JPH06154998A - Manufacture of fly wheel integrated with gear - Google Patents

Abstract

PURPOSE:To improve the strength of fitting part in a fly wheel and to reduce the weight of the fitting part. CONSTITUTION:A core 4 having grooves 8 engraved radially toward the outer peripheral of a cavity 3 is provided in the cavity 3 of a forming mold 1, 2, and after arranging a spheroidal treating agent 9 composed of Fe-RE alloy at the center part of the core 4, molten metal composed of CV graphite cast iron is poured into the cavity 3. A gear A composed or spheroidal graphite cast iron is formed at the outer-most peripheral part in the cavity 3 and also, the fly wheel B composed of the CV graphite cast iron is formed at the inner peripheral side of the gear A to manufacture the fly wheel integrated with gear.

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 flywheel integrated with gears.

[0002]

2. Description of the Related Art Heretofore, as a method of manufacturing a flywheel with a built-in gear, a method disclosed in Japanese Patent Laid-Open No. 3-5055 has been known. This is because the Fe in the mold cavity is located in the center of the lower mold.
-Si-Mg-based spheroidizing agent is placed, and then a molten metal made of gray cast iron (FC) is injected into the cavities while rotating the molding mold, and the reaction between the molten metal and the spheroidizing agent is centrifuged. It was diffused toward the outer peripheral side of the cavitation by force. As a result, a gear made of spheroidal graphite cast iron (FCD) is formed at the outermost peripheral portion in the cavitation, and the CV graphite cast iron (FC
V) flywheel sliding part, gray cast iron (F
The mounting portion of the flywheel made of C) was intended to be inclined.

[0003]

However, the above-described method of manufacturing the gear-integrated flywheel has the following problems.

Since gray cast iron (FC) has a small tensile strength, the strength of the mounting portion of the flywheel made of gray cast iron becomes small. As a result, it is necessary to increase the wall thickness of the attachment portion of the flywheel, which increases the weight of the flywheel.

Since the Fe-Si-Mg-based spheroidizing agent is used, impurities are generated by the reaction when the rotational force of the mold, that is, the centrifugal force, is not applied in a predetermined amount, and the impurities remain in the cavities to produce the product. Is likely to have defects.

Since centrifugal casting is performed, the equipment cost is high.

Therefore, the present invention has as its technical problem the solution of the above problems.

[0008]

[Constitution of the invention]

[0009]

In order to solve the above technical problems, the technical measures taken in the present invention have a groove radially formed in the cavity of a molding die in the outer peripheral direction of the cavity. After setting the core and arranging the spheroidizing agent made of Fe-RE alloy in the center of the core,
A spheroidal graphite cast iron, which is lightly spheroidized, is poured into the cavities to form a gear made of spheroidal graphite cast iron in the outermost peripheral portion of the cavities and CV graphite cast iron on the inner peripheral side of the gears. Is to form a flywheel.

[0010]

The operation of the above technical means is as follows.

Since the molten metal subjected to a mild spheroidizing treatment which is less than that of spheroidal graphite cast iron is injected into the cavities to form CV graphite cast iron having a higher tensile strength than gray cast iron, the flywheel mounting portion (inner portion) Strength is improved. As a result, the mounting portion of the flywheel can be made thinner, and the weight can be reduced.

Since the spheroidizing agent made of Fe-RE alloy is used, and the grooves radially formed toward the outer peripheral direction of the cavities are formed in the core, its reaction product, that is, spherical graphite ( FCD) is preferentially and reliably dispersed toward the outer circumference of the cavitation. As a result, the gear is formed entirely of spheroidal graphite.

Since the spheroidizing agent made of the Fe-RE alloy is used, it becomes difficult for impurities to be generated by the reaction between the Fe-RE alloy and the molten metal, and product defects due to the impurities are reduced without applying centrifugal force. can do.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a sectional view of a casting apparatus used in the method for manufacturing a gear-integrated flywheel according to this embodiment.
FIG. 2 is a plan view of the casting apparatus excluding the upper mold.
FIG. 4 is a cross-sectional view of the gear-integrated flywheel according to the present embodiment, and FIG. 4 is a structural diagram of the gear-integrated flywheel of FIG. 3.

As shown in FIG. 1, the casting apparatus 10 comprises:
The mold is composed of an upper mold 1 and a lower mold 2. Here, a sand mold is used for the upper mold 1 and the lower mold 2. A cavity 3 is defined by the upper mold 1 and the lower mold 2, and an injection port 5 for flowing molten metal is provided in the upper mold 1.
Are formed. A core 4 is arranged inside the cavitation 3, and the cavitation 3 is substantially divided into a reaction chamber 6 located below the inlet 5 and an outer peripheral chamber 7. As shown in FIG. 2, the core 4 is formed with three grooves 8 radially toward the outer peripheral direction of the cavitation 3.
Forms an angle of about 45 ° with respect to the axis, and the depth and width are 15 mm and 20 mm, respectively.

At the center of the core 4, a spheroidizing agent 9 made of Fe-RE alloy is arranged.

A method of manufacturing the gear-integrated flywheel according to this embodiment will be described.

A core 4 having grooves 8 radially engraved toward the outer periphery of the cavitation 3 is installed in the lower mold 2, and a spheroidizing agent 9 made of Fe-RE alloy is provided in the center of the core 4. After the placement, the upper mold was placed. Here, the spheroidizing agent 9 made of Fe-RE alloy was adjusted to 0.009 wt%.

Next, the molten metal was prepared as follows. CV
Weight ratio of graphite cast iron (FCV) return material and steel scrap is 6: 4
Melt 20 kg of the material mixed in
0.8 wt% Cu and Fe-Mn alloy is added to this 0.8
It was added so as to be wt% Mn. By adding these alloys, the hardenability of the gear, the sliding characteristics, and the strength of the mounting portion of the flywheel are improved. Then 15
Fe-Si and the above materials in a ladle at a melt temperature of 00 ° C.
-Mg and Fe-Si were reacted. In this way, the molten metal was adjusted by performing a mild spheroidizing treatment that was less than that of spheroidal graphite cast iron.

The molten metal prepared as described above was gradually injected into the reaction chamber 6 of the cavitation 3 through the injection port 5. Here, the injection time of the molten metal was set to 10 seconds. As a result, C
In the reaction chamber 6, the molten metal composed of V-graphite cast iron was added to the Fe-RE.
Spheroidal graphite (FC
D) is generated and the spherical grooves (FCD) are rapidly dispersed toward the outer peripheral direction in the cavity 3 by the radial grooves 8 formed in the core 4, and the spherical graphite (FCD) is distributed to the outer peripheral portion of the cavity 3 via the outer peripheral side chamber 7. Move evenly. Therefore, as shown in FIGS. 3 and 4, a gear A made of completely spherical graphite (FCD) is formed on the outer peripheral portion of the cavitation 3. Gear A
The heat treatment was performed by induction hardening and tempering. Here, the quenching conditions are a frequency of 400 kHz and an electric power of 240 V.
× 110A, heating time 17s, cooling time 10s,
The tempering condition is 190 ° C. × 2 h. Further, since the spheroidizing agent disappears during the injection of the molten metal, the content of the molten metal made of CV graphite cast iron gradually increases toward the axial center. Therefore, as shown in FIGS. 3 and 4, the flywheel B made of almost worm-shaped CV graphite cast iron is formed.

Table 1 shows the characteristics of the gear-integrated flywheel 11 manufactured by the manufacturing method according to the present embodiment and the gear-integrated flywheel manufactured by the conventional manufacturing method.

As can be seen from Table 1, the tensile strengths of the gear A and the flywheel B according to this embodiment are higher than those of the prior art.

[0024]

[Table 1]

[0025]

The present invention has the following effects.

The strength of the attachment portion of the flywheel is improved. As a result, the mounting portion of the flywheel can be made thinner, and the weight can be reduced.

Impurities are less likely to be generated by the reaction, and product defects do not occur.

Cost is reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a casting device used in a method for manufacturing a gear-integrated flywheel according to this embodiment.

FIG. 2 is a plan view of the casting apparatus excluding the upper mold.

FIG. 3 is a sectional view of a gear-integrated flywheel according to the present embodiment.

FIG. 4 is a structural diagram of the gear-integrated flywheel of FIG.

[Explanation of symbols]

 1 Upper mold (molding mold) 2 Lower mold (molding mold) 3 Cavity 4 Core 8 Groove 9 Spheroidizing agent 11 Gear integrated flywheel

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical indication location F16F 15/30 V 9030-3J (72) Inventor Masuo Yamada 2-chome, Asahi-cho, Kariya city, Aichi prefecture No. 1 Aisin Seiki Co., Ltd. (72) Inventor Koichi Chikusa 2-1, Asahi-cho, Kariya City, Aichi Prefecture Aisin Seiki Co., Ltd. (72) Tsutomu Kuri, Tenno, Takaoka Shinmachi, Toyota City, Aichi Prefecture Aisin Takaoka Co., Ltd. (72) Inventor Norihiro Akita No. 1 Tenno, Takaoka Shinmachi, Toyota City, Aichi Prefecture Aisin Takaoka Co., Ltd.

Claims (1)

[Claims] 1. A method of casting an integrally molded product of a gear and a flywheel in a molding mold, comprising: a groove formed in a cavity of the molding mold in a radial direction toward an outer peripheral direction of the cavity. A spheroidizing agent made of Fe-RE alloy is placed in the center of the core, and a molten metal subjected to a mild spheroidizing treatment less than that of spheroidal graphite cast iron is injected into the cavities. A gear-integrated flywheel, characterized in that the gear made of spheroidal graphite cast iron is formed on the outermost peripheral portion in the cavitation, and the flywheel made of CV graphite cast iron is formed on the inner peripheral side of the gear. Method.