JP2000065120A - Variable decrement type viscous fluid filled damper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high damping effect in a broad frequency range from a low-frequency range to a high-frequency range and to restrain a resonant power at a resonant frequency in a mechanism of a supported body. SOLUTION: A buffer 3 is provided around an agitating part 4 of a damper in which a viscous fluid 2 is filled. Amplitude is thereby made small even if acceleration is high in a high frequency range. Accordingly, vibration transmissibility is maintained low by the agitating part 4 and the viscous fluid 2 and a high vibration isolating characteristic effect is provided. Further, amplitude is made large in the high frequency range and the agitating part 4 largely moves to contact the buffer 3. Vibration transmissibility is, therefore, maintained low by the agitating part 4, the buffer 3 and the viscous fluid 2 and the high vibration isolating characteristic effect is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-vibration device for absorbing vibration from the outside used in information equipment such as audio equipment and optical disks, or precision electronic equipment, and more particularly to car electronics such as optical disks for vehicles. The present invention relates to a viscous fluid-filled damper used for vibration damping.

[0002]

2. Description of the Related Art Viscous fluid-filled dampers are used for audio equipment,
It is built into information equipment, especially in-vehicle CD players, and has excellent anti-vibration characteristics that absorb vibration transmitted from the outside to the pickup mechanism inside the player due to the viscous flow resistance of the viscous fluid filled in the damper (see Fig. 3).

The viscous fluid-filled damper may be used in combination with a metal tension or compression spring, depending on the weight and balance of the pickup mechanism, which is the supported body to be damped. In addition, there are various types of vibrations of automobiles, from low to high vibration frequencies or accelerations, and sometimes have an impact effect.

In response to such various vibrations, the viscosity of the viscous fluid of the viscous fluid-filled damper is adjusted so as to match the weight and balance of the supported member, and the hardness of the rubber-like elastic material enclosed is adjusted. By adjusting it, the optimal vibration isolation effect is provided.

Japanese Utility Model Application Laid-Open No. 63-164890 discloses a damper in which a rib is provided inside the damper as shown in FIG.

[0006] This is because, when the rib portion projecting from the damper side wall to the inside protrudes, an orifice is formed between the rib and the agitating portion into which the shaft is inserted at the time of large amplitude, and the fluid cannot move suddenly. The shock applied to the shaft due to resistance is reduced. Therefore, there is no danger of damage to the end of the stirring section.

[0007]

A damper filled with a high-viscosity viscous fluid generally has a large damping effect on low frequencies below 100 Hz, especially external vibrations in the resonance frequency range, but high frequencies above 100 Hz. With respect to vibration of a frequency, no damping force is exerted, and it is weak to lower the vibration transmissibility, that is, the vibration damping effect tends to decrease.

On the other hand, in a damper filled with a low-viscosity viscous fluid, the resonance magnification of the supported body increases near the resonance frequency of the supported body, especially at a low frequency (about 10 to 20 Hz). Near the frequency, sound skipping of the disk, malfunction, and the like are likely to occur. Also, the invention of Japanese Utility Model Application Laid-Open No. 63-164890 has a disadvantage that the agitating portion oscillates in the rib direction, and when the agitating portion and the rib come into contact, the fluid resistance is hardly generated, and the frequency range in which the damping effect occurs is narrowed. There is.

[0009]

SUMMARY OF THE INVENTION Accordingly, the present invention is directed to a variable damping type viscous sealing type damper which solves the above-mentioned problems, wherein a damping band is provided from a lid of a damper for sealing a viscous fluid toward a periphery of a stirring section. In a high frequency range, the amplitude is small even if the acceleration is large, so the vibration transmission rate can be reduced by the agitating part and the viscous fluid, and a high vibration isolation characteristic effect is obtained.
In the low frequency range, the movement of the stirrer increases because the amplitude is large, so that the stirrer and the buffer band come into contact with each other. Become. Therefore, it is possible to provide a viscous fluid-filled damper which has a large damping effect in a wide frequency range from a low frequency range to a high frequency range and suppresses the resonance magnification of the mechanism to be supported at the resonance frequency.

Further, according to the present invention, the agitating section and the buffer zone are rubber-like elastic materials, and the material is natural rubber, isoprene rubber, styrene butadiene rubber, ethylene propylene rubber, nitrile rubber, urethane rubber, butyl rubber, chloroprene rubber, silicone. Rubber, fluoro rubber, or thermoplastic styrene-based elastomer, olefin-based elastomer, PVC-based elastomer, urethane-based elastomer, polyester-based elastomer, etc. The hardness of the body is JIS-A type, preferably 10 to 90, and the loss coefficient is preferably 0.03 or more.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction of a variable damping type viscous fluid-filled damper of the present invention will be described below with reference to the drawings. FIG. 1 shows a cross-sectional view according to an example of the viscous sealing type damper of the present invention. The container 1 is composed of a rubber elastic body alone (a), a rubber elastic body 1b and a hard resin 1a, or a composite structure of a rubber elastic body and a metal (b). And sealed. The lid 6 has a rubber-like elastic structure similar to that of the container 1. In the container 1, a stirring part 4 is depressed into a cylindrical shape from above, and a rigid shaft 5 protruding from a supported member is inserted into a cylindrical resistance part of the stirring part 4.

In the container 1, a buffer band 3 made of a rubber-like elastic material is projected from the lid 6 at a slight distance from the side wall. When an external vibration is generated, the amplitude of the stirring unit 4 and the shaft 5, that is, the stirring operation, causes the viscous resistance of the viscous fluid 2 and the stress relaxing action of the buffer band 3, so that the supported member has a vibration-proof effect. For example, in the vicinity of the resonance frequency of the supported member having a large amplitude of the stirring section 4 and the shaft 5, the stirring section 4 comes into contact with the buffer band 3 made of a rubber-like elastic body, alleviating the stress and the viscosity between the buffer band and the container. The viscous flow resistance of the fluid has an effect of suppressing the resonance magnification of the supported member. When the amplitude of the stirring section 4 and the shaft 5 is small, the stirring section 4
Exerts a high vibration damping characteristic effect due to the viscous flow resistance of the viscous fluid 2 without contacting the buffer zone 3.

The viscous fluid of the present invention is obtained by adding an appropriate amount of polymethylsilsesquioxane powder and sufficiently kneading the fluid to increase the rotational viscosity, and preferably has a rotational viscosity adjusted to 100 to 1000 kcs.

[0014]

[Embodiment 1] The container 1 is made of hardness (JIS-K-6301-
A type) A rubbery elastic body using butyl rubber of 30 was filled with a viscous fluid 2. This viscous fluid is added to dimethyl silicone oil (10 kcs, manufactured by Toray Dow Corning Silicone Co., Ltd.) to increase the rotational viscosity. -900)
Is added and kneaded well, with a rotational viscosity of 1000 kc.
s. An annular buffer band 3 was projected from the lid 6 using the same rubber-like elastic body as the container with a gap of 0.8 mm around the outer periphery of the stirring unit 4.

[0015]

Comparative Example 1 FIG. 4 shows a conventional damper. Container 11
Is made of a rubber-like elastic body using butyl rubber having a hardness (JIS-K-6301-A type) of 30, and filled with a viscous fluid 12. This viscous fluid is converted into dimethyl silicone oil (manufactured by Toray Dow Corning Silicone Co., Ltd., 10 kcs product) in order to increase the rotational viscosity. Trefil R-900) was added and kneaded well in an appropriate amount, and the rotational viscosity was adjusted to 1000 kcs. The rib 13 extending from the side of the container 11 to the inside is horizontally stirred by the stirring unit 14.
Was formed so as to have a gap of 0.8 mm on the outer periphery thereof.

[0016]

Comparative Example 2 FIG. 3 shows a conventional damper. Container 21
Is made of butyl rubber having a hardness of 30 (JIS-K-6301-A type), and the viscous fluid 22 is made of dimethyl silicone oil and polymethylsilsesquioxane powder having an average particle diameter of 20 μm (manufactured by Toray Dow Corning Silicone Co., Ltd.). , Trefil R-900) was sufficiently kneaded, and only a silicone grease viscous fluid having a rotational viscosity of 1000 kcs was filled and filled.

A test method for evaluating the anti-vibration effect of the variable damping type viscous fluid-filled damper manufactured as described above will be described with reference to FIG. 2 which is a cross sectional view. The weight of the supported member A is
380 g, from which four rigid shafts protrude, and this shaft C is inserted into four damping variable type viscous fluid filled dampers B of the present invention to support the supported member A. , And a tension coil spring D (4
The present invention also supports the supported body. The frame E is a metal frame to which a damping variable viscous fluid filled damper B and a tension coil spring D can be attached.
It is fixed to the excitation table F.

Table 1 shows the results of vibration transmission measurement of the present invention and the conventional damper.

[0019] The direction of the vibration with respect to FIG. 2, is vibrated in the frequency range of 8~200Hz constant acceleration in the vertical direction, the resonance magnification to be supported with respect vibration input acceleration a ₁ from the excitation table to the resonant frequency the vibration output acceleration _{a 2} from the body _{a 2}
/ A ₁ , and the vibration transmissibility at 100 Hz also shows the same relationship.

Referring to Comparative Example 1 and Example 1, the stress relaxation effect when the buffer band 3 of the embodiment comes into contact with the agitating section 4 near the resonance point having a large amplitude, and the viscous fluid between the buffer band and the container is removed. A decrease in resonance magnification was confirmed by viscous flow resistance. In the high frequency range (around 100 Hz) which is the vibration proof region, a vibration proof damping effect superior to Comparative Example 1 is recognized. In Comparative Example 2 and Example 1, a decrease in resonance magnification was confirmed near a resonance point having a large amplitude. In a high frequency range (around 100 Hz), which is a vibration proof region, a vibration proof damping effect superior to Comparative Example 2 is observed.

[0021]

As described above, according to the present invention, by providing a buffer band made of a rubber-like elastic body inside a viscous fluid, the rubber-like elastic body can be vibrated around a frequency where the amplitude of the supported object to be damped is large. Utilizing stress relaxation to improve the vibration isolation effect. When used in an actual in-vehicle CD mechanism, it is expected to have the effect of preventing the occurrence of sound skips and malfunctions near the resonance point, and the damping effect due to the flow resistance of the internal viscous fluid at high frequencies with small amplitudes. The present invention can provide a variable damping type viscous fluid-filled damper capable of exhibiting the following characteristics.

[Brief description of the drawings]

FIG. 1 is a sectional view of a damper of the present invention.

FIG. 2 is a cross-sectional view of the test method.

FIG. 3 is a sectional view of a conventional damper.

FIG. 4 is a sectional view of a conventional damper.

[Table 1] Vibration transmission measurement results

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Container 1a Hard resin 1b Rubbery elastic body 2 Viscous fluid 3 Buffer band 4 Stirrer 5 Shaft 6 Lid A Supported member B Damper variable damping type viscous fluid sealing damper C Shaft D Coil spring E Frame F Vibration table

Claims (2)

[Claims] A viscous fluid is sealed in a container having a stirring section made of a rubber-like elastic body and a lid, and the stirring section of the rubber-like elastic body moves in the viscous fluid in response to external vibration. A damping variable damping type viscous fluid-filled damper having a damping force that generates a viscous resistance and has a slight gap with the agitating portion and a buffer band made of a rubber-like elastic body protruding from a lid. . 2. The rubber-like elastic body is made of natural rubber, isoprene rubber, styrene butadiene rubber, ethylene propylene rubber, nitrile rubber, urethane rubber, acrylic rubber, chloroprene rubber, butyl rubber, silicone rubber, fluorine rubber or thermoplastic styrene. The damping type viscous fluid-filled damper according to claim 1, wherein the damper is made of at least one of an elastomer, an olefin-based elastomer, a PVC-based elastomer, a urethane-based elastomer, and a polyester-based elastomer.