JPS6187286A - Tape cassette and cassette mechanism parts - Google Patents

Abstract

PURPOSE:To improve an acoustic characteristic by molding an inorganic filler with a nylon resin which is filled at the special volume filling rate. CONSTITUTION:An inorganic filler is molded by a nylon resin which is filled to 25%-55% at a volume filling rate. Thus, an elastic modulus is improved, a bending rigidity becomes large, a deflection oscillation is prevented, resonance sharpness is lowered, the vibration of tape mechanism parts can be absorbed and since the density is increased, the oscillating energy is absorbed and the acoustic characteristics of a modulating noise, phase, etc., can be improved.

Description

[Detailed Description of the Invention] [Industrial Field of Application] A tape cassette in which the tape-shaped magnetic recording medium (hereinafter referred to as magnetic tape) of the present invention is wound around a reel and the reel is housed therein, and the cassette thereof Regarding cassette mechanism parts built into.

[Conventional technology]

This type of tape cassette is made of a molded synthetic resin such as high-impact styrene resin, ABS resin, or AS resin, but recently, magnetic recording media are made of metal magnetic powder and are capable of short wavelength recording. As tape cassettes have become easier to manufacture, stricter demands have been placed on dimensional accuracy and acoustic properties.

In response to this requirement, tape cassettes molded from a single resin such as ABS resin, which is commonly used, may deform when the operating temperature range exceeds 40°C, especially in tape pass systems. The tape tension changes due to the deformation of the mechanical members involved, and this causes vibrations in the tape path system mechanical members due to tape friction fluctuations, and the cassette half itself also suffers from vibrations from the t side. The vibration caused by the transmission causes the tape to vibrate, resulting in a problem of deteriorating acoustic characteristics such as modulation noise and phase.

Therefore, in order to eliminate this drawback,
As disclosed in Japanese Patent No. 85, the impact strength of the tape cassette is improved by molding the upper and lower halves of the tape cassette using a composite resin material in which 30 to 70% 1t% of inorganic filler is filled in a polypropylene resin. Materials with improved heat resistance and the like have been proposed.

[Problem that the invention seeks to solve]

The present invention aims to further improve the characteristics of the tape cassette disclosed in the above-mentioned Japanese Utility Model Publication No. 167085/1985.

[Means for solving problems]

That is, in the present invention, the tape cassette and the cassette 7) mechanical parts are molded from a nylon resin filled with an inorganic filler at a volumetric filling rate of 25% to 55%.

As the inorganic filler used in the present invention, powdery and fibrous fillers are used as shown below.

This powdered inorganic filler includes carbonic acid, lucium (CaCO3), talc (3Mgo・4sio2・H2
O), glass peas, aluminum hydroxide, magnesium hydroxide, diatomaceous earth, silica, flake, kaolin (Al2
O3・2Sio2・2H20), sulfuric acid JJ Lamb (
BaSO4), titanium oxide, carbon blank, metal powder, graphite, shirasu balloon, potassium titanate, wollastonite, asbestos, mica, glass, Al2O3
・5t02, Al2O3, SiC% ZrO2, Zn0
STic %5iJ4% 5tO2, MgO, calcium titanate, Cr2L, α-Fe203, mullite (3
^1203 ・2Si(h), forsterite (2Mg0・5iO2), stearite (MgO-5
tO2), zircon (Zr02・5iO2), cordierite (2Mg0・2^1203・5SiO2
), BN, aluminum nitride (^IN), sialon (Si
3N4 ・^1203), aluminum silicate, gypsum (Ca
SO4) etc. can be used.

In addition, fibrous inorganic fillers include glass fiber, carbon fiber, alumina fiber, boron fiber, silicon carbide fiber,
Metal fibers, high silica fibers, zirconia fibers, etc. can be used.

Note that a mixture of powdered and fibrous inorganic fillers may be used as the inorganic filler.

[Effect]

The tape cassette and cassette mechanism parts of the present invention formed in this way have an improved elastic modulus and a large bending rigidity, which prevents flexural vibration and reduces resonance sharpness to absorb vibrations of the tape mechanism parts. In addition, the increased density absorbs vibration energy and improves acoustic characteristics such as modulation noise and phase.

〔Example〕

A tape cassette applied to embodiments of the present invention to be described later will be described with reference to the drawings.

This tape cassette includes a cassette casing Q[I. The casing 0ω is composed of a pair of upper and lower halves (11) and (12) made of synthetic resin, and by joining these halves to each other and connecting them with screws, a flat rectangular parallelepiped-shaped casing aω can be assembled. There is. A pair of reels (13) and (14,) are arranged inside this casing α0), and these reels (13) and (14) are engaged with an annular protrusion (28) formed on the casing α0). With both ends of the magnetic tape (15) fixed to these reels (13) and (14), the magnetic tape (15) is attached to the reels (13) and (14).
). This reel (13).

The magnetic tape (15) housed in the casing aω is wrapped around the magnetic tape (14) and is connected to a pair of guide rollers (16).
and guide pin (17) and central guide block (1
8), the hook is passed along the tape path formed on the front side of the casing α0. The guide block (18) is the casing (10)
The tape guides (18a), (18b), (18c) are constructed separately from the tape guides (18a), (18b), and (18c).
The head insertion port (21) and the pinch roller insertion port (22) are arranged inside the front wall portion of the casing aω, in which the head insertion port (21) and the pinch roller insertion port (22) are respectively formed. In addition, the guide block (18) has a pair of circular protrusions (top and bottom).
29) are formed, and these protrusions (29) are adapted to be engaged with circular holes (30) formed in the cassette halves (11) and (12), respectively, so that the cassette casing The guide block (18) is held in position correctly within αω.

In this way, the tape guide of the guide block (18) <1
The magnetic tape (15) guided by 8a), (18b), and (18c) is pushed toward the front side by a felt pad (25) held on the shield plate (23) via a temporary spring (24). This allows it to come into contact with the magnetic tape inserted from the head insertion port (21). And magnetic tape like this (
Reel (13) to make the running of 15) smoother.
Smooth sheets (26) are placed on the top and bottom of (14), respectively, and have protrusions (27) on their surfaces, and these protrusions (27) elastically attach the magnetic tape (15) ) is pressed against the widthwise end of the magnetic tape (15), thereby allowing the magnetic tape (15) to run smoothly.

And the above pair of cassette halves (11), (1
2) and the guide rod (18) formed separately from this are molded from nylon resin filled with inorganic filler.

A specific example of this nylon resin, that is, a composite resin material will be described, but it goes without saying that the present invention is not limited to this example.

Example 1 Volume ratio aluminum silicate (Al2O3・5i02) 5
1% zinc oxide (ZnO) 6% nylon = 1243% A cassette half was formed by injection molding using a composite resin material in which the above composition was mixed.

Example 2 Volume ratio aluminum silicate (81203 ・5t02)
16% zinc oxide (ZnO) 33
% Nylon-1251% A cassette half was formed by injection molding using a composite resin material mixed with the above composition.

Example 3 Volume percentage zinc oxide (ZnO) 45% nylon-1255% A cassette half was formed by injection molding using a composite resin material in which the above composition was mixed.

Example 4 Volume ratio aluminum silicate (Al2O2・5i02) 1
1% Zinc oxide (ZnO) 14%
Nylon-685% A cassette half was formed from a composite resin material mixed with the above composition by injection molding.

Example 5 Volume ratio aluminum silicate (81203/5i02)
34% calcium carbonate (CaCO3) 2
A cassette half was formed by injection molding using a composite resin material in which the above composition of 2% nylon-644% was mixed.

Comparative example 1 Volume ratio aluminum silicate (Al2O3・5i02) 1
A cassette half was formed by injection molding using a composite resin material containing 9% zinc (Zn), 3% polypropylene, and 78% of the above composition.

Comparative Example 2 A cassette half was formed from nylon-66 by injection molding.

Comparative Example 3 A cassette half was formed from nylon-6 by injection molding.

Comparative Example 4 A cassette half was formed from nylon-12 by injection molding.

Comparative Example 5 A cassette half was formed by injection molding using HIPS (high impact styrene resin) (conventional product).

Comparative Example 6 A cassette half was formed from cpps resin by injection molding.

Comparative Example 7 A cassette half was formed from ABS resin by injection molding (conventional product).

Comparative Example 8 A cassette half was formed from AS resin by injection molding.

Comparative Example 9 A cassette half was formed from PET resin by injection molding.

Comparative Example 10 A cassette half was formed from polycarbonate by injection molding.

The density, elastic modulus, and resonance sharpness of each of the cassette halves formed in the above Examples and Comparative Examples were measured. These results are as shown in the table below.

As is clear from the results in this table, Examples 1 to 5
The cassette half has a high elastic modulus, which increases bending rigidity and prevents flexural vibration, and also reduces resonance sharpness and allows it to absorb vibrations of cassette mechanism parts such as tape guides. At the same time, the density can be increased to absorb vibration energy, and therefore, the cassette half according to this embodiment can improve acoustic characteristics such as modulation noise and phase.

Taking all of these characteristics into consideration, it is desirable to construct the cassette half or cassette mechanism component with a nylon resin filled with an inorganic filler at a volumetric filling rate of approximately 25% to 55%.

Cassette halves made of such composite resin materials have an elastic modulus of 3.0 to 9.0 x 109 N/n.
(It is preferable that the resonance sharpness is within the range of 8.0 to 45 and the density is 1.5 to 3.OTON/r&.

〔Effect of the invention〕

As described above, the tape cassette and cassette mechanism parts according to the present invention contain inorganic filler at a volumetric filling rate of 25% to 55%.
Molding with filled nylon resin increases bending rigidity, reduces vibration amplitude, reduces resonance sharpness, and absorbs vibration, and increases density to absorb vibration energy. Even if external vibrations are transmitted due to the rotation of the tape cassette device's motor, or even if the tape guide, which is a cassette mechanism component, vibrates due to frictional sliding contact of the tape, the vibration energy will be absorbed. As a result, there is no effect of vibration on the magnetic tape, and by improving the rigidity of the tape cassette itself, there is no deformation due to heat, etc., and acoustic characteristics such as modulation noise and phase can be improved. has.

Furthermore, it is clear that the present invention is not limited to audio tape cassettes, but can also be applied to video tape cassettes.

[Brief explanation of drawings]

The figure is an exploded perspective view showing a tape cassette applied to an embodiment of the present invention. In the figure, α [ is the cassette casing, (11), (1
2) is a cassette half, (15) is a magnetic tape, (18)
) is the guide block 07, (18a), (18b)
, (18c) is a tape guide.

Claims (1)

[Claims] A tape cassette and a cassette mechanism component, characterized in that they are formed of a nylon resin filled with an inorganic filler at a volumetric filling rate of 25% to 55%.