JP2002021927A - Base isolation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a base isolation device capable of preventing the occurrence of large local stress and a shock in a base isolation object when seating the base isolation object by exhausting sealed gas from these air springs while attaining a long period of the base isolation object by using the air springs capable of minimizing the height. SOLUTION: The air springs 13 comprise an inside member 15 arranged on the foundation side, an outside member 16 covering an upper end part of the inside member 15 at a proper interval and arranged on the building side and a rolling seal member 17 for sealing these inside member 15 and outside member 16 while allowing a relative movement of both. A seating shock absorber 30 for absorbing the shock and the stress when seating a building is arranged in vertical directional clearance between a receiving plate 22 arranged in an opening part 15b of the inside member 15 and an end plate 16a of the outside member 16. The seating shock absorber 30 comprises laminated rubber 31 arranged in an under surface central part of the end plate 16a and a sliding material 32 arranged on an upper surface of the receiving plate 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a vibration isolator,
In particular, the present invention relates to a vibration isolation device that enables an effective long period of a structure using an air spring.

[0002]

2. Description of the Related Art An anti-vibration device is a base to which vibrations of the ground and floor are input, and a vibration-damping object such as a building, precision equipment, other equipment or devices that dislike vibration, and articles installed on the base. A so-called period increasing means is provided between the base and the vibration-isolating target object. The vibration input to is reduced.

[0003] Various elastic bodies represented by laminated rubber, coil springs, air springs and the like are employed as the period increasing means. In particular, since the air spring is a spring that utilizes the compression elasticity of air, it is softer than other springs, and exhibits excellent characteristics in prolonging the period of the vibration-isolated object. For this reason, it is preferable to use an air spring as a vibration isolator, and an excellent vibration isolator can be provided by utilizing the vertical spring force and horizontal spring force (lateral rigidity) of the air spring. In this case, a vertical vibration isolator is configured by using the vertical spring force, and a three-dimensional vibration isolator is configured by using both the vertical spring force and the horizontal spring force.

A bellows type air spring is generally used as the air spring. A typical structure thereof is a bellows-shaped cylindrical rubber bellows having peaks and valleys formed in the circumferential direction. , And a metal face plate that covers the top and bottom,
An intermediate ring fitted to the valley portion of the rubber bellows. The vertical spring of the air spring is obtained by the elastic force when the air sealed in the rubber bellows is compressed with the expansion and contraction of the rubber bellows,
The horizontal spring is obtained by the restoring force generated depending on the enclosed air pressure and the rigid nature of the rubber bellows.

[0005] By the way, the bellows-type air spring, which has a reduced height of rubber bellows, that is, a number of bellows steps, is used in order to enhance the supportability of the vibration-isolated object with a large load.
Since the volume of the air chamber is small, the air pressure rises excessively with respect to the relative vertical amplitude between the base and the vibration-isolated object, and the rubber bellows expand beyond the allowable amount, resulting in durability. Problems arise. Therefore, in order to increase the volume of the air chamber in order to suppress an excessive rise in the air pressure, the number of rubber bellows is increased to increase the air spring. However, when the air spring is raised in this way, the rubber bellows easily buckles, and it becomes difficult to cope with a large load and a large amplitude intended for a large earthquake.

[0006]

Therefore, as a method for avoiding the buckling of the rubber bellows, the present inventor proposes to use a rolling seal type air spring instead of the bellows type air spring. The rolling seal type air spring is provided with a solid inner member and a hollow cylindrical outer member which are arranged concentrically at appropriate intervals, and a horizontal gap between the outer periphery of the inner member and the inner periphery of the outer member. And a flexible cylindrical rolling seal member that is folded back so as to hang down. The rolling seal member is folded back at its intermediate portion, its inner peripheral portion is fitted along the outer periphery of the inner member, and its end is hermetically attached to the upper end of the inner member, and its outer peripheral portion is placed along the inner periphery of the outer member. The end is hermetically attached to the upper end of the outer member to seal an air chamber formed between the inner and outer members.

When the inner member and the outer member are vertically displaced relative to each other due to vibration input, the folded portion of the rolling seal member is lifted up by a horizontal gap,
It can be brought down. At this time, the pressure acting on the air chamber acts on the rolling seal member, and the folded portion of the rolling seal member is a portion that closes a horizontal gap between the inner member and the outer member, and the folded portion is It will receive the pressure in the air chamber.

By the way, if an air spring is used as the lengthening means as described above, when it becomes necessary to discharge the enclosed air for repair and inspection, the air is discharged from the plurality of air springs. The volume is uniform and care is taken to ensure that the outer member lands on the inner member at all air springs simultaneously.

However, in practice, the vibration-isolated object, for example, a structure has a dimensional error in the construction, and a slight difference is generated in the air discharge speed from each air spring, so that all the air springs are displaced. Therefore, it is considered to be extremely difficult to simultaneously seat the vibration-isolation target. If there is a difference in seating timing between the air springs in this manner, a larger local stress is generated in the air spring portion that lands earlier on the vibration-isolated object,
In particular, when the seat is urgently seated, a large impact force may act on the vibration-isolated object. In addition, such air discharge from the air spring occurs not only during repair and inspection, but also when the air spring is damaged due to an accident such as a large earthquake.
Also in this case, a particularly large impact force is input to the vibration-isolation target when the user is seated.

In view of the above, the present invention has been made in view of the above-mentioned conventional problems, and achieves a longer period of a vibration-isolated object by using an air spring whose height can be kept low. It is an object of the present invention to provide a vibration isolator capable of reducing occurrence of a large local stress or impact on a vibration-isolation target when the vibration-isolation target is seated due to discharge of a sealed gas.

[0011]

In order to achieve the above object, a vibration isolator according to the present invention is provided between a base to which vibration is input and an object to be isolated above the base. An inner member protruding from one side of the vibration target toward the other side, and an inner member protruding from the other side of the base or the vibration-isolation target toward the one side, and appropriately spaced apart in the vertical and horizontal directions. An outer member of a hollow cylindrical body surrounding the outer periphery of the member, and the outer member is folded back so as to hang down in a horizontal gap between the inner periphery of the outer member and the outer periphery of the inner member. The inner end of the base member is hermetically attached to the inner member, and the outer peripheral portion thereof is hermetically attached to the outer member along the inner periphery of the outer member. Vibration target Along with the vertical relative displacement of the inner member and the outer member with the vertical relative displacement of the inner member and the outer member, the inner member and the outer member are displaced up and down in the horizontal gap, and from the horizontal gap between the outer member and the inner member. A flexible cylindrical rolling seal member forming a gas-enclosed space, and a seat cushioning device for seating the vibration isolation target on a base in a vertical gap between the inner member and the outer member. The shock absorbing device absorbs shocks and stresses when the vibration-isolated object is seated.

Preferably, the seat cushioning device includes an elastic member provided on one of the inner member and the outer member, and a sliding member provided on the other.

[0013]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. 1 to 4 show an embodiment of a vibration isolator according to the present invention. FIG. 1 is a schematic configuration diagram of the whole vibration isolator, FIG. 2 is an enlarged sectional view of an air spring, and FIG. FIG. 4 is an enlarged cross-sectional view of the seat cushioning device.

The vibration isolator 10 of the present embodiment shows an example in which a building 11 is used as a vibration isolating object. As shown in FIG. 1, an air spring 13 is provided between the building 11 and a foundation 12 as a base. It is arranged to prolong the natural vibration of the building 11 and to provide a seat cushioning device 30 in a vertical gap inside the air spring 13 so as to absorb the shock and stress when the building 11 is seated. I have.

The air spring 13 is formed as a rolling seal type air spring (hereinafter, simply referred to as an air spring). As shown in FIG. 2, the air spring 13 is an inner member 15 projecting upward from the foundation 12 side. And an outer member 16 of a hollow cylindrical body projecting downward from the building 11 side and surrounding the outer periphery of the inner member 15 at appropriate intervals in the vertical and horizontal directions, and the inner member 15 and the outer member 16. And a rolling seal member 17 that seals the space between them while permitting relative movement between them.

The inner member 15 protrudes from a substrate 15a fixed to the base 12, and an upper end facing the outer member 16 is opened through an opening 15b.
A hollow chamber 15c communicating with the opening 15b is formed to have a hollow cylindrical shape, and a lower end of the inner member 15 is integrally fixed to the substrate 15a and closed.

On the other hand, the outer member 16 has an inverted U-shaped cross section formed by an end plate 16a opposed to the upper end of the inner member 15 at an appropriate interval and a peripheral wall 16b suspended annularly from the outer periphery of the end plate 16a. As shown in FIG. 3, the peripheral wall 16b concentrically surrounds the outer periphery of the upper end portion of the inner member 15 at appropriate intervals, and the end plate 16a is provided on the lower surface of the building 11. Fixed. A space closed by the end plate 16a of the outer member 16 and the rolling seal member 17 from the hollow chamber 15c of the inner member 15 via the opening 15b is formed as a main gas filled space 18.

The rolling seal member 17 is disposed in a horizontal gap between the outer periphery of the inner member 15 and the inner periphery of the peripheral wall 16b of the outer member 16, and is disposed outside the main gas filled space 18 side. Seal member 19 and second seal member 20 arranged in parallel toward
It is constituted by and. These first and second seal members 1
Reference numerals 9 and 20 are each formed of a fiber-reinforced rubber as a raw material so as to form a cylindrical shape in a natural state, and a middle portion thereof is folded back so that one side is turned over. It is attached across the member 16.

That is, the first and second seal members 19, 2
When 0 is folded back at the intermediate portion, one end on the flipped side becomes outer peripheral portions 19a and 20a, and the other end on the opposite side becomes inner peripheral portions 19b and 20b. Then, the inner peripheral portions 19b and 20b are made to extend along the outer periphery of the upper end portion of the inner member 15, and the outer peripheral portions 19a and 20a are made to extend along the inner periphery of the peripheral wall 16b of the outer member 16. At this time, the inner peripheral parts 19b, 20b and the outer peripheral parts 19a, 20
Each end of a is air-tightly fixed to the inner member 15 and the outer member 16 along which each ends. In this state, the first and second seal members 19 and 20 are folded back 19c,
20c hangs down between the outer periphery of the inner member 15 and the inner periphery of the outer member 16 to seal between them, and the inner member 15, the outer member 16 and the first seal member 19 are sealed.
Are formed as the main gas filled space 18, and a space surrounded by the first seal member 19 and the second seal member 20 is formed as a sub gas filled space 21.

Therefore, the air spring 1 constructed as described above is used.
3 is the basics 1 when vibrations such as earthquakes are input.
When the building 2 and the building 11 are relatively vertically displaced, the inner member 15 and the outer member 16 are vertically displaced relative to each other, and the change in volume in the main gas-filled space 18 formed between the two members. The air pressure is changed accordingly. When the volume of the main gas filled space 18 is changed in this manner, the first and second seal members 19 and 20 have the inner peripheral portions 19b and 20b and the outer peripheral portions 19a and 20a formed on the outer periphery of the inner member 15 and the inner periphery of the outer member 16. They will be moved up and down alternately.

The first and second seal members 19, 2
The air pressure P2 lower than the air pressure P1 of the main gas-filled space 18 is sealed in the sub-gas-filled space 21 formed between 0, and the differential pressure (P1-P2) is applied to the folded portion 18c of the first seal member 19. ) And a low air pressure P2 is applied to the folded portion 19c of the second seal member 20, so that the folded portions 19c, 20c
To reduce the substantial pressure borne by.
As a result, the durability of the rolling seal member 18 is improved, and the supporting load of the air spring 13 can be increased.

The air spring 13 thus constructed
When the inner member 15 and the outer member 16 are relatively displaced in the vertical direction due to the vertical vibration component of the input vibration, the pressure in the main gas sealing space 18 is changed accordingly, and the compression elasticity of the sealed gas at this time is changed. Thus, a softer vertical spring can be obtained, and the natural period of the building 11 in the vertical direction can be made longer to thereby effectively perform vertical vibration isolation.

In this case, since the air spring 13 is formed as a rolling seal type, when the inner member 15 and the outer member 16 are relatively displaced in the vertical direction, the first and second seal members along the outer periphery of the inner member 15 are provided. The inner peripheral portions 19b and 20b of the outer member 16 and the first and
The outer peripheral portions 19a, 20a of the second seal members 19, 20 are alternately moved up and down to form the main gas-filled space 1
Since the change in the volume of the air spring 8 is allowed, the lengthening of the period can be achieved while keeping the height of the air spring 13 low.

When the inner member 15 and the outer member 16 are relatively displaced in the horizontal direction by the horizontal vibration component of the input vibration, the restoring force generated depending on the gas pressure in the main gas filling space 18 and the first force are reduced. , A soft horizontal spring is obtained by the rigid properties of the second seal members 19 and 20, whereby the natural period of the building 11 in the horizontal direction can be lengthened to effectively isolate the horizontal vibration. Therefore, the vibration isolation device 10 of the present embodiment can achieve three-dimensional vibration isolation by effectively utilizing the vertical vibration isolation function and the horizontal vibration isolation function of the air spring 13.

That is, in the rolling seal type air spring 13 of the present embodiment, the horizontal spring characteristic is much dependent on the internal pressure as compared with the bellows type used conventionally.
The spring characteristic shows a clean linear characteristic even with a large amplitude, and excellent performance as a spring can be expected. In other words, when the rolling seal type air spring 13 is sheared in the horizontal direction, the rolling seal member 17 is deformed.
The folded portions 19c and 20c are deformed downward with a narrow horizontal gap on the compression side, and deformed upward with a wide horizontal gap on the tension side. For this reason, a pressure action effective area in the horizontal direction is generated during that time, and the internal gas pressure acts to create a restoring force in the horizontal direction, which becomes a horizontal spring characteristic.

Here, a vertical gap between the inner member 15 and the outer member 16, that is, between the receiving plate 22 provided in the opening 15b of the inner member 15 and the end plate 16a of the outer member 16 in the present embodiment. In addition, a seat cushioning device 30 for absorbing a shock or stress when the building 11 is seated is provided. At this time, the receiving plate 22 is integrated so as to cover the inner periphery of the upper end portion of the inner member 15, and the lower part of the center of the receiving plate 22 is supported by a support column 23 provided between the receiving plate 22 and the substrate 15 a. At this time, a plurality of openings 15b communicating with the hollow chamber 15c of the inner member 15 and the gas-filled space 18 are formed in the periphery of the receiving plate 22 as circular holes as shown in FIG.

As shown in FIG. 4, the seat cushioning device 30 includes a laminated rubber 31 as an elastic member provided at the center of the lower surface of the end plate 16a and a sliding member 32 provided on the upper surface of the receiving plate 22. It is configured with. The laminated rubber 31
Rubber 31a and steel plate 31 are used in the same manner as the normally used vibration isolating rubber.
b are alternately laminated and integrated. The sliding member 32 is formed of a member having a low friction surface such as a stainless plate or a flat plate treated with Teflon (registered trademark).

In a normal state where the building 11 is supported by the air spring 13, a gap δ smaller than the vertical distance between the inner member 15 and the outer member 16 is provided between the laminated rubber 31 and the sliding member 32 (see FIG. 4). Is provided so that the lower end of the laminated rubber 31 is seated on the sliding member 32 when the gas filled in the air spring 13 is removed. The sliding material 32 is wider than the tip (lower end) area of the laminated rubber 31 in order to allow the relative movement of the laminated rubber 31 in the horizontal direction, and both are relatively slidable.

In the present embodiment, as shown in FIG. 4, a sub-sliding material 33 is also provided on the lower end surface of the laminated rubber 31. Is further reduced. In this case, if a sufficient sliding function can be obtained between the lower surface of the laminated rubber 31 and the sliding material 32, the auxiliary sliding material 33 is not necessarily required.

With the above configuration, the vibration isolator 1 of this embodiment is
0, the use of the rolling seal type air spring 13 makes it possible to provide a large capacity main gas sealing space 18 between the inner member 15 and the outer member 16. While keeping the height low, the natural vibration cycle of the building 11 can be extended by the soft vertical and horizontal springs to achieve effective three-dimensional vibration isolation.

By using the air spring 13 as a means for lengthening the period, the sealed gas is discharged so that the air spring 13 can be periodically inspected. Inner member 15 and outer member 1
The laminated rubber 31 is seated on the sliding member 32 of the receiving plate 22 with the upper and lower members 6 spaced apart from each other. Thereby, building 1
1 can be stably seated on the base 12 side.

Further, the seat cushioning device 30 of the present embodiment
In the case of, for example, when there is a difference in the gas discharge speed between the respective air springs 13, the seating timing of the building 11 on the foundation 12 side is different. At this time, the building 1 is sequentially compressed and deformed from the laminated rubber 31 seated first.
1 is seated at the installation position of each air spring 13, and finally, the seat cushioning devices 30 of all the air springs 13 act to activate the building 1.
1 is stably seated on the base 12 side.

Therefore, when the building 11 is lowered with a slight inclination due to the state of gas discharge from the air spring 13 or due to a dimensional error of the building 11 itself, some of the air springs Even when the seat cushioning device 30 of the thirteenth seats first, the local stress and impact generated in the building 11 due to the compression deformation of the laminated rubber 31 can be reduced, thereby preventing the building 11 from being damaged. be able to. In addition, by providing the laminated rubber 31 in this manner, the air spring 13 is damaged by an accident such as a large earthquake,
Even in the case where the filled gas is suddenly discharged and the building 11 descends, the impact inputted to the building 11 can be buffered and absorbed by the laminated rubber 31, so that the building 11 can be protected.

In the present embodiment, the sliding material 32 on the mating side on which the laminated rubber 31 is seated is wider than the lower end area of the laminated rubber 31 and horizontal relative movement between these two members is allowed. Even if an earthquake occurs when the shock absorber 30 is in a seated state, this can be absorbed to some extent. In other words, the vertical vibration component of the earthquake is absorbed by the compressive deformation of the laminated rubber 31, and the horizontal vibration component is absorbed by the sliding of the laminated rubber 31 and the sliding material 32, thereby reducing the vibration energy input to the building 11. As a result, a minimum vibration isolation effect can be exhibited. In this case, when the sub-sliding material 33 is provided on the lower end surface of the laminated rubber 31, the relative movement in the horizontal direction is performed more smoothly.

In the present embodiment, the seat cushioning device 30 uses the laminated rubber 31 as the end plate 16a of the outer member 16.
Although the sliding member 32 is provided on the receiving plate 22 side, the sliding members 32 may be provided on the receiving plate 22 and the sliding member 32 may be provided on the end plate 16a by reversing them.

FIGS. 5 and 6 show another embodiment, in which the same components as those in the above embodiment are denoted by the same reference numerals, and the description thereof will be omitted. 5 is an enlarged sectional view of the air spring, and FIG. 6 is a sectional view taken along the line BB in FIG. 5. In the vibration isolator 10 of this embodiment, the seat cushioning device 30 is replaced with a laminated rubber 31 similarly to the above embodiment. And a sliding member 32, each of which is provided in a vertical gap between the upper end of the inner member 15 and the lower surface of the end plate 16 a of the outer member 16.

A plurality of the laminated rubbers 31 are provided at predetermined intervals on a circular end surface at the upper end of the inner member 15 formed in a cylindrical shape, and the sliding material 32 is attached to the lower surface of the end plate 16a. The sliding member 32 is formed in a ring shape having a width larger than the diameter of the front end (lower end) of the laminated rubber 31. The ring-shaped sliding member 32 is arranged concentrically with the inner member 15.

Therefore, in the vibration isolator 10 of this embodiment, similarly to the above-described embodiment, the seat cushioning device 30 is seated with the discharge of the sealed gas from the air spring 13 so that the building 11 is mounted on the foundation 12. Side, and even if there is a deviation in seating timing between the air springs 13, local stress and impact generated in the building 11 due to compression deformation of the laminated rubber 31 can be reduced.
1 can be prevented from being damaged. Also, when an earthquake occurs while the seat cushioning device 30 is in the seated state, the vertical vibration component can be absorbed by the laminated rubber 31 and the horizontal vibration component can be absorbed by the laminated rubber 31 and the sliding material 3.
2 can be absorbed by sliding.

Also in this embodiment, the seat cushioning device 30 is configured such that the laminated rubber 31 and the sliding material 32 are arranged in reverse, and the laminated rubber 31 is attached to the end plate 16a of the outer member 16 and the sliding material 32 May be provided on the circular end face of the inner member 15, but in this case, it is necessary to increase the width of the circular end face in order to secure the sliding range of the laminated rubber 31.

Further, when supporting the building 11 on the foundation 12, it is preferable to support it at the pillar position of the building 11,
In consideration of this point, if the laminated rubber 31 is attached to the upper building 11 side so that the installation position of the laminated rubber 31 coincides with the column position, when the building 11 is seated on the foundation 12 side, Advantageously, it can be securely supported at the position.

On the other hand, if the laminated rubber 31 is hung from the upper building 11 side and attached, a downward pulling force always acts on the laminated rubber 31 by its own weight, and there is a concern that the laminated rubber 31 may be deteriorated. To put the laminated rubber 31 on the lower foundation 1
What is necessary is just to attach to two sides. As another method, when the laminated rubber 31 is hung from above, the laminated rubber 3
A wire or the like for supporting its own weight may be hung on 1.

By the way, the vibration isolator 10 of each of the above embodiments is used.
In the air spring 13 used for the first embodiment, the rolling seal member 18 is composed of two first and second seal members 19 and 20,
Of course, one or three or more sheets can be used. Also, the inner member 15 is the foundation 12 side, and the outer member 16 is the building 1
Although provided on one side, a similar function can be obtained by disposing the inner member 15 and the outer member 16 in reverse. In addition, although the earthquake has been described as an example of the input vibration, it is needless to say that the same function can be obtained even in the case of traffic vibration or daily vibration.

[0043]

As described above, the anti-vibration device of the present invention uses a rolling seal type air spring whose height can be kept low, thereby increasing the vertical period and horizontal direction of the object to be isolated. In this case, in the vertical gap between the inner member and the outer member constituting the air spring, a seat cushioning device is provided when the vibration-isolation target is seated on the base. When the vibration-isolated object descends due to the discharge of the enclosed gas from the air springs, even if there is a deviation in the landing timing between the air springs, it absorbs and absorbs local stress and impact that may occur on the vibration-isolated object. The vibration isolation target can be protected.

Further, since the seat cushioning device is provided with an elastic member provided on one of the inner member and the outer member and a sliding member provided on the other, an earthquake occurs when the seating cushioning device is seated. Even when this occurs, the vertical vibration component is absorbed by the compressive deformation of the elastic member, and the horizontal vibration component is absorbed by the sliding of the elastic member and the sliding material, so that a minimum three-dimensional vibration isolation can be ensured. .

[Brief description of the drawings]

FIG. 1 is an overall schematic configuration diagram showing an embodiment of a vibration isolation device according to the present invention.

FIG. 2 is an enlarged sectional view of an air spring used in one embodiment of the vibration isolator according to the present invention.

FIG. 3 is a cross-sectional view taken along the line AA in FIG. 2, showing one embodiment of the vibration isolator according to the present invention.

FIG. 4 is an enlarged sectional view of a seat cushioning device used in one embodiment of the vibration isolator according to the present invention.

FIG. 5 is an enlarged sectional view of an air spring used in another embodiment of the vibration isolator according to the present invention.

FIG. 6 is a sectional view taken along the line BB in FIG. 5, showing another embodiment of the vibration isolator according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Vibration isolation device 11 Building 12 Foundation 13 Rolling seal type air spring 14 Seating cushioning device 15 Inner member 16 Outer member 17 Rolling seal member 18 Gas sealing space 19a, 20a Outer peripheral portion 19b, 20b Inner peripheral portion 19c, 20c Folded portion 22 Receiving Board 30 seat cushioning device 31 laminated rubber 32 sliding material

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F16F 9/05 F16F 9/05

Claims (2)

[Claims] An inner member provided between a base to which vibration is input and a vibration-isolation target above the base, and protruding from one of the base or the vibration-isolation target toward the other side; An outer member of a hollow cylindrical body protruding from the other of the base or the vibration-isolation target object toward one side and surrounding the outer periphery of the inner member at appropriate intervals in the vertical and horizontal directions; Folded and arranged so as to hang down in a horizontal gap between the inner periphery and the outer periphery of the inner member, the inner peripheral portion of the inner member is hermetically attached to the inner member along the outer periphery of the inner member, An outer end portion of the outer member is hermetically attached to the outer member along an inner periphery of the outer member. relative A flexible cylindrical rolling seal member that is raised and lowered in the horizontal gap in accordance with the position and forms a gas-enclosed space from the horizontal gap to the outer member and the inner member. A vibration isolator, wherein a seat cushioning device is provided in a vertical gap between the inner member and the outer member when the vibration isolating object is seated on a base. 2. The vibration isolator according to claim 1, wherein the seat cushioning device includes an elastic member provided on one of the inner member and the outer member, and a sliding member provided on the other. .