JP2008082389A - Multistage gas spring vibration resistant device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance load support performance, by sufficiently enlarging the total pressure receiving area of air springs 3 and 4, while preventing the formation of a low rigidity part on the support object side (the sprung side), in a multistage air mount A having the air springs 3 and 4 of at least upper-lower two stages. <P>SOLUTION: Mutual bottom plate part (a bottom plate 1 and an upper plate 7) being the foundation side (the unsprung side) in the upper stage and lower stage air springs 3 and 4, are connected by a column composed of a shaft member 5 and a center block 6. While, mutual top plate parts (a top plate 23 and a lower plate 11) being the support object side (the sprung side), are connected by an outer peripheral wall 20 formed by combining thick wall members 21 to 24, and are temporarily constituted in a box shape. Right-left horizontal air springs 26 and 27 are arranged in the middle of the upper stage and lower stage air springs 3 and 4. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vibration isolator that supports a precision device or the like by a gas spring and suppresses transmission of vibration from the foundation side, and is a multistage type in which at least two upper and lower gas springs are provided. It belongs to the technical field of the structure of things.

  Conventionally, as this type of gas spring type vibration isolator, as disclosed in, for example, Patent Documents 1 and 2, etc., it is vertically stacked between a fixed base on the base side and a movable base on the supported body side. By forming a plurality of pressure air chambers, that is, air springs, the total pressure receiving area of the plurality of air springs can be ensured and the required output (maximum support load) can be obtained without enlarging the installation area. A multi-stage type as described above is known.

  For example, in Patent Document 1, a pressure air chamber is formed between a ceiling portion (an upper circular plate) of a box-shaped fixing base installed on the foundation side and a disk positioned above the ceiling portion, and the upper air A pillar (shaft) that constitutes a spring, passes through the through hole in the ceiling part downward from the disk, and hangs down inside the fixed base, and is attached to the lower end of the disk and the bottom of the fixed base. A lower air spring is formed by forming a pressure air chamber between the two.

That is, in the conventional air spring vibration isolator, the disks, which are the top plate portions of the upper and lower air springs, are connected to each other by the central support column, whereby the load on the supported body is reduced to 2. It is supported by two air springs.
JP 2002-31183 A JP 2005-241015 A

  By the way, when the top plate portions of the upper and lower air springs are connected to each other by the central support as described above, the support is on the supported body side, that is, on the spring, so the rigidity is not very high. Must not. This is because if there is a portion with low rigidity on the supported body side (on the spring), the vibration isolation performance will be affected by the resonance generated at this portion.

  However, if the rigidity of the support is increased as described above, it must be made considerably thicker, and the pressure receiving area of the upper air spring will be reduced accordingly, so the folding angle and the air spring will be multi-staged. Nevertheless, it was found that the pressure receiving area could not be increased as expected, and the maximum support load was not increased so much.

  The present invention has been made in view of such a point, and the object of the present invention is to devise a connection structure between upper and lower gas springs so that a portion having low rigidity cannot be formed on the spring. The purpose is to increase the load bearing performance by sufficiently increasing the total pressure receiving area of the gas springs.

  In order to achieve the above object, the present invention reverses the top and bottom of a multi-stage gas spring device as in the conventional examples (Patent Documents 1 and 2), so that the bottom plate portion (unsprung) of the upper and lower gas springs. On the other hand, the top plate portions (on the springs) on the supported body side are connected by a wall surrounding the outer periphery to form an integral box shape.

  That is, the invention of claim 1 is directed to a multistage gas spring vibration isolator provided with at least two upper and lower gas springs that support a supported body with respect to a foundation. As shown in Fig. 1, a support column (5) is provided so as to extend from the inner peripheral portion of the bottom plate portion (1) of the lower gas spring (4) toward the upper gas chamber. Is inserted through a through hole (11a) formed in the top plate portion (11) of the lower gas spring (4) and further extended upward, and the space between the outer periphery and the peripheral edge of the through hole (11a) is flexible. The member (13) is hermetically sealed. And while connecting the upper end of the column (5) to the inner peripheral side portion of the bottom plate portion (7) of the upper gas spring (3), the outer periphery of the top plate portion (2) of the upper gas spring (3) A peripheral wall (20) is provided so as to hang downward from the bottom, and the lower end portion of the peripheral wall (20) is connected to the outer periphery of the top plate portion (7) of the lower gas spring (4).

  Since the gas spring vibration isolator (A) having the above configuration includes at least two gas springs (3, 4) in the upper stage and the lower stage, the installation area does not become very large even if the total pressure receiving area thereof is increased. Moreover, the bottom plate portions (7, 11) (unsprung) of these gas springs (3,4) are connected to each other by a support column (5) at a position closer to the inner periphery, and this support column (5) is also unsprung. Therefore, the column (5) can be made thinner than that on the spring as in the conventional example, and the pressure receiving area of the gas spring (4) can be increased accordingly.

  On the other hand, the top plate portions (2,1) (on the spring) of the upper and lower gas springs (3,4) are connected by an outer peripheral wall (20), and they are integrally formed in a box shape. Therefore, it is easy to increase the rigidity as a whole. Therefore, while preventing a portion with low rigidity from being formed on the spring, the effect of expanding the pressure receiving area due to the multistage of the gas spring can be sufficiently obtained, and the load supporting performance can be enhanced as intended.

  Note that the unsprung support column (5) only needs to have a strength sufficient to withstand the maximum support load, even if resonance occurs in a relatively low frequency range due to insufficient rigidity. The vibration due to is absorbed by the gas springs (3, 4), and since the influence on the supported body side on the spring is small, the vibration isolation performance does not deteriorate.

  In the gas spring vibration isolator as described above, a horizontal gas spring may be provided to apply a horizontal force to the supported body. In this case, it is preferable to use the horizontal gas spring. A spring is disposed between the upper and lower gas springs so that a spring force acts between the support column and the peripheral wall. By doing so, the force generated by the horizontal gas spring acts near the load supporting point in the vibration isolator, and the moment is reduced, so that an unreasonable force does not act on the supported body side.

  More preferably, the gas springs in the horizontal direction are arranged to face each other with a support interposed therebetween, and the respective gas chambers are formed inside the peripheral wall (Claim 3). If the horizontal gas springs are arranged so as to face each other in this manner, it is advantageous in stably applying a horizontal force to the supported body. In addition, in order to form the gas chamber inside the peripheral wall, it is necessary to increase the thickness of the entire peripheral wall accordingly, which is preferable in securing the rigidity of the peripheral wall on the spring.

  Further, considering the supply and discharge of gas to and from the upper and lower gas springs, it is preferable that the volumes of the gas chambers are substantially the same (claim 4). In this way, even if the gas supply / discharge amount for these gas springs is controlled by a common valve, the pressure of each gas spring will change in substantially the same way, so the settling time is shortened and controllability is improved. To do.

  Further, at least a part of the passage for supplying and discharging gas to and from the gas spring is preferably formed inside the column. In this way, in both the vertical direction and the horizontal direction, the length of the gas supply / discharge passage to the two gas springs that make a pair can be made substantially the same, and the above action can be made more reliable, In addition, the length of the gas supply / discharge passage to each gas spring can be shortened, and the control response can be improved.

  Although FIG. 1 shows an example having two upper and lower gas springs as an example, an intermediate gas spring may be provided between the upper and lower gas springs. In this case, the support column is fixed in a penetrating state to a portion on the inner peripheral side of the bottom plate portion of the middle gas spring, and further extended upward through a through hole formed in the top plate portion of the middle gas spring. What is necessary is just to airtightly seal between the outer periphery and the periphery of a through-hole with a flexible member. Moreover, what is necessary is just to connect the inner periphery of a surrounding wall with the outer periphery of the top-plate part of the said middle stage gas spring.

  As described above, according to the multistage gas spring vibration isolator according to the present invention, the bottom plate portions (unsprung) of the upper and lower gas springs are connected by the support column, while the top plate portions (spring tops) are connected to each other. By connecting them with the outer peripheral wall and making them into an integral box shape, the struts that are unsprung can be made thinner than before, while preventing the part with low rigidity from being formed on the spring. Also, the pressure receiving area of the gas spring can be increased. Therefore, the effect of expanding the pressure receiving area due to the multistage of the gas spring can be sufficiently obtained, and the load supporting performance can be enhanced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that the following description of the preferred embodiment is merely illustrative in nature, and is not intended to limit the present invention, its application, or its use.

  2 and 3 show an air mount A which is an embodiment of a gas spring vibration isolator according to the present invention. This air mount A is used to install a precision device (supported body) such as a semiconductor related device (not shown) in a state of being almost insulated from floor vibration, and usually 3 to 5 air mounts A, A, ... supports the supported body.

  The air mount A according to this embodiment has a bottom plate 1 installed on a floor surface (foundation) F and precision equipment or the like, as shown in cross section in FIG. And an upper air spring 3 (gas spring) that supports the load of the supported body using the top plate 2 as a top plate portion. In addition, similarly, it is a two-stage upper and lower type provided with a lower air spring 4 having the bottom plate 1 as a bottom plate portion. In this example, the two air springs 3 and 4 have air chambers having substantially the same volume.

  Each of the bottom plate 1 and the top plate 2 is a rectangular thick plate member formed by forging an aluminum alloy material, and has high rigidity while being lighter than that made of steel. As shown only in FIG. 4, a cylindrical shaft member 5 is disposed so as to extend upward from a substantially central portion of the upper surface of the bottom plate 1, and a substantially rectangular parallelepiped center block 6 is disposed thereon. Further, the upper air spring 3 is disposed thereon.

  That is, a disc-shaped upper plate 7 having a larger diameter than that of the center block 6 is overlapped and fastened to the upper surface of the center block 6, and an annular shape made of a rubber material is interposed between the outer peripheral portion and the outer peripheral portion of the top plate 2. A diaphragm 8 is provided to connect the top plate 2 to the upper plate 7 so as to be movable up and down. The upper air spring 3 is configured with a volume-variable sealed space partitioned between the top plate 2 and the upper plate 7 by the diaphragm 8 as an air chamber, and the upper plate 7 is a bottom plate portion thereof.

  In the upper air spring 3, a convex portion 2 a having a circular cross section toward the air chamber is formed on the lower surface of the top plate 2, and this is a stopper that restricts the downward displacement of the top plate 2 with respect to the upper plate 7. It functions as a part. Further, in FIG. 4, reference numeral 9 indicates a fastening ring that fixes the outer peripheral portion of the diaphragm 8 between the outer peripheral portion of the lower surface of the top plate 2, and similarly, reference numeral 10 indicates the upper peripheral portion of the diaphragm 8. A tightening ring that is sandwiched and fixed between the upper peripheral portion of the upper surface of the plate 7 is shown.

  In FIG. 4, the center block 6 is illustrated as being divided into a central block member and upper and lower plate members. However, the present invention is not limited to this, and the center block 6 may be configured as a single member. On the contrary, the central block member can be further divided into a plurality of members. Similarly, the shaft member 5 or the like shown as a single member in the drawing can be divided into a plurality of members.

  Similar to the upper air spring 3 having the above-described configuration, the lower air spring 4 is formed by connecting a bottom plate 1 and a lower plate 11 located above the bottom plate 1 by an annular diaphragm 12. The lower plate 11 is a top plate portion of the lower air spring 4 and is made of an aluminum alloy plate member similar to the bottom plate 1 and the top plate 2. In this embodiment, these four corners are cut out to form a flat surface. It is formed in an octagonal shape visually.

  As shown only in FIG. 4, a through hole 11 a having a circular cross section is formed in a substantially central portion of the lower plate 11, and a shaft member 5 extending from the bottom plate 1 is inserted therethrough. A gap is formed between the outer peripheral surface of the shaft member 5 and the inner peripheral surface of the through hole 11a, and an annular diaphragm 13 (flexible member) made of a rubber material so as to hermetically seal the gap. ) Is arranged. Further, the lower half portion of the shaft member 5 has a smaller diameter than the upper half portion, and a fastening ring 14 for fixing the inner peripheral portion of the diaphragm 13 is extrapolated.

  In the lower air spring 4, a convex portion 1a having a circular cross section is formed on the upper surface of the bottom plate 1, while an annular convex portion 11b is formed on the lower surface of the lower plate 11 facing upward. By abutting, the displacement in the relative proximity direction of both is regulated. Further, the relative displacement of the bottom plate 1 and the lower plate 11 is restricted by the upper surface of the lower plate 11 coming into contact with the lower surface of the center block 6. Reference numerals 15 to 17 shown in the figure are fastening rings for fixing the inner and outer peripheral portions of the diaphragms 12 and 13 in the same manner as the fastening ring 14.

  Thus, in the air mount A of this embodiment, the shaft member 5 extending upward from the substantially central portion of the bottom plate 1 that is the bottom plate portion of the lower air spring 4 is formed in the through hole 11a of the lower plate 11 that is the top plate portion. With the center block 6 that passes through the upper air spring 3 (upper plate 7), a support column that supports the upper air spring 3 (upper plate 7) from below is formed. That is, the upper and lower two air springs 3 and 4 have their base sides, that is, the bottom plate portions (bottom plate 1 and upper plate 7), which are under the spring, are supported by a column made up of the shaft member 5 and the center block 6. It is connected.

  Thus, in the upper gas spring 3 that supports the bottom plate (upper plate 7) from below, the outer periphery extending downward through the frame 18 is provided on the outer periphery of the lower surface of the top plate 2 that is the top plate. A wall 20 is attached. The frame 18 has a generally “B” shape in a plan view, and surrounds the outer periphery of the upper plate 7 while being spaced apart from the lower end thereof, approaching the inner peripheral side from the lower end thereof, and approaching the upper side surface of the center block 6. These are flat plate portions extending to the same, and are integrally formed of an aluminum alloy material.

  The outer peripheral wall 20 includes four thick wall members 21 to 24 each formed in a lump shape by an aluminum alloy material, and these are arranged so as to surround the center block 6 corresponding to the front, rear, left and right of the air mount A. Thus, adjacent ones in the circumferential direction are joined together by joining their side edges. That is, the upper end of the outer peripheral wall 20 is fastened to the top plate 2 via the frame 18 as described above, while the lower end is fastened to the outer peripheral portion of the upper surface of the lower plate 11 and they are integrally formed in a box shape. Has been.

  That is, the outer peripheral wall 20 made of thick wall members 21 to 24 is provided on the supported body side of the two air springs 3 and 4 in the upper and lower stages, that is, the top plate portions (top plate 2 and lower plate 11) on the springs. Are connected in a box shape, so that their overall rigidity is sufficiently high.

  The left and right wall members 21 and 22 constituting the outer peripheral wall 20 are formed thicker than the front and rear wall members 23 and 24, and concave portions 21a and 22a having a circular cross section are opened on the inner surfaces thereof. Further, columnar convex portions 6a and 6b having a diameter smaller than those of the concave portions 21a and 22a are provided on the left and right side surfaces of the center block 6 facing the inner surfaces of the left and right wall members 21 and 22, respectively. Extends to the vicinity of the openings of the recesses 21a and 22a. The gap between them is sealed with rubber diaphragms 25 and 25 to form air chambers, whereby horizontal air springs 26 and 27 are formed. In addition, the code | symbols 28 and 29 of illustration are the fastening rings for fixing the outer peripheral part and inner peripheral part of the diaphragms 25 and 25, respectively.

  The horizontal air springs 26 and 27 are arranged opposite to the left and right with the center block 6 interposed therebetween (hereinafter referred to as the left and right horizontal air springs). By operating them in opposite phases, the center block 6 ( A horizontal force can be applied to the outer peripheral wall 20 (on the spring) in the same direction in the same direction from the unsprung). This is advantageous in stably applying a horizontal force to the supported body side, and is also advantageous in enhancing the response of vibration control by the force.

  The left and right horizontal air springs 26 and 27 are arranged between the upper air spring 3 and the lower air spring 4, and the horizontal force acting on the outer peripheral wall 20 from the center block 6 as described above is The air mount A acts near the load support point. This means that the moment acting around the load support point is reduced by the horizontal force, and the top plate 2 is inclined by such a moment and an unreasonable force is applied to the supported side. This is advantageous for prevention.

  Further, the left and right wall members 21 and 22 are formed with recesses 21a and 22a that serve as air chambers for the horizontal air springs 26 and 27, respectively, and the thickness of the left and right wall members 21 and 22 is increased accordingly. This can be said to be preferable in order to increase the rigidity of the left and right wall members 21 and 22 as a result.

  As described above, the center block 6 functions as a support for connecting the upper and lower air springs 3, 4 to each other, and supports the left and right horizontal air springs 26, 27. A supply / discharge control system for supplying and discharging air to / from 3, 4, 26, and 27 is provided. Specifically, as shown in FIGS. 3 and 4, servo valves 30 and 31 are arranged on the front surface of the center block 6, and one servo valve 30 is the same formed inside the center block 6. Air is supplied to and discharged from the left and right horizontal air springs 26 and 27 through a pair of long air passages 32 and 33.

  Although not shown, the air passage 34 to which the other servo valve 31 is connected opens at the rear surface of the center block 6, and the pipe connected thereto branches into two branches so that the path length is substantially the same. Thus, air is supplied to and discharged from the upper and lower air springs 3 and 4. Further, each of the servo valves 30 and 31 is supplied with compressed air from an air pressure source (not shown) through an air passage opening on the rear surface of the center block 6 and a pipe connected thereto. .

  Such operation control of the servo valves 30 and 31 is performed only by a well-known controller 35 having a microcomputer, RAM, ROM and the like as shown only in FIG. That is, although not shown, the air mount A is provided with sensors for detecting the relative position, acceleration, and the like of the top plate 2 with respect to the bottom plate 1, and based on signals input from these sensors. The controller 35 controls the operation of the servo valves 30, 31 to control the pressures of the air springs 3, 4,.

  Since the air mount A configured as described above has the two air springs 3 and 4 in the upper and lower stages, the installation area does not become so large even though the total pressure receiving area is large. . In particular, the pressure receiving area of the lower air spring 4 is defined by both the outer diameter of the air chamber roughly determined by the outer dimension of the bottom plate 1 and the inner diameter of the air chamber approximately determined by the outer dimension of the shaft member 5. However, in this embodiment, since the shaft member 5 is under the spring, the shaft member 5 can be made thinner than when it is on the spring, and the pressure receiving area can be increased accordingly.

  That is, the unsprung shaft member 5 may have a strength sufficient to withstand the maximum support load required for the air mount A, and by reducing the thickness, the rigidity becomes low, and resonance occurs in a relatively low frequency range. Even if it occurs, the vibration caused by this can be absorbed by the air springs 3 and 4, and since the influence on the supported body side on the spring is small, the vibration isolation performance does not deteriorate. .

  On the other hand, the top plate portions (top plate 2 and lower plate 11) of the upper and lower air springs 3 and 4 that are springs are connected to each other by an outer peripheral wall 20 including thick wall members 21 to 24, and have high rigidity. Since it is box-shaped, there is no portion with low rigidity like the shaft member 5 on the spring, and low-frequency resonance that causes a reduction in vibration isolation performance does not occur.

  In short, in the air mount A (multistage air spring vibration isolator) of this embodiment, the shaft member 5 that restricts the expansion of the pressure receiving area of the lower air spring 4 among the upper and lower air springs 3 and 4 is provided. By adopting the unsprung shape, the outer diameter can be made thinner than the conventional one, and the pressure receiving area can be increased correspondingly, so that the load supporting performance can be enhanced as compared with the conventional one.

  In addition, in the air mount A of this embodiment, the air chamber volumes of the upper and lower air springs 3 and 4 are substantially the same, and the path lengths of the pipes for supplying and discharging air to the air springs A and 4 are also substantially the same. Even if the supply / discharge amount of the compressed air to and from the air springs 3 and 4 is controlled by the common servo valve 31, the pressures of the air springs 3 and 4 change in substantially the same manner, and the settling time is short. High controllability. This is also true for the left and right horizontal air springs 26 and 27.

  Moreover, not only the upper and lower air springs 3 and 4 but also the left and right horizontal air springs 26 and 27 are aired at the shortest distance via the air passages 32, 33,... Formed in the center block 6. Therefore, the control response is high.

  The configuration of the present invention is not limited to the above-described embodiment, and includes other various configurations. That is, in the air mount A of the above embodiment, the left and right horizontal air springs 26 and 27 are arranged in the middle of the upper and lower air springs 3 and 4 so as to face each other. The horizontal air springs 26 and 27 can also be disposed below the lower air spring 4 (in the example shown, the same reference numerals are assigned to substantially the same members as in the above embodiment).

  However, in such a case, the load support point of the supported body by the air mount 4 becomes high, and a large moment around the load support point is generated by the force generated by the horizontal air springs 26 and 27. Therefore, the top plate 2 tends to be distorted and tends to be distorted on the side of the support such as a surface plate.

  Although not shown in the figure, the horizontal air springs 26 and 27 can be arranged above the upper air spring 3 in the opposite direction to FIG. Since the center of gravity increases, for example, when a precision device or the like is a supported body, shaking tends to increase with the operation thereof.

  Therefore, it can be said that it is preferable to arrange the horizontal air springs 26 and 27 between the upper and lower air springs 3 and 4 as in the above embodiment. Of course, it is possible not to provide the horizontal air springs 26 and 27 as schematically shown in FIG.

  In the air mount A of the above embodiment, the diaphragms 8, 12,... Are used to define the air chambers in the respective air springs 3, 4,. . Also, any of the air springs 3, 4,... Can be a gas spring filled with, for example, nitrogen gas.

  Further, in the above embodiment, an air spring (middle air spring) may be further provided between the upper and lower air springs 3 and 4 so that the upper and lower air springs have three or more stages. In this case, although illustration is omitted, the shaft member 5 is fixed in a state where the substantially central portion of the bottom plate portion of the middle air spring is penetrated, and the shaft member 5 is attached to the top plate portion of the middle air spring. The formed through hole is passed through and extended upward, and a space between the outer periphery and the periphery of the through hole is hermetically sealed by a flexible member such as a rubber diaphragm. Further, the outer peripheral portion of the top plate portion of the middle air spring may be fixed to the inner periphery of the peripheral wall 20 connecting the upper and lower air springs 3 and 4.

  As described above, the multistage gas spring vibration isolator according to the present invention can improve the load supporting performance by multistage without impairing the vibration isolation performance, and thus particularly supports semiconductor-related devices and the like. It is suitable when it is desired to suppress an increase in the installation area like a thing.

It is sectional drawing which shows the basic composition of the multistage type gas spring vibration isolator of this invention. It is a perspective view which shows the external appearance of the air mount (vibration isolator) of embodiment. It is a perspective view which removes the upper air spring from the air mount and shows it. It is a fragmentary sectional view showing the detailed structure of the air mount. FIG. 5 is a view corresponding to FIG. 4 according to another embodiment in which a horizontal air spring is disposed below a lower air spring.

Explanation of symbols

A Air mount (Multistage gas spring vibration isolator)
1 Bottom plate (bottom plate of the lower gas spring)
2 Top plate (top plate of upper gas spring)
3 Upper air spring (upper gas spring)
4 Lower air spring (lower gas spring)
5 Shaft member (support)
6 Center block (support)
7 Upper plate (bottom plate of upper gas spring)
11 Lower plate (top plate of lower gas spring)
11a Through hole 13 Diaphragm (flexible member)
20 Perimeter wall (peripheral wall)
21-24 Wall member 21a, 22a Recessed part (gas chamber of gas spring in horizontal direction)
26, 27 Horizontal air spring (horizontal gas spring)
32-34 Air passage (Gas supply / discharge passage)

Claims (6)

The gas spring in the vertical direction that supports the supported body with respect to the foundation is a multistage gas spring vibration isolator provided with at least two upper and lower stages,
A support column is provided so as to extend from the portion near the inner periphery of the bottom plate portion of the lower gas spring toward the upper gas chamber,
The support column extends upward through a through hole formed in the top plate portion of the lower gas spring, and a space between the outer periphery and the periphery of the through hole is hermetically sealed by a flexible member. With
While the upper end of the support column is connected to the inner peripheral portion of the bottom plate portion of the upper gas spring, a peripheral wall is provided so as to hang downward from the outer periphery of the top plate portion of the upper gas spring. The multistage gas spring vibration isolator is characterized in that the portion is connected to the outer periphery of the top plate portion of the lower gas spring. A horizontal gas spring is disposed between the bottom plate portion of the upper gas spring and the top plate portion of the lower gas spring so as to apply a spring force between the support column and the peripheral wall. The multistage gas spring vibration isolator according to claim 1.   3. The multistage gas spring vibration isolator according to claim 2, wherein the horizontal gas springs are arranged to face each other with a support interposed therebetween, and each gas chamber is formed inside the peripheral wall.   The multistage gas spring vibration isolator according to any one of claims 1 to 3, wherein the upper and lower gas springs have gas chambers having substantially the same volume.   The multistage gas spring vibration isolator according to any one of claims 1 to 4, wherein a passage for supplying and discharging gas to and from the gas spring is formed inside the support column. A middle gas spring is provided between the upper and lower gas springs,
The support column is fixed in a penetrating state to a portion on the inner peripheral side of the bottom plate portion of the middle gas spring, and extends upward through a through hole formed in the top plate portion of the middle gas spring. Between the outer periphery and the periphery of the through hole is hermetically sealed by a flexible member,
The multistage gas spring vibration isolator according to any one of claims 1 to 5, wherein an inner periphery of the peripheral wall is connected to an outer periphery of a top plate portion of the middle gas spring.

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