for setting a coordinate system, and 132 is a block for setting an offset amount.
133-139 are the offset starting blocks which head toward the first shape 100 from the machining start point 107 and start offset machining of the set offset amount, and 133-139 are machining paths 100-106.
This is a machining trajectory block along the .

FIG. 10 is a diagram illustrating offset machining in the NC machining of FIG. 8. (a) in the same figure shows the offset amount and offset machining path, and (b) in the same figure shows the workpiece after machining. It shows the shape of. In FIG. 10, H
1 is an offset amount, and in the case of wire cut electric discharge machining, it is the sum of the wire electrode radius and the discharge gap amount. The shape formed by the shape elements 101 to 105 is the processed shape, 121 is the intersection of offset paths 111 and 112, 122 is the intersection of offset paths 112 and 113, 12
3 and 124 are also the intersection of the offset paths, 150
indicates the desired shape.

FIG. 11 is a diagram explaining slit-like cutting in conventional NC machining, in which (a) shows the offset amount and machining path, and (b) in the same figure shows the workpiece after machining. It shows the shape of things. In FIG. 11, the shape formed by shape elements 160 to 163 is the desired machining shape, and line segments 164 and 166 are offset machining paths,
H1 indicates the amount of offset, 167 and 168 each indicate the fulcrum of the offset machining path, and 169 indicates the desired shape.

FIG. 12 is a diagram showing an example of a machining shape display screen of a conventional CAD/CAM device. In the figure, the shape formed by shape elements 3, 4, to 11 is the desired processing shape, and among these, 5, 7, and 9 are elements for performing slit-like cutting processing. Here, 1 is the machining start point when machining the above-mentioned machining shape, and 2 is the machining end point. In addition, 170 is a partial enlarged view of one slit shape, and 171 to 173 are for performing slit-like cutting processing.
This is a shape element that shows the shape after the slit shape is divided into three straight lines and corrected.

FIG. 13 is a flowchart showing the processing procedure when performing conventional slit-like cutting, and FIG.
FIG. 3 is a diagram showing an example of an NC machining program for machining a slit-like cutting element.

The operation of offset machining in the case of wire cut electrical discharge machining will be explained with reference to FIGS. 8 to 10. In order to machine the desired machining shape made up of the shape elements 100 to 106 in FIG. It won't happen. For this reason, first, the offset amount H1 is set in the offset amount setting block 130 of FIG. Next, coordinate system setting block 13
After setting the coordinate system of the machining start point 107 in step 1, in the offset start block 132, machining is started from the machining start point 107 along the machining path 109, and the shape element 100 is
The machining data is set so that the offset amount of H1 is obtained at the edge of . In the machining data set after the next block 132, first, machining trajectories 110 and 111 that are separated by offset H1 from shape elements 100 and 101 are calculated, and machining path 1
Advance the wire along 10. Thereafter, in the same way, trajectories that are separated by the offset amount from each shape element are determined, and machining trajectories that are machined up to each of these intersection points are sequentially determined. After machining up to the terminal element 106 of the shape element, the machining trajectory 117 becomes such that the offset gradually cancels toward the machining end point 108. In the NC machining program of FIG. 9, block 140 is an offset cancel block. When the machining end point 108 is reached, the machining ends at block 141. If the wire electrode passes through the machining trajectories 111 to 115, the desired shape 150 shown in FIG. 10(b) is finally obtained.

Next, offset processing when machining a slit-like cutting element will be explained with reference to FIGS. 11 to 14. In the slit-like cutting element 161 or 162 shown in FIG. 11(a), tool diameter correction is usually not performed in order to narrow the groove width of the slit. For this reason, it is necessary to set the offset amount to zero and find machining trajectories that are separated by the offset amount H1 for other machining elements. Figure 1
1, 167 is an offset machining path 164 that is away from the shape element 160 by an offset amount H1, and a shape element 161.
This is the intersection point with the offset machining path, that is, the extension line of 161, which is separated by an offset amount of zero from . Further, 168 is the connection point between the shape elements 161 and 162, and can also be said to be the intersection of offset trajectories where the offset amount is zero. In the case of wire-cut electrical discharge machining, the wire electrode is placed in the offset machining path 164.
and 165 and reach point 168, the machining direction is changed by 180° and the same offset machining path 165 is returned. Then, it moves from the intersection 167 to an offset machining path 166 and moves on this machining path 166. If slit-shaped cutting is performed without performing tool diameter correction in this way, a slit-shaped groove with a groove width equal to the wire electrode radius + discharge gap amount will be machined, as shown in Fig. 11(b). It can be made into a thing.

Next, a procedure for creating NC machining data for performing the slit-like cutting process in the CAD/CAM device will be explained with reference to FIGS. 12 to 14. Conventionally, in order to create machining data in a CAD/CAM device, first, in step S180 in FIG.
Each shape element 3 to 11 forming the desired processed shape as shown in 2 is input into the CAD/CAM device by data input operation using a tablet, stylus pen, etc., and defined on the graphic display screen of the display device. .

Next, in step S181 of FIG.
Partially enlarged view 1 of the slit-like cutting element 5 shown in FIG.
Disassemble and correct into three straight lines 171 to 173 like 70. In this step S181, when automatically determining the machining path in the CAD/CAM device, continuous machining elements are sequentially traced, so the reciprocating element is divided into three as described above and the elements are continuous. This is because there is a need to correct this. In step S182, it is determined whether the division correction of all the slit-like cutting elements has been completed, and if NO, the process returns to step S181 and repeats this until the division correction is completed. If YES is determined in step S182, machining attributes such as machining start point 1 and machining end point 2 are specified in step S183. When the continuous processing of the machining path is completed in this way, step S1
In step 84, NC machining data is created.

Thereafter, in step S185, machining paths 171 to 173 are created by dividing the slit-like cutting element into three parts.
Data blocks on the NC processing data corresponding to etc., that is, data blocks 190-192 and 1 shown in FIG.
93, etc., using the NC data editing function, so that the offset amount becomes zero. Therefore, in the data blocks 190 and 193, zero is substituted for the offset amount H1. That is, it is necessary to set the offset amount to 0 in the portion where the processing elements 171 to 173 are processed, and set the normal offset amount to the other processing elements. However, once the offset amount is commanded, the value is held until the next change, so the offset amount is set to zero in the NC data for machining the machining element 171, and the slit-shaped machining path 1
In the machining shape 6 following 73, in order to return to the normal offset amount, H1 is set in the NC data block 47 of the machining shape 6.
A normal correction amount of =H50 is set. After correcting the NC data as described above, the desired slit-like cutting process can be performed by inputting the NC data into the NC machine tool and executing it.

[0013]

[Problem to be Solved by the Invention] However, in the method of generating a machining program in a CAD/CAM device as described above, in order to perform slit-like cutting machining without conventional tool diameter correction, as described above, Since it is necessary to modify the slit-like cutting elements by dividing them into three elements, it is necessary to partially correct the NC data after creating the NC machining program, making the work of creating NC data for slit-like cutting very complicated. There was a problem. Also NC
There is a possibility that a correction error may occur during the work of correcting the machining data, and the created NC machining data must be thoroughly checked, resulting in problems such as a decrease in the efficiency of creating the machining program.

The present invention has been made in order to solve the above-mentioned problems, and the present invention has been made in order to solve the above-mentioned problems. Even if machining elements that do not exist are included, there is no need to partially correct the NC data after creating an NC machining program on a CAD/CAM device as in the past, and it is possible to perform both machining with and without automatic tool diameter compensation. N of
The object of the present invention is to obtain a method for generating a machining program in a CAD/CAM device that can generate C machining data.

[0015]

[Means for solving the problems] CAD/C according to the present invention
The machining program generation method in the AM device is to create each machining element that forms the machining shape of the workpiece using CAD or CAM.
A means for defining on a graphic display screen in the device, and when the processing element includes a slit-like cutting processing element,
means for specifying the slit-like cutting element and defining its reciprocating machining path on the graphic display screen; Based on means for displaying a machining symbol and each machining element forming the defined machining shape,
Automatically generate sequential numerical control machining data so that the tool compensation amount becomes zero on the reciprocating machining path of the slit-shaped cutting element and the tool compensation amount becomes a specified value on the machining path of other machining elements. The system is equipped with means for generating a numerically controlled machining program.

[0016]

[Operation] In the present invention, each machining element forming the machining shape of the workpiece is defined on the graphic display screen of a CAD or CAM device, and when the machining element includes a slit-like cutting machining element, , specifying the slit-shaped machining element and defining its reciprocating machining path on the graphical display;
displaying a reciprocating machining symbol near the reciprocating machining path of the defined slit-like cutting machining element on the graphic display screen;
Based on each machining element that forms the defined machining shape, the tool compensation amount is zero on the reciprocating machining path of the slit-shaped cutting machining element, and the tool compensation amount is specified on the machining path of other machining elements. A numerically controlled machining program is generated by automatically generating numerically controlled machining data sequentially so as to obtain a value.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram showing an example of a machining shape display screen of a CAD/CAM apparatus according to the present invention, and shows the display state after a slit-like incision machining element is defined. Further, FIG. 2 is a diagram showing an example of a machining shape display screen before defining the slit-like cutting machining element of FIG. 1. In FIGS. 1 and 2, 1
2 is a machining start point, 2 is a machining end point, and 3 to 11 are shape elements constituting the machining shape, including slit-like cutting elements 5, 7, and 9. 12, 13, and 14 are reciprocating machining symbols indicating slit-like cutting elements.

FIG. 3 is an explanatory diagram showing a machining trajectory including the slit-like cutting process shown in FIG. In the same figure, 20~
22, 25, 28, and 31 to 33 indicate machining paths including offsets. However, slit-shaped machining paths 23 and 24, 26 and 27, and 29 and 30 overlap with slit-shaped paths 5, 7, and 9, respectively, and are on the same straight line. In FIG. 3, the forward machining path 23 and the backward machining path 24 are intentionally shifted to make them easier to understand. The same applies to 26 and 27 and 29 and 30.

00
19] FIG. 4 is a diagram showing an example of an NC program automatically generated by the CAD/CAM device according to the present invention. In the figure, 40 is an offset amount setting block;
1 is a coordinate system setting block, 42 is an offset starting block, 43 to 51 are machining trajectory blocks for machining machining shapes 3 to 11, 52 is an offset cancel block, 5
3 each represents a program end block.

FIG. 5 is a block diagram showing the configuration of a CAD/CAM device according to the present invention. In the figure, 60 is a graphic display device for displaying the processed shape, and an enlarged example of the display screen is shown above. 61 is a ROM (read only memory) in which programs for executing various functions are stored; 62 is a RAM (random access memory) in which machining shape data displayed on the graphic display device 60 is stored; 63; controls the entire CAD/CAM device. A CPU (central processing unit, such as a microprocessor), and 64 a keyboard for inputting numerical data and the like. Further, 65 is a tablet for selecting various processing menus and inputting data, and 66 is a stylus pen used for instructing the processing menu 67 on the tablet 65.

FIG. 6 is a flow chart showing the definition procedure of slit-like cutting according to the present invention, and FIG.
It is a detailed flow chart of processing data generation procedure.

1 to 5 according to the flowcharts in FIGS. 6 and 7.
A method for generating a machining program including slit-like cutting according to the present invention will be explained with reference to . Step S70 in FIG.
First, as in the conventional example, a processed shape as shown in FIG. 2 is defined on the display screen of the graphic display device 60 using the tablet 65 and stylus pen 66.

Next, in step S71 of FIG. 6, the slit-like cutting menu is selected from the machining menu 67 on the tablet 65, and element 5, which is reciprocating machining, is displayed on the graphic display device 60 using the stylus pen 66. instructions on the display screen. Specifically, the CPU 63 reads the position data of the X and Y coordinates specified by the stylus pen 66 from the tablet 65, and based on this read data, the RO
The designated position is displayed on the display screen of the graphic display device 60 using the display program stored in M61. After specifying this reciprocating machining element, step S72
In the CPU 63, the reciprocating machining element 5 on the display screen
A reciprocating machining symbol 12 is displayed near . Specifically, the CPU 63 stores reciprocating symbol data in the RAM 62, reads out this stored data, and displays it on the graphic display device 6.
Display by 0. All of the following operations are also performed under the control of the CPU 63, but since the operations of each device are almost the same, the explanation will be omitted.

In step S73 of FIG. 6, it is determined whether the designation of the round trip route elements has been completed, and if the designation has not been completed yet, the process returns to step S71. In this example, similar to slit shape 5, reciprocating processing is similarly designated for other slit shapes 7 and 9. When all of the above processing specifications are completed, the determination result in step S73 is YES.
Therefore, in the next step S74, machining attributes are specified, that is, machining start point 1 and machining end point 2 are defined. Then, in step S75, the step S7
Based on the machining specifications in steps 0 to S74, NC machining data having a correct offset amount is created even when slit-like cutting machining is included.

The detailed procedure of this NC machining data generation process will now be explained with reference to the flowchart of FIG. First, in step S80, from the machining start point 1 to the first machining shape element 3
The NC data block of the machining route up to this point, that is, the approach route, is output. This data block sets an offset start command and offset data. In step S81, a continuous shape element connected to the first shape element is searched. In the display screen of FIG. 1, the number of elements connected to the first shape element 3 is 4. Regarding this shape element 4, it is determined in step S82 whether it is a terminal shape, and in step S83 it is determined whether it is a reciprocating path. However, since both determination results are NO, steps S82 and S83 are passed, and in step S84, only the machining path data is output as is, and the process returns to step S81.

Next, the elements connected to the shape element 4 are the slit-like element 5 and the shape element 6, and the elements to which the slit processing attribute is added are processed preferentially. That is, since the determination result of whether the slit-shaped element 5 is on the reciprocating path in step S82 is YES, the process moves to step S85, and the forward machining path data and the setting data of the offset amount of zero are output. In step S86, only the return machining route data is output. In step S87, continuous shape elements are continuously searched. In step S88, it is determined whether the consecutive elements are a round trip route. In the display screen of FIG. 1, the element connected to the slit-like element 5 is 6, which is not a slit-like element, so the determination result in step S88 is NO, and the process moves to step S89, where the return data of the machining path and offset amount is output. Step S81
Return to

After this, in the same way as the above processing procedure, NC data blocks are sequentially output for the shape elements (including the slit-shaped elements 7 and 9) connected to the shape element 6. When the element 11, which is the end shape of the processed shape, is reached, the determination result in step S82 as to whether it is the end shape becomes YES, and the process moves to step S90. In step S90, only the machining route data is output, and in step S91, escape route data (offset cancel block) toward the machining end point 2 is finally output. A machining program that is a list of NC data output in this way is shown in FIG.

Each data block shown in the NC machining program shown in FIG. 4 will be explained one by one. First, in block 40, an offset amount is assigned to variable H50. This is because this variable H50 is used in the later offset amount setting block. Next, in block 41, a coordinate system is set, and in block 42, offset starting block data corresponding to the machining path 20 is output. In order to perform an offset at this time, an offset amount (variable H50) is substituted into the offset number H1 so that the offset becomes effective.

Next, in block 43, a block corresponding to the machining path 21 is output. The following block 44 corresponds to the machining path 22, and offset is also effective here. However, once the offset amount is set, it does not change until it is changed thereafter, so the offset amount is not set in block 44. Since the next block 45 is a block in which the slit-shaped element 5 is processed and no offset is performed, zero is substituted as the offset amount into the offset number H1 so that no offset is performed. The following block 46 corresponds to the machining path 24, and since the offset amount remains zero here as well, no offset amount is set. Block 47 corresponds to the machining path 25, and in order to make the offset valid here, the offset amount (variable H50) is substituted into the offset number H1 to make the offset valid. Thereafter, in the same way, the offset amount is set to zero for slit-like elements 7 and 9 so that the offset becomes invalid, and the offset amount is set again at the exit block of the machining path of the slit-like element so that the offset becomes valid for the other machining paths. I'm trying to set it up. The block 52 corresponds to the machining path 33, and is an offset cancellation block toward the machining end point. Then, the machining ends at the final program end block 53.

In the above embodiment, an example of slit machining by wire electric discharge machining has been described, but it goes without saying that the present invention can be applied to all other machining methods that do not involve offset. For example, it can be applied to forced cutting at corners by wire electrical discharge machining.

Furthermore, in the present invention, the selection instruction for setting the tool offset amount on the machining path as the first set value or the second set value (ie, zero) for each NC machining element is indicated by a graphic. When performed on the display screen, NC machining data for each case is automatically generated based on this selection instruction. Therefore, for each NC machining element, there are multiple correction amounts for the machining position, for example, when the first setting value, the second setting value, and the third setting value (zero, for example) are used. According to the present invention, if a selection instruction is given on the graphic display screen as to which set value the machining position correction amount should be, NC machining data for each case is automatically generated based on the selection instruction. It is possible.

[0032]

[Effects of the Invention] As described above, according to the present invention, when the processing elements forming the processing shape of the workpiece include processing elements such as slit-shaped cutting processing elements that make offset invalid, However, by specifying these in the CAD/CAM device and defining them on the graphic display screen, the tool compensation amount will be zero on the machining path of the machining element where offset is invalidated, and on the machining path of other machining elements. Since the NC machining data is automatically generated sequentially so that the tool compensation amount becomes the specified value, the generation efficiency of the NC machining program in the CAD/CAM device increases and the NC
The effect of improving the reliability of machining programs can be expected.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of a machining shape display screen of a CAD/CAM device according to the present invention.

2 is a diagram showing an example of a machining shape display screen before defining the slit-like cutting machining element of FIG. 1; FIG.

FIG. 3 is an explanatory diagram showing a machining trajectory including the slit-like cutting process in FIG. 1;

FIG. 4 is a diagram showing an example of an NC machining program automatically generated by the CAD/CAM device according to the present invention.

FIG. 5 is a block diagram showing the configuration of a CAD/CAM device according to the present invention.

FIG. 6 is a flowchart showing a procedure for defining slit-like cutting according to the present invention.

FIG. 7 is a detailed flowchart of the NC machining data generation procedure in FIG. 6;

FIG. 8 is a diagram showing an example of a graphic display screen of a conventional CAD/CAM device.

9 is a diagram showing an example of a machining program in the NC machining of FIG. 8. FIG.

10 is a diagram illustrating offset machining in the NC machining of FIG. 8. FIG.

FIG. 11 is a diagram illustrating slit-like cutting in conventional NC machining.

FIG. 12 is a diagram showing an example of a machining shape display screen of a conventional CAD/CAM device.

FIG. 13 is a flowchart showing a processing procedure when performing conventional slit-like cutting.

FIG. 14 is a diagram showing an example of an NC machining program for machining the slit-like cutting element of FIG. 12;

[Explanation of symbols]

1,107 Processing start point 2,108 Processing end point 3-11,100-106,160-163 Shape element 5, 7, 9 Slit-shaped cutting element 12-14
Reciprocating processing symbols 20-22, 25, 28, 31-33, 109-117
Offset machining path 23, 24, 26, 27, 29, 30, 161, 162
Non-offset machining path 40, 130 Offset amount setting block 41, 13
1 Coordinate system setting blocks 42, 132 Offset start blocks 43-51, 133-139 Machining trajectory blocks 52, 140 Offset cancel blocks 53, 141 Program end block 60
Graphic display device 61 ROM 62 RAM 63 CPU 64 Keyboard 65 Tablet 66 Stylus pen 67 Machining menu 150, 169 Desired shape 167, 168 Intersection of machining trajectory 171-173 Shape elements corrected by division 190-19
2,193 Modification block that makes the offset amount zero

Claims (1)

[Claims] 1. Each machining element forming the machining shape of a workpiece is defined on a graphic display screen in a CAD or CAM device, and when the machining element includes a slit-like cutting element, the slit Specify a slit-shaped cutting element, define its reciprocating machining path on the graphic display screen, and display a reciprocating machining symbol near the reciprocating machining path of the defined slit-shaped cutting element on the graphic display screen. and based on each machining element forming the defined machining shape,
Automatically generate sequential numerical control machining data so that the tool compensation amount becomes zero on the reciprocating machining path of the slit-shaped cutting element and the tool compensation amount becomes a specified value on the machining path of other machining elements. A method for generating a machining program in a CAD/CAM device, characterized in that a numerically controlled machining program is generated by.