JP2002373187A - Product designing device by computer support - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a product designing device (CAD/CAM) by computer support capable of preparing a fillet prior to draft preparation for dies cutting, and continuing the design of a product while confirming or grasping the function of the product in a state that the fillet is added. SOLUTION: Basic elements constituting a product model are prepared (S10), and a fillet or the like is prepared for the prepared basic elements (S12). Then, a Boolean arithmetic operation is performed (S14), and the fillet or the like is prepared again for the shape obtained as the result of the arithmetic operation (S16), and a draft is prepared (S18).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a computer aided product design apparatus, so-called CAD (Computer Aided).
Design) / CAM (Computer Aided Manufacturing),
Or CIM (Computer Integrated Manufacturin)
g) and other product design equipment.

[0002]

2. Description of the Related Art As an example of this kind of computer assisted product design apparatus, there is a technique described in Japanese Patent Application Laid-Open No. 9-319772. In the prior art, a feature point of a product shape is determined in a product design process in a preceding process, thereby enabling an automatic design of an upper mold shape in a die design process in a subsequent process. It is proposed to shorten.

As described above, CAD / CAM or CI
In M, when a product is to be manufactured using a mold, a designer usually first creates (designs) a product model (product shape) in a product design process using a CAD system.
A mold model is created (designed) in a mold design process using the created product model.

[0004] Next, mold processing data is created by using the created mold model, and a mold is manufactured by NC processing or the like using the data, and casting / molding is performed using the manufactured mold. Manufacture products by cutting.

As described above, since the shape of the product model created in the product design process becomes the shape of the product as it is, the draft required in the casting process, that is, the draft for extracting the product from the die is determined by the product. It must be added (created) to the product model in the design process.

[0006] In the product model, a rounded shape called a fillet is created at a ridge line (edge) having corners.
That is, the product model is corrected so that the portion where two line segments or curves intersect smoothly with an arc having the specified radius of curvature.

Conventionally, in a CAD / CAM or CIM product design process, a draft is first created in a product model, and then a fillet is created. This focuses on one edge (ridge line) in the model, where the above-mentioned edge line or the like of the product model is generally called a winged edge, and describes the relationship between edges and vertices including the left and right surfaces thereof. The shape is expressed, and when a fillet is given, the edge disappears.

[0008]

The fillet is provided (created) with the intention of avoiding stress concentration of the product (and the mold) and improving the appearance. However, it is difficult for designers to provide a fillet at the initial stage of the product design process and to continue the design while confirming or grasping the function of the product based on the product model (product shape) with the fillet added. desirable.

Further, when a product has a complicated shape in which concavo-convex portions (basic elements) such as a transmission case of an automobile are continuous, a draft is given (created) for each basic element, and the draft is given. Judge whether it is enough to extract the product and after it is judged that it is enough,
The work of applying fillets must be repeated.

[0010] In this case, when the draft once given is changed for some reason, the basic element is corrected and then the draft is corrected, so that there is a disadvantage that the operation becomes complicated.

Further, conventional CAD / CAM or C
In the IM product design process, when a draft or fillet is to be created for one of the basic elements, the basic elements are configured to be automatically selected (specified) in a lump. In order to select the partial region from the die-cut surface and the die-cutting direction, the process of specifying the region must be performed manually, and it is not always satisfactory in the degree of freedom of design.

Accordingly, an object of the present invention is to solve the above-mentioned problems, to provide a fillet in an initial stage prior to drafting in a product design process, and to provide a fillet based product model (product shape). It is an object of the present invention to provide a computer-assisted product design apparatus capable of confirming or grasping the function of a product and continuing the design.

It is a second object of the present invention to provide a computer-assisted product design apparatus which makes the operation relatively easy even if the draft once given is changed for some reason. .

A third object of the present invention is to provide a computer-assisted product design apparatus capable of automatically creating a fillet or draft by designating a partial area of each uneven portion (basic element). Is to provide.

[0015]

In order to solve the above-mentioned object, according to the present invention, there is provided a computer, a display connected to the computer and displaying an output thereof, and a storage in the computer. And at least a design support program for realizing a shape modeling function using a three-dimensional curve and a three-dimensional surface via an output on the display, wherein the design support program models the product using the modeling function. A product design process for designing a model, and at least a mold design process for designing a mold for manufacturing the product using the designed product model; Is a basic element creation program for creating basic elements constituting the product model. Means, a fillet creating means for creating a fillet in the created basic element, and a punch for extracting the product from the mold designed in the mold designing step, created in the basic element in which the fillet is created. The apparatus is configured to include at least a draft determination unit that determines whether the gradient is sufficient to extract the product.

Create the basic elements that make up the product model,
A fillet is created for the created basic element, and it is configured to determine whether the draft created for the basic element for which the fillet has been created is sufficient, so that the function of the product is based on the product model with the fillet added. The design can be continued while confirming or grasping, and the operation becomes relatively simple when the draft once given is changed for some reason.

According to a second aspect of the present invention, the draft judging means includes a draft creating means for creating the draft on the basic element in which the fillet is created.

More specifically, since the draft is formed in the basic element in which the fillet is created, the design is confirmed while checking or grasping the function of the product based on the product model with the fillet. The operation can be continued, and the operation becomes relatively simple even when the draft once given is changed for some reason.

According to a third aspect of the present invention, the draft creating means is configured to temporarily erase the created fillet to create the draft, and then to restore the temporarily erased fillet.

That is, since the formed fillet is temporarily erased to create a draft and then the temporarily erased fillet is restored, the function of the product is confirmed or confirmed based on the product model with the fillet added. The design can be continued while grasping, and the operation becomes relatively simple even when the draft once given is changed for some reason.

According to a fourth aspect of the present invention, the draft creating means partially designates a region of the basic element from a die-cutting surface of the die and a die-cutting direction, and in the designated region, It was configured to create a gradient.

Since the area of the basic element is partially specified from the die-cutting surface of the mold and the die-cutting direction and the draft is created in the specified area, the above-described effects are obtained.
The degree of freedom in design can be improved.

According to a fifth aspect of the present invention, the draft creating means creates the draft in an area other than the fillet creation surface where the fillet was created, and the created draft removes the product. When it is determined that the surface is sufficient to be drawn, the fillet forming surface is added to the draft forming surface.

A draft is created in an area other than the fillet creation plane where the fillet was created, and when the created draft is judged to be sufficient, the fillet creation plane is added to the draft creation plane. The design can be continued while confirming or grasping the function of the product based on the product model with the fillet attached, and the work is relatively simple when changing the draft once given for some reason. Become.

According to a sixth aspect of the present invention, the draft creation means sets at least one of the area and the fillet creation surface on which the fillet is created as a slope reference, and based on the set slope reference. It was configured to create the draft angle.

Since at least one of the area and the fillet forming surface on which the fillet has been formed is set as the gradient reference, and the draft is formed based on the set gradient reference, the design is free in addition to the above-described effects. The degree can be improved.

According to a seventh aspect of the present invention, the fillet is a fillet having a constant radius of curvature.

Since the fillet is constituted as a fillet having a constant radius of curvature, the same effect as described above can be achieved.

In a preferred embodiment, the fillet is a gradually changing fillet having an indeterminate radius of curvature.

Since the fillet is a gradually changing fillet having an indefinite radius of curvature, the degree of freedom in design can be improved in addition to the above-described effects.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A computer assisted product design apparatus according to one embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic diagram showing the entire computer assisted product design apparatus. Symbol 1 in the figure
0 indicates the device, device 10 is the computer 12,
It has a display 14 connected to the computer 12 for displaying its output, and is connected to the computer 10 via an output stored on the computer 10 and displayed on the display 14.
An interactive program 16 is provided for design support for realizing a shape modeling function using a three-dimensional curved surface and a three-dimensional curved surface.

Further, the device 10 is provided with an input device 18 such as a keyboard and a mouse.
Inputs data through the input device 18 based on a design specification describing required product specifications, and interactively designs a product model in accordance with instructions stored in the program 16.

In the program 16, the product is expressed as numerical data such as vertices and edges (edges) of the shape.
Specifically, the shape modeling of the product is represented by a solid model. Specifically, the designer sweeps a basic figure (primitive) such as a cylinder displayed on the display 14 and, at the same time, performs a Boolean operation (set operation) composed of a union, a difference and an intersection.
To design the product model 20.

As described above, the device 10 is configured as a CAD / CAM or a CIM.

FIG. 2 is an explanatory diagram showing steps from product design to mass production, which are performed using the apparatus 10.

As described above, when explaining again, CAD
In / CAM or CIM, when manufacturing a product 26 using the mold 24, the designer usually first creates (designs) the product model 20 in the product design process using the device 10, Using the created product model 20, a mold model 28 is created (designed) in a mold design process.

Next, the designer sets the created mold model 2
8 is used to create mold processing data, the data is used to produce a mold 24 by an NC machining apparatus 30 or the like, and the manufactured mold 24 is used to produce a product 26 by casting and cutting. I do.

As described above, since the shape of the product model created in the product design process becomes the shape of the product as it is, the draft required in the casting process, that is, the draft for extracting the product from the mold is determined by the product. It must be added (created) to the product model in the design process.

FIG. 3 is an explanatory diagram of die cutting. Mold 24
A material 26 is poured into a space defined by an upper mold (core) 24a and a lower mold (cavity) 24b to obtain a desired product 26.
To manufacture. At this time, a draft is created to facilitate the removal of the product 26 from the mold.

FIG. 3 shows a simplified view of the product 26.
Actually has a complicated uneven shape as shown in FIG.
In the case of the illustrated example, the case is a transmission case, and in such a case, the shape of the mold is complicated, and the number of mold removal directions is increased.

FIG. 5 is a flowchart showing the operation of the apparatus 10.

In the following, basic elements are created (designed) in S10. The basic elements are, for example, in the example of FIG.
Refers to one or more irregularities on the transmission case. Next, the process proceeds to S12, where the fillet
t) and the like, that is, a fillet, smoothing, trim, etc. are created, and then the process proceeds to S14 to perform the above-described Boolean operation. Go ahead and create a draft.

The process of S18 also includes an operation of determining whether the draft angle created is sufficient to extract the product 26 (more precisely, the product model 20). Next, the process proceeds to S20, where correction of the minimum fillet and the like is performed as necessary.

FIG. 17 is a flow chart showing the processing according to the prior art. In the prior art, as shown in the drawing, a draft is created after the basic element is created, and a fillet or the like is created after that. .

However, as described above, it is desirable for a designer to provide a fillet at an early stage of a product design process, and to confirm or grasp the function of a product based on the product model 20 with the fillet provided. Also, if the draft is created first, if the draft once applied is changed for some reason, the irregularities (basic elements) will be corrected, and then the draft will be corrected. was there. Therefore, in this embodiment, a fillet or the like is created first.

Hereinafter, the processing of FIG. 5 will be described with reference to FIG.

As shown in the upper left part of the figure, first, a basic element 100 of a product model 20 formed by combining two cylinders (primitives) is created, and then a fillet 102 is created on a side mating surface of the basic element 100. I do. Illustration of smoothing and trim is omitted for simplification of description. Next, the draft 104 is created, and it is determined whether the draft 104 created is sufficient.

It should be noted that the work of the designer regarding the draft creation and determination processing is only the designation of the location to be created (specifically, the location to be created, the die-cutting surface, the die-cutting direction and the gradient angle) and the determination point. The processing is automatically performed by the computer 12 according to the determination processing described in advance in the program 16. The same applies to the creation of the fillet 102, in which the designer merely specifies the location and radius of curvature, and the computer 12 automatically performs the subsequent fillet creation work itself. The same applies to Boolean operations and the like.

However, if the fillet 102 is created first, the edge 106 disappears. On the other hand, since the automatic processing of the program 16 is based on the premise that the shape is represented by edges, it is impossible to determine the draft by the automatic processing. Therefore, in each case, the input device 1
The user manually designates a determination point or the like via the interface 8, and the processing becomes troublesome.

Therefore, in this embodiment, in consideration of this point, the created fillet 102 is temporarily erased when the above-mentioned instruction such as the draft creation position and the determination instruction are given. Specifically, the program 16 is created so that the fillet is temporarily erased by giving a fillet temporary erasure instruction, and the computer 12 automatically processes the program.

That is, as shown in FIGS. 6 and 7, even when the fillet 102 is created, the fillet 102 is temporarily erased and the edge 106 is restored to create a draft, and the created draft is sufficient. It is made to determine whether or not. For example, in FIG. 7, the side surface 100a is determined to have insufficient gradient. Then, a draft (surface) 104 is created, and after it is determined that the created gradient is sufficient, the fillet 102 is restored.

Thus, the designer gives the fillet 102 in the initial stage of the product design process, and confirms or grasps the function of the basic element 100 based on the product model 20 to which the fillet 102 has been attached, and performs the design. You can continue. Furthermore, this makes the draft correction work easier than in the prior art.

FIG. 8 is a flowchart showing a draft correction operation.
FIG. 18 is a flow chart showing a similar process in the prior art.

In the prior art shown in FIG. 18, the basic elements are modified, then the draft is modified, then recalculated,
That is, it is necessary to repeat the Boolean operation again and partially correct the fillet and the like based on the result, and the operation is complicated. In particular, it is necessary to reset the parameters in the Boolean operation, which is troublesome.

On the other hand, in the processing according to this embodiment, as shown in FIG. 8, it is sufficient to delete the draft in S100, and proceed to S102 to newly create a draft, which simplifies the work. Become.

Further, a feature of this embodiment is that a partial area of a basic element can be designated on a mold surface or the like. More specifically, the program 16 has been rewritten so that a partial area of a basic element can be specified on a mold surface or the like.

That is, in the prior art, as shown in the upper part of FIG. 19, when the side surface 100a of the basic element 100 on which the fillet 102 was created was specified, the shape was represented by the edge 106. The entire side surface 100a was selected, including the surface on which the fillet 102 was created because it was continuous.

As shown in the lower part of FIG.
When the fillet 102 is created between a and the end 100b, the edge 106 disappears due to the fillet 102, so that the entire basic element 100 is selected as shown in the lower right of FIG.

Further, in the prior art, as shown in FIG. 20, a partial area cannot be designated on a mold surface or the like. Had become. Therefore, in order to select a partial region from the die-cut surface, the die-cutting direction, and the like, there is an inconvenience that the operation of specifying the region must be performed.

Therefore, in this embodiment, FIG.
As shown in FIG.
(In the illustrated example, the upper half 10 of the side surface 100a)
0c) can be specified. In other words, the program 16 is created so that the computer 12 can automatically process the program so that a partial area of the basic element can be designated from the die-cut surface and the die-cutting direction.

Further, a feature of this embodiment is that a gradient reference plane can be set at an arbitrary position, and a gradient is created according to the position. In other words,
The program 16 was created so that the gradient reference plane could be set at an arbitrary position, and the gradient was created in accordance therewith, and the computer 12 automatically processed the program. Here, the “gradient reference plane” is a base point of the draft, and refers to a surface whose shape does not change even when the draft is created.

FIGS. 10A, 10B, and 10C show the basic element 10
0 is a partial cross-sectional view, but as shown in the figure, a gradient reference plane can be set at an arbitrary position. FIG. 7A shows a gradient creation area, and FIGS. 7B and 7C show gradient faces created based on a designated slope reference plane.

It should be noted that the draft is created in FIG. 9, and when the created draft is determined to be sufficient, the fillet 102 is restored as described above.
Note that the fillet 102 is a fillet having a constant radius of curvature.

As described above, the computer-aided product design apparatus according to the first embodiment is constructed so that the created fillet 102 is temporarily erased to create a draft, and then the temporarily erased fillet 102 is restored. Therefore, the product model 2 with the fillet 102 attached
The design can be continued while confirming or grasping the function of the product 26 based on 0, and the operation becomes relatively simple even when the once-applied draft is changed for some reason.

Also, since the area of the basic element 100 is partially specified from the die-cutting surface of the mold 24 and the die-cutting direction, and the draft is created in the specified area, the design effect is obtained in addition to the above-mentioned effects. Degree of freedom can be improved.

FIG. 11 is an explanatory diagram similar to FIG. 9, showing the operation of the device according to the second embodiment of the present invention.

In the second embodiment, drafting and gradient determination are performed ignoring the surface on which the fillet 102 is formed. The fillet 102 is automatically added to the created gradient surface. The remaining configuration is the same as in the first embodiment.

As described above, the computer-assisted product design apparatus according to the second embodiment is constructed such that the fillet 102 is added after the draft (surface) 104 is created ignoring the created fillet 102. The design can be continued while confirming or grasping the function of the product 26 based on the product model 20 to which the fillet 102 has been provided, and the work can be continued even when the draft once given is changed from some circumstances. Relatively simple.

FIG. 12 is an explanatory diagram similar to FIG. 9, showing the operation of the device according to the third embodiment of the present invention.

In the device according to the third embodiment,
The face on which the fillet 102 was created can be selected as a draft creation area. However, fillet 102
Is created, the edge 106 disappears on the side surface. Therefore, as shown in the figure, when the fillet creation surface is selected, the side surface including the fillet creation surface is selected over the entire circumference.

The remaining structure and effects are the same as in the first embodiment.

FIG. 13 is an explanatory diagram similar to FIG. 9, showing the operation of the device according to the fourth embodiment of the present invention.

In the device according to the fourth embodiment,
The surface on which the fillet 102 is created can be used as a gradient reference surface. In other words, the fillet 102
A program 16 is created so that the surface on which is created can be used as a gradient reference surface, and the computer 12 automatically processes it.

FIGS. 14 (a), 14 (b) and 14 (c) are partial cross-sectional views of the basic element 100 showing a tangentially continuous inclined surface on the fillet 102 produced thereby.

By configuring as above, fillet 1
It is possible to automatically create a gradient surface that is tangent to 02. The remaining configuration is the same as in the first embodiment.

With the structure according to the fourth embodiment, the degree of freedom in design can be improved in addition to the effects of the previous embodiment.

FIG. 15 is an explanatory diagram similar to FIG. 9, showing the operation of the device according to the fifth embodiment of the present invention.

In the device according to the fifth embodiment,
The gradient can be determined through the die-cutting surface including the surface on which the fillet 102 is formed, the die-cutting direction, and the gradient angle.
The device according to the fifth embodiment is a modification of the devices according to the third and fourth embodiments, and has the same effect. The remaining configuration is the same as in the first embodiment.

FIG. 16 is an explanatory diagram similar to FIG. 9, showing the operation of the device according to the sixth embodiment of the present invention.

In the device according to the sixth embodiment,
The fillet 102 was a gradually changing fillet having an indeterminate radius of curvature. That is, the program 16 is created by the computer 12 so that the fillet 102 having a constant radius of curvature as shown in the upper left of the figure can be changed to a gradually changing fillet having an indeterminate radius of curvature as shown in the upper right of the figure. Automatic processing.

Since the device according to the sixth embodiment is configured as described above, in addition to the effects described in the previous embodiment,
Any gradually changing fillet 102 can be automatically created, thereby further improving the design flexibility.

In this embodiment, a computer 12, a display 14 connected to the computer and displaying its output, and a three-dimensional curve and 3D stored in the computer and output through the display are displayed.
At least a design support program 16 for realizing a shape modeling function using a three-dimensional curved surface is provided.
A computer-assisted product design apparatus including at least a product design step of designing a product model 20 that models a product, and a mold design step of designing a mold for manufacturing the product using the designed product model. 10, the program of the product design process includes a basic element creating means (S10) for creating a basic element 100 constituting the product model, a fillet creating means (S12) for creating a fillet 102 on the created basic element, And the fillet is created on the created basic element,
The apparatus is configured to include at least a draft determining unit (S18) for determining whether or not the draft 104 for extracting the product from the die designed in the die designing step is sufficient to extract the product.

Further, the draft determination means is configured to include draft creation means (S18) for creating the draft 104 in the basic element in which the fillet has been created.

The draft creating means is configured to temporarily erase the created fillet 102 to create the draft, and then to recover the temporarily erased fillet 102.

The draft creating means partially designates the area of the basic element 100 from the die-cut surface of the mold 24 and the die-cutting direction, and creates the draft in the designated area. Configured.

The draft creating means creates the draft in an area other than the fillet creation surface where the fillet 102 was created, and determines that the created draft is sufficient to extract the product. Then, the fillet forming surface is added to the draft forming surface.

The draft creating means sets at least one of the region and the fillet creation surface on which the fillet 102 is created as a gradient reference, and creates the draft based on the set gradient reference. It was configured as follows.

The fillet is configured to be a fillet having a constant radius of curvature.

Further, the fillet is configured to be a gradually changing fillet having an indeterminate radius of curvature.

[0091]

According to the first aspect of the present invention, a basic element constituting a product model is created, a fillet is created for the created basic element, and a draft angle created for the basic element for which the fillet is created is sufficient. Since it is configured so as to determine whether or not the design can be continued while confirming or grasping the function of the product based on the product model in the state where the fillet is provided, the draft once given is changed from some circumstances. In this case, the operation is relatively simple.

In the second aspect, more specifically,
Since the draft is configured to create the basic element where the fillet is created, it is possible to continue the design while confirming or grasping the function of the product based on the product model with the fillet added, and once Even when the draft angle is changed for some reason, the operation becomes relatively simple.

According to the third aspect of the present invention, the created fillet is temporarily erased to create a draft, and then the temporarily erased fillet is restored, so that the fillet is provided on the basis of the product model. The design can be continued while confirming or grasping the function of the product, and the operation becomes relatively simple even when the draft once given is changed for some reason.

According to the fourth aspect of the present invention, the basic element region is partially specified from the die-cutting surface of the mold and the die-cutting direction, and a draft is created in the specified region. In addition to the effects, the degree of freedom in design can be improved.

According to a fifth aspect of the present invention, a draft is created in an area other than a fillet creation surface where a fillet is created, and when it is determined that the created draft is sufficient, a fillet is created on the draft creation surface. Since the surface is configured to be added, the design can be continued while confirming or grasping the function of the product based on the product model in which the fillet is provided, and the draft once given is changed from some circumstances. In this case, the operation is relatively simple.

According to the present invention, at least one of the area and the fillet creation surface on which the fillet is created is set as a gradient reference, and the draft is created based on the set gradient reference. In addition to the effects described above, the degree of freedom in design can be improved.

In the present invention, since the fillet is configured to be a fillet having a constant radius of curvature, the same effect as described above can be achieved.

According to the eighth aspect, the fillet is configured to be a gradually changing fillet having an indefinite radius of curvature, so that the degree of freedom in design can be improved in addition to the above-described effects.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram generally showing a computer-assisted product design apparatus according to one embodiment of the present invention.

FIG. 2 is an explanatory view showing steps from product design to mass production, which are performed using the apparatus of FIG. 1;

FIG. 3 is an explanatory diagram of die removal for removing a product from the die of FIG. 2;

FIG. 4 is an explanatory perspective view showing a specific example of a product to be manufactured by the apparatus of FIG. 1;

FIG. 5 is a flowchart showing the operation of the apparatus of FIG. 1;

FIG. 6 is an explanatory diagram specifically showing an operation of the apparatus of FIG. 1, which is a process of the flowchart of FIG. 5;

7 is an explanatory diagram specifically showing the operation of the apparatus of FIG. 1, which is the processing of the flowchart of FIG. 5;

FIG. 8 is a flowchart showing the processing when the draft is changed in the processing of the flowchart of FIG. 5;

9 is an explanatory diagram specifically showing the operation of the apparatus of FIG. 1, which is the processing of the flow chart of FIG. 5;

FIG. 10 is a partial sectional view of the basic element shown in FIG. 9;

FIG. 11 is an explanatory diagram similar to FIG. 9, illustrating the operation of the computer-aided product design apparatus according to the second embodiment of the present invention;

FIG. 12 is an explanatory diagram similar to FIG. 9, illustrating an operation of a computer-assisted product design apparatus according to a third embodiment of the present invention.

FIG. 13 is an explanatory diagram similar to FIG. 9, illustrating the operation of the computer-aided product design apparatus according to the fourth embodiment of the present invention.

14 is a partial sectional view of the basic element shown in FIG.

FIG. 15 is an explanatory diagram similar to FIG. 9, illustrating an operation of a computer-assisted product design apparatus according to a fifth embodiment of the present invention.

FIG. 16 is an explanatory diagram similar to FIG. 9, illustrating an operation of a computer-assisted product design apparatus according to a sixth embodiment of the present invention.

FIG. 17 is a flow chart similar to FIG. 5, showing the operation of the device according to the prior art.

FIG. 18 is a flowchart showing a process when the draft is changed in the process of the flowchart of FIG. 17;

FIG. 19 is an explanatory diagram similar to FIG. 9, showing the operation of the device according to the prior art.

FIG. 20 likewise shows the operation of the device according to the prior art;
It is explanatory drawing similar to FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Computer-assisted product design apparatus 12 Computer 14 Display 16 Program 18 Input device 20 Product model 24 Die 26 Product 100 Basic element 102 Fillet 104 Draft (surface) 106 Edge

Claims (8)

[Claims] 1. A computer, a display connected to the computer and displaying an output thereof, and a design stored in the computer and realizing a shape modeling function by a three-dimensional curve and a three-dimensional surface via the output on the display. At least a support program, wherein the design support program comprises: a. A product design process of designing a product model obtained by modeling a product using the modeling function; and b. A mold design step of designing a mold for manufacturing the product using the designed product model, including at least, a computer-aided product design apparatus,
A program for the product design process, c. Basic element creating means for creating basic elements constituting the product model; d. Fillet creating means for creating a fillet in the created basic element; and e. Draft angle determination for determining whether or not the draft angle for extracting the product from the mold designed in the mold design process, which is created on the basic element where the fillet is created, is sufficient to extract the product. Means for computer-assisted product design. 2. The apparatus according to claim 1, wherein the draft determining means includes: f. 2. The computer-aided product design apparatus according to claim 1, further comprising draft drafting means for drafting said draft in said basic element in which said fillet has been drafted. 3. The computer according to claim 2, wherein the draft creating means creates the draft by temporarily deleting the created fillet, and then recovers the temporarily deleted fillet. Product design equipment with support. 4. The draft creating means, wherein a region of the basic element is partially specified from a die-cutting surface of the mold and a die-cutting direction, and the draft is created in the specified region. The computer-aided product design apparatus according to claim 2. 5. The draft creating means creates the draft in an area other than the fillet creation surface where the fillet was created, and determines that the created draft is sufficient to extract the product. 5. The computer-assisted product design apparatus according to claim 4, wherein said fillet creation plane is added to said draft creation plane. 6. The draft creating means sets at least one of the area and the fillet creation surface on which the fillet was created as a gradient reference, and creates the draft based on the set gradient reference. The computer-aided product design apparatus according to claim 4 or 5, wherein: 7. The computer-assisted product design apparatus according to claim 1, wherein the fillet is a fillet having a constant radius of curvature. 8. The computer-aided product design apparatus according to claim 1, wherein said fillet is a gradually changing fillet having an indeterminate radius of curvature.