JPH11147226A - Method for evaluating configuration of product for die design - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for evaluating a die configuration to design a die wherein a male die and a female die can be efficiently produced and the time required to feed a product can be made shorter. SOLUTION: A release direction of a die is taken as a Z-axis and constituent surfaces of a three-dimensional product model 10 are classified into a surface A wherein all components Z of a normal vector become plus, a surface B wherein all components become minus, a surface C wherein all components become zero, and a surface D wherein pluses coexist with minuses, and further the surface C is classified into a surface C-A, a surface C-B, and a surface C-O, and an undercut part is taken as a surface E to evaluate each of the constituent surfaces of the model 10. And by classifying each surface to be evaluated by coloring, barrier surfaces of a die can be obtained so that male dies and female dies can be easily produced. If the configuration of a product is evaluated in an initial stage of design, a three-dimensional product model can be easily produced without correcting the configuration in a mass-production stage so that the time required to feed a product can be shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for evaluating a product shape for designing a mold, and more particularly, to a method for evaluating a product shape.
CAD, CAM, CG (computer graphics)
The present invention relates to a method for evaluating a product shape in consideration of mass production when designing a mold for a three-dimensional product using a computer-aided design device such as a system.

[0002]

2. Description of the Related Art With the spread of computer-aided design equipment having a three-dimensional solid modeling function, a three-dimensional solid model is created in a product design process, and the probability of a production process that effectively utilizes the three-dimensional solid model is a problem. Has become. In particular, injection-molded products are becoming more complicated with the progress of technology, and it is difficult to study details in a conventional two-dimensional design mainly based on drawings, which may cause design defects. Expectations are growing.

Conventionally, a mold design function using a computer-aided design device has been mainly created for two-dimensional design.
Several methods for improving the efficiency of mold design are also provided, but all are based on 2D design, and even with advanced 3D design of products, they have a 3D solid modeling function. In a computer-aided design apparatus, a method of designing a mold in accordance with characteristics generally possessed by the apparatus has not been provided.

[0004]

Particularly, in a three-dimensional design, basically, a model created by a designer is utilized as much as possible without re-inputting a model shape.
It will produce a greater effect. However, when the product model creator and the mold designer are different, a lot of time has been spent on determining whether or not the product model is suitable for the mold design before starting the work.

For mass production of products, dies for plastic injection molding, aluminum die casting and the like are used in many cases. Since these molds are used, it is a major problem whether or not a draft angle considering the releasability is added.

For example, in FIG. 7A, when a product 10 having an H-shaped cross section is formed by a mold 11 composed of an upper mold 12 and a lower mold 13, the vertical surfaces 16 at both ends are drawn in the drawing direction. A major problem is whether or not a draft angle θ considering the releasability is added to a certain vertical line 18.

[0007] Further, as shown in FIG.
When the contact / separation surface between the mold 2 and the lower mold 13 is in the middle of the vertical surface 16 at both ends, the draft angle θ considering the releasability on both the upper and lower surfaces of the contact / separation surface with respect to the vertical line 18. Must be added. Further, as shown in FIG. 7C, in the product 10 having the lateral hole and the other lateral concave portion 17,
Since there is a part that cannot be released simply by opening and closing the upper die 12 and the lower die 13 alone, the punching die 1 called a slide mechanism that slides in directions other than up and down to release the die.
4 must also be combined to form the mold 11.

The draft angle θ considering the releasability and the location of the lateral recess 17 can be reliably found, the location which becomes defective in the production of the die can be corrected in advance, and the draft direction of the die 11 can be corrected. Being able to study is extremely important in increasing the efficiency of mold design and reducing rework due to mold defects. However, a conventional method of inspecting a three-dimensional product shape model using a computer-aided design device such as a CAD, CAM, or CG (computer graphic) system is to verify each surface constituting the model or to determine a draft angle θ. Only a low-level evaluation method that verifies the presence or absence of addition has been provided. Therefore, the operator has to spend a lot of time evaluating the product shape.

Further, even when a three-dimensional design in consideration of mass production is performed from the initial stage of product design, there is no way to inspect whether the draft angle θ has been completely added, and the price of the mold is reduced. Slide mechanism 1 that has a large effect
In order to optimize the design, such as reducing the number of items, it was necessary to provide inspection means.

It is an object of the present invention to provide a method of evaluating a product shape, especially in consideration of a mold design using a three-dimensional model. It also aims to provide usage. According to the method of the present invention, a solid model or a surface model can be applied to any of three-dimensional models. However, in the case of the surface model, since the vector direction is not adjusted, the vector direction of the surface used for determining the inside / outside of the shape is adjusted in advance or is applied by inserting a process for adjustment first. It is.

[0011]

According to the present invention, when the three-dimensional product model 10 is formed by a mold, the mold release direction is set to the Z axis of the coordinates, and the three-dimensional product model 10 A surface normal is sampled, and a surface (type A) in which the Z component of the normal vector is all positive
Surface), a surface in which all the Z components of the normal vector are negative (type B surface), a surface in which all the Z components of the normal vector are zero (type C surface), and positive and negative Z components of the normal vector. Sorting into mixed surfaces (Type D surface)
This is a method of evaluating a product shape for mold design, which is characterized by evaluating each constituent surface of the three-dimensional product model 10.

For the type C surface, the type of the surface adjacent to the type C surface is evaluated, and the type A surface (type C-A surface) and the type B surface (type C-A surface) are evaluated. This is a method for evaluating a product shape for mold design in which the surface is classified into a surface (CB surface) and other surfaces (type C-0 surface).

With the above-described evaluation method, it is possible to improve the efficiency of the evaluation of the product shape and the next step, ie, the work of preparing the male mold and the female mold, which are performed in the mold design. Further, it is possible to eliminate a mistake of manufacturing a mold by using inconsistent data.

Further, if the evaluation of the product shape is performed from the initial stage of design, a three-dimensional product model which does not need to be modified in the mass production process can be easily created, and the time until product introduction can be shortened.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method of evaluating a product shape for designing a mold according to the present invention to achieve the above-mentioned object is shown in FIGS.
This will be described with reference to the flowchart of FIG. Product model 10
As an example, consider a three-dimensional article as shown in FIG. FIG. 1A is a front view, and only the evaluation method for the plane, bottom, and both sides of the component surface viewed from the front will be described. I omit the back and front,
It can be evaluated by similar processing.

FIG. 2 shows that the constituent surfaces of the product model 10 are classified into four types, A, B, C, and D, and the type of the surface adjacent to the type C surface is evaluated.
It is a flowchart which sorts into each of A, CB, and C-0. In the flowchart of FIG. 2, after the start, parameters used for evaluation are input. The parameters include a draft angle θ, a drawing direction (for example, the Z axis of the working coordinates as a mold release direction), an instruction of a surface to be evaluated, and an instruction of a result display method after evaluation (color classification, line type classification). And the like, and these are input from the input unit 32 in FIG.
The data is input to the memory 31 via U30.

Next, sampling of the surface normal is performed. Sampling condition settings are, for example, as follows. Processing target conditions ◆ Absolute value of gradient angle ◇ Gradient 3 degrees 1/100 state color ■ Cavity side CYAN ■ Core side GREEN WARNING ■ Undercut part YELLOW ■ Undercut part ORANGE ■ Specified gradient angle insufficient cavity side RED ■ Specified Insufficient gradient angle PINK ■ Gradient unprocessed MAGENTA ■ Gradient unprocessed (cavity side) MAGCAV ■ Gradient unprocessed (core side) MAGCOR ■ Gradient determination not possible WHITE Removal direction 0 (X), 0 (Y), 1 (Z) Vector specification ■ Perform detailed undercut check ■ Color-coded unprocessed surface as cavity side / core side

By sampling the surface normal,
Focusing on the Z component of the normal vector, that is, the Z component of the normal vector on the component surface of the three-dimensional product model 10 as viewed from the Z axis of the work coordinates, classification is performed into the following four types. For example,
The configuration surface of the three-dimensional product model 10 in FIG.
f1 to f16 (Z of three-dimensional front and back normal vectors)
Assuming that the components are not shown), these normal vectors are represented by arrows perpendicular to each surface, and are classified as follows.

Type A surface: If the Z component of the sampled normal vector is a positive surface, then in the case of FIG. 1A, f1, f2, f3, f4, f
5, f14 is the type A surface. Type B surface: Assuming a surface in which all the Z components of the sampled normal vector are negative, FIG.
In the case of (a), f9, f10, f11, f12, f1
3, f16 is the type B surface. Type C plane: Assuming a plane in which the Z component of the sampled normal vector is all zero, f6, f8, and f15 are type C planes in the case of FIG. Type D plane: Assuming that the Z component of the sampled normal vector is a plane in which plus and minus coexist, f7 is the type D plane in FIG. 1A. In the above sampling, an arbitrary point on the surface and a sufficient sampling point on the surface boundary line are set so that a sufficient evaluation can be performed. The result of the evaluation is input to the input unit 32 in FIG.
And is stored in the memory 31 via the CPU 30.

At the same time as sorting into four types, marking is performed on both sides A and B, with a portion having a position less than a given required gradient angle θ. That is, the gradient angle θ considered necessary for the mold release is instructed in advance, and at the same time as this evaluation, it is evaluated whether or not a portion having the gradient angle or less exists in the evaluated surface. As a result, it becomes clear that all the surfaces having a portion equal to or smaller than the designated gradient angle need to be corrected for mass production. In the case of FIG. 1A, it is assumed that f2 and f4 on the surface A and f10 and f12 on the surface B are less than the required gradient angle. This result is also input from the input unit 32 in FIG.
The data is stored in the memory 31 via U30.

Type C surface (surface where all normal Z components are 0)
Evaluate the type of adjacent surface. In the case of a type C plane in which all the Z components of the normal vector are 0, this C plane is a type C-0 plane: a boundary surface of the matching (for example, before the plane division, the C-A plane or the C-plane). -The surface in a state where it is unknown whether it is the B surface) Type CA surface and type CB surface: A surface that simply requires draft processing (for example, f6 in FIG.
f8 plane). To identify this, a more detailed evaluation is performed.

First, attention is paid to the evaluation result of the type of the surface adjacent to the type C surface. First, is Type C side adjacent to both Type A and Side B? Is determined. Y
In the case of ES, an attribute as a type C-0 plane is provided.

If NO, is the type C surface adjacent to the type A surface? Is determined. This judgment is YES
In the case of, the attribute as the type CA plane is added.
In other words, this indicates that the surface should originally belong to the type A surface, but no gradient is added. Such a surface is referred to as a type CA surface, and an attribute as the type CA surface, that is, a draft process is given. For example, assuming that the f6 surface in FIG. 1A is formed by the upper mold 12, the f6 surface is a type CA surface, and a draft process as the type CA surface is applied. .

Whether the type C surface is adjacent to the type A surface? Is NO, that is, if the surface adjacent to the type C surface is the type B surface, this indicates that the surface should originally belong to the type B surface, but no gradient is added. Such a surface is referred to as a type CB surface, and an attribute as the type CB surface, that is, a draft process is given. For example, assuming that the f8 surface in FIG. 1A is formed by the lower mold 13, the f8 surface is:
The type CB surface is set, and a draft process as the type CB surface is applied.

The evaluation of the type C plane is repeatedly performed because it cannot be completed once depending on how the plane is configured.

Next, it is evaluated whether or not the product 10 can be released only by opening the mold in the same vertical direction as the Z axis, that is, whether or not an undercut portion exists. In this evaluation, a method of verifying the overlap of the surfaces viewed from the pulling direction in a brute force manner is conceivable. However, when the number of the surfaces increases, an enormous amount of time is spent. For this reason, the present invention has devised a method capable of narrowing down a portion that can be a problem without performing a brute force and performing an inspection in a short time.

This is performed by combining the two judgment methods. The first method is a method of making a determination by grouping according to the surface type, and the second method is a method of determining whether or not surface offsets intersect. In the flowchart shown in FIG. 3, the case of the type A surface and the type CA surface which are the same group will be described. First, a method of grouping and determining according to the surface type of the first method will be described. It is checked whether the type A surface and the type CA surface are adjacent to the same type of surface, and as a result of grouping, if two or more groups exist, one of the groups is undercut. It is determined to be a copy, and is recognized as a type E surface.

For example, in FIG. 1A, as a result of checking f1, f2, f3, f4, f5, f6, and f14 in the same group, among them, f1, f2, f3, and f14 are checked.
4, f5 and f6 are one group adjacent to a surface of the same type, and f14 is another group that is not adjacent to this group. It is determined that a cut portion exists, and one of them, for example, f14, is recognized as a type E surface.

Next, a method of judging whether or not the offsets of the surfaces intersect in the second method will be described. Type A surface and type CA surface, type B surface and type C
At the point where the surface B is adjacent to a surface of a different type, if the adjacent surface has an intersection line as a result of the offset of the model shape, the surface cannot be removed from the vertical direction. It is a method of determining that the surface is a surface.

First, the surface A will be described with reference to the flowchart of FIG. 3. It is determined whether the surface adjacent to the type A surface or the CA surface is a different type. If NO, the process proceeds to the flowchart of FIG.
If YES, is the adjacent plane C-0? Is determined. If NO in this determination, does the offset of the planes intersect? Is determined. For example, in FIG. 1A, adjacent portions X1 and f14 of f1 (A) and f16 (B).
In the adjacent portion X2 of (A) and f13 (B), since there is no intersection line, it is determined that the surface is a surface that can be pulled out in the vertical direction. If YES (the adjacent plane is the C-0 plane), the adjacent B plane is searched. Then, after replacing the plane to be subjected to the offset intersection evaluation with the searched B plane, does the plane offset intersect? Is determined. When viewed from the pulling direction (Z direction), both sides A and B overlap, and
If plane B is located above plane A, is it an offset intersection plane? Becomes YES, and is recognized as the E side. For example, in FIG. 1 (a), it is determined that the adjacent portion X3 of f14 (A) and f15 (C-0) is a surface that cannot be pulled out from the up and down direction since there is an intersection line, and f14 ( A) The plane is recognized as the E plane. In the case of the product model 10 shown in FIG. 1B, f18 (C-0) is replaced with f17 (A),
f19 (A) and f20 (B) are adjacent, but f17
In the relationship between (A) and f20 (B), both sides A and B overlap, but since plane B is not located above plane A,
Offset intersection? Becomes NO, and f19
In the relationship between (A) and f20 (B), although the B surface is located above the A surface, since the A and B surfaces do not overlap,
Offset intersection? Is NO, and therefore is not recognized as the E surface.

Next, the same applies to the flowchart of FIG. For example, FIG.
F8, f9, f10, f11, f12, f13 at
Is a group adjacent to a surface of the same type,
Since f16 is another group that is not adjacent to the same type of surface, two groups exist, and it is determined that an undercut exists, and one of them, for example, f16 is changed to a type E surface. Recognize as

In determining whether or not the offsets intersect, for example, the adjacent portions X1 of f1 (A) and f16 (B), f14 (A) and f13 in FIG.
As described above, since there is no intersection line in the adjacent portion X2 in (B), it is determined that the surface is a surface that can be removed from the vertical direction. Since there is an intersecting line in the adjacent portion X3 between f16 (B) and f15 (C-0), it is determined that the surface cannot be removed from the vertical direction, and the f16 (B) surface is recognized as the E surface. .

As described above, by combining the first and second methods, the undercut portion can be specified without inspecting the entire model surface. With this method, the type E surface is determined. Finally, the type C surface that should originally belong to the type E surface is recognized as the type E surface in the same manner as described above. For example, in FIG.
The adjacent portion X3 between (A) and f15 (C-0) has an intersection, and the adjacent portion X3 between f16 (B) and f15 (C-0).
In the case of No. 3, the f15 (C-0) plane is recognized as the E plane because the intersection line exists.

As a result of the above evaluation, types A, B,
The separation of the C, D, and E surfaces and the separation of the type C-0, CA, and CB surfaces are performed on the type C surface. Based on such classification, the three-dimensional product model 10 is painted according to the color set for each type. Each color is, for example, cyan on the type A surface (cavity side) and green on the type B surface (core side) as specified by the above-described sampling condition setting in FIG. In addition, even for a surface where the gradient angle is insufficient, a warning color such as red or pink is used to distinguish which surface needs to be corrected. By performing the color coding in this manner, the visibility in the post-process is maintained, and the correction operation and the operation in the next process are easily performed.

In particular, in the next step, using the product model 10 represented by color coding, only the surface of a specific color is copied or deleted, thereby obtaining the boundary surface of the mold.
By adding a mating surface of the mold to the mold, a male mold and a female mold can be easily formed.

It is also easy to find the mold parting line. In other words, if attention is paid to the color change of the surface, since the boundary line of the portion where the surface of a specific color is adjacent becomes the type dividing line, by extracting this, the type dividing line can be easily formed, and , Can be found at high speed.

The present invention is effective not only for displaying the results by the surface color classification processing but also for storing and displaying the results as attribute information, highlighting the surfaces, and the like.

[0038]

According to the present invention, it is possible to improve the efficiency of the evaluation of the product shape and the next step in designing the mold, that is, the efficiency of the production work of the male mold and the female mold. Further, it is possible to eliminate a mistake of manufacturing a mold by using inconsistent data.

Further, if the evaluation of the product shape is performed from the initial design stage, a three-dimensional product model that does not need to be modified in the mass production process can be easily prepared, and the period until product introduction can be shortened.

Further, according to the method of the present invention, it can be applied not only to a solid model but also to a surface model or a three-dimensional model. However, in the case of a surface model, the vector direction of the surface used for determining the inside and outside of the shape is adjusted in advance, or it is necessary to insert a process for adjustment first.

By using the color-coded product model 10 to copy or delete only the surface of a specific color, it is possible to obtain the boundary surface of the mold. Thereby, male and female molds can be easily created.

Attention should be paid to a change in the color of the surface. Since the boundary line of the portion where the surface of a specific color is adjacent becomes the type dividing line, the type dividing line is extracted by extracting the type dividing line. It can be obtained easily and at high speed.

The present invention is effective not only for displaying a result by surface color classification processing, but also for holding and displaying the result as attribute information, highlighting the surface, and the like.

[Brief description of the drawings]

FIG. 1 shows a product model 10 for explaining the method of the present invention.
(A) is a front view of the first example, and (b) is
It is a perspective view of the 2nd example.

FIG. 2 shows the type of each component surface of the three-dimensional product model 10;
It is a flowchart for classifying into A-plane, B-plane, C-plane, and D-plane, and separating the C-plane into CA-plane, CB-plane, and C-0-plane.

FIG. 3 is an undercut portion (type E) as viewed from the A side.
9 is a flowchart for evaluating whether or not to recognize as (plane).

FIG. 4 is an undercut portion (type E) as viewed from the B side.
9 is a flowchart for evaluating whether or not to recognize as (plane).

FIG. 5 is an undercut portion (type E) as viewed from the C side.
9 is a flowchart for evaluating whether or not to recognize as (plane).

FIG. 6 is a block diagram of a control circuit for realizing the evaluation method according to the present invention.

FIG. 7 is an explanatory diagram for explaining a conventional problem.
(A) is a cross-sectional view when the product 10 is formed by a mold 11 composed of an upper mold 12 and a lower mold 13, and (b) is a contact and separation of the upper mold 12 and the lower mold 13. The face is a vertical face 16 at both ends.
(C) is a cross-sectional view when the product 10 having the lateral concave portion 17 is combined with the punching die 14 in addition to the upper die 12 and the lower die 13.

[Explanation of symbols]

10 ... product model, 11 ... mold, 12 ... upper mold, 13 ...
Lower mold, 14: Die mold, 16: Vertical surface, 17: Horizontal recess, 18: Vertical line, 30: CPU, 31: Memory, 32
... input part, 33 ... output part, 34 ... display part.

Claims (5)

[Claims] 1. When a three-dimensional product model 10 is created by a mold, the mold release direction is set to the Z axis of coordinates,
Sampling of the surface normal on each component surface of the three-dimensional product model 10 is performed, and the surface where all the Z components of the normal vector are positive (type A surface) and the surface where the Z component of the normal vector are all negative ( The three-dimensional product model is classified into a type B plane), a plane in which the Z component of the normal vector is all zero (type C plane), and a plane in which the Z component of the normal vector is a mixture of plus and minus (type D plane). 10. A method of evaluating a product shape for mold design, wherein each of the constituent surfaces of the product is evaluated. 2. When the three-dimensional product model 10 is created by a mold, the mold releasing direction is set to the Z axis of the coordinates,
Sampling of the surface normal on each component surface of the three-dimensional product model 10 is performed, and the surface where all the Z components of the normal vector are positive (type A surface) and the surface where the Z component of the normal vector are all negative ( The three-dimensional product model is classified into a type B plane), a plane in which the Z component of the normal vector is all zero (type C plane), and a plane in which the Z component of the normal vector is a mixture of plus and minus (type D plane). 10 and the type C surface is evaluated for the type of the surface adjacent to the type C surface, and the type A surface (type CA surface) and the type B surface A method for evaluating a product shape for die design, characterized in that the surface is classified into the surface (type CB surface) and the other surface (type C-0 surface). 3. As a result of grouping according to whether or not surfaces of the same type are adjacent to each other, if there are two or more groups that are not adjacent to each other, one of the groups is undercut (type E surface). In the first method, where one surface of the same type is adjacent to the other surface of the same type, if there is an intersection line as a result of offsetting the adjacent surfaces by the model shape,
The product 10 is separated only by opening the mold in the same direction as the Z-axis, because the surface corresponds to any of the second methods of recognizing the surface as a surface (type E surface) that cannot be removed from the vertical direction. 3. The method for evaluating a product shape for mold design according to claim 2, wherein the evaluation is performed as an undercut portion that cannot be molded. 4. The mold according to claim 1, wherein, when the three-dimensional product model 10 is displayed on the display unit 34, different colors are displayed for different types of surfaces. Product shape evaluation method for design. 5. When displaying the three-dimensional product model 10 on the display unit 34, different highlights are displayed for different types of surfaces.
4. The method for evaluating a product shape for mold design according to 2 or 3.