JPH1177228A - Hot forging method - Google Patents

Abstract

(57) [Problem] The present invention is to efficiently produce a plurality of products having a high degree of irregularity by efficiently using one rod-shaped material without waste, and to increase the product production rate by suppressing the amount of burrs generated. And a hot forging method capable of improving material yield. The hot forging method according to the present invention comprises:
A hot forging method for manufacturing a plurality of products 1A, 1A from zero, wherein ideal rough ground rough material shapes 12a, 12b suitable for forging the plurality of products 1, 1 are obtained, respectively, and the ideal rough ground rough material shapes are obtained. Intermediate forging 1 including all 12a and 12b
A first forging step of hot forging 1 and a dividing step of dividing the intermediate forged product 11 into a plurality of ideal wasteland rough materials 12 and 12 by dividing the intermediate forged product 11 into respective ideal wasteland rough material shapes 12a and 12b. The product 1 intended for the ideal wasteland rough material 12, 12
A, a second forging step of hot forging into a 1A shape.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot forging method capable of improving the yield of materials when a plurality of products are manufactured from one bar-shaped material.

[0002]

2. Description of the Related Art In a conventional hot forging method, a forged product having a complicated three-dimensional shape (hereinafter, referred to as a forged product having a high degree of irregularity) is formed from one bar-shaped material. Volume of the product to be calculated / volume of the rectangular parallelepiped surrounding the product =
This value is small. ) Is known to take more than one.

For example, as shown in FIGS. 14 to 16, a two-cavity forging having two cavities 4c and 4c formed by a mold surface 40 of a lower mold 4a and a mold surface 41 of an upper mold 4b. A hot forging method for obtaining a forged product 1B (see FIG. 13) including two knuckle arms (automobile parts) 1 and 1 and burrs 110a having the same shape from one round bar-shaped material 10a using a mold 4 is known. I have.

The forging die 4 has a facing surface on the side of the lower die 4a in a closed state (see FIG. 15) so that the material can flow smoothly into the cavities 4c and 4c during forging and can be filled. A clearance R1 is formed between the upper die 4b and the opposing surface 410 on the upper die 4b side, and a burr relief portion R2 for reducing a molding load acting on the forging die 4 is formed. The clearance R1 is the height h1
Is about 4 to 6 mm, and the height H2 of the burr relief portion R2 that is continuous with the clearance R1 is about 10 mm.

[0005]

As shown in FIGS. 13, 14, and 17, a forged product 1B forged from one bar-shaped material 10a by the conventional hot forging method is used.
Burr 110a connected to two knuckle arms 1, 1
Inevitably increases. The burr 110a is
Approximately 4 to 10 mm, depending on the size of the forged product 1B
The width w1 and the width w2 are about 8 mm to 20 mm
It is.

Therefore, about 40% to 5% of the rod-shaped material 10a
0% is consumed as burrs 110a formed between and around the two knuckle arms 1, 1 and reduces the yield of the material. Therefore, when manufacturing a forged product having a high degree of irregularity, there is room for improving the material yield.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and seeks an ideal rough ground rough material shape suitable for forging a plurality of products, respectively, and converts an intermediate forged product including all of the ideal rough ground rough material shapes into one rod-shaped material. In addition to being able to produce multiple products with a high degree of irregularity by efficiently using one rod-shaped material without waste, it is also possible to increase the product production rate by suppressing the amount of burrs, and to increase the material yield. It is an object to provide a hot forging method that can be improved.

[0008]

A hot forging method according to the present invention is a hot forging method for producing a plurality of products from one bar-shaped material, and each of the ideal rough ground rough shapes suitable for forging a plurality of the products is obtained. A first forging step of hot forging an intermediate forged product including all of the ideal wasteland rough material shapes, and dividing the intermediate forged product into the respective ideal wasteland rough material shapes to form a plurality of ideal wasteland rough materials. And a second forging step of hot-forging each ideal rough ground rough material into a desired product shape.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Generally, one bar-shaped material used in a hot forging method has a large degree of irregularity (shape complexity) of a product to be forged, or a cross-sectional shape orthogonal to a longitudinal direction. In a case where the cross section is not uniform depending on the position in the longitudinal direction, the one having an outer diameter capable of producing the largest sectional shape is used.

For this reason, the rod-shaped material is about 40 to 5
0% is consumed as burrs, which is wasteful. This hot forging method improves the product ratio of the product shape aimed at the one rod-shaped material, and in order to improve the yield of the material, as a trimming shape having a high product ratio at the stage before hot forging. After obtaining an intermediate forged product including all of the determined ideal rough terrain rough shapes, the intermediate forged product is divided into respective ideal rough terrain rough shapes to obtain a plurality of ideal rough terrain rough materials. The material is subjected to the second forging step singly or simultaneously.

The ideal rough ground rough material shape is defined as a plurality of products having a desired shape (including both a plurality of products having the same shape and a plurality of products having different shapes), which is formed into a single bar. When a product is made from a material, the amount of burrs is small, and it is determined as a trimming shape having a high productization rate. In addition, as the plurality of products having the desired shape, in addition to the plurality of products having the same shape, the plurality of products having different shapes, and the like, in addition to the plurality of products having the same shape, It can also be applied to a combination with a single product having a different shape.

In the first forging step, one rod-shaped material is arranged in advance so that a plurality of ideal rough ground rough material shapes determined as trimmed shapes having a small amount of burrs and a high production rate can be obtained (formed). Cavities (mold space)
Is used. In the dividing process, a plurality of ideal wasteland rough materials included in the intermediate forged product are sheared along the dividing boundary line, and a press device equipped with a dividable shearing die for obtaining a plurality of ideal wasteland rough materials is provided. A splitting device can be used. As a dividing device,
For example, it is possible to use a press device having a cushion mechanism for cutting the intermediate forged product by sandwiching it.

In the second forging step, a forging die is used which forms a cavity (mold space) of a product shape with one die and the other die. A forging die having one or more cavities can be used. The hot forging method of the present invention is used when manufacturing a plurality of products from one rod-shaped material, and is performed in the order of a first forging step, a dividing step, and a second forging step.

In the first forging step, one bar-shaped material is hot-forged, and an intermediate forged product including a plurality of ideal rough terrain rough material shapes determined as trimmed shapes having a small amount of burrs and a high product ratio is obtained. obtain. In the dividing step, the intermediate forged product is divided to obtain a plurality of ideal rough ground rough materials. In the second forging step, the ideal rough ground rough material is hot forged to obtain a forged product having a desired product shape.

As described above, the target product shape obtained after the first forging step, the dividing step, and the second forging step are performed in the order, and after completing each step, has a small amount of burr generated, The rate of commercialization of the material is high, and the yield of the material can be improved. The forged product having the desired product shape is machined while removing burrs separately in a burr removing step.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention, a hot forging method, is a knuckle arm as a product from one round bar-shaped material (automobile part).
Will be described with reference to FIGS. 1 to 12. The hot forging method according to the embodiment includes a first forging step, a dividing step, and a second forging step. By performing each of the above steps in order, one round bar-shaped material 10 (the plane shape shown by a solid line in FIG. Two knuckle arms 1 (see the side shape shown in FIG. 1 and the plan shape shown in FIG. 2) are manufactured from the cross-sectional shape shown in FIG. 5 (the two knuckle arms can be manufactured with the same shape or different shapes). Is).

In the first forging step, the round bar-shaped raw material 10 and the first forging die 2 (see the sectional shapes shown in FIGS. 5 and 6) are used. The round bar-shaped material 10 has a predetermined outer diameter D1 and a predetermined length L1 set in advance. The first forging die 2 includes a lower die 2 a having a concave die surface 20 and an upper die 2 b having a convex die surface 21.

When the mold is closed, the concave mold surface 20 of the lower mold 2a and the convex mold surface 21 of the upper mold 2b
A cavity 2c having a shape similar to that of the intermediate forged product 11 including 2a and 12b (see a two-dot broken line in FIG. 4) is formed.
The ideal rough ground rough material shapes 12a and 12b are two knuckle arms 1 using the round bar material 10 and a round bar material 1 as a material when the shape is plastically worked by hot forging.
The shape is set so that the amount of burrs generated from 0 is minimized.

After the round bar-shaped material 10 is heated to about 1200 ° C., it is set in the lower die 2a of the first forging die 2 (see FIG. 5). Next, as shown in FIG. 6, the round bar-shaped material 10 is hot forged by a lower mold 2a and an upper mold 2b,
An intermediate forged product 11 (see a two-dot broken line in FIG. 4) including two ideal wasteland rough material shapes 12a and 12b is manufactured. In the dividing step, as shown in the plan view of FIG.
Is hot-sheared along the dividing line SS of the two ideal wasteland rough material shapes 12a and 12b.

In this dividing step, the intermediate forged product 11 is sheared along the dividing line SS by the shearing die of the press device and is divided into two, and the two ideal wasteland rough materials 1 shown in FIG.
2, 12. The ideal rough ground rough material 12 has a substantially S-shape with an inner side surface S1 along the dividing line S-S having a band-shaped inclined surface 120 and an outer side surface S2 with a substantially J-shape as viewed in the plan shape shown in FIG. is there.

The ideal rough ground rough material 12 has a vertical surface 121 which forms both short sides of a rectangle when viewed from the side shape shown in FIG.
The other surface 124 which forms a side parallel to the surface 123 and is spaced apart from each other so that the other side opposite to the surface 123 forming one long side between the vertical surfaces 121 and 122 forms a recess. , 125, inclined surfaces 126, 127 inclined toward the surface 123, and the other surface 1 that forms a side parallel to the surface 123 between the inclined surfaces 126 and 127.
28.

In the second forging step, a second forging die 3 shown in FIGS. 11 and 12 is used. The second forging die 3 includes a lower die 3 a having a concave die surface 30 and an upper die 3 having a concave die surface 31.
b. The concave mold surface 30 of the lower mold 3a and the concave mold surface 31 of the upper mold 3b form a cavity (mold space) 3c of the knuckle arm 1 when the mold is closed. This second forging die 3
Is the facing surface 30 on the lower mold 3a side which is in the mold closed state during forging.
In order to reduce the molding load acting on the second forging die 3 at the time of forging, the clearance R1 for smoothly guiding the material to the cavity 3c and filling the space between the facing surface 310 on the side of the upper die 3b and the clearance R1. Is formed.

The clearance R1 (see FIG. 12) formed between the facing surfaces 300 and 310 has a height h1 of about 4 to 6 mm, a width w1 of about 8 mm,
The flash release part R2 continuous with the clearance R1 is:
The height h2 is about 10 mm and the width w1 is about 14 mm. The ideal rough ground rough material 12 is set at a predetermined position of the lower die 3a of the second forging die 3 in a hot state.
a and the upper die 3b, forged products 1A each including the knuckle arm 1 and the burr 110 around the knuckle arm 1.
(See the plan shape in FIG. 3).

In this second forging step, the ideal waste land rough material 12
Because of using, the amount of burr 110 generated in the forged product 1A manufactured by hot forging can be suppressed. That is,
Using the second forging die 3, hot forging is used to create an ideal rough ground rough material 12.
As can be seen from the plan shape of FIG. 10 and the cross-sectional shape of FIG. 12, which show the comparison between the shape of the forged product 1A obtained by plastically deforming and the shape of the ideal rough ground material 12, the amount of burr 110 formed by the conventional forging Burr 110 of product 1B (see FIGS. 13 and 15)
It is smaller than the amount of a.

Further, the forged product 1A is obtained by separating and removing the burr 110 in a finishing step (not shown), as shown in FIG.
The knuckle arm 1 shown in FIG. 2 can be obtained. As described above, according to the hot forging method of the embodiment, in the first forging step, one round bar-shaped material 10 is formed into two ideal rough ground rough material shapes 12.
The intermediate forged product 11 including the a and 12b is hot forged, and the intermediate forged product 11 is divided in a dividing step to obtain two ideal rough ground rough materials 1.
In the second forging step, the ideal rough ground rough material 12 is hot forged, and a forged product 1A including the knuckle arm 1 and the burr 110 around the knuckle arm 1 with a reduced generation amount can be manufactured.

Here, for example, in the case of the conventional hot forging method shown as a comparison, one bar-shaped material 10a is directly forged by hot forging using a forging die 4 (see FIGS. 14 and 15). Since the product 1B is manufactured, the burr 110
a of the rod-shaped material 10a
From that the commercialization rate of the two knuckle arms 1 and 1 is about 40
% To 50%.

On the other hand, when the hot forging method of the embodiment is used, two knuckle arms 1, 1 having a high degree of irregularity can be manufactured by efficiently using one rod-shaped material 10 without waste, and the burr can be formed. Production rate of about 75 with reduced production of 110
% To 85%, which can improve the yield of the material. In the second forging step of the above-described embodiment, the case where the one provided with one cavity 3c is used as the second forging die 3 is shown, but the present invention is not limited to this.
One having a plurality of the cavities 3c may be used. In this case, a plurality of ideal rough ground rough materials 12 can be forged simultaneously, and a plurality of forged products 1A can be obtained.

Further, in the above-described embodiment, the description has been made by applying the case where two knuckle arms 1 and 1 are manufactured. However, the present invention is not limited to this. Applicable when manufacturing products.

[0029]

According to the hot forging method of the present invention, since the above-mentioned structure is employed, a plurality of products having a high degree of irregularity can be manufactured by efficiently using one rod-shaped material without waste, and the amount of burrs generated can be suppressed. To increase the product commercialization rate,
Material yield can be improved.

[Brief description of the drawings]

FIG. 1 is a side view showing a knuckle arm to be formed using a hot forging method according to an embodiment.

FIG. 2 is a plan view showing a plane of the knuckle arm in FIG. 1;

FIG. 3 is a plan view showing a forged product formed in a second forging step of the hot forging method according to the embodiment.

FIG. 4 is an intermediate forging including one rod-shaped material used in the first forging step of the hot forging method of the embodiment and two ideal rough ground rough material shapes manufactured using the rod-shaped material in the first forging step. FIG. 4 is a plan view showing a trimming positional relationship with a product.

FIG. 5 is a diagram illustrating a first forging step of the hot forging method according to the embodiment;
Sectional drawing which shows the state which set one bar-shaped raw material in the forging die.

FIG. 6 is a cross-sectional view showing a state in which an intermediate forged product including two ideal rough ground rough material shapes is manufactured by hot forging from one rod-shaped material using a first forging die in FIG. 5;

FIG. 7 is a plan view showing a cutting boundary for dividing the intermediate forged product obtained in the first forging step of the hot forging method according to the example into two ideal rough ground rough material shapes by a dividing step.

8 is a plan view showing two ideal rough ground rough materials obtained by dividing the two ideal rough ground rough material shapes of the intermediate forged product in FIG. 7 in a dividing step.

9 is a side view of the ideal rough ground material shown in FIG.

FIG. 10 is a plan view showing a comparison between the shape of the ideal waste rough material and the forged product obtained by hot forging the ideal waste rough material in the second forging step in FIG. 8;

FIG. 11 is a cross-sectional view showing a state where an ideal rough ground rough material is set in a second forging die in a second forging step of the hot forging method according to the embodiment.

12 is a cross-sectional view showing a state where a forged product is manufactured by hot forging an ideal rough ground rough material using a second forging die in FIG. 11;

FIG. 13 is a diagram illustrating a forging process of a conventional hot forging method, in which hot forging is performed from one rod-shaped material, two knuckle arms, burrs around each knuckle arm, and burrs connected between the knuckle arms. FIG.

FIG. 14 is a cross-sectional view showing a state in which one bar-shaped material is set in a forging die at a position taken along the line AA in FIG. 13;

15 is a cross-sectional view showing a state in which one bar-shaped material is hot forged by the forging die in FIG. 14 and is manufactured as a forged product.

FIG. 16 is a cross-sectional view showing the forging die and the forged product at a position taken along the line BB in FIG. 13;

FIG. 17 is a sectional view taken along line CC in FIG. 13;

[Explanation of symbols]

1A ... forged product 1 ... knuckle arm 10 ... round bar-shaped material 2 ... first forging die 2a ... lower die 2b ... upper die 2c ... cavity 3 ... second forging die 3a ... lower die 3b ... upper die 3c ... cavity

Claims (1)

[Claims] 1. A hot forging method for producing a plurality of products from one rod-shaped material, wherein an ideal rough ground rough material shape suitable for forging a plurality of the products is obtained, and each of the ideal rough ground rough material shapes is determined. A first forging step of hot forging an intermediate forged product including all of the intermediate forged product; a dividing process of dividing the intermediate forged product into the respective ideal wasteland rough material shapes to form a plurality of ideal wasteland coarse materials; A hot forging method comprising: a second forging step of hot forging a coarse material into a product shape intended for the purpose;