JPS62215146A - Flywheel - Google Patents

Abstract

PURPOSE:To obtain a flywheel suited to mass production using an ordinary resin injection molder by forming a resin composition with a high specific gravity containing more than 70wt% metal powder, into said flywheel. CONSTITUTION:Resins used are nylons 11, 12 and their copolymers with their melt indexes being 35-100g/10min. As for metal powders, the powders of iron, zinc, copper, etc. and their oxides are used, and a round-shaped particle of powder is preferable to a square-shaped one. A square-shaped particle not only deteriorate the fluidity of materials but also it liable to wear a device for manufacturing a molded object. A grading of 0.1-300mu is desirable for the metals powder, with the quantity of composition being 75-95wt% of a polyamide resin composition. Further, a stabilizer, a lubricant, a coupling agent, etc. may be appropriately added as necessary to improve the operation of a molding process. These materials are molded by injection molding to manufacture a flywheel.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a flywheel, particularly a flywheel used for a flywheel in a magnetic tape recorder or a turntable in a record player. More specifically, the present invention relates to a flywheel molded from a high-density polyamide resin containing metal powder.

[Conventional technology and problems]

As is well known, a flywheel is used to provide smooth rotation. In order to provide smooth rotation using inertial force, the same mass is required at the same distance from the central axis. If there is any variation in distance or mass, it will appear as wobbling of the central axis and uneven rotation, which will be a fatal defect for the flywheel. By increasing the inertial force, smoother rotation can be obtained. Therefore, it is necessary to increase the distance from the center or increase the mass. However, if the distance from the central axis is increased, the flywheel itself becomes larger and occupies a larger space, which is not preferable because the device in which the flywheel is built becomes larger. Therefore, it is desirable to increase the inertia force by making the distance from the central axis as small as possible and increasing the outer peripheral mass.

Such flywheels are used in most rotating devices, including recording and reproducing devices such as tape recorders, computer terminal devices, and the like.

Traditionally, flywheels have been made by casting or forging metals with high specific gravity, such as iron. However, when these products are actually used, they must be cut and processed to achieve balance, which increases the manufacturing price and also causes poor production efficiency.

In particular, it has become difficult to keep up with the recent increase in the production of audio equipment, as well as the trend toward higher quality and smaller size.

[Problem that the invention seeks to solve]

The purpose of the present invention is to meet the above-mentioned economic and quality requirements for flywheels, and by molding a high specific gravity resin composition containing metal powder into a flywheel, it is possible to create a flywheel by molding it into a flywheel. The purpose is to obtain a flywheel suitable for mass production using an injection molding machine.

[Means for solving problems]

That is, the present invention uses nylon 610.612. The present invention relates to a flywheel formed by molding one or more polyamide resin compositions selected from No. 11, No. 12, and copolymers thereof. In particular, metal powder having a particle size of preferably 150 tt m or less for nylon 11 and nylon 12 or copolymers thereof,
Preferably, a resin molded product obtained by molding a resin composition blended with iron powder is used as the flywheel.

When injection molding a resin composition containing metal powder and using it as a flywheel, the first problem is the characteristics of the molded product obtained. That is, in order to make the specific gravity high, it is sufficient to increase the metal powder content, but as the metal powder content increases, the strength of the molded product decreases. Therefore, it is necessary to select a resin that does not impair the strength of the molded product as much as possible even when the metal content is increased. Furthermore, as a matter of course, since injection molding is performed, deterioration in moldability must be avoided. The present inventors have developed nylon 610.612. as a resin that can meet such requirements. 11,
12 and their copolymers were found. It is difficult to achieve the above object of the present invention with other resins.

That is, styrene resin (polystyrene, As resin, A
, BS resin, etc.), the strength decreases significantly when metal powder is contained, and a material with high specific gravity cannot be obtained. PP
With E resin and polycarbonate resin, moldability (fluidity) is significantly inhibited.

1 as a resin that can provide high metal powder filling and good moldability
Possible examples include polyolefin resins and polyamide resins.

However, polyolefin resins have problems with heat resistance, and among polyamide resins, nylon 6
Alternatively, when nylon 66 is used as the resin component, cranking occurs with a small number of repetitions when thermal history (100°C←→-40°C) is performed.

The present inventors have discovered that nylon 610.612 has excellent dimensional stability, that is, low water absorption, and excellent strength retention.
．． 11, 12 Furthermore, we have found that these copolymers are desirable.

In particular, as the polyamide to be used in the present invention, nylon 11.12 and copolymers thereof are preferred.

The polyamide resin used in the present invention has a melt index (MI value) (temperature 230°C, load 2.
16 kg) is preferably 20 g/10 minutes or more, more preferably 35 to 100 g/10 minutes.

In addition, metal powders include Fe5Zn, Sn, and PbSC.
Powders of u, its alloys, oxides, etc. are used, but iron powder is most preferred from the point of view of price.Furthermore, in addition to resin and metal powder, a silane coupling agent, etc. corresponding to these properties may be added. You can also do it.

The metal powder used in the present invention may be obtained by any method. The shape of the metal powder may be any shape, but
It is preferable to use something close to a spherical shape rather than an angular metal powder. Square metal powder not only deteriorates the fluidity of the material, but also
Equipment used to obtain resin compositions or molded products is likely to be worn out.

The metal powder may have a particle size of 0.1 to 300μ, preferably 0.1 to 200μ, more preferably 0.1 to 50μ. If the particle size is smaller than 0.1μ, it is inconvenient to handle;
If it is larger, moldability will be inhibited.

The amount of these metal powders in the polyamide resin composition is 70% by weight or more, preferably 95% by weight or less.

The method of obtaining the molded product according to the present invention is to carry out injection molding using the granulated product obtained by kneading and extruding a resin component and metal powder in advance, or to charge the resin component and metal powder into an injection molding machine and then A method of obtaining a molded product can also be used.

Specifically, the polyamide component according to the present invention and metal powder are blended together, and the polyamide according to the present invention is prepared in the form of granules or powder, and the metal powder is mixed with this. After that, it is put into the extruder hopper and heated and melted and mixed to make granules. Alternatively, the premixed material is put into a Nigu and kneaded, and when the kneading is completed, the material discharged from the discharge port is cut or pulverized. A method of granulating, or a method of using an extruder, charging the polyamide according to the present invention from a part of a hopper, heating and melting it, and adding metal powder through an opening provided in the middle part of the cylinder of the extruder and mixing. There is.

The flywheel of the present invention can be obtained by further molding the pellets thus obtained by injection molding, extrusion molding, or the like.

Moreover, instead of such two-stage molding, a molded product of a flywheel can also be obtained by charging metal powder and polyamide into a molding machine.

Further, when manufacturing the flywheel of the present invention, the polyamide resin composition of the specimen invention that is integrated with the rotating body can be molded around the rotating body of a suitable material.

In addition, when obtaining a flywheel by resin molding as described above, stabilizers, lubricants, colorants, Dispersants, plasticizers, coupling agents, etc. can be blended into the resin composition.

〔Example〕

Next, the present invention will be explained with reference to Examples and Comparative Examples.

Examples 1 to 2 and Comparative Example 1 As the polyamide, Daicel Huels product name [Diaamide J L-1600 (230°C, MI value near 1 at 2.16 kg) was used, and as the iron powder, Kobe Steel's Product name: [Atmel J M2O3-200 was used.

The surface of the iron powder was treated with a coupling agent to prevent rust and maintain characteristic values. As a coupling agent, Ajinomoto's titanate coupling agent "Plenact J"
KR-TTS was used in an amount of 1 part by weight per 100 parts by weight of iron powder.

The polyamide for comparison was nylon 6 with a number average molecular weight of 34,000 obtained by polymerizing ε-caprolactam.
was used.

Table 1 shows the formulation of the resin composition and the test results when the resin composition was injection molded into a flywheel.

Table-1

Claims (1)

[Claims] Nylon 610, 612 containing 70% by weight or more of metal powder
A flywheel formed by molding one or more polyamide resin compositions selected from , 11, 12, and copolymers thereof.