JPH0372412B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for creating NC data for die machining, and particularly relates to a method for creating NC data for die machining formed on a die plate of a progressive die.

<Prior art> As shown in Fig. 4, the progressive die CAD/CAM system 1 includes a mold design system (CAD system) 1a that automatically designs molds, and an NC system that creates NC data 2 for mold processing. Data creation system (CAM)
system) 1b. In addition, each system 1
Although a and 1b may be configured with separate devices, in reality, the system is constructed as appropriate by loading a system program for mold design and a system program for creating NC data into one computer.

In such a progressive die CAD/CAM system 1, the CAD system 1a interactively designs the product layout, number of stages, pitch, etc. based on the input product shape (blank layout processing), and then designs the punch shape or punch shape. At the same time, the CAM system 1b automatically designs each plate that makes up the progressive mold using the mold concept processing (street layout processing), and the CAM system 1b inputs the shape data of each plate automatically designed by CAD and performs NC processing. Create and output data.

By the way, a die for receiving a punch must be formed on the die plate of the plate, and this die is machined by a wire-cut electric discharge machine. Therefore, when designing a die plate using a CAD system, it is necessary to input data necessary for die processing using a wire cut electric discharge machine. Therefore, when designing a die plate, after identifying the die shape,
The RPF (see Figure 5) is displayed on the display screen, and then the start point P _s for wire cutting processing and the start-up element of the die shape are displayed.
The SUE is specified, and the specified data and die shape data are used to create NC data for die machining using a wire cut electrical discharge machine.

<Problems to be Solved by the Invention> In the past, no consideration was given to the distance l between the start point _Ps and the start-up element SUE of wire cutting, and no special error checking was performed. That is, the distance l may be short or long.

Generally, when the processing direction of a wire electrode changes, irregular forces act on the wire electrode, and if cooling water is not sufficiently applied to the wire electrode at this time, the wire electrode is likely to break. Therefore, if the position of the wire cut start point P _s is too close to the start-up element SUE, when the wire electrode reaches the start-up element, the cooling water jetted from the nozzle will not be sufficiently applied to the wire electrode. Disconnection occurs.

Figures 6 and 7 are explanatory diagrams for explaining the amount of cooling water applied depending on the position of the start point, and Figure 6 is a diagram showing the position of the wire cut start point.
When the distance l from P _s to the start-up element SUE (to the end of the processed shape) is larger than the radius d/2 of the nozzle NZ, Fig. 7 shows the case when l is smaller than d/2, and Fig. A is a schematic diagram. Figure B is a side view.

If l≧(d/2) (see Fig. 6), the wire electrode WE starts moving from the wire cut start point _Ps and reaches the start-up element SUE, as shown in Fig. 6B. The cooling water CLW spouted from the nozzle NZ is not blocked by the workpiece WK and is sufficiently applied to the wire electrode WE.

However, if l<(d/2) (see Fig. 7), the wire electrode WE starts moving from the wire cut start point _Ps, and the start-up element
When SUE is reached, a portion of the cooling water CLW spouted from the nozzle NZ is absorbed into the workpiece as shown in Figure 7B.
It is blocked by WK and does not fully cover the wire electrode WE. As a result, the wire electrode WE is insufficiently cooled and breaks.

From the above, an object of the present invention is to provide an NC data creation method that can monitor whether the distance of a start-up element from a wire cut start point is appropriate or inappropriate when designing a die plate or the like.

<Means for solving the problems> Figure 1 shows a diagram of a progressive die design to which the present invention can be applied.
1 is a block diagram of a CAD/CAM 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 X-Y plotter, 15 is a disk controller, 16a is a floppy disk in which a system program for mold design is stored, and 16b is an NC
A floppy disk 16c stores a system program for creating data, and a floppy disk 16c stores created NC data.

CRT is a display screen, GF is a product shape,
DF1 to DF3 are punched shapes (die shapes).

<Function> Display die shapes DF1 to DF3 on the display screen.
Display on CRT and specify one die shape (for example, DF1). Next, determine the starting point (P _s ) and die shape for wire cutting.
Identify the startup element (SUE) of DF1.

After that, calculate the shortest distance l from the start point (P _s ) to the start-up element (SUE),
The distance and the radius value d/2 of the nozzle that spouts cooling water
(preset as a parameter), and if the distance is smaller than the nozzle radius, an alarm is generated to call the operator's attention, and if it is larger, the specified wire cut start point and start-up element are used. Create NC data for die machining using a wire cut electrical discharge machine.

<Example> Figure 1 shows a progressive die design to which the present invention can be applied.
1 is a block diagram of a CAD/CAM 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 X-Y plotter, 15 is a disk controller, 16a is a floppy disk in which a system program for mold design is stored, and 16b is an NC
A floppy disk 16c stores a system program for creating data, and a floppy disk 16c stores created NC data.

CRT is a display screen, GF is a product shape,
DF1 to DF3 are punched shapes, that is, die shapes.

A menu table 13b is pasted on the tablet surface 13a of the tablet device 13, and predetermined items written on the menu table can be selected using the mouse 1.
By picking with 3c, you can input various items and data.

FIG. 2 is an overall view of this menu table, including a product shape input section T1, a blank layout section T2,
Stritz layout section T3, mold concept section T4, processing data output section T5, drawing output section T6, list output section T7, various data setting section T8, drafting processing section T
9. Alphabet/symbol input section T10, numerical value/
A mold shape input section T11, a shape conversion section T12, a parts menu section T13, a list menu section T14, a drawing menu section T15, etc. are provided.

The mold concept section T4 is provided with a "WC start point" item M1 for setting the wire cut start point, and the numerical value/shape input section T11 is provided for instructing the shape and wire cut start-up direction (start-up element). Arrow key items (→, ↓, ←, ↑, etc.) M2 are provided.
Note that the keyboard is also provided with arrow keys.

FIG. 3 is a flowchart of NC data creation processing according to the present invention.

(1) A system program for mold design is loaded from the floppy disk 16a to the RAM 11c under the control of loading (stored in the ROM 11b), thereby making the apparatus into a mold design system.

(2) After that, the progressive die is automatically designed using a well-known method. In other words, the CAD system 1a interactively places the product based on the input product shape.
The number of stages, pitch, etc. are designed (blank layout processing), and then the punch shape or punch shape (die shape) is automatically designed (strip layout processing).

(3) The die shapes DF1, DF2, etc. automatically designed by the strip layout process are the part shape GF
Along with graphic display device CRT
In the state depicted in (see Figure 1),
After picking the mold concept section T4 (Fig. 2) with the mouse 13c, pick the "WC start point" item M1.

(4) By picking the "WC start point" item M1, the processor 11a asks the CRT which die shape it is.

(5) In response to the question, pick a predetermined die shape DF1 using the mouse 13c.

(6) By picking the die shape DF1, the processor asks the CRT about the wire cut start point.

(7) This allows you to move the mouse 13c and
Position the upper cursor at a predetermined wire cut start point _Ps and input the coordinate values of the point.

(8) Next, the processor asks the CRT the direction in which the wire should be moved from the wire cut start point _Ps (start-up direction). Note that the die shape element in the start-up direction from the wire cut start point P _s is the start-up element.
It becomes SUE.

Further, the question may be asked about the start-up element instead of the start-up direction.

(9) From the question about the start-up direction, enter the start-up direction using the arrow keys →, ↓, ←, and ↑ on the keyboard 14a, or use the predetermined arrow key item M listed in the menu table 13b.
2 with the mouse 13c.

Note that the configuration may be such that the cursor is moved using the mouse 13c and the start-up element SUE is designated with the cursor.

(10) With the above operations, the startup element
Once SUE is specified, the distance l from the start point _Ps to the start-up element SUE is calculated. Incidentally, since the coordinate values of the wire cut start point _Ps and the start-up element are known, the distance l can be easily calculated.

(11) Once the distance l is determined, determine whether the distance is larger or smaller than the radius value d/2 of the nozzle that spouts cooling water.
Note that the nozzle diameter d is set in advance as a parameter in the system program, and is stored in the parameter storage area of the RAM 11c by reading the system program.

(12) If l≧(d/2) (see Fig. 6), no error message will be drawn on the CRT, so from now on, the operator will have to check the wire cut start point P _s , the start-up element, and the picked die shape. Performs the output operation to the floppy disk 16c of DF1. That is, the "processing data output section" T5 on the menu 13b is picked, and then the "shape data" item T5a is picked.

(13) As a result, a question screen asking about the plate is drawn on the display screen CRT, so if a plate name is input in response to the question, the shape data of the plate is output to the floppy disk 16c.

(14) After that, the operator turns off/on the power, and then stores the system program for creating NC data from the floppy disk 16b into the RAM 11c, making the device an NC data creating system (CAM system).

(15) Thereafter, the NC data creation system creates NC data based on the shape data stored in the floppy disk 16c, outputs it to the floppy disk 16c, and ends the process.

(16) On the other hand, in step (11) l<(d/2)
If so (see Figure 7), an error message will be displayed in red on the display screen to the effect that the position of the wire cut start point _Ps is inappropriate, or other alarms will be generated.

(17) The operator determines whether or not to change the position of the wire cut start point by looking at the error message. If there is no need to change the position, perform the process from step (12) onwards, and if it is necessary to change it, proceed to step (12). 6) Repeat the following process.

<Effects of the Invention> According to the present invention, the distance from the set start point to the start-up element is calculated,
This distance and the radius of the nozzle that spouts cooling water are determined, and if the distance is smaller than the nozzle radius, an error message or alarm is generated. It is possible to monitor whether the position is suitable or not, and to prevent the wire electrode from being insufficiently cooled and breaking when it reaches the start-up element.

[Brief explanation of drawings]

Figure 1 shows a progressive die design to which the present invention can be applied.
A block diagram of the CAD/CAM system, Fig. 2 is a menu table, Fig. 3 is a flow chart of the processing of the present invention, Fig. 4 is a block diagram of the CAD/CAM system.
The figure is a block diagram of the progressive die CAD/CAM system, Figure 5 is an explanatory diagram of the conventional wire cut start point and how to identify start-up elements, and Figures 6 and 7 are the application of cooling water depending on the position of the start point. FIG. 3 is an explanatory diagram for explaining the situation. 11a...Processor, 11b...ROM, 1
1c...RAM, 12...Graphic display device, 13...Tablet device, 14a...
Keyboard, CRT...display screen, GF...
...Product shape, DF1 to DF3...Punching shape (die shape).

Claims (1)

[Claims] 1. A die shape is displayed on a display screen to specify a start point and a start-up element of the die shape for wire cut machining, and a wire cut electrical discharge machine is created using these specified data and die shape data. In the NC data creation method for creating NC data for die machining, the distance from the specified start point to the start-up element is calculated, and the size of the radius value of the nozzle that spouts cooling water is determined from this distance. and generating an alarm when the distance is smaller than the nozzle radius.