JP2596687B2 - Manufacturing method of light alloy wheel - 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 for manufacturing a light alloy wheel for manufacturing a one-piece wheel by forging a light alloy such as an aluminum alloy.

[0002]

2. Description of the Related Art Wheels made of aluminum alloy (hereinafter referred to as aluminum wheels) have been used in automobiles since the 1960's because they are lighter in weight and more fashionable than iron wheels. Initially,
Aluminum wheels were used only in some high-end cars such as sports cars.In recent years, however, popular cars have become more fashionable, and aluminum wheels have been widely used in addition to luxury cars. became.

[0003] Due to its structure, an aluminum wheel is a one-piece wheel in which a disk surface as a design surface and a rim portion for supporting a tire are integrally formed, a two-piece wheel formed by combining two members, and a three-piece wheel. It can be classified into three types of three-piece wheels formed by combining two members. The one-piece wheel is advantageous in that it is uniform in material and thus has little variation in quality and high rigidity. In addition, since the one-piece wheel is integrally formed as a whole, there is a possibility that inconveniences such as missing and loose parts may occur. There is an advantage that this is not the case. Currently, about 85% of all aluminum wheels are one-piece wheels. This one-piece wheel can be classified into a cast wheel and a forged wheel according to the manufacturing method. Cast wheels have the advantage of being easy to manufacture, and at present most one-piece wheels are manufactured by casting.

However, aluminum wheels manufactured by casting have the following disadvantages. That is, in recent years, weight reduction of automobiles has been promoted, and further weight reduction of wheels has been demanded. However, since the metal structure obtained by casting is not as forged as the structure obtained by forging, and since defects such as shrinkage are inherent in the cast material, when trying to further reduce the weight of the wheel, Sufficient strength cannot be obtained.

On the other hand, an aluminum wheel manufactured by forging has an extremely high strength because the metal structure is forged and there are no defects inside the aluminum wheel, and it is easy to reduce the weight compared to a cast wheel. is there.

8 to 14 show a conventional method of manufacturing an aluminum wheel by forging in the order of steps (Japanese Patent Laid-Open No. 61-11564).
0, JP-A-61-115641, JP-A-4-167943).

First, as shown in FIG. 8, an aluminum alloy billet 21 is prepared as a raw material. Then, the billet 21 is forged using the forging dies 31 a and 31 b shown in FIG. 9 to obtain the primary forged material 22.

Next, forging dies 32a, 32 shown in FIG.
b, the primary forged material 22 is forged, and the secondary forged material 2
Get 3. Thereafter, forging dies 33a, 33 shown in FIG.
b, the secondary forging material 23 is forged to obtain a tertiary forging material 24. The portion of the tertiary forged material 24 corresponding to the disk surface of the wheel is formed substantially in the same manner as the final product shape (finished product wheel), and the portion 24a corresponding to the rim portion is smaller than the rim portion of the finished product wheel. Therefore, the thickness is large and the length (the length in the direction parallel to the central axis) is short.

Next, as shown in FIG. 12, the forging material 24 is subjected to spinning by a spinning machine to form a rim portion and a rear flange portion. That is, the third forged material 24
Are attached to the mandrels 34a and 34b of the spinning machine, and while rotating the forged material 24, a roller 35 is pressed against a portion corresponding to the rim to extend in a direction parallel to the central axis to form a rim 25 and a rear flange. I do.

Next, as shown in FIG. 13, the wheel 26 after the spinning process is stored in a heating furnace 36,
Heat treatment is performed at a predetermined temperature for about 12 hours.

Next, as shown in FIG.
After the jigs 37a and 37b are pressed against the wheel 26 by the robot to perform chamfering while attaching and rotating the rotary shaft 37 to the rotary shaft 37, letters or numbers are engraved.
Thereby, for example, the wheel shown in FIG. 15 is completed.
After that, it is shipped as a product after shipping inspection.

[0012]

However, the above-mentioned conventional method of manufacturing an aluminum wheel by forging has the following problems. That is, in the above-described conventional method, a spinning step is required to form the rim into a predetermined shape. In order to form the rim portion into a predetermined shape by the spinning process, usually about three passes are required, and the process requires a long time. For this reason, the product cost of the conventional forged wheel is about three times as high as that of the cast wheel.

[0013] The present invention has been made in view of the above problems, and a high strength and lightweight one-piece forged wheel can be manufactured without using a spinning process.
It is an object of the present invention to provide a method for manufacturing a light alloy wheel that can reduce product cost.

[0014]

According to the present invention, there is provided a method for manufacturing a light alloy wheel, comprising the steps of crushing a light alloy material and projecting it from a disk-shaped disk portion and a peripheral portion of the disk portion into a cylindrical shape. Forming a primary work material having a protrusion whose length is set in accordance with the length of the rim portion of the finished product wheel; and forging the primary work material so that the disk portion has a predetermined shape. A step of forming the rear flange portion by forming the end portion of the protruding portion by flaring to form a rear flange portion.

[0015]

In the method of the present invention, first, a material is processed by crushing to form a primary work material having a disk portion and a cylindrically projecting portion from the disk portion. In this case, the length of the protrusion is substantially the same as the length of the rim of the finished wheel.

That is, according to the present invention, a primary work material having a protrusion having a shape substantially equal to the rim portion of the finished product wheel is formed by crushing, and the disk portion of the primary work material is forged. After shaping the disk into a predetermined shape, the front end of the protrusion is bent by flaring to form a rear flange. This eliminates the need for the spinning step conventionally required for forming the rim portion and the rear flange portion, and can achieve a predetermined wheel shape in a short time. Therefore, according to the method of the present invention, the manufacturing cost of the light alloy wheel can be reduced as compared with the conventional method.

[0017]

Next, an embodiment of the present invention will be described with reference to the accompanying drawings.

1 to 5 are views showing a method of manufacturing a light alloy wheel according to an embodiment of the present invention in the order of steps.

First, as shown in FIG. 1, a billet 1 is obtained by cutting an aluminum alloy ingot to a predetermined size.

Next, as shown in FIG.
a, 11b is used to crush the billet 1 and
Next work material 2 is obtained. FIG. 7 is a perspective view showing the primary processing material 2. In this crushing process, the primary processing material 2
The thickness and length of the projection 2a are made substantially equal to the thickness and length of the rim of the finished wheel.

Next, as shown in FIG.
Forging work (roughing) on the primary work material 2 using a and 12b
Is performed to obtain the secondary processed material 3. Thereafter, as shown in FIG. 4, forging (finishing) is performed using the forging dies 13a and 13b to obtain a tertiary processed material 4. By this roughing and finishing forging, the disk portion is formed into a predetermined shape.

Next, as shown in FIG. 5, the tip of the protruding portion 2a of the tertiary product 4 is bent by flaring to form the rear flange 5 into a predetermined shape.

Next, after heat treatment and pickling,
The rim (projection) is cut and a valve seat is formed. Thereby, for example, a one-piece aluminum wheel having the shape shown in FIG. 6 is completed.

Conventionally, it has been considered difficult to manufacture, for example, a five-spoke type one-piece aluminum wheel as shown in FIG. 6 by forging. And forming a primary working material having a protrusion having a shape substantially equal to the rim portion of the finished product wheel, and forging the primary working material to manufacture a wheel. Wheels and even more complex shaped wheels can be easily manufactured. Further, according to the method of the present embodiment, the spinning step is not required, and the time required for manufacturing can be reduced to about 1/10 of the conventional method. Therefore, there is an effect that the product cost can be reduced as compared with the related art.

Furthermore, according to the method of the present embodiment, even in the case of wheels having different designs of disk portions, the primary working material formed by the same squeezing mold can be used as long as the wheels have the same size. It is also possible to reduce the cost of wheels for the aftermarket with the same design and a small quantity (market for general car owners, not for car manufacturers).

For convenience of design, a disc portion and a rim portion (protruding portion) are provided between the primary work material and the finished product wheel.
If the volume distribution of the primary processing material differs, the volume distribution of the primary processing material is made substantially equal to the volume distribution of the finished product wheel (ie, the disk of the primary processing material). (The volume ratio of the protruding part and the protruding part is made almost equal to the volume ratio of the disc part and the rim part in the finished product.)
Is preferred.

[0027]

As described above, according to the present invention, firstly, the primary working in which the disc portion and its protruding portion have a protruding portion set according to the length of the rim portion of the finished product wheel by crushing. After forming the material and forging the primary material, the end of the protruding portion is bent by flaring to form a rear flange portion, which has been conventionally required for manufacturing a one-piece forged wheel. A flaring step is not required, and the time required for manufacturing can be significantly reduced. Therefore, according to the method of the present invention, there is an effect that the product cost of the one-piece forged wheel can be reduced as compared with the related art.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one step of a method for manufacturing a light alloy wheel according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing one step of the manufacturing method.

FIG. 3 is a cross-sectional view showing one step of the manufacturing method.

FIG. 4 is a cross-sectional view showing one step of the manufacturing method.

FIG. 5 is a cross-sectional view showing one step of the manufacturing method.

FIG. 6 is a perspective view showing an example of a completed aluminum wheel.

FIG. 7 is a perspective view showing a primary processed material after crushing.

FIG. 8 is a perspective view showing one step of a conventional method of manufacturing an aluminum wheel by forging.

FIG. 9 is a cross-sectional view showing one step of the manufacturing method.

FIG. 10 is a cross-sectional view showing one step of the manufacturing method.

FIG. 11 is a cross-sectional view showing one step of the manufacturing method.

FIG. 12 is a plan view showing one step of the manufacturing method.

FIG. 13 is a plan view showing one step of the manufacturing method.

FIG. 14 is a plan view showing one step of the manufacturing method.

FIG. 15 is a perspective view showing an example of an aluminum wheel after completion.

[Explanation of symbols]

1, 21; aluminum alloy billet 2: primary work material 3: secondary work material 4: tertiary work material 5: rear flange 11a, 11b; crushing mold 12a, 12b, 13a, 13b, 31a, 31b, 3
2a, 32b, 33a, 33b; Forging die 35; Roller

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takumi Fujii 3-1-1 Kinjocho, Kita-ku, Nagoya-shi, Aichi Nagoya Works, Kobe Steel Ltd. (72) Inventor Keisuke Yamaguchi 3 Kinjocho, Kita-ku, Nagoya-shi, Aichi Prefecture Kobe Steel Co., Ltd. Nagoya Works, Kobe Steel Co., Ltd. (72) Koichi Ozaki 3-1-1, Kinjocho, Kita-ku, Nagoya City, Aichi Prefecture Kobe Steel Co., Ltd., Nagoya Works (56) References JP, A) JP-A-61-115640 (JP, A) JP-A-61-115641 (JP, A) JP-A-62-279047 (JP, A) JP-A-2-165835 (JP, A) JP-A-2-299733 (JP, A) JP-A-4-167943 (JP, A) Jpn.

Claims (1)

(57) [Claims] 1. A light alloy material is crushed to project in a cylindrical shape from a disk-shaped disk portion and a peripheral edge of the disk portion, and the length of the projection is set according to the length of a rim portion of a finished wheel. Forming a primary processed material having a projected portion formed thereon, forging the primary processed material to form the disk portion into a predetermined shape, and flaring the end of the projected portion. Forming a rear flange portion by bending according to the following method.