JPH09234536A - Method for deciding shape in pre-process for forging product and method for designing die for forging - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily obtain a cross sectional shape by obtaining a similarity between a new forging product and an existing forged product based on a similarity evaluating formula in consideration of the length of each bar-like datum, respectively and selecting the shape in a pre-process of the existing forged product as the shape in a pre-forging of the new forging product. SOLUTION: After forming the finish forged product to a solid model in the step 1, the data are stored in a data base. Successively, a prescribed shape treatment is executed in the step 3, and the calculation of the similarity S is executed in the step 5. Then, this calculation of the similarity is repeatedly executed by number of the precedents stored in the data base DB in the steps 6, 7. Thereafter, a retrieval of the similar shape is executed in the step 8 and based on plural shapes extracted in the step 9, a newly obtd. shape of the forging product in the pre-process is obtd. from synthesization. Successively, a surface drawing treatment is applied to the bar-like data in the step 10 and the solid model of the forging product as a solid shape is formed.

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, assuming an intermediate shape in the intermediate process.

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

More specifically, in a forging operation, a roughing and finishing die for performing preliminary forming using a forging roll forming, crushing forging, or a wasteland die for facilitating volume distribution from a billet. , And a deburring step of punching out outer burrs and inner burrs using a punching die is sequentially performed. Therefore, it is necessary to correctly determine the intermediate shape of the forged product in each step.

[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 time is required, 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 as a set of rod-shaped data, and then the new forged product and each forged product are obtained. The degree of similarity with the product is obtained based on the similarity evaluation formula, and the shape of the forged product having a high similarity in the previous process is selected as the shape in the previous process of the new forged product. This is a method for determining the shape of a forged product in a pre-process in which the evaluation formula is a formula that takes into account the length of each bar-shaped data in a new forged product and an already forged product.

The second means of the present invention, in the configuration of the first means, selects a plurality of shapes when selecting a shape in a previous step of a forged product having a high degree of similarity. This is a shape determination method for determining the shape of the new forged product in the previous process by synthesizing the shape of the selected forged product in the previous process.

[0010] A third means of the present invention, in the structure of the second means, is a new forging for combining shapes in different steps when combining shapes of a plurality of forged products in a previous step. This is a method for determining the shape of a product in a previous process.

Further, the fourth means of the present invention is based on the first aspect.
Or based on the shape data determined by the shape determining method in the preceding step of the forged product in any one of the third 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-described means, when the shape of a new forged product is given, the shape of a previously forged product stored in advance is compared with each other in the form of bar-shaped data, and similarities are obtained. The shape in the pre-process of the high forged product is selected as the shape in the pre-process of the new forged product, or the shape in the pre-process of a plurality of forged products with high similarity is selected. Since the shapes are synthesized to be the shape in the pre-process of the new forged product, the shape of the predetermined new forged product in the pre-process can be determined very easily and in a short time.

According to the forging die design method, the shape data in the previous process of the new forged product obtained by each of the above-mentioned shape determining methods is used. By obtaining shape data, a mold can be designed very easily even for a complicated shape.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, 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 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 final forging roll or billet in the initial process (hereinafter, referred to as the intermediate forged product, including the forging roll and billet in the initial process) This is a method of calculating the shape of a computer by using a computer device (shown in FIG. 8). In other words, a certain geometric relationship is established between a certain forged product and the intermediate forged product in the previous process, and by utilizing this relationship, the shape of the intermediate forged product in the previous process is changed. It is based on what is required. This shape determining method is a method suitable for a case where the shape of a forged product is a non-axisymmetric article.

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

First, after a final forged product is converted into a solid model (step 1), F = 1 (where F indicates the stage of each process (step 2), and the specific values and the corresponding processes are shown in FIG. 1 is described in the database (DB) (step 2).

Next, predetermined shape processing is performed (step 3). The shape processing includes a dimensionless processing and a rod-shaped data conversion processing, and these processings will be described below.

The purpose of this shape processing will be briefly described. The shapes of the final forged product and the intermediate forged product (including the final forging roll or billet as an initial step) are calculated by a computer. In order to facilitate processing and reduce storage memory, the data is converted not into solid data representing the outer shape but into bar-shaped data (also referred to as pin-shaped data) at grid points.

Here, a method of converting the forged product into bar-shaped data will be described with reference to FIGS. In the present description, the case of a connecting rod 2 as shown in FIG. 2 will be described as a forged product.

First, shape data of a solid model (of course, shape data of another model) of the connecting rod 1 created by normal CAD is read into a computer (not shown).

Next, a quantization unit length u for dimensionless distance data, which will be described later, is obtained. First, as the reference length of the three-dimensional model, both ends of the connecting rod 1,
That is, the center distance B between the small end portion of the hole 2 and the large end portion of the semicircular concave portion 3 is read (or obtained), and the division number n for appropriately dividing the center distance B is determined. Reading (or inputting), the center-to-center distance B is then divided by the number of divisions n, and this value (B / n) is set as the quantization unit length u.

Next, the whole projected view projected on a predetermined plane of the connecting rod 1 is surrounded by a rectangular line 11, and a rectangular plane 12 surrounded by the rectangle is defined by a straight line 1
3 is divided vertically and horizontally. Note that the interval between the dividing straight lines (hereinafter, referred to as dividing lines) 13 is set to the quantization unit length u, and therefore, the short side 12a and the long side 1
2b is a length (L _y , L _x ) that is a multiple of the quantization unit length u.
It is said.

Next, each intersection P of the dividing line 13
_ij (P _mn ) and the intersection P _ij
, A vertical line (a straight line parallel to the z-axis) 14 to the rectangular plane 12 is prepared, and each intersection M _ij1 , M _{ij2 of} each vertical line 14 and the surface of the connecting rod 1 is formed.
_Find the coordinates of (M _ijk ).

Next, in each of the vertical lines 14, the distance Ls _ij1 from the rectangular plane 12 to the connecting rod 1
(Ls _ijk ) and the distance Lc _ij1 (Lc _ijk ) between the surfaces of the connecting rods 1 at the respective vertical lines 14 are calculated. Of course, these distances Ls _ij1 , Lc _ij1
Are used, the coordinates of the intersections P _ij , M _ij1 , and M _ij2 are used.

In the drawings, only the case of P _ij is shown. Next, each of the distances Ls _ij1 obtained above is _calculated.
(Ls _ijk ), Lc _ij1 (Lc _ijk ) are divided by the reference length B of the connecting rod 1 to make it dimensionless, and are used as representative values of the connecting rod 1 at each intersection.

Each of these data, that is, the coordinates of each intersection on the rectangular plane 12, and the dimensionless distance are accumulated as data, and are stored in a database.

The flow chart of the above procedure is shown in FIG. FIG. 4 is a diagram illustrating the data converted into the bar-shaped data according to the above procedure.

That is, the three-dimensional model of the connecting rod 1 shown in FIG. 4A is represented (converted) as a set of line segments as shown in FIG. The data indicating
The amount of data becomes very small.

For example, as compared with the case of a solid model having a complicated shape such as a connecting rod, 1 /
The data amount is about 100 to 1/500. As described above, since the three-dimensional model is represented by a line segment, that is, a set of bar-shaped data, for example, when a certain large three-dimensional model is combined with a small three-dimensional model to produce an intermediate three-dimensional model, It is enough to combine data,
Therefore, the synthesizing operation can be performed in a very short time and easily.

By the way, it was not explained in the above section.
However, as shown in FIG.
2 is present, the vertical line 34 of that part is
Penetrate both sides (upper and lower parts in the drawing) of the concave portion 22 of the screw 21
In this case, the upper and lower penetration portions in the concave portion 22
Distance Lc between 21a and 21b_ij1 , Lc_ij2 And rectangular flat
Distance Ls from plane 32_ij1 And between these penetrations
Distance Ls of space 23 _ij2 Also stored in the database together
Is done.

In the above embodiment, when the distance is made dimensionless, the center-to-center distance B between the small end and the large end is determined.
The reason why the center-to-center distance B is selected is that, for example, when combining this three-dimensional model with another three-dimensional model of the same type, the degree of similarity with other three-dimensional models of the same type is selected. This is because it is convenient when checking.

Next, after setting E = 1 (step 4),
Calculation of similarity is performed (step 5). Note that this E
Is the number (N) 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. The similarity S is determined by the above-described rod-shaped data processing data and the shape data stored in the database DB in advance (of course, this data is also the same bar-data conversion processing as described above). Are represented by the similarity evaluation formula (1) shown below.

[0035]

[Equation 1]

Explaining the similarity S, the bar-shaped data at the predetermined position (i, j) of the new forged product, that is, the line vector (Z) (for example, in FIG. 2, M _ij1 → M
_ij2 ) and the square of the common length of the line segment vector (bar Z), which is the bar-shaped data at the predetermined position (i, j) of the forged product to be compared, is divided by the product of the absolute values of the line segment vectors. Are obtained for each coordinate position, and the sum of these is divided by the total number.

That is, in the database DB, a plurality of (five in the present embodiment) final forgings (in the case of F = 1) and the corresponding shapes (F in the intermediate step as the preceding step) corresponding thereto = 2 to 5) are stored, and the similarity S between the shape of the forged product subjected to the shape processing and the shape of the new forged product is obtained. .

The similarity S is obtained by the above equation (1), and the calculation of the similarity S is performed by the number of cases (five in this embodiment) stored in the database DB.
It is performed repeatedly (steps 6 and 7).

When the calculation of the degree of similarity by the above iterations is completed, the similar product shape is searched. 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. D
B (step 8).

Next, based on the extracted plurality of 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 preceding 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 (2).

[0042]

[Equation 2]

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. The synthesized parts are indicated by dotted lines. In the above synthesis, basically, the roughing shape is synthesized with the roughing shapes, the crushed shape is synthesized with the crushing shapes, and the forging roll (or billet) is synthesized with the forging roll (or billet). However, if the similarity is high, different intermediate processes such as a finished shape and a roughed shape or a roughed shape and a crushed shape are also synthesized.

As described above, when the shape in the previous process is obtained by synthesis, as shown in FIG. 7A to FIG. 7B, the reverse process performed in the shape process (step 3) is performed. That is, the bar-shaped data is subjected to surface treatment to form a solid model of a forged product as a three-dimensional shape (step 10). 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, F representing the process is incremented, and if the number of processes stored in the database DB is smaller than 5 (5 in this embodiment), the process returns to step 3, and Repeat the work up to 11.

In step 12, 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, in step 14, the concave shape (concave surface shape) of the upper die and the lower die is output by the computer device.

In step 15, it is determined whether these shape data should be registered as new data (either automatically or by an operator). If registration is required, all the shape data in each step is registered in the database, and if it is determined that registration is not necessary, the operation is terminated.

In the above description, similar shapes are obtained for all the steps. However, in the case where any of the intermediate steps such as the finishing step, the roughing step, the crushing step, etc. are omitted. In the case of a complicated shape, the same process, for example, the roughing process may be output twice.

A computer is used as an apparatus for obtaining shape data in a pre-process for a new forged product as described above, and a program necessary for each of the above processes is input.

For example, as shown in FIG. 8, a computer main body 41, a display device 42, a keyboard 43
And an input device 45 such as a mouse 44, a hard disk device 46, and a cassette type magnetic tape device (CMT) 4.
7, a CD-ROM device (read-only storage device) 48,
It comprises an output device 51 such as a laser printer 49 and a plotter 50.

With this computer device, the designer looks at the shape of the final forged product (forged product in the intermediate process) displayed on the screen of the display device 42 while watching the input device 4.
By giving an instruction from 5, the shape in the previous process can be designed. Of course, the computer body 4 of necessary shape data
Various methods are conceivable as the input method to 1. A method of directly inputting from the input device 45, 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 can be considered.

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. By the way, in the embodiment, the case where the connecting rod is used as the forged product has been described. Dividing in the Z direction to make it dimensionless,
Thereafter, a reference line and an origin are determined on the reference plane.

[0055]

According to the method for determining the shape of a forged product in the preceding step according to the present invention, when the shape of a new forged product is given, the previously stored shape of the forged product is converted into bar-shaped data. Compared with each other, the shape in the previous process of the forged product with high similarity is the shape in the previous process of the new forged product, or the shape in the previous process of a plurality of forged products with high similarity The shape is selected, and these shapes are synthesized to form the shape in the pre-process of the new forging, so that the shape of the predetermined new forging in the pre-process can be very easily and quickly. Can be determined. In addition, by using the shape data in the previous process of the new forged product obtained by the above shape determination method, particularly by using a computer device or the like to obtain the shape data, even a complicated shape The mold can be designed very easily.

Further, when comparing the shape of the new forged product and the shape of the forged product, the data obtained by the bar-forming processing are compared with each other.
Therefore, the required performance and storage capacity of the computer device are small and economical.

[Brief description of 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 perspective view of a connecting rod for explaining shape processing according to the embodiment;

FIG. 3 is a flowchart showing a procedure for creating a database of the connecting rod.

FIGS. 4A and 4B are diagrams comparing a solid model of the connecting rod and a case where bar-shaped data processing is performed, wherein FIG. 4A is a diagram illustrating a solid model and FIG.

FIG. 5 is a cross-sectional view of a principal part explaining another method in the rod-shaped data conversion processing.

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

FIGS. 7A and 7B are perspective views showing the solidification of the shape in the embodiment, wherein FIG. 7A shows bar-shaped data and FIG. 7B shows a solid model.

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 Connecting rod 2 Hole part 3 Concave part 11 line 12 Rectangular plane 13 Dividing line 14 Vertical line 41 Computer main body 43 Display device 45 Input device 46 Hard disk device DB database

Claims (4)

[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. The shape in the previous process in is obtained in advance as a set of rod-shaped data, and then the similarity between the new forged product and each forged product is obtained based on a similarity evaluation formula. The shape in the pre-process of the forged product with a high forged product is selected as the shape in the pre-process of the new forged product, and the above similarity evaluation formula is taken into account the length of each bar-shaped data in the new forged product and the forged product A method for determining the shape of a forged product in a previous process, characterized in that: 2. A method for selecting a plurality of shapes when selecting a shape in a pre-process of a forged product having a high degree of similarity,
The shape in the previous step of the forged product according to claim 1, wherein the shape in the previous step in the new forged product is obtained by synthesizing the shape in the previous step in the plurality of selected forged products. How to decide. 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 concave shape of a forging die in a pre-process of a new forged product based on a shape determined by the shape determining method in a pre-process of a forged product according to any one of claims 1 to 3. A method for designing a forging die, which is characterized by what is required.