Vibration damping device

Abstract

To provide a vibration insulator which can achieve space saving of the vibration insulator without placing a coil spring in an inclined manner.SOLUTION: A vibration insulator 1 includes multiple spring units 100 elastically supporting a mounted device 10. Each spring unit 100 includes a coil spring 110 which elastically supports the mounted device 10. The coil spring 110 is arranged so that an axial direction CA1 of the coil spring 110 is set in a vertical direction. Each spring unit 100 is arranged so that a direction where the coil spring 110 is eccentrically arranged by a load applied by the mounted device 10 is directed to a centroidal position S1 of the mounted device 10 in a plan view.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an anti-vibration device that elastically supports a support object, such as various precision instruments that are susceptible to the effects of external vibrations, such as electron microscopes and electronic balances, and other mounted equipment, and suppresses the propagation of vibrations to the mounted equipment. [Background technology]

[0002] Precision instruments that are susceptible to external vibrations, such as electron microscopes, are supported by vibration isolation devices that use multiple units containing coil springs to prevent them from being affected by vibrations (see, for example, Patent Document 1).

[0003] In the vibration isolation device of Patent Document 1, a precision device is mounted on a movable plate, and multiple coil springs are arranged at the four corners of the fixed plate and the movable plate to support the load due to the weight of the precision device and the movable plate. A damper unit that has the function of attenuating vibrations is provided near the coil springs. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-77458 Summary of the Invention

[0005] In recent years, there has been a demand for miniaturization of such vibration isolation devices due to environmental factors such as the indoor environment in which the mounted equipment is installed, etc. Therefore, it is desirable for vibration isolation devices to be space-saving by shortening the distance between units, the distance between the units and other components, and the distance within the unit between the coil spring and the damping element.

[0006] Coil springs generally use conventional coil springs using round wire as the wire material. It is known that the axis of the coil spring may shift when it expands or contracts, resulting in eccentricity. When a coil spring becomes eccentric, the upper end of the coil spring shifts in position perpendicular to the coil axis compared to its initial state. When this misalignment occurs, the axis of the coil spring tilts in the eccentric direction, causing the outer shape of the coil spring to deform and become more oblique than its initial state, resulting in the upper end of the coil spring shifting laterally from its initial position. Therefore, if the distance between the coil spring and a nearby component is not sufficiently secured depending on the application, such as the supported object, the eccentricity of the coil spring may cause the outer surface of the coil spring to come into contact with a damping element, potentially reducing the vibration isolation function. In other words, in a vibration isolation device using a conventional coil spring, it is difficult to arrange the coil spring and a damper or other damping element in close proximity to each other.

[0007] In addition, in order to suppress eccentricity of the coil spring, it is possible to use a coil spring that uses a special, irregularly shaped wire material or a special coil spring in which the positions of the winding start end and winding end end are within a specified range, but this raises productivity issues such as increased costs and a complex structure that makes manufacturing difficult. [Problem to be solved by the invention]

[0008] An object of the present invention is to provide an anti-vibration device in which eccentricity of a coil spring is suppressed without using a special coil spring. [Means for solving the problem]

[0009] The vibration isolation device of the present invention is a vibration isolation device including a plurality of spring units that elastically support a support object, wherein the spring units each include a coil spring that elastically supports the support object, the coil springs are arranged so that the axial direction of the coil spring is approximately parallel to the direction of a load from the support object, and each spring unit is arranged so that the direction in which the coil spring becomes eccentric due to the load from the support object is toward the center of gravity of the load from the support object in a plan view. Here, the direction in which the coil spring becomes eccentric refers to the direction in which the center of the coil spring moves from a position before the load is applied to a position after the load is applied when one end of the coil spring is fixed and the other end is applied with the load, and means the direction of movement in a plan view when viewed from the axial direction of the coil spring.

[0010] The coil springs are arranged so that their axes are substantially parallel to the direction of the load from the support object, and each spring unit is arranged so that the direction of eccentricity due to the load from the support object is directed toward the center of the load from the support object. This prevents the coil springs from tilting in their axes due to the load from the support object. Therefore, even if the coil springs are arranged close to other components, the vibration isolation mechanism of the spring units is prevented from being hindered by the eccentricity of the coil springs, thereby saving space in the vibration isolation device. In particular, the vibration isolation device is suitable as a so-called passive vibration isolation device that does not involve vibration control such as feedback control. Each of the spring units may include other components such as a damping element, a support, a base plate, or a fixing member in addition to the coil spring, or may be a single coil spring.

[0011] In another embodiment, the multiple spring units are arranged so as to surround the center of gravity of the support object, at approximately equal positions from the center of gravity, and with approximately equal intervals between adjacent spring units, and the coil spring's winding start position on the support object side is arranged toward the center of gravity of the tower support object, so that the direction in which the coil spring becomes eccentric due to the load from the support object is toward the center of gravity of the support object in a plan view. The direction in which the coil spring becomes eccentric due to the load from the support object is identified by characteristics of the coil spring, and the coil spring is arranged using the characteristics of the coil spring as a marker so that the direction in which the coil spring becomes eccentric (laterally displaced) due to the load of the on-board equipment is toward the center of gravity of the on-board equipment in a plan view. By using the characteristics of the coil spring as a reference for the direction in which the coil spring becomes eccentric, it is possible to easily arrange the coil spring relative to the center of gravity of the on-board equipment. The characteristic of the coil spring may be a characteristic of the end portion of the coil spring, particularly the upper end portion thereof, such as the winding start position of the coil spring.

[0012] In another embodiment, the spring unit further includes a base member located on the opposite side to the mounted equipment to be supported, a plurality of second coil springs arranged to surround the first coil spring, which is the coil spring, a first spring seat connecting to the mounted equipment side of the second coil spring, a second spring seat connecting to the side of the first coil spring opposite the mounted equipment, and a connecting member having an intermediate portion fixing the first spring seat and the second spring seat, wherein the second coil spring is fixed to the base member on the side opposite to the mounted equipment so that it is positioned approximately equally apart from the first coil spring and its axial direction is vertical, and the plurality of second coil springs and the coil spring are connected in series via the first spring seat, the support pillar, and the second spring seat.

[0013] In another embodiment, the winding start positions of the second coil springs on the first spring seat side of the plurality of second coil springs are arranged on the first coil spring side in a plan view. As described above, the winding start positions of the second coil springs are used as a mark for the direction in which the coil spring is eccentric, and the second coil springs can be simply arranged so that the direction in which the second coil spring is eccentric faces the position of the center of gravity of the load applied to the second coil spring. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a vibration isolation device that can reduce the space required for the vibration isolation device without disposing the coil spring at an angle. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a schematic plan view showing the overall configuration of an anti-vibration apparatus according to an embodiment; [Figure 2] 1 is a perspective view showing the overall configuration of a spring unit according to an embodiment; [Figure 3] 1 is a vertical cross-sectional view showing the overall configuration of a spring unit according to an embodiment. [Figure 4] FIG. 10 is a plan view showing the eccentric direction of the spring unit according to the embodiment. [Figure 5] FIG. 2 is a plan view showing the start of winding of the coil spring according to the embodiment. [Figure 6] FIG. 4 is a partial enlarged view of the area surrounded by VI in FIG. 3. [Figure 7] FIG. 10 is a plan view showing the arrangement of spring units in the vibration isolation device of the reference example. DETAILED DESCRIPTION OF THE INVENTION

[0016] In the following, embodiments of the present technology will be described. The same or corresponding parts are denoted by the same reference characters, and description thereof may not be repeated.

[0017] In each embodiment described below, when referring to the number, amount, dimensions, etc., the scope of the present technology is not necessarily limited to the number, amount, dimensions, etc., unless otherwise specified. In the following embodiments, each component is not necessarily essential to the present technology, unless otherwise specified. The same reference numerals are used for the same or equivalent parts, and redundant descriptions may not be repeated. It is intended from the beginning that the configurations in the embodiments may be used in appropriate combination.

[0018] In this specification, the terms "comprise," "include," and "have" are open-ended. That is, when a certain configuration is included, other configurations may or may not be included. Furthermore, the present technology is not necessarily limited to those that achieve all of the effects mentioned in the present embodiment.

[0019] In the drawings used below, the arrows indicated by X and Y indicate directions that are 90 degrees apart on the same horizontal plane, and the arrow indicated by Z indicates the vertical direction. The coil springs shown below are coil springs (cylindrical coil springs) made of round wire. The axial direction of the coil springs is all aligned vertically (Z direction in the drawings). In this disclosure, the center of gravity of the onboard equipment refers to the center of gravity when the onboard equipment is viewed from above.

[0020] (Vibration isolation device 1) The overall configuration of a vibration isolation device 1 of this embodiment will be described with reference to Fig. 1. Fig. 1 is a schematic plan view showing the overall configuration of the vibration isolation device 1.

[0021] The vibration isolation device 1 in this embodiment is a vibration isolation device equipped with a plurality of spring units 100 that elastically support the mounted equipment 10, which is the support target. The mounted equipment 10 includes various precision equipment that is affected by external vibrations, such as electron microscopes and balances. In FIG. 1, the mounted equipment 10 is shown by a two-dot chain line. In the figure, the position of the center of gravity of the mounted equipment 10 is indicated as S1. This position of the center of gravity S1 indicates the position of the center of gravity when the mounted equipment 10 is viewed from above.

[0022] The vibration isolation device 1 has spring units 100 in four locations. The number of spring units 100 is selected as appropriate depending on the vibration isolation performance required of the vibration isolation device 1. The spring units 100 include coil springs 110 that elastically support the onboard equipment 10. The coil springs 110 are arranged so that the direction of the axis CA1 (see FIG. 3) of the coil springs 110 is vertical. The direction of the axis CA1 (see FIG. 3) of the coil springs 110 is approximately parallel to the load direction axis from the onboard equipment 10 that is to be supported.

[0023] The multiple spring units 100 surround the center of gravity S1 of the mounted equipment 10, and are arranged at positions such that the centers of the multiple spring units 100 are within a predetermined range from the center of gravity S1 to ensure vibration isolation performance, taking into consideration imbalances in the mounted equipment 10 due to individual differences in the mounted equipment 10. For example, in this embodiment, the multiple spring units 100 are arranged so that they are equidistant from the center of gravity S1 and are spaced equally apart from one another. The multiple spring units 100 are also preferably arranged so that the distances from the center of gravity S1 to the axis CA1 of the coil springs 110 of each spring unit 100 are all equal, and further so that the distances between the axes CA1 of adjacent spring units 100 are all equal.

[0024] Each spring unit 100 is arranged so that the eccentricity direction of the coil spring 110, which shifts laterally due to the load of the mounted equipment 10, is directed toward the center of gravity position S1 of the mounted equipment in a plan view. In FIG. 1, the eccentricity direction of the coil spring 110 arranged at the position of the first axis is the direction of arrow A1 in the figure. The eccentricity direction of the coil spring 110 arranged at the position of the second axis is the direction of arrow A2 in the figure. The eccentricity direction of the coil spring 110 arranged at the position of the third axis is the direction of arrow A3 in the figure. The eccentricity direction of the coil spring 110 arranged at the position of the fourth axis is the direction of arrow A4 in the figure.

[0025] In this way, each spring unit 100 is arranged so that the eccentric direction of the coil spring 110 due to the load of the on-board equipment 10 is directed toward the center of gravity position S1 of the on-board equipment 10 in a planar view. This alleviates the eccentric direction due to the load of the coil spring 110 and suppresses the tilt of the on-board equipment 10, thereby enabling stable vibration isolation of the on-board equipment 10.

[0026] 3, the spring unit 100 of this embodiment is provided with an oil damper 160 as a damping mechanism inside the coil spring 110, and the damping mechanism is provided adjacent to the coil spring 110 via a gap. If the coil spring 110 contracts due to a load and becomes eccentric, the axis CA1 of the coil spring 110 will tilt and the inner periphery of the coil spring 110 will come into contact with the outer periphery of the oil damper 160, hindering the contraction of the coil spring 110. Furthermore, a support pillar 140, which is a member for supporting the coil spring 110, is provided on the outer periphery of the coil spring 110. If the coil spring 110 becomes eccentric, the outer periphery of the coil spring 110 will come into contact with an inner side portion of the support pillar 140, hindering the contraction of the coil spring 110. In the vibration isolation device 1 of this embodiment, each spring unit 100 is arranged so that the eccentric direction of the coil spring 110 faces the center of gravity of the mounted equipment 10 that is to be supported, and therefore the coil spring 110 is prevented from coming into contact with the oil damper 160. Similarly, the coil spring 110 is prevented from coming into contact with the support column 140. In other words, since the axis CA1 of the spring unit 100 is prevented from tilting, the spring unit 100 can be positioned closer to components such as the oil damper 160, thereby reducing the size of the spring unit 100 and enabling the vibration isolation device 1 to be made more compact.

[0027] (Spring unit 100) Next, the specific configuration of each spring unit 100 will be described with reference to Figures 2 and 3. Figure 2 is a perspective view showing the overall configuration of the spring unit 100, and Figure 3 is a vertical cross-sectional view showing the overall configuration of the spring unit 100.

[0028] 2 and 3, the spring unit 100 is located on the opposite side from the mounted equipment 10 (the lower side in the drawings), and has a base member 12 below the coil spring 110. The spring unit 100 has the coil spring 110 as a first coil spring and a plurality of second coil springs 130. The plurality of second coil springs 130 are arranged at equal positions from the coil spring 110 and at equal intervals between adjacent second coil springs 130 so as to surround the coil spring 110.

[0029] In this embodiment, second coil springs 130 are arranged at four locations so as to surround coil spring 110. For example, the second coil springs 130 are arranged so that the distances from the position of axis CA1 of coil spring 110 to axis CA2 of each second coil spring 130 are all equal, and further, the distances from the position of axis CA2 of adjacent second coil springs 130 are all equal.

[0030] The spring unit 100 has a base member 12, a first spring seat 120, a support column 140, and a second spring seat 180. The second coil springs 130 are fixed to the base member 12 at the side opposite to the mounted equipment 10 (the lower side in the drawing) so that the axis CA2 (see FIG. 3) of the second coil springs 130 is oriented vertically. The second coil springs 130 do not need to be fixed at an angle to the base member 12 at their base member side ends connected to the base member 12, but can be fixed to the base member 12 so that the horizontal extension direction of the base member 12 and the imaginary end face of the base member side ends of the second coil springs 130 are approximately parallel. The support target of the second coil springs can be considered to be the first coil spring.

[0031] The ends of the multiple second coil springs 130 on the mounted device 10 side (upper side in the drawing) are fixed to the first spring seat 120. The first spring seat 120 has an annular shape and is provided in the center with a through-hole 120h through which the coil spring 110 passes.

[0032] An end of the coil spring 110 opposite to the mounted device 10 is fixed to the second spring seat 180. A flange 180f that protrudes radially outward is provided on the second spring seat 180. The flange 180f of the first spring seat 120 and the second spring seat 180 are fixed to each other via a support pillar 140. The support pillar 140 is provided as an intermediate portion that connects the first spring seat 120 and the second spring seat 180. A plurality of support pillars 140 are provided, and are arranged at equal intervals around the coil spring 110. Four second coil springs 130 are evenly arranged between adjacent support pillars 140. In this embodiment, the intermediate portion that connects the first spring seat 120 and the second spring seat 180 is provided as a support pillar, but it may be a cylindrical portion that surrounds the coil spring 110. The support pillar 140, which is the intermediate portion, functions as a connecting member that connects the coil spring 110, which is the first coil spring, and the second coil spring 130, together with the first spring seat 120 and the second spring seat 180. This connecting member connects the coil spring 110 and the second coil spring 130 in series.

[0033] An oil damper 160 serving as a damping mechanism is disposed inside the coil spring 110. The lower end of a cup 160b of the oil damper 160 is fixed to the base member 12. A leveling mechanism 170 is attached to a piston 160a of the oil damper 160. The end of the coil spring 110 on the mounted device 10 side (upper side in the drawing) is fixed to this leveling mechanism 170. A mounting plate 11 is fixed to the upper end of the piston 160a. A rotor may be provided on the piston 160a.

[0034] According to the spring unit 100 configured as described above, the plurality of second coil springs 130 and the coil spring 110 are connected in series via the first spring seat 120, the support column 140, and the second spring seat 180. Furthermore, a leveling mechanism 170 and an oil damper 160 are disposed in the spring system of the plurality of second coil springs 130 and the coil spring 110. Because the second coil spring 130 is provided outside the coil spring 110 and the second coil spring 130 and the coil spring 110 are provided in series, the spring unit 100 can be made small in the direction in which the coil spring 110 expands and contracts, and can also be made small in the radial direction of the coil spring 110. In this embodiment, tilting of the axis CA1 of the coil spring 110 is suppressed, and therefore the second spring seat 180 does not need to be tilted, and therefore the second spring seat 180 can be easily provided.

[0035] (Eccentricity suppression effect of spring unit 100) The eccentricity suppression effect of the spring unit 100 will be described with reference to Figures 4 and 5. Figure 4 is a plan view showing the eccentricity direction of the spring unit 100. Figure 4 illustrates the spring unit 100 arranged on one axis shown in Figure 1, but the same applies to spring units 100 arranged on two to four axes.

[0036] As described above, in the spring unit 100 arranged on one axis, the winding start position 110S of the coil spring 110 is arranged on the side of the center of gravity position S1 of the mounted equipment 10. Here, as shown in FIG. 5, the coil spring 110 is arranged so that the center of gravity position S1 side of the winding start position 110S of the coil spring 110 faces the direction of arrow B in the figure. Referring again to FIG. 4, this suppresses eccentricity (lateral slip) of the coil spring 110 in the direction A1 in the figure when a load is applied to the coil spring 110. Note that, for the coil spring 110 used in this embodiment, the eccentric direction coincides with the winding start position, so the coil spring is arranged based on the winding start position. However, if the eccentric direction does not coincide with the winding start position, the coil spring may be arranged so that a mark serving as a reference for the eccentric direction faces the center of gravity position.

[0037] On the other hand, when the vibration isolation device 1 is viewed as a whole, a load from the on-board equipment 10 is applied to the coil spring 110 in the Z1 direction in the figure. Because the coil spring 110 is arranged to suppress eccentricity, the axis of the coil spring 110 is suppressed from tilting in the eccentric direction from the Z1 direction, and the coil spring 110 is suppressed from interfering with nearby members such as the second coil spring 130 and the oil damper 160. As a result, tilting of the coil spring 110 and the on-board equipment 10 is suppressed, and vibration isolation of the on-board equipment 10 can be stably achieved.

[0038] As shown in FIG. 4 , the winding start position 130S of the second coil spring 130 employed in each spring unit 100 is preferably located closer to the coil spring 110 in a plan view. This suppresses eccentricity in the second coil spring 130, similar to the coil spring 110. The second coil spring 130 used in this embodiment is also positioned based on the winding start position because the eccentric direction coincides with the winding start position. However, if the eccentric direction does not coincide with the winding start position, the second coil spring 130 may be positioned so that the reference position for the eccentric direction faces the center of gravity. Similarly to the coil spring 110 described above, the second coil springs 130 are also positioned so that the center of arrangement of the second coil springs 130 is within a predetermined range from the center of gravity position S1 to ensure vibration isolation performance.

[0039] The relative positions of the coil spring 110 and the second coil spring 130 when the spring unit 100 of this embodiment is employed will be described with reference to Fig. 6. Fig. 6 is a partial enlarged view of the area surrounded by VI in Fig. 3, and is a diagram showing the clearance between the coil spring 110 and the second coil spring 130.

[0040] In this embodiment, the axis CA1 of the coil spring 110 and the axis CA2 of the second coil spring 130 are both disposed along the vertical direction. Therefore, the gap (clearance) C2 between the inner periphery of the coil spring 110 and the outer wall of the oil damper 160 can be designed to be a minimum value. Similarly, the gap (clearance) C1 between the outer periphery of the coil spring 110 and the inner wall of the through hole 120h of the first spring seat 120 can also be designed to be a minimum value.

[0041] (Compared to a reference vibration isolation device) The performance of the vibration isolation device of the reference example will be compared with that of the vibration isolation device of this embodiment with reference to Fig. 7. Fig. 7 is a plan view showing the arrangement of spring units 100Z in the vibration isolation device 1Z of the reference example. The basic configuration of the spring units 100Z in the vibration isolation device 1Z shown in Fig. 7 is the same as that of the spring unit 100 of this embodiment.

[0042] 1, the spring units 100 of this embodiment are arranged such that the eccentric direction of the coil springs 110 is directed toward the center of gravity position S1 of the mounted equipment 10 in a plan view due to the load of the mounted equipment 10. On the other hand, in the vibration isolation device 1Z of the reference example, the spring units 100Z are arranged such that the eccentric direction of the coil springs 110 is directed outward in a windmill shape due to the load of the mounted equipment 10 on the spring units 100Z.

[0043] Specifically, in the drawing, the eccentric direction A1 of the coil spring 110 of the one-axis spring unit 100Z is downward, the eccentric direction A2 of the coil spring 110 of the two-axis spring unit 100Z is rightward, the eccentric direction A3 of the coil spring 110 of the three-axis spring unit 100Z is upward, and the eccentric direction A4 of the coil spring 110 of the four-axis spring unit 100Z is leftward.

[0044] The specifications of spring unit 100 and spring unit 100Z are the same. Referring to Fig. 2, when the load of mounted equipment 10 is 500 kg, ordinary coil springs made of metal wire wound in a spiral shape and shaped like a cylinder, which can support a predetermined load depending on the position, are used for coil spring 110 and second coil spring, and oil dampers are employed to appropriately fabricate spring units, and experiments were conducted. As a result, it was confirmed that the vibration isolation performance of vibration isolation device 1 of this embodiment is improved by about 10% in the vibration band of 10 Hz, compared to the vibration isolation performance of vibration isolation device 1Z of the reference example.

[0045] In the above embodiment, the spring unit 100 is configured as a vibration isolation unit by combining the coil spring 110, the second coil spring 130, and the oil damper 160, but the configuration is not necessarily limited to this. For example, the spring unit 100 may be configured using only the coil spring 110, and each spring unit 100 may be arranged so that the direction of eccentricity (lateral deviation) of the coil spring 110 faces the center of gravity position S1 of the mounted equipment in a plan view. A combination of only the coil spring 110 and the second coil spring 130 is also possible.

[0046] Although the embodiments of the present technology have been described above, the embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present technology is defined by the claims, and it is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0047] 10 mounted equipment, 11 mounting plate, 12 base member, 100 spring unit, 110 coil spring, 120 first spring seat, 120h through hole, 130 second coil spring, 140 support, 160 oil damper, 160a piston, 170 leveling mechanism, 180 second spring seat, 180f flange, CA1, CA2 axis, S1 center of gravity position.

Claims

1. A vibration isolation device having a plurality of spring units that elastically support an on-board device, Each of the spring units comprises: a coil spring that elastically supports the mounted equipment; The coil spring is arranged so that the axial direction of the coil spring is vertical, the coil spring has an eccentric direction in which it shifts laterally due to the load of the mounted equipment, Each of the spring units is arranged so that the eccentric direction of the coil spring is directed toward the center of gravity of the mounted equipment in a plan view. Vibration isolator.

2. the plurality of spring units are arranged at substantially equal positions from the center of gravity of the mounted equipment so as to surround the center of gravity, and the intervals between adjacent spring units are substantially equal; The coil spring has a winding start position on the mounted equipment side that is located toward the center of gravity of the mounted equipment, so that the direction in which the coil spring is eccentric due to the load of the mounted equipment is toward the center of gravity of the mounted equipment in a plan view. The vibration isolation device according to claim 1 .

3. The spring unit includes: a base member located on the opposite side of the mounted equipment to be supported; a plurality of second coil springs arranged to surround the first coil spring; a first spring seat connected to the second coil springs on the mounted equipment side; a second spring seat connected to the first coil spring on the opposite side from the mounted device; a support pillar as an intermediate portion that fixes the first spring seat and the second spring seat; further comprising the second coil spring is fixed to the base member on the side opposite to the mounted equipment so that the second coil spring is positioned at approximately equal intervals from the first coil spring and has an axial direction aligned vertically; the plurality of second coil springs and the coil spring are connected in series via the first spring seat, the support pillar, and the second spring seat; 3. The vibration isolation device according to claim 1.

4. The winding start positions of the second coil springs on the first spring seat side of the plurality of second coil springs are arranged on the coil spring side in a plan view. The vibration isolation device according to claim 3 .

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