JPH022111Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a vibration isolating device with an excellent vibration damping effect whose vibration absorption characteristics can be changed depending on the degree of foaming.

Conventional vibration isolators use rigid solid materials for their internal materials, so they have sharp resonance characteristics, making it difficult to change the characteristics, and have the disadvantage that they do not provide sufficient vibration isolation over a wide frequency range. It was hot.

The purpose of this invention is to eliminate such drawbacks.

Therefore, in order to absorb vibrations over a wide frequency range, this idea uses a three-layered structure consisting of a lower base, elastic body, and upper base, and uses an upright cylindrical support to absorb vibrations in relatively low frequency components. and an elastic body having an annular arc section curved inward from the upper edge of the cylindrical support section, absorbing vibrations of relatively high frequency components using materials such as calcium carbonate, atactic polypropylene, and polyethylene. The upper table is made of a foam-containing molded product and has an annular recess with a cross-sectional shape into which the annular arc portion of the elastic body is inserted, and the lower table is made of a foam-containing molded product of the same quality as the upper table.

Hereinafter, embodiments will be described based on FIGS. 1 to 3 of the drawings.

The rubber elastic body 3 has an upright cylindrical support part 5 and an annular arc part 4 curved inward from the upper edge of the cylindrical support part 5. In the embodiment, in order to further reinforce the annular arc part 4 and the cylindrical support part 5, an annular outer base plate part 6 sitting on the outside and inside and an inner base plate part 6 provided with a center hole are integrally formed. It has been done. The upper table 1 and the lower table 2 are made by foaming a mixture of calcium carbonate as the main material mixed with a small amount of attic polypropylene to give it viscosity, and a small amount of polyethylene which hardens at room temperature and makes it easy to melt. Melting temperature of polypropylene (90℃~130℃)
It is a foam molded product that is heated to a higher molding temperature of polyethylene and formed into a desired shape using a mold, and the upper table 1 has an annular recessed part with a cross-sectional shape into which the annular arc part 4 of the elastic body 3 is inserted. It has been formed.
The elastic body 3 is sandwiched between the upper stand 1 and the lower stand 2, and the upper stand 1 is loosely fastened with a set screw 9 passing through the center hole 8 of the lower stand 2 and the elastic body 3.

Therefore, when the lower table 2 is placed on the floor 12 and the vibrating body 11 is placed in the recess 10 on the upper surface of the upper table 1, the low frequency component of approximately 200 Hz or less of the vibration from the vibrating body 11 is High frequency components of about 200 Hz or higher are absorbed by the low elasticity of the annular arc portion 4 of the upper table 1 and the lower table 2, and are absorbed by the viscosity provided by the atactic polypropylene of the upper table 1 and the lower table 2 and the air bubbles contained therein, so that a wide frequency range is achieved. It effectively absorbs vibrations over a wide range, and together with the elastic body 3 sandwiched between the upper table 1 and the lower table 2, it acts as a vibration absorber having different vibration absorption characteristics. Therefore, the vibrating body 1
As for the vibration 1, the vibration of high frequency components of about 200 Hz or more is relaxed while passing through the upper table 1, and the vibration energy of the frequency component of about 200 Hz or less is lost by the elastic body 3, and then the vibration energy of the frequency component of about 200 Hz or less is lost. 2 about 200Hz
By weakening the vibration energy of the above-mentioned high frequency components, almost no vibration is transmitted to the floor 12.

In the vibration isolator A of the embodiment, the upper table 1 and the lower table 2 are made of 56% by weight of calcium carbonate as the main material, attic polypropylene to give viscosity, and polyethylene to harden at room temperature and make melting easier. 12% by weight and a blowing agent of 20% by weight are mixed, heated and melted to a polyethylene molding temperature higher than the melting temperature of atactic polypropylene (90℃ to 130℃), and molded into the desired shape using each mold. It was obtained by forming an upper stand 1 and a lower stand 2 into a foam molded product, and was manufactured using the upper stand 1 and lower stand 2.

Next, the vibration absorption frequency characteristic of this vibration isolator A is as shown in FIG.
1' is directly placed on the surface plate 12' is detected by the vibration pickup 13, and the signal detected by the vibration pickup 13 is frequency-analyzed with a bandwidth of 10 Hz. As shown in FIG.
The vibration pickup 13 detects the acceleration of the vibration transmitted to the surface plate 12' when an equal load is applied to each vibration isolator (4 x A), and the signal detected by the vibration pickup 13 is converted into a signal with a bandwidth of 1.
Frequency analysis was performed at 0 Hz, and the level value of this frequency analysis was compared with the reference level 14 to obtain a vibration absorption frequency characteristic 15. The vibration absorption frequency characteristics of the vibration isolator A indicate that vibrations are well damped over a wide frequency range of approximately 30Hz to 1000Hz.

Vibration absorption frequency characteristic 15 damps vibration energy in the frequency range from approximately 180Hz to 30Hz (3)
This shows that the upper table 1 and the lower table 2 attenuate the vibration energy in the frequency band of approximately 180 Hz or higher.

As described above, the vibration isolator of this invention has an elastic body having an upright cylindrical support part and an annular arc part curved inward from the upper edge of the cylindrical support part, which is made of calcium carbonate, an attic material, etc. The lower stand is sandwiched between an upper stand made of a foam-containing molded product of polypropylene or polyethylene and provided with an annular recessed part with a cross-sectional shape into which the annular arc part is inserted, and a lower stand made of a foam-containing molded product of the same quality as the upper stand. By loosely fastening the upper stand, it is possible to significantly attenuate vibrations in a wide frequency range.

You can also change the amount of air bubbles on the upper and lower tables,
The thickness of the annular arc extending from the upper edge of the annular support part of the elastic body and curved inward may be uniformly changed, or the inner and outer wall thicknesses may be different. By setting the vibration absorption characteristics independently according to the above, there is an effect that the vibration absorption characteristics of the vibration isolator can be changed as appropriate depending on the application.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway side view of an embodiment of this invention;
FIG. 2 is an explanatory diagram of a method for measuring vibration absorption characteristics, and FIG. 3 is a diagram of frequency characteristics. 1...Upper stand, 2...Lower stand, 3...Bullet body, 4...
...An annular arc.

Claims (1)

[Scope of utility model registration request] The elastic body 3 having an upright cylindrical support part 5 and an annular arc part 4 curved inward from the upper edge of the cylindrical support part 5 is made of a foam-containing molded material of calcium carbonate, atactic polypropylene, or polyethylene. The lower stand 2 and the upper stand 1 are sandwiched between an upper stand 1 having an annular recessed part with a cross-sectional shape into which the annular arc part 4 is inserted, and a lower stand 2 made of a foam-containing molded product of the same quality as the upper stand 1. A vibration isolating device characterized by being loosely fastened.