JP2633624B2 - NC data creation method for punching shape processing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial application field> The present invention relates to a method for creating NC data in which a wire electrode is approached to a punching shape from a start point and processed according to the punching shape in wire cutting of a punching shape in a mold. .

<Conventional technology> As shown in Fig. 6, the progressive die CAD / CAM system 1
Die design system (CAD system) for automatic die design 1
a, and an NC data creation system (CAM system) 1b for creating NC data 2 for die machining. Each of the systems 1a and 1b may be composed of separate devices. However, in practice, the system is appropriately constructed by loading a mold design system program and an NC data creation system program into one computer. doing.

In the progressive die CAD / CAM system 1, the CAD system 1a interactively designs the product arrangement, the number of stages, the pitch, etc. based on the input product shape (blank layout processing), and then punches or forms the die. And interactively create (strip layout processing), and automatically design each plate that composes the progressive die by the mold concept processing. The CAM system 1b inputs the shape data and processing information of each plate automatically designed by CAD1a. Create and output NC data.

Meanwhile, a die for receiving a punch must be formed on a die plate among the plates, and the die is processed by a wire cut electric discharge machine. For this reason, when designing die plates using CAD systems,
After specifying the die shape, the die shape DF (see FIG. 5) is displayed on the display screen, and thereafter, a start point Sp for wire cutting and an element (startup element) SUE to which the wire electrode approaches from the start point Sp.
To identify. Then, using the specified data and the die shape data, the start point Ps is determined by the wire electrode.
From, start point SUE approach point Ap
The tool path (NC data) to be machined to the die shape along the die shape is created. Note that the direction (clockwise or counterclockwise) of processing along the die shape from the approach point Ap is set by system parameters.

<Problems to be Solved by the Invention> However, the conventional method has a problem that the processing accuracy near the approach point Ap becomes worse than the processing accuracy of other parts, and the punch cannot enter the die smoothly. . This is because the processing length per unit time when the wire electrode processes the vicinity of the approach point Ap is different from the processing time per unit time when processing other portions.

Accordingly, an object of the present invention is to provide an NC data creation method for punching shape processing in which a punch can be smoothly inserted into a die.

<Means for Solving the Problems> FIG. 1 is a schematic explanatory diagram of NC data creation processing for punching shape processing according to the present invention.

PRF is the specified punched shape (die shape), ELi (i = 1,
2) are shape elements constituting the punched shape PRF, Sp is a start point of wire cutting, Ap is an approach point, HCIR is a semicircular shape, and r is a radius of the semicircular HCIR.

<Operation> An intersection (approach point) Ap obtained by dropping a perpendicular to the approach shape element EL1 from the start point Sp is obtained, a semicircle HCIR having a predetermined radius r with the approach point Ap as a central coordinate value is obtained, and the semicircle is extracted. The shape added to the shape PRF is set as the actual cut shape, and the wire electrode is approached at the intersection of the perpendicular and the semicircle, and processed as the actual cut shape.
Create NC data.

<Example> FIG. 2 is a CAD / CA for progressive die design to which the present invention can be applied.
It is a block diagram of M system.

11a is a processor, 11b is a ROM, 11c is a RAM, 12 is a graphic display device, 13 is a tablet device, 14a is a keyboard, 14b is an XY plotter, 15 is a disk controller, and 16a is a system program for mold design. 16b is a floppy in which a system program for creating NC data is stored, and 16c is a floppy in which the created NC data and the like are stored.

CRT is a disc display screen, GF is a product shape, DF1 to DF4
Is a punched shape, that is, a die shape.

In the tablet device 13, 13a is a tablet surface, 13b
Is a menu table, and 13c is a tablet cursor. Menu table 13b is pasted on tablet surface 13a,
Various items and data can be input by picking predetermined items written in the menu table 13b with the tablet cursor 13c. FIG. 3 is a partially detailed view of such a menu table. FIG. 3 (a) shows a function menu relating to automatic design of a progressive die, and FIG. 3 (b) shows a menu for selecting mounting hole machining. 3 shows the parts menu of the. FIG. 3A shows a product shape input section T1, a blank layout section T2, a strip layout section T3, and a mold concept section.
T4 and the like are provided, and a “WC start point” function item TSa and the like are provided in the deformed portion (cut shape) design of the mold concept part T4. In FIG. 3B, a “WC start point” component item TSb and the like are provided.

First, the operator loads a system program for mold design in advance from the floppy 16a to the RAM 11c under the control of a loading program (stored in the ROM 11b) to make the apparatus a mold design system.

Thereafter, the progressive die is automatically designed by a known method.
That is, the CAD system 1a interactively designs the product arrangement, the number of stages, the pitch, etc. based on the input product shape (blank layout processing), and then automatically designs the punch shape or the punch shape (die shape) (strip shape). Layout processing).

FIG. 4 is a flowchart of the process of the present invention. Hereinafter, the NC data creation processing for punching shape processing according to the present invention will be described with reference to the flowchart of FIG. It is assumed that the cut shapes DF1, DF2,... Automatically designed by the strip layout processing are drawn on the CRT of the graphic display device 12 together with the component shape GF (see FIG. 2).

The operator uses the tablet cursor 13c to perform the type design unit T4.
After picking (Fig. 3 (a)), "WC start point"
Pick the function item TSa.

The processor 11a asks the CRT which punching shape is to be selected by picking the "WC start point" function item TSa. In response to the query, the processor 11a picks up a predetermined punching shape DF1 (step 101).

Next, the processor 11a asks for a part to be attached to the CRT, so picks the "WC start point" part item TSb in the parts menu (FIG. 3 (b)) (step 102) and determines the position of the wire cut start point Ps. Picking or inputting the coordinate value of the point Ps using the keyboard 14a (step 103).

Next, the processor 11a asks the CRT about the shape element approached by the wire electrode from the start point Ps, and picks a predetermined shape element EL1 (FIG. 1) (step 104).

Processor 1 by picking approach shape element EL1
1a is the approach shape element EL1 from the start point Sp
The intersection point (approach point) Ap having the perpendicular drawn down is determined, the semicircular HCIR having a predetermined radius r with the approach point Ap as the central coordinate value is determined, and the semicircular HCIR is extracted.
The shape PRF (FIG. 1) added to DF1 is redefined as an actual cut shape (step 105). Note that the predetermined radius r is set in advance by a system parameter.

With the above, the input of the data necessary for creating the NC data for machining the punched shape DF1 is completed. After that, a mold concept design is performed, and when the design is completed, the operator operates the floppy disk 16b.
, The system program for creating NC data is stored in the RAM 11c to form an NC data creating system (CAM system). When the die plate is specified, the processor
11a is an intersection Pa (actually, a point Po which is offset by the radius of the wire electrode) from the start point Sp with the semicircle along the perpendicular line based on the redefined shape data.
f), the tool path (dot-dash line in FIG. 1) offset along the redefined shape PRF is obtained, NC data is created (step 106), and NC data creation processing for punching shape processing is performed. finish.

<Effects of the Invention> As described above, according to the present invention, an intersection where a perpendicular is dropped from the start point to the approach shape element is obtained, a semicircle having a predetermined radius r having the intersection as a central coordinate value is obtained, and the semicircle is extracted. The shape added to the actual shape was used as an actual shape, and NC data was created so that the wire electrode approached the intersection of the vertical line and the semicircle to create the NC data for machining according to the actual shape. The punch can be reliably inserted into the die (punched shape) even if it is not good.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of NC data creation processing for punching shape processing according to the present invention, and FIG. 2 is CAD / CAM for progressive die design to which the present invention can be applied.
FIG. 3 is a partial detailed view of a menu table of the present invention, FIG. 4 is a flowchart of NC data creation processing for punching shape processing of the present invention, FIG. 5 and FIG. FIG. 11a: Processor, 11b: ROM, 11c: RAM, 12: Graphic display device, 13: Tablet device, 13b: Menu table, 13c: Tablet cursor, 14a: Keyboard, PRF: Punch shape , Sp …… Start point, Ap …… Approach point, HCIR …… Semicircular

 ────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-62-69302 (JP, A) JP-A-62-259721 (JP, A)

Claims (1)

(57) [Claims] 1. A die cutting shape, a wire cutting start point for wire cutting the die cutting shape,
In the wire cutting process, specify the shape element to which the wire electrode approaches from the start point and create NC data for wire cutting according to the cutting shape. An intersection point where the perpendicular is dropped on the shape element is obtained, and a predetermined radius r having the intersection as a center coordinate value on the extension side of the perpendicular line
The semi-circle is obtained, and the shape obtained by adding the semi-circle to the cut shape is set as the actual cut shape, and the wire electrode is approached at the intersection of the perpendicular and the semi-circle to create NC data for processing according to the cut shape. A method for creating NC data for machining punched shapes.