JP2865609B2 - Method for determining shape in pre-process of forged product and method for designing forging die - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of determining a shape of a forged product from a final shape of a forged product (or an intermediate shape in an intermediate process) and a method of designing a forging die for obtaining an intermediate shape in a process before that. .

[0002]

2. Description of the Related Art Usually, when a product is manufactured by forging,
Forging work is performed step by step using a mold having an intermediate shape in the intermediate process.

[0003] Conventionally, an intermediate shape has been assumed based on the experience and intuition of a skilled technician from the product shape, that is, the final shape after completion of forging. Of course, the same applies when assuming an intermediate shape in the preceding process from the intermediate shape.

More specifically, in the forging operation, crushing forging for facilitating volume distribution from a billet, preliminary forming using a rough land mold, and final shaping using a finishing die are performed. Are performed in order. Therefore, it is necessary to correctly determine a rough land shape (a shape after rough striking, that is, a shape before finishing striking) from a shape in a previous process, for example, a finished shape (shape after finishing striking).

[0005] When determining the shape of each forged product in the intermediate step, the final shape of the final product is divided into a plurality of parts along a predetermined direction, for example, a direction in which the forged product extends. The user determines the cross-sectional shape before forging from the relationship established between the cross-sectional shape after forging and the cross-sectional shape before forging (pre-process), and uses the obtained cross-sectional shape for each of the divided parts before forging. The overall shape was required.

[0006]

However, for each divided part of the forged product, it is very troublesome for a designer to obtain the shape before forging from the relationship between the cross section after forging and before forging. However, there is a problem that it takes a lot of time, and there is a limit in improving the design efficiency.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a shape determining method and a design method of a die for forging capable of easily and quickly finding a cross-sectional shape of a forged product in a pre-process.

[0008]

Means for Solving the Problems In order to solve the above problems, a first means of the present invention is a method for determining the shape in a previous step of a new forged product whose shape in a predetermined step is a new forging. First, the shapes of a plurality of forged products whose shapes corresponding to the predetermined process are known and the shapes in the previous process in each of them are obtained in advance, and then the similarity between the new forged product and each of the forged products is similar. Then, the shape in the previous process of the forged product having the highest similarity is selected as the shape in the previous process of the new forged product , and
The similarity evaluation formula is calculated using the feature quantity expressed by the area ratio and the perimeter of the figure.
The characteristic amount expressed by the ratio and the characteristic amount expressed by the ratio between the area and the circumference
Collection amount, feature amount considering the center of gravity, and the type of forging die parting line
This is a method for determining the shape of a forged product in a previous process, which is obtained by adding an evaluation value in consideration of similarity and an expression .

[0009] The second means of the present invention, a predetermined process
Shape determines the shape of the new forged product in the previous process
First, a shape corresponding to a predetermined process is known.
The shape of the plurality of forged products and the front in each
The shape in the process is determined in advance, then the new forged product,
The similarity with each forged product is calculated based on the similarity evaluation formula.
Next, in the pre-process of the forged product with a high similarity
By selecting a plurality of shapes of the forged product and combining the shapes of the selected plurality of forged products in the previous process, the shape of the forged product in the front process of the new forged product is determined. It is.

[0010] A third means of the present invention is the forged product according to the second means, wherein the shapes of the plurality of forged products in different steps are combined when combining the shapes in the previous step. Is a method for determining the shape in the previous step.

Further, the fourth means of the present invention is the above-mentioned second means.
Alternatively, in the configuration of the third means, the similarity evaluation expression is represented by a ratio between the feature amount represented by the area ratio, the feature amount represented by the circumference ratio of the figure, and the area and the circumference. This is a method for determining the shape of a forged product in a pre-process, which is a formula in which a feature value, a feature value in consideration of a center of gravity, and an evaluation value in consideration of similarity of a forging die parting line are used.

Further, the fifth means of the present invention is characterized in that:
Or based on shape data determined by a shape determining method in a preceding step of a forged product in any one of the fourth means,
This is a design method of a forging die for obtaining a concave shape of the forging die.

According to the shape processing method in each of the above means, when the shape of a new forged product is given, the shape of the forged product stored in advance is compared with that of the previously forged product, and the shape of the forged product having a high degree of similarity in the previous process is high. The shape of the pre-process of the new forged product is selected or the shape of the pre-process of a plurality of forged products having high similarity is selected, and these shapes are synthesized to form the new forged product. Because it is the shape of the previous process,
It is very easy and in a short time to determine the shape of a given new forging in the pre-process. Also, determine the similarity
The similarity evaluation formula is calculated using the area ratio, perimeter ratio of the figure, center of gravity, and
And the similarity of the parting line of the forging die is taken into account.
Thus, the similarity can be determined satisfactorily.

According to the forging die design method, the shape data of the new forged product obtained in the preceding process obtained by each of the above-mentioned shape determining methods is used, and in particular, a computer device and three-dimensional CAD software are used. Is used to determine the shape data, so that a mold can be designed very easily even for a complicated shape.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for determining a shape of a forged product in a pre-process according to an embodiment of the present invention will be described below with reference to FIGS.

The gist of the present invention is a method of determining the shape of a forged product having a known shape in a previous process, and more specifically, a forged product as a final product (hereinafter referred to as a final forged product). ), The shape of the forged product in the preceding process, ie, the intermediate process, and the shape of the billet in the initial process (hereinafter, referred to as an intermediate forged product, which includes billets) are converted into a computer device (FIG. 8). This is a method of calculating by calculation using That is, there is a certain geometric relationship between a certain forged product and the intermediate forged product in the previous process, and by using this relationship, the shape of the intermediate forged product in the previous process is determined. It is based on This shape determination method is suitable when the shape of the forged product is an axisymmetric product.

Hereinafter, a method of determining a shape of a forged product in a pre-process will be described with reference to the flowchart of FIG. In the present embodiment, an intermediate forged product from the shape of the final forged product to the billet, that is, a shape in the finishing process (hereinafter, referred to as a finished product), a shape in the roughing process (hereinafter, referred to as a rough product) The following describes a case in which data of the shape in the crushing step (hereinafter, referred to as a crushed product) and the shape in the initial step (the shape of the billet) are obtained. The shape of the final forged product handled here is an axisymmetric product.

First, after the final forged product is converted into a solid model (step 1), M = 1 (where M indicates the stage of each process, and its specific value and the corresponding process are shown in FIG. 1). It is described in the database 11 (step 2).

Next, predetermined shape processing is performed (step 3). The shape processing is roughly classified into a dimensionless processing and a binarization processing, and these processings will be described below.

First, the final forged product is cut at a cross-section passing through the center axis which is the center of symmetry to obtain a two-dimensional cross-section. next,
Of the shape data of this two-dimensional cross section, the radial direction, that is, the width direction of the axis of symmetry, is divided by the outer diameter dimension to make it dimensionless,
The outer diameter (diameter) is set to 1.0.

Similarly, of the two-dimensional cross-section shape data, the height direction is also divided by the outer diameter dimension to make it dimensionless. Then, fine irregularities or patterns in the shape data are not so important in the intermediate process, and are simplified by performing a binarization process. For example, the cut cross section is divided into a mesh of about 80 × 50 (vertical × horizontal), and the shape is represented by an on / off state of this mesh portion. FIG. 2 shows an example of shape data of a forged product subjected to the binarization process (ON / OFF states are indicated by 1 and 0).

Next, after setting K = 1 (step 4),
Calculation of similarity is performed (step 5). Note that this K
Is the number of forged products stored in a database described later, that is, the number of cases.

Here, the processing content of the similarity will be specifically described. This similarity is based on the similarity evaluation expression S _e (described later), which is obtained by combining the above-described binarized data and the shape data stored in the database 11 in advance.
It is represented by a value S converted by a predetermined conversion formula (described later).

To explain the similarity in a manner that is easy to understand, when comparing forged products, first, each shape data is subjected to dimensionless processing and binarization processing, and then to a plurality (for example, a dozen or more small areas). The geometrical features in each of these small areas, such as the area ratio, the circumference ratio, the circumference / area ratio, and the ratio of the center of gravity, are calculated, and the geometrical features in each of the small areas of the forged product are calculated. It is a numerical representation of the chemical similarity.

That is, in the database 11, a plurality of (five in the present embodiment) final forgings (in the case of M = 1) and the corresponding shapes (M in the intermediate step, which is the preceding step) corresponding to this, are stored. = 2 to 5) and the shape processed data subjected to the shape processing are stored, and the similarity between the shape of the processed forged product and the shape of the new forged product is obtained.

The above-described similarity evaluation expression _Se is obtained from the shape of a forged product (hereinafter, referred to as a part in this description) in a two-dimensional cross section and a rectangular figure surrounding the shape. Specifically, a feature amount α corresponding to the area ratio, a feature amount β corresponding to the figure circumference ratio, a feature amount γ which is a ratio of the area to the circumference, a feature amount λ considering the center of gravity,
It is determined as a value obtained by adding a value relating to the cross-sectional area of the part, a value relating to the circumference S of the part, and an evaluation value し た in consideration of the similarity of the parting line of the forging die.

Here, the similarity evaluation expression _Se is specifically shown by the following expression (1).

[0028]

(Equation 1)

In the above equation (1), the meaning of each coefficient is as shown in Table 1 below.

[0030]

[Table 1]

Here, in the above equation (1), the feature amount of the part
α, β, γ, λ and ψ will be described in detail based on the drawings.
You. First, as shown in FIG.
Considering this rectangular figure 22,
Divide vertically and horizontally according to the characteristics
(Indicated by a dashed line) is referred to as a small area 23, and for each of the small areas 23.
Next, the feature amount of the component 21 is extracted. Regarding the feature amount α, a plurality of pixels (also referred to as pixels) in the small area 23
And the total number of pixels in this small area 23 (0 and 1
And the number of pixels in the small area 23 (symbol of 1)
Is the feature amount α, and the following equation (2)
It is represented by α_i = (Number of pixels in one small area) / (total number of pixels in small area) (2) (i = 0 to n: the same applies hereinafter) Shown) and a small area
The circumference of the part 21 in 23 (indicated by the number of pixels)
Is a feature amount β, and is expressed by the following equation (3). β_i = (Perimeter of component in small area) / (perimeter of small area) (3) About feature amount γ Number of pixels in small area 23 (portion indicated by symbol 1)
And the ratio of the peripheral length of the component 21 in the small area 23 to the feature amount γ
And is expressed by the following equation (4). However, in the small area 23
If the number of pixels is 0, γ_i = 0. γ_i = (Perimeter of component in small area) / (number of pixels in small area) (4) About feature amount λ As shown in FIG.
It is represented by However, the number of pixels in the small area 23 (notation 1)
Is 0, x_gi= 0, y _gi= 0 and
I do.

[0032]

(Equation 2)

Equations (5) and (6) are made dimensionless to obtain λ
When (λ _xi , λ _yi ) is obtained, the following equations (7) and (8) are obtained. λ _xi = x _gi / d _xi ··· (7) λ _yi = y _gi / d _yi ··· (8) Evaluation value 型 of the parting line As shown in FIG. It is represented by the ratio of the area of the hatched area formed by the dividing line 32 and the parting line 34 of the second part 33 to the area of the rectangular figure 35 surrounding the whole of both parts 31, 33. That is, it is expressed by the following equation (9). In this case as well, dimensionless processing is performed.

[0034]

(Equation 3)

The similarity S is represented by the following equation (10). S = a / (1 + k × S _e ) (10) In the above equation (10), for example, a = 100 and k = 0.5, and this equation can easily _{calculate the} similarity evaluation value S _e . In other words, if the shapes are exactly the same,
Is to be converted to be a value of.

The similarity S is calculated by the above equation (10), and the calculation of the similarity S is repeatedly performed for the number of cases (five in this embodiment) stored in the database. (Step 7).

When the calculation of the similarity by the repetition is completed, a search for similar products is performed. For example, in the order of similarity, several (for example, about three, of course, only one or an appropriate number) shapes are selected, or shapes whose similarity is equal to or more than a predetermined value are selected. 11 (step 8).

Next, based on the plurality of extracted shapes (ie, shape data), the newly obtained shape of the forged product in the previous process is obtained by synthesis (step 9). Of course, when only one shape is selected, no composition is performed.

Here, a description will be given of a method of obtaining a shape in a previous process from a new forged product and several forged products similar thereto by synthesis. First, after extracting upper mold surface data and lower mold surface data relating to the shapes of similar products in the previous process, the extracted shapes of the upper mold surfaces and the shapes of the lower mold surfaces are compared with each other by the similarity degree. To synthesize using the following formula (11).

[0040]

(Equation 4)

Here, Y _ci : Y coordinate value of the synthesized shape S _z : Similarity of component Z (a, b,...) Y _zi : Y coordinate value of i node of component Z i: Node number .

FIG. 6 illustrates the above synthesizing method. FIG. 6 shows a case where the shapes of the component a and the component b are combined, and the combined shape is indicated by a broken line. Note that, in the above synthesis, basically, the roughed shape is synthesized with the roughed shapes, the crushed shape is synthesized with the crushed shapes, and when the similarity is high, for example, the finished shape and the roughed shape, Alternatively, synthesis of different intermediate processes such as a rough shape and a crushed shape is also performed. The billet is calculated by combining the aspect ratios based on the similarity.

In this way, when the shape in the previous step is obtained by synthesis, the reverse processing performed in the shape processing (step 3) is performed, that is, the dimensionless one is replaced with the original outer diameter at the same ratio. After that, the forged product is solidified as a three-dimensional shape in the previous process by rotating and sweeping (step 10).

The shape of the billet is restored by calculating the cubic root of the ratio between the volume of the new forged product and the volume of the dimensionless billet. Then, the shape of the solidified forged product is temporarily stored in the memory of the computer device as the shape in the previous process.

Then, at step 11, M representing the process is incremented. If the number of processes (five in this embodiment) stored in the database is smaller than the number of processes, the process returns to step 3 and returns to step 11. Repeat the work up to.

In step 11, when the number of processes becomes equal to the predetermined number, it is determined that there is no previous process.
Proceeding to step 13, after the shape data of the solid model in each process is output, it is determined in step 14 whether these shape data should be registered as new (automatically or by the operator). You.

If registration is to be performed, all the shape data in each step is registered in the database, and if it is determined that registration is not necessary, the operation ends. In the above description, similar shapes for all steps were obtained, but intermediate steps in the middle, such as a finishing step, a roughing step, and a crushing step, may be omitted. In the case of a complicated shape, the same process, for example, a roughing process may be output twice.

In FIG. 7, the intermediate forgings 42, 43 and the billet 4 in the preceding process are shown from the final forging 41.
4 shows a case where the shape of No. 4 is sequentially obtained by synthesis. A computer is used as an apparatus for obtaining shape data in a pre-process for a new forged product described above, and a program required for each of the above processes is input.

For example, as shown in FIG. 8, a computer body 1, a display device 2, an input device 5 such as a keyboard 3 and a mouse 4, and a hard disk device 6
, A cassette type magnetic tape device (CMT) 7, and a CD-
It comprises a ROM device (read only storage device) 8 and output devices (not shown) such as a printer and a plotter.

With this computer device, the designer gives an instruction from the input device 5 while watching the shape of the final forged product (forged product in the intermediate process) displayed on the screen of the display device 2, and performs the process in the previous process. Can be designed. Of course, various methods can be considered as a method of inputting necessary shape data to the computer main body 1. A method of inputting directly from the input device 5, a method of inputting from an external storage device, a method of inputting from a special input device (a device capable of inputting a stereoscopic image), and the like are conceivable.

The number of selected similar shapes can be arbitrarily changed from an input device or the like. And
In this computer device, it is possible to easily obtain the data of the concave shape of the die for obtaining the shape of the new forged product in the previous process. For example, it outputs solid data of the shape of the product manufactured by forging in each previous process (intermediate process), finds the difference between the mold block and the solid shape in the previous process, and calculates the concave shape (concave shape) of the mold. ), And then the designer takes into account material yield, machining, etc.
More specifically, the configuration of the mold, for example, the method of dividing the mold can be performed on a computer device.

That is, without drawing the mold, C
It can be manufactured directly by machining using the software of AM.

[0053]

According to the method for determining a shape of a forged product in the preceding step of the present invention, when the shape of a new forged product is given, the shape of the forged product stored in advance is compared with that of the previously forged product, and the similarity is determined. The shape in the pre-process of the forged product having a high forged product is the shape in the pre-process of the new forged product, or the shape in the pre-process of a plurality of forged products having a high similarity is selected, and these shapes are selected. Are synthesized into a shape in the pre-process of the new forged product, so that the shape of the predetermined new forged product in the pre-process can be determined very easily and in a short time. Also,
The similarity evaluation formula to determine the similarity is calculated based on the area ratio,
Considering the similarity of the ratio, the center of gravity, and the parting line of the forging die
It is possible to make a good judgment of similarity
Wear. Furthermore, by using the shape data in the previous process of the new forged product obtained by the above shape determination method,
In particular, by obtaining shape data using a computer or the like, a mold can be designed very easily even for a complicated shape.

[Brief description of the drawings]

FIG. 1 is a flowchart for obtaining a shape of a forged product in a previous process according to an embodiment of the present invention.

FIG. 2 is a view showing a shape processing state of a forged product in the embodiment.

FIG. 3 is a diagram illustrating a feature amount in the similarity in the shape processing according to the embodiment;

FIG. 4 is an explanatory diagram for obtaining a feature amount at a similarity in the shape processing according to the embodiment;

FIG. 5 is an explanatory diagram for obtaining a parting line at a similarity in the shape processing according to the embodiment;

FIG. 6 is a diagram illustrating a shape combining method in the shape processing according to the embodiment;

FIG. 7 is a cross-sectional view in a case where shapes in a previous process are sequentially obtained by the shape determination method of the embodiment.

FIG. 8 is a perspective view showing a computer device for performing the shape processing method according to the embodiment;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Computer main body 2 Display device 5 Input device 6 Hard disk device 11 Database 21 Parts 22 Rectangular figure 23 Small area

Claims (5)

(57) [Claims] 1. A method for determining a shape of a new forged product in a pre-process in which a shape in a predetermined process is a new forged product. In advance, the shape in the previous process is determined in advance, then the similarity between the new forged product and each forged product is determined based on the similarity evaluation formula. The shape in the process is selected as the shape in the previous process of the new forging , and the similarity evaluation formula
Is expressed by the feature amount represented by the area ratio and the perimeter ratio of the figure.
And the amount of feature expressed by the ratio of area to circumference
Considering the similarity between the features that take into account the mind and the parting line of the forging die
A method for determining a shape of a forged product in a previous process, wherein the formula is obtained by adding the obtained evaluation value . 2. A method for determining a shape of a new forged product in a predetermined step, the shape of the new forged product in a previous step. In advance, the shape in the previous process is determined in advance, then the similarity between the new forged product and each forged product is determined based on the similarity evaluation formula. Select multiple shapes in the process
The shape of the selected forged products in the previous process
By synthesizing the shape, it is possible to
Shape determination method in the forging of the previous step, characterized in that to determine the shape. 3. The method for determining a shape of a forged product in a pre-process according to claim 2, wherein, when synthesizing shapes in a pre-process of a plurality of forged products, shapes in different processes are synthesized. . 4. A similarity evaluation formula is obtained by calculating a feature quantity represented by an area ratio, a feature quantity represented by a circumference ratio of a figure, a feature quantity represented by a ratio of an area to a circumference, and a center of gravity. 4. A method for determining a shape of a forged product in a previous process according to claim 2 or 3, wherein the formula is obtained by adding a feature value in consideration of the above and an evaluation value in consideration of the similarity of the parting line of the forging die. . 5. A concave shape of a forging die in a pre-process of a new forged product based on a shape determined by the method for determining a shape of a forged product in a pre-process according to any one of claims 1 to 4. A method for designing a forging die, which is characterized by what is required.