JP2012062982A - Devibration device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simple and cheap devibration material which is compact and low in height and which isolates floor vibration or which does not transmit mechanical vibration etc. on a floor.SOLUTION: A devibration device is composed of a devibration unit 100 which penetratingly disposes a coil spring 2 in holes of a flexible/elastic sheet 1 with a plurality of punched identical diameter holes respectively and which disposes on the axial both end side of each coil spring a set of unit rubber plates 3,4 which surround a region corresponding to the outer diameter of the coil spring while leaving a connection portion and form a pair of slits 3C, 4C opposed to each other which form an island portion corresponding to the region in the inside thereof and which is configured to interpose the rubber sheet with an outside portion of the slit and fix in one piece with a screw nut 5 or a rivet penetrating them while compressing the coil springs which are between them at each of the island portion of the set of unit rubber plate.

Description

  The present invention relates to a vibration isolation device for isolating a semiconductor manufacturing inspection apparatus, an electron microscope, an air compressor, a vacuum pump, a press machine, a precision instrument such as a piano, an industrial machine, an acoustic instrument, and the like.

  Anti-vibration rubber, coil springs, air springs, etc. are used as vibration isolation materials, but these vibration isolation materials are designed with the idea of supporting the machine as a point. At the time of vibration isolation design, design factors such as machine mass, center of gravity position, excitation force, floor rigidity, mechanical vibration tolerance, floor vibration tolerance, etc. could not be grasped. Therefore, the vibration isolator may be replaced and the installation position may be moved. If it is point support, it takes time to replace and move the vibration isolator. Further, the support mass per support point is increased, and the planar dimensions and height are increased.

  Anti-vibration rubber is the most commonly used vibration isolator. Small, lightweight, inexpensive and vibration damping, easy to use, but hard spring action and poor vibration isolation performance. In the mass region where the support mass is small, the vibration-proof rubber is small and a low natural frequency cannot be obtained.

Hereinafter, the vibration isolation action of the vibration isolation material will be described for the system shown in FIG.
In the figure, Ma represents a supporting machine, D represents a vibration isolator, and Floor represents a floor. The vibration frequency of the machine Ma to be supported or the vibration frequency of the floor floor is f (Hz), the dynamic spring constant of the vibration isolation material is k _d (N / M), the loss factor of the vibration isolation material is η, and the support mass is m (kg) ), Where the initial value of the impact response amplitude is z ₀ (M), the natural frequency f _n (Hz) of the system, the vibration transmissibility Tr, and the impact response amplitude z (M) are expressed by equations (1) and (2), respectively. (3). However, M in parentheses is a meter.

FIG. 23 shows the frequency characteristics of vibration transmissibility of typical coil springs and vibration-proof rubbers, and FIG. 24 shows the impact response. In these figures, a is the characteristic of the coil spring and b is the characteristic of the vibration-proof rubber.
As shown in FIG. 23, when the natural frequency is low, the vibration transmissibility Tr in a frequency region (for example, 20 to 40 Hz) to be a vibration isolation becomes small and the vibration isolation performance is improved.

A vibration isolator having various structures combining a coil spring and a viscoelastic body has been proposed (for example, Patent Document 1), all of which have a point support structure. In the case of point support, if an attempt is made to increase the support mass, the size becomes large, and the height of the vibration isolation device increases.

  The air spring has vibration damping ability due to the soft spring action of compressed air and the air throttling effect, and is excellent in vibration isolation performance, but it is large and expensive in structure and lacks versatility.

  The coil spring has a soft spring action and a low natural frequency regardless of the supporting mass and is excellent in vibration isolation performance, but has a low vibration damping capability. If the attenuation is small, the peak value (resonance magnification) in the graph of FIG. 23 increases. Further, the convergence of the impact response amplitude shown in Expression (3) or FIG. 24 is delayed.

  When installing a machine etc. in a factory, naturally the height including a vibration isolator must be able to be accommodated in the factory. In addition, considering the attached pipes, ducts, etc., it goes without saying that the lower the height of the vibration isolation material, the better.

JP 2004-324654 A

  An object of the present invention is to provide a simple and inexpensive line-supported or surface-supported vibration isolator that is small in size, low in height, insulates floor vibration, or does not transmit mechanical vibration or the like to the floor.

In order to achieve the above object, according to a first embodiment of the present invention, a coil spring is disposed through each of the holes of a flexible / elastic sheet obtained by punching a plurality of holes of the same diameter, and both axial sides of each coil spring are disposed. In addition, a pair of unit rubber plates that surround a region corresponding to the outer diameter of the coil spring leaving a connecting portion and in which a pair of opposed slits forming an island portion corresponding to the region are formed are disposed. The rubber sheet is sandwiched between the outer portions of the slit while compressing the coil spring between the island portions of the pair of unit rubber plates, and is integrally fixed with a screw nut or a rivet penetrating the rubber sheet. It is characterized by comprising a vibration isolation unit.
In the following description, a unit in which one coil spring of the vibration isolation device of the present invention is fixed to a flexible elastic sheet with a set of unit rubber plates is referred to as a “vibration isolation unit”.

  In the second embodiment of the present invention, the spring constant of each coil spring in the first embodiment is 3 to 30 N / mm, and the spring constant of each island portion of the unit rubber plate is 3 to 35 N / mm. The combined spring constant of the coil spring and the pair of islands sandwiching the coil spring is 6 to 65 N / mm, and the support mass of the coil spring of one vibration isolation unit is 40 kg or less.

  The third embodiment of the present invention is characterized in that the unit rubber plate of the vibration isolation unit is disk-shaped, and two arc-shaped slits are formed on the concentric circles so as to face each other.

  In a fourth embodiment of the present invention, the unit rubber plate has a rectangular shape, and two U-shaped slits are formed to face each other across two opposite sides of the rectangle. It is characterized by that.

  In a fifth embodiment of the present invention, coil springs are respectively disposed through the rectangular holes of a flexible elastic sheet in which a plurality of rectangular holes of the same size are punched, and the upper and lower ends of each coil spring are centered on the outer diameter of the coil spring. The unit rubber plate is brought into contact with the flexible elastic sheet while being engaged with the concave portion of a strip-shaped unit rubber plate having a circular concave portion corresponding to and compressing the coil spring via the unit rubber plate. Thus, the flexible elastic sheet is integrally fixed with a screw nut or a rivet penetrating the square hole of the flexible elastic sheet.

  In the sixth embodiment of the present invention, both ends of the pair of unit rubber plates sandwiching the coil spring in the fifth embodiment are not fixed integrally with a screw nut or a rivet, but are integrated when a unit rubber plate is molded by a rubber mold. The flexible elastic sheet is molded by an adhesive and is characterized by being molded.

  According to a seventh embodiment of the present invention, in any one of the first to sixth embodiments, the ratio of the coil spring height and the coil spring center diameter of each vibration isolation unit (coil spring height / coil spring center diameter) is 2. It is characterized by the following.

  The eighth embodiment of the present invention is characterized in that, in any of the first to sixth embodiments, the natural frequency of the coil spring of each vibration isolation unit is 4.5 to 8.5 Hz.

  The ninth embodiment of the present invention is characterized in that in any one of the first to eighth embodiments, the height of each vibration isolation unit is 50 mm or less when no mass is loaded.

According to a tenth embodiment of the present invention, there is provided a cutting material for individually separating the vibration isolation unit on the flexible elastic sheet having a circular or square hole punched out in any one of the first to ninth embodiments. It is characterized by a groove.
The cutting groove is preferably formed in a lattice shape, and the hole through which the coil spring passes is preferably formed at the center of a rectangular region surrounded by the groove.
Examples of the flexible elastic sheet include a rubber sheet and a plastic sheet.

  Since the vibration isolator of the present invention has a structure in which vibration isolation units mainly composed of coil springs are assembled, even if the supporting mass is small, a natural frequency smaller than that of the vibration isolating rubber can be obtained. Moreover, vibration damping capability is added by bending and shearing deformation of the unit rubber plate. As a result of suppressing the allowable mass per anti-vibration unit and collecting multiple anti-vibration units, a vibration isolator having a low height is obtained, and the anti-vibration sheets assembled according to the support mass are cut. Any number of vibration isolation units can be used.

It is a figure which shows schematic structure of the vibration isolator which is 1st Embodiment of this invention. It is a cross-sectional schematic diagram seen from the arrow direction of the XX line in FIG. It is a figure which shows schematic structure of the vibration isolator of the vibration isolator which is 1st Embodiment of this invention. It is the side view which looked at the vibration isolator of FIG. 3 which is 1st Embodiment of this invention from the Y-axis direction. It is the side view which looked at the vibration isolator of FIG. 3 which is 1st Embodiment of this invention from the X-axis direction. It is a top view of the unit rubber board of the vibration isolator which comprises the vibration isolator which is 1st Embodiment of this invention. It is sectional drawing seen from the BB line direction of FIG. 6 which is a top view of the unit rubber board of the vibration isolation unit which comprises the vibration isolator which is 1st Embodiment of this invention. It is a side view of the coil spring of the vibration isolation unit which comprises the vibration isolator which is 1st Embodiment of this invention. It is a top view of the rubber sheet which comprises the vibration isolator which is 1st Embodiment of this invention. It is a figure which shows the assembly method of the vibration isolator which comprises the vibration isolator which is 1st Embodiment of this invention. It is a top view of a unit rubber board which constitutes a vibration isolator which is a modification of a 1st embodiment of the present invention. FIG. 12 is a cross-sectional view taken along line BB in FIG. 11, which is a plan view of a unit rubber plate that constitutes a vibration isolation unit that is a modification of the first embodiment of the present invention. It is a figure which shows schematic structure of the vibration isolator of the vibration isolator which is 2nd Embodiment of this invention. It is a figure which shows the schematic structure seen from the Y-axis direction of the vibration isolator of the vibration isolator which is 2nd Embodiment of this invention. It is a figure which shows schematic structure of the vibration isolator of the vibration isolator which is 3rd Embodiment of this invention. FIG. 16 is a cross-sectional view taken along line BB in FIG. 15, illustrating a schematic structure of the vibration isolation unit of the vibration isolation device according to the third embodiment of the present invention. It is a figure explaining the effect | action of the vibration isolation unit of this invention. It is a figure which shows the relationship between the support mass and natural frequency of the Example and comparative example of this invention. It is a figure which shows the relationship between the support mass and height of the Example and comparative example of this invention. It is a figure which shows the frequency characteristic of the vibration transmissibility of the Example and comparative example of this invention. It is a figure which shows the impact response characteristic of the Example and comparative example of this invention. It is a figure which shows the system targeted for vibration isolation. It is a figure which shows the frequency characteristic of the vibration transmissibility of a typical coil spring and vibration-proof rubber. It is a figure which shows the characteristic of the impact response of a typical coil spring and anti-vibration rubber.

A case will be described in which the vibration isolation device of the present invention is applied to a system in which the installation area of a device to be subjected to vibration isolation is 1 m × 1 m and the mass of the device is 1,000 kg. This device belongs to the heaviest category as a vibration isolation object to which the present invention is applied.
In this embodiment, a vibration isolation device in which a plurality of vibration isolation units are arranged in series is installed along the outer peripheral portion of the vibration isolation target device. The width of the vibration isolation device is 5 cm, and the size of the vibration isolation unit is 5 cm × 5 cm. The total length of the outer circumference of the equipment to be installed is 100 cm × 2 + (100 cm−5 cm−5 cm) × 2 = 380 cm, but the vibration isolation units corresponding to the eccentric centers of gravity are arranged one by one in 10 cm. If it arrange | positions only to 1/2, the circumference of 190 cm will become an effective installation length. Therefore, 190 cm / 5 cm = 38 vibration isolation units are arranged. Since the mechanical mass is 1,000 kg, 1,000 kg ÷ 38 pieces = 26.3 kg, that is, a mass supporting capacity of 26.3 kg per vibration isolation unit is sufficient. With a margin, one vibration isolation unit has a maximum support capacity of 40 kg.

  In the floor area of 1 m × 1 m, the mass of equipment belonging to the lightest category is 40 kg. In this case, if the balance of the center of gravity of the device is taken into consideration and the eight-point support is used, the support mass is 40 kg ÷ 8 = 5 kg / piece. In addition, the minimum of the support mass per vibration isolation unit is about 2 kg.

  In the embodiment of the present invention, it is possible to reduce the size by suppressing the supporting mass of the vibration isolation unit to 2 to 40 kg / piece and the natural frequency to about 6 to 8 Hz. The installation plane area is preferably 5 cm × 5 cm, and the height when mass is supported is preferably 40 mm or less. If the natural frequency is 4.5 to 8.5 Hz, vibrations of the machine or floor having a frequency of 15 Hz or more can be isolated. In general, since vibrations with a frequency of 15 Hz or more are a problem, most vibration problems can be solved by this embodiment. Incidentally, in the case of the anti-vibration rubber, when the support mass is 40 kg or less, the anti-vibration rubber becomes small, and the natural frequency cannot be made 8 Hz or less.

  Further, when the support mass of the vibration isolation unit is 2 to 40 kg and the spring constant of the vibration isolation unit is obtained in a predetermined height range, it is 6 to 65 N / mm. In the present invention, since the coil spring and the unit rubber plate share the two, the spring constant of the coil spring is 3 to 30 N / mm, and the spring constant of the unit rubber plate is 3 to 35 N / mm.

  Since the vibration isolator of the present invention can be constituted by a plurality of vibration isolation units by cutting the flexible elastic sheet, it is easy to correct the center of gravity, correct the mass estimation error, and increase the mass support. The thickness can be reduced to 40 mm or less, and vibration isolation measures are facilitated. In order to further enhance the vibration isolation effect, if the vibration isolation devices are stacked in two stages, the natural frequency is theoretically reduced to 1/2.

Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings.
1 to 24, the same portions are denoted by common reference numerals, and redundant description is omitted.
FIG. 1 is a plan view of a vibration isolator 10 in which a total of 16 vibration isolation units 100 of the present invention are 4 × 4 horizontal, and FIG. 2 is a cross-sectional view taken along line XX of FIG. 3 is a plan view of each vibration isolation unit, FIG. 4 is a side view from the Y-axis direction of FIG. 3, and FIG. 5 is a side view seen from the X-axis direction.

The first embodiment of the present invention shown in these drawings is a rubber sheet 1 punched through a plurality of holes (coil spring escape holes) 1a of the same diameter, and expands and contracts so as to penetrate through the holes 1a of the rubber sheet. A coil spring 2 having a center diameter / height of 2 or less arranged with the direction orthogonal to the surface of the rubber sheet 1, and unit rubber plates 3, 4 arranged on both sides of the rubber sheet 1 with the coil springs 2 sandwiched therebetween. And the unit rubber plate 3, the rubber sheet 1, and the unit rubber plate 4, and a screw nut 5 for fixing them together.
At positions corresponding to the respective holes 1a of the rubber sheet 1 of the unit rubber plates 3 and 4, a region corresponding to the outer diameter of the coil spring 2 is surrounded by leaving the connecting portions 3a and 4a, and island portions A3 and A4 are formed inside. A pair of slits 3c, 4c is formed.
In the unit rubber plates 3, 4, the connecting portions 3 b, 4 b are brought into contact with the rubber sheet 1 from both sides in a state where the coil spring 2 is pressed and contracted, and are fixed with screw screws 5. The connecting portions 3b and 4b of the unit rubber plates 3 and 4 are stretched by the elastic force of the coil spring 2, and the island portions A3 and A4 are separated from the surface of the rubber sheet 1 as shown in FIGS. It has become.
Next, the assembly method of this embodiment will be described.
6 is a plan view of a unit rubber plate used in this embodiment, FIG. 7 is a cross-sectional view taken along line B-B, FIG. 8 is a side view of a coil spring, FIG. 9 is a plan view of a rubber sheet, and FIG. FIG.

In this embodiment, as shown in FIG. 9, grooves 1b are formed in a lattice pattern on the rubber sheet 1, and a plurality of relief holes 1a in which the coil springs 2 are arranged at the center of a rectangular area defined by the grooves 1b are formed. A pair of screw nut holes 1d are formed with each escape hole 1a interposed therebetween.
Also, as shown in FIGS. 6 and 7, the unit rubber plates 3 and 4 are formed with coil spring receiving recesses 3a and 4a on one side, respectively, and concentric circles are formed on the outer sides of the connecting portions 3b and 4b. Arc-shaped slits 3c and 4c are formed. Screw nut holes 3d and 4d corresponding to the screw nut holes 1c of the rubber sheet 1 are formed outside the central portions of the slits 3c and 4c.
As shown in FIG. 10, these unit rubber plates 3 and 4 and the rubber sheet 1 are overlapped in the order of the unit rubber plate 3, the rubber sheet 1, and the unit rubber plate 4 with the screw nut holes aligned, and screw screws are installed in the screw nut holes 3d and 4d. Insert them and fasten them together.
Next, the coil spring 2 compressed by extending the inner portions (island portions) of the slits 3c, 4c of the unit rubber plates 3, 4 while stretching them so that both ends engage with the recesses 3a, 4a. Insert.

  In the vibration isolator assembled in this way, the coil spring 2 is detachable because it is fitted in the recesses 3a and 4a of the two unit rubber plates that can be deformed by tension, and has a spring constant according to the supporting mass to be shared. A suitable coil spring can be selected, and the vibration isolation unit 100 can be attached and detached without being disassembled.

  The vibration isolation units are collectively connected by the rubber sheet 1. The rubber sheet 1 may be provided with a cutting groove 1b so that it can be easily cut into the required number of units.

  In the above-described vibration isolation unit, the unit rubber plate has a disc shape, but an example of a square plate is shown in FIG. 11 (modified example of the first embodiment). As shown in FIG. 11, the unit rubber plates (31, 41) are square (rectangular), and the slits 31c (41c) are U-shaped. FIG. 12 shows a sectional view taken along line BB in FIG.

  FIG. 13 is a plan view showing the vibration isolation unit 101 constituting the vibration isolation device according to the second embodiment, and FIG. 14 is a side view of the vibration isolation unit 101 in the Y-axis direction. In this embodiment, the escape hole 12a of the coil spring provided in the rubber sheet 12 has a rectangular shape, and the unit rubber plate has a strip shape with the coil spring accommodating recess 32a (42a) at the center. In this example, the spring constants are different for the horizontal X direction and the Y direction. The Y direction mainly consists of bending and shear deformation of the coil spring, but the X direction has a larger spring constant than the Y direction because the deformation of the unit rubber plate includes the compression component of the coil spring.

  There are two types of spring constants: a static spring constant and a dynamic spring constant. The spring constant when the elastic body is slowly applied is called the static spring constant, and the spring constant in the state where the vibration is applied is called the dynamic spring constant. The ratio obtained by dividing the dynamic spring constant by the static spring constant is called the dynamic magnification. When the unit rubber plate is added, if the vibration damping ability, that is, the loss factor η is the same, the smaller the dynamic magnification, the smaller the natural frequency is obtained, and the vibration isolation effect is greater.

  In the coil spring, the loss factor of the equation (1) is approximately η = 0.01 or less, and the static spring constant and the dynamic spring constant can be regarded as substantially equal, so the dynamic magnification is 1. In the present invention, the unit rubber plate is bent and sheared, not compressed, so that the length dimension can be increased compared to the cross-sectional area, and the transverse elastic modulus is about 1/3 of the longitudinal elastic modulus. Therefore, a small value is obtained for the static spring constant of the unit rubber plate. In addition, bending and shear deformation have a smaller dynamic displacement because inter-molecular displacement is smaller than compression deformation, so that a small dynamic spring constant can be obtained.

The constant k _{d in} equation (1) is the sum of the spring constant of the coil spring and the spring constant of the rubber plate. As described in the previous section, since the dynamic spring constant of the unit rubber plate added to the coil spring having a dynamic magnification of 1 is small, the increase in the natural frequency of equation (1) is small, and the vibration transmissibility of equation (2) is small. Become. Further, in the present invention, as shown in FIG. 17, when a compressive load P is applied in the vertical direction, the width D of the vibration isolation unit is widened, the rubber sheet 3 is tensilely deformed, and further, the spring constant and vibration damping capacity of the rubber sheet. Is added.

  FIG. 15 shows a structure in which unit rubber plates 33 and 43 of a vibration isolation unit constituting the vibration isolation device according to the second embodiment of FIG. It is. The unit rubber plate and the rubber sheet 13 are bonded to each other by the bonding surface 6 and do not include a screw nut or a rivet. Also in this case, the escape hole 13a of the coil spring is rectangular as in the case of the second embodiment.

The height of the vibration isolation unit is shown below for Example 4 having a maximum support mass of 40 kg.
H _O = δ _ST + Ha + δs + 2t (mm) ……………………… （4）
H _O : Vibration-free unit height at no load mm
δ _ST : Static deflection
The necessary δ _{ST is set} to 15 mm when the maximum support mass is 40 kg in consideration of the fact that the dynamic spring constant is harder than the static spring constant by suppressing the natural frequency to 4.5 to 8.5 Hz.
If the natural frequency is 3.5 Hz as in the conventional product, δ _ST is 40-60 mm is required.
Ha: Coil spring contact height (Ha = 17.6mm at 40 kg)
δs: A margin (5 mm) for preventing close contact when the coil spring is bent by 15 mm.
t: Thickness (3.5 mm) of the unit rubber plate in which the coil spring is inserted.
H _O = 15 mm + 17.6 mm + 5 mm + 7 mm = 44.6 mm
The height H at 40 kg is
H = 44.6mm-15mm = 29.6mm
In Examples 1, 2, and 3, the coil spring has a thin wire diameter and a low contact height, so the height at a maximum support mass of 5 kg, 10 kg, and 20 kg is 22 mm.

  A plurality of vibration isolation units, that is, coil springs with unit rubber plates, are assembled by rubber sheets. In general, in the installation of a machine, the vibration isolator installation part under the machine has a height limitation but has a margin in plan, and can support a wide surface. If the sheet is cut into a T shape, an L shape, a rectangle, etc. and arranged so that the coil springs are bent evenly, the level adjustment mechanism of the vibration isolator is not necessary. As a result of obtaining uniform deflection, the maximum deflection can be obtained by minimizing the number of coil springs used. As a result, the minimum natural frequency can be obtained and good vibration isolation performance can be obtained.

  The allowable support mass of the vibration isolation unit having the structure of FIG. 1 is 5 kg (Example 1), 10 kg (Example 2), 20 kg (Example 3), and 40 kg (Example 4). The natural frequency in the case of loading from 100% to 100% is shown by a thick solid line in FIG. Example 1 is a code number a, Example 2 is a code number b, Example 3 is a code number c, and Example 4 is a code number d. The material of the unit rubber plate is high damping synthetic rubber. In Example 5, the high damping rubber of Example 3 was replaced with natural rubber. (Code number: e). In Example 5, the damping capacity is small and the resonance magnification is 28 dB and η = 0.04. However, since the dynamic magnification is small, a low natural frequency of 6.5 Hz is obtained with a support mass of 10 kg and 4.8 Hz with 20 kg. Yes.

  In the case of Examples 1 to 4 of the high-damping rubber, an average result of approximately 6.0 Hz (100% of the allowable support mass) to 8 Hz (50% of the allowable support mass) was obtained. This corresponds to a natural frequency about half that of the anti-vibration rubber, that is, a dynamic spring constant of 1/4 of the anti-vibration rubber. FIG. 19 shows the height when the supporting mass of each vibration isolation unit is 80%. Also in FIG. 19, the code numbers corresponding to the respective embodiments are the same.

  The frequency characteristics of the vibration transmissibility when the natural frequencies of Examples 1 to 4 are regarded as 7 Hz on average and the loss factor η as 0.18 are shown as a code number c in FIG. Show.

Comparative example

  As a comparative example, a small anti-vibration rubber (Comparative Example 1) φ15 × 17.8, φ20 × 21.4, φ30 × 29.6, average natural frequency of 12 Hz, loss factor η of 0.1, and widespread use 20 shows the frequency characteristics of the vibration transmissibility when the natural frequency of the type coil spring (Comparative Example 2) is 4.5 Hz and the loss factor η is 0.01. The waveform of the impact response is shown in FIG.

  As shown in FIGS. 20 and 21, those having a natural frequency intermediate between the anti-vibration rubber and the popular coil spring were measured at the maximum support mass of 40 kg or less in Examples 1 to 4. The unit rubber plate of Example 1 is circular as shown in FIG. 1, but its cross-sectional dimensions are 7.5 mm in width, 3.7 mm in thickness, and 15 mm in arc length. The spring constant of the coil spring was 3.23 N / mm, the spring constant of the unit rubber plate was 3.89 to 5.10 N / mm depending on the supporting mass, and the total spring constant was 7.12 to 8.33 N / mm. The natural frequency was 6.5 to 8.5 Hz, the dynamic magnification was 2.5 times, and the resonance magnification was 12 dB on average (loss factor η = 0.25).

  In Example 2, the rubber plate has a width of 7.5 mm, a thickness of 4.0 mm, and an arc length of 15 mm. The spring constant of the coil spring was 6.90 N / mm, the spring constant of the rubber plate was 5.72 to 7.29 N / mm, and the total spring constant was 12.62 to 14.19 N / mm. As a result, a natural frequency of 8 to 6 Hz, a dynamic magnification of 1.8 to 2.0 times, and a resonance magnification of 13 dB (η = 0.22) on average were obtained.

  In practical example 3, the width of the unit rubber plate is 7.5 mm, the thickness is 5.0 mm, and the arc length is 15 mm. The spring constant of the coil spring was 14.20 N / mm, the spring constant of the unit rubber plate was 7.98 to 14.19 N / mm, and the total spring constant was 22.18 to 28.39 N / mm. Measurement results were obtained with a natural frequency of 6 to 7.5 Hz, a dynamic magnification of 1.5 to 2.0 times, and an average resonance magnification of 15 to 17 dB (η = 0.14 to 0.17).

  In Example 4, the width of the unit rubber plate is 7.5 mm, the thickness is 6.0 mm, and the arc length is 18 mm. The spring constant of the coil spring was 25.6 N / mm, the spring constant of the unit rubber plate was 24.46 to 27.46 N / mm, and the total spring constant was 50.48 to 53.06 N / mm. The natural frequency was 5.8 to 8 Hz, the dynamic magnification was 1.7 to 1.8 times, and the resonance magnification was 18 dB (η = 0.12) on average. One size of the vibration isolation unit is an outer diameter of Φ42 when the allowable support mass is 5 to 20 kg, a height of 36 mm when assembled, a height of 22 mm when supporting the allowable load, an outer diameter of Φ48 mm when the allowable support mass is 40 kg, and when assembled. The height is 44.6 mm, and the height at the allowable support mass is 29.6 mm. High-damping vibration isolator is favorably used for reciprocating compressors, vibration conveyors, press machines, liquid crystal inspection devices, etc.

  On the other hand, rotating machines such as blowers and pumps have no impact force and do not require the application of high damping leaf springs. It is possible to reduce vibration transmission rate by obtaining a low natural frequency with low damping and low dynamic magnification like natural rubber. As described above, the natural frequency when natural rubber is used for an allowable support mass of 20 kg is shown by a thick broken line in FIG. The natural frequency is reduced by about 20% with respect to the high damping rubber.

  The ratio (h / d) between the height h of the coil spring and the center diameter d (h / d) is set to 2 or less to ensure stability when the machine is supported. Even if two stages are stacked, the vibration isolator is not buckled and the machine can be supported stably. If two stages are stacked, the natural frequency becomes 4.2 to 5.6 Hz, and vibrations of the machine and floor frequencies of 7 to 10 Hz can be eliminated.

DESCRIPTION OF SYMBOLS 1, 12, 13 ... Rubber sheet 1a, 12a, 13a ... Coil spring relief hole 1b, 12b, 13b ... Rubber sheet cutting guide groove 2 ... Coil spring 3, 31, 32, 33, 4, 41, 42 ...... Unit rubber plates 3a, 31a, 32a, 33a, 4a, 41a, 42a ... Coil spring receiving recesses 3b, 31b, 32b, 33b ... Connecting parts 3c, 31c, 4c, 41c ... Slits 3d, 31d, 4d , 41d ... Screw nut hole 5 ... Screw nut 6 ... Adhesive surface 10 ... Vibration isolation device 100, 101, 102 ... Vibration isolation unit

Claims (10)

  Coil springs are respectively inserted through the holes of the flexible elastic sheet in which a plurality of holes having the same diameter are punched out, and the regions corresponding to the outer diameters of the coil springs are surrounded on both ends in the axial direction of the coil springs, leaving a connecting portion. A pair of unit rubber plates each having a pair of opposed slits that form islands corresponding to the region are disposed on the inner side thereof, and the island portions of the pair of unit rubber plates are interposed between them. An anti-vibration device comprising an anti-vibration unit that compresses a certain coil spring and sandwiches the flexible elastic sheet with an outer portion of the slit and is fixed integrally with a screw nut or a rivet that passes through the flexible elastic sheet.   The spring constant of each coil spring is 3.0 to 30 N / mm, and the spring constant of each island portion of the unit rubber plate is 3.0 to 35 N / mm. The combined spring constant of the pair of island portions sandwiching the coil spring and the coil spring is The vibration isolation device according to claim 1, wherein the vibration isolation device is 6.0 to 65 N / mm, and the support mass of the coil spring of one vibration isolation unit including one coil spring is 2 to 40 kg or less. .   3. The vibration isolation device according to claim 1, wherein the unit rubber plate of the vibration isolation unit has a disk shape and is provided with two arc slits.   The unit rubber plate has a rectangular shape, and two U-shaped slits are provided opposite to the center of the island portion so as to form a rectangular island portion. The vibration isolator according to claim 1 or 2.   A strip-like shape in which a plurality of rectangular holes of the same size are punched into the rectangular holes of the flexible elastic sheet, and coil springs are respectively inserted through the rectangular holes, and the upper and lower ends of each of the coil springs have a circular recess corresponding to the outer diameter of the coil spring. The unit rubber plate is engaged with the concave portion, and the unit rubber plate is brought into contact with the flexible elastic sheet while the coil spring is compressed via the unit rubber plate, and the rectangular shape of the flexible elastic sheet is obtained. An anti-vibration device characterized by being integrally fixed with a screw nut or a rivet penetrating through a hole.   The unit rubber plate is not integrally fixed with a screw nut or rivet, but is integrally formed at the time of unit rubber plate molding by a rubber mold, and the flexible elastic sheet is integrated with an adhesive. 6. The vibration isolator according to claim 5, wherein   The vibration isolation device according to claim 1, wherein a ratio of a height of the coil spring to a center diameter of the coil spring (coil spring height / coil spring center diameter) is 2 or less.   8. The vibration isolator according to claim 1, wherein the natural frequency of the coil spring is 4.5 to 8.5 Hz.   9. The vibration isolator according to claim 1, wherein a height of a portion where the coil spring is located is 50 mm or less.   10. The vibration isolator according to claim 1, wherein a cutting groove is attached to the flexible elastic sheet from which a circular or square hole is punched.

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