JPS6113045A - Manufacturing method of composite flywheel - Google Patents

Abstract

PURPOSE:To obtain a lightweight flywheel which has a large inertia force and can be easily prepared by preparing a flywheel through the process in which metal powder is uniformly distributed into synthetic resin. CONSTITUTION:Metal powder is distributed uniformly into synthetic resin by 70-90wt%, and molded integrally into disc form to obtain a flywheel 1. Thermo-setting resin is used as synthetic resin, and Fe, Zn, Sn, Pb, Cu, and the alloy thereof are used as metal powder. The molding of the flywheel 1 is carried-out by injection molding and press-molding. With such constitution, the inertia force of the flywheel 1 is large, in spite of small weight, and economical mass production is permitted through injection molding and press-molding.

Description

[Detailed Description of the Invention] <Object of the Invention> Industrial Field of Application The present invention relates to a composite flywheel, and more particularly, to a composite flywheel in which a large amount of metal powder is blended into a synthetic resin (hereinafter simply referred to as resin). Composite flywheels are extremely economical and can be mass-produced by injection molding, press molding, or other ordinary resin molding techniques, such as those used in recording and playback equipment that have a large inertial force and are uniformly dispersed. Pertains to.

Note that here, the recording and reproducing equipment refers to audio II1 equipment such as general tape recorders, home stereos, and car stereos, as well as computer terminal equipment and the like.

BACKGROUND OF THE INVENTION Conventionally, flywheels have been used in recording and reproducing equipment such as tape recorders to alleviate uneven feeding of magnetic tapes and the like.

These flywheels were generally manufactured by casting or forging metal with a large specific gravity, but those with a mouth structure required balance processing such as cutting and polishing after the molding process such as casting, making the manufacturing process extremely time-consuming. This is not only complicated, but also expensive.

From this point of view, the present inventors first developed a flywheel with a sintered structure in which the above-mentioned balancing process can be omitted and, unlike a cast structure, fine voids are uniformly distributed between metal powder particles. (Refer to Japanese Patent Publication No. 10698/1983). This flywheel can appropriately adjust wow and fluff by adjusting the void size, its distribution, the amount occupied, etc., and can be manufactured by powder metallurgy, so there is no need for balance processing such as cutting and polishing. In addition, this flywheel is excellent because it has extremely low wow and flutter values, but it is made entirely of expensive metal powder and manufactured using powder metallurgy, and the manufacturing process is complicated and requires high heat. Required.

Therefore, the price has become a major problem in flywheels for recording and playback equipment, where economic efficiency is important.

On the other hand, in recent years, audio equipment such as tape recorders has become smaller due to the development of electronic technology, and along with this, smaller flywheels are required, and due to advances in technology, the output of even small motors has increased. The tolerable limits for wow and flutter required for flywheels have been considerably relaxed compared to the past, and there is a desire for flywheels that are smaller and lower in cost.

In other words, as recording and playback equipment becomes smaller today, the wow and flutter required for it varies depending on the specifications of the equipment, but it is approximately 0.05 to 0.5%, and is lower than that of conventional equipment (,0.0%). , 15% or less is not necessarily required, and there is no necessity to use a flywheel produced by powder metallurgy.

In other words, while modern motors have become smaller, their output has become larger, and compared to the past, the requirements for wow and flutter on the flywheel have become less severe;
As tape recorders and the like, as exemplified by the Walkman, have become smaller and lighter, there has been an increasing demand for flywheels to be smaller, lighter, and more economical.

Problems to be Solved by the Invention The present invention aims to solve the above-mentioned drawbacks. Specifically, the present invention aims to solve the above-mentioned drawbacks. We propose a small composite flywheel that can be mass-produced by resin molding and has wow and flutter of about 0.05 to 0.5%.

<Structure of the Invention> Means for solving the problems and their effects, that is, the present invention provides metal powder with a weight percentage of 10 to 95%.
This metal powder is uniformly dispersed in the synthetic resin,
Moreover, it is characterized by having a specific gravity of 3.5 to 5.5 g/cn'.

The above structure and its operation will be specifically explained below with reference to FIGS. 1 and 2.

First, FIG. 1 is a sectional view of a flywheel according to one embodiment of the present invention, and FIG. 2 is an enlarged sectional view of a part thereof. In Fig. 1, reference numeral 1 indicates a flywheel, and this flywheel 1 is made by uniformly dispersing 70 to 95 wt% (hereinafter simply referred to as %) of metal powder in a synthetic resin and integrally molding it into a disk shape. It is what it is. That is, as shown in FIG. 2, the metal powder 2 is dispersed in the resin 3, increasing the specific gravity and the inertial force compared to the resin alone.

Although the shape of the flywheel does not necessarily have to be as shown in FIG. 1, normally, as shown in FIG. 1, a shaft hole 1a is formed in the center, and a rotating shaft 4 is mounted in this shaft hole 1a.

Furthermore, it is effective to make the mass as far away from the rotating shaft 4 as large as possible to largely cover the inertial force, and the rib portion 1b is usually made thick.

Although any synthetic resin may be used depending on the molding method, typical thermosetting resins include phenol resin, epoxy resin, polynisder resin, melamine resin, furan resin, diallyl phthalate resin, and thermosetting resin. Examples include polybutadiene resin.

Typical examples of thermoplastic resins include polyolefin resins, vinyl chloride resins, polyacetal resins, polyamide resins, and polycarbonate resins, but various copolymers and modified products of these resins are also included. From the viewpoint of viscosity, nylon is preferable.

Furthermore, the metal powders include Fe%Zn%Sn, Pb,...
Although Cu and its alloys are included, Fe powder is most preferred from the viewpoint of cost.

The particle size of the metal powder affects the physical properties of the flywheel; increasing the particle size will result in poor dispersion and loss of surface smoothness and surface gloss.

From this point of view, the thickness is preferably 150 μm or less. When the particle size is small, dispersibility improves and physical properties improve, but depending on the type of metal, the activity increases and gaseous substances are generated when the composition is melted and heated, which may cause a decrease in physical properties.
A particle size of μm or more is preferred.

Note that when resin and metal are mixed, a coupling agent,
Additives such as dispersants, stabilizers, fibrous reinforcements, etc. can be added.

Also, the amount of metal powder mixed has a specific gravity of 3.
5 to 5.5 g/c13, but in addition to this, when the raw materials are kneaded and sent in the mixer, for example, the inner wall surface of the outer box of the cylinder, screw, plaid, etc. There is a risk that the raw material will adhere to the stirring part of the stirrer, causing severe abrasion due to the large amount of metal powder in the raw material.

The more metal powder there is in the raw material, the more severe this adhesion and abrasion becomes.
From this point of view, the amount of metal powder blended is preferably 95% or less.

The lower limit of the amount of metal powder blended is 70%, which varies depending on the specific gravity of the metal powder, but in order to obtain the wow and flutter required for tape recorders and the like, it must be blended at 70% or more.

Next, the flywheel having the above structure can be molded by any method, but when molded by injection molding, it can be molded as follows.

That is, 70 to 95% metal powder and 5 to 30% thermoplastic resin are kneaded while being heated and melted, molded into pellets, and then the pellets are molded into a flywheel using injection acid. mold. In order to increase the inertial force of the flywheel, it is preferable to increase the blending ratio of metal powder and to improve its dispersibility, but it is extremely difficult to uniformly disperse and mix materials with large differences in specific gravity.

From this point of view, a flywheel is produced by first kneading metal powder and a thermoplastic resin to form pellets, melting these pellets, kneading them again, and injection molding them under high pressure.

In addition, when a thermosetting resin is used as the synthetic resin instead of injection molding as described above, the above pellets or a mixed powder of thermosetting resin and metal powder are press-molded into a flywheel as in the conventional method. can also be manufactured. In this case, there is no need to perform any cutting after molding, but it is necessary that the pellets or mixed powder be mixed uniformly.

Example Example 1 will be explained as follows.

Example 16 Iron powder and lead powder were mixed with nylon resin, and silane coupling agent A-1100f (Nitto Unicar Co., Ltd.) was added to these.
(manufactured by J.D. Co., Ltd.), these were heated at a temperature of 250° C. to melt them, cross-wired while applying pressure, and after cooling, they were crushed and molded into various pellets with diameters of about 3 ml and 1 φ. After drying these pellets, use a screw injection molding machine at a cylinder heating temperature of 255°C, a mold temperature of 80°C, and an injection pressure of 850k.
A flywheel having the shape shown in FIG. 1 was molded using q/ct'.

The relationship between the amount of metal powder blended and the specific gravity of these flywheels was found as shown in Figure 3.Among these flywheels, those with a specific gravity of 3.8 to 4.5Q/@' had a wow/black of 0. It was about .2 to 0.3, and the iron powder was uniformly dispersed throughout.

In Fig. 3, the symbol (a) indicates a product containing iron powder, and the symbol (b) indicates a product containing lead powder.

Example 2 Iron powder (average particle size 53
μm 170 parts by weight and silane coupling agent A-17
4f Nitto Unicar product) was mixed, and this mixture was placed in a press mold and heated while applying pressure to produce a flywheel having the shape shown in FIG. When this flywheel was examined for dispersibility of iron powder, it was found to be as good as in Example 1.

<Effects of the Invention> As explained in detail above, the present invention allows metal powder to be uniformly dispersed in a synthetic resin, and has a specific gravity of 3.5 to 4.5o.
/cr flywheel. Therefore, despite being uniformly and highly filled with metal powder and being lightweight, it has inertia.
It can be manufactured economically in large quantities by injection molding or press molding.

In addition, if a synthetic resin is interposed between metal powders by press molding or injection molding of mixed powder, and fine pores are interposed around and between these, these pores and metal powder Appropriate wow and flutter can be obtained by the distribution of .

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of a flywheel according to one embodiment of the present invention, Fig. 2 is an enlarged view of a part of Fig. 1, and Fig. 3 is a graph showing the relationship between the amount of metal powder not mixed and specific gravity. It is. Code 1... Flywheel 2... Metal powder 3... Resin 111 Figure 2 Figure 3 Resin

Claims (1)

[Claims] Contains 70-95% metal powder by weight, the metal powder is uniformly dispersed in the synthetic resin, and has a specific gravity of 3.5.
A composite flyfoil characterized by comprising ~5.5g/cm^3.