JPH0519838A - Product manufacture simulation system of cad system for sequentially fed metallic die - Google Patents

Abstract

PURPOSE:To provide the product manufacture simulation system of the CAD system for the sequentially fed die which can prevent misdesigning and erroneous machining. CONSTITUTION:Machining information on bending or punching regarding generated punch shapes and stages where the respective punch shapes are arranged are set and stored in the RAM 2 of the CAD system previously, machining shapes are accumulated in following stages, stage by stage, in order according to the value of a stage number storage register RS regarding the array order of the stages and the feeding direction of a material, and the machining shapes accumulated in the respective stages are displayed graphically on a CRT device 4 as machining shapes at the completion stage of press machining, stage by stage, thereby informing an operator of the machining shapes corresponding to actual machining processes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a product production simulation system in a progressive die CAD system.

[0002]

2. Description of the Related Art The punch shape for punching and bending is CA
A CAD system for progressive die is already known in which stages for arranging the punch shapes are allocated at the stage of being created by the D system, and the punch shapes themselves are planarly displayed for each stage.

When a CAD system for progressive die of this kind is used to simulate the production of products, the operator observes the punch shape itself displayed on each stage to perform machining operations such as punching and bending for each stage. In consideration of the above, and by superimposing the machining operation by the previous stage on the machining operation by the relevant stage through a thought experiment, the actual machining shape at the stage when the machining operation of each stage is completed is judged. Was there.

[0004]

However, in the conventional CAD system for progressive die, only the punch shape is displayed for each stage, and in the case of bending and the like, the punch shape itself shows the processed shape. Since it is not always the case, it is difficult to assume the actual machining shape, and it is also necessary to consider the machining operation in the previous stage in order to judge the actual machining shape. If you rely only on thought experiments, you may make unexpected mistakes.

For example, when performing a press work in which a punched shape is arranged in a bent shape, it is usually necessary to perform the punching operation of the internal shape and then the entire bending operation, and the bending operation is erroneously performed. If the punch shape for punching is placed on the previous stage, it may become impossible to machine, but if the punch shape for punching operation and the punch shape for bending operation are placed on different stages, there will be a gap between the shapes. There is a possibility that it is difficult to grasp the engagement relationship of No. 2 and each punch shape is arranged on the wrong stage. In addition, when multiple bending processes are performed in close proximity to each other, the bending shapes themselves may interfere with each other, making it impossible to process. However, in the case where the punch shapes for bending operations are arranged on different stages, respectively. However, the engagement relationship between the shapes becomes unclear, and it is difficult to detect mutual interference and the like caused by bending.

Therefore, an object of the present invention is to solve these drawbacks of the prior art, and perform a simulation display faithfully reproducing the actual machining process at the stage when the design of the punch shape and the stage allocation by the CAD system are completed. It is possible to provide a product creation simulation method in a CAD system for progressive die, which can prevent design errors and erroneous processing from occurring.

[0007]

According to the present invention, the bending or punching processing information concerning the punch shape created by the CAD system and the stage on which each punch shape is arranged are pre-CA.
It is set and stored in the storage device of the D system, and the processing of each stage is performed by the microprocessor of the CAD system based on the arrangement order of the stages, the feed direction of the material, the punch shape arranged on each stage and its processing information. The above object was achieved by accumulating shapes in the next stage and displaying the processed shape graphically for each stage.

[0008]

After the punch shape is created by the CAD system, the operator sets and stores the bending or punching processing information regarding each punch shape and the stage on which each punch shape is arranged in the storage device of the CAD system.

The CAD system microprocessor is
Based on the arrangement order of the stages, the feed direction of the material, the punch shape placed on each stage and its machining information, the machining shape for each stage is obtained according to the stage arrangement order, and the machining shape for each stage is sequentially determined. By accumulating in the next stage, the machining shape at the time when the machining operation of each stage is completed is obtained for each stage, and this machining shape is graphically displayed for each stage.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a main part of an automatic programming apparatus which constitutes a CAD system of one embodiment.
Reference numeral 1 is a microprocessor (hereinafter referred to as CPU), 7 is a ROM storing a control program for the automatic programming device, and 2 is an RA storing a system program loaded from a floppy disk 11 and various data.
M, 3 is a keyboard, 4 is a CRT display device (hereinafter referred to as CRT) as a graphic display, 9 is a tablet device, 8 is a disk controller, 11 is a floppy disk storing system programs and the like, 10
Is an XY plotter for outputting a drawing and 5 is a printer, and these elements are connected via a bus 6.

The tablet device 9 has a screen-corresponding area 9a and a menu table 9b. The tablet cursor 9c is moved within the screen-corresponding area 9a, the graphic cursor on the CRT 4 is moved, and an instruction operation is performed to perform a CRT.
Various menu items are selected from the system program prepared in the floppy disk 11 by designating an arbitrary position on the display screen of No. 4 or moving the tablet cursor 9c on the menu table 9b and performing an instruction operation. It is like this.

The general function of this type of automatic programming device and the general design operation using the automatic programming device are already known, so the description thereof will be omitted. In the following, a punch shape directly related to the method of the present invention will be produced. The processing and the simulation processing will be described.

To start the punch shape creation, after turning on the power to the automatic programming device, first select "Punch shape creation" in the menu table 9b with the tablet cursor 9c, and the program is driven by the control program of the ROM 7. A system program relating to punch shape creation and simulation is downloaded from the floppy disk 11 to the RAM 2 by the processing of the CPU 1, and the punch shape creation processing as shown in FIG. 2 is performed on the CPU 1 of the automatic programming device which is the microprocessor of the CAD system. Let it start.

Next, the operator stores a shape memory area (hereinafter, referred to as a shape memory area) of the RAM 2 for storing the created punch shape.
A work layer), a shape storage area of the RAM 2 for storing a plurality of stages in which each punch shape is arranged (hereinafter referred to as a semi-working layer), and a shape storage area of the RAM 2 for executing a simulation (hereinafter referred to as a simulation). Layer), the plate thickness and width W of the material to be used, the volume change rate of the material regarding bending, the array pitch P of the stages, and the array number N indicating the number of arranged stages are set and input via the keyboard 3. ,Less than,
As in the conventional case, the keyboard 3 and the tablet device 9 are operated to set a stage shape for one stage on the display screen of the CRT 4, and positions are designated in the stage shape to draw punch shapes one after another. Shape data in RAM2
In the work layer (step S1, step S
2).

FIG. 6 is a view showing an example of a display screen on the CRT 4 when the punch shape is drawn by setting the stage shape for one stage, and the punch shape 100 on the CRT 4 is shown.
a to 104a are product diagrams (a) as shown in FIG.
Is a plan view, b is a right side view, and c is an elevation view). Reference numeral 101 shown in FIG.
Reference numerals 102 and 104 denote bent portions, a bent portion 103 is further provided in the bent portion 102, and 100 is a contour shape. Since the punch shape itself is directly drawn on one stage on the display screen on the CRT 4, the punch shape 104a for the bent portion 104 and the punch shape 10 for the bent portion 102 are drawn.
The punch shape 103a for the 2a and the punched-out portion 103 is drawn in a plane as shown in FIG. In this example, the case where two products are taken from one stage is shown.

When the necessary punch shape has been created, the operator operates the shape creation end key of the keyboard 3 to end the punch shape creation, and the bending operation is performed by the graphic cursor on the CRT 4 which is interlocked with the tablet cursor 9c. The bending line is specified for the punch shape to be formed, the bending radius of the bent portion and the bending angle of the straight portion are input via the keyboard 3, and the punch shape to be bent and the punch shape to be punched are respectively specified. Are sequentially selected by the graphic cursor, and the numbers 1 to N of the stages on which the punch shapes are to be arranged are input from the keyboard 3 and stored in the corresponding stage of the quasi-working layer of the RAM 2 together with the shape and position data of each punch shape. , Decide the stage to place the punch shape (step S3, step S4), punch shape To end the creation process.

In the example shown in FIG. 6, each of the linear element 102b of the punch shape 102a and the linear element 104b of the punch shape 104a to be bent is designated by a graphic cursor and selected as a bending line. ..

FIG. 7 is a conceptual diagram visually showing the condition of the semi-working layer of the RAM 2 at the stage when the punch shape creating process is completed, corresponding to the setting conditions of FIG. At the stage in which the stage shape for one stage, the array pitch P and the array number N of the stages are set in the process of step S1 in the shape creating process, first, the necessary number of stages are preset based on these data, and , No. 1 of the stage in which the punch shapes 102a and 104a to be bent and the punch shapes 100a, 101a and 103a to be punched are selected and the punch shapes are to be arranged in the process of step S3.
When ~ N is input from the keyboard 3, each punch shape 1 is input according to the stage number specified by the keyboard 3.
The shape and position data of 00a to 104a and the attribute data such as the bending line of each punch shape 100a to 104a and the bending radius and the bending angle are stored in the corresponding stage of the semi-working layer. The semi-working layer is a hidden layer.

In FIG. 7, the number of stages N is set to 5, and the punch shape 101a to be punched is selected by the graphic cursor and input from the keyboard 3 to place the punch shape 101a on the stage 1 of the quasi-working layer. Similarly, the punch shape 103a to be punched is placed on the stage 2 of the semi-working layer, and the punch shape 102a to be bent is made.
Is placed on the stage 3 of the semi-working layer, and the punch shape 104a to be bent is placed on the stage 4 of the semi-working layer, and the punch shape 100 to be punched.
FIG. 3 shows an example in which a is arranged on the stage 5 of the quasi-working layer, and the shapes of the punch shapes 102a and 104a are formed on the stages 3 and 4 of the quasi-working layer on which the punching shapes 102a and 104a to be bent are arranged. The attribute data regarding the bending line, the bending radius, the bending angle, and the like are stored together with the position data.

The operator who has created the punch shape and decided the stage allocation in the above-described processing then selects the item "Simulation" in the menu table 9b with the tablet cursor 9c, and the CPU of the automatic programming device is selected.
1 will start the simulation process as shown in FIG. It is also possible to immediately execute the simulation process by detecting the operation of the definition completion key or the like in the process of step S4 in the punch shape creation process.

CPU 1 which started the simulation processing
First, based on the stage shape for one stage, the stage arrangement pitch P and the number N of arrangements, and the plate width W of the material set in the process of step S1 in the punch shape creation processing, one stage is provided before and after the N stages. Create a plate shape with total length (2 + N) · P and width W with each margin and RAM
The setting is stored in the simulation layer of step 2 (step T
1), the stage number storage register RS is initialized to 0 (step T2).

Next, the CPU 1 increments the value of the stage number storage register RS by 1 (step T
3), the quasi-working layer RS based on the value of the register RS
The stage is searched and it is determined whether or not the punch shape for the punching shape, that is, the punch shape having no attribute data such as the bending line and the bending radius and the bending angle is stored (step T4, step T5). If the punch shape for the punched shape is stored, the punch shape is created on the RS stage of the simulation layer based on the shape and position data (step T6), and then the process proceeds to step T4. The data of the RS stage of the semi-working layer is searched again. And RS of semi-working layer
If another punch shape for the punched shape is stored in the stage, the same processing as described above is repeatedly executed, and all punch shapes for the punched shape in the RS stage of the semi-working layer are simulated layer. RS
Create on stage.

When it is judged that the punch shape for the punching shape is not stored in the RS stage of the semi-working layer, or all the punching shapes for the punching shape stored in the RS stage of the semi-working layer are stored. When it is created on the RS stage of the simulation layer and the determination result of step T5 is false, the CPU 1 copies all the punch shapes of the RS-1 stage to the RS stage of the simulation layer and sets the machining shape of the previous stage. Accumulated in the relevant stage, the processed shape relating only to the punched shape at the stage of completion of the press work in the RS stage is stored in the RS stage of the simulation layer (step T7)
The current value of the stage number storage register RS is the set value N
Is reached, that is, whether the simulation of only the punched shape for all the stages of the quasi-working layer is completed (step T8). If the current value of the register RS has not reached the set value N, the CPU 1 shifts to step T3 again, increments the value of the stage number storage register RS by 1 corresponding to the feeding direction of the material at the time of machining, and then Until the value reaches the set value N, the above processing is repeatedly executed.

FIG. 8 is a conceptual diagram for explaining the routine of steps T3 to T8 corresponding to the situation of the semi-working layer as shown in FIG.

Since the value of the stage number storage register RS immediately after the execution of the first step T3 is 1, the CPU 1 first searches the stage 1 of the quasi-working layer based on the value of the register RS (step T4), after detecting one of the punch shapes 101a for the punching shape and creating the punch shape 101a on the stage 1 of the simulation layer (steps T5 and T6),
Hereinafter, the processes of steps T4 to T6 are repeatedly executed to detect the second, third, and eighth punch shapes 101a one after another, and the punch shapes 101a on the stage 1 of the simulation layer. To create. Then
When all the punch shapes 101a are created on the stage 1 of the simulation layer and the determination result of step T5 is false, the CPU 1 proceeds to step T7 to copy the punch shape of the previous stage to the stage 1 of the simulation layer. However, at this stage, since RS-1 = 0 and there is no previous stage, the eight punch shapes 101a created by the process of step T6 while the value of the stage number storage register RS is 1 Only those will be stored in stage 1 of the simulation layer (see stage 1 in FIG. 8).

Then, the CPU 1 increments the value of the stage number storage register RS to 2, and then searches the stage 2 of the quasi-working layer to detect the punch shapes 103a for punching shapes one after another by the same processing as described above. Then, the punch shape 103a is created on the stage 2 of the simulation layer. Then, the punch shape 103a
All are created on stage 2 of the simulation layer and the determination result of step T5 is false, the CPU 1
Shifts to step T7, the punch shape of the previous stage, that is, RS-1 = stage 1, is copied to the stage 2 of the simulation layer, and the punch shape 101 is formed together with the eight punch shapes 103a created in the processing of step T6 this time.
a is stored (see stage 2 in FIG. 8).

Next, the CPU 1 increments the value of the stage number storage register RS to 3, and then repeats the same processing as described above. However, the punch shape for punching shape is formed on the stage 3 of the semi-working layer. Is not stored at all, the determination result of step T5 immediately becomes false, the process of step T6 is not executed, and only the process of step T7 is executed. Therefore, in the simulation layer stage 3, the previous stage, that is, RS
-1 = Only the punch shape of the stage 2 is copied, and each of the eight punch shapes 103a and the punch shape 101a is stored in the stage (see stage 3 in FIG. 8).

The stage number storage register RS
Even when the value of 4 is 4, as in the above, only the processing of step T7 is executed. As a result, the stage 4 of the simulation layer has the punch shape of the preceding stage, that is, the eight punch shapes 103a and the punch shape of the stage 3 respectively. 101a
Will be stored (see stage 4 in FIG. 8).

The stage number storage register R
When the value of S reaches the final value 5, the punch shape 100a for the punch shape is detected from the stage 5 of the semi-working layer, and the punch shape 100a is simulated together with the punch shapes 103a and 101a of the preceding stage, that is, the stage 4. It will be stored in the stage 5 of the layer (see stage 5 in FIG. 8).

Next, the CPU 1, which has detected that the value of the stage number storage register RS has reached the set value N in the discrimination processing of step T8, initializes the value of the stage number storage register RS to 0 (step T9). , The creation of simulation data on the bending shape will be started.

The CPU 1 first increments the value of the stage number storage register RS by 1 (step T1).
0), the RS of the semi-working layer based on the value of the register RS
The stage is searched to determine whether or not the punch shape for the bending shape, that is, the punch shape including the bending line and the attribute data such as the bending radius and the bending angle is stored (step T11, step T12). If the punch shape having the bent shape is stored, the value of the stage number storage register RS is stored in the stage number storage register RS '.
(Step T13), and a process for obtaining a processed shape based on the detected punch shape is executed.

That is, the CPU 1 detects the bending position of the punch shape from the data of the bending line of the detected punch shape (step T14), and the plate thickness and the volume change rate of the material preset in the RAM 2 are input. Based on the bending radius of the punch shape and the bending angle of the straight portion, the shape of the bent portion by bending is obtained (step T15), and based on the shape data of the punch shape, the shape of the bent portion and the subsequent straight portion are calculated. Connect the shapes to create the actual machining shape,
The three-dimensional data of the processed shape is stored as new attribute data (step T16), and the actual processed shape is stored in the RS '= RS stage of the simulation layer based on the position data of the punch shape (step T1).
7).

Next, the CPU 1 determines whether or not the current value of the stage number storage register RS 'has reached the stage number N (step T18). If not, the value of the stage number storage register RS' is incremented by one. Then (step T19), the process of step S17 is repeatedly executed for the RS 'stage of the simulation layer. Hereinafter, step T until the value of the stage number storage register RS 'reaches the stage number N
The processing from 17 to step T19 is repeatedly executed to copy the actual machining shape based on the punch shape for the bending shape detected by the RS stage of the semi-working layer to all stages after RS of the simulation layer, Accumulate processed shapes.

Then, the stage number storage register R
When the value of S ′ reaches the number of stages N and the actual machining shape by the punch shape for the bending shape detected by the RS stage of the quasi-working layer is stored in all stages after RS of the simulation layer, the CPU 1 makes a step. The processing moves to T11.

CPU 1 which has shifted to the processing of step T11
Again retrieves the RS stage data in the semi-working layer,
If another punch shape for the bending shape is stored in the RS stage of the quasi-working layer, the same processing as described above is repeatedly performed to perform punching shape for the bending shape in the RS stage of the quasi-working layer. An actual machining shape is created for each of the above, the three-dimensional data of the machining shape is stored as new attribute data, and each of the actual machining shapes is stored in all stages after RS of the simulation layer.

When it is determined that the punch shape for bending shape is not stored in the RS stage of the semi-working layer, or when all punch shapes for bending shape stored in the RS stage of the semi-working layer are stored. On the other hand, the actual machining shape is created, the three-dimensional data of the machining shape is stored as new attribute data, and each of the actual machining shapes is stored in all stages after RS of the simulation layer, and the determination in step T12 is performed. If the result is false, the CPU 1 determines whether or not the current value of the stage number storage register RS has reached the set value N, that is, whether or not the simulation of bending for all the stages of the quasi-working layer has been completed. It is determined (step T20). If the current value of the register RS has not reached the set value N, the CPU
In step 1, the value of the stage number storage register RS is incremented by 1, and the above process is repeatedly executed until the value of the register RS reaches the set value N. Then, when the current value of the stage number storage register RS reaches the set value N and the simulation of the bending process for all the stages of the quasi-working layer is completed, the CPU 1 displays the simulation result based on the shape data of the simulation layer on the display screen of the CRT 4. Then, the simulation process ends (step T21).

FIG. 9 is a conceptual diagram for explaining the routine of steps T10 to T21 corresponding to the situation of the quasi-working layer as shown in FIG.

Since the value of the stage number storage register RS is 1 immediately after the execution of the first step T10, the CPU 1 first based on the value of the register RS,
The stage 1 of the semi-working layer is searched to determine whether or not the punch shape for the bending shape is stored (step T11, step T12). However, since the punch shape for bending shape is not stored at all in the stage 1 of the quasi-working layer, the processes of steps T13 to T19 are not executed, and the stage 1 of the simulation layer retains the state of FIG. 8 as it is. (See stage 1 in FIG. 9).

The stage number storage register RS
Similarly, when the value of 2 is 2, the processing of steps T13 to T19 is not executed, and the stage 2 of the simulation layer retains the state of FIG. 8 as it is (FIG. 9).
See Stage 2).

Then, the CPU 1 increments the value of the stage number storage register RS to 3 and then repeats the same processing as described above, but the punch shape for bending shape is formed on the stage 3 of the semi-working layer. Is stored, the determination result of step T12 is true. Therefore, the first punch shape 1 for the bent shape
The CPU 1 which has detected 02a sets the value 3 of the stage number storage register RS to the stage number storage register R
After storing in S ′ as an initial value (step T13), the processing of steps T14 to T17 is executed to create an actual machined shape by the first punch shape 102a, and three-dimensional data of the machined shape is newly added. And the actual machining shape is stored in the simulation layer based on the position data of the punch shape 102a.
Store in the S'stage (RS '= 3). In this case, since the stage 3 of the simulation layer is not the final stage, the determination result of step T18 is false and the CPU
In the step 1, the value of the stage number storage register RS 'is incremented by 1 in the process of step T19 to set RS' = 4, and then the actual machining shape by the already prepared first punch shape 102a is changed in the same manner as described above. It will be stored in the stage 4 of the simulation layer. Below, CPU
1 repeatedly executes the same processing, and the first punch shape 10 detected in the stage 5 of the simulation layer, that is, the stage 3 of the quasi-working layer until the final stage.
The actual machining shape by 2a is stored. Then, the value of the stage number storage register RS ′ reaches the value N (= 5) of the final stage number, and the actual machining shape by the first punch shape 102a detected in the stage 3 of the semi-working layer is changed. Simulation Layer Stage 3
When it is confirmed in the determination process of step T18 that the data has been stored in all the stages up to stage 5, the CPU 1 shifts to the process of step T11 again, and from the stage 3 of the quasi-working layer to the second, The third and fourth punch shapes 102a are detected one after another, the same processing as described above is repeatedly executed, and the actual processing is performed using a total of four punch shapes 102a detected in the stage 3 of the semi-working layer. The shape is stored in stages 3 to 5 of the simulation layer (see stages 3 to 5 in FIG. 9).

The stage number storage register RS
When the value of 4 is the same as above, the punch shape 10 for the bending shape stored in the stage 4 of the semi-working layer is stored.
4a is detected one by one, and each punch shape 104 is detected.
The actual processed shapes by a are sequentially stored one by one in the simulation layer stages 4 to 5, and finally the actual processed shapes by the four punch shapes 104a are stored in the simulation layer stages 4 to 5. (See stage 4 to stage 5 in FIG. 9).

On the other hand, the stage number storage register RS
When the value of 5 is 5, the processing of steps T13 to T19 is not executed. However, in the simulation layer stage 5, the punch shape 102a is processed by the processing when the values of the stage number storage register RS are 3 and 4. Since the actual machining shape of the punch shape and the actual machining shape of the punch shape 104a are already stored, the state when all the punching and bending are completed is stored (see stage 5 in FIG. 9). ).

Then, the stage number storage register R
When the current value of S reaches the set value N (= 5) and the detection of the bending shape for all the stages of the semi-working layer is completed, the punch shape and the punch shape for the bending shape detected from each stage of the semi-working layer The processed shape according to is stored for each stage of the simulation layer in the material feeding direction, that is, in the state as shown in FIG. 9 by sequentially superimposing in order of each stage, and this shape is stored as a simulation result in step T21. Will be displayed on the display screen of the CRT 4. Since each of the machining shapes created by the punch shape for the bending shape has attribute data based on three-dimensional data, for example, the side surface shape of the machining material is drawn as shown in FIG. It is also possible to have a three-dimensional display such as a angular view.

Further, when the punch shape for the bent shape is detected, the actual processed shape of the punch shape is copied in advance to all subsequent stages.
Even if the bending process is performed again in the subsequent stage, it is possible to accurately draw the actual processed shape corresponding to the bent shape before that.

[0046]

According to the product creation simulation method of the present invention, a simulation display that faithfully reproduces the actual machining process can be performed at the stage when the punch shape design and stage allocation by the CAD system are completed. It is possible to prevent design mistakes, erroneous machining, and the like from occurring, because the operator does not need to think and experiment.

[Brief description of drawings]

FIG. 1 is a block diagram showing a main part of an automatic programming device that constitutes a CAD system according to an embodiment.

FIG. 2 is a flowchart showing an outline of punch shape creation processing by the automatic programming device of the embodiment.

FIG. 3 is a flowchart showing an outline of simulation processing by the automatic programming device of the embodiment.

FIG. 4 is a continuation of FIG.

FIG. 5 is a diagram showing an example of a product shape.

FIG. 6 is a diagram showing an example of a CRT display screen in punch shape creation processing.

FIG. 7 is a conceptual diagram showing a situation of a semi-working layer at the stage when the punch shape creating process is completed

FIG. 8 is a conceptual diagram showing a simulation process by a punch shape for a punched shape.

FIG. 9 is a diagram showing a simulation process and a display result by a punch shape for a bending shape.

FIG. 10 is a diagram showing an example in which a simulation result is displayed from the side.

[Explanation of symbols]

 1 Microprocessor (CPU) 2 RAM 3 Keyboard 4 CRT display device 100a to 104a Punch shape

Claims (1)

Claims: 1. Bending or punching processing information relating to a punch shape created by a CAD system and a stage on which each punch shape is arranged are set and stored in advance in a storage device of the CAD system. Based on the arrangement order, the feed direction of the material, the punch shape arranged on each stage and the processing information, the microprocessor of the CAD system accumulates the processed shape of each stage to the next stage and A product creation simulation method in a CAD system for progressive die, which is characterized in that the machining shape is graphically displayed.