JP2002288238A - Evaluation method for plasticity workability and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plasticity workability evaluation method and a device which enables its ready use and quick obtaining of computation result with required precision. SOLUTION: A shape, defined in advance for evaluation, is stored as 3D data, plural number of sections of metal plates, which are plastic formed into the shape based on the stored 3D data, are formed by a section formation part 22 in parallel with a stamping direction, the peripheral length of each of the sections formed is computed by a computing part for the peripheral length of the section 23, two sections are selected out of the plural sections formed, difference of the peripheral length of the sections and distance between the sections are computed, by a computing part the difference of the peripheral length of the section 24 and the quality of the plasticity workability is decided, based on whether or not located inside a wrinkle-forming area, by referring to a decision table, based on the computed difference of the peripheral length of the sections and the distance between the sections, and a result of the decision is presented. Therefore, without having to use finite element method, evaluation of the plasticity workability of the metal plate is obtained, by computing the difference of the peripheral length, and the distance of the sections based on the shape defined in advance, for the evaluation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for evaluating the formability of a metal plate by simulating the formability of a metal plate with respect to a predetermined desired three-dimensional model.

[0002]

2. Description of the Related Art Conventionally, a predetermined desired 3
When evaluating the plastic workability of a metal plate for a three-dimensional shape model by simulation, the process of plastic deformation of the metal plate by press forming etc. is numerically simulated by the finite element method, and the fracture limit strain data and each calculated The break allowance of each element is calculated and displayed from the strain data of the element.

For example, as disclosed in Japanese Patent Application Laid-Open No. 8-339396, strain data and / or stress data of elements obtained by numerically simulating a process of plastic deformation of a metal plate by a finite element method are disclosed. By calculating the break allowance of each element from the break limit strain data and / or the wrinkle limit data stored in the limit data storage unit, and displaying the calculated break margin data on a contour line distribution, the processing failure phenomenon This makes it possible to visually recognize the possibility of certain breaks and / or wrinkles.

As described above, conventionally, the process of plastic deformation of a metal plate is numerically simulated by the finite element method, and formability is determined from the obtained strain data of each element.

[0005]

However, in the finite element method analysis, in order to perform analysis with higher precision, it is necessary to create a model dedicated to calculation by subdividing the shape into accurate and detailed elements (mesh). In addition, since the finite element method is used, the operation requires a relatively long operation using a high-performance computer, and it is difficult to obtain a quick answer when comparing and examining various shapes. There is a problem that is.

Further, when it is desired to compare various specifications at the product design stage, the conventional method may take several hours to several tens of hours depending on the case. Occurs.

An object of the present invention is to provide a plastic workability evaluation method and apparatus which can be easily used and can quickly obtain a calculation result of a required accuracy.

[0008]

According to a first aspect of the present invention, there is provided a method for evaluating plastic formability, which comprises simulating the plastic formability of a metal plate for a predetermined shape for examination. It is a property evaluation method, and stores information as to whether or not a wrinkle-occurring region is present for a cross-sectional circumference and a cross-sectional interval of a metal plate plastically worked into a predetermined shape for the study as a determination table in advance, The predetermined shape for the study is stored as three-dimensional data, a plurality of cross sections are formed in parallel with the shape based on the stored three-dimensional data, and the cross-sectional circumference of each of the generated cross sections is calculated. Then, two cross sections are selected from the plurality of prepared cross sections, the cross section perimeter difference and the cross section interval between the selected two cross sections are calculated, and the calculated cross section perimeter difference and the cross section are calculated with reference to the determination table. In the area where wrinkles occur based on the interval For determining whether the determined plastic workability of the quality of the metal plate, characterized by presenting the determined quality.

According to a second aspect of the present invention, there is provided a plastic workability evaluation apparatus for simulating the plastic workability of a metal plate with respect to a predetermined shape for examination. A judgment table memory storing a judgment table which is information on whether or not a wrinkle-occurring region exists with respect to a cross-sectional circumferential length and a cross-sectional interval of the predetermined shape for the above-mentioned examination; and a predetermined shape for the above-mentioned examination. Means for storing a plurality of cross-sections in parallel with a shape based on the stored three-dimensional data, and a cross-section for calculating a cross-sectional circumference of each of the generated cross-sections Refer to the perimeter calculating means, the cross-sectional perimeter difference calculating means for selecting two cross-sections from the plurality of created cross-sections, and calculating the cross-sectional perimeter difference and the cross-section interval between the selected two cross-sections, and the determination table. Then Determining means for determining whether or not the plastic workability of the metal plate is good or not based on whether or not the metal sheet is in a wrinkle generation area based on the cross-sectional circumference difference and the cross-sectional interval, and a presenting means for presenting the determined good or bad. It is characterized by.

According to the method and apparatus for evaluating plastic formability according to claims 1 and 2 of the present invention, a predetermined shape for examination is stored as three-dimensional data, and a shape based on the stored three-dimensional data is stored. A plurality of sections are created in parallel to, and the section circumference of each created section is calculated,
Two cross-sections are selected from the plurality of cross-sections created, the cross-sectional circumference difference and the cross-section interval of the selected two cross-sections are calculated, and the calculated cross-section circumference difference and the cross-section interval are referred to the determination table. Based on this, the quality of the plastic workability of the metal plate is determined from whether or not it is in the wrinkle generation area, and the determined quality is presented.

Therefore, according to the method and apparatus for evaluating the formability of a metal plate according to the first and second aspects of the present invention, the plastic deformation process of the metal plate is not analyzed based on the finite element method, but is determined in advance for examination. A plurality of cross sections are formed in parallel based on the determined shape, two cross sections are selected from the plurality of cross sections, and the plastic workability is calculated by calculating the cross section perimeter difference and the cross section interval between the selected two cross sections. Therefore, it is not necessary to create a model for the finite element method analysis, and the plastic workability can be easily evaluated.

Further, according to the method and apparatus for evaluating plastic formability according to the first and second aspects of the present invention, a plurality of cross sections are formed in parallel based on a predetermined shape for examination, and a plurality of cross sections are formed. The plastic workability is determined by calculation from the cross-sectional circumference difference between the two cross-sections selected from and the cross-section interval, so that high-speed calculation can be performed even by low-performance calculation means.
The plastic workability can be quickly evaluated for a plurality of shapes having different shapes provided for the study.

According to a third aspect of the present invention, there is provided a plastic workability evaluation method for simulating the plastic workability of a metal plate with respect to a predetermined shape for examination. For the cross-sectional circumference and cross-section of the metal plate including the skirt portion generated in a shape corresponding to the die face surface when the metal plate serving as the base material is plastically processed into the predetermined shape for the above-described study. Information on whether or not the area is a wrinkle occurrence area is stored in advance as a determination table, and a predetermined shape for the study is stored as three-dimensional data, and based on the stored three-dimensional data including a formed skirt portion. A plurality of sections are created in parallel with the shape, the section circumferences of the created sections are calculated, and two sections are selected from the created sections, and the section circumferences of the selected two sections are selected. Long difference and Calculate the surface interval, refer to the determination table, determine whether the plastic workability of the metal plate is good or not based on whether or not there is a wrinkle generation region based on the calculated cross-sectional circumference difference and the calculated cross-sectional interval. Is presented.

According to a fourth aspect of the present invention, there is provided a plastic workability evaluation apparatus for simulating a plastic workability of a metal plate with respect to a predetermined shape for examination. For the cross-sectional circumference and cross-section of the metal plate including the skirt portion generated in a shape corresponding to the die face surface when the metal plate serving as the base material is plastically processed into the predetermined shape for the above-described study. Storage means for storing a determination table which is information on whether or not the area is a wrinkle occurrence area; storage means for storing a predetermined shape for the study in three-dimensional data; and the storage means including a formed skirt portion. Section creation means for creating a plurality of sections in parallel with the shape based on the obtained three-dimensional data, section circumference calculation means for calculating the section circumference of each created section, and 2 Cross-section perimeter difference calculating means for calculating the cross-section perimeter difference and cross-section interval between the selected two cross-sections, and referring to the determination table, based on the calculated cross-section perimeter difference and cross-section interval. It is characterized by comprising a determining means for determining whether or not the plastic workability of the metal plate is good or not based on whether or not the metal sheet is in a wrinkle generating area, and a presenting means for presenting the determined good or bad.

According to the method and apparatus for evaluating plastic workability according to claims 3 and 4 of the present invention, in addition to the method and apparatus for evaluating plastic workability according to claims 1 and 2 of the present invention, A skirt portion in the case of forming from a metal plate is added to determine whether the metal plate has good plastic workability.

Therefore, according to the plastic workability evaluation method and apparatus according to claims 3 and 4 of the present invention, since the skirt portion is added, it is inconvenient to pay attention only to the shape for examination. Even when it is necessary to consider the drawing depth and the area of the base material, the plastic workability can be easily evaluated.

In the method and apparatus for evaluating plastic formability according to the first to fourth aspects of the present invention, a reference plane having a normal line perpendicular to a press direction for plastic working is set, and is parallel to the reference plane. A cross section obtained by virtually cutting the shape with a plane may be used as the cross section.

In the method and the apparatus for evaluating plastic formability according to the first to fourth aspects of the present invention, a reference plane having a normal line perpendicular to a press direction for plastic working is set, and is parallel to the reference plane. In the case where the cut surface obtained by virtually cutting the shape in the plane is the cross section, the position of the cross section to be created can be specified, so that the cross section can be formed in a direction that takes into account the pressing direction, and the calculation accuracy can be improved, The plastic workability can be evaluated with high accuracy.

In the method and apparatus for evaluating workability according to the first to fourth aspects of the present invention, the cross section may be created within a specified range.

In the method and apparatus for evaluating plastic formability according to the first to fourth aspects of the present invention, when the cross section is formed within a specified range, the range for forming the cross section may be specified. In order to be able to do so, specify only the area where the aperture is deeply likely to wrinkle and its vicinity,
It is only necessary to perform calculations within a limited range, and there is no need to perform unnecessary calculations, and the plastic workability can be evaluated more quickly.

In the method and apparatus for evaluating workability according to claims 1 to 4 of the present invention, the cross sections may be created at specified intervals.

In the method and apparatus for evaluating plastic formability according to the first to fourth aspects of the present invention, when the cross sections are formed at specified intervals, the intervals at which the cross sections are formed can be specified. Therefore, it is possible to increase the accuracy of plastic workability evaluation by narrowing the cross-section interval for the part that you want to check in more detail, and to increase the cross-section interval for the part that only needs to be roughly checked. The calculation can be eliminated, and the evaluation of the plastic workability can be obtained more quickly.

In the method and apparatus for evaluating plastic formability according to the first to fourth aspects of the present invention, a plurality of determination tables may be provided according to the plate thickness or the material.

In the plastic workability evaluation method and apparatus according to the first to fourth aspects of the present invention, when a plurality of judgment tables are provided according to the sheet thickness, the judgment tables are provided according to the sheet thickness or the material. Therefore, even when the thickness or the material is changed for a model having the same shape, the plastic workability can be easily and accurately evaluated.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the method and apparatus for evaluating plastic workability of the present invention will be described below.

FIG. 1 is a schematic diagram showing the configuration of a plastic workability evaluation apparatus for implementing the plastic workability evaluation method of the present invention.

The plastic workability evaluation apparatus 1 shown in FIG. 1 is composed of a stand-alone computer or an engineering workstation, and has a CPU 2 and three-dimensional data of a predetermined shape to be examined based on a boundary expression subjected to interference check. 3D model designating means 3 for designating a three-dimensional model of the shape of the fuel tank bottom plate in the motorcycle shown in FIG. Input means 4 for instructing calculation parameters including a thickness and a material of a metal plate to be plastically worked to form a shape to be examined, a pressing direction, a calculation range as a cross-section creation range, a cross-section separation, and the like; A RAM 5 that constitutes a temporary memory for storing the information and the operation result specified in 4, A determination table memory 6 the determination table is stored for determining the plastic workability per genera plate thickness of the material, and an output unit 7 is a presenting means for presenting the like determination result.

Here, the material is a kind of a metal plate material as a base material to be plastically processed. For example, even when the metal plate is a steel plate, steel plates having different fine specifications are different materials, and only the steel plate is used. The same applies to the case of an aluminum plate or the like.

As shown in FIG. 4, for example, the determination table memory 6 stores the formability based on the distance (Lc) between the cross sections and the cross-sectional circumference difference | Lb-La | for each metal plate material. In order to determine pass / fail, information on an area in which wrinkles are generated by molding (wrinkle generating area) and an OK area in which wrinkles are not generated by molding are stored in the form of a table. The determination table can be specifically determined in advance experimentally or empirically.

In the specification of the calculation range by the input means 4, two reference planes having normals perpendicular to the pressing direction input for the plastic working are set. Here, the reference plane is designated by the input means 4 because it is desired to virtually cut the shape 8 (see FIG. 3) on a plane parallel to the reference plane to form a virtual cross section in order to create a virtual cross section. Yes, simply by specifying the press direction, it is not possible to specify the direction in which the shape 8 is virtually cut in order to create a cross-section. Therefore, a reference plane having a normal line orthogonal to the input press-out direction. Is specified. Furthermore, the reason why two reference planes are set is that a region sandwiched between the two reference planes is used as a section creation range, and the section creation range is designated thereby.

In the specification of the calculation parameters by the input means 4, in addition to the specification of the cross-section interval, as described above, the specification of whether the shape 8 is symmetrical and the specification of whether or not to specify the die face surface are given. Done. The specification of the cross-section interval is for specifying the cross-section interval when virtually cutting the shape 8 to generate a cross-section, and the specification of whether the shape 8 is symmetrical is determined by calculating the width of the shape 8 in the calculation of the cross-sectional circumference. When it is symmetrical with respect to the center of the direction, the section circumference to the center is calculated and the result is calculated as 2
This is because it is sufficient to multiply by the cross-sectional circumference and the calculation of the cross-sectional circumference can be simplified. The instruction as to whether or not to specify the die face surface is arbitrary, and may be selectively specified as needed.

The CPU 2 functionally generates three-dimensional data based on the 3D model specified by the 3D model specifying means 3 and stores the three-dimensional data in the three-dimensional data storage area of the RAM 5; In the direction in which the shape 8 is virtually cut to create the cross-section specified by 4, within the specified cross-section creation range, and at the specified cross-section interval, the three-dimensional data generation unit 21 stores the three-dimensional data in the RAM 5. Section creation unit 2 for virtually creating a section of shape 8 formed by three-dimensional data stored in the storage area
2, a section circumference calculating section 23 for calculating the section circumference of the section virtually created by the section creation section 22, and two sections selected from the section created virtually, and the selected section A section perimeter difference calculating unit 24 for calculating the cross section perimeter difference and the distance between the two selected cross sections, and a judgment on the sheet thickness and the material with reference to the sheet thickness and the material input by the input means 4. The table is read out from the determination table memory 6, and with reference to the read out determination table, it is determined whether or not the area is within the wrinkle generation area based on the distance between the cross sections calculated by the cross section circumference difference calculating section 24 and the cross section circumference. And a formability judging section 25 for outputting the judgment result to the output means 7 for display.

The operation of the plastic workability evaluation apparatus 1 configured as described above will be described with reference to the flowchart shown in FIG.

When a plastic workability evaluation instruction is issued, a plastic workability evaluation routine is entered, and three-dimensional data based on the 3D model of the shape 8 to be examined, specified by the 3D model specifying means 3, is output by the three-dimensional data generation unit 21. It is generated and stored in the three-dimensional data storage area of the RAM 5 (step S1), the plate thickness, the material and the pressing direction input from the input means 4 are read (step S2), and then the cross section input from the input means 4 The creation range is read (step S3), and then the input section interval is read (step S4).

Following step S4, the shape 8 based on the three-dimensional data stored in the RAM 5 in step S1.
, Two reference planes having normals perpendicular to the input press direction are set based on the information read in steps S2, S3 and S4, and the set two reference planes A plurality of cross sections are created by virtually cutting the shape 8 at a plane parallel to the reference plane and at a distance between the read cross sections for creating a cross section within the cross section creation range. The section circumference of each section is calculated by the section circumference calculation unit 23 (step S5).

In the calculation of the cross-sectional circumference in step S5, when the input means 4 designates that the right and left sides are symmetric, the shape 8 has a center line in the left and right width direction indicated by a broken line as shown in FIG. 9, and in this case, the section circumferences up to the center line 9 are calculated, and the calculated section circumferences are doubled to calculate the section circumferences La and L.
Since b is obtained, the calculation of the cross-sectional circumference becomes simple.

Subsequent to step S5, two cross sections are selected from the plurality of prepared cross sections (the selected two cross sections are schematically shown by dashed lines a and b in FIG. The lengths are La and Lb, respectively), and the difference | L between the cross-sectional circumferences (La, Lb) of the two selected cross-sections | L
b-La | and the distance (Lc) between two selected cross sections
Is calculated by the section circumference difference calculator 24 (step S6).

Subsequent to step S6, the judgment table schematically shown in FIG. 4 for the sheet thickness and the material input by the input means 4 is read out, and the read out judgment table is referred to for calculation. Cross-sectional circumference difference | Lb-La
The plastic workability is determined based on | and the distance between the cross sections (Lc) depending on whether the area is within a wrinkle generating area or an OK area where no wrinkle occurs (step S7).

When the intersection between the cross-sectional circumference difference | Lb-La | and the distance (Lc) between the cross-sections is located within the wrinkled region in FIG. 4, it is determined that wrinkling occurs due to plastic working and plastic workability is poor. When the intersection between the cross-sectional circumference difference | Lb-La | and the distance (Lc) between the cross sections is located in the OK region in FIG. 4, no wrinkles are generated by plastic working, that is, if the plastic workability is good. The determination is made by the formability determination unit 25.

After step S7, the result of the determination is output to the output means 7 and displayed (step S8). Subsequent to the display in step S8, the other two cross sections are selected (step S9), and it is checked whether the selection has been completed for all combinations (step S10).
If it is determined in step S10 that all combinations have not been selected, the process is executed again from step S6.

If it is determined in step S10 that all combinations have been selected, the plastic workability evaluation routine ends.

When n cross sections are created in step S5, when the number of combinations _n C ₂ for selecting two out of n is completed in step S10, the plastic workability evaluation routine is executed. When the process is completed and at least one of the combinations is determined to be within the wrinkle region, it is determined that the plastic workability is poor.

Next, when the calculation parameters are specified by the input means 4, in addition to the specification of the cross-section interval, an instruction to specify whether the shape 8 is symmetrical and to specify the die face surface is given. explain.

Hereinafter, a case where the fuel tank bottom plate of the motorcycle is formed by press working as in the case shown in FIG. 3 will be described as an example.

The reason for designating the die face surface when the fuel tank bottom plate is formed by pressing with a die and a punch will be described.

As schematically shown in FIG. 5, the base material 33 shown in FIG. 5A is inserted between the punch 32 and the die 31 as shown in FIG. The fuel tank bottom plate, which is the target object, is formed by pressing and pressing the peripheral edge of the base material 33 with the holder 37 located.
The base material 33 is a skirt portion 3 composed of a shape 8 portion and a base material 33 stretched around the shape 8 portion by pressing.
The semi-finished product 34 shown in FIG. In FIG. 5B, reference numeral 36 denotes a die face.

The portion of the skirt portion 35 in the semi-finished product 34 is finally removed as shown in FIG.
The shape of the object as a finished product is 8, that is, the fuel tank bottom plate. In FIG. 5C and FIG. 5D, the case where the skirt portion 35 is wrinkled is exaggerated for convenience of explanation.

For this reason, when the plastic workability is evaluated, it may be inconvenient to focus only on the shape of the 3D model, and the distance from the bottom of the molding hole of the die 31 to the die face 36, that is, Draw depth and die face 3
It is necessary to consider whether the surface 6 is flat or curved.

The configuration of the plastic workability evaluation apparatus 1 for designating the die face surface is the same as that of the schematic diagram shown in FIG. 1, and a description thereof will be omitted to avoid duplication.

The operation of the plastic workability evaluation apparatus 1 when designating a die face surface will be described with reference to the flowchart shown in FIG.

When a plastic workability evaluation instruction is issued, a plastic workability evaluation routine shown in FIG. 6 is entered, and three-dimensional data based on the 3D model of the shape 8 to be examined specified by the 3D model specifying means 3 is converted into three-dimensional data. The base material 3 generated by the data generation unit 21 and stored in the three-dimensional data storage area of the RAM 5 (step S1) and input from the input unit 4
3 is read (step S2), the section creation range input from the input means 4 is read (step S3), and then the input section interval is read. (Step S4). Steps S1 to S4 are the same as those in FIG.

Here, the die face surface is a three-dimensional CAD
Any planar die face imaginable from the model shape above or a curved die face may be used.
This is done by defining a die face that can be assumed from the model shape above. According to an instruction for designating a die face surface, (1) when data of a predetermined die face surface is used, (2) when the die face surface is regarded as a plane and is automatically generated, (3) when the die face is 3 There are three cases where a new curved surface is newly generated. In the case of a plane die face, it is as schematically shown in FIG. 7, and in the case of a curved die face, it is as schematically shown in FIG. Regarding the generation of the die face, the die face may be generated in advance, or the die face may be generated by executing a separately provided die face creation routine.

Returning to FIG. 6, following step S4, it is checked whether or not an instruction to designate a die face surface has been given by the input means 4 (step S4a). In step S4a, when it is determined that the designation of the die face surface has not been performed, the die face is regarded as a flat surface according to the default rule, and the flat die surface is automatically placed at an arbitrary plane position whose normal is the pressing direction. It is generated (step S4c). If it is determined in step S4a that the instruction to specify the die face surface has been issued, the instruction to specify the die face surface is read from the input means 4, and a curved surface die face is generated based on the determination instruction (step S4b). ).

Subsequent to the execution of step S4b or step S4c, step S1 is performed on the shape 8 based on the three-dimensional data stored in the RAM 5 in step S1.
2. Based on the information read in S3 and S4, two reference planes having a normal line perpendicular to the input press direction are set, and the set two reference planes are set as a section creation range. A plurality of cross sections are formed by virtually cutting the shape 8 and the skirt portion 35 in a plane parallel to the reference plane for cross section creation and separated at the cross section interval read in step S4 within the section creation range. Is created, and the cross-section circumference of each cross-section is calculated by the cross-section circumference calculation unit 23 (step S5a).

Although the end face shape of the base material 33 has a microscopic unevenness corresponding to the drawing depth depending on the press working such as deep drawing, this is ignored in FIGS. 7 and 8. Calculation and display.

In the calculation of the cross-sectional circumference in step S5a, when the input means 4 designates that the right and left sides are symmetric, the broken line is shown in FIGS. 7 and 8 as in the case of the shape 8 shown in FIG. The skirt portion 35 is included when the base material 33 is inserted symmetrically with respect to the center line 9 in the left and right width directions shown in FIG. The section perimeter up to the center line 9 is calculated, and the calculated section perimeter is doubled to determine the section perimeter, thereby simplifying the calculation of the section perimeter.

Subsequent to step S5a, two cross sections are selected from the plurality of prepared cross sections, and respective cross-sectional circumferential lengths (La ', Lb') of the selected two cross sections are obtained. The difference | Lb'-La '|
And the distance (Lc) between the two selected sections is calculated by the section circumference difference calculator 24 (step S6a).
Here, two selected cross sections are shown in FIG. 7 (a) and FIG.
(A) is schematically indicated by alternate long and short dash lines a 'and b', and their cross-sectional circumferential lengths are denoted by La 'and Lb', respectively.

Here, the calculation of the section circumference will be described. FIGS. 7A and 7B show a case of a plane die face, and FIGS. 8A and 8B show a case of a curved die face. FIGS. 7A and 8
In (a), the thin dashed line schematically shows the locus of a portion that is bent by the press working for forming the shape 8, and is also the locus of a perpendicular foot described later. An edge indicated by a two-dot chain line is set on the semi-finished product 34 generated by the plane die face and on the semi-finished product 34 generated by the curved die face.

FIG. 7 (b) schematically shows the shape 8 and the skirt portion 35 corresponding to FIG. 7 (a).
(B) schematically shows the shape 8 and the skirt portion 35 corresponding to FIG. 8 (a).

The calculation of the cross-sectional length of the skirt portion 35 and the shape 8 is the same in the case of the plane die face surface as in the case of the curved die face surface, and will be described with reference to FIG.

The end point Pa1 of the section a '(b') of the shape 8
(Pb1), the perpendicular foot lowered from the die face surface direction to Pa2 (Pb2), and the perpendicular foot Pa2 (Pb2)
2) When the point of intersection with the end side when the end point is moved along the section a ′ (b ′) along the section a ′ (b ′) is Pa3 (Pb3), the section circumference La ′ of the section a ′ and the section b The cross-sectional circumference Lb ′ of the shape 8 is defined as La, where L is the circumference of the cross-section a ′ of the shape 8 itself and Lb is the circumference of the cross-section b ′ of the shape 8 itself
As shown in equation (1).

The cross-sectional circumference La ′ including the skirt 35 of the cross section a ′ and the cross-sectional circumference L including the skirt 35 of the cross section b ′
b ′ becomes as shown in the equation (1) because the point Pa1 (P
b1), the points Pa2 (Pb2), and the points Pa3 (Pb3), and the points Pa4 (Pb4), Pa5 (Pb5), and Pa6 on the back side of the corresponding shape 8 in FIG.
This is because (Pb6) exists.

The above calculation of the cross-sectional circumference is the same in the case of the curved die face shown in FIG.

[0064]

(Equation 1)

Therefore, in FIG. 4, the circumferential length difference | Lb−
In accordance with the determination table obtained for the perimeter difference | Lb'-La '| instead of La |, the plate thickness and / or the material input by the input means 4 are in the wrinkle generation region or wrinkles are generated. The plastic workability is determined depending on whether the region is within the OK region not to be used (step S7a).

When the intersection of the cross-sectional circumference difference | Lb'-La '| and the distance (Lc) between the cross sections is located within the wrinkle region in FIG. 4, wrinkles are generated by plastic working and poor plastic workability is considered. It is determined that when the intersection between the cross-sectional circumference difference | Lb'-La '| and the distance between the cross-sections (Lc) is located in the OK region in FIG.
That is, if the plastic workability is good, the formability determination unit 25
Is determined by

After step S7a, the determination result is output to the output means 7 and displayed (step S8a). Subsequent to the display of the determination result in step S8a, the other two cross sections are selected (step S9a), and it is checked whether the selection has been completed for all combinations (step S10). If it is determined in step S10 that all combinations have not been selected, the process is executed again from step S6a.

If it is determined in step S10 that all combinations have been selected, the plastic workability evaluation routine ends.

If n cross sections have been created in step S5a, then in step S10 two out of n cross sections are created.
The plastic workability evaluation routine ends when the number of combinations _n C ₂ has been completed, and when at least one of the combinations is determined to be within the wrinkle region, the plastic workability is determined. Is determined to be bad.

If the plastic workability is determined to be poor by such a determination, the plastic workability can be improved by modifying the die, such as modifying the shape of part or all of the die face surface.

Here, regardless of the presence or absence of the designation instruction of the die face surface, when it is determined that the area is within the wrinkled area, the output means 7 may present the image in a different display color.

Regardless of whether the designation of the die face surface is designated or not, in the above, the section forming range for forming the section can be specified. By selecting as the cross-section creation range, plastic workability can be determined for a limited range, and the amount of calculation is small,
It is possible to know plastic workability more quickly.

Further, the cross section interval can be specified regardless of whether or not the die face surface is specified.
It is possible to specify a narrow cross-section interval or a wide specification, and it is possible to increase the accuracy of judgment by narrowing the cross-section interval for parts where plastic workability is desired to be determined in more detail, for example, a part with a deep drawing. For a part that can be roughly checked, the section interval is widened and the number of calculations is reduced, so that the determination of the plastic workability can be quickly obtained.

Further, regardless of the presence or absence of the designation of the die face surface, a determination table is provided corresponding to the thickness and / or the material of the metal plate to be plastically processed, and the thickness and / or the material to be plastically processed are determined. By specifying, by referring to the determination table for the metal plate of the specified plate thickness, it is possible to determine the thickness and / or plastic workability depending on the case of the material, if necessary, the plate thickness,
Alternatively, the determination can be performed again for a determination model having the same shape by changing the material, which is extremely convenient. As described above, it is possible to easily determine even when the thickness and / or the material are changed.

Further, regardless of the designation of the designation of the die face surface, a direction in which the shape 8 is virtually cut in order to create a cross section can be specified in the above, and the cross section is formed by cutting in the direction. Therefore, it is possible to accurately determine the plastic workability.

Also, regardless of the presence or absence of the designation of the die face surface, the reference direction having the normal perpendicular to the press direction is automatically specified after the press direction is input. The cut surface for obtaining the target is specified.

[0077]

As described above, according to the plastic workability evaluation method and apparatus according to the present invention, the plastic workability can be easily reduced, for example, from one second to several seconds without any knowledge of the finite element method or the like. Can be instantaneously evaluated, the plastic workability specification of the metal plate can be compared with a predetermined shape for various studies, and a product with high productivity can be designed.

Further, according to the method and the apparatus for evaluating plastic formability according to the present invention, the plastic deformation process of a metal plate is not analyzed by the finite element method, but its cross section is determined based on a predetermined shape for examination. It is sufficient to obtain the perimeter and the cross-section interval, and it is not necessary to create a model dedicated to the finite element method analysis, and it can be used easily.

Further, according to the method and apparatus for evaluating plastic formability according to the present invention, plastic formability can be obtained based on the section interval and the section circumference, so that a low-performance computer can calculate at high speed. In addition, even when calculation is performed on a large number of shapes having different shapes, it is possible to easily and quickly evaluate the plastic workability.

Further, according to the method and apparatus for evaluating plastic formability according to the present invention, it is not convenient to pay attention only to the shape, and even if it is necessary to consider the drawing depth and the area of the base material, the plastic formability is evaluated. Workability can be easily evaluated.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a configuration of a plastic workability evaluation apparatus according to one embodiment for carrying out a plastic workability evaluation method of the present invention.

FIG. 2 is a flowchart for explaining the operation of the plastic workability evaluation apparatus shown in FIG.

FIG. 3 is a perspective view showing an example of a shape evaluated by the plastic workability evaluation device shown in FIG.

FIG. 4 is a schematic diagram showing an example of a determination table in the plastic workability evaluation device shown in FIG.

FIG. 5 is an explanatory diagram of shape forming evaluated by the plastic workability evaluation method of the present invention.

FIG. 6 is a flowchart for explaining the operation of the plastic workability evaluation apparatus in the case of designating a die face surface in the plastic workability evaluation method of the present invention.

FIG. 7 is a schematic explanatory diagram of a section circumference calculation when a die face surface is a plane.

FIG. 8 is a schematic explanatory diagram of a section circumference calculation when the die face surface is a curved surface.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Plastic workability evaluation apparatus 2 ... CPU 3 ... 3D model designation means 4 ... Input means 5 ... RAM 6 ... Judgment table memory 7 ... Output means 21 ... Three-dimensional data generation part 22 ... Section creation part 23 ... Section circumference calculation Part 24: Cross section circumference difference calculating part 25 ... Formability determining part 31 ... Die 32 ... Punch 33 ... Base material 34 ... Semi-finished product 35 ... Skirt part 36 ... Die face

Continuing from the front page (72) Inventor Hiroyuki Kamo 1-4-1 Chuo, Wako-shi, Saitama Pref. Honda Research Institute (72) Inventor Tomoyuki Tagami 1-4-1 Chuo, Wako-shi, Saitama Co., Ltd. Honda R & D F-term (reference) 5B046 AA05 DA01 DA02 JA07

Claims (13)

[Claims] 1. A method for evaluating the formability of a metal plate by simulating the formability of a metal plate with respect to a predetermined shape for examination, comprising: The information as to whether or not the area is a wrinkle generation area is previously stored as a determination table with respect to the cross-sectional circumference and the cross-section interval of the metal plate, and the predetermined shape for the study is stored as three-dimensional data. A plurality of cross-sections are created in parallel with the shape based on the created three-dimensional data, the cross-sectional perimeter of each created cross-section is calculated, and two cross-sections are selected from the plurality of created cross-sections and selected. Calculate the cross-sectional circumference difference and the cross-section interval of the two cross-sections, and refer to the determination table to determine whether or not the metal plate is in the wrinkle-occurring area based on the calculated cross-section perimeter difference and the cross-section interval. Judge the pass / fail of the A plastic workability evaluation method characterized by presenting the quality of the workability. 2. A plastic workability evaluation device for simulating the plastic workability of a metal plate with respect to a predetermined shape for examination, comprising: A determination table memory storing a determination table that is information on whether or not the area is a wrinkle-occurring area with respect to the length and the cross-section interval; Section creation means for creating a plurality of sections in parallel with the shape based on the created three-dimensional data; section circumference calculation means for calculating the section circumference of each created section; And a cross-sectional circumference difference calculating means for calculating the cross-sectional circumference difference and the cross-section interval between the selected two cross-sections, and the calculated cross-sectional circumference difference and the cross-section interval with reference to the determination table. Departs from wrinkles Plastic workability evaluating apparatus characterized by comprising determination means for plastic working of the quality of the metal plate depending on whether the region, and presenting means for presenting the determined quality, a. 3. A method for evaluating the formability of a metal plate by simulating the formability of a metal plate with respect to a predetermined shape for examination, the method comprising the steps of: A table for determining in advance whether or not there is a wrinkle-occurring region with respect to the cross-sectional circumferential length and cross-sectional interval of a metal plate including a skirt portion generated in a shape corresponding to a die face surface when plastic working is performed in a predetermined shape. The predetermined shape for the study is stored as three-dimensional data, and a plurality of cross sections are formed in parallel with the shape based on the stored three-dimensional data including the molded skirt portion. Calculate the cross-sectional circumference of each of the selected cross-sections, select two cross-sections from the created cross-sections, calculate the cross-sectional circumference difference and the cross-section interval of the selected two cross-sections, and refer to the determination table. do it A method for evaluating the formability of a metal sheet, comprising determining whether or not a metal sheet is in a plastic workability based on whether or not the metal sheet is in a wrinkle-occurring region based on the calculated cross-sectional circumference difference and the cross-section interval, and presenting the determined quality. . 4. A plastic workability evaluation device for simulating the plastic workability of a metal plate with respect to a predetermined shape for examination, wherein a metal plate serving as a base material is used for the examination. A determination table which is information on whether or not a wrinkle-occurring region is present with respect to a cross-sectional peripheral length and a cross-sectional interval of a metal plate including a skirt portion generated in a shape corresponding to a die face surface when plastic working is performed to a predetermined shape. Storage means for storing a predetermined shape for the study as three-dimensional data, and a cross section parallel to a shape based on the stored three-dimensional data including a molded skirt portion. Means for creating a plurality of sections, a section circumference calculating means for calculating the section circumference of each section created, and two sections selected from the plurality of sections created, and the selected two sections of A section perimeter difference calculating means for calculating a surface perimeter difference and a cross section interval; and a plasticity of the metal plate based on the calculated cross section perimeter difference and the cross section interval. A plastic workability evaluation device, comprising: a determination means for determining the quality of workability; and a presentation means for presenting the determined quality. 5. A method for evaluating plastic formability according to claim 1, wherein a reference plane having a normal line perpendicular to a press direction for plastic working is set, and a plane parallel to said reference plane is set. A method for evaluating plastic formability, wherein a cut surface obtained by virtually cutting the shape is used as the cross section. 6. A method according to claim 1, wherein said cross section is formed within a specified range. 7. A method according to claim 1, wherein said cross-section is formed at a specified interval. 8. The method according to claim 1, further comprising a plurality of judgment tables according to the thickness or the material of the metal plate to be plastically worked. Evaluation method. 9. The apparatus for evaluating plastic formability according to claim 2, wherein the section forming means includes reference plane designating means for setting a reference plane having a normal line perpendicular to a press direction for plastic working, A plastic workability evaluation apparatus, wherein a cut surface obtained by virtually cutting the shape with a plane parallel to the reference plane is defined as the cross section. 10. A plastic workability evaluation apparatus according to claim 4, wherein said cross section creating means includes reference plane designating means for setting a reference plane having a normal line perpendicular to a press direction for plastic working, A plastic workability evaluation apparatus characterized in that a cut surface obtained by virtually cutting the shape including the skirt portion on a plane parallel to the reference plane is the cross section. 11. The apparatus for evaluating plastic formability according to claim 2 or 4, wherein said section creating means includes section creating range designating means, and the section creating range designating means designates a range in which said section is created. A plastic workability evaluation device characterized by: 12. The plastic formability evaluation apparatus according to claim 2, wherein said section creating means includes a section creating interval designating means, and designates an interval of the section created by said section creating interval designating means. A plastic workability evaluation device, characterized in that: 13. The plastic workability evaluation apparatus according to claim 2, wherein the judgment table memory includes a plurality of judgment tables according to the thickness or the material of the metal plate to be plastically worked. A plastic workability evaluation device characterized by the following.