JP2001349370A - Viscous fluid seal type damper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a viscous fluid seal type damper to prevent contact of the agitation part of the viscous fluid seal type damper with a cylindrical part and a cover even when an optical disc device is widely moved and prevent breakage of the agitation part. SOLUTION: In the viscous fluid seal type damper formed that viscous fluid is sealed in an internal space formed by the agitation part, the cylindrical part, and a flexible part to interconnect the agitation part and the cylindrical part, and the cover, the viscous fluid in type damper has an elastic resistor being situated in the internal space.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a viscous fluid-filled damper which is a vibration damping device for attenuating external vibrations in audio equipment and information equipment using an optical disk or the like.

[0002]

2. Description of the Related Art Compact disks are used in vehicles such as automobiles.
When an optical disk device such as a mini disk is mounted, when the vibration of the vehicle that occurs during traveling is transmitted to the optical disk device, the position of the beam emitted from the optical pickup lens shifts, and sound skipping easily occurs. Therefore, vibration is attenuated by supporting the optical disk device via a viscous fluid-filled damper.

As shown in FIG. 4, a conventional viscous fluid-filled damper includes a stirring section 3, a cylindrical section 7, and a rubber-like elastic body connecting the stirring section 3 and the cylindrical section 7. In the viscous fluid 2 sealed in the internal space formed by the container body 1 constituted by the flexible portion 6 and the lid 5, the agitating portion 3 into which a shaft projecting from the optical disk device is inserted moves. The external vibration is attenuated by viscous flow resistance caused by the vibration.

FIG. 3 shows a mounting example of a viscous fluid-filled damper.
An example is shown below. This is a typical arrangement relationship among an optical disk device 9, a viscous fluid-filled damper 10, a coil spring 11, and a housing 12, which are mounted on a vehicle-mounted device or the like. In FIG. 3, the optical disk device 9 suspended by the coil spring 11 is supported via the shaft 4 projecting downward, but the viscous fluid-filled damper 10 is supported via the shaft projecting laterally of the optical disk device 9. The configuration supported by may be used. The moving distance of the optical disk device 9 varies depending on the frequency band and acceleration of external vibration, but the maximum value is a constant space in each three-dimensional direction formed by the optical disk device 9 and the housing 12.

[0005]

However, when the optical disk device is largely moved by an impact action or the like, the viscous fluid-filled damper has a stirrer in which the shaft is inserted comes into contact with the cylindrical portion or the lid, and the stirrer has a stirrer. Was sometimes worn or damaged. Then, the enclosed viscous fluid flows out,
There has been a problem that the optical disk device is soiled and the damping action is reduced.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and the stirring portion of a viscous fluid-filled damper contacts a cylindrical portion or a lid even when an optical disk device is largely moved. The present invention provides a viscous fluid-filled damper that aims to avoid the agitation and to avoid any damage to the stirring section. It is another object of the present invention to provide a viscous fluid-filled damper capable of reducing the resonance magnification of the damper in a low frequency band where the amplitude is large and reducing the transmissivity even in a high frequency band where the amplitude is small.

That is, a viscous fluid in which a viscous fluid is sealed in an inner space formed by a container body including a stirring portion, a cylindrical portion, a flexible portion connecting the stirring portion and the cylindrical portion, and a lid. The fluid-filled damper is a viscous fluid-filled damper in which an elastic resistor is disposed in an internal space. Further, the viscous fluid-filled damper has a resistor disposed so as to cover the stirring section. Further, the resistor is a viscous fluid-filled damper filled in the internal space.
Further, the resistor is a viscous fluid-filled damper that is a foam. Further, the resistor is a viscous fluid-filled damper made of an open-cell foam.

[0008] The resistor of the present invention may have elasticity, but a resistor made of an open-cell foam is particularly preferable. In addition to the viscous flow resistance caused by the movement of the agitating section due to external vibration, the hole of the resistor made of foam acts as an orifice, and the damping force can be further increased by the resistance force when the agitated viscous fluid passes through. While the damping force due to viscous resistance is proportional to the speed, the damping force due to the resistance when passing through the orifice is proportional to the square of the speed. In this case, the resonance factor of the damper can be kept low, and the transmissivity can be reduced even in a high frequency band where the amplitude is small, so that good vibration isolation characteristics can be obtained.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A viscous fluid-filled damper of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view of an embodiment of the viscous fluid-filled damper of the present invention. The viscous fluid-filled damper of the present invention comprises a container body 1
Is a stirring section 3, a cylindrical section 7, the stirring section 3 and the cylindrical section 7
And a flexible portion 6 made of a rubber-like elastic body, and a resistor 8 is provided so as to cover the periphery of the stirring portion 3. By being attached around the stirrer, even if the stirrer swings greatly, it avoids direct contact with the cylindrical part and the lid, and the resistor absorbs shock to reduce wear and breakage of the stirrer. To prevent.

The resistor of the present invention may have elasticity, but the material is not particularly limited, and examples thereof include silicone rubber, polyurethane rubber, chloroprene rubber, butyl rubber, ethylene propylene rubber, and natural rubber.

The flexible portion of the present invention is preferably a rubber-like elastic body, and is appropriately selected from known synthetic rubbers and thermoplastic elastomers. For example, synthetic rubber includes styrene butadiene rubber, butadiene rubber, chloroprene rubber, nitrile butadiene rubber, butyl rubber, halogenated butyl rubber, ethylene propylene rubber, urethane rubber, silicone rubber,
Fluoro rubber, acrylic rubber and the like, thermoplastic elastomers, styrene-based, olefin-based, urethane-based,
Ester type, vinyl chloride type and the like can be mentioned. A known reinforcing material, a softening agent and the like may be blended in the rubber-like elastic body, and a blended material containing these rubber-like elastic bodies can also be used.

The tubular portion of the present invention is preferably made of a rigid material, and may be made of a known hard thermoplastic resin, hard thermosetting resin, metal or the like. For example, the metal includes iron, aluminum, copper, or an alloy containing them, and the hard thermoplastic resin is a polyester resin, a polypropylene resin, a polystyrene resin, a polyvinyl chloride resin,
ABS resin, AS resin, polycarbonate resin, methacrylic resin, polyacetal resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polyamide resin, fluororesin, PEEK resin, etc., and hard thermosetting resins are phenolic resins, melamine resins, Acrylic resin, epoxy resin, unsaturated polyester resin and the like can be mentioned.

When a thermoplastic hard resin is used for the cylindrical portion and a thermoplastic elastomer is used for the flexible portion, two-color molding by heat fusion becomes possible.

The lid of the present invention may have a single structure of the above-mentioned rigid material or rubber-like elastic body, or may have a composite structure of a combination of both. As a composite structure, for example,
The outer frame is made of a rigid thermoplastic resin, and has a disk-shaped structure in which a thermoplastic elastomer is spread inside.

Hereinafter, the vibration damping effect and the vibration durability of the viscous fluid-filled dampers of Examples and Comparative Examples were evaluated by the following test methods, and the results are shown in Table 1. As shown in FIG. 3, the test arrangement is such that four rigid shafts 4 projecting from the lower surface of the optical disk device 9 are inserted into four viscous fluid-filled dampers 10 and supported. The optical disk device 9 is suspended from the housing 12 by a tension coil spring 11. The viscous fluid-filled damper 10 and the housing 12 are fixed on a vibration table.

The evaluation method of the vibration-proof effect is as follows.
Is vibrated in a range of 0 Hz, done by measuring the vibration transmissibility of the optical disk apparatus, the resonance magnification and the resonance frequency of the vibrations transmitted to the optical disc apparatus at that time, the vibration input acceleration a ₁ from the excitation table the vibration output acceleration _{a 2} from against the optical disk apparatus is measured, 20 log (a
₁ / a ₂ ).

[0017]

Embodiment 1 FIG. 2 shows the configuration of a viscous fluid-filled damper of this embodiment. A container body 1 composed of a flexible portion 6 and a stirring portion 3 made of a rubber-like elastic body which is a styrene-based thermoplastic elastomer having a hardness of 25 (JIS K6253 type A), a cylindrical portion 7 made of polypropylene, and polypropylene Fluid 2 made of silicone oil having a rotational viscosity of 0.01 m ² / s and a foamed silicone foam (Toray Dow Corning Co., Ltd.)
A viscous fluid-filled damper was obtained by filling with a resistor 8 made of Silicone SEF10 and Asker C hardness: 1).

The shaft protruding from the optical disk device is inserted into the stirring portion of the container body, and when the external vibration occurs, the flexible portion is deformed and the stirring portion performs the stirring operation of the viscous fluid, thereby receiving the viscous flow resistance. Further, the orifice attenuation when the stirred viscous fluid moves and passes through the hole of the resistor can provide an anti-vibration effect to the optical disc device.
In addition, since the resistor is formed without a gap in the inner space of the container body from the periphery of the stirring section, similarly high attenuation is generated against external vibrations from all directions, and an anti-vibration effect is provided to the optical disk device. In addition to this, direct contact with the cylindrical portion and the lid can be avoided even with large swinging of the stirring section, and wear and breakage of the stirring section can be prevented.

[0019]

Example 2 The same structure as in Example 1 was used, except that the resistor was a foamed silicone foam and the viscous fluid was a rotational viscosity of 0.3 m ² / s.
Silicone grease was used.

[0020]

Comparative Example 1 As Comparative Example 1, a viscous fluid having a configuration similar to that of Example 1 but no resistor was used and the rotational viscosity was 0.01 m ^2.
/ S of silicone grease was used.

[0021]

Comparative Example 2 As Comparative Example 2, a viscous fluid having a configuration similar to that of Example 1 but no resistor was used, and a rotational viscosity of 0.3 m ² /
s silicone grease was used.

[0022]

[Table 1]

When viscous fluids having the same viscosity are used in Examples 1 and 2 and Comparative Examples 1 and 2, it is difficult to make a comparison because the resonance frequencies are different. Was kept lower. Further, when comparing Example 1 and Comparative Example 2 having substantially the same resonance frequency, Example 1 had lower values in both the resonance magnification and the transmissivity at 100 Hz. This is the same tendency with respect to external vibrations in the vertical direction (damper axis direction) and the horizontal direction (damper axis vertical direction). further,
Conventionally, when a severe vibration that caused breakage was applied, the viscous fluid flowed out due to breakage of the stirring part in Comparative Examples 1 and 2, but the viscous fluid-filled dampers of Examples 1 and 2 did not break. Was.

[0024]

As described above, according to the present invention, by providing a resistor made of a foam filled around or in the internal space so as to cover the agitating portion, the viscous resistance can be maintained even when the optical disk apparatus is largely moved. The stirrer of the fluid-filled damper was prevented from contacting the cylindrical portion and the lid, and leakage of the viscous fluid due to breakage of the stirrer was eliminated.

Furthermore, in addition to the damping resistance due to the viscous flow resistance, damping resistance is generated when the viscous fluid passes through the hole of the resistor made of the open-cell foam. By increasing the damping resistance and reducing the damping resistance in the high frequency band, the anti-vibration effect is improved,
When used in an actual in-vehicle CD mechanism, a viscous fluid sealed that can suppress mechanical contact in the low frequency band and prevent sound skipping due to reading errors of the optical pickup lens in the high frequency band An expression damper can be provided.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an embodiment of a viscous fluid-filled damper of the present invention.

FIG. 2 is a longitudinal sectional view of an embodiment of a viscous fluid-filled damper of the present invention.

FIG. 3 is a layout diagram of a viscous fluid-filled damper.

FIG. 4 is a longitudinal sectional view of an embodiment of a conventional viscous fluid-filled damper.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Container main body 2 Viscous fluid 3 Stirrer 4 Shaft 5 Lid 6 Flexible part 7 Cylindrical part 8 Resistor 9 Optical disk drive 10 Viscous fluid-filled damper 11 Coil spring 12 Housing

Claims (5)

[Claims] 1. A viscous fluid in which a viscous fluid is sealed in an inner space formed by a container body including a stirring portion, a cylindrical portion, a flexible portion connecting the stirring portion and the cylindrical portion, and a lid. A viscous fluid-filled damper, wherein an elastic resistor is disposed in an internal space in the fluid-filled damper. 2. The viscous fluid-filled damper according to claim 1, wherein the resistor is provided so as to cover the stirring section. 3. The viscous fluid-filled damper according to claim 1, wherein the resistor is filled in the internal space. 4. The viscous fluid-filled damper according to claim 1, wherein the resistor is made of a foam. 5. The viscous fluid-filled damper according to claim 4, wherein the resistor is made of an open-cell foam.